1  /* Copyright (C) 1996-2023 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, see
      16     <https://www.gnu.org/licenses/>.  */
      17  
      18  #include <ctype.h>
      19  #include <stdlib.h>
      20  #include <string.h>
      21  #include <netinet/ether.h>
      22  #include <netinet/if_ether.h>
      23  
      24  
      25  int
      26  ether_line (const char *line, struct ether_addr *addr, char *hostname)
      27  {
      28    for (size_t cnt = 0; cnt < 6; ++cnt)
      29      {
      30        unsigned int number;
      31        char ch;
      32  
      33        ch = _tolower (*line++);
      34        if ((ch < '0' || ch > '9') && (ch < 'a' || ch > 'f'))
      35  	return -1;
      36        number = isdigit (ch) ? (ch - '0') : (ch - 'a' + 10);
      37  
      38        ch = _tolower (*line);
      39        if ((cnt < 5 && ch != ':') || (cnt == 5 && ch != '\0' && !isspace (ch)))
      40  	{
      41  	  ++line;
      42  	  if ((ch < '0' || ch > '9') && (ch < 'a' || ch > 'f'))
      43  	    return -1;
      44  	  number <<= 4;
      45  	  number += isdigit (ch) ? (ch - '0') : (ch - 'a' + 10);
      46  
      47  	  ch = *line;
      48  	  if (cnt < 5 && ch != ':')
      49  	    return -1;
      50  	}
      51  
      52        /* Store result.  */
      53        addr->ether_addr_octet[cnt] = (unsigned char) number;
      54  
      55        /* Skip ':'.  */
      56        if (ch != '\0')
      57  	++line;
      58      }
      59  
      60    /* Skip initial whitespace.  */
      61    while (isspace (*line))
      62      ++line;
      63  
      64    if (*line == '#' || *line == '\0')
      65      /* No hostname.  */
      66      return -1;
      67  
      68    /* The hostname is up to the next non-space character.  */
      69    /* XXX This can cause trouble because the hostname might be too long
      70       but we have no possibility to check it here.  */
      71    while (*line != '\0' && *line != '#' && !isspace (*line))
      72      *hostname++ = *line++;
      73    *hostname = '\0';
      74  
      75    return 0;
      76  }