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 rtable *rt; 160 161 if (skb_headroom(skb) < UDP_MIN_HEADROOM) 162 pskb_expand_head(skb, UDP_MIN_HEADROOM, 0, GFP_ATOMIC); 163 164 skb_set_inner_protocol(skb, htons(ETH_P_TIPC)); 165 ub = rcu_dereference_rtnl(b->media_ptr); 166 if (!ub) { 167 err = -ENODEV; 168 goto tx_error; 169 } 170 if (dst->proto == htons(ETH_P_IP)) { 171 struct flowi4 fl = { 172 .daddr = dst->ipv4.s_addr, 173 .saddr = src->ipv4.s_addr, 174 .flowi4_mark = skb->mark, 175 .flowi4_proto = IPPROTO_UDP 176 }; 177 rt = ip_route_output_key(net, &fl); 178 if (IS_ERR(rt)) { 179 err = PTR_ERR(rt); 180 goto tx_error; 181 } 182 ttl = ip4_dst_hoplimit(&rt->dst); 183 err = udp_tunnel_xmit_skb(rt, ub->ubsock->sk, skb, 184 src->ipv4.s_addr, 185 dst->ipv4.s_addr, 0, ttl, 0, 186 src->udp_port, dst->udp_port, 187 false, true); 188 if (err < 0) { 189 ip_rt_put(rt); 190 goto tx_error; 191 } 192 #if IS_ENABLED(CONFIG_IPV6) 193 } else { 194 struct dst_entry *ndst; 195 struct flowi6 fl6 = { 196 .flowi6_oif = ub->ifindex, 197 .daddr = dst->ipv6, 198 .saddr = src->ipv6, 199 .flowi6_proto = IPPROTO_UDP 200 }; 201 err = ipv6_stub->ipv6_dst_lookup(net, ub->ubsock->sk, &ndst, 202 &fl6); 203 if (err) 204 goto tx_error; 205 ttl = ip6_dst_hoplimit(ndst); 206 err = udp_tunnel6_xmit_skb(ndst, ub->ubsock->sk, skb, 207 ndst->dev, &src->ipv6, 208 &dst->ipv6, 0, ttl, src->udp_port, 209 dst->udp_port, false); 210 #endif 211 } 212 return err; 213 214 tx_error: 215 kfree_skb(skb); 216 return err; 217 } 218 219 /* tipc_udp_recv - read data from bearer socket */ 220 static int tipc_udp_recv(struct sock *sk, struct sk_buff *skb) 221 { 222 struct udp_bearer *ub; 223 struct tipc_bearer *b; 224 int usr = msg_user(buf_msg(skb)); 225 226 if ((usr == LINK_PROTOCOL) || (usr == NAME_DISTRIBUTOR)) 227 skb_linearize(skb); 228 229 ub = rcu_dereference_sk_user_data(sk); 230 if (!ub) { 231 pr_err_ratelimited("Failed to get UDP bearer reference"); 232 kfree_skb(skb); 233 return 0; 234 } 235 236 skb_pull(skb, sizeof(struct udphdr)); 237 rcu_read_lock(); 238 b = rcu_dereference_rtnl(ub->bearer); 239 240 if (b) { 241 tipc_rcv(sock_net(sk), skb, b); 242 rcu_read_unlock(); 243 return 0; 244 } 245 rcu_read_unlock(); 246 kfree_skb(skb); 247 return 0; 248 } 249 250 static int enable_mcast(struct udp_bearer *ub, struct udp_media_addr *remote) 251 { 252 int err = 0; 253 struct ip_mreqn mreqn; 254 struct sock *sk = ub->ubsock->sk; 255 256 if (ntohs(remote->proto) == ETH_P_IP) { 257 if (!ipv4_is_multicast(remote->ipv4.s_addr)) 258 return 0; 259 mreqn.imr_multiaddr = remote->ipv4; 260 mreqn.imr_ifindex = ub->ifindex; 261 err = ip_mc_join_group(sk, &mreqn); 262 #if IS_ENABLED(CONFIG_IPV6) 263 } else { 264 if (!ipv6_addr_is_multicast(&remote->ipv6)) 265 return 0; 266 err = ipv6_stub->ipv6_sock_mc_join(sk, ub->ifindex, 267 &remote->ipv6); 268 #endif 269 } 270 return err; 271 } 272 273 /** 274 * parse_options - build local/remote addresses from configuration 275 * @attrs: netlink config data 276 * @ub: UDP bearer instance 277 * @local: local bearer IP address/port 278 * @remote: peer or multicast IP/port 279 */ 280 static int parse_options(struct nlattr *attrs[], struct udp_bearer *ub, 281 struct udp_media_addr *local, 282 struct udp_media_addr *remote) 283 { 284 struct nlattr *opts[TIPC_NLA_UDP_MAX + 1]; 285 struct sockaddr_storage *sa_local, *sa_remote; 286 287 if (!attrs[TIPC_NLA_BEARER_UDP_OPTS]) 288 goto err; 289 if (nla_parse_nested(opts, TIPC_NLA_UDP_MAX, 290 attrs[TIPC_NLA_BEARER_UDP_OPTS], 291 tipc_nl_udp_policy)) 292 goto err; 293 if (opts[TIPC_NLA_UDP_LOCAL] && opts[TIPC_NLA_UDP_REMOTE]) { 294 sa_local = nla_data(opts[TIPC_NLA_UDP_LOCAL]); 295 sa_remote = nla_data(opts[TIPC_NLA_UDP_REMOTE]); 296 } else { 297 err: 298 pr_err("Invalid UDP bearer configuration"); 299 return -EINVAL; 300 } 301 if ((sa_local->ss_family & sa_remote->ss_family) == AF_INET) { 302 struct sockaddr_in *ip4; 303 304 ip4 = (struct sockaddr_in *)sa_local; 305 local->proto = htons(ETH_P_IP); 306 local->udp_port = ip4->sin_port; 307 local->ipv4.s_addr = ip4->sin_addr.s_addr; 308 309 ip4 = (struct sockaddr_in *)sa_remote; 310 remote->proto = htons(ETH_P_IP); 311 remote->udp_port = ip4->sin_port; 312 remote->ipv4.s_addr = ip4->sin_addr.s_addr; 313 return 0; 314 315 #if IS_ENABLED(CONFIG_IPV6) 316 } else if ((sa_local->ss_family & sa_remote->ss_family) == AF_INET6) { 317 struct sockaddr_in6 *ip6; 318 319 ip6 = (struct sockaddr_in6 *)sa_local; 320 local->proto = htons(ETH_P_IPV6); 321 local->udp_port = ip6->sin6_port; 322 local->ipv6 = ip6->sin6_addr; 323 ub->ifindex = ip6->sin6_scope_id; 324 325 ip6 = (struct sockaddr_in6 *)sa_remote; 326 remote->proto = htons(ETH_P_IPV6); 327 remote->udp_port = ip6->sin6_port; 328 remote->ipv6 = ip6->sin6_addr; 329 return 0; 330 #endif 331 } 332 return -EADDRNOTAVAIL; 333 } 334 335 /** 336 * tipc_udp_enable - callback to create a new udp bearer instance 337 * @net: network namespace 338 * @b: pointer to generic tipc_bearer 339 * @attrs: netlink bearer configuration 340 * 341 * validate the bearer parameters and initialize the udp bearer 342 * rtnl_lock should be held 343 */ 344 static int tipc_udp_enable(struct net *net, struct tipc_bearer *b, 345 struct nlattr *attrs[]) 346 { 347 int err = -EINVAL; 348 struct udp_bearer *ub; 349 struct udp_media_addr *remote; 350 struct udp_media_addr local = {0}; 351 struct udp_port_cfg udp_conf = {0}; 352 struct udp_tunnel_sock_cfg tuncfg = {NULL}; 353 354 ub = kzalloc(sizeof(*ub), GFP_ATOMIC); 355 if (!ub) 356 return -ENOMEM; 357 358 remote = (struct udp_media_addr *)&b->bcast_addr.value; 359 memset(remote, 0, sizeof(struct udp_media_addr)); 360 err = parse_options(attrs, ub, &local, remote); 361 if (err) 362 goto err; 363 364 b->bcast_addr.media_id = TIPC_MEDIA_TYPE_UDP; 365 b->bcast_addr.broadcast = 1; 366 rcu_assign_pointer(b->media_ptr, ub); 367 rcu_assign_pointer(ub->bearer, b); 368 tipc_udp_media_addr_set(&b->addr, &local); 369 if (local.proto == htons(ETH_P_IP)) { 370 struct net_device *dev; 371 372 dev = __ip_dev_find(net, local.ipv4.s_addr, false); 373 if (!dev) { 374 err = -ENODEV; 375 goto err; 376 } 377 udp_conf.family = AF_INET; 378 udp_conf.local_ip.s_addr = htonl(INADDR_ANY); 379 udp_conf.use_udp_checksums = false; 380 ub->ifindex = dev->ifindex; 381 b->mtu = dev->mtu - sizeof(struct iphdr) 382 - sizeof(struct udphdr); 383 #if IS_ENABLED(CONFIG_IPV6) 384 } else if (local.proto == htons(ETH_P_IPV6)) { 385 udp_conf.family = AF_INET6; 386 udp_conf.use_udp6_tx_checksums = true; 387 udp_conf.use_udp6_rx_checksums = true; 388 udp_conf.local_ip6 = in6addr_any; 389 b->mtu = 1280; 390 #endif 391 } else { 392 err = -EAFNOSUPPORT; 393 goto err; 394 } 395 udp_conf.local_udp_port = local.udp_port; 396 err = udp_sock_create(net, &udp_conf, &ub->ubsock); 397 if (err) 398 goto err; 399 tuncfg.sk_user_data = ub; 400 tuncfg.encap_type = 1; 401 tuncfg.encap_rcv = tipc_udp_recv; 402 tuncfg.encap_destroy = NULL; 403 setup_udp_tunnel_sock(net, ub->ubsock, &tuncfg); 404 405 if (enable_mcast(ub, remote)) 406 goto err; 407 return 0; 408 err: 409 kfree(ub); 410 return err; 411 } 412 413 /* cleanup_bearer - break the socket/bearer association */ 414 static void cleanup_bearer(struct work_struct *work) 415 { 416 struct udp_bearer *ub = container_of(work, struct udp_bearer, work); 417 418 if (ub->ubsock) 419 udp_tunnel_sock_release(ub->ubsock); 420 synchronize_net(); 421 kfree(ub); 422 } 423 424 /* tipc_udp_disable - detach bearer from socket */ 425 static void tipc_udp_disable(struct tipc_bearer *b) 426 { 427 struct udp_bearer *ub; 428 429 ub = rcu_dereference_rtnl(b->media_ptr); 430 if (!ub) { 431 pr_err("UDP bearer instance not found\n"); 432 return; 433 } 434 if (ub->ubsock) 435 sock_set_flag(ub->ubsock->sk, SOCK_DEAD); 436 RCU_INIT_POINTER(ub->bearer, NULL); 437 438 /* sock_release need to be done outside of rtnl lock */ 439 INIT_WORK(&ub->work, cleanup_bearer); 440 schedule_work(&ub->work); 441 } 442 443 struct tipc_media udp_media_info = { 444 .send_msg = tipc_udp_send_msg, 445 .enable_media = tipc_udp_enable, 446 .disable_media = tipc_udp_disable, 447 .addr2str = tipc_udp_addr2str, 448 .addr2msg = tipc_udp_addr2msg, 449 .msg2addr = tipc_udp_msg2addr, 450 .priority = TIPC_DEF_LINK_PRI, 451 .tolerance = TIPC_DEF_LINK_TOL, 452 .window = TIPC_DEF_LINK_WIN, 453 .type_id = TIPC_MEDIA_TYPE_UDP, 454 .hwaddr_len = 0, 455 .name = "udp" 456 }; 457