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 = 1;
 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 || list_empty(&ub->rcast.list))
 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
 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         tipc_rcv(sock_net(sk), skb, b);
 375         rcu_read_unlock();
 376         return 0;
 377
 378 rcu_out:
 379         rcu_read_unlock();
 380 out:
 381         kfree_skb(skb);
 382         return 0;
 383 }
 384
 385 static int enable_mcast(struct udp_bearer *ub, struct udp_media_addr *remote)
 386 {
 387         int err = 0;
 388         struct ip_mreqn mreqn;
 389         struct sock *sk = ub->ubsock->sk;
 390
 391         if (ntohs(remote->proto) == ETH_P_IP) {
 392                 mreqn.imr_multiaddr = remote->ipv4;
 393                 mreqn.imr_ifindex = ub->ifindex;
 394                 err = ip_mc_join_group(sk, &mreqn);
 395 #if IS_ENABLED(CONFIG_IPV6)
 396         } else {
 397                 err = ipv6_stub->ipv6_sock_mc_join(sk, ub->ifindex,
 398                                                    &remote->ipv6);
 399 #endif
 400         }
 401         return err;
 402 }
 403
 404 static int __tipc_nl_add_udp_addr(struct sk_buff *skb,
 405                                   struct udp_media_addr *addr, int nla_t)
 406 {
 407         if (ntohs(addr->proto) == ETH_P_IP) {
 408                 struct sockaddr_in ip4;
 409
 410                 memset(&ip4, 0, sizeof(ip4));
 411                 ip4.sin_family = AF_INET;
 412                 ip4.sin_port = addr->port;
 413                 ip4.sin_addr.s_addr = addr->ipv4.s_addr;
 414                 if (nla_put(skb, nla_t, sizeof(ip4), &ip4))
 415                         return -EMSGSIZE;
 416
 417 #if IS_ENABLED(CONFIG_IPV6)
 418         } else if (ntohs(addr->proto) == ETH_P_IPV6) {
 419                 struct sockaddr_in6 ip6;
 420
 421                 memset(&ip6, 0, sizeof(ip6));
 422                 ip6.sin6_family = AF_INET6;
 423                 ip6.sin6_port  = addr->port;
 424                 memcpy(&ip6.sin6_addr, &addr->ipv6, sizeof(struct in6_addr));
 425                 if (nla_put(skb, nla_t, sizeof(ip6), &ip6))
 426                         return -EMSGSIZE;
 427 #endif
 428         }
 429
 430         return 0;
 431 }
 432
 433 int tipc_udp_nl_dump_remoteip(struct sk_buff *skb, struct netlink_callback *cb)
 434 {
 435         u32 bid = cb->args[0];
 436         u32 skip_cnt = cb->args[1];
 437         u32 portid = NETLINK_CB(cb->skb).portid;
 438         struct udp_replicast *rcast, *tmp;
 439         struct tipc_bearer *b;
 440         struct udp_bearer *ub;
 441         void *hdr;
 442         int err;
 443         int i;
 444
 445         if (!bid && !skip_cnt) {
 446                 struct net *net = sock_net(skb->sk);
 447                 struct nlattr *battrs[TIPC_NLA_BEARER_MAX + 1];
 448                 struct nlattr **attrs;
 449                 char *bname;
 450
 451                 err = tipc_nlmsg_parse(cb->nlh, &attrs);
 452                 if (err)
 453                         return err;
 454
 455                 if (!attrs[TIPC_NLA_BEARER])
 456                         return -EINVAL;
 457
 458                 err = nla_parse_nested(battrs, TIPC_NLA_BEARER_MAX,
 459                                        attrs[TIPC_NLA_BEARER],
 460                                        tipc_nl_bearer_policy);
 461                 if (err)
 462                         return err;
 463
 464                 if (!battrs[TIPC_NLA_BEARER_NAME])
 465                         return -EINVAL;
 466
 467                 bname = nla_data(battrs[TIPC_NLA_BEARER_NAME]);
 468
 469                 rtnl_lock();
 470                 b = tipc_bearer_find(net, bname);
 471                 if (!b) {
 472                         rtnl_unlock();
 473                         return -EINVAL;
 474                 }
 475                 bid = b->identity;
 476         } else {
 477                 struct net *net = sock_net(skb->sk);
 478                 struct tipc_net *tn = net_generic(net, tipc_net_id);
 479
 480                 rtnl_lock();
 481                 b = rtnl_dereference(tn->bearer_list[bid]);
 482                 if (!b) {
 483                         rtnl_unlock();
 484                         return -EINVAL;
 485                 }
 486         }
 487
 488         ub = rcu_dereference_rtnl(b->media_ptr);
 489         if (!ub) {
 490                 rtnl_unlock();
 491                 return -EINVAL;
 492         }
 493
 494         i = 0;
 495         list_for_each_entry_safe(rcast, tmp, &ub->rcast.list, list) {
 496                 if (i < skip_cnt)
 497                         goto count;
 498
 499                 hdr = genlmsg_put(skb, portid, cb->nlh->nlmsg_seq,
 500                                   &tipc_genl_family, NLM_F_MULTI,
 501                                   TIPC_NL_BEARER_GET);
 502                 if (!hdr)
 503                         goto done;
 504
 505                 err = __tipc_nl_add_udp_addr(skb, &rcast->addr,
 506                                              TIPC_NLA_UDP_REMOTE);
 507                 if (err) {
 508                         genlmsg_cancel(skb, hdr);
 509                         goto done;
 510                 }
 511                 genlmsg_end(skb, hdr);
 512 count:
 513                 i++;
 514         }
 515 done:
 516         rtnl_unlock();
 517         cb->args[0] = bid;
 518         cb->args[1] = i;
 519
 520         return skb->len;
 521 }
 522
 523 int tipc_udp_nl_add_bearer_data(struct tipc_nl_msg *msg, struct tipc_bearer *b)
 524 {
 525         struct udp_media_addr *src = (struct udp_media_addr *)&b->addr.value;
 526         struct udp_media_addr *dst;
 527         struct udp_bearer *ub;
 528         struct nlattr *nest;
 529
 530         ub = rcu_dereference_rtnl(b->media_ptr);
 531         if (!ub)
 532                 return -ENODEV;
 533
 534         nest = nla_nest_start(msg->skb, TIPC_NLA_BEARER_UDP_OPTS);
 535         if (!nest)
 536                 goto msg_full;
 537
 538         if (__tipc_nl_add_udp_addr(msg->skb, src, TIPC_NLA_UDP_LOCAL))
 539                 goto msg_full;
 540
 541         dst = (struct udp_media_addr *)&b->bcast_addr.value;
 542         if (__tipc_nl_add_udp_addr(msg->skb, dst, TIPC_NLA_UDP_REMOTE))
 543                 goto msg_full;
 544
 545         if (!list_empty(&ub->rcast.list)) {
 546                 if (nla_put_flag(msg->skb, TIPC_NLA_UDP_MULTI_REMOTEIP))
 547                         goto msg_full;
 548         }
 549
 550         nla_nest_end(msg->skb, nest);
 551         return 0;
 552 msg_full:
 553         nla_nest_cancel(msg->skb, nest);
 554         return -EMSGSIZE;
 555 }
 556
 557 /**
 558  * tipc_parse_udp_addr - build udp media address from netlink data
 559  * @nlattr:     netlink attribute containing sockaddr storage aligned address
 560  * @addr:       tipc media address to fill with address, port and protocol type
 561  * @scope_id:   IPv6 scope id pointer, not NULL indicates it's required
 562  */
 563
 564 static int tipc_parse_udp_addr(struct nlattr *nla, struct udp_media_addr *addr,
 565                                u32 *scope_id)
 566 {
 567         struct sockaddr_storage sa;
 568
 569         nla_memcpy(&sa, nla, sizeof(sa));
 570         if (sa.ss_family == AF_INET) {
 571                 struct sockaddr_in *ip4 = (struct sockaddr_in *)&sa;
 572
 573                 addr->proto = htons(ETH_P_IP);
 574                 addr->port = ip4->sin_port;
 575                 addr->ipv4.s_addr = ip4->sin_addr.s_addr;
 576                 return 0;
 577
 578 #if IS_ENABLED(CONFIG_IPV6)
 579         } else if (sa.ss_family == AF_INET6) {
 580                 struct sockaddr_in6 *ip6 = (struct sockaddr_in6 *)&sa;
 581
 582                 addr->proto = htons(ETH_P_IPV6);
 583                 addr->port = ip6->sin6_port;
 584                 memcpy(&addr->ipv6, &ip6->sin6_addr, sizeof(struct in6_addr));
 585
 586                 /* Scope ID is only interesting for local addresses */
 587                 if (scope_id) {
 588                         int atype;
 589
 590                         atype = ipv6_addr_type(&ip6->sin6_addr);
 591                         if (__ipv6_addr_needs_scope_id(atype) &&
 592                             !ip6->sin6_scope_id) {
 593                                 return -EINVAL;
 594                         }
 595
 596                         *scope_id = ip6->sin6_scope_id ? : 0;
 597                 }
 598
 599                 return 0;
 600 #endif
 601         }
 602         return -EADDRNOTAVAIL;
 603 }
 604
 605 int tipc_udp_nl_bearer_add(struct tipc_bearer *b, struct nlattr *attr)
 606 {
 607         int err;
 608         struct udp_media_addr addr = {0};
 609         struct nlattr *opts[TIPC_NLA_UDP_MAX + 1];
 610         struct udp_media_addr *dst;
 611
 612         if (nla_parse_nested(opts, TIPC_NLA_UDP_MAX, attr, tipc_nl_udp_policy))
 613                 return -EINVAL;
 614
 615         if (!opts[TIPC_NLA_UDP_REMOTE])
 616                 return -EINVAL;
 617
 618         err = tipc_parse_udp_addr(opts[TIPC_NLA_UDP_REMOTE], &addr, NULL);
 619         if (err)
 620                 return err;
 621
 622         dst = (struct udp_media_addr *)&b->bcast_addr.value;
 623         if (tipc_udp_is_mcast_addr(dst)) {
 624                 pr_err("Can't add remote ip to TIPC UDP multicast bearer\n");
 625                 return -EINVAL;
 626         }
 627
 628         if (tipc_udp_is_known_peer(b, &addr))
 629                 return 0;
 630
 631         return tipc_udp_rcast_add(b, &addr);
 632 }
 633
 634 /**
 635  * tipc_udp_enable - callback to create a new udp bearer instance
 636  * @net:        network namespace
 637  * @b:          pointer to generic tipc_bearer
 638  * @attrs:      netlink bearer configuration
 639  *
 640  * validate the bearer parameters and initialize the udp bearer
 641  * rtnl_lock should be held
 642  */
 643 static int tipc_udp_enable(struct net *net, struct tipc_bearer *b,
 644                            struct nlattr *attrs[])
 645 {
 646         int err = -EINVAL;
 647         struct udp_bearer *ub;
 648         struct udp_media_addr remote = {0};
 649         struct udp_media_addr local = {0};
 650         struct udp_port_cfg udp_conf = {0};
 651         struct udp_tunnel_sock_cfg tuncfg = {NULL};
 652         struct nlattr *opts[TIPC_NLA_UDP_MAX + 1];
 653
 654         ub = kzalloc(sizeof(*ub), GFP_ATOMIC);
 655         if (!ub)
 656                 return -ENOMEM;
 657
 658         INIT_LIST_HEAD(&ub->rcast.list);
 659
 660         if (!attrs[TIPC_NLA_BEARER_UDP_OPTS])
 661                 goto err;
 662
 663         if (nla_parse_nested(opts, TIPC_NLA_UDP_MAX,
 664                              attrs[TIPC_NLA_BEARER_UDP_OPTS],
 665                              tipc_nl_udp_policy))
 666                 goto err;
 667
 668         if (!opts[TIPC_NLA_UDP_LOCAL] || !opts[TIPC_NLA_UDP_REMOTE]) {
 669                 pr_err("Invalid UDP bearer configuration");
 670                 err = -EINVAL;
 671                 goto err;
 672         }
 673
 674         err = tipc_parse_udp_addr(opts[TIPC_NLA_UDP_LOCAL], &local,
 675                                   &ub->ifindex);
 676         if (err)
 677                 goto err;
 678
 679         err = tipc_parse_udp_addr(opts[TIPC_NLA_UDP_REMOTE], &remote, NULL);
 680         if (err)
 681                 goto err;
 682
 683         b->bcast_addr.media_id = TIPC_MEDIA_TYPE_UDP;
 684         b->bcast_addr.broadcast = 1;
 685         rcu_assign_pointer(b->media_ptr, ub);
 686         rcu_assign_pointer(ub->bearer, b);
 687         tipc_udp_media_addr_set(&b->addr, &local);
 688         if (local.proto == htons(ETH_P_IP)) {
 689                 struct net_device *dev;
 690
 691                 dev = __ip_dev_find(net, local.ipv4.s_addr, false);
 692                 if (!dev) {
 693                         err = -ENODEV;
 694                         goto err;
 695                 }
 696                 udp_conf.family = AF_INET;
 697                 udp_conf.local_ip.s_addr = htonl(INADDR_ANY);
 698                 udp_conf.use_udp_checksums = false;
 699                 ub->ifindex = dev->ifindex;
 700                 if (tipc_mtu_bad(dev, sizeof(struct iphdr) +
 701                                       sizeof(struct udphdr))) {
 702                         err = -EINVAL;
 703                         goto err;
 704                 }
 705                 b->mtu = dev->mtu - sizeof(struct iphdr)
 706                         - sizeof(struct udphdr);
 707 #if IS_ENABLED(CONFIG_IPV6)
 708         } else if (local.proto == htons(ETH_P_IPV6)) {
 709                 udp_conf.family = AF_INET6;
 710                 udp_conf.use_udp6_tx_checksums = true;
 711                 udp_conf.use_udp6_rx_checksums = true;
 712                 udp_conf.local_ip6 = in6addr_any;
 713                 b->mtu = 1280;
 714 #endif
 715         } else {
 716                 err = -EAFNOSUPPORT;
 717                 goto err;
 718         }
 719         udp_conf.local_udp_port = local.port;
 720         err = udp_sock_create(net, &udp_conf, &ub->ubsock);
 721         if (err)
 722                 goto err;
 723         tuncfg.sk_user_data = ub;
 724         tuncfg.encap_type = 1;
 725         tuncfg.encap_rcv = tipc_udp_recv;
 726         tuncfg.encap_destroy = NULL;
 727         setup_udp_tunnel_sock(net, ub->ubsock, &tuncfg);
 728
 729         /**
 730          * The bcast media address port is used for all peers and the ip
 731          * is used if it's a multicast address.
 732          */
 733         memcpy(&b->bcast_addr.value, &remote, sizeof(remote));
 734         if (tipc_udp_is_mcast_addr(&remote))
 735                 err = enable_mcast(ub, &remote);
 736         else
 737                 err = tipc_udp_rcast_add(b, &remote);
 738         if (err)
 739                 goto err;
 740
 741         return 0;
 742 err:
 743         if (ub->ubsock)
 744                 udp_tunnel_sock_release(ub->ubsock);
 745         kfree(ub);
 746         return err;
 747 }
 748
 749 /* cleanup_bearer - break the socket/bearer association */
 750 static void cleanup_bearer(struct work_struct *work)
 751 {
 752         struct udp_bearer *ub = container_of(work, struct udp_bearer, work);
 753         struct udp_replicast *rcast, *tmp;
 754
 755         list_for_each_entry_safe(rcast, tmp, &ub->rcast.list, list) {
 756                 list_del_rcu(&rcast->list);
 757                 kfree_rcu(rcast, rcu);
 758         }
 759
 760         if (ub->ubsock)
 761                 udp_tunnel_sock_release(ub->ubsock);
 762         synchronize_net();
 763         kfree(ub);
 764 }
 765
 766 /* tipc_udp_disable - detach bearer from socket */
 767 static void tipc_udp_disable(struct tipc_bearer *b)
 768 {
 769         struct udp_bearer *ub;
 770
 771         ub = rcu_dereference_rtnl(b->media_ptr);
 772         if (!ub) {
 773                 pr_err("UDP bearer instance not found\n");
 774                 return;
 775         }
 776         if (ub->ubsock)
 777                 sock_set_flag(ub->ubsock->sk, SOCK_DEAD);
 778         RCU_INIT_POINTER(ub->bearer, NULL);
 779
 780         /* sock_release need to be done outside of rtnl lock */
 781         INIT_WORK(&ub->work, cleanup_bearer);
 782         schedule_work(&ub->work);
 783 }
 784
 785 struct tipc_media udp_media_info = {
 786         .send_msg       = tipc_udp_send_msg,
 787         .enable_media   = tipc_udp_enable,
 788         .disable_media  = tipc_udp_disable,
 789         .addr2str       = tipc_udp_addr2str,
 790         .addr2msg       = tipc_udp_addr2msg,
 791         .msg2addr       = tipc_udp_msg2addr,
 792         .priority       = TIPC_DEF_LINK_PRI,
 793         .tolerance      = TIPC_DEF_LINK_TOL,
 794         .window         = TIPC_DEF_LINK_WIN,
 795         .type_id        = TIPC_MEDIA_TYPE_UDP,
 796         .hwaddr_len     = 0,
 797         .name           = "udp"
 798 };