xref: /openbmc/linux/net/l2tp/l2tp_netlink.c (revision 9dae47aba0a055f761176d9297371d5bb24289ec) 
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 {
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_get_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_get(net, tunnel_id);
68 		if (tunnel) {
69 			session = l2tp_session_get(net, tunnel, session_id);
70 			l2tp_tunnel_dec_refcount(tunnel);
71 		}
72 	}
73 
74 	return session;
75 }
76 
77 static int l2tp_nl_cmd_noop(struct sk_buff *skb, struct genl_info *info)
78 {
79 	struct sk_buff *msg;
80 	void *hdr;
81 	int ret = -ENOBUFS;
82 
83 	msg = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);
84 	if (!msg) {
85 		ret = -ENOMEM;
86 		goto out;
87 	}
88 
89 	hdr = genlmsg_put(msg, info->snd_portid, info->snd_seq,
90 			  &l2tp_nl_family, 0, L2TP_CMD_NOOP);
91 	if (!hdr) {
92 		ret = -EMSGSIZE;
93 		goto err_out;
94 	}
95 
96 	genlmsg_end(msg, hdr);
97 
98 	return genlmsg_unicast(genl_info_net(info), msg, info->snd_portid);
99 
100 err_out:
101 	nlmsg_free(msg);
102 
103 out:
104 	return ret;
105 }
106 
107 static int l2tp_tunnel_notify(struct genl_family *family,
108 			      struct genl_info *info,
109 			      struct l2tp_tunnel *tunnel,
110 			      u8 cmd)
111 {
112 	struct sk_buff *msg;
113 	int ret;
114 
115 	msg = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);
116 	if (!msg)
117 		return -ENOMEM;
118 
119 	ret = l2tp_nl_tunnel_send(msg, info->snd_portid, info->snd_seq,
120 				  NLM_F_ACK, tunnel, cmd);
121 
122 	if (ret >= 0) {
123 		ret = genlmsg_multicast_allns(family, msg, 0, 0, GFP_ATOMIC);
124 		/* We don't care if no one is listening */
125 		if (ret == -ESRCH)
126 			ret = 0;
127 		return ret;
128 	}
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 		ret = genlmsg_multicast_allns(family, msg, 0, 0, GFP_ATOMIC);
152 		/* We don't care if no one is listening */
153 		if (ret == -ESRCH)
154 			ret = 0;
155 		return ret;
156 	}
157 
158 	nlmsg_free(msg);
159 
160 	return ret;
161 }
162 
163 static int l2tp_nl_cmd_tunnel_create(struct sk_buff *skb, struct genl_info *info)
164 {
165 	u32 tunnel_id;
166 	u32 peer_tunnel_id;
167 	int proto_version;
168 	int fd;
169 	int ret = 0;
170 	struct l2tp_tunnel_cfg cfg = { 0, };
171 	struct l2tp_tunnel *tunnel;
172 	struct net *net = genl_info_net(info);
173 
174 	if (!info->attrs[L2TP_ATTR_CONN_ID]) {
175 		ret = -EINVAL;
176 		goto out;
177 	}
178 	tunnel_id = nla_get_u32(info->attrs[L2TP_ATTR_CONN_ID]);
179 
180 	if (!info->attrs[L2TP_ATTR_PEER_CONN_ID]) {
181 		ret = -EINVAL;
182 		goto out;
183 	}
184 	peer_tunnel_id = nla_get_u32(info->attrs[L2TP_ATTR_PEER_CONN_ID]);
185 
186 	if (!info->attrs[L2TP_ATTR_PROTO_VERSION]) {
187 		ret = -EINVAL;
188 		goto out;
189 	}
190 	proto_version = nla_get_u8(info->attrs[L2TP_ATTR_PROTO_VERSION]);
191 
192 	if (!info->attrs[L2TP_ATTR_ENCAP_TYPE]) {
193 		ret = -EINVAL;
194 		goto out;
195 	}
196 	cfg.encap = nla_get_u16(info->attrs[L2TP_ATTR_ENCAP_TYPE]);
197 
198 	fd = -1;
199 	if (info->attrs[L2TP_ATTR_FD]) {
200 		fd = nla_get_u32(info->attrs[L2TP_ATTR_FD]);
201 	} else {
202 #if IS_ENABLED(CONFIG_IPV6)
203 		if (info->attrs[L2TP_ATTR_IP6_SADDR] &&
204 		    info->attrs[L2TP_ATTR_IP6_DADDR]) {
205 			cfg.local_ip6 = nla_data(
206 				info->attrs[L2TP_ATTR_IP6_SADDR]);
207 			cfg.peer_ip6 = nla_data(
208 				info->attrs[L2TP_ATTR_IP6_DADDR]);
209 		} else
210 #endif
211 		if (info->attrs[L2TP_ATTR_IP_SADDR] &&
212 		    info->attrs[L2TP_ATTR_IP_DADDR]) {
213 			cfg.local_ip.s_addr = nla_get_in_addr(
214 				info->attrs[L2TP_ATTR_IP_SADDR]);
215 			cfg.peer_ip.s_addr = nla_get_in_addr(
216 				info->attrs[L2TP_ATTR_IP_DADDR]);
217 		} else {
218 			ret = -EINVAL;
219 			goto out;
220 		}
221 		if (info->attrs[L2TP_ATTR_UDP_SPORT])
222 			cfg.local_udp_port = nla_get_u16(info->attrs[L2TP_ATTR_UDP_SPORT]);
223 		if (info->attrs[L2TP_ATTR_UDP_DPORT])
224 			cfg.peer_udp_port = nla_get_u16(info->attrs[L2TP_ATTR_UDP_DPORT]);
225 		cfg.use_udp_checksums = nla_get_flag(
226 			info->attrs[L2TP_ATTR_UDP_CSUM]);
227 
228 #if IS_ENABLED(CONFIG_IPV6)
229 		cfg.udp6_zero_tx_checksums = nla_get_flag(
230 			info->attrs[L2TP_ATTR_UDP_ZERO_CSUM6_TX]);
231 		cfg.udp6_zero_rx_checksums = nla_get_flag(
232 			info->attrs[L2TP_ATTR_UDP_ZERO_CSUM6_RX]);
233 #endif
234 	}
235 
236 	if (info->attrs[L2TP_ATTR_DEBUG])
237 		cfg.debug = nla_get_u32(info->attrs[L2TP_ATTR_DEBUG]);
238 
239 	tunnel = l2tp_tunnel_find(net, tunnel_id);
240 	if (tunnel != NULL) {
241 		ret = -EEXIST;
242 		goto out;
243 	}
244 
245 	ret = -EINVAL;
246 	switch (cfg.encap) {
247 	case L2TP_ENCAPTYPE_UDP:
248 	case L2TP_ENCAPTYPE_IP:
249 		ret = l2tp_tunnel_create(net, fd, proto_version, tunnel_id,
250 					 peer_tunnel_id, &cfg, &tunnel);
251 		break;
252 	}
253 
254 	if (ret >= 0)
255 		ret = l2tp_tunnel_notify(&l2tp_nl_family, info,
256 					 tunnel, L2TP_CMD_TUNNEL_CREATE);
257 out:
258 	return ret;
259 }
260 
261 static int l2tp_nl_cmd_tunnel_delete(struct sk_buff *skb, struct genl_info *info)
262 {
263 	struct l2tp_tunnel *tunnel;
264 	u32 tunnel_id;
265 	int ret = 0;
266 	struct net *net = genl_info_net(info);
267 
268 	if (!info->attrs[L2TP_ATTR_CONN_ID]) {
269 		ret = -EINVAL;
270 		goto out;
271 	}
272 	tunnel_id = nla_get_u32(info->attrs[L2TP_ATTR_CONN_ID]);
273 
274 	tunnel = l2tp_tunnel_get(net, tunnel_id);
275 	if (!tunnel) {
276 		ret = -ENODEV;
277 		goto out;
278 	}
279 
280 	l2tp_tunnel_notify(&l2tp_nl_family, info,
281 			   tunnel, L2TP_CMD_TUNNEL_DELETE);
282 
283 	l2tp_tunnel_delete(tunnel);
284 
285 	l2tp_tunnel_dec_refcount(tunnel);
286 
287 out:
288 	return ret;
289 }
290 
291 static int l2tp_nl_cmd_tunnel_modify(struct sk_buff *skb, struct genl_info *info)
292 {
293 	struct l2tp_tunnel *tunnel;
294 	u32 tunnel_id;
295 	int ret = 0;
296 	struct net *net = genl_info_net(info);
297 
298 	if (!info->attrs[L2TP_ATTR_CONN_ID]) {
299 		ret = -EINVAL;
300 		goto out;
301 	}
302 	tunnel_id = nla_get_u32(info->attrs[L2TP_ATTR_CONN_ID]);
303 
304 	tunnel = l2tp_tunnel_get(net, tunnel_id);
305 	if (!tunnel) {
306 		ret = -ENODEV;
307 		goto out;
308 	}
309 
310 	if (info->attrs[L2TP_ATTR_DEBUG])
311 		tunnel->debug = nla_get_u32(info->attrs[L2TP_ATTR_DEBUG]);
312 
313 	ret = l2tp_tunnel_notify(&l2tp_nl_family, info,
314 				 tunnel, L2TP_CMD_TUNNEL_MODIFY);
315 
316 	l2tp_tunnel_dec_refcount(tunnel);
317 
318 out:
319 	return ret;
320 }
321 
322 static int l2tp_nl_tunnel_send(struct sk_buff *skb, u32 portid, u32 seq, int flags,
323 			       struct l2tp_tunnel *tunnel, u8 cmd)
324 {
325 	void *hdr;
326 	struct nlattr *nest;
327 	struct sock *sk = NULL;
328 	struct inet_sock *inet;
329 #if IS_ENABLED(CONFIG_IPV6)
330 	struct ipv6_pinfo *np = NULL;
331 #endif
332 
333 	hdr = genlmsg_put(skb, portid, seq, &l2tp_nl_family, flags, cmd);
334 	if (!hdr)
335 		return -EMSGSIZE;
336 
337 	if (nla_put_u8(skb, L2TP_ATTR_PROTO_VERSION, tunnel->version) ||
338 	    nla_put_u32(skb, L2TP_ATTR_CONN_ID, tunnel->tunnel_id) ||
339 	    nla_put_u32(skb, L2TP_ATTR_PEER_CONN_ID, tunnel->peer_tunnel_id) ||
340 	    nla_put_u32(skb, L2TP_ATTR_DEBUG, tunnel->debug) ||
341 	    nla_put_u16(skb, L2TP_ATTR_ENCAP_TYPE, tunnel->encap))
342 		goto nla_put_failure;
343 
344 	nest = nla_nest_start(skb, L2TP_ATTR_STATS);
345 	if (nest == NULL)
346 		goto nla_put_failure;
347 
348 	if (nla_put_u64_64bit(skb, L2TP_ATTR_TX_PACKETS,
349 			      atomic_long_read(&tunnel->stats.tx_packets),
350 			      L2TP_ATTR_STATS_PAD) ||
351 	    nla_put_u64_64bit(skb, L2TP_ATTR_TX_BYTES,
352 			      atomic_long_read(&tunnel->stats.tx_bytes),
353 			      L2TP_ATTR_STATS_PAD) ||
354 	    nla_put_u64_64bit(skb, L2TP_ATTR_TX_ERRORS,
355 			      atomic_long_read(&tunnel->stats.tx_errors),
356 			      L2TP_ATTR_STATS_PAD) ||
357 	    nla_put_u64_64bit(skb, L2TP_ATTR_RX_PACKETS,
358 			      atomic_long_read(&tunnel->stats.rx_packets),
359 			      L2TP_ATTR_STATS_PAD) ||
360 	    nla_put_u64_64bit(skb, L2TP_ATTR_RX_BYTES,
361 			      atomic_long_read(&tunnel->stats.rx_bytes),
362 			      L2TP_ATTR_STATS_PAD) ||
363 	    nla_put_u64_64bit(skb, L2TP_ATTR_RX_SEQ_DISCARDS,
364 			      atomic_long_read(&tunnel->stats.rx_seq_discards),
365 			      L2TP_ATTR_STATS_PAD) ||
366 	    nla_put_u64_64bit(skb, L2TP_ATTR_RX_OOS_PACKETS,
367 			      atomic_long_read(&tunnel->stats.rx_oos_packets),
368 			      L2TP_ATTR_STATS_PAD) ||
369 	    nla_put_u64_64bit(skb, L2TP_ATTR_RX_ERRORS,
370 			      atomic_long_read(&tunnel->stats.rx_errors),
371 			      L2TP_ATTR_STATS_PAD))
372 		goto nla_put_failure;
373 	nla_nest_end(skb, nest);
374 
375 	sk = tunnel->sock;
376 	if (!sk)
377 		goto out;
378 
379 #if IS_ENABLED(CONFIG_IPV6)
380 	if (sk->sk_family == AF_INET6)
381 		np = inet6_sk(sk);
382 #endif
383 
384 	inet = inet_sk(sk);
385 
386 	switch (tunnel->encap) {
387 	case L2TP_ENCAPTYPE_UDP:
388 		switch (sk->sk_family) {
389 		case AF_INET:
390 			if (nla_put_u8(skb, L2TP_ATTR_UDP_CSUM, !sk->sk_no_check_tx))
391 				goto nla_put_failure;
392 			break;
393 #if IS_ENABLED(CONFIG_IPV6)
394 		case AF_INET6:
395 			if (udp_get_no_check6_tx(sk) &&
396 			    nla_put_flag(skb, L2TP_ATTR_UDP_ZERO_CSUM6_TX))
397 				goto nla_put_failure;
398 			if (udp_get_no_check6_rx(sk) &&
399 			    nla_put_flag(skb, L2TP_ATTR_UDP_ZERO_CSUM6_RX))
400 				goto nla_put_failure;
401 			break;
402 #endif
403 		}
404 		if (nla_put_u16(skb, L2TP_ATTR_UDP_SPORT, ntohs(inet->inet_sport)) ||
405 		    nla_put_u16(skb, L2TP_ATTR_UDP_DPORT, ntohs(inet->inet_dport)))
406 			goto nla_put_failure;
407 		/* fall through  */
408 	case L2TP_ENCAPTYPE_IP:
409 #if IS_ENABLED(CONFIG_IPV6)
410 		if (np) {
411 			if (nla_put_in6_addr(skb, L2TP_ATTR_IP6_SADDR,
412 					     &np->saddr) ||
413 			    nla_put_in6_addr(skb, L2TP_ATTR_IP6_DADDR,
414 					     &sk->sk_v6_daddr))
415 				goto nla_put_failure;
416 		} else
417 #endif
418 		if (nla_put_in_addr(skb, L2TP_ATTR_IP_SADDR,
419 				    inet->inet_saddr) ||
420 		    nla_put_in_addr(skb, L2TP_ATTR_IP_DADDR,
421 				    inet->inet_daddr))
422 			goto nla_put_failure;
423 		break;
424 	}
425 
426 out:
427 	genlmsg_end(skb, hdr);
428 	return 0;
429 
430 nla_put_failure:
431 	genlmsg_cancel(skb, hdr);
432 	return -1;
433 }
434 
435 static int l2tp_nl_cmd_tunnel_get(struct sk_buff *skb, struct genl_info *info)
436 {
437 	struct l2tp_tunnel *tunnel;
438 	struct sk_buff *msg;
439 	u32 tunnel_id;
440 	int ret = -ENOBUFS;
441 	struct net *net = genl_info_net(info);
442 
443 	if (!info->attrs[L2TP_ATTR_CONN_ID]) {
444 		ret = -EINVAL;
445 		goto err;
446 	}
447 
448 	tunnel_id = nla_get_u32(info->attrs[L2TP_ATTR_CONN_ID]);
449 
450 	msg = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);
451 	if (!msg) {
452 		ret = -ENOMEM;
453 		goto err;
454 	}
455 
456 	tunnel = l2tp_tunnel_get(net, tunnel_id);
457 	if (!tunnel) {
458 		ret = -ENODEV;
459 		goto err_nlmsg;
460 	}
461 
462 	ret = l2tp_nl_tunnel_send(msg, info->snd_portid, info->snd_seq,
463 				  NLM_F_ACK, tunnel, L2TP_CMD_TUNNEL_GET);
464 	if (ret < 0)
465 		goto err_nlmsg_tunnel;
466 
467 	l2tp_tunnel_dec_refcount(tunnel);
468 
469 	return genlmsg_unicast(net, msg, info->snd_portid);
470 
471 err_nlmsg_tunnel:
472 	l2tp_tunnel_dec_refcount(tunnel);
473 err_nlmsg:
474 	nlmsg_free(msg);
475 err:
476 	return ret;
477 }
478 
479 static int l2tp_nl_cmd_tunnel_dump(struct sk_buff *skb, struct netlink_callback *cb)
480 {
481 	int ti = cb->args[0];
482 	struct l2tp_tunnel *tunnel;
483 	struct net *net = sock_net(skb->sk);
484 
485 	for (;;) {
486 		tunnel = l2tp_tunnel_find_nth(net, ti);
487 		if (tunnel == NULL)
488 			goto out;
489 
490 		if (l2tp_nl_tunnel_send(skb, NETLINK_CB(cb->skb).portid,
491 					cb->nlh->nlmsg_seq, NLM_F_MULTI,
492 					tunnel, L2TP_CMD_TUNNEL_GET) < 0)
493 			goto out;
494 
495 		ti++;
496 	}
497 
498 out:
499 	cb->args[0] = ti;
500 
501 	return skb->len;
502 }
503 
504 static int l2tp_nl_cmd_session_create(struct sk_buff *skb, struct genl_info *info)
505 {
506 	u32 tunnel_id = 0;
507 	u32 session_id;
508 	u32 peer_session_id;
509 	int ret = 0;
510 	struct l2tp_tunnel *tunnel;
511 	struct l2tp_session *session;
512 	struct l2tp_session_cfg cfg = { 0, };
513 	struct net *net = genl_info_net(info);
514 
515 	if (!info->attrs[L2TP_ATTR_CONN_ID]) {
516 		ret = -EINVAL;
517 		goto out;
518 	}
519 
520 	tunnel_id = nla_get_u32(info->attrs[L2TP_ATTR_CONN_ID]);
521 	tunnel = l2tp_tunnel_get(net, tunnel_id);
522 	if (!tunnel) {
523 		ret = -ENODEV;
524 		goto out;
525 	}
526 
527 	if (!info->attrs[L2TP_ATTR_SESSION_ID]) {
528 		ret = -EINVAL;
529 		goto out_tunnel;
530 	}
531 	session_id = nla_get_u32(info->attrs[L2TP_ATTR_SESSION_ID]);
532 
533 	if (!info->attrs[L2TP_ATTR_PEER_SESSION_ID]) {
534 		ret = -EINVAL;
535 		goto out_tunnel;
536 	}
537 	peer_session_id = nla_get_u32(info->attrs[L2TP_ATTR_PEER_SESSION_ID]);
538 
539 	if (!info->attrs[L2TP_ATTR_PW_TYPE]) {
540 		ret = -EINVAL;
541 		goto out_tunnel;
542 	}
543 	cfg.pw_type = nla_get_u16(info->attrs[L2TP_ATTR_PW_TYPE]);
544 	if (cfg.pw_type >= __L2TP_PWTYPE_MAX) {
545 		ret = -EINVAL;
546 		goto out_tunnel;
547 	}
548 
549 	if (tunnel->version > 2) {
550 		if (info->attrs[L2TP_ATTR_DATA_SEQ])
551 			cfg.data_seq = nla_get_u8(info->attrs[L2TP_ATTR_DATA_SEQ]);
552 
553 		cfg.l2specific_type = L2TP_L2SPECTYPE_DEFAULT;
554 		if (info->attrs[L2TP_ATTR_L2SPEC_TYPE])
555 			cfg.l2specific_type = nla_get_u8(info->attrs[L2TP_ATTR_L2SPEC_TYPE]);
556 
557 		cfg.l2specific_len = 4;
558 		if (info->attrs[L2TP_ATTR_L2SPEC_LEN])
559 			cfg.l2specific_len = nla_get_u8(info->attrs[L2TP_ATTR_L2SPEC_LEN]);
560 
561 		if (info->attrs[L2TP_ATTR_COOKIE]) {
562 			u16 len = nla_len(info->attrs[L2TP_ATTR_COOKIE]);
563 			if (len > 8) {
564 				ret = -EINVAL;
565 				goto out_tunnel;
566 			}
567 			cfg.cookie_len = len;
568 			memcpy(&cfg.cookie[0], nla_data(info->attrs[L2TP_ATTR_COOKIE]), len);
569 		}
570 		if (info->attrs[L2TP_ATTR_PEER_COOKIE]) {
571 			u16 len = nla_len(info->attrs[L2TP_ATTR_PEER_COOKIE]);
572 			if (len > 8) {
573 				ret = -EINVAL;
574 				goto out_tunnel;
575 			}
576 			cfg.peer_cookie_len = len;
577 			memcpy(&cfg.peer_cookie[0], nla_data(info->attrs[L2TP_ATTR_PEER_COOKIE]), len);
578 		}
579 		if (info->attrs[L2TP_ATTR_IFNAME])
580 			cfg.ifname = nla_data(info->attrs[L2TP_ATTR_IFNAME]);
581 
582 		if (info->attrs[L2TP_ATTR_VLAN_ID])
583 			cfg.vlan_id = nla_get_u16(info->attrs[L2TP_ATTR_VLAN_ID]);
584 	}
585 
586 	if (info->attrs[L2TP_ATTR_DEBUG])
587 		cfg.debug = nla_get_u32(info->attrs[L2TP_ATTR_DEBUG]);
588 
589 	if (info->attrs[L2TP_ATTR_RECV_SEQ])
590 		cfg.recv_seq = nla_get_u8(info->attrs[L2TP_ATTR_RECV_SEQ]);
591 
592 	if (info->attrs[L2TP_ATTR_SEND_SEQ])
593 		cfg.send_seq = nla_get_u8(info->attrs[L2TP_ATTR_SEND_SEQ]);
594 
595 	if (info->attrs[L2TP_ATTR_LNS_MODE])
596 		cfg.lns_mode = nla_get_u8(info->attrs[L2TP_ATTR_LNS_MODE]);
597 
598 	if (info->attrs[L2TP_ATTR_RECV_TIMEOUT])
599 		cfg.reorder_timeout = nla_get_msecs(info->attrs[L2TP_ATTR_RECV_TIMEOUT]);
600 
601 	if (info->attrs[L2TP_ATTR_MTU])
602 		cfg.mtu = nla_get_u16(info->attrs[L2TP_ATTR_MTU]);
603 
604 	if (info->attrs[L2TP_ATTR_MRU])
605 		cfg.mru = nla_get_u16(info->attrs[L2TP_ATTR_MRU]);
606 
607 #ifdef CONFIG_MODULES
608 	if (l2tp_nl_cmd_ops[cfg.pw_type] == NULL) {
609 		genl_unlock();
610 		request_module("net-l2tp-type-%u", cfg.pw_type);
611 		genl_lock();
612 	}
613 #endif
614 	if ((l2tp_nl_cmd_ops[cfg.pw_type] == NULL) ||
615 	    (l2tp_nl_cmd_ops[cfg.pw_type]->session_create == NULL)) {
616 		ret = -EPROTONOSUPPORT;
617 		goto out_tunnel;
618 	}
619 
620 	/* Check that pseudowire-specific params are present */
621 	switch (cfg.pw_type) {
622 	case L2TP_PWTYPE_NONE:
623 		break;
624 	case L2TP_PWTYPE_ETH_VLAN:
625 		if (!info->attrs[L2TP_ATTR_VLAN_ID]) {
626 			ret = -EINVAL;
627 			goto out_tunnel;
628 		}
629 		break;
630 	case L2TP_PWTYPE_ETH:
631 		break;
632 	case L2TP_PWTYPE_PPP:
633 	case L2TP_PWTYPE_PPP_AC:
634 		break;
635 	case L2TP_PWTYPE_IP:
636 	default:
637 		ret = -EPROTONOSUPPORT;
638 		break;
639 	}
640 
641 	ret = l2tp_nl_cmd_ops[cfg.pw_type]->session_create(net, tunnel,
642 							   session_id,
643 							   peer_session_id,
644 							   &cfg);
645 
646 	if (ret >= 0) {
647 		session = l2tp_session_get(net, tunnel, session_id);
648 		if (session) {
649 			ret = l2tp_session_notify(&l2tp_nl_family, info, session,
650 						  L2TP_CMD_SESSION_CREATE);
651 			l2tp_session_dec_refcount(session);
652 		}
653 	}
654 
655 out_tunnel:
656 	l2tp_tunnel_dec_refcount(tunnel);
657 out:
658 	return ret;
659 }
660 
661 static int l2tp_nl_cmd_session_delete(struct sk_buff *skb, struct genl_info *info)
662 {
663 	int ret = 0;
664 	struct l2tp_session *session;
665 	u16 pw_type;
666 
667 	session = l2tp_nl_session_get(info);
668 	if (session == NULL) {
669 		ret = -ENODEV;
670 		goto out;
671 	}
672 
673 	l2tp_session_notify(&l2tp_nl_family, info,
674 			    session, L2TP_CMD_SESSION_DELETE);
675 
676 	pw_type = session->pwtype;
677 	if (pw_type < __L2TP_PWTYPE_MAX)
678 		if (l2tp_nl_cmd_ops[pw_type] && l2tp_nl_cmd_ops[pw_type]->session_delete)
679 			ret = (*l2tp_nl_cmd_ops[pw_type]->session_delete)(session);
680 
681 	l2tp_session_dec_refcount(session);
682 
683 out:
684 	return ret;
685 }
686 
687 static int l2tp_nl_cmd_session_modify(struct sk_buff *skb, struct genl_info *info)
688 {
689 	int ret = 0;
690 	struct l2tp_session *session;
691 
692 	session = l2tp_nl_session_get(info);
693 	if (session == NULL) {
694 		ret = -ENODEV;
695 		goto out;
696 	}
697 
698 	if (info->attrs[L2TP_ATTR_DEBUG])
699 		session->debug = nla_get_u32(info->attrs[L2TP_ATTR_DEBUG]);
700 
701 	if (info->attrs[L2TP_ATTR_DATA_SEQ])
702 		session->data_seq = nla_get_u8(info->attrs[L2TP_ATTR_DATA_SEQ]);
703 
704 	if (info->attrs[L2TP_ATTR_RECV_SEQ])
705 		session->recv_seq = nla_get_u8(info->attrs[L2TP_ATTR_RECV_SEQ]);
706 
707 	if (info->attrs[L2TP_ATTR_SEND_SEQ]) {
708 		session->send_seq = nla_get_u8(info->attrs[L2TP_ATTR_SEND_SEQ]);
709 		l2tp_session_set_header_len(session, session->tunnel->version);
710 	}
711 
712 	if (info->attrs[L2TP_ATTR_LNS_MODE])
713 		session->lns_mode = nla_get_u8(info->attrs[L2TP_ATTR_LNS_MODE]);
714 
715 	if (info->attrs[L2TP_ATTR_RECV_TIMEOUT])
716 		session->reorder_timeout = nla_get_msecs(info->attrs[L2TP_ATTR_RECV_TIMEOUT]);
717 
718 	if (info->attrs[L2TP_ATTR_MTU])
719 		session->mtu = nla_get_u16(info->attrs[L2TP_ATTR_MTU]);
720 
721 	if (info->attrs[L2TP_ATTR_MRU])
722 		session->mru = nla_get_u16(info->attrs[L2TP_ATTR_MRU]);
723 
724 	ret = l2tp_session_notify(&l2tp_nl_family, info,
725 				  session, L2TP_CMD_SESSION_MODIFY);
726 
727 	l2tp_session_dec_refcount(session);
728 
729 out:
730 	return ret;
731 }
732 
733 static int l2tp_nl_session_send(struct sk_buff *skb, u32 portid, u32 seq, int flags,
734 				struct l2tp_session *session, u8 cmd)
735 {
736 	void *hdr;
737 	struct nlattr *nest;
738 	struct l2tp_tunnel *tunnel = session->tunnel;
739 	struct sock *sk = NULL;
740 
741 	sk = tunnel->sock;
742 
743 	hdr = genlmsg_put(skb, portid, seq, &l2tp_nl_family, flags, cmd);
744 	if (!hdr)
745 		return -EMSGSIZE;
746 
747 	if (nla_put_u32(skb, L2TP_ATTR_CONN_ID, tunnel->tunnel_id) ||
748 	    nla_put_u32(skb, L2TP_ATTR_SESSION_ID, session->session_id) ||
749 	    nla_put_u32(skb, L2TP_ATTR_PEER_CONN_ID, tunnel->peer_tunnel_id) ||
750 	    nla_put_u32(skb, L2TP_ATTR_PEER_SESSION_ID,
751 			session->peer_session_id) ||
752 	    nla_put_u32(skb, L2TP_ATTR_DEBUG, session->debug) ||
753 	    nla_put_u16(skb, L2TP_ATTR_PW_TYPE, session->pwtype) ||
754 	    nla_put_u16(skb, L2TP_ATTR_MTU, session->mtu) ||
755 	    (session->mru &&
756 	     nla_put_u16(skb, L2TP_ATTR_MRU, session->mru)))
757 		goto nla_put_failure;
758 
759 	if ((session->ifname[0] &&
760 	     nla_put_string(skb, L2TP_ATTR_IFNAME, session->ifname)) ||
761 	    (session->cookie_len &&
762 	     nla_put(skb, L2TP_ATTR_COOKIE, session->cookie_len,
763 		     &session->cookie[0])) ||
764 	    (session->peer_cookie_len &&
765 	     nla_put(skb, L2TP_ATTR_PEER_COOKIE, session->peer_cookie_len,
766 		     &session->peer_cookie[0])) ||
767 	    nla_put_u8(skb, L2TP_ATTR_RECV_SEQ, session->recv_seq) ||
768 	    nla_put_u8(skb, L2TP_ATTR_SEND_SEQ, session->send_seq) ||
769 	    nla_put_u8(skb, L2TP_ATTR_LNS_MODE, session->lns_mode) ||
770 #ifdef CONFIG_XFRM
771 	    (((sk) && (sk->sk_policy[0] || sk->sk_policy[1])) &&
772 	     nla_put_u8(skb, L2TP_ATTR_USING_IPSEC, 1)) ||
773 #endif
774 	    (session->reorder_timeout &&
775 	     nla_put_msecs(skb, L2TP_ATTR_RECV_TIMEOUT,
776 			   session->reorder_timeout, L2TP_ATTR_PAD)))
777 		goto nla_put_failure;
778 
779 	nest = nla_nest_start(skb, L2TP_ATTR_STATS);
780 	if (nest == NULL)
781 		goto nla_put_failure;
782 
783 	if (nla_put_u64_64bit(skb, L2TP_ATTR_TX_PACKETS,
784 			      atomic_long_read(&session->stats.tx_packets),
785 			      L2TP_ATTR_STATS_PAD) ||
786 	    nla_put_u64_64bit(skb, L2TP_ATTR_TX_BYTES,
787 			      atomic_long_read(&session->stats.tx_bytes),
788 			      L2TP_ATTR_STATS_PAD) ||
789 	    nla_put_u64_64bit(skb, L2TP_ATTR_TX_ERRORS,
790 			      atomic_long_read(&session->stats.tx_errors),
791 			      L2TP_ATTR_STATS_PAD) ||
792 	    nla_put_u64_64bit(skb, L2TP_ATTR_RX_PACKETS,
793 			      atomic_long_read(&session->stats.rx_packets),
794 			      L2TP_ATTR_STATS_PAD) ||
795 	    nla_put_u64_64bit(skb, L2TP_ATTR_RX_BYTES,
796 			      atomic_long_read(&session->stats.rx_bytes),
797 			      L2TP_ATTR_STATS_PAD) ||
798 	    nla_put_u64_64bit(skb, L2TP_ATTR_RX_SEQ_DISCARDS,
799 			      atomic_long_read(&session->stats.rx_seq_discards),
800 			      L2TP_ATTR_STATS_PAD) ||
801 	    nla_put_u64_64bit(skb, L2TP_ATTR_RX_OOS_PACKETS,
802 			      atomic_long_read(&session->stats.rx_oos_packets),
803 			      L2TP_ATTR_STATS_PAD) ||
804 	    nla_put_u64_64bit(skb, L2TP_ATTR_RX_ERRORS,
805 			      atomic_long_read(&session->stats.rx_errors),
806 			      L2TP_ATTR_STATS_PAD))
807 		goto nla_put_failure;
808 	nla_nest_end(skb, nest);
809 
810 	genlmsg_end(skb, hdr);
811 	return 0;
812 
813  nla_put_failure:
814 	genlmsg_cancel(skb, hdr);
815 	return -1;
816 }
817 
818 static int l2tp_nl_cmd_session_get(struct sk_buff *skb, struct genl_info *info)
819 {
820 	struct l2tp_session *session;
821 	struct sk_buff *msg;
822 	int ret;
823 
824 	session = l2tp_nl_session_get(info);
825 	if (session == NULL) {
826 		ret = -ENODEV;
827 		goto err;
828 	}
829 
830 	msg = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);
831 	if (!msg) {
832 		ret = -ENOMEM;
833 		goto err_ref;
834 	}
835 
836 	ret = l2tp_nl_session_send(msg, info->snd_portid, info->snd_seq,
837 				   0, session, L2TP_CMD_SESSION_GET);
838 	if (ret < 0)
839 		goto err_ref_msg;
840 
841 	ret = genlmsg_unicast(genl_info_net(info), msg, info->snd_portid);
842 
843 	l2tp_session_dec_refcount(session);
844 
845 	return ret;
846 
847 err_ref_msg:
848 	nlmsg_free(msg);
849 err_ref:
850 	l2tp_session_dec_refcount(session);
851 err:
852 	return ret;
853 }
854 
855 static int l2tp_nl_cmd_session_dump(struct sk_buff *skb, struct netlink_callback *cb)
856 {
857 	struct net *net = sock_net(skb->sk);
858 	struct l2tp_session *session;
859 	struct l2tp_tunnel *tunnel = NULL;
860 	int ti = cb->args[0];
861 	int si = cb->args[1];
862 
863 	for (;;) {
864 		if (tunnel == NULL) {
865 			tunnel = l2tp_tunnel_find_nth(net, ti);
866 			if (tunnel == NULL)
867 				goto out;
868 		}
869 
870 		session = l2tp_session_get_nth(tunnel, si);
871 		if (session == NULL) {
872 			ti++;
873 			tunnel = NULL;
874 			si = 0;
875 			continue;
876 		}
877 
878 		if (l2tp_nl_session_send(skb, NETLINK_CB(cb->skb).portid,
879 					 cb->nlh->nlmsg_seq, NLM_F_MULTI,
880 					 session, L2TP_CMD_SESSION_GET) < 0) {
881 			l2tp_session_dec_refcount(session);
882 			break;
883 		}
884 		l2tp_session_dec_refcount(session);
885 
886 		si++;
887 	}
888 
889 out:
890 	cb->args[0] = ti;
891 	cb->args[1] = si;
892 
893 	return skb->len;
894 }
895 
896 static const struct nla_policy l2tp_nl_policy[L2TP_ATTR_MAX + 1] = {
897 	[L2TP_ATTR_NONE]		= { .type = NLA_UNSPEC, },
898 	[L2TP_ATTR_PW_TYPE]		= { .type = NLA_U16, },
899 	[L2TP_ATTR_ENCAP_TYPE]		= { .type = NLA_U16, },
900 	[L2TP_ATTR_OFFSET]		= { .type = NLA_U16, },
901 	[L2TP_ATTR_DATA_SEQ]		= { .type = NLA_U8, },
902 	[L2TP_ATTR_L2SPEC_TYPE]		= { .type = NLA_U8, },
903 	[L2TP_ATTR_L2SPEC_LEN]		= { .type = NLA_U8, },
904 	[L2TP_ATTR_PROTO_VERSION]	= { .type = NLA_U8, },
905 	[L2TP_ATTR_CONN_ID]		= { .type = NLA_U32, },
906 	[L2TP_ATTR_PEER_CONN_ID]	= { .type = NLA_U32, },
907 	[L2TP_ATTR_SESSION_ID]		= { .type = NLA_U32, },
908 	[L2TP_ATTR_PEER_SESSION_ID]	= { .type = NLA_U32, },
909 	[L2TP_ATTR_UDP_CSUM]		= { .type = NLA_U8, },
910 	[L2TP_ATTR_VLAN_ID]		= { .type = NLA_U16, },
911 	[L2TP_ATTR_DEBUG]		= { .type = NLA_U32, },
912 	[L2TP_ATTR_RECV_SEQ]		= { .type = NLA_U8, },
913 	[L2TP_ATTR_SEND_SEQ]		= { .type = NLA_U8, },
914 	[L2TP_ATTR_LNS_MODE]		= { .type = NLA_U8, },
915 	[L2TP_ATTR_USING_IPSEC]		= { .type = NLA_U8, },
916 	[L2TP_ATTR_RECV_TIMEOUT]	= { .type = NLA_MSECS, },
917 	[L2TP_ATTR_FD]			= { .type = NLA_U32, },
918 	[L2TP_ATTR_IP_SADDR]		= { .type = NLA_U32, },
919 	[L2TP_ATTR_IP_DADDR]		= { .type = NLA_U32, },
920 	[L2TP_ATTR_UDP_SPORT]		= { .type = NLA_U16, },
921 	[L2TP_ATTR_UDP_DPORT]		= { .type = NLA_U16, },
922 	[L2TP_ATTR_MTU]			= { .type = NLA_U16, },
923 	[L2TP_ATTR_MRU]			= { .type = NLA_U16, },
924 	[L2TP_ATTR_STATS]		= { .type = NLA_NESTED, },
925 	[L2TP_ATTR_IP6_SADDR] = {
926 		.type = NLA_BINARY,
927 		.len = sizeof(struct in6_addr),
928 	},
929 	[L2TP_ATTR_IP6_DADDR] = {
930 		.type = NLA_BINARY,
931 		.len = sizeof(struct in6_addr),
932 	},
933 	[L2TP_ATTR_IFNAME] = {
934 		.type = NLA_NUL_STRING,
935 		.len = IFNAMSIZ - 1,
936 	},
937 	[L2TP_ATTR_COOKIE] = {
938 		.type = NLA_BINARY,
939 		.len = 8,
940 	},
941 	[L2TP_ATTR_PEER_COOKIE] = {
942 		.type = NLA_BINARY,
943 		.len = 8,
944 	},
945 };
946 
947 static const struct genl_ops l2tp_nl_ops[] = {
948 	{
949 		.cmd = L2TP_CMD_NOOP,
950 		.doit = l2tp_nl_cmd_noop,
951 		.policy = l2tp_nl_policy,
952 		/* can be retrieved by unprivileged users */
953 	},
954 	{
955 		.cmd = L2TP_CMD_TUNNEL_CREATE,
956 		.doit = l2tp_nl_cmd_tunnel_create,
957 		.policy = l2tp_nl_policy,
958 		.flags = GENL_ADMIN_PERM,
959 	},
960 	{
961 		.cmd = L2TP_CMD_TUNNEL_DELETE,
962 		.doit = l2tp_nl_cmd_tunnel_delete,
963 		.policy = l2tp_nl_policy,
964 		.flags = GENL_ADMIN_PERM,
965 	},
966 	{
967 		.cmd = L2TP_CMD_TUNNEL_MODIFY,
968 		.doit = l2tp_nl_cmd_tunnel_modify,
969 		.policy = l2tp_nl_policy,
970 		.flags = GENL_ADMIN_PERM,
971 	},
972 	{
973 		.cmd = L2TP_CMD_TUNNEL_GET,
974 		.doit = l2tp_nl_cmd_tunnel_get,
975 		.dumpit = l2tp_nl_cmd_tunnel_dump,
976 		.policy = l2tp_nl_policy,
977 		.flags = GENL_ADMIN_PERM,
978 	},
979 	{
980 		.cmd = L2TP_CMD_SESSION_CREATE,
981 		.doit = l2tp_nl_cmd_session_create,
982 		.policy = l2tp_nl_policy,
983 		.flags = GENL_ADMIN_PERM,
984 	},
985 	{
986 		.cmd = L2TP_CMD_SESSION_DELETE,
987 		.doit = l2tp_nl_cmd_session_delete,
988 		.policy = l2tp_nl_policy,
989 		.flags = GENL_ADMIN_PERM,
990 	},
991 	{
992 		.cmd = L2TP_CMD_SESSION_MODIFY,
993 		.doit = l2tp_nl_cmd_session_modify,
994 		.policy = l2tp_nl_policy,
995 		.flags = GENL_ADMIN_PERM,
996 	},
997 	{
998 		.cmd = L2TP_CMD_SESSION_GET,
999 		.doit = l2tp_nl_cmd_session_get,
1000 		.dumpit = l2tp_nl_cmd_session_dump,
1001 		.policy = l2tp_nl_policy,
1002 		.flags = GENL_ADMIN_PERM,
1003 	},
1004 };
1005 
1006 static struct genl_family l2tp_nl_family __ro_after_init = {
1007 	.name		= L2TP_GENL_NAME,
1008 	.version	= L2TP_GENL_VERSION,
1009 	.hdrsize	= 0,
1010 	.maxattr	= L2TP_ATTR_MAX,
1011 	.netnsok	= true,
1012 	.module		= THIS_MODULE,
1013 	.ops		= l2tp_nl_ops,
1014 	.n_ops		= ARRAY_SIZE(l2tp_nl_ops),
1015 	.mcgrps		= l2tp_multicast_group,
1016 	.n_mcgrps	= ARRAY_SIZE(l2tp_multicast_group),
1017 };
1018 
1019 int l2tp_nl_register_ops(enum l2tp_pwtype pw_type, const struct l2tp_nl_cmd_ops *ops)
1020 {
1021 	int ret;
1022 
1023 	ret = -EINVAL;
1024 	if (pw_type >= __L2TP_PWTYPE_MAX)
1025 		goto err;
1026 
1027 	genl_lock();
1028 	ret = -EBUSY;
1029 	if (l2tp_nl_cmd_ops[pw_type])
1030 		goto out;
1031 
1032 	l2tp_nl_cmd_ops[pw_type] = ops;
1033 	ret = 0;
1034 
1035 out:
1036 	genl_unlock();
1037 err:
1038 	return ret;
1039 }
1040 EXPORT_SYMBOL_GPL(l2tp_nl_register_ops);
1041 
1042 void l2tp_nl_unregister_ops(enum l2tp_pwtype pw_type)
1043 {
1044 	if (pw_type < __L2TP_PWTYPE_MAX) {
1045 		genl_lock();
1046 		l2tp_nl_cmd_ops[pw_type] = NULL;
1047 		genl_unlock();
1048 	}
1049 }
1050 EXPORT_SYMBOL_GPL(l2tp_nl_unregister_ops);
1051 
1052 static int __init l2tp_nl_init(void)
1053 {
1054 	pr_info("L2TP netlink interface\n");
1055 	return genl_register_family(&l2tp_nl_family);
1056 }
1057 
1058 static void l2tp_nl_cleanup(void)
1059 {
1060 	genl_unregister_family(&l2tp_nl_family);
1061 }
1062 
1063 module_init(l2tp_nl_init);
1064 module_exit(l2tp_nl_cleanup);
1065 
1066 MODULE_AUTHOR("James Chapman <jchapman@katalix.com>");
1067 MODULE_DESCRIPTION("L2TP netlink");
1068 MODULE_LICENSE("GPL");
1069 MODULE_VERSION("1.0");
1070 MODULE_ALIAS_GENL_FAMILY("l2tp");
1071