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 [-v] [-k <pubkey>] [-Zz] <device>\n" 90 " dumpon [-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 kdap->kda_encryption = KERNELDUMP_ENC_AES_256_CBC; 280 arc4random_buf(kdap->kda_key, sizeof(kdap->kda_key)); 281 if (RSA_public_encrypt(sizeof(kdap->kda_key), kdap->kda_key, 282 kdap->kda_encryptedkey, pubkey, 283 RSA_PKCS1_PADDING) != (int)kdap->kda_encryptedkeysize) { 284 errx(1, "Unable to encrypt the one-time key."); 285 } 286 RSA_free(pubkey); 287 } 288 #endif 289 290 static void 291 listdumpdev(void) 292 { 293 char dumpdev[PATH_MAX]; 294 struct netdump_conf ndconf; 295 size_t len; 296 const char *sysctlname = "kern.shutdown.dumpdevname"; 297 int fd; 298 299 len = sizeof(dumpdev); 300 if (sysctlbyname(sysctlname, &dumpdev, &len, NULL, 0) != 0) { 301 if (errno == ENOMEM) { 302 err(EX_OSERR, "Kernel returned too large of a buffer for '%s'\n", 303 sysctlname); 304 } else { 305 err(EX_OSERR, "Sysctl get '%s'\n", sysctlname); 306 } 307 } 308 if (strlen(dumpdev) == 0) 309 (void)strlcpy(dumpdev, _PATH_DEVNULL, sizeof(dumpdev)); 310 311 if (verbose) 312 printf("kernel dumps on "); 313 printf("%s\n", dumpdev); 314 315 /* If netdump is enabled, print the configuration parameters. */ 316 if (verbose) { 317 fd = open(_PATH_NETDUMP, O_RDONLY); 318 if (fd < 0) { 319 if (errno != ENOENT) 320 err(EX_OSERR, "opening %s", _PATH_NETDUMP); 321 return; 322 } 323 if (ioctl(fd, NETDUMPGCONF, &ndconf) != 0) { 324 if (errno != ENXIO) 325 err(EX_OSERR, "ioctl(NETDUMPGCONF)"); 326 (void)close(fd); 327 return; 328 } 329 330 printf("server address: %s\n", inet_ntoa(ndconf.ndc_server)); 331 printf("client address: %s\n", inet_ntoa(ndconf.ndc_client)); 332 printf("gateway address: %s\n", inet_ntoa(ndconf.ndc_gateway)); 333 (void)close(fd); 334 } 335 } 336 337 static int 338 opendumpdev(const char *arg, char *dumpdev) 339 { 340 int fd, i; 341 342 if (strncmp(arg, _PATH_DEV, sizeof(_PATH_DEV) - 1) == 0) 343 strlcpy(dumpdev, arg, PATH_MAX); 344 else { 345 i = snprintf(dumpdev, PATH_MAX, "%s%s", _PATH_DEV, arg); 346 if (i < 0) 347 err(EX_OSERR, "%s", arg); 348 if (i >= PATH_MAX) 349 errc(EX_DATAERR, EINVAL, "%s", arg); 350 } 351 352 fd = open(dumpdev, O_RDONLY); 353 if (fd < 0) 354 err(EX_OSFILE, "%s", dumpdev); 355 return (fd); 356 } 357 358 int 359 main(int argc, char *argv[]) 360 { 361 char dumpdev[PATH_MAX]; 362 struct diocskerneldump_arg _kda, *kdap; 363 struct netdump_conf ndconf; 364 struct addrinfo hints, *res; 365 const char *dev, *pubkeyfile, *server, *client, *gateway; 366 int ch, error, fd; 367 bool enable, gzip, list, netdump, zstd; 368 369 gzip = list = netdump = zstd = false; 370 kdap = NULL; 371 pubkeyfile = NULL; 372 server = client = gateway = NULL; 373 374 while ((ch = getopt(argc, argv, "c:g:k:ls:vZz")) != -1) 375 switch ((char)ch) { 376 case 'c': 377 client = optarg; 378 break; 379 case 'g': 380 gateway = optarg; 381 break; 382 case 'k': 383 pubkeyfile = optarg; 384 break; 385 case 'l': 386 list = true; 387 break; 388 case 's': 389 server = optarg; 390 break; 391 case 'v': 392 verbose = 1; 393 break; 394 case 'Z': 395 zstd = true; 396 break; 397 case 'z': 398 gzip = true; 399 break; 400 default: 401 usage(); 402 } 403 404 if (gzip && zstd) 405 errx(EX_USAGE, "The -z and -Z options are mutually exclusive."); 406 407 argc -= optind; 408 argv += optind; 409 410 if (list) { 411 listdumpdev(); 412 exit(EX_OK); 413 } 414 415 if (argc != 1) 416 usage(); 417 418 #ifndef HAVE_CRYPTO 419 if (pubkeyfile != NULL) 420 errx(EX_UNAVAILABLE,"Unable to use the public key." 421 " Recompile dumpon with OpenSSL support."); 422 #endif 423 424 if (server != NULL && client != NULL) { 425 enable = true; 426 dev = _PATH_NETDUMP; 427 netdump = true; 428 kdap = &ndconf.ndc_kda; 429 } else if (server == NULL && client == NULL && argc > 0) { 430 enable = strcmp(argv[0], "off") != 0; 431 dev = enable ? argv[0] : _PATH_DEVNULL; 432 netdump = false; 433 kdap = &_kda; 434 } else 435 usage(); 436 437 fd = opendumpdev(dev, dumpdev); 438 if (!netdump && !gzip) 439 check_size(fd, dumpdev); 440 441 bzero(kdap, sizeof(*kdap)); 442 kdap->kda_enable = 0; 443 if (ioctl(fd, DIOCSKERNELDUMP, kdap) != 0) 444 err(EX_OSERR, "ioctl(DIOCSKERNELDUMP)"); 445 if (!enable) 446 exit(EX_OK); 447 448 explicit_bzero(kdap, sizeof(*kdap)); 449 kdap->kda_enable = 1; 450 kdap->kda_compression = KERNELDUMP_COMP_NONE; 451 if (zstd) 452 kdap->kda_compression = KERNELDUMP_COMP_ZSTD; 453 else if (gzip) 454 kdap->kda_compression = KERNELDUMP_COMP_GZIP; 455 456 if (netdump) { 457 memset(&hints, 0, sizeof(hints)); 458 hints.ai_family = AF_INET; 459 hints.ai_protocol = IPPROTO_UDP; 460 res = NULL; 461 error = getaddrinfo(server, NULL, &hints, &res); 462 if (error != 0) 463 err(1, "%s", gai_strerror(error)); 464 if (res == NULL) 465 errx(1, "failed to resolve '%s'", server); 466 server = inet_ntoa( 467 ((struct sockaddr_in *)(void *)res->ai_addr)->sin_addr); 468 freeaddrinfo(res); 469 470 if (strlcpy(ndconf.ndc_iface, argv[0], 471 sizeof(ndconf.ndc_iface)) >= sizeof(ndconf.ndc_iface)) 472 errx(EX_USAGE, "invalid interface name '%s'", argv[0]); 473 if (inet_aton(server, &ndconf.ndc_server) == 0) 474 errx(EX_USAGE, "invalid server address '%s'", server); 475 if (inet_aton(client, &ndconf.ndc_client) == 0) 476 errx(EX_USAGE, "invalid client address '%s'", client); 477 478 if (gateway == NULL) { 479 gateway = find_gateway(argv[0]); 480 if (gateway == NULL) { 481 if (verbose) 482 printf( 483 "failed to look up gateway for %s\n", 484 server); 485 gateway = server; 486 } 487 } 488 if (inet_aton(gateway, &ndconf.ndc_gateway) == 0) 489 errx(EX_USAGE, "invalid gateway address '%s'", gateway); 490 491 #ifdef HAVE_CRYPTO 492 if (pubkeyfile != NULL) 493 genkey(pubkeyfile, kdap); 494 #endif 495 error = ioctl(fd, NETDUMPSCONF, &ndconf); 496 if (error != 0) 497 error = errno; 498 explicit_bzero(kdap->kda_encryptedkey, 499 kdap->kda_encryptedkeysize); 500 free(kdap->kda_encryptedkey); 501 explicit_bzero(kdap, sizeof(*kdap)); 502 if (error != 0) 503 errc(EX_OSERR, error, "ioctl(NETDUMPSCONF)"); 504 } else { 505 #ifdef HAVE_CRYPTO 506 if (pubkeyfile != NULL) 507 genkey(pubkeyfile, kdap); 508 #endif 509 error = ioctl(fd, DIOCSKERNELDUMP, kdap); 510 if (error != 0) 511 error = errno; 512 explicit_bzero(kdap->kda_encryptedkey, 513 kdap->kda_encryptedkeysize); 514 free(kdap->kda_encryptedkey); 515 explicit_bzero(kdap, sizeof(*kdap)); 516 if (error != 0) 517 errc(EX_OSERR, error, "ioctl(DIOCSKERNELDUMP)"); 518 } 519 if (verbose) 520 printf("kernel dumps on %s\n", dumpdev); 521 522 exit(EX_OK); 523 } 524