/*	$NetBSD: getport.c,v 1.2 2008/04/28 20:24:14 martin Exp $	*/

/*-
 * Copyright (c) 2004 The NetBSD Foundation, Inc.
 * All rights reserved.
 *
 * This code is derived from software contributed to The NetBSD Foundation
 * by Christos Zoulas.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
 * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
 * POSSIBILITY OF SUCH DAMAGE.
 */

#include <sys/cdefs.h>
__RCSID("$NetBSD: getport.c,v 1.2 2008/04/28 20:24:14 martin Exp $");

#include <stdlib.h>
#include <err.h>
#include <netdb.h>
#include <limits.h>
#include <errno.h>
#include <netinet/in.h>

#include "getport.h"

struct servent *
getport(const char *service, const char *protocol)
{
	long port;
	char *ep;
	struct servent *sp = getservbyname(service, protocol);
	if (sp != NULL)
		return sp;

	if ((sp = calloc(1, sizeof(*sp))) == NULL)
		err(1, "malloc");
	sp->s_name = __UNCONST(service);
	sp->s_proto = __UNCONST(protocol);
	port = strtol(service, &ep, 0);
	if ((service[0] != '\0' && *ep != '\0') ||
	    (errno == ERANGE &&
	    (port == LONG_MAX || port == LONG_MIN)) ||
	    (port <= 0 || port >= IPPORT_ANONMAX))
		errx(1,"port must be between 1 and %d",
		    IPPORT_ANONMAX);
	sp->s_port = htons((uint16_t)port);
	return sp;
}