1 | // SPDX-License-Identifier: GPL-2.0-or-later |
2 | /* L2TPv3 IP encapsulation support for IPv6 |
3 | * |
4 | * Copyright (c) 2012 Katalix Systems Ltd |
5 | */ |
6 | |
7 | #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt |
8 | |
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> |
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 | |
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 | |
51 | static struct sock *__l2tp_ip6_bind_lookup(const struct net *net, |
52 | const struct in6_addr *laddr, |
53 | const struct in6_addr *raddr, |
54 | int dif, u32 tunnel_id) |
55 | { |
56 | struct sock *sk; |
57 | |
58 | sk_for_each_bound(sk, &l2tp_ip6_bind_table) { |
59 | const struct in6_addr *sk_laddr = inet6_rcv_saddr(sk); |
60 | const struct in6_addr *sk_raddr = &sk->sk_v6_daddr; |
61 | const struct l2tp_ip6_sock *l2tp = l2tp_ip6_sk(sk); |
62 | int bound_dev_if; |
63 | |
64 | if (!net_eq(net1: sock_net(sk), net2: net)) |
65 | continue; |
66 | |
67 | bound_dev_if = READ_ONCE(sk->sk_bound_dev_if); |
68 | if (bound_dev_if && dif && bound_dev_if != dif) |
69 | continue; |
70 | |
71 | if (sk_laddr && !ipv6_addr_any(a: sk_laddr) && |
72 | !ipv6_addr_any(a: laddr) && !ipv6_addr_equal(a1: sk_laddr, a2: laddr)) |
73 | continue; |
74 | |
75 | if (!ipv6_addr_any(a: sk_raddr) && raddr && |
76 | !ipv6_addr_any(a: raddr) && !ipv6_addr_equal(a1: sk_raddr, a2: raddr)) |
77 | continue; |
78 | |
79 | if (l2tp->conn_id != tunnel_id) |
80 | continue; |
81 | |
82 | goto found; |
83 | } |
84 | |
85 | sk = NULL; |
86 | found: |
87 | return sk; |
88 | } |
89 | |
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 | { |
125 | struct net *net = dev_net(dev: skb->dev); |
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; |
132 | struct ipv6hdr *iph; |
133 | |
134 | if (!pskb_may_pull(skb, len: 4)) |
135 | goto discard; |
136 | |
137 | /* Point to L2TP header */ |
138 | optr = skb->data; |
139 | ptr = skb->data; |
140 | session_id = ntohl(*((__be32 *)ptr)); |
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, len: 4); |
149 | goto pass_up; |
150 | } |
151 | |
152 | /* Ok, this is a data packet. Lookup the session. */ |
153 | session = l2tp_session_get(net, session_id); |
154 | if (!session) |
155 | goto discard; |
156 | |
157 | tunnel = session->tunnel; |
158 | if (!tunnel) |
159 | goto discard_sess; |
160 | |
161 | if (l2tp_v3_ensure_opt_in_linear(session, skb, ptr: &ptr, optr: &optr)) |
162 | goto discard_sess; |
163 | |
164 | l2tp_recv_common(session, skb, ptr, optr, hdrflags: 0, length: skb->len); |
165 | l2tp_session_dec_refcount(session); |
166 | |
167 | return 0; |
168 | |
169 | pass_up: |
170 | /* Get the tunnel_id from the L2TP header */ |
171 | if (!pskb_may_pull(skb, len: 12)) |
172 | goto discard; |
173 | |
174 | if ((skb->data[0] & 0xc0) != 0xc0) |
175 | goto discard; |
176 | |
177 | tunnel_id = ntohl(*(__be32 *)&skb->data[4]); |
178 | iph = ipv6_hdr(skb); |
179 | |
180 | read_lock_bh(&l2tp_ip6_lock); |
181 | sk = __l2tp_ip6_bind_lookup(net, laddr: &iph->daddr, raddr: &iph->saddr, |
182 | dif: inet6_iif(skb), tunnel_id); |
183 | if (!sk) { |
184 | read_unlock_bh(&l2tp_ip6_lock); |
185 | goto discard; |
186 | } |
187 | sock_hold(sk); |
188 | read_unlock_bh(&l2tp_ip6_lock); |
189 | |
190 | if (!xfrm6_policy_check(sk, dir: XFRM_POLICY_IN, skb)) |
191 | goto discard_put; |
192 | |
193 | nf_reset_ct(skb); |
194 | |
195 | return sk_receive_skb(sk, skb, nested: 1); |
196 | |
197 | discard_sess: |
198 | l2tp_session_dec_refcount(session); |
199 | goto discard; |
200 | |
201 | discard_put: |
202 | sock_put(sk); |
203 | |
204 | discard: |
205 | kfree_skb(skb); |
206 | return 0; |
207 | } |
208 | |
209 | static int l2tp_ip6_hash(struct sock *sk) |
210 | { |
211 | if (sk_unhashed(sk)) { |
212 | write_lock_bh(&l2tp_ip6_lock); |
213 | sk_add_node(sk, list: &l2tp_ip6_table); |
214 | write_unlock_bh(&l2tp_ip6_lock); |
215 | } |
216 | return 0; |
217 | } |
218 | |
219 | static void l2tp_ip6_unhash(struct sock *sk) |
220 | { |
221 | if (sk_unhashed(sk)) |
222 | return; |
223 | write_lock_bh(&l2tp_ip6_lock); |
224 | sk_del_node_init(sk); |
225 | write_unlock_bh(&l2tp_ip6_lock); |
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; |
232 | |
233 | l2tp_ip6_hash(sk); |
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(n: &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 | { |
249 | struct l2tp_tunnel *tunnel = l2tp_sk_to_tunnel(sk); |
250 | |
251 | lock_sock(sk); |
252 | ip6_flush_pending_frames(sk); |
253 | release_sock(sk); |
254 | |
255 | if (tunnel) |
256 | l2tp_tunnel_delete(tunnel); |
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: sk); |
263 | struct sockaddr_l2tpip6 *addr = (struct sockaddr_l2tpip6 *)uaddr; |
264 | struct net *net = sock_net(sk); |
265 | __be32 v4addr = 0; |
266 | int bound_dev_if; |
267 | int addr_type; |
268 | int err; |
269 | |
270 | if (addr->l2tp_family != AF_INET6) |
271 | return -EINVAL; |
272 | if (addr_len < sizeof(*addr)) |
273 | return -EINVAL; |
274 | |
275 | addr_type = ipv6_addr_type(addr: &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 | |
285 | lock_sock(sk); |
286 | |
287 | err = -EINVAL; |
288 | if (!sock_flag(sk, flag: SOCK_ZAPPED)) |
289 | goto out_unlock; |
290 | |
291 | if (sk->sk_state != TCP_CLOSE) |
292 | goto out_unlock; |
293 | |
294 | bound_dev_if = sk->sk_bound_dev_if; |
295 | |
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) { |
302 | if (addr->l2tp_scope_id) |
303 | bound_dev_if = addr->l2tp_scope_id; |
304 | |
305 | /* Binding to link-local address requires an |
306 | * interface. |
307 | */ |
308 | if (!bound_dev_if) |
309 | goto out_unlock_rcu; |
310 | |
311 | err = -ENODEV; |
312 | dev = dev_get_by_index_rcu(net: sock_net(sk), ifindex: bound_dev_if); |
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(net: sock_net(sk), addr: &addr->l2tp_addr, dev, strict: 0)) |
323 | goto out_unlock_rcu; |
324 | } |
325 | rcu_read_unlock(); |
326 | |
327 | write_lock_bh(&l2tp_ip6_lock); |
328 | if (__l2tp_ip6_bind_lookup(net, laddr: &addr->l2tp_addr, NULL, dif: bound_dev_if, |
329 | tunnel_id: 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; |
338 | sk->sk_v6_rcv_saddr = addr->l2tp_addr; |
339 | np->saddr = addr->l2tp_addr; |
340 | |
341 | l2tp_ip6_sk(sk)->conn_id = addr->l2tp_conn_id; |
342 | |
343 | sk_add_bind_node(sk, list: &l2tp_ip6_bind_table); |
344 | sk_del_node_init(sk); |
345 | write_unlock_bh(&l2tp_ip6_lock); |
346 | |
347 | sock_reset_flag(sk, flag: SOCK_ZAPPED); |
348 | release_sock(sk); |
349 | return 0; |
350 | |
351 | out_unlock_rcu: |
352 | rcu_read_unlock(); |
353 | out_unlock: |
354 | release_sock(sk); |
355 | |
356 | return err; |
357 | } |
358 | |
359 | static int l2tp_ip6_connect(struct sock *sk, struct sockaddr *uaddr, |
360 | int addr_len) |
361 | { |
362 | struct sockaddr_l2tpip6 *lsa = (struct sockaddr_l2tpip6 *)uaddr; |
363 | struct sockaddr_in6 *usin = (struct sockaddr_in6 *)uaddr; |
364 | struct in6_addr *daddr; |
365 | int addr_type; |
366 | int rc; |
367 | |
368 | if (addr_len < sizeof(*lsa)) |
369 | return -EINVAL; |
370 | |
371 | if (usin->sin6_family != AF_INET6) |
372 | return -EINVAL; |
373 | |
374 | addr_type = ipv6_addr_type(addr: &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(addr: daddr->s6_addr32[3])) |
381 | return -EINVAL; |
382 | } |
383 | |
384 | lock_sock(sk); |
385 | |
386 | /* Must bind first - autobinding does not work */ |
387 | if (sock_flag(sk, flag: SOCK_ZAPPED)) { |
388 | rc = -EINVAL; |
389 | goto out_sk; |
390 | } |
391 | |
392 | rc = __ip6_datagram_connect(sk, addr: uaddr, addr_len); |
393 | if (rc < 0) |
394 | goto out_sk; |
395 | |
396 | l2tp_ip6_sk(sk)->peer_conn_id = lsa->l2tp_conn_id; |
397 | |
398 | write_lock_bh(&l2tp_ip6_lock); |
399 | hlist_del_init(n: &sk->sk_bind_node); |
400 | sk_add_bind_node(sk, list: &l2tp_ip6_bind_table); |
401 | write_unlock_bh(&l2tp_ip6_lock); |
402 | |
403 | out_sk: |
404 | release_sock(sk); |
405 | |
406 | return rc; |
407 | } |
408 | |
409 | static int l2tp_ip6_disconnect(struct sock *sk, int flags) |
410 | { |
411 | if (sock_flag(sk, flag: SOCK_ZAPPED)) |
412 | return 0; |
413 | |
414 | return __udp_disconnect(sk, flags); |
415 | } |
416 | |
417 | static int l2tp_ip6_getname(struct socket *sock, struct sockaddr *uaddr, |
418 | int peer) |
419 | { |
420 | struct sockaddr_l2tpip6 *lsa = (struct sockaddr_l2tpip6 *)uaddr; |
421 | struct sock *sk = sock->sk; |
422 | struct ipv6_pinfo *np = inet6_sk(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; |
428 | lsa->l2tp_unused = 0; |
429 | if (peer) { |
430 | if (!lsk->peer_conn_id) |
431 | return -ENOTCONN; |
432 | lsa->l2tp_conn_id = lsk->peer_conn_id; |
433 | lsa->l2tp_addr = sk->sk_v6_daddr; |
434 | if (inet6_test_bit(SNDFLOW, sk)) |
435 | lsa->l2tp_flowinfo = np->flow_label; |
436 | } else { |
437 | if (ipv6_addr_any(a: &sk->sk_v6_rcv_saddr)) |
438 | lsa->l2tp_addr = np->saddr; |
439 | else |
440 | lsa->l2tp_addr = sk->sk_v6_rcv_saddr; |
441 | |
442 | lsa->l2tp_conn_id = lsk->conn_id; |
443 | } |
444 | if (ipv6_addr_type(addr: &lsa->l2tp_addr) & IPV6_ADDR_LINKLOCAL) |
445 | lsa->l2tp_scope_id = READ_ONCE(sk->sk_bound_dev_if); |
446 | return sizeof(*lsa); |
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: |
461 | IP_INC_STATS(sock_net(sk), IPSTATS_MIB_INDISCARDS); |
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(list_: &sk->sk_write_queue); |
473 | if (!skb) |
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 | */ |
488 | static int l2tp_ip6_sendmsg(struct sock *sk, struct msghdr *msg, size_t len) |
489 | { |
490 | struct ipv6_txoptions opt_space; |
491 | DECLARE_SOCKADDR(struct sockaddr_l2tpip6 *, lsa, msg->msg_name); |
492 | struct in6_addr *daddr, *final_p, final; |
493 | struct ipv6_pinfo *np = inet6_sk(sk: sk); |
494 | struct ipv6_txoptions *opt_to_free = NULL; |
495 | struct ipv6_txoptions *opt = NULL; |
496 | struct ip6_flowlabel *flowlabel = NULL; |
497 | struct dst_entry *dst = NULL; |
498 | struct flowi6 fl6; |
499 | struct ipcm6_cookie ipc6; |
500 | int addr_len = msg->msg_namelen; |
501 | int transhdrlen = 4; /* zero session-id */ |
502 | int ulen; |
503 | int err; |
504 | |
505 | /* Rough check on arithmetic overflow, |
506 | * better check is made in ip6_append_data(). |
507 | */ |
508 | if (len > INT_MAX - transhdrlen) |
509 | return -EMSGSIZE; |
510 | |
511 | /* Mirror BSD error message compatibility */ |
512 | if (msg->msg_flags & MSG_OOB) |
513 | return -EOPNOTSUPP; |
514 | |
515 | /* Get and verify the address */ |
516 | memset(&fl6, 0, sizeof(fl6)); |
517 | |
518 | fl6.flowi6_mark = READ_ONCE(sk->sk_mark); |
519 | fl6.flowi6_uid = sk->sk_uid; |
520 | |
521 | ipcm6_init(ipc6: &ipc6); |
522 | |
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; |
531 | if (inet6_test_bit(SNDFLOW, sk)) { |
532 | fl6.flowlabel = lsa->l2tp_flowinfo & IPV6_FLOWINFO_MASK; |
533 | if (fl6.flowlabel & IPV6_FLOWLABEL_MASK) { |
534 | flowlabel = fl6_sock_lookup(sk, label: fl6.flowlabel); |
535 | if (IS_ERR(ptr: flowlabel)) |
536 | return -EINVAL; |
537 | } |
538 | } |
539 | |
540 | /* Otherwise it will be difficult to maintain |
541 | * sk->sk_dst_cache. |
542 | */ |
543 | if (sk->sk_state == TCP_ESTABLISHED && |
544 | ipv6_addr_equal(a1: daddr, a2: &sk->sk_v6_daddr)) |
545 | daddr = &sk->sk_v6_daddr; |
546 | |
547 | if (addr_len >= sizeof(struct sockaddr_in6) && |
548 | lsa->l2tp_scope_id && |
549 | ipv6_addr_type(addr: 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 | |
555 | daddr = &sk->sk_v6_daddr; |
556 | fl6.flowlabel = np->flow_label; |
557 | } |
558 | |
559 | if (fl6.flowi6_oif == 0) |
560 | fl6.flowi6_oif = READ_ONCE(sk->sk_bound_dev_if); |
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); |
566 | ipc6.opt = opt; |
567 | |
568 | err = ip6_datagram_send_ctl(net: sock_net(sk), sk, msg, fl6: &fl6, ipc6: &ipc6); |
569 | if (err < 0) { |
570 | fl6_sock_release(fl: flowlabel); |
571 | return err; |
572 | } |
573 | if ((fl6.flowlabel & IPV6_FLOWLABEL_MASK) && !flowlabel) { |
574 | flowlabel = fl6_sock_lookup(sk, label: fl6.flowlabel); |
575 | if (IS_ERR(ptr: flowlabel)) |
576 | return -EINVAL; |
577 | } |
578 | if (!(opt->opt_nflen | opt->opt_flen)) |
579 | opt = NULL; |
580 | } |
581 | |
582 | if (!opt) { |
583 | opt = txopt_get(np); |
584 | opt_to_free = opt; |
585 | } |
586 | if (flowlabel) |
587 | opt = fl6_merge_options(opt_space: &opt_space, fl: flowlabel, fopt: opt); |
588 | opt = ipv6_fixup_options(opt_space: &opt_space, opt); |
589 | ipc6.opt = opt; |
590 | |
591 | fl6.flowi6_proto = sk->sk_protocol; |
592 | if (!ipv6_addr_any(a: daddr)) |
593 | fl6.daddr = *daddr; |
594 | else |
595 | fl6.daddr.s6_addr[15] = 0x1; /* :: means loopback (BSD'ism) */ |
596 | if (ipv6_addr_any(a: &fl6.saddr) && !ipv6_addr_any(a: &np->saddr)) |
597 | fl6.saddr = np->saddr; |
598 | |
599 | final_p = fl6_update_dst(fl6: &fl6, opt, orig: &final); |
600 | |
601 | if (!fl6.flowi6_oif && ipv6_addr_is_multicast(addr: &fl6.daddr)) |
602 | fl6.flowi6_oif = np->mcast_oif; |
603 | else if (!fl6.flowi6_oif) |
604 | fl6.flowi6_oif = np->ucast_oif; |
605 | |
606 | security_sk_classify_flow(sk, flic: flowi6_to_flowi_common(fl6: &fl6)); |
607 | |
608 | if (ipc6.tclass < 0) |
609 | ipc6.tclass = np->tclass; |
610 | |
611 | fl6.flowlabel = ip6_make_flowinfo(tclass: ipc6.tclass, flowlabel: fl6.flowlabel); |
612 | |
613 | dst = ip6_dst_lookup_flow(net: sock_net(sk), sk, fl6: &fl6, final_dst: final_p); |
614 | if (IS_ERR(ptr: dst)) { |
615 | err = PTR_ERR(ptr: dst); |
616 | goto out; |
617 | } |
618 | |
619 | if (ipc6.hlimit < 0) |
620 | ipc6.hlimit = ip6_sk_dst_hoplimit(np, fl6: &fl6, dst); |
621 | |
622 | if (ipc6.dontfrag < 0) |
623 | ipc6.dontfrag = inet6_test_bit(DONTFRAG, sk); |
624 | |
625 | if (msg->msg_flags & MSG_CONFIRM) |
626 | goto do_confirm; |
627 | |
628 | back_from_confirm: |
629 | lock_sock(sk); |
630 | ulen = len + skb_queue_empty(list: &sk->sk_write_queue) ? transhdrlen : 0; |
631 | err = ip6_append_data(sk, getfrag: ip_generic_getfrag, from: msg, |
632 | length: ulen, transhdrlen, ipc6: &ipc6, |
633 | fl6: &fl6, rt: (struct rt6_info *)dst, |
634 | flags: msg->msg_flags); |
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(fl: flowlabel); |
644 | txopt_put(opt: opt_to_free); |
645 | |
646 | return err < 0 ? err : len; |
647 | |
648 | do_confirm: |
649 | if (msg->msg_flags & MSG_PROBE) |
650 | dst_confirm_neigh(dst, daddr: &fl6.daddr); |
651 | if (!(msg->msg_flags & MSG_PROBE) || len) |
652 | goto back_from_confirm; |
653 | err = 0; |
654 | goto done; |
655 | } |
656 | |
657 | static int l2tp_ip6_recvmsg(struct sock *sk, struct msghdr *msg, size_t len, |
658 | int flags, int *addr_len) |
659 | { |
660 | struct ipv6_pinfo *np = inet6_sk(sk: sk); |
661 | DECLARE_SOCKADDR(struct sockaddr_l2tpip6 *, lsa, msg->msg_name); |
662 | size_t copied = 0; |
663 | int err = -EOPNOTSUPP; |
664 | struct sk_buff *skb; |
665 | |
666 | if (flags & MSG_OOB) |
667 | goto out; |
668 | |
669 | if (flags & MSG_ERRQUEUE) |
670 | return ipv6_recv_error(sk, msg, len, addr_len); |
671 | |
672 | skb = skb_recv_datagram(sk, flags, err: &err); |
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 | |
682 | err = skb_copy_datagram_msg(from: skb, offset: 0, msg, size: copied); |
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; |
695 | lsa->l2tp_conn_id = 0; |
696 | if (ipv6_addr_type(addr: &lsa->l2tp_addr) & IPV6_ADDR_LINKLOCAL) |
697 | lsa->l2tp_scope_id = inet6_iif(skb); |
698 | *addr_len = sizeof(*lsa); |
699 | } |
700 | |
701 | if (np->rxopt.all) |
702 | ip6_datagram_recv_ctl(sk, msg, skb); |
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, |
719 | .disconnect = l2tp_ip6_disconnect, |
720 | .ioctl = l2tp_ioctl, |
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, |
727 | .hash = l2tp_ip6_hash, |
728 | .unhash = l2tp_ip6_unhash, |
729 | .obj_size = sizeof(struct l2tp_ip6_sock), |
730 | .ipv6_pinfo_offset = offsetof(struct l2tp_ip6_sock, inet6), |
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, |
742 | .poll = datagram_poll, |
743 | .ioctl = inet6_ioctl, |
744 | .gettstamp = sock_gettstamp, |
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, |
752 | #ifdef CONFIG_COMPAT |
753 | .compat_ioctl = inet6_compat_ioctl, |
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, |
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 | |
772 | pr_info("L2TP IP encapsulation support for IPv6 (L2TPv3)\n" ); |
773 | |
774 | err = proto_register(prot: &l2tp_ip6_prot, alloc_slab: 1); |
775 | if (err != 0) |
776 | goto out; |
777 | |
778 | err = inet6_add_protocol(prot: &l2tp_ip6_protocol, IPPROTO_L2TP); |
779 | if (err) |
780 | goto out1; |
781 | |
782 | inet6_register_protosw(p: &l2tp_ip6_protosw); |
783 | return 0; |
784 | |
785 | out1: |
786 | proto_unregister(prot: &l2tp_ip6_prot); |
787 | out: |
788 | return err; |
789 | } |
790 | |
791 | static void __exit l2tp_ip6_exit(void) |
792 | { |
793 | inet6_unregister_protosw(p: &l2tp_ip6_protosw); |
794 | inet6_del_protocol(prot: &l2tp_ip6_protocol, IPPROTO_L2TP); |
795 | proto_unregister(prot: &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 | |
806 | /* Use the values of SOCK_DGRAM (2) as type and IPPROTO_L2TP (115) as protocol, |
807 | * because __stringify doesn't like enums |
808 | */ |
809 | MODULE_ALIAS_NET_PF_PROTO_TYPE(PF_INET6, 115, 2); |
810 | MODULE_ALIAS_NET_PF_PROTO(PF_INET6, 115); |
811 | |