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 1.5.2.2 2003-11-16 08:52:01 guy Exp $ */
  40
  41 #ifndef lint
  42 static const char rcsid[] _U_ =
  43      "@(#) $Header: /tcpdump/master/tcpdump/missing/inet_ntop.c,v 1.5.2.2 2003-11-16 08:52:01 guy Exp $";
  44 #endif
  45
  46 #include <tcpdump-stdinc.h>
  47
  48 #include <stdio.h>
  49 #include <errno.h>
  50
  51 /*
  52  *
  53  */
  54
  55 #ifndef INET_ADDRSTRLEN
  56 #define INET_ADDRSTRLEN    16
  57 #endif
  58
  59 static const char *
  60 inet_ntop_v4 (const void *src, char *dst, size_t size)
  61 {
  62     const char digits[] = "0123456789";
  63     int i;
  64     struct in_addr *addr = (struct in_addr *)src;
  65     u_long a = ntohl(addr->s_addr);
  66     const char *orig_dst = dst;
  67
  68     if (size < INET_ADDRSTRLEN) {
  69         errno = ENOSPC;
  70         return NULL;
  71     }
  72     for (i = 0; i < 4; ++i) {
  73         int n = (a >> (24 - i * 8)) & 0xFF;
  74         int non_zerop = 0;
  75
  76         if (non_zerop || n / 100 > 0) {
  77             *dst++ = digits[n / 100];
  78             n %= 100;
  79             non_zerop = 1;
  80         }
  81         if (non_zerop || n / 10 > 0) {
  82             *dst++ = digits[n / 10];
  83             n %= 10;
  84             non_zerop = 1;
  85         }
  86         *dst++ = digits[n];
  87         if (i != 3)
  88             *dst++ = '.';
  89     }
  90     *dst++ = '\0';
  91     return orig_dst;
  92 }
  93
  94 const char *
  95 inet_ntop(int af, const void *src, char *dst, size_t size)
  96 {
  97     switch (af) {
  98     case AF_INET :
  99         return inet_ntop_v4 (src, dst, size);
 100     default :
 101         errno = EAFNOSUPPORT;
 102         return NULL;
 103     }
 104 }