gen.subproj/ether_addr.c

   1 /*
   2  * Copyright (c) 1999 Apple Computer, 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 ether_line(s, e, hostname)
  57         char *s;                /* the string to be parsed */
  58         struct ether_addr *e;   /* ethernet address struct to be filled in */
  59         char *hostname;         /* hosts name to be set */
  60 {
  61         register int i;
  62         unsigned int t[6];
  63
  64         i = sscanf(s, " %x:%x:%x:%x:%x:%x %s",
  65             &t[0], &t[1], &t[2], &t[3], &t[4], &t[5], hostname);
  66         if (i != 7) {
  67                 return (7 - i);
  68         }
  69         for (i = 0; i < 6; i++)
  70                 e->ether_addr_octet[i] = t[i];
  71         return (0);
  72 }
  73
  74 /*
  75  * Converts a 48 bit ethernet number to its string representation.
  76  */
  77 #define EI(i)   (unsigned int)(e->ether_addr_octet[(i)])
  78 char *
  79 ether_ntoa(e)
  80         struct ether_addr *e;
  81 {
  82         static char *s;
  83
  84         if (s == 0) {
  85                 s = (char *)malloc(18);
  86                 if (s == 0)
  87                         return (0);
  88         }
  89         s[0] = 0;
  90         sprintf(s, "%x:%x:%x:%x:%x:%x",
  91             EI(0), EI(1), EI(2), EI(3), EI(4), EI(5));
  92         return (s);
  93 }
  94
  95 /*
  96  * Converts a ethernet address representation back into its 48 bits.
  97  */
  98 struct ether_addr *
  99 ether_aton(s)
 100         char *s;
 101 {
 102         static struct ether_addr *ep;
 103         register int i;
 104         unsigned int t[6];
 105
 106         if (ep == 0) {
 107                 ep = (struct ether_addr *)calloc(1, sizeof (struct ether_addr));
 108                 if (ep == 0)
 109                         return (0);
 110         }
 111         i = sscanf(s, " %x:%x:%x:%x:%x:%x",
 112             &t[0], &t[1], &t[2], &t[3], &t[4], &t[5]);
 113         if (i != 6)
 114             return ((struct ether_addr *)NULL);
 115         for (i = 0; i < 6; i++)
 116                 ep->ether_addr_octet[i] = t[i];
 117         return (ep);
 118 }
 119
 120 /*
 121  * Given a host's name, this routine returns its 48 bit ethernet address.
 122  * Returns zero if successful, non-zero otherwise.
 123  */
 124 /* XXX need to override in netinfo */
 125 int ether_hostton(host, e)
 126         char *host;             /* function input */
 127         struct ether_addr *e;   /* function output */
 128 {
 129         char currenthost[256];
 130         char buf[512];
 131         char *val = buf;
 132         register int reason;
 133         FILE *f;
 134
 135         if ((f = fopen(ethers, "r")) == NULL)
 136         {
 137                 return (-1);
 138         }
 139
 140         reason = -1;
 141         while (fscanf(f, "%[^\n] ", val) == 1)
 142         {
 143                 if ((ether_line(val, e, currenthost) == 0) &&
 144                         (strcmp(currenthost, host) == 0))
 145                 {
 146                         reason = 0;
 147                         break;
 148                 }
 149         }
 150
 151         fclose(f);
 152         return (reason);
 153 }
 154
 155 /*
 156  * Given a 48 bit ethernet address, this routine return its host name.
 157  * Returns zero if successful, non-zero otherwise.
 158  */
 159 /* XXX need to override in netinfo */
 160 int ether_ntohost(host, e)
 161         char *host;             /* function output */
 162         struct ether_addr *e;   /* function input */
 163 {
 164         struct ether_addr currente;
 165         char buf[512];
 166         char *val = buf;
 167         register int reason;
 168         FILE *f;
 169
 170         if ((f = fopen(ethers, "r")) == NULL)
 171         {
 172                 return (-1);
 173         }
 174
 175         reason = -1;
 176         while (fscanf(f, "%[^\n] ", val) == 1)
 177         {
 178                 if ((ether_line(val, &currente, host) == 0) &&
 179                         (bcmp(e, &currente, sizeof(currente)) == 0))
 180                 {
 181                         reason = 0;
 182                         break;
 183                 }
 184         }
 185
 186         fclose(f);
 187         return (reason);
 188 }