xref: /openbmc/linux/net/l2tp/l2tp_netlink.c (revision 4f6cce39)
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 
36 static const struct genl_multicast_group l2tp_multicast_group[] = {
37 	{
38 		.name = L2TP_GENL_MCGROUP,
39 	},
40 };
41 
42 static int l2tp_nl_tunnel_send(struct sk_buff *skb, u32 portid, u32 seq,
43 			       int flags, struct l2tp_tunnel *tunnel, u8 cmd);
44 static int l2tp_nl_session_send(struct sk_buff *skb, u32 portid, u32 seq,
45 				int flags, struct l2tp_session *session,
46 				u8 cmd);
47 
48 /* Accessed under genl lock */
49 static const struct l2tp_nl_cmd_ops *l2tp_nl_cmd_ops[__L2TP_PWTYPE_MAX];
50 
51 static struct l2tp_session *l2tp_nl_session_find(struct genl_info *info)
52 {
53 	u32 tunnel_id;
54 	u32 session_id;
55 	char *ifname;
56 	struct l2tp_tunnel *tunnel;
57 	struct l2tp_session *session = NULL;
58 	struct net *net = genl_info_net(info);
59 
60 	if (info->attrs[L2TP_ATTR_IFNAME]) {
61 		ifname = nla_data(info->attrs[L2TP_ATTR_IFNAME]);
62 		session = l2tp_session_find_by_ifname(net, ifname);
63 	} else if ((info->attrs[L2TP_ATTR_SESSION_ID]) &&
64 		   (info->attrs[L2TP_ATTR_CONN_ID])) {
65 		tunnel_id = nla_get_u32(info->attrs[L2TP_ATTR_CONN_ID]);
66 		session_id = nla_get_u32(info->attrs[L2TP_ATTR_SESSION_ID]);
67 		tunnel = l2tp_tunnel_find(net, tunnel_id);
68 		if (tunnel)
69 			session = l2tp_session_find(net, tunnel, session_id);
70 	}
71 
72 	return session;
73 }
74 
75 static int l2tp_nl_cmd_noop(struct sk_buff *skb, struct genl_info *info)
76 {
77 	struct sk_buff *msg;
78 	void *hdr;
79 	int ret = -ENOBUFS;
80 
81 	msg = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);
82 	if (!msg) {
83 		ret = -ENOMEM;
84 		goto out;
85 	}
86 
87 	hdr = genlmsg_put(msg, info->snd_portid, info->snd_seq,
88 			  &l2tp_nl_family, 0, L2TP_CMD_NOOP);
89 	if (!hdr) {
90 		ret = -EMSGSIZE;
91 		goto err_out;
92 	}
93 
94 	genlmsg_end(msg, hdr);
95 
96 	return genlmsg_unicast(genl_info_net(info), msg, info->snd_portid);
97 
98 err_out:
99 	nlmsg_free(msg);
100 
101 out:
102 	return ret;
103 }
104 
105 static int l2tp_tunnel_notify(struct genl_family *family,
106 			      struct genl_info *info,
107 			      struct l2tp_tunnel *tunnel,
108 			      u8 cmd)
109 {
110 	struct sk_buff *msg;
111 	int ret;
112 
113 	msg = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);
114 	if (!msg)
115 		return -ENOMEM;
116 
117 	ret = l2tp_nl_tunnel_send(msg, info->snd_portid, info->snd_seq,
118 				  NLM_F_ACK, tunnel, cmd);
119 
120 	if (ret >= 0) {
121 		ret = genlmsg_multicast_allns(family, msg, 0, 0, GFP_ATOMIC);
122 		/* We don't care if no one is listening */
123 		if (ret == -ESRCH)
124 			ret = 0;
125 		return ret;
126 	}
127 
128 	nlmsg_free(msg);
129 
130 	return ret;
131 }
132 
133 static int l2tp_session_notify(struct genl_family *family,
134 			       struct genl_info *info,
135 			       struct l2tp_session *session,
136 			       u8 cmd)
137 {
138 	struct sk_buff *msg;
139 	int ret;
140 
141 	msg = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);
142 	if (!msg)
143 		return -ENOMEM;
144 
145 	ret = l2tp_nl_session_send(msg, info->snd_portid, info->snd_seq,
146 				   NLM_F_ACK, session, cmd);
147 
148 	if (ret >= 0) {
149 		ret = genlmsg_multicast_allns(family, msg, 0, 0, GFP_ATOMIC);
150 		/* We don't care if no one is listening */
151 		if (ret == -ESRCH)
152 			ret = 0;
153 		return ret;
154 	}
155 
156 	nlmsg_free(msg);
157 
158 	return ret;
159 }
160 
161 static int l2tp_nl_cmd_tunnel_create(struct sk_buff *skb, struct genl_info *info)
162 {
163 	u32 tunnel_id;
164 	u32 peer_tunnel_id;
165 	int proto_version;
166 	int fd;
167 	int ret = 0;
168 	struct l2tp_tunnel_cfg cfg = { 0, };
169 	struct l2tp_tunnel *tunnel;
170 	struct net *net = genl_info_net(info);
171 
172 	if (!info->attrs[L2TP_ATTR_CONN_ID]) {
173 		ret = -EINVAL;
174 		goto out;
175 	}
176 	tunnel_id = nla_get_u32(info->attrs[L2TP_ATTR_CONN_ID]);
177 
178 	if (!info->attrs[L2TP_ATTR_PEER_CONN_ID]) {
179 		ret = -EINVAL;
180 		goto out;
181 	}
182 	peer_tunnel_id = nla_get_u32(info->attrs[L2TP_ATTR_PEER_CONN_ID]);
183 
184 	if (!info->attrs[L2TP_ATTR_PROTO_VERSION]) {
185 		ret = -EINVAL;
186 		goto out;
187 	}
188 	proto_version = nla_get_u8(info->attrs[L2TP_ATTR_PROTO_VERSION]);
189 
190 	if (!info->attrs[L2TP_ATTR_ENCAP_TYPE]) {
191 		ret = -EINVAL;
192 		goto out;
193 	}
194 	cfg.encap = nla_get_u16(info->attrs[L2TP_ATTR_ENCAP_TYPE]);
195 
196 	fd = -1;
197 	if (info->attrs[L2TP_ATTR_FD]) {
198 		fd = nla_get_u32(info->attrs[L2TP_ATTR_FD]);
199 	} else {
200 #if IS_ENABLED(CONFIG_IPV6)
201 		if (info->attrs[L2TP_ATTR_IP6_SADDR] &&
202 		    info->attrs[L2TP_ATTR_IP6_DADDR]) {
203 			cfg.local_ip6 = nla_data(
204 				info->attrs[L2TP_ATTR_IP6_SADDR]);
205 			cfg.peer_ip6 = nla_data(
206 				info->attrs[L2TP_ATTR_IP6_DADDR]);
207 		} else
208 #endif
209 		if (info->attrs[L2TP_ATTR_IP_SADDR] &&
210 		    info->attrs[L2TP_ATTR_IP_DADDR]) {
211 			cfg.local_ip.s_addr = nla_get_in_addr(
212 				info->attrs[L2TP_ATTR_IP_SADDR]);
213 			cfg.peer_ip.s_addr = nla_get_in_addr(
214 				info->attrs[L2TP_ATTR_IP_DADDR]);
215 		} else {
216 			ret = -EINVAL;
217 			goto out;
218 		}
219 		if (info->attrs[L2TP_ATTR_UDP_SPORT])
220 			cfg.local_udp_port = nla_get_u16(info->attrs[L2TP_ATTR_UDP_SPORT]);
221 		if (info->attrs[L2TP_ATTR_UDP_DPORT])
222 			cfg.peer_udp_port = nla_get_u16(info->attrs[L2TP_ATTR_UDP_DPORT]);
223 		cfg.use_udp_checksums = nla_get_flag(
224 			info->attrs[L2TP_ATTR_UDP_CSUM]);
225 
226 #if IS_ENABLED(CONFIG_IPV6)
227 		cfg.udp6_zero_tx_checksums = nla_get_flag(
228 			info->attrs[L2TP_ATTR_UDP_ZERO_CSUM6_TX]);
229 		cfg.udp6_zero_rx_checksums = nla_get_flag(
230 			info->attrs[L2TP_ATTR_UDP_ZERO_CSUM6_RX]);
231 #endif
232 	}
233 
234 	if (info->attrs[L2TP_ATTR_DEBUG])
235 		cfg.debug = nla_get_u32(info->attrs[L2TP_ATTR_DEBUG]);
236 
237 	tunnel = l2tp_tunnel_find(net, tunnel_id);
238 	if (tunnel != NULL) {
239 		ret = -EEXIST;
240 		goto out;
241 	}
242 
243 	ret = -EINVAL;
244 	switch (cfg.encap) {
245 	case L2TP_ENCAPTYPE_UDP:
246 	case L2TP_ENCAPTYPE_IP:
247 		ret = l2tp_tunnel_create(net, fd, proto_version, tunnel_id,
248 					 peer_tunnel_id, &cfg, &tunnel);
249 		break;
250 	}
251 
252 	if (ret >= 0)
253 		ret = l2tp_tunnel_notify(&l2tp_nl_family, info,
254 					 tunnel, L2TP_CMD_TUNNEL_CREATE);
255 out:
256 	return ret;
257 }
258 
259 static int l2tp_nl_cmd_tunnel_delete(struct sk_buff *skb, struct genl_info *info)
260 {
261 	struct l2tp_tunnel *tunnel;
262 	u32 tunnel_id;
263 	int ret = 0;
264 	struct net *net = genl_info_net(info);
265 
266 	if (!info->attrs[L2TP_ATTR_CONN_ID]) {
267 		ret = -EINVAL;
268 		goto out;
269 	}
270 	tunnel_id = nla_get_u32(info->attrs[L2TP_ATTR_CONN_ID]);
271 
272 	tunnel = l2tp_tunnel_find(net, tunnel_id);
273 	if (tunnel == NULL) {
274 		ret = -ENODEV;
275 		goto out;
276 	}
277 
278 	l2tp_tunnel_notify(&l2tp_nl_family, info,
279 			   tunnel, L2TP_CMD_TUNNEL_DELETE);
280 
281 	(void) l2tp_tunnel_delete(tunnel);
282 
283 out:
284 	return ret;
285 }
286 
287 static int l2tp_nl_cmd_tunnel_modify(struct sk_buff *skb, struct genl_info *info)
288 {
289 	struct l2tp_tunnel *tunnel;
290 	u32 tunnel_id;
291 	int ret = 0;
292 	struct net *net = genl_info_net(info);
293 
294 	if (!info->attrs[L2TP_ATTR_CONN_ID]) {
295 		ret = -EINVAL;
296 		goto out;
297 	}
298 	tunnel_id = nla_get_u32(info->attrs[L2TP_ATTR_CONN_ID]);
299 
300 	tunnel = l2tp_tunnel_find(net, tunnel_id);
301 	if (tunnel == NULL) {
302 		ret = -ENODEV;
303 		goto out;
304 	}
305 
306 	if (info->attrs[L2TP_ATTR_DEBUG])
307 		tunnel->debug = nla_get_u32(info->attrs[L2TP_ATTR_DEBUG]);
308 
309 	ret = l2tp_tunnel_notify(&l2tp_nl_family, info,
310 				 tunnel, L2TP_CMD_TUNNEL_MODIFY);
311 
312 out:
313 	return ret;
314 }
315 
316 static int l2tp_nl_tunnel_send(struct sk_buff *skb, u32 portid, u32 seq, int flags,
317 			       struct l2tp_tunnel *tunnel, u8 cmd)
318 {
319 	void *hdr;
320 	struct nlattr *nest;
321 	struct sock *sk = NULL;
322 	struct inet_sock *inet;
323 #if IS_ENABLED(CONFIG_IPV6)
324 	struct ipv6_pinfo *np = NULL;
325 #endif
326 
327 	hdr = genlmsg_put(skb, portid, seq, &l2tp_nl_family, flags, cmd);
328 	if (!hdr)
329 		return -EMSGSIZE;
330 
331 	if (nla_put_u8(skb, L2TP_ATTR_PROTO_VERSION, tunnel->version) ||
332 	    nla_put_u32(skb, L2TP_ATTR_CONN_ID, tunnel->tunnel_id) ||
333 	    nla_put_u32(skb, L2TP_ATTR_PEER_CONN_ID, tunnel->peer_tunnel_id) ||
334 	    nla_put_u32(skb, L2TP_ATTR_DEBUG, tunnel->debug) ||
335 	    nla_put_u16(skb, L2TP_ATTR_ENCAP_TYPE, tunnel->encap))
336 		goto nla_put_failure;
337 
338 	nest = nla_nest_start(skb, L2TP_ATTR_STATS);
339 	if (nest == NULL)
340 		goto nla_put_failure;
341 
342 	if (nla_put_u64_64bit(skb, L2TP_ATTR_TX_PACKETS,
343 			      atomic_long_read(&tunnel->stats.tx_packets),
344 			      L2TP_ATTR_STATS_PAD) ||
345 	    nla_put_u64_64bit(skb, L2TP_ATTR_TX_BYTES,
346 			      atomic_long_read(&tunnel->stats.tx_bytes),
347 			      L2TP_ATTR_STATS_PAD) ||
348 	    nla_put_u64_64bit(skb, L2TP_ATTR_TX_ERRORS,
349 			      atomic_long_read(&tunnel->stats.tx_errors),
350 			      L2TP_ATTR_STATS_PAD) ||
351 	    nla_put_u64_64bit(skb, L2TP_ATTR_RX_PACKETS,
352 			      atomic_long_read(&tunnel->stats.rx_packets),
353 			      L2TP_ATTR_STATS_PAD) ||
354 	    nla_put_u64_64bit(skb, L2TP_ATTR_RX_BYTES,
355 			      atomic_long_read(&tunnel->stats.rx_bytes),
356 			      L2TP_ATTR_STATS_PAD) ||
357 	    nla_put_u64_64bit(skb, L2TP_ATTR_RX_SEQ_DISCARDS,
358 			      atomic_long_read(&tunnel->stats.rx_seq_discards),
359 			      L2TP_ATTR_STATS_PAD) ||
360 	    nla_put_u64_64bit(skb, L2TP_ATTR_RX_OOS_PACKETS,
361 			      atomic_long_read(&tunnel->stats.rx_oos_packets),
362 			      L2TP_ATTR_STATS_PAD) ||
363 	    nla_put_u64_64bit(skb, L2TP_ATTR_RX_ERRORS,
364 			      atomic_long_read(&tunnel->stats.rx_errors),
365 			      L2TP_ATTR_STATS_PAD))
366 		goto nla_put_failure;
367 	nla_nest_end(skb, nest);
368 
369 	sk = tunnel->sock;
370 	if (!sk)
371 		goto out;
372 
373 #if IS_ENABLED(CONFIG_IPV6)
374 	if (sk->sk_family == AF_INET6)
375 		np = inet6_sk(sk);
376 #endif
377 
378 	inet = inet_sk(sk);
379 
380 	switch (tunnel->encap) {
381 	case L2TP_ENCAPTYPE_UDP:
382 		switch (sk->sk_family) {
383 		case AF_INET:
384 			if (nla_put_u8(skb, L2TP_ATTR_UDP_CSUM, !sk->sk_no_check_tx))
385 				goto nla_put_failure;
386 			break;
387 #if IS_ENABLED(CONFIG_IPV6)
388 		case AF_INET6:
389 			if (udp_get_no_check6_tx(sk) &&
390 			    nla_put_flag(skb, L2TP_ATTR_UDP_ZERO_CSUM6_TX))
391 				goto nla_put_failure;
392 			if (udp_get_no_check6_rx(sk) &&
393 			    nla_put_flag(skb, L2TP_ATTR_UDP_ZERO_CSUM6_RX))
394 				goto nla_put_failure;
395 			break;
396 #endif
397 		}
398 		if (nla_put_u16(skb, L2TP_ATTR_UDP_SPORT, ntohs(inet->inet_sport)) ||
399 		    nla_put_u16(skb, L2TP_ATTR_UDP_DPORT, ntohs(inet->inet_dport)))
400 			goto nla_put_failure;
401 		/* NOBREAK */
402 	case L2TP_ENCAPTYPE_IP:
403 #if IS_ENABLED(CONFIG_IPV6)
404 		if (np) {
405 			if (nla_put_in6_addr(skb, L2TP_ATTR_IP6_SADDR,
406 					     &np->saddr) ||
407 			    nla_put_in6_addr(skb, L2TP_ATTR_IP6_DADDR,
408 					     &sk->sk_v6_daddr))
409 				goto nla_put_failure;
410 		} else
411 #endif
412 		if (nla_put_in_addr(skb, L2TP_ATTR_IP_SADDR,
413 				    inet->inet_saddr) ||
414 		    nla_put_in_addr(skb, L2TP_ATTR_IP_DADDR,
415 				    inet->inet_daddr))
416 			goto nla_put_failure;
417 		break;
418 	}
419 
420 out:
421 	genlmsg_end(skb, hdr);
422 	return 0;
423 
424 nla_put_failure:
425 	genlmsg_cancel(skb, hdr);
426 	return -1;
427 }
428 
429 static int l2tp_nl_cmd_tunnel_get(struct sk_buff *skb, struct genl_info *info)
430 {
431 	struct l2tp_tunnel *tunnel;
432 	struct sk_buff *msg;
433 	u32 tunnel_id;
434 	int ret = -ENOBUFS;
435 	struct net *net = genl_info_net(info);
436 
437 	if (!info->attrs[L2TP_ATTR_CONN_ID]) {
438 		ret = -EINVAL;
439 		goto out;
440 	}
441 
442 	tunnel_id = nla_get_u32(info->attrs[L2TP_ATTR_CONN_ID]);
443 
444 	tunnel = l2tp_tunnel_find(net, tunnel_id);
445 	if (tunnel == NULL) {
446 		ret = -ENODEV;
447 		goto out;
448 	}
449 
450 	msg = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);
451 	if (!msg) {
452 		ret = -ENOMEM;
453 		goto out;
454 	}
455 
456 	ret = l2tp_nl_tunnel_send(msg, info->snd_portid, info->snd_seq,
457 				  NLM_F_ACK, tunnel, L2TP_CMD_TUNNEL_GET);
458 	if (ret < 0)
459 		goto err_out;
460 
461 	return genlmsg_unicast(net, msg, info->snd_portid);
462 
463 err_out:
464 	nlmsg_free(msg);
465 
466 out:
467 	return ret;
468 }
469 
470 static int l2tp_nl_cmd_tunnel_dump(struct sk_buff *skb, struct netlink_callback *cb)
471 {
472 	int ti = cb->args[0];
473 	struct l2tp_tunnel *tunnel;
474 	struct net *net = sock_net(skb->sk);
475 
476 	for (;;) {
477 		tunnel = l2tp_tunnel_find_nth(net, ti);
478 		if (tunnel == NULL)
479 			goto out;
480 
481 		if (l2tp_nl_tunnel_send(skb, NETLINK_CB(cb->skb).portid,
482 					cb->nlh->nlmsg_seq, NLM_F_MULTI,
483 					tunnel, L2TP_CMD_TUNNEL_GET) < 0)
484 			goto out;
485 
486 		ti++;
487 	}
488 
489 out:
490 	cb->args[0] = ti;
491 
492 	return skb->len;
493 }
494 
495 static int l2tp_nl_cmd_session_create(struct sk_buff *skb, struct genl_info *info)
496 {
497 	u32 tunnel_id = 0;
498 	u32 session_id;
499 	u32 peer_session_id;
500 	int ret = 0;
501 	struct l2tp_tunnel *tunnel;
502 	struct l2tp_session *session;
503 	struct l2tp_session_cfg cfg = { 0, };
504 	struct net *net = genl_info_net(info);
505 
506 	if (!info->attrs[L2TP_ATTR_CONN_ID]) {
507 		ret = -EINVAL;
508 		goto out;
509 	}
510 	tunnel_id = nla_get_u32(info->attrs[L2TP_ATTR_CONN_ID]);
511 	tunnel = l2tp_tunnel_find(net, tunnel_id);
512 	if (!tunnel) {
513 		ret = -ENODEV;
514 		goto out;
515 	}
516 
517 	if (!info->attrs[L2TP_ATTR_SESSION_ID]) {
518 		ret = -EINVAL;
519 		goto out;
520 	}
521 	session_id = nla_get_u32(info->attrs[L2TP_ATTR_SESSION_ID]);
522 	session = l2tp_session_find(net, tunnel, session_id);
523 	if (session) {
524 		ret = -EEXIST;
525 		goto out;
526 	}
527 
528 	if (!info->attrs[L2TP_ATTR_PEER_SESSION_ID]) {
529 		ret = -EINVAL;
530 		goto out;
531 	}
532 	peer_session_id = nla_get_u32(info->attrs[L2TP_ATTR_PEER_SESSION_ID]);
533 
534 	if (!info->attrs[L2TP_ATTR_PW_TYPE]) {
535 		ret = -EINVAL;
536 		goto out;
537 	}
538 	cfg.pw_type = nla_get_u16(info->attrs[L2TP_ATTR_PW_TYPE]);
539 	if (cfg.pw_type >= __L2TP_PWTYPE_MAX) {
540 		ret = -EINVAL;
541 		goto out;
542 	}
543 
544 	if (tunnel->version > 2) {
545 		if (info->attrs[L2TP_ATTR_OFFSET])
546 			cfg.offset = nla_get_u16(info->attrs[L2TP_ATTR_OFFSET]);
547 
548 		if (info->attrs[L2TP_ATTR_DATA_SEQ])
549 			cfg.data_seq = nla_get_u8(info->attrs[L2TP_ATTR_DATA_SEQ]);
550 
551 		cfg.l2specific_type = L2TP_L2SPECTYPE_DEFAULT;
552 		if (info->attrs[L2TP_ATTR_L2SPEC_TYPE])
553 			cfg.l2specific_type = nla_get_u8(info->attrs[L2TP_ATTR_L2SPEC_TYPE]);
554 
555 		cfg.l2specific_len = 4;
556 		if (info->attrs[L2TP_ATTR_L2SPEC_LEN])
557 			cfg.l2specific_len = nla_get_u8(info->attrs[L2TP_ATTR_L2SPEC_LEN]);
558 
559 		if (info->attrs[L2TP_ATTR_COOKIE]) {
560 			u16 len = nla_len(info->attrs[L2TP_ATTR_COOKIE]);
561 			if (len > 8) {
562 				ret = -EINVAL;
563 				goto out;
564 			}
565 			cfg.cookie_len = len;
566 			memcpy(&cfg.cookie[0], nla_data(info->attrs[L2TP_ATTR_COOKIE]), len);
567 		}
568 		if (info->attrs[L2TP_ATTR_PEER_COOKIE]) {
569 			u16 len = nla_len(info->attrs[L2TP_ATTR_PEER_COOKIE]);
570 			if (len > 8) {
571 				ret = -EINVAL;
572 				goto out;
573 			}
574 			cfg.peer_cookie_len = len;
575 			memcpy(&cfg.peer_cookie[0], nla_data(info->attrs[L2TP_ATTR_PEER_COOKIE]), len);
576 		}
577 		if (info->attrs[L2TP_ATTR_IFNAME])
578 			cfg.ifname = nla_data(info->attrs[L2TP_ATTR_IFNAME]);
579 
580 		if (info->attrs[L2TP_ATTR_VLAN_ID])
581 			cfg.vlan_id = nla_get_u16(info->attrs[L2TP_ATTR_VLAN_ID]);
582 	}
583 
584 	if (info->attrs[L2TP_ATTR_DEBUG])
585 		cfg.debug = nla_get_u32(info->attrs[L2TP_ATTR_DEBUG]);
586 
587 	if (info->attrs[L2TP_ATTR_RECV_SEQ])
588 		cfg.recv_seq = nla_get_u8(info->attrs[L2TP_ATTR_RECV_SEQ]);
589 
590 	if (info->attrs[L2TP_ATTR_SEND_SEQ])
591 		cfg.send_seq = nla_get_u8(info->attrs[L2TP_ATTR_SEND_SEQ]);
592 
593 	if (info->attrs[L2TP_ATTR_LNS_MODE])
594 		cfg.lns_mode = nla_get_u8(info->attrs[L2TP_ATTR_LNS_MODE]);
595 
596 	if (info->attrs[L2TP_ATTR_RECV_TIMEOUT])
597 		cfg.reorder_timeout = nla_get_msecs(info->attrs[L2TP_ATTR_RECV_TIMEOUT]);
598 
599 	if (info->attrs[L2TP_ATTR_MTU])
600 		cfg.mtu = nla_get_u16(info->attrs[L2TP_ATTR_MTU]);
601 
602 	if (info->attrs[L2TP_ATTR_MRU])
603 		cfg.mru = nla_get_u16(info->attrs[L2TP_ATTR_MRU]);
604 
605 #ifdef CONFIG_MODULES
606 	if (l2tp_nl_cmd_ops[cfg.pw_type] == NULL) {
607 		genl_unlock();
608 		request_module("net-l2tp-type-%u", cfg.pw_type);
609 		genl_lock();
610 	}
611 #endif
612 	if ((l2tp_nl_cmd_ops[cfg.pw_type] == NULL) ||
613 	    (l2tp_nl_cmd_ops[cfg.pw_type]->session_create == NULL)) {
614 		ret = -EPROTONOSUPPORT;
615 		goto out;
616 	}
617 
618 	/* Check that pseudowire-specific params are present */
619 	switch (cfg.pw_type) {
620 	case L2TP_PWTYPE_NONE:
621 		break;
622 	case L2TP_PWTYPE_ETH_VLAN:
623 		if (!info->attrs[L2TP_ATTR_VLAN_ID]) {
624 			ret = -EINVAL;
625 			goto out;
626 		}
627 		break;
628 	case L2TP_PWTYPE_ETH:
629 		break;
630 	case L2TP_PWTYPE_PPP:
631 	case L2TP_PWTYPE_PPP_AC:
632 		break;
633 	case L2TP_PWTYPE_IP:
634 	default:
635 		ret = -EPROTONOSUPPORT;
636 		break;
637 	}
638 
639 	ret = -EPROTONOSUPPORT;
640 	if (l2tp_nl_cmd_ops[cfg.pw_type]->session_create)
641 		ret = (*l2tp_nl_cmd_ops[cfg.pw_type]->session_create)(net, tunnel_id,
642 			session_id, peer_session_id, &cfg);
643 
644 	if (ret >= 0) {
645 		session = l2tp_session_find(net, tunnel, session_id);
646 		if (session)
647 			ret = l2tp_session_notify(&l2tp_nl_family, info, session,
648 						  L2TP_CMD_SESSION_CREATE);
649 	}
650 
651 out:
652 	return ret;
653 }
654 
655 static int l2tp_nl_cmd_session_delete(struct sk_buff *skb, struct genl_info *info)
656 {
657 	int ret = 0;
658 	struct l2tp_session *session;
659 	u16 pw_type;
660 
661 	session = l2tp_nl_session_find(info);
662 	if (session == NULL) {
663 		ret = -ENODEV;
664 		goto out;
665 	}
666 
667 	l2tp_session_notify(&l2tp_nl_family, info,
668 			    session, L2TP_CMD_SESSION_DELETE);
669 
670 	pw_type = session->pwtype;
671 	if (pw_type < __L2TP_PWTYPE_MAX)
672 		if (l2tp_nl_cmd_ops[pw_type] && l2tp_nl_cmd_ops[pw_type]->session_delete)
673 			ret = (*l2tp_nl_cmd_ops[pw_type]->session_delete)(session);
674 
675 out:
676 	return ret;
677 }
678 
679 static int l2tp_nl_cmd_session_modify(struct sk_buff *skb, struct genl_info *info)
680 {
681 	int ret = 0;
682 	struct l2tp_session *session;
683 
684 	session = l2tp_nl_session_find(info);
685 	if (session == NULL) {
686 		ret = -ENODEV;
687 		goto out;
688 	}
689 
690 	if (info->attrs[L2TP_ATTR_DEBUG])
691 		session->debug = nla_get_u32(info->attrs[L2TP_ATTR_DEBUG]);
692 
693 	if (info->attrs[L2TP_ATTR_DATA_SEQ])
694 		session->data_seq = nla_get_u8(info->attrs[L2TP_ATTR_DATA_SEQ]);
695 
696 	if (info->attrs[L2TP_ATTR_RECV_SEQ])
697 		session->recv_seq = nla_get_u8(info->attrs[L2TP_ATTR_RECV_SEQ]);
698 
699 	if (info->attrs[L2TP_ATTR_SEND_SEQ]) {
700 		session->send_seq = nla_get_u8(info->attrs[L2TP_ATTR_SEND_SEQ]);
701 		l2tp_session_set_header_len(session, session->tunnel->version);
702 	}
703 
704 	if (info->attrs[L2TP_ATTR_LNS_MODE])
705 		session->lns_mode = nla_get_u8(info->attrs[L2TP_ATTR_LNS_MODE]);
706 
707 	if (info->attrs[L2TP_ATTR_RECV_TIMEOUT])
708 		session->reorder_timeout = nla_get_msecs(info->attrs[L2TP_ATTR_RECV_TIMEOUT]);
709 
710 	if (info->attrs[L2TP_ATTR_MTU])
711 		session->mtu = nla_get_u16(info->attrs[L2TP_ATTR_MTU]);
712 
713 	if (info->attrs[L2TP_ATTR_MRU])
714 		session->mru = nla_get_u16(info->attrs[L2TP_ATTR_MRU]);
715 
716 	ret = l2tp_session_notify(&l2tp_nl_family, info,
717 				  session, L2TP_CMD_SESSION_MODIFY);
718 
719 out:
720 	return ret;
721 }
722 
723 static int l2tp_nl_session_send(struct sk_buff *skb, u32 portid, u32 seq, int flags,
724 				struct l2tp_session *session, u8 cmd)
725 {
726 	void *hdr;
727 	struct nlattr *nest;
728 	struct l2tp_tunnel *tunnel = session->tunnel;
729 	struct sock *sk = NULL;
730 
731 	sk = tunnel->sock;
732 
733 	hdr = genlmsg_put(skb, portid, seq, &l2tp_nl_family, flags, cmd);
734 	if (!hdr)
735 		return -EMSGSIZE;
736 
737 	if (nla_put_u32(skb, L2TP_ATTR_CONN_ID, tunnel->tunnel_id) ||
738 	    nla_put_u32(skb, L2TP_ATTR_SESSION_ID, session->session_id) ||
739 	    nla_put_u32(skb, L2TP_ATTR_PEER_CONN_ID, tunnel->peer_tunnel_id) ||
740 	    nla_put_u32(skb, L2TP_ATTR_PEER_SESSION_ID,
741 			session->peer_session_id) ||
742 	    nla_put_u32(skb, L2TP_ATTR_DEBUG, session->debug) ||
743 	    nla_put_u16(skb, L2TP_ATTR_PW_TYPE, session->pwtype) ||
744 	    nla_put_u16(skb, L2TP_ATTR_MTU, session->mtu) ||
745 	    (session->mru &&
746 	     nla_put_u16(skb, L2TP_ATTR_MRU, session->mru)))
747 		goto nla_put_failure;
748 
749 	if ((session->ifname[0] &&
750 	     nla_put_string(skb, L2TP_ATTR_IFNAME, session->ifname)) ||
751 	    (session->cookie_len &&
752 	     nla_put(skb, L2TP_ATTR_COOKIE, session->cookie_len,
753 		     &session->cookie[0])) ||
754 	    (session->peer_cookie_len &&
755 	     nla_put(skb, L2TP_ATTR_PEER_COOKIE, session->peer_cookie_len,
756 		     &session->peer_cookie[0])) ||
757 	    nla_put_u8(skb, L2TP_ATTR_RECV_SEQ, session->recv_seq) ||
758 	    nla_put_u8(skb, L2TP_ATTR_SEND_SEQ, session->send_seq) ||
759 	    nla_put_u8(skb, L2TP_ATTR_LNS_MODE, session->lns_mode) ||
760 #ifdef CONFIG_XFRM
761 	    (((sk) && (sk->sk_policy[0] || sk->sk_policy[1])) &&
762 	     nla_put_u8(skb, L2TP_ATTR_USING_IPSEC, 1)) ||
763 #endif
764 	    (session->reorder_timeout &&
765 	     nla_put_msecs(skb, L2TP_ATTR_RECV_TIMEOUT,
766 			   session->reorder_timeout, L2TP_ATTR_PAD)))
767 		goto nla_put_failure;
768 
769 	nest = nla_nest_start(skb, L2TP_ATTR_STATS);
770 	if (nest == NULL)
771 		goto nla_put_failure;
772 
773 	if (nla_put_u64_64bit(skb, L2TP_ATTR_TX_PACKETS,
774 			      atomic_long_read(&session->stats.tx_packets),
775 			      L2TP_ATTR_STATS_PAD) ||
776 	    nla_put_u64_64bit(skb, L2TP_ATTR_TX_BYTES,
777 			      atomic_long_read(&session->stats.tx_bytes),
778 			      L2TP_ATTR_STATS_PAD) ||
779 	    nla_put_u64_64bit(skb, L2TP_ATTR_TX_ERRORS,
780 			      atomic_long_read(&session->stats.tx_errors),
781 			      L2TP_ATTR_STATS_PAD) ||
782 	    nla_put_u64_64bit(skb, L2TP_ATTR_RX_PACKETS,
783 			      atomic_long_read(&session->stats.rx_packets),
784 			      L2TP_ATTR_STATS_PAD) ||
785 	    nla_put_u64_64bit(skb, L2TP_ATTR_RX_BYTES,
786 			      atomic_long_read(&session->stats.rx_bytes),
787 			      L2TP_ATTR_STATS_PAD) ||
788 	    nla_put_u64_64bit(skb, L2TP_ATTR_RX_SEQ_DISCARDS,
789 			      atomic_long_read(&session->stats.rx_seq_discards),
790 			      L2TP_ATTR_STATS_PAD) ||
791 	    nla_put_u64_64bit(skb, L2TP_ATTR_RX_OOS_PACKETS,
792 			      atomic_long_read(&session->stats.rx_oos_packets),
793 			      L2TP_ATTR_STATS_PAD) ||
794 	    nla_put_u64_64bit(skb, L2TP_ATTR_RX_ERRORS,
795 			      atomic_long_read(&session->stats.rx_errors),
796 			      L2TP_ATTR_STATS_PAD))
797 		goto nla_put_failure;
798 	nla_nest_end(skb, nest);
799 
800 	genlmsg_end(skb, hdr);
801 	return 0;
802 
803  nla_put_failure:
804 	genlmsg_cancel(skb, hdr);
805 	return -1;
806 }
807 
808 static int l2tp_nl_cmd_session_get(struct sk_buff *skb, struct genl_info *info)
809 {
810 	struct l2tp_session *session;
811 	struct sk_buff *msg;
812 	int ret;
813 
814 	session = l2tp_nl_session_find(info);
815 	if (session == NULL) {
816 		ret = -ENODEV;
817 		goto out;
818 	}
819 
820 	msg = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);
821 	if (!msg) {
822 		ret = -ENOMEM;
823 		goto out;
824 	}
825 
826 	ret = l2tp_nl_session_send(msg, info->snd_portid, info->snd_seq,
827 				   0, session, L2TP_CMD_SESSION_GET);
828 	if (ret < 0)
829 		goto err_out;
830 
831 	return genlmsg_unicast(genl_info_net(info), msg, info->snd_portid);
832 
833 err_out:
834 	nlmsg_free(msg);
835 
836 out:
837 	return ret;
838 }
839 
840 static int l2tp_nl_cmd_session_dump(struct sk_buff *skb, struct netlink_callback *cb)
841 {
842 	struct net *net = sock_net(skb->sk);
843 	struct l2tp_session *session;
844 	struct l2tp_tunnel *tunnel = NULL;
845 	int ti = cb->args[0];
846 	int si = cb->args[1];
847 
848 	for (;;) {
849 		if (tunnel == NULL) {
850 			tunnel = l2tp_tunnel_find_nth(net, ti);
851 			if (tunnel == NULL)
852 				goto out;
853 		}
854 
855 		session = l2tp_session_find_nth(tunnel, si);
856 		if (session == NULL) {
857 			ti++;
858 			tunnel = NULL;
859 			si = 0;
860 			continue;
861 		}
862 
863 		if (l2tp_nl_session_send(skb, NETLINK_CB(cb->skb).portid,
864 					 cb->nlh->nlmsg_seq, NLM_F_MULTI,
865 					 session, L2TP_CMD_SESSION_GET) < 0)
866 			break;
867 
868 		si++;
869 	}
870 
871 out:
872 	cb->args[0] = ti;
873 	cb->args[1] = si;
874 
875 	return skb->len;
876 }
877 
878 static const struct nla_policy l2tp_nl_policy[L2TP_ATTR_MAX + 1] = {
879 	[L2TP_ATTR_NONE]		= { .type = NLA_UNSPEC, },
880 	[L2TP_ATTR_PW_TYPE]		= { .type = NLA_U16, },
881 	[L2TP_ATTR_ENCAP_TYPE]		= { .type = NLA_U16, },
882 	[L2TP_ATTR_OFFSET]		= { .type = NLA_U16, },
883 	[L2TP_ATTR_DATA_SEQ]		= { .type = NLA_U8, },
884 	[L2TP_ATTR_L2SPEC_TYPE]		= { .type = NLA_U8, },
885 	[L2TP_ATTR_L2SPEC_LEN]		= { .type = NLA_U8, },
886 	[L2TP_ATTR_PROTO_VERSION]	= { .type = NLA_U8, },
887 	[L2TP_ATTR_CONN_ID]		= { .type = NLA_U32, },
888 	[L2TP_ATTR_PEER_CONN_ID]	= { .type = NLA_U32, },
889 	[L2TP_ATTR_SESSION_ID]		= { .type = NLA_U32, },
890 	[L2TP_ATTR_PEER_SESSION_ID]	= { .type = NLA_U32, },
891 	[L2TP_ATTR_UDP_CSUM]		= { .type = NLA_U8, },
892 	[L2TP_ATTR_VLAN_ID]		= { .type = NLA_U16, },
893 	[L2TP_ATTR_DEBUG]		= { .type = NLA_U32, },
894 	[L2TP_ATTR_RECV_SEQ]		= { .type = NLA_U8, },
895 	[L2TP_ATTR_SEND_SEQ]		= { .type = NLA_U8, },
896 	[L2TP_ATTR_LNS_MODE]		= { .type = NLA_U8, },
897 	[L2TP_ATTR_USING_IPSEC]		= { .type = NLA_U8, },
898 	[L2TP_ATTR_RECV_TIMEOUT]	= { .type = NLA_MSECS, },
899 	[L2TP_ATTR_FD]			= { .type = NLA_U32, },
900 	[L2TP_ATTR_IP_SADDR]		= { .type = NLA_U32, },
901 	[L2TP_ATTR_IP_DADDR]		= { .type = NLA_U32, },
902 	[L2TP_ATTR_UDP_SPORT]		= { .type = NLA_U16, },
903 	[L2TP_ATTR_UDP_DPORT]		= { .type = NLA_U16, },
904 	[L2TP_ATTR_MTU]			= { .type = NLA_U16, },
905 	[L2TP_ATTR_MRU]			= { .type = NLA_U16, },
906 	[L2TP_ATTR_STATS]		= { .type = NLA_NESTED, },
907 	[L2TP_ATTR_IP6_SADDR] = {
908 		.type = NLA_BINARY,
909 		.len = sizeof(struct in6_addr),
910 	},
911 	[L2TP_ATTR_IP6_DADDR] = {
912 		.type = NLA_BINARY,
913 		.len = sizeof(struct in6_addr),
914 	},
915 	[L2TP_ATTR_IFNAME] = {
916 		.type = NLA_NUL_STRING,
917 		.len = IFNAMSIZ - 1,
918 	},
919 	[L2TP_ATTR_COOKIE] = {
920 		.type = NLA_BINARY,
921 		.len = 8,
922 	},
923 	[L2TP_ATTR_PEER_COOKIE] = {
924 		.type = NLA_BINARY,
925 		.len = 8,
926 	},
927 };
928 
929 static const struct genl_ops l2tp_nl_ops[] = {
930 	{
931 		.cmd = L2TP_CMD_NOOP,
932 		.doit = l2tp_nl_cmd_noop,
933 		.policy = l2tp_nl_policy,
934 		/* can be retrieved by unprivileged users */
935 	},
936 	{
937 		.cmd = L2TP_CMD_TUNNEL_CREATE,
938 		.doit = l2tp_nl_cmd_tunnel_create,
939 		.policy = l2tp_nl_policy,
940 		.flags = GENL_ADMIN_PERM,
941 	},
942 	{
943 		.cmd = L2TP_CMD_TUNNEL_DELETE,
944 		.doit = l2tp_nl_cmd_tunnel_delete,
945 		.policy = l2tp_nl_policy,
946 		.flags = GENL_ADMIN_PERM,
947 	},
948 	{
949 		.cmd = L2TP_CMD_TUNNEL_MODIFY,
950 		.doit = l2tp_nl_cmd_tunnel_modify,
951 		.policy = l2tp_nl_policy,
952 		.flags = GENL_ADMIN_PERM,
953 	},
954 	{
955 		.cmd = L2TP_CMD_TUNNEL_GET,
956 		.doit = l2tp_nl_cmd_tunnel_get,
957 		.dumpit = l2tp_nl_cmd_tunnel_dump,
958 		.policy = l2tp_nl_policy,
959 		.flags = GENL_ADMIN_PERM,
960 	},
961 	{
962 		.cmd = L2TP_CMD_SESSION_CREATE,
963 		.doit = l2tp_nl_cmd_session_create,
964 		.policy = l2tp_nl_policy,
965 		.flags = GENL_ADMIN_PERM,
966 	},
967 	{
968 		.cmd = L2TP_CMD_SESSION_DELETE,
969 		.doit = l2tp_nl_cmd_session_delete,
970 		.policy = l2tp_nl_policy,
971 		.flags = GENL_ADMIN_PERM,
972 	},
973 	{
974 		.cmd = L2TP_CMD_SESSION_MODIFY,
975 		.doit = l2tp_nl_cmd_session_modify,
976 		.policy = l2tp_nl_policy,
977 		.flags = GENL_ADMIN_PERM,
978 	},
979 	{
980 		.cmd = L2TP_CMD_SESSION_GET,
981 		.doit = l2tp_nl_cmd_session_get,
982 		.dumpit = l2tp_nl_cmd_session_dump,
983 		.policy = l2tp_nl_policy,
984 		.flags = GENL_ADMIN_PERM,
985 	},
986 };
987 
988 static struct genl_family l2tp_nl_family __ro_after_init = {
989 	.name		= L2TP_GENL_NAME,
990 	.version	= L2TP_GENL_VERSION,
991 	.hdrsize	= 0,
992 	.maxattr	= L2TP_ATTR_MAX,
993 	.netnsok	= true,
994 	.module		= THIS_MODULE,
995 	.ops		= l2tp_nl_ops,
996 	.n_ops		= ARRAY_SIZE(l2tp_nl_ops),
997 	.mcgrps		= l2tp_multicast_group,
998 	.n_mcgrps	= ARRAY_SIZE(l2tp_multicast_group),
999 };
1000 
1001 int l2tp_nl_register_ops(enum l2tp_pwtype pw_type, const struct l2tp_nl_cmd_ops *ops)
1002 {
1003 	int ret;
1004 
1005 	ret = -EINVAL;
1006 	if (pw_type >= __L2TP_PWTYPE_MAX)
1007 		goto err;
1008 
1009 	genl_lock();
1010 	ret = -EBUSY;
1011 	if (l2tp_nl_cmd_ops[pw_type])
1012 		goto out;
1013 
1014 	l2tp_nl_cmd_ops[pw_type] = ops;
1015 	ret = 0;
1016 
1017 out:
1018 	genl_unlock();
1019 err:
1020 	return ret;
1021 }
1022 EXPORT_SYMBOL_GPL(l2tp_nl_register_ops);
1023 
1024 void l2tp_nl_unregister_ops(enum l2tp_pwtype pw_type)
1025 {
1026 	if (pw_type < __L2TP_PWTYPE_MAX) {
1027 		genl_lock();
1028 		l2tp_nl_cmd_ops[pw_type] = NULL;
1029 		genl_unlock();
1030 	}
1031 }
1032 EXPORT_SYMBOL_GPL(l2tp_nl_unregister_ops);
1033 
1034 static int __init l2tp_nl_init(void)
1035 {
1036 	pr_info("L2TP netlink interface\n");
1037 	return genl_register_family(&l2tp_nl_family);
1038 }
1039 
1040 static void l2tp_nl_cleanup(void)
1041 {
1042 	genl_unregister_family(&l2tp_nl_family);
1043 }
1044 
1045 module_init(l2tp_nl_init);
1046 module_exit(l2tp_nl_cleanup);
1047 
1048 MODULE_AUTHOR("James Chapman <jchapman@katalix.com>");
1049 MODULE_DESCRIPTION("L2TP netlink");
1050 MODULE_LICENSE("GPL");
1051 MODULE_VERSION("1.0");
1052 MODULE_ALIAS_GENL_FAMILY("l2tp");
1053