1 // SPDX-License-Identifier: GPL-2.0-only
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
13 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
14
15 #include <net/sock.h>
16 #include <net/genetlink.h>
17 #include <net/udp.h>
18 #include <linux/in.h>
19 #include <linux/udp.h>
20 #include <linux/socket.h>
21 #include <linux/module.h>
22 #include <linux/list.h>
23 #include <net/net_namespace.h>
24
25 #include <linux/l2tp.h>
26
27 #include "l2tp_core.h"
28
29 static struct genl_family l2tp_nl_family;
30
31 static const struct genl_multicast_group l2tp_multicast_group[] = {
32 {
33 .name = L2TP_GENL_MCGROUP,
34 },
35 };
36
37 static int l2tp_nl_tunnel_send(struct sk_buff *skb, u32 portid, u32 seq,
38 int flags, struct l2tp_tunnel *tunnel, u8 cmd);
39 static int l2tp_nl_session_send(struct sk_buff *skb, u32 portid, u32 seq,
40 int flags, struct l2tp_session *session,
41 u8 cmd);
42
43 /* Accessed under genl lock */
44 static const struct l2tp_nl_cmd_ops *l2tp_nl_cmd_ops[__L2TP_PWTYPE_MAX];
45
l2tp_nl_session_get(struct genl_info * info)46 static struct l2tp_session *l2tp_nl_session_get(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_get_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_get(net, tunnel_id);
63 if (tunnel) {
64 session = l2tp_session_get(net, tunnel->sock, tunnel->version,
65 tunnel_id, session_id);
66 l2tp_tunnel_put(tunnel);
67 }
68 }
69
70 return session;
71 }
72
l2tp_nl_cmd_noop(struct sk_buff * skb,struct genl_info * info)73 static int l2tp_nl_cmd_noop(struct sk_buff *skb, struct genl_info *info)
74 {
75 struct sk_buff *msg;
76 void *hdr;
77 int ret = -ENOBUFS;
78
79 msg = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);
80 if (!msg) {
81 ret = -ENOMEM;
82 goto out;
83 }
84
85 hdr = genlmsg_put(msg, info->snd_portid, info->snd_seq,
86 &l2tp_nl_family, 0, L2TP_CMD_NOOP);
87 if (!hdr) {
88 ret = -EMSGSIZE;
89 goto err_out;
90 }
91
92 genlmsg_end(msg, hdr);
93
94 return genlmsg_unicast(genl_info_net(info), msg, info->snd_portid);
95
96 err_out:
97 nlmsg_free(msg);
98
99 out:
100 return ret;
101 }
102
l2tp_tunnel_notify(struct genl_family * family,struct genl_info * info,struct l2tp_tunnel * tunnel,u8 cmd)103 static int l2tp_tunnel_notify(struct genl_family *family,
104 struct genl_info *info,
105 struct l2tp_tunnel *tunnel,
106 u8 cmd)
107 {
108 struct sk_buff *msg;
109 int ret;
110
111 msg = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);
112 if (!msg)
113 return -ENOMEM;
114
115 ret = l2tp_nl_tunnel_send(msg, info->snd_portid, info->snd_seq,
116 NLM_F_ACK, tunnel, cmd);
117
118 if (ret >= 0) {
119 ret = genlmsg_multicast_netns(family, tunnel->l2tp_net, msg,
120 0, 0, GFP_KERNEL);
121 /* We don't care if no one is listening */
122 if (ret == -ESRCH)
123 ret = 0;
124 return ret;
125 }
126
127 nlmsg_free(msg);
128
129 return ret;
130 }
131
l2tp_session_notify(struct genl_family * family,struct genl_info * info,struct l2tp_session * session,u8 cmd)132 static int l2tp_session_notify(struct genl_family *family,
133 struct genl_info *info,
134 struct l2tp_session *session,
135 u8 cmd)
136 {
137 struct sk_buff *msg;
138 int ret;
139
140 msg = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);
141 if (!msg)
142 return -ENOMEM;
143
144 ret = l2tp_nl_session_send(msg, info->snd_portid, info->snd_seq,
145 NLM_F_ACK, session, cmd);
146
147 if (ret >= 0) {
148 ret = genlmsg_multicast_netns(family,
149 session->tunnel->l2tp_net, msg,
150 0, 0, GFP_KERNEL);
151 /* We don't care if no one is listening */
152 if (ret == -ESRCH)
153 ret = 0;
154 return ret;
155 }
156
157 nlmsg_free(msg);
158
159 return ret;
160 }
161
l2tp_nl_cmd_tunnel_create_get_addr(struct nlattr ** attrs,struct l2tp_tunnel_cfg * cfg)162 static int l2tp_nl_cmd_tunnel_create_get_addr(struct nlattr **attrs, struct l2tp_tunnel_cfg *cfg)
163 {
164 if (attrs[L2TP_ATTR_UDP_SPORT])
165 cfg->local_udp_port = nla_get_u16(attrs[L2TP_ATTR_UDP_SPORT]);
166 if (attrs[L2TP_ATTR_UDP_DPORT])
167 cfg->peer_udp_port = nla_get_u16(attrs[L2TP_ATTR_UDP_DPORT]);
168 cfg->use_udp_checksums = nla_get_flag(attrs[L2TP_ATTR_UDP_CSUM]);
169
170 /* Must have either AF_INET or AF_INET6 address for source and destination */
171 #if IS_ENABLED(CONFIG_IPV6)
172 if (attrs[L2TP_ATTR_IP6_SADDR] && attrs[L2TP_ATTR_IP6_DADDR]) {
173 cfg->local_ip6 = nla_data(attrs[L2TP_ATTR_IP6_SADDR]);
174 cfg->peer_ip6 = nla_data(attrs[L2TP_ATTR_IP6_DADDR]);
175 cfg->udp6_zero_tx_checksums = nla_get_flag(attrs[L2TP_ATTR_UDP_ZERO_CSUM6_TX]);
176 cfg->udp6_zero_rx_checksums = nla_get_flag(attrs[L2TP_ATTR_UDP_ZERO_CSUM6_RX]);
177 return 0;
178 }
179 #endif
180 if (attrs[L2TP_ATTR_IP_SADDR] && attrs[L2TP_ATTR_IP_DADDR]) {
181 cfg->local_ip.s_addr = nla_get_in_addr(attrs[L2TP_ATTR_IP_SADDR]);
182 cfg->peer_ip.s_addr = nla_get_in_addr(attrs[L2TP_ATTR_IP_DADDR]);
183 return 0;
184 }
185 return -EINVAL;
186 }
187
l2tp_nl_cmd_tunnel_create(struct sk_buff * skb,struct genl_info * info)188 static int l2tp_nl_cmd_tunnel_create(struct sk_buff *skb, struct genl_info *info)
189 {
190 u32 tunnel_id;
191 u32 peer_tunnel_id;
192 int proto_version;
193 int fd = -1;
194 int ret = 0;
195 struct l2tp_tunnel_cfg cfg = { 0, };
196 struct l2tp_tunnel *tunnel;
197 struct net *net = genl_info_net(info);
198 struct nlattr **attrs = info->attrs;
199
200 if (!attrs[L2TP_ATTR_CONN_ID]) {
201 ret = -EINVAL;
202 goto out;
203 }
204 tunnel_id = nla_get_u32(attrs[L2TP_ATTR_CONN_ID]);
205
206 if (!attrs[L2TP_ATTR_PEER_CONN_ID]) {
207 ret = -EINVAL;
208 goto out;
209 }
210 peer_tunnel_id = nla_get_u32(attrs[L2TP_ATTR_PEER_CONN_ID]);
211
212 if (!attrs[L2TP_ATTR_PROTO_VERSION]) {
213 ret = -EINVAL;
214 goto out;
215 }
216 proto_version = nla_get_u8(attrs[L2TP_ATTR_PROTO_VERSION]);
217
218 if (!attrs[L2TP_ATTR_ENCAP_TYPE]) {
219 ret = -EINVAL;
220 goto out;
221 }
222 cfg.encap = nla_get_u16(attrs[L2TP_ATTR_ENCAP_TYPE]);
223
224 /* Managed tunnels take the tunnel socket from userspace.
225 * Unmanaged tunnels must call out the source and destination addresses
226 * for the kernel to create the tunnel socket itself.
227 */
228 if (attrs[L2TP_ATTR_FD]) {
229 fd = nla_get_u32(attrs[L2TP_ATTR_FD]);
230 } else {
231 ret = l2tp_nl_cmd_tunnel_create_get_addr(attrs, &cfg);
232 if (ret < 0)
233 goto out;
234 }
235
236 ret = -EINVAL;
237 switch (cfg.encap) {
238 case L2TP_ENCAPTYPE_UDP:
239 case L2TP_ENCAPTYPE_IP:
240 ret = l2tp_tunnel_create(fd, proto_version, tunnel_id,
241 peer_tunnel_id, &cfg, &tunnel);
242 break;
243 }
244
245 if (ret < 0)
246 goto out;
247
248 refcount_inc(&tunnel->ref_count);
249 ret = l2tp_tunnel_register(tunnel, net, &cfg);
250 if (ret < 0) {
251 kfree(tunnel);
252 goto out;
253 }
254 l2tp_tunnel_notify(&l2tp_nl_family, info, tunnel,
255 L2TP_CMD_TUNNEL_CREATE);
256 l2tp_tunnel_put(tunnel);
257
258 out:
259 return ret;
260 }
261
l2tp_nl_cmd_tunnel_delete(struct sk_buff * skb,struct genl_info * info)262 static int l2tp_nl_cmd_tunnel_delete(struct sk_buff *skb, struct genl_info *info)
263 {
264 struct l2tp_tunnel *tunnel;
265 u32 tunnel_id;
266 int ret = 0;
267 struct net *net = genl_info_net(info);
268
269 if (!info->attrs[L2TP_ATTR_CONN_ID]) {
270 ret = -EINVAL;
271 goto out;
272 }
273 tunnel_id = nla_get_u32(info->attrs[L2TP_ATTR_CONN_ID]);
274
275 tunnel = l2tp_tunnel_get(net, tunnel_id);
276 if (!tunnel) {
277 ret = -ENODEV;
278 goto out;
279 }
280
281 l2tp_tunnel_notify(&l2tp_nl_family, info,
282 tunnel, L2TP_CMD_TUNNEL_DELETE);
283
284 l2tp_tunnel_delete(tunnel);
285
286 l2tp_tunnel_put(tunnel);
287
288 out:
289 return ret;
290 }
291
l2tp_nl_cmd_tunnel_modify(struct sk_buff * skb,struct genl_info * info)292 static int l2tp_nl_cmd_tunnel_modify(struct sk_buff *skb, struct genl_info *info)
293 {
294 struct l2tp_tunnel *tunnel;
295 u32 tunnel_id;
296 int ret = 0;
297 struct net *net = genl_info_net(info);
298
299 if (!info->attrs[L2TP_ATTR_CONN_ID]) {
300 ret = -EINVAL;
301 goto out;
302 }
303 tunnel_id = nla_get_u32(info->attrs[L2TP_ATTR_CONN_ID]);
304
305 tunnel = l2tp_tunnel_get(net, tunnel_id);
306 if (!tunnel) {
307 ret = -ENODEV;
308 goto out;
309 }
310
311 l2tp_tunnel_notify(&l2tp_nl_family, info,
312 tunnel, L2TP_CMD_TUNNEL_MODIFY);
313
314 l2tp_tunnel_put(tunnel);
315
316 out:
317 return ret;
318 }
319
320 #if IS_ENABLED(CONFIG_IPV6)
l2tp_nl_tunnel_send_addr6(struct sk_buff * skb,struct sock * sk,enum l2tp_encap_type encap)321 static int l2tp_nl_tunnel_send_addr6(struct sk_buff *skb, struct sock *sk,
322 enum l2tp_encap_type encap)
323 {
324 struct inet_sock *inet = inet_sk(sk);
325 struct ipv6_pinfo *np = inet6_sk(sk);
326
327 switch (encap) {
328 case L2TP_ENCAPTYPE_UDP:
329 if (udp_get_no_check6_tx(sk) &&
330 nla_put_flag(skb, L2TP_ATTR_UDP_ZERO_CSUM6_TX))
331 return -1;
332 if (udp_get_no_check6_rx(sk) &&
333 nla_put_flag(skb, L2TP_ATTR_UDP_ZERO_CSUM6_RX))
334 return -1;
335 if (nla_put_u16(skb, L2TP_ATTR_UDP_SPORT, ntohs(inet->inet_sport)) ||
336 nla_put_u16(skb, L2TP_ATTR_UDP_DPORT, ntohs(inet->inet_dport)))
337 return -1;
338 fallthrough;
339 case L2TP_ENCAPTYPE_IP:
340 if (nla_put_in6_addr(skb, L2TP_ATTR_IP6_SADDR, &np->saddr) ||
341 nla_put_in6_addr(skb, L2TP_ATTR_IP6_DADDR, &sk->sk_v6_daddr))
342 return -1;
343 break;
344 }
345 return 0;
346 }
347 #endif
348
l2tp_nl_tunnel_send_addr4(struct sk_buff * skb,struct sock * sk,enum l2tp_encap_type encap)349 static int l2tp_nl_tunnel_send_addr4(struct sk_buff *skb, struct sock *sk,
350 enum l2tp_encap_type encap)
351 {
352 struct inet_sock *inet = inet_sk(sk);
353
354 switch (encap) {
355 case L2TP_ENCAPTYPE_UDP:
356 if (nla_put_u8(skb, L2TP_ATTR_UDP_CSUM, !sk->sk_no_check_tx) ||
357 nla_put_u16(skb, L2TP_ATTR_UDP_SPORT, ntohs(inet->inet_sport)) ||
358 nla_put_u16(skb, L2TP_ATTR_UDP_DPORT, ntohs(inet->inet_dport)))
359 return -1;
360 fallthrough;
361 case L2TP_ENCAPTYPE_IP:
362 if (nla_put_in_addr(skb, L2TP_ATTR_IP_SADDR, inet->inet_saddr) ||
363 nla_put_in_addr(skb, L2TP_ATTR_IP_DADDR, inet->inet_daddr))
364 return -1;
365 break;
366 }
367
368 return 0;
369 }
370
371 /* Append attributes for the tunnel address, handling the different attribute types
372 * used for different tunnel encapsulation and AF_INET v.s. AF_INET6.
373 */
l2tp_nl_tunnel_send_addr(struct sk_buff * skb,struct l2tp_tunnel * tunnel)374 static int l2tp_nl_tunnel_send_addr(struct sk_buff *skb, struct l2tp_tunnel *tunnel)
375 {
376 struct sock *sk = tunnel->sock;
377
378 if (!sk)
379 return 0;
380
381 #if IS_ENABLED(CONFIG_IPV6)
382 if (sk->sk_family == AF_INET6)
383 return l2tp_nl_tunnel_send_addr6(skb, sk, tunnel->encap);
384 #endif
385 return l2tp_nl_tunnel_send_addr4(skb, sk, tunnel->encap);
386 }
387
l2tp_nl_tunnel_send(struct sk_buff * skb,u32 portid,u32 seq,int flags,struct l2tp_tunnel * tunnel,u8 cmd)388 static int l2tp_nl_tunnel_send(struct sk_buff *skb, u32 portid, u32 seq, int flags,
389 struct l2tp_tunnel *tunnel, u8 cmd)
390 {
391 void *hdr;
392 struct nlattr *nest;
393
394 hdr = genlmsg_put(skb, portid, seq, &l2tp_nl_family, flags, cmd);
395 if (!hdr)
396 return -EMSGSIZE;
397
398 if (nla_put_u8(skb, L2TP_ATTR_PROTO_VERSION, tunnel->version) ||
399 nla_put_u32(skb, L2TP_ATTR_CONN_ID, tunnel->tunnel_id) ||
400 nla_put_u32(skb, L2TP_ATTR_PEER_CONN_ID, tunnel->peer_tunnel_id) ||
401 nla_put_u32(skb, L2TP_ATTR_DEBUG, 0) ||
402 nla_put_u16(skb, L2TP_ATTR_ENCAP_TYPE, tunnel->encap))
403 goto nla_put_failure;
404
405 nest = nla_nest_start_noflag(skb, L2TP_ATTR_STATS);
406 if (!nest)
407 goto nla_put_failure;
408
409 if (nla_put_u64_64bit(skb, L2TP_ATTR_TX_PACKETS,
410 atomic_long_read(&tunnel->stats.tx_packets),
411 L2TP_ATTR_STATS_PAD) ||
412 nla_put_u64_64bit(skb, L2TP_ATTR_TX_BYTES,
413 atomic_long_read(&tunnel->stats.tx_bytes),
414 L2TP_ATTR_STATS_PAD) ||
415 nla_put_u64_64bit(skb, L2TP_ATTR_TX_ERRORS,
416 atomic_long_read(&tunnel->stats.tx_errors),
417 L2TP_ATTR_STATS_PAD) ||
418 nla_put_u64_64bit(skb, L2TP_ATTR_RX_PACKETS,
419 atomic_long_read(&tunnel->stats.rx_packets),
420 L2TP_ATTR_STATS_PAD) ||
421 nla_put_u64_64bit(skb, L2TP_ATTR_RX_BYTES,
422 atomic_long_read(&tunnel->stats.rx_bytes),
423 L2TP_ATTR_STATS_PAD) ||
424 nla_put_u64_64bit(skb, L2TP_ATTR_RX_SEQ_DISCARDS,
425 atomic_long_read(&tunnel->stats.rx_seq_discards),
426 L2TP_ATTR_STATS_PAD) ||
427 nla_put_u64_64bit(skb, L2TP_ATTR_RX_COOKIE_DISCARDS,
428 atomic_long_read(&tunnel->stats.rx_cookie_discards),
429 L2TP_ATTR_STATS_PAD) ||
430 nla_put_u64_64bit(skb, L2TP_ATTR_RX_OOS_PACKETS,
431 atomic_long_read(&tunnel->stats.rx_oos_packets),
432 L2TP_ATTR_STATS_PAD) ||
433 nla_put_u64_64bit(skb, L2TP_ATTR_RX_ERRORS,
434 atomic_long_read(&tunnel->stats.rx_errors),
435 L2TP_ATTR_STATS_PAD) ||
436 nla_put_u64_64bit(skb, L2TP_ATTR_RX_INVALID,
437 atomic_long_read(&tunnel->stats.rx_invalid),
438 L2TP_ATTR_STATS_PAD))
439 goto nla_put_failure;
440 nla_nest_end(skb, nest);
441
442 if (l2tp_nl_tunnel_send_addr(skb, tunnel))
443 goto nla_put_failure;
444
445 genlmsg_end(skb, hdr);
446 return 0;
447
448 nla_put_failure:
449 genlmsg_cancel(skb, hdr);
450 return -1;
451 }
452
l2tp_nl_cmd_tunnel_get(struct sk_buff * skb,struct genl_info * info)453 static int l2tp_nl_cmd_tunnel_get(struct sk_buff *skb, struct genl_info *info)
454 {
455 struct l2tp_tunnel *tunnel;
456 struct sk_buff *msg;
457 u32 tunnel_id;
458 int ret = -ENOBUFS;
459 struct net *net = genl_info_net(info);
460
461 if (!info->attrs[L2TP_ATTR_CONN_ID]) {
462 ret = -EINVAL;
463 goto err;
464 }
465
466 tunnel_id = nla_get_u32(info->attrs[L2TP_ATTR_CONN_ID]);
467
468 msg = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);
469 if (!msg) {
470 ret = -ENOMEM;
471 goto err;
472 }
473
474 tunnel = l2tp_tunnel_get(net, tunnel_id);
475 if (!tunnel) {
476 ret = -ENODEV;
477 goto err_nlmsg;
478 }
479
480 ret = l2tp_nl_tunnel_send(msg, info->snd_portid, info->snd_seq,
481 NLM_F_ACK, tunnel, L2TP_CMD_TUNNEL_GET);
482 if (ret < 0)
483 goto err_nlmsg_tunnel;
484
485 l2tp_tunnel_put(tunnel);
486
487 return genlmsg_unicast(net, msg, info->snd_portid);
488
489 err_nlmsg_tunnel:
490 l2tp_tunnel_put(tunnel);
491 err_nlmsg:
492 nlmsg_free(msg);
493 err:
494 return ret;
495 }
496
497 struct l2tp_nl_cb_data {
498 unsigned long tkey;
499 unsigned long skey;
500 };
501
l2tp_nl_cmd_tunnel_dump(struct sk_buff * skb,struct netlink_callback * cb)502 static int l2tp_nl_cmd_tunnel_dump(struct sk_buff *skb, struct netlink_callback *cb)
503 {
504 struct l2tp_nl_cb_data *cbd = (void *)&cb->ctx[0];
505 unsigned long key = cbd->tkey;
506 struct l2tp_tunnel *tunnel;
507 struct net *net = sock_net(skb->sk);
508
509 for (;;) {
510 tunnel = l2tp_tunnel_get_next(net, &key);
511 if (!tunnel)
512 goto out;
513
514 if (l2tp_nl_tunnel_send(skb, NETLINK_CB(cb->skb).portid,
515 cb->nlh->nlmsg_seq, NLM_F_MULTI,
516 tunnel, L2TP_CMD_TUNNEL_GET) < 0) {
517 l2tp_tunnel_put(tunnel);
518 goto out;
519 }
520 l2tp_tunnel_put(tunnel);
521
522 key++;
523 }
524
525 out:
526 cbd->tkey = key;
527
528 return skb->len;
529 }
530
l2tp_nl_cmd_session_create(struct sk_buff * skb,struct genl_info * info)531 static int l2tp_nl_cmd_session_create(struct sk_buff *skb, struct genl_info *info)
532 {
533 u32 tunnel_id = 0;
534 u32 session_id;
535 u32 peer_session_id;
536 int ret = 0;
537 struct l2tp_tunnel *tunnel;
538 struct l2tp_session *session;
539 struct l2tp_session_cfg cfg = { 0, };
540 struct net *net = genl_info_net(info);
541
542 if (!info->attrs[L2TP_ATTR_CONN_ID]) {
543 ret = -EINVAL;
544 goto out;
545 }
546
547 tunnel_id = nla_get_u32(info->attrs[L2TP_ATTR_CONN_ID]);
548 tunnel = l2tp_tunnel_get(net, tunnel_id);
549 if (!tunnel) {
550 ret = -ENODEV;
551 goto out;
552 }
553
554 if (!info->attrs[L2TP_ATTR_SESSION_ID]) {
555 ret = -EINVAL;
556 goto out_tunnel;
557 }
558 session_id = nla_get_u32(info->attrs[L2TP_ATTR_SESSION_ID]);
559
560 if (!info->attrs[L2TP_ATTR_PEER_SESSION_ID]) {
561 ret = -EINVAL;
562 goto out_tunnel;
563 }
564 peer_session_id = nla_get_u32(info->attrs[L2TP_ATTR_PEER_SESSION_ID]);
565
566 if (!info->attrs[L2TP_ATTR_PW_TYPE]) {
567 ret = -EINVAL;
568 goto out_tunnel;
569 }
570 cfg.pw_type = nla_get_u16(info->attrs[L2TP_ATTR_PW_TYPE]);
571 if (cfg.pw_type >= __L2TP_PWTYPE_MAX) {
572 ret = -EINVAL;
573 goto out_tunnel;
574 }
575
576 /* L2TPv2 only accepts PPP pseudo-wires */
577 if (tunnel->version == 2 && cfg.pw_type != L2TP_PWTYPE_PPP) {
578 ret = -EPROTONOSUPPORT;
579 goto out_tunnel;
580 }
581
582 if (tunnel->version > 2) {
583 if (info->attrs[L2TP_ATTR_L2SPEC_TYPE]) {
584 cfg.l2specific_type = nla_get_u8(info->attrs[L2TP_ATTR_L2SPEC_TYPE]);
585 if (cfg.l2specific_type != L2TP_L2SPECTYPE_DEFAULT &&
586 cfg.l2specific_type != L2TP_L2SPECTYPE_NONE) {
587 ret = -EINVAL;
588 goto out_tunnel;
589 }
590 } else {
591 cfg.l2specific_type = L2TP_L2SPECTYPE_DEFAULT;
592 }
593
594 if (info->attrs[L2TP_ATTR_COOKIE]) {
595 u16 len = nla_len(info->attrs[L2TP_ATTR_COOKIE]);
596
597 if (len > 8) {
598 ret = -EINVAL;
599 goto out_tunnel;
600 }
601 cfg.cookie_len = len;
602 memcpy(&cfg.cookie[0], nla_data(info->attrs[L2TP_ATTR_COOKIE]), len);
603 }
604 if (info->attrs[L2TP_ATTR_PEER_COOKIE]) {
605 u16 len = nla_len(info->attrs[L2TP_ATTR_PEER_COOKIE]);
606
607 if (len > 8) {
608 ret = -EINVAL;
609 goto out_tunnel;
610 }
611 cfg.peer_cookie_len = len;
612 memcpy(&cfg.peer_cookie[0], nla_data(info->attrs[L2TP_ATTR_PEER_COOKIE]), len);
613 }
614 if (info->attrs[L2TP_ATTR_IFNAME])
615 cfg.ifname = nla_data(info->attrs[L2TP_ATTR_IFNAME]);
616 }
617
618 if (info->attrs[L2TP_ATTR_RECV_SEQ])
619 cfg.recv_seq = nla_get_u8(info->attrs[L2TP_ATTR_RECV_SEQ]);
620
621 if (info->attrs[L2TP_ATTR_SEND_SEQ])
622 cfg.send_seq = nla_get_u8(info->attrs[L2TP_ATTR_SEND_SEQ]);
623
624 if (info->attrs[L2TP_ATTR_LNS_MODE])
625 cfg.lns_mode = nla_get_u8(info->attrs[L2TP_ATTR_LNS_MODE]);
626
627 if (info->attrs[L2TP_ATTR_RECV_TIMEOUT])
628 cfg.reorder_timeout = nla_get_msecs(info->attrs[L2TP_ATTR_RECV_TIMEOUT]);
629
630 #ifdef CONFIG_MODULES
631 if (!l2tp_nl_cmd_ops[cfg.pw_type]) {
632 genl_unlock();
633 request_module("net-l2tp-type-%u", cfg.pw_type);
634 genl_lock();
635 }
636 #endif
637 if (!l2tp_nl_cmd_ops[cfg.pw_type] || !l2tp_nl_cmd_ops[cfg.pw_type]->session_create) {
638 ret = -EPROTONOSUPPORT;
639 goto out_tunnel;
640 }
641
642 ret = l2tp_nl_cmd_ops[cfg.pw_type]->session_create(net, tunnel,
643 session_id,
644 peer_session_id,
645 &cfg);
646
647 if (ret >= 0) {
648 session = l2tp_session_get(net, tunnel->sock, tunnel->version,
649 tunnel_id, session_id);
650 if (session) {
651 l2tp_session_notify(&l2tp_nl_family, info, session,
652 L2TP_CMD_SESSION_CREATE);
653 l2tp_session_put(session);
654 }
655 }
656
657 out_tunnel:
658 l2tp_tunnel_put(tunnel);
659 out:
660 return ret;
661 }
662
l2tp_nl_cmd_session_delete(struct sk_buff * skb,struct genl_info * info)663 static int l2tp_nl_cmd_session_delete(struct sk_buff *skb, struct genl_info *info)
664 {
665 int ret = 0;
666 struct l2tp_session *session;
667 u16 pw_type;
668
669 session = l2tp_nl_session_get(info);
670 if (!session) {
671 ret = -ENODEV;
672 goto out;
673 }
674
675 l2tp_session_notify(&l2tp_nl_family, info,
676 session, L2TP_CMD_SESSION_DELETE);
677
678 pw_type = session->pwtype;
679 if (pw_type < __L2TP_PWTYPE_MAX)
680 if (l2tp_nl_cmd_ops[pw_type] && l2tp_nl_cmd_ops[pw_type]->session_delete)
681 l2tp_nl_cmd_ops[pw_type]->session_delete(session);
682
683 l2tp_session_put(session);
684
685 out:
686 return ret;
687 }
688
l2tp_nl_cmd_session_modify(struct sk_buff * skb,struct genl_info * info)689 static int l2tp_nl_cmd_session_modify(struct sk_buff *skb, struct genl_info *info)
690 {
691 int ret = 0;
692 struct l2tp_session *session;
693
694 session = l2tp_nl_session_get(info);
695 if (!session) {
696 ret = -ENODEV;
697 goto out;
698 }
699
700 if (info->attrs[L2TP_ATTR_RECV_SEQ])
701 session->recv_seq = nla_get_u8(info->attrs[L2TP_ATTR_RECV_SEQ]);
702
703 if (info->attrs[L2TP_ATTR_SEND_SEQ]) {
704 struct l2tp_tunnel *tunnel = session->tunnel;
705
706 session->send_seq = nla_get_u8(info->attrs[L2TP_ATTR_SEND_SEQ]);
707 l2tp_session_set_header_len(session, tunnel->version, tunnel->encap);
708 }
709
710 if (info->attrs[L2TP_ATTR_LNS_MODE])
711 session->lns_mode = nla_get_u8(info->attrs[L2TP_ATTR_LNS_MODE]);
712
713 if (info->attrs[L2TP_ATTR_RECV_TIMEOUT])
714 session->reorder_timeout = nla_get_msecs(info->attrs[L2TP_ATTR_RECV_TIMEOUT]);
715
716 l2tp_session_notify(&l2tp_nl_family, info,
717 session, L2TP_CMD_SESSION_MODIFY);
718
719 l2tp_session_put(session);
720
721 out:
722 return ret;
723 }
724
l2tp_nl_session_send(struct sk_buff * skb,u32 portid,u32 seq,int flags,struct l2tp_session * session,u8 cmd)725 static int l2tp_nl_session_send(struct sk_buff *skb, u32 portid, u32 seq, int flags,
726 struct l2tp_session *session, u8 cmd)
727 {
728 void *hdr;
729 struct nlattr *nest;
730 struct l2tp_tunnel *tunnel = session->tunnel;
731
732 hdr = genlmsg_put(skb, portid, seq, &l2tp_nl_family, flags, cmd);
733 if (!hdr)
734 return -EMSGSIZE;
735
736 if (nla_put_u32(skb, L2TP_ATTR_CONN_ID, tunnel->tunnel_id) ||
737 nla_put_u32(skb, L2TP_ATTR_SESSION_ID, session->session_id) ||
738 nla_put_u32(skb, L2TP_ATTR_PEER_CONN_ID, tunnel->peer_tunnel_id) ||
739 nla_put_u32(skb, L2TP_ATTR_PEER_SESSION_ID, session->peer_session_id) ||
740 nla_put_u32(skb, L2TP_ATTR_DEBUG, 0) ||
741 nla_put_u16(skb, L2TP_ATTR_PW_TYPE, session->pwtype))
742 goto nla_put_failure;
743
744 if ((session->ifname[0] &&
745 nla_put_string(skb, L2TP_ATTR_IFNAME, session->ifname)) ||
746 (session->cookie_len &&
747 nla_put(skb, L2TP_ATTR_COOKIE, session->cookie_len, session->cookie)) ||
748 (session->peer_cookie_len &&
749 nla_put(skb, L2TP_ATTR_PEER_COOKIE, session->peer_cookie_len, session->peer_cookie)) ||
750 nla_put_u8(skb, L2TP_ATTR_RECV_SEQ, session->recv_seq) ||
751 nla_put_u8(skb, L2TP_ATTR_SEND_SEQ, session->send_seq) ||
752 nla_put_u8(skb, L2TP_ATTR_LNS_MODE, session->lns_mode) ||
753 (l2tp_tunnel_uses_xfrm(tunnel) &&
754 nla_put_u8(skb, L2TP_ATTR_USING_IPSEC, 1)) ||
755 (session->reorder_timeout &&
756 nla_put_msecs(skb, L2TP_ATTR_RECV_TIMEOUT,
757 session->reorder_timeout, L2TP_ATTR_PAD)))
758 goto nla_put_failure;
759
760 nest = nla_nest_start_noflag(skb, L2TP_ATTR_STATS);
761 if (!nest)
762 goto nla_put_failure;
763
764 if (nla_put_u64_64bit(skb, L2TP_ATTR_TX_PACKETS,
765 atomic_long_read(&session->stats.tx_packets),
766 L2TP_ATTR_STATS_PAD) ||
767 nla_put_u64_64bit(skb, L2TP_ATTR_TX_BYTES,
768 atomic_long_read(&session->stats.tx_bytes),
769 L2TP_ATTR_STATS_PAD) ||
770 nla_put_u64_64bit(skb, L2TP_ATTR_TX_ERRORS,
771 atomic_long_read(&session->stats.tx_errors),
772 L2TP_ATTR_STATS_PAD) ||
773 nla_put_u64_64bit(skb, L2TP_ATTR_RX_PACKETS,
774 atomic_long_read(&session->stats.rx_packets),
775 L2TP_ATTR_STATS_PAD) ||
776 nla_put_u64_64bit(skb, L2TP_ATTR_RX_BYTES,
777 atomic_long_read(&session->stats.rx_bytes),
778 L2TP_ATTR_STATS_PAD) ||
779 nla_put_u64_64bit(skb, L2TP_ATTR_RX_SEQ_DISCARDS,
780 atomic_long_read(&session->stats.rx_seq_discards),
781 L2TP_ATTR_STATS_PAD) ||
782 nla_put_u64_64bit(skb, L2TP_ATTR_RX_COOKIE_DISCARDS,
783 atomic_long_read(&session->stats.rx_cookie_discards),
784 L2TP_ATTR_STATS_PAD) ||
785 nla_put_u64_64bit(skb, L2TP_ATTR_RX_OOS_PACKETS,
786 atomic_long_read(&session->stats.rx_oos_packets),
787 L2TP_ATTR_STATS_PAD) ||
788 nla_put_u64_64bit(skb, L2TP_ATTR_RX_ERRORS,
789 atomic_long_read(&session->stats.rx_errors),
790 L2TP_ATTR_STATS_PAD) ||
791 nla_put_u64_64bit(skb, L2TP_ATTR_RX_INVALID,
792 atomic_long_read(&session->stats.rx_invalid),
793 L2TP_ATTR_STATS_PAD))
794 goto nla_put_failure;
795 nla_nest_end(skb, nest);
796
797 genlmsg_end(skb, hdr);
798 return 0;
799
800 nla_put_failure:
801 genlmsg_cancel(skb, hdr);
802 return -1;
803 }
804
l2tp_nl_cmd_session_get(struct sk_buff * skb,struct genl_info * info)805 static int l2tp_nl_cmd_session_get(struct sk_buff *skb, struct genl_info *info)
806 {
807 struct l2tp_session *session;
808 struct sk_buff *msg;
809 int ret;
810
811 session = l2tp_nl_session_get(info);
812 if (!session) {
813 ret = -ENODEV;
814 goto err;
815 }
816
817 msg = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);
818 if (!msg) {
819 ret = -ENOMEM;
820 goto err_ref;
821 }
822
823 ret = l2tp_nl_session_send(msg, info->snd_portid, info->snd_seq,
824 0, session, L2TP_CMD_SESSION_GET);
825 if (ret < 0)
826 goto err_ref_msg;
827
828 ret = genlmsg_unicast(genl_info_net(info), msg, info->snd_portid);
829
830 l2tp_session_put(session);
831
832 return ret;
833
834 err_ref_msg:
835 nlmsg_free(msg);
836 err_ref:
837 l2tp_session_put(session);
838 err:
839 return ret;
840 }
841
l2tp_nl_cmd_session_dump(struct sk_buff * skb,struct netlink_callback * cb)842 static int l2tp_nl_cmd_session_dump(struct sk_buff *skb, struct netlink_callback *cb)
843 {
844 struct l2tp_nl_cb_data *cbd = (void *)&cb->ctx[0];
845 struct net *net = sock_net(skb->sk);
846 struct l2tp_session *session;
847 struct l2tp_tunnel *tunnel = NULL;
848 unsigned long tkey = cbd->tkey;
849 unsigned long skey = cbd->skey;
850
851 for (;;) {
852 if (!tunnel) {
853 tunnel = l2tp_tunnel_get_next(net, &tkey);
854 if (!tunnel)
855 goto out;
856 }
857
858 session = l2tp_session_get_next(net, tunnel->sock, tunnel->version,
859 tunnel->tunnel_id, &skey);
860 if (!session) {
861 tkey++;
862 l2tp_tunnel_put(tunnel);
863 tunnel = NULL;
864 skey = 0;
865 continue;
866 }
867
868 if (l2tp_nl_session_send(skb, NETLINK_CB(cb->skb).portid,
869 cb->nlh->nlmsg_seq, NLM_F_MULTI,
870 session, L2TP_CMD_SESSION_GET) < 0) {
871 l2tp_session_put(session);
872 l2tp_tunnel_put(tunnel);
873 break;
874 }
875 l2tp_session_put(session);
876
877 skey++;
878 }
879
880 out:
881 cbd->tkey = tkey;
882 cbd->skey = skey;
883
884 return skb->len;
885 }
886
887 static const struct nla_policy l2tp_nl_policy[L2TP_ATTR_MAX + 1] = {
888 [L2TP_ATTR_NONE] = { .type = NLA_UNSPEC, },
889 [L2TP_ATTR_PW_TYPE] = { .type = NLA_U16, },
890 [L2TP_ATTR_ENCAP_TYPE] = { .type = NLA_U16, },
891 [L2TP_ATTR_OFFSET] = { .type = NLA_U16, },
892 [L2TP_ATTR_DATA_SEQ] = { .type = NLA_U8, },
893 [L2TP_ATTR_L2SPEC_TYPE] = { .type = NLA_U8, },
894 [L2TP_ATTR_L2SPEC_LEN] = { .type = NLA_U8, },
895 [L2TP_ATTR_PROTO_VERSION] = { .type = NLA_U8, },
896 [L2TP_ATTR_CONN_ID] = { .type = NLA_U32, },
897 [L2TP_ATTR_PEER_CONN_ID] = { .type = NLA_U32, },
898 [L2TP_ATTR_SESSION_ID] = { .type = NLA_U32, },
899 [L2TP_ATTR_PEER_SESSION_ID] = { .type = NLA_U32, },
900 [L2TP_ATTR_UDP_CSUM] = { .type = NLA_U8, },
901 [L2TP_ATTR_VLAN_ID] = { .type = NLA_U16, },
902 [L2TP_ATTR_DEBUG] = { .type = NLA_U32, },
903 [L2TP_ATTR_RECV_SEQ] = { .type = NLA_U8, },
904 [L2TP_ATTR_SEND_SEQ] = { .type = NLA_U8, },
905 [L2TP_ATTR_LNS_MODE] = { .type = NLA_U8, },
906 [L2TP_ATTR_USING_IPSEC] = { .type = NLA_U8, },
907 [L2TP_ATTR_RECV_TIMEOUT] = { .type = NLA_MSECS, },
908 [L2TP_ATTR_FD] = { .type = NLA_U32, },
909 [L2TP_ATTR_IP_SADDR] = { .type = NLA_U32, },
910 [L2TP_ATTR_IP_DADDR] = { .type = NLA_U32, },
911 [L2TP_ATTR_UDP_SPORT] = { .type = NLA_U16, },
912 [L2TP_ATTR_UDP_DPORT] = { .type = NLA_U16, },
913 [L2TP_ATTR_MTU] = { .type = NLA_U16, },
914 [L2TP_ATTR_MRU] = { .type = NLA_U16, },
915 [L2TP_ATTR_STATS] = { .type = NLA_NESTED, },
916 [L2TP_ATTR_IP6_SADDR] = {
917 .type = NLA_BINARY,
918 .len = sizeof(struct in6_addr),
919 },
920 [L2TP_ATTR_IP6_DADDR] = {
921 .type = NLA_BINARY,
922 .len = sizeof(struct in6_addr),
923 },
924 [L2TP_ATTR_IFNAME] = {
925 .type = NLA_NUL_STRING,
926 .len = IFNAMSIZ - 1,
927 },
928 [L2TP_ATTR_COOKIE] = {
929 .type = NLA_BINARY,
930 .len = 8,
931 },
932 [L2TP_ATTR_PEER_COOKIE] = {
933 .type = NLA_BINARY,
934 .len = 8,
935 },
936 };
937
938 static const struct genl_small_ops l2tp_nl_ops[] = {
939 {
940 .cmd = L2TP_CMD_NOOP,
941 .validate = GENL_DONT_VALIDATE_STRICT | GENL_DONT_VALIDATE_DUMP,
942 .doit = l2tp_nl_cmd_noop,
943 /* can be retrieved by unprivileged users */
944 },
945 {
946 .cmd = L2TP_CMD_TUNNEL_CREATE,
947 .validate = GENL_DONT_VALIDATE_STRICT | GENL_DONT_VALIDATE_DUMP,
948 .doit = l2tp_nl_cmd_tunnel_create,
949 .flags = GENL_UNS_ADMIN_PERM,
950 },
951 {
952 .cmd = L2TP_CMD_TUNNEL_DELETE,
953 .validate = GENL_DONT_VALIDATE_STRICT | GENL_DONT_VALIDATE_DUMP,
954 .doit = l2tp_nl_cmd_tunnel_delete,
955 .flags = GENL_UNS_ADMIN_PERM,
956 },
957 {
958 .cmd = L2TP_CMD_TUNNEL_MODIFY,
959 .validate = GENL_DONT_VALIDATE_STRICT | GENL_DONT_VALIDATE_DUMP,
960 .doit = l2tp_nl_cmd_tunnel_modify,
961 .flags = GENL_UNS_ADMIN_PERM,
962 },
963 {
964 .cmd = L2TP_CMD_TUNNEL_GET,
965 .validate = GENL_DONT_VALIDATE_STRICT | GENL_DONT_VALIDATE_DUMP,
966 .doit = l2tp_nl_cmd_tunnel_get,
967 .dumpit = l2tp_nl_cmd_tunnel_dump,
968 .flags = GENL_UNS_ADMIN_PERM,
969 },
970 {
971 .cmd = L2TP_CMD_SESSION_CREATE,
972 .validate = GENL_DONT_VALIDATE_STRICT | GENL_DONT_VALIDATE_DUMP,
973 .doit = l2tp_nl_cmd_session_create,
974 .flags = GENL_UNS_ADMIN_PERM,
975 },
976 {
977 .cmd = L2TP_CMD_SESSION_DELETE,
978 .validate = GENL_DONT_VALIDATE_STRICT | GENL_DONT_VALIDATE_DUMP,
979 .doit = l2tp_nl_cmd_session_delete,
980 .flags = GENL_UNS_ADMIN_PERM,
981 },
982 {
983 .cmd = L2TP_CMD_SESSION_MODIFY,
984 .validate = GENL_DONT_VALIDATE_STRICT | GENL_DONT_VALIDATE_DUMP,
985 .doit = l2tp_nl_cmd_session_modify,
986 .flags = GENL_UNS_ADMIN_PERM,
987 },
988 {
989 .cmd = L2TP_CMD_SESSION_GET,
990 .validate = GENL_DONT_VALIDATE_STRICT | GENL_DONT_VALIDATE_DUMP,
991 .doit = l2tp_nl_cmd_session_get,
992 .dumpit = l2tp_nl_cmd_session_dump,
993 .flags = GENL_UNS_ADMIN_PERM,
994 },
995 };
996
997 static struct genl_family l2tp_nl_family __ro_after_init = {
998 .name = L2TP_GENL_NAME,
999 .version = L2TP_GENL_VERSION,
1000 .hdrsize = 0,
1001 .maxattr = L2TP_ATTR_MAX,
1002 .policy = l2tp_nl_policy,
1003 .netnsok = true,
1004 .module = THIS_MODULE,
1005 .small_ops = l2tp_nl_ops,
1006 .n_small_ops = ARRAY_SIZE(l2tp_nl_ops),
1007 .resv_start_op = L2TP_CMD_SESSION_GET + 1,
1008 .mcgrps = l2tp_multicast_group,
1009 .n_mcgrps = ARRAY_SIZE(l2tp_multicast_group),
1010 };
1011
l2tp_nl_register_ops(enum l2tp_pwtype pw_type,const struct l2tp_nl_cmd_ops * ops)1012 int l2tp_nl_register_ops(enum l2tp_pwtype pw_type, const struct l2tp_nl_cmd_ops *ops)
1013 {
1014 int ret;
1015
1016 ret = -EINVAL;
1017 if (pw_type >= __L2TP_PWTYPE_MAX)
1018 goto err;
1019
1020 genl_lock();
1021 ret = -EBUSY;
1022 if (l2tp_nl_cmd_ops[pw_type])
1023 goto out;
1024
1025 l2tp_nl_cmd_ops[pw_type] = ops;
1026 ret = 0;
1027
1028 out:
1029 genl_unlock();
1030 err:
1031 return ret;
1032 }
1033 EXPORT_SYMBOL_GPL(l2tp_nl_register_ops);
1034
l2tp_nl_unregister_ops(enum l2tp_pwtype pw_type)1035 void l2tp_nl_unregister_ops(enum l2tp_pwtype pw_type)
1036 {
1037 if (pw_type < __L2TP_PWTYPE_MAX) {
1038 genl_lock();
1039 l2tp_nl_cmd_ops[pw_type] = NULL;
1040 genl_unlock();
1041 }
1042 }
1043 EXPORT_SYMBOL_GPL(l2tp_nl_unregister_ops);
1044
l2tp_nl_init(void)1045 static int __init l2tp_nl_init(void)
1046 {
1047 pr_info("L2TP netlink interface\n");
1048 return genl_register_family(&l2tp_nl_family);
1049 }
1050
l2tp_nl_cleanup(void)1051 static void l2tp_nl_cleanup(void)
1052 {
1053 genl_unregister_family(&l2tp_nl_family);
1054 }
1055
1056 module_init(l2tp_nl_init);
1057 module_exit(l2tp_nl_cleanup);
1058
1059 MODULE_AUTHOR("James Chapman <jchapman@katalix.com>");
1060 MODULE_DESCRIPTION("L2TP netlink");
1061 MODULE_LICENSE("GPL");
1062 MODULE_VERSION("1.0");
1063 MODULE_ALIAS_GENL_FAMILY("l2tp");
1064