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_get(net, NULL, session_id, true);
 147         if (!session)
 148                 goto discard;
 149
 150         tunnel = session->tunnel;
 151         if (!tunnel)
 152                 goto discard_sess;
 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_sess;
 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         l2tp_session_dec_refcount(session);
 169
 170         return 0;
 171
 172 pass_up:
 173         /* Get the tunnel_id from the L2TP header */
 174         if (!pskb_may_pull(skb, 12))
 175                 goto discard;
 176
 177         if ((skb->data[0] & 0xc0) != 0xc0)
 178                 goto discard;
 179
 180         tunnel_id = ntohl(*(__be32 *) &skb->data[4]);
 181         tunnel = l2tp_tunnel_find(net, tunnel_id);
 182         if (tunnel) {
 183                 sk = tunnel->sock;
 184                 sock_hold(sk);
 185         } else {
 186                 struct iphdr *iph = (struct iphdr *) skb_network_header(skb);
 187
 188                 read_lock_bh(&l2tp_ip_lock);
 189                 sk = __l2tp_ip_bind_lookup(net, iph->daddr, iph->saddr,
 190                                            inet_iif(skb), tunnel_id);
 191                 if (!sk) {
 192                         read_unlock_bh(&l2tp_ip_lock);
 193                         goto discard;
 194                 }
 195
 196                 sock_hold(sk);
 197                 read_unlock_bh(&l2tp_ip_lock);
 198         }
 199
 200         if (!xfrm4_policy_check(sk, XFRM_POLICY_IN, skb))
 201                 goto discard_put;
 202
 203         nf_reset(skb);
 204
 205         return sk_receive_skb(sk, skb, 1);
 206
 207 discard_sess:
 208         if (session->deref)
 209                 session->deref(session);
 210         l2tp_session_dec_refcount(session);
 211         goto discard;
 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         sk_del_node_init(sk);
 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         struct l2tp_tunnel *tunnel = l2tp_sock_to_tunnel(sk);
 246
 247         while ((skb = __skb_dequeue_tail(&sk->sk_write_queue)) != NULL)
 248                 kfree_skb(skb);
 249
 250         if (tunnel) {
 251                 l2tp_tunnel_closeall(tunnel);
 252                 sock_put(sk);
 253         }
 254
 255         sk_refcnt_debug_dec(sk);
 256 }
 257
 258 static int l2tp_ip_bind(struct sock *sk, struct sockaddr *uaddr, int addr_len)
 259 {
 260         struct inet_sock *inet = inet_sk(sk);
 261         struct sockaddr_l2tpip *addr = (struct sockaddr_l2tpip *) uaddr;
 262         struct net *net = sock_net(sk);
 263         int ret;
 264         int chk_addr_ret;
 265
 266         if (addr_len < sizeof(struct sockaddr_l2tpip))
 267                 return -EINVAL;
 268         if (addr->l2tp_family != AF_INET)
 269                 return -EINVAL;
 270
 271         lock_sock(sk);
 272
 273         ret = -EINVAL;
 274         if (!sock_flag(sk, SOCK_ZAPPED))
 275                 goto out;
 276
 277         if (sk->sk_state != TCP_CLOSE)
 278                 goto out;
 279
 280         chk_addr_ret = inet_addr_type(net, addr->l2tp_addr.s_addr);
 281         ret = -EADDRNOTAVAIL;
 282         if (addr->l2tp_addr.s_addr && chk_addr_ret != RTN_LOCAL &&
 283             chk_addr_ret != RTN_MULTICAST && chk_addr_ret != RTN_BROADCAST)
 284                 goto out;
 285
 286         if (addr->l2tp_addr.s_addr)
 287                 inet->inet_rcv_saddr = inet->inet_saddr = addr->l2tp_addr.s_addr;
 288         if (chk_addr_ret == RTN_MULTICAST || chk_addr_ret == RTN_BROADCAST)
 289                 inet->inet_saddr = 0;  /* Use device */
 290
 291         write_lock_bh(&l2tp_ip_lock);
 292         if (__l2tp_ip_bind_lookup(net, addr->l2tp_addr.s_addr, 0,
 293                                   sk->sk_bound_dev_if, addr->l2tp_conn_id)) {
 294                 write_unlock_bh(&l2tp_ip_lock);
 295                 ret = -EADDRINUSE;
 296                 goto out;
 297         }
 298
 299         sk_dst_reset(sk);
 300         l2tp_ip_sk(sk)->conn_id = addr->l2tp_conn_id;
 301
 302         sk_add_bind_node(sk, &l2tp_ip_bind_table);
 303         sk_del_node_init(sk);
 304         write_unlock_bh(&l2tp_ip_lock);
 305
 306         ret = 0;
 307         sock_reset_flag(sk, SOCK_ZAPPED);
 308
 309 out:
 310         release_sock(sk);
 311
 312         return ret;
 313 }
 314
 315 static int l2tp_ip_connect(struct sock *sk, struct sockaddr *uaddr, int addr_len)
 316 {
 317         struct sockaddr_l2tpip *lsa = (struct sockaddr_l2tpip *) uaddr;
 318         int rc;
 319
 320         if (addr_len < sizeof(*lsa))
 321                 return -EINVAL;
 322
 323         if (ipv4_is_multicast(lsa->l2tp_addr.s_addr))
 324                 return -EINVAL;
 325
 326         lock_sock(sk);
 327
 328         /* Must bind first - autobinding does not work */
 329         if (sock_flag(sk, SOCK_ZAPPED)) {
 330                 rc = -EINVAL;
 331                 goto out_sk;
 332         }
 333
 334         rc = __ip4_datagram_connect(sk, uaddr, addr_len);
 335         if (rc < 0)
 336                 goto out_sk;
 337
 338         l2tp_ip_sk(sk)->peer_conn_id = lsa->l2tp_conn_id;
 339
 340         write_lock_bh(&l2tp_ip_lock);
 341         hlist_del_init(&sk->sk_bind_node);
 342         sk_add_bind_node(sk, &l2tp_ip_bind_table);
 343         write_unlock_bh(&l2tp_ip_lock);
 344
 345 out_sk:
 346         release_sock(sk);
 347
 348         return rc;
 349 }
 350
 351 static int l2tp_ip_disconnect(struct sock *sk, int flags)
 352 {
 353         if (sock_flag(sk, SOCK_ZAPPED))
 354                 return 0;
 355
 356         return __udp_disconnect(sk, flags);
 357 }
 358
 359 static int l2tp_ip_getname(struct socket *sock, struct sockaddr *uaddr,
 360                            int *uaddr_len, int peer)
 361 {
 362         struct sock *sk         = sock->sk;
 363         struct inet_sock *inet  = inet_sk(sk);
 364         struct l2tp_ip_sock *lsk = l2tp_ip_sk(sk);
 365         struct sockaddr_l2tpip *lsa = (struct sockaddr_l2tpip *)uaddr;
 366
 367         memset(lsa, 0, sizeof(*lsa));
 368         lsa->l2tp_family = AF_INET;
 369         if (peer) {
 370                 if (!inet->inet_dport)
 371                         return -ENOTCONN;
 372                 lsa->l2tp_conn_id = lsk->peer_conn_id;
 373                 lsa->l2tp_addr.s_addr = inet->inet_daddr;
 374         } else {
 375                 __be32 addr = inet->inet_rcv_saddr;
 376                 if (!addr)
 377                         addr = inet->inet_saddr;
 378                 lsa->l2tp_conn_id = lsk->conn_id;
 379                 lsa->l2tp_addr.s_addr = addr;
 380         }
 381         *uaddr_len = sizeof(*lsa);
 382         return 0;
 383 }
 384
 385 static int l2tp_ip_backlog_recv(struct sock *sk, struct sk_buff *skb)
 386 {
 387         int rc;
 388
 389         /* Charge it to the socket, dropping if the queue is full. */
 390         rc = sock_queue_rcv_skb(sk, skb);
 391         if (rc < 0)
 392                 goto drop;
 393
 394         return 0;
 395
 396 drop:
 397         IP_INC_STATS(sock_net(sk), IPSTATS_MIB_INDISCARDS);
 398         kfree_skb(skb);
 399         return 0;
 400 }
 401
 402 /* Userspace will call sendmsg() on the tunnel socket to send L2TP
 403  * control frames.
 404  */
 405 static int l2tp_ip_sendmsg(struct sock *sk, struct msghdr *msg, size_t len)
 406 {
 407         struct sk_buff *skb;
 408         int rc;
 409         struct inet_sock *inet = inet_sk(sk);
 410         struct rtable *rt = NULL;
 411         struct flowi4 *fl4;
 412         int connected = 0;
 413         __be32 daddr;
 414
 415         lock_sock(sk);
 416
 417         rc = -ENOTCONN;
 418         if (sock_flag(sk, SOCK_DEAD))
 419                 goto out;
 420
 421         /* Get and verify the address. */
 422         if (msg->msg_name) {
 423                 DECLARE_SOCKADDR(struct sockaddr_l2tpip *, lip, msg->msg_name);
 424                 rc = -EINVAL;
 425                 if (msg->msg_namelen < sizeof(*lip))
 426                         goto out;
 427
 428                 if (lip->l2tp_family != AF_INET) {
 429                         rc = -EAFNOSUPPORT;
 430                         if (lip->l2tp_family != AF_UNSPEC)
 431                                 goto out;
 432                 }
 433
 434                 daddr = lip->l2tp_addr.s_addr;
 435         } else {
 436                 rc = -EDESTADDRREQ;
 437                 if (sk->sk_state != TCP_ESTABLISHED)
 438                         goto out;
 439
 440                 daddr = inet->inet_daddr;
 441                 connected = 1;
 442         }
 443
 444         /* Allocate a socket buffer */
 445         rc = -ENOMEM;
 446         skb = sock_wmalloc(sk, 2 + NET_SKB_PAD + sizeof(struct iphdr) +
 447                            4 + len, 0, GFP_KERNEL);
 448         if (!skb)
 449                 goto error;
 450
 451         /* Reserve space for headers, putting IP header on 4-byte boundary. */
 452         skb_reserve(skb, 2 + NET_SKB_PAD);
 453         skb_reset_network_header(skb);
 454         skb_reserve(skb, sizeof(struct iphdr));
 455         skb_reset_transport_header(skb);
 456
 457         /* Insert 0 session_id */
 458         *((__be32 *) skb_put(skb, 4)) = 0;
 459
 460         /* Copy user data into skb */
 461         rc = memcpy_from_msg(skb_put(skb, len), msg, len);
 462         if (rc < 0) {
 463                 kfree_skb(skb);
 464                 goto error;
 465         }
 466
 467         fl4 = &inet->cork.fl.u.ip4;
 468         if (connected)
 469                 rt = (struct rtable *) __sk_dst_check(sk, 0);
 470
 471         rcu_read_lock();
 472         if (rt == NULL) {
 473                 const struct ip_options_rcu *inet_opt;
 474
 475                 inet_opt = rcu_dereference(inet->inet_opt);
 476
 477                 /* Use correct destination address if we have options. */
 478                 if (inet_opt && inet_opt->opt.srr)
 479                         daddr = inet_opt->opt.faddr;
 480
 481                 /* If this fails, retransmit mechanism of transport layer will
 482                  * keep trying until route appears or the connection times
 483                  * itself out.
 484                  */
 485                 rt = ip_route_output_ports(sock_net(sk), fl4, sk,
 486                                            daddr, inet->inet_saddr,
 487                                            inet->inet_dport, inet->inet_sport,
 488                                            sk->sk_protocol, RT_CONN_FLAGS(sk),
 489                                            sk->sk_bound_dev_if);
 490                 if (IS_ERR(rt))
 491                         goto no_route;
 492                 if (connected) {
 493                         sk_setup_caps(sk, &rt->dst);
 494                 } else {
 495                         skb_dst_set(skb, &rt->dst);
 496                         goto xmit;
 497                 }
 498         }
 499
 500         /* We dont need to clone dst here, it is guaranteed to not disappear.
 501          *  __dev_xmit_skb() might force a refcount if needed.
 502          */
 503         skb_dst_set_noref(skb, &rt->dst);
 504
 505 xmit:
 506         /* Queue the packet to IP for output */
 507         rc = ip_queue_xmit(sk, skb, &inet->cork.fl);
 508         rcu_read_unlock();
 509
 510 error:
 511         if (rc >= 0)
 512                 rc = len;
 513
 514 out:
 515         release_sock(sk);
 516         return rc;
 517
 518 no_route:
 519         rcu_read_unlock();
 520         IP_INC_STATS(sock_net(sk), IPSTATS_MIB_OUTNOROUTES);
 521         kfree_skb(skb);
 522         rc = -EHOSTUNREACH;
 523         goto out;
 524 }
 525
 526 static int l2tp_ip_recvmsg(struct sock *sk, struct msghdr *msg,
 527                            size_t len, int noblock, int flags, int *addr_len)
 528 {
 529         struct inet_sock *inet = inet_sk(sk);
 530         size_t copied = 0;
 531         int err = -EOPNOTSUPP;
 532         DECLARE_SOCKADDR(struct sockaddr_in *, sin, msg->msg_name);
 533         struct sk_buff *skb;
 534
 535         if (flags & MSG_OOB)
 536                 goto out;
 537
 538         skb = skb_recv_datagram(sk, flags, noblock, &err);
 539         if (!skb)
 540                 goto out;
 541
 542         copied = skb->len;
 543         if (len < copied) {
 544                 msg->msg_flags |= MSG_TRUNC;
 545                 copied = len;
 546         }
 547
 548         err = skb_copy_datagram_msg(skb, 0, msg, copied);
 549         if (err)
 550                 goto done;
 551
 552         sock_recv_timestamp(msg, sk, skb);
 553
 554         /* Copy the address. */
 555         if (sin) {
 556                 sin->sin_family = AF_INET;
 557                 sin->sin_addr.s_addr = ip_hdr(skb)->saddr;
 558                 sin->sin_port = 0;
 559                 memset(&sin->sin_zero, 0, sizeof(sin->sin_zero));
 560                 *addr_len = sizeof(*sin);
 561         }
 562         if (inet->cmsg_flags)
 563                 ip_cmsg_recv(msg, skb);
 564         if (flags & MSG_TRUNC)
 565                 copied = skb->len;
 566 done:
 567         skb_free_datagram(sk, skb);
 568 out:
 569         return err ? err : copied;
 570 }
 571
 572 int l2tp_ioctl(struct sock *sk, int cmd, unsigned long arg)
 573 {
 574         struct sk_buff *skb;
 575         int amount;
 576
 577         switch (cmd) {
 578         case SIOCOUTQ:
 579                 amount = sk_wmem_alloc_get(sk);
 580                 break;
 581         case SIOCINQ:
 582                 spin_lock_bh(&sk->sk_receive_queue.lock);
 583                 skb = skb_peek(&sk->sk_receive_queue);
 584                 amount = skb ? skb->len : 0;
 585                 spin_unlock_bh(&sk->sk_receive_queue.lock);
 586                 break;
 587
 588         default:
 589                 return -ENOIOCTLCMD;
 590         }
 591
 592         return put_user(amount, (int __user *)arg);
 593 }
 594 EXPORT_SYMBOL(l2tp_ioctl);
 595
 596 static struct proto l2tp_ip_prot = {
 597         .name              = "L2TP/IP",
 598         .owner             = THIS_MODULE,
 599         .init              = l2tp_ip_open,
 600         .close             = l2tp_ip_close,
 601         .bind              = l2tp_ip_bind,
 602         .connect           = l2tp_ip_connect,
 603         .disconnect        = l2tp_ip_disconnect,
 604         .ioctl             = l2tp_ioctl,
 605         .destroy           = l2tp_ip_destroy_sock,
 606         .setsockopt        = ip_setsockopt,
 607         .getsockopt        = ip_getsockopt,
 608         .sendmsg           = l2tp_ip_sendmsg,
 609         .recvmsg           = l2tp_ip_recvmsg,
 610         .backlog_rcv       = l2tp_ip_backlog_recv,
 611         .hash              = inet_hash,
 612         .unhash            = inet_unhash,
 613         .obj_size          = sizeof(struct l2tp_ip_sock),
 614 #ifdef CONFIG_COMPAT
 615         .compat_setsockopt = compat_ip_setsockopt,
 616         .compat_getsockopt = compat_ip_getsockopt,
 617 #endif
 618 };
 619
 620 static const struct proto_ops l2tp_ip_ops = {
 621         .family            = PF_INET,
 622         .owner             = THIS_MODULE,
 623         .release           = inet_release,
 624         .bind              = inet_bind,
 625         .connect           = inet_dgram_connect,
 626         .socketpair        = sock_no_socketpair,
 627         .accept            = sock_no_accept,
 628         .getname           = l2tp_ip_getname,
 629         .poll              = datagram_poll,
 630         .ioctl             = inet_ioctl,
 631         .listen            = sock_no_listen,
 632         .shutdown          = inet_shutdown,
 633         .setsockopt        = sock_common_setsockopt,
 634         .getsockopt        = sock_common_getsockopt,
 635         .sendmsg           = inet_sendmsg,
 636         .recvmsg           = sock_common_recvmsg,
 637         .mmap              = sock_no_mmap,
 638         .sendpage          = sock_no_sendpage,
 639 #ifdef CONFIG_COMPAT
 640         .compat_setsockopt = compat_sock_common_setsockopt,
 641         .compat_getsockopt = compat_sock_common_getsockopt,
 642 #endif
 643 };
 644
 645 static struct inet_protosw l2tp_ip_protosw = {
 646         .type           = SOCK_DGRAM,
 647         .protocol       = IPPROTO_L2TP,
 648         .prot           = &l2tp_ip_prot,
 649         .ops            = &l2tp_ip_ops,
 650 };
 651
 652 static struct net_protocol l2tp_ip_protocol __read_mostly = {
 653         .handler        = l2tp_ip_recv,
 654         .netns_ok       = 1,
 655 };
 656
 657 static int __init l2tp_ip_init(void)
 658 {
 659         int err;
 660
 661         pr_info("L2TP IP encapsulation support (L2TPv3)\n");
 662
 663         err = proto_register(&l2tp_ip_prot, 1);
 664         if (err != 0)
 665                 goto out;
 666
 667         err = inet_add_protocol(&l2tp_ip_protocol, IPPROTO_L2TP);
 668         if (err)
 669                 goto out1;
 670
 671         inet_register_protosw(&l2tp_ip_protosw);
 672         return 0;
 673
 674 out1:
 675         proto_unregister(&l2tp_ip_prot);
 676 out:
 677         return err;
 678 }
 679
 680 static void __exit l2tp_ip_exit(void)
 681 {
 682         inet_unregister_protosw(&l2tp_ip_protosw);
 683         inet_del_protocol(&l2tp_ip_protocol, IPPROTO_L2TP);
 684         proto_unregister(&l2tp_ip_prot);
 685 }
 686
 687 module_init(l2tp_ip_init);
 688 module_exit(l2tp_ip_exit);
 689
 690 MODULE_LICENSE("GPL");
 691 MODULE_AUTHOR("James Chapman <jchapman@katalix.com>");
 692 MODULE_DESCRIPTION("L2TP over IP");
 693 MODULE_VERSION("1.0");
 694
 695 /* Use the value of SOCK_DGRAM (2) directory, because __stringify doesn't like
 696  * enums
 697  */
 698 MODULE_ALIAS_NET_PF_PROTO_TYPE(PF_INET, 2, IPPROTO_L2TP);
 699 MODULE_ALIAS_NET_PF_PROTO(PF_INET, IPPROTO_L2TP);