inet/ether_line.c

   1 /* Copyright (C) 1996, 1999, 2002 Free Software Foundation, Inc.
   2    This file is part of the GNU C Library.
   3
   4    The GNU C Library is free software; you can redistribute it and/or
   5    modify it under the terms of the GNU Lesser General Public
   6    License as published by the Free Software Foundation; either
   7    version 2.1 of the License, or (at your option) any later version.
   8
   9    The GNU C Library is distributed in the hope that it will be useful,
  10    but WITHOUT ANY WARRANTY; without even the implied warranty of
  11    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  12    Lesser General Public License for more details.
  13
  14    You should have received a copy of the GNU Lesser General Public
  15    License along with the GNU C Library; if not, write to the Free
  16    Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
  17    02111-1307 USA.  */
  18
  19 #include <ctype.h>
  20 #include <stdlib.h>
  21 #include <string.h>
  22 #include <netinet/ether.h>
  23 #include <netinet/if_ether.h>
  24
  25
  26 int
  27 ether_line (const char *line, struct ether_addr *addr, char *hostname)
  28 {
  29   size_t cnt;
  30   char *cp;
  31
  32   for (cnt = 0; cnt < 6; ++cnt)
  33     {
  34       unsigned int number;
  35       char ch;
  36
  37       ch = _tolower (*line++);
  38       if ((ch < '0' || ch > '9') && (ch < 'a' || ch > 'f'))
  39         return -1;
  40       number = isdigit (ch) ? (ch - '0') : (ch - 'a' + 10);
  41
  42       ch = _tolower (*line);
  43       if ((cnt < 5 && ch != ':') || (cnt == 5 && ch != '\0' && !isspace (ch)))
  44         {
  45           ++line;
  46           if ((ch < '0' || ch > '9') && (ch < 'a' || ch > 'f'))
  47             return -1;
  48           number <<= 4;
  49           number += isdigit (ch) ? (ch - '0') : (ch - 'a' + 10);
  50
  51           ch = *line;
  52           if (cnt < 5 && ch != ':')
  53             return -1;
  54         }
  55
  56       /* Store result.  */
  57       addr->ether_addr_octet[cnt] = (unsigned char) number;
  58
  59       /* Skip ':'.  */
  60       if (ch != '\0')
  61         ++line;
  62     }
  63
  64   /* Remove trailing white space.  */
  65   cp = __strchrnul (line, '#');
  66   while (cp > line && isspace (cp[-1]))
  67     --cp;
  68
  69   if (cp == line)
  70     /* No hostname.  */
  71     return -1;
  72
  73   /* XXX This can cause trouble because the hostname might be too long
  74      but we have no possibility to check it here.  */
  75   memcpy (hostname, line, cp - line);
  76   hostname [cp - line] = '\0';
  77
  78   return 0;
  79 }