xref: /openbmc/linux/net/l2tp/l2tp_netlink.c (revision e6dec923) 
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_find(net, tunnel_id);
69 		if (tunnel)
70 			session = l2tp_session_get(net, tunnel, session_id,
71 						   do_ref);
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_find(net, tunnel_id);
275 	if (tunnel == NULL) {
276 		ret = -ENODEV;
277 		goto out;
278 	}
279 
280 	l2tp_tunnel_notify(&l2tp_nl_family, info,
281 			   tunnel, L2TP_CMD_TUNNEL_DELETE);
282 
283 	(void) l2tp_tunnel_delete(tunnel);
284 
285 out:
286 	return ret;
287 }
288 
289 static int l2tp_nl_cmd_tunnel_modify(struct sk_buff *skb, struct genl_info *info)
290 {
291 	struct l2tp_tunnel *tunnel;
292 	u32 tunnel_id;
293 	int ret = 0;
294 	struct net *net = genl_info_net(info);
295 
296 	if (!info->attrs[L2TP_ATTR_CONN_ID]) {
297 		ret = -EINVAL;
298 		goto out;
299 	}
300 	tunnel_id = nla_get_u32(info->attrs[L2TP_ATTR_CONN_ID]);
301 
302 	tunnel = l2tp_tunnel_find(net, tunnel_id);
303 	if (tunnel == NULL) {
304 		ret = -ENODEV;
305 		goto out;
306 	}
307 
308 	if (info->attrs[L2TP_ATTR_DEBUG])
309 		tunnel->debug = nla_get_u32(info->attrs[L2TP_ATTR_DEBUG]);
310 
311 	ret = l2tp_tunnel_notify(&l2tp_nl_family, info,
312 				 tunnel, L2TP_CMD_TUNNEL_MODIFY);
313 
314 out:
315 	return ret;
316 }
317 
318 static int l2tp_nl_tunnel_send(struct sk_buff *skb, u32 portid, u32 seq, int flags,
319 			       struct l2tp_tunnel *tunnel, u8 cmd)
320 {
321 	void *hdr;
322 	struct nlattr *nest;
323 	struct sock *sk = NULL;
324 	struct inet_sock *inet;
325 #if IS_ENABLED(CONFIG_IPV6)
326 	struct ipv6_pinfo *np = NULL;
327 #endif
328 
329 	hdr = genlmsg_put(skb, portid, seq, &l2tp_nl_family, flags, cmd);
330 	if (!hdr)
331 		return -EMSGSIZE;
332 
333 	if (nla_put_u8(skb, L2TP_ATTR_PROTO_VERSION, tunnel->version) ||
334 	    nla_put_u32(skb, L2TP_ATTR_CONN_ID, tunnel->tunnel_id) ||
335 	    nla_put_u32(skb, L2TP_ATTR_PEER_CONN_ID, tunnel->peer_tunnel_id) ||
336 	    nla_put_u32(skb, L2TP_ATTR_DEBUG, tunnel->debug) ||
337 	    nla_put_u16(skb, L2TP_ATTR_ENCAP_TYPE, tunnel->encap))
338 		goto nla_put_failure;
339 
340 	nest = nla_nest_start(skb, L2TP_ATTR_STATS);
341 	if (nest == NULL)
342 		goto nla_put_failure;
343 
344 	if (nla_put_u64_64bit(skb, L2TP_ATTR_TX_PACKETS,
345 			      atomic_long_read(&tunnel->stats.tx_packets),
346 			      L2TP_ATTR_STATS_PAD) ||
347 	    nla_put_u64_64bit(skb, L2TP_ATTR_TX_BYTES,
348 			      atomic_long_read(&tunnel->stats.tx_bytes),
349 			      L2TP_ATTR_STATS_PAD) ||
350 	    nla_put_u64_64bit(skb, L2TP_ATTR_TX_ERRORS,
351 			      atomic_long_read(&tunnel->stats.tx_errors),
352 			      L2TP_ATTR_STATS_PAD) ||
353 	    nla_put_u64_64bit(skb, L2TP_ATTR_RX_PACKETS,
354 			      atomic_long_read(&tunnel->stats.rx_packets),
355 			      L2TP_ATTR_STATS_PAD) ||
356 	    nla_put_u64_64bit(skb, L2TP_ATTR_RX_BYTES,
357 			      atomic_long_read(&tunnel->stats.rx_bytes),
358 			      L2TP_ATTR_STATS_PAD) ||
359 	    nla_put_u64_64bit(skb, L2TP_ATTR_RX_SEQ_DISCARDS,
360 			      atomic_long_read(&tunnel->stats.rx_seq_discards),
361 			      L2TP_ATTR_STATS_PAD) ||
362 	    nla_put_u64_64bit(skb, L2TP_ATTR_RX_OOS_PACKETS,
363 			      atomic_long_read(&tunnel->stats.rx_oos_packets),
364 			      L2TP_ATTR_STATS_PAD) ||
365 	    nla_put_u64_64bit(skb, L2TP_ATTR_RX_ERRORS,
366 			      atomic_long_read(&tunnel->stats.rx_errors),
367 			      L2TP_ATTR_STATS_PAD))
368 		goto nla_put_failure;
369 	nla_nest_end(skb, nest);
370 
371 	sk = tunnel->sock;
372 	if (!sk)
373 		goto out;
374 
375 #if IS_ENABLED(CONFIG_IPV6)
376 	if (sk->sk_family == AF_INET6)
377 		np = inet6_sk(sk);
378 #endif
379 
380 	inet = inet_sk(sk);
381 
382 	switch (tunnel->encap) {
383 	case L2TP_ENCAPTYPE_UDP:
384 		switch (sk->sk_family) {
385 		case AF_INET:
386 			if (nla_put_u8(skb, L2TP_ATTR_UDP_CSUM, !sk->sk_no_check_tx))
387 				goto nla_put_failure;
388 			break;
389 #if IS_ENABLED(CONFIG_IPV6)
390 		case AF_INET6:
391 			if (udp_get_no_check6_tx(sk) &&
392 			    nla_put_flag(skb, L2TP_ATTR_UDP_ZERO_CSUM6_TX))
393 				goto nla_put_failure;
394 			if (udp_get_no_check6_rx(sk) &&
395 			    nla_put_flag(skb, L2TP_ATTR_UDP_ZERO_CSUM6_RX))
396 				goto nla_put_failure;
397 			break;
398 #endif
399 		}
400 		if (nla_put_u16(skb, L2TP_ATTR_UDP_SPORT, ntohs(inet->inet_sport)) ||
401 		    nla_put_u16(skb, L2TP_ATTR_UDP_DPORT, ntohs(inet->inet_dport)))
402 			goto nla_put_failure;
403 		/* NOBREAK */
404 	case L2TP_ENCAPTYPE_IP:
405 #if IS_ENABLED(CONFIG_IPV6)
406 		if (np) {
407 			if (nla_put_in6_addr(skb, L2TP_ATTR_IP6_SADDR,
408 					     &np->saddr) ||
409 			    nla_put_in6_addr(skb, L2TP_ATTR_IP6_DADDR,
410 					     &sk->sk_v6_daddr))
411 				goto nla_put_failure;
412 		} else
413 #endif
414 		if (nla_put_in_addr(skb, L2TP_ATTR_IP_SADDR,
415 				    inet->inet_saddr) ||
416 		    nla_put_in_addr(skb, L2TP_ATTR_IP_DADDR,
417 				    inet->inet_daddr))
418 			goto nla_put_failure;
419 		break;
420 	}
421 
422 out:
423 	genlmsg_end(skb, hdr);
424 	return 0;
425 
426 nla_put_failure:
427 	genlmsg_cancel(skb, hdr);
428 	return -1;
429 }
430 
431 static int l2tp_nl_cmd_tunnel_get(struct sk_buff *skb, struct genl_info *info)
432 {
433 	struct l2tp_tunnel *tunnel;
434 	struct sk_buff *msg;
435 	u32 tunnel_id;
436 	int ret = -ENOBUFS;
437 	struct net *net = genl_info_net(info);
438 
439 	if (!info->attrs[L2TP_ATTR_CONN_ID]) {
440 		ret = -EINVAL;
441 		goto out;
442 	}
443 
444 	tunnel_id = nla_get_u32(info->attrs[L2TP_ATTR_CONN_ID]);
445 
446 	tunnel = l2tp_tunnel_find(net, tunnel_id);
447 	if (tunnel == NULL) {
448 		ret = -ENODEV;
449 		goto out;
450 	}
451 
452 	msg = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);
453 	if (!msg) {
454 		ret = -ENOMEM;
455 		goto out;
456 	}
457 
458 	ret = l2tp_nl_tunnel_send(msg, info->snd_portid, info->snd_seq,
459 				  NLM_F_ACK, tunnel, L2TP_CMD_TUNNEL_GET);
460 	if (ret < 0)
461 		goto err_out;
462 
463 	return genlmsg_unicast(net, msg, info->snd_portid);
464 
465 err_out:
466 	nlmsg_free(msg);
467 
468 out:
469 	return ret;
470 }
471 
472 static int l2tp_nl_cmd_tunnel_dump(struct sk_buff *skb, struct netlink_callback *cb)
473 {
474 	int ti = cb->args[0];
475 	struct l2tp_tunnel *tunnel;
476 	struct net *net = sock_net(skb->sk);
477 
478 	for (;;) {
479 		tunnel = l2tp_tunnel_find_nth(net, ti);
480 		if (tunnel == NULL)
481 			goto out;
482 
483 		if (l2tp_nl_tunnel_send(skb, NETLINK_CB(cb->skb).portid,
484 					cb->nlh->nlmsg_seq, NLM_F_MULTI,
485 					tunnel, L2TP_CMD_TUNNEL_GET) < 0)
486 			goto out;
487 
488 		ti++;
489 	}
490 
491 out:
492 	cb->args[0] = ti;
493 
494 	return skb->len;
495 }
496 
497 static int l2tp_nl_cmd_session_create(struct sk_buff *skb, struct genl_info *info)
498 {
499 	u32 tunnel_id = 0;
500 	u32 session_id;
501 	u32 peer_session_id;
502 	int ret = 0;
503 	struct l2tp_tunnel *tunnel;
504 	struct l2tp_session *session;
505 	struct l2tp_session_cfg cfg = { 0, };
506 	struct net *net = genl_info_net(info);
507 
508 	if (!info->attrs[L2TP_ATTR_CONN_ID]) {
509 		ret = -EINVAL;
510 		goto out;
511 	}
512 	tunnel_id = nla_get_u32(info->attrs[L2TP_ATTR_CONN_ID]);
513 	tunnel = l2tp_tunnel_find(net, tunnel_id);
514 	if (!tunnel) {
515 		ret = -ENODEV;
516 		goto out;
517 	}
518 
519 	if (!info->attrs[L2TP_ATTR_SESSION_ID]) {
520 		ret = -EINVAL;
521 		goto out;
522 	}
523 	session_id = nla_get_u32(info->attrs[L2TP_ATTR_SESSION_ID]);
524 
525 	if (!info->attrs[L2TP_ATTR_PEER_SESSION_ID]) {
526 		ret = -EINVAL;
527 		goto out;
528 	}
529 	peer_session_id = nla_get_u32(info->attrs[L2TP_ATTR_PEER_SESSION_ID]);
530 
531 	if (!info->attrs[L2TP_ATTR_PW_TYPE]) {
532 		ret = -EINVAL;
533 		goto out;
534 	}
535 	cfg.pw_type = nla_get_u16(info->attrs[L2TP_ATTR_PW_TYPE]);
536 	if (cfg.pw_type >= __L2TP_PWTYPE_MAX) {
537 		ret = -EINVAL;
538 		goto out;
539 	}
540 
541 	if (tunnel->version > 2) {
542 		if (info->attrs[L2TP_ATTR_OFFSET])
543 			cfg.offset = nla_get_u16(info->attrs[L2TP_ATTR_OFFSET]);
544 
545 		if (info->attrs[L2TP_ATTR_DATA_SEQ])
546 			cfg.data_seq = nla_get_u8(info->attrs[L2TP_ATTR_DATA_SEQ]);
547 
548 		cfg.l2specific_type = L2TP_L2SPECTYPE_DEFAULT;
549 		if (info->attrs[L2TP_ATTR_L2SPEC_TYPE])
550 			cfg.l2specific_type = nla_get_u8(info->attrs[L2TP_ATTR_L2SPEC_TYPE]);
551 
552 		cfg.l2specific_len = 4;
553 		if (info->attrs[L2TP_ATTR_L2SPEC_LEN])
554 			cfg.l2specific_len = nla_get_u8(info->attrs[L2TP_ATTR_L2SPEC_LEN]);
555 
556 		if (info->attrs[L2TP_ATTR_COOKIE]) {
557 			u16 len = nla_len(info->attrs[L2TP_ATTR_COOKIE]);
558 			if (len > 8) {
559 				ret = -EINVAL;
560 				goto out;
561 			}
562 			cfg.cookie_len = len;
563 			memcpy(&cfg.cookie[0], nla_data(info->attrs[L2TP_ATTR_COOKIE]), len);
564 		}
565 		if (info->attrs[L2TP_ATTR_PEER_COOKIE]) {
566 			u16 len = nla_len(info->attrs[L2TP_ATTR_PEER_COOKIE]);
567 			if (len > 8) {
568 				ret = -EINVAL;
569 				goto out;
570 			}
571 			cfg.peer_cookie_len = len;
572 			memcpy(&cfg.peer_cookie[0], nla_data(info->attrs[L2TP_ATTR_PEER_COOKIE]), len);
573 		}
574 		if (info->attrs[L2TP_ATTR_IFNAME])
575 			cfg.ifname = nla_data(info->attrs[L2TP_ATTR_IFNAME]);
576 
577 		if (info->attrs[L2TP_ATTR_VLAN_ID])
578 			cfg.vlan_id = nla_get_u16(info->attrs[L2TP_ATTR_VLAN_ID]);
579 	}
580 
581 	if (info->attrs[L2TP_ATTR_DEBUG])
582 		cfg.debug = nla_get_u32(info->attrs[L2TP_ATTR_DEBUG]);
583 
584 	if (info->attrs[L2TP_ATTR_RECV_SEQ])
585 		cfg.recv_seq = nla_get_u8(info->attrs[L2TP_ATTR_RECV_SEQ]);
586 
587 	if (info->attrs[L2TP_ATTR_SEND_SEQ])
588 		cfg.send_seq = nla_get_u8(info->attrs[L2TP_ATTR_SEND_SEQ]);
589 
590 	if (info->attrs[L2TP_ATTR_LNS_MODE])
591 		cfg.lns_mode = nla_get_u8(info->attrs[L2TP_ATTR_LNS_MODE]);
592 
593 	if (info->attrs[L2TP_ATTR_RECV_TIMEOUT])
594 		cfg.reorder_timeout = nla_get_msecs(info->attrs[L2TP_ATTR_RECV_TIMEOUT]);
595 
596 	if (info->attrs[L2TP_ATTR_MTU])
597 		cfg.mtu = nla_get_u16(info->attrs[L2TP_ATTR_MTU]);
598 
599 	if (info->attrs[L2TP_ATTR_MRU])
600 		cfg.mru = nla_get_u16(info->attrs[L2TP_ATTR_MRU]);
601 
602 #ifdef CONFIG_MODULES
603 	if (l2tp_nl_cmd_ops[cfg.pw_type] == NULL) {
604 		genl_unlock();
605 		request_module("net-l2tp-type-%u", cfg.pw_type);
606 		genl_lock();
607 	}
608 #endif
609 	if ((l2tp_nl_cmd_ops[cfg.pw_type] == NULL) ||
610 	    (l2tp_nl_cmd_ops[cfg.pw_type]->session_create == NULL)) {
611 		ret = -EPROTONOSUPPORT;
612 		goto out;
613 	}
614 
615 	/* Check that pseudowire-specific params are present */
616 	switch (cfg.pw_type) {
617 	case L2TP_PWTYPE_NONE:
618 		break;
619 	case L2TP_PWTYPE_ETH_VLAN:
620 		if (!info->attrs[L2TP_ATTR_VLAN_ID]) {
621 			ret = -EINVAL;
622 			goto out;
623 		}
624 		break;
625 	case L2TP_PWTYPE_ETH:
626 		break;
627 	case L2TP_PWTYPE_PPP:
628 	case L2TP_PWTYPE_PPP_AC:
629 		break;
630 	case L2TP_PWTYPE_IP:
631 	default:
632 		ret = -EPROTONOSUPPORT;
633 		break;
634 	}
635 
636 	ret = -EPROTONOSUPPORT;
637 	if (l2tp_nl_cmd_ops[cfg.pw_type]->session_create)
638 		ret = (*l2tp_nl_cmd_ops[cfg.pw_type]->session_create)(net, tunnel_id,
639 			session_id, peer_session_id, &cfg);
640 
641 	if (ret >= 0) {
642 		session = l2tp_session_get(net, tunnel, session_id, false);
643 		if (session) {
644 			ret = l2tp_session_notify(&l2tp_nl_family, info, session,
645 						  L2TP_CMD_SESSION_CREATE);
646 			l2tp_session_dec_refcount(session);
647 		}
648 	}
649 
650 out:
651 	return ret;
652 }
653 
654 static int l2tp_nl_cmd_session_delete(struct sk_buff *skb, struct genl_info *info)
655 {
656 	int ret = 0;
657 	struct l2tp_session *session;
658 	u16 pw_type;
659 
660 	session = l2tp_nl_session_get(info, true);
661 	if (session == NULL) {
662 		ret = -ENODEV;
663 		goto out;
664 	}
665 
666 	l2tp_session_notify(&l2tp_nl_family, info,
667 			    session, L2TP_CMD_SESSION_DELETE);
668 
669 	pw_type = session->pwtype;
670 	if (pw_type < __L2TP_PWTYPE_MAX)
671 		if (l2tp_nl_cmd_ops[pw_type] && l2tp_nl_cmd_ops[pw_type]->session_delete)
672 			ret = (*l2tp_nl_cmd_ops[pw_type]->session_delete)(session);
673 
674 	if (session->deref)
675 		session->deref(session);
676 	l2tp_session_dec_refcount(session);
677 
678 out:
679 	return ret;
680 }
681 
682 static int l2tp_nl_cmd_session_modify(struct sk_buff *skb, struct genl_info *info)
683 {
684 	int ret = 0;
685 	struct l2tp_session *session;
686 
687 	session = l2tp_nl_session_get(info, false);
688 	if (session == NULL) {
689 		ret = -ENODEV;
690 		goto out;
691 	}
692 
693 	if (info->attrs[L2TP_ATTR_DEBUG])
694 		session->debug = nla_get_u32(info->attrs[L2TP_ATTR_DEBUG]);
695 
696 	if (info->attrs[L2TP_ATTR_DATA_SEQ])
697 		session->data_seq = nla_get_u8(info->attrs[L2TP_ATTR_DATA_SEQ]);
698 
699 	if (info->attrs[L2TP_ATTR_RECV_SEQ])
700 		session->recv_seq = nla_get_u8(info->attrs[L2TP_ATTR_RECV_SEQ]);
701 
702 	if (info->attrs[L2TP_ATTR_SEND_SEQ]) {
703 		session->send_seq = nla_get_u8(info->attrs[L2TP_ATTR_SEND_SEQ]);
704 		l2tp_session_set_header_len(session, session->tunnel->version);
705 	}
706 
707 	if (info->attrs[L2TP_ATTR_LNS_MODE])
708 		session->lns_mode = nla_get_u8(info->attrs[L2TP_ATTR_LNS_MODE]);
709 
710 	if (info->attrs[L2TP_ATTR_RECV_TIMEOUT])
711 		session->reorder_timeout = nla_get_msecs(info->attrs[L2TP_ATTR_RECV_TIMEOUT]);
712 
713 	if (info->attrs[L2TP_ATTR_MTU])
714 		session->mtu = nla_get_u16(info->attrs[L2TP_ATTR_MTU]);
715 
716 	if (info->attrs[L2TP_ATTR_MRU])
717 		session->mru = nla_get_u16(info->attrs[L2TP_ATTR_MRU]);
718 
719 	ret = l2tp_session_notify(&l2tp_nl_family, info,
720 				  session, L2TP_CMD_SESSION_MODIFY);
721 
722 	l2tp_session_dec_refcount(session);
723 
724 out:
725 	return ret;
726 }
727 
728 static int l2tp_nl_session_send(struct sk_buff *skb, u32 portid, u32 seq, int flags,
729 				struct l2tp_session *session, u8 cmd)
730 {
731 	void *hdr;
732 	struct nlattr *nest;
733 	struct l2tp_tunnel *tunnel = session->tunnel;
734 	struct sock *sk = NULL;
735 
736 	sk = tunnel->sock;
737 
738 	hdr = genlmsg_put(skb, portid, seq, &l2tp_nl_family, flags, cmd);
739 	if (!hdr)
740 		return -EMSGSIZE;
741 
742 	if (nla_put_u32(skb, L2TP_ATTR_CONN_ID, tunnel->tunnel_id) ||
743 	    nla_put_u32(skb, L2TP_ATTR_SESSION_ID, session->session_id) ||
744 	    nla_put_u32(skb, L2TP_ATTR_PEER_CONN_ID, tunnel->peer_tunnel_id) ||
745 	    nla_put_u32(skb, L2TP_ATTR_PEER_SESSION_ID,
746 			session->peer_session_id) ||
747 	    nla_put_u32(skb, L2TP_ATTR_DEBUG, session->debug) ||
748 	    nla_put_u16(skb, L2TP_ATTR_PW_TYPE, session->pwtype) ||
749 	    nla_put_u16(skb, L2TP_ATTR_MTU, session->mtu) ||
750 	    (session->mru &&
751 	     nla_put_u16(skb, L2TP_ATTR_MRU, session->mru)))
752 		goto nla_put_failure;
753 
754 	if ((session->ifname[0] &&
755 	     nla_put_string(skb, L2TP_ATTR_IFNAME, session->ifname)) ||
756 	    (session->cookie_len &&
757 	     nla_put(skb, L2TP_ATTR_COOKIE, session->cookie_len,
758 		     &session->cookie[0])) ||
759 	    (session->peer_cookie_len &&
760 	     nla_put(skb, L2TP_ATTR_PEER_COOKIE, session->peer_cookie_len,
761 		     &session->peer_cookie[0])) ||
762 	    nla_put_u8(skb, L2TP_ATTR_RECV_SEQ, session->recv_seq) ||
763 	    nla_put_u8(skb, L2TP_ATTR_SEND_SEQ, session->send_seq) ||
764 	    nla_put_u8(skb, L2TP_ATTR_LNS_MODE, session->lns_mode) ||
765 #ifdef CONFIG_XFRM
766 	    (((sk) && (sk->sk_policy[0] || sk->sk_policy[1])) &&
767 	     nla_put_u8(skb, L2TP_ATTR_USING_IPSEC, 1)) ||
768 #endif
769 	    (session->reorder_timeout &&
770 	     nla_put_msecs(skb, L2TP_ATTR_RECV_TIMEOUT,
771 			   session->reorder_timeout, L2TP_ATTR_PAD)))
772 		goto nla_put_failure;
773 
774 	nest = nla_nest_start(skb, L2TP_ATTR_STATS);
775 	if (nest == NULL)
776 		goto nla_put_failure;
777 
778 	if (nla_put_u64_64bit(skb, L2TP_ATTR_TX_PACKETS,
779 			      atomic_long_read(&session->stats.tx_packets),
780 			      L2TP_ATTR_STATS_PAD) ||
781 	    nla_put_u64_64bit(skb, L2TP_ATTR_TX_BYTES,
782 			      atomic_long_read(&session->stats.tx_bytes),
783 			      L2TP_ATTR_STATS_PAD) ||
784 	    nla_put_u64_64bit(skb, L2TP_ATTR_TX_ERRORS,
785 			      atomic_long_read(&session->stats.tx_errors),
786 			      L2TP_ATTR_STATS_PAD) ||
787 	    nla_put_u64_64bit(skb, L2TP_ATTR_RX_PACKETS,
788 			      atomic_long_read(&session->stats.rx_packets),
789 			      L2TP_ATTR_STATS_PAD) ||
790 	    nla_put_u64_64bit(skb, L2TP_ATTR_RX_BYTES,
791 			      atomic_long_read(&session->stats.rx_bytes),
792 			      L2TP_ATTR_STATS_PAD) ||
793 	    nla_put_u64_64bit(skb, L2TP_ATTR_RX_SEQ_DISCARDS,
794 			      atomic_long_read(&session->stats.rx_seq_discards),
795 			      L2TP_ATTR_STATS_PAD) ||
796 	    nla_put_u64_64bit(skb, L2TP_ATTR_RX_OOS_PACKETS,
797 			      atomic_long_read(&session->stats.rx_oos_packets),
798 			      L2TP_ATTR_STATS_PAD) ||
799 	    nla_put_u64_64bit(skb, L2TP_ATTR_RX_ERRORS,
800 			      atomic_long_read(&session->stats.rx_errors),
801 			      L2TP_ATTR_STATS_PAD))
802 		goto nla_put_failure;
803 	nla_nest_end(skb, nest);
804 
805 	genlmsg_end(skb, hdr);
806 	return 0;
807 
808  nla_put_failure:
809 	genlmsg_cancel(skb, hdr);
810 	return -1;
811 }
812 
813 static int l2tp_nl_cmd_session_get(struct sk_buff *skb, struct genl_info *info)
814 {
815 	struct l2tp_session *session;
816 	struct sk_buff *msg;
817 	int ret;
818 
819 	session = l2tp_nl_session_get(info, false);
820 	if (session == NULL) {
821 		ret = -ENODEV;
822 		goto err;
823 	}
824 
825 	msg = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);
826 	if (!msg) {
827 		ret = -ENOMEM;
828 		goto err_ref;
829 	}
830 
831 	ret = l2tp_nl_session_send(msg, info->snd_portid, info->snd_seq,
832 				   0, session, L2TP_CMD_SESSION_GET);
833 	if (ret < 0)
834 		goto err_ref_msg;
835 
836 	ret = genlmsg_unicast(genl_info_net(info), msg, info->snd_portid);
837 
838 	l2tp_session_dec_refcount(session);
839 
840 	return ret;
841 
842 err_ref_msg:
843 	nlmsg_free(msg);
844 err_ref:
845 	l2tp_session_dec_refcount(session);
846 err:
847 	return ret;
848 }
849 
850 static int l2tp_nl_cmd_session_dump(struct sk_buff *skb, struct netlink_callback *cb)
851 {
852 	struct net *net = sock_net(skb->sk);
853 	struct l2tp_session *session;
854 	struct l2tp_tunnel *tunnel = NULL;
855 	int ti = cb->args[0];
856 	int si = cb->args[1];
857 
858 	for (;;) {
859 		if (tunnel == NULL) {
860 			tunnel = l2tp_tunnel_find_nth(net, ti);
861 			if (tunnel == NULL)
862 				goto out;
863 		}
864 
865 		session = l2tp_session_get_nth(tunnel, si, false);
866 		if (session == NULL) {
867 			ti++;
868 			tunnel = NULL;
869 			si = 0;
870 			continue;
871 		}
872 
873 		if (l2tp_nl_session_send(skb, NETLINK_CB(cb->skb).portid,
874 					 cb->nlh->nlmsg_seq, NLM_F_MULTI,
875 					 session, L2TP_CMD_SESSION_GET) < 0) {
876 			l2tp_session_dec_refcount(session);
877 			break;
878 		}
879 		l2tp_session_dec_refcount(session);
880 
881 		si++;
882 	}
883 
884 out:
885 	cb->args[0] = ti;
886 	cb->args[1] = si;
887 
888 	return skb->len;
889 }
890 
891 static const struct nla_policy l2tp_nl_policy[L2TP_ATTR_MAX + 1] = {
892 	[L2TP_ATTR_NONE]		= { .type = NLA_UNSPEC, },
893 	[L2TP_ATTR_PW_TYPE]		= { .type = NLA_U16, },
894 	[L2TP_ATTR_ENCAP_TYPE]		= { .type = NLA_U16, },
895 	[L2TP_ATTR_OFFSET]		= { .type = NLA_U16, },
896 	[L2TP_ATTR_DATA_SEQ]		= { .type = NLA_U8, },
897 	[L2TP_ATTR_L2SPEC_TYPE]		= { .type = NLA_U8, },
898 	[L2TP_ATTR_L2SPEC_LEN]		= { .type = NLA_U8, },
899 	[L2TP_ATTR_PROTO_VERSION]	= { .type = NLA_U8, },
900 	[L2TP_ATTR_CONN_ID]		= { .type = NLA_U32, },
901 	[L2TP_ATTR_PEER_CONN_ID]	= { .type = NLA_U32, },
902 	[L2TP_ATTR_SESSION_ID]		= { .type = NLA_U32, },
903 	[L2TP_ATTR_PEER_SESSION_ID]	= { .type = NLA_U32, },
904 	[L2TP_ATTR_UDP_CSUM]		= { .type = NLA_U8, },
905 	[L2TP_ATTR_VLAN_ID]		= { .type = NLA_U16, },
906 	[L2TP_ATTR_DEBUG]		= { .type = NLA_U32, },
907 	[L2TP_ATTR_RECV_SEQ]		= { .type = NLA_U8, },
908 	[L2TP_ATTR_SEND_SEQ]		= { .type = NLA_U8, },
909 	[L2TP_ATTR_LNS_MODE]		= { .type = NLA_U8, },
910 	[L2TP_ATTR_USING_IPSEC]		= { .type = NLA_U8, },
911 	[L2TP_ATTR_RECV_TIMEOUT]	= { .type = NLA_MSECS, },
912 	[L2TP_ATTR_FD]			= { .type = NLA_U32, },
913 	[L2TP_ATTR_IP_SADDR]		= { .type = NLA_U32, },
914 	[L2TP_ATTR_IP_DADDR]		= { .type = NLA_U32, },
915 	[L2TP_ATTR_UDP_SPORT]		= { .type = NLA_U16, },
916 	[L2TP_ATTR_UDP_DPORT]		= { .type = NLA_U16, },
917 	[L2TP_ATTR_MTU]			= { .type = NLA_U16, },
918 	[L2TP_ATTR_MRU]			= { .type = NLA_U16, },
919 	[L2TP_ATTR_STATS]		= { .type = NLA_NESTED, },
920 	[L2TP_ATTR_IP6_SADDR] = {
921 		.type = NLA_BINARY,
922 		.len = sizeof(struct in6_addr),
923 	},
924 	[L2TP_ATTR_IP6_DADDR] = {
925 		.type = NLA_BINARY,
926 		.len = sizeof(struct in6_addr),
927 	},
928 	[L2TP_ATTR_IFNAME] = {
929 		.type = NLA_NUL_STRING,
930 		.len = IFNAMSIZ - 1,
931 	},
932 	[L2TP_ATTR_COOKIE] = {
933 		.type = NLA_BINARY,
934 		.len = 8,
935 	},
936 	[L2TP_ATTR_PEER_COOKIE] = {
937 		.type = NLA_BINARY,
938 		.len = 8,
939 	},
940 };
941 
942 static const struct genl_ops l2tp_nl_ops[] = {
943 	{
944 		.cmd = L2TP_CMD_NOOP,
945 		.doit = l2tp_nl_cmd_noop,
946 		.policy = l2tp_nl_policy,
947 		/* can be retrieved by unprivileged users */
948 	},
949 	{
950 		.cmd = L2TP_CMD_TUNNEL_CREATE,
951 		.doit = l2tp_nl_cmd_tunnel_create,
952 		.policy = l2tp_nl_policy,
953 		.flags = GENL_ADMIN_PERM,
954 	},
955 	{
956 		.cmd = L2TP_CMD_TUNNEL_DELETE,
957 		.doit = l2tp_nl_cmd_tunnel_delete,
958 		.policy = l2tp_nl_policy,
959 		.flags = GENL_ADMIN_PERM,
960 	},
961 	{
962 		.cmd = L2TP_CMD_TUNNEL_MODIFY,
963 		.doit = l2tp_nl_cmd_tunnel_modify,
964 		.policy = l2tp_nl_policy,
965 		.flags = GENL_ADMIN_PERM,
966 	},
967 	{
968 		.cmd = L2TP_CMD_TUNNEL_GET,
969 		.doit = l2tp_nl_cmd_tunnel_get,
970 		.dumpit = l2tp_nl_cmd_tunnel_dump,
971 		.policy = l2tp_nl_policy,
972 		.flags = GENL_ADMIN_PERM,
973 	},
974 	{
975 		.cmd = L2TP_CMD_SESSION_CREATE,
976 		.doit = l2tp_nl_cmd_session_create,
977 		.policy = l2tp_nl_policy,
978 		.flags = GENL_ADMIN_PERM,
979 	},
980 	{
981 		.cmd = L2TP_CMD_SESSION_DELETE,
982 		.doit = l2tp_nl_cmd_session_delete,
983 		.policy = l2tp_nl_policy,
984 		.flags = GENL_ADMIN_PERM,
985 	},
986 	{
987 		.cmd = L2TP_CMD_SESSION_MODIFY,
988 		.doit = l2tp_nl_cmd_session_modify,
989 		.policy = l2tp_nl_policy,
990 		.flags = GENL_ADMIN_PERM,
991 	},
992 	{
993 		.cmd = L2TP_CMD_SESSION_GET,
994 		.doit = l2tp_nl_cmd_session_get,
995 		.dumpit = l2tp_nl_cmd_session_dump,
996 		.policy = l2tp_nl_policy,
997 		.flags = GENL_ADMIN_PERM,
998 	},
999 };
1000 
1001 static struct genl_family l2tp_nl_family __ro_after_init = {
1002 	.name		= L2TP_GENL_NAME,
1003 	.version	= L2TP_GENL_VERSION,
1004 	.hdrsize	= 0,
1005 	.maxattr	= L2TP_ATTR_MAX,
1006 	.netnsok	= true,
1007 	.module		= THIS_MODULE,
1008 	.ops		= l2tp_nl_ops,
1009 	.n_ops		= ARRAY_SIZE(l2tp_nl_ops),
1010 	.mcgrps		= l2tp_multicast_group,
1011 	.n_mcgrps	= ARRAY_SIZE(l2tp_multicast_group),
1012 };
1013 
1014 int l2tp_nl_register_ops(enum l2tp_pwtype pw_type, const struct l2tp_nl_cmd_ops *ops)
1015 {
1016 	int ret;
1017 
1018 	ret = -EINVAL;
1019 	if (pw_type >= __L2TP_PWTYPE_MAX)
1020 		goto err;
1021 
1022 	genl_lock();
1023 	ret = -EBUSY;
1024 	if (l2tp_nl_cmd_ops[pw_type])
1025 		goto out;
1026 
1027 	l2tp_nl_cmd_ops[pw_type] = ops;
1028 	ret = 0;
1029 
1030 out:
1031 	genl_unlock();
1032 err:
1033 	return ret;
1034 }
1035 EXPORT_SYMBOL_GPL(l2tp_nl_register_ops);
1036 
1037 void l2tp_nl_unregister_ops(enum l2tp_pwtype pw_type)
1038 {
1039 	if (pw_type < __L2TP_PWTYPE_MAX) {
1040 		genl_lock();
1041 		l2tp_nl_cmd_ops[pw_type] = NULL;
1042 		genl_unlock();
1043 	}
1044 }
1045 EXPORT_SYMBOL_GPL(l2tp_nl_unregister_ops);
1046 
1047 static int __init l2tp_nl_init(void)
1048 {
1049 	pr_info("L2TP netlink interface\n");
1050 	return genl_register_family(&l2tp_nl_family);
1051 }
1052 
1053 static void l2tp_nl_cleanup(void)
1054 {
1055 	genl_unregister_family(&l2tp_nl_family);
1056 }
1057 
1058 module_init(l2tp_nl_init);
1059 module_exit(l2tp_nl_cleanup);
1060 
1061 MODULE_AUTHOR("James Chapman <jchapman@katalix.com>");
1062 MODULE_DESCRIPTION("L2TP netlink");
1063 MODULE_LICENSE("GPL");
1064 MODULE_VERSION("1.0");
1065 MODULE_ALIAS_GENL_FAMILY("l2tp");
1066