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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 Intel Corp.
  * Copyright (c) 2001 Nokia, Inc.
  * Copyright (c) 2001 La Monte H.P. Yarroll
  *
  * These functions manipulate an sctp event.   The struct ulpevent is used
  * to carry notifications and data to the ULP (sockets).
  *
  * 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:
  *    Jon Grimm             <jgrimm@us.ibm.com>
  *    La Monte H.P. Yarroll <piggy@acm.org>
  *    Ardelle Fan       <ardelle.fan@intel.com>
  *    Sridhar Samudrala     <sri@us.ibm.com>
  */
 
 #include <linux/slab.h>
 #include <linux/types.h>
 #include <linux/skbuff.h>
 #include <net/sctp/structs.h>
 #include <net/sctp/sctp.h>
 #include <net/sctp/sm.h>
 
 static void sctp_ulpevent_receive_data(struct sctp_ulpevent *event,
                        struct sctp_association *asoc);
 static void sctp_ulpevent_release_data(struct sctp_ulpevent *event);
 static void sctp_ulpevent_release_frag_data(struct sctp_ulpevent *event);
 
 
 /* Initialize an ULP event from an given skb.  */
 static void sctp_ulpevent_init(struct sctp_ulpevent *event,
                    __u16 msg_flags,
                    unsigned int len)
 {
     memset(event, 0, sizeof(struct sctp_ulpevent));
     event->msg_flags = msg_flags;
     event->rmem_len = len;
 }
 
 /* Create a new sctp_ulpevent.  */
 static struct sctp_ulpevent *sctp_ulpevent_new(int size, __u16 msg_flags,
                            gfp_t gfp)
 {
     struct sctp_ulpevent *event;
     struct sk_buff *skb;
 
     skb = alloc_skb(size, gfp);
     if (!skb)
         goto fail;
 
     event = sctp_skb2event(skb);
     sctp_ulpevent_init(event, msg_flags, skb->truesize);
 
     return event;
 
 fail:
     return NULL;
 }
 
 /* Is this a MSG_NOTIFICATION?  */
 int sctp_ulpevent_is_notification(const struct sctp_ulpevent *event)
 {
     return MSG_NOTIFICATION == (event->msg_flags & MSG_NOTIFICATION);
 }
 
 /* Hold the association in case the msg_name needs read out of
  * the association.
  */
 static inline void sctp_ulpevent_set_owner(struct sctp_ulpevent *event,
                        const struct sctp_association *asoc)
 {
     struct sctp_chunk *chunk = event->chunk;
     struct sk_buff *skb;
 
     /* Cast away the const, as we are just wanting to
      * bump the reference count.
      */
     sctp_association_hold((struct sctp_association *)asoc);
     skb = sctp_event2skb(event);
     event->asoc = (struct sctp_association *)asoc;
     atomic_add(event->rmem_len, &event->asoc->rmem_alloc);
     sctp_skb_set_owner_r(skb, asoc->base.sk);
     if (chunk && chunk->head_skb && !chunk->head_skb->sk)
         chunk->head_skb->sk = asoc->base.sk;
 }
 
 /* A simple destructor to give up the reference to the association. */
 static inline void sctp_ulpevent_release_owner(struct sctp_ulpevent *event)
 {
     struct sctp_association *asoc = event->asoc;
 
     atomic_sub(event->rmem_len, &asoc->rmem_alloc);
     sctp_association_put(asoc);
 }
 
 /* Create and initialize an SCTP_ASSOC_CHANGE event.
  *
  * 5.3.1.1 SCTP_ASSOC_CHANGE
  *
  * Communication notifications inform the ULP that an SCTP association
  * has either begun or ended. The identifier for a new association is
  * provided by this notification.
  *
  * Note: There is no field checking here.  If a field is unused it will be
  * zero'd out.
  */
 struct sctp_ulpevent  *sctp_ulpevent_make_assoc_change(
     const struct sctp_association *asoc,
     __u16 flags, __u16 state, __u16 error, __u16 outbound,
     __u16 inbound, struct sctp_chunk *chunk, gfp_t gfp)
 {
     struct sctp_ulpevent *event;
     struct sctp_assoc_change *sac;
     struct sk_buff *skb;
 
     /* If the lower layer passed in the chunk, it will be
      * an ABORT, so we need to include it in the sac_info.
      */
     if (chunk) {
         /* Copy the chunk data to a new skb and reserve enough
          * head room to use as notification.
          */
         skb = skb_copy_expand(chunk->skb,
                       sizeof(struct sctp_assoc_change), 0, gfp);
 
         if (!skb)
             goto fail;
 
         /* Embed the event fields inside the cloned skb.  */
         event = sctp_skb2event(skb);
         sctp_ulpevent_init(event, MSG_NOTIFICATION, skb->truesize);
 
         /* Include the notification structure */
         sac = skb_push(skb, sizeof(struct sctp_assoc_change));
 
         /* Trim the buffer to the right length.  */
         skb_trim(skb, sizeof(struct sctp_assoc_change) +
              ntohs(chunk->chunk_hdr->length) -
              sizeof(struct sctp_chunkhdr));
     } else {
         event = sctp_ulpevent_new(sizeof(struct sctp_assoc_change),
                   MSG_NOTIFICATION, gfp);
         if (!event)
             goto fail;
 
         skb = sctp_event2skb(event);
         sac = skb_put(skb, sizeof(struct sctp_assoc_change));
     }
 
     /* Socket Extensions for SCTP
      * 5.3.1.1 SCTP_ASSOC_CHANGE
      *
      * sac_type:
      * It should be SCTP_ASSOC_CHANGE.
      */
     sac->sac_type = SCTP_ASSOC_CHANGE;
 
     /* Socket Extensions for SCTP
      * 5.3.1.1 SCTP_ASSOC_CHANGE
      *
      * sac_state: 32 bits (signed integer)
      * This field holds one of a number of values that communicate the
      * event that happened to the association.
      */
     sac->sac_state = state;
 
     /* Socket Extensions for SCTP
      * 5.3.1.1 SCTP_ASSOC_CHANGE
      *
      * sac_flags: 16 bits (unsigned integer)
      * Currently unused.
      */
     sac->sac_flags = 0;
 
     /* Socket Extensions for SCTP
      * 5.3.1.1 SCTP_ASSOC_CHANGE
      *
      * sac_length: sizeof (__u32)
      * This field is the total length of the notification data, including
      * the notification header.
      */
     sac->sac_length = skb->len;
 
     /* Socket Extensions for SCTP
      * 5.3.1.1 SCTP_ASSOC_CHANGE
      *
      * sac_error:  32 bits (signed integer)
      *
      * If the state was reached due to a error condition (e.g.
      * COMMUNICATION_LOST) any relevant error information is available in
      * this field. This corresponds to the protocol error codes defined in
      * [SCTP].
      */
     sac->sac_error = error;
 
     /* Socket Extensions for SCTP
      * 5.3.1.1 SCTP_ASSOC_CHANGE
      *
      * sac_outbound_streams:  16 bits (unsigned integer)
      * sac_inbound_streams:  16 bits (unsigned integer)
      *
      * The maximum number of streams allowed in each direction are
      * available in sac_outbound_streams and sac_inbound streams.
      */
     sac->sac_outbound_streams = outbound;
     sac->sac_inbound_streams = inbound;
 
     /* Socket Extensions for SCTP
      * 5.3.1.1 SCTP_ASSOC_CHANGE
      *
      * sac_assoc_id: sizeof (sctp_assoc_t)
      *
      * The association id field, holds the identifier for the association.
      * All notifications for a given association have the same association
      * identifier.  For TCP style socket, this field is ignored.
      */
     sctp_ulpevent_set_owner(event, asoc);
     sac->sac_assoc_id = sctp_assoc2id(asoc);
 
     return event;
 
 fail:
     return NULL;
 }
 
 /* Create and initialize an SCTP_PEER_ADDR_CHANGE event.
  *
  * Socket Extensions for SCTP - draft-01
  * 5.3.1.2 SCTP_PEER_ADDR_CHANGE
  *
  * When a destination address on a multi-homed peer encounters a change
  * an interface details event is sent.
  */
 static struct sctp_ulpevent *sctp_ulpevent_make_peer_addr_change(
     const struct sctp_association *asoc,
     const struct sockaddr_storage *aaddr,
     int flags, int state, int error, gfp_t gfp)
 {
     struct sctp_ulpevent *event;
     struct sctp_paddr_change  *spc;
     struct sk_buff *skb;
 
     event = sctp_ulpevent_new(sizeof(struct sctp_paddr_change),
                   MSG_NOTIFICATION, gfp);
     if (!event)
         goto fail;
 
     skb = sctp_event2skb(event);
     spc = skb_put(skb, sizeof(struct sctp_paddr_change));
 
     /* Sockets API Extensions for SCTP
      * Section 5.3.1.2 SCTP_PEER_ADDR_CHANGE
      *
      * spc_type:
      *
      *    It should be SCTP_PEER_ADDR_CHANGE.
      */
     spc->spc_type = SCTP_PEER_ADDR_CHANGE;
 
     /* Sockets API Extensions for SCTP
      * Section 5.3.1.2 SCTP_PEER_ADDR_CHANGE
      *
      * spc_length: sizeof (__u32)
      *
      * This field is the total length of the notification data, including
      * the notification header.
      */
     spc->spc_length = sizeof(struct sctp_paddr_change);
 
     /* Sockets API Extensions for SCTP
      * Section 5.3.1.2 SCTP_PEER_ADDR_CHANGE
      *
      * spc_flags: 16 bits (unsigned integer)
      * Currently unused.
      */
     spc->spc_flags = 0;
 
     /* Sockets API Extensions for SCTP
      * Section 5.3.1.2 SCTP_PEER_ADDR_CHANGE
      *
      * spc_state:  32 bits (signed integer)
      *
      * This field holds one of a number of values that communicate the
      * event that happened to the address.
      */
     spc->spc_state = state;
 
     /* Sockets API Extensions for SCTP
      * Section 5.3.1.2 SCTP_PEER_ADDR_CHANGE
      *
      * spc_error:  32 bits (signed integer)
      *
      * If the state was reached due to any error condition (e.g.
      * ADDRESS_UNREACHABLE) any relevant error information is available in
      * this field.
      */
     spc->spc_error = error;
 
     /* Socket Extensions for SCTP
      * 5.3.1.1 SCTP_ASSOC_CHANGE
      *
      * spc_assoc_id: sizeof (sctp_assoc_t)
      *
      * The association id field, holds the identifier for the association.
      * All notifications for a given association have the same association
      * identifier.  For TCP style socket, this field is ignored.
      */
     sctp_ulpevent_set_owner(event, asoc);
     spc->spc_assoc_id = sctp_assoc2id(asoc);
 
     /* Sockets API Extensions for SCTP
      * Section 5.3.1.2 SCTP_PEER_ADDR_CHANGE
      *
      * spc_aaddr: sizeof (struct sockaddr_storage)
      *
      * The affected address field, holds the remote peer's address that is
      * encountering the change of state.
      */
     memcpy(&spc->spc_aaddr, aaddr, sizeof(struct sockaddr_storage));
 
     /* Map ipv4 address into v4-mapped-on-v6 address.  */
     sctp_get_pf_specific(asoc->base.sk->sk_family)->addr_to_user(
                     sctp_sk(asoc->base.sk),
                     (union sctp_addr *)&spc->spc_aaddr);
 
     return event;
 
 fail:
     return NULL;
 }
 
 void sctp_ulpevent_notify_peer_addr_change(struct sctp_transport *transport,
                        int state, int error)
 {
     struct sctp_association *asoc = transport->asoc;
     struct sockaddr_storage addr;
     struct sctp_ulpevent *event;
 
     if (asoc->state < SCTP_STATE_ESTABLISHED)
         return;
 
     memset(&addr, 0, sizeof(struct sockaddr_storage));
     memcpy(&addr, &transport->ipaddr, transport->af_specific->sockaddr_len);
 
     event = sctp_ulpevent_make_peer_addr_change(asoc, &addr, 0, state,
                             error, GFP_ATOMIC);
     if (event)
         asoc->stream.si->enqueue_event(&asoc->ulpq, event);
 }
 
 /* Create and initialize an SCTP_REMOTE_ERROR notification.
  *
  * Note: This assumes that the chunk->skb->data already points to the
  * operation error payload.
  *
  * Socket Extensions for SCTP - draft-01
  * 5.3.1.3 SCTP_REMOTE_ERROR
  *
  * A remote peer may send an Operational Error message to its peer.
  * This message indicates a variety of error conditions on an
  * association. The entire error TLV as it appears on the wire is
  * included in a SCTP_REMOTE_ERROR event.  Please refer to the SCTP
  * specification [SCTP] and any extensions for a list of possible
  * error formats.
  */
 struct sctp_ulpevent *
 sctp_ulpevent_make_remote_error(const struct sctp_association *asoc,
                 struct sctp_chunk *chunk, __u16 flags,
                 gfp_t gfp)
 {
     struct sctp_remote_error *sre;
     struct sctp_ulpevent *event;
     struct sctp_errhdr *ch;
     struct sk_buff *skb;
     __be16 cause;
     int elen;
 
     ch = (struct sctp_errhdr *)(chunk->skb->data);
     cause = ch->cause;
     elen = SCTP_PAD4(ntohs(ch->length)) - sizeof(*ch);
 
     /* Pull off the ERROR header.  */
     skb_pull(chunk->skb, sizeof(*ch));
 
     /* Copy the skb to a new skb with room for us to prepend
      * notification with.
      */
     skb = skb_copy_expand(chunk->skb, sizeof(*sre), 0, gfp);
 
     /* Pull off the rest of the cause TLV from the chunk.  */
     skb_pull(chunk->skb, elen);
     if (!skb)
         goto fail;
 
     /* Embed the event fields inside the cloned skb.  */
     event = sctp_skb2event(skb);
     sctp_ulpevent_init(event, MSG_NOTIFICATION, skb->truesize);
 
     sre = skb_push(skb, sizeof(*sre));
 
     /* Trim the buffer to the right length.  */
     skb_trim(skb, sizeof(*sre) + elen);
 
     /* RFC6458, Section 6.1.3. SCTP_REMOTE_ERROR */
     memset(sre, 0, sizeof(*sre));
     sre->sre_type = SCTP_REMOTE_ERROR;
     sre->sre_flags = 0;
     sre->sre_length = skb->len;
     sre->sre_error = cause;
     sctp_ulpevent_set_owner(event, asoc);
     sre->sre_assoc_id = sctp_assoc2id(asoc);
 
     return event;
 fail:
     return NULL;
 }
 
 /* Create and initialize a SCTP_SEND_FAILED notification.
  *
  * Socket Extensions for SCTP - draft-01
  * 5.3.1.4 SCTP_SEND_FAILED
  */
 struct sctp_ulpevent *sctp_ulpevent_make_send_failed(
     const struct sctp_association *asoc, struct sctp_chunk *chunk,
     __u16 flags, __u32 error, gfp_t gfp)
 {
     struct sctp_ulpevent *event;
     struct sctp_send_failed *ssf;
     struct sk_buff *skb;
 
     /* Pull off any padding. */
     int len = ntohs(chunk->chunk_hdr->length);
 
     /* Make skb with more room so we can prepend notification.  */
     skb = skb_copy_expand(chunk->skb,
                   sizeof(struct sctp_send_failed), /* headroom */
                   0,                               /* tailroom */
                   gfp);
     if (!skb)
         goto fail;
 
     /* Pull off the common chunk header and DATA header.  */
     skb_pull(skb, sctp_datachk_len(&asoc->stream));
     len -= sctp_datachk_len(&asoc->stream);
 
     /* Embed the event fields inside the cloned skb.  */
     event = sctp_skb2event(skb);
     sctp_ulpevent_init(event, MSG_NOTIFICATION, skb->truesize);
 
     ssf = skb_push(skb, sizeof(struct sctp_send_failed));
 
     /* Socket Extensions for SCTP
      * 5.3.1.4 SCTP_SEND_FAILED
      *
      * ssf_type:
      * It should be SCTP_SEND_FAILED.
      */
     ssf->ssf_type = SCTP_SEND_FAILED;
 
     /* Socket Extensions for SCTP
      * 5.3.1.4 SCTP_SEND_FAILED
      *
      * ssf_flags: 16 bits (unsigned integer)
      * The flag value will take one of the following values
      *
      * SCTP_DATA_UNSENT - Indicates that the data was never put on
      *                    the wire.
      *
      * SCTP_DATA_SENT   - Indicates that the data was put on the wire.
      *                    Note that this does not necessarily mean that the
      *                    data was (or was not) successfully delivered.
      */
     ssf->ssf_flags = flags;
 
     /* Socket Extensions for SCTP
      * 5.3.1.4 SCTP_SEND_FAILED
      *
      * ssf_length: sizeof (__u32)
      * This field is the total length of the notification data, including
      * the notification header.
      */
     ssf->ssf_length = sizeof(struct sctp_send_failed) + len;
     skb_trim(skb, ssf->ssf_length);
 
     /* Socket Extensions for SCTP
      * 5.3.1.4 SCTP_SEND_FAILED
      *
      * ssf_error: 16 bits (unsigned integer)
      * This value represents the reason why the send failed, and if set,
      * will be a SCTP protocol error code as defined in [SCTP] section
      * 3.3.10.
      */
     ssf->ssf_error = error;
 
     /* Socket Extensions for SCTP
      * 5.3.1.4 SCTP_SEND_FAILED
      *
      * ssf_info: sizeof (struct sctp_sndrcvinfo)
      * The original send information associated with the undelivered
      * message.
      */
     memcpy(&ssf->ssf_info, &chunk->sinfo, sizeof(struct sctp_sndrcvinfo));
 
     /* Per TSVWG discussion with Randy. Allow the application to
      * reassemble a fragmented message.
      */
     ssf->ssf_info.sinfo_flags = chunk->chunk_hdr->flags;
 
     /* Socket Extensions for SCTP
      * 5.3.1.4 SCTP_SEND_FAILED
      *
      * ssf_assoc_id: sizeof (sctp_assoc_t)
      * The association id field, sf_assoc_id, holds the identifier for the
      * association.  All notifications for a given association have the
      * same association identifier.  For TCP style socket, this field is
      * ignored.
      */
     sctp_ulpevent_set_owner(event, asoc);
     ssf->ssf_assoc_id = sctp_assoc2id(asoc);
     return event;
 
 fail:
     return NULL;
 }
 
 struct sctp_ulpevent *sctp_ulpevent_make_send_failed_event(
     const struct sctp_association *asoc, struct sctp_chunk *chunk,
     __u16 flags, __u32 error, gfp_t gfp)
 {
     struct sctp_send_failed_event *ssf;
     struct sctp_ulpevent *event;
     struct sk_buff *skb;
     int len;
 
     skb = skb_copy_expand(chunk->skb, sizeof(*ssf), 0, gfp);
     if (!skb)
         return NULL;
 
     len = ntohs(chunk->chunk_hdr->length);
     len -= sctp_datachk_len(&asoc->stream);
 
     skb_pull(skb, sctp_datachk_len(&asoc->stream));
     event = sctp_skb2event(skb);
     sctp_ulpevent_init(event, MSG_NOTIFICATION, skb->truesize);
 
     ssf = skb_push(skb, sizeof(*ssf));
     ssf->ssf_type = SCTP_SEND_FAILED_EVENT;
     ssf->ssf_flags = flags;
     ssf->ssf_length = sizeof(*ssf) + len;
     skb_trim(skb, ssf->ssf_length);
     ssf->ssf_error = error;
 
     ssf->ssfe_info.snd_sid = chunk->sinfo.sinfo_stream;
     ssf->ssfe_info.snd_ppid = chunk->sinfo.sinfo_ppid;
     ssf->ssfe_info.snd_context = chunk->sinfo.sinfo_context;
     ssf->ssfe_info.snd_assoc_id = chunk->sinfo.sinfo_assoc_id;
     ssf->ssfe_info.snd_flags = chunk->chunk_hdr->flags;
 
     sctp_ulpevent_set_owner(event, asoc);
     ssf->ssf_assoc_id = sctp_assoc2id(asoc);
 
     return event;
 }
 
 /* Create and initialize a SCTP_SHUTDOWN_EVENT notification.
  *
  * Socket Extensions for SCTP - draft-01
  * 5.3.1.5 SCTP_SHUTDOWN_EVENT
  */
 struct sctp_ulpevent *sctp_ulpevent_make_shutdown_event(
     const struct sctp_association *asoc,
     __u16 flags, gfp_t gfp)
 {
     struct sctp_ulpevent *event;
     struct sctp_shutdown_event *sse;
     struct sk_buff *skb;
 
     event = sctp_ulpevent_new(sizeof(struct sctp_shutdown_event),
                   MSG_NOTIFICATION, gfp);
     if (!event)
         goto fail;
 
     skb = sctp_event2skb(event);
     sse = skb_put(skb, sizeof(struct sctp_shutdown_event));
 
     /* Socket Extensions for SCTP
      * 5.3.1.5 SCTP_SHUTDOWN_EVENT
      *
      * sse_type
      * It should be SCTP_SHUTDOWN_EVENT
      */
     sse->sse_type = SCTP_SHUTDOWN_EVENT;
 
     /* Socket Extensions for SCTP
      * 5.3.1.5 SCTP_SHUTDOWN_EVENT
      *
      * sse_flags: 16 bits (unsigned integer)
      * Currently unused.
      */
     sse->sse_flags = 0;
 
     /* Socket Extensions for SCTP
      * 5.3.1.5 SCTP_SHUTDOWN_EVENT
      *
      * sse_length: sizeof (__u32)
      * This field is the total length of the notification data, including
      * the notification header.
      */
     sse->sse_length = sizeof(struct sctp_shutdown_event);
 
     /* Socket Extensions for SCTP
      * 5.3.1.5 SCTP_SHUTDOWN_EVENT
      *
      * sse_assoc_id: sizeof (sctp_assoc_t)
      * The association id field, holds the identifier for the association.
      * All notifications for a given association have the same association
      * identifier.  For TCP style socket, this field is ignored.
      */
     sctp_ulpevent_set_owner(event, asoc);
     sse->sse_assoc_id = sctp_assoc2id(asoc);
 
     return event;
 
 fail:
     return NULL;
 }
 
 /* Create and initialize a SCTP_ADAPTATION_INDICATION notification.
  *
  * Socket Extensions for SCTP
  * 5.3.1.6 SCTP_ADAPTATION_INDICATION
  */
 struct sctp_ulpevent *sctp_ulpevent_make_adaptation_indication(
     const struct sctp_association *asoc, gfp_t gfp)
 {
     struct sctp_ulpevent *event;
     struct sctp_adaptation_event *sai;
     struct sk_buff *skb;
 
     event = sctp_ulpevent_new(sizeof(struct sctp_adaptation_event),
                   MSG_NOTIFICATION, gfp);
     if (!event)
         goto fail;
 
     skb = sctp_event2skb(event);
     sai = skb_put(skb, sizeof(struct sctp_adaptation_event));
 
     sai->sai_type = SCTP_ADAPTATION_INDICATION;
     sai->sai_flags = 0;
     sai->sai_length = sizeof(struct sctp_adaptation_event);
     sai->sai_adaptation_ind = asoc->peer.adaptation_ind;
     sctp_ulpevent_set_owner(event, asoc);
     sai->sai_assoc_id = sctp_assoc2id(asoc);
 
     return event;
 
 fail:
     return NULL;
 }
 
 /* A message has been received.  Package this message as a notification
  * to pass it to the upper layers.  Go ahead and calculate the sndrcvinfo
  * even if filtered out later.
  *
  * Socket Extensions for SCTP
  * 5.2.2 SCTP Header Information Structure (SCTP_SNDRCV)
  */
 struct sctp_ulpevent *sctp_ulpevent_make_rcvmsg(struct sctp_association *asoc,
                         struct sctp_chunk *chunk,
                         gfp_t gfp)
 {
     struct sctp_ulpevent *event = NULL;
     struct sk_buff *skb = chunk->skb;
     struct sock *sk = asoc->base.sk;
     size_t padding, datalen;
     int rx_count;
 
     /*
      * check to see if we need to make space for this
      * new skb, expand the rcvbuffer if needed, or drop
      * the frame
      */
     if (asoc->ep->rcvbuf_policy)
         rx_count = atomic_read(&asoc->rmem_alloc);
     else
         rx_count = atomic_read(&sk->sk_rmem_alloc);
 
     datalen = ntohs(chunk->chunk_hdr->length);
 
     if (rx_count >= sk->sk_rcvbuf || !sk_rmem_schedule(sk, skb, datalen))
         goto fail;
 
     /* Clone the original skb, sharing the data.  */
     skb = skb_clone(chunk->skb, gfp);
     if (!skb)
         goto fail;
 
     /* Now that all memory allocations for this chunk succeeded, we
      * can mark it as received so the tsn_map is updated correctly.
      */
     if (sctp_tsnmap_mark(&asoc->peer.tsn_map,
                  ntohl(chunk->subh.data_hdr->tsn),
                  chunk->transport))
         goto fail_mark;
 
     /* First calculate the padding, so we don't inadvertently
      * pass up the wrong length to the user.
      *
      * RFC 2960 - Section 3.2  Chunk Field Descriptions
      *
      * The total length of a chunk(including Type, Length and Value fields)
      * MUST be a multiple of 4 bytes.  If the length of the chunk is not a
      * multiple of 4 bytes, the sender MUST pad the chunk with all zero
      * bytes and this padding is not included in the chunk length field.
      * The sender should never pad with more than 3 bytes.  The receiver
      * MUST ignore the padding bytes.
      */
     padding = SCTP_PAD4(datalen) - datalen;
 
     /* Fixup cloned skb with just this chunks data.  */
     skb_trim(skb, chunk->chunk_end - padding - skb->data);
 
     /* Embed the event fields inside the cloned skb.  */
     event = sctp_skb2event(skb);
 
     /* Initialize event with flags 0  and correct length
      * Since this is a clone of the original skb, only account for
      * the data of this chunk as other chunks will be accounted separately.
      */
     sctp_ulpevent_init(event, 0, skb->len + sizeof(struct sk_buff));
 
     /* And hold the chunk as we need it for getting the IP headers
      * later in recvmsg
      */
     sctp_chunk_hold(chunk);
     event->chunk = chunk;
 
     sctp_ulpevent_receive_data(event, asoc);
 
     event->stream = ntohs(chunk->subh.data_hdr->stream);
     if (chunk->chunk_hdr->flags & SCTP_DATA_UNORDERED) {
         event->flags |= SCTP_UNORDERED;
         event->cumtsn = sctp_tsnmap_get_ctsn(&asoc->peer.tsn_map);
     }
     event->tsn = ntohl(chunk->subh.data_hdr->tsn);
     event->msg_flags |= chunk->chunk_hdr->flags;
 
     return event;
 
 fail_mark:
     kfree_skb(skb);
 fail:
     return NULL;
 }
 
 /* Create a partial delivery related event.
  *
  * 5.3.1.7 SCTP_PARTIAL_DELIVERY_EVENT
  *
  *   When a receiver is engaged in a partial delivery of a
  *   message this notification will be used to indicate
  *   various events.
  */
 struct sctp_ulpevent *sctp_ulpevent_make_pdapi(
                     const struct sctp_association *asoc,
                     __u32 indication, __u32 sid, __u32 seq,
                     __u32 flags, gfp_t gfp)
 {
     struct sctp_ulpevent *event;
     struct sctp_pdapi_event *pd;
     struct sk_buff *skb;
 
     event = sctp_ulpevent_new(sizeof(struct sctp_pdapi_event),
                   MSG_NOTIFICATION, gfp);
     if (!event)
         goto fail;
 
     skb = sctp_event2skb(event);
     pd = skb_put(skb, sizeof(struct sctp_pdapi_event));
 
     /* pdapi_type
      *   It should be SCTP_PARTIAL_DELIVERY_EVENT
      *
      * pdapi_flags: 16 bits (unsigned integer)
      *   Currently unused.
      */
     pd->pdapi_type = SCTP_PARTIAL_DELIVERY_EVENT;
     pd->pdapi_flags = flags;
     pd->pdapi_stream = sid;
     pd->pdapi_seq = seq;
 
     /* pdapi_length: 32 bits (unsigned integer)
      *
      * This field is the total length of the notification data, including
      * the notification header.  It will generally be sizeof (struct
      * sctp_pdapi_event).
      */
     pd->pdapi_length = sizeof(struct sctp_pdapi_event);
 
     /*  pdapi_indication: 32 bits (unsigned integer)
      *
      * This field holds the indication being sent to the application.
      */
     pd->pdapi_indication = indication;
 
     /*  pdapi_assoc_id: sizeof (sctp_assoc_t)
      *
      * The association id field, holds the identifier for the association.
      */
     sctp_ulpevent_set_owner(event, asoc);
     pd->pdapi_assoc_id = sctp_assoc2id(asoc);
 
     return event;
 fail:
     return NULL;
 }
 
 struct sctp_ulpevent *sctp_ulpevent_make_authkey(
     const struct sctp_association *asoc, __u16 key_id,
     __u32 indication, gfp_t gfp)
 {
     struct sctp_ulpevent *event;
     struct sctp_authkey_event *ak;
     struct sk_buff *skb;
 
     event = sctp_ulpevent_new(sizeof(struct sctp_authkey_event),
                   MSG_NOTIFICATION, gfp);
     if (!event)
         goto fail;
 
     skb = sctp_event2skb(event);
     ak = skb_put(skb, sizeof(struct sctp_authkey_event));
 
     ak->auth_type = SCTP_AUTHENTICATION_EVENT;
     ak->auth_flags = 0;
     ak->auth_length = sizeof(struct sctp_authkey_event);
 
     ak->auth_keynumber = key_id;
     ak->auth_altkeynumber = 0;
     ak->auth_indication = indication;
 
     /*
      * The association id field, holds the identifier for the association.
      */
     sctp_ulpevent_set_owner(event, asoc);
     ak->auth_assoc_id = sctp_assoc2id(asoc);
 
     return event;
 fail:
     return NULL;
 }
 
 /*
  * Socket Extensions for SCTP
  * 6.3.10. SCTP_SENDER_DRY_EVENT
  */
 struct sctp_ulpevent *sctp_ulpevent_make_sender_dry_event(
     const struct sctp_association *asoc, gfp_t gfp)
 {
     struct sctp_ulpevent *event;
     struct sctp_sender_dry_event *sdry;
     struct sk_buff *skb;
 
     event = sctp_ulpevent_new(sizeof(struct sctp_sender_dry_event),
                   MSG_NOTIFICATION, gfp);
     if (!event)
         return NULL;
 
     skb = sctp_event2skb(event);
     sdry = skb_put(skb, sizeof(struct sctp_sender_dry_event));
 
     sdry->sender_dry_type = SCTP_SENDER_DRY_EVENT;
     sdry->sender_dry_flags = 0;
     sdry->sender_dry_length = sizeof(struct sctp_sender_dry_event);
     sctp_ulpevent_set_owner(event, asoc);
     sdry->sender_dry_assoc_id = sctp_assoc2id(asoc);
 
     return event;
 }
 
 struct sctp_ulpevent *sctp_ulpevent_make_stream_reset_event(
     const struct sctp_association *asoc, __u16 flags, __u16 stream_num,
     __be16 *stream_list, gfp_t gfp)
 {
     struct sctp_stream_reset_event *sreset;
     struct sctp_ulpevent *event;
     struct sk_buff *skb;
     int length, i;
 
     length = sizeof(struct sctp_stream_reset_event) + 2 * stream_num;
     event = sctp_ulpevent_new(length, MSG_NOTIFICATION, gfp);
     if (!event)
         return NULL;
 
     skb = sctp_event2skb(event);
     sreset = skb_put(skb, length);
 
     sreset->strreset_type = SCTP_STREAM_RESET_EVENT;
     sreset->strreset_flags = flags;
     sreset->strreset_length = length;
     sctp_ulpevent_set_owner(event, asoc);
     sreset->strreset_assoc_id = sctp_assoc2id(asoc);
 
     for (i = 0; i < stream_num; i++)
         sreset->strreset_stream_list[i] = ntohs(stream_list[i]);
 
     return event;
 }
 
 struct sctp_ulpevent *sctp_ulpevent_make_assoc_reset_event(
     const struct sctp_association *asoc, __u16 flags, __u32 local_tsn,
     __u32 remote_tsn, gfp_t gfp)
 {
     struct sctp_assoc_reset_event *areset;
     struct sctp_ulpevent *event;
     struct sk_buff *skb;
 
     event = sctp_ulpevent_new(sizeof(struct sctp_assoc_reset_event),
                   MSG_NOTIFICATION, gfp);
     if (!event)
         return NULL;
 
     skb = sctp_event2skb(event);
     areset = skb_put(skb, sizeof(struct sctp_assoc_reset_event));
 
     areset->assocreset_type = SCTP_ASSOC_RESET_EVENT;
     areset->assocreset_flags = flags;
     areset->assocreset_length = sizeof(struct sctp_assoc_reset_event);
     sctp_ulpevent_set_owner(event, asoc);
     areset->assocreset_assoc_id = sctp_assoc2id(asoc);
     areset->assocreset_local_tsn = local_tsn;
     areset->assocreset_remote_tsn = remote_tsn;
 
     return event;
 }
 
 struct sctp_ulpevent *sctp_ulpevent_make_stream_change_event(
     const struct sctp_association *asoc, __u16 flags,
     __u32 strchange_instrms, __u32 strchange_outstrms, gfp_t gfp)
 {
     struct sctp_stream_change_event *schange;
     struct sctp_ulpevent *event;
     struct sk_buff *skb;
 
     event = sctp_ulpevent_new(sizeof(struct sctp_stream_change_event),
                   MSG_NOTIFICATION, gfp);
     if (!event)
         return NULL;
 
     skb = sctp_event2skb(event);
     schange = skb_put(skb, sizeof(struct sctp_stream_change_event));
 
     schange->strchange_type = SCTP_STREAM_CHANGE_EVENT;
     schange->strchange_flags = flags;
     schange->strchange_length = sizeof(struct sctp_stream_change_event);
     sctp_ulpevent_set_owner(event, asoc);
     schange->strchange_assoc_id = sctp_assoc2id(asoc);
     schange->strchange_instrms = strchange_instrms;
     schange->strchange_outstrms = strchange_outstrms;
 
     return event;
 }
 
 /* Return the notification type, assuming this is a notification
  * event.
  */
 __u16 sctp_ulpevent_get_notification_type(const struct sctp_ulpevent *event)
 {
     union sctp_notification *notification;
     struct sk_buff *skb;
 
     skb = sctp_event2skb(event);
     notification = (union sctp_notification *) skb->data;
     return notification->sn_header.sn_type;
 }
 
 /* RFC6458, Section 5.3.2. SCTP Header Information Structure
  * (SCTP_SNDRCV, DEPRECATED)
  */
 void sctp_ulpevent_read_sndrcvinfo(const struct sctp_ulpevent *event,
                    struct msghdr *msghdr)
 {
     struct sctp_sndrcvinfo sinfo;
 
     if (sctp_ulpevent_is_notification(event))
         return;
 
     memset(&sinfo, 0, sizeof(sinfo));
     sinfo.sinfo_stream = event->stream;
     sinfo.sinfo_ssn = event->ssn;
     sinfo.sinfo_ppid = event->ppid;
     sinfo.sinfo_flags = event->flags;
     sinfo.sinfo_tsn = event->tsn;
     sinfo.sinfo_cumtsn = event->cumtsn;
     sinfo.sinfo_assoc_id = sctp_assoc2id(event->asoc);
     /* Context value that is set via SCTP_CONTEXT socket option. */
     sinfo.sinfo_context = event->asoc->default_rcv_context;
     /* These fields are not used while receiving. */
     sinfo.sinfo_timetolive = 0;
 
     put_cmsg(msghdr, IPPROTO_SCTP, SCTP_SNDRCV,
          sizeof(sinfo), &sinfo);
 }
 
 /* RFC6458, Section 5.3.5 SCTP Receive Information Structure
  * (SCTP_SNDRCV)
  */
 void sctp_ulpevent_read_rcvinfo(const struct sctp_ulpevent *event,
                 struct msghdr *msghdr)
 {
     struct sctp_rcvinfo rinfo;
 
     if (sctp_ulpevent_is_notification(event))
         return;
 
     memset(&rinfo, 0, sizeof(struct sctp_rcvinfo));
     rinfo.rcv_sid = event->stream;
     rinfo.rcv_ssn = event->ssn;
     rinfo.rcv_ppid = event->ppid;
     rinfo.rcv_flags = event->flags;
     rinfo.rcv_tsn = event->tsn;
     rinfo.rcv_cumtsn = event->cumtsn;
     rinfo.rcv_assoc_id = sctp_assoc2id(event->asoc);
     rinfo.rcv_context = event->asoc->default_rcv_context;
 
     put_cmsg(msghdr, IPPROTO_SCTP, SCTP_RCVINFO,
          sizeof(rinfo), &rinfo);
 }
 
 /* RFC6458, Section 5.3.6. SCTP Next Receive Information Structure
  * (SCTP_NXTINFO)
  */
 static void __sctp_ulpevent_read_nxtinfo(const struct sctp_ulpevent *event,
                      struct msghdr *msghdr,
                      const struct sk_buff *skb)
 {
     struct sctp_nxtinfo nxtinfo;
 
     memset(&nxtinfo, 0, sizeof(nxtinfo));
     nxtinfo.nxt_sid = event->stream;
     nxtinfo.nxt_ppid = event->ppid;
     nxtinfo.nxt_flags = event->flags;
     if (sctp_ulpevent_is_notification(event))
         nxtinfo.nxt_flags |= SCTP_NOTIFICATION;
     nxtinfo.nxt_length = skb->len;
     nxtinfo.nxt_assoc_id = sctp_assoc2id(event->asoc);
 
     put_cmsg(msghdr, IPPROTO_SCTP, SCTP_NXTINFO,
          sizeof(nxtinfo), &nxtinfo);
 }
 
 void sctp_ulpevent_read_nxtinfo(const struct sctp_ulpevent *event,
                 struct msghdr *msghdr,
                 struct sock *sk)
 {
     struct sk_buff *skb;
     int err;
 
     skb = sctp_skb_recv_datagram(sk, MSG_PEEK | MSG_DONTWAIT, &err);
     if (skb != NULL) {
         __sctp_ulpevent_read_nxtinfo(sctp_skb2event(skb),
                          msghdr, skb);
         /* Just release refcount here. */
         kfree_skb(skb);
     }
 }
 
 /* Do accounting for bytes received and hold a reference to the association
  * for each skb.
  */
 static void sctp_ulpevent_receive_data(struct sctp_ulpevent *event,
                        struct sctp_association *asoc)
 {
     struct sk_buff *skb, *frag;
 
     skb = sctp_event2skb(event);
     /* Set the owner and charge rwnd for bytes received.  */
     sctp_ulpevent_set_owner(event, asoc);
     sctp_assoc_rwnd_decrease(asoc, skb_headlen(skb));
 
     if (!skb->data_len)
         return;
 
     /* Note:  Not clearing the entire event struct as this is just a
      * fragment of the real event.  However, we still need to do rwnd
      * accounting.
      * In general, the skb passed from IP can have only 1 level of
      * fragments. But we allow multiple levels of fragments.
      */
     skb_walk_frags(skb, frag)
         sctp_ulpevent_receive_data(sctp_skb2event(frag), asoc);
 }
 
 /* Do accounting for bytes just read by user and release the references to
  * the association.
  */
 static void sctp_ulpevent_release_data(struct sctp_ulpevent *event)
 {
     struct sk_buff *skb, *frag;
     unsigned int    len;
 
     /* Current stack structures assume that the rcv buffer is
      * per socket.   For UDP style sockets this is not true as
      * multiple associations may be on a single UDP-style socket.
      * Use the local private area of the skb to track the owning
      * association.
      */
 
     skb = sctp_event2skb(event);
     len = skb->len;
 
     if (!skb->data_len)
         goto done;
 
     /* Don't forget the fragments. */
     skb_walk_frags(skb, frag) {
         /* NOTE:  skb_shinfos are recursive. Although IP returns
          * skb's with only 1 level of fragments, SCTP reassembly can
          * increase the levels.
          */
         sctp_ulpevent_release_frag_data(sctp_skb2event(frag));
     }
 
 done:
     sctp_assoc_rwnd_increase(event->asoc, len);
     sctp_chunk_put(event->chunk);
     sctp_ulpevent_release_owner(event);
 }
 
 static void sctp_ulpevent_release_frag_data(struct sctp_ulpevent *event)
 {
     struct sk_buff *skb, *frag;
 
     skb = sctp_event2skb(event);
 
     if (!skb->data_len)
         goto done;
 
     /* Don't forget the fragments. */
     skb_walk_frags(skb, frag) {
         /* NOTE:  skb_shinfos are recursive. Although IP returns
          * skb's with only 1 level of fragments, SCTP reassembly can
          * increase the levels.
          */
         sctp_ulpevent_release_frag_data(sctp_skb2event(frag));
     }
 
 done:
     sctp_chunk_put(event->chunk);
     sctp_ulpevent_release_owner(event);
 }
 
 /* Free a ulpevent that has an owner.  It includes releasing the reference
  * to the owner, updating the rwnd in case of a DATA event and freeing the
  * skb.
  */
 void sctp_ulpevent_free(struct sctp_ulpevent *event)
 {
     if (sctp_ulpevent_is_notification(event))
         sctp_ulpevent_release_owner(event);
     else
         sctp_ulpevent_release_data(event);
 
     kfree_skb(sctp_event2skb(event));
 }
 
 /* Purge the skb lists holding ulpevents. */
 unsigned int sctp_queue_purge_ulpevents(struct sk_buff_head *list)
 {
     struct sk_buff *skb;
     unsigned int data_unread = 0;
 
     while ((skb = skb_dequeue(list)) != NULL) {
         struct sctp_ulpevent *event = sctp_skb2event(skb);
 
         if (!sctp_ulpevent_is_notification(event))
             data_unread += skb->len;
 
         sctp_ulpevent_free(event);
     }
 
     return data_unread;
 }

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