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 #include <linux/icmp.h>
13 #include <linux/module.h>
14 #include <linux/skbuff.h>
15 #include <linux/random.h>
16 #include <linux/socket.h>
17 #include <linux/l2tp.h>
18 #include <linux/in.h>
19 #include <net/sock.h>
20 #include <net/ip.h>
21 #include <net/icmp.h>
22 #include <net/udp.h>
23 #include <net/inet_common.h>
24 #include <net/inet_hashtables.h>
25 #include <net/tcp_states.h>
26 #include <net/protocol.h>
27 #include <net/xfrm.h>
28
29 #include "l2tp_core.h"
30
31 struct l2tp_ip_sock {
32 /* inet_sock has to be the first member of l2tp_ip_sock */
33 struct inet_sock inet;
34
35 __u32 conn_id;
36 __u32 peer_conn_id;
37
38 __u64 tx_packets;
39 __u64 tx_bytes;
40 __u64 tx_errors;
41 __u64 rx_packets;
42 __u64 rx_bytes;
43 __u64 rx_errors;
44 };
45
46 static DEFINE_RWLOCK(l2tp_ip_lock);
47 static struct hlist_head l2tp_ip_table;
48 static struct hlist_head l2tp_ip_bind_table;
49
l2tp_ip_sk(const struct sock * sk)50 static inline struct l2tp_ip_sock *l2tp_ip_sk(const struct sock *sk)
51 {
52 return (struct l2tp_ip_sock *)sk;
53 }
54
__l2tp_ip_bind_lookup(struct net * net,__be32 laddr,int dif,u32 tunnel_id)55 static struct sock *__l2tp_ip_bind_lookup(struct net *net, __be32 laddr, int dif, u32 tunnel_id)
56 {
57 struct hlist_node *node;
58 struct sock *sk;
59
60 sk_for_each_bound(sk, node, &l2tp_ip_bind_table) {
61 struct inet_sock *inet = inet_sk(sk);
62 struct l2tp_ip_sock *l2tp = l2tp_ip_sk(sk);
63
64 if (l2tp == NULL)
65 continue;
66
67 if ((l2tp->conn_id == tunnel_id) &&
68 net_eq(sock_net(sk), net) &&
69 !(inet->inet_rcv_saddr && inet->inet_rcv_saddr != laddr) &&
70 !(sk->sk_bound_dev_if && sk->sk_bound_dev_if != dif))
71 goto found;
72 }
73
74 sk = NULL;
75 found:
76 return sk;
77 }
78
l2tp_ip_bind_lookup(struct net * net,__be32 laddr,int dif,u32 tunnel_id)79 static inline struct sock *l2tp_ip_bind_lookup(struct net *net, __be32 laddr, int dif, u32 tunnel_id)
80 {
81 struct sock *sk = __l2tp_ip_bind_lookup(net, laddr, dif, tunnel_id);
82 if (sk)
83 sock_hold(sk);
84
85 return sk;
86 }
87
88 /* When processing receive frames, there are two cases to
89 * consider. Data frames consist of a non-zero session-id and an
90 * optional cookie. Control frames consist of a regular L2TP header
91 * preceded by 32-bits of zeros.
92 *
93 * L2TPv3 Session Header Over IP
94 *
95 * 0 1 2 3
96 * 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
97 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
98 * | Session ID |
99 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
100 * | Cookie (optional, maximum 64 bits)...
101 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
102 * |
103 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
104 *
105 * L2TPv3 Control Message Header Over IP
106 *
107 * 0 1 2 3
108 * 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
109 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
110 * | (32 bits of zeros) |
111 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
112 * |T|L|x|x|S|x|x|x|x|x|x|x| Ver | Length |
113 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
114 * | Control Connection ID |
115 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
116 * | Ns | Nr |
117 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
118 *
119 * All control frames are passed to userspace.
120 */
l2tp_ip_recv(struct sk_buff * skb)121 static int l2tp_ip_recv(struct sk_buff *skb)
122 {
123 struct sock *sk;
124 u32 session_id;
125 u32 tunnel_id;
126 unsigned char *ptr, *optr;
127 struct l2tp_session *session;
128 struct l2tp_tunnel *tunnel = NULL;
129 int length;
130 int offset;
131
132 /* Point to L2TP header */
133 optr = ptr = skb->data;
134
135 if (!pskb_may_pull(skb, 4))
136 goto discard;
137
138 session_id = ntohl(*((__be32 *) ptr));
139 ptr += 4;
140
141 /* RFC3931: L2TP/IP packets have the first 4 bytes containing
142 * the session_id. If it is 0, the packet is a L2TP control
143 * frame and the session_id value can be discarded.
144 */
145 if (session_id == 0) {
146 __skb_pull(skb, 4);
147 goto pass_up;
148 }
149
150 /* Ok, this is a data packet. Lookup the session. */
151 session = l2tp_session_find(&init_net, NULL, session_id);
152 if (session == NULL)
153 goto discard;
154
155 tunnel = session->tunnel;
156 if (tunnel == NULL)
157 goto discard;
158
159 /* Trace packet contents, if enabled */
160 if (tunnel->debug & L2TP_MSG_DATA) {
161 length = min(32u, skb->len);
162 if (!pskb_may_pull(skb, length))
163 goto discard;
164
165 printk(KERN_DEBUG "%s: ip recv: ", tunnel->name);
166
167 offset = 0;
168 do {
169 printk(" %02X", ptr[offset]);
170 } while (++offset < length);
171
172 printk("\n");
173 }
174
175 l2tp_recv_common(session, skb, ptr, optr, 0, skb->len, tunnel->recv_payload_hook);
176
177 return 0;
178
179 pass_up:
180 /* Get the tunnel_id from the L2TP header */
181 if (!pskb_may_pull(skb, 12))
182 goto discard;
183
184 if ((skb->data[0] & 0xc0) != 0xc0)
185 goto discard;
186
187 tunnel_id = ntohl(*(__be32 *) &skb->data[4]);
188 tunnel = l2tp_tunnel_find(&init_net, tunnel_id);
189 if (tunnel != NULL)
190 sk = tunnel->sock;
191 else {
192 struct iphdr *iph = (struct iphdr *) skb_network_header(skb);
193
194 read_lock_bh(&l2tp_ip_lock);
195 sk = __l2tp_ip_bind_lookup(&init_net, iph->daddr, 0, tunnel_id);
196 read_unlock_bh(&l2tp_ip_lock);
197 }
198
199 if (sk == NULL)
200 goto discard;
201
202 sock_hold(sk);
203
204 if (!xfrm4_policy_check(sk, XFRM_POLICY_IN, skb))
205 goto discard_put;
206
207 nf_reset(skb);
208
209 return sk_receive_skb(sk, skb, 1);
210
211 discard_put:
212 sock_put(sk);
213
214 discard:
215 kfree_skb(skb);
216 return 0;
217 }
218
l2tp_ip_open(struct sock * sk)219 static int l2tp_ip_open(struct sock *sk)
220 {
221 /* Prevent autobind. We don't have ports. */
222 inet_sk(sk)->inet_num = IPPROTO_L2TP;
223
224 write_lock_bh(&l2tp_ip_lock);
225 sk_add_node(sk, &l2tp_ip_table);
226 write_unlock_bh(&l2tp_ip_lock);
227
228 return 0;
229 }
230
l2tp_ip_close(struct sock * sk,long timeout)231 static void l2tp_ip_close(struct sock *sk, long timeout)
232 {
233 write_lock_bh(&l2tp_ip_lock);
234 hlist_del_init(&sk->sk_bind_node);
235 hlist_del_init(&sk->sk_node);
236 write_unlock_bh(&l2tp_ip_lock);
237 sk_common_release(sk);
238 }
239
l2tp_ip_destroy_sock(struct sock * sk)240 static void l2tp_ip_destroy_sock(struct sock *sk)
241 {
242 struct sk_buff *skb;
243
244 while ((skb = __skb_dequeue_tail(&sk->sk_write_queue)) != NULL)
245 kfree_skb(skb);
246
247 sk_refcnt_debug_dec(sk);
248 }
249
l2tp_ip_bind(struct sock * sk,struct sockaddr * uaddr,int addr_len)250 static int l2tp_ip_bind(struct sock *sk, struct sockaddr *uaddr, int addr_len)
251 {
252 struct inet_sock *inet = inet_sk(sk);
253 struct sockaddr_l2tpip *addr = (struct sockaddr_l2tpip *) uaddr;
254 int ret = -EINVAL;
255 int chk_addr_ret;
256
257 ret = -EADDRINUSE;
258 read_lock_bh(&l2tp_ip_lock);
259 if (__l2tp_ip_bind_lookup(&init_net, addr->l2tp_addr.s_addr, sk->sk_bound_dev_if, addr->l2tp_conn_id))
260 goto out_in_use;
261
262 read_unlock_bh(&l2tp_ip_lock);
263
264 lock_sock(sk);
265 if (sk->sk_state != TCP_CLOSE || addr_len < sizeof(struct sockaddr_l2tpip))
266 goto out;
267
268 chk_addr_ret = inet_addr_type(&init_net, addr->l2tp_addr.s_addr);
269 ret = -EADDRNOTAVAIL;
270 if (addr->l2tp_addr.s_addr && chk_addr_ret != RTN_LOCAL &&
271 chk_addr_ret != RTN_MULTICAST && chk_addr_ret != RTN_BROADCAST)
272 goto out;
273
274 inet->inet_rcv_saddr = inet->inet_saddr = addr->l2tp_addr.s_addr;
275 if (chk_addr_ret == RTN_MULTICAST || chk_addr_ret == RTN_BROADCAST)
276 inet->inet_saddr = 0; /* Use device */
277 sk_dst_reset(sk);
278
279 l2tp_ip_sk(sk)->conn_id = addr->l2tp_conn_id;
280
281 write_lock_bh(&l2tp_ip_lock);
282 sk_add_bind_node(sk, &l2tp_ip_bind_table);
283 sk_del_node_init(sk);
284 write_unlock_bh(&l2tp_ip_lock);
285 ret = 0;
286 out:
287 release_sock(sk);
288
289 return ret;
290
291 out_in_use:
292 read_unlock_bh(&l2tp_ip_lock);
293
294 return ret;
295 }
296
l2tp_ip_connect(struct sock * sk,struct sockaddr * uaddr,int addr_len)297 static int l2tp_ip_connect(struct sock *sk, struct sockaddr *uaddr, int addr_len)
298 {
299 struct sockaddr_l2tpip *lsa = (struct sockaddr_l2tpip *) uaddr;
300 struct inet_sock *inet = inet_sk(sk);
301 struct flowi4 *fl4;
302 struct rtable *rt;
303 __be32 saddr;
304 int oif, rc;
305
306 rc = -EINVAL;
307 if (addr_len < sizeof(*lsa))
308 goto out;
309
310 rc = -EAFNOSUPPORT;
311 if (lsa->l2tp_family != AF_INET)
312 goto out;
313
314 lock_sock(sk);
315
316 sk_dst_reset(sk);
317
318 oif = sk->sk_bound_dev_if;
319 saddr = inet->inet_saddr;
320
321 rc = -EINVAL;
322 if (ipv4_is_multicast(lsa->l2tp_addr.s_addr))
323 goto out;
324
325 fl4 = &inet->cork.fl.u.ip4;
326 rt = ip_route_connect(fl4, lsa->l2tp_addr.s_addr, saddr,
327 RT_CONN_FLAGS(sk), oif,
328 IPPROTO_L2TP,
329 0, 0, sk, true);
330 if (IS_ERR(rt)) {
331 rc = PTR_ERR(rt);
332 if (rc == -ENETUNREACH)
333 IP_INC_STATS_BH(&init_net, IPSTATS_MIB_OUTNOROUTES);
334 goto out;
335 }
336
337 rc = -ENETUNREACH;
338 if (rt->rt_flags & (RTCF_MULTICAST | RTCF_BROADCAST)) {
339 ip_rt_put(rt);
340 goto out;
341 }
342
343 l2tp_ip_sk(sk)->peer_conn_id = lsa->l2tp_conn_id;
344
345 if (!inet->inet_saddr)
346 inet->inet_saddr = fl4->saddr;
347 if (!inet->inet_rcv_saddr)
348 inet->inet_rcv_saddr = fl4->saddr;
349 inet->inet_daddr = fl4->daddr;
350 sk->sk_state = TCP_ESTABLISHED;
351 inet->inet_id = jiffies;
352
353 sk_dst_set(sk, &rt->dst);
354
355 write_lock_bh(&l2tp_ip_lock);
356 hlist_del_init(&sk->sk_bind_node);
357 sk_add_bind_node(sk, &l2tp_ip_bind_table);
358 write_unlock_bh(&l2tp_ip_lock);
359
360 rc = 0;
361 out:
362 release_sock(sk);
363 return rc;
364 }
365
l2tp_ip_getname(struct socket * sock,struct sockaddr * uaddr,int * uaddr_len,int peer)366 static int l2tp_ip_getname(struct socket *sock, struct sockaddr *uaddr,
367 int *uaddr_len, int peer)
368 {
369 struct sock *sk = sock->sk;
370 struct inet_sock *inet = inet_sk(sk);
371 struct l2tp_ip_sock *lsk = l2tp_ip_sk(sk);
372 struct sockaddr_l2tpip *lsa = (struct sockaddr_l2tpip *)uaddr;
373
374 memset(lsa, 0, sizeof(*lsa));
375 lsa->l2tp_family = AF_INET;
376 if (peer) {
377 if (!inet->inet_dport)
378 return -ENOTCONN;
379 lsa->l2tp_conn_id = lsk->peer_conn_id;
380 lsa->l2tp_addr.s_addr = inet->inet_daddr;
381 } else {
382 __be32 addr = inet->inet_rcv_saddr;
383 if (!addr)
384 addr = inet->inet_saddr;
385 lsa->l2tp_conn_id = lsk->conn_id;
386 lsa->l2tp_addr.s_addr = addr;
387 }
388 *uaddr_len = sizeof(*lsa);
389 return 0;
390 }
391
l2tp_ip_backlog_recv(struct sock * sk,struct sk_buff * skb)392 static int l2tp_ip_backlog_recv(struct sock *sk, struct sk_buff *skb)
393 {
394 int rc;
395
396 /* Charge it to the socket, dropping if the queue is full. */
397 rc = sock_queue_rcv_skb(sk, skb);
398 if (rc < 0)
399 goto drop;
400
401 return 0;
402
403 drop:
404 IP_INC_STATS(&init_net, IPSTATS_MIB_INDISCARDS);
405 kfree_skb(skb);
406 return -1;
407 }
408
409 /* Userspace will call sendmsg() on the tunnel socket to send L2TP
410 * control frames.
411 */
l2tp_ip_sendmsg(struct kiocb * iocb,struct sock * sk,struct msghdr * msg,size_t len)412 static int l2tp_ip_sendmsg(struct kiocb *iocb, struct sock *sk, struct msghdr *msg, size_t len)
413 {
414 struct sk_buff *skb;
415 int rc;
416 struct l2tp_ip_sock *lsa = l2tp_ip_sk(sk);
417 struct inet_sock *inet = inet_sk(sk);
418 struct rtable *rt = NULL;
419 struct flowi4 *fl4;
420 int connected = 0;
421 __be32 daddr;
422
423 lock_sock(sk);
424
425 rc = -ENOTCONN;
426 if (sock_flag(sk, SOCK_DEAD))
427 goto out;
428
429 /* Get and verify the address. */
430 if (msg->msg_name) {
431 struct sockaddr_l2tpip *lip = (struct sockaddr_l2tpip *) msg->msg_name;
432 rc = -EINVAL;
433 if (msg->msg_namelen < sizeof(*lip))
434 goto out;
435
436 if (lip->l2tp_family != AF_INET) {
437 rc = -EAFNOSUPPORT;
438 if (lip->l2tp_family != AF_UNSPEC)
439 goto out;
440 }
441
442 daddr = lip->l2tp_addr.s_addr;
443 } else {
444 if (sk->sk_state != TCP_ESTABLISHED)
445 return -EDESTADDRREQ;
446
447 daddr = inet->inet_daddr;
448 connected = 1;
449 }
450
451 /* Allocate a socket buffer */
452 rc = -ENOMEM;
453 skb = sock_wmalloc(sk, 2 + NET_SKB_PAD + sizeof(struct iphdr) +
454 4 + len, 0, GFP_KERNEL);
455 if (!skb)
456 goto error;
457
458 /* Reserve space for headers, putting IP header on 4-byte boundary. */
459 skb_reserve(skb, 2 + NET_SKB_PAD);
460 skb_reset_network_header(skb);
461 skb_reserve(skb, sizeof(struct iphdr));
462 skb_reset_transport_header(skb);
463
464 /* Insert 0 session_id */
465 *((__be32 *) skb_put(skb, 4)) = 0;
466
467 /* Copy user data into skb */
468 rc = memcpy_fromiovec(skb_put(skb, len), msg->msg_iov, len);
469 if (rc < 0) {
470 kfree_skb(skb);
471 goto error;
472 }
473
474 fl4 = &inet->cork.fl.u.ip4;
475 if (connected)
476 rt = (struct rtable *) __sk_dst_check(sk, 0);
477
478 rcu_read_lock();
479 if (rt == NULL) {
480 const struct ip_options_rcu *inet_opt;
481
482 inet_opt = rcu_dereference(inet->inet_opt);
483
484 /* Use correct destination address if we have options. */
485 if (inet_opt && inet_opt->opt.srr)
486 daddr = inet_opt->opt.faddr;
487
488 /* If this fails, retransmit mechanism of transport layer will
489 * keep trying until route appears or the connection times
490 * itself out.
491 */
492 rt = ip_route_output_ports(sock_net(sk), fl4, sk,
493 daddr, inet->inet_saddr,
494 inet->inet_dport, inet->inet_sport,
495 sk->sk_protocol, RT_CONN_FLAGS(sk),
496 sk->sk_bound_dev_if);
497 if (IS_ERR(rt))
498 goto no_route;
499 if (connected)
500 sk_setup_caps(sk, &rt->dst);
501 else
502 dst_release(&rt->dst); /* safe since we hold rcu_read_lock */
503 }
504
505 /* We dont need to clone dst here, it is guaranteed to not disappear.
506 * __dev_xmit_skb() might force a refcount if needed.
507 */
508 skb_dst_set_noref(skb, &rt->dst);
509
510 /* Queue the packet to IP for output */
511 rc = ip_queue_xmit(skb, &inet->cork.fl);
512 rcu_read_unlock();
513
514 error:
515 /* Update stats */
516 if (rc >= 0) {
517 lsa->tx_packets++;
518 lsa->tx_bytes += len;
519 rc = len;
520 } else {
521 lsa->tx_errors++;
522 }
523
524 out:
525 release_sock(sk);
526 return rc;
527
528 no_route:
529 rcu_read_unlock();
530 IP_INC_STATS(sock_net(sk), IPSTATS_MIB_OUTNOROUTES);
531 kfree_skb(skb);
532 rc = -EHOSTUNREACH;
533 goto out;
534 }
535
l2tp_ip_recvmsg(struct kiocb * iocb,struct sock * sk,struct msghdr * msg,size_t len,int noblock,int flags,int * addr_len)536 static int l2tp_ip_recvmsg(struct kiocb *iocb, struct sock *sk, struct msghdr *msg,
537 size_t len, int noblock, int flags, int *addr_len)
538 {
539 struct inet_sock *inet = inet_sk(sk);
540 struct l2tp_ip_sock *lsk = l2tp_ip_sk(sk);
541 size_t copied = 0;
542 int err = -EOPNOTSUPP;
543 struct sockaddr_in *sin = (struct sockaddr_in *)msg->msg_name;
544 struct sk_buff *skb;
545
546 if (flags & MSG_OOB)
547 goto out;
548
549 if (addr_len)
550 *addr_len = sizeof(*sin);
551
552 skb = skb_recv_datagram(sk, flags, noblock, &err);
553 if (!skb)
554 goto out;
555
556 copied = skb->len;
557 if (len < copied) {
558 msg->msg_flags |= MSG_TRUNC;
559 copied = len;
560 }
561
562 err = skb_copy_datagram_iovec(skb, 0, msg->msg_iov, copied);
563 if (err)
564 goto done;
565
566 sock_recv_timestamp(msg, sk, skb);
567
568 /* Copy the address. */
569 if (sin) {
570 sin->sin_family = AF_INET;
571 sin->sin_addr.s_addr = ip_hdr(skb)->saddr;
572 sin->sin_port = 0;
573 memset(&sin->sin_zero, 0, sizeof(sin->sin_zero));
574 }
575 if (inet->cmsg_flags)
576 ip_cmsg_recv(msg, skb);
577 if (flags & MSG_TRUNC)
578 copied = skb->len;
579 done:
580 skb_free_datagram(sk, skb);
581 out:
582 if (err) {
583 lsk->rx_errors++;
584 return err;
585 }
586
587 lsk->rx_packets++;
588 lsk->rx_bytes += copied;
589
590 return copied;
591 }
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 = udp_disconnect,
601 .ioctl = udp_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 .no_check = 0,
648 };
649
650 static struct net_protocol l2tp_ip_protocol __read_mostly = {
651 .handler = l2tp_ip_recv,
652 };
653
l2tp_ip_init(void)654 static int __init l2tp_ip_init(void)
655 {
656 int err;
657
658 printk(KERN_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