blob: ea2ae6664cc8d643319016ea7a234dc034ec590e [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) &&
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{
Shmulik Ladkani0e6b5252016-05-26 20:16:36 +0300131 struct net *net = dev_net(skb->dev);
Chris Elstona32e0ee2012-04-29 21:48:54 +0000132 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;
Chris Elstona32e0ee2012-04-29 21:48:54 +0000139
Chris Elstona32e0ee2012-04-29 21:48:54 +0000140 if (!pskb_may_pull(skb, 4))
141 goto discard;
142
Haishuang Yanbe447f32016-04-03 22:09:24 +0800143 /* Point to L2TP header */
144 optr = ptr = skb->data;
Chris Elstona32e0ee2012-04-29 21:48:54 +0000145 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. */
Shmulik Ladkani0e6b5252016-05-26 20:16:36 +0300158 session = l2tp_session_find(net, NULL, session_id);
Chris Elstona32e0ee2012-04-29 21:48:54 +0000159 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
Haishuang Yanbe447f32016-04-03 22:09:24 +0800172 /* Point to L2TP header */
173 optr = ptr = skb->data;
174 ptr += 4;
Joe Perchesa4ca44f2012-05-16 09:55:56 +0000175 pr_debug("%s: ip recv\n", tunnel->name);
176 print_hex_dump_bytes("", DUMP_PREFIX_OFFSET, ptr, length);
Chris Elstona32e0ee2012-04-29 21:48:54 +0000177 }
178
179 l2tp_recv_common(session, skb, ptr, optr, 0, skb->len,
180 tunnel->recv_payload_hook);
181 return 0;
182
183pass_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]);
Shmulik Ladkani0e6b5252016-05-26 20:16:36 +0300192 tunnel = l2tp_tunnel_find(net, tunnel_id);
Chris Elstona32e0ee2012-04-29 21:48:54 +0000193 if (tunnel != NULL)
194 sk = tunnel->sock;
195 else {
196 struct ipv6hdr *iph = ipv6_hdr(skb);
197
198 read_lock_bh(&l2tp_ip6_lock);
Shmulik Ladkani0e6b5252016-05-26 20:16:36 +0300199 sk = __l2tp_ip6_bind_lookup(net, &iph->daddr,
Chris Elstona32e0ee2012-04-29 21:48:54 +0000200 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
216discard_put:
217 sock_put(sk);
218
219discard:
220 kfree_skb(skb);
221 return 0;
222}
223
224static 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
236static 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
246static void l2tp_ip6_destroy_sock(struct sock *sk)
247{
Tom Parkin93606312013-03-19 06:11:15 +0000248 struct l2tp_tunnel *tunnel = l2tp_sock_to_tunnel(sk);
249
Chris Elstona32e0ee2012-04-29 21:48:54 +0000250 lock_sock(sk);
251 ip6_flush_pending_frames(sk);
252 release_sock(sk);
253
Tom Parkin93606312013-03-19 06:11:15 +0000254 if (tunnel) {
255 l2tp_tunnel_closeall(tunnel);
256 sock_put(sk);
257 }
258
Chris Elstona32e0ee2012-04-29 21:48:54 +0000259 inet6_destroy_sock(sk);
260}
261
262static 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;
Shmulik Ladkani0e6b5252016-05-26 20:16:36 +0300267 struct net *net = sock_net(sk);
Chris Elstona32e0ee2012-04-29 21:48:54 +0000268 __be32 v4addr = 0;
269 int addr_type;
270 int err;
271
James Chapmanc51ce492012-05-29 03:30:42 +0000272 if (!sock_flag(sk, SOCK_ZAPPED))
273 return -EINVAL;
274 if (addr->l2tp_family != AF_INET6)
275 return -EINVAL;
Chris Elstona32e0ee2012-04-29 21:48:54 +0000276 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);
Shmulik Ladkani0e6b5252016-05-26 20:16:36 +0300291 if (__l2tp_ip6_bind_lookup(net, &addr->l2tp_addr,
Chris Elstona32e0ee2012-04-29 21:48:54 +0000292 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;
Eric Dumazetefe42082013-10-03 15:42:29 -0700339 sk->sk_v6_rcv_saddr = addr->l2tp_addr;
Chris Elstona32e0ee2012-04-29 21:48:54 +0000340 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
James Chapmanc51ce492012-05-29 03:30:42 +0000349 sock_reset_flag(sk, SOCK_ZAPPED);
Chris Elstona32e0ee2012-04-29 21:48:54 +0000350 release_sock(sk);
351 return 0;
352
353out_unlock_rcu:
354 rcu_read_unlock();
355out_unlock:
356 release_sock(sk);
357 return err;
358
359out_in_use:
360 read_unlock_bh(&l2tp_ip6_lock);
361 return err;
362}
363
364static 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
James Chapmanc51ce492012-05-29 03:30:42 +0000373 if (sock_flag(sk, SOCK_ZAPPED)) /* Must bind first - autobinding does not work */
374 return -EINVAL;
375
Chris Elstona32e0ee2012-04-29 21:48:54 +0000376 if (addr_len < sizeof(*lsa))
377 return -EINVAL;
378
Hannes Frederic Sowa82b276c2014-01-20 05:16:39 +0100379 if (usin->sin6_family != AF_INET6)
380 return -EINVAL;
381
Chris Elstona32e0ee2012-04-29 21:48:54 +0000382 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
James Chapmanc51ce492012-05-29 03:30:42 +0000408static 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
Chris Elstona32e0ee2012-04-29 21:48:54 +0000416static 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;
Mathias Krause04d4fbc2012-08-15 11:31:52 +0000427 lsa->l2tp_unused = 0;
Chris Elstona32e0ee2012-04-29 21:48:54 +0000428 if (peer) {
429 if (!lsk->peer_conn_id)
430 return -ENOTCONN;
431 lsa->l2tp_conn_id = lsk->peer_conn_id;
Eric Dumazetefe42082013-10-03 15:42:29 -0700432 lsa->l2tp_addr = sk->sk_v6_daddr;
Chris Elstona32e0ee2012-04-29 21:48:54 +0000433 if (np->sndflow)
434 lsa->l2tp_flowinfo = np->flow_label;
435 } else {
Eric Dumazetefe42082013-10-03 15:42:29 -0700436 if (ipv6_addr_any(&sk->sk_v6_rcv_saddr))
Chris Elstona32e0ee2012-04-29 21:48:54 +0000437 lsa->l2tp_addr = np->saddr;
438 else
Eric Dumazetefe42082013-10-03 15:42:29 -0700439 lsa->l2tp_addr = sk->sk_v6_rcv_saddr;
Chris Elstona32e0ee2012-04-29 21:48:54 +0000440
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
449static 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
460drop:
Shmulik Ladkani0e6b5252016-05-26 20:16:36 +0300461 IP_INC_STATS(sock_net(sk), IPSTATS_MIB_INDISCARDS);
Chris Elstona32e0ee2012-04-29 21:48:54 +0000462 kfree_skb(skb);
463 return -1;
464}
465
466static 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
481out:
482 return err;
483}
484
485/* Userspace will call sendmsg() on the tunnel socket to send L2TP
486 * control frames.
487 */
Ying Xue1b784142015-03-02 15:37:48 +0800488static int l2tp_ip6_sendmsg(struct sock *sk, struct msghdr *msg, size_t len)
Chris Elstona32e0ee2012-04-29 21:48:54 +0000489{
490 struct ipv6_txoptions opt_space;
Steffen Hurrle342dfc32014-01-17 22:53:15 +0100491 DECLARE_SOCKADDR(struct sockaddr_l2tpip6 *, lsa, msg->msg_name);
Chris Elstona32e0ee2012-04-29 21:48:54 +0000492 struct in6_addr *daddr, *final_p, final;
493 struct ipv6_pinfo *np = inet6_sk(sk);
Eric Dumazet45f6fad2015-11-29 19:37:57 -0800494 struct ipv6_txoptions *opt_to_free = NULL;
Chris Elstona32e0ee2012-04-29 21:48:54 +0000495 struct ipv6_txoptions *opt = NULL;
496 struct ip6_flowlabel *flowlabel = NULL;
497 struct dst_entry *dst = NULL;
498 struct flowi6 fl6;
Soheil Hassas Yeganehad1e46a2016-04-02 23:08:11 -0400499 struct sockcm_cookie sockc_unused = {0};
Wei Wang26879da2016-05-02 21:40:07 -0700500 struct ipcm6_cookie ipc6;
Chris Elstona32e0ee2012-04-29 21:48:54 +0000501 int addr_len = msg->msg_namelen;
Chris Elstona32e0ee2012-04-29 21:48:54 +0000502 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
Wei Wang26879da2016-05-02 21:40:07 -0700523 ipc6.hlimit = -1;
524 ipc6.tclass = -1;
525 ipc6.dontfrag = -1;
526
Chris Elstona32e0ee2012-04-29 21:48:54 +0000527 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;
Chris Elstona32e0ee2012-04-29 21:48:54 +0000541 }
542 }
543
544 /*
545 * Otherwise it will be difficult to maintain
546 * sk->sk_dst_cache.
547 */
548 if (sk->sk_state == TCP_ESTABLISHED &&
Eric Dumazetefe42082013-10-03 15:42:29 -0700549 ipv6_addr_equal(daddr, &sk->sk_v6_daddr))
550 daddr = &sk->sk_v6_daddr;
Chris Elstona32e0ee2012-04-29 21:48:54 +0000551
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
Eric Dumazetefe42082013-10-03 15:42:29 -0700560 daddr = &sk->sk_v6_daddr;
Chris Elstona32e0ee2012-04-29 21:48:54 +0000561 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);
Wei Wang26879da2016-05-02 21:40:07 -0700571 ipc6.opt = opt;
Chris Elstona32e0ee2012-04-29 21:48:54 +0000572
Wei Wang26879da2016-05-02 21:40:07 -0700573 err = ip6_datagram_send_ctl(sock_net(sk), sk, msg, &fl6, &ipc6,
574 &sockc_unused);
575 if (err < 0) {
Chris Elstona32e0ee2012-04-29 21:48:54 +0000576 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
Eric Dumazet45f6fad2015-11-29 19:37:57 -0800588 if (!opt) {
589 opt = txopt_get(np);
590 opt_to_free = opt;
591 }
Chris Elstona32e0ee2012-04-29 21:48:54 +0000592 if (flowlabel)
593 opt = fl6_merge_options(&opt_space, flowlabel, opt);
594 opt = ipv6_fixup_options(&opt_space, opt);
Wei Wang26879da2016-05-02 21:40:07 -0700595 ipc6.opt = opt;
Chris Elstona32e0ee2012-04-29 21:48:54 +0000596
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
Hannes Frederic Sowa38b70972016-06-11 20:08:19 +0200614 if (ipc6.tclass < 0)
615 ipc6.tclass = np->tclass;
616
617 fl6.flowlabel = ip6_make_flowinfo(ipc6.tclass, fl6.flowlabel);
618
Steffen Klassert0e0d44a2013-08-28 08:04:14 +0200619 dst = ip6_dst_lookup_flow(sk, &fl6, final_p);
Chris Elstona32e0ee2012-04-29 21:48:54 +0000620 if (IS_ERR(dst)) {
621 err = PTR_ERR(dst);
622 goto out;
623 }
624
Wei Wang26879da2016-05-02 21:40:07 -0700625 if (ipc6.hlimit < 0)
626 ipc6.hlimit = ip6_sk_dst_hoplimit(np, &fl6, dst);
Chris Elstona32e0ee2012-04-29 21:48:54 +0000627
Wei Wang26879da2016-05-02 21:40:07 -0700628 if (ipc6.dontfrag < 0)
629 ipc6.dontfrag = np->dontfrag;
Chris Elstona32e0ee2012-04-29 21:48:54 +0000630
631 if (msg->msg_flags & MSG_CONFIRM)
632 goto do_confirm;
633
634back_from_confirm:
635 lock_sock(sk);
Al Virof69e6d12014-11-24 13:23:40 -0500636 err = ip6_append_data(sk, ip_generic_getfrag, msg,
Wei Wang26879da2016-05-02 21:40:07 -0700637 ulen, transhdrlen, &ipc6,
Chris Elstona32e0ee2012-04-29 21:48:54 +0000638 &fl6, (struct rt6_info *)dst,
Wei Wang26879da2016-05-02 21:40:07 -0700639 msg->msg_flags, &sockc_unused);
Chris Elstona32e0ee2012-04-29 21:48:54 +0000640 if (err)
641 ip6_flush_pending_frames(sk);
642 else if (!(msg->msg_flags & MSG_MORE))
643 err = l2tp_ip6_push_pending_frames(sk);
644 release_sock(sk);
645done:
646 dst_release(dst);
647out:
648 fl6_sock_release(flowlabel);
Eric Dumazet45f6fad2015-11-29 19:37:57 -0800649 txopt_put(opt_to_free);
Chris Elstona32e0ee2012-04-29 21:48:54 +0000650
651 return err < 0 ? err : len;
652
653do_confirm:
654 dst_confirm(dst);
655 if (!(msg->msg_flags & MSG_PROBE) || len)
656 goto back_from_confirm;
657 err = 0;
658 goto done;
659}
660
Ying Xue1b784142015-03-02 15:37:48 +0800661static int l2tp_ip6_recvmsg(struct sock *sk, struct msghdr *msg, size_t len,
662 int noblock, int flags, int *addr_len)
Chris Elstona32e0ee2012-04-29 21:48:54 +0000663{
Tom Parkin700163d2013-01-31 01:02:26 +0000664 struct ipv6_pinfo *np = inet6_sk(sk);
Steffen Hurrle342dfc32014-01-17 22:53:15 +0100665 DECLARE_SOCKADDR(struct sockaddr_l2tpip6 *, lsa, msg->msg_name);
Chris Elstona32e0ee2012-04-29 21:48:54 +0000666 size_t copied = 0;
667 int err = -EOPNOTSUPP;
668 struct sk_buff *skb;
669
670 if (flags & MSG_OOB)
671 goto out;
672
673 if (addr_len)
674 *addr_len = sizeof(*lsa);
675
676 if (flags & MSG_ERRQUEUE)
Hannes Frederic Sowa85fbaa72013-11-23 00:46:12 +0100677 return ipv6_recv_error(sk, msg, len, addr_len);
Chris Elstona32e0ee2012-04-29 21:48:54 +0000678
679 skb = skb_recv_datagram(sk, flags, noblock, &err);
680 if (!skb)
681 goto out;
682
683 copied = skb->len;
684 if (len < copied) {
685 msg->msg_flags |= MSG_TRUNC;
686 copied = len;
687 }
688
David S. Miller51f3d022014-11-05 16:46:40 -0500689 err = skb_copy_datagram_msg(skb, 0, msg, copied);
Chris Elstona32e0ee2012-04-29 21:48:54 +0000690 if (err)
691 goto done;
692
693 sock_recv_timestamp(msg, sk, skb);
694
695 /* Copy the address. */
696 if (lsa) {
697 lsa->l2tp_family = AF_INET6;
698 lsa->l2tp_unused = 0;
699 lsa->l2tp_addr = ipv6_hdr(skb)->saddr;
700 lsa->l2tp_flowinfo = 0;
701 lsa->l2tp_scope_id = 0;
Mathias Krauseb860d3c2013-04-07 01:51:55 +0000702 lsa->l2tp_conn_id = 0;
Chris Elstona32e0ee2012-04-29 21:48:54 +0000703 if (ipv6_addr_type(&lsa->l2tp_addr) & IPV6_ADDR_LINKLOCAL)
Duan Jiong43304872014-08-01 09:52:58 +0800704 lsa->l2tp_scope_id = inet6_iif(skb);
Chris Elstona32e0ee2012-04-29 21:48:54 +0000705 }
706
Tom Parkin700163d2013-01-31 01:02:26 +0000707 if (np->rxopt.all)
708 ip6_datagram_recv_ctl(sk, msg, skb);
Chris Elstona32e0ee2012-04-29 21:48:54 +0000709
710 if (flags & MSG_TRUNC)
711 copied = skb->len;
712done:
713 skb_free_datagram(sk, skb);
714out:
715 return err ? err : copied;
716}
717
718static struct proto l2tp_ip6_prot = {
719 .name = "L2TP/IPv6",
720 .owner = THIS_MODULE,
721 .init = l2tp_ip6_open,
722 .close = l2tp_ip6_close,
723 .bind = l2tp_ip6_bind,
724 .connect = l2tp_ip6_connect,
James Chapmanc51ce492012-05-29 03:30:42 +0000725 .disconnect = l2tp_ip6_disconnect,
Chris Elstona32e0ee2012-04-29 21:48:54 +0000726 .ioctl = udp_ioctl,
727 .destroy = l2tp_ip6_destroy_sock,
728 .setsockopt = ipv6_setsockopt,
729 .getsockopt = ipv6_getsockopt,
730 .sendmsg = l2tp_ip6_sendmsg,
731 .recvmsg = l2tp_ip6_recvmsg,
732 .backlog_rcv = l2tp_ip6_backlog_recv,
Craig Gallek496611d2016-02-10 11:50:36 -0500733 .hash = inet6_hash,
Chris Elstona32e0ee2012-04-29 21:48:54 +0000734 .unhash = inet_unhash,
735 .obj_size = sizeof(struct l2tp_ip6_sock),
736#ifdef CONFIG_COMPAT
737 .compat_setsockopt = compat_ipv6_setsockopt,
738 .compat_getsockopt = compat_ipv6_getsockopt,
739#endif
740};
741
742static const struct proto_ops l2tp_ip6_ops = {
743 .family = PF_INET6,
744 .owner = THIS_MODULE,
745 .release = inet6_release,
746 .bind = inet6_bind,
747 .connect = inet_dgram_connect,
748 .socketpair = sock_no_socketpair,
749 .accept = sock_no_accept,
750 .getname = l2tp_ip6_getname,
751 .poll = datagram_poll,
752 .ioctl = inet6_ioctl,
753 .listen = sock_no_listen,
754 .shutdown = inet_shutdown,
755 .setsockopt = sock_common_setsockopt,
756 .getsockopt = sock_common_getsockopt,
757 .sendmsg = inet_sendmsg,
758 .recvmsg = sock_common_recvmsg,
759 .mmap = sock_no_mmap,
760 .sendpage = sock_no_sendpage,
761#ifdef CONFIG_COMPAT
762 .compat_setsockopt = compat_sock_common_setsockopt,
763 .compat_getsockopt = compat_sock_common_getsockopt,
764#endif
765};
766
767static struct inet_protosw l2tp_ip6_protosw = {
768 .type = SOCK_DGRAM,
769 .protocol = IPPROTO_L2TP,
770 .prot = &l2tp_ip6_prot,
771 .ops = &l2tp_ip6_ops,
Chris Elstona32e0ee2012-04-29 21:48:54 +0000772};
773
774static struct inet6_protocol l2tp_ip6_protocol __read_mostly = {
775 .handler = l2tp_ip6_recv,
776};
777
778static int __init l2tp_ip6_init(void)
779{
780 int err;
781
Joe Perchesa4ca44f2012-05-16 09:55:56 +0000782 pr_info("L2TP IP encapsulation support for IPv6 (L2TPv3)\n");
Chris Elstona32e0ee2012-04-29 21:48:54 +0000783
784 err = proto_register(&l2tp_ip6_prot, 1);
785 if (err != 0)
786 goto out;
787
788 err = inet6_add_protocol(&l2tp_ip6_protocol, IPPROTO_L2TP);
789 if (err)
790 goto out1;
791
792 inet6_register_protosw(&l2tp_ip6_protosw);
793 return 0;
794
795out1:
796 proto_unregister(&l2tp_ip6_prot);
797out:
798 return err;
799}
800
801static void __exit l2tp_ip6_exit(void)
802{
803 inet6_unregister_protosw(&l2tp_ip6_protosw);
804 inet6_del_protocol(&l2tp_ip6_protocol, IPPROTO_L2TP);
805 proto_unregister(&l2tp_ip6_prot);
806}
807
808module_init(l2tp_ip6_init);
809module_exit(l2tp_ip6_exit);
810
811MODULE_LICENSE("GPL");
812MODULE_AUTHOR("Chris Elston <celston@katalix.com>");
813MODULE_DESCRIPTION("L2TP IP encapsulation for IPv6");
814MODULE_VERSION("1.0");
815
816/* Use the value of SOCK_DGRAM (2) directory, because __stringify doesn't like
817 * enums
818 */
819MODULE_ALIAS_NET_PF_PROTO_TYPE(PF_INET6, 2, IPPROTO_L2TP);
stephen hemminger163c2e22015-09-23 21:33:35 -0700820MODULE_ALIAS_NET_PF_PROTO(PF_INET6, IPPROTO_L2TP);