diff options
Diffstat (limited to 'addrmatch.c')
| -rw-r--r-- | addrmatch.c | 169 |
1 files changed, 169 insertions, 0 deletions
diff --git a/addrmatch.c b/addrmatch.c new file mode 100644 index 0000000..b0dc096 --- /dev/null +++ b/addrmatch.c @@ -0,0 +1,169 @@ +/* $OpenBSD: addrmatch.c,v 1.17 2021/04/03 06:18:40 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 "addr.h" +#include "match.h" +#include "log.h" + +/* + * 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_f("couldn't parse address %.100s", 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_f("inconsistent mask length for " + "match network \"%.100s\"", 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_f("couldn't parse address %.100s", addr); + return 0; + } + if ((o = list = strdup(_list)) == NULL) + return -1; + while ((cp = strsep(&list, ",")) != NULL) { + if (*cp == '\0') { + error_f("empty entry in list \"%.100s\"", 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_f("list entry \"%.100s\" too long", cp); + ret = -1; + break; + } +#define VALID_CIDR_CHARS "0123456789abcdefABCDEF.:/" + if (strspn(cp, VALID_CIDR_CHARS) != strlen(cp)) { + error_f("list entry \"%.100s\" contains invalid " + "characters", 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; +} |