///<summary>This sends an ICMP Request to the specified address, we want
///him to respond to us, so we can guarantee that by pretending to be the
///Server (i.e. x.y.z.1). We'll get a response in our main thread.</summary>
///<param name="dest_ip">Destination IP of our request.</summary>
protected virtual void SendICMPRequest(MemBlock dest_ip)
{
if(_dhcp_server == null) {
return;
}
MemBlock ether_addr = null;
if(!_ip_to_ether.TryGetValue(dest_ip, out ether_addr)) {
ether_addr = EthernetPacket.BroadcastAddress;
}
ICMPPacket icmp = new ICMPPacket(ICMPPacket.Types.EchoRequest);
IPPacket ip = new IPPacket(IPPacket.Protocols.ICMP, _dhcp_server.ServerIP,
dest_ip, icmp.Packet);
EthernetPacket ether = new EthernetPacket(ether_addr,
EthernetPacket.UnicastAddress, EthernetPacket.Types.IP, ip.ICPacket);
Ethernet.Send(ether.ICPacket);
}
/// <summary>Writes an IPPacket as is to the TAP device.</summary>
/// <param name="packet">The IPPacket!</param>
protected virtual void WriteIP(ICopyable packet)
{
MemBlock mp = packet as MemBlock;
if(mp == null) {
mp = MemBlock.Copy(packet);
}
IPPacket ipp = new IPPacket(mp);
MemBlock dest = null;
if(!_ip_to_ether.TryGetValue(ipp.DestinationIP, out dest)) {
return;
}
EthernetPacket res_ep = new EthernetPacket(_ip_to_ether[ipp.DestinationIP],
EthernetPacket.UnicastAddress, EthernetPacket.Types.IP, mp);
Ethernet.Send(res_ep.ICPacket);
}
/// <summary>This is used to process a dhcp packet on the node side, that
/// includes placing data such as the local Brunet Address, Ipop Namespace,
/// and other optional parameters in our request to the dhcp server. When
/// receiving the results, if it is successful, the results are written to
/// the TAP device.</summary>
/// <param name="ipp"> The IPPacket that contains the DHCP Request</param>
/// <param name="dhcp_params"> an object containing any extra parameters for
/// the dhcp server</param>
/// <returns> true on if dhcp is supported.</returns>
protected virtual bool HandleDHCP(IPPacket ipp)
{
UDPPacket udpp = new UDPPacket(ipp.Payload);
DHCPPacket dhcp_packet = new DHCPPacket(udpp.Payload);
MemBlock ether_addr = dhcp_packet.chaddr;
if(_dhcp_config == null) {
return true;
}
DHCPServer dhcp_server = CheckOutDHCPServer(ether_addr);
if(dhcp_server == null) {
return true;
}
MemBlock last_ip = null;
_ether_to_ip.TryGetValue(ether_addr, out last_ip);
byte[] last_ipb = (last_ip == null) ? null : (byte[]) last_ip;
WaitCallback wcb = delegate(object o) {
ProtocolLog.WriteIf(IpopLog.DHCPLog, String.Format(
"Attemping DHCP for: {0}", Utils.MemBlockToString(ether_addr, '.')));
DHCPPacket rpacket = null;
try {
rpacket = dhcp_server.ProcessPacket(dhcp_packet,
Brunet.Address.ToString(), last_ipb);
} catch(Exception e) {
ProtocolLog.WriteIf(IpopLog.DHCPLog, e.Message);
CheckInDHCPServer(dhcp_server);
return;
}
/* Check our allocation to see if we're getting a new address */
MemBlock new_addr = rpacket.yiaddr;
UpdateMapping(ether_addr, new_addr);
MemBlock destination_ip = ipp.SourceIP;
if(destination_ip.Equals(IPPacket.ZeroAddress)) {
destination_ip = IPPacket.BroadcastAddress;
}
UDPPacket res_udpp = new UDPPacket(_dhcp_server_port, _dhcp_client_port, rpacket.Packet);
IPPacket res_ipp = new IPPacket(IPPacket.Protocols.UDP, rpacket.siaddr,
destination_ip, res_udpp.ICPacket);
EthernetPacket res_ep = new EthernetPacket(ether_addr, EthernetPacket.UnicastAddress,
EthernetPacket.Types.IP, res_ipp.ICPacket);
Ethernet.Send(res_ep.ICPacket);
CheckInDHCPServer(dhcp_server);
};
ThreadPool.QueueUserWorkItem(wcb);
return true;
}
/// <summary>This method handles IPPackets that come from the TAP Device, i.e.,
/// local system.</summary>
/// <remarks>Currently this supports HandleMulticast (ip[0] >= 244 &&
/// ip[0]<=239), HandleDNS (dport = 53 and ip[3] == 1), dhcp (sport 68 and
/// dport 67.</remarks>
/// <param name="packet">The packet from the TAP device</param>
/// <param name="from"> This should always be the tap device</param>
protected virtual void HandleIPOut(EthernetPacket packet, ISender ret)
{
IPPacket ipp = new IPPacket(packet.Payload);
if(IpopLog.PacketLog.Enabled) {
ProtocolLog.Write(IpopLog.PacketLog, String.Format(
"Outgoing {0} packet::IP src: {1}, IP dst: {2}",
ipp.Protocol, ipp.SSourceIP, ipp.SDestinationIP));
}
if(!IsLocalIP(ipp.SourceIP)) {
HandleNewStaticIP(packet.SourceAddress, ipp.SourceIP);
return;
}
if(ipp.DestinationIP[0] >= 224 && ipp.DestinationIP[0] <= 239) {
if(HandleMulticast(ipp)) {
return;
}
}
switch(ipp.Protocol) {
case IPPacket.Protocols.UDP:
UDPPacket udpp = new UDPPacket(ipp.Payload);
if(udpp.SourcePort == _dhcp_client_port && udpp.DestinationPort == _dhcp_server_port) {
if(HandleDHCP(ipp)) {
return;
}
} else if(udpp.DestinationPort == 53 &&ipp.DestinationIP.Equals(_dhcp_server.ServerIP)) {
if(HandleDNS(ipp)) {
return;
}
}
break;
}
if(HandleOther(ipp)) {
return;
}
if(_dhcp_server == null || ipp.DestinationIP.Equals(_dhcp_server.ServerIP)) {
return;
}
AHAddress target = (AHAddress) _address_resolver.Resolve(ipp.DestinationIP);
if (target != null) {
if(IpopLog.PacketLog.Enabled) {
ProtocolLog.Write(IpopLog.PacketLog, String.Format(
"Brunet destination ID: {0}", target));
}
SendIP(target, packet.Payload);
}
}
/// <summary>Parses ARP Packets and writes to the Ethernet the translation.</summary>
/// <remarks>IpopRouter makes nodes think they are in the same Layer 2 network
/// so that two nodes in the same network can communicate directly with each
/// other. IpopRouter masquerades for those that are not local.</remarks>
/// <param name="ep">The Ethernet packet to translate</param>
protected virtual void HandleARP(MemBlock packet)
{
// Can't do anything until we have network connectivity!
if(_dhcp_server == null) {
return;
}
ARPPacket ap = new ARPPacket(packet);
// Not in our range!
if(!_dhcp_server.IPInRange((byte[]) ap.TargetProtoAddress) &&
!_dhcp_server.IPInRange((byte[]) ap.SenderProtoAddress))
{
ProtocolLog.WriteIf(IpopLog.ARP, String.Format("Bad ARP request from {0} for {1}",
Utils.MemBlockToString(ap.SenderProtoAddress, '.'),
Utils.MemBlockToString(ap.TargetProtoAddress, '.')));
return;
}
if(ap.Operation == ARPPacket.Operations.Reply) {
// This would be a unsolicited ARP
if(ap.TargetProtoAddress.Equals(IPPacket.BroadcastAddress) &&
!ap.SenderHWAddress.Equals(EthernetPacket.BroadcastAddress))
{
HandleNewStaticIP(ap.SenderHWAddress, ap.SenderProtoAddress);
}
return;
}
// We only support request operation hereafter
if(ap.Operation != ARPPacket.Operations.Request) {
return;
}
// Must return nothing if the node is checking availability of IPs
// Or he is looking himself up.
if(_ip_to_ether.ContainsKey(ap.TargetProtoAddress) ||
ap.SenderProtoAddress.Equals(IPPacket.BroadcastAddress) ||
ap.SenderProtoAddress.Equals(IPPacket.ZeroAddress))
{
return;
}
// We shouldn't be returning these messages if no one exists at that end
// point
if(!ap.TargetProtoAddress.Equals(MemBlock.Reference(_dhcp_server.ServerIP))) {
Address baddr = _address_resolver.Resolve(ap.TargetProtoAddress);
if(Brunet.Address.Equals(baddr) || baddr == null) {
return;
}
}
ProtocolLog.WriteIf(IpopLog.ARP, String.Format("Sending ARP response for: {0}",
Utils.MemBlockToString(ap.TargetProtoAddress, '.')));
ARPPacket response = ap.Respond(EthernetPacket.UnicastAddress);
EthernetPacket res_ep = new EthernetPacket(ap.SenderHWAddress,
EthernetPacket.UnicastAddress, EthernetPacket.Types.ARP,
response.ICPacket);
Ethernet.Send(res_ep.ICPacket);
}
/// <summary> This method handles all incoming packets into the IpopNode, both
/// abroad and local. This is done to reduce unnecessary extra classes and
/// circular dependencies. This method probably shouldn't be called
/// directly.</summary>
/// <param name="b"> The incoming packet</param>
/// <param name="ret">An ISender to return data from the original sender.</param>
/// <param name="state">always will be null</param>
public void HandleData(MemBlock b, ISender ret, object state)
{
if(ret is Ethernet) {
EthernetPacket ep = new EthernetPacket(b);
switch (ep.Type) {
case EthernetPacket.Types.ARP:
HandleARP(ep.Payload);
break;
case EthernetPacket.Types.IP:
HandleIPOut(ep, ret);
break;
}
}
else {
HandleIPIn(b, ret);
}
}
/// <summary>Writes an IPPacket as is to the TAP device.</summary>
/// <param name="packet">The IPPacket!</param>
protected virtual void WriteIP(ICopyable packet)
{
MemBlock mp = packet as MemBlock;
if(mp == null) {
mp = MemBlock.Copy(packet);
}
IPPacket ipp = new IPPacket(mp);
MemBlock dest = null;
if(!_ip_to_ether.TryGetValue(ipp.DestinationIP, out dest)) {
if(ipp.DestinationIP[0] >= 224 && ipp.DestinationIP[0] <= 239) {
dest = EthernetPacket.GetMulticastEthernetAddress(ipp.DestinationIP);
} else if(ipp.DestinationIP[3] == 255){
dest = EthernetPacket.BroadcastAddress;
} else {
return;
}
}
EthernetPacket res_ep = new EthernetPacket(dest,
EthernetPacket.UnicastAddress, EthernetPacket.Types.IP, mp);
Ethernet.Send(res_ep.ICPacket);
}
/// <summary>Parses Arp Packets and writes to the Ethernet the translation.</summary>
/// <remarks>IpopRouter makes nodes think they are in the same Layer 2 network
/// so that two nodes in the same network can communicate directly with each
/// other. IpopRouter masquerades for those that are not local.</remarks>
/// <param name="ep">The Ethernet packet to translate</param>
protected virtual void HandleArp(MemBlock packet)
{
// Can't do anything until we have network connectivity!
if(_dhcp_server == null) {
return;
}
ArpPacket ap = new ArpPacket(packet);
// Not in our range!
if(!_dhcp_server.IPInRange((byte[]) ap.TargetProtoAddress) &&
!_dhcp_server.IPInRange((byte[]) ap.SenderProtoAddress))
{
ProtocolLog.WriteIf(IpopLog.Arp, String.Format("Bad Arp request from {0} for {1}",
Utils.MemBlockToString(ap.SenderProtoAddress, '.'),
Utils.MemBlockToString(ap.TargetProtoAddress, '.')));
return;
}
if(ap.Operation == ArpPacket.Operations.Reply) {
// This would be a unsolicited Arp
if(ap.TargetProtoAddress.Equals(IPPacket.BroadcastAddress) &&
!ap.SenderHWAddress.Equals(EthernetPacket.BroadcastAddress))
{
HandleNewStaticIP(ap.SenderHWAddress, ap.SenderProtoAddress);
}
return;
}
// We only support request operation hereafter
if(ap.Operation != ArpPacket.Operations.Request) {
return;
}
// Must return nothing if the node is checking availability of IPs
// Or he is looking himself up.
if(_ip_to_ether.ContainsKey(ap.TargetProtoAddress) ||
ap.SenderProtoAddress.Equals(IPPacket.BroadcastAddress) ||
ap.SenderProtoAddress.Equals(IPPacket.ZeroAddress))
{
return;
}
if(!ap.TargetProtoAddress.Equals(MemBlock.Reference(_dhcp_server.ServerIP))) {
// Do not return messages if there is no connection to the remote address
Address baddr = null;
try {
baddr = _address_resolver.Resolve(ap.TargetProtoAddress);
} catch(AddressResolutionException ex) {
if(ex.Issue != AddressResolutionException.Issues.DoesNotExist) {
throw;
}
// Otherwise nothing to do, mapping doesn't exist...
}
if(AppNode.Node.Address.Equals(baddr) || baddr == null) {
ProtocolLog.WriteIf(IpopLog.Arp, String.Format("No mapping for: {0}",
Utils.MemBlockToString(ap.TargetProtoAddress, '.')));
return;
}
if(!_conn_handler.ContainsAddress(baddr)) {
ProtocolLog.WriteIf(IpopLog.Arp, String.Format(
"No connection to {0} for {1}", baddr,
Utils.MemBlockToString(ap.TargetProtoAddress, '.')));
_conn_handler.ConnectTo(baddr);
return;
}
}
ProtocolLog.WriteIf(IpopLog.Arp, String.Format("Sending Arp response for: {0}",
Utils.MemBlockToString(ap.TargetProtoAddress, '.')));
ArpPacket response = ap.Respond(EthernetPacket.UnicastAddress);
EthernetPacket res_ep = new EthernetPacket(ap.SenderHWAddress,
EthernetPacket.UnicastAddress, EthernetPacket.Types.Arp,
response.ICPacket);
Ethernet.Send(res_ep.ICPacket);
}
/// <summary>This method handles IPPackets that come from the TAP Device, i.e.,
/// local system.</summary>
/// <remarks>Currently this supports HandleMulticast (ip[0] >= 244 &&
/// ip[0]<=239), HandleDns (dport = 53 and ip[3] == 1), dhcp (sport 68 and
/// dport 67.</remarks>
/// <param name="packet">The packet from the TAP device</param>
/// <param name="from"> This should always be the tap device</param>
protected virtual void HandleIPOut(EthernetPacket packet, ISender ret) {
IPPacket ipp = new IPPacket(packet.Payload);
if(IpopLog.PacketLog.Enabled) {
ProtocolLog.Write(IpopLog.PacketLog, String.Format(
"Outgoing {0} packet::IP src: {1}, IP dst: {2}",
ipp.Protocol, ipp.SSourceIP, ipp.SDestinationIP));
}
if(!IsLocalIP(ipp.SourceIP)) {
// This really ought to have been caught in ARP, but just in case...
HandleNewStaticIP(packet.SourceAddress, ipp.SourceIP);
return;
}
UdpPacket udpp = null;
switch(ipp.Protocol) {
case IPPacket.Protocols.Udp:
udpp = new UdpPacket(ipp.Payload);
if(udpp.SourcePort == _dhcp_client_port && udpp.DestinationPort == _dhcp_server_port) {
if(HandleDhcp(ipp)) {
return;
}
} else if(udpp.DestinationPort == 53 && ipp.DestinationIP.Equals(_dhcp_server.ServerIP)) {
if(HandleDns(ipp)) {
return;
}
}
break;
}
if(ipp.DestinationIP[0] >= 224 && ipp.DestinationIP[0] <= 239) {
// We don't want to send Brunet multicast packets over IPOP!
if(udpp != null && udpp.DestinationPort == IPHandler.mc_port) {
return;
} else if(HandleMulticast(ipp)) {
return;
}
}
if(ipp.DestinationIP.Equals(IPPacket.BroadcastAddress)) {
if(HandleBroadcast(ipp)) {
return;
}
}
if(_dhcp_server == null || ipp.DestinationIP.Equals(_dhcp_server.ServerIP)) {
return;
}
Address target = null;
try {
target = _address_resolver.Resolve(ipp.DestinationIP) as AHAddress;
} catch(AddressResolutionException ex) {
if(ex.Issue != AddressResolutionException.Issues.DoesNotExist) {
throw;
}
// Otherwise nothing to do, mapping doesn't exist...
}
if(target != null) {
SendIP(target, packet.Payload);
}
}