xref: /openbmc/linux/net/l2tp/l2tp_netlink.c (revision df3305156f989339529b3d6744b898d498fb1f7b)
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 		return genlmsg_multicast_allns(family, msg, 0,	0, GFP_ATOMIC);
129 
130 	nlmsg_free(msg);
131 
132 	return ret;
133 }
134 
135 static int l2tp_session_notify(struct genl_family *family,
136 			       struct genl_info *info,
137 			       struct l2tp_session *session,
138 			       u8 cmd)
139 {
140 	struct sk_buff *msg;
141 	int ret;
142 
143 	msg = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);
144 	if (!msg)
145 		return -ENOMEM;
146 
147 	ret = l2tp_nl_session_send(msg, info->snd_portid, info->snd_seq,
148 				   NLM_F_ACK, session, cmd);
149 
150 	if (ret >= 0)
151 		return genlmsg_multicast_allns(family, msg, 0,	0, GFP_ATOMIC);
152 
153 	nlmsg_free(msg);
154 
155 	return ret;
156 }
157 
158 static int l2tp_nl_cmd_tunnel_create(struct sk_buff *skb, struct genl_info *info)
159 {
160 	u32 tunnel_id;
161 	u32 peer_tunnel_id;
162 	int proto_version;
163 	int fd;
164 	int ret = 0;
165 	struct l2tp_tunnel_cfg cfg = { 0, };
166 	struct l2tp_tunnel *tunnel;
167 	struct net *net = genl_info_net(info);
168 
169 	if (!info->attrs[L2TP_ATTR_CONN_ID]) {
170 		ret = -EINVAL;
171 		goto out;
172 	}
173 	tunnel_id = nla_get_u32(info->attrs[L2TP_ATTR_CONN_ID]);
174 
175 	if (!info->attrs[L2TP_ATTR_PEER_CONN_ID]) {
176 		ret = -EINVAL;
177 		goto out;
178 	}
179 	peer_tunnel_id = nla_get_u32(info->attrs[L2TP_ATTR_PEER_CONN_ID]);
180 
181 	if (!info->attrs[L2TP_ATTR_PROTO_VERSION]) {
182 		ret = -EINVAL;
183 		goto out;
184 	}
185 	proto_version = nla_get_u8(info->attrs[L2TP_ATTR_PROTO_VERSION]);
186 
187 	if (!info->attrs[L2TP_ATTR_ENCAP_TYPE]) {
188 		ret = -EINVAL;
189 		goto out;
190 	}
191 	cfg.encap = nla_get_u16(info->attrs[L2TP_ATTR_ENCAP_TYPE]);
192 
193 	fd = -1;
194 	if (info->attrs[L2TP_ATTR_FD]) {
195 		fd = nla_get_u32(info->attrs[L2TP_ATTR_FD]);
196 	} else {
197 #if IS_ENABLED(CONFIG_IPV6)
198 		if (info->attrs[L2TP_ATTR_IP6_SADDR] &&
199 		    info->attrs[L2TP_ATTR_IP6_DADDR]) {
200 			cfg.local_ip6 = nla_data(
201 				info->attrs[L2TP_ATTR_IP6_SADDR]);
202 			cfg.peer_ip6 = nla_data(
203 				info->attrs[L2TP_ATTR_IP6_DADDR]);
204 		} else
205 #endif
206 		if (info->attrs[L2TP_ATTR_IP_SADDR] &&
207 		    info->attrs[L2TP_ATTR_IP_DADDR]) {
208 			cfg.local_ip.s_addr = nla_get_be32(
209 				info->attrs[L2TP_ATTR_IP_SADDR]);
210 			cfg.peer_ip.s_addr = nla_get_be32(
211 				info->attrs[L2TP_ATTR_IP_DADDR]);
212 		} else {
213 			ret = -EINVAL;
214 			goto out;
215 		}
216 		if (info->attrs[L2TP_ATTR_UDP_SPORT])
217 			cfg.local_udp_port = nla_get_u16(info->attrs[L2TP_ATTR_UDP_SPORT]);
218 		if (info->attrs[L2TP_ATTR_UDP_DPORT])
219 			cfg.peer_udp_port = nla_get_u16(info->attrs[L2TP_ATTR_UDP_DPORT]);
220 		if (info->attrs[L2TP_ATTR_UDP_CSUM])
221 			cfg.use_udp_checksums = nla_get_flag(info->attrs[L2TP_ATTR_UDP_CSUM]);
222 
223 #if IS_ENABLED(CONFIG_IPV6)
224 		if (info->attrs[L2TP_ATTR_UDP_ZERO_CSUM6_TX])
225 			cfg.udp6_zero_tx_checksums = nla_get_flag(info->attrs[L2TP_ATTR_UDP_ZERO_CSUM6_TX]);
226 		if (info->attrs[L2TP_ATTR_UDP_ZERO_CSUM6_RX])
227 			cfg.udp6_zero_rx_checksums = nla_get_flag(info->attrs[L2TP_ATTR_UDP_ZERO_CSUM6_RX]);
228 #endif
229 	}
230 
231 	if (info->attrs[L2TP_ATTR_DEBUG])
232 		cfg.debug = nla_get_u32(info->attrs[L2TP_ATTR_DEBUG]);
233 
234 	tunnel = l2tp_tunnel_find(net, tunnel_id);
235 	if (tunnel != NULL) {
236 		ret = -EEXIST;
237 		goto out;
238 	}
239 
240 	ret = -EINVAL;
241 	switch (cfg.encap) {
242 	case L2TP_ENCAPTYPE_UDP:
243 	case L2TP_ENCAPTYPE_IP:
244 		ret = l2tp_tunnel_create(net, fd, proto_version, tunnel_id,
245 					 peer_tunnel_id, &cfg, &tunnel);
246 		break;
247 	}
248 
249 	if (ret >= 0)
250 		ret = l2tp_tunnel_notify(&l2tp_nl_family, info,
251 					 tunnel, L2TP_CMD_TUNNEL_CREATE);
252 out:
253 	return ret;
254 }
255 
256 static int l2tp_nl_cmd_tunnel_delete(struct sk_buff *skb, struct genl_info *info)
257 {
258 	struct l2tp_tunnel *tunnel;
259 	u32 tunnel_id;
260 	int ret = 0;
261 	struct net *net = genl_info_net(info);
262 
263 	if (!info->attrs[L2TP_ATTR_CONN_ID]) {
264 		ret = -EINVAL;
265 		goto out;
266 	}
267 	tunnel_id = nla_get_u32(info->attrs[L2TP_ATTR_CONN_ID]);
268 
269 	tunnel = l2tp_tunnel_find(net, tunnel_id);
270 	if (tunnel == NULL) {
271 		ret = -ENODEV;
272 		goto out;
273 	}
274 
275 	l2tp_tunnel_notify(&l2tp_nl_family, info,
276 			   tunnel, L2TP_CMD_TUNNEL_DELETE);
277 
278 	(void) l2tp_tunnel_delete(tunnel);
279 
280 out:
281 	return ret;
282 }
283 
284 static int l2tp_nl_cmd_tunnel_modify(struct sk_buff *skb, struct genl_info *info)
285 {
286 	struct l2tp_tunnel *tunnel;
287 	u32 tunnel_id;
288 	int ret = 0;
289 	struct net *net = genl_info_net(info);
290 
291 	if (!info->attrs[L2TP_ATTR_CONN_ID]) {
292 		ret = -EINVAL;
293 		goto out;
294 	}
295 	tunnel_id = nla_get_u32(info->attrs[L2TP_ATTR_CONN_ID]);
296 
297 	tunnel = l2tp_tunnel_find(net, tunnel_id);
298 	if (tunnel == NULL) {
299 		ret = -ENODEV;
300 		goto out;
301 	}
302 
303 	if (info->attrs[L2TP_ATTR_DEBUG])
304 		tunnel->debug = nla_get_u32(info->attrs[L2TP_ATTR_DEBUG]);
305 
306 	ret = l2tp_tunnel_notify(&l2tp_nl_family, info,
307 				 tunnel, L2TP_CMD_TUNNEL_MODIFY);
308 
309 out:
310 	return ret;
311 }
312 
313 static int l2tp_nl_tunnel_send(struct sk_buff *skb, u32 portid, u32 seq, int flags,
314 			       struct l2tp_tunnel *tunnel, u8 cmd)
315 {
316 	void *hdr;
317 	struct nlattr *nest;
318 	struct sock *sk = NULL;
319 	struct inet_sock *inet;
320 #if IS_ENABLED(CONFIG_IPV6)
321 	struct ipv6_pinfo *np = NULL;
322 #endif
323 
324 	hdr = genlmsg_put(skb, portid, seq, &l2tp_nl_family, flags, cmd);
325 	if (!hdr)
326 		return -EMSGSIZE;
327 
328 	if (nla_put_u8(skb, L2TP_ATTR_PROTO_VERSION, tunnel->version) ||
329 	    nla_put_u32(skb, L2TP_ATTR_CONN_ID, tunnel->tunnel_id) ||
330 	    nla_put_u32(skb, L2TP_ATTR_PEER_CONN_ID, tunnel->peer_tunnel_id) ||
331 	    nla_put_u32(skb, L2TP_ATTR_DEBUG, tunnel->debug) ||
332 	    nla_put_u16(skb, L2TP_ATTR_ENCAP_TYPE, tunnel->encap))
333 		goto nla_put_failure;
334 
335 	nest = nla_nest_start(skb, L2TP_ATTR_STATS);
336 	if (nest == NULL)
337 		goto nla_put_failure;
338 
339 	if (nla_put_u64(skb, L2TP_ATTR_TX_PACKETS,
340 		    atomic_long_read(&tunnel->stats.tx_packets)) ||
341 	    nla_put_u64(skb, L2TP_ATTR_TX_BYTES,
342 		    atomic_long_read(&tunnel->stats.tx_bytes)) ||
343 	    nla_put_u64(skb, L2TP_ATTR_TX_ERRORS,
344 		    atomic_long_read(&tunnel->stats.tx_errors)) ||
345 	    nla_put_u64(skb, L2TP_ATTR_RX_PACKETS,
346 		    atomic_long_read(&tunnel->stats.rx_packets)) ||
347 	    nla_put_u64(skb, L2TP_ATTR_RX_BYTES,
348 		    atomic_long_read(&tunnel->stats.rx_bytes)) ||
349 	    nla_put_u64(skb, L2TP_ATTR_RX_SEQ_DISCARDS,
350 		    atomic_long_read(&tunnel->stats.rx_seq_discards)) ||
351 	    nla_put_u64(skb, L2TP_ATTR_RX_OOS_PACKETS,
352 		    atomic_long_read(&tunnel->stats.rx_oos_packets)) ||
353 	    nla_put_u64(skb, L2TP_ATTR_RX_ERRORS,
354 		    atomic_long_read(&tunnel->stats.rx_errors)))
355 		goto nla_put_failure;
356 	nla_nest_end(skb, nest);
357 
358 	sk = tunnel->sock;
359 	if (!sk)
360 		goto out;
361 
362 #if IS_ENABLED(CONFIG_IPV6)
363 	if (sk->sk_family == AF_INET6)
364 		np = inet6_sk(sk);
365 #endif
366 
367 	inet = inet_sk(sk);
368 
369 	switch (tunnel->encap) {
370 	case L2TP_ENCAPTYPE_UDP:
371 		if (nla_put_u16(skb, L2TP_ATTR_UDP_SPORT, ntohs(inet->inet_sport)) ||
372 		    nla_put_u16(skb, L2TP_ATTR_UDP_DPORT, ntohs(inet->inet_dport)) ||
373 		    nla_put_u8(skb, L2TP_ATTR_UDP_CSUM, !sk->sk_no_check_tx))
374 			goto nla_put_failure;
375 		/* NOBREAK */
376 	case L2TP_ENCAPTYPE_IP:
377 #if IS_ENABLED(CONFIG_IPV6)
378 		if (np) {
379 			if (nla_put(skb, L2TP_ATTR_IP6_SADDR, sizeof(np->saddr),
380 				    &np->saddr) ||
381 			    nla_put(skb, L2TP_ATTR_IP6_DADDR, sizeof(sk->sk_v6_daddr),
382 				    &sk->sk_v6_daddr))
383 				goto nla_put_failure;
384 		} else
385 #endif
386 		if (nla_put_be32(skb, L2TP_ATTR_IP_SADDR, inet->inet_saddr) ||
387 		    nla_put_be32(skb, L2TP_ATTR_IP_DADDR, inet->inet_daddr))
388 			goto nla_put_failure;
389 		break;
390 	}
391 
392 out:
393 	genlmsg_end(skb, hdr);
394 	return 0;
395 
396 nla_put_failure:
397 	genlmsg_cancel(skb, hdr);
398 	return -1;
399 }
400 
401 static int l2tp_nl_cmd_tunnel_get(struct sk_buff *skb, struct genl_info *info)
402 {
403 	struct l2tp_tunnel *tunnel;
404 	struct sk_buff *msg;
405 	u32 tunnel_id;
406 	int ret = -ENOBUFS;
407 	struct net *net = genl_info_net(info);
408 
409 	if (!info->attrs[L2TP_ATTR_CONN_ID]) {
410 		ret = -EINVAL;
411 		goto out;
412 	}
413 
414 	tunnel_id = nla_get_u32(info->attrs[L2TP_ATTR_CONN_ID]);
415 
416 	tunnel = l2tp_tunnel_find(net, tunnel_id);
417 	if (tunnel == NULL) {
418 		ret = -ENODEV;
419 		goto out;
420 	}
421 
422 	msg = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);
423 	if (!msg) {
424 		ret = -ENOMEM;
425 		goto out;
426 	}
427 
428 	ret = l2tp_nl_tunnel_send(msg, info->snd_portid, info->snd_seq,
429 				  NLM_F_ACK, tunnel, L2TP_CMD_TUNNEL_GET);
430 	if (ret < 0)
431 		goto err_out;
432 
433 	return genlmsg_unicast(net, msg, info->snd_portid);
434 
435 err_out:
436 	nlmsg_free(msg);
437 
438 out:
439 	return ret;
440 }
441 
442 static int l2tp_nl_cmd_tunnel_dump(struct sk_buff *skb, struct netlink_callback *cb)
443 {
444 	int ti = cb->args[0];
445 	struct l2tp_tunnel *tunnel;
446 	struct net *net = sock_net(skb->sk);
447 
448 	for (;;) {
449 		tunnel = l2tp_tunnel_find_nth(net, ti);
450 		if (tunnel == NULL)
451 			goto out;
452 
453 		if (l2tp_nl_tunnel_send(skb, NETLINK_CB(cb->skb).portid,
454 					cb->nlh->nlmsg_seq, NLM_F_MULTI,
455 					tunnel, L2TP_CMD_TUNNEL_GET) < 0)
456 			goto out;
457 
458 		ti++;
459 	}
460 
461 out:
462 	cb->args[0] = ti;
463 
464 	return skb->len;
465 }
466 
467 static int l2tp_nl_cmd_session_create(struct sk_buff *skb, struct genl_info *info)
468 {
469 	u32 tunnel_id = 0;
470 	u32 session_id;
471 	u32 peer_session_id;
472 	int ret = 0;
473 	struct l2tp_tunnel *tunnel;
474 	struct l2tp_session *session;
475 	struct l2tp_session_cfg cfg = { 0, };
476 	struct net *net = genl_info_net(info);
477 
478 	if (!info->attrs[L2TP_ATTR_CONN_ID]) {
479 		ret = -EINVAL;
480 		goto out;
481 	}
482 	tunnel_id = nla_get_u32(info->attrs[L2TP_ATTR_CONN_ID]);
483 	tunnel = l2tp_tunnel_find(net, tunnel_id);
484 	if (!tunnel) {
485 		ret = -ENODEV;
486 		goto out;
487 	}
488 
489 	if (!info->attrs[L2TP_ATTR_SESSION_ID]) {
490 		ret = -EINVAL;
491 		goto out;
492 	}
493 	session_id = nla_get_u32(info->attrs[L2TP_ATTR_SESSION_ID]);
494 	session = l2tp_session_find(net, tunnel, session_id);
495 	if (session) {
496 		ret = -EEXIST;
497 		goto out;
498 	}
499 
500 	if (!info->attrs[L2TP_ATTR_PEER_SESSION_ID]) {
501 		ret = -EINVAL;
502 		goto out;
503 	}
504 	peer_session_id = nla_get_u32(info->attrs[L2TP_ATTR_PEER_SESSION_ID]);
505 
506 	if (!info->attrs[L2TP_ATTR_PW_TYPE]) {
507 		ret = -EINVAL;
508 		goto out;
509 	}
510 	cfg.pw_type = nla_get_u16(info->attrs[L2TP_ATTR_PW_TYPE]);
511 	if (cfg.pw_type >= __L2TP_PWTYPE_MAX) {
512 		ret = -EINVAL;
513 		goto out;
514 	}
515 
516 	if (tunnel->version > 2) {
517 		if (info->attrs[L2TP_ATTR_OFFSET])
518 			cfg.offset = nla_get_u16(info->attrs[L2TP_ATTR_OFFSET]);
519 
520 		if (info->attrs[L2TP_ATTR_DATA_SEQ])
521 			cfg.data_seq = nla_get_u8(info->attrs[L2TP_ATTR_DATA_SEQ]);
522 
523 		cfg.l2specific_type = L2TP_L2SPECTYPE_DEFAULT;
524 		if (info->attrs[L2TP_ATTR_L2SPEC_TYPE])
525 			cfg.l2specific_type = nla_get_u8(info->attrs[L2TP_ATTR_L2SPEC_TYPE]);
526 
527 		cfg.l2specific_len = 4;
528 		if (info->attrs[L2TP_ATTR_L2SPEC_LEN])
529 			cfg.l2specific_len = nla_get_u8(info->attrs[L2TP_ATTR_L2SPEC_LEN]);
530 
531 		if (info->attrs[L2TP_ATTR_COOKIE]) {
532 			u16 len = nla_len(info->attrs[L2TP_ATTR_COOKIE]);
533 			if (len > 8) {
534 				ret = -EINVAL;
535 				goto out;
536 			}
537 			cfg.cookie_len = len;
538 			memcpy(&cfg.cookie[0], nla_data(info->attrs[L2TP_ATTR_COOKIE]), len);
539 		}
540 		if (info->attrs[L2TP_ATTR_PEER_COOKIE]) {
541 			u16 len = nla_len(info->attrs[L2TP_ATTR_PEER_COOKIE]);
542 			if (len > 8) {
543 				ret = -EINVAL;
544 				goto out;
545 			}
546 			cfg.peer_cookie_len = len;
547 			memcpy(&cfg.peer_cookie[0], nla_data(info->attrs[L2TP_ATTR_PEER_COOKIE]), len);
548 		}
549 		if (info->attrs[L2TP_ATTR_IFNAME])
550 			cfg.ifname = nla_data(info->attrs[L2TP_ATTR_IFNAME]);
551 
552 		if (info->attrs[L2TP_ATTR_VLAN_ID])
553 			cfg.vlan_id = nla_get_u16(info->attrs[L2TP_ATTR_VLAN_ID]);
554 	}
555 
556 	if (info->attrs[L2TP_ATTR_DEBUG])
557 		cfg.debug = nla_get_u32(info->attrs[L2TP_ATTR_DEBUG]);
558 
559 	if (info->attrs[L2TP_ATTR_RECV_SEQ])
560 		cfg.recv_seq = nla_get_u8(info->attrs[L2TP_ATTR_RECV_SEQ]);
561 
562 	if (info->attrs[L2TP_ATTR_SEND_SEQ])
563 		cfg.send_seq = nla_get_u8(info->attrs[L2TP_ATTR_SEND_SEQ]);
564 
565 	if (info->attrs[L2TP_ATTR_LNS_MODE])
566 		cfg.lns_mode = nla_get_u8(info->attrs[L2TP_ATTR_LNS_MODE]);
567 
568 	if (info->attrs[L2TP_ATTR_RECV_TIMEOUT])
569 		cfg.reorder_timeout = nla_get_msecs(info->attrs[L2TP_ATTR_RECV_TIMEOUT]);
570 
571 	if (info->attrs[L2TP_ATTR_MTU])
572 		cfg.mtu = nla_get_u16(info->attrs[L2TP_ATTR_MTU]);
573 
574 	if (info->attrs[L2TP_ATTR_MRU])
575 		cfg.mru = nla_get_u16(info->attrs[L2TP_ATTR_MRU]);
576 
577 	if ((l2tp_nl_cmd_ops[cfg.pw_type] == NULL) ||
578 	    (l2tp_nl_cmd_ops[cfg.pw_type]->session_create == NULL)) {
579 		ret = -EPROTONOSUPPORT;
580 		goto out;
581 	}
582 
583 	/* Check that pseudowire-specific params are present */
584 	switch (cfg.pw_type) {
585 	case L2TP_PWTYPE_NONE:
586 		break;
587 	case L2TP_PWTYPE_ETH_VLAN:
588 		if (!info->attrs[L2TP_ATTR_VLAN_ID]) {
589 			ret = -EINVAL;
590 			goto out;
591 		}
592 		break;
593 	case L2TP_PWTYPE_ETH:
594 		break;
595 	case L2TP_PWTYPE_PPP:
596 	case L2TP_PWTYPE_PPP_AC:
597 		break;
598 	case L2TP_PWTYPE_IP:
599 	default:
600 		ret = -EPROTONOSUPPORT;
601 		break;
602 	}
603 
604 	ret = -EPROTONOSUPPORT;
605 	if (l2tp_nl_cmd_ops[cfg.pw_type]->session_create)
606 		ret = (*l2tp_nl_cmd_ops[cfg.pw_type]->session_create)(net, tunnel_id,
607 			session_id, peer_session_id, &cfg);
608 
609 	if (ret >= 0) {
610 		session = l2tp_session_find(net, tunnel, session_id);
611 		if (session)
612 			ret = l2tp_session_notify(&l2tp_nl_family, info, session,
613 						  L2TP_CMD_SESSION_CREATE);
614 	}
615 
616 out:
617 	return ret;
618 }
619 
620 static int l2tp_nl_cmd_session_delete(struct sk_buff *skb, struct genl_info *info)
621 {
622 	int ret = 0;
623 	struct l2tp_session *session;
624 	u16 pw_type;
625 
626 	session = l2tp_nl_session_find(info);
627 	if (session == NULL) {
628 		ret = -ENODEV;
629 		goto out;
630 	}
631 
632 	l2tp_session_notify(&l2tp_nl_family, info,
633 			    session, L2TP_CMD_SESSION_DELETE);
634 
635 	pw_type = session->pwtype;
636 	if (pw_type < __L2TP_PWTYPE_MAX)
637 		if (l2tp_nl_cmd_ops[pw_type] && l2tp_nl_cmd_ops[pw_type]->session_delete)
638 			ret = (*l2tp_nl_cmd_ops[pw_type]->session_delete)(session);
639 
640 out:
641 	return ret;
642 }
643 
644 static int l2tp_nl_cmd_session_modify(struct sk_buff *skb, struct genl_info *info)
645 {
646 	int ret = 0;
647 	struct l2tp_session *session;
648 
649 	session = l2tp_nl_session_find(info);
650 	if (session == NULL) {
651 		ret = -ENODEV;
652 		goto out;
653 	}
654 
655 	if (info->attrs[L2TP_ATTR_DEBUG])
656 		session->debug = nla_get_u32(info->attrs[L2TP_ATTR_DEBUG]);
657 
658 	if (info->attrs[L2TP_ATTR_DATA_SEQ])
659 		session->data_seq = nla_get_u8(info->attrs[L2TP_ATTR_DATA_SEQ]);
660 
661 	if (info->attrs[L2TP_ATTR_RECV_SEQ])
662 		session->recv_seq = nla_get_u8(info->attrs[L2TP_ATTR_RECV_SEQ]);
663 
664 	if (info->attrs[L2TP_ATTR_SEND_SEQ]) {
665 		session->send_seq = nla_get_u8(info->attrs[L2TP_ATTR_SEND_SEQ]);
666 		l2tp_session_set_header_len(session, session->tunnel->version);
667 	}
668 
669 	if (info->attrs[L2TP_ATTR_LNS_MODE])
670 		session->lns_mode = nla_get_u8(info->attrs[L2TP_ATTR_LNS_MODE]);
671 
672 	if (info->attrs[L2TP_ATTR_RECV_TIMEOUT])
673 		session->reorder_timeout = nla_get_msecs(info->attrs[L2TP_ATTR_RECV_TIMEOUT]);
674 
675 	if (info->attrs[L2TP_ATTR_MTU])
676 		session->mtu = nla_get_u16(info->attrs[L2TP_ATTR_MTU]);
677 
678 	if (info->attrs[L2TP_ATTR_MRU])
679 		session->mru = nla_get_u16(info->attrs[L2TP_ATTR_MRU]);
680 
681 	ret = l2tp_session_notify(&l2tp_nl_family, info,
682 				  session, L2TP_CMD_SESSION_MODIFY);
683 
684 out:
685 	return ret;
686 }
687 
688 static int l2tp_nl_session_send(struct sk_buff *skb, u32 portid, u32 seq, int flags,
689 				struct l2tp_session *session, u8 cmd)
690 {
691 	void *hdr;
692 	struct nlattr *nest;
693 	struct l2tp_tunnel *tunnel = session->tunnel;
694 	struct sock *sk = NULL;
695 
696 	sk = tunnel->sock;
697 
698 	hdr = genlmsg_put(skb, portid, seq, &l2tp_nl_family, flags, cmd);
699 	if (!hdr)
700 		return -EMSGSIZE;
701 
702 	if (nla_put_u32(skb, L2TP_ATTR_CONN_ID, tunnel->tunnel_id) ||
703 	    nla_put_u32(skb, L2TP_ATTR_SESSION_ID, session->session_id) ||
704 	    nla_put_u32(skb, L2TP_ATTR_PEER_CONN_ID, tunnel->peer_tunnel_id) ||
705 	    nla_put_u32(skb, L2TP_ATTR_PEER_SESSION_ID,
706 			session->peer_session_id) ||
707 	    nla_put_u32(skb, L2TP_ATTR_DEBUG, session->debug) ||
708 	    nla_put_u16(skb, L2TP_ATTR_PW_TYPE, session->pwtype) ||
709 	    nla_put_u16(skb, L2TP_ATTR_MTU, session->mtu) ||
710 	    (session->mru &&
711 	     nla_put_u16(skb, L2TP_ATTR_MRU, session->mru)))
712 		goto nla_put_failure;
713 
714 	if ((session->ifname[0] &&
715 	     nla_put_string(skb, L2TP_ATTR_IFNAME, session->ifname)) ||
716 	    (session->cookie_len &&
717 	     nla_put(skb, L2TP_ATTR_COOKIE, session->cookie_len,
718 		     &session->cookie[0])) ||
719 	    (session->peer_cookie_len &&
720 	     nla_put(skb, L2TP_ATTR_PEER_COOKIE, session->peer_cookie_len,
721 		     &session->peer_cookie[0])) ||
722 	    nla_put_u8(skb, L2TP_ATTR_RECV_SEQ, session->recv_seq) ||
723 	    nla_put_u8(skb, L2TP_ATTR_SEND_SEQ, session->send_seq) ||
724 	    nla_put_u8(skb, L2TP_ATTR_LNS_MODE, session->lns_mode) ||
725 #ifdef CONFIG_XFRM
726 	    (((sk) && (sk->sk_policy[0] || sk->sk_policy[1])) &&
727 	     nla_put_u8(skb, L2TP_ATTR_USING_IPSEC, 1)) ||
728 #endif
729 	    (session->reorder_timeout &&
730 	     nla_put_msecs(skb, L2TP_ATTR_RECV_TIMEOUT, session->reorder_timeout)))
731 		goto nla_put_failure;
732 
733 	nest = nla_nest_start(skb, L2TP_ATTR_STATS);
734 	if (nest == NULL)
735 		goto nla_put_failure;
736 
737 	if (nla_put_u64(skb, L2TP_ATTR_TX_PACKETS,
738 		atomic_long_read(&session->stats.tx_packets)) ||
739 	    nla_put_u64(skb, L2TP_ATTR_TX_BYTES,
740 		atomic_long_read(&session->stats.tx_bytes)) ||
741 	    nla_put_u64(skb, L2TP_ATTR_TX_ERRORS,
742 		atomic_long_read(&session->stats.tx_errors)) ||
743 	    nla_put_u64(skb, L2TP_ATTR_RX_PACKETS,
744 		atomic_long_read(&session->stats.rx_packets)) ||
745 	    nla_put_u64(skb, L2TP_ATTR_RX_BYTES,
746 		atomic_long_read(&session->stats.rx_bytes)) ||
747 	    nla_put_u64(skb, L2TP_ATTR_RX_SEQ_DISCARDS,
748 		atomic_long_read(&session->stats.rx_seq_discards)) ||
749 	    nla_put_u64(skb, L2TP_ATTR_RX_OOS_PACKETS,
750 		atomic_long_read(&session->stats.rx_oos_packets)) ||
751 	    nla_put_u64(skb, L2TP_ATTR_RX_ERRORS,
752 		atomic_long_read(&session->stats.rx_errors)))
753 		goto nla_put_failure;
754 	nla_nest_end(skb, nest);
755 
756 	genlmsg_end(skb, hdr);
757 	return 0;
758 
759  nla_put_failure:
760 	genlmsg_cancel(skb, hdr);
761 	return -1;
762 }
763 
764 static int l2tp_nl_cmd_session_get(struct sk_buff *skb, struct genl_info *info)
765 {
766 	struct l2tp_session *session;
767 	struct sk_buff *msg;
768 	int ret;
769 
770 	session = l2tp_nl_session_find(info);
771 	if (session == NULL) {
772 		ret = -ENODEV;
773 		goto out;
774 	}
775 
776 	msg = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);
777 	if (!msg) {
778 		ret = -ENOMEM;
779 		goto out;
780 	}
781 
782 	ret = l2tp_nl_session_send(msg, info->snd_portid, info->snd_seq,
783 				   0, session, L2TP_CMD_SESSION_GET);
784 	if (ret < 0)
785 		goto err_out;
786 
787 	return genlmsg_unicast(genl_info_net(info), msg, info->snd_portid);
788 
789 err_out:
790 	nlmsg_free(msg);
791 
792 out:
793 	return ret;
794 }
795 
796 static int l2tp_nl_cmd_session_dump(struct sk_buff *skb, struct netlink_callback *cb)
797 {
798 	struct net *net = sock_net(skb->sk);
799 	struct l2tp_session *session;
800 	struct l2tp_tunnel *tunnel = NULL;
801 	int ti = cb->args[0];
802 	int si = cb->args[1];
803 
804 	for (;;) {
805 		if (tunnel == NULL) {
806 			tunnel = l2tp_tunnel_find_nth(net, ti);
807 			if (tunnel == NULL)
808 				goto out;
809 		}
810 
811 		session = l2tp_session_find_nth(tunnel, si);
812 		if (session == NULL) {
813 			ti++;
814 			tunnel = NULL;
815 			si = 0;
816 			continue;
817 		}
818 
819 		if (l2tp_nl_session_send(skb, NETLINK_CB(cb->skb).portid,
820 					 cb->nlh->nlmsg_seq, NLM_F_MULTI,
821 					 session, L2TP_CMD_SESSION_GET) < 0)
822 			break;
823 
824 		si++;
825 	}
826 
827 out:
828 	cb->args[0] = ti;
829 	cb->args[1] = si;
830 
831 	return skb->len;
832 }
833 
834 static struct nla_policy l2tp_nl_policy[L2TP_ATTR_MAX + 1] = {
835 	[L2TP_ATTR_NONE]		= { .type = NLA_UNSPEC, },
836 	[L2TP_ATTR_PW_TYPE]		= { .type = NLA_U16, },
837 	[L2TP_ATTR_ENCAP_TYPE]		= { .type = NLA_U16, },
838 	[L2TP_ATTR_OFFSET]		= { .type = NLA_U16, },
839 	[L2TP_ATTR_DATA_SEQ]		= { .type = NLA_U8, },
840 	[L2TP_ATTR_L2SPEC_TYPE]		= { .type = NLA_U8, },
841 	[L2TP_ATTR_L2SPEC_LEN]		= { .type = NLA_U8, },
842 	[L2TP_ATTR_PROTO_VERSION]	= { .type = NLA_U8, },
843 	[L2TP_ATTR_CONN_ID]		= { .type = NLA_U32, },
844 	[L2TP_ATTR_PEER_CONN_ID]	= { .type = NLA_U32, },
845 	[L2TP_ATTR_SESSION_ID]		= { .type = NLA_U32, },
846 	[L2TP_ATTR_PEER_SESSION_ID]	= { .type = NLA_U32, },
847 	[L2TP_ATTR_UDP_CSUM]		= { .type = NLA_U8, },
848 	[L2TP_ATTR_VLAN_ID]		= { .type = NLA_U16, },
849 	[L2TP_ATTR_DEBUG]		= { .type = NLA_U32, },
850 	[L2TP_ATTR_RECV_SEQ]		= { .type = NLA_U8, },
851 	[L2TP_ATTR_SEND_SEQ]		= { .type = NLA_U8, },
852 	[L2TP_ATTR_LNS_MODE]		= { .type = NLA_U8, },
853 	[L2TP_ATTR_USING_IPSEC]		= { .type = NLA_U8, },
854 	[L2TP_ATTR_RECV_TIMEOUT]	= { .type = NLA_MSECS, },
855 	[L2TP_ATTR_FD]			= { .type = NLA_U32, },
856 	[L2TP_ATTR_IP_SADDR]		= { .type = NLA_U32, },
857 	[L2TP_ATTR_IP_DADDR]		= { .type = NLA_U32, },
858 	[L2TP_ATTR_UDP_SPORT]		= { .type = NLA_U16, },
859 	[L2TP_ATTR_UDP_DPORT]		= { .type = NLA_U16, },
860 	[L2TP_ATTR_MTU]			= { .type = NLA_U16, },
861 	[L2TP_ATTR_MRU]			= { .type = NLA_U16, },
862 	[L2TP_ATTR_STATS]		= { .type = NLA_NESTED, },
863 	[L2TP_ATTR_IP6_SADDR] = {
864 		.type = NLA_BINARY,
865 		.len = sizeof(struct in6_addr),
866 	},
867 	[L2TP_ATTR_IP6_DADDR] = {
868 		.type = NLA_BINARY,
869 		.len = sizeof(struct in6_addr),
870 	},
871 	[L2TP_ATTR_IFNAME] = {
872 		.type = NLA_NUL_STRING,
873 		.len = IFNAMSIZ - 1,
874 	},
875 	[L2TP_ATTR_COOKIE] = {
876 		.type = NLA_BINARY,
877 		.len = 8,
878 	},
879 	[L2TP_ATTR_PEER_COOKIE] = {
880 		.type = NLA_BINARY,
881 		.len = 8,
882 	},
883 };
884 
885 static const struct genl_ops l2tp_nl_ops[] = {
886 	{
887 		.cmd = L2TP_CMD_NOOP,
888 		.doit = l2tp_nl_cmd_noop,
889 		.policy = l2tp_nl_policy,
890 		/* can be retrieved by unprivileged users */
891 	},
892 	{
893 		.cmd = L2TP_CMD_TUNNEL_CREATE,
894 		.doit = l2tp_nl_cmd_tunnel_create,
895 		.policy = l2tp_nl_policy,
896 		.flags = GENL_ADMIN_PERM,
897 	},
898 	{
899 		.cmd = L2TP_CMD_TUNNEL_DELETE,
900 		.doit = l2tp_nl_cmd_tunnel_delete,
901 		.policy = l2tp_nl_policy,
902 		.flags = GENL_ADMIN_PERM,
903 	},
904 	{
905 		.cmd = L2TP_CMD_TUNNEL_MODIFY,
906 		.doit = l2tp_nl_cmd_tunnel_modify,
907 		.policy = l2tp_nl_policy,
908 		.flags = GENL_ADMIN_PERM,
909 	},
910 	{
911 		.cmd = L2TP_CMD_TUNNEL_GET,
912 		.doit = l2tp_nl_cmd_tunnel_get,
913 		.dumpit = l2tp_nl_cmd_tunnel_dump,
914 		.policy = l2tp_nl_policy,
915 		.flags = GENL_ADMIN_PERM,
916 	},
917 	{
918 		.cmd = L2TP_CMD_SESSION_CREATE,
919 		.doit = l2tp_nl_cmd_session_create,
920 		.policy = l2tp_nl_policy,
921 		.flags = GENL_ADMIN_PERM,
922 	},
923 	{
924 		.cmd = L2TP_CMD_SESSION_DELETE,
925 		.doit = l2tp_nl_cmd_session_delete,
926 		.policy = l2tp_nl_policy,
927 		.flags = GENL_ADMIN_PERM,
928 	},
929 	{
930 		.cmd = L2TP_CMD_SESSION_MODIFY,
931 		.doit = l2tp_nl_cmd_session_modify,
932 		.policy = l2tp_nl_policy,
933 		.flags = GENL_ADMIN_PERM,
934 	},
935 	{
936 		.cmd = L2TP_CMD_SESSION_GET,
937 		.doit = l2tp_nl_cmd_session_get,
938 		.dumpit = l2tp_nl_cmd_session_dump,
939 		.policy = l2tp_nl_policy,
940 		.flags = GENL_ADMIN_PERM,
941 	},
942 };
943 
944 int l2tp_nl_register_ops(enum l2tp_pwtype pw_type, const struct l2tp_nl_cmd_ops *ops)
945 {
946 	int ret;
947 
948 	ret = -EINVAL;
949 	if (pw_type >= __L2TP_PWTYPE_MAX)
950 		goto err;
951 
952 	genl_lock();
953 	ret = -EBUSY;
954 	if (l2tp_nl_cmd_ops[pw_type])
955 		goto out;
956 
957 	l2tp_nl_cmd_ops[pw_type] = ops;
958 	ret = 0;
959 
960 out:
961 	genl_unlock();
962 err:
963 	return ret;
964 }
965 EXPORT_SYMBOL_GPL(l2tp_nl_register_ops);
966 
967 void l2tp_nl_unregister_ops(enum l2tp_pwtype pw_type)
968 {
969 	if (pw_type < __L2TP_PWTYPE_MAX) {
970 		genl_lock();
971 		l2tp_nl_cmd_ops[pw_type] = NULL;
972 		genl_unlock();
973 	}
974 }
975 EXPORT_SYMBOL_GPL(l2tp_nl_unregister_ops);
976 
977 static int l2tp_nl_init(void)
978 {
979 	pr_info("L2TP netlink interface\n");
980 	return genl_register_family_with_ops_groups(&l2tp_nl_family,
981 						    l2tp_nl_ops,
982 						    l2tp_multicast_group);
983 }
984 
985 static void l2tp_nl_cleanup(void)
986 {
987 	genl_unregister_family(&l2tp_nl_family);
988 }
989 
990 module_init(l2tp_nl_init);
991 module_exit(l2tp_nl_cleanup);
992 
993 MODULE_AUTHOR("James Chapman <jchapman@katalix.com>");
994 MODULE_DESCRIPTION("L2TP netlink");
995 MODULE_LICENSE("GPL");
996 MODULE_VERSION("1.0");
997 MODULE_ALIAS_GENL_FAMILY("l2tp");
998