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); |
a32e0eec CE |
194 | if (tunnel != NULL) |
195 | sk = tunnel->sock; | |
196 | else { | |
197 | struct ipv6hdr *iph = ipv6_hdr(skb); | |
198 | ||
199 | read_lock_bh(&l2tp_ip6_lock); | |
a9b2dff8 GN |
200 | sk = __l2tp_ip6_bind_lookup(net, &iph->daddr, &iph->saddr, |
201 | inet6_iif(skb), tunnel_id); | |
a3c18422 GN |
202 | if (!sk) { |
203 | read_unlock_bh(&l2tp_ip6_lock); | |
204 | goto discard; | |
205 | } | |
206 | ||
207 | sock_hold(sk); | |
a32e0eec CE |
208 | read_unlock_bh(&l2tp_ip6_lock); |
209 | } | |
210 | ||
a32e0eec CE |
211 | if (!xfrm6_policy_check(sk, XFRM_POLICY_IN, skb)) |
212 | goto discard_put; | |
213 | ||
214 | nf_reset(skb); | |
215 | ||
216 | return sk_receive_skb(sk, skb, 1); | |
217 | ||
218 | discard_put: | |
219 | sock_put(sk); | |
220 | ||
221 | discard: | |
222 | kfree_skb(skb); | |
223 | return 0; | |
224 | } | |
225 | ||
226 | static int l2tp_ip6_open(struct sock *sk) | |
227 | { | |
228 | /* Prevent autobind. We don't have ports. */ | |
229 | inet_sk(sk)->inet_num = IPPROTO_L2TP; | |
230 | ||
231 | write_lock_bh(&l2tp_ip6_lock); | |
232 | sk_add_node(sk, &l2tp_ip6_table); | |
233 | write_unlock_bh(&l2tp_ip6_lock); | |
234 | ||
235 | return 0; | |
236 | } | |
237 | ||
238 | static void l2tp_ip6_close(struct sock *sk, long timeout) | |
239 | { | |
240 | write_lock_bh(&l2tp_ip6_lock); | |
241 | hlist_del_init(&sk->sk_bind_node); | |
242 | sk_del_node_init(sk); | |
243 | write_unlock_bh(&l2tp_ip6_lock); | |
244 | ||
245 | sk_common_release(sk); | |
246 | } | |
247 | ||
248 | static void l2tp_ip6_destroy_sock(struct sock *sk) | |
249 | { | |
93606317 TP |
250 | struct l2tp_tunnel *tunnel = l2tp_sock_to_tunnel(sk); |
251 | ||
a32e0eec CE |
252 | lock_sock(sk); |
253 | ip6_flush_pending_frames(sk); | |
254 | release_sock(sk); | |
255 | ||
93606317 TP |
256 | if (tunnel) { |
257 | l2tp_tunnel_closeall(tunnel); | |
258 | sock_put(sk); | |
259 | } | |
260 | ||
a32e0eec CE |
261 | inet6_destroy_sock(sk); |
262 | } | |
263 | ||
264 | static int l2tp_ip6_bind(struct sock *sk, struct sockaddr *uaddr, int addr_len) | |
265 | { | |
266 | struct inet_sock *inet = inet_sk(sk); | |
267 | struct ipv6_pinfo *np = inet6_sk(sk); | |
268 | struct sockaddr_l2tpip6 *addr = (struct sockaddr_l2tpip6 *) uaddr; | |
0e6b5259 | 269 | struct net *net = sock_net(sk); |
a32e0eec | 270 | __be32 v4addr = 0; |
d5e3a190 | 271 | int bound_dev_if; |
a32e0eec CE |
272 | int addr_type; |
273 | int err; | |
274 | ||
c51ce497 JC |
275 | if (addr->l2tp_family != AF_INET6) |
276 | return -EINVAL; | |
a32e0eec CE |
277 | if (addr_len < sizeof(*addr)) |
278 | return -EINVAL; | |
279 | ||
280 | addr_type = ipv6_addr_type(&addr->l2tp_addr); | |
281 | ||
282 | /* l2tp_ip6 sockets are IPv6 only */ | |
283 | if (addr_type == IPV6_ADDR_MAPPED) | |
284 | return -EADDRNOTAVAIL; | |
285 | ||
286 | /* L2TP is point-point, not multicast */ | |
287 | if (addr_type & IPV6_ADDR_MULTICAST) | |
288 | return -EADDRNOTAVAIL; | |
289 | ||
a32e0eec CE |
290 | lock_sock(sk); |
291 | ||
292 | err = -EINVAL; | |
32c23116 GN |
293 | if (!sock_flag(sk, SOCK_ZAPPED)) |
294 | goto out_unlock; | |
295 | ||
a32e0eec CE |
296 | if (sk->sk_state != TCP_CLOSE) |
297 | goto out_unlock; | |
298 | ||
d5e3a190 GN |
299 | bound_dev_if = sk->sk_bound_dev_if; |
300 | ||
a32e0eec CE |
301 | /* Check if the address belongs to the host. */ |
302 | rcu_read_lock(); | |
303 | if (addr_type != IPV6_ADDR_ANY) { | |
304 | struct net_device *dev = NULL; | |
305 | ||
306 | if (addr_type & IPV6_ADDR_LINKLOCAL) { | |
d5e3a190 GN |
307 | if (addr->l2tp_scope_id) |
308 | bound_dev_if = addr->l2tp_scope_id; | |
a32e0eec CE |
309 | |
310 | /* Binding to link-local address requires an | |
d5e3a190 GN |
311 | * interface. |
312 | */ | |
313 | if (!bound_dev_if) | |
a32e0eec CE |
314 | goto out_unlock_rcu; |
315 | ||
316 | err = -ENODEV; | |
d5e3a190 | 317 | dev = dev_get_by_index_rcu(sock_net(sk), bound_dev_if); |
a32e0eec CE |
318 | if (!dev) |
319 | goto out_unlock_rcu; | |
320 | } | |
321 | ||
322 | /* ipv4 addr of the socket is invalid. Only the | |
323 | * unspecified and mapped address have a v4 equivalent. | |
324 | */ | |
325 | v4addr = LOOPBACK4_IPV6; | |
326 | err = -EADDRNOTAVAIL; | |
327 | if (!ipv6_chk_addr(sock_net(sk), &addr->l2tp_addr, dev, 0)) | |
328 | goto out_unlock_rcu; | |
329 | } | |
330 | rcu_read_unlock(); | |
331 | ||
d5e3a190 | 332 | write_lock_bh(&l2tp_ip6_lock); |
a9b2dff8 | 333 | if (__l2tp_ip6_bind_lookup(net, &addr->l2tp_addr, NULL, bound_dev_if, |
d5e3a190 GN |
334 | addr->l2tp_conn_id)) { |
335 | write_unlock_bh(&l2tp_ip6_lock); | |
336 | err = -EADDRINUSE; | |
337 | goto out_unlock; | |
338 | } | |
339 | ||
340 | inet->inet_saddr = v4addr; | |
341 | inet->inet_rcv_saddr = v4addr; | |
342 | sk->sk_bound_dev_if = bound_dev_if; | |
efe4208f | 343 | sk->sk_v6_rcv_saddr = addr->l2tp_addr; |
a32e0eec CE |
344 | np->saddr = addr->l2tp_addr; |
345 | ||
346 | l2tp_ip6_sk(sk)->conn_id = addr->l2tp_conn_id; | |
347 | ||
a32e0eec CE |
348 | sk_add_bind_node(sk, &l2tp_ip6_bind_table); |
349 | sk_del_node_init(sk); | |
350 | write_unlock_bh(&l2tp_ip6_lock); | |
351 | ||
c51ce497 | 352 | sock_reset_flag(sk, SOCK_ZAPPED); |
a32e0eec CE |
353 | release_sock(sk); |
354 | return 0; | |
355 | ||
356 | out_unlock_rcu: | |
357 | rcu_read_unlock(); | |
358 | out_unlock: | |
359 | release_sock(sk); | |
a32e0eec | 360 | |
a32e0eec CE |
361 | return err; |
362 | } | |
363 | ||
364 | static 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 | ||
373 | if (addr_len < sizeof(*lsa)) | |
374 | return -EINVAL; | |
375 | ||
82b276cd HFS |
376 | if (usin->sin6_family != AF_INET6) |
377 | return -EINVAL; | |
378 | ||
a32e0eec CE |
379 | addr_type = ipv6_addr_type(&usin->sin6_addr); |
380 | if (addr_type & IPV6_ADDR_MULTICAST) | |
381 | return -EINVAL; | |
382 | ||
383 | if (addr_type & IPV6_ADDR_MAPPED) { | |
384 | daddr = &usin->sin6_addr; | |
385 | if (ipv4_is_multicast(daddr->s6_addr32[3])) | |
386 | return -EINVAL; | |
387 | } | |
388 | ||
a32e0eec CE |
389 | lock_sock(sk); |
390 | ||
0382a25a GN |
391 | /* Must bind first - autobinding does not work */ |
392 | if (sock_flag(sk, SOCK_ZAPPED)) { | |
393 | rc = -EINVAL; | |
394 | goto out_sk; | |
395 | } | |
396 | ||
397 | rc = __ip6_datagram_connect(sk, uaddr, addr_len); | |
398 | if (rc < 0) | |
399 | goto out_sk; | |
400 | ||
a32e0eec CE |
401 | l2tp_ip6_sk(sk)->peer_conn_id = lsa->l2tp_conn_id; |
402 | ||
403 | write_lock_bh(&l2tp_ip6_lock); | |
404 | hlist_del_init(&sk->sk_bind_node); | |
405 | sk_add_bind_node(sk, &l2tp_ip6_bind_table); | |
406 | write_unlock_bh(&l2tp_ip6_lock); | |
407 | ||
0382a25a | 408 | out_sk: |
a32e0eec CE |
409 | release_sock(sk); |
410 | ||
411 | return rc; | |
412 | } | |
413 | ||
c51ce497 JC |
414 | static int l2tp_ip6_disconnect(struct sock *sk, int flags) |
415 | { | |
416 | if (sock_flag(sk, SOCK_ZAPPED)) | |
417 | return 0; | |
418 | ||
286c72de | 419 | return __udp_disconnect(sk, flags); |
c51ce497 JC |
420 | } |
421 | ||
a32e0eec CE |
422 | static int l2tp_ip6_getname(struct socket *sock, struct sockaddr *uaddr, |
423 | int *uaddr_len, int peer) | |
424 | { | |
425 | struct sockaddr_l2tpip6 *lsa = (struct sockaddr_l2tpip6 *)uaddr; | |
426 | struct sock *sk = sock->sk; | |
427 | struct ipv6_pinfo *np = inet6_sk(sk); | |
428 | struct l2tp_ip6_sock *lsk = l2tp_ip6_sk(sk); | |
429 | ||
430 | lsa->l2tp_family = AF_INET6; | |
431 | lsa->l2tp_flowinfo = 0; | |
432 | lsa->l2tp_scope_id = 0; | |
04d4fbca | 433 | lsa->l2tp_unused = 0; |
a32e0eec CE |
434 | if (peer) { |
435 | if (!lsk->peer_conn_id) | |
436 | return -ENOTCONN; | |
437 | lsa->l2tp_conn_id = lsk->peer_conn_id; | |
efe4208f | 438 | lsa->l2tp_addr = sk->sk_v6_daddr; |
a32e0eec CE |
439 | if (np->sndflow) |
440 | lsa->l2tp_flowinfo = np->flow_label; | |
441 | } else { | |
efe4208f | 442 | if (ipv6_addr_any(&sk->sk_v6_rcv_saddr)) |
a32e0eec CE |
443 | lsa->l2tp_addr = np->saddr; |
444 | else | |
efe4208f | 445 | lsa->l2tp_addr = sk->sk_v6_rcv_saddr; |
a32e0eec CE |
446 | |
447 | lsa->l2tp_conn_id = lsk->conn_id; | |
448 | } | |
449 | if (ipv6_addr_type(&lsa->l2tp_addr) & IPV6_ADDR_LINKLOCAL) | |
450 | lsa->l2tp_scope_id = sk->sk_bound_dev_if; | |
451 | *uaddr_len = sizeof(*lsa); | |
452 | return 0; | |
453 | } | |
454 | ||
455 | static int l2tp_ip6_backlog_recv(struct sock *sk, struct sk_buff *skb) | |
456 | { | |
457 | int rc; | |
458 | ||
459 | /* Charge it to the socket, dropping if the queue is full. */ | |
460 | rc = sock_queue_rcv_skb(sk, skb); | |
461 | if (rc < 0) | |
462 | goto drop; | |
463 | ||
464 | return 0; | |
465 | ||
466 | drop: | |
0e6b5259 | 467 | IP_INC_STATS(sock_net(sk), IPSTATS_MIB_INDISCARDS); |
a32e0eec CE |
468 | kfree_skb(skb); |
469 | return -1; | |
470 | } | |
471 | ||
472 | static int l2tp_ip6_push_pending_frames(struct sock *sk) | |
473 | { | |
474 | struct sk_buff *skb; | |
475 | __be32 *transhdr = NULL; | |
476 | int err = 0; | |
477 | ||
478 | skb = skb_peek(&sk->sk_write_queue); | |
479 | if (skb == NULL) | |
480 | goto out; | |
481 | ||
482 | transhdr = (__be32 *)skb_transport_header(skb); | |
483 | *transhdr = 0; | |
484 | ||
485 | err = ip6_push_pending_frames(sk); | |
486 | ||
487 | out: | |
488 | return err; | |
489 | } | |
490 | ||
491 | /* Userspace will call sendmsg() on the tunnel socket to send L2TP | |
492 | * control frames. | |
493 | */ | |
1b784140 | 494 | static int l2tp_ip6_sendmsg(struct sock *sk, struct msghdr *msg, size_t len) |
a32e0eec CE |
495 | { |
496 | struct ipv6_txoptions opt_space; | |
342dfc30 | 497 | DECLARE_SOCKADDR(struct sockaddr_l2tpip6 *, lsa, msg->msg_name); |
a32e0eec CE |
498 | struct in6_addr *daddr, *final_p, final; |
499 | struct ipv6_pinfo *np = inet6_sk(sk); | |
45f6fad8 | 500 | struct ipv6_txoptions *opt_to_free = NULL; |
a32e0eec CE |
501 | struct ipv6_txoptions *opt = NULL; |
502 | struct ip6_flowlabel *flowlabel = NULL; | |
503 | struct dst_entry *dst = NULL; | |
504 | struct flowi6 fl6; | |
ad1e46a8 | 505 | struct sockcm_cookie sockc_unused = {0}; |
26879da5 | 506 | struct ipcm6_cookie ipc6; |
a32e0eec | 507 | int addr_len = msg->msg_namelen; |
a32e0eec CE |
508 | int transhdrlen = 4; /* zero session-id */ |
509 | int ulen = len + transhdrlen; | |
510 | int err; | |
511 | ||
512 | /* Rough check on arithmetic overflow, | |
513 | better check is made in ip6_append_data(). | |
514 | */ | |
515 | if (len > INT_MAX) | |
516 | return -EMSGSIZE; | |
517 | ||
518 | /* Mirror BSD error message compatibility */ | |
519 | if (msg->msg_flags & MSG_OOB) | |
520 | return -EOPNOTSUPP; | |
521 | ||
522 | /* | |
523 | * Get and verify the address. | |
524 | */ | |
525 | memset(&fl6, 0, sizeof(fl6)); | |
526 | ||
527 | fl6.flowi6_mark = sk->sk_mark; | |
e2d118a1 | 528 | fl6.flowi6_uid = sk->sk_uid; |
a32e0eec | 529 | |
26879da5 WW |
530 | ipc6.hlimit = -1; |
531 | ipc6.tclass = -1; | |
532 | ipc6.dontfrag = -1; | |
533 | ||
a32e0eec CE |
534 | if (lsa) { |
535 | if (addr_len < SIN6_LEN_RFC2133) | |
536 | return -EINVAL; | |
537 | ||
538 | if (lsa->l2tp_family && lsa->l2tp_family != AF_INET6) | |
539 | return -EAFNOSUPPORT; | |
540 | ||
541 | daddr = &lsa->l2tp_addr; | |
542 | if (np->sndflow) { | |
543 | fl6.flowlabel = lsa->l2tp_flowinfo & IPV6_FLOWINFO_MASK; | |
544 | if (fl6.flowlabel&IPV6_FLOWLABEL_MASK) { | |
545 | flowlabel = fl6_sock_lookup(sk, fl6.flowlabel); | |
546 | if (flowlabel == NULL) | |
547 | return -EINVAL; | |
a32e0eec CE |
548 | } |
549 | } | |
550 | ||
551 | /* | |
552 | * Otherwise it will be difficult to maintain | |
553 | * sk->sk_dst_cache. | |
554 | */ | |
555 | if (sk->sk_state == TCP_ESTABLISHED && | |
efe4208f ED |
556 | ipv6_addr_equal(daddr, &sk->sk_v6_daddr)) |
557 | daddr = &sk->sk_v6_daddr; | |
a32e0eec CE |
558 | |
559 | if (addr_len >= sizeof(struct sockaddr_in6) && | |
560 | lsa->l2tp_scope_id && | |
561 | ipv6_addr_type(daddr) & IPV6_ADDR_LINKLOCAL) | |
562 | fl6.flowi6_oif = lsa->l2tp_scope_id; | |
563 | } else { | |
564 | if (sk->sk_state != TCP_ESTABLISHED) | |
565 | return -EDESTADDRREQ; | |
566 | ||
efe4208f | 567 | daddr = &sk->sk_v6_daddr; |
a32e0eec CE |
568 | fl6.flowlabel = np->flow_label; |
569 | } | |
570 | ||
571 | if (fl6.flowi6_oif == 0) | |
572 | fl6.flowi6_oif = sk->sk_bound_dev_if; | |
573 | ||
574 | if (msg->msg_controllen) { | |
575 | opt = &opt_space; | |
576 | memset(opt, 0, sizeof(struct ipv6_txoptions)); | |
577 | opt->tot_len = sizeof(struct ipv6_txoptions); | |
26879da5 | 578 | ipc6.opt = opt; |
a32e0eec | 579 | |
26879da5 WW |
580 | err = ip6_datagram_send_ctl(sock_net(sk), sk, msg, &fl6, &ipc6, |
581 | &sockc_unused); | |
582 | if (err < 0) { | |
a32e0eec CE |
583 | fl6_sock_release(flowlabel); |
584 | return err; | |
585 | } | |
586 | if ((fl6.flowlabel & IPV6_FLOWLABEL_MASK) && !flowlabel) { | |
587 | flowlabel = fl6_sock_lookup(sk, fl6.flowlabel); | |
588 | if (flowlabel == NULL) | |
589 | return -EINVAL; | |
590 | } | |
591 | if (!(opt->opt_nflen|opt->opt_flen)) | |
592 | opt = NULL; | |
593 | } | |
594 | ||
45f6fad8 ED |
595 | if (!opt) { |
596 | opt = txopt_get(np); | |
597 | opt_to_free = opt; | |
598 | } | |
a32e0eec CE |
599 | if (flowlabel) |
600 | opt = fl6_merge_options(&opt_space, flowlabel, opt); | |
601 | opt = ipv6_fixup_options(&opt_space, opt); | |
26879da5 | 602 | ipc6.opt = opt; |
a32e0eec CE |
603 | |
604 | fl6.flowi6_proto = sk->sk_protocol; | |
605 | if (!ipv6_addr_any(daddr)) | |
606 | fl6.daddr = *daddr; | |
607 | else | |
608 | fl6.daddr.s6_addr[15] = 0x1; /* :: means loopback (BSD'ism) */ | |
609 | if (ipv6_addr_any(&fl6.saddr) && !ipv6_addr_any(&np->saddr)) | |
610 | fl6.saddr = np->saddr; | |
611 | ||
612 | final_p = fl6_update_dst(&fl6, opt, &final); | |
613 | ||
614 | if (!fl6.flowi6_oif && ipv6_addr_is_multicast(&fl6.daddr)) | |
615 | fl6.flowi6_oif = np->mcast_oif; | |
616 | else if (!fl6.flowi6_oif) | |
617 | fl6.flowi6_oif = np->ucast_oif; | |
618 | ||
619 | security_sk_classify_flow(sk, flowi6_to_flowi(&fl6)); | |
620 | ||
38b7097b HFS |
621 | if (ipc6.tclass < 0) |
622 | ipc6.tclass = np->tclass; | |
623 | ||
624 | fl6.flowlabel = ip6_make_flowinfo(ipc6.tclass, fl6.flowlabel); | |
625 | ||
0e0d44ab | 626 | dst = ip6_dst_lookup_flow(sk, &fl6, final_p); |
a32e0eec CE |
627 | if (IS_ERR(dst)) { |
628 | err = PTR_ERR(dst); | |
629 | goto out; | |
630 | } | |
631 | ||
26879da5 WW |
632 | if (ipc6.hlimit < 0) |
633 | ipc6.hlimit = ip6_sk_dst_hoplimit(np, &fl6, dst); | |
a32e0eec | 634 | |
26879da5 WW |
635 | if (ipc6.dontfrag < 0) |
636 | ipc6.dontfrag = np->dontfrag; | |
a32e0eec CE |
637 | |
638 | if (msg->msg_flags & MSG_CONFIRM) | |
639 | goto do_confirm; | |
640 | ||
641 | back_from_confirm: | |
642 | lock_sock(sk); | |
f69e6d13 | 643 | err = ip6_append_data(sk, ip_generic_getfrag, msg, |
26879da5 | 644 | ulen, transhdrlen, &ipc6, |
a32e0eec | 645 | &fl6, (struct rt6_info *)dst, |
26879da5 | 646 | msg->msg_flags, &sockc_unused); |
a32e0eec CE |
647 | if (err) |
648 | ip6_flush_pending_frames(sk); | |
649 | else if (!(msg->msg_flags & MSG_MORE)) | |
650 | err = l2tp_ip6_push_pending_frames(sk); | |
651 | release_sock(sk); | |
652 | done: | |
653 | dst_release(dst); | |
654 | out: | |
655 | fl6_sock_release(flowlabel); | |
45f6fad8 | 656 | txopt_put(opt_to_free); |
a32e0eec CE |
657 | |
658 | return err < 0 ? err : len; | |
659 | ||
660 | do_confirm: | |
661 | dst_confirm(dst); | |
662 | if (!(msg->msg_flags & MSG_PROBE) || len) | |
663 | goto back_from_confirm; | |
664 | err = 0; | |
665 | goto done; | |
666 | } | |
667 | ||
1b784140 YX |
668 | static int l2tp_ip6_recvmsg(struct sock *sk, struct msghdr *msg, size_t len, |
669 | int noblock, int flags, int *addr_len) | |
a32e0eec | 670 | { |
700163db | 671 | struct ipv6_pinfo *np = inet6_sk(sk); |
342dfc30 | 672 | DECLARE_SOCKADDR(struct sockaddr_l2tpip6 *, lsa, msg->msg_name); |
a32e0eec CE |
673 | size_t copied = 0; |
674 | int err = -EOPNOTSUPP; | |
675 | struct sk_buff *skb; | |
676 | ||
677 | if (flags & MSG_OOB) | |
678 | goto out; | |
679 | ||
680 | if (addr_len) | |
681 | *addr_len = sizeof(*lsa); | |
682 | ||
683 | if (flags & MSG_ERRQUEUE) | |
85fbaa75 | 684 | return ipv6_recv_error(sk, msg, len, addr_len); |
a32e0eec CE |
685 | |
686 | skb = skb_recv_datagram(sk, flags, noblock, &err); | |
687 | if (!skb) | |
688 | goto out; | |
689 | ||
690 | copied = skb->len; | |
691 | if (len < copied) { | |
692 | msg->msg_flags |= MSG_TRUNC; | |
693 | copied = len; | |
694 | } | |
695 | ||
51f3d02b | 696 | err = skb_copy_datagram_msg(skb, 0, msg, copied); |
a32e0eec CE |
697 | if (err) |
698 | goto done; | |
699 | ||
700 | sock_recv_timestamp(msg, sk, skb); | |
701 | ||
702 | /* Copy the address. */ | |
703 | if (lsa) { | |
704 | lsa->l2tp_family = AF_INET6; | |
705 | lsa->l2tp_unused = 0; | |
706 | lsa->l2tp_addr = ipv6_hdr(skb)->saddr; | |
707 | lsa->l2tp_flowinfo = 0; | |
708 | lsa->l2tp_scope_id = 0; | |
b860d3cc | 709 | lsa->l2tp_conn_id = 0; |
a32e0eec | 710 | if (ipv6_addr_type(&lsa->l2tp_addr) & IPV6_ADDR_LINKLOCAL) |
4330487a | 711 | lsa->l2tp_scope_id = inet6_iif(skb); |
a32e0eec CE |
712 | } |
713 | ||
700163db TP |
714 | if (np->rxopt.all) |
715 | ip6_datagram_recv_ctl(sk, msg, skb); | |
a32e0eec CE |
716 | |
717 | if (flags & MSG_TRUNC) | |
718 | copied = skb->len; | |
719 | done: | |
720 | skb_free_datagram(sk, skb); | |
721 | out: | |
722 | return err ? err : copied; | |
723 | } | |
724 | ||
725 | static struct proto l2tp_ip6_prot = { | |
726 | .name = "L2TP/IPv6", | |
727 | .owner = THIS_MODULE, | |
728 | .init = l2tp_ip6_open, | |
729 | .close = l2tp_ip6_close, | |
730 | .bind = l2tp_ip6_bind, | |
731 | .connect = l2tp_ip6_connect, | |
c51ce497 | 732 | .disconnect = l2tp_ip6_disconnect, |
a32e0eec CE |
733 | .ioctl = udp_ioctl, |
734 | .destroy = l2tp_ip6_destroy_sock, | |
735 | .setsockopt = ipv6_setsockopt, | |
736 | .getsockopt = ipv6_getsockopt, | |
737 | .sendmsg = l2tp_ip6_sendmsg, | |
738 | .recvmsg = l2tp_ip6_recvmsg, | |
739 | .backlog_rcv = l2tp_ip6_backlog_recv, | |
496611d7 | 740 | .hash = inet6_hash, |
a32e0eec CE |
741 | .unhash = inet_unhash, |
742 | .obj_size = sizeof(struct l2tp_ip6_sock), | |
743 | #ifdef CONFIG_COMPAT | |
744 | .compat_setsockopt = compat_ipv6_setsockopt, | |
745 | .compat_getsockopt = compat_ipv6_getsockopt, | |
746 | #endif | |
747 | }; | |
748 | ||
749 | static const struct proto_ops l2tp_ip6_ops = { | |
750 | .family = PF_INET6, | |
751 | .owner = THIS_MODULE, | |
752 | .release = inet6_release, | |
753 | .bind = inet6_bind, | |
754 | .connect = inet_dgram_connect, | |
755 | .socketpair = sock_no_socketpair, | |
756 | .accept = sock_no_accept, | |
757 | .getname = l2tp_ip6_getname, | |
758 | .poll = datagram_poll, | |
759 | .ioctl = inet6_ioctl, | |
760 | .listen = sock_no_listen, | |
761 | .shutdown = inet_shutdown, | |
762 | .setsockopt = sock_common_setsockopt, | |
763 | .getsockopt = sock_common_getsockopt, | |
764 | .sendmsg = inet_sendmsg, | |
765 | .recvmsg = sock_common_recvmsg, | |
766 | .mmap = sock_no_mmap, | |
767 | .sendpage = sock_no_sendpage, | |
768 | #ifdef CONFIG_COMPAT | |
769 | .compat_setsockopt = compat_sock_common_setsockopt, | |
770 | .compat_getsockopt = compat_sock_common_getsockopt, | |
771 | #endif | |
772 | }; | |
773 | ||
774 | static struct inet_protosw l2tp_ip6_protosw = { | |
775 | .type = SOCK_DGRAM, | |
776 | .protocol = IPPROTO_L2TP, | |
777 | .prot = &l2tp_ip6_prot, | |
778 | .ops = &l2tp_ip6_ops, | |
a32e0eec CE |
779 | }; |
780 | ||
781 | static struct inet6_protocol l2tp_ip6_protocol __read_mostly = { | |
782 | .handler = l2tp_ip6_recv, | |
783 | }; | |
784 | ||
785 | static int __init l2tp_ip6_init(void) | |
786 | { | |
787 | int err; | |
788 | ||
a4ca44fa | 789 | pr_info("L2TP IP encapsulation support for IPv6 (L2TPv3)\n"); |
a32e0eec CE |
790 | |
791 | err = proto_register(&l2tp_ip6_prot, 1); | |
792 | if (err != 0) | |
793 | goto out; | |
794 | ||
795 | err = inet6_add_protocol(&l2tp_ip6_protocol, IPPROTO_L2TP); | |
796 | if (err) | |
797 | goto out1; | |
798 | ||
799 | inet6_register_protosw(&l2tp_ip6_protosw); | |
800 | return 0; | |
801 | ||
802 | out1: | |
803 | proto_unregister(&l2tp_ip6_prot); | |
804 | out: | |
805 | return err; | |
806 | } | |
807 | ||
808 | static void __exit l2tp_ip6_exit(void) | |
809 | { | |
810 | inet6_unregister_protosw(&l2tp_ip6_protosw); | |
811 | inet6_del_protocol(&l2tp_ip6_protocol, IPPROTO_L2TP); | |
812 | proto_unregister(&l2tp_ip6_prot); | |
813 | } | |
814 | ||
815 | module_init(l2tp_ip6_init); | |
816 | module_exit(l2tp_ip6_exit); | |
817 | ||
818 | MODULE_LICENSE("GPL"); | |
819 | MODULE_AUTHOR("Chris Elston <celston@katalix.com>"); | |
820 | MODULE_DESCRIPTION("L2TP IP encapsulation for IPv6"); | |
821 | MODULE_VERSION("1.0"); | |
822 | ||
823 | /* Use the value of SOCK_DGRAM (2) directory, because __stringify doesn't like | |
824 | * enums | |
825 | */ | |
826 | MODULE_ALIAS_NET_PF_PROTO_TYPE(PF_INET6, 2, IPPROTO_L2TP); | |
163c2e25 | 827 | MODULE_ALIAS_NET_PF_PROTO(PF_INET6, IPPROTO_L2TP); |