Commit | Line | Data |
---|---|---|
a32e0eec CE |
1 | /* |
2 | * L2TPv3 IP encapsulation support for IPv6 | |
3 | * | |
4 | * Copyright (c) 2012 Katalix Systems Ltd | |
5 | * | |
6 | * This program is free software; you can redistribute it and/or | |
7 | * modify it under the terms of the GNU General Public License | |
8 | * as published by the Free Software Foundation; either version | |
9 | * 2 of the License, or (at your option) any later version. | |
10 | */ | |
11 | ||
a4ca44fa JP |
12 | #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt |
13 | ||
a32e0eec CE |
14 | #include <linux/icmp.h> |
15 | #include <linux/module.h> | |
16 | #include <linux/skbuff.h> | |
17 | #include <linux/random.h> | |
18 | #include <linux/socket.h> | |
19 | #include <linux/l2tp.h> | |
20 | #include <linux/in.h> | |
21 | #include <linux/in6.h> | |
22 | #include <net/sock.h> | |
23 | #include <net/ip.h> | |
24 | #include <net/icmp.h> | |
25 | #include <net/udp.h> | |
26 | #include <net/inet_common.h> | |
27 | #include <net/inet_hashtables.h> | |
496611d7 | 28 | #include <net/inet6_hashtables.h> |
a32e0eec CE |
29 | #include <net/tcp_states.h> |
30 | #include <net/protocol.h> | |
31 | #include <net/xfrm.h> | |
32 | ||
33 | #include <net/transp_v6.h> | |
34 | #include <net/addrconf.h> | |
35 | #include <net/ip6_route.h> | |
36 | ||
37 | #include "l2tp_core.h" | |
38 | ||
39 | struct l2tp_ip6_sock { | |
40 | /* inet_sock has to be the first member of l2tp_ip6_sock */ | |
41 | struct inet_sock inet; | |
42 | ||
43 | u32 conn_id; | |
44 | u32 peer_conn_id; | |
45 | ||
46 | /* ipv6_pinfo has to be the last member of l2tp_ip6_sock, see | |
47 | inet6_sk_generic */ | |
48 | struct ipv6_pinfo inet6; | |
49 | }; | |
50 | ||
51 | static DEFINE_RWLOCK(l2tp_ip6_lock); | |
52 | static struct hlist_head l2tp_ip6_table; | |
53 | static struct hlist_head l2tp_ip6_bind_table; | |
54 | ||
55 | static inline struct l2tp_ip6_sock *l2tp_ip6_sk(const struct sock *sk) | |
56 | { | |
57 | return (struct l2tp_ip6_sock *)sk; | |
58 | } | |
59 | ||
bb39b0bd GN |
60 | static struct sock *__l2tp_ip6_bind_lookup(const struct net *net, |
61 | const struct in6_addr *laddr, | |
a9b2dff8 | 62 | const struct in6_addr *raddr, |
a32e0eec CE |
63 | int dif, u32 tunnel_id) |
64 | { | |
a32e0eec CE |
65 | struct sock *sk; |
66 | ||
b67bfe0d | 67 | sk_for_each_bound(sk, &l2tp_ip6_bind_table) { |
97b84fd6 | 68 | const struct in6_addr *sk_laddr = inet6_rcv_saddr(sk); |
a9b2dff8 | 69 | const struct in6_addr *sk_raddr = &sk->sk_v6_daddr; |
bb39b0bd | 70 | const struct l2tp_ip6_sock *l2tp = l2tp_ip6_sk(sk); |
a32e0eec | 71 | |
c5fdae04 GN |
72 | if (!net_eq(sock_net(sk), net)) |
73 | continue; | |
74 | ||
75 | if (sk->sk_bound_dev_if && dif && sk->sk_bound_dev_if != dif) | |
76 | continue; | |
77 | ||
78 | if (sk_laddr && !ipv6_addr_any(sk_laddr) && | |
79 | !ipv6_addr_any(laddr) && !ipv6_addr_equal(sk_laddr, laddr)) | |
80 | continue; | |
81 | ||
82 | if (!ipv6_addr_any(sk_raddr) && raddr && | |
83 | !ipv6_addr_any(raddr) && !ipv6_addr_equal(sk_raddr, raddr)) | |
84 | continue; | |
85 | ||
86 | if (l2tp->conn_id != tunnel_id) | |
87 | continue; | |
88 | ||
89 | goto found; | |
a32e0eec CE |
90 | } |
91 | ||
92 | sk = NULL; | |
93 | found: | |
94 | return sk; | |
95 | } | |
96 | ||
a32e0eec CE |
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 | */ | |
130 | static int l2tp_ip6_recv(struct sk_buff *skb) | |
131 | { | |
0e6b5259 | 132 | struct net *net = dev_net(skb->dev); |
a32e0eec CE |
133 | 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; | |
a32e0eec | 140 | |
a32e0eec CE |
141 | if (!pskb_may_pull(skb, 4)) |
142 | goto discard; | |
143 | ||
be447f30 HY |
144 | /* Point to L2TP header */ |
145 | optr = ptr = skb->data; | |
a32e0eec CE |
146 | 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. */ | |
61b9a047 GN |
159 | session = l2tp_session_get(net, NULL, session_id, true); |
160 | if (!session) | |
a32e0eec CE |
161 | goto discard; |
162 | ||
163 | tunnel = session->tunnel; | |
61b9a047 GN |
164 | if (!tunnel) |
165 | goto discard_sess; | |
a32e0eec CE |
166 | |
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)) | |
61b9a047 | 171 | goto discard_sess; |
a32e0eec | 172 | |
be447f30 HY |
173 | /* Point to L2TP header */ |
174 | optr = ptr = skb->data; | |
175 | ptr += 4; | |
a4ca44fa JP |
176 | pr_debug("%s: ip recv\n", tunnel->name); |
177 | print_hex_dump_bytes("", DUMP_PREFIX_OFFSET, ptr, length); | |
a32e0eec CE |
178 | } |
179 | ||
180 | l2tp_recv_common(session, skb, ptr, optr, 0, skb->len, | |
181 | tunnel->recv_payload_hook); | |
61b9a047 GN |
182 | l2tp_session_dec_refcount(session); |
183 | ||
a32e0eec CE |
184 | return 0; |
185 | ||
186 | pass_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]); | |
0e6b5259 | 195 | tunnel = l2tp_tunnel_find(net, tunnel_id); |
94d7ee0b | 196 | if (tunnel) { |
a32e0eec | 197 | sk = tunnel->sock; |
94d7ee0b GN |
198 | sock_hold(sk); |
199 | } else { | |
a32e0eec CE |
200 | struct ipv6hdr *iph = ipv6_hdr(skb); |
201 | ||
202 | read_lock_bh(&l2tp_ip6_lock); | |
a9b2dff8 GN |
203 | sk = __l2tp_ip6_bind_lookup(net, &iph->daddr, &iph->saddr, |
204 | inet6_iif(skb), tunnel_id); | |
a3c18422 GN |
205 | if (!sk) { |
206 | read_unlock_bh(&l2tp_ip6_lock); | |
207 | goto discard; | |
208 | } | |
209 | ||
210 | sock_hold(sk); | |
a32e0eec CE |
211 | read_unlock_bh(&l2tp_ip6_lock); |
212 | } | |
213 | ||
a32e0eec CE |
214 | 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 | ||
61b9a047 GN |
221 | discard_sess: |
222 | if (session->deref) | |
223 | session->deref(session); | |
224 | l2tp_session_dec_refcount(session); | |
225 | goto discard; | |
226 | ||
a32e0eec CE |
227 | discard_put: |
228 | sock_put(sk); | |
229 | ||
230 | discard: | |
231 | kfree_skb(skb); | |
232 | return 0; | |
233 | } | |
234 | ||
235 | static 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 | ||
247 | static 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 | ||
257 | static void l2tp_ip6_destroy_sock(struct sock *sk) | |
258 | { | |
93606317 TP |
259 | struct l2tp_tunnel *tunnel = l2tp_sock_to_tunnel(sk); |
260 | ||
a32e0eec CE |
261 | lock_sock(sk); |
262 | ip6_flush_pending_frames(sk); | |
263 | release_sock(sk); | |
264 | ||
93606317 TP |
265 | if (tunnel) { |
266 | l2tp_tunnel_closeall(tunnel); | |
267 | sock_put(sk); | |
268 | } | |
269 | ||
a32e0eec CE |
270 | inet6_destroy_sock(sk); |
271 | } | |
272 | ||
273 | static 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; | |
0e6b5259 | 278 | struct net *net = sock_net(sk); |
a32e0eec | 279 | __be32 v4addr = 0; |
d5e3a190 | 280 | int bound_dev_if; |
a32e0eec CE |
281 | int addr_type; |
282 | int err; | |
283 | ||
c51ce497 JC |
284 | if (addr->l2tp_family != AF_INET6) |
285 | return -EINVAL; | |
a32e0eec CE |
286 | 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 | ||
a32e0eec CE |
299 | lock_sock(sk); |
300 | ||
301 | err = -EINVAL; | |
32c23116 GN |
302 | if (!sock_flag(sk, SOCK_ZAPPED)) |
303 | goto out_unlock; | |
304 | ||
a32e0eec CE |
305 | if (sk->sk_state != TCP_CLOSE) |
306 | goto out_unlock; | |
307 | ||
d5e3a190 GN |
308 | bound_dev_if = sk->sk_bound_dev_if; |
309 | ||
a32e0eec CE |
310 | /* 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) { | |
d5e3a190 GN |
316 | if (addr->l2tp_scope_id) |
317 | bound_dev_if = addr->l2tp_scope_id; | |
a32e0eec CE |
318 | |
319 | /* Binding to link-local address requires an | |
d5e3a190 GN |
320 | * interface. |
321 | */ | |
322 | if (!bound_dev_if) | |
a32e0eec CE |
323 | goto out_unlock_rcu; |
324 | ||
325 | err = -ENODEV; | |
d5e3a190 | 326 | dev = dev_get_by_index_rcu(sock_net(sk), bound_dev_if); |
a32e0eec CE |
327 | 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 | ||
d5e3a190 | 341 | write_lock_bh(&l2tp_ip6_lock); |
a9b2dff8 | 342 | if (__l2tp_ip6_bind_lookup(net, &addr->l2tp_addr, NULL, bound_dev_if, |
d5e3a190 GN |
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; | |
efe4208f | 352 | sk->sk_v6_rcv_saddr = addr->l2tp_addr; |
a32e0eec CE |
353 | np->saddr = addr->l2tp_addr; |
354 | ||
355 | l2tp_ip6_sk(sk)->conn_id = addr->l2tp_conn_id; | |
356 | ||
a32e0eec CE |
357 | sk_add_bind_node(sk, &l2tp_ip6_bind_table); |
358 | sk_del_node_init(sk); | |
359 | write_unlock_bh(&l2tp_ip6_lock); | |
360 | ||
c51ce497 | 361 | sock_reset_flag(sk, SOCK_ZAPPED); |
a32e0eec CE |
362 | release_sock(sk); |
363 | return 0; | |
364 | ||
365 | out_unlock_rcu: | |
366 | rcu_read_unlock(); | |
367 | out_unlock: | |
368 | release_sock(sk); | |
a32e0eec | 369 | |
a32e0eec CE |
370 | return err; |
371 | } | |
372 | ||
373 | static 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 | ||
82b276cd HFS |
385 | if (usin->sin6_family != AF_INET6) |
386 | return -EINVAL; | |
387 | ||
a32e0eec CE |
388 | 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 | ||
a32e0eec CE |
398 | lock_sock(sk); |
399 | ||
0382a25a GN |
400 | /* 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 | ||
a32e0eec CE |
410 | 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 | ||
0382a25a | 417 | out_sk: |
a32e0eec CE |
418 | release_sock(sk); |
419 | ||
420 | return rc; | |
421 | } | |
422 | ||
c51ce497 JC |
423 | static int l2tp_ip6_disconnect(struct sock *sk, int flags) |
424 | { | |
425 | if (sock_flag(sk, SOCK_ZAPPED)) | |
426 | return 0; | |
427 | ||
286c72de | 428 | return __udp_disconnect(sk, flags); |
c51ce497 JC |
429 | } |
430 | ||
a32e0eec CE |
431 | static 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; | |
04d4fbca | 442 | lsa->l2tp_unused = 0; |
a32e0eec CE |
443 | if (peer) { |
444 | if (!lsk->peer_conn_id) | |
445 | return -ENOTCONN; | |
446 | lsa->l2tp_conn_id = lsk->peer_conn_id; | |
efe4208f | 447 | lsa->l2tp_addr = sk->sk_v6_daddr; |
a32e0eec CE |
448 | if (np->sndflow) |
449 | lsa->l2tp_flowinfo = np->flow_label; | |
450 | } else { | |
efe4208f | 451 | if (ipv6_addr_any(&sk->sk_v6_rcv_saddr)) |
a32e0eec CE |
452 | lsa->l2tp_addr = np->saddr; |
453 | else | |
efe4208f | 454 | lsa->l2tp_addr = sk->sk_v6_rcv_saddr; |
a32e0eec CE |
455 | |
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 | ||
464 | static 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 | ||
475 | drop: | |
0e6b5259 | 476 | IP_INC_STATS(sock_net(sk), IPSTATS_MIB_INDISCARDS); |
a32e0eec CE |
477 | kfree_skb(skb); |
478 | return -1; | |
479 | } | |
480 | ||
481 | static 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 | ||
496 | out: | |
497 | return err; | |
498 | } | |
499 | ||
500 | /* Userspace will call sendmsg() on the tunnel socket to send L2TP | |
501 | * control frames. | |
502 | */ | |
1b784140 | 503 | static int l2tp_ip6_sendmsg(struct sock *sk, struct msghdr *msg, size_t len) |
a32e0eec CE |
504 | { |
505 | struct ipv6_txoptions opt_space; | |
342dfc30 | 506 | DECLARE_SOCKADDR(struct sockaddr_l2tpip6 *, lsa, msg->msg_name); |
a32e0eec CE |
507 | struct in6_addr *daddr, *final_p, final; |
508 | struct ipv6_pinfo *np = inet6_sk(sk); | |
45f6fad8 | 509 | struct ipv6_txoptions *opt_to_free = NULL; |
a32e0eec CE |
510 | struct ipv6_txoptions *opt = NULL; |
511 | struct ip6_flowlabel *flowlabel = NULL; | |
512 | struct dst_entry *dst = NULL; | |
513 | struct flowi6 fl6; | |
ad1e46a8 | 514 | struct sockcm_cookie sockc_unused = {0}; |
26879da5 | 515 | struct ipcm6_cookie ipc6; |
a32e0eec | 516 | int addr_len = msg->msg_namelen; |
a32e0eec CE |
517 | 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; | |
e2d118a1 | 537 | fl6.flowi6_uid = sk->sk_uid; |
a32e0eec | 538 | |
26879da5 WW |
539 | ipc6.hlimit = -1; |
540 | ipc6.tclass = -1; | |
541 | ipc6.dontfrag = -1; | |
542 | ||
a32e0eec CE |
543 | if (lsa) { |
544 | if (addr_len < SIN6_LEN_RFC2133) | |
545 | return -EINVAL; | |
546 | ||
547 | if (lsa->l2tp_family && lsa->l2tp_family != AF_INET6) | |
548 | return -EAFNOSUPPORT; | |
549 | ||
550 | daddr = &lsa->l2tp_addr; | |
551 | if (np->sndflow) { | |
552 | fl6.flowlabel = lsa->l2tp_flowinfo & IPV6_FLOWINFO_MASK; | |
553 | if (fl6.flowlabel&IPV6_FLOWLABEL_MASK) { | |
554 | flowlabel = fl6_sock_lookup(sk, fl6.flowlabel); | |
555 | if (flowlabel == NULL) | |
556 | return -EINVAL; | |
a32e0eec CE |
557 | } |
558 | } | |
559 | ||
560 | /* | |
561 | * Otherwise it will be difficult to maintain | |
562 | * sk->sk_dst_cache. | |
563 | */ | |
564 | if (sk->sk_state == TCP_ESTABLISHED && | |
efe4208f ED |
565 | ipv6_addr_equal(daddr, &sk->sk_v6_daddr)) |
566 | daddr = &sk->sk_v6_daddr; | |
a32e0eec CE |
567 | |
568 | if (addr_len >= sizeof(struct sockaddr_in6) && | |
569 | lsa->l2tp_scope_id && | |
570 | ipv6_addr_type(daddr) & IPV6_ADDR_LINKLOCAL) | |
571 | fl6.flowi6_oif = lsa->l2tp_scope_id; | |
572 | } else { | |
573 | if (sk->sk_state != TCP_ESTABLISHED) | |
574 | return -EDESTADDRREQ; | |
575 | ||
efe4208f | 576 | daddr = &sk->sk_v6_daddr; |
a32e0eec CE |
577 | fl6.flowlabel = np->flow_label; |
578 | } | |
579 | ||
580 | if (fl6.flowi6_oif == 0) | |
581 | fl6.flowi6_oif = sk->sk_bound_dev_if; | |
582 | ||
583 | if (msg->msg_controllen) { | |
584 | opt = &opt_space; | |
585 | memset(opt, 0, sizeof(struct ipv6_txoptions)); | |
586 | opt->tot_len = sizeof(struct ipv6_txoptions); | |
26879da5 | 587 | ipc6.opt = opt; |
a32e0eec | 588 | |
26879da5 WW |
589 | err = ip6_datagram_send_ctl(sock_net(sk), sk, msg, &fl6, &ipc6, |
590 | &sockc_unused); | |
591 | if (err < 0) { | |
a32e0eec CE |
592 | fl6_sock_release(flowlabel); |
593 | return err; | |
594 | } | |
595 | if ((fl6.flowlabel & IPV6_FLOWLABEL_MASK) && !flowlabel) { | |
596 | flowlabel = fl6_sock_lookup(sk, fl6.flowlabel); | |
597 | if (flowlabel == NULL) | |
598 | return -EINVAL; | |
599 | } | |
600 | if (!(opt->opt_nflen|opt->opt_flen)) | |
601 | opt = NULL; | |
602 | } | |
603 | ||
45f6fad8 ED |
604 | if (!opt) { |
605 | opt = txopt_get(np); | |
606 | opt_to_free = opt; | |
607 | } | |
a32e0eec CE |
608 | if (flowlabel) |
609 | opt = fl6_merge_options(&opt_space, flowlabel, opt); | |
610 | opt = ipv6_fixup_options(&opt_space, opt); | |
26879da5 | 611 | ipc6.opt = opt; |
a32e0eec CE |
612 | |
613 | fl6.flowi6_proto = sk->sk_protocol; | |
614 | if (!ipv6_addr_any(daddr)) | |
615 | fl6.daddr = *daddr; | |
616 | else | |
617 | fl6.daddr.s6_addr[15] = 0x1; /* :: means loopback (BSD'ism) */ | |
618 | if (ipv6_addr_any(&fl6.saddr) && !ipv6_addr_any(&np->saddr)) | |
619 | fl6.saddr = np->saddr; | |
620 | ||
621 | final_p = fl6_update_dst(&fl6, opt, &final); | |
622 | ||
623 | if (!fl6.flowi6_oif && ipv6_addr_is_multicast(&fl6.daddr)) | |
624 | fl6.flowi6_oif = np->mcast_oif; | |
625 | else if (!fl6.flowi6_oif) | |
626 | fl6.flowi6_oif = np->ucast_oif; | |
627 | ||
628 | security_sk_classify_flow(sk, flowi6_to_flowi(&fl6)); | |
629 | ||
38b7097b HFS |
630 | if (ipc6.tclass < 0) |
631 | ipc6.tclass = np->tclass; | |
632 | ||
633 | fl6.flowlabel = ip6_make_flowinfo(ipc6.tclass, fl6.flowlabel); | |
634 | ||
0e0d44ab | 635 | dst = ip6_dst_lookup_flow(sk, &fl6, final_p); |
a32e0eec CE |
636 | if (IS_ERR(dst)) { |
637 | err = PTR_ERR(dst); | |
638 | goto out; | |
639 | } | |
640 | ||
26879da5 WW |
641 | if (ipc6.hlimit < 0) |
642 | ipc6.hlimit = ip6_sk_dst_hoplimit(np, &fl6, dst); | |
a32e0eec | 643 | |
26879da5 WW |
644 | if (ipc6.dontfrag < 0) |
645 | ipc6.dontfrag = np->dontfrag; | |
a32e0eec CE |
646 | |
647 | if (msg->msg_flags & MSG_CONFIRM) | |
648 | goto do_confirm; | |
649 | ||
650 | back_from_confirm: | |
651 | lock_sock(sk); | |
f69e6d13 | 652 | err = ip6_append_data(sk, ip_generic_getfrag, msg, |
26879da5 | 653 | ulen, transhdrlen, &ipc6, |
a32e0eec | 654 | &fl6, (struct rt6_info *)dst, |
26879da5 | 655 | msg->msg_flags, &sockc_unused); |
a32e0eec CE |
656 | if (err) |
657 | ip6_flush_pending_frames(sk); | |
658 | else if (!(msg->msg_flags & MSG_MORE)) | |
659 | err = l2tp_ip6_push_pending_frames(sk); | |
660 | release_sock(sk); | |
661 | done: | |
662 | dst_release(dst); | |
663 | out: | |
664 | fl6_sock_release(flowlabel); | |
45f6fad8 | 665 | txopt_put(opt_to_free); |
a32e0eec CE |
666 | |
667 | return err < 0 ? err : len; | |
668 | ||
669 | do_confirm: | |
0dec879f JA |
670 | if (msg->msg_flags & MSG_PROBE) |
671 | dst_confirm_neigh(dst, &fl6.daddr); | |
a32e0eec CE |
672 | if (!(msg->msg_flags & MSG_PROBE) || len) |
673 | goto back_from_confirm; | |
674 | err = 0; | |
675 | goto done; | |
676 | } | |
677 | ||
1b784140 YX |
678 | static int l2tp_ip6_recvmsg(struct sock *sk, struct msghdr *msg, size_t len, |
679 | int noblock, int flags, int *addr_len) | |
a32e0eec | 680 | { |
700163db | 681 | struct ipv6_pinfo *np = inet6_sk(sk); |
342dfc30 | 682 | DECLARE_SOCKADDR(struct sockaddr_l2tpip6 *, lsa, msg->msg_name); |
a32e0eec CE |
683 | size_t copied = 0; |
684 | int err = -EOPNOTSUPP; | |
685 | struct sk_buff *skb; | |
686 | ||
687 | if (flags & MSG_OOB) | |
688 | goto out; | |
689 | ||
690 | if (addr_len) | |
691 | *addr_len = sizeof(*lsa); | |
692 | ||
693 | if (flags & MSG_ERRQUEUE) | |
85fbaa75 | 694 | return ipv6_recv_error(sk, msg, len, addr_len); |
a32e0eec CE |
695 | |
696 | skb = skb_recv_datagram(sk, flags, noblock, &err); | |
697 | if (!skb) | |
698 | goto out; | |
699 | ||
700 | copied = skb->len; | |
701 | if (len < copied) { | |
702 | msg->msg_flags |= MSG_TRUNC; | |
703 | copied = len; | |
704 | } | |
705 | ||
51f3d02b | 706 | err = skb_copy_datagram_msg(skb, 0, msg, copied); |
a32e0eec CE |
707 | if (err) |
708 | goto done; | |
709 | ||
710 | sock_recv_timestamp(msg, sk, skb); | |
711 | ||
712 | /* Copy the address. */ | |
713 | if (lsa) { | |
714 | lsa->l2tp_family = AF_INET6; | |
715 | lsa->l2tp_unused = 0; | |
716 | lsa->l2tp_addr = ipv6_hdr(skb)->saddr; | |
717 | lsa->l2tp_flowinfo = 0; | |
718 | lsa->l2tp_scope_id = 0; | |
b860d3cc | 719 | lsa->l2tp_conn_id = 0; |
a32e0eec | 720 | if (ipv6_addr_type(&lsa->l2tp_addr) & IPV6_ADDR_LINKLOCAL) |
4330487a | 721 | lsa->l2tp_scope_id = inet6_iif(skb); |
a32e0eec CE |
722 | } |
723 | ||
700163db TP |
724 | if (np->rxopt.all) |
725 | ip6_datagram_recv_ctl(sk, msg, skb); | |
a32e0eec CE |
726 | |
727 | if (flags & MSG_TRUNC) | |
728 | copied = skb->len; | |
729 | done: | |
730 | skb_free_datagram(sk, skb); | |
731 | out: | |
732 | return err ? err : copied; | |
733 | } | |
734 | ||
735 | static struct proto l2tp_ip6_prot = { | |
736 | .name = "L2TP/IPv6", | |
737 | .owner = THIS_MODULE, | |
738 | .init = l2tp_ip6_open, | |
739 | .close = l2tp_ip6_close, | |
740 | .bind = l2tp_ip6_bind, | |
741 | .connect = l2tp_ip6_connect, | |
c51ce497 | 742 | .disconnect = l2tp_ip6_disconnect, |
72fb96e7 | 743 | .ioctl = l2tp_ioctl, |
a32e0eec CE |
744 | .destroy = l2tp_ip6_destroy_sock, |
745 | .setsockopt = ipv6_setsockopt, | |
746 | .getsockopt = ipv6_getsockopt, | |
747 | .sendmsg = l2tp_ip6_sendmsg, | |
748 | .recvmsg = l2tp_ip6_recvmsg, | |
749 | .backlog_rcv = l2tp_ip6_backlog_recv, | |
496611d7 | 750 | .hash = inet6_hash, |
a32e0eec CE |
751 | .unhash = inet_unhash, |
752 | .obj_size = sizeof(struct l2tp_ip6_sock), | |
753 | #ifdef CONFIG_COMPAT | |
754 | .compat_setsockopt = compat_ipv6_setsockopt, | |
755 | .compat_getsockopt = compat_ipv6_getsockopt, | |
756 | #endif | |
757 | }; | |
758 | ||
759 | static const struct proto_ops l2tp_ip6_ops = { | |
760 | .family = PF_INET6, | |
761 | .owner = THIS_MODULE, | |
762 | .release = inet6_release, | |
763 | .bind = inet6_bind, | |
764 | .connect = inet_dgram_connect, | |
765 | .socketpair = sock_no_socketpair, | |
766 | .accept = sock_no_accept, | |
767 | .getname = l2tp_ip6_getname, | |
768 | .poll = datagram_poll, | |
769 | .ioctl = inet6_ioctl, | |
770 | .listen = sock_no_listen, | |
771 | .shutdown = inet_shutdown, | |
772 | .setsockopt = sock_common_setsockopt, | |
773 | .getsockopt = sock_common_getsockopt, | |
774 | .sendmsg = inet_sendmsg, | |
775 | .recvmsg = sock_common_recvmsg, | |
776 | .mmap = sock_no_mmap, | |
777 | .sendpage = sock_no_sendpage, | |
778 | #ifdef CONFIG_COMPAT | |
779 | .compat_setsockopt = compat_sock_common_setsockopt, | |
780 | .compat_getsockopt = compat_sock_common_getsockopt, | |
781 | #endif | |
782 | }; | |
783 | ||
784 | static struct inet_protosw l2tp_ip6_protosw = { | |
785 | .type = SOCK_DGRAM, | |
786 | .protocol = IPPROTO_L2TP, | |
787 | .prot = &l2tp_ip6_prot, | |
788 | .ops = &l2tp_ip6_ops, | |
a32e0eec CE |
789 | }; |
790 | ||
791 | static struct inet6_protocol l2tp_ip6_protocol __read_mostly = { | |
792 | .handler = l2tp_ip6_recv, | |
793 | }; | |
794 | ||
795 | static int __init l2tp_ip6_init(void) | |
796 | { | |
797 | int err; | |
798 | ||
a4ca44fa | 799 | pr_info("L2TP IP encapsulation support for IPv6 (L2TPv3)\n"); |
a32e0eec CE |
800 | |
801 | err = proto_register(&l2tp_ip6_prot, 1); | |
802 | if (err != 0) | |
803 | goto out; | |
804 | ||
805 | err = inet6_add_protocol(&l2tp_ip6_protocol, IPPROTO_L2TP); | |
806 | if (err) | |
807 | goto out1; | |
808 | ||
809 | inet6_register_protosw(&l2tp_ip6_protosw); | |
810 | return 0; | |
811 | ||
812 | out1: | |
813 | proto_unregister(&l2tp_ip6_prot); | |
814 | out: | |
815 | return err; | |
816 | } | |
817 | ||
818 | static void __exit l2tp_ip6_exit(void) | |
819 | { | |
820 | inet6_unregister_protosw(&l2tp_ip6_protosw); | |
821 | inet6_del_protocol(&l2tp_ip6_protocol, IPPROTO_L2TP); | |
822 | proto_unregister(&l2tp_ip6_prot); | |
823 | } | |
824 | ||
825 | module_init(l2tp_ip6_init); | |
826 | module_exit(l2tp_ip6_exit); | |
827 | ||
828 | MODULE_LICENSE("GPL"); | |
829 | MODULE_AUTHOR("Chris Elston <celston@katalix.com>"); | |
830 | MODULE_DESCRIPTION("L2TP IP encapsulation for IPv6"); | |
831 | MODULE_VERSION("1.0"); | |
832 | ||
833 | /* Use the value of SOCK_DGRAM (2) directory, because __stringify doesn't like | |
834 | * enums | |
835 | */ | |
836 | MODULE_ALIAS_NET_PF_PROTO_TYPE(PF_INET6, 2, IPPROTO_L2TP); | |
163c2e25 | 837 | MODULE_ALIAS_NET_PF_PROTO(PF_INET6, IPPROTO_L2TP); |