The Tcpdump Group git mirrors - tcpdump/blob - missing/inet_ntop.c

   1 /*
   2  * Copyright (c) 1999 Kungliga Tekniska Högskolan
   3  * (Royal Institute of Technology, Stockholm, Sweden).
   4  * All rights reserved.
   5  *
   6  * Redistribution and use in source and binary forms, with or without
   7  * modification, are permitted provided that the following conditions
   8  * are met:
   9  *
  10  * 1. Redistributions of source code must retain the above copyright
  11  *    notice, this list of conditions and the following disclaimer.
  12  *
  13  * 2. Redistributions in binary form must reproduce the above copyright
  14  *    notice, this list of conditions and the following disclaimer in the
  15  *    documentation and/or other materials provided with the distribution.
  16  *
  17  * 3. All advertising materials mentioning features or use of this software
  18  *    must display the following acknowledgement:
  19  *      This product includes software developed by the Kungliga Tekniska
  20  *      Högskolan and its contributors.
  21  *
  22  * 4. Neither the name of the Institute nor the names of its contributors
  23  *    may be used to endorse or promote products derived from this software
  24  *    without specific prior written permission.
  25  *
  26  * THIS SOFTWARE IS PROVIDED BY THE INSTITUTE AND CONTRIBUTORS ``AS IS'' AND
  27  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  28  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  29  * ARE DISCLAIMED.  IN NO EVENT SHALL THE INSTITUTE OR CONTRIBUTORS BE LIABLE
  30  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  31  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  32  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  33  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  34  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  35  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  36  * SUCH DAMAGE.
  37  */
  38
  39 /* $Id: inet_ntop.c,v 1.5.2.1 2003-11-15 22:29:21 guy Exp $ */
  40
  41
  42 #include <tcpdump-stdinc.h>
  43
  44
  45 #include "interface.h"
  46
  47 #ifndef lint
  48 static const char rcsid[] _U_ =
  49      "@(#) $Header: /tcpdump/master/tcpdump/missing/inet_ntop.c,v 1.5.2.1 2003-11-15 22:29:21 guy Exp $";
  50 #endif
  51
  52 #include <stdio.h>
  53 #include <errno.h>
  54
  55 /*
  56  *
  57  */
  58
  59 #ifndef INET_ADDRSTRLEN
  60 #define INET_ADDRSTRLEN    16
  61 #endif
  62
  63 static const char *
  64 inet_ntop_v4 (const void *src, char *dst, size_t size)
  65 {
  66     const char digits[] = "0123456789";
  67     int i;
  68     struct in_addr *addr = (struct in_addr *)src;
  69     u_long a = ntohl(addr->s_addr);
  70     const char *orig_dst = dst;
  71
  72     if (size < INET_ADDRSTRLEN) {
  73         errno = ENOSPC;
  74         return NULL;
  75     }
  76     for (i = 0; i < 4; ++i) {
  77         int n = (a >> (24 - i * 8)) & 0xFF;
  78         int non_zerop = 0;
  79
  80         if (non_zerop || n / 100 > 0) {
  81             *dst++ = digits[n / 100];
  82             n %= 100;
  83             non_zerop = 1;
  84         }
  85         if (non_zerop || n / 10 > 0) {
  86             *dst++ = digits[n / 10];
  87             n %= 10;
  88             non_zerop = 1;
  89         }
  90         *dst++ = digits[n];
  91         if (i != 3)
  92             *dst++ = '.';
  93     }
  94     *dst++ = '\0';
  95     return orig_dst;
  96 }
  97
  98 const char *
  99 inet_ntop(int af, const void *src, char *dst, size_t size)
 100 {
 101     switch (af) {
 102     case AF_INET :
 103         return inet_ntop_v4 (src, dst, size);
 104     default :
 105         errno = EAFNOSUPPORT;
 106         return NULL;
 107     }
 108 }