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
  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 };