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                 ttl = ip4_dst_hoplimit(&rt->dst);
 178                 udp_tunnel_xmit_skb(rt, ub->ubsock->sk, skb, src->ipv4.s_addr,
 179                                     dst->ipv4.s_addr, 0, ttl, 0, src->port,
 180                                     dst->port, false, true);
 181 #if IS_ENABLED(CONFIG_IPV6)
 182         } else {
 183                 struct dst_entry *ndst;
 184                 struct flowi6 fl6 = {
 185                         .flowi6_oif = ub->ifindex,
 186                         .daddr = dst->ipv6,
 187                         .saddr = src->ipv6,
 188                         .flowi6_proto = IPPROTO_UDP
 189                 };
 190                 err = ipv6_stub->ipv6_dst_lookup(net, ub->ubsock->sk, &ndst,
 191                                                  &fl6);
 192                 if (err)
 193                         goto tx_error;
 194                 ttl = ip6_dst_hoplimit(ndst);
 195                 err = udp_tunnel6_xmit_skb(ndst, ub->ubsock->sk, skb, NULL,
 196                                            &src->ipv6, &dst->ipv6, 0, ttl, 0,
 197                                            src->port, dst->port, false);
 198 #endif
 199         }
 200         return err;
 201
 202 tx_error:
 203         kfree_skb(skb);
 204         return err;
 205 }
 206
 207 static int tipc_udp_send_msg(struct net *net, struct sk_buff *skb,
 208                              struct tipc_bearer *b,
 209                              struct tipc_media_addr *addr)
 210 {
 211         struct udp_media_addr *src = (struct udp_media_addr *)&b->addr.value;
 212         struct udp_media_addr *dst = (struct udp_media_addr *)&addr->value;
 213         struct udp_replicast *rcast;
 214         struct udp_bearer *ub;
 215         int err = 0;
 216
 217         if (skb_headroom(skb) < UDP_MIN_HEADROOM) {
 218                 err = pskb_expand_head(skb, UDP_MIN_HEADROOM, 0, GFP_ATOMIC);
 219                 if (err)
 220                         goto out;
 221         }
 222
 223         skb_set_inner_protocol(skb, htons(ETH_P_TIPC));
 224         ub = rcu_dereference_rtnl(b->media_ptr);
 225         if (!ub) {
 226                 err = -ENODEV;
 227                 goto out;
 228         }
 229
 230         if (addr->broadcast != TIPC_REPLICAST_SUPPORT)
 231                 return tipc_udp_xmit(net, skb, ub, src, dst);
 232
 233         /* Replicast, send an skb to each configured IP address */
 234         list_for_each_entry_rcu(rcast, &ub->rcast.list, list) {
 235                 struct sk_buff *_skb;
 236
 237                 _skb = pskb_copy(skb, GFP_ATOMIC);
 238                 if (!_skb) {
 239                         err = -ENOMEM;
 240                         goto out;
 241                 }
 242
 243                 err = tipc_udp_xmit(net, _skb, ub, src, &rcast->addr);
 244                 if (err)
 245                         goto out;
 246         }
 247         err = 0;
 248 out:
 249         kfree_skb(skb);
 250         return err;
 251 }
 252
 253 static bool tipc_udp_is_known_peer(struct tipc_bearer *b,
 254                                    struct udp_media_addr *addr)
 255 {
 256         struct udp_replicast *rcast, *tmp;
 257         struct udp_bearer *ub;
 258
 259         ub = rcu_dereference_rtnl(b->media_ptr);
 260         if (!ub) {
 261                 pr_err_ratelimited("UDP bearer instance not found\n");
 262                 return false;
 263         }
 264
 265         list_for_each_entry_safe(rcast, tmp, &ub->rcast.list, list) {
 266                 if (!memcmp(&rcast->addr, addr, sizeof(struct udp_media_addr)))
 267                         return true;
 268         }
 269
 270         return false;
 271 }
 272
 273 static int tipc_udp_rcast_add(struct tipc_bearer *b,
 274                               struct udp_media_addr *addr)
 275 {
 276         struct udp_replicast *rcast;
 277         struct udp_bearer *ub;
 278
 279         ub = rcu_dereference_rtnl(b->media_ptr);
 280         if (!ub)
 281                 return -ENODEV;
 282
 283         rcast = kmalloc(sizeof(*rcast), GFP_ATOMIC);
 284         if (!rcast)
 285                 return -ENOMEM;
 286
 287         memcpy(&rcast->addr, addr, sizeof(struct udp_media_addr));
 288
 289         if (ntohs(addr->proto) == ETH_P_IP)
 290                 pr_info("New replicast peer: %pI4\n", &rcast->addr.ipv4);
 291 #if IS_ENABLED(CONFIG_IPV6)
 292         else if (ntohs(addr->proto) == ETH_P_IPV6)
 293                 pr_info("New replicast peer: %pI6\n", &rcast->addr.ipv6);
 294 #endif
 295         b->bcast_addr.broadcast = TIPC_REPLICAST_SUPPORT;
 296         list_add_rcu(&rcast->list, &ub->rcast.list);
 297         return 0;
 298 }
 299
 300 static int tipc_udp_rcast_disc(struct tipc_bearer *b, struct sk_buff *skb)
 301 {
 302         struct udp_media_addr src = {0};
 303         struct udp_media_addr *dst;
 304
 305         dst = (struct udp_media_addr *)&b->bcast_addr.value;
 306         if (tipc_udp_is_mcast_addr(dst))
 307                 return 0;
 308
 309         src.port = udp_hdr(skb)->source;
 310
 311         if (ip_hdr(skb)->version == 4) {
 312                 struct iphdr *iphdr = ip_hdr(skb);
 313
 314                 src.proto = htons(ETH_P_IP);
 315                 src.ipv4.s_addr = iphdr->saddr;
 316                 if (ipv4_is_multicast(iphdr->daddr))
 317                         return 0;
 318 #if IS_ENABLED(CONFIG_IPV6)
 319         } else if (ip_hdr(skb)->version == 6) {
 320                 struct ipv6hdr *iphdr = ipv6_hdr(skb);
 321
 322                 src.proto = htons(ETH_P_IPV6);
 323                 src.ipv6 = iphdr->saddr;
 324                 if (ipv6_addr_is_multicast(&iphdr->daddr))
 325                         return 0;
 326 #endif
 327         } else {
 328                 return 0;
 329         }
 330
 331         if (likely(tipc_udp_is_known_peer(b, &src)))
 332                 return 0;
 333
 334         return tipc_udp_rcast_add(b, &src);
 335 }
 336
 337 /* tipc_udp_recv - read data from bearer socket */
 338 static int tipc_udp_recv(struct sock *sk, struct sk_buff *skb)
 339 {
 340         struct udp_bearer *ub;
 341         struct tipc_bearer *b;
 342         struct tipc_msg *hdr;
 343         int err;
 344
 345         ub = rcu_dereference_sk_user_data(sk);
 346         if (!ub) {
 347                 pr_err_ratelimited("Failed to get UDP bearer reference");
 348                 goto out;
 349         }
 350         skb_pull(skb, sizeof(struct udphdr));
 351         hdr = buf_msg(skb);
 352
 353         rcu_read_lock();
 354         b = rcu_dereference_rtnl(ub->bearer);
 355         if (!b)
 356                 goto rcu_out;
 357
 358         if (b && test_bit(0, &b->up)) {
 359                 tipc_rcv(sock_net(sk), skb, b);
 360                 rcu_read_unlock();
 361                 return 0;
 362         }
 363
 364         if (unlikely(msg_user(hdr) == LINK_CONFIG)) {
 365                 err = tipc_udp_rcast_disc(b, skb);
 366                 if (err)
 367                         goto rcu_out;
 368         }
 369
 370 rcu_out:
 371         rcu_read_unlock();
 372 out:
 373         kfree_skb(skb);
 374         return 0;
 375 }
 376
 377 static int enable_mcast(struct udp_bearer *ub, struct udp_media_addr *remote)
 378 {
 379         int err = 0;
 380         struct ip_mreqn mreqn;
 381         struct sock *sk = ub->ubsock->sk;
 382
 383         if (ntohs(remote->proto) == ETH_P_IP) {
 384                 mreqn.imr_multiaddr = remote->ipv4;
 385                 mreqn.imr_ifindex = ub->ifindex;
 386                 err = ip_mc_join_group(sk, &mreqn);
 387 #if IS_ENABLED(CONFIG_IPV6)
 388         } else {
 389                 err = ipv6_stub->ipv6_sock_mc_join(sk, ub->ifindex,
 390                                                    &remote->ipv6);
 391 #endif
 392         }
 393         return err;
 394 }
 395
 396 static int __tipc_nl_add_udp_addr(struct sk_buff *skb,
 397                                   struct udp_media_addr *addr, int nla_t)
 398 {
 399         if (ntohs(addr->proto) == ETH_P_IP) {
 400                 struct sockaddr_in ip4;
 401
 402                 memset(&ip4, 0, sizeof(ip4));
 403                 ip4.sin_family = AF_INET;
 404                 ip4.sin_port = addr->port;
 405                 ip4.sin_addr.s_addr = addr->ipv4.s_addr;
 406                 if (nla_put(skb, nla_t, sizeof(ip4), &ip4))
 407                         return -EMSGSIZE;
 408
 409 #if IS_ENABLED(CONFIG_IPV6)
 410         } else if (ntohs(addr->proto) == ETH_P_IPV6) {
 411                 struct sockaddr_in6 ip6;
 412
 413                 memset(&ip6, 0, sizeof(ip6));
 414                 ip6.sin6_family = AF_INET6;
 415                 ip6.sin6_port  = addr->port;
 416                 memcpy(&ip6.sin6_addr, &addr->ipv6, sizeof(struct in6_addr));
 417                 if (nla_put(skb, nla_t, sizeof(ip6), &ip6))
 418                         return -EMSGSIZE;
 419 #endif
 420         }
 421
 422         return 0;
 423 }
 424
 425 int tipc_udp_nl_dump_remoteip(struct sk_buff *skb, struct netlink_callback *cb)
 426 {
 427         u32 bid = cb->args[0];
 428         u32 skip_cnt = cb->args[1];
 429         u32 portid = NETLINK_CB(cb->skb).portid;
 430         struct udp_replicast *rcast, *tmp;
 431         struct tipc_bearer *b;
 432         struct udp_bearer *ub;
 433         void *hdr;
 434         int err;
 435         int i;
 436
 437         if (!bid && !skip_cnt) {
 438                 struct net *net = sock_net(skb->sk);
 439                 struct nlattr *battrs[TIPC_NLA_BEARER_MAX + 1];
 440                 struct nlattr **attrs;
 441                 char *bname;
 442
 443                 err = tipc_nlmsg_parse(cb->nlh, &attrs);
 444                 if (err)
 445                         return err;
 446
 447                 if (!attrs[TIPC_NLA_BEARER])
 448                         return -EINVAL;
 449
 450                 err = nla_parse_nested(battrs, TIPC_NLA_BEARER_MAX,
 451                                        attrs[TIPC_NLA_BEARER],
 452                                        tipc_nl_bearer_policy, NULL);
 453                 if (err)
 454                         return err;
 455
 456                 if (!battrs[TIPC_NLA_BEARER_NAME])
 457                         return -EINVAL;
 458
 459                 bname = nla_data(battrs[TIPC_NLA_BEARER_NAME]);
 460
 461                 rtnl_lock();
 462                 b = tipc_bearer_find(net, bname);
 463                 if (!b) {
 464                         rtnl_unlock();
 465                         return -EINVAL;
 466                 }
 467                 bid = b->identity;
 468         } else {
 469                 struct net *net = sock_net(skb->sk);
 470                 struct tipc_net *tn = net_generic(net, tipc_net_id);
 471
 472                 rtnl_lock();
 473                 b = rtnl_dereference(tn->bearer_list[bid]);
 474                 if (!b) {
 475                         rtnl_unlock();
 476                         return -EINVAL;
 477                 }
 478         }
 479
 480         ub = rcu_dereference_rtnl(b->media_ptr);
 481         if (!ub) {
 482                 rtnl_unlock();
 483                 return -EINVAL;
 484         }
 485
 486         i = 0;
 487         list_for_each_entry_safe(rcast, tmp, &ub->rcast.list, list) {
 488                 if (i < skip_cnt)
 489                         goto count;
 490
 491                 hdr = genlmsg_put(skb, portid, cb->nlh->nlmsg_seq,
 492                                   &tipc_genl_family, NLM_F_MULTI,
 493                                   TIPC_NL_BEARER_GET);
 494                 if (!hdr)
 495                         goto done;
 496
 497                 err = __tipc_nl_add_udp_addr(skb, &rcast->addr,
 498                                              TIPC_NLA_UDP_REMOTE);
 499                 if (err) {
 500                         genlmsg_cancel(skb, hdr);
 501                         goto done;
 502                 }
 503                 genlmsg_end(skb, hdr);
 504 count:
 505                 i++;
 506         }
 507 done:
 508         rtnl_unlock();
 509         cb->args[0] = bid;
 510         cb->args[1] = i;
 511
 512         return skb->len;
 513 }
 514
 515 int tipc_udp_nl_add_bearer_data(struct tipc_nl_msg *msg, struct tipc_bearer *b)
 516 {
 517         struct udp_media_addr *src = (struct udp_media_addr *)&b->addr.value;
 518         struct udp_media_addr *dst;
 519         struct udp_bearer *ub;
 520         struct nlattr *nest;
 521
 522         ub = rcu_dereference_rtnl(b->media_ptr);
 523         if (!ub)
 524                 return -ENODEV;
 525
 526         nest = nla_nest_start(msg->skb, TIPC_NLA_BEARER_UDP_OPTS);
 527         if (!nest)
 528                 goto msg_full;
 529
 530         if (__tipc_nl_add_udp_addr(msg->skb, src, TIPC_NLA_UDP_LOCAL))
 531                 goto msg_full;
 532
 533         dst = (struct udp_media_addr *)&b->bcast_addr.value;
 534         if (__tipc_nl_add_udp_addr(msg->skb, dst, TIPC_NLA_UDP_REMOTE))
 535                 goto msg_full;
 536
 537         if (!list_empty(&ub->rcast.list)) {
 538                 if (nla_put_flag(msg->skb, TIPC_NLA_UDP_MULTI_REMOTEIP))
 539                         goto msg_full;
 540         }
 541
 542         nla_nest_end(msg->skb, nest);
 543         return 0;
 544 msg_full:
 545         nla_nest_cancel(msg->skb, nest);
 546         return -EMSGSIZE;
 547 }
 548
 549 /**
 550  * tipc_parse_udp_addr - build udp media address from netlink data
 551  * @nlattr:     netlink attribute containing sockaddr storage aligned address
 552  * @addr:       tipc media address to fill with address, port and protocol type
 553  * @scope_id:   IPv6 scope id pointer, not NULL indicates it's required
 554  */
 555
 556 static int tipc_parse_udp_addr(struct nlattr *nla, struct udp_media_addr *addr,
 557                                u32 *scope_id)
 558 {
 559         struct sockaddr_storage sa;
 560
 561         nla_memcpy(&sa, nla, sizeof(sa));
 562         if (sa.ss_family == AF_INET) {
 563                 struct sockaddr_in *ip4 = (struct sockaddr_in *)&sa;
 564
 565                 addr->proto = htons(ETH_P_IP);
 566                 addr->port = ip4->sin_port;
 567                 addr->ipv4.s_addr = ip4->sin_addr.s_addr;
 568                 return 0;
 569
 570 #if IS_ENABLED(CONFIG_IPV6)
 571         } else if (sa.ss_family == AF_INET6) {
 572                 struct sockaddr_in6 *ip6 = (struct sockaddr_in6 *)&sa;
 573
 574                 addr->proto = htons(ETH_P_IPV6);
 575                 addr->port = ip6->sin6_port;
 576                 memcpy(&addr->ipv6, &ip6->sin6_addr, sizeof(struct in6_addr));
 577
 578                 /* Scope ID is only interesting for local addresses */
 579                 if (scope_id) {
 580                         int atype;
 581
 582                         atype = ipv6_addr_type(&ip6->sin6_addr);
 583                         if (__ipv6_addr_needs_scope_id(atype) &&
 584                             !ip6->sin6_scope_id) {
 585                                 return -EINVAL;
 586                         }
 587
 588                         *scope_id = ip6->sin6_scope_id ? : 0;
 589                 }
 590
 591                 return 0;
 592 #endif
 593         }
 594         return -EADDRNOTAVAIL;
 595 }
 596
 597 int tipc_udp_nl_bearer_add(struct tipc_bearer *b, struct nlattr *attr)
 598 {
 599         int err;
 600         struct udp_media_addr addr = {0};
 601         struct nlattr *opts[TIPC_NLA_UDP_MAX + 1];
 602         struct udp_media_addr *dst;
 603
 604         if (nla_parse_nested(opts, TIPC_NLA_UDP_MAX, attr,
 605                              tipc_nl_udp_policy, NULL))
 606                 return -EINVAL;
 607
 608         if (!opts[TIPC_NLA_UDP_REMOTE])
 609                 return -EINVAL;
 610
 611         err = tipc_parse_udp_addr(opts[TIPC_NLA_UDP_REMOTE], &addr, NULL);
 612         if (err)
 613                 return err;
 614
 615         dst = (struct udp_media_addr *)&b->bcast_addr.value;
 616         if (tipc_udp_is_mcast_addr(dst)) {
 617                 pr_err("Can't add remote ip to TIPC UDP multicast bearer\n");
 618                 return -EINVAL;
 619         }
 620
 621         if (tipc_udp_is_known_peer(b, &addr))
 622                 return 0;
 623
 624         return tipc_udp_rcast_add(b, &addr);
 625 }
 626
 627 /**
 628  * tipc_udp_enable - callback to create a new udp bearer instance
 629  * @net:        network namespace
 630  * @b:          pointer to generic tipc_bearer
 631  * @attrs:      netlink bearer configuration
 632  *
 633  * validate the bearer parameters and initialize the udp bearer
 634  * rtnl_lock should be held
 635  */
 636 static int tipc_udp_enable(struct net *net, struct tipc_bearer *b,
 637                            struct nlattr *attrs[])
 638 {
 639         int err = -EINVAL;
 640         struct udp_bearer *ub;
 641         struct udp_media_addr remote = {0};
 642         struct udp_media_addr local = {0};
 643         struct udp_port_cfg udp_conf = {0};
 644         struct udp_tunnel_sock_cfg tuncfg = {NULL};
 645         struct nlattr *opts[TIPC_NLA_UDP_MAX + 1];
 646
 647         ub = kzalloc(sizeof(*ub), GFP_ATOMIC);
 648         if (!ub)
 649                 return -ENOMEM;
 650
 651         INIT_LIST_HEAD(&ub->rcast.list);
 652
 653         if (!attrs[TIPC_NLA_BEARER_UDP_OPTS])
 654                 goto err;
 655
 656         if (nla_parse_nested(opts, TIPC_NLA_UDP_MAX,
 657                              attrs[TIPC_NLA_BEARER_UDP_OPTS],
 658                              tipc_nl_udp_policy, NULL))
 659                 goto err;
 660
 661         if (!opts[TIPC_NLA_UDP_LOCAL] || !opts[TIPC_NLA_UDP_REMOTE]) {
 662                 pr_err("Invalid UDP bearer configuration");
 663                 err = -EINVAL;
 664                 goto err;
 665         }
 666
 667         err = tipc_parse_udp_addr(opts[TIPC_NLA_UDP_LOCAL], &local,
 668                                   &ub->ifindex);
 669         if (err)
 670                 goto err;
 671
 672         err = tipc_parse_udp_addr(opts[TIPC_NLA_UDP_REMOTE], &remote, NULL);
 673         if (err)
 674                 goto err;
 675
 676         if (remote.proto != local.proto) {
 677                 err = -EINVAL;
 678                 goto err;
 679         }
 680
 681         b->bcast_addr.media_id = TIPC_MEDIA_TYPE_UDP;
 682         b->bcast_addr.broadcast = TIPC_BROADCAST_SUPPORT;
 683         rcu_assign_pointer(b->media_ptr, ub);
 684         rcu_assign_pointer(ub->bearer, b);
 685         tipc_udp_media_addr_set(&b->addr, &local);
 686         if (local.proto == htons(ETH_P_IP)) {
 687                 struct net_device *dev;
 688
 689                 dev = __ip_dev_find(net, local.ipv4.s_addr, false);
 690                 if (!dev) {
 691                         err = -ENODEV;
 692                         goto err;
 693                 }
 694                 udp_conf.family = AF_INET;
 695                 udp_conf.local_ip.s_addr = htonl(INADDR_ANY);
 696                 udp_conf.use_udp_checksums = false;
 697                 ub->ifindex = dev->ifindex;
 698                 if (tipc_mtu_bad(dev, sizeof(struct iphdr) +
 699                                       sizeof(struct udphdr))) {
 700                         err = -EINVAL;
 701                         goto err;
 702                 }
 703                 b->mtu = dev->mtu - sizeof(struct iphdr)
 704                         - sizeof(struct udphdr);
 705 #if IS_ENABLED(CONFIG_IPV6)
 706         } else if (local.proto == htons(ETH_P_IPV6)) {
 707                 udp_conf.family = AF_INET6;
 708                 udp_conf.use_udp6_tx_checksums = true;
 709                 udp_conf.use_udp6_rx_checksums = true;
 710                 udp_conf.local_ip6 = in6addr_any;
 711                 b->mtu = 1280;
 712 #endif
 713         } else {
 714                 err = -EAFNOSUPPORT;
 715                 goto err;
 716         }
 717         udp_conf.local_udp_port = local.port;
 718         err = udp_sock_create(net, &udp_conf, &ub->ubsock);
 719         if (err)
 720                 goto err;
 721         tuncfg.sk_user_data = ub;
 722         tuncfg.encap_type = 1;
 723         tuncfg.encap_rcv = tipc_udp_recv;
 724         tuncfg.encap_destroy = NULL;
 725         setup_udp_tunnel_sock(net, ub->ubsock, &tuncfg);
 726
 727         /**
 728          * The bcast media address port is used for all peers and the ip
 729          * is used if it's a multicast address.
 730          */
 731         memcpy(&b->bcast_addr.value, &remote, sizeof(remote));
 732         if (tipc_udp_is_mcast_addr(&remote))
 733                 err = enable_mcast(ub, &remote);
 734         else
 735                 err = tipc_udp_rcast_add(b, &remote);
 736         if (err)
 737                 goto err;
 738
 739         return 0;
 740 err:
 741         if (ub->ubsock)
 742                 udp_tunnel_sock_release(ub->ubsock);
 743         kfree(ub);
 744         return err;
 745 }
 746
 747 /* cleanup_bearer - break the socket/bearer association */
 748 static void cleanup_bearer(struct work_struct *work)
 749 {
 750         struct udp_bearer *ub = container_of(work, struct udp_bearer, work);
 751         struct udp_replicast *rcast, *tmp;
 752
 753         list_for_each_entry_safe(rcast, tmp, &ub->rcast.list, list) {
 754                 list_del_rcu(&rcast->list);
 755                 kfree_rcu(rcast, rcu);
 756         }
 757
 758         if (ub->ubsock)
 759                 udp_tunnel_sock_release(ub->ubsock);
 760         synchronize_net();
 761         kfree(ub);
 762 }
 763
 764 /* tipc_udp_disable - detach bearer from socket */
 765 static void tipc_udp_disable(struct tipc_bearer *b)
 766 {
 767         struct udp_bearer *ub;
 768
 769         ub = rcu_dereference_rtnl(b->media_ptr);
 770         if (!ub) {
 771                 pr_err("UDP bearer instance not found\n");
 772                 return;
 773         }
 774         if (ub->ubsock)
 775                 sock_set_flag(ub->ubsock->sk, SOCK_DEAD);
 776         RCU_INIT_POINTER(ub->bearer, NULL);
 777
 778         /* sock_release need to be done outside of rtnl lock */
 779         INIT_WORK(&ub->work, cleanup_bearer);
 780         schedule_work(&ub->work);
 781 }
 782
 783 struct tipc_media udp_media_info = {
 784         .send_msg       = tipc_udp_send_msg,
 785         .enable_media   = tipc_udp_enable,
 786         .disable_media  = tipc_udp_disable,
 787         .addr2str       = tipc_udp_addr2str,
 788         .addr2msg       = tipc_udp_addr2msg,
 789         .msg2addr       = tipc_udp_msg2addr,
 790         .priority       = TIPC_DEF_LINK_PRI,
 791         .tolerance      = TIPC_DEF_LINK_TOL,
 792         .window         = TIPC_DEF_LINK_WIN,
 793         .type_id        = TIPC_MEDIA_TYPE_UDP,
 794         .hwaddr_len     = 0,
 795         .name           = "udp"
 796 };