Commit | Line | Data |
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2874c5fd | 1 | // SPDX-License-Identifier: GPL-2.0-or-later |
20dcb110 | 2 | /* L2TPv3 IP encapsulation support for IPv6 |
a32e0eec CE |
3 | * |
4 | * Copyright (c) 2012 Katalix Systems Ltd | |
a32e0eec CE |
5 | */ |
6 | ||
a4ca44fa JP |
7 | #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt |
8 | ||
a32e0eec CE |
9 | #include <linux/icmp.h> |
10 | #include <linux/module.h> | |
11 | #include <linux/skbuff.h> | |
12 | #include <linux/random.h> | |
13 | #include <linux/socket.h> | |
14 | #include <linux/l2tp.h> | |
15 | #include <linux/in.h> | |
16 | #include <linux/in6.h> | |
17 | #include <net/sock.h> | |
18 | #include <net/ip.h> | |
19 | #include <net/icmp.h> | |
20 | #include <net/udp.h> | |
21 | #include <net/inet_common.h> | |
a32e0eec CE |
22 | #include <net/tcp_states.h> |
23 | #include <net/protocol.h> | |
24 | #include <net/xfrm.h> | |
25 | ||
26 | #include <net/transp_v6.h> | |
27 | #include <net/addrconf.h> | |
28 | #include <net/ip6_route.h> | |
29 | ||
30 | #include "l2tp_core.h" | |
31 | ||
32 | struct l2tp_ip6_sock { | |
33 | /* inet_sock has to be the first member of l2tp_ip6_sock */ | |
34 | struct inet_sock inet; | |
35 | ||
36 | u32 conn_id; | |
37 | u32 peer_conn_id; | |
38 | ||
a32e0eec CE |
39 | struct ipv6_pinfo inet6; |
40 | }; | |
41 | ||
42 | static DEFINE_RWLOCK(l2tp_ip6_lock); | |
43 | static struct hlist_head l2tp_ip6_table; | |
44 | static struct hlist_head l2tp_ip6_bind_table; | |
45 | ||
46 | static inline struct l2tp_ip6_sock *l2tp_ip6_sk(const struct sock *sk) | |
47 | { | |
48 | return (struct l2tp_ip6_sock *)sk; | |
49 | } | |
50 | ||
bb39b0bd GN |
51 | static struct sock *__l2tp_ip6_bind_lookup(const struct net *net, |
52 | const struct in6_addr *laddr, | |
a9b2dff8 | 53 | const struct in6_addr *raddr, |
a32e0eec CE |
54 | int dif, u32 tunnel_id) |
55 | { | |
a32e0eec CE |
56 | struct sock *sk; |
57 | ||
b67bfe0d | 58 | sk_for_each_bound(sk, &l2tp_ip6_bind_table) { |
97b84fd6 | 59 | const struct in6_addr *sk_laddr = inet6_rcv_saddr(sk); |
a9b2dff8 | 60 | const struct in6_addr *sk_raddr = &sk->sk_v6_daddr; |
bb39b0bd | 61 | const struct l2tp_ip6_sock *l2tp = l2tp_ip6_sk(sk); |
ff009403 | 62 | int bound_dev_if; |
a32e0eec | 63 | |
c5fdae04 GN |
64 | if (!net_eq(sock_net(sk), net)) |
65 | continue; | |
66 | ||
ff009403 ED |
67 | bound_dev_if = READ_ONCE(sk->sk_bound_dev_if); |
68 | if (bound_dev_if && dif && bound_dev_if != dif) | |
c5fdae04 GN |
69 | continue; |
70 | ||
71 | if (sk_laddr && !ipv6_addr_any(sk_laddr) && | |
72 | !ipv6_addr_any(laddr) && !ipv6_addr_equal(sk_laddr, laddr)) | |
73 | continue; | |
74 | ||
75 | if (!ipv6_addr_any(sk_raddr) && raddr && | |
76 | !ipv6_addr_any(raddr) && !ipv6_addr_equal(sk_raddr, raddr)) | |
77 | continue; | |
78 | ||
79 | if (l2tp->conn_id != tunnel_id) | |
80 | continue; | |
81 | ||
82 | goto found; | |
a32e0eec CE |
83 | } |
84 | ||
85 | sk = NULL; | |
86 | found: | |
87 | return sk; | |
88 | } | |
89 | ||
a32e0eec CE |
90 | /* When processing receive frames, there are two cases to |
91 | * consider. Data frames consist of a non-zero session-id and an | |
92 | * optional cookie. Control frames consist of a regular L2TP header | |
93 | * preceded by 32-bits of zeros. | |
94 | * | |
95 | * L2TPv3 Session Header Over IP | |
96 | * | |
97 | * 0 1 2 3 | |
98 | * 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 | |
99 | * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | |
100 | * | Session ID | | |
101 | * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | |
102 | * | Cookie (optional, maximum 64 bits)... | |
103 | * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | |
104 | * | | |
105 | * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | |
106 | * | |
107 | * L2TPv3 Control Message Header Over IP | |
108 | * | |
109 | * 0 1 2 3 | |
110 | * 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 | |
111 | * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | |
112 | * | (32 bits of zeros) | | |
113 | * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | |
114 | * |T|L|x|x|S|x|x|x|x|x|x|x| Ver | Length | | |
115 | * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | |
116 | * | Control Connection ID | | |
117 | * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | |
118 | * | Ns | Nr | | |
119 | * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | |
120 | * | |
121 | * All control frames are passed to userspace. | |
122 | */ | |
123 | static int l2tp_ip6_recv(struct sk_buff *skb) | |
124 | { | |
0e6b5259 | 125 | struct net *net = dev_net(skb->dev); |
a32e0eec CE |
126 | struct sock *sk; |
127 | u32 session_id; | |
128 | u32 tunnel_id; | |
129 | unsigned char *ptr, *optr; | |
130 | struct l2tp_session *session; | |
131 | struct l2tp_tunnel *tunnel = NULL; | |
8f7dc9ae | 132 | struct ipv6hdr *iph; |
a32e0eec | 133 | |
a32e0eec CE |
134 | if (!pskb_may_pull(skb, 4)) |
135 | goto discard; | |
136 | ||
be447f30 | 137 | /* Point to L2TP header */ |
95075150 TP |
138 | optr = skb->data; |
139 | ptr = skb->data; | |
b71a61cc | 140 | session_id = ntohl(*((__be32 *)ptr)); |
a32e0eec CE |
141 | ptr += 4; |
142 | ||
143 | /* RFC3931: L2TP/IP packets have the first 4 bytes containing | |
144 | * the session_id. If it is 0, the packet is a L2TP control | |
145 | * frame and the session_id value can be discarded. | |
146 | */ | |
147 | if (session_id == 0) { | |
148 | __skb_pull(skb, 4); | |
149 | goto pass_up; | |
150 | } | |
151 | ||
152 | /* Ok, this is a data packet. Lookup the session. */ | |
01e28b92 | 153 | session = l2tp_session_get(net, session_id); |
61b9a047 | 154 | if (!session) |
a32e0eec CE |
155 | goto discard; |
156 | ||
157 | tunnel = session->tunnel; | |
61b9a047 GN |
158 | if (!tunnel) |
159 | goto discard_sess; | |
a32e0eec | 160 | |
4522a70d JW |
161 | if (l2tp_v3_ensure_opt_in_linear(session, skb, &ptr, &optr)) |
162 | goto discard_sess; | |
163 | ||
2b139e6b | 164 | l2tp_recv_common(session, skb, ptr, optr, 0, skb->len); |
61b9a047 GN |
165 | l2tp_session_dec_refcount(session); |
166 | ||
a32e0eec CE |
167 | return 0; |
168 | ||
169 | pass_up: | |
170 | /* Get the tunnel_id from the L2TP header */ | |
171 | if (!pskb_may_pull(skb, 12)) | |
172 | goto discard; | |
173 | ||
174 | if ((skb->data[0] & 0xc0) != 0xc0) | |
175 | goto discard; | |
176 | ||
b71a61cc | 177 | tunnel_id = ntohl(*(__be32 *)&skb->data[4]); |
8f7dc9ae GN |
178 | iph = ipv6_hdr(skb); |
179 | ||
180 | read_lock_bh(&l2tp_ip6_lock); | |
181 | sk = __l2tp_ip6_bind_lookup(net, &iph->daddr, &iph->saddr, | |
182 | inet6_iif(skb), tunnel_id); | |
183 | if (!sk) { | |
a32e0eec | 184 | read_unlock_bh(&l2tp_ip6_lock); |
8f7dc9ae | 185 | goto discard; |
a32e0eec | 186 | } |
8f7dc9ae GN |
187 | sock_hold(sk); |
188 | read_unlock_bh(&l2tp_ip6_lock); | |
a32e0eec | 189 | |
a32e0eec CE |
190 | if (!xfrm6_policy_check(sk, XFRM_POLICY_IN, skb)) |
191 | goto discard_put; | |
192 | ||
895b5c9f | 193 | nf_reset_ct(skb); |
a32e0eec CE |
194 | |
195 | return sk_receive_skb(sk, skb, 1); | |
196 | ||
61b9a047 | 197 | discard_sess: |
61b9a047 GN |
198 | l2tp_session_dec_refcount(session); |
199 | goto discard; | |
200 | ||
a32e0eec CE |
201 | discard_put: |
202 | sock_put(sk); | |
203 | ||
204 | discard: | |
205 | kfree_skb(skb); | |
206 | return 0; | |
207 | } | |
208 | ||
02c71b14 | 209 | static int l2tp_ip6_hash(struct sock *sk) |
a32e0eec | 210 | { |
02c71b14 ED |
211 | if (sk_unhashed(sk)) { |
212 | write_lock_bh(&l2tp_ip6_lock); | |
213 | sk_add_node(sk, &l2tp_ip6_table); | |
214 | write_unlock_bh(&l2tp_ip6_lock); | |
215 | } | |
216 | return 0; | |
217 | } | |
a32e0eec | 218 | |
02c71b14 ED |
219 | static void l2tp_ip6_unhash(struct sock *sk) |
220 | { | |
221 | if (sk_unhashed(sk)) | |
222 | return; | |
a32e0eec | 223 | write_lock_bh(&l2tp_ip6_lock); |
02c71b14 | 224 | sk_del_node_init(sk); |
a32e0eec | 225 | write_unlock_bh(&l2tp_ip6_lock); |
02c71b14 ED |
226 | } |
227 | ||
228 | static int l2tp_ip6_open(struct sock *sk) | |
229 | { | |
230 | /* Prevent autobind. We don't have ports. */ | |
231 | inet_sk(sk)->inet_num = IPPROTO_L2TP; | |
a32e0eec | 232 | |
02c71b14 | 233 | l2tp_ip6_hash(sk); |
a32e0eec CE |
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 | { | |
45faeff1 | 249 | struct l2tp_tunnel *tunnel = l2tp_sk_to_tunnel(sk); |
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); | |
a32e0eec CE |
257 | } |
258 | ||
259 | static int l2tp_ip6_bind(struct sock *sk, struct sockaddr *uaddr, int addr_len) | |
260 | { | |
261 | struct inet_sock *inet = inet_sk(sk); | |
262 | struct ipv6_pinfo *np = inet6_sk(sk); | |
b71a61cc | 263 | struct sockaddr_l2tpip6 *addr = (struct sockaddr_l2tpip6 *)uaddr; |
0e6b5259 | 264 | struct net *net = sock_net(sk); |
a32e0eec | 265 | __be32 v4addr = 0; |
d5e3a190 | 266 | int bound_dev_if; |
a32e0eec CE |
267 | int addr_type; |
268 | int err; | |
269 | ||
c51ce497 JC |
270 | if (addr->l2tp_family != AF_INET6) |
271 | return -EINVAL; | |
a32e0eec CE |
272 | if (addr_len < sizeof(*addr)) |
273 | return -EINVAL; | |
274 | ||
275 | addr_type = ipv6_addr_type(&addr->l2tp_addr); | |
276 | ||
277 | /* l2tp_ip6 sockets are IPv6 only */ | |
278 | if (addr_type == IPV6_ADDR_MAPPED) | |
279 | return -EADDRNOTAVAIL; | |
280 | ||
281 | /* L2TP is point-point, not multicast */ | |
282 | if (addr_type & IPV6_ADDR_MULTICAST) | |
283 | return -EADDRNOTAVAIL; | |
284 | ||
a32e0eec CE |
285 | lock_sock(sk); |
286 | ||
287 | err = -EINVAL; | |
32c23116 GN |
288 | if (!sock_flag(sk, SOCK_ZAPPED)) |
289 | goto out_unlock; | |
290 | ||
a32e0eec CE |
291 | if (sk->sk_state != TCP_CLOSE) |
292 | goto out_unlock; | |
293 | ||
d5e3a190 GN |
294 | bound_dev_if = sk->sk_bound_dev_if; |
295 | ||
a32e0eec CE |
296 | /* Check if the address belongs to the host. */ |
297 | rcu_read_lock(); | |
298 | if (addr_type != IPV6_ADDR_ANY) { | |
299 | struct net_device *dev = NULL; | |
300 | ||
301 | if (addr_type & IPV6_ADDR_LINKLOCAL) { | |
d5e3a190 GN |
302 | if (addr->l2tp_scope_id) |
303 | bound_dev_if = addr->l2tp_scope_id; | |
a32e0eec CE |
304 | |
305 | /* Binding to link-local address requires an | |
d5e3a190 GN |
306 | * interface. |
307 | */ | |
308 | if (!bound_dev_if) | |
a32e0eec CE |
309 | goto out_unlock_rcu; |
310 | ||
311 | err = -ENODEV; | |
d5e3a190 | 312 | dev = dev_get_by_index_rcu(sock_net(sk), bound_dev_if); |
a32e0eec CE |
313 | if (!dev) |
314 | goto out_unlock_rcu; | |
315 | } | |
316 | ||
317 | /* ipv4 addr of the socket is invalid. Only the | |
318 | * unspecified and mapped address have a v4 equivalent. | |
319 | */ | |
320 | v4addr = LOOPBACK4_IPV6; | |
321 | err = -EADDRNOTAVAIL; | |
322 | if (!ipv6_chk_addr(sock_net(sk), &addr->l2tp_addr, dev, 0)) | |
323 | goto out_unlock_rcu; | |
324 | } | |
325 | rcu_read_unlock(); | |
326 | ||
d5e3a190 | 327 | write_lock_bh(&l2tp_ip6_lock); |
a9b2dff8 | 328 | if (__l2tp_ip6_bind_lookup(net, &addr->l2tp_addr, NULL, bound_dev_if, |
d5e3a190 GN |
329 | addr->l2tp_conn_id)) { |
330 | write_unlock_bh(&l2tp_ip6_lock); | |
331 | err = -EADDRINUSE; | |
332 | goto out_unlock; | |
333 | } | |
334 | ||
335 | inet->inet_saddr = v4addr; | |
336 | inet->inet_rcv_saddr = v4addr; | |
337 | sk->sk_bound_dev_if = bound_dev_if; | |
efe4208f | 338 | sk->sk_v6_rcv_saddr = addr->l2tp_addr; |
a32e0eec CE |
339 | np->saddr = addr->l2tp_addr; |
340 | ||
341 | l2tp_ip6_sk(sk)->conn_id = addr->l2tp_conn_id; | |
342 | ||
a32e0eec CE |
343 | sk_add_bind_node(sk, &l2tp_ip6_bind_table); |
344 | sk_del_node_init(sk); | |
345 | write_unlock_bh(&l2tp_ip6_lock); | |
346 | ||
c51ce497 | 347 | sock_reset_flag(sk, SOCK_ZAPPED); |
a32e0eec CE |
348 | release_sock(sk); |
349 | return 0; | |
350 | ||
351 | out_unlock_rcu: | |
352 | rcu_read_unlock(); | |
353 | out_unlock: | |
354 | release_sock(sk); | |
a32e0eec | 355 | |
a32e0eec CE |
356 | return err; |
357 | } | |
358 | ||
359 | static int l2tp_ip6_connect(struct sock *sk, struct sockaddr *uaddr, | |
360 | int addr_len) | |
361 | { | |
b71a61cc TP |
362 | struct sockaddr_l2tpip6 *lsa = (struct sockaddr_l2tpip6 *)uaddr; |
363 | struct sockaddr_in6 *usin = (struct sockaddr_in6 *)uaddr; | |
a32e0eec CE |
364 | struct in6_addr *daddr; |
365 | int addr_type; | |
366 | int rc; | |
367 | ||
368 | if (addr_len < sizeof(*lsa)) | |
369 | return -EINVAL; | |
370 | ||
82b276cd HFS |
371 | if (usin->sin6_family != AF_INET6) |
372 | return -EINVAL; | |
373 | ||
a32e0eec CE |
374 | addr_type = ipv6_addr_type(&usin->sin6_addr); |
375 | if (addr_type & IPV6_ADDR_MULTICAST) | |
376 | return -EINVAL; | |
377 | ||
378 | if (addr_type & IPV6_ADDR_MAPPED) { | |
379 | daddr = &usin->sin6_addr; | |
380 | if (ipv4_is_multicast(daddr->s6_addr32[3])) | |
381 | return -EINVAL; | |
382 | } | |
383 | ||
a32e0eec CE |
384 | lock_sock(sk); |
385 | ||
0382a25a GN |
386 | /* Must bind first - autobinding does not work */ |
387 | if (sock_flag(sk, SOCK_ZAPPED)) { | |
388 | rc = -EINVAL; | |
389 | goto out_sk; | |
390 | } | |
391 | ||
392 | rc = __ip6_datagram_connect(sk, uaddr, addr_len); | |
393 | if (rc < 0) | |
394 | goto out_sk; | |
395 | ||
a32e0eec CE |
396 | l2tp_ip6_sk(sk)->peer_conn_id = lsa->l2tp_conn_id; |
397 | ||
398 | write_lock_bh(&l2tp_ip6_lock); | |
399 | hlist_del_init(&sk->sk_bind_node); | |
400 | sk_add_bind_node(sk, &l2tp_ip6_bind_table); | |
401 | write_unlock_bh(&l2tp_ip6_lock); | |
402 | ||
0382a25a | 403 | out_sk: |
a32e0eec CE |
404 | release_sock(sk); |
405 | ||
406 | return rc; | |
407 | } | |
408 | ||
c51ce497 JC |
409 | static int l2tp_ip6_disconnect(struct sock *sk, int flags) |
410 | { | |
411 | if (sock_flag(sk, SOCK_ZAPPED)) | |
412 | return 0; | |
413 | ||
286c72de | 414 | return __udp_disconnect(sk, flags); |
c51ce497 JC |
415 | } |
416 | ||
a32e0eec | 417 | static int l2tp_ip6_getname(struct socket *sock, struct sockaddr *uaddr, |
9b2c45d4 | 418 | int peer) |
a32e0eec CE |
419 | { |
420 | struct sockaddr_l2tpip6 *lsa = (struct sockaddr_l2tpip6 *)uaddr; | |
421 | struct sock *sk = sock->sk; | |
422 | struct ipv6_pinfo *np = inet6_sk(sk); | |
423 | struct l2tp_ip6_sock *lsk = l2tp_ip6_sk(sk); | |
424 | ||
425 | lsa->l2tp_family = AF_INET6; | |
426 | lsa->l2tp_flowinfo = 0; | |
427 | lsa->l2tp_scope_id = 0; | |
04d4fbca | 428 | lsa->l2tp_unused = 0; |
a32e0eec CE |
429 | if (peer) { |
430 | if (!lsk->peer_conn_id) | |
431 | return -ENOTCONN; | |
432 | lsa->l2tp_conn_id = lsk->peer_conn_id; | |
efe4208f | 433 | lsa->l2tp_addr = sk->sk_v6_daddr; |
859f8b26 | 434 | if (inet6_test_bit(SNDFLOW, sk)) |
a32e0eec CE |
435 | lsa->l2tp_flowinfo = np->flow_label; |
436 | } else { | |
efe4208f | 437 | if (ipv6_addr_any(&sk->sk_v6_rcv_saddr)) |
a32e0eec CE |
438 | lsa->l2tp_addr = np->saddr; |
439 | else | |
efe4208f | 440 | lsa->l2tp_addr = sk->sk_v6_rcv_saddr; |
a32e0eec CE |
441 | |
442 | lsa->l2tp_conn_id = lsk->conn_id; | |
443 | } | |
444 | if (ipv6_addr_type(&lsa->l2tp_addr) & IPV6_ADDR_LINKLOCAL) | |
ff009403 | 445 | lsa->l2tp_scope_id = READ_ONCE(sk->sk_bound_dev_if); |
9b2c45d4 | 446 | return sizeof(*lsa); |
a32e0eec CE |
447 | } |
448 | ||
449 | static int l2tp_ip6_backlog_recv(struct sock *sk, struct sk_buff *skb) | |
450 | { | |
451 | int rc; | |
452 | ||
453 | /* Charge it to the socket, dropping if the queue is full. */ | |
454 | rc = sock_queue_rcv_skb(sk, skb); | |
455 | if (rc < 0) | |
456 | goto drop; | |
457 | ||
458 | return 0; | |
459 | ||
460 | drop: | |
0e6b5259 | 461 | IP_INC_STATS(sock_net(sk), IPSTATS_MIB_INDISCARDS); |
a32e0eec CE |
462 | kfree_skb(skb); |
463 | return -1; | |
464 | } | |
465 | ||
466 | static int l2tp_ip6_push_pending_frames(struct sock *sk) | |
467 | { | |
468 | struct sk_buff *skb; | |
469 | __be32 *transhdr = NULL; | |
470 | int err = 0; | |
471 | ||
472 | skb = skb_peek(&sk->sk_write_queue); | |
0febc7b3 | 473 | if (!skb) |
a32e0eec CE |
474 | goto out; |
475 | ||
476 | transhdr = (__be32 *)skb_transport_header(skb); | |
477 | *transhdr = 0; | |
478 | ||
479 | err = ip6_push_pending_frames(sk); | |
480 | ||
481 | out: | |
482 | return err; | |
483 | } | |
484 | ||
485 | /* Userspace will call sendmsg() on the tunnel socket to send L2TP | |
486 | * control frames. | |
487 | */ | |
1b784140 | 488 | static int l2tp_ip6_sendmsg(struct sock *sk, struct msghdr *msg, size_t len) |
a32e0eec CE |
489 | { |
490 | struct ipv6_txoptions opt_space; | |
342dfc30 | 491 | DECLARE_SOCKADDR(struct sockaddr_l2tpip6 *, lsa, msg->msg_name); |
a32e0eec CE |
492 | struct in6_addr *daddr, *final_p, final; |
493 | struct ipv6_pinfo *np = inet6_sk(sk); | |
45f6fad8 | 494 | struct ipv6_txoptions *opt_to_free = NULL; |
a32e0eec CE |
495 | struct ipv6_txoptions *opt = NULL; |
496 | struct ip6_flowlabel *flowlabel = NULL; | |
497 | struct dst_entry *dst = NULL; | |
498 | struct flowi6 fl6; | |
26879da5 | 499 | struct ipcm6_cookie ipc6; |
a32e0eec | 500 | int addr_len = msg->msg_namelen; |
a32e0eec | 501 | int transhdrlen = 4; /* zero session-id */ |
f638a84a | 502 | int ulen; |
a32e0eec CE |
503 | int err; |
504 | ||
505 | /* Rough check on arithmetic overflow, | |
20dcb110 | 506 | * better check is made in ip6_append_data(). |
a32e0eec | 507 | */ |
f638a84a | 508 | if (len > INT_MAX - transhdrlen) |
a32e0eec CE |
509 | return -EMSGSIZE; |
510 | ||
511 | /* Mirror BSD error message compatibility */ | |
512 | if (msg->msg_flags & MSG_OOB) | |
513 | return -EOPNOTSUPP; | |
514 | ||
20dcb110 | 515 | /* Get and verify the address */ |
a32e0eec CE |
516 | memset(&fl6, 0, sizeof(fl6)); |
517 | ||
3c5b4d69 | 518 | fl6.flowi6_mark = READ_ONCE(sk->sk_mark); |
e2d118a1 | 519 | fl6.flowi6_uid = sk->sk_uid; |
a32e0eec | 520 | |
b515430a | 521 | ipcm6_init(&ipc6); |
26879da5 | 522 | |
a32e0eec CE |
523 | if (lsa) { |
524 | if (addr_len < SIN6_LEN_RFC2133) | |
525 | return -EINVAL; | |
526 | ||
527 | if (lsa->l2tp_family && lsa->l2tp_family != AF_INET6) | |
528 | return -EAFNOSUPPORT; | |
529 | ||
530 | daddr = &lsa->l2tp_addr; | |
859f8b26 | 531 | if (inet6_test_bit(SNDFLOW, sk)) { |
a32e0eec | 532 | fl6.flowlabel = lsa->l2tp_flowinfo & IPV6_FLOWINFO_MASK; |
b71a61cc | 533 | if (fl6.flowlabel & IPV6_FLOWLABEL_MASK) { |
a32e0eec | 534 | flowlabel = fl6_sock_lookup(sk, fl6.flowlabel); |
59c820b2 | 535 | if (IS_ERR(flowlabel)) |
a32e0eec | 536 | return -EINVAL; |
a32e0eec CE |
537 | } |
538 | } | |
539 | ||
20dcb110 | 540 | /* Otherwise it will be difficult to maintain |
a32e0eec CE |
541 | * sk->sk_dst_cache. |
542 | */ | |
543 | if (sk->sk_state == TCP_ESTABLISHED && | |
efe4208f ED |
544 | ipv6_addr_equal(daddr, &sk->sk_v6_daddr)) |
545 | daddr = &sk->sk_v6_daddr; | |
a32e0eec CE |
546 | |
547 | if (addr_len >= sizeof(struct sockaddr_in6) && | |
548 | lsa->l2tp_scope_id && | |
549 | ipv6_addr_type(daddr) & IPV6_ADDR_LINKLOCAL) | |
550 | fl6.flowi6_oif = lsa->l2tp_scope_id; | |
551 | } else { | |
552 | if (sk->sk_state != TCP_ESTABLISHED) | |
553 | return -EDESTADDRREQ; | |
554 | ||
efe4208f | 555 | daddr = &sk->sk_v6_daddr; |
a32e0eec CE |
556 | fl6.flowlabel = np->flow_label; |
557 | } | |
558 | ||
559 | if (fl6.flowi6_oif == 0) | |
ff009403 | 560 | fl6.flowi6_oif = READ_ONCE(sk->sk_bound_dev_if); |
a32e0eec CE |
561 | |
562 | if (msg->msg_controllen) { | |
563 | opt = &opt_space; | |
564 | memset(opt, 0, sizeof(struct ipv6_txoptions)); | |
565 | opt->tot_len = sizeof(struct ipv6_txoptions); | |
26879da5 | 566 | ipc6.opt = opt; |
a32e0eec | 567 | |
5fdaa88d | 568 | err = ip6_datagram_send_ctl(sock_net(sk), sk, msg, &fl6, &ipc6); |
26879da5 | 569 | if (err < 0) { |
a32e0eec CE |
570 | fl6_sock_release(flowlabel); |
571 | return err; | |
572 | } | |
573 | if ((fl6.flowlabel & IPV6_FLOWLABEL_MASK) && !flowlabel) { | |
574 | flowlabel = fl6_sock_lookup(sk, fl6.flowlabel); | |
59c820b2 | 575 | if (IS_ERR(flowlabel)) |
a32e0eec CE |
576 | return -EINVAL; |
577 | } | |
b71a61cc | 578 | if (!(opt->opt_nflen | opt->opt_flen)) |
a32e0eec CE |
579 | opt = NULL; |
580 | } | |
581 | ||
45f6fad8 ED |
582 | if (!opt) { |
583 | opt = txopt_get(np); | |
584 | opt_to_free = opt; | |
585 | } | |
a32e0eec CE |
586 | if (flowlabel) |
587 | opt = fl6_merge_options(&opt_space, flowlabel, opt); | |
588 | opt = ipv6_fixup_options(&opt_space, opt); | |
26879da5 | 589 | ipc6.opt = opt; |
a32e0eec CE |
590 | |
591 | fl6.flowi6_proto = sk->sk_protocol; | |
592 | if (!ipv6_addr_any(daddr)) | |
593 | fl6.daddr = *daddr; | |
594 | else | |
595 | fl6.daddr.s6_addr[15] = 0x1; /* :: means loopback (BSD'ism) */ | |
596 | if (ipv6_addr_any(&fl6.saddr) && !ipv6_addr_any(&np->saddr)) | |
597 | fl6.saddr = np->saddr; | |
598 | ||
599 | final_p = fl6_update_dst(&fl6, opt, &final); | |
600 | ||
601 | if (!fl6.flowi6_oif && ipv6_addr_is_multicast(&fl6.daddr)) | |
d2f011a0 | 602 | fl6.flowi6_oif = READ_ONCE(np->mcast_oif); |
a32e0eec | 603 | else if (!fl6.flowi6_oif) |
1ac13efd | 604 | fl6.flowi6_oif = READ_ONCE(np->ucast_oif); |
a32e0eec | 605 | |
3df98d79 | 606 | security_sk_classify_flow(sk, flowi6_to_flowi_common(&fl6)); |
a32e0eec | 607 | |
38b7097b HFS |
608 | if (ipc6.tclass < 0) |
609 | ipc6.tclass = np->tclass; | |
610 | ||
611 | fl6.flowlabel = ip6_make_flowinfo(ipc6.tclass, fl6.flowlabel); | |
612 | ||
c4e85f73 | 613 | dst = ip6_dst_lookup_flow(sock_net(sk), sk, &fl6, final_p); |
a32e0eec CE |
614 | if (IS_ERR(dst)) { |
615 | err = PTR_ERR(dst); | |
616 | goto out; | |
617 | } | |
618 | ||
26879da5 WW |
619 | if (ipc6.hlimit < 0) |
620 | ipc6.hlimit = ip6_sk_dst_hoplimit(np, &fl6, dst); | |
a32e0eec | 621 | |
26879da5 | 622 | if (ipc6.dontfrag < 0) |
1086ca7c | 623 | ipc6.dontfrag = inet6_test_bit(DONTFRAG, sk); |
a32e0eec CE |
624 | |
625 | if (msg->msg_flags & MSG_CONFIRM) | |
626 | goto do_confirm; | |
627 | ||
628 | back_from_confirm: | |
629 | lock_sock(sk); | |
359e54a9 | 630 | ulen = len + (skb_queue_empty(&sk->sk_write_queue) ? transhdrlen : 0); |
f69e6d13 | 631 | err = ip6_append_data(sk, ip_generic_getfrag, msg, |
26879da5 | 632 | ulen, transhdrlen, &ipc6, |
e8dfd42c | 633 | &fl6, dst_rt6_info(dst), |
5fdaa88d | 634 | msg->msg_flags); |
a32e0eec CE |
635 | if (err) |
636 | ip6_flush_pending_frames(sk); | |
637 | else if (!(msg->msg_flags & MSG_MORE)) | |
638 | err = l2tp_ip6_push_pending_frames(sk); | |
639 | release_sock(sk); | |
640 | done: | |
641 | dst_release(dst); | |
642 | out: | |
643 | fl6_sock_release(flowlabel); | |
45f6fad8 | 644 | txopt_put(opt_to_free); |
a32e0eec CE |
645 | |
646 | return err < 0 ? err : len; | |
647 | ||
648 | do_confirm: | |
0dec879f JA |
649 | if (msg->msg_flags & MSG_PROBE) |
650 | dst_confirm_neigh(dst, &fl6.daddr); | |
a32e0eec CE |
651 | if (!(msg->msg_flags & MSG_PROBE) || len) |
652 | goto back_from_confirm; | |
653 | err = 0; | |
654 | goto done; | |
655 | } | |
656 | ||
1b784140 | 657 | static int l2tp_ip6_recvmsg(struct sock *sk, struct msghdr *msg, size_t len, |
ec095263 | 658 | int flags, int *addr_len) |
a32e0eec | 659 | { |
700163db | 660 | struct ipv6_pinfo *np = inet6_sk(sk); |
342dfc30 | 661 | DECLARE_SOCKADDR(struct sockaddr_l2tpip6 *, lsa, msg->msg_name); |
a32e0eec CE |
662 | size_t copied = 0; |
663 | int err = -EOPNOTSUPP; | |
664 | struct sk_buff *skb; | |
665 | ||
666 | if (flags & MSG_OOB) | |
667 | goto out; | |
668 | ||
a32e0eec | 669 | if (flags & MSG_ERRQUEUE) |
85fbaa75 | 670 | return ipv6_recv_error(sk, msg, len, addr_len); |
a32e0eec | 671 | |
f4b41f06 | 672 | skb = skb_recv_datagram(sk, flags, &err); |
a32e0eec CE |
673 | if (!skb) |
674 | goto out; | |
675 | ||
676 | copied = skb->len; | |
677 | if (len < copied) { | |
678 | msg->msg_flags |= MSG_TRUNC; | |
679 | copied = len; | |
680 | } | |
681 | ||
51f3d02b | 682 | err = skb_copy_datagram_msg(skb, 0, msg, copied); |
a32e0eec CE |
683 | if (err) |
684 | goto done; | |
685 | ||
686 | sock_recv_timestamp(msg, sk, skb); | |
687 | ||
688 | /* Copy the address. */ | |
689 | if (lsa) { | |
690 | lsa->l2tp_family = AF_INET6; | |
691 | lsa->l2tp_unused = 0; | |
692 | lsa->l2tp_addr = ipv6_hdr(skb)->saddr; | |
693 | lsa->l2tp_flowinfo = 0; | |
694 | lsa->l2tp_scope_id = 0; | |
b860d3cc | 695 | lsa->l2tp_conn_id = 0; |
a32e0eec | 696 | if (ipv6_addr_type(&lsa->l2tp_addr) & IPV6_ADDR_LINKLOCAL) |
4330487a | 697 | lsa->l2tp_scope_id = inet6_iif(skb); |
163d1c3d | 698 | *addr_len = sizeof(*lsa); |
a32e0eec CE |
699 | } |
700 | ||
700163db TP |
701 | if (np->rxopt.all) |
702 | ip6_datagram_recv_ctl(sk, msg, skb); | |
a32e0eec CE |
703 | |
704 | if (flags & MSG_TRUNC) | |
705 | copied = skb->len; | |
706 | done: | |
707 | skb_free_datagram(sk, skb); | |
708 | out: | |
709 | return err ? err : copied; | |
710 | } | |
711 | ||
712 | static struct proto l2tp_ip6_prot = { | |
713 | .name = "L2TP/IPv6", | |
714 | .owner = THIS_MODULE, | |
715 | .init = l2tp_ip6_open, | |
716 | .close = l2tp_ip6_close, | |
717 | .bind = l2tp_ip6_bind, | |
718 | .connect = l2tp_ip6_connect, | |
c51ce497 | 719 | .disconnect = l2tp_ip6_disconnect, |
72fb96e7 | 720 | .ioctl = l2tp_ioctl, |
a32e0eec CE |
721 | .destroy = l2tp_ip6_destroy_sock, |
722 | .setsockopt = ipv6_setsockopt, | |
723 | .getsockopt = ipv6_getsockopt, | |
724 | .sendmsg = l2tp_ip6_sendmsg, | |
725 | .recvmsg = l2tp_ip6_recvmsg, | |
726 | .backlog_rcv = l2tp_ip6_backlog_recv, | |
02c71b14 ED |
727 | .hash = l2tp_ip6_hash, |
728 | .unhash = l2tp_ip6_unhash, | |
a32e0eec | 729 | .obj_size = sizeof(struct l2tp_ip6_sock), |
f5f80e32 | 730 | .ipv6_pinfo_offset = offsetof(struct l2tp_ip6_sock, inet6), |
a32e0eec CE |
731 | }; |
732 | ||
733 | static const struct proto_ops l2tp_ip6_ops = { | |
734 | .family = PF_INET6, | |
735 | .owner = THIS_MODULE, | |
736 | .release = inet6_release, | |
737 | .bind = inet6_bind, | |
738 | .connect = inet_dgram_connect, | |
739 | .socketpair = sock_no_socketpair, | |
740 | .accept = sock_no_accept, | |
741 | .getname = l2tp_ip6_getname, | |
a11e1d43 | 742 | .poll = datagram_poll, |
a32e0eec | 743 | .ioctl = inet6_ioctl, |
c7cbdbf2 | 744 | .gettstamp = sock_gettstamp, |
a32e0eec CE |
745 | .listen = sock_no_listen, |
746 | .shutdown = inet_shutdown, | |
747 | .setsockopt = sock_common_setsockopt, | |
748 | .getsockopt = sock_common_getsockopt, | |
749 | .sendmsg = inet_sendmsg, | |
750 | .recvmsg = sock_common_recvmsg, | |
751 | .mmap = sock_no_mmap, | |
a32e0eec | 752 | #ifdef CONFIG_COMPAT |
3986912f | 753 | .compat_ioctl = inet6_compat_ioctl, |
a32e0eec CE |
754 | #endif |
755 | }; | |
756 | ||
757 | static struct inet_protosw l2tp_ip6_protosw = { | |
758 | .type = SOCK_DGRAM, | |
759 | .protocol = IPPROTO_L2TP, | |
760 | .prot = &l2tp_ip6_prot, | |
761 | .ops = &l2tp_ip6_ops, | |
a32e0eec CE |
762 | }; |
763 | ||
764 | static struct inet6_protocol l2tp_ip6_protocol __read_mostly = { | |
765 | .handler = l2tp_ip6_recv, | |
766 | }; | |
767 | ||
768 | static int __init l2tp_ip6_init(void) | |
769 | { | |
770 | int err; | |
771 | ||
a4ca44fa | 772 | pr_info("L2TP IP encapsulation support for IPv6 (L2TPv3)\n"); |
a32e0eec CE |
773 | |
774 | err = proto_register(&l2tp_ip6_prot, 1); | |
775 | if (err != 0) | |
776 | goto out; | |
777 | ||
778 | err = inet6_add_protocol(&l2tp_ip6_protocol, IPPROTO_L2TP); | |
779 | if (err) | |
780 | goto out1; | |
781 | ||
782 | inet6_register_protosw(&l2tp_ip6_protosw); | |
783 | return 0; | |
784 | ||
785 | out1: | |
786 | proto_unregister(&l2tp_ip6_prot); | |
787 | out: | |
788 | return err; | |
789 | } | |
790 | ||
791 | static void __exit l2tp_ip6_exit(void) | |
792 | { | |
793 | inet6_unregister_protosw(&l2tp_ip6_protosw); | |
794 | inet6_del_protocol(&l2tp_ip6_protocol, IPPROTO_L2TP); | |
795 | proto_unregister(&l2tp_ip6_prot); | |
796 | } | |
797 | ||
798 | module_init(l2tp_ip6_init); | |
799 | module_exit(l2tp_ip6_exit); | |
800 | ||
801 | MODULE_LICENSE("GPL"); | |
802 | MODULE_AUTHOR("Chris Elston <celston@katalix.com>"); | |
803 | MODULE_DESCRIPTION("L2TP IP encapsulation for IPv6"); | |
804 | MODULE_VERSION("1.0"); | |
805 | ||
154e07c1 AR |
806 | /* Use the values of SOCK_DGRAM (2) as type and IPPROTO_L2TP (115) as protocol, |
807 | * because __stringify doesn't like enums | |
a32e0eec | 808 | */ |
154e07c1 AR |
809 | MODULE_ALIAS_NET_PF_PROTO_TYPE(PF_INET6, 115, 2); |
810 | MODULE_ALIAS_NET_PF_PROTO(PF_INET6, 115); |