djm@openbsd.org | a5ad3a9 | 2016-09-21 16:55:42 +0000 | [diff] [blame^] | 1 | /* $OpenBSD: addrmatch.c,v 1.13 2016/09/21 16:55:42 djm Exp $ */ |
Darren Tucker | 7a3935d | 2008-06-10 22:59:10 +1000 | [diff] [blame] | 2 | |
| 3 | /* |
| 4 | * Copyright (c) 2004-2008 Damien Miller <djm@mindrot.org> |
| 5 | * |
| 6 | * Permission to use, copy, modify, and distribute this software for any |
| 7 | * purpose with or without fee is hereby granted, provided that the above |
| 8 | * copyright notice and this permission notice appear in all copies. |
| 9 | * |
| 10 | * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES |
| 11 | * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF |
| 12 | * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR |
| 13 | * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES |
| 14 | * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN |
| 15 | * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF |
| 16 | * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. |
| 17 | */ |
| 18 | |
| 19 | #include "includes.h" |
| 20 | |
| 21 | #include <sys/types.h> |
| 22 | #include <sys/socket.h> |
| 23 | #include <netinet/in.h> |
| 24 | #include <arpa/inet.h> |
| 25 | |
| 26 | #include <netdb.h> |
| 27 | #include <string.h> |
| 28 | #include <stdlib.h> |
| 29 | #include <stdio.h> |
| 30 | #include <stdarg.h> |
| 31 | |
| 32 | #include "match.h" |
| 33 | #include "log.h" |
| 34 | |
| 35 | struct xaddr { |
| 36 | sa_family_t af; |
| 37 | union { |
| 38 | struct in_addr v4; |
| 39 | struct in6_addr v6; |
| 40 | u_int8_t addr8[16]; |
| 41 | u_int32_t addr32[4]; |
| 42 | } xa; /* 128-bit address */ |
| 43 | u_int32_t scope_id; /* iface scope id for v6 */ |
| 44 | #define v4 xa.v4 |
| 45 | #define v6 xa.v6 |
| 46 | #define addr8 xa.addr8 |
| 47 | #define addr32 xa.addr32 |
| 48 | }; |
| 49 | |
| 50 | static int |
| 51 | addr_unicast_masklen(int af) |
| 52 | { |
| 53 | switch (af) { |
| 54 | case AF_INET: |
| 55 | return 32; |
| 56 | case AF_INET6: |
| 57 | return 128; |
| 58 | default: |
| 59 | return -1; |
| 60 | } |
| 61 | } |
| 62 | |
| 63 | static inline int |
| 64 | masklen_valid(int af, u_int masklen) |
| 65 | { |
| 66 | switch (af) { |
| 67 | case AF_INET: |
| 68 | return masklen <= 32 ? 0 : -1; |
| 69 | case AF_INET6: |
| 70 | return masklen <= 128 ? 0 : -1; |
| 71 | default: |
| 72 | return -1; |
| 73 | } |
| 74 | } |
| 75 | |
| 76 | /* |
| 77 | * Convert struct sockaddr to struct xaddr |
| 78 | * Returns 0 on success, -1 on failure. |
| 79 | */ |
| 80 | static int |
| 81 | addr_sa_to_xaddr(struct sockaddr *sa, socklen_t slen, struct xaddr *xa) |
| 82 | { |
| 83 | struct sockaddr_in *in4 = (struct sockaddr_in *)sa; |
| 84 | struct sockaddr_in6 *in6 = (struct sockaddr_in6 *)sa; |
| 85 | |
| 86 | memset(xa, '\0', sizeof(*xa)); |
| 87 | |
| 88 | switch (sa->sa_family) { |
| 89 | case AF_INET: |
Darren Tucker | 7eee358 | 2014-01-19 22:37:02 +1100 | [diff] [blame] | 90 | if (slen < (socklen_t)sizeof(*in4)) |
Darren Tucker | 7a3935d | 2008-06-10 22:59:10 +1000 | [diff] [blame] | 91 | return -1; |
| 92 | xa->af = AF_INET; |
| 93 | memcpy(&xa->v4, &in4->sin_addr, sizeof(xa->v4)); |
| 94 | break; |
| 95 | case AF_INET6: |
Darren Tucker | 7eee358 | 2014-01-19 22:37:02 +1100 | [diff] [blame] | 96 | if (slen < (socklen_t)sizeof(*in6)) |
Darren Tucker | 7a3935d | 2008-06-10 22:59:10 +1000 | [diff] [blame] | 97 | return -1; |
| 98 | xa->af = AF_INET6; |
| 99 | memcpy(&xa->v6, &in6->sin6_addr, sizeof(xa->v6)); |
Tim Rice | 0f4d2c0 | 2008-11-18 21:26:41 -0800 | [diff] [blame] | 100 | #ifdef HAVE_STRUCT_SOCKADDR_IN6_SIN6_SCOPE_ID |
Darren Tucker | 7a3935d | 2008-06-10 22:59:10 +1000 | [diff] [blame] | 101 | xa->scope_id = in6->sin6_scope_id; |
Tim Rice | 0f4d2c0 | 2008-11-18 21:26:41 -0800 | [diff] [blame] | 102 | #endif |
Darren Tucker | 7a3935d | 2008-06-10 22:59:10 +1000 | [diff] [blame] | 103 | break; |
| 104 | default: |
| 105 | return -1; |
| 106 | } |
| 107 | |
| 108 | return 0; |
| 109 | } |
| 110 | |
| 111 | /* |
| 112 | * Calculate a netmask of length 'l' for address family 'af' and |
| 113 | * store it in 'n'. |
| 114 | * Returns 0 on success, -1 on failure. |
| 115 | */ |
| 116 | static int |
| 117 | addr_netmask(int af, u_int l, struct xaddr *n) |
| 118 | { |
| 119 | int i; |
| 120 | |
| 121 | if (masklen_valid(af, l) != 0 || n == NULL) |
| 122 | return -1; |
| 123 | |
| 124 | memset(n, '\0', sizeof(*n)); |
| 125 | switch (af) { |
| 126 | case AF_INET: |
| 127 | n->af = AF_INET; |
Damien Miller | 0a80ca1 | 2010-02-27 07:55:05 +1100 | [diff] [blame] | 128 | if (l == 0) |
| 129 | return 0; |
Darren Tucker | 7a3935d | 2008-06-10 22:59:10 +1000 | [diff] [blame] | 130 | n->v4.s_addr = htonl((0xffffffff << (32 - l)) & 0xffffffff); |
| 131 | return 0; |
| 132 | case AF_INET6: |
| 133 | n->af = AF_INET6; |
| 134 | for (i = 0; i < 4 && l >= 32; i++, l -= 32) |
| 135 | n->addr32[i] = 0xffffffffU; |
| 136 | if (i < 4 && l != 0) |
| 137 | n->addr32[i] = htonl((0xffffffff << (32 - l)) & |
| 138 | 0xffffffff); |
| 139 | return 0; |
| 140 | default: |
| 141 | return -1; |
| 142 | } |
| 143 | } |
| 144 | |
| 145 | /* |
| 146 | * Perform logical AND of addresses 'a' and 'b', storing result in 'dst'. |
| 147 | * Returns 0 on success, -1 on failure. |
| 148 | */ |
| 149 | static int |
| 150 | addr_and(struct xaddr *dst, const struct xaddr *a, const struct xaddr *b) |
| 151 | { |
| 152 | int i; |
| 153 | |
| 154 | if (dst == NULL || a == NULL || b == NULL || a->af != b->af) |
| 155 | return -1; |
| 156 | |
| 157 | memcpy(dst, a, sizeof(*dst)); |
| 158 | switch (a->af) { |
| 159 | case AF_INET: |
| 160 | dst->v4.s_addr &= b->v4.s_addr; |
| 161 | return 0; |
| 162 | case AF_INET6: |
| 163 | dst->scope_id = a->scope_id; |
| 164 | for (i = 0; i < 4; i++) |
| 165 | dst->addr32[i] &= b->addr32[i]; |
| 166 | return 0; |
| 167 | default: |
| 168 | return -1; |
| 169 | } |
| 170 | } |
| 171 | |
| 172 | /* |
| 173 | * Compare addresses 'a' and 'b' |
| 174 | * Return 0 if addresses are identical, -1 if (a < b) or 1 if (a > b) |
| 175 | */ |
| 176 | static int |
| 177 | addr_cmp(const struct xaddr *a, const struct xaddr *b) |
| 178 | { |
| 179 | int i; |
| 180 | |
| 181 | if (a->af != b->af) |
| 182 | return a->af == AF_INET6 ? 1 : -1; |
| 183 | |
| 184 | switch (a->af) { |
| 185 | case AF_INET: |
| 186 | if (a->v4.s_addr == b->v4.s_addr) |
| 187 | return 0; |
| 188 | return ntohl(a->v4.s_addr) > ntohl(b->v4.s_addr) ? 1 : -1; |
| 189 | case AF_INET6: |
| 190 | for (i = 0; i < 16; i++) |
| 191 | if (a->addr8[i] - b->addr8[i] != 0) |
| 192 | return a->addr8[i] > b->addr8[i] ? 1 : -1; |
| 193 | if (a->scope_id == b->scope_id) |
| 194 | return 0; |
| 195 | return a->scope_id > b->scope_id ? 1 : -1; |
| 196 | default: |
| 197 | return -1; |
| 198 | } |
| 199 | } |
| 200 | |
| 201 | /* |
| 202 | * Parse string address 'p' into 'n' |
| 203 | * Returns 0 on success, -1 on failure. |
| 204 | */ |
| 205 | static int |
| 206 | addr_pton(const char *p, struct xaddr *n) |
| 207 | { |
| 208 | struct addrinfo hints, *ai; |
| 209 | |
| 210 | memset(&hints, '\0', sizeof(hints)); |
| 211 | hints.ai_flags = AI_NUMERICHOST; |
| 212 | |
| 213 | if (p == NULL || getaddrinfo(p, NULL, &hints, &ai) != 0) |
| 214 | return -1; |
| 215 | |
| 216 | if (ai == NULL || ai->ai_addr == NULL) |
| 217 | return -1; |
| 218 | |
| 219 | if (n != NULL && |
| 220 | addr_sa_to_xaddr(ai->ai_addr, ai->ai_addrlen, n) == -1) { |
| 221 | freeaddrinfo(ai); |
| 222 | return -1; |
| 223 | } |
| 224 | |
| 225 | freeaddrinfo(ai); |
| 226 | return 0; |
| 227 | } |
| 228 | |
| 229 | /* |
| 230 | * Perform bitwise negation of address |
| 231 | * Returns 0 on success, -1 on failure. |
| 232 | */ |
| 233 | static int |
| 234 | addr_invert(struct xaddr *n) |
| 235 | { |
| 236 | int i; |
| 237 | |
| 238 | if (n == NULL) |
| 239 | return (-1); |
| 240 | |
| 241 | switch (n->af) { |
| 242 | case AF_INET: |
| 243 | n->v4.s_addr = ~n->v4.s_addr; |
| 244 | return (0); |
| 245 | case AF_INET6: |
| 246 | for (i = 0; i < 4; i++) |
| 247 | n->addr32[i] = ~n->addr32[i]; |
| 248 | return (0); |
| 249 | default: |
| 250 | return (-1); |
| 251 | } |
| 252 | } |
| 253 | |
| 254 | /* |
| 255 | * Calculate a netmask of length 'l' for address family 'af' and |
| 256 | * store it in 'n'. |
| 257 | * Returns 0 on success, -1 on failure. |
| 258 | */ |
| 259 | static int |
| 260 | addr_hostmask(int af, u_int l, struct xaddr *n) |
| 261 | { |
| 262 | if (addr_netmask(af, l, n) == -1 || addr_invert(n) == -1) |
| 263 | return (-1); |
| 264 | return (0); |
| 265 | } |
| 266 | |
| 267 | /* |
| 268 | * Test whether address 'a' is all zeros (i.e. 0.0.0.0 or ::) |
| 269 | * Returns 0 on if address is all-zeros, -1 if not all zeros or on failure. |
| 270 | */ |
| 271 | static int |
| 272 | addr_is_all0s(const struct xaddr *a) |
| 273 | { |
| 274 | int i; |
| 275 | |
| 276 | switch (a->af) { |
| 277 | case AF_INET: |
| 278 | return (a->v4.s_addr == 0 ? 0 : -1); |
| 279 | case AF_INET6:; |
| 280 | for (i = 0; i < 4; i++) |
| 281 | if (a->addr32[i] != 0) |
| 282 | return (-1); |
| 283 | return (0); |
| 284 | default: |
| 285 | return (-1); |
| 286 | } |
| 287 | } |
| 288 | |
| 289 | /* |
| 290 | * Test whether host portion of address 'a', as determined by 'masklen' |
| 291 | * is all zeros. |
| 292 | * Returns 0 on if host portion of address is all-zeros, |
| 293 | * -1 if not all zeros or on failure. |
| 294 | */ |
| 295 | static int |
| 296 | addr_host_is_all0s(const struct xaddr *a, u_int masklen) |
| 297 | { |
| 298 | struct xaddr tmp_addr, tmp_mask, tmp_result; |
| 299 | |
| 300 | memcpy(&tmp_addr, a, sizeof(tmp_addr)); |
| 301 | if (addr_hostmask(a->af, masklen, &tmp_mask) == -1) |
| 302 | return (-1); |
| 303 | if (addr_and(&tmp_result, &tmp_addr, &tmp_mask) == -1) |
| 304 | return (-1); |
| 305 | return (addr_is_all0s(&tmp_result)); |
| 306 | } |
| 307 | |
| 308 | /* |
| 309 | * Parse a CIDR address (x.x.x.x/y or xxxx:yyyy::/z). |
| 310 | * Return -1 on parse error, -2 on inconsistency or 0 on success. |
| 311 | */ |
| 312 | static int |
| 313 | addr_pton_cidr(const char *p, struct xaddr *n, u_int *l) |
| 314 | { |
| 315 | struct xaddr tmp; |
| 316 | long unsigned int masklen = 999; |
| 317 | char addrbuf[64], *mp, *cp; |
| 318 | |
| 319 | /* Don't modify argument */ |
Damien Miller | 97f43bb | 2012-06-30 08:32:29 +1000 | [diff] [blame] | 320 | if (p == NULL || strlcpy(addrbuf, p, sizeof(addrbuf)) >= sizeof(addrbuf)) |
Darren Tucker | 7a3935d | 2008-06-10 22:59:10 +1000 | [diff] [blame] | 321 | return -1; |
| 322 | |
| 323 | if ((mp = strchr(addrbuf, '/')) != NULL) { |
| 324 | *mp = '\0'; |
| 325 | mp++; |
| 326 | masklen = strtoul(mp, &cp, 10); |
| 327 | if (*mp == '\0' || *cp != '\0' || masklen > 128) |
| 328 | return -1; |
| 329 | } |
| 330 | |
| 331 | if (addr_pton(addrbuf, &tmp) == -1) |
| 332 | return -1; |
| 333 | |
| 334 | if (mp == NULL) |
| 335 | masklen = addr_unicast_masklen(tmp.af); |
| 336 | if (masklen_valid(tmp.af, masklen) == -1) |
| 337 | return -2; |
| 338 | if (addr_host_is_all0s(&tmp, masklen) != 0) |
| 339 | return -2; |
| 340 | |
| 341 | if (n != NULL) |
| 342 | memcpy(n, &tmp, sizeof(*n)); |
| 343 | if (l != NULL) |
| 344 | *l = masklen; |
| 345 | |
| 346 | return 0; |
| 347 | } |
| 348 | |
| 349 | static int |
| 350 | addr_netmatch(const struct xaddr *host, const struct xaddr *net, u_int masklen) |
| 351 | { |
| 352 | struct xaddr tmp_mask, tmp_result; |
| 353 | |
| 354 | if (host->af != net->af) |
| 355 | return -1; |
| 356 | |
| 357 | if (addr_netmask(host->af, masklen, &tmp_mask) == -1) |
| 358 | return -1; |
| 359 | if (addr_and(&tmp_result, host, &tmp_mask) == -1) |
| 360 | return -1; |
| 361 | return addr_cmp(&tmp_result, net); |
| 362 | } |
| 363 | |
| 364 | /* |
| 365 | * Match "addr" against list pattern list "_list", which may contain a |
| 366 | * mix of CIDR addresses and old-school wildcards. |
| 367 | * |
| 368 | * If addr is NULL, then no matching is performed, but _list is parsed |
| 369 | * and checked for well-formedness. |
| 370 | * |
| 371 | * Returns 1 on match found (never returned when addr == NULL). |
| 372 | * Returns 0 on if no match found, or no errors found when addr == NULL. |
Darren Tucker | 896ad5a | 2008-06-11 09:34:46 +1000 | [diff] [blame] | 373 | * Returns -1 on negated match found (never returned when addr == NULL). |
| 374 | * Returns -2 on invalid list entry. |
Darren Tucker | 7a3935d | 2008-06-10 22:59:10 +1000 | [diff] [blame] | 375 | */ |
| 376 | int |
| 377 | addr_match_list(const char *addr, const char *_list) |
| 378 | { |
| 379 | char *list, *cp, *o; |
| 380 | struct xaddr try_addr, match_addr; |
| 381 | u_int masklen, neg; |
| 382 | int ret = 0, r; |
| 383 | |
| 384 | if (addr != NULL && addr_pton(addr, &try_addr) != 0) { |
| 385 | debug2("%s: couldn't parse address %.100s", __func__, addr); |
| 386 | return 0; |
| 387 | } |
| 388 | if ((o = list = strdup(_list)) == NULL) |
| 389 | return -1; |
| 390 | while ((cp = strsep(&list, ",")) != NULL) { |
| 391 | neg = *cp == '!'; |
| 392 | if (neg) |
| 393 | cp++; |
| 394 | if (*cp == '\0') { |
Darren Tucker | 896ad5a | 2008-06-11 09:34:46 +1000 | [diff] [blame] | 395 | ret = -2; |
Darren Tucker | 7a3935d | 2008-06-10 22:59:10 +1000 | [diff] [blame] | 396 | break; |
| 397 | } |
| 398 | /* Prefer CIDR address matching */ |
| 399 | r = addr_pton_cidr(cp, &match_addr, &masklen); |
| 400 | if (r == -2) { |
djm@openbsd.org | 23555eb | 2016-08-23 08:17:42 +0000 | [diff] [blame] | 401 | debug2("%s: inconsistent mask length for " |
| 402 | "match network \"%.100s\"", __func__, cp); |
Darren Tucker | 896ad5a | 2008-06-11 09:34:46 +1000 | [diff] [blame] | 403 | ret = -2; |
Darren Tucker | 7a3935d | 2008-06-10 22:59:10 +1000 | [diff] [blame] | 404 | break; |
| 405 | } else if (r == 0) { |
| 406 | if (addr != NULL && addr_netmatch(&try_addr, |
| 407 | &match_addr, masklen) == 0) { |
| 408 | foundit: |
| 409 | if (neg) { |
Darren Tucker | 896ad5a | 2008-06-11 09:34:46 +1000 | [diff] [blame] | 410 | ret = -1; |
Darren Tucker | 7a3935d | 2008-06-10 22:59:10 +1000 | [diff] [blame] | 411 | break; |
| 412 | } |
| 413 | ret = 1; |
djm@openbsd.org | a5ad3a9 | 2016-09-21 16:55:42 +0000 | [diff] [blame^] | 414 | } |
Darren Tucker | 7a3935d | 2008-06-10 22:59:10 +1000 | [diff] [blame] | 415 | continue; |
| 416 | } else { |
| 417 | /* If CIDR parse failed, try wildcard string match */ |
| 418 | if (addr != NULL && match_pattern(addr, cp) == 1) |
| 419 | goto foundit; |
| 420 | } |
| 421 | } |
Darren Tucker | a627d42 | 2013-06-02 07:31:17 +1000 | [diff] [blame] | 422 | free(o); |
Darren Tucker | 7a3935d | 2008-06-10 22:59:10 +1000 | [diff] [blame] | 423 | |
| 424 | return ret; |
| 425 | } |
Damien Miller | 0a80ca1 | 2010-02-27 07:55:05 +1100 | [diff] [blame] | 426 | |
| 427 | /* |
| 428 | * Match "addr" against list CIDR list "_list". Lexical wildcards and |
| 429 | * negation are not supported. If "addr" == NULL, will verify structure |
| 430 | * of "_list". |
| 431 | * |
| 432 | * Returns 1 on match found (never returned when addr == NULL). |
| 433 | * Returns 0 on if no match found, or no errors found when addr == NULL. |
| 434 | * Returns -1 on error |
| 435 | */ |
| 436 | int |
| 437 | addr_match_cidr_list(const char *addr, const char *_list) |
| 438 | { |
| 439 | char *list, *cp, *o; |
| 440 | struct xaddr try_addr, match_addr; |
| 441 | u_int masklen; |
| 442 | int ret = 0, r; |
| 443 | |
| 444 | if (addr != NULL && addr_pton(addr, &try_addr) != 0) { |
| 445 | debug2("%s: couldn't parse address %.100s", __func__, addr); |
| 446 | return 0; |
| 447 | } |
| 448 | if ((o = list = strdup(_list)) == NULL) |
| 449 | return -1; |
| 450 | while ((cp = strsep(&list, ",")) != NULL) { |
| 451 | if (*cp == '\0') { |
| 452 | error("%s: empty entry in list \"%.100s\"", |
| 453 | __func__, o); |
| 454 | ret = -1; |
| 455 | break; |
| 456 | } |
| 457 | |
| 458 | /* |
| 459 | * NB. This function is called in pre-auth with untrusted data, |
| 460 | * so be extra paranoid about junk reaching getaddrino (via |
| 461 | * addr_pton_cidr). |
| 462 | */ |
| 463 | |
| 464 | /* Stop junk from reaching getaddrinfo. +3 is for masklen */ |
| 465 | if (strlen(cp) > INET6_ADDRSTRLEN + 3) { |
| 466 | error("%s: list entry \"%.100s\" too long", |
| 467 | __func__, cp); |
| 468 | ret = -1; |
| 469 | break; |
| 470 | } |
| 471 | #define VALID_CIDR_CHARS "0123456789abcdefABCDEF.:/" |
| 472 | if (strspn(cp, VALID_CIDR_CHARS) != strlen(cp)) { |
| 473 | error("%s: list entry \"%.100s\" contains invalid " |
| 474 | "characters", __func__, cp); |
| 475 | ret = -1; |
| 476 | } |
| 477 | |
| 478 | /* Prefer CIDR address matching */ |
| 479 | r = addr_pton_cidr(cp, &match_addr, &masklen); |
| 480 | if (r == -1) { |
| 481 | error("Invalid network entry \"%.100s\"", cp); |
| 482 | ret = -1; |
| 483 | break; |
| 484 | } else if (r == -2) { |
| 485 | error("Inconsistent mask length for " |
| 486 | "network \"%.100s\"", cp); |
| 487 | ret = -1; |
| 488 | break; |
| 489 | } else if (r == 0 && addr != NULL) { |
| 490 | if (addr_netmatch(&try_addr, &match_addr, |
| 491 | masklen) == 0) |
| 492 | ret = 1; |
| 493 | continue; |
| 494 | } |
| 495 | } |
Darren Tucker | a627d42 | 2013-06-02 07:31:17 +1000 | [diff] [blame] | 496 | free(o); |
Damien Miller | 0a80ca1 | 2010-02-27 07:55:05 +1100 | [diff] [blame] | 497 | |
| 498 | return ret; |
| 499 | } |