xref: /linux/drivers/net/ovpn/netlink.c (revision 6832a9317eee280117cd695fa885b2b7a7a38daf)
1 // SPDX-License-Identifier: GPL-2.0
2 /*  OpenVPN data channel offload
3  *
4  *  Copyright (C) 2020-2025 OpenVPN, Inc.
5  *
6  *  Author:	Antonio Quartulli <antonio@openvpn.net>
7  */
8 
9 #include <linux/netdevice.h>
10 #include <linux/types.h>
11 #include <net/genetlink.h>
12 
13 #include <uapi/linux/ovpn.h>
14 
15 #include "ovpnpriv.h"
16 #include "main.h"
17 #include "netlink.h"
18 #include "netlink-gen.h"
19 #include "bind.h"
20 #include "crypto.h"
21 #include "peer.h"
22 #include "socket.h"
23 
24 MODULE_ALIAS_GENL_FAMILY(OVPN_FAMILY_NAME);
25 
26 /**
27  * ovpn_get_dev_from_attrs - retrieve the ovpn private data from the netdevice
28  *			     a netlink message is targeting
29  * @net: network namespace where to look for the interface
30  * @info: generic netlink info from the user request
31  * @tracker: tracker object to be used for the netdev reference acquisition
32  *
33  * Return: the ovpn private data, if found, or an error otherwise
34  */
35 static struct ovpn_priv *
ovpn_get_dev_from_attrs(struct net * net,const struct genl_info * info,netdevice_tracker * tracker)36 ovpn_get_dev_from_attrs(struct net *net, const struct genl_info *info,
37 			netdevice_tracker *tracker)
38 {
39 	struct ovpn_priv *ovpn;
40 	struct net_device *dev;
41 	int ifindex;
42 
43 	if (GENL_REQ_ATTR_CHECK(info, OVPN_A_IFINDEX))
44 		return ERR_PTR(-EINVAL);
45 
46 	ifindex = nla_get_u32(info->attrs[OVPN_A_IFINDEX]);
47 
48 	rcu_read_lock();
49 	dev = dev_get_by_index_rcu(net, ifindex);
50 	if (!dev) {
51 		rcu_read_unlock();
52 		NL_SET_ERR_MSG_MOD(info->extack,
53 				   "ifindex does not match any interface");
54 		return ERR_PTR(-ENODEV);
55 	}
56 
57 	if (!ovpn_dev_is_valid(dev)) {
58 		rcu_read_unlock();
59 		NL_SET_ERR_MSG_MOD(info->extack,
60 				   "specified interface is not ovpn");
61 		NL_SET_BAD_ATTR(info->extack, info->attrs[OVPN_A_IFINDEX]);
62 		return ERR_PTR(-EINVAL);
63 	}
64 
65 	ovpn = netdev_priv(dev);
66 	netdev_hold(dev, tracker, GFP_ATOMIC);
67 	rcu_read_unlock();
68 
69 	return ovpn;
70 }
71 
ovpn_nl_pre_doit(const struct genl_split_ops * ops,struct sk_buff * skb,struct genl_info * info)72 int ovpn_nl_pre_doit(const struct genl_split_ops *ops, struct sk_buff *skb,
73 		     struct genl_info *info)
74 {
75 	netdevice_tracker *tracker = (netdevice_tracker *)&info->user_ptr[1];
76 	struct ovpn_priv *ovpn = ovpn_get_dev_from_attrs(genl_info_net(info),
77 							 info, tracker);
78 
79 	if (IS_ERR(ovpn))
80 		return PTR_ERR(ovpn);
81 
82 	info->user_ptr[0] = ovpn;
83 
84 	return 0;
85 }
86 
ovpn_nl_post_doit(const struct genl_split_ops * ops,struct sk_buff * skb,struct genl_info * info)87 void ovpn_nl_post_doit(const struct genl_split_ops *ops, struct sk_buff *skb,
88 		       struct genl_info *info)
89 {
90 	netdevice_tracker *tracker = (netdevice_tracker *)&info->user_ptr[1];
91 	struct ovpn_priv *ovpn = info->user_ptr[0];
92 
93 	if (ovpn)
94 		netdev_put(ovpn->dev, tracker);
95 }
96 
ovpn_nl_attr_sockaddr_remote(struct nlattr ** attrs,struct sockaddr_storage * ss)97 static bool ovpn_nl_attr_sockaddr_remote(struct nlattr **attrs,
98 					 struct sockaddr_storage *ss)
99 {
100 	struct sockaddr_in6 *sin6;
101 	struct sockaddr_in *sin;
102 	struct in6_addr *in6;
103 	__be16 port = 0;
104 	__be32 *in;
105 
106 	ss->ss_family = AF_UNSPEC;
107 
108 	if (attrs[OVPN_A_PEER_REMOTE_PORT])
109 		port = nla_get_be16(attrs[OVPN_A_PEER_REMOTE_PORT]);
110 
111 	if (attrs[OVPN_A_PEER_REMOTE_IPV4]) {
112 		ss->ss_family = AF_INET;
113 		in = nla_data(attrs[OVPN_A_PEER_REMOTE_IPV4]);
114 	} else if (attrs[OVPN_A_PEER_REMOTE_IPV6]) {
115 		ss->ss_family = AF_INET6;
116 		in6 = nla_data(attrs[OVPN_A_PEER_REMOTE_IPV6]);
117 	} else {
118 		return false;
119 	}
120 
121 	switch (ss->ss_family) {
122 	case AF_INET6:
123 		/* If this is a regular IPv6 just break and move on,
124 		 * otherwise switch to AF_INET and extract the IPv4 accordingly
125 		 */
126 		if (!ipv6_addr_v4mapped(in6)) {
127 			sin6 = (struct sockaddr_in6 *)ss;
128 			sin6->sin6_port = port;
129 			memcpy(&sin6->sin6_addr, in6, sizeof(*in6));
130 			break;
131 		}
132 
133 		/* v4-mapped-v6 address */
134 		ss->ss_family = AF_INET;
135 		in = &in6->s6_addr32[3];
136 		fallthrough;
137 	case AF_INET:
138 		sin = (struct sockaddr_in *)ss;
139 		sin->sin_port = port;
140 		sin->sin_addr.s_addr = *in;
141 		break;
142 	}
143 
144 	return true;
145 }
146 
ovpn_nl_attr_local_ip(struct nlattr ** attrs)147 static u8 *ovpn_nl_attr_local_ip(struct nlattr **attrs)
148 {
149 	u8 *addr6;
150 
151 	if (!attrs[OVPN_A_PEER_LOCAL_IPV4] && !attrs[OVPN_A_PEER_LOCAL_IPV6])
152 		return NULL;
153 
154 	if (attrs[OVPN_A_PEER_LOCAL_IPV4])
155 		return nla_data(attrs[OVPN_A_PEER_LOCAL_IPV4]);
156 
157 	addr6 = nla_data(attrs[OVPN_A_PEER_LOCAL_IPV6]);
158 	/* this is an IPv4-mapped IPv6 address, therefore extract the actual
159 	 * v4 address from the last 4 bytes
160 	 */
161 	if (ipv6_addr_v4mapped((struct in6_addr *)addr6))
162 		return addr6 + 12;
163 
164 	return addr6;
165 }
166 
ovpn_nl_family_get(struct nlattr * addr4,struct nlattr * addr6)167 static sa_family_t ovpn_nl_family_get(struct nlattr *addr4,
168 				      struct nlattr *addr6)
169 {
170 	if (addr4)
171 		return AF_INET;
172 
173 	if (addr6) {
174 		if (ipv6_addr_v4mapped((struct in6_addr *)nla_data(addr6)))
175 			return AF_INET;
176 		return AF_INET6;
177 	}
178 
179 	return AF_UNSPEC;
180 }
181 
ovpn_nl_peer_precheck(struct ovpn_priv * ovpn,struct genl_info * info,struct nlattr ** attrs)182 static int ovpn_nl_peer_precheck(struct ovpn_priv *ovpn,
183 				 struct genl_info *info,
184 				 struct nlattr **attrs)
185 {
186 	sa_family_t local_fam, remote_fam;
187 
188 	if (NL_REQ_ATTR_CHECK(info->extack, info->attrs[OVPN_A_PEER], attrs,
189 			      OVPN_A_PEER_ID))
190 		return -EINVAL;
191 
192 	if (attrs[OVPN_A_PEER_REMOTE_IPV4] && attrs[OVPN_A_PEER_REMOTE_IPV6]) {
193 		NL_SET_ERR_MSG_MOD(info->extack,
194 				   "cannot specify both remote IPv4 or IPv6 address");
195 		return -EINVAL;
196 	}
197 
198 	if (!attrs[OVPN_A_PEER_REMOTE_IPV4] &&
199 	    !attrs[OVPN_A_PEER_REMOTE_IPV6] && attrs[OVPN_A_PEER_REMOTE_PORT]) {
200 		NL_SET_ERR_MSG_MOD(info->extack,
201 				   "cannot specify remote port without IP address");
202 		return -EINVAL;
203 	}
204 
205 	if ((attrs[OVPN_A_PEER_REMOTE_IPV4] ||
206 	     attrs[OVPN_A_PEER_REMOTE_IPV6]) &&
207 	    !attrs[OVPN_A_PEER_REMOTE_PORT]) {
208 		NL_SET_ERR_MSG_MOD(info->extack,
209 				   "cannot specify remote IP address without port");
210 		return -EINVAL;
211 	}
212 
213 	if (!attrs[OVPN_A_PEER_REMOTE_IPV4] &&
214 	    attrs[OVPN_A_PEER_LOCAL_IPV4]) {
215 		NL_SET_ERR_MSG_MOD(info->extack,
216 				   "cannot specify local IPv4 address without remote");
217 		return -EINVAL;
218 	}
219 
220 	if (!attrs[OVPN_A_PEER_REMOTE_IPV6] &&
221 	    attrs[OVPN_A_PEER_LOCAL_IPV6]) {
222 		NL_SET_ERR_MSG_MOD(info->extack,
223 				   "cannot specify local IPV6 address without remote");
224 		return -EINVAL;
225 	}
226 
227 	/* check that local and remote address families are the same even
228 	 * after parsing v4mapped IPv6 addresses.
229 	 * (if addresses are not provided, family will be AF_UNSPEC and
230 	 * the check is skipped)
231 	 */
232 	local_fam = ovpn_nl_family_get(attrs[OVPN_A_PEER_LOCAL_IPV4],
233 				       attrs[OVPN_A_PEER_LOCAL_IPV6]);
234 	remote_fam = ovpn_nl_family_get(attrs[OVPN_A_PEER_REMOTE_IPV4],
235 					attrs[OVPN_A_PEER_REMOTE_IPV6]);
236 	if (local_fam != AF_UNSPEC && remote_fam != AF_UNSPEC &&
237 	    local_fam != remote_fam) {
238 		NL_SET_ERR_MSG_MOD(info->extack,
239 				   "mismatching local and remote address families");
240 		return -EINVAL;
241 	}
242 
243 	if (remote_fam != AF_INET6 && attrs[OVPN_A_PEER_REMOTE_IPV6_SCOPE_ID]) {
244 		NL_SET_ERR_MSG_MOD(info->extack,
245 				   "cannot specify scope id without remote IPv6 address");
246 		return -EINVAL;
247 	}
248 
249 	/* VPN IPs are needed only in MP mode for selecting the right peer */
250 	if (ovpn->mode == OVPN_MODE_P2P && (attrs[OVPN_A_PEER_VPN_IPV4] ||
251 					    attrs[OVPN_A_PEER_VPN_IPV6])) {
252 		NL_SET_ERR_MSG_FMT_MOD(info->extack,
253 				       "unexpected VPN IP in P2P mode");
254 		return -EINVAL;
255 	}
256 
257 	if ((attrs[OVPN_A_PEER_KEEPALIVE_INTERVAL] &&
258 	     !attrs[OVPN_A_PEER_KEEPALIVE_TIMEOUT]) ||
259 	    (!attrs[OVPN_A_PEER_KEEPALIVE_INTERVAL] &&
260 	     attrs[OVPN_A_PEER_KEEPALIVE_TIMEOUT])) {
261 		NL_SET_ERR_MSG_FMT_MOD(info->extack,
262 				       "keepalive interval and timeout are required together");
263 		return -EINVAL;
264 	}
265 
266 	return 0;
267 }
268 
269 /**
270  * ovpn_nl_peer_modify - modify the peer attributes according to the incoming msg
271  * @peer: the peer to modify
272  * @info: generic netlink info from the user request
273  * @attrs: the attributes from the user request
274  *
275  * Return: a negative error code in case of failure, 0 on success or 1 on
276  *	   success and the VPN IPs have been modified (requires rehashing in MP
277  *	   mode)
278  */
ovpn_nl_peer_modify(struct ovpn_peer * peer,struct genl_info * info,struct nlattr ** attrs)279 static int ovpn_nl_peer_modify(struct ovpn_peer *peer, struct genl_info *info,
280 			       struct nlattr **attrs)
281 {
282 	struct sockaddr_storage ss = {};
283 	void *local_ip = NULL;
284 	u32 interv, timeout;
285 	bool rehash = false;
286 	int ret;
287 
288 	spin_lock_bh(&peer->lock);
289 
290 	if (ovpn_nl_attr_sockaddr_remote(attrs, &ss)) {
291 		/* we carry the local IP in a generic container.
292 		 * ovpn_peer_reset_sockaddr() will properly interpret it
293 		 * based on ss.ss_family
294 		 */
295 		local_ip = ovpn_nl_attr_local_ip(attrs);
296 
297 		/* set peer sockaddr */
298 		ret = ovpn_peer_reset_sockaddr(peer, &ss, local_ip);
299 		if (ret < 0) {
300 			NL_SET_ERR_MSG_FMT_MOD(info->extack,
301 					       "cannot set peer sockaddr: %d",
302 					       ret);
303 			goto err_unlock;
304 		}
305 		dst_cache_reset(&peer->dst_cache);
306 	}
307 
308 	if (attrs[OVPN_A_PEER_VPN_IPV4]) {
309 		rehash = true;
310 		peer->vpn_addrs.ipv4.s_addr =
311 			nla_get_in_addr(attrs[OVPN_A_PEER_VPN_IPV4]);
312 	}
313 
314 	if (attrs[OVPN_A_PEER_VPN_IPV6]) {
315 		rehash = true;
316 		peer->vpn_addrs.ipv6 =
317 			nla_get_in6_addr(attrs[OVPN_A_PEER_VPN_IPV6]);
318 	}
319 
320 	/* when setting the keepalive, both parameters have to be configured */
321 	if (attrs[OVPN_A_PEER_KEEPALIVE_INTERVAL] &&
322 	    attrs[OVPN_A_PEER_KEEPALIVE_TIMEOUT]) {
323 		interv = nla_get_u32(attrs[OVPN_A_PEER_KEEPALIVE_INTERVAL]);
324 		timeout = nla_get_u32(attrs[OVPN_A_PEER_KEEPALIVE_TIMEOUT]);
325 		ovpn_peer_keepalive_set(peer, interv, timeout);
326 	}
327 
328 	netdev_dbg(peer->ovpn->dev,
329 		   "modify peer id=%u endpoint=%pIScp VPN-IPv4=%pI4 VPN-IPv6=%pI6c\n",
330 		   peer->id, &ss,
331 		   &peer->vpn_addrs.ipv4.s_addr, &peer->vpn_addrs.ipv6);
332 
333 	spin_unlock_bh(&peer->lock);
334 
335 	return rehash ? 1 : 0;
336 err_unlock:
337 	spin_unlock_bh(&peer->lock);
338 	return ret;
339 }
340 
ovpn_nl_peer_new_doit(struct sk_buff * skb,struct genl_info * info)341 int ovpn_nl_peer_new_doit(struct sk_buff *skb, struct genl_info *info)
342 {
343 	struct nlattr *attrs[OVPN_A_PEER_MAX + 1];
344 	struct ovpn_priv *ovpn = info->user_ptr[0];
345 	struct ovpn_socket *ovpn_sock;
346 	struct socket *sock = NULL;
347 	struct ovpn_peer *peer;
348 	u32 sockfd, peer_id;
349 	int ret;
350 
351 	if (GENL_REQ_ATTR_CHECK(info, OVPN_A_PEER))
352 		return -EINVAL;
353 
354 	ret = nla_parse_nested(attrs, OVPN_A_PEER_MAX, info->attrs[OVPN_A_PEER],
355 			       ovpn_peer_new_input_nl_policy, info->extack);
356 	if (ret)
357 		return ret;
358 
359 	ret = ovpn_nl_peer_precheck(ovpn, info, attrs);
360 	if (ret < 0)
361 		return ret;
362 
363 	if (NL_REQ_ATTR_CHECK(info->extack, info->attrs[OVPN_A_PEER], attrs,
364 			      OVPN_A_PEER_SOCKET))
365 		return -EINVAL;
366 
367 	/* in MP mode VPN IPs are required for selecting the right peer */
368 	if (ovpn->mode == OVPN_MODE_MP && !attrs[OVPN_A_PEER_VPN_IPV4] &&
369 	    !attrs[OVPN_A_PEER_VPN_IPV6]) {
370 		NL_SET_ERR_MSG_FMT_MOD(info->extack,
371 				       "VPN IP must be provided in MP mode");
372 		return -EINVAL;
373 	}
374 
375 	peer_id = nla_get_u32(attrs[OVPN_A_PEER_ID]);
376 	peer = ovpn_peer_new(ovpn, peer_id);
377 	if (IS_ERR(peer)) {
378 		NL_SET_ERR_MSG_FMT_MOD(info->extack,
379 				       "cannot create new peer object for peer %u: %ld",
380 				       peer_id, PTR_ERR(peer));
381 		return PTR_ERR(peer);
382 	}
383 
384 	/* lookup the fd in the kernel table and extract the socket object */
385 	sockfd = nla_get_u32(attrs[OVPN_A_PEER_SOCKET]);
386 	/* sockfd_lookup() increases sock's refcounter */
387 	sock = sockfd_lookup(sockfd, &ret);
388 	if (!sock) {
389 		NL_SET_ERR_MSG_FMT_MOD(info->extack,
390 				       "cannot lookup peer socket (fd=%u): %d",
391 				       sockfd, ret);
392 		ret = -ENOTSOCK;
393 		goto peer_release;
394 	}
395 
396 	/* Only when using UDP as transport protocol the remote endpoint
397 	 * can be configured so that ovpn knows where to send packets to.
398 	 */
399 	if (sock->sk->sk_protocol == IPPROTO_UDP &&
400 	    !attrs[OVPN_A_PEER_REMOTE_IPV4] &&
401 	    !attrs[OVPN_A_PEER_REMOTE_IPV6]) {
402 		NL_SET_ERR_MSG_FMT_MOD(info->extack,
403 				       "missing remote IP address for UDP socket");
404 		sockfd_put(sock);
405 		ret = -EINVAL;
406 		goto peer_release;
407 	}
408 
409 	/* In case of TCP, the socket is connected to the peer and ovpn
410 	 * will just send bytes over it, without the need to specify a
411 	 * destination.
412 	 */
413 	if (sock->sk->sk_protocol == IPPROTO_TCP &&
414 	    (attrs[OVPN_A_PEER_REMOTE_IPV4] ||
415 	     attrs[OVPN_A_PEER_REMOTE_IPV6])) {
416 		NL_SET_ERR_MSG_FMT_MOD(info->extack,
417 				       "unexpected remote IP address with TCP socket");
418 		sockfd_put(sock);
419 		ret = -EINVAL;
420 		goto peer_release;
421 	}
422 
423 	ovpn_sock = ovpn_socket_new(sock, peer);
424 	/* at this point we unconditionally drop the reference to the socket:
425 	 * - in case of error, the socket has to be dropped
426 	 * - if case of success, the socket is configured and let
427 	 *   userspace own the reference, so that the latter can
428 	 *   trigger the final close()
429 	 */
430 	sockfd_put(sock);
431 	if (IS_ERR(ovpn_sock)) {
432 		NL_SET_ERR_MSG_FMT_MOD(info->extack,
433 				       "cannot encapsulate socket: %ld",
434 				       PTR_ERR(ovpn_sock));
435 		ret = -ENOTSOCK;
436 		goto peer_release;
437 	}
438 
439 	rcu_assign_pointer(peer->sock, ovpn_sock);
440 
441 	ret = ovpn_nl_peer_modify(peer, info, attrs);
442 	if (ret < 0)
443 		goto sock_release;
444 
445 	ret = ovpn_peer_add(ovpn, peer);
446 	if (ret < 0) {
447 		NL_SET_ERR_MSG_FMT_MOD(info->extack,
448 				       "cannot add new peer (id=%u) to hashtable: %d",
449 				       peer->id, ret);
450 		goto sock_release;
451 	}
452 
453 	return 0;
454 
455 sock_release:
456 	ovpn_socket_release(peer);
457 peer_release:
458 	/* release right away because peer was not yet hashed, thus it is not
459 	 * used in any context
460 	 */
461 	ovpn_peer_release(peer);
462 
463 	return ret;
464 }
465 
ovpn_nl_peer_set_doit(struct sk_buff * skb,struct genl_info * info)466 int ovpn_nl_peer_set_doit(struct sk_buff *skb, struct genl_info *info)
467 {
468 	struct nlattr *attrs[OVPN_A_PEER_MAX + 1];
469 	struct ovpn_priv *ovpn = info->user_ptr[0];
470 	struct ovpn_socket *sock;
471 	struct ovpn_peer *peer;
472 	u32 peer_id;
473 	int ret;
474 
475 	if (GENL_REQ_ATTR_CHECK(info, OVPN_A_PEER))
476 		return -EINVAL;
477 
478 	ret = nla_parse_nested(attrs, OVPN_A_PEER_MAX, info->attrs[OVPN_A_PEER],
479 			       ovpn_peer_set_input_nl_policy, info->extack);
480 	if (ret)
481 		return ret;
482 
483 	ret = ovpn_nl_peer_precheck(ovpn, info, attrs);
484 	if (ret < 0)
485 		return ret;
486 
487 	if (attrs[OVPN_A_PEER_SOCKET]) {
488 		NL_SET_ERR_MSG_FMT_MOD(info->extack,
489 				       "socket cannot be modified");
490 		return -EINVAL;
491 	}
492 
493 	peer_id = nla_get_u32(attrs[OVPN_A_PEER_ID]);
494 	peer = ovpn_peer_get_by_id(ovpn, peer_id);
495 	if (!peer) {
496 		NL_SET_ERR_MSG_FMT_MOD(info->extack,
497 				       "cannot find peer with id %u", peer_id);
498 		return -ENOENT;
499 	}
500 
501 	/* when using a TCP socket the remote IP is not expected */
502 	rcu_read_lock();
503 	sock = rcu_dereference(peer->sock);
504 	if (sock && sock->sk->sk_protocol == IPPROTO_TCP &&
505 	    (attrs[OVPN_A_PEER_REMOTE_IPV4] ||
506 	     attrs[OVPN_A_PEER_REMOTE_IPV6])) {
507 		rcu_read_unlock();
508 		NL_SET_ERR_MSG_FMT_MOD(info->extack,
509 				       "unexpected remote IP address with TCP socket");
510 		ovpn_peer_put(peer);
511 		return -EINVAL;
512 	}
513 	rcu_read_unlock();
514 
515 	spin_lock_bh(&ovpn->lock);
516 	ret = ovpn_nl_peer_modify(peer, info, attrs);
517 	if (ret < 0) {
518 		spin_unlock_bh(&ovpn->lock);
519 		ovpn_peer_put(peer);
520 		return ret;
521 	}
522 
523 	/* ret == 1 means that VPN IPv4/6 has been modified and rehashing
524 	 * is required
525 	 */
526 	if (ret > 0)
527 		ovpn_peer_hash_vpn_ip(peer);
528 	spin_unlock_bh(&ovpn->lock);
529 	ovpn_peer_put(peer);
530 
531 	return 0;
532 }
533 
ovpn_nl_send_peer(struct sk_buff * skb,const struct genl_info * info,const struct ovpn_peer * peer,u32 portid,u32 seq,int flags)534 static int ovpn_nl_send_peer(struct sk_buff *skb, const struct genl_info *info,
535 			     const struct ovpn_peer *peer, u32 portid, u32 seq,
536 			     int flags)
537 {
538 	const struct ovpn_bind *bind;
539 	struct ovpn_socket *sock;
540 	int ret = -EMSGSIZE;
541 	struct nlattr *attr;
542 	__be16 local_port;
543 	void *hdr;
544 	int id;
545 
546 	hdr = genlmsg_put(skb, portid, seq, &ovpn_nl_family, flags,
547 			  OVPN_CMD_PEER_GET);
548 	if (!hdr)
549 		return -ENOBUFS;
550 
551 	attr = nla_nest_start(skb, OVPN_A_PEER);
552 	if (!attr)
553 		goto err;
554 
555 	rcu_read_lock();
556 	sock = rcu_dereference(peer->sock);
557 	if (!sock) {
558 		ret = -EINVAL;
559 		goto err_unlock;
560 	}
561 
562 	if (!net_eq(genl_info_net(info), sock_net(sock->sk))) {
563 		id = peernet2id_alloc(genl_info_net(info),
564 				      sock_net(sock->sk),
565 				      GFP_ATOMIC);
566 		if (nla_put_s32(skb, OVPN_A_PEER_SOCKET_NETNSID, id))
567 			goto err_unlock;
568 	}
569 	local_port = inet_sk(sock->sk)->inet_sport;
570 	rcu_read_unlock();
571 
572 	if (nla_put_u32(skb, OVPN_A_PEER_ID, peer->id))
573 		goto err;
574 
575 	if (peer->vpn_addrs.ipv4.s_addr != htonl(INADDR_ANY))
576 		if (nla_put_in_addr(skb, OVPN_A_PEER_VPN_IPV4,
577 				    peer->vpn_addrs.ipv4.s_addr))
578 			goto err;
579 
580 	if (!ipv6_addr_equal(&peer->vpn_addrs.ipv6, &in6addr_any))
581 		if (nla_put_in6_addr(skb, OVPN_A_PEER_VPN_IPV6,
582 				     &peer->vpn_addrs.ipv6))
583 			goto err;
584 
585 	if (nla_put_u32(skb, OVPN_A_PEER_KEEPALIVE_INTERVAL,
586 			peer->keepalive_interval) ||
587 	    nla_put_u32(skb, OVPN_A_PEER_KEEPALIVE_TIMEOUT,
588 			peer->keepalive_timeout))
589 		goto err;
590 
591 	rcu_read_lock();
592 	bind = rcu_dereference(peer->bind);
593 	if (bind) {
594 		if (bind->remote.in4.sin_family == AF_INET) {
595 			if (nla_put_in_addr(skb, OVPN_A_PEER_REMOTE_IPV4,
596 					    bind->remote.in4.sin_addr.s_addr) ||
597 			    nla_put_net16(skb, OVPN_A_PEER_REMOTE_PORT,
598 					  bind->remote.in4.sin_port) ||
599 			    nla_put_in_addr(skb, OVPN_A_PEER_LOCAL_IPV4,
600 					    bind->local.ipv4.s_addr))
601 				goto err_unlock;
602 		} else if (bind->remote.in4.sin_family == AF_INET6) {
603 			if (nla_put_in6_addr(skb, OVPN_A_PEER_REMOTE_IPV6,
604 					     &bind->remote.in6.sin6_addr) ||
605 			    nla_put_u32(skb, OVPN_A_PEER_REMOTE_IPV6_SCOPE_ID,
606 					bind->remote.in6.sin6_scope_id) ||
607 			    nla_put_net16(skb, OVPN_A_PEER_REMOTE_PORT,
608 					  bind->remote.in6.sin6_port) ||
609 			    nla_put_in6_addr(skb, OVPN_A_PEER_LOCAL_IPV6,
610 					     &bind->local.ipv6))
611 				goto err_unlock;
612 		}
613 	}
614 	rcu_read_unlock();
615 
616 	if (nla_put_net16(skb, OVPN_A_PEER_LOCAL_PORT, local_port) ||
617 	    /* VPN RX stats */
618 	    nla_put_uint(skb, OVPN_A_PEER_VPN_RX_BYTES,
619 			 atomic64_read(&peer->vpn_stats.rx.bytes)) ||
620 	    nla_put_uint(skb, OVPN_A_PEER_VPN_RX_PACKETS,
621 			 atomic64_read(&peer->vpn_stats.rx.packets)) ||
622 	    /* VPN TX stats */
623 	    nla_put_uint(skb, OVPN_A_PEER_VPN_TX_BYTES,
624 			 atomic64_read(&peer->vpn_stats.tx.bytes)) ||
625 	    nla_put_uint(skb, OVPN_A_PEER_VPN_TX_PACKETS,
626 			 atomic64_read(&peer->vpn_stats.tx.packets)) ||
627 	    /* link RX stats */
628 	    nla_put_uint(skb, OVPN_A_PEER_LINK_RX_BYTES,
629 			 atomic64_read(&peer->link_stats.rx.bytes)) ||
630 	    nla_put_uint(skb, OVPN_A_PEER_LINK_RX_PACKETS,
631 			 atomic64_read(&peer->link_stats.rx.packets)) ||
632 	    /* link TX stats */
633 	    nla_put_uint(skb, OVPN_A_PEER_LINK_TX_BYTES,
634 			 atomic64_read(&peer->link_stats.tx.bytes)) ||
635 	    nla_put_uint(skb, OVPN_A_PEER_LINK_TX_PACKETS,
636 			 atomic64_read(&peer->link_stats.tx.packets)))
637 		goto err;
638 
639 	nla_nest_end(skb, attr);
640 	genlmsg_end(skb, hdr);
641 
642 	return 0;
643 err_unlock:
644 	rcu_read_unlock();
645 err:
646 	genlmsg_cancel(skb, hdr);
647 	return ret;
648 }
649 
ovpn_nl_peer_get_doit(struct sk_buff * skb,struct genl_info * info)650 int ovpn_nl_peer_get_doit(struct sk_buff *skb, struct genl_info *info)
651 {
652 	struct nlattr *attrs[OVPN_A_PEER_MAX + 1];
653 	struct ovpn_priv *ovpn = info->user_ptr[0];
654 	struct ovpn_peer *peer;
655 	struct sk_buff *msg;
656 	u32 peer_id;
657 	int ret, i;
658 
659 	if (GENL_REQ_ATTR_CHECK(info, OVPN_A_PEER))
660 		return -EINVAL;
661 
662 	ret = nla_parse_nested(attrs, OVPN_A_PEER_MAX, info->attrs[OVPN_A_PEER],
663 			       ovpn_peer_nl_policy, info->extack);
664 	if (ret)
665 		return ret;
666 
667 	if (NL_REQ_ATTR_CHECK(info->extack, info->attrs[OVPN_A_PEER], attrs,
668 			      OVPN_A_PEER_ID))
669 		return -EINVAL;
670 
671 	/* OVPN_CMD_PEER_GET expects only the PEER_ID, therefore
672 	 * ensure that the user hasn't specified any other attribute.
673 	 *
674 	 * Unfortunately this check cannot be performed via netlink
675 	 * spec/policy and must be open-coded.
676 	 */
677 	for (i = 0; i < OVPN_A_PEER_MAX + 1; i++) {
678 		if (i == OVPN_A_PEER_ID)
679 			continue;
680 
681 		if (attrs[i]) {
682 			NL_SET_ERR_MSG_FMT_MOD(info->extack,
683 					       "unexpected attribute %u", i);
684 			return -EINVAL;
685 		}
686 	}
687 
688 	peer_id = nla_get_u32(attrs[OVPN_A_PEER_ID]);
689 	peer = ovpn_peer_get_by_id(ovpn, peer_id);
690 	if (!peer) {
691 		NL_SET_ERR_MSG_FMT_MOD(info->extack,
692 				       "cannot find peer with id %u", peer_id);
693 		return -ENOENT;
694 	}
695 
696 	msg = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);
697 	if (!msg) {
698 		ret = -ENOMEM;
699 		goto err;
700 	}
701 
702 	ret = ovpn_nl_send_peer(msg, info, peer, info->snd_portid,
703 				info->snd_seq, 0);
704 	if (ret < 0) {
705 		nlmsg_free(msg);
706 		goto err;
707 	}
708 
709 	ret = genlmsg_reply(msg, info);
710 err:
711 	ovpn_peer_put(peer);
712 	return ret;
713 }
714 
ovpn_nl_peer_get_dumpit(struct sk_buff * skb,struct netlink_callback * cb)715 int ovpn_nl_peer_get_dumpit(struct sk_buff *skb, struct netlink_callback *cb)
716 {
717 	const struct genl_info *info = genl_info_dump(cb);
718 	int bkt, last_idx = cb->args[1], dumped = 0;
719 	netdevice_tracker tracker;
720 	struct ovpn_priv *ovpn;
721 	struct ovpn_peer *peer;
722 
723 	ovpn = ovpn_get_dev_from_attrs(sock_net(cb->skb->sk), info, &tracker);
724 	if (IS_ERR(ovpn))
725 		return PTR_ERR(ovpn);
726 
727 	if (ovpn->mode == OVPN_MODE_P2P) {
728 		/* if we already dumped a peer it means we are done */
729 		if (last_idx)
730 			goto out;
731 
732 		rcu_read_lock();
733 		peer = rcu_dereference(ovpn->peer);
734 		if (peer) {
735 			if (ovpn_nl_send_peer(skb, info, peer,
736 					      NETLINK_CB(cb->skb).portid,
737 					      cb->nlh->nlmsg_seq,
738 					      NLM_F_MULTI) == 0)
739 				dumped++;
740 		}
741 		rcu_read_unlock();
742 	} else {
743 		rcu_read_lock();
744 		hash_for_each_rcu(ovpn->peers->by_id, bkt, peer,
745 				  hash_entry_id) {
746 			/* skip already dumped peers that were dumped by
747 			 * previous invocations
748 			 */
749 			if (last_idx > 0) {
750 				last_idx--;
751 				continue;
752 			}
753 
754 			if (ovpn_nl_send_peer(skb, info, peer,
755 					      NETLINK_CB(cb->skb).portid,
756 					      cb->nlh->nlmsg_seq,
757 					      NLM_F_MULTI) < 0)
758 				break;
759 
760 			/* count peers being dumped during this invocation */
761 			dumped++;
762 		}
763 		rcu_read_unlock();
764 	}
765 
766 out:
767 	netdev_put(ovpn->dev, &tracker);
768 
769 	/* sum up peers dumped in this message, so that at the next invocation
770 	 * we can continue from where we left
771 	 */
772 	cb->args[1] += dumped;
773 	return skb->len;
774 }
775 
ovpn_nl_peer_del_doit(struct sk_buff * skb,struct genl_info * info)776 int ovpn_nl_peer_del_doit(struct sk_buff *skb, struct genl_info *info)
777 {
778 	struct nlattr *attrs[OVPN_A_PEER_MAX + 1];
779 	struct ovpn_priv *ovpn = info->user_ptr[0];
780 	struct ovpn_peer *peer;
781 	u32 peer_id;
782 	int ret;
783 
784 	if (GENL_REQ_ATTR_CHECK(info, OVPN_A_PEER))
785 		return -EINVAL;
786 
787 	ret = nla_parse_nested(attrs, OVPN_A_PEER_MAX, info->attrs[OVPN_A_PEER],
788 			       ovpn_peer_del_input_nl_policy, info->extack);
789 	if (ret)
790 		return ret;
791 
792 	if (NL_REQ_ATTR_CHECK(info->extack, info->attrs[OVPN_A_PEER], attrs,
793 			      OVPN_A_PEER_ID))
794 		return -EINVAL;
795 
796 	peer_id = nla_get_u32(attrs[OVPN_A_PEER_ID]);
797 	peer = ovpn_peer_get_by_id(ovpn, peer_id);
798 	if (!peer) {
799 		NL_SET_ERR_MSG_FMT_MOD(info->extack,
800 				       "cannot find peer with id %u", peer_id);
801 		return -ENOENT;
802 	}
803 
804 	netdev_dbg(ovpn->dev, "del peer %u\n", peer->id);
805 	ret = ovpn_peer_del(peer, OVPN_DEL_PEER_REASON_USERSPACE);
806 	ovpn_peer_put(peer);
807 
808 	return ret;
809 }
810 
ovpn_nl_get_key_dir(struct genl_info * info,struct nlattr * key,enum ovpn_cipher_alg cipher,struct ovpn_key_direction * dir)811 static int ovpn_nl_get_key_dir(struct genl_info *info, struct nlattr *key,
812 			       enum ovpn_cipher_alg cipher,
813 			       struct ovpn_key_direction *dir)
814 {
815 	struct nlattr *attrs[OVPN_A_KEYDIR_MAX + 1];
816 	int ret;
817 
818 	ret = nla_parse_nested(attrs, OVPN_A_KEYDIR_MAX, key,
819 			       ovpn_keydir_nl_policy, info->extack);
820 	if (ret)
821 		return ret;
822 
823 	switch (cipher) {
824 	case OVPN_CIPHER_ALG_AES_GCM:
825 	case OVPN_CIPHER_ALG_CHACHA20_POLY1305:
826 		if (NL_REQ_ATTR_CHECK(info->extack, key, attrs,
827 				      OVPN_A_KEYDIR_CIPHER_KEY) ||
828 		    NL_REQ_ATTR_CHECK(info->extack, key, attrs,
829 				      OVPN_A_KEYDIR_NONCE_TAIL))
830 			return -EINVAL;
831 
832 		dir->cipher_key = nla_data(attrs[OVPN_A_KEYDIR_CIPHER_KEY]);
833 		dir->cipher_key_size = nla_len(attrs[OVPN_A_KEYDIR_CIPHER_KEY]);
834 
835 		/* These algorithms require a 96bit nonce,
836 		 * Construct it by combining 4-bytes packet id and
837 		 * 8-bytes nonce-tail from userspace
838 		 */
839 		dir->nonce_tail = nla_data(attrs[OVPN_A_KEYDIR_NONCE_TAIL]);
840 		dir->nonce_tail_size = nla_len(attrs[OVPN_A_KEYDIR_NONCE_TAIL]);
841 		break;
842 	default:
843 		NL_SET_ERR_MSG_MOD(info->extack, "unsupported cipher");
844 		return -EINVAL;
845 	}
846 
847 	return 0;
848 }
849 
850 /**
851  * ovpn_nl_key_new_doit - configure a new key for the specified peer
852  * @skb: incoming netlink message
853  * @info: genetlink metadata
854  *
855  * This function allows the user to install a new key in the peer crypto
856  * state.
857  * Each peer has two 'slots', namely 'primary' and 'secondary', where
858  * keys can be installed. The key in the 'primary' slot is used for
859  * encryption, while both keys can be used for decryption by matching the
860  * key ID carried in the incoming packet.
861  *
862  * The user is responsible for rotating keys when necessary. The user
863  * may fetch peer traffic statistics via netlink in order to better
864  * identify the right time to rotate keys.
865  * The renegotiation follows these steps:
866  * 1. a new key is computed by the user and is installed in the 'secondary'
867  *    slot
868  * 2. at user discretion (usually after a predetermined time) 'primary' and
869  *    'secondary' contents are swapped and the new key starts being used for
870  *    encryption, while the old key is kept around for decryption of late
871  *    packets.
872  *
873  * Return: 0 on success or a negative error code otherwise.
874  */
ovpn_nl_key_new_doit(struct sk_buff * skb,struct genl_info * info)875 int ovpn_nl_key_new_doit(struct sk_buff *skb, struct genl_info *info)
876 {
877 	struct nlattr *attrs[OVPN_A_KEYCONF_MAX + 1];
878 	struct ovpn_priv *ovpn = info->user_ptr[0];
879 	struct ovpn_peer_key_reset pkr;
880 	struct ovpn_peer *peer;
881 	u32 peer_id;
882 	int ret;
883 
884 	if (GENL_REQ_ATTR_CHECK(info, OVPN_A_KEYCONF))
885 		return -EINVAL;
886 
887 	ret = nla_parse_nested(attrs, OVPN_A_KEYCONF_MAX,
888 			       info->attrs[OVPN_A_KEYCONF],
889 			       ovpn_keyconf_nl_policy, info->extack);
890 	if (ret)
891 		return ret;
892 
893 	if (NL_REQ_ATTR_CHECK(info->extack, info->attrs[OVPN_A_KEYCONF], attrs,
894 			      OVPN_A_KEYCONF_PEER_ID))
895 		return -EINVAL;
896 
897 	if (NL_REQ_ATTR_CHECK(info->extack, info->attrs[OVPN_A_KEYCONF], attrs,
898 			      OVPN_A_KEYCONF_SLOT) ||
899 	    NL_REQ_ATTR_CHECK(info->extack, info->attrs[OVPN_A_KEYCONF], attrs,
900 			      OVPN_A_KEYCONF_KEY_ID) ||
901 	    NL_REQ_ATTR_CHECK(info->extack, info->attrs[OVPN_A_KEYCONF], attrs,
902 			      OVPN_A_KEYCONF_CIPHER_ALG) ||
903 	    NL_REQ_ATTR_CHECK(info->extack, info->attrs[OVPN_A_KEYCONF], attrs,
904 			      OVPN_A_KEYCONF_ENCRYPT_DIR) ||
905 	    NL_REQ_ATTR_CHECK(info->extack, info->attrs[OVPN_A_KEYCONF], attrs,
906 			      OVPN_A_KEYCONF_DECRYPT_DIR))
907 		return -EINVAL;
908 
909 	pkr.slot = nla_get_u32(attrs[OVPN_A_KEYCONF_SLOT]);
910 	pkr.key.key_id = nla_get_u32(attrs[OVPN_A_KEYCONF_KEY_ID]);
911 	pkr.key.cipher_alg = nla_get_u32(attrs[OVPN_A_KEYCONF_CIPHER_ALG]);
912 
913 	ret = ovpn_nl_get_key_dir(info, attrs[OVPN_A_KEYCONF_ENCRYPT_DIR],
914 				  pkr.key.cipher_alg, &pkr.key.encrypt);
915 	if (ret < 0)
916 		return ret;
917 
918 	ret = ovpn_nl_get_key_dir(info, attrs[OVPN_A_KEYCONF_DECRYPT_DIR],
919 				  pkr.key.cipher_alg, &pkr.key.decrypt);
920 	if (ret < 0)
921 		return ret;
922 
923 	peer_id = nla_get_u32(attrs[OVPN_A_KEYCONF_PEER_ID]);
924 	peer = ovpn_peer_get_by_id(ovpn, peer_id);
925 	if (!peer) {
926 		NL_SET_ERR_MSG_FMT_MOD(info->extack,
927 				       "no peer with id %u to set key for",
928 				       peer_id);
929 		return -ENOENT;
930 	}
931 
932 	ret = ovpn_crypto_state_reset(&peer->crypto, &pkr);
933 	if (ret < 0) {
934 		NL_SET_ERR_MSG_FMT_MOD(info->extack,
935 				       "cannot install new key for peer %u",
936 				       peer_id);
937 		goto out;
938 	}
939 
940 	netdev_dbg(ovpn->dev, "new key installed (id=%u) for peer %u\n",
941 		   pkr.key.key_id, peer_id);
942 out:
943 	ovpn_peer_put(peer);
944 	return ret;
945 }
946 
ovpn_nl_send_key(struct sk_buff * skb,const struct genl_info * info,u32 peer_id,enum ovpn_key_slot slot,const struct ovpn_key_config * keyconf)947 static int ovpn_nl_send_key(struct sk_buff *skb, const struct genl_info *info,
948 			    u32 peer_id, enum ovpn_key_slot slot,
949 			    const struct ovpn_key_config *keyconf)
950 {
951 	struct nlattr *attr;
952 	void *hdr;
953 
954 	hdr = genlmsg_put(skb, info->snd_portid, info->snd_seq, &ovpn_nl_family,
955 			  0, OVPN_CMD_KEY_GET);
956 	if (!hdr)
957 		return -ENOBUFS;
958 
959 	attr = nla_nest_start(skb, OVPN_A_KEYCONF);
960 	if (!attr)
961 		goto err;
962 
963 	if (nla_put_u32(skb, OVPN_A_KEYCONF_PEER_ID, peer_id))
964 		goto err;
965 
966 	if (nla_put_u32(skb, OVPN_A_KEYCONF_SLOT, slot) ||
967 	    nla_put_u32(skb, OVPN_A_KEYCONF_KEY_ID, keyconf->key_id) ||
968 	    nla_put_u32(skb, OVPN_A_KEYCONF_CIPHER_ALG, keyconf->cipher_alg))
969 		goto err;
970 
971 	nla_nest_end(skb, attr);
972 	genlmsg_end(skb, hdr);
973 
974 	return 0;
975 err:
976 	genlmsg_cancel(skb, hdr);
977 	return -EMSGSIZE;
978 }
979 
ovpn_nl_key_get_doit(struct sk_buff * skb,struct genl_info * info)980 int ovpn_nl_key_get_doit(struct sk_buff *skb, struct genl_info *info)
981 {
982 	struct nlattr *attrs[OVPN_A_KEYCONF_MAX + 1];
983 	struct ovpn_priv *ovpn = info->user_ptr[0];
984 	struct ovpn_key_config keyconf = { 0 };
985 	enum ovpn_key_slot slot;
986 	struct ovpn_peer *peer;
987 	struct sk_buff *msg;
988 	u32 peer_id;
989 	int ret, i;
990 
991 	if (GENL_REQ_ATTR_CHECK(info, OVPN_A_KEYCONF))
992 		return -EINVAL;
993 
994 	ret = nla_parse_nested(attrs, OVPN_A_KEYCONF_MAX,
995 			       info->attrs[OVPN_A_KEYCONF],
996 			       ovpn_keyconf_get_nl_policy, info->extack);
997 	if (ret)
998 		return ret;
999 
1000 	if (NL_REQ_ATTR_CHECK(info->extack, info->attrs[OVPN_A_KEYCONF], attrs,
1001 			      OVPN_A_KEYCONF_PEER_ID))
1002 		return -EINVAL;
1003 
1004 	if (NL_REQ_ATTR_CHECK(info->extack, info->attrs[OVPN_A_KEYCONF], attrs,
1005 			      OVPN_A_KEYCONF_SLOT))
1006 		return -EINVAL;
1007 
1008 	/* OVPN_CMD_KEY_GET expects only the PEER_ID and the SLOT, therefore
1009 	 * ensure that the user hasn't specified any other attribute.
1010 	 *
1011 	 * Unfortunately this check cannot be performed via netlink
1012 	 * spec/policy and must be open-coded.
1013 	 */
1014 	for (i = 0; i < OVPN_A_KEYCONF_MAX + 1; i++) {
1015 		if (i == OVPN_A_KEYCONF_PEER_ID ||
1016 		    i == OVPN_A_KEYCONF_SLOT)
1017 			continue;
1018 
1019 		if (attrs[i]) {
1020 			NL_SET_ERR_MSG_FMT_MOD(info->extack,
1021 					       "unexpected attribute %u", i);
1022 			return -EINVAL;
1023 		}
1024 	}
1025 
1026 	peer_id = nla_get_u32(attrs[OVPN_A_KEYCONF_PEER_ID]);
1027 	peer = ovpn_peer_get_by_id(ovpn, peer_id);
1028 	if (!peer) {
1029 		NL_SET_ERR_MSG_FMT_MOD(info->extack,
1030 				       "cannot find peer with id %u", peer_id);
1031 		return -ENOENT;
1032 	}
1033 
1034 	slot = nla_get_u32(attrs[OVPN_A_KEYCONF_SLOT]);
1035 
1036 	ret = ovpn_crypto_config_get(&peer->crypto, slot, &keyconf);
1037 	if (ret < 0) {
1038 		NL_SET_ERR_MSG_FMT_MOD(info->extack,
1039 				       "cannot extract key from slot %u for peer %u",
1040 				       slot, peer_id);
1041 		goto err;
1042 	}
1043 
1044 	msg = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);
1045 	if (!msg) {
1046 		ret = -ENOMEM;
1047 		goto err;
1048 	}
1049 
1050 	ret = ovpn_nl_send_key(msg, info, peer->id, slot, &keyconf);
1051 	if (ret < 0) {
1052 		nlmsg_free(msg);
1053 		goto err;
1054 	}
1055 
1056 	ret = genlmsg_reply(msg, info);
1057 err:
1058 	ovpn_peer_put(peer);
1059 	return ret;
1060 }
1061 
ovpn_nl_key_swap_doit(struct sk_buff * skb,struct genl_info * info)1062 int ovpn_nl_key_swap_doit(struct sk_buff *skb, struct genl_info *info)
1063 {
1064 	struct ovpn_priv *ovpn = info->user_ptr[0];
1065 	struct nlattr *attrs[OVPN_A_PEER_MAX + 1];
1066 	struct ovpn_peer *peer;
1067 	u32 peer_id;
1068 	int ret;
1069 
1070 	if (GENL_REQ_ATTR_CHECK(info, OVPN_A_KEYCONF))
1071 		return -EINVAL;
1072 
1073 	ret = nla_parse_nested(attrs, OVPN_A_KEYCONF_MAX,
1074 			       info->attrs[OVPN_A_KEYCONF],
1075 			       ovpn_keyconf_swap_input_nl_policy, info->extack);
1076 	if (ret)
1077 		return ret;
1078 
1079 	if (NL_REQ_ATTR_CHECK(info->extack, info->attrs[OVPN_A_KEYCONF], attrs,
1080 			      OVPN_A_KEYCONF_PEER_ID))
1081 		return -EINVAL;
1082 
1083 	peer_id = nla_get_u32(attrs[OVPN_A_KEYCONF_PEER_ID]);
1084 	peer = ovpn_peer_get_by_id(ovpn, peer_id);
1085 	if (!peer) {
1086 		NL_SET_ERR_MSG_FMT_MOD(info->extack,
1087 				       "no peer with id %u to swap keys for",
1088 				       peer_id);
1089 		return -ENOENT;
1090 	}
1091 
1092 	ovpn_crypto_key_slots_swap(&peer->crypto);
1093 	ovpn_peer_put(peer);
1094 
1095 	return 0;
1096 }
1097 
ovpn_nl_key_del_doit(struct sk_buff * skb,struct genl_info * info)1098 int ovpn_nl_key_del_doit(struct sk_buff *skb, struct genl_info *info)
1099 {
1100 	struct nlattr *attrs[OVPN_A_KEYCONF_MAX + 1];
1101 	struct ovpn_priv *ovpn = info->user_ptr[0];
1102 	enum ovpn_key_slot slot;
1103 	struct ovpn_peer *peer;
1104 	u32 peer_id;
1105 	int ret;
1106 
1107 	if (GENL_REQ_ATTR_CHECK(info, OVPN_A_KEYCONF))
1108 		return -EINVAL;
1109 
1110 	ret = nla_parse_nested(attrs, OVPN_A_KEYCONF_MAX,
1111 			       info->attrs[OVPN_A_KEYCONF],
1112 			       ovpn_keyconf_del_input_nl_policy, info->extack);
1113 	if (ret)
1114 		return ret;
1115 
1116 	if (NL_REQ_ATTR_CHECK(info->extack, info->attrs[OVPN_A_KEYCONF], attrs,
1117 			      OVPN_A_KEYCONF_PEER_ID))
1118 		return -EINVAL;
1119 
1120 	if (NL_REQ_ATTR_CHECK(info->extack, info->attrs[OVPN_A_KEYCONF], attrs,
1121 			      OVPN_A_KEYCONF_SLOT))
1122 		return -EINVAL;
1123 
1124 	peer_id = nla_get_u32(attrs[OVPN_A_KEYCONF_PEER_ID]);
1125 	slot = nla_get_u32(attrs[OVPN_A_KEYCONF_SLOT]);
1126 
1127 	peer = ovpn_peer_get_by_id(ovpn, peer_id);
1128 	if (!peer) {
1129 		NL_SET_ERR_MSG_FMT_MOD(info->extack,
1130 				       "no peer with id %u to delete key for",
1131 				       peer_id);
1132 		return -ENOENT;
1133 	}
1134 
1135 	ovpn_crypto_key_slot_delete(&peer->crypto, slot);
1136 	ovpn_peer_put(peer);
1137 
1138 	return 0;
1139 }
1140 
1141 /**
1142  * ovpn_nl_peer_del_notify - notify userspace about peer being deleted
1143  * @peer: the peer being deleted
1144  *
1145  * Return: 0 on success or a negative error code otherwise
1146  */
ovpn_nl_peer_del_notify(struct ovpn_peer * peer)1147 int ovpn_nl_peer_del_notify(struct ovpn_peer *peer)
1148 {
1149 	struct ovpn_socket *sock;
1150 	struct sk_buff *msg;
1151 	struct nlattr *attr;
1152 	int ret = -EMSGSIZE;
1153 	void *hdr;
1154 
1155 	netdev_info(peer->ovpn->dev, "deleting peer with id %u, reason %d\n",
1156 		    peer->id, peer->delete_reason);
1157 
1158 	msg = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_ATOMIC);
1159 	if (!msg)
1160 		return -ENOMEM;
1161 
1162 	hdr = genlmsg_put(msg, 0, 0, &ovpn_nl_family, 0, OVPN_CMD_PEER_DEL_NTF);
1163 	if (!hdr) {
1164 		ret = -ENOBUFS;
1165 		goto err_free_msg;
1166 	}
1167 
1168 	if (nla_put_u32(msg, OVPN_A_IFINDEX, peer->ovpn->dev->ifindex))
1169 		goto err_cancel_msg;
1170 
1171 	attr = nla_nest_start(msg, OVPN_A_PEER);
1172 	if (!attr)
1173 		goto err_cancel_msg;
1174 
1175 	if (nla_put_u32(msg, OVPN_A_PEER_DEL_REASON, peer->delete_reason))
1176 		goto err_cancel_msg;
1177 
1178 	if (nla_put_u32(msg, OVPN_A_PEER_ID, peer->id))
1179 		goto err_cancel_msg;
1180 
1181 	nla_nest_end(msg, attr);
1182 
1183 	genlmsg_end(msg, hdr);
1184 
1185 	rcu_read_lock();
1186 	sock = rcu_dereference(peer->sock);
1187 	if (!sock) {
1188 		ret = -EINVAL;
1189 		goto err_unlock;
1190 	}
1191 	genlmsg_multicast_netns(&ovpn_nl_family, sock_net(sock->sk), msg, 0,
1192 				OVPN_NLGRP_PEERS, GFP_ATOMIC);
1193 	rcu_read_unlock();
1194 
1195 	return 0;
1196 
1197 err_unlock:
1198 	rcu_read_unlock();
1199 err_cancel_msg:
1200 	genlmsg_cancel(msg, hdr);
1201 err_free_msg:
1202 	nlmsg_free(msg);
1203 	return ret;
1204 }
1205 
1206 /**
1207  * ovpn_nl_key_swap_notify - notify userspace peer's key must be renewed
1208  * @peer: the peer whose key needs to be renewed
1209  * @key_id: the ID of the key that needs to be renewed
1210  *
1211  * Return: 0 on success or a negative error code otherwise
1212  */
ovpn_nl_key_swap_notify(struct ovpn_peer * peer,u8 key_id)1213 int ovpn_nl_key_swap_notify(struct ovpn_peer *peer, u8 key_id)
1214 {
1215 	struct ovpn_socket *sock;
1216 	struct nlattr *k_attr;
1217 	struct sk_buff *msg;
1218 	int ret = -EMSGSIZE;
1219 	void *hdr;
1220 
1221 	netdev_info(peer->ovpn->dev, "peer with id %u must rekey - primary key unusable.\n",
1222 		    peer->id);
1223 
1224 	msg = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_ATOMIC);
1225 	if (!msg)
1226 		return -ENOMEM;
1227 
1228 	hdr = genlmsg_put(msg, 0, 0, &ovpn_nl_family, 0, OVPN_CMD_KEY_SWAP_NTF);
1229 	if (!hdr) {
1230 		ret = -ENOBUFS;
1231 		goto err_free_msg;
1232 	}
1233 
1234 	if (nla_put_u32(msg, OVPN_A_IFINDEX, peer->ovpn->dev->ifindex))
1235 		goto err_cancel_msg;
1236 
1237 	k_attr = nla_nest_start(msg, OVPN_A_KEYCONF);
1238 	if (!k_attr)
1239 		goto err_cancel_msg;
1240 
1241 	if (nla_put_u32(msg, OVPN_A_KEYCONF_PEER_ID, peer->id))
1242 		goto err_cancel_msg;
1243 
1244 	if (nla_put_u16(msg, OVPN_A_KEYCONF_KEY_ID, key_id))
1245 		goto err_cancel_msg;
1246 
1247 	nla_nest_end(msg, k_attr);
1248 	genlmsg_end(msg, hdr);
1249 
1250 	rcu_read_lock();
1251 	sock = rcu_dereference(peer->sock);
1252 	if (!sock) {
1253 		ret = -EINVAL;
1254 		goto err_unlock;
1255 	}
1256 	genlmsg_multicast_netns(&ovpn_nl_family, sock_net(sock->sk), msg, 0,
1257 				OVPN_NLGRP_PEERS, GFP_ATOMIC);
1258 	rcu_read_unlock();
1259 
1260 	return 0;
1261 err_unlock:
1262 	rcu_read_unlock();
1263 err_cancel_msg:
1264 	genlmsg_cancel(msg, hdr);
1265 err_free_msg:
1266 	nlmsg_free(msg);
1267 	return ret;
1268 }
1269 
1270 /**
1271  * ovpn_nl_register - perform any needed registration in the NL subsustem
1272  *
1273  * Return: 0 on success, a negative error code otherwise
1274  */
ovpn_nl_register(void)1275 int __init ovpn_nl_register(void)
1276 {
1277 	int ret = genl_register_family(&ovpn_nl_family);
1278 
1279 	if (ret) {
1280 		pr_err("ovpn: genl_register_family failed: %d\n", ret);
1281 		return ret;
1282 	}
1283 
1284 	return 0;
1285 }
1286 
1287 /**
1288  * ovpn_nl_unregister - undo any module wide netlink registration
1289  */
ovpn_nl_unregister(void)1290 void ovpn_nl_unregister(void)
1291 {
1292 	genl_unregister_family(&ovpn_nl_family);
1293 }
1294