net/l2tp/l2tp_ip.c

   1 /*
   2  * L2TPv3 IP encapsulation support
   3  *
   4  * Copyright (c) 2008,2009,2010 Katalix Systems Ltd
   5  *
   6  *      This program is free software; you can redistribute it and/or
   7  *      modify it under the terms of the GNU General Public License
   8  *      as published by the Free Software Foundation; either version
   9  *      2 of the License, or (at your option) any later version.
  10  */
  11
  12 #include <linux/icmp.h>
  13 #include <linux/module.h>
  14 #include <linux/skbuff.h>
  15 #include <linux/random.h>
  16 #include <linux/socket.h>
  17 #include <linux/l2tp.h>
  18 #include <linux/in.h>
  19 #include <net/sock.h>
  20 #include <net/ip.h>
  21 #include <net/icmp.h>
  22 #include <net/udp.h>
  23 #include <net/inet_common.h>
  24 #include <net/inet_hashtables.h>
  25 #include <net/tcp_states.h>
  26 #include <net/protocol.h>
  27 #include <net/xfrm.h>
  28
  29 #include "l2tp_core.h"
  30
  31 struct l2tp_ip_sock {
  32         /* inet_sock has to be the first member of l2tp_ip_sock */
  33         struct inet_sock        inet;
  34
  35         __u32                   conn_id;
  36         __u32                   peer_conn_id;
  37
  38         __u64                   tx_packets;
  39         __u64                   tx_bytes;
  40         __u64                   tx_errors;
  41         __u64                   rx_packets;
  42         __u64                   rx_bytes;
  43         __u64                   rx_errors;
  44 };
  45
  46 static DEFINE_RWLOCK(l2tp_ip_lock);
  47 static struct hlist_head l2tp_ip_table;
  48 static struct hlist_head l2tp_ip_bind_table;
  49
  50 static inline struct l2tp_ip_sock *l2tp_ip_sk(const struct sock *sk)
  51 {
  52         return (struct l2tp_ip_sock *)sk;
  53 }
  54
  55 static struct sock *__l2tp_ip_bind_lookup(struct net *net, __be32 laddr, int dif, u32 tunnel_id)
  56 {
  57         struct hlist_node *node;
  58         struct sock *sk;
  59
  60         sk_for_each_bound(sk, node, &l2tp_ip_bind_table) {
  61                 struct inet_sock *inet = inet_sk(sk);
  62                 struct l2tp_ip_sock *l2tp = l2tp_ip_sk(sk);
  63
  64                 if (l2tp == NULL)
  65                         continue;
  66
  67                 if ((l2tp->conn_id == tunnel_id) &&
  68 #ifdef CONFIG_NET_NS
  69                     (sk->sk_net == net) &&
  70 #endif
  71                     !(inet->inet_rcv_saddr && inet->inet_rcv_saddr != laddr) &&
  72                     !(sk->sk_bound_dev_if && sk->sk_bound_dev_if != dif))
  73                         goto found;
  74         }
  75
  76         sk = NULL;
  77 found:
  78         return sk;
  79 }
  80
  81 static inline struct sock *l2tp_ip_bind_lookup(struct net *net, __be32 laddr, int dif, u32 tunnel_id)
  82 {
  83         struct sock *sk = __l2tp_ip_bind_lookup(net, laddr, dif, tunnel_id);
  84         if (sk)
  85                 sock_hold(sk);
  86
  87         return sk;
  88 }
  89
  90 /* When processing receive frames, there are two cases to
  91  * consider. Data frames consist of a non-zero session-id and an
  92  * optional cookie. Control frames consist of a regular L2TP header
  93  * preceded by 32-bits of zeros.
  94  *
  95  * L2TPv3 Session Header Over IP
  96  *
  97  *  0                   1                   2                   3
  98  *  0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
  99  * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 100  * |                           Session ID                          |
 101  * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 102  * |               Cookie (optional, maximum 64 bits)...
 103  * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 104  *                                                                 |
 105  * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 106  *
 107  * L2TPv3 Control Message Header Over IP
 108  *
 109  *  0                   1                   2                   3
 110  *  0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
 111  * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 112  * |                      (32 bits of zeros)                       |
 113  * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 114  * |T|L|x|x|S|x|x|x|x|x|x|x|  Ver  |             Length            |
 115  * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 116  * |                     Control Connection ID                     |
 117  * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 118  * |               Ns              |               Nr              |
 119  * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 120  *
 121  * All control frames are passed to userspace.
 122  */
 123 static int l2tp_ip_recv(struct sk_buff *skb)
 124 {
 125         struct sock *sk;
 126         u32 session_id;
 127         u32 tunnel_id;
 128         unsigned char *ptr, *optr;
 129         struct l2tp_session *session;
 130         struct l2tp_tunnel *tunnel = NULL;
 131         int length;
 132         int offset;
 133
 134         /* Point to L2TP header */
 135         optr = ptr = skb->data;
 136
 137         if (!pskb_may_pull(skb, 4))
 138                 goto discard;
 139
 140         session_id = ntohl(*((__be32 *) ptr));
 141         ptr += 4;
 142
 143         /* RFC3931: L2TP/IP packets have the first 4 bytes containing
 144          * the session_id. If it is 0, the packet is a L2TP control
 145          * frame and the session_id value can be discarded.
 146          */
 147         if (session_id == 0) {
 148                 __skb_pull(skb, 4);
 149                 goto pass_up;
 150         }
 151
 152         /* Ok, this is a data packet. Lookup the session. */
 153         session = l2tp_session_find(&init_net, NULL, session_id);
 154         if (session == NULL)
 155                 goto discard;
 156
 157         tunnel = session->tunnel;
 158         if (tunnel == NULL)
 159                 goto discard;
 160
 161         /* Trace packet contents, if enabled */
 162         if (tunnel->debug & L2TP_MSG_DATA) {
 163                 length = min(32u, skb->len);
 164                 if (!pskb_may_pull(skb, length))
 165                         goto discard;
 166
 167                 printk(KERN_DEBUG "%s: ip recv: ", tunnel->name);
 168
 169                 offset = 0;
 170                 do {
 171                         printk(" %02X", ptr[offset]);
 172                 } while (++offset < length);
 173
 174                 printk("\n");
 175         }
 176
 177         l2tp_recv_common(session, skb, ptr, optr, 0, skb->len, tunnel->recv_payload_hook);
 178
 179         return 0;
 180
 181 pass_up:
 182         /* Get the tunnel_id from the L2TP header */
 183         if (!pskb_may_pull(skb, 12))
 184                 goto discard;
 185
 186         if ((skb->data[0] & 0xc0) != 0xc0)
 187                 goto discard;
 188
 189         tunnel_id = ntohl(*(__be32 *) &skb->data[4]);
 190         tunnel = l2tp_tunnel_find(&init_net, tunnel_id);
 191         if (tunnel != NULL)
 192                 sk = tunnel->sock;
 193         else {
 194                 struct iphdr *iph = (struct iphdr *) skb_network_header(skb);
 195
 196                 read_lock_bh(&l2tp_ip_lock);
 197                 sk = __l2tp_ip_bind_lookup(&init_net, iph->daddr, 0, tunnel_id);
 198                 read_unlock_bh(&l2tp_ip_lock);
 199         }
 200
 201         if (sk == NULL)
 202                 goto discard;
 203
 204         sock_hold(sk);
 205
 206         if (!xfrm4_policy_check(sk, XFRM_POLICY_IN, skb))
 207                 goto discard_put;
 208
 209         nf_reset(skb);
 210
 211         return sk_receive_skb(sk, skb, 1);
 212
 213 discard_put:
 214         sock_put(sk);
 215
 216 discard:
 217         kfree_skb(skb);
 218         return 0;
 219 }
 220
 221 static int l2tp_ip_open(struct sock *sk)
 222 {
 223         /* Prevent autobind. We don't have ports. */
 224         inet_sk(sk)->inet_num = IPPROTO_L2TP;
 225
 226         write_lock_bh(&l2tp_ip_lock);
 227         sk_add_node(sk, &l2tp_ip_table);
 228         write_unlock_bh(&l2tp_ip_lock);
 229
 230         return 0;
 231 }
 232
 233 static void l2tp_ip_close(struct sock *sk, long timeout)
 234 {
 235         write_lock_bh(&l2tp_ip_lock);
 236         hlist_del_init(&sk->sk_bind_node);
 237         hlist_del_init(&sk->sk_node);
 238         write_unlock_bh(&l2tp_ip_lock);
 239         sk_common_release(sk);
 240 }
 241
 242 static void l2tp_ip_destroy_sock(struct sock *sk)
 243 {
 244         struct sk_buff *skb;
 245
 246         while ((skb = __skb_dequeue_tail(&sk->sk_write_queue)) != NULL)
 247                 kfree_skb(skb);
 248
 249         sk_refcnt_debug_dec(sk);
 250 }
 251
 252 static int l2tp_ip_bind(struct sock *sk, struct sockaddr *uaddr, int addr_len)
 253 {
 254         struct inet_sock *inet = inet_sk(sk);
 255         struct sockaddr_l2tpip *addr = (struct sockaddr_l2tpip *) uaddr;
 256         int ret = -EINVAL;
 257         int chk_addr_ret;
 258
 259         ret = -EADDRINUSE;
 260         read_lock_bh(&l2tp_ip_lock);
 261         if (__l2tp_ip_bind_lookup(&init_net, addr->l2tp_addr.s_addr, sk->sk_bound_dev_if, addr->l2tp_conn_id))
 262                 goto out_in_use;
 263
 264         read_unlock_bh(&l2tp_ip_lock);
 265
 266         lock_sock(sk);
 267         if (sk->sk_state != TCP_CLOSE || addr_len < sizeof(struct sockaddr_l2tpip))
 268                 goto out;
 269
 270         chk_addr_ret = inet_addr_type(&init_net, addr->l2tp_addr.s_addr);
 271         ret = -EADDRNOTAVAIL;
 272         if (addr->l2tp_addr.s_addr && chk_addr_ret != RTN_LOCAL &&
 273             chk_addr_ret != RTN_MULTICAST && chk_addr_ret != RTN_BROADCAST)
 274                 goto out;
 275
 276         inet->inet_rcv_saddr = inet->inet_saddr = addr->l2tp_addr.s_addr;
 277         if (chk_addr_ret == RTN_MULTICAST || chk_addr_ret == RTN_BROADCAST)
 278                 inet->inet_saddr = 0;  /* Use device */
 279         sk_dst_reset(sk);
 280
 281         l2tp_ip_sk(sk)->conn_id = addr->l2tp_conn_id;
 282
 283         write_lock_bh(&l2tp_ip_lock);
 284         sk_add_bind_node(sk, &l2tp_ip_bind_table);
 285         sk_del_node_init(sk);
 286         write_unlock_bh(&l2tp_ip_lock);
 287         ret = 0;
 288 out:
 289         release_sock(sk);
 290
 291         return ret;
 292
 293 out_in_use:
 294         read_unlock_bh(&l2tp_ip_lock);
 295
 296         return ret;
 297 }
 298
 299 static int l2tp_ip_connect(struct sock *sk, struct sockaddr *uaddr, int addr_len)
 300 {
 301         int rc;
 302         struct inet_sock *inet = inet_sk(sk);
 303         struct sockaddr_l2tpip *lsa = (struct sockaddr_l2tpip *) uaddr;
 304         struct rtable *rt;
 305         __be32 saddr;
 306         int oif;
 307
 308         rc = -EINVAL;
 309         if (addr_len < sizeof(*lsa))
 310                 goto out;
 311
 312         rc = -EAFNOSUPPORT;
 313         if (lsa->l2tp_family != AF_INET)
 314                 goto out;
 315
 316         sk_dst_reset(sk);
 317
 318         oif = sk->sk_bound_dev_if;
 319         saddr = inet->inet_saddr;
 320
 321         rc = -EINVAL;
 322         if (ipv4_is_multicast(lsa->l2tp_addr.s_addr))
 323                 goto out;
 324
 325         rc = ip_route_connect(&rt, lsa->l2tp_addr.s_addr, saddr,
 326                               RT_CONN_FLAGS(sk), oif,
 327                               IPPROTO_L2TP,
 328                               0, 0, sk, 1);
 329         if (rc) {
 330                 if (rc == -ENETUNREACH)
 331                         IP_INC_STATS_BH(&init_net, IPSTATS_MIB_OUTNOROUTES);
 332                 goto out;
 333         }
 334
 335         rc = -ENETUNREACH;
 336         if (rt->rt_flags & (RTCF_MULTICAST | RTCF_BROADCAST)) {
 337                 ip_rt_put(rt);
 338                 goto out;
 339         }
 340
 341         l2tp_ip_sk(sk)->peer_conn_id = lsa->l2tp_conn_id;
 342
 343         if (!inet->inet_saddr)
 344                 inet->inet_saddr = rt->rt_src;
 345         if (!inet->inet_rcv_saddr)
 346                 inet->inet_rcv_saddr = rt->rt_src;
 347         inet->inet_daddr = rt->rt_dst;
 348         sk->sk_state = TCP_ESTABLISHED;
 349         inet->inet_id = jiffies;
 350
 351         sk_dst_set(sk, &rt->dst);
 352
 353         write_lock_bh(&l2tp_ip_lock);
 354         hlist_del_init(&sk->sk_bind_node);
 355         sk_add_bind_node(sk, &l2tp_ip_bind_table);
 356         write_unlock_bh(&l2tp_ip_lock);
 357
 358         rc = 0;
 359 out:
 360         return rc;
 361 }
 362
 363 static int l2tp_ip_getname(struct socket *sock, struct sockaddr *uaddr,
 364                            int *uaddr_len, int peer)
 365 {
 366         struct sock *sk         = sock->sk;
 367         struct inet_sock *inet  = inet_sk(sk);
 368         struct l2tp_ip_sock *lsk = l2tp_ip_sk(sk);
 369         struct sockaddr_l2tpip *lsa = (struct sockaddr_l2tpip *)uaddr;
 370
 371         memset(lsa, 0, sizeof(*lsa));
 372         lsa->l2tp_family = AF_INET;
 373         if (peer) {
 374                 if (!inet->inet_dport)
 375                         return -ENOTCONN;
 376                 lsa->l2tp_conn_id = lsk->peer_conn_id;
 377                 lsa->l2tp_addr.s_addr = inet->inet_daddr;
 378         } else {
 379                 __be32 addr = inet->inet_rcv_saddr;
 380                 if (!addr)
 381                         addr = inet->inet_saddr;
 382                 lsa->l2tp_conn_id = lsk->conn_id;
 383                 lsa->l2tp_addr.s_addr = addr;
 384         }
 385         *uaddr_len = sizeof(*lsa);
 386         return 0;
 387 }
 388
 389 static int l2tp_ip_backlog_recv(struct sock *sk, struct sk_buff *skb)
 390 {
 391         int rc;
 392
 393         if (!xfrm4_policy_check(sk, XFRM_POLICY_IN, skb))
 394                 goto drop;
 395
 396         nf_reset(skb);
 397
 398         /* Charge it to the socket, dropping if the queue is full. */
 399         rc = sock_queue_rcv_skb(sk, skb);
 400         if (rc < 0)
 401                 goto drop;
 402
 403         return 0;
 404
 405 drop:
 406         IP_INC_STATS(&init_net, IPSTATS_MIB_INDISCARDS);
 407         kfree_skb(skb);
 408         return -1;
 409 }
 410
 411 /* Userspace will call sendmsg() on the tunnel socket to send L2TP
 412  * control frames.
 413  */
 414 static int l2tp_ip_sendmsg(struct kiocb *iocb, struct sock *sk, struct msghdr *msg, size_t len)
 415 {
 416         struct sk_buff *skb;
 417         int rc;
 418         struct l2tp_ip_sock *lsa = l2tp_ip_sk(sk);
 419         struct inet_sock *inet = inet_sk(sk);
 420         struct ip_options *opt = inet->opt;
 421         struct rtable *rt = NULL;
 422         int connected = 0;
 423         __be32 daddr;
 424
 425         if (sock_flag(sk, SOCK_DEAD))
 426                 return -ENOTCONN;
 427
 428         /* Get and verify the address. */
 429         if (msg->msg_name) {
 430                 struct sockaddr_l2tpip *lip = (struct sockaddr_l2tpip *) msg->msg_name;
 431                 if (msg->msg_namelen < sizeof(*lip))
 432                         return -EINVAL;
 433
 434                 if (lip->l2tp_family != AF_INET) {
 435                         if (lip->l2tp_family != AF_UNSPEC)
 436                                 return -EAFNOSUPPORT;
 437                 }
 438
 439                 daddr = lip->l2tp_addr.s_addr;
 440         } else {
 441                 if (sk->sk_state != TCP_ESTABLISHED)
 442                         return -EDESTADDRREQ;
 443
 444                 daddr = inet->inet_daddr;
 445                 connected = 1;
 446         }
 447
 448         /* Allocate a socket buffer */
 449         rc = -ENOMEM;
 450         skb = sock_wmalloc(sk, 2 + NET_SKB_PAD + sizeof(struct iphdr) +
 451                            4 + len, 0, GFP_KERNEL);
 452         if (!skb)
 453                 goto error;
 454
 455         /* Reserve space for headers, putting IP header on 4-byte boundary. */
 456         skb_reserve(skb, 2 + NET_SKB_PAD);
 457         skb_reset_network_header(skb);
 458         skb_reserve(skb, sizeof(struct iphdr));
 459         skb_reset_transport_header(skb);
 460
 461         /* Insert 0 session_id */
 462         *((__be32 *) skb_put(skb, 4)) = 0;
 463
 464         /* Copy user data into skb */
 465         rc = memcpy_fromiovec(skb_put(skb, len), msg->msg_iov, len);
 466         if (rc < 0) {
 467                 kfree_skb(skb);
 468                 goto error;
 469         }
 470
 471         if (connected)
 472                 rt = (struct rtable *) __sk_dst_check(sk, 0);
 473
 474         if (rt == NULL) {
 475                 /* Use correct destination address if we have options. */
 476                 if (opt && opt->srr)
 477                         daddr = opt->faddr;
 478
 479                 {
 480                         struct flowi fl = { .oif = sk->sk_bound_dev_if,
 481                                             .nl_u = { .ip4_u = {
 482                                                         .daddr = daddr,
 483                                                         .saddr = inet->inet_saddr,
 484                                                         .tos = RT_CONN_FLAGS(sk) } },
 485                                             .proto = sk->sk_protocol,
 486                                             .flags = inet_sk_flowi_flags(sk),
 487                                             .uli_u = { .ports = {
 488                                                          .sport = inet->inet_sport,
 489                                                          .dport = inet->inet_dport } } };
 490
 491                         /* If this fails, retransmit mechanism of transport layer will
 492                          * keep trying until route appears or the connection times
 493                          * itself out.
 494                          */
 495                         security_sk_classify_flow(sk, &fl);
 496                         if (ip_route_output_flow(sock_net(sk), &rt, &fl, sk, 0))
 497                                 goto no_route;
 498                 }
 499                 sk_setup_caps(sk, &rt->dst);
 500         }
 501         skb_dst_set(skb, dst_clone(&rt->dst));
 502
 503         /* Queue the packet to IP for output */
 504         rc = ip_queue_xmit(skb);
 505
 506 error:
 507         /* Update stats */
 508         if (rc >= 0) {
 509                 lsa->tx_packets++;
 510                 lsa->tx_bytes += len;
 511                 rc = len;
 512         } else {
 513                 lsa->tx_errors++;
 514         }
 515
 516         return rc;
 517
 518 no_route:
 519         IP_INC_STATS(sock_net(sk), IPSTATS_MIB_OUTNOROUTES);
 520         kfree_skb(skb);
 521         return -EHOSTUNREACH;
 522 }
 523
 524 static int l2tp_ip_recvmsg(struct kiocb *iocb, struct sock *sk, struct msghdr *msg,
 525                            size_t len, int noblock, int flags, int *addr_len)
 526 {
 527         struct inet_sock *inet = inet_sk(sk);
 528         struct l2tp_ip_sock *lsk = l2tp_ip_sk(sk);
 529         size_t copied = 0;
 530         int err = -EOPNOTSUPP;
 531         struct sockaddr_in *sin = (struct sockaddr_in *)msg->msg_name;
 532         struct sk_buff *skb;
 533
 534         if (flags & MSG_OOB)
 535                 goto out;
 536
 537         if (addr_len)
 538                 *addr_len = sizeof(*sin);
 539
 540         skb = skb_recv_datagram(sk, flags, noblock, &err);
 541         if (!skb)
 542                 goto out;
 543
 544         copied = skb->len;
 545         if (len < copied) {
 546                 msg->msg_flags |= MSG_TRUNC;
 547                 copied = len;
 548         }
 549
 550         err = skb_copy_datagram_iovec(skb, 0, msg->msg_iov, copied);
 551         if (err)
 552                 goto done;
 553
 554         sock_recv_timestamp(msg, sk, skb);
 555
 556         /* Copy the address. */
 557         if (sin) {
 558                 sin->sin_family = AF_INET;
 559                 sin->sin_addr.s_addr = ip_hdr(skb)->saddr;
 560                 sin->sin_port = 0;
 561                 memset(&sin->sin_zero, 0, sizeof(sin->sin_zero));
 562         }
 563         if (inet->cmsg_flags)
 564                 ip_cmsg_recv(msg, skb);
 565         if (flags & MSG_TRUNC)
 566                 copied = skb->len;
 567 done:
 568         skb_free_datagram(sk, skb);
 569 out:
 570         if (err) {
 571                 lsk->rx_errors++;
 572                 return err;
 573         }
 574
 575         lsk->rx_packets++;
 576         lsk->rx_bytes += copied;
 577
 578         return copied;
 579 }
 580
 581 struct proto l2tp_ip_prot = {
 582         .name              = "L2TP/IP",
 583         .owner             = THIS_MODULE,
 584         .init              = l2tp_ip_open,
 585         .close             = l2tp_ip_close,
 586         .bind              = l2tp_ip_bind,
 587         .connect           = l2tp_ip_connect,
 588         .disconnect        = udp_disconnect,
 589         .ioctl             = udp_ioctl,
 590         .destroy           = l2tp_ip_destroy_sock,
 591         .setsockopt        = ip_setsockopt,
 592         .getsockopt        = ip_getsockopt,
 593         .sendmsg           = l2tp_ip_sendmsg,
 594         .recvmsg           = l2tp_ip_recvmsg,
 595         .backlog_rcv       = l2tp_ip_backlog_recv,
 596         .hash              = inet_hash,
 597         .unhash            = inet_unhash,
 598         .obj_size          = sizeof(struct l2tp_ip_sock),
 599 #ifdef CONFIG_COMPAT
 600         .compat_setsockopt = compat_ip_setsockopt,
 601         .compat_getsockopt = compat_ip_getsockopt,
 602 #endif
 603 };
 604
 605 static const struct proto_ops l2tp_ip_ops = {
 606         .family            = PF_INET,
 607         .owner             = THIS_MODULE,
 608         .release           = inet_release,
 609         .bind              = inet_bind,
 610         .connect           = inet_dgram_connect,
 611         .socketpair        = sock_no_socketpair,
 612         .accept            = sock_no_accept,
 613         .getname           = l2tp_ip_getname,
 614         .poll              = datagram_poll,
 615         .ioctl             = inet_ioctl,
 616         .listen            = sock_no_listen,
 617         .shutdown          = inet_shutdown,
 618         .setsockopt        = sock_common_setsockopt,
 619         .getsockopt        = sock_common_getsockopt,
 620         .sendmsg           = inet_sendmsg,
 621         .recvmsg           = sock_common_recvmsg,
 622         .mmap              = sock_no_mmap,
 623         .sendpage          = sock_no_sendpage,
 624 #ifdef CONFIG_COMPAT
 625         .compat_setsockopt = compat_sock_common_setsockopt,
 626         .compat_getsockopt = compat_sock_common_getsockopt,
 627 #endif
 628 };
 629
 630 static struct inet_protosw l2tp_ip_protosw = {
 631         .type           = SOCK_DGRAM,
 632         .protocol       = IPPROTO_L2TP,
 633         .prot           = &l2tp_ip_prot,
 634         .ops            = &l2tp_ip_ops,
 635         .no_check       = 0,
 636 };
 637
 638 static struct net_protocol l2tp_ip_protocol __read_mostly = {
 639         .handler        = l2tp_ip_recv,
 640 };
 641
 642 static int __init l2tp_ip_init(void)
 643 {
 644         int err;
 645
 646         printk(KERN_INFO "L2TP IP encapsulation support (L2TPv3)\n");
 647
 648         err = proto_register(&l2tp_ip_prot, 1);
 649         if (err != 0)
 650                 goto out;
 651
 652         err = inet_add_protocol(&l2tp_ip_protocol, IPPROTO_L2TP);
 653         if (err)
 654                 goto out1;
 655
 656         inet_register_protosw(&l2tp_ip_protosw);
 657         return 0;
 658
 659 out1:
 660         proto_unregister(&l2tp_ip_prot);
 661 out:
 662         return err;
 663 }
 664
 665 static void __exit l2tp_ip_exit(void)
 666 {
 667         inet_unregister_protosw(&l2tp_ip_protosw);
 668         inet_del_protocol(&l2tp_ip_protocol, IPPROTO_L2TP);
 669         proto_unregister(&l2tp_ip_prot);
 670 }
 671
 672 module_init(l2tp_ip_init);
 673 module_exit(l2tp_ip_exit);
 674
 675 MODULE_LICENSE("GPL");
 676 MODULE_AUTHOR("James Chapman <jchapman@katalix.com>");
 677 MODULE_DESCRIPTION("L2TP over IP");
 678 MODULE_VERSION("1.0");
 679 MODULE_ALIAS_NET_PF_PROTO_TYPE(PF_INET, SOCK_DGRAM, IPPROTO_L2TP);