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 "netlink.h" 52 53 /* IANA assigned UDP port */ 54 #define UDP_PORT_DEFAULT 6118 55 56 #define UDP_MIN_HEADROOM 48 57 58 /** 59 * struct udp_media_addr - IP/UDP addressing information 60 * 61 * This is the bearer level originating address used in neighbor discovery 62 * messages, and all fields should be in network byte order 63 */ 64 struct udp_media_addr { 65 __be16 proto; 66 __be16 udp_port; 67 union { 68 struct in_addr ipv4; 69 struct in6_addr ipv6; 70 }; 71 }; 72 73 /** 74 * struct udp_bearer - ip/udp bearer data structure 75 * @bearer: associated generic tipc bearer 76 * @ubsock: bearer associated socket 77 * @ifindex: local address scope 78 * @work: used to schedule deferred work on a bearer 79 */ 80 struct udp_bearer { 81 struct tipc_bearer __rcu *bearer; 82 struct socket *ubsock; 83 u32 ifindex; 84 struct work_struct work; 85 }; 86 87 /* udp_media_addr_set - convert a ip/udp address to a TIPC media address */ 88 static void tipc_udp_media_addr_set(struct tipc_media_addr *addr, 89 struct udp_media_addr *ua) 90 { 91 memset(addr, 0, sizeof(struct tipc_media_addr)); 92 addr->media_id = TIPC_MEDIA_TYPE_UDP; 93 memcpy(addr->value, ua, sizeof(struct udp_media_addr)); 94 if (ntohs(ua->proto) == ETH_P_IP) { 95 if (ipv4_is_multicast(ua->ipv4.s_addr)) 96 addr->broadcast = 1; 97 } else if (ntohs(ua->proto) == ETH_P_IPV6) { 98 if (ipv6_addr_type(&ua->ipv6) & IPV6_ADDR_MULTICAST) 99 addr->broadcast = 1; 100 } else { 101 pr_err("Invalid UDP media address\n"); 102 } 103 } 104 105 /* tipc_udp_addr2str - convert ip/udp address to string */ 106 static int tipc_udp_addr2str(struct tipc_media_addr *a, char *buf, int size) 107 { 108 struct udp_media_addr *ua = (struct udp_media_addr *)&a->value; 109 110 if (ntohs(ua->proto) == ETH_P_IP) 111 snprintf(buf, size, "%pI4:%u", &ua->ipv4, ntohs(ua->udp_port)); 112 else if (ntohs(ua->proto) == ETH_P_IPV6) 113 snprintf(buf, size, "%pI6:%u", &ua->ipv6, ntohs(ua->udp_port)); 114 else 115 pr_err("Invalid UDP media address\n"); 116 return 0; 117 } 118 119 /* tipc_udp_msg2addr - extract an ip/udp address from a TIPC ndisc message */ 120 static int tipc_udp_msg2addr(struct tipc_bearer *b, struct tipc_media_addr *a, 121 char *msg) 122 { 123 struct udp_media_addr *ua; 124 125 ua = (struct udp_media_addr *) (msg + TIPC_MEDIA_ADDR_OFFSET); 126 if (msg[TIPC_MEDIA_TYPE_OFFSET] != TIPC_MEDIA_TYPE_UDP) 127 return -EINVAL; 128 tipc_udp_media_addr_set(a, ua); 129 return 0; 130 } 131 132 /* tipc_udp_addr2msg - write an ip/udp address to a TIPC ndisc message */ 133 static int tipc_udp_addr2msg(char *msg, struct tipc_media_addr *a) 134 { 135 memset(msg, 0, TIPC_MEDIA_INFO_SIZE); 136 msg[TIPC_MEDIA_TYPE_OFFSET] = TIPC_MEDIA_TYPE_UDP; 137 memcpy(msg + TIPC_MEDIA_ADDR_OFFSET, a->value, 138 sizeof(struct udp_media_addr)); 139 return 0; 140 } 141 142 /* tipc_send_msg - enqueue a send request */ 143 static int tipc_udp_send_msg(struct net *net, struct sk_buff *skb, 144 struct tipc_bearer *b, 145 struct tipc_media_addr *dest) 146 { 147 int ttl, err = 0; 148 struct udp_bearer *ub; 149 struct udp_media_addr *dst = (struct udp_media_addr *)&dest->value; 150 struct udp_media_addr *src = (struct udp_media_addr *)&b->addr.value; 151 struct rtable *rt; 152 153 if (skb_headroom(skb) < UDP_MIN_HEADROOM) { 154 err = pskb_expand_head(skb, UDP_MIN_HEADROOM, 0, GFP_ATOMIC); 155 if (err) 156 goto tx_error; 157 } 158 159 skb_set_inner_protocol(skb, htons(ETH_P_TIPC)); 160 ub = rcu_dereference_rtnl(b->media_ptr); 161 if (!ub) { 162 err = -ENODEV; 163 goto tx_error; 164 } 165 if (dst->proto == htons(ETH_P_IP)) { 166 struct flowi4 fl = { 167 .daddr = dst->ipv4.s_addr, 168 .saddr = src->ipv4.s_addr, 169 .flowi4_mark = skb->mark, 170 .flowi4_proto = IPPROTO_UDP 171 }; 172 rt = ip_route_output_key(net, &fl); 173 if (IS_ERR(rt)) { 174 err = PTR_ERR(rt); 175 goto tx_error; 176 } 177 178 skb->dev = rt->dst.dev; 179 ttl = ip4_dst_hoplimit(&rt->dst); 180 udp_tunnel_xmit_skb(rt, ub->ubsock->sk, skb, src->ipv4.s_addr, 181 dst->ipv4.s_addr, 0, ttl, 0, src->udp_port, 182 dst->udp_port, false, true); 183 #if IS_ENABLED(CONFIG_IPV6) 184 } else { 185 struct dst_entry *ndst; 186 struct flowi6 fl6 = { 187 .flowi6_oif = ub->ifindex, 188 .daddr = dst->ipv6, 189 .saddr = src->ipv6, 190 .flowi6_proto = IPPROTO_UDP 191 }; 192 err = ipv6_stub->ipv6_dst_lookup(net, ub->ubsock->sk, &ndst, 193 &fl6); 194 if (err) 195 goto tx_error; 196 ttl = ip6_dst_hoplimit(ndst); 197 err = udp_tunnel6_xmit_skb(ndst, ub->ubsock->sk, skb, 198 ndst->dev, &src->ipv6, 199 &dst->ipv6, 0, ttl, 0, src->udp_port, 200 dst->udp_port, false); 201 #endif 202 } 203 return err; 204 205 tx_error: 206 kfree_skb(skb); 207 return err; 208 } 209 210 /* tipc_udp_recv - read data from bearer socket */ 211 static int tipc_udp_recv(struct sock *sk, struct sk_buff *skb) 212 { 213 struct udp_bearer *ub; 214 struct tipc_bearer *b; 215 216 ub = rcu_dereference_sk_user_data(sk); 217 if (!ub) { 218 pr_err_ratelimited("Failed to get UDP bearer reference"); 219 kfree_skb(skb); 220 return 0; 221 } 222 223 skb_pull(skb, sizeof(struct udphdr)); 224 rcu_read_lock(); 225 b = rcu_dereference_rtnl(ub->bearer); 226 227 if (b) { 228 tipc_rcv(sock_net(sk), skb, b); 229 rcu_read_unlock(); 230 return 0; 231 } 232 rcu_read_unlock(); 233 kfree_skb(skb); 234 return 0; 235 } 236 237 static int enable_mcast(struct udp_bearer *ub, struct udp_media_addr *remote) 238 { 239 int err = 0; 240 struct ip_mreqn mreqn; 241 struct sock *sk = ub->ubsock->sk; 242 243 if (ntohs(remote->proto) == ETH_P_IP) { 244 if (!ipv4_is_multicast(remote->ipv4.s_addr)) 245 return 0; 246 mreqn.imr_multiaddr = remote->ipv4; 247 mreqn.imr_ifindex = ub->ifindex; 248 err = ip_mc_join_group(sk, &mreqn); 249 #if IS_ENABLED(CONFIG_IPV6) 250 } else { 251 if (!ipv6_addr_is_multicast(&remote->ipv6)) 252 return 0; 253 err = ipv6_stub->ipv6_sock_mc_join(sk, ub->ifindex, 254 &remote->ipv6); 255 #endif 256 } 257 return err; 258 } 259 260 /** 261 * parse_options - build local/remote addresses from configuration 262 * @attrs: netlink config data 263 * @ub: UDP bearer instance 264 * @local: local bearer IP address/port 265 * @remote: peer or multicast IP/port 266 */ 267 static int parse_options(struct nlattr *attrs[], struct udp_bearer *ub, 268 struct udp_media_addr *local, 269 struct udp_media_addr *remote) 270 { 271 struct nlattr *opts[TIPC_NLA_UDP_MAX + 1]; 272 struct sockaddr_storage sa_local, sa_remote; 273 274 if (!attrs[TIPC_NLA_BEARER_UDP_OPTS]) 275 goto err; 276 if (nla_parse_nested(opts, TIPC_NLA_UDP_MAX, 277 attrs[TIPC_NLA_BEARER_UDP_OPTS], 278 tipc_nl_udp_policy)) 279 goto err; 280 if (opts[TIPC_NLA_UDP_LOCAL] && opts[TIPC_NLA_UDP_REMOTE]) { 281 nla_memcpy(&sa_local, opts[TIPC_NLA_UDP_LOCAL], 282 sizeof(sa_local)); 283 nla_memcpy(&sa_remote, opts[TIPC_NLA_UDP_REMOTE], 284 sizeof(sa_remote)); 285 } else { 286 err: 287 pr_err("Invalid UDP bearer configuration"); 288 return -EINVAL; 289 } 290 if ((sa_local.ss_family & sa_remote.ss_family) == AF_INET) { 291 struct sockaddr_in *ip4; 292 293 ip4 = (struct sockaddr_in *)&sa_local; 294 local->proto = htons(ETH_P_IP); 295 local->udp_port = ip4->sin_port; 296 local->ipv4.s_addr = ip4->sin_addr.s_addr; 297 298 ip4 = (struct sockaddr_in *)&sa_remote; 299 remote->proto = htons(ETH_P_IP); 300 remote->udp_port = ip4->sin_port; 301 remote->ipv4.s_addr = ip4->sin_addr.s_addr; 302 return 0; 303 304 #if IS_ENABLED(CONFIG_IPV6) 305 } else if ((sa_local.ss_family & sa_remote.ss_family) == AF_INET6) { 306 int atype; 307 struct sockaddr_in6 *ip6; 308 309 ip6 = (struct sockaddr_in6 *)&sa_local; 310 atype = ipv6_addr_type(&ip6->sin6_addr); 311 if (__ipv6_addr_needs_scope_id(atype) && !ip6->sin6_scope_id) 312 return -EINVAL; 313 314 local->proto = htons(ETH_P_IPV6); 315 local->udp_port = ip6->sin6_port; 316 memcpy(&local->ipv6, &ip6->sin6_addr, sizeof(struct in6_addr)); 317 ub->ifindex = ip6->sin6_scope_id; 318 319 ip6 = (struct sockaddr_in6 *)&sa_remote; 320 remote->proto = htons(ETH_P_IPV6); 321 remote->udp_port = ip6->sin6_port; 322 memcpy(&remote->ipv6, &ip6->sin6_addr, sizeof(struct in6_addr)); 323 return 0; 324 #endif 325 } 326 return -EADDRNOTAVAIL; 327 } 328 329 /** 330 * tipc_udp_enable - callback to create a new udp bearer instance 331 * @net: network namespace 332 * @b: pointer to generic tipc_bearer 333 * @attrs: netlink bearer configuration 334 * 335 * validate the bearer parameters and initialize the udp bearer 336 * rtnl_lock should be held 337 */ 338 static int tipc_udp_enable(struct net *net, struct tipc_bearer *b, 339 struct nlattr *attrs[]) 340 { 341 int err = -EINVAL; 342 struct udp_bearer *ub; 343 struct udp_media_addr *remote; 344 struct udp_media_addr local = {0}; 345 struct udp_port_cfg udp_conf = {0}; 346 struct udp_tunnel_sock_cfg tuncfg = {NULL}; 347 348 ub = kzalloc(sizeof(*ub), GFP_ATOMIC); 349 if (!ub) 350 return -ENOMEM; 351 352 remote = (struct udp_media_addr *)&b->bcast_addr.value; 353 memset(remote, 0, sizeof(struct udp_media_addr)); 354 err = parse_options(attrs, ub, &local, remote); 355 if (err) 356 goto err; 357 358 b->bcast_addr.media_id = TIPC_MEDIA_TYPE_UDP; 359 b->bcast_addr.broadcast = 1; 360 rcu_assign_pointer(b->media_ptr, ub); 361 rcu_assign_pointer(ub->bearer, b); 362 tipc_udp_media_addr_set(&b->addr, &local); 363 if (local.proto == htons(ETH_P_IP)) { 364 struct net_device *dev; 365 366 dev = __ip_dev_find(net, local.ipv4.s_addr, false); 367 if (!dev) { 368 err = -ENODEV; 369 goto err; 370 } 371 udp_conf.family = AF_INET; 372 udp_conf.local_ip.s_addr = htonl(INADDR_ANY); 373 udp_conf.use_udp_checksums = false; 374 ub->ifindex = dev->ifindex; 375 b->mtu = dev->mtu - sizeof(struct iphdr) 376 - sizeof(struct udphdr); 377 #if IS_ENABLED(CONFIG_IPV6) 378 } else if (local.proto == htons(ETH_P_IPV6)) { 379 udp_conf.family = AF_INET6; 380 udp_conf.use_udp6_tx_checksums = true; 381 udp_conf.use_udp6_rx_checksums = true; 382 udp_conf.local_ip6 = in6addr_any; 383 b->mtu = 1280; 384 #endif 385 } else { 386 err = -EAFNOSUPPORT; 387 goto err; 388 } 389 udp_conf.local_udp_port = local.udp_port; 390 err = udp_sock_create(net, &udp_conf, &ub->ubsock); 391 if (err) 392 goto err; 393 tuncfg.sk_user_data = ub; 394 tuncfg.encap_type = 1; 395 tuncfg.encap_rcv = tipc_udp_recv; 396 tuncfg.encap_destroy = NULL; 397 setup_udp_tunnel_sock(net, ub->ubsock, &tuncfg); 398 399 if (enable_mcast(ub, remote)) 400 goto err; 401 return 0; 402 err: 403 kfree(ub); 404 return err; 405 } 406 407 /* cleanup_bearer - break the socket/bearer association */ 408 static void cleanup_bearer(struct work_struct *work) 409 { 410 struct udp_bearer *ub = container_of(work, struct udp_bearer, work); 411 412 if (ub->ubsock) 413 udp_tunnel_sock_release(ub->ubsock); 414 synchronize_net(); 415 kfree(ub); 416 } 417 418 /* tipc_udp_disable - detach bearer from socket */ 419 static void tipc_udp_disable(struct tipc_bearer *b) 420 { 421 struct udp_bearer *ub; 422 423 ub = rcu_dereference_rtnl(b->media_ptr); 424 if (!ub) { 425 pr_err("UDP bearer instance not found\n"); 426 return; 427 } 428 if (ub->ubsock) 429 sock_set_flag(ub->ubsock->sk, SOCK_DEAD); 430 RCU_INIT_POINTER(ub->bearer, NULL); 431 432 /* sock_release need to be done outside of rtnl lock */ 433 INIT_WORK(&ub->work, cleanup_bearer); 434 schedule_work(&ub->work); 435 } 436 437 struct tipc_media udp_media_info = { 438 .send_msg = tipc_udp_send_msg, 439 .enable_media = tipc_udp_enable, 440 .disable_media = tipc_udp_disable, 441 .addr2str = tipc_udp_addr2str, 442 .addr2msg = tipc_udp_addr2msg, 443 .msg2addr = tipc_udp_msg2addr, 444 .priority = TIPC_DEF_LINK_PRI, 445 .tolerance = TIPC_DEF_LINK_TOL, 446 .window = TIPC_DEF_LINK_WIN, 447 .type_id = TIPC_MEDIA_TYPE_UDP, 448 .hwaddr_len = 0, 449 .name = "udp" 450 }; 451