/*	$OpenBSD: getnetent.c,v 1.17 2015/01/16 18:20:14 millert Exp $ */
/*
 * Copyright (c) 1983, 1993
 *	The Regents of the University of California.  All rights reserved.
 *
 * 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.
 * 3. Neither the name of the University nor the names of its contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE REGENTS 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 REGENTS 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/socket.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#include <netdb.h>
#include <stdio.h>
#include <string.h>
#include <limits.h>

#define	MAXALIASES	35

static FILE *netf;
static char line[BUFSIZ+1];
static struct netent net;
static char *net_aliases[MAXALIASES];
int _net_stayopen;

void
setnetent(int f)
{
	if (netf == NULL)
		netf = fopen(_PATH_NETWORKS, "re" );
	else
		rewind(netf);
	_net_stayopen |= f;
}

void
endnetent(void)
{
	if (netf) {
		fclose(netf);
		netf = NULL;
	}
	_net_stayopen = 0;
}

struct netent *
getnetent(void)
{
	char *p, *cp, **q;
	size_t len;

	if (netf == NULL && (netf = fopen(_PATH_NETWORKS, "re" )) == NULL)
		return (NULL);
again:
	if ((p = fgetln(netf, &len)) == NULL)
		return (NULL);
	if (p[len-1] == '\n')
		len--;
	if (len >= sizeof(line) || len == 0)
		goto again;
	p = memcpy(line, p, len);
	line[len] = '\0';
	if (*p == '#')
		goto again;
	if ((cp = strchr(p, '#')) != NULL)
		*cp = '\0';
	net.n_name = p;
	if (strlen(net.n_name) > HOST_NAME_MAX)
		net.n_name[HOST_NAME_MAX] = '\0';
	cp = strpbrk(p, " \t");
	if (cp == NULL)
		goto again;
	*cp++ = '\0';
	while (*cp == ' ' || *cp == '\t')
		cp++;
	p = strpbrk(cp, " \t");
	if (p != NULL)
		*p++ = '\0';
	net.n_net = inet_network(cp);
	net.n_addrtype = AF_INET;
	q = net.n_aliases = net_aliases;
	cp = p;
	while (cp && *cp) {
		if (*cp == ' ' || *cp == '\t') {
			cp++;
			continue;
		}
		if (q < &net_aliases[MAXALIASES - 1]) {
			*q++ = cp;
			if (strlen(cp) > HOST_NAME_MAX)
				cp[HOST_NAME_MAX] = '\0';
		}
		cp = strpbrk(cp, " \t");
		if (cp != NULL)
			*cp++ = '\0';
	}
	*q = NULL;
	return (&net);
}