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Commit | Line | Data |
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2874c5fd | 1 | // SPDX-License-Identifier: GPL-2.0-or-later |
0d76751f JC |
2 | /* |
3 | * L2TPv3 IP encapsulation support | |
4 | * | |
5 | * Copyright (c) 2008,2009,2010 Katalix Systems Ltd | |
0d76751f JC |
6 | */ |
7 | ||
a4ca44fa JP |
8 | #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt |
9 | ||
72fb96e7 | 10 | #include <asm/ioctls.h> |
0d76751f JC |
11 | #include <linux/icmp.h> |
12 | #include <linux/module.h> | |
13 | #include <linux/skbuff.h> | |
14 | #include <linux/random.h> | |
15 | #include <linux/socket.h> | |
16 | #include <linux/l2tp.h> | |
17 | #include <linux/in.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> | |
24 | #include <net/tcp_states.h> | |
25 | #include <net/protocol.h> | |
26 | #include <net/xfrm.h> | |
27 | ||
28 | #include "l2tp_core.h" | |
29 | ||
30 | struct l2tp_ip_sock { | |
31 | /* inet_sock has to be the first member of l2tp_ip_sock */ | |
32 | struct inet_sock inet; | |
33 | ||
c8657fd5 JC |
34 | u32 conn_id; |
35 | u32 peer_conn_id; | |
0d76751f JC |
36 | }; |
37 | ||
38 | static DEFINE_RWLOCK(l2tp_ip_lock); | |
39 | static struct hlist_head l2tp_ip_table; | |
40 | static struct hlist_head l2tp_ip_bind_table; | |
41 | ||
42 | static inline struct l2tp_ip_sock *l2tp_ip_sk(const struct sock *sk) | |
43 | { | |
44 | return (struct l2tp_ip_sock *)sk; | |
45 | } | |
46 | ||
a9b2dff8 GN |
47 | static struct sock *__l2tp_ip_bind_lookup(const struct net *net, __be32 laddr, |
48 | __be32 raddr, int dif, u32 tunnel_id) | |
0d76751f | 49 | { |
0d76751f JC |
50 | struct sock *sk; |
51 | ||
b67bfe0d | 52 | sk_for_each_bound(sk, &l2tp_ip_bind_table) { |
bb39b0bd GN |
53 | const struct l2tp_ip_sock *l2tp = l2tp_ip_sk(sk); |
54 | const struct inet_sock *inet = inet_sk(sk); | |
0d76751f | 55 | |
c5fdae04 GN |
56 | if (!net_eq(sock_net(sk), net)) |
57 | continue; | |
58 | ||
59 | if (sk->sk_bound_dev_if && dif && sk->sk_bound_dev_if != dif) | |
60 | continue; | |
61 | ||
62 | if (inet->inet_rcv_saddr && laddr && | |
63 | inet->inet_rcv_saddr != laddr) | |
64 | continue; | |
65 | ||
66 | if (inet->inet_daddr && raddr && inet->inet_daddr != raddr) | |
67 | continue; | |
68 | ||
69 | if (l2tp->conn_id != tunnel_id) | |
70 | continue; | |
71 | ||
72 | goto found; | |
0d76751f JC |
73 | } |
74 | ||
75 | sk = NULL; | |
76 | found: | |
77 | return sk; | |
78 | } | |
79 | ||
0d76751f JC |
80 | /* When processing receive frames, there are two cases to |
81 | * consider. Data frames consist of a non-zero session-id and an | |
82 | * optional cookie. Control frames consist of a regular L2TP header | |
83 | * preceded by 32-bits of zeros. | |
84 | * | |
85 | * L2TPv3 Session Header Over IP | |
86 | * | |
87 | * 0 1 2 3 | |
88 | * 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 | |
89 | * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | |
90 | * | Session ID | | |
91 | * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | |
92 | * | Cookie (optional, maximum 64 bits)... | |
93 | * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | |
94 | * | | |
95 | * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | |
96 | * | |
97 | * L2TPv3 Control Message Header Over IP | |
98 | * | |
99 | * 0 1 2 3 | |
100 | * 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 | |
101 | * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | |
102 | * | (32 bits of zeros) | | |
103 | * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | |
104 | * |T|L|x|x|S|x|x|x|x|x|x|x| Ver | Length | | |
105 | * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | |
106 | * | Control Connection ID | | |
107 | * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | |
108 | * | Ns | Nr | | |
109 | * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | |
110 | * | |
111 | * All control frames are passed to userspace. | |
112 | */ | |
113 | static int l2tp_ip_recv(struct sk_buff *skb) | |
114 | { | |
9d6ddb19 | 115 | struct net *net = dev_net(skb->dev); |
0d76751f JC |
116 | struct sock *sk; |
117 | u32 session_id; | |
118 | u32 tunnel_id; | |
119 | unsigned char *ptr, *optr; | |
120 | struct l2tp_session *session; | |
121 | struct l2tp_tunnel *tunnel = NULL; | |
8f7dc9ae | 122 | struct iphdr *iph; |
0d76751f | 123 | int length; |
0d76751f | 124 | |
0d76751f JC |
125 | if (!pskb_may_pull(skb, 4)) |
126 | goto discard; | |
127 | ||
5745b823 HY |
128 | /* Point to L2TP header */ |
129 | optr = ptr = skb->data; | |
0d76751f JC |
130 | session_id = ntohl(*((__be32 *) ptr)); |
131 | ptr += 4; | |
132 | ||
133 | /* RFC3931: L2TP/IP packets have the first 4 bytes containing | |
134 | * the session_id. If it is 0, the packet is a L2TP control | |
135 | * frame and the session_id value can be discarded. | |
136 | */ | |
137 | if (session_id == 0) { | |
138 | __skb_pull(skb, 4); | |
139 | goto pass_up; | |
140 | } | |
141 | ||
142 | /* Ok, this is a data packet. Lookup the session. */ | |
01e28b92 | 143 | session = l2tp_session_get(net, session_id); |
61b9a047 | 144 | if (!session) |
0d76751f JC |
145 | goto discard; |
146 | ||
147 | tunnel = session->tunnel; | |
61b9a047 GN |
148 | if (!tunnel) |
149 | goto discard_sess; | |
0d76751f JC |
150 | |
151 | /* Trace packet contents, if enabled */ | |
152 | if (tunnel->debug & L2TP_MSG_DATA) { | |
153 | length = min(32u, skb->len); | |
154 | if (!pskb_may_pull(skb, length)) | |
61b9a047 | 155 | goto discard_sess; |
0d76751f | 156 | |
5745b823 HY |
157 | /* Point to L2TP header */ |
158 | optr = ptr = skb->data; | |
159 | ptr += 4; | |
a4ca44fa JP |
160 | pr_debug("%s: ip recv\n", tunnel->name); |
161 | print_hex_dump_bytes("", DUMP_PREFIX_OFFSET, ptr, length); | |
0d76751f JC |
162 | } |
163 | ||
4522a70d JW |
164 | if (l2tp_v3_ensure_opt_in_linear(session, skb, &ptr, &optr)) |
165 | goto discard_sess; | |
166 | ||
2b139e6b | 167 | l2tp_recv_common(session, skb, ptr, optr, 0, skb->len); |
61b9a047 | 168 | l2tp_session_dec_refcount(session); |
0d76751f JC |
169 | |
170 | return 0; | |
171 | ||
172 | pass_up: | |
173 | /* Get the tunnel_id from the L2TP header */ | |
174 | if (!pskb_may_pull(skb, 12)) | |
175 | goto discard; | |
176 | ||
177 | if ((skb->data[0] & 0xc0) != 0xc0) | |
178 | goto discard; | |
179 | ||
180 | tunnel_id = ntohl(*(__be32 *) &skb->data[4]); | |
8f7dc9ae GN |
181 | iph = (struct iphdr *)skb_network_header(skb); |
182 | ||
183 | read_lock_bh(&l2tp_ip_lock); | |
184 | sk = __l2tp_ip_bind_lookup(net, iph->daddr, iph->saddr, inet_iif(skb), | |
185 | tunnel_id); | |
186 | if (!sk) { | |
0d76751f | 187 | read_unlock_bh(&l2tp_ip_lock); |
8f7dc9ae | 188 | goto discard; |
0d76751f | 189 | } |
8f7dc9ae GN |
190 | sock_hold(sk); |
191 | read_unlock_bh(&l2tp_ip_lock); | |
0d76751f | 192 | |
0d76751f JC |
193 | if (!xfrm4_policy_check(sk, XFRM_POLICY_IN, skb)) |
194 | goto discard_put; | |
195 | ||
196 | nf_reset(skb); | |
197 | ||
198 | return sk_receive_skb(sk, skb, 1); | |
199 | ||
61b9a047 | 200 | discard_sess: |
61b9a047 GN |
201 | l2tp_session_dec_refcount(session); |
202 | goto discard; | |
203 | ||
0d76751f JC |
204 | discard_put: |
205 | sock_put(sk); | |
206 | ||
207 | discard: | |
208 | kfree_skb(skb); | |
209 | return 0; | |
210 | } | |
211 | ||
212 | static int l2tp_ip_open(struct sock *sk) | |
213 | { | |
214 | /* Prevent autobind. We don't have ports. */ | |
215 | inet_sk(sk)->inet_num = IPPROTO_L2TP; | |
216 | ||
217 | write_lock_bh(&l2tp_ip_lock); | |
218 | sk_add_node(sk, &l2tp_ip_table); | |
219 | write_unlock_bh(&l2tp_ip_lock); | |
220 | ||
221 | return 0; | |
222 | } | |
223 | ||
224 | static void l2tp_ip_close(struct sock *sk, long timeout) | |
225 | { | |
226 | write_lock_bh(&l2tp_ip_lock); | |
227 | hlist_del_init(&sk->sk_bind_node); | |
d1f224ae | 228 | sk_del_node_init(sk); |
0d76751f JC |
229 | write_unlock_bh(&l2tp_ip_lock); |
230 | sk_common_release(sk); | |
231 | } | |
232 | ||
233 | static void l2tp_ip_destroy_sock(struct sock *sk) | |
234 | { | |
235 | struct sk_buff *skb; | |
d00fa9ad | 236 | struct l2tp_tunnel *tunnel = sk->sk_user_data; |
0d76751f JC |
237 | |
238 | while ((skb = __skb_dequeue_tail(&sk->sk_write_queue)) != NULL) | |
239 | kfree_skb(skb); | |
240 | ||
d00fa9ad JC |
241 | if (tunnel) |
242 | l2tp_tunnel_delete(tunnel); | |
0d76751f JC |
243 | } |
244 | ||
245 | static int l2tp_ip_bind(struct sock *sk, struct sockaddr *uaddr, int addr_len) | |
246 | { | |
247 | struct inet_sock *inet = inet_sk(sk); | |
248 | struct sockaddr_l2tpip *addr = (struct sockaddr_l2tpip *) uaddr; | |
9d6ddb19 | 249 | struct net *net = sock_net(sk); |
c51ce497 | 250 | int ret; |
0d76751f JC |
251 | int chk_addr_ret; |
252 | ||
c51ce497 JC |
253 | if (addr_len < sizeof(struct sockaddr_l2tpip)) |
254 | return -EINVAL; | |
255 | if (addr->l2tp_family != AF_INET) | |
256 | return -EINVAL; | |
257 | ||
0d76751f | 258 | lock_sock(sk); |
d5e3a190 GN |
259 | |
260 | ret = -EINVAL; | |
32c23116 GN |
261 | if (!sock_flag(sk, SOCK_ZAPPED)) |
262 | goto out; | |
263 | ||
8cf2f704 | 264 | if (sk->sk_state != TCP_CLOSE) |
0d76751f JC |
265 | goto out; |
266 | ||
9d6ddb19 | 267 | chk_addr_ret = inet_addr_type(net, addr->l2tp_addr.s_addr); |
0d76751f JC |
268 | ret = -EADDRNOTAVAIL; |
269 | if (addr->l2tp_addr.s_addr && chk_addr_ret != RTN_LOCAL && | |
270 | chk_addr_ret != RTN_MULTICAST && chk_addr_ret != RTN_BROADCAST) | |
271 | goto out; | |
272 | ||
c9be48dc JC |
273 | if (addr->l2tp_addr.s_addr) |
274 | inet->inet_rcv_saddr = inet->inet_saddr = addr->l2tp_addr.s_addr; | |
0d76751f JC |
275 | if (chk_addr_ret == RTN_MULTICAST || chk_addr_ret == RTN_BROADCAST) |
276 | inet->inet_saddr = 0; /* Use device */ | |
0d76751f | 277 | |
d5e3a190 | 278 | write_lock_bh(&l2tp_ip_lock); |
a9b2dff8 | 279 | if (__l2tp_ip_bind_lookup(net, addr->l2tp_addr.s_addr, 0, |
d5e3a190 GN |
280 | sk->sk_bound_dev_if, addr->l2tp_conn_id)) { |
281 | write_unlock_bh(&l2tp_ip_lock); | |
282 | ret = -EADDRINUSE; | |
283 | goto out; | |
284 | } | |
285 | ||
286 | sk_dst_reset(sk); | |
0d76751f JC |
287 | l2tp_ip_sk(sk)->conn_id = addr->l2tp_conn_id; |
288 | ||
0d76751f JC |
289 | sk_add_bind_node(sk, &l2tp_ip_bind_table); |
290 | sk_del_node_init(sk); | |
291 | write_unlock_bh(&l2tp_ip_lock); | |
d5e3a190 | 292 | |
0d76751f | 293 | ret = 0; |
c51ce497 JC |
294 | sock_reset_flag(sk, SOCK_ZAPPED); |
295 | ||
0d76751f JC |
296 | out: |
297 | release_sock(sk); | |
298 | ||
0d76751f JC |
299 | return ret; |
300 | } | |
301 | ||
302 | static int l2tp_ip_connect(struct sock *sk, struct sockaddr *uaddr, int addr_len) | |
303 | { | |
0d76751f | 304 | struct sockaddr_l2tpip *lsa = (struct sockaddr_l2tpip *) uaddr; |
de3c7a18 | 305 | int rc; |
0d76751f | 306 | |
0d76751f | 307 | if (addr_len < sizeof(*lsa)) |
de3c7a18 | 308 | return -EINVAL; |
2f16270f | 309 | |
0d76751f | 310 | if (ipv4_is_multicast(lsa->l2tp_addr.s_addr)) |
de3c7a18 | 311 | return -EINVAL; |
0d76751f | 312 | |
de3c7a18 | 313 | lock_sock(sk); |
0d76751f | 314 | |
0382a25a GN |
315 | /* Must bind first - autobinding does not work */ |
316 | if (sock_flag(sk, SOCK_ZAPPED)) { | |
317 | rc = -EINVAL; | |
318 | goto out_sk; | |
319 | } | |
320 | ||
321 | rc = __ip4_datagram_connect(sk, uaddr, addr_len); | |
322 | if (rc < 0) | |
323 | goto out_sk; | |
324 | ||
0d76751f JC |
325 | l2tp_ip_sk(sk)->peer_conn_id = lsa->l2tp_conn_id; |
326 | ||
0d76751f JC |
327 | write_lock_bh(&l2tp_ip_lock); |
328 | hlist_del_init(&sk->sk_bind_node); | |
329 | sk_add_bind_node(sk, &l2tp_ip_bind_table); | |
330 | write_unlock_bh(&l2tp_ip_lock); | |
331 | ||
0382a25a | 332 | out_sk: |
2f16270f | 333 | release_sock(sk); |
0382a25a | 334 | |
0d76751f JC |
335 | return rc; |
336 | } | |
337 | ||
c51ce497 JC |
338 | static int l2tp_ip_disconnect(struct sock *sk, int flags) |
339 | { | |
340 | if (sock_flag(sk, SOCK_ZAPPED)) | |
341 | return 0; | |
342 | ||
286c72de | 343 | return __udp_disconnect(sk, flags); |
c51ce497 JC |
344 | } |
345 | ||
0d76751f | 346 | static int l2tp_ip_getname(struct socket *sock, struct sockaddr *uaddr, |
9b2c45d4 | 347 | int peer) |
0d76751f JC |
348 | { |
349 | struct sock *sk = sock->sk; | |
350 | struct inet_sock *inet = inet_sk(sk); | |
351 | struct l2tp_ip_sock *lsk = l2tp_ip_sk(sk); | |
352 | struct sockaddr_l2tpip *lsa = (struct sockaddr_l2tpip *)uaddr; | |
353 | ||
354 | memset(lsa, 0, sizeof(*lsa)); | |
355 | lsa->l2tp_family = AF_INET; | |
356 | if (peer) { | |
357 | if (!inet->inet_dport) | |
358 | return -ENOTCONN; | |
359 | lsa->l2tp_conn_id = lsk->peer_conn_id; | |
360 | lsa->l2tp_addr.s_addr = inet->inet_daddr; | |
361 | } else { | |
362 | __be32 addr = inet->inet_rcv_saddr; | |
363 | if (!addr) | |
364 | addr = inet->inet_saddr; | |
365 | lsa->l2tp_conn_id = lsk->conn_id; | |
366 | lsa->l2tp_addr.s_addr = addr; | |
367 | } | |
9b2c45d4 | 368 | return sizeof(*lsa); |
0d76751f JC |
369 | } |
370 | ||
371 | static int l2tp_ip_backlog_recv(struct sock *sk, struct sk_buff *skb) | |
372 | { | |
373 | int rc; | |
374 | ||
0d76751f JC |
375 | /* Charge it to the socket, dropping if the queue is full. */ |
376 | rc = sock_queue_rcv_skb(sk, skb); | |
377 | if (rc < 0) | |
378 | goto drop; | |
379 | ||
380 | return 0; | |
381 | ||
382 | drop: | |
9d6ddb19 | 383 | IP_INC_STATS(sock_net(sk), IPSTATS_MIB_INDISCARDS); |
0d76751f | 384 | kfree_skb(skb); |
51fb60eb | 385 | return 0; |
0d76751f JC |
386 | } |
387 | ||
388 | /* Userspace will call sendmsg() on the tunnel socket to send L2TP | |
389 | * control frames. | |
390 | */ | |
1b784140 | 391 | static int l2tp_ip_sendmsg(struct sock *sk, struct msghdr *msg, size_t len) |
0d76751f JC |
392 | { |
393 | struct sk_buff *skb; | |
394 | int rc; | |
0d76751f | 395 | struct inet_sock *inet = inet_sk(sk); |
0d76751f | 396 | struct rtable *rt = NULL; |
fdbb0f07 | 397 | struct flowi4 *fl4; |
0d76751f JC |
398 | int connected = 0; |
399 | __be32 daddr; | |
400 | ||
2f16270f DM |
401 | lock_sock(sk); |
402 | ||
403 | rc = -ENOTCONN; | |
0d76751f | 404 | if (sock_flag(sk, SOCK_DEAD)) |
2f16270f | 405 | goto out; |
0d76751f JC |
406 | |
407 | /* Get and verify the address. */ | |
408 | if (msg->msg_name) { | |
342dfc30 | 409 | DECLARE_SOCKADDR(struct sockaddr_l2tpip *, lip, msg->msg_name); |
2f16270f | 410 | rc = -EINVAL; |
0d76751f | 411 | if (msg->msg_namelen < sizeof(*lip)) |
2f16270f | 412 | goto out; |
0d76751f JC |
413 | |
414 | if (lip->l2tp_family != AF_INET) { | |
2f16270f | 415 | rc = -EAFNOSUPPORT; |
0d76751f | 416 | if (lip->l2tp_family != AF_UNSPEC) |
2f16270f | 417 | goto out; |
0d76751f JC |
418 | } |
419 | ||
420 | daddr = lip->l2tp_addr.s_addr; | |
421 | } else { | |
84768edb | 422 | rc = -EDESTADDRREQ; |
0d76751f | 423 | if (sk->sk_state != TCP_ESTABLISHED) |
84768edb | 424 | goto out; |
0d76751f JC |
425 | |
426 | daddr = inet->inet_daddr; | |
427 | connected = 1; | |
428 | } | |
429 | ||
430 | /* Allocate a socket buffer */ | |
431 | rc = -ENOMEM; | |
432 | skb = sock_wmalloc(sk, 2 + NET_SKB_PAD + sizeof(struct iphdr) + | |
433 | 4 + len, 0, GFP_KERNEL); | |
434 | if (!skb) | |
435 | goto error; | |
436 | ||
437 | /* Reserve space for headers, putting IP header on 4-byte boundary. */ | |
438 | skb_reserve(skb, 2 + NET_SKB_PAD); | |
439 | skb_reset_network_header(skb); | |
440 | skb_reserve(skb, sizeof(struct iphdr)); | |
441 | skb_reset_transport_header(skb); | |
442 | ||
443 | /* Insert 0 session_id */ | |
444 | *((__be32 *) skb_put(skb, 4)) = 0; | |
445 | ||
446 | /* Copy user data into skb */ | |
6ce8e9ce | 447 | rc = memcpy_from_msg(skb_put(skb, len), msg, len); |
0d76751f JC |
448 | if (rc < 0) { |
449 | kfree_skb(skb); | |
450 | goto error; | |
451 | } | |
452 | ||
fdbb0f07 | 453 | fl4 = &inet->cork.fl.u.ip4; |
0d76751f JC |
454 | if (connected) |
455 | rt = (struct rtable *) __sk_dst_check(sk, 0); | |
456 | ||
081b1b1b | 457 | rcu_read_lock(); |
0d76751f | 458 | if (rt == NULL) { |
081b1b1b | 459 | const struct ip_options_rcu *inet_opt; |
f6d8bd05 | 460 | |
778865a5 | 461 | inet_opt = rcu_dereference(inet->inet_opt); |
f6d8bd05 | 462 | |
0d76751f | 463 | /* Use correct destination address if we have options. */ |
f6d8bd05 ED |
464 | if (inet_opt && inet_opt->opt.srr) |
465 | daddr = inet_opt->opt.faddr; | |
0d76751f | 466 | |
78fbfd8a DM |
467 | /* If this fails, retransmit mechanism of transport layer will |
468 | * keep trying until route appears or the connection times | |
469 | * itself out. | |
470 | */ | |
fdbb0f07 | 471 | rt = ip_route_output_ports(sock_net(sk), fl4, sk, |
78fbfd8a DM |
472 | daddr, inet->inet_saddr, |
473 | inet->inet_dport, inet->inet_sport, | |
474 | sk->sk_protocol, RT_CONN_FLAGS(sk), | |
475 | sk->sk_bound_dev_if); | |
476 | if (IS_ERR(rt)) | |
477 | goto no_route; | |
4399a4df | 478 | if (connected) { |
081b1b1b | 479 | sk_setup_caps(sk, &rt->dst); |
4399a4df ED |
480 | } else { |
481 | skb_dst_set(skb, &rt->dst); | |
482 | goto xmit; | |
483 | } | |
0d76751f | 484 | } |
081b1b1b ED |
485 | |
486 | /* We dont need to clone dst here, it is guaranteed to not disappear. | |
487 | * __dev_xmit_skb() might force a refcount if needed. | |
488 | */ | |
489 | skb_dst_set_noref(skb, &rt->dst); | |
0d76751f | 490 | |
4399a4df | 491 | xmit: |
0d76751f | 492 | /* Queue the packet to IP for output */ |
b0270e91 | 493 | rc = ip_queue_xmit(sk, skb, &inet->cork.fl); |
081b1b1b | 494 | rcu_read_unlock(); |
0d76751f JC |
495 | |
496 | error: | |
c8657fd5 | 497 | if (rc >= 0) |
0d76751f | 498 | rc = len; |
0d76751f | 499 | |
2f16270f DM |
500 | out: |
501 | release_sock(sk); | |
0d76751f JC |
502 | return rc; |
503 | ||
504 | no_route: | |
081b1b1b | 505 | rcu_read_unlock(); |
0d76751f JC |
506 | IP_INC_STATS(sock_net(sk), IPSTATS_MIB_OUTNOROUTES); |
507 | kfree_skb(skb); | |
2f16270f DM |
508 | rc = -EHOSTUNREACH; |
509 | goto out; | |
0d76751f JC |
510 | } |
511 | ||
1b784140 | 512 | static int l2tp_ip_recvmsg(struct sock *sk, struct msghdr *msg, |
0d76751f JC |
513 | size_t len, int noblock, int flags, int *addr_len) |
514 | { | |
515 | struct inet_sock *inet = inet_sk(sk); | |
0d76751f JC |
516 | size_t copied = 0; |
517 | int err = -EOPNOTSUPP; | |
342dfc30 | 518 | DECLARE_SOCKADDR(struct sockaddr_in *, sin, msg->msg_name); |
0d76751f JC |
519 | struct sk_buff *skb; |
520 | ||
521 | if (flags & MSG_OOB) | |
522 | goto out; | |
523 | ||
0d76751f JC |
524 | skb = skb_recv_datagram(sk, flags, noblock, &err); |
525 | if (!skb) | |
526 | goto out; | |
527 | ||
528 | copied = skb->len; | |
529 | if (len < copied) { | |
530 | msg->msg_flags |= MSG_TRUNC; | |
531 | copied = len; | |
532 | } | |
533 | ||
51f3d02b | 534 | err = skb_copy_datagram_msg(skb, 0, msg, copied); |
0d76751f JC |
535 | if (err) |
536 | goto done; | |
537 | ||
538 | sock_recv_timestamp(msg, sk, skb); | |
539 | ||
540 | /* Copy the address. */ | |
541 | if (sin) { | |
542 | sin->sin_family = AF_INET; | |
543 | sin->sin_addr.s_addr = ip_hdr(skb)->saddr; | |
544 | sin->sin_port = 0; | |
545 | memset(&sin->sin_zero, 0, sizeof(sin->sin_zero)); | |
bceaa902 | 546 | *addr_len = sizeof(*sin); |
0d76751f JC |
547 | } |
548 | if (inet->cmsg_flags) | |
549 | ip_cmsg_recv(msg, skb); | |
550 | if (flags & MSG_TRUNC) | |
551 | copied = skb->len; | |
552 | done: | |
553 | skb_free_datagram(sk, skb); | |
554 | out: | |
c8657fd5 | 555 | return err ? err : copied; |
0d76751f JC |
556 | } |
557 | ||
72fb96e7 ED |
558 | int l2tp_ioctl(struct sock *sk, int cmd, unsigned long arg) |
559 | { | |
560 | struct sk_buff *skb; | |
561 | int amount; | |
562 | ||
563 | switch (cmd) { | |
564 | case SIOCOUTQ: | |
565 | amount = sk_wmem_alloc_get(sk); | |
566 | break; | |
567 | case SIOCINQ: | |
568 | spin_lock_bh(&sk->sk_receive_queue.lock); | |
569 | skb = skb_peek(&sk->sk_receive_queue); | |
570 | amount = skb ? skb->len : 0; | |
571 | spin_unlock_bh(&sk->sk_receive_queue.lock); | |
572 | break; | |
573 | ||
574 | default: | |
575 | return -ENOIOCTLCMD; | |
576 | } | |
577 | ||
578 | return put_user(amount, (int __user *)arg); | |
579 | } | |
580 | EXPORT_SYMBOL(l2tp_ioctl); | |
581 | ||
fc130840 | 582 | static struct proto l2tp_ip_prot = { |
0d76751f JC |
583 | .name = "L2TP/IP", |
584 | .owner = THIS_MODULE, | |
585 | .init = l2tp_ip_open, | |
586 | .close = l2tp_ip_close, | |
587 | .bind = l2tp_ip_bind, | |
588 | .connect = l2tp_ip_connect, | |
c51ce497 | 589 | .disconnect = l2tp_ip_disconnect, |
72fb96e7 | 590 | .ioctl = l2tp_ioctl, |
0d76751f JC |
591 | .destroy = l2tp_ip_destroy_sock, |
592 | .setsockopt = ip_setsockopt, | |
593 | .getsockopt = ip_getsockopt, | |
594 | .sendmsg = l2tp_ip_sendmsg, | |
595 | .recvmsg = l2tp_ip_recvmsg, | |
596 | .backlog_rcv = l2tp_ip_backlog_recv, | |
597 | .hash = inet_hash, | |
598 | .unhash = inet_unhash, | |
599 | .obj_size = sizeof(struct l2tp_ip_sock), | |
600 | #ifdef CONFIG_COMPAT | |
601 | .compat_setsockopt = compat_ip_setsockopt, | |
602 | .compat_getsockopt = compat_ip_getsockopt, | |
603 | #endif | |
604 | }; | |
605 | ||
606 | static const struct proto_ops l2tp_ip_ops = { | |
607 | .family = PF_INET, | |
608 | .owner = THIS_MODULE, | |
609 | .release = inet_release, | |
610 | .bind = inet_bind, | |
611 | .connect = inet_dgram_connect, | |
612 | .socketpair = sock_no_socketpair, | |
613 | .accept = sock_no_accept, | |
614 | .getname = l2tp_ip_getname, | |
a11e1d43 | 615 | .poll = datagram_poll, |
0d76751f | 616 | .ioctl = inet_ioctl, |
c7cbdbf2 | 617 | .gettstamp = sock_gettstamp, |
0d76751f JC |
618 | .listen = sock_no_listen, |
619 | .shutdown = inet_shutdown, | |
620 | .setsockopt = sock_common_setsockopt, | |
621 | .getsockopt = sock_common_getsockopt, | |
622 | .sendmsg = inet_sendmsg, | |
623 | .recvmsg = sock_common_recvmsg, | |
624 | .mmap = sock_no_mmap, | |
625 | .sendpage = sock_no_sendpage, | |
626 | #ifdef CONFIG_COMPAT | |
627 | .compat_setsockopt = compat_sock_common_setsockopt, | |
628 | .compat_getsockopt = compat_sock_common_getsockopt, | |
629 | #endif | |
630 | }; | |
631 | ||
632 | static struct inet_protosw l2tp_ip_protosw = { | |
633 | .type = SOCK_DGRAM, | |
634 | .protocol = IPPROTO_L2TP, | |
635 | .prot = &l2tp_ip_prot, | |
636 | .ops = &l2tp_ip_ops, | |
0d76751f JC |
637 | }; |
638 | ||
639 | static struct net_protocol l2tp_ip_protocol __read_mostly = { | |
640 | .handler = l2tp_ip_recv, | |
9d6ddb19 | 641 | .netns_ok = 1, |
0d76751f JC |
642 | }; |
643 | ||
644 | static int __init l2tp_ip_init(void) | |
645 | { | |
646 | int err; | |
647 | ||
a4ca44fa | 648 | pr_info("L2TP IP encapsulation support (L2TPv3)\n"); |
0d76751f JC |
649 | |
650 | err = proto_register(&l2tp_ip_prot, 1); | |
651 | if (err != 0) | |
652 | goto out; | |
653 | ||
654 | err = inet_add_protocol(&l2tp_ip_protocol, IPPROTO_L2TP); | |
655 | if (err) | |
656 | goto out1; | |
657 | ||
658 | inet_register_protosw(&l2tp_ip_protosw); | |
659 | return 0; | |
660 | ||
661 | out1: | |
662 | proto_unregister(&l2tp_ip_prot); | |
663 | out: | |
664 | return err; | |
665 | } | |
666 | ||
667 | static void __exit l2tp_ip_exit(void) | |
668 | { | |
669 | inet_unregister_protosw(&l2tp_ip_protosw); | |
670 | inet_del_protocol(&l2tp_ip_protocol, IPPROTO_L2TP); | |
671 | proto_unregister(&l2tp_ip_prot); | |
672 | } | |
673 | ||
674 | module_init(l2tp_ip_init); | |
675 | module_exit(l2tp_ip_exit); | |
676 | ||
677 | MODULE_LICENSE("GPL"); | |
678 | MODULE_AUTHOR("James Chapman <jchapman@katalix.com>"); | |
679 | MODULE_DESCRIPTION("L2TP over IP"); | |
680 | MODULE_VERSION("1.0"); | |
e8d34a88 | 681 | |
e9c54999 | 682 | /* Use the value of SOCK_DGRAM (2) directory, because __stringify doesn't like |
e8d34a88 MM |
683 | * enums |
684 | */ | |
685 | MODULE_ALIAS_NET_PF_PROTO_TYPE(PF_INET, 2, IPPROTO_L2TP); | |
163c2e25 | 686 | MODULE_ALIAS_NET_PF_PROTO(PF_INET, IPPROTO_L2TP); |