/* * Copyright (c) 1999 Kungliga Tekniska H鰃skolan * (Royal Institute of Technology, Stockholm, Sweden). * All rights reserved. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * * 1. Redistributions of source code must retain the above copyright *    notice, this list of conditions and the following disclaimer. * * 2. Redistributions in binary form must reproduce the above copyright *    notice, this list of conditions and the following disclaimer in the *    documentation and/or other materials provided with the distribution. * * 3. All advertising materials mentioning features or use of this software *    must display the following acknowledgement: *      This product includes software developed by the Kungliga Tekniska *      H鰃skolan and its contributors. * * 4. Neither the name of the Institute nor the names of its contributors *    may be used to endorse or promote products derived from this software *    without specific prior written permission. * * THIS SOFTWARE IS PROVIDED BY THE INSTITUTE AND CONTRIBUTORS ``AS IS'' AND * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE * ARE DISCLAIMED.  IN NO EVENT SHALL THE INSTITUTE OR CONTRIBUTORS BE LIABLE * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF * SUCH DAMAGE. *//* $Id: inet_ntop.c,v 1.8 2005-02-09 02:25:46 guy Exp $ */#ifndef lintstatic const char rcsid[] _U_ =     "@(#) $Header: /tcpdump/master/tcpdump/missing/inet_ntop.c,v 1.8 2005-02-09 02:25:46 guy Exp $";#endif#include <tcpdump-stdinc.h>#include <stdio.h>#include <errno.h>/* * */#ifndef IN6ADDRSZ#define IN6ADDRSZ   16   /* IPv6 T_AAAA */#endif#ifndef INT16SZ#define INT16SZ     2    /* word size */#endifstatic const char *inet_ntop_v4 (const void *src, char *dst, size_t size){    const char digits[] = "0123456789";    int i;    struct in_addr *addr = (struct in_addr *)src;    u_long a = ntohl(addr->s_addr);    const char *orig_dst = dst;    if (size < INET_ADDRSTRLEN) {	errno = ENOSPC;	return NULL;    }    for (i = 0; i < 4; ++i) {	int n = (a >> (24 - i * 8)) & 0xFF;	int non_zerop = 0;	if (non_zerop || n / 100 > 0) {	    *dst++ = digits[n / 100];	    n %= 100;	    non_zerop = 1;	}	if (non_zerop || n / 10 > 0) {	    *dst++ = digits[n / 10];	    n %= 10;	    non_zerop = 1;	}	*dst++ = digits[n];	if (i != 3)	    *dst++ = '.';    }    *dst++ = '\0';    return orig_dst;}#ifdef INET6/* * Convert IPv6 binary address into presentation (printable) format. */static const char *inet_ntop_v6 (const u_char *src, char *dst, size_t size){  /*   * Note that int32_t and int16_t need only be "at least" large enough   * to contain a value of the specified size.  On some systems, like   * Crays, there is no such thing as an integer variable with 16 bits.   * Keep this in mind if you think this function should have been coded   * to use pointer overlays.  All the world's not a VAX.   */  char  tmp [INET6_ADDRSTRLEN+1];  char *tp;  struct {    long base;    long len;  } best, cur;  u_long words [IN6ADDRSZ / INT16SZ];  int    i;  /* Preprocess:   *  Copy the input (bytewise) array into a wordwise array.   *  Find the longest run of 0x00's in src[] for :: shorthanding.   */  memset (words, 0, sizeof(words));  for (i = 0; i < IN6ADDRSZ; i++)      words[i/2] |= (src[i] << ((1 - (i % 2)) << 3));  best.base = -1;  cur.base  = -1;  for (i = 0; i < (IN6ADDRSZ / INT16SZ); i++)  {    if (words[i] == 0)    {      if (cur.base == -1)           cur.base = i, cur.len = 1;      else cur.len++;    }    else if (cur.base != -1)    {      if (best.base == -1 || cur.len > best.len)         best = cur;      cur.base = -1;    }  }  if ((cur.base != -1) && (best.base == -1 || cur.len > best.len))     best = cur;  if (best.base != -1 && best.len < 2)     best.base = -1;  /* Format the result.   */  tp = tmp;  for (i = 0; i < (IN6ADDRSZ / INT16SZ); i++)  {    /* Are we inside the best run of 0x00's?     */    if (best.base != -1 && i >= best.base && i < (best.base + best.len))    {      if (i == best.base)         *tp++ = ':';      continue;    }    /* Are we following an initial run of 0x00s or any real hex?     */    if (i != 0)       *tp++ = ':';    /* Is this address an encapsulated IPv4?     */    if (i == 6 && best.base == 0 &&        (best.len == 6 || (best.len == 5 && words[5] == 0xffff)))    {      if (!inet_ntop_v4(src+12, tp, sizeof(tmp) - (tp - tmp)))      {        errno = ENOSPC;        return (NULL);      }      tp += strlen(tp);      break;    }    tp += sprintf (tp, "%lX", words[i]);  }  /* Was it a trailing run of 0x00's?   */  if (best.base != -1 && (best.base + best.len) == (IN6ADDRSZ / INT16SZ))     *tp++ = ':';  *tp++ = '\0';  /* Check for overflow, copy, and we're done.   */  if ((size_t)(tp - tmp) > size)  {    errno = ENOSPC;    return (NULL);  }  return strcpy (dst, tmp);  return (NULL);}#endif   /* INET6 */const char *inet_ntop(int af, const void *src, char *dst, size_t size){    switch (af) {    case AF_INET :	return inet_ntop_v4 (src, dst, size);#ifdef INET6    case AF_INET6:         return inet_ntop_v6 ((const u_char*)src, dst, size);#endif    default :	errno = EAFNOSUPPORT;	return NULL;    }}