public DhcpTaggedValueCollectionReader(DhcpBinaryReader reader)
{
_reader = reader;
if (reader.PeekByte() == PadByte)
{
reader.Seek(1);
}
}
public DhcpPacket Deserialize(byte[] bytes)
{
var reader = new DhcpBinaryReader(bytes);
var packetBuilder = DhcpPacketBuilder.Create();
uint magicCookie;
try
{
packetBuilder.WithOperation((DhcpOperation)reader.ReadValue(DhcpBinaryValue.ByteLength).AsByte());
var clientHardwareAddressType =
(ClientHardwareAddressType)reader.ReadValue(DhcpBinaryValue.ByteLength).AsByte();
var clientHardwareAddressLength = reader.ReadValue(DhcpBinaryValue.ByteLength).AsByte();
packetBuilder.WithHops(reader.ReadValue(DhcpBinaryValue.ByteLength).AsByte());
packetBuilder.WithTransactionId(reader.ReadValue(DhcpBinaryValue.UnsignedInt32Length)
.AsUnsignedInt32());
packetBuilder.WithSecs(reader.ReadValue(DhcpBinaryValue.UnsignedInt16Length).AsUnsignedInt16());
packetBuilder.WithBroadcastFlag(
reader.ReadValue(DhcpBinaryValue.UnsignedInt16Length).AsUnsignedInt16() == BroadcastFlag);
packetBuilder.WithClientIp(reader.ReadValue(DhcpBinaryValue.IpAddressLength).AsIpAddress());
packetBuilder.WithYourIp(reader.ReadValue(DhcpBinaryValue.IpAddressLength).AsIpAddress());
packetBuilder.WithServerIp(reader.ReadValue(DhcpBinaryValue.IpAddressLength).AsIpAddress());
packetBuilder.WithGatewayIp(reader.ReadValue(DhcpBinaryValue.IpAddressLength).AsIpAddress());
var clientHardwareAddressBytes = ReadClientHardwareAddress(reader, clientHardwareAddressLength);
packetBuilder.WithClientHardwareAddress(clientHardwareAddressType, clientHardwareAddressBytes);
packetBuilder.WithServerName(reader.ReadValue(64).AsString());
packetBuilder.WithBootFile(reader.ReadValue(128).AsString());
magicCookie = reader.ReadValue(DhcpBinaryValue.UnsignedInt32Length).AsUnsignedInt32();
var options = _optionsSerializer.DeserializeOptions(reader);
packetBuilder.WithOptions(options);
}
catch (InvalidOperationException e)
{
throw new DhcpSerializationException("The packet is not a valid DHCP packet.", e);
}
catch (IndexOutOfRangeException e)
{
throw new DhcpSerializationException("The packet is not a valid DHCP packet.", e);
}
if (magicCookie != MagicCookie)
{
throw new DhcpSerializationException("The packet does not contain the Magic cookie. It can be a valid BOOTP packet, but it is not a DHCP packet.");
}
return(packetBuilder.Build());
}
private byte[] ReadClientHardwareAddress(DhcpBinaryReader reader, byte addressLength)
{
const byte addressMaxLength = 16;
var clientHardwareAddress = reader.ReadValue(Math.Min(addressLength, addressMaxLength));
// Jump over padding bytes of the ClientHardwareAddress
var paddingLength = addressMaxLength - Math.Min(addressLength, addressMaxLength);
reader.Seek(paddingLength);
return(clientHardwareAddress.AsBytes());
}
