X-Git-Url: https://git.tcpdump.org/tcpdump/blobdiff_plain/70fbff8d347609250fae0846cff0f412bc9005bd..refs/pull/435/head:/missing/inet_ntop.c

diff --git a/missing/inet_ntop.c b/missing/inet_ntop.c
index a6801b27..8c6f7eb8 100644
--- a/missing/inet_ntop.c
+++ b/missing/inet_ntop.c
@@ -2,27 +2,27 @@
  * Copyright (c) 1999 Kungliga Tekniska Högskolan
  * (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
  *      Högskolan 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
@@ -36,20 +36,24 @@
  * SUCH DAMAGE.
  */
 
-/* $Id: inet_ntop.c,v 1.2 1999-10-30 23:45:52 itojun Exp $ */
+#ifdef HAVE_CONFIG_H
+#include "config.h"
+#endif
+
+#include <tcpdump-stdinc.h>
 
 #include <stdio.h>
-#include <errno.h>
-#include <sys/types.h>
-#include <sys/socket.h>
-#include <netinet/in.h>
 
 /*
  *
  */
 
-#ifndef INET_ADDRSTRLEN
-#define INET_ADDRSTRLEN    16
+#ifndef IN6ADDRSZ
+#define IN6ADDRSZ   16   /* IPv6 T_AAAA */
+#endif
+
+#ifndef INT16SZ
+#define INT16SZ     2    /* word size */
 #endif
 
 static const char *
@@ -87,12 +91,124 @@ inet_ntop_v4 (const void *src, char *dst, size_t size)
     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.len = 0;
+  best.base = -1;
+  cur.len = 0;
+  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);
+}
+#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;