1 /*- 2 * SPDX-License-Identifier: BSD-2-Clause-FreeBSD 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/netisr.h> 61 #include <net/route/nhop.h> 62 63 #include <netinet/in.h> 64 #include <netinet/in_fib.h> 65 #include <netinet/ip.h> 66 #include <netinet/ip6.h> 67 #include <netinet/ip_var.h> 68 #include <netinet/udp.h> 69 #include <netinet/udp_var.h> 70 71 #include <netinet6/ip6_var.h> 72 #include <netinet6/in6_fib.h> 73 74 #include <machine/in_cksum.h> 75 76 #include <opencrypto/cryptodev.h> 77 78 #include "if_ovpn.h" 79 80 struct ovpn_kkey_dir { 81 int refcount; 82 uint8_t key[32]; 83 uint8_t keylen; 84 uint8_t nonce[8]; 85 uint8_t noncelen; 86 enum ovpn_key_cipher cipher; 87 crypto_session_t cryptoid; 88 89 struct mtx replay_mtx; 90 /* 91 * Last seen gapless sequence number. New rx seq numbers must be 92 * strictly higher than this. 93 */ 94 uint32_t rx_seq; 95 /* Seen packets, relative to rx_seq. bit(0) will always be 0. */ 96 uint64_t rx_window; 97 }; 98 99 struct ovpn_kkey { 100 struct ovpn_kkey_dir *encrypt; 101 struct ovpn_kkey_dir *decrypt; 102 uint8_t keyid; 103 uint32_t peerid; 104 }; 105 106 struct ovpn_keepalive { 107 uint32_t interval; 108 uint32_t timeout; 109 }; 110 111 struct ovpn_wire_header { 112 uint32_t opcode; /* opcode, key id, peer id */ 113 uint32_t seq; 114 uint8_t auth_tag[16]; 115 }; 116 117 struct ovpn_notification { 118 enum ovpn_notif_type type; 119 uint32_t peerid; 120 }; 121 122 struct ovpn_softc; 123 124 struct ovpn_kpeer { 125 int refcount; 126 uint32_t peerid; 127 128 struct ovpn_softc *sc; 129 struct sockaddr_storage local; 130 struct sockaddr_storage remote; 131 132 struct in_addr vpn4; 133 struct in6_addr vpn6; 134 135 struct ovpn_kkey keys[2]; 136 uint32_t tx_seq; 137 138 struct ovpn_keepalive keepalive; 139 uint32_t *last_active; 140 struct callout ping_send; 141 struct callout ping_rcv; 142 }; 143 144 #define OVPN_MAX_PEERS 128 145 146 struct ovpn_counters { 147 uint64_t lost_ctrl_pkts_in; 148 uint64_t lost_ctrl_pkts_out; 149 uint64_t lost_data_pkts_in; 150 uint64_t lost_data_pkts_out; 151 uint64_t nomem_data_pkts_in; 152 uint64_t nomem_data_pkts_out; 153 uint64_t received_ctrl_pkts; 154 uint64_t received_data_pkts; 155 uint64_t sent_ctrl_pkts; 156 uint64_t sent_data_pkts; 157 158 uint64_t transport_bytes_sent; 159 uint64_t transport_bytes_received; 160 uint64_t tunnel_bytes_sent; 161 uint64_t tunnel_bytes_received; 162 }; 163 #define OVPN_COUNTER_SIZE (sizeof(struct ovpn_counters)/sizeof(uint64_t)) 164 165 struct ovpn_softc { 166 int refcount; 167 struct rmlock lock; 168 struct ifnet *ifp; 169 struct socket *so; 170 int peercount; 171 struct ovpn_kpeer *peers[OVPN_MAX_PEERS]; /* XXX Hard limit for now? */ 172 173 /* Pending packets */ 174 struct buf_ring *rxring; 175 struct buf_ring *notifring; 176 177 counter_u64_t counters[OVPN_COUNTER_SIZE]; 178 179 struct epoch_context epoch_ctx; 180 }; 181 182 static struct ovpn_kpeer *ovpn_find_peer(struct ovpn_softc *, uint32_t); 183 static bool ovpn_udp_input(struct mbuf *, int, struct inpcb *, 184 const struct sockaddr *, void *); 185 static int ovpn_transmit_to_peer(struct ifnet *, struct mbuf *, 186 struct ovpn_kpeer *, struct rm_priotracker *); 187 static int ovpn_encap(struct ovpn_softc *, uint32_t, struct mbuf *); 188 static int ovpn_get_af(struct mbuf *); 189 static void ovpn_free_kkey_dir(struct ovpn_kkey_dir *); 190 static bool ovpn_check_replay(struct ovpn_kkey_dir *, uint32_t); 191 192 #define OVPN_MTU_MIN 576 193 #define OVPN_MTU_MAX (IP_MAXPACKET - sizeof(struct ip) - \ 194 sizeof(struct udphdr) - sizeof(struct ovpn_wire_header)) 195 196 #define OVPN_OP_DATA_V2 0x09 197 #define OVPN_OP_SHIFT 3 198 199 VNET_DEFINE_STATIC(struct if_clone *, ovpn_cloner); 200 #define V_ovpn_cloner VNET(ovpn_cloner) 201 202 #define OVPN_RLOCK_TRACKER struct rm_priotracker _ovpn_lock_tracker; \ 203 struct rm_priotracker *_ovpn_lock_trackerp = &_ovpn_lock_tracker 204 #define OVPN_RLOCK(sc) rm_rlock(&(sc)->lock, _ovpn_lock_trackerp) 205 #define OVPN_RUNLOCK(sc) rm_runlock(&(sc)->lock, _ovpn_lock_trackerp) 206 #define OVPN_WLOCK(sc) rm_wlock(&(sc)->lock) 207 #define OVPN_WUNLOCK(sc) rm_wunlock(&(sc)->lock) 208 #define OVPN_ASSERT(sc) rm_assert(&(sc)->lock, RA_LOCKED) 209 #define OVPN_RASSERT(sc) rm_assert(&(sc)->lock, RA_RLOCKED) 210 #define OVPN_WASSERT(sc) rm_assert(&(sc)->lock, RA_WLOCKED) 211 #define OVPN_UNLOCK_ASSERT(sc) rm_assert(&(sc)->lock, RA_UNLOCKED) 212 213 #define OVPN_COUNTER_ADD(sc, name, val) \ 214 counter_u64_add(sc->counters[offsetof(struct ovpn_counters, name) / \ 215 sizeof(uint64_t)], val) 216 217 #define TO_IN(x) ((struct sockaddr_in *)(x)) 218 #define TO_IN6(x) ((struct sockaddr_in6 *)(x)) 219 220 SDT_PROVIDER_DEFINE(if_ovpn); 221 SDT_PROBE_DEFINE1(if_ovpn, tx, transmit, start, "struct mbuf *"); 222 SDT_PROBE_DEFINE2(if_ovpn, tx, route, ip4, "struct in_addr *", "struct ovpn_kpeer *"); 223 SDT_PROBE_DEFINE2(if_ovpn, tx, route, ip6, "struct in6_addr *", "struct ovpn_kpeer *"); 224 225 static const char ovpnname[] = "ovpn"; 226 static const char ovpngroupname[] = "openvpn"; 227 228 static MALLOC_DEFINE(M_OVPN, ovpnname, "OpenVPN DCO Interface"); 229 230 SYSCTL_DECL(_net_link); 231 static SYSCTL_NODE(_net_link, IFT_OTHER, openvpn, CTLFLAG_RW | CTLFLAG_MPSAFE, 0, 232 "OpenVPN DCO Interface"); 233 VNET_DEFINE_STATIC(int, replay_protection) = 0; 234 #define V_replay_protection VNET(replay_protection) 235 SYSCTL_INT(_net_link_openvpn, OID_AUTO, replay_protection, CTLFLAG_VNET | CTLFLAG_RW, 236 &VNET_NAME(replay_protection), 0, "Validate sequence numbers"); 237 238 static struct ovpn_kpeer * 239 ovpn_find_peer(struct ovpn_softc *sc, uint32_t peerid) 240 { 241 struct ovpn_kpeer *p = NULL; 242 243 OVPN_ASSERT(sc); 244 245 for (int i = 0; i < OVPN_MAX_PEERS; i++) { 246 p = sc->peers[i]; 247 if (p == NULL) 248 continue; 249 250 if (p->peerid == peerid) { 251 MPASS(p->sc == sc); 252 break; 253 } 254 } 255 256 return (p); 257 } 258 259 static struct ovpn_kpeer * 260 ovpn_find_only_peer(struct ovpn_softc *sc) 261 { 262 OVPN_ASSERT(sc); 263 264 for (int i = 0; i < OVPN_MAX_PEERS; i++) { 265 if (sc->peers[i] == NULL) 266 continue; 267 return (sc->peers[i]); 268 } 269 270 MPASS(false); 271 272 return (NULL); 273 } 274 275 static uint16_t 276 ovpn_get_port(struct sockaddr_storage *s) 277 { 278 switch (s->ss_family) { 279 case AF_INET: { 280 struct sockaddr_in *in = (struct sockaddr_in *)s; 281 return (in->sin_port); 282 } 283 case AF_INET6: { 284 struct sockaddr_in6 *in6 = (struct sockaddr_in6 *)s; 285 return (in6->sin6_port); 286 } 287 default: 288 panic("Unsupported address family %d", s->ss_family); 289 } 290 } 291 292 static int 293 ovpn_nvlist_to_sockaddr(const nvlist_t *nvl, struct sockaddr_storage *sa) 294 { 295 int af; 296 297 if (! nvlist_exists_number(nvl, "af")) 298 return (EINVAL); 299 if (! nvlist_exists_binary(nvl, "address")) 300 return (EINVAL); 301 if (! nvlist_exists_number(nvl, "port")) 302 return (EINVAL); 303 304 af = nvlist_get_number(nvl, "af"); 305 306 switch (af) { 307 #ifdef INET 308 case AF_INET: { 309 struct sockaddr_in *in = (struct sockaddr_in *)sa; 310 size_t len; 311 const void *addr = nvlist_get_binary(nvl, "address", &len); 312 in->sin_family = af; 313 if (len != sizeof(in->sin_addr)) 314 return (EINVAL); 315 316 memcpy(&in->sin_addr, addr, sizeof(in->sin_addr)); 317 in->sin_port = nvlist_get_number(nvl, "port"); 318 break; 319 } 320 #endif 321 #ifdef INET6 322 case AF_INET6: { 323 struct sockaddr_in6 *in6 = (struct sockaddr_in6 *)sa; 324 size_t len; 325 const void *addr = nvlist_get_binary(nvl, "address", &len); 326 in6->sin6_family = af; 327 if (len != sizeof(in6->sin6_addr)) 328 return (EINVAL); 329 330 memcpy(&in6->sin6_addr, addr, sizeof(in6->sin6_addr)); 331 in6->sin6_port = nvlist_get_number(nvl, "port"); 332 break; 333 } 334 #endif 335 default: 336 return (EINVAL); 337 } 338 339 return (0); 340 } 341 342 static bool 343 ovpn_has_peers(struct ovpn_softc *sc) 344 { 345 OVPN_ASSERT(sc); 346 347 return (sc->peercount > 0); 348 } 349 350 static void 351 ovpn_rele_so(struct ovpn_softc *sc, struct ovpn_kpeer *peer) 352 { 353 bool has_peers; 354 355 OVPN_WASSERT(sc); 356 357 if (sc->so == NULL) 358 return; 359 360 has_peers = ovpn_has_peers(sc); 361 362 /* Only remove the tunnel function if we're releasing the socket for 363 * the last peer. */ 364 if (! has_peers) 365 (void)udp_set_kernel_tunneling(sc->so, NULL, NULL, NULL); 366 367 sorele(sc->so); 368 369 if (! has_peers) 370 sc->so = NULL; 371 } 372 373 static void 374 ovpn_notify_del_peer(struct ovpn_softc *sc, struct ovpn_kpeer *peer) 375 { 376 struct ovpn_notification *n; 377 378 OVPN_WASSERT(sc); 379 380 n = malloc(sizeof(*n), M_OVPN, M_NOWAIT); 381 if (n == NULL) 382 return; 383 384 n->peerid = peer->peerid; 385 n->type = OVPN_NOTIF_DEL_PEER; 386 if (buf_ring_enqueue(sc->notifring, n) != 0) { 387 free(n, M_OVPN); 388 } else if (sc->so != NULL) { 389 /* Wake up userspace */ 390 sc->so->so_error = EAGAIN; 391 sorwakeup(sc->so); 392 sowwakeup(sc->so); 393 } 394 } 395 396 static void 397 ovpn_peer_release_ref(struct ovpn_kpeer *peer, bool locked) 398 { 399 struct ovpn_softc *sc; 400 401 atomic_add_int(&peer->refcount, -1); 402 403 if (atomic_load_int(&peer->refcount) > 0) 404 return; 405 406 sc = peer->sc; 407 408 if (! locked) { 409 OVPN_WLOCK(sc); 410 411 /* Might have changed before we acquired the lock. */ 412 if (atomic_load_int(&peer->refcount) > 0) { 413 OVPN_WUNLOCK(sc); 414 return; 415 } 416 } 417 418 /* The peer should have been removed from the list already. */ 419 MPASS(ovpn_find_peer(sc, peer->peerid) == NULL); 420 421 ovpn_notify_del_peer(sc, peer); 422 423 for (int i = 0; i < 2; i++) { 424 ovpn_free_kkey_dir(peer->keys[i].encrypt); 425 ovpn_free_kkey_dir(peer->keys[i].decrypt); 426 } 427 428 ovpn_rele_so(sc, peer); 429 430 callout_stop(&peer->ping_send); 431 callout_stop(&peer->ping_rcv); 432 uma_zfree_pcpu(pcpu_zone_4, peer->last_active); 433 free(peer, M_OVPN); 434 435 if (! locked) 436 OVPN_WUNLOCK(sc); 437 } 438 439 static int 440 ovpn_new_peer(struct ifnet *ifp, const nvlist_t *nvl) 441 { 442 #ifdef INET6 443 struct epoch_tracker et; 444 #endif 445 struct sockaddr_storage remote; 446 struct ovpn_kpeer *peer = NULL; 447 struct file *fp = NULL; 448 struct sockaddr *name = NULL; 449 struct ovpn_softc *sc = ifp->if_softc; 450 struct thread *td = curthread; 451 struct socket *so = NULL; 452 int fd; 453 uint32_t peerid; 454 int ret = 0, i; 455 456 if (nvl == NULL) 457 return (EINVAL); 458 459 if (! nvlist_exists_number(nvl, "peerid")) 460 return (EINVAL); 461 462 if (! nvlist_exists_number(nvl, "fd")) 463 return (EINVAL); 464 465 if (! nvlist_exists_nvlist(nvl, "remote")) 466 return (EINVAL); 467 468 peerid = nvlist_get_number(nvl, "peerid"); 469 470 ret = ovpn_nvlist_to_sockaddr(nvlist_get_nvlist(nvl, "remote"), 471 &remote); 472 if (ret != 0) 473 return (ret); 474 475 fd = nvlist_get_number(nvl, "fd"); 476 477 /* Look up the userspace process and use the fd to find the socket. */ 478 ret = getsock(td, fd, &cap_connect_rights, &fp); 479 if (ret != 0) 480 return (ret); 481 482 so = fp->f_data; 483 484 peer = malloc(sizeof(*peer), M_OVPN, M_WAITOK | M_ZERO); 485 peer->peerid = peerid; 486 peer->sc = sc; 487 peer->tx_seq = 1; 488 peer->refcount = 1; 489 peer->last_active = uma_zalloc_pcpu(pcpu_zone_4, M_WAITOK | M_ZERO); 490 491 if (nvlist_exists_binary(nvl, "vpn_ipv4")) { 492 size_t len; 493 const void *addr = nvlist_get_binary(nvl, "vpn_ipv4", &len); 494 if (len != sizeof(peer->vpn4)) { 495 ret = EINVAL; 496 goto error; 497 } 498 memcpy(&peer->vpn4, addr, len); 499 } 500 501 if (nvlist_exists_binary(nvl, "vpn_ipv6")) { 502 size_t len; 503 const void *addr = nvlist_get_binary(nvl, "vpn_ipv6", &len); 504 if (len != sizeof(peer->vpn6)) { 505 ret = EINVAL; 506 goto error; 507 } 508 memcpy(&peer->vpn6, addr, len); 509 } 510 511 callout_init_rm(&peer->ping_send, &sc->lock, CALLOUT_SHAREDLOCK); 512 callout_init_rm(&peer->ping_rcv, &sc->lock, 0); 513 514 ret = so->so_proto->pr_sockaddr(so, &name); 515 if (ret) 516 goto error; 517 518 if (ovpn_get_port((struct sockaddr_storage *)name) == 0) { 519 ret = EINVAL; 520 goto error; 521 } 522 if (name->sa_family != remote.ss_family) { 523 ret = EINVAL; 524 goto error; 525 } 526 527 memcpy(&peer->local, name, name->sa_len); 528 memcpy(&peer->remote, &remote, sizeof(remote)); 529 free(name, M_SONAME); 530 name = NULL; 531 532 if (peer->local.ss_family == AF_INET6 && 533 IN6_IS_ADDR_V4MAPPED(&TO_IN6(&peer->remote)->sin6_addr)) { 534 /* V4 mapped address, so treat this as v4, not v6. */ 535 in6_sin6_2_sin_in_sock((struct sockaddr *)&peer->local); 536 in6_sin6_2_sin_in_sock((struct sockaddr *)&peer->remote); 537 } 538 539 #ifdef INET6 540 if (peer->local.ss_family == AF_INET6 && 541 IN6_IS_ADDR_UNSPECIFIED(&TO_IN6(&peer->local)->sin6_addr)) { 542 NET_EPOCH_ENTER(et); 543 ret = in6_selectsrc_addr(curthread->td_proc->p_fibnum, 544 &TO_IN6(&peer->remote)->sin6_addr, 545 0, NULL, &TO_IN6(&peer->local)->sin6_addr, NULL); 546 NET_EPOCH_EXIT(et); 547 if (ret != 0) { 548 goto error; 549 } 550 } 551 #endif 552 OVPN_WLOCK(sc); 553 554 /* Disallow peer id re-use. */ 555 if (ovpn_find_peer(sc, peerid) != NULL) { 556 ret = EEXIST; 557 goto error_locked; 558 } 559 560 /* Make sure this is really a UDP socket. */ 561 if (so->so_type != SOCK_DGRAM || so->so_proto->pr_type != SOCK_DGRAM) { 562 ret = EPROTOTYPE; 563 goto error_locked; 564 } 565 566 /* Must be the same socket as for other peers on this interface. */ 567 if (sc->so != NULL && so != sc->so) 568 goto error_locked; 569 570 if (sc->so == NULL) 571 sc->so = so; 572 573 /* Insert the peer into the list. */ 574 for (i = 0; i < OVPN_MAX_PEERS; i++) { 575 if (sc->peers[i] != NULL) 576 continue; 577 578 MPASS(sc->peers[i] == NULL); 579 sc->peers[i] = peer; 580 sc->peercount++; 581 soref(sc->so); 582 break; 583 } 584 if (i == OVPN_MAX_PEERS) { 585 ret = ENOSPC; 586 goto error_locked; 587 } 588 589 ret = udp_set_kernel_tunneling(sc->so, ovpn_udp_input, NULL, sc); 590 if (ret == EBUSY) { 591 /* Fine, another peer already set the input function. */ 592 ret = 0; 593 } 594 if (ret != 0) { 595 sc->peers[i] = NULL; 596 sc->peercount--; 597 goto error_locked; 598 } 599 600 OVPN_WUNLOCK(sc); 601 602 goto done; 603 604 error_locked: 605 OVPN_WUNLOCK(sc); 606 error: 607 free(name, M_SONAME); 608 uma_zfree_pcpu(pcpu_zone_4, peer->last_active); 609 free(peer, M_OVPN); 610 done: 611 if (fp != NULL) 612 fdrop(fp, td); 613 614 return (ret); 615 } 616 617 static int 618 _ovpn_del_peer(struct ovpn_softc *sc, uint32_t peerid) 619 { 620 struct ovpn_kpeer *peer; 621 int i; 622 623 OVPN_WASSERT(sc); 624 625 for (i = 0; i < OVPN_MAX_PEERS; i++) { 626 if (sc->peers[i] == NULL) 627 continue; 628 if (sc->peers[i]->peerid != peerid) 629 continue; 630 631 peer = sc->peers[i]; 632 break; 633 } 634 if (i == OVPN_MAX_PEERS) 635 return (ENOENT); 636 637 sc->peers[i] = NULL; 638 sc->peercount--; 639 640 ovpn_peer_release_ref(peer, true); 641 642 return (0); 643 } 644 645 static int 646 ovpn_del_peer(struct ifnet *ifp, nvlist_t *nvl) 647 { 648 struct ovpn_softc *sc = ifp->if_softc; 649 uint32_t peerid; 650 int ret; 651 652 OVPN_WASSERT(sc); 653 654 if (nvl == NULL) 655 return (EINVAL); 656 657 if (! nvlist_exists_number(nvl, "peerid")) 658 return (EINVAL); 659 660 peerid = nvlist_get_number(nvl, "peerid"); 661 662 ret = _ovpn_del_peer(sc, peerid); 663 664 return (ret); 665 } 666 667 static int 668 ovpn_create_kkey_dir(struct ovpn_kkey_dir **kdirp, 669 const nvlist_t *nvl) 670 { 671 struct crypto_session_params csp; 672 struct ovpn_kkey_dir *kdir; 673 const char *ciphername; 674 enum ovpn_key_cipher cipher; 675 const void *key, *iv; 676 size_t keylen = 0, ivlen = 0; 677 int error; 678 679 if (! nvlist_exists_string(nvl, "cipher")) 680 return (EINVAL); 681 ciphername = nvlist_get_string(nvl, "cipher"); 682 683 if (strcmp(ciphername, "none") == 0) 684 cipher = OVPN_CIPHER_ALG_NONE; 685 else if (strcmp(ciphername, "AES-256-GCM") == 0) 686 cipher = OVPN_CIPHER_ALG_AES_GCM; 687 else if (strcmp(ciphername, "CHACHA20-POLY1305") == 0) 688 cipher = OVPN_CIPHER_ALG_CHACHA20_POLY1305; 689 else 690 return (EINVAL); 691 692 if (cipher != OVPN_CIPHER_ALG_NONE) { 693 if (! nvlist_exists_binary(nvl, "key")) 694 return (EINVAL); 695 key = nvlist_get_binary(nvl, "key", &keylen); 696 if (keylen > sizeof(kdir->key)) 697 return (E2BIG); 698 699 if (! nvlist_exists_binary(nvl, "iv")) 700 return (EINVAL); 701 iv = nvlist_get_binary(nvl, "iv", &ivlen); 702 if (ivlen != 8) 703 return (E2BIG); 704 } 705 706 kdir = malloc(sizeof(struct ovpn_kkey_dir), M_OVPN, 707 M_WAITOK | M_ZERO); 708 709 kdir->cipher = cipher; 710 kdir->keylen = keylen; 711 memcpy(kdir->key, key, keylen); 712 kdir->noncelen = ivlen; 713 memcpy(kdir->nonce, iv, ivlen); 714 715 if (kdir->cipher != OVPN_CIPHER_ALG_NONE) { 716 /* Crypto init */ 717 bzero(&csp, sizeof(csp)); 718 csp.csp_mode = CSP_MODE_AEAD; 719 720 if (kdir->cipher == OVPN_CIPHER_ALG_CHACHA20_POLY1305) 721 csp.csp_cipher_alg = CRYPTO_CHACHA20_POLY1305; 722 else 723 csp.csp_cipher_alg = CRYPTO_AES_NIST_GCM_16; 724 725 csp.csp_flags |= CSP_F_SEPARATE_AAD; 726 727 csp.csp_cipher_klen = kdir->keylen; 728 csp.csp_cipher_key = kdir->key; 729 csp.csp_ivlen = 96 / 8; 730 731 error = crypto_newsession(&kdir->cryptoid, &csp, 732 CRYPTOCAP_F_HARDWARE | CRYPTOCAP_F_SOFTWARE); 733 if (error) { 734 free(kdir, M_OVPN); 735 return (error); 736 } 737 } 738 739 mtx_init(&kdir->replay_mtx, "if_ovpn rx replay", NULL, MTX_DEF); 740 *kdirp = kdir; 741 742 return (0); 743 } 744 745 static void 746 ovpn_free_kkey_dir(struct ovpn_kkey_dir *kdir) 747 { 748 if (kdir == NULL) 749 return; 750 751 mtx_destroy(&kdir->replay_mtx); 752 753 crypto_freesession(kdir->cryptoid); 754 free(kdir, M_OVPN); 755 } 756 757 static int 758 ovpn_set_key(struct ifnet *ifp, const nvlist_t *nvl) 759 { 760 struct ovpn_softc *sc = ifp->if_softc; 761 struct ovpn_kkey_dir *enc, *dec; 762 struct ovpn_kpeer *peer; 763 int slot, keyid, peerid; 764 int error; 765 766 if (nvl == NULL) 767 return (EINVAL); 768 769 if (! nvlist_exists_number(nvl, "slot")) 770 return (EINVAL); 771 slot = nvlist_get_number(nvl, "slot"); 772 773 if (! nvlist_exists_number(nvl, "keyid")) 774 return (EINVAL); 775 keyid = nvlist_get_number(nvl, "keyid"); 776 777 if (! nvlist_exists_number(nvl, "peerid")) 778 return (EINVAL); 779 peerid = nvlist_get_number(nvl, "peerid"); 780 781 if (slot != OVPN_KEY_SLOT_PRIMARY && 782 slot != OVPN_KEY_SLOT_SECONDARY) 783 return (EINVAL); 784 785 if (! nvlist_exists_nvlist(nvl, "encrypt") || 786 ! nvlist_exists_nvlist(nvl, "decrypt")) 787 return (EINVAL); 788 789 error = ovpn_create_kkey_dir(&enc, nvlist_get_nvlist(nvl, "encrypt")); 790 if (error) 791 return (error); 792 793 error = ovpn_create_kkey_dir(&dec, nvlist_get_nvlist(nvl, "decrypt")); 794 if (error) { 795 ovpn_free_kkey_dir(enc); 796 return (error); 797 } 798 799 OVPN_WLOCK(sc); 800 801 peer = ovpn_find_peer(sc, peerid); 802 if (peer == NULL) { 803 ovpn_free_kkey_dir(dec); 804 ovpn_free_kkey_dir(enc); 805 OVPN_WUNLOCK(sc); 806 return (ENOENT); 807 } 808 809 ovpn_free_kkey_dir(peer->keys[slot].encrypt); 810 ovpn_free_kkey_dir(peer->keys[slot].decrypt); 811 812 peer->keys[slot].encrypt = enc; 813 peer->keys[slot].decrypt = dec; 814 815 peer->keys[slot].keyid = keyid; 816 peer->keys[slot].peerid = peerid; 817 818 OVPN_WUNLOCK(sc); 819 820 return (0); 821 } 822 823 static int 824 ovpn_check_key(struct ovpn_softc *sc, struct ovpn_kpeer *peer, enum ovpn_key_slot slot) 825 { 826 OVPN_ASSERT(sc); 827 828 if (peer->keys[slot].encrypt == NULL) 829 return (ENOLINK); 830 831 if (peer->keys[slot].decrypt == NULL) 832 return (ENOLINK); 833 834 return (0); 835 } 836 837 static int 838 ovpn_start(struct ifnet *ifp) 839 { 840 struct ovpn_softc *sc = ifp->if_softc; 841 842 OVPN_WLOCK(sc); 843 844 ifp->if_flags |= IFF_UP; 845 ifp->if_drv_flags |= IFF_DRV_RUNNING; 846 if_link_state_change(ifp, LINK_STATE_UP); 847 848 OVPN_WUNLOCK(sc); 849 850 return (0); 851 } 852 853 static int 854 ovpn_swap_keys(struct ifnet *ifp, nvlist_t *nvl) 855 { 856 struct ovpn_softc *sc = ifp->if_softc; 857 struct ovpn_kpeer *peer; 858 struct ovpn_kkey tmpkey; 859 int error; 860 861 if (nvl == NULL) 862 return (EINVAL); 863 864 if (! nvlist_exists_number(nvl, "peerid")) 865 return (EINVAL); 866 867 OVPN_WLOCK(sc); 868 869 peer = ovpn_find_peer(sc, nvlist_get_number(nvl, "peerid")); 870 if (peer == NULL) { 871 OVPN_WUNLOCK(sc); 872 return (ENOENT); 873 } 874 875 /* Check that we have a second key to swap to. */ 876 error = ovpn_check_key(sc, peer, OVPN_KEY_SLOT_SECONDARY); 877 if (error) { 878 OVPN_WUNLOCK(sc); 879 return (error); 880 } 881 882 tmpkey = peer->keys[0]; 883 peer->keys[0] = peer->keys[1]; 884 peer->keys[1] = tmpkey; 885 886 OVPN_WUNLOCK(sc); 887 888 return (0); 889 } 890 891 static int 892 ovpn_del_key(struct ifnet *ifp, const nvlist_t *nvl) 893 { 894 enum ovpn_key_slot slot; 895 struct ovpn_kpeer *peer; 896 struct ovpn_softc *sc = ifp->if_softc; 897 898 if (nvl == NULL) 899 return (EINVAL); 900 901 if (! nvlist_exists_number(nvl, "peerid")) 902 return (EINVAL); 903 904 if (! nvlist_exists_number(nvl, "slot")) 905 return (EINVAL); 906 slot = nvlist_get_number(nvl, "slot"); 907 908 if (slot != OVPN_KEY_SLOT_PRIMARY && 909 slot != OVPN_KEY_SLOT_SECONDARY) 910 return (EINVAL); 911 912 OVPN_WLOCK(sc); 913 914 peer = ovpn_find_peer(sc, nvlist_get_number(nvl, "peerid")); 915 if (peer == NULL) { 916 OVPN_WUNLOCK(sc); 917 return (ENOENT); 918 } 919 920 ovpn_free_kkey_dir(peer->keys[slot].encrypt); 921 ovpn_free_kkey_dir(peer->keys[slot].decrypt); 922 923 peer->keys[slot].encrypt = NULL; 924 peer->keys[slot].decrypt = NULL; 925 926 peer->keys[slot].keyid = 0; 927 peer->keys[slot].peerid = 0; 928 929 OVPN_WUNLOCK(sc); 930 931 return (0); 932 } 933 934 static int 935 ovpn_send_pkt(struct ifnet *ifp, const nvlist_t *nvl) 936 { 937 struct epoch_tracker et; 938 struct ovpn_softc *sc = ifp->if_softc; 939 struct mbuf *m; 940 const uint8_t *pkt; 941 size_t pktlen; 942 uint32_t peerid; 943 int ret; 944 945 if (nvl == NULL) 946 return (EINVAL); 947 948 if (! nvlist_exists_binary(nvl, "packet")) 949 return (EINVAL); 950 pkt = nvlist_get_binary(nvl, "packet", &pktlen); 951 952 if (! nvlist_exists_number(nvl, "peerid")) 953 return (EINVAL); 954 955 peerid = nvlist_get_number(nvl, "peerid"); 956 957 /* 958 * Check that userspace isn't giving us a data packet. That might lead 959 * to IV re-use, which would be bad. 960 */ 961 if ((pkt[0] >> OVPN_OP_SHIFT) == OVPN_OP_DATA_V2) 962 return (EINVAL); 963 964 m = m_get2(pktlen, M_WAITOK, MT_DATA, M_PKTHDR); 965 if (m == NULL) 966 return (ENOMEM); 967 968 m->m_len = m->m_pkthdr.len = pktlen; 969 m_copyback(m, 0, m->m_len, pkt); 970 971 /* Now prepend IP/UDP headers and transmit the mbuf. */ 972 NET_EPOCH_ENTER(et); 973 ret = ovpn_encap(sc, peerid, m); 974 NET_EPOCH_EXIT(et); 975 if (ret == 0) 976 OVPN_COUNTER_ADD(sc, sent_ctrl_pkts, 1); 977 else 978 OVPN_COUNTER_ADD(sc, lost_ctrl_pkts_out, 1); 979 980 return (ret); 981 } 982 983 static void 984 ovpn_send_ping(void *arg) 985 { 986 static const uint8_t ping_str[] = { 987 0x2a, 0x18, 0x7b, 0xf3, 0x64, 0x1e, 0xb4, 0xcb, 988 0x07, 0xed, 0x2d, 0x0a, 0x98, 0x1f, 0xc7, 0x48 989 }; 990 991 struct epoch_tracker et; 992 struct ovpn_kpeer *peer = arg; 993 struct ovpn_softc *sc = peer->sc; 994 struct mbuf *m; 995 996 OVPN_RASSERT(sc); 997 998 /* Ensure we repeat! */ 999 callout_reset(&peer->ping_send, peer->keepalive.interval * hz, 1000 ovpn_send_ping, peer); 1001 1002 m = m_get2(sizeof(ping_str), M_NOWAIT, MT_DATA, M_PKTHDR); 1003 if (m == NULL) 1004 return; 1005 1006 m_copyback(m, 0, sizeof(ping_str), ping_str); 1007 m->m_len = m->m_pkthdr.len = sizeof(ping_str); 1008 1009 CURVNET_SET(sc->ifp->if_vnet); 1010 NET_EPOCH_ENTER(et); 1011 (void)ovpn_transmit_to_peer(sc->ifp, m, peer, NULL); 1012 NET_EPOCH_EXIT(et); 1013 CURVNET_RESTORE(); 1014 } 1015 1016 static void 1017 ovpn_timeout(void *arg) 1018 { 1019 struct ovpn_kpeer *peer = arg; 1020 struct ovpn_softc *sc = peer->sc; 1021 uint32_t last, _last_active; 1022 int ret __diagused; 1023 int cpu; 1024 1025 OVPN_WASSERT(sc); 1026 1027 last = 0; 1028 CPU_FOREACH(cpu) { 1029 _last_active = *zpcpu_get_cpu(peer->last_active, cpu); 1030 if (_last_active > last) 1031 last = _last_active; 1032 } 1033 1034 if (last + peer->keepalive.timeout > time_uptime) { 1035 callout_reset(&peer->ping_rcv, 1036 (peer->keepalive.timeout - (time_uptime - last)) * hz, 1037 ovpn_timeout, peer); 1038 return; 1039 } 1040 1041 CURVNET_SET(sc->ifp->if_vnet); 1042 ret = _ovpn_del_peer(sc, peer->peerid); 1043 MPASS(ret == 0); 1044 CURVNET_RESTORE(); 1045 } 1046 1047 static int 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 1085 ovpn_ioctl_set(struct ifnet *ifp, struct ifdrv *ifd) 1086 { 1087 struct ovpn_softc *sc = ifp->if_softc; 1088 uint8_t *buf = NULL; 1089 nvlist_t *nvl = NULL; 1090 int ret; 1091 1092 if (ifd->ifd_len != 0) { 1093 if (ifd->ifd_len > OVPN_MAX_REQUEST_SIZE) 1094 return (E2BIG); 1095 1096 buf = malloc(ifd->ifd_len, M_OVPN, M_WAITOK); 1097 1098 ret = copyin(ifd->ifd_data, buf, ifd->ifd_len); 1099 if (ret != 0) { 1100 free(buf, M_OVPN); 1101 return (ret); 1102 } 1103 1104 nvl = nvlist_unpack(buf, ifd->ifd_len, 0); 1105 free(buf, M_OVPN); 1106 if (nvl == NULL) { 1107 return (EINVAL); 1108 } 1109 } 1110 1111 switch (ifd->ifd_cmd) { 1112 case OVPN_NEW_PEER: 1113 ret = ovpn_new_peer(ifp, nvl); 1114 break; 1115 case OVPN_DEL_PEER: 1116 OVPN_WLOCK(sc); 1117 ret = ovpn_del_peer(ifp, nvl); 1118 OVPN_WUNLOCK(sc); 1119 break; 1120 case OVPN_NEW_KEY: 1121 ret = ovpn_set_key(ifp, nvl); 1122 break; 1123 case OVPN_START_VPN: 1124 ret = ovpn_start(ifp); 1125 break; 1126 case OVPN_SWAP_KEYS: 1127 ret = ovpn_swap_keys(ifp, nvl); 1128 break; 1129 case OVPN_DEL_KEY: 1130 ret = ovpn_del_key(ifp, nvl); 1131 break; 1132 case OVPN_SEND_PKT: 1133 ret = ovpn_send_pkt(ifp, nvl); 1134 break; 1135 case OVPN_SET_PEER: 1136 ret = ovpn_set_peer(ifp, nvl); 1137 break; 1138 default: 1139 ret = ENOTSUP; 1140 } 1141 1142 nvlist_destroy(nvl); 1143 return (ret); 1144 } 1145 1146 static int 1147 ovpn_add_counters(nvlist_t *parent, const char *name, counter_u64_t in, 1148 counter_u64_t out) 1149 { 1150 nvlist_t *nvl; 1151 1152 nvl = nvlist_create(0); 1153 if (nvl == NULL) 1154 return (ENOMEM); 1155 1156 nvlist_add_number(nvl, "in", counter_u64_fetch(in)); 1157 nvlist_add_number(nvl, "out", counter_u64_fetch(out)); 1158 1159 nvlist_add_nvlist(parent, name, nvl); 1160 1161 nvlist_destroy(nvl); 1162 1163 return (0); 1164 } 1165 1166 static int 1167 ovpn_get_stats(struct ovpn_softc *sc, nvlist_t **onvl) 1168 { 1169 nvlist_t *nvl; 1170 int ret; 1171 1172 nvl = nvlist_create(0); 1173 if (nvl == NULL) 1174 return (ENOMEM); 1175 1176 #define OVPN_COUNTER_OUT(name, in, out) \ 1177 do { \ 1178 ret = ovpn_add_counters(nvl, name, \ 1179 sc->counters[offsetof(struct ovpn_counters, in) / \ 1180 sizeof(uint64_t)], \ 1181 sc->counters[offsetof(struct ovpn_counters, out) / \ 1182 sizeof(uint64_t)]); \ 1183 if (ret != 0) \ 1184 goto error; \ 1185 } while(0) 1186 1187 OVPN_COUNTER_OUT("lost_ctrl", lost_ctrl_pkts_in, lost_ctrl_pkts_out); 1188 OVPN_COUNTER_OUT("lost_data", lost_data_pkts_in, lost_data_pkts_out); 1189 OVPN_COUNTER_OUT("nomem_data", nomem_data_pkts_in, 1190 nomem_data_pkts_out); 1191 OVPN_COUNTER_OUT("data", received_data_pkts, sent_data_pkts); 1192 OVPN_COUNTER_OUT("ctrl", received_ctrl_pkts, sent_ctrl_pkts); 1193 OVPN_COUNTER_OUT("tunnel", tunnel_bytes_received, 1194 tunnel_bytes_received); 1195 OVPN_COUNTER_OUT("transport", transport_bytes_received, 1196 transport_bytes_received); 1197 #undef OVPN_COUNTER_OUT 1198 1199 *onvl = nvl; 1200 1201 return (0); 1202 1203 error: 1204 nvlist_destroy(nvl); 1205 return (ret); 1206 } 1207 1208 static int 1209 ovpn_poll_pkt(struct ovpn_softc *sc, nvlist_t **onvl) 1210 { 1211 nvlist_t *nvl; 1212 1213 nvl = nvlist_create(0); 1214 if (nvl == NULL) 1215 return (ENOMEM); 1216 1217 nvlist_add_number(nvl, "pending", 1218 buf_ring_count(sc->rxring) + buf_ring_count(sc->notifring)); 1219 1220 *onvl = nvl; 1221 1222 return (0); 1223 } 1224 1225 static int 1226 opvn_get_pkt(struct ovpn_softc *sc, nvlist_t **onvl) 1227 { 1228 struct ovpn_notification *n; 1229 struct ovpn_wire_header *ohdr; 1230 struct mbuf *m; 1231 uint8_t *buf; 1232 nvlist_t *nvl; 1233 uint32_t peerid; 1234 u_int mlength; 1235 1236 /* Check if we have notifications pending. */ 1237 n = buf_ring_dequeue_mc(sc->notifring); 1238 if (n != NULL) { 1239 nvl = nvlist_create(0); 1240 if (nvl == NULL) { 1241 free(n, M_OVPN); 1242 return (ENOMEM); 1243 } 1244 nvlist_add_number(nvl, "peerid", n->peerid); 1245 nvlist_add_number(nvl, "notification", n->type); 1246 free(n, M_OVPN); 1247 1248 *onvl = nvl; 1249 1250 return (0); 1251 } 1252 1253 /* Queued packet. */ 1254 m = buf_ring_dequeue_mc(sc->rxring); 1255 if (m == NULL) 1256 return (ENOENT); 1257 1258 mlength = m_length(m, NULL); 1259 buf = malloc(mlength, M_NVLIST, M_WAITOK); 1260 m_copydata(m, 0, mlength, buf); 1261 ohdr = (struct ovpn_wire_header *)buf; 1262 peerid = ntohl(ohdr->opcode) & 0x00ffffff; 1263 1264 nvl = nvlist_create(0); 1265 if (nvl == NULL) { 1266 OVPN_COUNTER_ADD(sc, lost_ctrl_pkts_in, 1); 1267 m_freem(m); 1268 free(buf, M_NVLIST); 1269 return (ENOMEM); 1270 } 1271 1272 nvlist_move_binary(nvl, "packet", buf, mlength); 1273 buf = NULL; 1274 nvlist_add_number(nvl, "peerid", peerid); 1275 1276 *onvl = nvl; 1277 1278 m_freem(m); 1279 1280 return (0); 1281 } 1282 1283 static int 1284 ovpn_ioctl_get(struct ifnet *ifp, struct ifdrv *ifd) 1285 { 1286 struct ovpn_softc *sc = ifp->if_softc; 1287 nvlist_t *nvl = NULL; 1288 int error; 1289 1290 switch (ifd->ifd_cmd) { 1291 case OVPN_GET_STATS: 1292 error = ovpn_get_stats(sc, &nvl); 1293 break; 1294 case OVPN_POLL_PKT: 1295 error = ovpn_poll_pkt(sc, &nvl); 1296 break; 1297 case OVPN_GET_PKT: 1298 error = opvn_get_pkt(sc, &nvl); 1299 break; 1300 default: 1301 error = ENOTSUP; 1302 break; 1303 } 1304 1305 if (error == 0) { 1306 void *packed = NULL; 1307 size_t len; 1308 1309 MPASS(nvl != NULL); 1310 1311 packed = nvlist_pack(nvl, &len); 1312 if (! packed) { 1313 nvlist_destroy(nvl); 1314 return (ENOMEM); 1315 } 1316 1317 if (len > ifd->ifd_len) { 1318 free(packed, M_NVLIST); 1319 nvlist_destroy(nvl); 1320 return (ENOSPC); 1321 } 1322 1323 error = copyout(packed, ifd->ifd_data, len); 1324 ifd->ifd_len = len; 1325 1326 free(packed, M_NVLIST); 1327 nvlist_destroy(nvl); 1328 } 1329 1330 return (error); 1331 } 1332 1333 static int 1334 ovpn_ioctl(struct ifnet *ifp, u_long cmd, caddr_t data) 1335 { 1336 struct ifdrv *ifd; 1337 int error; 1338 1339 switch (cmd) { 1340 case SIOCSDRVSPEC: 1341 case SIOCGDRVSPEC: 1342 error = priv_check(curthread, PRIV_NET_OVPN); 1343 if (error) 1344 return (error); 1345 break; 1346 } 1347 1348 switch (cmd) { 1349 case SIOCSDRVSPEC: 1350 ifd = (struct ifdrv *)data; 1351 error = ovpn_ioctl_set(ifp, ifd); 1352 break; 1353 case SIOCGDRVSPEC: 1354 ifd = (struct ifdrv *)data; 1355 error = ovpn_ioctl_get(ifp, ifd); 1356 break; 1357 case SIOCSIFMTU: { 1358 struct ifreq *ifr = (struct ifreq *)data; 1359 if (ifr->ifr_mtu < OVPN_MTU_MIN || ifr->ifr_mtu > OVPN_MTU_MAX) 1360 return (EINVAL); 1361 1362 ifp->if_mtu = ifr->ifr_mtu; 1363 return (0); 1364 } 1365 case SIOCSIFADDR: 1366 case SIOCADDMULTI: 1367 case SIOCDELMULTI: 1368 case SIOCGIFMTU: 1369 case SIOCSIFFLAGS: 1370 return (0); 1371 default: 1372 error = EINVAL; 1373 } 1374 1375 return (error); 1376 } 1377 1378 static int 1379 ovpn_encrypt_tx_cb(struct cryptop *crp) 1380 { 1381 struct epoch_tracker et; 1382 struct ovpn_kpeer *peer = crp->crp_opaque; 1383 struct ovpn_softc *sc = peer->sc; 1384 struct mbuf *m = crp->crp_buf.cb_mbuf; 1385 int ret; 1386 1387 if (crp->crp_etype != 0) { 1388 crypto_freereq(crp); 1389 ovpn_peer_release_ref(peer, false); 1390 OVPN_COUNTER_ADD(sc, lost_data_pkts_out, 1); 1391 m_freem(m); 1392 return (0); 1393 } 1394 1395 NET_EPOCH_ENTER(et); 1396 CURVNET_SET(sc->ifp->if_vnet); 1397 1398 MPASS(crp->crp_buf.cb_type == CRYPTO_BUF_MBUF); 1399 1400 ret = ovpn_encap(sc, peer->peerid, m); 1401 if (ret == 0) { 1402 OVPN_COUNTER_ADD(sc, sent_data_pkts, 1); 1403 OVPN_COUNTER_ADD(sc, tunnel_bytes_sent, m->m_pkthdr.len - 1404 sizeof(struct ovpn_wire_header)); 1405 } 1406 1407 CURVNET_RESTORE(); 1408 NET_EPOCH_EXIT(et); 1409 1410 crypto_freereq(crp); 1411 ovpn_peer_release_ref(peer, false); 1412 1413 return (0); 1414 } 1415 1416 static void 1417 ovpn_finish_rx(struct ovpn_softc *sc, struct mbuf *m, 1418 struct ovpn_kpeer *peer, struct ovpn_kkey *key, uint32_t seq, 1419 struct rm_priotracker *_ovpn_lock_trackerp) 1420 { 1421 uint32_t af; 1422 1423 OVPN_RASSERT(sc); 1424 NET_EPOCH_ASSERT(); 1425 1426 /* Replay protection. */ 1427 if (V_replay_protection && ! ovpn_check_replay(key->decrypt, seq)) { 1428 OVPN_RUNLOCK(sc); 1429 OVPN_COUNTER_ADD(sc, lost_data_pkts_in, 1); 1430 m_freem(m); 1431 return; 1432 } 1433 1434 critical_enter(); 1435 *zpcpu_get(peer->last_active) = time_uptime; 1436 critical_exit(); 1437 1438 OVPN_RUNLOCK(sc); 1439 1440 OVPN_COUNTER_ADD(sc, received_data_pkts, 1); 1441 OVPN_COUNTER_ADD(sc, tunnel_bytes_received, m->m_pkthdr.len); 1442 1443 /* Receive the packet on our interface. */ 1444 m->m_pkthdr.rcvif = sc->ifp; 1445 1446 /* Clear checksum flags in case the real hardware set them. */ 1447 m->m_pkthdr.csum_flags = 0; 1448 1449 /* Ensure we can read the first byte. */ 1450 m = m_pullup(m, 1); 1451 if (m == NULL) { 1452 OVPN_COUNTER_ADD(sc, nomem_data_pkts_in, 1); 1453 return; 1454 } 1455 1456 /* 1457 * Check for address family, and disregard any control packets (e.g. 1458 * keepalive). 1459 */ 1460 af = ovpn_get_af(m); 1461 if (af != 0) { 1462 BPF_MTAP2(sc->ifp, &af, sizeof(af), m); 1463 netisr_dispatch(af == AF_INET ? NETISR_IP : NETISR_IPV6, m); 1464 } else { 1465 OVPN_COUNTER_ADD(sc, lost_data_pkts_in, 1); 1466 m_freem(m); 1467 } 1468 } 1469 1470 static struct ovpn_kkey * 1471 ovpn_find_key(struct ovpn_softc *sc, struct ovpn_kpeer *peer, 1472 const struct ovpn_wire_header *ohdr) 1473 { 1474 struct ovpn_kkey *key = NULL; 1475 uint8_t keyid; 1476 1477 OVPN_RASSERT(sc); 1478 1479 keyid = (ntohl(ohdr->opcode) >> 24) & 0x07; 1480 1481 if (peer->keys[0].keyid == keyid) 1482 key = &peer->keys[0]; 1483 else if (peer->keys[1].keyid == keyid) 1484 key = &peer->keys[1]; 1485 1486 return (key); 1487 } 1488 1489 static int 1490 ovpn_decrypt_rx_cb(struct cryptop *crp) 1491 { 1492 struct epoch_tracker et; 1493 struct ovpn_softc *sc = crp->crp_opaque; 1494 struct mbuf *m = crp->crp_buf.cb_mbuf; 1495 struct ovpn_kkey *key; 1496 struct ovpn_kpeer *peer; 1497 struct ovpn_wire_header *ohdr; 1498 uint32_t peerid; 1499 1500 OVPN_RLOCK_TRACKER; 1501 1502 OVPN_RLOCK(sc); 1503 1504 MPASS(crp->crp_buf.cb_type == CRYPTO_BUF_MBUF); 1505 1506 if (crp->crp_etype != 0) { 1507 crypto_freereq(crp); 1508 atomic_add_int(&sc->refcount, -1); 1509 OVPN_COUNTER_ADD(sc, lost_data_pkts_in, 1); 1510 OVPN_RUNLOCK(sc); 1511 m_freem(m); 1512 return (0); 1513 } 1514 1515 CURVNET_SET(sc->ifp->if_vnet); 1516 1517 ohdr = mtodo(m, sizeof(struct udphdr)); 1518 1519 peerid = ntohl(ohdr->opcode) & 0x00ffffff; 1520 peer = ovpn_find_peer(sc, peerid); 1521 if (peer == NULL) { 1522 /* No such peer. Drop packet. */ 1523 crypto_freereq(crp); 1524 atomic_add_int(&sc->refcount, -1); 1525 OVPN_RUNLOCK(sc); 1526 OVPN_COUNTER_ADD(sc, lost_data_pkts_in, 1); 1527 m_freem(m); 1528 CURVNET_RESTORE(); 1529 return (0); 1530 } 1531 1532 key = ovpn_find_key(sc, peer, ohdr); 1533 if (key == NULL) { 1534 crypto_freereq(crp); 1535 atomic_add_int(&sc->refcount, -1); 1536 /* 1537 * Has this key been removed between us starting the decrypt 1538 * and finishing it? 1539 */ 1540 OVPN_RUNLOCK(sc); 1541 OVPN_COUNTER_ADD(sc, lost_data_pkts_in, 1); 1542 m_freem(m); 1543 CURVNET_RESTORE(); 1544 return (0); 1545 } 1546 1547 /* Now remove the outer headers */ 1548 m_adj_decap(m, sizeof(struct udphdr) + 1549 sizeof(struct ovpn_wire_header)); 1550 1551 NET_EPOCH_ENTER(et); 1552 ovpn_finish_rx(sc, m, peer, key, ntohl(ohdr->seq), _ovpn_lock_trackerp); 1553 NET_EPOCH_EXIT(et); 1554 OVPN_UNLOCK_ASSERT(sc); 1555 1556 CURVNET_RESTORE(); 1557 1558 crypto_freereq(crp); 1559 atomic_add_int(&sc->refcount, -1); 1560 1561 return (0); 1562 } 1563 1564 static int 1565 ovpn_get_af(struct mbuf *m) 1566 { 1567 struct ip *ip; 1568 struct ip6_hdr *ip6; 1569 1570 /* 1571 * We should pullup, but we're only interested in the first byte, so 1572 * that'll always be contiguous. 1573 */ 1574 ip = mtod(m, struct ip *); 1575 if (ip->ip_v == IPVERSION) 1576 return (AF_INET); 1577 1578 ip6 = mtod(m, struct ip6_hdr *); 1579 if ((ip6->ip6_vfc & IPV6_VERSION_MASK) == IPV6_VERSION) 1580 return (AF_INET6); 1581 1582 return (0); 1583 } 1584 1585 #ifdef INET 1586 static struct ovpn_kpeer * 1587 ovpn_find_peer_by_ip(struct ovpn_softc *sc, const struct in_addr addr) 1588 { 1589 struct ovpn_kpeer *peer = NULL; 1590 1591 OVPN_ASSERT(sc); 1592 1593 for (int i = 0; i < OVPN_MAX_PEERS; i++) { 1594 if (sc->peers[i] == NULL) 1595 continue; 1596 if (addr.s_addr == sc->peers[i]->vpn4.s_addr) { 1597 peer = sc->peers[i]; 1598 break; 1599 } 1600 } 1601 1602 return (peer); 1603 } 1604 #endif 1605 1606 #ifdef INET6 1607 static struct ovpn_kpeer * 1608 ovpn_find_peer_by_ip6(struct ovpn_softc *sc, const struct in6_addr *addr) 1609 { 1610 struct ovpn_kpeer *peer = NULL; 1611 1612 OVPN_ASSERT(sc); 1613 1614 for (int i = 0; i < OVPN_MAX_PEERS; i++) { 1615 if (sc->peers[i] == NULL) 1616 continue; 1617 if (memcmp(addr, &sc->peers[i]->vpn6, sizeof(*addr)) == 0) { 1618 peer = sc->peers[i]; 1619 break; 1620 } 1621 } 1622 1623 return (peer); 1624 } 1625 #endif 1626 1627 static struct ovpn_kpeer * 1628 ovpn_route_peer(struct ovpn_softc *sc, struct mbuf **m0, 1629 const struct sockaddr *dst) 1630 { 1631 struct ovpn_kpeer *peer = NULL; 1632 int af; 1633 1634 NET_EPOCH_ASSERT(); 1635 OVPN_ASSERT(sc); 1636 1637 /* Shortcut if we're a client (or are a server and have only one client). */ 1638 if (sc->peercount == 1) 1639 return (ovpn_find_only_peer(sc)); 1640 1641 if (dst != NULL) 1642 af = dst->sa_family; 1643 else 1644 af = ovpn_get_af(*m0); 1645 1646 switch (af) { 1647 #ifdef INET 1648 case AF_INET: { 1649 const struct sockaddr_in *sa = (const struct sockaddr_in *)dst; 1650 struct nhop_object *nh; 1651 const struct in_addr *ip_dst; 1652 1653 if (sa != NULL) { 1654 ip_dst = &sa->sin_addr; 1655 } else { 1656 struct ip *ip; 1657 1658 *m0 = m_pullup(*m0, sizeof(struct ip)); 1659 if (*m0 == NULL) 1660 return (NULL); 1661 ip = mtod(*m0, struct ip *); 1662 ip_dst = &ip->ip_dst; 1663 } 1664 1665 peer = ovpn_find_peer_by_ip(sc, *ip_dst); 1666 SDT_PROBE2(if_ovpn, tx, route, ip4, ip_dst, peer); 1667 if (peer == NULL) { 1668 nh = fib4_lookup(M_GETFIB(*m0), *ip_dst, 0, 1669 NHR_NONE, 0); 1670 if (nh && (nh->nh_flags & NHF_GATEWAY)) { 1671 peer = ovpn_find_peer_by_ip(sc, 1672 nh->gw4_sa.sin_addr); 1673 SDT_PROBE2(if_ovpn, tx, route, ip4, 1674 &nh->gw4_sa.sin_addr, peer); 1675 } 1676 } 1677 break; 1678 } 1679 #endif 1680 #ifdef INET6 1681 case AF_INET6: { 1682 const struct sockaddr_in6 *sa6 = 1683 (const struct sockaddr_in6 *)dst; 1684 struct nhop_object *nh; 1685 const struct in6_addr *ip6_dst; 1686 1687 if (sa6 != NULL) { 1688 ip6_dst = &sa6->sin6_addr; 1689 } else { 1690 struct ip6_hdr *ip6; 1691 1692 *m0 = m_pullup(*m0, sizeof(struct ip6_hdr)); 1693 if (*m0 == NULL) 1694 return (NULL); 1695 ip6 = mtod(*m0, struct ip6_hdr *); 1696 ip6_dst = &ip6->ip6_dst; 1697 } 1698 1699 peer = ovpn_find_peer_by_ip6(sc, ip6_dst); 1700 SDT_PROBE2(if_ovpn, tx, route, ip6, ip6_dst, peer); 1701 if (peer == NULL) { 1702 nh = fib6_lookup(M_GETFIB(*m0), ip6_dst, 0, 1703 NHR_NONE, 0); 1704 if (nh && (nh->nh_flags & NHF_GATEWAY)) { 1705 peer = ovpn_find_peer_by_ip6(sc, 1706 &nh->gw6_sa.sin6_addr); 1707 SDT_PROBE2(if_ovpn, tx, route, ip6, 1708 &nh->gw6_sa.sin6_addr, peer); 1709 } 1710 } 1711 break; 1712 } 1713 #endif 1714 } 1715 1716 return (peer); 1717 } 1718 1719 static int 1720 ovpn_transmit(struct ifnet *ifp, struct mbuf *m) 1721 { 1722 return (ifp->if_output(ifp, m, NULL, NULL)); 1723 } 1724 1725 static int 1726 ovpn_transmit_to_peer(struct ifnet *ifp, struct mbuf *m, 1727 struct ovpn_kpeer *peer, struct rm_priotracker *_ovpn_lock_trackerp) 1728 { 1729 struct ovpn_wire_header *ohdr; 1730 struct ovpn_kkey *key; 1731 struct ovpn_softc *sc; 1732 struct cryptop *crp; 1733 uint32_t af, seq; 1734 size_t len, ovpn_hdr_len; 1735 int tunnel_len; 1736 int ret; 1737 1738 sc = ifp->if_softc; 1739 1740 OVPN_RASSERT(sc); 1741 1742 tunnel_len = m->m_pkthdr.len; 1743 1744 key = &peer->keys[OVPN_KEY_SLOT_PRIMARY]; 1745 if (key->encrypt == NULL) { 1746 if (_ovpn_lock_trackerp != NULL) 1747 OVPN_RUNLOCK(sc); 1748 m_freem(m); 1749 return (ENOLINK); 1750 } 1751 1752 af = ovpn_get_af(m); 1753 /* Don't capture control packets. */ 1754 if (af != 0) 1755 BPF_MTAP2(ifp, &af, sizeof(af), m); 1756 1757 len = m->m_pkthdr.len; 1758 MPASS(len <= ifp->if_mtu); 1759 1760 ovpn_hdr_len = sizeof(struct ovpn_wire_header); 1761 if (key->encrypt->cipher == OVPN_CIPHER_ALG_NONE) 1762 ovpn_hdr_len -= 16; /* No auth tag. */ 1763 1764 M_PREPEND(m, ovpn_hdr_len, M_NOWAIT); 1765 if (m == NULL) { 1766 if (_ovpn_lock_trackerp != NULL) 1767 OVPN_RUNLOCK(sc); 1768 OVPN_COUNTER_ADD(sc, nomem_data_pkts_out, 1); 1769 return (ENOBUFS); 1770 } 1771 ohdr = mtod(m, struct ovpn_wire_header *); 1772 ohdr->opcode = (OVPN_OP_DATA_V2 << OVPN_OP_SHIFT) | key->keyid; 1773 ohdr->opcode <<= 24; 1774 ohdr->opcode |= key->peerid; 1775 ohdr->opcode = htonl(ohdr->opcode); 1776 1777 seq = atomic_fetchadd_32(&peer->tx_seq, 1); 1778 seq = htonl(seq); 1779 ohdr->seq = seq; 1780 1781 if (key->encrypt->cipher == OVPN_CIPHER_ALG_NONE) { 1782 ret = ovpn_encap(sc, peer->peerid, m); 1783 if (_ovpn_lock_trackerp != NULL) 1784 OVPN_RUNLOCK(sc); 1785 if (ret == 0) { 1786 OVPN_COUNTER_ADD(sc, sent_data_pkts, 1); 1787 OVPN_COUNTER_ADD(sc, tunnel_bytes_sent, tunnel_len); 1788 } 1789 return (ret); 1790 } 1791 1792 crp = crypto_getreq(key->encrypt->cryptoid, M_NOWAIT); 1793 if (crp == NULL) { 1794 if (_ovpn_lock_trackerp != NULL) 1795 OVPN_RUNLOCK(sc); 1796 OVPN_COUNTER_ADD(sc, nomem_data_pkts_out, 1); 1797 m_freem(m); 1798 return (ENOBUFS); 1799 } 1800 1801 /* Encryption covers only the payload, not the header. */ 1802 crp->crp_payload_start = sizeof(*ohdr); 1803 crp->crp_payload_length = len; 1804 crp->crp_op = CRYPTO_OP_ENCRYPT; 1805 1806 /* 1807 * AAD data covers the ovpn_wire_header minus the auth 1808 * tag. 1809 */ 1810 crp->crp_aad_length = sizeof(*ohdr) - sizeof(ohdr->auth_tag); 1811 crp->crp_aad = ohdr; 1812 crp->crp_aad_start = 0; 1813 crp->crp_op |= CRYPTO_OP_COMPUTE_DIGEST; 1814 crp->crp_digest_start = offsetof(struct ovpn_wire_header, auth_tag); 1815 1816 crp->crp_flags |= CRYPTO_F_IV_SEPARATE; 1817 memcpy(crp->crp_iv, &seq, sizeof(seq)); 1818 memcpy(crp->crp_iv + sizeof(seq), key->encrypt->nonce, 1819 key->encrypt->noncelen); 1820 1821 crypto_use_mbuf(crp, m); 1822 crp->crp_flags |= CRYPTO_F_CBIFSYNC; 1823 crp->crp_callback = ovpn_encrypt_tx_cb; 1824 crp->crp_opaque = peer; 1825 1826 atomic_add_int(&peer->refcount, 1); 1827 if (_ovpn_lock_trackerp != NULL) 1828 OVPN_RUNLOCK(sc); 1829 ret = crypto_dispatch(crp); 1830 if (ret) { 1831 OVPN_COUNTER_ADD(sc, lost_data_pkts_out, 1); 1832 } 1833 1834 return (ret); 1835 } 1836 1837 /* 1838 * Note: Expects to hold the read lock on entry, and will release it itself. 1839 */ 1840 static int 1841 ovpn_encap(struct ovpn_softc *sc, uint32_t peerid, struct mbuf *m) 1842 { 1843 struct udphdr *udp; 1844 struct ovpn_kpeer *peer; 1845 int len; 1846 1847 OVPN_RLOCK_TRACKER; 1848 1849 OVPN_RLOCK(sc); 1850 NET_EPOCH_ASSERT(); 1851 1852 peer = ovpn_find_peer(sc, peerid); 1853 if (peer == NULL || sc->ifp->if_link_state != LINK_STATE_UP) { 1854 OVPN_RUNLOCK(sc); 1855 OVPN_COUNTER_ADD(sc, lost_data_pkts_out, 1); 1856 m_freem(m); 1857 return (ENETDOWN); 1858 } 1859 1860 len = m->m_pkthdr.len; 1861 1862 M_PREPEND(m, sizeof(struct udphdr), M_NOWAIT); 1863 if (m == NULL) { 1864 OVPN_RUNLOCK(sc); 1865 OVPN_COUNTER_ADD(sc, nomem_data_pkts_out, 1); 1866 m_freem(m); 1867 return (ENOBUFS); 1868 } 1869 udp = mtod(m, struct udphdr *); 1870 1871 MPASS(peer->local.ss_family == peer->remote.ss_family); 1872 1873 udp->uh_sport = ovpn_get_port(&peer->local); 1874 udp->uh_dport = ovpn_get_port(&peer->remote); 1875 udp->uh_ulen = htons(sizeof(struct udphdr) + len); 1876 1877 switch (peer->remote.ss_family) { 1878 #ifdef INET 1879 case AF_INET: { 1880 struct sockaddr_in *in_local = TO_IN(&peer->local); 1881 struct sockaddr_in *in_remote = TO_IN(&peer->remote); 1882 struct ip *ip; 1883 1884 /* 1885 * This requires knowing the source IP, which we don't. Happily 1886 * we're allowed to keep this at 0, and the checksum won't do 1887 * anything the crypto won't already do. 1888 */ 1889 udp->uh_sum = 0; 1890 1891 /* Set the checksum flags so we recalculate checksums. */ 1892 m->m_pkthdr.csum_flags |= CSUM_IP; 1893 m->m_pkthdr.csum_data = offsetof(struct udphdr, uh_sum); 1894 1895 M_PREPEND(m, sizeof(struct ip), M_NOWAIT); 1896 if (m == NULL) { 1897 OVPN_RUNLOCK(sc); 1898 OVPN_COUNTER_ADD(sc, nomem_data_pkts_out, 1); 1899 return (ENOBUFS); 1900 } 1901 ip = mtod(m, struct ip *); 1902 1903 ip->ip_tos = 0; 1904 ip->ip_len = htons(sizeof(struct ip) + sizeof(struct udphdr) + 1905 len); 1906 ip->ip_off = 0; 1907 ip->ip_ttl = V_ip_defttl; 1908 ip->ip_p = IPPROTO_UDP; 1909 ip->ip_sum = 0; 1910 if (in_local->sin_port != 0) 1911 ip->ip_src = in_local->sin_addr; 1912 else 1913 ip->ip_src.s_addr = INADDR_ANY; 1914 ip->ip_dst = in_remote->sin_addr; 1915 1916 OVPN_RUNLOCK(sc); 1917 OVPN_COUNTER_ADD(sc, transport_bytes_sent, m->m_pkthdr.len); 1918 1919 return (ip_output(m, NULL, NULL, 0, NULL, NULL)); 1920 } 1921 #endif 1922 #ifdef INET6 1923 case AF_INET6: { 1924 struct sockaddr_in6 *in6_local = TO_IN6(&peer->local); 1925 struct sockaddr_in6 *in6_remote = TO_IN6(&peer->remote); 1926 struct ip6_hdr *ip6; 1927 1928 M_PREPEND(m, sizeof(struct ip6_hdr), M_NOWAIT); 1929 if (m == NULL) { 1930 OVPN_RUNLOCK(sc); 1931 OVPN_COUNTER_ADD(sc, nomem_data_pkts_out, 1); 1932 return (ENOBUFS); 1933 } 1934 m = m_pullup(m, sizeof(*ip6) + sizeof(*udp)); 1935 if (m == NULL) { 1936 OVPN_RUNLOCK(sc); 1937 OVPN_COUNTER_ADD(sc, nomem_data_pkts_out, 1); 1938 return (ENOBUFS); 1939 } 1940 1941 ip6 = mtod(m, struct ip6_hdr *); 1942 1943 ip6->ip6_vfc = IPV6_VERSION; 1944 ip6->ip6_flow &= ~IPV6_FLOWINFO_MASK; 1945 ip6->ip6_plen = htons(sizeof(*ip6) + sizeof(struct udphdr) + 1946 len); 1947 ip6->ip6_nxt = IPPROTO_UDP; 1948 ip6->ip6_hlim = V_ip6_defhlim; 1949 1950 memcpy(&ip6->ip6_src, &in6_local->sin6_addr, 1951 sizeof(ip6->ip6_src)); 1952 memcpy(&ip6->ip6_dst, &in6_remote->sin6_addr, 1953 sizeof(ip6->ip6_dst)); 1954 1955 udp = mtodo(m, sizeof(*ip6)); 1956 udp->uh_sum = in6_cksum_pseudo(ip6, 1957 m->m_pkthdr.len - sizeof(struct ip6_hdr), 1958 IPPROTO_UDP, 0); 1959 1960 m->m_pkthdr.csum_flags |= CSUM_UDP_IPV6; 1961 m->m_pkthdr.csum_data = offsetof(struct udphdr, uh_sum); 1962 1963 OVPN_RUNLOCK(sc); 1964 OVPN_COUNTER_ADD(sc, transport_bytes_sent, m->m_pkthdr.len); 1965 1966 return (ip6_output(m, NULL, NULL, IPV6_UNSPECSRC, NULL, NULL, 1967 NULL)); 1968 } 1969 #endif 1970 default: 1971 panic("Unsupported address family %d", 1972 peer->remote.ss_family); 1973 } 1974 } 1975 1976 static int 1977 ovpn_output(struct ifnet *ifp, struct mbuf *m, const struct sockaddr *dst, 1978 struct route *ro) 1979 { 1980 struct ovpn_softc *sc; 1981 struct ovpn_kpeer *peer; 1982 1983 OVPN_RLOCK_TRACKER; 1984 1985 sc = ifp->if_softc; 1986 1987 OVPN_RLOCK(sc); 1988 1989 SDT_PROBE1(if_ovpn, tx, transmit, start, m); 1990 1991 if (__predict_false(ifp->if_link_state != LINK_STATE_UP)) { 1992 OVPN_COUNTER_ADD(sc, lost_data_pkts_out, 1); 1993 OVPN_RUNLOCK(sc); 1994 m_freem(m); 1995 return (ENETDOWN); 1996 } 1997 1998 /** 1999 * Only obey 'dst' (i.e. the gateway) if no route is supplied. 2000 * That's our indication that we're being called through pf's route-to, 2001 * and we should route according to 'dst' instead. We can't do so 2002 * consistently, because the usual openvpn configuration sets the first 2003 * non-server IP in the subnet as the gateway. If we always use that 2004 * one we'd end up routing all traffic to the first client. 2005 * tl;dr: 'ro == NULL' tells us pf is doing a route-to, and then but 2006 * only then, we should treat 'dst' as the destination. */ 2007 peer = ovpn_route_peer(sc, &m, ro == NULL ? dst : NULL); 2008 if (peer == NULL) { 2009 /* No destination. */ 2010 OVPN_COUNTER_ADD(sc, lost_data_pkts_out, 1); 2011 OVPN_RUNLOCK(sc); 2012 m_freem(m); 2013 return (ENETDOWN); 2014 } 2015 2016 return (ovpn_transmit_to_peer(ifp, m, peer, _ovpn_lock_trackerp)); 2017 } 2018 2019 static void 2020 ovpn_rcv_ctrl(struct ovpn_softc *sc, struct mbuf *m, int off) 2021 { 2022 /* Lop off the IP and UDP headers */ 2023 m_adj_decap(m, off); 2024 2025 /* Keep in the local ring until userspace fetches it. */ 2026 if (buf_ring_enqueue(sc->rxring, m) != 0) { 2027 OVPN_COUNTER_ADD(sc, lost_ctrl_pkts_in, 1); 2028 m_freem(m); 2029 return; 2030 } 2031 2032 OVPN_COUNTER_ADD(sc, received_ctrl_pkts, 1); 2033 } 2034 2035 static bool 2036 ovpn_check_replay(struct ovpn_kkey_dir *key, uint32_t seq) 2037 { 2038 uint32_t d; 2039 2040 mtx_lock(&key->replay_mtx); 2041 2042 /* Sequence number must be strictly greater than rx_seq */ 2043 if (seq <= key->rx_seq) { 2044 mtx_unlock(&key->replay_mtx); 2045 return (false); 2046 } 2047 2048 /* Large jump. The packet authenticated okay, so just accept that. */ 2049 if (seq > (key->rx_seq + (sizeof(key->rx_window) * 8))) { 2050 key->rx_seq = seq; 2051 key->rx_window = 0; 2052 mtx_unlock(&key->replay_mtx); 2053 return (true); 2054 } 2055 2056 /* Happy case. */ 2057 if ((seq == key->rx_seq + 1) && key->rx_window == 0) { 2058 key->rx_seq++; 2059 mtx_unlock(&key->replay_mtx); 2060 return (true); 2061 } 2062 2063 d = seq - key->rx_seq - 1; 2064 2065 if (key->rx_window & ((uint64_t)1 << d)) { 2066 /* Dupe! */ 2067 mtx_unlock(&key->replay_mtx); 2068 return (false); 2069 } 2070 2071 key->rx_window |= (uint64_t)1 << d; 2072 2073 while (key->rx_window & 1) { 2074 key->rx_seq++; 2075 key->rx_window >>= 1; 2076 } 2077 2078 mtx_unlock(&key->replay_mtx); 2079 2080 return (true); 2081 } 2082 2083 static struct ovpn_kpeer * 2084 ovpn_peer_from_mbuf(struct ovpn_softc *sc, struct mbuf *m, int off) 2085 { 2086 struct ovpn_wire_header ohdr; 2087 uint32_t peerid; 2088 const size_t hdrlen = sizeof(ohdr) - sizeof(ohdr.auth_tag); 2089 2090 OVPN_RASSERT(sc); 2091 2092 if (m_length(m, NULL) < (off + sizeof(struct udphdr) + hdrlen)) 2093 return (NULL); 2094 2095 m_copydata(m, off + sizeof(struct udphdr), hdrlen, (caddr_t)&ohdr); 2096 2097 peerid = ntohl(ohdr.opcode) & 0x00ffffff; 2098 2099 return (ovpn_find_peer(sc, peerid)); 2100 } 2101 2102 static bool 2103 ovpn_udp_input(struct mbuf *m, int off, struct inpcb *inp, 2104 const struct sockaddr *sa, void *ctx) 2105 { 2106 struct ovpn_softc *sc = ctx; 2107 struct ovpn_wire_header *ohdr; 2108 struct udphdr *uhdr; 2109 struct ovpn_kkey *key; 2110 struct cryptop *crp; 2111 struct ovpn_kpeer *peer; 2112 size_t ohdrlen; 2113 int ret; 2114 uint8_t op; 2115 2116 OVPN_RLOCK_TRACKER; 2117 2118 M_ASSERTPKTHDR(m); 2119 2120 OVPN_COUNTER_ADD(sc, transport_bytes_received, m->m_pkthdr.len - off); 2121 2122 ohdrlen = sizeof(*ohdr) - sizeof(ohdr->auth_tag); 2123 2124 OVPN_RLOCK(sc); 2125 2126 peer = ovpn_peer_from_mbuf(sc, m, off); 2127 if (peer == NULL) { 2128 OVPN_RUNLOCK(sc); 2129 return (false); 2130 } 2131 2132 m = m_pullup(m, off + sizeof(*uhdr) + ohdrlen); 2133 if (m == NULL) { 2134 OVPN_RUNLOCK(sc); 2135 OVPN_COUNTER_ADD(sc, nomem_data_pkts_in, 1); 2136 return (true); 2137 } 2138 uhdr = mtodo(m, off); 2139 ohdr = mtodo(m, off + sizeof(*uhdr)); 2140 2141 op = ntohl(ohdr->opcode) >> 24 >> OVPN_OP_SHIFT; 2142 2143 /* 2144 * Simplify things by getting rid of the preceding headers, we don't 2145 * care about them. 2146 */ 2147 m_adj_decap(m, off); 2148 2149 uhdr = mtodo(m, 0); 2150 ohdr = mtodo(m, sizeof(*uhdr)); 2151 2152 if (op != OVPN_OP_DATA_V2) { 2153 OVPN_RUNLOCK(sc); 2154 ovpn_rcv_ctrl(sc, m, sizeof(struct udphdr)); 2155 INP_WLOCK(inp); 2156 udp_notify(inp, EAGAIN); 2157 INP_WUNLOCK(inp); 2158 return (true); 2159 } 2160 2161 key = ovpn_find_key(sc, peer, ohdr); 2162 if (key == NULL || key->decrypt == NULL) { 2163 OVPN_RUNLOCK(sc); 2164 OVPN_COUNTER_ADD(sc, lost_data_pkts_in, 1); 2165 m_freem(m); 2166 return (true); 2167 } 2168 2169 if (key->decrypt->cipher == OVPN_CIPHER_ALG_NONE) { 2170 /* Now remove the outer headers */ 2171 m_adj_decap(m, sizeof(struct udphdr) + ohdrlen); 2172 2173 ohdr = mtodo(m, sizeof(*uhdr)); 2174 2175 ovpn_finish_rx(sc, m, peer, key, ntohl(ohdr->seq), 2176 _ovpn_lock_trackerp); 2177 OVPN_UNLOCK_ASSERT(sc); 2178 return (true); 2179 } 2180 2181 ohdrlen += sizeof(ohdr->auth_tag); 2182 2183 m = m_pullup(m, sizeof(*uhdr) + ohdrlen); 2184 if (m == NULL) { 2185 OVPN_RUNLOCK(sc); 2186 OVPN_COUNTER_ADD(sc, nomem_data_pkts_in, 1); 2187 return (true); 2188 } 2189 uhdr = mtodo(m, 0); 2190 ohdr = mtodo(m, sizeof(*uhdr)); 2191 2192 /* Decrypt */ 2193 crp = crypto_getreq(key->decrypt->cryptoid, M_NOWAIT); 2194 if (crp == NULL) { 2195 OVPN_COUNTER_ADD(sc, nomem_data_pkts_in, 1); 2196 OVPN_RUNLOCK(sc); 2197 m_freem(m); 2198 return (true); 2199 } 2200 2201 crp->crp_payload_start = sizeof(struct udphdr) + sizeof(*ohdr); 2202 crp->crp_payload_length = ntohs(uhdr->uh_ulen) - 2203 sizeof(*uhdr) - sizeof(*ohdr); 2204 crp->crp_op = CRYPTO_OP_DECRYPT; 2205 2206 /* AAD validation. */ 2207 crp->crp_aad_length = sizeof(*ohdr) - sizeof(ohdr->auth_tag); 2208 crp->crp_aad = ohdr; 2209 crp->crp_aad_start = 0; 2210 crp->crp_op |= CRYPTO_OP_VERIFY_DIGEST; 2211 crp->crp_digest_start = sizeof(struct udphdr) + 2212 offsetof(struct ovpn_wire_header, auth_tag); 2213 2214 crp->crp_flags |= CRYPTO_F_IV_SEPARATE; 2215 memcpy(crp->crp_iv, &ohdr->seq, sizeof(ohdr->seq)); 2216 memcpy(crp->crp_iv + sizeof(ohdr->seq), key->decrypt->nonce, 2217 key->decrypt->noncelen); 2218 2219 crypto_use_mbuf(crp, m); 2220 crp->crp_flags |= CRYPTO_F_CBIFSYNC; 2221 crp->crp_callback = ovpn_decrypt_rx_cb; 2222 crp->crp_opaque = sc; 2223 2224 atomic_add_int(&sc->refcount, 1); 2225 OVPN_RUNLOCK(sc); 2226 ret = crypto_dispatch(crp); 2227 if (ret != 0) { 2228 OVPN_COUNTER_ADD(sc, lost_data_pkts_in, 1); 2229 } 2230 2231 return (true); 2232 } 2233 2234 static void 2235 ovpn_qflush(struct ifnet *ifp __unused) 2236 { 2237 2238 } 2239 2240 static void 2241 ovpn_flush_rxring(struct ovpn_softc *sc) 2242 { 2243 struct mbuf *m; 2244 struct ovpn_notification *n; 2245 2246 OVPN_WASSERT(sc); 2247 2248 while (! buf_ring_empty(sc->rxring)) { 2249 m = buf_ring_dequeue_sc(sc->rxring); 2250 m_freem(m); 2251 } 2252 2253 while (! buf_ring_empty(sc->notifring)) { 2254 n = buf_ring_dequeue_sc(sc->notifring); 2255 free(n, M_OVPN); 2256 } 2257 } 2258 2259 #ifdef VIMAGE 2260 static void 2261 ovpn_reassign(struct ifnet *ifp, struct vnet *new_vnet __unused, 2262 char *unused __unused) 2263 { 2264 struct ovpn_softc *sc = ifp->if_softc; 2265 int i; 2266 int ret __diagused; 2267 2268 i = 0; 2269 2270 OVPN_WLOCK(sc); 2271 2272 /* Flush keys & configuration. */ 2273 do { 2274 if (sc->peers[i] != NULL) { 2275 ret = _ovpn_del_peer(sc, sc->peers[i]->peerid); 2276 MPASS(ret == 0); 2277 } 2278 i++; 2279 } while (i < OVPN_MAX_PEERS); 2280 2281 ovpn_flush_rxring(sc); 2282 2283 OVPN_WUNLOCK(sc); 2284 } 2285 #endif 2286 2287 static int 2288 ovpn_clone_match(struct if_clone *ifc, const char *name) 2289 { 2290 /* 2291 * Allow all names that start with 'ovpn', specifically because pfSense 2292 * uses ovpnc1 / ovpns2 2293 */ 2294 return (strncmp(ovpnname, name, strlen(ovpnname)) == 0); 2295 } 2296 2297 static int 2298 ovpn_clone_create(struct if_clone *ifc, char *name, size_t len, 2299 struct ifc_data *ifd, struct ifnet **ifpp) 2300 { 2301 struct ovpn_softc *sc; 2302 struct ifnet *ifp; 2303 char *dp; 2304 int error, unit, wildcard; 2305 2306 /* Try to see if a special unit was requested. */ 2307 error = ifc_name2unit(name, &unit); 2308 if (error != 0) 2309 return (error); 2310 wildcard = (unit < 0); 2311 2312 error = ifc_alloc_unit(ifc, &unit); 2313 if (error != 0) 2314 return (error); 2315 2316 /* 2317 * If no unit had been given, we need to adjust the ifName. 2318 */ 2319 for (dp = name; *dp != '\0'; dp++); 2320 if (wildcard) { 2321 error = snprintf(dp, len - (dp - name), "%d", unit); 2322 if (error > len - (dp - name)) { 2323 /* ifName too long. */ 2324 ifc_free_unit(ifc, unit); 2325 return (ENOSPC); 2326 } 2327 dp += error; 2328 } 2329 2330 /* Make sure it doesn't already exist. */ 2331 if (ifunit(name) != NULL) 2332 return (EEXIST); 2333 2334 sc = malloc(sizeof(struct ovpn_softc), M_OVPN, M_WAITOK | M_ZERO); 2335 sc->ifp = if_alloc(IFT_ENC); 2336 rm_init_flags(&sc->lock, "if_ovpn_lock", RM_RECURSE); 2337 sc->refcount = 0; 2338 2339 sc->rxring = buf_ring_alloc(32, M_OVPN, M_WAITOK, NULL); 2340 sc->notifring = buf_ring_alloc(32, M_OVPN, M_WAITOK, NULL); 2341 2342 COUNTER_ARRAY_ALLOC(sc->counters, OVPN_COUNTER_SIZE, M_WAITOK); 2343 2344 ifp = sc->ifp; 2345 ifp->if_softc = sc; 2346 strlcpy(ifp->if_xname, name, IFNAMSIZ); 2347 ifp->if_dname = ovpngroupname; 2348 ifp->if_dunit = unit; 2349 2350 ifp->if_addrlen = 0; 2351 ifp->if_mtu = 1428; 2352 ifp->if_flags = IFF_POINTOPOINT | IFF_MULTICAST; 2353 ifp->if_ioctl = ovpn_ioctl; 2354 ifp->if_transmit = ovpn_transmit; 2355 ifp->if_output = ovpn_output; 2356 ifp->if_qflush = ovpn_qflush; 2357 #ifdef VIMAGE 2358 ifp->if_reassign = ovpn_reassign; 2359 #endif 2360 ifp->if_capabilities |= IFCAP_LINKSTATE; 2361 ifp->if_capenable |= IFCAP_LINKSTATE; 2362 2363 if_attach(ifp); 2364 bpfattach(ifp, DLT_NULL, sizeof(uint32_t)); 2365 *ifpp = ifp; 2366 2367 return (0); 2368 } 2369 2370 static void 2371 ovpn_clone_destroy_cb(struct epoch_context *ctx) 2372 { 2373 struct ovpn_softc *sc; 2374 2375 sc = __containerof(ctx, struct ovpn_softc, epoch_ctx); 2376 2377 MPASS(sc->peercount == 0); 2378 for (int i = 0; i < OVPN_MAX_PEERS; i++) { 2379 MPASS(sc->peers[i] == NULL); 2380 } 2381 2382 COUNTER_ARRAY_FREE(sc->counters, OVPN_COUNTER_SIZE); 2383 2384 if_free(sc->ifp); 2385 free(sc, M_OVPN); 2386 } 2387 2388 static int 2389 ovpn_clone_destroy(struct if_clone *ifc, struct ifnet *ifp, uint32_t flags) 2390 { 2391 struct ovpn_softc *sc; 2392 int unit; 2393 int i; 2394 int ret __diagused; 2395 2396 sc = ifp->if_softc; 2397 unit = ifp->if_dunit; 2398 2399 OVPN_WLOCK(sc); 2400 2401 if (atomic_load_int(&sc->refcount) > 0) { 2402 OVPN_WUNLOCK(sc); 2403 return (EBUSY); 2404 } 2405 2406 i = 0; 2407 do { 2408 if (sc->peers[i] != NULL) { 2409 ret = _ovpn_del_peer(sc, sc->peers[i]->peerid); 2410 MPASS(ret == 0); 2411 } 2412 i++; 2413 } while (i < OVPN_MAX_PEERS); 2414 2415 ovpn_flush_rxring(sc); 2416 buf_ring_free(sc->rxring, M_OVPN); 2417 buf_ring_free(sc->notifring, M_OVPN); 2418 2419 OVPN_WUNLOCK(sc); 2420 2421 bpfdetach(ifp); 2422 if_detach(ifp); 2423 ifp->if_softc = NULL; 2424 2425 NET_EPOCH_CALL(ovpn_clone_destroy_cb, &sc->epoch_ctx); 2426 2427 if (unit != IF_DUNIT_NONE) 2428 ifc_free_unit(ifc, unit); 2429 2430 NET_EPOCH_DRAIN_CALLBACKS(); 2431 2432 return (0); 2433 } 2434 2435 static void 2436 vnet_ovpn_init(const void *unused __unused) 2437 { 2438 struct if_clone_addreq req = { 2439 .match_f = ovpn_clone_match, 2440 .create_f = ovpn_clone_create, 2441 .destroy_f = ovpn_clone_destroy, 2442 }; 2443 V_ovpn_cloner = ifc_attach_cloner(ovpngroupname, &req); 2444 } 2445 VNET_SYSINIT(vnet_ovpn_init, SI_SUB_PSEUDO, SI_ORDER_ANY, 2446 vnet_ovpn_init, NULL); 2447 2448 static void 2449 vnet_ovpn_uninit(const void *unused __unused) 2450 { 2451 if_clone_detach(V_ovpn_cloner); 2452 } 2453 VNET_SYSUNINIT(vnet_ovpn_uninit, SI_SUB_PSEUDO, SI_ORDER_ANY, 2454 vnet_ovpn_uninit, NULL); 2455 2456 static int 2457 ovpnmodevent(module_t mod, int type, void *data) 2458 { 2459 switch (type) { 2460 case MOD_LOAD: 2461 /* Done in vnet_ovpn_init() */ 2462 break; 2463 case MOD_UNLOAD: 2464 /* Done in vnet_ovpn_uninit() */ 2465 break; 2466 default: 2467 return (EOPNOTSUPP); 2468 } 2469 2470 return (0); 2471 } 2472 2473 static moduledata_t ovpn_mod = { 2474 "if_ovpn", 2475 ovpnmodevent, 2476 0 2477 }; 2478 2479 DECLARE_MODULE(if_ovpn, ovpn_mod, SI_SUB_PSEUDO, SI_ORDER_ANY); 2480 MODULE_VERSION(if_ovpn, 1); 2481