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 static const struct nla_policy tipc_nl_udp_policy[TIPC_NLA_UDP_MAX + 1] = {
  57         [TIPC_NLA_UDP_UNSPEC]   = {.type = NLA_UNSPEC},
  58         [TIPC_NLA_UDP_LOCAL]    = {.type = NLA_BINARY,
  59                                    .len = sizeof(struct sockaddr_storage)},
  60         [TIPC_NLA_UDP_REMOTE]   = {.type = NLA_BINARY,
  61                                    .len = sizeof(struct sockaddr_storage)},
  62 };
  63
  64 /**
  65  * struct udp_media_addr - IP/UDP addressing information
  66  *
  67  * This is the bearer level originating address used in neighbor discovery
  68  * messages, and all fields should be in network byte order
  69  */
  70 struct udp_media_addr {
  71         __be16  proto;
  72         __be16  udp_port;
  73         union {
  74                 struct in_addr ipv4;
  75                 struct in6_addr ipv6;
  76         };
  77 };
  78
  79 /**
  80  * struct udp_bearer - ip/udp bearer data structure
  81  * @bearer:     associated generic tipc bearer
  82  * @ubsock:     bearer associated socket
  83  * @ifindex:    local address scope
  84  * @work:       used to schedule deferred work on a bearer
  85  */
  86 struct udp_bearer {
  87         struct tipc_bearer __rcu *bearer;
  88         struct socket *ubsock;
  89         u32 ifindex;
  90         struct work_struct work;
  91 };
  92
  93 /* udp_media_addr_set - convert a ip/udp address to a TIPC media address */
  94 static void tipc_udp_media_addr_set(struct tipc_media_addr *addr,
  95                                     struct udp_media_addr *ua)
  96 {
  97         memset(addr, 0, sizeof(struct tipc_media_addr));
  98         addr->media_id = TIPC_MEDIA_TYPE_UDP;
  99         memcpy(addr->value, ua, sizeof(struct udp_media_addr));
 100         if (ntohs(ua->proto) == ETH_P_IP) {
 101                 if (ipv4_is_multicast(ua->ipv4.s_addr))
 102                         addr->broadcast = 1;
 103         } else if (ntohs(ua->proto) == ETH_P_IPV6) {
 104                 if (ipv6_addr_type(&ua->ipv6) & IPV6_ADDR_MULTICAST)
 105                         addr->broadcast = 1;
 106         } else {
 107                 pr_err("Invalid UDP media address\n");
 108         }
 109 }
 110
 111 /* tipc_udp_addr2str - convert ip/udp address to string */
 112 static int tipc_udp_addr2str(struct tipc_media_addr *a, char *buf, int size)
 113 {
 114         struct udp_media_addr *ua = (struct udp_media_addr *)&a->value;
 115
 116         if (ntohs(ua->proto) == ETH_P_IP)
 117                 snprintf(buf, size, "%pI4:%u", &ua->ipv4, ntohs(ua->udp_port));
 118         else if (ntohs(ua->proto) == ETH_P_IPV6)
 119                 snprintf(buf, size, "%pI6:%u", &ua->ipv6, ntohs(ua->udp_port));
 120         else
 121                 pr_err("Invalid UDP media address\n");
 122         return 0;
 123 }
 124
 125 /* tipc_udp_msg2addr - extract an ip/udp address from a TIPC ndisc message */
 126 static int tipc_udp_msg2addr(struct tipc_bearer *b, struct tipc_media_addr *a,
 127                              char *msg)
 128 {
 129         struct udp_media_addr *ua;
 130
 131         ua = (struct udp_media_addr *) (msg + TIPC_MEDIA_ADDR_OFFSET);
 132         if (msg[TIPC_MEDIA_TYPE_OFFSET] != TIPC_MEDIA_TYPE_UDP)
 133                 return -EINVAL;
 134         tipc_udp_media_addr_set(a, ua);
 135         return 0;
 136 }
 137
 138 /* tipc_udp_addr2msg - write an ip/udp address to a TIPC ndisc message */
 139 static int tipc_udp_addr2msg(char *msg, struct tipc_media_addr *a)
 140 {
 141         memset(msg, 0, TIPC_MEDIA_INFO_SIZE);
 142         msg[TIPC_MEDIA_TYPE_OFFSET] = TIPC_MEDIA_TYPE_UDP;
 143         memcpy(msg + TIPC_MEDIA_ADDR_OFFSET, a->value,
 144                sizeof(struct udp_media_addr));
 145         return 0;
 146 }
 147
 148 /* tipc_send_msg - enqueue a send request */
 149 static int tipc_udp_send_msg(struct net *net, struct sk_buff *skb,
 150                              struct tipc_bearer *b,
 151                              struct tipc_media_addr *dest)
 152 {
 153         int ttl, err = 0;
 154         struct udp_bearer *ub;
 155         struct udp_media_addr *dst = (struct udp_media_addr *)&dest->value;
 156         struct udp_media_addr *src = (struct udp_media_addr *)&b->addr.value;
 157         struct sk_buff *clone;
 158         struct rtable *rt;
 159
 160         clone = skb_clone(skb, GFP_ATOMIC);
 161         skb_set_inner_protocol(clone, htons(ETH_P_TIPC));
 162         ub = rcu_dereference_rtnl(b->media_ptr);
 163         if (!ub) {
 164                 err = -ENODEV;
 165                 goto tx_error;
 166         }
 167         if (dst->proto == htons(ETH_P_IP)) {
 168                 struct flowi4 fl = {
 169                         .daddr = dst->ipv4.s_addr,
 170                         .saddr = src->ipv4.s_addr,
 171                         .flowi4_mark = clone->mark,
 172                         .flowi4_proto = IPPROTO_UDP
 173                 };
 174                 rt = ip_route_output_key(net, &fl);
 175                 if (IS_ERR(rt)) {
 176                         err = PTR_ERR(rt);
 177                         goto tx_error;
 178                 }
 179                 ttl = ip4_dst_hoplimit(&rt->dst);
 180                 err = udp_tunnel_xmit_skb(rt, ub->ubsock->sk, clone,
 181                                           src->ipv4.s_addr,
 182                                           dst->ipv4.s_addr, 0, ttl, 0,
 183                                           src->udp_port, dst->udp_port,
 184                                           false, true);
 185                 if (err < 0) {
 186                         ip_rt_put(rt);
 187                         goto tx_error;
 188                 }
 189 #if IS_ENABLED(CONFIG_IPV6)
 190         } else {
 191                 struct dst_entry *ndst;
 192                 struct flowi6 fl6 = {
 193                         .flowi6_oif = ub->ifindex,
 194                         .daddr = dst->ipv6,
 195                         .saddr = src->ipv6,
 196                         .flowi6_proto = IPPROTO_UDP
 197                 };
 198                 err = ipv6_stub->ipv6_dst_lookup(ub->ubsock->sk, &ndst, &fl6);
 199                 if (err)
 200                         goto tx_error;
 201                 ttl = ip6_dst_hoplimit(ndst);
 202                 err = udp_tunnel6_xmit_skb(ndst, ub->ubsock->sk, clone,
 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(clone);
 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         int usr = msg_user(buf_msg(skb));
 221
 222         if ((usr == LINK_PROTOCOL) || (usr == NAME_DISTRIBUTOR))
 223                 skb_linearize(skb);
 224
 225         ub = rcu_dereference_sk_user_data(sk);
 226         if (!ub) {
 227                 pr_err_ratelimited("Failed to get UDP bearer reference");
 228                 kfree_skb(skb);
 229                 return 0;
 230         }
 231
 232         skb_pull(skb, sizeof(struct udphdr));
 233         rcu_read_lock();
 234         b = rcu_dereference_rtnl(ub->bearer);
 235
 236         if (b) {
 237                 tipc_rcv(sock_net(sk), skb, b);
 238                 rcu_read_unlock();
 239                 return 0;
 240         }
 241         rcu_read_unlock();
 242         kfree_skb(skb);
 243         return 0;
 244 }
 245
 246 static int enable_mcast(struct udp_bearer *ub, struct udp_media_addr *remote)
 247 {
 248         int err = 0;
 249         struct ip_mreqn mreqn;
 250         struct sock *sk = ub->ubsock->sk;
 251
 252         if (ntohs(remote->proto) == ETH_P_IP) {
 253                 if (!ipv4_is_multicast(remote->ipv4.s_addr))
 254                         return 0;
 255                 mreqn.imr_multiaddr = remote->ipv4;
 256                 mreqn.imr_ifindex = ub->ifindex;
 257                 err = ip_mc_join_group(sk, &mreqn);
 258 #if IS_ENABLED(CONFIG_IPV6)
 259         } else {
 260                 if (!ipv6_addr_is_multicast(&remote->ipv6))
 261                         return 0;
 262                 err = ipv6_stub->ipv6_sock_mc_join(sk, ub->ifindex,
 263                                                    &remote->ipv6);
 264 #endif
 265         }
 266         return err;
 267 }
 268
 269 /**
 270  * parse_options - build local/remote addresses from configuration
 271  * @attrs:      netlink config data
 272  * @ub:         UDP bearer instance
 273  * @local:      local bearer IP address/port
 274  * @remote:     peer or multicast IP/port
 275  */
 276 static int parse_options(struct nlattr *attrs[], struct udp_bearer *ub,
 277                          struct udp_media_addr *local,
 278                          struct udp_media_addr *remote)
 279 {
 280         struct nlattr *opts[TIPC_NLA_UDP_MAX + 1];
 281         struct sockaddr_storage *sa_local, *sa_remote;
 282
 283         if (!attrs[TIPC_NLA_BEARER_UDP_OPTS])
 284                 goto err;
 285         if (nla_parse_nested(opts, TIPC_NLA_UDP_MAX,
 286                              attrs[TIPC_NLA_BEARER_UDP_OPTS],
 287                              tipc_nl_udp_policy))
 288                 goto err;
 289         if (opts[TIPC_NLA_UDP_LOCAL] && opts[TIPC_NLA_UDP_REMOTE]) {
 290                 sa_local = nla_data(opts[TIPC_NLA_UDP_LOCAL]);
 291                 sa_remote = nla_data(opts[TIPC_NLA_UDP_REMOTE]);
 292         } else {
 293 err:
 294                 pr_err("Invalid UDP bearer configuration");
 295                 return -EINVAL;
 296         }
 297         if ((sa_local->ss_family & sa_remote->ss_family) == AF_INET) {
 298                 struct sockaddr_in *ip4;
 299
 300                 ip4 = (struct sockaddr_in *)sa_local;
 301                 local->proto = htons(ETH_P_IP);
 302                 local->udp_port = ip4->sin_port;
 303                 local->ipv4.s_addr = ip4->sin_addr.s_addr;
 304
 305                 ip4 = (struct sockaddr_in *)sa_remote;
 306                 remote->proto = htons(ETH_P_IP);
 307                 remote->udp_port = ip4->sin_port;
 308                 remote->ipv4.s_addr = ip4->sin_addr.s_addr;
 309                 return 0;
 310
 311 #if IS_ENABLED(CONFIG_IPV6)
 312         } else if ((sa_local->ss_family & sa_remote->ss_family) == AF_INET6) {
 313                 struct sockaddr_in6 *ip6;
 314
 315                 ip6 = (struct sockaddr_in6 *)sa_local;
 316                 local->proto = htons(ETH_P_IPV6);
 317                 local->udp_port = ip6->sin6_port;
 318                 local->ipv6 = ip6->sin6_addr;
 319                 ub->ifindex = ip6->sin6_scope_id;
 320
 321                 ip6 = (struct sockaddr_in6 *)sa_remote;
 322                 remote->proto = htons(ETH_P_IPV6);
 323                 remote->udp_port = ip6->sin6_port;
 324                 remote->ipv6 = ip6->sin6_addr;
 325                 return 0;
 326 #endif
 327         }
 328         return -EADDRNOTAVAIL;
 329 }
 330
 331 /**
 332  * tipc_udp_enable - callback to create a new udp bearer instance
 333  * @net:        network namespace
 334  * @b:          pointer to generic tipc_bearer
 335  * @attrs:      netlink bearer configuration
 336  *
 337  * validate the bearer parameters and initialize the udp bearer
 338  * rtnl_lock should be held
 339  */
 340 static int tipc_udp_enable(struct net *net, struct tipc_bearer *b,
 341                            struct nlattr *attrs[])
 342 {
 343         int err = -EINVAL;
 344         struct udp_bearer *ub;
 345         struct udp_media_addr *remote;
 346         struct udp_media_addr local = {0};
 347         struct udp_port_cfg udp_conf = {0};
 348         struct udp_tunnel_sock_cfg tuncfg = {NULL};
 349
 350         ub = kzalloc(sizeof(*ub), GFP_ATOMIC);
 351         if (!ub)
 352                 return -ENOMEM;
 353
 354         remote = (struct udp_media_addr *)&b->bcast_addr.value;
 355         memset(remote, 0, sizeof(struct udp_media_addr));
 356         err = parse_options(attrs, ub, &local, remote);
 357         if (err)
 358                 goto err;
 359
 360         b->bcast_addr.media_id = TIPC_MEDIA_TYPE_UDP;
 361         b->bcast_addr.broadcast = 1;
 362         rcu_assign_pointer(b->media_ptr, ub);
 363         rcu_assign_pointer(ub->bearer, b);
 364         tipc_udp_media_addr_set(&b->addr, &local);
 365         if (local.proto == htons(ETH_P_IP)) {
 366                 struct net_device *dev;
 367
 368                 dev = __ip_dev_find(net, local.ipv4.s_addr, false);
 369                 if (!dev) {
 370                         err = -ENODEV;
 371                         goto err;
 372                 }
 373                 udp_conf.family = AF_INET;
 374                 udp_conf.local_ip.s_addr = htonl(INADDR_ANY);
 375                 udp_conf.use_udp_checksums = false;
 376                 ub->ifindex = dev->ifindex;
 377                 b->mtu = dev->mtu - sizeof(struct iphdr)
 378                         - sizeof(struct udphdr);
 379 #if IS_ENABLED(CONFIG_IPV6)
 380         } else if (local.proto == htons(ETH_P_IPV6)) {
 381                 udp_conf.family = AF_INET6;
 382                 udp_conf.use_udp6_tx_checksums = true;
 383                 udp_conf.use_udp6_rx_checksums = true;
 384                 udp_conf.local_ip6 = in6addr_any;
 385                 b->mtu = 1280;
 386 #endif
 387         } else {
 388                 err = -EAFNOSUPPORT;
 389                 goto err;
 390         }
 391         udp_conf.local_udp_port = local.udp_port;
 392         err = udp_sock_create(net, &udp_conf, &ub->ubsock);
 393         if (err)
 394                 goto err;
 395         tuncfg.sk_user_data = ub;
 396         tuncfg.encap_type = 1;
 397         tuncfg.encap_rcv = tipc_udp_recv;
 398         tuncfg.encap_destroy = NULL;
 399         setup_udp_tunnel_sock(net, ub->ubsock, &tuncfg);
 400
 401         if (enable_mcast(ub, remote))
 402                 goto err;
 403         return 0;
 404 err:
 405         kfree(ub);
 406         return err;
 407 }
 408
 409 /* cleanup_bearer - break the socket/bearer association */
 410 static void cleanup_bearer(struct work_struct *work)
 411 {
 412         struct udp_bearer *ub = container_of(work, struct udp_bearer, work);
 413
 414         if (ub->ubsock)
 415                 udp_tunnel_sock_release(ub->ubsock);
 416         synchronize_net();
 417         kfree(ub);
 418 }
 419
 420 /* tipc_udp_disable - detach bearer from socket */
 421 static void tipc_udp_disable(struct tipc_bearer *b)
 422 {
 423         struct udp_bearer *ub;
 424
 425         ub = rcu_dereference_rtnl(b->media_ptr);
 426         if (!ub) {
 427                 pr_err("UDP bearer instance not found\n");
 428                 return;
 429         }
 430         if (ub->ubsock)
 431                 sock_set_flag(ub->ubsock->sk, SOCK_DEAD);
 432         RCU_INIT_POINTER(b->media_ptr, NULL);
 433         RCU_INIT_POINTER(ub->bearer, NULL);
 434
 435         /* sock_release need to be done outside of rtnl lock */
 436         INIT_WORK(&ub->work, cleanup_bearer);
 437         schedule_work(&ub->work);
 438 }
 439
 440 struct tipc_media udp_media_info = {
 441         .send_msg       = tipc_udp_send_msg,
 442         .enable_media   = tipc_udp_enable,
 443         .disable_media  = tipc_udp_disable,
 444         .addr2str       = tipc_udp_addr2str,
 445         .addr2msg       = tipc_udp_addr2msg,
 446         .msg2addr       = tipc_udp_msg2addr,
 447         .priority       = TIPC_DEF_LINK_PRI,
 448         .tolerance      = TIPC_DEF_LINK_TOL,
 449         .window         = TIPC_DEF_LINK_WIN,
 450         .type_id        = TIPC_MEDIA_TYPE_UDP,
 451         .hwaddr_len     = 0,
 452         .name           = "udp"
 453 };