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 "msg.h"
  52
  53 /* IANA assigned UDP port */
  54 #define UDP_PORT_DEFAULT        6118
  55
  56 #define UDP_MIN_HEADROOM        28
  57
  58 static const struct nla_policy tipc_nl_udp_policy[TIPC_NLA_UDP_MAX + 1] = {
  59         [TIPC_NLA_UDP_UNSPEC]   = {.type = NLA_UNSPEC},
  60         [TIPC_NLA_UDP_LOCAL]    = {.type = NLA_BINARY,
  61                                    .len = sizeof(struct sockaddr_storage)},
  62         [TIPC_NLA_UDP_REMOTE]   = {.type = NLA_BINARY,
  63                                    .len = sizeof(struct sockaddr_storage)},
  64 };
  65
  66 /**
  67  * struct udp_media_addr - IP/UDP addressing information
  68  *
  69  * This is the bearer level originating address used in neighbor discovery
  70  * messages, and all fields should be in network byte order
  71  */
  72 struct udp_media_addr {
  73         __be16  proto;
  74         __be16  udp_port;
  75         union {
  76                 struct in_addr ipv4;
  77                 struct in6_addr ipv6;
  78         };
  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 };
  94
  95 /* udp_media_addr_set - convert a ip/udp address to a TIPC media address */
  96 static void tipc_udp_media_addr_set(struct tipc_media_addr *addr,
  97                                     struct udp_media_addr *ua)
  98 {
  99         memset(addr, 0, sizeof(struct tipc_media_addr));
 100         addr->media_id = TIPC_MEDIA_TYPE_UDP;
 101         memcpy(addr->value, ua, sizeof(struct udp_media_addr));
 102         if (ntohs(ua->proto) == ETH_P_IP) {
 103                 if (ipv4_is_multicast(ua->ipv4.s_addr))
 104                         addr->broadcast = 1;
 105         } else if (ntohs(ua->proto) == ETH_P_IPV6) {
 106                 if (ipv6_addr_type(&ua->ipv6) & IPV6_ADDR_MULTICAST)
 107                         addr->broadcast = 1;
 108         } else {
 109                 pr_err("Invalid UDP media address\n");
 110         }
 111 }
 112
 113 /* tipc_udp_addr2str - convert ip/udp address to string */
 114 static int tipc_udp_addr2str(struct tipc_media_addr *a, char *buf, int size)
 115 {
 116         struct udp_media_addr *ua = (struct udp_media_addr *)&a->value;
 117
 118         if (ntohs(ua->proto) == ETH_P_IP)
 119                 snprintf(buf, size, "%pI4:%u", &ua->ipv4, ntohs(ua->udp_port));
 120         else if (ntohs(ua->proto) == ETH_P_IPV6)
 121                 snprintf(buf, size, "%pI6:%u", &ua->ipv6, ntohs(ua->udp_port));
 122         else
 123                 pr_err("Invalid UDP media address\n");
 124         return 0;
 125 }
 126
 127 /* tipc_udp_msg2addr - extract an ip/udp address from a TIPC ndisc message */
 128 static int tipc_udp_msg2addr(struct tipc_bearer *b, struct tipc_media_addr *a,
 129                              char *msg)
 130 {
 131         struct udp_media_addr *ua;
 132
 133         ua = (struct udp_media_addr *) (msg + TIPC_MEDIA_ADDR_OFFSET);
 134         if (msg[TIPC_MEDIA_TYPE_OFFSET] != TIPC_MEDIA_TYPE_UDP)
 135                 return -EINVAL;
 136         tipc_udp_media_addr_set(a, ua);
 137         return 0;
 138 }
 139
 140 /* tipc_udp_addr2msg - write an ip/udp address to a TIPC ndisc message */
 141 static int tipc_udp_addr2msg(char *msg, struct tipc_media_addr *a)
 142 {
 143         memset(msg, 0, TIPC_MEDIA_INFO_SIZE);
 144         msg[TIPC_MEDIA_TYPE_OFFSET] = TIPC_MEDIA_TYPE_UDP;
 145         memcpy(msg + TIPC_MEDIA_ADDR_OFFSET, a->value,
 146                sizeof(struct udp_media_addr));
 147         return 0;
 148 }
 149
 150 /* tipc_send_msg - enqueue a send request */
 151 static int tipc_udp_send_msg(struct net *net, struct sk_buff *skb,
 152                              struct tipc_bearer *b,
 153                              struct tipc_media_addr *dest)
 154 {
 155         int ttl, err = 0;
 156         struct udp_bearer *ub;
 157         struct udp_media_addr *dst = (struct udp_media_addr *)&dest->value;
 158         struct udp_media_addr *src = (struct udp_media_addr *)&b->addr.value;
 159         struct sk_buff *clone;
 160         struct rtable *rt;
 161
 162         if (skb_headroom(skb) < UDP_MIN_HEADROOM)
 163                 pskb_expand_head(skb, UDP_MIN_HEADROOM, 0, GFP_ATOMIC);
 164
 165         clone = skb_clone(skb, GFP_ATOMIC);
 166         skb_set_inner_protocol(clone, htons(ETH_P_TIPC));
 167         ub = rcu_dereference_rtnl(b->media_ptr);
 168         if (!ub) {
 169                 err = -ENODEV;
 170                 goto tx_error;
 171         }
 172         if (dst->proto == htons(ETH_P_IP)) {
 173                 struct flowi4 fl = {
 174                         .daddr = dst->ipv4.s_addr,
 175                         .saddr = src->ipv4.s_addr,
 176                         .flowi4_mark = clone->mark,
 177                         .flowi4_proto = IPPROTO_UDP
 178                 };
 179                 rt = ip_route_output_key(net, &fl);
 180                 if (IS_ERR(rt)) {
 181                         err = PTR_ERR(rt);
 182                         goto tx_error;
 183                 }
 184                 ttl = ip4_dst_hoplimit(&rt->dst);
 185                 err = udp_tunnel_xmit_skb(rt, ub->ubsock->sk, clone,
 186                                           src->ipv4.s_addr,
 187                                           dst->ipv4.s_addr, 0, ttl, 0,
 188                                           src->udp_port, dst->udp_port,
 189                                           false, true);
 190                 if (err < 0) {
 191                         ip_rt_put(rt);
 192                         goto tx_error;
 193                 }
 194 #if IS_ENABLED(CONFIG_IPV6)
 195         } else {
 196                 struct dst_entry *ndst;
 197                 struct flowi6 fl6 = {
 198                         .flowi6_oif = ub->ifindex,
 199                         .daddr = dst->ipv6,
 200                         .saddr = src->ipv6,
 201                         .flowi6_proto = IPPROTO_UDP
 202                 };
 203                 err = ipv6_stub->ipv6_dst_lookup(net, ub->ubsock->sk, &ndst,
 204                                                  &fl6);
 205                 if (err)
 206                         goto tx_error;
 207                 ttl = ip6_dst_hoplimit(ndst);
 208                 err = udp_tunnel6_xmit_skb(ndst, ub->ubsock->sk, clone,
 209                                            ndst->dev, &src->ipv6,
 210                                            &dst->ipv6, 0, ttl, src->udp_port,
 211                                            dst->udp_port, false);
 212 #endif
 213         }
 214         return err;
 215
 216 tx_error:
 217         kfree_skb(clone);
 218         return err;
 219 }
 220
 221 /* tipc_udp_recv - read data from bearer socket */
 222 static int tipc_udp_recv(struct sock *sk, struct sk_buff *skb)
 223 {
 224         struct udp_bearer *ub;
 225         struct tipc_bearer *b;
 226         int usr = msg_user(buf_msg(skb));
 227
 228         if ((usr == LINK_PROTOCOL) || (usr == NAME_DISTRIBUTOR))
 229                 skb_linearize(skb);
 230
 231         ub = rcu_dereference_sk_user_data(sk);
 232         if (!ub) {
 233                 pr_err_ratelimited("Failed to get UDP bearer reference");
 234                 kfree_skb(skb);
 235                 return 0;
 236         }
 237
 238         skb_pull(skb, sizeof(struct udphdr));
 239         rcu_read_lock();
 240         b = rcu_dereference_rtnl(ub->bearer);
 241
 242         if (b) {
 243                 tipc_rcv(sock_net(sk), skb, b);
 244                 rcu_read_unlock();
 245                 return 0;
 246         }
 247         rcu_read_unlock();
 248         kfree_skb(skb);
 249         return 0;
 250 }
 251
 252 static int enable_mcast(struct udp_bearer *ub, struct udp_media_addr *remote)
 253 {
 254         int err = 0;
 255         struct ip_mreqn mreqn;
 256         struct sock *sk = ub->ubsock->sk;
 257
 258         if (ntohs(remote->proto) == ETH_P_IP) {
 259                 if (!ipv4_is_multicast(remote->ipv4.s_addr))
 260                         return 0;
 261                 mreqn.imr_multiaddr = remote->ipv4;
 262                 mreqn.imr_ifindex = ub->ifindex;
 263                 err = ip_mc_join_group(sk, &mreqn);
 264 #if IS_ENABLED(CONFIG_IPV6)
 265         } else {
 266                 if (!ipv6_addr_is_multicast(&remote->ipv6))
 267                         return 0;
 268                 err = ipv6_stub->ipv6_sock_mc_join(sk, ub->ifindex,
 269                                                    &remote->ipv6);
 270 #endif
 271         }
 272         return err;
 273 }
 274
 275 /**
 276  * parse_options - build local/remote addresses from configuration
 277  * @attrs:      netlink config data
 278  * @ub:         UDP bearer instance
 279  * @local:      local bearer IP address/port
 280  * @remote:     peer or multicast IP/port
 281  */
 282 static int parse_options(struct nlattr *attrs[], struct udp_bearer *ub,
 283                          struct udp_media_addr *local,
 284                          struct udp_media_addr *remote)
 285 {
 286         struct nlattr *opts[TIPC_NLA_UDP_MAX + 1];
 287         struct sockaddr_storage *sa_local, *sa_remote;
 288
 289         if (!attrs[TIPC_NLA_BEARER_UDP_OPTS])
 290                 goto err;
 291         if (nla_parse_nested(opts, TIPC_NLA_UDP_MAX,
 292                              attrs[TIPC_NLA_BEARER_UDP_OPTS],
 293                              tipc_nl_udp_policy))
 294                 goto err;
 295         if (opts[TIPC_NLA_UDP_LOCAL] && opts[TIPC_NLA_UDP_REMOTE]) {
 296                 sa_local = nla_data(opts[TIPC_NLA_UDP_LOCAL]);
 297                 sa_remote = nla_data(opts[TIPC_NLA_UDP_REMOTE]);
 298         } else {
 299 err:
 300                 pr_err("Invalid UDP bearer configuration");
 301                 return -EINVAL;
 302         }
 303         if ((sa_local->ss_family & sa_remote->ss_family) == AF_INET) {
 304                 struct sockaddr_in *ip4;
 305
 306                 ip4 = (struct sockaddr_in *)sa_local;
 307                 local->proto = htons(ETH_P_IP);
 308                 local->udp_port = ip4->sin_port;
 309                 local->ipv4.s_addr = ip4->sin_addr.s_addr;
 310
 311                 ip4 = (struct sockaddr_in *)sa_remote;
 312                 remote->proto = htons(ETH_P_IP);
 313                 remote->udp_port = ip4->sin_port;
 314                 remote->ipv4.s_addr = ip4->sin_addr.s_addr;
 315                 return 0;
 316
 317 #if IS_ENABLED(CONFIG_IPV6)
 318         } else if ((sa_local->ss_family & sa_remote->ss_family) == AF_INET6) {
 319                 struct sockaddr_in6 *ip6;
 320
 321                 ip6 = (struct sockaddr_in6 *)sa_local;
 322                 local->proto = htons(ETH_P_IPV6);
 323                 local->udp_port = ip6->sin6_port;
 324                 local->ipv6 = ip6->sin6_addr;
 325                 ub->ifindex = ip6->sin6_scope_id;
 326
 327                 ip6 = (struct sockaddr_in6 *)sa_remote;
 328                 remote->proto = htons(ETH_P_IPV6);
 329                 remote->udp_port = ip6->sin6_port;
 330                 remote->ipv6 = ip6->sin6_addr;
 331                 return 0;
 332 #endif
 333         }
 334         return -EADDRNOTAVAIL;
 335 }
 336
 337 /**
 338  * tipc_udp_enable - callback to create a new udp bearer instance
 339  * @net:        network namespace
 340  * @b:          pointer to generic tipc_bearer
 341  * @attrs:      netlink bearer configuration
 342  *
 343  * validate the bearer parameters and initialize the udp bearer
 344  * rtnl_lock should be held
 345  */
 346 static int tipc_udp_enable(struct net *net, struct tipc_bearer *b,
 347                            struct nlattr *attrs[])
 348 {
 349         int err = -EINVAL;
 350         struct udp_bearer *ub;
 351         struct udp_media_addr *remote;
 352         struct udp_media_addr local = {0};
 353         struct udp_port_cfg udp_conf = {0};
 354         struct udp_tunnel_sock_cfg tuncfg = {NULL};
 355
 356         ub = kzalloc(sizeof(*ub), GFP_ATOMIC);
 357         if (!ub)
 358                 return -ENOMEM;
 359
 360         remote = (struct udp_media_addr *)&b->bcast_addr.value;
 361         memset(remote, 0, sizeof(struct udp_media_addr));
 362         err = parse_options(attrs, ub, &local, remote);
 363         if (err)
 364                 goto err;
 365
 366         b->bcast_addr.media_id = TIPC_MEDIA_TYPE_UDP;
 367         b->bcast_addr.broadcast = 1;
 368         rcu_assign_pointer(b->media_ptr, ub);
 369         rcu_assign_pointer(ub->bearer, b);
 370         tipc_udp_media_addr_set(&b->addr, &local);
 371         if (local.proto == htons(ETH_P_IP)) {
 372                 struct net_device *dev;
 373
 374                 dev = __ip_dev_find(net, local.ipv4.s_addr, false);
 375                 if (!dev) {
 376                         err = -ENODEV;
 377                         goto err;
 378                 }
 379                 udp_conf.family = AF_INET;
 380                 udp_conf.local_ip.s_addr = htonl(INADDR_ANY);
 381                 udp_conf.use_udp_checksums = false;
 382                 ub->ifindex = dev->ifindex;
 383                 b->mtu = dev->mtu - sizeof(struct iphdr)
 384                         - sizeof(struct udphdr);
 385 #if IS_ENABLED(CONFIG_IPV6)
 386         } else if (local.proto == htons(ETH_P_IPV6)) {
 387                 udp_conf.family = AF_INET6;
 388                 udp_conf.use_udp6_tx_checksums = true;
 389                 udp_conf.use_udp6_rx_checksums = true;
 390                 udp_conf.local_ip6 = in6addr_any;
 391                 b->mtu = 1280;
 392 #endif
 393         } else {
 394                 err = -EAFNOSUPPORT;
 395                 goto err;
 396         }
 397         udp_conf.local_udp_port = local.udp_port;
 398         err = udp_sock_create(net, &udp_conf, &ub->ubsock);
 399         if (err)
 400                 goto err;
 401         tuncfg.sk_user_data = ub;
 402         tuncfg.encap_type = 1;
 403         tuncfg.encap_rcv = tipc_udp_recv;
 404         tuncfg.encap_destroy = NULL;
 405         setup_udp_tunnel_sock(net, ub->ubsock, &tuncfg);
 406
 407         if (enable_mcast(ub, remote))
 408                 goto err;
 409         return 0;
 410 err:
 411         kfree(ub);
 412         return err;
 413 }
 414
 415 /* cleanup_bearer - break the socket/bearer association */
 416 static void cleanup_bearer(struct work_struct *work)
 417 {
 418         struct udp_bearer *ub = container_of(work, struct udp_bearer, work);
 419
 420         if (ub->ubsock)
 421                 udp_tunnel_sock_release(ub->ubsock);
 422         synchronize_net();
 423         kfree(ub);
 424 }
 425
 426 /* tipc_udp_disable - detach bearer from socket */
 427 static void tipc_udp_disable(struct tipc_bearer *b)
 428 {
 429         struct udp_bearer *ub;
 430
 431         ub = rcu_dereference_rtnl(b->media_ptr);
 432         if (!ub) {
 433                 pr_err("UDP bearer instance not found\n");
 434                 return;
 435         }
 436         if (ub->ubsock)
 437                 sock_set_flag(ub->ubsock->sk, SOCK_DEAD);
 438         RCU_INIT_POINTER(b->media_ptr, NULL);
 439         RCU_INIT_POINTER(ub->bearer, NULL);
 440
 441         /* sock_release need to be done outside of rtnl lock */
 442         INIT_WORK(&ub->work, cleanup_bearer);
 443         schedule_work(&ub->work);
 444 }
 445
 446 struct tipc_media udp_media_info = {
 447         .send_msg       = tipc_udp_send_msg,
 448         .enable_media   = tipc_udp_enable,
 449         .disable_media  = tipc_udp_disable,
 450         .addr2str       = tipc_udp_addr2str,
 451         .addr2msg       = tipc_udp_addr2msg,
 452         .msg2addr       = tipc_udp_msg2addr,
 453         .priority       = TIPC_DEF_LINK_PRI,
 454         .tolerance      = TIPC_DEF_LINK_TOL,
 455         .window         = TIPC_DEF_LINK_WIN,
 456         .type_id        = TIPC_MEDIA_TYPE_UDP,
 457         .hwaddr_len     = 0,
 458         .name           = "udp"
 459 };