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
l2tp_ip_sk(const struct sock * sk)46 static inline struct l2tp_ip_sock *l2tp_ip_sk(const struct sock *sk)
47 {
48 return (struct l2tp_ip_sock *)sk;
49 }
50
__l2tp_ip_bind_lookup(const struct net * net,__be32 laddr,__be32 raddr,int dif,u32 tunnel_id)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 */
l2tp_ip_recv(struct sk_buff * skb)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 struct iphdr *iph;
127 int length;
128
129 if (!pskb_may_pull(skb, 4))
130 goto discard;
131
132 /* Point to L2TP header */
133 optr = ptr = skb->data;
134 session_id = ntohl(*((__be32 *) ptr));
135 ptr += 4;
136
137 /* RFC3931: L2TP/IP packets have the first 4 bytes containing
138 * the session_id. If it is 0, the packet is a L2TP control
139 * frame and the session_id value can be discarded.
140 */
141 if (session_id == 0) {
142 __skb_pull(skb, 4);
143 goto pass_up;
144 }
145
146 /* Ok, this is a data packet. Lookup the session. */
147 session = l2tp_session_get(net, NULL, session_id, true);
148 if (!session)
149 goto discard;
150
151 tunnel = session->tunnel;
152 if (!tunnel)
153 goto discard_sess;
154
155 /* Trace packet contents, if enabled */
156 if (tunnel->debug & L2TP_MSG_DATA) {
157 length = min(32u, skb->len);
158 if (!pskb_may_pull(skb, length))
159 goto discard_sess;
160
161 /* Point to L2TP header */
162 optr = ptr = skb->data;
163 ptr += 4;
164 pr_debug("%s: ip recv\n", tunnel->name);
165 print_hex_dump_bytes("", DUMP_PREFIX_OFFSET, ptr, length);
166 }
167
168 if (l2tp_v3_ensure_opt_in_linear(session, skb, &ptr, &optr))
169 goto discard_sess;
170
171 l2tp_recv_common(session, skb, ptr, optr, 0, skb->len);
172 l2tp_session_dec_refcount(session);
173
174 return 0;
175
176 pass_up:
177 /* Get the tunnel_id from the L2TP header */
178 if (!pskb_may_pull(skb, 12))
179 goto discard;
180
181 if ((skb->data[0] & 0xc0) != 0xc0)
182 goto discard;
183
184 tunnel_id = ntohl(*(__be32 *) &skb->data[4]);
185 iph = (struct iphdr *)skb_network_header(skb);
186
187 read_lock_bh(&l2tp_ip_lock);
188 sk = __l2tp_ip_bind_lookup(net, iph->daddr, iph->saddr, inet_iif(skb),
189 tunnel_id);
190 if (!sk) {
191 read_unlock_bh(&l2tp_ip_lock);
192 goto discard;
193 }
194 sock_hold(sk);
195 read_unlock_bh(&l2tp_ip_lock);
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_sess:
205 if (session->deref)
206 session->deref(session);
207 l2tp_session_dec_refcount(session);
208 goto discard;
209
210 discard_put:
211 sock_put(sk);
212
213 discard:
214 kfree_skb(skb);
215 return 0;
216 }
217
l2tp_ip_open(struct sock * sk)218 static int l2tp_ip_open(struct sock *sk)
219 {
220 /* Prevent autobind. We don't have ports. */
221 inet_sk(sk)->inet_num = IPPROTO_L2TP;
222
223 write_lock_bh(&l2tp_ip_lock);
224 sk_add_node(sk, &l2tp_ip_table);
225 write_unlock_bh(&l2tp_ip_lock);
226
227 return 0;
228 }
229
l2tp_ip_close(struct sock * sk,long timeout)230 static void l2tp_ip_close(struct sock *sk, long timeout)
231 {
232 write_lock_bh(&l2tp_ip_lock);
233 hlist_del_init(&sk->sk_bind_node);
234 sk_del_node_init(sk);
235 write_unlock_bh(&l2tp_ip_lock);
236 sk_common_release(sk);
237 }
238
l2tp_ip_destroy_sock(struct sock * sk)239 static void l2tp_ip_destroy_sock(struct sock *sk)
240 {
241 struct sk_buff *skb;
242 struct l2tp_tunnel *tunnel = l2tp_sock_to_tunnel(sk);
243
244 while ((skb = __skb_dequeue_tail(&sk->sk_write_queue)) != NULL)
245 kfree_skb(skb);
246
247 if (tunnel) {
248 l2tp_tunnel_closeall(tunnel);
249 sock_put(sk);
250 }
251
252 sk_refcnt_debug_dec(sk);
253 }
254
l2tp_ip_bind(struct sock * sk,struct sockaddr * uaddr,int addr_len)255 static int l2tp_ip_bind(struct sock *sk, struct sockaddr *uaddr, int addr_len)
256 {
257 struct inet_sock *inet = inet_sk(sk);
258 struct sockaddr_l2tpip *addr = (struct sockaddr_l2tpip *) uaddr;
259 struct net *net = sock_net(sk);
260 int ret;
261 int chk_addr_ret;
262
263 if (addr_len < sizeof(struct sockaddr_l2tpip))
264 return -EINVAL;
265 if (addr->l2tp_family != AF_INET)
266 return -EINVAL;
267
268 lock_sock(sk);
269
270 ret = -EINVAL;
271 if (!sock_flag(sk, SOCK_ZAPPED))
272 goto out;
273
274 if (sk->sk_state != TCP_CLOSE)
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
288 write_lock_bh(&l2tp_ip_lock);
289 if (__l2tp_ip_bind_lookup(net, addr->l2tp_addr.s_addr, 0,
290 sk->sk_bound_dev_if, addr->l2tp_conn_id)) {
291 write_unlock_bh(&l2tp_ip_lock);
292 ret = -EADDRINUSE;
293 goto out;
294 }
295
296 sk_dst_reset(sk);
297 l2tp_ip_sk(sk)->conn_id = addr->l2tp_conn_id;
298
299 sk_add_bind_node(sk, &l2tp_ip_bind_table);
300 sk_del_node_init(sk);
301 write_unlock_bh(&l2tp_ip_lock);
302
303 ret = 0;
304 sock_reset_flag(sk, SOCK_ZAPPED);
305
306 out:
307 release_sock(sk);
308
309 return ret;
310 }
311
l2tp_ip_connect(struct sock * sk,struct sockaddr * uaddr,int addr_len)312 static int l2tp_ip_connect(struct sock *sk, struct sockaddr *uaddr, int addr_len)
313 {
314 struct sockaddr_l2tpip *lsa = (struct sockaddr_l2tpip *) uaddr;
315 int rc;
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 lock_sock(sk);
324
325 /* Must bind first - autobinding does not work */
326 if (sock_flag(sk, SOCK_ZAPPED)) {
327 rc = -EINVAL;
328 goto out_sk;
329 }
330
331 rc = __ip4_datagram_connect(sk, uaddr, addr_len);
332 if (rc < 0)
333 goto out_sk;
334
335 l2tp_ip_sk(sk)->peer_conn_id = lsa->l2tp_conn_id;
336
337 write_lock_bh(&l2tp_ip_lock);
338 hlist_del_init(&sk->sk_bind_node);
339 sk_add_bind_node(sk, &l2tp_ip_bind_table);
340 write_unlock_bh(&l2tp_ip_lock);
341
342 out_sk:
343 release_sock(sk);
344
345 return rc;
346 }
347
l2tp_ip_disconnect(struct sock * sk,int flags)348 static int l2tp_ip_disconnect(struct sock *sk, int flags)
349 {
350 if (sock_flag(sk, SOCK_ZAPPED))
351 return 0;
352
353 return __udp_disconnect(sk, flags);
354 }
355
l2tp_ip_getname(struct socket * sock,struct sockaddr * uaddr,int * uaddr_len,int peer)356 static int l2tp_ip_getname(struct socket *sock, struct sockaddr *uaddr,
357 int *uaddr_len, int peer)
358 {
359 struct sock *sk = sock->sk;
360 struct inet_sock *inet = inet_sk(sk);
361 struct l2tp_ip_sock *lsk = l2tp_ip_sk(sk);
362 struct sockaddr_l2tpip *lsa = (struct sockaddr_l2tpip *)uaddr;
363
364 memset(lsa, 0, sizeof(*lsa));
365 lsa->l2tp_family = AF_INET;
366 if (peer) {
367 if (!inet->inet_dport)
368 return -ENOTCONN;
369 lsa->l2tp_conn_id = lsk->peer_conn_id;
370 lsa->l2tp_addr.s_addr = inet->inet_daddr;
371 } else {
372 __be32 addr = inet->inet_rcv_saddr;
373 if (!addr)
374 addr = inet->inet_saddr;
375 lsa->l2tp_conn_id = lsk->conn_id;
376 lsa->l2tp_addr.s_addr = addr;
377 }
378 *uaddr_len = sizeof(*lsa);
379 return 0;
380 }
381
l2tp_ip_backlog_recv(struct sock * sk,struct sk_buff * skb)382 static int l2tp_ip_backlog_recv(struct sock *sk, struct sk_buff *skb)
383 {
384 int rc;
385
386 /* Charge it to the socket, dropping if the queue is full. */
387 rc = sock_queue_rcv_skb(sk, skb);
388 if (rc < 0)
389 goto drop;
390
391 return 0;
392
393 drop:
394 IP_INC_STATS(sock_net(sk), IPSTATS_MIB_INDISCARDS);
395 kfree_skb(skb);
396 return 0;
397 }
398
399 /* Userspace will call sendmsg() on the tunnel socket to send L2TP
400 * control frames.
401 */
l2tp_ip_sendmsg(struct sock * sk,struct msghdr * msg,size_t len)402 static int l2tp_ip_sendmsg(struct sock *sk, struct msghdr *msg, size_t len)
403 {
404 struct sk_buff *skb;
405 int rc;
406 struct inet_sock *inet = inet_sk(sk);
407 struct rtable *rt = NULL;
408 struct flowi4 *fl4;
409 int connected = 0;
410 __be32 daddr;
411
412 lock_sock(sk);
413
414 rc = -ENOTCONN;
415 if (sock_flag(sk, SOCK_DEAD))
416 goto out;
417
418 /* Get and verify the address. */
419 if (msg->msg_name) {
420 DECLARE_SOCKADDR(struct sockaddr_l2tpip *, lip, msg->msg_name);
421 rc = -EINVAL;
422 if (msg->msg_namelen < sizeof(*lip))
423 goto out;
424
425 if (lip->l2tp_family != AF_INET) {
426 rc = -EAFNOSUPPORT;
427 if (lip->l2tp_family != AF_UNSPEC)
428 goto out;
429 }
430
431 daddr = lip->l2tp_addr.s_addr;
432 } else {
433 rc = -EDESTADDRREQ;
434 if (sk->sk_state != TCP_ESTABLISHED)
435 goto out;
436
437 daddr = inet->inet_daddr;
438 connected = 1;
439 }
440
441 /* Allocate a socket buffer */
442 rc = -ENOMEM;
443 skb = sock_wmalloc(sk, 2 + NET_SKB_PAD + sizeof(struct iphdr) +
444 4 + len, 0, GFP_KERNEL);
445 if (!skb)
446 goto error;
447
448 /* Reserve space for headers, putting IP header on 4-byte boundary. */
449 skb_reserve(skb, 2 + NET_SKB_PAD);
450 skb_reset_network_header(skb);
451 skb_reserve(skb, sizeof(struct iphdr));
452 skb_reset_transport_header(skb);
453
454 /* Insert 0 session_id */
455 *((__be32 *) skb_put(skb, 4)) = 0;
456
457 /* Copy user data into skb */
458 rc = memcpy_from_msg(skb_put(skb, len), msg, len);
459 if (rc < 0) {
460 kfree_skb(skb);
461 goto error;
462 }
463
464 fl4 = &inet->cork.fl.u.ip4;
465 if (connected)
466 rt = (struct rtable *) __sk_dst_check(sk, 0);
467
468 rcu_read_lock();
469 if (rt == NULL) {
470 const struct ip_options_rcu *inet_opt;
471
472 inet_opt = rcu_dereference(inet->inet_opt);
473
474 /* Use correct destination address if we have options. */
475 if (inet_opt && inet_opt->opt.srr)
476 daddr = inet_opt->opt.faddr;
477
478 /* If this fails, retransmit mechanism of transport layer will
479 * keep trying until route appears or the connection times
480 * itself out.
481 */
482 rt = ip_route_output_ports(sock_net(sk), fl4, sk,
483 daddr, inet->inet_saddr,
484 inet->inet_dport, inet->inet_sport,
485 sk->sk_protocol, RT_CONN_FLAGS(sk),
486 sk->sk_bound_dev_if);
487 if (IS_ERR(rt))
488 goto no_route;
489 if (connected) {
490 sk_setup_caps(sk, &rt->dst);
491 } else {
492 skb_dst_set(skb, &rt->dst);
493 goto xmit;
494 }
495 }
496
497 /* We dont need to clone dst here, it is guaranteed to not disappear.
498 * __dev_xmit_skb() might force a refcount if needed.
499 */
500 skb_dst_set_noref(skb, &rt->dst);
501
502 xmit:
503 /* Queue the packet to IP for output */
504 rc = ip_queue_xmit(sk, skb, &inet->cork.fl);
505 rcu_read_unlock();
506
507 error:
508 if (rc >= 0)
509 rc = len;
510
511 out:
512 release_sock(sk);
513 return rc;
514
515 no_route:
516 rcu_read_unlock();
517 IP_INC_STATS(sock_net(sk), IPSTATS_MIB_OUTNOROUTES);
518 kfree_skb(skb);
519 rc = -EHOSTUNREACH;
520 goto out;
521 }
522
l2tp_ip_recvmsg(struct sock * sk,struct msghdr * msg,size_t len,int noblock,int flags,int * addr_len)523 static int l2tp_ip_recvmsg(struct sock *sk, struct msghdr *msg,
524 size_t len, int noblock, int flags, int *addr_len)
525 {
526 struct inet_sock *inet = inet_sk(sk);
527 size_t copied = 0;
528 int err = -EOPNOTSUPP;
529 DECLARE_SOCKADDR(struct sockaddr_in *, sin, msg->msg_name);
530 struct sk_buff *skb;
531
532 if (flags & MSG_OOB)
533 goto out;
534
535 skb = skb_recv_datagram(sk, flags, noblock, &err);
536 if (!skb)
537 goto out;
538
539 copied = skb->len;
540 if (len < copied) {
541 msg->msg_flags |= MSG_TRUNC;
542 copied = len;
543 }
544
545 err = skb_copy_datagram_msg(skb, 0, msg, copied);
546 if (err)
547 goto done;
548
549 sock_recv_timestamp(msg, sk, skb);
550
551 /* Copy the address. */
552 if (sin) {
553 sin->sin_family = AF_INET;
554 sin->sin_addr.s_addr = ip_hdr(skb)->saddr;
555 sin->sin_port = 0;
556 memset(&sin->sin_zero, 0, sizeof(sin->sin_zero));
557 *addr_len = sizeof(*sin);
558 }
559 if (inet->cmsg_flags)
560 ip_cmsg_recv(msg, skb);
561 if (flags & MSG_TRUNC)
562 copied = skb->len;
563 done:
564 skb_free_datagram(sk, skb);
565 out:
566 return err ? err : copied;
567 }
568
l2tp_ioctl(struct sock * sk,int cmd,unsigned long arg)569 int l2tp_ioctl(struct sock *sk, int cmd, unsigned long arg)
570 {
571 struct sk_buff *skb;
572 int amount;
573
574 switch (cmd) {
575 case SIOCOUTQ:
576 amount = sk_wmem_alloc_get(sk);
577 break;
578 case SIOCINQ:
579 spin_lock_bh(&sk->sk_receive_queue.lock);
580 skb = skb_peek(&sk->sk_receive_queue);
581 amount = skb ? skb->len : 0;
582 spin_unlock_bh(&sk->sk_receive_queue.lock);
583 break;
584
585 default:
586 return -ENOIOCTLCMD;
587 }
588
589 return put_user(amount, (int __user *)arg);
590 }
591 EXPORT_SYMBOL(l2tp_ioctl);
592
593 static struct proto l2tp_ip_prot = {
594 .name = "L2TP/IP",
595 .owner = THIS_MODULE,
596 .init = l2tp_ip_open,
597 .close = l2tp_ip_close,
598 .bind = l2tp_ip_bind,
599 .connect = l2tp_ip_connect,
600 .disconnect = l2tp_ip_disconnect,
601 .ioctl = l2tp_ioctl,
602 .destroy = l2tp_ip_destroy_sock,
603 .setsockopt = ip_setsockopt,
604 .getsockopt = ip_getsockopt,
605 .sendmsg = l2tp_ip_sendmsg,
606 .recvmsg = l2tp_ip_recvmsg,
607 .backlog_rcv = l2tp_ip_backlog_recv,
608 .hash = inet_hash,
609 .unhash = inet_unhash,
610 .obj_size = sizeof(struct l2tp_ip_sock),
611 #ifdef CONFIG_COMPAT
612 .compat_setsockopt = compat_ip_setsockopt,
613 .compat_getsockopt = compat_ip_getsockopt,
614 #endif
615 };
616
617 static const struct proto_ops l2tp_ip_ops = {
618 .family = PF_INET,
619 .owner = THIS_MODULE,
620 .release = inet_release,
621 .bind = inet_bind,
622 .connect = inet_dgram_connect,
623 .socketpair = sock_no_socketpair,
624 .accept = sock_no_accept,
625 .getname = l2tp_ip_getname,
626 .poll = datagram_poll,
627 .ioctl = inet_ioctl,
628 .listen = sock_no_listen,
629 .shutdown = inet_shutdown,
630 .setsockopt = sock_common_setsockopt,
631 .getsockopt = sock_common_getsockopt,
632 .sendmsg = inet_sendmsg,
633 .recvmsg = sock_common_recvmsg,
634 .mmap = sock_no_mmap,
635 .sendpage = sock_no_sendpage,
636 #ifdef CONFIG_COMPAT
637 .compat_setsockopt = compat_sock_common_setsockopt,
638 .compat_getsockopt = compat_sock_common_getsockopt,
639 #endif
640 };
641
642 static struct inet_protosw l2tp_ip_protosw = {
643 .type = SOCK_DGRAM,
644 .protocol = IPPROTO_L2TP,
645 .prot = &l2tp_ip_prot,
646 .ops = &l2tp_ip_ops,
647 };
648
649 static struct net_protocol l2tp_ip_protocol __read_mostly = {
650 .handler = l2tp_ip_recv,
651 .netns_ok = 1,
652 };
653
l2tp_ip_init(void)654 static int __init l2tp_ip_init(void)
655 {
656 int err;
657
658 pr_info("L2TP IP encapsulation support (L2TPv3)\n");
659
660 err = proto_register(&l2tp_ip_prot, 1);
661 if (err != 0)
662 goto out;
663
664 err = inet_add_protocol(&l2tp_ip_protocol, IPPROTO_L2TP);
665 if (err)
666 goto out1;
667
668 inet_register_protosw(&l2tp_ip_protosw);
669 return 0;
670
671 out1:
672 proto_unregister(&l2tp_ip_prot);
673 out:
674 return err;
675 }
676
l2tp_ip_exit(void)677 static void __exit l2tp_ip_exit(void)
678 {
679 inet_unregister_protosw(&l2tp_ip_protosw);
680 inet_del_protocol(&l2tp_ip_protocol, IPPROTO_L2TP);
681 proto_unregister(&l2tp_ip_prot);
682 }
683
684 module_init(l2tp_ip_init);
685 module_exit(l2tp_ip_exit);
686
687 MODULE_LICENSE("GPL");
688 MODULE_AUTHOR("James Chapman <jchapman@katalix.com>");
689 MODULE_DESCRIPTION("L2TP over IP");
690 MODULE_VERSION("1.0");
691
692 /* Use the value of SOCK_DGRAM (2) directory, because __stringify doesn't like
693 * enums
694 */
695 MODULE_ALIAS_NET_PF_PROTO_TYPE(PF_INET, 2, IPPROTO_L2TP);
696 MODULE_ALIAS_NET_PF_PROTO(PF_INET, IPPROTO_L2TP);
697