1 /* $OpenBSD: addr.c,v 1.4 2021/10/22 10:51:57 dtucker Exp $ */ 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 31 #include "addr.h" 32 33 #define _SA(x) ((struct sockaddr *)(x)) 34 35 int 36 addr_unicast_masklen(int af) 37 { 38 switch (af) { 39 case AF_INET: 40 return 32; 41 case AF_INET6: 42 return 128; 43 default: 44 return -1; 45 } 46 } 47 48 static inline int 49 masklen_valid(int af, u_int masklen) 50 { 51 switch (af) { 52 case AF_INET: 53 return masklen <= 32 ? 0 : -1; 54 case AF_INET6: 55 return masklen <= 128 ? 0 : -1; 56 default: 57 return -1; 58 } 59 } 60 61 int 62 addr_xaddr_to_sa(const struct xaddr *xa, struct sockaddr *sa, socklen_t *len, 63 u_int16_t port) 64 { 65 struct sockaddr_in *in4 = (struct sockaddr_in *)sa; 66 struct sockaddr_in6 *in6 = (struct sockaddr_in6 *)sa; 67 68 if (xa == NULL || sa == NULL || len == NULL) 69 return -1; 70 71 switch (xa->af) { 72 case AF_INET: 73 if (*len < sizeof(*in4)) 74 return -1; 75 memset(sa, '\0', sizeof(*in4)); 76 *len = sizeof(*in4); 77 #ifdef SOCK_HAS_LEN 78 in4->sin_len = sizeof(*in4); 79 #endif 80 in4->sin_family = AF_INET; 81 in4->sin_port = htons(port); 82 memcpy(&in4->sin_addr, &xa->v4, sizeof(in4->sin_addr)); 83 break; 84 case AF_INET6: 85 if (*len < sizeof(*in6)) 86 return -1; 87 memset(sa, '\0', sizeof(*in6)); 88 *len = sizeof(*in6); 89 #ifdef SOCK_HAS_LEN 90 in6->sin6_len = sizeof(*in6); 91 #endif 92 in6->sin6_family = AF_INET6; 93 in6->sin6_port = htons(port); 94 memcpy(&in6->sin6_addr, &xa->v6, sizeof(in6->sin6_addr)); 95 #ifdef HAVE_STRUCT_SOCKADDR_IN6_SIN6_SCOPE_ID 96 in6->sin6_scope_id = xa->scope_id; 97 #endif 98 break; 99 default: 100 return -1; 101 } 102 return 0; 103 } 104 105 /* 106 * Convert struct sockaddr to struct xaddr 107 * Returns 0 on success, -1 on failure. 108 */ 109 int 110 addr_sa_to_xaddr(struct sockaddr *sa, socklen_t slen, struct xaddr *xa) 111 { 112 struct sockaddr_in *in4 = (struct sockaddr_in *)sa; 113 struct sockaddr_in6 *in6 = (struct sockaddr_in6 *)sa; 114 115 memset(xa, '\0', sizeof(*xa)); 116 117 switch (sa->sa_family) { 118 case AF_INET: 119 if (slen < (socklen_t)sizeof(*in4)) 120 return -1; 121 xa->af = AF_INET; 122 memcpy(&xa->v4, &in4->sin_addr, sizeof(xa->v4)); 123 break; 124 case AF_INET6: 125 if (slen < (socklen_t)sizeof(*in6)) 126 return -1; 127 xa->af = AF_INET6; 128 memcpy(&xa->v6, &in6->sin6_addr, sizeof(xa->v6)); 129 #ifdef HAVE_STRUCT_SOCKADDR_IN6_SIN6_SCOPE_ID 130 xa->scope_id = in6->sin6_scope_id; 131 #endif 132 break; 133 default: 134 return -1; 135 } 136 137 return 0; 138 } 139 140 int 141 addr_invert(struct xaddr *n) 142 { 143 int i; 144 145 if (n == NULL) 146 return -1; 147 148 switch (n->af) { 149 case AF_INET: 150 n->v4.s_addr = ~n->v4.s_addr; 151 return 0; 152 case AF_INET6: 153 for (i = 0; i < 4; i++) 154 n->addr32[i] = ~n->addr32[i]; 155 return 0; 156 default: 157 return -1; 158 } 159 } 160 161 /* 162 * Calculate a netmask of length 'l' for address family 'af' and 163 * store it in 'n'. 164 * Returns 0 on success, -1 on failure. 165 */ 166 int 167 addr_netmask(int af, u_int l, struct xaddr *n) 168 { 169 int i; 170 171 if (masklen_valid(af, l) != 0 || n == NULL) 172 return -1; 173 174 memset(n, '\0', sizeof(*n)); 175 switch (af) { 176 case AF_INET: 177 n->af = AF_INET; 178 if (l == 0) 179 return 0; 180 n->v4.s_addr = htonl((0xffffffff << (32 - l)) & 0xffffffff); 181 return 0; 182 case AF_INET6: 183 n->af = AF_INET6; 184 for (i = 0; i < 4 && l >= 32; i++, l -= 32) 185 n->addr32[i] = 0xffffffffU; 186 if (i < 4 && l != 0) 187 n->addr32[i] = htonl((0xffffffff << (32 - l)) & 188 0xffffffff); 189 return 0; 190 default: 191 return -1; 192 } 193 } 194 195 int 196 addr_hostmask(int af, u_int l, struct xaddr *n) 197 { 198 if (addr_netmask(af, l, n) == -1 || addr_invert(n) == -1) 199 return -1; 200 return 0; 201 } 202 203 /* 204 * Perform logical AND of addresses 'a' and 'b', storing result in 'dst'. 205 * Returns 0 on success, -1 on failure. 206 */ 207 int 208 addr_and(struct xaddr *dst, const struct xaddr *a, const struct xaddr *b) 209 { 210 int i; 211 212 if (dst == NULL || a == NULL || b == NULL || a->af != b->af) 213 return -1; 214 215 memcpy(dst, a, sizeof(*dst)); 216 switch (a->af) { 217 case AF_INET: 218 dst->v4.s_addr &= b->v4.s_addr; 219 return 0; 220 case AF_INET6: 221 dst->scope_id = a->scope_id; 222 for (i = 0; i < 4; i++) 223 dst->addr32[i] &= b->addr32[i]; 224 return 0; 225 default: 226 return -1; 227 } 228 } 229 230 int 231 addr_cmp(const struct xaddr *a, const struct xaddr *b) 232 { 233 int i; 234 235 if (a->af != b->af) 236 return (a->af == AF_INET6 ? 1 : -1); 237 238 switch (a->af) { 239 case AF_INET: 240 /* 241 * Can't just subtract here as 255.255.255.255 - 0.0.0.0 is 242 * too big to fit into a signed int 243 */ 244 if (a->v4.s_addr == b->v4.s_addr) 245 return 0; 246 return (ntohl(a->v4.s_addr) > ntohl(b->v4.s_addr) ? 1 : -1); 247 case AF_INET6: 248 /* 249 * Do this a byte at a time to avoid the above issue and 250 * any endian problems 251 */ 252 for (i = 0; i < 16; i++) 253 if (a->addr8[i] - b->addr8[i] != 0) 254 return (a->addr8[i] - b->addr8[i]); 255 if (a->scope_id == b->scope_id) 256 return (0); 257 return (a->scope_id > b->scope_id ? 1 : -1); 258 default: 259 return (-1); 260 } 261 } 262 263 int 264 addr_is_all0s(const struct xaddr *a) 265 { 266 int i; 267 268 switch (a->af) { 269 case AF_INET: 270 return (a->v4.s_addr == 0 ? 0 : -1); 271 case AF_INET6: 272 for (i = 0; i < 4; i++) 273 if (a->addr32[i] != 0) 274 return -1; 275 return 0; 276 default: 277 return -1; 278 } 279 } 280 281 /* 282 * Test whether host portion of address 'a', as determined by 'masklen' 283 * is all zeros. 284 * Returns 0 if host portion of address is all-zeros, 285 * -1 if not all zeros or on failure. 286 */ 287 int 288 addr_host_is_all0s(const struct xaddr *a, u_int masklen) 289 { 290 struct xaddr tmp_addr, tmp_mask, tmp_result; 291 292 memcpy(&tmp_addr, a, sizeof(tmp_addr)); 293 if (addr_hostmask(a->af, masklen, &tmp_mask) == -1) 294 return -1; 295 if (addr_and(&tmp_result, &tmp_addr, &tmp_mask) == -1) 296 return -1; 297 return addr_is_all0s(&tmp_result); 298 } 299 300 /* 301 * Parse string address 'p' into 'n'. 302 * Returns 0 on success, -1 on failure. 303 */ 304 int 305 addr_pton(const char *p, struct xaddr *n) 306 { 307 struct addrinfo hints, *ai; 308 309 memset(&hints, '\0', sizeof(hints)); 310 hints.ai_flags = AI_NUMERICHOST; 311 312 if (p == NULL || getaddrinfo(p, NULL, &hints, &ai) != 0) 313 return -1; 314 315 if (ai == NULL) 316 return -1; 317 318 if (ai->ai_addr == NULL) { 319 freeaddrinfo(ai); 320 return -1; 321 } 322 323 if (n != NULL && addr_sa_to_xaddr(ai->ai_addr, ai->ai_addrlen, 324 n) == -1) { 325 freeaddrinfo(ai); 326 return -1; 327 } 328 329 freeaddrinfo(ai); 330 return 0; 331 } 332 333 int 334 addr_sa_pton(const char *h, const char *s, struct sockaddr *sa, socklen_t slen) 335 { 336 struct addrinfo hints, *ai; 337 338 memset(&hints, '\0', sizeof(hints)); 339 hints.ai_flags = AI_NUMERICHOST; 340 341 if (h == NULL || getaddrinfo(h, s, &hints, &ai) != 0) 342 return -1; 343 344 if (ai == NULL) 345 return -1; 346 347 if (ai->ai_addr == NULL) { 348 freeaddrinfo(ai); 349 return -1; 350 } 351 352 if (sa != NULL) { 353 if (slen < ai->ai_addrlen) { 354 freeaddrinfo(ai); 355 return -1; 356 } 357 memcpy(sa, &ai->ai_addr, ai->ai_addrlen); 358 } 359 360 freeaddrinfo(ai); 361 return 0; 362 } 363 364 int 365 addr_ntop(const struct xaddr *n, char *p, size_t len) 366 { 367 struct sockaddr_storage ss; 368 socklen_t slen = sizeof(ss); 369 370 if (addr_xaddr_to_sa(n, _SA(&ss), &slen, 0) == -1) 371 return -1; 372 if (p == NULL || len == 0) 373 return -1; 374 if (getnameinfo(_SA(&ss), slen, p, len, NULL, 0, 375 NI_NUMERICHOST) == -1) 376 return -1; 377 378 return 0; 379 } 380 381 /* 382 * Parse a CIDR address (x.x.x.x/y or xxxx:yyyy::/z). 383 * Return -1 on parse error, -2 on inconsistency or 0 on success. 384 */ 385 int 386 addr_pton_cidr(const char *p, struct xaddr *n, u_int *l) 387 { 388 struct xaddr tmp; 389 long unsigned int masklen = 999; 390 char addrbuf[64], *mp, *cp; 391 392 /* Don't modify argument */ 393 if (p == NULL || strlcpy(addrbuf, p, sizeof(addrbuf)) >= sizeof(addrbuf)) 394 return -1; 395 396 if ((mp = strchr(addrbuf, '/')) != NULL) { 397 *mp = '\0'; 398 mp++; 399 masklen = strtoul(mp, &cp, 10); 400 if (*mp == '\0' || *cp != '\0' || masklen > 128) 401 return -1; 402 } 403 404 if (addr_pton(addrbuf, &tmp) == -1) 405 return -1; 406 407 if (mp == NULL) 408 masklen = addr_unicast_masklen(tmp.af); 409 if (masklen_valid(tmp.af, masklen) == -1) 410 return -2; 411 if (addr_host_is_all0s(&tmp, masklen) != 0) 412 return -2; 413 414 if (n != NULL) 415 memcpy(n, &tmp, sizeof(*n)); 416 if (l != NULL) 417 *l = masklen; 418 419 return 0; 420 } 421 422 int 423 addr_netmatch(const struct xaddr *host, const struct xaddr *net, u_int masklen) 424 { 425 struct xaddr tmp_mask, tmp_result; 426 427 if (host->af != net->af) 428 return -1; 429 430 if (addr_netmask(host->af, masklen, &tmp_mask) == -1) 431 return -1; 432 if (addr_and(&tmp_result, host, &tmp_mask) == -1) 433 return -1; 434 return addr_cmp(&tmp_result, net); 435 } 436