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 errx(EX_IOERR, "%s is smaller than physical memory", fn); 208 } 209 210 #ifdef HAVE_CRYPTO 211 static void 212 genkey(const char *pubkeyfile, struct diocskerneldump_arg *kdap) 213 { 214 FILE *fp; 215 RSA *pubkey; 216 217 assert(pubkeyfile != NULL); 218 assert(kdap != NULL); 219 220 fp = NULL; 221 pubkey = NULL; 222 223 fp = fopen(pubkeyfile, "r"); 224 if (fp == NULL) 225 err(1, "Unable to open %s", pubkeyfile); 226 227 if (caph_enter() < 0) 228 err(1, "Unable to enter capability mode"); 229 230 pubkey = RSA_new(); 231 if (pubkey == NULL) { 232 errx(1, "Unable to allocate an RSA structure: %s", 233 ERR_error_string(ERR_get_error(), NULL)); 234 } 235 236 pubkey = PEM_read_RSA_PUBKEY(fp, &pubkey, NULL, NULL); 237 fclose(fp); 238 fp = NULL; 239 if (pubkey == NULL) 240 errx(1, "Unable to read data from %s.", pubkeyfile); 241 242 /* 243 * RSA keys under ~1024 bits are trivially factorable (2018). OpenSSL 244 * provides an API for RSA keys to estimate the symmetric-cipher 245 * "equivalent" bits of security (defined in NIST SP800-57), which as 246 * of this writing equates a 2048-bit RSA key to 112 symmetric cipher 247 * bits. 248 * 249 * Use this API as a seatbelt to avoid suggesting to users that their 250 * privacy is protected by encryption when the key size is insufficient 251 * to prevent compromise via factoring. 252 * 253 * Future work: Sanity check for weak 'e', and sanity check for absence 254 * of 'd' (i.e., the supplied key is a public key rather than a full 255 * keypair). 256 */ 257 #if OPENSSL_VERSION_NUMBER >= 0x10100000L 258 if (RSA_security_bits(pubkey) < 112) 259 #else 260 if (RSA_size(pubkey) * 8 < 2048) 261 #endif 262 errx(1, "Small RSA keys (you provided: %db) can be " 263 "factored cheaply. Please generate a larger key.", 264 RSA_size(pubkey) * 8); 265 266 kdap->kda_encryptedkeysize = RSA_size(pubkey); 267 if (kdap->kda_encryptedkeysize > KERNELDUMP_ENCKEY_MAX_SIZE) { 268 errx(1, "Public key has to be at most %db long.", 269 8 * KERNELDUMP_ENCKEY_MAX_SIZE); 270 } 271 272 kdap->kda_encryptedkey = calloc(1, kdap->kda_encryptedkeysize); 273 if (kdap->kda_encryptedkey == NULL) 274 err(1, "Unable to allocate encrypted key"); 275 276 /* 277 * If no cipher was specified, choose a reasonable default. 278 */ 279 if (kdap->kda_encryption == KERNELDUMP_ENC_NONE) 280 kdap->kda_encryption = KERNELDUMP_ENC_CHACHA20; 281 else if (kdap->kda_encryption == KERNELDUMP_ENC_AES_256_CBC && 282 kdap->kda_compression != KERNELDUMP_COMP_NONE) 283 errx(EX_USAGE, "Unpadded AES256-CBC mode cannot be used " 284 "with compression."); 285 286 arc4random_buf(kdap->kda_key, sizeof(kdap->kda_key)); 287 if (RSA_public_encrypt(sizeof(kdap->kda_key), kdap->kda_key, 288 kdap->kda_encryptedkey, pubkey, 289 RSA_PKCS1_PADDING) != (int)kdap->kda_encryptedkeysize) { 290 errx(1, "Unable to encrypt the one-time key."); 291 } 292 RSA_free(pubkey); 293 } 294 #endif 295 296 static void 297 listdumpdev(void) 298 { 299 static char ip[200]; 300 301 char dumpdev[PATH_MAX]; 302 struct diocskerneldump_arg ndconf; 303 size_t len; 304 const char *sysctlname = "kern.shutdown.dumpdevname"; 305 int fd; 306 307 len = sizeof(dumpdev); 308 if (sysctlbyname(sysctlname, &dumpdev, &len, NULL, 0) != 0) { 309 if (errno == ENOMEM) { 310 err(EX_OSERR, "Kernel returned too large of a buffer for '%s'\n", 311 sysctlname); 312 } else { 313 err(EX_OSERR, "Sysctl get '%s'\n", sysctlname); 314 } 315 } 316 if (strlen(dumpdev) == 0) 317 (void)strlcpy(dumpdev, _PATH_DEVNULL, sizeof(dumpdev)); 318 319 if (verbose) { 320 char *ctx, *dd; 321 unsigned idx; 322 323 printf("kernel dumps on priority: device\n"); 324 idx = 0; 325 ctx = dumpdev; 326 while ((dd = strsep(&ctx, ",")) != NULL) 327 printf("%u: %s\n", idx++, dd); 328 } else 329 printf("%s\n", dumpdev); 330 331 /* If netdump is enabled, print the configuration parameters. */ 332 if (verbose) { 333 fd = open(_PATH_NETDUMP, O_RDONLY); 334 if (fd < 0) { 335 if (errno != ENOENT) 336 err(EX_OSERR, "opening %s", _PATH_NETDUMP); 337 return; 338 } 339 if (ioctl(fd, DIOCGKERNELDUMP, &ndconf) != 0) { 340 if (errno != ENXIO) 341 err(EX_OSERR, "ioctl(DIOCGKERNELDUMP)"); 342 (void)close(fd); 343 return; 344 } 345 346 printf("server address: %s\n", 347 inet_ntop(ndconf.kda_af, &ndconf.kda_server, ip, 348 sizeof(ip))); 349 printf("client address: %s\n", 350 inet_ntop(ndconf.kda_af, &ndconf.kda_client, ip, 351 sizeof(ip))); 352 printf("gateway address: %s\n", 353 inet_ntop(ndconf.kda_af, &ndconf.kda_gateway, ip, 354 sizeof(ip))); 355 (void)close(fd); 356 } 357 } 358 359 static int 360 opendumpdev(const char *arg, char *dumpdev) 361 { 362 int fd, i; 363 364 if (strncmp(arg, _PATH_DEV, sizeof(_PATH_DEV) - 1) == 0) 365 strlcpy(dumpdev, arg, PATH_MAX); 366 else { 367 i = snprintf(dumpdev, PATH_MAX, "%s%s", _PATH_DEV, arg); 368 if (i < 0) 369 err(EX_OSERR, "%s", arg); 370 if (i >= PATH_MAX) 371 errc(EX_DATAERR, EINVAL, "%s", arg); 372 } 373 374 fd = open(dumpdev, O_RDONLY); 375 if (fd < 0) 376 err(EX_OSFILE, "%s", dumpdev); 377 return (fd); 378 } 379 380 int 381 main(int argc, char *argv[]) 382 { 383 char dumpdev[PATH_MAX]; 384 struct diocskerneldump_arg ndconf, *kdap; 385 struct addrinfo hints, *res; 386 const char *dev, *pubkeyfile, *server, *client, *gateway; 387 int ch, error, fd, cipher; 388 bool gzip, list, netdump, zstd, insert, rflag; 389 uint8_t ins_idx; 390 391 gzip = list = netdump = zstd = insert = rflag = false; 392 kdap = NULL; 393 pubkeyfile = NULL; 394 server = client = gateway = NULL; 395 ins_idx = KDA_APPEND; 396 cipher = KERNELDUMP_ENC_NONE; 397 398 while ((ch = getopt(argc, argv, "C:c:g:i:k:lrs:vZz")) != -1) 399 switch ((char)ch) { 400 case 'C': 401 if (strcasecmp(optarg, "chacha") == 0 || 402 strcasecmp(optarg, "chacha20") == 0) 403 cipher = KERNELDUMP_ENC_CHACHA20; 404 else if (strcasecmp(optarg, "aes-cbc") == 0 || 405 strcasecmp(optarg, "aes256-cbc") == 0) 406 cipher = KERNELDUMP_ENC_AES_256_CBC; 407 else 408 errx(EX_USAGE, "Unrecognized cipher algorithm " 409 "'%s'", optarg); 410 break; 411 case 'c': 412 client = optarg; 413 break; 414 case 'g': 415 gateway = optarg; 416 break; 417 case 'i': 418 { 419 int i; 420 421 i = atoi(optarg); 422 if (i < 0 || i >= KDA_APPEND - 1) 423 errx(EX_USAGE, 424 "-i index must be between zero and %d.", 425 (int)KDA_APPEND - 2); 426 insert = true; 427 ins_idx = i; 428 } 429 break; 430 case 'k': 431 pubkeyfile = optarg; 432 break; 433 case 'l': 434 list = true; 435 break; 436 case 'r': 437 rflag = true; 438 break; 439 case 's': 440 server = optarg; 441 break; 442 case 'v': 443 verbose = 1; 444 break; 445 case 'Z': 446 zstd = true; 447 break; 448 case 'z': 449 gzip = true; 450 break; 451 default: 452 usage(); 453 } 454 455 if (gzip && zstd) 456 errx(EX_USAGE, "The -z and -Z options are mutually exclusive."); 457 458 if (insert && rflag) 459 errx(EX_USAGE, "The -i and -r options are mutually exclusive."); 460 461 argc -= optind; 462 argv += optind; 463 464 if (list) { 465 listdumpdev(); 466 exit(EX_OK); 467 } 468 469 if (argc != 1) 470 usage(); 471 472 #ifdef HAVE_CRYPTO 473 if (cipher != KERNELDUMP_ENC_NONE && pubkeyfile == NULL) 474 errx(EX_USAGE, "-C option requires a public key file."); 475 #else 476 if (pubkeyfile != NULL) 477 errx(EX_UNAVAILABLE,"Unable to use the public key." 478 " Recompile dumpon with OpenSSL support."); 479 #endif 480 481 if (server != NULL && client != NULL) { 482 dev = _PATH_NETDUMP; 483 netdump = true; 484 } else if (server == NULL && client == NULL && argc > 0) { 485 if (strcmp(argv[0], "off") == 0) { 486 rflag = true; 487 dev = _PATH_DEVNULL; 488 } else 489 dev = argv[0]; 490 netdump = false; 491 } else 492 usage(); 493 494 fd = opendumpdev(dev, dumpdev); 495 if (!netdump && !gzip && !zstd && !rflag) 496 check_size(fd, dumpdev); 497 498 kdap = &ndconf; 499 bzero(kdap, sizeof(*kdap)); 500 501 if (rflag) 502 kdap->kda_index = KDA_REMOVE; 503 else 504 kdap->kda_index = ins_idx; 505 506 kdap->kda_compression = KERNELDUMP_COMP_NONE; 507 if (zstd) 508 kdap->kda_compression = KERNELDUMP_COMP_ZSTD; 509 else if (gzip) 510 kdap->kda_compression = KERNELDUMP_COMP_GZIP; 511 512 if (netdump) { 513 memset(&hints, 0, sizeof(hints)); 514 hints.ai_family = AF_INET; 515 hints.ai_protocol = IPPROTO_UDP; 516 res = NULL; 517 error = getaddrinfo(server, NULL, &hints, &res); 518 if (error != 0) 519 err(1, "%s", gai_strerror(error)); 520 if (res == NULL) 521 errx(1, "failed to resolve '%s'", server); 522 server = inet_ntoa( 523 ((struct sockaddr_in *)(void *)res->ai_addr)->sin_addr); 524 freeaddrinfo(res); 525 526 if (strlcpy(ndconf.kda_iface, argv[0], 527 sizeof(ndconf.kda_iface)) >= sizeof(ndconf.kda_iface)) 528 errx(EX_USAGE, "invalid interface name '%s'", argv[0]); 529 if (inet_aton(server, &ndconf.kda_server.in4) == 0) 530 errx(EX_USAGE, "invalid server address '%s'", server); 531 if (inet_aton(client, &ndconf.kda_client.in4) == 0) 532 errx(EX_USAGE, "invalid client address '%s'", client); 533 534 if (gateway == NULL) { 535 gateway = find_gateway(argv[0]); 536 if (gateway == NULL) { 537 if (verbose) 538 printf( 539 "failed to look up gateway for %s\n", 540 server); 541 gateway = server; 542 } 543 } 544 if (inet_aton(gateway, &ndconf.kda_gateway.in4) == 0) 545 errx(EX_USAGE, "invalid gateway address '%s'", gateway); 546 ndconf.kda_af = AF_INET; 547 } 548 549 #ifdef HAVE_CRYPTO 550 if (pubkeyfile != NULL) { 551 kdap->kda_encryption = cipher; 552 genkey(pubkeyfile, kdap); 553 } 554 #endif 555 error = ioctl(fd, DIOCSKERNELDUMP, kdap); 556 if (error != 0) 557 error = errno; 558 explicit_bzero(kdap->kda_encryptedkey, kdap->kda_encryptedkeysize); 559 free(kdap->kda_encryptedkey); 560 explicit_bzero(kdap, sizeof(*kdap)); 561 if (error != 0) { 562 if (netdump) { 563 /* 564 * Be slightly less user-hostile for some common 565 * errors, especially as users don't have any great 566 * discoverability into which NICs support netdump. 567 */ 568 if (error == ENXIO) 569 errx(EX_OSERR, "Unable to configure netdump " 570 "because the interface's link is down."); 571 else if (error == ENODEV) 572 errx(EX_OSERR, "Unable to configure netdump " 573 "because the interface driver does not yet " 574 "support netdump."); 575 } 576 errc(EX_OSERR, error, "ioctl(DIOCSKERNELDUMP)"); 577 } 578 579 if (verbose) 580 listdumpdev(); 581 582 exit(EX_OK); 583 } 584