Commit | Line | Data |
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2874c5fd | 1 | // SPDX-License-Identifier: GPL-2.0-or-later |
a32e0eec CE |
2 | /* |
3 | * L2TPv3 IP encapsulation support for IPv6 | |
4 | * | |
5 | * Copyright (c) 2012 Katalix Systems Ltd | |
a32e0eec CE |
6 | */ |
7 | ||
a4ca44fa JP |
8 | #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt |
9 | ||
a32e0eec CE |
10 | #include <linux/icmp.h> |
11 | #include <linux/module.h> | |
12 | #include <linux/skbuff.h> | |
13 | #include <linux/random.h> | |
14 | #include <linux/socket.h> | |
15 | #include <linux/l2tp.h> | |
16 | #include <linux/in.h> | |
17 | #include <linux/in6.h> | |
18 | #include <net/sock.h> | |
19 | #include <net/ip.h> | |
20 | #include <net/icmp.h> | |
21 | #include <net/udp.h> | |
22 | #include <net/inet_common.h> | |
23 | #include <net/inet_hashtables.h> | |
496611d7 | 24 | #include <net/inet6_hashtables.h> |
a32e0eec CE |
25 | #include <net/tcp_states.h> |
26 | #include <net/protocol.h> | |
27 | #include <net/xfrm.h> | |
28 | ||
29 | #include <net/transp_v6.h> | |
30 | #include <net/addrconf.h> | |
31 | #include <net/ip6_route.h> | |
32 | ||
33 | #include "l2tp_core.h" | |
34 | ||
35 | struct l2tp_ip6_sock { | |
36 | /* inet_sock has to be the first member of l2tp_ip6_sock */ | |
37 | struct inet_sock inet; | |
38 | ||
39 | u32 conn_id; | |
40 | u32 peer_conn_id; | |
41 | ||
42 | /* ipv6_pinfo has to be the last member of l2tp_ip6_sock, see | |
43 | inet6_sk_generic */ | |
44 | struct ipv6_pinfo inet6; | |
45 | }; | |
46 | ||
47 | static DEFINE_RWLOCK(l2tp_ip6_lock); | |
48 | static struct hlist_head l2tp_ip6_table; | |
49 | static struct hlist_head l2tp_ip6_bind_table; | |
50 | ||
51 | static inline struct l2tp_ip6_sock *l2tp_ip6_sk(const struct sock *sk) | |
52 | { | |
53 | return (struct l2tp_ip6_sock *)sk; | |
54 | } | |
55 | ||
bb39b0bd GN |
56 | static struct sock *__l2tp_ip6_bind_lookup(const struct net *net, |
57 | const struct in6_addr *laddr, | |
a9b2dff8 | 58 | const struct in6_addr *raddr, |
a32e0eec CE |
59 | int dif, u32 tunnel_id) |
60 | { | |
a32e0eec CE |
61 | struct sock *sk; |
62 | ||
b67bfe0d | 63 | sk_for_each_bound(sk, &l2tp_ip6_bind_table) { |
97b84fd6 | 64 | const struct in6_addr *sk_laddr = inet6_rcv_saddr(sk); |
a9b2dff8 | 65 | const struct in6_addr *sk_raddr = &sk->sk_v6_daddr; |
bb39b0bd | 66 | const struct l2tp_ip6_sock *l2tp = l2tp_ip6_sk(sk); |
a32e0eec | 67 | |
c5fdae04 GN |
68 | if (!net_eq(sock_net(sk), net)) |
69 | continue; | |
70 | ||
71 | if (sk->sk_bound_dev_if && dif && sk->sk_bound_dev_if != dif) | |
72 | continue; | |
73 | ||
74 | if (sk_laddr && !ipv6_addr_any(sk_laddr) && | |
75 | !ipv6_addr_any(laddr) && !ipv6_addr_equal(sk_laddr, laddr)) | |
76 | continue; | |
77 | ||
78 | if (!ipv6_addr_any(sk_raddr) && raddr && | |
79 | !ipv6_addr_any(raddr) && !ipv6_addr_equal(sk_raddr, raddr)) | |
80 | continue; | |
81 | ||
82 | if (l2tp->conn_id != tunnel_id) | |
83 | continue; | |
84 | ||
85 | goto found; | |
a32e0eec CE |
86 | } |
87 | ||
88 | sk = NULL; | |
89 | found: | |
90 | return sk; | |
91 | } | |
92 | ||
a32e0eec CE |
93 | /* When processing receive frames, there are two cases to |
94 | * consider. Data frames consist of a non-zero session-id and an | |
95 | * optional cookie. Control frames consist of a regular L2TP header | |
96 | * preceded by 32-bits of zeros. | |
97 | * | |
98 | * L2TPv3 Session Header Over IP | |
99 | * | |
100 | * 0 1 2 3 | |
101 | * 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 | |
102 | * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | |
103 | * | Session ID | | |
104 | * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | |
105 | * | Cookie (optional, maximum 64 bits)... | |
106 | * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | |
107 | * | | |
108 | * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | |
109 | * | |
110 | * L2TPv3 Control Message Header Over IP | |
111 | * | |
112 | * 0 1 2 3 | |
113 | * 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 | |
114 | * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | |
115 | * | (32 bits of zeros) | | |
116 | * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | |
117 | * |T|L|x|x|S|x|x|x|x|x|x|x| Ver | Length | | |
118 | * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | |
119 | * | Control Connection ID | | |
120 | * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | |
121 | * | Ns | Nr | | |
122 | * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | |
123 | * | |
124 | * All control frames are passed to userspace. | |
125 | */ | |
126 | static int l2tp_ip6_recv(struct sk_buff *skb) | |
127 | { | |
0e6b5259 | 128 | struct net *net = dev_net(skb->dev); |
a32e0eec CE |
129 | struct sock *sk; |
130 | u32 session_id; | |
131 | u32 tunnel_id; | |
132 | unsigned char *ptr, *optr; | |
133 | struct l2tp_session *session; | |
134 | struct l2tp_tunnel *tunnel = NULL; | |
8f7dc9ae | 135 | struct ipv6hdr *iph; |
a32e0eec | 136 | int length; |
a32e0eec | 137 | |
a32e0eec CE |
138 | if (!pskb_may_pull(skb, 4)) |
139 | goto discard; | |
140 | ||
be447f30 HY |
141 | /* Point to L2TP header */ |
142 | optr = ptr = skb->data; | |
a32e0eec CE |
143 | session_id = ntohl(*((__be32 *) ptr)); |
144 | ptr += 4; | |
145 | ||
146 | /* RFC3931: L2TP/IP packets have the first 4 bytes containing | |
147 | * the session_id. If it is 0, the packet is a L2TP control | |
148 | * frame and the session_id value can be discarded. | |
149 | */ | |
150 | if (session_id == 0) { | |
151 | __skb_pull(skb, 4); | |
152 | goto pass_up; | |
153 | } | |
154 | ||
155 | /* Ok, this is a data packet. Lookup the session. */ | |
01e28b92 | 156 | session = l2tp_session_get(net, session_id); |
61b9a047 | 157 | if (!session) |
a32e0eec CE |
158 | goto discard; |
159 | ||
160 | tunnel = session->tunnel; | |
61b9a047 GN |
161 | if (!tunnel) |
162 | goto discard_sess; | |
a32e0eec CE |
163 | |
164 | /* Trace packet contents, if enabled */ | |
165 | if (tunnel->debug & L2TP_MSG_DATA) { | |
166 | length = min(32u, skb->len); | |
167 | if (!pskb_may_pull(skb, length)) | |
61b9a047 | 168 | goto discard_sess; |
a32e0eec | 169 | |
be447f30 HY |
170 | /* Point to L2TP header */ |
171 | optr = ptr = skb->data; | |
172 | ptr += 4; | |
a4ca44fa JP |
173 | pr_debug("%s: ip recv\n", tunnel->name); |
174 | print_hex_dump_bytes("", DUMP_PREFIX_OFFSET, ptr, length); | |
a32e0eec CE |
175 | } |
176 | ||
4522a70d JW |
177 | if (l2tp_v3_ensure_opt_in_linear(session, skb, &ptr, &optr)) |
178 | goto discard_sess; | |
179 | ||
2b139e6b | 180 | l2tp_recv_common(session, skb, ptr, optr, 0, skb->len); |
61b9a047 GN |
181 | l2tp_session_dec_refcount(session); |
182 | ||
a32e0eec CE |
183 | return 0; |
184 | ||
185 | pass_up: | |
186 | /* Get the tunnel_id from the L2TP header */ | |
187 | if (!pskb_may_pull(skb, 12)) | |
188 | goto discard; | |
189 | ||
190 | if ((skb->data[0] & 0xc0) != 0xc0) | |
191 | goto discard; | |
192 | ||
193 | tunnel_id = ntohl(*(__be32 *) &skb->data[4]); | |
8f7dc9ae GN |
194 | iph = ipv6_hdr(skb); |
195 | ||
196 | read_lock_bh(&l2tp_ip6_lock); | |
197 | sk = __l2tp_ip6_bind_lookup(net, &iph->daddr, &iph->saddr, | |
198 | inet6_iif(skb), tunnel_id); | |
199 | if (!sk) { | |
a32e0eec | 200 | read_unlock_bh(&l2tp_ip6_lock); |
8f7dc9ae | 201 | goto discard; |
a32e0eec | 202 | } |
8f7dc9ae GN |
203 | sock_hold(sk); |
204 | read_unlock_bh(&l2tp_ip6_lock); | |
a32e0eec | 205 | |
a32e0eec CE |
206 | if (!xfrm6_policy_check(sk, XFRM_POLICY_IN, skb)) |
207 | goto discard_put; | |
208 | ||
209 | nf_reset(skb); | |
210 | ||
211 | return sk_receive_skb(sk, skb, 1); | |
212 | ||
61b9a047 | 213 | discard_sess: |
61b9a047 GN |
214 | l2tp_session_dec_refcount(session); |
215 | goto discard; | |
216 | ||
a32e0eec CE |
217 | discard_put: |
218 | sock_put(sk); | |
219 | ||
220 | discard: | |
221 | kfree_skb(skb); | |
222 | return 0; | |
223 | } | |
224 | ||
225 | static int l2tp_ip6_open(struct sock *sk) | |
226 | { | |
227 | /* Prevent autobind. We don't have ports. */ | |
228 | inet_sk(sk)->inet_num = IPPROTO_L2TP; | |
229 | ||
230 | write_lock_bh(&l2tp_ip6_lock); | |
231 | sk_add_node(sk, &l2tp_ip6_table); | |
232 | write_unlock_bh(&l2tp_ip6_lock); | |
233 | ||
234 | return 0; | |
235 | } | |
236 | ||
237 | static void l2tp_ip6_close(struct sock *sk, long timeout) | |
238 | { | |
239 | write_lock_bh(&l2tp_ip6_lock); | |
240 | hlist_del_init(&sk->sk_bind_node); | |
241 | sk_del_node_init(sk); | |
242 | write_unlock_bh(&l2tp_ip6_lock); | |
243 | ||
244 | sk_common_release(sk); | |
245 | } | |
246 | ||
247 | static void l2tp_ip6_destroy_sock(struct sock *sk) | |
248 | { | |
d00fa9ad | 249 | struct l2tp_tunnel *tunnel = sk->sk_user_data; |
93606317 | 250 | |
a32e0eec CE |
251 | lock_sock(sk); |
252 | ip6_flush_pending_frames(sk); | |
253 | release_sock(sk); | |
254 | ||
d00fa9ad JC |
255 | if (tunnel) |
256 | l2tp_tunnel_delete(tunnel); | |
93606317 | 257 | |
a32e0eec CE |
258 | inet6_destroy_sock(sk); |
259 | } | |
260 | ||
261 | static int l2tp_ip6_bind(struct sock *sk, struct sockaddr *uaddr, int addr_len) | |
262 | { | |
263 | struct inet_sock *inet = inet_sk(sk); | |
264 | struct ipv6_pinfo *np = inet6_sk(sk); | |
265 | struct sockaddr_l2tpip6 *addr = (struct sockaddr_l2tpip6 *) uaddr; | |
0e6b5259 | 266 | struct net *net = sock_net(sk); |
a32e0eec | 267 | __be32 v4addr = 0; |
d5e3a190 | 268 | int bound_dev_if; |
a32e0eec CE |
269 | int addr_type; |
270 | int err; | |
271 | ||
c51ce497 JC |
272 | if (addr->l2tp_family != AF_INET6) |
273 | return -EINVAL; | |
a32e0eec CE |
274 | if (addr_len < sizeof(*addr)) |
275 | return -EINVAL; | |
276 | ||
277 | addr_type = ipv6_addr_type(&addr->l2tp_addr); | |
278 | ||
279 | /* l2tp_ip6 sockets are IPv6 only */ | |
280 | if (addr_type == IPV6_ADDR_MAPPED) | |
281 | return -EADDRNOTAVAIL; | |
282 | ||
283 | /* L2TP is point-point, not multicast */ | |
284 | if (addr_type & IPV6_ADDR_MULTICAST) | |
285 | return -EADDRNOTAVAIL; | |
286 | ||
a32e0eec CE |
287 | lock_sock(sk); |
288 | ||
289 | err = -EINVAL; | |
32c23116 GN |
290 | if (!sock_flag(sk, SOCK_ZAPPED)) |
291 | goto out_unlock; | |
292 | ||
a32e0eec CE |
293 | if (sk->sk_state != TCP_CLOSE) |
294 | goto out_unlock; | |
295 | ||
d5e3a190 GN |
296 | bound_dev_if = sk->sk_bound_dev_if; |
297 | ||
a32e0eec CE |
298 | /* Check if the address belongs to the host. */ |
299 | rcu_read_lock(); | |
300 | if (addr_type != IPV6_ADDR_ANY) { | |
301 | struct net_device *dev = NULL; | |
302 | ||
303 | if (addr_type & IPV6_ADDR_LINKLOCAL) { | |
d5e3a190 GN |
304 | if (addr->l2tp_scope_id) |
305 | bound_dev_if = addr->l2tp_scope_id; | |
a32e0eec CE |
306 | |
307 | /* Binding to link-local address requires an | |
d5e3a190 GN |
308 | * interface. |
309 | */ | |
310 | if (!bound_dev_if) | |
a32e0eec CE |
311 | goto out_unlock_rcu; |
312 | ||
313 | err = -ENODEV; | |
d5e3a190 | 314 | dev = dev_get_by_index_rcu(sock_net(sk), bound_dev_if); |
a32e0eec CE |
315 | if (!dev) |
316 | goto out_unlock_rcu; | |
317 | } | |
318 | ||
319 | /* ipv4 addr of the socket is invalid. Only the | |
320 | * unspecified and mapped address have a v4 equivalent. | |
321 | */ | |
322 | v4addr = LOOPBACK4_IPV6; | |
323 | err = -EADDRNOTAVAIL; | |
324 | if (!ipv6_chk_addr(sock_net(sk), &addr->l2tp_addr, dev, 0)) | |
325 | goto out_unlock_rcu; | |
326 | } | |
327 | rcu_read_unlock(); | |
328 | ||
d5e3a190 | 329 | write_lock_bh(&l2tp_ip6_lock); |
a9b2dff8 | 330 | if (__l2tp_ip6_bind_lookup(net, &addr->l2tp_addr, NULL, bound_dev_if, |
d5e3a190 GN |
331 | addr->l2tp_conn_id)) { |
332 | write_unlock_bh(&l2tp_ip6_lock); | |
333 | err = -EADDRINUSE; | |
334 | goto out_unlock; | |
335 | } | |
336 | ||
337 | inet->inet_saddr = v4addr; | |
338 | inet->inet_rcv_saddr = v4addr; | |
339 | sk->sk_bound_dev_if = bound_dev_if; | |
efe4208f | 340 | sk->sk_v6_rcv_saddr = addr->l2tp_addr; |
a32e0eec CE |
341 | np->saddr = addr->l2tp_addr; |
342 | ||
343 | l2tp_ip6_sk(sk)->conn_id = addr->l2tp_conn_id; | |
344 | ||
a32e0eec CE |
345 | sk_add_bind_node(sk, &l2tp_ip6_bind_table); |
346 | sk_del_node_init(sk); | |
347 | write_unlock_bh(&l2tp_ip6_lock); | |
348 | ||
c51ce497 | 349 | sock_reset_flag(sk, SOCK_ZAPPED); |
a32e0eec CE |
350 | release_sock(sk); |
351 | return 0; | |
352 | ||
353 | out_unlock_rcu: | |
354 | rcu_read_unlock(); | |
355 | out_unlock: | |
356 | release_sock(sk); | |
a32e0eec | 357 | |
a32e0eec CE |
358 | return err; |
359 | } | |
360 | ||
361 | static int l2tp_ip6_connect(struct sock *sk, struct sockaddr *uaddr, | |
362 | int addr_len) | |
363 | { | |
364 | struct sockaddr_l2tpip6 *lsa = (struct sockaddr_l2tpip6 *) uaddr; | |
365 | struct sockaddr_in6 *usin = (struct sockaddr_in6 *) uaddr; | |
366 | struct in6_addr *daddr; | |
367 | int addr_type; | |
368 | int rc; | |
369 | ||
370 | if (addr_len < sizeof(*lsa)) | |
371 | return -EINVAL; | |
372 | ||
82b276cd HFS |
373 | if (usin->sin6_family != AF_INET6) |
374 | return -EINVAL; | |
375 | ||
a32e0eec CE |
376 | addr_type = ipv6_addr_type(&usin->sin6_addr); |
377 | if (addr_type & IPV6_ADDR_MULTICAST) | |
378 | return -EINVAL; | |
379 | ||
380 | if (addr_type & IPV6_ADDR_MAPPED) { | |
381 | daddr = &usin->sin6_addr; | |
382 | if (ipv4_is_multicast(daddr->s6_addr32[3])) | |
383 | return -EINVAL; | |
384 | } | |
385 | ||
a32e0eec CE |
386 | lock_sock(sk); |
387 | ||
0382a25a GN |
388 | /* Must bind first - autobinding does not work */ |
389 | if (sock_flag(sk, SOCK_ZAPPED)) { | |
390 | rc = -EINVAL; | |
391 | goto out_sk; | |
392 | } | |
393 | ||
394 | rc = __ip6_datagram_connect(sk, uaddr, addr_len); | |
395 | if (rc < 0) | |
396 | goto out_sk; | |
397 | ||
a32e0eec CE |
398 | l2tp_ip6_sk(sk)->peer_conn_id = lsa->l2tp_conn_id; |
399 | ||
400 | write_lock_bh(&l2tp_ip6_lock); | |
401 | hlist_del_init(&sk->sk_bind_node); | |
402 | sk_add_bind_node(sk, &l2tp_ip6_bind_table); | |
403 | write_unlock_bh(&l2tp_ip6_lock); | |
404 | ||
0382a25a | 405 | out_sk: |
a32e0eec CE |
406 | release_sock(sk); |
407 | ||
408 | return rc; | |
409 | } | |
410 | ||
c51ce497 JC |
411 | static int l2tp_ip6_disconnect(struct sock *sk, int flags) |
412 | { | |
413 | if (sock_flag(sk, SOCK_ZAPPED)) | |
414 | return 0; | |
415 | ||
286c72de | 416 | return __udp_disconnect(sk, flags); |
c51ce497 JC |
417 | } |
418 | ||
a32e0eec | 419 | static int l2tp_ip6_getname(struct socket *sock, struct sockaddr *uaddr, |
9b2c45d4 | 420 | int peer) |
a32e0eec CE |
421 | { |
422 | struct sockaddr_l2tpip6 *lsa = (struct sockaddr_l2tpip6 *)uaddr; | |
423 | struct sock *sk = sock->sk; | |
424 | struct ipv6_pinfo *np = inet6_sk(sk); | |
425 | struct l2tp_ip6_sock *lsk = l2tp_ip6_sk(sk); | |
426 | ||
427 | lsa->l2tp_family = AF_INET6; | |
428 | lsa->l2tp_flowinfo = 0; | |
429 | lsa->l2tp_scope_id = 0; | |
04d4fbca | 430 | lsa->l2tp_unused = 0; |
a32e0eec CE |
431 | if (peer) { |
432 | if (!lsk->peer_conn_id) | |
433 | return -ENOTCONN; | |
434 | lsa->l2tp_conn_id = lsk->peer_conn_id; | |
efe4208f | 435 | lsa->l2tp_addr = sk->sk_v6_daddr; |
a32e0eec CE |
436 | if (np->sndflow) |
437 | lsa->l2tp_flowinfo = np->flow_label; | |
438 | } else { | |
efe4208f | 439 | if (ipv6_addr_any(&sk->sk_v6_rcv_saddr)) |
a32e0eec CE |
440 | lsa->l2tp_addr = np->saddr; |
441 | else | |
efe4208f | 442 | lsa->l2tp_addr = sk->sk_v6_rcv_saddr; |
a32e0eec CE |
443 | |
444 | lsa->l2tp_conn_id = lsk->conn_id; | |
445 | } | |
446 | if (ipv6_addr_type(&lsa->l2tp_addr) & IPV6_ADDR_LINKLOCAL) | |
447 | lsa->l2tp_scope_id = sk->sk_bound_dev_if; | |
9b2c45d4 | 448 | return sizeof(*lsa); |
a32e0eec CE |
449 | } |
450 | ||
451 | static int l2tp_ip6_backlog_recv(struct sock *sk, struct sk_buff *skb) | |
452 | { | |
453 | int rc; | |
454 | ||
455 | /* Charge it to the socket, dropping if the queue is full. */ | |
456 | rc = sock_queue_rcv_skb(sk, skb); | |
457 | if (rc < 0) | |
458 | goto drop; | |
459 | ||
460 | return 0; | |
461 | ||
462 | drop: | |
0e6b5259 | 463 | IP_INC_STATS(sock_net(sk), IPSTATS_MIB_INDISCARDS); |
a32e0eec CE |
464 | kfree_skb(skb); |
465 | return -1; | |
466 | } | |
467 | ||
468 | static int l2tp_ip6_push_pending_frames(struct sock *sk) | |
469 | { | |
470 | struct sk_buff *skb; | |
471 | __be32 *transhdr = NULL; | |
472 | int err = 0; | |
473 | ||
474 | skb = skb_peek(&sk->sk_write_queue); | |
475 | if (skb == NULL) | |
476 | goto out; | |
477 | ||
478 | transhdr = (__be32 *)skb_transport_header(skb); | |
479 | *transhdr = 0; | |
480 | ||
481 | err = ip6_push_pending_frames(sk); | |
482 | ||
483 | out: | |
484 | return err; | |
485 | } | |
486 | ||
487 | /* Userspace will call sendmsg() on the tunnel socket to send L2TP | |
488 | * control frames. | |
489 | */ | |
1b784140 | 490 | static int l2tp_ip6_sendmsg(struct sock *sk, struct msghdr *msg, size_t len) |
a32e0eec CE |
491 | { |
492 | struct ipv6_txoptions opt_space; | |
342dfc30 | 493 | DECLARE_SOCKADDR(struct sockaddr_l2tpip6 *, lsa, msg->msg_name); |
a32e0eec CE |
494 | struct in6_addr *daddr, *final_p, final; |
495 | struct ipv6_pinfo *np = inet6_sk(sk); | |
45f6fad8 | 496 | struct ipv6_txoptions *opt_to_free = NULL; |
a32e0eec CE |
497 | struct ipv6_txoptions *opt = NULL; |
498 | struct ip6_flowlabel *flowlabel = NULL; | |
499 | struct dst_entry *dst = NULL; | |
500 | struct flowi6 fl6; | |
26879da5 | 501 | struct ipcm6_cookie ipc6; |
a32e0eec | 502 | int addr_len = msg->msg_namelen; |
a32e0eec CE |
503 | int transhdrlen = 4; /* zero session-id */ |
504 | int ulen = len + transhdrlen; | |
505 | int err; | |
506 | ||
507 | /* Rough check on arithmetic overflow, | |
508 | better check is made in ip6_append_data(). | |
509 | */ | |
510 | if (len > INT_MAX) | |
511 | return -EMSGSIZE; | |
512 | ||
513 | /* Mirror BSD error message compatibility */ | |
514 | if (msg->msg_flags & MSG_OOB) | |
515 | return -EOPNOTSUPP; | |
516 | ||
517 | /* | |
518 | * Get and verify the address. | |
519 | */ | |
520 | memset(&fl6, 0, sizeof(fl6)); | |
521 | ||
522 | fl6.flowi6_mark = sk->sk_mark; | |
e2d118a1 | 523 | fl6.flowi6_uid = sk->sk_uid; |
a32e0eec | 524 | |
b515430a | 525 | ipcm6_init(&ipc6); |
26879da5 | 526 | |
a32e0eec CE |
527 | if (lsa) { |
528 | if (addr_len < SIN6_LEN_RFC2133) | |
529 | return -EINVAL; | |
530 | ||
531 | if (lsa->l2tp_family && lsa->l2tp_family != AF_INET6) | |
532 | return -EAFNOSUPPORT; | |
533 | ||
534 | daddr = &lsa->l2tp_addr; | |
535 | if (np->sndflow) { | |
536 | fl6.flowlabel = lsa->l2tp_flowinfo & IPV6_FLOWINFO_MASK; | |
537 | if (fl6.flowlabel&IPV6_FLOWLABEL_MASK) { | |
538 | flowlabel = fl6_sock_lookup(sk, fl6.flowlabel); | |
539 | if (flowlabel == NULL) | |
540 | return -EINVAL; | |
a32e0eec CE |
541 | } |
542 | } | |
543 | ||
544 | /* | |
545 | * Otherwise it will be difficult to maintain | |
546 | * sk->sk_dst_cache. | |
547 | */ | |
548 | if (sk->sk_state == TCP_ESTABLISHED && | |
efe4208f ED |
549 | ipv6_addr_equal(daddr, &sk->sk_v6_daddr)) |
550 | daddr = &sk->sk_v6_daddr; | |
a32e0eec CE |
551 | |
552 | if (addr_len >= sizeof(struct sockaddr_in6) && | |
553 | lsa->l2tp_scope_id && | |
554 | ipv6_addr_type(daddr) & IPV6_ADDR_LINKLOCAL) | |
555 | fl6.flowi6_oif = lsa->l2tp_scope_id; | |
556 | } else { | |
557 | if (sk->sk_state != TCP_ESTABLISHED) | |
558 | return -EDESTADDRREQ; | |
559 | ||
efe4208f | 560 | daddr = &sk->sk_v6_daddr; |
a32e0eec CE |
561 | fl6.flowlabel = np->flow_label; |
562 | } | |
563 | ||
564 | if (fl6.flowi6_oif == 0) | |
565 | fl6.flowi6_oif = sk->sk_bound_dev_if; | |
566 | ||
567 | if (msg->msg_controllen) { | |
568 | opt = &opt_space; | |
569 | memset(opt, 0, sizeof(struct ipv6_txoptions)); | |
570 | opt->tot_len = sizeof(struct ipv6_txoptions); | |
26879da5 | 571 | ipc6.opt = opt; |
a32e0eec | 572 | |
5fdaa88d | 573 | err = ip6_datagram_send_ctl(sock_net(sk), sk, msg, &fl6, &ipc6); |
26879da5 | 574 | if (err < 0) { |
a32e0eec CE |
575 | fl6_sock_release(flowlabel); |
576 | return err; | |
577 | } | |
578 | if ((fl6.flowlabel & IPV6_FLOWLABEL_MASK) && !flowlabel) { | |
579 | flowlabel = fl6_sock_lookup(sk, fl6.flowlabel); | |
580 | if (flowlabel == NULL) | |
581 | return -EINVAL; | |
582 | } | |
583 | if (!(opt->opt_nflen|opt->opt_flen)) | |
584 | opt = NULL; | |
585 | } | |
586 | ||
45f6fad8 ED |
587 | if (!opt) { |
588 | opt = txopt_get(np); | |
589 | opt_to_free = opt; | |
590 | } | |
a32e0eec CE |
591 | if (flowlabel) |
592 | opt = fl6_merge_options(&opt_space, flowlabel, opt); | |
593 | opt = ipv6_fixup_options(&opt_space, opt); | |
26879da5 | 594 | ipc6.opt = opt; |
a32e0eec CE |
595 | |
596 | fl6.flowi6_proto = sk->sk_protocol; | |
597 | if (!ipv6_addr_any(daddr)) | |
598 | fl6.daddr = *daddr; | |
599 | else | |
600 | fl6.daddr.s6_addr[15] = 0x1; /* :: means loopback (BSD'ism) */ | |
601 | if (ipv6_addr_any(&fl6.saddr) && !ipv6_addr_any(&np->saddr)) | |
602 | fl6.saddr = np->saddr; | |
603 | ||
604 | final_p = fl6_update_dst(&fl6, opt, &final); | |
605 | ||
606 | if (!fl6.flowi6_oif && ipv6_addr_is_multicast(&fl6.daddr)) | |
607 | fl6.flowi6_oif = np->mcast_oif; | |
608 | else if (!fl6.flowi6_oif) | |
609 | fl6.flowi6_oif = np->ucast_oif; | |
610 | ||
611 | security_sk_classify_flow(sk, flowi6_to_flowi(&fl6)); | |
612 | ||
38b7097b HFS |
613 | if (ipc6.tclass < 0) |
614 | ipc6.tclass = np->tclass; | |
615 | ||
616 | fl6.flowlabel = ip6_make_flowinfo(ipc6.tclass, fl6.flowlabel); | |
617 | ||
0e0d44ab | 618 | dst = ip6_dst_lookup_flow(sk, &fl6, final_p); |
a32e0eec CE |
619 | if (IS_ERR(dst)) { |
620 | err = PTR_ERR(dst); | |
621 | goto out; | |
622 | } | |
623 | ||
26879da5 WW |
624 | if (ipc6.hlimit < 0) |
625 | ipc6.hlimit = ip6_sk_dst_hoplimit(np, &fl6, dst); | |
a32e0eec | 626 | |
26879da5 WW |
627 | if (ipc6.dontfrag < 0) |
628 | ipc6.dontfrag = np->dontfrag; | |
a32e0eec CE |
629 | |
630 | if (msg->msg_flags & MSG_CONFIRM) | |
631 | goto do_confirm; | |
632 | ||
633 | back_from_confirm: | |
634 | lock_sock(sk); | |
f69e6d13 | 635 | err = ip6_append_data(sk, ip_generic_getfrag, msg, |
26879da5 | 636 | ulen, transhdrlen, &ipc6, |
a32e0eec | 637 | &fl6, (struct rt6_info *)dst, |
5fdaa88d | 638 | msg->msg_flags); |
a32e0eec CE |
639 | if (err) |
640 | ip6_flush_pending_frames(sk); | |
641 | else if (!(msg->msg_flags & MSG_MORE)) | |
642 | err = l2tp_ip6_push_pending_frames(sk); | |
643 | release_sock(sk); | |
644 | done: | |
645 | dst_release(dst); | |
646 | out: | |
647 | fl6_sock_release(flowlabel); | |
45f6fad8 | 648 | txopt_put(opt_to_free); |
a32e0eec CE |
649 | |
650 | return err < 0 ? err : len; | |
651 | ||
652 | do_confirm: | |
0dec879f JA |
653 | if (msg->msg_flags & MSG_PROBE) |
654 | dst_confirm_neigh(dst, &fl6.daddr); | |
a32e0eec CE |
655 | if (!(msg->msg_flags & MSG_PROBE) || len) |
656 | goto back_from_confirm; | |
657 | err = 0; | |
658 | goto done; | |
659 | } | |
660 | ||
1b784140 YX |
661 | static int l2tp_ip6_recvmsg(struct sock *sk, struct msghdr *msg, size_t len, |
662 | int noblock, int flags, int *addr_len) | |
a32e0eec | 663 | { |
700163db | 664 | struct ipv6_pinfo *np = inet6_sk(sk); |
342dfc30 | 665 | DECLARE_SOCKADDR(struct sockaddr_l2tpip6 *, lsa, msg->msg_name); |
a32e0eec CE |
666 | size_t copied = 0; |
667 | int err = -EOPNOTSUPP; | |
668 | struct sk_buff *skb; | |
669 | ||
670 | if (flags & MSG_OOB) | |
671 | goto out; | |
672 | ||
a32e0eec | 673 | if (flags & MSG_ERRQUEUE) |
85fbaa75 | 674 | return ipv6_recv_error(sk, msg, len, addr_len); |
a32e0eec CE |
675 | |
676 | skb = skb_recv_datagram(sk, flags, noblock, &err); | |
677 | if (!skb) | |
678 | goto out; | |
679 | ||
680 | copied = skb->len; | |
681 | if (len < copied) { | |
682 | msg->msg_flags |= MSG_TRUNC; | |
683 | copied = len; | |
684 | } | |
685 | ||
51f3d02b | 686 | err = skb_copy_datagram_msg(skb, 0, msg, copied); |
a32e0eec CE |
687 | if (err) |
688 | goto done; | |
689 | ||
690 | sock_recv_timestamp(msg, sk, skb); | |
691 | ||
692 | /* Copy the address. */ | |
693 | if (lsa) { | |
694 | lsa->l2tp_family = AF_INET6; | |
695 | lsa->l2tp_unused = 0; | |
696 | lsa->l2tp_addr = ipv6_hdr(skb)->saddr; | |
697 | lsa->l2tp_flowinfo = 0; | |
698 | lsa->l2tp_scope_id = 0; | |
b860d3cc | 699 | lsa->l2tp_conn_id = 0; |
a32e0eec | 700 | if (ipv6_addr_type(&lsa->l2tp_addr) & IPV6_ADDR_LINKLOCAL) |
4330487a | 701 | lsa->l2tp_scope_id = inet6_iif(skb); |
163d1c3d | 702 | *addr_len = sizeof(*lsa); |
a32e0eec CE |
703 | } |
704 | ||
700163db TP |
705 | if (np->rxopt.all) |
706 | ip6_datagram_recv_ctl(sk, msg, skb); | |
a32e0eec CE |
707 | |
708 | if (flags & MSG_TRUNC) | |
709 | copied = skb->len; | |
710 | done: | |
711 | skb_free_datagram(sk, skb); | |
712 | out: | |
713 | return err ? err : copied; | |
714 | } | |
715 | ||
716 | static struct proto l2tp_ip6_prot = { | |
717 | .name = "L2TP/IPv6", | |
718 | .owner = THIS_MODULE, | |
719 | .init = l2tp_ip6_open, | |
720 | .close = l2tp_ip6_close, | |
721 | .bind = l2tp_ip6_bind, | |
722 | .connect = l2tp_ip6_connect, | |
c51ce497 | 723 | .disconnect = l2tp_ip6_disconnect, |
72fb96e7 | 724 | .ioctl = l2tp_ioctl, |
a32e0eec CE |
725 | .destroy = l2tp_ip6_destroy_sock, |
726 | .setsockopt = ipv6_setsockopt, | |
727 | .getsockopt = ipv6_getsockopt, | |
728 | .sendmsg = l2tp_ip6_sendmsg, | |
729 | .recvmsg = l2tp_ip6_recvmsg, | |
730 | .backlog_rcv = l2tp_ip6_backlog_recv, | |
496611d7 | 731 | .hash = inet6_hash, |
a32e0eec CE |
732 | .unhash = inet_unhash, |
733 | .obj_size = sizeof(struct l2tp_ip6_sock), | |
734 | #ifdef CONFIG_COMPAT | |
735 | .compat_setsockopt = compat_ipv6_setsockopt, | |
736 | .compat_getsockopt = compat_ipv6_getsockopt, | |
737 | #endif | |
738 | }; | |
739 | ||
740 | static const struct proto_ops l2tp_ip6_ops = { | |
741 | .family = PF_INET6, | |
742 | .owner = THIS_MODULE, | |
743 | .release = inet6_release, | |
744 | .bind = inet6_bind, | |
745 | .connect = inet_dgram_connect, | |
746 | .socketpair = sock_no_socketpair, | |
747 | .accept = sock_no_accept, | |
748 | .getname = l2tp_ip6_getname, | |
a11e1d43 | 749 | .poll = datagram_poll, |
a32e0eec | 750 | .ioctl = inet6_ioctl, |
c7cbdbf2 | 751 | .gettstamp = sock_gettstamp, |
a32e0eec CE |
752 | .listen = sock_no_listen, |
753 | .shutdown = inet_shutdown, | |
754 | .setsockopt = sock_common_setsockopt, | |
755 | .getsockopt = sock_common_getsockopt, | |
756 | .sendmsg = inet_sendmsg, | |
757 | .recvmsg = sock_common_recvmsg, | |
758 | .mmap = sock_no_mmap, | |
759 | .sendpage = sock_no_sendpage, | |
760 | #ifdef CONFIG_COMPAT | |
761 | .compat_setsockopt = compat_sock_common_setsockopt, | |
762 | .compat_getsockopt = compat_sock_common_getsockopt, | |
763 | #endif | |
764 | }; | |
765 | ||
766 | static struct inet_protosw l2tp_ip6_protosw = { | |
767 | .type = SOCK_DGRAM, | |
768 | .protocol = IPPROTO_L2TP, | |
769 | .prot = &l2tp_ip6_prot, | |
770 | .ops = &l2tp_ip6_ops, | |
a32e0eec CE |
771 | }; |
772 | ||
773 | static struct inet6_protocol l2tp_ip6_protocol __read_mostly = { | |
774 | .handler = l2tp_ip6_recv, | |
775 | }; | |
776 | ||
777 | static int __init l2tp_ip6_init(void) | |
778 | { | |
779 | int err; | |
780 | ||
a4ca44fa | 781 | pr_info("L2TP IP encapsulation support for IPv6 (L2TPv3)\n"); |
a32e0eec CE |
782 | |
783 | err = proto_register(&l2tp_ip6_prot, 1); | |
784 | if (err != 0) | |
785 | goto out; | |
786 | ||
787 | err = inet6_add_protocol(&l2tp_ip6_protocol, IPPROTO_L2TP); | |
788 | if (err) | |
789 | goto out1; | |
790 | ||
791 | inet6_register_protosw(&l2tp_ip6_protosw); | |
792 | return 0; | |
793 | ||
794 | out1: | |
795 | proto_unregister(&l2tp_ip6_prot); | |
796 | out: | |
797 | return err; | |
798 | } | |
799 | ||
800 | static void __exit l2tp_ip6_exit(void) | |
801 | { | |
802 | inet6_unregister_protosw(&l2tp_ip6_protosw); | |
803 | inet6_del_protocol(&l2tp_ip6_protocol, IPPROTO_L2TP); | |
804 | proto_unregister(&l2tp_ip6_prot); | |
805 | } | |
806 | ||
807 | module_init(l2tp_ip6_init); | |
808 | module_exit(l2tp_ip6_exit); | |
809 | ||
810 | MODULE_LICENSE("GPL"); | |
811 | MODULE_AUTHOR("Chris Elston <celston@katalix.com>"); | |
812 | MODULE_DESCRIPTION("L2TP IP encapsulation for IPv6"); | |
813 | MODULE_VERSION("1.0"); | |
814 | ||
815 | /* Use the value of SOCK_DGRAM (2) directory, because __stringify doesn't like | |
816 | * enums | |
817 | */ | |
818 | MODULE_ALIAS_NET_PF_PROTO_TYPE(PF_INET6, 2, IPPROTO_L2TP); | |
163c2e25 | 819 | MODULE_ALIAS_NET_PF_PROTO(PF_INET6, IPPROTO_L2TP); |