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	Version: linux-6.0.1 spark-3.0.0 hadoop-3.2.0-src hadoop-3.3.0-src spark-2.4.7 linux-4.15.13 hadoop-2.7.4-src Revert   Change

 // SPDX-License-Identifier: GPL-2.0-or-later
 /* SCTP kernel implementation
  * (C) Copyright IBM Corp. 2001, 2004
  * Copyright (c) 1999-2000 Cisco, Inc.
  * Copyright (c) 1999-2001 Motorola, Inc.
  * Copyright (c) 2001-2003 Intel Corp.
  * Copyright (c) 2001-2002 Nokia, Inc.
  * Copyright (c) 2001 La Monte H.P. Yarroll
  *
  * This file is part of the SCTP kernel implementation
  *
  * These functions interface with the sockets layer to implement the
  * SCTP Extensions for the Sockets API.
  *
  * Note that the descriptions from the specification are USER level
  * functions--this file is the functions which populate the struct proto
  * for SCTP which is the BOTTOM of the sockets interface.
  *
  * Please send any bug reports or fixes you make to the
  * email address(es):
  *    lksctp developers <linux-sctp@vger.kernel.org>
  *
  * Written or modified by:
  *    La Monte H.P. Yarroll <piggy@acm.org>
  *    Narasimha Budihal     <narsi@refcode.org>
  *    Karl Knutson          <karl@athena.chicago.il.us>
  *    Jon Grimm             <jgrimm@us.ibm.com>
  *    Xingang Guo           <xingang.guo@intel.com>
  *    Daisy Chang           <daisyc@us.ibm.com>
  *    Sridhar Samudrala     <samudrala@us.ibm.com>
  *    Inaky Perez-Gonzalez  <inaky.gonzalez@intel.com>
  *    Ardelle Fan       <ardelle.fan@intel.com>
  *    Ryan Layer        <rmlayer@us.ibm.com>
  *    Anup Pemmaiah         <pemmaiah@cc.usu.edu>
  *    Kevin Gao             <kevin.gao@intel.com>
  */
 
 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
 
 #include <crypto/hash.h>
 #include <linux/types.h>
 #include <linux/kernel.h>
 #include <linux/wait.h>
 #include <linux/time.h>
 #include <linux/sched/signal.h>
 #include <linux/ip.h>
 #include <linux/capability.h>
 #include <linux/fcntl.h>
 #include <linux/poll.h>
 #include <linux/init.h>
 #include <linux/slab.h>
 #include <linux/file.h>
 #include <linux/compat.h>
 #include <linux/rhashtable.h>
 
 #include <net/ip.h>
 #include <net/icmp.h>
 #include <net/route.h>
 #include <net/ipv6.h>
 #include <net/inet_common.h>
 #include <net/busy_poll.h>
 
 #include <linux/socket.h> /* for sa_family_t */
 #include <linux/export.h>
 #include <net/sock.h>
 #include <net/sctp/sctp.h>
 #include <net/sctp/sm.h>
 #include <net/sctp/stream_sched.h>
 
 /* Forward declarations for internal helper functions. */
 static bool sctp_writeable(struct sock *sk);
 static void sctp_wfree(struct sk_buff *skb);
 static int sctp_wait_for_sndbuf(struct sctp_association *asoc, long *timeo_p,
                 size_t msg_len);
 static int sctp_wait_for_packet(struct sock *sk, int *err, long *timeo_p);
 static int sctp_wait_for_connect(struct sctp_association *, long *timeo_p);
 static int sctp_wait_for_accept(struct sock *sk, long timeo);
 static void sctp_wait_for_close(struct sock *sk, long timeo);
 static void sctp_destruct_sock(struct sock *sk);
 static struct sctp_af *sctp_sockaddr_af(struct sctp_sock *opt,
                     union sctp_addr *addr, int len);
 static int sctp_bindx_add(struct sock *, struct sockaddr *, int);
 static int sctp_bindx_rem(struct sock *, struct sockaddr *, int);
 static int sctp_send_asconf_add_ip(struct sock *, struct sockaddr *, int);
 static int sctp_send_asconf_del_ip(struct sock *, struct sockaddr *, int);
 static int sctp_send_asconf(struct sctp_association *asoc,
                 struct sctp_chunk *chunk);
 static int sctp_do_bind(struct sock *, union sctp_addr *, int);
 static int sctp_autobind(struct sock *sk);
 static int sctp_sock_migrate(struct sock *oldsk, struct sock *newsk,
                  struct sctp_association *assoc,
                  enum sctp_socket_type type);
 
 static unsigned long sctp_memory_pressure;
 static atomic_long_t sctp_memory_allocated;
 static DEFINE_PER_CPU(int, sctp_memory_per_cpu_fw_alloc);
 struct percpu_counter sctp_sockets_allocated;
 
 static void sctp_enter_memory_pressure(struct sock *sk)
 {
     sctp_memory_pressure = 1;
 }
 
 
 /* Get the sndbuf space available at the time on the association.  */
 static inline int sctp_wspace(struct sctp_association *asoc)
 {
     struct sock *sk = asoc->base.sk;
 
     return asoc->ep->sndbuf_policy ? sk->sk_sndbuf - asoc->sndbuf_used
                        : sk_stream_wspace(sk);
 }
 
 /* Increment the used sndbuf space count of the corresponding association by
  * the size of the outgoing data chunk.
  * Also, set the skb destructor for sndbuf accounting later.
  *
  * Since it is always 1-1 between chunk and skb, and also a new skb is always
  * allocated for chunk bundling in sctp_packet_transmit(), we can use the
  * destructor in the data chunk skb for the purpose of the sndbuf space
  * tracking.
  */
 static inline void sctp_set_owner_w(struct sctp_chunk *chunk)
 {
     struct sctp_association *asoc = chunk->asoc;
     struct sock *sk = asoc->base.sk;
 
     /* The sndbuf space is tracked per association.  */
     sctp_association_hold(asoc);
 
     if (chunk->shkey)
         sctp_auth_shkey_hold(chunk->shkey);
 
     skb_set_owner_w(chunk->skb, sk);
 
     chunk->skb->destructor = sctp_wfree;
     /* Save the chunk pointer in skb for sctp_wfree to use later.  */
     skb_shinfo(chunk->skb)->destructor_arg = chunk;
 
     refcount_add(sizeof(struct sctp_chunk), &sk->sk_wmem_alloc);
     asoc->sndbuf_used += chunk->skb->truesize + sizeof(struct sctp_chunk);
     sk->sk_wmem_queued += chunk->skb->truesize + sizeof(struct sctp_chunk);
     sk_mem_charge(sk, chunk->skb->truesize);
 }
 
 static void sctp_clear_owner_w(struct sctp_chunk *chunk)
 {
     skb_orphan(chunk->skb);
 }
 
 #define traverse_and_process()  \
 do {                \
     msg = chunk->msg;   \
     if (msg == prev_msg)    \
         continue;   \
     list_for_each_entry(c, &msg->chunks, frag_list) {   \
         if ((clear && asoc->base.sk == c->skb->sk) ||   \
             (!clear && asoc->base.sk != c->skb->sk))    \
             cb(c);  \
     }           \
     prev_msg = msg;     \
 } while (0)
 
 static void sctp_for_each_tx_datachunk(struct sctp_association *asoc,
                        bool clear,
                        void (*cb)(struct sctp_chunk *))
 
 {
     struct sctp_datamsg *msg, *prev_msg = NULL;
     struct sctp_outq *q = &asoc->outqueue;
     struct sctp_chunk *chunk, *c;
     struct sctp_transport *t;
 
     list_for_each_entry(t, &asoc->peer.transport_addr_list, transports)
         list_for_each_entry(chunk, &t->transmitted, transmitted_list)
             traverse_and_process();
 
     list_for_each_entry(chunk, &q->retransmit, transmitted_list)
         traverse_and_process();
 
     list_for_each_entry(chunk, &q->sacked, transmitted_list)
         traverse_and_process();
 
     list_for_each_entry(chunk, &q->abandoned, transmitted_list)
         traverse_and_process();
 
     list_for_each_entry(chunk, &q->out_chunk_list, list)
         traverse_and_process();
 }
 
 static void sctp_for_each_rx_skb(struct sctp_association *asoc, struct sock *sk,
                  void (*cb)(struct sk_buff *, struct sock *))
 
 {
     struct sk_buff *skb, *tmp;
 
     sctp_skb_for_each(skb, &asoc->ulpq.lobby, tmp)
         cb(skb, sk);
 
     sctp_skb_for_each(skb, &asoc->ulpq.reasm, tmp)
         cb(skb, sk);
 
     sctp_skb_for_each(skb, &asoc->ulpq.reasm_uo, tmp)
         cb(skb, sk);
 }
 
 /* Verify that this is a valid address. */
 static inline int sctp_verify_addr(struct sock *sk, union sctp_addr *addr,
                    int len)
 {
     struct sctp_af *af;
 
     /* Verify basic sockaddr. */
     af = sctp_sockaddr_af(sctp_sk(sk), addr, len);
     if (!af)
         return -EINVAL;
 
     /* Is this a valid SCTP address?  */
     if (!af->addr_valid(addr, sctp_sk(sk), NULL))
         return -EINVAL;
 
     if (!sctp_sk(sk)->pf->send_verify(sctp_sk(sk), (addr)))
         return -EINVAL;
 
     return 0;
 }
 
 /* Look up the association by its id.  If this is not a UDP-style
  * socket, the ID field is always ignored.
  */
 struct sctp_association *sctp_id2assoc(struct sock *sk, sctp_assoc_t id)
 {
     struct sctp_association *asoc = NULL;
 
     /* If this is not a UDP-style socket, assoc id should be ignored. */
     if (!sctp_style(sk, UDP)) {
         /* Return NULL if the socket state is not ESTABLISHED. It
          * could be a TCP-style listening socket or a socket which
          * hasn't yet called connect() to establish an association.
          */
         if (!sctp_sstate(sk, ESTABLISHED) && !sctp_sstate(sk, CLOSING))
             return NULL;
 
         /* Get the first and the only association from the list. */
         if (!list_empty(&sctp_sk(sk)->ep->asocs))
             asoc = list_entry(sctp_sk(sk)->ep->asocs.next,
                       struct sctp_association, asocs);
         return asoc;
     }
 
     /* Otherwise this is a UDP-style socket. */
     if (id <= SCTP_ALL_ASSOC)
         return NULL;
 
     spin_lock_bh(&sctp_assocs_id_lock);
     asoc = (struct sctp_association *)idr_find(&sctp_assocs_id, (int)id);
     if (asoc && (asoc->base.sk != sk || asoc->base.dead))
         asoc = NULL;
     spin_unlock_bh(&sctp_assocs_id_lock);
 
     return asoc;
 }
 
 /* Look up the transport from an address and an assoc id. If both address and
  * id are specified, the associations matching the address and the id should be
  * the same.
  */
 static struct sctp_transport *sctp_addr_id2transport(struct sock *sk,
                           struct sockaddr_storage *addr,
                           sctp_assoc_t id)
 {
     struct sctp_association *addr_asoc = NULL, *id_asoc = NULL;
     struct sctp_af *af = sctp_get_af_specific(addr->ss_family);
     union sctp_addr *laddr = (union sctp_addr *)addr;
     struct sctp_transport *transport;
 
     if (!af || sctp_verify_addr(sk, laddr, af->sockaddr_len))
         return NULL;
 
     addr_asoc = sctp_endpoint_lookup_assoc(sctp_sk(sk)->ep,
                            laddr,
                            &transport);
 
     if (!addr_asoc)
         return NULL;
 
     id_asoc = sctp_id2assoc(sk, id);
     if (id_asoc && (id_asoc != addr_asoc))
         return NULL;
 
     sctp_get_pf_specific(sk->sk_family)->addr_to_user(sctp_sk(sk),
                         (union sctp_addr *)addr);
 
     return transport;
 }
 
 /* API 3.1.2 bind() - UDP Style Syntax
  * The syntax of bind() is,
  *
  *   ret = bind(int sd, struct sockaddr *addr, int addrlen);
  *
  *   sd      - the socket descriptor returned by socket().
  *   addr    - the address structure (struct sockaddr_in or struct
  *             sockaddr_in6 [RFC 2553]),
  *   addr_len - the size of the address structure.
  */
 static int sctp_bind(struct sock *sk, struct sockaddr *addr, int addr_len)
 {
     int retval = 0;
 
     lock_sock(sk);
 
     pr_debug("%s: sk:%p, addr:%p, addr_len:%d\n", __func__, sk,
          addr, addr_len);
 
     /* Disallow binding twice. */
     if (!sctp_sk(sk)->ep->base.bind_addr.port)
         retval = sctp_do_bind(sk, (union sctp_addr *)addr,
                       addr_len);
     else
         retval = -EINVAL;
 
     release_sock(sk);
 
     return retval;
 }
 
 static int sctp_get_port_local(struct sock *, union sctp_addr *);
 
 /* Verify this is a valid sockaddr. */
 static struct sctp_af *sctp_sockaddr_af(struct sctp_sock *opt,
                     union sctp_addr *addr, int len)
 {
     struct sctp_af *af;
 
     /* Check minimum size.  */
     if (len < sizeof (struct sockaddr))
         return NULL;
 
     if (!opt->pf->af_supported(addr->sa.sa_family, opt))
         return NULL;
 
     if (addr->sa.sa_family == AF_INET6) {
         if (len < SIN6_LEN_RFC2133)
             return NULL;
         /* V4 mapped address are really of AF_INET family */
         if (ipv6_addr_v4mapped(&addr->v6.sin6_addr) &&
             !opt->pf->af_supported(AF_INET, opt))
             return NULL;
     }
 
     /* If we get this far, af is valid. */
     af = sctp_get_af_specific(addr->sa.sa_family);
 
     if (len < af->sockaddr_len)
         return NULL;
 
     return af;
 }
 
 static void sctp_auto_asconf_init(struct sctp_sock *sp)
 {
     struct net *net = sock_net(&sp->inet.sk);
 
     if (net->sctp.default_auto_asconf) {
         spin_lock(&net->sctp.addr_wq_lock);
         list_add_tail(&sp->auto_asconf_list, &net->sctp.auto_asconf_splist);
         spin_unlock(&net->sctp.addr_wq_lock);
         sp->do_auto_asconf = 1;
     }
 }
 
 /* Bind a local address either to an endpoint or to an association.  */
 static int sctp_do_bind(struct sock *sk, union sctp_addr *addr, int len)
 {
     struct net *net = sock_net(sk);
     struct sctp_sock *sp = sctp_sk(sk);
     struct sctp_endpoint *ep = sp->ep;
     struct sctp_bind_addr *bp = &ep->base.bind_addr;
     struct sctp_af *af;
     unsigned short snum;
     int ret = 0;
 
     /* Common sockaddr verification. */
     af = sctp_sockaddr_af(sp, addr, len);
     if (!af) {
         pr_debug("%s: sk:%p, newaddr:%p, len:%d EINVAL\n",
              __func__, sk, addr, len);
         return -EINVAL;
     }
 
     snum = ntohs(addr->v4.sin_port);
 
     pr_debug("%s: sk:%p, new addr:%pISc, port:%d, new port:%d, len:%d\n",
          __func__, sk, &addr->sa, bp->port, snum, len);
 
     /* PF specific bind() address verification. */
     if (!sp->pf->bind_verify(sp, addr))
         return -EADDRNOTAVAIL;
 
     /* We must either be unbound, or bind to the same port.
      * It's OK to allow 0 ports if we are already bound.
      * We'll just inhert an already bound port in this case
      */
     if (bp->port) {
         if (!snum)
             snum = bp->port;
         else if (snum != bp->port) {
             pr_debug("%s: new port %d doesn't match existing port "
                  "%d\n", __func__, snum, bp->port);
             return -EINVAL;
         }
     }
 
     if (snum && inet_port_requires_bind_service(net, snum) &&
         !ns_capable(net->user_ns, CAP_NET_BIND_SERVICE))
         return -EACCES;
 
     /* See if the address matches any of the addresses we may have
      * already bound before checking against other endpoints.
      */
     if (sctp_bind_addr_match(bp, addr, sp))
         return -EINVAL;
 
     /* Make sure we are allowed to bind here.
      * The function sctp_get_port_local() does duplicate address
      * detection.
      */
     addr->v4.sin_port = htons(snum);
     if (sctp_get_port_local(sk, addr))
         return -EADDRINUSE;
 
     /* Refresh ephemeral port.  */
     if (!bp->port) {
         bp->port = inet_sk(sk)->inet_num;
         sctp_auto_asconf_init(sp);
     }
 
     /* Add the address to the bind address list.
      * Use GFP_ATOMIC since BHs will be disabled.
      */
     ret = sctp_add_bind_addr(bp, addr, af->sockaddr_len,
                  SCTP_ADDR_SRC, GFP_ATOMIC);
 
     if (ret) {
         sctp_put_port(sk);
         return ret;
     }
     /* Copy back into socket for getsockname() use. */
     inet_sk(sk)->inet_sport = htons(inet_sk(sk)->inet_num);
     sp->pf->to_sk_saddr(addr, sk);
 
     return ret;
 }
 
  /* ADDIP Section 4.1.1 Congestion Control of ASCONF Chunks
  *
  * R1) One and only one ASCONF Chunk MAY be in transit and unacknowledged
  * at any one time.  If a sender, after sending an ASCONF chunk, decides
  * it needs to transfer another ASCONF Chunk, it MUST wait until the
  * ASCONF-ACK Chunk returns from the previous ASCONF Chunk before sending a
  * subsequent ASCONF. Note this restriction binds each side, so at any
  * time two ASCONF may be in-transit on any given association (one sent
  * from each endpoint).
  */
 static int sctp_send_asconf(struct sctp_association *asoc,
                 struct sctp_chunk *chunk)
 {
     int retval = 0;
 
     /* If there is an outstanding ASCONF chunk, queue it for later
      * transmission.
      */
     if (asoc->addip_last_asconf) {
         list_add_tail(&chunk->list, &asoc->addip_chunk_list);
         goto out;
     }
 
     /* Hold the chunk until an ASCONF_ACK is received. */
     sctp_chunk_hold(chunk);
     retval = sctp_primitive_ASCONF(asoc->base.net, asoc, chunk);
     if (retval)
         sctp_chunk_free(chunk);
     else
         asoc->addip_last_asconf = chunk;
 
 out:
     return retval;
 }
 
 /* Add a list of addresses as bind addresses to local endpoint or
  * association.
  *
  * Basically run through each address specified in the addrs/addrcnt
  * array/length pair, determine if it is IPv6 or IPv4 and call
  * sctp_do_bind() on it.
  *
  * If any of them fails, then the operation will be reversed and the
  * ones that were added will be removed.
  *
  * Only sctp_setsockopt_bindx() is supposed to call this function.
  */
 static int sctp_bindx_add(struct sock *sk, struct sockaddr *addrs, int addrcnt)
 {
     int cnt;
     int retval = 0;
     void *addr_buf;
     struct sockaddr *sa_addr;
     struct sctp_af *af;
 
     pr_debug("%s: sk:%p, addrs:%p, addrcnt:%d\n", __func__, sk,
          addrs, addrcnt);
 
     addr_buf = addrs;
     for (cnt = 0; cnt < addrcnt; cnt++) {
         /* The list may contain either IPv4 or IPv6 address;
          * determine the address length for walking thru the list.
          */
         sa_addr = addr_buf;
         af = sctp_get_af_specific(sa_addr->sa_family);
         if (!af) {
             retval = -EINVAL;
             goto err_bindx_add;
         }
 
         retval = sctp_do_bind(sk, (union sctp_addr *)sa_addr,
                       af->sockaddr_len);
 
         addr_buf += af->sockaddr_len;
 
 err_bindx_add:
         if (retval < 0) {
             /* Failed. Cleanup the ones that have been added */
             if (cnt > 0)
                 sctp_bindx_rem(sk, addrs, cnt);
             return retval;
         }
     }
 
     return retval;
 }
 
 /* Send an ASCONF chunk with Add IP address parameters to all the peers of the
  * associations that are part of the endpoint indicating that a list of local
  * addresses are added to the endpoint.
  *
  * If any of the addresses is already in the bind address list of the
  * association, we do not send the chunk for that association.  But it will not
  * affect other associations.
  *
  * Only sctp_setsockopt_bindx() is supposed to call this function.
  */
 static int sctp_send_asconf_add_ip(struct sock      *sk,
                    struct sockaddr  *addrs,
                    int          addrcnt)
 {
     struct sctp_sock        *sp;
     struct sctp_endpoint        *ep;
     struct sctp_association     *asoc;
     struct sctp_bind_addr       *bp;
     struct sctp_chunk       *chunk;
     struct sctp_sockaddr_entry  *laddr;
     union sctp_addr         *addr;
     union sctp_addr         saveaddr;
     void                *addr_buf;
     struct sctp_af          *af;
     struct list_head        *p;
     int                 i;
     int                 retval = 0;
 
     sp = sctp_sk(sk);
     ep = sp->ep;
 
     if (!ep->asconf_enable)
         return retval;
 
     pr_debug("%s: sk:%p, addrs:%p, addrcnt:%d\n",
          __func__, sk, addrs, addrcnt);
 
     list_for_each_entry(asoc, &ep->asocs, asocs) {
         if (!asoc->peer.asconf_capable)
             continue;
 
         if (asoc->peer.addip_disabled_mask & SCTP_PARAM_ADD_IP)
             continue;
 
         if (!sctp_state(asoc, ESTABLISHED))
             continue;
 
         /* Check if any address in the packed array of addresses is
          * in the bind address list of the association. If so,
          * do not send the asconf chunk to its peer, but continue with
          * other associations.
          */
         addr_buf = addrs;
         for (i = 0; i < addrcnt; i++) {
             addr = addr_buf;
             af = sctp_get_af_specific(addr->v4.sin_family);
             if (!af) {
                 retval = -EINVAL;
                 goto out;
             }
 
             if (sctp_assoc_lookup_laddr(asoc, addr))
                 break;
 
             addr_buf += af->sockaddr_len;
         }
         if (i < addrcnt)
             continue;
 
         /* Use the first valid address in bind addr list of
          * association as Address Parameter of ASCONF CHUNK.
          */
         bp = &asoc->base.bind_addr;
         p = bp->address_list.next;
         laddr = list_entry(p, struct sctp_sockaddr_entry, list);
         chunk = sctp_make_asconf_update_ip(asoc, &laddr->a, addrs,
                            addrcnt, SCTP_PARAM_ADD_IP);
         if (!chunk) {
             retval = -ENOMEM;
             goto out;
         }
 
         /* Add the new addresses to the bind address list with
          * use_as_src set to 0.
          */
         addr_buf = addrs;
         for (i = 0; i < addrcnt; i++) {
             addr = addr_buf;
             af = sctp_get_af_specific(addr->v4.sin_family);
             memcpy(&saveaddr, addr, af->sockaddr_len);
             retval = sctp_add_bind_addr(bp, &saveaddr,
                             sizeof(saveaddr),
                             SCTP_ADDR_NEW, GFP_ATOMIC);
             addr_buf += af->sockaddr_len;
         }
         if (asoc->src_out_of_asoc_ok) {
             struct sctp_transport *trans;
 
             list_for_each_entry(trans,
                 &asoc->peer.transport_addr_list, transports) {
                 trans->cwnd = min(4*asoc->pathmtu, max_t(__u32,
                     2*asoc->pathmtu, 4380));
                 trans->ssthresh = asoc->peer.i.a_rwnd;
                 trans->rto = asoc->rto_initial;
                 sctp_max_rto(asoc, trans);
                 trans->rtt = trans->srtt = trans->rttvar = 0;
                 /* Clear the source and route cache */
                 sctp_transport_route(trans, NULL,
                              sctp_sk(asoc->base.sk));
             }
         }
         retval = sctp_send_asconf(asoc, chunk);
     }
 
 out:
     return retval;
 }
 
 /* Remove a list of addresses from bind addresses list.  Do not remove the
  * last address.
  *
  * Basically run through each address specified in the addrs/addrcnt
  * array/length pair, determine if it is IPv6 or IPv4 and call
  * sctp_del_bind() on it.
  *
  * If any of them fails, then the operation will be reversed and the
  * ones that were removed will be added back.
  *
  * At least one address has to be left; if only one address is
  * available, the operation will return -EBUSY.
  *
  * Only sctp_setsockopt_bindx() is supposed to call this function.
  */
 static int sctp_bindx_rem(struct sock *sk, struct sockaddr *addrs, int addrcnt)
 {
     struct sctp_sock *sp = sctp_sk(sk);
     struct sctp_endpoint *ep = sp->ep;
     int cnt;
     struct sctp_bind_addr *bp = &ep->base.bind_addr;
     int retval = 0;
     void *addr_buf;
     union sctp_addr *sa_addr;
     struct sctp_af *af;
 
     pr_debug("%s: sk:%p, addrs:%p, addrcnt:%d\n",
          __func__, sk, addrs, addrcnt);
 
     addr_buf = addrs;
     for (cnt = 0; cnt < addrcnt; cnt++) {
         /* If the bind address list is empty or if there is only one
          * bind address, there is nothing more to be removed (we need
          * at least one address here).
          */
         if (list_empty(&bp->address_list) ||
             (sctp_list_single_entry(&bp->address_list))) {
             retval = -EBUSY;
             goto err_bindx_rem;
         }
 
         sa_addr = addr_buf;
         af = sctp_get_af_specific(sa_addr->sa.sa_family);
         if (!af) {
             retval = -EINVAL;
             goto err_bindx_rem;
         }
 
         if (!af->addr_valid(sa_addr, sp, NULL)) {
             retval = -EADDRNOTAVAIL;
             goto err_bindx_rem;
         }
 
         if (sa_addr->v4.sin_port &&
             sa_addr->v4.sin_port != htons(bp->port)) {
             retval = -EINVAL;
             goto err_bindx_rem;
         }
 
         if (!sa_addr->v4.sin_port)
             sa_addr->v4.sin_port = htons(bp->port);
 
         /* FIXME - There is probably a need to check if sk->sk_saddr and
          * sk->sk_rcv_addr are currently set to one of the addresses to
          * be removed. This is something which needs to be looked into
          * when we are fixing the outstanding issues with multi-homing
          * socket routing and failover schemes. Refer to comments in
          * sctp_do_bind(). -daisy
          */
         retval = sctp_del_bind_addr(bp, sa_addr);
 
         addr_buf += af->sockaddr_len;
 err_bindx_rem:
         if (retval < 0) {
             /* Failed. Add the ones that has been removed back */
             if (cnt > 0)
                 sctp_bindx_add(sk, addrs, cnt);
             return retval;
         }
     }
 
     return retval;
 }
 
 /* Send an ASCONF chunk with Delete IP address parameters to all the peers of
  * the associations that are part of the endpoint indicating that a list of
  * local addresses are removed from the endpoint.
  *
  * If any of the addresses is already in the bind address list of the
  * association, we do not send the chunk for that association.  But it will not
  * affect other associations.
  *
  * Only sctp_setsockopt_bindx() is supposed to call this function.
  */
 static int sctp_send_asconf_del_ip(struct sock      *sk,
                    struct sockaddr  *addrs,
                    int          addrcnt)
 {
     struct sctp_sock    *sp;
     struct sctp_endpoint    *ep;
     struct sctp_association *asoc;
     struct sctp_transport   *transport;
     struct sctp_bind_addr   *bp;
     struct sctp_chunk   *chunk;
     union sctp_addr     *laddr;
     void            *addr_buf;
     struct sctp_af      *af;
     struct sctp_sockaddr_entry *saddr;
     int             i;
     int             retval = 0;
     int         stored = 0;
 
     chunk = NULL;
     sp = sctp_sk(sk);
     ep = sp->ep;
 
     if (!ep->asconf_enable)
         return retval;
 
     pr_debug("%s: sk:%p, addrs:%p, addrcnt:%d\n",
          __func__, sk, addrs, addrcnt);
 
     list_for_each_entry(asoc, &ep->asocs, asocs) {
 
         if (!asoc->peer.asconf_capable)
             continue;
 
         if (asoc->peer.addip_disabled_mask & SCTP_PARAM_DEL_IP)
             continue;
 
         if (!sctp_state(asoc, ESTABLISHED))
             continue;
 
         /* Check if any address in the packed array of addresses is
          * not present in the bind address list of the association.
          * If so, do not send the asconf chunk to its peer, but
          * continue with other associations.
          */
         addr_buf = addrs;
         for (i = 0; i < addrcnt; i++) {
             laddr = addr_buf;
             af = sctp_get_af_specific(laddr->v4.sin_family);
             if (!af) {
                 retval = -EINVAL;
                 goto out;
             }
 
             if (!sctp_assoc_lookup_laddr(asoc, laddr))
                 break;
 
             addr_buf += af->sockaddr_len;
         }
         if (i < addrcnt)
             continue;
 
         /* Find one address in the association's bind address list
          * that is not in the packed array of addresses. This is to
          * make sure that we do not delete all the addresses in the
          * association.
          */
         bp = &asoc->base.bind_addr;
         laddr = sctp_find_unmatch_addr(bp, (union sctp_addr *)addrs,
                            addrcnt, sp);
         if ((laddr == NULL) && (addrcnt == 1)) {
             if (asoc->asconf_addr_del_pending)
                 continue;
             asoc->asconf_addr_del_pending =
                 kzalloc(sizeof(union sctp_addr), GFP_ATOMIC);
             if (asoc->asconf_addr_del_pending == NULL) {
                 retval = -ENOMEM;
                 goto out;
             }
             asoc->asconf_addr_del_pending->sa.sa_family =
                     addrs->sa_family;
             asoc->asconf_addr_del_pending->v4.sin_port =
                     htons(bp->port);
             if (addrs->sa_family == AF_INET) {
                 struct sockaddr_in *sin;
 
                 sin = (struct sockaddr_in *)addrs;
                 asoc->asconf_addr_del_pending->v4.sin_addr.s_addr = sin->sin_addr.s_addr;
             } else if (addrs->sa_family == AF_INET6) {
                 struct sockaddr_in6 *sin6;
 
                 sin6 = (struct sockaddr_in6 *)addrs;
                 asoc->asconf_addr_del_pending->v6.sin6_addr = sin6->sin6_addr;
             }
 
             pr_debug("%s: keep the last address asoc:%p %pISc at %p\n",
                  __func__, asoc, &asoc->asconf_addr_del_pending->sa,
                  asoc->asconf_addr_del_pending);
 
             asoc->src_out_of_asoc_ok = 1;
             stored = 1;
             goto skip_mkasconf;
         }
 
         if (laddr == NULL)
             return -EINVAL;
 
         /* We do not need RCU protection throughout this loop
          * because this is done under a socket lock from the
          * setsockopt call.
          */
         chunk = sctp_make_asconf_update_ip(asoc, laddr, addrs, addrcnt,
                            SCTP_PARAM_DEL_IP);
         if (!chunk) {
             retval = -ENOMEM;
             goto out;
         }
 
 skip_mkasconf:
         /* Reset use_as_src flag for the addresses in the bind address
          * list that are to be deleted.
          */
         addr_buf = addrs;
         for (i = 0; i < addrcnt; i++) {
             laddr = addr_buf;
             af = sctp_get_af_specific(laddr->v4.sin_family);
             list_for_each_entry(saddr, &bp->address_list, list) {
                 if (sctp_cmp_addr_exact(&saddr->a, laddr))
                     saddr->state = SCTP_ADDR_DEL;
             }
             addr_buf += af->sockaddr_len;
         }
 
         /* Update the route and saddr entries for all the transports
          * as some of the addresses in the bind address list are
          * about to be deleted and cannot be used as source addresses.
          */
         list_for_each_entry(transport, &asoc->peer.transport_addr_list,
                     transports) {
             sctp_transport_route(transport, NULL,
                          sctp_sk(asoc->base.sk));
         }
 
         if (stored)
             /* We don't need to transmit ASCONF */
             continue;
         retval = sctp_send_asconf(asoc, chunk);
     }
 out:
     return retval;
 }
 
 /* set addr events to assocs in the endpoint.  ep and addr_wq must be locked */
 int sctp_asconf_mgmt(struct sctp_sock *sp, struct sctp_sockaddr_entry *addrw)
 {
     struct sock *sk = sctp_opt2sk(sp);
     union sctp_addr *addr;
     struct sctp_af *af;
 
     /* It is safe to write port space in caller. */
     addr = &addrw->a;
     addr->v4.sin_port = htons(sp->ep->base.bind_addr.port);
     af = sctp_get_af_specific(addr->sa.sa_family);
     if (!af)
         return -EINVAL;
     if (sctp_verify_addr(sk, addr, af->sockaddr_len))
         return -EINVAL;
 
     if (addrw->state == SCTP_ADDR_NEW)
         return sctp_send_asconf_add_ip(sk, (struct sockaddr *)addr, 1);
     else
         return sctp_send_asconf_del_ip(sk, (struct sockaddr *)addr, 1);
 }
 
 /* Helper for tunneling sctp_bindx() requests through sctp_setsockopt()
  *
  * API 8.1
  * int sctp_bindx(int sd, struct sockaddr *addrs, int addrcnt,
  *                int flags);
  *
  * If sd is an IPv4 socket, the addresses passed must be IPv4 addresses.
  * If the sd is an IPv6 socket, the addresses passed can either be IPv4
  * or IPv6 addresses.
  *
  * A single address may be specified as INADDR_ANY or IN6ADDR_ANY, see
  * Section 3.1.2 for this usage.
  *
  * addrs is a pointer to an array of one or more socket addresses. Each
  * address is contained in its appropriate structure (i.e. struct
  * sockaddr_in or struct sockaddr_in6) the family of the address type
  * must be used to distinguish the address length (note that this
  * representation is termed a "packed array" of addresses). The caller
  * specifies the number of addresses in the array with addrcnt.
  *
  * On success, sctp_bindx() returns 0. On failure, sctp_bindx() returns
  * -1, and sets errno to the appropriate error code.
  *
  * For SCTP, the port given in each socket address must be the same, or
  * sctp_bindx() will fail, setting errno to EINVAL.
  *
  * The flags parameter is formed from the bitwise OR of zero or more of
  * the following currently defined flags:
  *
  * SCTP_BINDX_ADD_ADDR
  *
  * SCTP_BINDX_REM_ADDR
  *
  * SCTP_BINDX_ADD_ADDR directs SCTP to add the given addresses to the
  * association, and SCTP_BINDX_REM_ADDR directs SCTP to remove the given
  * addresses from the association. The two flags are mutually exclusive;
  * if both are given, sctp_bindx() will fail with EINVAL. A caller may
  * not remove all addresses from an association; sctp_bindx() will
  * reject such an attempt with EINVAL.
  *
  * An application can use sctp_bindx(SCTP_BINDX_ADD_ADDR) to associate
  * additional addresses with an endpoint after calling bind().  Or use
  * sctp_bindx(SCTP_BINDX_REM_ADDR) to remove some addresses a listening
  * socket is associated with so that no new association accepted will be
  * associated with those addresses. If the endpoint supports dynamic
  * address a SCTP_BINDX_REM_ADDR or SCTP_BINDX_ADD_ADDR may cause a
  * endpoint to send the appropriate message to the peer to change the
  * peers address lists.
  *
  * Adding and removing addresses from a connected association is
  * optional functionality. Implementations that do not support this
  * functionality should return EOPNOTSUPP.
  *
  * Basically do nothing but copying the addresses from user to kernel
  * land and invoking either sctp_bindx_add() or sctp_bindx_rem() on the sk.
  * This is used for tunneling the sctp_bindx() request through sctp_setsockopt()
  * from userspace.
  *
  * On exit there is no need to do sockfd_put(), sys_setsockopt() does
  * it.
  *
  * sk        The sk of the socket
  * addrs     The pointer to the addresses
  * addrssize Size of the addrs buffer
  * op        Operation to perform (add or remove, see the flags of
  *           sctp_bindx)
  *
  * Returns 0 if ok, <0 errno code on error.
  */
 static int sctp_setsockopt_bindx(struct sock *sk, struct sockaddr *addrs,
                  int addrs_size, int op)
 {
     int err;
     int addrcnt = 0;
     int walk_size = 0;
     struct sockaddr *sa_addr;
     void *addr_buf = addrs;
     struct sctp_af *af;
 
     pr_debug("%s: sk:%p addrs:%p addrs_size:%d opt:%d\n",
          __func__, sk, addr_buf, addrs_size, op);
 
     if (unlikely(addrs_size <= 0))
         return -EINVAL;
 
     /* Walk through the addrs buffer and count the number of addresses. */
     while (walk_size < addrs_size) {
         if (walk_size + sizeof(sa_family_t) > addrs_size)
             return -EINVAL;
 
         sa_addr = addr_buf;
         af = sctp_get_af_specific(sa_addr->sa_family);
 
         /* If the address family is not supported or if this address
          * causes the address buffer to overflow return EINVAL.
          */
         if (!af || (walk_size + af->sockaddr_len) > addrs_size)
             return -EINVAL;
         addrcnt++;
         addr_buf += af->sockaddr_len;
         walk_size += af->sockaddr_len;
     }
 
     /* Do the work. */
     switch (op) {
     case SCTP_BINDX_ADD_ADDR:
         /* Allow security module to validate bindx addresses. */
         err = security_sctp_bind_connect(sk, SCTP_SOCKOPT_BINDX_ADD,
                          addrs, addrs_size);
         if (err)
             return err;
         err = sctp_bindx_add(sk, addrs, addrcnt);
         if (err)
             return err;
         return sctp_send_asconf_add_ip(sk, addrs, addrcnt);
     case SCTP_BINDX_REM_ADDR:
         err = sctp_bindx_rem(sk, addrs, addrcnt);
         if (err)
             return err;
         return sctp_send_asconf_del_ip(sk, addrs, addrcnt);
 
     default:
         return -EINVAL;
     }
 }
 
 static int sctp_bind_add(struct sock *sk, struct sockaddr *addrs,
         int addrlen)
 {
     int err;
 
     lock_sock(sk);
     err = sctp_setsockopt_bindx(sk, addrs, addrlen, SCTP_BINDX_ADD_ADDR);
     release_sock(sk);
     return err;
 }
 
 static int sctp_connect_new_asoc(struct sctp_endpoint *ep,
                  const union sctp_addr *daddr,
                  const struct sctp_initmsg *init,
                  struct sctp_transport **tp)
 {
     struct sctp_association *asoc;
     struct sock *sk = ep->base.sk;
     struct net *net = sock_net(sk);
     enum sctp_scope scope;
     int err;
 
     if (sctp_endpoint_is_peeled_off(ep, daddr))
         return -EADDRNOTAVAIL;
 
     if (!ep->base.bind_addr.port) {
         if (sctp_autobind(sk))
             return -EAGAIN;
     } else {
         if (inet_port_requires_bind_service(net, ep->base.bind_addr.port) &&
             !ns_capable(net->user_ns, CAP_NET_BIND_SERVICE))
             return -EACCES;
     }
 
     scope = sctp_scope(daddr);
     asoc = sctp_association_new(ep, sk, scope, GFP_KERNEL);
     if (!asoc)
         return -ENOMEM;
 
     err = sctp_assoc_set_bind_addr_from_ep(asoc, scope, GFP_KERNEL);
     if (err < 0)
         goto free;
 
     *tp = sctp_assoc_add_peer(asoc, daddr, GFP_KERNEL, SCTP_UNKNOWN);
     if (!*tp) {
         err = -ENOMEM;
         goto free;
     }
 
     if (!init)
         return 0;
 
     if (init->sinit_num_ostreams) {
         __u16 outcnt = init->sinit_num_ostreams;
 
         asoc->c.sinit_num_ostreams = outcnt;
         /* outcnt has been changed, need to re-init stream */
         err = sctp_stream_init(&asoc->stream, outcnt, 0, GFP_KERNEL);
         if (err)
             goto free;
     }
 
     if (init->sinit_max_instreams)
         asoc->c.sinit_max_instreams = init->sinit_max_instreams;
 
     if (init->sinit_max_attempts)
         asoc->max_init_attempts = init->sinit_max_attempts;
 
     if (init->sinit_max_init_timeo)
         asoc->max_init_timeo =
             msecs_to_jiffies(init->sinit_max_init_timeo);
 
     return 0;
 free:
     sctp_association_free(asoc);
     return err;
 }
 
 static int sctp_connect_add_peer(struct sctp_association *asoc,
                  union sctp_addr *daddr, int addr_len)
 {
     struct sctp_endpoint *ep = asoc->ep;
     struct sctp_association *old;
     struct sctp_transport *t;
     int err;
 
     err = sctp_verify_addr(ep->base.sk, daddr, addr_len);
     if (err)
         return err;
 
     old = sctp_endpoint_lookup_assoc(ep, daddr, &t);
     if (old && old != asoc)
         return old->state >= SCTP_STATE_ESTABLISHED ? -EISCONN
                                 : -EALREADY;
 
     if (sctp_endpoint_is_peeled_off(ep, daddr))
         return -EADDRNOTAVAIL;
 
     t = sctp_assoc_add_peer(asoc, daddr, GFP_KERNEL, SCTP_UNKNOWN);
     if (!t)
         return -ENOMEM;
 
     return 0;
 }
 
 /* __sctp_connect(struct sock* sk, struct sockaddr *kaddrs, int addrs_size)
  *
  * Common routine for handling connect() and sctp_connectx().
  * Connect will come in with just a single address.
  */
 static int __sctp_connect(struct sock *sk, struct sockaddr *kaddrs,
               int addrs_size, int flags, sctp_assoc_t *assoc_id)
 {
     struct sctp_sock *sp = sctp_sk(sk);
     struct sctp_endpoint *ep = sp->ep;
     struct sctp_transport *transport;
     struct sctp_association *asoc;
     void *addr_buf = kaddrs;
     union sctp_addr *daddr;
     struct sctp_af *af;
     int walk_size, err;
     long timeo;
 
     if (sctp_sstate(sk, ESTABLISHED) || sctp_sstate(sk, CLOSING) ||
         (sctp_style(sk, TCP) && sctp_sstate(sk, LISTENING)))
         return -EISCONN;
 
     daddr = addr_buf;
     af = sctp_get_af_specific(daddr->sa.sa_family);
     if (!af || af->sockaddr_len > addrs_size)
         return -EINVAL;
 
     err = sctp_verify_addr(sk, daddr, af->sockaddr_len);
     if (err)
         return err;
 
     asoc = sctp_endpoint_lookup_assoc(ep, daddr, &transport);
     if (asoc)
         return asoc->state >= SCTP_STATE_ESTABLISHED ? -EISCONN
                                  : -EALREADY;
 
     err = sctp_connect_new_asoc(ep, daddr, NULL, &transport);
     if (err)
         return err;
     asoc = transport->asoc;
 
     addr_buf += af->sockaddr_len;
     walk_size = af->sockaddr_len;
     while (walk_size < addrs_size) {
         err = -EINVAL;
         if (walk_size + sizeof(sa_family_t) > addrs_size)
             goto out_free;
 
         daddr = addr_buf;
         af = sctp_get_af_specific(daddr->sa.sa_family);
         if (!af || af->sockaddr_len + walk_size > addrs_size)
             goto out_free;
 
         if (asoc->peer.port != ntohs(daddr->v4.sin_port))
             goto out_free;
 
         err = sctp_connect_add_peer(asoc, daddr, af->sockaddr_len);
         if (err)
             goto out_free;
 
         addr_buf  += af->sockaddr_len;
         walk_size += af->sockaddr_len;
     }
 
     /* In case the user of sctp_connectx() wants an association
      * id back, assign one now.
      */
     if (assoc_id) {
         err = sctp_assoc_set_id(asoc, GFP_KERNEL);
         if (err < 0)
             goto out_free;
     }
 
     err = sctp_primitive_ASSOCIATE(sock_net(sk), asoc, NULL);
     if (err < 0)
         goto out_free;
 
     /* Initialize sk's dport and daddr for getpeername() */
     inet_sk(sk)->inet_dport = htons(asoc->peer.port);
     sp->pf->to_sk_daddr(daddr, sk);
     sk->sk_err = 0;
 
     if (assoc_id)
         *assoc_id = asoc->assoc_id;
 
     timeo = sock_sndtimeo(sk, flags & O_NONBLOCK);
     return sctp_wait_for_connect(asoc, &timeo);
 
 out_free:
     pr_debug("%s: took out_free path with asoc:%p kaddrs:%p err:%d\n",
          __func__, asoc, kaddrs, err);
     sctp_association_free(asoc);
     return err;
 }
 
 /* Helper for tunneling sctp_connectx() requests through sctp_setsockopt()
  *
  * API 8.9
  * int sctp_connectx(int sd, struct sockaddr *addrs, int addrcnt,
  *          sctp_assoc_t *asoc);
  *
  * If sd is an IPv4 socket, the addresses passed must be IPv4 addresses.
  * If the sd is an IPv6 socket, the addresses passed can either be IPv4
  * or IPv6 addresses.
  *
  * A single address may be specified as INADDR_ANY or IN6ADDR_ANY, see
  * Section 3.1.2 for this usage.
  *
  * addrs is a pointer to an array of one or more socket addresses. Each
  * address is contained in its appropriate structure (i.e. struct
  * sockaddr_in or struct sockaddr_in6) the family of the address type
  * must be used to distengish the address length (note that this
  * representation is termed a "packed array" of addresses). The caller
  * specifies the number of addresses in the array with addrcnt.
  *
  * On success, sctp_connectx() returns 0. It also sets the assoc_id to
  * the association id of the new association.  On failure, sctp_connectx()
  * returns -1, and sets errno to the appropriate error code.  The assoc_id
  * is not touched by the kernel.
  *
  * For SCTP, the port given in each socket address must be the same, or
  * sctp_connectx() will fail, setting errno to EINVAL.
  *
  * An application can use sctp_connectx to initiate an association with
  * an endpoint that is multi-homed.  Much like sctp_bindx() this call
  * allows a caller to specify multiple addresses at which a peer can be
  * reached.  The way the SCTP stack uses the list of addresses to set up
  * the association is implementation dependent.  This function only
  * specifies that the stack will try to make use of all the addresses in
  * the list when needed.
  *
  * Note that the list of addresses passed in is only used for setting up
  * the association.  It does not necessarily equal the set of addresses
  * the peer uses for the resulting association.  If the caller wants to
  * find out the set of peer addresses, it must use sctp_getpaddrs() to
  * retrieve them after the association has been set up.
  *
  * Basically do nothing but copying the addresses from user to kernel
  * land and invoking either sctp_connectx(). This is used for tunneling
  * the sctp_connectx() request through sctp_setsockopt() from userspace.
  *
  * On exit there is no need to do sockfd_put(), sys_setsockopt() does
  * it.
  *
  * sk        The sk of the socket
  * addrs     The pointer to the addresses
  * addrssize Size of the addrs buffer
  *
  * Returns >=0 if ok, <0 errno code on error.
  */
 static int __sctp_setsockopt_connectx(struct sock *sk, struct sockaddr *kaddrs,
                       int addrs_size, sctp_assoc_t *assoc_id)
 {
     int err = 0, flags = 0;
 
     pr_debug("%s: sk:%p addrs:%p addrs_size:%d\n",
          __func__, sk, kaddrs, addrs_size);
 
     /* make sure the 1st addr's sa_family is accessible later */
     if (unlikely(addrs_size < sizeof(sa_family_t)))
         return -EINVAL;
 
     /* Allow security module to validate connectx addresses. */
     err = security_sctp_bind_connect(sk, SCTP_SOCKOPT_CONNECTX,
                      (struct sockaddr *)kaddrs,
                       addrs_size);
     if (err)
         return err;
 
     /* in-kernel sockets don't generally have a file allocated to them
      * if all they do is call sock_create_kern().
      */
     if (sk->sk_socket->file)
         flags = sk->sk_socket->file->f_flags;
 
     return __sctp_connect(sk, kaddrs, addrs_size, flags, assoc_id);
 }
 
 /*
  * This is an older interface.  It's kept for backward compatibility
  * to the option that doesn't provide association id.
  */
 static int sctp_setsockopt_connectx_old(struct sock *sk,
                     struct sockaddr *kaddrs,
                     int addrs_size)
 {
     return __sctp_setsockopt_connectx(sk, kaddrs, addrs_size, NULL);
 }
 
 /*
  * New interface for the API.  The since the API is done with a socket
  * option, to make it simple we feed back the association id is as a return
  * indication to the call.  Error is always negative and association id is
  * always positive.
  */
 static int sctp_setsockopt_connectx(struct sock *sk,
                     struct sockaddr *kaddrs,
                     int addrs_size)
 {
     sctp_assoc_t assoc_id = 0;
     int err = 0;
 
     err = __sctp_setsockopt_connectx(sk, kaddrs, addrs_size, &assoc_id);
 
     if (err)
         return err;
     else
         return assoc_id;
 }
 
 /*
  * New (hopefully final) interface for the API.
  * We use the sctp_getaddrs_old structure so that use-space library
  * can avoid any unnecessary allocations. The only different part
  * is that we store the actual length of the address buffer into the
  * addrs_num structure member. That way we can re-use the existing
  * code.
  */
 #ifdef CONFIG_COMPAT
 struct compat_sctp_getaddrs_old {
     sctp_assoc_t    assoc_id;
     s32     addr_num;
     compat_uptr_t   addrs;      /* struct sockaddr * */
 };
 #endif
 
 static int sctp_getsockopt_connectx3(struct sock *sk, int len,
                      char __user *optval,
                      int __user *optlen)
 {
     struct sctp_getaddrs_old param;
     sctp_assoc_t assoc_id = 0;
     struct sockaddr *kaddrs;
     int err = 0;
 
 #ifdef CONFIG_COMPAT
     if (in_compat_syscall()) {
         struct compat_sctp_getaddrs_old param32;
 
         if (len < sizeof(param32))
             return -EINVAL;
         if (copy_from_user(&param32, optval, sizeof(param32)))
             return -EFAULT;
 
         param.assoc_id = param32.assoc_id;
         param.addr_num = param32.addr_num;
         param.addrs = compat_ptr(param32.addrs);
     } else
 #endif
     {
         if (len < sizeof(param))
             return -EINVAL;
         if (copy_from_user(&param, optval, sizeof(param)))
             return -EFAULT;
     }
 
     kaddrs = memdup_user(param.addrs, param.addr_num);
     if (IS_ERR(kaddrs))
         return PTR_ERR(kaddrs);
 
     err = __sctp_setsockopt_connectx(sk, kaddrs, param.addr_num, &assoc_id);
     kfree(kaddrs);
     if (err == 0 || err == -EINPROGRESS) {
         if (copy_to_user(optval, &assoc_id, sizeof(assoc_id)))
             return -EFAULT;
         if (put_user(sizeof(assoc_id), optlen))
             return -EFAULT;
     }
 
     return err;
 }
 
 /* API 3.1.4 close() - UDP Style Syntax
  * Applications use close() to perform graceful shutdown (as described in
  * Section 10.1 of [SCTP]) on ALL the associations currently represented
  * by a UDP-style socket.
  *
  * The syntax is
  *
  *   ret = close(int sd);
  *
  *   sd      - the socket descriptor of the associations to be closed.
  *
  * To gracefully shutdown a specific association represented by the
  * UDP-style socket, an application should use the sendmsg() call,
  * passing no user data, but including the appropriate flag in the
  * ancillary data (see Section xxxx).
  *
  * If sd in the close() call is a branched-off socket representing only
  * one association, the shutdown is performed on that association only.
  *
  * 4.1.6 close() - TCP Style Syntax
  *
  * Applications use close() to gracefully close down an association.
  *
  * The syntax is:
  *
  *    int close(int sd);
  *
  *      sd      - the socket descriptor of the association to be closed.
  *
  * After an application calls close() on a socket descriptor, no further
  * socket operations will succeed on that descriptor.
  *
  * API 7.1.4 SO_LINGER
  *
  * An application using the TCP-style socket can use this option to
  * perform the SCTP ABORT primitive.  The linger option structure is:
  *
  *  struct  linger {
  *     int     l_onoff;                // option on/off
  *     int     l_linger;               // linger time
  * };
  *
  * To enable the option, set l_onoff to 1.  If the l_linger value is set
  * to 0, calling close() is the same as the ABORT primitive.  If the
  * value is set to a negative value, the setsockopt() call will return
  * an error.  If the value is set to a positive value linger_time, the
  * close() can be blocked for at most linger_time ms.  If the graceful
  * shutdown phase does not finish during this period, close() will
  * return but the graceful shutdown phase continues in the system.
  */
 static void sctp_close(struct sock *sk, long timeout)
 {
     struct net *net = sock_net(sk);
     struct sctp_endpoint *ep;
     struct sctp_association *asoc;
     struct list_head *pos, *temp;
     unsigned int data_was_unread;
 
     pr_debug("%s: sk:%p, timeout:%ld\n", __func__, sk, timeout);
 
     lock_sock_nested(sk, SINGLE_DEPTH_NESTING);
     sk->sk_shutdown = SHUTDOWN_MASK;
     inet_sk_set_state(sk, SCTP_SS_CLOSING);
 
     ep = sctp_sk(sk)->ep;
 
     /* Clean up any skbs sitting on the receive queue.  */
     data_was_unread = sctp_queue_purge_ulpevents(&sk->sk_receive_queue);
     data_was_unread += sctp_queue_purge_ulpevents(&sctp_sk(sk)->pd_lobby);
 
     /* Walk all associations on an endpoint.  */
     list_for_each_safe(pos, temp, &ep->asocs) {
         asoc = list_entry(pos, struct sctp_association, asocs);
 
         if (sctp_style(sk, TCP)) {
             /* A closed association can still be in the list if
              * it belongs to a TCP-style listening socket that is
              * not yet accepted. If so, free it. If not, send an
              * ABORT or SHUTDOWN based on the linger options.
              */
             if (sctp_state(asoc, CLOSED)) {
                 sctp_association_free(asoc);
                 continue;
             }
         }
 
         if (data_was_unread || !skb_queue_empty(&asoc->ulpq.lobby) ||
             !skb_queue_empty(&asoc->ulpq.reasm) ||
             !skb_queue_empty(&asoc->ulpq.reasm_uo) ||
             (sock_flag(sk, SOCK_LINGER) && !sk->sk_lingertime)) {
             struct sctp_chunk *chunk;
 
             chunk = sctp_make_abort_user(asoc, NULL, 0);
             sctp_primitive_ABORT(net, asoc, chunk);
         } else
             sctp_primitive_SHUTDOWN(net, asoc, NULL);
     }
 
     /* On a TCP-style socket, block for at most linger_time if set. */
     if (sctp_style(sk, TCP) && timeout)
         sctp_wait_for_close(sk, timeout);
 
     /* This will run the backlog queue.  */
     release_sock(sk);
 
     /* Supposedly, no process has access to the socket, but
      * the net layers still may.
      * Also, sctp_destroy_sock() needs to be called with addr_wq_lock
      * held and that should be grabbed before socket lock.
      */
     spin_lock_bh(&net->sctp.addr_wq_lock);
     bh_lock_sock_nested(sk);
 
     /* Hold the sock, since sk_common_release() will put sock_put()
      * and we have just a little more cleanup.
      */
     sock_hold(sk);
     sk_common_release(sk);
 
     bh_unlock_sock(sk);
     spin_unlock_bh(&net->sctp.addr_wq_lock);
 
     sock_put(sk);
 
     SCTP_DBG_OBJCNT_DEC(sock);
 }
 
 /* Handle EPIPE error. */
 static int sctp_error(struct sock *sk, int flags, int err)
 {
     if (err == -EPIPE)
         err = sock_error(sk) ? : -EPIPE;
     if (err == -EPIPE && !(flags & MSG_NOSIGNAL))
         send_sig(SIGPIPE, current, 0);
     return err;
 }
 
 /* API 3.1.3 sendmsg() - UDP Style Syntax
  *
  * An application uses sendmsg() and recvmsg() calls to transmit data to
  * and receive data from its peer.
  *
  *  ssize_t sendmsg(int socket, const struct msghdr *message,
  *                  int flags);
  *
  *  socket  - the socket descriptor of the endpoint.
  *  message - pointer to the msghdr structure which contains a single
  *            user message and possibly some ancillary data.
  *
  *            See Section 5 for complete description of the data
  *            structures.
  *
  *  flags   - flags sent or received with the user message, see Section
  *            5 for complete description of the flags.
  *
  * Note:  This function could use a rewrite especially when explicit
  * connect support comes in.
  */
 /* BUG:  We do not implement the equivalent of sk_stream_wait_memory(). */
 
 static int sctp_msghdr_parse(const struct msghdr *msg,
                  struct sctp_cmsgs *cmsgs);
 
 static int sctp_sendmsg_parse(struct sock *sk, struct sctp_cmsgs *cmsgs,
                   struct sctp_sndrcvinfo *srinfo,
                   const struct msghdr *msg, size_t msg_len)
 {
     __u16 sflags;
     int err;
 
     if (sctp_sstate(sk, LISTENING) && sctp_style(sk, TCP))
         return -EPIPE;
 
     if (msg_len > sk->sk_sndbuf)
         return -EMSGSIZE;
 
     memset(cmsgs, 0, sizeof(*cmsgs));
     err = sctp_msghdr_parse(msg, cmsgs);
     if (err) {
         pr_debug("%s: msghdr parse err:%x\n", __func__, err);
         return err;
     }
 
     memset(srinfo, 0, sizeof(*srinfo));
     if (cmsgs->srinfo) {
         srinfo->sinfo_stream = cmsgs->srinfo->sinfo_stream;
         srinfo->sinfo_flags = cmsgs->srinfo->sinfo_flags;
         srinfo->sinfo_ppid = cmsgs->srinfo->sinfo_ppid;
         srinfo->sinfo_context = cmsgs->srinfo->sinfo_context;
         srinfo->sinfo_assoc_id = cmsgs->srinfo->sinfo_assoc_id;
         srinfo->sinfo_timetolive = cmsgs->srinfo->sinfo_timetolive;
     }
 
     if (cmsgs->sinfo) {
         srinfo->sinfo_stream = cmsgs->sinfo->snd_sid;
         srinfo->sinfo_flags = cmsgs->sinfo->snd_flags;
         srinfo->sinfo_ppid = cmsgs->sinfo->snd_ppid;
         srinfo->sinfo_context = cmsgs->sinfo->snd_context;
         srinfo->sinfo_assoc_id = cmsgs->sinfo->snd_assoc_id;
     }
 
     if (cmsgs->prinfo) {
         srinfo->sinfo_timetolive = cmsgs->prinfo->pr_value;
         SCTP_PR_SET_POLICY(srinfo->sinfo_flags,
                    cmsgs->prinfo->pr_policy);
     }
 
     sflags = srinfo->sinfo_flags;
     if (!sflags && msg_len)
         return 0;
 
     if (sctp_style(sk, TCP) && (sflags & (SCTP_EOF | SCTP_ABORT)))
         return -EINVAL;
 
     if (((sflags & SCTP_EOF) && msg_len > 0) ||
         (!(sflags & (SCTP_EOF | SCTP_ABORT)) && msg_len == 0))
         return -EINVAL;
 
     if ((sflags & SCTP_ADDR_OVER) && !msg->msg_name)
         return -EINVAL;
 
     return 0;
 }
 
 static int sctp_sendmsg_new_asoc(struct sock *sk, __u16 sflags,
                  struct sctp_cmsgs *cmsgs,
                  union sctp_addr *daddr,
                  struct sctp_transport **tp)
 {
     struct sctp_endpoint *ep = sctp_sk(sk)->ep;
     struct sctp_association *asoc;
     struct cmsghdr *cmsg;
     __be32 flowinfo = 0;
     struct sctp_af *af;
     int err;
 
     *tp = NULL;
 
     if (sflags & (SCTP_EOF | SCTP_ABORT))
         return -EINVAL;
 
     if (sctp_style(sk, TCP) && (sctp_sstate(sk, ESTABLISHED) ||
                     sctp_sstate(sk, CLOSING)))
         return -EADDRNOTAVAIL;
 
     /* Label connection socket for first association 1-to-many
      * style for client sequence socket()->sendmsg(). This
      * needs to be done before sctp_assoc_add_peer() as that will
      * set up the initial packet that needs to account for any
      * security ip options (CIPSO/CALIPSO) added to the packet.
      */
     af = sctp_get_af_specific(daddr->sa.sa_family);
     if (!af)
         return -EINVAL;
     err = security_sctp_bind_connect(sk, SCTP_SENDMSG_CONNECT,
                      (struct sockaddr *)daddr,
                      af->sockaddr_len);
     if (err < 0)
         return err;
 
     err = sctp_connect_new_asoc(ep, daddr, cmsgs->init, tp);
     if (err)
         return err;
     asoc = (*tp)->asoc;
 
     if (!cmsgs->addrs_msg)
         return 0;
 
     if (daddr->sa.sa_family == AF_INET6)
         flowinfo = daddr->v6.sin6_flowinfo;
 
     /* sendv addr list parse */
     for_each_cmsghdr(cmsg, cmsgs->addrs_msg) {
         union sctp_addr _daddr;
         int dlen;
 
         if (cmsg->cmsg_level != IPPROTO_SCTP ||
             (cmsg->cmsg_type != SCTP_DSTADDRV4 &&
              cmsg->cmsg_type != SCTP_DSTADDRV6))
             continue;
 
         daddr = &_daddr;
         memset(daddr, 0, sizeof(*daddr));
         dlen = cmsg->cmsg_len - sizeof(struct cmsghdr);
         if (cmsg->cmsg_type == SCTP_DSTADDRV4) {
             if (dlen < sizeof(struct in_addr)) {
                 err = -EINVAL;
                 goto free;
             }
 
             dlen = sizeof(struct in_addr);
             daddr->v4.sin_family = AF_INET;
             daddr->v4.sin_port = htons(asoc->peer.port);
             memcpy(&daddr->v4.sin_addr, CMSG_DATA(cmsg), dlen);
         } else {
             if (dlen < sizeof(struct in6_addr)) {
                 err = -EINVAL;
                 goto free;
             }
 
             dlen = sizeof(struct in6_addr);
             daddr->v6.sin6_flowinfo = flowinfo;
             daddr->v6.sin6_family = AF_INET6;
             daddr->v6.sin6_port = htons(asoc->peer.port);
             memcpy(&daddr->v6.sin6_addr, CMSG_DATA(cmsg), dlen);
         }
 
         err = sctp_connect_add_peer(asoc, daddr, sizeof(*daddr));
         if (err)
             goto free;
     }
 
     return 0;
 
 free:
     sctp_association_free(asoc);
     return err;
 }
 
 static int sctp_sendmsg_check_sflags(struct sctp_association *asoc,
                      __u16 sflags, struct msghdr *msg,
                      size_t msg_len)
 {
     struct sock *sk = asoc->base.sk;
     struct net *net = sock_net(sk);
 
     if (sctp_state(asoc, CLOSED) && sctp_style(sk, TCP))
         return -EPIPE;
 
     if ((sflags & SCTP_SENDALL) && sctp_style(sk, UDP) &&
         !sctp_state(asoc, ESTABLISHED))
         return 0;
 
     if (sflags & SCTP_EOF) {
         pr_debug("%s: shutting down association:%p\n", __func__, asoc);
         sctp_primitive_SHUTDOWN(net, asoc, NULL);
 
         return 0;
     }
 
     if (sflags & SCTP_ABORT) {
         struct sctp_chunk *chunk;
 
         chunk = sctp_make_abort_user(asoc, msg, msg_len);
         if (!chunk)
             return -ENOMEM;
 
         pr_debug("%s: aborting association:%p\n", __func__, asoc);
         sctp_primitive_ABORT(net, asoc, chunk);
         iov_iter_revert(&msg->msg_iter, msg_len);
 
         return 0;
     }
 
     return 1;
 }
 
 static int sctp_sendmsg_to_asoc(struct sctp_association *asoc,
                 struct msghdr *msg, size_t msg_len,
                 struct sctp_transport *transport,
                 struct sctp_sndrcvinfo *sinfo)
 {
     struct sock *sk = asoc->base.sk;
     struct sctp_sock *sp = sctp_sk(sk);
     struct net *net = sock_net(sk);
     struct sctp_datamsg *datamsg;
     bool wait_connect = false;
     struct sctp_chunk *chunk;
     long timeo;
     int err;
 
     if (sinfo->sinfo_stream >= asoc->stream.outcnt) {
         err = -EINVAL;
         goto err;
     }
 
     if (unlikely(!SCTP_SO(&asoc->stream, sinfo->sinfo_stream)->ext)) {
         err = sctp_stream_init_ext(&asoc->stream, sinfo->sinfo_stream);
         if (err)
             goto err;
     }
 
     if (sp->disable_fragments && msg_len > asoc->frag_point) {
         err = -EMSGSIZE;
         goto err;
     }
 
     if (asoc->pmtu_pending) {
         if (sp->param_flags & SPP_PMTUD_ENABLE)
             sctp_assoc_sync_pmtu(asoc);
         asoc->pmtu_pending = 0;
     }
 
     if (sctp_wspace(asoc) < (int)msg_len)
         sctp_prsctp_prune(asoc, sinfo, msg_len - sctp_wspace(asoc));
 
     if (sctp_wspace(asoc) <= 0 || !sk_wmem_schedule(sk, msg_len)) {
         timeo = sock_sndtimeo(sk, msg->msg_flags & MSG_DONTWAIT);
         err = sctp_wait_for_sndbuf(asoc, &timeo, msg_len);
         if (err)
             goto err;
     }
 
     if (sctp_state(asoc, CLOSED)) {
         err = sctp_primitive_ASSOCIATE(net, asoc, NULL);
         if (err)
             goto err;
 
         if (asoc->ep->intl_enable) {
             timeo = sock_sndtimeo(sk, 0);
             err = sctp_wait_for_connect(asoc, &timeo);
             if (err) {
                 err = -ESRCH;
                 goto err;
             }
         } else {
             wait_connect = true;
         }
 
         pr_debug("%s: we associated primitively\n", __func__);
     }
 
     datamsg = sctp_datamsg_from_user(asoc, sinfo, &msg->msg_iter);
     if (IS_ERR(datamsg)) {
         err = PTR_ERR(datamsg);
         goto err;
     }
 
     asoc->force_delay = !!(msg->msg_flags & MSG_MORE);
 
     list_for_each_entry(chunk, &datamsg->chunks, frag_list) {
         sctp_chunk_hold(chunk);
         sctp_set_owner_w(chunk);
         chunk->transport = transport;
     }
 
     err = sctp_primitive_SEND(net, asoc, datamsg);
     if (err) {
         sctp_datamsg_free(datamsg);
         goto err;
     }
 
     pr_debug("%s: we sent primitively\n", __func__);
 
     sctp_datamsg_put(datamsg);
 
     if (unlikely(wait_connect)) {
         timeo = sock_sndtimeo(sk, msg->msg_flags & MSG_DONTWAIT);
         sctp_wait_for_connect(asoc, &timeo);
     }
 
     err = msg_len;
 
 err:
     return err;
 }
 
 static union sctp_addr *sctp_sendmsg_get_daddr(struct sock *sk,
                            const struct msghdr *msg,
                            struct sctp_cmsgs *cmsgs)
 {
     union sctp_addr *daddr = NULL;
     int err;
 
     if (!sctp_style(sk, UDP_HIGH_BANDWIDTH) && msg->msg_name) {
         int len = msg->msg_namelen;
 
         if (len > sizeof(*daddr))
             len = sizeof(*daddr);
 
         daddr = (union sctp_addr *)msg->msg_name;
 
         err = sctp_verify_addr(sk, daddr, len);
         if (err)
             return ERR_PTR(err);
     }
 
     return daddr;
 }
 
 static void sctp_sendmsg_update_sinfo(struct sctp_association *asoc,
                       struct sctp_sndrcvinfo *sinfo,
                       struct sctp_cmsgs *cmsgs)
 {
     if (!cmsgs->srinfo && !cmsgs->sinfo) {
         sinfo->sinfo_stream = asoc->default_stream;
         sinfo->sinfo_ppid = asoc->default_ppid;
         sinfo->sinfo_context = asoc->default_context;
         sinfo->sinfo_assoc_id = sctp_assoc2id(asoc);
 
         if (!cmsgs->prinfo)
             sinfo->sinfo_flags = asoc->default_flags;
     }
 
     if (!cmsgs->srinfo && !cmsgs->prinfo)
         sinfo->sinfo_timetolive = asoc->default_timetolive;
 
     if (cmsgs->authinfo) {
         /* Reuse sinfo_tsn to indicate that authinfo was set and
          * sinfo_ssn to save the keyid on tx path.
          */
         sinfo->sinfo_tsn = 1;
         sinfo->sinfo_ssn = cmsgs->authinfo->auth_keynumber;
     }
 }
 
 static int sctp_sendmsg(struct sock *sk, struct msghdr *msg, size_t msg_len)
 {
     struct sctp_endpoint *ep = sctp_sk(sk)->ep;
     struct sctp_transport *transport = NULL;
     struct sctp_sndrcvinfo _sinfo, *sinfo;
     struct sctp_association *asoc, *tmp;
     struct sctp_cmsgs cmsgs;
     union sctp_addr *daddr;
     bool new = false;
     __u16 sflags;
     int err;
 
     /* Parse and get snd_info */
     err = sctp_sendmsg_parse(sk, &cmsgs, &_sinfo, msg, msg_len);
     if (err)
         goto out;
 
     sinfo  = &_sinfo;
     sflags = sinfo->sinfo_flags;
 
     /* Get daddr from msg */
     daddr = sctp_sendmsg_get_daddr(sk, msg, &cmsgs);
     if (IS_ERR(daddr)) {
         err = PTR_ERR(daddr);
         goto out;
     }
 
     lock_sock(sk);
 
     /* SCTP_SENDALL process */
     if ((sflags & SCTP_SENDALL) && sctp_style(sk, UDP)) {
         list_for_each_entry_safe(asoc, tmp, &ep->asocs, asocs) {
             err = sctp_sendmsg_check_sflags(asoc, sflags, msg,
                             msg_len);
             if (err == 0)
                 continue;
             if (err < 0)
                 goto out_unlock;
 
             sctp_sendmsg_update_sinfo(asoc, sinfo, &cmsgs);
 
             err = sctp_sendmsg_to_asoc(asoc, msg, msg_len,
                            NULL, sinfo);
             if (err < 0)
                 goto out_unlock;
 
             iov_iter_revert(&msg->msg_iter, err);
         }
 
         goto out_unlock;
     }
 
     /* Get and check or create asoc */
     if (daddr) {
         asoc = sctp_endpoint_lookup_assoc(ep, daddr, &transport);
         if (asoc) {
             err = sctp_sendmsg_check_sflags(asoc, sflags, msg,
                             msg_len);
             if (err <= 0)
                 goto out_unlock;
         } else {
             err = sctp_sendmsg_new_asoc(sk, sflags, &cmsgs, daddr,
                             &transport);
             if (err)
                 goto out_unlock;
 
             asoc = transport->asoc;
             new = true;
         }
 
         if (!sctp_style(sk, TCP) && !(sflags & SCTP_ADDR_OVER))
             transport = NULL;
     } else {
         asoc = sctp_id2assoc(sk, sinfo->sinfo_assoc_id);
         if (!asoc) {
             err = -EPIPE;
             goto out_unlock;
         }
 
         err = sctp_sendmsg_check_sflags(asoc, sflags, msg, msg_len);
         if (err <= 0)
             goto out_unlock;
     }
 
     /* Update snd_info with the asoc */
     sctp_sendmsg_update_sinfo(asoc, sinfo, &cmsgs);
 
     /* Send msg to the asoc */
     err = sctp_sendmsg_to_asoc(asoc, msg, msg_len, transport, sinfo);
     if (err < 0 && err != -ESRCH && new)
         sctp_association_free(asoc);
 
 out_unlock:
     release_sock(sk);
 out:
     return sctp_error(sk, msg->msg_flags, err);
 }
 
 /* This is an extended version of skb_pull() that removes the data from the
  * start of a skb even when data is spread across the list of skb's in the
  * frag_list. len specifies the total amount of data that needs to be removed.
  * when 'len' bytes could be removed from the skb, it returns 0.
  * If 'len' exceeds the total skb length,  it returns the no. of bytes that
  * could not be removed.
  */
 static int sctp_skb_pull(struct sk_buff *skb, int len)
 {
     struct sk_buff *list;
     int skb_len = skb_headlen(skb);
     int rlen;
 
     if (len <= skb_len) {
         __skb_pull(skb, len);
         return 0;
     }
     len -= skb_len;
     __skb_pull(skb, skb_len);
 
     skb_walk_frags(skb, list) {
         rlen = sctp_skb_pull(list, len);
         skb->len -= (len-rlen);
         skb->data_len -= (len-rlen);
 
         if (!rlen)
             return 0;
 
         len = rlen;
     }
 
     return len;
 }
 
 /* API 3.1.3  recvmsg() - UDP Style Syntax
  *
  *  ssize_t recvmsg(int socket, struct msghdr *message,
  *                    int flags);
  *
  *  socket  - the socket descriptor of the endpoint.
  *  message - pointer to the msghdr structure which contains a single
  *            user message and possibly some ancillary data.
  *
  *            See Section 5 for complete description of the data
  *            structures.
  *
  *  flags   - flags sent or received with the user message, see Section
  *            5 for complete description of the flags.
  */
 static int sctp_recvmsg(struct sock *sk, struct msghdr *msg, size_t len,
             int flags, int *addr_len)
 {
     struct sctp_ulpevent *event = NULL;
     struct sctp_sock *sp = sctp_sk(sk);
     struct sk_buff *skb, *head_skb;
     int copied;
     int err = 0;
     int skb_len;
 
     pr_debug("%s: sk:%p, msghdr:%p, len:%zd, flags:0x%x, addr_len:%p)\n",
          __func__, sk, msg, len, flags, addr_len);
 
     lock_sock(sk);
 
     if (sctp_style(sk, TCP) && !sctp_sstate(sk, ESTABLISHED) &&
         !sctp_sstate(sk, CLOSING) && !sctp_sstate(sk, CLOSED)) {
         err = -ENOTCONN;
         goto out;
     }
 
     skb = sctp_skb_recv_datagram(sk, flags, &err);
     if (!skb)
         goto out;
 
     /* Get the total length of the skb including any skb's in the
      * frag_list.
      */
     skb_len = skb->len;
 
     copied = skb_len;
     if (copied > len)
         copied = len;
 
     err = skb_copy_datagram_msg(skb, 0, msg, copied);
 
     event = sctp_skb2event(skb);
 
     if (err)
         goto out_free;
 
     if (event->chunk && event->chunk->head_skb)
         head_skb = event->chunk->head_skb;
     else
         head_skb = skb;
     sock_recv_cmsgs(msg, sk, head_skb);
     if (sctp_ulpevent_is_notification(event)) {
         msg->msg_flags |= MSG_NOTIFICATION;
         sp->pf->event_msgname(event, msg->msg_name, addr_len);
     } else {
         sp->pf->skb_msgname(head_skb, msg->msg_name, addr_len);
     }
 
     /* Check if we allow SCTP_NXTINFO. */
     if (sp->recvnxtinfo)
         sctp_ulpevent_read_nxtinfo(event, msg, sk);
     /* Check if we allow SCTP_RCVINFO. */
     if (sp->recvrcvinfo)
         sctp_ulpevent_read_rcvinfo(event, msg);
     /* Check if we allow SCTP_SNDRCVINFO. */
     if (sctp_ulpevent_type_enabled(sp->subscribe, SCTP_DATA_IO_EVENT))
         sctp_ulpevent_read_sndrcvinfo(event, msg);
 
     err = copied;
 
     /* If skb's length exceeds the user's buffer, update the skb and
      * push it back to the receive_queue so that the next call to
      * recvmsg() will return the remaining data. Don't set MSG_EOR.
      */
     if (skb_len > copied) {
         msg->msg_flags &= ~MSG_EOR;
         if (flags & MSG_PEEK)
             goto out_free;
         sctp_skb_pull(skb, copied);
         skb_queue_head(&sk->sk_receive_queue, skb);
 
         /* When only partial message is copied to the user, increase
          * rwnd by that amount. If all the data in the skb is read,
          * rwnd is updated when the event is freed.
          */
         if (!sctp_ulpevent_is_notification(event))
             sctp_assoc_rwnd_increase(event->asoc, copied);
         goto out;
     } else if ((event->msg_flags & MSG_NOTIFICATION) ||
            (event->msg_flags & MSG_EOR))
         msg->msg_flags |= MSG_EOR;
     else
         msg->msg_flags &= ~MSG_EOR;
 
 out_free:
     if (flags & MSG_PEEK) {
         /* Release the skb reference acquired after peeking the skb in
          * sctp_skb_recv_datagram().
          */
         kfree_skb(skb);
     } else {
         /* Free the event which includes releasing the reference to
          * the owner of the skb, freeing the skb and updating the
          * rwnd.
          */
         sctp_ulpevent_free(event);
     }
 out:
     release_sock(sk);
     return err;
 }
 
 /* 7.1.12 Enable/Disable message fragmentation (SCTP_DISABLE_FRAGMENTS)
  *
  * This option is a on/off flag.  If enabled no SCTP message
  * fragmentation will be performed.  Instead if a message being sent
  * exceeds the current PMTU size, the message will NOT be sent and
  * instead a error will be indicated to the user.
  */
 static int sctp_setsockopt_disable_fragments(struct sock *sk, int *val,
                          unsigned int optlen)
 {
     if (optlen < sizeof(int))
         return -EINVAL;
     sctp_sk(sk)->disable_fragments = (*val == 0) ? 0 : 1;
     return 0;
 }
 
 static int sctp_setsockopt_events(struct sock *sk, __u8 *sn_type,
                   unsigned int optlen)
 {
     struct sctp_sock *sp = sctp_sk(sk);
     struct sctp_association *asoc;
     int i;
 
     if (optlen > sizeof(struct sctp_event_subscribe))
         return -EINVAL;
 
     for (i = 0; i < optlen; i++)
         sctp_ulpevent_type_set(&sp->subscribe, SCTP_SN_TYPE_BASE + i,
                        sn_type[i]);
 
     list_for_each_entry(asoc, &sp->ep->asocs, asocs)
         asoc->subscribe = sctp_sk(sk)->subscribe;
 
     /* At the time when a user app subscribes to SCTP_SENDER_DRY_EVENT,
      * if there is no data to be sent or retransmit, the stack will
      * immediately send up this notification.
      */
     if (sctp_ulpevent_type_enabled(sp->subscribe, SCTP_SENDER_DRY_EVENT)) {
         struct sctp_ulpevent *event;
 
         asoc = sctp_id2assoc(sk, 0);
         if (asoc && sctp_outq_is_empty(&asoc->outqueue)) {
             event = sctp_ulpevent_make_sender_dry_event(asoc,
                     GFP_USER | __GFP_NOWARN);
             if (!event)
                 return -ENOMEM;
 
             asoc->stream.si->enqueue_event(&asoc->ulpq, event);
         }
     }
 
     return 0;
 }
 
 /* 7.1.8 Automatic Close of associations (SCTP_AUTOCLOSE)
  *
  * This socket option is applicable to the UDP-style socket only.  When
  * set it will cause associations that are idle for more than the
  * specified number of seconds to automatically close.  An association
  * being idle is defined an association that has NOT sent or received
  * user data.  The special value of '0' indicates that no automatic
  * close of any associations should be performed.  The option expects an
  * integer defining the number of seconds of idle time before an
  * association is closed.
  */
 static int sctp_setsockopt_autoclose(struct sock *sk, u32 *optval,
                      unsigned int optlen)
 {
     struct sctp_sock *sp = sctp_sk(sk);
     struct net *net = sock_net(sk);
 
     /* Applicable to UDP-style socket only */
     if (sctp_style(sk, TCP))
         return -EOPNOTSUPP;
     if (optlen != sizeof(int))
         return -EINVAL;
 
     sp->autoclose = *optval;
     if (sp->autoclose > net->sctp.max_autoclose)
         sp->autoclose = net->sctp.max_autoclose;
 
     return 0;
 }
 
 /* 7.1.13 Peer Address Parameters (SCTP_PEER_ADDR_PARAMS)
  *
  * Applications can enable or disable heartbeats for any peer address of
  * an association, modify an address's heartbeat interval, force a
  * heartbeat to be sent immediately, and adjust the address's maximum
  * number of retransmissions sent before an address is considered
  * unreachable.  The following structure is used to access and modify an
  * address's parameters:
  *
  *  struct sctp_paddrparams {
  *     sctp_assoc_t            spp_assoc_id;
  *     struct sockaddr_storage spp_address;
  *     uint32_t                spp_hbinterval;
  *     uint16_t                spp_pathmaxrxt;
  *     uint32_t                spp_pathmtu;
  *     uint32_t                spp_sackdelay;
  *     uint32_t                spp_flags;
  *     uint32_t                spp_ipv6_flowlabel;
  *     uint8_t                 spp_dscp;
  * };
  *
  *   spp_assoc_id    - (one-to-many style socket) This is filled in the
  *                     application, and identifies the association for
  *                     this query.
  *   spp_address     - This specifies which address is of interest.
  *   spp_hbinterval  - This contains the value of the heartbeat interval,
  *                     in milliseconds.  If a  value of zero
  *                     is present in this field then no changes are to
  *                     be made to this parameter.
  *   spp_pathmaxrxt  - This contains the maximum number of
  *                     retransmissions before this address shall be
  *                     considered unreachable. If a  value of zero
  *                     is present in this field then no changes are to
  *                     be made to this parameter.
  *   spp_pathmtu     - When Path MTU discovery is disabled the value
  *                     specified here will be the "fixed" path mtu.
  *                     Note that if the spp_address field is empty
  *                     then all associations on this address will
  *                     have this fixed path mtu set upon them.
  *
  *   spp_sackdelay   - When delayed sack is enabled, this value specifies
  *                     the number of milliseconds that sacks will be delayed
  *                     for. This value will apply to all addresses of an
  *                     association if the spp_address field is empty. Note
  *                     also, that if delayed sack is enabled and this
  *                     value is set to 0, no change is made to the last
  *                     recorded delayed sack timer value.
  *
  *   spp_flags       - These flags are used to control various features
  *                     on an association. The flag field may contain
  *                     zero or more of the following options.
  *
  *                     SPP_HB_ENABLE  - Enable heartbeats on the
  *                     specified address. Note that if the address
  *                     field is empty all addresses for the association
  *                     have heartbeats enabled upon them.
  *
  *                     SPP_HB_DISABLE - Disable heartbeats on the
  *                     speicifed address. Note that if the address
  *                     field is empty all addresses for the association
  *                     will have their heartbeats disabled. Note also
  *                     that SPP_HB_ENABLE and SPP_HB_DISABLE are
  *                     mutually exclusive, only one of these two should
  *                     be specified. Enabling both fields will have
  *                     undetermined results.
  *
  *                     SPP_HB_DEMAND - Request a user initiated heartbeat
  *                     to be made immediately.
  *
  *                     SPP_HB_TIME_IS_ZERO - Specify's that the time for
  *                     heartbeat delayis to be set to the value of 0
  *                     milliseconds.
  *
  *                     SPP_PMTUD_ENABLE - This field will enable PMTU
  *                     discovery upon the specified address. Note that
  *                     if the address feild is empty then all addresses
  *                     on the association are effected.
  *
  *                     SPP_PMTUD_DISABLE - This field will disable PMTU
  *                     discovery upon the specified address. Note that
  *                     if the address feild is empty then all addresses
  *                     on the association are effected. Not also that
  *                     SPP_PMTUD_ENABLE and SPP_PMTUD_DISABLE are mutually
  *                     exclusive. Enabling both will have undetermined
  *                     results.
  *
  *                     SPP_SACKDELAY_ENABLE - Setting this flag turns
  *                     on delayed sack. The time specified in spp_sackdelay
  *                     is used to specify the sack delay for this address. Note
  *                     that if spp_address is empty then all addresses will
  *                     enable delayed sack and take on the sack delay
  *                     value specified in spp_sackdelay.
  *                     SPP_SACKDELAY_DISABLE - Setting this flag turns
  *                     off delayed sack. If the spp_address field is blank then
  *                     delayed sack is disabled for the entire association. Note
  *                     also that this field is mutually exclusive to
  *                     SPP_SACKDELAY_ENABLE, setting both will have undefined
  *                     results.
  *
  *                     SPP_IPV6_FLOWLABEL:  Setting this flag enables the
  *                     setting of the IPV6 flow label value.  The value is
  *                     contained in the spp_ipv6_flowlabel field.
  *                     Upon retrieval, this flag will be set to indicate that
  *                     the spp_ipv6_flowlabel field has a valid value returned.
  *                     If a specific destination address is set (in the
  *                     spp_address field), then the value returned is that of
  *                     the address.  If just an association is specified (and
  *                     no address), then the association's default flow label
  *                     is returned.  If neither an association nor a destination
  *                     is specified, then the socket's default flow label is
  *                     returned.  For non-IPv6 sockets, this flag will be left
  *                     cleared.
  *
  *                     SPP_DSCP:  Setting this flag enables the setting of the
  *                     Differentiated Services Code Point (DSCP) value
  *                     associated with either the association or a specific
  *                     address.  The value is obtained in the spp_dscp field.
  *                     Upon retrieval, this flag will be set to indicate that
  *                     the spp_dscp field has a valid value returned.  If a
  *                     specific destination address is set when called (in the
  *                     spp_address field), then that specific destination
  *                     address's DSCP value is returned.  If just an association
  *                     is specified, then the association's default DSCP is
  *                     returned.  If neither an association nor a destination is
  *                     specified, then the socket's default DSCP is returned.
  *
  *   spp_ipv6_flowlabel
  *                   - This field is used in conjunction with the
  *                     SPP_IPV6_FLOWLABEL flag and contains the IPv6 flow label.
  *                     The 20 least significant bits are used for the flow
  *                     label.  This setting has precedence over any IPv6-layer
  *                     setting.
  *
  *   spp_dscp        - This field is used in conjunction with the SPP_DSCP flag
  *                     and contains the DSCP.  The 6 most significant bits are
  *                     used for the DSCP.  This setting has precedence over any
  *                     IPv4- or IPv6- layer setting.
  */
 static int sctp_apply_peer_addr_params(struct sctp_paddrparams *params,
                        struct sctp_transport   *trans,
                        struct sctp_association *asoc,
                        struct sctp_sock        *sp,
                        int                      hb_change,
                        int                      pmtud_change,
                        int                      sackdelay_change)
 {
     int error;
 
     if (params->spp_flags & SPP_HB_DEMAND && trans) {
         error = sctp_primitive_REQUESTHEARTBEAT(trans->asoc->base.net,
                             trans->asoc, trans);
         if (error)
             return error;
     }
 
     /* Note that unless the spp_flag is set to SPP_HB_ENABLE the value of
      * this field is ignored.  Note also that a value of zero indicates
      * the current setting should be left unchanged.
      */
     if (params->spp_flags & SPP_HB_ENABLE) {
 
         /* Re-zero the interval if the SPP_HB_TIME_IS_ZERO is
          * set.  This lets us use 0 value when this flag
          * is set.
          */
         if (params->spp_flags & SPP_HB_TIME_IS_ZERO)
             params->spp_hbinterval = 0;
 
         if (params->spp_hbinterval ||
             (params->spp_flags & SPP_HB_TIME_IS_ZERO)) {
             if (trans) {
                 trans->hbinterval =
                     msecs_to_jiffies(params->spp_hbinterval);
             } else if (asoc) {
                 asoc->hbinterval =
                     msecs_to_jiffies(params->spp_hbinterval);
             } else {
                 sp->hbinterval = params->spp_hbinterval;
             }
         }
     }
 
     if (hb_change) {
         if (trans) {
             trans->param_flags =
                 (trans->param_flags & ~SPP_HB) | hb_change;
         } else if (asoc) {
             asoc->param_flags =
                 (asoc->param_flags & ~SPP_HB) | hb_change;
         } else {
             sp->param_flags =
                 (sp->param_flags & ~SPP_HB) | hb_change;
         }
     }
 
     /* When Path MTU discovery is disabled the value specified here will
      * be the "fixed" path mtu (i.e. the value of the spp_flags field must
      * include the flag SPP_PMTUD_DISABLE for this field to have any
      * effect).
      */
     if ((params->spp_flags & SPP_PMTUD_DISABLE) && params->spp_pathmtu) {
         if (trans) {
             trans->pathmtu = params->spp_pathmtu;
             sctp_assoc_sync_pmtu(asoc);
         } else if (asoc) {
             sctp_assoc_set_pmtu(asoc, params->spp_pathmtu);
         } else {
             sp->pathmtu = params->spp_pathmtu;
         }
     }
 
     if (pmtud_change) {
         if (trans) {
             int update = (trans->param_flags & SPP_PMTUD_DISABLE) &&
                 (params->spp_flags & SPP_PMTUD_ENABLE);
             trans->param_flags =
                 (trans->param_flags & ~SPP_PMTUD) | pmtud_change;
             if (update) {
                 sctp_transport_pmtu(trans, sctp_opt2sk(sp));
                 sctp_assoc_sync_pmtu(asoc);
             }
             sctp_transport_pl_reset(trans);
         } else if (asoc) {
             asoc->param_flags =
                 (asoc->param_flags & ~SPP_PMTUD) | pmtud_change;
         } else {
             sp->param_flags =
                 (sp->param_flags & ~SPP_PMTUD) | pmtud_change;
         }
     }
 
     /* Note that unless the spp_flag is set to SPP_SACKDELAY_ENABLE the
      * value of this field is ignored.  Note also that a value of zero
      * indicates the current setting should be left unchanged.
      */
     if ((params->spp_flags & SPP_SACKDELAY_ENABLE) && params->spp_sackdelay) {
         if (trans) {
             trans->sackdelay =
                 msecs_to_jiffies(params->spp_sackdelay);
         } else if (asoc) {
             asoc->sackdelay =
                 msecs_to_jiffies(params->spp_sackdelay);
         } else {
             sp->sackdelay = params->spp_sackdelay;
         }
     }
 
     if (sackdelay_change) {
         if (trans) {
             trans->param_flags =
                 (trans->param_flags & ~SPP_SACKDELAY) |
                 sackdelay_change;
         } else if (asoc) {
             asoc->param_flags =
                 (asoc->param_flags & ~SPP_SACKDELAY) |
                 sackdelay_change;
         } else {
             sp->param_flags =
                 (sp->param_flags & ~SPP_SACKDELAY) |
                 sackdelay_change;
         }
     }
 
     /* Note that a value of zero indicates the current setting should be
        left unchanged.
      */
     if (params->spp_pathmaxrxt) {
         if (trans) {
             trans->pathmaxrxt = params->spp_pathmaxrxt;
         } else if (asoc) {
             asoc->pathmaxrxt = params->spp_pathmaxrxt;
         } else {
             sp->pathmaxrxt = params->spp_pathmaxrxt;
         }
     }
 
     if (params->spp_flags & SPP_IPV6_FLOWLABEL) {
         if (trans) {
             if (trans->ipaddr.sa.sa_family == AF_INET6) {
                 trans->flowlabel = params->spp_ipv6_flowlabel &
                            SCTP_FLOWLABEL_VAL_MASK;
                 trans->flowlabel |= SCTP_FLOWLABEL_SET_MASK;
             }
         } else if (asoc) {
             struct sctp_transport *t;
 
             list_for_each_entry(t, &asoc->peer.transport_addr_list,
                         transports) {
                 if (t->ipaddr.sa.sa_family != AF_INET6)
                     continue;
                 t->flowlabel = params->spp_ipv6_flowlabel &
                            SCTP_FLOWLABEL_VAL_MASK;
                 t->flowlabel |= SCTP_FLOWLABEL_SET_MASK;
             }
             asoc->flowlabel = params->spp_ipv6_flowlabel &
                       SCTP_FLOWLABEL_VAL_MASK;
             asoc->flowlabel |= SCTP_FLOWLABEL_SET_MASK;
         } else if (sctp_opt2sk(sp)->sk_family == AF_INET6) {
             sp->flowlabel = params->spp_ipv6_flowlabel &
                     SCTP_FLOWLABEL_VAL_MASK;
             sp->flowlabel |= SCTP_FLOWLABEL_SET_MASK;
         }
     }
 
     if (params->spp_flags & SPP_DSCP) {
         if (trans) {
             trans->dscp = params->spp_dscp & SCTP_DSCP_VAL_MASK;
             trans->dscp |= SCTP_DSCP_SET_MASK;
         } else if (asoc) {
             struct sctp_transport *t;
 
             list_for_each_entry(t, &asoc->peer.transport_addr_list,
                         transports) {
                 t->dscp = params->spp_dscp &
                       SCTP_DSCP_VAL_MASK;
                 t->dscp |= SCTP_DSCP_SET_MASK;
             }
             asoc->dscp = params->spp_dscp & SCTP_DSCP_VAL_MASK;
             asoc->dscp |= SCTP_DSCP_SET_MASK;
         } else {
             sp->dscp = params->spp_dscp & SCTP_DSCP_VAL_MASK;
             sp->dscp |= SCTP_DSCP_SET_MASK;
         }
     }
 
     return 0;
 }
 
 static int sctp_setsockopt_peer_addr_params(struct sock *sk,
                         struct sctp_paddrparams *params,
                         unsigned int optlen)
 {
     struct sctp_transport   *trans = NULL;
     struct sctp_association *asoc = NULL;
     struct sctp_sock        *sp = sctp_sk(sk);
     int error;
     int hb_change, pmtud_change, sackdelay_change;
 
     if (optlen == ALIGN(offsetof(struct sctp_paddrparams,
                         spp_ipv6_flowlabel), 4)) {
         if (params->spp_flags & (SPP_DSCP | SPP_IPV6_FLOWLABEL))
             return -EINVAL;
     } else if (optlen != sizeof(*params)) {
         return -EINVAL;
     }
 
     /* Validate flags and value parameters. */
     hb_change        = params->spp_flags & SPP_HB;
     pmtud_change     = params->spp_flags & SPP_PMTUD;
     sackdelay_change = params->spp_flags & SPP_SACKDELAY;
 
     if (hb_change        == SPP_HB ||
         pmtud_change     == SPP_PMTUD ||
         sackdelay_change == SPP_SACKDELAY ||
         params->spp_sackdelay > 500 ||
         (params->spp_pathmtu &&
          params->spp_pathmtu < SCTP_DEFAULT_MINSEGMENT))
         return -EINVAL;
 
     /* If an address other than INADDR_ANY is specified, and
      * no transport is found, then the request is invalid.
      */
     if (!sctp_is_any(sk, (union sctp_addr *)&params->spp_address)) {
         trans = sctp_addr_id2transport(sk, &params->spp_address,
                            params->spp_assoc_id);
         if (!trans)
             return -EINVAL;
     }
 
     /* Get association, if assoc_id != SCTP_FUTURE_ASSOC and the
      * socket is a one to many style socket, and an association
      * was not found, then the id was invalid.
      */
     asoc = sctp_id2assoc(sk, params->spp_assoc_id);
     if (!asoc && params->spp_assoc_id != SCTP_FUTURE_ASSOC &&
         sctp_style(sk, UDP))
         return -EINVAL;
 
     /* Heartbeat demand can only be sent on a transport or
      * association, but not a socket.
      */
     if (params->spp_flags & SPP_HB_DEMAND && !trans && !asoc)
         return -EINVAL;
 
     /* Process parameters. */
     error = sctp_apply_peer_addr_params(params, trans, asoc, sp,
                         hb_change, pmtud_change,
                         sackdelay_change);
 
     if (error)
         return error;
 
     /* If changes are for association, also apply parameters to each
      * transport.
      */
     if (!trans && asoc) {
         list_for_each_entry(trans, &asoc->peer.transport_addr_list,
                 transports) {
             sctp_apply_peer_addr_params(params, trans, asoc, sp,
                             hb_change, pmtud_change,
                             sackdelay_change);
         }
     }
 
     return 0;
 }
 
 static inline __u32 sctp_spp_sackdelay_enable(__u32 param_flags)
 {
     return (param_flags & ~SPP_SACKDELAY) | SPP_SACKDELAY_ENABLE;
 }
 
 static inline __u32 sctp_spp_sackdelay_disable(__u32 param_flags)
 {
     return (param_flags & ~SPP_SACKDELAY) | SPP_SACKDELAY_DISABLE;
 }
 
 static void sctp_apply_asoc_delayed_ack(struct sctp_sack_info *params,
                     struct sctp_association *asoc)
 {
     struct sctp_transport *trans;
 
     if (params->sack_delay) {
         asoc->sackdelay = msecs_to_jiffies(params->sack_delay);
         asoc->param_flags =
             sctp_spp_sackdelay_enable(asoc->param_flags);
     }
     if (params->sack_freq == 1) {
         asoc->param_flags =
             sctp_spp_sackdelay_disable(asoc->param_flags);
     } else if (params->sack_freq > 1) {
         asoc->sackfreq = params->sack_freq;
         asoc->param_flags =
             sctp_spp_sackdelay_enable(asoc->param_flags);
     }
 
     list_for_each_entry(trans, &asoc->peer.transport_addr_list,
                 transports) {
         if (params->sack_delay) {
             trans->sackdelay = msecs_to_jiffies(params->sack_delay);
             trans->param_flags =
                 sctp_spp_sackdelay_enable(trans->param_flags);
         }
         if (params->sack_freq == 1) {
             trans->param_flags =
                 sctp_spp_sackdelay_disable(trans->param_flags);
         } else if (params->sack_freq > 1) {
             trans->sackfreq = params->sack_freq;
             trans->param_flags =
                 sctp_spp_sackdelay_enable(trans->param_flags);
         }
     }
 }
 
 /*
  * 7.1.23.  Get or set delayed ack timer (SCTP_DELAYED_SACK)
  *
  * This option will effect the way delayed acks are performed.  This
  * option allows you to get or set the delayed ack time, in
  * milliseconds.  It also allows changing the delayed ack frequency.
  * Changing the frequency to 1 disables the delayed sack algorithm.  If
  * the assoc_id is 0, then this sets or gets the endpoints default
  * values.  If the assoc_id field is non-zero, then the set or get
  * effects the specified association for the one to many model (the
  * assoc_id field is ignored by the one to one model).  Note that if
  * sack_delay or sack_freq are 0 when setting this option, then the
  * current values will remain unchanged.
  *
  * struct sctp_sack_info {
  *     sctp_assoc_t            sack_assoc_id;
  *     uint32_t                sack_delay;
  *     uint32_t                sack_freq;
  * };
  *
  * sack_assoc_id -  This parameter, indicates which association the user
  *    is performing an action upon.  Note that if this field's value is
  *    zero then the endpoints default value is changed (effecting future
  *    associations only).
  *
  * sack_delay -  This parameter contains the number of milliseconds that
  *    the user is requesting the delayed ACK timer be set to.  Note that
  *    this value is defined in the standard to be between 200 and 500
  *    milliseconds.
  *
  * sack_freq -  This parameter contains the number of packets that must
  *    be received before a sack is sent without waiting for the delay
  *    timer to expire.  The default value for this is 2, setting this
  *    value to 1 will disable the delayed sack algorithm.
  */
 static int __sctp_setsockopt_delayed_ack(struct sock *sk,
                      struct sctp_sack_info *params)
 {
     struct sctp_sock *sp = sctp_sk(sk);
     struct sctp_association *asoc;
 
     /* Validate value parameter. */
     if (params->sack_delay > 500)
         return -EINVAL;
 
     /* Get association, if sack_assoc_id != SCTP_FUTURE_ASSOC and the
      * socket is a one to many style socket, and an association
      * was not found, then the id was invalid.
      */
     asoc = sctp_id2assoc(sk, params->sack_assoc_id);
     if (!asoc && params->sack_assoc_id > SCTP_ALL_ASSOC &&
         sctp_style(sk, UDP))
         return -EINVAL;
 
     if (asoc) {
         sctp_apply_asoc_delayed_ack(params, asoc);
 
         return 0;
     }
 
     if (sctp_style(sk, TCP))
         params->sack_assoc_id = SCTP_FUTURE_ASSOC;
 
     if (params->sack_assoc_id == SCTP_FUTURE_ASSOC ||
         params->sack_assoc_id == SCTP_ALL_ASSOC) {
         if (params->sack_delay) {
             sp->sackdelay = params->sack_delay;
             sp->param_flags =
                 sctp_spp_sackdelay_enable(sp->param_flags);
         }
         if (params->sack_freq == 1) {
             sp->param_flags =
                 sctp_spp_sackdelay_disable(sp->param_flags);
         } else if (params->sack_freq > 1) {
             sp->sackfreq = params->sack_freq;
             sp->param_flags =
                 sctp_spp_sackdelay_enable(sp->param_flags);
         }
     }
 
     if (params->sack_assoc_id == SCTP_CURRENT_ASSOC ||
         params->sack_assoc_id == SCTP_ALL_ASSOC)
         list_for_each_entry(asoc, &sp->ep->asocs, asocs)
             sctp_apply_asoc_delayed_ack(params, asoc);
 
     return 0;
 }
 
 static int sctp_setsockopt_delayed_ack(struct sock *sk,
                        struct sctp_sack_info *params,
                        unsigned int optlen)
 {
     if (optlen == sizeof(struct sctp_assoc_value)) {
         struct sctp_assoc_value *v = (struct sctp_assoc_value *)params;
         struct sctp_sack_info p;
 
         pr_warn_ratelimited(DEPRECATED
                     "%s (pid %d) "
                     "Use of struct sctp_assoc_value in delayed_ack socket option.\n"
                     "Use struct sctp_sack_info instead\n",
                     current->comm, task_pid_nr(current));
 
         p.sack_assoc_id = v->assoc_id;
         p.sack_delay = v->assoc_value;
         p.sack_freq = v->assoc_value ? 0 : 1;
         return __sctp_setsockopt_delayed_ack(sk, &p);
     }
 
     if (optlen != sizeof(struct sctp_sack_info))
         return -EINVAL;
     if (params->sack_delay == 0 && params->sack_freq == 0)
         return 0;
     return __sctp_setsockopt_delayed_ack(sk, params);
 }
 
 /* 7.1.3 Initialization Parameters (SCTP_INITMSG)
  *
  * Applications can specify protocol parameters for the default association
  * initialization.  The option name argument to setsockopt() and getsockopt()
  * is SCTP_INITMSG.
  *
  * Setting initialization parameters is effective only on an unconnected
  * socket (for UDP-style sockets only future associations are effected
  * by the change).  With TCP-style sockets, this option is inherited by
  * sockets derived from a listener socket.
  */
 static int sctp_setsockopt_initmsg(struct sock *sk, struct sctp_initmsg *sinit,
                    unsigned int optlen)
 {
     struct sctp_sock *sp = sctp_sk(sk);
 
     if (optlen != sizeof(struct sctp_initmsg))
         return -EINVAL;
 
     if (sinit->sinit_num_ostreams)
         sp->initmsg.sinit_num_ostreams = sinit->sinit_num_ostreams;
     if (sinit->sinit_max_instreams)
         sp->initmsg.sinit_max_instreams = sinit->sinit_max_instreams;
     if (sinit->sinit_max_attempts)
         sp->initmsg.sinit_max_attempts = sinit->sinit_max_attempts;
     if (sinit->sinit_max_init_timeo)
         sp->initmsg.sinit_max_init_timeo = sinit->sinit_max_init_timeo;
 
     return 0;
 }
 
 /*
  * 7.1.14 Set default send parameters (SCTP_DEFAULT_SEND_PARAM)
  *
  *   Applications that wish to use the sendto() system call may wish to
  *   specify a default set of parameters that would normally be supplied
  *   through the inclusion of ancillary data.  This socket option allows
  *   such an application to set the default sctp_sndrcvinfo structure.
  *   The application that wishes to use this socket option simply passes
  *   in to this call the sctp_sndrcvinfo structure defined in Section
  *   5.2.2) The input parameters accepted by this call include
  *   sinfo_stream, sinfo_flags, sinfo_ppid, sinfo_context,
  *   sinfo_timetolive.  The user must provide the sinfo_assoc_id field in
  *   to this call if the caller is using the UDP model.
  */
 static int sctp_setsockopt_default_send_param(struct sock *sk,
                           struct sctp_sndrcvinfo *info,
                           unsigned int optlen)
 {
     struct sctp_sock *sp = sctp_sk(sk);
     struct sctp_association *asoc;
 
     if (optlen != sizeof(*info))
         return -EINVAL;
     if (info->sinfo_flags &
         ~(SCTP_UNORDERED | SCTP_ADDR_OVER |
           SCTP_ABORT | SCTP_EOF))
         return -EINVAL;
 
     asoc = sctp_id2assoc(sk, info->sinfo_assoc_id);
     if (!asoc && info->sinfo_assoc_id > SCTP_ALL_ASSOC &&
         sctp_style(sk, UDP))
         return -EINVAL;
 
     if (asoc) {
         asoc->default_stream = info->sinfo_stream;
         asoc->default_flags = info->sinfo_flags;
         asoc->default_ppid = info->sinfo_ppid;
         asoc->default_context = info->sinfo_context;
         asoc->default_timetolive = info->sinfo_timetolive;
 
         return 0;
     }
 
     if (sctp_style(sk, TCP))
         info->sinfo_assoc_id = SCTP_FUTURE_ASSOC;
 
     if (info->sinfo_assoc_id == SCTP_FUTURE_ASSOC ||
         info->sinfo_assoc_id == SCTP_ALL_ASSOC) {
         sp->default_stream = info->sinfo_stream;
         sp->default_flags = info->sinfo_flags;
         sp->default_ppid = info->sinfo_ppid;
         sp->default_context = info->sinfo_context;
         sp->default_timetolive = info->sinfo_timetolive;
     }
 
     if (info->sinfo_assoc_id == SCTP_CURRENT_ASSOC ||
         info->sinfo_assoc_id == SCTP_ALL_ASSOC) {
         list_for_each_entry(asoc, &sp->ep->asocs, asocs) {
             asoc->default_stream = info->sinfo_stream;
             asoc->default_flags = info->sinfo_flags;
             asoc->default_ppid = info->sinfo_ppid;
             asoc->default_context = info->sinfo_context;
             asoc->default_timetolive = info->sinfo_timetolive;
         }
     }
 
     return 0;
 }
 
 /* RFC6458, Section 8.1.31. Set/get Default Send Parameters
  * (SCTP_DEFAULT_SNDINFO)
  */
 static int sctp_setsockopt_default_sndinfo(struct sock *sk,
                        struct sctp_sndinfo *info,
                        unsigned int optlen)
 {
     struct sctp_sock *sp = sctp_sk(sk);
     struct sctp_association *asoc;
 
     if (optlen != sizeof(*info))
         return -EINVAL;
     if (info->snd_flags &
         ~(SCTP_UNORDERED | SCTP_ADDR_OVER |
           SCTP_ABORT | SCTP_EOF))
         return -EINVAL;
 
     asoc = sctp_id2assoc(sk, info->snd_assoc_id);
     if (!asoc && info->snd_assoc_id > SCTP_ALL_ASSOC &&
         sctp_style(sk, UDP))
         return -EINVAL;
 
     if (asoc) {
         asoc->default_stream = info->snd_sid;
         asoc->default_flags = info->snd_flags;
         asoc->default_ppid = info->snd_ppid;
         asoc->default_context = info->snd_context;
 
         return 0;
     }
 
     if (sctp_style(sk, TCP))
         info->snd_assoc_id = SCTP_FUTURE_ASSOC;
 
     if (info->snd_assoc_id == SCTP_FUTURE_ASSOC ||
         info->snd_assoc_id == SCTP_ALL_ASSOC) {
         sp->default_stream = info->snd_sid;
         sp->default_flags = info->snd_flags;
         sp->default_ppid = info->snd_ppid;
         sp->default_context = info->snd_context;
     }
 
     if (info->snd_assoc_id == SCTP_CURRENT_ASSOC ||
         info->snd_assoc_id == SCTP_ALL_ASSOC) {
         list_for_each_entry(asoc, &sp->ep->asocs, asocs) {
             asoc->default_stream = info->snd_sid;
             asoc->default_flags = info->snd_flags;
             asoc->default_ppid = info->snd_ppid;
             asoc->default_context = info->snd_context;
         }
     }
 
     return 0;
 }
 
 /* 7.1.10 Set Primary Address (SCTP_PRIMARY_ADDR)
  *
  * Requests that the local SCTP stack use the enclosed peer address as
  * the association primary.  The enclosed address must be one of the
  * association peer's addresses.
  */
 static int sctp_setsockopt_primary_addr(struct sock *sk, struct sctp_prim *prim,
                     unsigned int optlen)
 {
     struct sctp_transport *trans;
     struct sctp_af *af;
     int err;
 
     if (optlen != sizeof(struct sctp_prim))
         return -EINVAL;
 
     /* Allow security module to validate address but need address len. */
     af = sctp_get_af_specific(prim->ssp_addr.ss_family);
     if (!af)
         return -EINVAL;
 
     err = security_sctp_bind_connect(sk, SCTP_PRIMARY_ADDR,
                      (struct sockaddr *)&prim->ssp_addr,
                      af->sockaddr_len);
     if (err)
         return err;
 
     trans = sctp_addr_id2transport(sk, &prim->ssp_addr, prim->ssp_assoc_id);
     if (!trans)
         return -EINVAL;
 
     sctp_assoc_set_primary(trans->asoc, trans);
 
     return 0;
 }
 
 /*
  * 7.1.5 SCTP_NODELAY
  *
  * Turn on/off any Nagle-like algorithm.  This means that packets are
  * generally sent as soon as possible and no unnecessary delays are
  * introduced, at the cost of more packets in the network.  Expects an
  *  integer boolean flag.
  */
 static int sctp_setsockopt_nodelay(struct sock *sk, int *val,
                    unsigned int optlen)
 {
     if (optlen < sizeof(int))
         return -EINVAL;
     sctp_sk(sk)->nodelay = (*val == 0) ? 0 : 1;
     return 0;
 }
 
 /*
  *
  * 7.1.1 SCTP_RTOINFO
  *
  * The protocol parameters used to initialize and bound retransmission
  * timeout (RTO) are tunable. sctp_rtoinfo structure is used to access
  * and modify these parameters.
  * All parameters are time values, in milliseconds.  A value of 0, when
  * modifying the parameters, indicates that the current value should not
  * be changed.
  *
  */
 static int sctp_setsockopt_rtoinfo(struct sock *sk,
                    struct sctp_rtoinfo *rtoinfo,
                    unsigned int optlen)
 {
     struct sctp_association *asoc;
     unsigned long rto_min, rto_max;
     struct sctp_sock *sp = sctp_sk(sk);
 
     if (optlen != sizeof (struct sctp_rtoinfo))
         return -EINVAL;
 
     asoc = sctp_id2assoc(sk, rtoinfo->srto_assoc_id);
 
     /* Set the values to the specific association */
     if (!asoc && rtoinfo->srto_assoc_id != SCTP_FUTURE_ASSOC &&
         sctp_style(sk, UDP))
         return -EINVAL;
 
     rto_max = rtoinfo->srto_max;
     rto_min = rtoinfo->srto_min;
 
     if (rto_max)
         rto_max = asoc ? msecs_to_jiffies(rto_max) : rto_max;
     else
         rto_max = asoc ? asoc->rto_max : sp->rtoinfo.srto_max;
 
     if (rto_min)
         rto_min = asoc ? msecs_to_jiffies(rto_min) : rto_min;
     else
         rto_min = asoc ? asoc->rto_min : sp->rtoinfo.srto_min;
 
     if (rto_min > rto_max)
         return -EINVAL;
 
     if (asoc) {
         if (rtoinfo->srto_initial != 0)
             asoc->rto_initial =
                 msecs_to_jiffies(rtoinfo->srto_initial);
         asoc->rto_max = rto_max;
         asoc->rto_min = rto_min;
     } else {
         /* If there is no association or the association-id = 0
          * set the values to the endpoint.
          */
         if (rtoinfo->srto_initial != 0)
             sp->rtoinfo.srto_initial = rtoinfo->srto_initial;
         sp->rtoinfo.srto_max = rto_max;
         sp->rtoinfo.srto_min = rto_min;
     }
 
     return 0;
 }
 
 /*
  *
  * 7.1.2 SCTP_ASSOCINFO
  *
  * This option is used to tune the maximum retransmission attempts
  * of the association.
  * Returns an error if the new association retransmission value is
  * greater than the sum of the retransmission value  of the peer.
  * See [SCTP] for more information.
  *
  */
 static int sctp_setsockopt_associnfo(struct sock *sk,
                      struct sctp_assocparams *assocparams,
                      unsigned int optlen)
 {
 
     struct sctp_association *asoc;
 
     if (optlen != sizeof(struct sctp_assocparams))
         return -EINVAL;
 
     asoc = sctp_id2assoc(sk, assocparams->sasoc_assoc_id);
 
     if (!asoc && assocparams->sasoc_assoc_id != SCTP_FUTURE_ASSOC &&
         sctp_style(sk, UDP))
         return -EINVAL;
 
     /* Set the values to the specific association */
     if (asoc) {
         if (assocparams->sasoc_asocmaxrxt != 0) {
             __u32 path_sum = 0;
             int   paths = 0;
             struct sctp_transport *peer_addr;
 
             list_for_each_entry(peer_addr, &asoc->peer.transport_addr_list,
                     transports) {
                 path_sum += peer_addr->pathmaxrxt;
                 paths++;
             }
 
             /* Only validate asocmaxrxt if we have more than
              * one path/transport.  We do this because path
              * retransmissions are only counted when we have more
              * then one path.
              */
             if (paths > 1 &&
                 assocparams->sasoc_asocmaxrxt > path_sum)
                 return -EINVAL;
 
             asoc->max_retrans = assocparams->sasoc_asocmaxrxt;
         }
 
         if (assocparams->sasoc_cookie_life != 0)
             asoc->cookie_life =
                 ms_to_ktime(assocparams->sasoc_cookie_life);
     } else {
         /* Set the values to the endpoint */
         struct sctp_sock *sp = sctp_sk(sk);
 
         if (assocparams->sasoc_asocmaxrxt != 0)
             sp->assocparams.sasoc_asocmaxrxt =
                         assocparams->sasoc_asocmaxrxt;
         if (assocparams->sasoc_cookie_life != 0)
             sp->assocparams.sasoc_cookie_life =
                         assocparams->sasoc_cookie_life;
     }
     return 0;
 }
 
 /*
  * 7.1.16 Set/clear IPv4 mapped addresses (SCTP_I_WANT_MAPPED_V4_ADDR)
  *
  * This socket option is a boolean flag which turns on or off mapped V4
  * addresses.  If this option is turned on and the socket is type
  * PF_INET6, then IPv4 addresses will be mapped to V6 representation.
  * If this option is turned off, then no mapping will be done of V4
  * addresses and a user will receive both PF_INET6 and PF_INET type
  * addresses on the socket.
  */
 static int sctp_setsockopt_mappedv4(struct sock *sk, int *val,
                     unsigned int optlen)
 {
     struct sctp_sock *sp = sctp_sk(sk);
 
     if (optlen < sizeof(int))
         return -EINVAL;
     if (*val)
         sp->v4mapped = 1;
     else
         sp->v4mapped = 0;
 
     return 0;
 }
 
 /*
  * 8.1.16.  Get or Set the Maximum Fragmentation Size (SCTP_MAXSEG)
  * This option will get or set the maximum size to put in any outgoing
  * SCTP DATA chunk.  If a message is larger than this size it will be
  * fragmented by SCTP into the specified size.  Note that the underlying
  * SCTP implementation may fragment into smaller sized chunks when the
  * PMTU of the underlying association is smaller than the value set by
  * the user.  The default value for this option is '0' which indicates
  * the user is NOT limiting fragmentation and only the PMTU will effect
  * SCTP's choice of DATA chunk size.  Note also that values set larger
  * than the maximum size of an IP datagram will effectively let SCTP
  * control fragmentation (i.e. the same as setting this option to 0).
  *
  * The following structure is used to access and modify this parameter:
  *
  * struct sctp_assoc_value {
  *   sctp_assoc_t assoc_id;
  *   uint32_t assoc_value;
  * };
  *
  * assoc_id:  This parameter is ignored for one-to-one style sockets.
  *    For one-to-many style sockets this parameter indicates which
  *    association the user is performing an action upon.  Note that if
  *    this field's value is zero then the endpoints default value is
  *    changed (effecting future associations only).
  * assoc_value:  This parameter specifies the maximum size in bytes.
  */
 static int sctp_setsockopt_maxseg(struct sock *sk,
                   struct sctp_assoc_value *params,
                   unsigned int optlen)
 {
     struct sctp_sock *sp = sctp_sk(sk);
     struct sctp_association *asoc;
     sctp_assoc_t assoc_id;
     int val;
 
     if (optlen == sizeof(int)) {
         pr_warn_ratelimited(DEPRECATED
                     "%s (pid %d) "
                     "Use of int in maxseg socket option.\n"
                     "Use struct sctp_assoc_value instead\n",
                     current->comm, task_pid_nr(current));
         assoc_id = SCTP_FUTURE_ASSOC;
         val = *(int *)params;
     } else if (optlen == sizeof(struct sctp_assoc_value)) {
         assoc_id = params->assoc_id;
         val = params->assoc_value;
     } else {
         return -EINVAL;
     }
 
     asoc = sctp_id2assoc(sk, assoc_id);
     if (!asoc && assoc_id != SCTP_FUTURE_ASSOC &&
         sctp_style(sk, UDP))
         return -EINVAL;
 
     if (val) {
         int min_len, max_len;
         __u16 datasize = asoc ? sctp_datachk_len(&asoc->stream) :
                  sizeof(struct sctp_data_chunk);
 
         min_len = sctp_min_frag_point(sp, datasize);
         max_len = SCTP_MAX_CHUNK_LEN - datasize;
 
         if (val < min_len || val > max_len)
             return -EINVAL;
     }
 
     if (asoc) {
         asoc->user_frag = val;
         sctp_assoc_update_frag_point(asoc);
     } else {
         sp->user_frag = val;
     }
 
     return 0;
 }
 
 
 /*
  *  7.1.9 Set Peer Primary Address (SCTP_SET_PEER_PRIMARY_ADDR)
  *
  *   Requests that the peer mark the enclosed address as the association
  *   primary. The enclosed address must be one of the association's
  *   locally bound addresses. The following structure is used to make a
  *   set primary request:
  */
 static int sctp_setsockopt_peer_primary_addr(struct sock *sk,
                          struct sctp_setpeerprim *prim,
                          unsigned int optlen)
 {
     struct sctp_sock    *sp;
     struct sctp_association *asoc = NULL;
     struct sctp_chunk   *chunk;
     struct sctp_af      *af;
     int             err;
 
     sp = sctp_sk(sk);
 
     if (!sp->ep->asconf_enable)
         return -EPERM;
 
     if (optlen != sizeof(struct sctp_setpeerprim))
         return -EINVAL;
 
     asoc = sctp_id2assoc(sk, prim->sspp_assoc_id);
     if (!asoc)
         return -EINVAL;
 
     if (!asoc->peer.asconf_capable)
         return -EPERM;
 
     if (asoc->peer.addip_disabled_mask & SCTP_PARAM_SET_PRIMARY)
         return -EPERM;
 
     if (!sctp_state(asoc, ESTABLISHED))
         return -ENOTCONN;
 
     af = sctp_get_af_specific(prim->sspp_addr.ss_family);
     if (!af)
         return -EINVAL;
 
     if (!af->addr_valid((union sctp_addr *)&prim->sspp_addr, sp, NULL))
         return -EADDRNOTAVAIL;
 
     if (!sctp_assoc_lookup_laddr(asoc, (union sctp_addr *)&prim->sspp_addr))
         return -EADDRNOTAVAIL;
 
     /* Allow security module to validate address. */
     err = security_sctp_bind_connect(sk, SCTP_SET_PEER_PRIMARY_ADDR,
                      (struct sockaddr *)&prim->sspp_addr,
                      af->sockaddr_len);
     if (err)
         return err;
 
     /* Create an ASCONF chunk with SET_PRIMARY parameter    */
     chunk = sctp_make_asconf_set_prim(asoc,
                       (union sctp_addr *)&prim->sspp_addr);
     if (!chunk)
         return -ENOMEM;
 
     err = sctp_send_asconf(asoc, chunk);
 
     pr_debug("%s: we set peer primary addr primitively\n", __func__);
 
     return err;
 }
 
 static int sctp_setsockopt_adaptation_layer(struct sock *sk,
                         struct sctp_setadaptation *adapt,
                         unsigned int optlen)
 {
     if (optlen != sizeof(struct sctp_setadaptation))
         return -EINVAL;
 
     sctp_sk(sk)->adaptation_ind = adapt->ssb_adaptation_ind;
 
     return 0;
 }
 
 /*
  * 7.1.29.  Set or Get the default context (SCTP_CONTEXT)
  *
  * The context field in the sctp_sndrcvinfo structure is normally only
  * used when a failed message is retrieved holding the value that was
  * sent down on the actual send call.  This option allows the setting of
  * a default context on an association basis that will be received on
  * reading messages from the peer.  This is especially helpful in the
  * one-2-many model for an application to keep some reference to an
  * internal state machine that is processing messages on the
  * association.  Note that the setting of this value only effects
  * received messages from the peer and does not effect the value that is
  * saved with outbound messages.
  */
 static int sctp_setsockopt_context(struct sock *sk,
                    struct sctp_assoc_value *params,
                    unsigned int optlen)
 {
     struct sctp_sock *sp = sctp_sk(sk);
     struct sctp_association *asoc;
 
     if (optlen != sizeof(struct sctp_assoc_value))
         return -EINVAL;
 
     asoc = sctp_id2assoc(sk, params->assoc_id);
     if (!asoc && params->assoc_id > SCTP_ALL_ASSOC &&
         sctp_style(sk, UDP))
         return -EINVAL;
 
     if (asoc) {
         asoc->default_rcv_context = params->assoc_value;
 
         return 0;
     }
 
     if (sctp_style(sk, TCP))
         params->assoc_id = SCTP_FUTURE_ASSOC;
 
     if (params->assoc_id == SCTP_FUTURE_ASSOC ||
         params->assoc_id == SCTP_ALL_ASSOC)
         sp->default_rcv_context = params->assoc_value;
 
     if (params->assoc_id == SCTP_CURRENT_ASSOC ||
         params->assoc_id == SCTP_ALL_ASSOC)
         list_for_each_entry(asoc, &sp->ep->asocs, asocs)
             asoc->default_rcv_context = params->assoc_value;
 
     return 0;
 }
 
 /*
  * 7.1.24.  Get or set fragmented interleave (SCTP_FRAGMENT_INTERLEAVE)
  *
  * This options will at a minimum specify if the implementation is doing
  * fragmented interleave.  Fragmented interleave, for a one to many
  * socket, is when subsequent calls to receive a message may return
  * parts of messages from different associations.  Some implementations
  * may allow you to turn this value on or off.  If so, when turned off,
  * no fragment interleave will occur (which will cause a head of line
  * blocking amongst multiple associations sharing the same one to many
  * socket).  When this option is turned on, then each receive call may
  * come from a different association (thus the user must receive data
  * with the extended calls (e.g. sctp_recvmsg) to keep track of which
  * association each receive belongs to.
  *
  * This option takes a boolean value.  A non-zero value indicates that
  * fragmented interleave is on.  A value of zero indicates that
  * fragmented interleave is off.
  *
  * Note that it is important that an implementation that allows this
  * option to be turned on, have it off by default.  Otherwise an unaware
  * application using the one to many model may become confused and act
  * incorrectly.
  */
 static int sctp_setsockopt_fragment_interleave(struct sock *sk, int *val,
                            unsigned int optlen)
 {
     if (optlen != sizeof(int))
         return -EINVAL;
 
     sctp_sk(sk)->frag_interleave = !!*val;
 
     if (!sctp_sk(sk)->frag_interleave)
         sctp_sk(sk)->ep->intl_enable = 0;
 
     return 0;
 }
 
 /*
  * 8.1.21.  Set or Get the SCTP Partial Delivery Point
  *       (SCTP_PARTIAL_DELIVERY_POINT)
  *
  * This option will set or get the SCTP partial delivery point.  This
  * point is the size of a message where the partial delivery API will be
  * invoked to help free up rwnd space for the peer.  Setting this to a
  * lower value will cause partial deliveries to happen more often.  The
  * calls argument is an integer that sets or gets the partial delivery
  * point.  Note also that the call will fail if the user attempts to set
  * this value larger than the socket receive buffer size.
  *
  * Note that any single message having a length smaller than or equal to
  * the SCTP partial delivery point will be delivered in one single read
  * call as long as the user provided buffer is large enough to hold the
  * message.
  */
 static int sctp_setsockopt_partial_delivery_point(struct sock *sk, u32 *val,
                           unsigned int optlen)
 {
     if (optlen != sizeof(u32))
         return -EINVAL;
 
     /* Note: We double the receive buffer from what the user sets
      * it to be, also initial rwnd is based on rcvbuf/2.
      */
     if (*val > (sk->sk_rcvbuf >> 1))
         return -EINVAL;
 
     sctp_sk(sk)->pd_point = *val;
 
     return 0; /* is this the right error code? */
 }
 
 /*
  * 7.1.28.  Set or Get the maximum burst (SCTP_MAX_BURST)
  *
  * This option will allow a user to change the maximum burst of packets
  * that can be emitted by this association.  Note that the default value
  * is 4, and some implementations may restrict this setting so that it
  * can only be lowered.
  *
  * NOTE: This text doesn't seem right.  Do this on a socket basis with
  * future associations inheriting the socket value.
  */
 static int sctp_setsockopt_maxburst(struct sock *sk,
                     struct sctp_assoc_value *params,
                     unsigned int optlen)
 {
     struct sctp_sock *sp = sctp_sk(sk);
     struct sctp_association *asoc;
     sctp_assoc_t assoc_id;
     u32 assoc_value;
 
     if (optlen == sizeof(int)) {
         pr_warn_ratelimited(DEPRECATED
                     "%s (pid %d) "
                     "Use of int in max_burst socket option deprecated.\n"
                     "Use struct sctp_assoc_value instead\n",
                     current->comm, task_pid_nr(current));
         assoc_id = SCTP_FUTURE_ASSOC;
         assoc_value = *((int *)params);
     } else if (optlen == sizeof(struct sctp_assoc_value)) {
         assoc_id = params->assoc_id;
         assoc_value = params->assoc_value;
     } else
         return -EINVAL;
 
     asoc = sctp_id2assoc(sk, assoc_id);
     if (!asoc && assoc_id > SCTP_ALL_ASSOC && sctp_style(sk, UDP))
         return -EINVAL;
 
     if (asoc) {
         asoc->max_burst = assoc_value;
 
         return 0;
     }
 
     if (sctp_style(sk, TCP))
         assoc_id = SCTP_FUTURE_ASSOC;
 
     if (assoc_id == SCTP_FUTURE_ASSOC || assoc_id == SCTP_ALL_ASSOC)
         sp->max_burst = assoc_value;
 
     if (assoc_id == SCTP_CURRENT_ASSOC || assoc_id == SCTP_ALL_ASSOC)
         list_for_each_entry(asoc, &sp->ep->asocs, asocs)
             asoc->max_burst = assoc_value;
 
     return 0;
 }
 
 /*
  * 7.1.18.  Add a chunk that must be authenticated (SCTP_AUTH_CHUNK)
  *
  * This set option adds a chunk type that the user is requesting to be
  * received only in an authenticated way.  Changes to the list of chunks
  * will only effect future associations on the socket.
  */
 static int sctp_setsockopt_auth_chunk(struct sock *sk,
                       struct sctp_authchunk *val,
                       unsigned int optlen)
 {
     struct sctp_endpoint *ep = sctp_sk(sk)->ep;
 
     if (!ep->auth_enable)
         return -EACCES;
 
     if (optlen != sizeof(struct sctp_authchunk))
         return -EINVAL;
 
     switch (val->sauth_chunk) {
     case SCTP_CID_INIT:
     case SCTP_CID_INIT_ACK:
     case SCTP_CID_SHUTDOWN_COMPLETE:
     case SCTP_CID_AUTH:
         return -EINVAL;
     }
 
     /* add this chunk id to the endpoint */
     return sctp_auth_ep_add_chunkid(ep, val->sauth_chunk);
 }
 
 /*
  * 7.1.19.  Get or set the list of supported HMAC Identifiers (SCTP_HMAC_IDENT)
  *
  * This option gets or sets the list of HMAC algorithms that the local
  * endpoint requires the peer to use.
  */
 static int sctp_setsockopt_hmac_ident(struct sock *sk,
                       struct sctp_hmacalgo *hmacs,
                       unsigned int optlen)
 {
     struct sctp_endpoint *ep = sctp_sk(sk)->ep;
     u32 idents;
 
     if (!ep->auth_enable)
         return -EACCES;
 
     if (optlen < sizeof(struct sctp_hmacalgo))
         return -EINVAL;
     optlen = min_t(unsigned int, optlen, sizeof(struct sctp_hmacalgo) +
                          SCTP_AUTH_NUM_HMACS * sizeof(u16));
 
     idents = hmacs->shmac_num_idents;
     if (idents == 0 || idents > SCTP_AUTH_NUM_HMACS ||
         (idents * sizeof(u16)) > (optlen - sizeof(struct sctp_hmacalgo)))
         return -EINVAL;
 
     return sctp_auth_ep_set_hmacs(ep, hmacs);
 }
 
 /*
  * 7.1.20.  Set a shared key (SCTP_AUTH_KEY)
  *
  * This option will set a shared secret key which is used to build an
  * association shared key.
  */
 static int sctp_setsockopt_auth_key(struct sock *sk,
                     struct sctp_authkey *authkey,
                     unsigned int optlen)
 {
     struct sctp_endpoint *ep = sctp_sk(sk)->ep;
     struct sctp_association *asoc;
     int ret = -EINVAL;
 
     if (optlen <= sizeof(struct sctp_authkey))
         return -EINVAL;
     /* authkey->sca_keylength is u16, so optlen can't be bigger than
      * this.
      */
     optlen = min_t(unsigned int, optlen, USHRT_MAX + sizeof(*authkey));
 
     if (authkey->sca_keylength > optlen - sizeof(*authkey))
         goto out;
 
     asoc = sctp_id2assoc(sk, authkey->sca_assoc_id);
     if (!asoc && authkey->sca_assoc_id > SCTP_ALL_ASSOC &&
         sctp_style(sk, UDP))
         goto out;
 
     if (asoc) {
         ret = sctp_auth_set_key(ep, asoc, authkey);
         goto out;
     }
 
     if (sctp_style(sk, TCP))
         authkey->sca_assoc_id = SCTP_FUTURE_ASSOC;
 
     if (authkey->sca_assoc_id == SCTP_FUTURE_ASSOC ||
         authkey->sca_assoc_id == SCTP_ALL_ASSOC) {
         ret = sctp_auth_set_key(ep, asoc, authkey);
         if (ret)
             goto out;
     }
 
     ret = 0;
 
     if (authkey->sca_assoc_id == SCTP_CURRENT_ASSOC ||
         authkey->sca_assoc_id == SCTP_ALL_ASSOC) {
         list_for_each_entry(asoc, &ep->asocs, asocs) {
             int res = sctp_auth_set_key(ep, asoc, authkey);
 
             if (res && !ret)
                 ret = res;
         }
     }
 
 out:
     memzero_explicit(authkey, optlen);
     return ret;
 }
 
 /*
  * 7.1.21.  Get or set the active shared key (SCTP_AUTH_ACTIVE_KEY)
  *
  * This option will get or set the active shared key to be used to build
  * the association shared key.
  */
 static int sctp_setsockopt_active_key(struct sock *sk,
                       struct sctp_authkeyid *val,
                       unsigned int optlen)
 {
     struct sctp_endpoint *ep = sctp_sk(sk)->ep;
     struct sctp_association *asoc;
     int ret = 0;
 
     if (optlen != sizeof(struct sctp_authkeyid))
         return -EINVAL;
 
     asoc = sctp_id2assoc(sk, val->scact_assoc_id);
     if (!asoc && val->scact_assoc_id > SCTP_ALL_ASSOC &&
         sctp_style(sk, UDP))
         return -EINVAL;
 
     if (asoc)
         return sctp_auth_set_active_key(ep, asoc, val->scact_keynumber);
 
     if (sctp_style(sk, TCP))
         val->scact_assoc_id = SCTP_FUTURE_ASSOC;
 
     if (val->scact_assoc_id == SCTP_FUTURE_ASSOC ||
         val->scact_assoc_id == SCTP_ALL_ASSOC) {
         ret = sctp_auth_set_active_key(ep, asoc, val->scact_keynumber);
         if (ret)
             return ret;
     }
 
     if (val->scact_assoc_id == SCTP_CURRENT_ASSOC ||
         val->scact_assoc_id == SCTP_ALL_ASSOC) {
         list_for_each_entry(asoc, &ep->asocs, asocs) {
             int res = sctp_auth_set_active_key(ep, asoc,
                                val->scact_keynumber);
 
             if (res && !ret)
                 ret = res;
         }
     }
 
     return ret;
 }
 
 /*
  * 7.1.22.  Delete a shared key (SCTP_AUTH_DELETE_KEY)
  *
  * This set option will delete a shared secret key from use.
  */
 static int sctp_setsockopt_del_key(struct sock *sk,
                    struct sctp_authkeyid *val,
                    unsigned int optlen)
 {
     struct sctp_endpoint *ep = sctp_sk(sk)->ep;
     struct sctp_association *asoc;
     int ret = 0;
 
     if (optlen != sizeof(struct sctp_authkeyid))
         return -EINVAL;
 
     asoc = sctp_id2assoc(sk, val->scact_assoc_id);
     if (!asoc && val->scact_assoc_id > SCTP_ALL_ASSOC &&
         sctp_style(sk, UDP))
         return -EINVAL;
 
     if (asoc)
         return sctp_auth_del_key_id(ep, asoc, val->scact_keynumber);
 
     if (sctp_style(sk, TCP))
         val->scact_assoc_id = SCTP_FUTURE_ASSOC;
 
     if (val->scact_assoc_id == SCTP_FUTURE_ASSOC ||
         val->scact_assoc_id == SCTP_ALL_ASSOC) {
         ret = sctp_auth_del_key_id(ep, asoc, val->scact_keynumber);
         if (ret)
             return ret;
     }
 
     if (val->scact_assoc_id == SCTP_CURRENT_ASSOC ||
         val->scact_assoc_id == SCTP_ALL_ASSOC) {
         list_for_each_entry(asoc, &ep->asocs, asocs) {
             int res = sctp_auth_del_key_id(ep, asoc,
                                val->scact_keynumber);
 
             if (res && !ret)
                 ret = res;
         }
     }
 
     return ret;
 }
 
 /*
  * 8.3.4  Deactivate a Shared Key (SCTP_AUTH_DEACTIVATE_KEY)
  *
  * This set option will deactivate a shared secret key.
  */
 static int sctp_setsockopt_deactivate_key(struct sock *sk,
                       struct sctp_authkeyid *val,
                       unsigned int optlen)
 {
     struct sctp_endpoint *ep = sctp_sk(sk)->ep;
     struct sctp_association *asoc;
     int ret = 0;
 
     if (optlen != sizeof(struct sctp_authkeyid))
         return -EINVAL;
 
     asoc = sctp_id2assoc(sk, val->scact_assoc_id);
     if (!asoc && val->scact_assoc_id > SCTP_ALL_ASSOC &&
         sctp_style(sk, UDP))
         return -EINVAL;
 
     if (asoc)
         return sctp_auth_deact_key_id(ep, asoc, val->scact_keynumber);
 
     if (sctp_style(sk, TCP))
         val->scact_assoc_id = SCTP_FUTURE_ASSOC;
 
     if (val->scact_assoc_id == SCTP_FUTURE_ASSOC ||
         val->scact_assoc_id == SCTP_ALL_ASSOC) {
         ret = sctp_auth_deact_key_id(ep, asoc, val->scact_keynumber);
         if (ret)
             return ret;
     }
 
     if (val->scact_assoc_id == SCTP_CURRENT_ASSOC ||
         val->scact_assoc_id == SCTP_ALL_ASSOC) {
         list_for_each_entry(asoc, &ep->asocs, asocs) {
             int res = sctp_auth_deact_key_id(ep, asoc,
                              val->scact_keynumber);
 
             if (res && !ret)
                 ret = res;
         }
     }
 
     return ret;
 }
 
 /*
  * 8.1.23 SCTP_AUTO_ASCONF
  *
  * This option will enable or disable the use of the automatic generation of
  * ASCONF chunks to add and delete addresses to an existing association.  Note
  * that this option has two caveats namely: a) it only affects sockets that
  * are bound to all addresses available to the SCTP stack, and b) the system
  * administrator may have an overriding control that turns the ASCONF feature
  * off no matter what setting the socket option may have.
  * This option expects an integer boolean flag, where a non-zero value turns on
  * the option, and a zero value turns off the option.
  * Note. In this implementation, socket operation overrides default parameter
  * being set by sysctl as well as FreeBSD implementation
  */
 static int sctp_setsockopt_auto_asconf(struct sock *sk, int *val,
                     unsigned int optlen)
 {
     struct sctp_sock *sp = sctp_sk(sk);
 
     if (optlen < sizeof(int))
         return -EINVAL;
     if (!sctp_is_ep_boundall(sk) && *val)
         return -EINVAL;
     if ((*val && sp->do_auto_asconf) || (!*val && !sp->do_auto_asconf))
         return 0;
 
     spin_lock_bh(&sock_net(sk)->sctp.addr_wq_lock);
     if (*val == 0 && sp->do_auto_asconf) {
         list_del(&sp->auto_asconf_list);
         sp->do_auto_asconf = 0;
     } else if (*val && !sp->do_auto_asconf) {
         list_add_tail(&sp->auto_asconf_list,
             &sock_net(sk)->sctp.auto_asconf_splist);
         sp->do_auto_asconf = 1;
     }
     spin_unlock_bh(&sock_net(sk)->sctp.addr_wq_lock);
     return 0;
 }
 
 /*
  * SCTP_PEER_ADDR_THLDS
  *
  * This option allows us to alter the partially failed threshold for one or all
  * transports in an association.  See Section 6.1 of:
  * http://www.ietf.org/id/draft-nishida-tsvwg-sctp-failover-05.txt
  */
 static int sctp_setsockopt_paddr_thresholds(struct sock *sk,
                         struct sctp_paddrthlds_v2 *val,
                         unsigned int optlen, bool v2)
 {
     struct sctp_transport *trans;
     struct sctp_association *asoc;
     int len;
 
     len = v2 ? sizeof(*val) : sizeof(struct sctp_paddrthlds);
     if (optlen < len)
         return -EINVAL;
 
     if (v2 && val->spt_pathpfthld > val->spt_pathcpthld)
         return -EINVAL;
 
     if (!sctp_is_any(sk, (const union sctp_addr *)&val->spt_address)) {
         trans = sctp_addr_id2transport(sk, &val->spt_address,
                            val->spt_assoc_id);
         if (!trans)
             return -ENOENT;
 
         if (val->spt_pathmaxrxt)
             trans->pathmaxrxt = val->spt_pathmaxrxt;
         if (v2)
             trans->ps_retrans = val->spt_pathcpthld;
         trans->pf_retrans = val->spt_pathpfthld;
 
         return 0;
     }
 
     asoc = sctp_id2assoc(sk, val->spt_assoc_id);
     if (!asoc && val->spt_assoc_id != SCTP_FUTURE_ASSOC &&
         sctp_style(sk, UDP))
         return -EINVAL;
 
     if (asoc) {
         list_for_each_entry(trans, &asoc->peer.transport_addr_list,
                     transports) {
             if (val->spt_pathmaxrxt)
                 trans->pathmaxrxt = val->spt_pathmaxrxt;
             if (v2)
                 trans->ps_retrans = val->spt_pathcpthld;
             trans->pf_retrans = val->spt_pathpfthld;
         }
 
         if (val->spt_pathmaxrxt)
             asoc->pathmaxrxt = val->spt_pathmaxrxt;
         if (v2)
             asoc->ps_retrans = val->spt_pathcpthld;
         asoc->pf_retrans = val->spt_pathpfthld;
     } else {
         struct sctp_sock *sp = sctp_sk(sk);
 
         if (val->spt_pathmaxrxt)
             sp->pathmaxrxt = val->spt_pathmaxrxt;
         if (v2)
             sp->ps_retrans = val->spt_pathcpthld;
         sp->pf_retrans = val->spt_pathpfthld;
     }
 
     return 0;
 }
 
 static int sctp_setsockopt_recvrcvinfo(struct sock *sk, int *val,
                        unsigned int optlen)
 {
     if (optlen < sizeof(int))
         return -EINVAL;
 
     sctp_sk(sk)->recvrcvinfo = (*val == 0) ? 0 : 1;
 
     return 0;
 }
 
 static int sctp_setsockopt_recvnxtinfo(struct sock *sk, int *val,
                        unsigned int optlen)
 {
     if (optlen < sizeof(int))
         return -EINVAL;
 
     sctp_sk(sk)->recvnxtinfo = (*val == 0) ? 0 : 1;
 
     return 0;
 }
 
 static int sctp_setsockopt_pr_supported(struct sock *sk,
                     struct sctp_assoc_value *params,
                     unsigned int optlen)
 {
     struct sctp_association *asoc;
 
     if (optlen != sizeof(*params))
         return -EINVAL;
 
     asoc = sctp_id2assoc(sk, params->assoc_id);
     if (!asoc && params->assoc_id != SCTP_FUTURE_ASSOC &&
         sctp_style(sk, UDP))
         return -EINVAL;
 
     sctp_sk(sk)->ep->prsctp_enable = !!params->assoc_value;
 
     return 0;
 }
 
 static int sctp_setsockopt_default_prinfo(struct sock *sk,
                       struct sctp_default_prinfo *info,
                       unsigned int optlen)
 {
     struct sctp_sock *sp = sctp_sk(sk);
     struct sctp_association *asoc;
     int retval = -EINVAL;
 
     if (optlen != sizeof(*info))
         goto out;
 
     if (info->pr_policy & ~SCTP_PR_SCTP_MASK)
         goto out;
 
     if (info->pr_policy == SCTP_PR_SCTP_NONE)
         info->pr_value = 0;
 
     asoc = sctp_id2assoc(sk, info->pr_assoc_id);
     if (!asoc && info->pr_assoc_id > SCTP_ALL_ASSOC &&
         sctp_style(sk, UDP))
         goto out;
 
     retval = 0;
 
     if (asoc) {
         SCTP_PR_SET_POLICY(asoc->default_flags, info->pr_policy);
         asoc->default_timetolive = info->pr_value;
         goto out;
     }
 
     if (sctp_style(sk, TCP))
         info->pr_assoc_id = SCTP_FUTURE_ASSOC;
 
     if (info->pr_assoc_id == SCTP_FUTURE_ASSOC ||
         info->pr_assoc_id == SCTP_ALL_ASSOC) {
         SCTP_PR_SET_POLICY(sp->default_flags, info->pr_policy);
         sp->default_timetolive = info->pr_value;
     }
 
     if (info->pr_assoc_id == SCTP_CURRENT_ASSOC ||
         info->pr_assoc_id == SCTP_ALL_ASSOC) {
         list_for_each_entry(asoc, &sp->ep->asocs, asocs) {
             SCTP_PR_SET_POLICY(asoc->default_flags,
                        info->pr_policy);
             asoc->default_timetolive = info->pr_value;
         }
     }
 
 out:
     return retval;
 }
 
 static int sctp_setsockopt_reconfig_supported(struct sock *sk,
                           struct sctp_assoc_value *params,
                           unsigned int optlen)
 {
     struct sctp_association *asoc;
     int retval = -EINVAL;
 
     if (optlen != sizeof(*params))
         goto out;
 
     asoc = sctp_id2assoc(sk, params->assoc_id);
     if (!asoc && params->assoc_id != SCTP_FUTURE_ASSOC &&
         sctp_style(sk, UDP))
         goto out;
 
     sctp_sk(sk)->ep->reconf_enable = !!params->assoc_value;
 
     retval = 0;
 
 out:
     return retval;
 }
 
 static int sctp_setsockopt_enable_strreset(struct sock *sk,
                        struct sctp_assoc_value *params,
                        unsigned int optlen)
 {
     struct sctp_endpoint *ep = sctp_sk(sk)->ep;
     struct sctp_association *asoc;
     int retval = -EINVAL;
 
     if (optlen != sizeof(*params))
         goto out;
 
     if (params->assoc_value & (~SCTP_ENABLE_STRRESET_MASK))
         goto out;
 
     asoc = sctp_id2assoc(sk, params->assoc_id);
     if (!asoc && params->assoc_id > SCTP_ALL_ASSOC &&
         sctp_style(sk, UDP))
         goto out;
 
     retval = 0;
 
     if (asoc) {
         asoc->strreset_enable = params->assoc_value;
         goto out;
     }
 
     if (sctp_style(sk, TCP))
         params->assoc_id = SCTP_FUTURE_ASSOC;
 
     if (params->assoc_id == SCTP_FUTURE_ASSOC ||
         params->assoc_id == SCTP_ALL_ASSOC)
         ep->strreset_enable = params->assoc_value;
 
     if (params->assoc_id == SCTP_CURRENT_ASSOC ||
         params->assoc_id == SCTP_ALL_ASSOC)
         list_for_each_entry(asoc, &ep->asocs, asocs)
             asoc->strreset_enable = params->assoc_value;
 
 out:
     return retval;
 }
 
 static int sctp_setsockopt_reset_streams(struct sock *sk,
                      struct sctp_reset_streams *params,
                      unsigned int optlen)
 {
     struct sctp_association *asoc;
 
     if (optlen < sizeof(*params))
         return -EINVAL;
     /* srs_number_streams is u16, so optlen can't be bigger than this. */
     optlen = min_t(unsigned int, optlen, USHRT_MAX +
                          sizeof(__u16) * sizeof(*params));
 
     if (params->srs_number_streams * sizeof(__u16) >
         optlen - sizeof(*params))
         return -EINVAL;
 
     asoc = sctp_id2assoc(sk, params->srs_assoc_id);
     if (!asoc)
         return -EINVAL;
 
     return sctp_send_reset_streams(asoc, params);
 }
 
 static int sctp_setsockopt_reset_assoc(struct sock *sk, sctp_assoc_t *associd,
                        unsigned int optlen)
 {
     struct sctp_association *asoc;
 
     if (optlen != sizeof(*associd))
         return -EINVAL;
 
     asoc = sctp_id2assoc(sk, *associd);
     if (!asoc)
         return -EINVAL;
 
     return sctp_send_reset_assoc(asoc);
 }
 
 static int sctp_setsockopt_add_streams(struct sock *sk,
                        struct sctp_add_streams *params,
                        unsigned int optlen)
 {
     struct sctp_association *asoc;
 
     if (optlen != sizeof(*params))
         return -EINVAL;
 
     asoc = sctp_id2assoc(sk, params->sas_assoc_id);
     if (!asoc)
         return -EINVAL;
 
     return sctp_send_add_streams(asoc, params);
 }
 
 static int sctp_setsockopt_scheduler(struct sock *sk,
                      struct sctp_assoc_value *params,
                      unsigned int optlen)
 {
     struct sctp_sock *sp = sctp_sk(sk);
     struct sctp_association *asoc;
     int retval = 0;
 
     if (optlen < sizeof(*params))
         return -EINVAL;
 
     if (params->assoc_value > SCTP_SS_MAX)
         return -EINVAL;
 
     asoc = sctp_id2assoc(sk, params->assoc_id);
     if (!asoc && params->assoc_id > SCTP_ALL_ASSOC &&
         sctp_style(sk, UDP))
         return -EINVAL;
 
     if (asoc)
         return sctp_sched_set_sched(asoc, params->assoc_value);
 
     if (sctp_style(sk, TCP))
         params->assoc_id = SCTP_FUTURE_ASSOC;
 
     if (params->assoc_id == SCTP_FUTURE_ASSOC ||
         params->assoc_id == SCTP_ALL_ASSOC)
         sp->default_ss = params->assoc_value;
 
     if (params->assoc_id == SCTP_CURRENT_ASSOC ||
         params->assoc_id == SCTP_ALL_ASSOC) {
         list_for_each_entry(asoc, &sp->ep->asocs, asocs) {
             int ret = sctp_sched_set_sched(asoc,
                                params->assoc_value);
 
             if (ret && !retval)
                 retval = ret;
         }
     }
 
     return retval;
 }
 
 static int sctp_setsockopt_scheduler_value(struct sock *sk,
                        struct sctp_stream_value *params,
                        unsigned int optlen)
 {
     struct sctp_association *asoc;
     int retval = -EINVAL;
 
     if (optlen < sizeof(*params))
         goto out;
 
     asoc = sctp_id2assoc(sk, params->assoc_id);
     if (!asoc && params->assoc_id != SCTP_CURRENT_ASSOC &&
         sctp_style(sk, UDP))
         goto out;
 
     if (asoc) {
         retval = sctp_sched_set_value(asoc, params->stream_id,
                           params->stream_value, GFP_KERNEL);
         goto out;
     }
 
     retval = 0;
 
     list_for_each_entry(asoc, &sctp_sk(sk)->ep->asocs, asocs) {
         int ret = sctp_sched_set_value(asoc, params->stream_id,
                            params->stream_value,
                            GFP_KERNEL);
         if (ret && !retval) /* try to return the 1st error. */
             retval = ret;
     }
 
 out:
     return retval;
 }
 
 static int sctp_setsockopt_interleaving_supported(struct sock *sk,
                           struct sctp_assoc_value *p,
                           unsigned int optlen)
 {
     struct sctp_sock *sp = sctp_sk(sk);
     struct sctp_association *asoc;
 
     if (optlen < sizeof(*p))
         return -EINVAL;
 
     asoc = sctp_id2assoc(sk, p->assoc_id);
     if (!asoc && p->assoc_id != SCTP_FUTURE_ASSOC && sctp_style(sk, UDP))
         return -EINVAL;
 
     if (!sock_net(sk)->sctp.intl_enable || !sp->frag_interleave) {
         return -EPERM;
     }
 
     sp->ep->intl_enable = !!p->assoc_value;
     return 0;
 }
 
 static int sctp_setsockopt_reuse_port(struct sock *sk, int *val,
                       unsigned int optlen)
 {
     if (!sctp_style(sk, TCP))
         return -EOPNOTSUPP;
 
     if (sctp_sk(sk)->ep->base.bind_addr.port)
         return -EFAULT;
 
     if (optlen < sizeof(int))
         return -EINVAL;
 
     sctp_sk(sk)->reuse = !!*val;
 
     return 0;
 }
 
 static int sctp_assoc_ulpevent_type_set(struct sctp_event *param,
                     struct sctp_association *asoc)
 {
     struct sctp_ulpevent *event;
 
     sctp_ulpevent_type_set(&asoc->subscribe, param->se_type, param->se_on);
 
     if (param->se_type == SCTP_SENDER_DRY_EVENT && param->se_on) {
         if (sctp_outq_is_empty(&asoc->outqueue)) {
             event = sctp_ulpevent_make_sender_dry_event(asoc,
                     GFP_USER | __GFP_NOWARN);
             if (!event)
                 return -ENOMEM;
 
             asoc->stream.si->enqueue_event(&asoc->ulpq, event);
         }
     }
 
     return 0;
 }
 
 static int sctp_setsockopt_event(struct sock *sk, struct sctp_event *param,
                  unsigned int optlen)
 {
     struct sctp_sock *sp = sctp_sk(sk);
     struct sctp_association *asoc;
     int retval = 0;
 
     if (optlen < sizeof(*param))
         return -EINVAL;
 
     if (param->se_type < SCTP_SN_TYPE_BASE ||
         param->se_type > SCTP_SN_TYPE_MAX)
         return -EINVAL;
 
     asoc = sctp_id2assoc(sk, param->se_assoc_id);
     if (!asoc && param->se_assoc_id > SCTP_ALL_ASSOC &&
         sctp_style(sk, UDP))
         return -EINVAL;
 
     if (asoc)
         return sctp_assoc_ulpevent_type_set(param, asoc);
 
     if (sctp_style(sk, TCP))
         param->se_assoc_id = SCTP_FUTURE_ASSOC;
 
     if (param->se_assoc_id == SCTP_FUTURE_ASSOC ||
         param->se_assoc_id == SCTP_ALL_ASSOC)
         sctp_ulpevent_type_set(&sp->subscribe,
                        param->se_type, param->se_on);
 
     if (param->se_assoc_id == SCTP_CURRENT_ASSOC ||
         param->se_assoc_id == SCTP_ALL_ASSOC) {
         list_for_each_entry(asoc, &sp->ep->asocs, asocs) {
             int ret = sctp_assoc_ulpevent_type_set(param, asoc);
 
             if (ret && !retval)
                 retval = ret;
         }
     }
 
     return retval;
 }
 
 static int sctp_setsockopt_asconf_supported(struct sock *sk,
                         struct sctp_assoc_value *params,
                         unsigned int optlen)
 {
     struct sctp_association *asoc;
     struct sctp_endpoint *ep;
     int retval = -EINVAL;
 
     if (optlen != sizeof(*params))
         goto out;
 
     asoc = sctp_id2assoc(sk, params->assoc_id);
     if (!asoc && params->assoc_id != SCTP_FUTURE_ASSOC &&
         sctp_style(sk, UDP))
         goto out;
 
     ep = sctp_sk(sk)->ep;
     ep->asconf_enable = !!params->assoc_value;
 
     if (ep->asconf_enable && ep->auth_enable) {
         sctp_auth_ep_add_chunkid(ep, SCTP_CID_ASCONF);
         sctp_auth_ep_add_chunkid(ep, SCTP_CID_ASCONF_ACK);
     }
 
     retval = 0;
 
 out:
     return retval;
 }
 
 static int sctp_setsockopt_auth_supported(struct sock *sk,
                       struct sctp_assoc_value *params,
                       unsigned int optlen)
 {
     struct sctp_association *asoc;
     struct sctp_endpoint *ep;
     int retval = -EINVAL;
 
     if (optlen != sizeof(*params))
         goto out;
 
     asoc = sctp_id2assoc(sk, params->assoc_id);
     if (!asoc && params->assoc_id != SCTP_FUTURE_ASSOC &&
         sctp_style(sk, UDP))
         goto out;
 
     ep = sctp_sk(sk)->ep;
     if (params->assoc_value) {
         retval = sctp_auth_init(ep, GFP_KERNEL);
         if (retval)
             goto out;
         if (ep->asconf_enable) {
             sctp_auth_ep_add_chunkid(ep, SCTP_CID_ASCONF);
             sctp_auth_ep_add_chunkid(ep, SCTP_CID_ASCONF_ACK);
         }
     }
 
     ep->auth_enable = !!params->assoc_value;
     retval = 0;
 
 out:
     return retval;
 }
 
 static int sctp_setsockopt_ecn_supported(struct sock *sk,
                      struct sctp_assoc_value *params,
                      unsigned int optlen)
 {
     struct sctp_association *asoc;
     int retval = -EINVAL;
 
     if (optlen != sizeof(*params))
         goto out;
 
     asoc = sctp_id2assoc(sk, params->assoc_id);
     if (!asoc && params->assoc_id != SCTP_FUTURE_ASSOC &&
         sctp_style(sk, UDP))
         goto out;
 
     sctp_sk(sk)->ep->ecn_enable = !!params->assoc_value;
     retval = 0;
 
 out:
     return retval;
 }
 
 static int sctp_setsockopt_pf_expose(struct sock *sk,
                      struct sctp_assoc_value *params,
                      unsigned int optlen)
 {
     struct sctp_association *asoc;
     int retval = -EINVAL;
 
     if (optlen != sizeof(*params))
         goto out;
 
     if (params->assoc_value > SCTP_PF_EXPOSE_MAX)
         goto out;
 
     asoc = sctp_id2assoc(sk, params->assoc_id);
     if (!asoc && params->assoc_id != SCTP_FUTURE_ASSOC &&
         sctp_style(sk, UDP))
         goto out;
 
     if (asoc)
         asoc->pf_expose = params->assoc_value;
     else
         sctp_sk(sk)->pf_expose = params->assoc_value;
     retval = 0;
 
 out:
     return retval;
 }
 
 static int sctp_setsockopt_encap_port(struct sock *sk,
                       struct sctp_udpencaps *encap,
                       unsigned int optlen)
 {
     struct sctp_association *asoc;
     struct sctp_transport *t;
     __be16 encap_port;
 
     if (optlen != sizeof(*encap))
         return -EINVAL;
 
     /* If an address other than INADDR_ANY is specified, and
      * no transport is found, then the request is invalid.
      */
     encap_port = (__force __be16)encap->sue_port;
     if (!sctp_is_any(sk, (union sctp_addr *)&encap->sue_address)) {
         t = sctp_addr_id2transport(sk, &encap->sue_address,
                        encap->sue_assoc_id);
         if (!t)
             return -EINVAL;
 
         t->encap_port = encap_port;
         return 0;
     }
 
     /* Get association, if assoc_id != SCTP_FUTURE_ASSOC and the
      * socket is a one to many style socket, and an association
      * was not found, then the id was invalid.
      */
     asoc = sctp_id2assoc(sk, encap->sue_assoc_id);
     if (!asoc && encap->sue_assoc_id != SCTP_FUTURE_ASSOC &&
         sctp_style(sk, UDP))
         return -EINVAL;
 
     /* If changes are for association, also apply encap_port to
      * each transport.
      */
     if (asoc) {
         list_for_each_entry(t, &asoc->peer.transport_addr_list,
                     transports)
             t->encap_port = encap_port;
 
         asoc->encap_port = encap_port;
         return 0;
     }
 
     sctp_sk(sk)->encap_port = encap_port;
     return 0;
 }
 
 static int sctp_setsockopt_probe_interval(struct sock *sk,
                       struct sctp_probeinterval *params,
                       unsigned int optlen)
 {
     struct sctp_association *asoc;
     struct sctp_transport *t;
     __u32 probe_interval;
 
     if (optlen != sizeof(*params))
         return -EINVAL;
 
     probe_interval = params->spi_interval;
     if (probe_interval && probe_interval < SCTP_PROBE_TIMER_MIN)
         return -EINVAL;
 
     /* If an address other than INADDR_ANY is specified, and
      * no transport is found, then the request is invalid.
      */
     if (!sctp_is_any(sk, (union sctp_addr *)&params->spi_address)) {
         t = sctp_addr_id2transport(sk, &params->spi_address,
                        params->spi_assoc_id);
         if (!t)
             return -EINVAL;
 
         t->probe_interval = msecs_to_jiffies(probe_interval);
         sctp_transport_pl_reset(t);
         return 0;
     }
 
     /* Get association, if assoc_id != SCTP_FUTURE_ASSOC and the
      * socket is a one to many style socket, and an association
      * was not found, then the id was invalid.
      */
     asoc = sctp_id2assoc(sk, params->spi_assoc_id);
     if (!asoc && params->spi_assoc_id != SCTP_FUTURE_ASSOC &&
         sctp_style(sk, UDP))
         return -EINVAL;
 
     /* If changes are for association, also apply probe_interval to
      * each transport.
      */
     if (asoc) {
         list_for_each_entry(t, &asoc->peer.transport_addr_list, transports) {
             t->probe_interval = msecs_to_jiffies(probe_interval);
             sctp_transport_pl_reset(t);
         }
 
         asoc->probe_interval = msecs_to_jiffies(probe_interval);
         return 0;
     }
 
     sctp_sk(sk)->probe_interval = probe_interval;
     return 0;
 }
 
 /* API 6.2 setsockopt(), getsockopt()
  *
  * Applications use setsockopt() and getsockopt() to set or retrieve
  * socket options.  Socket options are used to change the default
  * behavior of sockets calls.  They are described in Section 7.
  *
  * The syntax is:
  *
  *   ret = getsockopt(int sd, int level, int optname, void __user *optval,
  *                    int __user *optlen);
  *   ret = setsockopt(int sd, int level, int optname, const void __user *optval,
  *                    int optlen);
  *
  *   sd      - the socket descript.
  *   level   - set to IPPROTO_SCTP for all SCTP options.
  *   optname - the option name.
  *   optval  - the buffer to store the value of the option.
  *   optlen  - the size of the buffer.
  */
 static int sctp_setsockopt(struct sock *sk, int level, int optname,
                sockptr_t optval, unsigned int optlen)
 {
     void *kopt = NULL;
     int retval = 0;
 
     pr_debug("%s: sk:%p, optname:%d\n", __func__, sk, optname);
 
     /* I can hardly begin to describe how wrong this is.  This is
      * so broken as to be worse than useless.  The API draft
      * REALLY is NOT helpful here...  I am not convinced that the
      * semantics of setsockopt() with a level OTHER THAN SOL_SCTP
      * are at all well-founded.
      */
     if (level != SOL_SCTP) {
         struct sctp_af *af = sctp_sk(sk)->pf->af;
 
         return af->setsockopt(sk, level, optname, optval, optlen);
     }
 
     if (optlen > 0) {
         /* Trim it to the biggest size sctp sockopt may need if necessary */
         optlen = min_t(unsigned int, optlen,
                    PAGE_ALIGN(USHRT_MAX +
                       sizeof(__u16) * sizeof(struct sctp_reset_streams)));
         kopt = memdup_sockptr(optval, optlen);
         if (IS_ERR(kopt))
             return PTR_ERR(kopt);
     }
 
     lock_sock(sk);
 
     switch (optname) {
     case SCTP_SOCKOPT_BINDX_ADD:
         /* 'optlen' is the size of the addresses buffer. */
         retval = sctp_setsockopt_bindx(sk, kopt, optlen,
                            SCTP_BINDX_ADD_ADDR);
         break;
 
     case SCTP_SOCKOPT_BINDX_REM:
         /* 'optlen' is the size of the addresses buffer. */
         retval = sctp_setsockopt_bindx(sk, kopt, optlen,
                            SCTP_BINDX_REM_ADDR);
         break;
 
     case SCTP_SOCKOPT_CONNECTX_OLD:
         /* 'optlen' is the size of the addresses buffer. */
         retval = sctp_setsockopt_connectx_old(sk, kopt, optlen);
         break;
 
     case SCTP_SOCKOPT_CONNECTX:
         /* 'optlen' is the size of the addresses buffer. */
         retval = sctp_setsockopt_connectx(sk, kopt, optlen);
         break;
 
     case SCTP_DISABLE_FRAGMENTS:
         retval = sctp_setsockopt_disable_fragments(sk, kopt, optlen);
         break;
 
     case SCTP_EVENTS:
         retval = sctp_setsockopt_events(sk, kopt, optlen);
         break;
 
     case SCTP_AUTOCLOSE:
         retval = sctp_setsockopt_autoclose(sk, kopt, optlen);
         break;
 
     case SCTP_PEER_ADDR_PARAMS:
         retval = sctp_setsockopt_peer_addr_params(sk, kopt, optlen);
         break;
 
     case SCTP_DELAYED_SACK:
         retval = sctp_setsockopt_delayed_ack(sk, kopt, optlen);
         break;
     case SCTP_PARTIAL_DELIVERY_POINT:
         retval = sctp_setsockopt_partial_delivery_point(sk, kopt, optlen);
         break;
 
     case SCTP_INITMSG:
         retval = sctp_setsockopt_initmsg(sk, kopt, optlen);
         break;
     case SCTP_DEFAULT_SEND_PARAM:
         retval = sctp_setsockopt_default_send_param(sk, kopt, optlen);
         break;
     case SCTP_DEFAULT_SNDINFO:
         retval = sctp_setsockopt_default_sndinfo(sk, kopt, optlen);
         break;
     case SCTP_PRIMARY_ADDR:
         retval = sctp_setsockopt_primary_addr(sk, kopt, optlen);
         break;
     case SCTP_SET_PEER_PRIMARY_ADDR:
         retval = sctp_setsockopt_peer_primary_addr(sk, kopt, optlen);
         break;
     case SCTP_NODELAY:
         retval = sctp_setsockopt_nodelay(sk, kopt, optlen);
         break;
     case SCTP_RTOINFO:
         retval = sctp_setsockopt_rtoinfo(sk, kopt, optlen);
         break;
     case SCTP_ASSOCINFO:
         retval = sctp_setsockopt_associnfo(sk, kopt, optlen);
         break;
     case SCTP_I_WANT_MAPPED_V4_ADDR:
         retval = sctp_setsockopt_mappedv4(sk, kopt, optlen);
         break;
     case SCTP_MAXSEG:
         retval = sctp_setsockopt_maxseg(sk, kopt, optlen);
         break;
     case SCTP_ADAPTATION_LAYER:
         retval = sctp_setsockopt_adaptation_layer(sk, kopt, optlen);
         break;
     case SCTP_CONTEXT:
         retval = sctp_setsockopt_context(sk, kopt, optlen);
         break;
     case SCTP_FRAGMENT_INTERLEAVE:
         retval = sctp_setsockopt_fragment_interleave(sk, kopt, optlen);
         break;
     case SCTP_MAX_BURST:
         retval = sctp_setsockopt_maxburst(sk, kopt, optlen);
         break;
     case SCTP_AUTH_CHUNK:
         retval = sctp_setsockopt_auth_chunk(sk, kopt, optlen);
         break;
     case SCTP_HMAC_IDENT:
         retval = sctp_setsockopt_hmac_ident(sk, kopt, optlen);
         break;
     case SCTP_AUTH_KEY:
         retval = sctp_setsockopt_auth_key(sk, kopt, optlen);
         break;
     case SCTP_AUTH_ACTIVE_KEY:
         retval = sctp_setsockopt_active_key(sk, kopt, optlen);
         break;
     case SCTP_AUTH_DELETE_KEY:
         retval = sctp_setsockopt_del_key(sk, kopt, optlen);
         break;
     case SCTP_AUTH_DEACTIVATE_KEY:
         retval = sctp_setsockopt_deactivate_key(sk, kopt, optlen);
         break;
     case SCTP_AUTO_ASCONF:
         retval = sctp_setsockopt_auto_asconf(sk, kopt, optlen);
         break;
     case SCTP_PEER_ADDR_THLDS:
         retval = sctp_setsockopt_paddr_thresholds(sk, kopt, optlen,
                               false);
         break;
     case SCTP_PEER_ADDR_THLDS_V2:
         retval = sctp_setsockopt_paddr_thresholds(sk, kopt, optlen,
                               true);
         break;
     case SCTP_RECVRCVINFO:
         retval = sctp_setsockopt_recvrcvinfo(sk, kopt, optlen);
         break;
     case SCTP_RECVNXTINFO:
         retval = sctp_setsockopt_recvnxtinfo(sk, kopt, optlen);
         break;
     case SCTP_PR_SUPPORTED:
         retval = sctp_setsockopt_pr_supported(sk, kopt, optlen);
         break;
     case SCTP_DEFAULT_PRINFO:
         retval = sctp_setsockopt_default_prinfo(sk, kopt, optlen);
         break;
     case SCTP_RECONFIG_SUPPORTED:
         retval = sctp_setsockopt_reconfig_supported(sk, kopt, optlen);
         break;
     case SCTP_ENABLE_STREAM_RESET:
         retval = sctp_setsockopt_enable_strreset(sk, kopt, optlen);
         break;
     case SCTP_RESET_STREAMS:
         retval = sctp_setsockopt_reset_streams(sk, kopt, optlen);
         break;
     case SCTP_RESET_ASSOC:
         retval = sctp_setsockopt_reset_assoc(sk, kopt, optlen);
         break;
     case SCTP_ADD_STREAMS:
         retval = sctp_setsockopt_add_streams(sk, kopt, optlen);
         break;
     case SCTP_STREAM_SCHEDULER:
         retval = sctp_setsockopt_scheduler(sk, kopt, optlen);
         break;
     case SCTP_STREAM_SCHEDULER_VALUE:
         retval = sctp_setsockopt_scheduler_value(sk, kopt, optlen);
         break;
     case SCTP_INTERLEAVING_SUPPORTED:
         retval = sctp_setsockopt_interleaving_supported(sk, kopt,
                                 optlen);
         break;
     case SCTP_REUSE_PORT:
         retval = sctp_setsockopt_reuse_port(sk, kopt, optlen);
         break;
     case SCTP_EVENT:
         retval = sctp_setsockopt_event(sk, kopt, optlen);
         break;
     case SCTP_ASCONF_SUPPORTED:
         retval = sctp_setsockopt_asconf_supported(sk, kopt, optlen);
         break;
     case SCTP_AUTH_SUPPORTED:
         retval = sctp_setsockopt_auth_supported(sk, kopt, optlen);
         break;
     case SCTP_ECN_SUPPORTED:
         retval = sctp_setsockopt_ecn_supported(sk, kopt, optlen);
         break;
     case SCTP_EXPOSE_POTENTIALLY_FAILED_STATE:
         retval = sctp_setsockopt_pf_expose(sk, kopt, optlen);
         break;
     case SCTP_REMOTE_UDP_ENCAPS_PORT:
         retval = sctp_setsockopt_encap_port(sk, kopt, optlen);
         break;
     case SCTP_PLPMTUD_PROBE_INTERVAL:
         retval = sctp_setsockopt_probe_interval(sk, kopt, optlen);
         break;
     default:
         retval = -ENOPROTOOPT;
         break;
     }
 
     release_sock(sk);
     kfree(kopt);
     return retval;
 }
 
 /* API 3.1.6 connect() - UDP Style Syntax
  *
  * An application may use the connect() call in the UDP model to initiate an
  * association without sending data.
  *
  * The syntax is:
  *
  * ret = connect(int sd, const struct sockaddr *nam, socklen_t len);
  *
  * sd: the socket descriptor to have a new association added to.
  *
  * nam: the address structure (either struct sockaddr_in or struct
  *    sockaddr_in6 defined in RFC2553 [7]).
  *
  * len: the size of the address.
  */
 static int sctp_connect(struct sock *sk, struct sockaddr *addr,
             int addr_len, int flags)
 {
     struct sctp_af *af;
     int err = -EINVAL;
 
     lock_sock(sk);
     pr_debug("%s: sk:%p, sockaddr:%p, addr_len:%d\n", __func__, sk,
          addr, addr_len);
 
     /* Validate addr_len before calling common connect/connectx routine. */
     af = sctp_get_af_specific(addr->sa_family);
     if (af && addr_len >= af->sockaddr_len)
         err = __sctp_connect(sk, addr, af->sockaddr_len, flags, NULL);
 
     release_sock(sk);
     return err;
 }
 
 int sctp_inet_connect(struct socket *sock, struct sockaddr *uaddr,
               int addr_len, int flags)
 {
     if (addr_len < sizeof(uaddr->sa_family))
         return -EINVAL;
 
     if (uaddr->sa_family == AF_UNSPEC)
         return -EOPNOTSUPP;
 
     return sctp_connect(sock->sk, uaddr, addr_len, flags);
 }
 
 /* FIXME: Write comments. */
 static int sctp_disconnect(struct sock *sk, int flags)
 {
     return -EOPNOTSUPP; /* STUB */
 }
 
 /* 4.1.4 accept() - TCP Style Syntax
  *
  * Applications use accept() call to remove an established SCTP
  * association from the accept queue of the endpoint.  A new socket
  * descriptor will be returned from accept() to represent the newly
  * formed association.
  */
 static struct sock *sctp_accept(struct sock *sk, int flags, int *err, bool kern)
 {
     struct sctp_sock *sp;
     struct sctp_endpoint *ep;
     struct sock *newsk = NULL;
     struct sctp_association *asoc;
     long timeo;
     int error = 0;
 
     lock_sock(sk);
 
     sp = sctp_sk(sk);
     ep = sp->ep;
 
     if (!sctp_style(sk, TCP)) {
         error = -EOPNOTSUPP;
         goto out;
     }
 
     if (!sctp_sstate(sk, LISTENING)) {
         error = -EINVAL;
         goto out;
     }
 
     timeo = sock_rcvtimeo(sk, flags & O_NONBLOCK);
 
     error = sctp_wait_for_accept(sk, timeo);
     if (error)
         goto out;
 
     /* We treat the list of associations on the endpoint as the accept
      * queue and pick the first association on the list.
      */
     asoc = list_entry(ep->asocs.next, struct sctp_association, asocs);
 
     newsk = sp->pf->create_accept_sk(sk, asoc, kern);
     if (!newsk) {
         error = -ENOMEM;
         goto out;
     }
 
     /* Populate the fields of the newsk from the oldsk and migrate the
      * asoc to the newsk.
      */
     error = sctp_sock_migrate(sk, newsk, asoc, SCTP_SOCKET_TCP);
     if (error) {
         sk_common_release(newsk);
         newsk = NULL;
     }
 
 out:
     release_sock(sk);
     *err = error;
     return newsk;
 }
 
 /* The SCTP ioctl handler. */
 static int sctp_ioctl(struct sock *sk, int cmd, unsigned long arg)
 {
     int rc = -ENOTCONN;
 
     lock_sock(sk);
 
     /*
      * SEQPACKET-style sockets in LISTENING state are valid, for
      * SCTP, so only discard TCP-style sockets in LISTENING state.
      */
     if (sctp_style(sk, TCP) && sctp_sstate(sk, LISTENING))
         goto out;
 
     switch (cmd) {
     case SIOCINQ: {
         struct sk_buff *skb;
         unsigned int amount = 0;
 
         skb = skb_peek(&sk->sk_receive_queue);
         if (skb != NULL) {
             /*
              * We will only return the amount of this packet since
              * that is all that will be read.
              */
             amount = skb->len;
         }
         rc = put_user(amount, (int __user *)arg);
         break;
     }
     default:
         rc = -ENOIOCTLCMD;
         break;
     }
 out:
     release_sock(sk);
     return rc;
 }
 
 /* This is the function which gets called during socket creation to
  * initialized the SCTP-specific portion of the sock.
  * The sock structure should already be zero-filled memory.
  */
 static int sctp_init_sock(struct sock *sk)
 {
     struct net *net = sock_net(sk);
     struct sctp_sock *sp;
 
     pr_debug("%s: sk:%p\n", __func__, sk);
 
     sp = sctp_sk(sk);
 
     /* Initialize the SCTP per socket area.  */
     switch (sk->sk_type) {
     case SOCK_SEQPACKET:
         sp->type = SCTP_SOCKET_UDP;
         break;
     case SOCK_STREAM:
         sp->type = SCTP_SOCKET_TCP;
         break;
     default:
         return -ESOCKTNOSUPPORT;
     }
 
     sk->sk_gso_type = SKB_GSO_SCTP;
 
     /* Initialize default send parameters. These parameters can be
      * modified with the SCTP_DEFAULT_SEND_PARAM socket option.
      */
     sp->default_stream = 0;
     sp->default_ppid = 0;
     sp->default_flags = 0;
     sp->default_context = 0;
     sp->default_timetolive = 0;
 
     sp->default_rcv_context = 0;
     sp->max_burst = net->sctp.max_burst;
 
     sp->sctp_hmac_alg = net->sctp.sctp_hmac_alg;
 
     /* Initialize default setup parameters. These parameters
      * can be modified with the SCTP_INITMSG socket option or
      * overridden by the SCTP_INIT CMSG.
      */
     sp->initmsg.sinit_num_ostreams   = sctp_max_outstreams;
     sp->initmsg.sinit_max_instreams  = sctp_max_instreams;
     sp->initmsg.sinit_max_attempts   = net->sctp.max_retrans_init;
     sp->initmsg.sinit_max_init_timeo = net->sctp.rto_max;
 
     /* Initialize default RTO related parameters.  These parameters can
      * be modified for with the SCTP_RTOINFO socket option.
      */
     sp->rtoinfo.srto_initial = net->sctp.rto_initial;
     sp->rtoinfo.srto_max     = net->sctp.rto_max;
     sp->rtoinfo.srto_min     = net->sctp.rto_min;
 
     /* Initialize default association related parameters. These parameters
      * can be modified with the SCTP_ASSOCINFO socket option.
      */
     sp->assocparams.sasoc_asocmaxrxt = net->sctp.max_retrans_association;
     sp->assocparams.sasoc_number_peer_destinations = 0;
     sp->assocparams.sasoc_peer_rwnd = 0;
     sp->assocparams.sasoc_local_rwnd = 0;
     sp->assocparams.sasoc_cookie_life = net->sctp.valid_cookie_life;
 
     /* Initialize default event subscriptions. By default, all the
      * options are off.
      */
     sp->subscribe = 0;
 
     /* Default Peer Address Parameters.  These defaults can
      * be modified via SCTP_PEER_ADDR_PARAMS
      */
     sp->hbinterval  = net->sctp.hb_interval;
     sp->udp_port    = htons(net->sctp.udp_port);
     sp->encap_port  = htons(net->sctp.encap_port);
     sp->pathmaxrxt  = net->sctp.max_retrans_path;
     sp->pf_retrans  = net->sctp.pf_retrans;
     sp->ps_retrans  = net->sctp.ps_retrans;
     sp->pf_expose   = net->sctp.pf_expose;
     sp->pathmtu     = 0; /* allow default discovery */
     sp->sackdelay   = net->sctp.sack_timeout;
     sp->sackfreq    = 2;
     sp->param_flags = SPP_HB_ENABLE |
               SPP_PMTUD_ENABLE |
               SPP_SACKDELAY_ENABLE;
     sp->default_ss = SCTP_SS_DEFAULT;
 
     /* If enabled no SCTP message fragmentation will be performed.
      * Configure through SCTP_DISABLE_FRAGMENTS socket option.
      */
     sp->disable_fragments = 0;
 
     /* Enable Nagle algorithm by default.  */
     sp->nodelay           = 0;
 
     sp->recvrcvinfo = 0;
     sp->recvnxtinfo = 0;
 
     /* Enable by default. */
     sp->v4mapped          = 1;
 
     /* Auto-close idle associations after the configured
      * number of seconds.  A value of 0 disables this
      * feature.  Configure through the SCTP_AUTOCLOSE socket option,
      * for UDP-style sockets only.
      */
     sp->autoclose         = 0;
 
     /* User specified fragmentation limit. */
     sp->user_frag         = 0;
 
     sp->adaptation_ind = 0;
 
     sp->pf = sctp_get_pf_specific(sk->sk_family);
 
     /* Control variables for partial data delivery. */
     atomic_set(&sp->pd_mode, 0);
     skb_queue_head_init(&sp->pd_lobby);
     sp->frag_interleave = 0;
     sp->probe_interval = net->sctp.probe_interval;
 
     /* Create a per socket endpoint structure.  Even if we
      * change the data structure relationships, this may still
      * be useful for storing pre-connect address information.
      */
     sp->ep = sctp_endpoint_new(sk, GFP_KERNEL);
     if (!sp->ep)
         return -ENOMEM;
 
     sp->hmac = NULL;
 
     sk->sk_destruct = sctp_destruct_sock;
 
     SCTP_DBG_OBJCNT_INC(sock);
 
     sk_sockets_allocated_inc(sk);
     sock_prot_inuse_add(net, sk->sk_prot, 1);
 
     return 0;
 }
 
 /* Cleanup any SCTP per socket resources. Must be called with
  * sock_net(sk)->sctp.addr_wq_lock held if sp->do_auto_asconf is true
  */
 static void sctp_destroy_sock(struct sock *sk)
 {
     struct sctp_sock *sp;
 
     pr_debug("%s: sk:%p\n", __func__, sk);
 
     /* Release our hold on the endpoint. */
     sp = sctp_sk(sk);
     /* This could happen during socket init, thus we bail out
      * early, since the rest of the below is not setup either.
      */
     if (sp->ep == NULL)
         return;
 
     if (sp->do_auto_asconf) {
         sp->do_auto_asconf = 0;
         list_del(&sp->auto_asconf_list);
     }
     sctp_endpoint_free(sp->ep);
     sk_sockets_allocated_dec(sk);
     sock_prot_inuse_add(sock_net(sk), sk->sk_prot, -1);
 }
 
 /* Triggered when there are no references on the socket anymore */
 static void sctp_destruct_sock(struct sock *sk)
 {
     struct sctp_sock *sp = sctp_sk(sk);
 
     /* Free up the HMAC transform. */
     crypto_free_shash(sp->hmac);
 
     inet_sock_destruct(sk);
 }
 
 /* API 4.1.7 shutdown() - TCP Style Syntax
  *     int shutdown(int socket, int how);
  *
  *     sd      - the socket descriptor of the association to be closed.
  *     how     - Specifies the type of shutdown.  The  values  are
  *               as follows:
  *               SHUT_RD
  *                     Disables further receive operations. No SCTP
  *                     protocol action is taken.
  *               SHUT_WR
  *                     Disables further send operations, and initiates
  *                     the SCTP shutdown sequence.
  *               SHUT_RDWR
  *                     Disables further send  and  receive  operations
  *                     and initiates the SCTP shutdown sequence.
  */
 static void sctp_shutdown(struct sock *sk, int how)
 {
     struct net *net = sock_net(sk);
     struct sctp_endpoint *ep;
 
     if (!sctp_style(sk, TCP))
         return;
 
     ep = sctp_sk(sk)->ep;
     if (how & SEND_SHUTDOWN && !list_empty(&ep->asocs)) {
         struct sctp_association *asoc;
 
         inet_sk_set_state(sk, SCTP_SS_CLOSING);
         asoc = list_entry(ep->asocs.next,
                   struct sctp_association, asocs);
         sctp_primitive_SHUTDOWN(net, asoc, NULL);
     }
 }
 
 int sctp_get_sctp_info(struct sock *sk, struct sctp_association *asoc,
                struct sctp_info *info)
 {
     struct sctp_transport *prim;
     struct list_head *pos;
     int mask;
 
     memset(info, 0, sizeof(*info));
     if (!asoc) {
         struct sctp_sock *sp = sctp_sk(sk);
 
         info->sctpi_s_autoclose = sp->autoclose;
         info->sctpi_s_adaptation_ind = sp->adaptation_ind;
         info->sctpi_s_pd_point = sp->pd_point;
         info->sctpi_s_nodelay = sp->nodelay;
         info->sctpi_s_disable_fragments = sp->disable_fragments;
         info->sctpi_s_v4mapped = sp->v4mapped;
         info->sctpi_s_frag_interleave = sp->frag_interleave;
         info->sctpi_s_type = sp->type;
 
         return 0;
     }
 
     info->sctpi_tag = asoc->c.my_vtag;
     info->sctpi_state = asoc->state;
     info->sctpi_rwnd = asoc->a_rwnd;
     info->sctpi_unackdata = asoc->unack_data;
     info->sctpi_penddata = sctp_tsnmap_pending(&asoc->peer.tsn_map);
     info->sctpi_instrms = asoc->stream.incnt;
     info->sctpi_outstrms = asoc->stream.outcnt;
     list_for_each(pos, &asoc->base.inqueue.in_chunk_list)
         info->sctpi_inqueue++;
     list_for_each(pos, &asoc->outqueue.out_chunk_list)
         info->sctpi_outqueue++;
     info->sctpi_overall_error = asoc->overall_error_count;
     info->sctpi_max_burst = asoc->max_burst;
     info->sctpi_maxseg = asoc->frag_point;
     info->sctpi_peer_rwnd = asoc->peer.rwnd;
     info->sctpi_peer_tag = asoc->c.peer_vtag;
 
     mask = asoc->peer.ecn_capable << 1;
     mask = (mask | asoc->peer.ipv4_address) << 1;
     mask = (mask | asoc->peer.ipv6_address) << 1;
     mask = (mask | asoc->peer.hostname_address) << 1;
     mask = (mask | asoc->peer.asconf_capable) << 1;
     mask = (mask | asoc->peer.prsctp_capable) << 1;
     mask = (mask | asoc->peer.auth_capable);
     info->sctpi_peer_capable = mask;
     mask = asoc->peer.sack_needed << 1;
     mask = (mask | asoc->peer.sack_generation) << 1;
     mask = (mask | asoc->peer.zero_window_announced);
     info->sctpi_peer_sack = mask;
 
     info->sctpi_isacks = asoc->stats.isacks;
     info->sctpi_osacks = asoc->stats.osacks;
     info->sctpi_opackets = asoc->stats.opackets;
     info->sctpi_ipackets = asoc->stats.ipackets;
     info->sctpi_rtxchunks = asoc->stats.rtxchunks;
     info->sctpi_outofseqtsns = asoc->stats.outofseqtsns;
     info->sctpi_idupchunks = asoc->stats.idupchunks;
     info->sctpi_gapcnt = asoc->stats.gapcnt;
     info->sctpi_ouodchunks = asoc->stats.ouodchunks;
     info->sctpi_iuodchunks = asoc->stats.iuodchunks;
     info->sctpi_oodchunks = asoc->stats.oodchunks;
     info->sctpi_iodchunks = asoc->stats.iodchunks;
     info->sctpi_octrlchunks = asoc->stats.octrlchunks;
     info->sctpi_ictrlchunks = asoc->stats.ictrlchunks;
 
     prim = asoc->peer.primary_path;
     memcpy(&info->sctpi_p_address, &prim->ipaddr, sizeof(prim->ipaddr));
     info->sctpi_p_state = prim->state;
     info->sctpi_p_cwnd = prim->cwnd;
     info->sctpi_p_srtt = prim->srtt;
     info->sctpi_p_rto = jiffies_to_msecs(prim->rto);
     info->sctpi_p_hbinterval = prim->hbinterval;
     info->sctpi_p_pathmaxrxt = prim->pathmaxrxt;
     info->sctpi_p_sackdelay = jiffies_to_msecs(prim->sackdelay);
     info->sctpi_p_ssthresh = prim->ssthresh;
     info->sctpi_p_partial_bytes_acked = prim->partial_bytes_acked;
     info->sctpi_p_flight_size = prim->flight_size;
     info->sctpi_p_error = prim->error_count;
 
     return 0;
 }
 EXPORT_SYMBOL_GPL(sctp_get_sctp_info);
 
 /* use callback to avoid exporting the core structure */
 void sctp_transport_walk_start(struct rhashtable_iter *iter) __acquires(RCU)
 {
     rhltable_walk_enter(&sctp_transport_hashtable, iter);
 
     rhashtable_walk_start(iter);
 }
 
 void sctp_transport_walk_stop(struct rhashtable_iter *iter) __releases(RCU)
 {
     rhashtable_walk_stop(iter);
     rhashtable_walk_exit(iter);
 }
 
 struct sctp_transport *sctp_transport_get_next(struct net *net,
                            struct rhashtable_iter *iter)
 {
     struct sctp_transport *t;
 
     t = rhashtable_walk_next(iter);
     for (; t; t = rhashtable_walk_next(iter)) {
         if (IS_ERR(t)) {
             if (PTR_ERR(t) == -EAGAIN)
                 continue;
             break;
         }
 
         if (!sctp_transport_hold(t))
             continue;
 
         if (net_eq(t->asoc->base.net, net) &&
             t->asoc->peer.primary_path == t)
             break;
 
         sctp_transport_put(t);
     }
 
     return t;
 }
 
 struct sctp_transport *sctp_transport_get_idx(struct net *net,
                           struct rhashtable_iter *iter,
                           int pos)
 {
     struct sctp_transport *t;
 
     if (!pos)
         return SEQ_START_TOKEN;
 
     while ((t = sctp_transport_get_next(net, iter)) && !IS_ERR(t)) {
         if (!--pos)
             break;
         sctp_transport_put(t);
     }
 
     return t;
 }
 
 int sctp_for_each_endpoint(int (*cb)(struct sctp_endpoint *, void *),
                void *p) {
     int err = 0;
     int hash = 0;
     struct sctp_endpoint *ep;
     struct sctp_hashbucket *head;
 
     for (head = sctp_ep_hashtable; hash < sctp_ep_hashsize;
          hash++, head++) {
         read_lock_bh(&head->lock);
         sctp_for_each_hentry(ep, &head->chain) {
             err = cb(ep, p);
             if (err)
                 break;
         }
         read_unlock_bh(&head->lock);
     }
 
     return err;
 }
 EXPORT_SYMBOL_GPL(sctp_for_each_endpoint);
 
 int sctp_transport_lookup_process(sctp_callback_t cb, struct net *net,
                   const union sctp_addr *laddr,
                   const union sctp_addr *paddr, void *p)
 {
     struct sctp_transport *transport;
     struct sctp_endpoint *ep;
     int err = -ENOENT;
 
     rcu_read_lock();
     transport = sctp_addrs_lookup_transport(net, laddr, paddr);
     if (!transport) {
         rcu_read_unlock();
         return err;
     }
     ep = transport->asoc->ep;
     if (!sctp_endpoint_hold(ep)) { /* asoc can be peeled off */
         sctp_transport_put(transport);
         rcu_read_unlock();
         return err;
     }
     rcu_read_unlock();
 
     err = cb(ep, transport, p);
     sctp_endpoint_put(ep);
     sctp_transport_put(transport);
     return err;
 }
 EXPORT_SYMBOL_GPL(sctp_transport_lookup_process);
 
 int sctp_transport_traverse_process(sctp_callback_t cb, sctp_callback_t cb_done,
                     struct net *net, int *pos, void *p)
 {
     struct rhashtable_iter hti;
     struct sctp_transport *tsp;
     struct sctp_endpoint *ep;
     int ret;
 
 again:
     ret = 0;
     sctp_transport_walk_start(&hti);
 
     tsp = sctp_transport_get_idx(net, &hti, *pos + 1);
     for (; !IS_ERR_OR_NULL(tsp); tsp = sctp_transport_get_next(net, &hti)) {
         ep = tsp->asoc->ep;
         if (sctp_endpoint_hold(ep)) { /* asoc can be peeled off */
             ret = cb(ep, tsp, p);
             if (ret)
                 break;
             sctp_endpoint_put(ep);
         }
         (*pos)++;
         sctp_transport_put(tsp);
     }
     sctp_transport_walk_stop(&hti);
 
     if (ret) {
         if (cb_done && !cb_done(ep, tsp, p)) {
             (*pos)++;
             sctp_endpoint_put(ep);
             sctp_transport_put(tsp);
             goto again;
         }
         sctp_endpoint_put(ep);
         sctp_transport_put(tsp);
     }
 
     return ret;
 }
 EXPORT_SYMBOL_GPL(sctp_transport_traverse_process);
 
 /* 7.2.1 Association Status (SCTP_STATUS)
 
  * Applications can retrieve current status information about an
  * association, including association state, peer receiver window size,
  * number of unacked data chunks, and number of data chunks pending
  * receipt.  This information is read-only.
  */
 static int sctp_getsockopt_sctp_status(struct sock *sk, int len,
                        char __user *optval,
                        int __user *optlen)
 {
     struct sctp_status status;
     struct sctp_association *asoc = NULL;
     struct sctp_transport *transport;
     sctp_assoc_t associd;
     int retval = 0;
 
     if (len < sizeof(status)) {
         retval = -EINVAL;
         goto out;
     }
 
     len = sizeof(status);
     if (copy_from_user(&status, optval, len)) {
         retval = -EFAULT;
         goto out;
     }
 
     associd = status.sstat_assoc_id;
     asoc = sctp_id2assoc(sk, associd);
     if (!asoc) {
         retval = -EINVAL;
         goto out;
     }
 
     transport = asoc->peer.primary_path;
 
     status.sstat_assoc_id = sctp_assoc2id(asoc);
     status.sstat_state = sctp_assoc_to_state(asoc);
     status.sstat_rwnd =  asoc->peer.rwnd;
     status.sstat_unackdata = asoc->unack_data;
 
     status.sstat_penddata = sctp_tsnmap_pending(&asoc->peer.tsn_map);
     status.sstat_instrms = asoc->stream.incnt;
     status.sstat_outstrms = asoc->stream.outcnt;
     status.sstat_fragmentation_point = asoc->frag_point;
     status.sstat_primary.spinfo_assoc_id = sctp_assoc2id(transport->asoc);
     memcpy(&status.sstat_primary.spinfo_address, &transport->ipaddr,
             transport->af_specific->sockaddr_len);
     /* Map ipv4 address into v4-mapped-on-v6 address.  */
     sctp_get_pf_specific(sk->sk_family)->addr_to_user(sctp_sk(sk),
         (union sctp_addr *)&status.sstat_primary.spinfo_address);
     status.sstat_primary.spinfo_state = transport->state;
     status.sstat_primary.spinfo_cwnd = transport->cwnd;
     status.sstat_primary.spinfo_srtt = transport->srtt;
     status.sstat_primary.spinfo_rto = jiffies_to_msecs(transport->rto);
     status.sstat_primary.spinfo_mtu = transport->pathmtu;
 
     if (status.sstat_primary.spinfo_state == SCTP_UNKNOWN)
         status.sstat_primary.spinfo_state = SCTP_ACTIVE;
 
     if (put_user(len, optlen)) {
         retval = -EFAULT;
         goto out;
     }
 
     pr_debug("%s: len:%d, state:%d, rwnd:%d, assoc_id:%d\n",
          __func__, len, status.sstat_state, status.sstat_rwnd,
          status.sstat_assoc_id);
 
     if (copy_to_user(optval, &status, len)) {
         retval = -EFAULT;
         goto out;
     }
 
 out:
     return retval;
 }
 
 
 /* 7.2.2 Peer Address Information (SCTP_GET_PEER_ADDR_INFO)
  *
  * Applications can retrieve information about a specific peer address
  * of an association, including its reachability state, congestion
  * window, and retransmission timer values.  This information is
  * read-only.
  */
 static int sctp_getsockopt_peer_addr_info(struct sock *sk, int len,
                       char __user *optval,
                       int __user *optlen)
 {
     struct sctp_paddrinfo pinfo;
     struct sctp_transport *transport;
     int retval = 0;
 
     if (len < sizeof(pinfo)) {
         retval = -EINVAL;
         goto out;
     }
 
     len = sizeof(pinfo);
     if (copy_from_user(&pinfo, optval, len)) {
         retval = -EFAULT;
         goto out;
     }
 
     transport = sctp_addr_id2transport(sk, &pinfo.spinfo_address,
                        pinfo.spinfo_assoc_id);
     if (!transport) {
         retval = -EINVAL;
         goto out;
     }
 
     if (transport->state == SCTP_PF &&
         transport->asoc->pf_expose == SCTP_PF_EXPOSE_DISABLE) {
         retval = -EACCES;
         goto out;
     }
 
     pinfo.spinfo_assoc_id = sctp_assoc2id(transport->asoc);
     pinfo.spinfo_state = transport->state;
     pinfo.spinfo_cwnd = transport->cwnd;
     pinfo.spinfo_srtt = transport->srtt;
     pinfo.spinfo_rto = jiffies_to_msecs(transport->rto);
     pinfo.spinfo_mtu = transport->pathmtu;
 
     if (pinfo.spinfo_state == SCTP_UNKNOWN)
         pinfo.spinfo_state = SCTP_ACTIVE;
 
     if (put_user(len, optlen)) {
         retval = -EFAULT;
         goto out;
     }
 
     if (copy_to_user(optval, &pinfo, len)) {
         retval = -EFAULT;
         goto out;
     }
 
 out:
     return retval;
 }
 
 /* 7.1.12 Enable/Disable message fragmentation (SCTP_DISABLE_FRAGMENTS)
  *
  * This option is a on/off flag.  If enabled no SCTP message
  * fragmentation will be performed.  Instead if a message being sent
  * exceeds the current PMTU size, the message will NOT be sent and
  * instead a error will be indicated to the user.
  */
 static int sctp_getsockopt_disable_fragments(struct sock *sk, int len,
                     char __user *optval, int __user *optlen)
 {
     int val;
 
     if (len < sizeof(int))
         return -EINVAL;
 
     len = sizeof(int);
     val = (sctp_sk(sk)->disable_fragments == 1);
     if (put_user(len, optlen))
         return -EFAULT;
     if (copy_to_user(optval, &val, len))
         return -EFAULT;
     return 0;
 }
 
 /* 7.1.15 Set notification and ancillary events (SCTP_EVENTS)
  *
  * This socket option is used to specify various notifications and
  * ancillary data the user wishes to receive.
  */
 static int sctp_getsockopt_events(struct sock *sk, int len, char __user *optval,
                   int __user *optlen)
 {
     struct sctp_event_subscribe subscribe;
     __u8 *sn_type = (__u8 *)&subscribe;
     int i;
 
     if (len == 0)
         return -EINVAL;
     if (len > sizeof(struct sctp_event_subscribe))
         len = sizeof(struct sctp_event_subscribe);
     if (put_user(len, optlen))
         return -EFAULT;
 
     for (i = 0; i < len; i++)
         sn_type[i] = sctp_ulpevent_type_enabled(sctp_sk(sk)->subscribe,
                             SCTP_SN_TYPE_BASE + i);
 
     if (copy_to_user(optval, &subscribe, len))
         return -EFAULT;
 
     return 0;
 }
 
 /* 7.1.8 Automatic Close of associations (SCTP_AUTOCLOSE)
  *
  * This socket option is applicable to the UDP-style socket only.  When
  * set it will cause associations that are idle for more than the
  * specified number of seconds to automatically close.  An association
  * being idle is defined an association that has NOT sent or received
  * user data.  The special value of '0' indicates that no automatic
  * close of any associations should be performed.  The option expects an
  * integer defining the number of seconds of idle time before an
  * association is closed.
  */
 static int sctp_getsockopt_autoclose(struct sock *sk, int len, char __user *optval, int __user *optlen)
 {
     /* Applicable to UDP-style socket only */
     if (sctp_style(sk, TCP))
         return -EOPNOTSUPP;
     if (len < sizeof(int))
         return -EINVAL;
     len = sizeof(int);
     if (put_user(len, optlen))
         return -EFAULT;
     if (put_user(sctp_sk(sk)->autoclose, (int __user *)optval))
         return -EFAULT;
     return 0;
 }
 
 /* Helper routine to branch off an association to a new socket.  */
 int sctp_do_peeloff(struct sock *sk, sctp_assoc_t id, struct socket **sockp)
 {
     struct sctp_association *asoc = sctp_id2assoc(sk, id);
     struct sctp_sock *sp = sctp_sk(sk);
     struct socket *sock;
     int err = 0;
 
     /* Do not peel off from one netns to another one. */
     if (!net_eq(current->nsproxy->net_ns, sock_net(sk)))
         return -EINVAL;
 
     if (!asoc)
         return -EINVAL;
 
     /* An association cannot be branched off from an already peeled-off
      * socket, nor is this supported for tcp style sockets.
      */
     if (!sctp_style(sk, UDP))
         return -EINVAL;
 
     /* Create a new socket.  */
     err = sock_create(sk->sk_family, SOCK_SEQPACKET, IPPROTO_SCTP, &sock);
     if (err < 0)
         return err;
 
     sctp_copy_sock(sock->sk, sk, asoc);
 
     /* Make peeled-off sockets more like 1-1 accepted sockets.
      * Set the daddr and initialize id to something more random and also
      * copy over any ip options.
      */
     sp->pf->to_sk_daddr(&asoc->peer.primary_addr, sock->sk);
     sp->pf->copy_ip_options(sk, sock->sk);
 
     /* Populate the fields of the newsk from the oldsk and migrate the
      * asoc to the newsk.
      */
     err = sctp_sock_migrate(sk, sock->sk, asoc,
                 SCTP_SOCKET_UDP_HIGH_BANDWIDTH);
     if (err) {
         sock_release(sock);
         sock = NULL;
     }
 
     *sockp = sock;
 
     return err;
 }
 EXPORT_SYMBOL(sctp_do_peeloff);
 
 static int sctp_getsockopt_peeloff_common(struct sock *sk, sctp_peeloff_arg_t *peeloff,
                       struct file **newfile, unsigned flags)
 {
     struct socket *newsock;
     int retval;
 
     retval = sctp_do_peeloff(sk, peeloff->associd, &newsock);
     if (retval < 0)
         goto out;
 
     /* Map the socket to an unused fd that can be returned to the user.  */
     retval = get_unused_fd_flags(flags & SOCK_CLOEXEC);
     if (retval < 0) {
         sock_release(newsock);
         goto out;
     }
 
     *newfile = sock_alloc_file(newsock, 0, NULL);
     if (IS_ERR(*newfile)) {
         put_unused_fd(retval);
         retval = PTR_ERR(*newfile);
         *newfile = NULL;
         return retval;
     }
 
     pr_debug("%s: sk:%p, newsk:%p, sd:%d\n", __func__, sk, newsock->sk,
          retval);
 
     peeloff->sd = retval;
 
     if (flags & SOCK_NONBLOCK)
         (*newfile)->f_flags |= O_NONBLOCK;
 out:
     return retval;
 }
 
 static int sctp_getsockopt_peeloff(struct sock *sk, int len, char __user *optval, int __user *optlen)
 {
     sctp_peeloff_arg_t peeloff;
     struct file *newfile = NULL;
     int retval = 0;
 
     if (len < sizeof(sctp_peeloff_arg_t))
         return -EINVAL;
     len = sizeof(sctp_peeloff_arg_t);
     if (copy_from_user(&peeloff, optval, len))
         return -EFAULT;
 
     retval = sctp_getsockopt_peeloff_common(sk, &peeloff, &newfile, 0);
     if (retval < 0)
         goto out;
 
     /* Return the fd mapped to the new socket.  */
     if (put_user(len, optlen)) {
         fput(newfile);
         put_unused_fd(retval);
         return -EFAULT;
     }
 
     if (copy_to_user(optval, &peeloff, len)) {
         fput(newfile);
         put_unused_fd(retval);
         return -EFAULT;
     }
     fd_install(retval, newfile);
 out:
     return retval;
 }
 
 static int sctp_getsockopt_peeloff_flags(struct sock *sk, int len,
                      char __user *optval, int __user *optlen)
 {
     sctp_peeloff_flags_arg_t peeloff;
     struct file *newfile = NULL;
     int retval = 0;
 
     if (len < sizeof(sctp_peeloff_flags_arg_t))
         return -EINVAL;
     len = sizeof(sctp_peeloff_flags_arg_t);
     if (copy_from_user(&peeloff, optval, len))
         return -EFAULT;
 
     retval = sctp_getsockopt_peeloff_common(sk, &peeloff.p_arg,
                         &newfile, peeloff.flags);
     if (retval < 0)
         goto out;
 
     /* Return the fd mapped to the new socket.  */
     if (put_user(len, optlen)) {
         fput(newfile);
         put_unused_fd(retval);
         return -EFAULT;
     }
 
     if (copy_to_user(optval, &peeloff, len)) {
         fput(newfile);
         put_unused_fd(retval);
         return -EFAULT;
     }
     fd_install(retval, newfile);
 out:
     return retval;
 }
 
 /* 7.1.13 Peer Address Parameters (SCTP_PEER_ADDR_PARAMS)
  *
  * Applications can enable or disable heartbeats for any peer address of
  * an association, modify an address's heartbeat interval, force a
  * heartbeat to be sent immediately, and adjust the address's maximum
  * number of retransmissions sent before an address is considered
  * unreachable.  The following structure is used to access and modify an
  * address's parameters:
  *
  *  struct sctp_paddrparams {
  *     sctp_assoc_t            spp_assoc_id;
  *     struct sockaddr_storage spp_address;
  *     uint32_t                spp_hbinterval;
  *     uint16_t                spp_pathmaxrxt;
  *     uint32_t                spp_pathmtu;
  *     uint32_t                spp_sackdelay;
  *     uint32_t                spp_flags;
  * };
  *
  *   spp_assoc_id    - (one-to-many style socket) This is filled in the
  *                     application, and identifies the association for
  *                     this query.
  *   spp_address     - This specifies which address is of interest.
  *   spp_hbinterval  - This contains the value of the heartbeat interval,
  *                     in milliseconds.  If a  value of zero
  *                     is present in this field then no changes are to
  *                     be made to this parameter.
  *   spp_pathmaxrxt  - This contains the maximum number of
  *                     retransmissions before this address shall be
  *                     considered unreachable. If a  value of zero
  *                     is present in this field then no changes are to
  *                     be made to this parameter.
  *   spp_pathmtu     - When Path MTU discovery is disabled the value
  *                     specified here will be the "fixed" path mtu.
  *                     Note that if the spp_address field is empty
  *                     then all associations on this address will
  *                     have this fixed path mtu set upon them.
  *
  *   spp_sackdelay   - When delayed sack is enabled, this value specifies
  *                     the number of milliseconds that sacks will be delayed
  *                     for. This value will apply to all addresses of an
  *                     association if the spp_address field is empty. Note
  *                     also, that if delayed sack is enabled and this
  *                     value is set to 0, no change is made to the last
  *                     recorded delayed sack timer value.
  *
  *   spp_flags       - These flags are used to control various features
  *                     on an association. The flag field may contain
  *                     zero or more of the following options.
  *
  *                     SPP_HB_ENABLE  - Enable heartbeats on the
  *                     specified address. Note that if the address
  *                     field is empty all addresses for the association
  *                     have heartbeats enabled upon them.
  *
  *                     SPP_HB_DISABLE - Disable heartbeats on the
  *                     speicifed address. Note that if the address
  *                     field is empty all addresses for the association
  *                     will have their heartbeats disabled. Note also
  *                     that SPP_HB_ENABLE and SPP_HB_DISABLE are
  *                     mutually exclusive, only one of these two should
  *                     be specified. Enabling both fields will have
  *                     undetermined results.
  *
  *                     SPP_HB_DEMAND - Request a user initiated heartbeat
  *                     to be made immediately.
  *
  *                     SPP_PMTUD_ENABLE - This field will enable PMTU
  *                     discovery upon the specified address. Note that
  *                     if the address feild is empty then all addresses
  *                     on the association are effected.
  *
  *                     SPP_PMTUD_DISABLE - This field will disable PMTU
  *                     discovery upon the specified address. Note that
  *                     if the address feild is empty then all addresses
  *                     on the association are effected. Not also that
  *                     SPP_PMTUD_ENABLE and SPP_PMTUD_DISABLE are mutually
  *                     exclusive. Enabling both will have undetermined
  *                     results.
  *
  *                     SPP_SACKDELAY_ENABLE - Setting this flag turns
  *                     on delayed sack. The time specified in spp_sackdelay
  *                     is used to specify the sack delay for this address. Note
  *                     that if spp_address is empty then all addresses will
  *                     enable delayed sack and take on the sack delay
  *                     value specified in spp_sackdelay.
  *                     SPP_SACKDELAY_DISABLE - Setting this flag turns
  *                     off delayed sack. If the spp_address field is blank then
  *                     delayed sack is disabled for the entire association. Note
  *                     also that this field is mutually exclusive to
  *                     SPP_SACKDELAY_ENABLE, setting both will have undefined
  *                     results.
  *
  *                     SPP_IPV6_FLOWLABEL:  Setting this flag enables the
  *                     setting of the IPV6 flow label value.  The value is
  *                     contained in the spp_ipv6_flowlabel field.
  *                     Upon retrieval, this flag will be set to indicate that
  *                     the spp_ipv6_flowlabel field has a valid value returned.
  *                     If a specific destination address is set (in the
  *                     spp_address field), then the value returned is that of
  *                     the address.  If just an association is specified (and
  *                     no address), then the association's default flow label
  *                     is returned.  If neither an association nor a destination
  *                     is specified, then the socket's default flow label is
  *                     returned.  For non-IPv6 sockets, this flag will be left
  *                     cleared.
  *
  *                     SPP_DSCP:  Setting this flag enables the setting of the
  *                     Differentiated Services Code Point (DSCP) value
  *                     associated with either the association or a specific
  *                     address.  The value is obtained in the spp_dscp field.
  *                     Upon retrieval, this flag will be set to indicate that
  *                     the spp_dscp field has a valid value returned.  If a
  *                     specific destination address is set when called (in the
  *                     spp_address field), then that specific destination
  *                     address's DSCP value is returned.  If just an association
  *                     is specified, then the association's default DSCP is
  *                     returned.  If neither an association nor a destination is
  *                     specified, then the socket's default DSCP is returned.
  *
  *   spp_ipv6_flowlabel
  *                   - This field is used in conjunction with the
  *                     SPP_IPV6_FLOWLABEL flag and contains the IPv6 flow label.
  *                     The 20 least significant bits are used for the flow
  *                     label.  This setting has precedence over any IPv6-layer
  *                     setting.
  *
  *   spp_dscp        - This field is used in conjunction with the SPP_DSCP flag
  *                     and contains the DSCP.  The 6 most significant bits are
  *                     used for the DSCP.  This setting has precedence over any
  *                     IPv4- or IPv6- layer setting.
  */
 static int sctp_getsockopt_peer_addr_params(struct sock *sk, int len,
                         char __user *optval, int __user *optlen)
 {
     struct sctp_paddrparams  params;
     struct sctp_transport   *trans = NULL;
     struct sctp_association *asoc = NULL;
     struct sctp_sock        *sp = sctp_sk(sk);
 
     if (len >= sizeof(params))
         len = sizeof(params);
     else if (len >= ALIGN(offsetof(struct sctp_paddrparams,
                        spp_ipv6_flowlabel), 4))
         len = ALIGN(offsetof(struct sctp_paddrparams,
                      spp_ipv6_flowlabel), 4);
     else
         return -EINVAL;
 
     if (copy_from_user(&params, optval, len))
         return -EFAULT;
 
     /* If an address other than INADDR_ANY is specified, and
      * no transport is found, then the request is invalid.
      */
     if (!sctp_is_any(sk, (union sctp_addr *)&params.spp_address)) {
         trans = sctp_addr_id2transport(sk, &params.spp_address,
                            params.spp_assoc_id);
         if (!trans) {
             pr_debug("%s: failed no transport\n", __func__);
             return -EINVAL;
         }
     }
 
     /* Get association, if assoc_id != SCTP_FUTURE_ASSOC and the
      * socket is a one to many style socket, and an association
      * was not found, then the id was invalid.
      */
     asoc = sctp_id2assoc(sk, params.spp_assoc_id);
     if (!asoc && params.spp_assoc_id != SCTP_FUTURE_ASSOC &&
         sctp_style(sk, UDP)) {
         pr_debug("%s: failed no association\n", __func__);
         return -EINVAL;
     }
 
     if (trans) {
         /* Fetch transport values. */
         params.spp_hbinterval = jiffies_to_msecs(trans->hbinterval);
         params.spp_pathmtu    = trans->pathmtu;
         params.spp_pathmaxrxt = trans->pathmaxrxt;
         params.spp_sackdelay  = jiffies_to_msecs(trans->sackdelay);
 
         /*draft-11 doesn't say what to return in spp_flags*/
         params.spp_flags      = trans->param_flags;
         if (trans->flowlabel & SCTP_FLOWLABEL_SET_MASK) {
             params.spp_ipv6_flowlabel = trans->flowlabel &
                             SCTP_FLOWLABEL_VAL_MASK;
             params.spp_flags |= SPP_IPV6_FLOWLABEL;
         }
         if (trans->dscp & SCTP_DSCP_SET_MASK) {
             params.spp_dscp = trans->dscp & SCTP_DSCP_VAL_MASK;
             params.spp_flags |= SPP_DSCP;
         }
     } else if (asoc) {
         /* Fetch association values. */
         params.spp_hbinterval = jiffies_to_msecs(asoc->hbinterval);
         params.spp_pathmtu    = asoc->pathmtu;
         params.spp_pathmaxrxt = asoc->pathmaxrxt;
         params.spp_sackdelay  = jiffies_to_msecs(asoc->sackdelay);
 
         /*draft-11 doesn't say what to return in spp_flags*/
         params.spp_flags      = asoc->param_flags;
         if (asoc->flowlabel & SCTP_FLOWLABEL_SET_MASK) {
             params.spp_ipv6_flowlabel = asoc->flowlabel &
                             SCTP_FLOWLABEL_VAL_MASK;
             params.spp_flags |= SPP_IPV6_FLOWLABEL;
         }
         if (asoc->dscp & SCTP_DSCP_SET_MASK) {
             params.spp_dscp = asoc->dscp & SCTP_DSCP_VAL_MASK;
             params.spp_flags |= SPP_DSCP;
         }
     } else {
         /* Fetch socket values. */
         params.spp_hbinterval = sp->hbinterval;
         params.spp_pathmtu    = sp->pathmtu;
         params.spp_sackdelay  = sp->sackdelay;
         params.spp_pathmaxrxt = sp->pathmaxrxt;
 
         /*draft-11 doesn't say what to return in spp_flags*/
         params.spp_flags      = sp->param_flags;
         if (sp->flowlabel & SCTP_FLOWLABEL_SET_MASK) {
             params.spp_ipv6_flowlabel = sp->flowlabel &
                             SCTP_FLOWLABEL_VAL_MASK;
             params.spp_flags |= SPP_IPV6_FLOWLABEL;
         }
         if (sp->dscp & SCTP_DSCP_SET_MASK) {
             params.spp_dscp = sp->dscp & SCTP_DSCP_VAL_MASK;
             params.spp_flags |= SPP_DSCP;
         }
     }
 
     if (copy_to_user(optval, &params, len))
         return -EFAULT;
 
     if (put_user(len, optlen))
         return -EFAULT;
 
     return 0;
 }
 
 /*
  * 7.1.23.  Get or set delayed ack timer (SCTP_DELAYED_SACK)
  *
  * This option will effect the way delayed acks are performed.  This
  * option allows you to get or set the delayed ack time, in
  * milliseconds.  It also allows changing the delayed ack frequency.
  * Changing the frequency to 1 disables the delayed sack algorithm.  If
  * the assoc_id is 0, then this sets or gets the endpoints default
  * values.  If the assoc_id field is non-zero, then the set or get
  * effects the specified association for the one to many model (the
  * assoc_id field is ignored by the one to one model).  Note that if
  * sack_delay or sack_freq are 0 when setting this option, then the
  * current values will remain unchanged.
  *
  * struct sctp_sack_info {
  *     sctp_assoc_t            sack_assoc_id;
  *     uint32_t                sack_delay;
  *     uint32_t                sack_freq;
  * };
  *
  * sack_assoc_id -  This parameter, indicates which association the user
  *    is performing an action upon.  Note that if this field's value is
  *    zero then the endpoints default value is changed (effecting future
  *    associations only).
  *
  * sack_delay -  This parameter contains the number of milliseconds that
  *    the user is requesting the delayed ACK timer be set to.  Note that
  *    this value is defined in the standard to be between 200 and 500
  *    milliseconds.
  *
  * sack_freq -  This parameter contains the number of packets that must
  *    be received before a sack is sent without waiting for the delay
  *    timer to expire.  The default value for this is 2, setting this
  *    value to 1 will disable the delayed sack algorithm.
  */
 static int sctp_getsockopt_delayed_ack(struct sock *sk, int len,
                         char __user *optval,
                         int __user *optlen)
 {
     struct sctp_sack_info    params;
     struct sctp_association *asoc = NULL;
     struct sctp_sock        *sp = sctp_sk(sk);
 
     if (len >= sizeof(struct sctp_sack_info)) {
         len = sizeof(struct sctp_sack_info);
 
         if (copy_from_user(&params, optval, len))
             return -EFAULT;
     } else if (len == sizeof(struct sctp_assoc_value)) {
         pr_warn_ratelimited(DEPRECATED
                     "%s (pid %d) "
                     "Use of struct sctp_assoc_value in delayed_ack socket option.\n"
                     "Use struct sctp_sack_info instead\n",
                     current->comm, task_pid_nr(current));
         if (copy_from_user(&params, optval, len))
             return -EFAULT;
     } else
         return -EINVAL;
 
     /* Get association, if sack_assoc_id != SCTP_FUTURE_ASSOC and the
      * socket is a one to many style socket, and an association
      * was not found, then the id was invalid.
      */
     asoc = sctp_id2assoc(sk, params.sack_assoc_id);
     if (!asoc && params.sack_assoc_id != SCTP_FUTURE_ASSOC &&
         sctp_style(sk, UDP))
         return -EINVAL;
 
     if (asoc) {
         /* Fetch association values. */
         if (asoc->param_flags & SPP_SACKDELAY_ENABLE) {
             params.sack_delay = jiffies_to_msecs(asoc->sackdelay);
             params.sack_freq = asoc->sackfreq;
 
         } else {
             params.sack_delay = 0;
             params.sack_freq = 1;
         }
     } else {
         /* Fetch socket values. */
         if (sp->param_flags & SPP_SACKDELAY_ENABLE) {
             params.sack_delay  = sp->sackdelay;
             params.sack_freq = sp->sackfreq;
         } else {
             params.sack_delay  = 0;
             params.sack_freq = 1;
         }
     }
 
     if (copy_to_user(optval, &params, len))
         return -EFAULT;
 
     if (put_user(len, optlen))
         return -EFAULT;
 
     return 0;
 }
 
 /* 7.1.3 Initialization Parameters (SCTP_INITMSG)
  *
  * Applications can specify protocol parameters for the default association
  * initialization.  The option name argument to setsockopt() and getsockopt()
  * is SCTP_INITMSG.
  *
  * Setting initialization parameters is effective only on an unconnected
  * socket (for UDP-style sockets only future associations are effected
  * by the change).  With TCP-style sockets, this option is inherited by
  * sockets derived from a listener socket.
  */
 static int sctp_getsockopt_initmsg(struct sock *sk, int len, char __user *optval, int __user *optlen)
 {
     if (len < sizeof(struct sctp_initmsg))
         return -EINVAL;
     len = sizeof(struct sctp_initmsg);
     if (put_user(len, optlen))
         return -EFAULT;
     if (copy_to_user(optval, &sctp_sk(sk)->initmsg, len))
         return -EFAULT;
     return 0;
 }
 
 
 static int sctp_getsockopt_peer_addrs(struct sock *sk, int len,
                       char __user *optval, int __user *optlen)
 {
     struct sctp_association *asoc;
     int cnt = 0;
     struct sctp_getaddrs getaddrs;
     struct sctp_transport *from;
     void __user *to;
     union sctp_addr temp;
     struct sctp_sock *sp = sctp_sk(sk);
     int addrlen;
     size_t space_left;
     int bytes_copied;
 
     if (len < sizeof(struct sctp_getaddrs))
         return -EINVAL;
 
     if (copy_from_user(&getaddrs, optval, sizeof(struct sctp_getaddrs)))
         return -EFAULT;
 
     /* For UDP-style sockets, id specifies the association to query.  */
     asoc = sctp_id2assoc(sk, getaddrs.assoc_id);
     if (!asoc)
         return -EINVAL;
 
     to = optval + offsetof(struct sctp_getaddrs, addrs);
     space_left = len - offsetof(struct sctp_getaddrs, addrs);
 
     list_for_each_entry(from, &asoc->peer.transport_addr_list,
                 transports) {
         memcpy(&temp, &from->ipaddr, sizeof(temp));
         addrlen = sctp_get_pf_specific(sk->sk_family)
                   ->addr_to_user(sp, &temp);
         if (space_left < addrlen)
             return -ENOMEM;
         if (copy_to_user(to, &temp, addrlen))
             return -EFAULT;
         to += addrlen;
         cnt++;
         space_left -= addrlen;
     }
 
     if (put_user(cnt, &((struct sctp_getaddrs __user *)optval)->addr_num))
         return -EFAULT;
     bytes_copied = ((char __user *)to) - optval;
     if (put_user(bytes_copied, optlen))
         return -EFAULT;
 
     return 0;
 }
 
 static int sctp_copy_laddrs(struct sock *sk, __u16 port, void *to,
                 size_t space_left, int *bytes_copied)
 {
     struct sctp_sockaddr_entry *addr;
     union sctp_addr temp;
     int cnt = 0;
     int addrlen;
     struct net *net = sock_net(sk);
 
     rcu_read_lock();
     list_for_each_entry_rcu(addr, &net->sctp.local_addr_list, list) {
         if (!addr->valid)
             continue;
 
         if ((PF_INET == sk->sk_family) &&
             (AF_INET6 == addr->a.sa.sa_family))
             continue;
         if ((PF_INET6 == sk->sk_family) &&
             inet_v6_ipv6only(sk) &&
             (AF_INET == addr->a.sa.sa_family))
             continue;
         memcpy(&temp, &addr->a, sizeof(temp));
         if (!temp.v4.sin_port)
             temp.v4.sin_port = htons(port);
 
         addrlen = sctp_get_pf_specific(sk->sk_family)
                   ->addr_to_user(sctp_sk(sk), &temp);
 
         if (space_left < addrlen) {
             cnt =  -ENOMEM;
             break;
         }
         memcpy(to, &temp, addrlen);
 
         to += addrlen;
         cnt++;
         space_left -= addrlen;
         *bytes_copied += addrlen;
     }
     rcu_read_unlock();
 
     return cnt;
 }
 
 
 static int sctp_getsockopt_local_addrs(struct sock *sk, int len,
                        char __user *optval, int __user *optlen)
 {
     struct sctp_bind_addr *bp;
     struct sctp_association *asoc;
     int cnt = 0;
     struct sctp_getaddrs getaddrs;
     struct sctp_sockaddr_entry *addr;
     void __user *to;
     union sctp_addr temp;
     struct sctp_sock *sp = sctp_sk(sk);
     int addrlen;
     int err = 0;
     size_t space_left;
     int bytes_copied = 0;
     void *addrs;
     void *buf;
 
     if (len < sizeof(struct sctp_getaddrs))
         return -EINVAL;
 
     if (copy_from_user(&getaddrs, optval, sizeof(struct sctp_getaddrs)))
         return -EFAULT;
 
     /*
      *  For UDP-style sockets, id specifies the association to query.
      *  If the id field is set to the value '0' then the locally bound
      *  addresses are returned without regard to any particular
      *  association.
      */
     if (0 == getaddrs.assoc_id) {
         bp = &sctp_sk(sk)->ep->base.bind_addr;
     } else {
         asoc = sctp_id2assoc(sk, getaddrs.assoc_id);
         if (!asoc)
             return -EINVAL;
         bp = &asoc->base.bind_addr;
     }
 
     to = optval + offsetof(struct sctp_getaddrs, addrs);
     space_left = len - offsetof(struct sctp_getaddrs, addrs);
 
     addrs = kmalloc(space_left, GFP_USER | __GFP_NOWARN);
     if (!addrs)
         return -ENOMEM;
 
     /* If the endpoint is bound to 0.0.0.0 or ::0, get the valid
      * addresses from the global local address list.
      */
     if (sctp_list_single_entry(&bp->address_list)) {
         addr = list_entry(bp->address_list.next,
                   struct sctp_sockaddr_entry, list);
         if (sctp_is_any(sk, &addr->a)) {
             cnt = sctp_copy_laddrs(sk, bp->port, addrs,
                         space_left, &bytes_copied);
             if (cnt < 0) {
                 err = cnt;
                 goto out;
             }
             goto copy_getaddrs;
         }
     }
 
     buf = addrs;
     /* Protection on the bound address list is not needed since
      * in the socket option context we hold a socket lock and
      * thus the bound address list can't change.
      */
     list_for_each_entry(addr, &bp->address_list, list) {
         memcpy(&temp, &addr->a, sizeof(temp));
         addrlen = sctp_get_pf_specific(sk->sk_family)
                   ->addr_to_user(sp, &temp);
         if (space_left < addrlen) {
             err =  -ENOMEM; /*fixme: right error?*/
             goto out;
         }
         memcpy(buf, &temp, addrlen);
         buf += addrlen;
         bytes_copied += addrlen;
         cnt++;
         space_left -= addrlen;
     }
 
 copy_getaddrs:
     if (copy_to_user(to, addrs, bytes_copied)) {
         err = -EFAULT;
         goto out;
     }
     if (put_user(cnt, &((struct sctp_getaddrs __user *)optval)->addr_num)) {
         err = -EFAULT;
         goto out;
     }
     /* XXX: We should have accounted for sizeof(struct sctp_getaddrs) too,
      * but we can't change it anymore.
      */
     if (put_user(bytes_copied, optlen))
         err = -EFAULT;
 out:
     kfree(addrs);
     return err;
 }
 
 /* 7.1.10 Set Primary Address (SCTP_PRIMARY_ADDR)
  *
  * Requests that the local SCTP stack use the enclosed peer address as
  * the association primary.  The enclosed address must be one of the
  * association peer's addresses.
  */
 static int sctp_getsockopt_primary_addr(struct sock *sk, int len,
                     char __user *optval, int __user *optlen)
 {
     struct sctp_prim prim;
     struct sctp_association *asoc;
     struct sctp_sock *sp = sctp_sk(sk);
 
     if (len < sizeof(struct sctp_prim))
         return -EINVAL;
 
     len = sizeof(struct sctp_prim);
 
     if (copy_from_user(&prim, optval, len))
         return -EFAULT;
 
     asoc = sctp_id2assoc(sk, prim.ssp_assoc_id);
     if (!asoc)
         return -EINVAL;
 
     if (!asoc->peer.primary_path)
         return -ENOTCONN;
 
     memcpy(&prim.ssp_addr, &asoc->peer.primary_path->ipaddr,
         asoc->peer.primary_path->af_specific->sockaddr_len);
 
     sctp_get_pf_specific(sk->sk_family)->addr_to_user(sp,
             (union sctp_addr *)&prim.ssp_addr);
 
     if (put_user(len, optlen))
         return -EFAULT;
     if (copy_to_user(optval, &prim, len))
         return -EFAULT;
 
     return 0;
 }
 
 /*
  * 7.1.11  Set Adaptation Layer Indicator (SCTP_ADAPTATION_LAYER)
  *
  * Requests that the local endpoint set the specified Adaptation Layer
  * Indication parameter for all future INIT and INIT-ACK exchanges.
  */
 static int sctp_getsockopt_adaptation_layer(struct sock *sk, int len,
                   char __user *optval, int __user *optlen)
 {
     struct sctp_setadaptation adaptation;
 
     if (len < sizeof(struct sctp_setadaptation))
         return -EINVAL;
 
     len = sizeof(struct sctp_setadaptation);
 
     adaptation.ssb_adaptation_ind = sctp_sk(sk)->adaptation_ind;
 
     if (put_user(len, optlen))
         return -EFAULT;
     if (copy_to_user(optval, &adaptation, len))
         return -EFAULT;
 
     return 0;
 }
 
 /*
  *
  * 7.1.14 Set default send parameters (SCTP_DEFAULT_SEND_PARAM)
  *
  *   Applications that wish to use the sendto() system call may wish to
  *   specify a default set of parameters that would normally be supplied
  *   through the inclusion of ancillary data.  This socket option allows
  *   such an application to set the default sctp_sndrcvinfo structure.
 
 
  *   The application that wishes to use this socket option simply passes
  *   in to this call the sctp_sndrcvinfo structure defined in Section
  *   5.2.2) The input parameters accepted by this call include
  *   sinfo_stream, sinfo_flags, sinfo_ppid, sinfo_context,
  *   sinfo_timetolive.  The user must provide the sinfo_assoc_id field in
  *   to this call if the caller is using the UDP model.
  *
  *   For getsockopt, it get the default sctp_sndrcvinfo structure.
  */
 static int sctp_getsockopt_default_send_param(struct sock *sk,
                     int len, char __user *optval,
                     int __user *optlen)
 {
     struct sctp_sock *sp = sctp_sk(sk);
     struct sctp_association *asoc;
     struct sctp_sndrcvinfo info;
 
     if (len < sizeof(info))
         return -EINVAL;
 
     len = sizeof(info);
 
     if (copy_from_user(&info, optval, len))
         return -EFAULT;
 
     asoc = sctp_id2assoc(sk, info.sinfo_assoc_id);
     if (!asoc && info.sinfo_assoc_id != SCTP_FUTURE_ASSOC &&
         sctp_style(sk, UDP))
         return -EINVAL;
 
     if (asoc) {
         info.sinfo_stream = asoc->default_stream;
         info.sinfo_flags = asoc->default_flags;
         info.sinfo_ppid = asoc->default_ppid;
         info.sinfo_context = asoc->default_context;
         info.sinfo_timetolive = asoc->default_timetolive;
     } else {
         info.sinfo_stream = sp->default_stream;
         info.sinfo_flags = sp->default_flags;
         info.sinfo_ppid = sp->default_ppid;
         info.sinfo_context = sp->default_context;
         info.sinfo_timetolive = sp->default_timetolive;
     }
 
     if (put_user(len, optlen))
         return -EFAULT;
     if (copy_to_user(optval, &info, len))
         return -EFAULT;
 
     return 0;
 }
 
 /* RFC6458, Section 8.1.31. Set/get Default Send Parameters
  * (SCTP_DEFAULT_SNDINFO)
  */
 static int sctp_getsockopt_default_sndinfo(struct sock *sk, int len,
                        char __user *optval,
                        int __user *optlen)
 {
     struct sctp_sock *sp = sctp_sk(sk);
     struct sctp_association *asoc;
     struct sctp_sndinfo info;
 
     if (len < sizeof(info))
         return -EINVAL;
 
     len = sizeof(info);
 
     if (copy_from_user(&info, optval, len))
         return -EFAULT;
 
     asoc = sctp_id2assoc(sk, info.snd_assoc_id);
     if (!asoc && info.snd_assoc_id != SCTP_FUTURE_ASSOC &&
         sctp_style(sk, UDP))
         return -EINVAL;
 
     if (asoc) {
         info.snd_sid = asoc->default_stream;
         info.snd_flags = asoc->default_flags;
         info.snd_ppid = asoc->default_ppid;
         info.snd_context = asoc->default_context;
     } else {
         info.snd_sid = sp->default_stream;
         info.snd_flags = sp->default_flags;
         info.snd_ppid = sp->default_ppid;
         info.snd_context = sp->default_context;
     }
 
     if (put_user(len, optlen))
         return -EFAULT;
     if (copy_to_user(optval, &info, len))
         return -EFAULT;
 
     return 0;
 }
 
 /*
  *
  * 7.1.5 SCTP_NODELAY
  *
  * Turn on/off any Nagle-like algorithm.  This means that packets are
  * generally sent as soon as possible and no unnecessary delays are
  * introduced, at the cost of more packets in the network.  Expects an
  * integer boolean flag.
  */
 
 static int sctp_getsockopt_nodelay(struct sock *sk, int len,
                    char __user *optval, int __user *optlen)
 {
     int val;
 
     if (len < sizeof(int))
         return -EINVAL;
 
     len = sizeof(int);
     val = (sctp_sk(sk)->nodelay == 1);
     if (put_user(len, optlen))
         return -EFAULT;
     if (copy_to_user(optval, &val, len))
         return -EFAULT;
     return 0;
 }
 
 /*
  *
  * 7.1.1 SCTP_RTOINFO
  *
  * The protocol parameters used to initialize and bound retransmission
  * timeout (RTO) are tunable. sctp_rtoinfo structure is used to access
  * and modify these parameters.
  * All parameters are time values, in milliseconds.  A value of 0, when
  * modifying the parameters, indicates that the current value should not
  * be changed.
  *
  */
 static int sctp_getsockopt_rtoinfo(struct sock *sk, int len,
                 char __user *optval,
                 int __user *optlen) {
     struct sctp_rtoinfo rtoinfo;
     struct sctp_association *asoc;
 
     if (len < sizeof (struct sctp_rtoinfo))
         return -EINVAL;
 
     len = sizeof(struct sctp_rtoinfo);
 
     if (copy_from_user(&rtoinfo, optval, len))
         return -EFAULT;
 
     asoc = sctp_id2assoc(sk, rtoinfo.srto_assoc_id);
 
     if (!asoc && rtoinfo.srto_assoc_id != SCTP_FUTURE_ASSOC &&
         sctp_style(sk, UDP))
         return -EINVAL;
 
     /* Values corresponding to the specific association. */
     if (asoc) {
         rtoinfo.srto_initial = jiffies_to_msecs(asoc->rto_initial);
         rtoinfo.srto_max = jiffies_to_msecs(asoc->rto_max);
         rtoinfo.srto_min = jiffies_to_msecs(asoc->rto_min);
     } else {
         /* Values corresponding to the endpoint. */
         struct sctp_sock *sp = sctp_sk(sk);
 
         rtoinfo.srto_initial = sp->rtoinfo.srto_initial;
         rtoinfo.srto_max = sp->rtoinfo.srto_max;
         rtoinfo.srto_min = sp->rtoinfo.srto_min;
     }
 
     if (put_user(len, optlen))
         return -EFAULT;
 
     if (copy_to_user(optval, &rtoinfo, len))
         return -EFAULT;
 
     return 0;
 }
 
 /*
  *
  * 7.1.2 SCTP_ASSOCINFO
  *
  * This option is used to tune the maximum retransmission attempts
  * of the association.
  * Returns an error if the new association retransmission value is
  * greater than the sum of the retransmission value  of the peer.
  * See [SCTP] for more information.
  *
  */
 static int sctp_getsockopt_associnfo(struct sock *sk, int len,
                      char __user *optval,
                      int __user *optlen)
 {
 
     struct sctp_assocparams assocparams;
     struct sctp_association *asoc;
     struct list_head *pos;
     int cnt = 0;
 
     if (len < sizeof (struct sctp_assocparams))
         return -EINVAL;
 
     len = sizeof(struct sctp_assocparams);
 
     if (copy_from_user(&assocparams, optval, len))
         return -EFAULT;
 
     asoc = sctp_id2assoc(sk, assocparams.sasoc_assoc_id);
 
     if (!asoc && assocparams.sasoc_assoc_id != SCTP_FUTURE_ASSOC &&
         sctp_style(sk, UDP))
         return -EINVAL;
 
     /* Values correspoinding to the specific association */
     if (asoc) {
         assocparams.sasoc_asocmaxrxt = asoc->max_retrans;
         assocparams.sasoc_peer_rwnd = asoc->peer.rwnd;
         assocparams.sasoc_local_rwnd = asoc->a_rwnd;
         assocparams.sasoc_cookie_life = ktime_to_ms(asoc->cookie_life);
 
         list_for_each(pos, &asoc->peer.transport_addr_list) {
             cnt++;
         }
 
         assocparams.sasoc_number_peer_destinations = cnt;
     } else {
         /* Values corresponding to the endpoint */
         struct sctp_sock *sp = sctp_sk(sk);
 
         assocparams.sasoc_asocmaxrxt = sp->assocparams.sasoc_asocmaxrxt;
         assocparams.sasoc_peer_rwnd = sp->assocparams.sasoc_peer_rwnd;
         assocparams.sasoc_local_rwnd = sp->assocparams.sasoc_local_rwnd;
         assocparams.sasoc_cookie_life =
                     sp->assocparams.sasoc_cookie_life;
         assocparams.sasoc_number_peer_destinations =
                     sp->assocparams.
                     sasoc_number_peer_destinations;
     }
 
     if (put_user(len, optlen))
         return -EFAULT;
 
     if (copy_to_user(optval, &assocparams, len))
         return -EFAULT;
 
     return 0;
 }
 
 /*
  * 7.1.16 Set/clear IPv4 mapped addresses (SCTP_I_WANT_MAPPED_V4_ADDR)
  *
  * This socket option is a boolean flag which turns on or off mapped V4
  * addresses.  If this option is turned on and the socket is type
  * PF_INET6, then IPv4 addresses will be mapped to V6 representation.
  * If this option is turned off, then no mapping will be done of V4
  * addresses and a user will receive both PF_INET6 and PF_INET type
  * addresses on the socket.
  */
 static int sctp_getsockopt_mappedv4(struct sock *sk, int len,
                     char __user *optval, int __user *optlen)
 {
     int val;
     struct sctp_sock *sp = sctp_sk(sk);
 
     if (len < sizeof(int))
         return -EINVAL;
 
     len = sizeof(int);
     val = sp->v4mapped;
     if (put_user(len, optlen))
         return -EFAULT;
     if (copy_to_user(optval, &val, len))
         return -EFAULT;
 
     return 0;
 }
 
 /*
  * 7.1.29.  Set or Get the default context (SCTP_CONTEXT)
  * (chapter and verse is quoted at sctp_setsockopt_context())
  */
 static int sctp_getsockopt_context(struct sock *sk, int len,
                    char __user *optval, int __user *optlen)
 {
     struct sctp_assoc_value params;
     struct sctp_association *asoc;
 
     if (len < sizeof(struct sctp_assoc_value))
         return -EINVAL;
 
     len = sizeof(struct sctp_assoc_value);
 
     if (copy_from_user(&params, optval, len))
         return -EFAULT;
 
     asoc = sctp_id2assoc(sk, params.assoc_id);
     if (!asoc && params.assoc_id != SCTP_FUTURE_ASSOC &&
         sctp_style(sk, UDP))
         return -EINVAL;
 
     params.assoc_value = asoc ? asoc->default_rcv_context
                   : sctp_sk(sk)->default_rcv_context;
 
     if (put_user(len, optlen))
         return -EFAULT;
     if (copy_to_user(optval, &params, len))
         return -EFAULT;
 
     return 0;
 }
 
 /*
  * 8.1.16.  Get or Set the Maximum Fragmentation Size (SCTP_MAXSEG)
  * This option will get or set the maximum size to put in any outgoing
  * SCTP DATA chunk.  If a message is larger than this size it will be
  * fragmented by SCTP into the specified size.  Note that the underlying
  * SCTP implementation may fragment into smaller sized chunks when the
  * PMTU of the underlying association is smaller than the value set by
  * the user.  The default value for this option is '0' which indicates
  * the user is NOT limiting fragmentation and only the PMTU will effect
  * SCTP's choice of DATA chunk size.  Note also that values set larger
  * than the maximum size of an IP datagram will effectively let SCTP
  * control fragmentation (i.e. the same as setting this option to 0).
  *
  * The following structure is used to access and modify this parameter:
  *
  * struct sctp_assoc_value {
  *   sctp_assoc_t assoc_id;
  *   uint32_t assoc_value;
  * };
  *
  * assoc_id:  This parameter is ignored for one-to-one style sockets.
  *    For one-to-many style sockets this parameter indicates which
  *    association the user is performing an action upon.  Note that if
  *    this field's value is zero then the endpoints default value is
  *    changed (effecting future associations only).
  * assoc_value:  This parameter specifies the maximum size in bytes.
  */
 static int sctp_getsockopt_maxseg(struct sock *sk, int len,
                   char __user *optval, int __user *optlen)
 {
     struct sctp_assoc_value params;
     struct sctp_association *asoc;
 
     if (len == sizeof(int)) {
         pr_warn_ratelimited(DEPRECATED
                     "%s (pid %d) "
                     "Use of int in maxseg socket option.\n"
                     "Use struct sctp_assoc_value instead\n",
                     current->comm, task_pid_nr(current));
         params.assoc_id = SCTP_FUTURE_ASSOC;
     } else if (len >= sizeof(struct sctp_assoc_value)) {
         len = sizeof(struct sctp_assoc_value);
         if (copy_from_user(&params, optval, len))
             return -EFAULT;
     } else
         return -EINVAL;
 
     asoc = sctp_id2assoc(sk, params.assoc_id);
     if (!asoc && params.assoc_id != SCTP_FUTURE_ASSOC &&
         sctp_style(sk, UDP))
         return -EINVAL;
 
     if (asoc)
         params.assoc_value = asoc->frag_point;
     else
         params.assoc_value = sctp_sk(sk)->user_frag;
 
     if (put_user(len, optlen))
         return -EFAULT;
     if (len == sizeof(int)) {
         if (copy_to_user(optval, &params.assoc_value, len))
             return -EFAULT;
     } else {
         if (copy_to_user(optval, &params, len))
             return -EFAULT;
     }
 
     return 0;
 }
 
 /*
  * 7.1.24.  Get or set fragmented interleave (SCTP_FRAGMENT_INTERLEAVE)
  * (chapter and verse is quoted at sctp_setsockopt_fragment_interleave())
  */
 static int sctp_getsockopt_fragment_interleave(struct sock *sk, int len,
                            char __user *optval, int __user *optlen)
 {
     int val;
 
     if (len < sizeof(int))
         return -EINVAL;
 
     len = sizeof(int);
 
     val = sctp_sk(sk)->frag_interleave;
     if (put_user(len, optlen))
         return -EFAULT;
     if (copy_to_user(optval, &val, len))
         return -EFAULT;
 
     return 0;
 }
 
 /*
  * 7.1.25.  Set or Get the sctp partial delivery point
  * (chapter and verse is quoted at sctp_setsockopt_partial_delivery_point())
  */
 static int sctp_getsockopt_partial_delivery_point(struct sock *sk, int len,
                           char __user *optval,
                           int __user *optlen)
 {
     u32 val;
 
     if (len < sizeof(u32))
         return -EINVAL;
 
     len = sizeof(u32);
 
     val = sctp_sk(sk)->pd_point;
     if (put_user(len, optlen))
         return -EFAULT;
     if (copy_to_user(optval, &val, len))
         return -EFAULT;
 
     return 0;
 }
 
 /*
  * 7.1.28.  Set or Get the maximum burst (SCTP_MAX_BURST)
  * (chapter and verse is quoted at sctp_setsockopt_maxburst())
  */
 static int sctp_getsockopt_maxburst(struct sock *sk, int len,
                     char __user *optval,
                     int __user *optlen)
 {
     struct sctp_assoc_value params;
     struct sctp_association *asoc;
 
     if (len == sizeof(int)) {
         pr_warn_ratelimited(DEPRECATED
                     "%s (pid %d) "
                     "Use of int in max_burst socket option.\n"
                     "Use struct sctp_assoc_value instead\n",
                     current->comm, task_pid_nr(current));
         params.assoc_id = SCTP_FUTURE_ASSOC;
     } else if (len >= sizeof(struct sctp_assoc_value)) {
         len = sizeof(struct sctp_assoc_value);
         if (copy_from_user(&params, optval, len))
             return -EFAULT;
     } else
         return -EINVAL;
 
     asoc = sctp_id2assoc(sk, params.assoc_id);
     if (!asoc && params.assoc_id != SCTP_FUTURE_ASSOC &&
         sctp_style(sk, UDP))
         return -EINVAL;
 
     params.assoc_value = asoc ? asoc->max_burst : sctp_sk(sk)->max_burst;
 
     if (len == sizeof(int)) {
         if (copy_to_user(optval, &params.assoc_value, len))
             return -EFAULT;
     } else {
         if (copy_to_user(optval, &params, len))
             return -EFAULT;
     }
 
     return 0;
 
 }
 
 static int sctp_getsockopt_hmac_ident(struct sock *sk, int len,
                     char __user *optval, int __user *optlen)
 {
     struct sctp_endpoint *ep = sctp_sk(sk)->ep;
     struct sctp_hmacalgo  __user *p = (void __user *)optval;
     struct sctp_hmac_algo_param *hmacs;
     __u16 data_len = 0;
     u32 num_idents;
     int i;
 
     if (!ep->auth_enable)
         return -EACCES;
 
     hmacs = ep->auth_hmacs_list;
     data_len = ntohs(hmacs->param_hdr.length) -
            sizeof(struct sctp_paramhdr);
 
     if (len < sizeof(struct sctp_hmacalgo) + data_len)
         return -EINVAL;
 
     len = sizeof(struct sctp_hmacalgo) + data_len;
     num_idents = data_len / sizeof(u16);
 
     if (put_user(len, optlen))
         return -EFAULT;
     if (put_user(num_idents, &p->shmac_num_idents))
         return -EFAULT;
     for (i = 0; i < num_idents; i++) {
         __u16 hmacid = ntohs(hmacs->hmac_ids[i]);
 
         if (copy_to_user(&p->shmac_idents[i], &hmacid, sizeof(__u16)))
             return -EFAULT;
     }
     return 0;
 }
 
 static int sctp_getsockopt_active_key(struct sock *sk, int len,
                     char __user *optval, int __user *optlen)
 {
     struct sctp_endpoint *ep = sctp_sk(sk)->ep;
     struct sctp_authkeyid val;
     struct sctp_association *asoc;
 
     if (len < sizeof(struct sctp_authkeyid))
         return -EINVAL;
 
     len = sizeof(struct sctp_authkeyid);
     if (copy_from_user(&val, optval, len))
         return -EFAULT;
 
     asoc = sctp_id2assoc(sk, val.scact_assoc_id);
     if (!asoc && val.scact_assoc_id && sctp_style(sk, UDP))
         return -EINVAL;
 
     if (asoc) {
         if (!asoc->peer.auth_capable)
             return -EACCES;
         val.scact_keynumber = asoc->active_key_id;
     } else {
         if (!ep->auth_enable)
             return -EACCES;
         val.scact_keynumber = ep->active_key_id;
     }
 
     if (put_user(len, optlen))
         return -EFAULT;
     if (copy_to_user(optval, &val, len))
         return -EFAULT;
 
     return 0;
 }
 
 static int sctp_getsockopt_peer_auth_chunks(struct sock *sk, int len,
                     char __user *optval, int __user *optlen)
 {
     struct sctp_authchunks __user *p = (void __user *)optval;
     struct sctp_authchunks val;
     struct sctp_association *asoc;
     struct sctp_chunks_param *ch;
     u32    num_chunks = 0;
     char __user *to;
 
     if (len < sizeof(struct sctp_authchunks))
         return -EINVAL;
 
     if (copy_from_user(&val, optval, sizeof(val)))
         return -EFAULT;
 
     to = p->gauth_chunks;
     asoc = sctp_id2assoc(sk, val.gauth_assoc_id);
     if (!asoc)
         return -EINVAL;
 
     if (!asoc->peer.auth_capable)
         return -EACCES;
 
     ch = asoc->peer.peer_chunks;
     if (!ch)
         goto num;
 
     /* See if the user provided enough room for all the data */
     num_chunks = ntohs(ch->param_hdr.length) - sizeof(struct sctp_paramhdr);
     if (len < num_chunks)
         return -EINVAL;
 
     if (copy_to_user(to, ch->chunks, num_chunks))
         return -EFAULT;
 num:
     len = sizeof(struct sctp_authchunks) + num_chunks;
     if (put_user(len, optlen))
         return -EFAULT;
     if (put_user(num_chunks, &p->gauth_number_of_chunks))
         return -EFAULT;
     return 0;
 }
 
 static int sctp_getsockopt_local_auth_chunks(struct sock *sk, int len,
                     char __user *optval, int __user *optlen)
 {
     struct sctp_endpoint *ep = sctp_sk(sk)->ep;
     struct sctp_authchunks __user *p = (void __user *)optval;
     struct sctp_authchunks val;
     struct sctp_association *asoc;
     struct sctp_chunks_param *ch;
     u32    num_chunks = 0;
     char __user *to;
 
     if (len < sizeof(struct sctp_authchunks))
         return -EINVAL;
 
     if (copy_from_user(&val, optval, sizeof(val)))
         return -EFAULT;
 
     to = p->gauth_chunks;
     asoc = sctp_id2assoc(sk, val.gauth_assoc_id);
     if (!asoc && val.gauth_assoc_id != SCTP_FUTURE_ASSOC &&
         sctp_style(sk, UDP))
         return -EINVAL;
 
     if (asoc) {
         if (!asoc->peer.auth_capable)
             return -EACCES;
         ch = (struct sctp_chunks_param *)asoc->c.auth_chunks;
     } else {
         if (!ep->auth_enable)
             return -EACCES;
         ch = ep->auth_chunk_list;
     }
     if (!ch)
         goto num;
 
     num_chunks = ntohs(ch->param_hdr.length) - sizeof(struct sctp_paramhdr);
     if (len < sizeof(struct sctp_authchunks) + num_chunks)
         return -EINVAL;
 
     if (copy_to_user(to, ch->chunks, num_chunks))
         return -EFAULT;
 num:
     len = sizeof(struct sctp_authchunks) + num_chunks;
     if (put_user(len, optlen))
         return -EFAULT;
     if (put_user(num_chunks, &p->gauth_number_of_chunks))
         return -EFAULT;
 
     return 0;
 }
 
 /*
  * 8.2.5.  Get the Current Number of Associations (SCTP_GET_ASSOC_NUMBER)
  * This option gets the current number of associations that are attached
  * to a one-to-many style socket.  The option value is an uint32_t.
  */
 static int sctp_getsockopt_assoc_number(struct sock *sk, int len,
                     char __user *optval, int __user *optlen)
 {
     struct sctp_sock *sp = sctp_sk(sk);
     struct sctp_association *asoc;
     u32 val = 0;
 
     if (sctp_style(sk, TCP))
         return -EOPNOTSUPP;
 
     if (len < sizeof(u32))
         return -EINVAL;
 
     len = sizeof(u32);
 
     list_for_each_entry(asoc, &(sp->ep->asocs), asocs) {
         val++;
     }
 
     if (put_user(len, optlen))
         return -EFAULT;
     if (copy_to_user(optval, &val, len))
         return -EFAULT;
 
     return 0;
 }
 
 /*
  * 8.1.23 SCTP_AUTO_ASCONF
  * See the corresponding setsockopt entry as description
  */
 static int sctp_getsockopt_auto_asconf(struct sock *sk, int len,
                    char __user *optval, int __user *optlen)
 {
     int val = 0;
 
     if (len < sizeof(int))
         return -EINVAL;
 
     len = sizeof(int);
     if (sctp_sk(sk)->do_auto_asconf && sctp_is_ep_boundall(sk))
         val = 1;
     if (put_user(len, optlen))
         return -EFAULT;
     if (copy_to_user(optval, &val, len))
         return -EFAULT;
     return 0;
 }
 
 /*
  * 8.2.6. Get the Current Identifiers of Associations
  *        (SCTP_GET_ASSOC_ID_LIST)
  *
  * This option gets the current list of SCTP association identifiers of
  * the SCTP associations handled by a one-to-many style socket.
  */
 static int sctp_getsockopt_assoc_ids(struct sock *sk, int len,
                     char __user *optval, int __user *optlen)
 {
     struct sctp_sock *sp = sctp_sk(sk);
     struct sctp_association *asoc;
     struct sctp_assoc_ids *ids;
     u32 num = 0;
 
     if (sctp_style(sk, TCP))
         return -EOPNOTSUPP;
 
     if (len < sizeof(struct sctp_assoc_ids))
         return -EINVAL;
 
     list_for_each_entry(asoc, &(sp->ep->asocs), asocs) {
         num++;
     }
 
     if (len < sizeof(struct sctp_assoc_ids) + sizeof(sctp_assoc_t) * num)
         return -EINVAL;
 
     len = sizeof(struct sctp_assoc_ids) + sizeof(sctp_assoc_t) * num;
 
     ids = kmalloc(len, GFP_USER | __GFP_NOWARN);
     if (unlikely(!ids))
         return -ENOMEM;
 
     ids->gaids_number_of_ids = num;
     num = 0;
     list_for_each_entry(asoc, &(sp->ep->asocs), asocs) {
         ids->gaids_assoc_id[num++] = asoc->assoc_id;
     }
 
     if (put_user(len, optlen) || copy_to_user(optval, ids, len)) {
         kfree(ids);
         return -EFAULT;
     }
 
     kfree(ids);
     return 0;
 }
 
 /*
  * SCTP_PEER_ADDR_THLDS
  *
  * This option allows us to fetch the partially failed threshold for one or all
  * transports in an association.  See Section 6.1 of:
  * http://www.ietf.org/id/draft-nishida-tsvwg-sctp-failover-05.txt
  */
 static int sctp_getsockopt_paddr_thresholds(struct sock *sk,
                         char __user *optval, int len,
                         int __user *optlen, bool v2)
 {
     struct sctp_paddrthlds_v2 val;
     struct sctp_transport *trans;
     struct sctp_association *asoc;
     int min;
 
     min = v2 ? sizeof(val) : sizeof(struct sctp_paddrthlds);
     if (len < min)
         return -EINVAL;
     len = min;
     if (copy_from_user(&val, optval, len))
         return -EFAULT;
 
     if (!sctp_is_any(sk, (const union sctp_addr *)&val.spt_address)) {
         trans = sctp_addr_id2transport(sk, &val.spt_address,
                            val.spt_assoc_id);
         if (!trans)
             return -ENOENT;
 
         val.spt_pathmaxrxt = trans->pathmaxrxt;
         val.spt_pathpfthld = trans->pf_retrans;
         val.spt_pathcpthld = trans->ps_retrans;
 
         goto out;
     }
 
     asoc = sctp_id2assoc(sk, val.spt_assoc_id);
     if (!asoc && val.spt_assoc_id != SCTP_FUTURE_ASSOC &&
         sctp_style(sk, UDP))
         return -EINVAL;
 
     if (asoc) {
         val.spt_pathpfthld = asoc->pf_retrans;
         val.spt_pathmaxrxt = asoc->pathmaxrxt;
         val.spt_pathcpthld = asoc->ps_retrans;
     } else {
         struct sctp_sock *sp = sctp_sk(sk);
 
         val.spt_pathpfthld = sp->pf_retrans;
         val.spt_pathmaxrxt = sp->pathmaxrxt;
         val.spt_pathcpthld = sp->ps_retrans;
     }
 
 out:
     if (put_user(len, optlen) || copy_to_user(optval, &val, len))
         return -EFAULT;
 
     return 0;
 }
 
 /*
  * SCTP_GET_ASSOC_STATS
  *
  * This option retrieves local per endpoint statistics. It is modeled
  * after OpenSolaris' implementation
  */
 static int sctp_getsockopt_assoc_stats(struct sock *sk, int len,
                        char __user *optval,
                        int __user *optlen)
 {
     struct sctp_assoc_stats sas;
     struct sctp_association *asoc = NULL;
 
     /* User must provide at least the assoc id */
     if (len < sizeof(sctp_assoc_t))
         return -EINVAL;
 
     /* Allow the struct to grow and fill in as much as possible */
     len = min_t(size_t, len, sizeof(sas));
 
     if (copy_from_user(&sas, optval, len))
         return -EFAULT;
 
     asoc = sctp_id2assoc(sk, sas.sas_assoc_id);
     if (!asoc)
         return -EINVAL;
 
     sas.sas_rtxchunks = asoc->stats.rtxchunks;
     sas.sas_gapcnt = asoc->stats.gapcnt;
     sas.sas_outofseqtsns = asoc->stats.outofseqtsns;
     sas.sas_osacks = asoc->stats.osacks;
     sas.sas_isacks = asoc->stats.isacks;
     sas.sas_octrlchunks = asoc->stats.octrlchunks;
     sas.sas_ictrlchunks = asoc->stats.ictrlchunks;
     sas.sas_oodchunks = asoc->stats.oodchunks;
     sas.sas_iodchunks = asoc->stats.iodchunks;
     sas.sas_ouodchunks = asoc->stats.ouodchunks;
     sas.sas_iuodchunks = asoc->stats.iuodchunks;
     sas.sas_idupchunks = asoc->stats.idupchunks;
     sas.sas_opackets = asoc->stats.opackets;
     sas.sas_ipackets = asoc->stats.ipackets;
 
     /* New high max rto observed, will return 0 if not a single
      * RTO update took place. obs_rto_ipaddr will be bogus
      * in such a case
      */
     sas.sas_maxrto = asoc->stats.max_obs_rto;
     memcpy(&sas.sas_obs_rto_ipaddr, &asoc->stats.obs_rto_ipaddr,
         sizeof(struct sockaddr_storage));
 
     /* Mark beginning of a new observation period */
     asoc->stats.max_obs_rto = asoc->rto_min;
 
     if (put_user(len, optlen))
         return -EFAULT;
 
     pr_debug("%s: len:%d, assoc_id:%d\n", __func__, len, sas.sas_assoc_id);
 
     if (copy_to_user(optval, &sas, len))
         return -EFAULT;
 
     return 0;
 }
 
 static int sctp_getsockopt_recvrcvinfo(struct sock *sk, int len,
                        char __user *optval,
                        int __user *optlen)
 {
     int val = 0;
 
     if (len < sizeof(int))
         return -EINVAL;
 
     len = sizeof(int);
     if (sctp_sk(sk)->recvrcvinfo)
         val = 1;
     if (put_user(len, optlen))
         return -EFAULT;
     if (copy_to_user(optval, &val, len))
         return -EFAULT;
 
     return 0;
 }
 
 static int sctp_getsockopt_recvnxtinfo(struct sock *sk, int len,
                        char __user *optval,
                        int __user *optlen)
 {
     int val = 0;
 
     if (len < sizeof(int))
         return -EINVAL;
 
     len = sizeof(int);
     if (sctp_sk(sk)->recvnxtinfo)
         val = 1;
     if (put_user(len, optlen))
         return -EFAULT;
     if (copy_to_user(optval, &val, len))
         return -EFAULT;
 
     return 0;
 }
 
 static int sctp_getsockopt_pr_supported(struct sock *sk, int len,
                     char __user *optval,
                     int __user *optlen)
 {
     struct sctp_assoc_value params;
     struct sctp_association *asoc;
     int retval = -EFAULT;
 
     if (len < sizeof(params)) {
         retval = -EINVAL;
         goto out;
     }
 
     len = sizeof(params);
     if (copy_from_user(&params, optval, len))
         goto out;
 
     asoc = sctp_id2assoc(sk, params.assoc_id);
     if (!asoc && params.assoc_id != SCTP_FUTURE_ASSOC &&
         sctp_style(sk, UDP)) {
         retval = -EINVAL;
         goto out;
     }
 
     params.assoc_value = asoc ? asoc->peer.prsctp_capable
                   : sctp_sk(sk)->ep->prsctp_enable;
 
     if (put_user(len, optlen))
         goto out;
 
     if (copy_to_user(optval, &params, len))
         goto out;
 
     retval = 0;
 
 out:
     return retval;
 }
 
 static int sctp_getsockopt_default_prinfo(struct sock *sk, int len,
                       char __user *optval,
                       int __user *optlen)
 {
     struct sctp_default_prinfo info;
     struct sctp_association *asoc;
     int retval = -EFAULT;
 
     if (len < sizeof(info)) {
         retval = -EINVAL;
         goto out;
     }
 
     len = sizeof(info);
     if (copy_from_user(&info, optval, len))
         goto out;
 
     asoc = sctp_id2assoc(sk, info.pr_assoc_id);
     if (!asoc && info.pr_assoc_id != SCTP_FUTURE_ASSOC &&
         sctp_style(sk, UDP)) {
         retval = -EINVAL;
         goto out;
     }
 
     if (asoc) {
         info.pr_policy = SCTP_PR_POLICY(asoc->default_flags);
         info.pr_value = asoc->default_timetolive;
     } else {
         struct sctp_sock *sp = sctp_sk(sk);
 
         info.pr_policy = SCTP_PR_POLICY(sp->default_flags);
         info.pr_value = sp->default_timetolive;
     }
 
     if (put_user(len, optlen))
         goto out;
 
     if (copy_to_user(optval, &info, len))
         goto out;
 
     retval = 0;
 
 out:
     return retval;
 }
 
 static int sctp_getsockopt_pr_assocstatus(struct sock *sk, int len,
                       char __user *optval,
                       int __user *optlen)
 {
     struct sctp_prstatus params;
     struct sctp_association *asoc;
     int policy;
     int retval = -EINVAL;
 
     if (len < sizeof(params))
         goto out;
 
     len = sizeof(params);
     if (copy_from_user(&params, optval, len)) {
         retval = -EFAULT;
         goto out;
     }
 
     policy = params.sprstat_policy;
     if (!policy || (policy & ~(SCTP_PR_SCTP_MASK | SCTP_PR_SCTP_ALL)) ||
         ((policy & SCTP_PR_SCTP_ALL) && (policy & SCTP_PR_SCTP_MASK)))
         goto out;
 
     asoc = sctp_id2assoc(sk, params.sprstat_assoc_id);
     if (!asoc)
         goto out;
 
     if (policy == SCTP_PR_SCTP_ALL) {
         params.sprstat_abandoned_unsent = 0;
         params.sprstat_abandoned_sent = 0;
         for (policy = 0; policy <= SCTP_PR_INDEX(MAX); policy++) {
             params.sprstat_abandoned_unsent +=
                 asoc->abandoned_unsent[policy];
             params.sprstat_abandoned_sent +=
                 asoc->abandoned_sent[policy];
         }
     } else {
         params.sprstat_abandoned_unsent =
             asoc->abandoned_unsent[__SCTP_PR_INDEX(policy)];
         params.sprstat_abandoned_sent =
             asoc->abandoned_sent[__SCTP_PR_INDEX(policy)];
     }
 
     if (put_user(len, optlen)) {
         retval = -EFAULT;
         goto out;
     }
 
     if (copy_to_user(optval, &params, len)) {
         retval = -EFAULT;
         goto out;
     }
 
     retval = 0;
 
 out:
     return retval;
 }
 
 static int sctp_getsockopt_pr_streamstatus(struct sock *sk, int len,
                        char __user *optval,
                        int __user *optlen)
 {
     struct sctp_stream_out_ext *streamoute;
     struct sctp_association *asoc;
     struct sctp_prstatus params;
     int retval = -EINVAL;
     int policy;
 
     if (len < sizeof(params))
         goto out;
 
     len = sizeof(params);
     if (copy_from_user(&params, optval, len)) {
         retval = -EFAULT;
         goto out;
     }
 
     policy = params.sprstat_policy;
     if (!policy || (policy & ~(SCTP_PR_SCTP_MASK | SCTP_PR_SCTP_ALL)) ||
         ((policy & SCTP_PR_SCTP_ALL) && (policy & SCTP_PR_SCTP_MASK)))
         goto out;
 
     asoc = sctp_id2assoc(sk, params.sprstat_assoc_id);
     if (!asoc || params.sprstat_sid >= asoc->stream.outcnt)
         goto out;
 
     streamoute = SCTP_SO(&asoc->stream, params.sprstat_sid)->ext;
     if (!streamoute) {
         /* Not allocated yet, means all stats are 0 */
         params.sprstat_abandoned_unsent = 0;
         params.sprstat_abandoned_sent = 0;
         retval = 0;
         goto out;
     }
 
     if (policy == SCTP_PR_SCTP_ALL) {
         params.sprstat_abandoned_unsent = 0;
         params.sprstat_abandoned_sent = 0;
         for (policy = 0; policy <= SCTP_PR_INDEX(MAX); policy++) {
             params.sprstat_abandoned_unsent +=
                 streamoute->abandoned_unsent[policy];
             params.sprstat_abandoned_sent +=
                 streamoute->abandoned_sent[policy];
         }
     } else {
         params.sprstat_abandoned_unsent =
             streamoute->abandoned_unsent[__SCTP_PR_INDEX(policy)];
         params.sprstat_abandoned_sent =
             streamoute->abandoned_sent[__SCTP_PR_INDEX(policy)];
     }
 
     if (put_user(len, optlen) || copy_to_user(optval, &params, len)) {
         retval = -EFAULT;
         goto out;
     }
 
     retval = 0;
 
 out:
     return retval;
 }
 
 static int sctp_getsockopt_reconfig_supported(struct sock *sk, int len,
                           char __user *optval,
                           int __user *optlen)
 {
     struct sctp_assoc_value params;
     struct sctp_association *asoc;
     int retval = -EFAULT;
 
     if (len < sizeof(params)) {
         retval = -EINVAL;
         goto out;
     }
 
     len = sizeof(params);
     if (copy_from_user(&params, optval, len))
         goto out;
 
     asoc = sctp_id2assoc(sk, params.assoc_id);
     if (!asoc && params.assoc_id != SCTP_FUTURE_ASSOC &&
         sctp_style(sk, UDP)) {
         retval = -EINVAL;
         goto out;
     }
 
     params.assoc_value = asoc ? asoc->peer.reconf_capable
                   : sctp_sk(sk)->ep->reconf_enable;
 
     if (put_user(len, optlen))
         goto out;
 
     if (copy_to_user(optval, &params, len))
         goto out;
 
     retval = 0;
 
 out:
     return retval;
 }
 
 static int sctp_getsockopt_enable_strreset(struct sock *sk, int len,
                        char __user *optval,
                        int __user *optlen)
 {
     struct sctp_assoc_value params;
     struct sctp_association *asoc;
     int retval = -EFAULT;
 
     if (len < sizeof(params)) {
         retval = -EINVAL;
         goto out;
     }
 
     len = sizeof(params);
     if (copy_from_user(&params, optval, len))
         goto out;
 
     asoc = sctp_id2assoc(sk, params.assoc_id);
     if (!asoc && params.assoc_id != SCTP_FUTURE_ASSOC &&
         sctp_style(sk, UDP)) {
         retval = -EINVAL;
         goto out;
     }
 
     params.assoc_value = asoc ? asoc->strreset_enable
                   : sctp_sk(sk)->ep->strreset_enable;
 
     if (put_user(len, optlen))
         goto out;
 
     if (copy_to_user(optval, &params, len))
         goto out;
 
     retval = 0;
 
 out:
     return retval;
 }
 
 static int sctp_getsockopt_scheduler(struct sock *sk, int len,
                      char __user *optval,
                      int __user *optlen)
 {
     struct sctp_assoc_value params;
     struct sctp_association *asoc;
     int retval = -EFAULT;
 
     if (len < sizeof(params)) {
         retval = -EINVAL;
         goto out;
     }
 
     len = sizeof(params);
     if (copy_from_user(&params, optval, len))
         goto out;
 
     asoc = sctp_id2assoc(sk, params.assoc_id);
     if (!asoc && params.assoc_id != SCTP_FUTURE_ASSOC &&
         sctp_style(sk, UDP)) {
         retval = -EINVAL;
         goto out;
     }
 
     params.assoc_value = asoc ? sctp_sched_get_sched(asoc)
                   : sctp_sk(sk)->default_ss;
 
     if (put_user(len, optlen))
         goto out;
 
     if (copy_to_user(optval, &params, len))
         goto out;
 
     retval = 0;
 
 out:
     return retval;
 }
 
 static int sctp_getsockopt_scheduler_value(struct sock *sk, int len,
                        char __user *optval,
                        int __user *optlen)
 {
     struct sctp_stream_value params;
     struct sctp_association *asoc;
     int retval = -EFAULT;
 
     if (len < sizeof(params)) {
         retval = -EINVAL;
         goto out;
     }
 
     len = sizeof(params);
     if (copy_from_user(&params, optval, len))
         goto out;
 
     asoc = sctp_id2assoc(sk, params.assoc_id);
     if (!asoc) {
         retval = -EINVAL;
         goto out;
     }
 
     retval = sctp_sched_get_value(asoc, params.stream_id,
                       &params.stream_value);
     if (retval)
         goto out;
 
     if (put_user(len, optlen)) {
         retval = -EFAULT;
         goto out;
     }
 
     if (copy_to_user(optval, &params, len)) {
         retval = -EFAULT;
         goto out;
     }
 
 out:
     return retval;
 }
 
 static int sctp_getsockopt_interleaving_supported(struct sock *sk, int len,
                           char __user *optval,
                           int __user *optlen)
 {
     struct sctp_assoc_value params;
     struct sctp_association *asoc;
     int retval = -EFAULT;
 
     if (len < sizeof(params)) {
         retval = -EINVAL;
         goto out;
     }
 
     len = sizeof(params);
     if (copy_from_user(&params, optval, len))
         goto out;
 
     asoc = sctp_id2assoc(sk, params.assoc_id);
     if (!asoc && params.assoc_id != SCTP_FUTURE_ASSOC &&
         sctp_style(sk, UDP)) {
         retval = -EINVAL;
         goto out;
     }
 
     params.assoc_value = asoc ? asoc->peer.intl_capable
                   : sctp_sk(sk)->ep->intl_enable;
 
     if (put_user(len, optlen))
         goto out;
 
     if (copy_to_user(optval, &params, len))
         goto out;
 
     retval = 0;
 
 out:
     return retval;
 }
 
 static int sctp_getsockopt_reuse_port(struct sock *sk, int len,
                       char __user *optval,
                       int __user *optlen)
 {
     int val;
 
     if (len < sizeof(int))
         return -EINVAL;
 
     len = sizeof(int);
     val = sctp_sk(sk)->reuse;
     if (put_user(len, optlen))
         return -EFAULT;
 
     if (copy_to_user(optval, &val, len))
         return -EFAULT;
 
     return 0;
 }
 
 static int sctp_getsockopt_event(struct sock *sk, int len, char __user *optval,
                  int __user *optlen)
 {
     struct sctp_association *asoc;
     struct sctp_event param;
     __u16 subscribe;
 
     if (len < sizeof(param))
         return -EINVAL;
 
     len = sizeof(param);
     if (copy_from_user(&param, optval, len))
         return -EFAULT;
 
     if (param.se_type < SCTP_SN_TYPE_BASE ||
         param.se_type > SCTP_SN_TYPE_MAX)
         return -EINVAL;
 
     asoc = sctp_id2assoc(sk, param.se_assoc_id);
     if (!asoc && param.se_assoc_id != SCTP_FUTURE_ASSOC &&
         sctp_style(sk, UDP))
         return -EINVAL;
 
     subscribe = asoc ? asoc->subscribe : sctp_sk(sk)->subscribe;
     param.se_on = sctp_ulpevent_type_enabled(subscribe, param.se_type);
 
     if (put_user(len, optlen))
         return -EFAULT;
 
     if (copy_to_user(optval, &param, len))
         return -EFAULT;
 
     return 0;
 }
 
 static int sctp_getsockopt_asconf_supported(struct sock *sk, int len,
                         char __user *optval,
                         int __user *optlen)
 {
     struct sctp_assoc_value params;
     struct sctp_association *asoc;
     int retval = -EFAULT;
 
     if (len < sizeof(params)) {
         retval = -EINVAL;
         goto out;
     }
 
     len = sizeof(params);
     if (copy_from_user(&params, optval, len))
         goto out;
 
     asoc = sctp_id2assoc(sk, params.assoc_id);
     if (!asoc && params.assoc_id != SCTP_FUTURE_ASSOC &&
         sctp_style(sk, UDP)) {
         retval = -EINVAL;
         goto out;
     }
 
     params.assoc_value = asoc ? asoc->peer.asconf_capable
                   : sctp_sk(sk)->ep->asconf_enable;
 
     if (put_user(len, optlen))
         goto out;
 
     if (copy_to_user(optval, &params, len))
         goto out;
 
     retval = 0;
 
 out:
     return retval;
 }
 
 static int sctp_getsockopt_auth_supported(struct sock *sk, int len,
                       char __user *optval,
                       int __user *optlen)
 {
     struct sctp_assoc_value params;
     struct sctp_association *asoc;
     int retval = -EFAULT;
 
     if (len < sizeof(params)) {
         retval = -EINVAL;
         goto out;
     }
 
     len = sizeof(params);
     if (copy_from_user(&params, optval, len))
         goto out;
 
     asoc = sctp_id2assoc(sk, params.assoc_id);
     if (!asoc && params.assoc_id != SCTP_FUTURE_ASSOC &&
         sctp_style(sk, UDP)) {
         retval = -EINVAL;
         goto out;
     }
 
     params.assoc_value = asoc ? asoc->peer.auth_capable
                   : sctp_sk(sk)->ep->auth_enable;
 
     if (put_user(len, optlen))
         goto out;
 
     if (copy_to_user(optval, &params, len))
         goto out;
 
     retval = 0;
 
 out:
     return retval;
 }
 
 static int sctp_getsockopt_ecn_supported(struct sock *sk, int len,
                      char __user *optval,
                      int __user *optlen)
 {
     struct sctp_assoc_value params;
     struct sctp_association *asoc;
     int retval = -EFAULT;
 
     if (len < sizeof(params)) {
         retval = -EINVAL;
         goto out;
     }
 
     len = sizeof(params);
     if (copy_from_user(&params, optval, len))
         goto out;
 
     asoc = sctp_id2assoc(sk, params.assoc_id);
     if (!asoc && params.assoc_id != SCTP_FUTURE_ASSOC &&
         sctp_style(sk, UDP)) {
         retval = -EINVAL;
         goto out;
     }
 
     params.assoc_value = asoc ? asoc->peer.ecn_capable
                   : sctp_sk(sk)->ep->ecn_enable;
 
     if (put_user(len, optlen))
         goto out;
 
     if (copy_to_user(optval, &params, len))
         goto out;
 
     retval = 0;
 
 out:
     return retval;
 }
 
 static int sctp_getsockopt_pf_expose(struct sock *sk, int len,
                      char __user *optval,
                      int __user *optlen)
 {
     struct sctp_assoc_value params;
     struct sctp_association *asoc;
     int retval = -EFAULT;
 
     if (len < sizeof(params)) {
         retval = -EINVAL;
         goto out;
     }
 
     len = sizeof(params);
     if (copy_from_user(&params, optval, len))
         goto out;
 
     asoc = sctp_id2assoc(sk, params.assoc_id);
     if (!asoc && params.assoc_id != SCTP_FUTURE_ASSOC &&
         sctp_style(sk, UDP)) {
         retval = -EINVAL;
         goto out;
     }
 
     params.assoc_value = asoc ? asoc->pf_expose
                   : sctp_sk(sk)->pf_expose;
 
     if (put_user(len, optlen))
         goto out;
 
     if (copy_to_user(optval, &params, len))
         goto out;
 
     retval = 0;
 
 out:
     return retval;
 }
 
 static int sctp_getsockopt_encap_port(struct sock *sk, int len,
                       char __user *optval, int __user *optlen)
 {
     struct sctp_association *asoc;
     struct sctp_udpencaps encap;
     struct sctp_transport *t;
     __be16 encap_port;
 
     if (len < sizeof(encap))
         return -EINVAL;
 
     len = sizeof(encap);
     if (copy_from_user(&encap, optval, len))
         return -EFAULT;
 
     /* If an address other than INADDR_ANY is specified, and
      * no transport is found, then the request is invalid.
      */
     if (!sctp_is_any(sk, (union sctp_addr *)&encap.sue_address)) {
         t = sctp_addr_id2transport(sk, &encap.sue_address,
                        encap.sue_assoc_id);
         if (!t) {
             pr_debug("%s: failed no transport\n", __func__);
             return -EINVAL;
         }
 
         encap_port = t->encap_port;
         goto out;
     }
 
     /* Get association, if assoc_id != SCTP_FUTURE_ASSOC and the
      * socket is a one to many style socket, and an association
      * was not found, then the id was invalid.
      */
     asoc = sctp_id2assoc(sk, encap.sue_assoc_id);
     if (!asoc && encap.sue_assoc_id != SCTP_FUTURE_ASSOC &&
         sctp_style(sk, UDP)) {
         pr_debug("%s: failed no association\n", __func__);
         return -EINVAL;
     }
 
     if (asoc) {
         encap_port = asoc->encap_port;
         goto out;
     }
 
     encap_port = sctp_sk(sk)->encap_port;
 
 out:
     encap.sue_port = (__force uint16_t)encap_port;
     if (copy_to_user(optval, &encap, len))
         return -EFAULT;
 
     if (put_user(len, optlen))
         return -EFAULT;
 
     return 0;
 }
 
 static int sctp_getsockopt_probe_interval(struct sock *sk, int len,
                       char __user *optval,
                       int __user *optlen)
 {
     struct sctp_probeinterval params;
     struct sctp_association *asoc;
     struct sctp_transport *t;
     __u32 probe_interval;
 
     if (len < sizeof(params))
         return -EINVAL;
 
     len = sizeof(params);
     if (copy_from_user(&params, optval, len))
         return -EFAULT;
 
     /* If an address other than INADDR_ANY is specified, and
      * no transport is found, then the request is invalid.
      */
     if (!sctp_is_any(sk, (union sctp_addr *)&params.spi_address)) {
         t = sctp_addr_id2transport(sk, &params.spi_address,
                        params.spi_assoc_id);
         if (!t) {
             pr_debug("%s: failed no transport\n", __func__);
             return -EINVAL;
         }
 
         probe_interval = jiffies_to_msecs(t->probe_interval);
         goto out;
     }
 
     /* Get association, if assoc_id != SCTP_FUTURE_ASSOC and the
      * socket is a one to many style socket, and an association
      * was not found, then the id was invalid.
      */
     asoc = sctp_id2assoc(sk, params.spi_assoc_id);
     if (!asoc && params.spi_assoc_id != SCTP_FUTURE_ASSOC &&
         sctp_style(sk, UDP)) {
         pr_debug("%s: failed no association\n", __func__);
         return -EINVAL;
     }
 
     if (asoc) {
         probe_interval = jiffies_to_msecs(asoc->probe_interval);
         goto out;
     }
 
     probe_interval = sctp_sk(sk)->probe_interval;
 
 out:
     params.spi_interval = probe_interval;
     if (copy_to_user(optval, &params, len))
         return -EFAULT;
 
     if (put_user(len, optlen))
         return -EFAULT;
 
     return 0;
 }
 
 static int sctp_getsockopt(struct sock *sk, int level, int optname,
                char __user *optval, int __user *optlen)
 {
     int retval = 0;
     int len;
 
     pr_debug("%s: sk:%p, optname:%d\n", __func__, sk, optname);
 
     /* I can hardly begin to describe how wrong this is.  This is
      * so broken as to be worse than useless.  The API draft
      * REALLY is NOT helpful here...  I am not convinced that the
      * semantics of getsockopt() with a level OTHER THAN SOL_SCTP
      * are at all well-founded.
      */
     if (level != SOL_SCTP) {
         struct sctp_af *af = sctp_sk(sk)->pf->af;
 
         retval = af->getsockopt(sk, level, optname, optval, optlen);
         return retval;
     }
 
     if (get_user(len, optlen))
         return -EFAULT;
 
     if (len < 0)
         return -EINVAL;
 
     lock_sock(sk);
 
     switch (optname) {
     case SCTP_STATUS:
         retval = sctp_getsockopt_sctp_status(sk, len, optval, optlen);
         break;
     case SCTP_DISABLE_FRAGMENTS:
         retval = sctp_getsockopt_disable_fragments(sk, len, optval,
                                optlen);
         break;
     case SCTP_EVENTS:
         retval = sctp_getsockopt_events(sk, len, optval, optlen);
         break;
     case SCTP_AUTOCLOSE:
         retval = sctp_getsockopt_autoclose(sk, len, optval, optlen);
         break;
     case SCTP_SOCKOPT_PEELOFF:
         retval = sctp_getsockopt_peeloff(sk, len, optval, optlen);
         break;
     case SCTP_SOCKOPT_PEELOFF_FLAGS:
         retval = sctp_getsockopt_peeloff_flags(sk, len, optval, optlen);
         break;
     case SCTP_PEER_ADDR_PARAMS:
         retval = sctp_getsockopt_peer_addr_params(sk, len, optval,
                               optlen);
         break;
     case SCTP_DELAYED_SACK:
         retval = sctp_getsockopt_delayed_ack(sk, len, optval,
                               optlen);
         break;
     case SCTP_INITMSG:
         retval = sctp_getsockopt_initmsg(sk, len, optval, optlen);
         break;
     case SCTP_GET_PEER_ADDRS:
         retval = sctp_getsockopt_peer_addrs(sk, len, optval,
                             optlen);
         break;
     case SCTP_GET_LOCAL_ADDRS:
         retval = sctp_getsockopt_local_addrs(sk, len, optval,
                              optlen);
         break;
     case SCTP_SOCKOPT_CONNECTX3:
         retval = sctp_getsockopt_connectx3(sk, len, optval, optlen);
         break;
     case SCTP_DEFAULT_SEND_PARAM:
         retval = sctp_getsockopt_default_send_param(sk, len,
                                 optval, optlen);
         break;
     case SCTP_DEFAULT_SNDINFO:
         retval = sctp_getsockopt_default_sndinfo(sk, len,
                              optval, optlen);
         break;
     case SCTP_PRIMARY_ADDR:
         retval = sctp_getsockopt_primary_addr(sk, len, optval, optlen);
         break;
     case SCTP_NODELAY:
         retval = sctp_getsockopt_nodelay(sk, len, optval, optlen);
         break;
     case SCTP_RTOINFO:
         retval = sctp_getsockopt_rtoinfo(sk, len, optval, optlen);
         break;
     case SCTP_ASSOCINFO:
         retval = sctp_getsockopt_associnfo(sk, len, optval, optlen);
         break;
     case SCTP_I_WANT_MAPPED_V4_ADDR:
         retval = sctp_getsockopt_mappedv4(sk, len, optval, optlen);
         break;
     case SCTP_MAXSEG:
         retval = sctp_getsockopt_maxseg(sk, len, optval, optlen);
         break;
     case SCTP_GET_PEER_ADDR_INFO:
         retval = sctp_getsockopt_peer_addr_info(sk, len, optval,
                             optlen);
         break;
     case SCTP_ADAPTATION_LAYER:
         retval = sctp_getsockopt_adaptation_layer(sk, len, optval,
                             optlen);
         break;
     case SCTP_CONTEXT:
         retval = sctp_getsockopt_context(sk, len, optval, optlen);
         break;
     case SCTP_FRAGMENT_INTERLEAVE:
         retval = sctp_getsockopt_fragment_interleave(sk, len, optval,
                                  optlen);
         break;
     case SCTP_PARTIAL_DELIVERY_POINT:
         retval = sctp_getsockopt_partial_delivery_point(sk, len, optval,
                                 optlen);
         break;
     case SCTP_MAX_BURST:
         retval = sctp_getsockopt_maxburst(sk, len, optval, optlen);
         break;
     case SCTP_AUTH_KEY:
     case SCTP_AUTH_CHUNK:
     case SCTP_AUTH_DELETE_KEY:
     case SCTP_AUTH_DEACTIVATE_KEY:
         retval = -EOPNOTSUPP;
         break;
     case SCTP_HMAC_IDENT:
         retval = sctp_getsockopt_hmac_ident(sk, len, optval, optlen);
         break;
     case SCTP_AUTH_ACTIVE_KEY:
         retval = sctp_getsockopt_active_key(sk, len, optval, optlen);
         break;
     case SCTP_PEER_AUTH_CHUNKS:
         retval = sctp_getsockopt_peer_auth_chunks(sk, len, optval,
                             optlen);
         break;
     case SCTP_LOCAL_AUTH_CHUNKS:
         retval = sctp_getsockopt_local_auth_chunks(sk, len, optval,
                             optlen);
         break;
     case SCTP_GET_ASSOC_NUMBER:
         retval = sctp_getsockopt_assoc_number(sk, len, optval, optlen);
         break;
     case SCTP_GET_ASSOC_ID_LIST:
         retval = sctp_getsockopt_assoc_ids(sk, len, optval, optlen);
         break;
     case SCTP_AUTO_ASCONF:
         retval = sctp_getsockopt_auto_asconf(sk, len, optval, optlen);
         break;
     case SCTP_PEER_ADDR_THLDS:
         retval = sctp_getsockopt_paddr_thresholds(sk, optval, len,
                               optlen, false);
         break;
     case SCTP_PEER_ADDR_THLDS_V2:
         retval = sctp_getsockopt_paddr_thresholds(sk, optval, len,
                               optlen, true);
         break;
     case SCTP_GET_ASSOC_STATS:
         retval = sctp_getsockopt_assoc_stats(sk, len, optval, optlen);
         break;
     case SCTP_RECVRCVINFO:
         retval = sctp_getsockopt_recvrcvinfo(sk, len, optval, optlen);
         break;
     case SCTP_RECVNXTINFO:
         retval = sctp_getsockopt_recvnxtinfo(sk, len, optval, optlen);
         break;
     case SCTP_PR_SUPPORTED:
         retval = sctp_getsockopt_pr_supported(sk, len, optval, optlen);
         break;
     case SCTP_DEFAULT_PRINFO:
         retval = sctp_getsockopt_default_prinfo(sk, len, optval,
                             optlen);
         break;
     case SCTP_PR_ASSOC_STATUS:
         retval = sctp_getsockopt_pr_assocstatus(sk, len, optval,
                             optlen);
         break;
     case SCTP_PR_STREAM_STATUS:
         retval = sctp_getsockopt_pr_streamstatus(sk, len, optval,
                              optlen);
         break;
     case SCTP_RECONFIG_SUPPORTED:
         retval = sctp_getsockopt_reconfig_supported(sk, len, optval,
                                 optlen);
         break;
     case SCTP_ENABLE_STREAM_RESET:
         retval = sctp_getsockopt_enable_strreset(sk, len, optval,
                              optlen);
         break;
     case SCTP_STREAM_SCHEDULER:
         retval = sctp_getsockopt_scheduler(sk, len, optval,
                            optlen);
         break;
     case SCTP_STREAM_SCHEDULER_VALUE:
         retval = sctp_getsockopt_scheduler_value(sk, len, optval,
                              optlen);
         break;
     case SCTP_INTERLEAVING_SUPPORTED:
         retval = sctp_getsockopt_interleaving_supported(sk, len, optval,
                                 optlen);
         break;
     case SCTP_REUSE_PORT:
         retval = sctp_getsockopt_reuse_port(sk, len, optval, optlen);
         break;
     case SCTP_EVENT:
         retval = sctp_getsockopt_event(sk, len, optval, optlen);
         break;
     case SCTP_ASCONF_SUPPORTED:
         retval = sctp_getsockopt_asconf_supported(sk, len, optval,
                               optlen);
         break;
     case SCTP_AUTH_SUPPORTED:
         retval = sctp_getsockopt_auth_supported(sk, len, optval,
                             optlen);
         break;
     case SCTP_ECN_SUPPORTED:
         retval = sctp_getsockopt_ecn_supported(sk, len, optval, optlen);
         break;
     case SCTP_EXPOSE_POTENTIALLY_FAILED_STATE:
         retval = sctp_getsockopt_pf_expose(sk, len, optval, optlen);
         break;
     case SCTP_REMOTE_UDP_ENCAPS_PORT:
         retval = sctp_getsockopt_encap_port(sk, len, optval, optlen);
         break;
     case SCTP_PLPMTUD_PROBE_INTERVAL:
         retval = sctp_getsockopt_probe_interval(sk, len, optval, optlen);
         break;
     default:
         retval = -ENOPROTOOPT;
         break;
     }
 
     release_sock(sk);
     return retval;
 }
 
 static int sctp_hash(struct sock *sk)
 {
     /* STUB */
     return 0;
 }
 
 static void sctp_unhash(struct sock *sk)
 {
     /* STUB */
 }
 
 /* Check if port is acceptable.  Possibly find first available port.
  *
  * The port hash table (contained in the 'global' SCTP protocol storage
  * returned by struct sctp_protocol *sctp_get_protocol()). The hash
  * table is an array of 4096 lists (sctp_bind_hashbucket). Each
  * list (the list number is the port number hashed out, so as you
  * would expect from a hash function, all the ports in a given list have
  * such a number that hashes out to the same list number; you were
  * expecting that, right?); so each list has a set of ports, with a
  * link to the socket (struct sock) that uses it, the port number and
  * a fastreuse flag (FIXME: NPI ipg).
  */
 static struct sctp_bind_bucket *sctp_bucket_create(
     struct sctp_bind_hashbucket *head, struct net *, unsigned short snum);
 
 static int sctp_get_port_local(struct sock *sk, union sctp_addr *addr)
 {
     struct sctp_sock *sp = sctp_sk(sk);
     bool reuse = (sk->sk_reuse || sp->reuse);
     struct sctp_bind_hashbucket *head; /* hash list */
     struct net *net = sock_net(sk);
     kuid_t uid = sock_i_uid(sk);
     struct sctp_bind_bucket *pp;
     unsigned short snum;
     int ret;
 
     snum = ntohs(addr->v4.sin_port);
 
     pr_debug("%s: begins, snum:%d\n", __func__, snum);
 
     if (snum == 0) {
         /* Search for an available port. */
         int low, high, remaining, index;
         unsigned int rover;
 
         inet_get_local_port_range(net, &low, &high);
         remaining = (high - low) + 1;
         rover = prandom_u32() % remaining + low;
 
         do {
             rover++;
             if ((rover < low) || (rover > high))
                 rover = low;
             if (inet_is_local_reserved_port(net, rover))
                 continue;
             index = sctp_phashfn(net, rover);
             head = &sctp_port_hashtable[index];
             spin_lock_bh(&head->lock);
             sctp_for_each_hentry(pp, &head->chain)
                 if ((pp->port == rover) &&
                     net_eq(net, pp->net))
                     goto next;
             break;
         next:
             spin_unlock_bh(&head->lock);
             cond_resched();
         } while (--remaining > 0);
 
         /* Exhausted local port range during search? */
         ret = 1;
         if (remaining <= 0)
             return ret;
 
         /* OK, here is the one we will use.  HEAD (the port
          * hash table list entry) is non-NULL and we hold it's
          * mutex.
          */
         snum = rover;
     } else {
         /* We are given an specific port number; we verify
          * that it is not being used. If it is used, we will
          * exahust the search in the hash list corresponding
          * to the port number (snum) - we detect that with the
          * port iterator, pp being NULL.
          */
         head = &sctp_port_hashtable[sctp_phashfn(net, snum)];
         spin_lock_bh(&head->lock);
         sctp_for_each_hentry(pp, &head->chain) {
             if ((pp->port == snum) && net_eq(pp->net, net))
                 goto pp_found;
         }
     }
     pp = NULL;
     goto pp_not_found;
 pp_found:
     if (!hlist_empty(&pp->owner)) {
         /* We had a port hash table hit - there is an
          * available port (pp != NULL) and it is being
          * used by other socket (pp->owner not empty); that other
          * socket is going to be sk2.
          */
         struct sock *sk2;
 
         pr_debug("%s: found a possible match\n", __func__);
 
         if ((pp->fastreuse && reuse &&
              sk->sk_state != SCTP_SS_LISTENING) ||
             (pp->fastreuseport && sk->sk_reuseport &&
              uid_eq(pp->fastuid, uid)))
             goto success;
 
         /* Run through the list of sockets bound to the port
          * (pp->port) [via the pointers bind_next and
          * bind_pprev in the struct sock *sk2 (pp->sk)]. On each one,
          * we get the endpoint they describe and run through
          * the endpoint's list of IP (v4 or v6) addresses,
          * comparing each of the addresses with the address of
          * the socket sk. If we find a match, then that means
          * that this port/socket (sk) combination are already
          * in an endpoint.
          */
         sk_for_each_bound(sk2, &pp->owner) {
             struct sctp_sock *sp2 = sctp_sk(sk2);
             struct sctp_endpoint *ep2 = sp2->ep;
 
             if (sk == sk2 ||
                 (reuse && (sk2->sk_reuse || sp2->reuse) &&
                  sk2->sk_state != SCTP_SS_LISTENING) ||
                 (sk->sk_reuseport && sk2->sk_reuseport &&
                  uid_eq(uid, sock_i_uid(sk2))))
                 continue;
 
             if (sctp_bind_addr_conflict(&ep2->base.bind_addr,
                             addr, sp2, sp)) {
                 ret = 1;
                 goto fail_unlock;
             }
         }
 
         pr_debug("%s: found a match\n", __func__);
     }
 pp_not_found:
     /* If there was a hash table miss, create a new port.  */
     ret = 1;
     if (!pp && !(pp = sctp_bucket_create(head, net, snum)))
         goto fail_unlock;
 
     /* In either case (hit or miss), make sure fastreuse is 1 only
      * if sk->sk_reuse is too (that is, if the caller requested
      * SO_REUSEADDR on this socket -sk-).
      */
     if (hlist_empty(&pp->owner)) {
         if (reuse && sk->sk_state != SCTP_SS_LISTENING)
             pp->fastreuse = 1;
         else
             pp->fastreuse = 0;
 
         if (sk->sk_reuseport) {
             pp->fastreuseport = 1;
             pp->fastuid = uid;
         } else {
             pp->fastreuseport = 0;
         }
     } else {
         if (pp->fastreuse &&
             (!reuse || sk->sk_state == SCTP_SS_LISTENING))
             pp->fastreuse = 0;
 
         if (pp->fastreuseport &&
             (!sk->sk_reuseport || !uid_eq(pp->fastuid, uid)))
             pp->fastreuseport = 0;
     }
 
     /* We are set, so fill up all the data in the hash table
      * entry, tie the socket list information with the rest of the
      * sockets FIXME: Blurry, NPI (ipg).
      */
 success:
     if (!sp->bind_hash) {
         inet_sk(sk)->inet_num = snum;
         sk_add_bind_node(sk, &pp->owner);
         sp->bind_hash = pp;
     }
     ret = 0;
 
 fail_unlock:
     spin_unlock_bh(&head->lock);
     return ret;
 }
 
 /* Assign a 'snum' port to the socket.  If snum == 0, an ephemeral
  * port is requested.
  */
 static int sctp_get_port(struct sock *sk, unsigned short snum)
 {
     union sctp_addr addr;
     struct sctp_af *af = sctp_sk(sk)->pf->af;
 
     /* Set up a dummy address struct from the sk. */
     af->from_sk(&addr, sk);
     addr.v4.sin_port = htons(snum);
 
     /* Note: sk->sk_num gets filled in if ephemeral port request. */
     return sctp_get_port_local(sk, &addr);
 }
 
 /*
  *  Move a socket to LISTENING state.
  */
 static int sctp_listen_start(struct sock *sk, int backlog)
 {
     struct sctp_sock *sp = sctp_sk(sk);
     struct sctp_endpoint *ep = sp->ep;
     struct crypto_shash *tfm = NULL;
     char alg[32];
 
     /* Allocate HMAC for generating cookie. */
     if (!sp->hmac && sp->sctp_hmac_alg) {
         sprintf(alg, "hmac(%s)", sp->sctp_hmac_alg);
         tfm = crypto_alloc_shash(alg, 0, 0);
         if (IS_ERR(tfm)) {
             net_info_ratelimited("failed to load transform for %s: %ld\n",
                          sp->sctp_hmac_alg, PTR_ERR(tfm));
             return -ENOSYS;
         }
         sctp_sk(sk)->hmac = tfm;
     }
 
     /*
      * If a bind() or sctp_bindx() is not called prior to a listen()
      * call that allows new associations to be accepted, the system
      * picks an ephemeral port and will choose an address set equivalent
      * to binding with a wildcard address.
      *
      * This is not currently spelled out in the SCTP sockets
      * extensions draft, but follows the practice as seen in TCP
      * sockets.
      *
      */
     inet_sk_set_state(sk, SCTP_SS_LISTENING);
     if (!ep->base.bind_addr.port) {
         if (sctp_autobind(sk))
             return -EAGAIN;
     } else {
         if (sctp_get_port(sk, inet_sk(sk)->inet_num)) {
             inet_sk_set_state(sk, SCTP_SS_CLOSED);
             return -EADDRINUSE;
         }
     }
 
     WRITE_ONCE(sk->sk_max_ack_backlog, backlog);
     return sctp_hash_endpoint(ep);
 }
 
 /*
  * 4.1.3 / 5.1.3 listen()
  *
  *   By default, new associations are not accepted for UDP style sockets.
  *   An application uses listen() to mark a socket as being able to
  *   accept new associations.
  *
  *   On TCP style sockets, applications use listen() to ready the SCTP
  *   endpoint for accepting inbound associations.
  *
  *   On both types of endpoints a backlog of '0' disables listening.
  *
  *  Move a socket to LISTENING state.
  */
 int sctp_inet_listen(struct socket *sock, int backlog)
 {
     struct sock *sk = sock->sk;
     struct sctp_endpoint *ep = sctp_sk(sk)->ep;
     int err = -EINVAL;
 
     if (unlikely(backlog < 0))
         return err;
 
     lock_sock(sk);
 
     /* Peeled-off sockets are not allowed to listen().  */
     if (sctp_style(sk, UDP_HIGH_BANDWIDTH))
         goto out;
 
     if (sock->state != SS_UNCONNECTED)
         goto out;
 
     if (!sctp_sstate(sk, LISTENING) && !sctp_sstate(sk, CLOSED))
         goto out;
 
     /* If backlog is zero, disable listening. */
     if (!backlog) {
         if (sctp_sstate(sk, CLOSED))
             goto out;
 
         err = 0;
         sctp_unhash_endpoint(ep);
         sk->sk_state = SCTP_SS_CLOSED;
         if (sk->sk_reuse || sctp_sk(sk)->reuse)
             sctp_sk(sk)->bind_hash->fastreuse = 1;
         goto out;
     }
 
     /* If we are already listening, just update the backlog */
     if (sctp_sstate(sk, LISTENING))
         WRITE_ONCE(sk->sk_max_ack_backlog, backlog);
     else {
         err = sctp_listen_start(sk, backlog);
         if (err)
             goto out;
     }
 
     err = 0;
 out:
     release_sock(sk);
     return err;
 }
 
 /*
  * This function is done by modeling the current datagram_poll() and the
  * tcp_poll().  Note that, based on these implementations, we don't
  * lock the socket in this function, even though it seems that,
  * ideally, locking or some other mechanisms can be used to ensure
  * the integrity of the counters (sndbuf and wmem_alloc) used
  * in this place.  We assume that we don't need locks either until proven
  * otherwise.
  *
  * Another thing to note is that we include the Async I/O support
  * here, again, by modeling the current TCP/UDP code.  We don't have
  * a good way to test with it yet.
  */
 __poll_t sctp_poll(struct file *file, struct socket *sock, poll_table *wait)
 {
     struct sock *sk = sock->sk;
     struct sctp_sock *sp = sctp_sk(sk);
     __poll_t mask;
 
     poll_wait(file, sk_sleep(sk), wait);
 
     sock_rps_record_flow(sk);
 
     /* A TCP-style listening socket becomes readable when the accept queue
      * is not empty.
      */
     if (sctp_style(sk, TCP) && sctp_sstate(sk, LISTENING))
         return (!list_empty(&sp->ep->asocs)) ?
             (EPOLLIN | EPOLLRDNORM) : 0;
 
     mask = 0;
 
     /* Is there any exceptional events?  */
     if (sk->sk_err || !skb_queue_empty_lockless(&sk->sk_error_queue))
         mask |= EPOLLERR |
             (sock_flag(sk, SOCK_SELECT_ERR_QUEUE) ? EPOLLPRI : 0);
     if (sk->sk_shutdown & RCV_SHUTDOWN)
         mask |= EPOLLRDHUP | EPOLLIN | EPOLLRDNORM;
     if (sk->sk_shutdown == SHUTDOWN_MASK)
         mask |= EPOLLHUP;
 
     /* Is it readable?  Reconsider this code with TCP-style support.  */
     if (!skb_queue_empty_lockless(&sk->sk_receive_queue))
         mask |= EPOLLIN | EPOLLRDNORM;
 
     /* The association is either gone or not ready.  */
     if (!sctp_style(sk, UDP) && sctp_sstate(sk, CLOSED))
         return mask;
 
     /* Is it writable?  */
     if (sctp_writeable(sk)) {
         mask |= EPOLLOUT | EPOLLWRNORM;
     } else {
         sk_set_bit(SOCKWQ_ASYNC_NOSPACE, sk);
         /*
          * Since the socket is not locked, the buffer
          * might be made available after the writeable check and
          * before the bit is set.  This could cause a lost I/O
          * signal.  tcp_poll() has a race breaker for this race
          * condition.  Based on their implementation, we put
          * in the following code to cover it as well.
          */
         if (sctp_writeable(sk))
             mask |= EPOLLOUT | EPOLLWRNORM;
     }
     return mask;
 }
 
 /********************************************************************
  * 2nd Level Abstractions
  ********************************************************************/
 
 static struct sctp_bind_bucket *sctp_bucket_create(
     struct sctp_bind_hashbucket *head, struct net *net, unsigned short snum)
 {
     struct sctp_bind_bucket *pp;
 
     pp = kmem_cache_alloc(sctp_bucket_cachep, GFP_ATOMIC);
     if (pp) {
         SCTP_DBG_OBJCNT_INC(bind_bucket);
         pp->port = snum;
         pp->fastreuse = 0;
         INIT_HLIST_HEAD(&pp->owner);
         pp->net = net;
         hlist_add_head(&pp->node, &head->chain);
     }
     return pp;
 }
 
 /* Caller must hold hashbucket lock for this tb with local BH disabled */
 static void sctp_bucket_destroy(struct sctp_bind_bucket *pp)
 {
     if (pp && hlist_empty(&pp->owner)) {
         __hlist_del(&pp->node);
         kmem_cache_free(sctp_bucket_cachep, pp);
         SCTP_DBG_OBJCNT_DEC(bind_bucket);
     }
 }
 
 /* Release this socket's reference to a local port.  */
 static inline void __sctp_put_port(struct sock *sk)
 {
     struct sctp_bind_hashbucket *head =
         &sctp_port_hashtable[sctp_phashfn(sock_net(sk),
                           inet_sk(sk)->inet_num)];
     struct sctp_bind_bucket *pp;
 
     spin_lock(&head->lock);
     pp = sctp_sk(sk)->bind_hash;
     __sk_del_bind_node(sk);
     sctp_sk(sk)->bind_hash = NULL;
     inet_sk(sk)->inet_num = 0;
     sctp_bucket_destroy(pp);
     spin_unlock(&head->lock);
 }
 
 void sctp_put_port(struct sock *sk)
 {
     local_bh_disable();
     __sctp_put_port(sk);
     local_bh_enable();
 }
 
 /*
  * The system picks an ephemeral port and choose an address set equivalent
  * to binding with a wildcard address.
  * One of those addresses will be the primary address for the association.
  * This automatically enables the multihoming capability of SCTP.
  */
 static int sctp_autobind(struct sock *sk)
 {
     union sctp_addr autoaddr;
     struct sctp_af *af;
     __be16 port;
 
     /* Initialize a local sockaddr structure to INADDR_ANY. */
     af = sctp_sk(sk)->pf->af;
 
     port = htons(inet_sk(sk)->inet_num);
     af->inaddr_any(&autoaddr, port);
 
     return sctp_do_bind(sk, &autoaddr, af->sockaddr_len);
 }
 
 /* Parse out IPPROTO_SCTP CMSG headers.  Perform only minimal validation.
  *
  * From RFC 2292
  * 4.2 The cmsghdr Structure *
  *
  * When ancillary data is sent or received, any number of ancillary data
  * objects can be specified by the msg_control and msg_controllen members of
  * the msghdr structure, because each object is preceded by
  * a cmsghdr structure defining the object's length (the cmsg_len member).
  * Historically Berkeley-derived implementations have passed only one object
  * at a time, but this API allows multiple objects to be
  * passed in a single call to sendmsg() or recvmsg(). The following example
  * shows two ancillary data objects in a control buffer.
  *
  *   |<--------------------------- msg_controllen -------------------------->|
  *   |                                                                       |
  *
  *   |<----- ancillary data object ----->|<----- ancillary data object ----->|
  *
  *   |<---------- CMSG_SPACE() --------->|<---------- CMSG_SPACE() --------->|
  *   |                                   |                                   |
  *
  *   |<---------- cmsg_len ---------->|  |<--------- cmsg_len ----------->|  |
  *
  *   |<--------- CMSG_LEN() --------->|  |<-------- CMSG_LEN() ---------->|  |
  *   |                                |  |                                |  |
  *
  *   +-----+-----+-----+--+-----------+--+-----+-----+-----+--+-----------+--+
  *   |cmsg_|cmsg_|cmsg_|XX|           |XX|cmsg_|cmsg_|cmsg_|XX|           |XX|
  *
  *   |len  |level|type |XX|cmsg_data[]|XX|len  |level|type |XX|cmsg_data[]|XX|
  *
  *   +-----+-----+-----+--+-----------+--+-----+-----+-----+--+-----------+--+
  *    ^
  *    |
  *
  * msg_control
  * points here
  */
 static int sctp_msghdr_parse(const struct msghdr *msg, struct sctp_cmsgs *cmsgs)
 {
     struct msghdr *my_msg = (struct msghdr *)msg;
     struct cmsghdr *cmsg;
 
     for_each_cmsghdr(cmsg, my_msg) {
         if (!CMSG_OK(my_msg, cmsg))
             return -EINVAL;
 
         /* Should we parse this header or ignore?  */
         if (cmsg->cmsg_level != IPPROTO_SCTP)
             continue;
 
         /* Strictly check lengths following example in SCM code.  */
         switch (cmsg->cmsg_type) {
         case SCTP_INIT:
             /* SCTP Socket API Extension
              * 5.3.1 SCTP Initiation Structure (SCTP_INIT)
              *
              * This cmsghdr structure provides information for
              * initializing new SCTP associations with sendmsg().
              * The SCTP_INITMSG socket option uses this same data
              * structure.  This structure is not used for
              * recvmsg().
              *
              * cmsg_level    cmsg_type      cmsg_data[]
              * ------------  ------------   ----------------------
              * IPPROTO_SCTP  SCTP_INIT      struct sctp_initmsg
              */
             if (cmsg->cmsg_len != CMSG_LEN(sizeof(struct sctp_initmsg)))
                 return -EINVAL;
 
             cmsgs->init = CMSG_DATA(cmsg);
             break;
 
         case SCTP_SNDRCV:
             /* SCTP Socket API Extension
              * 5.3.2 SCTP Header Information Structure(SCTP_SNDRCV)
              *
              * This cmsghdr structure specifies SCTP options for
              * sendmsg() and describes SCTP header information
              * about a received message through recvmsg().
              *
              * cmsg_level    cmsg_type      cmsg_data[]
              * ------------  ------------   ----------------------
              * IPPROTO_SCTP  SCTP_SNDRCV    struct sctp_sndrcvinfo
              */
             if (cmsg->cmsg_len != CMSG_LEN(sizeof(struct sctp_sndrcvinfo)))
                 return -EINVAL;
 
             cmsgs->srinfo = CMSG_DATA(cmsg);
 
             if (cmsgs->srinfo->sinfo_flags &
                 ~(SCTP_UNORDERED | SCTP_ADDR_OVER |
                   SCTP_SACK_IMMEDIATELY | SCTP_SENDALL |
                   SCTP_PR_SCTP_MASK | SCTP_ABORT | SCTP_EOF))
                 return -EINVAL;
             break;
 
         case SCTP_SNDINFO:
             /* SCTP Socket API Extension
              * 5.3.4 SCTP Send Information Structure (SCTP_SNDINFO)
              *
              * This cmsghdr structure specifies SCTP options for
              * sendmsg(). This structure and SCTP_RCVINFO replaces
              * SCTP_SNDRCV which has been deprecated.
              *
              * cmsg_level    cmsg_type      cmsg_data[]
              * ------------  ------------   ---------------------
              * IPPROTO_SCTP  SCTP_SNDINFO    struct sctp_sndinfo
              */
             if (cmsg->cmsg_len != CMSG_LEN(sizeof(struct sctp_sndinfo)))
                 return -EINVAL;
 
             cmsgs->sinfo = CMSG_DATA(cmsg);
 
             if (cmsgs->sinfo->snd_flags &
                 ~(SCTP_UNORDERED | SCTP_ADDR_OVER |
                   SCTP_SACK_IMMEDIATELY | SCTP_SENDALL |
                   SCTP_PR_SCTP_MASK | SCTP_ABORT | SCTP_EOF))
                 return -EINVAL;
             break;
         case SCTP_PRINFO:
             /* SCTP Socket API Extension
              * 5.3.7 SCTP PR-SCTP Information Structure (SCTP_PRINFO)
              *
              * This cmsghdr structure specifies SCTP options for sendmsg().
              *
              * cmsg_level    cmsg_type      cmsg_data[]
              * ------------  ------------   ---------------------
              * IPPROTO_SCTP  SCTP_PRINFO    struct sctp_prinfo
              */
             if (cmsg->cmsg_len != CMSG_LEN(sizeof(struct sctp_prinfo)))
                 return -EINVAL;
 
             cmsgs->prinfo = CMSG_DATA(cmsg);
             if (cmsgs->prinfo->pr_policy & ~SCTP_PR_SCTP_MASK)
                 return -EINVAL;
 
             if (cmsgs->prinfo->pr_policy == SCTP_PR_SCTP_NONE)
                 cmsgs->prinfo->pr_value = 0;
             break;
         case SCTP_AUTHINFO:
             /* SCTP Socket API Extension
              * 5.3.8 SCTP AUTH Information Structure (SCTP_AUTHINFO)
              *
              * This cmsghdr structure specifies SCTP options for sendmsg().
              *
              * cmsg_level    cmsg_type      cmsg_data[]
              * ------------  ------------   ---------------------
              * IPPROTO_SCTP  SCTP_AUTHINFO  struct sctp_authinfo
              */
             if (cmsg->cmsg_len != CMSG_LEN(sizeof(struct sctp_authinfo)))
                 return -EINVAL;
 
             cmsgs->authinfo = CMSG_DATA(cmsg);
             break;
         case SCTP_DSTADDRV4:
         case SCTP_DSTADDRV6:
             /* SCTP Socket API Extension
              * 5.3.9/10 SCTP Destination IPv4/6 Address Structure (SCTP_DSTADDRV4/6)
              *
              * This cmsghdr structure specifies SCTP options for sendmsg().
              *
              * cmsg_level    cmsg_type         cmsg_data[]
              * ------------  ------------   ---------------------
              * IPPROTO_SCTP  SCTP_DSTADDRV4 struct in_addr
              * ------------  ------------   ---------------------
              * IPPROTO_SCTP  SCTP_DSTADDRV6 struct in6_addr
              */
             cmsgs->addrs_msg = my_msg;
             break;
         default:
             return -EINVAL;
         }
     }
 
     return 0;
 }
 
 /*
  * Wait for a packet..
  * Note: This function is the same function as in core/datagram.c
  * with a few modifications to make lksctp work.
  */
 static int sctp_wait_for_packet(struct sock *sk, int *err, long *timeo_p)
 {
     int error;
     DEFINE_WAIT(wait);
 
     prepare_to_wait_exclusive(sk_sleep(sk), &wait, TASK_INTERRUPTIBLE);
 
     /* Socket errors? */
     error = sock_error(sk);
     if (error)
         goto out;
 
     if (!skb_queue_empty(&sk->sk_receive_queue))
         goto ready;
 
     /* Socket shut down?  */
     if (sk->sk_shutdown & RCV_SHUTDOWN)
         goto out;
 
     /* Sequenced packets can come disconnected.  If so we report the
      * problem.
      */
     error = -ENOTCONN;
 
     /* Is there a good reason to think that we may receive some data?  */
     if (list_empty(&sctp_sk(sk)->ep->asocs) && !sctp_sstate(sk, LISTENING))
         goto out;
 
     /* Handle signals.  */
     if (signal_pending(current))
         goto interrupted;
 
     /* Let another process have a go.  Since we are going to sleep
      * anyway.  Note: This may cause odd behaviors if the message
      * does not fit in the user's buffer, but this seems to be the
      * only way to honor MSG_DONTWAIT realistically.
      */
     release_sock(sk);
     *timeo_p = schedule_timeout(*timeo_p);
     lock_sock(sk);
 
 ready:
     finish_wait(sk_sleep(sk), &wait);
     return 0;
 
 interrupted:
     error = sock_intr_errno(*timeo_p);
 
 out:
     finish_wait(sk_sleep(sk), &wait);
     *err = error;
     return error;
 }
 
 /* Receive a datagram.
  * Note: This is pretty much the same routine as in core/datagram.c
  * with a few changes to make lksctp work.
  */
 struct sk_buff *sctp_skb_recv_datagram(struct sock *sk, int flags, int *err)
 {
     int error;
     struct sk_buff *skb;
     long timeo;
 
     timeo = sock_rcvtimeo(sk, flags & MSG_DONTWAIT);
 
     pr_debug("%s: timeo:%ld, max:%ld\n", __func__, timeo,
          MAX_SCHEDULE_TIMEOUT);
 
     do {
         /* Again only user level code calls this function,
          * so nothing interrupt level
          * will suddenly eat the receive_queue.
          *
          *  Look at current nfs client by the way...
          *  However, this function was correct in any case. 8)
          */
         if (flags & MSG_PEEK) {
             skb = skb_peek(&sk->sk_receive_queue);
             if (skb)
                 refcount_inc(&skb->users);
         } else {
             skb = __skb_dequeue(&sk->sk_receive_queue);
         }
 
         if (skb)
             return skb;
 
         /* Caller is allowed not to check sk->sk_err before calling. */
         error = sock_error(sk);
         if (error)
             goto no_packet;
 
         if (sk->sk_shutdown & RCV_SHUTDOWN)
             break;
 
         if (sk_can_busy_loop(sk)) {
             sk_busy_loop(sk, flags & MSG_DONTWAIT);
 
             if (!skb_queue_empty_lockless(&sk->sk_receive_queue))
                 continue;
         }
 
         /* User doesn't want to wait.  */
         error = -EAGAIN;
         if (!timeo)
             goto no_packet;
     } while (sctp_wait_for_packet(sk, err, &timeo) == 0);
 
     return NULL;
 
 no_packet:
     *err = error;
     return NULL;
 }
 
 /* If sndbuf has changed, wake up per association sndbuf waiters.  */
 static void __sctp_write_space(struct sctp_association *asoc)
 {
     struct sock *sk = asoc->base.sk;
 
     if (sctp_wspace(asoc) <= 0)
         return;
 
     if (waitqueue_active(&asoc->wait))
         wake_up_interruptible(&asoc->wait);
 
     if (sctp_writeable(sk)) {
         struct socket_wq *wq;
 
         rcu_read_lock();
         wq = rcu_dereference(sk->sk_wq);
         if (wq) {
             if (waitqueue_active(&wq->wait))
                 wake_up_interruptible(&wq->wait);
 
             /* Note that we try to include the Async I/O support
              * here by modeling from the current TCP/UDP code.
              * We have not tested with it yet.
              */
             if (!(sk->sk_shutdown & SEND_SHUTDOWN))
                 sock_wake_async(wq, SOCK_WAKE_SPACE, POLL_OUT);
         }
         rcu_read_unlock();
     }
 }
 
 static void sctp_wake_up_waiters(struct sock *sk,
                  struct sctp_association *asoc)
 {
     struct sctp_association *tmp = asoc;
 
     /* We do accounting for the sndbuf space per association,
      * so we only need to wake our own association.
      */
     if (asoc->ep->sndbuf_policy)
         return __sctp_write_space(asoc);
 
     /* If association goes down and is just flushing its
      * outq, then just normally notify others.
      */
     if (asoc->base.dead)
         return sctp_write_space(sk);
 
     /* Accounting for the sndbuf space is per socket, so we
      * need to wake up others, try to be fair and in case of
      * other associations, let them have a go first instead
      * of just doing a sctp_write_space() call.
      *
      * Note that we reach sctp_wake_up_waiters() only when
      * associations free up queued chunks, thus we are under
      * lock and the list of associations on a socket is
      * guaranteed not to change.
      */
     for (tmp = list_next_entry(tmp, asocs); 1;
          tmp = list_next_entry(tmp, asocs)) {
         /* Manually skip the head element. */
         if (&tmp->asocs == &((sctp_sk(sk))->ep->asocs))
             continue;
         /* Wake up association. */
         __sctp_write_space(tmp);
         /* We've reached the end. */
         if (tmp == asoc)
             break;
     }
 }
 
 /* Do accounting for the sndbuf space.
  * Decrement the used sndbuf space of the corresponding association by the
  * data size which was just transmitted(freed).
  */
 static void sctp_wfree(struct sk_buff *skb)
 {
     struct sctp_chunk *chunk = skb_shinfo(skb)->destructor_arg;
     struct sctp_association *asoc = chunk->asoc;
     struct sock *sk = asoc->base.sk;
 
     sk_mem_uncharge(sk, skb->truesize);
     sk->sk_wmem_queued -= skb->truesize + sizeof(struct sctp_chunk);
     asoc->sndbuf_used -= skb->truesize + sizeof(struct sctp_chunk);
     WARN_ON(refcount_sub_and_test(sizeof(struct sctp_chunk),
                       &sk->sk_wmem_alloc));
 
     if (chunk->shkey) {
         struct sctp_shared_key *shkey = chunk->shkey;
 
         /* refcnt == 2 and !list_empty mean after this release, it's
          * not being used anywhere, and it's time to notify userland
          * that this shkey can be freed if it's been deactivated.
          */
         if (shkey->deactivated && !list_empty(&shkey->key_list) &&
             refcount_read(&shkey->refcnt) == 2) {
             struct sctp_ulpevent *ev;
 
             ev = sctp_ulpevent_make_authkey(asoc, shkey->key_id,
                             SCTP_AUTH_FREE_KEY,
                             GFP_KERNEL);
             if (ev)
                 asoc->stream.si->enqueue_event(&asoc->ulpq, ev);
         }
         sctp_auth_shkey_release(chunk->shkey);
     }
 
     sock_wfree(skb);
     sctp_wake_up_waiters(sk, asoc);
 
     sctp_association_put(asoc);
 }
 
 /* Do accounting for the receive space on the socket.
  * Accounting for the association is done in ulpevent.c
  * We set this as a destructor for the cloned data skbs so that
  * accounting is done at the correct time.
  */
 void sctp_sock_rfree(struct sk_buff *skb)
 {
     struct sock *sk = skb->sk;
     struct sctp_ulpevent *event = sctp_skb2event(skb);
 
     atomic_sub(event->rmem_len, &sk->sk_rmem_alloc);
 
     /*
      * Mimic the behavior of sock_rfree
      */
     sk_mem_uncharge(sk, event->rmem_len);
 }
 
 
 /* Helper function to wait for space in the sndbuf.  */
 static int sctp_wait_for_sndbuf(struct sctp_association *asoc, long *timeo_p,
                 size_t msg_len)
 {
     struct sock *sk = asoc->base.sk;
     long current_timeo = *timeo_p;
     DEFINE_WAIT(wait);
     int err = 0;
 
     pr_debug("%s: asoc:%p, timeo:%ld, msg_len:%zu\n", __func__, asoc,
          *timeo_p, msg_len);
 
     /* Increment the association's refcnt.  */
     sctp_association_hold(asoc);
 
     /* Wait on the association specific sndbuf space. */
     for (;;) {
         prepare_to_wait_exclusive(&asoc->wait, &wait,
                       TASK_INTERRUPTIBLE);
         if (asoc->base.dead)
             goto do_dead;
         if (!*timeo_p)
             goto do_nonblock;
         if (sk->sk_err || asoc->state >= SCTP_STATE_SHUTDOWN_PENDING)
             goto do_error;
         if (signal_pending(current))
             goto do_interrupted;
         if ((int)msg_len <= sctp_wspace(asoc) &&
             sk_wmem_schedule(sk, msg_len))
             break;
 
         /* Let another process have a go.  Since we are going
          * to sleep anyway.
          */
         release_sock(sk);
         current_timeo = schedule_timeout(current_timeo);
         lock_sock(sk);
         if (sk != asoc->base.sk)
             goto do_error;
 
         *timeo_p = current_timeo;
     }
 
 out:
     finish_wait(&asoc->wait, &wait);
 
     /* Release the association's refcnt.  */
     sctp_association_put(asoc);
 
     return err;
 
 do_dead:
     err = -ESRCH;
     goto out;
 
 do_error:
     err = -EPIPE;
     goto out;
 
 do_interrupted:
     err = sock_intr_errno(*timeo_p);
     goto out;
 
 do_nonblock:
     err = -EAGAIN;
     goto out;
 }
 
 void sctp_data_ready(struct sock *sk)
 {
     struct socket_wq *wq;
 
     rcu_read_lock();
     wq = rcu_dereference(sk->sk_wq);
     if (skwq_has_sleeper(wq))
         wake_up_interruptible_sync_poll(&wq->wait, EPOLLIN |
                         EPOLLRDNORM | EPOLLRDBAND);
     sk_wake_async(sk, SOCK_WAKE_WAITD, POLL_IN);
     rcu_read_unlock();
 }
 
 /* If socket sndbuf has changed, wake up all per association waiters.  */
 void sctp_write_space(struct sock *sk)
 {
     struct sctp_association *asoc;
 
     /* Wake up the tasks in each wait queue.  */
     list_for_each_entry(asoc, &((sctp_sk(sk))->ep->asocs), asocs) {
         __sctp_write_space(asoc);
     }
 }
 
 /* Is there any sndbuf space available on the socket?
  *
  * Note that sk_wmem_alloc is the sum of the send buffers on all of the
  * associations on the same socket.  For a UDP-style socket with
  * multiple associations, it is possible for it to be "unwriteable"
  * prematurely.  I assume that this is acceptable because
  * a premature "unwriteable" is better than an accidental "writeable" which
  * would cause an unwanted block under certain circumstances.  For the 1-1
  * UDP-style sockets or TCP-style sockets, this code should work.
  *  - Daisy
  */
 static bool sctp_writeable(struct sock *sk)
 {
     return sk->sk_sndbuf > sk->sk_wmem_queued;
 }
 
 /* Wait for an association to go into ESTABLISHED state. If timeout is 0,
  * returns immediately with EINPROGRESS.
  */
 static int sctp_wait_for_connect(struct sctp_association *asoc, long *timeo_p)
 {
     struct sock *sk = asoc->base.sk;
     int err = 0;
     long current_timeo = *timeo_p;
     DEFINE_WAIT(wait);
 
     pr_debug("%s: asoc:%p, timeo:%ld\n", __func__, asoc, *timeo_p);
 
     /* Increment the association's refcnt.  */
     sctp_association_hold(asoc);
 
     for (;;) {
         prepare_to_wait_exclusive(&asoc->wait, &wait,
                       TASK_INTERRUPTIBLE);
         if (!*timeo_p)
             goto do_nonblock;
         if (sk->sk_shutdown & RCV_SHUTDOWN)
             break;
         if (sk->sk_err || asoc->state >= SCTP_STATE_SHUTDOWN_PENDING ||
             asoc->base.dead)
             goto do_error;
         if (signal_pending(current))
             goto do_interrupted;
 
         if (sctp_state(asoc, ESTABLISHED))
             break;
 
         /* Let another process have a go.  Since we are going
          * to sleep anyway.
          */
         release_sock(sk);
         current_timeo = schedule_timeout(current_timeo);
         lock_sock(sk);
 
         *timeo_p = current_timeo;
     }
 
 out:
     finish_wait(&asoc->wait, &wait);
 
     /* Release the association's refcnt.  */
     sctp_association_put(asoc);
 
     return err;
 
 do_error:
     if (asoc->init_err_counter + 1 > asoc->max_init_attempts)
         err = -ETIMEDOUT;
     else
         err = -ECONNREFUSED;
     goto out;
 
 do_interrupted:
     err = sock_intr_errno(*timeo_p);
     goto out;
 
 do_nonblock:
     err = -EINPROGRESS;
     goto out;
 }
 
 static int sctp_wait_for_accept(struct sock *sk, long timeo)
 {
     struct sctp_endpoint *ep;
     int err = 0;
     DEFINE_WAIT(wait);
 
     ep = sctp_sk(sk)->ep;
 
 
     for (;;) {
         prepare_to_wait_exclusive(sk_sleep(sk), &wait,
                       TASK_INTERRUPTIBLE);
 
         if (list_empty(&ep->asocs)) {
             release_sock(sk);
             timeo = schedule_timeout(timeo);
             lock_sock(sk);
         }
 
         err = -EINVAL;
         if (!sctp_sstate(sk, LISTENING))
             break;
 
         err = 0;
         if (!list_empty(&ep->asocs))
             break;
 
         err = sock_intr_errno(timeo);
         if (signal_pending(current))
             break;
 
         err = -EAGAIN;
         if (!timeo)
             break;
     }
 
     finish_wait(sk_sleep(sk), &wait);
 
     return err;
 }
 
 static void sctp_wait_for_close(struct sock *sk, long timeout)
 {
     DEFINE_WAIT(wait);
 
     do {
         prepare_to_wait(sk_sleep(sk), &wait, TASK_INTERRUPTIBLE);
         if (list_empty(&sctp_sk(sk)->ep->asocs))
             break;
         release_sock(sk);
         timeout = schedule_timeout(timeout);
         lock_sock(sk);
     } while (!signal_pending(current) && timeout);
 
     finish_wait(sk_sleep(sk), &wait);
 }
 
 static void sctp_skb_set_owner_r_frag(struct sk_buff *skb, struct sock *sk)
 {
     struct sk_buff *frag;
 
     if (!skb->data_len)
         goto done;
 
     /* Don't forget the fragments. */
     skb_walk_frags(skb, frag)
         sctp_skb_set_owner_r_frag(frag, sk);
 
 done:
     sctp_skb_set_owner_r(skb, sk);
 }
 
 void sctp_copy_sock(struct sock *newsk, struct sock *sk,
             struct sctp_association *asoc)
 {
     struct inet_sock *inet = inet_sk(sk);
     struct inet_sock *newinet;
     struct sctp_sock *sp = sctp_sk(sk);
 
     newsk->sk_type = sk->sk_type;
     newsk->sk_bound_dev_if = sk->sk_bound_dev_if;
     newsk->sk_flags = sk->sk_flags;
     newsk->sk_tsflags = sk->sk_tsflags;
     newsk->sk_no_check_tx = sk->sk_no_check_tx;
     newsk->sk_no_check_rx = sk->sk_no_check_rx;
     newsk->sk_reuse = sk->sk_reuse;
     sctp_sk(newsk)->reuse = sp->reuse;
 
     newsk->sk_shutdown = sk->sk_shutdown;
     newsk->sk_destruct = sctp_destruct_sock;
     newsk->sk_family = sk->sk_family;
     newsk->sk_protocol = IPPROTO_SCTP;
     newsk->sk_backlog_rcv = sk->sk_prot->backlog_rcv;
     newsk->sk_sndbuf = sk->sk_sndbuf;
     newsk->sk_rcvbuf = sk->sk_rcvbuf;
     newsk->sk_lingertime = sk->sk_lingertime;
     newsk->sk_rcvtimeo = sk->sk_rcvtimeo;
     newsk->sk_sndtimeo = sk->sk_sndtimeo;
     newsk->sk_rxhash = sk->sk_rxhash;
 
     newinet = inet_sk(newsk);
 
     /* Initialize sk's sport, dport, rcv_saddr and daddr for
      * getsockname() and getpeername()
      */
     newinet->inet_sport = inet->inet_sport;
     newinet->inet_saddr = inet->inet_saddr;
     newinet->inet_rcv_saddr = inet->inet_rcv_saddr;
     newinet->inet_dport = htons(asoc->peer.port);
     newinet->pmtudisc = inet->pmtudisc;
     newinet->inet_id = prandom_u32();
 
     newinet->uc_ttl = inet->uc_ttl;
     newinet->mc_loop = 1;
     newinet->mc_ttl = 1;
     newinet->mc_index = 0;
     newinet->mc_list = NULL;
 
     if (newsk->sk_flags & SK_FLAGS_TIMESTAMP)
         net_enable_timestamp();
 
     /* Set newsk security attributes from original sk and connection
      * security attribute from asoc.
      */
     security_sctp_sk_clone(asoc, sk, newsk);
 }
 
 static inline void sctp_copy_descendant(struct sock *sk_to,
                     const struct sock *sk_from)
 {
     size_t ancestor_size = sizeof(struct inet_sock);
 
     ancestor_size += sk_from->sk_prot->obj_size;
     ancestor_size -= offsetof(struct sctp_sock, pd_lobby);
     __inet_sk_copy_descendant(sk_to, sk_from, ancestor_size);
 }
 
 /* Populate the fields of the newsk from the oldsk and migrate the assoc
  * and its messages to the newsk.
  */
 static int sctp_sock_migrate(struct sock *oldsk, struct sock *newsk,
                  struct sctp_association *assoc,
                  enum sctp_socket_type type)
 {
     struct sctp_sock *oldsp = sctp_sk(oldsk);
     struct sctp_sock *newsp = sctp_sk(newsk);
     struct sctp_bind_bucket *pp; /* hash list port iterator */
     struct sctp_endpoint *newep = newsp->ep;
     struct sk_buff *skb, *tmp;
     struct sctp_ulpevent *event;
     struct sctp_bind_hashbucket *head;
     int err;
 
     /* Migrate socket buffer sizes and all the socket level options to the
      * new socket.
      */
     newsk->sk_sndbuf = oldsk->sk_sndbuf;
     newsk->sk_rcvbuf = oldsk->sk_rcvbuf;
     /* Brute force copy old sctp opt. */
     sctp_copy_descendant(newsk, oldsk);
 
     /* Restore the ep value that was overwritten with the above structure
      * copy.
      */
     newsp->ep = newep;
     newsp->hmac = NULL;
 
     /* Hook this new socket in to the bind_hash list. */
     head = &sctp_port_hashtable[sctp_phashfn(sock_net(oldsk),
                          inet_sk(oldsk)->inet_num)];
     spin_lock_bh(&head->lock);
     pp = sctp_sk(oldsk)->bind_hash;
     sk_add_bind_node(newsk, &pp->owner);
     sctp_sk(newsk)->bind_hash = pp;
     inet_sk(newsk)->inet_num = inet_sk(oldsk)->inet_num;
     spin_unlock_bh(&head->lock);
 
     /* Copy the bind_addr list from the original endpoint to the new
      * endpoint so that we can handle restarts properly
      */
     err = sctp_bind_addr_dup(&newsp->ep->base.bind_addr,
                  &oldsp->ep->base.bind_addr, GFP_KERNEL);
     if (err)
         return err;
 
     /* New ep's auth_hmacs should be set if old ep's is set, in case
      * that net->sctp.auth_enable has been changed to 0 by users and
      * new ep's auth_hmacs couldn't be set in sctp_endpoint_init().
      */
     if (oldsp->ep->auth_hmacs) {
         err = sctp_auth_init_hmacs(newsp->ep, GFP_KERNEL);
         if (err)
             return err;
     }
 
     sctp_auto_asconf_init(newsp);
 
     /* Move any messages in the old socket's receive queue that are for the
      * peeled off association to the new socket's receive queue.
      */
     sctp_skb_for_each(skb, &oldsk->sk_receive_queue, tmp) {
         event = sctp_skb2event(skb);
         if (event->asoc == assoc) {
             __skb_unlink(skb, &oldsk->sk_receive_queue);
             __skb_queue_tail(&newsk->sk_receive_queue, skb);
             sctp_skb_set_owner_r_frag(skb, newsk);
         }
     }
 
     /* Clean up any messages pending delivery due to partial
      * delivery.   Three cases:
      * 1) No partial deliver;  no work.
      * 2) Peeling off partial delivery; keep pd_lobby in new pd_lobby.
      * 3) Peeling off non-partial delivery; move pd_lobby to receive_queue.
      */
     atomic_set(&sctp_sk(newsk)->pd_mode, assoc->ulpq.pd_mode);
 
     if (atomic_read(&sctp_sk(oldsk)->pd_mode)) {
         struct sk_buff_head *queue;
 
         /* Decide which queue to move pd_lobby skbs to. */
         if (assoc->ulpq.pd_mode) {
             queue = &newsp->pd_lobby;
         } else
             queue = &newsk->sk_receive_queue;
 
         /* Walk through the pd_lobby, looking for skbs that
          * need moved to the new socket.
          */
         sctp_skb_for_each(skb, &oldsp->pd_lobby, tmp) {
             event = sctp_skb2event(skb);
             if (event->asoc == assoc) {
                 __skb_unlink(skb, &oldsp->pd_lobby);
                 __skb_queue_tail(queue, skb);
                 sctp_skb_set_owner_r_frag(skb, newsk);
             }
         }
 
         /* Clear up any skbs waiting for the partial
          * delivery to finish.
          */
         if (assoc->ulpq.pd_mode)
             sctp_clear_pd(oldsk, NULL);
 
     }
 
     sctp_for_each_rx_skb(assoc, newsk, sctp_skb_set_owner_r_frag);
 
     /* Set the type of socket to indicate that it is peeled off from the
      * original UDP-style socket or created with the accept() call on a
      * TCP-style socket..
      */
     newsp->type = type;
 
     /* Mark the new socket "in-use" by the user so that any packets
      * that may arrive on the association after we've moved it are
      * queued to the backlog.  This prevents a potential race between
      * backlog processing on the old socket and new-packet processing
      * on the new socket.
      *
      * The caller has just allocated newsk so we can guarantee that other
      * paths won't try to lock it and then oldsk.
      */
     lock_sock_nested(newsk, SINGLE_DEPTH_NESTING);
     sctp_for_each_tx_datachunk(assoc, true, sctp_clear_owner_w);
     sctp_assoc_migrate(assoc, newsk);
     sctp_for_each_tx_datachunk(assoc, false, sctp_set_owner_w);
 
     /* If the association on the newsk is already closed before accept()
      * is called, set RCV_SHUTDOWN flag.
      */
     if (sctp_state(assoc, CLOSED) && sctp_style(newsk, TCP)) {
         inet_sk_set_state(newsk, SCTP_SS_CLOSED);
         newsk->sk_shutdown |= RCV_SHUTDOWN;
     } else {
         inet_sk_set_state(newsk, SCTP_SS_ESTABLISHED);
     }
 
     release_sock(newsk);
 
     return 0;
 }
 
 
 /* This proto struct describes the ULP interface for SCTP.  */
 struct proto sctp_prot = {
     .name        =  "SCTP",
     .owner       =  THIS_MODULE,
     .close       =  sctp_close,
     .disconnect  =  sctp_disconnect,
     .accept      =  sctp_accept,
     .ioctl       =  sctp_ioctl,
     .init        =  sctp_init_sock,
     .destroy     =  sctp_destroy_sock,
     .shutdown    =  sctp_shutdown,
     .setsockopt  =  sctp_setsockopt,
     .getsockopt  =  sctp_getsockopt,
     .sendmsg     =  sctp_sendmsg,
     .recvmsg     =  sctp_recvmsg,
     .bind        =  sctp_bind,
     .bind_add    =  sctp_bind_add,
     .backlog_rcv =  sctp_backlog_rcv,
     .hash        =  sctp_hash,
     .unhash      =  sctp_unhash,
     .no_autobind =  true,
     .obj_size    =  sizeof(struct sctp_sock),
     .useroffset  =  offsetof(struct sctp_sock, subscribe),
     .usersize    =  offsetof(struct sctp_sock, initmsg) -
                 offsetof(struct sctp_sock, subscribe) +
                 sizeof_field(struct sctp_sock, initmsg),
     .sysctl_mem  =  sysctl_sctp_mem,
     .sysctl_rmem =  sysctl_sctp_rmem,
     .sysctl_wmem =  sysctl_sctp_wmem,
     .memory_pressure = &sctp_memory_pressure,
     .enter_memory_pressure = sctp_enter_memory_pressure,
 
     .memory_allocated = &sctp_memory_allocated,
     .per_cpu_fw_alloc = &sctp_memory_per_cpu_fw_alloc,
 
     .sockets_allocated = &sctp_sockets_allocated,
 };
 
 #if IS_ENABLED(CONFIG_IPV6)
 
 #include <net/transp_v6.h>
 static void sctp_v6_destroy_sock(struct sock *sk)
 {
     sctp_destroy_sock(sk);
     inet6_destroy_sock(sk);
 }
 
 struct proto sctpv6_prot = {
     .name       = "SCTPv6",
     .owner      = THIS_MODULE,
     .close      = sctp_close,
     .disconnect = sctp_disconnect,
     .accept     = sctp_accept,
     .ioctl      = sctp_ioctl,
     .init       = sctp_init_sock,
     .destroy    = sctp_v6_destroy_sock,
     .shutdown   = sctp_shutdown,
     .setsockopt = sctp_setsockopt,
     .getsockopt = sctp_getsockopt,
     .sendmsg    = sctp_sendmsg,
     .recvmsg    = sctp_recvmsg,
     .bind       = sctp_bind,
     .bind_add   = sctp_bind_add,
     .backlog_rcv    = sctp_backlog_rcv,
     .hash       = sctp_hash,
     .unhash     = sctp_unhash,
     .no_autobind    = true,
     .obj_size   = sizeof(struct sctp6_sock),
     .useroffset = offsetof(struct sctp6_sock, sctp.subscribe),
     .usersize   = offsetof(struct sctp6_sock, sctp.initmsg) -
                 offsetof(struct sctp6_sock, sctp.subscribe) +
                 sizeof_field(struct sctp6_sock, sctp.initmsg),
     .sysctl_mem = sysctl_sctp_mem,
     .sysctl_rmem    = sysctl_sctp_rmem,
     .sysctl_wmem    = sysctl_sctp_wmem,
     .memory_pressure = &sctp_memory_pressure,
     .enter_memory_pressure = sctp_enter_memory_pressure,
 
     .memory_allocated = &sctp_memory_allocated,
     .per_cpu_fw_alloc = &sctp_memory_per_cpu_fw_alloc,
 
     .sockets_allocated = &sctp_sockets_allocated,
 };
 #endif /* IS_ENABLED(CONFIG_IPV6) */