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 1.1 1999-10-30 07:53:39 itojun Exp $ */
  40
  41 #include <errno.h>
  42 #include <sys/types.h>
  43 #include <sys/socket.h>
  44 #include <netinet/in.h>
  45
  46 /*
  47  *
  48  */
  49
  50 #ifndef INET_ADDRSTRLEN
  51 #define INET_ADDRSTRLEN    16
  52 #endif
  53
  54 static const char *
  55 inet_ntop_v4 (const void *src, char *dst, size_t size)
  56 {
  57     const char digits[] = "0123456789";
  58     int i;
  59     struct in_addr *addr = (struct in_addr *)src;
  60     u_long a = ntohl(addr->s_addr);
  61     const char *orig_dst = dst;
  62
  63     if (size < INET_ADDRSTRLEN) {
  64         errno = ENOSPC;
  65         return NULL;
  66     }
  67     for (i = 0; i < 4; ++i) {
  68         int n = (a >> (24 - i * 8)) & 0xFF;
  69         int non_zerop = 0;
  70
  71         if (non_zerop || n / 100 > 0) {
  72             *dst++ = digits[n / 100];
  73             n %= 100;
  74             non_zerop = 1;
  75         }
  76         if (non_zerop || n / 10 > 0) {
  77             *dst++ = digits[n / 10];
  78             n %= 10;
  79             non_zerop = 1;
  80         }
  81         *dst++ = digits[n];
  82         if (i != 3)
  83             *dst++ = '.';
  84     }
  85     *dst++ = '\0';
  86     return orig_dst;
  87 }
  88
  89 const char *
  90 inet_ntop(int af, const void *src, char *dst, size_t size)
  91 {
  92     switch (af) {
  93     case AF_INET :
  94         return inet_ntop_v4 (src, dst, size);
  95     default :
  96         errno = EAFNOSUPPORT;
  97         return NULL;
  98     }
  99 }