1295367Sdes/* $OpenBSD: addrmatch.c,v 1.10 2015/07/08 19:04:21 markus 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: 90262566Sdes if (slen < (socklen_t)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: 96262566Sdes if (slen < (socklen_t)sizeof(*in6)) 97180750Sdes return -1; 98180750Sdes xa->af = AF_INET6; 99180750Sdes memcpy(&xa->v6, &in6->sin6_addr, sizeof(xa->v6)); 100192595Sdes#ifdef HAVE_STRUCT_SOCKADDR_IN6_SIN6_SCOPE_ID 101180750Sdes xa->scope_id = in6->sin6_scope_id; 102192595Sdes#endif 103180750Sdes break; 104180750Sdes default: 105180750Sdes return -1; 106180750Sdes } 107180750Sdes 108180750Sdes return 0; 109180750Sdes} 110180750Sdes 111180750Sdes/* 112180750Sdes * Calculate a netmask of length 'l' for address family 'af' and 113180750Sdes * store it in 'n'. 114180750Sdes * Returns 0 on success, -1 on failure. 115180750Sdes */ 116180750Sdesstatic int 117180750Sdesaddr_netmask(int af, u_int l, struct xaddr *n) 118180750Sdes{ 119180750Sdes int i; 120180750Sdes 121180750Sdes if (masklen_valid(af, l) != 0 || n == NULL) 122180750Sdes return -1; 123180750Sdes 124180750Sdes memset(n, '\0', sizeof(*n)); 125180750Sdes switch (af) { 126180750Sdes case AF_INET: 127180750Sdes n->af = AF_INET; 128204917Sdes if (l == 0) 129204917Sdes return 0; 130180750Sdes n->v4.s_addr = htonl((0xffffffff << (32 - l)) & 0xffffffff); 131180750Sdes return 0; 132180750Sdes case AF_INET6: 133180750Sdes n->af = AF_INET6; 134180750Sdes for (i = 0; i < 4 && l >= 32; i++, l -= 32) 135180750Sdes n->addr32[i] = 0xffffffffU; 136180750Sdes if (i < 4 && l != 0) 137180750Sdes n->addr32[i] = htonl((0xffffffff << (32 - l)) & 138180750Sdes 0xffffffff); 139180750Sdes return 0; 140180750Sdes default: 141180750Sdes return -1; 142180750Sdes } 143180750Sdes} 144180750Sdes 145180750Sdes/* 146180750Sdes * Perform logical AND of addresses 'a' and 'b', storing result in 'dst'. 147180750Sdes * Returns 0 on success, -1 on failure. 148180750Sdes */ 149180750Sdesstatic int 150180750Sdesaddr_and(struct xaddr *dst, const struct xaddr *a, const struct xaddr *b) 151180750Sdes{ 152180750Sdes int i; 153180750Sdes 154180750Sdes if (dst == NULL || a == NULL || b == NULL || a->af != b->af) 155180750Sdes return -1; 156180750Sdes 157180750Sdes memcpy(dst, a, sizeof(*dst)); 158180750Sdes switch (a->af) { 159180750Sdes case AF_INET: 160180750Sdes dst->v4.s_addr &= b->v4.s_addr; 161180750Sdes return 0; 162180750Sdes case AF_INET6: 163180750Sdes dst->scope_id = a->scope_id; 164180750Sdes for (i = 0; i < 4; i++) 165180750Sdes dst->addr32[i] &= b->addr32[i]; 166180750Sdes return 0; 167180750Sdes default: 168180750Sdes return -1; 169180750Sdes } 170180750Sdes} 171180750Sdes 172180750Sdes/* 173180750Sdes * Compare addresses 'a' and 'b' 174180750Sdes * Return 0 if addresses are identical, -1 if (a < b) or 1 if (a > b) 175180750Sdes */ 176180750Sdesstatic int 177180750Sdesaddr_cmp(const struct xaddr *a, const struct xaddr *b) 178180750Sdes{ 179180750Sdes int i; 180180750Sdes 181180750Sdes if (a->af != b->af) 182180750Sdes return a->af == AF_INET6 ? 1 : -1; 183180750Sdes 184180750Sdes switch (a->af) { 185180750Sdes case AF_INET: 186180750Sdes if (a->v4.s_addr == b->v4.s_addr) 187180750Sdes return 0; 188180750Sdes return ntohl(a->v4.s_addr) > ntohl(b->v4.s_addr) ? 1 : -1; 189180750Sdes case AF_INET6: 190180750Sdes for (i = 0; i < 16; i++) 191180750Sdes if (a->addr8[i] - b->addr8[i] != 0) 192180750Sdes return a->addr8[i] > b->addr8[i] ? 1 : -1; 193180750Sdes if (a->scope_id == b->scope_id) 194180750Sdes return 0; 195180750Sdes return a->scope_id > b->scope_id ? 1 : -1; 196180750Sdes default: 197180750Sdes return -1; 198180750Sdes } 199180750Sdes} 200180750Sdes 201180750Sdes/* 202180750Sdes * Parse string address 'p' into 'n' 203180750Sdes * Returns 0 on success, -1 on failure. 204180750Sdes */ 205180750Sdesstatic int 206180750Sdesaddr_pton(const char *p, struct xaddr *n) 207180750Sdes{ 208180750Sdes struct addrinfo hints, *ai; 209180750Sdes 210180750Sdes memset(&hints, '\0', sizeof(hints)); 211180750Sdes hints.ai_flags = AI_NUMERICHOST; 212180750Sdes 213180750Sdes if (p == NULL || getaddrinfo(p, NULL, &hints, &ai) != 0) 214180750Sdes return -1; 215180750Sdes 216180750Sdes if (ai == NULL || ai->ai_addr == NULL) 217180750Sdes return -1; 218180750Sdes 219180750Sdes if (n != NULL && 220180750Sdes addr_sa_to_xaddr(ai->ai_addr, ai->ai_addrlen, n) == -1) { 221180750Sdes freeaddrinfo(ai); 222180750Sdes return -1; 223180750Sdes } 224180750Sdes 225180750Sdes freeaddrinfo(ai); 226180750Sdes return 0; 227180750Sdes} 228180750Sdes 229180750Sdes/* 230180750Sdes * Perform bitwise negation of address 231180750Sdes * Returns 0 on success, -1 on failure. 232180750Sdes */ 233180750Sdesstatic int 234180750Sdesaddr_invert(struct xaddr *n) 235180750Sdes{ 236180750Sdes int i; 237180750Sdes 238180750Sdes if (n == NULL) 239180750Sdes return (-1); 240180750Sdes 241180750Sdes switch (n->af) { 242180750Sdes case AF_INET: 243180750Sdes n->v4.s_addr = ~n->v4.s_addr; 244180750Sdes return (0); 245180750Sdes case AF_INET6: 246180750Sdes for (i = 0; i < 4; i++) 247180750Sdes n->addr32[i] = ~n->addr32[i]; 248180750Sdes return (0); 249180750Sdes default: 250180750Sdes return (-1); 251180750Sdes } 252180750Sdes} 253180750Sdes 254180750Sdes/* 255180750Sdes * Calculate a netmask of length 'l' for address family 'af' and 256180750Sdes * store it in 'n'. 257180750Sdes * Returns 0 on success, -1 on failure. 258180750Sdes */ 259180750Sdesstatic int 260180750Sdesaddr_hostmask(int af, u_int l, struct xaddr *n) 261180750Sdes{ 262180750Sdes if (addr_netmask(af, l, n) == -1 || addr_invert(n) == -1) 263180750Sdes return (-1); 264180750Sdes return (0); 265180750Sdes} 266180750Sdes 267180750Sdes/* 268180750Sdes * Test whether address 'a' is all zeros (i.e. 0.0.0.0 or ::) 269180750Sdes * Returns 0 on if address is all-zeros, -1 if not all zeros or on failure. 270180750Sdes */ 271180750Sdesstatic int 272180750Sdesaddr_is_all0s(const struct xaddr *a) 273180750Sdes{ 274180750Sdes int i; 275180750Sdes 276180750Sdes switch (a->af) { 277180750Sdes case AF_INET: 278180750Sdes return (a->v4.s_addr == 0 ? 0 : -1); 279180750Sdes case AF_INET6:; 280180750Sdes for (i = 0; i < 4; i++) 281180750Sdes if (a->addr32[i] != 0) 282180750Sdes return (-1); 283180750Sdes return (0); 284180750Sdes default: 285180750Sdes return (-1); 286180750Sdes } 287180750Sdes} 288180750Sdes 289180750Sdes/* 290180750Sdes * Test whether host portion of address 'a', as determined by 'masklen' 291180750Sdes * is all zeros. 292180750Sdes * Returns 0 on if host portion of address is all-zeros, 293180750Sdes * -1 if not all zeros or on failure. 294180750Sdes */ 295180750Sdesstatic int 296180750Sdesaddr_host_is_all0s(const struct xaddr *a, u_int masklen) 297180750Sdes{ 298180750Sdes struct xaddr tmp_addr, tmp_mask, tmp_result; 299180750Sdes 300180750Sdes memcpy(&tmp_addr, a, sizeof(tmp_addr)); 301180750Sdes if (addr_hostmask(a->af, masklen, &tmp_mask) == -1) 302180750Sdes return (-1); 303180750Sdes if (addr_and(&tmp_result, &tmp_addr, &tmp_mask) == -1) 304180750Sdes return (-1); 305180750Sdes return (addr_is_all0s(&tmp_result)); 306180750Sdes} 307180750Sdes 308180750Sdes/* 309180750Sdes * Parse a CIDR address (x.x.x.x/y or xxxx:yyyy::/z). 310180750Sdes * Return -1 on parse error, -2 on inconsistency or 0 on success. 311180750Sdes */ 312180750Sdesstatic int 313180750Sdesaddr_pton_cidr(const char *p, struct xaddr *n, u_int *l) 314180750Sdes{ 315180750Sdes struct xaddr tmp; 316180750Sdes long unsigned int masklen = 999; 317180750Sdes char addrbuf[64], *mp, *cp; 318180750Sdes 319180750Sdes /* Don't modify argument */ 320240075Sdes if (p == NULL || strlcpy(addrbuf, p, sizeof(addrbuf)) >= sizeof(addrbuf)) 321180750Sdes return -1; 322180750Sdes 323180750Sdes if ((mp = strchr(addrbuf, '/')) != NULL) { 324180750Sdes *mp = '\0'; 325180750Sdes mp++; 326180750Sdes masklen = strtoul(mp, &cp, 10); 327180750Sdes if (*mp == '\0' || *cp != '\0' || masklen > 128) 328180750Sdes return -1; 329180750Sdes } 330180750Sdes 331180750Sdes if (addr_pton(addrbuf, &tmp) == -1) 332180750Sdes return -1; 333180750Sdes 334180750Sdes if (mp == NULL) 335180750Sdes masklen = addr_unicast_masklen(tmp.af); 336180750Sdes if (masklen_valid(tmp.af, masklen) == -1) 337180750Sdes return -2; 338180750Sdes if (addr_host_is_all0s(&tmp, masklen) != 0) 339180750Sdes return -2; 340180750Sdes 341180750Sdes if (n != NULL) 342180750Sdes memcpy(n, &tmp, sizeof(*n)); 343180750Sdes if (l != NULL) 344180750Sdes *l = masklen; 345180750Sdes 346180750Sdes return 0; 347180750Sdes} 348180750Sdes 349180750Sdesstatic int 350180750Sdesaddr_netmatch(const struct xaddr *host, const struct xaddr *net, u_int masklen) 351180750Sdes{ 352180750Sdes struct xaddr tmp_mask, tmp_result; 353180750Sdes 354180750Sdes if (host->af != net->af) 355180750Sdes return -1; 356180750Sdes 357180750Sdes if (addr_netmask(host->af, masklen, &tmp_mask) == -1) 358180750Sdes return -1; 359180750Sdes if (addr_and(&tmp_result, host, &tmp_mask) == -1) 360180750Sdes return -1; 361180750Sdes return addr_cmp(&tmp_result, net); 362180750Sdes} 363180750Sdes 364180750Sdes/* 365180750Sdes * Match "addr" against list pattern list "_list", which may contain a 366180750Sdes * mix of CIDR addresses and old-school wildcards. 367180750Sdes * 368180750Sdes * If addr is NULL, then no matching is performed, but _list is parsed 369180750Sdes * and checked for well-formedness. 370180750Sdes * 371180750Sdes * Returns 1 on match found (never returned when addr == NULL). 372180750Sdes * Returns 0 on if no match found, or no errors found when addr == NULL. 373180750Sdes * Returns -1 on negated match found (never returned when addr == NULL). 374180750Sdes * Returns -2 on invalid list entry. 375180750Sdes */ 376180750Sdesint 377180750Sdesaddr_match_list(const char *addr, const char *_list) 378180750Sdes{ 379180750Sdes char *list, *cp, *o; 380180750Sdes struct xaddr try_addr, match_addr; 381180750Sdes u_int masklen, neg; 382180750Sdes int ret = 0, r; 383180750Sdes 384180750Sdes if (addr != NULL && addr_pton(addr, &try_addr) != 0) { 385180750Sdes debug2("%s: couldn't parse address %.100s", __func__, addr); 386180750Sdes return 0; 387180750Sdes } 388180750Sdes if ((o = list = strdup(_list)) == NULL) 389180750Sdes return -1; 390180750Sdes while ((cp = strsep(&list, ",")) != NULL) { 391180750Sdes neg = *cp == '!'; 392180750Sdes if (neg) 393180750Sdes cp++; 394180750Sdes if (*cp == '\0') { 395180750Sdes ret = -2; 396180750Sdes break; 397180750Sdes } 398180750Sdes /* Prefer CIDR address matching */ 399180750Sdes r = addr_pton_cidr(cp, &match_addr, &masklen); 400180750Sdes if (r == -2) { 401180750Sdes error("Inconsistent mask length for " 402180750Sdes "network \"%.100s\"", cp); 403180750Sdes ret = -2; 404180750Sdes break; 405180750Sdes } else if (r == 0) { 406180750Sdes if (addr != NULL && addr_netmatch(&try_addr, 407180750Sdes &match_addr, masklen) == 0) { 408180750Sdes foundit: 409180750Sdes if (neg) { 410180750Sdes ret = -1; 411180750Sdes break; 412180750Sdes } 413180750Sdes ret = 1; 414180750Sdes } 415180750Sdes continue; 416180750Sdes } else { 417180750Sdes /* If CIDR parse failed, try wildcard string match */ 418180750Sdes if (addr != NULL && match_pattern(addr, cp) == 1) 419180750Sdes goto foundit; 420180750Sdes } 421180750Sdes } 422255767Sdes free(o); 423180750Sdes 424180750Sdes return ret; 425180750Sdes} 426204917Sdes 427204917Sdes/* 428204917Sdes * Match "addr" against list CIDR list "_list". Lexical wildcards and 429204917Sdes * negation are not supported. If "addr" == NULL, will verify structure 430204917Sdes * of "_list". 431204917Sdes * 432204917Sdes * Returns 1 on match found (never returned when addr == NULL). 433204917Sdes * Returns 0 on if no match found, or no errors found when addr == NULL. 434204917Sdes * Returns -1 on error 435204917Sdes */ 436204917Sdesint 437204917Sdesaddr_match_cidr_list(const char *addr, const char *_list) 438204917Sdes{ 439204917Sdes char *list, *cp, *o; 440204917Sdes struct xaddr try_addr, match_addr; 441204917Sdes u_int masklen; 442204917Sdes int ret = 0, r; 443204917Sdes 444204917Sdes if (addr != NULL && addr_pton(addr, &try_addr) != 0) { 445204917Sdes debug2("%s: couldn't parse address %.100s", __func__, addr); 446204917Sdes return 0; 447204917Sdes } 448204917Sdes if ((o = list = strdup(_list)) == NULL) 449204917Sdes return -1; 450204917Sdes while ((cp = strsep(&list, ",")) != NULL) { 451204917Sdes if (*cp == '\0') { 452204917Sdes error("%s: empty entry in list \"%.100s\"", 453204917Sdes __func__, o); 454204917Sdes ret = -1; 455204917Sdes break; 456204917Sdes } 457204917Sdes 458204917Sdes /* 459204917Sdes * NB. This function is called in pre-auth with untrusted data, 460204917Sdes * so be extra paranoid about junk reaching getaddrino (via 461204917Sdes * addr_pton_cidr). 462204917Sdes */ 463204917Sdes 464204917Sdes /* Stop junk from reaching getaddrinfo. +3 is for masklen */ 465204917Sdes if (strlen(cp) > INET6_ADDRSTRLEN + 3) { 466204917Sdes error("%s: list entry \"%.100s\" too long", 467204917Sdes __func__, cp); 468204917Sdes ret = -1; 469204917Sdes break; 470204917Sdes } 471204917Sdes#define VALID_CIDR_CHARS "0123456789abcdefABCDEF.:/" 472204917Sdes if (strspn(cp, VALID_CIDR_CHARS) != strlen(cp)) { 473204917Sdes error("%s: list entry \"%.100s\" contains invalid " 474204917Sdes "characters", __func__, cp); 475204917Sdes ret = -1; 476204917Sdes } 477204917Sdes 478204917Sdes /* Prefer CIDR address matching */ 479204917Sdes r = addr_pton_cidr(cp, &match_addr, &masklen); 480204917Sdes if (r == -1) { 481204917Sdes error("Invalid network entry \"%.100s\"", cp); 482204917Sdes ret = -1; 483204917Sdes break; 484204917Sdes } else if (r == -2) { 485204917Sdes error("Inconsistent mask length for " 486204917Sdes "network \"%.100s\"", cp); 487204917Sdes ret = -1; 488204917Sdes break; 489204917Sdes } else if (r == 0 && addr != NULL) { 490204917Sdes if (addr_netmatch(&try_addr, &match_addr, 491204917Sdes masklen) == 0) 492204917Sdes ret = 1; 493204917Sdes continue; 494204917Sdes } 495204917Sdes } 496255767Sdes free(o); 497204917Sdes 498204917Sdes return ret; 499204917Sdes} 500