xref: /linux/drivers/net/ovpn/netlink.c (revision c27e360545373b7aee9862a5beef3b9fb3df0c25)
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 *
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 
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 
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 
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 
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 
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 
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  */
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 	/* In a multipeer-to-multipeer setup we may have asymmetric peer IDs,
309 	 * that is peer->id might be different from peer->tx_id.
310 	 */
311 	if (attrs[OVPN_A_PEER_TX_ID])
312 		peer->tx_id = nla_get_u32(attrs[OVPN_A_PEER_TX_ID]);
313 
314 	if (attrs[OVPN_A_PEER_VPN_IPV4]) {
315 		rehash = true;
316 		peer->vpn_addrs.ipv4.s_addr =
317 			nla_get_in_addr(attrs[OVPN_A_PEER_VPN_IPV4]);
318 	}
319 
320 	if (attrs[OVPN_A_PEER_VPN_IPV6]) {
321 		rehash = true;
322 		peer->vpn_addrs.ipv6 =
323 			nla_get_in6_addr(attrs[OVPN_A_PEER_VPN_IPV6]);
324 	}
325 
326 	/* when setting the keepalive, both parameters have to be configured */
327 	if (attrs[OVPN_A_PEER_KEEPALIVE_INTERVAL] &&
328 	    attrs[OVPN_A_PEER_KEEPALIVE_TIMEOUT]) {
329 		interv = nla_get_u32(attrs[OVPN_A_PEER_KEEPALIVE_INTERVAL]);
330 		timeout = nla_get_u32(attrs[OVPN_A_PEER_KEEPALIVE_TIMEOUT]);
331 		ovpn_peer_keepalive_set(peer, interv, timeout);
332 	}
333 
334 	netdev_dbg(peer->ovpn->dev,
335 		   "modify peer id=%u tx_id=%u endpoint=%pIScp VPN-IPv4=%pI4 VPN-IPv6=%pI6c\n",
336 		   peer->id, peer->tx_id, &ss,
337 		   &peer->vpn_addrs.ipv4.s_addr, &peer->vpn_addrs.ipv6);
338 
339 	spin_unlock_bh(&peer->lock);
340 
341 	return rehash ? 1 : 0;
342 err_unlock:
343 	spin_unlock_bh(&peer->lock);
344 	return ret;
345 }
346 
347 int ovpn_nl_peer_new_doit(struct sk_buff *skb, struct genl_info *info)
348 {
349 	struct nlattr *attrs[OVPN_A_PEER_MAX + 1];
350 	struct ovpn_priv *ovpn = info->user_ptr[0];
351 	struct ovpn_socket *ovpn_sock;
352 	struct socket *sock = NULL;
353 	struct ovpn_peer *peer;
354 	u32 sockfd, peer_id;
355 	int ret;
356 
357 	if (GENL_REQ_ATTR_CHECK(info, OVPN_A_PEER))
358 		return -EINVAL;
359 
360 	ret = nla_parse_nested(attrs, OVPN_A_PEER_MAX, info->attrs[OVPN_A_PEER],
361 			       ovpn_peer_new_input_nl_policy, info->extack);
362 	if (ret)
363 		return ret;
364 
365 	ret = ovpn_nl_peer_precheck(ovpn, info, attrs);
366 	if (ret < 0)
367 		return ret;
368 
369 	if (NL_REQ_ATTR_CHECK(info->extack, info->attrs[OVPN_A_PEER], attrs,
370 			      OVPN_A_PEER_SOCKET))
371 		return -EINVAL;
372 
373 	/* in MP mode VPN IPs are required for selecting the right peer */
374 	if (ovpn->mode == OVPN_MODE_MP && !attrs[OVPN_A_PEER_VPN_IPV4] &&
375 	    !attrs[OVPN_A_PEER_VPN_IPV6]) {
376 		NL_SET_ERR_MSG_FMT_MOD(info->extack,
377 				       "VPN IP must be provided in MP mode");
378 		return -EINVAL;
379 	}
380 
381 	peer_id = nla_get_u32(attrs[OVPN_A_PEER_ID]);
382 
383 	peer = ovpn_peer_new(ovpn, peer_id);
384 	if (IS_ERR(peer)) {
385 		NL_SET_ERR_MSG_FMT_MOD(info->extack,
386 				       "cannot create new peer object for peer %u: %ld",
387 				       peer_id, PTR_ERR(peer));
388 		return PTR_ERR(peer);
389 	}
390 
391 	/* lookup the fd in the kernel table and extract the socket object */
392 	sockfd = nla_get_u32(attrs[OVPN_A_PEER_SOCKET]);
393 	/* sockfd_lookup() increases sock's refcounter */
394 	sock = sockfd_lookup(sockfd, &ret);
395 	if (!sock) {
396 		NL_SET_ERR_MSG_FMT_MOD(info->extack,
397 				       "cannot lookup peer socket (fd=%u): %d",
398 				       sockfd, ret);
399 		ret = -ENOTSOCK;
400 		goto peer_release;
401 	}
402 
403 	/* Only when using UDP as transport protocol the remote endpoint
404 	 * can be configured so that ovpn knows where to send packets to.
405 	 */
406 	if (sock->sk->sk_protocol == IPPROTO_UDP &&
407 	    !attrs[OVPN_A_PEER_REMOTE_IPV4] &&
408 	    !attrs[OVPN_A_PEER_REMOTE_IPV6]) {
409 		NL_SET_ERR_MSG_FMT_MOD(info->extack,
410 				       "missing remote IP address for UDP socket");
411 		sockfd_put(sock);
412 		ret = -EINVAL;
413 		goto peer_release;
414 	}
415 
416 	/* In case of TCP, the socket is connected to the peer and ovpn
417 	 * will just send bytes over it, without the need to specify a
418 	 * destination.
419 	 */
420 	if (sock->sk->sk_protocol == IPPROTO_TCP &&
421 	    (attrs[OVPN_A_PEER_REMOTE_IPV4] ||
422 	     attrs[OVPN_A_PEER_REMOTE_IPV6])) {
423 		NL_SET_ERR_MSG_FMT_MOD(info->extack,
424 				       "unexpected remote IP address with TCP socket");
425 		sockfd_put(sock);
426 		ret = -EINVAL;
427 		goto peer_release;
428 	}
429 
430 	ovpn_sock = ovpn_socket_new(sock, peer);
431 	/* at this point we unconditionally drop the reference to the socket:
432 	 * - in case of error, the socket has to be dropped
433 	 * - if case of success, the socket is configured and let
434 	 *   userspace own the reference, so that the latter can
435 	 *   trigger the final close()
436 	 */
437 	sockfd_put(sock);
438 	if (IS_ERR(ovpn_sock)) {
439 		NL_SET_ERR_MSG_FMT_MOD(info->extack,
440 				       "cannot encapsulate socket: %ld",
441 				       PTR_ERR(ovpn_sock));
442 		ret = -ENOTSOCK;
443 		goto peer_release;
444 	}
445 
446 	rcu_assign_pointer(peer->sock, ovpn_sock);
447 
448 	ret = ovpn_nl_peer_modify(peer, info, attrs);
449 	if (ret < 0)
450 		goto sock_release;
451 
452 	ret = ovpn_peer_add(ovpn, peer);
453 	if (ret < 0) {
454 		NL_SET_ERR_MSG_FMT_MOD(info->extack,
455 				       "cannot add new peer (id=%u) to hashtable: %d",
456 				       peer->id, ret);
457 		goto sock_release;
458 	}
459 
460 	return 0;
461 
462 sock_release:
463 	ovpn_socket_release(peer);
464 peer_release:
465 	/* For UDP, the peer is unreachable until added to the hashtables, so
466 	 * dropping the initial reference is enough. For TCP, the peer may be
467 	 * concurrently reachable via sk_user_data->peer until
468 	 * ovpn_socket_release() detaches; rely on the refcount.
469 	 */
470 	ovpn_peer_put(peer);
471 
472 	return ret;
473 }
474 
475 int ovpn_nl_peer_set_doit(struct sk_buff *skb, struct genl_info *info)
476 {
477 	struct nlattr *attrs[OVPN_A_PEER_MAX + 1];
478 	struct ovpn_priv *ovpn = info->user_ptr[0];
479 	struct ovpn_socket *sock;
480 	struct ovpn_peer *peer;
481 	u32 peer_id;
482 	int ret;
483 
484 	if (GENL_REQ_ATTR_CHECK(info, OVPN_A_PEER))
485 		return -EINVAL;
486 
487 	ret = nla_parse_nested(attrs, OVPN_A_PEER_MAX, info->attrs[OVPN_A_PEER],
488 			       ovpn_peer_set_input_nl_policy, info->extack);
489 	if (ret)
490 		return ret;
491 
492 	ret = ovpn_nl_peer_precheck(ovpn, info, attrs);
493 	if (ret < 0)
494 		return ret;
495 
496 	if (attrs[OVPN_A_PEER_SOCKET]) {
497 		NL_SET_ERR_MSG_FMT_MOD(info->extack,
498 				       "socket cannot be modified");
499 		return -EINVAL;
500 	}
501 
502 	peer_id = nla_get_u32(attrs[OVPN_A_PEER_ID]);
503 	peer = ovpn_peer_get_by_id(ovpn, peer_id);
504 	if (!peer) {
505 		NL_SET_ERR_MSG_FMT_MOD(info->extack,
506 				       "cannot find peer with id %u", peer_id);
507 		return -ENOENT;
508 	}
509 
510 	/* when using a TCP socket the remote IP is not expected */
511 	rcu_read_lock();
512 	sock = rcu_dereference(peer->sock);
513 	if (sock && sock->sk->sk_protocol == IPPROTO_TCP &&
514 	    (attrs[OVPN_A_PEER_REMOTE_IPV4] ||
515 	     attrs[OVPN_A_PEER_REMOTE_IPV6])) {
516 		rcu_read_unlock();
517 		NL_SET_ERR_MSG_FMT_MOD(info->extack,
518 				       "unexpected remote IP address with TCP socket");
519 		ovpn_peer_put(peer);
520 		return -EINVAL;
521 	}
522 	rcu_read_unlock();
523 
524 	spin_lock_bh(&ovpn->lock);
525 	ret = ovpn_nl_peer_modify(peer, info, attrs);
526 	if (ret < 0) {
527 		spin_unlock_bh(&ovpn->lock);
528 		ovpn_peer_put(peer);
529 		return ret;
530 	}
531 
532 	/* ret == 1 means that VPN IPv4/6 has been modified and rehashing
533 	 * is required
534 	 */
535 	if (ret > 0)
536 		ovpn_peer_hash_vpn_ip(peer);
537 	/* if the remote endpoint was updated, the by_transp_addr hash bucket
538 	 * also needs to be refreshed, otherwise incoming packets from the new
539 	 * remote address would fail the lockless lookup
540 	 */
541 	if (attrs[OVPN_A_PEER_REMOTE_IPV4] || attrs[OVPN_A_PEER_REMOTE_IPV6])
542 		ovpn_peer_hash_transp_addr(peer);
543 	spin_unlock_bh(&ovpn->lock);
544 	ovpn_peer_put(peer);
545 
546 	return 0;
547 }
548 
549 static int ovpn_nl_send_peer(struct sk_buff *skb, const struct genl_info *info,
550 			     const struct ovpn_peer *peer, u32 portid, u32 seq,
551 			     int flags)
552 {
553 	const struct ovpn_bind *bind;
554 	struct ovpn_socket *sock;
555 	int ret = -EMSGSIZE;
556 	struct nlattr *attr;
557 	__be16 local_port;
558 	void *hdr;
559 	int id;
560 
561 	hdr = genlmsg_put(skb, portid, seq, &ovpn_nl_family, flags,
562 			  OVPN_CMD_PEER_GET);
563 	if (!hdr)
564 		return -ENOBUFS;
565 
566 	attr = nla_nest_start(skb, OVPN_A_PEER);
567 	if (!attr)
568 		goto err;
569 
570 	rcu_read_lock();
571 	sock = rcu_dereference(peer->sock);
572 	if (!sock) {
573 		ret = -EINVAL;
574 		goto err_unlock;
575 	}
576 
577 	if (!net_eq(genl_info_net(info), sock_net(sock->sk))) {
578 		id = peernet2id_alloc(genl_info_net(info),
579 				      sock_net(sock->sk),
580 				      GFP_ATOMIC);
581 		if (nla_put_s32(skb, OVPN_A_PEER_SOCKET_NETNSID, id))
582 			goto err_unlock;
583 	}
584 	local_port = inet_sk(sock->sk)->inet_sport;
585 	rcu_read_unlock();
586 
587 	if (nla_put_u32(skb, OVPN_A_PEER_ID, peer->id))
588 		goto err;
589 
590 	if (nla_put_u32(skb, OVPN_A_PEER_TX_ID, peer->tx_id))
591 		goto err;
592 
593 	if (peer->vpn_addrs.ipv4.s_addr != htonl(INADDR_ANY))
594 		if (nla_put_in_addr(skb, OVPN_A_PEER_VPN_IPV4,
595 				    peer->vpn_addrs.ipv4.s_addr))
596 			goto err;
597 
598 	if (!ipv6_addr_equal(&peer->vpn_addrs.ipv6, &in6addr_any))
599 		if (nla_put_in6_addr(skb, OVPN_A_PEER_VPN_IPV6,
600 				     &peer->vpn_addrs.ipv6))
601 			goto err;
602 
603 	if (nla_put_u32(skb, OVPN_A_PEER_KEEPALIVE_INTERVAL,
604 			peer->keepalive_interval) ||
605 	    nla_put_u32(skb, OVPN_A_PEER_KEEPALIVE_TIMEOUT,
606 			peer->keepalive_timeout))
607 		goto err;
608 
609 	rcu_read_lock();
610 	bind = rcu_dereference(peer->bind);
611 	if (bind) {
612 		if (bind->remote.in4.sin_family == AF_INET) {
613 			if (nla_put_in_addr(skb, OVPN_A_PEER_REMOTE_IPV4,
614 					    bind->remote.in4.sin_addr.s_addr) ||
615 			    nla_put_net16(skb, OVPN_A_PEER_REMOTE_PORT,
616 					  bind->remote.in4.sin_port) ||
617 			    nla_put_in_addr(skb, OVPN_A_PEER_LOCAL_IPV4,
618 					    bind->local.ipv4.s_addr))
619 				goto err_unlock;
620 		} else if (bind->remote.in4.sin_family == AF_INET6) {
621 			if (nla_put_in6_addr(skb, OVPN_A_PEER_REMOTE_IPV6,
622 					     &bind->remote.in6.sin6_addr) ||
623 			    nla_put_u32(skb, OVPN_A_PEER_REMOTE_IPV6_SCOPE_ID,
624 					bind->remote.in6.sin6_scope_id) ||
625 			    nla_put_net16(skb, OVPN_A_PEER_REMOTE_PORT,
626 					  bind->remote.in6.sin6_port) ||
627 			    nla_put_in6_addr(skb, OVPN_A_PEER_LOCAL_IPV6,
628 					     &bind->local.ipv6))
629 				goto err_unlock;
630 		}
631 	}
632 	rcu_read_unlock();
633 
634 	if (nla_put_net16(skb, OVPN_A_PEER_LOCAL_PORT, local_port) ||
635 	    /* VPN RX stats */
636 	    nla_put_uint(skb, OVPN_A_PEER_VPN_RX_BYTES,
637 			 atomic64_read(&peer->vpn_stats.rx.bytes)) ||
638 	    nla_put_uint(skb, OVPN_A_PEER_VPN_RX_PACKETS,
639 			 atomic64_read(&peer->vpn_stats.rx.packets)) ||
640 	    /* VPN TX stats */
641 	    nla_put_uint(skb, OVPN_A_PEER_VPN_TX_BYTES,
642 			 atomic64_read(&peer->vpn_stats.tx.bytes)) ||
643 	    nla_put_uint(skb, OVPN_A_PEER_VPN_TX_PACKETS,
644 			 atomic64_read(&peer->vpn_stats.tx.packets)) ||
645 	    /* link RX stats */
646 	    nla_put_uint(skb, OVPN_A_PEER_LINK_RX_BYTES,
647 			 atomic64_read(&peer->link_stats.rx.bytes)) ||
648 	    nla_put_uint(skb, OVPN_A_PEER_LINK_RX_PACKETS,
649 			 atomic64_read(&peer->link_stats.rx.packets)) ||
650 	    /* link TX stats */
651 	    nla_put_uint(skb, OVPN_A_PEER_LINK_TX_BYTES,
652 			 atomic64_read(&peer->link_stats.tx.bytes)) ||
653 	    nla_put_uint(skb, OVPN_A_PEER_LINK_TX_PACKETS,
654 			 atomic64_read(&peer->link_stats.tx.packets)))
655 		goto err;
656 
657 	nla_nest_end(skb, attr);
658 	genlmsg_end(skb, hdr);
659 
660 	return 0;
661 err_unlock:
662 	rcu_read_unlock();
663 err:
664 	genlmsg_cancel(skb, hdr);
665 	return ret;
666 }
667 
668 int ovpn_nl_peer_get_doit(struct sk_buff *skb, struct genl_info *info)
669 {
670 	struct nlattr *attrs[OVPN_A_PEER_MAX + 1];
671 	struct ovpn_priv *ovpn = info->user_ptr[0];
672 	struct ovpn_peer *peer;
673 	struct sk_buff *msg;
674 	u32 peer_id;
675 	int ret, i;
676 
677 	if (GENL_REQ_ATTR_CHECK(info, OVPN_A_PEER))
678 		return -EINVAL;
679 
680 	ret = nla_parse_nested(attrs, OVPN_A_PEER_MAX, info->attrs[OVPN_A_PEER],
681 			       ovpn_peer_nl_policy, info->extack);
682 	if (ret)
683 		return ret;
684 
685 	if (NL_REQ_ATTR_CHECK(info->extack, info->attrs[OVPN_A_PEER], attrs,
686 			      OVPN_A_PEER_ID))
687 		return -EINVAL;
688 
689 	/* OVPN_CMD_PEER_GET expects only the PEER_ID, therefore
690 	 * ensure that the user hasn't specified any other attribute.
691 	 *
692 	 * Unfortunately this check cannot be performed via netlink
693 	 * spec/policy and must be open-coded.
694 	 */
695 	for (i = 0; i < OVPN_A_PEER_MAX + 1; i++) {
696 		if (i == OVPN_A_PEER_ID)
697 			continue;
698 
699 		if (attrs[i]) {
700 			NL_SET_ERR_MSG_FMT_MOD(info->extack,
701 					       "unexpected attribute %u", i);
702 			return -EINVAL;
703 		}
704 	}
705 
706 	peer_id = nla_get_u32(attrs[OVPN_A_PEER_ID]);
707 	peer = ovpn_peer_get_by_id(ovpn, peer_id);
708 	if (!peer) {
709 		NL_SET_ERR_MSG_FMT_MOD(info->extack,
710 				       "cannot find peer with id %u", peer_id);
711 		return -ENOENT;
712 	}
713 
714 	msg = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);
715 	if (!msg) {
716 		ret = -ENOMEM;
717 		goto err;
718 	}
719 
720 	ret = ovpn_nl_send_peer(msg, info, peer, info->snd_portid,
721 				info->snd_seq, 0);
722 	if (ret < 0) {
723 		nlmsg_free(msg);
724 		goto err;
725 	}
726 
727 	ret = genlmsg_reply(msg, info);
728 err:
729 	ovpn_peer_put(peer);
730 	return ret;
731 }
732 
733 int ovpn_nl_peer_get_dumpit(struct sk_buff *skb, struct netlink_callback *cb)
734 {
735 	const struct genl_info *info = genl_info_dump(cb);
736 	int bkt, last_idx = cb->args[1], dumped = 0;
737 	netdevice_tracker tracker;
738 	struct ovpn_priv *ovpn;
739 	struct ovpn_peer *peer;
740 
741 	ovpn = ovpn_get_dev_from_attrs(sock_net(cb->skb->sk), info, &tracker);
742 	if (IS_ERR(ovpn))
743 		return PTR_ERR(ovpn);
744 
745 	if (ovpn->mode == OVPN_MODE_P2P) {
746 		/* if we already dumped a peer it means we are done */
747 		if (last_idx)
748 			goto out;
749 
750 		rcu_read_lock();
751 		peer = rcu_dereference(ovpn->peer);
752 		if (peer) {
753 			if (ovpn_nl_send_peer(skb, info, peer,
754 					      NETLINK_CB(cb->skb).portid,
755 					      cb->nlh->nlmsg_seq,
756 					      NLM_F_MULTI) == 0)
757 				dumped++;
758 		}
759 		rcu_read_unlock();
760 	} else {
761 		rcu_read_lock();
762 		hash_for_each_rcu(ovpn->peers->by_id, bkt, peer,
763 				  hash_entry_id) {
764 			/* skip already dumped peers that were dumped by
765 			 * previous invocations
766 			 */
767 			if (last_idx > 0) {
768 				last_idx--;
769 				continue;
770 			}
771 
772 			if (ovpn_nl_send_peer(skb, info, peer,
773 					      NETLINK_CB(cb->skb).portid,
774 					      cb->nlh->nlmsg_seq,
775 					      NLM_F_MULTI) < 0)
776 				break;
777 
778 			/* count peers being dumped during this invocation */
779 			dumped++;
780 		}
781 		rcu_read_unlock();
782 	}
783 
784 out:
785 	netdev_put(ovpn->dev, &tracker);
786 
787 	/* sum up peers dumped in this message, so that at the next invocation
788 	 * we can continue from where we left
789 	 */
790 	cb->args[1] += dumped;
791 	return skb->len;
792 }
793 
794 int ovpn_nl_peer_del_doit(struct sk_buff *skb, struct genl_info *info)
795 {
796 	struct nlattr *attrs[OVPN_A_PEER_MAX + 1];
797 	struct ovpn_priv *ovpn = info->user_ptr[0];
798 	struct ovpn_peer *peer;
799 	u32 peer_id;
800 	int ret;
801 
802 	if (GENL_REQ_ATTR_CHECK(info, OVPN_A_PEER))
803 		return -EINVAL;
804 
805 	ret = nla_parse_nested(attrs, OVPN_A_PEER_MAX, info->attrs[OVPN_A_PEER],
806 			       ovpn_peer_del_input_nl_policy, info->extack);
807 	if (ret)
808 		return ret;
809 
810 	if (NL_REQ_ATTR_CHECK(info->extack, info->attrs[OVPN_A_PEER], attrs,
811 			      OVPN_A_PEER_ID))
812 		return -EINVAL;
813 
814 	peer_id = nla_get_u32(attrs[OVPN_A_PEER_ID]);
815 	peer = ovpn_peer_get_by_id(ovpn, peer_id);
816 	if (!peer) {
817 		NL_SET_ERR_MSG_FMT_MOD(info->extack,
818 				       "cannot find peer with id %u", peer_id);
819 		return -ENOENT;
820 	}
821 
822 	netdev_dbg(ovpn->dev, "del peer %u\n", peer->id);
823 	ret = ovpn_peer_del(peer, OVPN_DEL_PEER_REASON_USERSPACE);
824 	ovpn_peer_put(peer);
825 
826 	return ret;
827 }
828 
829 static int ovpn_nl_get_key_dir(struct genl_info *info, struct nlattr *key,
830 			       enum ovpn_cipher_alg cipher,
831 			       struct ovpn_key_direction *dir)
832 {
833 	struct nlattr *attrs[OVPN_A_KEYDIR_MAX + 1];
834 	int ret;
835 
836 	ret = nla_parse_nested(attrs, OVPN_A_KEYDIR_MAX, key,
837 			       ovpn_keydir_nl_policy, info->extack);
838 	if (ret)
839 		return ret;
840 
841 	switch (cipher) {
842 	case OVPN_CIPHER_ALG_AES_GCM:
843 	case OVPN_CIPHER_ALG_CHACHA20_POLY1305:
844 		if (NL_REQ_ATTR_CHECK(info->extack, key, attrs,
845 				      OVPN_A_KEYDIR_CIPHER_KEY) ||
846 		    NL_REQ_ATTR_CHECK(info->extack, key, attrs,
847 				      OVPN_A_KEYDIR_NONCE_TAIL))
848 			return -EINVAL;
849 
850 		dir->cipher_key = nla_data(attrs[OVPN_A_KEYDIR_CIPHER_KEY]);
851 		dir->cipher_key_size = nla_len(attrs[OVPN_A_KEYDIR_CIPHER_KEY]);
852 
853 		/* These algorithms require a 96bit nonce,
854 		 * Construct it by combining 4-bytes packet id and
855 		 * 8-bytes nonce-tail from userspace
856 		 */
857 		dir->nonce_tail = nla_data(attrs[OVPN_A_KEYDIR_NONCE_TAIL]);
858 		dir->nonce_tail_size = nla_len(attrs[OVPN_A_KEYDIR_NONCE_TAIL]);
859 		break;
860 	default:
861 		NL_SET_ERR_MSG_MOD(info->extack, "unsupported cipher");
862 		return -EINVAL;
863 	}
864 
865 	return 0;
866 }
867 
868 /**
869  * ovpn_nl_key_new_doit - configure a new key for the specified peer
870  * @skb: incoming netlink message
871  * @info: genetlink metadata
872  *
873  * This function allows the user to install a new key in the peer crypto
874  * state.
875  * Each peer has two 'slots', namely 'primary' and 'secondary', where
876  * keys can be installed. The key in the 'primary' slot is used for
877  * encryption, while both keys can be used for decryption by matching the
878  * key ID carried in the incoming packet.
879  *
880  * The user is responsible for rotating keys when necessary. The user
881  * may fetch peer traffic statistics via netlink in order to better
882  * identify the right time to rotate keys.
883  * The renegotiation follows these steps:
884  * 1. a new key is computed by the user and is installed in the 'secondary'
885  *    slot
886  * 2. at user discretion (usually after a predetermined time) 'primary' and
887  *    'secondary' contents are swapped and the new key starts being used for
888  *    encryption, while the old key is kept around for decryption of late
889  *    packets.
890  *
891  * Return: 0 on success or a negative error code otherwise.
892  */
893 int ovpn_nl_key_new_doit(struct sk_buff *skb, struct genl_info *info)
894 {
895 	struct nlattr *attrs[OVPN_A_KEYCONF_MAX + 1];
896 	struct ovpn_priv *ovpn = info->user_ptr[0];
897 	struct ovpn_peer_key_reset pkr;
898 	struct ovpn_peer *peer;
899 	u32 peer_id;
900 	int ret;
901 
902 	if (GENL_REQ_ATTR_CHECK(info, OVPN_A_KEYCONF))
903 		return -EINVAL;
904 
905 	ret = nla_parse_nested(attrs, OVPN_A_KEYCONF_MAX,
906 			       info->attrs[OVPN_A_KEYCONF],
907 			       ovpn_keyconf_nl_policy, info->extack);
908 	if (ret)
909 		return ret;
910 
911 	if (NL_REQ_ATTR_CHECK(info->extack, info->attrs[OVPN_A_KEYCONF], attrs,
912 			      OVPN_A_KEYCONF_PEER_ID))
913 		return -EINVAL;
914 
915 	if (NL_REQ_ATTR_CHECK(info->extack, info->attrs[OVPN_A_KEYCONF], attrs,
916 			      OVPN_A_KEYCONF_SLOT) ||
917 	    NL_REQ_ATTR_CHECK(info->extack, info->attrs[OVPN_A_KEYCONF], attrs,
918 			      OVPN_A_KEYCONF_KEY_ID) ||
919 	    NL_REQ_ATTR_CHECK(info->extack, info->attrs[OVPN_A_KEYCONF], attrs,
920 			      OVPN_A_KEYCONF_CIPHER_ALG) ||
921 	    NL_REQ_ATTR_CHECK(info->extack, info->attrs[OVPN_A_KEYCONF], attrs,
922 			      OVPN_A_KEYCONF_ENCRYPT_DIR) ||
923 	    NL_REQ_ATTR_CHECK(info->extack, info->attrs[OVPN_A_KEYCONF], attrs,
924 			      OVPN_A_KEYCONF_DECRYPT_DIR))
925 		return -EINVAL;
926 
927 	pkr.slot = nla_get_u32(attrs[OVPN_A_KEYCONF_SLOT]);
928 	pkr.key.key_id = nla_get_u32(attrs[OVPN_A_KEYCONF_KEY_ID]);
929 	pkr.key.cipher_alg = nla_get_u32(attrs[OVPN_A_KEYCONF_CIPHER_ALG]);
930 
931 	ret = ovpn_nl_get_key_dir(info, attrs[OVPN_A_KEYCONF_ENCRYPT_DIR],
932 				  pkr.key.cipher_alg, &pkr.key.encrypt);
933 	if (ret < 0)
934 		return ret;
935 
936 	ret = ovpn_nl_get_key_dir(info, attrs[OVPN_A_KEYCONF_DECRYPT_DIR],
937 				  pkr.key.cipher_alg, &pkr.key.decrypt);
938 	if (ret < 0)
939 		return ret;
940 
941 	peer_id = nla_get_u32(attrs[OVPN_A_KEYCONF_PEER_ID]);
942 	peer = ovpn_peer_get_by_id(ovpn, peer_id);
943 	if (!peer) {
944 		NL_SET_ERR_MSG_FMT_MOD(info->extack,
945 				       "no peer with id %u to set key for",
946 				       peer_id);
947 		return -ENOENT;
948 	}
949 
950 	ret = ovpn_crypto_state_reset(&peer->crypto, &pkr);
951 	if (ret < 0) {
952 		NL_SET_ERR_MSG_FMT_MOD(info->extack,
953 				       "cannot install new key for peer %u",
954 				       peer_id);
955 		goto out;
956 	}
957 
958 	netdev_dbg(ovpn->dev, "new key installed (id=%u) for peer %u\n",
959 		   pkr.key.key_id, peer_id);
960 out:
961 	ovpn_peer_put(peer);
962 	return ret;
963 }
964 
965 static int ovpn_nl_send_key(struct sk_buff *skb, const struct genl_info *info,
966 			    u32 peer_id, enum ovpn_key_slot slot,
967 			    const struct ovpn_key_config *keyconf)
968 {
969 	struct nlattr *attr;
970 	void *hdr;
971 
972 	hdr = genlmsg_put(skb, info->snd_portid, info->snd_seq, &ovpn_nl_family,
973 			  0, OVPN_CMD_KEY_GET);
974 	if (!hdr)
975 		return -ENOBUFS;
976 
977 	attr = nla_nest_start(skb, OVPN_A_KEYCONF);
978 	if (!attr)
979 		goto err;
980 
981 	if (nla_put_u32(skb, OVPN_A_KEYCONF_PEER_ID, peer_id))
982 		goto err;
983 
984 	if (nla_put_u32(skb, OVPN_A_KEYCONF_SLOT, slot) ||
985 	    nla_put_u32(skb, OVPN_A_KEYCONF_KEY_ID, keyconf->key_id) ||
986 	    nla_put_u32(skb, OVPN_A_KEYCONF_CIPHER_ALG, keyconf->cipher_alg))
987 		goto err;
988 
989 	nla_nest_end(skb, attr);
990 	genlmsg_end(skb, hdr);
991 
992 	return 0;
993 err:
994 	genlmsg_cancel(skb, hdr);
995 	return -EMSGSIZE;
996 }
997 
998 int ovpn_nl_key_get_doit(struct sk_buff *skb, struct genl_info *info)
999 {
1000 	struct nlattr *attrs[OVPN_A_KEYCONF_MAX + 1];
1001 	struct ovpn_priv *ovpn = info->user_ptr[0];
1002 	struct ovpn_key_config keyconf = { 0 };
1003 	enum ovpn_key_slot slot;
1004 	struct ovpn_peer *peer;
1005 	struct sk_buff *msg;
1006 	u32 peer_id;
1007 	int ret, i;
1008 
1009 	if (GENL_REQ_ATTR_CHECK(info, OVPN_A_KEYCONF))
1010 		return -EINVAL;
1011 
1012 	ret = nla_parse_nested(attrs, OVPN_A_KEYCONF_MAX,
1013 			       info->attrs[OVPN_A_KEYCONF],
1014 			       ovpn_keyconf_get_nl_policy, info->extack);
1015 	if (ret)
1016 		return ret;
1017 
1018 	if (NL_REQ_ATTR_CHECK(info->extack, info->attrs[OVPN_A_KEYCONF], attrs,
1019 			      OVPN_A_KEYCONF_PEER_ID))
1020 		return -EINVAL;
1021 
1022 	if (NL_REQ_ATTR_CHECK(info->extack, info->attrs[OVPN_A_KEYCONF], attrs,
1023 			      OVPN_A_KEYCONF_SLOT))
1024 		return -EINVAL;
1025 
1026 	/* OVPN_CMD_KEY_GET expects only the PEER_ID and the SLOT, therefore
1027 	 * ensure that the user hasn't specified any other attribute.
1028 	 *
1029 	 * Unfortunately this check cannot be performed via netlink
1030 	 * spec/policy and must be open-coded.
1031 	 */
1032 	for (i = 0; i < OVPN_A_KEYCONF_MAX + 1; i++) {
1033 		if (i == OVPN_A_KEYCONF_PEER_ID ||
1034 		    i == OVPN_A_KEYCONF_SLOT)
1035 			continue;
1036 
1037 		if (attrs[i]) {
1038 			NL_SET_ERR_MSG_FMT_MOD(info->extack,
1039 					       "unexpected attribute %u", i);
1040 			return -EINVAL;
1041 		}
1042 	}
1043 
1044 	peer_id = nla_get_u32(attrs[OVPN_A_KEYCONF_PEER_ID]);
1045 	peer = ovpn_peer_get_by_id(ovpn, peer_id);
1046 	if (!peer) {
1047 		NL_SET_ERR_MSG_FMT_MOD(info->extack,
1048 				       "cannot find peer with id %u", peer_id);
1049 		return -ENOENT;
1050 	}
1051 
1052 	slot = nla_get_u32(attrs[OVPN_A_KEYCONF_SLOT]);
1053 
1054 	ret = ovpn_crypto_config_get(&peer->crypto, slot, &keyconf);
1055 	if (ret < 0) {
1056 		NL_SET_ERR_MSG_FMT_MOD(info->extack,
1057 				       "cannot extract key from slot %u for peer %u",
1058 				       slot, peer_id);
1059 		goto err;
1060 	}
1061 
1062 	msg = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);
1063 	if (!msg) {
1064 		ret = -ENOMEM;
1065 		goto err;
1066 	}
1067 
1068 	ret = ovpn_nl_send_key(msg, info, peer->id, slot, &keyconf);
1069 	if (ret < 0) {
1070 		nlmsg_free(msg);
1071 		goto err;
1072 	}
1073 
1074 	ret = genlmsg_reply(msg, info);
1075 err:
1076 	ovpn_peer_put(peer);
1077 	return ret;
1078 }
1079 
1080 int ovpn_nl_key_swap_doit(struct sk_buff *skb, struct genl_info *info)
1081 {
1082 	struct nlattr *attrs[OVPN_A_KEYCONF_MAX + 1];
1083 	struct ovpn_priv *ovpn = info->user_ptr[0];
1084 	struct ovpn_peer *peer;
1085 	u32 peer_id;
1086 	int ret;
1087 
1088 	if (GENL_REQ_ATTR_CHECK(info, OVPN_A_KEYCONF))
1089 		return -EINVAL;
1090 
1091 	ret = nla_parse_nested(attrs, OVPN_A_KEYCONF_MAX,
1092 			       info->attrs[OVPN_A_KEYCONF],
1093 			       ovpn_keyconf_swap_input_nl_policy, info->extack);
1094 	if (ret)
1095 		return ret;
1096 
1097 	if (NL_REQ_ATTR_CHECK(info->extack, info->attrs[OVPN_A_KEYCONF], attrs,
1098 			      OVPN_A_KEYCONF_PEER_ID))
1099 		return -EINVAL;
1100 
1101 	peer_id = nla_get_u32(attrs[OVPN_A_KEYCONF_PEER_ID]);
1102 	peer = ovpn_peer_get_by_id(ovpn, peer_id);
1103 	if (!peer) {
1104 		NL_SET_ERR_MSG_FMT_MOD(info->extack,
1105 				       "no peer with id %u to swap keys for",
1106 				       peer_id);
1107 		return -ENOENT;
1108 	}
1109 
1110 	ovpn_crypto_key_slots_swap(&peer->crypto);
1111 	ovpn_peer_put(peer);
1112 
1113 	return 0;
1114 }
1115 
1116 int ovpn_nl_key_del_doit(struct sk_buff *skb, struct genl_info *info)
1117 {
1118 	struct nlattr *attrs[OVPN_A_KEYCONF_MAX + 1];
1119 	struct ovpn_priv *ovpn = info->user_ptr[0];
1120 	enum ovpn_key_slot slot;
1121 	struct ovpn_peer *peer;
1122 	u32 peer_id;
1123 	int ret;
1124 
1125 	if (GENL_REQ_ATTR_CHECK(info, OVPN_A_KEYCONF))
1126 		return -EINVAL;
1127 
1128 	ret = nla_parse_nested(attrs, OVPN_A_KEYCONF_MAX,
1129 			       info->attrs[OVPN_A_KEYCONF],
1130 			       ovpn_keyconf_del_input_nl_policy, info->extack);
1131 	if (ret)
1132 		return ret;
1133 
1134 	if (NL_REQ_ATTR_CHECK(info->extack, info->attrs[OVPN_A_KEYCONF], attrs,
1135 			      OVPN_A_KEYCONF_PEER_ID))
1136 		return -EINVAL;
1137 
1138 	if (NL_REQ_ATTR_CHECK(info->extack, info->attrs[OVPN_A_KEYCONF], attrs,
1139 			      OVPN_A_KEYCONF_SLOT))
1140 		return -EINVAL;
1141 
1142 	peer_id = nla_get_u32(attrs[OVPN_A_KEYCONF_PEER_ID]);
1143 	slot = nla_get_u32(attrs[OVPN_A_KEYCONF_SLOT]);
1144 
1145 	peer = ovpn_peer_get_by_id(ovpn, peer_id);
1146 	if (!peer) {
1147 		NL_SET_ERR_MSG_FMT_MOD(info->extack,
1148 				       "no peer with id %u to delete key for",
1149 				       peer_id);
1150 		return -ENOENT;
1151 	}
1152 
1153 	ovpn_crypto_key_slot_delete(&peer->crypto, slot);
1154 	ovpn_peer_put(peer);
1155 
1156 	return 0;
1157 }
1158 
1159 /**
1160  * ovpn_nl_peer_del_notify - notify userspace about peer being deleted
1161  * @peer: the peer being deleted
1162  *
1163  * Return: 0 on success or a negative error code otherwise
1164  */
1165 int ovpn_nl_peer_del_notify(struct ovpn_peer *peer)
1166 {
1167 	struct ovpn_socket *sock;
1168 	struct sk_buff *msg;
1169 	struct nlattr *attr;
1170 	int ret = -EMSGSIZE;
1171 	void *hdr;
1172 
1173 	netdev_info(peer->ovpn->dev, "deleting peer with id %u, reason %d\n",
1174 		    peer->id, peer->delete_reason);
1175 
1176 	msg = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_ATOMIC);
1177 	if (!msg)
1178 		return -ENOMEM;
1179 
1180 	hdr = genlmsg_put(msg, 0, 0, &ovpn_nl_family, 0, OVPN_CMD_PEER_DEL_NTF);
1181 	if (!hdr) {
1182 		ret = -ENOBUFS;
1183 		goto err_free_msg;
1184 	}
1185 
1186 	if (nla_put_u32(msg, OVPN_A_IFINDEX, peer->ovpn->dev->ifindex))
1187 		goto err_cancel_msg;
1188 
1189 	attr = nla_nest_start(msg, OVPN_A_PEER);
1190 	if (!attr)
1191 		goto err_cancel_msg;
1192 
1193 	if (nla_put_u32(msg, OVPN_A_PEER_DEL_REASON, peer->delete_reason))
1194 		goto err_cancel_msg;
1195 
1196 	if (nla_put_u32(msg, OVPN_A_PEER_ID, peer->id))
1197 		goto err_cancel_msg;
1198 
1199 	nla_nest_end(msg, attr);
1200 
1201 	genlmsg_end(msg, hdr);
1202 
1203 	rcu_read_lock();
1204 	sock = rcu_dereference(peer->sock);
1205 	if (!sock) {
1206 		ret = -EINVAL;
1207 		goto err_unlock;
1208 	}
1209 	genlmsg_multicast_netns(&ovpn_nl_family, sock_net(sock->sk), msg, 0,
1210 				OVPN_NLGRP_PEERS, GFP_ATOMIC);
1211 	rcu_read_unlock();
1212 
1213 	return 0;
1214 
1215 err_unlock:
1216 	rcu_read_unlock();
1217 err_cancel_msg:
1218 	genlmsg_cancel(msg, hdr);
1219 err_free_msg:
1220 	nlmsg_free(msg);
1221 	return ret;
1222 }
1223 
1224 /**
1225  * ovpn_nl_peer_float_notify - notify userspace about peer floating
1226  * @peer: the floated peer
1227  * @ss: sockaddr representing the new remote endpoint
1228  *
1229  * Return: 0 on success or a negative error code otherwise
1230  */
1231 int ovpn_nl_peer_float_notify(struct ovpn_peer *peer,
1232 			      const struct sockaddr_storage *ss)
1233 {
1234 	struct ovpn_socket *sock;
1235 	struct sockaddr_in6 *sa6;
1236 	struct sockaddr_in *sa;
1237 	struct sk_buff *msg;
1238 	struct nlattr *attr;
1239 	int ret = -EMSGSIZE;
1240 	void *hdr;
1241 
1242 	msg = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_ATOMIC);
1243 	if (!msg)
1244 		return -ENOMEM;
1245 
1246 	hdr = genlmsg_put(msg, 0, 0, &ovpn_nl_family, 0,
1247 			  OVPN_CMD_PEER_FLOAT_NTF);
1248 	if (!hdr) {
1249 		ret = -ENOBUFS;
1250 		goto err_free_msg;
1251 	}
1252 
1253 	if (nla_put_u32(msg, OVPN_A_IFINDEX, peer->ovpn->dev->ifindex))
1254 		goto err_cancel_msg;
1255 
1256 	attr = nla_nest_start(msg, OVPN_A_PEER);
1257 	if (!attr)
1258 		goto err_cancel_msg;
1259 
1260 	if (nla_put_u32(msg, OVPN_A_PEER_ID, peer->id))
1261 		goto err_cancel_msg;
1262 
1263 	if (ss->ss_family == AF_INET) {
1264 		sa = (struct sockaddr_in *)ss;
1265 		if (nla_put_in_addr(msg, OVPN_A_PEER_REMOTE_IPV4,
1266 				    sa->sin_addr.s_addr) ||
1267 		    nla_put_net16(msg, OVPN_A_PEER_REMOTE_PORT, sa->sin_port))
1268 			goto err_cancel_msg;
1269 	} else if (ss->ss_family == AF_INET6) {
1270 		sa6 = (struct sockaddr_in6 *)ss;
1271 		if (nla_put_in6_addr(msg, OVPN_A_PEER_REMOTE_IPV6,
1272 				     &sa6->sin6_addr) ||
1273 		    nla_put_u32(msg, OVPN_A_PEER_REMOTE_IPV6_SCOPE_ID,
1274 				sa6->sin6_scope_id) ||
1275 		    nla_put_net16(msg, OVPN_A_PEER_REMOTE_PORT, sa6->sin6_port))
1276 			goto err_cancel_msg;
1277 	} else {
1278 		ret = -EAFNOSUPPORT;
1279 		goto err_cancel_msg;
1280 	}
1281 
1282 	nla_nest_end(msg, attr);
1283 	genlmsg_end(msg, hdr);
1284 
1285 	rcu_read_lock();
1286 	sock = rcu_dereference(peer->sock);
1287 	if (!sock) {
1288 		ret = -EINVAL;
1289 		goto err_unlock;
1290 	}
1291 	genlmsg_multicast_netns(&ovpn_nl_family, sock_net(sock->sk), msg,
1292 				0, OVPN_NLGRP_PEERS, GFP_ATOMIC);
1293 	rcu_read_unlock();
1294 
1295 	return 0;
1296 
1297 err_unlock:
1298 	rcu_read_unlock();
1299 err_cancel_msg:
1300 	genlmsg_cancel(msg, hdr);
1301 err_free_msg:
1302 	nlmsg_free(msg);
1303 	return ret;
1304 }
1305 
1306 /**
1307  * ovpn_nl_key_swap_notify - notify userspace peer's key must be renewed
1308  * @peer: the peer whose key needs to be renewed
1309  * @key_id: the ID of the key that needs to be renewed
1310  *
1311  * Return: 0 on success or a negative error code otherwise
1312  */
1313 int ovpn_nl_key_swap_notify(struct ovpn_peer *peer, u8 key_id)
1314 {
1315 	struct ovpn_socket *sock;
1316 	struct nlattr *k_attr;
1317 	struct sk_buff *msg;
1318 	int ret = -EMSGSIZE;
1319 	void *hdr;
1320 
1321 	netdev_info(peer->ovpn->dev, "peer with id %u must rekey - primary key unusable.\n",
1322 		    peer->id);
1323 
1324 	msg = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_ATOMIC);
1325 	if (!msg)
1326 		return -ENOMEM;
1327 
1328 	hdr = genlmsg_put(msg, 0, 0, &ovpn_nl_family, 0, OVPN_CMD_KEY_SWAP_NTF);
1329 	if (!hdr) {
1330 		ret = -ENOBUFS;
1331 		goto err_free_msg;
1332 	}
1333 
1334 	if (nla_put_u32(msg, OVPN_A_IFINDEX, peer->ovpn->dev->ifindex))
1335 		goto err_cancel_msg;
1336 
1337 	k_attr = nla_nest_start(msg, OVPN_A_KEYCONF);
1338 	if (!k_attr)
1339 		goto err_cancel_msg;
1340 
1341 	if (nla_put_u32(msg, OVPN_A_KEYCONF_PEER_ID, peer->id))
1342 		goto err_cancel_msg;
1343 
1344 	if (nla_put_u16(msg, OVPN_A_KEYCONF_KEY_ID, key_id))
1345 		goto err_cancel_msg;
1346 
1347 	nla_nest_end(msg, k_attr);
1348 	genlmsg_end(msg, hdr);
1349 
1350 	rcu_read_lock();
1351 	sock = rcu_dereference(peer->sock);
1352 	if (!sock) {
1353 		ret = -EINVAL;
1354 		goto err_unlock;
1355 	}
1356 	genlmsg_multicast_netns(&ovpn_nl_family, sock_net(sock->sk), msg, 0,
1357 				OVPN_NLGRP_PEERS, GFP_ATOMIC);
1358 	rcu_read_unlock();
1359 
1360 	return 0;
1361 err_unlock:
1362 	rcu_read_unlock();
1363 err_cancel_msg:
1364 	genlmsg_cancel(msg, hdr);
1365 err_free_msg:
1366 	nlmsg_free(msg);
1367 	return ret;
1368 }
1369 
1370 /**
1371  * ovpn_nl_register - perform any needed registration in the NL subsustem
1372  *
1373  * Return: 0 on success, a negative error code otherwise
1374  */
1375 int __init ovpn_nl_register(void)
1376 {
1377 	int ret = genl_register_family(&ovpn_nl_family);
1378 
1379 	if (ret) {
1380 		pr_err("ovpn: genl_register_family failed: %d\n", ret);
1381 		return ret;
1382 	}
1383 
1384 	return 0;
1385 }
1386 
1387 /**
1388  * ovpn_nl_unregister - undo any module wide netlink registration
1389  */
1390 void ovpn_nl_unregister(void)
1391 {
1392 	genl_unregister_family(&ovpn_nl_family);
1393 }
1394