xref: /openbmc/linux/net/l2tp/l2tp_netlink.c (revision 94cdda6b)
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_in_addr(
209 				info->attrs[L2TP_ATTR_IP_SADDR]);
210 			cfg.peer_ip.s_addr = nla_get_in_addr(
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_in6_addr(skb, L2TP_ATTR_IP6_SADDR,
380 					     &np->saddr) ||
381 			    nla_put_in6_addr(skb, L2TP_ATTR_IP6_DADDR,
382 					     &sk->sk_v6_daddr))
383 				goto nla_put_failure;
384 		} else
385 #endif
386 		if (nla_put_in_addr(skb, L2TP_ATTR_IP_SADDR,
387 				    inet->inet_saddr) ||
388 		    nla_put_in_addr(skb, L2TP_ATTR_IP_DADDR,
389 				    inet->inet_daddr))
390 			goto nla_put_failure;
391 		break;
392 	}
393 
394 out:
395 	genlmsg_end(skb, hdr);
396 	return 0;
397 
398 nla_put_failure:
399 	genlmsg_cancel(skb, hdr);
400 	return -1;
401 }
402 
403 static int l2tp_nl_cmd_tunnel_get(struct sk_buff *skb, struct genl_info *info)
404 {
405 	struct l2tp_tunnel *tunnel;
406 	struct sk_buff *msg;
407 	u32 tunnel_id;
408 	int ret = -ENOBUFS;
409 	struct net *net = genl_info_net(info);
410 
411 	if (!info->attrs[L2TP_ATTR_CONN_ID]) {
412 		ret = -EINVAL;
413 		goto out;
414 	}
415 
416 	tunnel_id = nla_get_u32(info->attrs[L2TP_ATTR_CONN_ID]);
417 
418 	tunnel = l2tp_tunnel_find(net, tunnel_id);
419 	if (tunnel == NULL) {
420 		ret = -ENODEV;
421 		goto out;
422 	}
423 
424 	msg = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);
425 	if (!msg) {
426 		ret = -ENOMEM;
427 		goto out;
428 	}
429 
430 	ret = l2tp_nl_tunnel_send(msg, info->snd_portid, info->snd_seq,
431 				  NLM_F_ACK, tunnel, L2TP_CMD_TUNNEL_GET);
432 	if (ret < 0)
433 		goto err_out;
434 
435 	return genlmsg_unicast(net, msg, info->snd_portid);
436 
437 err_out:
438 	nlmsg_free(msg);
439 
440 out:
441 	return ret;
442 }
443 
444 static int l2tp_nl_cmd_tunnel_dump(struct sk_buff *skb, struct netlink_callback *cb)
445 {
446 	int ti = cb->args[0];
447 	struct l2tp_tunnel *tunnel;
448 	struct net *net = sock_net(skb->sk);
449 
450 	for (;;) {
451 		tunnel = l2tp_tunnel_find_nth(net, ti);
452 		if (tunnel == NULL)
453 			goto out;
454 
455 		if (l2tp_nl_tunnel_send(skb, NETLINK_CB(cb->skb).portid,
456 					cb->nlh->nlmsg_seq, NLM_F_MULTI,
457 					tunnel, L2TP_CMD_TUNNEL_GET) < 0)
458 			goto out;
459 
460 		ti++;
461 	}
462 
463 out:
464 	cb->args[0] = ti;
465 
466 	return skb->len;
467 }
468 
469 static int l2tp_nl_cmd_session_create(struct sk_buff *skb, struct genl_info *info)
470 {
471 	u32 tunnel_id = 0;
472 	u32 session_id;
473 	u32 peer_session_id;
474 	int ret = 0;
475 	struct l2tp_tunnel *tunnel;
476 	struct l2tp_session *session;
477 	struct l2tp_session_cfg cfg = { 0, };
478 	struct net *net = genl_info_net(info);
479 
480 	if (!info->attrs[L2TP_ATTR_CONN_ID]) {
481 		ret = -EINVAL;
482 		goto out;
483 	}
484 	tunnel_id = nla_get_u32(info->attrs[L2TP_ATTR_CONN_ID]);
485 	tunnel = l2tp_tunnel_find(net, tunnel_id);
486 	if (!tunnel) {
487 		ret = -ENODEV;
488 		goto out;
489 	}
490 
491 	if (!info->attrs[L2TP_ATTR_SESSION_ID]) {
492 		ret = -EINVAL;
493 		goto out;
494 	}
495 	session_id = nla_get_u32(info->attrs[L2TP_ATTR_SESSION_ID]);
496 	session = l2tp_session_find(net, tunnel, session_id);
497 	if (session) {
498 		ret = -EEXIST;
499 		goto out;
500 	}
501 
502 	if (!info->attrs[L2TP_ATTR_PEER_SESSION_ID]) {
503 		ret = -EINVAL;
504 		goto out;
505 	}
506 	peer_session_id = nla_get_u32(info->attrs[L2TP_ATTR_PEER_SESSION_ID]);
507 
508 	if (!info->attrs[L2TP_ATTR_PW_TYPE]) {
509 		ret = -EINVAL;
510 		goto out;
511 	}
512 	cfg.pw_type = nla_get_u16(info->attrs[L2TP_ATTR_PW_TYPE]);
513 	if (cfg.pw_type >= __L2TP_PWTYPE_MAX) {
514 		ret = -EINVAL;
515 		goto out;
516 	}
517 
518 	if (tunnel->version > 2) {
519 		if (info->attrs[L2TP_ATTR_OFFSET])
520 			cfg.offset = nla_get_u16(info->attrs[L2TP_ATTR_OFFSET]);
521 
522 		if (info->attrs[L2TP_ATTR_DATA_SEQ])
523 			cfg.data_seq = nla_get_u8(info->attrs[L2TP_ATTR_DATA_SEQ]);
524 
525 		cfg.l2specific_type = L2TP_L2SPECTYPE_DEFAULT;
526 		if (info->attrs[L2TP_ATTR_L2SPEC_TYPE])
527 			cfg.l2specific_type = nla_get_u8(info->attrs[L2TP_ATTR_L2SPEC_TYPE]);
528 
529 		cfg.l2specific_len = 4;
530 		if (info->attrs[L2TP_ATTR_L2SPEC_LEN])
531 			cfg.l2specific_len = nla_get_u8(info->attrs[L2TP_ATTR_L2SPEC_LEN]);
532 
533 		if (info->attrs[L2TP_ATTR_COOKIE]) {
534 			u16 len = nla_len(info->attrs[L2TP_ATTR_COOKIE]);
535 			if (len > 8) {
536 				ret = -EINVAL;
537 				goto out;
538 			}
539 			cfg.cookie_len = len;
540 			memcpy(&cfg.cookie[0], nla_data(info->attrs[L2TP_ATTR_COOKIE]), len);
541 		}
542 		if (info->attrs[L2TP_ATTR_PEER_COOKIE]) {
543 			u16 len = nla_len(info->attrs[L2TP_ATTR_PEER_COOKIE]);
544 			if (len > 8) {
545 				ret = -EINVAL;
546 				goto out;
547 			}
548 			cfg.peer_cookie_len = len;
549 			memcpy(&cfg.peer_cookie[0], nla_data(info->attrs[L2TP_ATTR_PEER_COOKIE]), len);
550 		}
551 		if (info->attrs[L2TP_ATTR_IFNAME])
552 			cfg.ifname = nla_data(info->attrs[L2TP_ATTR_IFNAME]);
553 
554 		if (info->attrs[L2TP_ATTR_VLAN_ID])
555 			cfg.vlan_id = nla_get_u16(info->attrs[L2TP_ATTR_VLAN_ID]);
556 	}
557 
558 	if (info->attrs[L2TP_ATTR_DEBUG])
559 		cfg.debug = nla_get_u32(info->attrs[L2TP_ATTR_DEBUG]);
560 
561 	if (info->attrs[L2TP_ATTR_RECV_SEQ])
562 		cfg.recv_seq = nla_get_u8(info->attrs[L2TP_ATTR_RECV_SEQ]);
563 
564 	if (info->attrs[L2TP_ATTR_SEND_SEQ])
565 		cfg.send_seq = nla_get_u8(info->attrs[L2TP_ATTR_SEND_SEQ]);
566 
567 	if (info->attrs[L2TP_ATTR_LNS_MODE])
568 		cfg.lns_mode = nla_get_u8(info->attrs[L2TP_ATTR_LNS_MODE]);
569 
570 	if (info->attrs[L2TP_ATTR_RECV_TIMEOUT])
571 		cfg.reorder_timeout = nla_get_msecs(info->attrs[L2TP_ATTR_RECV_TIMEOUT]);
572 
573 	if (info->attrs[L2TP_ATTR_MTU])
574 		cfg.mtu = nla_get_u16(info->attrs[L2TP_ATTR_MTU]);
575 
576 	if (info->attrs[L2TP_ATTR_MRU])
577 		cfg.mru = nla_get_u16(info->attrs[L2TP_ATTR_MRU]);
578 
579 	if ((l2tp_nl_cmd_ops[cfg.pw_type] == NULL) ||
580 	    (l2tp_nl_cmd_ops[cfg.pw_type]->session_create == NULL)) {
581 		ret = -EPROTONOSUPPORT;
582 		goto out;
583 	}
584 
585 	/* Check that pseudowire-specific params are present */
586 	switch (cfg.pw_type) {
587 	case L2TP_PWTYPE_NONE:
588 		break;
589 	case L2TP_PWTYPE_ETH_VLAN:
590 		if (!info->attrs[L2TP_ATTR_VLAN_ID]) {
591 			ret = -EINVAL;
592 			goto out;
593 		}
594 		break;
595 	case L2TP_PWTYPE_ETH:
596 		break;
597 	case L2TP_PWTYPE_PPP:
598 	case L2TP_PWTYPE_PPP_AC:
599 		break;
600 	case L2TP_PWTYPE_IP:
601 	default:
602 		ret = -EPROTONOSUPPORT;
603 		break;
604 	}
605 
606 	ret = -EPROTONOSUPPORT;
607 	if (l2tp_nl_cmd_ops[cfg.pw_type]->session_create)
608 		ret = (*l2tp_nl_cmd_ops[cfg.pw_type]->session_create)(net, tunnel_id,
609 			session_id, peer_session_id, &cfg);
610 
611 	if (ret >= 0) {
612 		session = l2tp_session_find(net, tunnel, session_id);
613 		if (session)
614 			ret = l2tp_session_notify(&l2tp_nl_family, info, session,
615 						  L2TP_CMD_SESSION_CREATE);
616 	}
617 
618 out:
619 	return ret;
620 }
621 
622 static int l2tp_nl_cmd_session_delete(struct sk_buff *skb, struct genl_info *info)
623 {
624 	int ret = 0;
625 	struct l2tp_session *session;
626 	u16 pw_type;
627 
628 	session = l2tp_nl_session_find(info);
629 	if (session == NULL) {
630 		ret = -ENODEV;
631 		goto out;
632 	}
633 
634 	l2tp_session_notify(&l2tp_nl_family, info,
635 			    session, L2TP_CMD_SESSION_DELETE);
636 
637 	pw_type = session->pwtype;
638 	if (pw_type < __L2TP_PWTYPE_MAX)
639 		if (l2tp_nl_cmd_ops[pw_type] && l2tp_nl_cmd_ops[pw_type]->session_delete)
640 			ret = (*l2tp_nl_cmd_ops[pw_type]->session_delete)(session);
641 
642 out:
643 	return ret;
644 }
645 
646 static int l2tp_nl_cmd_session_modify(struct sk_buff *skb, struct genl_info *info)
647 {
648 	int ret = 0;
649 	struct l2tp_session *session;
650 
651 	session = l2tp_nl_session_find(info);
652 	if (session == NULL) {
653 		ret = -ENODEV;
654 		goto out;
655 	}
656 
657 	if (info->attrs[L2TP_ATTR_DEBUG])
658 		session->debug = nla_get_u32(info->attrs[L2TP_ATTR_DEBUG]);
659 
660 	if (info->attrs[L2TP_ATTR_DATA_SEQ])
661 		session->data_seq = nla_get_u8(info->attrs[L2TP_ATTR_DATA_SEQ]);
662 
663 	if (info->attrs[L2TP_ATTR_RECV_SEQ])
664 		session->recv_seq = nla_get_u8(info->attrs[L2TP_ATTR_RECV_SEQ]);
665 
666 	if (info->attrs[L2TP_ATTR_SEND_SEQ]) {
667 		session->send_seq = nla_get_u8(info->attrs[L2TP_ATTR_SEND_SEQ]);
668 		l2tp_session_set_header_len(session, session->tunnel->version);
669 	}
670 
671 	if (info->attrs[L2TP_ATTR_LNS_MODE])
672 		session->lns_mode = nla_get_u8(info->attrs[L2TP_ATTR_LNS_MODE]);
673 
674 	if (info->attrs[L2TP_ATTR_RECV_TIMEOUT])
675 		session->reorder_timeout = nla_get_msecs(info->attrs[L2TP_ATTR_RECV_TIMEOUT]);
676 
677 	if (info->attrs[L2TP_ATTR_MTU])
678 		session->mtu = nla_get_u16(info->attrs[L2TP_ATTR_MTU]);
679 
680 	if (info->attrs[L2TP_ATTR_MRU])
681 		session->mru = nla_get_u16(info->attrs[L2TP_ATTR_MRU]);
682 
683 	ret = l2tp_session_notify(&l2tp_nl_family, info,
684 				  session, L2TP_CMD_SESSION_MODIFY);
685 
686 out:
687 	return ret;
688 }
689 
690 static int l2tp_nl_session_send(struct sk_buff *skb, u32 portid, u32 seq, int flags,
691 				struct l2tp_session *session, u8 cmd)
692 {
693 	void *hdr;
694 	struct nlattr *nest;
695 	struct l2tp_tunnel *tunnel = session->tunnel;
696 	struct sock *sk = NULL;
697 
698 	sk = tunnel->sock;
699 
700 	hdr = genlmsg_put(skb, portid, seq, &l2tp_nl_family, flags, cmd);
701 	if (!hdr)
702 		return -EMSGSIZE;
703 
704 	if (nla_put_u32(skb, L2TP_ATTR_CONN_ID, tunnel->tunnel_id) ||
705 	    nla_put_u32(skb, L2TP_ATTR_SESSION_ID, session->session_id) ||
706 	    nla_put_u32(skb, L2TP_ATTR_PEER_CONN_ID, tunnel->peer_tunnel_id) ||
707 	    nla_put_u32(skb, L2TP_ATTR_PEER_SESSION_ID,
708 			session->peer_session_id) ||
709 	    nla_put_u32(skb, L2TP_ATTR_DEBUG, session->debug) ||
710 	    nla_put_u16(skb, L2TP_ATTR_PW_TYPE, session->pwtype) ||
711 	    nla_put_u16(skb, L2TP_ATTR_MTU, session->mtu) ||
712 	    (session->mru &&
713 	     nla_put_u16(skb, L2TP_ATTR_MRU, session->mru)))
714 		goto nla_put_failure;
715 
716 	if ((session->ifname[0] &&
717 	     nla_put_string(skb, L2TP_ATTR_IFNAME, session->ifname)) ||
718 	    (session->cookie_len &&
719 	     nla_put(skb, L2TP_ATTR_COOKIE, session->cookie_len,
720 		     &session->cookie[0])) ||
721 	    (session->peer_cookie_len &&
722 	     nla_put(skb, L2TP_ATTR_PEER_COOKIE, session->peer_cookie_len,
723 		     &session->peer_cookie[0])) ||
724 	    nla_put_u8(skb, L2TP_ATTR_RECV_SEQ, session->recv_seq) ||
725 	    nla_put_u8(skb, L2TP_ATTR_SEND_SEQ, session->send_seq) ||
726 	    nla_put_u8(skb, L2TP_ATTR_LNS_MODE, session->lns_mode) ||
727 #ifdef CONFIG_XFRM
728 	    (((sk) && (sk->sk_policy[0] || sk->sk_policy[1])) &&
729 	     nla_put_u8(skb, L2TP_ATTR_USING_IPSEC, 1)) ||
730 #endif
731 	    (session->reorder_timeout &&
732 	     nla_put_msecs(skb, L2TP_ATTR_RECV_TIMEOUT, session->reorder_timeout)))
733 		goto nla_put_failure;
734 
735 	nest = nla_nest_start(skb, L2TP_ATTR_STATS);
736 	if (nest == NULL)
737 		goto nla_put_failure;
738 
739 	if (nla_put_u64(skb, L2TP_ATTR_TX_PACKETS,
740 		atomic_long_read(&session->stats.tx_packets)) ||
741 	    nla_put_u64(skb, L2TP_ATTR_TX_BYTES,
742 		atomic_long_read(&session->stats.tx_bytes)) ||
743 	    nla_put_u64(skb, L2TP_ATTR_TX_ERRORS,
744 		atomic_long_read(&session->stats.tx_errors)) ||
745 	    nla_put_u64(skb, L2TP_ATTR_RX_PACKETS,
746 		atomic_long_read(&session->stats.rx_packets)) ||
747 	    nla_put_u64(skb, L2TP_ATTR_RX_BYTES,
748 		atomic_long_read(&session->stats.rx_bytes)) ||
749 	    nla_put_u64(skb, L2TP_ATTR_RX_SEQ_DISCARDS,
750 		atomic_long_read(&session->stats.rx_seq_discards)) ||
751 	    nla_put_u64(skb, L2TP_ATTR_RX_OOS_PACKETS,
752 		atomic_long_read(&session->stats.rx_oos_packets)) ||
753 	    nla_put_u64(skb, L2TP_ATTR_RX_ERRORS,
754 		atomic_long_read(&session->stats.rx_errors)))
755 		goto nla_put_failure;
756 	nla_nest_end(skb, nest);
757 
758 	genlmsg_end(skb, hdr);
759 	return 0;
760 
761  nla_put_failure:
762 	genlmsg_cancel(skb, hdr);
763 	return -1;
764 }
765 
766 static int l2tp_nl_cmd_session_get(struct sk_buff *skb, struct genl_info *info)
767 {
768 	struct l2tp_session *session;
769 	struct sk_buff *msg;
770 	int ret;
771 
772 	session = l2tp_nl_session_find(info);
773 	if (session == NULL) {
774 		ret = -ENODEV;
775 		goto out;
776 	}
777 
778 	msg = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);
779 	if (!msg) {
780 		ret = -ENOMEM;
781 		goto out;
782 	}
783 
784 	ret = l2tp_nl_session_send(msg, info->snd_portid, info->snd_seq,
785 				   0, session, L2TP_CMD_SESSION_GET);
786 	if (ret < 0)
787 		goto err_out;
788 
789 	return genlmsg_unicast(genl_info_net(info), msg, info->snd_portid);
790 
791 err_out:
792 	nlmsg_free(msg);
793 
794 out:
795 	return ret;
796 }
797 
798 static int l2tp_nl_cmd_session_dump(struct sk_buff *skb, struct netlink_callback *cb)
799 {
800 	struct net *net = sock_net(skb->sk);
801 	struct l2tp_session *session;
802 	struct l2tp_tunnel *tunnel = NULL;
803 	int ti = cb->args[0];
804 	int si = cb->args[1];
805 
806 	for (;;) {
807 		if (tunnel == NULL) {
808 			tunnel = l2tp_tunnel_find_nth(net, ti);
809 			if (tunnel == NULL)
810 				goto out;
811 		}
812 
813 		session = l2tp_session_find_nth(tunnel, si);
814 		if (session == NULL) {
815 			ti++;
816 			tunnel = NULL;
817 			si = 0;
818 			continue;
819 		}
820 
821 		if (l2tp_nl_session_send(skb, NETLINK_CB(cb->skb).portid,
822 					 cb->nlh->nlmsg_seq, NLM_F_MULTI,
823 					 session, L2TP_CMD_SESSION_GET) < 0)
824 			break;
825 
826 		si++;
827 	}
828 
829 out:
830 	cb->args[0] = ti;
831 	cb->args[1] = si;
832 
833 	return skb->len;
834 }
835 
836 static struct nla_policy l2tp_nl_policy[L2TP_ATTR_MAX + 1] = {
837 	[L2TP_ATTR_NONE]		= { .type = NLA_UNSPEC, },
838 	[L2TP_ATTR_PW_TYPE]		= { .type = NLA_U16, },
839 	[L2TP_ATTR_ENCAP_TYPE]		= { .type = NLA_U16, },
840 	[L2TP_ATTR_OFFSET]		= { .type = NLA_U16, },
841 	[L2TP_ATTR_DATA_SEQ]		= { .type = NLA_U8, },
842 	[L2TP_ATTR_L2SPEC_TYPE]		= { .type = NLA_U8, },
843 	[L2TP_ATTR_L2SPEC_LEN]		= { .type = NLA_U8, },
844 	[L2TP_ATTR_PROTO_VERSION]	= { .type = NLA_U8, },
845 	[L2TP_ATTR_CONN_ID]		= { .type = NLA_U32, },
846 	[L2TP_ATTR_PEER_CONN_ID]	= { .type = NLA_U32, },
847 	[L2TP_ATTR_SESSION_ID]		= { .type = NLA_U32, },
848 	[L2TP_ATTR_PEER_SESSION_ID]	= { .type = NLA_U32, },
849 	[L2TP_ATTR_UDP_CSUM]		= { .type = NLA_U8, },
850 	[L2TP_ATTR_VLAN_ID]		= { .type = NLA_U16, },
851 	[L2TP_ATTR_DEBUG]		= { .type = NLA_U32, },
852 	[L2TP_ATTR_RECV_SEQ]		= { .type = NLA_U8, },
853 	[L2TP_ATTR_SEND_SEQ]		= { .type = NLA_U8, },
854 	[L2TP_ATTR_LNS_MODE]		= { .type = NLA_U8, },
855 	[L2TP_ATTR_USING_IPSEC]		= { .type = NLA_U8, },
856 	[L2TP_ATTR_RECV_TIMEOUT]	= { .type = NLA_MSECS, },
857 	[L2TP_ATTR_FD]			= { .type = NLA_U32, },
858 	[L2TP_ATTR_IP_SADDR]		= { .type = NLA_U32, },
859 	[L2TP_ATTR_IP_DADDR]		= { .type = NLA_U32, },
860 	[L2TP_ATTR_UDP_SPORT]		= { .type = NLA_U16, },
861 	[L2TP_ATTR_UDP_DPORT]		= { .type = NLA_U16, },
862 	[L2TP_ATTR_MTU]			= { .type = NLA_U16, },
863 	[L2TP_ATTR_MRU]			= { .type = NLA_U16, },
864 	[L2TP_ATTR_STATS]		= { .type = NLA_NESTED, },
865 	[L2TP_ATTR_IP6_SADDR] = {
866 		.type = NLA_BINARY,
867 		.len = sizeof(struct in6_addr),
868 	},
869 	[L2TP_ATTR_IP6_DADDR] = {
870 		.type = NLA_BINARY,
871 		.len = sizeof(struct in6_addr),
872 	},
873 	[L2TP_ATTR_IFNAME] = {
874 		.type = NLA_NUL_STRING,
875 		.len = IFNAMSIZ - 1,
876 	},
877 	[L2TP_ATTR_COOKIE] = {
878 		.type = NLA_BINARY,
879 		.len = 8,
880 	},
881 	[L2TP_ATTR_PEER_COOKIE] = {
882 		.type = NLA_BINARY,
883 		.len = 8,
884 	},
885 };
886 
887 static const struct genl_ops l2tp_nl_ops[] = {
888 	{
889 		.cmd = L2TP_CMD_NOOP,
890 		.doit = l2tp_nl_cmd_noop,
891 		.policy = l2tp_nl_policy,
892 		/* can be retrieved by unprivileged users */
893 	},
894 	{
895 		.cmd = L2TP_CMD_TUNNEL_CREATE,
896 		.doit = l2tp_nl_cmd_tunnel_create,
897 		.policy = l2tp_nl_policy,
898 		.flags = GENL_ADMIN_PERM,
899 	},
900 	{
901 		.cmd = L2TP_CMD_TUNNEL_DELETE,
902 		.doit = l2tp_nl_cmd_tunnel_delete,
903 		.policy = l2tp_nl_policy,
904 		.flags = GENL_ADMIN_PERM,
905 	},
906 	{
907 		.cmd = L2TP_CMD_TUNNEL_MODIFY,
908 		.doit = l2tp_nl_cmd_tunnel_modify,
909 		.policy = l2tp_nl_policy,
910 		.flags = GENL_ADMIN_PERM,
911 	},
912 	{
913 		.cmd = L2TP_CMD_TUNNEL_GET,
914 		.doit = l2tp_nl_cmd_tunnel_get,
915 		.dumpit = l2tp_nl_cmd_tunnel_dump,
916 		.policy = l2tp_nl_policy,
917 		.flags = GENL_ADMIN_PERM,
918 	},
919 	{
920 		.cmd = L2TP_CMD_SESSION_CREATE,
921 		.doit = l2tp_nl_cmd_session_create,
922 		.policy = l2tp_nl_policy,
923 		.flags = GENL_ADMIN_PERM,
924 	},
925 	{
926 		.cmd = L2TP_CMD_SESSION_DELETE,
927 		.doit = l2tp_nl_cmd_session_delete,
928 		.policy = l2tp_nl_policy,
929 		.flags = GENL_ADMIN_PERM,
930 	},
931 	{
932 		.cmd = L2TP_CMD_SESSION_MODIFY,
933 		.doit = l2tp_nl_cmd_session_modify,
934 		.policy = l2tp_nl_policy,
935 		.flags = GENL_ADMIN_PERM,
936 	},
937 	{
938 		.cmd = L2TP_CMD_SESSION_GET,
939 		.doit = l2tp_nl_cmd_session_get,
940 		.dumpit = l2tp_nl_cmd_session_dump,
941 		.policy = l2tp_nl_policy,
942 		.flags = GENL_ADMIN_PERM,
943 	},
944 };
945 
946 int l2tp_nl_register_ops(enum l2tp_pwtype pw_type, const struct l2tp_nl_cmd_ops *ops)
947 {
948 	int ret;
949 
950 	ret = -EINVAL;
951 	if (pw_type >= __L2TP_PWTYPE_MAX)
952 		goto err;
953 
954 	genl_lock();
955 	ret = -EBUSY;
956 	if (l2tp_nl_cmd_ops[pw_type])
957 		goto out;
958 
959 	l2tp_nl_cmd_ops[pw_type] = ops;
960 	ret = 0;
961 
962 out:
963 	genl_unlock();
964 err:
965 	return ret;
966 }
967 EXPORT_SYMBOL_GPL(l2tp_nl_register_ops);
968 
969 void l2tp_nl_unregister_ops(enum l2tp_pwtype pw_type)
970 {
971 	if (pw_type < __L2TP_PWTYPE_MAX) {
972 		genl_lock();
973 		l2tp_nl_cmd_ops[pw_type] = NULL;
974 		genl_unlock();
975 	}
976 }
977 EXPORT_SYMBOL_GPL(l2tp_nl_unregister_ops);
978 
979 static int l2tp_nl_init(void)
980 {
981 	pr_info("L2TP netlink interface\n");
982 	return genl_register_family_with_ops_groups(&l2tp_nl_family,
983 						    l2tp_nl_ops,
984 						    l2tp_multicast_group);
985 }
986 
987 static void l2tp_nl_cleanup(void)
988 {
989 	genl_unregister_family(&l2tp_nl_family);
990 }
991 
992 module_init(l2tp_nl_init);
993 module_exit(l2tp_nl_cleanup);
994 
995 MODULE_AUTHOR("James Chapman <jchapman@katalix.com>");
996 MODULE_DESCRIPTION("L2TP netlink");
997 MODULE_LICENSE("GPL");
998 MODULE_VERSION("1.0");
999 MODULE_ALIAS_GENL_FAMILY("l2tp");
1000