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 #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 };