lib/ether.c

   1 /*
   2  * lib/ether.c        This file contains an implementation of the "Ethernet"
   3  *              support functions.
   4  *
   5  * Version:     $Id: ether.c,v 1.8 2002/07/30 05:17:29 ecki Exp $
   6  *
   7  * Author:      Fred N. van Kempen, <waltje@uwalt.nl.mugnet.org>
   8  *              Copyright 1993 MicroWalt Corporation
   9  *
  10  *              This program is free software; you can redistribute it
  11  *              and/or  modify it under  the terms of  the GNU General
  12  *              Public  License as  published  by  the  Free  Software
  13  *              Foundation;  either  version 2 of the License, or  (at
  14  *              your option) any later version.
  15  */
  16 #include "config.h"
  17
  18 #if HAVE_HWETHER
  19 #include <sys/types.h>
  20 #include <sys/socket.h>
  21 #include <net/if_arp.h>
  22 #include <linux/if_ether.h>
  23 #include <stdlib.h>
  24 #include <stdio.h>
  25 #include <errno.h>
  26 #include <ctype.h>
  27 #include <string.h>
  28 #include <unistd.h>
  29 #include "net-support.h"
  30 #include "pathnames.h"
  31 #include "intl.h"
  32 #include "util.h"
  33
  34 extern struct hwtype ether_hwtype;
  35
  36
  37 /* Display an Ethernet address in readable format. */
  38 static char *pr_ether(unsigned char *ptr)
  39 {
  40     static char buff[64];
  41
  42     snprintf(buff, sizeof(buff), "%02x:%02x:%02x:%02x:%02x:%02x",
  43              (ptr[0] & 0377), (ptr[1] & 0377), (ptr[2] & 0377),
  44              (ptr[3] & 0377), (ptr[4] & 0377), (ptr[5] & 0377)
  45         );
  46     return (buff);
  47 }
  48
  49
  50 /* Input an Ethernet address and convert to binary. */
  51 static int in_ether(char *bufp, struct sockaddr *sap)
  52 {
  53     unsigned char *ptr;
  54     char c, *orig;
  55     int i;
  56     unsigned val;
  57
  58     sap->sa_family = ether_hwtype.type;
  59     ptr = sap->sa_data;
  60
  61     i = 0;
  62     orig = bufp;
  63     while ((*bufp != '\0') && (i < ETH_ALEN)) {
  64         val = 0;
  65         c = *bufp++;
  66         if (isdigit(c))
  67             val = c - '0';
  68         else if (c >= 'a' && c <= 'f')
  69             val = c - 'a' + 10;
  70         else if (c >= 'A' && c <= 'F')
  71             val = c - 'A' + 10;
  72         else {
  73 #ifdef DEBUG
  74             fprintf(stderr, _("in_ether(%s): invalid ether address!\n"), orig);
  75 #endif
  76             errno = EINVAL;
  77             return (-1);
  78         }
  79         val <<= 4;
  80         c = *bufp;
  81         if (isdigit(c))
  82             val |= c - '0';
  83         else if (c >= 'a' && c <= 'f')
  84             val |= c - 'a' + 10;
  85         else if (c >= 'A' && c <= 'F')
  86             val |= c - 'A' + 10;
  87         else if (c == ':' || c == 0)
  88             val >>= 4;
  89         else {
  90 #ifdef DEBUG
  91             fprintf(stderr, _("in_ether(%s): invalid ether address!\n"), orig);
  92 #endif
  93             errno = EINVAL;
  94             return (-1);
  95         }
  96         if (c != 0)
  97             bufp++;
  98         *ptr++ = (unsigned char) (val & 0377);
  99         i++;
 100
 101         /* We might get a semicolon here - not required. */
 102         if (*bufp == ':') {
 103             if (i == ETH_ALEN) {
 104 #ifdef DEBUG
 105                 fprintf(stderr, _("in_ether(%s): trailing : ignored!\n"),
 106                         orig)
 107 #endif
 108                     ;           /* nothing */
 109             }
 110             bufp++;
 111         }
 112     }
 113
 114     /* That's it.  Any trailing junk? */
 115     if ((i == ETH_ALEN) && (*bufp != '\0')) {
 116 #ifdef DEBUG
 117         fprintf(stderr, _("in_ether(%s): trailing junk!\n"), orig);
 118         errno = EINVAL;
 119         return (-1);
 120 #endif
 121     }
 122 #ifdef DEBUG
 123     fprintf(stderr, "in_ether(%s): %s\n", orig, pr_ether(sap->sa_data));
 124 #endif
 125
 126     return (0);
 127 }
 128
 129
 130 struct hwtype ether_hwtype =
 131 {
 132     "ether", NULL, /*"10Mbps Ethernet", */ ARPHRD_ETHER, ETH_ALEN,
 133     pr_ether, in_ether, NULL
 134 };
 135
 136
 137 #endif                          /* HAVE_HWETHER */