xref: /openbmc/linux/net/l2tp/l2tp_netlink.c (revision 3e26a691) 
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(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 
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 
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 
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 #ifdef CONFIG_MODULES
590 	if (l2tp_nl_cmd_ops[cfg.pw_type] == NULL) {
591 		genl_unlock();
592 		request_module("net-l2tp-type-%u", cfg.pw_type);
593 		genl_lock();
594 	}
595 #endif
596 	if ((l2tp_nl_cmd_ops[cfg.pw_type] == NULL) ||
597 	    (l2tp_nl_cmd_ops[cfg.pw_type]->session_create == NULL)) {
598 		ret = -EPROTONOSUPPORT;
599 		goto out;
600 	}
601 
602 	/* Check that pseudowire-specific params are present */
603 	switch (cfg.pw_type) {
604 	case L2TP_PWTYPE_NONE:
605 		break;
606 	case L2TP_PWTYPE_ETH_VLAN:
607 		if (!info->attrs[L2TP_ATTR_VLAN_ID]) {
608 			ret = -EINVAL;
609 			goto out;
610 		}
611 		break;
612 	case L2TP_PWTYPE_ETH:
613 		break;
614 	case L2TP_PWTYPE_PPP:
615 	case L2TP_PWTYPE_PPP_AC:
616 		break;
617 	case L2TP_PWTYPE_IP:
618 	default:
619 		ret = -EPROTONOSUPPORT;
620 		break;
621 	}
622 
623 	ret = -EPROTONOSUPPORT;
624 	if (l2tp_nl_cmd_ops[cfg.pw_type]->session_create)
625 		ret = (*l2tp_nl_cmd_ops[cfg.pw_type]->session_create)(net, tunnel_id,
626 			session_id, peer_session_id, &cfg);
627 
628 	if (ret >= 0) {
629 		session = l2tp_session_find(net, tunnel, session_id);
630 		if (session)
631 			ret = l2tp_session_notify(&l2tp_nl_family, info, session,
632 						  L2TP_CMD_SESSION_CREATE);
633 	}
634 
635 out:
636 	return ret;
637 }
638 
639 static int l2tp_nl_cmd_session_delete(struct sk_buff *skb, struct genl_info *info)
640 {
641 	int ret = 0;
642 	struct l2tp_session *session;
643 	u16 pw_type;
644 
645 	session = l2tp_nl_session_find(info);
646 	if (session == NULL) {
647 		ret = -ENODEV;
648 		goto out;
649 	}
650 
651 	l2tp_session_notify(&l2tp_nl_family, info,
652 			    session, L2TP_CMD_SESSION_DELETE);
653 
654 	pw_type = session->pwtype;
655 	if (pw_type < __L2TP_PWTYPE_MAX)
656 		if (l2tp_nl_cmd_ops[pw_type] && l2tp_nl_cmd_ops[pw_type]->session_delete)
657 			ret = (*l2tp_nl_cmd_ops[pw_type]->session_delete)(session);
658 
659 out:
660 	return ret;
661 }
662 
663 static int l2tp_nl_cmd_session_modify(struct sk_buff *skb, struct genl_info *info)
664 {
665 	int ret = 0;
666 	struct l2tp_session *session;
667 
668 	session = l2tp_nl_session_find(info);
669 	if (session == NULL) {
670 		ret = -ENODEV;
671 		goto out;
672 	}
673 
674 	if (info->attrs[L2TP_ATTR_DEBUG])
675 		session->debug = nla_get_u32(info->attrs[L2TP_ATTR_DEBUG]);
676 
677 	if (info->attrs[L2TP_ATTR_DATA_SEQ])
678 		session->data_seq = nla_get_u8(info->attrs[L2TP_ATTR_DATA_SEQ]);
679 
680 	if (info->attrs[L2TP_ATTR_RECV_SEQ])
681 		session->recv_seq = nla_get_u8(info->attrs[L2TP_ATTR_RECV_SEQ]);
682 
683 	if (info->attrs[L2TP_ATTR_SEND_SEQ]) {
684 		session->send_seq = nla_get_u8(info->attrs[L2TP_ATTR_SEND_SEQ]);
685 		l2tp_session_set_header_len(session, session->tunnel->version);
686 	}
687 
688 	if (info->attrs[L2TP_ATTR_LNS_MODE])
689 		session->lns_mode = nla_get_u8(info->attrs[L2TP_ATTR_LNS_MODE]);
690 
691 	if (info->attrs[L2TP_ATTR_RECV_TIMEOUT])
692 		session->reorder_timeout = nla_get_msecs(info->attrs[L2TP_ATTR_RECV_TIMEOUT]);
693 
694 	if (info->attrs[L2TP_ATTR_MTU])
695 		session->mtu = nla_get_u16(info->attrs[L2TP_ATTR_MTU]);
696 
697 	if (info->attrs[L2TP_ATTR_MRU])
698 		session->mru = nla_get_u16(info->attrs[L2TP_ATTR_MRU]);
699 
700 	ret = l2tp_session_notify(&l2tp_nl_family, info,
701 				  session, L2TP_CMD_SESSION_MODIFY);
702 
703 out:
704 	return ret;
705 }
706 
707 static int l2tp_nl_session_send(struct sk_buff *skb, u32 portid, u32 seq, int flags,
708 				struct l2tp_session *session, u8 cmd)
709 {
710 	void *hdr;
711 	struct nlattr *nest;
712 	struct l2tp_tunnel *tunnel = session->tunnel;
713 	struct sock *sk = NULL;
714 
715 	sk = tunnel->sock;
716 
717 	hdr = genlmsg_put(skb, portid, seq, &l2tp_nl_family, flags, cmd);
718 	if (!hdr)
719 		return -EMSGSIZE;
720 
721 	if (nla_put_u32(skb, L2TP_ATTR_CONN_ID, tunnel->tunnel_id) ||
722 	    nla_put_u32(skb, L2TP_ATTR_SESSION_ID, session->session_id) ||
723 	    nla_put_u32(skb, L2TP_ATTR_PEER_CONN_ID, tunnel->peer_tunnel_id) ||
724 	    nla_put_u32(skb, L2TP_ATTR_PEER_SESSION_ID,
725 			session->peer_session_id) ||
726 	    nla_put_u32(skb, L2TP_ATTR_DEBUG, session->debug) ||
727 	    nla_put_u16(skb, L2TP_ATTR_PW_TYPE, session->pwtype) ||
728 	    nla_put_u16(skb, L2TP_ATTR_MTU, session->mtu) ||
729 	    (session->mru &&
730 	     nla_put_u16(skb, L2TP_ATTR_MRU, session->mru)))
731 		goto nla_put_failure;
732 
733 	if ((session->ifname[0] &&
734 	     nla_put_string(skb, L2TP_ATTR_IFNAME, session->ifname)) ||
735 	    (session->cookie_len &&
736 	     nla_put(skb, L2TP_ATTR_COOKIE, session->cookie_len,
737 		     &session->cookie[0])) ||
738 	    (session->peer_cookie_len &&
739 	     nla_put(skb, L2TP_ATTR_PEER_COOKIE, session->peer_cookie_len,
740 		     &session->peer_cookie[0])) ||
741 	    nla_put_u8(skb, L2TP_ATTR_RECV_SEQ, session->recv_seq) ||
742 	    nla_put_u8(skb, L2TP_ATTR_SEND_SEQ, session->send_seq) ||
743 	    nla_put_u8(skb, L2TP_ATTR_LNS_MODE, session->lns_mode) ||
744 #ifdef CONFIG_XFRM
745 	    (((sk) && (sk->sk_policy[0] || sk->sk_policy[1])) &&
746 	     nla_put_u8(skb, L2TP_ATTR_USING_IPSEC, 1)) ||
747 #endif
748 	    (session->reorder_timeout &&
749 	     nla_put_msecs(skb, L2TP_ATTR_RECV_TIMEOUT, session->reorder_timeout)))
750 		goto nla_put_failure;
751 
752 	nest = nla_nest_start(skb, L2TP_ATTR_STATS);
753 	if (nest == NULL)
754 		goto nla_put_failure;
755 
756 	if (nla_put_u64(skb, L2TP_ATTR_TX_PACKETS,
757 		atomic_long_read(&session->stats.tx_packets)) ||
758 	    nla_put_u64(skb, L2TP_ATTR_TX_BYTES,
759 		atomic_long_read(&session->stats.tx_bytes)) ||
760 	    nla_put_u64(skb, L2TP_ATTR_TX_ERRORS,
761 		atomic_long_read(&session->stats.tx_errors)) ||
762 	    nla_put_u64(skb, L2TP_ATTR_RX_PACKETS,
763 		atomic_long_read(&session->stats.rx_packets)) ||
764 	    nla_put_u64(skb, L2TP_ATTR_RX_BYTES,
765 		atomic_long_read(&session->stats.rx_bytes)) ||
766 	    nla_put_u64(skb, L2TP_ATTR_RX_SEQ_DISCARDS,
767 		atomic_long_read(&session->stats.rx_seq_discards)) ||
768 	    nla_put_u64(skb, L2TP_ATTR_RX_OOS_PACKETS,
769 		atomic_long_read(&session->stats.rx_oos_packets)) ||
770 	    nla_put_u64(skb, L2TP_ATTR_RX_ERRORS,
771 		atomic_long_read(&session->stats.rx_errors)))
772 		goto nla_put_failure;
773 	nla_nest_end(skb, nest);
774 
775 	genlmsg_end(skb, hdr);
776 	return 0;
777 
778  nla_put_failure:
779 	genlmsg_cancel(skb, hdr);
780 	return -1;
781 }
782 
783 static int l2tp_nl_cmd_session_get(struct sk_buff *skb, struct genl_info *info)
784 {
785 	struct l2tp_session *session;
786 	struct sk_buff *msg;
787 	int ret;
788 
789 	session = l2tp_nl_session_find(info);
790 	if (session == NULL) {
791 		ret = -ENODEV;
792 		goto out;
793 	}
794 
795 	msg = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);
796 	if (!msg) {
797 		ret = -ENOMEM;
798 		goto out;
799 	}
800 
801 	ret = l2tp_nl_session_send(msg, info->snd_portid, info->snd_seq,
802 				   0, session, L2TP_CMD_SESSION_GET);
803 	if (ret < 0)
804 		goto err_out;
805 
806 	return genlmsg_unicast(genl_info_net(info), msg, info->snd_portid);
807 
808 err_out:
809 	nlmsg_free(msg);
810 
811 out:
812 	return ret;
813 }
814 
815 static int l2tp_nl_cmd_session_dump(struct sk_buff *skb, struct netlink_callback *cb)
816 {
817 	struct net *net = sock_net(skb->sk);
818 	struct l2tp_session *session;
819 	struct l2tp_tunnel *tunnel = NULL;
820 	int ti = cb->args[0];
821 	int si = cb->args[1];
822 
823 	for (;;) {
824 		if (tunnel == NULL) {
825 			tunnel = l2tp_tunnel_find_nth(net, ti);
826 			if (tunnel == NULL)
827 				goto out;
828 		}
829 
830 		session = l2tp_session_find_nth(tunnel, si);
831 		if (session == NULL) {
832 			ti++;
833 			tunnel = NULL;
834 			si = 0;
835 			continue;
836 		}
837 
838 		if (l2tp_nl_session_send(skb, NETLINK_CB(cb->skb).portid,
839 					 cb->nlh->nlmsg_seq, NLM_F_MULTI,
840 					 session, L2TP_CMD_SESSION_GET) < 0)
841 			break;
842 
843 		si++;
844 	}
845 
846 out:
847 	cb->args[0] = ti;
848 	cb->args[1] = si;
849 
850 	return skb->len;
851 }
852 
853 static struct nla_policy l2tp_nl_policy[L2TP_ATTR_MAX + 1] = {
854 	[L2TP_ATTR_NONE]		= { .type = NLA_UNSPEC, },
855 	[L2TP_ATTR_PW_TYPE]		= { .type = NLA_U16, },
856 	[L2TP_ATTR_ENCAP_TYPE]		= { .type = NLA_U16, },
857 	[L2TP_ATTR_OFFSET]		= { .type = NLA_U16, },
858 	[L2TP_ATTR_DATA_SEQ]		= { .type = NLA_U8, },
859 	[L2TP_ATTR_L2SPEC_TYPE]		= { .type = NLA_U8, },
860 	[L2TP_ATTR_L2SPEC_LEN]		= { .type = NLA_U8, },
861 	[L2TP_ATTR_PROTO_VERSION]	= { .type = NLA_U8, },
862 	[L2TP_ATTR_CONN_ID]		= { .type = NLA_U32, },
863 	[L2TP_ATTR_PEER_CONN_ID]	= { .type = NLA_U32, },
864 	[L2TP_ATTR_SESSION_ID]		= { .type = NLA_U32, },
865 	[L2TP_ATTR_PEER_SESSION_ID]	= { .type = NLA_U32, },
866 	[L2TP_ATTR_UDP_CSUM]		= { .type = NLA_U8, },
867 	[L2TP_ATTR_VLAN_ID]		= { .type = NLA_U16, },
868 	[L2TP_ATTR_DEBUG]		= { .type = NLA_U32, },
869 	[L2TP_ATTR_RECV_SEQ]		= { .type = NLA_U8, },
870 	[L2TP_ATTR_SEND_SEQ]		= { .type = NLA_U8, },
871 	[L2TP_ATTR_LNS_MODE]		= { .type = NLA_U8, },
872 	[L2TP_ATTR_USING_IPSEC]		= { .type = NLA_U8, },
873 	[L2TP_ATTR_RECV_TIMEOUT]	= { .type = NLA_MSECS, },
874 	[L2TP_ATTR_FD]			= { .type = NLA_U32, },
875 	[L2TP_ATTR_IP_SADDR]		= { .type = NLA_U32, },
876 	[L2TP_ATTR_IP_DADDR]		= { .type = NLA_U32, },
877 	[L2TP_ATTR_UDP_SPORT]		= { .type = NLA_U16, },
878 	[L2TP_ATTR_UDP_DPORT]		= { .type = NLA_U16, },
879 	[L2TP_ATTR_MTU]			= { .type = NLA_U16, },
880 	[L2TP_ATTR_MRU]			= { .type = NLA_U16, },
881 	[L2TP_ATTR_STATS]		= { .type = NLA_NESTED, },
882 	[L2TP_ATTR_IP6_SADDR] = {
883 		.type = NLA_BINARY,
884 		.len = sizeof(struct in6_addr),
885 	},
886 	[L2TP_ATTR_IP6_DADDR] = {
887 		.type = NLA_BINARY,
888 		.len = sizeof(struct in6_addr),
889 	},
890 	[L2TP_ATTR_IFNAME] = {
891 		.type = NLA_NUL_STRING,
892 		.len = IFNAMSIZ - 1,
893 	},
894 	[L2TP_ATTR_COOKIE] = {
895 		.type = NLA_BINARY,
896 		.len = 8,
897 	},
898 	[L2TP_ATTR_PEER_COOKIE] = {
899 		.type = NLA_BINARY,
900 		.len = 8,
901 	},
902 };
903 
904 static const struct genl_ops l2tp_nl_ops[] = {
905 	{
906 		.cmd = L2TP_CMD_NOOP,
907 		.doit = l2tp_nl_cmd_noop,
908 		.policy = l2tp_nl_policy,
909 		/* can be retrieved by unprivileged users */
910 	},
911 	{
912 		.cmd = L2TP_CMD_TUNNEL_CREATE,
913 		.doit = l2tp_nl_cmd_tunnel_create,
914 		.policy = l2tp_nl_policy,
915 		.flags = GENL_ADMIN_PERM,
916 	},
917 	{
918 		.cmd = L2TP_CMD_TUNNEL_DELETE,
919 		.doit = l2tp_nl_cmd_tunnel_delete,
920 		.policy = l2tp_nl_policy,
921 		.flags = GENL_ADMIN_PERM,
922 	},
923 	{
924 		.cmd = L2TP_CMD_TUNNEL_MODIFY,
925 		.doit = l2tp_nl_cmd_tunnel_modify,
926 		.policy = l2tp_nl_policy,
927 		.flags = GENL_ADMIN_PERM,
928 	},
929 	{
930 		.cmd = L2TP_CMD_TUNNEL_GET,
931 		.doit = l2tp_nl_cmd_tunnel_get,
932 		.dumpit = l2tp_nl_cmd_tunnel_dump,
933 		.policy = l2tp_nl_policy,
934 		.flags = GENL_ADMIN_PERM,
935 	},
936 	{
937 		.cmd = L2TP_CMD_SESSION_CREATE,
938 		.doit = l2tp_nl_cmd_session_create,
939 		.policy = l2tp_nl_policy,
940 		.flags = GENL_ADMIN_PERM,
941 	},
942 	{
943 		.cmd = L2TP_CMD_SESSION_DELETE,
944 		.doit = l2tp_nl_cmd_session_delete,
945 		.policy = l2tp_nl_policy,
946 		.flags = GENL_ADMIN_PERM,
947 	},
948 	{
949 		.cmd = L2TP_CMD_SESSION_MODIFY,
950 		.doit = l2tp_nl_cmd_session_modify,
951 		.policy = l2tp_nl_policy,
952 		.flags = GENL_ADMIN_PERM,
953 	},
954 	{
955 		.cmd = L2TP_CMD_SESSION_GET,
956 		.doit = l2tp_nl_cmd_session_get,
957 		.dumpit = l2tp_nl_cmd_session_dump,
958 		.policy = l2tp_nl_policy,
959 		.flags = GENL_ADMIN_PERM,
960 	},
961 };
962 
963 int l2tp_nl_register_ops(enum l2tp_pwtype pw_type, const struct l2tp_nl_cmd_ops *ops)
964 {
965 	int ret;
966 
967 	ret = -EINVAL;
968 	if (pw_type >= __L2TP_PWTYPE_MAX)
969 		goto err;
970 
971 	genl_lock();
972 	ret = -EBUSY;
973 	if (l2tp_nl_cmd_ops[pw_type])
974 		goto out;
975 
976 	l2tp_nl_cmd_ops[pw_type] = ops;
977 	ret = 0;
978 
979 out:
980 	genl_unlock();
981 err:
982 	return ret;
983 }
984 EXPORT_SYMBOL_GPL(l2tp_nl_register_ops);
985 
986 void l2tp_nl_unregister_ops(enum l2tp_pwtype pw_type)
987 {
988 	if (pw_type < __L2TP_PWTYPE_MAX) {
989 		genl_lock();
990 		l2tp_nl_cmd_ops[pw_type] = NULL;
991 		genl_unlock();
992 	}
993 }
994 EXPORT_SYMBOL_GPL(l2tp_nl_unregister_ops);
995 
996 static int l2tp_nl_init(void)
997 {
998 	pr_info("L2TP netlink interface\n");
999 	return genl_register_family_with_ops_groups(&l2tp_nl_family,
1000 						    l2tp_nl_ops,
1001 						    l2tp_multicast_group);
1002 }
1003 
1004 static void l2tp_nl_cleanup(void)
1005 {
1006 	genl_unregister_family(&l2tp_nl_family);
1007 }
1008 
1009 module_init(l2tp_nl_init);
1010 module_exit(l2tp_nl_cleanup);
1011 
1012 MODULE_AUTHOR("James Chapman <jchapman@katalix.com>");
1013 MODULE_DESCRIPTION("L2TP netlink");
1014 MODULE_LICENSE("GPL");
1015 MODULE_VERSION("1.0");
1016 MODULE_ALIAS_GENL_FAMILY("l2tp");
1017