blob: 8611f1b6314161d4df90c4969b3b9cb9066a446d [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{
Chris Elstona32e0ee2012-04-29 21:48:54 +000063 struct sock *sk;
64
Sasha Levinb67bfe02013-02-27 17:06:00 -080065 sk_for_each_bound(sk, &l2tp_ip6_bind_table) {
Eric Dumazetefe42082013-10-03 15:42:29 -070066 const struct in6_addr *addr = inet6_rcv_saddr(sk);
Chris Elstona32e0ee2012-04-29 21:48:54 +000067 struct l2tp_ip6_sock *l2tp = l2tp_ip6_sk(sk);
68
69 if (l2tp == NULL)
70 continue;
71
72 if ((l2tp->conn_id == tunnel_id) &&
73 net_eq(sock_net(sk), net) &&
74 !(addr && ipv6_addr_equal(addr, laddr)) &&
75 !(sk->sk_bound_dev_if && sk->sk_bound_dev_if != dif))
76 goto found;
77 }
78
79 sk = NULL;
80found:
81 return sk;
82}
83
84static inline struct sock *l2tp_ip6_bind_lookup(struct net *net,
85 struct in6_addr *laddr,
86 int dif, u32 tunnel_id)
87{
88 struct sock *sk = __l2tp_ip6_bind_lookup(net, laddr, dif, tunnel_id);
89 if (sk)
90 sock_hold(sk);
91
92 return sk;
93}
94
95/* When processing receive frames, there are two cases to
96 * consider. Data frames consist of a non-zero session-id and an
97 * optional cookie. Control frames consist of a regular L2TP header
98 * preceded by 32-bits of zeros.
99 *
100 * L2TPv3 Session Header Over IP
101 *
102 * 0 1 2 3
103 * 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
104 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
105 * | Session ID |
106 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
107 * | Cookie (optional, maximum 64 bits)...
108 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
109 * |
110 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
111 *
112 * L2TPv3 Control Message Header Over IP
113 *
114 * 0 1 2 3
115 * 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
116 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
117 * | (32 bits of zeros) |
118 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
119 * |T|L|x|x|S|x|x|x|x|x|x|x| Ver | Length |
120 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
121 * | Control Connection ID |
122 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
123 * | Ns | Nr |
124 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
125 *
126 * All control frames are passed to userspace.
127 */
128static int l2tp_ip6_recv(struct sk_buff *skb)
129{
130 struct sock *sk;
131 u32 session_id;
132 u32 tunnel_id;
133 unsigned char *ptr, *optr;
134 struct l2tp_session *session;
135 struct l2tp_tunnel *tunnel = NULL;
136 int length;
Chris Elstona32e0ee2012-04-29 21:48:54 +0000137
138 /* Point to L2TP header */
139 optr = ptr = skb->data;
140
141 if (!pskb_may_pull(skb, 4))
142 goto discard;
143
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
Joe Perchesa4ca44f2012-05-16 09:55:56 +0000171 pr_debug("%s: ip recv\n", tunnel->name);
172 print_hex_dump_bytes("", DUMP_PREFIX_OFFSET, ptr, length);
Chris Elstona32e0ee2012-04-29 21:48:54 +0000173 }
174
175 l2tp_recv_common(session, skb, ptr, optr, 0, skb->len,
176 tunnel->recv_payload_hook);
177 return 0;
178
179pass_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 ipv6hdr *iph = ipv6_hdr(skb);
193
194 read_lock_bh(&l2tp_ip6_lock);
195 sk = __l2tp_ip6_bind_lookup(&init_net, &iph->daddr,
196 0, tunnel_id);
197 read_unlock_bh(&l2tp_ip6_lock);
198 }
199
200 if (sk == NULL)
201 goto discard;
202
203 sock_hold(sk);
204
205 if (!xfrm6_policy_check(sk, XFRM_POLICY_IN, skb))
206 goto discard_put;
207
208 nf_reset(skb);
209
210 return sk_receive_skb(sk, skb, 1);
211
212discard_put:
213 sock_put(sk);
214
215discard:
216 kfree_skb(skb);
217 return 0;
218}
219
220static int l2tp_ip6_open(struct sock *sk)
221{
222 /* Prevent autobind. We don't have ports. */
223 inet_sk(sk)->inet_num = IPPROTO_L2TP;
224
225 write_lock_bh(&l2tp_ip6_lock);
226 sk_add_node(sk, &l2tp_ip6_table);
227 write_unlock_bh(&l2tp_ip6_lock);
228
229 return 0;
230}
231
232static void l2tp_ip6_close(struct sock *sk, long timeout)
233{
234 write_lock_bh(&l2tp_ip6_lock);
235 hlist_del_init(&sk->sk_bind_node);
236 sk_del_node_init(sk);
237 write_unlock_bh(&l2tp_ip6_lock);
238
239 sk_common_release(sk);
240}
241
242static void l2tp_ip6_destroy_sock(struct sock *sk)
243{
Tom Parkin93606312013-03-19 06:11:15 +0000244 struct l2tp_tunnel *tunnel = l2tp_sock_to_tunnel(sk);
245
Chris Elstona32e0ee2012-04-29 21:48:54 +0000246 lock_sock(sk);
247 ip6_flush_pending_frames(sk);
248 release_sock(sk);
249
Tom Parkin93606312013-03-19 06:11:15 +0000250 if (tunnel) {
251 l2tp_tunnel_closeall(tunnel);
252 sock_put(sk);
253 }
254
Chris Elstona32e0ee2012-04-29 21:48:54 +0000255 inet6_destroy_sock(sk);
256}
257
258static int l2tp_ip6_bind(struct sock *sk, struct sockaddr *uaddr, int addr_len)
259{
260 struct inet_sock *inet = inet_sk(sk);
261 struct ipv6_pinfo *np = inet6_sk(sk);
262 struct sockaddr_l2tpip6 *addr = (struct sockaddr_l2tpip6 *) uaddr;
263 __be32 v4addr = 0;
264 int addr_type;
265 int err;
266
James Chapmanc51ce492012-05-29 03:30:42 +0000267 if (!sock_flag(sk, SOCK_ZAPPED))
268 return -EINVAL;
269 if (addr->l2tp_family != AF_INET6)
270 return -EINVAL;
Chris Elstona32e0ee2012-04-29 21:48:54 +0000271 if (addr_len < sizeof(*addr))
272 return -EINVAL;
273
274 addr_type = ipv6_addr_type(&addr->l2tp_addr);
275
276 /* l2tp_ip6 sockets are IPv6 only */
277 if (addr_type == IPV6_ADDR_MAPPED)
278 return -EADDRNOTAVAIL;
279
280 /* L2TP is point-point, not multicast */
281 if (addr_type & IPV6_ADDR_MULTICAST)
282 return -EADDRNOTAVAIL;
283
284 err = -EADDRINUSE;
285 read_lock_bh(&l2tp_ip6_lock);
286 if (__l2tp_ip6_bind_lookup(&init_net, &addr->l2tp_addr,
287 sk->sk_bound_dev_if, addr->l2tp_conn_id))
288 goto out_in_use;
289 read_unlock_bh(&l2tp_ip6_lock);
290
291 lock_sock(sk);
292
293 err = -EINVAL;
294 if (sk->sk_state != TCP_CLOSE)
295 goto out_unlock;
296
297 /* Check if the address belongs to the host. */
298 rcu_read_lock();
299 if (addr_type != IPV6_ADDR_ANY) {
300 struct net_device *dev = NULL;
301
302 if (addr_type & IPV6_ADDR_LINKLOCAL) {
303 if (addr_len >= sizeof(struct sockaddr_in6) &&
304 addr->l2tp_scope_id) {
305 /* Override any existing binding, if another
306 * one is supplied by user.
307 */
308 sk->sk_bound_dev_if = addr->l2tp_scope_id;
309 }
310
311 /* Binding to link-local address requires an
312 interface */
313 if (!sk->sk_bound_dev_if)
314 goto out_unlock_rcu;
315
316 err = -ENODEV;
317 dev = dev_get_by_index_rcu(sock_net(sk),
318 sk->sk_bound_dev_if);
319 if (!dev)
320 goto out_unlock_rcu;
321 }
322
323 /* ipv4 addr of the socket is invalid. Only the
324 * unspecified and mapped address have a v4 equivalent.
325 */
326 v4addr = LOOPBACK4_IPV6;
327 err = -EADDRNOTAVAIL;
328 if (!ipv6_chk_addr(sock_net(sk), &addr->l2tp_addr, dev, 0))
329 goto out_unlock_rcu;
330 }
331 rcu_read_unlock();
332
333 inet->inet_rcv_saddr = inet->inet_saddr = v4addr;
Eric Dumazetefe42082013-10-03 15:42:29 -0700334 sk->sk_v6_rcv_saddr = addr->l2tp_addr;
Chris Elstona32e0ee2012-04-29 21:48:54 +0000335 np->saddr = addr->l2tp_addr;
336
337 l2tp_ip6_sk(sk)->conn_id = addr->l2tp_conn_id;
338
339 write_lock_bh(&l2tp_ip6_lock);
340 sk_add_bind_node(sk, &l2tp_ip6_bind_table);
341 sk_del_node_init(sk);
342 write_unlock_bh(&l2tp_ip6_lock);
343
James Chapmanc51ce492012-05-29 03:30:42 +0000344 sock_reset_flag(sk, SOCK_ZAPPED);
Chris Elstona32e0ee2012-04-29 21:48:54 +0000345 release_sock(sk);
346 return 0;
347
348out_unlock_rcu:
349 rcu_read_unlock();
350out_unlock:
351 release_sock(sk);
352 return err;
353
354out_in_use:
355 read_unlock_bh(&l2tp_ip6_lock);
356 return err;
357}
358
359static int l2tp_ip6_connect(struct sock *sk, struct sockaddr *uaddr,
360 int addr_len)
361{
362 struct sockaddr_l2tpip6 *lsa = (struct sockaddr_l2tpip6 *) uaddr;
363 struct sockaddr_in6 *usin = (struct sockaddr_in6 *) uaddr;
364 struct in6_addr *daddr;
365 int addr_type;
366 int rc;
367
James Chapmanc51ce492012-05-29 03:30:42 +0000368 if (sock_flag(sk, SOCK_ZAPPED)) /* Must bind first - autobinding does not work */
369 return -EINVAL;
370
Chris Elstona32e0ee2012-04-29 21:48:54 +0000371 if (addr_len < sizeof(*lsa))
372 return -EINVAL;
373
Hannes Frederic Sowa82b276c2014-01-20 05:16:39 +0100374 if (usin->sin6_family != AF_INET6)
375 return -EINVAL;
376
Chris Elstona32e0ee2012-04-29 21:48:54 +0000377 addr_type = ipv6_addr_type(&usin->sin6_addr);
378 if (addr_type & IPV6_ADDR_MULTICAST)
379 return -EINVAL;
380
381 if (addr_type & IPV6_ADDR_MAPPED) {
382 daddr = &usin->sin6_addr;
383 if (ipv4_is_multicast(daddr->s6_addr32[3]))
384 return -EINVAL;
385 }
386
387 rc = ip6_datagram_connect(sk, uaddr, addr_len);
388
389 lock_sock(sk);
390
391 l2tp_ip6_sk(sk)->peer_conn_id = lsa->l2tp_conn_id;
392
393 write_lock_bh(&l2tp_ip6_lock);
394 hlist_del_init(&sk->sk_bind_node);
395 sk_add_bind_node(sk, &l2tp_ip6_bind_table);
396 write_unlock_bh(&l2tp_ip6_lock);
397
398 release_sock(sk);
399
400 return rc;
401}
402
James Chapmanc51ce492012-05-29 03:30:42 +0000403static int l2tp_ip6_disconnect(struct sock *sk, int flags)
404{
405 if (sock_flag(sk, SOCK_ZAPPED))
406 return 0;
407
408 return udp_disconnect(sk, flags);
409}
410
Chris Elstona32e0ee2012-04-29 21:48:54 +0000411static int l2tp_ip6_getname(struct socket *sock, struct sockaddr *uaddr,
412 int *uaddr_len, int peer)
413{
414 struct sockaddr_l2tpip6 *lsa = (struct sockaddr_l2tpip6 *)uaddr;
415 struct sock *sk = sock->sk;
416 struct ipv6_pinfo *np = inet6_sk(sk);
417 struct l2tp_ip6_sock *lsk = l2tp_ip6_sk(sk);
418
419 lsa->l2tp_family = AF_INET6;
420 lsa->l2tp_flowinfo = 0;
421 lsa->l2tp_scope_id = 0;
Mathias Krause04d4fbc2012-08-15 11:31:52 +0000422 lsa->l2tp_unused = 0;
Chris Elstona32e0ee2012-04-29 21:48:54 +0000423 if (peer) {
424 if (!lsk->peer_conn_id)
425 return -ENOTCONN;
426 lsa->l2tp_conn_id = lsk->peer_conn_id;
Eric Dumazetefe42082013-10-03 15:42:29 -0700427 lsa->l2tp_addr = sk->sk_v6_daddr;
Chris Elstona32e0ee2012-04-29 21:48:54 +0000428 if (np->sndflow)
429 lsa->l2tp_flowinfo = np->flow_label;
430 } else {
Eric Dumazetefe42082013-10-03 15:42:29 -0700431 if (ipv6_addr_any(&sk->sk_v6_rcv_saddr))
Chris Elstona32e0ee2012-04-29 21:48:54 +0000432 lsa->l2tp_addr = np->saddr;
433 else
Eric Dumazetefe42082013-10-03 15:42:29 -0700434 lsa->l2tp_addr = sk->sk_v6_rcv_saddr;
Chris Elstona32e0ee2012-04-29 21:48:54 +0000435
436 lsa->l2tp_conn_id = lsk->conn_id;
437 }
438 if (ipv6_addr_type(&lsa->l2tp_addr) & IPV6_ADDR_LINKLOCAL)
439 lsa->l2tp_scope_id = sk->sk_bound_dev_if;
440 *uaddr_len = sizeof(*lsa);
441 return 0;
442}
443
444static int l2tp_ip6_backlog_recv(struct sock *sk, struct sk_buff *skb)
445{
446 int rc;
447
448 /* Charge it to the socket, dropping if the queue is full. */
449 rc = sock_queue_rcv_skb(sk, skb);
450 if (rc < 0)
451 goto drop;
452
453 return 0;
454
455drop:
456 IP_INC_STATS(&init_net, IPSTATS_MIB_INDISCARDS);
457 kfree_skb(skb);
458 return -1;
459}
460
461static int l2tp_ip6_push_pending_frames(struct sock *sk)
462{
463 struct sk_buff *skb;
464 __be32 *transhdr = NULL;
465 int err = 0;
466
467 skb = skb_peek(&sk->sk_write_queue);
468 if (skb == NULL)
469 goto out;
470
471 transhdr = (__be32 *)skb_transport_header(skb);
472 *transhdr = 0;
473
474 err = ip6_push_pending_frames(sk);
475
476out:
477 return err;
478}
479
480/* Userspace will call sendmsg() on the tunnel socket to send L2TP
481 * control frames.
482 */
483static int l2tp_ip6_sendmsg(struct kiocb *iocb, struct sock *sk,
484 struct msghdr *msg, size_t len)
485{
486 struct ipv6_txoptions opt_space;
Steffen Hurrle342dfc32014-01-17 22:53:15 +0100487 DECLARE_SOCKADDR(struct sockaddr_l2tpip6 *, lsa, msg->msg_name);
Chris Elstona32e0ee2012-04-29 21:48:54 +0000488 struct in6_addr *daddr, *final_p, final;
489 struct ipv6_pinfo *np = inet6_sk(sk);
490 struct ipv6_txoptions *opt = NULL;
491 struct ip6_flowlabel *flowlabel = NULL;
492 struct dst_entry *dst = NULL;
493 struct flowi6 fl6;
494 int addr_len = msg->msg_namelen;
495 int hlimit = -1;
496 int tclass = -1;
497 int dontfrag = -1;
498 int transhdrlen = 4; /* zero session-id */
499 int ulen = len + transhdrlen;
500 int err;
501
502 /* Rough check on arithmetic overflow,
503 better check is made in ip6_append_data().
504 */
505 if (len > INT_MAX)
506 return -EMSGSIZE;
507
508 /* Mirror BSD error message compatibility */
509 if (msg->msg_flags & MSG_OOB)
510 return -EOPNOTSUPP;
511
512 /*
513 * Get and verify the address.
514 */
515 memset(&fl6, 0, sizeof(fl6));
516
517 fl6.flowi6_mark = sk->sk_mark;
518
519 if (lsa) {
520 if (addr_len < SIN6_LEN_RFC2133)
521 return -EINVAL;
522
523 if (lsa->l2tp_family && lsa->l2tp_family != AF_INET6)
524 return -EAFNOSUPPORT;
525
526 daddr = &lsa->l2tp_addr;
527 if (np->sndflow) {
528 fl6.flowlabel = lsa->l2tp_flowinfo & IPV6_FLOWINFO_MASK;
529 if (fl6.flowlabel&IPV6_FLOWLABEL_MASK) {
530 flowlabel = fl6_sock_lookup(sk, fl6.flowlabel);
531 if (flowlabel == NULL)
532 return -EINVAL;
Chris Elstona32e0ee2012-04-29 21:48:54 +0000533 }
534 }
535
536 /*
537 * Otherwise it will be difficult to maintain
538 * sk->sk_dst_cache.
539 */
540 if (sk->sk_state == TCP_ESTABLISHED &&
Eric Dumazetefe42082013-10-03 15:42:29 -0700541 ipv6_addr_equal(daddr, &sk->sk_v6_daddr))
542 daddr = &sk->sk_v6_daddr;
Chris Elstona32e0ee2012-04-29 21:48:54 +0000543
544 if (addr_len >= sizeof(struct sockaddr_in6) &&
545 lsa->l2tp_scope_id &&
546 ipv6_addr_type(daddr) & IPV6_ADDR_LINKLOCAL)
547 fl6.flowi6_oif = lsa->l2tp_scope_id;
548 } else {
549 if (sk->sk_state != TCP_ESTABLISHED)
550 return -EDESTADDRREQ;
551
Eric Dumazetefe42082013-10-03 15:42:29 -0700552 daddr = &sk->sk_v6_daddr;
Chris Elstona32e0ee2012-04-29 21:48:54 +0000553 fl6.flowlabel = np->flow_label;
554 }
555
556 if (fl6.flowi6_oif == 0)
557 fl6.flowi6_oif = sk->sk_bound_dev_if;
558
559 if (msg->msg_controllen) {
560 opt = &opt_space;
561 memset(opt, 0, sizeof(struct ipv6_txoptions));
562 opt->tot_len = sizeof(struct ipv6_txoptions);
563
Tom Parkin73df66f2013-01-31 01:02:24 +0000564 err = ip6_datagram_send_ctl(sock_net(sk), sk, msg, &fl6, opt,
565 &hlimit, &tclass, &dontfrag);
Chris Elstona32e0ee2012-04-29 21:48:54 +0000566 if (err < 0) {
567 fl6_sock_release(flowlabel);
568 return err;
569 }
570 if ((fl6.flowlabel & IPV6_FLOWLABEL_MASK) && !flowlabel) {
571 flowlabel = fl6_sock_lookup(sk, fl6.flowlabel);
572 if (flowlabel == NULL)
573 return -EINVAL;
574 }
575 if (!(opt->opt_nflen|opt->opt_flen))
576 opt = NULL;
577 }
578
579 if (opt == NULL)
580 opt = np->opt;
581 if (flowlabel)
582 opt = fl6_merge_options(&opt_space, flowlabel, opt);
583 opt = ipv6_fixup_options(&opt_space, opt);
584
585 fl6.flowi6_proto = sk->sk_protocol;
586 if (!ipv6_addr_any(daddr))
587 fl6.daddr = *daddr;
588 else
589 fl6.daddr.s6_addr[15] = 0x1; /* :: means loopback (BSD'ism) */
590 if (ipv6_addr_any(&fl6.saddr) && !ipv6_addr_any(&np->saddr))
591 fl6.saddr = np->saddr;
592
593 final_p = fl6_update_dst(&fl6, opt, &final);
594
595 if (!fl6.flowi6_oif && ipv6_addr_is_multicast(&fl6.daddr))
596 fl6.flowi6_oif = np->mcast_oif;
597 else if (!fl6.flowi6_oif)
598 fl6.flowi6_oif = np->ucast_oif;
599
600 security_sk_classify_flow(sk, flowi6_to_flowi(&fl6));
601
Steffen Klassert0e0d44a2013-08-28 08:04:14 +0200602 dst = ip6_dst_lookup_flow(sk, &fl6, final_p);
Chris Elstona32e0ee2012-04-29 21:48:54 +0000603 if (IS_ERR(dst)) {
604 err = PTR_ERR(dst);
605 goto out;
606 }
607
Lorenzo Colitti5c986312014-04-29 11:57:34 +0900608 if (hlimit < 0)
609 hlimit = ip6_sk_dst_hoplimit(np, &fl6, dst);
Chris Elstona32e0ee2012-04-29 21:48:54 +0000610
611 if (tclass < 0)
612 tclass = np->tclass;
613
614 if (dontfrag < 0)
615 dontfrag = np->dontfrag;
616
617 if (msg->msg_flags & MSG_CONFIRM)
618 goto do_confirm;
619
620back_from_confirm:
621 lock_sock(sk);
Al Virof69e6d12014-11-24 13:23:40 -0500622 err = ip6_append_data(sk, ip_generic_getfrag, msg,
Chris Elstona32e0ee2012-04-29 21:48:54 +0000623 ulen, transhdrlen, hlimit, tclass, opt,
624 &fl6, (struct rt6_info *)dst,
625 msg->msg_flags, dontfrag);
626 if (err)
627 ip6_flush_pending_frames(sk);
628 else if (!(msg->msg_flags & MSG_MORE))
629 err = l2tp_ip6_push_pending_frames(sk);
630 release_sock(sk);
631done:
632 dst_release(dst);
633out:
634 fl6_sock_release(flowlabel);
635
636 return err < 0 ? err : len;
637
638do_confirm:
639 dst_confirm(dst);
640 if (!(msg->msg_flags & MSG_PROBE) || len)
641 goto back_from_confirm;
642 err = 0;
643 goto done;
644}
645
646static int l2tp_ip6_recvmsg(struct kiocb *iocb, struct sock *sk,
647 struct msghdr *msg, size_t len, int noblock,
648 int flags, int *addr_len)
649{
Tom Parkin700163d2013-01-31 01:02:26 +0000650 struct ipv6_pinfo *np = inet6_sk(sk);
Steffen Hurrle342dfc32014-01-17 22:53:15 +0100651 DECLARE_SOCKADDR(struct sockaddr_l2tpip6 *, lsa, msg->msg_name);
Chris Elstona32e0ee2012-04-29 21:48:54 +0000652 size_t copied = 0;
653 int err = -EOPNOTSUPP;
654 struct sk_buff *skb;
655
656 if (flags & MSG_OOB)
657 goto out;
658
659 if (addr_len)
660 *addr_len = sizeof(*lsa);
661
662 if (flags & MSG_ERRQUEUE)
Hannes Frederic Sowa85fbaa72013-11-23 00:46:12 +0100663 return ipv6_recv_error(sk, msg, len, addr_len);
Chris Elstona32e0ee2012-04-29 21:48:54 +0000664
665 skb = skb_recv_datagram(sk, flags, noblock, &err);
666 if (!skb)
667 goto out;
668
669 copied = skb->len;
670 if (len < copied) {
671 msg->msg_flags |= MSG_TRUNC;
672 copied = len;
673 }
674
David S. Miller51f3d022014-11-05 16:46:40 -0500675 err = skb_copy_datagram_msg(skb, 0, msg, copied);
Chris Elstona32e0ee2012-04-29 21:48:54 +0000676 if (err)
677 goto done;
678
679 sock_recv_timestamp(msg, sk, skb);
680
681 /* Copy the address. */
682 if (lsa) {
683 lsa->l2tp_family = AF_INET6;
684 lsa->l2tp_unused = 0;
685 lsa->l2tp_addr = ipv6_hdr(skb)->saddr;
686 lsa->l2tp_flowinfo = 0;
687 lsa->l2tp_scope_id = 0;
Mathias Krauseb860d3c2013-04-07 01:51:55 +0000688 lsa->l2tp_conn_id = 0;
Chris Elstona32e0ee2012-04-29 21:48:54 +0000689 if (ipv6_addr_type(&lsa->l2tp_addr) & IPV6_ADDR_LINKLOCAL)
Duan Jiong43304872014-08-01 09:52:58 +0800690 lsa->l2tp_scope_id = inet6_iif(skb);
Chris Elstona32e0ee2012-04-29 21:48:54 +0000691 }
692
Tom Parkin700163d2013-01-31 01:02:26 +0000693 if (np->rxopt.all)
694 ip6_datagram_recv_ctl(sk, msg, skb);
Chris Elstona32e0ee2012-04-29 21:48:54 +0000695
696 if (flags & MSG_TRUNC)
697 copied = skb->len;
698done:
699 skb_free_datagram(sk, skb);
700out:
701 return err ? err : copied;
702}
703
704static struct proto l2tp_ip6_prot = {
705 .name = "L2TP/IPv6",
706 .owner = THIS_MODULE,
707 .init = l2tp_ip6_open,
708 .close = l2tp_ip6_close,
709 .bind = l2tp_ip6_bind,
710 .connect = l2tp_ip6_connect,
James Chapmanc51ce492012-05-29 03:30:42 +0000711 .disconnect = l2tp_ip6_disconnect,
Chris Elstona32e0ee2012-04-29 21:48:54 +0000712 .ioctl = udp_ioctl,
713 .destroy = l2tp_ip6_destroy_sock,
714 .setsockopt = ipv6_setsockopt,
715 .getsockopt = ipv6_getsockopt,
716 .sendmsg = l2tp_ip6_sendmsg,
717 .recvmsg = l2tp_ip6_recvmsg,
718 .backlog_rcv = l2tp_ip6_backlog_recv,
719 .hash = inet_hash,
720 .unhash = inet_unhash,
721 .obj_size = sizeof(struct l2tp_ip6_sock),
722#ifdef CONFIG_COMPAT
723 .compat_setsockopt = compat_ipv6_setsockopt,
724 .compat_getsockopt = compat_ipv6_getsockopt,
725#endif
726};
727
728static const struct proto_ops l2tp_ip6_ops = {
729 .family = PF_INET6,
730 .owner = THIS_MODULE,
731 .release = inet6_release,
732 .bind = inet6_bind,
733 .connect = inet_dgram_connect,
734 .socketpair = sock_no_socketpair,
735 .accept = sock_no_accept,
736 .getname = l2tp_ip6_getname,
737 .poll = datagram_poll,
738 .ioctl = inet6_ioctl,
739 .listen = sock_no_listen,
740 .shutdown = inet_shutdown,
741 .setsockopt = sock_common_setsockopt,
742 .getsockopt = sock_common_getsockopt,
743 .sendmsg = inet_sendmsg,
744 .recvmsg = sock_common_recvmsg,
745 .mmap = sock_no_mmap,
746 .sendpage = sock_no_sendpage,
747#ifdef CONFIG_COMPAT
748 .compat_setsockopt = compat_sock_common_setsockopt,
749 .compat_getsockopt = compat_sock_common_getsockopt,
750#endif
751};
752
753static struct inet_protosw l2tp_ip6_protosw = {
754 .type = SOCK_DGRAM,
755 .protocol = IPPROTO_L2TP,
756 .prot = &l2tp_ip6_prot,
757 .ops = &l2tp_ip6_ops,
Chris Elstona32e0ee2012-04-29 21:48:54 +0000758};
759
760static struct inet6_protocol l2tp_ip6_protocol __read_mostly = {
761 .handler = l2tp_ip6_recv,
762};
763
764static int __init l2tp_ip6_init(void)
765{
766 int err;
767
Joe Perchesa4ca44f2012-05-16 09:55:56 +0000768 pr_info("L2TP IP encapsulation support for IPv6 (L2TPv3)\n");
Chris Elstona32e0ee2012-04-29 21:48:54 +0000769
770 err = proto_register(&l2tp_ip6_prot, 1);
771 if (err != 0)
772 goto out;
773
774 err = inet6_add_protocol(&l2tp_ip6_protocol, IPPROTO_L2TP);
775 if (err)
776 goto out1;
777
778 inet6_register_protosw(&l2tp_ip6_protosw);
779 return 0;
780
781out1:
782 proto_unregister(&l2tp_ip6_prot);
783out:
784 return err;
785}
786
787static void __exit l2tp_ip6_exit(void)
788{
789 inet6_unregister_protosw(&l2tp_ip6_protosw);
790 inet6_del_protocol(&l2tp_ip6_protocol, IPPROTO_L2TP);
791 proto_unregister(&l2tp_ip6_prot);
792}
793
794module_init(l2tp_ip6_init);
795module_exit(l2tp_ip6_exit);
796
797MODULE_LICENSE("GPL");
798MODULE_AUTHOR("Chris Elston <celston@katalix.com>");
799MODULE_DESCRIPTION("L2TP IP encapsulation for IPv6");
800MODULE_VERSION("1.0");
801
802/* Use the value of SOCK_DGRAM (2) directory, because __stringify doesn't like
803 * enums
804 */
805MODULE_ALIAS_NET_PF_PROTO_TYPE(PF_INET6, 2, IPPROTO_L2TP);