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 u_int fflag; 453 int fd; 454 uint32_t peerid; 455 int ret = 0, i; 456 457 if (nvl == NULL) 458 return (EINVAL); 459 460 if (! nvlist_exists_number(nvl, "peerid")) 461 return (EINVAL); 462 463 if (! nvlist_exists_number(nvl, "fd")) 464 return (EINVAL); 465 466 if (! nvlist_exists_nvlist(nvl, "remote")) 467 return (EINVAL); 468 469 peerid = nvlist_get_number(nvl, "peerid"); 470 471 ret = ovpn_nvlist_to_sockaddr(nvlist_get_nvlist(nvl, "remote"), 472 &remote); 473 if (ret != 0) 474 return (ret); 475 476 fd = nvlist_get_number(nvl, "fd"); 477 478 /* Look up the userspace process and use the fd to find the socket. */ 479 ret = getsock_cap(td, fd, &cap_connect_rights, &fp, 480 &fflag, NULL); 481 if (ret != 0) 482 return (ret); 483 484 so = fp->f_data; 485 486 peer = malloc(sizeof(*peer), M_OVPN, M_WAITOK | M_ZERO); 487 peer->peerid = peerid; 488 peer->sc = sc; 489 peer->tx_seq = 1; 490 peer->refcount = 1; 491 peer->last_active = uma_zalloc_pcpu(pcpu_zone_4, M_WAITOK | M_ZERO); 492 493 if (nvlist_exists_binary(nvl, "vpn_ipv4")) { 494 size_t len; 495 const void *addr = nvlist_get_binary(nvl, "vpn_ipv4", &len); 496 if (len != sizeof(peer->vpn4)) { 497 ret = EINVAL; 498 goto error; 499 } 500 memcpy(&peer->vpn4, addr, len); 501 } 502 503 if (nvlist_exists_binary(nvl, "vpn_ipv6")) { 504 size_t len; 505 const void *addr = nvlist_get_binary(nvl, "vpn_ipv6", &len); 506 if (len != sizeof(peer->vpn6)) { 507 ret = EINVAL; 508 goto error; 509 } 510 memcpy(&peer->vpn6, addr, len); 511 } 512 513 callout_init_rm(&peer->ping_send, &sc->lock, CALLOUT_SHAREDLOCK); 514 callout_init_rm(&peer->ping_rcv, &sc->lock, 0); 515 516 ret = (*so->so_proto->pr_usrreqs->pru_sockaddr)(so, &name); 517 if (ret) 518 goto error; 519 520 if (ovpn_get_port((struct sockaddr_storage *)name) == 0) { 521 ret = EINVAL; 522 goto error; 523 } 524 if (name->sa_family != remote.ss_family) { 525 ret = EINVAL; 526 goto error; 527 } 528 529 memcpy(&peer->local, name, name->sa_len); 530 memcpy(&peer->remote, &remote, sizeof(remote)); 531 free(name, M_SONAME); 532 name = NULL; 533 534 if (peer->local.ss_family == AF_INET6 && 535 IN6_IS_ADDR_V4MAPPED(&TO_IN6(&peer->remote)->sin6_addr)) { 536 /* V4 mapped address, so treat this as v4, not v6. */ 537 in6_sin6_2_sin_in_sock((struct sockaddr *)&peer->local); 538 in6_sin6_2_sin_in_sock((struct sockaddr *)&peer->remote); 539 } 540 541 #ifdef INET6 542 if (peer->local.ss_family == AF_INET6 && 543 IN6_IS_ADDR_UNSPECIFIED(&TO_IN6(&peer->local)->sin6_addr)) { 544 NET_EPOCH_ENTER(et); 545 ret = in6_selectsrc_addr(curthread->td_proc->p_fibnum, 546 &TO_IN6(&peer->remote)->sin6_addr, 547 0, NULL, &TO_IN6(&peer->local)->sin6_addr, NULL); 548 NET_EPOCH_EXIT(et); 549 if (ret != 0) { 550 goto error; 551 } 552 } 553 #endif 554 OVPN_WLOCK(sc); 555 556 /* Disallow peer id re-use. */ 557 if (ovpn_find_peer(sc, peerid) != NULL) { 558 ret = EEXIST; 559 goto error_locked; 560 } 561 562 /* Make sure this is really a UDP socket. */ 563 if (so->so_type != SOCK_DGRAM || so->so_proto->pr_type != SOCK_DGRAM) { 564 ret = EPROTOTYPE; 565 goto error_locked; 566 } 567 568 /* Must be the same socket as for other peers on this interface. */ 569 if (sc->so != NULL && so != sc->so) 570 goto error_locked; 571 572 if (sc->so == NULL) 573 sc->so = so; 574 575 /* Insert the peer into the list. */ 576 for (i = 0; i < OVPN_MAX_PEERS; i++) { 577 if (sc->peers[i] != NULL) 578 continue; 579 580 MPASS(sc->peers[i] == NULL); 581 sc->peers[i] = peer; 582 sc->peercount++; 583 soref(sc->so); 584 break; 585 } 586 if (i == OVPN_MAX_PEERS) { 587 ret = ENOSPC; 588 goto error_locked; 589 } 590 591 ret = udp_set_kernel_tunneling(sc->so, ovpn_udp_input, NULL, sc); 592 if (ret == EBUSY) { 593 /* Fine, another peer already set the input function. */ 594 ret = 0; 595 } 596 if (ret != 0) { 597 sc->peers[i] = NULL; 598 sc->peercount--; 599 goto error_locked; 600 } 601 602 OVPN_WUNLOCK(sc); 603 604 goto done; 605 606 error_locked: 607 OVPN_WUNLOCK(sc); 608 error: 609 free(name, M_SONAME); 610 uma_zfree_pcpu(pcpu_zone_4, peer->last_active); 611 free(peer, M_OVPN); 612 done: 613 if (fp != NULL) 614 fdrop(fp, td); 615 616 return (ret); 617 } 618 619 static int 620 _ovpn_del_peer(struct ovpn_softc *sc, uint32_t peerid) 621 { 622 struct ovpn_kpeer *peer; 623 int i; 624 625 OVPN_WASSERT(sc); 626 627 for (i = 0; i < OVPN_MAX_PEERS; i++) { 628 if (sc->peers[i] == NULL) 629 continue; 630 if (sc->peers[i]->peerid != peerid) 631 continue; 632 633 peer = sc->peers[i]; 634 break; 635 } 636 if (i == OVPN_MAX_PEERS) 637 return (ENOENT); 638 639 sc->peers[i] = NULL; 640 sc->peercount--; 641 642 ovpn_peer_release_ref(peer, true); 643 644 return (0); 645 } 646 647 static int 648 ovpn_del_peer(struct ifnet *ifp, nvlist_t *nvl) 649 { 650 struct ovpn_softc *sc = ifp->if_softc; 651 uint32_t peerid; 652 int ret; 653 654 OVPN_WASSERT(sc); 655 656 if (nvl == NULL) 657 return (EINVAL); 658 659 if (! nvlist_exists_number(nvl, "peerid")) 660 return (EINVAL); 661 662 peerid = nvlist_get_number(nvl, "peerid"); 663 664 ret = _ovpn_del_peer(sc, peerid); 665 666 return (ret); 667 } 668 669 static int 670 ovpn_create_kkey_dir(struct ovpn_kkey_dir **kdirp, 671 const nvlist_t *nvl) 672 { 673 struct crypto_session_params csp; 674 struct ovpn_kkey_dir *kdir; 675 const char *ciphername; 676 enum ovpn_key_cipher cipher; 677 const void *key, *iv; 678 size_t keylen = 0, ivlen = 0; 679 int error; 680 681 if (! nvlist_exists_string(nvl, "cipher")) 682 return (EINVAL); 683 ciphername = nvlist_get_string(nvl, "cipher"); 684 685 if (strcmp(ciphername, "none") == 0) 686 cipher = OVPN_CIPHER_ALG_NONE; 687 else if (strcmp(ciphername, "AES-256-GCM") == 0) 688 cipher = OVPN_CIPHER_ALG_AES_GCM; 689 else if (strcmp(ciphername, "CHACHA20-POLY1305") == 0) 690 cipher = OVPN_CIPHER_ALG_CHACHA20_POLY1305; 691 else 692 return (EINVAL); 693 694 if (cipher != OVPN_CIPHER_ALG_NONE) { 695 if (! nvlist_exists_binary(nvl, "key")) 696 return (EINVAL); 697 key = nvlist_get_binary(nvl, "key", &keylen); 698 if (keylen > sizeof(kdir->key)) 699 return (E2BIG); 700 701 if (! nvlist_exists_binary(nvl, "iv")) 702 return (EINVAL); 703 iv = nvlist_get_binary(nvl, "iv", &ivlen); 704 if (ivlen != 8) 705 return (E2BIG); 706 } 707 708 kdir = malloc(sizeof(struct ovpn_kkey_dir), M_OVPN, 709 M_WAITOK | M_ZERO); 710 711 kdir->cipher = cipher; 712 kdir->keylen = keylen; 713 memcpy(kdir->key, key, keylen); 714 kdir->noncelen = ivlen; 715 memcpy(kdir->nonce, iv, ivlen); 716 717 if (kdir->cipher != OVPN_CIPHER_ALG_NONE) { 718 /* Crypto init */ 719 bzero(&csp, sizeof(csp)); 720 csp.csp_mode = CSP_MODE_AEAD; 721 722 if (kdir->cipher == OVPN_CIPHER_ALG_CHACHA20_POLY1305) 723 csp.csp_cipher_alg = CRYPTO_CHACHA20_POLY1305; 724 else 725 csp.csp_cipher_alg = CRYPTO_AES_NIST_GCM_16; 726 727 csp.csp_flags |= CSP_F_SEPARATE_AAD; 728 729 csp.csp_cipher_klen = kdir->keylen; 730 csp.csp_cipher_key = kdir->key; 731 csp.csp_ivlen = 96 / 8; 732 733 error = crypto_newsession(&kdir->cryptoid, &csp, 734 CRYPTOCAP_F_HARDWARE | CRYPTOCAP_F_SOFTWARE); 735 if (error) { 736 free(kdir, M_OVPN); 737 return (error); 738 } 739 } 740 741 mtx_init(&kdir->replay_mtx, "if_ovpn rx replay", NULL, MTX_DEF); 742 *kdirp = kdir; 743 744 return (0); 745 } 746 747 static void 748 ovpn_free_kkey_dir(struct ovpn_kkey_dir *kdir) 749 { 750 if (kdir == NULL) 751 return; 752 753 mtx_destroy(&kdir->replay_mtx); 754 755 crypto_freesession(kdir->cryptoid); 756 free(kdir, M_OVPN); 757 } 758 759 static int 760 ovpn_set_key(struct ifnet *ifp, const nvlist_t *nvl) 761 { 762 struct ovpn_softc *sc = ifp->if_softc; 763 struct ovpn_kkey_dir *enc, *dec; 764 struct ovpn_kpeer *peer; 765 int slot, keyid, peerid; 766 int error; 767 768 if (nvl == NULL) 769 return (EINVAL); 770 771 if (! nvlist_exists_number(nvl, "slot")) 772 return (EINVAL); 773 slot = nvlist_get_number(nvl, "slot"); 774 775 if (! nvlist_exists_number(nvl, "keyid")) 776 return (EINVAL); 777 keyid = nvlist_get_number(nvl, "keyid"); 778 779 if (! nvlist_exists_number(nvl, "peerid")) 780 return (EINVAL); 781 peerid = nvlist_get_number(nvl, "peerid"); 782 783 if (slot != OVPN_KEY_SLOT_PRIMARY && 784 slot != OVPN_KEY_SLOT_SECONDARY) 785 return (EINVAL); 786 787 if (! nvlist_exists_nvlist(nvl, "encrypt") || 788 ! nvlist_exists_nvlist(nvl, "decrypt")) 789 return (EINVAL); 790 791 error = ovpn_create_kkey_dir(&enc, nvlist_get_nvlist(nvl, "encrypt")); 792 if (error) 793 return (error); 794 795 error = ovpn_create_kkey_dir(&dec, nvlist_get_nvlist(nvl, "decrypt")); 796 if (error) { 797 ovpn_free_kkey_dir(enc); 798 return (error); 799 } 800 801 OVPN_WLOCK(sc); 802 803 peer = ovpn_find_peer(sc, peerid); 804 if (peer == NULL) { 805 ovpn_free_kkey_dir(dec); 806 ovpn_free_kkey_dir(enc); 807 OVPN_WUNLOCK(sc); 808 return (ENOENT); 809 } 810 811 ovpn_free_kkey_dir(peer->keys[slot].encrypt); 812 ovpn_free_kkey_dir(peer->keys[slot].decrypt); 813 814 peer->keys[slot].encrypt = enc; 815 peer->keys[slot].decrypt = dec; 816 817 peer->keys[slot].keyid = keyid; 818 peer->keys[slot].peerid = peerid; 819 820 OVPN_WUNLOCK(sc); 821 822 return (0); 823 } 824 825 static int 826 ovpn_check_key(struct ovpn_softc *sc, struct ovpn_kpeer *peer, enum ovpn_key_slot slot) 827 { 828 OVPN_ASSERT(sc); 829 830 if (peer->keys[slot].encrypt == NULL) 831 return (ENOLINK); 832 833 if (peer->keys[slot].decrypt == NULL) 834 return (ENOLINK); 835 836 return (0); 837 } 838 839 static int 840 ovpn_start(struct ifnet *ifp) 841 { 842 struct ovpn_softc *sc = ifp->if_softc; 843 844 OVPN_WLOCK(sc); 845 846 ifp->if_flags |= IFF_UP; 847 ifp->if_drv_flags |= IFF_DRV_RUNNING; 848 if_link_state_change(ifp, LINK_STATE_UP); 849 850 OVPN_WUNLOCK(sc); 851 852 return (0); 853 } 854 855 static int 856 ovpn_swap_keys(struct ifnet *ifp, nvlist_t *nvl) 857 { 858 struct ovpn_softc *sc = ifp->if_softc; 859 struct ovpn_kpeer *peer; 860 struct ovpn_kkey tmpkey; 861 int error; 862 863 if (nvl == NULL) 864 return (EINVAL); 865 866 if (! nvlist_exists_number(nvl, "peerid")) 867 return (EINVAL); 868 869 OVPN_WLOCK(sc); 870 871 peer = ovpn_find_peer(sc, nvlist_get_number(nvl, "peerid")); 872 if (peer == NULL) { 873 OVPN_WUNLOCK(sc); 874 return (ENOENT); 875 } 876 877 /* Check that we have a second key to swap to. */ 878 error = ovpn_check_key(sc, peer, OVPN_KEY_SLOT_SECONDARY); 879 if (error) { 880 OVPN_WUNLOCK(sc); 881 return (error); 882 } 883 884 tmpkey = peer->keys[0]; 885 peer->keys[0] = peer->keys[1]; 886 peer->keys[1] = tmpkey; 887 888 OVPN_WUNLOCK(sc); 889 890 return (0); 891 } 892 893 static int 894 ovpn_del_key(struct ifnet *ifp, const nvlist_t *nvl) 895 { 896 enum ovpn_key_slot slot; 897 struct ovpn_kpeer *peer; 898 struct ovpn_softc *sc = ifp->if_softc; 899 900 if (nvl == NULL) 901 return (EINVAL); 902 903 if (! nvlist_exists_number(nvl, "peerid")) 904 return (EINVAL); 905 906 if (! nvlist_exists_number(nvl, "slot")) 907 return (EINVAL); 908 slot = nvlist_get_number(nvl, "slot"); 909 910 if (slot != OVPN_KEY_SLOT_PRIMARY && 911 slot != OVPN_KEY_SLOT_SECONDARY) 912 return (EINVAL); 913 914 OVPN_WLOCK(sc); 915 916 peer = ovpn_find_peer(sc, nvlist_get_number(nvl, "peerid")); 917 if (peer == NULL) { 918 OVPN_WUNLOCK(sc); 919 return (ENOENT); 920 } 921 922 ovpn_free_kkey_dir(peer->keys[slot].encrypt); 923 ovpn_free_kkey_dir(peer->keys[slot].decrypt); 924 925 peer->keys[slot].encrypt = NULL; 926 peer->keys[slot].decrypt = NULL; 927 928 peer->keys[slot].keyid = 0; 929 peer->keys[slot].peerid = 0; 930 931 OVPN_WUNLOCK(sc); 932 933 return (0); 934 } 935 936 static int 937 ovpn_send_pkt(struct ifnet *ifp, const nvlist_t *nvl) 938 { 939 struct epoch_tracker et; 940 struct ovpn_softc *sc = ifp->if_softc; 941 struct mbuf *m; 942 const uint8_t *pkt; 943 size_t pktlen; 944 uint32_t peerid; 945 int ret; 946 947 if (nvl == NULL) 948 return (EINVAL); 949 950 if (! nvlist_exists_binary(nvl, "packet")) 951 return (EINVAL); 952 pkt = nvlist_get_binary(nvl, "packet", &pktlen); 953 954 if (! nvlist_exists_number(nvl, "peerid")) 955 return (EINVAL); 956 957 peerid = nvlist_get_number(nvl, "peerid"); 958 959 /* 960 * Check that userspace isn't giving us a data packet. That might lead 961 * to IV re-use, which would be bad. 962 */ 963 if ((pkt[0] >> OVPN_OP_SHIFT) == OVPN_OP_DATA_V2) 964 return (EINVAL); 965 966 m = m_get2(pktlen, M_WAITOK, MT_DATA, M_PKTHDR); 967 if (m == NULL) 968 return (ENOMEM); 969 970 m->m_len = m->m_pkthdr.len = pktlen; 971 m_copyback(m, 0, m->m_len, pkt); 972 973 /* Now prepend IP/UDP headers and transmit the mbuf. */ 974 NET_EPOCH_ENTER(et); 975 ret = ovpn_encap(sc, peerid, m); 976 NET_EPOCH_EXIT(et); 977 if (ret == 0) 978 OVPN_COUNTER_ADD(sc, sent_ctrl_pkts, 1); 979 else 980 OVPN_COUNTER_ADD(sc, lost_ctrl_pkts_out, 1); 981 982 return (ret); 983 } 984 985 static void 986 ovpn_send_ping(void *arg) 987 { 988 static const uint8_t ping_str[] = { 989 0x2a, 0x18, 0x7b, 0xf3, 0x64, 0x1e, 0xb4, 0xcb, 990 0x07, 0xed, 0x2d, 0x0a, 0x98, 0x1f, 0xc7, 0x48 991 }; 992 993 struct epoch_tracker et; 994 struct ovpn_kpeer *peer = arg; 995 struct ovpn_softc *sc = peer->sc; 996 struct mbuf *m; 997 998 OVPN_RASSERT(sc); 999 1000 /* Ensure we repeat! */ 1001 callout_reset(&peer->ping_send, peer->keepalive.interval * hz, 1002 ovpn_send_ping, peer); 1003 1004 m = m_get2(sizeof(ping_str), M_NOWAIT, MT_DATA, M_PKTHDR); 1005 if (m == NULL) 1006 return; 1007 1008 m_copyback(m, 0, sizeof(ping_str), ping_str); 1009 m->m_len = m->m_pkthdr.len = sizeof(ping_str); 1010 1011 CURVNET_SET(sc->ifp->if_vnet); 1012 NET_EPOCH_ENTER(et); 1013 (void)ovpn_transmit_to_peer(sc->ifp, m, peer, NULL); 1014 NET_EPOCH_EXIT(et); 1015 CURVNET_RESTORE(); 1016 } 1017 1018 static void 1019 ovpn_timeout(void *arg) 1020 { 1021 struct ovpn_kpeer *peer = arg; 1022 struct ovpn_softc *sc = peer->sc; 1023 uint32_t last, _last_active; 1024 int ret __diagused; 1025 int cpu; 1026 1027 OVPN_WASSERT(sc); 1028 1029 last = 0; 1030 CPU_FOREACH(cpu) { 1031 _last_active = *zpcpu_get_cpu(peer->last_active, cpu); 1032 if (_last_active > last) 1033 last = _last_active; 1034 } 1035 1036 if (last + peer->keepalive.timeout > time_uptime) { 1037 callout_reset(&peer->ping_rcv, 1038 (peer->keepalive.timeout - (time_uptime - last)) * hz, 1039 ovpn_timeout, peer); 1040 return; 1041 } 1042 1043 CURVNET_SET(sc->ifp->if_vnet); 1044 ret = _ovpn_del_peer(sc, peer->peerid); 1045 MPASS(ret == 0); 1046 CURVNET_RESTORE(); 1047 } 1048 1049 static int 1050 ovpn_set_peer(struct ifnet *ifp, const nvlist_t *nvl) 1051 { 1052 struct ovpn_softc *sc = ifp->if_softc; 1053 struct ovpn_kpeer *peer; 1054 1055 if (nvl == NULL) 1056 return (EINVAL); 1057 1058 if (! nvlist_exists_number(nvl, "interval") || 1059 ! nvlist_exists_number(nvl, "timeout") || 1060 ! nvlist_exists_number(nvl, "peerid")) 1061 return (EINVAL); 1062 1063 OVPN_WLOCK(sc); 1064 1065 peer = ovpn_find_peer(sc, nvlist_get_number(nvl, "peerid")); 1066 if (peer == NULL) { 1067 OVPN_WUNLOCK(sc); 1068 return (ENOENT); 1069 } 1070 1071 peer->keepalive.interval = nvlist_get_number(nvl, "interval"); 1072 peer->keepalive.timeout = nvlist_get_number(nvl, "timeout"); 1073 1074 if (peer->keepalive.interval > 0) 1075 callout_reset(&peer->ping_send, peer->keepalive.interval * hz, 1076 ovpn_send_ping, peer); 1077 if (peer->keepalive.timeout > 0) 1078 callout_reset(&peer->ping_rcv, peer->keepalive.timeout * hz, 1079 ovpn_timeout, peer); 1080 1081 OVPN_WUNLOCK(sc); 1082 1083 return (0); 1084 } 1085 1086 static int 1087 ovpn_ioctl_set(struct ifnet *ifp, struct ifdrv *ifd) 1088 { 1089 struct ovpn_softc *sc = ifp->if_softc; 1090 uint8_t *buf = NULL; 1091 nvlist_t *nvl = NULL; 1092 int ret; 1093 1094 if (ifd->ifd_len != 0) { 1095 if (ifd->ifd_len > OVPN_MAX_REQUEST_SIZE) 1096 return (E2BIG); 1097 1098 buf = malloc(ifd->ifd_len, M_OVPN, M_WAITOK); 1099 1100 ret = copyin(ifd->ifd_data, buf, ifd->ifd_len); 1101 if (ret != 0) { 1102 free(buf, M_OVPN); 1103 return (ret); 1104 } 1105 1106 nvl = nvlist_unpack(buf, ifd->ifd_len, 0); 1107 free(buf, M_OVPN); 1108 if (nvl == NULL) { 1109 return (EINVAL); 1110 } 1111 } 1112 1113 switch (ifd->ifd_cmd) { 1114 case OVPN_NEW_PEER: 1115 ret = ovpn_new_peer(ifp, nvl); 1116 break; 1117 case OVPN_DEL_PEER: 1118 OVPN_WLOCK(sc); 1119 ret = ovpn_del_peer(ifp, nvl); 1120 OVPN_WUNLOCK(sc); 1121 break; 1122 case OVPN_NEW_KEY: 1123 ret = ovpn_set_key(ifp, nvl); 1124 break; 1125 case OVPN_START_VPN: 1126 ret = ovpn_start(ifp); 1127 break; 1128 case OVPN_SWAP_KEYS: 1129 ret = ovpn_swap_keys(ifp, nvl); 1130 break; 1131 case OVPN_DEL_KEY: 1132 ret = ovpn_del_key(ifp, nvl); 1133 break; 1134 case OVPN_SEND_PKT: 1135 ret = ovpn_send_pkt(ifp, nvl); 1136 break; 1137 case OVPN_SET_PEER: 1138 ret = ovpn_set_peer(ifp, nvl); 1139 break; 1140 default: 1141 ret = ENOTSUP; 1142 } 1143 1144 nvlist_destroy(nvl); 1145 return (ret); 1146 } 1147 1148 static int 1149 ovpn_add_counters(nvlist_t *parent, const char *name, counter_u64_t in, 1150 counter_u64_t out) 1151 { 1152 nvlist_t *nvl; 1153 1154 nvl = nvlist_create(0); 1155 if (nvl == NULL) 1156 return (ENOMEM); 1157 1158 nvlist_add_number(nvl, "in", counter_u64_fetch(in)); 1159 nvlist_add_number(nvl, "out", counter_u64_fetch(out)); 1160 1161 nvlist_add_nvlist(parent, name, nvl); 1162 1163 nvlist_destroy(nvl); 1164 1165 return (0); 1166 } 1167 1168 static int 1169 ovpn_get_stats(struct ovpn_softc *sc, nvlist_t **onvl) 1170 { 1171 nvlist_t *nvl; 1172 int ret; 1173 1174 nvl = nvlist_create(0); 1175 if (nvl == NULL) 1176 return (ENOMEM); 1177 1178 #define OVPN_COUNTER_OUT(name, in, out) \ 1179 do { \ 1180 ret = ovpn_add_counters(nvl, name, \ 1181 sc->counters[offsetof(struct ovpn_counters, in) / \ 1182 sizeof(uint64_t)], \ 1183 sc->counters[offsetof(struct ovpn_counters, out) / \ 1184 sizeof(uint64_t)]); \ 1185 if (ret != 0) \ 1186 goto error; \ 1187 } while(0) 1188 1189 OVPN_COUNTER_OUT("lost_ctrl", lost_ctrl_pkts_in, lost_ctrl_pkts_out); 1190 OVPN_COUNTER_OUT("lost_data", lost_data_pkts_in, lost_data_pkts_out); 1191 OVPN_COUNTER_OUT("nomem_data", nomem_data_pkts_in, 1192 nomem_data_pkts_out); 1193 OVPN_COUNTER_OUT("data", received_data_pkts, sent_data_pkts); 1194 OVPN_COUNTER_OUT("ctrl", received_ctrl_pkts, sent_ctrl_pkts); 1195 OVPN_COUNTER_OUT("tunnel", tunnel_bytes_received, 1196 tunnel_bytes_received); 1197 OVPN_COUNTER_OUT("transport", transport_bytes_received, 1198 transport_bytes_received); 1199 #undef OVPN_COUNTER_OUT 1200 1201 *onvl = nvl; 1202 1203 return (0); 1204 1205 error: 1206 nvlist_destroy(nvl); 1207 return (ret); 1208 } 1209 1210 static int 1211 ovpn_poll_pkt(struct ovpn_softc *sc, nvlist_t **onvl) 1212 { 1213 nvlist_t *nvl; 1214 1215 nvl = nvlist_create(0); 1216 if (nvl == NULL) 1217 return (ENOMEM); 1218 1219 nvlist_add_number(nvl, "pending", 1220 buf_ring_count(sc->rxring) + buf_ring_count(sc->notifring)); 1221 1222 *onvl = nvl; 1223 1224 return (0); 1225 } 1226 1227 static int 1228 opvn_get_pkt(struct ovpn_softc *sc, nvlist_t **onvl) 1229 { 1230 struct ovpn_notification *n; 1231 struct ovpn_wire_header *ohdr; 1232 struct mbuf *m; 1233 uint8_t *buf; 1234 nvlist_t *nvl; 1235 uint32_t peerid; 1236 u_int mlength; 1237 1238 /* Check if we have notifications pending. */ 1239 n = buf_ring_dequeue_mc(sc->notifring); 1240 if (n != NULL) { 1241 nvl = nvlist_create(0); 1242 if (nvl == NULL) { 1243 free(n, M_OVPN); 1244 return (ENOMEM); 1245 } 1246 nvlist_add_number(nvl, "peerid", n->peerid); 1247 nvlist_add_number(nvl, "notification", n->type); 1248 free(n, M_OVPN); 1249 1250 *onvl = nvl; 1251 1252 return (0); 1253 } 1254 1255 /* Queued packet. */ 1256 m = buf_ring_dequeue_mc(sc->rxring); 1257 if (m == NULL) 1258 return (ENOENT); 1259 1260 mlength = m_length(m, NULL); 1261 buf = malloc(mlength, M_NVLIST, M_WAITOK); 1262 m_copydata(m, 0, mlength, buf); 1263 ohdr = (struct ovpn_wire_header *)buf; 1264 peerid = ntohl(ohdr->opcode) & 0x00ffffff; 1265 1266 nvl = nvlist_create(0); 1267 if (nvl == NULL) { 1268 OVPN_COUNTER_ADD(sc, lost_ctrl_pkts_in, 1); 1269 m_freem(m); 1270 free(buf, M_NVLIST); 1271 return (ENOMEM); 1272 } 1273 1274 nvlist_move_binary(nvl, "packet", buf, mlength); 1275 buf = NULL; 1276 nvlist_add_number(nvl, "peerid", peerid); 1277 1278 *onvl = nvl; 1279 1280 m_freem(m); 1281 1282 return (0); 1283 } 1284 1285 static int 1286 ovpn_ioctl_get(struct ifnet *ifp, struct ifdrv *ifd) 1287 { 1288 struct ovpn_softc *sc = ifp->if_softc; 1289 nvlist_t *nvl = NULL; 1290 int error; 1291 1292 switch (ifd->ifd_cmd) { 1293 case OVPN_GET_STATS: 1294 error = ovpn_get_stats(sc, &nvl); 1295 break; 1296 case OVPN_POLL_PKT: 1297 error = ovpn_poll_pkt(sc, &nvl); 1298 break; 1299 case OVPN_GET_PKT: 1300 error = opvn_get_pkt(sc, &nvl); 1301 break; 1302 default: 1303 error = ENOTSUP; 1304 break; 1305 } 1306 1307 if (error == 0) { 1308 void *packed = NULL; 1309 size_t len; 1310 1311 MPASS(nvl != NULL); 1312 1313 packed = nvlist_pack(nvl, &len); 1314 if (! packed) { 1315 nvlist_destroy(nvl); 1316 return (ENOMEM); 1317 } 1318 1319 if (len > ifd->ifd_len) { 1320 free(packed, M_NVLIST); 1321 nvlist_destroy(nvl); 1322 return (ENOSPC); 1323 } 1324 1325 error = copyout(packed, ifd->ifd_data, len); 1326 ifd->ifd_len = len; 1327 1328 free(packed, M_NVLIST); 1329 nvlist_destroy(nvl); 1330 } 1331 1332 return (error); 1333 } 1334 1335 static int 1336 ovpn_ioctl(struct ifnet *ifp, u_long cmd, caddr_t data) 1337 { 1338 struct ifdrv *ifd; 1339 int error; 1340 1341 switch (cmd) { 1342 case SIOCSDRVSPEC: 1343 case SIOCGDRVSPEC: 1344 error = priv_check(curthread, PRIV_NET_OVPN); 1345 if (error) 1346 return (error); 1347 break; 1348 } 1349 1350 switch (cmd) { 1351 case SIOCSDRVSPEC: 1352 ifd = (struct ifdrv *)data; 1353 error = ovpn_ioctl_set(ifp, ifd); 1354 break; 1355 case SIOCGDRVSPEC: 1356 ifd = (struct ifdrv *)data; 1357 error = ovpn_ioctl_get(ifp, ifd); 1358 break; 1359 case SIOCSIFMTU: { 1360 struct ifreq *ifr = (struct ifreq *)data; 1361 if (ifr->ifr_mtu < OVPN_MTU_MIN || ifr->ifr_mtu > OVPN_MTU_MAX) 1362 return (EINVAL); 1363 1364 ifp->if_mtu = ifr->ifr_mtu; 1365 return (0); 1366 } 1367 case SIOCSIFADDR: 1368 case SIOCADDMULTI: 1369 case SIOCDELMULTI: 1370 case SIOCGIFMTU: 1371 case SIOCSIFFLAGS: 1372 return (0); 1373 default: 1374 error = EINVAL; 1375 } 1376 1377 return (error); 1378 } 1379 1380 static int 1381 ovpn_encrypt_tx_cb(struct cryptop *crp) 1382 { 1383 struct ovpn_kpeer *peer = crp->crp_opaque; 1384 struct ovpn_softc *sc = peer->sc; 1385 struct mbuf *m = crp->crp_buf.cb_mbuf; 1386 int ret; 1387 1388 if (crp->crp_etype != 0) { 1389 crypto_freereq(crp); 1390 ovpn_peer_release_ref(peer, false); 1391 OVPN_COUNTER_ADD(sc, lost_data_pkts_out, 1); 1392 m_freem(m); 1393 return (0); 1394 } 1395 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 1409 crypto_freereq(crp); 1410 ovpn_peer_release_ref(peer, false); 1411 1412 return (0); 1413 } 1414 1415 static void 1416 ovpn_finish_rx(struct ovpn_softc *sc, struct mbuf *m, 1417 struct ovpn_kpeer *peer, struct ovpn_kkey *key, uint32_t seq, 1418 struct rm_priotracker *_ovpn_lock_trackerp) 1419 { 1420 uint32_t af; 1421 int ret __diagused; 1422 1423 OVPN_RASSERT(sc); 1424 1425 /* Replay protection. */ 1426 if (V_replay_protection && ! ovpn_check_replay(key->decrypt, seq)) { 1427 OVPN_RUNLOCK(sc); 1428 OVPN_COUNTER_ADD(sc, lost_data_pkts_in, 1); 1429 m_freem(m); 1430 return; 1431 } 1432 1433 critical_enter(); 1434 *zpcpu_get(peer->last_active) = time_uptime; 1435 critical_exit(); 1436 1437 OVPN_RUNLOCK(sc); 1438 1439 OVPN_COUNTER_ADD(sc, received_data_pkts, 1); 1440 OVPN_COUNTER_ADD(sc, tunnel_bytes_received, m->m_pkthdr.len); 1441 1442 /* Receive the packet on our interface. */ 1443 m->m_pkthdr.rcvif = sc->ifp; 1444 1445 /* Clear checksum flags in case the real hardware set them. */ 1446 m->m_pkthdr.csum_flags = 0; 1447 1448 /* Ensure we can read the first byte. */ 1449 m = m_pullup(m, 1); 1450 if (m == NULL) { 1451 OVPN_COUNTER_ADD(sc, nomem_data_pkts_in, 1); 1452 return; 1453 } 1454 1455 /* 1456 * Check for address family, and disregard any control packets (e.g. 1457 * keepalive). 1458 */ 1459 af = ovpn_get_af(m); 1460 if (af != 0) { 1461 BPF_MTAP2(sc->ifp, &af, sizeof(af), m); 1462 ret = netisr_dispatch(af == AF_INET ? NETISR_IP : NETISR_IPV6, 1463 m); 1464 MPASS(ret == 0); 1465 } else { 1466 OVPN_COUNTER_ADD(sc, lost_data_pkts_in, 1); 1467 m_freem(m); 1468 } 1469 } 1470 1471 static struct ovpn_kkey * 1472 ovpn_find_key(struct ovpn_softc *sc, struct ovpn_kpeer *peer, 1473 const struct ovpn_wire_header *ohdr) 1474 { 1475 struct ovpn_kkey *key = NULL; 1476 uint8_t keyid; 1477 1478 OVPN_RASSERT(sc); 1479 1480 keyid = (ntohl(ohdr->opcode) >> 24) & 0x07; 1481 1482 if (peer->keys[0].keyid == keyid) 1483 key = &peer->keys[0]; 1484 else if (peer->keys[1].keyid == keyid) 1485 key = &peer->keys[1]; 1486 1487 return (key); 1488 } 1489 1490 static int 1491 ovpn_decrypt_rx_cb(struct cryptop *crp) 1492 { 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 ovpn_finish_rx(sc, m, peer, key, ntohl(ohdr->seq), _ovpn_lock_trackerp); 1552 OVPN_UNLOCK_ASSERT(sc); 1553 1554 CURVNET_RESTORE(); 1555 1556 crypto_freereq(crp); 1557 atomic_add_int(&sc->refcount, -1); 1558 1559 return (0); 1560 } 1561 1562 static uint8_t EMPTY_BUFFER[AES_BLOCK_LEN]; 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) 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, real_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 real_len = len = m->m_pkthdr.len; 1758 MPASS(real_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 else { 1764 /* Round up the len to a multiple of our block size. */ 1765 len = roundup2(real_len, AES_BLOCK_LEN); 1766 1767 /* Now extend the mbuf. */ 1768 m_append(m, len - real_len, EMPTY_BUFFER); 1769 } 1770 1771 M_PREPEND(m, ovpn_hdr_len, M_NOWAIT); 1772 if (m == NULL) { 1773 if (_ovpn_lock_trackerp != NULL) 1774 OVPN_RUNLOCK(sc); 1775 OVPN_COUNTER_ADD(sc, nomem_data_pkts_out, 1); 1776 return (ENOBUFS); 1777 } 1778 ohdr = mtod(m, struct ovpn_wire_header *); 1779 ohdr->opcode = (OVPN_OP_DATA_V2 << OVPN_OP_SHIFT) | key->keyid; 1780 ohdr->opcode <<= 24; 1781 ohdr->opcode |= key->peerid; 1782 ohdr->opcode = htonl(ohdr->opcode); 1783 1784 seq = atomic_fetchadd_32(&peer->tx_seq, 1); 1785 seq = htonl(seq); 1786 ohdr->seq = seq; 1787 1788 if (key->encrypt->cipher == OVPN_CIPHER_ALG_NONE) { 1789 ret = ovpn_encap(sc, peer->peerid, m); 1790 if (_ovpn_lock_trackerp != NULL) 1791 OVPN_RUNLOCK(sc); 1792 if (ret == 0) { 1793 OVPN_COUNTER_ADD(sc, sent_data_pkts, 1); 1794 OVPN_COUNTER_ADD(sc, tunnel_bytes_sent, tunnel_len); 1795 } 1796 return (ret); 1797 } 1798 1799 crp = crypto_getreq(key->encrypt->cryptoid, M_NOWAIT); 1800 if (crp == NULL) { 1801 if (_ovpn_lock_trackerp != NULL) 1802 OVPN_RUNLOCK(sc); 1803 OVPN_COUNTER_ADD(sc, nomem_data_pkts_out, 1); 1804 m_freem(m); 1805 return (ENOBUFS); 1806 } 1807 1808 /* Encryption covers only the payload, not the header. */ 1809 crp->crp_payload_start = sizeof(*ohdr); 1810 crp->crp_payload_length = len; 1811 crp->crp_op = CRYPTO_OP_ENCRYPT; 1812 1813 /* 1814 * AAD data covers the ovpn_wire_header minus the auth 1815 * tag. 1816 */ 1817 crp->crp_aad_length = sizeof(*ohdr) - sizeof(ohdr->auth_tag); 1818 crp->crp_aad = ohdr; 1819 crp->crp_aad_start = 0; 1820 crp->crp_op |= CRYPTO_OP_COMPUTE_DIGEST; 1821 crp->crp_digest_start = offsetof(struct ovpn_wire_header, auth_tag); 1822 1823 crp->crp_flags |= CRYPTO_F_IV_SEPARATE; 1824 memcpy(crp->crp_iv, &seq, sizeof(seq)); 1825 memcpy(crp->crp_iv + sizeof(seq), key->encrypt->nonce, 1826 key->encrypt->noncelen); 1827 1828 crypto_use_mbuf(crp, m); 1829 crp->crp_flags |= CRYPTO_F_CBIFSYNC; 1830 crp->crp_callback = ovpn_encrypt_tx_cb; 1831 crp->crp_opaque = peer; 1832 1833 atomic_add_int(&peer->refcount, 1); 1834 if (_ovpn_lock_trackerp != NULL) 1835 OVPN_RUNLOCK(sc); 1836 ret = crypto_dispatch(crp); 1837 if (ret) { 1838 OVPN_COUNTER_ADD(sc, lost_data_pkts_out, 1); 1839 } 1840 1841 return (ret); 1842 } 1843 1844 /* 1845 * Note: Expects to hold the read lock on entry, and will release it itself. 1846 */ 1847 static int 1848 ovpn_encap(struct ovpn_softc *sc, uint32_t peerid, struct mbuf *m) 1849 { 1850 struct udphdr *udp; 1851 struct ovpn_kpeer *peer; 1852 int len; 1853 1854 OVPN_RLOCK_TRACKER; 1855 1856 OVPN_RLOCK(sc); 1857 NET_EPOCH_ASSERT(); 1858 1859 peer = ovpn_find_peer(sc, peerid); 1860 if (peer == NULL || sc->ifp->if_link_state != LINK_STATE_UP) { 1861 OVPN_RUNLOCK(sc); 1862 OVPN_COUNTER_ADD(sc, lost_data_pkts_out, 1); 1863 m_freem(m); 1864 return (ENETDOWN); 1865 } 1866 1867 len = m->m_pkthdr.len; 1868 1869 M_PREPEND(m, sizeof(struct udphdr), M_NOWAIT); 1870 if (m == NULL) { 1871 OVPN_RUNLOCK(sc); 1872 OVPN_COUNTER_ADD(sc, nomem_data_pkts_out, 1); 1873 m_freem(m); 1874 return (ENOBUFS); 1875 } 1876 udp = mtod(m, struct udphdr *); 1877 1878 MPASS(peer->local.ss_family == peer->remote.ss_family); 1879 1880 udp->uh_sport = ovpn_get_port(&peer->local); 1881 udp->uh_dport = ovpn_get_port(&peer->remote); 1882 udp->uh_ulen = htons(sizeof(struct udphdr) + len); 1883 1884 switch (peer->remote.ss_family) { 1885 #ifdef INET 1886 case AF_INET: { 1887 struct sockaddr_in *in_local = TO_IN(&peer->local); 1888 struct sockaddr_in *in_remote = TO_IN(&peer->remote); 1889 struct ip *ip; 1890 1891 /* 1892 * This requires knowing the source IP, which we don't. Happily 1893 * we're allowed to keep this at 0, and the checksum won't do 1894 * anything the crypto won't already do. 1895 */ 1896 udp->uh_sum = 0; 1897 1898 /* Set the checksum flags so we recalculate checksums. */ 1899 m->m_pkthdr.csum_flags |= CSUM_IP; 1900 m->m_pkthdr.csum_data = offsetof(struct udphdr, uh_sum); 1901 1902 M_PREPEND(m, sizeof(struct ip), M_NOWAIT); 1903 if (m == NULL) { 1904 OVPN_RUNLOCK(sc); 1905 OVPN_COUNTER_ADD(sc, nomem_data_pkts_out, 1); 1906 return (ENOBUFS); 1907 } 1908 ip = mtod(m, struct ip *); 1909 1910 ip->ip_tos = 0; 1911 ip->ip_len = htons(sizeof(struct ip) + sizeof(struct udphdr) + 1912 len); 1913 ip->ip_off = 0; 1914 ip->ip_ttl = V_ip_defttl; 1915 ip->ip_p = IPPROTO_UDP; 1916 ip->ip_sum = 0; 1917 if (in_local->sin_port != 0) 1918 ip->ip_src = in_local->sin_addr; 1919 else 1920 ip->ip_src.s_addr = INADDR_ANY; 1921 ip->ip_dst = in_remote->sin_addr; 1922 1923 OVPN_RUNLOCK(sc); 1924 OVPN_COUNTER_ADD(sc, transport_bytes_sent, m->m_pkthdr.len); 1925 1926 return (ip_output(m, NULL, NULL, 0, NULL, NULL)); 1927 } 1928 #endif 1929 #ifdef INET6 1930 case AF_INET6: { 1931 struct sockaddr_in6 *in6_local = TO_IN6(&peer->local); 1932 struct sockaddr_in6 *in6_remote = TO_IN6(&peer->remote); 1933 struct ip6_hdr *ip6; 1934 1935 M_PREPEND(m, sizeof(struct ip6_hdr), M_NOWAIT); 1936 if (m == NULL) { 1937 OVPN_RUNLOCK(sc); 1938 OVPN_COUNTER_ADD(sc, nomem_data_pkts_out, 1); 1939 return (ENOBUFS); 1940 } 1941 m = m_pullup(m, sizeof(*ip6) + sizeof(*udp)); 1942 if (m == NULL) { 1943 OVPN_RUNLOCK(sc); 1944 OVPN_COUNTER_ADD(sc, nomem_data_pkts_out, 1); 1945 return (ENOBUFS); 1946 } 1947 1948 ip6 = mtod(m, struct ip6_hdr *); 1949 1950 ip6->ip6_vfc = IPV6_VERSION; 1951 ip6->ip6_flow &= ~IPV6_FLOWINFO_MASK; 1952 ip6->ip6_plen = htons(sizeof(*ip6) + sizeof(struct udphdr) + 1953 len); 1954 ip6->ip6_nxt = IPPROTO_UDP; 1955 ip6->ip6_hlim = V_ip6_defhlim; 1956 1957 memcpy(&ip6->ip6_src, &in6_local->sin6_addr, 1958 sizeof(ip6->ip6_src)); 1959 memcpy(&ip6->ip6_dst, &in6_remote->sin6_addr, 1960 sizeof(ip6->ip6_dst)); 1961 1962 udp = mtodo(m, sizeof(*ip6)); 1963 udp->uh_sum = in6_cksum_pseudo(ip6, 1964 m->m_pkthdr.len - sizeof(struct ip6_hdr), 1965 IPPROTO_UDP, 0); 1966 1967 m->m_pkthdr.csum_flags |= CSUM_UDP_IPV6; 1968 m->m_pkthdr.csum_data = offsetof(struct udphdr, uh_sum); 1969 1970 OVPN_RUNLOCK(sc); 1971 OVPN_COUNTER_ADD(sc, transport_bytes_sent, m->m_pkthdr.len); 1972 1973 return (ip6_output(m, NULL, NULL, IPV6_UNSPECSRC, NULL, NULL, 1974 NULL)); 1975 } 1976 #endif 1977 default: 1978 panic("Unsupported address family %d", 1979 peer->remote.ss_family); 1980 } 1981 } 1982 1983 static int 1984 ovpn_output(struct ifnet *ifp, struct mbuf *m, const struct sockaddr *dst, 1985 struct route *ro) 1986 { 1987 struct ovpn_softc *sc; 1988 struct ovpn_kpeer *peer; 1989 1990 OVPN_RLOCK_TRACKER; 1991 1992 sc = ifp->if_softc; 1993 1994 OVPN_RLOCK(sc); 1995 1996 SDT_PROBE1(if_ovpn, tx, transmit, start, m); 1997 1998 if (__predict_false(ifp->if_link_state != LINK_STATE_UP)) { 1999 OVPN_COUNTER_ADD(sc, lost_data_pkts_out, 1); 2000 OVPN_RUNLOCK(sc); 2001 m_freem(m); 2002 return (ENETDOWN); 2003 } 2004 2005 /** 2006 * Only obey 'dst' (i.e. the gateway) if no route is supplied. 2007 * That's our indication that we're being called through pf's route-to, 2008 * and we should route according to 'dst' instead. We can't do so 2009 * consistently, because the usual openvpn configuration sets the first 2010 * non-server IP in the subnet as the gateway. If we always use that 2011 * one we'd end up routing all traffic to the first client. 2012 * tl;dr: 'ro == NULL' tells us pf is doing a route-to, and then but 2013 * only then, we should treat 'dst' as the destination. */ 2014 peer = ovpn_route_peer(sc, &m, ro == NULL ? dst : NULL); 2015 if (peer == NULL) { 2016 /* No destination. */ 2017 OVPN_COUNTER_ADD(sc, lost_data_pkts_out, 1); 2018 OVPN_RUNLOCK(sc); 2019 m_freem(m); 2020 return (ENETDOWN); 2021 } 2022 2023 return (ovpn_transmit_to_peer(ifp, m, peer, _ovpn_lock_trackerp)); 2024 } 2025 2026 static void 2027 ovpn_rcv_ctrl(struct ovpn_softc *sc, struct mbuf *m, int off) 2028 { 2029 /* Lop off the IP and UDP headers */ 2030 m_adj_decap(m, off); 2031 2032 /* Keep in the local ring until userspace fetches it. */ 2033 if (buf_ring_enqueue(sc->rxring, m) != 0) { 2034 OVPN_COUNTER_ADD(sc, lost_ctrl_pkts_in, 1); 2035 m_freem(m); 2036 return; 2037 } 2038 2039 OVPN_COUNTER_ADD(sc, received_ctrl_pkts, 1); 2040 } 2041 2042 static bool 2043 ovpn_check_replay(struct ovpn_kkey_dir *key, uint32_t seq) 2044 { 2045 uint32_t d; 2046 2047 mtx_lock(&key->replay_mtx); 2048 2049 /* Sequence number must be strictly greater than rx_seq */ 2050 if (seq <= key->rx_seq) { 2051 mtx_unlock(&key->replay_mtx); 2052 return (false); 2053 } 2054 2055 /* Large jump. The packet authenticated okay, so just accept that. */ 2056 if (seq > (key->rx_seq + (sizeof(key->rx_window) * 8))) { 2057 key->rx_seq = seq; 2058 key->rx_window = 0; 2059 mtx_unlock(&key->replay_mtx); 2060 return (true); 2061 } 2062 2063 /* Happy case. */ 2064 if ((seq == key->rx_seq + 1) && key->rx_window == 0) { 2065 key->rx_seq++; 2066 mtx_unlock(&key->replay_mtx); 2067 return (true); 2068 } 2069 2070 d = seq - key->rx_seq - 1; 2071 2072 if (key->rx_window & ((uint64_t)1 << d)) { 2073 /* Dupe! */ 2074 mtx_unlock(&key->replay_mtx); 2075 return (false); 2076 } 2077 2078 key->rx_window |= (uint64_t)1 << d; 2079 2080 while (key->rx_window & 1) { 2081 key->rx_seq++; 2082 key->rx_window >>= 1; 2083 } 2084 2085 mtx_unlock(&key->replay_mtx); 2086 2087 return (true); 2088 } 2089 2090 static struct ovpn_kpeer * 2091 ovpn_peer_from_mbuf(struct ovpn_softc *sc, struct mbuf *m, int off) 2092 { 2093 struct ovpn_wire_header ohdr; 2094 uint32_t peerid; 2095 const size_t hdrlen = sizeof(ohdr) - sizeof(ohdr.auth_tag); 2096 2097 OVPN_RASSERT(sc); 2098 2099 if (m_length(m, NULL) < (off + sizeof(struct udphdr) + hdrlen)) 2100 return (NULL); 2101 2102 m_copydata(m, off + sizeof(struct udphdr), hdrlen, (caddr_t)&ohdr); 2103 2104 peerid = ntohl(ohdr.opcode) & 0x00ffffff; 2105 2106 return (ovpn_find_peer(sc, peerid)); 2107 } 2108 2109 static bool 2110 ovpn_udp_input(struct mbuf *m, int off, struct inpcb *inp, 2111 const struct sockaddr *sa, void *ctx) 2112 { 2113 struct ovpn_softc *sc = ctx; 2114 struct ovpn_wire_header *ohdr; 2115 struct udphdr *uhdr; 2116 struct ovpn_kkey *key; 2117 struct cryptop *crp; 2118 struct ovpn_kpeer *peer; 2119 size_t ohdrlen; 2120 int ret; 2121 uint8_t op; 2122 2123 OVPN_RLOCK_TRACKER; 2124 2125 M_ASSERTPKTHDR(m); 2126 2127 OVPN_COUNTER_ADD(sc, transport_bytes_received, m->m_pkthdr.len - off); 2128 2129 ohdrlen = sizeof(*ohdr) - sizeof(ohdr->auth_tag); 2130 2131 OVPN_RLOCK(sc); 2132 2133 peer = ovpn_peer_from_mbuf(sc, m, off); 2134 if (peer == NULL) { 2135 OVPN_RUNLOCK(sc); 2136 return (false); 2137 } 2138 2139 m = m_pullup(m, off + sizeof(*uhdr) + ohdrlen); 2140 if (m == NULL) { 2141 OVPN_RUNLOCK(sc); 2142 OVPN_COUNTER_ADD(sc, nomem_data_pkts_in, 1); 2143 return (true); 2144 } 2145 uhdr = mtodo(m, off); 2146 ohdr = mtodo(m, off + sizeof(*uhdr)); 2147 2148 op = ntohl(ohdr->opcode) >> 24 >> OVPN_OP_SHIFT; 2149 2150 /* 2151 * Simplify things by getting rid of the preceding headers, we don't 2152 * care about them. 2153 */ 2154 m_adj_decap(m, off); 2155 2156 uhdr = mtodo(m, 0); 2157 ohdr = mtodo(m, sizeof(*uhdr)); 2158 2159 if (op != OVPN_OP_DATA_V2) { 2160 OVPN_RUNLOCK(sc); 2161 ovpn_rcv_ctrl(sc, m, sizeof(struct udphdr)); 2162 INP_WLOCK(inp); 2163 udp_notify(inp, EAGAIN); 2164 INP_WUNLOCK(inp); 2165 return (true); 2166 } 2167 2168 key = ovpn_find_key(sc, peer, ohdr); 2169 if (key == NULL || key->decrypt == NULL) { 2170 OVPN_RUNLOCK(sc); 2171 OVPN_COUNTER_ADD(sc, lost_data_pkts_in, 1); 2172 m_freem(m); 2173 return (true); 2174 } 2175 2176 if (key->decrypt->cipher == OVPN_CIPHER_ALG_NONE) { 2177 /* Now remove the outer headers */ 2178 m_adj_decap(m, sizeof(struct udphdr) + ohdrlen); 2179 2180 ohdr = mtodo(m, sizeof(*uhdr)); 2181 2182 ovpn_finish_rx(sc, m, peer, key, ntohl(ohdr->seq), 2183 _ovpn_lock_trackerp); 2184 OVPN_UNLOCK_ASSERT(sc); 2185 return (true); 2186 } 2187 2188 ohdrlen += sizeof(ohdr->auth_tag); 2189 2190 m = m_pullup(m, sizeof(*uhdr) + ohdrlen); 2191 if (m == NULL) { 2192 OVPN_RUNLOCK(sc); 2193 OVPN_COUNTER_ADD(sc, nomem_data_pkts_in, 1); 2194 return (true); 2195 } 2196 uhdr = mtodo(m, 0); 2197 ohdr = mtodo(m, sizeof(*uhdr)); 2198 2199 /* Decrypt */ 2200 crp = crypto_getreq(key->decrypt->cryptoid, M_NOWAIT); 2201 if (crp == NULL) { 2202 OVPN_COUNTER_ADD(sc, nomem_data_pkts_in, 1); 2203 OVPN_RUNLOCK(sc); 2204 m_freem(m); 2205 return (true); 2206 } 2207 2208 crp->crp_payload_start = sizeof(struct udphdr) + sizeof(*ohdr); 2209 crp->crp_payload_length = ntohs(uhdr->uh_ulen) - 2210 sizeof(*uhdr) - sizeof(*ohdr); 2211 crp->crp_op = CRYPTO_OP_DECRYPT; 2212 2213 /* AAD validation. */ 2214 crp->crp_aad_length = sizeof(*ohdr) - sizeof(ohdr->auth_tag); 2215 crp->crp_aad = ohdr; 2216 crp->crp_aad_start = 0; 2217 crp->crp_op |= CRYPTO_OP_VERIFY_DIGEST; 2218 crp->crp_digest_start = sizeof(struct udphdr) + 2219 offsetof(struct ovpn_wire_header, auth_tag); 2220 2221 crp->crp_flags |= CRYPTO_F_IV_SEPARATE; 2222 memcpy(crp->crp_iv, &ohdr->seq, sizeof(ohdr->seq)); 2223 memcpy(crp->crp_iv + sizeof(ohdr->seq), key->decrypt->nonce, 2224 key->decrypt->noncelen); 2225 2226 crypto_use_mbuf(crp, m); 2227 crp->crp_flags |= CRYPTO_F_CBIFSYNC; 2228 crp->crp_callback = ovpn_decrypt_rx_cb; 2229 crp->crp_opaque = sc; 2230 2231 atomic_add_int(&sc->refcount, 1); 2232 OVPN_RUNLOCK(sc); 2233 ret = crypto_dispatch(crp); 2234 if (ret != 0) { 2235 OVPN_COUNTER_ADD(sc, lost_data_pkts_in, 1); 2236 } 2237 2238 return (true); 2239 } 2240 2241 static void 2242 ovpn_qflush(struct ifnet *ifp __unused) 2243 { 2244 2245 } 2246 2247 static void 2248 ovpn_flush_rxring(struct ovpn_softc *sc) 2249 { 2250 struct mbuf *m; 2251 struct ovpn_notification *n; 2252 2253 OVPN_WASSERT(sc); 2254 2255 while (! buf_ring_empty(sc->rxring)) { 2256 m = buf_ring_dequeue_sc(sc->rxring); 2257 m_freem(m); 2258 } 2259 2260 while (! buf_ring_empty(sc->notifring)) { 2261 n = buf_ring_dequeue_sc(sc->notifring); 2262 free(n, M_OVPN); 2263 } 2264 } 2265 2266 #ifdef VIMAGE 2267 static void 2268 ovpn_reassign(struct ifnet *ifp, struct vnet *new_vnet __unused, 2269 char *unused __unused) 2270 { 2271 struct ovpn_softc *sc = ifp->if_softc; 2272 int i; 2273 int ret __diagused; 2274 2275 i = 0; 2276 2277 OVPN_WLOCK(sc); 2278 2279 /* Flush keys & configuration. */ 2280 do { 2281 if (sc->peers[i] != NULL) { 2282 ret = _ovpn_del_peer(sc, sc->peers[i]->peerid); 2283 MPASS(ret == 0); 2284 } 2285 i++; 2286 } while (i < OVPN_MAX_PEERS); 2287 2288 ovpn_flush_rxring(sc); 2289 2290 OVPN_WUNLOCK(sc); 2291 } 2292 #endif 2293 2294 static int 2295 ovpn_clone_match(struct if_clone *ifc, const char *name) 2296 { 2297 /* 2298 * Allow all names that start with 'ovpn', specifically because pfSense 2299 * uses ovpnc1 / ovpns2 2300 */ 2301 return (strncmp(ovpnname, name, strlen(ovpnname)) == 0); 2302 } 2303 2304 static int 2305 ovpn_clone_create(struct if_clone *ifc, char *name, size_t len, caddr_t params) 2306 { 2307 struct ovpn_softc *sc; 2308 struct ifnet *ifp; 2309 char *dp; 2310 int error, unit, wildcard; 2311 2312 /* Try to see if a special unit was requested. */ 2313 error = ifc_name2unit(name, &unit); 2314 if (error != 0) 2315 return (error); 2316 wildcard = (unit < 0); 2317 2318 error = ifc_alloc_unit(ifc, &unit); 2319 if (error != 0) 2320 return (error); 2321 2322 /* 2323 * If no unit had been given, we need to adjust the ifName. 2324 */ 2325 for (dp = name; *dp != '\0'; dp++); 2326 if (wildcard) { 2327 error = snprintf(dp, len - (dp - name), "%d", unit); 2328 if (error > len - (dp - name)) { 2329 /* ifName too long. */ 2330 ifc_free_unit(ifc, unit); 2331 return (ENOSPC); 2332 } 2333 dp += error; 2334 } 2335 2336 /* Make sure it doesn't already exist. */ 2337 if (ifunit(name) != NULL) 2338 return (EEXIST); 2339 2340 sc = malloc(sizeof(struct ovpn_softc), M_OVPN, M_WAITOK | M_ZERO); 2341 sc->ifp = if_alloc(IFT_ENC); 2342 rm_init_flags(&sc->lock, "if_ovpn_lock", RM_RECURSE); 2343 sc->refcount = 0; 2344 2345 sc->rxring = buf_ring_alloc(32, M_OVPN, M_WAITOK, NULL); 2346 sc->notifring = buf_ring_alloc(32, M_OVPN, M_WAITOK, NULL); 2347 2348 COUNTER_ARRAY_ALLOC(sc->counters, OVPN_COUNTER_SIZE, M_WAITOK); 2349 2350 ifp = sc->ifp; 2351 ifp->if_softc = sc; 2352 strlcpy(ifp->if_xname, name, IFNAMSIZ); 2353 ifp->if_dname = ovpngroupname; 2354 ifp->if_dunit = unit; 2355 2356 ifp->if_addrlen = 0; 2357 ifp->if_mtu = 1428; 2358 ifp->if_flags = IFF_POINTOPOINT | IFF_MULTICAST; 2359 ifp->if_ioctl = ovpn_ioctl; 2360 ifp->if_transmit = ovpn_transmit; 2361 ifp->if_output = ovpn_output; 2362 ifp->if_qflush = ovpn_qflush; 2363 #ifdef VIMAGE 2364 ifp->if_reassign = ovpn_reassign; 2365 #endif 2366 ifp->if_capabilities |= IFCAP_LINKSTATE; 2367 ifp->if_capenable |= IFCAP_LINKSTATE; 2368 2369 if_attach(ifp); 2370 bpfattach(ifp, DLT_NULL, sizeof(uint32_t)); 2371 2372 return (0); 2373 } 2374 2375 static void 2376 ovpn_clone_destroy_cb(struct epoch_context *ctx) 2377 { 2378 struct ovpn_softc *sc; 2379 2380 sc = __containerof(ctx, struct ovpn_softc, epoch_ctx); 2381 2382 MPASS(sc->peercount == 0); 2383 for (int i = 0; i < OVPN_MAX_PEERS; i++) { 2384 MPASS(sc->peers[i] == NULL); 2385 } 2386 2387 COUNTER_ARRAY_FREE(sc->counters, OVPN_COUNTER_SIZE); 2388 2389 if_free(sc->ifp); 2390 free(sc, M_OVPN); 2391 } 2392 2393 static int 2394 ovpn_clone_destroy(struct if_clone *ifc, struct ifnet *ifp) 2395 { 2396 struct ovpn_softc *sc; 2397 int unit; 2398 int i; 2399 int ret __diagused; 2400 2401 sc = ifp->if_softc; 2402 unit = ifp->if_dunit; 2403 2404 OVPN_WLOCK(sc); 2405 2406 if (atomic_load_int(&sc->refcount) > 0) { 2407 OVPN_WUNLOCK(sc); 2408 return (EBUSY); 2409 } 2410 2411 i = 0; 2412 do { 2413 if (sc->peers[i] != NULL) { 2414 ret = _ovpn_del_peer(sc, sc->peers[i]->peerid); 2415 MPASS(ret == 0); 2416 } 2417 i++; 2418 } while (i < OVPN_MAX_PEERS); 2419 2420 ovpn_flush_rxring(sc); 2421 buf_ring_free(sc->rxring, M_OVPN); 2422 buf_ring_free(sc->notifring, M_OVPN); 2423 2424 OVPN_WUNLOCK(sc); 2425 2426 bpfdetach(ifp); 2427 if_detach(ifp); 2428 ifp->if_softc = NULL; 2429 2430 NET_EPOCH_CALL(ovpn_clone_destroy_cb, &sc->epoch_ctx); 2431 2432 if (unit != IF_DUNIT_NONE) 2433 ifc_free_unit(ifc, unit); 2434 2435 return (0); 2436 } 2437 2438 static void 2439 vnet_ovpn_init(const void *unused __unused) 2440 { 2441 V_ovpn_cloner = if_clone_advanced(ovpngroupname, 0, ovpn_clone_match, 2442 ovpn_clone_create, ovpn_clone_destroy); 2443 } 2444 VNET_SYSINIT(vnet_ovpn_init, SI_SUB_PSEUDO, SI_ORDER_ANY, 2445 vnet_ovpn_init, NULL); 2446 2447 static void 2448 vnet_ovpn_uninit(const void *unused __unused) 2449 { 2450 if_clone_detach(V_ovpn_cloner); 2451 } 2452 VNET_SYSUNINIT(vnet_ovpn_uninit, SI_SUB_PSEUDO, SI_ORDER_ANY, 2453 vnet_ovpn_uninit, NULL); 2454 2455 static int 2456 ovpnmodevent(module_t mod, int type, void *data) 2457 { 2458 switch (type) { 2459 case MOD_LOAD: 2460 /* Done in vnet_ovpn_init() */ 2461 break; 2462 case MOD_UNLOAD: 2463 /* Done in vnet_ovpn_uninit() */ 2464 break; 2465 default: 2466 return (EOPNOTSUPP); 2467 } 2468 2469 return (0); 2470 } 2471 2472 static moduledata_t ovpn_mod = { 2473 "if_ovpn", 2474 ovpnmodevent, 2475 0 2476 }; 2477 2478 DECLARE_MODULE(if_ovpn, ovpn_mod, SI_SUB_PSEUDO, SI_ORDER_ANY); 2479 MODULE_VERSION(if_ovpn, 1); 2480