/*

* getethertype.c

*

* This file was 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.

*

* This program is free software; you can redistribute it and/or modify

* it under the terms of the GNU General Public License as published by

* the Free Software Foundation; either version 2 of the License, or

* (at your option) any later version.

*

* This program 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 General Public License for more details.

*

* You should have received a copy of the GNU General Public License

* along with this program; if not, write to the Free Software

* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA

*/

/********************************************************************

* Description: Ethertype name service switch and the ethertypes 

* database access functions

* Author: Nick Fedchik <fnm@ukrsat.com>

* Checker: Bart De Schuymer <bdschuym@pandora.be>

* Origin: uClibc-0.9.16/libc/inet/getproto.c

* Created at: Mon Nov 11 12:20:11 EET 2002

********************************************************************/

#include <ctype.h>

#include <features.h>

#include <sys/types.h>

#include <sys/socket.h>

#include <netdb.h>

#include <stdio.h>

#include <stdlib.h>

#include <string.h>

#include <netinet/ether.h>

#include <net/ethernet.h>

#include <xtables.h>

#define	MAXALIASES	35

static FILE *etherf = NULL;

static char line[BUFSIZ + 1];

static struct xt_ethertypeent et_ent;

static char *ethertype_aliases[MAXALIASES];

static int ethertype_stayopen;

static void setethertypeent(int f)

{

	if (etherf == NULL)

		etherf = fopen(XT_PATH_ETHERTYPES, "r");

	else

		rewind(etherf);

	ethertype_stayopen |= f;

}

static void endethertypeent(void)

{

	if (etherf) {

		fclose(etherf);

		etherf = NULL;

	}

	ethertype_stayopen = 0;

}

static struct xt_ethertypeent *getethertypeent(void)

{

	char *e;

	char *endptr;

	register char *cp, **q;

	if (etherf == NULL

	    && (etherf = fopen(XT_PATH_ETHERTYPES, "r")) == NULL) {

		return (NULL);

	}

again:

	if ((e = fgets(line, BUFSIZ, etherf)) == NULL) {

		return (NULL);

	}

	if (*e == '#')

		goto again;

	cp = strpbrk(e, "#\n");

	if (cp == NULL)

		goto again;

	*cp = '\0';

	et_ent.e_name = e;

	cp = strpbrk(e, " \t");

	if (cp == NULL)

		goto again;

	*cp++ = '\0';

	while (*cp == ' ' || *cp == '\t')

		cp++;

	e = strpbrk(cp, " \t");

	if (e != NULL)

		*e++ = '\0';

// Check point

	et_ent.e_ethertype = strtol(cp, &endptr, 16);

	if (*endptr != '\0'

	    || (et_ent.e_ethertype < ETH_ZLEN

		|| et_ent.e_ethertype > 0xFFFF))

		goto again;	// Skip invalid etherproto type entry

	q = et_ent.e_aliases = ethertype_aliases;

	if (e != NULL) {

		cp = e;

		while (cp && *cp) {

			if (*cp == ' ' || *cp == '\t') {

				cp++;

				continue;

			}

			if (q < &ethertype_aliases[MAXALIASES - 1])

				*q++ = cp;

			cp = strpbrk(cp, " \t");

			if (cp != NULL)

				*cp++ = '\0';

		}

	}

	*q = NULL;

	return (&et_ent);

}

struct xt_ethertypeent *xtables_getethertypebyname(const char *name)

{

	register struct xt_ethertypeent *e;

	register char **cp;

	setethertypeent(ethertype_stayopen);

	while ((e = getethertypeent()) != NULL) {

		if (strcasecmp(e->e_name, name) == 0)

			break;

		for (cp = e->e_aliases; *cp != 0; cp++)

			if (strcasecmp(*cp, name) == 0)

				goto found;

	}

found:

	if (!ethertype_stayopen)

		endethertypeent();

	return (e);

}

struct xt_ethertypeent *xtables_getethertypebynumber(int type)

{

	register struct xt_ethertypeent *e;

	setethertypeent(ethertype_stayopen);

	while ((e = getethertypeent()) != NULL)

		if (e->e_ethertype == type)

			break;

	if (!ethertype_stayopen)

		endethertypeent();

	return (e);

}