149 lines
3.7 KiB
C#
149 lines
3.7 KiB
C#
//
|
|
// System.Net.IPv6AddressFormatter.cs
|
|
//
|
|
// Author:
|
|
// Lawrence Pit (loz@cable.a2000.nl)
|
|
//
|
|
// Permission is hereby granted, free of charge, to any person obtaining
|
|
// a copy of this software and associated documentation files (the
|
|
// "Software"), to deal in the Software without restriction, including
|
|
// without limitation the rights to use, copy, modify, merge, publish,
|
|
// distribute, sublicense, and/or sell copies of the Software, and to
|
|
// permit persons to whom the Software is furnished to do so, subject to
|
|
// the following conditions:
|
|
//
|
|
// The above copyright notice and this permission notice shall be
|
|
// included in all copies or substantial portions of the Software.
|
|
//
|
|
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
|
|
// EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
|
|
// MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
|
|
// NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
|
|
// LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
|
|
// OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
|
|
// WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
|
|
//
|
|
|
|
using System.Globalization;
|
|
using System.Text;
|
|
|
|
namespace System.Net {
|
|
|
|
struct IPv6AddressFormatter
|
|
{
|
|
ushort [] address;
|
|
long scopeId;
|
|
|
|
public IPv6AddressFormatter (ushort[] addr, long scopeId)
|
|
{
|
|
this.address = addr;
|
|
this.scopeId = scopeId;
|
|
}
|
|
|
|
static ushort SwapUShort (ushort number)
|
|
{
|
|
return (ushort) ( ((number >> 8) & 0xFF) + ((number << 8) & 0xFF00) );
|
|
}
|
|
|
|
// Convert the address into a format expected by the IPAddress (long) ctor
|
|
// This needs to be unsigned to satisfy the '> 1' test in IsIPv4Compatible()
|
|
uint AsIPv4Int ()
|
|
{
|
|
return (uint)(SwapUShort (address [7]) << 16) + SwapUShort (address [6]);
|
|
}
|
|
|
|
bool IsIPv4Compatible ()
|
|
{
|
|
for (int i = 0; i < 6; i++)
|
|
if (address [i] != 0)
|
|
return false;
|
|
/* MS .net only seems to format the last 4
|
|
* bytes as an IPv4 address if address[6] is
|
|
* non-zero
|
|
*/
|
|
if (address[6] == 0)
|
|
return false;
|
|
return (AsIPv4Int () > 1);
|
|
}
|
|
|
|
bool IsIPv4Mapped ()
|
|
{
|
|
for (int i = 0; i < 5; i++)
|
|
if (address [i] != 0)
|
|
return false;
|
|
/* MS .net only seems to format the last 4
|
|
* bytes as an IPv4 address if address[6] is
|
|
* non-zero
|
|
*/
|
|
if (address[6] == 0)
|
|
return false;
|
|
|
|
return address [5] == 0xffff;
|
|
}
|
|
|
|
public override string ToString ()
|
|
{
|
|
StringBuilder s = new StringBuilder ();
|
|
|
|
|
|
if(IsIPv4Compatible() || IsIPv4Mapped())
|
|
{
|
|
s.Append("::");
|
|
|
|
if(IsIPv4Mapped())
|
|
s.Append("ffff:");
|
|
|
|
s.Append(new IPAddress( AsIPv4Int ()).ToString ());
|
|
|
|
return s.ToString ();
|
|
}
|
|
|
|
int bestChStart = -1; // Best chain start
|
|
int bestChLen = 0; // Best chain length
|
|
int currChLen = 0; // Current chain length
|
|
|
|
// Looks for the longest zero chain
|
|
for (int i=0; i<8; i++)
|
|
{
|
|
if (address[i] != 0)
|
|
{
|
|
if ((currChLen > bestChLen)
|
|
&& (currChLen > 1))
|
|
{
|
|
bestChLen = currChLen;
|
|
bestChStart = i - currChLen;
|
|
}
|
|
currChLen = 0;
|
|
}
|
|
else
|
|
currChLen++;
|
|
}
|
|
if ((currChLen > bestChLen)
|
|
&& (currChLen > 1))
|
|
{
|
|
bestChLen = currChLen;
|
|
bestChStart = 8 - currChLen;
|
|
}
|
|
|
|
// makes the string
|
|
if (bestChStart == 0)
|
|
s.Append(":");
|
|
for (int i=0; i<8; i++)
|
|
{
|
|
if (i == bestChStart)
|
|
{
|
|
s.Append (":");
|
|
i += (bestChLen - 1);
|
|
continue;
|
|
}
|
|
s.AppendFormat("{0:x}", address [i]);
|
|
if (i < 7) s.Append (':');
|
|
}
|
|
|
|
if (scopeId != 0)
|
|
s.Append ('%').Append (scopeId);
|
|
return s.ToString ();
|
|
}
|
|
}
|
|
}
|