static bool LookupTcp(EthernetWrapper eth, IPv4Wrapper ip, TCPWrapper tcp, bool isOutsideIntf)
{
// for now do a linear traversal >_> // FIXME perform CAM read???
for (uint index = 0; index < ENTRY_COUNT; index++) // FIXME can Kiwi cope with a foreach instead? Would be nicer
{
entry.Load(index);
if (!entry.IsAllocated)
{
continue;
}
Kiwi.Pause();
if (isOutsideIntf)
{
if (entry.DestinationIPAddress == ip.SourceAddress &&
entry.DestinationPort == tcp.SourcePort &&
entry.MasqueradePort == tcp.DestinationPort)
{
#if DEBUG
Console.WriteLine("<><><>> Found matching entry");
#endif
Kiwi.Pause();
return(true);
}
#if DEBUG
else
{
Console.WriteLine("<><><>> Entry {0} doesn't match", index);
Console.WriteLine("<><><>>> {0:x} != {1:x}", entry.DestinationIPAddress, ip.SourceAddress);
Console.WriteLine("<><><>>> {0:x} != {1:x}", entry.DestinationPort, tcp.SourcePort);
Console.WriteLine("<><><>>> {0:x} != {1:x}", entry.MasqueradePort, tcp.DestinationPort);
}
#endif
}
else // isInsideIntf
{
if (entry.SourceIPAddress == ip.SourceAddress &&
entry.SourcePort == tcp.SourcePort &&
entry.DestinationIPAddress == ip.DestinationAddress &&
entry.DestinationPort == tcp.DestinationPort)
{
#if DEBUG
Console.WriteLine("<><><>> Found matching entry");
#endif
Kiwi.Pause();
return(true);
}
#if DEBUG
else
{
Console.WriteLine("<><><>> Entry {0} doesn't match", index);
Console.WriteLine("<><><>>> {0:x} != {1:x}", entry.SourceIPAddress, ip.SourceAddress);
Console.WriteLine("<><><>>> {0:x} != {1:x}", entry.SourcePort, tcp.SourcePort);
Console.WriteLine("<><><>>> {0:x} != {1:x}", entry.DestinationIPAddress, ip.DestinationAddress);
Console.WriteLine("<><><>>> {0:x} != {1:x}", entry.DestinationPort, tcp.DestinationPort);
}
#endif
}
Kiwi.Pause();
}
#if DEBUG
Console.WriteLine("<><><>> Entry search finished with no result.");
#endif
return(false);
}
public static void EntryPoint()
{
// Have to instantiate the wrappers outside of the loop for Kiwi
var eth = new EthernetWrapper(dataplane.tdata);
var ip = new IPv4Wrapper(dataplane.tdata);
var tcp = new TCPWrapper(dataplane.tdata);
var arp = new ARPWrapper(dataplane.tdata);
Kiwi.Pause();
while (true)
{
pkt_size = ReceiveFrame();
Kiwi.Pause();
DebugPrintData();
#if !KIWI
eth = new EthernetWrapper(dataplane.tdata);
ip = new IPv4Wrapper(dataplane.tdata);
tcp = new TCPWrapper(dataplane.tdata);
arp = new ARPWrapper(dataplane.tdata);
#endif
Kiwi.Pause();
if (eth.Ethertype == EthernetWrapper.EtherType.IPv4)
{
switch (ip.Protocol)
{
case IPv4Wrapper.IPProtocol.TCP:
// Handle the TCP packet
tcp.Offset = ip.PayloadOffset;
tcp.Length = ip.PayloadLength;
Kiwi.Pause();
TCP(eth, ip, tcp);
break;
case IPv4Wrapper.IPProtocol.UDP:
break;
case IPv4Wrapper.IPProtocol.ICMP:
break;
default:
#if DEBUG
Console.WriteLine("<><><>> Unknown protocol {0:X}", (byte)ip.Protocol);
#endif
break;
}
}
else if (eth.Ethertype == EthernetWrapper.EtherType.ARP)
{
if (arp.Operation == ARPWrapper.Op.Request &&
arp.HardwareType == ARPWrapper.HwType.Ethernet &&
arp.ProtocolType == (ushort)EthernetWrapper.EtherType.IPv4 &&
arp.HardwareAddressLength == 6 &&
arp.ProtocolAddressLength == 4)
{
Kiwi.Pause(); // Reduces Kiwi compile time
if (arp.TargetProtocolAddress == myInsideIP || arp.TargetProtocolAddress == myOutsideIP) // Request for a MAC I own
{
Kiwi.Pause();
uint intfIp = arp.TargetProtocolAddress;
ulong intfMac = macOfIntf(dataplane.GetReceiveIntf());
// Update arp packet to use as response
arp.Operation = ARPWrapper.Op.Reply;
Kiwi.Pause();
arp.TargetHardwareAddress = arp.SenderHardwareAddress;
Kiwi.Pause();
arp.TargetProtocolAddress = arp.SenderProtocolAddress;
Kiwi.Pause();
arp.SenderHardwareAddress = intfMac;
Kiwi.Pause();
arp.SenderProtocolAddress = intfIp;
Kiwi.Pause();
// Update ethernet fields
eth.DestinationMac = arp.TargetHardwareAddress;
Kiwi.Pause();
eth.SourceMac = intfMac;
Kiwi.Pause();
// Send reply
SetSendIntf(dataplane.GetReceiveIntf());
SendFrame(pkt_size);
}
}
}
Kiwi.Pause();
}
}
static void TCP(EthernetWrapper eth, IPv4Wrapper ip, TCPWrapper tcp)
{
#if DEBUG
Console.WriteLine("<><><>> TCP packet rcx. startByte {0:x}; length {1:X}", tcp.Offset, tcp.Length);
Console.WriteLine("<><><>> Address d: {0:X} {1:X} {2:X}", eth.DestinationMac, ip.DestinationAddress, tcp.DestinationPort);
Console.WriteLine("<><><>> Address s: {0:X} {1:X} {2:X}", eth.SourceMac, ip.SourceAddress, tcp.SourcePort);
Console.WriteLine("<><><>> dataOffset8 {0:X}; payloadOffset8 {1:X}, payloadLength8 {2:X}", tcp.DataOffset * 4, tcp.PayloadOffset, tcp.PayloadLength);
Kiwi.Pause();
#endif
// Get which intf the packet arrived on
byte incoming = dataplane.GetReceiveIntf();
bool isOutsideIntf = IsOutsideIntf(incoming) && ip.DestinationAddress == myOutsideIP;
bool isInsideIntf = IsInsideIntf(incoming);
#if DEBUG
Console.WriteLine("<><><>> incoming {0:x} isOutsideIntf {1} isInsideIntf {2}", incoming, isOutsideIntf, isInsideIntf);
#endif
Kiwi.Pause();
if (isInsideIntf || isOutsideIntf)
{
// Find a matching entry if one exists
bool found = LookupTcp(eth, ip, tcp, isOutsideIntf);
// Track incremental updates to the checksum as we change data
int ipChecksum = ~ip.HeaderChecksum & 0xFFFF;
int tcpChecksum = ~tcp.Checksum & 0xFFFF;
#if DEBUG
Console.WriteLine("<><><>> 169 checksums {0:x}/{1:x}", ipChecksum, tcpChecksum);
#endif
Kiwi.Pause();
if (isInsideIntf) // Packet going from inside to outside
{
#if DEBUG
Console.WriteLine("<><><>> Packet outbound");
#endif
// If the packet is outbound and there is no existing entry, create one if it's a Syn packet
if (!found && tcp.HasFlag(TCPWrapper.Flag.Syn))
{
#if DEBUG
Console.WriteLine("<><><>> Syn");
#endif
// 'Allocate' new entry
entry.Load(nextEntry); // FIXME find an unallocated index
// Increment nextEntry pointer
nextEntry++;
if (nextEntry >= ENTRY_COUNT) // FIXME wrap :S
{
nextEntry = 0;
}
Kiwi.Pause();
// Save details //FIXME save MACs?
entry.SourceIPAddress = ip.SourceAddress;
Kiwi.Pause();
entry.DestinationIPAddress = ip.DestinationAddress;
Kiwi.Pause();
entry.SourcePort = tcp.SourcePort;
Kiwi.Pause();
entry.DestinationPort = tcp.DestinationPort;
Kiwi.Pause();
entry.MasqueradePort = BitUtil.SwitchEndianness(nextPort++);
Kiwi.Pause();
entry.InsideIntf = dataplane.GetReceiveIntf();
Kiwi.Pause();
entry.OutsideIntf = NAT.outsidePort; // NOTE this also marks it as allocated
Kiwi.Pause();
entry.Save();
Kiwi.Pause();
found = true;
#if DEBUG
Console.WriteLine("<><><>> New entry allocated");
#endif
}
Kiwi.Pause();
if (found)
{
#if DEBUG
Console.WriteLine("<><><>> Changing packet fields");
Console.WriteLine("<><><>> entry d: {0:X} {1:X}", entry.DestinationIPAddress, entry.DestinationPort);
Console.WriteLine("<><><>> entry s: {0:X} {1:X}", entry.SourceIPAddress, entry.SourcePort);
Console.WriteLine("<><><>> entry i: {0:X} {1:X}", entry.InsideIntf, entry.OutsideIntf);
Console.WriteLine("<><><>> entry m: {0:X}", entry.MasqueradePort);
#endif
// Change destination MAC
eth.DestinationMac = nextHopMacOfIntf(entry.OutsideIntf);
Kiwi.Pause();
// Change source MAC
eth.SourceMac = macOfIntf(entry.OutsideIntf);
Kiwi.Pause();
// Change source IP address
#if DEBUG
Console.WriteLine("<><><>> 226 checksums {0:x}/{1:x}", ipChecksum, tcpChecksum);
#endif
ip.SourceAddress = BitUtil.ChangeValueInChecksum(ip.SourceAddress, myOutsideIP, ref ipChecksum, ref tcpChecksum); // FIXME not particularly elegant
Kiwi.Pause();
#if DEBUG
Console.WriteLine("<><><>> 230 checksums {0:x}/{1:x}", ipChecksum, tcpChecksum);
#endif
// Change source TCP port
#if DEBUG
Console.WriteLine("<><><>> 235 checksums {0:x}/{1:x}", ipChecksum, tcpChecksum);
#endif
tcp.SourcePort = BitUtil.ChangeValueInChecksum(tcp.SourcePort, entry.MasqueradePort, ref tcpChecksum);
Kiwi.Pause();
#if DEBUG
Console.WriteLine("<><><>> 239 checksums {0:x}/{1:x}", ipChecksum, tcpChecksum);
#endif
// Forward on correct intf
SetSendIntf(entry.OutsideIntf);
Kiwi.Pause();
}
}
else if (found) // isOutsideIntf // Packet going from outside to inside
{
#if DEBUG
Console.WriteLine("<><><>> Packet inbound");
Console.WriteLine("<><><>> Changing packet fields");
Console.WriteLine("<><><>> entry d: {0:X} {1:X}", entry.DestinationIPAddress, entry.DestinationPort);
Console.WriteLine("<><><>> entry s: {0:X} {1:X}", entry.SourceIPAddress, entry.SourcePort);
Console.WriteLine("<><><>> entry i: {0:X} {1:X}", entry.InsideIntf, entry.OutsideIntf);
Console.WriteLine("<><><>> entry m: {0:X}", entry.MasqueradePort);
#endif
// Change destination MAC
eth.DestinationMac = nextHopMacOfIntf(entry.InsideIntf);
Kiwi.Pause();
// Change source MAC
eth.SourceMac = macOfIntf(entry.InsideIntf);
Kiwi.Pause();
// Change destination IP address
#if DEBUG
Console.WriteLine("<><><>> 263 checksums {0:x}/{1:x}", ipChecksum, tcpChecksum);
#endif
ip.DestinationAddress = BitUtil.ChangeValueInChecksum(ip.DestinationAddress, entry.SourceIPAddress, ref ipChecksum, ref tcpChecksum);
Kiwi.Pause();
#if DEBUG
Console.WriteLine("<><><>> 267 checksums {0:x}/{1:x}", ipChecksum, tcpChecksum);
#endif
// Change destination TCP port
#if DEBUG
Console.WriteLine("<><><>> 272 checksums {0:x}/{1:x}", ipChecksum, tcpChecksum);
#endif
tcp.DestinationPort = BitUtil.ChangeValueInChecksum(tcp.DestinationPort, entry.SourcePort, ref tcpChecksum);
Kiwi.Pause();
#if DEBUG
Console.WriteLine("<><><>> 276 checksums {0:x}/{1:x}", ipChecksum, tcpChecksum);
#endif
// Forward on correct intf
SetSendIntf(entry.InsideIntf);
Kiwi.Pause();
}
Kiwi.Pause();
if (found)
{
// Add carry bits and write new IP checksum value
ip.HeaderChecksum = BitUtil.GetChecksum(ipChecksum);
Kiwi.Pause();
// Add carry bits and write new TCP checksum value
tcp.Checksum = BitUtil.GetChecksum(tcpChecksum);
Kiwi.Pause();
Kiwi.Pause();
#if DEBUG
Console.WriteLine("<><><>> Sending frame");
#if KIWI
for (int i = 0; i < dataplane.tdata.Length; i++)
{
Console.WriteLine("<><><>>> {0:x}", dataplane.tdata[i]);
if (dataplane.tlast[i])
{
break;
}
Kiwi.Pause();
}
#endif
Console.WriteLine();
#endif
SendFrame(pkt_size);
}
}
}
