~ubuntu-branches/ubuntu/lucid/openssh/lucid

1.13.4 by Colin Watson
Import upstream version 5.2p1
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/*	$OpenBSD: addrmatch.c,v 1.4 2008/12/10 03:55:20 stevesk Exp $ */
1.13.3 by Colin Watson
Import upstream version 5.1p1
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/*
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 * Copyright (c) 2004-2008 Damien Miller <djm@mindrot.org>
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 *
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 * Permission to use, copy, modify, and distribute this software for any
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 * purpose with or without fee is hereby granted, provided that the above
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 * copyright notice and this permission notice appear in all copies.
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 *
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 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
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 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
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 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
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 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
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 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
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 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
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 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
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 */
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19
#include "includes.h"
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21
#include <sys/types.h>
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#include <sys/socket.h>
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#include <netinet/in.h>
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#include <arpa/inet.h>
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26
#include <netdb.h>
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#include <string.h>
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#include <stdlib.h>
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#include <stdio.h>
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#include <stdarg.h>
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32
#include "match.h"
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#include "log.h"
1.13.4 by Colin Watson
Import upstream version 5.2p1
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#include "xmalloc.h"
1.13.3 by Colin Watson
Import upstream version 5.1p1
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struct xaddr {
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	sa_family_t	af;
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	union {
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		struct in_addr		v4;
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		struct in6_addr		v6;
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		u_int8_t		addr8[16];
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		u_int32_t		addr32[4];
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	} xa;		    /* 128-bit address */
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	u_int32_t	scope_id;	/* iface scope id for v6 */
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#define v4	xa.v4
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#define v6	xa.v6
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#define addr8	xa.addr8
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#define addr32	xa.addr32
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};
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51
static int
52
addr_unicast_masklen(int af)
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{
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	switch (af) {
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	case AF_INET:
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		return 32;
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	case AF_INET6:
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		return 128;
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	default:
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		return -1;
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	}
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}
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64
static inline int
65
masklen_valid(int af, u_int masklen)
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{
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	switch (af) {
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	case AF_INET:
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		return masklen <= 32 ? 0 : -1;
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	case AF_INET6:
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		return masklen <= 128 ? 0 : -1;
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	default:
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		return -1;
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	}
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}
76
77
/*
78
 * Convert struct sockaddr to struct xaddr
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 * Returns 0 on success, -1 on failure.
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 */
81
static int
82
addr_sa_to_xaddr(struct sockaddr *sa, socklen_t slen, struct xaddr *xa)
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{
84
	struct sockaddr_in *in4 = (struct sockaddr_in *)sa;
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	struct sockaddr_in6 *in6 = (struct sockaddr_in6 *)sa;
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87
	memset(xa, '\0', sizeof(*xa));
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89
	switch (sa->sa_family) {
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	case AF_INET:
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		if (slen < sizeof(*in4))
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			return -1;
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		xa->af = AF_INET;
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		memcpy(&xa->v4, &in4->sin_addr, sizeof(xa->v4));
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		break;
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	case AF_INET6:
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		if (slen < sizeof(*in6))
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			return -1;
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		xa->af = AF_INET6;
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		memcpy(&xa->v6, &in6->sin6_addr, sizeof(xa->v6));
1.13.4 by Colin Watson
Import upstream version 5.2p1
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#ifdef HAVE_STRUCT_SOCKADDR_IN6_SIN6_SCOPE_ID
1.13.3 by Colin Watson
Import upstream version 5.1p1
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		xa->scope_id = in6->sin6_scope_id;
1.13.4 by Colin Watson
Import upstream version 5.2p1
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#endif
1.13.3 by Colin Watson
Import upstream version 5.1p1
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		break;
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	default:
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		return -1;
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	}
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	return 0;
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}
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112
/*
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 * Calculate a netmask of length 'l' for address family 'af' and
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 * store it in 'n'.
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 * Returns 0 on success, -1 on failure.
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 */
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static int
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addr_netmask(int af, u_int l, struct xaddr *n)
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{
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	int i;
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	if (masklen_valid(af, l) != 0 || n == NULL)
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		return -1;
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125
	memset(n, '\0', sizeof(*n));
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	switch (af) {
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	case AF_INET:
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		n->af = AF_INET;
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		n->v4.s_addr = htonl((0xffffffff << (32 - l)) & 0xffffffff);
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		return 0;
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	case AF_INET6:
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		n->af = AF_INET6;
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		for (i = 0; i < 4 && l >= 32; i++, l -= 32)
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			n->addr32[i] = 0xffffffffU;
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		if (i < 4 && l != 0)
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			n->addr32[i] = htonl((0xffffffff << (32 - l)) &
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			    0xffffffff);
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		return 0;
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	default:
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		return -1;
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	}
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}
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144
/*
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 * Perform logical AND of addresses 'a' and 'b', storing result in 'dst'.
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 * Returns 0 on success, -1 on failure.
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 */
148
static int
149
addr_and(struct xaddr *dst, const struct xaddr *a, const struct xaddr *b)
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{
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	int i;
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153
	if (dst == NULL || a == NULL || b == NULL || a->af != b->af)
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		return -1;
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	memcpy(dst, a, sizeof(*dst));
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	switch (a->af) {
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	case AF_INET:
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		dst->v4.s_addr &= b->v4.s_addr;
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		return 0;
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	case AF_INET6:
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		dst->scope_id = a->scope_id;
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		for (i = 0; i < 4; i++)
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			dst->addr32[i] &= b->addr32[i];
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		return 0;
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	default:
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		return -1;
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	}
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}
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171
/*
172
 * Compare addresses 'a' and 'b'
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 * Return 0 if addresses are identical, -1 if (a < b) or 1 if (a > b)
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 */
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static int
176
addr_cmp(const struct xaddr *a, const struct xaddr *b)
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{
178
	int i;
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180
	if (a->af != b->af)
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		return a->af == AF_INET6 ? 1 : -1;
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183
	switch (a->af) {
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	case AF_INET:
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		if (a->v4.s_addr == b->v4.s_addr)
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			return 0;
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		return ntohl(a->v4.s_addr) > ntohl(b->v4.s_addr) ? 1 : -1;
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	case AF_INET6:
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		for (i = 0; i < 16; i++)
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			if (a->addr8[i] - b->addr8[i] != 0)
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				return a->addr8[i] > b->addr8[i] ? 1 : -1;
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		if (a->scope_id == b->scope_id)
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			return 0;
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		return a->scope_id > b->scope_id ? 1 : -1;
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	default:
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		return -1;
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	}
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}
199
200
/*
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 * Parse string address 'p' into 'n'
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 * Returns 0 on success, -1 on failure.
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 */
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static int
205
addr_pton(const char *p, struct xaddr *n)
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{
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	struct addrinfo hints, *ai;
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	memset(&hints, '\0', sizeof(hints));
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	hints.ai_flags = AI_NUMERICHOST;
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	if (p == NULL || getaddrinfo(p, NULL, &hints, &ai) != 0)
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		return -1;
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	if (ai == NULL || ai->ai_addr == NULL)
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		return -1;
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	if (n != NULL &&
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	    addr_sa_to_xaddr(ai->ai_addr, ai->ai_addrlen, n) == -1) {
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		freeaddrinfo(ai);
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		return -1;
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	}
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	freeaddrinfo(ai);
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	return 0;
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}
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/*
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 * Perform bitwise negation of address
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 * Returns 0 on success, -1 on failure.
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 */
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static int
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addr_invert(struct xaddr *n)
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{
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	int i;
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	if (n == NULL)
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		return (-1);
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	switch (n->af) {
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	case AF_INET:
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		n->v4.s_addr = ~n->v4.s_addr;
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		return (0);
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	case AF_INET6:
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		for (i = 0; i < 4; i++)
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			n->addr32[i] = ~n->addr32[i];
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		return (0);
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	default:
249
		return (-1);
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	}
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}
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/*
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 * Calculate a netmask of length 'l' for address family 'af' and
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 * store it in 'n'.
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 * Returns 0 on success, -1 on failure.
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 */
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static int
259
addr_hostmask(int af, u_int l, struct xaddr *n)
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{
261
	if (addr_netmask(af, l, n) == -1 || addr_invert(n) == -1)
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		return (-1);
263
	return (0);
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}
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266
/*
267
 * Test whether address 'a' is all zeros (i.e. 0.0.0.0 or ::)
268
 * Returns 0 on if address is all-zeros, -1 if not all zeros or on failure.
269
 */
270
static int
271
addr_is_all0s(const struct xaddr *a)
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{
273
	int i;
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275
	switch (a->af) {
276
	case AF_INET:
277
		return (a->v4.s_addr == 0 ? 0 : -1);
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	case AF_INET6:;
279
		for (i = 0; i < 4; i++)
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			if (a->addr32[i] != 0)
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				return (-1);
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		return (0);
283
	default:
284
		return (-1);
285
	}
286
}
287
288
/*
289
 * Test whether host portion of address 'a', as determined by 'masklen'
290
 * is all zeros.
291
 * Returns 0 on if host portion of address is all-zeros,
292
 * -1 if not all zeros or on failure.
293
 */
294
static int
295
addr_host_is_all0s(const struct xaddr *a, u_int masklen)
296
{
297
	struct xaddr tmp_addr, tmp_mask, tmp_result;
298
299
	memcpy(&tmp_addr, a, sizeof(tmp_addr));
300
	if (addr_hostmask(a->af, masklen, &tmp_mask) == -1)
301
		return (-1);
302
	if (addr_and(&tmp_result, &tmp_addr, &tmp_mask) == -1)
303
		return (-1);
304
	return (addr_is_all0s(&tmp_result));
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}
306
307
/*
308
 * Parse a CIDR address (x.x.x.x/y or xxxx:yyyy::/z).
309
 * Return -1 on parse error, -2 on inconsistency or 0 on success.
310
 */
311
static int
312
addr_pton_cidr(const char *p, struct xaddr *n, u_int *l)
313
{
314
	struct xaddr tmp;
315
	long unsigned int masklen = 999;
316
	char addrbuf[64], *mp, *cp;
317
318
	/* Don't modify argument */
319
	if (p == NULL || strlcpy(addrbuf, p, sizeof(addrbuf)) > sizeof(addrbuf))
320
		return -1;
321
322
	if ((mp = strchr(addrbuf, '/')) != NULL) {
323
		*mp = '\0';
324
		mp++;
325
		masklen = strtoul(mp, &cp, 10);
326
		if (*mp == '\0' || *cp != '\0' || masklen > 128)
327
			return -1;
328
	}
329
330
	if (addr_pton(addrbuf, &tmp) == -1)
331
		return -1;
332
333
	if (mp == NULL)
334
		masklen = addr_unicast_masklen(tmp.af);
335
	if (masklen_valid(tmp.af, masklen) == -1)
336
		return -2;
337
	if (addr_host_is_all0s(&tmp, masklen) != 0)
338
		return -2;
339
340
	if (n != NULL)
341
		memcpy(n, &tmp, sizeof(*n));
342
	if (l != NULL)
343
		*l = masklen;
344
345
	return 0;
346
}
347
348
static int
349
addr_netmatch(const struct xaddr *host, const struct xaddr *net, u_int masklen)
350
{
351
	struct xaddr tmp_mask, tmp_result;
352
353
	if (host->af != net->af)
354
		return -1;
355
356
	if (addr_netmask(host->af, masklen, &tmp_mask) == -1)
357
		return -1;
358
	if (addr_and(&tmp_result, host, &tmp_mask) == -1)
359
		return -1;
360
	return addr_cmp(&tmp_result, net);
361
}
362
363
/*
364
 * Match "addr" against list pattern list "_list", which may contain a
365
 * mix of CIDR addresses and old-school wildcards.
366
 *
367
 * If addr is NULL, then no matching is performed, but _list is parsed
368
 * and checked for well-formedness.
369
 *
370
 * Returns 1 on match found (never returned when addr == NULL).
371
 * Returns 0 on if no match found, or no errors found when addr == NULL.
372
 * Returns -1 on negated match found (never returned when addr == NULL).
373
 * Returns -2 on invalid list entry.
374
 */
375
int
376
addr_match_list(const char *addr, const char *_list)
377
{
378
	char *list, *cp, *o;
379
	struct xaddr try_addr, match_addr;
380
	u_int masklen, neg;
381
	int ret = 0, r;
382
383
	if (addr != NULL && addr_pton(addr, &try_addr) != 0) {
384
		debug2("%s: couldn't parse address %.100s", __func__, addr);
385
		return 0;
386
	}
387
	if ((o = list = strdup(_list)) == NULL)
388
		return -1;
389
	while ((cp = strsep(&list, ",")) != NULL) {
390
		neg = *cp == '!';
391
		if (neg)
392
			cp++;
393
		if (*cp == '\0') {
394
			ret = -2;
395
			break;
396
		}
397
		/* Prefer CIDR address matching */
398
		r = addr_pton_cidr(cp, &match_addr, &masklen);
399
		if (r == -2) {
400
			error("Inconsistent mask length for "
401
			    "network \"%.100s\"", cp);
402
			ret = -2;
403
			break;
404
		} else if (r == 0) {
405
			if (addr != NULL && addr_netmatch(&try_addr,
406
                           &match_addr, masklen) == 0) {
407
 foundit:
408
				if (neg) {
409
					ret = -1;
410
					break;
411
				}
412
				ret = 1;
413
			}
414
			continue;
415
		} else {
416
			/* If CIDR parse failed, try wildcard string match */
417
			if (addr != NULL && match_pattern(addr, cp) == 1)
418
				goto foundit;
419
		}
420
	}
1.13.4 by Colin Watson
Import upstream version 5.2p1
421
	xfree(o);
1.13.3 by Colin Watson
Import upstream version 5.1p1
422
423
	return ret;
424
}