private void SendResponsePacket(DhcpFormat dhcp)
{
int packetSize = dhcp.Size + UdpFormat.Size +
IPFormat.Size + EthernetFormat.Size;
byte [] packet = new byte [packetSize];
// Write out DHCP packet
int dhcpSize = dhcp.Size;
int dhcpOffset = packet.Length - dhcpSize;
dhcp.Write(packet, dhcpOffset);
// Create UDP Header
UdpFormat.UdpHeader udpHeader = new UdpFormat.UdpHeader();
udpHeader.srcPort = DhcpFormat.ServerPort;
udpHeader.dstPort = DhcpFormat.ClientPort;
udpHeader.length = (ushort)(UdpFormat.Size + dhcpSize);
// Create IP Header
IPFormat.IPHeader ipHeader = new NetStack.Protocols.IPFormat.IPHeader();
ipHeader.SetDefaults(IPFormat.Protocol.UDP);
IPFormat.SetDontFragBit(ipHeader);
ipHeader.Source = ServerAddress;
ipHeader.Destination = IPv4.Broadcast;
ipHeader.totalLength = (ushort)(IPFormat.Size + UdpFormat.Size + dhcpSize);
// Write out IP and Header
int udpOffset = packet.Length - dhcp.Size - UdpFormat.Size;
int ipOffset = udpOffset - IPFormat.Size;
UdpFormat.WriteUdpPacket(packet, ipOffset,
ref ipHeader, ref udpHeader,
packet, dhcpOffset, dhcpSize);
// Add Ethernet Header
EthernetFormat.Write(packet, 0, ServerMac,
EthernetAddress.Broadcast,
EthernetFormat.Protocol.IP);
NetPacket np = new NetPacket(packet);
if (adapter.ReceivePacket(np) == false)
{
Console.WriteLine("Failed to send packet");
SetState(ServerState.Failed);
}
}
internal bool Send(EthernetAddress dstAddr, DhcpFormat !dhcp)
{
int packetSize = dhcp.Size + UdpFormat.Size +
IPFormat.Size + EthernetFormat.Size;
byte [] packet = new byte [packetSize];
// Write out DHCP packet
int dhcpSize = dhcp.Size;
int dhcpOffset = packet.Length - dhcpSize;
dhcp.Write(packet, dhcpOffset);
// Create UDP Header
UdpFormat.UdpHeader udpHeader = new UdpFormat.UdpHeader();
udpHeader.srcPort = DhcpFormat.ClientPort;
udpHeader.dstPort = DhcpFormat.ServerPort;
udpHeader.length = (ushort)(UdpFormat.Size + dhcpSize);
// Create IP Header
IPFormat.IPHeader ipHeader = new NetStack.Protocols.IPFormat.IPHeader();
ipHeader.SetDefaults(IPFormat.Protocol.UDP);
IPFormat.SetDontFragBit(ipHeader);
ipHeader.Source = IPv4.Any;
ipHeader.Destination = IPv4.Broadcast;
ipHeader.totalLength = (ushort)(IPFormat.Size + UdpFormat.Size + dhcpSize);
// Write out IP and Header
int udpOffset = packet.Length - dhcp.Size - UdpFormat.Size;
int ipOffset = udpOffset - IPFormat.Size;
UdpFormat.WriteUdpPacket(packet, ipOffset,
ipHeader, ref udpHeader,
packet, dhcpOffset, dhcpSize);
// Add Ethernet Header
EthernetFormat.Write(packet, 0, adapter.HardwareAddress,
dstAddr, EthernetFormat.PROTOCOL_IP);
NetPacket np = new NetPacket(packet);
return(udpSession.WritePacket(np));
}
public int WriteDataTo(IPv4 remoteAddress,
ushort remotePort,
byte[] !data)
{
if (!IsSessionValidForUserWrite())
{
DebugPrint("WriteDataTo on closed UDP session");
return(-1);
}
int headerSize = EthernetFormat.Size + IPFormat.Size + UdpFormat.Size;
byte[] packet = new byte [headerSize + data.Length];
int ipStart = EthernetFormat.Size;
if (this.LocalAddress == IPv4.Any)
{
this.SetLocalEndPoint(this.LocalAddress, this.LocalPort);
}
UdpFormat.WriteUdpPacket(packet, ipStart,
this.LocalAddress, this.LocalPort,
remoteAddress, remotePort,
data, 0, data.Length);
NetPacket netPacket = new NetPacket(packet);
if (base.PutPacket(outQueue, netPacket, blocking) == false)
{
Core.Log("Failed to enqueue packet for {0}/{1}",
remoteAddress, remotePort);
String msg = String.Format("Failed to enqueue packet for {0}/{1}",
remoteAddress, remotePort);
Tracing.Log(Tracing.Debug, msg);
return(0);
}
return(data.Length);
}
public NetStatus OnProtocolReceive(NetPacket !packet)
{
DebugPrint("Received UDP packet!\n");
UdpFormat.UdpHeader udpHeader = new UdpFormat.UdpHeader();
if (UdpFormat.ReadUdpHeader(packet, out udpHeader) == false)
{
DebugPrint("UDP session received unreadable packet.\n");
return(NetStatus.Code.PROTOCOL_DROP_ERROR);
}
IPFormat.IPHeader !ipHeader = (IPFormat.IPHeader !)packet.OverlapContext;
if (udpHeader.checksum != 0 &&
UdpFormat.IsChecksumValid(ipHeader, udpHeader, packet) == false)
{
DebugPrint("UDP checksum failed. NO cigar and NO packet!");
return(NetStatus.Code.PROTOCOL_DROP_CHKSUM);
}
packet.OverlapContext = ipHeader;
ArrayList udpSessions = Core.Instance().GetSessions(this);
if (udpSessions == null)
{
DebugPrint("No UDP Sessions\n");
return(NetStatus.Code.PROTOCOL_DROP_ERROR);
}
DebugPrint("Packet : Source {0}:{1} Destination {2}:{3}\n",
ipHeader.Source, udpHeader.srcPort,
ipHeader.Destination, udpHeader.dstPort);
lock (udpSessions.SyncRoot) {
foreach (UdpSession !u in udpSessions)
{
DebugPrint("Session : Source {0}:{1} Destination {2}:{3}\n",
u.RemoteAddress, u.RemotePort,
u.LocalAddress, u.LocalPort);
// Match conditions
//
// Bound remote port is zero (not-specified)
// or matches exactly Bound remote IP is Any
// (not-specified) or matches exactly
if ((u.RemoteAddress == IPv4.Any ||
u.RemoteAddress == ipHeader.Source) &&
(u.RemotePort == 0 ||
u.RemotePort == udpHeader.srcPort) &&
(u.LocalAddress == IPv4.Any ||
u.LocalAddress == ipHeader.Destination) &&
(u.LocalPort == udpHeader.dstPort))
{
DebugPrint("Delivered to UDP session\n");
return(u.OnReceive(this, packet, udpHeader));
}
}
}
return(NetStatus.Code.PROTOCOL_DROP_ERROR);
}
/// <summary>
/// Check Ethernet, IP, and UDP headers match those expected.
/// </summary>
private bool ValidHeaders(NetPacket packet)
{
if (packet.Length < NonDhcpHeaderSize)
{
Console.WriteLine("Packet too short");
return(false);
}
//
// Check EthernetHeader
//
EthernetAddress originMac;
EthernetAddress targetMac;
EthernetFormat.Protocol protocol;
EthernetFormat.Read(packet,
out originMac, out targetMac, out protocol);
if (originMac != adapter.HardwareAddress)
{
Console.WriteLine("Bad origin mac: {0}", originMac);
return(false);
}
else if (targetMac != EthernetAddress.Broadcast &&
targetMac != ServerMac)
{
Console.WriteLine("Bad target mac: {0}", targetMac);
return(false);
}
else if (protocol != EthernetFormat.Protocol.IP)
{
Console.WriteLine("Bad encapsulated protocol: {0}", protocol);
return(false);
}
//
// Check IP Header
//
IPFormat.IPHeader ipHeader;
if (IPFormat.ReadIPHeader(packet, out ipHeader) == false)
{
Console.WriteLine("Failed to read IP Header");
return(false);
}
else if (ipHeader.Protocol != IPFormat.Protocol.UDP)
{
Console.WriteLine("Bad encapsulated IP protocol: {0}",
ipHeader.Protocol);
return(false);
}
else if (ipHeader.Source != IPv4.Zero &&
ipHeader.Source != assignedAddress)
{
Console.WriteLine("Bad IP source address: {0}",
ipHeader.Source);
return(false);
}
else if (ipHeader.Destination != IPv4.AllOnes &&
ipHeader.Destination != ServerAddress)
{
Console.WriteLine("Bad IP destination address: {0}",
ipHeader.Destination);
return(false);
}
Console.WriteLine("{0} {1}",
ipHeader.Source, ipHeader.Destination);
//
// Check UDP Header
//
UdpFormat.UdpHeader udpHeader;
if (UdpFormat.ReadUdpHeader(packet, out udpHeader) == false)
{
Console.WriteLine("Failed to read UDP Header");
return(false);
}
else if (udpHeader.srcPort != 68)
{
Console.WriteLine("Bad UDP source port: {0}",
udpHeader.srcPort);
return(false);
}
else if (udpHeader.dstPort != 67)
{
Console.WriteLine("Bad UDP destination port: {0}",
udpHeader.dstPort);
return(false);
}
return(true);
}
