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 #define UDP_MIN_HEADROOM 28 56 57 static const struct nla_policy tipc_nl_udp_policy[TIPC_NLA_UDP_MAX + 1] = { 58 [TIPC_NLA_UDP_UNSPEC] = {.type = NLA_UNSPEC}, 59 [TIPC_NLA_UDP_LOCAL] = {.type = NLA_BINARY, 60 .len = sizeof(struct sockaddr_storage)}, 61 [TIPC_NLA_UDP_REMOTE] = {.type = NLA_BINARY, 62 .len = sizeof(struct sockaddr_storage)}, 63 }; 64 65 /** 66 * struct udp_media_addr - IP/UDP addressing information 67 * 68 * This is the bearer level originating address used in neighbor discovery 69 * messages, and all fields should be in network byte order 70 */ 71 struct udp_media_addr { 72 __be16 proto; 73 __be16 udp_port; 74 union { 75 struct in_addr ipv4; 76 struct in6_addr ipv6; 77 }; 78 }; 79 80 /** 81 * struct udp_bearer - ip/udp bearer data structure 82 * @bearer: associated generic tipc bearer 83 * @ubsock: bearer associated socket 84 * @ifindex: local address scope 85 * @work: used to schedule deferred work on a bearer 86 */ 87 struct udp_bearer { 88 struct tipc_bearer __rcu *bearer; 89 struct socket *ubsock; 90 u32 ifindex; 91 struct work_struct work; 92 }; 93 94 /* udp_media_addr_set - convert a ip/udp address to a TIPC media address */ 95 static void tipc_udp_media_addr_set(struct tipc_media_addr *addr, 96 struct udp_media_addr *ua) 97 { 98 memset(addr, 0, sizeof(struct tipc_media_addr)); 99 addr->media_id = TIPC_MEDIA_TYPE_UDP; 100 memcpy(addr->value, ua, sizeof(struct udp_media_addr)); 101 if (ntohs(ua->proto) == ETH_P_IP) { 102 if (ipv4_is_multicast(ua->ipv4.s_addr)) 103 addr->broadcast = 1; 104 } else if (ntohs(ua->proto) == ETH_P_IPV6) { 105 if (ipv6_addr_type(&ua->ipv6) & IPV6_ADDR_MULTICAST) 106 addr->broadcast = 1; 107 } else { 108 pr_err("Invalid UDP media address\n"); 109 } 110 } 111 112 /* tipc_udp_addr2str - convert ip/udp address to string */ 113 static int tipc_udp_addr2str(struct tipc_media_addr *a, char *buf, int size) 114 { 115 struct udp_media_addr *ua = (struct udp_media_addr *)&a->value; 116 117 if (ntohs(ua->proto) == ETH_P_IP) 118 snprintf(buf, size, "%pI4:%u", &ua->ipv4, ntohs(ua->udp_port)); 119 else if (ntohs(ua->proto) == ETH_P_IPV6) 120 snprintf(buf, size, "%pI6:%u", &ua->ipv6, ntohs(ua->udp_port)); 121 else 122 pr_err("Invalid UDP media address\n"); 123 return 0; 124 } 125 126 /* tipc_udp_msg2addr - extract an ip/udp address from a TIPC ndisc message */ 127 static int tipc_udp_msg2addr(struct tipc_bearer *b, struct tipc_media_addr *a, 128 char *msg) 129 { 130 struct udp_media_addr *ua; 131 132 ua = (struct udp_media_addr *) (msg + TIPC_MEDIA_ADDR_OFFSET); 133 if (msg[TIPC_MEDIA_TYPE_OFFSET] != TIPC_MEDIA_TYPE_UDP) 134 return -EINVAL; 135 tipc_udp_media_addr_set(a, ua); 136 return 0; 137 } 138 139 /* tipc_udp_addr2msg - write an ip/udp address to a TIPC ndisc message */ 140 static int tipc_udp_addr2msg(char *msg, struct tipc_media_addr *a) 141 { 142 memset(msg, 0, TIPC_MEDIA_INFO_SIZE); 143 msg[TIPC_MEDIA_TYPE_OFFSET] = TIPC_MEDIA_TYPE_UDP; 144 memcpy(msg + TIPC_MEDIA_ADDR_OFFSET, a->value, 145 sizeof(struct udp_media_addr)); 146 return 0; 147 } 148 149 /* tipc_send_msg - enqueue a send request */ 150 static int tipc_udp_send_msg(struct net *net, struct sk_buff *skb, 151 struct tipc_bearer *b, 152 struct tipc_media_addr *dest) 153 { 154 int ttl, err = 0; 155 struct udp_bearer *ub; 156 struct udp_media_addr *dst = (struct udp_media_addr *)&dest->value; 157 struct udp_media_addr *src = (struct udp_media_addr *)&b->addr.value; 158 struct sk_buff *clone; 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 clone = skb_clone(skb, GFP_ATOMIC); 165 skb_set_inner_protocol(clone, htons(ETH_P_TIPC)); 166 ub = rcu_dereference_rtnl(b->media_ptr); 167 if (!ub) { 168 err = -ENODEV; 169 goto tx_error; 170 } 171 if (dst->proto == htons(ETH_P_IP)) { 172 struct flowi4 fl = { 173 .daddr = dst->ipv4.s_addr, 174 .saddr = src->ipv4.s_addr, 175 .flowi4_mark = clone->mark, 176 .flowi4_proto = IPPROTO_UDP 177 }; 178 rt = ip_route_output_key(net, &fl); 179 if (IS_ERR(rt)) { 180 err = PTR_ERR(rt); 181 goto tx_error; 182 } 183 ttl = ip4_dst_hoplimit(&rt->dst); 184 err = udp_tunnel_xmit_skb(rt, ub->ubsock->sk, clone, 185 src->ipv4.s_addr, 186 dst->ipv4.s_addr, 0, ttl, 0, 187 src->udp_port, dst->udp_port, 188 false, true); 189 if (err < 0) { 190 ip_rt_put(rt); 191 goto tx_error; 192 } 193 #if IS_ENABLED(CONFIG_IPV6) 194 } else { 195 struct dst_entry *ndst; 196 struct flowi6 fl6 = { 197 .flowi6_oif = ub->ifindex, 198 .daddr = dst->ipv6, 199 .saddr = src->ipv6, 200 .flowi6_proto = IPPROTO_UDP 201 }; 202 err = ipv6_stub->ipv6_dst_lookup(net, ub->ubsock->sk, &ndst, 203 &fl6); 204 if (err) 205 goto tx_error; 206 ttl = ip6_dst_hoplimit(ndst); 207 err = udp_tunnel6_xmit_skb(ndst, ub->ubsock->sk, clone, 208 ndst->dev, &src->ipv6, 209 &dst->ipv6, 0, ttl, src->udp_port, 210 dst->udp_port, false); 211 #endif 212 } 213 return err; 214 215 tx_error: 216 kfree_skb(clone); 217 return err; 218 } 219 220 /* tipc_udp_recv - read data from bearer socket */ 221 static int tipc_udp_recv(struct sock *sk, struct sk_buff *skb) 222 { 223 struct udp_bearer *ub; 224 struct tipc_bearer *b; 225 226 ub = rcu_dereference_sk_user_data(sk); 227 if (!ub) { 228 pr_err_ratelimited("Failed to get UDP bearer reference"); 229 kfree_skb(skb); 230 return 0; 231 } 232 233 skb_pull(skb, sizeof(struct udphdr)); 234 rcu_read_lock(); 235 b = rcu_dereference_rtnl(ub->bearer); 236 237 if (b) { 238 tipc_rcv(sock_net(sk), skb, b); 239 rcu_read_unlock(); 240 return 0; 241 } 242 rcu_read_unlock(); 243 kfree_skb(skb); 244 return 0; 245 } 246 247 static int enable_mcast(struct udp_bearer *ub, struct udp_media_addr *remote) 248 { 249 int err = 0; 250 struct ip_mreqn mreqn; 251 struct sock *sk = ub->ubsock->sk; 252 253 if (ntohs(remote->proto) == ETH_P_IP) { 254 if (!ipv4_is_multicast(remote->ipv4.s_addr)) 255 return 0; 256 mreqn.imr_multiaddr = remote->ipv4; 257 mreqn.imr_ifindex = ub->ifindex; 258 err = ip_mc_join_group(sk, &mreqn); 259 #if IS_ENABLED(CONFIG_IPV6) 260 } else { 261 if (!ipv6_addr_is_multicast(&remote->ipv6)) 262 return 0; 263 err = ipv6_stub->ipv6_sock_mc_join(sk, ub->ifindex, 264 &remote->ipv6); 265 #endif 266 } 267 return err; 268 } 269 270 /** 271 * parse_options - build local/remote addresses from configuration 272 * @attrs: netlink config data 273 * @ub: UDP bearer instance 274 * @local: local bearer IP address/port 275 * @remote: peer or multicast IP/port 276 */ 277 static int parse_options(struct nlattr *attrs[], struct udp_bearer *ub, 278 struct udp_media_addr *local, 279 struct udp_media_addr *remote) 280 { 281 struct nlattr *opts[TIPC_NLA_UDP_MAX + 1]; 282 struct sockaddr_storage *sa_local, *sa_remote; 283 284 if (!attrs[TIPC_NLA_BEARER_UDP_OPTS]) 285 goto err; 286 if (nla_parse_nested(opts, TIPC_NLA_UDP_MAX, 287 attrs[TIPC_NLA_BEARER_UDP_OPTS], 288 tipc_nl_udp_policy)) 289 goto err; 290 if (opts[TIPC_NLA_UDP_LOCAL] && opts[TIPC_NLA_UDP_REMOTE]) { 291 sa_local = nla_data(opts[TIPC_NLA_UDP_LOCAL]); 292 sa_remote = nla_data(opts[TIPC_NLA_UDP_REMOTE]); 293 } else { 294 err: 295 pr_err("Invalid UDP bearer configuration"); 296 return -EINVAL; 297 } 298 if ((sa_local->ss_family & sa_remote->ss_family) == AF_INET) { 299 struct sockaddr_in *ip4; 300 301 ip4 = (struct sockaddr_in *)sa_local; 302 local->proto = htons(ETH_P_IP); 303 local->udp_port = ip4->sin_port; 304 local->ipv4.s_addr = ip4->sin_addr.s_addr; 305 306 ip4 = (struct sockaddr_in *)sa_remote; 307 remote->proto = htons(ETH_P_IP); 308 remote->udp_port = ip4->sin_port; 309 remote->ipv4.s_addr = ip4->sin_addr.s_addr; 310 return 0; 311 312 #if IS_ENABLED(CONFIG_IPV6) 313 } else if ((sa_local->ss_family & sa_remote->ss_family) == AF_INET6) { 314 struct sockaddr_in6 *ip6; 315 316 ip6 = (struct sockaddr_in6 *)sa_local; 317 local->proto = htons(ETH_P_IPV6); 318 local->udp_port = ip6->sin6_port; 319 local->ipv6 = ip6->sin6_addr; 320 ub->ifindex = ip6->sin6_scope_id; 321 322 ip6 = (struct sockaddr_in6 *)sa_remote; 323 remote->proto = htons(ETH_P_IPV6); 324 remote->udp_port = ip6->sin6_port; 325 remote->ipv6 = ip6->sin6_addr; 326 return 0; 327 #endif 328 } 329 return -EADDRNOTAVAIL; 330 } 331 332 /** 333 * tipc_udp_enable - callback to create a new udp bearer instance 334 * @net: network namespace 335 * @b: pointer to generic tipc_bearer 336 * @attrs: netlink bearer configuration 337 * 338 * validate the bearer parameters and initialize the udp bearer 339 * rtnl_lock should be held 340 */ 341 static int tipc_udp_enable(struct net *net, struct tipc_bearer *b, 342 struct nlattr *attrs[]) 343 { 344 int err = -EINVAL; 345 struct udp_bearer *ub; 346 struct udp_media_addr *remote; 347 struct udp_media_addr local = {0}; 348 struct udp_port_cfg udp_conf = {0}; 349 struct udp_tunnel_sock_cfg tuncfg = {NULL}; 350 351 ub = kzalloc(sizeof(*ub), GFP_ATOMIC); 352 if (!ub) 353 return -ENOMEM; 354 355 remote = (struct udp_media_addr *)&b->bcast_addr.value; 356 memset(remote, 0, sizeof(struct udp_media_addr)); 357 err = parse_options(attrs, ub, &local, remote); 358 if (err) 359 goto err; 360 361 b->bcast_addr.media_id = TIPC_MEDIA_TYPE_UDP; 362 b->bcast_addr.broadcast = 1; 363 rcu_assign_pointer(b->media_ptr, ub); 364 rcu_assign_pointer(ub->bearer, b); 365 tipc_udp_media_addr_set(&b->addr, &local); 366 if (local.proto == htons(ETH_P_IP)) { 367 struct net_device *dev; 368 369 dev = __ip_dev_find(net, local.ipv4.s_addr, false); 370 if (!dev) { 371 err = -ENODEV; 372 goto err; 373 } 374 udp_conf.family = AF_INET; 375 udp_conf.local_ip.s_addr = htonl(INADDR_ANY); 376 udp_conf.use_udp_checksums = false; 377 ub->ifindex = dev->ifindex; 378 b->mtu = dev->mtu - sizeof(struct iphdr) 379 - sizeof(struct udphdr); 380 #if IS_ENABLED(CONFIG_IPV6) 381 } else if (local.proto == htons(ETH_P_IPV6)) { 382 udp_conf.family = AF_INET6; 383 udp_conf.use_udp6_tx_checksums = true; 384 udp_conf.use_udp6_rx_checksums = true; 385 udp_conf.local_ip6 = in6addr_any; 386 b->mtu = 1280; 387 #endif 388 } else { 389 err = -EAFNOSUPPORT; 390 goto err; 391 } 392 udp_conf.local_udp_port = local.udp_port; 393 err = udp_sock_create(net, &udp_conf, &ub->ubsock); 394 if (err) 395 goto err; 396 tuncfg.sk_user_data = ub; 397 tuncfg.encap_type = 1; 398 tuncfg.encap_rcv = tipc_udp_recv; 399 tuncfg.encap_destroy = NULL; 400 setup_udp_tunnel_sock(net, ub->ubsock, &tuncfg); 401 402 if (enable_mcast(ub, remote)) 403 goto err; 404 return 0; 405 err: 406 kfree(ub); 407 return err; 408 } 409 410 /* cleanup_bearer - break the socket/bearer association */ 411 static void cleanup_bearer(struct work_struct *work) 412 { 413 struct udp_bearer *ub = container_of(work, struct udp_bearer, work); 414 415 if (ub->ubsock) 416 udp_tunnel_sock_release(ub->ubsock); 417 synchronize_net(); 418 kfree(ub); 419 } 420 421 /* tipc_udp_disable - detach bearer from socket */ 422 static void tipc_udp_disable(struct tipc_bearer *b) 423 { 424 struct udp_bearer *ub; 425 426 ub = rcu_dereference_rtnl(b->media_ptr); 427 if (!ub) { 428 pr_err("UDP bearer instance not found\n"); 429 return; 430 } 431 if (ub->ubsock) 432 sock_set_flag(ub->ubsock->sk, SOCK_DEAD); 433 RCU_INIT_POINTER(b->media_ptr, NULL); 434 RCU_INIT_POINTER(ub->bearer, NULL); 435 436 /* sock_release need to be done outside of rtnl lock */ 437 INIT_WORK(&ub->work, cleanup_bearer); 438 schedule_work(&ub->work); 439 } 440 441 struct tipc_media udp_media_info = { 442 .send_msg = tipc_udp_send_msg, 443 .enable_media = tipc_udp_enable, 444 .disable_media = tipc_udp_disable, 445 .addr2str = tipc_udp_addr2str, 446 .addr2msg = tipc_udp_addr2msg, 447 .msg2addr = tipc_udp_msg2addr, 448 .priority = TIPC_DEF_LINK_PRI, 449 .tolerance = TIPC_DEF_LINK_TOL, 450 .window = TIPC_DEF_LINK_WIN, 451 .type_id = TIPC_MEDIA_TYPE_UDP, 452 .hwaddr_len = 0, 453 .name = "udp" 454 }; 455