public static void LogUnhandledRead(this IPeripheral peripheral, long offset)
{
peripheral.Log(LogLevel.Warning, "Unhandled read from offset 0x{0:X}.", offset);
}
public static void LogUnhandledWrite(this IPeripheral peripheral, long offset, long value)
{
peripheral.Log(LogLevel.Warning, "Unhandled write to offset 0x{0:X}, value 0x{1:X}.", offset, value);
}
//TODO: Support for ipv6
public static void FillPacketWithChecksums(IPeripheral source, byte[] packet, params TransportLayerProtocol[] interpretedProtocols)
{
if (packet.Length < MACLength)
{
source.Log(LogLevel.Error, String.Format("Expected packet of at least {0} bytes, got {1}.", MACLength, packet.Length));
return;
}
var packet_type = (PacketType)((packet[12] << 8) | packet[13]);
if (packet_type == PacketType.ARP)
{
// ARP
return;
}
else if (packet_type != PacketType.IP)
{
source.Log(LogLevel.Error, String.Format("Unknown packet type: 0x{0:X}. Supported are: 0x800 (IP) and 0x806 (ARP).", (ushort)packet_type));
return;
}
if (packet.Length < (MACLength + 12))
{
source.Log(LogLevel.Error, "IP Packet is too short!");
return;
}
// IPvX
if ((packet[MACLength] >> 4) != 0x04)
{
source.Log(LogLevel.Error, String.Format("Only IPv4 packets are supported. Got IPv{0}", (packet[MACLength] >> 4)));
return;
}
// IPv4
var ipLength = (packet[MACLength] & 0x0F) * 4;
if (ipLength != 0)
{
var ipChecksum = ComputeHeaderIpChecksum(packet, MACLength, ipLength);
packet[MACLength + 10] = (byte)(ipChecksum >> 8);
packet[MACLength + 11] = (byte)(ipChecksum & 0xFF);
}
else
{
source.Log(LogLevel.Error, "Something is wrong - IP packet of len 0");
}
if (interpretedProtocols != null && interpretedProtocols.Contains((TransportLayerProtocol)packet[MACLength + 9]))
{
var payloadStart = MACLength + ipLength;
var protocol = (TransportLayerProtocol)packet[MACLength + 9];
var checksum = GetPacketChecksum(packet, MACLength, payloadStart, protocol != TransportLayerProtocol.ICMP);
switch (protocol)
{
case TransportLayerProtocol.ICMP:
packet[payloadStart + 2] = (byte)((checksum >> 8) & 0xFF);
packet[payloadStart + 3] = (byte)((checksum) & 0xFF);
break;
case TransportLayerProtocol.TCP:
packet[payloadStart + 16] = (byte)((checksum >> 8) & 0xFF);
packet[payloadStart + 17] = (byte)((checksum) & 0xFF);
break;
case TransportLayerProtocol.UDP:
packet[payloadStart + 6] = (byte)((checksum >> 8) & 0xFF);
packet[payloadStart + 7] = (byte)((checksum) & 0xFF);
break;
default:
throw new NotImplementedException();
}
}
}