xref: /openbmc/linux/net/l2tp/l2tp_netlink.c (revision 95e9fd10)
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 };
41 
42 /* Accessed under genl lock */
43 static const struct l2tp_nl_cmd_ops *l2tp_nl_cmd_ops[__L2TP_PWTYPE_MAX];
44 
45 static struct l2tp_session *l2tp_nl_session_find(struct genl_info *info)
46 {
47 	u32 tunnel_id;
48 	u32 session_id;
49 	char *ifname;
50 	struct l2tp_tunnel *tunnel;
51 	struct l2tp_session *session = NULL;
52 	struct net *net = genl_info_net(info);
53 
54 	if (info->attrs[L2TP_ATTR_IFNAME]) {
55 		ifname = nla_data(info->attrs[L2TP_ATTR_IFNAME]);
56 		session = l2tp_session_find_by_ifname(net, ifname);
57 	} else if ((info->attrs[L2TP_ATTR_SESSION_ID]) &&
58 		   (info->attrs[L2TP_ATTR_CONN_ID])) {
59 		tunnel_id = nla_get_u32(info->attrs[L2TP_ATTR_CONN_ID]);
60 		session_id = nla_get_u32(info->attrs[L2TP_ATTR_SESSION_ID]);
61 		tunnel = l2tp_tunnel_find(net, tunnel_id);
62 		if (tunnel)
63 			session = l2tp_session_find(net, tunnel, session_id);
64 	}
65 
66 	return session;
67 }
68 
69 static int l2tp_nl_cmd_noop(struct sk_buff *skb, struct genl_info *info)
70 {
71 	struct sk_buff *msg;
72 	void *hdr;
73 	int ret = -ENOBUFS;
74 
75 	msg = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);
76 	if (!msg) {
77 		ret = -ENOMEM;
78 		goto out;
79 	}
80 
81 	hdr = genlmsg_put(msg, info->snd_pid, info->snd_seq,
82 			  &l2tp_nl_family, 0, L2TP_CMD_NOOP);
83 	if (IS_ERR(hdr)) {
84 		ret = PTR_ERR(hdr);
85 		goto err_out;
86 	}
87 
88 	genlmsg_end(msg, hdr);
89 
90 	return genlmsg_unicast(genl_info_net(info), msg, info->snd_pid);
91 
92 err_out:
93 	nlmsg_free(msg);
94 
95 out:
96 	return ret;
97 }
98 
99 static int l2tp_nl_cmd_tunnel_create(struct sk_buff *skb, struct genl_info *info)
100 {
101 	u32 tunnel_id;
102 	u32 peer_tunnel_id;
103 	int proto_version;
104 	int fd;
105 	int ret = 0;
106 	struct l2tp_tunnel_cfg cfg = { 0, };
107 	struct l2tp_tunnel *tunnel;
108 	struct net *net = genl_info_net(info);
109 
110 	if (!info->attrs[L2TP_ATTR_CONN_ID]) {
111 		ret = -EINVAL;
112 		goto out;
113 	}
114 	tunnel_id = nla_get_u32(info->attrs[L2TP_ATTR_CONN_ID]);
115 
116 	if (!info->attrs[L2TP_ATTR_PEER_CONN_ID]) {
117 		ret = -EINVAL;
118 		goto out;
119 	}
120 	peer_tunnel_id = nla_get_u32(info->attrs[L2TP_ATTR_PEER_CONN_ID]);
121 
122 	if (!info->attrs[L2TP_ATTR_PROTO_VERSION]) {
123 		ret = -EINVAL;
124 		goto out;
125 	}
126 	proto_version = nla_get_u8(info->attrs[L2TP_ATTR_PROTO_VERSION]);
127 
128 	if (!info->attrs[L2TP_ATTR_ENCAP_TYPE]) {
129 		ret = -EINVAL;
130 		goto out;
131 	}
132 	cfg.encap = nla_get_u16(info->attrs[L2TP_ATTR_ENCAP_TYPE]);
133 
134 	fd = -1;
135 	if (info->attrs[L2TP_ATTR_FD]) {
136 		fd = nla_get_u32(info->attrs[L2TP_ATTR_FD]);
137 	} else {
138 #if IS_ENABLED(CONFIG_IPV6)
139 		if (info->attrs[L2TP_ATTR_IP6_SADDR] &&
140 		    info->attrs[L2TP_ATTR_IP6_DADDR]) {
141 			cfg.local_ip6 = nla_data(
142 				info->attrs[L2TP_ATTR_IP6_SADDR]);
143 			cfg.peer_ip6 = nla_data(
144 				info->attrs[L2TP_ATTR_IP6_DADDR]);
145 		} else
146 #endif
147 		if (info->attrs[L2TP_ATTR_IP_SADDR] &&
148 		    info->attrs[L2TP_ATTR_IP_DADDR]) {
149 			cfg.local_ip.s_addr = nla_get_be32(
150 				info->attrs[L2TP_ATTR_IP_SADDR]);
151 			cfg.peer_ip.s_addr = nla_get_be32(
152 				info->attrs[L2TP_ATTR_IP_DADDR]);
153 		} else {
154 			ret = -EINVAL;
155 			goto out;
156 		}
157 		if (info->attrs[L2TP_ATTR_UDP_SPORT])
158 			cfg.local_udp_port = nla_get_u16(info->attrs[L2TP_ATTR_UDP_SPORT]);
159 		if (info->attrs[L2TP_ATTR_UDP_DPORT])
160 			cfg.peer_udp_port = nla_get_u16(info->attrs[L2TP_ATTR_UDP_DPORT]);
161 		if (info->attrs[L2TP_ATTR_UDP_CSUM])
162 			cfg.use_udp_checksums = nla_get_flag(info->attrs[L2TP_ATTR_UDP_CSUM]);
163 	}
164 
165 	if (info->attrs[L2TP_ATTR_DEBUG])
166 		cfg.debug = nla_get_u32(info->attrs[L2TP_ATTR_DEBUG]);
167 
168 	tunnel = l2tp_tunnel_find(net, tunnel_id);
169 	if (tunnel != NULL) {
170 		ret = -EEXIST;
171 		goto out;
172 	}
173 
174 	ret = -EINVAL;
175 	switch (cfg.encap) {
176 	case L2TP_ENCAPTYPE_UDP:
177 	case L2TP_ENCAPTYPE_IP:
178 		ret = l2tp_tunnel_create(net, fd, proto_version, tunnel_id,
179 					 peer_tunnel_id, &cfg, &tunnel);
180 		break;
181 	}
182 
183 out:
184 	return ret;
185 }
186 
187 static int l2tp_nl_cmd_tunnel_delete(struct sk_buff *skb, struct genl_info *info)
188 {
189 	struct l2tp_tunnel *tunnel;
190 	u32 tunnel_id;
191 	int ret = 0;
192 	struct net *net = genl_info_net(info);
193 
194 	if (!info->attrs[L2TP_ATTR_CONN_ID]) {
195 		ret = -EINVAL;
196 		goto out;
197 	}
198 	tunnel_id = nla_get_u32(info->attrs[L2TP_ATTR_CONN_ID]);
199 
200 	tunnel = l2tp_tunnel_find(net, tunnel_id);
201 	if (tunnel == NULL) {
202 		ret = -ENODEV;
203 		goto out;
204 	}
205 
206 	(void) l2tp_tunnel_delete(tunnel);
207 
208 out:
209 	return ret;
210 }
211 
212 static int l2tp_nl_cmd_tunnel_modify(struct sk_buff *skb, struct genl_info *info)
213 {
214 	struct l2tp_tunnel *tunnel;
215 	u32 tunnel_id;
216 	int ret = 0;
217 	struct net *net = genl_info_net(info);
218 
219 	if (!info->attrs[L2TP_ATTR_CONN_ID]) {
220 		ret = -EINVAL;
221 		goto out;
222 	}
223 	tunnel_id = nla_get_u32(info->attrs[L2TP_ATTR_CONN_ID]);
224 
225 	tunnel = l2tp_tunnel_find(net, tunnel_id);
226 	if (tunnel == NULL) {
227 		ret = -ENODEV;
228 		goto out;
229 	}
230 
231 	if (info->attrs[L2TP_ATTR_DEBUG])
232 		tunnel->debug = nla_get_u32(info->attrs[L2TP_ATTR_DEBUG]);
233 
234 out:
235 	return ret;
236 }
237 
238 static int l2tp_nl_tunnel_send(struct sk_buff *skb, u32 pid, u32 seq, int flags,
239 			       struct l2tp_tunnel *tunnel)
240 {
241 	void *hdr;
242 	struct nlattr *nest;
243 	struct sock *sk = NULL;
244 	struct inet_sock *inet;
245 #if IS_ENABLED(CONFIG_IPV6)
246 	struct ipv6_pinfo *np = NULL;
247 #endif
248 	struct l2tp_stats stats;
249 	unsigned int start;
250 
251 	hdr = genlmsg_put(skb, pid, seq, &l2tp_nl_family, flags,
252 			  L2TP_CMD_TUNNEL_GET);
253 	if (IS_ERR(hdr))
254 		return PTR_ERR(hdr);
255 
256 	if (nla_put_u8(skb, L2TP_ATTR_PROTO_VERSION, tunnel->version) ||
257 	    nla_put_u32(skb, L2TP_ATTR_CONN_ID, tunnel->tunnel_id) ||
258 	    nla_put_u32(skb, L2TP_ATTR_PEER_CONN_ID, tunnel->peer_tunnel_id) ||
259 	    nla_put_u32(skb, L2TP_ATTR_DEBUG, tunnel->debug) ||
260 	    nla_put_u16(skb, L2TP_ATTR_ENCAP_TYPE, tunnel->encap))
261 		goto nla_put_failure;
262 
263 	nest = nla_nest_start(skb, L2TP_ATTR_STATS);
264 	if (nest == NULL)
265 		goto nla_put_failure;
266 
267 	do {
268 		start = u64_stats_fetch_begin(&tunnel->stats.syncp);
269 		stats.tx_packets = tunnel->stats.tx_packets;
270 		stats.tx_bytes = tunnel->stats.tx_bytes;
271 		stats.tx_errors = tunnel->stats.tx_errors;
272 		stats.rx_packets = tunnel->stats.rx_packets;
273 		stats.rx_bytes = tunnel->stats.rx_bytes;
274 		stats.rx_errors = tunnel->stats.rx_errors;
275 		stats.rx_seq_discards = tunnel->stats.rx_seq_discards;
276 		stats.rx_oos_packets = tunnel->stats.rx_oos_packets;
277 	} while (u64_stats_fetch_retry(&tunnel->stats.syncp, start));
278 
279 	if (nla_put_u64(skb, L2TP_ATTR_TX_PACKETS, stats.tx_packets) ||
280 	    nla_put_u64(skb, L2TP_ATTR_TX_BYTES, stats.tx_bytes) ||
281 	    nla_put_u64(skb, L2TP_ATTR_TX_ERRORS, stats.tx_errors) ||
282 	    nla_put_u64(skb, L2TP_ATTR_RX_PACKETS, stats.rx_packets) ||
283 	    nla_put_u64(skb, L2TP_ATTR_RX_BYTES, stats.rx_bytes) ||
284 	    nla_put_u64(skb, L2TP_ATTR_RX_SEQ_DISCARDS,
285 			stats.rx_seq_discards) ||
286 	    nla_put_u64(skb, L2TP_ATTR_RX_OOS_PACKETS,
287 			stats.rx_oos_packets) ||
288 	    nla_put_u64(skb, L2TP_ATTR_RX_ERRORS, stats.rx_errors))
289 		goto nla_put_failure;
290 	nla_nest_end(skb, nest);
291 
292 	sk = tunnel->sock;
293 	if (!sk)
294 		goto out;
295 
296 #if IS_ENABLED(CONFIG_IPV6)
297 	if (sk->sk_family == AF_INET6)
298 		np = inet6_sk(sk);
299 #endif
300 
301 	inet = inet_sk(sk);
302 
303 	switch (tunnel->encap) {
304 	case L2TP_ENCAPTYPE_UDP:
305 		if (nla_put_u16(skb, L2TP_ATTR_UDP_SPORT, ntohs(inet->inet_sport)) ||
306 		    nla_put_u16(skb, L2TP_ATTR_UDP_DPORT, ntohs(inet->inet_dport)) ||
307 		    nla_put_u8(skb, L2TP_ATTR_UDP_CSUM,
308 			       (sk->sk_no_check != UDP_CSUM_NOXMIT)))
309 			goto nla_put_failure;
310 		/* NOBREAK */
311 	case L2TP_ENCAPTYPE_IP:
312 #if IS_ENABLED(CONFIG_IPV6)
313 		if (np) {
314 			if (nla_put(skb, L2TP_ATTR_IP6_SADDR, sizeof(np->saddr),
315 				    &np->saddr) ||
316 			    nla_put(skb, L2TP_ATTR_IP6_DADDR, sizeof(np->daddr),
317 				    &np->daddr))
318 				goto nla_put_failure;
319 		} else
320 #endif
321 		if (nla_put_be32(skb, L2TP_ATTR_IP_SADDR, inet->inet_saddr) ||
322 		    nla_put_be32(skb, L2TP_ATTR_IP_DADDR, inet->inet_daddr))
323 			goto nla_put_failure;
324 		break;
325 	}
326 
327 out:
328 	return genlmsg_end(skb, hdr);
329 
330 nla_put_failure:
331 	genlmsg_cancel(skb, hdr);
332 	return -1;
333 }
334 
335 static int l2tp_nl_cmd_tunnel_get(struct sk_buff *skb, struct genl_info *info)
336 {
337 	struct l2tp_tunnel *tunnel;
338 	struct sk_buff *msg;
339 	u32 tunnel_id;
340 	int ret = -ENOBUFS;
341 	struct net *net = genl_info_net(info);
342 
343 	if (!info->attrs[L2TP_ATTR_CONN_ID]) {
344 		ret = -EINVAL;
345 		goto out;
346 	}
347 
348 	tunnel_id = nla_get_u32(info->attrs[L2TP_ATTR_CONN_ID]);
349 
350 	tunnel = l2tp_tunnel_find(net, tunnel_id);
351 	if (tunnel == NULL) {
352 		ret = -ENODEV;
353 		goto out;
354 	}
355 
356 	msg = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);
357 	if (!msg) {
358 		ret = -ENOMEM;
359 		goto out;
360 	}
361 
362 	ret = l2tp_nl_tunnel_send(msg, info->snd_pid, info->snd_seq,
363 				  NLM_F_ACK, tunnel);
364 	if (ret < 0)
365 		goto err_out;
366 
367 	return genlmsg_unicast(net, msg, info->snd_pid);
368 
369 err_out:
370 	nlmsg_free(msg);
371 
372 out:
373 	return ret;
374 }
375 
376 static int l2tp_nl_cmd_tunnel_dump(struct sk_buff *skb, struct netlink_callback *cb)
377 {
378 	int ti = cb->args[0];
379 	struct l2tp_tunnel *tunnel;
380 	struct net *net = sock_net(skb->sk);
381 
382 	for (;;) {
383 		tunnel = l2tp_tunnel_find_nth(net, ti);
384 		if (tunnel == NULL)
385 			goto out;
386 
387 		if (l2tp_nl_tunnel_send(skb, NETLINK_CB(cb->skb).pid,
388 					cb->nlh->nlmsg_seq, NLM_F_MULTI,
389 					tunnel) <= 0)
390 			goto out;
391 
392 		ti++;
393 	}
394 
395 out:
396 	cb->args[0] = ti;
397 
398 	return skb->len;
399 }
400 
401 static int l2tp_nl_cmd_session_create(struct sk_buff *skb, struct genl_info *info)
402 {
403 	u32 tunnel_id = 0;
404 	u32 session_id;
405 	u32 peer_session_id;
406 	int ret = 0;
407 	struct l2tp_tunnel *tunnel;
408 	struct l2tp_session *session;
409 	struct l2tp_session_cfg cfg = { 0, };
410 	struct net *net = genl_info_net(info);
411 
412 	if (!info->attrs[L2TP_ATTR_CONN_ID]) {
413 		ret = -EINVAL;
414 		goto out;
415 	}
416 	tunnel_id = nla_get_u32(info->attrs[L2TP_ATTR_CONN_ID]);
417 	tunnel = l2tp_tunnel_find(net, tunnel_id);
418 	if (!tunnel) {
419 		ret = -ENODEV;
420 		goto out;
421 	}
422 
423 	if (!info->attrs[L2TP_ATTR_SESSION_ID]) {
424 		ret = -EINVAL;
425 		goto out;
426 	}
427 	session_id = nla_get_u32(info->attrs[L2TP_ATTR_SESSION_ID]);
428 	session = l2tp_session_find(net, tunnel, session_id);
429 	if (session) {
430 		ret = -EEXIST;
431 		goto out;
432 	}
433 
434 	if (!info->attrs[L2TP_ATTR_PEER_SESSION_ID]) {
435 		ret = -EINVAL;
436 		goto out;
437 	}
438 	peer_session_id = nla_get_u32(info->attrs[L2TP_ATTR_PEER_SESSION_ID]);
439 
440 	if (!info->attrs[L2TP_ATTR_PW_TYPE]) {
441 		ret = -EINVAL;
442 		goto out;
443 	}
444 	cfg.pw_type = nla_get_u16(info->attrs[L2TP_ATTR_PW_TYPE]);
445 	if (cfg.pw_type >= __L2TP_PWTYPE_MAX) {
446 		ret = -EINVAL;
447 		goto out;
448 	}
449 
450 	if (tunnel->version > 2) {
451 		if (info->attrs[L2TP_ATTR_OFFSET])
452 			cfg.offset = nla_get_u16(info->attrs[L2TP_ATTR_OFFSET]);
453 
454 		if (info->attrs[L2TP_ATTR_DATA_SEQ])
455 			cfg.data_seq = nla_get_u8(info->attrs[L2TP_ATTR_DATA_SEQ]);
456 
457 		cfg.l2specific_type = L2TP_L2SPECTYPE_DEFAULT;
458 		if (info->attrs[L2TP_ATTR_L2SPEC_TYPE])
459 			cfg.l2specific_type = nla_get_u8(info->attrs[L2TP_ATTR_L2SPEC_TYPE]);
460 
461 		cfg.l2specific_len = 4;
462 		if (info->attrs[L2TP_ATTR_L2SPEC_LEN])
463 			cfg.l2specific_len = nla_get_u8(info->attrs[L2TP_ATTR_L2SPEC_LEN]);
464 
465 		if (info->attrs[L2TP_ATTR_COOKIE]) {
466 			u16 len = nla_len(info->attrs[L2TP_ATTR_COOKIE]);
467 			if (len > 8) {
468 				ret = -EINVAL;
469 				goto out;
470 			}
471 			cfg.cookie_len = len;
472 			memcpy(&cfg.cookie[0], nla_data(info->attrs[L2TP_ATTR_COOKIE]), len);
473 		}
474 		if (info->attrs[L2TP_ATTR_PEER_COOKIE]) {
475 			u16 len = nla_len(info->attrs[L2TP_ATTR_PEER_COOKIE]);
476 			if (len > 8) {
477 				ret = -EINVAL;
478 				goto out;
479 			}
480 			cfg.peer_cookie_len = len;
481 			memcpy(&cfg.peer_cookie[0], nla_data(info->attrs[L2TP_ATTR_PEER_COOKIE]), len);
482 		}
483 		if (info->attrs[L2TP_ATTR_IFNAME])
484 			cfg.ifname = nla_data(info->attrs[L2TP_ATTR_IFNAME]);
485 
486 		if (info->attrs[L2TP_ATTR_VLAN_ID])
487 			cfg.vlan_id = nla_get_u16(info->attrs[L2TP_ATTR_VLAN_ID]);
488 	}
489 
490 	if (info->attrs[L2TP_ATTR_DEBUG])
491 		cfg.debug = nla_get_u32(info->attrs[L2TP_ATTR_DEBUG]);
492 
493 	if (info->attrs[L2TP_ATTR_RECV_SEQ])
494 		cfg.recv_seq = nla_get_u8(info->attrs[L2TP_ATTR_RECV_SEQ]);
495 
496 	if (info->attrs[L2TP_ATTR_SEND_SEQ])
497 		cfg.send_seq = nla_get_u8(info->attrs[L2TP_ATTR_SEND_SEQ]);
498 
499 	if (info->attrs[L2TP_ATTR_LNS_MODE])
500 		cfg.lns_mode = nla_get_u8(info->attrs[L2TP_ATTR_LNS_MODE]);
501 
502 	if (info->attrs[L2TP_ATTR_RECV_TIMEOUT])
503 		cfg.reorder_timeout = nla_get_msecs(info->attrs[L2TP_ATTR_RECV_TIMEOUT]);
504 
505 	if (info->attrs[L2TP_ATTR_MTU])
506 		cfg.mtu = nla_get_u16(info->attrs[L2TP_ATTR_MTU]);
507 
508 	if (info->attrs[L2TP_ATTR_MRU])
509 		cfg.mru = nla_get_u16(info->attrs[L2TP_ATTR_MRU]);
510 
511 	if ((l2tp_nl_cmd_ops[cfg.pw_type] == NULL) ||
512 	    (l2tp_nl_cmd_ops[cfg.pw_type]->session_create == NULL)) {
513 		ret = -EPROTONOSUPPORT;
514 		goto out;
515 	}
516 
517 	/* Check that pseudowire-specific params are present */
518 	switch (cfg.pw_type) {
519 	case L2TP_PWTYPE_NONE:
520 		break;
521 	case L2TP_PWTYPE_ETH_VLAN:
522 		if (!info->attrs[L2TP_ATTR_VLAN_ID]) {
523 			ret = -EINVAL;
524 			goto out;
525 		}
526 		break;
527 	case L2TP_PWTYPE_ETH:
528 		break;
529 	case L2TP_PWTYPE_PPP:
530 	case L2TP_PWTYPE_PPP_AC:
531 		break;
532 	case L2TP_PWTYPE_IP:
533 	default:
534 		ret = -EPROTONOSUPPORT;
535 		break;
536 	}
537 
538 	ret = -EPROTONOSUPPORT;
539 	if (l2tp_nl_cmd_ops[cfg.pw_type]->session_create)
540 		ret = (*l2tp_nl_cmd_ops[cfg.pw_type]->session_create)(net, tunnel_id,
541 			session_id, peer_session_id, &cfg);
542 
543 out:
544 	return ret;
545 }
546 
547 static int l2tp_nl_cmd_session_delete(struct sk_buff *skb, struct genl_info *info)
548 {
549 	int ret = 0;
550 	struct l2tp_session *session;
551 	u16 pw_type;
552 
553 	session = l2tp_nl_session_find(info);
554 	if (session == NULL) {
555 		ret = -ENODEV;
556 		goto out;
557 	}
558 
559 	pw_type = session->pwtype;
560 	if (pw_type < __L2TP_PWTYPE_MAX)
561 		if (l2tp_nl_cmd_ops[pw_type] && l2tp_nl_cmd_ops[pw_type]->session_delete)
562 			ret = (*l2tp_nl_cmd_ops[pw_type]->session_delete)(session);
563 
564 out:
565 	return ret;
566 }
567 
568 static int l2tp_nl_cmd_session_modify(struct sk_buff *skb, struct genl_info *info)
569 {
570 	int ret = 0;
571 	struct l2tp_session *session;
572 
573 	session = l2tp_nl_session_find(info);
574 	if (session == NULL) {
575 		ret = -ENODEV;
576 		goto out;
577 	}
578 
579 	if (info->attrs[L2TP_ATTR_DEBUG])
580 		session->debug = nla_get_u32(info->attrs[L2TP_ATTR_DEBUG]);
581 
582 	if (info->attrs[L2TP_ATTR_DATA_SEQ])
583 		session->data_seq = nla_get_u8(info->attrs[L2TP_ATTR_DATA_SEQ]);
584 
585 	if (info->attrs[L2TP_ATTR_RECV_SEQ])
586 		session->recv_seq = nla_get_u8(info->attrs[L2TP_ATTR_RECV_SEQ]);
587 
588 	if (info->attrs[L2TP_ATTR_SEND_SEQ])
589 		session->send_seq = nla_get_u8(info->attrs[L2TP_ATTR_SEND_SEQ]);
590 
591 	if (info->attrs[L2TP_ATTR_LNS_MODE])
592 		session->lns_mode = nla_get_u8(info->attrs[L2TP_ATTR_LNS_MODE]);
593 
594 	if (info->attrs[L2TP_ATTR_RECV_TIMEOUT])
595 		session->reorder_timeout = nla_get_msecs(info->attrs[L2TP_ATTR_RECV_TIMEOUT]);
596 
597 	if (info->attrs[L2TP_ATTR_MTU])
598 		session->mtu = nla_get_u16(info->attrs[L2TP_ATTR_MTU]);
599 
600 	if (info->attrs[L2TP_ATTR_MRU])
601 		session->mru = nla_get_u16(info->attrs[L2TP_ATTR_MRU]);
602 
603 out:
604 	return ret;
605 }
606 
607 static int l2tp_nl_session_send(struct sk_buff *skb, u32 pid, u32 seq, int flags,
608 				struct l2tp_session *session)
609 {
610 	void *hdr;
611 	struct nlattr *nest;
612 	struct l2tp_tunnel *tunnel = session->tunnel;
613 	struct sock *sk = NULL;
614 	struct l2tp_stats stats;
615 	unsigned int start;
616 
617 	sk = tunnel->sock;
618 
619 	hdr = genlmsg_put(skb, pid, seq, &l2tp_nl_family, flags, L2TP_CMD_SESSION_GET);
620 	if (IS_ERR(hdr))
621 		return PTR_ERR(hdr);
622 
623 	if (nla_put_u32(skb, L2TP_ATTR_CONN_ID, tunnel->tunnel_id) ||
624 	    nla_put_u32(skb, L2TP_ATTR_SESSION_ID, session->session_id) ||
625 	    nla_put_u32(skb, L2TP_ATTR_PEER_CONN_ID, tunnel->peer_tunnel_id) ||
626 	    nla_put_u32(skb, L2TP_ATTR_PEER_SESSION_ID,
627 			session->peer_session_id) ||
628 	    nla_put_u32(skb, L2TP_ATTR_DEBUG, session->debug) ||
629 	    nla_put_u16(skb, L2TP_ATTR_PW_TYPE, session->pwtype) ||
630 	    nla_put_u16(skb, L2TP_ATTR_MTU, session->mtu) ||
631 	    (session->mru &&
632 	     nla_put_u16(skb, L2TP_ATTR_MRU, session->mru)))
633 		goto nla_put_failure;
634 
635 	if ((session->ifname && session->ifname[0] &&
636 	     nla_put_string(skb, L2TP_ATTR_IFNAME, session->ifname)) ||
637 	    (session->cookie_len &&
638 	     nla_put(skb, L2TP_ATTR_COOKIE, session->cookie_len,
639 		     &session->cookie[0])) ||
640 	    (session->peer_cookie_len &&
641 	     nla_put(skb, L2TP_ATTR_PEER_COOKIE, session->peer_cookie_len,
642 		     &session->peer_cookie[0])) ||
643 	    nla_put_u8(skb, L2TP_ATTR_RECV_SEQ, session->recv_seq) ||
644 	    nla_put_u8(skb, L2TP_ATTR_SEND_SEQ, session->send_seq) ||
645 	    nla_put_u8(skb, L2TP_ATTR_LNS_MODE, session->lns_mode) ||
646 #ifdef CONFIG_XFRM
647 	    (((sk) && (sk->sk_policy[0] || sk->sk_policy[1])) &&
648 	     nla_put_u8(skb, L2TP_ATTR_USING_IPSEC, 1)) ||
649 #endif
650 	    (session->reorder_timeout &&
651 	     nla_put_msecs(skb, L2TP_ATTR_RECV_TIMEOUT, session->reorder_timeout)))
652 		goto nla_put_failure;
653 
654 	nest = nla_nest_start(skb, L2TP_ATTR_STATS);
655 	if (nest == NULL)
656 		goto nla_put_failure;
657 
658 	do {
659 		start = u64_stats_fetch_begin(&session->stats.syncp);
660 		stats.tx_packets = session->stats.tx_packets;
661 		stats.tx_bytes = session->stats.tx_bytes;
662 		stats.tx_errors = session->stats.tx_errors;
663 		stats.rx_packets = session->stats.rx_packets;
664 		stats.rx_bytes = session->stats.rx_bytes;
665 		stats.rx_errors = session->stats.rx_errors;
666 		stats.rx_seq_discards = session->stats.rx_seq_discards;
667 		stats.rx_oos_packets = session->stats.rx_oos_packets;
668 	} while (u64_stats_fetch_retry(&session->stats.syncp, start));
669 
670 	if (nla_put_u64(skb, L2TP_ATTR_TX_PACKETS, stats.tx_packets) ||
671 	    nla_put_u64(skb, L2TP_ATTR_TX_BYTES, stats.tx_bytes) ||
672 	    nla_put_u64(skb, L2TP_ATTR_TX_ERRORS, stats.tx_errors) ||
673 	    nla_put_u64(skb, L2TP_ATTR_RX_PACKETS, stats.rx_packets) ||
674 	    nla_put_u64(skb, L2TP_ATTR_RX_BYTES, stats.rx_bytes) ||
675 	    nla_put_u64(skb, L2TP_ATTR_RX_SEQ_DISCARDS,
676 			stats.rx_seq_discards) ||
677 	    nla_put_u64(skb, L2TP_ATTR_RX_OOS_PACKETS,
678 			stats.rx_oos_packets) ||
679 	    nla_put_u64(skb, L2TP_ATTR_RX_ERRORS, stats.rx_errors))
680 		goto nla_put_failure;
681 	nla_nest_end(skb, nest);
682 
683 	return genlmsg_end(skb, hdr);
684 
685  nla_put_failure:
686 	genlmsg_cancel(skb, hdr);
687 	return -1;
688 }
689 
690 static int l2tp_nl_cmd_session_get(struct sk_buff *skb, struct genl_info *info)
691 {
692 	struct l2tp_session *session;
693 	struct sk_buff *msg;
694 	int ret;
695 
696 	session = l2tp_nl_session_find(info);
697 	if (session == NULL) {
698 		ret = -ENODEV;
699 		goto out;
700 	}
701 
702 	msg = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);
703 	if (!msg) {
704 		ret = -ENOMEM;
705 		goto out;
706 	}
707 
708 	ret = l2tp_nl_session_send(msg, info->snd_pid, info->snd_seq,
709 				   0, session);
710 	if (ret < 0)
711 		goto err_out;
712 
713 	return genlmsg_unicast(genl_info_net(info), msg, info->snd_pid);
714 
715 err_out:
716 	nlmsg_free(msg);
717 
718 out:
719 	return ret;
720 }
721 
722 static int l2tp_nl_cmd_session_dump(struct sk_buff *skb, struct netlink_callback *cb)
723 {
724 	struct net *net = sock_net(skb->sk);
725 	struct l2tp_session *session;
726 	struct l2tp_tunnel *tunnel = NULL;
727 	int ti = cb->args[0];
728 	int si = cb->args[1];
729 
730 	for (;;) {
731 		if (tunnel == NULL) {
732 			tunnel = l2tp_tunnel_find_nth(net, ti);
733 			if (tunnel == NULL)
734 				goto out;
735 		}
736 
737 		session = l2tp_session_find_nth(tunnel, si);
738 		if (session == NULL) {
739 			ti++;
740 			tunnel = NULL;
741 			si = 0;
742 			continue;
743 		}
744 
745 		if (l2tp_nl_session_send(skb, NETLINK_CB(cb->skb).pid,
746 					 cb->nlh->nlmsg_seq, NLM_F_MULTI,
747 					 session) <= 0)
748 			break;
749 
750 		si++;
751 	}
752 
753 out:
754 	cb->args[0] = ti;
755 	cb->args[1] = si;
756 
757 	return skb->len;
758 }
759 
760 static struct nla_policy l2tp_nl_policy[L2TP_ATTR_MAX + 1] = {
761 	[L2TP_ATTR_NONE]		= { .type = NLA_UNSPEC, },
762 	[L2TP_ATTR_PW_TYPE]		= { .type = NLA_U16, },
763 	[L2TP_ATTR_ENCAP_TYPE]		= { .type = NLA_U16, },
764 	[L2TP_ATTR_OFFSET]		= { .type = NLA_U16, },
765 	[L2TP_ATTR_DATA_SEQ]		= { .type = NLA_U8, },
766 	[L2TP_ATTR_L2SPEC_TYPE]		= { .type = NLA_U8, },
767 	[L2TP_ATTR_L2SPEC_LEN]		= { .type = NLA_U8, },
768 	[L2TP_ATTR_PROTO_VERSION]	= { .type = NLA_U8, },
769 	[L2TP_ATTR_CONN_ID]		= { .type = NLA_U32, },
770 	[L2TP_ATTR_PEER_CONN_ID]	= { .type = NLA_U32, },
771 	[L2TP_ATTR_SESSION_ID]		= { .type = NLA_U32, },
772 	[L2TP_ATTR_PEER_SESSION_ID]	= { .type = NLA_U32, },
773 	[L2TP_ATTR_UDP_CSUM]		= { .type = NLA_U8, },
774 	[L2TP_ATTR_VLAN_ID]		= { .type = NLA_U16, },
775 	[L2TP_ATTR_DEBUG]		= { .type = NLA_U32, },
776 	[L2TP_ATTR_RECV_SEQ]		= { .type = NLA_U8, },
777 	[L2TP_ATTR_SEND_SEQ]		= { .type = NLA_U8, },
778 	[L2TP_ATTR_LNS_MODE]		= { .type = NLA_U8, },
779 	[L2TP_ATTR_USING_IPSEC]		= { .type = NLA_U8, },
780 	[L2TP_ATTR_RECV_TIMEOUT]	= { .type = NLA_MSECS, },
781 	[L2TP_ATTR_FD]			= { .type = NLA_U32, },
782 	[L2TP_ATTR_IP_SADDR]		= { .type = NLA_U32, },
783 	[L2TP_ATTR_IP_DADDR]		= { .type = NLA_U32, },
784 	[L2TP_ATTR_UDP_SPORT]		= { .type = NLA_U16, },
785 	[L2TP_ATTR_UDP_DPORT]		= { .type = NLA_U16, },
786 	[L2TP_ATTR_MTU]			= { .type = NLA_U16, },
787 	[L2TP_ATTR_MRU]			= { .type = NLA_U16, },
788 	[L2TP_ATTR_STATS]		= { .type = NLA_NESTED, },
789 	[L2TP_ATTR_IP6_SADDR] = {
790 		.type = NLA_BINARY,
791 		.len = sizeof(struct in6_addr),
792 	},
793 	[L2TP_ATTR_IP6_DADDR] = {
794 		.type = NLA_BINARY,
795 		.len = sizeof(struct in6_addr),
796 	},
797 	[L2TP_ATTR_IFNAME] = {
798 		.type = NLA_NUL_STRING,
799 		.len = IFNAMSIZ - 1,
800 	},
801 	[L2TP_ATTR_COOKIE] = {
802 		.type = NLA_BINARY,
803 		.len = 8,
804 	},
805 	[L2TP_ATTR_PEER_COOKIE] = {
806 		.type = NLA_BINARY,
807 		.len = 8,
808 	},
809 };
810 
811 static struct genl_ops l2tp_nl_ops[] = {
812 	{
813 		.cmd = L2TP_CMD_NOOP,
814 		.doit = l2tp_nl_cmd_noop,
815 		.policy = l2tp_nl_policy,
816 		/* can be retrieved by unprivileged users */
817 	},
818 	{
819 		.cmd = L2TP_CMD_TUNNEL_CREATE,
820 		.doit = l2tp_nl_cmd_tunnel_create,
821 		.policy = l2tp_nl_policy,
822 		.flags = GENL_ADMIN_PERM,
823 	},
824 	{
825 		.cmd = L2TP_CMD_TUNNEL_DELETE,
826 		.doit = l2tp_nl_cmd_tunnel_delete,
827 		.policy = l2tp_nl_policy,
828 		.flags = GENL_ADMIN_PERM,
829 	},
830 	{
831 		.cmd = L2TP_CMD_TUNNEL_MODIFY,
832 		.doit = l2tp_nl_cmd_tunnel_modify,
833 		.policy = l2tp_nl_policy,
834 		.flags = GENL_ADMIN_PERM,
835 	},
836 	{
837 		.cmd = L2TP_CMD_TUNNEL_GET,
838 		.doit = l2tp_nl_cmd_tunnel_get,
839 		.dumpit = l2tp_nl_cmd_tunnel_dump,
840 		.policy = l2tp_nl_policy,
841 		.flags = GENL_ADMIN_PERM,
842 	},
843 	{
844 		.cmd = L2TP_CMD_SESSION_CREATE,
845 		.doit = l2tp_nl_cmd_session_create,
846 		.policy = l2tp_nl_policy,
847 		.flags = GENL_ADMIN_PERM,
848 	},
849 	{
850 		.cmd = L2TP_CMD_SESSION_DELETE,
851 		.doit = l2tp_nl_cmd_session_delete,
852 		.policy = l2tp_nl_policy,
853 		.flags = GENL_ADMIN_PERM,
854 	},
855 	{
856 		.cmd = L2TP_CMD_SESSION_MODIFY,
857 		.doit = l2tp_nl_cmd_session_modify,
858 		.policy = l2tp_nl_policy,
859 		.flags = GENL_ADMIN_PERM,
860 	},
861 	{
862 		.cmd = L2TP_CMD_SESSION_GET,
863 		.doit = l2tp_nl_cmd_session_get,
864 		.dumpit = l2tp_nl_cmd_session_dump,
865 		.policy = l2tp_nl_policy,
866 		.flags = GENL_ADMIN_PERM,
867 	},
868 };
869 
870 int l2tp_nl_register_ops(enum l2tp_pwtype pw_type, const struct l2tp_nl_cmd_ops *ops)
871 {
872 	int ret;
873 
874 	ret = -EINVAL;
875 	if (pw_type >= __L2TP_PWTYPE_MAX)
876 		goto err;
877 
878 	genl_lock();
879 	ret = -EBUSY;
880 	if (l2tp_nl_cmd_ops[pw_type])
881 		goto out;
882 
883 	l2tp_nl_cmd_ops[pw_type] = ops;
884 	ret = 0;
885 
886 out:
887 	genl_unlock();
888 err:
889 	return ret;
890 }
891 EXPORT_SYMBOL_GPL(l2tp_nl_register_ops);
892 
893 void l2tp_nl_unregister_ops(enum l2tp_pwtype pw_type)
894 {
895 	if (pw_type < __L2TP_PWTYPE_MAX) {
896 		genl_lock();
897 		l2tp_nl_cmd_ops[pw_type] = NULL;
898 		genl_unlock();
899 	}
900 }
901 EXPORT_SYMBOL_GPL(l2tp_nl_unregister_ops);
902 
903 static int l2tp_nl_init(void)
904 {
905 	int err;
906 
907 	pr_info("L2TP netlink interface\n");
908 	err = genl_register_family_with_ops(&l2tp_nl_family, l2tp_nl_ops,
909 					    ARRAY_SIZE(l2tp_nl_ops));
910 
911 	return err;
912 }
913 
914 static void l2tp_nl_cleanup(void)
915 {
916 	genl_unregister_family(&l2tp_nl_family);
917 }
918 
919 module_init(l2tp_nl_init);
920 module_exit(l2tp_nl_cleanup);
921 
922 MODULE_AUTHOR("James Chapman <jchapman@katalix.com>");
923 MODULE_DESCRIPTION("L2TP netlink");
924 MODULE_LICENSE("GPL");
925 MODULE_VERSION("1.0");
926 MODULE_ALIAS_GENL_FAMILY("l2tp");
927