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 rtable *rt; 159 160 if (skb_headroom(skb) < UDP_MIN_HEADROOM) { 161 err = pskb_expand_head(skb, UDP_MIN_HEADROOM, 0, GFP_ATOMIC); 162 if (err) 163 goto tx_error; 164 } 165 166 skb_set_inner_protocol(skb, 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 = skb->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 udp_tunnel_xmit_skb(rt, ub->ubsock->sk, skb, src->ipv4.s_addr, 186 dst->ipv4.s_addr, 0, ttl, 0, src->udp_port, 187 dst->udp_port, false, true); 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(net, ub->ubsock->sk, &ndst, 198 &fl6); 199 if (err) 200 goto tx_error; 201 ttl = ip6_dst_hoplimit(ndst); 202 err = udp_tunnel6_xmit_skb(ndst, ub->ubsock->sk, skb, 203 ndst->dev, &src->ipv6, 204 &dst->ipv6, 0, ttl, src->udp_port, 205 dst->udp_port, false); 206 #endif 207 } 208 return err; 209 210 tx_error: 211 kfree_skb(skb); 212 return err; 213 } 214 215 /* tipc_udp_recv - read data from bearer socket */ 216 static int tipc_udp_recv(struct sock *sk, struct sk_buff *skb) 217 { 218 struct udp_bearer *ub; 219 struct tipc_bearer *b; 220 221 ub = rcu_dereference_sk_user_data(sk); 222 if (!ub) { 223 pr_err_ratelimited("Failed to get UDP bearer reference"); 224 kfree_skb(skb); 225 return 0; 226 } 227 228 skb_pull(skb, sizeof(struct udphdr)); 229 rcu_read_lock(); 230 b = rcu_dereference_rtnl(ub->bearer); 231 232 if (b) { 233 tipc_rcv(sock_net(sk), skb, b); 234 rcu_read_unlock(); 235 return 0; 236 } 237 rcu_read_unlock(); 238 kfree_skb(skb); 239 return 0; 240 } 241 242 static int enable_mcast(struct udp_bearer *ub, struct udp_media_addr *remote) 243 { 244 int err = 0; 245 struct ip_mreqn mreqn; 246 struct sock *sk = ub->ubsock->sk; 247 248 if (ntohs(remote->proto) == ETH_P_IP) { 249 if (!ipv4_is_multicast(remote->ipv4.s_addr)) 250 return 0; 251 mreqn.imr_multiaddr = remote->ipv4; 252 mreqn.imr_ifindex = ub->ifindex; 253 err = ip_mc_join_group(sk, &mreqn); 254 #if IS_ENABLED(CONFIG_IPV6) 255 } else { 256 if (!ipv6_addr_is_multicast(&remote->ipv6)) 257 return 0; 258 err = ipv6_stub->ipv6_sock_mc_join(sk, ub->ifindex, 259 &remote->ipv6); 260 #endif 261 } 262 return err; 263 } 264 265 /** 266 * parse_options - build local/remote addresses from configuration 267 * @attrs: netlink config data 268 * @ub: UDP bearer instance 269 * @local: local bearer IP address/port 270 * @remote: peer or multicast IP/port 271 */ 272 static int parse_options(struct nlattr *attrs[], struct udp_bearer *ub, 273 struct udp_media_addr *local, 274 struct udp_media_addr *remote) 275 { 276 struct nlattr *opts[TIPC_NLA_UDP_MAX + 1]; 277 struct sockaddr_storage *sa_local, *sa_remote; 278 279 if (!attrs[TIPC_NLA_BEARER_UDP_OPTS]) 280 goto err; 281 if (nla_parse_nested(opts, TIPC_NLA_UDP_MAX, 282 attrs[TIPC_NLA_BEARER_UDP_OPTS], 283 tipc_nl_udp_policy)) 284 goto err; 285 if (opts[TIPC_NLA_UDP_LOCAL] && opts[TIPC_NLA_UDP_REMOTE]) { 286 sa_local = nla_data(opts[TIPC_NLA_UDP_LOCAL]); 287 sa_remote = nla_data(opts[TIPC_NLA_UDP_REMOTE]); 288 } else { 289 err: 290 pr_err("Invalid UDP bearer configuration"); 291 return -EINVAL; 292 } 293 if ((sa_local->ss_family & sa_remote->ss_family) == AF_INET) { 294 struct sockaddr_in *ip4; 295 296 ip4 = (struct sockaddr_in *)sa_local; 297 local->proto = htons(ETH_P_IP); 298 local->udp_port = ip4->sin_port; 299 local->ipv4.s_addr = ip4->sin_addr.s_addr; 300 301 ip4 = (struct sockaddr_in *)sa_remote; 302 remote->proto = htons(ETH_P_IP); 303 remote->udp_port = ip4->sin_port; 304 remote->ipv4.s_addr = ip4->sin_addr.s_addr; 305 return 0; 306 307 #if IS_ENABLED(CONFIG_IPV6) 308 } else if ((sa_local->ss_family & sa_remote->ss_family) == AF_INET6) { 309 struct sockaddr_in6 *ip6; 310 311 ip6 = (struct sockaddr_in6 *)sa_local; 312 local->proto = htons(ETH_P_IPV6); 313 local->udp_port = ip6->sin6_port; 314 local->ipv6 = ip6->sin6_addr; 315 ub->ifindex = ip6->sin6_scope_id; 316 317 ip6 = (struct sockaddr_in6 *)sa_remote; 318 remote->proto = htons(ETH_P_IPV6); 319 remote->udp_port = ip6->sin6_port; 320 remote->ipv6 = ip6->sin6_addr; 321 return 0; 322 #endif 323 } 324 return -EADDRNOTAVAIL; 325 } 326 327 /** 328 * tipc_udp_enable - callback to create a new udp bearer instance 329 * @net: network namespace 330 * @b: pointer to generic tipc_bearer 331 * @attrs: netlink bearer configuration 332 * 333 * validate the bearer parameters and initialize the udp bearer 334 * rtnl_lock should be held 335 */ 336 static int tipc_udp_enable(struct net *net, struct tipc_bearer *b, 337 struct nlattr *attrs[]) 338 { 339 int err = -EINVAL; 340 struct udp_bearer *ub; 341 struct udp_media_addr *remote; 342 struct udp_media_addr local = {0}; 343 struct udp_port_cfg udp_conf = {0}; 344 struct udp_tunnel_sock_cfg tuncfg = {NULL}; 345 346 ub = kzalloc(sizeof(*ub), GFP_ATOMIC); 347 if (!ub) 348 return -ENOMEM; 349 350 remote = (struct udp_media_addr *)&b->bcast_addr.value; 351 memset(remote, 0, sizeof(struct udp_media_addr)); 352 err = parse_options(attrs, ub, &local, remote); 353 if (err) 354 goto err; 355 356 b->bcast_addr.media_id = TIPC_MEDIA_TYPE_UDP; 357 b->bcast_addr.broadcast = 1; 358 rcu_assign_pointer(b->media_ptr, ub); 359 rcu_assign_pointer(ub->bearer, b); 360 tipc_udp_media_addr_set(&b->addr, &local); 361 if (local.proto == htons(ETH_P_IP)) { 362 struct net_device *dev; 363 364 dev = __ip_dev_find(net, local.ipv4.s_addr, false); 365 if (!dev) { 366 err = -ENODEV; 367 goto err; 368 } 369 udp_conf.family = AF_INET; 370 udp_conf.local_ip.s_addr = htonl(INADDR_ANY); 371 udp_conf.use_udp_checksums = false; 372 ub->ifindex = dev->ifindex; 373 b->mtu = dev->mtu - sizeof(struct iphdr) 374 - sizeof(struct udphdr); 375 #if IS_ENABLED(CONFIG_IPV6) 376 } else if (local.proto == htons(ETH_P_IPV6)) { 377 udp_conf.family = AF_INET6; 378 udp_conf.use_udp6_tx_checksums = true; 379 udp_conf.use_udp6_rx_checksums = true; 380 udp_conf.local_ip6 = in6addr_any; 381 b->mtu = 1280; 382 #endif 383 } else { 384 err = -EAFNOSUPPORT; 385 goto err; 386 } 387 udp_conf.local_udp_port = local.udp_port; 388 err = udp_sock_create(net, &udp_conf, &ub->ubsock); 389 if (err) 390 goto err; 391 tuncfg.sk_user_data = ub; 392 tuncfg.encap_type = 1; 393 tuncfg.encap_rcv = tipc_udp_recv; 394 tuncfg.encap_destroy = NULL; 395 setup_udp_tunnel_sock(net, ub->ubsock, &tuncfg); 396 397 if (enable_mcast(ub, remote)) 398 goto err; 399 return 0; 400 err: 401 kfree(ub); 402 return err; 403 } 404 405 /* cleanup_bearer - break the socket/bearer association */ 406 static void cleanup_bearer(struct work_struct *work) 407 { 408 struct udp_bearer *ub = container_of(work, struct udp_bearer, work); 409 410 if (ub->ubsock) 411 udp_tunnel_sock_release(ub->ubsock); 412 synchronize_net(); 413 kfree(ub); 414 } 415 416 /* tipc_udp_disable - detach bearer from socket */ 417 static void tipc_udp_disable(struct tipc_bearer *b) 418 { 419 struct udp_bearer *ub; 420 421 ub = rcu_dereference_rtnl(b->media_ptr); 422 if (!ub) { 423 pr_err("UDP bearer instance not found\n"); 424 return; 425 } 426 if (ub->ubsock) 427 sock_set_flag(ub->ubsock->sk, SOCK_DEAD); 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 }; 449