/// <summary> /// Simple constructor for the UDP header. /// </summary> public UdpHeader() : base() { srcPort = 0; destPort = 0; udpLength = 0; udpChecksum = 0; ipv6PacketHeader = null; ipv4PacketHeader = null; }
/// <summary> /// Constructor for the ICMPv6 header which also takes a reference to the /// encompassing IPv6 header. This is necessary since the IPv6 protocol /// defines a pseudo header checksum which requires the checksum to be /// calculated over fields in the ICMPv6 header and payload as well as /// fields from the IPv6 packet. /// </summary> /// <param name="packetHeader">Reference to the Ipv6Header object encompassing the ICMPv6 packet</param> public Icmpv6Header(Ipv6Header packetHeader) : base() { icmpType = 0; icmpCode = 0; icmpChecksum = 0; ipv6Header = packetHeader; }
/// <summary> /// This routine creates an instance of the Ipv6Header 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="ipv6Packet">Byte array containing the binary IPv6 header</param> /// <param name="bytesCopied">Number of bytes used in header</param> /// <returns>Returns the Ipv6Header object created from the byte array</returns> public static Ipv6Header Create( byte[] ipv6Packet, ref int bytesCopied ) { Ipv6Header ipv6Header = new Ipv6Header(); byte[] addressBytes = new byte[16]; uint tempVal = 0, tempVal2 = 0; // Ensure byte array is large enough to contain an IPv6 header if( ipv6Packet.Length < Ipv6Header.Ipv6HeaderLength ) return null; tempVal = ipv6Packet[0]; tempVal = (tempVal >> 4) & 0xF; ipv6Header.ipVersion = (byte)tempVal; tempVal = ipv6Packet[0]; tempVal = (tempVal & 0xF) >> 4; ipv6Header.ipTrafficClass = (byte)(tempVal | (uint)((ipv6Packet[1] >> 4) & 0xF)); tempVal2 = ipv6Packet[1]; tempVal2 = (tempVal2 & 0xF) << 16; tempVal = ipv6Packet[2]; tempVal = tempVal << 8; ipv6Header.ipFlow = tempVal2 | tempVal | ipv6Packet[3]; ipv6Header.ipNextHeader = ipv6Packet[4]; ipv6Header.ipHopLimit = ipv6Packet[5]; Array.Copy( ipv6Packet, 6, addressBytes, 0, 16 ); ipv6Header.SourceAddress = new IPAddress( addressBytes ); Array.Copy( ipv6Packet, 24, addressBytes, 0, 16 ); ipv6Header.DestinationAddress = new IPAddress( addressBytes ); bytesCopied = Ipv6Header.Ipv6HeaderLength; return ipv6Header; }
/// <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 ); } }