xref: /openbmc/linux/net/l2tp/l2tp_netlink.c (revision 930beb5a)
1 /*
2  * L2TP netlink layer, for management
3  *
4  * Copyright (c) 2008,2009,2010 Katalix Systems Ltd
5  *
6  * Partly based on the IrDA nelink implementation
7  * (see net/irda/irnetlink.c) which is:
8  * Copyright (c) 2007 Samuel Ortiz <samuel@sortiz.org>
9  * which is in turn partly based on the wireless netlink code:
10  * Copyright 2006 Johannes Berg <johannes@sipsolutions.net>
11  *
12  * This program is free software; you can redistribute it and/or modify
13  * it under the terms of the GNU General Public License version 2 as
14  * published by the Free Software Foundation.
15  */
16 
17 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
18 
19 #include <net/sock.h>
20 #include <net/genetlink.h>
21 #include <net/udp.h>
22 #include <linux/in.h>
23 #include <linux/udp.h>
24 #include <linux/socket.h>
25 #include <linux/module.h>
26 #include <linux/list.h>
27 #include <net/net_namespace.h>
28 
29 #include <linux/l2tp.h>
30 
31 #include "l2tp_core.h"
32 
33 
34 static struct genl_family l2tp_nl_family = {
35 	.id		= GENL_ID_GENERATE,
36 	.name		= L2TP_GENL_NAME,
37 	.version	= L2TP_GENL_VERSION,
38 	.hdrsize	= 0,
39 	.maxattr	= L2TP_ATTR_MAX,
40 	.netnsok	= true,
41 };
42 
43 /* Accessed under genl lock */
44 static const struct l2tp_nl_cmd_ops *l2tp_nl_cmd_ops[__L2TP_PWTYPE_MAX];
45 
46 static struct l2tp_session *l2tp_nl_session_find(struct genl_info *info)
47 {
48 	u32 tunnel_id;
49 	u32 session_id;
50 	char *ifname;
51 	struct l2tp_tunnel *tunnel;
52 	struct l2tp_session *session = NULL;
53 	struct net *net = genl_info_net(info);
54 
55 	if (info->attrs[L2TP_ATTR_IFNAME]) {
56 		ifname = nla_data(info->attrs[L2TP_ATTR_IFNAME]);
57 		session = l2tp_session_find_by_ifname(net, ifname);
58 	} else if ((info->attrs[L2TP_ATTR_SESSION_ID]) &&
59 		   (info->attrs[L2TP_ATTR_CONN_ID])) {
60 		tunnel_id = nla_get_u32(info->attrs[L2TP_ATTR_CONN_ID]);
61 		session_id = nla_get_u32(info->attrs[L2TP_ATTR_SESSION_ID]);
62 		tunnel = l2tp_tunnel_find(net, tunnel_id);
63 		if (tunnel)
64 			session = l2tp_session_find(net, tunnel, session_id);
65 	}
66 
67 	return session;
68 }
69 
70 static int l2tp_nl_cmd_noop(struct sk_buff *skb, struct genl_info *info)
71 {
72 	struct sk_buff *msg;
73 	void *hdr;
74 	int ret = -ENOBUFS;
75 
76 	msg = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);
77 	if (!msg) {
78 		ret = -ENOMEM;
79 		goto out;
80 	}
81 
82 	hdr = genlmsg_put(msg, info->snd_portid, info->snd_seq,
83 			  &l2tp_nl_family, 0, L2TP_CMD_NOOP);
84 	if (!hdr) {
85 		ret = -EMSGSIZE;
86 		goto err_out;
87 	}
88 
89 	genlmsg_end(msg, hdr);
90 
91 	return genlmsg_unicast(genl_info_net(info), msg, info->snd_portid);
92 
93 err_out:
94 	nlmsg_free(msg);
95 
96 out:
97 	return ret;
98 }
99 
100 static int l2tp_nl_cmd_tunnel_create(struct sk_buff *skb, struct genl_info *info)
101 {
102 	u32 tunnel_id;
103 	u32 peer_tunnel_id;
104 	int proto_version;
105 	int fd;
106 	int ret = 0;
107 	struct l2tp_tunnel_cfg cfg = { 0, };
108 	struct l2tp_tunnel *tunnel;
109 	struct net *net = genl_info_net(info);
110 
111 	if (!info->attrs[L2TP_ATTR_CONN_ID]) {
112 		ret = -EINVAL;
113 		goto out;
114 	}
115 	tunnel_id = nla_get_u32(info->attrs[L2TP_ATTR_CONN_ID]);
116 
117 	if (!info->attrs[L2TP_ATTR_PEER_CONN_ID]) {
118 		ret = -EINVAL;
119 		goto out;
120 	}
121 	peer_tunnel_id = nla_get_u32(info->attrs[L2TP_ATTR_PEER_CONN_ID]);
122 
123 	if (!info->attrs[L2TP_ATTR_PROTO_VERSION]) {
124 		ret = -EINVAL;
125 		goto out;
126 	}
127 	proto_version = nla_get_u8(info->attrs[L2TP_ATTR_PROTO_VERSION]);
128 
129 	if (!info->attrs[L2TP_ATTR_ENCAP_TYPE]) {
130 		ret = -EINVAL;
131 		goto out;
132 	}
133 	cfg.encap = nla_get_u16(info->attrs[L2TP_ATTR_ENCAP_TYPE]);
134 
135 	fd = -1;
136 	if (info->attrs[L2TP_ATTR_FD]) {
137 		fd = nla_get_u32(info->attrs[L2TP_ATTR_FD]);
138 	} else {
139 #if IS_ENABLED(CONFIG_IPV6)
140 		if (info->attrs[L2TP_ATTR_IP6_SADDR] &&
141 		    info->attrs[L2TP_ATTR_IP6_DADDR]) {
142 			cfg.local_ip6 = nla_data(
143 				info->attrs[L2TP_ATTR_IP6_SADDR]);
144 			cfg.peer_ip6 = nla_data(
145 				info->attrs[L2TP_ATTR_IP6_DADDR]);
146 		} else
147 #endif
148 		if (info->attrs[L2TP_ATTR_IP_SADDR] &&
149 		    info->attrs[L2TP_ATTR_IP_DADDR]) {
150 			cfg.local_ip.s_addr = nla_get_be32(
151 				info->attrs[L2TP_ATTR_IP_SADDR]);
152 			cfg.peer_ip.s_addr = nla_get_be32(
153 				info->attrs[L2TP_ATTR_IP_DADDR]);
154 		} else {
155 			ret = -EINVAL;
156 			goto out;
157 		}
158 		if (info->attrs[L2TP_ATTR_UDP_SPORT])
159 			cfg.local_udp_port = nla_get_u16(info->attrs[L2TP_ATTR_UDP_SPORT]);
160 		if (info->attrs[L2TP_ATTR_UDP_DPORT])
161 			cfg.peer_udp_port = nla_get_u16(info->attrs[L2TP_ATTR_UDP_DPORT]);
162 		if (info->attrs[L2TP_ATTR_UDP_CSUM])
163 			cfg.use_udp_checksums = nla_get_flag(info->attrs[L2TP_ATTR_UDP_CSUM]);
164 	}
165 
166 	if (info->attrs[L2TP_ATTR_DEBUG])
167 		cfg.debug = nla_get_u32(info->attrs[L2TP_ATTR_DEBUG]);
168 
169 	tunnel = l2tp_tunnel_find(net, tunnel_id);
170 	if (tunnel != NULL) {
171 		ret = -EEXIST;
172 		goto out;
173 	}
174 
175 	ret = -EINVAL;
176 	switch (cfg.encap) {
177 	case L2TP_ENCAPTYPE_UDP:
178 	case L2TP_ENCAPTYPE_IP:
179 		ret = l2tp_tunnel_create(net, fd, proto_version, tunnel_id,
180 					 peer_tunnel_id, &cfg, &tunnel);
181 		break;
182 	}
183 
184 out:
185 	return ret;
186 }
187 
188 static int l2tp_nl_cmd_tunnel_delete(struct sk_buff *skb, struct genl_info *info)
189 {
190 	struct l2tp_tunnel *tunnel;
191 	u32 tunnel_id;
192 	int ret = 0;
193 	struct net *net = genl_info_net(info);
194 
195 	if (!info->attrs[L2TP_ATTR_CONN_ID]) {
196 		ret = -EINVAL;
197 		goto out;
198 	}
199 	tunnel_id = nla_get_u32(info->attrs[L2TP_ATTR_CONN_ID]);
200 
201 	tunnel = l2tp_tunnel_find(net, tunnel_id);
202 	if (tunnel == NULL) {
203 		ret = -ENODEV;
204 		goto out;
205 	}
206 
207 	(void) l2tp_tunnel_delete(tunnel);
208 
209 out:
210 	return ret;
211 }
212 
213 static int l2tp_nl_cmd_tunnel_modify(struct sk_buff *skb, struct genl_info *info)
214 {
215 	struct l2tp_tunnel *tunnel;
216 	u32 tunnel_id;
217 	int ret = 0;
218 	struct net *net = genl_info_net(info);
219 
220 	if (!info->attrs[L2TP_ATTR_CONN_ID]) {
221 		ret = -EINVAL;
222 		goto out;
223 	}
224 	tunnel_id = nla_get_u32(info->attrs[L2TP_ATTR_CONN_ID]);
225 
226 	tunnel = l2tp_tunnel_find(net, tunnel_id);
227 	if (tunnel == NULL) {
228 		ret = -ENODEV;
229 		goto out;
230 	}
231 
232 	if (info->attrs[L2TP_ATTR_DEBUG])
233 		tunnel->debug = nla_get_u32(info->attrs[L2TP_ATTR_DEBUG]);
234 
235 out:
236 	return ret;
237 }
238 
239 static int l2tp_nl_tunnel_send(struct sk_buff *skb, u32 portid, u32 seq, int flags,
240 			       struct l2tp_tunnel *tunnel)
241 {
242 	void *hdr;
243 	struct nlattr *nest;
244 	struct sock *sk = NULL;
245 	struct inet_sock *inet;
246 #if IS_ENABLED(CONFIG_IPV6)
247 	struct ipv6_pinfo *np = NULL;
248 #endif
249 
250 	hdr = genlmsg_put(skb, portid, seq, &l2tp_nl_family, flags,
251 			  L2TP_CMD_TUNNEL_GET);
252 	if (!hdr)
253 		return -EMSGSIZE;
254 
255 	if (nla_put_u8(skb, L2TP_ATTR_PROTO_VERSION, tunnel->version) ||
256 	    nla_put_u32(skb, L2TP_ATTR_CONN_ID, tunnel->tunnel_id) ||
257 	    nla_put_u32(skb, L2TP_ATTR_PEER_CONN_ID, tunnel->peer_tunnel_id) ||
258 	    nla_put_u32(skb, L2TP_ATTR_DEBUG, tunnel->debug) ||
259 	    nla_put_u16(skb, L2TP_ATTR_ENCAP_TYPE, tunnel->encap))
260 		goto nla_put_failure;
261 
262 	nest = nla_nest_start(skb, L2TP_ATTR_STATS);
263 	if (nest == NULL)
264 		goto nla_put_failure;
265 
266 	if (nla_put_u64(skb, L2TP_ATTR_TX_PACKETS,
267 		    atomic_long_read(&tunnel->stats.tx_packets)) ||
268 	    nla_put_u64(skb, L2TP_ATTR_TX_BYTES,
269 		    atomic_long_read(&tunnel->stats.tx_bytes)) ||
270 	    nla_put_u64(skb, L2TP_ATTR_TX_ERRORS,
271 		    atomic_long_read(&tunnel->stats.tx_errors)) ||
272 	    nla_put_u64(skb, L2TP_ATTR_RX_PACKETS,
273 		    atomic_long_read(&tunnel->stats.rx_packets)) ||
274 	    nla_put_u64(skb, L2TP_ATTR_RX_BYTES,
275 		    atomic_long_read(&tunnel->stats.rx_bytes)) ||
276 	    nla_put_u64(skb, L2TP_ATTR_RX_SEQ_DISCARDS,
277 		    atomic_long_read(&tunnel->stats.rx_seq_discards)) ||
278 	    nla_put_u64(skb, L2TP_ATTR_RX_OOS_PACKETS,
279 		    atomic_long_read(&tunnel->stats.rx_oos_packets)) ||
280 	    nla_put_u64(skb, L2TP_ATTR_RX_ERRORS,
281 		    atomic_long_read(&tunnel->stats.rx_errors)))
282 		goto nla_put_failure;
283 	nla_nest_end(skb, nest);
284 
285 	sk = tunnel->sock;
286 	if (!sk)
287 		goto out;
288 
289 #if IS_ENABLED(CONFIG_IPV6)
290 	if (sk->sk_family == AF_INET6)
291 		np = inet6_sk(sk);
292 #endif
293 
294 	inet = inet_sk(sk);
295 
296 	switch (tunnel->encap) {
297 	case L2TP_ENCAPTYPE_UDP:
298 		if (nla_put_u16(skb, L2TP_ATTR_UDP_SPORT, ntohs(inet->inet_sport)) ||
299 		    nla_put_u16(skb, L2TP_ATTR_UDP_DPORT, ntohs(inet->inet_dport)) ||
300 		    nla_put_u8(skb, L2TP_ATTR_UDP_CSUM,
301 			       (sk->sk_no_check != UDP_CSUM_NOXMIT)))
302 			goto nla_put_failure;
303 		/* NOBREAK */
304 	case L2TP_ENCAPTYPE_IP:
305 #if IS_ENABLED(CONFIG_IPV6)
306 		if (np) {
307 			if (nla_put(skb, L2TP_ATTR_IP6_SADDR, sizeof(np->saddr),
308 				    &np->saddr) ||
309 			    nla_put(skb, L2TP_ATTR_IP6_DADDR, sizeof(sk->sk_v6_daddr),
310 				    &sk->sk_v6_daddr))
311 				goto nla_put_failure;
312 		} else
313 #endif
314 		if (nla_put_be32(skb, L2TP_ATTR_IP_SADDR, inet->inet_saddr) ||
315 		    nla_put_be32(skb, L2TP_ATTR_IP_DADDR, inet->inet_daddr))
316 			goto nla_put_failure;
317 		break;
318 	}
319 
320 out:
321 	return genlmsg_end(skb, hdr);
322 
323 nla_put_failure:
324 	genlmsg_cancel(skb, hdr);
325 	return -1;
326 }
327 
328 static int l2tp_nl_cmd_tunnel_get(struct sk_buff *skb, struct genl_info *info)
329 {
330 	struct l2tp_tunnel *tunnel;
331 	struct sk_buff *msg;
332 	u32 tunnel_id;
333 	int ret = -ENOBUFS;
334 	struct net *net = genl_info_net(info);
335 
336 	if (!info->attrs[L2TP_ATTR_CONN_ID]) {
337 		ret = -EINVAL;
338 		goto out;
339 	}
340 
341 	tunnel_id = nla_get_u32(info->attrs[L2TP_ATTR_CONN_ID]);
342 
343 	tunnel = l2tp_tunnel_find(net, tunnel_id);
344 	if (tunnel == NULL) {
345 		ret = -ENODEV;
346 		goto out;
347 	}
348 
349 	msg = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);
350 	if (!msg) {
351 		ret = -ENOMEM;
352 		goto out;
353 	}
354 
355 	ret = l2tp_nl_tunnel_send(msg, info->snd_portid, info->snd_seq,
356 				  NLM_F_ACK, tunnel);
357 	if (ret < 0)
358 		goto err_out;
359 
360 	return genlmsg_unicast(net, msg, info->snd_portid);
361 
362 err_out:
363 	nlmsg_free(msg);
364 
365 out:
366 	return ret;
367 }
368 
369 static int l2tp_nl_cmd_tunnel_dump(struct sk_buff *skb, struct netlink_callback *cb)
370 {
371 	int ti = cb->args[0];
372 	struct l2tp_tunnel *tunnel;
373 	struct net *net = sock_net(skb->sk);
374 
375 	for (;;) {
376 		tunnel = l2tp_tunnel_find_nth(net, ti);
377 		if (tunnel == NULL)
378 			goto out;
379 
380 		if (l2tp_nl_tunnel_send(skb, NETLINK_CB(cb->skb).portid,
381 					cb->nlh->nlmsg_seq, NLM_F_MULTI,
382 					tunnel) <= 0)
383 			goto out;
384 
385 		ti++;
386 	}
387 
388 out:
389 	cb->args[0] = ti;
390 
391 	return skb->len;
392 }
393 
394 static int l2tp_nl_cmd_session_create(struct sk_buff *skb, struct genl_info *info)
395 {
396 	u32 tunnel_id = 0;
397 	u32 session_id;
398 	u32 peer_session_id;
399 	int ret = 0;
400 	struct l2tp_tunnel *tunnel;
401 	struct l2tp_session *session;
402 	struct l2tp_session_cfg cfg = { 0, };
403 	struct net *net = genl_info_net(info);
404 
405 	if (!info->attrs[L2TP_ATTR_CONN_ID]) {
406 		ret = -EINVAL;
407 		goto out;
408 	}
409 	tunnel_id = nla_get_u32(info->attrs[L2TP_ATTR_CONN_ID]);
410 	tunnel = l2tp_tunnel_find(net, tunnel_id);
411 	if (!tunnel) {
412 		ret = -ENODEV;
413 		goto out;
414 	}
415 
416 	if (!info->attrs[L2TP_ATTR_SESSION_ID]) {
417 		ret = -EINVAL;
418 		goto out;
419 	}
420 	session_id = nla_get_u32(info->attrs[L2TP_ATTR_SESSION_ID]);
421 	session = l2tp_session_find(net, tunnel, session_id);
422 	if (session) {
423 		ret = -EEXIST;
424 		goto out;
425 	}
426 
427 	if (!info->attrs[L2TP_ATTR_PEER_SESSION_ID]) {
428 		ret = -EINVAL;
429 		goto out;
430 	}
431 	peer_session_id = nla_get_u32(info->attrs[L2TP_ATTR_PEER_SESSION_ID]);
432 
433 	if (!info->attrs[L2TP_ATTR_PW_TYPE]) {
434 		ret = -EINVAL;
435 		goto out;
436 	}
437 	cfg.pw_type = nla_get_u16(info->attrs[L2TP_ATTR_PW_TYPE]);
438 	if (cfg.pw_type >= __L2TP_PWTYPE_MAX) {
439 		ret = -EINVAL;
440 		goto out;
441 	}
442 
443 	if (tunnel->version > 2) {
444 		if (info->attrs[L2TP_ATTR_OFFSET])
445 			cfg.offset = nla_get_u16(info->attrs[L2TP_ATTR_OFFSET]);
446 
447 		if (info->attrs[L2TP_ATTR_DATA_SEQ])
448 			cfg.data_seq = nla_get_u8(info->attrs[L2TP_ATTR_DATA_SEQ]);
449 
450 		cfg.l2specific_type = L2TP_L2SPECTYPE_DEFAULT;
451 		if (info->attrs[L2TP_ATTR_L2SPEC_TYPE])
452 			cfg.l2specific_type = nla_get_u8(info->attrs[L2TP_ATTR_L2SPEC_TYPE]);
453 
454 		cfg.l2specific_len = 4;
455 		if (info->attrs[L2TP_ATTR_L2SPEC_LEN])
456 			cfg.l2specific_len = nla_get_u8(info->attrs[L2TP_ATTR_L2SPEC_LEN]);
457 
458 		if (info->attrs[L2TP_ATTR_COOKIE]) {
459 			u16 len = nla_len(info->attrs[L2TP_ATTR_COOKIE]);
460 			if (len > 8) {
461 				ret = -EINVAL;
462 				goto out;
463 			}
464 			cfg.cookie_len = len;
465 			memcpy(&cfg.cookie[0], nla_data(info->attrs[L2TP_ATTR_COOKIE]), len);
466 		}
467 		if (info->attrs[L2TP_ATTR_PEER_COOKIE]) {
468 			u16 len = nla_len(info->attrs[L2TP_ATTR_PEER_COOKIE]);
469 			if (len > 8) {
470 				ret = -EINVAL;
471 				goto out;
472 			}
473 			cfg.peer_cookie_len = len;
474 			memcpy(&cfg.peer_cookie[0], nla_data(info->attrs[L2TP_ATTR_PEER_COOKIE]), len);
475 		}
476 		if (info->attrs[L2TP_ATTR_IFNAME])
477 			cfg.ifname = nla_data(info->attrs[L2TP_ATTR_IFNAME]);
478 
479 		if (info->attrs[L2TP_ATTR_VLAN_ID])
480 			cfg.vlan_id = nla_get_u16(info->attrs[L2TP_ATTR_VLAN_ID]);
481 	}
482 
483 	if (info->attrs[L2TP_ATTR_DEBUG])
484 		cfg.debug = nla_get_u32(info->attrs[L2TP_ATTR_DEBUG]);
485 
486 	if (info->attrs[L2TP_ATTR_RECV_SEQ])
487 		cfg.recv_seq = nla_get_u8(info->attrs[L2TP_ATTR_RECV_SEQ]);
488 
489 	if (info->attrs[L2TP_ATTR_SEND_SEQ])
490 		cfg.send_seq = nla_get_u8(info->attrs[L2TP_ATTR_SEND_SEQ]);
491 
492 	if (info->attrs[L2TP_ATTR_LNS_MODE])
493 		cfg.lns_mode = nla_get_u8(info->attrs[L2TP_ATTR_LNS_MODE]);
494 
495 	if (info->attrs[L2TP_ATTR_RECV_TIMEOUT])
496 		cfg.reorder_timeout = nla_get_msecs(info->attrs[L2TP_ATTR_RECV_TIMEOUT]);
497 
498 	if (info->attrs[L2TP_ATTR_MTU])
499 		cfg.mtu = nla_get_u16(info->attrs[L2TP_ATTR_MTU]);
500 
501 	if (info->attrs[L2TP_ATTR_MRU])
502 		cfg.mru = nla_get_u16(info->attrs[L2TP_ATTR_MRU]);
503 
504 	if ((l2tp_nl_cmd_ops[cfg.pw_type] == NULL) ||
505 	    (l2tp_nl_cmd_ops[cfg.pw_type]->session_create == NULL)) {
506 		ret = -EPROTONOSUPPORT;
507 		goto out;
508 	}
509 
510 	/* Check that pseudowire-specific params are present */
511 	switch (cfg.pw_type) {
512 	case L2TP_PWTYPE_NONE:
513 		break;
514 	case L2TP_PWTYPE_ETH_VLAN:
515 		if (!info->attrs[L2TP_ATTR_VLAN_ID]) {
516 			ret = -EINVAL;
517 			goto out;
518 		}
519 		break;
520 	case L2TP_PWTYPE_ETH:
521 		break;
522 	case L2TP_PWTYPE_PPP:
523 	case L2TP_PWTYPE_PPP_AC:
524 		break;
525 	case L2TP_PWTYPE_IP:
526 	default:
527 		ret = -EPROTONOSUPPORT;
528 		break;
529 	}
530 
531 	ret = -EPROTONOSUPPORT;
532 	if (l2tp_nl_cmd_ops[cfg.pw_type]->session_create)
533 		ret = (*l2tp_nl_cmd_ops[cfg.pw_type]->session_create)(net, tunnel_id,
534 			session_id, peer_session_id, &cfg);
535 
536 out:
537 	return ret;
538 }
539 
540 static int l2tp_nl_cmd_session_delete(struct sk_buff *skb, struct genl_info *info)
541 {
542 	int ret = 0;
543 	struct l2tp_session *session;
544 	u16 pw_type;
545 
546 	session = l2tp_nl_session_find(info);
547 	if (session == NULL) {
548 		ret = -ENODEV;
549 		goto out;
550 	}
551 
552 	pw_type = session->pwtype;
553 	if (pw_type < __L2TP_PWTYPE_MAX)
554 		if (l2tp_nl_cmd_ops[pw_type] && l2tp_nl_cmd_ops[pw_type]->session_delete)
555 			ret = (*l2tp_nl_cmd_ops[pw_type]->session_delete)(session);
556 
557 out:
558 	return ret;
559 }
560 
561 static int l2tp_nl_cmd_session_modify(struct sk_buff *skb, struct genl_info *info)
562 {
563 	int ret = 0;
564 	struct l2tp_session *session;
565 
566 	session = l2tp_nl_session_find(info);
567 	if (session == NULL) {
568 		ret = -ENODEV;
569 		goto out;
570 	}
571 
572 	if (info->attrs[L2TP_ATTR_DEBUG])
573 		session->debug = nla_get_u32(info->attrs[L2TP_ATTR_DEBUG]);
574 
575 	if (info->attrs[L2TP_ATTR_DATA_SEQ])
576 		session->data_seq = nla_get_u8(info->attrs[L2TP_ATTR_DATA_SEQ]);
577 
578 	if (info->attrs[L2TP_ATTR_RECV_SEQ])
579 		session->recv_seq = nla_get_u8(info->attrs[L2TP_ATTR_RECV_SEQ]);
580 
581 	if (info->attrs[L2TP_ATTR_SEND_SEQ])
582 		session->send_seq = nla_get_u8(info->attrs[L2TP_ATTR_SEND_SEQ]);
583 
584 	if (info->attrs[L2TP_ATTR_LNS_MODE])
585 		session->lns_mode = nla_get_u8(info->attrs[L2TP_ATTR_LNS_MODE]);
586 
587 	if (info->attrs[L2TP_ATTR_RECV_TIMEOUT])
588 		session->reorder_timeout = nla_get_msecs(info->attrs[L2TP_ATTR_RECV_TIMEOUT]);
589 
590 	if (info->attrs[L2TP_ATTR_MTU])
591 		session->mtu = nla_get_u16(info->attrs[L2TP_ATTR_MTU]);
592 
593 	if (info->attrs[L2TP_ATTR_MRU])
594 		session->mru = nla_get_u16(info->attrs[L2TP_ATTR_MRU]);
595 
596 out:
597 	return ret;
598 }
599 
600 static int l2tp_nl_session_send(struct sk_buff *skb, u32 portid, u32 seq, int flags,
601 				struct l2tp_session *session)
602 {
603 	void *hdr;
604 	struct nlattr *nest;
605 	struct l2tp_tunnel *tunnel = session->tunnel;
606 	struct sock *sk = NULL;
607 
608 	sk = tunnel->sock;
609 
610 	hdr = genlmsg_put(skb, portid, seq, &l2tp_nl_family, flags, L2TP_CMD_SESSION_GET);
611 	if (!hdr)
612 		return -EMSGSIZE;
613 
614 	if (nla_put_u32(skb, L2TP_ATTR_CONN_ID, tunnel->tunnel_id) ||
615 	    nla_put_u32(skb, L2TP_ATTR_SESSION_ID, session->session_id) ||
616 	    nla_put_u32(skb, L2TP_ATTR_PEER_CONN_ID, tunnel->peer_tunnel_id) ||
617 	    nla_put_u32(skb, L2TP_ATTR_PEER_SESSION_ID,
618 			session->peer_session_id) ||
619 	    nla_put_u32(skb, L2TP_ATTR_DEBUG, session->debug) ||
620 	    nla_put_u16(skb, L2TP_ATTR_PW_TYPE, session->pwtype) ||
621 	    nla_put_u16(skb, L2TP_ATTR_MTU, session->mtu) ||
622 	    (session->mru &&
623 	     nla_put_u16(skb, L2TP_ATTR_MRU, session->mru)))
624 		goto nla_put_failure;
625 
626 	if ((session->ifname[0] &&
627 	     nla_put_string(skb, L2TP_ATTR_IFNAME, session->ifname)) ||
628 	    (session->cookie_len &&
629 	     nla_put(skb, L2TP_ATTR_COOKIE, session->cookie_len,
630 		     &session->cookie[0])) ||
631 	    (session->peer_cookie_len &&
632 	     nla_put(skb, L2TP_ATTR_PEER_COOKIE, session->peer_cookie_len,
633 		     &session->peer_cookie[0])) ||
634 	    nla_put_u8(skb, L2TP_ATTR_RECV_SEQ, session->recv_seq) ||
635 	    nla_put_u8(skb, L2TP_ATTR_SEND_SEQ, session->send_seq) ||
636 	    nla_put_u8(skb, L2TP_ATTR_LNS_MODE, session->lns_mode) ||
637 #ifdef CONFIG_XFRM
638 	    (((sk) && (sk->sk_policy[0] || sk->sk_policy[1])) &&
639 	     nla_put_u8(skb, L2TP_ATTR_USING_IPSEC, 1)) ||
640 #endif
641 	    (session->reorder_timeout &&
642 	     nla_put_msecs(skb, L2TP_ATTR_RECV_TIMEOUT, session->reorder_timeout)))
643 		goto nla_put_failure;
644 
645 	nest = nla_nest_start(skb, L2TP_ATTR_STATS);
646 	if (nest == NULL)
647 		goto nla_put_failure;
648 
649 	if (nla_put_u64(skb, L2TP_ATTR_TX_PACKETS,
650 		atomic_long_read(&session->stats.tx_packets)) ||
651 	    nla_put_u64(skb, L2TP_ATTR_TX_BYTES,
652 		atomic_long_read(&session->stats.tx_bytes)) ||
653 	    nla_put_u64(skb, L2TP_ATTR_TX_ERRORS,
654 		atomic_long_read(&session->stats.tx_errors)) ||
655 	    nla_put_u64(skb, L2TP_ATTR_RX_PACKETS,
656 		atomic_long_read(&session->stats.rx_packets)) ||
657 	    nla_put_u64(skb, L2TP_ATTR_RX_BYTES,
658 		atomic_long_read(&session->stats.rx_bytes)) ||
659 	    nla_put_u64(skb, L2TP_ATTR_RX_SEQ_DISCARDS,
660 		atomic_long_read(&session->stats.rx_seq_discards)) ||
661 	    nla_put_u64(skb, L2TP_ATTR_RX_OOS_PACKETS,
662 		atomic_long_read(&session->stats.rx_oos_packets)) ||
663 	    nla_put_u64(skb, L2TP_ATTR_RX_ERRORS,
664 		atomic_long_read(&session->stats.rx_errors)))
665 		goto nla_put_failure;
666 	nla_nest_end(skb, nest);
667 
668 	return genlmsg_end(skb, hdr);
669 
670  nla_put_failure:
671 	genlmsg_cancel(skb, hdr);
672 	return -1;
673 }
674 
675 static int l2tp_nl_cmd_session_get(struct sk_buff *skb, struct genl_info *info)
676 {
677 	struct l2tp_session *session;
678 	struct sk_buff *msg;
679 	int ret;
680 
681 	session = l2tp_nl_session_find(info);
682 	if (session == NULL) {
683 		ret = -ENODEV;
684 		goto out;
685 	}
686 
687 	msg = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);
688 	if (!msg) {
689 		ret = -ENOMEM;
690 		goto out;
691 	}
692 
693 	ret = l2tp_nl_session_send(msg, info->snd_portid, info->snd_seq,
694 				   0, session);
695 	if (ret < 0)
696 		goto err_out;
697 
698 	return genlmsg_unicast(genl_info_net(info), msg, info->snd_portid);
699 
700 err_out:
701 	nlmsg_free(msg);
702 
703 out:
704 	return ret;
705 }
706 
707 static int l2tp_nl_cmd_session_dump(struct sk_buff *skb, struct netlink_callback *cb)
708 {
709 	struct net *net = sock_net(skb->sk);
710 	struct l2tp_session *session;
711 	struct l2tp_tunnel *tunnel = NULL;
712 	int ti = cb->args[0];
713 	int si = cb->args[1];
714 
715 	for (;;) {
716 		if (tunnel == NULL) {
717 			tunnel = l2tp_tunnel_find_nth(net, ti);
718 			if (tunnel == NULL)
719 				goto out;
720 		}
721 
722 		session = l2tp_session_find_nth(tunnel, si);
723 		if (session == NULL) {
724 			ti++;
725 			tunnel = NULL;
726 			si = 0;
727 			continue;
728 		}
729 
730 		if (l2tp_nl_session_send(skb, NETLINK_CB(cb->skb).portid,
731 					 cb->nlh->nlmsg_seq, NLM_F_MULTI,
732 					 session) <= 0)
733 			break;
734 
735 		si++;
736 	}
737 
738 out:
739 	cb->args[0] = ti;
740 	cb->args[1] = si;
741 
742 	return skb->len;
743 }
744 
745 static struct nla_policy l2tp_nl_policy[L2TP_ATTR_MAX + 1] = {
746 	[L2TP_ATTR_NONE]		= { .type = NLA_UNSPEC, },
747 	[L2TP_ATTR_PW_TYPE]		= { .type = NLA_U16, },
748 	[L2TP_ATTR_ENCAP_TYPE]		= { .type = NLA_U16, },
749 	[L2TP_ATTR_OFFSET]		= { .type = NLA_U16, },
750 	[L2TP_ATTR_DATA_SEQ]		= { .type = NLA_U8, },
751 	[L2TP_ATTR_L2SPEC_TYPE]		= { .type = NLA_U8, },
752 	[L2TP_ATTR_L2SPEC_LEN]		= { .type = NLA_U8, },
753 	[L2TP_ATTR_PROTO_VERSION]	= { .type = NLA_U8, },
754 	[L2TP_ATTR_CONN_ID]		= { .type = NLA_U32, },
755 	[L2TP_ATTR_PEER_CONN_ID]	= { .type = NLA_U32, },
756 	[L2TP_ATTR_SESSION_ID]		= { .type = NLA_U32, },
757 	[L2TP_ATTR_PEER_SESSION_ID]	= { .type = NLA_U32, },
758 	[L2TP_ATTR_UDP_CSUM]		= { .type = NLA_U8, },
759 	[L2TP_ATTR_VLAN_ID]		= { .type = NLA_U16, },
760 	[L2TP_ATTR_DEBUG]		= { .type = NLA_U32, },
761 	[L2TP_ATTR_RECV_SEQ]		= { .type = NLA_U8, },
762 	[L2TP_ATTR_SEND_SEQ]		= { .type = NLA_U8, },
763 	[L2TP_ATTR_LNS_MODE]		= { .type = NLA_U8, },
764 	[L2TP_ATTR_USING_IPSEC]		= { .type = NLA_U8, },
765 	[L2TP_ATTR_RECV_TIMEOUT]	= { .type = NLA_MSECS, },
766 	[L2TP_ATTR_FD]			= { .type = NLA_U32, },
767 	[L2TP_ATTR_IP_SADDR]		= { .type = NLA_U32, },
768 	[L2TP_ATTR_IP_DADDR]		= { .type = NLA_U32, },
769 	[L2TP_ATTR_UDP_SPORT]		= { .type = NLA_U16, },
770 	[L2TP_ATTR_UDP_DPORT]		= { .type = NLA_U16, },
771 	[L2TP_ATTR_MTU]			= { .type = NLA_U16, },
772 	[L2TP_ATTR_MRU]			= { .type = NLA_U16, },
773 	[L2TP_ATTR_STATS]		= { .type = NLA_NESTED, },
774 	[L2TP_ATTR_IP6_SADDR] = {
775 		.type = NLA_BINARY,
776 		.len = sizeof(struct in6_addr),
777 	},
778 	[L2TP_ATTR_IP6_DADDR] = {
779 		.type = NLA_BINARY,
780 		.len = sizeof(struct in6_addr),
781 	},
782 	[L2TP_ATTR_IFNAME] = {
783 		.type = NLA_NUL_STRING,
784 		.len = IFNAMSIZ - 1,
785 	},
786 	[L2TP_ATTR_COOKIE] = {
787 		.type = NLA_BINARY,
788 		.len = 8,
789 	},
790 	[L2TP_ATTR_PEER_COOKIE] = {
791 		.type = NLA_BINARY,
792 		.len = 8,
793 	},
794 };
795 
796 static const struct genl_ops l2tp_nl_ops[] = {
797 	{
798 		.cmd = L2TP_CMD_NOOP,
799 		.doit = l2tp_nl_cmd_noop,
800 		.policy = l2tp_nl_policy,
801 		/* can be retrieved by unprivileged users */
802 	},
803 	{
804 		.cmd = L2TP_CMD_TUNNEL_CREATE,
805 		.doit = l2tp_nl_cmd_tunnel_create,
806 		.policy = l2tp_nl_policy,
807 		.flags = GENL_ADMIN_PERM,
808 	},
809 	{
810 		.cmd = L2TP_CMD_TUNNEL_DELETE,
811 		.doit = l2tp_nl_cmd_tunnel_delete,
812 		.policy = l2tp_nl_policy,
813 		.flags = GENL_ADMIN_PERM,
814 	},
815 	{
816 		.cmd = L2TP_CMD_TUNNEL_MODIFY,
817 		.doit = l2tp_nl_cmd_tunnel_modify,
818 		.policy = l2tp_nl_policy,
819 		.flags = GENL_ADMIN_PERM,
820 	},
821 	{
822 		.cmd = L2TP_CMD_TUNNEL_GET,
823 		.doit = l2tp_nl_cmd_tunnel_get,
824 		.dumpit = l2tp_nl_cmd_tunnel_dump,
825 		.policy = l2tp_nl_policy,
826 		.flags = GENL_ADMIN_PERM,
827 	},
828 	{
829 		.cmd = L2TP_CMD_SESSION_CREATE,
830 		.doit = l2tp_nl_cmd_session_create,
831 		.policy = l2tp_nl_policy,
832 		.flags = GENL_ADMIN_PERM,
833 	},
834 	{
835 		.cmd = L2TP_CMD_SESSION_DELETE,
836 		.doit = l2tp_nl_cmd_session_delete,
837 		.policy = l2tp_nl_policy,
838 		.flags = GENL_ADMIN_PERM,
839 	},
840 	{
841 		.cmd = L2TP_CMD_SESSION_MODIFY,
842 		.doit = l2tp_nl_cmd_session_modify,
843 		.policy = l2tp_nl_policy,
844 		.flags = GENL_ADMIN_PERM,
845 	},
846 	{
847 		.cmd = L2TP_CMD_SESSION_GET,
848 		.doit = l2tp_nl_cmd_session_get,
849 		.dumpit = l2tp_nl_cmd_session_dump,
850 		.policy = l2tp_nl_policy,
851 		.flags = GENL_ADMIN_PERM,
852 	},
853 };
854 
855 int l2tp_nl_register_ops(enum l2tp_pwtype pw_type, const struct l2tp_nl_cmd_ops *ops)
856 {
857 	int ret;
858 
859 	ret = -EINVAL;
860 	if (pw_type >= __L2TP_PWTYPE_MAX)
861 		goto err;
862 
863 	genl_lock();
864 	ret = -EBUSY;
865 	if (l2tp_nl_cmd_ops[pw_type])
866 		goto out;
867 
868 	l2tp_nl_cmd_ops[pw_type] = ops;
869 	ret = 0;
870 
871 out:
872 	genl_unlock();
873 err:
874 	return ret;
875 }
876 EXPORT_SYMBOL_GPL(l2tp_nl_register_ops);
877 
878 void l2tp_nl_unregister_ops(enum l2tp_pwtype pw_type)
879 {
880 	if (pw_type < __L2TP_PWTYPE_MAX) {
881 		genl_lock();
882 		l2tp_nl_cmd_ops[pw_type] = NULL;
883 		genl_unlock();
884 	}
885 }
886 EXPORT_SYMBOL_GPL(l2tp_nl_unregister_ops);
887 
888 static int l2tp_nl_init(void)
889 {
890 	pr_info("L2TP netlink interface\n");
891 	return genl_register_family_with_ops(&l2tp_nl_family, l2tp_nl_ops);
892 }
893 
894 static void l2tp_nl_cleanup(void)
895 {
896 	genl_unregister_family(&l2tp_nl_family);
897 }
898 
899 module_init(l2tp_nl_init);
900 module_exit(l2tp_nl_cleanup);
901 
902 MODULE_AUTHOR("James Chapman <jchapman@katalix.com>");
903 MODULE_DESCRIPTION("L2TP netlink");
904 MODULE_LICENSE("GPL");
905 MODULE_VERSION("1.0");
906 MODULE_ALIAS_GENL_FAMILY("l2tp");
907