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 1.3 2000-01-09 21:35:45 fenner Exp $ */
  40
  41 #ifndef lint
  42 static const char rcsid[] =
  43      "@(#) $Header: /tcpdump/master/tcpdump/missing/inet_ntop.c,v 1.3 2000-01-09 21:35:45 fenner Exp $";
  44 #endif
  45
  46 #include <stdio.h>
  47 #include <errno.h>
  48 #include <sys/types.h>
  49 #include <sys/socket.h>
  50 #include <netinet/in.h>
  51
  52 /*
  53  *
  54  */
  55
  56 #ifndef INET_ADDRSTRLEN
  57 #define INET_ADDRSTRLEN    16
  58 #endif
  59
  60 static const char *
  61 inet_ntop_v4 (const void *src, char *dst, size_t size)
  62 {
  63     const char digits[] = "0123456789";
  64     int i;
  65     struct in_addr *addr = (struct in_addr *)src;
  66     u_long a = ntohl(addr->s_addr);
  67     const char *orig_dst = dst;
  68
  69     if (size < INET_ADDRSTRLEN) {
  70         errno = ENOSPC;
  71         return NULL;
  72     }
  73     for (i = 0; i < 4; ++i) {
  74         int n = (a >> (24 - i * 8)) & 0xFF;
  75         int non_zerop = 0;
  76
  77         if (non_zerop || n / 100 > 0) {
  78             *dst++ = digits[n / 100];
  79             n %= 100;
  80             non_zerop = 1;
  81         }
  82         if (non_zerop || n / 10 > 0) {
  83             *dst++ = digits[n / 10];
  84             n %= 10;
  85             non_zerop = 1;
  86         }
  87         *dst++ = digits[n];
  88         if (i != 3)
  89             *dst++ = '.';
  90     }
  91     *dst++ = '\0';
  92     return orig_dst;
  93 }
  94
  95 const char *
  96 inet_ntop(int af, const void *src, char *dst, size_t size)
  97 {
  98     switch (af) {
  99     case AF_INET :
 100         return inet_ntop_v4 (src, dst, size);
 101     default :
 102         errno = EAFNOSUPPORT;
 103         return NULL;
 104     }
 105 }