1255767Sdes/* $OpenBSD: addrmatch.c,v 1.7 2013/05/17 00:13:13 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" 34192595Sdes#include "xmalloc.h" 35180750Sdes 36180750Sdesstruct xaddr { 37180750Sdes sa_family_t af; 38180750Sdes union { 39180750Sdes struct in_addr v4; 40180750Sdes struct in6_addr v6; 41180750Sdes u_int8_t addr8[16]; 42180750Sdes u_int32_t addr32[4]; 43180750Sdes } xa; /* 128-bit address */ 44180750Sdes u_int32_t scope_id; /* iface scope id for v6 */ 45180750Sdes#define v4 xa.v4 46180750Sdes#define v6 xa.v6 47180750Sdes#define addr8 xa.addr8 48180750Sdes#define addr32 xa.addr32 49180750Sdes}; 50180750Sdes 51180750Sdesstatic int 52180750Sdesaddr_unicast_masklen(int af) 53180750Sdes{ 54180750Sdes switch (af) { 55180750Sdes case AF_INET: 56180750Sdes return 32; 57180750Sdes case AF_INET6: 58180750Sdes return 128; 59180750Sdes default: 60180750Sdes return -1; 61180750Sdes } 62180750Sdes} 63180750Sdes 64180750Sdesstatic inline int 65180750Sdesmasklen_valid(int af, u_int masklen) 66180750Sdes{ 67180750Sdes switch (af) { 68180750Sdes case AF_INET: 69180750Sdes return masklen <= 32 ? 0 : -1; 70180750Sdes case AF_INET6: 71180750Sdes return masklen <= 128 ? 0 : -1; 72180750Sdes default: 73180750Sdes return -1; 74180750Sdes } 75180750Sdes} 76180750Sdes 77180750Sdes/* 78180750Sdes * Convert struct sockaddr to struct xaddr 79180750Sdes * Returns 0 on success, -1 on failure. 80180750Sdes */ 81180750Sdesstatic int 82180750Sdesaddr_sa_to_xaddr(struct sockaddr *sa, socklen_t slen, struct xaddr *xa) 83180750Sdes{ 84180750Sdes struct sockaddr_in *in4 = (struct sockaddr_in *)sa; 85180750Sdes struct sockaddr_in6 *in6 = (struct sockaddr_in6 *)sa; 86180750Sdes 87180750Sdes memset(xa, '\0', sizeof(*xa)); 88180750Sdes 89180750Sdes switch (sa->sa_family) { 90180750Sdes case AF_INET: 91180750Sdes if (slen < sizeof(*in4)) 92180750Sdes return -1; 93180750Sdes xa->af = AF_INET; 94180750Sdes memcpy(&xa->v4, &in4->sin_addr, sizeof(xa->v4)); 95180750Sdes break; 96180750Sdes case AF_INET6: 97180750Sdes if (slen < sizeof(*in6)) 98180750Sdes return -1; 99180750Sdes xa->af = AF_INET6; 100180750Sdes memcpy(&xa->v6, &in6->sin6_addr, sizeof(xa->v6)); 101192595Sdes#ifdef HAVE_STRUCT_SOCKADDR_IN6_SIN6_SCOPE_ID 102180750Sdes xa->scope_id = in6->sin6_scope_id; 103192595Sdes#endif 104180750Sdes break; 105180750Sdes default: 106180750Sdes return -1; 107180750Sdes } 108180750Sdes 109180750Sdes return 0; 110180750Sdes} 111180750Sdes 112180750Sdes/* 113180750Sdes * Calculate a netmask of length 'l' for address family 'af' and 114180750Sdes * store it in 'n'. 115180750Sdes * Returns 0 on success, -1 on failure. 116180750Sdes */ 117180750Sdesstatic int 118180750Sdesaddr_netmask(int af, u_int l, struct xaddr *n) 119180750Sdes{ 120180750Sdes int i; 121180750Sdes 122180750Sdes if (masklen_valid(af, l) != 0 || n == NULL) 123180750Sdes return -1; 124180750Sdes 125180750Sdes memset(n, '\0', sizeof(*n)); 126180750Sdes switch (af) { 127180750Sdes case AF_INET: 128180750Sdes n->af = AF_INET; 129204917Sdes if (l == 0) 130204917Sdes return 0; 131180750Sdes n->v4.s_addr = htonl((0xffffffff << (32 - l)) & 0xffffffff); 132180750Sdes return 0; 133180750Sdes case AF_INET6: 134180750Sdes n->af = AF_INET6; 135180750Sdes for (i = 0; i < 4 && l >= 32; i++, l -= 32) 136180750Sdes n->addr32[i] = 0xffffffffU; 137180750Sdes if (i < 4 && l != 0) 138180750Sdes n->addr32[i] = htonl((0xffffffff << (32 - l)) & 139180750Sdes 0xffffffff); 140180750Sdes return 0; 141180750Sdes default: 142180750Sdes return -1; 143180750Sdes } 144180750Sdes} 145180750Sdes 146180750Sdes/* 147180750Sdes * Perform logical AND of addresses 'a' and 'b', storing result in 'dst'. 148180750Sdes * Returns 0 on success, -1 on failure. 149180750Sdes */ 150180750Sdesstatic int 151180750Sdesaddr_and(struct xaddr *dst, const struct xaddr *a, const struct xaddr *b) 152180750Sdes{ 153180750Sdes int i; 154180750Sdes 155180750Sdes if (dst == NULL || a == NULL || b == NULL || a->af != b->af) 156180750Sdes return -1; 157180750Sdes 158180750Sdes memcpy(dst, a, sizeof(*dst)); 159180750Sdes switch (a->af) { 160180750Sdes case AF_INET: 161180750Sdes dst->v4.s_addr &= b->v4.s_addr; 162180750Sdes return 0; 163180750Sdes case AF_INET6: 164180750Sdes dst->scope_id = a->scope_id; 165180750Sdes for (i = 0; i < 4; i++) 166180750Sdes dst->addr32[i] &= b->addr32[i]; 167180750Sdes return 0; 168180750Sdes default: 169180750Sdes return -1; 170180750Sdes } 171180750Sdes} 172180750Sdes 173180750Sdes/* 174180750Sdes * Compare addresses 'a' and 'b' 175180750Sdes * Return 0 if addresses are identical, -1 if (a < b) or 1 if (a > b) 176180750Sdes */ 177180750Sdesstatic int 178180750Sdesaddr_cmp(const struct xaddr *a, const struct xaddr *b) 179180750Sdes{ 180180750Sdes int i; 181180750Sdes 182180750Sdes if (a->af != b->af) 183180750Sdes return a->af == AF_INET6 ? 1 : -1; 184180750Sdes 185180750Sdes switch (a->af) { 186180750Sdes case AF_INET: 187180750Sdes if (a->v4.s_addr == b->v4.s_addr) 188180750Sdes return 0; 189180750Sdes return ntohl(a->v4.s_addr) > ntohl(b->v4.s_addr) ? 1 : -1; 190180750Sdes case AF_INET6: 191180750Sdes for (i = 0; i < 16; i++) 192180750Sdes if (a->addr8[i] - b->addr8[i] != 0) 193180750Sdes return a->addr8[i] > b->addr8[i] ? 1 : -1; 194180750Sdes if (a->scope_id == b->scope_id) 195180750Sdes return 0; 196180750Sdes return a->scope_id > b->scope_id ? 1 : -1; 197180750Sdes default: 198180750Sdes return -1; 199180750Sdes } 200180750Sdes} 201180750Sdes 202180750Sdes/* 203180750Sdes * Parse string address 'p' into 'n' 204180750Sdes * Returns 0 on success, -1 on failure. 205180750Sdes */ 206180750Sdesstatic int 207180750Sdesaddr_pton(const char *p, struct xaddr *n) 208180750Sdes{ 209180750Sdes struct addrinfo hints, *ai; 210180750Sdes 211180750Sdes memset(&hints, '\0', sizeof(hints)); 212180750Sdes hints.ai_flags = AI_NUMERICHOST; 213180750Sdes 214180750Sdes if (p == NULL || getaddrinfo(p, NULL, &hints, &ai) != 0) 215180750Sdes return -1; 216180750Sdes 217180750Sdes if (ai == NULL || ai->ai_addr == NULL) 218180750Sdes return -1; 219180750Sdes 220180750Sdes if (n != NULL && 221180750Sdes addr_sa_to_xaddr(ai->ai_addr, ai->ai_addrlen, n) == -1) { 222180750Sdes freeaddrinfo(ai); 223180750Sdes return -1; 224180750Sdes } 225180750Sdes 226180750Sdes freeaddrinfo(ai); 227180750Sdes return 0; 228180750Sdes} 229180750Sdes 230180750Sdes/* 231180750Sdes * Perform bitwise negation of address 232180750Sdes * Returns 0 on success, -1 on failure. 233180750Sdes */ 234180750Sdesstatic int 235180750Sdesaddr_invert(struct xaddr *n) 236180750Sdes{ 237180750Sdes int i; 238180750Sdes 239180750Sdes if (n == NULL) 240180750Sdes return (-1); 241180750Sdes 242180750Sdes switch (n->af) { 243180750Sdes case AF_INET: 244180750Sdes n->v4.s_addr = ~n->v4.s_addr; 245180750Sdes return (0); 246180750Sdes case AF_INET6: 247180750Sdes for (i = 0; i < 4; i++) 248180750Sdes n->addr32[i] = ~n->addr32[i]; 249180750Sdes return (0); 250180750Sdes default: 251180750Sdes return (-1); 252180750Sdes } 253180750Sdes} 254180750Sdes 255180750Sdes/* 256180750Sdes * Calculate a netmask of length 'l' for address family 'af' and 257180750Sdes * store it in 'n'. 258180750Sdes * Returns 0 on success, -1 on failure. 259180750Sdes */ 260180750Sdesstatic int 261180750Sdesaddr_hostmask(int af, u_int l, struct xaddr *n) 262180750Sdes{ 263180750Sdes if (addr_netmask(af, l, n) == -1 || addr_invert(n) == -1) 264180750Sdes return (-1); 265180750Sdes return (0); 266180750Sdes} 267180750Sdes 268180750Sdes/* 269180750Sdes * Test whether address 'a' is all zeros (i.e. 0.0.0.0 or ::) 270180750Sdes * Returns 0 on if address is all-zeros, -1 if not all zeros or on failure. 271180750Sdes */ 272180750Sdesstatic int 273180750Sdesaddr_is_all0s(const struct xaddr *a) 274180750Sdes{ 275180750Sdes int i; 276180750Sdes 277180750Sdes switch (a->af) { 278180750Sdes case AF_INET: 279180750Sdes return (a->v4.s_addr == 0 ? 0 : -1); 280180750Sdes case AF_INET6:; 281180750Sdes for (i = 0; i < 4; i++) 282180750Sdes if (a->addr32[i] != 0) 283180750Sdes return (-1); 284180750Sdes return (0); 285180750Sdes default: 286180750Sdes return (-1); 287180750Sdes } 288180750Sdes} 289180750Sdes 290180750Sdes/* 291180750Sdes * Test whether host portion of address 'a', as determined by 'masklen' 292180750Sdes * is all zeros. 293180750Sdes * Returns 0 on if host portion of address is all-zeros, 294180750Sdes * -1 if not all zeros or on failure. 295180750Sdes */ 296180750Sdesstatic int 297180750Sdesaddr_host_is_all0s(const struct xaddr *a, u_int masklen) 298180750Sdes{ 299180750Sdes struct xaddr tmp_addr, tmp_mask, tmp_result; 300180750Sdes 301180750Sdes memcpy(&tmp_addr, a, sizeof(tmp_addr)); 302180750Sdes if (addr_hostmask(a->af, masklen, &tmp_mask) == -1) 303180750Sdes return (-1); 304180750Sdes if (addr_and(&tmp_result, &tmp_addr, &tmp_mask) == -1) 305180750Sdes return (-1); 306180750Sdes return (addr_is_all0s(&tmp_result)); 307180750Sdes} 308180750Sdes 309180750Sdes/* 310180750Sdes * Parse a CIDR address (x.x.x.x/y or xxxx:yyyy::/z). 311180750Sdes * Return -1 on parse error, -2 on inconsistency or 0 on success. 312180750Sdes */ 313180750Sdesstatic int 314180750Sdesaddr_pton_cidr(const char *p, struct xaddr *n, u_int *l) 315180750Sdes{ 316180750Sdes struct xaddr tmp; 317180750Sdes long unsigned int masklen = 999; 318180750Sdes char addrbuf[64], *mp, *cp; 319180750Sdes 320180750Sdes /* Don't modify argument */ 321240075Sdes if (p == NULL || strlcpy(addrbuf, p, sizeof(addrbuf)) >= sizeof(addrbuf)) 322180750Sdes return -1; 323180750Sdes 324180750Sdes if ((mp = strchr(addrbuf, '/')) != NULL) { 325180750Sdes *mp = '\0'; 326180750Sdes mp++; 327180750Sdes masklen = strtoul(mp, &cp, 10); 328180750Sdes if (*mp == '\0' || *cp != '\0' || masklen > 128) 329180750Sdes return -1; 330180750Sdes } 331180750Sdes 332180750Sdes if (addr_pton(addrbuf, &tmp) == -1) 333180750Sdes return -1; 334180750Sdes 335180750Sdes if (mp == NULL) 336180750Sdes masklen = addr_unicast_masklen(tmp.af); 337180750Sdes if (masklen_valid(tmp.af, masklen) == -1) 338180750Sdes return -2; 339180750Sdes if (addr_host_is_all0s(&tmp, masklen) != 0) 340180750Sdes return -2; 341180750Sdes 342180750Sdes if (n != NULL) 343180750Sdes memcpy(n, &tmp, sizeof(*n)); 344180750Sdes if (l != NULL) 345180750Sdes *l = masklen; 346180750Sdes 347180750Sdes return 0; 348180750Sdes} 349180750Sdes 350180750Sdesstatic int 351180750Sdesaddr_netmatch(const struct xaddr *host, const struct xaddr *net, u_int masklen) 352180750Sdes{ 353180750Sdes struct xaddr tmp_mask, tmp_result; 354180750Sdes 355180750Sdes if (host->af != net->af) 356180750Sdes return -1; 357180750Sdes 358180750Sdes if (addr_netmask(host->af, masklen, &tmp_mask) == -1) 359180750Sdes return -1; 360180750Sdes if (addr_and(&tmp_result, host, &tmp_mask) == -1) 361180750Sdes return -1; 362180750Sdes return addr_cmp(&tmp_result, net); 363180750Sdes} 364180750Sdes 365180750Sdes/* 366180750Sdes * Match "addr" against list pattern list "_list", which may contain a 367180750Sdes * mix of CIDR addresses and old-school wildcards. 368180750Sdes * 369180750Sdes * If addr is NULL, then no matching is performed, but _list is parsed 370180750Sdes * and checked for well-formedness. 371180750Sdes * 372180750Sdes * Returns 1 on match found (never returned when addr == NULL). 373180750Sdes * Returns 0 on if no match found, or no errors found when addr == NULL. 374180750Sdes * Returns -1 on negated match found (never returned when addr == NULL). 375180750Sdes * Returns -2 on invalid list entry. 376180750Sdes */ 377180750Sdesint 378180750Sdesaddr_match_list(const char *addr, const char *_list) 379180750Sdes{ 380180750Sdes char *list, *cp, *o; 381180750Sdes struct xaddr try_addr, match_addr; 382180750Sdes u_int masklen, neg; 383180750Sdes int ret = 0, r; 384180750Sdes 385180750Sdes if (addr != NULL && addr_pton(addr, &try_addr) != 0) { 386180750Sdes debug2("%s: couldn't parse address %.100s", __func__, addr); 387180750Sdes return 0; 388180750Sdes } 389180750Sdes if ((o = list = strdup(_list)) == NULL) 390180750Sdes return -1; 391180750Sdes while ((cp = strsep(&list, ",")) != NULL) { 392180750Sdes neg = *cp == '!'; 393180750Sdes if (neg) 394180750Sdes cp++; 395180750Sdes if (*cp == '\0') { 396180750Sdes ret = -2; 397180750Sdes break; 398180750Sdes } 399180750Sdes /* Prefer CIDR address matching */ 400180750Sdes r = addr_pton_cidr(cp, &match_addr, &masklen); 401180750Sdes if (r == -2) { 402180750Sdes error("Inconsistent mask length for " 403180750Sdes "network \"%.100s\"", cp); 404180750Sdes ret = -2; 405180750Sdes break; 406180750Sdes } else if (r == 0) { 407180750Sdes if (addr != NULL && addr_netmatch(&try_addr, 408180750Sdes &match_addr, masklen) == 0) { 409180750Sdes foundit: 410180750Sdes if (neg) { 411180750Sdes ret = -1; 412180750Sdes break; 413180750Sdes } 414180750Sdes ret = 1; 415180750Sdes } 416180750Sdes continue; 417180750Sdes } else { 418180750Sdes /* If CIDR parse failed, try wildcard string match */ 419180750Sdes if (addr != NULL && match_pattern(addr, cp) == 1) 420180750Sdes goto foundit; 421180750Sdes } 422180750Sdes } 423255767Sdes free(o); 424180750Sdes 425180750Sdes return ret; 426180750Sdes} 427204917Sdes 428204917Sdes/* 429204917Sdes * Match "addr" against list CIDR list "_list". Lexical wildcards and 430204917Sdes * negation are not supported. If "addr" == NULL, will verify structure 431204917Sdes * of "_list". 432204917Sdes * 433204917Sdes * Returns 1 on match found (never returned when addr == NULL). 434204917Sdes * Returns 0 on if no match found, or no errors found when addr == NULL. 435204917Sdes * Returns -1 on error 436204917Sdes */ 437204917Sdesint 438204917Sdesaddr_match_cidr_list(const char *addr, const char *_list) 439204917Sdes{ 440204917Sdes char *list, *cp, *o; 441204917Sdes struct xaddr try_addr, match_addr; 442204917Sdes u_int masklen; 443204917Sdes int ret = 0, r; 444204917Sdes 445204917Sdes if (addr != NULL && addr_pton(addr, &try_addr) != 0) { 446204917Sdes debug2("%s: couldn't parse address %.100s", __func__, addr); 447204917Sdes return 0; 448204917Sdes } 449204917Sdes if ((o = list = strdup(_list)) == NULL) 450204917Sdes return -1; 451204917Sdes while ((cp = strsep(&list, ",")) != NULL) { 452204917Sdes if (*cp == '\0') { 453204917Sdes error("%s: empty entry in list \"%.100s\"", 454204917Sdes __func__, o); 455204917Sdes ret = -1; 456204917Sdes break; 457204917Sdes } 458204917Sdes 459204917Sdes /* 460204917Sdes * NB. This function is called in pre-auth with untrusted data, 461204917Sdes * so be extra paranoid about junk reaching getaddrino (via 462204917Sdes * addr_pton_cidr). 463204917Sdes */ 464204917Sdes 465204917Sdes /* Stop junk from reaching getaddrinfo. +3 is for masklen */ 466204917Sdes if (strlen(cp) > INET6_ADDRSTRLEN + 3) { 467204917Sdes error("%s: list entry \"%.100s\" too long", 468204917Sdes __func__, cp); 469204917Sdes ret = -1; 470204917Sdes break; 471204917Sdes } 472204917Sdes#define VALID_CIDR_CHARS "0123456789abcdefABCDEF.:/" 473204917Sdes if (strspn(cp, VALID_CIDR_CHARS) != strlen(cp)) { 474204917Sdes error("%s: list entry \"%.100s\" contains invalid " 475204917Sdes "characters", __func__, cp); 476204917Sdes ret = -1; 477204917Sdes } 478204917Sdes 479204917Sdes /* Prefer CIDR address matching */ 480204917Sdes r = addr_pton_cidr(cp, &match_addr, &masklen); 481204917Sdes if (r == -1) { 482204917Sdes error("Invalid network entry \"%.100s\"", cp); 483204917Sdes ret = -1; 484204917Sdes break; 485204917Sdes } else if (r == -2) { 486204917Sdes error("Inconsistent mask length for " 487204917Sdes "network \"%.100s\"", cp); 488204917Sdes ret = -1; 489204917Sdes break; 490204917Sdes } else if (r == 0 && addr != NULL) { 491204917Sdes if (addr_netmatch(&try_addr, &match_addr, 492204917Sdes masklen) == 0) 493204917Sdes ret = 1; 494204917Sdes continue; 495204917Sdes } 496204917Sdes } 497255767Sdes free(o); 498204917Sdes 499204917Sdes return ret; 500204917Sdes} 501