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 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 };