/* net/tipc/udp_media.c: IP bearer support for TIPC * * Copyright (c) 2015, Ericsson AB * All rights reserved. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions are met: * * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * 3. Neither the names of the copyright holders nor the names of its * contributors may be used to endorse or promote products derived from * this software without specific prior written permission. * * Alternatively, this software may be distributed under the terms of the * GNU General Public License ("GPL") version 2 as published by the Free * Software Foundation. * * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE * POSSIBILITY OF SUCH DAMAGE. */ #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include "core.h" #include "addr.h" #include "net.h" #include "bearer.h" #include "netlink.h" #include "msg.h" /* IANA assigned UDP port */ #define UDP_PORT_DEFAULT 6118 #define UDP_MIN_HEADROOM 48 /** * struct udp_media_addr - IP/UDP addressing information * * This is the bearer level originating address used in neighbor discovery * messages, and all fields should be in network byte order */ struct udp_media_addr { __be16 proto; __be16 port; union { struct in_addr ipv4; struct in6_addr ipv6; }; }; /* struct udp_replicast - container for UDP remote addresses */ struct udp_replicast { struct udp_media_addr addr; struct dst_cache dst_cache; struct rcu_head rcu; struct list_head list; }; /** * struct udp_bearer - ip/udp bearer data structure * @bearer: associated generic tipc bearer * @ubsock: bearer associated socket * @ifindex: local address scope * @work: used to schedule deferred work on a bearer */ struct udp_bearer { struct tipc_bearer __rcu *bearer; struct socket *ubsock; u32 ifindex; struct work_struct work; struct udp_replicast rcast; }; static int tipc_udp_is_mcast_addr(struct udp_media_addr *addr) { if (ntohs(addr->proto) == ETH_P_IP) return ipv4_is_multicast(addr->ipv4.s_addr); #if IS_ENABLED(CONFIG_IPV6) else return ipv6_addr_is_multicast(&addr->ipv6); #endif return 0; } /* udp_media_addr_set - convert a ip/udp address to a TIPC media address */ static void tipc_udp_media_addr_set(struct tipc_media_addr *addr, struct udp_media_addr *ua) { memset(addr, 0, sizeof(struct tipc_media_addr)); addr->media_id = TIPC_MEDIA_TYPE_UDP; memcpy(addr->value, ua, sizeof(struct udp_media_addr)); if (tipc_udp_is_mcast_addr(ua)) addr->broadcast = TIPC_BROADCAST_SUPPORT; } /* tipc_udp_addr2str - convert ip/udp address to string */ static int tipc_udp_addr2str(struct tipc_media_addr *a, char *buf, int size) { struct udp_media_addr *ua = (struct udp_media_addr *)&a->value; if (ntohs(ua->proto) == ETH_P_IP) snprintf(buf, size, "%pI4:%u", &ua->ipv4, ntohs(ua->port)); else if (ntohs(ua->proto) == ETH_P_IPV6) snprintf(buf, size, "%pI6:%u", &ua->ipv6, ntohs(ua->port)); else pr_err("Invalid UDP media address\n"); return 0; } /* tipc_udp_msg2addr - extract an ip/udp address from a TIPC ndisc message */ static int tipc_udp_msg2addr(struct tipc_bearer *b, struct tipc_media_addr *a, char *msg) { struct udp_media_addr *ua; ua = (struct udp_media_addr *) (msg + TIPC_MEDIA_ADDR_OFFSET); if (msg[TIPC_MEDIA_TYPE_OFFSET] != TIPC_MEDIA_TYPE_UDP) return -EINVAL; tipc_udp_media_addr_set(a, ua); return 0; } /* tipc_udp_addr2msg - write an ip/udp address to a TIPC ndisc message */ static int tipc_udp_addr2msg(char *msg, struct tipc_media_addr *a) { memset(msg, 0, TIPC_MEDIA_INFO_SIZE); msg[TIPC_MEDIA_TYPE_OFFSET] = TIPC_MEDIA_TYPE_UDP; memcpy(msg + TIPC_MEDIA_ADDR_OFFSET, a->value, sizeof(struct udp_media_addr)); return 0; } /* tipc_send_msg - enqueue a send request */ static int tipc_udp_xmit(struct net *net, struct sk_buff *skb, struct udp_bearer *ub, struct udp_media_addr *src, struct udp_media_addr *dst, struct dst_cache *cache) { struct dst_entry *ndst = dst_cache_get(cache); int ttl, err = 0; if (dst->proto == htons(ETH_P_IP)) { struct rtable *rt = (struct rtable *)ndst; if (!rt) { struct flowi4 fl = { .daddr = dst->ipv4.s_addr, .saddr = src->ipv4.s_addr, .flowi4_mark = skb->mark, .flowi4_proto = IPPROTO_UDP }; rt = ip_route_output_key(net, &fl); if (IS_ERR(rt)) { err = PTR_ERR(rt); goto tx_error; } dst_cache_set_ip4(cache, &rt->dst, fl.saddr); } ttl = ip4_dst_hoplimit(&rt->dst); udp_tunnel_xmit_skb(rt, ub->ubsock->sk, skb, src->ipv4.s_addr, dst->ipv4.s_addr, 0, ttl, 0, src->port, dst->port, false, true); #if IS_ENABLED(CONFIG_IPV6) } else { if (!ndst) { struct flowi6 fl6 = { .flowi6_oif = ub->ifindex, .daddr = dst->ipv6, .saddr = src->ipv6, .flowi6_proto = IPPROTO_UDP }; ndst = ipv6_stub->ipv6_dst_lookup_flow(net, ub->ubsock->sk, &fl6, NULL); if (IS_ERR(ndst)) { err = PTR_ERR(ndst); goto tx_error; } dst_cache_set_ip6(cache, ndst, &fl6.saddr); } ttl = ip6_dst_hoplimit(ndst); err = udp_tunnel6_xmit_skb(ndst, ub->ubsock->sk, skb, NULL, &src->ipv6, &dst->ipv6, 0, ttl, 0, src->port, dst->port, false); #endif } return err; tx_error: kfree_skb(skb); return err; } static int tipc_udp_send_msg(struct net *net, struct sk_buff *skb, struct tipc_bearer *b, struct tipc_media_addr *addr) { struct udp_media_addr *src = (struct udp_media_addr *)&b->addr.value; struct udp_media_addr *dst = (struct udp_media_addr *)&addr->value; struct udp_replicast *rcast; struct udp_bearer *ub; int err = 0; if (skb_headroom(skb) < UDP_MIN_HEADROOM) { err = pskb_expand_head(skb, UDP_MIN_HEADROOM, 0, GFP_ATOMIC); if (err) goto out; } skb_set_inner_protocol(skb, htons(ETH_P_TIPC)); ub = rcu_dereference(b->media_ptr); if (!ub) { err = -ENODEV; goto out; } if (addr->broadcast != TIPC_REPLICAST_SUPPORT) return tipc_udp_xmit(net, skb, ub, src, dst, &ub->rcast.dst_cache); /* Replicast, send an skb to each configured IP address */ list_for_each_entry_rcu(rcast, &ub->rcast.list, list) { struct sk_buff *_skb; _skb = pskb_copy(skb, GFP_ATOMIC); if (!_skb) { err = -ENOMEM; goto out; } err = tipc_udp_xmit(net, _skb, ub, src, &rcast->addr, &rcast->dst_cache); if (err) goto out; } err = 0; out: kfree_skb(skb); return err; } static bool tipc_udp_is_known_peer(struct tipc_bearer *b, struct udp_media_addr *addr) { struct udp_replicast *rcast, *tmp; struct udp_bearer *ub; ub = rcu_dereference_rtnl(b->media_ptr); if (!ub) { pr_err_ratelimited("UDP bearer instance not found\n"); return false; } list_for_each_entry_safe(rcast, tmp, &ub->rcast.list, list) { if (!memcmp(&rcast->addr, addr, sizeof(struct udp_media_addr))) return true; } return false; } static int tipc_udp_rcast_add(struct tipc_bearer *b, struct udp_media_addr *addr) { struct udp_replicast *rcast; struct udp_bearer *ub; ub = rcu_dereference_rtnl(b->media_ptr); if (!ub) return -ENODEV; rcast = kmalloc(sizeof(*rcast), GFP_ATOMIC); if (!rcast) return -ENOMEM; if (dst_cache_init(&rcast->dst_cache, GFP_ATOMIC)) { kfree(rcast); return -ENOMEM; } memcpy(&rcast->addr, addr, sizeof(struct udp_media_addr)); if (ntohs(addr->proto) == ETH_P_IP) pr_info("New replicast peer: %pI4\n", &rcast->addr.ipv4); #if IS_ENABLED(CONFIG_IPV6) else if (ntohs(addr->proto) == ETH_P_IPV6) pr_info("New replicast peer: %pI6\n", &rcast->addr.ipv6); #endif b->bcast_addr.broadcast = TIPC_REPLICAST_SUPPORT; list_add_rcu(&rcast->list, &ub->rcast.list); return 0; } static int tipc_udp_rcast_disc(struct tipc_bearer *b, struct sk_buff *skb) { struct udp_media_addr src = {0}; struct udp_media_addr *dst; dst = (struct udp_media_addr *)&b->bcast_addr.value; if (tipc_udp_is_mcast_addr(dst)) return 0; src.port = udp_hdr(skb)->source; if (ip_hdr(skb)->version == 4) { struct iphdr *iphdr = ip_hdr(skb); src.proto = htons(ETH_P_IP); src.ipv4.s_addr = iphdr->saddr; if (ipv4_is_multicast(iphdr->daddr)) return 0; #if IS_ENABLED(CONFIG_IPV6) } else if (ip_hdr(skb)->version == 6) { struct ipv6hdr *iphdr = ipv6_hdr(skb); src.proto = htons(ETH_P_IPV6); src.ipv6 = iphdr->saddr; if (ipv6_addr_is_multicast(&iphdr->daddr)) return 0; #endif } else { return 0; } if (likely(tipc_udp_is_known_peer(b, &src))) return 0; return tipc_udp_rcast_add(b, &src); } /* tipc_udp_recv - read data from bearer socket */ static int tipc_udp_recv(struct sock *sk, struct sk_buff *skb) { struct udp_bearer *ub; struct tipc_bearer *b; struct tipc_msg *hdr; int err; ub = rcu_dereference_sk_user_data(sk); if (!ub) { pr_err_ratelimited("Failed to get UDP bearer reference"); goto out; } skb_pull(skb, sizeof(struct udphdr)); hdr = buf_msg(skb); b = rcu_dereference(ub->bearer); if (!b) goto out; if (b && test_bit(0, &b->up)) { TIPC_SKB_CB(skb)->flags = 0; tipc_rcv(sock_net(sk), skb, b); return 0; } if (unlikely(msg_user(hdr) == LINK_CONFIG)) { err = tipc_udp_rcast_disc(b, skb); if (err) goto out; } out: kfree_skb(skb); return 0; } static int enable_mcast(struct udp_bearer *ub, struct udp_media_addr *remote) { int err = 0; struct ip_mreqn mreqn; struct sock *sk = ub->ubsock->sk; if (ntohs(remote->proto) == ETH_P_IP) { mreqn.imr_multiaddr = remote->ipv4; mreqn.imr_ifindex = ub->ifindex; err = ip_mc_join_group(sk, &mreqn); #if IS_ENABLED(CONFIG_IPV6) } else { err = ipv6_stub->ipv6_sock_mc_join(sk, ub->ifindex, &remote->ipv6); #endif } return err; } static int __tipc_nl_add_udp_addr(struct sk_buff *skb, struct udp_media_addr *addr, int nla_t) { if (ntohs(addr->proto) == ETH_P_IP) { struct sockaddr_in ip4; memset(&ip4, 0, sizeof(ip4)); ip4.sin_family = AF_INET; ip4.sin_port = addr->port; ip4.sin_addr.s_addr = addr->ipv4.s_addr; if (nla_put(skb, nla_t, sizeof(ip4), &ip4)) return -EMSGSIZE; #if IS_ENABLED(CONFIG_IPV6) } else if (ntohs(addr->proto) == ETH_P_IPV6) { struct sockaddr_in6 ip6; memset(&ip6, 0, sizeof(ip6)); ip6.sin6_family = AF_INET6; ip6.sin6_port = addr->port; memcpy(&ip6.sin6_addr, &addr->ipv6, sizeof(struct in6_addr)); if (nla_put(skb, nla_t, sizeof(ip6), &ip6)) return -EMSGSIZE; #endif } return 0; } int tipc_udp_nl_dump_remoteip(struct sk_buff *skb, struct netlink_callback *cb) { u32 bid = cb->args[0]; u32 skip_cnt = cb->args[1]; u32 portid = NETLINK_CB(cb->skb).portid; struct udp_replicast *rcast, *tmp; struct tipc_bearer *b; struct udp_bearer *ub; void *hdr; int err; int i; if (!bid && !skip_cnt) { struct nlattr **attrs = genl_dumpit_info(cb)->attrs; struct net *net = sock_net(skb->sk); struct nlattr *battrs[TIPC_NLA_BEARER_MAX + 1]; char *bname; if (!attrs[TIPC_NLA_BEARER]) return -EINVAL; err = nla_parse_nested_deprecated(battrs, TIPC_NLA_BEARER_MAX, attrs[TIPC_NLA_BEARER], tipc_nl_bearer_policy, NULL); if (err) return err; if (!battrs[TIPC_NLA_BEARER_NAME]) return -EINVAL; bname = nla_data(battrs[TIPC_NLA_BEARER_NAME]); rtnl_lock(); b = tipc_bearer_find(net, bname); if (!b) { rtnl_unlock(); return -EINVAL; } bid = b->identity; } else { struct net *net = sock_net(skb->sk); struct tipc_net *tn = net_generic(net, tipc_net_id); rtnl_lock(); b = rtnl_dereference(tn->bearer_list[bid]); if (!b) { rtnl_unlock(); return -EINVAL; } } ub = rtnl_dereference(b->media_ptr); if (!ub) { rtnl_unlock(); return -EINVAL; } i = 0; list_for_each_entry_safe(rcast, tmp, &ub->rcast.list, list) { if (i < skip_cnt) goto count; hdr = genlmsg_put(skb, portid, cb->nlh->nlmsg_seq, &tipc_genl_family, NLM_F_MULTI, TIPC_NL_BEARER_GET); if (!hdr) goto done; err = __tipc_nl_add_udp_addr(skb, &rcast->addr, TIPC_NLA_UDP_REMOTE); if (err) { genlmsg_cancel(skb, hdr); goto done; } genlmsg_end(skb, hdr); count: i++; } done: rtnl_unlock(); cb->args[0] = bid; cb->args[1] = i; return skb->len; } int tipc_udp_nl_add_bearer_data(struct tipc_nl_msg *msg, struct tipc_bearer *b) { struct udp_media_addr *src = (struct udp_media_addr *)&b->addr.value; struct udp_media_addr *dst; struct udp_bearer *ub; struct nlattr *nest; ub = rtnl_dereference(b->media_ptr); if (!ub) return -ENODEV; nest = nla_nest_start_noflag(msg->skb, TIPC_NLA_BEARER_UDP_OPTS); if (!nest) goto msg_full; if (__tipc_nl_add_udp_addr(msg->skb, src, TIPC_NLA_UDP_LOCAL)) goto msg_full; dst = (struct udp_media_addr *)&b->bcast_addr.value; if (__tipc_nl_add_udp_addr(msg->skb, dst, TIPC_NLA_UDP_REMOTE)) goto msg_full; if (!list_empty(&ub->rcast.list)) { if (nla_put_flag(msg->skb, TIPC_NLA_UDP_MULTI_REMOTEIP)) goto msg_full; } nla_nest_end(msg->skb, nest); return 0; msg_full: nla_nest_cancel(msg->skb, nest); return -EMSGSIZE; } /** * tipc_parse_udp_addr - build udp media address from netlink data * @nlattr: netlink attribute containing sockaddr storage aligned address * @addr: tipc media address to fill with address, port and protocol type * @scope_id: IPv6 scope id pointer, not NULL indicates it's required */ static int tipc_parse_udp_addr(struct nlattr *nla, struct udp_media_addr *addr, u32 *scope_id) { struct sockaddr_storage sa; nla_memcpy(&sa, nla, sizeof(sa)); if (sa.ss_family == AF_INET) { struct sockaddr_in *ip4 = (struct sockaddr_in *)&sa; addr->proto = htons(ETH_P_IP); addr->port = ip4->sin_port; addr->ipv4.s_addr = ip4->sin_addr.s_addr; return 0; #if IS_ENABLED(CONFIG_IPV6) } else if (sa.ss_family == AF_INET6) { struct sockaddr_in6 *ip6 = (struct sockaddr_in6 *)&sa; addr->proto = htons(ETH_P_IPV6); addr->port = ip6->sin6_port; memcpy(&addr->ipv6, &ip6->sin6_addr, sizeof(struct in6_addr)); /* Scope ID is only interesting for local addresses */ if (scope_id) { int atype; atype = ipv6_addr_type(&ip6->sin6_addr); if (__ipv6_addr_needs_scope_id(atype) && !ip6->sin6_scope_id) { return -EINVAL; } *scope_id = ip6->sin6_scope_id ? : 0; } return 0; #endif } return -EADDRNOTAVAIL; } int tipc_udp_nl_bearer_add(struct tipc_bearer *b, struct nlattr *attr) { int err; struct udp_media_addr addr = {0}; struct nlattr *opts[TIPC_NLA_UDP_MAX + 1]; struct udp_media_addr *dst; if (nla_parse_nested_deprecated(opts, TIPC_NLA_UDP_MAX, attr, tipc_nl_udp_policy, NULL)) return -EINVAL; if (!opts[TIPC_NLA_UDP_REMOTE]) return -EINVAL; err = tipc_parse_udp_addr(opts[TIPC_NLA_UDP_REMOTE], &addr, NULL); if (err) return err; dst = (struct udp_media_addr *)&b->bcast_addr.value; if (tipc_udp_is_mcast_addr(dst)) { pr_err("Can't add remote ip to TIPC UDP multicast bearer\n"); return -EINVAL; } if (tipc_udp_is_known_peer(b, &addr)) return 0; return tipc_udp_rcast_add(b, &addr); } /** * tipc_udp_enable - callback to create a new udp bearer instance * @net: network namespace * @b: pointer to generic tipc_bearer * @attrs: netlink bearer configuration * * validate the bearer parameters and initialize the udp bearer * rtnl_lock should be held */ static int tipc_udp_enable(struct net *net, struct tipc_bearer *b, struct nlattr *attrs[]) { int err = -EINVAL; struct udp_bearer *ub; struct udp_media_addr remote = {0}; struct udp_media_addr local = {0}; struct udp_port_cfg udp_conf = {0}; struct udp_tunnel_sock_cfg tuncfg = {NULL}; struct nlattr *opts[TIPC_NLA_UDP_MAX + 1]; u8 node_id[NODE_ID_LEN] = {0,}; int rmcast = 0; ub = kzalloc(sizeof(*ub), GFP_ATOMIC); if (!ub) return -ENOMEM; INIT_LIST_HEAD(&ub->rcast.list); if (!attrs[TIPC_NLA_BEARER_UDP_OPTS]) goto err; if (nla_parse_nested_deprecated(opts, TIPC_NLA_UDP_MAX, attrs[TIPC_NLA_BEARER_UDP_OPTS], tipc_nl_udp_policy, NULL)) goto err; if (!opts[TIPC_NLA_UDP_LOCAL] || !opts[TIPC_NLA_UDP_REMOTE]) { pr_err("Invalid UDP bearer configuration"); err = -EINVAL; goto err; } err = tipc_parse_udp_addr(opts[TIPC_NLA_UDP_LOCAL], &local, &ub->ifindex); if (err) goto err; err = tipc_parse_udp_addr(opts[TIPC_NLA_UDP_REMOTE], &remote, NULL); if (err) goto err; if (remote.proto != local.proto) { err = -EINVAL; goto err; } /* Checking remote ip address */ rmcast = tipc_udp_is_mcast_addr(&remote); /* Autoconfigure own node identity if needed */ if (!tipc_own_id(net)) { memcpy(node_id, local.ipv6.in6_u.u6_addr8, 16); tipc_net_init(net, node_id, 0); } if (!tipc_own_id(net)) { pr_warn("Failed to set node id, please configure manually\n"); err = -EINVAL; goto err; } b->bcast_addr.media_id = TIPC_MEDIA_TYPE_UDP; b->bcast_addr.broadcast = TIPC_BROADCAST_SUPPORT; rcu_assign_pointer(b->media_ptr, ub); rcu_assign_pointer(ub->bearer, b); tipc_udp_media_addr_set(&b->addr, &local); if (local.proto == htons(ETH_P_IP)) { struct net_device *dev; dev = __ip_dev_find(net, local.ipv4.s_addr, false); if (!dev) { err = -ENODEV; goto err; } udp_conf.family = AF_INET; /* Switch to use ANY to receive packets from group */ if (rmcast) udp_conf.local_ip.s_addr = htonl(INADDR_ANY); else udp_conf.local_ip.s_addr = local.ipv4.s_addr; udp_conf.use_udp_checksums = false; ub->ifindex = dev->ifindex; if (tipc_mtu_bad(dev, sizeof(struct iphdr) + sizeof(struct udphdr))) { err = -EINVAL; goto err; } b->mtu = b->media->mtu; #if IS_ENABLED(CONFIG_IPV6) } else if (local.proto == htons(ETH_P_IPV6)) { udp_conf.family = AF_INET6; udp_conf.use_udp6_tx_checksums = true; udp_conf.use_udp6_rx_checksums = true; if (rmcast) udp_conf.local_ip6 = in6addr_any; else udp_conf.local_ip6 = local.ipv6; b->mtu = 1280; #endif } else { err = -EAFNOSUPPORT; goto err; } udp_conf.local_udp_port = local.port; err = udp_sock_create(net, &udp_conf, &ub->ubsock); if (err) goto err; tuncfg.sk_user_data = ub; tuncfg.encap_type = 1; tuncfg.encap_rcv = tipc_udp_recv; tuncfg.encap_destroy = NULL; setup_udp_tunnel_sock(net, ub->ubsock, &tuncfg); err = dst_cache_init(&ub->rcast.dst_cache, GFP_ATOMIC); if (err) goto free; /** * The bcast media address port is used for all peers and the ip * is used if it's a multicast address. */ memcpy(&b->bcast_addr.value, &remote, sizeof(remote)); if (rmcast) err = enable_mcast(ub, &remote); else err = tipc_udp_rcast_add(b, &remote); if (err) goto free; return 0; free: dst_cache_destroy(&ub->rcast.dst_cache); udp_tunnel_sock_release(ub->ubsock); err: kfree(ub); return err; } /* cleanup_bearer - break the socket/bearer association */ static void cleanup_bearer(struct work_struct *work) { struct udp_bearer *ub = container_of(work, struct udp_bearer, work); struct udp_replicast *rcast, *tmp; list_for_each_entry_safe(rcast, tmp, &ub->rcast.list, list) { dst_cache_destroy(&rcast->dst_cache); list_del_rcu(&rcast->list); kfree_rcu(rcast, rcu); } dst_cache_destroy(&ub->rcast.dst_cache); udp_tunnel_sock_release(ub->ubsock); synchronize_net(); kfree(ub); } /* tipc_udp_disable - detach bearer from socket */ static void tipc_udp_disable(struct tipc_bearer *b) { struct udp_bearer *ub; ub = rtnl_dereference(b->media_ptr); if (!ub) { pr_err("UDP bearer instance not found\n"); return; } sock_set_flag(ub->ubsock->sk, SOCK_DEAD); RCU_INIT_POINTER(ub->bearer, NULL); /* sock_release need to be done outside of rtnl lock */ INIT_WORK(&ub->work, cleanup_bearer); schedule_work(&ub->work); } struct tipc_media udp_media_info = { .send_msg = tipc_udp_send_msg, .enable_media = tipc_udp_enable, .disable_media = tipc_udp_disable, .addr2str = tipc_udp_addr2str, .addr2msg = tipc_udp_addr2msg, .msg2addr = tipc_udp_msg2addr, .priority = TIPC_DEF_LINK_PRI, .tolerance = TIPC_DEF_LINK_TOL, .window = TIPC_DEF_LINK_WIN, .mtu = TIPC_DEF_LINK_UDP_MTU, .type_id = TIPC_MEDIA_TYPE_UDP, .hwaddr_len = 0, .name = "udp" };