addrmatch.c - third_party/openssh-portable - Git at Google

 /*	$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;
 }
	/* $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;
	}