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(struct net *net, __be32 laddr, int dif, u32 tunnel_id)
  52 {
  53         struct sock *sk;
  54
  55         sk_for_each_bound(sk, &l2tp_ip_bind_table) {
  56                 struct inet_sock *inet = inet_sk(sk);
  57                 struct l2tp_ip_sock *l2tp = l2tp_ip_sk(sk);
  58
  59                 if (l2tp == NULL)
  60                         continue;
  61
  62                 if ((l2tp->conn_id == tunnel_id) &&
  63                     net_eq(sock_net(sk), net) &&
  64                     !(inet->inet_rcv_saddr && inet->inet_rcv_saddr != laddr) &&
  65                     !(sk->sk_bound_dev_if && sk->sk_bound_dev_if != dif))
  66                         goto found;
  67         }
  68
  69         sk = NULL;
  70 found:
  71         return sk;
  72 }
  73
  74 static inline struct sock *l2tp_ip_bind_lookup(struct net *net, __be32 laddr, int dif, u32 tunnel_id)
  75 {
  76         struct sock *sk = __l2tp_ip_bind_lookup(net, laddr, dif, tunnel_id);
  77         if (sk)
  78                 sock_hold(sk);
  79
  80         return sk;
  81 }
  82
  83 /* When processing receive frames, there are two cases to
  84  * consider. Data frames consist of a non-zero session-id and an
  85  * optional cookie. Control frames consist of a regular L2TP header
  86  * preceded by 32-bits of zeros.
  87  *
  88  * L2TPv3 Session Header Over IP
  89  *
  90  *  0                   1                   2                   3
  91  *  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
  92  * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
  93  * |                           Session ID                          |
  94  * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
  95  * |               Cookie (optional, maximum 64 bits)...
  96  * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
  97  *                                                                 |
  98  * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
  99  *
 100  * L2TPv3 Control Message Header Over IP
 101  *
 102  *  0                   1                   2                   3
 103  *  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
 104  * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 105  * |                      (32 bits of zeros)                       |
 106  * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 107  * |T|L|x|x|S|x|x|x|x|x|x|x|  Ver  |             Length            |
 108  * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 109  * |                     Control Connection ID                     |
 110  * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 111  * |               Ns              |               Nr              |
 112  * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 113  *
 114  * All control frames are passed to userspace.
 115  */
 116 static int l2tp_ip_recv(struct sk_buff *skb)
 117 {
 118         struct net *net = dev_net(skb->dev);
 119         struct sock *sk;
 120         u32 session_id;
 121         u32 tunnel_id;
 122         unsigned char *ptr, *optr;
 123         struct l2tp_session *session;
 124         struct l2tp_tunnel *tunnel = NULL;
 125         int length;
 126
 127         if (!pskb_may_pull(skb, 4))
 128                 goto discard;
 129
 130         /* Point to L2TP header */
 131         optr = ptr = skb->data;
 132         session_id = ntohl(*((__be32 *) ptr));
 133         ptr += 4;
 134
 135         /* RFC3931: L2TP/IP packets have the first 4 bytes containing
 136          * the session_id. If it is 0, the packet is a L2TP control
 137          * frame and the session_id value can be discarded.
 138          */
 139         if (session_id == 0) {
 140                 __skb_pull(skb, 4);
 141                 goto pass_up;
 142         }
 143
 144         /* Ok, this is a data packet. Lookup the session. */
 145         session = l2tp_session_find(net, NULL, session_id);
 146         if (session == NULL)
 147                 goto discard;
 148
 149         tunnel = session->tunnel;
 150         if (tunnel == NULL)
 151                 goto discard;
 152
 153         /* Trace packet contents, if enabled */
 154         if (tunnel->debug & L2TP_MSG_DATA) {
 155                 length = min(32u, skb->len);
 156                 if (!pskb_may_pull(skb, length))
 157                         goto discard;
 158
 159                 /* Point to L2TP header */
 160                 optr = ptr = skb->data;
 161                 ptr += 4;
 162                 pr_debug("%s: ip recv\n", tunnel->name);
 163                 print_hex_dump_bytes("", DUMP_PREFIX_OFFSET, ptr, length);
 164         }
 165
 166         l2tp_recv_common(session, skb, ptr, optr, 0, skb->len, tunnel->recv_payload_hook);
 167
 168         return 0;
 169
 170 pass_up:
 171         /* Get the tunnel_id from the L2TP header */
 172         if (!pskb_may_pull(skb, 12))
 173                 goto discard;
 174
 175         if ((skb->data[0] & 0xc0) != 0xc0)
 176                 goto discard;
 177
 178         tunnel_id = ntohl(*(__be32 *) &skb->data[4]);
 179         tunnel = l2tp_tunnel_find(net, tunnel_id);
 180         if (tunnel) {
 181                 sk = tunnel->sock;
 182                 sock_hold(sk);
 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, 0, tunnel_id);
 188                 if (!sk) {
 189                         read_unlock_bh(&l2tp_ip_lock);
 190                         goto discard;
 191                 }
 192
 193                 sock_hold(sk);
 194                 read_unlock_bh(&l2tp_ip_lock);
 195         }
 196
 197         if (!xfrm4_policy_check(sk, XFRM_POLICY_IN, skb))
 198                 goto discard_put;
 199
 200         nf_reset(skb);
 201
 202         return sk_receive_skb(sk, skb, 1);
 203
 204 discard_put:
 205         sock_put(sk);
 206
 207 discard:
 208         kfree_skb(skb);
 209         return 0;
 210 }
 211
 212 static int l2tp_ip_open(struct sock *sk)
 213 {
 214         /* Prevent autobind. We don't have ports. */
 215         inet_sk(sk)->inet_num = IPPROTO_L2TP;
 216
 217         write_lock_bh(&l2tp_ip_lock);
 218         sk_add_node(sk, &l2tp_ip_table);
 219         write_unlock_bh(&l2tp_ip_lock);
 220
 221         return 0;
 222 }
 223
 224 static void l2tp_ip_close(struct sock *sk, long timeout)
 225 {
 226         write_lock_bh(&l2tp_ip_lock);
 227         hlist_del_init(&sk->sk_bind_node);
 228         sk_del_node_init(sk);
 229         write_unlock_bh(&l2tp_ip_lock);
 230         sk_common_release(sk);
 231 }
 232
 233 static void l2tp_ip_destroy_sock(struct sock *sk)
 234 {
 235         struct sk_buff *skb;
 236         struct l2tp_tunnel *tunnel = l2tp_sock_to_tunnel(sk);
 237
 238         while ((skb = __skb_dequeue_tail(&sk->sk_write_queue)) != NULL)
 239                 kfree_skb(skb);
 240
 241         if (tunnel) {
 242                 l2tp_tunnel_closeall(tunnel);
 243                 sock_put(sk);
 244         }
 245
 246         sk_refcnt_debug_dec(sk);
 247 }
 248
 249 static int l2tp_ip_bind(struct sock *sk, struct sockaddr *uaddr, int addr_len)
 250 {
 251         struct inet_sock *inet = inet_sk(sk);
 252         struct sockaddr_l2tpip *addr = (struct sockaddr_l2tpip *) uaddr;
 253         struct net *net = sock_net(sk);
 254         int ret;
 255         int chk_addr_ret;
 256
 257         if (addr_len < sizeof(struct sockaddr_l2tpip))
 258                 return -EINVAL;
 259         if (addr->l2tp_family != AF_INET)
 260                 return -EINVAL;
 261
 262         ret = -EADDRINUSE;
 263         read_lock_bh(&l2tp_ip_lock);
 264         if (__l2tp_ip_bind_lookup(net, addr->l2tp_addr.s_addr,
 265                                   sk->sk_bound_dev_if, addr->l2tp_conn_id))
 266                 goto out_in_use;
 267
 268         read_unlock_bh(&l2tp_ip_lock);
 269
 270         lock_sock(sk);
 271         if (!sock_flag(sk, SOCK_ZAPPED))
 272                 goto out;
 273
 274         if (sk->sk_state != TCP_CLOSE || addr_len < sizeof(struct sockaddr_l2tpip))
 275                 goto out;
 276
 277         chk_addr_ret = inet_addr_type(net, addr->l2tp_addr.s_addr);
 278         ret = -EADDRNOTAVAIL;
 279         if (addr->l2tp_addr.s_addr && chk_addr_ret != RTN_LOCAL &&
 280             chk_addr_ret != RTN_MULTICAST && chk_addr_ret != RTN_BROADCAST)
 281                 goto out;
 282
 283         if (addr->l2tp_addr.s_addr)
 284                 inet->inet_rcv_saddr = inet->inet_saddr = addr->l2tp_addr.s_addr;
 285         if (chk_addr_ret == RTN_MULTICAST || chk_addr_ret == RTN_BROADCAST)
 286                 inet->inet_saddr = 0;  /* Use device */
 287         sk_dst_reset(sk);
 288
 289         l2tp_ip_sk(sk)->conn_id = addr->l2tp_conn_id;
 290
 291         write_lock_bh(&l2tp_ip_lock);
 292         sk_add_bind_node(sk, &l2tp_ip_bind_table);
 293         sk_del_node_init(sk);
 294         write_unlock_bh(&l2tp_ip_lock);
 295         ret = 0;
 296         sock_reset_flag(sk, SOCK_ZAPPED);
 297
 298 out:
 299         release_sock(sk);
 300
 301         return ret;
 302
 303 out_in_use:
 304         read_unlock_bh(&l2tp_ip_lock);
 305
 306         return ret;
 307 }
 308
 309 static int l2tp_ip_connect(struct sock *sk, struct sockaddr *uaddr, int addr_len)
 310 {
 311         struct sockaddr_l2tpip *lsa = (struct sockaddr_l2tpip *) uaddr;
 312         int rc;
 313
 314         if (sock_flag(sk, SOCK_ZAPPED)) /* Must bind first - autobinding does not work */
 315                 return -EINVAL;
 316
 317         if (addr_len < sizeof(*lsa))
 318                 return -EINVAL;
 319
 320         if (ipv4_is_multicast(lsa->l2tp_addr.s_addr))
 321                 return -EINVAL;
 322
 323         rc = ip4_datagram_connect(sk, uaddr, addr_len);
 324         if (rc < 0)
 325                 return rc;
 326
 327         lock_sock(sk);
 328
 329         l2tp_ip_sk(sk)->peer_conn_id = lsa->l2tp_conn_id;
 330
 331         write_lock_bh(&l2tp_ip_lock);
 332         hlist_del_init(&sk->sk_bind_node);
 333         sk_add_bind_node(sk, &l2tp_ip_bind_table);
 334         write_unlock_bh(&l2tp_ip_lock);
 335
 336         release_sock(sk);
 337         return rc;
 338 }
 339
 340 static int l2tp_ip_disconnect(struct sock *sk, int flags)
 341 {
 342         if (sock_flag(sk, SOCK_ZAPPED))
 343                 return 0;
 344
 345         return udp_disconnect(sk, flags);
 346 }
 347
 348 static int l2tp_ip_getname(struct socket *sock, struct sockaddr *uaddr,
 349                            int *uaddr_len, int peer)
 350 {
 351         struct sock *sk         = sock->sk;
 352         struct inet_sock *inet  = inet_sk(sk);
 353         struct l2tp_ip_sock *lsk = l2tp_ip_sk(sk);
 354         struct sockaddr_l2tpip *lsa = (struct sockaddr_l2tpip *)uaddr;
 355
 356         memset(lsa, 0, sizeof(*lsa));
 357         lsa->l2tp_family = AF_INET;
 358         if (peer) {
 359                 if (!inet->inet_dport)
 360                         return -ENOTCONN;
 361                 lsa->l2tp_conn_id = lsk->peer_conn_id;
 362                 lsa->l2tp_addr.s_addr = inet->inet_daddr;
 363         } else {
 364                 __be32 addr = inet->inet_rcv_saddr;
 365                 if (!addr)
 366                         addr = inet->inet_saddr;
 367                 lsa->l2tp_conn_id = lsk->conn_id;
 368                 lsa->l2tp_addr.s_addr = addr;
 369         }
 370         *uaddr_len = sizeof(*lsa);
 371         return 0;
 372 }
 373
 374 static int l2tp_ip_backlog_recv(struct sock *sk, struct sk_buff *skb)
 375 {
 376         int rc;
 377
 378         /* Charge it to the socket, dropping if the queue is full. */
 379         rc = sock_queue_rcv_skb(sk, skb);
 380         if (rc < 0)
 381                 goto drop;
 382
 383         return 0;
 384
 385 drop:
 386         IP_INC_STATS(sock_net(sk), IPSTATS_MIB_INDISCARDS);
 387         kfree_skb(skb);
 388         return 0;
 389 }
 390
 391 /* Userspace will call sendmsg() on the tunnel socket to send L2TP
 392  * control frames.
 393  */
 394 static int l2tp_ip_sendmsg(struct sock *sk, struct msghdr *msg, size_t len)
 395 {
 396         struct sk_buff *skb;
 397         int rc;
 398         struct inet_sock *inet = inet_sk(sk);
 399         struct rtable *rt = NULL;
 400         struct flowi4 *fl4;
 401         int connected = 0;
 402         __be32 daddr;
 403
 404         lock_sock(sk);
 405
 406         rc = -ENOTCONN;
 407         if (sock_flag(sk, SOCK_DEAD))
 408                 goto out;
 409
 410         /* Get and verify the address. */
 411         if (msg->msg_name) {
 412                 DECLARE_SOCKADDR(struct sockaddr_l2tpip *, lip, msg->msg_name);
 413                 rc = -EINVAL;
 414                 if (msg->msg_namelen < sizeof(*lip))
 415                         goto out;
 416
 417                 if (lip->l2tp_family != AF_INET) {
 418                         rc = -EAFNOSUPPORT;
 419                         if (lip->l2tp_family != AF_UNSPEC)
 420                                 goto out;
 421                 }
 422
 423                 daddr = lip->l2tp_addr.s_addr;
 424         } else {
 425                 rc = -EDESTADDRREQ;
 426                 if (sk->sk_state != TCP_ESTABLISHED)
 427                         goto out;
 428
 429                 daddr = inet->inet_daddr;
 430                 connected = 1;
 431         }
 432
 433         /* Allocate a socket buffer */
 434         rc = -ENOMEM;
 435         skb = sock_wmalloc(sk, 2 + NET_SKB_PAD + sizeof(struct iphdr) +
 436                            4 + len, 0, GFP_KERNEL);
 437         if (!skb)
 438                 goto error;
 439
 440         /* Reserve space for headers, putting IP header on 4-byte boundary. */
 441         skb_reserve(skb, 2 + NET_SKB_PAD);
 442         skb_reset_network_header(skb);
 443         skb_reserve(skb, sizeof(struct iphdr));
 444         skb_reset_transport_header(skb);
 445
 446         /* Insert 0 session_id */
 447         *((__be32 *) skb_put(skb, 4)) = 0;
 448
 449         /* Copy user data into skb */
 450         rc = memcpy_from_msg(skb_put(skb, len), msg, len);
 451         if (rc < 0) {
 452                 kfree_skb(skb);
 453                 goto error;
 454         }
 455
 456         fl4 = &inet->cork.fl.u.ip4;
 457         if (connected)
 458                 rt = (struct rtable *) __sk_dst_check(sk, 0);
 459
 460         rcu_read_lock();
 461         if (rt == NULL) {
 462                 const struct ip_options_rcu *inet_opt;
 463
 464                 inet_opt = rcu_dereference(inet->inet_opt);
 465
 466                 /* Use correct destination address if we have options. */
 467                 if (inet_opt && inet_opt->opt.srr)
 468                         daddr = inet_opt->opt.faddr;
 469
 470                 /* If this fails, retransmit mechanism of transport layer will
 471                  * keep trying until route appears or the connection times
 472                  * itself out.
 473                  */
 474                 rt = ip_route_output_ports(sock_net(sk), fl4, sk,
 475                                            daddr, inet->inet_saddr,
 476                                            inet->inet_dport, inet->inet_sport,
 477                                            sk->sk_protocol, RT_CONN_FLAGS(sk),
 478                                            sk->sk_bound_dev_if);
 479                 if (IS_ERR(rt))
 480                         goto no_route;
 481                 if (connected) {
 482                         sk_setup_caps(sk, &rt->dst);
 483                 } else {
 484                         skb_dst_set(skb, &rt->dst);
 485                         goto xmit;
 486                 }
 487         }
 488
 489         /* We dont need to clone dst here, it is guaranteed to not disappear.
 490          *  __dev_xmit_skb() might force a refcount if needed.
 491          */
 492         skb_dst_set_noref(skb, &rt->dst);
 493
 494 xmit:
 495         /* Queue the packet to IP for output */
 496         rc = ip_queue_xmit(sk, skb, &inet->cork.fl);
 497         rcu_read_unlock();
 498
 499 error:
 500         if (rc >= 0)
 501                 rc = len;
 502
 503 out:
 504         release_sock(sk);
 505         return rc;
 506
 507 no_route:
 508         rcu_read_unlock();
 509         IP_INC_STATS(sock_net(sk), IPSTATS_MIB_OUTNOROUTES);
 510         kfree_skb(skb);
 511         rc = -EHOSTUNREACH;
 512         goto out;
 513 }
 514
 515 static int l2tp_ip_recvmsg(struct sock *sk, struct msghdr *msg,
 516                            size_t len, int noblock, int flags, int *addr_len)
 517 {
 518         struct inet_sock *inet = inet_sk(sk);
 519         size_t copied = 0;
 520         int err = -EOPNOTSUPP;
 521         DECLARE_SOCKADDR(struct sockaddr_in *, sin, msg->msg_name);
 522         struct sk_buff *skb;
 523
 524         if (flags & MSG_OOB)
 525                 goto out;
 526
 527         skb = skb_recv_datagram(sk, flags, noblock, &err);
 528         if (!skb)
 529                 goto out;
 530
 531         copied = skb->len;
 532         if (len < copied) {
 533                 msg->msg_flags |= MSG_TRUNC;
 534                 copied = len;
 535         }
 536
 537         err = skb_copy_datagram_msg(skb, 0, msg, copied);
 538         if (err)
 539                 goto done;
 540
 541         sock_recv_timestamp(msg, sk, skb);
 542
 543         /* Copy the address. */
 544         if (sin) {
 545                 sin->sin_family = AF_INET;
 546                 sin->sin_addr.s_addr = ip_hdr(skb)->saddr;
 547                 sin->sin_port = 0;
 548                 memset(&sin->sin_zero, 0, sizeof(sin->sin_zero));
 549                 *addr_len = sizeof(*sin);
 550         }
 551         if (inet->cmsg_flags)
 552                 ip_cmsg_recv(msg, skb);
 553         if (flags & MSG_TRUNC)
 554                 copied = skb->len;
 555 done:
 556         skb_free_datagram(sk, skb);
 557 out:
 558         return err ? err : copied;
 559 }
 560
 561 int l2tp_ioctl(struct sock *sk, int cmd, unsigned long arg)
 562 {
 563         struct sk_buff *skb;
 564         int amount;
 565
 566         switch (cmd) {
 567         case SIOCOUTQ:
 568                 amount = sk_wmem_alloc_get(sk);
 569                 break;
 570         case SIOCINQ:
 571                 spin_lock_bh(&sk->sk_receive_queue.lock);
 572                 skb = skb_peek(&sk->sk_receive_queue);
 573                 amount = skb ? skb->len : 0;
 574                 spin_unlock_bh(&sk->sk_receive_queue.lock);
 575                 break;
 576
 577         default:
 578                 return -ENOIOCTLCMD;
 579         }
 580
 581         return put_user(amount, (int __user *)arg);
 582 }
 583 EXPORT_SYMBOL(l2tp_ioctl);
 584
 585 static struct proto l2tp_ip_prot = {
 586         .name              = "L2TP/IP",
 587         .owner             = THIS_MODULE,
 588         .init              = l2tp_ip_open,
 589         .close             = l2tp_ip_close,
 590         .bind              = l2tp_ip_bind,
 591         .connect           = l2tp_ip_connect,
 592         .disconnect        = l2tp_ip_disconnect,
 593         .ioctl             = l2tp_ioctl,
 594         .destroy           = l2tp_ip_destroy_sock,
 595         .setsockopt        = ip_setsockopt,
 596         .getsockopt        = ip_getsockopt,
 597         .sendmsg           = l2tp_ip_sendmsg,
 598         .recvmsg           = l2tp_ip_recvmsg,
 599         .backlog_rcv       = l2tp_ip_backlog_recv,
 600         .hash              = inet_hash,
 601         .unhash            = inet_unhash,
 602         .obj_size          = sizeof(struct l2tp_ip_sock),
 603 #ifdef CONFIG_COMPAT
 604         .compat_setsockopt = compat_ip_setsockopt,
 605         .compat_getsockopt = compat_ip_getsockopt,
 606 #endif
 607 };
 608
 609 static const struct proto_ops l2tp_ip_ops = {
 610         .family            = PF_INET,
 611         .owner             = THIS_MODULE,
 612         .release           = inet_release,
 613         .bind              = inet_bind,
 614         .connect           = inet_dgram_connect,
 615         .socketpair        = sock_no_socketpair,
 616         .accept            = sock_no_accept,
 617         .getname           = l2tp_ip_getname,
 618         .poll              = datagram_poll,
 619         .ioctl             = inet_ioctl,
 620         .listen            = sock_no_listen,
 621         .shutdown          = inet_shutdown,
 622         .setsockopt        = sock_common_setsockopt,
 623         .getsockopt        = sock_common_getsockopt,
 624         .sendmsg           = inet_sendmsg,
 625         .recvmsg           = sock_common_recvmsg,
 626         .mmap              = sock_no_mmap,
 627         .sendpage          = sock_no_sendpage,
 628 #ifdef CONFIG_COMPAT
 629         .compat_setsockopt = compat_sock_common_setsockopt,
 630         .compat_getsockopt = compat_sock_common_getsockopt,
 631 #endif
 632 };
 633
 634 static struct inet_protosw l2tp_ip_protosw = {
 635         .type           = SOCK_DGRAM,
 636         .protocol       = IPPROTO_L2TP,
 637         .prot           = &l2tp_ip_prot,
 638         .ops            = &l2tp_ip_ops,
 639 };
 640
 641 static struct net_protocol l2tp_ip_protocol __read_mostly = {
 642         .handler        = l2tp_ip_recv,
 643         .netns_ok       = 1,
 644 };
 645
 646 static int __init l2tp_ip_init(void)
 647 {
 648         int err;
 649
 650         pr_info("L2TP IP encapsulation support (L2TPv3)\n");
 651
 652         err = proto_register(&l2tp_ip_prot, 1);
 653         if (err != 0)
 654                 goto out;
 655
 656         err = inet_add_protocol(&l2tp_ip_protocol, IPPROTO_L2TP);
 657         if (err)
 658                 goto out1;
 659
 660         inet_register_protosw(&l2tp_ip_protosw);
 661         return 0;
 662
 663 out1:
 664         proto_unregister(&l2tp_ip_prot);
 665 out:
 666         return err;
 667 }
 668
 669 static void __exit l2tp_ip_exit(void)
 670 {
 671         inet_unregister_protosw(&l2tp_ip_protosw);
 672         inet_del_protocol(&l2tp_ip_protocol, IPPROTO_L2TP);
 673         proto_unregister(&l2tp_ip_prot);
 674 }
 675
 676 module_init(l2tp_ip_init);
 677 module_exit(l2tp_ip_exit);
 678
 679 MODULE_LICENSE("GPL");
 680 MODULE_AUTHOR("James Chapman <jchapman@katalix.com>");
 681 MODULE_DESCRIPTION("L2TP over IP");
 682 MODULE_VERSION("1.0");
 683
 684 /* Use the value of SOCK_DGRAM (2) directory, because __stringify doesn't like
 685  * enums
 686  */
 687 MODULE_ALIAS_NET_PF_PROTO_TYPE(PF_INET, 2, IPPROTO_L2TP);
 688 MODULE_ALIAS_NET_PF_PROTO(PF_INET, IPPROTO_L2TP);