]>
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. */ | |
0e6b5259 | 159 | session = l2tp_session_find(net, NULL, session_id); |
a32e0eec CE |
160 | if (session == NULL) |
161 | goto discard; | |
162 | ||
163 | tunnel = session->tunnel; | |
164 | if (tunnel == NULL) | |
165 | goto discard; | |
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)) | |
171 | goto discard; | |
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); | |
182 | return 0; | |
183 | ||
184 | pass_up: | |
185 | /* Get the tunnel_id from the L2TP header */ | |
186 | if (!pskb_may_pull(skb, 12)) | |
187 | goto discard; | |
188 | ||
189 | if ((skb->data[0] & 0xc0) != 0xc0) | |
190 | goto discard; | |
191 | ||
192 | tunnel_id = ntohl(*(__be32 *) &skb->data[4]); | |
0e6b5259 | 193 | tunnel = l2tp_tunnel_find(net, tunnel_id); |
94d7ee0b | 194 | if (tunnel) { |
a32e0eec | 195 | sk = tunnel->sock; |
94d7ee0b GN |
196 | sock_hold(sk); |
197 | } else { | |
a32e0eec CE |
198 | struct ipv6hdr *iph = ipv6_hdr(skb); |
199 | ||
200 | read_lock_bh(&l2tp_ip6_lock); | |
a9b2dff8 GN |
201 | sk = __l2tp_ip6_bind_lookup(net, &iph->daddr, &iph->saddr, |
202 | inet6_iif(skb), tunnel_id); | |
a3c18422 GN |
203 | if (!sk) { |
204 | read_unlock_bh(&l2tp_ip6_lock); | |
205 | goto discard; | |
206 | } | |
207 | ||
208 | sock_hold(sk); | |
a32e0eec CE |
209 | read_unlock_bh(&l2tp_ip6_lock); |
210 | } | |
211 | ||
a32e0eec CE |
212 | if (!xfrm6_policy_check(sk, XFRM_POLICY_IN, skb)) |
213 | goto discard_put; | |
214 | ||
215 | nf_reset(skb); | |
216 | ||
217 | return sk_receive_skb(sk, skb, 1); | |
218 | ||
219 | discard_put: | |
220 | sock_put(sk); | |
221 | ||
222 | discard: | |
223 | kfree_skb(skb); | |
224 | return 0; | |
225 | } | |
226 | ||
227 | static int l2tp_ip6_open(struct sock *sk) | |
228 | { | |
229 | /* Prevent autobind. We don't have ports. */ | |
230 | inet_sk(sk)->inet_num = IPPROTO_L2TP; | |
231 | ||
232 | write_lock_bh(&l2tp_ip6_lock); | |
233 | sk_add_node(sk, &l2tp_ip6_table); | |
234 | write_unlock_bh(&l2tp_ip6_lock); | |
235 | ||
236 | return 0; | |
237 | } | |
238 | ||
239 | static void l2tp_ip6_close(struct sock *sk, long timeout) | |
240 | { | |
241 | write_lock_bh(&l2tp_ip6_lock); | |
242 | hlist_del_init(&sk->sk_bind_node); | |
243 | sk_del_node_init(sk); | |
244 | write_unlock_bh(&l2tp_ip6_lock); | |
245 | ||
246 | sk_common_release(sk); | |
247 | } | |
248 | ||
249 | static void l2tp_ip6_destroy_sock(struct sock *sk) | |
250 | { | |
93606317 TP |
251 | struct l2tp_tunnel *tunnel = l2tp_sock_to_tunnel(sk); |
252 | ||
a32e0eec CE |
253 | lock_sock(sk); |
254 | ip6_flush_pending_frames(sk); | |
255 | release_sock(sk); | |
256 | ||
93606317 TP |
257 | if (tunnel) { |
258 | l2tp_tunnel_closeall(tunnel); | |
259 | sock_put(sk); | |
260 | } | |
261 | ||
a32e0eec CE |
262 | inet6_destroy_sock(sk); |
263 | } | |
264 | ||
265 | static int l2tp_ip6_bind(struct sock *sk, struct sockaddr *uaddr, int addr_len) | |
266 | { | |
267 | struct inet_sock *inet = inet_sk(sk); | |
268 | struct ipv6_pinfo *np = inet6_sk(sk); | |
269 | struct sockaddr_l2tpip6 *addr = (struct sockaddr_l2tpip6 *) uaddr; | |
0e6b5259 | 270 | struct net *net = sock_net(sk); |
a32e0eec | 271 | __be32 v4addr = 0; |
d5e3a190 | 272 | int bound_dev_if; |
a32e0eec CE |
273 | int addr_type; |
274 | int err; | |
275 | ||
c51ce497 JC |
276 | if (addr->l2tp_family != AF_INET6) |
277 | return -EINVAL; | |
a32e0eec CE |
278 | if (addr_len < sizeof(*addr)) |
279 | return -EINVAL; | |
280 | ||
281 | addr_type = ipv6_addr_type(&addr->l2tp_addr); | |
282 | ||
283 | /* l2tp_ip6 sockets are IPv6 only */ | |
284 | if (addr_type == IPV6_ADDR_MAPPED) | |
285 | return -EADDRNOTAVAIL; | |
286 | ||
287 | /* L2TP is point-point, not multicast */ | |
288 | if (addr_type & IPV6_ADDR_MULTICAST) | |
289 | return -EADDRNOTAVAIL; | |
290 | ||
a32e0eec CE |
291 | lock_sock(sk); |
292 | ||
293 | err = -EINVAL; | |
32c23116 GN |
294 | if (!sock_flag(sk, SOCK_ZAPPED)) |
295 | goto out_unlock; | |
296 | ||
a32e0eec CE |
297 | if (sk->sk_state != TCP_CLOSE) |
298 | goto out_unlock; | |
299 | ||
d5e3a190 GN |
300 | bound_dev_if = sk->sk_bound_dev_if; |
301 | ||
a32e0eec CE |
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) { | |
d5e3a190 GN |
308 | if (addr->l2tp_scope_id) |
309 | bound_dev_if = addr->l2tp_scope_id; | |
a32e0eec CE |
310 | |
311 | /* Binding to link-local address requires an | |
d5e3a190 GN |
312 | * interface. |
313 | */ | |
314 | if (!bound_dev_if) | |
a32e0eec CE |
315 | goto out_unlock_rcu; |
316 | ||
317 | err = -ENODEV; | |
d5e3a190 | 318 | dev = dev_get_by_index_rcu(sock_net(sk), bound_dev_if); |
a32e0eec CE |
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 | ||
d5e3a190 | 333 | write_lock_bh(&l2tp_ip6_lock); |
a9b2dff8 | 334 | if (__l2tp_ip6_bind_lookup(net, &addr->l2tp_addr, NULL, bound_dev_if, |
d5e3a190 GN |
335 | addr->l2tp_conn_id)) { |
336 | write_unlock_bh(&l2tp_ip6_lock); | |
337 | err = -EADDRINUSE; | |
338 | goto out_unlock; | |
339 | } | |
340 | ||
341 | inet->inet_saddr = v4addr; | |
342 | inet->inet_rcv_saddr = v4addr; | |
343 | sk->sk_bound_dev_if = bound_dev_if; | |
efe4208f | 344 | sk->sk_v6_rcv_saddr = addr->l2tp_addr; |
a32e0eec CE |
345 | np->saddr = addr->l2tp_addr; |
346 | ||
347 | l2tp_ip6_sk(sk)->conn_id = addr->l2tp_conn_id; | |
348 | ||
a32e0eec CE |
349 | sk_add_bind_node(sk, &l2tp_ip6_bind_table); |
350 | sk_del_node_init(sk); | |
351 | write_unlock_bh(&l2tp_ip6_lock); | |
352 | ||
c51ce497 | 353 | sock_reset_flag(sk, SOCK_ZAPPED); |
a32e0eec CE |
354 | release_sock(sk); |
355 | return 0; | |
356 | ||
357 | out_unlock_rcu: | |
358 | rcu_read_unlock(); | |
359 | out_unlock: | |
360 | release_sock(sk); | |
a32e0eec | 361 | |
a32e0eec CE |
362 | return err; |
363 | } | |
364 | ||
365 | static int l2tp_ip6_connect(struct sock *sk, struct sockaddr *uaddr, | |
366 | int addr_len) | |
367 | { | |
368 | struct sockaddr_l2tpip6 *lsa = (struct sockaddr_l2tpip6 *) uaddr; | |
369 | struct sockaddr_in6 *usin = (struct sockaddr_in6 *) uaddr; | |
370 | struct in6_addr *daddr; | |
371 | int addr_type; | |
372 | int rc; | |
373 | ||
374 | if (addr_len < sizeof(*lsa)) | |
375 | return -EINVAL; | |
376 | ||
82b276cd HFS |
377 | if (usin->sin6_family != AF_INET6) |
378 | return -EINVAL; | |
379 | ||
a32e0eec CE |
380 | addr_type = ipv6_addr_type(&usin->sin6_addr); |
381 | if (addr_type & IPV6_ADDR_MULTICAST) | |
382 | return -EINVAL; | |
383 | ||
384 | if (addr_type & IPV6_ADDR_MAPPED) { | |
385 | daddr = &usin->sin6_addr; | |
386 | if (ipv4_is_multicast(daddr->s6_addr32[3])) | |
387 | return -EINVAL; | |
388 | } | |
389 | ||
a32e0eec CE |
390 | lock_sock(sk); |
391 | ||
0382a25a GN |
392 | /* Must bind first - autobinding does not work */ |
393 | if (sock_flag(sk, SOCK_ZAPPED)) { | |
394 | rc = -EINVAL; | |
395 | goto out_sk; | |
396 | } | |
397 | ||
398 | rc = __ip6_datagram_connect(sk, uaddr, addr_len); | |
399 | if (rc < 0) | |
400 | goto out_sk; | |
401 | ||
a32e0eec CE |
402 | l2tp_ip6_sk(sk)->peer_conn_id = lsa->l2tp_conn_id; |
403 | ||
404 | write_lock_bh(&l2tp_ip6_lock); | |
405 | hlist_del_init(&sk->sk_bind_node); | |
406 | sk_add_bind_node(sk, &l2tp_ip6_bind_table); | |
407 | write_unlock_bh(&l2tp_ip6_lock); | |
408 | ||
0382a25a | 409 | out_sk: |
a32e0eec CE |
410 | release_sock(sk); |
411 | ||
412 | return rc; | |
413 | } | |
414 | ||
c51ce497 JC |
415 | static int l2tp_ip6_disconnect(struct sock *sk, int flags) |
416 | { | |
417 | if (sock_flag(sk, SOCK_ZAPPED)) | |
418 | return 0; | |
419 | ||
286c72de | 420 | return __udp_disconnect(sk, flags); |
c51ce497 JC |
421 | } |
422 | ||
a32e0eec CE |
423 | static int l2tp_ip6_getname(struct socket *sock, struct sockaddr *uaddr, |
424 | int *uaddr_len, int peer) | |
425 | { | |
426 | struct sockaddr_l2tpip6 *lsa = (struct sockaddr_l2tpip6 *)uaddr; | |
427 | struct sock *sk = sock->sk; | |
428 | struct ipv6_pinfo *np = inet6_sk(sk); | |
429 | struct l2tp_ip6_sock *lsk = l2tp_ip6_sk(sk); | |
430 | ||
431 | lsa->l2tp_family = AF_INET6; | |
432 | lsa->l2tp_flowinfo = 0; | |
433 | lsa->l2tp_scope_id = 0; | |
04d4fbca | 434 | lsa->l2tp_unused = 0; |
a32e0eec CE |
435 | if (peer) { |
436 | if (!lsk->peer_conn_id) | |
437 | return -ENOTCONN; | |
438 | lsa->l2tp_conn_id = lsk->peer_conn_id; | |
efe4208f | 439 | lsa->l2tp_addr = sk->sk_v6_daddr; |
a32e0eec CE |
440 | if (np->sndflow) |
441 | lsa->l2tp_flowinfo = np->flow_label; | |
442 | } else { | |
efe4208f | 443 | if (ipv6_addr_any(&sk->sk_v6_rcv_saddr)) |
a32e0eec CE |
444 | lsa->l2tp_addr = np->saddr; |
445 | else | |
efe4208f | 446 | lsa->l2tp_addr = sk->sk_v6_rcv_saddr; |
a32e0eec CE |
447 | |
448 | lsa->l2tp_conn_id = lsk->conn_id; | |
449 | } | |
450 | if (ipv6_addr_type(&lsa->l2tp_addr) & IPV6_ADDR_LINKLOCAL) | |
451 | lsa->l2tp_scope_id = sk->sk_bound_dev_if; | |
452 | *uaddr_len = sizeof(*lsa); | |
453 | return 0; | |
454 | } | |
455 | ||
456 | static int l2tp_ip6_backlog_recv(struct sock *sk, struct sk_buff *skb) | |
457 | { | |
458 | int rc; | |
459 | ||
460 | /* Charge it to the socket, dropping if the queue is full. */ | |
461 | rc = sock_queue_rcv_skb(sk, skb); | |
462 | if (rc < 0) | |
463 | goto drop; | |
464 | ||
465 | return 0; | |
466 | ||
467 | drop: | |
0e6b5259 | 468 | IP_INC_STATS(sock_net(sk), IPSTATS_MIB_INDISCARDS); |
a32e0eec CE |
469 | kfree_skb(skb); |
470 | return -1; | |
471 | } | |
472 | ||
473 | static int l2tp_ip6_push_pending_frames(struct sock *sk) | |
474 | { | |
475 | struct sk_buff *skb; | |
476 | __be32 *transhdr = NULL; | |
477 | int err = 0; | |
478 | ||
479 | skb = skb_peek(&sk->sk_write_queue); | |
480 | if (skb == NULL) | |
481 | goto out; | |
482 | ||
483 | transhdr = (__be32 *)skb_transport_header(skb); | |
484 | *transhdr = 0; | |
485 | ||
486 | err = ip6_push_pending_frames(sk); | |
487 | ||
488 | out: | |
489 | return err; | |
490 | } | |
491 | ||
492 | /* Userspace will call sendmsg() on the tunnel socket to send L2TP | |
493 | * control frames. | |
494 | */ | |
1b784140 | 495 | static int l2tp_ip6_sendmsg(struct sock *sk, struct msghdr *msg, size_t len) |
a32e0eec CE |
496 | { |
497 | struct ipv6_txoptions opt_space; | |
342dfc30 | 498 | DECLARE_SOCKADDR(struct sockaddr_l2tpip6 *, lsa, msg->msg_name); |
a32e0eec CE |
499 | struct in6_addr *daddr, *final_p, final; |
500 | struct ipv6_pinfo *np = inet6_sk(sk); | |
45f6fad8 | 501 | struct ipv6_txoptions *opt_to_free = NULL; |
a32e0eec CE |
502 | struct ipv6_txoptions *opt = NULL; |
503 | struct ip6_flowlabel *flowlabel = NULL; | |
504 | struct dst_entry *dst = NULL; | |
505 | struct flowi6 fl6; | |
ad1e46a8 | 506 | struct sockcm_cookie sockc_unused = {0}; |
26879da5 | 507 | struct ipcm6_cookie ipc6; |
a32e0eec | 508 | int addr_len = msg->msg_namelen; |
a32e0eec CE |
509 | int transhdrlen = 4; /* zero session-id */ |
510 | int ulen = len + transhdrlen; | |
511 | int err; | |
512 | ||
513 | /* Rough check on arithmetic overflow, | |
514 | better check is made in ip6_append_data(). | |
515 | */ | |
516 | if (len > INT_MAX) | |
517 | return -EMSGSIZE; | |
518 | ||
519 | /* Mirror BSD error message compatibility */ | |
520 | if (msg->msg_flags & MSG_OOB) | |
521 | return -EOPNOTSUPP; | |
522 | ||
523 | /* | |
524 | * Get and verify the address. | |
525 | */ | |
526 | memset(&fl6, 0, sizeof(fl6)); | |
527 | ||
528 | fl6.flowi6_mark = sk->sk_mark; | |
e2d118a1 | 529 | fl6.flowi6_uid = sk->sk_uid; |
a32e0eec | 530 | |
26879da5 WW |
531 | ipc6.hlimit = -1; |
532 | ipc6.tclass = -1; | |
533 | ipc6.dontfrag = -1; | |
534 | ||
a32e0eec CE |
535 | if (lsa) { |
536 | if (addr_len < SIN6_LEN_RFC2133) | |
537 | return -EINVAL; | |
538 | ||
539 | if (lsa->l2tp_family && lsa->l2tp_family != AF_INET6) | |
540 | return -EAFNOSUPPORT; | |
541 | ||
542 | daddr = &lsa->l2tp_addr; | |
543 | if (np->sndflow) { | |
544 | fl6.flowlabel = lsa->l2tp_flowinfo & IPV6_FLOWINFO_MASK; | |
545 | if (fl6.flowlabel&IPV6_FLOWLABEL_MASK) { | |
546 | flowlabel = fl6_sock_lookup(sk, fl6.flowlabel); | |
547 | if (flowlabel == NULL) | |
548 | return -EINVAL; | |
a32e0eec CE |
549 | } |
550 | } | |
551 | ||
552 | /* | |
553 | * Otherwise it will be difficult to maintain | |
554 | * sk->sk_dst_cache. | |
555 | */ | |
556 | if (sk->sk_state == TCP_ESTABLISHED && | |
efe4208f ED |
557 | ipv6_addr_equal(daddr, &sk->sk_v6_daddr)) |
558 | daddr = &sk->sk_v6_daddr; | |
a32e0eec CE |
559 | |
560 | if (addr_len >= sizeof(struct sockaddr_in6) && | |
561 | lsa->l2tp_scope_id && | |
562 | ipv6_addr_type(daddr) & IPV6_ADDR_LINKLOCAL) | |
563 | fl6.flowi6_oif = lsa->l2tp_scope_id; | |
564 | } else { | |
565 | if (sk->sk_state != TCP_ESTABLISHED) | |
566 | return -EDESTADDRREQ; | |
567 | ||
efe4208f | 568 | daddr = &sk->sk_v6_daddr; |
a32e0eec CE |
569 | fl6.flowlabel = np->flow_label; |
570 | } | |
571 | ||
572 | if (fl6.flowi6_oif == 0) | |
573 | fl6.flowi6_oif = sk->sk_bound_dev_if; | |
574 | ||
575 | if (msg->msg_controllen) { | |
576 | opt = &opt_space; | |
577 | memset(opt, 0, sizeof(struct ipv6_txoptions)); | |
578 | opt->tot_len = sizeof(struct ipv6_txoptions); | |
26879da5 | 579 | ipc6.opt = opt; |
a32e0eec | 580 | |
26879da5 WW |
581 | err = ip6_datagram_send_ctl(sock_net(sk), sk, msg, &fl6, &ipc6, |
582 | &sockc_unused); | |
583 | if (err < 0) { | |
a32e0eec CE |
584 | fl6_sock_release(flowlabel); |
585 | return err; | |
586 | } | |
587 | if ((fl6.flowlabel & IPV6_FLOWLABEL_MASK) && !flowlabel) { | |
588 | flowlabel = fl6_sock_lookup(sk, fl6.flowlabel); | |
589 | if (flowlabel == NULL) | |
590 | return -EINVAL; | |
591 | } | |
592 | if (!(opt->opt_nflen|opt->opt_flen)) | |
593 | opt = NULL; | |
594 | } | |
595 | ||
45f6fad8 ED |
596 | if (!opt) { |
597 | opt = txopt_get(np); | |
598 | opt_to_free = opt; | |
599 | } | |
a32e0eec CE |
600 | if (flowlabel) |
601 | opt = fl6_merge_options(&opt_space, flowlabel, opt); | |
602 | opt = ipv6_fixup_options(&opt_space, opt); | |
26879da5 | 603 | ipc6.opt = opt; |
a32e0eec CE |
604 | |
605 | fl6.flowi6_proto = sk->sk_protocol; | |
606 | if (!ipv6_addr_any(daddr)) | |
607 | fl6.daddr = *daddr; | |
608 | else | |
609 | fl6.daddr.s6_addr[15] = 0x1; /* :: means loopback (BSD'ism) */ | |
610 | if (ipv6_addr_any(&fl6.saddr) && !ipv6_addr_any(&np->saddr)) | |
611 | fl6.saddr = np->saddr; | |
612 | ||
613 | final_p = fl6_update_dst(&fl6, opt, &final); | |
614 | ||
615 | if (!fl6.flowi6_oif && ipv6_addr_is_multicast(&fl6.daddr)) | |
616 | fl6.flowi6_oif = np->mcast_oif; | |
617 | else if (!fl6.flowi6_oif) | |
618 | fl6.flowi6_oif = np->ucast_oif; | |
619 | ||
620 | security_sk_classify_flow(sk, flowi6_to_flowi(&fl6)); | |
621 | ||
38b7097b HFS |
622 | if (ipc6.tclass < 0) |
623 | ipc6.tclass = np->tclass; | |
624 | ||
625 | fl6.flowlabel = ip6_make_flowinfo(ipc6.tclass, fl6.flowlabel); | |
626 | ||
0e0d44ab | 627 | dst = ip6_dst_lookup_flow(sk, &fl6, final_p); |
a32e0eec CE |
628 | if (IS_ERR(dst)) { |
629 | err = PTR_ERR(dst); | |
630 | goto out; | |
631 | } | |
632 | ||
26879da5 WW |
633 | if (ipc6.hlimit < 0) |
634 | ipc6.hlimit = ip6_sk_dst_hoplimit(np, &fl6, dst); | |
a32e0eec | 635 | |
26879da5 WW |
636 | if (ipc6.dontfrag < 0) |
637 | ipc6.dontfrag = np->dontfrag; | |
a32e0eec CE |
638 | |
639 | if (msg->msg_flags & MSG_CONFIRM) | |
640 | goto do_confirm; | |
641 | ||
642 | back_from_confirm: | |
643 | lock_sock(sk); | |
f69e6d13 | 644 | err = ip6_append_data(sk, ip_generic_getfrag, msg, |
26879da5 | 645 | ulen, transhdrlen, &ipc6, |
a32e0eec | 646 | &fl6, (struct rt6_info *)dst, |
26879da5 | 647 | msg->msg_flags, &sockc_unused); |
a32e0eec CE |
648 | if (err) |
649 | ip6_flush_pending_frames(sk); | |
650 | else if (!(msg->msg_flags & MSG_MORE)) | |
651 | err = l2tp_ip6_push_pending_frames(sk); | |
652 | release_sock(sk); | |
653 | done: | |
654 | dst_release(dst); | |
655 | out: | |
656 | fl6_sock_release(flowlabel); | |
45f6fad8 | 657 | txopt_put(opt_to_free); |
a32e0eec CE |
658 | |
659 | return err < 0 ? err : len; | |
660 | ||
661 | do_confirm: | |
0dec879f JA |
662 | if (msg->msg_flags & MSG_PROBE) |
663 | dst_confirm_neigh(dst, &fl6.daddr); | |
a32e0eec CE |
664 | if (!(msg->msg_flags & MSG_PROBE) || len) |
665 | goto back_from_confirm; | |
666 | err = 0; | |
667 | goto done; | |
668 | } | |
669 | ||
1b784140 YX |
670 | static int l2tp_ip6_recvmsg(struct sock *sk, struct msghdr *msg, size_t len, |
671 | int noblock, int flags, int *addr_len) | |
a32e0eec | 672 | { |
700163db | 673 | struct ipv6_pinfo *np = inet6_sk(sk); |
342dfc30 | 674 | DECLARE_SOCKADDR(struct sockaddr_l2tpip6 *, lsa, msg->msg_name); |
a32e0eec CE |
675 | size_t copied = 0; |
676 | int err = -EOPNOTSUPP; | |
677 | struct sk_buff *skb; | |
678 | ||
679 | if (flags & MSG_OOB) | |
680 | goto out; | |
681 | ||
682 | if (addr_len) | |
683 | *addr_len = sizeof(*lsa); | |
684 | ||
685 | if (flags & MSG_ERRQUEUE) | |
85fbaa75 | 686 | return ipv6_recv_error(sk, msg, len, addr_len); |
a32e0eec CE |
687 | |
688 | skb = skb_recv_datagram(sk, flags, noblock, &err); | |
689 | if (!skb) | |
690 | goto out; | |
691 | ||
692 | copied = skb->len; | |
693 | if (len < copied) { | |
694 | msg->msg_flags |= MSG_TRUNC; | |
695 | copied = len; | |
696 | } | |
697 | ||
51f3d02b | 698 | err = skb_copy_datagram_msg(skb, 0, msg, copied); |
a32e0eec CE |
699 | if (err) |
700 | goto done; | |
701 | ||
702 | sock_recv_timestamp(msg, sk, skb); | |
703 | ||
704 | /* Copy the address. */ | |
705 | if (lsa) { | |
706 | lsa->l2tp_family = AF_INET6; | |
707 | lsa->l2tp_unused = 0; | |
708 | lsa->l2tp_addr = ipv6_hdr(skb)->saddr; | |
709 | lsa->l2tp_flowinfo = 0; | |
710 | lsa->l2tp_scope_id = 0; | |
b860d3cc | 711 | lsa->l2tp_conn_id = 0; |
a32e0eec | 712 | if (ipv6_addr_type(&lsa->l2tp_addr) & IPV6_ADDR_LINKLOCAL) |
4330487a | 713 | lsa->l2tp_scope_id = inet6_iif(skb); |
a32e0eec CE |
714 | } |
715 | ||
700163db TP |
716 | if (np->rxopt.all) |
717 | ip6_datagram_recv_ctl(sk, msg, skb); | |
a32e0eec CE |
718 | |
719 | if (flags & MSG_TRUNC) | |
720 | copied = skb->len; | |
721 | done: | |
722 | skb_free_datagram(sk, skb); | |
723 | out: | |
724 | return err ? err : copied; | |
725 | } | |
726 | ||
727 | static struct proto l2tp_ip6_prot = { | |
728 | .name = "L2TP/IPv6", | |
729 | .owner = THIS_MODULE, | |
730 | .init = l2tp_ip6_open, | |
731 | .close = l2tp_ip6_close, | |
732 | .bind = l2tp_ip6_bind, | |
733 | .connect = l2tp_ip6_connect, | |
c51ce497 | 734 | .disconnect = l2tp_ip6_disconnect, |
72fb96e7 | 735 | .ioctl = l2tp_ioctl, |
a32e0eec CE |
736 | .destroy = l2tp_ip6_destroy_sock, |
737 | .setsockopt = ipv6_setsockopt, | |
738 | .getsockopt = ipv6_getsockopt, | |
739 | .sendmsg = l2tp_ip6_sendmsg, | |
740 | .recvmsg = l2tp_ip6_recvmsg, | |
741 | .backlog_rcv = l2tp_ip6_backlog_recv, | |
496611d7 | 742 | .hash = inet6_hash, |
a32e0eec CE |
743 | .unhash = inet_unhash, |
744 | .obj_size = sizeof(struct l2tp_ip6_sock), | |
745 | #ifdef CONFIG_COMPAT | |
746 | .compat_setsockopt = compat_ipv6_setsockopt, | |
747 | .compat_getsockopt = compat_ipv6_getsockopt, | |
748 | #endif | |
749 | }; | |
750 | ||
751 | static const struct proto_ops l2tp_ip6_ops = { | |
752 | .family = PF_INET6, | |
753 | .owner = THIS_MODULE, | |
754 | .release = inet6_release, | |
755 | .bind = inet6_bind, | |
756 | .connect = inet_dgram_connect, | |
757 | .socketpair = sock_no_socketpair, | |
758 | .accept = sock_no_accept, | |
759 | .getname = l2tp_ip6_getname, | |
760 | .poll = datagram_poll, | |
761 | .ioctl = inet6_ioctl, | |
762 | .listen = sock_no_listen, | |
763 | .shutdown = inet_shutdown, | |
764 | .setsockopt = sock_common_setsockopt, | |
765 | .getsockopt = sock_common_getsockopt, | |
766 | .sendmsg = inet_sendmsg, | |
767 | .recvmsg = sock_common_recvmsg, | |
768 | .mmap = sock_no_mmap, | |
769 | .sendpage = sock_no_sendpage, | |
770 | #ifdef CONFIG_COMPAT | |
771 | .compat_setsockopt = compat_sock_common_setsockopt, | |
772 | .compat_getsockopt = compat_sock_common_getsockopt, | |
773 | #endif | |
774 | }; | |
775 | ||
776 | static struct inet_protosw l2tp_ip6_protosw = { | |
777 | .type = SOCK_DGRAM, | |
778 | .protocol = IPPROTO_L2TP, | |
779 | .prot = &l2tp_ip6_prot, | |
780 | .ops = &l2tp_ip6_ops, | |
a32e0eec CE |
781 | }; |
782 | ||
783 | static struct inet6_protocol l2tp_ip6_protocol __read_mostly = { | |
784 | .handler = l2tp_ip6_recv, | |
785 | }; | |
786 | ||
787 | static int __init l2tp_ip6_init(void) | |
788 | { | |
789 | int err; | |
790 | ||
a4ca44fa | 791 | pr_info("L2TP IP encapsulation support for IPv6 (L2TPv3)\n"); |
a32e0eec CE |
792 | |
793 | err = proto_register(&l2tp_ip6_prot, 1); | |
794 | if (err != 0) | |
795 | goto out; | |
796 | ||
797 | err = inet6_add_protocol(&l2tp_ip6_protocol, IPPROTO_L2TP); | |
798 | if (err) | |
799 | goto out1; | |
800 | ||
801 | inet6_register_protosw(&l2tp_ip6_protosw); | |
802 | return 0; | |
803 | ||
804 | out1: | |
805 | proto_unregister(&l2tp_ip6_prot); | |
806 | out: | |
807 | return err; | |
808 | } | |
809 | ||
810 | static void __exit l2tp_ip6_exit(void) | |
811 | { | |
812 | inet6_unregister_protosw(&l2tp_ip6_protosw); | |
813 | inet6_del_protocol(&l2tp_ip6_protocol, IPPROTO_L2TP); | |
814 | proto_unregister(&l2tp_ip6_prot); | |
815 | } | |
816 | ||
817 | module_init(l2tp_ip6_init); | |
818 | module_exit(l2tp_ip6_exit); | |
819 | ||
820 | MODULE_LICENSE("GPL"); | |
821 | MODULE_AUTHOR("Chris Elston <celston@katalix.com>"); | |
822 | MODULE_DESCRIPTION("L2TP IP encapsulation for IPv6"); | |
823 | MODULE_VERSION("1.0"); | |
824 | ||
825 | /* Use the value of SOCK_DGRAM (2) directory, because __stringify doesn't like | |
826 | * enums | |
827 | */ | |
828 | MODULE_ALIAS_NET_PF_PROTO_TYPE(PF_INET6, 2, IPPROTO_L2TP); | |
163c2e25 | 829 | MODULE_ALIAS_NET_PF_PROTO(PF_INET6, IPPROTO_L2TP); |