/*
** protocols.c                           /etc/protocols access functions
**
** This file is part of the NYS Library.
**
** The NYS Library is free software; you can redistribute it and/or
** modify it under the terms of the GNU Library General Public License as
** published by the Free Software Foundation; either version 2 of the
** License, or (at your option) any later version.
**
** The NYS Library is distributed in the hope that it will be useful,
** but WITHOUT ANY WARRANTY; without even the implied warranty of
** MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
** Library General Public License for more details.
** 
** You should have received a copy of the GNU Library General Public
** License along with the NYS Library; see the file COPYING.LIB.  If
** not, write to the Free Software Foundation, Inc., 675 Mass Ave,
** Cambridge, MA 02139, USA.
**
**
** Copyright (c) 1983 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. All advertising materials mentioning features or use of this software
**    must display the following acknowledgement:
**	This product includes software developed by the University of
**	California, Berkeley and its contributors.
** 4. 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.
*/

#define __FORCE_GLIBC
#include <features.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <netdb.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>

#define	MAXALIASES	35

static FILE *protof = NULL;
static char line[BUFSIZ+1];
static struct protoent proto;
static char *proto_aliases[MAXALIASES];
static int proto_stayopen;

void setprotoent(int f)
{
	if (protof == NULL)
		protof = fopen(_PATH_PROTOCOLS, "r" );
	else
		rewind(protof);
	proto_stayopen |= f;
}

void endprotoent(void)
{
	if (protof) {
		fclose(protof);
		protof = NULL;
	}
	proto_stayopen = 0;
}

struct protoent * getprotoent(void)
{
	char *p;
	register char *cp, **q;

	if (protof == NULL && (protof = fopen(_PATH_PROTOCOLS, "r" )) == NULL)
		return (NULL);
again:
	if ((p = fgets(line, BUFSIZ, protof)) == NULL)
		return (NULL);
	if (*p == '#')
		goto again;
	cp = strpbrk(p, "#\n");
	if (cp == NULL)
		goto again;
	*cp = '\0';
	proto.p_name = p;
	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';
	proto.p_proto = atoi(cp);
	q = proto.p_aliases = proto_aliases;
	if (p != NULL) {
		cp = p;
		while (cp && *cp) {
			if (*cp == ' ' || *cp == '\t') {
				cp++;
				continue;
			}
			if (q < &proto_aliases[MAXALIASES - 1])
				*q++ = cp;
			cp = strpbrk(cp, " \t");
			if (cp != NULL)
				*cp++ = '\0';
		}
	}
	*q = NULL;
	return (&proto);
}


struct protoent * getprotobyname(const char *name)
{
	register struct protoent *p;
	register char **cp;

	setprotoent(proto_stayopen);
	while ((p = getprotoent()) != NULL) {
		if (strcmp(p->p_name, name) == 0)
			break;
		for (cp = p->p_aliases; *cp != 0; cp++)
			if (strcmp(*cp, name) == 0)
				goto found;
	}
found:
	if (!proto_stayopen)
		endprotoent();
	return (p);
}

struct protoent * getprotobynumber(int proto)
{
	register struct protoent *p;

	setprotoent(proto_stayopen);
	while ((p = getprotoent()) != NULL)
		if (p->p_proto == proto)
			break;
	if (!proto_stayopen)
		endprotoent();
	return (p);
}