net/tipc/udp_media.c

   1 /* net/tipc/udp_media.c: IP bearer support for TIPC
   2  *
   3  * Copyright (c) 2015, Ericsson AB
   4  * All rights reserved.
   5  *
   6  * Redistribution and use in source and binary forms, with or without
   7  * modification, are permitted provided that the following conditions are met:
   8  *
   9  * 1. Redistributions of source code must retain the above copyright
  10  *    notice, this list of conditions and the following disclaimer.
  11  * 2. Redistributions in binary form must reproduce the above copyright
  12  *    notice, this list of conditions and the following disclaimer in the
  13  *    documentation and/or other materials provided with the distribution.
  14  * 3. Neither the names of the copyright holders nor the names of its
  15  *    contributors may be used to endorse or promote products derived from
  16  *    this software without specific prior written permission.
  17  *
  18  * Alternatively, this software may be distributed under the terms of the
  19  * GNU General Public License ("GPL") version 2 as published by the Free
  20  * Software Foundation.
  21  *
  22  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
  23  * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  24  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  25  * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
  26  * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
  27  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
  28  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
  29  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
  30  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
  31  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
  32  * POSSIBILITY OF SUCH DAMAGE.
  33  */
  34
  35 #include <linux/socket.h>
  36 #include <linux/ip.h>
  37 #include <linux/udp.h>
  38 #include <linux/inet.h>
  39 #include <linux/inetdevice.h>
  40 #include <linux/igmp.h>
  41 #include <linux/kernel.h>
  42 #include <linux/workqueue.h>
  43 #include <linux/list.h>
  44 #include <net/sock.h>
  45 #include <net/ip.h>
  46 #include <net/udp_tunnel.h>
  47 #include <net/addrconf.h>
  48 #include <linux/tipc_netlink.h>
  49 #include "core.h"
  50 #include "bearer.h"
  51 #include "netlink.h"
  52 #include "msg.h"
  53
  54 /* IANA assigned UDP port */
  55 #define UDP_PORT_DEFAULT        6118
  56
  57 #define UDP_MIN_HEADROOM        48
  58
  59 /**
  60  * struct udp_media_addr - IP/UDP addressing information
  61  *
  62  * This is the bearer level originating address used in neighbor discovery
  63  * messages, and all fields should be in network byte order
  64  */
  65 struct udp_media_addr {
  66         __be16  proto;
  67         __be16  port;
  68         union {
  69                 struct in_addr ipv4;
  70                 struct in6_addr ipv6;
  71         };
  72 };
  73
  74 /* struct udp_replicast - container for UDP remote addresses */
  75 struct udp_replicast {
  76         struct udp_media_addr addr;
  77         struct rcu_head rcu;
  78         struct list_head list;
  79 };
  80
  81 /**
  82  * struct udp_bearer - ip/udp bearer data structure
  83  * @bearer:     associated generic tipc bearer
  84  * @ubsock:     bearer associated socket
  85  * @ifindex:    local address scope
  86  * @work:       used to schedule deferred work on a bearer
  87  */
  88 struct udp_bearer {
  89         struct tipc_bearer __rcu *bearer;
  90         struct socket *ubsock;
  91         u32 ifindex;
  92         struct work_struct work;
  93         struct udp_replicast rcast;
  94 };
  95
  96 static int tipc_udp_is_mcast_addr(struct udp_media_addr *addr)
  97 {
  98         if (ntohs(addr->proto) == ETH_P_IP)
  99                 return ipv4_is_multicast(addr->ipv4.s_addr);
 100 #if IS_ENABLED(CONFIG_IPV6)
 101         else
 102                 return ipv6_addr_is_multicast(&addr->ipv6);
 103 #endif
 104         return 0;
 105 }
 106
 107 /* udp_media_addr_set - convert a ip/udp address to a TIPC media address */
 108 static void tipc_udp_media_addr_set(struct tipc_media_addr *addr,
 109                                     struct udp_media_addr *ua)
 110 {
 111         memset(addr, 0, sizeof(struct tipc_media_addr));
 112         addr->media_id = TIPC_MEDIA_TYPE_UDP;
 113         memcpy(addr->value, ua, sizeof(struct udp_media_addr));
 114
 115         if (tipc_udp_is_mcast_addr(ua))
 116                 addr->broadcast = TIPC_BROADCAST_SUPPORT;
 117 }
 118
 119 /* tipc_udp_addr2str - convert ip/udp address to string */
 120 static int tipc_udp_addr2str(struct tipc_media_addr *a, char *buf, int size)
 121 {
 122         struct udp_media_addr *ua = (struct udp_media_addr *)&a->value;
 123
 124         if (ntohs(ua->proto) == ETH_P_IP)
 125                 snprintf(buf, size, "%pI4:%u", &ua->ipv4, ntohs(ua->port));
 126         else if (ntohs(ua->proto) == ETH_P_IPV6)
 127                 snprintf(buf, size, "%pI6:%u", &ua->ipv6, ntohs(ua->port));
 128         else
 129                 pr_err("Invalid UDP media address\n");
 130         return 0;
 131 }
 132
 133 /* tipc_udp_msg2addr - extract an ip/udp address from a TIPC ndisc message */
 134 static int tipc_udp_msg2addr(struct tipc_bearer *b, struct tipc_media_addr *a,
 135                              char *msg)
 136 {
 137         struct udp_media_addr *ua;
 138
 139         ua = (struct udp_media_addr *) (msg + TIPC_MEDIA_ADDR_OFFSET);
 140         if (msg[TIPC_MEDIA_TYPE_OFFSET] != TIPC_MEDIA_TYPE_UDP)
 141                 return -EINVAL;
 142         tipc_udp_media_addr_set(a, ua);
 143         return 0;
 144 }
 145
 146 /* tipc_udp_addr2msg - write an ip/udp address to a TIPC ndisc message */
 147 static int tipc_udp_addr2msg(char *msg, struct tipc_media_addr *a)
 148 {
 149         memset(msg, 0, TIPC_MEDIA_INFO_SIZE);
 150         msg[TIPC_MEDIA_TYPE_OFFSET] = TIPC_MEDIA_TYPE_UDP;
 151         memcpy(msg + TIPC_MEDIA_ADDR_OFFSET, a->value,
 152                sizeof(struct udp_media_addr));
 153         return 0;
 154 }
 155
 156 /* tipc_send_msg - enqueue a send request */
 157 static int tipc_udp_xmit(struct net *net, struct sk_buff *skb,
 158                          struct udp_bearer *ub, struct udp_media_addr *src,
 159                          struct udp_media_addr *dst)
 160 {
 161         int ttl, err = 0;
 162         struct rtable *rt;
 163
 164         if (dst->proto == htons(ETH_P_IP)) {
 165                 struct flowi4 fl = {
 166                         .daddr = dst->ipv4.s_addr,
 167                         .saddr = src->ipv4.s_addr,
 168                         .flowi4_mark = skb->mark,
 169                         .flowi4_proto = IPPROTO_UDP
 170                 };
 171                 rt = ip_route_output_key(net, &fl);
 172                 if (IS_ERR(rt)) {
 173                         err = PTR_ERR(rt);
 174                         goto tx_error;
 175                 }
 176
 177                 skb->dev = rt->dst.dev;
 178                 ttl = ip4_dst_hoplimit(&rt->dst);
 179                 udp_tunnel_xmit_skb(rt, ub->ubsock->sk, skb, src->ipv4.s_addr,
 180                                     dst->ipv4.s_addr, 0, ttl, 0, src->port,
 181                                     dst->port, false, true);
 182 #if IS_ENABLED(CONFIG_IPV6)
 183         } else {
 184                 struct dst_entry *ndst;
 185                 struct flowi6 fl6 = {
 186                         .flowi6_oif = ub->ifindex,
 187                         .daddr = dst->ipv6,
 188                         .saddr = src->ipv6,
 189                         .flowi6_proto = IPPROTO_UDP
 190                 };
 191                 err = ipv6_stub->ipv6_dst_lookup(net, ub->ubsock->sk, &ndst,
 192                                                  &fl6);
 193                 if (err)
 194                         goto tx_error;
 195                 ttl = ip6_dst_hoplimit(ndst);
 196                 err = udp_tunnel6_xmit_skb(ndst, ub->ubsock->sk, skb,
 197                                            ndst->dev, &src->ipv6,
 198                                            &dst->ipv6, 0, ttl, 0, src->port,
 199                                            dst->port, false);
 200 #endif
 201         }
 202         return err;
 203
 204 tx_error:
 205         kfree_skb(skb);
 206         return err;
 207 }
 208
 209 static int tipc_udp_send_msg(struct net *net, struct sk_buff *skb,
 210                              struct tipc_bearer *b,
 211                              struct tipc_media_addr *addr)
 212 {
 213         struct udp_media_addr *src = (struct udp_media_addr *)&b->addr.value;
 214         struct udp_media_addr *dst = (struct udp_media_addr *)&addr->value;
 215         struct udp_replicast *rcast;
 216         struct udp_bearer *ub;
 217         int err = 0;
 218
 219         if (skb_headroom(skb) < UDP_MIN_HEADROOM) {
 220                 err = pskb_expand_head(skb, UDP_MIN_HEADROOM, 0, GFP_ATOMIC);
 221                 if (err)
 222                         goto out;
 223         }
 224
 225         skb_set_inner_protocol(skb, htons(ETH_P_TIPC));
 226         ub = rcu_dereference_rtnl(b->media_ptr);
 227         if (!ub) {
 228                 err = -ENODEV;
 229                 goto out;
 230         }
 231
 232         if (addr->broadcast != TIPC_REPLICAST_SUPPORT)
 233                 return tipc_udp_xmit(net, skb, ub, src, dst);
 234
 235         /* Replicast, send an skb to each configured IP address */
 236         list_for_each_entry_rcu(rcast, &ub->rcast.list, list) {
 237                 struct sk_buff *_skb;
 238
 239                 _skb = pskb_copy(skb, GFP_ATOMIC);
 240                 if (!_skb) {
 241                         err = -ENOMEM;
 242                         goto out;
 243                 }
 244
 245                 err = tipc_udp_xmit(net, _skb, ub, src, &rcast->addr);
 246                 if (err) {
 247                         kfree_skb(_skb);
 248                         goto out;
 249                 }
 250         }
 251         err = 0;
 252 out:
 253         kfree_skb(skb);
 254         return err;
 255 }
 256
 257 static bool tipc_udp_is_known_peer(struct tipc_bearer *b,
 258                                    struct udp_media_addr *addr)
 259 {
 260         struct udp_replicast *rcast, *tmp;
 261         struct udp_bearer *ub;
 262
 263         ub = rcu_dereference_rtnl(b->media_ptr);
 264         if (!ub) {
 265                 pr_err_ratelimited("UDP bearer instance not found\n");
 266                 return false;
 267         }
 268
 269         list_for_each_entry_safe(rcast, tmp, &ub->rcast.list, list) {
 270                 if (!memcmp(&rcast->addr, addr, sizeof(struct udp_media_addr)))
 271                         return true;
 272         }
 273
 274         return false;
 275 }
 276
 277 static int tipc_udp_rcast_add(struct tipc_bearer *b,
 278                               struct udp_media_addr *addr)
 279 {
 280         struct udp_replicast *rcast;
 281         struct udp_bearer *ub;
 282
 283         ub = rcu_dereference_rtnl(b->media_ptr);
 284         if (!ub)
 285                 return -ENODEV;
 286
 287         rcast = kmalloc(sizeof(*rcast), GFP_ATOMIC);
 288         if (!rcast)
 289                 return -ENOMEM;
 290
 291         memcpy(&rcast->addr, addr, sizeof(struct udp_media_addr));
 292
 293         if (ntohs(addr->proto) == ETH_P_IP)
 294                 pr_info("New replicast peer: %pI4\n", &rcast->addr.ipv4);
 295 #if IS_ENABLED(CONFIG_IPV6)
 296         else if (ntohs(addr->proto) == ETH_P_IPV6)
 297                 pr_info("New replicast peer: %pI6\n", &rcast->addr.ipv6);
 298 #endif
 299         b->bcast_addr.broadcast = TIPC_REPLICAST_SUPPORT;
 300         list_add_rcu(&rcast->list, &ub->rcast.list);
 301         return 0;
 302 }
 303
 304 static int tipc_udp_rcast_disc(struct tipc_bearer *b, struct sk_buff *skb)
 305 {
 306         struct udp_media_addr src = {0};
 307         struct udp_media_addr *dst;
 308
 309         dst = (struct udp_media_addr *)&b->bcast_addr.value;
 310         if (tipc_udp_is_mcast_addr(dst))
 311                 return 0;
 312
 313         src.port = udp_hdr(skb)->source;
 314
 315         if (ip_hdr(skb)->version == 4) {
 316                 struct iphdr *iphdr = ip_hdr(skb);
 317
 318                 src.proto = htons(ETH_P_IP);
 319                 src.ipv4.s_addr = iphdr->saddr;
 320                 if (ipv4_is_multicast(iphdr->daddr))
 321                         return 0;
 322 #if IS_ENABLED(CONFIG_IPV6)
 323         } else if (ip_hdr(skb)->version == 6) {
 324                 struct ipv6hdr *iphdr = ipv6_hdr(skb);
 325
 326                 src.proto = htons(ETH_P_IPV6);
 327                 src.ipv6 = iphdr->saddr;
 328                 if (ipv6_addr_is_multicast(&iphdr->daddr))
 329                         return 0;
 330 #endif
 331         } else {
 332                 return 0;
 333         }
 334
 335         if (likely(tipc_udp_is_known_peer(b, &src)))
 336                 return 0;
 337
 338         return tipc_udp_rcast_add(b, &src);
 339 }
 340
 341 /* tipc_udp_recv - read data from bearer socket */
 342 static int tipc_udp_recv(struct sock *sk, struct sk_buff *skb)
 343 {
 344         struct udp_bearer *ub;
 345         struct tipc_bearer *b;
 346         struct tipc_msg *hdr;
 347         int err;
 348
 349         ub = rcu_dereference_sk_user_data(sk);
 350         if (!ub) {
 351                 pr_err_ratelimited("Failed to get UDP bearer reference");
 352                 goto out;
 353         }
 354         skb_pull(skb, sizeof(struct udphdr));
 355         hdr = buf_msg(skb);
 356
 357         rcu_read_lock();
 358         b = rcu_dereference_rtnl(ub->bearer);
 359         if (!b)
 360                 goto rcu_out;
 361
 362         if (b && test_bit(0, &b->up)) {
 363                 tipc_rcv(sock_net(sk), skb, b);
 364                 rcu_read_unlock();
 365                 return 0;
 366         }
 367
 368         if (unlikely(msg_user(hdr) == LINK_CONFIG)) {
 369                 err = tipc_udp_rcast_disc(b, skb);
 370                 if (err)
 371                         goto rcu_out;
 372         }
 373
 374 rcu_out:
 375         rcu_read_unlock();
 376 out:
 377         kfree_skb(skb);
 378         return 0;
 379 }
 380
 381 static int enable_mcast(struct udp_bearer *ub, struct udp_media_addr *remote)
 382 {
 383         int err = 0;
 384         struct ip_mreqn mreqn;
 385         struct sock *sk = ub->ubsock->sk;
 386
 387         if (ntohs(remote->proto) == ETH_P_IP) {
 388                 mreqn.imr_multiaddr = remote->ipv4;
 389                 mreqn.imr_ifindex = ub->ifindex;
 390                 err = ip_mc_join_group(sk, &mreqn);
 391 #if IS_ENABLED(CONFIG_IPV6)
 392         } else {
 393                 err = ipv6_stub->ipv6_sock_mc_join(sk, ub->ifindex,
 394                                                    &remote->ipv6);
 395 #endif
 396         }
 397         return err;
 398 }
 399
 400 static int __tipc_nl_add_udp_addr(struct sk_buff *skb,
 401                                   struct udp_media_addr *addr, int nla_t)
 402 {
 403         if (ntohs(addr->proto) == ETH_P_IP) {
 404                 struct sockaddr_in ip4;
 405
 406                 memset(&ip4, 0, sizeof(ip4));
 407                 ip4.sin_family = AF_INET;
 408                 ip4.sin_port = addr->port;
 409                 ip4.sin_addr.s_addr = addr->ipv4.s_addr;
 410                 if (nla_put(skb, nla_t, sizeof(ip4), &ip4))
 411                         return -EMSGSIZE;
 412
 413 #if IS_ENABLED(CONFIG_IPV6)
 414         } else if (ntohs(addr->proto) == ETH_P_IPV6) {
 415                 struct sockaddr_in6 ip6;
 416
 417                 memset(&ip6, 0, sizeof(ip6));
 418                 ip6.sin6_family = AF_INET6;
 419                 ip6.sin6_port  = addr->port;
 420                 memcpy(&ip6.sin6_addr, &addr->ipv6, sizeof(struct in6_addr));
 421                 if (nla_put(skb, nla_t, sizeof(ip6), &ip6))
 422                         return -EMSGSIZE;
 423 #endif
 424         }
 425
 426         return 0;
 427 }
 428
 429 int tipc_udp_nl_dump_remoteip(struct sk_buff *skb, struct netlink_callback *cb)
 430 {
 431         u32 bid = cb->args[0];
 432         u32 skip_cnt = cb->args[1];
 433         u32 portid = NETLINK_CB(cb->skb).portid;
 434         struct udp_replicast *rcast, *tmp;
 435         struct tipc_bearer *b;
 436         struct udp_bearer *ub;
 437         void *hdr;
 438         int err;
 439         int i;
 440
 441         if (!bid && !skip_cnt) {
 442                 struct net *net = sock_net(skb->sk);
 443                 struct nlattr *battrs[TIPC_NLA_BEARER_MAX + 1];
 444                 struct nlattr **attrs;
 445                 char *bname;
 446
 447                 err = tipc_nlmsg_parse(cb->nlh, &attrs);
 448                 if (err)
 449                         return err;
 450
 451                 if (!attrs[TIPC_NLA_BEARER])
 452                         return -EINVAL;
 453
 454                 err = nla_parse_nested(battrs, TIPC_NLA_BEARER_MAX,
 455                                        attrs[TIPC_NLA_BEARER],
 456                                        tipc_nl_bearer_policy, NULL);
 457                 if (err)
 458                         return err;
 459
 460                 if (!battrs[TIPC_NLA_BEARER_NAME])
 461                         return -EINVAL;
 462
 463                 bname = nla_data(battrs[TIPC_NLA_BEARER_NAME]);
 464
 465                 rtnl_lock();
 466                 b = tipc_bearer_find(net, bname);
 467                 if (!b) {
 468                         rtnl_unlock();
 469                         return -EINVAL;
 470                 }
 471                 bid = b->identity;
 472         } else {
 473                 struct net *net = sock_net(skb->sk);
 474                 struct tipc_net *tn = net_generic(net, tipc_net_id);
 475
 476                 rtnl_lock();
 477                 b = rtnl_dereference(tn->bearer_list[bid]);
 478                 if (!b) {
 479                         rtnl_unlock();
 480                         return -EINVAL;
 481                 }
 482         }
 483
 484         ub = rcu_dereference_rtnl(b->media_ptr);
 485         if (!ub) {
 486                 rtnl_unlock();
 487                 return -EINVAL;
 488         }
 489
 490         i = 0;
 491         list_for_each_entry_safe(rcast, tmp, &ub->rcast.list, list) {
 492                 if (i < skip_cnt)
 493                         goto count;
 494
 495                 hdr = genlmsg_put(skb, portid, cb->nlh->nlmsg_seq,
 496                                   &tipc_genl_family, NLM_F_MULTI,
 497                                   TIPC_NL_BEARER_GET);
 498                 if (!hdr)
 499                         goto done;
 500
 501                 err = __tipc_nl_add_udp_addr(skb, &rcast->addr,
 502                                              TIPC_NLA_UDP_REMOTE);
 503                 if (err) {
 504                         genlmsg_cancel(skb, hdr);
 505                         goto done;
 506                 }
 507                 genlmsg_end(skb, hdr);
 508 count:
 509                 i++;
 510         }
 511 done:
 512         rtnl_unlock();
 513         cb->args[0] = bid;
 514         cb->args[1] = i;
 515
 516         return skb->len;
 517 }
 518
 519 int tipc_udp_nl_add_bearer_data(struct tipc_nl_msg *msg, struct tipc_bearer *b)
 520 {
 521         struct udp_media_addr *src = (struct udp_media_addr *)&b->addr.value;
 522         struct udp_media_addr *dst;
 523         struct udp_bearer *ub;
 524         struct nlattr *nest;
 525
 526         ub = rcu_dereference_rtnl(b->media_ptr);
 527         if (!ub)
 528                 return -ENODEV;
 529
 530         nest = nla_nest_start(msg->skb, TIPC_NLA_BEARER_UDP_OPTS);
 531         if (!nest)
 532                 goto msg_full;
 533
 534         if (__tipc_nl_add_udp_addr(msg->skb, src, TIPC_NLA_UDP_LOCAL))
 535                 goto msg_full;
 536
 537         dst = (struct udp_media_addr *)&b->bcast_addr.value;
 538         if (__tipc_nl_add_udp_addr(msg->skb, dst, TIPC_NLA_UDP_REMOTE))
 539                 goto msg_full;
 540
 541         if (!list_empty(&ub->rcast.list)) {
 542                 if (nla_put_flag(msg->skb, TIPC_NLA_UDP_MULTI_REMOTEIP))
 543                         goto msg_full;
 544         }
 545
 546         nla_nest_end(msg->skb, nest);
 547         return 0;
 548 msg_full:
 549         nla_nest_cancel(msg->skb, nest);
 550         return -EMSGSIZE;
 551 }
 552
 553 /**
 554  * tipc_parse_udp_addr - build udp media address from netlink data
 555  * @nlattr:     netlink attribute containing sockaddr storage aligned address
 556  * @addr:       tipc media address to fill with address, port and protocol type
 557  * @scope_id:   IPv6 scope id pointer, not NULL indicates it's required
 558  */
 559
 560 static int tipc_parse_udp_addr(struct nlattr *nla, struct udp_media_addr *addr,
 561                                u32 *scope_id)
 562 {
 563         struct sockaddr_storage sa;
 564
 565         nla_memcpy(&sa, nla, sizeof(sa));
 566         if (sa.ss_family == AF_INET) {
 567                 struct sockaddr_in *ip4 = (struct sockaddr_in *)&sa;
 568
 569                 addr->proto = htons(ETH_P_IP);
 570                 addr->port = ip4->sin_port;
 571                 addr->ipv4.s_addr = ip4->sin_addr.s_addr;
 572                 return 0;
 573
 574 #if IS_ENABLED(CONFIG_IPV6)
 575         } else if (sa.ss_family == AF_INET6) {
 576                 struct sockaddr_in6 *ip6 = (struct sockaddr_in6 *)&sa;
 577
 578                 addr->proto = htons(ETH_P_IPV6);
 579                 addr->port = ip6->sin6_port;
 580                 memcpy(&addr->ipv6, &ip6->sin6_addr, sizeof(struct in6_addr));
 581
 582                 /* Scope ID is only interesting for local addresses */
 583                 if (scope_id) {
 584                         int atype;
 585
 586                         atype = ipv6_addr_type(&ip6->sin6_addr);
 587                         if (__ipv6_addr_needs_scope_id(atype) &&
 588                             !ip6->sin6_scope_id) {
 589                                 return -EINVAL;
 590                         }
 591
 592                         *scope_id = ip6->sin6_scope_id ? : 0;
 593                 }
 594
 595                 return 0;
 596 #endif
 597         }
 598         return -EADDRNOTAVAIL;
 599 }
 600
 601 int tipc_udp_nl_bearer_add(struct tipc_bearer *b, struct nlattr *attr)
 602 {
 603         int err;
 604         struct udp_media_addr addr = {0};
 605         struct nlattr *opts[TIPC_NLA_UDP_MAX + 1];
 606         struct udp_media_addr *dst;
 607
 608         if (nla_parse_nested(opts, TIPC_NLA_UDP_MAX, attr,
 609                              tipc_nl_udp_policy, NULL))
 610                 return -EINVAL;
 611
 612         if (!opts[TIPC_NLA_UDP_REMOTE])
 613                 return -EINVAL;
 614
 615         err = tipc_parse_udp_addr(opts[TIPC_NLA_UDP_REMOTE], &addr, NULL);
 616         if (err)
 617                 return err;
 618
 619         dst = (struct udp_media_addr *)&b->bcast_addr.value;
 620         if (tipc_udp_is_mcast_addr(dst)) {
 621                 pr_err("Can't add remote ip to TIPC UDP multicast bearer\n");
 622                 return -EINVAL;
 623         }
 624
 625         if (tipc_udp_is_known_peer(b, &addr))
 626                 return 0;
 627
 628         return tipc_udp_rcast_add(b, &addr);
 629 }
 630
 631 /**
 632  * tipc_udp_enable - callback to create a new udp bearer instance
 633  * @net:        network namespace
 634  * @b:          pointer to generic tipc_bearer
 635  * @attrs:      netlink bearer configuration
 636  *
 637  * validate the bearer parameters and initialize the udp bearer
 638  * rtnl_lock should be held
 639  */
 640 static int tipc_udp_enable(struct net *net, struct tipc_bearer *b,
 641                            struct nlattr *attrs[])
 642 {
 643         int err = -EINVAL;
 644         struct udp_bearer *ub;
 645         struct udp_media_addr remote = {0};
 646         struct udp_media_addr local = {0};
 647         struct udp_port_cfg udp_conf = {0};
 648         struct udp_tunnel_sock_cfg tuncfg = {NULL};
 649         struct nlattr *opts[TIPC_NLA_UDP_MAX + 1];
 650
 651         ub = kzalloc(sizeof(*ub), GFP_ATOMIC);
 652         if (!ub)
 653                 return -ENOMEM;
 654
 655         INIT_LIST_HEAD(&ub->rcast.list);
 656
 657         if (!attrs[TIPC_NLA_BEARER_UDP_OPTS])
 658                 goto err;
 659
 660         if (nla_parse_nested(opts, TIPC_NLA_UDP_MAX,
 661                              attrs[TIPC_NLA_BEARER_UDP_OPTS],
 662                              tipc_nl_udp_policy, NULL))
 663                 goto err;
 664
 665         if (!opts[TIPC_NLA_UDP_LOCAL] || !opts[TIPC_NLA_UDP_REMOTE]) {
 666                 pr_err("Invalid UDP bearer configuration");
 667                 err = -EINVAL;
 668                 goto err;
 669         }
 670
 671         err = tipc_parse_udp_addr(opts[TIPC_NLA_UDP_LOCAL], &local,
 672                                   &ub->ifindex);
 673         if (err)
 674                 goto err;
 675
 676         err = tipc_parse_udp_addr(opts[TIPC_NLA_UDP_REMOTE], &remote, NULL);
 677         if (err)
 678                 goto err;
 679
 680         b->bcast_addr.media_id = TIPC_MEDIA_TYPE_UDP;
 681         b->bcast_addr.broadcast = TIPC_BROADCAST_SUPPORT;
 682         rcu_assign_pointer(b->media_ptr, ub);
 683         rcu_assign_pointer(ub->bearer, b);
 684         tipc_udp_media_addr_set(&b->addr, &local);
 685         if (local.proto == htons(ETH_P_IP)) {
 686                 struct net_device *dev;
 687
 688                 dev = __ip_dev_find(net, local.ipv4.s_addr, false);
 689                 if (!dev) {
 690                         err = -ENODEV;
 691                         goto err;
 692                 }
 693                 udp_conf.family = AF_INET;
 694                 udp_conf.local_ip.s_addr = htonl(INADDR_ANY);
 695                 udp_conf.use_udp_checksums = false;
 696                 ub->ifindex = dev->ifindex;
 697                 if (tipc_mtu_bad(dev, sizeof(struct iphdr) +
 698                                       sizeof(struct udphdr))) {
 699                         err = -EINVAL;
 700                         goto err;
 701                 }
 702                 b->mtu = dev->mtu - sizeof(struct iphdr)
 703                         - sizeof(struct udphdr);
 704 #if IS_ENABLED(CONFIG_IPV6)
 705         } else if (local.proto == htons(ETH_P_IPV6)) {
 706                 udp_conf.family = AF_INET6;
 707                 udp_conf.use_udp6_tx_checksums = true;
 708                 udp_conf.use_udp6_rx_checksums = true;
 709                 udp_conf.local_ip6 = in6addr_any;
 710                 b->mtu = 1280;
 711 #endif
 712         } else {
 713                 err = -EAFNOSUPPORT;
 714                 goto err;
 715         }
 716         udp_conf.local_udp_port = local.port;
 717         err = udp_sock_create(net, &udp_conf, &ub->ubsock);
 718         if (err)
 719                 goto err;
 720         tuncfg.sk_user_data = ub;
 721         tuncfg.encap_type = 1;
 722         tuncfg.encap_rcv = tipc_udp_recv;
 723         tuncfg.encap_destroy = NULL;
 724         setup_udp_tunnel_sock(net, ub->ubsock, &tuncfg);
 725
 726         /**
 727          * The bcast media address port is used for all peers and the ip
 728          * is used if it's a multicast address.
 729          */
 730         memcpy(&b->bcast_addr.value, &remote, sizeof(remote));
 731         if (tipc_udp_is_mcast_addr(&remote))
 732                 err = enable_mcast(ub, &remote);
 733         else
 734                 err = tipc_udp_rcast_add(b, &remote);
 735         if (err)
 736                 goto err;
 737
 738         return 0;
 739 err:
 740         if (ub->ubsock)
 741                 udp_tunnel_sock_release(ub->ubsock);
 742         kfree(ub);
 743         return err;
 744 }
 745
 746 /* cleanup_bearer - break the socket/bearer association */
 747 static void cleanup_bearer(struct work_struct *work)
 748 {
 749         struct udp_bearer *ub = container_of(work, struct udp_bearer, work);
 750         struct udp_replicast *rcast, *tmp;
 751
 752         list_for_each_entry_safe(rcast, tmp, &ub->rcast.list, list) {
 753                 list_del_rcu(&rcast->list);
 754                 kfree_rcu(rcast, rcu);
 755         }
 756
 757         if (ub->ubsock)
 758                 udp_tunnel_sock_release(ub->ubsock);
 759         synchronize_net();
 760         kfree(ub);
 761 }
 762
 763 /* tipc_udp_disable - detach bearer from socket */
 764 static void tipc_udp_disable(struct tipc_bearer *b)
 765 {
 766         struct udp_bearer *ub;
 767
 768         ub = rcu_dereference_rtnl(b->media_ptr);
 769         if (!ub) {
 770                 pr_err("UDP bearer instance not found\n");
 771                 return;
 772         }
 773         if (ub->ubsock)
 774                 sock_set_flag(ub->ubsock->sk, SOCK_DEAD);
 775         RCU_INIT_POINTER(ub->bearer, NULL);
 776
 777         /* sock_release need to be done outside of rtnl lock */
 778         INIT_WORK(&ub->work, cleanup_bearer);
 779         schedule_work(&ub->work);
 780 }
 781
 782 struct tipc_media udp_media_info = {
 783         .send_msg       = tipc_udp_send_msg,
 784         .enable_media   = tipc_udp_enable,
 785         .disable_media  = tipc_udp_disable,
 786         .addr2str       = tipc_udp_addr2str,
 787         .addr2msg       = tipc_udp_addr2msg,
 788         .msg2addr       = tipc_udp_msg2addr,
 789         .priority       = TIPC_DEF_LINK_PRI,
 790         .tolerance      = TIPC_DEF_LINK_TOL,
 791         .window         = TIPC_DEF_LINK_WIN,
 792         .type_id        = TIPC_MEDIA_TYPE_UDP,
 793         .hwaddr_len     = 0,
 794         .name           = "udp"
 795 };