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. */ | |
a4346210 | 159 | session = l2tp_session_get(net, NULL, session_id); |
61b9a047 | 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 | 221 | discard_sess: |
61b9a047 GN |
222 | l2tp_session_dec_refcount(session); |
223 | goto discard; | |
224 | ||
a32e0eec CE |
225 | discard_put: |
226 | sock_put(sk); | |
227 | ||
228 | discard: | |
229 | kfree_skb(skb); | |
230 | return 0; | |
231 | } | |
232 | ||
233 | static int l2tp_ip6_open(struct sock *sk) | |
234 | { | |
235 | /* Prevent autobind. We don't have ports. */ | |
236 | inet_sk(sk)->inet_num = IPPROTO_L2TP; | |
237 | ||
238 | write_lock_bh(&l2tp_ip6_lock); | |
239 | sk_add_node(sk, &l2tp_ip6_table); | |
240 | write_unlock_bh(&l2tp_ip6_lock); | |
241 | ||
242 | return 0; | |
243 | } | |
244 | ||
245 | static void l2tp_ip6_close(struct sock *sk, long timeout) | |
246 | { | |
247 | write_lock_bh(&l2tp_ip6_lock); | |
248 | hlist_del_init(&sk->sk_bind_node); | |
249 | sk_del_node_init(sk); | |
250 | write_unlock_bh(&l2tp_ip6_lock); | |
251 | ||
252 | sk_common_release(sk); | |
253 | } | |
254 | ||
255 | static void l2tp_ip6_destroy_sock(struct sock *sk) | |
256 | { | |
93606317 TP |
257 | struct l2tp_tunnel *tunnel = l2tp_sock_to_tunnel(sk); |
258 | ||
a32e0eec CE |
259 | lock_sock(sk); |
260 | ip6_flush_pending_frames(sk); | |
261 | release_sock(sk); | |
262 | ||
93606317 TP |
263 | if (tunnel) { |
264 | l2tp_tunnel_closeall(tunnel); | |
265 | sock_put(sk); | |
266 | } | |
267 | ||
a32e0eec CE |
268 | inet6_destroy_sock(sk); |
269 | } | |
270 | ||
271 | static int l2tp_ip6_bind(struct sock *sk, struct sockaddr *uaddr, int addr_len) | |
272 | { | |
273 | struct inet_sock *inet = inet_sk(sk); | |
274 | struct ipv6_pinfo *np = inet6_sk(sk); | |
275 | struct sockaddr_l2tpip6 *addr = (struct sockaddr_l2tpip6 *) uaddr; | |
0e6b5259 | 276 | struct net *net = sock_net(sk); |
a32e0eec | 277 | __be32 v4addr = 0; |
d5e3a190 | 278 | int bound_dev_if; |
a32e0eec CE |
279 | int addr_type; |
280 | int err; | |
281 | ||
c51ce497 JC |
282 | if (addr->l2tp_family != AF_INET6) |
283 | return -EINVAL; | |
a32e0eec CE |
284 | if (addr_len < sizeof(*addr)) |
285 | return -EINVAL; | |
286 | ||
287 | addr_type = ipv6_addr_type(&addr->l2tp_addr); | |
288 | ||
289 | /* l2tp_ip6 sockets are IPv6 only */ | |
290 | if (addr_type == IPV6_ADDR_MAPPED) | |
291 | return -EADDRNOTAVAIL; | |
292 | ||
293 | /* L2TP is point-point, not multicast */ | |
294 | if (addr_type & IPV6_ADDR_MULTICAST) | |
295 | return -EADDRNOTAVAIL; | |
296 | ||
a32e0eec CE |
297 | lock_sock(sk); |
298 | ||
299 | err = -EINVAL; | |
32c23116 GN |
300 | if (!sock_flag(sk, SOCK_ZAPPED)) |
301 | goto out_unlock; | |
302 | ||
a32e0eec CE |
303 | if (sk->sk_state != TCP_CLOSE) |
304 | goto out_unlock; | |
305 | ||
d5e3a190 GN |
306 | bound_dev_if = sk->sk_bound_dev_if; |
307 | ||
a32e0eec CE |
308 | /* Check if the address belongs to the host. */ |
309 | rcu_read_lock(); | |
310 | if (addr_type != IPV6_ADDR_ANY) { | |
311 | struct net_device *dev = NULL; | |
312 | ||
313 | if (addr_type & IPV6_ADDR_LINKLOCAL) { | |
d5e3a190 GN |
314 | if (addr->l2tp_scope_id) |
315 | bound_dev_if = addr->l2tp_scope_id; | |
a32e0eec CE |
316 | |
317 | /* Binding to link-local address requires an | |
d5e3a190 GN |
318 | * interface. |
319 | */ | |
320 | if (!bound_dev_if) | |
a32e0eec CE |
321 | goto out_unlock_rcu; |
322 | ||
323 | err = -ENODEV; | |
d5e3a190 | 324 | dev = dev_get_by_index_rcu(sock_net(sk), bound_dev_if); |
a32e0eec CE |
325 | if (!dev) |
326 | goto out_unlock_rcu; | |
327 | } | |
328 | ||
329 | /* ipv4 addr of the socket is invalid. Only the | |
330 | * unspecified and mapped address have a v4 equivalent. | |
331 | */ | |
332 | v4addr = LOOPBACK4_IPV6; | |
333 | err = -EADDRNOTAVAIL; | |
334 | if (!ipv6_chk_addr(sock_net(sk), &addr->l2tp_addr, dev, 0)) | |
335 | goto out_unlock_rcu; | |
336 | } | |
337 | rcu_read_unlock(); | |
338 | ||
d5e3a190 | 339 | write_lock_bh(&l2tp_ip6_lock); |
a9b2dff8 | 340 | if (__l2tp_ip6_bind_lookup(net, &addr->l2tp_addr, NULL, bound_dev_if, |
d5e3a190 GN |
341 | addr->l2tp_conn_id)) { |
342 | write_unlock_bh(&l2tp_ip6_lock); | |
343 | err = -EADDRINUSE; | |
344 | goto out_unlock; | |
345 | } | |
346 | ||
347 | inet->inet_saddr = v4addr; | |
348 | inet->inet_rcv_saddr = v4addr; | |
349 | sk->sk_bound_dev_if = bound_dev_if; | |
efe4208f | 350 | sk->sk_v6_rcv_saddr = addr->l2tp_addr; |
a32e0eec CE |
351 | np->saddr = addr->l2tp_addr; |
352 | ||
353 | l2tp_ip6_sk(sk)->conn_id = addr->l2tp_conn_id; | |
354 | ||
a32e0eec CE |
355 | sk_add_bind_node(sk, &l2tp_ip6_bind_table); |
356 | sk_del_node_init(sk); | |
357 | write_unlock_bh(&l2tp_ip6_lock); | |
358 | ||
c51ce497 | 359 | sock_reset_flag(sk, SOCK_ZAPPED); |
a32e0eec CE |
360 | release_sock(sk); |
361 | return 0; | |
362 | ||
363 | out_unlock_rcu: | |
364 | rcu_read_unlock(); | |
365 | out_unlock: | |
366 | release_sock(sk); | |
a32e0eec | 367 | |
a32e0eec CE |
368 | return err; |
369 | } | |
370 | ||
371 | static int l2tp_ip6_connect(struct sock *sk, struct sockaddr *uaddr, | |
372 | int addr_len) | |
373 | { | |
374 | struct sockaddr_l2tpip6 *lsa = (struct sockaddr_l2tpip6 *) uaddr; | |
375 | struct sockaddr_in6 *usin = (struct sockaddr_in6 *) uaddr; | |
376 | struct in6_addr *daddr; | |
377 | int addr_type; | |
378 | int rc; | |
379 | ||
380 | if (addr_len < sizeof(*lsa)) | |
381 | return -EINVAL; | |
382 | ||
82b276cd HFS |
383 | if (usin->sin6_family != AF_INET6) |
384 | return -EINVAL; | |
385 | ||
a32e0eec CE |
386 | addr_type = ipv6_addr_type(&usin->sin6_addr); |
387 | if (addr_type & IPV6_ADDR_MULTICAST) | |
388 | return -EINVAL; | |
389 | ||
390 | if (addr_type & IPV6_ADDR_MAPPED) { | |
391 | daddr = &usin->sin6_addr; | |
392 | if (ipv4_is_multicast(daddr->s6_addr32[3])) | |
393 | return -EINVAL; | |
394 | } | |
395 | ||
a32e0eec CE |
396 | lock_sock(sk); |
397 | ||
0382a25a GN |
398 | /* Must bind first - autobinding does not work */ |
399 | if (sock_flag(sk, SOCK_ZAPPED)) { | |
400 | rc = -EINVAL; | |
401 | goto out_sk; | |
402 | } | |
403 | ||
404 | rc = __ip6_datagram_connect(sk, uaddr, addr_len); | |
405 | if (rc < 0) | |
406 | goto out_sk; | |
407 | ||
a32e0eec CE |
408 | l2tp_ip6_sk(sk)->peer_conn_id = lsa->l2tp_conn_id; |
409 | ||
410 | write_lock_bh(&l2tp_ip6_lock); | |
411 | hlist_del_init(&sk->sk_bind_node); | |
412 | sk_add_bind_node(sk, &l2tp_ip6_bind_table); | |
413 | write_unlock_bh(&l2tp_ip6_lock); | |
414 | ||
0382a25a | 415 | out_sk: |
a32e0eec CE |
416 | release_sock(sk); |
417 | ||
418 | return rc; | |
419 | } | |
420 | ||
c51ce497 JC |
421 | static int l2tp_ip6_disconnect(struct sock *sk, int flags) |
422 | { | |
423 | if (sock_flag(sk, SOCK_ZAPPED)) | |
424 | return 0; | |
425 | ||
286c72de | 426 | return __udp_disconnect(sk, flags); |
c51ce497 JC |
427 | } |
428 | ||
a32e0eec CE |
429 | static int l2tp_ip6_getname(struct socket *sock, struct sockaddr *uaddr, |
430 | int *uaddr_len, int peer) | |
431 | { | |
432 | struct sockaddr_l2tpip6 *lsa = (struct sockaddr_l2tpip6 *)uaddr; | |
433 | struct sock *sk = sock->sk; | |
434 | struct ipv6_pinfo *np = inet6_sk(sk); | |
435 | struct l2tp_ip6_sock *lsk = l2tp_ip6_sk(sk); | |
436 | ||
437 | lsa->l2tp_family = AF_INET6; | |
438 | lsa->l2tp_flowinfo = 0; | |
439 | lsa->l2tp_scope_id = 0; | |
04d4fbca | 440 | lsa->l2tp_unused = 0; |
a32e0eec CE |
441 | if (peer) { |
442 | if (!lsk->peer_conn_id) | |
443 | return -ENOTCONN; | |
444 | lsa->l2tp_conn_id = lsk->peer_conn_id; | |
efe4208f | 445 | lsa->l2tp_addr = sk->sk_v6_daddr; |
a32e0eec CE |
446 | if (np->sndflow) |
447 | lsa->l2tp_flowinfo = np->flow_label; | |
448 | } else { | |
efe4208f | 449 | if (ipv6_addr_any(&sk->sk_v6_rcv_saddr)) |
a32e0eec CE |
450 | lsa->l2tp_addr = np->saddr; |
451 | else | |
efe4208f | 452 | lsa->l2tp_addr = sk->sk_v6_rcv_saddr; |
a32e0eec CE |
453 | |
454 | lsa->l2tp_conn_id = lsk->conn_id; | |
455 | } | |
456 | if (ipv6_addr_type(&lsa->l2tp_addr) & IPV6_ADDR_LINKLOCAL) | |
457 | lsa->l2tp_scope_id = sk->sk_bound_dev_if; | |
458 | *uaddr_len = sizeof(*lsa); | |
459 | return 0; | |
460 | } | |
461 | ||
462 | static int l2tp_ip6_backlog_recv(struct sock *sk, struct sk_buff *skb) | |
463 | { | |
464 | int rc; | |
465 | ||
466 | /* Charge it to the socket, dropping if the queue is full. */ | |
467 | rc = sock_queue_rcv_skb(sk, skb); | |
468 | if (rc < 0) | |
469 | goto drop; | |
470 | ||
471 | return 0; | |
472 | ||
473 | drop: | |
0e6b5259 | 474 | IP_INC_STATS(sock_net(sk), IPSTATS_MIB_INDISCARDS); |
a32e0eec CE |
475 | kfree_skb(skb); |
476 | return -1; | |
477 | } | |
478 | ||
479 | static int l2tp_ip6_push_pending_frames(struct sock *sk) | |
480 | { | |
481 | struct sk_buff *skb; | |
482 | __be32 *transhdr = NULL; | |
483 | int err = 0; | |
484 | ||
485 | skb = skb_peek(&sk->sk_write_queue); | |
486 | if (skb == NULL) | |
487 | goto out; | |
488 | ||
489 | transhdr = (__be32 *)skb_transport_header(skb); | |
490 | *transhdr = 0; | |
491 | ||
492 | err = ip6_push_pending_frames(sk); | |
493 | ||
494 | out: | |
495 | return err; | |
496 | } | |
497 | ||
498 | /* Userspace will call sendmsg() on the tunnel socket to send L2TP | |
499 | * control frames. | |
500 | */ | |
1b784140 | 501 | static int l2tp_ip6_sendmsg(struct sock *sk, struct msghdr *msg, size_t len) |
a32e0eec CE |
502 | { |
503 | struct ipv6_txoptions opt_space; | |
342dfc30 | 504 | DECLARE_SOCKADDR(struct sockaddr_l2tpip6 *, lsa, msg->msg_name); |
a32e0eec CE |
505 | struct in6_addr *daddr, *final_p, final; |
506 | struct ipv6_pinfo *np = inet6_sk(sk); | |
45f6fad8 | 507 | struct ipv6_txoptions *opt_to_free = NULL; |
a32e0eec CE |
508 | struct ipv6_txoptions *opt = NULL; |
509 | struct ip6_flowlabel *flowlabel = NULL; | |
510 | struct dst_entry *dst = NULL; | |
511 | struct flowi6 fl6; | |
ad1e46a8 | 512 | struct sockcm_cookie sockc_unused = {0}; |
26879da5 | 513 | struct ipcm6_cookie ipc6; |
a32e0eec | 514 | int addr_len = msg->msg_namelen; |
a32e0eec CE |
515 | int transhdrlen = 4; /* zero session-id */ |
516 | int ulen = len + transhdrlen; | |
517 | int err; | |
518 | ||
519 | /* Rough check on arithmetic overflow, | |
520 | better check is made in ip6_append_data(). | |
521 | */ | |
522 | if (len > INT_MAX) | |
523 | return -EMSGSIZE; | |
524 | ||
525 | /* Mirror BSD error message compatibility */ | |
526 | if (msg->msg_flags & MSG_OOB) | |
527 | return -EOPNOTSUPP; | |
528 | ||
529 | /* | |
530 | * Get and verify the address. | |
531 | */ | |
532 | memset(&fl6, 0, sizeof(fl6)); | |
533 | ||
534 | fl6.flowi6_mark = sk->sk_mark; | |
e2d118a1 | 535 | fl6.flowi6_uid = sk->sk_uid; |
a32e0eec | 536 | |
26879da5 WW |
537 | ipc6.hlimit = -1; |
538 | ipc6.tclass = -1; | |
539 | ipc6.dontfrag = -1; | |
540 | ||
a32e0eec CE |
541 | if (lsa) { |
542 | if (addr_len < SIN6_LEN_RFC2133) | |
543 | return -EINVAL; | |
544 | ||
545 | if (lsa->l2tp_family && lsa->l2tp_family != AF_INET6) | |
546 | return -EAFNOSUPPORT; | |
547 | ||
548 | daddr = &lsa->l2tp_addr; | |
549 | if (np->sndflow) { | |
550 | fl6.flowlabel = lsa->l2tp_flowinfo & IPV6_FLOWINFO_MASK; | |
551 | if (fl6.flowlabel&IPV6_FLOWLABEL_MASK) { | |
552 | flowlabel = fl6_sock_lookup(sk, fl6.flowlabel); | |
553 | if (flowlabel == NULL) | |
554 | return -EINVAL; | |
a32e0eec CE |
555 | } |
556 | } | |
557 | ||
558 | /* | |
559 | * Otherwise it will be difficult to maintain | |
560 | * sk->sk_dst_cache. | |
561 | */ | |
562 | if (sk->sk_state == TCP_ESTABLISHED && | |
efe4208f ED |
563 | ipv6_addr_equal(daddr, &sk->sk_v6_daddr)) |
564 | daddr = &sk->sk_v6_daddr; | |
a32e0eec CE |
565 | |
566 | if (addr_len >= sizeof(struct sockaddr_in6) && | |
567 | lsa->l2tp_scope_id && | |
568 | ipv6_addr_type(daddr) & IPV6_ADDR_LINKLOCAL) | |
569 | fl6.flowi6_oif = lsa->l2tp_scope_id; | |
570 | } else { | |
571 | if (sk->sk_state != TCP_ESTABLISHED) | |
572 | return -EDESTADDRREQ; | |
573 | ||
efe4208f | 574 | daddr = &sk->sk_v6_daddr; |
a32e0eec CE |
575 | fl6.flowlabel = np->flow_label; |
576 | } | |
577 | ||
578 | if (fl6.flowi6_oif == 0) | |
579 | fl6.flowi6_oif = sk->sk_bound_dev_if; | |
580 | ||
581 | if (msg->msg_controllen) { | |
582 | opt = &opt_space; | |
583 | memset(opt, 0, sizeof(struct ipv6_txoptions)); | |
584 | opt->tot_len = sizeof(struct ipv6_txoptions); | |
26879da5 | 585 | ipc6.opt = opt; |
a32e0eec | 586 | |
26879da5 WW |
587 | err = ip6_datagram_send_ctl(sock_net(sk), sk, msg, &fl6, &ipc6, |
588 | &sockc_unused); | |
589 | if (err < 0) { | |
a32e0eec CE |
590 | fl6_sock_release(flowlabel); |
591 | return err; | |
592 | } | |
593 | if ((fl6.flowlabel & IPV6_FLOWLABEL_MASK) && !flowlabel) { | |
594 | flowlabel = fl6_sock_lookup(sk, fl6.flowlabel); | |
595 | if (flowlabel == NULL) | |
596 | return -EINVAL; | |
597 | } | |
598 | if (!(opt->opt_nflen|opt->opt_flen)) | |
599 | opt = NULL; | |
600 | } | |
601 | ||
45f6fad8 ED |
602 | if (!opt) { |
603 | opt = txopt_get(np); | |
604 | opt_to_free = opt; | |
605 | } | |
a32e0eec CE |
606 | if (flowlabel) |
607 | opt = fl6_merge_options(&opt_space, flowlabel, opt); | |
608 | opt = ipv6_fixup_options(&opt_space, opt); | |
26879da5 | 609 | ipc6.opt = opt; |
a32e0eec CE |
610 | |
611 | fl6.flowi6_proto = sk->sk_protocol; | |
612 | if (!ipv6_addr_any(daddr)) | |
613 | fl6.daddr = *daddr; | |
614 | else | |
615 | fl6.daddr.s6_addr[15] = 0x1; /* :: means loopback (BSD'ism) */ | |
616 | if (ipv6_addr_any(&fl6.saddr) && !ipv6_addr_any(&np->saddr)) | |
617 | fl6.saddr = np->saddr; | |
618 | ||
619 | final_p = fl6_update_dst(&fl6, opt, &final); | |
620 | ||
621 | if (!fl6.flowi6_oif && ipv6_addr_is_multicast(&fl6.daddr)) | |
622 | fl6.flowi6_oif = np->mcast_oif; | |
623 | else if (!fl6.flowi6_oif) | |
624 | fl6.flowi6_oif = np->ucast_oif; | |
625 | ||
626 | security_sk_classify_flow(sk, flowi6_to_flowi(&fl6)); | |
627 | ||
38b7097b HFS |
628 | if (ipc6.tclass < 0) |
629 | ipc6.tclass = np->tclass; | |
630 | ||
631 | fl6.flowlabel = ip6_make_flowinfo(ipc6.tclass, fl6.flowlabel); | |
632 | ||
0e0d44ab | 633 | dst = ip6_dst_lookup_flow(sk, &fl6, final_p); |
a32e0eec CE |
634 | if (IS_ERR(dst)) { |
635 | err = PTR_ERR(dst); | |
636 | goto out; | |
637 | } | |
638 | ||
26879da5 WW |
639 | if (ipc6.hlimit < 0) |
640 | ipc6.hlimit = ip6_sk_dst_hoplimit(np, &fl6, dst); | |
a32e0eec | 641 | |
26879da5 WW |
642 | if (ipc6.dontfrag < 0) |
643 | ipc6.dontfrag = np->dontfrag; | |
a32e0eec CE |
644 | |
645 | if (msg->msg_flags & MSG_CONFIRM) | |
646 | goto do_confirm; | |
647 | ||
648 | back_from_confirm: | |
649 | lock_sock(sk); | |
f69e6d13 | 650 | err = ip6_append_data(sk, ip_generic_getfrag, msg, |
26879da5 | 651 | ulen, transhdrlen, &ipc6, |
a32e0eec | 652 | &fl6, (struct rt6_info *)dst, |
26879da5 | 653 | msg->msg_flags, &sockc_unused); |
a32e0eec CE |
654 | if (err) |
655 | ip6_flush_pending_frames(sk); | |
656 | else if (!(msg->msg_flags & MSG_MORE)) | |
657 | err = l2tp_ip6_push_pending_frames(sk); | |
658 | release_sock(sk); | |
659 | done: | |
660 | dst_release(dst); | |
661 | out: | |
662 | fl6_sock_release(flowlabel); | |
45f6fad8 | 663 | txopt_put(opt_to_free); |
a32e0eec CE |
664 | |
665 | return err < 0 ? err : len; | |
666 | ||
667 | do_confirm: | |
0dec879f JA |
668 | if (msg->msg_flags & MSG_PROBE) |
669 | dst_confirm_neigh(dst, &fl6.daddr); | |
a32e0eec CE |
670 | if (!(msg->msg_flags & MSG_PROBE) || len) |
671 | goto back_from_confirm; | |
672 | err = 0; | |
673 | goto done; | |
674 | } | |
675 | ||
1b784140 YX |
676 | static int l2tp_ip6_recvmsg(struct sock *sk, struct msghdr *msg, size_t len, |
677 | int noblock, int flags, int *addr_len) | |
a32e0eec | 678 | { |
700163db | 679 | struct ipv6_pinfo *np = inet6_sk(sk); |
342dfc30 | 680 | DECLARE_SOCKADDR(struct sockaddr_l2tpip6 *, lsa, msg->msg_name); |
a32e0eec CE |
681 | 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) | |
85fbaa75 | 692 | return ipv6_recv_error(sk, msg, len, addr_len); |
a32e0eec CE |
693 | |
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 | ||
51f3d02b | 704 | err = skb_copy_datagram_msg(skb, 0, msg, copied); |
a32e0eec CE |
705 | 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; | |
b860d3cc | 717 | lsa->l2tp_conn_id = 0; |
a32e0eec | 718 | if (ipv6_addr_type(&lsa->l2tp_addr) & IPV6_ADDR_LINKLOCAL) |
4330487a | 719 | lsa->l2tp_scope_id = inet6_iif(skb); |
a32e0eec CE |
720 | } |
721 | ||
700163db TP |
722 | if (np->rxopt.all) |
723 | ip6_datagram_recv_ctl(sk, msg, skb); | |
a32e0eec CE |
724 | |
725 | if (flags & MSG_TRUNC) | |
726 | copied = skb->len; | |
727 | done: | |
728 | skb_free_datagram(sk, skb); | |
729 | out: | |
730 | return err ? err : copied; | |
731 | } | |
732 | ||
733 | static 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, | |
c51ce497 | 740 | .disconnect = l2tp_ip6_disconnect, |
72fb96e7 | 741 | .ioctl = l2tp_ioctl, |
a32e0eec CE |
742 | .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, | |
496611d7 | 748 | .hash = inet6_hash, |
a32e0eec CE |
749 | .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 | ||
757 | static 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 | ||
782 | static struct inet_protosw l2tp_ip6_protosw = { | |
783 | .type = SOCK_DGRAM, | |
784 | .protocol = IPPROTO_L2TP, | |
785 | .prot = &l2tp_ip6_prot, | |
786 | .ops = &l2tp_ip6_ops, | |
a32e0eec CE |
787 | }; |
788 | ||
789 | static struct inet6_protocol l2tp_ip6_protocol __read_mostly = { | |
790 | .handler = l2tp_ip6_recv, | |
791 | }; | |
792 | ||
793 | static int __init l2tp_ip6_init(void) | |
794 | { | |
795 | int err; | |
796 | ||
a4ca44fa | 797 | pr_info("L2TP IP encapsulation support for IPv6 (L2TPv3)\n"); |
a32e0eec CE |
798 | |
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 | ||
810 | out1: | |
811 | proto_unregister(&l2tp_ip6_prot); | |
812 | out: | |
813 | return err; | |
814 | } | |
815 | ||
816 | static 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 | ||
823 | module_init(l2tp_ip6_init); | |
824 | module_exit(l2tp_ip6_exit); | |
825 | ||
826 | MODULE_LICENSE("GPL"); | |
827 | MODULE_AUTHOR("Chris Elston <celston@katalix.com>"); | |
828 | MODULE_DESCRIPTION("L2TP IP encapsulation for IPv6"); | |
829 | MODULE_VERSION("1.0"); | |
830 | ||
831 | /* Use the value of SOCK_DGRAM (2) directory, because __stringify doesn't like | |
832 | * enums | |
833 | */ | |
834 | MODULE_ALIAS_NET_PF_PROTO_TYPE(PF_INET6, 2, IPPROTO_L2TP); | |
163c2e25 | 835 | MODULE_ALIAS_NET_PF_PROTO(PF_INET6, IPPROTO_L2TP); |