xref: /freebsd/sys/net/if_ovpn.c (revision 17c9ac457cf16c1251afa7364bc47ed52ec29057)
1 /*-
2  * SPDX-License-Identifier: BSD-2-Clause
3  *
4  * Copyright (c) 2021-2022 Rubicon Communications, LLC (Netgate)
5  *
6  * Redistribution and use in source and binary forms, with or without
7  * modification, are permitted provided that the following conditions
8  * are met:
9  * 1. Redistributions of source code must retain the above copyright
10  *    notice, this list of conditions and the following disclaimer.
11  * 2. Redistributions in binary form must reproduce the above copyright
12  *    notice, this list of conditions and the following disclaimer in the
13  *    documentation and/or other materials provided with the distribution.
14  *
15  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
16  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
17  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
18  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
19  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
20  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
21  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
22  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
23  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
24  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
25  * SUCH DAMAGE.
26  *
27  */
28 #include "opt_inet.h"
29 #include "opt_inet6.h"
30 
31 #include <sys/param.h>
32 #include <sys/systm.h>
33 #include <sys/buf_ring.h>
34 #include <sys/epoch.h>
35 #include <sys/file.h>
36 #include <sys/filedesc.h>
37 #include <sys/kernel.h>
38 #include <sys/malloc.h>
39 #include <sys/mbuf.h>
40 #include <sys/module.h>
41 #include <sys/nv.h>
42 #include <sys/priv.h>
43 #include <sys/protosw.h>
44 #include <sys/rmlock.h>
45 #include <sys/sdt.h>
46 #include <sys/smp.h>
47 #include <sys/socket.h>
48 #include <sys/socketvar.h>
49 #include <sys/sockio.h>
50 #include <sys/sysctl.h>
51 #include <sys/time.h>
52 
53 #include <machine/atomic.h>
54 
55 #include <net/bpf.h>
56 #include <net/if.h>
57 #include <net/if_clone.h>
58 #include <net/if_types.h>
59 #include <net/if_var.h>
60 #include <net/if_private.h>
61 #include <net/netisr.h>
62 #include <net/route/nhop.h>
63 
64 #include <netinet/in.h>
65 #include <netinet/in_fib.h>
66 #include <netinet/ip.h>
67 #include <netinet/ip6.h>
68 #include <netinet/ip_var.h>
69 #include <netinet/udp.h>
70 #include <netinet/udp_var.h>
71 
72 #include <netinet6/ip6_var.h>
73 #include <netinet6/in6_fib.h>
74 
75 #include <machine/in_cksum.h>
76 
77 #include <opencrypto/cryptodev.h>
78 
79 #include "if_ovpn.h"
80 
81 struct ovpn_kkey_dir {
82 	int			refcount;
83 	uint8_t			key[32];
84 	uint8_t			keylen;
85 	uint8_t			nonce[8];
86 	uint8_t			noncelen;
87 	enum ovpn_key_cipher	cipher;
88 	crypto_session_t	cryptoid;
89 
90 	struct mtx		replay_mtx;
91 	/*
92 	 * Last seen gapless sequence number. New rx seq numbers must be
93 	 * strictly higher than this.
94 	 */
95 	uint32_t		rx_seq;
96 	uint64_t		tx_seq;
97 
98 	/* Seen packets, relative to rx_seq. bit(0) will always be 0. */
99 	uint64_t		rx_window;
100 };
101 
102 struct ovpn_kkey {
103 	struct ovpn_kkey_dir	*encrypt;
104 	struct ovpn_kkey_dir	*decrypt;
105 	uint8_t			 keyid;
106 	uint32_t		 peerid;
107 };
108 
109 struct ovpn_keepalive {
110 	uint32_t	interval;
111 	uint32_t	timeout;
112 };
113 
114 struct ovpn_wire_header {
115 	uint32_t	 opcode; /* opcode, key id, peer id */
116 	uint32_t	 seq;
117 	uint8_t		 auth_tag[16];
118 };
119 
120 struct ovpn_peer_counters {
121 	uint64_t	pkt_in;
122 	uint64_t	pkt_out;
123 	uint64_t	bytes_in;
124 	uint64_t	bytes_out;
125 };
126 #define OVPN_PEER_COUNTER_SIZE (sizeof(struct ovpn_peer_counters)/sizeof(uint64_t))
127 
128 struct ovpn_notification {
129 	enum ovpn_notif_type	type;
130 	uint32_t		peerid;
131 
132 	/* Delete notification */
133 	enum ovpn_del_reason	del_reason;
134 	struct ovpn_peer_counters	counters;
135 };
136 
137 struct ovpn_softc;
138 
139 struct ovpn_kpeer {
140 	RB_ENTRY(ovpn_kpeer)	 tree;
141 	int			 refcount;
142 	uint32_t		 peerid;
143 
144 	struct ovpn_softc	*sc;
145 	struct sockaddr_storage	 local;
146 	struct sockaddr_storage	 remote;
147 
148 	struct in_addr		 vpn4;
149 	struct in6_addr		 vpn6;
150 
151 	struct ovpn_kkey	 keys[2];
152 
153 	enum ovpn_del_reason	 del_reason;
154 	struct ovpn_keepalive	 keepalive;
155 	uint32_t		*last_active;
156 	struct callout		 ping_send;
157 	struct callout		 ping_rcv;
158 
159 	counter_u64_t		 counters[OVPN_PEER_COUNTER_SIZE];
160 };
161 
162 struct ovpn_counters {
163 	uint64_t	lost_ctrl_pkts_in;
164 	uint64_t	lost_ctrl_pkts_out;
165 	uint64_t	lost_data_pkts_in;
166 	uint64_t	lost_data_pkts_out;
167 	uint64_t	nomem_data_pkts_in;
168 	uint64_t	nomem_data_pkts_out;
169 	uint64_t	received_ctrl_pkts;
170 	uint64_t	received_data_pkts;
171 	uint64_t	sent_ctrl_pkts;
172 	uint64_t	sent_data_pkts;
173 
174 	uint64_t	transport_bytes_sent;
175 	uint64_t	transport_bytes_received;
176 	uint64_t	tunnel_bytes_sent;
177 	uint64_t	tunnel_bytes_received;
178 };
179 #define OVPN_COUNTER_SIZE (sizeof(struct ovpn_counters)/sizeof(uint64_t))
180 
181 RB_HEAD(ovpn_kpeers, ovpn_kpeer);
182 
183 struct ovpn_softc {
184 	int			 refcount;
185 	struct rmlock		 lock;
186 	struct ifnet		*ifp;
187 	struct socket		*so;
188 	int			 peercount;
189 	struct ovpn_kpeers	 peers;
190 
191 	/* Pending notification */
192 	struct buf_ring		*notifring;
193 
194 	counter_u64_t 		 counters[OVPN_COUNTER_SIZE];
195 
196 	struct epoch_context	 epoch_ctx;
197 };
198 
199 static struct ovpn_kpeer *ovpn_find_peer(struct ovpn_softc *, uint32_t);
200 static bool ovpn_udp_input(struct mbuf *, int, struct inpcb *,
201     const struct sockaddr *, void *);
202 static int ovpn_transmit_to_peer(struct ifnet *, struct mbuf *,
203     struct ovpn_kpeer *, struct rm_priotracker *);
204 static int ovpn_encap(struct ovpn_softc *, uint32_t, struct mbuf *);
205 static int ovpn_get_af(struct mbuf *);
206 static void ovpn_free_kkey_dir(struct ovpn_kkey_dir *);
207 static bool ovpn_check_replay(struct ovpn_kkey_dir *, uint32_t);
208 static int ovpn_peer_compare(struct ovpn_kpeer *, struct ovpn_kpeer *);
209 
210 static RB_PROTOTYPE(ovpn_kpeers, ovpn_kpeer, tree, ovpn_peer_compare);
211 static RB_GENERATE(ovpn_kpeers, ovpn_kpeer, tree, ovpn_peer_compare);
212 
213 #define OVPN_MTU_MIN		576
214 #define OVPN_MTU_MAX		(IP_MAXPACKET - sizeof(struct ip) - \
215     sizeof(struct udphdr) - sizeof(struct ovpn_wire_header))
216 
217 #define OVPN_OP_DATA_V2		0x09
218 #define OVPN_OP_SHIFT		3
219 #define OVPN_SEQ_ROTATE		0x80000000
220 
221 VNET_DEFINE_STATIC(struct if_clone *, ovpn_cloner);
222 #define	V_ovpn_cloner	VNET(ovpn_cloner)
223 
224 #define OVPN_RLOCK_TRACKER	struct rm_priotracker _ovpn_lock_tracker; \
225     struct rm_priotracker *_ovpn_lock_trackerp = &_ovpn_lock_tracker
226 #define OVPN_RLOCK(sc)		rm_rlock(&(sc)->lock, _ovpn_lock_trackerp)
227 #define OVPN_RUNLOCK(sc)	rm_runlock(&(sc)->lock, _ovpn_lock_trackerp)
228 #define OVPN_WLOCK(sc)		rm_wlock(&(sc)->lock)
229 #define OVPN_WUNLOCK(sc)	rm_wunlock(&(sc)->lock)
230 #define OVPN_ASSERT(sc)		rm_assert(&(sc)->lock, RA_LOCKED)
231 #define OVPN_RASSERT(sc)	rm_assert(&(sc)->lock, RA_RLOCKED)
232 #define OVPN_WASSERT(sc)	rm_assert(&(sc)->lock, RA_WLOCKED)
233 #define OVPN_UNLOCK_ASSERT(sc)	rm_assert(&(sc)->lock, RA_UNLOCKED)
234 
235 #define OVPN_COUNTER(sc, name) \
236 	((sc)->counters[offsetof(struct ovpn_counters, name)/sizeof(uint64_t)])
237 #define OVPN_PEER_COUNTER(peer, name) \
238 	((peer)->counters[offsetof(struct ovpn_peer_counters, name) / \
239 	 sizeof(uint64_t)])
240 
241 #define OVPN_COUNTER_ADD(sc, name, val)	\
242 	counter_u64_add(OVPN_COUNTER(sc, name), val)
243 #define OVPN_PEER_COUNTER_ADD(p, name, val)	\
244 	counter_u64_add(OVPN_PEER_COUNTER(p, name), val)
245 
246 #define TO_IN(x)		((struct sockaddr_in *)(x))
247 #define TO_IN6(x)		((struct sockaddr_in6 *)(x))
248 
249 SDT_PROVIDER_DEFINE(if_ovpn);
250 SDT_PROBE_DEFINE1(if_ovpn, tx, transmit, start, "struct mbuf *");
251 SDT_PROBE_DEFINE2(if_ovpn, tx, route, ip4, "struct in_addr *", "struct ovpn_kpeer *");
252 SDT_PROBE_DEFINE2(if_ovpn, tx, route, ip6, "struct in6_addr *", "struct ovpn_kpeer *");
253 
254 static const char ovpnname[] = "ovpn";
255 static const char ovpngroupname[] = "openvpn";
256 
257 static MALLOC_DEFINE(M_OVPN, ovpnname, "OpenVPN DCO Interface");
258 #define	MTAG_OVPN_LOOP		0x6f76706e /* ovpn */
259 
260 SYSCTL_DECL(_net_link);
261 static SYSCTL_NODE(_net_link, IFT_OTHER, openvpn, CTLFLAG_RW | CTLFLAG_MPSAFE, 0,
262     "OpenVPN DCO Interface");
263 VNET_DEFINE_STATIC(int, replay_protection) = 0;
264 #define	V_replay_protection	VNET(replay_protection)
265 SYSCTL_INT(_net_link_openvpn, OID_AUTO, replay_protection, CTLFLAG_VNET | CTLFLAG_RW,
266     &VNET_NAME(replay_protection), 0, "Validate sequence numbers");
267 
268 VNET_DEFINE_STATIC(int, async_crypto);
269 #define	V_async_crypto		VNET(async_crypto)
270 SYSCTL_INT(_net_link_openvpn, OID_AUTO, async_crypto,
271 	CTLFLAG_VNET | CTLFLAG_RW, &VNET_NAME(async_crypto), 0,
272 	"Use asynchronous mode to parallelize crypto jobs.");
273 
274 VNET_DEFINE_STATIC(int, async_netisr_queue);
275 #define	V_async_netisr_queue		VNET(async_netisr_queue)
276 SYSCTL_INT(_net_link_openvpn, OID_AUTO, netisr_queue,
277 	CTLFLAG_VNET | CTLFLAG_RW, &VNET_NAME(async_netisr_queue), 0,
278 	"Use netisr_queue() rather than netisr_dispatch().");
279 
280 static int
ovpn_peer_compare(struct ovpn_kpeer * a,struct ovpn_kpeer * b)281 ovpn_peer_compare(struct ovpn_kpeer *a, struct ovpn_kpeer *b)
282 {
283 	return (a->peerid - b->peerid);
284 }
285 
286 static struct ovpn_kpeer *
ovpn_find_peer(struct ovpn_softc * sc,uint32_t peerid)287 ovpn_find_peer(struct ovpn_softc *sc, uint32_t peerid)
288 {
289 	struct ovpn_kpeer p;
290 
291 	OVPN_ASSERT(sc);
292 
293 	p.peerid = peerid;
294 
295 	return (RB_FIND(ovpn_kpeers, &sc->peers, &p));
296 }
297 
298 static struct ovpn_kpeer *
ovpn_find_only_peer(struct ovpn_softc * sc)299 ovpn_find_only_peer(struct ovpn_softc *sc)
300 {
301 	OVPN_ASSERT(sc);
302 
303 	return (RB_ROOT(&sc->peers));
304 }
305 
306 static uint16_t
ovpn_get_port(struct sockaddr_storage * s)307 ovpn_get_port(struct sockaddr_storage *s)
308 {
309 	switch (s->ss_family) {
310 	case AF_INET: {
311 		struct sockaddr_in *in = (struct sockaddr_in *)s;
312 		return (in->sin_port);
313 	}
314 	case AF_INET6: {
315 		struct sockaddr_in6 *in6 = (struct sockaddr_in6 *)s;
316 		return (in6->sin6_port);
317 	}
318 	default:
319 		panic("Unsupported address family %d", s->ss_family);
320 	}
321 }
322 
323 static int
ovpn_nvlist_to_sockaddr(const nvlist_t * nvl,struct sockaddr_storage * sa)324 ovpn_nvlist_to_sockaddr(const nvlist_t *nvl, struct sockaddr_storage *sa)
325 {
326 	int af;
327 
328 	if (! nvlist_exists_number(nvl, "af"))
329 		return (EINVAL);
330 	if (! nvlist_exists_binary(nvl, "address"))
331 		return (EINVAL);
332 	if (! nvlist_exists_number(nvl, "port"))
333 		return (EINVAL);
334 
335 	af = nvlist_get_number(nvl, "af");
336 
337 	switch (af) {
338 #ifdef INET
339 	case AF_INET: {
340 		struct sockaddr_in *in = (struct sockaddr_in *)sa;
341 		size_t len;
342 		const void *addr = nvlist_get_binary(nvl, "address", &len);
343 		in->sin_family = af;
344 		if (len != sizeof(in->sin_addr))
345 			return (EINVAL);
346 
347 		memcpy(&in->sin_addr, addr, sizeof(in->sin_addr));
348 		in->sin_port = nvlist_get_number(nvl, "port");
349 		break;
350 	}
351 #endif
352 #ifdef INET6
353 	case AF_INET6: {
354 		struct sockaddr_in6 *in6 = (struct sockaddr_in6 *)sa;
355 		size_t len;
356 		const void *addr = nvlist_get_binary(nvl, "address", &len);
357 		in6->sin6_family = af;
358 		if (len != sizeof(in6->sin6_addr))
359 			return (EINVAL);
360 
361 		memcpy(&in6->sin6_addr, addr, sizeof(in6->sin6_addr));
362 		in6->sin6_port = nvlist_get_number(nvl, "port");
363 		break;
364 	}
365 #endif
366 	default:
367 		return (EINVAL);
368 	}
369 
370 	return (0);
371 }
372 
373 static bool
ovpn_has_peers(struct ovpn_softc * sc)374 ovpn_has_peers(struct ovpn_softc *sc)
375 {
376 	OVPN_ASSERT(sc);
377 
378 	return (sc->peercount > 0);
379 }
380 
381 static void
ovpn_rele_so(struct ovpn_softc * sc)382 ovpn_rele_so(struct ovpn_softc *sc)
383 {
384 	bool has_peers;
385 
386 	OVPN_WASSERT(sc);
387 
388 	if (sc->so == NULL)
389 		return;
390 
391 	has_peers = ovpn_has_peers(sc);
392 
393 	if (! has_peers) {
394 		MPASS(sc->peercount == 0);
395 	} else {
396 		MPASS(sc->peercount > 0);
397 	}
398 }
399 
400 static void
ovpn_notify_del_peer(struct ovpn_softc * sc,struct ovpn_kpeer * peer)401 ovpn_notify_del_peer(struct ovpn_softc *sc, struct ovpn_kpeer *peer)
402 {
403 	struct ovpn_notification *n;
404 
405 	OVPN_WASSERT(sc);
406 
407 	n = malloc(sizeof(*n), M_OVPN, M_NOWAIT);
408 	if (n == NULL)
409 		return;
410 
411 	n->peerid = peer->peerid;
412 	n->type = OVPN_NOTIF_DEL_PEER;
413 	n->del_reason = peer->del_reason;
414 
415 	n->counters.pkt_in = counter_u64_fetch(OVPN_PEER_COUNTER(peer, pkt_in));
416 	n->counters.pkt_out = counter_u64_fetch(OVPN_PEER_COUNTER(peer, pkt_out));
417 	n->counters.bytes_in = counter_u64_fetch(OVPN_PEER_COUNTER(peer, bytes_in));
418 	n->counters.bytes_out = counter_u64_fetch(OVPN_PEER_COUNTER(peer, bytes_out));
419 
420 	if (buf_ring_enqueue(sc->notifring, n) != 0) {
421 		free(n, M_OVPN);
422 	} else if (sc->so != NULL) {
423 		/* Wake up userspace */
424 		sc->so->so_error = EAGAIN;
425 		sorwakeup(sc->so);
426 		sowwakeup(sc->so);
427 	}
428 }
429 
430 static void
ovpn_notify_key_rotation(struct ovpn_softc * sc,struct ovpn_kpeer * peer)431 ovpn_notify_key_rotation(struct ovpn_softc *sc, struct ovpn_kpeer *peer)
432 {
433 	struct ovpn_notification *n;
434 
435 	n = malloc(sizeof(*n), M_OVPN, M_NOWAIT | M_ZERO);
436 	if (n == NULL)
437 		return;
438 
439 	n->peerid = peer->peerid;
440 	n->type = OVPN_NOTIF_ROTATE_KEY;
441 
442 	if (buf_ring_enqueue(sc->notifring, n) != 0) {
443 		free(n, M_OVPN);
444 	} else if (sc->so != NULL) {
445 		/* Wake up userspace */
446 		sc->so->so_error = EAGAIN;
447 		sorwakeup(sc->so);
448 		sowwakeup(sc->so);
449 	}
450 }
451 
452 static void
ovpn_peer_release_ref(struct ovpn_kpeer * peer,bool locked)453 ovpn_peer_release_ref(struct ovpn_kpeer *peer, bool locked)
454 {
455 	struct ovpn_softc *sc;
456 
457 	CURVNET_ASSERT_SET();
458 
459 	atomic_add_int(&peer->refcount, -1);
460 
461 	if (atomic_load_int(&peer->refcount) > 0)
462 		return;
463 
464 	sc = peer->sc;
465 
466 	if (! locked) {
467 		OVPN_WLOCK(sc);
468 
469 		/* Might have changed before we acquired the lock. */
470 		if (atomic_load_int(&peer->refcount) > 0) {
471 			OVPN_WUNLOCK(sc);
472 			return;
473 		}
474 	}
475 
476 	OVPN_ASSERT(sc);
477 
478 	/* The peer should have been removed from the list already. */
479 	MPASS(ovpn_find_peer(sc, peer->peerid) == NULL);
480 
481 	ovpn_notify_del_peer(sc, peer);
482 
483 	for (int i = 0; i < 2; i++) {
484 		ovpn_free_kkey_dir(peer->keys[i].encrypt);
485 		ovpn_free_kkey_dir(peer->keys[i].decrypt);
486 	}
487 
488 	ovpn_rele_so(sc);
489 
490 	callout_stop(&peer->ping_send);
491 	callout_stop(&peer->ping_rcv);
492 	uma_zfree_pcpu(pcpu_zone_4, peer->last_active);
493 	free(peer, M_OVPN);
494 
495 	if (! locked)
496 		OVPN_WUNLOCK(sc);
497 }
498 
499 static int
ovpn_new_peer(struct ifnet * ifp,const nvlist_t * nvl)500 ovpn_new_peer(struct ifnet *ifp, const nvlist_t *nvl)
501 {
502 #ifdef INET6
503 	struct epoch_tracker et;
504 #endif
505 	struct sockaddr_storage remote;
506 	struct ovpn_kpeer *peer = NULL;
507 	struct file *fp = NULL;
508 	struct ovpn_softc *sc = ifp->if_softc;
509 	struct thread *td = curthread;
510 	struct socket *so = NULL;
511 	int fd;
512 	uint32_t peerid;
513 	int ret = 0;
514 	bool setcb = false;
515 
516 	if (nvl == NULL)
517 		return (EINVAL);
518 
519 	if (! nvlist_exists_number(nvl, "peerid"))
520 		return (EINVAL);
521 
522 	if (! nvlist_exists_number(nvl, "fd"))
523 		return (EINVAL);
524 
525 	if (! nvlist_exists_nvlist(nvl, "remote"))
526 		return (EINVAL);
527 
528 	peerid = nvlist_get_number(nvl, "peerid");
529 
530 	ret = ovpn_nvlist_to_sockaddr(nvlist_get_nvlist(nvl, "remote"),
531 	    &remote);
532 	if (ret != 0)
533 		return (ret);
534 
535 	fd = nvlist_get_number(nvl, "fd");
536 
537 	/* Look up the userspace process and use the fd to find the socket. */
538 	ret = getsock(td, fd, &cap_connect_rights, &fp);
539 	if (ret != 0)
540 		return (ret);
541 
542 	so = fp->f_data;
543 
544 	peer = malloc(sizeof(*peer), M_OVPN, M_WAITOK | M_ZERO);
545 	peer->peerid = peerid;
546 	peer->sc = sc;
547 	peer->refcount = 1;
548 	peer->last_active = uma_zalloc_pcpu(pcpu_zone_4, M_WAITOK | M_ZERO);
549 	COUNTER_ARRAY_ALLOC(peer->counters, OVPN_PEER_COUNTER_SIZE, M_WAITOK);
550 
551 	if (nvlist_exists_binary(nvl, "vpn_ipv4")) {
552 		size_t len;
553 		const void *addr = nvlist_get_binary(nvl, "vpn_ipv4", &len);
554 		if (len != sizeof(peer->vpn4)) {
555 			ret = EINVAL;
556 			goto error;
557 		}
558 		memcpy(&peer->vpn4, addr, len);
559 	}
560 
561 	if (nvlist_exists_binary(nvl, "vpn_ipv6")) {
562 		size_t len;
563 		const void *addr = nvlist_get_binary(nvl, "vpn_ipv6", &len);
564 		if (len != sizeof(peer->vpn6)) {
565 			ret = EINVAL;
566 			goto error;
567 		}
568 		memcpy(&peer->vpn6, addr, len);
569 	}
570 
571 	callout_init_rm(&peer->ping_send, &sc->lock, CALLOUT_SHAREDLOCK);
572 	callout_init_rm(&peer->ping_rcv, &sc->lock, 0);
573 
574 	peer->local.ss_len = sizeof(peer->local);
575 	ret = sosockaddr(so, (struct sockaddr *)&peer->local);
576 	if (ret)
577 		goto error;
578 
579 	if (ovpn_get_port(&peer->local) == 0) {
580 		ret = EINVAL;
581 		goto error;
582 	}
583 	if (peer->local.ss_family != remote.ss_family) {
584 		ret = EINVAL;
585 		goto error;
586 	}
587 
588 	memcpy(&peer->remote, &remote, sizeof(remote));
589 
590 	if (peer->local.ss_family == AF_INET6 &&
591 	    IN6_IS_ADDR_V4MAPPED(&TO_IN6(&peer->remote)->sin6_addr)) {
592 		/* V4 mapped address, so treat this as v4, not v6. */
593 		in6_sin6_2_sin_in_sock((struct sockaddr *)&peer->local);
594 		in6_sin6_2_sin_in_sock((struct sockaddr *)&peer->remote);
595 	}
596 
597 #ifdef INET6
598 	if (peer->local.ss_family == AF_INET6 &&
599 	    IN6_IS_ADDR_UNSPECIFIED(&TO_IN6(&peer->local)->sin6_addr)) {
600 		NET_EPOCH_ENTER(et);
601 		ret = in6_selectsrc_addr(curthread->td_proc->p_fibnum,
602 		    &TO_IN6(&peer->remote)->sin6_addr,
603 		    0, NULL, &TO_IN6(&peer->local)->sin6_addr, NULL);
604 		NET_EPOCH_EXIT(et);
605 		if (ret != 0) {
606 			goto error;
607 		}
608 	}
609 #endif
610 	OVPN_WLOCK(sc);
611 
612 	/* Disallow peer id re-use. */
613 	if (ovpn_find_peer(sc, peerid) != NULL) {
614 		ret = EEXIST;
615 		goto error_locked;
616 	}
617 
618 	/* Make sure this is really a UDP socket. */
619 	if (so->so_type != SOCK_DGRAM || so->so_proto->pr_type != SOCK_DGRAM) {
620 		ret = EPROTOTYPE;
621 		goto error_locked;
622 	}
623 
624 	/* Must be the same socket as for other peers on this interface. */
625 	if (sc->so != NULL && so != sc->so)
626 		goto error_locked;
627 
628 	if (sc->so == NULL) {
629 		sc->so = so;
630 		/*
631 		 * Maintain one extra ref so the socket doesn't go away until
632 		 * we're destroying the ifp.
633 		 */
634 		soref(sc->so);
635 		setcb = true;
636 	}
637 
638 	/* Insert the peer into the list. */
639 	RB_INSERT(ovpn_kpeers, &sc->peers, peer);
640 	sc->peercount++;
641 
642 	OVPN_WUNLOCK(sc);
643 
644 	if (setcb) {
645 		ret = udp_set_kernel_tunneling(sc->so, ovpn_udp_input, NULL, sc);
646 		MPASS(ret == 0);
647 	}
648 
649 	goto done;
650 
651 error_locked:
652 	OVPN_WUNLOCK(sc);
653 error:
654 	COUNTER_ARRAY_FREE(peer->counters, OVPN_PEER_COUNTER_SIZE);
655 	uma_zfree_pcpu(pcpu_zone_4, peer->last_active);
656 	free(peer, M_OVPN);
657 done:
658 	if (fp != NULL)
659 		fdrop(fp, td);
660 
661 	return (ret);
662 }
663 
664 static int
_ovpn_del_peer(struct ovpn_softc * sc,struct ovpn_kpeer * peer)665 _ovpn_del_peer(struct ovpn_softc *sc, struct ovpn_kpeer *peer)
666 {
667 	struct ovpn_kpeer *tmp __diagused;
668 
669 	OVPN_WASSERT(sc);
670 	CURVNET_ASSERT_SET();
671 
672 	MPASS(RB_FIND(ovpn_kpeers, &sc->peers, peer) == peer);
673 
674 	tmp = RB_REMOVE(ovpn_kpeers, &sc->peers, peer);
675 	MPASS(tmp != NULL);
676 
677 	sc->peercount--;
678 
679 	ovpn_peer_release_ref(peer, true);
680 
681 	return (0);
682 }
683 
684 static int
ovpn_del_peer(struct ifnet * ifp,nvlist_t * nvl)685 ovpn_del_peer(struct ifnet *ifp, nvlist_t *nvl)
686 {
687 	struct ovpn_softc *sc = ifp->if_softc;
688 	struct ovpn_kpeer *peer;
689 	uint32_t peerid;
690 	int ret;
691 
692 	OVPN_WASSERT(sc);
693 
694 	if (nvl == NULL)
695 		return (EINVAL);
696 
697 	if (! nvlist_exists_number(nvl, "peerid"))
698 		return (EINVAL);
699 
700 	peerid = nvlist_get_number(nvl, "peerid");
701 
702 	peer = ovpn_find_peer(sc, peerid);
703 	if (peer == NULL)
704 		return (ENOENT);
705 
706 	peer->del_reason = OVPN_DEL_REASON_REQUESTED;
707 	ret = _ovpn_del_peer(sc, peer);
708 
709 	return (ret);
710 }
711 
712 static int
ovpn_create_kkey_dir(struct ovpn_kkey_dir ** kdirp,const nvlist_t * nvl)713 ovpn_create_kkey_dir(struct ovpn_kkey_dir **kdirp,
714     const nvlist_t *nvl)
715 {
716 	struct crypto_session_params csp;
717 	struct ovpn_kkey_dir *kdir;
718 	const char *ciphername;
719 	enum ovpn_key_cipher cipher;
720 	const void *key, *iv;
721 	size_t keylen = 0, ivlen = 0;
722 	int error;
723 
724 	if (! nvlist_exists_string(nvl, "cipher"))
725 		return (EINVAL);
726 	ciphername = nvlist_get_string(nvl, "cipher");
727 
728 	if (strcmp(ciphername, "none") == 0)
729 		cipher = OVPN_CIPHER_ALG_NONE;
730 	else if (strcmp(ciphername, "AES-256-GCM") == 0 ||
731 	    strcmp(ciphername, "AES-192-GCM") == 0 ||
732 	    strcmp(ciphername, "AES-128-GCM") == 0)
733 		cipher = OVPN_CIPHER_ALG_AES_GCM;
734 	else if (strcmp(ciphername, "CHACHA20-POLY1305") == 0)
735 		cipher = OVPN_CIPHER_ALG_CHACHA20_POLY1305;
736 	else
737 		return (EINVAL);
738 
739 	if (cipher != OVPN_CIPHER_ALG_NONE) {
740 		if (! nvlist_exists_binary(nvl, "key"))
741 			return (EINVAL);
742 		key = nvlist_get_binary(nvl, "key", &keylen);
743 		if (keylen > sizeof(kdir->key))
744 			return (E2BIG);
745 
746 		if (! nvlist_exists_binary(nvl, "iv"))
747 			return (EINVAL);
748 		iv = nvlist_get_binary(nvl, "iv", &ivlen);
749 		if (ivlen != 8)
750 			return (E2BIG);
751 	}
752 
753 	kdir = malloc(sizeof(struct ovpn_kkey_dir), M_OVPN,
754 	    M_WAITOK | M_ZERO);
755 
756 	kdir->cipher = cipher;
757 	kdir->keylen = keylen;
758 	kdir->tx_seq = 1;
759 	memcpy(kdir->key, key, keylen);
760 	kdir->noncelen = ivlen;
761 	memcpy(kdir->nonce, iv, ivlen);
762 
763 	if (kdir->cipher != OVPN_CIPHER_ALG_NONE) {
764 		/* Crypto init */
765 		bzero(&csp, sizeof(csp));
766 		csp.csp_mode = CSP_MODE_AEAD;
767 
768 		if (kdir->cipher == OVPN_CIPHER_ALG_CHACHA20_POLY1305)
769 			csp.csp_cipher_alg = CRYPTO_CHACHA20_POLY1305;
770 		else
771 			csp.csp_cipher_alg = CRYPTO_AES_NIST_GCM_16;
772 
773 		csp.csp_flags |= CSP_F_SEPARATE_AAD;
774 
775 		csp.csp_cipher_klen = kdir->keylen;
776 		csp.csp_cipher_key = kdir->key;
777 		csp.csp_ivlen = 96 / 8;
778 
779 		error = crypto_newsession(&kdir->cryptoid, &csp,
780 		    CRYPTOCAP_F_HARDWARE | CRYPTOCAP_F_SOFTWARE);
781 		if (error) {
782 			free(kdir, M_OVPN);
783 			return (error);
784 		}
785 	}
786 
787 	mtx_init(&kdir->replay_mtx, "if_ovpn rx replay", NULL, MTX_DEF);
788 	*kdirp = kdir;
789 
790 	return (0);
791 }
792 
793 static void
ovpn_free_kkey_dir(struct ovpn_kkey_dir * kdir)794 ovpn_free_kkey_dir(struct ovpn_kkey_dir *kdir)
795 {
796 	if (kdir == NULL)
797 		return;
798 
799 	mtx_destroy(&kdir->replay_mtx);
800 
801 	crypto_freesession(kdir->cryptoid);
802 	free(kdir, M_OVPN);
803 }
804 
805 static int
ovpn_set_key(struct ifnet * ifp,const nvlist_t * nvl)806 ovpn_set_key(struct ifnet *ifp, const nvlist_t *nvl)
807 {
808 	struct ovpn_softc *sc = ifp->if_softc;
809 	struct ovpn_kkey_dir *enc, *dec;
810 	struct ovpn_kpeer *peer;
811 	int slot, keyid, peerid;
812 	int error;
813 
814 	if (nvl == NULL)
815 		return (EINVAL);
816 
817 	if (! nvlist_exists_number(nvl, "slot"))
818 		return (EINVAL);
819 	slot = nvlist_get_number(nvl, "slot");
820 
821 	if (! nvlist_exists_number(nvl, "keyid"))
822 		return (EINVAL);
823 	keyid = nvlist_get_number(nvl, "keyid");
824 
825 	if (! nvlist_exists_number(nvl, "peerid"))
826 		return (EINVAL);
827 	peerid = nvlist_get_number(nvl, "peerid");
828 
829 	if (slot != OVPN_KEY_SLOT_PRIMARY &&
830 	    slot != OVPN_KEY_SLOT_SECONDARY)
831 		return (EINVAL);
832 
833 	if (! nvlist_exists_nvlist(nvl, "encrypt") ||
834 	    ! nvlist_exists_nvlist(nvl, "decrypt"))
835 		return (EINVAL);
836 
837 	error = ovpn_create_kkey_dir(&enc, nvlist_get_nvlist(nvl, "encrypt"));
838 	if (error)
839 		return (error);
840 
841 	error = ovpn_create_kkey_dir(&dec, nvlist_get_nvlist(nvl, "decrypt"));
842 	if (error) {
843 		ovpn_free_kkey_dir(enc);
844 		return (error);
845 	}
846 
847 	OVPN_WLOCK(sc);
848 
849 	peer = ovpn_find_peer(sc, peerid);
850 	if (peer == NULL) {
851 		ovpn_free_kkey_dir(dec);
852 		ovpn_free_kkey_dir(enc);
853 		OVPN_WUNLOCK(sc);
854 		return (ENOENT);
855 	}
856 
857 	ovpn_free_kkey_dir(peer->keys[slot].encrypt);
858 	ovpn_free_kkey_dir(peer->keys[slot].decrypt);
859 
860 	peer->keys[slot].encrypt = enc;
861 	peer->keys[slot].decrypt = dec;
862 
863 	peer->keys[slot].keyid = keyid;
864 	peer->keys[slot].peerid = peerid;
865 
866 	OVPN_WUNLOCK(sc);
867 
868 	return (0);
869 }
870 
871 static int
ovpn_check_key(struct ovpn_softc * sc,struct ovpn_kpeer * peer,enum ovpn_key_slot slot)872 ovpn_check_key(struct ovpn_softc *sc, struct ovpn_kpeer *peer, enum ovpn_key_slot slot)
873 {
874 	OVPN_ASSERT(sc);
875 
876 	if (peer->keys[slot].encrypt == NULL)
877 		return (ENOLINK);
878 
879 	if (peer->keys[slot].decrypt == NULL)
880 		return (ENOLINK);
881 
882 	return (0);
883 }
884 
885 static int
ovpn_start(struct ifnet * ifp)886 ovpn_start(struct ifnet *ifp)
887 {
888 	struct ovpn_softc *sc = ifp->if_softc;
889 
890 	OVPN_WLOCK(sc);
891 
892 	ifp->if_flags |= IFF_UP;
893 	ifp->if_drv_flags |= IFF_DRV_RUNNING;
894 	if_link_state_change(ifp, LINK_STATE_UP);
895 
896 	OVPN_WUNLOCK(sc);
897 
898 	return (0);
899 }
900 
901 static int
ovpn_swap_keys(struct ifnet * ifp,nvlist_t * nvl)902 ovpn_swap_keys(struct ifnet *ifp, nvlist_t *nvl)
903 {
904 	struct ovpn_softc *sc = ifp->if_softc;
905 	struct ovpn_kpeer *peer;
906 	struct ovpn_kkey tmpkey;
907 	int error;
908 
909 	if (nvl == NULL)
910 		return (EINVAL);
911 
912 	if (! nvlist_exists_number(nvl, "peerid"))
913 		return (EINVAL);
914 
915 	OVPN_WLOCK(sc);
916 
917 	peer = ovpn_find_peer(sc, nvlist_get_number(nvl, "peerid"));
918 	if (peer == NULL) {
919 		OVPN_WUNLOCK(sc);
920 		return (ENOENT);
921 	}
922 
923 	/* Check that we have a second key to swap to. */
924 	error = ovpn_check_key(sc, peer, OVPN_KEY_SLOT_SECONDARY);
925 	if (error) {
926 		OVPN_WUNLOCK(sc);
927 		return (error);
928 	}
929 
930 	tmpkey = peer->keys[0];
931 	peer->keys[0] = peer->keys[1];
932 	peer->keys[1] = tmpkey;
933 
934 	OVPN_WUNLOCK(sc);
935 
936 	return (0);
937 }
938 
939 static int
ovpn_del_key(struct ifnet * ifp,const nvlist_t * nvl)940 ovpn_del_key(struct ifnet *ifp, const nvlist_t *nvl)
941 {
942 	enum ovpn_key_slot slot;
943 	struct ovpn_kpeer *peer;
944 	struct ovpn_softc *sc = ifp->if_softc;
945 
946 	if (nvl == NULL)
947 		return (EINVAL);
948 
949 	if (! nvlist_exists_number(nvl, "peerid"))
950 		return (EINVAL);
951 
952 	if (! nvlist_exists_number(nvl, "slot"))
953 		return (EINVAL);
954 	slot = nvlist_get_number(nvl, "slot");
955 
956 	if (slot != OVPN_KEY_SLOT_PRIMARY &&
957 	    slot != OVPN_KEY_SLOT_SECONDARY)
958 		return (EINVAL);
959 
960 	OVPN_WLOCK(sc);
961 
962 	peer = ovpn_find_peer(sc, nvlist_get_number(nvl, "peerid"));
963 	if (peer == NULL) {
964 		OVPN_WUNLOCK(sc);
965 		return (ENOENT);
966 	}
967 
968 	ovpn_free_kkey_dir(peer->keys[slot].encrypt);
969 	ovpn_free_kkey_dir(peer->keys[slot].decrypt);
970 
971 	peer->keys[slot].encrypt = NULL;
972 	peer->keys[slot].decrypt = NULL;
973 
974 	peer->keys[slot].keyid = 0;
975 	peer->keys[slot].peerid = 0;
976 
977 	OVPN_WUNLOCK(sc);
978 
979 	return (0);
980 }
981 
982 static void
ovpn_send_ping(void * arg)983 ovpn_send_ping(void *arg)
984 {
985 	static const uint8_t ping_str[] = {
986 		0x2a, 0x18, 0x7b, 0xf3, 0x64, 0x1e, 0xb4, 0xcb,
987 		0x07, 0xed, 0x2d, 0x0a, 0x98, 0x1f, 0xc7, 0x48
988 	};
989 
990 	struct epoch_tracker et;
991 	struct ovpn_kpeer *peer = arg;
992 	struct ovpn_softc *sc = peer->sc;
993 	struct mbuf *m;
994 
995 	OVPN_RASSERT(sc);
996 
997 	/* Ensure we repeat! */
998 	callout_reset(&peer->ping_send, peer->keepalive.interval * hz,
999 	    ovpn_send_ping, peer);
1000 
1001 	m = m_get2(sizeof(ping_str), M_NOWAIT, MT_DATA, M_PKTHDR);
1002 	if (m == NULL)
1003 		return;
1004 
1005 	m_copyback(m, 0, sizeof(ping_str), ping_str);
1006 	m->m_len = m->m_pkthdr.len = sizeof(ping_str);
1007 
1008 	CURVNET_SET(sc->ifp->if_vnet);
1009 	NET_EPOCH_ENTER(et);
1010 	(void)ovpn_transmit_to_peer(sc->ifp, m, peer, NULL);
1011 	NET_EPOCH_EXIT(et);
1012 	CURVNET_RESTORE();
1013 }
1014 
1015 static void
ovpn_timeout(void * arg)1016 ovpn_timeout(void *arg)
1017 {
1018 	struct ovpn_kpeer *peer = arg;
1019 	struct ovpn_softc *sc = peer->sc;
1020 	uint32_t last, _last_active;
1021 	int ret __diagused;
1022 	int cpu;
1023 
1024 	OVPN_WASSERT(sc);
1025 
1026 	last = 0;
1027 	CPU_FOREACH(cpu) {
1028 		_last_active = *zpcpu_get_cpu(peer->last_active, cpu);
1029 		if (_last_active > last)
1030 			last = _last_active;
1031 	}
1032 
1033 	if (last + peer->keepalive.timeout > time_uptime) {
1034 		callout_reset(&peer->ping_rcv,
1035 		    (peer->keepalive.timeout - (time_uptime - last)) * hz,
1036 		    ovpn_timeout, peer);
1037 		return;
1038 	}
1039 
1040 	CURVNET_SET(sc->ifp->if_vnet);
1041 	peer->del_reason = OVPN_DEL_REASON_TIMEOUT;
1042 	ret = _ovpn_del_peer(sc, peer);
1043 	MPASS(ret == 0);
1044 	CURVNET_RESTORE();
1045 }
1046 
1047 static int
ovpn_set_peer(struct ifnet * ifp,const nvlist_t * nvl)1048 ovpn_set_peer(struct ifnet *ifp, const nvlist_t *nvl)
1049 {
1050 	struct ovpn_softc *sc = ifp->if_softc;
1051 	struct ovpn_kpeer *peer;
1052 
1053 	if (nvl == NULL)
1054 		return (EINVAL);
1055 
1056 	if (! nvlist_exists_number(nvl, "interval") ||
1057 	    ! nvlist_exists_number(nvl, "timeout") ||
1058 	    ! nvlist_exists_number(nvl, "peerid"))
1059 		return (EINVAL);
1060 
1061 	OVPN_WLOCK(sc);
1062 
1063 	peer = ovpn_find_peer(sc, nvlist_get_number(nvl, "peerid"));
1064 	if (peer == NULL) {
1065 		OVPN_WUNLOCK(sc);
1066 		return (ENOENT);
1067 	}
1068 
1069 	peer->keepalive.interval = nvlist_get_number(nvl, "interval");
1070 	peer->keepalive.timeout = nvlist_get_number(nvl, "timeout");
1071 
1072 	if (peer->keepalive.interval > 0)
1073 		callout_reset(&peer->ping_send, peer->keepalive.interval * hz,
1074 		    ovpn_send_ping, peer);
1075 	if (peer->keepalive.timeout > 0)
1076 		callout_reset(&peer->ping_rcv, peer->keepalive.timeout * hz,
1077 		    ovpn_timeout, peer);
1078 
1079 	OVPN_WUNLOCK(sc);
1080 
1081 	return (0);
1082 }
1083 
1084 static int
ovpn_set_ifmode(struct ifnet * ifp,const nvlist_t * nvl)1085 ovpn_set_ifmode(struct ifnet *ifp, const nvlist_t *nvl)
1086 {
1087 	struct ovpn_softc *sc = ifp->if_softc;
1088 	int ifmode;
1089 
1090 	if (nvl == NULL)
1091 		return (EINVAL);
1092 
1093 	if (! nvlist_exists_number(nvl, "ifmode") )
1094 		return (EINVAL);
1095 
1096 	ifmode = nvlist_get_number(nvl, "ifmode");
1097 
1098 	OVPN_WLOCK(sc);
1099 
1100 	/* deny this if UP */
1101 	if (ifp->if_flags & IFF_UP) {
1102 		OVPN_WUNLOCK(sc);
1103 		return (EBUSY);
1104 	}
1105 
1106 	switch (ifmode & ~IFF_MULTICAST) {
1107 	case IFF_POINTOPOINT:
1108 	case IFF_BROADCAST:
1109 		ifp->if_flags &=
1110 		    ~(IFF_BROADCAST|IFF_POINTOPOINT|IFF_MULTICAST);
1111 		ifp->if_flags |= ifmode;
1112 		break;
1113 	default:
1114 		OVPN_WUNLOCK(sc);
1115 		return (EINVAL);
1116 	}
1117 
1118 	OVPN_WUNLOCK(sc);
1119 
1120 	return (0);
1121 }
1122 
1123 static int
ovpn_ioctl_set(struct ifnet * ifp,struct ifdrv * ifd)1124 ovpn_ioctl_set(struct ifnet *ifp, struct ifdrv *ifd)
1125 {
1126 	struct ovpn_softc *sc = ifp->if_softc;
1127 	uint8_t *buf = NULL;
1128 	nvlist_t *nvl = NULL;
1129 	int ret;
1130 
1131 	if (ifd->ifd_len != 0) {
1132 		if (ifd->ifd_len > OVPN_MAX_REQUEST_SIZE)
1133 			return (E2BIG);
1134 
1135 		buf = malloc(ifd->ifd_len, M_OVPN, M_WAITOK);
1136 
1137 		ret = copyin(ifd->ifd_data, buf, ifd->ifd_len);
1138 		if (ret != 0) {
1139 			free(buf, M_OVPN);
1140 			return (ret);
1141 		}
1142 
1143 		nvl = nvlist_unpack(buf, ifd->ifd_len, 0);
1144 		free(buf, M_OVPN);
1145 		if (nvl == NULL) {
1146 			return (EINVAL);
1147 		}
1148 	}
1149 
1150 	switch (ifd->ifd_cmd) {
1151 	case OVPN_NEW_PEER:
1152 		ret = ovpn_new_peer(ifp, nvl);
1153 		break;
1154 	case OVPN_DEL_PEER:
1155 		OVPN_WLOCK(sc);
1156 		ret = ovpn_del_peer(ifp, nvl);
1157 		OVPN_WUNLOCK(sc);
1158 		break;
1159 	case OVPN_NEW_KEY:
1160 		ret = ovpn_set_key(ifp, nvl);
1161 		break;
1162 	case OVPN_START_VPN:
1163 		ret = ovpn_start(ifp);
1164 		break;
1165 	case OVPN_SWAP_KEYS:
1166 		ret = ovpn_swap_keys(ifp, nvl);
1167 		break;
1168 	case OVPN_DEL_KEY:
1169 		ret = ovpn_del_key(ifp, nvl);
1170 		break;
1171 	case OVPN_SET_PEER:
1172 		ret = ovpn_set_peer(ifp, nvl);
1173 		break;
1174 	case OVPN_SET_IFMODE:
1175 		ret = ovpn_set_ifmode(ifp, nvl);
1176 		break;
1177 	default:
1178 		ret = ENOTSUP;
1179 	}
1180 
1181 	nvlist_destroy(nvl);
1182 	return (ret);
1183 }
1184 
1185 static int
ovpn_add_counters(nvlist_t * parent,const char * name,counter_u64_t in,counter_u64_t out)1186 ovpn_add_counters(nvlist_t *parent, const char *name, counter_u64_t in,
1187     counter_u64_t out)
1188 {
1189 	nvlist_t *nvl;
1190 
1191 	nvl = nvlist_create(0);
1192 	if (nvl == NULL)
1193 		return (ENOMEM);
1194 
1195 	nvlist_add_number(nvl, "in", counter_u64_fetch(in));
1196 	nvlist_add_number(nvl, "out", counter_u64_fetch(out));
1197 
1198 	nvlist_add_nvlist(parent, name, nvl);
1199 
1200 	nvlist_destroy(nvl);
1201 
1202 	return (0);
1203 }
1204 
1205 static int
ovpn_get_stats(struct ovpn_softc * sc,nvlist_t ** onvl)1206 ovpn_get_stats(struct ovpn_softc *sc, nvlist_t **onvl)
1207 {
1208 	nvlist_t *nvl;
1209 	int ret;
1210 
1211 	nvl = nvlist_create(0);
1212 	if (nvl == NULL)
1213 		return (ENOMEM);
1214 
1215 #define OVPN_COUNTER_OUT(name, in, out) \
1216 	do { \
1217 		ret = ovpn_add_counters(nvl, name, OVPN_COUNTER(sc, in), \
1218 		    OVPN_COUNTER(sc, out)); \
1219 		if (ret != 0) \
1220 			goto error; \
1221 	} while(0)
1222 
1223 	OVPN_COUNTER_OUT("lost_ctrl", lost_ctrl_pkts_in, lost_ctrl_pkts_out);
1224 	OVPN_COUNTER_OUT("lost_data", lost_data_pkts_in, lost_data_pkts_out);
1225 	OVPN_COUNTER_OUT("nomem_data", nomem_data_pkts_in,
1226 	    nomem_data_pkts_out);
1227 	OVPN_COUNTER_OUT("data", received_data_pkts, sent_data_pkts);
1228 	OVPN_COUNTER_OUT("ctrl", received_ctrl_pkts, sent_ctrl_pkts);
1229 	OVPN_COUNTER_OUT("tunnel", tunnel_bytes_received,
1230 	    tunnel_bytes_received);
1231 	OVPN_COUNTER_OUT("transport", transport_bytes_received,
1232 	    transport_bytes_received);
1233 #undef OVPN_COUNTER_OUT
1234 
1235 	*onvl = nvl;
1236 
1237 	return (0);
1238 
1239 error:
1240 	nvlist_destroy(nvl);
1241 	return (ret);
1242 }
1243 
1244 static int
ovpn_get_peer_stats(struct ovpn_softc * sc,nvlist_t ** nvl)1245 ovpn_get_peer_stats(struct ovpn_softc *sc, nvlist_t **nvl)
1246 {
1247 	struct ovpn_kpeer *peer;
1248 	nvlist_t *nvpeer = NULL;
1249 	int ret;
1250 
1251 	OVPN_RLOCK_TRACKER;
1252 
1253 	*nvl = nvlist_create(0);
1254 	if (*nvl == NULL)
1255 		return (ENOMEM);
1256 
1257 #define OVPN_PEER_COUNTER_OUT(name, in, out) \
1258 	do { \
1259 		ret = ovpn_add_counters(nvpeer, name, \
1260 		    OVPN_PEER_COUNTER(peer, in), OVPN_PEER_COUNTER(peer, out)); \
1261 		if (ret != 0) \
1262 			goto error; \
1263 	} while(0)
1264 
1265 	OVPN_RLOCK(sc);
1266 	RB_FOREACH(peer, ovpn_kpeers, &sc->peers) {
1267 		nvpeer = nvlist_create(0);
1268 		if (nvpeer == NULL) {
1269 			OVPN_RUNLOCK(sc);
1270 			nvlist_destroy(*nvl);
1271 			*nvl = NULL;
1272 			return (ENOMEM);
1273 		}
1274 
1275 		nvlist_add_number(nvpeer, "peerid", peer->peerid);
1276 
1277 		OVPN_PEER_COUNTER_OUT("packets", pkt_in, pkt_out);
1278 		OVPN_PEER_COUNTER_OUT("bytes", bytes_in, bytes_out);
1279 
1280 		nvlist_append_nvlist_array(*nvl, "peers", nvpeer);
1281 		nvlist_destroy(nvpeer);
1282 	}
1283 #undef OVPN_PEER_COUNTER_OUT
1284 	OVPN_RUNLOCK(sc);
1285 
1286 	return (0);
1287 
1288 error:
1289 	nvlist_destroy(nvpeer);
1290 	nvlist_destroy(*nvl);
1291 	*nvl = NULL;
1292 	return (ret);
1293 }
1294 
1295 static int
ovpn_poll_pkt(struct ovpn_softc * sc,nvlist_t ** onvl)1296 ovpn_poll_pkt(struct ovpn_softc *sc, nvlist_t **onvl)
1297 {
1298 	nvlist_t *nvl;
1299 
1300 	nvl = nvlist_create(0);
1301 	if (nvl == NULL)
1302 		return (ENOMEM);
1303 
1304 	nvlist_add_number(nvl, "pending", buf_ring_count(sc->notifring));
1305 
1306 	*onvl = nvl;
1307 
1308 	return (0);
1309 }
1310 
1311 static void
ovpn_notif_add_counters(nvlist_t * parent,struct ovpn_notification * n)1312 ovpn_notif_add_counters(nvlist_t *parent, struct ovpn_notification *n)
1313 {
1314 	nvlist_t *nvl;
1315 
1316 	nvl = nvlist_create(0);
1317 	if (nvl == NULL)
1318 		return;
1319 
1320 	nvlist_add_number(nvl, "in", n->counters.pkt_in);
1321 	nvlist_add_number(nvl, "out", n->counters.pkt_out);
1322 
1323 	nvlist_add_nvlist(parent, "packets", nvl);
1324 	nvlist_destroy(nvl);
1325 
1326 	nvl = nvlist_create(0);
1327 	if (nvl == NULL)
1328 		return;
1329 
1330 	nvlist_add_number(nvl, "in", n->counters.bytes_in);
1331 	nvlist_add_number(nvl, "out", n->counters.bytes_out);
1332 
1333 	nvlist_add_nvlist(parent, "bytes", nvl);
1334 	nvlist_destroy(nvl);
1335 }
1336 
1337 static int
opvn_get_pkt(struct ovpn_softc * sc,nvlist_t ** onvl)1338 opvn_get_pkt(struct ovpn_softc *sc, nvlist_t **onvl)
1339 {
1340 	struct ovpn_notification *n;
1341 	nvlist_t *nvl;
1342 
1343 	/* Check if we have notifications pending. */
1344 	n = buf_ring_dequeue_mc(sc->notifring);
1345 	if (n == NULL)
1346 		return (ENOENT);
1347 
1348 	nvl = nvlist_create(0);
1349 	if (nvl == NULL) {
1350 		free(n, M_OVPN);
1351 		return (ENOMEM);
1352 	}
1353 	nvlist_add_number(nvl, "peerid", n->peerid);
1354 	nvlist_add_number(nvl, "notification", n->type);
1355 	if (n->type == OVPN_NOTIF_DEL_PEER) {
1356 		nvlist_add_number(nvl, "del_reason", n->del_reason);
1357 
1358 		/* No error handling, because we want to send the notification
1359 		 * even if we can't attach the counters. */
1360 		ovpn_notif_add_counters(nvl, n);
1361 	}
1362 	free(n, M_OVPN);
1363 
1364 	*onvl = nvl;
1365 
1366 	return (0);
1367 }
1368 
1369 static int
ovpn_ioctl_get(struct ifnet * ifp,struct ifdrv * ifd)1370 ovpn_ioctl_get(struct ifnet *ifp, struct ifdrv *ifd)
1371 {
1372 	struct ovpn_softc *sc = ifp->if_softc;
1373 	nvlist_t *nvl = NULL;
1374 	int error;
1375 
1376 	switch (ifd->ifd_cmd) {
1377 	case OVPN_GET_STATS:
1378 		error = ovpn_get_stats(sc, &nvl);
1379 		break;
1380 	case OVPN_GET_PEER_STATS:
1381 		error = ovpn_get_peer_stats(sc, &nvl);
1382 		break;
1383 	case OVPN_POLL_PKT:
1384 		error = ovpn_poll_pkt(sc, &nvl);
1385 		break;
1386 	case OVPN_GET_PKT:
1387 		error = opvn_get_pkt(sc, &nvl);
1388 		break;
1389 	default:
1390 		error = ENOTSUP;
1391 		break;
1392 	}
1393 
1394 	if (error == 0) {
1395 		void *packed = NULL;
1396 		size_t len;
1397 
1398 		MPASS(nvl != NULL);
1399 
1400 		packed = nvlist_pack(nvl, &len);
1401 		if (! packed) {
1402 			nvlist_destroy(nvl);
1403 			return (ENOMEM);
1404 		}
1405 
1406 		if (len > ifd->ifd_len) {
1407 			free(packed, M_NVLIST);
1408 			nvlist_destroy(nvl);
1409 			return (ENOSPC);
1410 		}
1411 
1412 		error = copyout(packed, ifd->ifd_data, len);
1413 		ifd->ifd_len = len;
1414 
1415 		free(packed, M_NVLIST);
1416 		nvlist_destroy(nvl);
1417 	}
1418 
1419 	return (error);
1420 }
1421 
1422 static int
ovpn_ioctl(struct ifnet * ifp,u_long cmd,caddr_t data)1423 ovpn_ioctl(struct ifnet *ifp, u_long cmd, caddr_t data)
1424 {
1425 	struct ifdrv *ifd;
1426 	int error;
1427 
1428 	CURVNET_ASSERT_SET();
1429 
1430 	switch (cmd) {
1431 	case SIOCSDRVSPEC:
1432 	case SIOCGDRVSPEC:
1433 		error = priv_check(curthread, PRIV_NET_OVPN);
1434 		if (error)
1435 			return (error);
1436 		break;
1437 	}
1438 
1439 	switch (cmd) {
1440 	case SIOCSDRVSPEC:
1441 		ifd = (struct ifdrv *)data;
1442 		error = ovpn_ioctl_set(ifp, ifd);
1443 		break;
1444 	case SIOCGDRVSPEC:
1445 		ifd = (struct ifdrv *)data;
1446 		error = ovpn_ioctl_get(ifp, ifd);
1447 		break;
1448 	case SIOCSIFMTU: {
1449 		struct ifreq *ifr = (struct ifreq *)data;
1450 		if (ifr->ifr_mtu < OVPN_MTU_MIN || ifr->ifr_mtu > OVPN_MTU_MAX)
1451 			return (EINVAL);
1452 
1453 		ifp->if_mtu = ifr->ifr_mtu;
1454 		return (0);
1455 	}
1456 	case SIOCSIFADDR:
1457 	case SIOCADDMULTI:
1458 	case SIOCDELMULTI:
1459 	case SIOCGIFMTU:
1460 	case SIOCSIFFLAGS:
1461 		return (0);
1462 	default:
1463 		error = EINVAL;
1464 	}
1465 
1466 	return (error);
1467 }
1468 
1469 static int
ovpn_encrypt_tx_cb(struct cryptop * crp)1470 ovpn_encrypt_tx_cb(struct cryptop *crp)
1471 {
1472 	struct epoch_tracker et;
1473 	struct ovpn_kpeer *peer = crp->crp_opaque;
1474 	struct ovpn_softc *sc = peer->sc;
1475 	struct mbuf *m = crp->crp_buf.cb_mbuf;
1476 	int tunnel_len;
1477 	int ret;
1478 
1479 	CURVNET_SET(sc->ifp->if_vnet);
1480 	NET_EPOCH_ENTER(et);
1481 
1482 	if (crp->crp_etype != 0) {
1483 		crypto_freereq(crp);
1484 		ovpn_peer_release_ref(peer, false);
1485 		NET_EPOCH_EXIT(et);
1486 		CURVNET_RESTORE();
1487 		OVPN_COUNTER_ADD(sc, lost_data_pkts_out, 1);
1488 		m_freem(m);
1489 		return (0);
1490 	}
1491 
1492 	MPASS(crp->crp_buf.cb_type == CRYPTO_BUF_MBUF);
1493 
1494 	tunnel_len = m->m_pkthdr.len - sizeof(struct ovpn_wire_header);
1495 	ret = ovpn_encap(sc, peer->peerid, m);
1496 	if (ret == 0) {
1497 		OVPN_COUNTER_ADD(sc, sent_data_pkts, 1);
1498 		OVPN_COUNTER_ADD(sc, tunnel_bytes_sent, tunnel_len);
1499 	}
1500 
1501 	crypto_freereq(crp);
1502 	ovpn_peer_release_ref(peer, false);
1503 
1504 	NET_EPOCH_EXIT(et);
1505 	CURVNET_RESTORE();
1506 
1507 	return (0);
1508 }
1509 
1510 static void
ovpn_finish_rx(struct ovpn_softc * sc,struct mbuf * m,struct ovpn_kpeer * peer,struct ovpn_kkey * key,uint32_t seq,struct rm_priotracker * _ovpn_lock_trackerp)1511 ovpn_finish_rx(struct ovpn_softc *sc, struct mbuf *m,
1512     struct ovpn_kpeer *peer, struct ovpn_kkey *key, uint32_t seq,
1513     struct rm_priotracker *_ovpn_lock_trackerp)
1514 {
1515 	uint32_t af;
1516 
1517 	OVPN_RASSERT(sc);
1518 	NET_EPOCH_ASSERT();
1519 
1520 	/* Replay protection. */
1521 	if (V_replay_protection && ! ovpn_check_replay(key->decrypt, seq)) {
1522 		OVPN_RUNLOCK(sc);
1523 		OVPN_COUNTER_ADD(sc, lost_data_pkts_in, 1);
1524 		m_freem(m);
1525 		return;
1526 	}
1527 
1528 	critical_enter();
1529 	*zpcpu_get(peer->last_active) = time_uptime;
1530 	critical_exit();
1531 
1532 	OVPN_RUNLOCK(sc);
1533 
1534 	OVPN_COUNTER_ADD(sc, received_data_pkts, 1);
1535 	OVPN_COUNTER_ADD(sc, tunnel_bytes_received, m->m_pkthdr.len);
1536 	OVPN_PEER_COUNTER_ADD(peer, pkt_in, 1);
1537 	OVPN_PEER_COUNTER_ADD(peer, bytes_in, m->m_pkthdr.len);
1538 
1539 	/* Receive the packet on our interface. */
1540 	m->m_pkthdr.rcvif = sc->ifp;
1541 
1542 	/* Clear checksum flags in case the real hardware set them. */
1543 	m->m_pkthdr.csum_flags = 0;
1544 
1545 	/* Clear mbuf tags & flags */
1546 	m_tag_delete_nonpersistent(m);
1547 	m_clrprotoflags(m);
1548 
1549 	/* Ensure we can read the first byte. */
1550 	m = m_pullup(m, 1);
1551 	if (m == NULL) {
1552 		OVPN_COUNTER_ADD(sc, nomem_data_pkts_in, 1);
1553 		return;
1554 	}
1555 
1556 	/*
1557 	 * Check for address family, and disregard any control packets (e.g.
1558 	 * keepalive).
1559 	 */
1560 	af = ovpn_get_af(m);
1561 	if (af != 0) {
1562 		BPF_MTAP2(sc->ifp, &af, sizeof(af), m);
1563 		if (V_async_netisr_queue)
1564 			netisr_queue(af == AF_INET ? NETISR_IP : NETISR_IPV6, m);
1565 		else
1566 			netisr_dispatch(af == AF_INET ? NETISR_IP : NETISR_IPV6, m);
1567 	} else {
1568 		OVPN_COUNTER_ADD(sc, lost_data_pkts_in, 1);
1569 		m_freem(m);
1570 	}
1571 }
1572 
1573 static struct ovpn_kkey *
ovpn_find_key(struct ovpn_softc * sc,struct ovpn_kpeer * peer,const struct ovpn_wire_header * ohdr)1574 ovpn_find_key(struct ovpn_softc *sc, struct ovpn_kpeer *peer,
1575     const struct ovpn_wire_header *ohdr)
1576 {
1577 	struct ovpn_kkey *key = NULL;
1578 	uint8_t keyid;
1579 
1580 	OVPN_RASSERT(sc);
1581 
1582 	keyid = (ntohl(ohdr->opcode) >> 24) & 0x07;
1583 
1584 	if (peer->keys[0].keyid == keyid)
1585 		key = &peer->keys[0];
1586 	else if (peer->keys[1].keyid == keyid)
1587 		key = &peer->keys[1];
1588 
1589 	return (key);
1590 }
1591 
1592 static int
ovpn_decrypt_rx_cb(struct cryptop * crp)1593 ovpn_decrypt_rx_cb(struct cryptop *crp)
1594 {
1595 	struct epoch_tracker et;
1596 	struct ovpn_softc *sc = crp->crp_opaque;
1597 	struct mbuf *m = crp->crp_buf.cb_mbuf;
1598 	struct ovpn_kkey *key;
1599 	struct ovpn_kpeer *peer;
1600 	struct ovpn_wire_header *ohdr;
1601 	uint32_t peerid;
1602 
1603 	OVPN_RLOCK_TRACKER;
1604 
1605 	OVPN_RLOCK(sc);
1606 
1607 	MPASS(crp->crp_buf.cb_type == CRYPTO_BUF_MBUF);
1608 
1609 	if (crp->crp_etype != 0) {
1610 		crypto_freereq(crp);
1611 		atomic_add_int(&sc->refcount, -1);
1612 		OVPN_COUNTER_ADD(sc, lost_data_pkts_in, 1);
1613 		OVPN_RUNLOCK(sc);
1614 		m_freem(m);
1615 		return (0);
1616 	}
1617 
1618 	CURVNET_SET(sc->ifp->if_vnet);
1619 
1620 	ohdr = mtodo(m, sizeof(struct udphdr));
1621 
1622 	peerid = ntohl(ohdr->opcode) & 0x00ffffff;
1623 	peer = ovpn_find_peer(sc, peerid);
1624 	if (peer == NULL) {
1625 		/* No such peer. Drop packet. */
1626 		crypto_freereq(crp);
1627 		atomic_add_int(&sc->refcount, -1);
1628 		OVPN_RUNLOCK(sc);
1629 		OVPN_COUNTER_ADD(sc, lost_data_pkts_in, 1);
1630 		m_freem(m);
1631 		CURVNET_RESTORE();
1632 		return (0);
1633 	}
1634 
1635 	key = ovpn_find_key(sc, peer, ohdr);
1636 	if (key == NULL) {
1637 		crypto_freereq(crp);
1638 		atomic_add_int(&sc->refcount, -1);
1639 		/*
1640 		 * Has this key been removed between us starting the decrypt
1641 		 * and finishing it?
1642 		 */
1643 		OVPN_RUNLOCK(sc);
1644 		OVPN_COUNTER_ADD(sc, lost_data_pkts_in, 1);
1645 		m_freem(m);
1646 		CURVNET_RESTORE();
1647 		return (0);
1648 	}
1649 
1650 	/* Now remove the outer headers */
1651 	m_adj_decap(m, sizeof(struct udphdr) +
1652 	    sizeof(struct ovpn_wire_header));
1653 
1654 	NET_EPOCH_ENTER(et);
1655 	ovpn_finish_rx(sc, m, peer, key, ntohl(ohdr->seq), _ovpn_lock_trackerp);
1656 	NET_EPOCH_EXIT(et);
1657 	OVPN_UNLOCK_ASSERT(sc);
1658 
1659 	CURVNET_RESTORE();
1660 
1661 	crypto_freereq(crp);
1662 	atomic_add_int(&sc->refcount, -1);
1663 
1664 	return (0);
1665 }
1666 
1667 static int
ovpn_get_af(struct mbuf * m)1668 ovpn_get_af(struct mbuf *m)
1669 {
1670 	struct ip *ip;
1671 	struct ip6_hdr *ip6;
1672 
1673 	/*
1674 	 * We should pullup, but we're only interested in the first byte, so
1675 	 * that'll always be contiguous.
1676 	 */
1677 	ip = mtod(m, struct ip *);
1678 	if (ip->ip_v == IPVERSION)
1679 		return (AF_INET);
1680 
1681 	ip6 = mtod(m, struct ip6_hdr *);
1682 	if ((ip6->ip6_vfc & IPV6_VERSION_MASK) == IPV6_VERSION)
1683 		return (AF_INET6);
1684 
1685 	return (0);
1686 }
1687 
1688 #ifdef INET
1689 static struct ovpn_kpeer *
ovpn_find_peer_by_ip(struct ovpn_softc * sc,const struct in_addr addr)1690 ovpn_find_peer_by_ip(struct ovpn_softc *sc, const struct in_addr addr)
1691 {
1692 	struct ovpn_kpeer *peer = NULL;
1693 
1694 	OVPN_ASSERT(sc);
1695 
1696 	/* TODO: Add a second RB so we can look up by IP. */
1697 	RB_FOREACH(peer, ovpn_kpeers, &sc->peers) {
1698 		if (addr.s_addr == peer->vpn4.s_addr)
1699 			return (peer);
1700 	}
1701 
1702 	return (peer);
1703 }
1704 #endif
1705 
1706 #ifdef INET6
1707 static struct ovpn_kpeer *
ovpn_find_peer_by_ip6(struct ovpn_softc * sc,const struct in6_addr * addr)1708 ovpn_find_peer_by_ip6(struct ovpn_softc *sc, const struct in6_addr *addr)
1709 {
1710 	struct ovpn_kpeer *peer = NULL;
1711 
1712 	OVPN_ASSERT(sc);
1713 
1714 	/* TODO: Add a third RB so we can look up by IPv6 address. */
1715 	RB_FOREACH(peer, ovpn_kpeers, &sc->peers) {
1716 		if (memcmp(addr, &peer->vpn6, sizeof(*addr)) == 0)
1717 			return (peer);
1718 	}
1719 
1720 	return (peer);
1721 }
1722 #endif
1723 
1724 static struct ovpn_kpeer *
ovpn_route_peer(struct ovpn_softc * sc,struct mbuf ** m0,const struct sockaddr * dst)1725 ovpn_route_peer(struct ovpn_softc *sc, struct mbuf **m0,
1726     const struct sockaddr *dst)
1727 {
1728 	struct ovpn_kpeer *peer = NULL;
1729 	int af;
1730 
1731 	NET_EPOCH_ASSERT();
1732 	OVPN_ASSERT(sc);
1733 
1734 	/* Shortcut if we're a client (or are a server and have only one client). */
1735 	if (sc->peercount == 1)
1736 		return (ovpn_find_only_peer(sc));
1737 
1738 	if (dst != NULL)
1739 		af = dst->sa_family;
1740 	else
1741 		af = ovpn_get_af(*m0);
1742 
1743 	switch (af) {
1744 #ifdef INET
1745 	case AF_INET: {
1746 		const struct sockaddr_in *sa = (const struct sockaddr_in *)dst;
1747 		struct nhop_object *nh;
1748 		const struct in_addr *ip_dst;
1749 
1750 		if (sa != NULL) {
1751 			ip_dst = &sa->sin_addr;
1752 		} else {
1753 			struct ip *ip;
1754 
1755 			*m0 = m_pullup(*m0, sizeof(struct ip));
1756 			if (*m0 == NULL)
1757 				return (NULL);
1758 			ip = mtod(*m0, struct ip *);
1759 			ip_dst = &ip->ip_dst;
1760 		}
1761 
1762 		peer = ovpn_find_peer_by_ip(sc, *ip_dst);
1763 		SDT_PROBE2(if_ovpn, tx, route, ip4, ip_dst, peer);
1764 		if (peer == NULL) {
1765 			nh = fib4_lookup(M_GETFIB(*m0), *ip_dst, 0,
1766 			    NHR_NONE, 0);
1767 			if (nh && (nh->nh_flags & NHF_GATEWAY)) {
1768 				peer = ovpn_find_peer_by_ip(sc,
1769 				    nh->gw4_sa.sin_addr);
1770 				SDT_PROBE2(if_ovpn, tx, route, ip4,
1771 				    &nh->gw4_sa.sin_addr, peer);
1772 			}
1773 		}
1774 		break;
1775 	}
1776 #endif
1777 #ifdef INET6
1778 	case AF_INET6: {
1779 		const struct sockaddr_in6 *sa6 =
1780 		    (const struct sockaddr_in6 *)dst;
1781 		struct nhop_object *nh;
1782 		const struct in6_addr *ip6_dst;
1783 
1784 		if (sa6 != NULL) {
1785 			ip6_dst = &sa6->sin6_addr;
1786 		} else {
1787 			struct ip6_hdr *ip6;
1788 
1789 			*m0 = m_pullup(*m0, sizeof(struct ip6_hdr));
1790 			if (*m0 == NULL)
1791 				return (NULL);
1792 			ip6 = mtod(*m0, struct ip6_hdr *);
1793 			ip6_dst = &ip6->ip6_dst;
1794 		}
1795 
1796 		peer = ovpn_find_peer_by_ip6(sc, ip6_dst);
1797 		SDT_PROBE2(if_ovpn, tx, route, ip6, ip6_dst, peer);
1798 		if (peer == NULL) {
1799 			nh = fib6_lookup(M_GETFIB(*m0), ip6_dst, 0,
1800 			    NHR_NONE, 0);
1801 			if (nh && (nh->nh_flags & NHF_GATEWAY)) {
1802 				peer = ovpn_find_peer_by_ip6(sc,
1803 				    &nh->gw6_sa.sin6_addr);
1804 				SDT_PROBE2(if_ovpn, tx, route, ip6,
1805 				    &nh->gw6_sa.sin6_addr, peer);
1806 			}
1807 		}
1808 		break;
1809 	}
1810 #endif
1811 	}
1812 
1813 	return (peer);
1814 }
1815 
1816 static int
ovpn_transmit(struct ifnet * ifp,struct mbuf * m)1817 ovpn_transmit(struct ifnet *ifp, struct mbuf *m)
1818 {
1819 	return (ifp->if_output(ifp, m, NULL, NULL));
1820 }
1821 
1822 static int
ovpn_transmit_to_peer(struct ifnet * ifp,struct mbuf * m,struct ovpn_kpeer * peer,struct rm_priotracker * _ovpn_lock_trackerp)1823 ovpn_transmit_to_peer(struct ifnet *ifp, struct mbuf *m,
1824     struct ovpn_kpeer *peer, struct rm_priotracker *_ovpn_lock_trackerp)
1825 {
1826 	struct ovpn_wire_header *ohdr;
1827 	struct ovpn_kkey *key;
1828 	struct ovpn_softc *sc;
1829 	struct cryptop *crp;
1830 	uint32_t af, seq;
1831 	uint64_t seq64;
1832 	size_t len, ovpn_hdr_len;
1833 	int tunnel_len;
1834 	int ret;
1835 
1836 	sc = ifp->if_softc;
1837 
1838 	OVPN_RASSERT(sc);
1839 
1840 	tunnel_len = m->m_pkthdr.len;
1841 
1842 	key = &peer->keys[OVPN_KEY_SLOT_PRIMARY];
1843 	if (key->encrypt == NULL) {
1844 		if (_ovpn_lock_trackerp != NULL)
1845 			OVPN_RUNLOCK(sc);
1846 		m_freem(m);
1847 		return (ENOLINK);
1848 	}
1849 
1850 	af = ovpn_get_af(m);
1851 	/* Don't capture control packets. */
1852 	if (af != 0)
1853 		BPF_MTAP2(ifp, &af, sizeof(af), m);
1854 
1855 	if (__predict_false(if_tunnel_check_nesting(ifp, m, MTAG_OVPN_LOOP, 3))) {
1856 		if (_ovpn_lock_trackerp != NULL)
1857 			OVPN_RUNLOCK(sc);
1858 		OVPN_COUNTER_ADD(sc, lost_data_pkts_out, 1);
1859 		m_freem(m);
1860 		return (ELOOP);
1861 	}
1862 
1863 	len = m->m_pkthdr.len;
1864 	MPASS(len <= ifp->if_mtu);
1865 
1866 	ovpn_hdr_len = sizeof(struct ovpn_wire_header);
1867 	if (key->encrypt->cipher == OVPN_CIPHER_ALG_NONE)
1868 		ovpn_hdr_len -= 16; /* No auth tag. */
1869 
1870 	M_PREPEND(m, ovpn_hdr_len, M_NOWAIT);
1871 	if (m == NULL) {
1872 		if (_ovpn_lock_trackerp != NULL)
1873 			OVPN_RUNLOCK(sc);
1874 		OVPN_COUNTER_ADD(sc, nomem_data_pkts_out, 1);
1875 		return (ENOBUFS);
1876 	}
1877 	ohdr = mtod(m, struct ovpn_wire_header *);
1878 	ohdr->opcode = (OVPN_OP_DATA_V2 << OVPN_OP_SHIFT) | key->keyid;
1879 	ohdr->opcode <<= 24;
1880 	ohdr->opcode |= key->peerid;
1881 	ohdr->opcode = htonl(ohdr->opcode);
1882 
1883 	seq64 = atomic_fetchadd_64(&peer->keys[OVPN_KEY_SLOT_PRIMARY].encrypt->tx_seq, 1);
1884 	if (seq64 == OVPN_SEQ_ROTATE) {
1885 		ovpn_notify_key_rotation(sc, peer);
1886 	} else if (seq64 > UINT32_MAX) {
1887 		/* We've wrapped, give up on this packet. */
1888 		if (_ovpn_lock_trackerp != NULL)
1889 			OVPN_RUNLOCK(sc);
1890 		OVPN_COUNTER_ADD(sc, nomem_data_pkts_out, 1);
1891 
1892 		/* Let's avoid (very unlikely, but still) wraparounds of the
1893 		 * 64-bit counter taking us back to 0. */
1894 		atomic_store_64(&peer->keys[OVPN_KEY_SLOT_PRIMARY].encrypt->tx_seq,
1895 		    UINT32_MAX);
1896 
1897 		return (ENOBUFS);
1898 	}
1899 
1900 	seq = htonl(seq64 & UINT32_MAX);
1901 	ohdr->seq = seq;
1902 
1903 	OVPN_PEER_COUNTER_ADD(peer, pkt_out, 1);
1904 	OVPN_PEER_COUNTER_ADD(peer, bytes_out, len);
1905 
1906 	if (key->encrypt->cipher == OVPN_CIPHER_ALG_NONE) {
1907 		ret = ovpn_encap(sc, peer->peerid, m);
1908 		if (_ovpn_lock_trackerp != NULL)
1909 			OVPN_RUNLOCK(sc);
1910 		if (ret == 0) {
1911 			OVPN_COUNTER_ADD(sc, sent_data_pkts, 1);
1912 			OVPN_COUNTER_ADD(sc, tunnel_bytes_sent, tunnel_len);
1913 		}
1914 		return (ret);
1915 	}
1916 
1917 	crp = crypto_getreq(key->encrypt->cryptoid, M_NOWAIT);
1918 	if (crp == NULL) {
1919 		if (_ovpn_lock_trackerp != NULL)
1920 			OVPN_RUNLOCK(sc);
1921 		OVPN_COUNTER_ADD(sc, nomem_data_pkts_out, 1);
1922 		m_freem(m);
1923 		return (ENOBUFS);
1924 	}
1925 
1926 	/* Encryption covers only the payload, not the header. */
1927 	crp->crp_payload_start = sizeof(*ohdr);
1928 	crp->crp_payload_length = len;
1929 	crp->crp_op = CRYPTO_OP_ENCRYPT;
1930 
1931 	/*
1932 	 * AAD data covers the ovpn_wire_header minus the auth
1933 	 * tag.
1934 	 */
1935 	crp->crp_aad_length = sizeof(*ohdr) - sizeof(ohdr->auth_tag);
1936 	crp->crp_aad = ohdr;
1937 	crp->crp_aad_start = 0;
1938 	crp->crp_op |= CRYPTO_OP_COMPUTE_DIGEST;
1939 	crp->crp_digest_start = offsetof(struct ovpn_wire_header, auth_tag);
1940 
1941 	crp->crp_flags |= CRYPTO_F_IV_SEPARATE;
1942 	memcpy(crp->crp_iv, &seq, sizeof(seq));
1943 	memcpy(crp->crp_iv + sizeof(seq), key->encrypt->nonce,
1944 	    key->encrypt->noncelen);
1945 
1946 	crypto_use_mbuf(crp, m);
1947 	crp->crp_flags |= CRYPTO_F_CBIFSYNC;
1948 	crp->crp_callback = ovpn_encrypt_tx_cb;
1949 	crp->crp_opaque = peer;
1950 
1951 	atomic_add_int(&peer->refcount, 1);
1952 	if (_ovpn_lock_trackerp != NULL)
1953 		OVPN_RUNLOCK(sc);
1954 	if (V_async_crypto)
1955 		ret = crypto_dispatch_async(crp, CRYPTO_ASYNC_ORDERED);
1956 	else
1957 		ret = crypto_dispatch(crp);
1958 	if (ret) {
1959 		OVPN_COUNTER_ADD(sc, lost_data_pkts_out, 1);
1960 	}
1961 
1962 	return (ret);
1963 }
1964 
1965 /*
1966  * Note: Expects to hold the read lock on entry, and will release it itself.
1967  */
1968 static int
ovpn_encap(struct ovpn_softc * sc,uint32_t peerid,struct mbuf * m)1969 ovpn_encap(struct ovpn_softc *sc, uint32_t peerid, struct mbuf *m)
1970 {
1971 	struct udphdr *udp;
1972 	struct ovpn_kpeer *peer;
1973 	int len;
1974 
1975 	OVPN_RLOCK_TRACKER;
1976 
1977 	OVPN_RLOCK(sc);
1978 	NET_EPOCH_ASSERT();
1979 
1980 	peer = ovpn_find_peer(sc, peerid);
1981 	if (peer == NULL || sc->ifp->if_link_state != LINK_STATE_UP) {
1982 		OVPN_RUNLOCK(sc);
1983 		OVPN_COUNTER_ADD(sc, lost_data_pkts_out, 1);
1984 		m_freem(m);
1985 		return (ENETDOWN);
1986 	}
1987 
1988 	len = m->m_pkthdr.len;
1989 
1990 	M_PREPEND(m, sizeof(struct udphdr), M_NOWAIT);
1991 	if (m == NULL) {
1992 		OVPN_RUNLOCK(sc);
1993 		OVPN_COUNTER_ADD(sc, nomem_data_pkts_out, 1);
1994 		m_freem(m);
1995 		return (ENOBUFS);
1996 	}
1997 	udp = mtod(m, struct udphdr *);
1998 
1999 	MPASS(peer->local.ss_family == peer->remote.ss_family);
2000 
2001 	udp->uh_sport = ovpn_get_port(&peer->local);
2002 	udp->uh_dport = ovpn_get_port(&peer->remote);
2003 	udp->uh_ulen = htons(sizeof(struct udphdr) + len);
2004 
2005 	switch (peer->remote.ss_family) {
2006 #ifdef INET
2007 	case AF_INET: {
2008 		struct sockaddr_in *in_local = TO_IN(&peer->local);
2009 		struct sockaddr_in *in_remote = TO_IN(&peer->remote);
2010 		struct ip *ip;
2011 
2012 		/*
2013 		 * This requires knowing the source IP, which we don't. Happily
2014 		 * we're allowed to keep this at 0, and the checksum won't do
2015 		 * anything the crypto won't already do.
2016 		 */
2017 		udp->uh_sum = 0;
2018 
2019 		/* Set the checksum flags so we recalculate checksums. */
2020 		m->m_pkthdr.csum_flags |= CSUM_IP;
2021 		m->m_pkthdr.csum_data = offsetof(struct udphdr, uh_sum);
2022 
2023 		M_PREPEND(m, sizeof(struct ip), M_NOWAIT);
2024 		if (m == NULL) {
2025 			OVPN_RUNLOCK(sc);
2026 			OVPN_COUNTER_ADD(sc, nomem_data_pkts_out, 1);
2027 			return (ENOBUFS);
2028 		}
2029 		ip = mtod(m, struct ip *);
2030 
2031 		ip->ip_tos = 0;
2032 		ip->ip_len = htons(sizeof(struct ip) + sizeof(struct udphdr) +
2033 		   len);
2034 		ip->ip_off = 0;
2035 		ip->ip_ttl = V_ip_defttl;
2036 		ip->ip_p = IPPROTO_UDP;
2037 		ip->ip_sum = 0;
2038 		if (in_local->sin_port != 0)
2039 			ip->ip_src = in_local->sin_addr;
2040 		else
2041 			ip->ip_src.s_addr = INADDR_ANY;
2042 		ip->ip_dst = in_remote->sin_addr;
2043 
2044 		OVPN_RUNLOCK(sc);
2045 		OVPN_COUNTER_ADD(sc, transport_bytes_sent, m->m_pkthdr.len);
2046 
2047 		return (ip_output(m, NULL, NULL, 0, NULL, NULL));
2048 	}
2049 #endif
2050 #ifdef INET6
2051 	case AF_INET6: {
2052 		struct sockaddr_in6 *in6_local = TO_IN6(&peer->local);
2053 		struct sockaddr_in6 *in6_remote = TO_IN6(&peer->remote);
2054 		struct ip6_hdr *ip6;
2055 
2056 		M_PREPEND(m, sizeof(struct ip6_hdr), M_NOWAIT);
2057 		if (m == NULL) {
2058 			OVPN_RUNLOCK(sc);
2059 			OVPN_COUNTER_ADD(sc, nomem_data_pkts_out, 1);
2060 			return (ENOBUFS);
2061 		}
2062 		m = m_pullup(m, sizeof(*ip6) + sizeof(*udp));
2063 		if (m == NULL) {
2064 			OVPN_RUNLOCK(sc);
2065 			OVPN_COUNTER_ADD(sc, nomem_data_pkts_out, 1);
2066 			return (ENOBUFS);
2067 		}
2068 
2069 		ip6 = mtod(m, struct ip6_hdr *);
2070 
2071 		ip6->ip6_vfc = IPV6_VERSION;
2072 		ip6->ip6_flow &= ~IPV6_FLOWINFO_MASK;
2073 		ip6->ip6_plen = htons(sizeof(*ip6) + sizeof(struct udphdr) +
2074 		    len);
2075 		ip6->ip6_nxt = IPPROTO_UDP;
2076 		ip6->ip6_hlim = V_ip6_defhlim;
2077 
2078 		memcpy(&ip6->ip6_src, &in6_local->sin6_addr,
2079 		    sizeof(ip6->ip6_src));
2080 		memcpy(&ip6->ip6_dst, &in6_remote->sin6_addr,
2081 		    sizeof(ip6->ip6_dst));
2082 
2083 		udp = mtodo(m, sizeof(*ip6));
2084 		udp->uh_sum = in6_cksum_pseudo(ip6,
2085 		    m->m_pkthdr.len - sizeof(struct ip6_hdr),
2086 		    IPPROTO_UDP, 0);
2087 
2088 		m->m_pkthdr.csum_flags |= CSUM_UDP_IPV6;
2089 		m->m_pkthdr.csum_data = offsetof(struct udphdr, uh_sum);
2090 
2091 		OVPN_RUNLOCK(sc);
2092 		OVPN_COUNTER_ADD(sc, transport_bytes_sent, m->m_pkthdr.len);
2093 
2094 		return (ip6_output(m, NULL, NULL, IPV6_UNSPECSRC, NULL, NULL,
2095 		    NULL));
2096 	}
2097 #endif
2098 	default:
2099 		panic("Unsupported address family %d",
2100 		    peer->remote.ss_family);
2101 	}
2102 }
2103 
2104 static int
ovpn_output(struct ifnet * ifp,struct mbuf * m,const struct sockaddr * dst,struct route * ro)2105 ovpn_output(struct ifnet *ifp, struct mbuf *m, const struct sockaddr *dst,
2106 	struct route *ro)
2107 {
2108 	struct ovpn_softc *sc;
2109 	struct ovpn_kpeer *peer;
2110 
2111 	OVPN_RLOCK_TRACKER;
2112 
2113 	sc = ifp->if_softc;
2114 
2115 	m = m_unshare(m, M_NOWAIT);
2116 	if (m == NULL) {
2117 		OVPN_COUNTER_ADD(sc, lost_data_pkts_out, 1);
2118 		return (ENOBUFS);
2119 	}
2120 
2121 	OVPN_RLOCK(sc);
2122 
2123 	SDT_PROBE1(if_ovpn, tx, transmit, start, m);
2124 
2125 	if (__predict_false(ifp->if_link_state != LINK_STATE_UP)) {
2126 		OVPN_COUNTER_ADD(sc, lost_data_pkts_out, 1);
2127 		OVPN_RUNLOCK(sc);
2128 		m_freem(m);
2129 		return (ENETDOWN);
2130 	}
2131 
2132 	/**
2133 	 * Only obey 'dst' (i.e. the gateway) if no route is supplied.
2134 	 * That's our indication that we're being called through pf's route-to,
2135 	 * and we should route according to 'dst' instead. We can't do so
2136 	 * consistently, because the usual openvpn configuration sets the first
2137 	 * non-server IP in the subnet as the gateway. If we always use that
2138 	 * one we'd end up routing all traffic to the first client.
2139 	 * tl;dr: 'ro == NULL' tells us pf is doing a route-to, and then but
2140 	 * only then, we should treat 'dst' as the destination. */
2141 	peer = ovpn_route_peer(sc, &m, ro == NULL ? dst : NULL);
2142 	if (peer == NULL) {
2143 		/* No destination. */
2144 		OVPN_COUNTER_ADD(sc, lost_data_pkts_out, 1);
2145 		OVPN_RUNLOCK(sc);
2146 		m_freem(m);
2147 		return (ENETDOWN);
2148 	}
2149 
2150 	return (ovpn_transmit_to_peer(ifp, m, peer, _ovpn_lock_trackerp));
2151 }
2152 
2153 static bool
ovpn_check_replay(struct ovpn_kkey_dir * key,uint32_t seq)2154 ovpn_check_replay(struct ovpn_kkey_dir *key, uint32_t seq)
2155 {
2156 	uint32_t d;
2157 
2158 	mtx_lock(&key->replay_mtx);
2159 
2160 	/* Sequence number must be strictly greater than rx_seq */
2161 	if (seq <= key->rx_seq) {
2162 		mtx_unlock(&key->replay_mtx);
2163 		return (false);
2164 	}
2165 
2166 	/* Large jump. The packet authenticated okay, so just accept that. */
2167 	if (seq > (key->rx_seq + (sizeof(key->rx_window) * 8))) {
2168 		key->rx_seq = seq;
2169 		key->rx_window = 0;
2170 		mtx_unlock(&key->replay_mtx);
2171 		return (true);
2172 	}
2173 
2174 	/* Happy case. */
2175 	if ((seq == key->rx_seq + 1) && key->rx_window == 0) {
2176 		key->rx_seq++;
2177 		mtx_unlock(&key->replay_mtx);
2178 		return (true);
2179 	}
2180 
2181 	d = seq - key->rx_seq - 1;
2182 
2183 	if (key->rx_window & ((uint64_t)1 << d)) {
2184 		/* Dupe! */
2185 		mtx_unlock(&key->replay_mtx);
2186 		return (false);
2187 	}
2188 
2189 	key->rx_window |= (uint64_t)1 << d;
2190 
2191 	while (key->rx_window & 1) {
2192 		key->rx_seq++;
2193 		key->rx_window >>= 1;
2194 	}
2195 
2196 	mtx_unlock(&key->replay_mtx);
2197 
2198 	return (true);
2199 }
2200 
2201 static struct ovpn_kpeer *
ovpn_peer_from_mbuf(struct ovpn_softc * sc,struct mbuf * m,int off)2202 ovpn_peer_from_mbuf(struct ovpn_softc *sc, struct mbuf *m, int off)
2203 {
2204 	struct ovpn_wire_header ohdr;
2205 	uint32_t peerid;
2206 	const size_t hdrlen = sizeof(ohdr) - sizeof(ohdr.auth_tag);
2207 
2208 	OVPN_RASSERT(sc);
2209 
2210 	if (m_length(m, NULL) < (off + sizeof(struct udphdr) + hdrlen))
2211 		return (NULL);
2212 
2213 	m_copydata(m, off + sizeof(struct udphdr), hdrlen, (caddr_t)&ohdr);
2214 
2215 	peerid = ntohl(ohdr.opcode) & 0x00ffffff;
2216 
2217 	return (ovpn_find_peer(sc, peerid));
2218 }
2219 
2220 static bool
ovpn_udp_input(struct mbuf * m,int off,struct inpcb * inp,const struct sockaddr * sa,void * ctx)2221 ovpn_udp_input(struct mbuf *m, int off, struct inpcb *inp,
2222     const struct sockaddr *sa, void *ctx)
2223 {
2224 	struct ovpn_softc *sc = ctx;
2225 	struct ovpn_wire_header tmphdr;
2226 	struct ovpn_wire_header *ohdr;
2227 	struct udphdr *uhdr;
2228 	struct ovpn_kkey *key;
2229 	struct cryptop *crp;
2230 	struct ovpn_kpeer *peer;
2231 	size_t ohdrlen;
2232 	int ret;
2233 	uint8_t op;
2234 
2235 	OVPN_RLOCK_TRACKER;
2236 
2237 	M_ASSERTPKTHDR(m);
2238 
2239 	m = m_unshare(m, M_NOWAIT);
2240 	if (m == NULL) {
2241 		OVPN_COUNTER_ADD(sc, nomem_data_pkts_in, 1);
2242 		return (true);
2243 	}
2244 
2245 	OVPN_COUNTER_ADD(sc, transport_bytes_received, m->m_pkthdr.len - off);
2246 
2247 	ohdrlen = sizeof(*ohdr) - sizeof(ohdr->auth_tag);
2248 
2249 	OVPN_RLOCK(sc);
2250 
2251 	peer = ovpn_peer_from_mbuf(sc, m, off);
2252 	if (peer == NULL) {
2253 		OVPN_RUNLOCK(sc);
2254 		return (false);
2255 	}
2256 
2257 	if (m_length(m, NULL) < (off + sizeof(*uhdr) + ohdrlen)) {
2258 		/* Short packet. */
2259 		OVPN_RUNLOCK(sc);
2260 		return (false);
2261 	}
2262 
2263 	m_copydata(m, off + sizeof(*uhdr), ohdrlen, (caddr_t)&tmphdr);
2264 
2265 	op = ntohl(tmphdr.opcode) >> 24 >> OVPN_OP_SHIFT;
2266 	if (op != OVPN_OP_DATA_V2) {
2267 		/* Control packet? */
2268 		OVPN_RUNLOCK(sc);
2269 		return (false);
2270 	}
2271 
2272 	m = m_pullup(m, off + sizeof(*uhdr) + ohdrlen);
2273 	if (m == NULL) {
2274 		OVPN_RUNLOCK(sc);
2275 		OVPN_COUNTER_ADD(sc, nomem_data_pkts_in, 1);
2276 		return (true);
2277 	}
2278 
2279 	/*
2280 	 * Simplify things by getting rid of the preceding headers, we don't
2281 	 * care about them.
2282 	 */
2283 	m_adj_decap(m, off);
2284 
2285 	uhdr = mtodo(m, 0);
2286 	ohdr = mtodo(m, sizeof(*uhdr));
2287 
2288 	key = ovpn_find_key(sc, peer, ohdr);
2289 	if (key == NULL || key->decrypt == NULL) {
2290 		OVPN_RUNLOCK(sc);
2291 		OVPN_COUNTER_ADD(sc, lost_data_pkts_in, 1);
2292 		m_freem(m);
2293 		return (true);
2294 	}
2295 
2296 	if (key->decrypt->cipher == OVPN_CIPHER_ALG_NONE) {
2297 		/* Now remove the outer headers */
2298 		m_adj_decap(m, sizeof(struct udphdr) + ohdrlen);
2299 
2300 		ohdr = mtodo(m, sizeof(*uhdr));
2301 
2302 		ovpn_finish_rx(sc, m, peer, key, ntohl(ohdr->seq),
2303 		    _ovpn_lock_trackerp);
2304 		OVPN_UNLOCK_ASSERT(sc);
2305 		return (true);
2306 	}
2307 
2308 	ohdrlen += sizeof(ohdr->auth_tag);
2309 
2310 	m = m_pullup(m, sizeof(*uhdr) + ohdrlen);
2311 	if (m == NULL) {
2312 		OVPN_RUNLOCK(sc);
2313 		OVPN_COUNTER_ADD(sc, nomem_data_pkts_in, 1);
2314 		return (true);
2315 	}
2316 	uhdr = mtodo(m, 0);
2317 	ohdr = mtodo(m, sizeof(*uhdr));
2318 
2319 	/* Decrypt */
2320 	crp = crypto_getreq(key->decrypt->cryptoid, M_NOWAIT);
2321 	if (crp == NULL) {
2322 		OVPN_COUNTER_ADD(sc, nomem_data_pkts_in, 1);
2323 		OVPN_RUNLOCK(sc);
2324 		m_freem(m);
2325 		return (true);
2326 	}
2327 
2328 	crp->crp_payload_start = sizeof(struct udphdr) + sizeof(*ohdr);
2329 	crp->crp_payload_length = ntohs(uhdr->uh_ulen) -
2330 	    sizeof(*uhdr) - sizeof(*ohdr);
2331 	crp->crp_op = CRYPTO_OP_DECRYPT;
2332 
2333 	/* AAD validation. */
2334 	crp->crp_aad_length = sizeof(*ohdr) - sizeof(ohdr->auth_tag);
2335 	crp->crp_aad = ohdr;
2336 	crp->crp_aad_start = 0;
2337 	crp->crp_op |= CRYPTO_OP_VERIFY_DIGEST;
2338 	crp->crp_digest_start = sizeof(struct udphdr) +
2339 	    offsetof(struct ovpn_wire_header, auth_tag);
2340 
2341 	crp->crp_flags |= CRYPTO_F_IV_SEPARATE;
2342 	memcpy(crp->crp_iv, &ohdr->seq, sizeof(ohdr->seq));
2343 	memcpy(crp->crp_iv + sizeof(ohdr->seq), key->decrypt->nonce,
2344 	    key->decrypt->noncelen);
2345 
2346 	crypto_use_mbuf(crp, m);
2347 	crp->crp_flags |= CRYPTO_F_CBIFSYNC;
2348 	crp->crp_callback = ovpn_decrypt_rx_cb;
2349 	crp->crp_opaque = sc;
2350 
2351 	atomic_add_int(&sc->refcount, 1);
2352 	OVPN_RUNLOCK(sc);
2353 	if (V_async_crypto)
2354 		ret = crypto_dispatch_async(crp, CRYPTO_ASYNC_ORDERED);
2355 	else
2356 		ret = crypto_dispatch(crp);
2357 	if (ret != 0) {
2358 		OVPN_COUNTER_ADD(sc, lost_data_pkts_in, 1);
2359 	}
2360 
2361 	return (true);
2362 }
2363 
2364 static void
ovpn_qflush(struct ifnet * ifp __unused)2365 ovpn_qflush(struct ifnet *ifp __unused)
2366 {
2367 
2368 }
2369 
2370 static void
ovpn_flush_rxring(struct ovpn_softc * sc)2371 ovpn_flush_rxring(struct ovpn_softc *sc)
2372 {
2373 	struct ovpn_notification *n;
2374 
2375 	OVPN_WASSERT(sc);
2376 
2377 	while (! buf_ring_empty(sc->notifring)) {
2378 		n = buf_ring_dequeue_sc(sc->notifring);
2379 		free(n, M_OVPN);
2380 	}
2381 }
2382 
2383 #ifdef VIMAGE
2384 static void
ovpn_reassign(struct ifnet * ifp,struct vnet * new_vnet __unused,char * unused __unused)2385 ovpn_reassign(struct ifnet *ifp, struct vnet *new_vnet __unused,
2386     char *unused __unused)
2387 {
2388 	struct ovpn_softc *sc = ifp->if_softc;
2389 	struct ovpn_kpeer *peer, *tmppeer;
2390 	int ret __diagused;
2391 
2392 	OVPN_WLOCK(sc);
2393 
2394 	/* Flush keys & configuration. */
2395 	RB_FOREACH_SAFE(peer, ovpn_kpeers, &sc->peers, tmppeer) {
2396 		peer->del_reason = OVPN_DEL_REASON_REQUESTED;
2397 		ret = _ovpn_del_peer(sc, peer);
2398 		MPASS(ret == 0);
2399 	}
2400 
2401 	ovpn_flush_rxring(sc);
2402 
2403 	OVPN_WUNLOCK(sc);
2404 }
2405 #endif
2406 
2407 static int
ovpn_clone_match(struct if_clone * ifc,const char * name)2408 ovpn_clone_match(struct if_clone *ifc, const char *name)
2409 {
2410 	/*
2411 	 * Allow all names that start with 'ovpn', specifically because pfSense
2412 	 * uses ovpnc1 / ovpns2
2413 	 */
2414 	return (strncmp(ovpnname, name, strlen(ovpnname)) == 0);
2415 }
2416 
2417 static int
ovpn_clone_create(struct if_clone * ifc,char * name,size_t len,struct ifc_data * ifd,struct ifnet ** ifpp)2418 ovpn_clone_create(struct if_clone *ifc, char *name, size_t len,
2419     struct ifc_data *ifd, struct ifnet **ifpp)
2420 {
2421 	struct ovpn_softc *sc;
2422 	struct ifnet *ifp;
2423 	char *dp;
2424 	int error, unit, wildcard;
2425 
2426 	/* Try to see if a special unit was requested. */
2427 	error = ifc_name2unit(name, &unit);
2428 	if (error != 0)
2429 		return (error);
2430 	wildcard = (unit < 0);
2431 
2432 	error = ifc_alloc_unit(ifc, &unit);
2433 	if (error != 0)
2434 		return (error);
2435 
2436 	/*
2437 	 * If no unit had been given, we need to adjust the ifName.
2438 	 */
2439 	for (dp = name; *dp != '\0'; dp++);
2440 	if (wildcard) {
2441 		error = snprintf(dp, len - (dp - name), "%d", unit);
2442 		if (error > len - (dp - name)) {
2443 			/* ifName too long. */
2444 			ifc_free_unit(ifc, unit);
2445 			return (ENOSPC);
2446 		}
2447 		dp += error;
2448 	}
2449 
2450 	/* Make sure it doesn't already exist. */
2451 	if (ifunit(name) != NULL)
2452 		return (EEXIST);
2453 
2454 	sc = malloc(sizeof(struct ovpn_softc), M_OVPN, M_WAITOK | M_ZERO);
2455 	sc->ifp = if_alloc(IFT_ENC);
2456 	rm_init_flags(&sc->lock, "if_ovpn_lock", RM_RECURSE);
2457 	sc->refcount = 0;
2458 
2459 	sc->notifring = buf_ring_alloc(32, M_OVPN, M_WAITOK, NULL);
2460 
2461 	COUNTER_ARRAY_ALLOC(sc->counters, OVPN_COUNTER_SIZE, M_WAITOK);
2462 
2463 	ifp = sc->ifp;
2464 	ifp->if_softc = sc;
2465 	strlcpy(ifp->if_xname, name, IFNAMSIZ);
2466 	ifp->if_dname = ovpngroupname;
2467 	ifp->if_dunit = unit;
2468 
2469 	ifp->if_addrlen = 0;
2470 	ifp->if_mtu = 1428;
2471 	ifp->if_flags = IFF_POINTOPOINT | IFF_MULTICAST;
2472 	ifp->if_ioctl = ovpn_ioctl;
2473 	ifp->if_transmit = ovpn_transmit;
2474 	ifp->if_output = ovpn_output;
2475 	ifp->if_qflush = ovpn_qflush;
2476 #ifdef VIMAGE
2477 	ifp->if_reassign = ovpn_reassign;
2478 #endif
2479 	ifp->if_capabilities |= IFCAP_LINKSTATE;
2480 	ifp->if_capenable |= IFCAP_LINKSTATE;
2481 
2482 	if_attach(ifp);
2483 	bpfattach(ifp, DLT_NULL, sizeof(uint32_t));
2484 	*ifpp = ifp;
2485 
2486 	return (0);
2487 }
2488 
2489 static void
ovpn_clone_destroy_cb(struct epoch_context * ctx)2490 ovpn_clone_destroy_cb(struct epoch_context *ctx)
2491 {
2492 	struct ovpn_softc *sc;
2493 	int ret __diagused;
2494 
2495 	sc = __containerof(ctx, struct ovpn_softc, epoch_ctx);
2496 
2497 	MPASS(sc->peercount == 0);
2498 	MPASS(RB_EMPTY(&sc->peers));
2499 
2500 	if (sc->so != NULL) {
2501 		CURVNET_SET(sc->ifp->if_vnet);
2502 		ret = udp_set_kernel_tunneling(sc->so, NULL, NULL, NULL);
2503 		MPASS(ret == 0);
2504 		sorele(sc->so);
2505 		CURVNET_RESTORE();
2506 	}
2507 
2508 	COUNTER_ARRAY_FREE(sc->counters, OVPN_COUNTER_SIZE);
2509 
2510 	if_free(sc->ifp);
2511 	free(sc, M_OVPN);
2512 }
2513 
2514 static int
ovpn_clone_destroy(struct if_clone * ifc,struct ifnet * ifp,uint32_t flags)2515 ovpn_clone_destroy(struct if_clone *ifc, struct ifnet *ifp, uint32_t flags)
2516 {
2517 	struct ovpn_softc *sc;
2518 	struct ovpn_kpeer *peer, *tmppeer;
2519 	int unit;
2520 	int ret __diagused;
2521 
2522 	sc = ifp->if_softc;
2523 	unit = ifp->if_dunit;
2524 
2525 	OVPN_WLOCK(sc);
2526 
2527 	if (atomic_load_int(&sc->refcount) > 0) {
2528 		OVPN_WUNLOCK(sc);
2529 		return (EBUSY);
2530 	}
2531 
2532 	RB_FOREACH_SAFE(peer, ovpn_kpeers, &sc->peers, tmppeer) {
2533 		peer->del_reason = OVPN_DEL_REASON_REQUESTED;
2534 		ret = _ovpn_del_peer(sc, peer);
2535 		MPASS(ret == 0);
2536 	}
2537 
2538 	ovpn_flush_rxring(sc);
2539 	buf_ring_free(sc->notifring, M_OVPN);
2540 
2541 	OVPN_WUNLOCK(sc);
2542 
2543 	bpfdetach(ifp);
2544 	if_detach(ifp);
2545 	ifp->if_softc = NULL;
2546 
2547 	NET_EPOCH_CALL(ovpn_clone_destroy_cb, &sc->epoch_ctx);
2548 
2549 	if (unit != IF_DUNIT_NONE)
2550 		ifc_free_unit(ifc, unit);
2551 
2552 	NET_EPOCH_DRAIN_CALLBACKS();
2553 
2554 	return (0);
2555 }
2556 
2557 static void
vnet_ovpn_init(const void * unused __unused)2558 vnet_ovpn_init(const void *unused __unused)
2559 {
2560 	struct if_clone_addreq req = {
2561 		.match_f = ovpn_clone_match,
2562 		.create_f = ovpn_clone_create,
2563 		.destroy_f = ovpn_clone_destroy,
2564 	};
2565 	V_ovpn_cloner = ifc_attach_cloner(ovpngroupname, &req);
2566 }
2567 VNET_SYSINIT(vnet_ovpn_init, SI_SUB_PSEUDO, SI_ORDER_ANY,
2568     vnet_ovpn_init, NULL);
2569 
2570 static void
vnet_ovpn_uninit(const void * unused __unused)2571 vnet_ovpn_uninit(const void *unused __unused)
2572 {
2573 	if_clone_detach(V_ovpn_cloner);
2574 }
2575 VNET_SYSUNINIT(vnet_ovpn_uninit, SI_SUB_PSEUDO, SI_ORDER_ANY,
2576     vnet_ovpn_uninit, NULL);
2577 
2578 static int
ovpnmodevent(module_t mod,int type,void * data)2579 ovpnmodevent(module_t mod, int type, void *data)
2580 {
2581 	switch (type) {
2582 	case MOD_LOAD:
2583 		/* Done in vnet_ovpn_init() */
2584 		break;
2585 	case MOD_UNLOAD:
2586 		/* Done in vnet_ovpn_uninit() */
2587 		break;
2588 	default:
2589 		return (EOPNOTSUPP);
2590 	}
2591 
2592 	return (0);
2593 }
2594 
2595 static moduledata_t ovpn_mod = {
2596 	"if_ovpn",
2597 	ovpnmodevent,
2598 	0
2599 };
2600 
2601 DECLARE_MODULE(if_ovpn, ovpn_mod, SI_SUB_PSEUDO, SI_ORDER_ANY);
2602 MODULE_VERSION(if_ovpn, 1);
2603 MODULE_DEPEND(if_ovpn, crypto, 1, 1, 1);
2604