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 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
  13
  14 #include <asm/ioctls.h>
  15 #include <linux/icmp.h>
  16 #include <linux/module.h>
  17 #include <linux/skbuff.h>
  18 #include <linux/random.h>
  19 #include <linux/socket.h>
  20 #include <linux/l2tp.h>
  21 #include <linux/in.h>
  22 #include <net/sock.h>
  23 #include <net/ip.h>
  24 #include <net/icmp.h>
  25 #include <net/udp.h>
  26 #include <net/inet_common.h>
  27 #include <net/inet_hashtables.h>
  28 #include <net/tcp_states.h>
  29 #include <net/protocol.h>
  30 #include <net/xfrm.h>
  31
  32 #include "l2tp_core.h"
  33
  34 struct l2tp_ip_sock {
  35         /* inet_sock has to be the first member of l2tp_ip_sock */
  36         struct inet_sock        inet;
  37
  38         u32                     conn_id;
  39         u32                     peer_conn_id;
  40 };
  41
  42 static DEFINE_RWLOCK(l2tp_ip_lock);
  43 static struct hlist_head l2tp_ip_table;
  44 static struct hlist_head l2tp_ip_bind_table;
  45
  46 static inline struct l2tp_ip_sock *l2tp_ip_sk(const struct sock *sk)
  47 {
  48         return (struct l2tp_ip_sock *)sk;
  49 }
  50
  51 static struct sock *__l2tp_ip_bind_lookup(const struct net *net, __be32 laddr,
  52                                           __be32 raddr, int dif, u32 tunnel_id)
  53 {
  54         struct sock *sk;
  55
  56         sk_for_each_bound(sk, &l2tp_ip_bind_table) {
  57                 const struct l2tp_ip_sock *l2tp = l2tp_ip_sk(sk);
  58                 const struct inet_sock *inet = inet_sk(sk);
  59
  60                 if (!net_eq(sock_net(sk), net))
  61                         continue;
  62
  63                 if (sk->sk_bound_dev_if && dif && sk->sk_bound_dev_if != dif)
  64                         continue;
  65
  66                 if (inet->inet_rcv_saddr && laddr &&
  67                     inet->inet_rcv_saddr != laddr)
  68                         continue;
  69
  70                 if (inet->inet_daddr && raddr && inet->inet_daddr != raddr)
  71                         continue;
  72
  73                 if (l2tp->conn_id != tunnel_id)
  74                         continue;
  75
  76                 goto found;
  77         }
  78
  79         sk = NULL;
  80 found:
  81         return sk;
  82 }
  83
  84 /* When processing receive frames, there are two cases to
  85  * consider. Data frames consist of a non-zero session-id and an
  86  * optional cookie. Control frames consist of a regular L2TP header
  87  * preceded by 32-bits of zeros.
  88  *
  89  * L2TPv3 Session Header Over IP
  90  *
  91  *  0                   1                   2                   3
  92  *  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
  93  * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
  94  * |                           Session ID                          |
  95  * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
  96  * |               Cookie (optional, maximum 64 bits)...
  97  * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
  98  *                                                                 |
  99  * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 100  *
 101  * L2TPv3 Control Message Header Over IP
 102  *
 103  *  0                   1                   2                   3
 104  *  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
 105  * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 106  * |                      (32 bits of zeros)                       |
 107  * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 108  * |T|L|x|x|S|x|x|x|x|x|x|x|  Ver  |             Length            |
 109  * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 110  * |                     Control Connection ID                     |
 111  * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 112  * |               Ns              |               Nr              |
 113  * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 114  *
 115  * All control frames are passed to userspace.
 116  */
 117 static int l2tp_ip_recv(struct sk_buff *skb)
 118 {
 119         struct net *net = dev_net(skb->dev);
 120         struct sock *sk;
 121         u32 session_id;
 122         u32 tunnel_id;
 123         unsigned char *ptr, *optr;
 124         struct l2tp_session *session;
 125         struct l2tp_tunnel *tunnel = NULL;
 126         int length;
 127
 128         if (!pskb_may_pull(skb, 4))
 129                 goto discard;
 130
 131         /* Point to L2TP header */
 132         optr = ptr = skb->data;
 133         session_id = ntohl(*((__be32 *) ptr));
 134         ptr += 4;
 135
 136         /* RFC3931: L2TP/IP packets have the first 4 bytes containing
 137          * the session_id. If it is 0, the packet is a L2TP control
 138          * frame and the session_id value can be discarded.
 139          */
 140         if (session_id == 0) {
 141                 __skb_pull(skb, 4);
 142                 goto pass_up;
 143         }
 144
 145         /* Ok, this is a data packet. Lookup the session. */
 146         session = l2tp_session_find(net, NULL, session_id);
 147         if (session == NULL)
 148                 goto discard;
 149
 150         tunnel = session->tunnel;
 151         if (tunnel == NULL)
 152                 goto discard;
 153
 154         /* Trace packet contents, if enabled */
 155         if (tunnel->debug & L2TP_MSG_DATA) {
 156                 length = min(32u, skb->len);
 157                 if (!pskb_may_pull(skb, length))
 158                         goto discard;
 159
 160                 /* Point to L2TP header */
 161                 optr = ptr = skb->data;
 162                 ptr += 4;
 163                 pr_debug("%s: ip recv\n", tunnel->name);
 164                 print_hex_dump_bytes("", DUMP_PREFIX_OFFSET, ptr, length);
 165         }
 166
 167         l2tp_recv_common(session, skb, ptr, optr, 0, skb->len, tunnel->recv_payload_hook);
 168
 169         return 0;
 170
 171 pass_up:
 172         /* Get the tunnel_id from the L2TP header */
 173         if (!pskb_may_pull(skb, 12))
 174                 goto discard;
 175
 176         if ((skb->data[0] & 0xc0) != 0xc0)
 177                 goto discard;
 178
 179         tunnel_id = ntohl(*(__be32 *) &skb->data[4]);
 180         tunnel = l2tp_tunnel_find(net, tunnel_id);
 181         if (tunnel != NULL)
 182                 sk = tunnel->sock;
 183         else {
 184                 struct iphdr *iph = (struct iphdr *) skb_network_header(skb);
 185
 186                 read_lock_bh(&l2tp_ip_lock);
 187                 sk = __l2tp_ip_bind_lookup(net, iph->daddr, iph->saddr,
 188                                            inet_iif(skb), tunnel_id);
 189                 if (!sk) {
 190                         read_unlock_bh(&l2tp_ip_lock);
 191                         goto discard;
 192                 }
 193
 194                 sock_hold(sk);
 195                 read_unlock_bh(&l2tp_ip_lock);
 196         }
 197
 198         if (!xfrm4_policy_check(sk, XFRM_POLICY_IN, skb))
 199                 goto discard_put;
 200
 201         nf_reset(skb);
 202
 203         return sk_receive_skb(sk, skb, 1);
 204
 205 discard_put:
 206         sock_put(sk);
 207
 208 discard:
 209         kfree_skb(skb);
 210         return 0;
 211 }
 212
 213 static int l2tp_ip_open(struct sock *sk)
 214 {
 215         /* Prevent autobind. We don't have ports. */
 216         inet_sk(sk)->inet_num = IPPROTO_L2TP;
 217
 218         write_lock_bh(&l2tp_ip_lock);
 219         sk_add_node(sk, &l2tp_ip_table);
 220         write_unlock_bh(&l2tp_ip_lock);
 221
 222         return 0;
 223 }
 224
 225 static void l2tp_ip_close(struct sock *sk, long timeout)
 226 {
 227         write_lock_bh(&l2tp_ip_lock);
 228         hlist_del_init(&sk->sk_bind_node);
 229         sk_del_node_init(sk);
 230         write_unlock_bh(&l2tp_ip_lock);
 231         sk_common_release(sk);
 232 }
 233
 234 static void l2tp_ip_destroy_sock(struct sock *sk)
 235 {
 236         struct sk_buff *skb;
 237         struct l2tp_tunnel *tunnel = l2tp_sock_to_tunnel(sk);
 238
 239         while ((skb = __skb_dequeue_tail(&sk->sk_write_queue)) != NULL)
 240                 kfree_skb(skb);
 241
 242         if (tunnel) {
 243                 l2tp_tunnel_closeall(tunnel);
 244                 sock_put(sk);
 245         }
 246
 247         sk_refcnt_debug_dec(sk);
 248 }
 249
 250 static int l2tp_ip_bind(struct sock *sk, struct sockaddr *uaddr, int addr_len)
 251 {
 252         struct inet_sock *inet = inet_sk(sk);
 253         struct sockaddr_l2tpip *addr = (struct sockaddr_l2tpip *) uaddr;
 254         struct net *net = sock_net(sk);
 255         int ret;
 256         int chk_addr_ret;
 257
 258         if (addr_len < sizeof(struct sockaddr_l2tpip))
 259                 return -EINVAL;
 260         if (addr->l2tp_family != AF_INET)
 261                 return -EINVAL;
 262
 263         lock_sock(sk);
 264
 265         ret = -EINVAL;
 266         if (!sock_flag(sk, SOCK_ZAPPED))
 267                 goto out;
 268
 269         if (sk->sk_state != TCP_CLOSE)
 270                 goto out;
 271
 272         chk_addr_ret = inet_addr_type(net, addr->l2tp_addr.s_addr);
 273         ret = -EADDRNOTAVAIL;
 274         if (addr->l2tp_addr.s_addr && chk_addr_ret != RTN_LOCAL &&
 275             chk_addr_ret != RTN_MULTICAST && chk_addr_ret != RTN_BROADCAST)
 276                 goto out;
 277
 278         if (addr->l2tp_addr.s_addr)
 279                 inet->inet_rcv_saddr = inet->inet_saddr = addr->l2tp_addr.s_addr;
 280         if (chk_addr_ret == RTN_MULTICAST || chk_addr_ret == RTN_BROADCAST)
 281                 inet->inet_saddr = 0;  /* Use device */
 282
 283         write_lock_bh(&l2tp_ip_lock);
 284         if (__l2tp_ip_bind_lookup(net, addr->l2tp_addr.s_addr, 0,
 285                                   sk->sk_bound_dev_if, addr->l2tp_conn_id)) {
 286                 write_unlock_bh(&l2tp_ip_lock);
 287                 ret = -EADDRINUSE;
 288                 goto out;
 289         }
 290
 291         sk_dst_reset(sk);
 292         l2tp_ip_sk(sk)->conn_id = addr->l2tp_conn_id;
 293
 294         sk_add_bind_node(sk, &l2tp_ip_bind_table);
 295         sk_del_node_init(sk);
 296         write_unlock_bh(&l2tp_ip_lock);
 297
 298         ret = 0;
 299         sock_reset_flag(sk, SOCK_ZAPPED);
 300
 301 out:
 302         release_sock(sk);
 303
 304         return ret;
 305 }
 306
 307 static int l2tp_ip_connect(struct sock *sk, struct sockaddr *uaddr, int addr_len)
 308 {
 309         struct sockaddr_l2tpip *lsa = (struct sockaddr_l2tpip *) uaddr;
 310         int rc;
 311
 312         if (addr_len < sizeof(*lsa))
 313                 return -EINVAL;
 314
 315         if (ipv4_is_multicast(lsa->l2tp_addr.s_addr))
 316                 return -EINVAL;
 317
 318         lock_sock(sk);
 319
 320         /* Must bind first - autobinding does not work */
 321         if (sock_flag(sk, SOCK_ZAPPED)) {
 322                 rc = -EINVAL;
 323                 goto out_sk;
 324         }
 325
 326         rc = __ip4_datagram_connect(sk, uaddr, addr_len);
 327         if (rc < 0)
 328                 goto out_sk;
 329
 330         l2tp_ip_sk(sk)->peer_conn_id = lsa->l2tp_conn_id;
 331
 332         write_lock_bh(&l2tp_ip_lock);
 333         hlist_del_init(&sk->sk_bind_node);
 334         sk_add_bind_node(sk, &l2tp_ip_bind_table);
 335         write_unlock_bh(&l2tp_ip_lock);
 336
 337 out_sk:
 338         release_sock(sk);
 339
 340         return rc;
 341 }
 342
 343 static int l2tp_ip_disconnect(struct sock *sk, int flags)
 344 {
 345         if (sock_flag(sk, SOCK_ZAPPED))
 346                 return 0;
 347
 348         return __udp_disconnect(sk, flags);
 349 }
 350
 351 static int l2tp_ip_getname(struct socket *sock, struct sockaddr *uaddr,
 352                            int *uaddr_len, int peer)
 353 {
 354         struct sock *sk         = sock->sk;
 355         struct inet_sock *inet  = inet_sk(sk);
 356         struct l2tp_ip_sock *lsk = l2tp_ip_sk(sk);
 357         struct sockaddr_l2tpip *lsa = (struct sockaddr_l2tpip *)uaddr;
 358
 359         memset(lsa, 0, sizeof(*lsa));
 360         lsa->l2tp_family = AF_INET;
 361         if (peer) {
 362                 if (!inet->inet_dport)
 363                         return -ENOTCONN;
 364                 lsa->l2tp_conn_id = lsk->peer_conn_id;
 365                 lsa->l2tp_addr.s_addr = inet->inet_daddr;
 366         } else {
 367                 __be32 addr = inet->inet_rcv_saddr;
 368                 if (!addr)
 369                         addr = inet->inet_saddr;
 370                 lsa->l2tp_conn_id = lsk->conn_id;
 371                 lsa->l2tp_addr.s_addr = addr;
 372         }
 373         *uaddr_len = sizeof(*lsa);
 374         return 0;
 375 }
 376
 377 static int l2tp_ip_backlog_recv(struct sock *sk, struct sk_buff *skb)
 378 {
 379         int rc;
 380
 381         /* Charge it to the socket, dropping if the queue is full. */
 382         rc = sock_queue_rcv_skb(sk, skb);
 383         if (rc < 0)
 384                 goto drop;
 385
 386         return 0;
 387
 388 drop:
 389         IP_INC_STATS(sock_net(sk), IPSTATS_MIB_INDISCARDS);
 390         kfree_skb(skb);
 391         return 0;
 392 }
 393
 394 /* Userspace will call sendmsg() on the tunnel socket to send L2TP
 395  * control frames.
 396  */
 397 static int l2tp_ip_sendmsg(struct sock *sk, struct msghdr *msg, size_t len)
 398 {
 399         struct sk_buff *skb;
 400         int rc;
 401         struct inet_sock *inet = inet_sk(sk);
 402         struct rtable *rt = NULL;
 403         struct flowi4 *fl4;
 404         int connected = 0;
 405         __be32 daddr;
 406
 407         lock_sock(sk);
 408
 409         rc = -ENOTCONN;
 410         if (sock_flag(sk, SOCK_DEAD))
 411                 goto out;
 412
 413         /* Get and verify the address. */
 414         if (msg->msg_name) {
 415                 DECLARE_SOCKADDR(struct sockaddr_l2tpip *, lip, msg->msg_name);
 416                 rc = -EINVAL;
 417                 if (msg->msg_namelen < sizeof(*lip))
 418                         goto out;
 419
 420                 if (lip->l2tp_family != AF_INET) {
 421                         rc = -EAFNOSUPPORT;
 422                         if (lip->l2tp_family != AF_UNSPEC)
 423                                 goto out;
 424                 }
 425
 426                 daddr = lip->l2tp_addr.s_addr;
 427         } else {
 428                 rc = -EDESTADDRREQ;
 429                 if (sk->sk_state != TCP_ESTABLISHED)
 430                         goto out;
 431
 432                 daddr = inet->inet_daddr;
 433                 connected = 1;
 434         }
 435
 436         /* Allocate a socket buffer */
 437         rc = -ENOMEM;
 438         skb = sock_wmalloc(sk, 2 + NET_SKB_PAD + sizeof(struct iphdr) +
 439                            4 + len, 0, GFP_KERNEL);
 440         if (!skb)
 441                 goto error;
 442
 443         /* Reserve space for headers, putting IP header on 4-byte boundary. */
 444         skb_reserve(skb, 2 + NET_SKB_PAD);
 445         skb_reset_network_header(skb);
 446         skb_reserve(skb, sizeof(struct iphdr));
 447         skb_reset_transport_header(skb);
 448
 449         /* Insert 0 session_id */
 450         *((__be32 *) skb_put(skb, 4)) = 0;
 451
 452         /* Copy user data into skb */
 453         rc = memcpy_from_msg(skb_put(skb, len), msg, len);
 454         if (rc < 0) {
 455                 kfree_skb(skb);
 456                 goto error;
 457         }
 458
 459         fl4 = &inet->cork.fl.u.ip4;
 460         if (connected)
 461                 rt = (struct rtable *) __sk_dst_check(sk, 0);
 462
 463         rcu_read_lock();
 464         if (rt == NULL) {
 465                 const struct ip_options_rcu *inet_opt;
 466
 467                 inet_opt = rcu_dereference(inet->inet_opt);
 468
 469                 /* Use correct destination address if we have options. */
 470                 if (inet_opt && inet_opt->opt.srr)
 471                         daddr = inet_opt->opt.faddr;
 472
 473                 /* If this fails, retransmit mechanism of transport layer will
 474                  * keep trying until route appears or the connection times
 475                  * itself out.
 476                  */
 477                 rt = ip_route_output_ports(sock_net(sk), fl4, sk,
 478                                            daddr, inet->inet_saddr,
 479                                            inet->inet_dport, inet->inet_sport,
 480                                            sk->sk_protocol, RT_CONN_FLAGS(sk),
 481                                            sk->sk_bound_dev_if);
 482                 if (IS_ERR(rt))
 483                         goto no_route;
 484                 if (connected) {
 485                         sk_setup_caps(sk, &rt->dst);
 486                 } else {
 487                         skb_dst_set(skb, &rt->dst);
 488                         goto xmit;
 489                 }
 490         }
 491
 492         /* We dont need to clone dst here, it is guaranteed to not disappear.
 493          *  __dev_xmit_skb() might force a refcount if needed.
 494          */
 495         skb_dst_set_noref(skb, &rt->dst);
 496
 497 xmit:
 498         /* Queue the packet to IP for output */
 499         rc = ip_queue_xmit(sk, skb, &inet->cork.fl);
 500         rcu_read_unlock();
 501
 502 error:
 503         if (rc >= 0)
 504                 rc = len;
 505
 506 out:
 507         release_sock(sk);
 508         return rc;
 509
 510 no_route:
 511         rcu_read_unlock();
 512         IP_INC_STATS(sock_net(sk), IPSTATS_MIB_OUTNOROUTES);
 513         kfree_skb(skb);
 514         rc = -EHOSTUNREACH;
 515         goto out;
 516 }
 517
 518 static int l2tp_ip_recvmsg(struct sock *sk, struct msghdr *msg,
 519                            size_t len, int noblock, int flags, int *addr_len)
 520 {
 521         struct inet_sock *inet = inet_sk(sk);
 522         size_t copied = 0;
 523         int err = -EOPNOTSUPP;
 524         DECLARE_SOCKADDR(struct sockaddr_in *, sin, msg->msg_name);
 525         struct sk_buff *skb;
 526
 527         if (flags & MSG_OOB)
 528                 goto out;
 529
 530         skb = skb_recv_datagram(sk, flags, noblock, &err);
 531         if (!skb)
 532                 goto out;
 533
 534         copied = skb->len;
 535         if (len < copied) {
 536                 msg->msg_flags |= MSG_TRUNC;
 537                 copied = len;
 538         }
 539
 540         err = skb_copy_datagram_msg(skb, 0, msg, copied);
 541         if (err)
 542                 goto done;
 543
 544         sock_recv_timestamp(msg, sk, skb);
 545
 546         /* Copy the address. */
 547         if (sin) {
 548                 sin->sin_family = AF_INET;
 549                 sin->sin_addr.s_addr = ip_hdr(skb)->saddr;
 550                 sin->sin_port = 0;
 551                 memset(&sin->sin_zero, 0, sizeof(sin->sin_zero));
 552                 *addr_len = sizeof(*sin);
 553         }
 554         if (inet->cmsg_flags)
 555                 ip_cmsg_recv(msg, skb);
 556         if (flags & MSG_TRUNC)
 557                 copied = skb->len;
 558 done:
 559         skb_free_datagram(sk, skb);
 560 out:
 561         return err ? err : copied;
 562 }
 563
 564 int l2tp_ioctl(struct sock *sk, int cmd, unsigned long arg)
 565 {
 566         struct sk_buff *skb;
 567         int amount;
 568
 569         switch (cmd) {
 570         case SIOCOUTQ:
 571                 amount = sk_wmem_alloc_get(sk);
 572                 break;
 573         case SIOCINQ:
 574                 spin_lock_bh(&sk->sk_receive_queue.lock);
 575                 skb = skb_peek(&sk->sk_receive_queue);
 576                 amount = skb ? skb->len : 0;
 577                 spin_unlock_bh(&sk->sk_receive_queue.lock);
 578                 break;
 579
 580         default:
 581                 return -ENOIOCTLCMD;
 582         }
 583
 584         return put_user(amount, (int __user *)arg);
 585 }
 586 EXPORT_SYMBOL(l2tp_ioctl);
 587
 588 static struct proto l2tp_ip_prot = {
 589         .name              = "L2TP/IP",
 590         .owner             = THIS_MODULE,
 591         .init              = l2tp_ip_open,
 592         .close             = l2tp_ip_close,
 593         .bind              = l2tp_ip_bind,
 594         .connect           = l2tp_ip_connect,
 595         .disconnect        = l2tp_ip_disconnect,
 596         .ioctl             = l2tp_ioctl,
 597         .destroy           = l2tp_ip_destroy_sock,
 598         .setsockopt        = ip_setsockopt,
 599         .getsockopt        = ip_getsockopt,
 600         .sendmsg           = l2tp_ip_sendmsg,
 601         .recvmsg           = l2tp_ip_recvmsg,
 602         .backlog_rcv       = l2tp_ip_backlog_recv,
 603         .hash              = inet_hash,
 604         .unhash            = inet_unhash,
 605         .obj_size          = sizeof(struct l2tp_ip_sock),
 606 #ifdef CONFIG_COMPAT
 607         .compat_setsockopt = compat_ip_setsockopt,
 608         .compat_getsockopt = compat_ip_getsockopt,
 609 #endif
 610 };
 611
 612 static const struct proto_ops l2tp_ip_ops = {
 613         .family            = PF_INET,
 614         .owner             = THIS_MODULE,
 615         .release           = inet_release,
 616         .bind              = inet_bind,
 617         .connect           = inet_dgram_connect,
 618         .socketpair        = sock_no_socketpair,
 619         .accept            = sock_no_accept,
 620         .getname           = l2tp_ip_getname,
 621         .poll              = datagram_poll,
 622         .ioctl             = inet_ioctl,
 623         .listen            = sock_no_listen,
 624         .shutdown          = inet_shutdown,
 625         .setsockopt        = sock_common_setsockopt,
 626         .getsockopt        = sock_common_getsockopt,
 627         .sendmsg           = inet_sendmsg,
 628         .recvmsg           = sock_common_recvmsg,
 629         .mmap              = sock_no_mmap,
 630         .sendpage          = sock_no_sendpage,
 631 #ifdef CONFIG_COMPAT
 632         .compat_setsockopt = compat_sock_common_setsockopt,
 633         .compat_getsockopt = compat_sock_common_getsockopt,
 634 #endif
 635 };
 636
 637 static struct inet_protosw l2tp_ip_protosw = {
 638         .type           = SOCK_DGRAM,
 639         .protocol       = IPPROTO_L2TP,
 640         .prot           = &l2tp_ip_prot,
 641         .ops            = &l2tp_ip_ops,
 642 };
 643
 644 static struct net_protocol l2tp_ip_protocol __read_mostly = {
 645         .handler        = l2tp_ip_recv,
 646         .netns_ok       = 1,
 647 };
 648
 649 static int __init l2tp_ip_init(void)
 650 {
 651         int err;
 652
 653         pr_info("L2TP IP encapsulation support (L2TPv3)\n");
 654
 655         err = proto_register(&l2tp_ip_prot, 1);
 656         if (err != 0)
 657                 goto out;
 658
 659         err = inet_add_protocol(&l2tp_ip_protocol, IPPROTO_L2TP);
 660         if (err)
 661                 goto out1;
 662
 663         inet_register_protosw(&l2tp_ip_protosw);
 664         return 0;
 665
 666 out1:
 667         proto_unregister(&l2tp_ip_prot);
 668 out:
 669         return err;
 670 }
 671
 672 static void __exit l2tp_ip_exit(void)
 673 {
 674         inet_unregister_protosw(&l2tp_ip_protosw);
 675         inet_del_protocol(&l2tp_ip_protocol, IPPROTO_L2TP);
 676         proto_unregister(&l2tp_ip_prot);
 677 }
 678
 679 module_init(l2tp_ip_init);
 680 module_exit(l2tp_ip_exit);
 681
 682 MODULE_LICENSE("GPL");
 683 MODULE_AUTHOR("James Chapman <jchapman@katalix.com>");
 684 MODULE_DESCRIPTION("L2TP over IP");
 685 MODULE_VERSION("1.0");
 686
 687 /* Use the value of SOCK_DGRAM (2) directory, because __stringify doesn't like
 688  * enums
 689  */
 690 MODULE_ALIAS_NET_PF_PROTO_TYPE(PF_INET, 2, IPPROTO_L2TP);
 691 MODULE_ALIAS_NET_PF_PROTO(PF_INET, IPPROTO_L2TP);