getethertype.c

   1 /*
   2 * getethertype.c
   3 *
   4 * This file was part of the NYS Library.
   5 *
   6 ** The NYS Library is free software; you can redistribute it and/or
   7 ** modify it under the terms of the GNU Library General Public License as
   8 ** published by the Free Software Foundation; either version 2 of the
   9 ** License, or (at your option) any later version.
  10 *
  11 * This program is free software; you can redistribute it and/or modify
  12 * it under the terms of the GNU General Public License as published by
  13 * the Free Software Foundation; either version 2 of the License, or
  14 * (at your option) any later version.
  15 *
  16 * This program is distributed in the hope that it will be useful,
  17 * but WITHOUT ANY WARRANTY; without even the implied warranty of
  18 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  19 * GNU General Public License for more details.
  20 *
  21 * You should have received a copy of the GNU General Public License
  22 * along with this program; if not, write to the Free Software
  23 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  24 */
  25
  26 /********************************************************************
  27 * Description: Ethertype name service switch and the ethertypes
  28 * database access functions
  29 * Author: Nick Fedchik <fnm@ukrsat.com>
  30 * Checker: Bart De Schuymer <bdschuym@pandora.be>
  31 * Origin: uClibc-0.9.16/libc/inet/getproto.c
  32 * Created at: Mon Nov 11 12:20:11 EET 2002
  33 ********************************************************************/
  34
  35
  36 #include <ctype.h>
  37 #include <features.h>
  38 #include <sys/types.h>
  39 #include <sys/socket.h>
  40 #include <netdb.h>
  41 #include <stdio.h>
  42 #include <stdlib.h>
  43 #include <string.h>
  44 #include <netinet/ether.h>
  45 #include <net/ethernet.h>
  46
  47 #include "ethernetdb.h"
  48
  49 #define MAXALIASES      35
  50
  51 static FILE *etherf = NULL;
  52 static char line[BUFSIZ + 1];
  53 static struct ethertypeent et_ent;
  54 static char *ethertype_aliases[MAXALIASES];
  55 static int ethertype_stayopen;
  56
  57 void setethertypeent(int f)
  58 {
  59         if (etherf == NULL)
  60                 etherf = fopen(_PATH_ETHERTYPES, "r");
  61         else
  62                 rewind(etherf);
  63         ethertype_stayopen |= f;
  64 }
  65
  66 void endethertypeent(void)
  67 {
  68         if (etherf) {
  69                 fclose(etherf);
  70                 etherf = NULL;
  71         }
  72         ethertype_stayopen = 0;
  73 }
  74
  75 struct ethertypeent *getethertypeent(void)
  76 {
  77         char *e;
  78         char *endptr;
  79         register char *cp, **q;
  80
  81         if (etherf == NULL
  82             && (etherf = fopen(_PATH_ETHERTYPES, "r")) == NULL) {
  83                 return (NULL);
  84         }
  85
  86 again:
  87         if ((e = fgets(line, BUFSIZ, etherf)) == NULL) {
  88                 return (NULL);
  89         }
  90         if (*e == '#')
  91                 goto again;
  92         cp = strpbrk(e, "#\n");
  93         if (cp == NULL)
  94                 goto again;
  95         *cp = '\0';
  96         et_ent.e_name = e;
  97         cp = strpbrk(e, " \t");
  98         if (cp == NULL)
  99                 goto again;
 100         *cp++ = '\0';
 101         while (*cp == ' ' || *cp == '\t')
 102                 cp++;
 103         e = strpbrk(cp, " \t");
 104         if (e != NULL)
 105                 *e++ = '\0';
 106 // Check point
 107         et_ent.e_ethertype = strtol(cp, &endptr, 16);
 108         if (*endptr != '\0'
 109             || (et_ent.e_ethertype < ETH_ZLEN
 110                 || et_ent.e_ethertype > 0xFFFF))
 111                 goto again;     // Skip invalid etherproto type entry
 112         q = et_ent.e_aliases = ethertype_aliases;
 113         if (e != NULL) {
 114                 cp = e;
 115                 while (cp && *cp) {
 116                         if (*cp == ' ' || *cp == '\t') {
 117                                 cp++;
 118                                 continue;
 119                         }
 120                         if (q < &ethertype_aliases[MAXALIASES - 1])
 121                                 *q++ = cp;
 122                         cp = strpbrk(cp, " \t");
 123                         if (cp != NULL)
 124                                 *cp++ = '\0';
 125                 }
 126         }
 127         *q = NULL;
 128         return (&et_ent);
 129 }
 130
 131
 132 struct ethertypeent *getethertypebyname(const char *name)
 133 {
 134         register struct ethertypeent *e;
 135         register char **cp;
 136
 137         setethertypeent(ethertype_stayopen);
 138         while ((e = getethertypeent()) != NULL) {
 139                 if (strcasecmp(e->e_name, name) == 0)
 140                         break;
 141                 for (cp = e->e_aliases; *cp != 0; cp++)
 142                         if (strcasecmp(*cp, name) == 0)
 143                                 goto found;
 144         }
 145 found:
 146         if (!ethertype_stayopen)
 147                 endethertypeent();
 148         return (e);
 149 }
 150
 151 struct ethertypeent *getethertypebynumber(int type)
 152 {
 153         register struct ethertypeent *e;
 154
 155         setethertypeent(ethertype_stayopen);
 156         while ((e = getethertypeent()) != NULL)
 157                 if (e->e_ethertype == type)
 158                         break;
 159         if (!ethertype_stayopen)
 160                 endethertypeent();
 161         return (e);
 162 }