gen.subproj/ether_addr.c

   1 /*
   2  * Copyright (c) 1999-2008 Apple Inc. All rights reserved.
   3  *
   4  * @APPLE_LICENSE_HEADER_START@
   5  *
   6  * Portions Copyright (c) 1999 Apple Computer, Inc.  All Rights
   7  * Reserved.  This file contains Original Code and/or Modifications of
   8  * Original Code as defined in and that are subject to the Apple Public
   9  * Source License Version 1.1 (the "License").  You may not use this file
  10  * except in compliance with the License.  Please obtain a copy of the
  11  * License at http://www.apple.com/publicsource and read it before using
  12  * this file.
  13  *
  14  * The Original Code and all software distributed under the License are
  15  * distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY KIND, EITHER
  16  * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
  17  * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
  18  * FITNESS FOR A PARTICULAR PURPOSE OR NON- INFRINGEMENT.  Please see the
  19  * License for the specific language governing rights and limitations
  20  * under the License.
  21  *
  22  * @APPLE_LICENSE_HEADER_END@
  23  */
  24 #if !defined(lint) && defined(SCCSIDS)
  25 static  char sccsid[] = "@(#)ether_addr.c       1.2 88/05/10 4.0NFSSRC; from 1.9 88/02/08 Copyr 1985 Sun Micro";
  26 #endif
  27
  28 /*
  29  * Copyright (c) 1985 by Sun Microsystems, Inc.
  30  *
  31  * All routines necessary to deal with the file /etc/ethers.  The file
  32  * contains mappings from 48 bit ethernet addresses to their corresponding
  33  * hosts name.  The addresses have an ascii representation of the form
  34  * "x:x:x:x:x:x" where x is a hex number between 0x00 and 0xff;  the
  35  * bytes are always in network order.
  36  */
  37
  38 #include <stdlib.h>
  39 #include <string.h>
  40 #include <stdio.h>
  41 #include <sys/types.h>
  42 #include <sys/socket.h>
  43 #include <net/if.h>
  44 #include <netinet/in.h>
  45 #include <netinet/if_ether.h>
  46
  47 static const char ethers[] = "/etc/ethers";
  48
  49 /*
  50  * Parses a line from /etc/ethers into its components.  The line has the form
  51  * 8:0:20:1:17:c8       krypton
  52  * where the first part is a 48 bit ethernet addrerss and the second is
  53  * the corresponding hosts name.
  54  * Returns zero if successful, non-zero otherwise.
  55  */
  56 int
  57 ether_line(const char *s, struct ether_addr *e, char *hostname)
  58 {
  59         int i;
  60         unsigned int t[6];
  61
  62         i = sscanf(s, " %x:%x:%x:%x:%x:%x %s", &t[0], &t[1], &t[2], &t[3], &t[4], &t[5], hostname);
  63         if (i != 7) return (7 - i);
  64
  65         for (i = 0; i < 6; i++) e->ether_addr_octet[i] = t[i];
  66         return 0;
  67 }
  68
  69 /*
  70  * Converts a 48 bit ethernet number to its string representation.
  71  */
  72 #define EI(i) (unsigned int)(e->ether_addr_octet[(i)])
  73 char *
  74 ether_ntoa(const struct ether_addr *e)
  75 {
  76         static char *s;
  77
  78         if (s == 0)
  79         {
  80                 s = (char *)malloc(18);
  81                 if (s == 0) return NULL;
  82         }
  83
  84         s[0] = 0;
  85         sprintf(s, "%x:%x:%x:%x:%x:%x", EI(0), EI(1), EI(2), EI(3), EI(4), EI(5));
  86         return s;
  87 }
  88
  89 /*
  90  * Converts a ethernet address representation back into its 48 bits.
  91  */
  92 struct ether_addr *
  93 ether_aton(const char *s)
  94 {
  95         static struct ether_addr *ep;
  96         int i;
  97         unsigned int t[6];
  98
  99         if (ep == 0)
 100         {
 101                 ep = (struct ether_addr *)calloc(1, sizeof (struct ether_addr));
 102                 if (ep == 0) return NULL;
 103         }
 104
 105         i = sscanf(s, " %x:%x:%x:%x:%x:%x", &t[0], &t[1], &t[2], &t[3], &t[4], &t[5]);
 106         if (i != 6) return NULL;
 107
 108         for (i = 0; i < 6; i++) ep->ether_addr_octet[i] = t[i];
 109         return ep;
 110 }