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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
 /*
  *  IP multicast routing support for mrouted 3.6/3.8
  *
  *      (c) 1995 Alan Cox, <alan@lxorguk.ukuu.org.uk>
  *    Linux Consultancy and Custom Driver Development
  *
  *  Fixes:
  *  Michael Chastain    :   Incorrect size of copying.
  *  Alan Cox        :   Added the cache manager code
  *  Alan Cox        :   Fixed the clone/copy bug and device race.
  *  Mike McLagan        :   Routing by source
  *  Malcolm Beattie     :   Buffer handling fixes.
  *  Alexey Kuznetsov    :   Double buffer free and other fixes.
  *  SVR Anand       :   Fixed several multicast bugs and problems.
  *  Alexey Kuznetsov    :   Status, optimisations and more.
  *  Brad Parker     :   Better behaviour on mrouted upcall
  *                  overflow.
  *      Carlos Picoto           :       PIMv1 Support
  *  Pavlin Ivanov Radoslavov:   PIMv2 Registers must checksum only PIM header
  *                  Relax this requirement to work with older peers.
  */
 
 #include <linux/uaccess.h>
 #include <linux/types.h>
 #include <linux/cache.h>
 #include <linux/capability.h>
 #include <linux/errno.h>
 #include <linux/mm.h>
 #include <linux/kernel.h>
 #include <linux/fcntl.h>
 #include <linux/stat.h>
 #include <linux/socket.h>
 #include <linux/in.h>
 #include <linux/inet.h>
 #include <linux/netdevice.h>
 #include <linux/inetdevice.h>
 #include <linux/igmp.h>
 #include <linux/proc_fs.h>
 #include <linux/seq_file.h>
 #include <linux/mroute.h>
 #include <linux/init.h>
 #include <linux/if_ether.h>
 #include <linux/slab.h>
 #include <net/net_namespace.h>
 #include <net/ip.h>
 #include <net/protocol.h>
 #include <linux/skbuff.h>
 #include <net/route.h>
 #include <net/icmp.h>
 #include <net/udp.h>
 #include <net/raw.h>
 #include <linux/notifier.h>
 #include <linux/if_arp.h>
 #include <linux/netfilter_ipv4.h>
 #include <linux/compat.h>
 #include <linux/export.h>
 #include <linux/rhashtable.h>
 #include <net/ip_tunnels.h>
 #include <net/checksum.h>
 #include <net/netlink.h>
 #include <net/fib_rules.h>
 #include <linux/netconf.h>
 #include <net/rtnh.h>
 
 #include <linux/nospec.h>
 
 struct ipmr_rule {
     struct fib_rule     common;
 };
 
 struct ipmr_result {
     struct mr_table     *mrt;
 };
 
 /* Big lock, protecting vif table, mrt cache and mroute socket state.
  * Note that the changes are semaphored via rtnl_lock.
  */
 
 static DEFINE_SPINLOCK(mrt_lock);
 
 static struct net_device *vif_dev_read(const struct vif_device *vif)
 {
     return rcu_dereference(vif->dev);
 }
 
 /* Multicast router control variables */
 
 /* Special spinlock for queue of unresolved entries */
 static DEFINE_SPINLOCK(mfc_unres_lock);
 
 /* We return to original Alan's scheme. Hash table of resolved
  * entries is changed only in process context and protected
  * with weak lock mrt_lock. Queue of unresolved entries is protected
  * with strong spinlock mfc_unres_lock.
  *
  * In this case data path is free of exclusive locks at all.
  */
 
 static struct kmem_cache *mrt_cachep __ro_after_init;
 
 static struct mr_table *ipmr_new_table(struct net *net, u32 id);
 static void ipmr_free_table(struct mr_table *mrt);
 
 static void ip_mr_forward(struct net *net, struct mr_table *mrt,
               struct net_device *dev, struct sk_buff *skb,
               struct mfc_cache *cache, int local);
 static int ipmr_cache_report(const struct mr_table *mrt,
                  struct sk_buff *pkt, vifi_t vifi, int assert);
 static void mroute_netlink_event(struct mr_table *mrt, struct mfc_cache *mfc,
                  int cmd);
 static void igmpmsg_netlink_event(const struct mr_table *mrt, struct sk_buff *pkt);
 static void mroute_clean_tables(struct mr_table *mrt, int flags);
 static void ipmr_expire_process(struct timer_list *t);
 
 #ifdef CONFIG_IP_MROUTE_MULTIPLE_TABLES
 #define ipmr_for_each_table(mrt, net)                   \
     list_for_each_entry_rcu(mrt, &net->ipv4.mr_tables, list,    \
                 lockdep_rtnl_is_held() ||       \
                 list_empty(&net->ipv4.mr_tables))
 
 static struct mr_table *ipmr_mr_table_iter(struct net *net,
                        struct mr_table *mrt)
 {
     struct mr_table *ret;
 
     if (!mrt)
         ret = list_entry_rcu(net->ipv4.mr_tables.next,
                      struct mr_table, list);
     else
         ret = list_entry_rcu(mrt->list.next,
                      struct mr_table, list);
 
     if (&ret->list == &net->ipv4.mr_tables)
         return NULL;
     return ret;
 }
 
 static struct mr_table *ipmr_get_table(struct net *net, u32 id)
 {
     struct mr_table *mrt;
 
     ipmr_for_each_table(mrt, net) {
         if (mrt->id == id)
             return mrt;
     }
     return NULL;
 }
 
 static int ipmr_fib_lookup(struct net *net, struct flowi4 *flp4,
                struct mr_table **mrt)
 {
     int err;
     struct ipmr_result res;
     struct fib_lookup_arg arg = {
         .result = &res,
         .flags = FIB_LOOKUP_NOREF,
     };
 
     /* update flow if oif or iif point to device enslaved to l3mdev */
     l3mdev_update_flow(net, flowi4_to_flowi(flp4));
 
     err = fib_rules_lookup(net->ipv4.mr_rules_ops,
                    flowi4_to_flowi(flp4), 0, &arg);
     if (err < 0)
         return err;
     *mrt = res.mrt;
     return 0;
 }
 
 static int ipmr_rule_action(struct fib_rule *rule, struct flowi *flp,
                 int flags, struct fib_lookup_arg *arg)
 {
     struct ipmr_result *res = arg->result;
     struct mr_table *mrt;
 
     switch (rule->action) {
     case FR_ACT_TO_TBL:
         break;
     case FR_ACT_UNREACHABLE:
         return -ENETUNREACH;
     case FR_ACT_PROHIBIT:
         return -EACCES;
     case FR_ACT_BLACKHOLE:
     default:
         return -EINVAL;
     }
 
     arg->table = fib_rule_get_table(rule, arg);
 
     mrt = ipmr_get_table(rule->fr_net, arg->table);
     if (!mrt)
         return -EAGAIN;
     res->mrt = mrt;
     return 0;
 }
 
 static int ipmr_rule_match(struct fib_rule *rule, struct flowi *fl, int flags)
 {
     return 1;
 }
 
 static int ipmr_rule_configure(struct fib_rule *rule, struct sk_buff *skb,
                    struct fib_rule_hdr *frh, struct nlattr **tb,
                    struct netlink_ext_ack *extack)
 {
     return 0;
 }
 
 static int ipmr_rule_compare(struct fib_rule *rule, struct fib_rule_hdr *frh,
                  struct nlattr **tb)
 {
     return 1;
 }
 
 static int ipmr_rule_fill(struct fib_rule *rule, struct sk_buff *skb,
               struct fib_rule_hdr *frh)
 {
     frh->dst_len = 0;
     frh->src_len = 0;
     frh->tos     = 0;
     return 0;
 }
 
 static const struct fib_rules_ops __net_initconst ipmr_rules_ops_template = {
     .family     = RTNL_FAMILY_IPMR,
     .rule_size  = sizeof(struct ipmr_rule),
     .addr_size  = sizeof(u32),
     .action     = ipmr_rule_action,
     .match      = ipmr_rule_match,
     .configure  = ipmr_rule_configure,
     .compare    = ipmr_rule_compare,
     .fill       = ipmr_rule_fill,
     .nlgroup    = RTNLGRP_IPV4_RULE,
     .owner      = THIS_MODULE,
 };
 
 static int __net_init ipmr_rules_init(struct net *net)
 {
     struct fib_rules_ops *ops;
     struct mr_table *mrt;
     int err;
 
     ops = fib_rules_register(&ipmr_rules_ops_template, net);
     if (IS_ERR(ops))
         return PTR_ERR(ops);
 
     INIT_LIST_HEAD(&net->ipv4.mr_tables);
 
     mrt = ipmr_new_table(net, RT_TABLE_DEFAULT);
     if (IS_ERR(mrt)) {
         err = PTR_ERR(mrt);
         goto err1;
     }
 
     err = fib_default_rule_add(ops, 0x7fff, RT_TABLE_DEFAULT, 0);
     if (err < 0)
         goto err2;
 
     net->ipv4.mr_rules_ops = ops;
     return 0;
 
 err2:
     rtnl_lock();
     ipmr_free_table(mrt);
     rtnl_unlock();
 err1:
     fib_rules_unregister(ops);
     return err;
 }
 
 static void __net_exit ipmr_rules_exit(struct net *net)
 {
     struct mr_table *mrt, *next;
 
     ASSERT_RTNL();
     list_for_each_entry_safe(mrt, next, &net->ipv4.mr_tables, list) {
         list_del(&mrt->list);
         ipmr_free_table(mrt);
     }
     fib_rules_unregister(net->ipv4.mr_rules_ops);
 }
 
 static int ipmr_rules_dump(struct net *net, struct notifier_block *nb,
                struct netlink_ext_ack *extack)
 {
     return fib_rules_dump(net, nb, RTNL_FAMILY_IPMR, extack);
 }
 
 static unsigned int ipmr_rules_seq_read(struct net *net)
 {
     return fib_rules_seq_read(net, RTNL_FAMILY_IPMR);
 }
 
 bool ipmr_rule_default(const struct fib_rule *rule)
 {
     return fib_rule_matchall(rule) && rule->table == RT_TABLE_DEFAULT;
 }
 EXPORT_SYMBOL(ipmr_rule_default);
 #else
 #define ipmr_for_each_table(mrt, net) \
     for (mrt = net->ipv4.mrt; mrt; mrt = NULL)
 
 static struct mr_table *ipmr_mr_table_iter(struct net *net,
                        struct mr_table *mrt)
 {
     if (!mrt)
         return net->ipv4.mrt;
     return NULL;
 }
 
 static struct mr_table *ipmr_get_table(struct net *net, u32 id)
 {
     return net->ipv4.mrt;
 }
 
 static int ipmr_fib_lookup(struct net *net, struct flowi4 *flp4,
                struct mr_table **mrt)
 {
     *mrt = net->ipv4.mrt;
     return 0;
 }
 
 static int __net_init ipmr_rules_init(struct net *net)
 {
     struct mr_table *mrt;
 
     mrt = ipmr_new_table(net, RT_TABLE_DEFAULT);
     if (IS_ERR(mrt))
         return PTR_ERR(mrt);
     net->ipv4.mrt = mrt;
     return 0;
 }
 
 static void __net_exit ipmr_rules_exit(struct net *net)
 {
     ASSERT_RTNL();
     ipmr_free_table(net->ipv4.mrt);
     net->ipv4.mrt = NULL;
 }
 
 static int ipmr_rules_dump(struct net *net, struct notifier_block *nb,
                struct netlink_ext_ack *extack)
 {
     return 0;
 }
 
 static unsigned int ipmr_rules_seq_read(struct net *net)
 {
     return 0;
 }
 
 bool ipmr_rule_default(const struct fib_rule *rule)
 {
     return true;
 }
 EXPORT_SYMBOL(ipmr_rule_default);
 #endif
 
 static inline int ipmr_hash_cmp(struct rhashtable_compare_arg *arg,
                 const void *ptr)
 {
     const struct mfc_cache_cmp_arg *cmparg = arg->key;
     const struct mfc_cache *c = ptr;
 
     return cmparg->mfc_mcastgrp != c->mfc_mcastgrp ||
            cmparg->mfc_origin != c->mfc_origin;
 }
 
 static const struct rhashtable_params ipmr_rht_params = {
     .head_offset = offsetof(struct mr_mfc, mnode),
     .key_offset = offsetof(struct mfc_cache, cmparg),
     .key_len = sizeof(struct mfc_cache_cmp_arg),
     .nelem_hint = 3,
     .obj_cmpfn = ipmr_hash_cmp,
     .automatic_shrinking = true,
 };
 
 static void ipmr_new_table_set(struct mr_table *mrt,
                    struct net *net)
 {
 #ifdef CONFIG_IP_MROUTE_MULTIPLE_TABLES
     list_add_tail_rcu(&mrt->list, &net->ipv4.mr_tables);
 #endif
 }
 
 static struct mfc_cache_cmp_arg ipmr_mr_table_ops_cmparg_any = {
     .mfc_mcastgrp = htonl(INADDR_ANY),
     .mfc_origin = htonl(INADDR_ANY),
 };
 
 static struct mr_table_ops ipmr_mr_table_ops = {
     .rht_params = &ipmr_rht_params,
     .cmparg_any = &ipmr_mr_table_ops_cmparg_any,
 };
 
 static struct mr_table *ipmr_new_table(struct net *net, u32 id)
 {
     struct mr_table *mrt;
 
     /* "pimreg%u" should not exceed 16 bytes (IFNAMSIZ) */
     if (id != RT_TABLE_DEFAULT && id >= 1000000000)
         return ERR_PTR(-EINVAL);
 
     mrt = ipmr_get_table(net, id);
     if (mrt)
         return mrt;
 
     return mr_table_alloc(net, id, &ipmr_mr_table_ops,
                   ipmr_expire_process, ipmr_new_table_set);
 }
 
 static void ipmr_free_table(struct mr_table *mrt)
 {
     del_timer_sync(&mrt->ipmr_expire_timer);
     mroute_clean_tables(mrt, MRT_FLUSH_VIFS | MRT_FLUSH_VIFS_STATIC |
                  MRT_FLUSH_MFC | MRT_FLUSH_MFC_STATIC);
     rhltable_destroy(&mrt->mfc_hash);
     kfree(mrt);
 }
 
 /* Service routines creating virtual interfaces: DVMRP tunnels and PIMREG */
 
 /* Initialize ipmr pimreg/tunnel in_device */
 static bool ipmr_init_vif_indev(const struct net_device *dev)
 {
     struct in_device *in_dev;
 
     ASSERT_RTNL();
 
     in_dev = __in_dev_get_rtnl(dev);
     if (!in_dev)
         return false;
     ipv4_devconf_setall(in_dev);
     neigh_parms_data_state_setall(in_dev->arp_parms);
     IPV4_DEVCONF(in_dev->cnf, RP_FILTER) = 0;
 
     return true;
 }
 
 static struct net_device *ipmr_new_tunnel(struct net *net, struct vifctl *v)
 {
     struct net_device *tunnel_dev, *new_dev;
     struct ip_tunnel_parm p = { };
     int err;
 
     tunnel_dev = __dev_get_by_name(net, "tunl0");
     if (!tunnel_dev)
         goto out;
 
     p.iph.daddr = v->vifc_rmt_addr.s_addr;
     p.iph.saddr = v->vifc_lcl_addr.s_addr;
     p.iph.version = 4;
     p.iph.ihl = 5;
     p.iph.protocol = IPPROTO_IPIP;
     sprintf(p.name, "dvmrp%d", v->vifc_vifi);
 
     if (!tunnel_dev->netdev_ops->ndo_tunnel_ctl)
         goto out;
     err = tunnel_dev->netdev_ops->ndo_tunnel_ctl(tunnel_dev, &p,
             SIOCADDTUNNEL);
     if (err)
         goto out;
 
     new_dev = __dev_get_by_name(net, p.name);
     if (!new_dev)
         goto out;
 
     new_dev->flags |= IFF_MULTICAST;
     if (!ipmr_init_vif_indev(new_dev))
         goto out_unregister;
     if (dev_open(new_dev, NULL))
         goto out_unregister;
     dev_hold(new_dev);
     err = dev_set_allmulti(new_dev, 1);
     if (err) {
         dev_close(new_dev);
         tunnel_dev->netdev_ops->ndo_tunnel_ctl(tunnel_dev, &p,
                 SIOCDELTUNNEL);
         dev_put(new_dev);
         new_dev = ERR_PTR(err);
     }
     return new_dev;
 
 out_unregister:
     unregister_netdevice(new_dev);
 out:
     return ERR_PTR(-ENOBUFS);
 }
 
 #if defined(CONFIG_IP_PIMSM_V1) || defined(CONFIG_IP_PIMSM_V2)
 static netdev_tx_t reg_vif_xmit(struct sk_buff *skb, struct net_device *dev)
 {
     struct net *net = dev_net(dev);
     struct mr_table *mrt;
     struct flowi4 fl4 = {
         .flowi4_oif = dev->ifindex,
         .flowi4_iif = skb->skb_iif ? : LOOPBACK_IFINDEX,
         .flowi4_mark    = skb->mark,
     };
     int err;
 
     err = ipmr_fib_lookup(net, &fl4, &mrt);
     if (err < 0) {
         kfree_skb(skb);
         return err;
     }
 
     dev->stats.tx_bytes += skb->len;
     dev->stats.tx_packets++;
     rcu_read_lock();
 
     /* Pairs with WRITE_ONCE() in vif_add() and vif_delete() */
     ipmr_cache_report(mrt, skb, READ_ONCE(mrt->mroute_reg_vif_num),
               IGMPMSG_WHOLEPKT);
 
     rcu_read_unlock();
     kfree_skb(skb);
     return NETDEV_TX_OK;
 }
 
 static int reg_vif_get_iflink(const struct net_device *dev)
 {
     return 0;
 }
 
 static const struct net_device_ops reg_vif_netdev_ops = {
     .ndo_start_xmit = reg_vif_xmit,
     .ndo_get_iflink = reg_vif_get_iflink,
 };
 
 static void reg_vif_setup(struct net_device *dev)
 {
     dev->type       = ARPHRD_PIMREG;
     dev->mtu        = ETH_DATA_LEN - sizeof(struct iphdr) - 8;
     dev->flags      = IFF_NOARP;
     dev->netdev_ops     = &reg_vif_netdev_ops;
     dev->needs_free_netdev  = true;
     dev->features       |= NETIF_F_NETNS_LOCAL;
 }
 
 static struct net_device *ipmr_reg_vif(struct net *net, struct mr_table *mrt)
 {
     struct net_device *dev;
     char name[IFNAMSIZ];
 
     if (mrt->id == RT_TABLE_DEFAULT)
         sprintf(name, "pimreg");
     else
         sprintf(name, "pimreg%u", mrt->id);
 
     dev = alloc_netdev(0, name, NET_NAME_UNKNOWN, reg_vif_setup);
 
     if (!dev)
         return NULL;
 
     dev_net_set(dev, net);
 
     if (register_netdevice(dev)) {
         free_netdev(dev);
         return NULL;
     }
 
     if (!ipmr_init_vif_indev(dev))
         goto failure;
     if (dev_open(dev, NULL))
         goto failure;
 
     dev_hold(dev);
 
     return dev;
 
 failure:
     unregister_netdevice(dev);
     return NULL;
 }
 
 /* called with rcu_read_lock() */
 static int __pim_rcv(struct mr_table *mrt, struct sk_buff *skb,
              unsigned int pimlen)
 {
     struct net_device *reg_dev = NULL;
     struct iphdr *encap;
     int vif_num;
 
     encap = (struct iphdr *)(skb_transport_header(skb) + pimlen);
     /* Check that:
      * a. packet is really sent to a multicast group
      * b. packet is not a NULL-REGISTER
      * c. packet is not truncated
      */
     if (!ipv4_is_multicast(encap->daddr) ||
         encap->tot_len == 0 ||
         ntohs(encap->tot_len) + pimlen > skb->len)
         return 1;
 
     /* Pairs with WRITE_ONCE() in vif_add()/vid_delete() */
     vif_num = READ_ONCE(mrt->mroute_reg_vif_num);
     if (vif_num >= 0)
         reg_dev = vif_dev_read(&mrt->vif_table[vif_num]);
     if (!reg_dev)
         return 1;
 
     skb->mac_header = skb->network_header;
     skb_pull(skb, (u8 *)encap - skb->data);
     skb_reset_network_header(skb);
     skb->protocol = htons(ETH_P_IP);
     skb->ip_summed = CHECKSUM_NONE;
 
     skb_tunnel_rx(skb, reg_dev, dev_net(reg_dev));
 
     netif_rx(skb);
 
     return NET_RX_SUCCESS;
 }
 #else
 static struct net_device *ipmr_reg_vif(struct net *net, struct mr_table *mrt)
 {
     return NULL;
 }
 #endif
 
 static int call_ipmr_vif_entry_notifiers(struct net *net,
                      enum fib_event_type event_type,
                      struct vif_device *vif,
                      struct net_device *vif_dev,
                      vifi_t vif_index, u32 tb_id)
 {
     return mr_call_vif_notifiers(net, RTNL_FAMILY_IPMR, event_type,
                      vif, vif_dev, vif_index, tb_id,
                      &net->ipv4.ipmr_seq);
 }
 
 static int call_ipmr_mfc_entry_notifiers(struct net *net,
                      enum fib_event_type event_type,
                      struct mfc_cache *mfc, u32 tb_id)
 {
     return mr_call_mfc_notifiers(net, RTNL_FAMILY_IPMR, event_type,
                      &mfc->_c, tb_id, &net->ipv4.ipmr_seq);
 }
 
 /**
  *  vif_delete - Delete a VIF entry
  *  @mrt: Table to delete from
  *  @vifi: VIF identifier to delete
  *  @notify: Set to 1, if the caller is a notifier_call
  *  @head: if unregistering the VIF, place it on this queue
  */
 static int vif_delete(struct mr_table *mrt, int vifi, int notify,
               struct list_head *head)
 {
     struct net *net = read_pnet(&mrt->net);
     struct vif_device *v;
     struct net_device *dev;
     struct in_device *in_dev;
 
     if (vifi < 0 || vifi >= mrt->maxvif)
         return -EADDRNOTAVAIL;
 
     v = &mrt->vif_table[vifi];
 
     dev = rtnl_dereference(v->dev);
     if (!dev)
         return -EADDRNOTAVAIL;
 
     spin_lock(&mrt_lock);
     call_ipmr_vif_entry_notifiers(net, FIB_EVENT_VIF_DEL, v, dev,
                       vifi, mrt->id);
     RCU_INIT_POINTER(v->dev, NULL);
 
     if (vifi == mrt->mroute_reg_vif_num) {
         /* Pairs with READ_ONCE() in ipmr_cache_report() and reg_vif_xmit() */
         WRITE_ONCE(mrt->mroute_reg_vif_num, -1);
     }
     if (vifi + 1 == mrt->maxvif) {
         int tmp;
 
         for (tmp = vifi - 1; tmp >= 0; tmp--) {
             if (VIF_EXISTS(mrt, tmp))
                 break;
         }
         WRITE_ONCE(mrt->maxvif, tmp + 1);
     }
 
     spin_unlock(&mrt_lock);
 
     dev_set_allmulti(dev, -1);
 
     in_dev = __in_dev_get_rtnl(dev);
     if (in_dev) {
         IPV4_DEVCONF(in_dev->cnf, MC_FORWARDING)--;
         inet_netconf_notify_devconf(dev_net(dev), RTM_NEWNETCONF,
                         NETCONFA_MC_FORWARDING,
                         dev->ifindex, &in_dev->cnf);
         ip_rt_multicast_event(in_dev);
     }
 
     if (v->flags & (VIFF_TUNNEL | VIFF_REGISTER) && !notify)
         unregister_netdevice_queue(dev, head);
 
     netdev_put(dev, &v->dev_tracker);
     return 0;
 }
 
 static void ipmr_cache_free_rcu(struct rcu_head *head)
 {
     struct mr_mfc *c = container_of(head, struct mr_mfc, rcu);
 
     kmem_cache_free(mrt_cachep, (struct mfc_cache *)c);
 }
 
 static void ipmr_cache_free(struct mfc_cache *c)
 {
     call_rcu(&c->_c.rcu, ipmr_cache_free_rcu);
 }
 
 /* Destroy an unresolved cache entry, killing queued skbs
  * and reporting error to netlink readers.
  */
 static void ipmr_destroy_unres(struct mr_table *mrt, struct mfc_cache *c)
 {
     struct net *net = read_pnet(&mrt->net);
     struct sk_buff *skb;
     struct nlmsgerr *e;
 
     atomic_dec(&mrt->cache_resolve_queue_len);
 
     while ((skb = skb_dequeue(&c->_c.mfc_un.unres.unresolved))) {
         if (ip_hdr(skb)->version == 0) {
             struct nlmsghdr *nlh = skb_pull(skb,
                             sizeof(struct iphdr));
             nlh->nlmsg_type = NLMSG_ERROR;
             nlh->nlmsg_len = nlmsg_msg_size(sizeof(struct nlmsgerr));
             skb_trim(skb, nlh->nlmsg_len);
             e = nlmsg_data(nlh);
             e->error = -ETIMEDOUT;
             memset(&e->msg, 0, sizeof(e->msg));
 
             rtnl_unicast(skb, net, NETLINK_CB(skb).portid);
         } else {
             kfree_skb(skb);
         }
     }
 
     ipmr_cache_free(c);
 }
 
 /* Timer process for the unresolved queue. */
 static void ipmr_expire_process(struct timer_list *t)
 {
     struct mr_table *mrt = from_timer(mrt, t, ipmr_expire_timer);
     struct mr_mfc *c, *next;
     unsigned long expires;
     unsigned long now;
 
     if (!spin_trylock(&mfc_unres_lock)) {
         mod_timer(&mrt->ipmr_expire_timer, jiffies+HZ/10);
         return;
     }
 
     if (list_empty(&mrt->mfc_unres_queue))
         goto out;
 
     now = jiffies;
     expires = 10*HZ;
 
     list_for_each_entry_safe(c, next, &mrt->mfc_unres_queue, list) {
         if (time_after(c->mfc_un.unres.expires, now)) {
             unsigned long interval = c->mfc_un.unres.expires - now;
             if (interval < expires)
                 expires = interval;
             continue;
         }
 
         list_del(&c->list);
         mroute_netlink_event(mrt, (struct mfc_cache *)c, RTM_DELROUTE);
         ipmr_destroy_unres(mrt, (struct mfc_cache *)c);
     }
 
     if (!list_empty(&mrt->mfc_unres_queue))
         mod_timer(&mrt->ipmr_expire_timer, jiffies + expires);
 
 out:
     spin_unlock(&mfc_unres_lock);
 }
 
 /* Fill oifs list. It is called under locked mrt_lock. */
 static void ipmr_update_thresholds(struct mr_table *mrt, struct mr_mfc *cache,
                    unsigned char *ttls)
 {
     int vifi;
 
     cache->mfc_un.res.minvif = MAXVIFS;
     cache->mfc_un.res.maxvif = 0;
     memset(cache->mfc_un.res.ttls, 255, MAXVIFS);
 
     for (vifi = 0; vifi < mrt->maxvif; vifi++) {
         if (VIF_EXISTS(mrt, vifi) &&
             ttls[vifi] && ttls[vifi] < 255) {
             cache->mfc_un.res.ttls[vifi] = ttls[vifi];
             if (cache->mfc_un.res.minvif > vifi)
                 cache->mfc_un.res.minvif = vifi;
             if (cache->mfc_un.res.maxvif <= vifi)
                 cache->mfc_un.res.maxvif = vifi + 1;
         }
     }
     cache->mfc_un.res.lastuse = jiffies;
 }
 
 static int vif_add(struct net *net, struct mr_table *mrt,
            struct vifctl *vifc, int mrtsock)
 {
     struct netdev_phys_item_id ppid = { };
     int vifi = vifc->vifc_vifi;
     struct vif_device *v = &mrt->vif_table[vifi];
     struct net_device *dev;
     struct in_device *in_dev;
     int err;
 
     /* Is vif busy ? */
     if (VIF_EXISTS(mrt, vifi))
         return -EADDRINUSE;
 
     switch (vifc->vifc_flags) {
     case VIFF_REGISTER:
         if (!ipmr_pimsm_enabled())
             return -EINVAL;
         /* Special Purpose VIF in PIM
          * All the packets will be sent to the daemon
          */
         if (mrt->mroute_reg_vif_num >= 0)
             return -EADDRINUSE;
         dev = ipmr_reg_vif(net, mrt);
         if (!dev)
             return -ENOBUFS;
         err = dev_set_allmulti(dev, 1);
         if (err) {
             unregister_netdevice(dev);
             dev_put(dev);
             return err;
         }
         break;
     case VIFF_TUNNEL:
         dev = ipmr_new_tunnel(net, vifc);
         if (IS_ERR(dev))
             return PTR_ERR(dev);
         break;
     case VIFF_USE_IFINDEX:
     case 0:
         if (vifc->vifc_flags == VIFF_USE_IFINDEX) {
             dev = dev_get_by_index(net, vifc->vifc_lcl_ifindex);
             if (dev && !__in_dev_get_rtnl(dev)) {
                 dev_put(dev);
                 return -EADDRNOTAVAIL;
             }
         } else {
             dev = ip_dev_find(net, vifc->vifc_lcl_addr.s_addr);
         }
         if (!dev)
             return -EADDRNOTAVAIL;
         err = dev_set_allmulti(dev, 1);
         if (err) {
             dev_put(dev);
             return err;
         }
         break;
     default:
         return -EINVAL;
     }
 
     in_dev = __in_dev_get_rtnl(dev);
     if (!in_dev) {
         dev_put(dev);
         return -EADDRNOTAVAIL;
     }
     IPV4_DEVCONF(in_dev->cnf, MC_FORWARDING)++;
     inet_netconf_notify_devconf(net, RTM_NEWNETCONF, NETCONFA_MC_FORWARDING,
                     dev->ifindex, &in_dev->cnf);
     ip_rt_multicast_event(in_dev);
 
     /* Fill in the VIF structures */
     vif_device_init(v, dev, vifc->vifc_rate_limit,
             vifc->vifc_threshold,
             vifc->vifc_flags | (!mrtsock ? VIFF_STATIC : 0),
             (VIFF_TUNNEL | VIFF_REGISTER));
 
     err = dev_get_port_parent_id(dev, &ppid, true);
     if (err == 0) {
         memcpy(v->dev_parent_id.id, ppid.id, ppid.id_len);
         v->dev_parent_id.id_len = ppid.id_len;
     } else {
         v->dev_parent_id.id_len = 0;
     }
 
     v->local = vifc->vifc_lcl_addr.s_addr;
     v->remote = vifc->vifc_rmt_addr.s_addr;
 
     /* And finish update writing critical data */
     spin_lock(&mrt_lock);
     rcu_assign_pointer(v->dev, dev);
     netdev_tracker_alloc(dev, &v->dev_tracker, GFP_ATOMIC);
     if (v->flags & VIFF_REGISTER) {
         /* Pairs with READ_ONCE() in ipmr_cache_report() and reg_vif_xmit() */
         WRITE_ONCE(mrt->mroute_reg_vif_num, vifi);
     }
     if (vifi+1 > mrt->maxvif)
         WRITE_ONCE(mrt->maxvif, vifi + 1);
     spin_unlock(&mrt_lock);
     call_ipmr_vif_entry_notifiers(net, FIB_EVENT_VIF_ADD, v, dev,
                       vifi, mrt->id);
     return 0;
 }
 
 /* called with rcu_read_lock() */
 static struct mfc_cache *ipmr_cache_find(struct mr_table *mrt,
                      __be32 origin,
                      __be32 mcastgrp)
 {
     struct mfc_cache_cmp_arg arg = {
             .mfc_mcastgrp = mcastgrp,
             .mfc_origin = origin
     };
 
     return mr_mfc_find(mrt, &arg);
 }
 
 /* Look for a (*,G) entry */
 static struct mfc_cache *ipmr_cache_find_any(struct mr_table *mrt,
                          __be32 mcastgrp, int vifi)
 {
     struct mfc_cache_cmp_arg arg = {
             .mfc_mcastgrp = mcastgrp,
             .mfc_origin = htonl(INADDR_ANY)
     };
 
     if (mcastgrp == htonl(INADDR_ANY))
         return mr_mfc_find_any_parent(mrt, vifi);
     return mr_mfc_find_any(mrt, vifi, &arg);
 }
 
 /* Look for a (S,G,iif) entry if parent != -1 */
 static struct mfc_cache *ipmr_cache_find_parent(struct mr_table *mrt,
                         __be32 origin, __be32 mcastgrp,
                         int parent)
 {
     struct mfc_cache_cmp_arg arg = {
             .mfc_mcastgrp = mcastgrp,
             .mfc_origin = origin,
     };
 
     return mr_mfc_find_parent(mrt, &arg, parent);
 }
 
 /* Allocate a multicast cache entry */
 static struct mfc_cache *ipmr_cache_alloc(void)
 {
     struct mfc_cache *c = kmem_cache_zalloc(mrt_cachep, GFP_KERNEL);
 
     if (c) {
         c->_c.mfc_un.res.last_assert = jiffies - MFC_ASSERT_THRESH - 1;
         c->_c.mfc_un.res.minvif = MAXVIFS;
         c->_c.free = ipmr_cache_free_rcu;
         refcount_set(&c->_c.mfc_un.res.refcount, 1);
     }
     return c;
 }
 
 static struct mfc_cache *ipmr_cache_alloc_unres(void)
 {
     struct mfc_cache *c = kmem_cache_zalloc(mrt_cachep, GFP_ATOMIC);
 
     if (c) {
         skb_queue_head_init(&c->_c.mfc_un.unres.unresolved);
         c->_c.mfc_un.unres.expires = jiffies + 10 * HZ;
     }
     return c;
 }
 
 /* A cache entry has gone into a resolved state from queued */
 static void ipmr_cache_resolve(struct net *net, struct mr_table *mrt,
                    struct mfc_cache *uc, struct mfc_cache *c)
 {
     struct sk_buff *skb;
     struct nlmsgerr *e;
 
     /* Play the pending entries through our router */
     while ((skb = __skb_dequeue(&uc->_c.mfc_un.unres.unresolved))) {
         if (ip_hdr(skb)->version == 0) {
             struct nlmsghdr *nlh = skb_pull(skb,
                             sizeof(struct iphdr));
 
             if (mr_fill_mroute(mrt, skb, &c->_c,
                        nlmsg_data(nlh)) > 0) {
                 nlh->nlmsg_len = skb_tail_pointer(skb) -
                          (u8 *)nlh;
             } else {
                 nlh->nlmsg_type = NLMSG_ERROR;
                 nlh->nlmsg_len = nlmsg_msg_size(sizeof(struct nlmsgerr));
                 skb_trim(skb, nlh->nlmsg_len);
                 e = nlmsg_data(nlh);
                 e->error = -EMSGSIZE;
                 memset(&e->msg, 0, sizeof(e->msg));
             }
 
             rtnl_unicast(skb, net, NETLINK_CB(skb).portid);
         } else {
             rcu_read_lock();
             ip_mr_forward(net, mrt, skb->dev, skb, c, 0);
             rcu_read_unlock();
         }
     }
 }
 
 /* Bounce a cache query up to mrouted and netlink.
  *
  * Called under rcu_read_lock().
  */
 static int ipmr_cache_report(const struct mr_table *mrt,
                  struct sk_buff *pkt, vifi_t vifi, int assert)
 {
     const int ihl = ip_hdrlen(pkt);
     struct sock *mroute_sk;
     struct igmphdr *igmp;
     struct igmpmsg *msg;
     struct sk_buff *skb;
     int ret;
 
     if (assert == IGMPMSG_WHOLEPKT || assert == IGMPMSG_WRVIFWHOLE)
         skb = skb_realloc_headroom(pkt, sizeof(struct iphdr));
     else
         skb = alloc_skb(128, GFP_ATOMIC);
 
     if (!skb)
         return -ENOBUFS;
 
     if (assert == IGMPMSG_WHOLEPKT || assert == IGMPMSG_WRVIFWHOLE) {
         /* Ugly, but we have no choice with this interface.
          * Duplicate old header, fix ihl, length etc.
          * And all this only to mangle msg->im_msgtype and
          * to set msg->im_mbz to "mbz" :-)
          */
         skb_push(skb, sizeof(struct iphdr));
         skb_reset_network_header(skb);
         skb_reset_transport_header(skb);
         msg = (struct igmpmsg *)skb_network_header(skb);
         memcpy(msg, skb_network_header(pkt), sizeof(struct iphdr));
         msg->im_msgtype = assert;
         msg->im_mbz = 0;
         if (assert == IGMPMSG_WRVIFWHOLE) {
             msg->im_vif = vifi;
             msg->im_vif_hi = vifi >> 8;
         } else {
             /* Pairs with WRITE_ONCE() in vif_add() and vif_delete() */
             int vif_num = READ_ONCE(mrt->mroute_reg_vif_num);
 
             msg->im_vif = vif_num;
             msg->im_vif_hi = vif_num >> 8;
         }
         ip_hdr(skb)->ihl = sizeof(struct iphdr) >> 2;
         ip_hdr(skb)->tot_len = htons(ntohs(ip_hdr(pkt)->tot_len) +
                          sizeof(struct iphdr));
     } else {
         /* Copy the IP header */
         skb_set_network_header(skb, skb->len);
         skb_put(skb, ihl);
         skb_copy_to_linear_data(skb, pkt->data, ihl);
         /* Flag to the kernel this is a route add */
         ip_hdr(skb)->protocol = 0;
         msg = (struct igmpmsg *)skb_network_header(skb);
         msg->im_vif = vifi;
         msg->im_vif_hi = vifi >> 8;
         skb_dst_set(skb, dst_clone(skb_dst(pkt)));
         /* Add our header */
         igmp = skb_put(skb, sizeof(struct igmphdr));
         igmp->type = assert;
         msg->im_msgtype = assert;
         igmp->code = 0;
         ip_hdr(skb)->tot_len = htons(skb->len); /* Fix the length */
         skb->transport_header = skb->network_header;
     }
 
     mroute_sk = rcu_dereference(mrt->mroute_sk);
     if (!mroute_sk) {
         kfree_skb(skb);
         return -EINVAL;
     }
 
     igmpmsg_netlink_event(mrt, skb);
 
     /* Deliver to mrouted */
     ret = sock_queue_rcv_skb(mroute_sk, skb);
 
     if (ret < 0) {
         net_warn_ratelimited("mroute: pending queue full, dropping entries\n");
         kfree_skb(skb);
     }
 
     return ret;
 }
 
 /* Queue a packet for resolution. It gets locked cache entry! */
 /* Called under rcu_read_lock() */
 static int ipmr_cache_unresolved(struct mr_table *mrt, vifi_t vifi,
                  struct sk_buff *skb, struct net_device *dev)
 {
     const struct iphdr *iph = ip_hdr(skb);
     struct mfc_cache *c;
     bool found = false;
     int err;
 
     spin_lock_bh(&mfc_unres_lock);
     list_for_each_entry(c, &mrt->mfc_unres_queue, _c.list) {
         if (c->mfc_mcastgrp == iph->daddr &&
             c->mfc_origin == iph->saddr) {
             found = true;
             break;
         }
     }
 
     if (!found) {
         /* Create a new entry if allowable */
         c = ipmr_cache_alloc_unres();
         if (!c) {
             spin_unlock_bh(&mfc_unres_lock);
 
             kfree_skb(skb);
             return -ENOBUFS;
         }
 
         /* Fill in the new cache entry */
         c->_c.mfc_parent = -1;
         c->mfc_origin   = iph->saddr;
         c->mfc_mcastgrp = iph->daddr;
 
         /* Reflect first query at mrouted. */
         err = ipmr_cache_report(mrt, skb, vifi, IGMPMSG_NOCACHE);
 
         if (err < 0) {
             /* If the report failed throw the cache entry
                out - Brad Parker
              */
             spin_unlock_bh(&mfc_unres_lock);
 
             ipmr_cache_free(c);
             kfree_skb(skb);
             return err;
         }
 
         atomic_inc(&mrt->cache_resolve_queue_len);
         list_add(&c->_c.list, &mrt->mfc_unres_queue);
         mroute_netlink_event(mrt, c, RTM_NEWROUTE);
 
         if (atomic_read(&mrt->cache_resolve_queue_len) == 1)
             mod_timer(&mrt->ipmr_expire_timer,
                   c->_c.mfc_un.unres.expires);
     }
 
     /* See if we can append the packet */
     if (c->_c.mfc_un.unres.unresolved.qlen > 3) {
         kfree_skb(skb);
         err = -ENOBUFS;
     } else {
         if (dev) {
             skb->dev = dev;
             skb->skb_iif = dev->ifindex;
         }
         skb_queue_tail(&c->_c.mfc_un.unres.unresolved, skb);
         err = 0;
     }
 
     spin_unlock_bh(&mfc_unres_lock);
     return err;
 }
 
 /* MFC cache manipulation by user space mroute daemon */
 
 static int ipmr_mfc_delete(struct mr_table *mrt, struct mfcctl *mfc, int parent)
 {
     struct net *net = read_pnet(&mrt->net);
     struct mfc_cache *c;
 
     /* The entries are added/deleted only under RTNL */
     rcu_read_lock();
     c = ipmr_cache_find_parent(mrt, mfc->mfcc_origin.s_addr,
                    mfc->mfcc_mcastgrp.s_addr, parent);
     rcu_read_unlock();
     if (!c)
         return -ENOENT;
     rhltable_remove(&mrt->mfc_hash, &c->_c.mnode, ipmr_rht_params);
     list_del_rcu(&c->_c.list);
     call_ipmr_mfc_entry_notifiers(net, FIB_EVENT_ENTRY_DEL, c, mrt->id);
     mroute_netlink_event(mrt, c, RTM_DELROUTE);
     mr_cache_put(&c->_c);
 
     return 0;
 }
 
 static int ipmr_mfc_add(struct net *net, struct mr_table *mrt,
             struct mfcctl *mfc, int mrtsock, int parent)
 {
     struct mfc_cache *uc, *c;
     struct mr_mfc *_uc;
     bool found;
     int ret;
 
     if (mfc->mfcc_parent >= MAXVIFS)
         return -ENFILE;
 
     /* The entries are added/deleted only under RTNL */
     rcu_read_lock();
     c = ipmr_cache_find_parent(mrt, mfc->mfcc_origin.s_addr,
                    mfc->mfcc_mcastgrp.s_addr, parent);
     rcu_read_unlock();
     if (c) {
         spin_lock(&mrt_lock);
         c->_c.mfc_parent = mfc->mfcc_parent;
         ipmr_update_thresholds(mrt, &c->_c, mfc->mfcc_ttls);
         if (!mrtsock)
             c->_c.mfc_flags |= MFC_STATIC;
         spin_unlock(&mrt_lock);
         call_ipmr_mfc_entry_notifiers(net, FIB_EVENT_ENTRY_REPLACE, c,
                           mrt->id);
         mroute_netlink_event(mrt, c, RTM_NEWROUTE);
         return 0;
     }
 
     if (mfc->mfcc_mcastgrp.s_addr != htonl(INADDR_ANY) &&
         !ipv4_is_multicast(mfc->mfcc_mcastgrp.s_addr))
         return -EINVAL;
 
     c = ipmr_cache_alloc();
     if (!c)
         return -ENOMEM;
 
     c->mfc_origin = mfc->mfcc_origin.s_addr;
     c->mfc_mcastgrp = mfc->mfcc_mcastgrp.s_addr;
     c->_c.mfc_parent = mfc->mfcc_parent;
     ipmr_update_thresholds(mrt, &c->_c, mfc->mfcc_ttls);
     if (!mrtsock)
         c->_c.mfc_flags |= MFC_STATIC;
 
     ret = rhltable_insert_key(&mrt->mfc_hash, &c->cmparg, &c->_c.mnode,
                   ipmr_rht_params);
     if (ret) {
         pr_err("ipmr: rhtable insert error %d\n", ret);
         ipmr_cache_free(c);
         return ret;
     }
     list_add_tail_rcu(&c->_c.list, &mrt->mfc_cache_list);
     /* Check to see if we resolved a queued list. If so we
      * need to send on the frames and tidy up.
      */
     found = false;
     spin_lock_bh(&mfc_unres_lock);
     list_for_each_entry(_uc, &mrt->mfc_unres_queue, list) {
         uc = (struct mfc_cache *)_uc;
         if (uc->mfc_origin == c->mfc_origin &&
             uc->mfc_mcastgrp == c->mfc_mcastgrp) {
             list_del(&_uc->list);
             atomic_dec(&mrt->cache_resolve_queue_len);
             found = true;
             break;
         }
     }
     if (list_empty(&mrt->mfc_unres_queue))
         del_timer(&mrt->ipmr_expire_timer);
     spin_unlock_bh(&mfc_unres_lock);
 
     if (found) {
         ipmr_cache_resolve(net, mrt, uc, c);
         ipmr_cache_free(uc);
     }
     call_ipmr_mfc_entry_notifiers(net, FIB_EVENT_ENTRY_ADD, c, mrt->id);
     mroute_netlink_event(mrt, c, RTM_NEWROUTE);
     return 0;
 }
 
 /* Close the multicast socket, and clear the vif tables etc */
 static void mroute_clean_tables(struct mr_table *mrt, int flags)
 {
     struct net *net = read_pnet(&mrt->net);
     struct mr_mfc *c, *tmp;
     struct mfc_cache *cache;
     LIST_HEAD(list);
     int i;
 
     /* Shut down all active vif entries */
     if (flags & (MRT_FLUSH_VIFS | MRT_FLUSH_VIFS_STATIC)) {
         for (i = 0; i < mrt->maxvif; i++) {
             if (((mrt->vif_table[i].flags & VIFF_STATIC) &&
                  !(flags & MRT_FLUSH_VIFS_STATIC)) ||
                 (!(mrt->vif_table[i].flags & VIFF_STATIC) && !(flags & MRT_FLUSH_VIFS)))
                 continue;
             vif_delete(mrt, i, 0, &list);
         }
         unregister_netdevice_many(&list);
     }
 
     /* Wipe the cache */
     if (flags & (MRT_FLUSH_MFC | MRT_FLUSH_MFC_STATIC)) {
         list_for_each_entry_safe(c, tmp, &mrt->mfc_cache_list, list) {
             if (((c->mfc_flags & MFC_STATIC) && !(flags & MRT_FLUSH_MFC_STATIC)) ||
                 (!(c->mfc_flags & MFC_STATIC) && !(flags & MRT_FLUSH_MFC)))
                 continue;
             rhltable_remove(&mrt->mfc_hash, &c->mnode, ipmr_rht_params);
             list_del_rcu(&c->list);
             cache = (struct mfc_cache *)c;
             call_ipmr_mfc_entry_notifiers(net, FIB_EVENT_ENTRY_DEL, cache,
                               mrt->id);
             mroute_netlink_event(mrt, cache, RTM_DELROUTE);
             mr_cache_put(c);
         }
     }
 
     if (flags & MRT_FLUSH_MFC) {
         if (atomic_read(&mrt->cache_resolve_queue_len) != 0) {
             spin_lock_bh(&mfc_unres_lock);
             list_for_each_entry_safe(c, tmp, &mrt->mfc_unres_queue, list) {
                 list_del(&c->list);
                 cache = (struct mfc_cache *)c;
                 mroute_netlink_event(mrt, cache, RTM_DELROUTE);
                 ipmr_destroy_unres(mrt, cache);
             }
             spin_unlock_bh(&mfc_unres_lock);
         }
     }
 }
 
 /* called from ip_ra_control(), before an RCU grace period,
  * we don't need to call synchronize_rcu() here
  */
 static void mrtsock_destruct(struct sock *sk)
 {
     struct net *net = sock_net(sk);
     struct mr_table *mrt;
 
     rtnl_lock();
     ipmr_for_each_table(mrt, net) {
         if (sk == rtnl_dereference(mrt->mroute_sk)) {
             IPV4_DEVCONF_ALL(net, MC_FORWARDING)--;
             inet_netconf_notify_devconf(net, RTM_NEWNETCONF,
                             NETCONFA_MC_FORWARDING,
                             NETCONFA_IFINDEX_ALL,
                             net->ipv4.devconf_all);
             RCU_INIT_POINTER(mrt->mroute_sk, NULL);
             mroute_clean_tables(mrt, MRT_FLUSH_VIFS | MRT_FLUSH_MFC);
         }
     }
     rtnl_unlock();
 }
 
 /* Socket options and virtual interface manipulation. The whole
  * virtual interface system is a complete heap, but unfortunately
  * that's how BSD mrouted happens to think. Maybe one day with a proper
  * MOSPF/PIM router set up we can clean this up.
  */
 
 int ip_mroute_setsockopt(struct sock *sk, int optname, sockptr_t optval,
              unsigned int optlen)
 {
     struct net *net = sock_net(sk);
     int val, ret = 0, parent = 0;
     struct mr_table *mrt;
     struct vifctl vif;
     struct mfcctl mfc;
     bool do_wrvifwhole;
     u32 uval;
 
     /* There's one exception to the lock - MRT_DONE which needs to unlock */
     rtnl_lock();
     if (sk->sk_type != SOCK_RAW ||
         inet_sk(sk)->inet_num != IPPROTO_IGMP) {
         ret = -EOPNOTSUPP;
         goto out_unlock;
     }
 
     mrt = ipmr_get_table(net, raw_sk(sk)->ipmr_table ? : RT_TABLE_DEFAULT);
     if (!mrt) {
         ret = -ENOENT;
         goto out_unlock;
     }
     if (optname != MRT_INIT) {
         if (sk != rcu_access_pointer(mrt->mroute_sk) &&
             !ns_capable(net->user_ns, CAP_NET_ADMIN)) {
             ret = -EACCES;
             goto out_unlock;
         }
     }
 
     switch (optname) {
     case MRT_INIT:
         if (optlen != sizeof(int)) {
             ret = -EINVAL;
             break;
         }
         if (rtnl_dereference(mrt->mroute_sk)) {
             ret = -EADDRINUSE;
             break;
         }
 
         ret = ip_ra_control(sk, 1, mrtsock_destruct);
         if (ret == 0) {
             rcu_assign_pointer(mrt->mroute_sk, sk);
             IPV4_DEVCONF_ALL(net, MC_FORWARDING)++;
             inet_netconf_notify_devconf(net, RTM_NEWNETCONF,
                             NETCONFA_MC_FORWARDING,
                             NETCONFA_IFINDEX_ALL,
                             net->ipv4.devconf_all);
         }
         break;
     case MRT_DONE:
         if (sk != rcu_access_pointer(mrt->mroute_sk)) {
             ret = -EACCES;
         } else {
             /* We need to unlock here because mrtsock_destruct takes
              * care of rtnl itself and we can't change that due to
              * the IP_ROUTER_ALERT setsockopt which runs without it.
              */
             rtnl_unlock();
             ret = ip_ra_control(sk, 0, NULL);
             goto out;
         }
         break;
     case MRT_ADD_VIF:
     case MRT_DEL_VIF:
         if (optlen != sizeof(vif)) {
             ret = -EINVAL;
             break;
         }
         if (copy_from_sockptr(&vif, optval, sizeof(vif))) {
             ret = -EFAULT;
             break;
         }
         if (vif.vifc_vifi >= MAXVIFS) {
             ret = -ENFILE;
             break;
         }
         if (optname == MRT_ADD_VIF) {
             ret = vif_add(net, mrt, &vif,
                       sk == rtnl_dereference(mrt->mroute_sk));
         } else {
             ret = vif_delete(mrt, vif.vifc_vifi, 0, NULL);
         }
         break;
     /* Manipulate the forwarding caches. These live
      * in a sort of kernel/user symbiosis.
      */
     case MRT_ADD_MFC:
     case MRT_DEL_MFC:
         parent = -1;
         fallthrough;
     case MRT_ADD_MFC_PROXY:
     case MRT_DEL_MFC_PROXY:
         if (optlen != sizeof(mfc)) {
             ret = -EINVAL;
             break;
         }
         if (copy_from_sockptr(&mfc, optval, sizeof(mfc))) {
             ret = -EFAULT;
             break;
         }
         if (parent == 0)
             parent = mfc.mfcc_parent;
         if (optname == MRT_DEL_MFC || optname == MRT_DEL_MFC_PROXY)
             ret = ipmr_mfc_delete(mrt, &mfc, parent);
         else
             ret = ipmr_mfc_add(net, mrt, &mfc,
                        sk == rtnl_dereference(mrt->mroute_sk),
                        parent);
         break;
     case MRT_FLUSH:
         if (optlen != sizeof(val)) {
             ret = -EINVAL;
             break;
         }
         if (copy_from_sockptr(&val, optval, sizeof(val))) {
             ret = -EFAULT;
             break;
         }
         mroute_clean_tables(mrt, val);
         break;
     /* Control PIM assert. */
     case MRT_ASSERT:
         if (optlen != sizeof(val)) {
             ret = -EINVAL;
             break;
         }
         if (copy_from_sockptr(&val, optval, sizeof(val))) {
             ret = -EFAULT;
             break;
         }
         mrt->mroute_do_assert = val;
         break;
     case MRT_PIM:
         if (!ipmr_pimsm_enabled()) {
             ret = -ENOPROTOOPT;
             break;
         }
         if (optlen != sizeof(val)) {
             ret = -EINVAL;
             break;
         }
         if (copy_from_sockptr(&val, optval, sizeof(val))) {
             ret = -EFAULT;
             break;
         }
 
         do_wrvifwhole = (val == IGMPMSG_WRVIFWHOLE);
         val = !!val;
         if (val != mrt->mroute_do_pim) {
             mrt->mroute_do_pim = val;
             mrt->mroute_do_assert = val;
             mrt->mroute_do_wrvifwhole = do_wrvifwhole;
         }
         break;
     case MRT_TABLE:
         if (!IS_BUILTIN(CONFIG_IP_MROUTE_MULTIPLE_TABLES)) {
             ret = -ENOPROTOOPT;
             break;
         }
         if (optlen != sizeof(uval)) {
             ret = -EINVAL;
             break;
         }
         if (copy_from_sockptr(&uval, optval, sizeof(uval))) {
             ret = -EFAULT;
             break;
         }
 
         if (sk == rtnl_dereference(mrt->mroute_sk)) {
             ret = -EBUSY;
         } else {
             mrt = ipmr_new_table(net, uval);
             if (IS_ERR(mrt))
                 ret = PTR_ERR(mrt);
             else
                 raw_sk(sk)->ipmr_table = uval;
         }
         break;
     /* Spurious command, or MRT_VERSION which you cannot set. */
     default:
         ret = -ENOPROTOOPT;
     }
 out_unlock:
     rtnl_unlock();
 out:
     return ret;
 }
 
 /* Getsock opt support for the multicast routing system. */
 int ip_mroute_getsockopt(struct sock *sk, int optname, char __user *optval, int __user *optlen)
 {
     int olr;
     int val;
     struct net *net = sock_net(sk);
     struct mr_table *mrt;
 
     if (sk->sk_type != SOCK_RAW ||
         inet_sk(sk)->inet_num != IPPROTO_IGMP)
         return -EOPNOTSUPP;
 
     mrt = ipmr_get_table(net, raw_sk(sk)->ipmr_table ? : RT_TABLE_DEFAULT);
     if (!mrt)
         return -ENOENT;
 
     switch (optname) {
     case MRT_VERSION:
         val = 0x0305;
         break;
     case MRT_PIM:
         if (!ipmr_pimsm_enabled())
             return -ENOPROTOOPT;
         val = mrt->mroute_do_pim;
         break;
     case MRT_ASSERT:
         val = mrt->mroute_do_assert;
         break;
     default:
         return -ENOPROTOOPT;
     }
 
     if (get_user(olr, optlen))
         return -EFAULT;
     olr = min_t(unsigned int, olr, sizeof(int));
     if (olr < 0)
         return -EINVAL;
     if (put_user(olr, optlen))
         return -EFAULT;
     if (copy_to_user(optval, &val, olr))
         return -EFAULT;
     return 0;
 }
 
 /* The IP multicast ioctl support routines. */
 int ipmr_ioctl(struct sock *sk, int cmd, void __user *arg)
 {
     struct sioc_sg_req sr;
     struct sioc_vif_req vr;
     struct vif_device *vif;
     struct mfc_cache *c;
     struct net *net = sock_net(sk);
     struct mr_table *mrt;
 
     mrt = ipmr_get_table(net, raw_sk(sk)->ipmr_table ? : RT_TABLE_DEFAULT);
     if (!mrt)
         return -ENOENT;
 
     switch (cmd) {
     case SIOCGETVIFCNT:
         if (copy_from_user(&vr, arg, sizeof(vr)))
             return -EFAULT;
         if (vr.vifi >= mrt->maxvif)
             return -EINVAL;
         vr.vifi = array_index_nospec(vr.vifi, mrt->maxvif);
         rcu_read_lock();
         vif = &mrt->vif_table[vr.vifi];
         if (VIF_EXISTS(mrt, vr.vifi)) {
             vr.icount = READ_ONCE(vif->pkt_in);
             vr.ocount = READ_ONCE(vif->pkt_out);
             vr.ibytes = READ_ONCE(vif->bytes_in);
             vr.obytes = READ_ONCE(vif->bytes_out);
             rcu_read_unlock();
 
             if (copy_to_user(arg, &vr, sizeof(vr)))
                 return -EFAULT;
             return 0;
         }
         rcu_read_unlock();
         return -EADDRNOTAVAIL;
     case SIOCGETSGCNT:
         if (copy_from_user(&sr, arg, sizeof(sr)))
             return -EFAULT;
 
         rcu_read_lock();
         c = ipmr_cache_find(mrt, sr.src.s_addr, sr.grp.s_addr);
         if (c) {
             sr.pktcnt = c->_c.mfc_un.res.pkt;
             sr.bytecnt = c->_c.mfc_un.res.bytes;
             sr.wrong_if = c->_c.mfc_un.res.wrong_if;
             rcu_read_unlock();
 
             if (copy_to_user(arg, &sr, sizeof(sr)))
                 return -EFAULT;
             return 0;
         }
         rcu_read_unlock();
         return -EADDRNOTAVAIL;
     default:
         return -ENOIOCTLCMD;
     }
 }
 
 #ifdef CONFIG_COMPAT
 struct compat_sioc_sg_req {
     struct in_addr src;
     struct in_addr grp;
     compat_ulong_t pktcnt;
     compat_ulong_t bytecnt;
     compat_ulong_t wrong_if;
 };
 
 struct compat_sioc_vif_req {
     vifi_t  vifi;       /* Which iface */
     compat_ulong_t icount;
     compat_ulong_t ocount;
     compat_ulong_t ibytes;
     compat_ulong_t obytes;
 };
 
 int ipmr_compat_ioctl(struct sock *sk, unsigned int cmd, void __user *arg)
 {
     struct compat_sioc_sg_req sr;
     struct compat_sioc_vif_req vr;
     struct vif_device *vif;
     struct mfc_cache *c;
     struct net *net = sock_net(sk);
     struct mr_table *mrt;
 
     mrt = ipmr_get_table(net, raw_sk(sk)->ipmr_table ? : RT_TABLE_DEFAULT);
     if (!mrt)
         return -ENOENT;
 
     switch (cmd) {
     case SIOCGETVIFCNT:
         if (copy_from_user(&vr, arg, sizeof(vr)))
             return -EFAULT;
         if (vr.vifi >= mrt->maxvif)
             return -EINVAL;
         vr.vifi = array_index_nospec(vr.vifi, mrt->maxvif);
         rcu_read_lock();
         vif = &mrt->vif_table[vr.vifi];
         if (VIF_EXISTS(mrt, vr.vifi)) {
             vr.icount = READ_ONCE(vif->pkt_in);
             vr.ocount = READ_ONCE(vif->pkt_out);
             vr.ibytes = READ_ONCE(vif->bytes_in);
             vr.obytes = READ_ONCE(vif->bytes_out);
             rcu_read_unlock();
 
             if (copy_to_user(arg, &vr, sizeof(vr)))
                 return -EFAULT;
             return 0;
         }
         rcu_read_unlock();
         return -EADDRNOTAVAIL;
     case SIOCGETSGCNT:
         if (copy_from_user(&sr, arg, sizeof(sr)))
             return -EFAULT;
 
         rcu_read_lock();
         c = ipmr_cache_find(mrt, sr.src.s_addr, sr.grp.s_addr);
         if (c) {
             sr.pktcnt = c->_c.mfc_un.res.pkt;
             sr.bytecnt = c->_c.mfc_un.res.bytes;
             sr.wrong_if = c->_c.mfc_un.res.wrong_if;
             rcu_read_unlock();
 
             if (copy_to_user(arg, &sr, sizeof(sr)))
                 return -EFAULT;
             return 0;
         }
         rcu_read_unlock();
         return -EADDRNOTAVAIL;
     default:
         return -ENOIOCTLCMD;
     }
 }
 #endif
 
 static int ipmr_device_event(struct notifier_block *this, unsigned long event, void *ptr)
 {
     struct net_device *dev = netdev_notifier_info_to_dev(ptr);
     struct net *net = dev_net(dev);
     struct mr_table *mrt;
     struct vif_device *v;
     int ct;
 
     if (event != NETDEV_UNREGISTER)
         return NOTIFY_DONE;
 
     ipmr_for_each_table(mrt, net) {
         v = &mrt->vif_table[0];
         for (ct = 0; ct < mrt->maxvif; ct++, v++) {
             if (rcu_access_pointer(v->dev) == dev)
                 vif_delete(mrt, ct, 1, NULL);
         }
     }
     return NOTIFY_DONE;
 }
 
 static struct notifier_block ip_mr_notifier = {
     .notifier_call = ipmr_device_event,
 };
 
 /* Encapsulate a packet by attaching a valid IPIP header to it.
  * This avoids tunnel drivers and other mess and gives us the speed so
  * important for multicast video.
  */
 static void ip_encap(struct net *net, struct sk_buff *skb,
              __be32 saddr, __be32 daddr)
 {
     struct iphdr *iph;
     const struct iphdr *old_iph = ip_hdr(skb);
 
     skb_push(skb, sizeof(struct iphdr));
     skb->transport_header = skb->network_header;
     skb_reset_network_header(skb);
     iph = ip_hdr(skb);
 
     iph->version    =   4;
     iph->tos    =   old_iph->tos;
     iph->ttl    =   old_iph->ttl;
     iph->frag_off   =   0;
     iph->daddr  =   daddr;
     iph->saddr  =   saddr;
     iph->protocol   =   IPPROTO_IPIP;
     iph->ihl    =   5;
     iph->tot_len    =   htons(skb->len);
     ip_select_ident(net, skb, NULL);
     ip_send_check(iph);
 
     memset(&(IPCB(skb)->opt), 0, sizeof(IPCB(skb)->opt));
     nf_reset_ct(skb);
 }
 
 static inline int ipmr_forward_finish(struct net *net, struct sock *sk,
                       struct sk_buff *skb)
 {
     struct ip_options *opt = &(IPCB(skb)->opt);
 
     IP_INC_STATS(net, IPSTATS_MIB_OUTFORWDATAGRAMS);
     IP_ADD_STATS(net, IPSTATS_MIB_OUTOCTETS, skb->len);
 
     if (unlikely(opt->optlen))
         ip_forward_options(skb);
 
     return dst_output(net, sk, skb);
 }
 
 #ifdef CONFIG_NET_SWITCHDEV
 static bool ipmr_forward_offloaded(struct sk_buff *skb, struct mr_table *mrt,
                    int in_vifi, int out_vifi)
 {
     struct vif_device *out_vif = &mrt->vif_table[out_vifi];
     struct vif_device *in_vif = &mrt->vif_table[in_vifi];
 
     if (!skb->offload_l3_fwd_mark)
         return false;
     if (!out_vif->dev_parent_id.id_len || !in_vif->dev_parent_id.id_len)
         return false;
     return netdev_phys_item_id_same(&out_vif->dev_parent_id,
                     &in_vif->dev_parent_id);
 }
 #else
 static bool ipmr_forward_offloaded(struct sk_buff *skb, struct mr_table *mrt,
                    int in_vifi, int out_vifi)
 {
     return false;
 }
 #endif
 
 /* Processing handlers for ipmr_forward, under rcu_read_lock() */
 
 static void ipmr_queue_xmit(struct net *net, struct mr_table *mrt,
                 int in_vifi, struct sk_buff *skb, int vifi)
 {
     const struct iphdr *iph = ip_hdr(skb);
     struct vif_device *vif = &mrt->vif_table[vifi];
     struct net_device *vif_dev;
     struct net_device *dev;
     struct rtable *rt;
     struct flowi4 fl4;
     int    encap = 0;
 
     vif_dev = vif_dev_read(vif);
     if (!vif_dev)
         goto out_free;
 
     if (vif->flags & VIFF_REGISTER) {
         WRITE_ONCE(vif->pkt_out, vif->pkt_out + 1);
         WRITE_ONCE(vif->bytes_out, vif->bytes_out + skb->len);
         vif_dev->stats.tx_bytes += skb->len;
         vif_dev->stats.tx_packets++;
         ipmr_cache_report(mrt, skb, vifi, IGMPMSG_WHOLEPKT);
         goto out_free;
     }
 
     if (ipmr_forward_offloaded(skb, mrt, in_vifi, vifi))
         goto out_free;
 
     if (vif->flags & VIFF_TUNNEL) {
         rt = ip_route_output_ports(net, &fl4, NULL,
                        vif->remote, vif->local,
                        0, 0,
                        IPPROTO_IPIP,
                        RT_TOS(iph->tos), vif->link);
         if (IS_ERR(rt))
             goto out_free;
         encap = sizeof(struct iphdr);
     } else {
         rt = ip_route_output_ports(net, &fl4, NULL, iph->daddr, 0,
                        0, 0,
                        IPPROTO_IPIP,
                        RT_TOS(iph->tos), vif->link);
         if (IS_ERR(rt))
             goto out_free;
     }
 
     dev = rt->dst.dev;
 
     if (skb->len+encap > dst_mtu(&rt->dst) && (ntohs(iph->frag_off) & IP_DF)) {
         /* Do not fragment multicasts. Alas, IPv4 does not
          * allow to send ICMP, so that packets will disappear
          * to blackhole.
          */
         IP_INC_STATS(net, IPSTATS_MIB_FRAGFAILS);
         ip_rt_put(rt);
         goto out_free;
     }
 
     encap += LL_RESERVED_SPACE(dev) + rt->dst.header_len;
 
     if (skb_cow(skb, encap)) {
         ip_rt_put(rt);
         goto out_free;
     }
 
     WRITE_ONCE(vif->pkt_out, vif->pkt_out + 1);
     WRITE_ONCE(vif->bytes_out, vif->bytes_out + skb->len);
 
     skb_dst_drop(skb);
     skb_dst_set(skb, &rt->dst);
     ip_decrease_ttl(ip_hdr(skb));
 
     /* FIXME: forward and output firewalls used to be called here.
      * What do we do with netfilter? -- RR
      */
     if (vif->flags & VIFF_TUNNEL) {
         ip_encap(net, skb, vif->local, vif->remote);
         /* FIXME: extra output firewall step used to be here. --RR */
         vif_dev->stats.tx_packets++;
         vif_dev->stats.tx_bytes += skb->len;
     }
 
     IPCB(skb)->flags |= IPSKB_FORWARDED;
 
     /* RFC1584 teaches, that DVMRP/PIM router must deliver packets locally
      * not only before forwarding, but after forwarding on all output
      * interfaces. It is clear, if mrouter runs a multicasting
      * program, it should receive packets not depending to what interface
      * program is joined.
      * If we will not make it, the program will have to join on all
      * interfaces. On the other hand, multihoming host (or router, but
      * not mrouter) cannot join to more than one interface - it will
      * result in receiving multiple packets.
      */
     NF_HOOK(NFPROTO_IPV4, NF_INET_FORWARD,
         net, NULL, skb, skb->dev, dev,
         ipmr_forward_finish);
     return;
 
 out_free:
     kfree_skb(skb);
 }
 
 /* Called with mrt_lock or rcu_read_lock() */
 static int ipmr_find_vif(const struct mr_table *mrt, struct net_device *dev)
 {
     int ct;
     /* Pairs with WRITE_ONCE() in vif_delete()/vif_add() */
     for (ct = READ_ONCE(mrt->maxvif) - 1; ct >= 0; ct--) {
         if (rcu_access_pointer(mrt->vif_table[ct].dev) == dev)
             break;
     }
     return ct;
 }
 
 /* "local" means that we should preserve one skb (for local delivery) */
 /* Called uner rcu_read_lock() */
 static void ip_mr_forward(struct net *net, struct mr_table *mrt,
               struct net_device *dev, struct sk_buff *skb,
               struct mfc_cache *c, int local)
 {
     int true_vifi = ipmr_find_vif(mrt, dev);
     int psend = -1;
     int vif, ct;
 
     vif = c->_c.mfc_parent;
     c->_c.mfc_un.res.pkt++;
     c->_c.mfc_un.res.bytes += skb->len;
     c->_c.mfc_un.res.lastuse = jiffies;
 
     if (c->mfc_origin == htonl(INADDR_ANY) && true_vifi >= 0) {
         struct mfc_cache *cache_proxy;
 
         /* For an (*,G) entry, we only check that the incoming
          * interface is part of the static tree.
          */
         cache_proxy = mr_mfc_find_any_parent(mrt, vif);
         if (cache_proxy &&
             cache_proxy->_c.mfc_un.res.ttls[true_vifi] < 255)
             goto forward;
     }
 
     /* Wrong interface: drop packet and (maybe) send PIM assert. */
     if (rcu_access_pointer(mrt->vif_table[vif].dev) != dev) {
         if (rt_is_output_route(skb_rtable(skb))) {
             /* It is our own packet, looped back.
              * Very complicated situation...
              *
              * The best workaround until routing daemons will be
              * fixed is not to redistribute packet, if it was
              * send through wrong interface. It means, that
              * multicast applications WILL NOT work for
              * (S,G), which have default multicast route pointing
              * to wrong oif. In any case, it is not a good
              * idea to use multicasting applications on router.
              */
             goto dont_forward;
         }
 
         c->_c.mfc_un.res.wrong_if++;
 
         if (true_vifi >= 0 && mrt->mroute_do_assert &&
             /* pimsm uses asserts, when switching from RPT to SPT,
              * so that we cannot check that packet arrived on an oif.
              * It is bad, but otherwise we would need to move pretty
              * large chunk of pimd to kernel. Ough... --ANK
              */
             (mrt->mroute_do_pim ||
              c->_c.mfc_un.res.ttls[true_vifi] < 255) &&
             time_after(jiffies,
                    c->_c.mfc_un.res.last_assert +
                    MFC_ASSERT_THRESH)) {
             c->_c.mfc_un.res.last_assert = jiffies;
             ipmr_cache_report(mrt, skb, true_vifi, IGMPMSG_WRONGVIF);
             if (mrt->mroute_do_wrvifwhole)
                 ipmr_cache_report(mrt, skb, true_vifi,
                           IGMPMSG_WRVIFWHOLE);
         }
         goto dont_forward;
     }
 
 forward:
     WRITE_ONCE(mrt->vif_table[vif].pkt_in,
            mrt->vif_table[vif].pkt_in + 1);
     WRITE_ONCE(mrt->vif_table[vif].bytes_in,
            mrt->vif_table[vif].bytes_in + skb->len);
 
     /* Forward the frame */
     if (c->mfc_origin == htonl(INADDR_ANY) &&
         c->mfc_mcastgrp == htonl(INADDR_ANY)) {
         if (true_vifi >= 0 &&
             true_vifi != c->_c.mfc_parent &&
             ip_hdr(skb)->ttl >
                 c->_c.mfc_un.res.ttls[c->_c.mfc_parent]) {
             /* It's an (*,*) entry and the packet is not coming from
              * the upstream: forward the packet to the upstream
              * only.
              */
             psend = c->_c.mfc_parent;
             goto last_forward;
         }
         goto dont_forward;
     }
     for (ct = c->_c.mfc_un.res.maxvif - 1;
          ct >= c->_c.mfc_un.res.minvif; ct--) {
         /* For (*,G) entry, don't forward to the incoming interface */
         if ((c->mfc_origin != htonl(INADDR_ANY) ||
              ct != true_vifi) &&
             ip_hdr(skb)->ttl > c->_c.mfc_un.res.ttls[ct]) {
             if (psend != -1) {
                 struct sk_buff *skb2 = skb_clone(skb, GFP_ATOMIC);
 
                 if (skb2)
                     ipmr_queue_xmit(net, mrt, true_vifi,
                             skb2, psend);
             }
             psend = ct;
         }
     }
 last_forward:
     if (psend != -1) {
         if (local) {
             struct sk_buff *skb2 = skb_clone(skb, GFP_ATOMIC);
 
             if (skb2)
                 ipmr_queue_xmit(net, mrt, true_vifi, skb2,
                         psend);
         } else {
             ipmr_queue_xmit(net, mrt, true_vifi, skb, psend);
             return;
         }
     }
 
 dont_forward:
     if (!local)
         kfree_skb(skb);
 }
 
 static struct mr_table *ipmr_rt_fib_lookup(struct net *net, struct sk_buff *skb)
 {
     struct rtable *rt = skb_rtable(skb);
     struct iphdr *iph = ip_hdr(skb);
     struct flowi4 fl4 = {
         .daddr = iph->daddr,
         .saddr = iph->saddr,
         .flowi4_tos = RT_TOS(iph->tos),
         .flowi4_oif = (rt_is_output_route(rt) ?
                    skb->dev->ifindex : 0),
         .flowi4_iif = (rt_is_output_route(rt) ?
                    LOOPBACK_IFINDEX :
                    skb->dev->ifindex),
         .flowi4_mark = skb->mark,
     };
     struct mr_table *mrt;
     int err;
 
     err = ipmr_fib_lookup(net, &fl4, &mrt);
     if (err)
         return ERR_PTR(err);
     return mrt;
 }
 
 /* Multicast packets for forwarding arrive here
  * Called with rcu_read_lock();
  */
 int ip_mr_input(struct sk_buff *skb)
 {
     struct mfc_cache *cache;
     struct net *net = dev_net(skb->dev);
     int local = skb_rtable(skb)->rt_flags & RTCF_LOCAL;
     struct mr_table *mrt;
     struct net_device *dev;
 
     /* skb->dev passed in is the loX master dev for vrfs.
      * As there are no vifs associated with loopback devices,
      * get the proper interface that does have a vif associated with it.
      */
     dev = skb->dev;
     if (netif_is_l3_master(skb->dev)) {
         dev = dev_get_by_index_rcu(net, IPCB(skb)->iif);
         if (!dev) {
             kfree_skb(skb);
             return -ENODEV;
         }
     }
 
     /* Packet is looped back after forward, it should not be
      * forwarded second time, but still can be delivered locally.
      */
     if (IPCB(skb)->flags & IPSKB_FORWARDED)
         goto dont_forward;
 
     mrt = ipmr_rt_fib_lookup(net, skb);
     if (IS_ERR(mrt)) {
         kfree_skb(skb);
         return PTR_ERR(mrt);
     }
     if (!local) {
         if (IPCB(skb)->opt.router_alert) {
             if (ip_call_ra_chain(skb))
                 return 0;
         } else if (ip_hdr(skb)->protocol == IPPROTO_IGMP) {
             /* IGMPv1 (and broken IGMPv2 implementations sort of
              * Cisco IOS <= 11.2(8)) do not put router alert
              * option to IGMP packets destined to routable
              * groups. It is very bad, because it means
              * that we can forward NO IGMP messages.
              */
             struct sock *mroute_sk;
 
             mroute_sk = rcu_dereference(mrt->mroute_sk);
             if (mroute_sk) {
                 nf_reset_ct(skb);
                 raw_rcv(mroute_sk, skb);
                 return 0;
             }
         }
     }
 
     /* already under rcu_read_lock() */
     cache = ipmr_cache_find(mrt, ip_hdr(skb)->saddr, ip_hdr(skb)->daddr);
     if (!cache) {
         int vif = ipmr_find_vif(mrt, dev);
 
         if (vif >= 0)
             cache = ipmr_cache_find_any(mrt, ip_hdr(skb)->daddr,
                             vif);
     }
 
     /* No usable cache entry */
     if (!cache) {
         int vif;
 
         if (local) {
             struct sk_buff *skb2 = skb_clone(skb, GFP_ATOMIC);
             ip_local_deliver(skb);
             if (!skb2)
                 return -ENOBUFS;
             skb = skb2;
         }
 
         vif = ipmr_find_vif(mrt, dev);
         if (vif >= 0)
             return ipmr_cache_unresolved(mrt, vif, skb, dev);
         kfree_skb(skb);
         return -ENODEV;
     }
 
     ip_mr_forward(net, mrt, dev, skb, cache, local);
 
     if (local)
         return ip_local_deliver(skb);
 
     return 0;
 
 dont_forward:
     if (local)
         return ip_local_deliver(skb);
     kfree_skb(skb);
     return 0;
 }
 
 #ifdef CONFIG_IP_PIMSM_V1
 /* Handle IGMP messages of PIMv1 */
 int pim_rcv_v1(struct sk_buff *skb)
 {
     struct igmphdr *pim;
     struct net *net = dev_net(skb->dev);
     struct mr_table *mrt;
 
     if (!pskb_may_pull(skb, sizeof(*pim) + sizeof(struct iphdr)))
         goto drop;
 
     pim = igmp_hdr(skb);
 
     mrt = ipmr_rt_fib_lookup(net, skb);
     if (IS_ERR(mrt))
         goto drop;
     if (!mrt->mroute_do_pim ||
         pim->group != PIM_V1_VERSION || pim->code != PIM_V1_REGISTER)
         goto drop;
 
     if (__pim_rcv(mrt, skb, sizeof(*pim))) {
 drop:
         kfree_skb(skb);
     }
     return 0;
 }
 #endif
 
 #ifdef CONFIG_IP_PIMSM_V2
 static int pim_rcv(struct sk_buff *skb)
 {
     struct pimreghdr *pim;
     struct net *net = dev_net(skb->dev);
     struct mr_table *mrt;
 
     if (!pskb_may_pull(skb, sizeof(*pim) + sizeof(struct iphdr)))
         goto drop;
 
     pim = (struct pimreghdr *)skb_transport_header(skb);
     if (pim->type != ((PIM_VERSION << 4) | (PIM_TYPE_REGISTER)) ||
         (pim->flags & PIM_NULL_REGISTER) ||
         (ip_compute_csum((void *)pim, sizeof(*pim)) != 0 &&
          csum_fold(skb_checksum(skb, 0, skb->len, 0))))
         goto drop;
 
     mrt = ipmr_rt_fib_lookup(net, skb);
     if (IS_ERR(mrt))
         goto drop;
     if (__pim_rcv(mrt, skb, sizeof(*pim))) {
 drop:
         kfree_skb(skb);
     }
     return 0;
 }
 #endif
 
 int ipmr_get_route(struct net *net, struct sk_buff *skb,
            __be32 saddr, __be32 daddr,
            struct rtmsg *rtm, u32 portid)
 {
     struct mfc_cache *cache;
     struct mr_table *mrt;
     int err;
 
     mrt = ipmr_get_table(net, RT_TABLE_DEFAULT);
     if (!mrt)
         return -ENOENT;
 
     rcu_read_lock();
     cache = ipmr_cache_find(mrt, saddr, daddr);
     if (!cache && skb->dev) {
         int vif = ipmr_find_vif(mrt, skb->dev);
 
         if (vif >= 0)
             cache = ipmr_cache_find_any(mrt, daddr, vif);
     }
     if (!cache) {
         struct sk_buff *skb2;
         struct iphdr *iph;
         struct net_device *dev;
         int vif = -1;
 
         dev = skb->dev;
         if (dev)
             vif = ipmr_find_vif(mrt, dev);
         if (vif < 0) {
             rcu_read_unlock();
             return -ENODEV;
         }
 
         skb2 = skb_realloc_headroom(skb, sizeof(struct iphdr));
         if (!skb2) {
             rcu_read_unlock();
             return -ENOMEM;
         }
 
         NETLINK_CB(skb2).portid = portid;
         skb_push(skb2, sizeof(struct iphdr));
         skb_reset_network_header(skb2);
         iph = ip_hdr(skb2);
         iph->ihl = sizeof(struct iphdr) >> 2;
         iph->saddr = saddr;
         iph->daddr = daddr;
         iph->version = 0;
         err = ipmr_cache_unresolved(mrt, vif, skb2, dev);
         rcu_read_unlock();
         return err;
     }
 
     err = mr_fill_mroute(mrt, skb, &cache->_c, rtm);
     rcu_read_unlock();
     return err;
 }
 
 static int ipmr_fill_mroute(struct mr_table *mrt, struct sk_buff *skb,
                 u32 portid, u32 seq, struct mfc_cache *c, int cmd,
                 int flags)
 {
     struct nlmsghdr *nlh;
     struct rtmsg *rtm;
     int err;
 
     nlh = nlmsg_put(skb, portid, seq, cmd, sizeof(*rtm), flags);
     if (!nlh)
         return -EMSGSIZE;
 
     rtm = nlmsg_data(nlh);
     rtm->rtm_family   = RTNL_FAMILY_IPMR;
     rtm->rtm_dst_len  = 32;
     rtm->rtm_src_len  = 32;
     rtm->rtm_tos      = 0;
     rtm->rtm_table    = mrt->id;
     if (nla_put_u32(skb, RTA_TABLE, mrt->id))
         goto nla_put_failure;
     rtm->rtm_type     = RTN_MULTICAST;
     rtm->rtm_scope    = RT_SCOPE_UNIVERSE;
     if (c->_c.mfc_flags & MFC_STATIC)
         rtm->rtm_protocol = RTPROT_STATIC;
     else
         rtm->rtm_protocol = RTPROT_MROUTED;
     rtm->rtm_flags    = 0;
 
     if (nla_put_in_addr(skb, RTA_SRC, c->mfc_origin) ||
         nla_put_in_addr(skb, RTA_DST, c->mfc_mcastgrp))
         goto nla_put_failure;
     err = mr_fill_mroute(mrt, skb, &c->_c, rtm);
     /* do not break the dump if cache is unresolved */
     if (err < 0 && err != -ENOENT)
         goto nla_put_failure;
 
     nlmsg_end(skb, nlh);
     return 0;
 
 nla_put_failure:
     nlmsg_cancel(skb, nlh);
     return -EMSGSIZE;
 }
 
 static int _ipmr_fill_mroute(struct mr_table *mrt, struct sk_buff *skb,
                  u32 portid, u32 seq, struct mr_mfc *c, int cmd,
                  int flags)
 {
     return ipmr_fill_mroute(mrt, skb, portid, seq, (struct mfc_cache *)c,
                 cmd, flags);
 }
 
 static size_t mroute_msgsize(bool unresolved, int maxvif)
 {
     size_t len =
         NLMSG_ALIGN(sizeof(struct rtmsg))
         + nla_total_size(4) /* RTA_TABLE */
         + nla_total_size(4) /* RTA_SRC */
         + nla_total_size(4) /* RTA_DST */
         ;
 
     if (!unresolved)
         len = len
               + nla_total_size(4)   /* RTA_IIF */
               + nla_total_size(0)   /* RTA_MULTIPATH */
               + maxvif * NLA_ALIGN(sizeof(struct rtnexthop))
                         /* RTA_MFC_STATS */
               + nla_total_size_64bit(sizeof(struct rta_mfc_stats))
         ;
 
     return len;
 }
 
 static void mroute_netlink_event(struct mr_table *mrt, struct mfc_cache *mfc,
                  int cmd)
 {
     struct net *net = read_pnet(&mrt->net);
     struct sk_buff *skb;
     int err = -ENOBUFS;
 
     skb = nlmsg_new(mroute_msgsize(mfc->_c.mfc_parent >= MAXVIFS,
                        mrt->maxvif),
             GFP_ATOMIC);
     if (!skb)
         goto errout;
 
     err = ipmr_fill_mroute(mrt, skb, 0, 0, mfc, cmd, 0);
     if (err < 0)
         goto errout;
 
     rtnl_notify(skb, net, 0, RTNLGRP_IPV4_MROUTE, NULL, GFP_ATOMIC);
     return;
 
 errout:
     kfree_skb(skb);
     if (err < 0)
         rtnl_set_sk_err(net, RTNLGRP_IPV4_MROUTE, err);
 }
 
 static size_t igmpmsg_netlink_msgsize(size_t payloadlen)
 {
     size_t len =
         NLMSG_ALIGN(sizeof(struct rtgenmsg))
         + nla_total_size(1) /* IPMRA_CREPORT_MSGTYPE */
         + nla_total_size(4) /* IPMRA_CREPORT_VIF_ID */
         + nla_total_size(4) /* IPMRA_CREPORT_SRC_ADDR */
         + nla_total_size(4) /* IPMRA_CREPORT_DST_ADDR */
         + nla_total_size(4) /* IPMRA_CREPORT_TABLE */
                     /* IPMRA_CREPORT_PKT */
         + nla_total_size(payloadlen)
         ;
 
     return len;
 }
 
 static void igmpmsg_netlink_event(const struct mr_table *mrt, struct sk_buff *pkt)
 {
     struct net *net = read_pnet(&mrt->net);
     struct nlmsghdr *nlh;
     struct rtgenmsg *rtgenm;
     struct igmpmsg *msg;
     struct sk_buff *skb;
     struct nlattr *nla;
     int payloadlen;
 
     payloadlen = pkt->len - sizeof(struct igmpmsg);
     msg = (struct igmpmsg *)skb_network_header(pkt);
 
     skb = nlmsg_new(igmpmsg_netlink_msgsize(payloadlen), GFP_ATOMIC);
     if (!skb)
         goto errout;
 
     nlh = nlmsg_put(skb, 0, 0, RTM_NEWCACHEREPORT,
             sizeof(struct rtgenmsg), 0);
     if (!nlh)
         goto errout;
     rtgenm = nlmsg_data(nlh);
     rtgenm->rtgen_family = RTNL_FAMILY_IPMR;
     if (nla_put_u8(skb, IPMRA_CREPORT_MSGTYPE, msg->im_msgtype) ||
         nla_put_u32(skb, IPMRA_CREPORT_VIF_ID, msg->im_vif | (msg->im_vif_hi << 8)) ||
         nla_put_in_addr(skb, IPMRA_CREPORT_SRC_ADDR,
                 msg->im_src.s_addr) ||
         nla_put_in_addr(skb, IPMRA_CREPORT_DST_ADDR,
                 msg->im_dst.s_addr) ||
         nla_put_u32(skb, IPMRA_CREPORT_TABLE, mrt->id))
         goto nla_put_failure;
 
     nla = nla_reserve(skb, IPMRA_CREPORT_PKT, payloadlen);
     if (!nla || skb_copy_bits(pkt, sizeof(struct igmpmsg),
                   nla_data(nla), payloadlen))
         goto nla_put_failure;
 
     nlmsg_end(skb, nlh);
 
     rtnl_notify(skb, net, 0, RTNLGRP_IPV4_MROUTE_R, NULL, GFP_ATOMIC);
     return;
 
 nla_put_failure:
     nlmsg_cancel(skb, nlh);
 errout:
     kfree_skb(skb);
     rtnl_set_sk_err(net, RTNLGRP_IPV4_MROUTE_R, -ENOBUFS);
 }
 
 static int ipmr_rtm_valid_getroute_req(struct sk_buff *skb,
                        const struct nlmsghdr *nlh,
                        struct nlattr **tb,
                        struct netlink_ext_ack *extack)
 {
     struct rtmsg *rtm;
     int i, err;
 
     if (nlh->nlmsg_len < nlmsg_msg_size(sizeof(*rtm))) {
         NL_SET_ERR_MSG(extack, "ipv4: Invalid header for multicast route get request");
         return -EINVAL;
     }
 
     if (!netlink_strict_get_check(skb))
         return nlmsg_parse_deprecated(nlh, sizeof(*rtm), tb, RTA_MAX,
                           rtm_ipv4_policy, extack);
 
     rtm = nlmsg_data(nlh);
     if ((rtm->rtm_src_len && rtm->rtm_src_len != 32) ||
         (rtm->rtm_dst_len && rtm->rtm_dst_len != 32) ||
         rtm->rtm_tos || rtm->rtm_table || rtm->rtm_protocol ||
         rtm->rtm_scope || rtm->rtm_type || rtm->rtm_flags) {
         NL_SET_ERR_MSG(extack, "ipv4: Invalid values in header for multicast route get request");
         return -EINVAL;
     }
 
     err = nlmsg_parse_deprecated_strict(nlh, sizeof(*rtm), tb, RTA_MAX,
                         rtm_ipv4_policy, extack);
     if (err)
         return err;
 
     if ((tb[RTA_SRC] && !rtm->rtm_src_len) ||
         (tb[RTA_DST] && !rtm->rtm_dst_len)) {
         NL_SET_ERR_MSG(extack, "ipv4: rtm_src_len and rtm_dst_len must be 32 for IPv4");
         return -EINVAL;
     }
 
     for (i = 0; i <= RTA_MAX; i++) {
         if (!tb[i])
             continue;
 
         switch (i) {
         case RTA_SRC:
         case RTA_DST:
         case RTA_TABLE:
             break;
         default:
             NL_SET_ERR_MSG(extack, "ipv4: Unsupported attribute in multicast route get request");
             return -EINVAL;
         }
     }
 
     return 0;
 }
 
 static int ipmr_rtm_getroute(struct sk_buff *in_skb, struct nlmsghdr *nlh,
                  struct netlink_ext_ack *extack)
 {
     struct net *net = sock_net(in_skb->sk);
     struct nlattr *tb[RTA_MAX + 1];
     struct sk_buff *skb = NULL;
     struct mfc_cache *cache;
     struct mr_table *mrt;
     __be32 src, grp;
     u32 tableid;
     int err;
 
     err = ipmr_rtm_valid_getroute_req(in_skb, nlh, tb, extack);
     if (err < 0)
         goto errout;
 
     src = tb[RTA_SRC] ? nla_get_in_addr(tb[RTA_SRC]) : 0;
     grp = tb[RTA_DST] ? nla_get_in_addr(tb[RTA_DST]) : 0;
     tableid = tb[RTA_TABLE] ? nla_get_u32(tb[RTA_TABLE]) : 0;
 
     mrt = ipmr_get_table(net, tableid ? tableid : RT_TABLE_DEFAULT);
     if (!mrt) {
         err = -ENOENT;
         goto errout_free;
     }
 
     /* entries are added/deleted only under RTNL */
     rcu_read_lock();
     cache = ipmr_cache_find(mrt, src, grp);
     rcu_read_unlock();
     if (!cache) {
         err = -ENOENT;
         goto errout_free;
     }
 
     skb = nlmsg_new(mroute_msgsize(false, mrt->maxvif), GFP_KERNEL);
     if (!skb) {
         err = -ENOBUFS;
         goto errout_free;
     }
 
     err = ipmr_fill_mroute(mrt, skb, NETLINK_CB(in_skb).portid,
                    nlh->nlmsg_seq, cache,
                    RTM_NEWROUTE, 0);
     if (err < 0)
         goto errout_free;
 
     err = rtnl_unicast(skb, net, NETLINK_CB(in_skb).portid);
 
 errout:
     return err;
 
 errout_free:
     kfree_skb(skb);
     goto errout;
 }
 
 static int ipmr_rtm_dumproute(struct sk_buff *skb, struct netlink_callback *cb)
 {
     struct fib_dump_filter filter = {};
     int err;
 
     if (cb->strict_check) {
         err = ip_valid_fib_dump_req(sock_net(skb->sk), cb->nlh,
                         &filter, cb);
         if (err < 0)
             return err;
     }
 
     if (filter.table_id) {
         struct mr_table *mrt;
 
         mrt = ipmr_get_table(sock_net(skb->sk), filter.table_id);
         if (!mrt) {
             if (rtnl_msg_family(cb->nlh) != RTNL_FAMILY_IPMR)
                 return skb->len;
 
             NL_SET_ERR_MSG(cb->extack, "ipv4: MR table does not exist");
             return -ENOENT;
         }
         err = mr_table_dump(mrt, skb, cb, _ipmr_fill_mroute,
                     &mfc_unres_lock, &filter);
         return skb->len ? : err;
     }
 
     return mr_rtm_dumproute(skb, cb, ipmr_mr_table_iter,
                 _ipmr_fill_mroute, &mfc_unres_lock, &filter);
 }
 
 static const struct nla_policy rtm_ipmr_policy[RTA_MAX + 1] = {
     [RTA_SRC]   = { .type = NLA_U32 },
     [RTA_DST]   = { .type = NLA_U32 },
     [RTA_IIF]   = { .type = NLA_U32 },
     [RTA_TABLE] = { .type = NLA_U32 },
     [RTA_MULTIPATH] = { .len = sizeof(struct rtnexthop) },
 };
 
 static bool ipmr_rtm_validate_proto(unsigned char rtm_protocol)
 {
     switch (rtm_protocol) {
     case RTPROT_STATIC:
     case RTPROT_MROUTED:
         return true;
     }
     return false;
 }
 
 static int ipmr_nla_get_ttls(const struct nlattr *nla, struct mfcctl *mfcc)
 {
     struct rtnexthop *rtnh = nla_data(nla);
     int remaining = nla_len(nla), vifi = 0;
 
     while (rtnh_ok(rtnh, remaining)) {
         mfcc->mfcc_ttls[vifi] = rtnh->rtnh_hops;
         if (++vifi == MAXVIFS)
             break;
         rtnh = rtnh_next(rtnh, &remaining);
     }
 
     return remaining > 0 ? -EINVAL : vifi;
 }
 
 /* returns < 0 on error, 0 for ADD_MFC and 1 for ADD_MFC_PROXY */
 static int rtm_to_ipmr_mfcc(struct net *net, struct nlmsghdr *nlh,
                 struct mfcctl *mfcc, int *mrtsock,
                 struct mr_table **mrtret,
                 struct netlink_ext_ack *extack)
 {
     struct net_device *dev = NULL;
     u32 tblid = RT_TABLE_DEFAULT;
     struct mr_table *mrt;
     struct nlattr *attr;
     struct rtmsg *rtm;
     int ret, rem;
 
     ret = nlmsg_validate_deprecated(nlh, sizeof(*rtm), RTA_MAX,
                     rtm_ipmr_policy, extack);
     if (ret < 0)
         goto out;
     rtm = nlmsg_data(nlh);
 
     ret = -EINVAL;
     if (rtm->rtm_family != RTNL_FAMILY_IPMR || rtm->rtm_dst_len != 32 ||
         rtm->rtm_type != RTN_MULTICAST ||
         rtm->rtm_scope != RT_SCOPE_UNIVERSE ||
         !ipmr_rtm_validate_proto(rtm->rtm_protocol))
         goto out;
 
     memset(mfcc, 0, sizeof(*mfcc));
     mfcc->mfcc_parent = -1;
     ret = 0;
     nlmsg_for_each_attr(attr, nlh, sizeof(struct rtmsg), rem) {
         switch (nla_type(attr)) {
         case RTA_SRC:
             mfcc->mfcc_origin.s_addr = nla_get_be32(attr);
             break;
         case RTA_DST:
             mfcc->mfcc_mcastgrp.s_addr = nla_get_be32(attr);
             break;
         case RTA_IIF:
             dev = __dev_get_by_index(net, nla_get_u32(attr));
             if (!dev) {
                 ret = -ENODEV;
                 goto out;
             }
             break;
         case RTA_MULTIPATH:
             if (ipmr_nla_get_ttls(attr, mfcc) < 0) {
                 ret = -EINVAL;
                 goto out;
             }
             break;
         case RTA_PREFSRC:
             ret = 1;
             break;
         case RTA_TABLE:
             tblid = nla_get_u32(attr);
             break;
         }
     }
     mrt = ipmr_get_table(net, tblid);
     if (!mrt) {
         ret = -ENOENT;
         goto out;
     }
     *mrtret = mrt;
     *mrtsock = rtm->rtm_protocol == RTPROT_MROUTED ? 1 : 0;
     if (dev)
         mfcc->mfcc_parent = ipmr_find_vif(mrt, dev);
 
 out:
     return ret;
 }
 
 /* takes care of both newroute and delroute */
 static int ipmr_rtm_route(struct sk_buff *skb, struct nlmsghdr *nlh,
               struct netlink_ext_ack *extack)
 {
     struct net *net = sock_net(skb->sk);
     int ret, mrtsock, parent;
     struct mr_table *tbl;
     struct mfcctl mfcc;
 
     mrtsock = 0;
     tbl = NULL;
     ret = rtm_to_ipmr_mfcc(net, nlh, &mfcc, &mrtsock, &tbl, extack);
     if (ret < 0)
         return ret;
 
     parent = ret ? mfcc.mfcc_parent : -1;
     if (nlh->nlmsg_type == RTM_NEWROUTE)
         return ipmr_mfc_add(net, tbl, &mfcc, mrtsock, parent);
     else
         return ipmr_mfc_delete(tbl, &mfcc, parent);
 }
 
 static bool ipmr_fill_table(struct mr_table *mrt, struct sk_buff *skb)
 {
     u32 queue_len = atomic_read(&mrt->cache_resolve_queue_len);
 
     if (nla_put_u32(skb, IPMRA_TABLE_ID, mrt->id) ||
         nla_put_u32(skb, IPMRA_TABLE_CACHE_RES_QUEUE_LEN, queue_len) ||
         nla_put_s32(skb, IPMRA_TABLE_MROUTE_REG_VIF_NUM,
             mrt->mroute_reg_vif_num) ||
         nla_put_u8(skb, IPMRA_TABLE_MROUTE_DO_ASSERT,
                mrt->mroute_do_assert) ||
         nla_put_u8(skb, IPMRA_TABLE_MROUTE_DO_PIM, mrt->mroute_do_pim) ||
         nla_put_u8(skb, IPMRA_TABLE_MROUTE_DO_WRVIFWHOLE,
                mrt->mroute_do_wrvifwhole))
         return false;
 
     return true;
 }
 
 static bool ipmr_fill_vif(struct mr_table *mrt, u32 vifid, struct sk_buff *skb)
 {
     struct net_device *vif_dev;
     struct nlattr *vif_nest;
     struct vif_device *vif;
 
     vif = &mrt->vif_table[vifid];
     vif_dev = rtnl_dereference(vif->dev);
     /* if the VIF doesn't exist just continue */
     if (!vif_dev)
         return true;
 
     vif_nest = nla_nest_start_noflag(skb, IPMRA_VIF);
     if (!vif_nest)
         return false;
 
     if (nla_put_u32(skb, IPMRA_VIFA_IFINDEX, vif_dev->ifindex) ||
         nla_put_u32(skb, IPMRA_VIFA_VIF_ID, vifid) ||
         nla_put_u16(skb, IPMRA_VIFA_FLAGS, vif->flags) ||
         nla_put_u64_64bit(skb, IPMRA_VIFA_BYTES_IN, vif->bytes_in,
                   IPMRA_VIFA_PAD) ||
         nla_put_u64_64bit(skb, IPMRA_VIFA_BYTES_OUT, vif->bytes_out,
                   IPMRA_VIFA_PAD) ||
         nla_put_u64_64bit(skb, IPMRA_VIFA_PACKETS_IN, vif->pkt_in,
                   IPMRA_VIFA_PAD) ||
         nla_put_u64_64bit(skb, IPMRA_VIFA_PACKETS_OUT, vif->pkt_out,
                   IPMRA_VIFA_PAD) ||
         nla_put_be32(skb, IPMRA_VIFA_LOCAL_ADDR, vif->local) ||
         nla_put_be32(skb, IPMRA_VIFA_REMOTE_ADDR, vif->remote)) {
         nla_nest_cancel(skb, vif_nest);
         return false;
     }
     nla_nest_end(skb, vif_nest);
 
     return true;
 }
 
 static int ipmr_valid_dumplink(const struct nlmsghdr *nlh,
                    struct netlink_ext_ack *extack)
 {
     struct ifinfomsg *ifm;
 
     if (nlh->nlmsg_len < nlmsg_msg_size(sizeof(*ifm))) {
         NL_SET_ERR_MSG(extack, "ipv4: Invalid header for ipmr link dump");
         return -EINVAL;
     }
 
     if (nlmsg_attrlen(nlh, sizeof(*ifm))) {
         NL_SET_ERR_MSG(extack, "Invalid data after header in ipmr link dump");
         return -EINVAL;
     }
 
     ifm = nlmsg_data(nlh);
     if (ifm->__ifi_pad || ifm->ifi_type || ifm->ifi_flags ||
         ifm->ifi_change || ifm->ifi_index) {
         NL_SET_ERR_MSG(extack, "Invalid values in header for ipmr link dump request");
         return -EINVAL;
     }
 
     return 0;
 }
 
 static int ipmr_rtm_dumplink(struct sk_buff *skb, struct netlink_callback *cb)
 {
     struct net *net = sock_net(skb->sk);
     struct nlmsghdr *nlh = NULL;
     unsigned int t = 0, s_t;
     unsigned int e = 0, s_e;
     struct mr_table *mrt;
 
     if (cb->strict_check) {
         int err = ipmr_valid_dumplink(cb->nlh, cb->extack);
 
         if (err < 0)
             return err;
     }
 
     s_t = cb->args[0];
     s_e = cb->args[1];
 
     ipmr_for_each_table(mrt, net) {
         struct nlattr *vifs, *af;
         struct ifinfomsg *hdr;
         u32 i;
 
         if (t < s_t)
             goto skip_table;
         nlh = nlmsg_put(skb, NETLINK_CB(cb->skb).portid,
                 cb->nlh->nlmsg_seq, RTM_NEWLINK,
                 sizeof(*hdr), NLM_F_MULTI);
         if (!nlh)
             break;
 
         hdr = nlmsg_data(nlh);
         memset(hdr, 0, sizeof(*hdr));
         hdr->ifi_family = RTNL_FAMILY_IPMR;
 
         af = nla_nest_start_noflag(skb, IFLA_AF_SPEC);
         if (!af) {
             nlmsg_cancel(skb, nlh);
             goto out;
         }
 
         if (!ipmr_fill_table(mrt, skb)) {
             nlmsg_cancel(skb, nlh);
             goto out;
         }
 
         vifs = nla_nest_start_noflag(skb, IPMRA_TABLE_VIFS);
         if (!vifs) {
             nla_nest_end(skb, af);
             nlmsg_end(skb, nlh);
             goto out;
         }
         for (i = 0; i < mrt->maxvif; i++) {
             if (e < s_e)
                 goto skip_entry;
             if (!ipmr_fill_vif(mrt, i, skb)) {
                 nla_nest_end(skb, vifs);
                 nla_nest_end(skb, af);
                 nlmsg_end(skb, nlh);
                 goto out;
             }
 skip_entry:
             e++;
         }
         s_e = 0;
         e = 0;
         nla_nest_end(skb, vifs);
         nla_nest_end(skb, af);
         nlmsg_end(skb, nlh);
 skip_table:
         t++;
     }
 
 out:
     cb->args[1] = e;
     cb->args[0] = t;
 
     return skb->len;
 }
 
 #ifdef CONFIG_PROC_FS
 /* The /proc interfaces to multicast routing :
  * /proc/net/ip_mr_cache & /proc/net/ip_mr_vif
  */
 
 static void *ipmr_vif_seq_start(struct seq_file *seq, loff_t *pos)
     __acquires(RCU)
 {
     struct mr_vif_iter *iter = seq->private;
     struct net *net = seq_file_net(seq);
     struct mr_table *mrt;
 
     mrt = ipmr_get_table(net, RT_TABLE_DEFAULT);
     if (!mrt)
         return ERR_PTR(-ENOENT);
 
     iter->mrt = mrt;
 
     rcu_read_lock();
     return mr_vif_seq_start(seq, pos);
 }
 
 static void ipmr_vif_seq_stop(struct seq_file *seq, void *v)
     __releases(RCU)
 {
     rcu_read_unlock();
 }
 
 static int ipmr_vif_seq_show(struct seq_file *seq, void *v)
 {
     struct mr_vif_iter *iter = seq->private;
     struct mr_table *mrt = iter->mrt;
 
     if (v == SEQ_START_TOKEN) {
         seq_puts(seq,
              "Interface      BytesIn  PktsIn  BytesOut PktsOut Flags Local    Remote\n");
     } else {
         const struct vif_device *vif = v;
         const struct net_device *vif_dev;
         const char *name;
 
         vif_dev = vif_dev_read(vif);
         name = vif_dev ? vif_dev->name : "none";
         seq_printf(seq,
                "%2td %-10s %8ld %7ld  %8ld %7ld %05X %08X %08X\n",
                vif - mrt->vif_table,
                name, vif->bytes_in, vif->pkt_in,
                vif->bytes_out, vif->pkt_out,
                vif->flags, vif->local, vif->remote);
     }
     return 0;
 }
 
 static const struct seq_operations ipmr_vif_seq_ops = {
     .start = ipmr_vif_seq_start,
     .next  = mr_vif_seq_next,
     .stop  = ipmr_vif_seq_stop,
     .show  = ipmr_vif_seq_show,
 };
 
 static void *ipmr_mfc_seq_start(struct seq_file *seq, loff_t *pos)
 {
     struct net *net = seq_file_net(seq);
     struct mr_table *mrt;
 
     mrt = ipmr_get_table(net, RT_TABLE_DEFAULT);
     if (!mrt)
         return ERR_PTR(-ENOENT);
 
     return mr_mfc_seq_start(seq, pos, mrt, &mfc_unres_lock);
 }
 
 static int ipmr_mfc_seq_show(struct seq_file *seq, void *v)
 {
     int n;
 
     if (v == SEQ_START_TOKEN) {
         seq_puts(seq,
          "Group    Origin   Iif     Pkts    Bytes    Wrong Oifs\n");
     } else {
         const struct mfc_cache *mfc = v;
         const struct mr_mfc_iter *it = seq->private;
         const struct mr_table *mrt = it->mrt;
 
         seq_printf(seq, "%08X %08X %-3hd",
                (__force u32) mfc->mfc_mcastgrp,
                (__force u32) mfc->mfc_origin,
                mfc->_c.mfc_parent);
 
         if (it->cache != &mrt->mfc_unres_queue) {
             seq_printf(seq, " %8lu %8lu %8lu",
                    mfc->_c.mfc_un.res.pkt,
                    mfc->_c.mfc_un.res.bytes,
                    mfc->_c.mfc_un.res.wrong_if);
             for (n = mfc->_c.mfc_un.res.minvif;
                  n < mfc->_c.mfc_un.res.maxvif; n++) {
                 if (VIF_EXISTS(mrt, n) &&
                     mfc->_c.mfc_un.res.ttls[n] < 255)
                     seq_printf(seq,
                        " %2d:%-3d",
                        n, mfc->_c.mfc_un.res.ttls[n]);
             }
         } else {
             /* unresolved mfc_caches don't contain
              * pkt, bytes and wrong_if values
              */
             seq_printf(seq, " %8lu %8lu %8lu", 0ul, 0ul, 0ul);
         }
         seq_putc(seq, '\n');
     }
     return 0;
 }
 
 static const struct seq_operations ipmr_mfc_seq_ops = {
     .start = ipmr_mfc_seq_start,
     .next  = mr_mfc_seq_next,
     .stop  = mr_mfc_seq_stop,
     .show  = ipmr_mfc_seq_show,
 };
 #endif
 
 #ifdef CONFIG_IP_PIMSM_V2
 static const struct net_protocol pim_protocol = {
     .handler    =   pim_rcv,
 };
 #endif
 
 static unsigned int ipmr_seq_read(struct net *net)
 {
     ASSERT_RTNL();
 
     return net->ipv4.ipmr_seq + ipmr_rules_seq_read(net);
 }
 
 static int ipmr_dump(struct net *net, struct notifier_block *nb,
              struct netlink_ext_ack *extack)
 {
     return mr_dump(net, nb, RTNL_FAMILY_IPMR, ipmr_rules_dump,
                ipmr_mr_table_iter, extack);
 }
 
 static const struct fib_notifier_ops ipmr_notifier_ops_template = {
     .family     = RTNL_FAMILY_IPMR,
     .fib_seq_read   = ipmr_seq_read,
     .fib_dump   = ipmr_dump,
     .owner      = THIS_MODULE,
 };
 
 static int __net_init ipmr_notifier_init(struct net *net)
 {
     struct fib_notifier_ops *ops;
 
     net->ipv4.ipmr_seq = 0;
 
     ops = fib_notifier_ops_register(&ipmr_notifier_ops_template, net);
     if (IS_ERR(ops))
         return PTR_ERR(ops);
     net->ipv4.ipmr_notifier_ops = ops;
 
     return 0;
 }
 
 static void __net_exit ipmr_notifier_exit(struct net *net)
 {
     fib_notifier_ops_unregister(net->ipv4.ipmr_notifier_ops);
     net->ipv4.ipmr_notifier_ops = NULL;
 }
 
 /* Setup for IP multicast routing */
 static int __net_init ipmr_net_init(struct net *net)
 {
     int err;
 
     err = ipmr_notifier_init(net);
     if (err)
         goto ipmr_notifier_fail;
 
     err = ipmr_rules_init(net);
     if (err < 0)
         goto ipmr_rules_fail;
 
 #ifdef CONFIG_PROC_FS
     err = -ENOMEM;
     if (!proc_create_net("ip_mr_vif", 0, net->proc_net, &ipmr_vif_seq_ops,
             sizeof(struct mr_vif_iter)))
         goto proc_vif_fail;
     if (!proc_create_net("ip_mr_cache", 0, net->proc_net, &ipmr_mfc_seq_ops,
             sizeof(struct mr_mfc_iter)))
         goto proc_cache_fail;
 #endif
     return 0;
 
 #ifdef CONFIG_PROC_FS
 proc_cache_fail:
     remove_proc_entry("ip_mr_vif", net->proc_net);
 proc_vif_fail:
     rtnl_lock();
     ipmr_rules_exit(net);
     rtnl_unlock();
 #endif
 ipmr_rules_fail:
     ipmr_notifier_exit(net);
 ipmr_notifier_fail:
     return err;
 }
 
 static void __net_exit ipmr_net_exit(struct net *net)
 {
 #ifdef CONFIG_PROC_FS
     remove_proc_entry("ip_mr_cache", net->proc_net);
     remove_proc_entry("ip_mr_vif", net->proc_net);
 #endif
     ipmr_notifier_exit(net);
 }
 
 static void __net_exit ipmr_net_exit_batch(struct list_head *net_list)
 {
     struct net *net;
 
     rtnl_lock();
     list_for_each_entry(net, net_list, exit_list)
         ipmr_rules_exit(net);
     rtnl_unlock();
 }
 
 static struct pernet_operations ipmr_net_ops = {
     .init = ipmr_net_init,
     .exit = ipmr_net_exit,
     .exit_batch = ipmr_net_exit_batch,
 };
 
 int __init ip_mr_init(void)
 {
     int err;
 
     mrt_cachep = kmem_cache_create("ip_mrt_cache",
                        sizeof(struct mfc_cache),
                        0, SLAB_HWCACHE_ALIGN | SLAB_PANIC,
                        NULL);
 
     err = register_pernet_subsys(&ipmr_net_ops);
     if (err)
         goto reg_pernet_fail;
 
     err = register_netdevice_notifier(&ip_mr_notifier);
     if (err)
         goto reg_notif_fail;
 #ifdef CONFIG_IP_PIMSM_V2
     if (inet_add_protocol(&pim_protocol, IPPROTO_PIM) < 0) {
         pr_err("%s: can't add PIM protocol\n", __func__);
         err = -EAGAIN;
         goto add_proto_fail;
     }
 #endif
     rtnl_register(RTNL_FAMILY_IPMR, RTM_GETROUTE,
               ipmr_rtm_getroute, ipmr_rtm_dumproute, 0);
     rtnl_register(RTNL_FAMILY_IPMR, RTM_NEWROUTE,
               ipmr_rtm_route, NULL, 0);
     rtnl_register(RTNL_FAMILY_IPMR, RTM_DELROUTE,
               ipmr_rtm_route, NULL, 0);
 
     rtnl_register(RTNL_FAMILY_IPMR, RTM_GETLINK,
               NULL, ipmr_rtm_dumplink, 0);
     return 0;
 
 #ifdef CONFIG_IP_PIMSM_V2
 add_proto_fail:
     unregister_netdevice_notifier(&ip_mr_notifier);
 #endif
 reg_notif_fail:
     unregister_pernet_subsys(&ipmr_net_ops);
 reg_pernet_fail:
     kmem_cache_destroy(mrt_cachep);
     return err;
 }