blob: 35e1e4bde58730d8395e2870d552230bca3a9c3d [file] [log] [blame]
Chris Elstona32e0ee2012-04-29 21:48:54 +00001/*
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
Joe Perchesa4ca44f2012-05-16 09:55:56 +000012#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
13
Chris Elstona32e0ee2012-04-29 21:48:54 +000014#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/tcp_states.h>
29#include <net/protocol.h>
30#include <net/xfrm.h>
31
32#include <net/transp_v6.h>
33#include <net/addrconf.h>
34#include <net/ip6_route.h>
35
36#include "l2tp_core.h"
37
38struct l2tp_ip6_sock {
39 /* inet_sock has to be the first member of l2tp_ip6_sock */
40 struct inet_sock inet;
41
42 u32 conn_id;
43 u32 peer_conn_id;
44
45 /* ipv6_pinfo has to be the last member of l2tp_ip6_sock, see
46 inet6_sk_generic */
47 struct ipv6_pinfo inet6;
48};
49
50static DEFINE_RWLOCK(l2tp_ip6_lock);
51static struct hlist_head l2tp_ip6_table;
52static struct hlist_head l2tp_ip6_bind_table;
53
54static inline struct l2tp_ip6_sock *l2tp_ip6_sk(const struct sock *sk)
55{
56 return (struct l2tp_ip6_sock *)sk;
57}
58
59static struct sock *__l2tp_ip6_bind_lookup(struct net *net,
60 struct in6_addr *laddr,
61 int dif, u32 tunnel_id)
62{
63 struct hlist_node *node;
64 struct sock *sk;
65
66 sk_for_each_bound(sk, node, &l2tp_ip6_bind_table) {
67 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;
Chris Elstona32e0ee2012-04-29 21:48:54 +0000138
139 /* Point to L2TP header */
140 optr = ptr = skb->data;
141
142 if (!pskb_may_pull(skb, 4))
143 goto discard;
144
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(&init_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
Joe Perchesa4ca44f2012-05-16 09:55:56 +0000172 pr_debug("%s: ip recv\n", tunnel->name);
173 print_hex_dump_bytes("", DUMP_PREFIX_OFFSET, ptr, length);
Chris Elstona32e0ee2012-04-29 21:48:54 +0000174 }
175
176 l2tp_recv_common(session, skb, ptr, optr, 0, skb->len,
177 tunnel->recv_payload_hook);
178 return 0;
179
180pass_up:
181 /* Get the tunnel_id from the L2TP header */
182 if (!pskb_may_pull(skb, 12))
183 goto discard;
184
185 if ((skb->data[0] & 0xc0) != 0xc0)
186 goto discard;
187
188 tunnel_id = ntohl(*(__be32 *) &skb->data[4]);
189 tunnel = l2tp_tunnel_find(&init_net, tunnel_id);
190 if (tunnel != NULL)
191 sk = tunnel->sock;
192 else {
193 struct ipv6hdr *iph = ipv6_hdr(skb);
194
195 read_lock_bh(&l2tp_ip6_lock);
196 sk = __l2tp_ip6_bind_lookup(&init_net, &iph->daddr,
197 0, tunnel_id);
198 read_unlock_bh(&l2tp_ip6_lock);
199 }
200
201 if (sk == NULL)
202 goto discard;
203
204 sock_hold(sk);
205
206 if (!xfrm6_policy_check(sk, XFRM_POLICY_IN, skb))
207 goto discard_put;
208
209 nf_reset(skb);
210
211 return sk_receive_skb(sk, skb, 1);
212
213discard_put:
214 sock_put(sk);
215
216discard:
217 kfree_skb(skb);
218 return 0;
219}
220
221static int l2tp_ip6_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_ip6_lock);
227 sk_add_node(sk, &l2tp_ip6_table);
228 write_unlock_bh(&l2tp_ip6_lock);
229
230 return 0;
231}
232
233static void l2tp_ip6_close(struct sock *sk, long timeout)
234{
235 write_lock_bh(&l2tp_ip6_lock);
236 hlist_del_init(&sk->sk_bind_node);
237 sk_del_node_init(sk);
238 write_unlock_bh(&l2tp_ip6_lock);
239
240 sk_common_release(sk);
241}
242
243static void l2tp_ip6_destroy_sock(struct sock *sk)
244{
245 lock_sock(sk);
246 ip6_flush_pending_frames(sk);
247 release_sock(sk);
248
249 inet6_destroy_sock(sk);
250}
251
252static int l2tp_ip6_bind(struct sock *sk, struct sockaddr *uaddr, int addr_len)
253{
254 struct inet_sock *inet = inet_sk(sk);
255 struct ipv6_pinfo *np = inet6_sk(sk);
256 struct sockaddr_l2tpip6 *addr = (struct sockaddr_l2tpip6 *) uaddr;
257 __be32 v4addr = 0;
258 int addr_type;
259 int err;
260
James Chapmanc51ce492012-05-29 03:30:42 +0000261 if (!sock_flag(sk, SOCK_ZAPPED))
262 return -EINVAL;
263 if (addr->l2tp_family != AF_INET6)
264 return -EINVAL;
Chris Elstona32e0ee2012-04-29 21:48:54 +0000265 if (addr_len < sizeof(*addr))
266 return -EINVAL;
267
268 addr_type = ipv6_addr_type(&addr->l2tp_addr);
269
270 /* l2tp_ip6 sockets are IPv6 only */
271 if (addr_type == IPV6_ADDR_MAPPED)
272 return -EADDRNOTAVAIL;
273
274 /* L2TP is point-point, not multicast */
275 if (addr_type & IPV6_ADDR_MULTICAST)
276 return -EADDRNOTAVAIL;
277
278 err = -EADDRINUSE;
279 read_lock_bh(&l2tp_ip6_lock);
280 if (__l2tp_ip6_bind_lookup(&init_net, &addr->l2tp_addr,
281 sk->sk_bound_dev_if, addr->l2tp_conn_id))
282 goto out_in_use;
283 read_unlock_bh(&l2tp_ip6_lock);
284
285 lock_sock(sk);
286
287 err = -EINVAL;
288 if (sk->sk_state != TCP_CLOSE)
289 goto out_unlock;
290
291 /* Check if the address belongs to the host. */
292 rcu_read_lock();
293 if (addr_type != IPV6_ADDR_ANY) {
294 struct net_device *dev = NULL;
295
296 if (addr_type & IPV6_ADDR_LINKLOCAL) {
297 if (addr_len >= sizeof(struct sockaddr_in6) &&
298 addr->l2tp_scope_id) {
299 /* Override any existing binding, if another
300 * one is supplied by user.
301 */
302 sk->sk_bound_dev_if = addr->l2tp_scope_id;
303 }
304
305 /* Binding to link-local address requires an
306 interface */
307 if (!sk->sk_bound_dev_if)
308 goto out_unlock_rcu;
309
310 err = -ENODEV;
311 dev = dev_get_by_index_rcu(sock_net(sk),
312 sk->sk_bound_dev_if);
313 if (!dev)
314 goto out_unlock_rcu;
315 }
316
317 /* ipv4 addr of the socket is invalid. Only the
318 * unspecified and mapped address have a v4 equivalent.
319 */
320 v4addr = LOOPBACK4_IPV6;
321 err = -EADDRNOTAVAIL;
322 if (!ipv6_chk_addr(sock_net(sk), &addr->l2tp_addr, dev, 0))
323 goto out_unlock_rcu;
324 }
325 rcu_read_unlock();
326
327 inet->inet_rcv_saddr = inet->inet_saddr = v4addr;
328 np->rcv_saddr = addr->l2tp_addr;
329 np->saddr = addr->l2tp_addr;
330
331 l2tp_ip6_sk(sk)->conn_id = addr->l2tp_conn_id;
332
333 write_lock_bh(&l2tp_ip6_lock);
334 sk_add_bind_node(sk, &l2tp_ip6_bind_table);
335 sk_del_node_init(sk);
336 write_unlock_bh(&l2tp_ip6_lock);
337
James Chapmanc51ce492012-05-29 03:30:42 +0000338 sock_reset_flag(sk, SOCK_ZAPPED);
Chris Elstona32e0ee2012-04-29 21:48:54 +0000339 release_sock(sk);
340 return 0;
341
342out_unlock_rcu:
343 rcu_read_unlock();
344out_unlock:
345 release_sock(sk);
346 return err;
347
348out_in_use:
349 read_unlock_bh(&l2tp_ip6_lock);
350 return err;
351}
352
353static int l2tp_ip6_connect(struct sock *sk, struct sockaddr *uaddr,
354 int addr_len)
355{
356 struct sockaddr_l2tpip6 *lsa = (struct sockaddr_l2tpip6 *) uaddr;
357 struct sockaddr_in6 *usin = (struct sockaddr_in6 *) uaddr;
358 struct in6_addr *daddr;
359 int addr_type;
360 int rc;
361
James Chapmanc51ce492012-05-29 03:30:42 +0000362 if (sock_flag(sk, SOCK_ZAPPED)) /* Must bind first - autobinding does not work */
363 return -EINVAL;
364
Chris Elstona32e0ee2012-04-29 21:48:54 +0000365 if (addr_len < sizeof(*lsa))
366 return -EINVAL;
367
368 addr_type = ipv6_addr_type(&usin->sin6_addr);
369 if (addr_type & IPV6_ADDR_MULTICAST)
370 return -EINVAL;
371
372 if (addr_type & IPV6_ADDR_MAPPED) {
373 daddr = &usin->sin6_addr;
374 if (ipv4_is_multicast(daddr->s6_addr32[3]))
375 return -EINVAL;
376 }
377
378 rc = ip6_datagram_connect(sk, uaddr, addr_len);
379
380 lock_sock(sk);
381
382 l2tp_ip6_sk(sk)->peer_conn_id = lsa->l2tp_conn_id;
383
384 write_lock_bh(&l2tp_ip6_lock);
385 hlist_del_init(&sk->sk_bind_node);
386 sk_add_bind_node(sk, &l2tp_ip6_bind_table);
387 write_unlock_bh(&l2tp_ip6_lock);
388
389 release_sock(sk);
390
391 return rc;
392}
393
James Chapmanc51ce492012-05-29 03:30:42 +0000394static int l2tp_ip6_disconnect(struct sock *sk, int flags)
395{
396 if (sock_flag(sk, SOCK_ZAPPED))
397 return 0;
398
399 return udp_disconnect(sk, flags);
400}
401
Chris Elstona32e0ee2012-04-29 21:48:54 +0000402static int l2tp_ip6_getname(struct socket *sock, struct sockaddr *uaddr,
403 int *uaddr_len, int peer)
404{
405 struct sockaddr_l2tpip6 *lsa = (struct sockaddr_l2tpip6 *)uaddr;
406 struct sock *sk = sock->sk;
407 struct ipv6_pinfo *np = inet6_sk(sk);
408 struct l2tp_ip6_sock *lsk = l2tp_ip6_sk(sk);
409
410 lsa->l2tp_family = AF_INET6;
411 lsa->l2tp_flowinfo = 0;
412 lsa->l2tp_scope_id = 0;
413 if (peer) {
414 if (!lsk->peer_conn_id)
415 return -ENOTCONN;
416 lsa->l2tp_conn_id = lsk->peer_conn_id;
417 lsa->l2tp_addr = np->daddr;
418 if (np->sndflow)
419 lsa->l2tp_flowinfo = np->flow_label;
420 } else {
421 if (ipv6_addr_any(&np->rcv_saddr))
422 lsa->l2tp_addr = np->saddr;
423 else
424 lsa->l2tp_addr = np->rcv_saddr;
425
426 lsa->l2tp_conn_id = lsk->conn_id;
427 }
428 if (ipv6_addr_type(&lsa->l2tp_addr) & IPV6_ADDR_LINKLOCAL)
429 lsa->l2tp_scope_id = sk->sk_bound_dev_if;
430 *uaddr_len = sizeof(*lsa);
431 return 0;
432}
433
434static int l2tp_ip6_backlog_recv(struct sock *sk, struct sk_buff *skb)
435{
436 int rc;
437
438 /* Charge it to the socket, dropping if the queue is full. */
439 rc = sock_queue_rcv_skb(sk, skb);
440 if (rc < 0)
441 goto drop;
442
443 return 0;
444
445drop:
446 IP_INC_STATS(&init_net, IPSTATS_MIB_INDISCARDS);
447 kfree_skb(skb);
448 return -1;
449}
450
451static int l2tp_ip6_push_pending_frames(struct sock *sk)
452{
453 struct sk_buff *skb;
454 __be32 *transhdr = NULL;
455 int err = 0;
456
457 skb = skb_peek(&sk->sk_write_queue);
458 if (skb == NULL)
459 goto out;
460
461 transhdr = (__be32 *)skb_transport_header(skb);
462 *transhdr = 0;
463
464 err = ip6_push_pending_frames(sk);
465
466out:
467 return err;
468}
469
470/* Userspace will call sendmsg() on the tunnel socket to send L2TP
471 * control frames.
472 */
473static int l2tp_ip6_sendmsg(struct kiocb *iocb, struct sock *sk,
474 struct msghdr *msg, size_t len)
475{
476 struct ipv6_txoptions opt_space;
477 struct sockaddr_l2tpip6 *lsa =
478 (struct sockaddr_l2tpip6 *) msg->msg_name;
479 struct in6_addr *daddr, *final_p, final;
480 struct ipv6_pinfo *np = inet6_sk(sk);
481 struct ipv6_txoptions *opt = NULL;
482 struct ip6_flowlabel *flowlabel = NULL;
483 struct dst_entry *dst = NULL;
484 struct flowi6 fl6;
485 int addr_len = msg->msg_namelen;
486 int hlimit = -1;
487 int tclass = -1;
488 int dontfrag = -1;
489 int transhdrlen = 4; /* zero session-id */
490 int ulen = len + transhdrlen;
491 int err;
492
493 /* Rough check on arithmetic overflow,
494 better check is made in ip6_append_data().
495 */
496 if (len > INT_MAX)
497 return -EMSGSIZE;
498
499 /* Mirror BSD error message compatibility */
500 if (msg->msg_flags & MSG_OOB)
501 return -EOPNOTSUPP;
502
503 /*
504 * Get and verify the address.
505 */
506 memset(&fl6, 0, sizeof(fl6));
507
508 fl6.flowi6_mark = sk->sk_mark;
509
510 if (lsa) {
511 if (addr_len < SIN6_LEN_RFC2133)
512 return -EINVAL;
513
514 if (lsa->l2tp_family && lsa->l2tp_family != AF_INET6)
515 return -EAFNOSUPPORT;
516
517 daddr = &lsa->l2tp_addr;
518 if (np->sndflow) {
519 fl6.flowlabel = lsa->l2tp_flowinfo & IPV6_FLOWINFO_MASK;
520 if (fl6.flowlabel&IPV6_FLOWLABEL_MASK) {
521 flowlabel = fl6_sock_lookup(sk, fl6.flowlabel);
522 if (flowlabel == NULL)
523 return -EINVAL;
524 daddr = &flowlabel->dst;
525 }
526 }
527
528 /*
529 * Otherwise it will be difficult to maintain
530 * sk->sk_dst_cache.
531 */
532 if (sk->sk_state == TCP_ESTABLISHED &&
533 ipv6_addr_equal(daddr, &np->daddr))
534 daddr = &np->daddr;
535
536 if (addr_len >= sizeof(struct sockaddr_in6) &&
537 lsa->l2tp_scope_id &&
538 ipv6_addr_type(daddr) & IPV6_ADDR_LINKLOCAL)
539 fl6.flowi6_oif = lsa->l2tp_scope_id;
540 } else {
541 if (sk->sk_state != TCP_ESTABLISHED)
542 return -EDESTADDRREQ;
543
544 daddr = &np->daddr;
545 fl6.flowlabel = np->flow_label;
546 }
547
548 if (fl6.flowi6_oif == 0)
549 fl6.flowi6_oif = sk->sk_bound_dev_if;
550
551 if (msg->msg_controllen) {
552 opt = &opt_space;
553 memset(opt, 0, sizeof(struct ipv6_txoptions));
554 opt->tot_len = sizeof(struct ipv6_txoptions);
555
556 err = datagram_send_ctl(sock_net(sk), sk, msg, &fl6, opt,
557 &hlimit, &tclass, &dontfrag);
558 if (err < 0) {
559 fl6_sock_release(flowlabel);
560 return err;
561 }
562 if ((fl6.flowlabel & IPV6_FLOWLABEL_MASK) && !flowlabel) {
563 flowlabel = fl6_sock_lookup(sk, fl6.flowlabel);
564 if (flowlabel == NULL)
565 return -EINVAL;
566 }
567 if (!(opt->opt_nflen|opt->opt_flen))
568 opt = NULL;
569 }
570
571 if (opt == NULL)
572 opt = np->opt;
573 if (flowlabel)
574 opt = fl6_merge_options(&opt_space, flowlabel, opt);
575 opt = ipv6_fixup_options(&opt_space, opt);
576
577 fl6.flowi6_proto = sk->sk_protocol;
578 if (!ipv6_addr_any(daddr))
579 fl6.daddr = *daddr;
580 else
581 fl6.daddr.s6_addr[15] = 0x1; /* :: means loopback (BSD'ism) */
582 if (ipv6_addr_any(&fl6.saddr) && !ipv6_addr_any(&np->saddr))
583 fl6.saddr = np->saddr;
584
585 final_p = fl6_update_dst(&fl6, opt, &final);
586
587 if (!fl6.flowi6_oif && ipv6_addr_is_multicast(&fl6.daddr))
588 fl6.flowi6_oif = np->mcast_oif;
589 else if (!fl6.flowi6_oif)
590 fl6.flowi6_oif = np->ucast_oif;
591
592 security_sk_classify_flow(sk, flowi6_to_flowi(&fl6));
593
594 dst = ip6_dst_lookup_flow(sk, &fl6, final_p, true);
595 if (IS_ERR(dst)) {
596 err = PTR_ERR(dst);
597 goto out;
598 }
599
600 if (hlimit < 0) {
601 if (ipv6_addr_is_multicast(&fl6.daddr))
602 hlimit = np->mcast_hops;
603 else
604 hlimit = np->hop_limit;
605 if (hlimit < 0)
606 hlimit = ip6_dst_hoplimit(dst);
607 }
608
609 if (tclass < 0)
610 tclass = np->tclass;
611
612 if (dontfrag < 0)
613 dontfrag = np->dontfrag;
614
615 if (msg->msg_flags & MSG_CONFIRM)
616 goto do_confirm;
617
618back_from_confirm:
619 lock_sock(sk);
620 err = ip6_append_data(sk, ip_generic_getfrag, msg->msg_iov,
621 ulen, transhdrlen, hlimit, tclass, opt,
622 &fl6, (struct rt6_info *)dst,
623 msg->msg_flags, dontfrag);
624 if (err)
625 ip6_flush_pending_frames(sk);
626 else if (!(msg->msg_flags & MSG_MORE))
627 err = l2tp_ip6_push_pending_frames(sk);
628 release_sock(sk);
629done:
630 dst_release(dst);
631out:
632 fl6_sock_release(flowlabel);
633
634 return err < 0 ? err : len;
635
636do_confirm:
637 dst_confirm(dst);
638 if (!(msg->msg_flags & MSG_PROBE) || len)
639 goto back_from_confirm;
640 err = 0;
641 goto done;
642}
643
644static int l2tp_ip6_recvmsg(struct kiocb *iocb, struct sock *sk,
645 struct msghdr *msg, size_t len, int noblock,
646 int flags, int *addr_len)
647{
648 struct inet_sock *inet = inet_sk(sk);
649 struct sockaddr_l2tpip6 *lsa = (struct sockaddr_l2tpip6 *)msg->msg_name;
650 size_t copied = 0;
651 int err = -EOPNOTSUPP;
652 struct sk_buff *skb;
653
654 if (flags & MSG_OOB)
655 goto out;
656
657 if (addr_len)
658 *addr_len = sizeof(*lsa);
659
660 if (flags & MSG_ERRQUEUE)
661 return ipv6_recv_error(sk, msg, len);
662
663 skb = skb_recv_datagram(sk, flags, noblock, &err);
664 if (!skb)
665 goto out;
666
667 copied = skb->len;
668 if (len < copied) {
669 msg->msg_flags |= MSG_TRUNC;
670 copied = len;
671 }
672
673 err = skb_copy_datagram_iovec(skb, 0, msg->msg_iov, copied);
674 if (err)
675 goto done;
676
677 sock_recv_timestamp(msg, sk, skb);
678
679 /* Copy the address. */
680 if (lsa) {
681 lsa->l2tp_family = AF_INET6;
682 lsa->l2tp_unused = 0;
683 lsa->l2tp_addr = ipv6_hdr(skb)->saddr;
684 lsa->l2tp_flowinfo = 0;
685 lsa->l2tp_scope_id = 0;
686 if (ipv6_addr_type(&lsa->l2tp_addr) & IPV6_ADDR_LINKLOCAL)
687 lsa->l2tp_scope_id = IP6CB(skb)->iif;
688 }
689
690 if (inet->cmsg_flags)
691 ip_cmsg_recv(msg, skb);
692
693 if (flags & MSG_TRUNC)
694 copied = skb->len;
695done:
696 skb_free_datagram(sk, skb);
697out:
698 return err ? err : copied;
699}
700
701static struct proto l2tp_ip6_prot = {
702 .name = "L2TP/IPv6",
703 .owner = THIS_MODULE,
704 .init = l2tp_ip6_open,
705 .close = l2tp_ip6_close,
706 .bind = l2tp_ip6_bind,
707 .connect = l2tp_ip6_connect,
James Chapmanc51ce492012-05-29 03:30:42 +0000708 .disconnect = l2tp_ip6_disconnect,
Chris Elstona32e0ee2012-04-29 21:48:54 +0000709 .ioctl = udp_ioctl,
710 .destroy = l2tp_ip6_destroy_sock,
711 .setsockopt = ipv6_setsockopt,
712 .getsockopt = ipv6_getsockopt,
713 .sendmsg = l2tp_ip6_sendmsg,
714 .recvmsg = l2tp_ip6_recvmsg,
715 .backlog_rcv = l2tp_ip6_backlog_recv,
716 .hash = inet_hash,
717 .unhash = inet_unhash,
718 .obj_size = sizeof(struct l2tp_ip6_sock),
719#ifdef CONFIG_COMPAT
720 .compat_setsockopt = compat_ipv6_setsockopt,
721 .compat_getsockopt = compat_ipv6_getsockopt,
722#endif
723};
724
725static const struct proto_ops l2tp_ip6_ops = {
726 .family = PF_INET6,
727 .owner = THIS_MODULE,
728 .release = inet6_release,
729 .bind = inet6_bind,
730 .connect = inet_dgram_connect,
731 .socketpair = sock_no_socketpair,
732 .accept = sock_no_accept,
733 .getname = l2tp_ip6_getname,
734 .poll = datagram_poll,
735 .ioctl = inet6_ioctl,
736 .listen = sock_no_listen,
737 .shutdown = inet_shutdown,
738 .setsockopt = sock_common_setsockopt,
739 .getsockopt = sock_common_getsockopt,
740 .sendmsg = inet_sendmsg,
741 .recvmsg = sock_common_recvmsg,
742 .mmap = sock_no_mmap,
743 .sendpage = sock_no_sendpage,
744#ifdef CONFIG_COMPAT
745 .compat_setsockopt = compat_sock_common_setsockopt,
746 .compat_getsockopt = compat_sock_common_getsockopt,
747#endif
748};
749
750static struct inet_protosw l2tp_ip6_protosw = {
751 .type = SOCK_DGRAM,
752 .protocol = IPPROTO_L2TP,
753 .prot = &l2tp_ip6_prot,
754 .ops = &l2tp_ip6_ops,
755 .no_check = 0,
756};
757
758static struct inet6_protocol l2tp_ip6_protocol __read_mostly = {
759 .handler = l2tp_ip6_recv,
760};
761
762static int __init l2tp_ip6_init(void)
763{
764 int err;
765
Joe Perchesa4ca44f2012-05-16 09:55:56 +0000766 pr_info("L2TP IP encapsulation support for IPv6 (L2TPv3)\n");
Chris Elstona32e0ee2012-04-29 21:48:54 +0000767
768 err = proto_register(&l2tp_ip6_prot, 1);
769 if (err != 0)
770 goto out;
771
772 err = inet6_add_protocol(&l2tp_ip6_protocol, IPPROTO_L2TP);
773 if (err)
774 goto out1;
775
776 inet6_register_protosw(&l2tp_ip6_protosw);
777 return 0;
778
779out1:
780 proto_unregister(&l2tp_ip6_prot);
781out:
782 return err;
783}
784
785static void __exit l2tp_ip6_exit(void)
786{
787 inet6_unregister_protosw(&l2tp_ip6_protosw);
788 inet6_del_protocol(&l2tp_ip6_protocol, IPPROTO_L2TP);
789 proto_unregister(&l2tp_ip6_prot);
790}
791
792module_init(l2tp_ip6_init);
793module_exit(l2tp_ip6_exit);
794
795MODULE_LICENSE("GPL");
796MODULE_AUTHOR("Chris Elston <celston@katalix.com>");
797MODULE_DESCRIPTION("L2TP IP encapsulation for IPv6");
798MODULE_VERSION("1.0");
799
800/* Use the value of SOCK_DGRAM (2) directory, because __stringify doesn't like
801 * enums
802 */
803MODULE_ALIAS_NET_PF_PROTO_TYPE(PF_INET6, 2, IPPROTO_L2TP);