xref: /openbmc/linux/net/l2tp/l2tp_netlink.c (revision 0edbfea5) 
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 
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 
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 
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 
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 
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 
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 
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 
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_64bit(skb, L2TP_ATTR_TX_PACKETS,
350 			      atomic_long_read(&tunnel->stats.tx_packets),
351 			      L2TP_ATTR_STATS_PAD) ||
352 	    nla_put_u64_64bit(skb, L2TP_ATTR_TX_BYTES,
353 			      atomic_long_read(&tunnel->stats.tx_bytes),
354 			      L2TP_ATTR_STATS_PAD) ||
355 	    nla_put_u64_64bit(skb, L2TP_ATTR_TX_ERRORS,
356 			      atomic_long_read(&tunnel->stats.tx_errors),
357 			      L2TP_ATTR_STATS_PAD) ||
358 	    nla_put_u64_64bit(skb, L2TP_ATTR_RX_PACKETS,
359 			      atomic_long_read(&tunnel->stats.rx_packets),
360 			      L2TP_ATTR_STATS_PAD) ||
361 	    nla_put_u64_64bit(skb, L2TP_ATTR_RX_BYTES,
362 			      atomic_long_read(&tunnel->stats.rx_bytes),
363 			      L2TP_ATTR_STATS_PAD) ||
364 	    nla_put_u64_64bit(skb, L2TP_ATTR_RX_SEQ_DISCARDS,
365 			      atomic_long_read(&tunnel->stats.rx_seq_discards),
366 			      L2TP_ATTR_STATS_PAD) ||
367 	    nla_put_u64_64bit(skb, L2TP_ATTR_RX_OOS_PACKETS,
368 			      atomic_long_read(&tunnel->stats.rx_oos_packets),
369 			      L2TP_ATTR_STATS_PAD) ||
370 	    nla_put_u64_64bit(skb, L2TP_ATTR_RX_ERRORS,
371 			      atomic_long_read(&tunnel->stats.rx_errors),
372 			      L2TP_ATTR_STATS_PAD))
373 		goto nla_put_failure;
374 	nla_nest_end(skb, nest);
375 
376 	sk = tunnel->sock;
377 	if (!sk)
378 		goto out;
379 
380 #if IS_ENABLED(CONFIG_IPV6)
381 	if (sk->sk_family == AF_INET6)
382 		np = inet6_sk(sk);
383 #endif
384 
385 	inet = inet_sk(sk);
386 
387 	switch (tunnel->encap) {
388 	case L2TP_ENCAPTYPE_UDP:
389 		if (nla_put_u16(skb, L2TP_ATTR_UDP_SPORT, ntohs(inet->inet_sport)) ||
390 		    nla_put_u16(skb, L2TP_ATTR_UDP_DPORT, ntohs(inet->inet_dport)) ||
391 		    nla_put_u8(skb, L2TP_ATTR_UDP_CSUM, !sk->sk_no_check_tx))
392 			goto nla_put_failure;
393 		/* NOBREAK */
394 	case L2TP_ENCAPTYPE_IP:
395 #if IS_ENABLED(CONFIG_IPV6)
396 		if (np) {
397 			if (nla_put_in6_addr(skb, L2TP_ATTR_IP6_SADDR,
398 					     &np->saddr) ||
399 			    nla_put_in6_addr(skb, L2TP_ATTR_IP6_DADDR,
400 					     &sk->sk_v6_daddr))
401 				goto nla_put_failure;
402 		} else
403 #endif
404 		if (nla_put_in_addr(skb, L2TP_ATTR_IP_SADDR,
405 				    inet->inet_saddr) ||
406 		    nla_put_in_addr(skb, L2TP_ATTR_IP_DADDR,
407 				    inet->inet_daddr))
408 			goto nla_put_failure;
409 		break;
410 	}
411 
412 out:
413 	genlmsg_end(skb, hdr);
414 	return 0;
415 
416 nla_put_failure:
417 	genlmsg_cancel(skb, hdr);
418 	return -1;
419 }
420 
421 static int l2tp_nl_cmd_tunnel_get(struct sk_buff *skb, struct genl_info *info)
422 {
423 	struct l2tp_tunnel *tunnel;
424 	struct sk_buff *msg;
425 	u32 tunnel_id;
426 	int ret = -ENOBUFS;
427 	struct net *net = genl_info_net(info);
428 
429 	if (!info->attrs[L2TP_ATTR_CONN_ID]) {
430 		ret = -EINVAL;
431 		goto out;
432 	}
433 
434 	tunnel_id = nla_get_u32(info->attrs[L2TP_ATTR_CONN_ID]);
435 
436 	tunnel = l2tp_tunnel_find(net, tunnel_id);
437 	if (tunnel == NULL) {
438 		ret = -ENODEV;
439 		goto out;
440 	}
441 
442 	msg = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);
443 	if (!msg) {
444 		ret = -ENOMEM;
445 		goto out;
446 	}
447 
448 	ret = l2tp_nl_tunnel_send(msg, info->snd_portid, info->snd_seq,
449 				  NLM_F_ACK, tunnel, L2TP_CMD_TUNNEL_GET);
450 	if (ret < 0)
451 		goto err_out;
452 
453 	return genlmsg_unicast(net, msg, info->snd_portid);
454 
455 err_out:
456 	nlmsg_free(msg);
457 
458 out:
459 	return ret;
460 }
461 
462 static int l2tp_nl_cmd_tunnel_dump(struct sk_buff *skb, struct netlink_callback *cb)
463 {
464 	int ti = cb->args[0];
465 	struct l2tp_tunnel *tunnel;
466 	struct net *net = sock_net(skb->sk);
467 
468 	for (;;) {
469 		tunnel = l2tp_tunnel_find_nth(net, ti);
470 		if (tunnel == NULL)
471 			goto out;
472 
473 		if (l2tp_nl_tunnel_send(skb, NETLINK_CB(cb->skb).portid,
474 					cb->nlh->nlmsg_seq, NLM_F_MULTI,
475 					tunnel, L2TP_CMD_TUNNEL_GET) < 0)
476 			goto out;
477 
478 		ti++;
479 	}
480 
481 out:
482 	cb->args[0] = ti;
483 
484 	return skb->len;
485 }
486 
487 static int l2tp_nl_cmd_session_create(struct sk_buff *skb, struct genl_info *info)
488 {
489 	u32 tunnel_id = 0;
490 	u32 session_id;
491 	u32 peer_session_id;
492 	int ret = 0;
493 	struct l2tp_tunnel *tunnel;
494 	struct l2tp_session *session;
495 	struct l2tp_session_cfg cfg = { 0, };
496 	struct net *net = genl_info_net(info);
497 
498 	if (!info->attrs[L2TP_ATTR_CONN_ID]) {
499 		ret = -EINVAL;
500 		goto out;
501 	}
502 	tunnel_id = nla_get_u32(info->attrs[L2TP_ATTR_CONN_ID]);
503 	tunnel = l2tp_tunnel_find(net, tunnel_id);
504 	if (!tunnel) {
505 		ret = -ENODEV;
506 		goto out;
507 	}
508 
509 	if (!info->attrs[L2TP_ATTR_SESSION_ID]) {
510 		ret = -EINVAL;
511 		goto out;
512 	}
513 	session_id = nla_get_u32(info->attrs[L2TP_ATTR_SESSION_ID]);
514 	session = l2tp_session_find(net, tunnel, session_id);
515 	if (session) {
516 		ret = -EEXIST;
517 		goto out;
518 	}
519 
520 	if (!info->attrs[L2TP_ATTR_PEER_SESSION_ID]) {
521 		ret = -EINVAL;
522 		goto out;
523 	}
524 	peer_session_id = nla_get_u32(info->attrs[L2TP_ATTR_PEER_SESSION_ID]);
525 
526 	if (!info->attrs[L2TP_ATTR_PW_TYPE]) {
527 		ret = -EINVAL;
528 		goto out;
529 	}
530 	cfg.pw_type = nla_get_u16(info->attrs[L2TP_ATTR_PW_TYPE]);
531 	if (cfg.pw_type >= __L2TP_PWTYPE_MAX) {
532 		ret = -EINVAL;
533 		goto out;
534 	}
535 
536 	if (tunnel->version > 2) {
537 		if (info->attrs[L2TP_ATTR_OFFSET])
538 			cfg.offset = nla_get_u16(info->attrs[L2TP_ATTR_OFFSET]);
539 
540 		if (info->attrs[L2TP_ATTR_DATA_SEQ])
541 			cfg.data_seq = nla_get_u8(info->attrs[L2TP_ATTR_DATA_SEQ]);
542 
543 		cfg.l2specific_type = L2TP_L2SPECTYPE_DEFAULT;
544 		if (info->attrs[L2TP_ATTR_L2SPEC_TYPE])
545 			cfg.l2specific_type = nla_get_u8(info->attrs[L2TP_ATTR_L2SPEC_TYPE]);
546 
547 		cfg.l2specific_len = 4;
548 		if (info->attrs[L2TP_ATTR_L2SPEC_LEN])
549 			cfg.l2specific_len = nla_get_u8(info->attrs[L2TP_ATTR_L2SPEC_LEN]);
550 
551 		if (info->attrs[L2TP_ATTR_COOKIE]) {
552 			u16 len = nla_len(info->attrs[L2TP_ATTR_COOKIE]);
553 			if (len > 8) {
554 				ret = -EINVAL;
555 				goto out;
556 			}
557 			cfg.cookie_len = len;
558 			memcpy(&cfg.cookie[0], nla_data(info->attrs[L2TP_ATTR_COOKIE]), len);
559 		}
560 		if (info->attrs[L2TP_ATTR_PEER_COOKIE]) {
561 			u16 len = nla_len(info->attrs[L2TP_ATTR_PEER_COOKIE]);
562 			if (len > 8) {
563 				ret = -EINVAL;
564 				goto out;
565 			}
566 			cfg.peer_cookie_len = len;
567 			memcpy(&cfg.peer_cookie[0], nla_data(info->attrs[L2TP_ATTR_PEER_COOKIE]), len);
568 		}
569 		if (info->attrs[L2TP_ATTR_IFNAME])
570 			cfg.ifname = nla_data(info->attrs[L2TP_ATTR_IFNAME]);
571 
572 		if (info->attrs[L2TP_ATTR_VLAN_ID])
573 			cfg.vlan_id = nla_get_u16(info->attrs[L2TP_ATTR_VLAN_ID]);
574 	}
575 
576 	if (info->attrs[L2TP_ATTR_DEBUG])
577 		cfg.debug = nla_get_u32(info->attrs[L2TP_ATTR_DEBUG]);
578 
579 	if (info->attrs[L2TP_ATTR_RECV_SEQ])
580 		cfg.recv_seq = nla_get_u8(info->attrs[L2TP_ATTR_RECV_SEQ]);
581 
582 	if (info->attrs[L2TP_ATTR_SEND_SEQ])
583 		cfg.send_seq = nla_get_u8(info->attrs[L2TP_ATTR_SEND_SEQ]);
584 
585 	if (info->attrs[L2TP_ATTR_LNS_MODE])
586 		cfg.lns_mode = nla_get_u8(info->attrs[L2TP_ATTR_LNS_MODE]);
587 
588 	if (info->attrs[L2TP_ATTR_RECV_TIMEOUT])
589 		cfg.reorder_timeout = nla_get_msecs(info->attrs[L2TP_ATTR_RECV_TIMEOUT]);
590 
591 	if (info->attrs[L2TP_ATTR_MTU])
592 		cfg.mtu = nla_get_u16(info->attrs[L2TP_ATTR_MTU]);
593 
594 	if (info->attrs[L2TP_ATTR_MRU])
595 		cfg.mru = nla_get_u16(info->attrs[L2TP_ATTR_MRU]);
596 
597 #ifdef CONFIG_MODULES
598 	if (l2tp_nl_cmd_ops[cfg.pw_type] == NULL) {
599 		genl_unlock();
600 		request_module("net-l2tp-type-%u", cfg.pw_type);
601 		genl_lock();
602 	}
603 #endif
604 	if ((l2tp_nl_cmd_ops[cfg.pw_type] == NULL) ||
605 	    (l2tp_nl_cmd_ops[cfg.pw_type]->session_create == NULL)) {
606 		ret = -EPROTONOSUPPORT;
607 		goto out;
608 	}
609 
610 	/* Check that pseudowire-specific params are present */
611 	switch (cfg.pw_type) {
612 	case L2TP_PWTYPE_NONE:
613 		break;
614 	case L2TP_PWTYPE_ETH_VLAN:
615 		if (!info->attrs[L2TP_ATTR_VLAN_ID]) {
616 			ret = -EINVAL;
617 			goto out;
618 		}
619 		break;
620 	case L2TP_PWTYPE_ETH:
621 		break;
622 	case L2TP_PWTYPE_PPP:
623 	case L2TP_PWTYPE_PPP_AC:
624 		break;
625 	case L2TP_PWTYPE_IP:
626 	default:
627 		ret = -EPROTONOSUPPORT;
628 		break;
629 	}
630 
631 	ret = -EPROTONOSUPPORT;
632 	if (l2tp_nl_cmd_ops[cfg.pw_type]->session_create)
633 		ret = (*l2tp_nl_cmd_ops[cfg.pw_type]->session_create)(net, tunnel_id,
634 			session_id, peer_session_id, &cfg);
635 
636 	if (ret >= 0) {
637 		session = l2tp_session_find(net, tunnel, session_id);
638 		if (session)
639 			ret = l2tp_session_notify(&l2tp_nl_family, info, session,
640 						  L2TP_CMD_SESSION_CREATE);
641 	}
642 
643 out:
644 	return ret;
645 }
646 
647 static int l2tp_nl_cmd_session_delete(struct sk_buff *skb, struct genl_info *info)
648 {
649 	int ret = 0;
650 	struct l2tp_session *session;
651 	u16 pw_type;
652 
653 	session = l2tp_nl_session_find(info);
654 	if (session == NULL) {
655 		ret = -ENODEV;
656 		goto out;
657 	}
658 
659 	l2tp_session_notify(&l2tp_nl_family, info,
660 			    session, L2TP_CMD_SESSION_DELETE);
661 
662 	pw_type = session->pwtype;
663 	if (pw_type < __L2TP_PWTYPE_MAX)
664 		if (l2tp_nl_cmd_ops[pw_type] && l2tp_nl_cmd_ops[pw_type]->session_delete)
665 			ret = (*l2tp_nl_cmd_ops[pw_type]->session_delete)(session);
666 
667 out:
668 	return ret;
669 }
670 
671 static int l2tp_nl_cmd_session_modify(struct sk_buff *skb, struct genl_info *info)
672 {
673 	int ret = 0;
674 	struct l2tp_session *session;
675 
676 	session = l2tp_nl_session_find(info);
677 	if (session == NULL) {
678 		ret = -ENODEV;
679 		goto out;
680 	}
681 
682 	if (info->attrs[L2TP_ATTR_DEBUG])
683 		session->debug = nla_get_u32(info->attrs[L2TP_ATTR_DEBUG]);
684 
685 	if (info->attrs[L2TP_ATTR_DATA_SEQ])
686 		session->data_seq = nla_get_u8(info->attrs[L2TP_ATTR_DATA_SEQ]);
687 
688 	if (info->attrs[L2TP_ATTR_RECV_SEQ])
689 		session->recv_seq = nla_get_u8(info->attrs[L2TP_ATTR_RECV_SEQ]);
690 
691 	if (info->attrs[L2TP_ATTR_SEND_SEQ]) {
692 		session->send_seq = nla_get_u8(info->attrs[L2TP_ATTR_SEND_SEQ]);
693 		l2tp_session_set_header_len(session, session->tunnel->version);
694 	}
695 
696 	if (info->attrs[L2TP_ATTR_LNS_MODE])
697 		session->lns_mode = nla_get_u8(info->attrs[L2TP_ATTR_LNS_MODE]);
698 
699 	if (info->attrs[L2TP_ATTR_RECV_TIMEOUT])
700 		session->reorder_timeout = nla_get_msecs(info->attrs[L2TP_ATTR_RECV_TIMEOUT]);
701 
702 	if (info->attrs[L2TP_ATTR_MTU])
703 		session->mtu = nla_get_u16(info->attrs[L2TP_ATTR_MTU]);
704 
705 	if (info->attrs[L2TP_ATTR_MRU])
706 		session->mru = nla_get_u16(info->attrs[L2TP_ATTR_MRU]);
707 
708 	ret = l2tp_session_notify(&l2tp_nl_family, info,
709 				  session, L2TP_CMD_SESSION_MODIFY);
710 
711 out:
712 	return ret;
713 }
714 
715 static int l2tp_nl_session_send(struct sk_buff *skb, u32 portid, u32 seq, int flags,
716 				struct l2tp_session *session, u8 cmd)
717 {
718 	void *hdr;
719 	struct nlattr *nest;
720 	struct l2tp_tunnel *tunnel = session->tunnel;
721 	struct sock *sk = NULL;
722 
723 	sk = tunnel->sock;
724 
725 	hdr = genlmsg_put(skb, portid, seq, &l2tp_nl_family, flags, cmd);
726 	if (!hdr)
727 		return -EMSGSIZE;
728 
729 	if (nla_put_u32(skb, L2TP_ATTR_CONN_ID, tunnel->tunnel_id) ||
730 	    nla_put_u32(skb, L2TP_ATTR_SESSION_ID, session->session_id) ||
731 	    nla_put_u32(skb, L2TP_ATTR_PEER_CONN_ID, tunnel->peer_tunnel_id) ||
732 	    nla_put_u32(skb, L2TP_ATTR_PEER_SESSION_ID,
733 			session->peer_session_id) ||
734 	    nla_put_u32(skb, L2TP_ATTR_DEBUG, session->debug) ||
735 	    nla_put_u16(skb, L2TP_ATTR_PW_TYPE, session->pwtype) ||
736 	    nla_put_u16(skb, L2TP_ATTR_MTU, session->mtu) ||
737 	    (session->mru &&
738 	     nla_put_u16(skb, L2TP_ATTR_MRU, session->mru)))
739 		goto nla_put_failure;
740 
741 	if ((session->ifname[0] &&
742 	     nla_put_string(skb, L2TP_ATTR_IFNAME, session->ifname)) ||
743 	    (session->cookie_len &&
744 	     nla_put(skb, L2TP_ATTR_COOKIE, session->cookie_len,
745 		     &session->cookie[0])) ||
746 	    (session->peer_cookie_len &&
747 	     nla_put(skb, L2TP_ATTR_PEER_COOKIE, session->peer_cookie_len,
748 		     &session->peer_cookie[0])) ||
749 	    nla_put_u8(skb, L2TP_ATTR_RECV_SEQ, session->recv_seq) ||
750 	    nla_put_u8(skb, L2TP_ATTR_SEND_SEQ, session->send_seq) ||
751 	    nla_put_u8(skb, L2TP_ATTR_LNS_MODE, session->lns_mode) ||
752 #ifdef CONFIG_XFRM
753 	    (((sk) && (sk->sk_policy[0] || sk->sk_policy[1])) &&
754 	     nla_put_u8(skb, L2TP_ATTR_USING_IPSEC, 1)) ||
755 #endif
756 	    (session->reorder_timeout &&
757 	     nla_put_msecs(skb, L2TP_ATTR_RECV_TIMEOUT,
758 			   session->reorder_timeout, L2TP_ATTR_PAD)))
759 		goto nla_put_failure;
760 
761 	nest = nla_nest_start(skb, L2TP_ATTR_STATS);
762 	if (nest == NULL)
763 		goto nla_put_failure;
764 
765 	if (nla_put_u64_64bit(skb, L2TP_ATTR_TX_PACKETS,
766 			      atomic_long_read(&session->stats.tx_packets),
767 			      L2TP_ATTR_STATS_PAD) ||
768 	    nla_put_u64_64bit(skb, L2TP_ATTR_TX_BYTES,
769 			      atomic_long_read(&session->stats.tx_bytes),
770 			      L2TP_ATTR_STATS_PAD) ||
771 	    nla_put_u64_64bit(skb, L2TP_ATTR_TX_ERRORS,
772 			      atomic_long_read(&session->stats.tx_errors),
773 			      L2TP_ATTR_STATS_PAD) ||
774 	    nla_put_u64_64bit(skb, L2TP_ATTR_RX_PACKETS,
775 			      atomic_long_read(&session->stats.rx_packets),
776 			      L2TP_ATTR_STATS_PAD) ||
777 	    nla_put_u64_64bit(skb, L2TP_ATTR_RX_BYTES,
778 			      atomic_long_read(&session->stats.rx_bytes),
779 			      L2TP_ATTR_STATS_PAD) ||
780 	    nla_put_u64_64bit(skb, L2TP_ATTR_RX_SEQ_DISCARDS,
781 			      atomic_long_read(&session->stats.rx_seq_discards),
782 			      L2TP_ATTR_STATS_PAD) ||
783 	    nla_put_u64_64bit(skb, L2TP_ATTR_RX_OOS_PACKETS,
784 			      atomic_long_read(&session->stats.rx_oos_packets),
785 			      L2TP_ATTR_STATS_PAD) ||
786 	    nla_put_u64_64bit(skb, L2TP_ATTR_RX_ERRORS,
787 			      atomic_long_read(&session->stats.rx_errors),
788 			      L2TP_ATTR_STATS_PAD))
789 		goto nla_put_failure;
790 	nla_nest_end(skb, nest);
791 
792 	genlmsg_end(skb, hdr);
793 	return 0;
794 
795  nla_put_failure:
796 	genlmsg_cancel(skb, hdr);
797 	return -1;
798 }
799 
800 static int l2tp_nl_cmd_session_get(struct sk_buff *skb, struct genl_info *info)
801 {
802 	struct l2tp_session *session;
803 	struct sk_buff *msg;
804 	int ret;
805 
806 	session = l2tp_nl_session_find(info);
807 	if (session == NULL) {
808 		ret = -ENODEV;
809 		goto out;
810 	}
811 
812 	msg = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);
813 	if (!msg) {
814 		ret = -ENOMEM;
815 		goto out;
816 	}
817 
818 	ret = l2tp_nl_session_send(msg, info->snd_portid, info->snd_seq,
819 				   0, session, L2TP_CMD_SESSION_GET);
820 	if (ret < 0)
821 		goto err_out;
822 
823 	return genlmsg_unicast(genl_info_net(info), msg, info->snd_portid);
824 
825 err_out:
826 	nlmsg_free(msg);
827 
828 out:
829 	return ret;
830 }
831 
832 static int l2tp_nl_cmd_session_dump(struct sk_buff *skb, struct netlink_callback *cb)
833 {
834 	struct net *net = sock_net(skb->sk);
835 	struct l2tp_session *session;
836 	struct l2tp_tunnel *tunnel = NULL;
837 	int ti = cb->args[0];
838 	int si = cb->args[1];
839 
840 	for (;;) {
841 		if (tunnel == NULL) {
842 			tunnel = l2tp_tunnel_find_nth(net, ti);
843 			if (tunnel == NULL)
844 				goto out;
845 		}
846 
847 		session = l2tp_session_find_nth(tunnel, si);
848 		if (session == NULL) {
849 			ti++;
850 			tunnel = NULL;
851 			si = 0;
852 			continue;
853 		}
854 
855 		if (l2tp_nl_session_send(skb, NETLINK_CB(cb->skb).portid,
856 					 cb->nlh->nlmsg_seq, NLM_F_MULTI,
857 					 session, L2TP_CMD_SESSION_GET) < 0)
858 			break;
859 
860 		si++;
861 	}
862 
863 out:
864 	cb->args[0] = ti;
865 	cb->args[1] = si;
866 
867 	return skb->len;
868 }
869 
870 static struct nla_policy l2tp_nl_policy[L2TP_ATTR_MAX + 1] = {
871 	[L2TP_ATTR_NONE]		= { .type = NLA_UNSPEC, },
872 	[L2TP_ATTR_PW_TYPE]		= { .type = NLA_U16, },
873 	[L2TP_ATTR_ENCAP_TYPE]		= { .type = NLA_U16, },
874 	[L2TP_ATTR_OFFSET]		= { .type = NLA_U16, },
875 	[L2TP_ATTR_DATA_SEQ]		= { .type = NLA_U8, },
876 	[L2TP_ATTR_L2SPEC_TYPE]		= { .type = NLA_U8, },
877 	[L2TP_ATTR_L2SPEC_LEN]		= { .type = NLA_U8, },
878 	[L2TP_ATTR_PROTO_VERSION]	= { .type = NLA_U8, },
879 	[L2TP_ATTR_CONN_ID]		= { .type = NLA_U32, },
880 	[L2TP_ATTR_PEER_CONN_ID]	= { .type = NLA_U32, },
881 	[L2TP_ATTR_SESSION_ID]		= { .type = NLA_U32, },
882 	[L2TP_ATTR_PEER_SESSION_ID]	= { .type = NLA_U32, },
883 	[L2TP_ATTR_UDP_CSUM]		= { .type = NLA_U8, },
884 	[L2TP_ATTR_VLAN_ID]		= { .type = NLA_U16, },
885 	[L2TP_ATTR_DEBUG]		= { .type = NLA_U32, },
886 	[L2TP_ATTR_RECV_SEQ]		= { .type = NLA_U8, },
887 	[L2TP_ATTR_SEND_SEQ]		= { .type = NLA_U8, },
888 	[L2TP_ATTR_LNS_MODE]		= { .type = NLA_U8, },
889 	[L2TP_ATTR_USING_IPSEC]		= { .type = NLA_U8, },
890 	[L2TP_ATTR_RECV_TIMEOUT]	= { .type = NLA_MSECS, },
891 	[L2TP_ATTR_FD]			= { .type = NLA_U32, },
892 	[L2TP_ATTR_IP_SADDR]		= { .type = NLA_U32, },
893 	[L2TP_ATTR_IP_DADDR]		= { .type = NLA_U32, },
894 	[L2TP_ATTR_UDP_SPORT]		= { .type = NLA_U16, },
895 	[L2TP_ATTR_UDP_DPORT]		= { .type = NLA_U16, },
896 	[L2TP_ATTR_MTU]			= { .type = NLA_U16, },
897 	[L2TP_ATTR_MRU]			= { .type = NLA_U16, },
898 	[L2TP_ATTR_STATS]		= { .type = NLA_NESTED, },
899 	[L2TP_ATTR_IP6_SADDR] = {
900 		.type = NLA_BINARY,
901 		.len = sizeof(struct in6_addr),
902 	},
903 	[L2TP_ATTR_IP6_DADDR] = {
904 		.type = NLA_BINARY,
905 		.len = sizeof(struct in6_addr),
906 	},
907 	[L2TP_ATTR_IFNAME] = {
908 		.type = NLA_NUL_STRING,
909 		.len = IFNAMSIZ - 1,
910 	},
911 	[L2TP_ATTR_COOKIE] = {
912 		.type = NLA_BINARY,
913 		.len = 8,
914 	},
915 	[L2TP_ATTR_PEER_COOKIE] = {
916 		.type = NLA_BINARY,
917 		.len = 8,
918 	},
919 };
920 
921 static const struct genl_ops l2tp_nl_ops[] = {
922 	{
923 		.cmd = L2TP_CMD_NOOP,
924 		.doit = l2tp_nl_cmd_noop,
925 		.policy = l2tp_nl_policy,
926 		/* can be retrieved by unprivileged users */
927 	},
928 	{
929 		.cmd = L2TP_CMD_TUNNEL_CREATE,
930 		.doit = l2tp_nl_cmd_tunnel_create,
931 		.policy = l2tp_nl_policy,
932 		.flags = GENL_ADMIN_PERM,
933 	},
934 	{
935 		.cmd = L2TP_CMD_TUNNEL_DELETE,
936 		.doit = l2tp_nl_cmd_tunnel_delete,
937 		.policy = l2tp_nl_policy,
938 		.flags = GENL_ADMIN_PERM,
939 	},
940 	{
941 		.cmd = L2TP_CMD_TUNNEL_MODIFY,
942 		.doit = l2tp_nl_cmd_tunnel_modify,
943 		.policy = l2tp_nl_policy,
944 		.flags = GENL_ADMIN_PERM,
945 	},
946 	{
947 		.cmd = L2TP_CMD_TUNNEL_GET,
948 		.doit = l2tp_nl_cmd_tunnel_get,
949 		.dumpit = l2tp_nl_cmd_tunnel_dump,
950 		.policy = l2tp_nl_policy,
951 		.flags = GENL_ADMIN_PERM,
952 	},
953 	{
954 		.cmd = L2TP_CMD_SESSION_CREATE,
955 		.doit = l2tp_nl_cmd_session_create,
956 		.policy = l2tp_nl_policy,
957 		.flags = GENL_ADMIN_PERM,
958 	},
959 	{
960 		.cmd = L2TP_CMD_SESSION_DELETE,
961 		.doit = l2tp_nl_cmd_session_delete,
962 		.policy = l2tp_nl_policy,
963 		.flags = GENL_ADMIN_PERM,
964 	},
965 	{
966 		.cmd = L2TP_CMD_SESSION_MODIFY,
967 		.doit = l2tp_nl_cmd_session_modify,
968 		.policy = l2tp_nl_policy,
969 		.flags = GENL_ADMIN_PERM,
970 	},
971 	{
972 		.cmd = L2TP_CMD_SESSION_GET,
973 		.doit = l2tp_nl_cmd_session_get,
974 		.dumpit = l2tp_nl_cmd_session_dump,
975 		.policy = l2tp_nl_policy,
976 		.flags = GENL_ADMIN_PERM,
977 	},
978 };
979 
980 int l2tp_nl_register_ops(enum l2tp_pwtype pw_type, const struct l2tp_nl_cmd_ops *ops)
981 {
982 	int ret;
983 
984 	ret = -EINVAL;
985 	if (pw_type >= __L2TP_PWTYPE_MAX)
986 		goto err;
987 
988 	genl_lock();
989 	ret = -EBUSY;
990 	if (l2tp_nl_cmd_ops[pw_type])
991 		goto out;
992 
993 	l2tp_nl_cmd_ops[pw_type] = ops;
994 	ret = 0;
995 
996 out:
997 	genl_unlock();
998 err:
999 	return ret;
1000 }
1001 EXPORT_SYMBOL_GPL(l2tp_nl_register_ops);
1002 
1003 void l2tp_nl_unregister_ops(enum l2tp_pwtype pw_type)
1004 {
1005 	if (pw_type < __L2TP_PWTYPE_MAX) {
1006 		genl_lock();
1007 		l2tp_nl_cmd_ops[pw_type] = NULL;
1008 		genl_unlock();
1009 	}
1010 }
1011 EXPORT_SYMBOL_GPL(l2tp_nl_unregister_ops);
1012 
1013 static int l2tp_nl_init(void)
1014 {
1015 	pr_info("L2TP netlink interface\n");
1016 	return genl_register_family_with_ops_groups(&l2tp_nl_family,
1017 						    l2tp_nl_ops,
1018 						    l2tp_multicast_group);
1019 }
1020 
1021 static void l2tp_nl_cleanup(void)
1022 {
1023 	genl_unregister_family(&l2tp_nl_family);
1024 }
1025 
1026 module_init(l2tp_nl_init);
1027 module_exit(l2tp_nl_cleanup);
1028 
1029 MODULE_AUTHOR("James Chapman <jchapman@katalix.com>");
1030 MODULE_DESCRIPTION("L2TP netlink");
1031 MODULE_LICENSE("GPL");
1032 MODULE_VERSION("1.0");
1033 MODULE_ALIAS_GENL_FAMILY("l2tp");
1034