inet/ether_line.c

   1 /* Copyright (C) 1996,1999,2002,2007 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   for (size_t cnt = 0; cnt < 6; ++cnt)
  30     {
  31       unsigned int number;
  32       char ch;
  33
  34       ch = _tolower (*line++);
  35       if ((ch < '0' || ch > '9') && (ch < 'a' || ch > 'f'))
  36         return -1;
  37       number = isdigit (ch) ? (ch - '0') : (ch - 'a' + 10);
  38
  39       ch = _tolower (*line);
  40       if ((cnt < 5 && ch != ':') || (cnt == 5 && ch != '\0' && !isspace (ch)))
  41         {
  42           ++line;
  43           if ((ch < '0' || ch > '9') && (ch < 'a' || ch > 'f'))
  44             return -1;
  45           number <<= 4;
  46           number += isdigit (ch) ? (ch - '0') : (ch - 'a' + 10);
  47
  48           ch = *line;
  49           if (cnt < 5 && ch != ':')
  50             return -1;
  51         }
  52
  53       /* Store result.  */
  54       addr->ether_addr_octet[cnt] = (unsigned char) number;
  55
  56       /* Skip ':'.  */
  57       if (ch != '\0')
  58         ++line;
  59     }
  60
  61   /* Skip initial whitespace.  */
  62   while (isspace (*line))
  63     ++line;
  64
  65   if (*line == '#' || *line == '\0')
  66     /* No hostname.  */
  67     return -1;
  68
  69   /* The hostname is up to the next non-space character.  */
  70   /* XXX This can cause trouble because the hostname might be too long
  71      but we have no possibility to check it here.  */
  72   while (*line != '\0' && *line != '#' && !isspace (*line))
  73     *hostname++ = *line++;
  74   *hostname = '\0';
  75
  76   return 0;
  77 }