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/jail.h>
38 #include <sys/kernel.h>
39 #include <sys/malloc.h>
40 #include <sys/mbuf.h>
41 #include <sys/module.h>
42 #include <sys/nv.h>
43 #include <sys/osd.h>
44 #include <sys/priv.h>
45 #include <sys/protosw.h>
46 #include <sys/rmlock.h>
47 #include <sys/sdt.h>
48 #include <sys/smp.h>
49 #include <sys/socket.h>
50 #include <sys/socketvar.h>
51 #include <sys/sockio.h>
52 #include <sys/sysctl.h>
53 #include <sys/time.h>
54
55 #include <machine/atomic.h>
56
57 #include <net/bpf.h>
58 #include <net/if.h>
59 #include <net/if_clone.h>
60 #include <net/if_types.h>
61 #include <net/if_var.h>
62 #include <net/if_private.h>
63 #include <net/netisr.h>
64 #include <net/route/nhop.h>
65
66 #include <netinet/in.h>
67 #include <netinet/in_fib.h>
68 #include <netinet/ip.h>
69 #include <netinet/ip6.h>
70 #include <netinet/ip_var.h>
71 #include <netinet/udp.h>
72 #include <netinet/udp_var.h>
73
74 #include <netinet6/ip6_var.h>
75 #include <netinet6/in6_fib.h>
76
77 #include <machine/in_cksum.h>
78
79 #include <opencrypto/cryptodev.h>
80
81 #include "if_ovpn.h"
82
83 struct ovpn_kkey_dir {
84 uint8_t key[32];
85 uint8_t keylen;
86 uint8_t nonce[8];
87 uint8_t noncelen;
88 enum ovpn_key_cipher cipher;
89 crypto_session_t cryptoid;
90
91 struct mtx replay_mtx;
92 /*
93 * Last seen gapless sequence number. New rx seq numbers must be
94 * strictly higher than this.
95 */
96 uint32_t rx_seq;
97 uint64_t tx_seq;
98
99 /* Seen packets, relative to rx_seq. bit(0) will always be 0. */
100 uint64_t rx_window;
101 };
102
103 struct ovpn_kkey {
104 struct ovpn_kkey_dir *encrypt;
105 struct ovpn_kkey_dir *decrypt;
106 uint8_t keyid;
107 uint32_t peerid;
108 };
109
110 struct ovpn_keepalive {
111 uint32_t interval;
112 uint32_t timeout;
113 };
114
115 struct ovpn_wire_header {
116 uint32_t opcode; /* opcode, key id, peer id */
117 uint32_t seq;
118 uint8_t auth_tag[16];
119 };
120
121 struct ovpn_peer_counters {
122 uint64_t pkt_in;
123 uint64_t pkt_out;
124 uint64_t bytes_in;
125 uint64_t bytes_out;
126 };
127 #define OVPN_PEER_COUNTER_SIZE (sizeof(struct ovpn_peer_counters)/sizeof(uint64_t))
128
129 struct ovpn_notification {
130 enum ovpn_notif_type type;
131 uint32_t peerid;
132
133 /* Delete notification */
134 enum ovpn_del_reason del_reason;
135 struct ovpn_peer_counters counters;
136
137 /* Float notification */
138 struct sockaddr_storage address;
139 };
140
141 struct ovpn_softc;
142
143 struct ovpn_kpeer {
144 RB_ENTRY(ovpn_kpeer) tree;
145 int refcount;
146 uint32_t peerid;
147
148 struct ovpn_softc *sc;
149 struct sockaddr_storage local;
150 struct sockaddr_storage remote;
151
152 struct in_addr vpn4;
153 struct in6_addr vpn6;
154
155 struct ovpn_kkey keys[2];
156
157 enum ovpn_del_reason del_reason;
158 struct ovpn_keepalive keepalive;
159 uint32_t *last_active;
160 struct callout ping_send;
161 struct callout ping_rcv;
162
163 counter_u64_t counters[OVPN_PEER_COUNTER_SIZE];
164 };
165
166 struct ovpn_counters {
167 uint64_t lost_ctrl_pkts_in;
168 uint64_t lost_ctrl_pkts_out;
169 uint64_t lost_data_pkts_in;
170 uint64_t lost_data_pkts_out;
171 uint64_t nomem_data_pkts_in;
172 uint64_t nomem_data_pkts_out;
173 uint64_t received_ctrl_pkts;
174 uint64_t received_data_pkts;
175 uint64_t sent_ctrl_pkts;
176 uint64_t sent_data_pkts;
177
178 uint64_t transport_bytes_sent;
179 uint64_t transport_bytes_received;
180 uint64_t tunnel_bytes_sent;
181 uint64_t tunnel_bytes_received;
182 };
183 #define OVPN_COUNTER_SIZE (sizeof(struct ovpn_counters)/sizeof(uint64_t))
184
185 RB_HEAD(ovpn_kpeers, ovpn_kpeer);
186
187 struct ovpn_softc {
188 int refcount;
189 struct rmlock lock;
190 struct ifnet *ifp;
191 struct socket *so;
192 int peercount;
193 struct ovpn_kpeers peers;
194
195 /* Pending notification */
196 struct buf_ring *notifring;
197
198 counter_u64_t counters[OVPN_COUNTER_SIZE];
199
200 struct epoch_context epoch_ctx;
201 };
202
203 struct ovpn_mtag {
204 struct sockaddr_storage addr;
205 };
206
207 static struct ovpn_kpeer *ovpn_find_peer(struct ovpn_softc *, uint32_t);
208 static bool ovpn_udp_input(struct mbuf *, int, struct inpcb *,
209 const struct sockaddr *, void *);
210 static int ovpn_transmit_to_peer(struct ifnet *, struct mbuf *,
211 struct ovpn_kpeer *, struct rm_priotracker *);
212 static int ovpn_encap(struct ovpn_softc *, uint32_t, struct mbuf *);
213 static int ovpn_get_af(struct mbuf *);
214 static void ovpn_free_kkey_dir(struct ovpn_kkey_dir *);
215 static bool ovpn_check_replay(struct ovpn_kkey_dir *, uint32_t);
216 static int ovpn_peer_compare(const struct ovpn_kpeer *,
217 const struct ovpn_kpeer *);
218 static bool ovpn_sockaddr_compare(const struct sockaddr *,
219 const struct sockaddr *);
220
221 static RB_PROTOTYPE(ovpn_kpeers, ovpn_kpeer, tree, ovpn_peer_compare);
222 static RB_GENERATE(ovpn_kpeers, ovpn_kpeer, tree, ovpn_peer_compare);
223
224 #define OVPN_MTU_MIN 576
225 #define OVPN_MTU_MAX (IP_MAXPACKET - sizeof(struct ip) - \
226 sizeof(struct udphdr) - sizeof(struct ovpn_wire_header))
227
228 #define OVPN_OP_DATA_V2 0x09
229 #define OVPN_OP_SHIFT 3
230 #define OVPN_SEQ_ROTATE 0x80000000
231
232 VNET_DEFINE_STATIC(struct if_clone *, ovpn_cloner);
233 #define V_ovpn_cloner VNET(ovpn_cloner)
234
235 #define OVPN_RLOCK_TRACKER struct rm_priotracker _ovpn_lock_tracker; \
236 struct rm_priotracker *_ovpn_lock_trackerp = &_ovpn_lock_tracker
237 #define OVPN_RLOCK(sc) rm_rlock(&(sc)->lock, _ovpn_lock_trackerp)
238 #define OVPN_RUNLOCK(sc) rm_runlock(&(sc)->lock, _ovpn_lock_trackerp)
239 #define OVPN_WLOCK(sc) rm_wlock(&(sc)->lock)
240 #define OVPN_WUNLOCK(sc) rm_wunlock(&(sc)->lock)
241 #define OVPN_ASSERT(sc) rm_assert(&(sc)->lock, RA_LOCKED)
242 #define OVPN_RASSERT(sc) rm_assert(&(sc)->lock, RA_RLOCKED)
243 #define OVPN_WASSERT(sc) rm_assert(&(sc)->lock, RA_WLOCKED)
244 #define OVPN_UNLOCK_ASSERT(sc) rm_assert(&(sc)->lock, RA_UNLOCKED)
245
246 #define OVPN_COUNTER(sc, name) \
247 ((sc)->counters[offsetof(struct ovpn_counters, name)/sizeof(uint64_t)])
248 #define OVPN_PEER_COUNTER(peer, name) \
249 ((peer)->counters[offsetof(struct ovpn_peer_counters, name) / \
250 sizeof(uint64_t)])
251
252 #define OVPN_COUNTER_ADD(sc, name, val) \
253 counter_u64_add(OVPN_COUNTER(sc, name), val)
254 #define OVPN_PEER_COUNTER_ADD(p, name, val) \
255 counter_u64_add(OVPN_PEER_COUNTER(p, name), val)
256
257 #define TO_IN(x) ((struct sockaddr_in *)(x))
258 #define TO_IN6(x) ((struct sockaddr_in6 *)(x))
259
260 SDT_PROVIDER_DEFINE(if_ovpn);
261 SDT_PROBE_DEFINE1(if_ovpn, tx, transmit, start, "struct mbuf *");
262 SDT_PROBE_DEFINE2(if_ovpn, tx, route, ip4, "struct in_addr *", "struct ovpn_kpeer *");
263 SDT_PROBE_DEFINE2(if_ovpn, tx, route, ip6, "struct in6_addr *", "struct ovpn_kpeer *");
264
265 static const char ovpnname[] = "ovpn";
266 static const char ovpngroupname[] = "openvpn";
267
268 static MALLOC_DEFINE(M_OVPN, ovpnname, "OpenVPN DCO Interface");
269 #define MTAG_OVPN_LOOP 0x6f76706e /* ovpn */
270
271 SYSCTL_DECL(_net_link);
272 static SYSCTL_NODE(_net_link, IFT_OTHER, openvpn, CTLFLAG_RW | CTLFLAG_MPSAFE, 0,
273 "OpenVPN DCO Interface");
274 VNET_DEFINE_STATIC(int, replay_protection) = 0;
275 #define V_replay_protection VNET(replay_protection)
276 SYSCTL_INT(_net_link_openvpn, OID_AUTO, replay_protection, CTLFLAG_VNET | CTLFLAG_RW,
277 &VNET_NAME(replay_protection), 0, "Validate sequence numbers");
278
279 VNET_DEFINE_STATIC(int, async_crypto);
280 #define V_async_crypto VNET(async_crypto)
281 SYSCTL_INT(_net_link_openvpn, OID_AUTO, async_crypto,
282 CTLFLAG_VNET | CTLFLAG_RW, &VNET_NAME(async_crypto), 0,
283 "Use asynchronous mode to parallelize crypto jobs.");
284
285 VNET_DEFINE_STATIC(int, async_netisr_queue);
286 #define V_async_netisr_queue VNET(async_netisr_queue)
287 SYSCTL_INT(_net_link_openvpn, OID_AUTO, netisr_queue,
288 CTLFLAG_VNET | CTLFLAG_RW, &VNET_NAME(async_netisr_queue), 0,
289 "Use netisr_queue() rather than netisr_dispatch().");
290
291 static int
ovpn_peer_compare(const struct ovpn_kpeer * a,const struct ovpn_kpeer * b)292 ovpn_peer_compare(const struct ovpn_kpeer *a, const struct ovpn_kpeer *b)
293 {
294 return (a->peerid - b->peerid);
295 }
296
297 static bool
ovpn_sockaddr_compare(const struct sockaddr * a,const struct sockaddr * b)298 ovpn_sockaddr_compare(const struct sockaddr *a,
299 const struct sockaddr *b)
300 {
301 if (a->sa_family != b->sa_family)
302 return (false);
303 MPASS(a->sa_len == b->sa_len);
304
305 switch (a->sa_family) {
306 case AF_INET: {
307 const struct sockaddr_in *a4, *b4;
308
309 a4 = (const struct sockaddr_in *)a;
310 b4 = (const struct sockaddr_in *)b;
311
312 if (a4->sin_port != b4->sin_port)
313 return (false);
314
315 return (a4->sin_addr.s_addr == b4->sin_addr.s_addr);
316 }
317 case AF_INET6: {
318 const struct sockaddr_in6 *a6, *b6;
319
320 a6 = (const struct sockaddr_in6 *)a;
321 b6 = (const struct sockaddr_in6 *)b;
322
323 if (a6->sin6_port != b6->sin6_port)
324 return (false);
325 if (a6->sin6_scope_id != b6->sin6_scope_id)
326 return (false);
327
328 return (memcmp(&a6->sin6_addr, &b6->sin6_addr,
329 sizeof(a6->sin6_addr)) == 0);
330 }
331 default:
332 panic("Unknown address family %d", a->sa_family);
333 }
334 }
335
336 static struct ovpn_kpeer *
ovpn_find_peer(struct ovpn_softc * sc,uint32_t peerid)337 ovpn_find_peer(struct ovpn_softc *sc, uint32_t peerid)
338 {
339 struct ovpn_kpeer p;
340
341 OVPN_ASSERT(sc);
342
343 p.peerid = peerid;
344
345 return (RB_FIND(ovpn_kpeers, &sc->peers, &p));
346 }
347
348 static struct ovpn_kpeer *
ovpn_find_only_peer(struct ovpn_softc * sc)349 ovpn_find_only_peer(struct ovpn_softc *sc)
350 {
351 OVPN_ASSERT(sc);
352
353 return (RB_ROOT(&sc->peers));
354 }
355
356 static uint16_t
ovpn_get_port(const struct sockaddr_storage * s)357 ovpn_get_port(const struct sockaddr_storage *s)
358 {
359 switch (s->ss_family) {
360 case AF_INET: {
361 const struct sockaddr_in *in = (const struct sockaddr_in *)s;
362 return (in->sin_port);
363 }
364 case AF_INET6: {
365 const struct sockaddr_in6 *in6 = (const struct sockaddr_in6 *)s;
366 return (in6->sin6_port);
367 }
368 default:
369 panic("Unsupported address family %d", s->ss_family);
370 }
371 }
372
373 static void
ovpn_set_port(struct sockaddr_storage * s,unsigned short port)374 ovpn_set_port(struct sockaddr_storage *s, unsigned short port)
375 {
376 switch (s->ss_family) {
377 case AF_INET: {
378 struct sockaddr_in *in = (struct sockaddr_in *)s;
379 in->sin_port = port;
380 break;
381 }
382 case AF_INET6: {
383 struct sockaddr_in6 *in6 = (struct sockaddr_in6 *)s;
384 in6->sin6_port = port;
385 break;
386 }
387 default:
388 panic("Unsupported address family %d", s->ss_family);
389 }
390 }
391
392 static int
ovpn_nvlist_to_sockaddr(const nvlist_t * nvl,struct sockaddr_storage * sa)393 ovpn_nvlist_to_sockaddr(const nvlist_t *nvl, struct sockaddr_storage *sa)
394 {
395 int af;
396
397 memset(sa, 0, sizeof(*sa));
398
399 if (! nvlist_exists_number(nvl, "af"))
400 return (EINVAL);
401 if (! nvlist_exists_binary(nvl, "address"))
402 return (EINVAL);
403 if (! nvlist_exists_number(nvl, "port"))
404 return (EINVAL);
405
406 af = nvlist_get_number(nvl, "af");
407 switch (af) {
408 #ifdef INET
409 case AF_INET: {
410 struct sockaddr_in *in = (struct sockaddr_in *)sa;
411 size_t len;
412 const void *addr = nvlist_get_binary(nvl, "address", &len);
413
414 memset(in, 0, sizeof(*in));
415 in->sin_family = af;
416 in->sin_len = sizeof(*in);
417 if (len != sizeof(in->sin_addr))
418 return (EINVAL);
419
420 memcpy(&in->sin_addr, addr, sizeof(in->sin_addr));
421 in->sin_port = nvlist_get_number(nvl, "port");
422 break;
423 }
424 #endif
425 #ifdef INET6
426 case AF_INET6: {
427 struct sockaddr_in6 *in6 = (struct sockaddr_in6 *)sa;
428 size_t len;
429 const void *addr = nvlist_get_binary(nvl, "address", &len);
430
431 memset(in6, 0, sizeof(*in6));
432 in6->sin6_family = af;
433 in6->sin6_len = sizeof(*in6);
434 if (len != sizeof(in6->sin6_addr))
435 return (EINVAL);
436
437 memcpy(&in6->sin6_addr, addr, sizeof(in6->sin6_addr));
438 in6->sin6_port = nvlist_get_number(nvl, "port");
439
440 if (nvlist_exists_number(nvl, "scopeid"))
441 in6->sin6_scope_id = nvlist_get_number(nvl, "scopeid");
442
443 break;
444 }
445 #endif
446 default:
447 return (EINVAL);
448 }
449
450 return (0);
451 }
452
453 static int
ovpn_add_sockaddr(nvlist_t * parent,const char * name,const struct sockaddr * s)454 ovpn_add_sockaddr(nvlist_t *parent, const char *name, const struct sockaddr *s)
455 {
456 nvlist_t *nvl;
457
458 nvl = nvlist_create(0);
459 if (nvl == NULL)
460 return (ENOMEM);
461
462 nvlist_add_number(nvl, "af", s->sa_family);
463
464 switch (s->sa_family) {
465 case AF_INET: {
466 const struct sockaddr_in *s4 = (const struct sockaddr_in *)s;
467
468 nvlist_add_number(nvl, "port", s4->sin_port);
469 nvlist_add_binary(nvl, "address", &s4->sin_addr,
470 sizeof(s4->sin_addr));
471 break;
472 }
473 case AF_INET6: {
474 const struct sockaddr_in6 *s6 = (const struct sockaddr_in6 *)s;
475
476 nvlist_add_number(nvl, "port", s6->sin6_port);
477 nvlist_add_binary(nvl, "address", &s6->sin6_addr,
478 sizeof(s6->sin6_addr));
479 nvlist_add_number(nvl, "scopeid", s6->sin6_scope_id);
480 break;
481 }
482 default:
483 nvlist_destroy(nvl);
484 return (EINVAL);
485 }
486
487 nvlist_move_nvlist(parent, name, nvl);
488
489 return (0);
490 }
491
492 static void
ovpn_notify_del_peer(struct ovpn_softc * sc,struct ovpn_kpeer * peer)493 ovpn_notify_del_peer(struct ovpn_softc *sc, struct ovpn_kpeer *peer)
494 {
495 struct ovpn_notification *n;
496
497 OVPN_WASSERT(sc);
498
499 n = malloc(sizeof(*n), M_OVPN, M_NOWAIT);
500 if (n == NULL)
501 return;
502
503 n->peerid = peer->peerid;
504 n->type = OVPN_NOTIF_DEL_PEER;
505 n->del_reason = peer->del_reason;
506
507 n->counters.pkt_in = counter_u64_fetch(OVPN_PEER_COUNTER(peer, pkt_in));
508 n->counters.pkt_out = counter_u64_fetch(OVPN_PEER_COUNTER(peer, pkt_out));
509 n->counters.bytes_in = counter_u64_fetch(OVPN_PEER_COUNTER(peer, bytes_in));
510 n->counters.bytes_out = counter_u64_fetch(OVPN_PEER_COUNTER(peer, bytes_out));
511
512 if (buf_ring_enqueue(sc->notifring, n) != 0) {
513 free(n, M_OVPN);
514 } else if (sc->so != NULL) {
515 /* Wake up userspace */
516 sc->so->so_error = EAGAIN;
517 sorwakeup(sc->so);
518 sowwakeup(sc->so);
519 }
520 }
521
522 static void
ovpn_notify_key_rotation(struct ovpn_softc * sc,struct ovpn_kpeer * peer)523 ovpn_notify_key_rotation(struct ovpn_softc *sc, struct ovpn_kpeer *peer)
524 {
525 struct ovpn_notification *n;
526
527 n = malloc(sizeof(*n), M_OVPN, M_NOWAIT | M_ZERO);
528 if (n == NULL)
529 return;
530
531 n->peerid = peer->peerid;
532 n->type = OVPN_NOTIF_ROTATE_KEY;
533
534 if (buf_ring_enqueue(sc->notifring, n) != 0) {
535 free(n, M_OVPN);
536 } else if (sc->so != NULL) {
537 /* Wake up userspace */
538 sc->so->so_error = EAGAIN;
539 sorwakeup(sc->so);
540 sowwakeup(sc->so);
541 }
542 }
543
544 static int
ovpn_notify_float(struct ovpn_softc * sc,uint32_t peerid,const struct sockaddr_storage * remote)545 ovpn_notify_float(struct ovpn_softc *sc, uint32_t peerid,
546 const struct sockaddr_storage *remote)
547 {
548 struct ovpn_notification *n;
549
550 n = malloc(sizeof(*n), M_OVPN, M_NOWAIT | M_ZERO);
551 if (n == NULL)
552 return (ENOMEM);
553
554 n->peerid = peerid;
555 n->type = OVPN_NOTIF_FLOAT;
556 memcpy(&n->address, remote, sizeof(n->address));
557
558 if (buf_ring_enqueue(sc->notifring, n) != 0) {
559 free(n, M_OVPN);
560 return (ENOMEM);
561 } else if (sc->so != NULL) {
562 /* Wake up userspace */
563 sc->so->so_error = EAGAIN;
564 sorwakeup(sc->so);
565 sowwakeup(sc->so);
566 }
567
568 return (0);
569 }
570
571 static void
ovpn_peer_release_ref(struct ovpn_kpeer * peer,bool locked)572 ovpn_peer_release_ref(struct ovpn_kpeer *peer, bool locked)
573 {
574 struct ovpn_softc *sc;
575
576 CURVNET_ASSERT_SET();
577
578 atomic_add_int(&peer->refcount, -1);
579
580 if (atomic_load_int(&peer->refcount) > 0)
581 return;
582
583 sc = peer->sc;
584
585 if (! locked) {
586 OVPN_WLOCK(sc);
587
588 /* Might have changed before we acquired the lock. */
589 if (atomic_load_int(&peer->refcount) > 0) {
590 OVPN_WUNLOCK(sc);
591 return;
592 }
593 }
594
595 OVPN_ASSERT(sc);
596
597 /* The peer should have been removed from the list already. */
598 MPASS(ovpn_find_peer(sc, peer->peerid) == NULL);
599
600 ovpn_notify_del_peer(sc, peer);
601
602 for (int i = 0; i < 2; i++) {
603 ovpn_free_kkey_dir(peer->keys[i].encrypt);
604 ovpn_free_kkey_dir(peer->keys[i].decrypt);
605 }
606
607 callout_stop(&peer->ping_send);
608 callout_stop(&peer->ping_rcv);
609 uma_zfree_pcpu(pcpu_zone_4, peer->last_active);
610 free(peer, M_OVPN);
611
612 if (! locked)
613 OVPN_WUNLOCK(sc);
614 }
615
616 static int
ovpn_new_peer(struct ifnet * ifp,const nvlist_t * nvl)617 ovpn_new_peer(struct ifnet *ifp, const nvlist_t *nvl)
618 {
619 #ifdef INET6
620 struct epoch_tracker et;
621 #endif
622 struct sockaddr_storage local, remote;
623 struct ovpn_kpeer *peer = NULL;
624 struct file *fp = NULL;
625 struct ovpn_softc *sc = ifp->if_softc;
626 struct thread *td = curthread;
627 struct socket *so = NULL;
628 int fd;
629 uint32_t peerid;
630 int ret = 0;
631 bool setcb = false;
632
633 if (nvl == NULL)
634 return (EINVAL);
635
636 if (! nvlist_exists_number(nvl, "peerid"))
637 return (EINVAL);
638
639 if (! nvlist_exists_number(nvl, "fd"))
640 return (EINVAL);
641
642 if (! nvlist_exists_nvlist(nvl, "remote"))
643 return (EINVAL);
644
645 peerid = nvlist_get_number(nvl, "peerid");
646
647 ret = ovpn_nvlist_to_sockaddr(nvlist_get_nvlist(nvl, "remote"),
648 &remote);
649 if (ret != 0)
650 return (ret);
651
652 fd = nvlist_get_number(nvl, "fd");
653
654 /* Look up the userspace process and use the fd to find the socket. */
655 ret = getsock(td, fd, &cap_connect_rights, &fp);
656 if (ret != 0)
657 return (ret);
658
659 so = fp->f_data;
660
661 peer = malloc(sizeof(*peer), M_OVPN, M_WAITOK | M_ZERO);
662 peer->peerid = peerid;
663 peer->sc = sc;
664 peer->refcount = 1;
665 peer->last_active = uma_zalloc_pcpu(pcpu_zone_4, M_WAITOK | M_ZERO);
666 COUNTER_ARRAY_ALLOC(peer->counters, OVPN_PEER_COUNTER_SIZE, M_WAITOK);
667
668 if (nvlist_exists_binary(nvl, "vpn_ipv4")) {
669 size_t len;
670 const void *addr = nvlist_get_binary(nvl, "vpn_ipv4", &len);
671 if (len != sizeof(peer->vpn4)) {
672 ret = EINVAL;
673 goto error;
674 }
675 memcpy(&peer->vpn4, addr, len);
676 }
677
678 if (nvlist_exists_binary(nvl, "vpn_ipv6")) {
679 size_t len;
680 const void *addr = nvlist_get_binary(nvl, "vpn_ipv6", &len);
681 if (len != sizeof(peer->vpn6)) {
682 ret = EINVAL;
683 goto error;
684 }
685 memcpy(&peer->vpn6, addr, len);
686 }
687
688 callout_init_rm(&peer->ping_send, &sc->lock, CALLOUT_SHAREDLOCK);
689 callout_init_rm(&peer->ping_rcv, &sc->lock, 0);
690
691 memset(&local, 0, sizeof(local));
692 local.ss_len = sizeof(local);
693 ret = sosockaddr(so, (struct sockaddr *)&local);
694 if (ret != 0)
695 goto error;
696 if (nvlist_exists_nvlist(nvl, "local")) {
697 struct sockaddr_storage local1;
698
699 ret = ovpn_nvlist_to_sockaddr(nvlist_get_nvlist(nvl, "local"),
700 &local1);
701 if (ret != 0)
702 goto error;
703
704 /*
705 * openvpn doesn't provide a port here when in multihome mode,
706 * just steal the one the socket is bound to.
707 */
708 if (ovpn_get_port(&local1) == 0)
709 ovpn_set_port(&local1, ovpn_get_port(&local));
710 memcpy(&local, &local1, sizeof(local1));
711 }
712 if (ovpn_get_port(&local) == 0) {
713 ret = EINVAL;
714 goto error;
715 }
716 if (local.ss_family != remote.ss_family) {
717 ret = EINVAL;
718 goto error;
719 }
720
721 memcpy(&peer->local, &local, sizeof(local));
722 memcpy(&peer->remote, &remote, sizeof(remote));
723
724 #ifdef INET6
725 if (peer->local.ss_family == AF_INET6 &&
726 IN6_IS_ADDR_V4MAPPED(&TO_IN6(&peer->remote)->sin6_addr)) {
727 /* V4 mapped address, so treat this as v4, not v6. */
728 in6_sin6_2_sin_in_sock((struct sockaddr *)&peer->local);
729 in6_sin6_2_sin_in_sock((struct sockaddr *)&peer->remote);
730 }
731
732 if (peer->local.ss_family == AF_INET6 &&
733 IN6_IS_ADDR_UNSPECIFIED(&TO_IN6(&peer->local)->sin6_addr)) {
734 NET_EPOCH_ENTER(et);
735 ret = in6_selectsrc_addr(curthread->td_proc->p_fibnum,
736 &TO_IN6(&peer->remote)->sin6_addr,
737 TO_IN6(&peer->remote)->sin6_scope_id, NULL,
738 &TO_IN6(&peer->local)->sin6_addr, NULL);
739 NET_EPOCH_EXIT(et);
740 if (ret != 0) {
741 goto error;
742 }
743 }
744 #endif
745 OVPN_WLOCK(sc);
746
747 /* Disallow peer id re-use. */
748 if (ovpn_find_peer(sc, peerid) != NULL) {
749 ret = EEXIST;
750 goto error_locked;
751 }
752
753 /* Make sure this is really a UDP socket. */
754 if (so->so_type != SOCK_DGRAM || so->so_proto->pr_type != SOCK_DGRAM) {
755 ret = EPROTOTYPE;
756 goto error_locked;
757 }
758
759 /* Must be the same socket as for other peers on this interface. */
760 if (sc->so != NULL && so != sc->so) {
761 if (! RB_EMPTY(&sc->peers)) {
762 ret = EBUSY;
763 goto error_locked;
764 }
765
766 /*
767 * If we have no peers we can safely release the socket and accept
768 * a new one.
769 */
770 ret = udp_set_kernel_tunneling(sc->so, NULL, NULL, NULL);
771 MPASS(ret == 0);
772 sorele(sc->so);
773 sc->so = NULL;
774 }
775
776 if (sc->so == NULL) {
777 sc->so = so;
778 /*
779 * Maintain one extra ref so the socket doesn't go away until
780 * we're destroying the ifp.
781 */
782 soref(sc->so);
783 setcb = true;
784 }
785
786 /* Insert the peer into the list. */
787 RB_INSERT(ovpn_kpeers, &sc->peers, peer);
788 sc->peercount++;
789
790 OVPN_WUNLOCK(sc);
791
792 if (setcb) {
793 ret = udp_set_kernel_tunneling(sc->so, ovpn_udp_input, NULL, sc);
794 MPASS(ret == 0);
795 }
796
797 goto done;
798
799 error_locked:
800 OVPN_WUNLOCK(sc);
801 error:
802 COUNTER_ARRAY_FREE(peer->counters, OVPN_PEER_COUNTER_SIZE);
803 uma_zfree_pcpu(pcpu_zone_4, peer->last_active);
804 free(peer, M_OVPN);
805 done:
806 if (fp != NULL)
807 fdrop(fp, td);
808
809 return (ret);
810 }
811
812 static int
_ovpn_del_peer(struct ovpn_softc * sc,struct ovpn_kpeer * peer)813 _ovpn_del_peer(struct ovpn_softc *sc, struct ovpn_kpeer *peer)
814 {
815 struct ovpn_kpeer *tmp __diagused;
816
817 OVPN_WASSERT(sc);
818 CURVNET_ASSERT_SET();
819
820 MPASS(RB_FIND(ovpn_kpeers, &sc->peers, peer) == peer);
821
822 tmp = RB_REMOVE(ovpn_kpeers, &sc->peers, peer);
823 MPASS(tmp != NULL);
824
825 sc->peercount--;
826
827 ovpn_peer_release_ref(peer, true);
828
829 return (0);
830 }
831
832 static int
ovpn_del_peer(struct ifnet * ifp,nvlist_t * nvl)833 ovpn_del_peer(struct ifnet *ifp, nvlist_t *nvl)
834 {
835 struct ovpn_softc *sc = ifp->if_softc;
836 struct ovpn_kpeer *peer;
837 uint32_t peerid;
838 int ret;
839
840 OVPN_WASSERT(sc);
841
842 if (nvl == NULL)
843 return (EINVAL);
844
845 if (! nvlist_exists_number(nvl, "peerid"))
846 return (EINVAL);
847
848 peerid = nvlist_get_number(nvl, "peerid");
849
850 peer = ovpn_find_peer(sc, peerid);
851 if (peer == NULL)
852 return (ENOENT);
853
854 peer->del_reason = OVPN_DEL_REASON_REQUESTED;
855 ret = _ovpn_del_peer(sc, peer);
856
857 return (ret);
858 }
859
860 static int
ovpn_create_kkey_dir(struct ovpn_kkey_dir ** kdirp,const nvlist_t * nvl)861 ovpn_create_kkey_dir(struct ovpn_kkey_dir **kdirp,
862 const nvlist_t *nvl)
863 {
864 struct crypto_session_params csp;
865 struct ovpn_kkey_dir *kdir;
866 const char *ciphername;
867 enum ovpn_key_cipher cipher;
868 const void *key, *iv;
869 size_t keylen = 0, ivlen = 0;
870 int error;
871
872 if (! nvlist_exists_string(nvl, "cipher"))
873 return (EINVAL);
874 ciphername = nvlist_get_string(nvl, "cipher");
875
876 if (strcmp(ciphername, "none") == 0)
877 cipher = OVPN_CIPHER_ALG_NONE;
878 else if (strcmp(ciphername, "AES-256-GCM") == 0 ||
879 strcmp(ciphername, "AES-192-GCM") == 0 ||
880 strcmp(ciphername, "AES-128-GCM") == 0)
881 cipher = OVPN_CIPHER_ALG_AES_GCM;
882 else if (strcmp(ciphername, "CHACHA20-POLY1305") == 0)
883 cipher = OVPN_CIPHER_ALG_CHACHA20_POLY1305;
884 else
885 return (EINVAL);
886
887 if (cipher != OVPN_CIPHER_ALG_NONE) {
888 if (! nvlist_exists_binary(nvl, "key"))
889 return (EINVAL);
890 key = nvlist_get_binary(nvl, "key", &keylen);
891 if (keylen > sizeof(kdir->key))
892 return (E2BIG);
893
894 if (! nvlist_exists_binary(nvl, "iv"))
895 return (EINVAL);
896 iv = nvlist_get_binary(nvl, "iv", &ivlen);
897 if (ivlen != 8)
898 return (E2BIG);
899 }
900
901 kdir = malloc(sizeof(struct ovpn_kkey_dir), M_OVPN,
902 M_WAITOK | M_ZERO);
903
904 kdir->cipher = cipher;
905 kdir->keylen = keylen;
906 kdir->tx_seq = 1;
907 if (keylen != 0)
908 memcpy(kdir->key, key, keylen);
909 kdir->noncelen = ivlen;
910 if (ivlen != 0)
911 memcpy(kdir->nonce, iv, ivlen);
912
913 if (kdir->cipher != OVPN_CIPHER_ALG_NONE) {
914 /* Crypto init */
915 bzero(&csp, sizeof(csp));
916 csp.csp_mode = CSP_MODE_AEAD;
917
918 if (kdir->cipher == OVPN_CIPHER_ALG_CHACHA20_POLY1305)
919 csp.csp_cipher_alg = CRYPTO_CHACHA20_POLY1305;
920 else
921 csp.csp_cipher_alg = CRYPTO_AES_NIST_GCM_16;
922
923 csp.csp_flags |= CSP_F_SEPARATE_AAD;
924
925 csp.csp_cipher_klen = kdir->keylen;
926 csp.csp_cipher_key = kdir->key;
927 csp.csp_ivlen = 96 / 8;
928
929 error = crypto_newsession(&kdir->cryptoid, &csp,
930 CRYPTOCAP_F_HARDWARE | CRYPTOCAP_F_SOFTWARE);
931 if (error) {
932 free(kdir, M_OVPN);
933 return (error);
934 }
935 }
936
937 mtx_init(&kdir->replay_mtx, "if_ovpn rx replay", NULL, MTX_DEF);
938 *kdirp = kdir;
939
940 return (0);
941 }
942
943 static void
ovpn_free_kkey_dir(struct ovpn_kkey_dir * kdir)944 ovpn_free_kkey_dir(struct ovpn_kkey_dir *kdir)
945 {
946 if (kdir == NULL)
947 return;
948
949 mtx_destroy(&kdir->replay_mtx);
950
951 crypto_freesession(kdir->cryptoid);
952 free(kdir, M_OVPN);
953 }
954
955 static int
ovpn_set_key(struct ifnet * ifp,const nvlist_t * nvl)956 ovpn_set_key(struct ifnet *ifp, const nvlist_t *nvl)
957 {
958 struct ovpn_softc *sc = ifp->if_softc;
959 struct ovpn_kkey_dir *enc, *dec;
960 struct ovpn_kpeer *peer;
961 int slot, keyid, peerid;
962 int error;
963
964 if (nvl == NULL)
965 return (EINVAL);
966
967 if (! nvlist_exists_number(nvl, "slot"))
968 return (EINVAL);
969 slot = nvlist_get_number(nvl, "slot");
970
971 if (! nvlist_exists_number(nvl, "keyid"))
972 return (EINVAL);
973 keyid = nvlist_get_number(nvl, "keyid");
974
975 if (! nvlist_exists_number(nvl, "peerid"))
976 return (EINVAL);
977 peerid = nvlist_get_number(nvl, "peerid");
978
979 if (slot != OVPN_KEY_SLOT_PRIMARY &&
980 slot != OVPN_KEY_SLOT_SECONDARY)
981 return (EINVAL);
982
983 if (! nvlist_exists_nvlist(nvl, "encrypt") ||
984 ! nvlist_exists_nvlist(nvl, "decrypt"))
985 return (EINVAL);
986
987 error = ovpn_create_kkey_dir(&enc, nvlist_get_nvlist(nvl, "encrypt"));
988 if (error)
989 return (error);
990
991 error = ovpn_create_kkey_dir(&dec, nvlist_get_nvlist(nvl, "decrypt"));
992 if (error) {
993 ovpn_free_kkey_dir(enc);
994 return (error);
995 }
996
997 OVPN_WLOCK(sc);
998
999 peer = ovpn_find_peer(sc, peerid);
1000 if (peer == NULL) {
1001 ovpn_free_kkey_dir(dec);
1002 ovpn_free_kkey_dir(enc);
1003 OVPN_WUNLOCK(sc);
1004 return (ENOENT);
1005 }
1006
1007 ovpn_free_kkey_dir(peer->keys[slot].encrypt);
1008 ovpn_free_kkey_dir(peer->keys[slot].decrypt);
1009
1010 peer->keys[slot].encrypt = enc;
1011 peer->keys[slot].decrypt = dec;
1012
1013 peer->keys[slot].keyid = keyid;
1014 peer->keys[slot].peerid = peerid;
1015
1016 OVPN_WUNLOCK(sc);
1017
1018 return (0);
1019 }
1020
1021 static int
ovpn_check_key(struct ovpn_softc * sc,struct ovpn_kpeer * peer,enum ovpn_key_slot slot)1022 ovpn_check_key(struct ovpn_softc *sc, struct ovpn_kpeer *peer, enum ovpn_key_slot slot)
1023 {
1024 OVPN_ASSERT(sc);
1025
1026 if (peer->keys[slot].encrypt == NULL)
1027 return (ENOLINK);
1028
1029 if (peer->keys[slot].decrypt == NULL)
1030 return (ENOLINK);
1031
1032 return (0);
1033 }
1034
1035 static int
ovpn_start(struct ifnet * ifp)1036 ovpn_start(struct ifnet *ifp)
1037 {
1038 struct ovpn_softc *sc = ifp->if_softc;
1039
1040 OVPN_WLOCK(sc);
1041
1042 ifp->if_flags |= IFF_UP;
1043 ifp->if_drv_flags |= IFF_DRV_RUNNING;
1044 if_link_state_change(ifp, LINK_STATE_UP);
1045
1046 OVPN_WUNLOCK(sc);
1047
1048 return (0);
1049 }
1050
1051 static int
ovpn_swap_keys(struct ifnet * ifp,nvlist_t * nvl)1052 ovpn_swap_keys(struct ifnet *ifp, nvlist_t *nvl)
1053 {
1054 struct ovpn_softc *sc = ifp->if_softc;
1055 struct ovpn_kpeer *peer;
1056 struct ovpn_kkey tmpkey;
1057 int error;
1058
1059 if (nvl == NULL)
1060 return (EINVAL);
1061
1062 if (! nvlist_exists_number(nvl, "peerid"))
1063 return (EINVAL);
1064
1065 OVPN_WLOCK(sc);
1066
1067 peer = ovpn_find_peer(sc, nvlist_get_number(nvl, "peerid"));
1068 if (peer == NULL) {
1069 OVPN_WUNLOCK(sc);
1070 return (ENOENT);
1071 }
1072
1073 /* Check that we have a second key to swap to. */
1074 error = ovpn_check_key(sc, peer, OVPN_KEY_SLOT_SECONDARY);
1075 if (error) {
1076 OVPN_WUNLOCK(sc);
1077 return (error);
1078 }
1079
1080 tmpkey = peer->keys[0];
1081 peer->keys[0] = peer->keys[1];
1082 peer->keys[1] = tmpkey;
1083
1084 OVPN_WUNLOCK(sc);
1085
1086 return (0);
1087 }
1088
1089 static int
ovpn_del_key(struct ifnet * ifp,const nvlist_t * nvl)1090 ovpn_del_key(struct ifnet *ifp, const nvlist_t *nvl)
1091 {
1092 enum ovpn_key_slot slot;
1093 struct ovpn_kpeer *peer;
1094 struct ovpn_softc *sc = ifp->if_softc;
1095
1096 if (nvl == NULL)
1097 return (EINVAL);
1098
1099 if (! nvlist_exists_number(nvl, "peerid"))
1100 return (EINVAL);
1101
1102 if (! nvlist_exists_number(nvl, "slot"))
1103 return (EINVAL);
1104 slot = nvlist_get_number(nvl, "slot");
1105
1106 if (slot != OVPN_KEY_SLOT_PRIMARY &&
1107 slot != OVPN_KEY_SLOT_SECONDARY)
1108 return (EINVAL);
1109
1110 OVPN_WLOCK(sc);
1111
1112 peer = ovpn_find_peer(sc, nvlist_get_number(nvl, "peerid"));
1113 if (peer == NULL) {
1114 OVPN_WUNLOCK(sc);
1115 return (ENOENT);
1116 }
1117
1118 ovpn_free_kkey_dir(peer->keys[slot].encrypt);
1119 ovpn_free_kkey_dir(peer->keys[slot].decrypt);
1120
1121 peer->keys[slot].encrypt = NULL;
1122 peer->keys[slot].decrypt = NULL;
1123
1124 peer->keys[slot].keyid = 0;
1125 peer->keys[slot].peerid = 0;
1126
1127 OVPN_WUNLOCK(sc);
1128
1129 return (0);
1130 }
1131
1132 static void
ovpn_send_ping(void * arg)1133 ovpn_send_ping(void *arg)
1134 {
1135 static const uint8_t ping_str[] = {
1136 0x2a, 0x18, 0x7b, 0xf3, 0x64, 0x1e, 0xb4, 0xcb,
1137 0x07, 0xed, 0x2d, 0x0a, 0x98, 0x1f, 0xc7, 0x48
1138 };
1139
1140 struct epoch_tracker et;
1141 struct ovpn_kpeer *peer = arg;
1142 struct ovpn_softc *sc = peer->sc;
1143 struct mbuf *m;
1144
1145 OVPN_RASSERT(sc);
1146
1147 /* Ensure we repeat! */
1148 callout_reset(&peer->ping_send, peer->keepalive.interval * hz,
1149 ovpn_send_ping, peer);
1150
1151 m = m_get2(sizeof(ping_str), M_NOWAIT, MT_DATA, M_PKTHDR);
1152 if (m == NULL)
1153 return;
1154
1155 m_copyback(m, 0, sizeof(ping_str), ping_str);
1156 m->m_len = m->m_pkthdr.len = sizeof(ping_str);
1157
1158 CURVNET_SET(sc->ifp->if_vnet);
1159 NET_EPOCH_ENTER(et);
1160 (void)ovpn_transmit_to_peer(sc->ifp, m, peer, NULL);
1161 NET_EPOCH_EXIT(et);
1162 CURVNET_RESTORE();
1163 }
1164
1165 static void
ovpn_timeout(void * arg)1166 ovpn_timeout(void *arg)
1167 {
1168 struct ovpn_kpeer *peer = arg;
1169 struct ovpn_softc *sc = peer->sc;
1170 uint32_t last, _last_active;
1171 int ret __diagused;
1172 int cpu;
1173
1174 OVPN_WASSERT(sc);
1175
1176 last = 0;
1177 CPU_FOREACH(cpu) {
1178 _last_active = *zpcpu_get_cpu(peer->last_active, cpu);
1179 if (_last_active > last)
1180 last = _last_active;
1181 }
1182
1183 if (last + peer->keepalive.timeout > time_uptime) {
1184 callout_reset(&peer->ping_rcv,
1185 (peer->keepalive.timeout - (time_uptime - last)) * hz,
1186 ovpn_timeout, peer);
1187 return;
1188 }
1189
1190 CURVNET_SET(sc->ifp->if_vnet);
1191 peer->del_reason = OVPN_DEL_REASON_TIMEOUT;
1192 ret = _ovpn_del_peer(sc, peer);
1193 MPASS(ret == 0);
1194 CURVNET_RESTORE();
1195 }
1196
1197 static int
ovpn_set_peer(struct ifnet * ifp,const nvlist_t * nvl)1198 ovpn_set_peer(struct ifnet *ifp, const nvlist_t *nvl)
1199 {
1200 struct ovpn_softc *sc = ifp->if_softc;
1201 struct ovpn_kpeer *peer;
1202
1203 if (nvl == NULL)
1204 return (EINVAL);
1205
1206 if (! nvlist_exists_number(nvl, "interval") ||
1207 ! nvlist_exists_number(nvl, "timeout") ||
1208 ! nvlist_exists_number(nvl, "peerid"))
1209 return (EINVAL);
1210
1211 OVPN_WLOCK(sc);
1212
1213 peer = ovpn_find_peer(sc, nvlist_get_number(nvl, "peerid"));
1214 if (peer == NULL) {
1215 OVPN_WUNLOCK(sc);
1216 return (ENOENT);
1217 }
1218
1219 peer->keepalive.interval = nvlist_get_number(nvl, "interval");
1220 peer->keepalive.timeout = nvlist_get_number(nvl, "timeout");
1221
1222 if (peer->keepalive.interval > 0)
1223 callout_reset(&peer->ping_send, peer->keepalive.interval * hz,
1224 ovpn_send_ping, peer);
1225 if (peer->keepalive.timeout > 0)
1226 callout_reset(&peer->ping_rcv, peer->keepalive.timeout * hz,
1227 ovpn_timeout, peer);
1228
1229 OVPN_WUNLOCK(sc);
1230
1231 return (0);
1232 }
1233
1234 static int
ovpn_set_ifmode(struct ifnet * ifp,const nvlist_t * nvl)1235 ovpn_set_ifmode(struct ifnet *ifp, const nvlist_t *nvl)
1236 {
1237 struct ovpn_softc *sc = ifp->if_softc;
1238 int ifmode;
1239
1240 if (nvl == NULL)
1241 return (EINVAL);
1242
1243 if (! nvlist_exists_number(nvl, "ifmode") )
1244 return (EINVAL);
1245
1246 ifmode = nvlist_get_number(nvl, "ifmode");
1247
1248 OVPN_WLOCK(sc);
1249
1250 /* deny this if UP */
1251 if (ifp->if_flags & IFF_UP) {
1252 OVPN_WUNLOCK(sc);
1253 return (EBUSY);
1254 }
1255
1256 switch (ifmode & ~IFF_MULTICAST) {
1257 case IFF_POINTOPOINT:
1258 case IFF_BROADCAST:
1259 ifp->if_flags &=
1260 ~(IFF_BROADCAST|IFF_POINTOPOINT|IFF_MULTICAST);
1261 ifp->if_flags |= ifmode;
1262 break;
1263 default:
1264 OVPN_WUNLOCK(sc);
1265 return (EINVAL);
1266 }
1267
1268 OVPN_WUNLOCK(sc);
1269
1270 return (0);
1271 }
1272
1273 static int
ovpn_ioctl_set(struct ifnet * ifp,struct ifdrv * ifd)1274 ovpn_ioctl_set(struct ifnet *ifp, struct ifdrv *ifd)
1275 {
1276 struct ovpn_softc *sc = ifp->if_softc;
1277 uint8_t *buf = NULL;
1278 nvlist_t *nvl = NULL;
1279 int ret;
1280
1281 if (ifd->ifd_len != 0) {
1282 if (ifd->ifd_len > OVPN_MAX_REQUEST_SIZE)
1283 return (E2BIG);
1284
1285 buf = malloc(ifd->ifd_len, M_OVPN, M_WAITOK);
1286
1287 ret = copyin(ifd->ifd_data, buf, ifd->ifd_len);
1288 if (ret != 0) {
1289 free(buf, M_OVPN);
1290 return (ret);
1291 }
1292
1293 nvl = nvlist_unpack(buf, ifd->ifd_len, 0);
1294 free(buf, M_OVPN);
1295 if (nvl == NULL) {
1296 return (EINVAL);
1297 }
1298 }
1299
1300 switch (ifd->ifd_cmd) {
1301 case OVPN_NEW_PEER:
1302 ret = ovpn_new_peer(ifp, nvl);
1303 break;
1304 case OVPN_DEL_PEER:
1305 OVPN_WLOCK(sc);
1306 ret = ovpn_del_peer(ifp, nvl);
1307 OVPN_WUNLOCK(sc);
1308 break;
1309 case OVPN_NEW_KEY:
1310 ret = ovpn_set_key(ifp, nvl);
1311 break;
1312 case OVPN_START_VPN:
1313 ret = ovpn_start(ifp);
1314 break;
1315 case OVPN_SWAP_KEYS:
1316 ret = ovpn_swap_keys(ifp, nvl);
1317 break;
1318 case OVPN_DEL_KEY:
1319 ret = ovpn_del_key(ifp, nvl);
1320 break;
1321 case OVPN_SET_PEER:
1322 ret = ovpn_set_peer(ifp, nvl);
1323 break;
1324 case OVPN_SET_IFMODE:
1325 ret = ovpn_set_ifmode(ifp, nvl);
1326 break;
1327 default:
1328 ret = ENOTSUP;
1329 }
1330
1331 nvlist_destroy(nvl);
1332 return (ret);
1333 }
1334
1335 static int
ovpn_add_counters(nvlist_t * parent,const char * name,counter_u64_t in,counter_u64_t out)1336 ovpn_add_counters(nvlist_t *parent, const char *name, counter_u64_t in,
1337 counter_u64_t out)
1338 {
1339 nvlist_t *nvl;
1340
1341 nvl = nvlist_create(0);
1342 if (nvl == NULL)
1343 return (ENOMEM);
1344
1345 nvlist_add_number(nvl, "in", counter_u64_fetch(in));
1346 nvlist_add_number(nvl, "out", counter_u64_fetch(out));
1347
1348 nvlist_add_nvlist(parent, name, nvl);
1349
1350 nvlist_destroy(nvl);
1351
1352 return (0);
1353 }
1354
1355 static int
ovpn_get_stats(struct ovpn_softc * sc,nvlist_t ** onvl)1356 ovpn_get_stats(struct ovpn_softc *sc, nvlist_t **onvl)
1357 {
1358 nvlist_t *nvl;
1359 int ret;
1360
1361 nvl = nvlist_create(0);
1362 if (nvl == NULL)
1363 return (ENOMEM);
1364
1365 #define OVPN_COUNTER_OUT(name, in, out) \
1366 do { \
1367 ret = ovpn_add_counters(nvl, name, OVPN_COUNTER(sc, in), \
1368 OVPN_COUNTER(sc, out)); \
1369 if (ret != 0) \
1370 goto error; \
1371 } while(0)
1372
1373 OVPN_COUNTER_OUT("lost_ctrl", lost_ctrl_pkts_in, lost_ctrl_pkts_out);
1374 OVPN_COUNTER_OUT("lost_data", lost_data_pkts_in, lost_data_pkts_out);
1375 OVPN_COUNTER_OUT("nomem_data", nomem_data_pkts_in,
1376 nomem_data_pkts_out);
1377 OVPN_COUNTER_OUT("data", received_data_pkts, sent_data_pkts);
1378 OVPN_COUNTER_OUT("ctrl", received_ctrl_pkts, sent_ctrl_pkts);
1379 OVPN_COUNTER_OUT("tunnel", tunnel_bytes_received,
1380 tunnel_bytes_received);
1381 OVPN_COUNTER_OUT("transport", transport_bytes_received,
1382 transport_bytes_received);
1383 #undef OVPN_COUNTER_OUT
1384
1385 *onvl = nvl;
1386
1387 return (0);
1388
1389 error:
1390 nvlist_destroy(nvl);
1391 return (ret);
1392 }
1393
1394 static int
ovpn_get_peer_stats(struct ovpn_softc * sc,nvlist_t ** nvl)1395 ovpn_get_peer_stats(struct ovpn_softc *sc, nvlist_t **nvl)
1396 {
1397 struct ovpn_kpeer *peer;
1398 nvlist_t *nvpeer = NULL;
1399 int ret;
1400
1401 OVPN_RLOCK_TRACKER;
1402
1403 *nvl = nvlist_create(0);
1404 if (*nvl == NULL)
1405 return (ENOMEM);
1406
1407 #define OVPN_PEER_COUNTER_OUT(name, in, out) \
1408 do { \
1409 ret = ovpn_add_counters(nvpeer, name, \
1410 OVPN_PEER_COUNTER(peer, in), OVPN_PEER_COUNTER(peer, out)); \
1411 if (ret != 0) \
1412 goto error; \
1413 } while(0)
1414
1415 OVPN_RLOCK(sc);
1416 RB_FOREACH(peer, ovpn_kpeers, &sc->peers) {
1417 nvpeer = nvlist_create(0);
1418 if (nvpeer == NULL) {
1419 OVPN_RUNLOCK(sc);
1420 nvlist_destroy(*nvl);
1421 *nvl = NULL;
1422 return (ENOMEM);
1423 }
1424
1425 nvlist_add_number(nvpeer, "peerid", peer->peerid);
1426
1427 OVPN_PEER_COUNTER_OUT("packets", pkt_in, pkt_out);
1428 OVPN_PEER_COUNTER_OUT("bytes", bytes_in, bytes_out);
1429
1430 nvlist_append_nvlist_array(*nvl, "peers", nvpeer);
1431 nvlist_destroy(nvpeer);
1432 }
1433 #undef OVPN_PEER_COUNTER_OUT
1434 OVPN_RUNLOCK(sc);
1435
1436 return (0);
1437
1438 error:
1439 nvlist_destroy(nvpeer);
1440 nvlist_destroy(*nvl);
1441 *nvl = NULL;
1442 return (ret);
1443 }
1444
1445 static int
ovpn_poll_pkt(struct ovpn_softc * sc,nvlist_t ** onvl)1446 ovpn_poll_pkt(struct ovpn_softc *sc, nvlist_t **onvl)
1447 {
1448 nvlist_t *nvl;
1449
1450 nvl = nvlist_create(0);
1451 if (nvl == NULL)
1452 return (ENOMEM);
1453
1454 nvlist_add_number(nvl, "pending", buf_ring_count(sc->notifring));
1455
1456 *onvl = nvl;
1457
1458 return (0);
1459 }
1460
1461 static void
ovpn_notif_add_counters(nvlist_t * parent,struct ovpn_notification * n)1462 ovpn_notif_add_counters(nvlist_t *parent, struct ovpn_notification *n)
1463 {
1464 nvlist_t *nvl;
1465
1466 nvl = nvlist_create(0);
1467 if (nvl == NULL)
1468 return;
1469
1470 nvlist_add_number(nvl, "in", n->counters.pkt_in);
1471 nvlist_add_number(nvl, "out", n->counters.pkt_out);
1472
1473 nvlist_add_nvlist(parent, "packets", nvl);
1474 nvlist_destroy(nvl);
1475
1476 nvl = nvlist_create(0);
1477 if (nvl == NULL)
1478 return;
1479
1480 nvlist_add_number(nvl, "in", n->counters.bytes_in);
1481 nvlist_add_number(nvl, "out", n->counters.bytes_out);
1482
1483 nvlist_add_nvlist(parent, "bytes", nvl);
1484 nvlist_destroy(nvl);
1485 }
1486
1487 static int
opvn_get_pkt(struct ovpn_softc * sc,nvlist_t ** onvl)1488 opvn_get_pkt(struct ovpn_softc *sc, nvlist_t **onvl)
1489 {
1490 struct ovpn_notification *n;
1491 nvlist_t *nvl;
1492
1493 /* Check if we have notifications pending. */
1494 n = buf_ring_dequeue_mc(sc->notifring);
1495 if (n == NULL)
1496 return (ENOENT);
1497
1498 nvl = nvlist_create(0);
1499 if (nvl == NULL) {
1500 free(n, M_OVPN);
1501 return (ENOMEM);
1502 }
1503 nvlist_add_number(nvl, "peerid", n->peerid);
1504 nvlist_add_number(nvl, "notification", n->type);
1505 switch (n->type) {
1506 case OVPN_NOTIF_DEL_PEER: {
1507 nvlist_add_number(nvl, "del_reason", n->del_reason);
1508
1509 /* No error handling, because we want to send the notification
1510 * even if we can't attach the counters. */
1511 ovpn_notif_add_counters(nvl, n);
1512 break;
1513 }
1514 case OVPN_NOTIF_FLOAT: {
1515 int ret;
1516
1517 ret = ovpn_add_sockaddr(nvl, "address",
1518 (struct sockaddr *)&n->address);
1519
1520 if (ret) {
1521 /*
1522 * Try to re-enqueue the notification. Maybe we'll
1523 * have better luck next time. No error handling,
1524 * because if we fail to re-enqueue there's nothing we can do.
1525 */
1526 (void)ovpn_notify_float(sc, n->peerid, &n->address);
1527 nvlist_destroy(nvl);
1528 free(n, M_OVPN);
1529 return (ret);
1530 }
1531 break;
1532 }
1533 default:
1534 break;
1535 }
1536 free(n, M_OVPN);
1537
1538 *onvl = nvl;
1539
1540 return (0);
1541 }
1542
1543 static int
ovpn_ioctl_get(struct ifnet * ifp,struct ifdrv * ifd)1544 ovpn_ioctl_get(struct ifnet *ifp, struct ifdrv *ifd)
1545 {
1546 struct ovpn_softc *sc = ifp->if_softc;
1547 nvlist_t *nvl = NULL;
1548 int error;
1549
1550 switch (ifd->ifd_cmd) {
1551 case OVPN_GET_STATS:
1552 error = ovpn_get_stats(sc, &nvl);
1553 break;
1554 case OVPN_GET_PEER_STATS:
1555 error = ovpn_get_peer_stats(sc, &nvl);
1556 break;
1557 case OVPN_POLL_PKT:
1558 error = ovpn_poll_pkt(sc, &nvl);
1559 break;
1560 case OVPN_GET_PKT:
1561 error = opvn_get_pkt(sc, &nvl);
1562 break;
1563 default:
1564 error = ENOTSUP;
1565 break;
1566 }
1567
1568 if (error == 0) {
1569 void *packed = NULL;
1570 size_t len;
1571
1572 MPASS(nvl != NULL);
1573
1574 packed = nvlist_pack(nvl, &len);
1575 if (! packed) {
1576 nvlist_destroy(nvl);
1577 return (ENOMEM);
1578 }
1579
1580 if (len > ifd->ifd_len) {
1581 free(packed, M_NVLIST);
1582 nvlist_destroy(nvl);
1583 return (ENOSPC);
1584 }
1585
1586 error = copyout(packed, ifd->ifd_data, len);
1587 ifd->ifd_len = len;
1588
1589 free(packed, M_NVLIST);
1590 nvlist_destroy(nvl);
1591 }
1592
1593 return (error);
1594 }
1595
1596 static int
ovpn_ioctl(struct ifnet * ifp,u_long cmd,caddr_t data)1597 ovpn_ioctl(struct ifnet *ifp, u_long cmd, caddr_t data)
1598 {
1599 struct ifdrv *ifd;
1600 int error;
1601
1602 CURVNET_ASSERT_SET();
1603
1604 switch (cmd) {
1605 case SIOCSDRVSPEC:
1606 case SIOCGDRVSPEC:
1607 error = priv_check(curthread, PRIV_NET_OVPN);
1608 if (error)
1609 return (error);
1610 break;
1611 }
1612
1613 switch (cmd) {
1614 case SIOCSDRVSPEC:
1615 ifd = (struct ifdrv *)data;
1616 error = ovpn_ioctl_set(ifp, ifd);
1617 break;
1618 case SIOCGDRVSPEC:
1619 ifd = (struct ifdrv *)data;
1620 error = ovpn_ioctl_get(ifp, ifd);
1621 break;
1622 case SIOCSIFMTU: {
1623 struct ifreq *ifr = (struct ifreq *)data;
1624 if (ifr->ifr_mtu < OVPN_MTU_MIN || ifr->ifr_mtu > OVPN_MTU_MAX)
1625 return (EINVAL);
1626
1627 ifp->if_mtu = ifr->ifr_mtu;
1628 return (0);
1629 }
1630 case SIOCSIFADDR:
1631 case SIOCADDMULTI:
1632 case SIOCDELMULTI:
1633 case SIOCGIFMTU:
1634 case SIOCSIFFLAGS:
1635 return (0);
1636 default:
1637 error = EINVAL;
1638 }
1639
1640 return (error);
1641 }
1642
1643 static int
ovpn_encrypt_tx_cb(struct cryptop * crp)1644 ovpn_encrypt_tx_cb(struct cryptop *crp)
1645 {
1646 struct epoch_tracker et;
1647 struct ovpn_kpeer *peer = crp->crp_opaque;
1648 struct ovpn_softc *sc = peer->sc;
1649 struct mbuf *m = crp->crp_buf.cb_mbuf;
1650 int tunnel_len;
1651 int ret;
1652
1653 CURVNET_SET(sc->ifp->if_vnet);
1654 NET_EPOCH_ENTER(et);
1655
1656 if (crp->crp_etype != 0) {
1657 crypto_freereq(crp);
1658 ovpn_peer_release_ref(peer, false);
1659 NET_EPOCH_EXIT(et);
1660 CURVNET_RESTORE();
1661 OVPN_COUNTER_ADD(sc, lost_data_pkts_out, 1);
1662 m_freem(m);
1663 return (0);
1664 }
1665
1666 MPASS(crp->crp_buf.cb_type == CRYPTO_BUF_MBUF);
1667
1668 tunnel_len = m->m_pkthdr.len - sizeof(struct ovpn_wire_header);
1669 ret = ovpn_encap(sc, peer->peerid, m);
1670 if (ret == 0) {
1671 OVPN_COUNTER_ADD(sc, sent_data_pkts, 1);
1672 OVPN_COUNTER_ADD(sc, tunnel_bytes_sent, tunnel_len);
1673 }
1674
1675 crypto_freereq(crp);
1676 ovpn_peer_release_ref(peer, false);
1677
1678 NET_EPOCH_EXIT(et);
1679 CURVNET_RESTORE();
1680
1681 return (0);
1682 }
1683
1684 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)1685 ovpn_finish_rx(struct ovpn_softc *sc, struct mbuf *m,
1686 struct ovpn_kpeer *peer, struct ovpn_kkey *key, uint32_t seq,
1687 struct rm_priotracker *_ovpn_lock_trackerp)
1688 {
1689 uint32_t af;
1690 struct m_tag *mtag;
1691
1692 OVPN_RASSERT(sc);
1693 NET_EPOCH_ASSERT();
1694
1695 /* Replay protection. */
1696 if (V_replay_protection && ! ovpn_check_replay(key->decrypt, seq)) {
1697 OVPN_RUNLOCK(sc);
1698 OVPN_COUNTER_ADD(sc, lost_data_pkts_in, 1);
1699 m_freem(m);
1700 return;
1701 }
1702
1703 critical_enter();
1704 *zpcpu_get(peer->last_active) = time_uptime;
1705 critical_exit();
1706
1707 OVPN_RUNLOCK(sc);
1708
1709 /* Check if the peer changed to a new source address. */
1710 mtag = m_tag_find(m, PACKET_TAG_OVPN, NULL);
1711 if (mtag != NULL) {
1712 struct ovpn_mtag *ot = (struct ovpn_mtag *)(mtag + 1);
1713
1714 OVPN_WLOCK(sc);
1715
1716 /*
1717 * Check the address against the peer's remote again, because we may race
1718 * against ourselves (i.e. we may have tagged multiple packets to indicate we
1719 * floated).
1720 */
1721 if (ovpn_sockaddr_compare((struct sockaddr *)&ot->addr,
1722 (struct sockaddr *)&peer->remote)) {
1723 OVPN_WUNLOCK(sc);
1724 goto skip_float;
1725 }
1726
1727 /* And notify userspace. */
1728 if (ovpn_notify_float(sc, peer->peerid, &ot->addr) == 0) {
1729 /*
1730 * Update the 'remote' for this peer, but only if
1731 * we've actually enqueued the notification.
1732 * Otherwise we can try again later.
1733 */
1734 memcpy(&peer->remote, &ot->addr, sizeof(peer->remote));
1735 }
1736
1737 OVPN_WUNLOCK(sc);
1738 }
1739
1740 skip_float:
1741 OVPN_COUNTER_ADD(sc, received_data_pkts, 1);
1742 OVPN_COUNTER_ADD(sc, tunnel_bytes_received, m->m_pkthdr.len);
1743 OVPN_PEER_COUNTER_ADD(peer, pkt_in, 1);
1744 OVPN_PEER_COUNTER_ADD(peer, bytes_in, m->m_pkthdr.len);
1745
1746 /* Receive the packet on our interface. */
1747 m->m_pkthdr.rcvif = sc->ifp;
1748
1749 /* Clear checksum flags in case the real hardware set them. */
1750 m->m_pkthdr.csum_flags = 0;
1751
1752 /* Clear mbuf tags & flags */
1753 m_tag_delete_nonpersistent(m);
1754 m_clrprotoflags(m);
1755
1756 /* Ensure we can read the first byte. */
1757 m = m_pullup(m, 1);
1758 if (m == NULL) {
1759 OVPN_COUNTER_ADD(sc, nomem_data_pkts_in, 1);
1760 return;
1761 }
1762
1763 /*
1764 * Check for address family, and disregard any control packets (e.g.
1765 * keepalive).
1766 */
1767 af = ovpn_get_af(m);
1768 if (af != 0) {
1769 BPF_MTAP2(sc->ifp, &af, sizeof(af), m);
1770 if (V_async_netisr_queue)
1771 netisr_queue(af == AF_INET ? NETISR_IP : NETISR_IPV6, m);
1772 else
1773 netisr_dispatch(af == AF_INET ? NETISR_IP : NETISR_IPV6, m);
1774 } else {
1775 OVPN_COUNTER_ADD(sc, lost_data_pkts_in, 1);
1776 m_freem(m);
1777 }
1778 }
1779
1780 static struct ovpn_kkey *
ovpn_find_key(struct ovpn_softc * sc,struct ovpn_kpeer * peer,const struct ovpn_wire_header * ohdr)1781 ovpn_find_key(struct ovpn_softc *sc, struct ovpn_kpeer *peer,
1782 const struct ovpn_wire_header *ohdr)
1783 {
1784 struct ovpn_kkey *key = NULL;
1785 uint8_t keyid;
1786
1787 OVPN_RASSERT(sc);
1788
1789 keyid = (ntohl(ohdr->opcode) >> 24) & 0x07;
1790
1791 if (peer->keys[0].keyid == keyid)
1792 key = &peer->keys[0];
1793 else if (peer->keys[1].keyid == keyid)
1794 key = &peer->keys[1];
1795
1796 return (key);
1797 }
1798
1799 static int
ovpn_decrypt_rx_cb(struct cryptop * crp)1800 ovpn_decrypt_rx_cb(struct cryptop *crp)
1801 {
1802 struct epoch_tracker et;
1803 struct ovpn_softc *sc = crp->crp_opaque;
1804 struct mbuf *m = crp->crp_buf.cb_mbuf;
1805 struct ovpn_kkey *key;
1806 struct ovpn_kpeer *peer;
1807 struct ovpn_wire_header *ohdr;
1808 uint32_t peerid;
1809
1810 OVPN_RLOCK_TRACKER;
1811
1812 OVPN_RLOCK(sc);
1813
1814 MPASS(crp->crp_buf.cb_type == CRYPTO_BUF_MBUF);
1815
1816 if (crp->crp_etype != 0) {
1817 crypto_freereq(crp);
1818 atomic_add_int(&sc->refcount, -1);
1819 OVPN_COUNTER_ADD(sc, lost_data_pkts_in, 1);
1820 OVPN_RUNLOCK(sc);
1821 m_freem(m);
1822 return (0);
1823 }
1824
1825 CURVNET_SET(sc->ifp->if_vnet);
1826
1827 ohdr = mtodo(m, sizeof(struct udphdr));
1828
1829 peerid = ntohl(ohdr->opcode) & 0x00ffffff;
1830 peer = ovpn_find_peer(sc, peerid);
1831 if (peer == NULL) {
1832 /* No such peer. Drop packet. */
1833 crypto_freereq(crp);
1834 atomic_add_int(&sc->refcount, -1);
1835 OVPN_RUNLOCK(sc);
1836 OVPN_COUNTER_ADD(sc, lost_data_pkts_in, 1);
1837 m_freem(m);
1838 CURVNET_RESTORE();
1839 return (0);
1840 }
1841
1842 key = ovpn_find_key(sc, peer, ohdr);
1843 if (key == NULL) {
1844 crypto_freereq(crp);
1845 atomic_add_int(&sc->refcount, -1);
1846 /*
1847 * Has this key been removed between us starting the decrypt
1848 * and finishing it?
1849 */
1850 OVPN_RUNLOCK(sc);
1851 OVPN_COUNTER_ADD(sc, lost_data_pkts_in, 1);
1852 m_freem(m);
1853 CURVNET_RESTORE();
1854 return (0);
1855 }
1856
1857 /* Now remove the outer headers */
1858 m_adj_decap(m, sizeof(struct udphdr) +
1859 sizeof(struct ovpn_wire_header));
1860
1861 NET_EPOCH_ENTER(et);
1862 ovpn_finish_rx(sc, m, peer, key, ntohl(ohdr->seq), _ovpn_lock_trackerp);
1863 NET_EPOCH_EXIT(et);
1864 OVPN_UNLOCK_ASSERT(sc);
1865
1866 CURVNET_RESTORE();
1867
1868 crypto_freereq(crp);
1869 atomic_add_int(&sc->refcount, -1);
1870
1871 return (0);
1872 }
1873
1874 static int
ovpn_get_af(struct mbuf * m)1875 ovpn_get_af(struct mbuf *m)
1876 {
1877 struct ip *ip;
1878 struct ip6_hdr *ip6;
1879
1880 /*
1881 * We should pullup, but we're only interested in the first byte, so
1882 * that'll always be contiguous.
1883 */
1884 ip = mtod(m, struct ip *);
1885 if (ip->ip_v == IPVERSION)
1886 return (AF_INET);
1887
1888 ip6 = mtod(m, struct ip6_hdr *);
1889 if ((ip6->ip6_vfc & IPV6_VERSION_MASK) == IPV6_VERSION)
1890 return (AF_INET6);
1891
1892 return (0);
1893 }
1894
1895 #ifdef INET
1896 static struct ovpn_kpeer *
ovpn_find_peer_by_ip(struct ovpn_softc * sc,const struct in_addr addr)1897 ovpn_find_peer_by_ip(struct ovpn_softc *sc, const struct in_addr addr)
1898 {
1899 struct ovpn_kpeer *peer = NULL;
1900
1901 OVPN_ASSERT(sc);
1902
1903 /* TODO: Add a second RB so we can look up by IP. */
1904 RB_FOREACH(peer, ovpn_kpeers, &sc->peers) {
1905 if (addr.s_addr == peer->vpn4.s_addr)
1906 return (peer);
1907 }
1908
1909 return (peer);
1910 }
1911 #endif
1912
1913 #ifdef INET6
1914 static struct ovpn_kpeer *
ovpn_find_peer_by_ip6(struct ovpn_softc * sc,const struct in6_addr * addr)1915 ovpn_find_peer_by_ip6(struct ovpn_softc *sc, const struct in6_addr *addr)
1916 {
1917 struct ovpn_kpeer *peer = NULL;
1918
1919 OVPN_ASSERT(sc);
1920
1921 /* TODO: Add a third RB so we can look up by IPv6 address. */
1922 RB_FOREACH(peer, ovpn_kpeers, &sc->peers) {
1923 if (memcmp(addr, &peer->vpn6, sizeof(*addr)) == 0)
1924 return (peer);
1925 }
1926
1927 return (peer);
1928 }
1929 #endif
1930
1931 static struct ovpn_kpeer *
ovpn_route_peer(struct ovpn_softc * sc,struct mbuf ** m0,const struct sockaddr * dst)1932 ovpn_route_peer(struct ovpn_softc *sc, struct mbuf **m0,
1933 const struct sockaddr *dst)
1934 {
1935 struct ovpn_kpeer *peer = NULL;
1936 int af;
1937
1938 NET_EPOCH_ASSERT();
1939 OVPN_ASSERT(sc);
1940
1941 /* Shortcut if we're a client (or are a server and have only one client). */
1942 if (sc->peercount == 1)
1943 return (ovpn_find_only_peer(sc));
1944
1945 if (dst != NULL)
1946 af = dst->sa_family;
1947 else
1948 af = ovpn_get_af(*m0);
1949
1950 switch (af) {
1951 #ifdef INET
1952 case AF_INET: {
1953 const struct sockaddr_in *sa = (const struct sockaddr_in *)dst;
1954 struct nhop_object *nh;
1955 const struct in_addr *ip_dst;
1956
1957 if (sa != NULL) {
1958 ip_dst = &sa->sin_addr;
1959 } else {
1960 struct ip *ip;
1961
1962 *m0 = m_pullup(*m0, sizeof(struct ip));
1963 if (*m0 == NULL)
1964 return (NULL);
1965 ip = mtod(*m0, struct ip *);
1966 ip_dst = &ip->ip_dst;
1967 }
1968
1969 peer = ovpn_find_peer_by_ip(sc, *ip_dst);
1970 SDT_PROBE2(if_ovpn, tx, route, ip4, ip_dst, peer);
1971 if (peer == NULL) {
1972 nh = fib4_lookup(M_GETFIB(*m0), *ip_dst, 0,
1973 NHR_NONE, 0);
1974 if (nh && (nh->nh_flags & NHF_GATEWAY)) {
1975 peer = ovpn_find_peer_by_ip(sc,
1976 nh->gw4_sa.sin_addr);
1977 SDT_PROBE2(if_ovpn, tx, route, ip4,
1978 &nh->gw4_sa.sin_addr, peer);
1979 }
1980 }
1981 break;
1982 }
1983 #endif
1984 #ifdef INET6
1985 case AF_INET6: {
1986 const struct sockaddr_in6 *sa6 =
1987 (const struct sockaddr_in6 *)dst;
1988 struct nhop_object *nh;
1989 const struct in6_addr *ip6_dst;
1990
1991 if (sa6 != NULL) {
1992 ip6_dst = &sa6->sin6_addr;
1993 } else {
1994 struct ip6_hdr *ip6;
1995
1996 *m0 = m_pullup(*m0, sizeof(struct ip6_hdr));
1997 if (*m0 == NULL)
1998 return (NULL);
1999 ip6 = mtod(*m0, struct ip6_hdr *);
2000 ip6_dst = &ip6->ip6_dst;
2001 }
2002
2003 peer = ovpn_find_peer_by_ip6(sc, ip6_dst);
2004 SDT_PROBE2(if_ovpn, tx, route, ip6, ip6_dst, peer);
2005 if (peer == NULL) {
2006 nh = fib6_lookup(M_GETFIB(*m0), ip6_dst, 0,
2007 NHR_NONE, 0);
2008 if (nh && (nh->nh_flags & NHF_GATEWAY)) {
2009 peer = ovpn_find_peer_by_ip6(sc,
2010 &nh->gw6_sa.sin6_addr);
2011 SDT_PROBE2(if_ovpn, tx, route, ip6,
2012 &nh->gw6_sa.sin6_addr, peer);
2013 }
2014 }
2015 break;
2016 }
2017 #endif
2018 }
2019
2020 return (peer);
2021 }
2022
2023 static int
ovpn_transmit(struct ifnet * ifp,struct mbuf * m)2024 ovpn_transmit(struct ifnet *ifp, struct mbuf *m)
2025 {
2026 return (ifp->if_output(ifp, m, NULL, NULL));
2027 }
2028
2029 static int
ovpn_transmit_to_peer(struct ifnet * ifp,struct mbuf * m,struct ovpn_kpeer * peer,struct rm_priotracker * _ovpn_lock_trackerp)2030 ovpn_transmit_to_peer(struct ifnet *ifp, struct mbuf *m,
2031 struct ovpn_kpeer *peer, struct rm_priotracker *_ovpn_lock_trackerp)
2032 {
2033 struct ovpn_wire_header *ohdr;
2034 struct ovpn_kkey *key;
2035 struct ovpn_softc *sc;
2036 struct cryptop *crp;
2037 uint32_t af, seq;
2038 uint64_t seq64;
2039 size_t len, ovpn_hdr_len;
2040 int tunnel_len;
2041 int ret;
2042
2043 sc = ifp->if_softc;
2044
2045 OVPN_RASSERT(sc);
2046
2047 tunnel_len = m->m_pkthdr.len;
2048
2049 key = &peer->keys[OVPN_KEY_SLOT_PRIMARY];
2050 if (key->encrypt == NULL) {
2051 if (_ovpn_lock_trackerp != NULL)
2052 OVPN_RUNLOCK(sc);
2053 m_freem(m);
2054 return (ENOLINK);
2055 }
2056
2057 af = ovpn_get_af(m);
2058 /* Don't capture control packets. */
2059 if (af != 0)
2060 BPF_MTAP2(ifp, &af, sizeof(af), m);
2061
2062 if (__predict_false(if_tunnel_check_nesting(ifp, m, MTAG_OVPN_LOOP, 3))) {
2063 if (_ovpn_lock_trackerp != NULL)
2064 OVPN_RUNLOCK(sc);
2065 OVPN_COUNTER_ADD(sc, lost_data_pkts_out, 1);
2066 m_freem(m);
2067 return (ELOOP);
2068 }
2069
2070 len = m->m_pkthdr.len;
2071 MPASS(len <= ifp->if_mtu);
2072
2073 ovpn_hdr_len = sizeof(struct ovpn_wire_header);
2074 if (key->encrypt->cipher == OVPN_CIPHER_ALG_NONE)
2075 ovpn_hdr_len -= 16; /* No auth tag. */
2076
2077 M_PREPEND(m, ovpn_hdr_len, M_NOWAIT);
2078 if (m == NULL) {
2079 if (_ovpn_lock_trackerp != NULL)
2080 OVPN_RUNLOCK(sc);
2081 OVPN_COUNTER_ADD(sc, nomem_data_pkts_out, 1);
2082 return (ENOBUFS);
2083 }
2084 ohdr = mtod(m, struct ovpn_wire_header *);
2085 ohdr->opcode = (OVPN_OP_DATA_V2 << OVPN_OP_SHIFT) | key->keyid;
2086 ohdr->opcode <<= 24;
2087 ohdr->opcode |= key->peerid;
2088 ohdr->opcode = htonl(ohdr->opcode);
2089
2090 seq64 = atomic_fetchadd_64(&peer->keys[OVPN_KEY_SLOT_PRIMARY].encrypt->tx_seq, 1);
2091 if (seq64 == OVPN_SEQ_ROTATE) {
2092 ovpn_notify_key_rotation(sc, peer);
2093 } else if (seq64 > UINT32_MAX) {
2094 /* We've wrapped, give up on this packet. */
2095 if (_ovpn_lock_trackerp != NULL)
2096 OVPN_RUNLOCK(sc);
2097 OVPN_COUNTER_ADD(sc, nomem_data_pkts_out, 1);
2098
2099 /* Let's avoid (very unlikely, but still) wraparounds of the
2100 * 64-bit counter taking us back to 0. */
2101 atomic_store_64(&peer->keys[OVPN_KEY_SLOT_PRIMARY].encrypt->tx_seq,
2102 UINT32_MAX);
2103
2104 return (ENOBUFS);
2105 }
2106
2107 seq = htonl(seq64 & UINT32_MAX);
2108 ohdr->seq = seq;
2109
2110 OVPN_PEER_COUNTER_ADD(peer, pkt_out, 1);
2111 OVPN_PEER_COUNTER_ADD(peer, bytes_out, len);
2112
2113 if (key->encrypt->cipher == OVPN_CIPHER_ALG_NONE) {
2114 ret = ovpn_encap(sc, peer->peerid, m);
2115 if (_ovpn_lock_trackerp != NULL)
2116 OVPN_RUNLOCK(sc);
2117 if (ret == 0) {
2118 OVPN_COUNTER_ADD(sc, sent_data_pkts, 1);
2119 OVPN_COUNTER_ADD(sc, tunnel_bytes_sent, tunnel_len);
2120 }
2121 return (ret);
2122 }
2123
2124 crp = crypto_getreq(key->encrypt->cryptoid, M_NOWAIT);
2125 if (crp == NULL) {
2126 if (_ovpn_lock_trackerp != NULL)
2127 OVPN_RUNLOCK(sc);
2128 OVPN_COUNTER_ADD(sc, nomem_data_pkts_out, 1);
2129 m_freem(m);
2130 return (ENOBUFS);
2131 }
2132
2133 /* Encryption covers only the payload, not the header. */
2134 crp->crp_payload_start = sizeof(*ohdr);
2135 crp->crp_payload_length = len;
2136 crp->crp_op = CRYPTO_OP_ENCRYPT;
2137
2138 /*
2139 * AAD data covers the ovpn_wire_header minus the auth
2140 * tag.
2141 */
2142 crp->crp_aad_length = sizeof(*ohdr) - sizeof(ohdr->auth_tag);
2143 crp->crp_aad = ohdr;
2144 crp->crp_aad_start = 0;
2145 crp->crp_op |= CRYPTO_OP_COMPUTE_DIGEST;
2146 crp->crp_digest_start = offsetof(struct ovpn_wire_header, auth_tag);
2147
2148 crp->crp_flags |= CRYPTO_F_IV_SEPARATE;
2149 memcpy(crp->crp_iv, &seq, sizeof(seq));
2150 memcpy(crp->crp_iv + sizeof(seq), key->encrypt->nonce,
2151 key->encrypt->noncelen);
2152
2153 crypto_use_mbuf(crp, m);
2154 crp->crp_flags |= CRYPTO_F_CBIFSYNC;
2155 crp->crp_callback = ovpn_encrypt_tx_cb;
2156 crp->crp_opaque = peer;
2157
2158 atomic_add_int(&peer->refcount, 1);
2159 if (_ovpn_lock_trackerp != NULL)
2160 OVPN_RUNLOCK(sc);
2161 if (V_async_crypto)
2162 ret = crypto_dispatch_async(crp, CRYPTO_ASYNC_ORDERED);
2163 else
2164 ret = crypto_dispatch(crp);
2165 if (ret) {
2166 OVPN_COUNTER_ADD(sc, lost_data_pkts_out, 1);
2167 }
2168
2169 return (ret);
2170 }
2171
2172 /*
2173 * Note: Expects to hold the read lock on entry, and will release it itself.
2174 */
2175 static int
ovpn_encap(struct ovpn_softc * sc,uint32_t peerid,struct mbuf * m)2176 ovpn_encap(struct ovpn_softc *sc, uint32_t peerid, struct mbuf *m)
2177 {
2178 struct udphdr *udp;
2179 struct ovpn_kpeer *peer;
2180 int len;
2181
2182 OVPN_RLOCK_TRACKER;
2183
2184 OVPN_RLOCK(sc);
2185 NET_EPOCH_ASSERT();
2186
2187 peer = ovpn_find_peer(sc, peerid);
2188 if (peer == NULL || sc->ifp->if_link_state != LINK_STATE_UP) {
2189 OVPN_RUNLOCK(sc);
2190 OVPN_COUNTER_ADD(sc, lost_data_pkts_out, 1);
2191 m_freem(m);
2192 return (ENETDOWN);
2193 }
2194
2195 len = m->m_pkthdr.len;
2196
2197 M_PREPEND(m, sizeof(struct udphdr), M_NOWAIT);
2198 if (m == NULL) {
2199 OVPN_RUNLOCK(sc);
2200 OVPN_COUNTER_ADD(sc, nomem_data_pkts_out, 1);
2201 m_freem(m);
2202 return (ENOBUFS);
2203 }
2204 udp = mtod(m, struct udphdr *);
2205
2206 MPASS(peer->local.ss_family == peer->remote.ss_family);
2207
2208 udp->uh_sport = ovpn_get_port(&peer->local);
2209 udp->uh_dport = ovpn_get_port(&peer->remote);
2210 udp->uh_ulen = htons(sizeof(struct udphdr) + len);
2211
2212 switch (peer->remote.ss_family) {
2213 #ifdef INET
2214 case AF_INET: {
2215 struct sockaddr_in *in_local = TO_IN(&peer->local);
2216 struct sockaddr_in *in_remote = TO_IN(&peer->remote);
2217 struct ip *ip;
2218
2219 /*
2220 * This requires knowing the source IP, which we don't. Happily
2221 * we're allowed to keep this at 0, and the checksum won't do
2222 * anything the crypto won't already do.
2223 */
2224 udp->uh_sum = 0;
2225
2226 /* Set the checksum flags so we recalculate checksums. */
2227 m->m_pkthdr.csum_flags |= CSUM_IP;
2228 m->m_pkthdr.csum_data = offsetof(struct udphdr, uh_sum);
2229
2230 M_PREPEND(m, sizeof(struct ip), M_NOWAIT);
2231 if (m == NULL) {
2232 OVPN_RUNLOCK(sc);
2233 OVPN_COUNTER_ADD(sc, nomem_data_pkts_out, 1);
2234 return (ENOBUFS);
2235 }
2236 ip = mtod(m, struct ip *);
2237
2238 ip->ip_tos = 0;
2239 ip->ip_len = htons(sizeof(struct ip) + sizeof(struct udphdr) +
2240 len);
2241 ip->ip_off = 0;
2242 ip->ip_ttl = V_ip_defttl;
2243 ip->ip_p = IPPROTO_UDP;
2244 ip->ip_sum = 0;
2245 if (in_local->sin_port != 0)
2246 ip->ip_src = in_local->sin_addr;
2247 else
2248 ip->ip_src.s_addr = INADDR_ANY;
2249 ip->ip_dst = in_remote->sin_addr;
2250
2251 OVPN_RUNLOCK(sc);
2252 OVPN_COUNTER_ADD(sc, transport_bytes_sent, m->m_pkthdr.len);
2253
2254 return (ip_output(m, NULL, NULL, 0, NULL, NULL));
2255 }
2256 #endif
2257 #ifdef INET6
2258 case AF_INET6: {
2259 struct sockaddr_in6 *in6_local = TO_IN6(&peer->local);
2260 struct sockaddr_in6 *in6_remote = TO_IN6(&peer->remote);
2261 struct ip6_hdr *ip6;
2262
2263 M_PREPEND(m, sizeof(struct ip6_hdr), M_NOWAIT);
2264 if (m == NULL) {
2265 OVPN_RUNLOCK(sc);
2266 OVPN_COUNTER_ADD(sc, nomem_data_pkts_out, 1);
2267 return (ENOBUFS);
2268 }
2269 m = m_pullup(m, sizeof(*ip6) + sizeof(*udp));
2270 if (m == NULL) {
2271 OVPN_RUNLOCK(sc);
2272 OVPN_COUNTER_ADD(sc, nomem_data_pkts_out, 1);
2273 return (ENOBUFS);
2274 }
2275
2276 ip6 = mtod(m, struct ip6_hdr *);
2277
2278 ip6->ip6_vfc = IPV6_VERSION;
2279 ip6->ip6_flow &= ~IPV6_FLOWINFO_MASK;
2280 ip6->ip6_plen = htons(sizeof(*ip6) + sizeof(struct udphdr) +
2281 len);
2282 ip6->ip6_nxt = IPPROTO_UDP;
2283 ip6->ip6_hlim = V_ip6_defhlim;
2284
2285 memcpy(&ip6->ip6_src, &in6_local->sin6_addr,
2286 sizeof(ip6->ip6_src));
2287 memcpy(&ip6->ip6_dst, &in6_remote->sin6_addr,
2288 sizeof(ip6->ip6_dst));
2289
2290 if (IN6_IS_ADDR_LINKLOCAL(&ip6->ip6_src)) {
2291 /* Local and remote must have the same scope. */
2292 ip6->ip6_src.__u6_addr.__u6_addr16[1] =
2293 htons(in6_remote->sin6_scope_id & 0xffff);
2294 }
2295 if (IN6_IS_ADDR_LINKLOCAL(&ip6->ip6_dst))
2296 ip6->ip6_dst.__u6_addr.__u6_addr16[1] =
2297 htons(in6_remote->sin6_scope_id & 0xffff);
2298
2299 udp = mtodo(m, sizeof(*ip6));
2300 udp->uh_sum = in6_cksum_pseudo(ip6,
2301 m->m_pkthdr.len - sizeof(struct ip6_hdr),
2302 IPPROTO_UDP, 0);
2303
2304 m->m_pkthdr.csum_flags |= CSUM_UDP_IPV6;
2305 m->m_pkthdr.csum_data = offsetof(struct udphdr, uh_sum);
2306
2307 OVPN_RUNLOCK(sc);
2308 OVPN_COUNTER_ADD(sc, transport_bytes_sent, m->m_pkthdr.len);
2309
2310 return (ip6_output(m, NULL, NULL, IPV6_UNSPECSRC, NULL, NULL,
2311 NULL));
2312 }
2313 #endif
2314 default:
2315 panic("Unsupported address family %d",
2316 peer->remote.ss_family);
2317 }
2318 }
2319
2320 static int
ovpn_output(struct ifnet * ifp,struct mbuf * m,const struct sockaddr * dst,struct route * ro)2321 ovpn_output(struct ifnet *ifp, struct mbuf *m, const struct sockaddr *dst,
2322 struct route *ro)
2323 {
2324 struct ovpn_softc *sc;
2325 struct ovpn_kpeer *peer;
2326
2327 OVPN_RLOCK_TRACKER;
2328
2329 sc = ifp->if_softc;
2330
2331 m = m_unshare(m, M_NOWAIT);
2332 if (m == NULL) {
2333 OVPN_COUNTER_ADD(sc, lost_data_pkts_out, 1);
2334 return (ENOBUFS);
2335 }
2336
2337 OVPN_RLOCK(sc);
2338
2339 SDT_PROBE1(if_ovpn, tx, transmit, start, m);
2340
2341 if (__predict_false(ifp->if_link_state != LINK_STATE_UP)) {
2342 OVPN_COUNTER_ADD(sc, lost_data_pkts_out, 1);
2343 OVPN_RUNLOCK(sc);
2344 m_freem(m);
2345 return (ENETDOWN);
2346 }
2347
2348 /**
2349 * Only obey 'dst' (i.e. the gateway) if no route is supplied.
2350 * That's our indication that we're being called through pf's route-to,
2351 * and we should route according to 'dst' instead. We can't do so
2352 * consistently, because the usual openvpn configuration sets the first
2353 * non-server IP in the subnet as the gateway. If we always use that
2354 * one we'd end up routing all traffic to the first client.
2355 * tl;dr: 'ro == NULL' tells us pf is doing a route-to, and then but
2356 * only then, we should treat 'dst' as the destination. */
2357 peer = ovpn_route_peer(sc, &m, ro == NULL ? dst : NULL);
2358 if (peer == NULL) {
2359 /* No destination. */
2360 OVPN_COUNTER_ADD(sc, lost_data_pkts_out, 1);
2361 OVPN_RUNLOCK(sc);
2362 m_freem(m);
2363 return (ENETDOWN);
2364 }
2365
2366 return (ovpn_transmit_to_peer(ifp, m, peer, _ovpn_lock_trackerp));
2367 }
2368
2369 static bool
ovpn_check_replay(struct ovpn_kkey_dir * key,uint32_t seq)2370 ovpn_check_replay(struct ovpn_kkey_dir *key, uint32_t seq)
2371 {
2372 uint32_t d;
2373
2374 mtx_lock(&key->replay_mtx);
2375
2376 /* Sequence number must be strictly greater than rx_seq */
2377 if (seq <= key->rx_seq) {
2378 mtx_unlock(&key->replay_mtx);
2379 return (false);
2380 }
2381
2382 /* Large jump. The packet authenticated okay, so just accept that. */
2383 if (seq > (key->rx_seq + (sizeof(key->rx_window) * 8))) {
2384 key->rx_seq = seq;
2385 key->rx_window = 0;
2386 mtx_unlock(&key->replay_mtx);
2387 return (true);
2388 }
2389
2390 /* Happy case. */
2391 if ((seq == key->rx_seq + 1) && key->rx_window == 0) {
2392 key->rx_seq++;
2393 mtx_unlock(&key->replay_mtx);
2394 return (true);
2395 }
2396
2397 d = seq - key->rx_seq - 1;
2398
2399 if (key->rx_window & ((uint64_t)1 << d)) {
2400 /* Dupe! */
2401 mtx_unlock(&key->replay_mtx);
2402 return (false);
2403 }
2404
2405 key->rx_window |= (uint64_t)1 << d;
2406
2407 while (key->rx_window & 1) {
2408 key->rx_seq++;
2409 key->rx_window >>= 1;
2410 }
2411
2412 mtx_unlock(&key->replay_mtx);
2413
2414 return (true);
2415 }
2416
2417 static struct ovpn_kpeer *
ovpn_peer_from_mbuf(struct ovpn_softc * sc,struct mbuf * m,int off)2418 ovpn_peer_from_mbuf(struct ovpn_softc *sc, struct mbuf *m, int off)
2419 {
2420 struct ovpn_wire_header ohdr;
2421 uint32_t peerid;
2422 const size_t hdrlen = sizeof(ohdr) - sizeof(ohdr.auth_tag);
2423
2424 OVPN_RASSERT(sc);
2425
2426 if (m_length(m, NULL) < (off + sizeof(struct udphdr) + hdrlen))
2427 return (NULL);
2428
2429 m_copydata(m, off + sizeof(struct udphdr), hdrlen, (caddr_t)&ohdr);
2430
2431 peerid = ntohl(ohdr.opcode) & 0x00ffffff;
2432
2433 return (ovpn_find_peer(sc, peerid));
2434 }
2435
2436 static bool
ovpn_udp_input(struct mbuf * m,int off,struct inpcb * inp,const struct sockaddr * sa,void * ctx)2437 ovpn_udp_input(struct mbuf *m, int off, struct inpcb *inp,
2438 const struct sockaddr *sa, void *ctx)
2439 {
2440 struct ovpn_softc *sc = ctx;
2441 struct ovpn_wire_header tmphdr;
2442 struct ovpn_wire_header *ohdr;
2443 struct udphdr *uhdr;
2444 struct ovpn_kkey *key;
2445 struct cryptop *crp;
2446 struct ovpn_kpeer *peer;
2447 size_t ohdrlen;
2448 int ret;
2449 uint8_t op;
2450
2451 OVPN_RLOCK_TRACKER;
2452
2453 M_ASSERTPKTHDR(m);
2454
2455 OVPN_COUNTER_ADD(sc, transport_bytes_received, m->m_pkthdr.len - off);
2456
2457 ohdrlen = sizeof(*ohdr) - sizeof(ohdr->auth_tag);
2458
2459 OVPN_RLOCK(sc);
2460
2461 peer = ovpn_peer_from_mbuf(sc, m, off);
2462 if (peer == NULL) {
2463 OVPN_RUNLOCK(sc);
2464 return (false);
2465 }
2466
2467 if (m_length(m, NULL) < (off + sizeof(*uhdr) + ohdrlen)) {
2468 /* Short packet. */
2469 OVPN_RUNLOCK(sc);
2470 return (false);
2471 }
2472
2473 m_copydata(m, off + sizeof(*uhdr), ohdrlen, (caddr_t)&tmphdr);
2474
2475 op = ntohl(tmphdr.opcode) >> 24 >> OVPN_OP_SHIFT;
2476 if (op != OVPN_OP_DATA_V2) {
2477 /* Control packet? */
2478 OVPN_RUNLOCK(sc);
2479 return (false);
2480 }
2481
2482 m = m_unshare(m, M_NOWAIT);
2483 if (m == NULL) {
2484 OVPN_COUNTER_ADD(sc, nomem_data_pkts_in, 1);
2485 return (true);
2486 }
2487
2488 m = m_pullup(m, off + sizeof(*uhdr) + ohdrlen);
2489 if (m == NULL) {
2490 OVPN_RUNLOCK(sc);
2491 OVPN_COUNTER_ADD(sc, nomem_data_pkts_in, 1);
2492 return (true);
2493 }
2494
2495 /*
2496 * Simplify things by getting rid of the preceding headers, we don't
2497 * care about them.
2498 */
2499 m_adj_decap(m, off);
2500
2501 uhdr = mtodo(m, 0);
2502 ohdr = mtodo(m, sizeof(*uhdr));
2503
2504 key = ovpn_find_key(sc, peer, ohdr);
2505 if (key == NULL || key->decrypt == NULL) {
2506 OVPN_RUNLOCK(sc);
2507 OVPN_COUNTER_ADD(sc, lost_data_pkts_in, 1);
2508 m_freem(m);
2509 return (true);
2510 }
2511
2512 /*
2513 * If we got this from a different address than we expected tag the packet.
2514 * We'll deal with notifiying userspace later, after we've decrypted and
2515 * verified.
2516 */
2517 if (! ovpn_sockaddr_compare((struct sockaddr *)&peer->remote, sa)) {
2518 struct m_tag *mt;
2519 struct ovpn_mtag *ot;
2520
2521 MPASS(sa->sa_len <= sizeof(ot->addr));
2522 mt = m_tag_get(PACKET_TAG_OVPN, sizeof(*ot), M_NOWAIT);
2523 /*
2524 * If we fail to allocate here we'll just try again on the next
2525 * packet.
2526 */
2527 if (mt != NULL) {
2528 ot = (struct ovpn_mtag *)(mt + 1);
2529 memcpy(&ot->addr, sa, sa->sa_len);
2530
2531 m_tag_prepend(m, mt);
2532 }
2533 }
2534
2535 if (key->decrypt->cipher == OVPN_CIPHER_ALG_NONE) {
2536 /* Now remove the outer headers */
2537 m_adj_decap(m, sizeof(struct udphdr) + ohdrlen);
2538
2539 ohdr = mtodo(m, sizeof(*uhdr));
2540
2541 ovpn_finish_rx(sc, m, peer, key, ntohl(ohdr->seq),
2542 _ovpn_lock_trackerp);
2543 OVPN_UNLOCK_ASSERT(sc);
2544 return (true);
2545 }
2546
2547 ohdrlen += sizeof(ohdr->auth_tag);
2548
2549 m = m_pullup(m, sizeof(*uhdr) + ohdrlen);
2550 if (m == NULL) {
2551 OVPN_RUNLOCK(sc);
2552 OVPN_COUNTER_ADD(sc, nomem_data_pkts_in, 1);
2553 return (true);
2554 }
2555 uhdr = mtodo(m, 0);
2556 ohdr = mtodo(m, sizeof(*uhdr));
2557
2558 /* Decrypt */
2559 crp = crypto_getreq(key->decrypt->cryptoid, M_NOWAIT);
2560 if (crp == NULL) {
2561 OVPN_COUNTER_ADD(sc, nomem_data_pkts_in, 1);
2562 OVPN_RUNLOCK(sc);
2563 m_freem(m);
2564 return (true);
2565 }
2566
2567 crp->crp_payload_start = sizeof(struct udphdr) + sizeof(*ohdr);
2568 crp->crp_payload_length = ntohs(uhdr->uh_ulen) -
2569 sizeof(*uhdr) - sizeof(*ohdr);
2570 crp->crp_op = CRYPTO_OP_DECRYPT;
2571
2572 /* AAD validation. */
2573 crp->crp_aad_length = sizeof(*ohdr) - sizeof(ohdr->auth_tag);
2574 crp->crp_aad = ohdr;
2575 crp->crp_aad_start = 0;
2576 crp->crp_op |= CRYPTO_OP_VERIFY_DIGEST;
2577 crp->crp_digest_start = sizeof(struct udphdr) +
2578 offsetof(struct ovpn_wire_header, auth_tag);
2579
2580 crp->crp_flags |= CRYPTO_F_IV_SEPARATE;
2581 memcpy(crp->crp_iv, &ohdr->seq, sizeof(ohdr->seq));
2582 memcpy(crp->crp_iv + sizeof(ohdr->seq), key->decrypt->nonce,
2583 key->decrypt->noncelen);
2584
2585 crypto_use_mbuf(crp, m);
2586 crp->crp_flags |= CRYPTO_F_CBIFSYNC;
2587 crp->crp_callback = ovpn_decrypt_rx_cb;
2588 crp->crp_opaque = sc;
2589
2590 atomic_add_int(&sc->refcount, 1);
2591 OVPN_RUNLOCK(sc);
2592 if (V_async_crypto)
2593 ret = crypto_dispatch_async(crp, CRYPTO_ASYNC_ORDERED);
2594 else
2595 ret = crypto_dispatch(crp);
2596 if (ret != 0) {
2597 OVPN_COUNTER_ADD(sc, lost_data_pkts_in, 1);
2598 }
2599
2600 return (true);
2601 }
2602
2603 static void
ovpn_qflush(struct ifnet * ifp __unused)2604 ovpn_qflush(struct ifnet *ifp __unused)
2605 {
2606
2607 }
2608
2609 static void
ovpn_flush_rxring(struct ovpn_softc * sc)2610 ovpn_flush_rxring(struct ovpn_softc *sc)
2611 {
2612 struct ovpn_notification *n;
2613
2614 OVPN_WASSERT(sc);
2615
2616 while (! buf_ring_empty(sc->notifring)) {
2617 n = buf_ring_dequeue_sc(sc->notifring);
2618 free(n, M_OVPN);
2619 }
2620 }
2621
2622 #ifdef VIMAGE
2623 static void
ovpn_reassign(struct ifnet * ifp,struct vnet * new_vnet __unused,char * unused __unused)2624 ovpn_reassign(struct ifnet *ifp, struct vnet *new_vnet __unused,
2625 char *unused __unused)
2626 {
2627 struct ovpn_softc *sc = ifp->if_softc;
2628 struct ovpn_kpeer *peer, *tmppeer;
2629 int ret __diagused;
2630
2631 OVPN_WLOCK(sc);
2632
2633 /* Flush keys & configuration. */
2634 RB_FOREACH_SAFE(peer, ovpn_kpeers, &sc->peers, tmppeer) {
2635 peer->del_reason = OVPN_DEL_REASON_REQUESTED;
2636 ret = _ovpn_del_peer(sc, peer);
2637 MPASS(ret == 0);
2638 }
2639
2640 ovpn_flush_rxring(sc);
2641
2642 OVPN_WUNLOCK(sc);
2643 }
2644 #endif
2645
2646 static int
ovpn_clone_match(struct if_clone * ifc,const char * name)2647 ovpn_clone_match(struct if_clone *ifc, const char *name)
2648 {
2649 /*
2650 * Allow all names that start with 'ovpn', specifically because pfSense
2651 * uses ovpnc1 / ovpns2
2652 */
2653 return (strncmp(ovpnname, name, strlen(ovpnname)) == 0);
2654 }
2655
2656 static int
ovpn_clone_create(struct if_clone * ifc,char * name,size_t len,struct ifc_data * ifd,struct ifnet ** ifpp)2657 ovpn_clone_create(struct if_clone *ifc, char *name, size_t len,
2658 struct ifc_data *ifd, struct ifnet **ifpp)
2659 {
2660 struct ovpn_softc *sc;
2661 struct ifnet *ifp;
2662 char *dp;
2663 int error, unit, wildcard;
2664
2665 /* Try to see if a special unit was requested. */
2666 error = ifc_name2unit(name, &unit);
2667 if (error != 0)
2668 return (error);
2669 wildcard = (unit < 0);
2670
2671 error = ifc_alloc_unit(ifc, &unit);
2672 if (error != 0)
2673 return (error);
2674
2675 /*
2676 * If no unit had been given, we need to adjust the ifName.
2677 */
2678 for (dp = name; *dp != '\0'; dp++);
2679 if (wildcard) {
2680 error = snprintf(dp, len - (dp - name), "%d", unit);
2681 if (error > len - (dp - name)) {
2682 /* ifName too long. */
2683 ifc_free_unit(ifc, unit);
2684 return (ENOSPC);
2685 }
2686 dp += error;
2687 }
2688
2689 /* Make sure it doesn't already exist. */
2690 if (ifunit(name) != NULL)
2691 return (EEXIST);
2692
2693 sc = malloc(sizeof(struct ovpn_softc), M_OVPN, M_WAITOK | M_ZERO);
2694 sc->ifp = if_alloc(IFT_ENC);
2695 rm_init_flags(&sc->lock, "if_ovpn_lock", RM_RECURSE);
2696 sc->refcount = 0;
2697
2698 sc->notifring = buf_ring_alloc(32, M_OVPN, M_WAITOK, NULL);
2699
2700 COUNTER_ARRAY_ALLOC(sc->counters, OVPN_COUNTER_SIZE, M_WAITOK);
2701
2702 ifp = sc->ifp;
2703 ifp->if_softc = sc;
2704 strlcpy(ifp->if_xname, name, IFNAMSIZ);
2705 ifp->if_dname = ovpngroupname;
2706 ifp->if_dunit = unit;
2707
2708 ifp->if_addrlen = 0;
2709 ifp->if_mtu = 1428;
2710 ifp->if_flags = IFF_POINTOPOINT | IFF_MULTICAST;
2711 ifp->if_ioctl = ovpn_ioctl;
2712 ifp->if_transmit = ovpn_transmit;
2713 ifp->if_output = ovpn_output;
2714 ifp->if_qflush = ovpn_qflush;
2715 #ifdef VIMAGE
2716 ifp->if_reassign = ovpn_reassign;
2717 #endif
2718 ifp->if_capabilities |= IFCAP_LINKSTATE;
2719 ifp->if_capenable |= IFCAP_LINKSTATE;
2720
2721 if_attach(ifp);
2722 bpfattach(ifp, DLT_NULL, sizeof(uint32_t));
2723 *ifpp = ifp;
2724
2725 return (0);
2726 }
2727
2728 static void
ovpn_clone_destroy_cb(struct epoch_context * ctx)2729 ovpn_clone_destroy_cb(struct epoch_context *ctx)
2730 {
2731 struct ovpn_softc *sc;
2732 int ret __diagused;
2733
2734 sc = __containerof(ctx, struct ovpn_softc, epoch_ctx);
2735
2736 MPASS(sc->peercount == 0);
2737 MPASS(RB_EMPTY(&sc->peers));
2738
2739 if (sc->so != NULL) {
2740 CURVNET_SET(sc->ifp->if_vnet);
2741 ret = udp_set_kernel_tunneling(sc->so, NULL, NULL, NULL);
2742 MPASS(ret == 0);
2743 sorele(sc->so);
2744 CURVNET_RESTORE();
2745 }
2746
2747 COUNTER_ARRAY_FREE(sc->counters, OVPN_COUNTER_SIZE);
2748
2749 rm_destroy(&sc->lock);
2750 if_free(sc->ifp);
2751 free(sc, M_OVPN);
2752 }
2753
2754 static int
ovpn_clone_destroy(struct if_clone * ifc,struct ifnet * ifp,uint32_t flags)2755 ovpn_clone_destroy(struct if_clone *ifc, struct ifnet *ifp, uint32_t flags)
2756 {
2757 struct ovpn_softc *sc;
2758 struct ovpn_kpeer *peer, *tmppeer;
2759 int unit;
2760 int ret __diagused;
2761
2762 sc = ifp->if_softc;
2763 unit = ifp->if_dunit;
2764
2765 OVPN_WLOCK(sc);
2766
2767 if (atomic_load_int(&sc->refcount) > 0) {
2768 OVPN_WUNLOCK(sc);
2769 return (EBUSY);
2770 }
2771
2772 RB_FOREACH_SAFE(peer, ovpn_kpeers, &sc->peers, tmppeer) {
2773 peer->del_reason = OVPN_DEL_REASON_REQUESTED;
2774 ret = _ovpn_del_peer(sc, peer);
2775 MPASS(ret == 0);
2776 }
2777
2778 ovpn_flush_rxring(sc);
2779 buf_ring_free(sc->notifring, M_OVPN);
2780
2781 OVPN_WUNLOCK(sc);
2782
2783 bpfdetach(ifp);
2784 if_detach(ifp);
2785 ifp->if_softc = NULL;
2786
2787 NET_EPOCH_CALL(ovpn_clone_destroy_cb, &sc->epoch_ctx);
2788
2789 if (unit != IF_DUNIT_NONE)
2790 ifc_free_unit(ifc, unit);
2791
2792 NET_EPOCH_DRAIN_CALLBACKS();
2793
2794 return (0);
2795 }
2796
2797 static void
vnet_ovpn_init(const void * unused __unused)2798 vnet_ovpn_init(const void *unused __unused)
2799 {
2800 struct if_clone_addreq req = {
2801 .match_f = ovpn_clone_match,
2802 .create_f = ovpn_clone_create,
2803 .destroy_f = ovpn_clone_destroy,
2804 };
2805 V_ovpn_cloner = ifc_attach_cloner(ovpngroupname, &req);
2806 }
2807 VNET_SYSINIT(vnet_ovpn_init, SI_SUB_PSEUDO, SI_ORDER_ANY,
2808 vnet_ovpn_init, NULL);
2809
2810 static int
ovpn_prison_remove(void * obj,void * data __unused)2811 ovpn_prison_remove(void *obj, void *data __unused)
2812 {
2813 #ifdef VIMAGE
2814 struct prison *pr;
2815
2816 pr = obj;
2817 if (prison_owns_vnet(pr)) {
2818 CURVNET_SET(pr->pr_vnet);
2819 if (V_ovpn_cloner != NULL) {
2820 ifc_detach_cloner(V_ovpn_cloner);
2821 V_ovpn_cloner = NULL;
2822 }
2823 CURVNET_RESTORE();
2824 }
2825 #endif
2826 return (0);
2827 }
2828
2829 static int
ovpnmodevent(module_t mod,int type,void * data)2830 ovpnmodevent(module_t mod, int type, void *data)
2831 {
2832 static int ovpn_osd_jail_slot;
2833
2834 switch (type) {
2835 case MOD_LOAD: {
2836 /*
2837 * Registration is handled in vnet_ovpn_init(), but cloned
2838 * interfaces must be destroyed via PR_METHOD_REMOVE since they
2839 * hold a reference to the prison via the UDP socket, which
2840 * prevents the prison from being destroyed.
2841 */
2842 osd_method_t methods[PR_MAXMETHOD] = {
2843 [PR_METHOD_REMOVE] = ovpn_prison_remove,
2844 };
2845 ovpn_osd_jail_slot = osd_jail_register(NULL, methods);
2846 break;
2847 }
2848 case MOD_UNLOAD:
2849 if (ovpn_osd_jail_slot != 0)
2850 osd_jail_deregister(ovpn_osd_jail_slot);
2851 CURVNET_SET(vnet0);
2852 if (V_ovpn_cloner != NULL) {
2853 ifc_detach_cloner(V_ovpn_cloner);
2854 V_ovpn_cloner = NULL;
2855 }
2856 CURVNET_RESTORE();
2857 break;
2858 default:
2859 return (EOPNOTSUPP);
2860 }
2861
2862 return (0);
2863 }
2864
2865 static moduledata_t ovpn_mod = {
2866 "if_ovpn",
2867 ovpnmodevent,
2868 0
2869 };
2870
2871 DECLARE_MODULE(if_ovpn, ovpn_mod, SI_SUB_PSEUDO, SI_ORDER_ANY);
2872 MODULE_VERSION(if_ovpn, 1);
2873 MODULE_DEPEND(if_ovpn, crypto, 1, 1, 1);
2874