private AsyncCallback receiveCallback; // Async callback function called when a receive completes
#endregion Fields
#region Constructors
// this ping class can be disposed
/// <summary>
/// Base constructor that initializes the member variables to default values. It also
/// creates the events used and initializes the async callback function.
/// </summary>
public RawSocketPing()
{
pingSocket = null;
pingFamily = AddressFamily.InterNetwork;
pingTtl = 8;
pingPayloadLength = 8;
pingSequence = 0;
pingReceiveTimeout = 4000;
pingOutstandingReceives = 0;
destEndPoint = new IPEndPoint( IPAddress.Loopback, 0 );
protocolHeaderList = new ArrayList();
pingReceiveEvent = new ManualResetEvent( false );
pingDoneEvent = new ManualResetEvent( false );
receiveCallback = new AsyncCallback( PingReceiveCallback );
icmpHeader = null;
icmpv6Header = null;
icmpv6EchoRequestHeader = null;
}
/// <summary>
/// This routine creates an instance of the Icmpv6Header class from a byte
/// array that is a received IGMP packet. This is useful when a packet
/// is received from the network and the header object needs to be
/// constructed from those values.
/// </summary>
/// <param name="icmpv6Packet">Byte array containing the binary ICMPv6 header</param>
/// <param name="bytesCopied">Number of bytes used in header</param>
/// <returns>Returns the Icmpv6Header object created from the byte array</returns>
public static Icmpv6Header Create(byte[ ] icmpv6Packet, ref int bytesCopied)
{
Icmpv6Header icmpv6Header = new Icmpv6Header();
int offset = 0;
// Verify buffer is large enough to contain an ICMPv6 header
if (icmpv6Packet.Length < Icmpv6Header.Icmpv6HeaderLength)
return null;
icmpv6Header.icmpType = icmpv6Packet[offset++];
icmpv6Header.icmpCode = icmpv6Packet[offset++];
icmpv6Header.icmpChecksum = BitConverter.ToUInt16(icmpv6Packet, offset);
bytesCopied = Icmpv6Header.Icmpv6HeaderLength;
return icmpv6Header;
}
/// <summary>
/// This routine builds the appropriate ICMP echo packet depending on the
/// protocol family requested.
/// </summary>
public void BuildPingPacket()
{
// Initialize the socket if it hasn't already been done
//Console.WriteLine( "Building the ping packet..." );
//Console.WriteLine( "Initializing the socket if not done yet..." );
if( pingSocket == null )
{
InitializeSocket();
}
// Clear any existing headers in the list
//Console.WriteLine( "Clearing any existing headers in the list using Clear()..." );
protocolHeaderList.Clear();
if( destEndPoint.AddressFamily == AddressFamily.InterNetwork )
{
// Create the ICMP header and initialize the members
//Console.WriteLine( "Creating the ICMP header and initialize the members..." );
icmpHeader = new IcmpHeader();
icmpHeader.Id = pingId;
icmpHeader.Sequence = pingSequence;
icmpHeader.Type = IcmpHeader.EchoRequestType;
icmpHeader.Code = IcmpHeader.EchoRequestCode;
// Build the data payload of the ICMP echo request
//Console.WriteLine( "Building the data payload of the ICMP echo request..." );
pingPayload = new byte[pingPayloadLength];
for( int i = 0 ; i < pingPayload.Length ; i++ )
{
pingPayload[i] = (byte)'e';
}
// Add ICMP header to the list of headers
//Console.WriteLine( "Adding ICMP header to the list of headers using Add()..." );
protocolHeaderList.Add( icmpHeader );
}
else if( destEndPoint.AddressFamily == AddressFamily.InterNetworkV6 )
{
Ipv6Header ipv6Header; // Required for pseudo header checksum
IPEndPoint localInterface;
byte[] localAddressBytes = new byte[28];
Console.WriteLine( "This part is for IPv6..." );
// An IPv6 header is required since the IPv6 protocol specifies that the
// pseudo header checksum needs to be calculated on ICMPv6 packets which
// requires the source and destination address that will appear in the
// IPv6 packet.
ipv6Header = new Ipv6Header();
// We definitely know the destination IPv6 address but the stack will
// choose the "appropriate" local v6 interface depending on the
// routing table which may be different than the address we bound
// the socket to. Because of this we will call the Winsock ioctl
// SIO_ROUTING_INTERFACE_QUERY which will return the local interface
// for a given destination address by querying the routing table.
Console.WriteLine( "Implementing the IOControl()..." );
pingSocket.IOControl( WinsockIoctl.SIO_ROUTING_INTERFACE_QUERY, SockaddrConvert.GetSockaddrBytes( destEndPoint ), localAddressBytes );
localInterface = SockaddrConvert.GetEndPoint( localAddressBytes );
// Fill out the fields of the IPv6 header used in the pseudo-header checksum calculation
Console.WriteLine( "Filling out the IPv6 header fields..." );
ipv6Header.SourceAddress = localInterface.Address;
ipv6Header.DestinationAddress = destEndPoint.Address;
ipv6Header.NextHeader = 58; // IPPROTO_ICMP6
// Initialize the ICMPv6 header
Console.WriteLine( "Initializing the ICMPv6 header..." );
icmpv6Header = new Icmpv6Header( ipv6Header );
icmpv6Header.Type = Icmpv6Header.Icmpv6EchoRequestType;
icmpv6Header.Code = Icmpv6Header.Icmpv6EchoRequestCode;
// Initialize the payload
Console.WriteLine( "Initializing the payload..." );
pingPayload = new byte[pingPayloadLength];
for( int i = 0 ; i < pingPayload.Length ; i++ )
{
pingPayload[i] = (byte)'e';
}
// Create the ICMPv6 echo request header
Console.WriteLine( "Creating the ICMPv6 echo request header..." );
icmpv6EchoRequestHeader = new Icmpv6EchoRequest();
icmpv6EchoRequestHeader.Id = pingId;
// Add the headers to the protocol header list
Console.WriteLine( "Adding the headers to the protocol header list..." );
protocolHeaderList.Add( icmpv6Header );
protocolHeaderList.Add( icmpv6EchoRequestHeader );
}
}