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                 struct inet_sock *inet = inet_sk(sk);
  58                 struct l2tp_ip_sock *l2tp = l2tp_ip_sk(sk);
  59
  60                 if (l2tp == NULL)
  61                         continue;
  62
  63                 if ((l2tp->conn_id == tunnel_id) &&
  64                     net_eq(sock_net(sk), net) &&
  65                     !(inet->inet_rcv_saddr && inet->inet_rcv_saddr != laddr) &&
  66                     (!inet->inet_daddr || !raddr || inet->inet_daddr == raddr) &&
  67                     (!sk->sk_bound_dev_if || !dif ||
  68                      sk->sk_bound_dev_if == dif))
  69                         goto found;
  70         }
  71
  72         sk = NULL;
  73 found:
  74         return sk;
  75 }
  76
  77 /* When processing receive frames, there are two cases to
  78  * consider. Data frames consist of a non-zero session-id and an
  79  * optional cookie. Control frames consist of a regular L2TP header
  80  * preceded by 32-bits of zeros.
  81  *
  82  * L2TPv3 Session Header Over IP
  83  *
  84  *  0                   1                   2                   3
  85  *  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
  86  * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
  87  * |                           Session ID                          |
  88  * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
  89  * |               Cookie (optional, maximum 64 bits)...
  90  * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
  91  *                                                                 |
  92  * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
  93  *
  94  * L2TPv3 Control Message Header Over IP
  95  *
  96  *  0                   1                   2                   3
  97  *  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
  98  * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
  99  * |                      (32 bits of zeros)                       |
 100  * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 101  * |T|L|x|x|S|x|x|x|x|x|x|x|  Ver  |             Length            |
 102  * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 103  * |                     Control Connection ID                     |
 104  * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 105  * |               Ns              |               Nr              |
 106  * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 107  *
 108  * All control frames are passed to userspace.
 109  */
 110 static int l2tp_ip_recv(struct sk_buff *skb)
 111 {
 112         struct net *net = dev_net(skb->dev);
 113         struct sock *sk;
 114         u32 session_id;
 115         u32 tunnel_id;
 116         unsigned char *ptr, *optr;
 117         struct l2tp_session *session;
 118         struct l2tp_tunnel *tunnel = NULL;
 119         int length;
 120
 121         if (!pskb_may_pull(skb, 4))
 122                 goto discard;
 123
 124         /* Point to L2TP header */
 125         optr = ptr = skb->data;
 126         session_id = ntohl(*((__be32 *) ptr));
 127         ptr += 4;
 128
 129         /* RFC3931: L2TP/IP packets have the first 4 bytes containing
 130          * the session_id. If it is 0, the packet is a L2TP control
 131          * frame and the session_id value can be discarded.
 132          */
 133         if (session_id == 0) {
 134                 __skb_pull(skb, 4);
 135                 goto pass_up;
 136         }
 137
 138         /* Ok, this is a data packet. Lookup the session. */
 139         session = l2tp_session_find(net, NULL, session_id);
 140         if (session == NULL)
 141                 goto discard;
 142
 143         tunnel = session->tunnel;
 144         if (tunnel == NULL)
 145                 goto discard;
 146
 147         /* Trace packet contents, if enabled */
 148         if (tunnel->debug & L2TP_MSG_DATA) {
 149                 length = min(32u, skb->len);
 150                 if (!pskb_may_pull(skb, length))
 151                         goto discard;
 152
 153                 /* Point to L2TP header */
 154                 optr = ptr = skb->data;
 155                 ptr += 4;
 156                 pr_debug("%s: ip recv\n", tunnel->name);
 157                 print_hex_dump_bytes("", DUMP_PREFIX_OFFSET, ptr, length);
 158         }
 159
 160         l2tp_recv_common(session, skb, ptr, optr, 0, skb->len, tunnel->recv_payload_hook);
 161
 162         return 0;
 163
 164 pass_up:
 165         /* Get the tunnel_id from the L2TP header */
 166         if (!pskb_may_pull(skb, 12))
 167                 goto discard;
 168
 169         if ((skb->data[0] & 0xc0) != 0xc0)
 170                 goto discard;
 171
 172         tunnel_id = ntohl(*(__be32 *) &skb->data[4]);
 173         tunnel = l2tp_tunnel_find(net, tunnel_id);
 174         if (tunnel != NULL)
 175                 sk = tunnel->sock;
 176         else {
 177                 struct iphdr *iph = (struct iphdr *) skb_network_header(skb);
 178
 179                 read_lock_bh(&l2tp_ip_lock);
 180                 sk = __l2tp_ip_bind_lookup(net, iph->daddr, iph->saddr,
 181                                            inet_iif(skb), tunnel_id);
 182                 if (!sk) {
 183                         read_unlock_bh(&l2tp_ip_lock);
 184                         goto discard;
 185                 }
 186
 187                 sock_hold(sk);
 188                 read_unlock_bh(&l2tp_ip_lock);
 189         }
 190
 191         if (!xfrm4_policy_check(sk, XFRM_POLICY_IN, skb))
 192                 goto discard_put;
 193
 194         nf_reset(skb);
 195
 196         return sk_receive_skb(sk, skb, 1);
 197
 198 discard_put:
 199         sock_put(sk);
 200
 201 discard:
 202         kfree_skb(skb);
 203         return 0;
 204 }
 205
 206 static int l2tp_ip_open(struct sock *sk)
 207 {
 208         /* Prevent autobind. We don't have ports. */
 209         inet_sk(sk)->inet_num = IPPROTO_L2TP;
 210
 211         write_lock_bh(&l2tp_ip_lock);
 212         sk_add_node(sk, &l2tp_ip_table);
 213         write_unlock_bh(&l2tp_ip_lock);
 214
 215         return 0;
 216 }
 217
 218 static void l2tp_ip_close(struct sock *sk, long timeout)
 219 {
 220         write_lock_bh(&l2tp_ip_lock);
 221         hlist_del_init(&sk->sk_bind_node);
 222         sk_del_node_init(sk);
 223         write_unlock_bh(&l2tp_ip_lock);
 224         sk_common_release(sk);
 225 }
 226
 227 static void l2tp_ip_destroy_sock(struct sock *sk)
 228 {
 229         struct sk_buff *skb;
 230         struct l2tp_tunnel *tunnel = l2tp_sock_to_tunnel(sk);
 231
 232         while ((skb = __skb_dequeue_tail(&sk->sk_write_queue)) != NULL)
 233                 kfree_skb(skb);
 234
 235         if (tunnel) {
 236                 l2tp_tunnel_closeall(tunnel);
 237                 sock_put(sk);
 238         }
 239
 240         sk_refcnt_debug_dec(sk);
 241 }
 242
 243 static int l2tp_ip_bind(struct sock *sk, struct sockaddr *uaddr, int addr_len)
 244 {
 245         struct inet_sock *inet = inet_sk(sk);
 246         struct sockaddr_l2tpip *addr = (struct sockaddr_l2tpip *) uaddr;
 247         struct net *net = sock_net(sk);
 248         int ret;
 249         int chk_addr_ret;
 250
 251         if (addr_len < sizeof(struct sockaddr_l2tpip))
 252                 return -EINVAL;
 253         if (addr->l2tp_family != AF_INET)
 254                 return -EINVAL;
 255
 256         lock_sock(sk);
 257
 258         ret = -EINVAL;
 259         if (!sock_flag(sk, SOCK_ZAPPED))
 260                 goto out;
 261
 262         if (sk->sk_state != TCP_CLOSE || addr_len < sizeof(struct sockaddr_l2tpip))
 263                 goto out;
 264
 265         chk_addr_ret = inet_addr_type(net, addr->l2tp_addr.s_addr);
 266         ret = -EADDRNOTAVAIL;
 267         if (addr->l2tp_addr.s_addr && chk_addr_ret != RTN_LOCAL &&
 268             chk_addr_ret != RTN_MULTICAST && chk_addr_ret != RTN_BROADCAST)
 269                 goto out;
 270
 271         if (addr->l2tp_addr.s_addr)
 272                 inet->inet_rcv_saddr = inet->inet_saddr = addr->l2tp_addr.s_addr;
 273         if (chk_addr_ret == RTN_MULTICAST || chk_addr_ret == RTN_BROADCAST)
 274                 inet->inet_saddr = 0;  /* Use device */
 275
 276         write_lock_bh(&l2tp_ip_lock);
 277         if (__l2tp_ip_bind_lookup(net, addr->l2tp_addr.s_addr, 0,
 278                                   sk->sk_bound_dev_if, addr->l2tp_conn_id)) {
 279                 write_unlock_bh(&l2tp_ip_lock);
 280                 ret = -EADDRINUSE;
 281                 goto out;
 282         }
 283
 284         sk_dst_reset(sk);
 285         l2tp_ip_sk(sk)->conn_id = addr->l2tp_conn_id;
 286
 287         sk_add_bind_node(sk, &l2tp_ip_bind_table);
 288         sk_del_node_init(sk);
 289         write_unlock_bh(&l2tp_ip_lock);
 290
 291         ret = 0;
 292         sock_reset_flag(sk, SOCK_ZAPPED);
 293
 294 out:
 295         release_sock(sk);
 296
 297         return ret;
 298 }
 299
 300 static int l2tp_ip_connect(struct sock *sk, struct sockaddr *uaddr, int addr_len)
 301 {
 302         struct sockaddr_l2tpip *lsa = (struct sockaddr_l2tpip *) uaddr;
 303         int rc;
 304
 305         if (addr_len < sizeof(*lsa))
 306                 return -EINVAL;
 307
 308         if (ipv4_is_multicast(lsa->l2tp_addr.s_addr))
 309                 return -EINVAL;
 310
 311         lock_sock(sk);
 312
 313         /* Must bind first - autobinding does not work */
 314         if (sock_flag(sk, SOCK_ZAPPED)) {
 315                 rc = -EINVAL;
 316                 goto out_sk;
 317         }
 318
 319         rc = __ip4_datagram_connect(sk, uaddr, addr_len);
 320         if (rc < 0)
 321                 goto out_sk;
 322
 323         l2tp_ip_sk(sk)->peer_conn_id = lsa->l2tp_conn_id;
 324
 325         write_lock_bh(&l2tp_ip_lock);
 326         hlist_del_init(&sk->sk_bind_node);
 327         sk_add_bind_node(sk, &l2tp_ip_bind_table);
 328         write_unlock_bh(&l2tp_ip_lock);
 329
 330 out_sk:
 331         release_sock(sk);
 332
 333         return rc;
 334 }
 335
 336 static int l2tp_ip_disconnect(struct sock *sk, int flags)
 337 {
 338         if (sock_flag(sk, SOCK_ZAPPED))
 339                 return 0;
 340
 341         return __udp_disconnect(sk, flags);
 342 }
 343
 344 static int l2tp_ip_getname(struct socket *sock, struct sockaddr *uaddr,
 345                            int *uaddr_len, int peer)
 346 {
 347         struct sock *sk         = sock->sk;
 348         struct inet_sock *inet  = inet_sk(sk);
 349         struct l2tp_ip_sock *lsk = l2tp_ip_sk(sk);
 350         struct sockaddr_l2tpip *lsa = (struct sockaddr_l2tpip *)uaddr;
 351
 352         memset(lsa, 0, sizeof(*lsa));
 353         lsa->l2tp_family = AF_INET;
 354         if (peer) {
 355                 if (!inet->inet_dport)
 356                         return -ENOTCONN;
 357                 lsa->l2tp_conn_id = lsk->peer_conn_id;
 358                 lsa->l2tp_addr.s_addr = inet->inet_daddr;
 359         } else {
 360                 __be32 addr = inet->inet_rcv_saddr;
 361                 if (!addr)
 362                         addr = inet->inet_saddr;
 363                 lsa->l2tp_conn_id = lsk->conn_id;
 364                 lsa->l2tp_addr.s_addr = addr;
 365         }
 366         *uaddr_len = sizeof(*lsa);
 367         return 0;
 368 }
 369
 370 static int l2tp_ip_backlog_recv(struct sock *sk, struct sk_buff *skb)
 371 {
 372         int rc;
 373
 374         /* Charge it to the socket, dropping if the queue is full. */
 375         rc = sock_queue_rcv_skb(sk, skb);
 376         if (rc < 0)
 377                 goto drop;
 378
 379         return 0;
 380
 381 drop:
 382         IP_INC_STATS(sock_net(sk), IPSTATS_MIB_INDISCARDS);
 383         kfree_skb(skb);
 384         return -1;
 385 }
 386
 387 /* Userspace will call sendmsg() on the tunnel socket to send L2TP
 388  * control frames.
 389  */
 390 static int l2tp_ip_sendmsg(struct sock *sk, struct msghdr *msg, size_t len)
 391 {
 392         struct sk_buff *skb;
 393         int rc;
 394         struct inet_sock *inet = inet_sk(sk);
 395         struct rtable *rt = NULL;
 396         struct flowi4 *fl4;
 397         int connected = 0;
 398         __be32 daddr;
 399
 400         lock_sock(sk);
 401
 402         rc = -ENOTCONN;
 403         if (sock_flag(sk, SOCK_DEAD))
 404                 goto out;
 405
 406         /* Get and verify the address. */
 407         if (msg->msg_name) {
 408                 DECLARE_SOCKADDR(struct sockaddr_l2tpip *, lip, msg->msg_name);
 409                 rc = -EINVAL;
 410                 if (msg->msg_namelen < sizeof(*lip))
 411                         goto out;
 412
 413                 if (lip->l2tp_family != AF_INET) {
 414                         rc = -EAFNOSUPPORT;
 415                         if (lip->l2tp_family != AF_UNSPEC)
 416                                 goto out;
 417                 }
 418
 419                 daddr = lip->l2tp_addr.s_addr;
 420         } else {
 421                 rc = -EDESTADDRREQ;
 422                 if (sk->sk_state != TCP_ESTABLISHED)
 423                         goto out;
 424
 425                 daddr = inet->inet_daddr;
 426                 connected = 1;
 427         }
 428
 429         /* Allocate a socket buffer */
 430         rc = -ENOMEM;
 431         skb = sock_wmalloc(sk, 2 + NET_SKB_PAD + sizeof(struct iphdr) +
 432                            4 + len, 0, GFP_KERNEL);
 433         if (!skb)
 434                 goto error;
 435
 436         /* Reserve space for headers, putting IP header on 4-byte boundary. */
 437         skb_reserve(skb, 2 + NET_SKB_PAD);
 438         skb_reset_network_header(skb);
 439         skb_reserve(skb, sizeof(struct iphdr));
 440         skb_reset_transport_header(skb);
 441
 442         /* Insert 0 session_id */
 443         *((__be32 *) skb_put(skb, 4)) = 0;
 444
 445         /* Copy user data into skb */
 446         rc = memcpy_from_msg(skb_put(skb, len), msg, len);
 447         if (rc < 0) {
 448                 kfree_skb(skb);
 449                 goto error;
 450         }
 451
 452         fl4 = &inet->cork.fl.u.ip4;
 453         if (connected)
 454                 rt = (struct rtable *) __sk_dst_check(sk, 0);
 455
 456         rcu_read_lock();
 457         if (rt == NULL) {
 458                 const struct ip_options_rcu *inet_opt;
 459
 460                 inet_opt = rcu_dereference(inet->inet_opt);
 461
 462                 /* Use correct destination address if we have options. */
 463                 if (inet_opt && inet_opt->opt.srr)
 464                         daddr = inet_opt->opt.faddr;
 465
 466                 /* If this fails, retransmit mechanism of transport layer will
 467                  * keep trying until route appears or the connection times
 468                  * itself out.
 469                  */
 470                 rt = ip_route_output_ports(sock_net(sk), fl4, sk,
 471                                            daddr, inet->inet_saddr,
 472                                            inet->inet_dport, inet->inet_sport,
 473                                            sk->sk_protocol, RT_CONN_FLAGS(sk),
 474                                            sk->sk_bound_dev_if);
 475                 if (IS_ERR(rt))
 476                         goto no_route;
 477                 if (connected) {
 478                         sk_setup_caps(sk, &rt->dst);
 479                 } else {
 480                         skb_dst_set(skb, &rt->dst);
 481                         goto xmit;
 482                 }
 483         }
 484
 485         /* We dont need to clone dst here, it is guaranteed to not disappear.
 486          *  __dev_xmit_skb() might force a refcount if needed.
 487          */
 488         skb_dst_set_noref(skb, &rt->dst);
 489
 490 xmit:
 491         /* Queue the packet to IP for output */
 492         rc = ip_queue_xmit(sk, skb, &inet->cork.fl);
 493         rcu_read_unlock();
 494
 495 error:
 496         if (rc >= 0)
 497                 rc = len;
 498
 499 out:
 500         release_sock(sk);
 501         return rc;
 502
 503 no_route:
 504         rcu_read_unlock();
 505         IP_INC_STATS(sock_net(sk), IPSTATS_MIB_OUTNOROUTES);
 506         kfree_skb(skb);
 507         rc = -EHOSTUNREACH;
 508         goto out;
 509 }
 510
 511 static int l2tp_ip_recvmsg(struct sock *sk, struct msghdr *msg,
 512                            size_t len, int noblock, int flags, int *addr_len)
 513 {
 514         struct inet_sock *inet = inet_sk(sk);
 515         size_t copied = 0;
 516         int err = -EOPNOTSUPP;
 517         DECLARE_SOCKADDR(struct sockaddr_in *, sin, msg->msg_name);
 518         struct sk_buff *skb;
 519
 520         if (flags & MSG_OOB)
 521                 goto out;
 522
 523         skb = skb_recv_datagram(sk, flags, noblock, &err);
 524         if (!skb)
 525                 goto out;
 526
 527         copied = skb->len;
 528         if (len < copied) {
 529                 msg->msg_flags |= MSG_TRUNC;
 530                 copied = len;
 531         }
 532
 533         err = skb_copy_datagram_msg(skb, 0, msg, copied);
 534         if (err)
 535                 goto done;
 536
 537         sock_recv_timestamp(msg, sk, skb);
 538
 539         /* Copy the address. */
 540         if (sin) {
 541                 sin->sin_family = AF_INET;
 542                 sin->sin_addr.s_addr = ip_hdr(skb)->saddr;
 543                 sin->sin_port = 0;
 544                 memset(&sin->sin_zero, 0, sizeof(sin->sin_zero));
 545                 *addr_len = sizeof(*sin);
 546         }
 547         if (inet->cmsg_flags)
 548                 ip_cmsg_recv(msg, skb);
 549         if (flags & MSG_TRUNC)
 550                 copied = skb->len;
 551 done:
 552         skb_free_datagram(sk, skb);
 553 out:
 554         return err ? err : copied;
 555 }
 556
 557 int l2tp_ioctl(struct sock *sk, int cmd, unsigned long arg)
 558 {
 559         struct sk_buff *skb;
 560         int amount;
 561
 562         switch (cmd) {
 563         case SIOCOUTQ:
 564                 amount = sk_wmem_alloc_get(sk);
 565                 break;
 566         case SIOCINQ:
 567                 spin_lock_bh(&sk->sk_receive_queue.lock);
 568                 skb = skb_peek(&sk->sk_receive_queue);
 569                 amount = skb ? skb->len : 0;
 570                 spin_unlock_bh(&sk->sk_receive_queue.lock);
 571                 break;
 572
 573         default:
 574                 return -ENOIOCTLCMD;
 575         }
 576
 577         return put_user(amount, (int __user *)arg);
 578 }
 579 EXPORT_SYMBOL(l2tp_ioctl);
 580
 581 static 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        = l2tp_ip_disconnect,
 589         .ioctl             = l2tp_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 };
 636
 637 static struct net_protocol l2tp_ip_protocol __read_mostly = {
 638         .handler        = l2tp_ip_recv,
 639         .netns_ok       = 1,
 640 };
 641
 642 static int __init l2tp_ip_init(void)
 643 {
 644         int err;
 645
 646         pr_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
 680 /* Use the value of SOCK_DGRAM (2) directory, because __stringify doesn't like
 681  * enums
 682  */
 683 MODULE_ALIAS_NET_PF_PROTO_TYPE(PF_INET, 2, IPPROTO_L2TP);
 684 MODULE_ALIAS_NET_PF_PROTO(PF_INET, IPPROTO_L2TP);