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Commit | Line | Data |
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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; | |
8f7dc9ae | 139 | struct ipv6hdr *iph; |
a32e0eec | 140 | int length; |
a32e0eec | 141 | |
a32e0eec CE |
142 | if (!pskb_may_pull(skb, 4)) |
143 | goto discard; | |
144 | ||
be447f30 HY |
145 | /* Point to L2TP header */ |
146 | optr = ptr = skb->data; | |
a32e0eec CE |
147 | session_id = ntohl(*((__be32 *) ptr)); |
148 | ptr += 4; | |
149 | ||
150 | /* RFC3931: L2TP/IP packets have the first 4 bytes containing | |
151 | * the session_id. If it is 0, the packet is a L2TP control | |
152 | * frame and the session_id value can be discarded. | |
153 | */ | |
154 | if (session_id == 0) { | |
155 | __skb_pull(skb, 4); | |
156 | goto pass_up; | |
157 | } | |
158 | ||
159 | /* Ok, this is a data packet. Lookup the session. */ | |
a4346210 | 160 | session = l2tp_session_get(net, NULL, session_id); |
61b9a047 | 161 | if (!session) |
a32e0eec CE |
162 | goto discard; |
163 | ||
164 | tunnel = session->tunnel; | |
61b9a047 GN |
165 | if (!tunnel) |
166 | goto discard_sess; | |
a32e0eec CE |
167 | |
168 | /* Trace packet contents, if enabled */ | |
169 | if (tunnel->debug & L2TP_MSG_DATA) { | |
170 | length = min(32u, skb->len); | |
171 | if (!pskb_may_pull(skb, length)) | |
61b9a047 | 172 | goto discard_sess; |
a32e0eec | 173 | |
be447f30 HY |
174 | /* Point to L2TP header */ |
175 | optr = ptr = skb->data; | |
176 | ptr += 4; | |
a4ca44fa JP |
177 | pr_debug("%s: ip recv\n", tunnel->name); |
178 | print_hex_dump_bytes("", DUMP_PREFIX_OFFSET, ptr, length); | |
a32e0eec CE |
179 | } |
180 | ||
1f18aadf JW |
181 | if (l2tp_v3_ensure_opt_in_linear(session, skb, &ptr, &optr)) |
182 | goto discard_sess; | |
183 | ||
a32e0eec CE |
184 | l2tp_recv_common(session, skb, ptr, optr, 0, skb->len, |
185 | tunnel->recv_payload_hook); | |
61b9a047 GN |
186 | l2tp_session_dec_refcount(session); |
187 | ||
a32e0eec CE |
188 | return 0; |
189 | ||
190 | pass_up: | |
191 | /* Get the tunnel_id from the L2TP header */ | |
192 | if (!pskb_may_pull(skb, 12)) | |
193 | goto discard; | |
194 | ||
195 | if ((skb->data[0] & 0xc0) != 0xc0) | |
196 | goto discard; | |
197 | ||
198 | tunnel_id = ntohl(*(__be32 *) &skb->data[4]); | |
8f7dc9ae GN |
199 | iph = ipv6_hdr(skb); |
200 | ||
201 | read_lock_bh(&l2tp_ip6_lock); | |
202 | sk = __l2tp_ip6_bind_lookup(net, &iph->daddr, &iph->saddr, | |
203 | inet6_iif(skb), tunnel_id); | |
204 | if (!sk) { | |
a32e0eec | 205 | read_unlock_bh(&l2tp_ip6_lock); |
8f7dc9ae | 206 | goto discard; |
a32e0eec | 207 | } |
8f7dc9ae GN |
208 | sock_hold(sk); |
209 | read_unlock_bh(&l2tp_ip6_lock); | |
a32e0eec | 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 | ||
61b9a047 | 218 | discard_sess: |
61b9a047 GN |
219 | l2tp_session_dec_refcount(session); |
220 | goto discard; | |
221 | ||
a32e0eec CE |
222 | discard_put: |
223 | sock_put(sk); | |
224 | ||
225 | discard: | |
226 | kfree_skb(skb); | |
227 | return 0; | |
228 | } | |
229 | ||
230 | static int l2tp_ip6_open(struct sock *sk) | |
231 | { | |
232 | /* Prevent autobind. We don't have ports. */ | |
233 | inet_sk(sk)->inet_num = IPPROTO_L2TP; | |
234 | ||
235 | write_lock_bh(&l2tp_ip6_lock); | |
236 | sk_add_node(sk, &l2tp_ip6_table); | |
237 | write_unlock_bh(&l2tp_ip6_lock); | |
238 | ||
239 | return 0; | |
240 | } | |
241 | ||
242 | static void l2tp_ip6_close(struct sock *sk, long timeout) | |
243 | { | |
244 | write_lock_bh(&l2tp_ip6_lock); | |
245 | hlist_del_init(&sk->sk_bind_node); | |
246 | sk_del_node_init(sk); | |
247 | write_unlock_bh(&l2tp_ip6_lock); | |
248 | ||
249 | sk_common_release(sk); | |
250 | } | |
251 | ||
252 | static void l2tp_ip6_destroy_sock(struct sock *sk) | |
253 | { | |
02a25fee | 254 | struct l2tp_tunnel *tunnel = sk->sk_user_data; |
93606317 | 255 | |
a32e0eec CE |
256 | lock_sock(sk); |
257 | ip6_flush_pending_frames(sk); | |
258 | release_sock(sk); | |
259 | ||
02a25fee JC |
260 | if (tunnel) |
261 | l2tp_tunnel_delete(tunnel); | |
93606317 | 262 | |
a32e0eec CE |
263 | inet6_destroy_sock(sk); |
264 | } | |
265 | ||
266 | static int l2tp_ip6_bind(struct sock *sk, struct sockaddr *uaddr, int addr_len) | |
267 | { | |
268 | struct inet_sock *inet = inet_sk(sk); | |
269 | struct ipv6_pinfo *np = inet6_sk(sk); | |
270 | struct sockaddr_l2tpip6 *addr = (struct sockaddr_l2tpip6 *) uaddr; | |
0e6b5259 | 271 | struct net *net = sock_net(sk); |
a32e0eec | 272 | __be32 v4addr = 0; |
d5e3a190 | 273 | int bound_dev_if; |
a32e0eec CE |
274 | int addr_type; |
275 | int err; | |
276 | ||
c51ce497 JC |
277 | if (addr->l2tp_family != AF_INET6) |
278 | return -EINVAL; | |
a32e0eec CE |
279 | if (addr_len < sizeof(*addr)) |
280 | return -EINVAL; | |
281 | ||
282 | addr_type = ipv6_addr_type(&addr->l2tp_addr); | |
283 | ||
284 | /* l2tp_ip6 sockets are IPv6 only */ | |
285 | if (addr_type == IPV6_ADDR_MAPPED) | |
286 | return -EADDRNOTAVAIL; | |
287 | ||
288 | /* L2TP is point-point, not multicast */ | |
289 | if (addr_type & IPV6_ADDR_MULTICAST) | |
290 | return -EADDRNOTAVAIL; | |
291 | ||
a32e0eec CE |
292 | lock_sock(sk); |
293 | ||
294 | err = -EINVAL; | |
32c23116 GN |
295 | if (!sock_flag(sk, SOCK_ZAPPED)) |
296 | goto out_unlock; | |
297 | ||
a32e0eec CE |
298 | if (sk->sk_state != TCP_CLOSE) |
299 | goto out_unlock; | |
300 | ||
d5e3a190 GN |
301 | bound_dev_if = sk->sk_bound_dev_if; |
302 | ||
a32e0eec CE |
303 | /* Check if the address belongs to the host. */ |
304 | rcu_read_lock(); | |
305 | if (addr_type != IPV6_ADDR_ANY) { | |
306 | struct net_device *dev = NULL; | |
307 | ||
308 | if (addr_type & IPV6_ADDR_LINKLOCAL) { | |
d5e3a190 GN |
309 | if (addr->l2tp_scope_id) |
310 | bound_dev_if = addr->l2tp_scope_id; | |
a32e0eec CE |
311 | |
312 | /* Binding to link-local address requires an | |
d5e3a190 GN |
313 | * interface. |
314 | */ | |
315 | if (!bound_dev_if) | |
a32e0eec CE |
316 | goto out_unlock_rcu; |
317 | ||
318 | err = -ENODEV; | |
d5e3a190 | 319 | dev = dev_get_by_index_rcu(sock_net(sk), bound_dev_if); |
a32e0eec CE |
320 | if (!dev) |
321 | goto out_unlock_rcu; | |
322 | } | |
323 | ||
324 | /* ipv4 addr of the socket is invalid. Only the | |
325 | * unspecified and mapped address have a v4 equivalent. | |
326 | */ | |
327 | v4addr = LOOPBACK4_IPV6; | |
328 | err = -EADDRNOTAVAIL; | |
329 | if (!ipv6_chk_addr(sock_net(sk), &addr->l2tp_addr, dev, 0)) | |
330 | goto out_unlock_rcu; | |
331 | } | |
332 | rcu_read_unlock(); | |
333 | ||
d5e3a190 | 334 | write_lock_bh(&l2tp_ip6_lock); |
a9b2dff8 | 335 | if (__l2tp_ip6_bind_lookup(net, &addr->l2tp_addr, NULL, bound_dev_if, |
d5e3a190 GN |
336 | addr->l2tp_conn_id)) { |
337 | write_unlock_bh(&l2tp_ip6_lock); | |
338 | err = -EADDRINUSE; | |
339 | goto out_unlock; | |
340 | } | |
341 | ||
342 | inet->inet_saddr = v4addr; | |
343 | inet->inet_rcv_saddr = v4addr; | |
344 | sk->sk_bound_dev_if = bound_dev_if; | |
efe4208f | 345 | sk->sk_v6_rcv_saddr = addr->l2tp_addr; |
a32e0eec CE |
346 | np->saddr = addr->l2tp_addr; |
347 | ||
348 | l2tp_ip6_sk(sk)->conn_id = addr->l2tp_conn_id; | |
349 | ||
a32e0eec CE |
350 | sk_add_bind_node(sk, &l2tp_ip6_bind_table); |
351 | sk_del_node_init(sk); | |
352 | write_unlock_bh(&l2tp_ip6_lock); | |
353 | ||
c51ce497 | 354 | sock_reset_flag(sk, SOCK_ZAPPED); |
a32e0eec CE |
355 | release_sock(sk); |
356 | return 0; | |
357 | ||
358 | out_unlock_rcu: | |
359 | rcu_read_unlock(); | |
360 | out_unlock: | |
361 | release_sock(sk); | |
a32e0eec | 362 | |
a32e0eec CE |
363 | return err; |
364 | } | |
365 | ||
366 | static int l2tp_ip6_connect(struct sock *sk, struct sockaddr *uaddr, | |
367 | int addr_len) | |
368 | { | |
369 | struct sockaddr_l2tpip6 *lsa = (struct sockaddr_l2tpip6 *) uaddr; | |
370 | struct sockaddr_in6 *usin = (struct sockaddr_in6 *) uaddr; | |
371 | struct in6_addr *daddr; | |
372 | int addr_type; | |
373 | int rc; | |
374 | ||
375 | if (addr_len < sizeof(*lsa)) | |
376 | return -EINVAL; | |
377 | ||
82b276cd HFS |
378 | if (usin->sin6_family != AF_INET6) |
379 | return -EINVAL; | |
380 | ||
a32e0eec CE |
381 | addr_type = ipv6_addr_type(&usin->sin6_addr); |
382 | if (addr_type & IPV6_ADDR_MULTICAST) | |
383 | return -EINVAL; | |
384 | ||
385 | if (addr_type & IPV6_ADDR_MAPPED) { | |
386 | daddr = &usin->sin6_addr; | |
387 | if (ipv4_is_multicast(daddr->s6_addr32[3])) | |
388 | return -EINVAL; | |
389 | } | |
390 | ||
a32e0eec CE |
391 | lock_sock(sk); |
392 | ||
0382a25a GN |
393 | /* Must bind first - autobinding does not work */ |
394 | if (sock_flag(sk, SOCK_ZAPPED)) { | |
395 | rc = -EINVAL; | |
396 | goto out_sk; | |
397 | } | |
398 | ||
399 | rc = __ip6_datagram_connect(sk, uaddr, addr_len); | |
400 | if (rc < 0) | |
401 | goto out_sk; | |
402 | ||
a32e0eec CE |
403 | l2tp_ip6_sk(sk)->peer_conn_id = lsa->l2tp_conn_id; |
404 | ||
405 | write_lock_bh(&l2tp_ip6_lock); | |
406 | hlist_del_init(&sk->sk_bind_node); | |
407 | sk_add_bind_node(sk, &l2tp_ip6_bind_table); | |
408 | write_unlock_bh(&l2tp_ip6_lock); | |
409 | ||
0382a25a | 410 | out_sk: |
a32e0eec CE |
411 | release_sock(sk); |
412 | ||
413 | return rc; | |
414 | } | |
415 | ||
c51ce497 JC |
416 | static int l2tp_ip6_disconnect(struct sock *sk, int flags) |
417 | { | |
418 | if (sock_flag(sk, SOCK_ZAPPED)) | |
419 | return 0; | |
420 | ||
286c72de | 421 | return __udp_disconnect(sk, flags); |
c51ce497 JC |
422 | } |
423 | ||
a32e0eec CE |
424 | static int l2tp_ip6_getname(struct socket *sock, struct sockaddr *uaddr, |
425 | int *uaddr_len, int peer) | |
426 | { | |
427 | struct sockaddr_l2tpip6 *lsa = (struct sockaddr_l2tpip6 *)uaddr; | |
428 | struct sock *sk = sock->sk; | |
429 | struct ipv6_pinfo *np = inet6_sk(sk); | |
430 | struct l2tp_ip6_sock *lsk = l2tp_ip6_sk(sk); | |
431 | ||
432 | lsa->l2tp_family = AF_INET6; | |
433 | lsa->l2tp_flowinfo = 0; | |
434 | lsa->l2tp_scope_id = 0; | |
04d4fbca | 435 | lsa->l2tp_unused = 0; |
a32e0eec CE |
436 | if (peer) { |
437 | if (!lsk->peer_conn_id) | |
438 | return -ENOTCONN; | |
439 | lsa->l2tp_conn_id = lsk->peer_conn_id; | |
efe4208f | 440 | lsa->l2tp_addr = sk->sk_v6_daddr; |
a32e0eec CE |
441 | if (np->sndflow) |
442 | lsa->l2tp_flowinfo = np->flow_label; | |
443 | } else { | |
efe4208f | 444 | if (ipv6_addr_any(&sk->sk_v6_rcv_saddr)) |
a32e0eec CE |
445 | lsa->l2tp_addr = np->saddr; |
446 | else | |
efe4208f | 447 | lsa->l2tp_addr = sk->sk_v6_rcv_saddr; |
a32e0eec CE |
448 | |
449 | lsa->l2tp_conn_id = lsk->conn_id; | |
450 | } | |
451 | if (ipv6_addr_type(&lsa->l2tp_addr) & IPV6_ADDR_LINKLOCAL) | |
452 | lsa->l2tp_scope_id = sk->sk_bound_dev_if; | |
453 | *uaddr_len = sizeof(*lsa); | |
454 | return 0; | |
455 | } | |
456 | ||
457 | static int l2tp_ip6_backlog_recv(struct sock *sk, struct sk_buff *skb) | |
458 | { | |
459 | int rc; | |
460 | ||
461 | /* Charge it to the socket, dropping if the queue is full. */ | |
462 | rc = sock_queue_rcv_skb(sk, skb); | |
463 | if (rc < 0) | |
464 | goto drop; | |
465 | ||
466 | return 0; | |
467 | ||
468 | drop: | |
0e6b5259 | 469 | IP_INC_STATS(sock_net(sk), IPSTATS_MIB_INDISCARDS); |
a32e0eec CE |
470 | kfree_skb(skb); |
471 | return -1; | |
472 | } | |
473 | ||
474 | static int l2tp_ip6_push_pending_frames(struct sock *sk) | |
475 | { | |
476 | struct sk_buff *skb; | |
477 | __be32 *transhdr = NULL; | |
478 | int err = 0; | |
479 | ||
480 | skb = skb_peek(&sk->sk_write_queue); | |
481 | if (skb == NULL) | |
482 | goto out; | |
483 | ||
484 | transhdr = (__be32 *)skb_transport_header(skb); | |
485 | *transhdr = 0; | |
486 | ||
487 | err = ip6_push_pending_frames(sk); | |
488 | ||
489 | out: | |
490 | return err; | |
491 | } | |
492 | ||
493 | /* Userspace will call sendmsg() on the tunnel socket to send L2TP | |
494 | * control frames. | |
495 | */ | |
1b784140 | 496 | static int l2tp_ip6_sendmsg(struct sock *sk, struct msghdr *msg, size_t len) |
a32e0eec CE |
497 | { |
498 | struct ipv6_txoptions opt_space; | |
342dfc30 | 499 | DECLARE_SOCKADDR(struct sockaddr_l2tpip6 *, lsa, msg->msg_name); |
a32e0eec CE |
500 | struct in6_addr *daddr, *final_p, final; |
501 | struct ipv6_pinfo *np = inet6_sk(sk); | |
45f6fad8 | 502 | struct ipv6_txoptions *opt_to_free = NULL; |
a32e0eec CE |
503 | struct ipv6_txoptions *opt = NULL; |
504 | struct ip6_flowlabel *flowlabel = NULL; | |
505 | struct dst_entry *dst = NULL; | |
506 | struct flowi6 fl6; | |
ad1e46a8 | 507 | struct sockcm_cookie sockc_unused = {0}; |
26879da5 | 508 | struct ipcm6_cookie ipc6; |
a32e0eec | 509 | int addr_len = msg->msg_namelen; |
a32e0eec CE |
510 | int transhdrlen = 4; /* zero session-id */ |
511 | int ulen = len + transhdrlen; | |
512 | int err; | |
513 | ||
514 | /* Rough check on arithmetic overflow, | |
515 | better check is made in ip6_append_data(). | |
516 | */ | |
517 | if (len > INT_MAX) | |
518 | return -EMSGSIZE; | |
519 | ||
520 | /* Mirror BSD error message compatibility */ | |
521 | if (msg->msg_flags & MSG_OOB) | |
522 | return -EOPNOTSUPP; | |
523 | ||
524 | /* | |
525 | * Get and verify the address. | |
526 | */ | |
527 | memset(&fl6, 0, sizeof(fl6)); | |
528 | ||
529 | fl6.flowi6_mark = sk->sk_mark; | |
e2d118a1 | 530 | fl6.flowi6_uid = sk->sk_uid; |
a32e0eec | 531 | |
26879da5 WW |
532 | ipc6.hlimit = -1; |
533 | ipc6.tclass = -1; | |
534 | ipc6.dontfrag = -1; | |
535 | ||
a32e0eec CE |
536 | if (lsa) { |
537 | if (addr_len < SIN6_LEN_RFC2133) | |
538 | return -EINVAL; | |
539 | ||
540 | if (lsa->l2tp_family && lsa->l2tp_family != AF_INET6) | |
541 | return -EAFNOSUPPORT; | |
542 | ||
543 | daddr = &lsa->l2tp_addr; | |
544 | if (np->sndflow) { | |
545 | fl6.flowlabel = lsa->l2tp_flowinfo & IPV6_FLOWINFO_MASK; | |
546 | if (fl6.flowlabel&IPV6_FLOWLABEL_MASK) { | |
547 | flowlabel = fl6_sock_lookup(sk, fl6.flowlabel); | |
548 | if (flowlabel == NULL) | |
549 | return -EINVAL; | |
a32e0eec CE |
550 | } |
551 | } | |
552 | ||
553 | /* | |
554 | * Otherwise it will be difficult to maintain | |
555 | * sk->sk_dst_cache. | |
556 | */ | |
557 | if (sk->sk_state == TCP_ESTABLISHED && | |
efe4208f ED |
558 | ipv6_addr_equal(daddr, &sk->sk_v6_daddr)) |
559 | daddr = &sk->sk_v6_daddr; | |
a32e0eec CE |
560 | |
561 | if (addr_len >= sizeof(struct sockaddr_in6) && | |
562 | lsa->l2tp_scope_id && | |
563 | ipv6_addr_type(daddr) & IPV6_ADDR_LINKLOCAL) | |
564 | fl6.flowi6_oif = lsa->l2tp_scope_id; | |
565 | } else { | |
566 | if (sk->sk_state != TCP_ESTABLISHED) | |
567 | return -EDESTADDRREQ; | |
568 | ||
efe4208f | 569 | daddr = &sk->sk_v6_daddr; |
a32e0eec CE |
570 | fl6.flowlabel = np->flow_label; |
571 | } | |
572 | ||
573 | if (fl6.flowi6_oif == 0) | |
574 | fl6.flowi6_oif = sk->sk_bound_dev_if; | |
575 | ||
576 | if (msg->msg_controllen) { | |
577 | opt = &opt_space; | |
578 | memset(opt, 0, sizeof(struct ipv6_txoptions)); | |
579 | opt->tot_len = sizeof(struct ipv6_txoptions); | |
26879da5 | 580 | ipc6.opt = opt; |
a32e0eec | 581 | |
26879da5 WW |
582 | err = ip6_datagram_send_ctl(sock_net(sk), sk, msg, &fl6, &ipc6, |
583 | &sockc_unused); | |
584 | if (err < 0) { | |
a32e0eec CE |
585 | fl6_sock_release(flowlabel); |
586 | return err; | |
587 | } | |
588 | if ((fl6.flowlabel & IPV6_FLOWLABEL_MASK) && !flowlabel) { | |
589 | flowlabel = fl6_sock_lookup(sk, fl6.flowlabel); | |
590 | if (flowlabel == NULL) | |
591 | return -EINVAL; | |
592 | } | |
593 | if (!(opt->opt_nflen|opt->opt_flen)) | |
594 | opt = NULL; | |
595 | } | |
596 | ||
45f6fad8 ED |
597 | if (!opt) { |
598 | opt = txopt_get(np); | |
599 | opt_to_free = opt; | |
600 | } | |
a32e0eec CE |
601 | if (flowlabel) |
602 | opt = fl6_merge_options(&opt_space, flowlabel, opt); | |
603 | opt = ipv6_fixup_options(&opt_space, opt); | |
26879da5 | 604 | ipc6.opt = opt; |
a32e0eec CE |
605 | |
606 | fl6.flowi6_proto = sk->sk_protocol; | |
607 | if (!ipv6_addr_any(daddr)) | |
608 | fl6.daddr = *daddr; | |
609 | else | |
610 | fl6.daddr.s6_addr[15] = 0x1; /* :: means loopback (BSD'ism) */ | |
611 | if (ipv6_addr_any(&fl6.saddr) && !ipv6_addr_any(&np->saddr)) | |
612 | fl6.saddr = np->saddr; | |
613 | ||
614 | final_p = fl6_update_dst(&fl6, opt, &final); | |
615 | ||
616 | if (!fl6.flowi6_oif && ipv6_addr_is_multicast(&fl6.daddr)) | |
617 | fl6.flowi6_oif = np->mcast_oif; | |
618 | else if (!fl6.flowi6_oif) | |
619 | fl6.flowi6_oif = np->ucast_oif; | |
620 | ||
621 | security_sk_classify_flow(sk, flowi6_to_flowi(&fl6)); | |
622 | ||
38b7097b HFS |
623 | if (ipc6.tclass < 0) |
624 | ipc6.tclass = np->tclass; | |
625 | ||
626 | fl6.flowlabel = ip6_make_flowinfo(ipc6.tclass, fl6.flowlabel); | |
627 | ||
0e0d44ab | 628 | dst = ip6_dst_lookup_flow(sk, &fl6, final_p); |
a32e0eec CE |
629 | if (IS_ERR(dst)) { |
630 | err = PTR_ERR(dst); | |
631 | goto out; | |
632 | } | |
633 | ||
26879da5 WW |
634 | if (ipc6.hlimit < 0) |
635 | ipc6.hlimit = ip6_sk_dst_hoplimit(np, &fl6, dst); | |
a32e0eec | 636 | |
26879da5 WW |
637 | if (ipc6.dontfrag < 0) |
638 | ipc6.dontfrag = np->dontfrag; | |
a32e0eec CE |
639 | |
640 | if (msg->msg_flags & MSG_CONFIRM) | |
641 | goto do_confirm; | |
642 | ||
643 | back_from_confirm: | |
644 | lock_sock(sk); | |
f69e6d13 | 645 | err = ip6_append_data(sk, ip_generic_getfrag, msg, |
26879da5 | 646 | ulen, transhdrlen, &ipc6, |
a32e0eec | 647 | &fl6, (struct rt6_info *)dst, |
26879da5 | 648 | msg->msg_flags, &sockc_unused); |
a32e0eec CE |
649 | if (err) |
650 | ip6_flush_pending_frames(sk); | |
651 | else if (!(msg->msg_flags & MSG_MORE)) | |
652 | err = l2tp_ip6_push_pending_frames(sk); | |
653 | release_sock(sk); | |
654 | done: | |
655 | dst_release(dst); | |
656 | out: | |
657 | fl6_sock_release(flowlabel); | |
45f6fad8 | 658 | txopt_put(opt_to_free); |
a32e0eec CE |
659 | |
660 | return err < 0 ? err : len; | |
661 | ||
662 | do_confirm: | |
0dec879f JA |
663 | if (msg->msg_flags & MSG_PROBE) |
664 | dst_confirm_neigh(dst, &fl6.daddr); | |
a32e0eec CE |
665 | if (!(msg->msg_flags & MSG_PROBE) || len) |
666 | goto back_from_confirm; | |
667 | err = 0; | |
668 | goto done; | |
669 | } | |
670 | ||
1b784140 YX |
671 | static int l2tp_ip6_recvmsg(struct sock *sk, struct msghdr *msg, size_t len, |
672 | int noblock, int flags, int *addr_len) | |
a32e0eec | 673 | { |
700163db | 674 | struct ipv6_pinfo *np = inet6_sk(sk); |
342dfc30 | 675 | DECLARE_SOCKADDR(struct sockaddr_l2tpip6 *, lsa, msg->msg_name); |
a32e0eec CE |
676 | size_t copied = 0; |
677 | int err = -EOPNOTSUPP; | |
678 | struct sk_buff *skb; | |
679 | ||
680 | if (flags & MSG_OOB) | |
681 | goto out; | |
682 | ||
a32e0eec | 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); |
95d8b142 | 712 | *addr_len = sizeof(*lsa); |
a32e0eec CE |
713 | } |
714 | ||
700163db TP |
715 | if (np->rxopt.all) |
716 | ip6_datagram_recv_ctl(sk, msg, skb); | |
a32e0eec CE |
717 | |
718 | if (flags & MSG_TRUNC) | |
719 | copied = skb->len; | |
720 | done: | |
721 | skb_free_datagram(sk, skb); | |
722 | out: | |
723 | return err ? err : copied; | |
724 | } | |
725 | ||
726 | static struct proto l2tp_ip6_prot = { | |
727 | .name = "L2TP/IPv6", | |
728 | .owner = THIS_MODULE, | |
729 | .init = l2tp_ip6_open, | |
730 | .close = l2tp_ip6_close, | |
731 | .bind = l2tp_ip6_bind, | |
732 | .connect = l2tp_ip6_connect, | |
c51ce497 | 733 | .disconnect = l2tp_ip6_disconnect, |
72fb96e7 | 734 | .ioctl = l2tp_ioctl, |
a32e0eec CE |
735 | .destroy = l2tp_ip6_destroy_sock, |
736 | .setsockopt = ipv6_setsockopt, | |
737 | .getsockopt = ipv6_getsockopt, | |
738 | .sendmsg = l2tp_ip6_sendmsg, | |
739 | .recvmsg = l2tp_ip6_recvmsg, | |
740 | .backlog_rcv = l2tp_ip6_backlog_recv, | |
496611d7 | 741 | .hash = inet6_hash, |
a32e0eec CE |
742 | .unhash = inet_unhash, |
743 | .obj_size = sizeof(struct l2tp_ip6_sock), | |
744 | #ifdef CONFIG_COMPAT | |
745 | .compat_setsockopt = compat_ipv6_setsockopt, | |
746 | .compat_getsockopt = compat_ipv6_getsockopt, | |
747 | #endif | |
748 | }; | |
749 | ||
750 | static const struct proto_ops l2tp_ip6_ops = { | |
751 | .family = PF_INET6, | |
752 | .owner = THIS_MODULE, | |
753 | .release = inet6_release, | |
754 | .bind = inet6_bind, | |
755 | .connect = inet_dgram_connect, | |
756 | .socketpair = sock_no_socketpair, | |
757 | .accept = sock_no_accept, | |
758 | .getname = l2tp_ip6_getname, | |
759 | .poll = datagram_poll, | |
760 | .ioctl = inet6_ioctl, | |
761 | .listen = sock_no_listen, | |
762 | .shutdown = inet_shutdown, | |
763 | .setsockopt = sock_common_setsockopt, | |
764 | .getsockopt = sock_common_getsockopt, | |
765 | .sendmsg = inet_sendmsg, | |
766 | .recvmsg = sock_common_recvmsg, | |
767 | .mmap = sock_no_mmap, | |
768 | .sendpage = sock_no_sendpage, | |
769 | #ifdef CONFIG_COMPAT | |
770 | .compat_setsockopt = compat_sock_common_setsockopt, | |
771 | .compat_getsockopt = compat_sock_common_getsockopt, | |
772 | #endif | |
773 | }; | |
774 | ||
775 | static struct inet_protosw l2tp_ip6_protosw = { | |
776 | .type = SOCK_DGRAM, | |
777 | .protocol = IPPROTO_L2TP, | |
778 | .prot = &l2tp_ip6_prot, | |
779 | .ops = &l2tp_ip6_ops, | |
a32e0eec CE |
780 | }; |
781 | ||
782 | static struct inet6_protocol l2tp_ip6_protocol __read_mostly = { | |
783 | .handler = l2tp_ip6_recv, | |
784 | }; | |
785 | ||
786 | static int __init l2tp_ip6_init(void) | |
787 | { | |
788 | int err; | |
789 | ||
a4ca44fa | 790 | pr_info("L2TP IP encapsulation support for IPv6 (L2TPv3)\n"); |
a32e0eec CE |
791 | |
792 | err = proto_register(&l2tp_ip6_prot, 1); | |
793 | if (err != 0) | |
794 | goto out; | |
795 | ||
796 | err = inet6_add_protocol(&l2tp_ip6_protocol, IPPROTO_L2TP); | |
797 | if (err) | |
798 | goto out1; | |
799 | ||
800 | inet6_register_protosw(&l2tp_ip6_protosw); | |
801 | return 0; | |
802 | ||
803 | out1: | |
804 | proto_unregister(&l2tp_ip6_prot); | |
805 | out: | |
806 | return err; | |
807 | } | |
808 | ||
809 | static void __exit l2tp_ip6_exit(void) | |
810 | { | |
811 | inet6_unregister_protosw(&l2tp_ip6_protosw); | |
812 | inet6_del_protocol(&l2tp_ip6_protocol, IPPROTO_L2TP); | |
813 | proto_unregister(&l2tp_ip6_prot); | |
814 | } | |
815 | ||
816 | module_init(l2tp_ip6_init); | |
817 | module_exit(l2tp_ip6_exit); | |
818 | ||
819 | MODULE_LICENSE("GPL"); | |
820 | MODULE_AUTHOR("Chris Elston <celston@katalix.com>"); | |
821 | MODULE_DESCRIPTION("L2TP IP encapsulation for IPv6"); | |
822 | MODULE_VERSION("1.0"); | |
823 | ||
824 | /* Use the value of SOCK_DGRAM (2) directory, because __stringify doesn't like | |
825 | * enums | |
826 | */ | |
827 | MODULE_ALIAS_NET_PF_PROTO_TYPE(PF_INET6, 2, IPPROTO_L2TP); | |
163c2e25 | 828 | MODULE_ALIAS_NET_PF_PROTO(PF_INET6, IPPROTO_L2TP); |