blob: b10abef6b0a03af1261c6e121531fd12e827230c [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>
Craig Gallek496611d2016-02-10 11:50:36 -050028#include <net/inet6_hashtables.h>
Chris Elstona32e0ee2012-04-29 21:48:54 +000029#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{
Chris Elstona32e0ee2012-04-29 21:48:54 +000064 struct sock *sk;
65
Sasha Levinb67bfe02013-02-27 17:06:00 -080066 sk_for_each_bound(sk, &l2tp_ip6_bind_table) {
Eric Dumazetefe42082013-10-03 15:42:29 -070067 const struct in6_addr *addr = inet6_rcv_saddr(sk);
Chris Elstona32e0ee2012-04-29 21:48:54 +000068 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) &&
Guillaume Nault31e2f212016-11-29 13:09:48 +010075 (!addr || ipv6_addr_equal(addr, laddr)) &&
Guillaume Naultdf90e682016-11-29 13:09:47 +010076 (!sk->sk_bound_dev_if || !dif ||
77 sk->sk_bound_dev_if == dif))
Chris Elstona32e0ee2012-04-29 21:48:54 +000078 goto found;
79 }
80
81 sk = NULL;
82found:
83 return sk;
84}
85
86static inline struct sock *l2tp_ip6_bind_lookup(struct net *net,
87 struct in6_addr *laddr,
88 int dif, u32 tunnel_id)
89{
90 struct sock *sk = __l2tp_ip6_bind_lookup(net, laddr, dif, tunnel_id);
91 if (sk)
92 sock_hold(sk);
93
94 return sk;
95}
96
97/* When processing receive frames, there are two cases to
98 * consider. Data frames consist of a non-zero session-id and an
99 * optional cookie. Control frames consist of a regular L2TP header
100 * preceded by 32-bits of zeros.
101 *
102 * L2TPv3 Session Header Over IP
103 *
104 * 0 1 2 3
105 * 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
106 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
107 * | Session ID |
108 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
109 * | Cookie (optional, maximum 64 bits)...
110 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
111 * |
112 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
113 *
114 * L2TPv3 Control Message Header Over IP
115 *
116 * 0 1 2 3
117 * 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
118 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
119 * | (32 bits of zeros) |
120 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
121 * |T|L|x|x|S|x|x|x|x|x|x|x| Ver | Length |
122 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
123 * | Control Connection ID |
124 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
125 * | Ns | Nr |
126 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
127 *
128 * All control frames are passed to userspace.
129 */
130static int l2tp_ip6_recv(struct sk_buff *skb)
131{
Shmulik Ladkani0e6b5252016-05-26 20:16:36 +0300132 struct net *net = dev_net(skb->dev);
Chris Elstona32e0ee2012-04-29 21:48:54 +0000133 struct sock *sk;
134 u32 session_id;
135 u32 tunnel_id;
136 unsigned char *ptr, *optr;
137 struct l2tp_session *session;
138 struct l2tp_tunnel *tunnel = NULL;
139 int length;
Chris Elstona32e0ee2012-04-29 21:48:54 +0000140
Chris Elstona32e0ee2012-04-29 21:48:54 +0000141 if (!pskb_may_pull(skb, 4))
142 goto discard;
143
Haishuang Yanbe447f32016-04-03 22:09:24 +0800144 /* Point to L2TP header */
145 optr = ptr = skb->data;
Chris Elstona32e0ee2012-04-29 21:48:54 +0000146 session_id = ntohl(*((__be32 *) ptr));
147 ptr += 4;
148
149 /* RFC3931: L2TP/IP packets have the first 4 bytes containing
150 * the session_id. If it is 0, the packet is a L2TP control
151 * frame and the session_id value can be discarded.
152 */
153 if (session_id == 0) {
154 __skb_pull(skb, 4);
155 goto pass_up;
156 }
157
158 /* Ok, this is a data packet. Lookup the session. */
Guillaume Nault6539c4f2017-03-31 13:02:25 +0200159 session = l2tp_session_get(net, NULL, session_id, true);
160 if (!session)
Chris Elstona32e0ee2012-04-29 21:48:54 +0000161 goto discard;
162
163 tunnel = session->tunnel;
Guillaume Nault6539c4f2017-03-31 13:02:25 +0200164 if (!tunnel)
165 goto discard_sess;
Chris Elstona32e0ee2012-04-29 21:48:54 +0000166
167 /* Trace packet contents, if enabled */
168 if (tunnel->debug & L2TP_MSG_DATA) {
169 length = min(32u, skb->len);
170 if (!pskb_may_pull(skb, length))
Guillaume Nault6539c4f2017-03-31 13:02:25 +0200171 goto discard_sess;
Chris Elstona32e0ee2012-04-29 21:48:54 +0000172
Haishuang Yanbe447f32016-04-03 22:09:24 +0800173 /* Point to L2TP header */
174 optr = ptr = skb->data;
175 ptr += 4;
Joe Perchesa4ca44f2012-05-16 09:55:56 +0000176 pr_debug("%s: ip recv\n", tunnel->name);
177 print_hex_dump_bytes("", DUMP_PREFIX_OFFSET, ptr, length);
Chris Elstona32e0ee2012-04-29 21:48:54 +0000178 }
179
180 l2tp_recv_common(session, skb, ptr, optr, 0, skb->len,
181 tunnel->recv_payload_hook);
Guillaume Nault6539c4f2017-03-31 13:02:25 +0200182 l2tp_session_dec_refcount(session);
183
Chris Elstona32e0ee2012-04-29 21:48:54 +0000184 return 0;
185
186pass_up:
187 /* Get the tunnel_id from the L2TP header */
188 if (!pskb_may_pull(skb, 12))
189 goto discard;
190
191 if ((skb->data[0] & 0xc0) != 0xc0)
192 goto discard;
193
194 tunnel_id = ntohl(*(__be32 *) &skb->data[4]);
Shmulik Ladkani0e6b5252016-05-26 20:16:36 +0300195 tunnel = l2tp_tunnel_find(net, tunnel_id);
Guillaume Nault59bc4042017-03-29 08:44:59 +0200196 if (tunnel) {
Chris Elstona32e0ee2012-04-29 21:48:54 +0000197 sk = tunnel->sock;
Guillaume Nault59bc4042017-03-29 08:44:59 +0200198 sock_hold(sk);
199 } else {
Chris Elstona32e0ee2012-04-29 21:48:54 +0000200 struct ipv6hdr *iph = ipv6_hdr(skb);
201
202 read_lock_bh(&l2tp_ip6_lock);
Guillaume Naultdf90e682016-11-29 13:09:47 +0100203 sk = __l2tp_ip6_bind_lookup(net, &iph->daddr, inet6_iif(skb),
204 tunnel_id);
Guillaume Naulta3c18422016-11-29 13:09:45 +0100205 if (!sk) {
206 read_unlock_bh(&l2tp_ip6_lock);
207 goto discard;
208 }
209
210 sock_hold(sk);
Chris Elstona32e0ee2012-04-29 21:48:54 +0000211 read_unlock_bh(&l2tp_ip6_lock);
212 }
213
Chris Elstona32e0ee2012-04-29 21:48:54 +0000214 if (!xfrm6_policy_check(sk, XFRM_POLICY_IN, skb))
215 goto discard_put;
216
217 nf_reset(skb);
218
219 return sk_receive_skb(sk, skb, 1);
220
Guillaume Nault6539c4f2017-03-31 13:02:25 +0200221discard_sess:
222 if (session->deref)
223 session->deref(session);
224 l2tp_session_dec_refcount(session);
225 goto discard;
226
Chris Elstona32e0ee2012-04-29 21:48:54 +0000227discard_put:
228 sock_put(sk);
229
230discard:
231 kfree_skb(skb);
232 return 0;
233}
234
235static int l2tp_ip6_open(struct sock *sk)
236{
237 /* Prevent autobind. We don't have ports. */
238 inet_sk(sk)->inet_num = IPPROTO_L2TP;
239
240 write_lock_bh(&l2tp_ip6_lock);
241 sk_add_node(sk, &l2tp_ip6_table);
242 write_unlock_bh(&l2tp_ip6_lock);
243
244 return 0;
245}
246
247static void l2tp_ip6_close(struct sock *sk, long timeout)
248{
249 write_lock_bh(&l2tp_ip6_lock);
250 hlist_del_init(&sk->sk_bind_node);
251 sk_del_node_init(sk);
252 write_unlock_bh(&l2tp_ip6_lock);
253
254 sk_common_release(sk);
255}
256
257static void l2tp_ip6_destroy_sock(struct sock *sk)
258{
Tom Parkin93606312013-03-19 06:11:15 +0000259 struct l2tp_tunnel *tunnel = l2tp_sock_to_tunnel(sk);
260
Chris Elstona32e0ee2012-04-29 21:48:54 +0000261 lock_sock(sk);
262 ip6_flush_pending_frames(sk);
263 release_sock(sk);
264
Tom Parkin93606312013-03-19 06:11:15 +0000265 if (tunnel) {
266 l2tp_tunnel_closeall(tunnel);
267 sock_put(sk);
268 }
269
Chris Elstona32e0ee2012-04-29 21:48:54 +0000270 inet6_destroy_sock(sk);
271}
272
273static int l2tp_ip6_bind(struct sock *sk, struct sockaddr *uaddr, int addr_len)
274{
275 struct inet_sock *inet = inet_sk(sk);
276 struct ipv6_pinfo *np = inet6_sk(sk);
277 struct sockaddr_l2tpip6 *addr = (struct sockaddr_l2tpip6 *) uaddr;
Shmulik Ladkani0e6b5252016-05-26 20:16:36 +0300278 struct net *net = sock_net(sk);
Chris Elstona32e0ee2012-04-29 21:48:54 +0000279 __be32 v4addr = 0;
Guillaume Naultd5e3a192016-11-29 13:09:46 +0100280 int bound_dev_if;
Chris Elstona32e0ee2012-04-29 21:48:54 +0000281 int addr_type;
282 int err;
283
James Chapmanc51ce492012-05-29 03:30:42 +0000284 if (addr->l2tp_family != AF_INET6)
285 return -EINVAL;
Chris Elstona32e0ee2012-04-29 21:48:54 +0000286 if (addr_len < sizeof(*addr))
287 return -EINVAL;
288
289 addr_type = ipv6_addr_type(&addr->l2tp_addr);
290
291 /* l2tp_ip6 sockets are IPv6 only */
292 if (addr_type == IPV6_ADDR_MAPPED)
293 return -EADDRNOTAVAIL;
294
295 /* L2TP is point-point, not multicast */
296 if (addr_type & IPV6_ADDR_MULTICAST)
297 return -EADDRNOTAVAIL;
298
Chris Elstona32e0ee2012-04-29 21:48:54 +0000299 lock_sock(sk);
300
301 err = -EINVAL;
Guillaume Nault32c23112016-11-18 22:13:00 +0100302 if (!sock_flag(sk, SOCK_ZAPPED))
303 goto out_unlock;
304
Chris Elstona32e0ee2012-04-29 21:48:54 +0000305 if (sk->sk_state != TCP_CLOSE)
306 goto out_unlock;
307
Guillaume Naultd5e3a192016-11-29 13:09:46 +0100308 bound_dev_if = sk->sk_bound_dev_if;
309
Chris Elstona32e0ee2012-04-29 21:48:54 +0000310 /* Check if the address belongs to the host. */
311 rcu_read_lock();
312 if (addr_type != IPV6_ADDR_ANY) {
313 struct net_device *dev = NULL;
314
315 if (addr_type & IPV6_ADDR_LINKLOCAL) {
Guillaume Naultd5e3a192016-11-29 13:09:46 +0100316 if (addr->l2tp_scope_id)
317 bound_dev_if = addr->l2tp_scope_id;
Chris Elstona32e0ee2012-04-29 21:48:54 +0000318
319 /* Binding to link-local address requires an
Guillaume Naultd5e3a192016-11-29 13:09:46 +0100320 * interface.
321 */
322 if (!bound_dev_if)
Chris Elstona32e0ee2012-04-29 21:48:54 +0000323 goto out_unlock_rcu;
324
325 err = -ENODEV;
Guillaume Naultd5e3a192016-11-29 13:09:46 +0100326 dev = dev_get_by_index_rcu(sock_net(sk), bound_dev_if);
Chris Elstona32e0ee2012-04-29 21:48:54 +0000327 if (!dev)
328 goto out_unlock_rcu;
329 }
330
331 /* ipv4 addr of the socket is invalid. Only the
332 * unspecified and mapped address have a v4 equivalent.
333 */
334 v4addr = LOOPBACK4_IPV6;
335 err = -EADDRNOTAVAIL;
336 if (!ipv6_chk_addr(sock_net(sk), &addr->l2tp_addr, dev, 0))
337 goto out_unlock_rcu;
338 }
339 rcu_read_unlock();
340
Guillaume Naultd5e3a192016-11-29 13:09:46 +0100341 write_lock_bh(&l2tp_ip6_lock);
342 if (__l2tp_ip6_bind_lookup(net, &addr->l2tp_addr, bound_dev_if,
343 addr->l2tp_conn_id)) {
344 write_unlock_bh(&l2tp_ip6_lock);
345 err = -EADDRINUSE;
346 goto out_unlock;
347 }
348
349 inet->inet_saddr = v4addr;
350 inet->inet_rcv_saddr = v4addr;
351 sk->sk_bound_dev_if = bound_dev_if;
Eric Dumazetefe42082013-10-03 15:42:29 -0700352 sk->sk_v6_rcv_saddr = addr->l2tp_addr;
Chris Elstona32e0ee2012-04-29 21:48:54 +0000353 np->saddr = addr->l2tp_addr;
354
355 l2tp_ip6_sk(sk)->conn_id = addr->l2tp_conn_id;
356
Chris Elstona32e0ee2012-04-29 21:48:54 +0000357 sk_add_bind_node(sk, &l2tp_ip6_bind_table);
358 sk_del_node_init(sk);
359 write_unlock_bh(&l2tp_ip6_lock);
360
James Chapmanc51ce492012-05-29 03:30:42 +0000361 sock_reset_flag(sk, SOCK_ZAPPED);
Chris Elstona32e0ee2012-04-29 21:48:54 +0000362 release_sock(sk);
363 return 0;
364
365out_unlock_rcu:
366 rcu_read_unlock();
367out_unlock:
368 release_sock(sk);
Chris Elstona32e0ee2012-04-29 21:48:54 +0000369
Chris Elstona32e0ee2012-04-29 21:48:54 +0000370 return err;
371}
372
373static int l2tp_ip6_connect(struct sock *sk, struct sockaddr *uaddr,
374 int addr_len)
375{
376 struct sockaddr_l2tpip6 *lsa = (struct sockaddr_l2tpip6 *) uaddr;
377 struct sockaddr_in6 *usin = (struct sockaddr_in6 *) uaddr;
378 struct in6_addr *daddr;
379 int addr_type;
380 int rc;
381
382 if (addr_len < sizeof(*lsa))
383 return -EINVAL;
384
Hannes Frederic Sowa82b276c2014-01-20 05:16:39 +0100385 if (usin->sin6_family != AF_INET6)
386 return -EINVAL;
387
Chris Elstona32e0ee2012-04-29 21:48:54 +0000388 addr_type = ipv6_addr_type(&usin->sin6_addr);
389 if (addr_type & IPV6_ADDR_MULTICAST)
390 return -EINVAL;
391
392 if (addr_type & IPV6_ADDR_MAPPED) {
393 daddr = &usin->sin6_addr;
394 if (ipv4_is_multicast(daddr->s6_addr32[3]))
395 return -EINVAL;
396 }
397
Chris Elstona32e0ee2012-04-29 21:48:54 +0000398 lock_sock(sk);
399
Guillaume Nault0382a252016-11-29 13:09:44 +0100400 /* Must bind first - autobinding does not work */
401 if (sock_flag(sk, SOCK_ZAPPED)) {
402 rc = -EINVAL;
403 goto out_sk;
404 }
405
406 rc = __ip6_datagram_connect(sk, uaddr, addr_len);
407 if (rc < 0)
408 goto out_sk;
409
Chris Elstona32e0ee2012-04-29 21:48:54 +0000410 l2tp_ip6_sk(sk)->peer_conn_id = lsa->l2tp_conn_id;
411
412 write_lock_bh(&l2tp_ip6_lock);
413 hlist_del_init(&sk->sk_bind_node);
414 sk_add_bind_node(sk, &l2tp_ip6_bind_table);
415 write_unlock_bh(&l2tp_ip6_lock);
416
Guillaume Nault0382a252016-11-29 13:09:44 +0100417out_sk:
Chris Elstona32e0ee2012-04-29 21:48:54 +0000418 release_sock(sk);
419
420 return rc;
421}
422
James Chapmanc51ce492012-05-29 03:30:42 +0000423static int l2tp_ip6_disconnect(struct sock *sk, int flags)
424{
425 if (sock_flag(sk, SOCK_ZAPPED))
426 return 0;
427
Eric Dumazet286c72d2016-10-20 09:39:40 -0700428 return __udp_disconnect(sk, flags);
James Chapmanc51ce492012-05-29 03:30:42 +0000429}
430
Chris Elstona32e0ee2012-04-29 21:48:54 +0000431static int l2tp_ip6_getname(struct socket *sock, struct sockaddr *uaddr,
432 int *uaddr_len, int peer)
433{
434 struct sockaddr_l2tpip6 *lsa = (struct sockaddr_l2tpip6 *)uaddr;
435 struct sock *sk = sock->sk;
436 struct ipv6_pinfo *np = inet6_sk(sk);
437 struct l2tp_ip6_sock *lsk = l2tp_ip6_sk(sk);
438
439 lsa->l2tp_family = AF_INET6;
440 lsa->l2tp_flowinfo = 0;
441 lsa->l2tp_scope_id = 0;
Mathias Krause04d4fbc2012-08-15 11:31:52 +0000442 lsa->l2tp_unused = 0;
Chris Elstona32e0ee2012-04-29 21:48:54 +0000443 if (peer) {
444 if (!lsk->peer_conn_id)
445 return -ENOTCONN;
446 lsa->l2tp_conn_id = lsk->peer_conn_id;
Eric Dumazetefe42082013-10-03 15:42:29 -0700447 lsa->l2tp_addr = sk->sk_v6_daddr;
Chris Elstona32e0ee2012-04-29 21:48:54 +0000448 if (np->sndflow)
449 lsa->l2tp_flowinfo = np->flow_label;
450 } else {
Eric Dumazetefe42082013-10-03 15:42:29 -0700451 if (ipv6_addr_any(&sk->sk_v6_rcv_saddr))
Chris Elstona32e0ee2012-04-29 21:48:54 +0000452 lsa->l2tp_addr = np->saddr;
453 else
Eric Dumazetefe42082013-10-03 15:42:29 -0700454 lsa->l2tp_addr = sk->sk_v6_rcv_saddr;
Chris Elstona32e0ee2012-04-29 21:48:54 +0000455
456 lsa->l2tp_conn_id = lsk->conn_id;
457 }
458 if (ipv6_addr_type(&lsa->l2tp_addr) & IPV6_ADDR_LINKLOCAL)
459 lsa->l2tp_scope_id = sk->sk_bound_dev_if;
460 *uaddr_len = sizeof(*lsa);
461 return 0;
462}
463
464static int l2tp_ip6_backlog_recv(struct sock *sk, struct sk_buff *skb)
465{
466 int rc;
467
468 /* Charge it to the socket, dropping if the queue is full. */
469 rc = sock_queue_rcv_skb(sk, skb);
470 if (rc < 0)
471 goto drop;
472
473 return 0;
474
475drop:
Shmulik Ladkani0e6b5252016-05-26 20:16:36 +0300476 IP_INC_STATS(sock_net(sk), IPSTATS_MIB_INDISCARDS);
Chris Elstona32e0ee2012-04-29 21:48:54 +0000477 kfree_skb(skb);
478 return -1;
479}
480
481static int l2tp_ip6_push_pending_frames(struct sock *sk)
482{
483 struct sk_buff *skb;
484 __be32 *transhdr = NULL;
485 int err = 0;
486
487 skb = skb_peek(&sk->sk_write_queue);
488 if (skb == NULL)
489 goto out;
490
491 transhdr = (__be32 *)skb_transport_header(skb);
492 *transhdr = 0;
493
494 err = ip6_push_pending_frames(sk);
495
496out:
497 return err;
498}
499
500/* Userspace will call sendmsg() on the tunnel socket to send L2TP
501 * control frames.
502 */
Ying Xue1b784142015-03-02 15:37:48 +0800503static int l2tp_ip6_sendmsg(struct sock *sk, struct msghdr *msg, size_t len)
Chris Elstona32e0ee2012-04-29 21:48:54 +0000504{
505 struct ipv6_txoptions opt_space;
Steffen Hurrle342dfc32014-01-17 22:53:15 +0100506 DECLARE_SOCKADDR(struct sockaddr_l2tpip6 *, lsa, msg->msg_name);
Chris Elstona32e0ee2012-04-29 21:48:54 +0000507 struct in6_addr *daddr, *final_p, final;
508 struct ipv6_pinfo *np = inet6_sk(sk);
Eric Dumazet45f6fad2015-11-29 19:37:57 -0800509 struct ipv6_txoptions *opt_to_free = NULL;
Chris Elstona32e0ee2012-04-29 21:48:54 +0000510 struct ipv6_txoptions *opt = NULL;
511 struct ip6_flowlabel *flowlabel = NULL;
512 struct dst_entry *dst = NULL;
513 struct flowi6 fl6;
Soheil Hassas Yeganehad1e46a2016-04-02 23:08:11 -0400514 struct sockcm_cookie sockc_unused = {0};
Wei Wang26879da2016-05-02 21:40:07 -0700515 struct ipcm6_cookie ipc6;
Chris Elstona32e0ee2012-04-29 21:48:54 +0000516 int addr_len = msg->msg_namelen;
Chris Elstona32e0ee2012-04-29 21:48:54 +0000517 int transhdrlen = 4; /* zero session-id */
518 int ulen = len + transhdrlen;
519 int err;
520
521 /* Rough check on arithmetic overflow,
522 better check is made in ip6_append_data().
523 */
524 if (len > INT_MAX)
525 return -EMSGSIZE;
526
527 /* Mirror BSD error message compatibility */
528 if (msg->msg_flags & MSG_OOB)
529 return -EOPNOTSUPP;
530
531 /*
532 * Get and verify the address.
533 */
534 memset(&fl6, 0, sizeof(fl6));
535
536 fl6.flowi6_mark = sk->sk_mark;
537
Wei Wang26879da2016-05-02 21:40:07 -0700538 ipc6.hlimit = -1;
539 ipc6.tclass = -1;
540 ipc6.dontfrag = -1;
541
Chris Elstona32e0ee2012-04-29 21:48:54 +0000542 if (lsa) {
543 if (addr_len < SIN6_LEN_RFC2133)
544 return -EINVAL;
545
546 if (lsa->l2tp_family && lsa->l2tp_family != AF_INET6)
547 return -EAFNOSUPPORT;
548
549 daddr = &lsa->l2tp_addr;
550 if (np->sndflow) {
551 fl6.flowlabel = lsa->l2tp_flowinfo & IPV6_FLOWINFO_MASK;
552 if (fl6.flowlabel&IPV6_FLOWLABEL_MASK) {
553 flowlabel = fl6_sock_lookup(sk, fl6.flowlabel);
554 if (flowlabel == NULL)
555 return -EINVAL;
Chris Elstona32e0ee2012-04-29 21:48:54 +0000556 }
557 }
558
559 /*
560 * Otherwise it will be difficult to maintain
561 * sk->sk_dst_cache.
562 */
563 if (sk->sk_state == TCP_ESTABLISHED &&
Eric Dumazetefe42082013-10-03 15:42:29 -0700564 ipv6_addr_equal(daddr, &sk->sk_v6_daddr))
565 daddr = &sk->sk_v6_daddr;
Chris Elstona32e0ee2012-04-29 21:48:54 +0000566
567 if (addr_len >= sizeof(struct sockaddr_in6) &&
568 lsa->l2tp_scope_id &&
569 ipv6_addr_type(daddr) & IPV6_ADDR_LINKLOCAL)
570 fl6.flowi6_oif = lsa->l2tp_scope_id;
571 } else {
572 if (sk->sk_state != TCP_ESTABLISHED)
573 return -EDESTADDRREQ;
574
Eric Dumazetefe42082013-10-03 15:42:29 -0700575 daddr = &sk->sk_v6_daddr;
Chris Elstona32e0ee2012-04-29 21:48:54 +0000576 fl6.flowlabel = np->flow_label;
577 }
578
579 if (fl6.flowi6_oif == 0)
580 fl6.flowi6_oif = sk->sk_bound_dev_if;
581
582 if (msg->msg_controllen) {
583 opt = &opt_space;
584 memset(opt, 0, sizeof(struct ipv6_txoptions));
585 opt->tot_len = sizeof(struct ipv6_txoptions);
Wei Wang26879da2016-05-02 21:40:07 -0700586 ipc6.opt = opt;
Chris Elstona32e0ee2012-04-29 21:48:54 +0000587
Wei Wang26879da2016-05-02 21:40:07 -0700588 err = ip6_datagram_send_ctl(sock_net(sk), sk, msg, &fl6, &ipc6,
589 &sockc_unused);
590 if (err < 0) {
Chris Elstona32e0ee2012-04-29 21:48:54 +0000591 fl6_sock_release(flowlabel);
592 return err;
593 }
594 if ((fl6.flowlabel & IPV6_FLOWLABEL_MASK) && !flowlabel) {
595 flowlabel = fl6_sock_lookup(sk, fl6.flowlabel);
596 if (flowlabel == NULL)
597 return -EINVAL;
598 }
599 if (!(opt->opt_nflen|opt->opt_flen))
600 opt = NULL;
601 }
602
Eric Dumazet45f6fad2015-11-29 19:37:57 -0800603 if (!opt) {
604 opt = txopt_get(np);
605 opt_to_free = opt;
606 }
Chris Elstona32e0ee2012-04-29 21:48:54 +0000607 if (flowlabel)
608 opt = fl6_merge_options(&opt_space, flowlabel, opt);
609 opt = ipv6_fixup_options(&opt_space, opt);
Wei Wang26879da2016-05-02 21:40:07 -0700610 ipc6.opt = opt;
Chris Elstona32e0ee2012-04-29 21:48:54 +0000611
612 fl6.flowi6_proto = sk->sk_protocol;
613 if (!ipv6_addr_any(daddr))
614 fl6.daddr = *daddr;
615 else
616 fl6.daddr.s6_addr[15] = 0x1; /* :: means loopback (BSD'ism) */
617 if (ipv6_addr_any(&fl6.saddr) && !ipv6_addr_any(&np->saddr))
618 fl6.saddr = np->saddr;
619
620 final_p = fl6_update_dst(&fl6, opt, &final);
621
622 if (!fl6.flowi6_oif && ipv6_addr_is_multicast(&fl6.daddr))
623 fl6.flowi6_oif = np->mcast_oif;
624 else if (!fl6.flowi6_oif)
625 fl6.flowi6_oif = np->ucast_oif;
626
627 security_sk_classify_flow(sk, flowi6_to_flowi(&fl6));
628
Hannes Frederic Sowa38b70972016-06-11 20:08:19 +0200629 if (ipc6.tclass < 0)
630 ipc6.tclass = np->tclass;
631
632 fl6.flowlabel = ip6_make_flowinfo(ipc6.tclass, fl6.flowlabel);
633
Steffen Klassert0e0d44a2013-08-28 08:04:14 +0200634 dst = ip6_dst_lookup_flow(sk, &fl6, final_p);
Chris Elstona32e0ee2012-04-29 21:48:54 +0000635 if (IS_ERR(dst)) {
636 err = PTR_ERR(dst);
637 goto out;
638 }
639
Wei Wang26879da2016-05-02 21:40:07 -0700640 if (ipc6.hlimit < 0)
641 ipc6.hlimit = ip6_sk_dst_hoplimit(np, &fl6, dst);
Chris Elstona32e0ee2012-04-29 21:48:54 +0000642
Wei Wang26879da2016-05-02 21:40:07 -0700643 if (ipc6.dontfrag < 0)
644 ipc6.dontfrag = np->dontfrag;
Chris Elstona32e0ee2012-04-29 21:48:54 +0000645
646 if (msg->msg_flags & MSG_CONFIRM)
647 goto do_confirm;
648
649back_from_confirm:
650 lock_sock(sk);
Al Virof69e6d12014-11-24 13:23:40 -0500651 err = ip6_append_data(sk, ip_generic_getfrag, msg,
Wei Wang26879da2016-05-02 21:40:07 -0700652 ulen, transhdrlen, &ipc6,
Chris Elstona32e0ee2012-04-29 21:48:54 +0000653 &fl6, (struct rt6_info *)dst,
Wei Wang26879da2016-05-02 21:40:07 -0700654 msg->msg_flags, &sockc_unused);
Chris Elstona32e0ee2012-04-29 21:48:54 +0000655 if (err)
656 ip6_flush_pending_frames(sk);
657 else if (!(msg->msg_flags & MSG_MORE))
658 err = l2tp_ip6_push_pending_frames(sk);
659 release_sock(sk);
660done:
661 dst_release(dst);
662out:
663 fl6_sock_release(flowlabel);
Eric Dumazet45f6fad2015-11-29 19:37:57 -0800664 txopt_put(opt_to_free);
Chris Elstona32e0ee2012-04-29 21:48:54 +0000665
666 return err < 0 ? err : len;
667
668do_confirm:
669 dst_confirm(dst);
670 if (!(msg->msg_flags & MSG_PROBE) || len)
671 goto back_from_confirm;
672 err = 0;
673 goto done;
674}
675
Ying Xue1b784142015-03-02 15:37:48 +0800676static int l2tp_ip6_recvmsg(struct sock *sk, struct msghdr *msg, size_t len,
677 int noblock, int flags, int *addr_len)
Chris Elstona32e0ee2012-04-29 21:48:54 +0000678{
Tom Parkin700163d2013-01-31 01:02:26 +0000679 struct ipv6_pinfo *np = inet6_sk(sk);
Steffen Hurrle342dfc32014-01-17 22:53:15 +0100680 DECLARE_SOCKADDR(struct sockaddr_l2tpip6 *, lsa, msg->msg_name);
Chris Elstona32e0ee2012-04-29 21:48:54 +0000681 size_t copied = 0;
682 int err = -EOPNOTSUPP;
683 struct sk_buff *skb;
684
685 if (flags & MSG_OOB)
686 goto out;
687
688 if (addr_len)
689 *addr_len = sizeof(*lsa);
690
691 if (flags & MSG_ERRQUEUE)
Hannes Frederic Sowa85fbaa72013-11-23 00:46:12 +0100692 return ipv6_recv_error(sk, msg, len, addr_len);
Chris Elstona32e0ee2012-04-29 21:48:54 +0000693
694 skb = skb_recv_datagram(sk, flags, noblock, &err);
695 if (!skb)
696 goto out;
697
698 copied = skb->len;
699 if (len < copied) {
700 msg->msg_flags |= MSG_TRUNC;
701 copied = len;
702 }
703
David S. Miller51f3d022014-11-05 16:46:40 -0500704 err = skb_copy_datagram_msg(skb, 0, msg, copied);
Chris Elstona32e0ee2012-04-29 21:48:54 +0000705 if (err)
706 goto done;
707
708 sock_recv_timestamp(msg, sk, skb);
709
710 /* Copy the address. */
711 if (lsa) {
712 lsa->l2tp_family = AF_INET6;
713 lsa->l2tp_unused = 0;
714 lsa->l2tp_addr = ipv6_hdr(skb)->saddr;
715 lsa->l2tp_flowinfo = 0;
716 lsa->l2tp_scope_id = 0;
Mathias Krauseb860d3c2013-04-07 01:51:55 +0000717 lsa->l2tp_conn_id = 0;
Chris Elstona32e0ee2012-04-29 21:48:54 +0000718 if (ipv6_addr_type(&lsa->l2tp_addr) & IPV6_ADDR_LINKLOCAL)
Duan Jiong43304872014-08-01 09:52:58 +0800719 lsa->l2tp_scope_id = inet6_iif(skb);
Chris Elstona32e0ee2012-04-29 21:48:54 +0000720 }
721
Tom Parkin700163d2013-01-31 01:02:26 +0000722 if (np->rxopt.all)
723 ip6_datagram_recv_ctl(sk, msg, skb);
Chris Elstona32e0ee2012-04-29 21:48:54 +0000724
725 if (flags & MSG_TRUNC)
726 copied = skb->len;
727done:
728 skb_free_datagram(sk, skb);
729out:
730 return err ? err : copied;
731}
732
733static struct proto l2tp_ip6_prot = {
734 .name = "L2TP/IPv6",
735 .owner = THIS_MODULE,
736 .init = l2tp_ip6_open,
737 .close = l2tp_ip6_close,
738 .bind = l2tp_ip6_bind,
739 .connect = l2tp_ip6_connect,
James Chapmanc51ce492012-05-29 03:30:42 +0000740 .disconnect = l2tp_ip6_disconnect,
Eric Dumazet5b1bb4c2017-02-09 16:15:52 -0800741 .ioctl = l2tp_ioctl,
Chris Elstona32e0ee2012-04-29 21:48:54 +0000742 .destroy = l2tp_ip6_destroy_sock,
743 .setsockopt = ipv6_setsockopt,
744 .getsockopt = ipv6_getsockopt,
745 .sendmsg = l2tp_ip6_sendmsg,
746 .recvmsg = l2tp_ip6_recvmsg,
747 .backlog_rcv = l2tp_ip6_backlog_recv,
Craig Gallek496611d2016-02-10 11:50:36 -0500748 .hash = inet6_hash,
Chris Elstona32e0ee2012-04-29 21:48:54 +0000749 .unhash = inet_unhash,
750 .obj_size = sizeof(struct l2tp_ip6_sock),
751#ifdef CONFIG_COMPAT
752 .compat_setsockopt = compat_ipv6_setsockopt,
753 .compat_getsockopt = compat_ipv6_getsockopt,
754#endif
755};
756
757static const struct proto_ops l2tp_ip6_ops = {
758 .family = PF_INET6,
759 .owner = THIS_MODULE,
760 .release = inet6_release,
761 .bind = inet6_bind,
762 .connect = inet_dgram_connect,
763 .socketpair = sock_no_socketpair,
764 .accept = sock_no_accept,
765 .getname = l2tp_ip6_getname,
766 .poll = datagram_poll,
767 .ioctl = inet6_ioctl,
768 .listen = sock_no_listen,
769 .shutdown = inet_shutdown,
770 .setsockopt = sock_common_setsockopt,
771 .getsockopt = sock_common_getsockopt,
772 .sendmsg = inet_sendmsg,
773 .recvmsg = sock_common_recvmsg,
774 .mmap = sock_no_mmap,
775 .sendpage = sock_no_sendpage,
776#ifdef CONFIG_COMPAT
777 .compat_setsockopt = compat_sock_common_setsockopt,
778 .compat_getsockopt = compat_sock_common_getsockopt,
779#endif
780};
781
782static struct inet_protosw l2tp_ip6_protosw = {
783 .type = SOCK_DGRAM,
784 .protocol = IPPROTO_L2TP,
785 .prot = &l2tp_ip6_prot,
786 .ops = &l2tp_ip6_ops,
Chris Elstona32e0ee2012-04-29 21:48:54 +0000787};
788
789static struct inet6_protocol l2tp_ip6_protocol __read_mostly = {
790 .handler = l2tp_ip6_recv,
791};
792
793static int __init l2tp_ip6_init(void)
794{
795 int err;
796
Joe Perchesa4ca44f2012-05-16 09:55:56 +0000797 pr_info("L2TP IP encapsulation support for IPv6 (L2TPv3)\n");
Chris Elstona32e0ee2012-04-29 21:48:54 +0000798
799 err = proto_register(&l2tp_ip6_prot, 1);
800 if (err != 0)
801 goto out;
802
803 err = inet6_add_protocol(&l2tp_ip6_protocol, IPPROTO_L2TP);
804 if (err)
805 goto out1;
806
807 inet6_register_protosw(&l2tp_ip6_protosw);
808 return 0;
809
810out1:
811 proto_unregister(&l2tp_ip6_prot);
812out:
813 return err;
814}
815
816static void __exit l2tp_ip6_exit(void)
817{
818 inet6_unregister_protosw(&l2tp_ip6_protosw);
819 inet6_del_protocol(&l2tp_ip6_protocol, IPPROTO_L2TP);
820 proto_unregister(&l2tp_ip6_prot);
821}
822
823module_init(l2tp_ip6_init);
824module_exit(l2tp_ip6_exit);
825
826MODULE_LICENSE("GPL");
827MODULE_AUTHOR("Chris Elston <celston@katalix.com>");
828MODULE_DESCRIPTION("L2TP IP encapsulation for IPv6");
829MODULE_VERSION("1.0");
830
831/* Use the value of SOCK_DGRAM (2) directory, because __stringify doesn't like
832 * enums
833 */
834MODULE_ALIAS_NET_PF_PROTO_TYPE(PF_INET6, 2, IPPROTO_L2TP);
stephen hemminger163c2e22015-09-23 21:33:35 -0700835MODULE_ALIAS_NET_PF_PROTO(PF_INET6, IPPROTO_L2TP);