xref: /openbmc/linux/net/l2tp/l2tp_netlink.c (revision b24413180f5600bcb3bb70fbed5cf186b60864bd) 
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_get(struct genl_info *info,
52 						bool do_ref)
53 {
54 	u32 tunnel_id;
55 	u32 session_id;
56 	char *ifname;
57 	struct l2tp_tunnel *tunnel;
58 	struct l2tp_session *session = NULL;
59 	struct net *net = genl_info_net(info);
60 
61 	if (info->attrs[L2TP_ATTR_IFNAME]) {
62 		ifname = nla_data(info->attrs[L2TP_ATTR_IFNAME]);
63 		session = l2tp_session_get_by_ifname(net, ifname, do_ref);
64 	} else if ((info->attrs[L2TP_ATTR_SESSION_ID]) &&
65 		   (info->attrs[L2TP_ATTR_CONN_ID])) {
66 		tunnel_id = nla_get_u32(info->attrs[L2TP_ATTR_CONN_ID]);
67 		session_id = nla_get_u32(info->attrs[L2TP_ATTR_SESSION_ID]);
68 		tunnel = l2tp_tunnel_get(net, tunnel_id);
69 		if (tunnel) {
70 			session = l2tp_session_get(net, tunnel, session_id,
71 						   do_ref);
72 			l2tp_tunnel_dec_refcount(tunnel);
73 		}
74 	}
75 
76 	return session;
77 }
78 
79 static int l2tp_nl_cmd_noop(struct sk_buff *skb, struct genl_info *info)
80 {
81 	struct sk_buff *msg;
82 	void *hdr;
83 	int ret = -ENOBUFS;
84 
85 	msg = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);
86 	if (!msg) {
87 		ret = -ENOMEM;
88 		goto out;
89 	}
90 
91 	hdr = genlmsg_put(msg, info->snd_portid, info->snd_seq,
92 			  &l2tp_nl_family, 0, L2TP_CMD_NOOP);
93 	if (!hdr) {
94 		ret = -EMSGSIZE;
95 		goto err_out;
96 	}
97 
98 	genlmsg_end(msg, hdr);
99 
100 	return genlmsg_unicast(genl_info_net(info), msg, info->snd_portid);
101 
102 err_out:
103 	nlmsg_free(msg);
104 
105 out:
106 	return ret;
107 }
108 
109 static int l2tp_tunnel_notify(struct genl_family *family,
110 			      struct genl_info *info,
111 			      struct l2tp_tunnel *tunnel,
112 			      u8 cmd)
113 {
114 	struct sk_buff *msg;
115 	int ret;
116 
117 	msg = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);
118 	if (!msg)
119 		return -ENOMEM;
120 
121 	ret = l2tp_nl_tunnel_send(msg, info->snd_portid, info->snd_seq,
122 				  NLM_F_ACK, tunnel, cmd);
123 
124 	if (ret >= 0) {
125 		ret = genlmsg_multicast_allns(family, msg, 0, 0, GFP_ATOMIC);
126 		/* We don't care if no one is listening */
127 		if (ret == -ESRCH)
128 			ret = 0;
129 		return ret;
130 	}
131 
132 	nlmsg_free(msg);
133 
134 	return ret;
135 }
136 
137 static int l2tp_session_notify(struct genl_family *family,
138 			       struct genl_info *info,
139 			       struct l2tp_session *session,
140 			       u8 cmd)
141 {
142 	struct sk_buff *msg;
143 	int ret;
144 
145 	msg = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);
146 	if (!msg)
147 		return -ENOMEM;
148 
149 	ret = l2tp_nl_session_send(msg, info->snd_portid, info->snd_seq,
150 				   NLM_F_ACK, session, cmd);
151 
152 	if (ret >= 0) {
153 		ret = genlmsg_multicast_allns(family, msg, 0, 0, GFP_ATOMIC);
154 		/* We don't care if no one is listening */
155 		if (ret == -ESRCH)
156 			ret = 0;
157 		return ret;
158 	}
159 
160 	nlmsg_free(msg);
161 
162 	return ret;
163 }
164 
165 static int l2tp_nl_cmd_tunnel_create(struct sk_buff *skb, struct genl_info *info)
166 {
167 	u32 tunnel_id;
168 	u32 peer_tunnel_id;
169 	int proto_version;
170 	int fd;
171 	int ret = 0;
172 	struct l2tp_tunnel_cfg cfg = { 0, };
173 	struct l2tp_tunnel *tunnel;
174 	struct net *net = genl_info_net(info);
175 
176 	if (!info->attrs[L2TP_ATTR_CONN_ID]) {
177 		ret = -EINVAL;
178 		goto out;
179 	}
180 	tunnel_id = nla_get_u32(info->attrs[L2TP_ATTR_CONN_ID]);
181 
182 	if (!info->attrs[L2TP_ATTR_PEER_CONN_ID]) {
183 		ret = -EINVAL;
184 		goto out;
185 	}
186 	peer_tunnel_id = nla_get_u32(info->attrs[L2TP_ATTR_PEER_CONN_ID]);
187 
188 	if (!info->attrs[L2TP_ATTR_PROTO_VERSION]) {
189 		ret = -EINVAL;
190 		goto out;
191 	}
192 	proto_version = nla_get_u8(info->attrs[L2TP_ATTR_PROTO_VERSION]);
193 
194 	if (!info->attrs[L2TP_ATTR_ENCAP_TYPE]) {
195 		ret = -EINVAL;
196 		goto out;
197 	}
198 	cfg.encap = nla_get_u16(info->attrs[L2TP_ATTR_ENCAP_TYPE]);
199 
200 	fd = -1;
201 	if (info->attrs[L2TP_ATTR_FD]) {
202 		fd = nla_get_u32(info->attrs[L2TP_ATTR_FD]);
203 	} else {
204 #if IS_ENABLED(CONFIG_IPV6)
205 		if (info->attrs[L2TP_ATTR_IP6_SADDR] &&
206 		    info->attrs[L2TP_ATTR_IP6_DADDR]) {
207 			cfg.local_ip6 = nla_data(
208 				info->attrs[L2TP_ATTR_IP6_SADDR]);
209 			cfg.peer_ip6 = nla_data(
210 				info->attrs[L2TP_ATTR_IP6_DADDR]);
211 		} else
212 #endif
213 		if (info->attrs[L2TP_ATTR_IP_SADDR] &&
214 		    info->attrs[L2TP_ATTR_IP_DADDR]) {
215 			cfg.local_ip.s_addr = nla_get_in_addr(
216 				info->attrs[L2TP_ATTR_IP_SADDR]);
217 			cfg.peer_ip.s_addr = nla_get_in_addr(
218 				info->attrs[L2TP_ATTR_IP_DADDR]);
219 		} else {
220 			ret = -EINVAL;
221 			goto out;
222 		}
223 		if (info->attrs[L2TP_ATTR_UDP_SPORT])
224 			cfg.local_udp_port = nla_get_u16(info->attrs[L2TP_ATTR_UDP_SPORT]);
225 		if (info->attrs[L2TP_ATTR_UDP_DPORT])
226 			cfg.peer_udp_port = nla_get_u16(info->attrs[L2TP_ATTR_UDP_DPORT]);
227 		cfg.use_udp_checksums = nla_get_flag(
228 			info->attrs[L2TP_ATTR_UDP_CSUM]);
229 
230 #if IS_ENABLED(CONFIG_IPV6)
231 		cfg.udp6_zero_tx_checksums = nla_get_flag(
232 			info->attrs[L2TP_ATTR_UDP_ZERO_CSUM6_TX]);
233 		cfg.udp6_zero_rx_checksums = nla_get_flag(
234 			info->attrs[L2TP_ATTR_UDP_ZERO_CSUM6_RX]);
235 #endif
236 	}
237 
238 	if (info->attrs[L2TP_ATTR_DEBUG])
239 		cfg.debug = nla_get_u32(info->attrs[L2TP_ATTR_DEBUG]);
240 
241 	tunnel = l2tp_tunnel_find(net, tunnel_id);
242 	if (tunnel != NULL) {
243 		ret = -EEXIST;
244 		goto out;
245 	}
246 
247 	ret = -EINVAL;
248 	switch (cfg.encap) {
249 	case L2TP_ENCAPTYPE_UDP:
250 	case L2TP_ENCAPTYPE_IP:
251 		ret = l2tp_tunnel_create(net, fd, proto_version, tunnel_id,
252 					 peer_tunnel_id, &cfg, &tunnel);
253 		break;
254 	}
255 
256 	if (ret >= 0)
257 		ret = l2tp_tunnel_notify(&l2tp_nl_family, info,
258 					 tunnel, L2TP_CMD_TUNNEL_CREATE);
259 out:
260 	return ret;
261 }
262 
263 static int l2tp_nl_cmd_tunnel_delete(struct sk_buff *skb, struct genl_info *info)
264 {
265 	struct l2tp_tunnel *tunnel;
266 	u32 tunnel_id;
267 	int ret = 0;
268 	struct net *net = genl_info_net(info);
269 
270 	if (!info->attrs[L2TP_ATTR_CONN_ID]) {
271 		ret = -EINVAL;
272 		goto out;
273 	}
274 	tunnel_id = nla_get_u32(info->attrs[L2TP_ATTR_CONN_ID]);
275 
276 	tunnel = l2tp_tunnel_get(net, tunnel_id);
277 	if (!tunnel) {
278 		ret = -ENODEV;
279 		goto out;
280 	}
281 
282 	l2tp_tunnel_notify(&l2tp_nl_family, info,
283 			   tunnel, L2TP_CMD_TUNNEL_DELETE);
284 
285 	(void) l2tp_tunnel_delete(tunnel);
286 
287 	l2tp_tunnel_dec_refcount(tunnel);
288 
289 out:
290 	return ret;
291 }
292 
293 static int l2tp_nl_cmd_tunnel_modify(struct sk_buff *skb, struct genl_info *info)
294 {
295 	struct l2tp_tunnel *tunnel;
296 	u32 tunnel_id;
297 	int ret = 0;
298 	struct net *net = genl_info_net(info);
299 
300 	if (!info->attrs[L2TP_ATTR_CONN_ID]) {
301 		ret = -EINVAL;
302 		goto out;
303 	}
304 	tunnel_id = nla_get_u32(info->attrs[L2TP_ATTR_CONN_ID]);
305 
306 	tunnel = l2tp_tunnel_get(net, tunnel_id);
307 	if (!tunnel) {
308 		ret = -ENODEV;
309 		goto out;
310 	}
311 
312 	if (info->attrs[L2TP_ATTR_DEBUG])
313 		tunnel->debug = nla_get_u32(info->attrs[L2TP_ATTR_DEBUG]);
314 
315 	ret = l2tp_tunnel_notify(&l2tp_nl_family, info,
316 				 tunnel, L2TP_CMD_TUNNEL_MODIFY);
317 
318 	l2tp_tunnel_dec_refcount(tunnel);
319 
320 out:
321 	return ret;
322 }
323 
324 static int l2tp_nl_tunnel_send(struct sk_buff *skb, u32 portid, u32 seq, int flags,
325 			       struct l2tp_tunnel *tunnel, u8 cmd)
326 {
327 	void *hdr;
328 	struct nlattr *nest;
329 	struct sock *sk = NULL;
330 	struct inet_sock *inet;
331 #if IS_ENABLED(CONFIG_IPV6)
332 	struct ipv6_pinfo *np = NULL;
333 #endif
334 
335 	hdr = genlmsg_put(skb, portid, seq, &l2tp_nl_family, flags, cmd);
336 	if (!hdr)
337 		return -EMSGSIZE;
338 
339 	if (nla_put_u8(skb, L2TP_ATTR_PROTO_VERSION, tunnel->version) ||
340 	    nla_put_u32(skb, L2TP_ATTR_CONN_ID, tunnel->tunnel_id) ||
341 	    nla_put_u32(skb, L2TP_ATTR_PEER_CONN_ID, tunnel->peer_tunnel_id) ||
342 	    nla_put_u32(skb, L2TP_ATTR_DEBUG, tunnel->debug) ||
343 	    nla_put_u16(skb, L2TP_ATTR_ENCAP_TYPE, tunnel->encap))
344 		goto nla_put_failure;
345 
346 	nest = nla_nest_start(skb, L2TP_ATTR_STATS);
347 	if (nest == NULL)
348 		goto nla_put_failure;
349 
350 	if (nla_put_u64_64bit(skb, L2TP_ATTR_TX_PACKETS,
351 			      atomic_long_read(&tunnel->stats.tx_packets),
352 			      L2TP_ATTR_STATS_PAD) ||
353 	    nla_put_u64_64bit(skb, L2TP_ATTR_TX_BYTES,
354 			      atomic_long_read(&tunnel->stats.tx_bytes),
355 			      L2TP_ATTR_STATS_PAD) ||
356 	    nla_put_u64_64bit(skb, L2TP_ATTR_TX_ERRORS,
357 			      atomic_long_read(&tunnel->stats.tx_errors),
358 			      L2TP_ATTR_STATS_PAD) ||
359 	    nla_put_u64_64bit(skb, L2TP_ATTR_RX_PACKETS,
360 			      atomic_long_read(&tunnel->stats.rx_packets),
361 			      L2TP_ATTR_STATS_PAD) ||
362 	    nla_put_u64_64bit(skb, L2TP_ATTR_RX_BYTES,
363 			      atomic_long_read(&tunnel->stats.rx_bytes),
364 			      L2TP_ATTR_STATS_PAD) ||
365 	    nla_put_u64_64bit(skb, L2TP_ATTR_RX_SEQ_DISCARDS,
366 			      atomic_long_read(&tunnel->stats.rx_seq_discards),
367 			      L2TP_ATTR_STATS_PAD) ||
368 	    nla_put_u64_64bit(skb, L2TP_ATTR_RX_OOS_PACKETS,
369 			      atomic_long_read(&tunnel->stats.rx_oos_packets),
370 			      L2TP_ATTR_STATS_PAD) ||
371 	    nla_put_u64_64bit(skb, L2TP_ATTR_RX_ERRORS,
372 			      atomic_long_read(&tunnel->stats.rx_errors),
373 			      L2TP_ATTR_STATS_PAD))
374 		goto nla_put_failure;
375 	nla_nest_end(skb, nest);
376 
377 	sk = tunnel->sock;
378 	if (!sk)
379 		goto out;
380 
381 #if IS_ENABLED(CONFIG_IPV6)
382 	if (sk->sk_family == AF_INET6)
383 		np = inet6_sk(sk);
384 #endif
385 
386 	inet = inet_sk(sk);
387 
388 	switch (tunnel->encap) {
389 	case L2TP_ENCAPTYPE_UDP:
390 		switch (sk->sk_family) {
391 		case AF_INET:
392 			if (nla_put_u8(skb, L2TP_ATTR_UDP_CSUM, !sk->sk_no_check_tx))
393 				goto nla_put_failure;
394 			break;
395 #if IS_ENABLED(CONFIG_IPV6)
396 		case AF_INET6:
397 			if (udp_get_no_check6_tx(sk) &&
398 			    nla_put_flag(skb, L2TP_ATTR_UDP_ZERO_CSUM6_TX))
399 				goto nla_put_failure;
400 			if (udp_get_no_check6_rx(sk) &&
401 			    nla_put_flag(skb, L2TP_ATTR_UDP_ZERO_CSUM6_RX))
402 				goto nla_put_failure;
403 			break;
404 #endif
405 		}
406 		if (nla_put_u16(skb, L2TP_ATTR_UDP_SPORT, ntohs(inet->inet_sport)) ||
407 		    nla_put_u16(skb, L2TP_ATTR_UDP_DPORT, ntohs(inet->inet_dport)))
408 			goto nla_put_failure;
409 		/* NOBREAK */
410 	case L2TP_ENCAPTYPE_IP:
411 #if IS_ENABLED(CONFIG_IPV6)
412 		if (np) {
413 			if (nla_put_in6_addr(skb, L2TP_ATTR_IP6_SADDR,
414 					     &np->saddr) ||
415 			    nla_put_in6_addr(skb, L2TP_ATTR_IP6_DADDR,
416 					     &sk->sk_v6_daddr))
417 				goto nla_put_failure;
418 		} else
419 #endif
420 		if (nla_put_in_addr(skb, L2TP_ATTR_IP_SADDR,
421 				    inet->inet_saddr) ||
422 		    nla_put_in_addr(skb, L2TP_ATTR_IP_DADDR,
423 				    inet->inet_daddr))
424 			goto nla_put_failure;
425 		break;
426 	}
427 
428 out:
429 	genlmsg_end(skb, hdr);
430 	return 0;
431 
432 nla_put_failure:
433 	genlmsg_cancel(skb, hdr);
434 	return -1;
435 }
436 
437 static int l2tp_nl_cmd_tunnel_get(struct sk_buff *skb, struct genl_info *info)
438 {
439 	struct l2tp_tunnel *tunnel;
440 	struct sk_buff *msg;
441 	u32 tunnel_id;
442 	int ret = -ENOBUFS;
443 	struct net *net = genl_info_net(info);
444 
445 	if (!info->attrs[L2TP_ATTR_CONN_ID]) {
446 		ret = -EINVAL;
447 		goto err;
448 	}
449 
450 	tunnel_id = nla_get_u32(info->attrs[L2TP_ATTR_CONN_ID]);
451 
452 	msg = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);
453 	if (!msg) {
454 		ret = -ENOMEM;
455 		goto err;
456 	}
457 
458 	tunnel = l2tp_tunnel_get(net, tunnel_id);
459 	if (!tunnel) {
460 		ret = -ENODEV;
461 		goto err_nlmsg;
462 	}
463 
464 	ret = l2tp_nl_tunnel_send(msg, info->snd_portid, info->snd_seq,
465 				  NLM_F_ACK, tunnel, L2TP_CMD_TUNNEL_GET);
466 	if (ret < 0)
467 		goto err_nlmsg_tunnel;
468 
469 	l2tp_tunnel_dec_refcount(tunnel);
470 
471 	return genlmsg_unicast(net, msg, info->snd_portid);
472 
473 err_nlmsg_tunnel:
474 	l2tp_tunnel_dec_refcount(tunnel);
475 err_nlmsg:
476 	nlmsg_free(msg);
477 err:
478 	return ret;
479 }
480 
481 static int l2tp_nl_cmd_tunnel_dump(struct sk_buff *skb, struct netlink_callback *cb)
482 {
483 	int ti = cb->args[0];
484 	struct l2tp_tunnel *tunnel;
485 	struct net *net = sock_net(skb->sk);
486 
487 	for (;;) {
488 		tunnel = l2tp_tunnel_find_nth(net, ti);
489 		if (tunnel == NULL)
490 			goto out;
491 
492 		if (l2tp_nl_tunnel_send(skb, NETLINK_CB(cb->skb).portid,
493 					cb->nlh->nlmsg_seq, NLM_F_MULTI,
494 					tunnel, L2TP_CMD_TUNNEL_GET) < 0)
495 			goto out;
496 
497 		ti++;
498 	}
499 
500 out:
501 	cb->args[0] = ti;
502 
503 	return skb->len;
504 }
505 
506 static int l2tp_nl_cmd_session_create(struct sk_buff *skb, struct genl_info *info)
507 {
508 	u32 tunnel_id = 0;
509 	u32 session_id;
510 	u32 peer_session_id;
511 	int ret = 0;
512 	struct l2tp_tunnel *tunnel;
513 	struct l2tp_session *session;
514 	struct l2tp_session_cfg cfg = { 0, };
515 	struct net *net = genl_info_net(info);
516 
517 	if (!info->attrs[L2TP_ATTR_CONN_ID]) {
518 		ret = -EINVAL;
519 		goto out;
520 	}
521 
522 	tunnel_id = nla_get_u32(info->attrs[L2TP_ATTR_CONN_ID]);
523 	tunnel = l2tp_tunnel_get(net, tunnel_id);
524 	if (!tunnel) {
525 		ret = -ENODEV;
526 		goto out;
527 	}
528 
529 	if (!info->attrs[L2TP_ATTR_SESSION_ID]) {
530 		ret = -EINVAL;
531 		goto out_tunnel;
532 	}
533 	session_id = nla_get_u32(info->attrs[L2TP_ATTR_SESSION_ID]);
534 
535 	if (!info->attrs[L2TP_ATTR_PEER_SESSION_ID]) {
536 		ret = -EINVAL;
537 		goto out_tunnel;
538 	}
539 	peer_session_id = nla_get_u32(info->attrs[L2TP_ATTR_PEER_SESSION_ID]);
540 
541 	if (!info->attrs[L2TP_ATTR_PW_TYPE]) {
542 		ret = -EINVAL;
543 		goto out_tunnel;
544 	}
545 	cfg.pw_type = nla_get_u16(info->attrs[L2TP_ATTR_PW_TYPE]);
546 	if (cfg.pw_type >= __L2TP_PWTYPE_MAX) {
547 		ret = -EINVAL;
548 		goto out_tunnel;
549 	}
550 
551 	if (tunnel->version > 2) {
552 		if (info->attrs[L2TP_ATTR_OFFSET])
553 			cfg.offset = nla_get_u16(info->attrs[L2TP_ATTR_OFFSET]);
554 
555 		if (info->attrs[L2TP_ATTR_DATA_SEQ])
556 			cfg.data_seq = nla_get_u8(info->attrs[L2TP_ATTR_DATA_SEQ]);
557 
558 		cfg.l2specific_type = L2TP_L2SPECTYPE_DEFAULT;
559 		if (info->attrs[L2TP_ATTR_L2SPEC_TYPE])
560 			cfg.l2specific_type = nla_get_u8(info->attrs[L2TP_ATTR_L2SPEC_TYPE]);
561 
562 		cfg.l2specific_len = 4;
563 		if (info->attrs[L2TP_ATTR_L2SPEC_LEN])
564 			cfg.l2specific_len = nla_get_u8(info->attrs[L2TP_ATTR_L2SPEC_LEN]);
565 
566 		if (info->attrs[L2TP_ATTR_COOKIE]) {
567 			u16 len = nla_len(info->attrs[L2TP_ATTR_COOKIE]);
568 			if (len > 8) {
569 				ret = -EINVAL;
570 				goto out_tunnel;
571 			}
572 			cfg.cookie_len = len;
573 			memcpy(&cfg.cookie[0], nla_data(info->attrs[L2TP_ATTR_COOKIE]), len);
574 		}
575 		if (info->attrs[L2TP_ATTR_PEER_COOKIE]) {
576 			u16 len = nla_len(info->attrs[L2TP_ATTR_PEER_COOKIE]);
577 			if (len > 8) {
578 				ret = -EINVAL;
579 				goto out_tunnel;
580 			}
581 			cfg.peer_cookie_len = len;
582 			memcpy(&cfg.peer_cookie[0], nla_data(info->attrs[L2TP_ATTR_PEER_COOKIE]), len);
583 		}
584 		if (info->attrs[L2TP_ATTR_IFNAME])
585 			cfg.ifname = nla_data(info->attrs[L2TP_ATTR_IFNAME]);
586 
587 		if (info->attrs[L2TP_ATTR_VLAN_ID])
588 			cfg.vlan_id = nla_get_u16(info->attrs[L2TP_ATTR_VLAN_ID]);
589 	}
590 
591 	if (info->attrs[L2TP_ATTR_DEBUG])
592 		cfg.debug = nla_get_u32(info->attrs[L2TP_ATTR_DEBUG]);
593 
594 	if (info->attrs[L2TP_ATTR_RECV_SEQ])
595 		cfg.recv_seq = nla_get_u8(info->attrs[L2TP_ATTR_RECV_SEQ]);
596 
597 	if (info->attrs[L2TP_ATTR_SEND_SEQ])
598 		cfg.send_seq = nla_get_u8(info->attrs[L2TP_ATTR_SEND_SEQ]);
599 
600 	if (info->attrs[L2TP_ATTR_LNS_MODE])
601 		cfg.lns_mode = nla_get_u8(info->attrs[L2TP_ATTR_LNS_MODE]);
602 
603 	if (info->attrs[L2TP_ATTR_RECV_TIMEOUT])
604 		cfg.reorder_timeout = nla_get_msecs(info->attrs[L2TP_ATTR_RECV_TIMEOUT]);
605 
606 	if (info->attrs[L2TP_ATTR_MTU])
607 		cfg.mtu = nla_get_u16(info->attrs[L2TP_ATTR_MTU]);
608 
609 	if (info->attrs[L2TP_ATTR_MRU])
610 		cfg.mru = nla_get_u16(info->attrs[L2TP_ATTR_MRU]);
611 
612 #ifdef CONFIG_MODULES
613 	if (l2tp_nl_cmd_ops[cfg.pw_type] == NULL) {
614 		genl_unlock();
615 		request_module("net-l2tp-type-%u", cfg.pw_type);
616 		genl_lock();
617 	}
618 #endif
619 	if ((l2tp_nl_cmd_ops[cfg.pw_type] == NULL) ||
620 	    (l2tp_nl_cmd_ops[cfg.pw_type]->session_create == NULL)) {
621 		ret = -EPROTONOSUPPORT;
622 		goto out_tunnel;
623 	}
624 
625 	/* Check that pseudowire-specific params are present */
626 	switch (cfg.pw_type) {
627 	case L2TP_PWTYPE_NONE:
628 		break;
629 	case L2TP_PWTYPE_ETH_VLAN:
630 		if (!info->attrs[L2TP_ATTR_VLAN_ID]) {
631 			ret = -EINVAL;
632 			goto out_tunnel;
633 		}
634 		break;
635 	case L2TP_PWTYPE_ETH:
636 		break;
637 	case L2TP_PWTYPE_PPP:
638 	case L2TP_PWTYPE_PPP_AC:
639 		break;
640 	case L2TP_PWTYPE_IP:
641 	default:
642 		ret = -EPROTONOSUPPORT;
643 		break;
644 	}
645 
646 	ret = l2tp_nl_cmd_ops[cfg.pw_type]->session_create(net, tunnel,
647 							   session_id,
648 							   peer_session_id,
649 							   &cfg);
650 
651 	if (ret >= 0) {
652 		session = l2tp_session_get(net, tunnel, session_id, false);
653 		if (session) {
654 			ret = l2tp_session_notify(&l2tp_nl_family, info, session,
655 						  L2TP_CMD_SESSION_CREATE);
656 			l2tp_session_dec_refcount(session);
657 		}
658 	}
659 
660 out_tunnel:
661 	l2tp_tunnel_dec_refcount(tunnel);
662 out:
663 	return ret;
664 }
665 
666 static int l2tp_nl_cmd_session_delete(struct sk_buff *skb, struct genl_info *info)
667 {
668 	int ret = 0;
669 	struct l2tp_session *session;
670 	u16 pw_type;
671 
672 	session = l2tp_nl_session_get(info, true);
673 	if (session == NULL) {
674 		ret = -ENODEV;
675 		goto out;
676 	}
677 
678 	l2tp_session_notify(&l2tp_nl_family, info,
679 			    session, L2TP_CMD_SESSION_DELETE);
680 
681 	pw_type = session->pwtype;
682 	if (pw_type < __L2TP_PWTYPE_MAX)
683 		if (l2tp_nl_cmd_ops[pw_type] && l2tp_nl_cmd_ops[pw_type]->session_delete)
684 			ret = (*l2tp_nl_cmd_ops[pw_type]->session_delete)(session);
685 
686 	if (session->deref)
687 		session->deref(session);
688 	l2tp_session_dec_refcount(session);
689 
690 out:
691 	return ret;
692 }
693 
694 static int l2tp_nl_cmd_session_modify(struct sk_buff *skb, struct genl_info *info)
695 {
696 	int ret = 0;
697 	struct l2tp_session *session;
698 
699 	session = l2tp_nl_session_get(info, false);
700 	if (session == NULL) {
701 		ret = -ENODEV;
702 		goto out;
703 	}
704 
705 	if (info->attrs[L2TP_ATTR_DEBUG])
706 		session->debug = nla_get_u32(info->attrs[L2TP_ATTR_DEBUG]);
707 
708 	if (info->attrs[L2TP_ATTR_DATA_SEQ])
709 		session->data_seq = nla_get_u8(info->attrs[L2TP_ATTR_DATA_SEQ]);
710 
711 	if (info->attrs[L2TP_ATTR_RECV_SEQ])
712 		session->recv_seq = nla_get_u8(info->attrs[L2TP_ATTR_RECV_SEQ]);
713 
714 	if (info->attrs[L2TP_ATTR_SEND_SEQ]) {
715 		session->send_seq = nla_get_u8(info->attrs[L2TP_ATTR_SEND_SEQ]);
716 		l2tp_session_set_header_len(session, session->tunnel->version);
717 	}
718 
719 	if (info->attrs[L2TP_ATTR_LNS_MODE])
720 		session->lns_mode = nla_get_u8(info->attrs[L2TP_ATTR_LNS_MODE]);
721 
722 	if (info->attrs[L2TP_ATTR_RECV_TIMEOUT])
723 		session->reorder_timeout = nla_get_msecs(info->attrs[L2TP_ATTR_RECV_TIMEOUT]);
724 
725 	if (info->attrs[L2TP_ATTR_MTU])
726 		session->mtu = nla_get_u16(info->attrs[L2TP_ATTR_MTU]);
727 
728 	if (info->attrs[L2TP_ATTR_MRU])
729 		session->mru = nla_get_u16(info->attrs[L2TP_ATTR_MRU]);
730 
731 	ret = l2tp_session_notify(&l2tp_nl_family, info,
732 				  session, L2TP_CMD_SESSION_MODIFY);
733 
734 	l2tp_session_dec_refcount(session);
735 
736 out:
737 	return ret;
738 }
739 
740 static int l2tp_nl_session_send(struct sk_buff *skb, u32 portid, u32 seq, int flags,
741 				struct l2tp_session *session, u8 cmd)
742 {
743 	void *hdr;
744 	struct nlattr *nest;
745 	struct l2tp_tunnel *tunnel = session->tunnel;
746 	struct sock *sk = NULL;
747 
748 	sk = tunnel->sock;
749 
750 	hdr = genlmsg_put(skb, portid, seq, &l2tp_nl_family, flags, cmd);
751 	if (!hdr)
752 		return -EMSGSIZE;
753 
754 	if (nla_put_u32(skb, L2TP_ATTR_CONN_ID, tunnel->tunnel_id) ||
755 	    nla_put_u32(skb, L2TP_ATTR_SESSION_ID, session->session_id) ||
756 	    nla_put_u32(skb, L2TP_ATTR_PEER_CONN_ID, tunnel->peer_tunnel_id) ||
757 	    nla_put_u32(skb, L2TP_ATTR_PEER_SESSION_ID,
758 			session->peer_session_id) ||
759 	    nla_put_u32(skb, L2TP_ATTR_DEBUG, session->debug) ||
760 	    nla_put_u16(skb, L2TP_ATTR_PW_TYPE, session->pwtype) ||
761 	    nla_put_u16(skb, L2TP_ATTR_MTU, session->mtu) ||
762 	    (session->mru &&
763 	     nla_put_u16(skb, L2TP_ATTR_MRU, session->mru)))
764 		goto nla_put_failure;
765 
766 	if ((session->ifname[0] &&
767 	     nla_put_string(skb, L2TP_ATTR_IFNAME, session->ifname)) ||
768 	    (session->cookie_len &&
769 	     nla_put(skb, L2TP_ATTR_COOKIE, session->cookie_len,
770 		     &session->cookie[0])) ||
771 	    (session->peer_cookie_len &&
772 	     nla_put(skb, L2TP_ATTR_PEER_COOKIE, session->peer_cookie_len,
773 		     &session->peer_cookie[0])) ||
774 	    nla_put_u8(skb, L2TP_ATTR_RECV_SEQ, session->recv_seq) ||
775 	    nla_put_u8(skb, L2TP_ATTR_SEND_SEQ, session->send_seq) ||
776 	    nla_put_u8(skb, L2TP_ATTR_LNS_MODE, session->lns_mode) ||
777 #ifdef CONFIG_XFRM
778 	    (((sk) && (sk->sk_policy[0] || sk->sk_policy[1])) &&
779 	     nla_put_u8(skb, L2TP_ATTR_USING_IPSEC, 1)) ||
780 #endif
781 	    (session->reorder_timeout &&
782 	     nla_put_msecs(skb, L2TP_ATTR_RECV_TIMEOUT,
783 			   session->reorder_timeout, L2TP_ATTR_PAD)))
784 		goto nla_put_failure;
785 
786 	nest = nla_nest_start(skb, L2TP_ATTR_STATS);
787 	if (nest == NULL)
788 		goto nla_put_failure;
789 
790 	if (nla_put_u64_64bit(skb, L2TP_ATTR_TX_PACKETS,
791 			      atomic_long_read(&session->stats.tx_packets),
792 			      L2TP_ATTR_STATS_PAD) ||
793 	    nla_put_u64_64bit(skb, L2TP_ATTR_TX_BYTES,
794 			      atomic_long_read(&session->stats.tx_bytes),
795 			      L2TP_ATTR_STATS_PAD) ||
796 	    nla_put_u64_64bit(skb, L2TP_ATTR_TX_ERRORS,
797 			      atomic_long_read(&session->stats.tx_errors),
798 			      L2TP_ATTR_STATS_PAD) ||
799 	    nla_put_u64_64bit(skb, L2TP_ATTR_RX_PACKETS,
800 			      atomic_long_read(&session->stats.rx_packets),
801 			      L2TP_ATTR_STATS_PAD) ||
802 	    nla_put_u64_64bit(skb, L2TP_ATTR_RX_BYTES,
803 			      atomic_long_read(&session->stats.rx_bytes),
804 			      L2TP_ATTR_STATS_PAD) ||
805 	    nla_put_u64_64bit(skb, L2TP_ATTR_RX_SEQ_DISCARDS,
806 			      atomic_long_read(&session->stats.rx_seq_discards),
807 			      L2TP_ATTR_STATS_PAD) ||
808 	    nla_put_u64_64bit(skb, L2TP_ATTR_RX_OOS_PACKETS,
809 			      atomic_long_read(&session->stats.rx_oos_packets),
810 			      L2TP_ATTR_STATS_PAD) ||
811 	    nla_put_u64_64bit(skb, L2TP_ATTR_RX_ERRORS,
812 			      atomic_long_read(&session->stats.rx_errors),
813 			      L2TP_ATTR_STATS_PAD))
814 		goto nla_put_failure;
815 	nla_nest_end(skb, nest);
816 
817 	genlmsg_end(skb, hdr);
818 	return 0;
819 
820  nla_put_failure:
821 	genlmsg_cancel(skb, hdr);
822 	return -1;
823 }
824 
825 static int l2tp_nl_cmd_session_get(struct sk_buff *skb, struct genl_info *info)
826 {
827 	struct l2tp_session *session;
828 	struct sk_buff *msg;
829 	int ret;
830 
831 	session = l2tp_nl_session_get(info, false);
832 	if (session == NULL) {
833 		ret = -ENODEV;
834 		goto err;
835 	}
836 
837 	msg = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);
838 	if (!msg) {
839 		ret = -ENOMEM;
840 		goto err_ref;
841 	}
842 
843 	ret = l2tp_nl_session_send(msg, info->snd_portid, info->snd_seq,
844 				   0, session, L2TP_CMD_SESSION_GET);
845 	if (ret < 0)
846 		goto err_ref_msg;
847 
848 	ret = genlmsg_unicast(genl_info_net(info), msg, info->snd_portid);
849 
850 	l2tp_session_dec_refcount(session);
851 
852 	return ret;
853 
854 err_ref_msg:
855 	nlmsg_free(msg);
856 err_ref:
857 	l2tp_session_dec_refcount(session);
858 err:
859 	return ret;
860 }
861 
862 static int l2tp_nl_cmd_session_dump(struct sk_buff *skb, struct netlink_callback *cb)
863 {
864 	struct net *net = sock_net(skb->sk);
865 	struct l2tp_session *session;
866 	struct l2tp_tunnel *tunnel = NULL;
867 	int ti = cb->args[0];
868 	int si = cb->args[1];
869 
870 	for (;;) {
871 		if (tunnel == NULL) {
872 			tunnel = l2tp_tunnel_find_nth(net, ti);
873 			if (tunnel == NULL)
874 				goto out;
875 		}
876 
877 		session = l2tp_session_get_nth(tunnel, si, false);
878 		if (session == NULL) {
879 			ti++;
880 			tunnel = NULL;
881 			si = 0;
882 			continue;
883 		}
884 
885 		if (l2tp_nl_session_send(skb, NETLINK_CB(cb->skb).portid,
886 					 cb->nlh->nlmsg_seq, NLM_F_MULTI,
887 					 session, L2TP_CMD_SESSION_GET) < 0) {
888 			l2tp_session_dec_refcount(session);
889 			break;
890 		}
891 		l2tp_session_dec_refcount(session);
892 
893 		si++;
894 	}
895 
896 out:
897 	cb->args[0] = ti;
898 	cb->args[1] = si;
899 
900 	return skb->len;
901 }
902 
903 static const struct nla_policy l2tp_nl_policy[L2TP_ATTR_MAX + 1] = {
904 	[L2TP_ATTR_NONE]		= { .type = NLA_UNSPEC, },
905 	[L2TP_ATTR_PW_TYPE]		= { .type = NLA_U16, },
906 	[L2TP_ATTR_ENCAP_TYPE]		= { .type = NLA_U16, },
907 	[L2TP_ATTR_OFFSET]		= { .type = NLA_U16, },
908 	[L2TP_ATTR_DATA_SEQ]		= { .type = NLA_U8, },
909 	[L2TP_ATTR_L2SPEC_TYPE]		= { .type = NLA_U8, },
910 	[L2TP_ATTR_L2SPEC_LEN]		= { .type = NLA_U8, },
911 	[L2TP_ATTR_PROTO_VERSION]	= { .type = NLA_U8, },
912 	[L2TP_ATTR_CONN_ID]		= { .type = NLA_U32, },
913 	[L2TP_ATTR_PEER_CONN_ID]	= { .type = NLA_U32, },
914 	[L2TP_ATTR_SESSION_ID]		= { .type = NLA_U32, },
915 	[L2TP_ATTR_PEER_SESSION_ID]	= { .type = NLA_U32, },
916 	[L2TP_ATTR_UDP_CSUM]		= { .type = NLA_U8, },
917 	[L2TP_ATTR_VLAN_ID]		= { .type = NLA_U16, },
918 	[L2TP_ATTR_DEBUG]		= { .type = NLA_U32, },
919 	[L2TP_ATTR_RECV_SEQ]		= { .type = NLA_U8, },
920 	[L2TP_ATTR_SEND_SEQ]		= { .type = NLA_U8, },
921 	[L2TP_ATTR_LNS_MODE]		= { .type = NLA_U8, },
922 	[L2TP_ATTR_USING_IPSEC]		= { .type = NLA_U8, },
923 	[L2TP_ATTR_RECV_TIMEOUT]	= { .type = NLA_MSECS, },
924 	[L2TP_ATTR_FD]			= { .type = NLA_U32, },
925 	[L2TP_ATTR_IP_SADDR]		= { .type = NLA_U32, },
926 	[L2TP_ATTR_IP_DADDR]		= { .type = NLA_U32, },
927 	[L2TP_ATTR_UDP_SPORT]		= { .type = NLA_U16, },
928 	[L2TP_ATTR_UDP_DPORT]		= { .type = NLA_U16, },
929 	[L2TP_ATTR_MTU]			= { .type = NLA_U16, },
930 	[L2TP_ATTR_MRU]			= { .type = NLA_U16, },
931 	[L2TP_ATTR_STATS]		= { .type = NLA_NESTED, },
932 	[L2TP_ATTR_IP6_SADDR] = {
933 		.type = NLA_BINARY,
934 		.len = sizeof(struct in6_addr),
935 	},
936 	[L2TP_ATTR_IP6_DADDR] = {
937 		.type = NLA_BINARY,
938 		.len = sizeof(struct in6_addr),
939 	},
940 	[L2TP_ATTR_IFNAME] = {
941 		.type = NLA_NUL_STRING,
942 		.len = IFNAMSIZ - 1,
943 	},
944 	[L2TP_ATTR_COOKIE] = {
945 		.type = NLA_BINARY,
946 		.len = 8,
947 	},
948 	[L2TP_ATTR_PEER_COOKIE] = {
949 		.type = NLA_BINARY,
950 		.len = 8,
951 	},
952 };
953 
954 static const struct genl_ops l2tp_nl_ops[] = {
955 	{
956 		.cmd = L2TP_CMD_NOOP,
957 		.doit = l2tp_nl_cmd_noop,
958 		.policy = l2tp_nl_policy,
959 		/* can be retrieved by unprivileged users */
960 	},
961 	{
962 		.cmd = L2TP_CMD_TUNNEL_CREATE,
963 		.doit = l2tp_nl_cmd_tunnel_create,
964 		.policy = l2tp_nl_policy,
965 		.flags = GENL_ADMIN_PERM,
966 	},
967 	{
968 		.cmd = L2TP_CMD_TUNNEL_DELETE,
969 		.doit = l2tp_nl_cmd_tunnel_delete,
970 		.policy = l2tp_nl_policy,
971 		.flags = GENL_ADMIN_PERM,
972 	},
973 	{
974 		.cmd = L2TP_CMD_TUNNEL_MODIFY,
975 		.doit = l2tp_nl_cmd_tunnel_modify,
976 		.policy = l2tp_nl_policy,
977 		.flags = GENL_ADMIN_PERM,
978 	},
979 	{
980 		.cmd = L2TP_CMD_TUNNEL_GET,
981 		.doit = l2tp_nl_cmd_tunnel_get,
982 		.dumpit = l2tp_nl_cmd_tunnel_dump,
983 		.policy = l2tp_nl_policy,
984 		.flags = GENL_ADMIN_PERM,
985 	},
986 	{
987 		.cmd = L2TP_CMD_SESSION_CREATE,
988 		.doit = l2tp_nl_cmd_session_create,
989 		.policy = l2tp_nl_policy,
990 		.flags = GENL_ADMIN_PERM,
991 	},
992 	{
993 		.cmd = L2TP_CMD_SESSION_DELETE,
994 		.doit = l2tp_nl_cmd_session_delete,
995 		.policy = l2tp_nl_policy,
996 		.flags = GENL_ADMIN_PERM,
997 	},
998 	{
999 		.cmd = L2TP_CMD_SESSION_MODIFY,
1000 		.doit = l2tp_nl_cmd_session_modify,
1001 		.policy = l2tp_nl_policy,
1002 		.flags = GENL_ADMIN_PERM,
1003 	},
1004 	{
1005 		.cmd = L2TP_CMD_SESSION_GET,
1006 		.doit = l2tp_nl_cmd_session_get,
1007 		.dumpit = l2tp_nl_cmd_session_dump,
1008 		.policy = l2tp_nl_policy,
1009 		.flags = GENL_ADMIN_PERM,
1010 	},
1011 };
1012 
1013 static struct genl_family l2tp_nl_family __ro_after_init = {
1014 	.name		= L2TP_GENL_NAME,
1015 	.version	= L2TP_GENL_VERSION,
1016 	.hdrsize	= 0,
1017 	.maxattr	= L2TP_ATTR_MAX,
1018 	.netnsok	= true,
1019 	.module		= THIS_MODULE,
1020 	.ops		= l2tp_nl_ops,
1021 	.n_ops		= ARRAY_SIZE(l2tp_nl_ops),
1022 	.mcgrps		= l2tp_multicast_group,
1023 	.n_mcgrps	= ARRAY_SIZE(l2tp_multicast_group),
1024 };
1025 
1026 int l2tp_nl_register_ops(enum l2tp_pwtype pw_type, const struct l2tp_nl_cmd_ops *ops)
1027 {
1028 	int ret;
1029 
1030 	ret = -EINVAL;
1031 	if (pw_type >= __L2TP_PWTYPE_MAX)
1032 		goto err;
1033 
1034 	genl_lock();
1035 	ret = -EBUSY;
1036 	if (l2tp_nl_cmd_ops[pw_type])
1037 		goto out;
1038 
1039 	l2tp_nl_cmd_ops[pw_type] = ops;
1040 	ret = 0;
1041 
1042 out:
1043 	genl_unlock();
1044 err:
1045 	return ret;
1046 }
1047 EXPORT_SYMBOL_GPL(l2tp_nl_register_ops);
1048 
1049 void l2tp_nl_unregister_ops(enum l2tp_pwtype pw_type)
1050 {
1051 	if (pw_type < __L2TP_PWTYPE_MAX) {
1052 		genl_lock();
1053 		l2tp_nl_cmd_ops[pw_type] = NULL;
1054 		genl_unlock();
1055 	}
1056 }
1057 EXPORT_SYMBOL_GPL(l2tp_nl_unregister_ops);
1058 
1059 static int __init l2tp_nl_init(void)
1060 {
1061 	pr_info("L2TP netlink interface\n");
1062 	return genl_register_family(&l2tp_nl_family);
1063 }
1064 
1065 static void l2tp_nl_cleanup(void)
1066 {
1067 	genl_unregister_family(&l2tp_nl_family);
1068 }
1069 
1070 module_init(l2tp_nl_init);
1071 module_exit(l2tp_nl_cleanup);
1072 
1073 MODULE_AUTHOR("James Chapman <jchapman@katalix.com>");
1074 MODULE_DESCRIPTION("L2TP netlink");
1075 MODULE_LICENSE("GPL");
1076 MODULE_VERSION("1.0");
1077 MODULE_ALIAS_GENL_FAMILY("l2tp");
1078