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 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
18 
19 #include <net/sock.h>
20 #include <net/genetlink.h>
21 #include <net/udp.h>
22 #include <linux/in.h>
23 #include <linux/udp.h>
24 #include <linux/socket.h>
25 #include <linux/module.h>
26 #include <linux/list.h>
27 #include <net/net_namespace.h>
28 
29 #include <linux/l2tp.h>
30 
31 #include "l2tp_core.h"
32 
33 
34 static struct genl_family l2tp_nl_family = {
35 	.id		= GENL_ID_GENERATE,
36 	.name		= L2TP_GENL_NAME,
37 	.version	= L2TP_GENL_VERSION,
38 	.hdrsize	= 0,
39 	.maxattr	= L2TP_ATTR_MAX,
40 	.netnsok	= true,
41 };
42 
43 static const struct genl_multicast_group l2tp_multicast_group[] = {
44 	{
45 		.name = L2TP_GENL_MCGROUP,
46 	},
47 };
48 
49 static int l2tp_nl_tunnel_send(struct sk_buff *skb, u32 portid, u32 seq,
50 			       int flags, struct l2tp_tunnel *tunnel, u8 cmd);
51 static int l2tp_nl_session_send(struct sk_buff *skb, u32 portid, u32 seq,
52 				int flags, struct l2tp_session *session,
53 				u8 cmd);
54 
55 /* Accessed under genl lock */
56 static const struct l2tp_nl_cmd_ops *l2tp_nl_cmd_ops[__L2TP_PWTYPE_MAX];
57 
l2tp_nl_session_find(struct genl_info * info)58 static struct l2tp_session *l2tp_nl_session_find(struct genl_info *info)
59 {
60 	u32 tunnel_id;
61 	u32 session_id;
62 	char *ifname;
63 	struct l2tp_tunnel *tunnel;
64 	struct l2tp_session *session = NULL;
65 	struct net *net = genl_info_net(info);
66 
67 	if (info->attrs[L2TP_ATTR_IFNAME]) {
68 		ifname = nla_data(info->attrs[L2TP_ATTR_IFNAME]);
69 		session = l2tp_session_find_by_ifname(net, ifname);
70 	} else if ((info->attrs[L2TP_ATTR_SESSION_ID]) &&
71 		   (info->attrs[L2TP_ATTR_CONN_ID])) {
72 		tunnel_id = nla_get_u32(info->attrs[L2TP_ATTR_CONN_ID]);
73 		session_id = nla_get_u32(info->attrs[L2TP_ATTR_SESSION_ID]);
74 		tunnel = l2tp_tunnel_find(net, tunnel_id);
75 		if (tunnel)
76 			session = l2tp_session_find(net, tunnel, session_id);
77 	}
78 
79 	return session;
80 }
81 
l2tp_nl_cmd_noop(struct sk_buff * skb,struct genl_info * info)82 static int l2tp_nl_cmd_noop(struct sk_buff *skb, struct genl_info *info)
83 {
84 	struct sk_buff *msg;
85 	void *hdr;
86 	int ret = -ENOBUFS;
87 
88 	msg = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);
89 	if (!msg) {
90 		ret = -ENOMEM;
91 		goto out;
92 	}
93 
94 	hdr = genlmsg_put(msg, info->snd_portid, info->snd_seq,
95 			  &l2tp_nl_family, 0, L2TP_CMD_NOOP);
96 	if (!hdr) {
97 		ret = -EMSGSIZE;
98 		goto err_out;
99 	}
100 
101 	genlmsg_end(msg, hdr);
102 
103 	return genlmsg_unicast(genl_info_net(info), msg, info->snd_portid);
104 
105 err_out:
106 	nlmsg_free(msg);
107 
108 out:
109 	return ret;
110 }
111 
l2tp_tunnel_notify(struct genl_family * family,struct genl_info * info,struct l2tp_tunnel * tunnel,u8 cmd)112 static int l2tp_tunnel_notify(struct genl_family *family,
113 			      struct genl_info *info,
114 			      struct l2tp_tunnel *tunnel,
115 			      u8 cmd)
116 {
117 	struct sk_buff *msg;
118 	int ret;
119 
120 	msg = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);
121 	if (!msg)
122 		return -ENOMEM;
123 
124 	ret = l2tp_nl_tunnel_send(msg, info->snd_portid, info->snd_seq,
125 				  NLM_F_ACK, tunnel, cmd);
126 
127 	if (ret >= 0) {
128 		ret = genlmsg_multicast_allns(family, msg, 0, 0, GFP_ATOMIC);
129 		/* We don't care if no one is listening */
130 		if (ret == -ESRCH)
131 			ret = 0;
132 		return ret;
133 	}
134 
135 	nlmsg_free(msg);
136 
137 	return ret;
138 }
139 
l2tp_session_notify(struct genl_family * family,struct genl_info * info,struct l2tp_session * session,u8 cmd)140 static int l2tp_session_notify(struct genl_family *family,
141 			       struct genl_info *info,
142 			       struct l2tp_session *session,
143 			       u8 cmd)
144 {
145 	struct sk_buff *msg;
146 	int ret;
147 
148 	msg = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);
149 	if (!msg)
150 		return -ENOMEM;
151 
152 	ret = l2tp_nl_session_send(msg, info->snd_portid, info->snd_seq,
153 				   NLM_F_ACK, session, cmd);
154 
155 	if (ret >= 0) {
156 		ret = genlmsg_multicast_allns(family, msg, 0, 0, GFP_ATOMIC);
157 		/* We don't care if no one is listening */
158 		if (ret == -ESRCH)
159 			ret = 0;
160 		return ret;
161 	}
162 
163 	nlmsg_free(msg);
164 
165 	return ret;
166 }
167 
l2tp_nl_cmd_tunnel_create(struct sk_buff * skb,struct genl_info * info)168 static int l2tp_nl_cmd_tunnel_create(struct sk_buff *skb, struct genl_info *info)
169 {
170 	u32 tunnel_id;
171 	u32 peer_tunnel_id;
172 	int proto_version;
173 	int fd;
174 	int ret = 0;
175 	struct l2tp_tunnel_cfg cfg = { 0, };
176 	struct l2tp_tunnel *tunnel;
177 	struct net *net = genl_info_net(info);
178 
179 	if (!info->attrs[L2TP_ATTR_CONN_ID]) {
180 		ret = -EINVAL;
181 		goto out;
182 	}
183 	tunnel_id = nla_get_u32(info->attrs[L2TP_ATTR_CONN_ID]);
184 
185 	if (!info->attrs[L2TP_ATTR_PEER_CONN_ID]) {
186 		ret = -EINVAL;
187 		goto out;
188 	}
189 	peer_tunnel_id = nla_get_u32(info->attrs[L2TP_ATTR_PEER_CONN_ID]);
190 
191 	if (!info->attrs[L2TP_ATTR_PROTO_VERSION]) {
192 		ret = -EINVAL;
193 		goto out;
194 	}
195 	proto_version = nla_get_u8(info->attrs[L2TP_ATTR_PROTO_VERSION]);
196 
197 	if (!info->attrs[L2TP_ATTR_ENCAP_TYPE]) {
198 		ret = -EINVAL;
199 		goto out;
200 	}
201 	cfg.encap = nla_get_u16(info->attrs[L2TP_ATTR_ENCAP_TYPE]);
202 
203 	fd = -1;
204 	if (info->attrs[L2TP_ATTR_FD]) {
205 		fd = nla_get_u32(info->attrs[L2TP_ATTR_FD]);
206 	} else {
207 #if IS_ENABLED(CONFIG_IPV6)
208 		if (info->attrs[L2TP_ATTR_IP6_SADDR] &&
209 		    info->attrs[L2TP_ATTR_IP6_DADDR]) {
210 			cfg.local_ip6 = nla_data(
211 				info->attrs[L2TP_ATTR_IP6_SADDR]);
212 			cfg.peer_ip6 = nla_data(
213 				info->attrs[L2TP_ATTR_IP6_DADDR]);
214 		} else
215 #endif
216 		if (info->attrs[L2TP_ATTR_IP_SADDR] &&
217 		    info->attrs[L2TP_ATTR_IP_DADDR]) {
218 			cfg.local_ip.s_addr = nla_get_in_addr(
219 				info->attrs[L2TP_ATTR_IP_SADDR]);
220 			cfg.peer_ip.s_addr = nla_get_in_addr(
221 				info->attrs[L2TP_ATTR_IP_DADDR]);
222 		} else {
223 			ret = -EINVAL;
224 			goto out;
225 		}
226 		if (info->attrs[L2TP_ATTR_UDP_SPORT])
227 			cfg.local_udp_port = nla_get_u16(info->attrs[L2TP_ATTR_UDP_SPORT]);
228 		if (info->attrs[L2TP_ATTR_UDP_DPORT])
229 			cfg.peer_udp_port = nla_get_u16(info->attrs[L2TP_ATTR_UDP_DPORT]);
230 		if (info->attrs[L2TP_ATTR_UDP_CSUM])
231 			cfg.use_udp_checksums = nla_get_flag(info->attrs[L2TP_ATTR_UDP_CSUM]);
232 
233 #if IS_ENABLED(CONFIG_IPV6)
234 		if (info->attrs[L2TP_ATTR_UDP_ZERO_CSUM6_TX])
235 			cfg.udp6_zero_tx_checksums = nla_get_flag(info->attrs[L2TP_ATTR_UDP_ZERO_CSUM6_TX]);
236 		if (info->attrs[L2TP_ATTR_UDP_ZERO_CSUM6_RX])
237 			cfg.udp6_zero_rx_checksums = nla_get_flag(info->attrs[L2TP_ATTR_UDP_ZERO_CSUM6_RX]);
238 #endif
239 	}
240 
241 	if (info->attrs[L2TP_ATTR_DEBUG])
242 		cfg.debug = nla_get_u32(info->attrs[L2TP_ATTR_DEBUG]);
243 
244 	tunnel = l2tp_tunnel_find(net, tunnel_id);
245 	if (tunnel != NULL) {
246 		ret = -EEXIST;
247 		goto out;
248 	}
249 
250 	ret = -EINVAL;
251 	switch (cfg.encap) {
252 	case L2TP_ENCAPTYPE_UDP:
253 	case L2TP_ENCAPTYPE_IP:
254 		ret = l2tp_tunnel_create(net, fd, proto_version, tunnel_id,
255 					 peer_tunnel_id, &cfg, &tunnel);
256 		break;
257 	}
258 
259 	if (ret >= 0)
260 		ret = l2tp_tunnel_notify(&l2tp_nl_family, info,
261 					 tunnel, L2TP_CMD_TUNNEL_CREATE);
262 out:
263 	return ret;
264 }
265 
l2tp_nl_cmd_tunnel_delete(struct sk_buff * skb,struct genl_info * info)266 static int l2tp_nl_cmd_tunnel_delete(struct sk_buff *skb, struct genl_info *info)
267 {
268 	struct l2tp_tunnel *tunnel;
269 	u32 tunnel_id;
270 	int ret = 0;
271 	struct net *net = genl_info_net(info);
272 
273 	if (!info->attrs[L2TP_ATTR_CONN_ID]) {
274 		ret = -EINVAL;
275 		goto out;
276 	}
277 	tunnel_id = nla_get_u32(info->attrs[L2TP_ATTR_CONN_ID]);
278 
279 	tunnel = l2tp_tunnel_find(net, tunnel_id);
280 	if (tunnel == NULL) {
281 		ret = -ENODEV;
282 		goto out;
283 	}
284 
285 	l2tp_tunnel_notify(&l2tp_nl_family, info,
286 			   tunnel, L2TP_CMD_TUNNEL_DELETE);
287 
288 	(void) l2tp_tunnel_delete(tunnel);
289 
290 out:
291 	return ret;
292 }
293 
l2tp_nl_cmd_tunnel_modify(struct sk_buff * skb,struct genl_info * info)294 static int l2tp_nl_cmd_tunnel_modify(struct sk_buff *skb, struct genl_info *info)
295 {
296 	struct l2tp_tunnel *tunnel;
297 	u32 tunnel_id;
298 	int ret = 0;
299 	struct net *net = genl_info_net(info);
300 
301 	if (!info->attrs[L2TP_ATTR_CONN_ID]) {
302 		ret = -EINVAL;
303 		goto out;
304 	}
305 	tunnel_id = nla_get_u32(info->attrs[L2TP_ATTR_CONN_ID]);
306 
307 	tunnel = l2tp_tunnel_find(net, tunnel_id);
308 	if (tunnel == NULL) {
309 		ret = -ENODEV;
310 		goto out;
311 	}
312 
313 	if (info->attrs[L2TP_ATTR_DEBUG])
314 		tunnel->debug = nla_get_u32(info->attrs[L2TP_ATTR_DEBUG]);
315 
316 	ret = l2tp_tunnel_notify(&l2tp_nl_family, info,
317 				 tunnel, L2TP_CMD_TUNNEL_MODIFY);
318 
319 out:
320 	return ret;
321 }
322 
l2tp_nl_tunnel_send(struct sk_buff * skb,u32 portid,u32 seq,int flags,struct l2tp_tunnel * tunnel,u8 cmd)323 static int l2tp_nl_tunnel_send(struct sk_buff *skb, u32 portid, u32 seq, int flags,
324 			       struct l2tp_tunnel *tunnel, u8 cmd)
325 {
326 	void *hdr;
327 	struct nlattr *nest;
328 	struct sock *sk = NULL;
329 	struct inet_sock *inet;
330 #if IS_ENABLED(CONFIG_IPV6)
331 	struct ipv6_pinfo *np = NULL;
332 #endif
333 
334 	hdr = genlmsg_put(skb, portid, seq, &l2tp_nl_family, flags, cmd);
335 	if (!hdr)
336 		return -EMSGSIZE;
337 
338 	if (nla_put_u8(skb, L2TP_ATTR_PROTO_VERSION, tunnel->version) ||
339 	    nla_put_u32(skb, L2TP_ATTR_CONN_ID, tunnel->tunnel_id) ||
340 	    nla_put_u32(skb, L2TP_ATTR_PEER_CONN_ID, tunnel->peer_tunnel_id) ||
341 	    nla_put_u32(skb, L2TP_ATTR_DEBUG, tunnel->debug) ||
342 	    nla_put_u16(skb, L2TP_ATTR_ENCAP_TYPE, tunnel->encap))
343 		goto nla_put_failure;
344 
345 	nest = nla_nest_start(skb, L2TP_ATTR_STATS);
346 	if (nest == NULL)
347 		goto nla_put_failure;
348 
349 	if (nla_put_u64(skb, L2TP_ATTR_TX_PACKETS,
350 		    atomic_long_read(&tunnel->stats.tx_packets)) ||
351 	    nla_put_u64(skb, L2TP_ATTR_TX_BYTES,
352 		    atomic_long_read(&tunnel->stats.tx_bytes)) ||
353 	    nla_put_u64(skb, L2TP_ATTR_TX_ERRORS,
354 		    atomic_long_read(&tunnel->stats.tx_errors)) ||
355 	    nla_put_u64(skb, L2TP_ATTR_RX_PACKETS,
356 		    atomic_long_read(&tunnel->stats.rx_packets)) ||
357 	    nla_put_u64(skb, L2TP_ATTR_RX_BYTES,
358 		    atomic_long_read(&tunnel->stats.rx_bytes)) ||
359 	    nla_put_u64(skb, L2TP_ATTR_RX_SEQ_DISCARDS,
360 		    atomic_long_read(&tunnel->stats.rx_seq_discards)) ||
361 	    nla_put_u64(skb, L2TP_ATTR_RX_OOS_PACKETS,
362 		    atomic_long_read(&tunnel->stats.rx_oos_packets)) ||
363 	    nla_put_u64(skb, L2TP_ATTR_RX_ERRORS,
364 		    atomic_long_read(&tunnel->stats.rx_errors)))
365 		goto nla_put_failure;
366 	nla_nest_end(skb, nest);
367 
368 	sk = tunnel->sock;
369 	if (!sk)
370 		goto out;
371 
372 #if IS_ENABLED(CONFIG_IPV6)
373 	if (sk->sk_family == AF_INET6)
374 		np = inet6_sk(sk);
375 #endif
376 
377 	inet = inet_sk(sk);
378 
379 	switch (tunnel->encap) {
380 	case L2TP_ENCAPTYPE_UDP:
381 		if (nla_put_u16(skb, L2TP_ATTR_UDP_SPORT, ntohs(inet->inet_sport)) ||
382 		    nla_put_u16(skb, L2TP_ATTR_UDP_DPORT, ntohs(inet->inet_dport)) ||
383 		    nla_put_u8(skb, L2TP_ATTR_UDP_CSUM, !sk->sk_no_check_tx))
384 			goto nla_put_failure;
385 		/* NOBREAK */
386 	case L2TP_ENCAPTYPE_IP:
387 #if IS_ENABLED(CONFIG_IPV6)
388 		if (np) {
389 			if (nla_put_in6_addr(skb, L2TP_ATTR_IP6_SADDR,
390 					     &np->saddr) ||
391 			    nla_put_in6_addr(skb, L2TP_ATTR_IP6_DADDR,
392 					     &sk->sk_v6_daddr))
393 				goto nla_put_failure;
394 		} else
395 #endif
396 		if (nla_put_in_addr(skb, L2TP_ATTR_IP_SADDR,
397 				    inet->inet_saddr) ||
398 		    nla_put_in_addr(skb, L2TP_ATTR_IP_DADDR,
399 				    inet->inet_daddr))
400 			goto nla_put_failure;
401 		break;
402 	}
403 
404 out:
405 	genlmsg_end(skb, hdr);
406 	return 0;
407 
408 nla_put_failure:
409 	genlmsg_cancel(skb, hdr);
410 	return -1;
411 }
412 
l2tp_nl_cmd_tunnel_get(struct sk_buff * skb,struct genl_info * info)413 static int l2tp_nl_cmd_tunnel_get(struct sk_buff *skb, struct genl_info *info)
414 {
415 	struct l2tp_tunnel *tunnel;
416 	struct sk_buff *msg;
417 	u32 tunnel_id;
418 	int ret = -ENOBUFS;
419 	struct net *net = genl_info_net(info);
420 
421 	if (!info->attrs[L2TP_ATTR_CONN_ID]) {
422 		ret = -EINVAL;
423 		goto out;
424 	}
425 
426 	tunnel_id = nla_get_u32(info->attrs[L2TP_ATTR_CONN_ID]);
427 
428 	tunnel = l2tp_tunnel_find(net, tunnel_id);
429 	if (tunnel == NULL) {
430 		ret = -ENODEV;
431 		goto out;
432 	}
433 
434 	msg = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);
435 	if (!msg) {
436 		ret = -ENOMEM;
437 		goto out;
438 	}
439 
440 	ret = l2tp_nl_tunnel_send(msg, info->snd_portid, info->snd_seq,
441 				  NLM_F_ACK, tunnel, L2TP_CMD_TUNNEL_GET);
442 	if (ret < 0)
443 		goto err_out;
444 
445 	return genlmsg_unicast(net, msg, info->snd_portid);
446 
447 err_out:
448 	nlmsg_free(msg);
449 
450 out:
451 	return ret;
452 }
453 
l2tp_nl_cmd_tunnel_dump(struct sk_buff * skb,struct netlink_callback * cb)454 static int l2tp_nl_cmd_tunnel_dump(struct sk_buff *skb, struct netlink_callback *cb)
455 {
456 	int ti = cb->args[0];
457 	struct l2tp_tunnel *tunnel;
458 	struct net *net = sock_net(skb->sk);
459 
460 	for (;;) {
461 		tunnel = l2tp_tunnel_find_nth(net, ti);
462 		if (tunnel == NULL)
463 			goto out;
464 
465 		if (l2tp_nl_tunnel_send(skb, NETLINK_CB(cb->skb).portid,
466 					cb->nlh->nlmsg_seq, NLM_F_MULTI,
467 					tunnel, L2TP_CMD_TUNNEL_GET) < 0)
468 			goto out;
469 
470 		ti++;
471 	}
472 
473 out:
474 	cb->args[0] = ti;
475 
476 	return skb->len;
477 }
478 
l2tp_nl_cmd_session_create(struct sk_buff * skb,struct genl_info * info)479 static int l2tp_nl_cmd_session_create(struct sk_buff *skb, struct genl_info *info)
480 {
481 	u32 tunnel_id = 0;
482 	u32 session_id;
483 	u32 peer_session_id;
484 	int ret = 0;
485 	struct l2tp_tunnel *tunnel;
486 	struct l2tp_session *session;
487 	struct l2tp_session_cfg cfg = { 0, };
488 	struct net *net = genl_info_net(info);
489 
490 	if (!info->attrs[L2TP_ATTR_CONN_ID]) {
491 		ret = -EINVAL;
492 		goto out;
493 	}
494 	tunnel_id = nla_get_u32(info->attrs[L2TP_ATTR_CONN_ID]);
495 	tunnel = l2tp_tunnel_find(net, tunnel_id);
496 	if (!tunnel) {
497 		ret = -ENODEV;
498 		goto out;
499 	}
500 
501 	if (!info->attrs[L2TP_ATTR_SESSION_ID]) {
502 		ret = -EINVAL;
503 		goto out;
504 	}
505 	session_id = nla_get_u32(info->attrs[L2TP_ATTR_SESSION_ID]);
506 	session = l2tp_session_find(net, tunnel, session_id);
507 	if (session) {
508 		ret = -EEXIST;
509 		goto out;
510 	}
511 
512 	if (!info->attrs[L2TP_ATTR_PEER_SESSION_ID]) {
513 		ret = -EINVAL;
514 		goto out;
515 	}
516 	peer_session_id = nla_get_u32(info->attrs[L2TP_ATTR_PEER_SESSION_ID]);
517 
518 	if (!info->attrs[L2TP_ATTR_PW_TYPE]) {
519 		ret = -EINVAL;
520 		goto out;
521 	}
522 	cfg.pw_type = nla_get_u16(info->attrs[L2TP_ATTR_PW_TYPE]);
523 	if (cfg.pw_type >= __L2TP_PWTYPE_MAX) {
524 		ret = -EINVAL;
525 		goto out;
526 	}
527 
528 	if (tunnel->version > 2) {
529 		if (info->attrs[L2TP_ATTR_OFFSET])
530 			cfg.offset = nla_get_u16(info->attrs[L2TP_ATTR_OFFSET]);
531 
532 		if (info->attrs[L2TP_ATTR_DATA_SEQ])
533 			cfg.data_seq = nla_get_u8(info->attrs[L2TP_ATTR_DATA_SEQ]);
534 
535 		cfg.l2specific_type = L2TP_L2SPECTYPE_DEFAULT;
536 		if (info->attrs[L2TP_ATTR_L2SPEC_TYPE])
537 			cfg.l2specific_type = nla_get_u8(info->attrs[L2TP_ATTR_L2SPEC_TYPE]);
538 
539 		cfg.l2specific_len = 4;
540 		if (info->attrs[L2TP_ATTR_L2SPEC_LEN])
541 			cfg.l2specific_len = nla_get_u8(info->attrs[L2TP_ATTR_L2SPEC_LEN]);
542 
543 		if (info->attrs[L2TP_ATTR_COOKIE]) {
544 			u16 len = nla_len(info->attrs[L2TP_ATTR_COOKIE]);
545 			if (len > 8) {
546 				ret = -EINVAL;
547 				goto out;
548 			}
549 			cfg.cookie_len = len;
550 			memcpy(&cfg.cookie[0], nla_data(info->attrs[L2TP_ATTR_COOKIE]), len);
551 		}
552 		if (info->attrs[L2TP_ATTR_PEER_COOKIE]) {
553 			u16 len = nla_len(info->attrs[L2TP_ATTR_PEER_COOKIE]);
554 			if (len > 8) {
555 				ret = -EINVAL;
556 				goto out;
557 			}
558 			cfg.peer_cookie_len = len;
559 			memcpy(&cfg.peer_cookie[0], nla_data(info->attrs[L2TP_ATTR_PEER_COOKIE]), len);
560 		}
561 		if (info->attrs[L2TP_ATTR_IFNAME])
562 			cfg.ifname = nla_data(info->attrs[L2TP_ATTR_IFNAME]);
563 
564 		if (info->attrs[L2TP_ATTR_VLAN_ID])
565 			cfg.vlan_id = nla_get_u16(info->attrs[L2TP_ATTR_VLAN_ID]);
566 	}
567 
568 	if (info->attrs[L2TP_ATTR_DEBUG])
569 		cfg.debug = nla_get_u32(info->attrs[L2TP_ATTR_DEBUG]);
570 
571 	if (info->attrs[L2TP_ATTR_RECV_SEQ])
572 		cfg.recv_seq = nla_get_u8(info->attrs[L2TP_ATTR_RECV_SEQ]);
573 
574 	if (info->attrs[L2TP_ATTR_SEND_SEQ])
575 		cfg.send_seq = nla_get_u8(info->attrs[L2TP_ATTR_SEND_SEQ]);
576 
577 	if (info->attrs[L2TP_ATTR_LNS_MODE])
578 		cfg.lns_mode = nla_get_u8(info->attrs[L2TP_ATTR_LNS_MODE]);
579 
580 	if (info->attrs[L2TP_ATTR_RECV_TIMEOUT])
581 		cfg.reorder_timeout = nla_get_msecs(info->attrs[L2TP_ATTR_RECV_TIMEOUT]);
582 
583 	if (info->attrs[L2TP_ATTR_MTU])
584 		cfg.mtu = nla_get_u16(info->attrs[L2TP_ATTR_MTU]);
585 
586 	if (info->attrs[L2TP_ATTR_MRU])
587 		cfg.mru = nla_get_u16(info->attrs[L2TP_ATTR_MRU]);
588 
589 	if ((l2tp_nl_cmd_ops[cfg.pw_type] == NULL) ||
590 	    (l2tp_nl_cmd_ops[cfg.pw_type]->session_create == NULL)) {
591 		ret = -EPROTONOSUPPORT;
592 		goto out;
593 	}
594 
595 	/* Check that pseudowire-specific params are present */
596 	switch (cfg.pw_type) {
597 	case L2TP_PWTYPE_NONE:
598 		break;
599 	case L2TP_PWTYPE_ETH_VLAN:
600 		if (!info->attrs[L2TP_ATTR_VLAN_ID]) {
601 			ret = -EINVAL;
602 			goto out;
603 		}
604 		break;
605 	case L2TP_PWTYPE_ETH:
606 		break;
607 	case L2TP_PWTYPE_PPP:
608 	case L2TP_PWTYPE_PPP_AC:
609 		break;
610 	case L2TP_PWTYPE_IP:
611 	default:
612 		ret = -EPROTONOSUPPORT;
613 		break;
614 	}
615 
616 	ret = -EPROTONOSUPPORT;
617 	if (l2tp_nl_cmd_ops[cfg.pw_type]->session_create)
618 		ret = (*l2tp_nl_cmd_ops[cfg.pw_type]->session_create)(net, tunnel_id,
619 			session_id, peer_session_id, &cfg);
620 
621 	if (ret >= 0) {
622 		session = l2tp_session_find(net, tunnel, session_id);
623 		if (session)
624 			ret = l2tp_session_notify(&l2tp_nl_family, info, session,
625 						  L2TP_CMD_SESSION_CREATE);
626 	}
627 
628 out:
629 	return ret;
630 }
631 
l2tp_nl_cmd_session_delete(struct sk_buff * skb,struct genl_info * info)632 static int l2tp_nl_cmd_session_delete(struct sk_buff *skb, struct genl_info *info)
633 {
634 	int ret = 0;
635 	struct l2tp_session *session;
636 	u16 pw_type;
637 
638 	session = l2tp_nl_session_find(info);
639 	if (session == NULL) {
640 		ret = -ENODEV;
641 		goto out;
642 	}
643 
644 	l2tp_session_notify(&l2tp_nl_family, info,
645 			    session, L2TP_CMD_SESSION_DELETE);
646 
647 	pw_type = session->pwtype;
648 	if (pw_type < __L2TP_PWTYPE_MAX)
649 		if (l2tp_nl_cmd_ops[pw_type] && l2tp_nl_cmd_ops[pw_type]->session_delete)
650 			ret = (*l2tp_nl_cmd_ops[pw_type]->session_delete)(session);
651 
652 out:
653 	return ret;
654 }
655 
l2tp_nl_cmd_session_modify(struct sk_buff * skb,struct genl_info * info)656 static int l2tp_nl_cmd_session_modify(struct sk_buff *skb, struct genl_info *info)
657 {
658 	int ret = 0;
659 	struct l2tp_session *session;
660 
661 	session = l2tp_nl_session_find(info);
662 	if (session == NULL) {
663 		ret = -ENODEV;
664 		goto out;
665 	}
666 
667 	if (info->attrs[L2TP_ATTR_DEBUG])
668 		session->debug = nla_get_u32(info->attrs[L2TP_ATTR_DEBUG]);
669 
670 	if (info->attrs[L2TP_ATTR_DATA_SEQ])
671 		session->data_seq = nla_get_u8(info->attrs[L2TP_ATTR_DATA_SEQ]);
672 
673 	if (info->attrs[L2TP_ATTR_RECV_SEQ])
674 		session->recv_seq = nla_get_u8(info->attrs[L2TP_ATTR_RECV_SEQ]);
675 
676 	if (info->attrs[L2TP_ATTR_SEND_SEQ]) {
677 		session->send_seq = nla_get_u8(info->attrs[L2TP_ATTR_SEND_SEQ]);
678 		l2tp_session_set_header_len(session, session->tunnel->version);
679 	}
680 
681 	if (info->attrs[L2TP_ATTR_LNS_MODE])
682 		session->lns_mode = nla_get_u8(info->attrs[L2TP_ATTR_LNS_MODE]);
683 
684 	if (info->attrs[L2TP_ATTR_RECV_TIMEOUT])
685 		session->reorder_timeout = nla_get_msecs(info->attrs[L2TP_ATTR_RECV_TIMEOUT]);
686 
687 	if (info->attrs[L2TP_ATTR_MTU])
688 		session->mtu = nla_get_u16(info->attrs[L2TP_ATTR_MTU]);
689 
690 	if (info->attrs[L2TP_ATTR_MRU])
691 		session->mru = nla_get_u16(info->attrs[L2TP_ATTR_MRU]);
692 
693 	ret = l2tp_session_notify(&l2tp_nl_family, info,
694 				  session, L2TP_CMD_SESSION_MODIFY);
695 
696 out:
697 	return ret;
698 }
699 
l2tp_nl_session_send(struct sk_buff * skb,u32 portid,u32 seq,int flags,struct l2tp_session * session,u8 cmd)700 static int l2tp_nl_session_send(struct sk_buff *skb, u32 portid, u32 seq, int flags,
701 				struct l2tp_session *session, u8 cmd)
702 {
703 	void *hdr;
704 	struct nlattr *nest;
705 	struct l2tp_tunnel *tunnel = session->tunnel;
706 	struct sock *sk = NULL;
707 
708 	sk = tunnel->sock;
709 
710 	hdr = genlmsg_put(skb, portid, seq, &l2tp_nl_family, flags, cmd);
711 	if (!hdr)
712 		return -EMSGSIZE;
713 
714 	if (nla_put_u32(skb, L2TP_ATTR_CONN_ID, tunnel->tunnel_id) ||
715 	    nla_put_u32(skb, L2TP_ATTR_SESSION_ID, session->session_id) ||
716 	    nla_put_u32(skb, L2TP_ATTR_PEER_CONN_ID, tunnel->peer_tunnel_id) ||
717 	    nla_put_u32(skb, L2TP_ATTR_PEER_SESSION_ID,
718 			session->peer_session_id) ||
719 	    nla_put_u32(skb, L2TP_ATTR_DEBUG, session->debug) ||
720 	    nla_put_u16(skb, L2TP_ATTR_PW_TYPE, session->pwtype) ||
721 	    nla_put_u16(skb, L2TP_ATTR_MTU, session->mtu) ||
722 	    (session->mru &&
723 	     nla_put_u16(skb, L2TP_ATTR_MRU, session->mru)))
724 		goto nla_put_failure;
725 
726 	if ((session->ifname[0] &&
727 	     nla_put_string(skb, L2TP_ATTR_IFNAME, session->ifname)) ||
728 	    (session->cookie_len &&
729 	     nla_put(skb, L2TP_ATTR_COOKIE, session->cookie_len,
730 		     &session->cookie[0])) ||
731 	    (session->peer_cookie_len &&
732 	     nla_put(skb, L2TP_ATTR_PEER_COOKIE, session->peer_cookie_len,
733 		     &session->peer_cookie[0])) ||
734 	    nla_put_u8(skb, L2TP_ATTR_RECV_SEQ, session->recv_seq) ||
735 	    nla_put_u8(skb, L2TP_ATTR_SEND_SEQ, session->send_seq) ||
736 	    nla_put_u8(skb, L2TP_ATTR_LNS_MODE, session->lns_mode) ||
737 #ifdef CONFIG_XFRM
738 	    (((sk) && (sk->sk_policy[0] || sk->sk_policy[1])) &&
739 	     nla_put_u8(skb, L2TP_ATTR_USING_IPSEC, 1)) ||
740 #endif
741 	    (session->reorder_timeout &&
742 	     nla_put_msecs(skb, L2TP_ATTR_RECV_TIMEOUT, session->reorder_timeout)))
743 		goto nla_put_failure;
744 
745 	nest = nla_nest_start(skb, L2TP_ATTR_STATS);
746 	if (nest == NULL)
747 		goto nla_put_failure;
748 
749 	if (nla_put_u64(skb, L2TP_ATTR_TX_PACKETS,
750 		atomic_long_read(&session->stats.tx_packets)) ||
751 	    nla_put_u64(skb, L2TP_ATTR_TX_BYTES,
752 		atomic_long_read(&session->stats.tx_bytes)) ||
753 	    nla_put_u64(skb, L2TP_ATTR_TX_ERRORS,
754 		atomic_long_read(&session->stats.tx_errors)) ||
755 	    nla_put_u64(skb, L2TP_ATTR_RX_PACKETS,
756 		atomic_long_read(&session->stats.rx_packets)) ||
757 	    nla_put_u64(skb, L2TP_ATTR_RX_BYTES,
758 		atomic_long_read(&session->stats.rx_bytes)) ||
759 	    nla_put_u64(skb, L2TP_ATTR_RX_SEQ_DISCARDS,
760 		atomic_long_read(&session->stats.rx_seq_discards)) ||
761 	    nla_put_u64(skb, L2TP_ATTR_RX_OOS_PACKETS,
762 		atomic_long_read(&session->stats.rx_oos_packets)) ||
763 	    nla_put_u64(skb, L2TP_ATTR_RX_ERRORS,
764 		atomic_long_read(&session->stats.rx_errors)))
765 		goto nla_put_failure;
766 	nla_nest_end(skb, nest);
767 
768 	genlmsg_end(skb, hdr);
769 	return 0;
770 
771  nla_put_failure:
772 	genlmsg_cancel(skb, hdr);
773 	return -1;
774 }
775 
l2tp_nl_cmd_session_get(struct sk_buff * skb,struct genl_info * info)776 static int l2tp_nl_cmd_session_get(struct sk_buff *skb, struct genl_info *info)
777 {
778 	struct l2tp_session *session;
779 	struct sk_buff *msg;
780 	int ret;
781 
782 	session = l2tp_nl_session_find(info);
783 	if (session == NULL) {
784 		ret = -ENODEV;
785 		goto out;
786 	}
787 
788 	msg = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);
789 	if (!msg) {
790 		ret = -ENOMEM;
791 		goto out;
792 	}
793 
794 	ret = l2tp_nl_session_send(msg, info->snd_portid, info->snd_seq,
795 				   0, session, L2TP_CMD_SESSION_GET);
796 	if (ret < 0)
797 		goto err_out;
798 
799 	return genlmsg_unicast(genl_info_net(info), msg, info->snd_portid);
800 
801 err_out:
802 	nlmsg_free(msg);
803 
804 out:
805 	return ret;
806 }
807 
l2tp_nl_cmd_session_dump(struct sk_buff * skb,struct netlink_callback * cb)808 static int l2tp_nl_cmd_session_dump(struct sk_buff *skb, struct netlink_callback *cb)
809 {
810 	struct net *net = sock_net(skb->sk);
811 	struct l2tp_session *session;
812 	struct l2tp_tunnel *tunnel = NULL;
813 	int ti = cb->args[0];
814 	int si = cb->args[1];
815 
816 	for (;;) {
817 		if (tunnel == NULL) {
818 			tunnel = l2tp_tunnel_find_nth(net, ti);
819 			if (tunnel == NULL)
820 				goto out;
821 		}
822 
823 		session = l2tp_session_find_nth(tunnel, si);
824 		if (session == NULL) {
825 			ti++;
826 			tunnel = NULL;
827 			si = 0;
828 			continue;
829 		}
830 
831 		if (l2tp_nl_session_send(skb, NETLINK_CB(cb->skb).portid,
832 					 cb->nlh->nlmsg_seq, NLM_F_MULTI,
833 					 session, L2TP_CMD_SESSION_GET) < 0)
834 			break;
835 
836 		si++;
837 	}
838 
839 out:
840 	cb->args[0] = ti;
841 	cb->args[1] = si;
842 
843 	return skb->len;
844 }
845 
846 static struct nla_policy l2tp_nl_policy[L2TP_ATTR_MAX + 1] = {
847 	[L2TP_ATTR_NONE]		= { .type = NLA_UNSPEC, },
848 	[L2TP_ATTR_PW_TYPE]		= { .type = NLA_U16, },
849 	[L2TP_ATTR_ENCAP_TYPE]		= { .type = NLA_U16, },
850 	[L2TP_ATTR_OFFSET]		= { .type = NLA_U16, },
851 	[L2TP_ATTR_DATA_SEQ]		= { .type = NLA_U8, },
852 	[L2TP_ATTR_L2SPEC_TYPE]		= { .type = NLA_U8, },
853 	[L2TP_ATTR_L2SPEC_LEN]		= { .type = NLA_U8, },
854 	[L2TP_ATTR_PROTO_VERSION]	= { .type = NLA_U8, },
855 	[L2TP_ATTR_CONN_ID]		= { .type = NLA_U32, },
856 	[L2TP_ATTR_PEER_CONN_ID]	= { .type = NLA_U32, },
857 	[L2TP_ATTR_SESSION_ID]		= { .type = NLA_U32, },
858 	[L2TP_ATTR_PEER_SESSION_ID]	= { .type = NLA_U32, },
859 	[L2TP_ATTR_UDP_CSUM]		= { .type = NLA_U8, },
860 	[L2TP_ATTR_VLAN_ID]		= { .type = NLA_U16, },
861 	[L2TP_ATTR_DEBUG]		= { .type = NLA_U32, },
862 	[L2TP_ATTR_RECV_SEQ]		= { .type = NLA_U8, },
863 	[L2TP_ATTR_SEND_SEQ]		= { .type = NLA_U8, },
864 	[L2TP_ATTR_LNS_MODE]		= { .type = NLA_U8, },
865 	[L2TP_ATTR_USING_IPSEC]		= { .type = NLA_U8, },
866 	[L2TP_ATTR_RECV_TIMEOUT]	= { .type = NLA_MSECS, },
867 	[L2TP_ATTR_FD]			= { .type = NLA_U32, },
868 	[L2TP_ATTR_IP_SADDR]		= { .type = NLA_U32, },
869 	[L2TP_ATTR_IP_DADDR]		= { .type = NLA_U32, },
870 	[L2TP_ATTR_UDP_SPORT]		= { .type = NLA_U16, },
871 	[L2TP_ATTR_UDP_DPORT]		= { .type = NLA_U16, },
872 	[L2TP_ATTR_MTU]			= { .type = NLA_U16, },
873 	[L2TP_ATTR_MRU]			= { .type = NLA_U16, },
874 	[L2TP_ATTR_STATS]		= { .type = NLA_NESTED, },
875 	[L2TP_ATTR_IP6_SADDR] = {
876 		.type = NLA_BINARY,
877 		.len = sizeof(struct in6_addr),
878 	},
879 	[L2TP_ATTR_IP6_DADDR] = {
880 		.type = NLA_BINARY,
881 		.len = sizeof(struct in6_addr),
882 	},
883 	[L2TP_ATTR_IFNAME] = {
884 		.type = NLA_NUL_STRING,
885 		.len = IFNAMSIZ - 1,
886 	},
887 	[L2TP_ATTR_COOKIE] = {
888 		.type = NLA_BINARY,
889 		.len = 8,
890 	},
891 	[L2TP_ATTR_PEER_COOKIE] = {
892 		.type = NLA_BINARY,
893 		.len = 8,
894 	},
895 };
896 
897 static const struct genl_ops l2tp_nl_ops[] = {
898 	{
899 		.cmd = L2TP_CMD_NOOP,
900 		.doit = l2tp_nl_cmd_noop,
901 		.policy = l2tp_nl_policy,
902 		/* can be retrieved by unprivileged users */
903 	},
904 	{
905 		.cmd = L2TP_CMD_TUNNEL_CREATE,
906 		.doit = l2tp_nl_cmd_tunnel_create,
907 		.policy = l2tp_nl_policy,
908 		.flags = GENL_ADMIN_PERM,
909 	},
910 	{
911 		.cmd = L2TP_CMD_TUNNEL_DELETE,
912 		.doit = l2tp_nl_cmd_tunnel_delete,
913 		.policy = l2tp_nl_policy,
914 		.flags = GENL_ADMIN_PERM,
915 	},
916 	{
917 		.cmd = L2TP_CMD_TUNNEL_MODIFY,
918 		.doit = l2tp_nl_cmd_tunnel_modify,
919 		.policy = l2tp_nl_policy,
920 		.flags = GENL_ADMIN_PERM,
921 	},
922 	{
923 		.cmd = L2TP_CMD_TUNNEL_GET,
924 		.doit = l2tp_nl_cmd_tunnel_get,
925 		.dumpit = l2tp_nl_cmd_tunnel_dump,
926 		.policy = l2tp_nl_policy,
927 		.flags = GENL_ADMIN_PERM,
928 	},
929 	{
930 		.cmd = L2TP_CMD_SESSION_CREATE,
931 		.doit = l2tp_nl_cmd_session_create,
932 		.policy = l2tp_nl_policy,
933 		.flags = GENL_ADMIN_PERM,
934 	},
935 	{
936 		.cmd = L2TP_CMD_SESSION_DELETE,
937 		.doit = l2tp_nl_cmd_session_delete,
938 		.policy = l2tp_nl_policy,
939 		.flags = GENL_ADMIN_PERM,
940 	},
941 	{
942 		.cmd = L2TP_CMD_SESSION_MODIFY,
943 		.doit = l2tp_nl_cmd_session_modify,
944 		.policy = l2tp_nl_policy,
945 		.flags = GENL_ADMIN_PERM,
946 	},
947 	{
948 		.cmd = L2TP_CMD_SESSION_GET,
949 		.doit = l2tp_nl_cmd_session_get,
950 		.dumpit = l2tp_nl_cmd_session_dump,
951 		.policy = l2tp_nl_policy,
952 		.flags = GENL_ADMIN_PERM,
953 	},
954 };
955 
l2tp_nl_register_ops(enum l2tp_pwtype pw_type,const struct l2tp_nl_cmd_ops * ops)956 int l2tp_nl_register_ops(enum l2tp_pwtype pw_type, const struct l2tp_nl_cmd_ops *ops)
957 {
958 	int ret;
959 
960 	ret = -EINVAL;
961 	if (pw_type >= __L2TP_PWTYPE_MAX)
962 		goto err;
963 
964 	genl_lock();
965 	ret = -EBUSY;
966 	if (l2tp_nl_cmd_ops[pw_type])
967 		goto out;
968 
969 	l2tp_nl_cmd_ops[pw_type] = ops;
970 	ret = 0;
971 
972 out:
973 	genl_unlock();
974 err:
975 	return ret;
976 }
977 EXPORT_SYMBOL_GPL(l2tp_nl_register_ops);
978 
l2tp_nl_unregister_ops(enum l2tp_pwtype pw_type)979 void l2tp_nl_unregister_ops(enum l2tp_pwtype pw_type)
980 {
981 	if (pw_type < __L2TP_PWTYPE_MAX) {
982 		genl_lock();
983 		l2tp_nl_cmd_ops[pw_type] = NULL;
984 		genl_unlock();
985 	}
986 }
987 EXPORT_SYMBOL_GPL(l2tp_nl_unregister_ops);
988 
l2tp_nl_init(void)989 static int l2tp_nl_init(void)
990 {
991 	pr_info("L2TP netlink interface\n");
992 	return genl_register_family_with_ops_groups(&l2tp_nl_family,
993 						    l2tp_nl_ops,
994 						    l2tp_multicast_group);
995 }
996 
l2tp_nl_cleanup(void)997 static void l2tp_nl_cleanup(void)
998 {
999 	genl_unregister_family(&l2tp_nl_family);
1000 }
1001 
1002 module_init(l2tp_nl_init);
1003 module_exit(l2tp_nl_cleanup);
1004 
1005 MODULE_AUTHOR("James Chapman <jchapman@katalix.com>");
1006 MODULE_DESCRIPTION("L2TP netlink");
1007 MODULE_LICENSE("GPL");
1008 MODULE_VERSION("1.0");
1009 MODULE_ALIAS_GENL_FAMILY("l2tp");
1010