1 /*- 2 * SPDX-License-Identifier: BSD-3-Clause 3 * 4 * Copyright (c) 1980, 1993 5 * The Regents of the University of California. All rights reserved. 6 * 7 * Redistribution and use in source and binary forms, with or without 8 * modification, are permitted provided that the following conditions 9 * are met: 10 * 1. Redistributions of source code must retain the above copyright 11 * notice, this list of conditions and the following disclaimer. 12 * 2. Redistributions in binary form must reproduce the above copyright 13 * notice, this list of conditions and the following disclaimer in the 14 * documentation and/or other materials provided with the distribution. 15 * 3. Neither the name of the University nor the names of its contributors 16 * may be used to endorse or promote products derived from this software 17 * without specific prior written permission. 18 * 19 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 20 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 21 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 22 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 23 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 24 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 25 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 26 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 27 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 28 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 29 * SUCH DAMAGE. 30 */ 31 32 #if 0 33 #ifndef lint 34 static const char copyright[] = 35 "@(#) Copyright (c) 1980, 1993\n\ 36 The Regents of the University of California. All rights reserved.\n"; 37 #endif /* not lint */ 38 39 #ifndef lint 40 static char sccsid[] = "From: @(#)swapon.c 8.1 (Berkeley) 6/5/93"; 41 #endif /* not lint */ 42 #endif 43 #include <sys/cdefs.h> 44 __FBSDID("$FreeBSD$"); 45 46 #include <sys/param.h> 47 #include <sys/capsicum.h> 48 #include <sys/disk.h> 49 #include <sys/socket.h> 50 #include <sys/sysctl.h> 51 52 #include <assert.h> 53 #include <capsicum_helpers.h> 54 #include <err.h> 55 #include <errno.h> 56 #include <fcntl.h> 57 #include <ifaddrs.h> 58 #include <netdb.h> 59 #include <paths.h> 60 #include <stdbool.h> 61 #include <stdint.h> 62 #include <stdio.h> 63 #include <stdlib.h> 64 #include <string.h> 65 #include <sysexits.h> 66 #include <unistd.h> 67 68 #include <arpa/inet.h> 69 70 #include <net/if.h> 71 #include <net/if_dl.h> 72 #include <net/route.h> 73 74 #include <netinet/in.h> 75 #include <netinet/netdump/netdump.h> 76 77 #ifdef HAVE_CRYPTO 78 #include <openssl/err.h> 79 #include <openssl/pem.h> 80 #include <openssl/rsa.h> 81 #endif 82 83 static int verbose; 84 85 static void _Noreturn 86 usage(void) 87 { 88 fprintf(stderr, 89 "usage: dumpon [-i index] [-r] [-v] [-k <pubkey>] [-Zz] <device>\n" 90 " dumpon [-i index] [-r] [-v] [-k <pubkey>] [-Zz]\n" 91 " [-g <gateway>] -s <server> -c <client> <iface>\n" 92 " dumpon [-v] off\n" 93 " dumpon [-v] -l\n"); 94 exit(EX_USAGE); 95 } 96 97 /* 98 * Look for a default route on the specified interface. 99 */ 100 static char * 101 find_gateway(const char *ifname) 102 { 103 struct ifaddrs *ifa, *ifap; 104 struct rt_msghdr *rtm; 105 struct sockaddr *sa; 106 struct sockaddr_dl *sdl; 107 struct sockaddr_in *dst, *mask, *gw; 108 char *buf, *next, *ret; 109 size_t sz; 110 int error, i, ifindex, mib[7]; 111 112 /* First look up the interface index. */ 113 if (getifaddrs(&ifap) != 0) 114 err(EX_OSERR, "getifaddrs"); 115 for (ifa = ifap; ifa != NULL; ifa = ifa->ifa_next) { 116 if (ifa->ifa_addr->sa_family != AF_LINK) 117 continue; 118 if (strcmp(ifa->ifa_name, ifname) == 0) { 119 sdl = (struct sockaddr_dl *)(void *)ifa->ifa_addr; 120 ifindex = sdl->sdl_index; 121 break; 122 } 123 } 124 if (ifa == NULL) 125 errx(1, "couldn't find interface index for '%s'", ifname); 126 freeifaddrs(ifap); 127 128 /* Now get the IPv4 routing table. */ 129 mib[0] = CTL_NET; 130 mib[1] = PF_ROUTE; 131 mib[2] = 0; 132 mib[3] = AF_INET; 133 mib[4] = NET_RT_DUMP; 134 mib[5] = 0; 135 mib[6] = -1; /* FIB */ 136 137 for (;;) { 138 if (sysctl(mib, nitems(mib), NULL, &sz, NULL, 0) != 0) 139 err(EX_OSERR, "sysctl(NET_RT_DUMP)"); 140 buf = malloc(sz); 141 error = sysctl(mib, nitems(mib), buf, &sz, NULL, 0); 142 if (error == 0) 143 break; 144 if (errno != ENOMEM) 145 err(EX_OSERR, "sysctl(NET_RT_DUMP)"); 146 free(buf); 147 } 148 149 ret = NULL; 150 for (next = buf; next < buf + sz; next += rtm->rtm_msglen) { 151 rtm = (struct rt_msghdr *)(void *)next; 152 if (rtm->rtm_version != RTM_VERSION) 153 continue; 154 if ((rtm->rtm_flags & RTF_GATEWAY) == 0 || 155 rtm->rtm_index != ifindex) 156 continue; 157 158 dst = gw = mask = NULL; 159 sa = (struct sockaddr *)(rtm + 1); 160 for (i = 0; i < RTAX_MAX; i++) { 161 if ((rtm->rtm_addrs & (1 << i)) != 0) { 162 switch (i) { 163 case RTAX_DST: 164 dst = (void *)sa; 165 break; 166 case RTAX_GATEWAY: 167 gw = (void *)sa; 168 break; 169 case RTAX_NETMASK: 170 mask = (void *)sa; 171 break; 172 } 173 } 174 sa = (struct sockaddr *)((char *)sa + SA_SIZE(sa)); 175 } 176 177 if (dst->sin_addr.s_addr == INADDR_ANY && 178 mask->sin_addr.s_addr == 0) { 179 ret = inet_ntoa(gw->sin_addr); 180 break; 181 } 182 } 183 free(buf); 184 return (ret); 185 } 186 187 static void 188 check_size(int fd, const char *fn) 189 { 190 int name[] = { CTL_HW, HW_PHYSMEM }; 191 size_t namelen = nitems(name); 192 unsigned long physmem; 193 size_t len; 194 off_t mediasize; 195 int minidump; 196 197 len = sizeof(minidump); 198 if (sysctlbyname("debug.minidump", &minidump, &len, NULL, 0) == 0 && 199 minidump == 1) 200 return; 201 len = sizeof(physmem); 202 if (sysctl(name, namelen, &physmem, &len, NULL, 0) != 0) 203 err(EX_OSERR, "can't get memory size"); 204 if (ioctl(fd, DIOCGMEDIASIZE, &mediasize) != 0) 205 err(EX_OSERR, "%s: can't get size", fn); 206 if ((uintmax_t)mediasize < (uintmax_t)physmem) { 207 if (verbose) 208 printf("%s is smaller than physical memory\n", fn); 209 exit(EX_IOERR); 210 } 211 } 212 213 #ifdef HAVE_CRYPTO 214 static void 215 genkey(const char *pubkeyfile, struct diocskerneldump_arg *kdap) 216 { 217 FILE *fp; 218 RSA *pubkey; 219 220 assert(pubkeyfile != NULL); 221 assert(kdap != NULL); 222 223 fp = NULL; 224 pubkey = NULL; 225 226 fp = fopen(pubkeyfile, "r"); 227 if (fp == NULL) 228 err(1, "Unable to open %s", pubkeyfile); 229 230 if (caph_enter() < 0) 231 err(1, "Unable to enter capability mode"); 232 233 pubkey = RSA_new(); 234 if (pubkey == NULL) { 235 errx(1, "Unable to allocate an RSA structure: %s", 236 ERR_error_string(ERR_get_error(), NULL)); 237 } 238 239 pubkey = PEM_read_RSA_PUBKEY(fp, &pubkey, NULL, NULL); 240 fclose(fp); 241 fp = NULL; 242 if (pubkey == NULL) 243 errx(1, "Unable to read data from %s.", pubkeyfile); 244 245 /* 246 * RSA keys under ~1024 bits are trivially factorable (2018). OpenSSL 247 * provides an API for RSA keys to estimate the symmetric-cipher 248 * "equivalent" bits of security (defined in NIST SP800-57), which as 249 * of this writing equates a 2048-bit RSA key to 112 symmetric cipher 250 * bits. 251 * 252 * Use this API as a seatbelt to avoid suggesting to users that their 253 * privacy is protected by encryption when the key size is insufficient 254 * to prevent compromise via factoring. 255 * 256 * Future work: Sanity check for weak 'e', and sanity check for absence 257 * of 'd' (i.e., the supplied key is a public key rather than a full 258 * keypair). 259 */ 260 #if OPENSSL_VERSION_NUMBER >= 0x10100000L 261 if (RSA_security_bits(pubkey) < 112) 262 #else 263 if (RSA_size(pubkey) * 8 < 2048) 264 #endif 265 errx(1, "Small RSA keys (you provided: %db) can be " 266 "factored cheaply. Please generate a larger key.", 267 RSA_size(pubkey) * 8); 268 269 kdap->kda_encryptedkeysize = RSA_size(pubkey); 270 if (kdap->kda_encryptedkeysize > KERNELDUMP_ENCKEY_MAX_SIZE) { 271 errx(1, "Public key has to be at most %db long.", 272 8 * KERNELDUMP_ENCKEY_MAX_SIZE); 273 } 274 275 kdap->kda_encryptedkey = calloc(1, kdap->kda_encryptedkeysize); 276 if (kdap->kda_encryptedkey == NULL) 277 err(1, "Unable to allocate encrypted key"); 278 279 /* 280 * If no cipher was specified, choose a reasonable default. 281 */ 282 if (kdap->kda_encryption == KERNELDUMP_ENC_NONE) 283 kdap->kda_encryption = KERNELDUMP_ENC_CHACHA20; 284 else if (kdap->kda_encryption == KERNELDUMP_ENC_AES_256_CBC && 285 kdap->kda_compression != KERNELDUMP_COMP_NONE) 286 errx(EX_USAGE, "Unpadded AES256-CBC mode cannot be used " 287 "with compression."); 288 289 arc4random_buf(kdap->kda_key, sizeof(kdap->kda_key)); 290 if (RSA_public_encrypt(sizeof(kdap->kda_key), kdap->kda_key, 291 kdap->kda_encryptedkey, pubkey, 292 RSA_PKCS1_PADDING) != (int)kdap->kda_encryptedkeysize) { 293 errx(1, "Unable to encrypt the one-time key."); 294 } 295 RSA_free(pubkey); 296 } 297 #endif 298 299 static void 300 listdumpdev(void) 301 { 302 static char ip[200]; 303 304 char dumpdev[PATH_MAX]; 305 struct diocskerneldump_arg ndconf; 306 size_t len; 307 const char *sysctlname = "kern.shutdown.dumpdevname"; 308 int fd; 309 310 len = sizeof(dumpdev); 311 if (sysctlbyname(sysctlname, &dumpdev, &len, NULL, 0) != 0) { 312 if (errno == ENOMEM) { 313 err(EX_OSERR, "Kernel returned too large of a buffer for '%s'\n", 314 sysctlname); 315 } else { 316 err(EX_OSERR, "Sysctl get '%s'\n", sysctlname); 317 } 318 } 319 if (strlen(dumpdev) == 0) 320 (void)strlcpy(dumpdev, _PATH_DEVNULL, sizeof(dumpdev)); 321 322 if (verbose) { 323 char *ctx, *dd; 324 unsigned idx; 325 326 printf("kernel dumps on priority: device\n"); 327 idx = 0; 328 ctx = dumpdev; 329 while ((dd = strsep(&ctx, ",")) != NULL) 330 printf("%u: %s\n", idx++, dd); 331 } else 332 printf("%s\n", dumpdev); 333 334 /* If netdump is enabled, print the configuration parameters. */ 335 if (verbose) { 336 fd = open(_PATH_NETDUMP, O_RDONLY); 337 if (fd < 0) { 338 if (errno != ENOENT) 339 err(EX_OSERR, "opening %s", _PATH_NETDUMP); 340 return; 341 } 342 if (ioctl(fd, DIOCGKERNELDUMP, &ndconf) != 0) { 343 if (errno != ENXIO) 344 err(EX_OSERR, "ioctl(DIOCGKERNELDUMP)"); 345 (void)close(fd); 346 return; 347 } 348 349 printf("server address: %s\n", 350 inet_ntop(ndconf.kda_af, &ndconf.kda_server, ip, 351 sizeof(ip))); 352 printf("client address: %s\n", 353 inet_ntop(ndconf.kda_af, &ndconf.kda_client, ip, 354 sizeof(ip))); 355 printf("gateway address: %s\n", 356 inet_ntop(ndconf.kda_af, &ndconf.kda_gateway, ip, 357 sizeof(ip))); 358 (void)close(fd); 359 } 360 } 361 362 static int 363 opendumpdev(const char *arg, char *dumpdev) 364 { 365 int fd, i; 366 367 if (strncmp(arg, _PATH_DEV, sizeof(_PATH_DEV) - 1) == 0) 368 strlcpy(dumpdev, arg, PATH_MAX); 369 else { 370 i = snprintf(dumpdev, PATH_MAX, "%s%s", _PATH_DEV, arg); 371 if (i < 0) 372 err(EX_OSERR, "%s", arg); 373 if (i >= PATH_MAX) 374 errc(EX_DATAERR, EINVAL, "%s", arg); 375 } 376 377 fd = open(dumpdev, O_RDONLY); 378 if (fd < 0) 379 err(EX_OSFILE, "%s", dumpdev); 380 return (fd); 381 } 382 383 int 384 main(int argc, char *argv[]) 385 { 386 char dumpdev[PATH_MAX]; 387 struct diocskerneldump_arg ndconf, *kdap; 388 struct addrinfo hints, *res; 389 const char *dev, *pubkeyfile, *server, *client, *gateway; 390 int ch, error, fd, cipher; 391 bool gzip, list, netdump, zstd, insert, rflag; 392 uint8_t ins_idx; 393 394 gzip = list = netdump = zstd = insert = rflag = false; 395 kdap = NULL; 396 pubkeyfile = NULL; 397 server = client = gateway = NULL; 398 ins_idx = KDA_APPEND; 399 cipher = KERNELDUMP_ENC_NONE; 400 401 while ((ch = getopt(argc, argv, "C:c:g:i:k:lrs:vZz")) != -1) 402 switch ((char)ch) { 403 case 'C': 404 if (strcasecmp(optarg, "chacha") == 0 || 405 strcasecmp(optarg, "chacha20") == 0) 406 cipher = KERNELDUMP_ENC_CHACHA20; 407 else if (strcasecmp(optarg, "aes-cbc") == 0 || 408 strcasecmp(optarg, "aes256-cbc") == 0) 409 cipher = KERNELDUMP_ENC_AES_256_CBC; 410 else 411 errx(EX_USAGE, "Unrecognized cipher algorithm " 412 "'%s'", optarg); 413 break; 414 case 'c': 415 client = optarg; 416 break; 417 case 'g': 418 gateway = optarg; 419 break; 420 case 'i': 421 { 422 int i; 423 424 i = atoi(optarg); 425 if (i < 0 || i >= KDA_APPEND - 1) 426 errx(EX_USAGE, 427 "-i index must be between zero and %d.", 428 (int)KDA_APPEND - 2); 429 insert = true; 430 ins_idx = i; 431 } 432 break; 433 case 'k': 434 pubkeyfile = optarg; 435 break; 436 case 'l': 437 list = true; 438 break; 439 case 'r': 440 rflag = true; 441 break; 442 case 's': 443 server = optarg; 444 break; 445 case 'v': 446 verbose = 1; 447 break; 448 case 'Z': 449 zstd = true; 450 break; 451 case 'z': 452 gzip = true; 453 break; 454 default: 455 usage(); 456 } 457 458 if (gzip && zstd) 459 errx(EX_USAGE, "The -z and -Z options are mutually exclusive."); 460 461 if (insert && rflag) 462 errx(EX_USAGE, "The -i and -r options are mutually exclusive."); 463 464 argc -= optind; 465 argv += optind; 466 467 if (list) { 468 listdumpdev(); 469 exit(EX_OK); 470 } 471 472 if (argc != 1) 473 usage(); 474 475 #ifdef HAVE_CRYPTO 476 if (cipher != KERNELDUMP_ENC_NONE && pubkeyfile == NULL) 477 errx(EX_USAGE, "-C option requires a public key file."); 478 #else 479 if (pubkeyfile != NULL) 480 errx(EX_UNAVAILABLE,"Unable to use the public key." 481 " Recompile dumpon with OpenSSL support."); 482 #endif 483 484 if (server != NULL && client != NULL) { 485 dev = _PATH_NETDUMP; 486 netdump = true; 487 } else if (server == NULL && client == NULL && argc > 0) { 488 if (strcmp(argv[0], "off") == 0) { 489 rflag = true; 490 dev = _PATH_DEVNULL; 491 } else 492 dev = argv[0]; 493 netdump = false; 494 } else 495 usage(); 496 497 fd = opendumpdev(dev, dumpdev); 498 if (!netdump && !gzip && !rflag) 499 check_size(fd, dumpdev); 500 501 kdap = &ndconf; 502 bzero(kdap, sizeof(*kdap)); 503 504 if (rflag) 505 kdap->kda_index = KDA_REMOVE; 506 else 507 kdap->kda_index = ins_idx; 508 509 kdap->kda_compression = KERNELDUMP_COMP_NONE; 510 if (zstd) 511 kdap->kda_compression = KERNELDUMP_COMP_ZSTD; 512 else if (gzip) 513 kdap->kda_compression = KERNELDUMP_COMP_GZIP; 514 515 if (netdump) { 516 memset(&hints, 0, sizeof(hints)); 517 hints.ai_family = AF_INET; 518 hints.ai_protocol = IPPROTO_UDP; 519 res = NULL; 520 error = getaddrinfo(server, NULL, &hints, &res); 521 if (error != 0) 522 err(1, "%s", gai_strerror(error)); 523 if (res == NULL) 524 errx(1, "failed to resolve '%s'", server); 525 server = inet_ntoa( 526 ((struct sockaddr_in *)(void *)res->ai_addr)->sin_addr); 527 freeaddrinfo(res); 528 529 if (strlcpy(ndconf.kda_iface, argv[0], 530 sizeof(ndconf.kda_iface)) >= sizeof(ndconf.kda_iface)) 531 errx(EX_USAGE, "invalid interface name '%s'", argv[0]); 532 if (inet_aton(server, &ndconf.kda_server.in4) == 0) 533 errx(EX_USAGE, "invalid server address '%s'", server); 534 if (inet_aton(client, &ndconf.kda_client.in4) == 0) 535 errx(EX_USAGE, "invalid client address '%s'", client); 536 537 if (gateway == NULL) { 538 gateway = find_gateway(argv[0]); 539 if (gateway == NULL) { 540 if (verbose) 541 printf( 542 "failed to look up gateway for %s\n", 543 server); 544 gateway = server; 545 } 546 } 547 if (inet_aton(gateway, &ndconf.kda_gateway.in4) == 0) 548 errx(EX_USAGE, "invalid gateway address '%s'", gateway); 549 ndconf.kda_af = AF_INET; 550 } 551 552 #ifdef HAVE_CRYPTO 553 if (pubkeyfile != NULL) { 554 kdap->kda_encryption = cipher; 555 genkey(pubkeyfile, kdap); 556 } 557 #endif 558 error = ioctl(fd, DIOCSKERNELDUMP, kdap); 559 if (error != 0) 560 error = errno; 561 explicit_bzero(kdap->kda_encryptedkey, kdap->kda_encryptedkeysize); 562 free(kdap->kda_encryptedkey); 563 explicit_bzero(kdap, sizeof(*kdap)); 564 if (error != 0) { 565 if (netdump) { 566 /* 567 * Be slightly less user-hostile for some common 568 * errors, especially as users don't have any great 569 * discoverability into which NICs support netdump. 570 */ 571 if (error == ENXIO) 572 errx(EX_OSERR, "Unable to configure netdump " 573 "because the interface's link is down."); 574 else if (error == ENODEV) 575 errx(EX_OSERR, "Unable to configure netdump " 576 "because the interface driver does not yet " 577 "support netdump."); 578 } 579 errc(EX_OSERR, error, "ioctl(DIOCSKERNELDUMP)"); 580 } 581 582 if (verbose) 583 listdumpdev(); 584 585 exit(EX_OK); 586 } 587