getethertype.c

/*
* 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 "ethernetdb.h"

#define  MAXALIASES  35

static FILE *etherf = NULL;
static char line[BUFSIZ + 1];
static struct ethertypeent et_ent;
static char *ethertype_aliases[MAXALIASES];
static int ethertype_stayopen;

void setethertypeent(int f)
{
   if (etherf == NULL)
      etherf = fopen(_PATH_ETHERTYPES, "r");
   else
      rewind(etherf);
   ethertype_stayopen |= f;
}

void endethertypeent(void)
{
   if (etherf) {
      fclose(etherf);
      etherf = NULL;
   }
   ethertype_stayopen = 0;
}

struct ethertypeent *getethertypeent(void)
{
   char *e;
   char *endptr;
   register char *cp, **q;

   if (etherf == NULL
       && (etherf = fopen(_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 ethertypeent *getethertypebyname(const char *name)
{
   register struct 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 ethertypeent *getethertypebynumber(int type)
{
   register struct ethertypeent *e;

   setethertypeent(ethertype_stayopen);
   while ((e = getethertypeent()) != NULL)
      if (e->e_ethertype == type)
         break;
   if (!ethertype_stayopen)
      endethertypeent();
   return (e);
}