1 /*
2  * L2TP netlink layer, for management
3  *
4  * Copyright (c) 2008,2009,2010 Katalix Systems Ltd
5  *
6  * Partly based on the IrDA nelink implementation
7  * (see net/irda/irnetlink.c) which is:
8  * Copyright (c) 2007 Samuel Ortiz <samuel@sortiz.org>
9  * which is in turn partly based on the wireless netlink code:
10  * Copyright 2006 Johannes Berg <johannes@sipsolutions.net>
11  *
12  * This program is free software; you can redistribute it and/or modify
13  * it under the terms of the GNU General Public License version 2 as
14  * published by the Free Software Foundation.
15  */
16 
17 #include <net/sock.h>
18 #include <net/genetlink.h>
19 #include <net/udp.h>
20 #include <linux/in.h>
21 #include <linux/udp.h>
22 #include <linux/socket.h>
23 #include <linux/module.h>
24 #include <linux/list.h>
25 #include <net/net_namespace.h>
26 
27 #include <linux/l2tp.h>
28 
29 #include "l2tp_core.h"
30 
31 
32 static struct genl_family l2tp_nl_family = {
33 	.id		= GENL_ID_GENERATE,
34 	.name		= L2TP_GENL_NAME,
35 	.version	= L2TP_GENL_VERSION,
36 	.hdrsize	= 0,
37 	.maxattr	= L2TP_ATTR_MAX,
38 };
39 
40 /* Accessed under genl lock */
41 static const struct l2tp_nl_cmd_ops *l2tp_nl_cmd_ops[__L2TP_PWTYPE_MAX];
42 
l2tp_nl_session_find(struct genl_info * info)43 static struct l2tp_session *l2tp_nl_session_find(struct genl_info *info)
44 {
45 	u32 tunnel_id;
46 	u32 session_id;
47 	char *ifname;
48 	struct l2tp_tunnel *tunnel;
49 	struct l2tp_session *session = NULL;
50 	struct net *net = genl_info_net(info);
51 
52 	if (info->attrs[L2TP_ATTR_IFNAME]) {
53 		ifname = nla_data(info->attrs[L2TP_ATTR_IFNAME]);
54 		session = l2tp_session_find_by_ifname(net, ifname);
55 	} else if ((info->attrs[L2TP_ATTR_SESSION_ID]) &&
56 		   (info->attrs[L2TP_ATTR_CONN_ID])) {
57 		tunnel_id = nla_get_u32(info->attrs[L2TP_ATTR_CONN_ID]);
58 		session_id = nla_get_u32(info->attrs[L2TP_ATTR_SESSION_ID]);
59 		tunnel = l2tp_tunnel_find(net, tunnel_id);
60 		if (tunnel)
61 			session = l2tp_session_find(net, tunnel, session_id);
62 	}
63 
64 	return session;
65 }
66 
l2tp_nl_cmd_noop(struct sk_buff * skb,struct genl_info * info)67 static int l2tp_nl_cmd_noop(struct sk_buff *skb, struct genl_info *info)
68 {
69 	struct sk_buff *msg;
70 	void *hdr;
71 	int ret = -ENOBUFS;
72 
73 	msg = nlmsg_new(NLMSG_GOODSIZE, GFP_KERNEL);
74 	if (!msg) {
75 		ret = -ENOMEM;
76 		goto out;
77 	}
78 
79 	hdr = genlmsg_put(msg, info->snd_pid, info->snd_seq,
80 			  &l2tp_nl_family, 0, L2TP_CMD_NOOP);
81 	if (IS_ERR(hdr)) {
82 		ret = PTR_ERR(hdr);
83 		goto err_out;
84 	}
85 
86 	genlmsg_end(msg, hdr);
87 
88 	return genlmsg_unicast(genl_info_net(info), msg, info->snd_pid);
89 
90 err_out:
91 	nlmsg_free(msg);
92 
93 out:
94 	return ret;
95 }
96 
l2tp_nl_cmd_tunnel_create(struct sk_buff * skb,struct genl_info * info)97 static int l2tp_nl_cmd_tunnel_create(struct sk_buff *skb, struct genl_info *info)
98 {
99 	u32 tunnel_id;
100 	u32 peer_tunnel_id;
101 	int proto_version;
102 	int fd;
103 	int ret = 0;
104 	struct l2tp_tunnel_cfg cfg = { 0, };
105 	struct l2tp_tunnel *tunnel;
106 	struct net *net = genl_info_net(info);
107 
108 	if (!info->attrs[L2TP_ATTR_CONN_ID]) {
109 		ret = -EINVAL;
110 		goto out;
111 	}
112 	tunnel_id = nla_get_u32(info->attrs[L2TP_ATTR_CONN_ID]);
113 
114 	if (!info->attrs[L2TP_ATTR_PEER_CONN_ID]) {
115 		ret = -EINVAL;
116 		goto out;
117 	}
118 	peer_tunnel_id = nla_get_u32(info->attrs[L2TP_ATTR_PEER_CONN_ID]);
119 
120 	if (!info->attrs[L2TP_ATTR_PROTO_VERSION]) {
121 		ret = -EINVAL;
122 		goto out;
123 	}
124 	proto_version = nla_get_u8(info->attrs[L2TP_ATTR_PROTO_VERSION]);
125 
126 	if (!info->attrs[L2TP_ATTR_ENCAP_TYPE]) {
127 		ret = -EINVAL;
128 		goto out;
129 	}
130 	cfg.encap = nla_get_u16(info->attrs[L2TP_ATTR_ENCAP_TYPE]);
131 
132 	fd = -1;
133 	if (info->attrs[L2TP_ATTR_FD]) {
134 		fd = nla_get_u32(info->attrs[L2TP_ATTR_FD]);
135 	} else {
136 		if (info->attrs[L2TP_ATTR_IP_SADDR])
137 			cfg.local_ip.s_addr = nla_get_be32(info->attrs[L2TP_ATTR_IP_SADDR]);
138 		if (info->attrs[L2TP_ATTR_IP_DADDR])
139 			cfg.peer_ip.s_addr = nla_get_be32(info->attrs[L2TP_ATTR_IP_DADDR]);
140 		if (info->attrs[L2TP_ATTR_UDP_SPORT])
141 			cfg.local_udp_port = nla_get_u16(info->attrs[L2TP_ATTR_UDP_SPORT]);
142 		if (info->attrs[L2TP_ATTR_UDP_DPORT])
143 			cfg.peer_udp_port = nla_get_u16(info->attrs[L2TP_ATTR_UDP_DPORT]);
144 		if (info->attrs[L2TP_ATTR_UDP_CSUM])
145 			cfg.use_udp_checksums = nla_get_flag(info->attrs[L2TP_ATTR_UDP_CSUM]);
146 	}
147 
148 	if (info->attrs[L2TP_ATTR_DEBUG])
149 		cfg.debug = nla_get_u32(info->attrs[L2TP_ATTR_DEBUG]);
150 
151 	tunnel = l2tp_tunnel_find(net, tunnel_id);
152 	if (tunnel != NULL) {
153 		ret = -EEXIST;
154 		goto out;
155 	}
156 
157 	ret = -EINVAL;
158 	switch (cfg.encap) {
159 	case L2TP_ENCAPTYPE_UDP:
160 	case L2TP_ENCAPTYPE_IP:
161 		ret = l2tp_tunnel_create(net, fd, proto_version, tunnel_id,
162 					 peer_tunnel_id, &cfg, &tunnel);
163 		break;
164 	}
165 
166 out:
167 	return ret;
168 }
169 
l2tp_nl_cmd_tunnel_delete(struct sk_buff * skb,struct genl_info * info)170 static int l2tp_nl_cmd_tunnel_delete(struct sk_buff *skb, struct genl_info *info)
171 {
172 	struct l2tp_tunnel *tunnel;
173 	u32 tunnel_id;
174 	int ret = 0;
175 	struct net *net = genl_info_net(info);
176 
177 	if (!info->attrs[L2TP_ATTR_CONN_ID]) {
178 		ret = -EINVAL;
179 		goto out;
180 	}
181 	tunnel_id = nla_get_u32(info->attrs[L2TP_ATTR_CONN_ID]);
182 
183 	tunnel = l2tp_tunnel_find(net, tunnel_id);
184 	if (tunnel == NULL) {
185 		ret = -ENODEV;
186 		goto out;
187 	}
188 
189 	(void) l2tp_tunnel_delete(tunnel);
190 
191 out:
192 	return ret;
193 }
194 
l2tp_nl_cmd_tunnel_modify(struct sk_buff * skb,struct genl_info * info)195 static int l2tp_nl_cmd_tunnel_modify(struct sk_buff *skb, struct genl_info *info)
196 {
197 	struct l2tp_tunnel *tunnel;
198 	u32 tunnel_id;
199 	int ret = 0;
200 	struct net *net = genl_info_net(info);
201 
202 	if (!info->attrs[L2TP_ATTR_CONN_ID]) {
203 		ret = -EINVAL;
204 		goto out;
205 	}
206 	tunnel_id = nla_get_u32(info->attrs[L2TP_ATTR_CONN_ID]);
207 
208 	tunnel = l2tp_tunnel_find(net, tunnel_id);
209 	if (tunnel == NULL) {
210 		ret = -ENODEV;
211 		goto out;
212 	}
213 
214 	if (info->attrs[L2TP_ATTR_DEBUG])
215 		tunnel->debug = nla_get_u32(info->attrs[L2TP_ATTR_DEBUG]);
216 
217 out:
218 	return ret;
219 }
220 
l2tp_nl_tunnel_send(struct sk_buff * skb,u32 pid,u32 seq,int flags,struct l2tp_tunnel * tunnel)221 static int l2tp_nl_tunnel_send(struct sk_buff *skb, u32 pid, u32 seq, int flags,
222 			       struct l2tp_tunnel *tunnel)
223 {
224 	void *hdr;
225 	struct nlattr *nest;
226 	struct sock *sk = NULL;
227 	struct inet_sock *inet;
228 
229 	hdr = genlmsg_put(skb, pid, seq, &l2tp_nl_family, flags,
230 			  L2TP_CMD_TUNNEL_GET);
231 	if (IS_ERR(hdr))
232 		return PTR_ERR(hdr);
233 
234 	NLA_PUT_U8(skb, L2TP_ATTR_PROTO_VERSION, tunnel->version);
235 	NLA_PUT_U32(skb, L2TP_ATTR_CONN_ID, tunnel->tunnel_id);
236 	NLA_PUT_U32(skb, L2TP_ATTR_PEER_CONN_ID, tunnel->peer_tunnel_id);
237 	NLA_PUT_U32(skb, L2TP_ATTR_DEBUG, tunnel->debug);
238 	NLA_PUT_U16(skb, L2TP_ATTR_ENCAP_TYPE, tunnel->encap);
239 
240 	nest = nla_nest_start(skb, L2TP_ATTR_STATS);
241 	if (nest == NULL)
242 		goto nla_put_failure;
243 
244 	NLA_PUT_U64(skb, L2TP_ATTR_TX_PACKETS, tunnel->stats.tx_packets);
245 	NLA_PUT_U64(skb, L2TP_ATTR_TX_BYTES, tunnel->stats.tx_bytes);
246 	NLA_PUT_U64(skb, L2TP_ATTR_TX_ERRORS, tunnel->stats.tx_errors);
247 	NLA_PUT_U64(skb, L2TP_ATTR_RX_PACKETS, tunnel->stats.rx_packets);
248 	NLA_PUT_U64(skb, L2TP_ATTR_RX_BYTES, tunnel->stats.rx_bytes);
249 	NLA_PUT_U64(skb, L2TP_ATTR_RX_SEQ_DISCARDS, tunnel->stats.rx_seq_discards);
250 	NLA_PUT_U64(skb, L2TP_ATTR_RX_OOS_PACKETS, tunnel->stats.rx_oos_packets);
251 	NLA_PUT_U64(skb, L2TP_ATTR_RX_ERRORS, tunnel->stats.rx_errors);
252 	nla_nest_end(skb, nest);
253 
254 	sk = tunnel->sock;
255 	if (!sk)
256 		goto out;
257 
258 	inet = inet_sk(sk);
259 
260 	switch (tunnel->encap) {
261 	case L2TP_ENCAPTYPE_UDP:
262 		NLA_PUT_U16(skb, L2TP_ATTR_UDP_SPORT, ntohs(inet->inet_sport));
263 		NLA_PUT_U16(skb, L2TP_ATTR_UDP_DPORT, ntohs(inet->inet_dport));
264 		NLA_PUT_U8(skb, L2TP_ATTR_UDP_CSUM, (sk->sk_no_check != UDP_CSUM_NOXMIT));
265 		/* NOBREAK */
266 	case L2TP_ENCAPTYPE_IP:
267 		NLA_PUT_BE32(skb, L2TP_ATTR_IP_SADDR, inet->inet_saddr);
268 		NLA_PUT_BE32(skb, L2TP_ATTR_IP_DADDR, inet->inet_daddr);
269 		break;
270 	}
271 
272 out:
273 	return genlmsg_end(skb, hdr);
274 
275 nla_put_failure:
276 	genlmsg_cancel(skb, hdr);
277 	return -1;
278 }
279 
l2tp_nl_cmd_tunnel_get(struct sk_buff * skb,struct genl_info * info)280 static int l2tp_nl_cmd_tunnel_get(struct sk_buff *skb, struct genl_info *info)
281 {
282 	struct l2tp_tunnel *tunnel;
283 	struct sk_buff *msg;
284 	u32 tunnel_id;
285 	int ret = -ENOBUFS;
286 	struct net *net = genl_info_net(info);
287 
288 	if (!info->attrs[L2TP_ATTR_CONN_ID]) {
289 		ret = -EINVAL;
290 		goto out;
291 	}
292 
293 	tunnel_id = nla_get_u32(info->attrs[L2TP_ATTR_CONN_ID]);
294 
295 	tunnel = l2tp_tunnel_find(net, tunnel_id);
296 	if (tunnel == NULL) {
297 		ret = -ENODEV;
298 		goto out;
299 	}
300 
301 	msg = nlmsg_new(NLMSG_GOODSIZE, GFP_KERNEL);
302 	if (!msg) {
303 		ret = -ENOMEM;
304 		goto out;
305 	}
306 
307 	ret = l2tp_nl_tunnel_send(msg, info->snd_pid, info->snd_seq,
308 				  NLM_F_ACK, tunnel);
309 	if (ret < 0)
310 		goto err_out;
311 
312 	return genlmsg_unicast(net, msg, info->snd_pid);
313 
314 err_out:
315 	nlmsg_free(msg);
316 
317 out:
318 	return ret;
319 }
320 
l2tp_nl_cmd_tunnel_dump(struct sk_buff * skb,struct netlink_callback * cb)321 static int l2tp_nl_cmd_tunnel_dump(struct sk_buff *skb, struct netlink_callback *cb)
322 {
323 	int ti = cb->args[0];
324 	struct l2tp_tunnel *tunnel;
325 	struct net *net = sock_net(skb->sk);
326 
327 	for (;;) {
328 		tunnel = l2tp_tunnel_find_nth(net, ti);
329 		if (tunnel == NULL)
330 			goto out;
331 
332 		if (l2tp_nl_tunnel_send(skb, NETLINK_CB(cb->skb).pid,
333 					cb->nlh->nlmsg_seq, NLM_F_MULTI,
334 					tunnel) <= 0)
335 			goto out;
336 
337 		ti++;
338 	}
339 
340 out:
341 	cb->args[0] = ti;
342 
343 	return skb->len;
344 }
345 
l2tp_nl_cmd_session_create(struct sk_buff * skb,struct genl_info * info)346 static int l2tp_nl_cmd_session_create(struct sk_buff *skb, struct genl_info *info)
347 {
348 	u32 tunnel_id = 0;
349 	u32 session_id;
350 	u32 peer_session_id;
351 	int ret = 0;
352 	struct l2tp_tunnel *tunnel;
353 	struct l2tp_session *session;
354 	struct l2tp_session_cfg cfg = { 0, };
355 	struct net *net = genl_info_net(info);
356 
357 	if (!info->attrs[L2TP_ATTR_CONN_ID]) {
358 		ret = -EINVAL;
359 		goto out;
360 	}
361 	tunnel_id = nla_get_u32(info->attrs[L2TP_ATTR_CONN_ID]);
362 	tunnel = l2tp_tunnel_find(net, tunnel_id);
363 	if (!tunnel) {
364 		ret = -ENODEV;
365 		goto out;
366 	}
367 
368 	if (!info->attrs[L2TP_ATTR_SESSION_ID]) {
369 		ret = -EINVAL;
370 		goto out;
371 	}
372 	session_id = nla_get_u32(info->attrs[L2TP_ATTR_SESSION_ID]);
373 	session = l2tp_session_find(net, tunnel, session_id);
374 	if (session) {
375 		ret = -EEXIST;
376 		goto out;
377 	}
378 
379 	if (!info->attrs[L2TP_ATTR_PEER_SESSION_ID]) {
380 		ret = -EINVAL;
381 		goto out;
382 	}
383 	peer_session_id = nla_get_u32(info->attrs[L2TP_ATTR_PEER_SESSION_ID]);
384 
385 	if (!info->attrs[L2TP_ATTR_PW_TYPE]) {
386 		ret = -EINVAL;
387 		goto out;
388 	}
389 	cfg.pw_type = nla_get_u16(info->attrs[L2TP_ATTR_PW_TYPE]);
390 	if (cfg.pw_type >= __L2TP_PWTYPE_MAX) {
391 		ret = -EINVAL;
392 		goto out;
393 	}
394 
395 	if (tunnel->version > 2) {
396 		if (info->attrs[L2TP_ATTR_OFFSET])
397 			cfg.offset = nla_get_u16(info->attrs[L2TP_ATTR_OFFSET]);
398 
399 		if (info->attrs[L2TP_ATTR_DATA_SEQ])
400 			cfg.data_seq = nla_get_u8(info->attrs[L2TP_ATTR_DATA_SEQ]);
401 
402 		cfg.l2specific_type = L2TP_L2SPECTYPE_DEFAULT;
403 		if (info->attrs[L2TP_ATTR_L2SPEC_TYPE])
404 			cfg.l2specific_type = nla_get_u8(info->attrs[L2TP_ATTR_L2SPEC_TYPE]);
405 
406 		cfg.l2specific_len = 4;
407 		if (info->attrs[L2TP_ATTR_L2SPEC_LEN])
408 			cfg.l2specific_len = nla_get_u8(info->attrs[L2TP_ATTR_L2SPEC_LEN]);
409 
410 		if (info->attrs[L2TP_ATTR_COOKIE]) {
411 			u16 len = nla_len(info->attrs[L2TP_ATTR_COOKIE]);
412 			if (len > 8) {
413 				ret = -EINVAL;
414 				goto out;
415 			}
416 			cfg.cookie_len = len;
417 			memcpy(&cfg.cookie[0], nla_data(info->attrs[L2TP_ATTR_COOKIE]), len);
418 		}
419 		if (info->attrs[L2TP_ATTR_PEER_COOKIE]) {
420 			u16 len = nla_len(info->attrs[L2TP_ATTR_PEER_COOKIE]);
421 			if (len > 8) {
422 				ret = -EINVAL;
423 				goto out;
424 			}
425 			cfg.peer_cookie_len = len;
426 			memcpy(&cfg.peer_cookie[0], nla_data(info->attrs[L2TP_ATTR_PEER_COOKIE]), len);
427 		}
428 		if (info->attrs[L2TP_ATTR_IFNAME])
429 			cfg.ifname = nla_data(info->attrs[L2TP_ATTR_IFNAME]);
430 
431 		if (info->attrs[L2TP_ATTR_VLAN_ID])
432 			cfg.vlan_id = nla_get_u16(info->attrs[L2TP_ATTR_VLAN_ID]);
433 	}
434 
435 	if (info->attrs[L2TP_ATTR_DEBUG])
436 		cfg.debug = nla_get_u32(info->attrs[L2TP_ATTR_DEBUG]);
437 
438 	if (info->attrs[L2TP_ATTR_RECV_SEQ])
439 		cfg.recv_seq = nla_get_u8(info->attrs[L2TP_ATTR_RECV_SEQ]);
440 
441 	if (info->attrs[L2TP_ATTR_SEND_SEQ])
442 		cfg.send_seq = nla_get_u8(info->attrs[L2TP_ATTR_SEND_SEQ]);
443 
444 	if (info->attrs[L2TP_ATTR_LNS_MODE])
445 		cfg.lns_mode = nla_get_u8(info->attrs[L2TP_ATTR_LNS_MODE]);
446 
447 	if (info->attrs[L2TP_ATTR_RECV_TIMEOUT])
448 		cfg.reorder_timeout = nla_get_msecs(info->attrs[L2TP_ATTR_RECV_TIMEOUT]);
449 
450 	if (info->attrs[L2TP_ATTR_MTU])
451 		cfg.mtu = nla_get_u16(info->attrs[L2TP_ATTR_MTU]);
452 
453 	if (info->attrs[L2TP_ATTR_MRU])
454 		cfg.mru = nla_get_u16(info->attrs[L2TP_ATTR_MRU]);
455 
456 	if ((l2tp_nl_cmd_ops[cfg.pw_type] == NULL) ||
457 	    (l2tp_nl_cmd_ops[cfg.pw_type]->session_create == NULL)) {
458 		ret = -EPROTONOSUPPORT;
459 		goto out;
460 	}
461 
462 	/* Check that pseudowire-specific params are present */
463 	switch (cfg.pw_type) {
464 	case L2TP_PWTYPE_NONE:
465 		break;
466 	case L2TP_PWTYPE_ETH_VLAN:
467 		if (!info->attrs[L2TP_ATTR_VLAN_ID]) {
468 			ret = -EINVAL;
469 			goto out;
470 		}
471 		break;
472 	case L2TP_PWTYPE_ETH:
473 		break;
474 	case L2TP_PWTYPE_PPP:
475 	case L2TP_PWTYPE_PPP_AC:
476 		break;
477 	case L2TP_PWTYPE_IP:
478 	default:
479 		ret = -EPROTONOSUPPORT;
480 		break;
481 	}
482 
483 	ret = -EPROTONOSUPPORT;
484 	if (l2tp_nl_cmd_ops[cfg.pw_type]->session_create)
485 		ret = (*l2tp_nl_cmd_ops[cfg.pw_type]->session_create)(net, tunnel_id,
486 			session_id, peer_session_id, &cfg);
487 
488 out:
489 	return ret;
490 }
491 
l2tp_nl_cmd_session_delete(struct sk_buff * skb,struct genl_info * info)492 static int l2tp_nl_cmd_session_delete(struct sk_buff *skb, struct genl_info *info)
493 {
494 	int ret = 0;
495 	struct l2tp_session *session;
496 	u16 pw_type;
497 
498 	session = l2tp_nl_session_find(info);
499 	if (session == NULL) {
500 		ret = -ENODEV;
501 		goto out;
502 	}
503 
504 	pw_type = session->pwtype;
505 	if (pw_type < __L2TP_PWTYPE_MAX)
506 		if (l2tp_nl_cmd_ops[pw_type] && l2tp_nl_cmd_ops[pw_type]->session_delete)
507 			ret = (*l2tp_nl_cmd_ops[pw_type]->session_delete)(session);
508 
509 out:
510 	return ret;
511 }
512 
l2tp_nl_cmd_session_modify(struct sk_buff * skb,struct genl_info * info)513 static int l2tp_nl_cmd_session_modify(struct sk_buff *skb, struct genl_info *info)
514 {
515 	int ret = 0;
516 	struct l2tp_session *session;
517 
518 	session = l2tp_nl_session_find(info);
519 	if (session == NULL) {
520 		ret = -ENODEV;
521 		goto out;
522 	}
523 
524 	if (info->attrs[L2TP_ATTR_DEBUG])
525 		session->debug = nla_get_u32(info->attrs[L2TP_ATTR_DEBUG]);
526 
527 	if (info->attrs[L2TP_ATTR_DATA_SEQ])
528 		session->data_seq = nla_get_u8(info->attrs[L2TP_ATTR_DATA_SEQ]);
529 
530 	if (info->attrs[L2TP_ATTR_RECV_SEQ])
531 		session->recv_seq = nla_get_u8(info->attrs[L2TP_ATTR_RECV_SEQ]);
532 
533 	if (info->attrs[L2TP_ATTR_SEND_SEQ])
534 		session->send_seq = nla_get_u8(info->attrs[L2TP_ATTR_SEND_SEQ]);
535 
536 	if (info->attrs[L2TP_ATTR_LNS_MODE])
537 		session->lns_mode = nla_get_u8(info->attrs[L2TP_ATTR_LNS_MODE]);
538 
539 	if (info->attrs[L2TP_ATTR_RECV_TIMEOUT])
540 		session->reorder_timeout = nla_get_msecs(info->attrs[L2TP_ATTR_RECV_TIMEOUT]);
541 
542 	if (info->attrs[L2TP_ATTR_MTU])
543 		session->mtu = nla_get_u16(info->attrs[L2TP_ATTR_MTU]);
544 
545 	if (info->attrs[L2TP_ATTR_MRU])
546 		session->mru = nla_get_u16(info->attrs[L2TP_ATTR_MRU]);
547 
548 out:
549 	return ret;
550 }
551 
l2tp_nl_session_send(struct sk_buff * skb,u32 pid,u32 seq,int flags,struct l2tp_session * session)552 static int l2tp_nl_session_send(struct sk_buff *skb, u32 pid, u32 seq, int flags,
553 				struct l2tp_session *session)
554 {
555 	void *hdr;
556 	struct nlattr *nest;
557 	struct l2tp_tunnel *tunnel = session->tunnel;
558 	struct sock *sk = NULL;
559 
560 	sk = tunnel->sock;
561 
562 	hdr = genlmsg_put(skb, pid, seq, &l2tp_nl_family, flags, L2TP_CMD_SESSION_GET);
563 	if (IS_ERR(hdr))
564 		return PTR_ERR(hdr);
565 
566 	NLA_PUT_U32(skb, L2TP_ATTR_CONN_ID, tunnel->tunnel_id);
567 	NLA_PUT_U32(skb, L2TP_ATTR_SESSION_ID, session->session_id);
568 	NLA_PUT_U32(skb, L2TP_ATTR_PEER_CONN_ID, tunnel->peer_tunnel_id);
569 	NLA_PUT_U32(skb, L2TP_ATTR_PEER_SESSION_ID, session->peer_session_id);
570 	NLA_PUT_U32(skb, L2TP_ATTR_DEBUG, session->debug);
571 	NLA_PUT_U16(skb, L2TP_ATTR_PW_TYPE, session->pwtype);
572 	NLA_PUT_U16(skb, L2TP_ATTR_MTU, session->mtu);
573 	if (session->mru)
574 		NLA_PUT_U16(skb, L2TP_ATTR_MRU, session->mru);
575 
576 	if (session->ifname && session->ifname[0])
577 		NLA_PUT_STRING(skb, L2TP_ATTR_IFNAME, session->ifname);
578 	if (session->cookie_len)
579 		NLA_PUT(skb, L2TP_ATTR_COOKIE, session->cookie_len, &session->cookie[0]);
580 	if (session->peer_cookie_len)
581 		NLA_PUT(skb, L2TP_ATTR_PEER_COOKIE, session->peer_cookie_len, &session->peer_cookie[0]);
582 	NLA_PUT_U8(skb, L2TP_ATTR_RECV_SEQ, session->recv_seq);
583 	NLA_PUT_U8(skb, L2TP_ATTR_SEND_SEQ, session->send_seq);
584 	NLA_PUT_U8(skb, L2TP_ATTR_LNS_MODE, session->lns_mode);
585 #ifdef CONFIG_XFRM
586 	if ((sk) && (sk->sk_policy[0] || sk->sk_policy[1]))
587 		NLA_PUT_U8(skb, L2TP_ATTR_USING_IPSEC, 1);
588 #endif
589 	if (session->reorder_timeout)
590 		NLA_PUT_MSECS(skb, L2TP_ATTR_RECV_TIMEOUT, session->reorder_timeout);
591 
592 	nest = nla_nest_start(skb, L2TP_ATTR_STATS);
593 	if (nest == NULL)
594 		goto nla_put_failure;
595 	NLA_PUT_U64(skb, L2TP_ATTR_TX_PACKETS, session->stats.tx_packets);
596 	NLA_PUT_U64(skb, L2TP_ATTR_TX_BYTES, session->stats.tx_bytes);
597 	NLA_PUT_U64(skb, L2TP_ATTR_TX_ERRORS, session->stats.tx_errors);
598 	NLA_PUT_U64(skb, L2TP_ATTR_RX_PACKETS, session->stats.rx_packets);
599 	NLA_PUT_U64(skb, L2TP_ATTR_RX_BYTES, session->stats.rx_bytes);
600 	NLA_PUT_U64(skb, L2TP_ATTR_RX_SEQ_DISCARDS, session->stats.rx_seq_discards);
601 	NLA_PUT_U64(skb, L2TP_ATTR_RX_OOS_PACKETS, session->stats.rx_oos_packets);
602 	NLA_PUT_U64(skb, L2TP_ATTR_RX_ERRORS, session->stats.rx_errors);
603 	nla_nest_end(skb, nest);
604 
605 	return genlmsg_end(skb, hdr);
606 
607  nla_put_failure:
608 	genlmsg_cancel(skb, hdr);
609 	return -1;
610 }
611 
l2tp_nl_cmd_session_get(struct sk_buff * skb,struct genl_info * info)612 static int l2tp_nl_cmd_session_get(struct sk_buff *skb, struct genl_info *info)
613 {
614 	struct l2tp_session *session;
615 	struct sk_buff *msg;
616 	int ret;
617 
618 	session = l2tp_nl_session_find(info);
619 	if (session == NULL) {
620 		ret = -ENODEV;
621 		goto out;
622 	}
623 
624 	msg = nlmsg_new(NLMSG_GOODSIZE, GFP_KERNEL);
625 	if (!msg) {
626 		ret = -ENOMEM;
627 		goto out;
628 	}
629 
630 	ret = l2tp_nl_session_send(msg, info->snd_pid, info->snd_seq,
631 				   0, session);
632 	if (ret < 0)
633 		goto err_out;
634 
635 	return genlmsg_unicast(genl_info_net(info), msg, info->snd_pid);
636 
637 err_out:
638 	nlmsg_free(msg);
639 
640 out:
641 	return ret;
642 }
643 
l2tp_nl_cmd_session_dump(struct sk_buff * skb,struct netlink_callback * cb)644 static int l2tp_nl_cmd_session_dump(struct sk_buff *skb, struct netlink_callback *cb)
645 {
646 	struct net *net = sock_net(skb->sk);
647 	struct l2tp_session *session;
648 	struct l2tp_tunnel *tunnel = NULL;
649 	int ti = cb->args[0];
650 	int si = cb->args[1];
651 
652 	for (;;) {
653 		if (tunnel == NULL) {
654 			tunnel = l2tp_tunnel_find_nth(net, ti);
655 			if (tunnel == NULL)
656 				goto out;
657 		}
658 
659 		session = l2tp_session_find_nth(tunnel, si);
660 		if (session == NULL) {
661 			ti++;
662 			tunnel = NULL;
663 			si = 0;
664 			continue;
665 		}
666 
667 		if (l2tp_nl_session_send(skb, NETLINK_CB(cb->skb).pid,
668 					 cb->nlh->nlmsg_seq, NLM_F_MULTI,
669 					 session) <= 0)
670 			break;
671 
672 		si++;
673 	}
674 
675 out:
676 	cb->args[0] = ti;
677 	cb->args[1] = si;
678 
679 	return skb->len;
680 }
681 
682 static struct nla_policy l2tp_nl_policy[L2TP_ATTR_MAX + 1] = {
683 	[L2TP_ATTR_NONE]		= { .type = NLA_UNSPEC, },
684 	[L2TP_ATTR_PW_TYPE]		= { .type = NLA_U16, },
685 	[L2TP_ATTR_ENCAP_TYPE]		= { .type = NLA_U16, },
686 	[L2TP_ATTR_OFFSET]		= { .type = NLA_U16, },
687 	[L2TP_ATTR_DATA_SEQ]		= { .type = NLA_U8, },
688 	[L2TP_ATTR_L2SPEC_TYPE]		= { .type = NLA_U8, },
689 	[L2TP_ATTR_L2SPEC_LEN]		= { .type = NLA_U8, },
690 	[L2TP_ATTR_PROTO_VERSION]	= { .type = NLA_U8, },
691 	[L2TP_ATTR_CONN_ID]		= { .type = NLA_U32, },
692 	[L2TP_ATTR_PEER_CONN_ID]	= { .type = NLA_U32, },
693 	[L2TP_ATTR_SESSION_ID]		= { .type = NLA_U32, },
694 	[L2TP_ATTR_PEER_SESSION_ID]	= { .type = NLA_U32, },
695 	[L2TP_ATTR_UDP_CSUM]		= { .type = NLA_U8, },
696 	[L2TP_ATTR_VLAN_ID]		= { .type = NLA_U16, },
697 	[L2TP_ATTR_DEBUG]		= { .type = NLA_U32, },
698 	[L2TP_ATTR_RECV_SEQ]		= { .type = NLA_U8, },
699 	[L2TP_ATTR_SEND_SEQ]		= { .type = NLA_U8, },
700 	[L2TP_ATTR_LNS_MODE]		= { .type = NLA_U8, },
701 	[L2TP_ATTR_USING_IPSEC]		= { .type = NLA_U8, },
702 	[L2TP_ATTR_RECV_TIMEOUT]	= { .type = NLA_MSECS, },
703 	[L2TP_ATTR_FD]			= { .type = NLA_U32, },
704 	[L2TP_ATTR_IP_SADDR]		= { .type = NLA_U32, },
705 	[L2TP_ATTR_IP_DADDR]		= { .type = NLA_U32, },
706 	[L2TP_ATTR_UDP_SPORT]		= { .type = NLA_U16, },
707 	[L2TP_ATTR_UDP_DPORT]		= { .type = NLA_U16, },
708 	[L2TP_ATTR_MTU]			= { .type = NLA_U16, },
709 	[L2TP_ATTR_MRU]			= { .type = NLA_U16, },
710 	[L2TP_ATTR_STATS]		= { .type = NLA_NESTED, },
711 	[L2TP_ATTR_IFNAME] = {
712 		.type = NLA_NUL_STRING,
713 		.len = IFNAMSIZ - 1,
714 	},
715 	[L2TP_ATTR_COOKIE] = {
716 		.type = NLA_BINARY,
717 		.len = 8,
718 	},
719 	[L2TP_ATTR_PEER_COOKIE] = {
720 		.type = NLA_BINARY,
721 		.len = 8,
722 	},
723 };
724 
725 static struct genl_ops l2tp_nl_ops[] = {
726 	{
727 		.cmd = L2TP_CMD_NOOP,
728 		.doit = l2tp_nl_cmd_noop,
729 		.policy = l2tp_nl_policy,
730 		/* can be retrieved by unprivileged users */
731 	},
732 	{
733 		.cmd = L2TP_CMD_TUNNEL_CREATE,
734 		.doit = l2tp_nl_cmd_tunnel_create,
735 		.policy = l2tp_nl_policy,
736 		.flags = GENL_ADMIN_PERM,
737 	},
738 	{
739 		.cmd = L2TP_CMD_TUNNEL_DELETE,
740 		.doit = l2tp_nl_cmd_tunnel_delete,
741 		.policy = l2tp_nl_policy,
742 		.flags = GENL_ADMIN_PERM,
743 	},
744 	{
745 		.cmd = L2TP_CMD_TUNNEL_MODIFY,
746 		.doit = l2tp_nl_cmd_tunnel_modify,
747 		.policy = l2tp_nl_policy,
748 		.flags = GENL_ADMIN_PERM,
749 	},
750 	{
751 		.cmd = L2TP_CMD_TUNNEL_GET,
752 		.doit = l2tp_nl_cmd_tunnel_get,
753 		.dumpit = l2tp_nl_cmd_tunnel_dump,
754 		.policy = l2tp_nl_policy,
755 		.flags = GENL_ADMIN_PERM,
756 	},
757 	{
758 		.cmd = L2TP_CMD_SESSION_CREATE,
759 		.doit = l2tp_nl_cmd_session_create,
760 		.policy = l2tp_nl_policy,
761 		.flags = GENL_ADMIN_PERM,
762 	},
763 	{
764 		.cmd = L2TP_CMD_SESSION_DELETE,
765 		.doit = l2tp_nl_cmd_session_delete,
766 		.policy = l2tp_nl_policy,
767 		.flags = GENL_ADMIN_PERM,
768 	},
769 	{
770 		.cmd = L2TP_CMD_SESSION_MODIFY,
771 		.doit = l2tp_nl_cmd_session_modify,
772 		.policy = l2tp_nl_policy,
773 		.flags = GENL_ADMIN_PERM,
774 	},
775 	{
776 		.cmd = L2TP_CMD_SESSION_GET,
777 		.doit = l2tp_nl_cmd_session_get,
778 		.dumpit = l2tp_nl_cmd_session_dump,
779 		.policy = l2tp_nl_policy,
780 		.flags = GENL_ADMIN_PERM,
781 	},
782 };
783 
l2tp_nl_register_ops(enum l2tp_pwtype pw_type,const struct l2tp_nl_cmd_ops * ops)784 int l2tp_nl_register_ops(enum l2tp_pwtype pw_type, const struct l2tp_nl_cmd_ops *ops)
785 {
786 	int ret;
787 
788 	ret = -EINVAL;
789 	if (pw_type >= __L2TP_PWTYPE_MAX)
790 		goto err;
791 
792 	genl_lock();
793 	ret = -EBUSY;
794 	if (l2tp_nl_cmd_ops[pw_type])
795 		goto out;
796 
797 	l2tp_nl_cmd_ops[pw_type] = ops;
798 	ret = 0;
799 
800 out:
801 	genl_unlock();
802 err:
803 	return ret;
804 }
805 EXPORT_SYMBOL_GPL(l2tp_nl_register_ops);
806 
l2tp_nl_unregister_ops(enum l2tp_pwtype pw_type)807 void l2tp_nl_unregister_ops(enum l2tp_pwtype pw_type)
808 {
809 	if (pw_type < __L2TP_PWTYPE_MAX) {
810 		genl_lock();
811 		l2tp_nl_cmd_ops[pw_type] = NULL;
812 		genl_unlock();
813 	}
814 }
815 EXPORT_SYMBOL_GPL(l2tp_nl_unregister_ops);
816 
l2tp_nl_init(void)817 static int l2tp_nl_init(void)
818 {
819 	int err;
820 
821 	printk(KERN_INFO "L2TP netlink interface\n");
822 	err = genl_register_family_with_ops(&l2tp_nl_family, l2tp_nl_ops,
823 					    ARRAY_SIZE(l2tp_nl_ops));
824 
825 	return err;
826 }
827 
l2tp_nl_cleanup(void)828 static void l2tp_nl_cleanup(void)
829 {
830 	genl_unregister_family(&l2tp_nl_family);
831 }
832 
833 module_init(l2tp_nl_init);
834 module_exit(l2tp_nl_cleanup);
835 
836 MODULE_AUTHOR("James Chapman <jchapman@katalix.com>");
837 MODULE_DESCRIPTION("L2TP netlink");
838 MODULE_LICENSE("GPL");
839 MODULE_VERSION("1.0");
840 MODULE_ALIAS("net-pf-" __stringify(PF_NETLINK) "-proto-" \
841 	     __stringify(NETLINK_GENERIC) "-type-" "l2tp");
842