/*	$OpenBSD: addrmatch.c,v 1.13 2016/09/21 16:55:42 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;

	memset(&hints, '\0', sizeof(hints));
	hints.ai_flags = AI_NUMERICHOST;

	if (p == NULL || getaddrinfo(p, NULL, &hints, &ai) != 0)
		return -1;

	if (ai == NULL || ai->ai_addr == NULL)
		return -1;

	if (n != NULL &&
	    addr_sa_to_xaddr(ai->ai_addr, ai->ai_addrlen, n) == -1) {
		freeaddrinfo(ai);
		return -1;
	}

	freeaddrinfo(ai);
	return 0;
}

/*
 * Perform bitwise negation of ad