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1/*
2 * L2TPv3 IP encapsulation support for IPv6
3 *
4 * Copyright (c) 2012 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 <linux/icmp.h>
15#include <linux/module.h>
16#include <linux/skbuff.h>
17#include <linux/random.h>
18#include <linux/socket.h>
19#include <linux/l2tp.h>
20#include <linux/in.h>
21#include <linux/in6.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/inet6_hashtables.h>
29#include <net/tcp_states.h>
30#include <net/protocol.h>
31#include <net/xfrm.h>
32
33#include <net/transp_v6.h>
34#include <net/addrconf.h>
35#include <net/ip6_route.h>
36
37#include "l2tp_core.h"
38
39struct l2tp_ip6_sock {
40 /* inet_sock has to be the first member of l2tp_ip6_sock */
41 struct inet_sock inet;
42
43 u32 conn_id;
44 u32 peer_conn_id;
45
46 /* ipv6_pinfo has to be the last member of l2tp_ip6_sock, see
47 inet6_sk_generic */
48 struct ipv6_pinfo inet6;
49};
50
51static DEFINE_RWLOCK(l2tp_ip6_lock);
52static struct hlist_head l2tp_ip6_table;
53static struct hlist_head l2tp_ip6_bind_table;
54
55static inline struct l2tp_ip6_sock *l2tp_ip6_sk(const struct sock *sk)
56{
57 return (struct l2tp_ip6_sock *)sk;
58}
59
60static struct sock *__l2tp_ip6_bind_lookup(struct net *net,
61 struct in6_addr *laddr,
62 int dif, u32 tunnel_id)
63{
64 struct sock *sk;
65
66 sk_for_each_bound(sk, &l2tp_ip6_bind_table) {
67 const struct in6_addr *addr = inet6_rcv_saddr(sk);
68 struct l2tp_ip6_sock *l2tp = l2tp_ip6_sk(sk);
69
70 if (l2tp == NULL)
71 continue;
72
73 if ((l2tp->conn_id == tunnel_id) &&
74 net_eq(sock_net(sk), net) &&
75 !(addr && ipv6_addr_equal(addr, laddr)) &&
76 !(sk->sk_bound_dev_if && sk->sk_bound_dev_if != dif))
77 goto found;
78 }
79
80 sk = NULL;
81found:
82 return sk;
83}
84
85static inline struct sock *l2tp_ip6_bind_lookup(struct net *net,
86 struct in6_addr *laddr,
87 int dif, u32 tunnel_id)
88{
89 struct sock *sk = __l2tp_ip6_bind_lookup(net, laddr, dif, tunnel_id);
90 if (sk)
91 sock_hold(sk);
92
93 return sk;
94}
95
96/* When processing receive frames, there are two cases to
97 * consider. Data frames consist of a non-zero session-id and an
98 * optional cookie. Control frames consist of a regular L2TP header
99 * preceded by 32-bits of zeros.
100 *
101 * L2TPv3 Session 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 * | Session ID |
107 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
108 * | Cookie (optional, maximum 64 bits)...
109 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
110 * |
111 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
112 *
113 * L2TPv3 Control Message Header Over IP
114 *
115 * 0 1 2 3
116 * 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
117 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
118 * | (32 bits of zeros) |
119 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
120 * |T|L|x|x|S|x|x|x|x|x|x|x| Ver | Length |
121 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
122 * | Control Connection ID |
123 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
124 * | Ns | Nr |
125 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
126 *
127 * All control frames are passed to userspace.
128 */
129static int l2tp_ip6_recv(struct sk_buff *skb)
130{
131 struct sock *sk;
132 u32 session_id;
133 u32 tunnel_id;
134 unsigned char *ptr, *optr;
135 struct l2tp_session *session;
136 struct l2tp_tunnel *tunnel = NULL;
137 int length;
138
139 if (!pskb_may_pull(skb, 4))
140 goto discard;
141
142 /* Point to L2TP header */
143 optr = ptr = skb->data;
144 session_id = ntohl(*((__be32 *) ptr));
145 ptr += 4;
146
147 /* RFC3931: L2TP/IP packets have the first 4 bytes containing
148 * the session_id. If it is 0, the packet is a L2TP control
149 * frame and the session_id value can be discarded.
150 */
151 if (session_id == 0) {
152 __skb_pull(skb, 4);
153 goto pass_up;
154 }
155
156 /* Ok, this is a data packet. Lookup the session. */
157 session = l2tp_session_find(&init_net, NULL, session_id);
158 if (session == NULL)
159 goto discard;
160
161 tunnel = session->tunnel;
162 if (tunnel == NULL)
163 goto discard;
164
165 /* Trace packet contents, if enabled */
166 if (tunnel->debug & L2TP_MSG_DATA) {
167 length = min(32u, skb->len);
168 if (!pskb_may_pull(skb, length))
169 goto discard;
170
171 /* Point to L2TP header */
172 optr = ptr = skb->data;
173 ptr += 4;
174 pr_debug("%s: ip recv\n", tunnel->name);
175 print_hex_dump_bytes("", DUMP_PREFIX_OFFSET, ptr, length);
176 }
177
178 l2tp_recv_common(session, skb, ptr, optr, 0, skb->len,
179 tunnel->recv_payload_hook);
180 return 0;
181
182pass_up:
183 /* Get the tunnel_id from the L2TP header */
184 if (!pskb_may_pull(skb, 12))
185 goto discard;
186
187 if ((skb->data[0] & 0xc0) != 0xc0)
188 goto discard;
189
190 tunnel_id = ntohl(*(__be32 *) &skb->data[4]);
191 tunnel = l2tp_tunnel_find(&init_net, tunnel_id);
192 if (tunnel != NULL)
193 sk = tunnel->sock;
194 else {
195 struct ipv6hdr *iph = ipv6_hdr(skb);
196
197 read_lock_bh(&l2tp_ip6_lock);
198 sk = __l2tp_ip6_bind_lookup(&init_net, &iph->daddr,
199 0, tunnel_id);
200 read_unlock_bh(&l2tp_ip6_lock);
201 }
202
203 if (sk == NULL)
204 goto discard;
205
206 sock_hold(sk);
207
208 if (!xfrm6_policy_check(sk, XFRM_POLICY_IN, skb))
209 goto discard_put;
210
211 nf_reset(skb);
212
213 return sk_receive_skb(sk, skb, 1);
214
215discard_put:
216 sock_put(sk);
217
218discard:
219 kfree_skb(skb);
220 return 0;
221}
222
223static int l2tp_ip6_open(struct sock *sk)
224{
225 /* Prevent autobind. We don't have ports. */
226 inet_sk(sk)->inet_num = IPPROTO_L2TP;
227
228 write_lock_bh(&l2tp_ip6_lock);
229 sk_add_node(sk, &l2tp_ip6_table);
230 write_unlock_bh(&l2tp_ip6_lock);
231
232 return 0;
233}
234
235static void l2tp_ip6_close(struct sock *sk, long timeout)
236{
237 write_lock_bh(&l2tp_ip6_lock);
238 hlist_del_init(&sk->sk_bind_node);
239 sk_del_node_init(sk);
240 write_unlock_bh(&l2tp_ip6_lock);
241
242 sk_common_release(sk);
243}
244
245static void l2tp_ip6_destroy_sock(struct sock *sk)
246{
247 struct l2tp_tunnel *tunnel = l2tp_sock_to_tunnel(sk);
248
249 lock_sock(sk);
250 ip6_flush_pending_frames(sk);
251 release_sock(sk);
252
253 if (tunnel) {
254 l2tp_tunnel_closeall(tunnel);
255 sock_put(sk);
256 }
257
258 inet6_destroy_sock(sk);
259}
260
261static int l2tp_ip6_bind(struct sock *sk, struct sockaddr *uaddr, int addr_len)
262{
263 struct inet_sock *inet = inet_sk(sk);
264 struct ipv6_pinfo *np = inet6_sk(sk);
265 struct sockaddr_l2tpip6 *addr = (struct sockaddr_l2tpip6 *) uaddr;
266 __be32 v4addr = 0;
267 int addr_type;
268 int err;
269
270 if (!sock_flag(sk, SOCK_ZAPPED))
271 return -EINVAL;
272 if (addr->l2tp_family != AF_INET6)
273 return -EINVAL;
274 if (addr_len < sizeof(*addr))
275 return -EINVAL;
276
277 addr_type = ipv6_addr_type(&addr->l2tp_addr);
278
279 /* l2tp_ip6 sockets are IPv6 only */
280 if (addr_type == IPV6_ADDR_MAPPED)
281 return -EADDRNOTAVAIL;
282
283 /* L2TP is point-point, not multicast */
284 if (addr_type & IPV6_ADDR_MULTICAST)
285 return -EADDRNOTAVAIL;
286
287 err = -EADDRINUSE;
288 read_lock_bh(&l2tp_ip6_lock);
289 if (__l2tp_ip6_bind_lookup(&init_net, &addr->l2tp_addr,
290 sk->sk_bound_dev_if, addr->l2tp_conn_id))
291 goto out_in_use;
292 read_unlock_bh(&l2tp_ip6_lock);
293
294 lock_sock(sk);
295
296 err = -EINVAL;
297 if (sk->sk_state != TCP_CLOSE)
298 goto out_unlock;
299
300 /* Check if the address belongs to the host. */
301 rcu_read_lock();
302 if (addr_type != IPV6_ADDR_ANY) {
303 struct net_device *dev = NULL;
304
305 if (addr_type & IPV6_ADDR_LINKLOCAL) {
306 if (addr_len >= sizeof(struct sockaddr_in6) &&
307 addr->l2tp_scope_id) {
308 /* Override any existing binding, if another
309 * one is supplied by user.
310 */
311 sk->sk_bound_dev_if = addr->l2tp_scope_id;
312 }
313
314 /* Binding to link-local address requires an
315 interface */
316 if (!sk->sk_bound_dev_if)
317 goto out_unlock_rcu;
318
319 err = -ENODEV;
320 dev = dev_get_by_index_rcu(sock_net(sk),
321 sk->sk_bound_dev_if);
322 if (!dev)
323 goto out_unlock_rcu;
324 }
325
326 /* ipv4 addr of the socket is invalid. Only the
327 * unspecified and mapped address have a v4 equivalent.
328 */
329 v4addr = LOOPBACK4_IPV6;
330 err = -EADDRNOTAVAIL;
331 if (!ipv6_chk_addr(sock_net(sk), &addr->l2tp_addr, dev, 0))
332 goto out_unlock_rcu;
333 }
334 rcu_read_unlock();
335
336 inet->inet_rcv_saddr = inet->inet_saddr = v4addr;
337 sk->sk_v6_rcv_saddr = addr->l2tp_addr;
338 np->saddr = addr->l2tp_addr;
339
340 l2tp_ip6_sk(sk)->conn_id = addr->l2tp_conn_id;
341
342 write_lock_bh(&l2tp_ip6_lock);
343 sk_add_bind_node(sk, &l2tp_ip6_bind_table);
344 sk_del_node_init(sk);
345 write_unlock_bh(&l2tp_ip6_lock);
346
347 sock_reset_flag(sk, SOCK_ZAPPED);
348 release_sock(sk);
349 return 0;
350
351out_unlock_rcu:
352 rcu_read_unlock();
353out_unlock:
354 release_sock(sk);
355 return err;
356
357out_in_use:
358 read_unlock_bh(&l2tp_ip6_lock);
359 return err;
360}
361
362static int l2tp_ip6_connect(struct sock *sk, struct sockaddr *uaddr,
363 int addr_len)
364{
365 struct sockaddr_l2tpip6 *lsa = (struct sockaddr_l2tpip6 *) uaddr;
366 struct sockaddr_in6 *usin = (struct sockaddr_in6 *) uaddr;
367 struct in6_addr *daddr;
368 int addr_type;
369 int rc;
370
371 if (sock_flag(sk, SOCK_ZAPPED)) /* Must bind first - autobinding does not work */
372 return -EINVAL;
373
374 if (addr_len < sizeof(*lsa))
375 return -EINVAL;
376
377 if (usin->sin6_family != AF_INET6)
378 return -EINVAL;
379
380 addr_type = ipv6_addr_type(&usin->sin6_addr);
381 if (addr_type & IPV6_ADDR_MULTICAST)
382 return -EINVAL;
383
384 if (addr_type & IPV6_ADDR_MAPPED) {
385 daddr = &usin->sin6_addr;
386 if (ipv4_is_multicast(daddr->s6_addr32[3]))
387 return -EINVAL;
388 }
389
390 rc = ip6_datagram_connect(sk, uaddr, addr_len);
391
392 lock_sock(sk);
393
394 l2tp_ip6_sk(sk)->peer_conn_id = lsa->l2tp_conn_id;
395
396 write_lock_bh(&l2tp_ip6_lock);
397 hlist_del_init(&sk->sk_bind_node);
398 sk_add_bind_node(sk, &l2tp_ip6_bind_table);
399 write_unlock_bh(&l2tp_ip6_lock);
400
401 release_sock(sk);
402
403 return rc;
404}
405
406static int l2tp_ip6_disconnect(struct sock *sk, int flags)
407{
408 if (sock_flag(sk, SOCK_ZAPPED))
409 return 0;
410
411 return udp_disconnect(sk, flags);
412}
413
414static int l2tp_ip6_getname(struct socket *sock, struct sockaddr *uaddr,
415 int *uaddr_len, int peer)
416{
417 struct sockaddr_l2tpip6 *lsa = (struct sockaddr_l2tpip6 *)uaddr;
418 struct sock *sk = sock->sk;
419 struct ipv6_pinfo *np = inet6_sk(sk);
420 struct l2tp_ip6_sock *lsk = l2tp_ip6_sk(sk);
421
422 lsa->l2tp_family = AF_INET6;
423 lsa->l2tp_flowinfo = 0;
424 lsa->l2tp_scope_id = 0;
425 lsa->l2tp_unused = 0;
426 if (peer) {
427 if (!lsk->peer_conn_id)
428 return -ENOTCONN;
429 lsa->l2tp_conn_id = lsk->peer_conn_id;
430 lsa->l2tp_addr = sk->sk_v6_daddr;
431 if (np->sndflow)
432 lsa->l2tp_flowinfo = np->flow_label;
433 } else {
434 if (ipv6_addr_any(&sk->sk_v6_rcv_saddr))
435 lsa->l2tp_addr = np->saddr;
436 else
437 lsa->l2tp_addr = sk->sk_v6_rcv_saddr;
438
439 lsa->l2tp_conn_id = lsk->conn_id;
440 }
441 if (ipv6_addr_type(&lsa->l2tp_addr) & IPV6_ADDR_LINKLOCAL)
442 lsa->l2tp_scope_id = sk->sk_bound_dev_if;
443 *uaddr_len = sizeof(*lsa);
444 return 0;
445}
446
447static int l2tp_ip6_backlog_recv(struct sock *sk, struct sk_buff *skb)
448{
449 int rc;
450
451 /* Charge it to the socket, dropping if the queue is full. */
452 rc = sock_queue_rcv_skb(sk, skb);
453 if (rc < 0)
454 goto drop;
455
456 return 0;
457
458drop:
459 IP_INC_STATS(&init_net, IPSTATS_MIB_INDISCARDS);
460 kfree_skb(skb);
461 return -1;
462}
463
464static int l2tp_ip6_push_pending_frames(struct sock *sk)
465{
466 struct sk_buff *skb;
467 __be32 *transhdr = NULL;
468 int err = 0;
469
470 skb = skb_peek(&sk->sk_write_queue);
471 if (skb == NULL)
472 goto out;
473
474 transhdr = (__be32 *)skb_transport_header(skb);
475 *transhdr = 0;
476
477 err = ip6_push_pending_frames(sk);
478
479out:
480 return err;
481}
482
483/* Userspace will call sendmsg() on the tunnel socket to send L2TP
484 * control frames.
485 */
486static int l2tp_ip6_sendmsg(struct sock *sk, struct msghdr *msg, size_t len)
487{
488 struct ipv6_txoptions opt_space;
489 DECLARE_SOCKADDR(struct sockaddr_l2tpip6 *, lsa, msg->msg_name);
490 struct in6_addr *daddr, *final_p, final;
491 struct ipv6_pinfo *np = inet6_sk(sk);
492 struct ipv6_txoptions *opt_to_free = NULL;
493 struct ipv6_txoptions *opt = NULL;
494 struct ip6_flowlabel *flowlabel = NULL;
495 struct dst_entry *dst = NULL;
496 struct flowi6 fl6;
497 int addr_len = msg->msg_namelen;
498 int hlimit = -1;
499 int tclass = -1;
500 int dontfrag = -1;
501 int transhdrlen = 4; /* zero session-id */
502 int ulen = len + transhdrlen;
503 int err;
504
505 /* Rough check on arithmetic overflow,
506 better check is made in ip6_append_data().
507 */
508 if (len > INT_MAX)
509 return -EMSGSIZE;
510
511 /* Mirror BSD error message compatibility */
512 if (msg->msg_flags & MSG_OOB)
513 return -EOPNOTSUPP;
514
515 /*
516 * Get and verify the address.
517 */
518 memset(&fl6, 0, sizeof(fl6));
519
520 fl6.flowi6_mark = sk->sk_mark;
521
522 if (lsa) {
523 if (addr_len < SIN6_LEN_RFC2133)
524 return -EINVAL;
525
526 if (lsa->l2tp_family && lsa->l2tp_family != AF_INET6)
527 return -EAFNOSUPPORT;
528
529 daddr = &lsa->l2tp_addr;
530 if (np->sndflow) {
531 fl6.flowlabel = lsa->l2tp_flowinfo & IPV6_FLOWINFO_MASK;
532 if (fl6.flowlabel&IPV6_FLOWLABEL_MASK) {
533 flowlabel = fl6_sock_lookup(sk, fl6.flowlabel);
534 if (flowlabel == NULL)
535 return -EINVAL;
536 }
537 }
538
539 /*
540 * Otherwise it will be difficult to maintain
541 * sk->sk_dst_cache.
542 */
543 if (sk->sk_state == TCP_ESTABLISHED &&
544 ipv6_addr_equal(daddr, &sk->sk_v6_daddr))
545 daddr = &sk->sk_v6_daddr;
546
547 if (addr_len >= sizeof(struct sockaddr_in6) &&
548 lsa->l2tp_scope_id &&
549 ipv6_addr_type(daddr) & IPV6_ADDR_LINKLOCAL)
550 fl6.flowi6_oif = lsa->l2tp_scope_id;
551 } else {
552 if (sk->sk_state != TCP_ESTABLISHED)
553 return -EDESTADDRREQ;
554
555 daddr = &sk->sk_v6_daddr;
556 fl6.flowlabel = np->flow_label;
557 }
558
559 if (fl6.flowi6_oif == 0)
560 fl6.flowi6_oif = sk->sk_bound_dev_if;
561
562 if (msg->msg_controllen) {
563 opt = &opt_space;
564 memset(opt, 0, sizeof(struct ipv6_txoptions));
565 opt->tot_len = sizeof(struct ipv6_txoptions);
566
567 err = ip6_datagram_send_ctl(sock_net(sk), sk, msg, &fl6, opt,
568 &hlimit, &tclass, &dontfrag);
569 if (err < 0) {
570 fl6_sock_release(flowlabel);
571 return err;
572 }
573 if ((fl6.flowlabel & IPV6_FLOWLABEL_MASK) && !flowlabel) {
574 flowlabel = fl6_sock_lookup(sk, fl6.flowlabel);
575 if (flowlabel == NULL)
576 return -EINVAL;
577 }
578 if (!(opt->opt_nflen|opt->opt_flen))
579 opt = NULL;
580 }
581
582 if (!opt) {
583 opt = txopt_get(np);
584 opt_to_free = opt;
585 }
586 if (flowlabel)
587 opt = fl6_merge_options(&opt_space, flowlabel, opt);
588 opt = ipv6_fixup_options(&opt_space, opt);
589
590 fl6.flowi6_proto = sk->sk_protocol;
591 if (!ipv6_addr_any(daddr))
592 fl6.daddr = *daddr;
593 else
594 fl6.daddr.s6_addr[15] = 0x1; /* :: means loopback (BSD'ism) */
595 if (ipv6_addr_any(&fl6.saddr) && !ipv6_addr_any(&np->saddr))
596 fl6.saddr = np->saddr;
597
598 final_p = fl6_update_dst(&fl6, opt, &final);
599
600 if (!fl6.flowi6_oif && ipv6_addr_is_multicast(&fl6.daddr))
601 fl6.flowi6_oif = np->mcast_oif;
602 else if (!fl6.flowi6_oif)
603 fl6.flowi6_oif = np->ucast_oif;
604
605 security_sk_classify_flow(sk, flowi6_to_flowi(&fl6));
606
607 dst = ip6_dst_lookup_flow(sk, &fl6, final_p);
608 if (IS_ERR(dst)) {
609 err = PTR_ERR(dst);
610 goto out;
611 }
612
613 if (hlimit < 0)
614 hlimit = ip6_sk_dst_hoplimit(np, &fl6, dst);
615
616 if (tclass < 0)
617 tclass = np->tclass;
618
619 if (dontfrag < 0)
620 dontfrag = np->dontfrag;
621
622 if (msg->msg_flags & MSG_CONFIRM)
623 goto do_confirm;
624
625back_from_confirm:
626 lock_sock(sk);
627 err = ip6_append_data(sk, ip_generic_getfrag, msg,
628 ulen, transhdrlen, hlimit, tclass, opt,
629 &fl6, (struct rt6_info *)dst,
630 msg->msg_flags, dontfrag);
631 if (err)
632 ip6_flush_pending_frames(sk);
633 else if (!(msg->msg_flags & MSG_MORE))
634 err = l2tp_ip6_push_pending_frames(sk);
635 release_sock(sk);
636done:
637 dst_release(dst);
638out:
639 fl6_sock_release(flowlabel);
640 txopt_put(opt_to_free);
641
642 return err < 0 ? err : len;
643
644do_confirm:
645 dst_confirm(dst);
646 if (!(msg->msg_flags & MSG_PROBE) || len)
647 goto back_from_confirm;
648 err = 0;
649 goto done;
650}
651
652static int l2tp_ip6_recvmsg(struct sock *sk, struct msghdr *msg, size_t len,
653 int noblock, int flags, int *addr_len)
654{
655 struct ipv6_pinfo *np = inet6_sk(sk);
656 DECLARE_SOCKADDR(struct sockaddr_l2tpip6 *, lsa, msg->msg_name);
657 size_t copied = 0;
658 int err = -EOPNOTSUPP;
659 struct sk_buff *skb;
660
661 if (flags & MSG_OOB)
662 goto out;
663
664 if (addr_len)
665 *addr_len = sizeof(*lsa);
666
667 if (flags & MSG_ERRQUEUE)
668 return ipv6_recv_error(sk, msg, len, addr_len);
669
670 skb = skb_recv_datagram(sk, flags, noblock, &err);
671 if (!skb)
672 goto out;
673
674 copied = skb->len;
675 if (len < copied) {
676 msg->msg_flags |= MSG_TRUNC;
677 copied = len;
678 }
679
680 err = skb_copy_datagram_msg(skb, 0, msg, copied);
681 if (err)
682 goto done;
683
684 sock_recv_timestamp(msg, sk, skb);
685
686 /* Copy the address. */
687 if (lsa) {
688 lsa->l2tp_family = AF_INET6;
689 lsa->l2tp_unused = 0;
690 lsa->l2tp_addr = ipv6_hdr(skb)->saddr;
691 lsa->l2tp_flowinfo = 0;
692 lsa->l2tp_scope_id = 0;
693 lsa->l2tp_conn_id = 0;
694 if (ipv6_addr_type(&lsa->l2tp_addr) & IPV6_ADDR_LINKLOCAL)
695 lsa->l2tp_scope_id = inet6_iif(skb);
696 }
697
698 if (np->rxopt.all)
699 ip6_datagram_recv_ctl(sk, msg, skb);
700
701 if (flags & MSG_TRUNC)
702 copied = skb->len;
703done:
704 skb_free_datagram(sk, skb);
705out:
706 return err ? err : copied;
707}
708
709static struct proto l2tp_ip6_prot = {
710 .name = "L2TP/IPv6",
711 .owner = THIS_MODULE,
712 .init = l2tp_ip6_open,
713 .close = l2tp_ip6_close,
714 .bind = l2tp_ip6_bind,
715 .connect = l2tp_ip6_connect,
716 .disconnect = l2tp_ip6_disconnect,
717 .ioctl = udp_ioctl,
718 .destroy = l2tp_ip6_destroy_sock,
719 .setsockopt = ipv6_setsockopt,
720 .getsockopt = ipv6_getsockopt,
721 .sendmsg = l2tp_ip6_sendmsg,
722 .recvmsg = l2tp_ip6_recvmsg,
723 .backlog_rcv = l2tp_ip6_backlog_recv,
724 .hash = inet6_hash,
725 .unhash = inet_unhash,
726 .obj_size = sizeof(struct l2tp_ip6_sock),
727#ifdef CONFIG_COMPAT
728 .compat_setsockopt = compat_ipv6_setsockopt,
729 .compat_getsockopt = compat_ipv6_getsockopt,
730#endif
731};
732
733static const struct proto_ops l2tp_ip6_ops = {
734 .family = PF_INET6,
735 .owner = THIS_MODULE,
736 .release = inet6_release,
737 .bind = inet6_bind,
738 .connect = inet_dgram_connect,
739 .socketpair = sock_no_socketpair,
740 .accept = sock_no_accept,
741 .getname = l2tp_ip6_getname,
742 .poll = datagram_poll,
743 .ioctl = inet6_ioctl,
744 .listen = sock_no_listen,
745 .shutdown = inet_shutdown,
746 .setsockopt = sock_common_setsockopt,
747 .getsockopt = sock_common_getsockopt,
748 .sendmsg = inet_sendmsg,
749 .recvmsg = sock_common_recvmsg,
750 .mmap = sock_no_mmap,
751 .sendpage = sock_no_sendpage,
752#ifdef CONFIG_COMPAT
753 .compat_setsockopt = compat_sock_common_setsockopt,
754 .compat_getsockopt = compat_sock_common_getsockopt,
755#endif
756};
757
758static struct inet_protosw l2tp_ip6_protosw = {
759 .type = SOCK_DGRAM,
760 .protocol = IPPROTO_L2TP,
761 .prot = &l2tp_ip6_prot,
762 .ops = &l2tp_ip6_ops,
763};
764
765static struct inet6_protocol l2tp_ip6_protocol __read_mostly = {
766 .handler = l2tp_ip6_recv,
767};
768
769static int __init l2tp_ip6_init(void)
770{
771 int err;
772
773 pr_info("L2TP IP encapsulation support for IPv6 (L2TPv3)\n");
774
775 err = proto_register(&l2tp_ip6_prot, 1);
776 if (err != 0)
777 goto out;
778
779 err = inet6_add_protocol(&l2tp_ip6_protocol, IPPROTO_L2TP);
780 if (err)
781 goto out1;
782
783 inet6_register_protosw(&l2tp_ip6_protosw);
784 return 0;
785
786out1:
787 proto_unregister(&l2tp_ip6_prot);
788out:
789 return err;
790}
791
792static void __exit l2tp_ip6_exit(void)
793{
794 inet6_unregister_protosw(&l2tp_ip6_protosw);
795 inet6_del_protocol(&l2tp_ip6_protocol, IPPROTO_L2TP);
796 proto_unregister(&l2tp_ip6_prot);
797}
798
799module_init(l2tp_ip6_init);
800module_exit(l2tp_ip6_exit);
801
802MODULE_LICENSE("GPL");
803MODULE_AUTHOR("Chris Elston <celston@katalix.com>");
804MODULE_DESCRIPTION("L2TP IP encapsulation for IPv6");
805MODULE_VERSION("1.0");
806
807/* Use the value of SOCK_DGRAM (2) directory, because __stringify doesn't like
808 * enums
809 */
810MODULE_ALIAS_NET_PF_PROTO_TYPE(PF_INET6, 2, IPPROTO_L2TP);
811MODULE_ALIAS_NET_PF_PROTO(PF_INET6, IPPROTO_L2TP);