xref: /linux/net/l2tp/l2tp_netlink.c (revision 61d0b5a4b2777dcf5daef245e212b3c1fa8091ca)
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 	struct l2tp_stats stats;
250 	unsigned int start;
251 
252 	hdr = genlmsg_put(skb, portid, seq, &l2tp_nl_family, flags,
253 			  L2TP_CMD_TUNNEL_GET);
254 	if (!hdr)
255 		return -EMSGSIZE;
256 
257 	if (nla_put_u8(skb, L2TP_ATTR_PROTO_VERSION, tunnel->version) ||
258 	    nla_put_u32(skb, L2TP_ATTR_CONN_ID, tunnel->tunnel_id) ||
259 	    nla_put_u32(skb, L2TP_ATTR_PEER_CONN_ID, tunnel->peer_tunnel_id) ||
260 	    nla_put_u32(skb, L2TP_ATTR_DEBUG, tunnel->debug) ||
261 	    nla_put_u16(skb, L2TP_ATTR_ENCAP_TYPE, tunnel->encap))
262 		goto nla_put_failure;
263 
264 	nest = nla_nest_start(skb, L2TP_ATTR_STATS);
265 	if (nest == NULL)
266 		goto nla_put_failure;
267 
268 	do {
269 		start = u64_stats_fetch_begin(&tunnel->stats.syncp);
270 		stats.tx_packets = tunnel->stats.tx_packets;
271 		stats.tx_bytes = tunnel->stats.tx_bytes;
272 		stats.tx_errors = tunnel->stats.tx_errors;
273 		stats.rx_packets = tunnel->stats.rx_packets;
274 		stats.rx_bytes = tunnel->stats.rx_bytes;
275 		stats.rx_errors = tunnel->stats.rx_errors;
276 		stats.rx_seq_discards = tunnel->stats.rx_seq_discards;
277 		stats.rx_oos_packets = tunnel->stats.rx_oos_packets;
278 	} while (u64_stats_fetch_retry(&tunnel->stats.syncp, start));
279 
280 	if (nla_put_u64(skb, L2TP_ATTR_TX_PACKETS, stats.tx_packets) ||
281 	    nla_put_u64(skb, L2TP_ATTR_TX_BYTES, stats.tx_bytes) ||
282 	    nla_put_u64(skb, L2TP_ATTR_TX_ERRORS, stats.tx_errors) ||
283 	    nla_put_u64(skb, L2TP_ATTR_RX_PACKETS, stats.rx_packets) ||
284 	    nla_put_u64(skb, L2TP_ATTR_RX_BYTES, stats.rx_bytes) ||
285 	    nla_put_u64(skb, L2TP_ATTR_RX_SEQ_DISCARDS,
286 			stats.rx_seq_discards) ||
287 	    nla_put_u64(skb, L2TP_ATTR_RX_OOS_PACKETS,
288 			stats.rx_oos_packets) ||
289 	    nla_put_u64(skb, L2TP_ATTR_RX_ERRORS, stats.rx_errors))
290 		goto nla_put_failure;
291 	nla_nest_end(skb, nest);
292 
293 	sk = tunnel->sock;
294 	if (!sk)
295 		goto out;
296 
297 #if IS_ENABLED(CONFIG_IPV6)
298 	if (sk->sk_family == AF_INET6)
299 		np = inet6_sk(sk);
300 #endif
301 
302 	inet = inet_sk(sk);
303 
304 	switch (tunnel->encap) {
305 	case L2TP_ENCAPTYPE_UDP:
306 		if (nla_put_u16(skb, L2TP_ATTR_UDP_SPORT, ntohs(inet->inet_sport)) ||
307 		    nla_put_u16(skb, L2TP_ATTR_UDP_DPORT, ntohs(inet->inet_dport)) ||
308 		    nla_put_u8(skb, L2TP_ATTR_UDP_CSUM,
309 			       (sk->sk_no_check != UDP_CSUM_NOXMIT)))
310 			goto nla_put_failure;
311 		/* NOBREAK */
312 	case L2TP_ENCAPTYPE_IP:
313 #if IS_ENABLED(CONFIG_IPV6)
314 		if (np) {
315 			if (nla_put(skb, L2TP_ATTR_IP6_SADDR, sizeof(np->saddr),
316 				    &np->saddr) ||
317 			    nla_put(skb, L2TP_ATTR_IP6_DADDR, sizeof(np->daddr),
318 				    &np->daddr))
319 				goto nla_put_failure;
320 		} else
321 #endif
322 		if (nla_put_be32(skb, L2TP_ATTR_IP_SADDR, inet->inet_saddr) ||
323 		    nla_put_be32(skb, L2TP_ATTR_IP_DADDR, inet->inet_daddr))
324 			goto nla_put_failure;
325 		break;
326 	}
327 
328 out:
329 	return genlmsg_end(skb, hdr);
330 
331 nla_put_failure:
332 	genlmsg_cancel(skb, hdr);
333 	return -1;
334 }
335 
336 static int l2tp_nl_cmd_tunnel_get(struct sk_buff *skb, struct genl_info *info)
337 {
338 	struct l2tp_tunnel *tunnel;
339 	struct sk_buff *msg;
340 	u32 tunnel_id;
341 	int ret = -ENOBUFS;
342 	struct net *net = genl_info_net(info);
343 
344 	if (!info->attrs[L2TP_ATTR_CONN_ID]) {
345 		ret = -EINVAL;
346 		goto out;
347 	}
348 
349 	tunnel_id = nla_get_u32(info->attrs[L2TP_ATTR_CONN_ID]);
350 
351 	tunnel = l2tp_tunnel_find(net, tunnel_id);
352 	if (tunnel == NULL) {
353 		ret = -ENODEV;
354 		goto out;
355 	}
356 
357 	msg = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);
358 	if (!msg) {
359 		ret = -ENOMEM;
360 		goto out;
361 	}
362 
363 	ret = l2tp_nl_tunnel_send(msg, info->snd_portid, info->snd_seq,
364 				  NLM_F_ACK, tunnel);
365 	if (ret < 0)
366 		goto err_out;
367 
368 	return genlmsg_unicast(net, msg, info->snd_portid);
369 
370 err_out:
371 	nlmsg_free(msg);
372 
373 out:
374 	return ret;
375 }
376 
377 static int l2tp_nl_cmd_tunnel_dump(struct sk_buff *skb, struct netlink_callback *cb)
378 {
379 	int ti = cb->args[0];
380 	struct l2tp_tunnel *tunnel;
381 	struct net *net = sock_net(skb->sk);
382 
383 	for (;;) {
384 		tunnel = l2tp_tunnel_find_nth(net, ti);
385 		if (tunnel == NULL)
386 			goto out;
387 
388 		if (l2tp_nl_tunnel_send(skb, NETLINK_CB(cb->skb).portid,
389 					cb->nlh->nlmsg_seq, NLM_F_MULTI,
390 					tunnel) <= 0)
391 			goto out;
392 
393 		ti++;
394 	}
395 
396 out:
397 	cb->args[0] = ti;
398 
399 	return skb->len;
400 }
401 
402 static int l2tp_nl_cmd_session_create(struct sk_buff *skb, struct genl_info *info)
403 {
404 	u32 tunnel_id = 0;
405 	u32 session_id;
406 	u32 peer_session_id;
407 	int ret = 0;
408 	struct l2tp_tunnel *tunnel;
409 	struct l2tp_session *session;
410 	struct l2tp_session_cfg cfg = { 0, };
411 	struct net *net = genl_info_net(info);
412 
413 	if (!info->attrs[L2TP_ATTR_CONN_ID]) {
414 		ret = -EINVAL;
415 		goto out;
416 	}
417 	tunnel_id = nla_get_u32(info->attrs[L2TP_ATTR_CONN_ID]);
418 	tunnel = l2tp_tunnel_find(net, tunnel_id);
419 	if (!tunnel) {
420 		ret = -ENODEV;
421 		goto out;
422 	}
423 
424 	if (!info->attrs[L2TP_ATTR_SESSION_ID]) {
425 		ret = -EINVAL;
426 		goto out;
427 	}
428 	session_id = nla_get_u32(info->attrs[L2TP_ATTR_SESSION_ID]);
429 	session = l2tp_session_find(net, tunnel, session_id);
430 	if (session) {
431 		ret = -EEXIST;
432 		goto out;
433 	}
434 
435 	if (!info->attrs[L2TP_ATTR_PEER_SESSION_ID]) {
436 		ret = -EINVAL;
437 		goto out;
438 	}
439 	peer_session_id = nla_get_u32(info->attrs[L2TP_ATTR_PEER_SESSION_ID]);
440 
441 	if (!info->attrs[L2TP_ATTR_PW_TYPE]) {
442 		ret = -EINVAL;
443 		goto out;
444 	}
445 	cfg.pw_type = nla_get_u16(info->attrs[L2TP_ATTR_PW_TYPE]);
446 	if (cfg.pw_type >= __L2TP_PWTYPE_MAX) {
447 		ret = -EINVAL;
448 		goto out;
449 	}
450 
451 	if (tunnel->version > 2) {
452 		if (info->attrs[L2TP_ATTR_OFFSET])
453 			cfg.offset = nla_get_u16(info->attrs[L2TP_ATTR_OFFSET]);
454 
455 		if (info->attrs[L2TP_ATTR_DATA_SEQ])
456 			cfg.data_seq = nla_get_u8(info->attrs[L2TP_ATTR_DATA_SEQ]);
457 
458 		cfg.l2specific_type = L2TP_L2SPECTYPE_DEFAULT;
459 		if (info->attrs[L2TP_ATTR_L2SPEC_TYPE])
460 			cfg.l2specific_type = nla_get_u8(info->attrs[L2TP_ATTR_L2SPEC_TYPE]);
461 
462 		cfg.l2specific_len = 4;
463 		if (info->attrs[L2TP_ATTR_L2SPEC_LEN])
464 			cfg.l2specific_len = nla_get_u8(info->attrs[L2TP_ATTR_L2SPEC_LEN]);
465 
466 		if (info->attrs[L2TP_ATTR_COOKIE]) {
467 			u16 len = nla_len(info->attrs[L2TP_ATTR_COOKIE]);
468 			if (len > 8) {
469 				ret = -EINVAL;
470 				goto out;
471 			}
472 			cfg.cookie_len = len;
473 			memcpy(&cfg.cookie[0], nla_data(info->attrs[L2TP_ATTR_COOKIE]), len);
474 		}
475 		if (info->attrs[L2TP_ATTR_PEER_COOKIE]) {
476 			u16 len = nla_len(info->attrs[L2TP_ATTR_PEER_COOKIE]);
477 			if (len > 8) {
478 				ret = -EINVAL;
479 				goto out;
480 			}
481 			cfg.peer_cookie_len = len;
482 			memcpy(&cfg.peer_cookie[0], nla_data(info->attrs[L2TP_ATTR_PEER_COOKIE]), len);
483 		}
484 		if (info->attrs[L2TP_ATTR_IFNAME])
485 			cfg.ifname = nla_data(info->attrs[L2TP_ATTR_IFNAME]);
486 
487 		if (info->attrs[L2TP_ATTR_VLAN_ID])
488 			cfg.vlan_id = nla_get_u16(info->attrs[L2TP_ATTR_VLAN_ID]);
489 	}
490 
491 	if (info->attrs[L2TP_ATTR_DEBUG])
492 		cfg.debug = nla_get_u32(info->attrs[L2TP_ATTR_DEBUG]);
493 
494 	if (info->attrs[L2TP_ATTR_RECV_SEQ])
495 		cfg.recv_seq = nla_get_u8(info->attrs[L2TP_ATTR_RECV_SEQ]);
496 
497 	if (info->attrs[L2TP_ATTR_SEND_SEQ])
498 		cfg.send_seq = nla_get_u8(info->attrs[L2TP_ATTR_SEND_SEQ]);
499 
500 	if (info->attrs[L2TP_ATTR_LNS_MODE])
501 		cfg.lns_mode = nla_get_u8(info->attrs[L2TP_ATTR_LNS_MODE]);
502 
503 	if (info->attrs[L2TP_ATTR_RECV_TIMEOUT])
504 		cfg.reorder_timeout = nla_get_msecs(info->attrs[L2TP_ATTR_RECV_TIMEOUT]);
505 
506 	if (info->attrs[L2TP_ATTR_MTU])
507 		cfg.mtu = nla_get_u16(info->attrs[L2TP_ATTR_MTU]);
508 
509 	if (info->attrs[L2TP_ATTR_MRU])
510 		cfg.mru = nla_get_u16(info->attrs[L2TP_ATTR_MRU]);
511 
512 	if ((l2tp_nl_cmd_ops[cfg.pw_type] == NULL) ||
513 	    (l2tp_nl_cmd_ops[cfg.pw_type]->session_create == NULL)) {
514 		ret = -EPROTONOSUPPORT;
515 		goto out;
516 	}
517 
518 	/* Check that pseudowire-specific params are present */
519 	switch (cfg.pw_type) {
520 	case L2TP_PWTYPE_NONE:
521 		break;
522 	case L2TP_PWTYPE_ETH_VLAN:
523 		if (!info->attrs[L2TP_ATTR_VLAN_ID]) {
524 			ret = -EINVAL;
525 			goto out;
526 		}
527 		break;
528 	case L2TP_PWTYPE_ETH:
529 		break;
530 	case L2TP_PWTYPE_PPP:
531 	case L2TP_PWTYPE_PPP_AC:
532 		break;
533 	case L2TP_PWTYPE_IP:
534 	default:
535 		ret = -EPROTONOSUPPORT;
536 		break;
537 	}
538 
539 	ret = -EPROTONOSUPPORT;
540 	if (l2tp_nl_cmd_ops[cfg.pw_type]->session_create)
541 		ret = (*l2tp_nl_cmd_ops[cfg.pw_type]->session_create)(net, tunnel_id,
542 			session_id, peer_session_id, &cfg);
543 
544 out:
545 	return ret;
546 }
547 
548 static int l2tp_nl_cmd_session_delete(struct sk_buff *skb, struct genl_info *info)
549 {
550 	int ret = 0;
551 	struct l2tp_session *session;
552 	u16 pw_type;
553 
554 	session = l2tp_nl_session_find(info);
555 	if (session == NULL) {
556 		ret = -ENODEV;
557 		goto out;
558 	}
559 
560 	pw_type = session->pwtype;
561 	if (pw_type < __L2TP_PWTYPE_MAX)
562 		if (l2tp_nl_cmd_ops[pw_type] && l2tp_nl_cmd_ops[pw_type]->session_delete)
563 			ret = (*l2tp_nl_cmd_ops[pw_type]->session_delete)(session);
564 
565 out:
566 	return ret;
567 }
568 
569 static int l2tp_nl_cmd_session_modify(struct sk_buff *skb, struct genl_info *info)
570 {
571 	int ret = 0;
572 	struct l2tp_session *session;
573 
574 	session = l2tp_nl_session_find(info);
575 	if (session == NULL) {
576 		ret = -ENODEV;
577 		goto out;
578 	}
579 
580 	if (info->attrs[L2TP_ATTR_DEBUG])
581 		session->debug = nla_get_u32(info->attrs[L2TP_ATTR_DEBUG]);
582 
583 	if (info->attrs[L2TP_ATTR_DATA_SEQ])
584 		session->data_seq = nla_get_u8(info->attrs[L2TP_ATTR_DATA_SEQ]);
585 
586 	if (info->attrs[L2TP_ATTR_RECV_SEQ])
587 		session->recv_seq = nla_get_u8(info->attrs[L2TP_ATTR_RECV_SEQ]);
588 
589 	if (info->attrs[L2TP_ATTR_SEND_SEQ])
590 		session->send_seq = nla_get_u8(info->attrs[L2TP_ATTR_SEND_SEQ]);
591 
592 	if (info->attrs[L2TP_ATTR_LNS_MODE])
593 		session->lns_mode = nla_get_u8(info->attrs[L2TP_ATTR_LNS_MODE]);
594 
595 	if (info->attrs[L2TP_ATTR_RECV_TIMEOUT])
596 		session->reorder_timeout = nla_get_msecs(info->attrs[L2TP_ATTR_RECV_TIMEOUT]);
597 
598 	if (info->attrs[L2TP_ATTR_MTU])
599 		session->mtu = nla_get_u16(info->attrs[L2TP_ATTR_MTU]);
600 
601 	if (info->attrs[L2TP_ATTR_MRU])
602 		session->mru = nla_get_u16(info->attrs[L2TP_ATTR_MRU]);
603 
604 out:
605 	return ret;
606 }
607 
608 static int l2tp_nl_session_send(struct sk_buff *skb, u32 portid, u32 seq, int flags,
609 				struct l2tp_session *session)
610 {
611 	void *hdr;
612 	struct nlattr *nest;
613 	struct l2tp_tunnel *tunnel = session->tunnel;
614 	struct sock *sk = NULL;
615 	struct l2tp_stats stats;
616 	unsigned int start;
617 
618 	sk = tunnel->sock;
619 
620 	hdr = genlmsg_put(skb, portid, seq, &l2tp_nl_family, flags, L2TP_CMD_SESSION_GET);
621 	if (!hdr)
622 		return -EMSGSIZE;
623 
624 	if (nla_put_u32(skb, L2TP_ATTR_CONN_ID, tunnel->tunnel_id) ||
625 	    nla_put_u32(skb, L2TP_ATTR_SESSION_ID, session->session_id) ||
626 	    nla_put_u32(skb, L2TP_ATTR_PEER_CONN_ID, tunnel->peer_tunnel_id) ||
627 	    nla_put_u32(skb, L2TP_ATTR_PEER_SESSION_ID,
628 			session->peer_session_id) ||
629 	    nla_put_u32(skb, L2TP_ATTR_DEBUG, session->debug) ||
630 	    nla_put_u16(skb, L2TP_ATTR_PW_TYPE, session->pwtype) ||
631 	    nla_put_u16(skb, L2TP_ATTR_MTU, session->mtu) ||
632 	    (session->mru &&
633 	     nla_put_u16(skb, L2TP_ATTR_MRU, session->mru)))
634 		goto nla_put_failure;
635 
636 	if ((session->ifname[0] &&
637 	     nla_put_string(skb, L2TP_ATTR_IFNAME, session->ifname)) ||
638 	    (session->cookie_len &&
639 	     nla_put(skb, L2TP_ATTR_COOKIE, session->cookie_len,
640 		     &session->cookie[0])) ||
641 	    (session->peer_cookie_len &&
642 	     nla_put(skb, L2TP_ATTR_PEER_COOKIE, session->peer_cookie_len,
643 		     &session->peer_cookie[0])) ||
644 	    nla_put_u8(skb, L2TP_ATTR_RECV_SEQ, session->recv_seq) ||
645 	    nla_put_u8(skb, L2TP_ATTR_SEND_SEQ, session->send_seq) ||
646 	    nla_put_u8(skb, L2TP_ATTR_LNS_MODE, session->lns_mode) ||
647 #ifdef CONFIG_XFRM
648 	    (((sk) && (sk->sk_policy[0] || sk->sk_policy[1])) &&
649 	     nla_put_u8(skb, L2TP_ATTR_USING_IPSEC, 1)) ||
650 #endif
651 	    (session->reorder_timeout &&
652 	     nla_put_msecs(skb, L2TP_ATTR_RECV_TIMEOUT, session->reorder_timeout)))
653 		goto nla_put_failure;
654 
655 	nest = nla_nest_start(skb, L2TP_ATTR_STATS);
656 	if (nest == NULL)
657 		goto nla_put_failure;
658 
659 	do {
660 		start = u64_stats_fetch_begin(&session->stats.syncp);
661 		stats.tx_packets = session->stats.tx_packets;
662 		stats.tx_bytes = session->stats.tx_bytes;
663 		stats.tx_errors = session->stats.tx_errors;
664 		stats.rx_packets = session->stats.rx_packets;
665 		stats.rx_bytes = session->stats.rx_bytes;
666 		stats.rx_errors = session->stats.rx_errors;
667 		stats.rx_seq_discards = session->stats.rx_seq_discards;
668 		stats.rx_oos_packets = session->stats.rx_oos_packets;
669 	} while (u64_stats_fetch_retry(&session->stats.syncp, start));
670 
671 	if (nla_put_u64(skb, L2TP_ATTR_TX_PACKETS, stats.tx_packets) ||
672 	    nla_put_u64(skb, L2TP_ATTR_TX_BYTES, stats.tx_bytes) ||
673 	    nla_put_u64(skb, L2TP_ATTR_TX_ERRORS, stats.tx_errors) ||
674 	    nla_put_u64(skb, L2TP_ATTR_RX_PACKETS, stats.rx_packets) ||
675 	    nla_put_u64(skb, L2TP_ATTR_RX_BYTES, stats.rx_bytes) ||
676 	    nla_put_u64(skb, L2TP_ATTR_RX_SEQ_DISCARDS,
677 			stats.rx_seq_discards) ||
678 	    nla_put_u64(skb, L2TP_ATTR_RX_OOS_PACKETS,
679 			stats.rx_oos_packets) ||
680 	    nla_put_u64(skb, L2TP_ATTR_RX_ERRORS, stats.rx_errors))
681 		goto nla_put_failure;
682 	nla_nest_end(skb, nest);
683 
684 	return genlmsg_end(skb, hdr);
685 
686  nla_put_failure:
687 	genlmsg_cancel(skb, hdr);
688 	return -1;
689 }
690 
691 static int l2tp_nl_cmd_session_get(struct sk_buff *skb, struct genl_info *info)
692 {
693 	struct l2tp_session *session;
694 	struct sk_buff *msg;
695 	int ret;
696 
697 	session = l2tp_nl_session_find(info);
698 	if (session == NULL) {
699 		ret = -ENODEV;
700 		goto out;
701 	}
702 
703 	msg = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);
704 	if (!msg) {
705 		ret = -ENOMEM;
706 		goto out;
707 	}
708 
709 	ret = l2tp_nl_session_send(msg, info->snd_portid, info->snd_seq,
710 				   0, session);
711 	if (ret < 0)
712 		goto err_out;
713 
714 	return genlmsg_unicast(genl_info_net(info), msg, info->snd_portid);
715 
716 err_out:
717 	nlmsg_free(msg);
718 
719 out:
720 	return ret;
721 }
722 
723 static int l2tp_nl_cmd_session_dump(struct sk_buff *skb, struct netlink_callback *cb)
724 {
725 	struct net *net = sock_net(skb->sk);
726 	struct l2tp_session *session;
727 	struct l2tp_tunnel *tunnel = NULL;
728 	int ti = cb->args[0];
729 	int si = cb->args[1];
730 
731 	for (;;) {
732 		if (tunnel == NULL) {
733 			tunnel = l2tp_tunnel_find_nth(net, ti);
734 			if (tunnel == NULL)
735 				goto out;
736 		}
737 
738 		session = l2tp_session_find_nth(tunnel, si);
739 		if (session == NULL) {
740 			ti++;
741 			tunnel = NULL;
742 			si = 0;
743 			continue;
744 		}
745 
746 		if (l2tp_nl_session_send(skb, NETLINK_CB(cb->skb).portid,
747 					 cb->nlh->nlmsg_seq, NLM_F_MULTI,
748 					 session) <= 0)
749 			break;
750 
751 		si++;
752 	}
753 
754 out:
755 	cb->args[0] = ti;
756 	cb->args[1] = si;
757 
758 	return skb->len;
759 }
760 
761 static struct nla_policy l2tp_nl_policy[L2TP_ATTR_MAX + 1] = {
762 	[L2TP_ATTR_NONE]		= { .type = NLA_UNSPEC, },
763 	[L2TP_ATTR_PW_TYPE]		= { .type = NLA_U16, },
764 	[L2TP_ATTR_ENCAP_TYPE]		= { .type = NLA_U16, },
765 	[L2TP_ATTR_OFFSET]		= { .type = NLA_U16, },
766 	[L2TP_ATTR_DATA_SEQ]		= { .type = NLA_U8, },
767 	[L2TP_ATTR_L2SPEC_TYPE]		= { .type = NLA_U8, },
768 	[L2TP_ATTR_L2SPEC_LEN]		= { .type = NLA_U8, },
769 	[L2TP_ATTR_PROTO_VERSION]	= { .type = NLA_U8, },
770 	[L2TP_ATTR_CONN_ID]		= { .type = NLA_U32, },
771 	[L2TP_ATTR_PEER_CONN_ID]	= { .type = NLA_U32, },
772 	[L2TP_ATTR_SESSION_ID]		= { .type = NLA_U32, },
773 	[L2TP_ATTR_PEER_SESSION_ID]	= { .type = NLA_U32, },
774 	[L2TP_ATTR_UDP_CSUM]		= { .type = NLA_U8, },
775 	[L2TP_ATTR_VLAN_ID]		= { .type = NLA_U16, },
776 	[L2TP_ATTR_DEBUG]		= { .type = NLA_U32, },
777 	[L2TP_ATTR_RECV_SEQ]		= { .type = NLA_U8, },
778 	[L2TP_ATTR_SEND_SEQ]		= { .type = NLA_U8, },
779 	[L2TP_ATTR_LNS_MODE]		= { .type = NLA_U8, },
780 	[L2TP_ATTR_USING_IPSEC]		= { .type = NLA_U8, },
781 	[L2TP_ATTR_RECV_TIMEOUT]	= { .type = NLA_MSECS, },
782 	[L2TP_ATTR_FD]			= { .type = NLA_U32, },
783 	[L2TP_ATTR_IP_SADDR]		= { .type = NLA_U32, },
784 	[L2TP_ATTR_IP_DADDR]		= { .type = NLA_U32, },
785 	[L2TP_ATTR_UDP_SPORT]		= { .type = NLA_U16, },
786 	[L2TP_ATTR_UDP_DPORT]		= { .type = NLA_U16, },
787 	[L2TP_ATTR_MTU]			= { .type = NLA_U16, },
788 	[L2TP_ATTR_MRU]			= { .type = NLA_U16, },
789 	[L2TP_ATTR_STATS]		= { .type = NLA_NESTED, },
790 	[L2TP_ATTR_IP6_SADDR] = {
791 		.type = NLA_BINARY,
792 		.len = sizeof(struct in6_addr),
793 	},
794 	[L2TP_ATTR_IP6_DADDR] = {
795 		.type = NLA_BINARY,
796 		.len = sizeof(struct in6_addr),
797 	},
798 	[L2TP_ATTR_IFNAME] = {
799 		.type = NLA_NUL_STRING,
800 		.len = IFNAMSIZ - 1,
801 	},
802 	[L2TP_ATTR_COOKIE] = {
803 		.type = NLA_BINARY,
804 		.len = 8,
805 	},
806 	[L2TP_ATTR_PEER_COOKIE] = {
807 		.type = NLA_BINARY,
808 		.len = 8,
809 	},
810 };
811 
812 static struct genl_ops l2tp_nl_ops[] = {
813 	{
814 		.cmd = L2TP_CMD_NOOP,
815 		.doit = l2tp_nl_cmd_noop,
816 		.policy = l2tp_nl_policy,
817 		/* can be retrieved by unprivileged users */
818 	},
819 	{
820 		.cmd = L2TP_CMD_TUNNEL_CREATE,
821 		.doit = l2tp_nl_cmd_tunnel_create,
822 		.policy = l2tp_nl_policy,
823 		.flags = GENL_ADMIN_PERM,
824 	},
825 	{
826 		.cmd = L2TP_CMD_TUNNEL_DELETE,
827 		.doit = l2tp_nl_cmd_tunnel_delete,
828 		.policy = l2tp_nl_policy,
829 		.flags = GENL_ADMIN_PERM,
830 	},
831 	{
832 		.cmd = L2TP_CMD_TUNNEL_MODIFY,
833 		.doit = l2tp_nl_cmd_tunnel_modify,
834 		.policy = l2tp_nl_policy,
835 		.flags = GENL_ADMIN_PERM,
836 	},
837 	{
838 		.cmd = L2TP_CMD_TUNNEL_GET,
839 		.doit = l2tp_nl_cmd_tunnel_get,
840 		.dumpit = l2tp_nl_cmd_tunnel_dump,
841 		.policy = l2tp_nl_policy,
842 		.flags = GENL_ADMIN_PERM,
843 	},
844 	{
845 		.cmd = L2TP_CMD_SESSION_CREATE,
846 		.doit = l2tp_nl_cmd_session_create,
847 		.policy = l2tp_nl_policy,
848 		.flags = GENL_ADMIN_PERM,
849 	},
850 	{
851 		.cmd = L2TP_CMD_SESSION_DELETE,
852 		.doit = l2tp_nl_cmd_session_delete,
853 		.policy = l2tp_nl_policy,
854 		.flags = GENL_ADMIN_PERM,
855 	},
856 	{
857 		.cmd = L2TP_CMD_SESSION_MODIFY,
858 		.doit = l2tp_nl_cmd_session_modify,
859 		.policy = l2tp_nl_policy,
860 		.flags = GENL_ADMIN_PERM,
861 	},
862 	{
863 		.cmd = L2TP_CMD_SESSION_GET,
864 		.doit = l2tp_nl_cmd_session_get,
865 		.dumpit = l2tp_nl_cmd_session_dump,
866 		.policy = l2tp_nl_policy,
867 		.flags = GENL_ADMIN_PERM,
868 	},
869 };
870 
871 int l2tp_nl_register_ops(enum l2tp_pwtype pw_type, const struct l2tp_nl_cmd_ops *ops)
872 {
873 	int ret;
874 
875 	ret = -EINVAL;
876 	if (pw_type >= __L2TP_PWTYPE_MAX)
877 		goto err;
878 
879 	genl_lock();
880 	ret = -EBUSY;
881 	if (l2tp_nl_cmd_ops[pw_type])
882 		goto out;
883 
884 	l2tp_nl_cmd_ops[pw_type] = ops;
885 	ret = 0;
886 
887 out:
888 	genl_unlock();
889 err:
890 	return ret;
891 }
892 EXPORT_SYMBOL_GPL(l2tp_nl_register_ops);
893 
894 void l2tp_nl_unregister_ops(enum l2tp_pwtype pw_type)
895 {
896 	if (pw_type < __L2TP_PWTYPE_MAX) {
897 		genl_lock();
898 		l2tp_nl_cmd_ops[pw_type] = NULL;
899 		genl_unlock();
900 	}
901 }
902 EXPORT_SYMBOL_GPL(l2tp_nl_unregister_ops);
903 
904 static int l2tp_nl_init(void)
905 {
906 	int err;
907 
908 	pr_info("L2TP netlink interface\n");
909 	err = genl_register_family_with_ops(&l2tp_nl_family, l2tp_nl_ops,
910 					    ARRAY_SIZE(l2tp_nl_ops));
911 
912 	return err;
913 }
914 
915 static void l2tp_nl_cleanup(void)
916 {
917 	genl_unregister_family(&l2tp_nl_family);
918 }
919 
920 module_init(l2tp_nl_init);
921 module_exit(l2tp_nl_cleanup);
922 
923 MODULE_AUTHOR("James Chapman <jchapman@katalix.com>");
924 MODULE_DESCRIPTION("L2TP netlink");
925 MODULE_LICENSE("GPL");
926 MODULE_VERSION("1.0");
927 MODULE_ALIAS_GENL_FAMILY("l2tp");
928