addrmatch.c revision 180750
1180750Sdes/* $OpenBSD: addrmatch.c,v 1.3 2008/06/10 23:06:19 djm Exp $ */ 2180750Sdes 3180750Sdes/* 4180750Sdes * Copyright (c) 2004-2008 Damien Miller <djm@mindrot.org> 5180750Sdes * 6180750Sdes * Permission to use, copy, modify, and distribute this software for any 7180750Sdes * purpose with or without fee is hereby granted, provided that the above 8180750Sdes * copyright notice and this permission notice appear in all copies. 9180750Sdes * 10180750Sdes * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES 11180750Sdes * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF 12180750Sdes * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR 13180750Sdes * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES 14180750Sdes * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN 15180750Sdes * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF 16180750Sdes * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. 17180750Sdes */ 18180750Sdes 19180750Sdes#include "includes.h" 20180750Sdes 21180750Sdes#include <sys/types.h> 22180750Sdes#include <sys/socket.h> 23180750Sdes#include <netinet/in.h> 24180750Sdes#include <arpa/inet.h> 25180750Sdes 26180750Sdes#include <netdb.h> 27180750Sdes#include <string.h> 28180750Sdes#include <stdlib.h> 29180750Sdes#include <stdio.h> 30180750Sdes#include <stdarg.h> 31180750Sdes 32180750Sdes#include "match.h" 33180750Sdes#include "log.h" 34180750Sdes 35180750Sdesstruct xaddr { 36180750Sdes sa_family_t af; 37180750Sdes union { 38180750Sdes struct in_addr v4; 39180750Sdes struct in6_addr v6; 40180750Sdes u_int8_t addr8[16]; 41180750Sdes u_int32_t addr32[4]; 42180750Sdes } xa; /* 128-bit address */ 43180750Sdes u_int32_t scope_id; /* iface scope id for v6 */ 44180750Sdes#define v4 xa.v4 45180750Sdes#define v6 xa.v6 46180750Sdes#define addr8 xa.addr8 47180750Sdes#define addr32 xa.addr32 48180750Sdes}; 49180750Sdes 50180750Sdesstatic int 51180750Sdesaddr_unicast_masklen(int af) 52180750Sdes{ 53180750Sdes switch (af) { 54180750Sdes case AF_INET: 55180750Sdes return 32; 56180750Sdes case AF_INET6: 57180750Sdes return 128; 58180750Sdes default: 59180750Sdes return -1; 60180750Sdes } 61180750Sdes} 62180750Sdes 63180750Sdesstatic inline int 64180750Sdesmasklen_valid(int af, u_int masklen) 65180750Sdes{ 66180750Sdes switch (af) { 67180750Sdes case AF_INET: 68180750Sdes return masklen <= 32 ? 0 : -1; 69180750Sdes case AF_INET6: 70180750Sdes return masklen <= 128 ? 0 : -1; 71180750Sdes default: 72180750Sdes return -1; 73180750Sdes } 74180750Sdes} 75180750Sdes 76180750Sdes/* 77180750Sdes * Convert struct sockaddr to struct xaddr 78180750Sdes * Returns 0 on success, -1 on failure. 79180750Sdes */ 80180750Sdesstatic int 81180750Sdesaddr_sa_to_xaddr(struct sockaddr *sa, socklen_t slen, struct xaddr *xa) 82180750Sdes{ 83180750Sdes struct sockaddr_in *in4 = (struct sockaddr_in *)sa; 84180750Sdes struct sockaddr_in6 *in6 = (struct sockaddr_in6 *)sa; 85180750Sdes 86180750Sdes memset(xa, '\0', sizeof(*xa)); 87180750Sdes 88180750Sdes switch (sa->sa_family) { 89180750Sdes case AF_INET: 90180750Sdes if (slen < sizeof(*in4)) 91180750Sdes return -1; 92180750Sdes xa->af = AF_INET; 93180750Sdes memcpy(&xa->v4, &in4->sin_addr, sizeof(xa->v4)); 94180750Sdes break; 95180750Sdes case AF_INET6: 96180750Sdes if (slen < sizeof(*in6)) 97180750Sdes return -1; 98180750Sdes xa->af = AF_INET6; 99180750Sdes memcpy(&xa->v6, &in6->sin6_addr, sizeof(xa->v6)); 100180750Sdes xa->scope_id = in6->sin6_scope_id; 101180750Sdes break; 102180750Sdes default: 103180750Sdes return -1; 104180750Sdes } 105180750Sdes 106180750Sdes return 0; 107180750Sdes} 108180750Sdes 109180750Sdes/* 110180750Sdes * Calculate a netmask of length 'l' for address family 'af' and 111180750Sdes * store it in 'n'. 112180750Sdes * Returns 0 on success, -1 on failure. 113180750Sdes */ 114180750Sdesstatic int 115180750Sdesaddr_netmask(int af, u_int l, struct xaddr *n) 116180750Sdes{ 117180750Sdes int i; 118180750Sdes 119180750Sdes if (masklen_valid(af, l) != 0 || n == NULL) 120180750Sdes return -1; 121180750Sdes 122180750Sdes memset(n, '\0', sizeof(*n)); 123180750Sdes switch (af) { 124180750Sdes case AF_INET: 125180750Sdes n->af = AF_INET; 126180750Sdes n->v4.s_addr = htonl((0xffffffff << (32 - l)) & 0xffffffff); 127180750Sdes return 0; 128180750Sdes case AF_INET6: 129180750Sdes n->af = AF_INET6; 130180750Sdes for (i = 0; i < 4 && l >= 32; i++, l -= 32) 131180750Sdes n->addr32[i] = 0xffffffffU; 132180750Sdes if (i < 4 && l != 0) 133180750Sdes n->addr32[i] = htonl((0xffffffff << (32 - l)) & 134180750Sdes 0xffffffff); 135180750Sdes return 0; 136180750Sdes default: 137180750Sdes return -1; 138180750Sdes } 139180750Sdes} 140180750Sdes 141180750Sdes/* 142180750Sdes * Perform logical AND of addresses 'a' and 'b', storing result in 'dst'. 143180750Sdes * Returns 0 on success, -1 on failure. 144180750Sdes */ 145180750Sdesstatic int 146180750Sdesaddr_and(struct xaddr *dst, const struct xaddr *a, const struct xaddr *b) 147180750Sdes{ 148180750Sdes int i; 149180750Sdes 150180750Sdes if (dst == NULL || a == NULL || b == NULL || a->af != b->af) 151180750Sdes return -1; 152180750Sdes 153180750Sdes memcpy(dst, a, sizeof(*dst)); 154180750Sdes switch (a->af) { 155180750Sdes case AF_INET: 156180750Sdes dst->v4.s_addr &= b->v4.s_addr; 157180750Sdes return 0; 158180750Sdes case AF_INET6: 159180750Sdes dst->scope_id = a->scope_id; 160180750Sdes for (i = 0; i < 4; i++) 161180750Sdes dst->addr32[i] &= b->addr32[i]; 162180750Sdes return 0; 163180750Sdes default: 164180750Sdes return -1; 165180750Sdes } 166180750Sdes} 167180750Sdes 168180750Sdes/* 169180750Sdes * Compare addresses 'a' and 'b' 170180750Sdes * Return 0 if addresses are identical, -1 if (a < b) or 1 if (a > b) 171180750Sdes */ 172180750Sdesstatic int 173180750Sdesaddr_cmp(const struct xaddr *a, const struct xaddr *b) 174180750Sdes{ 175180750Sdes int i; 176180750Sdes 177180750Sdes if (a->af != b->af) 178180750Sdes return a->af == AF_INET6 ? 1 : -1; 179180750Sdes 180180750Sdes switch (a->af) { 181180750Sdes case AF_INET: 182180750Sdes if (a->v4.s_addr == b->v4.s_addr) 183180750Sdes return 0; 184180750Sdes return ntohl(a->v4.s_addr) > ntohl(b->v4.s_addr) ? 1 : -1; 185180750Sdes case AF_INET6: 186180750Sdes for (i = 0; i < 16; i++) 187180750Sdes if (a->addr8[i] - b->addr8[i] != 0) 188180750Sdes return a->addr8[i] > b->addr8[i] ? 1 : -1; 189180750Sdes if (a->scope_id == b->scope_id) 190180750Sdes return 0; 191180750Sdes return a->scope_id > b->scope_id ? 1 : -1; 192180750Sdes default: 193180750Sdes return -1; 194180750Sdes } 195180750Sdes} 196180750Sdes 197180750Sdes/* 198180750Sdes * Parse string address 'p' into 'n' 199180750Sdes * Returns 0 on success, -1 on failure. 200180750Sdes */ 201180750Sdesstatic int 202180750Sdesaddr_pton(const char *p, struct xaddr *n) 203180750Sdes{ 204180750Sdes struct addrinfo hints, *ai; 205180750Sdes 206180750Sdes memset(&hints, '\0', sizeof(hints)); 207180750Sdes hints.ai_flags = AI_NUMERICHOST; 208180750Sdes 209180750Sdes if (p == NULL || getaddrinfo(p, NULL, &hints, &ai) != 0) 210180750Sdes return -1; 211180750Sdes 212180750Sdes if (ai == NULL || ai->ai_addr == NULL) 213180750Sdes return -1; 214180750Sdes 215180750Sdes if (n != NULL && 216180750Sdes addr_sa_to_xaddr(ai->ai_addr, ai->ai_addrlen, n) == -1) { 217180750Sdes freeaddrinfo(ai); 218180750Sdes return -1; 219180750Sdes } 220180750Sdes 221180750Sdes freeaddrinfo(ai); 222180750Sdes return 0; 223180750Sdes} 224180750Sdes 225180750Sdes/* 226180750Sdes * Perform bitwise negation of address 227180750Sdes * Returns 0 on success, -1 on failure. 228180750Sdes */ 229180750Sdesstatic int 230180750Sdesaddr_invert(struct xaddr *n) 231180750Sdes{ 232180750Sdes int i; 233180750Sdes 234180750Sdes if (n == NULL) 235180750Sdes return (-1); 236180750Sdes 237180750Sdes switch (n->af) { 238180750Sdes case AF_INET: 239180750Sdes n->v4.s_addr = ~n->v4.s_addr; 240180750Sdes return (0); 241180750Sdes case AF_INET6: 242180750Sdes for (i = 0; i < 4; i++) 243180750Sdes n->addr32[i] = ~n->addr32[i]; 244180750Sdes return (0); 245180750Sdes default: 246180750Sdes return (-1); 247180750Sdes } 248180750Sdes} 249180750Sdes 250180750Sdes/* 251180750Sdes * Calculate a netmask of length 'l' for address family 'af' and 252180750Sdes * store it in 'n'. 253180750Sdes * Returns 0 on success, -1 on failure. 254180750Sdes */ 255180750Sdesstatic int 256180750Sdesaddr_hostmask(int af, u_int l, struct xaddr *n) 257180750Sdes{ 258180750Sdes if (addr_netmask(af, l, n) == -1 || addr_invert(n) == -1) 259180750Sdes return (-1); 260180750Sdes return (0); 261180750Sdes} 262180750Sdes 263180750Sdes/* 264180750Sdes * Test whether address 'a' is all zeros (i.e. 0.0.0.0 or ::) 265180750Sdes * Returns 0 on if address is all-zeros, -1 if not all zeros or on failure. 266180750Sdes */ 267180750Sdesstatic int 268180750Sdesaddr_is_all0s(const struct xaddr *a) 269180750Sdes{ 270180750Sdes int i; 271180750Sdes 272180750Sdes switch (a->af) { 273180750Sdes case AF_INET: 274180750Sdes return (a->v4.s_addr == 0 ? 0 : -1); 275180750Sdes case AF_INET6:; 276180750Sdes for (i = 0; i < 4; i++) 277180750Sdes if (a->addr32[i] != 0) 278180750Sdes return (-1); 279180750Sdes return (0); 280180750Sdes default: 281180750Sdes return (-1); 282180750Sdes } 283180750Sdes} 284180750Sdes 285180750Sdes/* 286180750Sdes * Test whether host portion of address 'a', as determined by 'masklen' 287180750Sdes * is all zeros. 288180750Sdes * Returns 0 on if host portion of address is all-zeros, 289180750Sdes * -1 if not all zeros or on failure. 290180750Sdes */ 291180750Sdesstatic int 292180750Sdesaddr_host_is_all0s(const struct xaddr *a, u_int masklen) 293180750Sdes{ 294180750Sdes struct xaddr tmp_addr, tmp_mask, tmp_result; 295180750Sdes 296180750Sdes memcpy(&tmp_addr, a, sizeof(tmp_addr)); 297180750Sdes if (addr_hostmask(a->af, masklen, &tmp_mask) == -1) 298180750Sdes return (-1); 299180750Sdes if (addr_and(&tmp_result, &tmp_addr, &tmp_mask) == -1) 300180750Sdes return (-1); 301180750Sdes return (addr_is_all0s(&tmp_result)); 302180750Sdes} 303180750Sdes 304180750Sdes/* 305180750Sdes * Parse a CIDR address (x.x.x.x/y or xxxx:yyyy::/z). 306180750Sdes * Return -1 on parse error, -2 on inconsistency or 0 on success. 307180750Sdes */ 308180750Sdesstatic int 309180750Sdesaddr_pton_cidr(const char *p, struct xaddr *n, u_int *l) 310180750Sdes{ 311180750Sdes struct xaddr tmp; 312180750Sdes long unsigned int masklen = 999; 313180750Sdes char addrbuf[64], *mp, *cp; 314180750Sdes 315180750Sdes /* Don't modify argument */ 316180750Sdes if (p == NULL || strlcpy(addrbuf, p, sizeof(addrbuf)) > sizeof(addrbuf)) 317180750Sdes return -1; 318180750Sdes 319180750Sdes if ((mp = strchr(addrbuf, '/')) != NULL) { 320180750Sdes *mp = '\0'; 321180750Sdes mp++; 322180750Sdes masklen = strtoul(mp, &cp, 10); 323180750Sdes if (*mp == '\0' || *cp != '\0' || masklen > 128) 324180750Sdes return -1; 325180750Sdes } 326180750Sdes 327180750Sdes if (addr_pton(addrbuf, &tmp) == -1) 328180750Sdes return -1; 329180750Sdes 330180750Sdes if (mp == NULL) 331180750Sdes masklen = addr_unicast_masklen(tmp.af); 332180750Sdes if (masklen_valid(tmp.af, masklen) == -1) 333180750Sdes return -2; 334180750Sdes if (addr_host_is_all0s(&tmp, masklen) != 0) 335180750Sdes return -2; 336180750Sdes 337180750Sdes if (n != NULL) 338180750Sdes memcpy(n, &tmp, sizeof(*n)); 339180750Sdes if (l != NULL) 340180750Sdes *l = masklen; 341180750Sdes 342180750Sdes return 0; 343180750Sdes} 344180750Sdes 345180750Sdesstatic int 346180750Sdesaddr_netmatch(const struct xaddr *host, const struct xaddr *net, u_int masklen) 347180750Sdes{ 348180750Sdes struct xaddr tmp_mask, tmp_result; 349180750Sdes 350180750Sdes if (host->af != net->af) 351180750Sdes return -1; 352180750Sdes 353180750Sdes if (addr_netmask(host->af, masklen, &tmp_mask) == -1) 354180750Sdes return -1; 355180750Sdes if (addr_and(&tmp_result, host, &tmp_mask) == -1) 356180750Sdes return -1; 357180750Sdes return addr_cmp(&tmp_result, net); 358180750Sdes} 359180750Sdes 360180750Sdes/* 361180750Sdes * Match "addr" against list pattern list "_list", which may contain a 362180750Sdes * mix of CIDR addresses and old-school wildcards. 363180750Sdes * 364180750Sdes * If addr is NULL, then no matching is performed, but _list is parsed 365180750Sdes * and checked for well-formedness. 366180750Sdes * 367180750Sdes * Returns 1 on match found (never returned when addr == NULL). 368180750Sdes * Returns 0 on if no match found, or no errors found when addr == NULL. 369180750Sdes * Returns -1 on negated match found (never returned when addr == NULL). 370180750Sdes * Returns -2 on invalid list entry. 371180750Sdes */ 372180750Sdesint 373180750Sdesaddr_match_list(const char *addr, const char *_list) 374180750Sdes{ 375180750Sdes char *list, *cp, *o; 376180750Sdes struct xaddr try_addr, match_addr; 377180750Sdes u_int masklen, neg; 378180750Sdes int ret = 0, r; 379180750Sdes 380180750Sdes if (addr != NULL && addr_pton(addr, &try_addr) != 0) { 381180750Sdes debug2("%s: couldn't parse address %.100s", __func__, addr); 382180750Sdes return 0; 383180750Sdes } 384180750Sdes if ((o = list = strdup(_list)) == NULL) 385180750Sdes return -1; 386180750Sdes while ((cp = strsep(&list, ",")) != NULL) { 387180750Sdes neg = *cp == '!'; 388180750Sdes if (neg) 389180750Sdes cp++; 390180750Sdes if (*cp == '\0') { 391180750Sdes ret = -2; 392180750Sdes break; 393180750Sdes } 394180750Sdes /* Prefer CIDR address matching */ 395180750Sdes r = addr_pton_cidr(cp, &match_addr, &masklen); 396180750Sdes if (r == -2) { 397180750Sdes error("Inconsistent mask length for " 398180750Sdes "network \"%.100s\"", cp); 399180750Sdes ret = -2; 400180750Sdes break; 401180750Sdes } else if (r == 0) { 402180750Sdes if (addr != NULL && addr_netmatch(&try_addr, 403180750Sdes &match_addr, masklen) == 0) { 404180750Sdes foundit: 405180750Sdes if (neg) { 406180750Sdes ret = -1; 407180750Sdes break; 408180750Sdes } 409180750Sdes ret = 1; 410180750Sdes } 411180750Sdes continue; 412180750Sdes } else { 413180750Sdes /* If CIDR parse failed, try wildcard string match */ 414180750Sdes if (addr != NULL && match_pattern(addr, cp) == 1) 415180750Sdes goto foundit; 416180750Sdes } 417180750Sdes } 418180750Sdes free(o); 419180750Sdes 420180750Sdes return ret; 421180750Sdes} 422