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
39 struct 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
51 static DEFINE_RWLOCK(l2tp_ip6_lock);
52 static struct hlist_head l2tp_ip6_table;
53 static struct hlist_head l2tp_ip6_bind_table;
54
55 static inline struct l2tp_ip6_sock *l2tp_ip6_sk(const struct sock *sk)
56 {
57 return (struct l2tp_ip6_sock *)sk;
58 }
59
60 static 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;
81 found:
82 return sk;
83 }
84
85 static 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 */
129 static int l2tp_ip6_recv(struct sk_buff *skb)
130 {
131 struct net *net = dev_net(skb->dev);
132 struct sock *sk;
133 u32 session_id;
134 u32 tunnel_id;
135 unsigned char *ptr, *optr;
136 struct l2tp_session *session;
137 struct l2tp_tunnel *tunnel = NULL;
138 int length;
139
140 if (!pskb_may_pull(skb, 4))
141 goto discard;
142
143 /* Point to L2TP header */
144 optr = ptr = skb->data;
145 session_id = ntohl(*((__be32 *) ptr));
146 ptr += 4;
147
148 /* RFC3931: L2TP/IP packets have the first 4 bytes containing
149 * the session_id. If it is 0, the packet is a L2TP control
150 * frame and the session_id value can be discarded.
151 */
152 if (session_id == 0) {
153 __skb_pull(skb, 4);
154 goto pass_up;
155 }
156
157 /* Ok, this is a data packet. Lookup the session. */
158 session = l2tp_session_find(net, NULL, session_id);
159 if (session == NULL)
160 goto discard;
161
162 tunnel = session->tunnel;
163 if (tunnel == NULL)
164 goto discard;
165
166 /* Trace packet contents, if enabled */
167 if (tunnel->debug & L2TP_MSG_DATA) {
168 length = min(32u, skb->len);
169 if (!pskb_may_pull(skb, length))
170 goto discard;
171
172 /* Point to L2TP header */
173 optr = ptr = skb->data;
174 ptr += 4;
175 pr_debug("%s: ip recv\n", tunnel->name);
176 print_hex_dump_bytes("", DUMP_PREFIX_OFFSET, ptr, length);
177 }
178
179 l2tp_recv_common(session, skb, ptr, optr, 0, skb->len,
180 tunnel->recv_payload_hook);
181 return 0;
182
183 pass_up:
184 /* Get the tunnel_id from the L2TP header */
185 if (!pskb_may_pull(skb, 12))
186 goto discard;
187
188 if ((skb->data[0] & 0xc0) != 0xc0)
189 goto discard;
190
191 tunnel_id = ntohl(*(__be32 *) &skb->data[4]);
192 tunnel = l2tp_tunnel_find(net, tunnel_id);
193 if (tunnel != NULL)
194 sk = tunnel->sock;
195 else {
196 struct ipv6hdr *iph = ipv6_hdr(skb);
197
198 read_lock_bh(&l2tp_ip6_lock);
199 sk = __l2tp_ip6_bind_lookup(net, &iph->daddr,
200 0, tunnel_id);
201 read_unlock_bh(&l2tp_ip6_lock);
202 }
203
204 if (sk == NULL)
205 goto discard;
206
207 sock_hold(sk);
208
209 if (!xfrm6_policy_check(sk, XFRM_POLICY_IN, skb))
210 goto discard_put;
211
212 nf_reset(skb);
213
214 return sk_receive_skb(sk, skb, 1);
215
216 discard_put:
217 sock_put(sk);
218
219 discard:
220 kfree_skb(skb);
221 return 0;
222 }
223
224 static int l2tp_ip6_open(struct sock *sk)
225 {
226 /* Prevent autobind. We don't have ports. */
227 inet_sk(sk)->inet_num = IPPROTO_L2TP;
228
229 write_lock_bh(&l2tp_ip6_lock);
230 sk_add_node(sk, &l2tp_ip6_table);
231 write_unlock_bh(&l2tp_ip6_lock);
232
233 return 0;
234 }
235
236 static void l2tp_ip6_close(struct sock *sk, long timeout)
237 {
238 write_lock_bh(&l2tp_ip6_lock);
239 hlist_del_init(&sk->sk_bind_node);
240 sk_del_node_init(sk);
241 write_unlock_bh(&l2tp_ip6_lock);
242
243 sk_common_release(sk);
244 }
245
246 static void l2tp_ip6_destroy_sock(struct sock *sk)
247 {
248 struct l2tp_tunnel *tunnel = l2tp_sock_to_tunnel(sk);
249
250 lock_sock(sk);
251 ip6_flush_pending_frames(sk);
252 release_sock(sk);
253
254 if (tunnel) {
255 l2tp_tunnel_closeall(tunnel);
256 sock_put(sk);
257 }
258
259 inet6_destroy_sock(sk);
260 }
261
262 static int l2tp_ip6_bind(struct sock *sk, struct sockaddr *uaddr, int addr_len)
263 {
264 struct inet_sock *inet = inet_sk(sk);
265 struct ipv6_pinfo *np = inet6_sk(sk);
266 struct sockaddr_l2tpip6 *addr = (struct sockaddr_l2tpip6 *) uaddr;
267 struct net *net = sock_net(sk);
268 __be32 v4addr = 0;
269 int addr_type;
270 int err;
271
272 if (!sock_flag(sk, SOCK_ZAPPED))
273 return -EINVAL;
274 if (addr->l2tp_family != AF_INET6)
275 return -EINVAL;
276 if (addr_len < sizeof(*addr))
277 return -EINVAL;
278
279 addr_type = ipv6_addr_type(&addr->l2tp_addr);
280
281 /* l2tp_ip6 sockets are IPv6 only */
282 if (addr_type == IPV6_ADDR_MAPPED)
283 return -EADDRNOTAVAIL;
284
285 /* L2TP is point-point, not multicast */
286 if (addr_type & IPV6_ADDR_MULTICAST)
287 return -EADDRNOTAVAIL;
288
289 err = -EADDRINUSE;
290 read_lock_bh(&l2tp_ip6_lock);
291 if (__l2tp_ip6_bind_lookup(net, &addr->l2tp_addr,
292 sk->sk_bound_dev_if, addr->l2tp_conn_id))
293 goto out_in_use;
294 read_unlock_bh(&l2tp_ip6_lock);
295
296 lock_sock(sk);
297
298 err = -EINVAL;
299 if (sk->sk_state != TCP_CLOSE)
300 goto out_unlock;
301
302 /* Check if the address belongs to the host. */
303 rcu_read_lock();
304 if (addr_type != IPV6_ADDR_ANY) {
305 struct net_device *dev = NULL;
306
307 if (addr_type & IPV6_ADDR_LINKLOCAL) {
308 if (addr_len >= sizeof(struct sockaddr_in6) &&
309 addr->l2tp_scope_id) {
310 /* Override any existing binding, if another
311 * one is supplied by user.
312 */
313 sk->sk_bound_dev_if = addr->l2tp_scope_id;
314 }
315
316 /* Binding to link-local address requires an
317 interface */
318 if (!sk->sk_bound_dev_if)
319 goto out_unlock_rcu;
320
321 err = -ENODEV;
322 dev = dev_get_by_index_rcu(sock_net(sk),
323 sk->sk_bound_dev_if);
324 if (!dev)
325 goto out_unlock_rcu;
326 }
327
328 /* ipv4 addr of the socket is invalid. Only the
329 * unspecified and mapped address have a v4 equivalent.
330 */
331 v4addr = LOOPBACK4_IPV6;
332 err = -EADDRNOTAVAIL;
333 if (!ipv6_chk_addr(sock_net(sk), &addr->l2tp_addr, dev, 0))
334 goto out_unlock_rcu;
335 }
336 rcu_read_unlock();
337
338 inet->inet_rcv_saddr = inet->inet_saddr = v4addr;
339 sk->sk_v6_rcv_saddr = addr->l2tp_addr;
340 np->saddr = addr->l2tp_addr;
341
342 l2tp_ip6_sk(sk)->conn_id = addr->l2tp_conn_id;
343
344 write_lock_bh(&l2tp_ip6_lock);
345 sk_add_bind_node(sk, &l2tp_ip6_bind_table);
346 sk_del_node_init(sk);
347 write_unlock_bh(&l2tp_ip6_lock);
348
349 sock_reset_flag(sk, SOCK_ZAPPED);
350 release_sock(sk);
351 return 0;
352
353 out_unlock_rcu:
354 rcu_read_unlock();
355 out_unlock:
356 release_sock(sk);
357 return err;
358
359 out_in_use:
360 read_unlock_bh(&l2tp_ip6_lock);
361 return err;
362 }
363
364 static int l2tp_ip6_connect(struct sock *sk, struct sockaddr *uaddr,
365 int addr_len)
366 {
367 struct sockaddr_l2tpip6 *lsa = (struct sockaddr_l2tpip6 *) uaddr;
368 struct sockaddr_in6 *usin = (struct sockaddr_in6 *) uaddr;
369 struct in6_addr *daddr;
370 int addr_type;
371 int rc;
372
373 if (sock_flag(sk, SOCK_ZAPPED)) /* Must bind first - autobinding does not work */
374 return -EINVAL;
375
376 if (addr_len < sizeof(*lsa))
377 return -EINVAL;
378
379 if (usin->sin6_family != AF_INET6)
380 return -EINVAL;
381
382 addr_type = ipv6_addr_type(&usin->sin6_addr);
383 if (addr_type & IPV6_ADDR_MULTICAST)
384 return -EINVAL;
385
386 if (addr_type & IPV6_ADDR_MAPPED) {
387 daddr = &usin->sin6_addr;
388 if (ipv4_is_multicast(daddr->s6_addr32[3]))
389 return -EINVAL;
390 }
391
392 rc = ip6_datagram_connect(sk, uaddr, addr_len);
393
394 lock_sock(sk);
395
396 l2tp_ip6_sk(sk)->peer_conn_id = lsa->l2tp_conn_id;
397
398 write_lock_bh(&l2tp_ip6_lock);
399 hlist_del_init(&sk->sk_bind_node);
400 sk_add_bind_node(sk, &l2tp_ip6_bind_table);
401 write_unlock_bh(&l2tp_ip6_lock);
402
403 release_sock(sk);
404
405 return rc;
406 }
407
408 static int l2tp_ip6_disconnect(struct sock *sk, int flags)
409 {
410 if (sock_flag(sk, SOCK_ZAPPED))
411 return 0;
412
413 return udp_disconnect(sk, flags);
414 }
415
416 static int l2tp_ip6_getname(struct socket *sock, struct sockaddr *uaddr,
417 int *uaddr_len, int peer)
418 {
419 struct sockaddr_l2tpip6 *lsa = (struct sockaddr_l2tpip6 *)uaddr;
420 struct sock *sk = sock->sk;
421 struct ipv6_pinfo *np = inet6_sk(sk);
422 struct l2tp_ip6_sock *lsk = l2tp_ip6_sk(sk);
423
424 lsa->l2tp_family = AF_INET6;
425 lsa->l2tp_flowinfo = 0;
426 lsa->l2tp_scope_id = 0;
427 lsa->l2tp_unused = 0;
428 if (peer) {
429 if (!lsk->peer_conn_id)
430 return -ENOTCONN;
431 lsa->l2tp_conn_id = lsk->peer_conn_id;
432 lsa->l2tp_addr = sk->sk_v6_daddr;
433 if (np->sndflow)
434 lsa->l2tp_flowinfo = np->flow_label;
435 } else {
436 if (ipv6_addr_any(&sk->sk_v6_rcv_saddr))
437 lsa->l2tp_addr = np->saddr;
438 else
439 lsa->l2tp_addr = sk->sk_v6_rcv_saddr;
440
441 lsa->l2tp_conn_id = lsk->conn_id;
442 }
443 if (ipv6_addr_type(&lsa->l2tp_addr) & IPV6_ADDR_LINKLOCAL)
444 lsa->l2tp_scope_id = sk->sk_bound_dev_if;
445 *uaddr_len = sizeof(*lsa);
446 return 0;
447 }
448
449 static int l2tp_ip6_backlog_recv(struct sock *sk, struct sk_buff *skb)
450 {
451 int rc;
452
453 /* Charge it to the socket, dropping if the queue is full. */
454 rc = sock_queue_rcv_skb(sk, skb);
455 if (rc < 0)
456 goto drop;
457
458 return 0;
459
460 drop:
461 IP_INC_STATS(sock_net(sk), IPSTATS_MIB_INDISCARDS);
462 kfree_skb(skb);
463 return -1;
464 }
465
466 static int l2tp_ip6_push_pending_frames(struct sock *sk)
467 {
468 struct sk_buff *skb;
469 __be32 *transhdr = NULL;
470 int err = 0;
471
472 skb = skb_peek(&sk->sk_write_queue);
473 if (skb == NULL)
474 goto out;
475
476 transhdr = (__be32 *)skb_transport_header(skb);
477 *transhdr = 0;
478
479 err = ip6_push_pending_frames(sk);
480
481 out:
482 return err;
483 }
484
485 /* Userspace will call sendmsg() on the tunnel socket to send L2TP
486 * control frames.
487 */
488 static int l2tp_ip6_sendmsg(struct sock *sk, struct msghdr *msg, size_t len)
489 {
490 struct ipv6_txoptions opt_space;
491 DECLARE_SOCKADDR(struct sockaddr_l2tpip6 *, lsa, msg->msg_name);
492 struct in6_addr *daddr, *final_p, final;
493 struct ipv6_pinfo *np = inet6_sk(sk);
494 struct ipv6_txoptions *opt_to_free = NULL;
495 struct ipv6_txoptions *opt = NULL;
496 struct ip6_flowlabel *flowlabel = NULL;
497 struct dst_entry *dst = NULL;
498 struct flowi6 fl6;
499 struct sockcm_cookie sockc_unused = {0};
500 struct ipcm6_cookie ipc6;
501 int addr_len = msg->msg_namelen;
502 int transhdrlen = 4; /* zero session-id */
503 int ulen = len + transhdrlen;
504 int err;
505
506 /* Rough check on arithmetic overflow,
507 better check is made in ip6_append_data().
508 */
509 if (len > INT_MAX)
510 return -EMSGSIZE;
511
512 /* Mirror BSD error message compatibility */
513 if (msg->msg_flags & MSG_OOB)
514 return -EOPNOTSUPP;
515
516 /*
517 * Get and verify the address.
518 */
519 memset(&fl6, 0, sizeof(fl6));
520
521 fl6.flowi6_mark = sk->sk_mark;
522
523 ipc6.hlimit = -1;
524 ipc6.tclass = -1;
525 ipc6.dontfrag = -1;
526
527 if (lsa) {
528 if (addr_len < SIN6_LEN_RFC2133)
529 return -EINVAL;
530
531 if (lsa->l2tp_family && lsa->l2tp_family != AF_INET6)
532 return -EAFNOSUPPORT;
533
534 daddr = &lsa->l2tp_addr;
535 if (np->sndflow) {
536 fl6.flowlabel = lsa->l2tp_flowinfo & IPV6_FLOWINFO_MASK;
537 if (fl6.flowlabel&IPV6_FLOWLABEL_MASK) {
538 flowlabel = fl6_sock_lookup(sk, fl6.flowlabel);
539 if (flowlabel == NULL)
540 return -EINVAL;
541 }
542 }
543
544 /*
545 * Otherwise it will be difficult to maintain
546 * sk->sk_dst_cache.
547 */
548 if (sk->sk_state == TCP_ESTABLISHED &&
549 ipv6_addr_equal(daddr, &sk->sk_v6_daddr))
550 daddr = &sk->sk_v6_daddr;
551
552 if (addr_len >= sizeof(struct sockaddr_in6) &&
553 lsa->l2tp_scope_id &&
554 ipv6_addr_type(daddr) & IPV6_ADDR_LINKLOCAL)
555 fl6.flowi6_oif = lsa->l2tp_scope_id;
556 } else {
557 if (sk->sk_state != TCP_ESTABLISHED)
558 return -EDESTADDRREQ;
559
560 daddr = &sk->sk_v6_daddr;
561 fl6.flowlabel = np->flow_label;
562 }
563
564 if (fl6.flowi6_oif == 0)
565 fl6.flowi6_oif = sk->sk_bound_dev_if;
566
567 if (msg->msg_controllen) {
568 opt = &opt_space;
569 memset(opt, 0, sizeof(struct ipv6_txoptions));
570 opt->tot_len = sizeof(struct ipv6_txoptions);
571 ipc6.opt = opt;
572
573 err = ip6_datagram_send_ctl(sock_net(sk), sk, msg, &fl6, &ipc6,
574 &sockc_unused);
575 if (err < 0) {
576 fl6_sock_release(flowlabel);
577 return err;
578 }
579 if ((fl6.flowlabel & IPV6_FLOWLABEL_MASK) && !flowlabel) {
580 flowlabel = fl6_sock_lookup(sk, fl6.flowlabel);
581 if (flowlabel == NULL)
582 return -EINVAL;
583 }
584 if (!(opt->opt_nflen|opt->opt_flen))
585 opt = NULL;
586 }
587
588 if (!opt) {
589 opt = txopt_get(np);
590 opt_to_free = opt;
591 }
592 if (flowlabel)
593 opt = fl6_merge_options(&opt_space, flowlabel, opt);
594 opt = ipv6_fixup_options(&opt_space, opt);
595 ipc6.opt = opt;
596
597 fl6.flowi6_proto = sk->sk_protocol;
598 if (!ipv6_addr_any(daddr))
599 fl6.daddr = *daddr;
600 else
601 fl6.daddr.s6_addr[15] = 0x1; /* :: means loopback (BSD'ism) */
602 if (ipv6_addr_any(&fl6.saddr) && !ipv6_addr_any(&np->saddr))
603 fl6.saddr = np->saddr;
604
605 final_p = fl6_update_dst(&fl6, opt, &final);
606
607 if (!fl6.flowi6_oif && ipv6_addr_is_multicast(&fl6.daddr))
608 fl6.flowi6_oif = np->mcast_oif;
609 else if (!fl6.flowi6_oif)
610 fl6.flowi6_oif = np->ucast_oif;
611
612 security_sk_classify_flow(sk, flowi6_to_flowi(&fl6));
613
614 dst = ip6_dst_lookup_flow(sk, &fl6, final_p);
615 if (IS_ERR(dst)) {
616 err = PTR_ERR(dst);
617 goto out;
618 }
619
620 if (ipc6.hlimit < 0)
621 ipc6.hlimit = ip6_sk_dst_hoplimit(np, &fl6, dst);
622
623 if (ipc6.tclass < 0)
624 ipc6.tclass = np->tclass;
625
626 if (ipc6.dontfrag < 0)
627 ipc6.dontfrag = np->dontfrag;
628
629 if (msg->msg_flags & MSG_CONFIRM)
630 goto do_confirm;
631
632 back_from_confirm:
633 lock_sock(sk);
634 err = ip6_append_data(sk, ip_generic_getfrag, msg,
635 ulen, transhdrlen, &ipc6,
636 &fl6, (struct rt6_info *)dst,
637 msg->msg_flags, &sockc_unused);
638 if (err)
639 ip6_flush_pending_frames(sk);
640 else if (!(msg->msg_flags & MSG_MORE))
641 err = l2tp_ip6_push_pending_frames(sk);
642 release_sock(sk);
643 done:
644 dst_release(dst);
645 out:
646 fl6_sock_release(flowlabel);
647 txopt_put(opt_to_free);
648
649 return err < 0 ? err : len;
650
651 do_confirm:
652 dst_confirm(dst);
653 if (!(msg->msg_flags & MSG_PROBE) || len)
654 goto back_from_confirm;
655 err = 0;
656 goto done;
657 }
658
659 static int l2tp_ip6_recvmsg(struct sock *sk, struct msghdr *msg, size_t len,
660 int noblock, int flags, int *addr_len)
661 {
662 struct ipv6_pinfo *np = inet6_sk(sk);
663 DECLARE_SOCKADDR(struct sockaddr_l2tpip6 *, lsa, msg->msg_name);
664 size_t copied = 0;
665 int err = -EOPNOTSUPP;
666 struct sk_buff *skb;
667
668 if (flags & MSG_OOB)
669 goto out;
670
671 if (addr_len)
672 *addr_len = sizeof(*lsa);
673
674 if (flags & MSG_ERRQUEUE)
675 return ipv6_recv_error(sk, msg, len, addr_len);
676
677 skb = skb_recv_datagram(sk, flags, noblock, &err);
678 if (!skb)
679 goto out;
680
681 copied = skb->len;
682 if (len < copied) {
683 msg->msg_flags |= MSG_TRUNC;
684 copied = len;
685 }
686
687 err = skb_copy_datagram_msg(skb, 0, msg, copied);
688 if (err)
689 goto done;
690
691 sock_recv_timestamp(msg, sk, skb);
692
693 /* Copy the address. */
694 if (lsa) {
695 lsa->l2tp_family = AF_INET6;
696 lsa->l2tp_unused = 0;
697 lsa->l2tp_addr = ipv6_hdr(skb)->saddr;
698 lsa->l2tp_flowinfo = 0;
699 lsa->l2tp_scope_id = 0;
700 lsa->l2tp_conn_id = 0;
701 if (ipv6_addr_type(&lsa->l2tp_addr) & IPV6_ADDR_LINKLOCAL)
702 lsa->l2tp_scope_id = inet6_iif(skb);
703 }
704
705 if (np->rxopt.all)
706 ip6_datagram_recv_ctl(sk, msg, skb);
707
708 if (flags & MSG_TRUNC)
709 copied = skb->len;
710 done:
711 skb_free_datagram(sk, skb);
712 out:
713 return err ? err : copied;
714 }
715
716 static struct proto l2tp_ip6_prot = {
717 .name = "L2TP/IPv6",
718 .owner = THIS_MODULE,
719 .init = l2tp_ip6_open,
720 .close = l2tp_ip6_close,
721 .bind = l2tp_ip6_bind,
722 .connect = l2tp_ip6_connect,
723 .disconnect = l2tp_ip6_disconnect,
724 .ioctl = udp_ioctl,
725 .destroy = l2tp_ip6_destroy_sock,
726 .setsockopt = ipv6_setsockopt,
727 .getsockopt = ipv6_getsockopt,
728 .sendmsg = l2tp_ip6_sendmsg,
729 .recvmsg = l2tp_ip6_recvmsg,
730 .backlog_rcv = l2tp_ip6_backlog_recv,
731 .hash = inet6_hash,
732 .unhash = inet_unhash,
733 .obj_size = sizeof(struct l2tp_ip6_sock),
734 #ifdef CONFIG_COMPAT
735 .compat_setsockopt = compat_ipv6_setsockopt,
736 .compat_getsockopt = compat_ipv6_getsockopt,
737 #endif
738 };
739
740 static const struct proto_ops l2tp_ip6_ops = {
741 .family = PF_INET6,
742 .owner = THIS_MODULE,
743 .release = inet6_release,
744 .bind = inet6_bind,
745 .connect = inet_dgram_connect,
746 .socketpair = sock_no_socketpair,
747 .accept = sock_no_accept,
748 .getname = l2tp_ip6_getname,
749 .poll = datagram_poll,
750 .ioctl = inet6_ioctl,
751 .listen = sock_no_listen,
752 .shutdown = inet_shutdown,
753 .setsockopt = sock_common_setsockopt,
754 .getsockopt = sock_common_getsockopt,
755 .sendmsg = inet_sendmsg,
756 .recvmsg = sock_common_recvmsg,
757 .mmap = sock_no_mmap,
758 .sendpage = sock_no_sendpage,
759 #ifdef CONFIG_COMPAT
760 .compat_setsockopt = compat_sock_common_setsockopt,
761 .compat_getsockopt = compat_sock_common_getsockopt,
762 #endif
763 };
764
765 static struct inet_protosw l2tp_ip6_protosw = {
766 .type = SOCK_DGRAM,
767 .protocol = IPPROTO_L2TP,
768 .prot = &l2tp_ip6_prot,
769 .ops = &l2tp_ip6_ops,
770 };
771
772 static struct inet6_protocol l2tp_ip6_protocol __read_mostly = {
773 .handler = l2tp_ip6_recv,
774 };
775
776 static int __init l2tp_ip6_init(void)
777 {
778 int err;
779
780 pr_info("L2TP IP encapsulation support for IPv6 (L2TPv3)\n");
781
782 err = proto_register(&l2tp_ip6_prot, 1);
783 if (err != 0)
784 goto out;
785
786 err = inet6_add_protocol(&l2tp_ip6_protocol, IPPROTO_L2TP);
787 if (err)
788 goto out1;
789
790 inet6_register_protosw(&l2tp_ip6_protosw);
791 return 0;
792
793 out1:
794 proto_unregister(&l2tp_ip6_prot);
795 out:
796 return err;
797 }
798
799 static void __exit l2tp_ip6_exit(void)
800 {
801 inet6_unregister_protosw(&l2tp_ip6_protosw);
802 inet6_del_protocol(&l2tp_ip6_protocol, IPPROTO_L2TP);
803 proto_unregister(&l2tp_ip6_prot);
804 }
805
806 module_init(l2tp_ip6_init);
807 module_exit(l2tp_ip6_exit);
808
809 MODULE_LICENSE("GPL");
810 MODULE_AUTHOR("Chris Elston <celston@katalix.com>");
811 MODULE_DESCRIPTION("L2TP IP encapsulation for IPv6");
812 MODULE_VERSION("1.0");
813
814 /* Use the value of SOCK_DGRAM (2) directory, because __stringify doesn't like
815 * enums
816 */
817 MODULE_ALIAS_NET_PF_PROTO_TYPE(PF_INET6, 2, IPPROTO_L2TP);
818 MODULE_ALIAS_NET_PF_PROTO(PF_INET6, IPPROTO_L2TP);
819
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