blob: 79649937ec71da6ffc70584b51ccbba6b73e391f [file] [log] [blame]
James Chapman0d767512010-04-02 06:19:00 +00001/*
2 * L2TPv3 IP encapsulation support
3 *
4 * Copyright (c) 2008,2009,2010 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
Joe Perchesa4ca44f2012-05-16 09:55:56 +000012#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
13
James Chapman0d767512010-04-02 06:19:00 +000014#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 <net/sock.h>
22#include <net/ip.h>
23#include <net/icmp.h>
24#include <net/udp.h>
25#include <net/inet_common.h>
26#include <net/inet_hashtables.h>
27#include <net/tcp_states.h>
28#include <net/protocol.h>
29#include <net/xfrm.h>
30
31#include "l2tp_core.h"
32
33struct l2tp_ip_sock {
34 /* inet_sock has to be the first member of l2tp_ip_sock */
35 struct inet_sock inet;
36
James Chapmanc8657fd2012-04-29 21:48:48 +000037 u32 conn_id;
38 u32 peer_conn_id;
James Chapman0d767512010-04-02 06:19:00 +000039};
40
41static DEFINE_RWLOCK(l2tp_ip_lock);
42static struct hlist_head l2tp_ip_table;
43static struct hlist_head l2tp_ip_bind_table;
44
45static inline struct l2tp_ip_sock *l2tp_ip_sk(const struct sock *sk)
46{
47 return (struct l2tp_ip_sock *)sk;
48}
49
50static struct sock *__l2tp_ip_bind_lookup(struct net *net, __be32 laddr, int dif, u32 tunnel_id)
51{
James Chapman0d767512010-04-02 06:19:00 +000052 struct sock *sk;
53
Sasha Levinb67bfe02013-02-27 17:06:00 -080054 sk_for_each_bound(sk, &l2tp_ip_bind_table) {
James Chapman0d767512010-04-02 06:19:00 +000055 struct inet_sock *inet = inet_sk(sk);
56 struct l2tp_ip_sock *l2tp = l2tp_ip_sk(sk);
57
58 if (l2tp == NULL)
59 continue;
60
61 if ((l2tp->conn_id == tunnel_id) &&
Eric Dumazete83726b2010-10-21 04:39:09 -070062 net_eq(sock_net(sk), net) &&
James Chapman0d767512010-04-02 06:19:00 +000063 !(inet->inet_rcv_saddr && inet->inet_rcv_saddr != laddr) &&
64 !(sk->sk_bound_dev_if && sk->sk_bound_dev_if != dif))
65 goto found;
66 }
67
68 sk = NULL;
69found:
70 return sk;
71}
72
73static inline struct sock *l2tp_ip_bind_lookup(struct net *net, __be32 laddr, int dif, u32 tunnel_id)
74{
75 struct sock *sk = __l2tp_ip_bind_lookup(net, laddr, dif, tunnel_id);
76 if (sk)
77 sock_hold(sk);
78
79 return sk;
80}
81
82/* When processing receive frames, there are two cases to
83 * consider. Data frames consist of a non-zero session-id and an
84 * optional cookie. Control frames consist of a regular L2TP header
85 * preceded by 32-bits of zeros.
86 *
87 * L2TPv3 Session Header Over IP
88 *
89 * 0 1 2 3
90 * 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
91 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
92 * | Session ID |
93 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
94 * | Cookie (optional, maximum 64 bits)...
95 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
96 * |
97 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
98 *
99 * L2TPv3 Control Message Header Over IP
100 *
101 * 0 1 2 3
102 * 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
103 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
104 * | (32 bits of zeros) |
105 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
106 * |T|L|x|x|S|x|x|x|x|x|x|x| Ver | Length |
107 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
108 * | Control Connection ID |
109 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
110 * | Ns | Nr |
111 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
112 *
113 * All control frames are passed to userspace.
114 */
115static int l2tp_ip_recv(struct sk_buff *skb)
116{
David S. Miller9d6ddb12013-02-05 14:36:02 -0500117 struct net *net = dev_net(skb->dev);
James Chapman0d767512010-04-02 06:19:00 +0000118 struct sock *sk;
119 u32 session_id;
120 u32 tunnel_id;
121 unsigned char *ptr, *optr;
122 struct l2tp_session *session;
123 struct l2tp_tunnel *tunnel = NULL;
124 int length;
James Chapman0d767512010-04-02 06:19:00 +0000125
126 /* Point to L2TP header */
127 optr = ptr = skb->data;
128
129 if (!pskb_may_pull(skb, 4))
130 goto discard;
131
132 session_id = ntohl(*((__be32 *) ptr));
133 ptr += 4;
134
135 /* RFC3931: L2TP/IP packets have the first 4 bytes containing
136 * the session_id. If it is 0, the packet is a L2TP control
137 * frame and the session_id value can be discarded.
138 */
139 if (session_id == 0) {
140 __skb_pull(skb, 4);
141 goto pass_up;
142 }
143
144 /* Ok, this is a data packet. Lookup the session. */
David S. Miller9d6ddb12013-02-05 14:36:02 -0500145 session = l2tp_session_find(net, NULL, session_id);
James Chapman0d767512010-04-02 06:19:00 +0000146 if (session == NULL)
147 goto discard;
148
149 tunnel = session->tunnel;
150 if (tunnel == NULL)
151 goto discard;
152
153 /* Trace packet contents, if enabled */
154 if (tunnel->debug & L2TP_MSG_DATA) {
155 length = min(32u, skb->len);
156 if (!pskb_may_pull(skb, length))
157 goto discard;
158
Joe Perchesa4ca44f2012-05-16 09:55:56 +0000159 pr_debug("%s: ip recv\n", tunnel->name);
160 print_hex_dump_bytes("", DUMP_PREFIX_OFFSET, ptr, length);
James Chapman0d767512010-04-02 06:19:00 +0000161 }
162
163 l2tp_recv_common(session, skb, ptr, optr, 0, skb->len, tunnel->recv_payload_hook);
164
165 return 0;
166
167pass_up:
168 /* Get the tunnel_id from the L2TP header */
169 if (!pskb_may_pull(skb, 12))
170 goto discard;
171
172 if ((skb->data[0] & 0xc0) != 0xc0)
173 goto discard;
174
175 tunnel_id = ntohl(*(__be32 *) &skb->data[4]);
David S. Miller9d6ddb12013-02-05 14:36:02 -0500176 tunnel = l2tp_tunnel_find(net, tunnel_id);
James Chapman0d767512010-04-02 06:19:00 +0000177 if (tunnel != NULL)
178 sk = tunnel->sock;
179 else {
180 struct iphdr *iph = (struct iphdr *) skb_network_header(skb);
181
182 read_lock_bh(&l2tp_ip_lock);
David S. Miller9d6ddb12013-02-05 14:36:02 -0500183 sk = __l2tp_ip_bind_lookup(net, iph->daddr, 0, tunnel_id);
James Chapman0d767512010-04-02 06:19:00 +0000184 read_unlock_bh(&l2tp_ip_lock);
185 }
186
187 if (sk == NULL)
188 goto discard;
189
190 sock_hold(sk);
191
192 if (!xfrm4_policy_check(sk, XFRM_POLICY_IN, skb))
193 goto discard_put;
194
195 nf_reset(skb);
196
197 return sk_receive_skb(sk, skb, 1);
198
199discard_put:
200 sock_put(sk);
201
202discard:
203 kfree_skb(skb);
204 return 0;
205}
206
207static int l2tp_ip_open(struct sock *sk)
208{
209 /* Prevent autobind. We don't have ports. */
210 inet_sk(sk)->inet_num = IPPROTO_L2TP;
211
212 write_lock_bh(&l2tp_ip_lock);
213 sk_add_node(sk, &l2tp_ip_table);
214 write_unlock_bh(&l2tp_ip_lock);
215
216 return 0;
217}
218
219static void l2tp_ip_close(struct sock *sk, long timeout)
220{
221 write_lock_bh(&l2tp_ip_lock);
222 hlist_del_init(&sk->sk_bind_node);
James Chapmand1f224a2012-04-10 00:10:42 +0000223 sk_del_node_init(sk);
James Chapman0d767512010-04-02 06:19:00 +0000224 write_unlock_bh(&l2tp_ip_lock);
225 sk_common_release(sk);
226}
227
228static void l2tp_ip_destroy_sock(struct sock *sk)
229{
230 struct sk_buff *skb;
Tom Parkin93606312013-03-19 06:11:15 +0000231 struct l2tp_tunnel *tunnel = l2tp_sock_to_tunnel(sk);
James Chapman0d767512010-04-02 06:19:00 +0000232
233 while ((skb = __skb_dequeue_tail(&sk->sk_write_queue)) != NULL)
234 kfree_skb(skb);
235
Tom Parkin93606312013-03-19 06:11:15 +0000236 if (tunnel) {
237 l2tp_tunnel_closeall(tunnel);
238 sock_put(sk);
239 }
240
James Chapman0d767512010-04-02 06:19:00 +0000241 sk_refcnt_debug_dec(sk);
242}
243
244static int l2tp_ip_bind(struct sock *sk, struct sockaddr *uaddr, int addr_len)
245{
246 struct inet_sock *inet = inet_sk(sk);
247 struct sockaddr_l2tpip *addr = (struct sockaddr_l2tpip *) uaddr;
David S. Miller9d6ddb12013-02-05 14:36:02 -0500248 struct net *net = sock_net(sk);
James Chapmanc51ce492012-05-29 03:30:42 +0000249 int ret;
James Chapman0d767512010-04-02 06:19:00 +0000250 int chk_addr_ret;
251
James Chapmanc51ce492012-05-29 03:30:42 +0000252 if (!sock_flag(sk, SOCK_ZAPPED))
253 return -EINVAL;
254 if (addr_len < sizeof(struct sockaddr_l2tpip))
255 return -EINVAL;
256 if (addr->l2tp_family != AF_INET)
257 return -EINVAL;
258
James Chapman0d767512010-04-02 06:19:00 +0000259 ret = -EADDRINUSE;
260 read_lock_bh(&l2tp_ip_lock);
David S. Miller9d6ddb12013-02-05 14:36:02 -0500261 if (__l2tp_ip_bind_lookup(net, addr->l2tp_addr.s_addr,
262 sk->sk_bound_dev_if, addr->l2tp_conn_id))
James Chapman0d767512010-04-02 06:19:00 +0000263 goto out_in_use;
264
265 read_unlock_bh(&l2tp_ip_lock);
266
267 lock_sock(sk);
268 if (sk->sk_state != TCP_CLOSE || addr_len < sizeof(struct sockaddr_l2tpip))
269 goto out;
270
David S. Miller9d6ddb12013-02-05 14:36:02 -0500271 chk_addr_ret = inet_addr_type(net, addr->l2tp_addr.s_addr);
James Chapman0d767512010-04-02 06:19:00 +0000272 ret = -EADDRNOTAVAIL;
273 if (addr->l2tp_addr.s_addr && chk_addr_ret != RTN_LOCAL &&
274 chk_addr_ret != RTN_MULTICAST && chk_addr_ret != RTN_BROADCAST)
275 goto out;
276
James Chapmanc9be48d2012-04-10 00:10:43 +0000277 if (addr->l2tp_addr.s_addr)
278 inet->inet_rcv_saddr = inet->inet_saddr = addr->l2tp_addr.s_addr;
James Chapman0d767512010-04-02 06:19:00 +0000279 if (chk_addr_ret == RTN_MULTICAST || chk_addr_ret == RTN_BROADCAST)
280 inet->inet_saddr = 0; /* Use device */
281 sk_dst_reset(sk);
282
283 l2tp_ip_sk(sk)->conn_id = addr->l2tp_conn_id;
284
285 write_lock_bh(&l2tp_ip_lock);
286 sk_add_bind_node(sk, &l2tp_ip_bind_table);
287 sk_del_node_init(sk);
288 write_unlock_bh(&l2tp_ip_lock);
289 ret = 0;
James Chapmanc51ce492012-05-29 03:30:42 +0000290 sock_reset_flag(sk, SOCK_ZAPPED);
291
James Chapman0d767512010-04-02 06:19:00 +0000292out:
293 release_sock(sk);
294
295 return ret;
296
297out_in_use:
298 read_unlock_bh(&l2tp_ip_lock);
299
300 return ret;
301}
302
303static int l2tp_ip_connect(struct sock *sk, struct sockaddr *uaddr, int addr_len)
304{
James Chapman0d767512010-04-02 06:19:00 +0000305 struct sockaddr_l2tpip *lsa = (struct sockaddr_l2tpip *) uaddr;
James Chapmande3c7a12012-04-29 21:48:47 +0000306 int rc;
James Chapman0d767512010-04-02 06:19:00 +0000307
James Chapmanc51ce492012-05-29 03:30:42 +0000308 if (sock_flag(sk, SOCK_ZAPPED)) /* Must bind first - autobinding does not work */
309 return -EINVAL;
310
James Chapman0d767512010-04-02 06:19:00 +0000311 if (addr_len < sizeof(*lsa))
James Chapmande3c7a12012-04-29 21:48:47 +0000312 return -EINVAL;
James Chapman0d767512010-04-02 06:19:00 +0000313
James Chapmande3c7a12012-04-29 21:48:47 +0000314 if (ipv4_is_multicast(lsa->l2tp_addr.s_addr))
315 return -EINVAL;
316
317 rc = ip4_datagram_connect(sk, uaddr, addr_len);
318 if (rc < 0)
319 return rc;
James Chapman0d767512010-04-02 06:19:00 +0000320
David S. Miller2f162702011-05-08 13:39:01 -0700321 lock_sock(sk);
322
James Chapman0d767512010-04-02 06:19:00 +0000323 l2tp_ip_sk(sk)->peer_conn_id = lsa->l2tp_conn_id;
324
James Chapman0d767512010-04-02 06:19:00 +0000325 write_lock_bh(&l2tp_ip_lock);
326 hlist_del_init(&sk->sk_bind_node);
327 sk_add_bind_node(sk, &l2tp_ip_bind_table);
328 write_unlock_bh(&l2tp_ip_lock);
329
David S. Miller2f162702011-05-08 13:39:01 -0700330 release_sock(sk);
James Chapman0d767512010-04-02 06:19:00 +0000331 return rc;
332}
333
James Chapmanc51ce492012-05-29 03:30:42 +0000334static int l2tp_ip_disconnect(struct sock *sk, int flags)
335{
336 if (sock_flag(sk, SOCK_ZAPPED))
337 return 0;
338
339 return udp_disconnect(sk, flags);
340}
341
James Chapman0d767512010-04-02 06:19:00 +0000342static int l2tp_ip_getname(struct socket *sock, struct sockaddr *uaddr,
343 int *uaddr_len, int peer)
344{
345 struct sock *sk = sock->sk;
346 struct inet_sock *inet = inet_sk(sk);
347 struct l2tp_ip_sock *lsk = l2tp_ip_sk(sk);
348 struct sockaddr_l2tpip *lsa = (struct sockaddr_l2tpip *)uaddr;
349
350 memset(lsa, 0, sizeof(*lsa));
351 lsa->l2tp_family = AF_INET;
352 if (peer) {
353 if (!inet->inet_dport)
354 return -ENOTCONN;
355 lsa->l2tp_conn_id = lsk->peer_conn_id;
356 lsa->l2tp_addr.s_addr = inet->inet_daddr;
357 } else {
358 __be32 addr = inet->inet_rcv_saddr;
359 if (!addr)
360 addr = inet->inet_saddr;
361 lsa->l2tp_conn_id = lsk->conn_id;
362 lsa->l2tp_addr.s_addr = addr;
363 }
364 *uaddr_len = sizeof(*lsa);
365 return 0;
366}
367
368static int l2tp_ip_backlog_recv(struct sock *sk, struct sk_buff *skb)
369{
370 int rc;
371
James Chapman0d767512010-04-02 06:19:00 +0000372 /* Charge it to the socket, dropping if the queue is full. */
373 rc = sock_queue_rcv_skb(sk, skb);
374 if (rc < 0)
375 goto drop;
376
377 return 0;
378
379drop:
David S. Miller9d6ddb12013-02-05 14:36:02 -0500380 IP_INC_STATS(sock_net(sk), IPSTATS_MIB_INDISCARDS);
James Chapman0d767512010-04-02 06:19:00 +0000381 kfree_skb(skb);
382 return -1;
383}
384
385/* Userspace will call sendmsg() on the tunnel socket to send L2TP
386 * control frames.
387 */
Ying Xue1b784142015-03-02 15:37:48 +0800388static int l2tp_ip_sendmsg(struct sock *sk, struct msghdr *msg, size_t len)
James Chapman0d767512010-04-02 06:19:00 +0000389{
390 struct sk_buff *skb;
391 int rc;
James Chapman0d767512010-04-02 06:19:00 +0000392 struct inet_sock *inet = inet_sk(sk);
James Chapman0d767512010-04-02 06:19:00 +0000393 struct rtable *rt = NULL;
David S. Millerfdbb0f02011-05-08 13:48:37 -0700394 struct flowi4 *fl4;
James Chapman0d767512010-04-02 06:19:00 +0000395 int connected = 0;
396 __be32 daddr;
397
David S. Miller2f162702011-05-08 13:39:01 -0700398 lock_sock(sk);
399
400 rc = -ENOTCONN;
James Chapman0d767512010-04-02 06:19:00 +0000401 if (sock_flag(sk, SOCK_DEAD))
David S. Miller2f162702011-05-08 13:39:01 -0700402 goto out;
James Chapman0d767512010-04-02 06:19:00 +0000403
404 /* Get and verify the address. */
405 if (msg->msg_name) {
Steffen Hurrle342dfc32014-01-17 22:53:15 +0100406 DECLARE_SOCKADDR(struct sockaddr_l2tpip *, lip, msg->msg_name);
David S. Miller2f162702011-05-08 13:39:01 -0700407 rc = -EINVAL;
James Chapman0d767512010-04-02 06:19:00 +0000408 if (msg->msg_namelen < sizeof(*lip))
David S. Miller2f162702011-05-08 13:39:01 -0700409 goto out;
James Chapman0d767512010-04-02 06:19:00 +0000410
411 if (lip->l2tp_family != AF_INET) {
David S. Miller2f162702011-05-08 13:39:01 -0700412 rc = -EAFNOSUPPORT;
James Chapman0d767512010-04-02 06:19:00 +0000413 if (lip->l2tp_family != AF_UNSPEC)
David S. Miller2f162702011-05-08 13:39:01 -0700414 goto out;
James Chapman0d767512010-04-02 06:19:00 +0000415 }
416
417 daddr = lip->l2tp_addr.s_addr;
418 } else {
Sasha Levin84768ed2012-05-02 03:58:43 +0000419 rc = -EDESTADDRREQ;
James Chapman0d767512010-04-02 06:19:00 +0000420 if (sk->sk_state != TCP_ESTABLISHED)
Sasha Levin84768ed2012-05-02 03:58:43 +0000421 goto out;
James Chapman0d767512010-04-02 06:19:00 +0000422
423 daddr = inet->inet_daddr;
424 connected = 1;
425 }
426
427 /* Allocate a socket buffer */
428 rc = -ENOMEM;
429 skb = sock_wmalloc(sk, 2 + NET_SKB_PAD + sizeof(struct iphdr) +
430 4 + len, 0, GFP_KERNEL);
431 if (!skb)
432 goto error;
433
434 /* Reserve space for headers, putting IP header on 4-byte boundary. */
435 skb_reserve(skb, 2 + NET_SKB_PAD);
436 skb_reset_network_header(skb);
437 skb_reserve(skb, sizeof(struct iphdr));
438 skb_reset_transport_header(skb);
439
440 /* Insert 0 session_id */
441 *((__be32 *) skb_put(skb, 4)) = 0;
442
443 /* Copy user data into skb */
Al Viro6ce8e9c2014-04-06 21:25:44 -0400444 rc = memcpy_from_msg(skb_put(skb, len), msg, len);
James Chapman0d767512010-04-02 06:19:00 +0000445 if (rc < 0) {
446 kfree_skb(skb);
447 goto error;
448 }
449
David S. Millerfdbb0f02011-05-08 13:48:37 -0700450 fl4 = &inet->cork.fl.u.ip4;
James Chapman0d767512010-04-02 06:19:00 +0000451 if (connected)
452 rt = (struct rtable *) __sk_dst_check(sk, 0);
453
Eric Dumazet081b1b12011-06-11 22:27:09 +0000454 rcu_read_lock();
James Chapman0d767512010-04-02 06:19:00 +0000455 if (rt == NULL) {
Eric Dumazet081b1b12011-06-11 22:27:09 +0000456 const struct ip_options_rcu *inet_opt;
Eric Dumazetf6d8bd02011-04-21 09:45:37 +0000457
David S. Miller778865a2011-04-28 13:54:06 -0700458 inet_opt = rcu_dereference(inet->inet_opt);
Eric Dumazetf6d8bd02011-04-21 09:45:37 +0000459
James Chapman0d767512010-04-02 06:19:00 +0000460 /* Use correct destination address if we have options. */
Eric Dumazetf6d8bd02011-04-21 09:45:37 +0000461 if (inet_opt && inet_opt->opt.srr)
462 daddr = inet_opt->opt.faddr;
James Chapman0d767512010-04-02 06:19:00 +0000463
David S. Miller78fbfd82011-03-12 00:00:52 -0500464 /* If this fails, retransmit mechanism of transport layer will
465 * keep trying until route appears or the connection times
466 * itself out.
467 */
David S. Millerfdbb0f02011-05-08 13:48:37 -0700468 rt = ip_route_output_ports(sock_net(sk), fl4, sk,
David S. Miller78fbfd82011-03-12 00:00:52 -0500469 daddr, inet->inet_saddr,
470 inet->inet_dport, inet->inet_sport,
471 sk->sk_protocol, RT_CONN_FLAGS(sk),
472 sk->sk_bound_dev_if);
473 if (IS_ERR(rt))
474 goto no_route;
Eric Dumazet4399a4d2012-06-08 06:25:00 +0000475 if (connected) {
Eric Dumazet081b1b12011-06-11 22:27:09 +0000476 sk_setup_caps(sk, &rt->dst);
Eric Dumazet4399a4d2012-06-08 06:25:00 +0000477 } else {
478 skb_dst_set(skb, &rt->dst);
479 goto xmit;
480 }
James Chapman0d767512010-04-02 06:19:00 +0000481 }
Eric Dumazet081b1b12011-06-11 22:27:09 +0000482
483 /* We dont need to clone dst here, it is guaranteed to not disappear.
484 * __dev_xmit_skb() might force a refcount if needed.
485 */
486 skb_dst_set_noref(skb, &rt->dst);
James Chapman0d767512010-04-02 06:19:00 +0000487
Eric Dumazet4399a4d2012-06-08 06:25:00 +0000488xmit:
James Chapman0d767512010-04-02 06:19:00 +0000489 /* Queue the packet to IP for output */
Eric Dumazetb0270e92014-04-15 12:58:34 -0400490 rc = ip_queue_xmit(sk, skb, &inet->cork.fl);
Eric Dumazet081b1b12011-06-11 22:27:09 +0000491 rcu_read_unlock();
James Chapman0d767512010-04-02 06:19:00 +0000492
493error:
James Chapmanc8657fd2012-04-29 21:48:48 +0000494 if (rc >= 0)
James Chapman0d767512010-04-02 06:19:00 +0000495 rc = len;
James Chapman0d767512010-04-02 06:19:00 +0000496
David S. Miller2f162702011-05-08 13:39:01 -0700497out:
498 release_sock(sk);
James Chapman0d767512010-04-02 06:19:00 +0000499 return rc;
500
501no_route:
Eric Dumazet081b1b12011-06-11 22:27:09 +0000502 rcu_read_unlock();
James Chapman0d767512010-04-02 06:19:00 +0000503 IP_INC_STATS(sock_net(sk), IPSTATS_MIB_OUTNOROUTES);
504 kfree_skb(skb);
David S. Miller2f162702011-05-08 13:39:01 -0700505 rc = -EHOSTUNREACH;
506 goto out;
James Chapman0d767512010-04-02 06:19:00 +0000507}
508
Ying Xue1b784142015-03-02 15:37:48 +0800509static int l2tp_ip_recvmsg(struct sock *sk, struct msghdr *msg,
James Chapman0d767512010-04-02 06:19:00 +0000510 size_t len, int noblock, int flags, int *addr_len)
511{
512 struct inet_sock *inet = inet_sk(sk);
James Chapman0d767512010-04-02 06:19:00 +0000513 size_t copied = 0;
514 int err = -EOPNOTSUPP;
Steffen Hurrle342dfc32014-01-17 22:53:15 +0100515 DECLARE_SOCKADDR(struct sockaddr_in *, sin, msg->msg_name);
James Chapman0d767512010-04-02 06:19:00 +0000516 struct sk_buff *skb;
517
518 if (flags & MSG_OOB)
519 goto out;
520
James Chapman0d767512010-04-02 06:19:00 +0000521 skb = skb_recv_datagram(sk, flags, noblock, &err);
522 if (!skb)
523 goto out;
524
525 copied = skb->len;
526 if (len < copied) {
527 msg->msg_flags |= MSG_TRUNC;
528 copied = len;
529 }
530
David S. Miller51f3d022014-11-05 16:46:40 -0500531 err = skb_copy_datagram_msg(skb, 0, msg, copied);
James Chapman0d767512010-04-02 06:19:00 +0000532 if (err)
533 goto done;
534
535 sock_recv_timestamp(msg, sk, skb);
536
537 /* Copy the address. */
538 if (sin) {
539 sin->sin_family = AF_INET;
540 sin->sin_addr.s_addr = ip_hdr(skb)->saddr;
541 sin->sin_port = 0;
542 memset(&sin->sin_zero, 0, sizeof(sin->sin_zero));
Hannes Frederic Sowabceaa902013-11-18 04:20:45 +0100543 *addr_len = sizeof(*sin);
James Chapman0d767512010-04-02 06:19:00 +0000544 }
545 if (inet->cmsg_flags)
546 ip_cmsg_recv(msg, skb);
547 if (flags & MSG_TRUNC)
548 copied = skb->len;
549done:
550 skb_free_datagram(sk, skb);
551out:
James Chapmanc8657fd2012-04-29 21:48:48 +0000552 return err ? err : copied;
James Chapman0d767512010-04-02 06:19:00 +0000553}
554
stephen hemmingerfc130842010-10-21 07:50:46 +0000555static struct proto l2tp_ip_prot = {
James Chapman0d767512010-04-02 06:19:00 +0000556 .name = "L2TP/IP",
557 .owner = THIS_MODULE,
558 .init = l2tp_ip_open,
559 .close = l2tp_ip_close,
560 .bind = l2tp_ip_bind,
561 .connect = l2tp_ip_connect,
James Chapmanc51ce492012-05-29 03:30:42 +0000562 .disconnect = l2tp_ip_disconnect,
James Chapman0d767512010-04-02 06:19:00 +0000563 .ioctl = udp_ioctl,
564 .destroy = l2tp_ip_destroy_sock,
565 .setsockopt = ip_setsockopt,
566 .getsockopt = ip_getsockopt,
567 .sendmsg = l2tp_ip_sendmsg,
568 .recvmsg = l2tp_ip_recvmsg,
569 .backlog_rcv = l2tp_ip_backlog_recv,
570 .hash = inet_hash,
571 .unhash = inet_unhash,
572 .obj_size = sizeof(struct l2tp_ip_sock),
573#ifdef CONFIG_COMPAT
574 .compat_setsockopt = compat_ip_setsockopt,
575 .compat_getsockopt = compat_ip_getsockopt,
576#endif
577};
578
579static const struct proto_ops l2tp_ip_ops = {
580 .family = PF_INET,
581 .owner = THIS_MODULE,
582 .release = inet_release,
583 .bind = inet_bind,
584 .connect = inet_dgram_connect,
585 .socketpair = sock_no_socketpair,
586 .accept = sock_no_accept,
587 .getname = l2tp_ip_getname,
588 .poll = datagram_poll,
589 .ioctl = inet_ioctl,
590 .listen = sock_no_listen,
591 .shutdown = inet_shutdown,
592 .setsockopt = sock_common_setsockopt,
593 .getsockopt = sock_common_getsockopt,
594 .sendmsg = inet_sendmsg,
595 .recvmsg = sock_common_recvmsg,
596 .mmap = sock_no_mmap,
597 .sendpage = sock_no_sendpage,
598#ifdef CONFIG_COMPAT
599 .compat_setsockopt = compat_sock_common_setsockopt,
600 .compat_getsockopt = compat_sock_common_getsockopt,
601#endif
602};
603
604static struct inet_protosw l2tp_ip_protosw = {
605 .type = SOCK_DGRAM,
606 .protocol = IPPROTO_L2TP,
607 .prot = &l2tp_ip_prot,
608 .ops = &l2tp_ip_ops,
James Chapman0d767512010-04-02 06:19:00 +0000609};
610
611static struct net_protocol l2tp_ip_protocol __read_mostly = {
612 .handler = l2tp_ip_recv,
David S. Miller9d6ddb12013-02-05 14:36:02 -0500613 .netns_ok = 1,
James Chapman0d767512010-04-02 06:19:00 +0000614};
615
616static int __init l2tp_ip_init(void)
617{
618 int err;
619
Joe Perchesa4ca44f2012-05-16 09:55:56 +0000620 pr_info("L2TP IP encapsulation support (L2TPv3)\n");
James Chapman0d767512010-04-02 06:19:00 +0000621
622 err = proto_register(&l2tp_ip_prot, 1);
623 if (err != 0)
624 goto out;
625
626 err = inet_add_protocol(&l2tp_ip_protocol, IPPROTO_L2TP);
627 if (err)
628 goto out1;
629
630 inet_register_protosw(&l2tp_ip_protosw);
631 return 0;
632
633out1:
634 proto_unregister(&l2tp_ip_prot);
635out:
636 return err;
637}
638
639static void __exit l2tp_ip_exit(void)
640{
641 inet_unregister_protosw(&l2tp_ip_protosw);
642 inet_del_protocol(&l2tp_ip_protocol, IPPROTO_L2TP);
643 proto_unregister(&l2tp_ip_prot);
644}
645
646module_init(l2tp_ip_init);
647module_exit(l2tp_ip_exit);
648
649MODULE_LICENSE("GPL");
650MODULE_AUTHOR("James Chapman <jchapman@katalix.com>");
651MODULE_DESCRIPTION("L2TP over IP");
652MODULE_VERSION("1.0");
Michal Mareke8d34a882010-12-06 02:39:12 +0000653
Lucas De Marchie9c54992011-04-26 23:28:26 -0700654/* Use the value of SOCK_DGRAM (2) directory, because __stringify doesn't like
Michal Mareke8d34a882010-12-06 02:39:12 +0000655 * enums
656 */
657MODULE_ALIAS_NET_PF_PROTO_TYPE(PF_INET, 2, IPPROTO_L2TP);