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_tunnel_get_session(tunnel, session_id);
65 l2tp_tunnel_dec_refcount(tunnel);
66 }
67 }
68
69 return session;
70 }
71
l2tp_nl_cmd_noop(struct sk_buff * skb,struct genl_info * info)72 static int l2tp_nl_cmd_noop(struct sk_buff *skb, struct genl_info *info)
73 {
74 struct sk_buff *msg;
75 void *hdr;
76 int ret = -ENOBUFS;
77
78 msg = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);
79 if (!msg) {
80 ret = -ENOMEM;
81 goto out;
82 }
83
84 hdr = genlmsg_put(msg, info->snd_portid, info->snd_seq,
85 &l2tp_nl_family, 0, L2TP_CMD_NOOP);
86 if (!hdr) {
87 ret = -EMSGSIZE;
88 goto err_out;
89 }
90
91 genlmsg_end(msg, hdr);
92
93 return genlmsg_unicast(genl_info_net(info), msg, info->snd_portid);
94
95 err_out:
96 nlmsg_free(msg);
97
98 out:
99 return ret;
100 }
101
l2tp_tunnel_notify(struct genl_family * family,struct genl_info * info,struct l2tp_tunnel * tunnel,u8 cmd)102 static int l2tp_tunnel_notify(struct genl_family *family,
103 struct genl_info *info,
104 struct l2tp_tunnel *tunnel,
105 u8 cmd)
106 {
107 struct sk_buff *msg;
108 int ret;
109
110 msg = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);
111 if (!msg)
112 return -ENOMEM;
113
114 ret = l2tp_nl_tunnel_send(msg, info->snd_portid, info->snd_seq,
115 NLM_F_ACK, tunnel, cmd);
116
117 if (ret >= 0) {
118 ret = genlmsg_multicast_allns(family, msg, 0, 0);
119 /* We don't care if no one is listening */
120 if (ret == -ESRCH)
121 ret = 0;
122 return ret;
123 }
124
125 nlmsg_free(msg);
126
127 return ret;
128 }
129
l2tp_session_notify(struct genl_family * family,struct genl_info * info,struct l2tp_session * session,u8 cmd)130 static int l2tp_session_notify(struct genl_family *family,
131 struct genl_info *info,
132 struct l2tp_session *session,
133 u8 cmd)
134 {
135 struct sk_buff *msg;
136 int ret;
137
138 msg = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);
139 if (!msg)
140 return -ENOMEM;
141
142 ret = l2tp_nl_session_send(msg, info->snd_portid, info->snd_seq,
143 NLM_F_ACK, session, cmd);
144
145 if (ret >= 0) {
146 ret = genlmsg_multicast_allns(family, msg, 0, 0);
147 /* We don't care if no one is listening */
148 if (ret == -ESRCH)
149 ret = 0;
150 return ret;
151 }
152
153 nlmsg_free(msg);
154
155 return ret;
156 }
157
l2tp_nl_cmd_tunnel_create_get_addr(struct nlattr ** attrs,struct l2tp_tunnel_cfg * cfg)158 static int l2tp_nl_cmd_tunnel_create_get_addr(struct nlattr **attrs, struct l2tp_tunnel_cfg *cfg)
159 {
160 if (attrs[L2TP_ATTR_UDP_SPORT])
161 cfg->local_udp_port = nla_get_u16(attrs[L2TP_ATTR_UDP_SPORT]);
162 if (attrs[L2TP_ATTR_UDP_DPORT])
163 cfg->peer_udp_port = nla_get_u16(attrs[L2TP_ATTR_UDP_DPORT]);
164 cfg->use_udp_checksums = nla_get_flag(attrs[L2TP_ATTR_UDP_CSUM]);
165
166 /* Must have either AF_INET or AF_INET6 address for source and destination */
167 #if IS_ENABLED(CONFIG_IPV6)
168 if (attrs[L2TP_ATTR_IP6_SADDR] && attrs[L2TP_ATTR_IP6_DADDR]) {
169 cfg->local_ip6 = nla_data(attrs[L2TP_ATTR_IP6_SADDR]);
170 cfg->peer_ip6 = nla_data(attrs[L2TP_ATTR_IP6_DADDR]);
171 cfg->udp6_zero_tx_checksums = nla_get_flag(attrs[L2TP_ATTR_UDP_ZERO_CSUM6_TX]);
172 cfg->udp6_zero_rx_checksums = nla_get_flag(attrs[L2TP_ATTR_UDP_ZERO_CSUM6_RX]);
173 return 0;
174 }
175 #endif
176 if (attrs[L2TP_ATTR_IP_SADDR] && attrs[L2TP_ATTR_IP_DADDR]) {
177 cfg->local_ip.s_addr = nla_get_in_addr(attrs[L2TP_ATTR_IP_SADDR]);
178 cfg->peer_ip.s_addr = nla_get_in_addr(attrs[L2TP_ATTR_IP_DADDR]);
179 return 0;
180 }
181 return -EINVAL;
182 }
183
l2tp_nl_cmd_tunnel_create(struct sk_buff * skb,struct genl_info * info)184 static int l2tp_nl_cmd_tunnel_create(struct sk_buff *skb, struct genl_info *info)
185 {
186 u32 tunnel_id;
187 u32 peer_tunnel_id;
188 int proto_version;
189 int fd = -1;
190 int ret = 0;
191 struct l2tp_tunnel_cfg cfg = { 0, };
192 struct l2tp_tunnel *tunnel;
193 struct net *net = genl_info_net(info);
194 struct nlattr **attrs = info->attrs;
195
196 if (!attrs[L2TP_ATTR_CONN_ID]) {
197 ret = -EINVAL;
198 goto out;
199 }
200 tunnel_id = nla_get_u32(attrs[L2TP_ATTR_CONN_ID]);
201
202 if (!attrs[L2TP_ATTR_PEER_CONN_ID]) {
203 ret = -EINVAL;
204 goto out;
205 }
206 peer_tunnel_id = nla_get_u32(attrs[L2TP_ATTR_PEER_CONN_ID]);
207
208 if (!attrs[L2TP_ATTR_PROTO_VERSION]) {
209 ret = -EINVAL;
210 goto out;
211 }
212 proto_version = nla_get_u8(attrs[L2TP_ATTR_PROTO_VERSION]);
213
214 if (!attrs[L2TP_ATTR_ENCAP_TYPE]) {
215 ret = -EINVAL;
216 goto out;
217 }
218 cfg.encap = nla_get_u16(attrs[L2TP_ATTR_ENCAP_TYPE]);
219
220 /* Managed tunnels take the tunnel socket from userspace.
221 * Unmanaged tunnels must call out the source and destination addresses
222 * for the kernel to create the tunnel socket itself.
223 */
224 if (attrs[L2TP_ATTR_FD]) {
225 fd = nla_get_u32(attrs[L2TP_ATTR_FD]);
226 } else {
227 ret = l2tp_nl_cmd_tunnel_create_get_addr(attrs, &cfg);
228 if (ret < 0)
229 goto out;
230 }
231
232 ret = -EINVAL;
233 switch (cfg.encap) {
234 case L2TP_ENCAPTYPE_UDP:
235 case L2TP_ENCAPTYPE_IP:
236 ret = l2tp_tunnel_create(fd, proto_version, tunnel_id,
237 peer_tunnel_id, &cfg, &tunnel);
238 break;
239 }
240
241 if (ret < 0)
242 goto out;
243
244 l2tp_tunnel_inc_refcount(tunnel);
245 ret = l2tp_tunnel_register(tunnel, net, &cfg);
246 if (ret < 0) {
247 kfree(tunnel);
248 goto out;
249 }
250 ret = l2tp_tunnel_notify(&l2tp_nl_family, info, tunnel,
251 L2TP_CMD_TUNNEL_CREATE);
252 l2tp_tunnel_dec_refcount(tunnel);
253
254 out:
255 return ret;
256 }
257
l2tp_nl_cmd_tunnel_delete(struct sk_buff * skb,struct genl_info * info)258 static int l2tp_nl_cmd_tunnel_delete(struct sk_buff *skb, struct genl_info *info)
259 {
260 struct l2tp_tunnel *tunnel;
261 u32 tunnel_id;
262 int ret = 0;
263 struct net *net = genl_info_net(info);
264
265 if (!info->attrs[L2TP_ATTR_CONN_ID]) {
266 ret = -EINVAL;
267 goto out;
268 }
269 tunnel_id = nla_get_u32(info->attrs[L2TP_ATTR_CONN_ID]);
270
271 tunnel = l2tp_tunnel_get(net, tunnel_id);
272 if (!tunnel) {
273 ret = -ENODEV;
274 goto out;
275 }
276
277 l2tp_tunnel_notify(&l2tp_nl_family, info,
278 tunnel, L2TP_CMD_TUNNEL_DELETE);
279
280 l2tp_tunnel_delete(tunnel);
281
282 l2tp_tunnel_dec_refcount(tunnel);
283
284 out:
285 return ret;
286 }
287
l2tp_nl_cmd_tunnel_modify(struct sk_buff * skb,struct genl_info * info)288 static int l2tp_nl_cmd_tunnel_modify(struct sk_buff *skb, struct genl_info *info)
289 {
290 struct l2tp_tunnel *tunnel;
291 u32 tunnel_id;
292 int ret = 0;
293 struct net *net = genl_info_net(info);
294
295 if (!info->attrs[L2TP_ATTR_CONN_ID]) {
296 ret = -EINVAL;
297 goto out;
298 }
299 tunnel_id = nla_get_u32(info->attrs[L2TP_ATTR_CONN_ID]);
300
301 tunnel = l2tp_tunnel_get(net, tunnel_id);
302 if (!tunnel) {
303 ret = -ENODEV;
304 goto out;
305 }
306
307 ret = l2tp_tunnel_notify(&l2tp_nl_family, info,
308 tunnel, L2TP_CMD_TUNNEL_MODIFY);
309
310 l2tp_tunnel_dec_refcount(tunnel);
311
312 out:
313 return ret;
314 }
315
316 #if IS_ENABLED(CONFIG_IPV6)
l2tp_nl_tunnel_send_addr6(struct sk_buff * skb,struct sock * sk,enum l2tp_encap_type encap)317 static int l2tp_nl_tunnel_send_addr6(struct sk_buff *skb, struct sock *sk,
318 enum l2tp_encap_type encap)
319 {
320 struct inet_sock *inet = inet_sk(sk);
321 struct ipv6_pinfo *np = inet6_sk(sk);
322
323 switch (encap) {
324 case L2TP_ENCAPTYPE_UDP:
325 if (udp_get_no_check6_tx(sk) &&
326 nla_put_flag(skb, L2TP_ATTR_UDP_ZERO_CSUM6_TX))
327 return -1;
328 if (udp_get_no_check6_rx(sk) &&
329 nla_put_flag(skb, L2TP_ATTR_UDP_ZERO_CSUM6_RX))
330 return -1;
331 if (nla_put_u16(skb, L2TP_ATTR_UDP_SPORT, ntohs(inet->inet_sport)) ||
332 nla_put_u16(skb, L2TP_ATTR_UDP_DPORT, ntohs(inet->inet_dport)))
333 return -1;
334 fallthrough;
335 case L2TP_ENCAPTYPE_IP:
336 if (nla_put_in6_addr(skb, L2TP_ATTR_IP6_SADDR, &np->saddr) ||
337 nla_put_in6_addr(skb, L2TP_ATTR_IP6_DADDR, &sk->sk_v6_daddr))
338 return -1;
339 break;
340 }
341 return 0;
342 }
343 #endif
344
l2tp_nl_tunnel_send_addr4(struct sk_buff * skb,struct sock * sk,enum l2tp_encap_type encap)345 static int l2tp_nl_tunnel_send_addr4(struct sk_buff *skb, struct sock *sk,
346 enum l2tp_encap_type encap)
347 {
348 struct inet_sock *inet = inet_sk(sk);
349
350 switch (encap) {
351 case L2TP_ENCAPTYPE_UDP:
352 if (nla_put_u8(skb, L2TP_ATTR_UDP_CSUM, !sk->sk_no_check_tx) ||
353 nla_put_u16(skb, L2TP_ATTR_UDP_SPORT, ntohs(inet->inet_sport)) ||
354 nla_put_u16(skb, L2TP_ATTR_UDP_DPORT, ntohs(inet->inet_dport)))
355 return -1;
356 fallthrough;
357 case L2TP_ENCAPTYPE_IP:
358 if (nla_put_in_addr(skb, L2TP_ATTR_IP_SADDR, inet->inet_saddr) ||
359 nla_put_in_addr(skb, L2TP_ATTR_IP_DADDR, inet->inet_daddr))
360 return -1;
361 break;
362 }
363
364 return 0;
365 }
366
367 /* Append attributes for the tunnel address, handling the different attribute types
368 * used for different tunnel encapsulation and AF_INET v.s. AF_INET6.
369 */
l2tp_nl_tunnel_send_addr(struct sk_buff * skb,struct l2tp_tunnel * tunnel)370 static int l2tp_nl_tunnel_send_addr(struct sk_buff *skb, struct l2tp_tunnel *tunnel)
371 {
372 struct sock *sk = tunnel->sock;
373
374 if (!sk)
375 return 0;
376
377 #if IS_ENABLED(CONFIG_IPV6)
378 if (sk->sk_family == AF_INET6)
379 return l2tp_nl_tunnel_send_addr6(skb, sk, tunnel->encap);
380 #endif
381 return l2tp_nl_tunnel_send_addr4(skb, sk, tunnel->encap);
382 }
383
l2tp_nl_tunnel_send(struct sk_buff * skb,u32 portid,u32 seq,int flags,struct l2tp_tunnel * tunnel,u8 cmd)384 static int l2tp_nl_tunnel_send(struct sk_buff *skb, u32 portid, u32 seq, int flags,
385 struct l2tp_tunnel *tunnel, u8 cmd)
386 {
387 void *hdr;
388 struct nlattr *nest;
389
390 hdr = genlmsg_put(skb, portid, seq, &l2tp_nl_family, flags, cmd);
391 if (!hdr)
392 return -EMSGSIZE;
393
394 if (nla_put_u8(skb, L2TP_ATTR_PROTO_VERSION, tunnel->version) ||
395 nla_put_u32(skb, L2TP_ATTR_CONN_ID, tunnel->tunnel_id) ||
396 nla_put_u32(skb, L2TP_ATTR_PEER_CONN_ID, tunnel->peer_tunnel_id) ||
397 nla_put_u32(skb, L2TP_ATTR_DEBUG, 0) ||
398 nla_put_u16(skb, L2TP_ATTR_ENCAP_TYPE, tunnel->encap))
399 goto nla_put_failure;
400
401 nest = nla_nest_start_noflag(skb, L2TP_ATTR_STATS);
402 if (!nest)
403 goto nla_put_failure;
404
405 if (nla_put_u64_64bit(skb, L2TP_ATTR_TX_PACKETS,
406 atomic_long_read(&tunnel->stats.tx_packets),
407 L2TP_ATTR_STATS_PAD) ||
408 nla_put_u64_64bit(skb, L2TP_ATTR_TX_BYTES,
409 atomic_long_read(&tunnel->stats.tx_bytes),
410 L2TP_ATTR_STATS_PAD) ||
411 nla_put_u64_64bit(skb, L2TP_ATTR_TX_ERRORS,
412 atomic_long_read(&tunnel->stats.tx_errors),
413 L2TP_ATTR_STATS_PAD) ||
414 nla_put_u64_64bit(skb, L2TP_ATTR_RX_PACKETS,
415 atomic_long_read(&tunnel->stats.rx_packets),
416 L2TP_ATTR_STATS_PAD) ||
417 nla_put_u64_64bit(skb, L2TP_ATTR_RX_BYTES,
418 atomic_long_read(&tunnel->stats.rx_bytes),
419 L2TP_ATTR_STATS_PAD) ||
420 nla_put_u64_64bit(skb, L2TP_ATTR_RX_SEQ_DISCARDS,
421 atomic_long_read(&tunnel->stats.rx_seq_discards),
422 L2TP_ATTR_STATS_PAD) ||
423 nla_put_u64_64bit(skb, L2TP_ATTR_RX_COOKIE_DISCARDS,
424 atomic_long_read(&tunnel->stats.rx_cookie_discards),
425 L2TP_ATTR_STATS_PAD) ||
426 nla_put_u64_64bit(skb, L2TP_ATTR_RX_OOS_PACKETS,
427 atomic_long_read(&tunnel->stats.rx_oos_packets),
428 L2TP_ATTR_STATS_PAD) ||
429 nla_put_u64_64bit(skb, L2TP_ATTR_RX_ERRORS,
430 atomic_long_read(&tunnel->stats.rx_errors),
431 L2TP_ATTR_STATS_PAD) ||
432 nla_put_u64_64bit(skb, L2TP_ATTR_RX_INVALID,
433 atomic_long_read(&tunnel->stats.rx_invalid),
434 L2TP_ATTR_STATS_PAD))
435 goto nla_put_failure;
436 nla_nest_end(skb, nest);
437
438 if (l2tp_nl_tunnel_send_addr(skb, tunnel))
439 goto nla_put_failure;
440
441 genlmsg_end(skb, hdr);
442 return 0;
443
444 nla_put_failure:
445 genlmsg_cancel(skb, hdr);
446 return -1;
447 }
448
l2tp_nl_cmd_tunnel_get(struct sk_buff * skb,struct genl_info * info)449 static int l2tp_nl_cmd_tunnel_get(struct sk_buff *skb, struct genl_info *info)
450 {
451 struct l2tp_tunnel *tunnel;
452 struct sk_buff *msg;
453 u32 tunnel_id;
454 int ret = -ENOBUFS;
455 struct net *net = genl_info_net(info);
456
457 if (!info->attrs[L2TP_ATTR_CONN_ID]) {
458 ret = -EINVAL;
459 goto err;
460 }
461
462 tunnel_id = nla_get_u32(info->attrs[L2TP_ATTR_CONN_ID]);
463
464 msg = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);
465 if (!msg) {
466 ret = -ENOMEM;
467 goto err;
468 }
469
470 tunnel = l2tp_tunnel_get(net, tunnel_id);
471 if (!tunnel) {
472 ret = -ENODEV;
473 goto err_nlmsg;
474 }
475
476 ret = l2tp_nl_tunnel_send(msg, info->snd_portid, info->snd_seq,
477 NLM_F_ACK, tunnel, L2TP_CMD_TUNNEL_GET);
478 if (ret < 0)
479 goto err_nlmsg_tunnel;
480
481 l2tp_tunnel_dec_refcount(tunnel);
482
483 return genlmsg_unicast(net, msg, info->snd_portid);
484
485 err_nlmsg_tunnel:
486 l2tp_tunnel_dec_refcount(tunnel);
487 err_nlmsg:
488 nlmsg_free(msg);
489 err:
490 return ret;
491 }
492
l2tp_nl_cmd_tunnel_dump(struct sk_buff * skb,struct netlink_callback * cb)493 static int l2tp_nl_cmd_tunnel_dump(struct sk_buff *skb, struct netlink_callback *cb)
494 {
495 int ti = cb->args[0];
496 struct l2tp_tunnel *tunnel;
497 struct net *net = sock_net(skb->sk);
498
499 for (;;) {
500 tunnel = l2tp_tunnel_get_nth(net, ti);
501 if (!tunnel)
502 goto out;
503
504 if (l2tp_nl_tunnel_send(skb, NETLINK_CB(cb->skb).portid,
505 cb->nlh->nlmsg_seq, NLM_F_MULTI,
506 tunnel, L2TP_CMD_TUNNEL_GET) < 0) {
507 l2tp_tunnel_dec_refcount(tunnel);
508 goto out;
509 }
510 l2tp_tunnel_dec_refcount(tunnel);
511
512 ti++;
513 }
514
515 out:
516 cb->args[0] = ti;
517
518 return skb->len;
519 }
520
l2tp_nl_cmd_session_create(struct sk_buff * skb,struct genl_info * info)521 static int l2tp_nl_cmd_session_create(struct sk_buff *skb, struct genl_info *info)
522 {
523 u32 tunnel_id = 0;
524 u32 session_id;
525 u32 peer_session_id;
526 int ret = 0;
527 struct l2tp_tunnel *tunnel;
528 struct l2tp_session *session;
529 struct l2tp_session_cfg cfg = { 0, };
530 struct net *net = genl_info_net(info);
531
532 if (!info->attrs[L2TP_ATTR_CONN_ID]) {
533 ret = -EINVAL;
534 goto out;
535 }
536
537 tunnel_id = nla_get_u32(info->attrs[L2TP_ATTR_CONN_ID]);
538 tunnel = l2tp_tunnel_get(net, tunnel_id);
539 if (!tunnel) {
540 ret = -ENODEV;
541 goto out;
542 }
543
544 if (!info->attrs[L2TP_ATTR_SESSION_ID]) {
545 ret = -EINVAL;
546 goto out_tunnel;
547 }
548 session_id = nla_get_u32(info->attrs[L2TP_ATTR_SESSION_ID]);
549
550 if (!info->attrs[L2TP_ATTR_PEER_SESSION_ID]) {
551 ret = -EINVAL;
552 goto out_tunnel;
553 }
554 peer_session_id = nla_get_u32(info->attrs[L2TP_ATTR_PEER_SESSION_ID]);
555
556 if (!info->attrs[L2TP_ATTR_PW_TYPE]) {
557 ret = -EINVAL;
558 goto out_tunnel;
559 }
560 cfg.pw_type = nla_get_u16(info->attrs[L2TP_ATTR_PW_TYPE]);
561 if (cfg.pw_type >= __L2TP_PWTYPE_MAX) {
562 ret = -EINVAL;
563 goto out_tunnel;
564 }
565
566 /* L2TPv2 only accepts PPP pseudo-wires */
567 if (tunnel->version == 2 && cfg.pw_type != L2TP_PWTYPE_PPP) {
568 ret = -EPROTONOSUPPORT;
569 goto out_tunnel;
570 }
571
572 if (tunnel->version > 2) {
573 if (info->attrs[L2TP_ATTR_L2SPEC_TYPE]) {
574 cfg.l2specific_type = nla_get_u8(info->attrs[L2TP_ATTR_L2SPEC_TYPE]);
575 if (cfg.l2specific_type != L2TP_L2SPECTYPE_DEFAULT &&
576 cfg.l2specific_type != L2TP_L2SPECTYPE_NONE) {
577 ret = -EINVAL;
578 goto out_tunnel;
579 }
580 } else {
581 cfg.l2specific_type = L2TP_L2SPECTYPE_DEFAULT;
582 }
583
584 if (info->attrs[L2TP_ATTR_COOKIE]) {
585 u16 len = nla_len(info->attrs[L2TP_ATTR_COOKIE]);
586
587 if (len > 8) {
588 ret = -EINVAL;
589 goto out_tunnel;
590 }
591 cfg.cookie_len = len;
592 memcpy(&cfg.cookie[0], nla_data(info->attrs[L2TP_ATTR_COOKIE]), len);
593 }
594 if (info->attrs[L2TP_ATTR_PEER_COOKIE]) {
595 u16 len = nla_len(info->attrs[L2TP_ATTR_PEER_COOKIE]);
596
597 if (len > 8) {
598 ret = -EINVAL;
599 goto out_tunnel;
600 }
601 cfg.peer_cookie_len = len;
602 memcpy(&cfg.peer_cookie[0], nla_data(info->attrs[L2TP_ATTR_PEER_COOKIE]), len);
603 }
604 if (info->attrs[L2TP_ATTR_IFNAME])
605 cfg.ifname = nla_data(info->attrs[L2TP_ATTR_IFNAME]);
606 }
607
608 if (info->attrs[L2TP_ATTR_RECV_SEQ])
609 cfg.recv_seq = nla_get_u8(info->attrs[L2TP_ATTR_RECV_SEQ]);
610
611 if (info->attrs[L2TP_ATTR_SEND_SEQ])
612 cfg.send_seq = nla_get_u8(info->attrs[L2TP_ATTR_SEND_SEQ]);
613
614 if (info->attrs[L2TP_ATTR_LNS_MODE])
615 cfg.lns_mode = nla_get_u8(info->attrs[L2TP_ATTR_LNS_MODE]);
616
617 if (info->attrs[L2TP_ATTR_RECV_TIMEOUT])
618 cfg.reorder_timeout = nla_get_msecs(info->attrs[L2TP_ATTR_RECV_TIMEOUT]);
619
620 #ifdef CONFIG_MODULES
621 if (!l2tp_nl_cmd_ops[cfg.pw_type]) {
622 genl_unlock();
623 request_module("net-l2tp-type-%u", cfg.pw_type);
624 genl_lock();
625 }
626 #endif
627 if (!l2tp_nl_cmd_ops[cfg.pw_type] || !l2tp_nl_cmd_ops[cfg.pw_type]->session_create) {
628 ret = -EPROTONOSUPPORT;
629 goto out_tunnel;
630 }
631
632 ret = l2tp_nl_cmd_ops[cfg.pw_type]->session_create(net, tunnel,
633 session_id,
634 peer_session_id,
635 &cfg);
636
637 if (ret >= 0) {
638 session = l2tp_tunnel_get_session(tunnel, session_id);
639 if (session) {
640 ret = l2tp_session_notify(&l2tp_nl_family, info, session,
641 L2TP_CMD_SESSION_CREATE);
642 l2tp_session_dec_refcount(session);
643 }
644 }
645
646 out_tunnel:
647 l2tp_tunnel_dec_refcount(tunnel);
648 out:
649 return ret;
650 }
651
l2tp_nl_cmd_session_delete(struct sk_buff * skb,struct genl_info * info)652 static int l2tp_nl_cmd_session_delete(struct sk_buff *skb, struct genl_info *info)
653 {
654 int ret = 0;
655 struct l2tp_session *session;
656 u16 pw_type;
657
658 session = l2tp_nl_session_get(info);
659 if (!session) {
660 ret = -ENODEV;
661 goto out;
662 }
663
664 l2tp_session_notify(&l2tp_nl_family, info,
665 session, L2TP_CMD_SESSION_DELETE);
666
667 pw_type = session->pwtype;
668 if (pw_type < __L2TP_PWTYPE_MAX)
669 if (l2tp_nl_cmd_ops[pw_type] && l2tp_nl_cmd_ops[pw_type]->session_delete)
670 l2tp_nl_cmd_ops[pw_type]->session_delete(session);
671
672 l2tp_session_dec_refcount(session);
673
674 out:
675 return ret;
676 }
677
l2tp_nl_cmd_session_modify(struct sk_buff * skb,struct genl_info * info)678 static int l2tp_nl_cmd_session_modify(struct sk_buff *skb, struct genl_info *info)
679 {
680 int ret = 0;
681 struct l2tp_session *session;
682
683 session = l2tp_nl_session_get(info);
684 if (!session) {
685 ret = -ENODEV;
686 goto out;
687 }
688
689 if (info->attrs[L2TP_ATTR_RECV_SEQ])
690 session->recv_seq = nla_get_u8(info->attrs[L2TP_ATTR_RECV_SEQ]);
691
692 if (info->attrs[L2TP_ATTR_SEND_SEQ]) {
693 struct l2tp_tunnel *tunnel = session->tunnel;
694
695 session->send_seq = nla_get_u8(info->attrs[L2TP_ATTR_SEND_SEQ]);
696 l2tp_session_set_header_len(session, tunnel->version, tunnel->encap);
697 }
698
699 if (info->attrs[L2TP_ATTR_LNS_MODE])
700 session->lns_mode = nla_get_u8(info->attrs[L2TP_ATTR_LNS_MODE]);
701
702 if (info->attrs[L2TP_ATTR_RECV_TIMEOUT])
703 session->reorder_timeout = nla_get_msecs(info->attrs[L2TP_ATTR_RECV_TIMEOUT]);
704
705 ret = l2tp_session_notify(&l2tp_nl_family, info,
706 session, L2TP_CMD_SESSION_MODIFY);
707
708 l2tp_session_dec_refcount(session);
709
710 out:
711 return ret;
712 }
713
l2tp_nl_session_send(struct sk_buff * skb,u32 portid,u32 seq,int flags,struct l2tp_session * session,u8 cmd)714 static int l2tp_nl_session_send(struct sk_buff *skb, u32 portid, u32 seq, int flags,
715 struct l2tp_session *session, u8 cmd)
716 {
717 void *hdr;
718 struct nlattr *nest;
719 struct l2tp_tunnel *tunnel = session->tunnel;
720
721 hdr = genlmsg_put(skb, portid, seq, &l2tp_nl_family, flags, cmd);
722 if (!hdr)
723 return -EMSGSIZE;
724
725 if (nla_put_u32(skb, L2TP_ATTR_CONN_ID, tunnel->tunnel_id) ||
726 nla_put_u32(skb, L2TP_ATTR_SESSION_ID, session->session_id) ||
727 nla_put_u32(skb, L2TP_ATTR_PEER_CONN_ID, tunnel->peer_tunnel_id) ||
728 nla_put_u32(skb, L2TP_ATTR_PEER_SESSION_ID, session->peer_session_id) ||
729 nla_put_u32(skb, L2TP_ATTR_DEBUG, 0) ||
730 nla_put_u16(skb, L2TP_ATTR_PW_TYPE, session->pwtype))
731 goto nla_put_failure;
732
733 if ((session->ifname[0] &&
734 nla_put_string(skb, L2TP_ATTR_IFNAME, session->ifname)) ||
735 (session->cookie_len &&
736 nla_put(skb, L2TP_ATTR_COOKIE, session->cookie_len, session->cookie)) ||
737 (session->peer_cookie_len &&
738 nla_put(skb, L2TP_ATTR_PEER_COOKIE, session->peer_cookie_len, session->peer_cookie)) ||
739 nla_put_u8(skb, L2TP_ATTR_RECV_SEQ, session->recv_seq) ||
740 nla_put_u8(skb, L2TP_ATTR_SEND_SEQ, session->send_seq) ||
741 nla_put_u8(skb, L2TP_ATTR_LNS_MODE, session->lns_mode) ||
742 (l2tp_tunnel_uses_xfrm(tunnel) &&
743 nla_put_u8(skb, L2TP_ATTR_USING_IPSEC, 1)) ||
744 (session->reorder_timeout &&
745 nla_put_msecs(skb, L2TP_ATTR_RECV_TIMEOUT,
746 session->reorder_timeout, L2TP_ATTR_PAD)))
747 goto nla_put_failure;
748
749 nest = nla_nest_start_noflag(skb, L2TP_ATTR_STATS);
750 if (!nest)
751 goto nla_put_failure;
752
753 if (nla_put_u64_64bit(skb, L2TP_ATTR_TX_PACKETS,
754 atomic_long_read(&session->stats.tx_packets),
755 L2TP_ATTR_STATS_PAD) ||
756 nla_put_u64_64bit(skb, L2TP_ATTR_TX_BYTES,
757 atomic_long_read(&session->stats.tx_bytes),
758 L2TP_ATTR_STATS_PAD) ||
759 nla_put_u64_64bit(skb, L2TP_ATTR_TX_ERRORS,
760 atomic_long_read(&session->stats.tx_errors),
761 L2TP_ATTR_STATS_PAD) ||
762 nla_put_u64_64bit(skb, L2TP_ATTR_RX_PACKETS,
763 atomic_long_read(&session->stats.rx_packets),
764 L2TP_ATTR_STATS_PAD) ||
765 nla_put_u64_64bit(skb, L2TP_ATTR_RX_BYTES,
766 atomic_long_read(&session->stats.rx_bytes),
767 L2TP_ATTR_STATS_PAD) ||
768 nla_put_u64_64bit(skb, L2TP_ATTR_RX_SEQ_DISCARDS,
769 atomic_long_read(&session->stats.rx_seq_discards),
770 L2TP_ATTR_STATS_PAD) ||
771 nla_put_u64_64bit(skb, L2TP_ATTR_RX_COOKIE_DISCARDS,
772 atomic_long_read(&session->stats.rx_cookie_discards),
773 L2TP_ATTR_STATS_PAD) ||
774 nla_put_u64_64bit(skb, L2TP_ATTR_RX_OOS_PACKETS,
775 atomic_long_read(&session->stats.rx_oos_packets),
776 L2TP_ATTR_STATS_PAD) ||
777 nla_put_u64_64bit(skb, L2TP_ATTR_RX_ERRORS,
778 atomic_long_read(&session->stats.rx_errors),
779 L2TP_ATTR_STATS_PAD) ||
780 nla_put_u64_64bit(skb, L2TP_ATTR_RX_INVALID,
781 atomic_long_read(&session->stats.rx_invalid),
782 L2TP_ATTR_STATS_PAD))
783 goto nla_put_failure;
784 nla_nest_end(skb, nest);
785
786 genlmsg_end(skb, hdr);
787 return 0;
788
789 nla_put_failure:
790 genlmsg_cancel(skb, hdr);
791 return -1;
792 }
793
l2tp_nl_cmd_session_get(struct sk_buff * skb,struct genl_info * info)794 static int l2tp_nl_cmd_session_get(struct sk_buff *skb, struct genl_info *info)
795 {
796 struct l2tp_session *session;
797 struct sk_buff *msg;
798 int ret;
799
800 session = l2tp_nl_session_get(info);
801 if (!session) {
802 ret = -ENODEV;
803 goto err;
804 }
805
806 msg = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);
807 if (!msg) {
808 ret = -ENOMEM;
809 goto err_ref;
810 }
811
812 ret = l2tp_nl_session_send(msg, info->snd_portid, info->snd_seq,
813 0, session, L2TP_CMD_SESSION_GET);
814 if (ret < 0)
815 goto err_ref_msg;
816
817 ret = genlmsg_unicast(genl_info_net(info), msg, info->snd_portid);
818
819 l2tp_session_dec_refcount(session);
820
821 return ret;
822
823 err_ref_msg:
824 nlmsg_free(msg);
825 err_ref:
826 l2tp_session_dec_refcount(session);
827 err:
828 return ret;
829 }
830
l2tp_nl_cmd_session_dump(struct sk_buff * skb,struct netlink_callback * cb)831 static int l2tp_nl_cmd_session_dump(struct sk_buff *skb, struct netlink_callback *cb)
832 {
833 struct net *net = sock_net(skb->sk);
834 struct l2tp_session *session;
835 struct l2tp_tunnel *tunnel = NULL;
836 int ti = cb->args[0];
837 int si = cb->args[1];
838
839 for (;;) {
840 if (!tunnel) {
841 tunnel = l2tp_tunnel_get_nth(net, ti);
842 if (!tunnel)
843 goto out;
844 }
845
846 session = l2tp_session_get_nth(tunnel, si);
847 if (!session) {
848 ti++;
849 l2tp_tunnel_dec_refcount(tunnel);
850 tunnel = NULL;
851 si = 0;
852 continue;
853 }
854
855 if (l2tp_nl_session_send(skb, NETLINK_CB(cb->skb).portid,
856 cb->nlh->nlmsg_seq, NLM_F_MULTI,
857 session, L2TP_CMD_SESSION_GET) < 0) {
858 l2tp_session_dec_refcount(session);
859 l2tp_tunnel_dec_refcount(tunnel);
860 break;
861 }
862 l2tp_session_dec_refcount(session);
863
864 si++;
865 }
866
867 out:
868 cb->args[0] = ti;
869 cb->args[1] = si;
870
871 return skb->len;
872 }
873
874 static const struct nla_policy l2tp_nl_policy[L2TP_ATTR_MAX + 1] = {
875 [L2TP_ATTR_NONE] = { .type = NLA_UNSPEC, },
876 [L2TP_ATTR_PW_TYPE] = { .type = NLA_U16, },
877 [L2TP_ATTR_ENCAP_TYPE] = { .type = NLA_U16, },
878 [L2TP_ATTR_OFFSET] = { .type = NLA_U16, },
879 [L2TP_ATTR_DATA_SEQ] = { .type = NLA_U8, },
880 [L2TP_ATTR_L2SPEC_TYPE] = { .type = NLA_U8, },
881 [L2TP_ATTR_L2SPEC_LEN] = { .type = NLA_U8, },
882 [L2TP_ATTR_PROTO_VERSION] = { .type = NLA_U8, },
883 [L2TP_ATTR_CONN_ID] = { .type = NLA_U32, },
884 [L2TP_ATTR_PEER_CONN_ID] = { .type = NLA_U32, },
885 [L2TP_ATTR_SESSION_ID] = { .type = NLA_U32, },
886 [L2TP_ATTR_PEER_SESSION_ID] = { .type = NLA_U32, },
887 [L2TP_ATTR_UDP_CSUM] = { .type = NLA_U8, },
888 [L2TP_ATTR_VLAN_ID] = { .type = NLA_U16, },
889 [L2TP_ATTR_DEBUG] = { .type = NLA_U32, },
890 [L2TP_ATTR_RECV_SEQ] = { .type = NLA_U8, },
891 [L2TP_ATTR_SEND_SEQ] = { .type = NLA_U8, },
892 [L2TP_ATTR_LNS_MODE] = { .type = NLA_U8, },
893 [L2TP_ATTR_USING_IPSEC] = { .type = NLA_U8, },
894 [L2TP_ATTR_RECV_TIMEOUT] = { .type = NLA_MSECS, },
895 [L2TP_ATTR_FD] = { .type = NLA_U32, },
896 [L2TP_ATTR_IP_SADDR] = { .type = NLA_U32, },
897 [L2TP_ATTR_IP_DADDR] = { .type = NLA_U32, },
898 [L2TP_ATTR_UDP_SPORT] = { .type = NLA_U16, },
899 [L2TP_ATTR_UDP_DPORT] = { .type = NLA_U16, },
900 [L2TP_ATTR_MTU] = { .type = NLA_U16, },
901 [L2TP_ATTR_MRU] = { .type = NLA_U16, },
902 [L2TP_ATTR_STATS] = { .type = NLA_NESTED, },
903 [L2TP_ATTR_IP6_SADDR] = {
904 .type = NLA_BINARY,
905 .len = sizeof(struct in6_addr),
906 },
907 [L2TP_ATTR_IP6_DADDR] = {
908 .type = NLA_BINARY,
909 .len = sizeof(struct in6_addr),
910 },
911 [L2TP_ATTR_IFNAME] = {
912 .type = NLA_NUL_STRING,
913 .len = IFNAMSIZ - 1,
914 },
915 [L2TP_ATTR_COOKIE] = {
916 .type = NLA_BINARY,
917 .len = 8,
918 },
919 [L2TP_ATTR_PEER_COOKIE] = {
920 .type = NLA_BINARY,
921 .len = 8,
922 },
923 };
924
925 static const struct genl_small_ops l2tp_nl_ops[] = {
926 {
927 .cmd = L2TP_CMD_NOOP,
928 .validate = GENL_DONT_VALIDATE_STRICT | GENL_DONT_VALIDATE_DUMP,
929 .doit = l2tp_nl_cmd_noop,
930 /* can be retrieved by unprivileged users */
931 },
932 {
933 .cmd = L2TP_CMD_TUNNEL_CREATE,
934 .validate = GENL_DONT_VALIDATE_STRICT | GENL_DONT_VALIDATE_DUMP,
935 .doit = l2tp_nl_cmd_tunnel_create,
936 .flags = GENL_UNS_ADMIN_PERM,
937 },
938 {
939 .cmd = L2TP_CMD_TUNNEL_DELETE,
940 .validate = GENL_DONT_VALIDATE_STRICT | GENL_DONT_VALIDATE_DUMP,
941 .doit = l2tp_nl_cmd_tunnel_delete,
942 .flags = GENL_UNS_ADMIN_PERM,
943 },
944 {
945 .cmd = L2TP_CMD_TUNNEL_MODIFY,
946 .validate = GENL_DONT_VALIDATE_STRICT | GENL_DONT_VALIDATE_DUMP,
947 .doit = l2tp_nl_cmd_tunnel_modify,
948 .flags = GENL_UNS_ADMIN_PERM,
949 },
950 {
951 .cmd = L2TP_CMD_TUNNEL_GET,
952 .validate = GENL_DONT_VALIDATE_STRICT | GENL_DONT_VALIDATE_DUMP,
953 .doit = l2tp_nl_cmd_tunnel_get,
954 .dumpit = l2tp_nl_cmd_tunnel_dump,
955 .flags = GENL_UNS_ADMIN_PERM,
956 },
957 {
958 .cmd = L2TP_CMD_SESSION_CREATE,
959 .validate = GENL_DONT_VALIDATE_STRICT | GENL_DONT_VALIDATE_DUMP,
960 .doit = l2tp_nl_cmd_session_create,
961 .flags = GENL_UNS_ADMIN_PERM,
962 },
963 {
964 .cmd = L2TP_CMD_SESSION_DELETE,
965 .validate = GENL_DONT_VALIDATE_STRICT | GENL_DONT_VALIDATE_DUMP,
966 .doit = l2tp_nl_cmd_session_delete,
967 .flags = GENL_UNS_ADMIN_PERM,
968 },
969 {
970 .cmd = L2TP_CMD_SESSION_MODIFY,
971 .validate = GENL_DONT_VALIDATE_STRICT | GENL_DONT_VALIDATE_DUMP,
972 .doit = l2tp_nl_cmd_session_modify,
973 .flags = GENL_UNS_ADMIN_PERM,
974 },
975 {
976 .cmd = L2TP_CMD_SESSION_GET,
977 .validate = GENL_DONT_VALIDATE_STRICT | GENL_DONT_VALIDATE_DUMP,
978 .doit = l2tp_nl_cmd_session_get,
979 .dumpit = l2tp_nl_cmd_session_dump,
980 .flags = GENL_UNS_ADMIN_PERM,
981 },
982 };
983
984 static struct genl_family l2tp_nl_family __ro_after_init = {
985 .name = L2TP_GENL_NAME,
986 .version = L2TP_GENL_VERSION,
987 .hdrsize = 0,
988 .maxattr = L2TP_ATTR_MAX,
989 .policy = l2tp_nl_policy,
990 .netnsok = true,
991 .module = THIS_MODULE,
992 .small_ops = l2tp_nl_ops,
993 .n_small_ops = ARRAY_SIZE(l2tp_nl_ops),
994 .resv_start_op = L2TP_CMD_SESSION_GET + 1,
995 .mcgrps = l2tp_multicast_group,
996 .n_mcgrps = ARRAY_SIZE(l2tp_multicast_group),
997 };
998
l2tp_nl_register_ops(enum l2tp_pwtype pw_type,const struct l2tp_nl_cmd_ops * ops)999 int l2tp_nl_register_ops(enum l2tp_pwtype pw_type, const struct l2tp_nl_cmd_ops *ops)
1000 {
1001 int ret;
1002
1003 ret = -EINVAL;
1004 if (pw_type >= __L2TP_PWTYPE_MAX)
1005 goto err;
1006
1007 genl_lock();
1008 ret = -EBUSY;
1009 if (l2tp_nl_cmd_ops[pw_type])
1010 goto out;
1011
1012 l2tp_nl_cmd_ops[pw_type] = ops;
1013 ret = 0;
1014
1015 out:
1016 genl_unlock();
1017 err:
1018 return ret;
1019 }
1020 EXPORT_SYMBOL_GPL(l2tp_nl_register_ops);
1021
l2tp_nl_unregister_ops(enum l2tp_pwtype pw_type)1022 void l2tp_nl_unregister_ops(enum l2tp_pwtype pw_type)
1023 {
1024 if (pw_type < __L2TP_PWTYPE_MAX) {
1025 genl_lock();
1026 l2tp_nl_cmd_ops[pw_type] = NULL;
1027 genl_unlock();
1028 }
1029 }
1030 EXPORT_SYMBOL_GPL(l2tp_nl_unregister_ops);
1031
l2tp_nl_init(void)1032 static int __init l2tp_nl_init(void)
1033 {
1034 pr_info("L2TP netlink interface\n");
1035 return genl_register_family(&l2tp_nl_family);
1036 }
1037
l2tp_nl_cleanup(void)1038 static void l2tp_nl_cleanup(void)
1039 {
1040 genl_unregister_family(&l2tp_nl_family);
1041 }
1042
1043 module_init(l2tp_nl_init);
1044 module_exit(l2tp_nl_cleanup);
1045
1046 MODULE_AUTHOR("James Chapman <jchapman@katalix.com>");
1047 MODULE_DESCRIPTION("L2TP netlink");
1048 MODULE_LICENSE("GPL");
1049 MODULE_VERSION("1.0");
1050 MODULE_ALIAS_GENL_FAMILY("l2tp");
1051