| /* $OpenBSD: addrmatch.c,v 1.14 2018/07/31 03:07:24 djm Exp $ */ |
| |
| /* |
| * Copyright (c) 2004-2008 Damien Miller <djm@mindrot.org> |
| * |
| * Permission to use, copy, modify, and distribute this software for any |
| * purpose with or without fee is hereby granted, provided that the above |
| * copyright notice and this permission notice appear in all copies. |
| * |
| * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES |
| * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF |
| * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR |
| * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES |
| * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN |
| * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF |
| * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. |
| */ |
| |
| #include "includes.h" |
| |
| #include <sys/types.h> |
| #include <sys/socket.h> |
| #include <netinet/in.h> |
| #include <arpa/inet.h> |
| |
| #include <netdb.h> |
| #include <string.h> |
| #include <stdlib.h> |
| #include <stdio.h> |
| #include <stdarg.h> |
| |
| #include "match.h" |
| #include "log.h" |
| |
| struct xaddr { |
| sa_family_t af; |
| union { |
| struct in_addr v4; |
| struct in6_addr v6; |
| u_int8_t addr8[16]; |
| u_int32_t addr32[4]; |
| } xa; /* 128-bit address */ |
| u_int32_t scope_id; /* iface scope id for v6 */ |
| #define v4 xa.v4 |
| #define v6 xa.v6 |
| #define addr8 xa.addr8 |
| #define addr32 xa.addr32 |
| }; |
| |
| static int |
| addr_unicast_masklen(int af) |
| { |
| switch (af) { |
| case AF_INET: |
| return 32; |
| case AF_INET6: |
| return 128; |
| default: |
| return -1; |
| } |
| } |
| |
| static inline int |
| masklen_valid(int af, u_int masklen) |
| { |
| switch (af) { |
| case AF_INET: |
| return masklen <= 32 ? 0 : -1; |
| case AF_INET6: |
| return masklen <= 128 ? 0 : -1; |
| default: |
| return -1; |
| } |
| } |
| |
| /* |
| * Convert struct sockaddr to struct xaddr |
| * Returns 0 on success, -1 on failure. |
| */ |
| static int |
| addr_sa_to_xaddr(struct sockaddr *sa, socklen_t slen, struct xaddr *xa) |
| { |
| struct sockaddr_in *in4 = (struct sockaddr_in *)sa; |
| struct sockaddr_in6 *in6 = (struct sockaddr_in6 *)sa; |
| |
| memset(xa, '\0', sizeof(*xa)); |
| |
| switch (sa->sa_family) { |
| case AF_INET: |
| if (slen < (socklen_t)sizeof(*in4)) |
| return -1; |
| xa->af = AF_INET; |
| memcpy(&xa->v4, &in4->sin_addr, sizeof(xa->v4)); |
| break; |
| case AF_INET6: |
| if (slen < (socklen_t)sizeof(*in6)) |
| return -1; |
| xa->af = AF_INET6; |
| memcpy(&xa->v6, &in6->sin6_addr, sizeof(xa->v6)); |
| #ifdef HAVE_STRUCT_SOCKADDR_IN6_SIN6_SCOPE_ID |
| xa->scope_id = in6->sin6_scope_id; |
| #endif |
| break; |
| default: |
| return -1; |
| } |
| |
| return 0; |
| } |
| |
| /* |
| * Calculate a netmask of length 'l' for address family 'af' and |
| * store it in 'n'. |
| * Returns 0 on success, -1 on failure. |
| */ |
| static int |
| addr_netmask(int af, u_int l, struct xaddr *n) |
| { |
| int i; |
| |
| if (masklen_valid(af, l) != 0 || n == NULL) |
| return -1; |
| |
| memset(n, '\0', sizeof(*n)); |
| switch (af) { |
| case AF_INET: |
| n->af = AF_INET; |
| if (l == 0) |
| return 0; |
| n->v4.s_addr = htonl((0xffffffff << (32 - l)) & 0xffffffff); |
| return 0; |
| case AF_INET6: |
| n->af = AF_INET6; |
| for (i = 0; i < 4 && l >= 32; i++, l -= 32) |
| n->addr32[i] = 0xffffffffU; |
| if (i < 4 && l != 0) |
| n->addr32[i] = htonl((0xffffffff << (32 - l)) & |
| 0xffffffff); |
| return 0; |
| default: |
| return -1; |
| } |
| } |
| |
| /* |
| * Perform logical AND of addresses 'a' and 'b', storing result in 'dst'. |
| * Returns 0 on success, -1 on failure. |
| */ |
| static int |
| addr_and(struct xaddr *dst, const struct xaddr *a, const struct xaddr *b) |
| { |
| int i; |
| |
| if (dst == NULL || a == NULL || b == NULL || a->af != b->af) |
| return -1; |
| |
| memcpy(dst, a, sizeof(*dst)); |
| switch (a->af) { |
| case AF_INET: |
| dst->v4.s_addr &= b->v4.s_addr; |
| return 0; |
| case AF_INET6: |
| dst->scope_id = a->scope_id; |
| for (i = 0; i < 4; i++) |
| dst->addr32[i] &= b->addr32[i]; |
| return 0; |
| default: |
| return -1; |
| } |
| } |
| |
| /* |
| * Compare addresses 'a' and 'b' |
| * Return 0 if addresses are identical, -1 if (a < b) or 1 if (a > b) |
| */ |
| static int |
| addr_cmp(const struct xaddr *a, const struct xaddr *b) |
| { |
| int i; |
| |
| if (a->af != b->af) |
| return a->af == AF_INET6 ? 1 : -1; |
| |
| switch (a->af) { |
| case AF_INET: |
| if (a->v4.s_addr == b->v4.s_addr) |
| return 0; |
| return ntohl(a->v4.s_addr) > ntohl(b->v4.s_addr) ? 1 : -1; |
| case AF_INET6: |
| for (i = 0; i < 16; i++) |
| if (a->addr8[i] - b->addr8[i] != 0) |
| return a->addr8[i] > b->addr8[i] ? 1 : -1; |
| if (a->scope_id == b->scope_id) |
| return 0; |
| return a->scope_id > b->scope_id ? 1 : -1; |
| default: |
| return -1; |
| } |
| } |
| |
| /* |
| * Parse string address 'p' into 'n' |
| * Returns 0 on success, -1 on failure. |
| */ |
| static int |
| addr_pton(const char *p, struct xaddr *n) |
| { |
| struct addrinfo hints, *ai = NULL; |
| int ret = -1; |
| |
| memset(&hints, '\0', sizeof(hints)); |
| hints.ai_flags = AI_NUMERICHOST; |
| |
| if (p == NULL || getaddrinfo(p, NULL, &hints, &ai) != 0) |
| goto out; |
| if (ai == NULL || ai->ai_addr == NULL) |
| goto out; |
| if (n != NULL && addr_sa_to_xaddr(ai->ai_addr, ai->ai_addrlen, n) == -1) |
| goto out; |
| /* success */ |
| ret = 0; |
| out: |
| if (ai != NULL) |
| freeaddrinfo(ai); |
| return ret; |
| } |
| |
| /* |
| * Perform bitwise negation of address |
| * Returns 0 on success, -1 on failure. |
| */ |
| static int |
| addr_invert(struct xaddr *n) |
| { |
| int i; |
| |
| if (n == NULL) |
| return (-1); |
| |
| switch (n->af) { |
| case AF_INET: |
| n->v4.s_addr = ~n->v4.s_addr; |
| return (0); |
| case AF_INET6: |
| for (i = 0; i < 4; i++) |
| n->addr32[i] = ~n->addr32[i]; |
| return (0); |
| default: |
| return (-1); |
| } |
| } |
| |
| /* |
| * Calculate a netmask of length 'l' for address family 'af' and |
| * store it in 'n'. |
| * Returns 0 on success, -1 on failure. |
| */ |
| static int |
| addr_hostmask(int af, u_int l, struct xaddr *n) |
| { |
| if (addr_netmask(af, l, n) == -1 || addr_invert(n) == -1) |
| return (-1); |
| return (0); |
| } |
| |
| /* |
| * Test whether address 'a' is all zeros (i.e. 0.0.0.0 or ::) |
| * Returns 0 on if address is all-zeros, -1 if not all zeros or on failure. |
| */ |
| static int |
| addr_is_all0s(const struct xaddr *a) |
| { |
| int i; |
| |
| switch (a->af) { |
| case AF_INET: |
| return (a->v4.s_addr == 0 ? 0 : -1); |
| case AF_INET6:; |
| for (i = 0; i < 4; i++) |
| if (a->addr32[i] != 0) |
| return (-1); |
| return (0); |
| default: |
| return (-1); |
| } |
| } |
| |
| /* |
| * Test whether host portion of address 'a', as determined by 'masklen' |
| * is all zeros. |
| * Returns 0 on if host portion of address is all-zeros, |
| * -1 if not all zeros or on failure. |
| */ |
| static int |
| addr_host_is_all0s(const struct xaddr *a, u_int masklen) |
| { |
| struct xaddr tmp_addr, tmp_mask, tmp_result; |
| |
| memcpy(&tmp_addr, a, sizeof(tmp_addr)); |
| if (addr_hostmask(a->af, masklen, &tmp_mask) == -1) |
| return (-1); |
| if (addr_and(&tmp_result, &tmp_addr, &tmp_mask) == -1) |
| return (-1); |
| return (addr_is_all0s(&tmp_result)); |
| } |
| |
| /* |
| * Parse a CIDR address (x.x.x.x/y or xxxx:yyyy::/z). |
| * Return -1 on parse error, -2 on inconsistency or 0 on success. |
| */ |
| static int |
| addr_pton_cidr(const char *p, struct xaddr *n, u_int *l) |
| { |
| struct xaddr tmp; |
| long unsigned int masklen = 999; |
| char addrbuf[64], *mp, *cp; |
| |
| /* Don't modify argument */ |
| if (p == NULL || strlcpy(addrbuf, p, sizeof(addrbuf)) >= sizeof(addrbuf)) |
| return -1; |
| |
| if ((mp = strchr(addrbuf, '/')) != NULL) { |
| *mp = '\0'; |
| mp++; |
| masklen = strtoul(mp, &cp, 10); |
| if (*mp == '\0' || *cp != '\0' || masklen > 128) |
| return -1; |
| } |
| |
| if (addr_pton(addrbuf, &tmp) == -1) |
| return -1; |
| |
| if (mp == NULL) |
| masklen = addr_unicast_masklen(tmp.af); |
| if (masklen_valid(tmp.af, masklen) == -1) |
| return -2; |
| if (addr_host_is_all0s(&tmp, masklen) != 0) |
| return -2; |
| |
| if (n != NULL) |
| memcpy(n, &tmp, sizeof(*n)); |
| if (l != NULL) |
| *l = masklen; |
| |
| return 0; |
| } |
| |
| static int |
| addr_netmatch(const struct xaddr *host, const struct xaddr *net, u_int masklen) |
| { |
| struct xaddr tmp_mask, tmp_result; |
| |
| if (host->af != net->af) |
| return -1; |
| |
| if (addr_netmask(host->af, masklen, &tmp_mask) == -1) |
| return -1; |
| if (addr_and(&tmp_result, host, &tmp_mask) == -1) |
| return -1; |
| return addr_cmp(&tmp_result, net); |
| } |
| |
| /* |
| * Match "addr" against list pattern list "_list", which may contain a |
| * mix of CIDR addresses and old-school wildcards. |
| * |
| * If addr is NULL, then no matching is performed, but _list is parsed |
| * and checked for well-formedness. |
| * |
| * Returns 1 on match found (never returned when addr == NULL). |
| * Returns 0 on if no match found, or no errors found when addr == NULL. |
| * Returns -1 on negated match found (never returned when addr == NULL). |
| * Returns -2 on invalid list entry. |
| */ |
| int |
| addr_match_list(const char *addr, const char *_list) |
| { |
| char *list, *cp, *o; |
| struct xaddr try_addr, match_addr; |
| u_int masklen, neg; |
| int ret = 0, r; |
| |
| if (addr != NULL && addr_pton(addr, &try_addr) != 0) { |
| debug2("%s: couldn't parse address %.100s", __func__, addr); |
| return 0; |
| } |
| if ((o = list = strdup(_list)) == NULL) |
| return -1; |
| while ((cp = strsep(&list, ",")) != NULL) { |
| neg = *cp == '!'; |
| if (neg) |
| cp++; |
| if (*cp == '\0') { |
| ret = -2; |
| break; |
| } |
| /* Prefer CIDR address matching */ |
| r = addr_pton_cidr(cp, &match_addr, &masklen); |
| if (r == -2) { |
| debug2("%s: inconsistent mask length for " |
| "match network \"%.100s\"", __func__, cp); |
| ret = -2; |
| break; |
| } else if (r == 0) { |
| if (addr != NULL && addr_netmatch(&try_addr, |
| &match_addr, masklen) == 0) { |
| foundit: |
| if (neg) { |
| ret = -1; |
| break; |
| } |
| ret = 1; |
| } |
| continue; |
| } else { |
| /* If CIDR parse failed, try wildcard string match */ |
| if (addr != NULL && match_pattern(addr, cp) == 1) |
| goto foundit; |
| } |
| } |
| free(o); |
| |
| return ret; |
| } |
| |
| /* |
| * Match "addr" against list CIDR list "_list". Lexical wildcards and |
| * negation are not supported. If "addr" == NULL, will verify structure |
| * of "_list". |
| * |
| * Returns 1 on match found (never returned when addr == NULL). |
| * Returns 0 on if no match found, or no errors found when addr == NULL. |
| * Returns -1 on error |
| */ |
| int |
| addr_match_cidr_list(const char *addr, const char *_list) |
| { |
| char *list, *cp, *o; |
| struct xaddr try_addr, match_addr; |
| u_int masklen; |
| int ret = 0, r; |
| |
| if (addr != NULL && addr_pton(addr, &try_addr) != 0) { |
| debug2("%s: couldn't parse address %.100s", __func__, addr); |
| return 0; |
| } |
| if ((o = list = strdup(_list)) == NULL) |
| return -1; |
| while ((cp = strsep(&list, ",")) != NULL) { |
| if (*cp == '\0') { |
| error("%s: empty entry in list \"%.100s\"", |
| __func__, o); |
| ret = -1; |
| break; |
| } |
| |
| /* |
| * NB. This function is called in pre-auth with untrusted data, |
| * so be extra paranoid about junk reaching getaddrino (via |
| * addr_pton_cidr). |
| */ |
| |
| /* Stop junk from reaching getaddrinfo. +3 is for masklen */ |
| if (strlen(cp) > INET6_ADDRSTRLEN + 3) { |
| error("%s: list entry \"%.100s\" too long", |
| __func__, cp); |
| ret = -1; |
| break; |
| } |
| #define VALID_CIDR_CHARS "0123456789abcdefABCDEF.:/" |
| if (strspn(cp, VALID_CIDR_CHARS) != strlen(cp)) { |
| error("%s: list entry \"%.100s\" contains invalid " |
| "characters", __func__, cp); |
| ret = -1; |
| } |
| |
| /* Prefer CIDR address matching */ |
| r = addr_pton_cidr(cp, &match_addr, &masklen); |
| if (r == -1) { |
| error("Invalid network entry \"%.100s\"", cp); |
| ret = -1; |
| break; |
| } else if (r == -2) { |
| error("Inconsistent mask length for " |
| "network \"%.100s\"", cp); |
| ret = -1; |
| break; |
| } else if (r == 0 && addr != NULL) { |
| if (addr_netmatch(&try_addr, &match_addr, |
| masklen) == 0) |
| ret = 1; |
| continue; |
| } |
| } |
| free(o); |
| |
| return ret; |
| } |