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 "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  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->port));
 112         else if (ntohs(ua->proto) == ETH_P_IPV6)
 113                 snprintf(buf, size, "%pI6:%u", &ua->ipv6, ntohs(ua->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->port,
 182                                     dst->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->port,
 200                                            dst->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->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->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->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->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.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 };