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
  52 /* IANA assigned UDP port */
  53 #define UDP_PORT_DEFAULT        6118
  54
  55 static const struct nla_policy tipc_nl_udp_policy[TIPC_NLA_UDP_MAX + 1] = {
  56         [TIPC_NLA_UDP_UNSPEC]   = {.type = NLA_UNSPEC},
  57         [TIPC_NLA_UDP_LOCAL]    = {.type = NLA_BINARY,
  58                                    .len = sizeof(struct sockaddr_storage)},
  59         [TIPC_NLA_UDP_REMOTE]   = {.type = NLA_BINARY,
  60                                    .len = sizeof(struct sockaddr_storage)},
  61 };
  62
  63 /**
  64  * struct udp_media_addr - IP/UDP addressing information
  65  *
  66  * This is the bearer level originating address used in neighbor discovery
  67  * messages, and all fields should be in network byte order
  68  */
  69 struct udp_media_addr {
  70         __be16  proto;
  71         __be16  udp_port;
  72         union {
  73                 struct in_addr ipv4;
  74                 struct in6_addr ipv6;
  75         };
  76 };
  77
  78 /**
  79  * struct udp_bearer - ip/udp bearer data structure
  80  * @bearer:     associated generic tipc bearer
  81  * @ubsock:     bearer associated socket
  82  * @ifindex:    local address scope
  83  * @work:       used to schedule deferred work on a bearer
  84  */
  85 struct udp_bearer {
  86         struct tipc_bearer __rcu *bearer;
  87         struct socket *ubsock;
  88         u32 ifindex;
  89         struct work_struct work;
  90 };
  91
  92 /* udp_media_addr_set - convert a ip/udp address to a TIPC media address */
  93 static void tipc_udp_media_addr_set(struct tipc_media_addr *addr,
  94                                     struct udp_media_addr *ua)
  95 {
  96         memset(addr, 0, sizeof(struct tipc_media_addr));
  97         addr->media_id = TIPC_MEDIA_TYPE_UDP;
  98         memcpy(addr->value, ua, sizeof(struct udp_media_addr));
  99         if (ntohs(ua->proto) == ETH_P_IP) {
 100                 if (ipv4_is_multicast(ua->ipv4.s_addr))
 101                         addr->broadcast = 1;
 102         } else if (ntohs(ua->proto) == ETH_P_IPV6) {
 103                 if (ipv6_addr_type(&ua->ipv6) & IPV6_ADDR_MULTICAST)
 104                         addr->broadcast = 1;
 105         } else {
 106                 pr_err("Invalid UDP media address\n");
 107         }
 108 }
 109
 110 /* tipc_udp_addr2str - convert ip/udp address to string */
 111 static int tipc_udp_addr2str(struct tipc_media_addr *a, char *buf, int size)
 112 {
 113         struct udp_media_addr *ua = (struct udp_media_addr *)&a->value;
 114
 115         if (ntohs(ua->proto) == ETH_P_IP)
 116                 snprintf(buf, size, "%pI4:%u", &ua->ipv4, ntohs(ua->udp_port));
 117         else if (ntohs(ua->proto) == ETH_P_IPV6)
 118                 snprintf(buf, size, "%pI6:%u", &ua->ipv6, ntohs(ua->udp_port));
 119         else
 120                 pr_err("Invalid UDP media address\n");
 121         return 0;
 122 }
 123
 124 /* tipc_udp_msg2addr - extract an ip/udp address from a TIPC ndisc message */
 125 static int tipc_udp_msg2addr(struct tipc_bearer *b, struct tipc_media_addr *a,
 126                              char *msg)
 127 {
 128         struct udp_media_addr *ua;
 129
 130         ua = (struct udp_media_addr *) (msg + TIPC_MEDIA_ADDR_OFFSET);
 131         if (msg[TIPC_MEDIA_TYPE_OFFSET] != TIPC_MEDIA_TYPE_UDP)
 132                 return -EINVAL;
 133         tipc_udp_media_addr_set(a, ua);
 134         return 0;
 135 }
 136
 137 /* tipc_udp_addr2msg - write an ip/udp address to a TIPC ndisc message */
 138 static int tipc_udp_addr2msg(char *msg, struct tipc_media_addr *a)
 139 {
 140         memset(msg, 0, TIPC_MEDIA_INFO_SIZE);
 141         msg[TIPC_MEDIA_TYPE_OFFSET] = TIPC_MEDIA_TYPE_UDP;
 142         memcpy(msg + TIPC_MEDIA_ADDR_OFFSET, a->value,
 143                sizeof(struct udp_media_addr));
 144         return 0;
 145 }
 146
 147 /* tipc_send_msg - enqueue a send request */
 148 static int tipc_udp_send_msg(struct net *net, struct sk_buff *skb,
 149                              struct tipc_bearer *b,
 150                              struct tipc_media_addr *dest)
 151 {
 152         int ttl, err = 0;
 153         struct udp_bearer *ub;
 154         struct udp_media_addr *dst = (struct udp_media_addr *)&dest->value;
 155         struct udp_media_addr *src = (struct udp_media_addr *)&b->addr.value;
 156         struct sk_buff *clone;
 157         struct rtable *rt;
 158
 159         clone = skb_clone(skb, GFP_ATOMIC);
 160         skb_set_inner_protocol(clone, htons(ETH_P_TIPC));
 161         ub = rcu_dereference_rtnl(b->media_ptr);
 162         if (!ub) {
 163                 err = -ENODEV;
 164                 goto tx_error;
 165         }
 166         if (dst->proto == htons(ETH_P_IP)) {
 167                 struct flowi4 fl = {
 168                         .daddr = dst->ipv4.s_addr,
 169                         .saddr = src->ipv4.s_addr,
 170                         .flowi4_mark = clone->mark,
 171                         .flowi4_proto = IPPROTO_UDP
 172                 };
 173                 rt = ip_route_output_key(net, &fl);
 174                 if (IS_ERR(rt)) {
 175                         err = PTR_ERR(rt);
 176                         goto tx_error;
 177                 }
 178                 ttl = ip4_dst_hoplimit(&rt->dst);
 179                 err = udp_tunnel_xmit_skb(rt, ub->ubsock->sk, clone,
 180                                           src->ipv4.s_addr,
 181                                           dst->ipv4.s_addr, 0, ttl, 0,
 182                                           src->udp_port, dst->udp_port,
 183                                           false, true);
 184                 if (err < 0) {
 185                         ip_rt_put(rt);
 186                         goto tx_error;
 187                 }
 188 #if IS_ENABLED(CONFIG_IPV6)
 189         } else {
 190                 struct dst_entry *ndst;
 191                 struct flowi6 fl6 = {
 192                         .flowi6_oif = ub->ifindex,
 193                         .daddr = dst->ipv6,
 194                         .saddr = src->ipv6,
 195                         .flowi6_proto = IPPROTO_UDP
 196                 };
 197                 err = ipv6_stub->ipv6_dst_lookup(ub->ubsock->sk, &ndst, &fl6);
 198                 if (err)
 199                         goto tx_error;
 200                 ttl = ip6_dst_hoplimit(ndst);
 201                 err = udp_tunnel6_xmit_skb(ndst, ub->ubsock->sk, clone,
 202                                            ndst->dev, &src->ipv6,
 203                                            &dst->ipv6, 0, ttl, src->udp_port,
 204                                            dst->udp_port, false);
 205 #endif
 206         }
 207         return err;
 208
 209 tx_error:
 210         kfree_skb(clone);
 211         return err;
 212 }
 213
 214 /* tipc_udp_recv - read data from bearer socket */
 215 static int tipc_udp_recv(struct sock *sk, struct sk_buff *skb)
 216 {
 217         struct udp_bearer *ub;
 218         struct tipc_bearer *b;
 219
 220         ub = rcu_dereference_sk_user_data(sk);
 221         if (!ub) {
 222                 pr_err_ratelimited("Failed to get UDP bearer reference");
 223                 kfree_skb(skb);
 224                 return 0;
 225         }
 226
 227         skb_pull(skb, sizeof(struct udphdr));
 228         rcu_read_lock();
 229         b = rcu_dereference_rtnl(ub->bearer);
 230
 231         if (b) {
 232                 tipc_rcv(sock_net(sk), skb, b);
 233                 rcu_read_unlock();
 234                 return 0;
 235         }
 236         rcu_read_unlock();
 237         kfree_skb(skb);
 238         return 0;
 239 }
 240
 241 static int enable_mcast(struct udp_bearer *ub, struct udp_media_addr *remote)
 242 {
 243         int err = 0;
 244         struct ip_mreqn mreqn;
 245         struct sock *sk = ub->ubsock->sk;
 246
 247         if (ntohs(remote->proto) == ETH_P_IP) {
 248                 if (!ipv4_is_multicast(remote->ipv4.s_addr))
 249                         return 0;
 250                 mreqn.imr_multiaddr = remote->ipv4;
 251                 mreqn.imr_ifindex = ub->ifindex;
 252                 err = ip_mc_join_group(sk, &mreqn);
 253 #if IS_ENABLED(CONFIG_IPV6)
 254         } else {
 255                 if (!ipv6_addr_is_multicast(&remote->ipv6))
 256                         return 0;
 257                 err = ipv6_stub->ipv6_sock_mc_join(sk, ub->ifindex,
 258                                                    &remote->ipv6);
 259 #endif
 260         }
 261         return err;
 262 }
 263
 264 /**
 265  * parse_options - build local/remote addresses from configuration
 266  * @attrs:      netlink config data
 267  * @ub:         UDP bearer instance
 268  * @local:      local bearer IP address/port
 269  * @remote:     peer or multicast IP/port
 270  */
 271 static int parse_options(struct nlattr *attrs[], struct udp_bearer *ub,
 272                          struct udp_media_addr *local,
 273                          struct udp_media_addr *remote)
 274 {
 275         struct nlattr *opts[TIPC_NLA_UDP_MAX + 1];
 276         struct sockaddr_storage *sa_local, *sa_remote;
 277
 278         if (!attrs[TIPC_NLA_BEARER_UDP_OPTS])
 279                 goto err;
 280         if (nla_parse_nested(opts, TIPC_NLA_UDP_MAX,
 281                              attrs[TIPC_NLA_BEARER_UDP_OPTS],
 282                              tipc_nl_udp_policy))
 283                 goto err;
 284         if (opts[TIPC_NLA_UDP_LOCAL] && opts[TIPC_NLA_UDP_REMOTE]) {
 285                 sa_local = nla_data(opts[TIPC_NLA_UDP_LOCAL]);
 286                 sa_remote = nla_data(opts[TIPC_NLA_UDP_REMOTE]);
 287         } else {
 288 err:
 289                 pr_err("Invalid UDP bearer configuration");
 290                 return -EINVAL;
 291         }
 292         if ((sa_local->ss_family & sa_remote->ss_family) == AF_INET) {
 293                 struct sockaddr_in *ip4;
 294
 295                 ip4 = (struct sockaddr_in *)sa_local;
 296                 local->proto = htons(ETH_P_IP);
 297                 local->udp_port = ip4->sin_port;
 298                 local->ipv4.s_addr = ip4->sin_addr.s_addr;
 299
 300                 ip4 = (struct sockaddr_in *)sa_remote;
 301                 remote->proto = htons(ETH_P_IP);
 302                 remote->udp_port = ip4->sin_port;
 303                 remote->ipv4.s_addr = ip4->sin_addr.s_addr;
 304                 return 0;
 305
 306 #if IS_ENABLED(CONFIG_IPV6)
 307         } else if ((sa_local->ss_family & sa_remote->ss_family) == AF_INET6) {
 308                 struct sockaddr_in6 *ip6;
 309
 310                 ip6 = (struct sockaddr_in6 *)sa_local;
 311                 local->proto = htons(ETH_P_IPV6);
 312                 local->udp_port = ip6->sin6_port;
 313                 local->ipv6 = ip6->sin6_addr;
 314                 ub->ifindex = ip6->sin6_scope_id;
 315
 316                 ip6 = (struct sockaddr_in6 *)sa_remote;
 317                 remote->proto = htons(ETH_P_IPV6);
 318                 remote->udp_port = ip6->sin6_port;
 319                 remote->ipv6 = ip6->sin6_addr;
 320                 return 0;
 321 #endif
 322         }
 323         return -EADDRNOTAVAIL;
 324 }
 325
 326 /**
 327  * tipc_udp_enable - callback to create a new udp bearer instance
 328  * @net:        network namespace
 329  * @b:          pointer to generic tipc_bearer
 330  * @attrs:      netlink bearer configuration
 331  *
 332  * validate the bearer parameters and initialize the udp bearer
 333  * rtnl_lock should be held
 334  */
 335 static int tipc_udp_enable(struct net *net, struct tipc_bearer *b,
 336                            struct nlattr *attrs[])
 337 {
 338         int err = -EINVAL;
 339         struct udp_bearer *ub;
 340         struct udp_media_addr *remote;
 341         struct udp_media_addr local = {0};
 342         struct udp_port_cfg udp_conf = {0};
 343         struct udp_tunnel_sock_cfg tuncfg = {NULL};
 344
 345         ub = kzalloc(sizeof(*ub), GFP_ATOMIC);
 346         if (!ub)
 347                 return -ENOMEM;
 348
 349         remote = (struct udp_media_addr *)&b->bcast_addr.value;
 350         memset(remote, 0, sizeof(struct udp_media_addr));
 351         err = parse_options(attrs, ub, &local, remote);
 352         if (err)
 353                 goto err;
 354
 355         b->bcast_addr.media_id = TIPC_MEDIA_TYPE_UDP;
 356         b->bcast_addr.broadcast = 1;
 357         rcu_assign_pointer(b->media_ptr, ub);
 358         rcu_assign_pointer(ub->bearer, b);
 359         tipc_udp_media_addr_set(&b->addr, &local);
 360         if (local.proto == htons(ETH_P_IP)) {
 361                 struct net_device *dev;
 362
 363                 dev = __ip_dev_find(net, local.ipv4.s_addr, false);
 364                 if (!dev) {
 365                         err = -ENODEV;
 366                         goto err;
 367                 }
 368                 udp_conf.family = AF_INET;
 369                 udp_conf.local_ip.s_addr = htonl(INADDR_ANY);
 370                 udp_conf.use_udp_checksums = false;
 371                 ub->ifindex = dev->ifindex;
 372                 b->mtu = dev->mtu - sizeof(struct iphdr)
 373                         - sizeof(struct udphdr);
 374 #if IS_ENABLED(CONFIG_IPV6)
 375         } else if (local.proto == htons(ETH_P_IPV6)) {
 376                 udp_conf.family = AF_INET6;
 377                 udp_conf.use_udp6_tx_checksums = true;
 378                 udp_conf.use_udp6_rx_checksums = true;
 379                 udp_conf.local_ip6 = in6addr_any;
 380                 b->mtu = 1280;
 381 #endif
 382         } else {
 383                 err = -EAFNOSUPPORT;
 384                 goto err;
 385         }
 386         udp_conf.local_udp_port = local.udp_port;
 387         err = udp_sock_create(net, &udp_conf, &ub->ubsock);
 388         if (err)
 389                 goto err;
 390         tuncfg.sk_user_data = ub;
 391         tuncfg.encap_type = 1;
 392         tuncfg.encap_rcv = tipc_udp_recv;
 393         tuncfg.encap_destroy = NULL;
 394         setup_udp_tunnel_sock(net, ub->ubsock, &tuncfg);
 395
 396         if (enable_mcast(ub, remote))
 397                 goto err;
 398         return 0;
 399 err:
 400         kfree(ub);
 401         return err;
 402 }
 403
 404 /* cleanup_bearer - break the socket/bearer association */
 405 static void cleanup_bearer(struct work_struct *work)
 406 {
 407         struct udp_bearer *ub = container_of(work, struct udp_bearer, work);
 408
 409         if (ub->ubsock)
 410                 udp_tunnel_sock_release(ub->ubsock);
 411         synchronize_net();
 412         kfree(ub);
 413 }
 414
 415 /* tipc_udp_disable - detach bearer from socket */
 416 static void tipc_udp_disable(struct tipc_bearer *b)
 417 {
 418         struct udp_bearer *ub;
 419
 420         ub = rcu_dereference_rtnl(b->media_ptr);
 421         if (!ub) {
 422                 pr_err("UDP bearer instance not found\n");
 423                 return;
 424         }
 425         if (ub->ubsock)
 426                 sock_set_flag(ub->ubsock->sk, SOCK_DEAD);
 427         RCU_INIT_POINTER(b->media_ptr, NULL);
 428         RCU_INIT_POINTER(ub->bearer, NULL);
 429
 430         /* sock_release need to be done outside of rtnl lock */
 431         INIT_WORK(&ub->work, cleanup_bearer);
 432         schedule_work(&ub->work);
 433 }
 434
 435 struct tipc_media udp_media_info = {
 436         .send_msg       = tipc_udp_send_msg,
 437         .enable_media   = tipc_udp_enable,
 438         .disable_media  = tipc_udp_disable,
 439         .addr2str       = tipc_udp_addr2str,
 440         .addr2msg       = tipc_udp_addr2msg,
 441         .msg2addr       = tipc_udp_msg2addr,
 442         .priority       = TIPC_DEF_LINK_PRI,
 443         .tolerance      = TIPC_DEF_LINK_TOL,
 444         .window         = TIPC_DEF_LINK_WIN,
 445         .type_id        = TIPC_MEDIA_TYPE_UDP,
 446         .hwaddr_len     = 0,
 447         .name           = "udp"
 448 };