internal byte[] BuildSendData(DhcpMessgeType msgType, IPAddress clientIp)
{
if (!IsBuiltTobeSent)
{
packet.ApplySettings(msgType, RelatedServer._settings, clientIp);
IsBuiltTobeSent = true;
return(packet.ToArray());
}
throw new Exception("Dhcp packet data is already built.");
}
private void SendDhcpMessage(string dest, DhcpMessgeType msgType, DhcpData data, OwnedIpAddress newClient)
{
try
{
var dataToSend = data.BuildSendData(msgType, newClient.Ip);
udpListener.SendData(dest, dataToSend);
}
catch (Exception e)
{
ErrorRaised?.Invoke(this, new ErrorMessageEventArgs {
Message = e.Message
});
}
}
// override method for broadcast
private void SendDhcpMessage(DhcpMessgeType msgType, DhcpData data, OwnedIpAddress newClient)
{
SendDhcpMessage(IPAddress.Broadcast.ToString(), msgType, data, newClient);
}
internal void ApplyOptionSettings(DhcpMessgeType messageType, DhcpServerSettings server)
{
try
{
var oldMsgType = GetDhcpMessageType();
//erase the options array, and set the message type to ack
byte[] newOptions = null;
CreateOptionElement(DhcpOptionType.DHCPMessageType, new byte[] { (byte)messageType }, ref newOptions);
//server identifier, my IP
var myIp = server.ServerIp.GetAddressBytes();
CreateOptionElement(DhcpOptionType.ServerIdentifier, myIp, ref newOptions);
//lease time
var leaseTime = new byte[4];
leaseTime[3] = (byte)(server.LeaseTime);
leaseTime[2] = (byte)(server.LeaseTime >> 8);
leaseTime[1] = (byte)(server.LeaseTime >> 16);
leaseTime[0] = (byte)(server.LeaseTime >> 24);
switch (messageType)
{
case DhcpMessgeType.DHCP_NAK:
goto EndOption;
case DhcpMessgeType.DHCP_OFFER:
CreateOptionElement(DhcpOptionType.IPAddressLeaseTime, leaseTime, ref newOptions);
CreateOptionElement(DhcpOptionType.RenewalTimeValue_T1, leaseTime, ref newOptions);
CreateOptionElement(DhcpOptionType.RebindingTimeValue_T2, leaseTime, ref newOptions);
break;
case DhcpMessgeType.DHCP_ACK:
if (oldMsgType == DhcpMessgeType.DHCP_INFORM)
{
break;
}
CreateOptionElement(DhcpOptionType.IPAddressLeaseTime, leaseTime, ref newOptions);
CreateOptionElement(DhcpOptionType.RenewalTimeValue_T1, leaseTime, ref newOptions);
CreateOptionElement(DhcpOptionType.RebindingTimeValue_T2, leaseTime, ref newOptions);
break;
}
// look for the parameter request list
var reqList = GetOptionData(DhcpOptionType.ParameterRequestList);
// reqList contains the option data in a byte that is requested by the unit
foreach (var i in reqList)
{
byte[] t1 = null;
switch ((DhcpOptionType)i)
{
case DhcpOptionType.SubnetMask:
t1 = server.SubnetMask.GetAddressBytes();
break;
case DhcpOptionType.Router when server.RouterIp != null:
t1 = server.RouterIp.GetAddressBytes();
break;
case DhcpOptionType.DomainNameServer when server.DomainIp != null:
t1 = server.DomainIp.GetAddressBytes();
break;
case DhcpOptionType.DomainName when server.ServerName != null:
t1 = Encoding.ASCII.GetBytes(server.ServerName);
break;
case DhcpOptionType.LogServer:
break;
case DhcpOptionType.NetBIOSoverTCPIPNameServer:
break;
case DhcpOptionType.Pad:
break;
case DhcpOptionType.TimeOffset:
break;
case DhcpOptionType.TimeServer:
break;
case DhcpOptionType.NameServer:
break;
case DhcpOptionType.CookieServer:
break;
case DhcpOptionType.LPRServer:
break;
case DhcpOptionType.ImpressServer:
break;
case DhcpOptionType.ResourceLocServer:
break;
case DhcpOptionType.HostName:
break;
case DhcpOptionType.BootFileSize:
break;
case DhcpOptionType.MeritDump:
break;
case DhcpOptionType.SwapServer:
break;
case DhcpOptionType.RootPath:
break;
case DhcpOptionType.ExtensionsPath:
break;
case DhcpOptionType.IpForwarding:
break;
case DhcpOptionType.NonLocalSourceRouting:
break;
case DhcpOptionType.PolicyFilter:
break;
case DhcpOptionType.MaximumDatagramReAssemblySize:
break;
case DhcpOptionType.DefaultIPTimeToLive:
break;
case DhcpOptionType.PathMTUAgingTimeout:
break;
case DhcpOptionType.PathMTUPlateauTable:
break;
case DhcpOptionType.InterfaceMTU:
break;
case DhcpOptionType.AllSubnetsAreLocal:
break;
case DhcpOptionType.BroadcastAddress:
break;
case DhcpOptionType.PerformMaskDiscovery:
break;
case DhcpOptionType.MaskSupplier:
break;
case DhcpOptionType.PerformRouterDiscovery:
break;
case DhcpOptionType.RouterSolicitationAddress:
break;
case DhcpOptionType.StaticRoute:
break;
case DhcpOptionType.TrailerEncapsulation:
break;
case DhcpOptionType.ARPCacheTimeout:
break;
case DhcpOptionType.EthernetEncapsulation:
break;
case DhcpOptionType.TCPDefaultTTL:
break;
case DhcpOptionType.TCPKeepaliveInterval:
break;
case DhcpOptionType.TCPKeepaliveGarbage:
break;
case DhcpOptionType.NetworkInformationServiceDomain:
break;
case DhcpOptionType.NetworkInformationServers:
break;
case DhcpOptionType.NetworkTimeProtocolServers:
break;
case DhcpOptionType.VendorSpecificInformation:
break;
case DhcpOptionType.NetBIOSoverTCPIPDatagramDistributionServer:
break;
case DhcpOptionType.NetBIOSoverTCPIPNodeType:
break;
case DhcpOptionType.NetBIOSoverTCPIPScope:
break;
case DhcpOptionType.XWindowSystemFontServer:
break;
case DhcpOptionType.XWindowSystemDisplayManager:
break;
case DhcpOptionType.RequestedIPAddress:
break;
case DhcpOptionType.IPAddressLeaseTime:
break;
case DhcpOptionType.OptionOverload:
break;
case DhcpOptionType.DHCPMessageType:
break;
case DhcpOptionType.ParameterRequestList:
break;
case DhcpOptionType.Message:
break;
case DhcpOptionType.MaximumDHCPMessageSize:
break;
case DhcpOptionType.RenewalTimeValue_T1:
break;
case DhcpOptionType.RebindingTimeValue_T2:
break;
case DhcpOptionType.Vendorclassidentifier:
break;
case DhcpOptionType.ClientIdentifier:
break;
case DhcpOptionType.NetworkInformationServicePlusDomain:
break;
case DhcpOptionType.NetworkInformationServicePlusServers:
break;
case DhcpOptionType.TFTPServerName:
break;
case DhcpOptionType.BootfileName:
break;
case DhcpOptionType.MobileIPHomeAgent:
break;
case DhcpOptionType.SMTPServer:
break;
case DhcpOptionType.POP3Server:
break;
case DhcpOptionType.NNTPServer:
break;
case DhcpOptionType.DefaultWWWServer:
break;
case DhcpOptionType.DefaultFingerServer:
break;
case DhcpOptionType.DefaultIRCServer:
break;
case DhcpOptionType.StreetTalkServer:
break;
case DhcpOptionType.STDAServer:
break;
case DhcpOptionType.End:
break;
}
if (t1 != null)
{
CreateOptionElement((DhcpOptionType)i, t1, ref newOptions);
}
}
EndOption:
//create the end option
Array.Resize(ref newOptions, newOptions.Length + 1);
Array.Copy(new byte[] { (byte)DhcpOptionType.End }, 0, newOptions, newOptions.Length - 1, 1);
options = newOptions;
}
catch (Exception e)
{
throw new Exception($@"{GetType().FullName}.{MethodBase.GetCurrentMethod()}:{e.Message}");
}
}
public void ApplySettings(DhcpMessgeType msgType, DhcpServerSettings server, IPAddress clientIp)
{
switch (msgType)
{
case DhcpMessgeType.DHCP_OFFER:
op = (byte)BootMessageType.BootReply;
// htype
// hlen
hops = 0;
// xid from client DHCPDISCOVER message
secs.FillZero();
ciaddr.FillZero();
yiaddr = IPAddress.Parse(clientIp.ToString()).GetAddressBytes();
siaddr = IPAddress.Parse("0.0.0.0").GetAddressBytes();
// flags from client DHCPDISCOVER message
// giaddr from client DHCPDISCOVER message
// chaddr from client DHCPDISCOVER message
sname.FillZero();
file.FillZero();
options.ApplyOptionSettings(msgType, server);
break;
case DhcpMessgeType.DHCP_ACK:
op = (byte)BootMessageType.BootReply;
// htype
// hlen
hops = 0;
// xid from client DHCPREQUEST message
secs.FillZero();
ciaddr.FillZero();
if (options.GetDhcpMessageType() == DhcpMessgeType.DHCP_INFORM)
{
yiaddr.FillZero();
}
else
{
yiaddr = IPAddress.Parse(clientIp.ToString()).GetAddressBytes();
}
siaddr = IPAddress.Parse("0.0.0.0").GetAddressBytes();
// flags from client DHCPREQUEST message
// giaddr from client DHCPREQUEST message
// chaddr from client DHCPREQUEST message
sname.FillZero();
file.FillZero();
options.ApplyOptionSettings(msgType, server);
break;
case DhcpMessgeType.DHCP_NAK:
op = (byte)BootMessageType.BootReply;
// htype
// hlen
hops = 0;
// xid from client DHCPREQUEST message
secs.FillZero();
// ciaddr from client DHCPREQUEST message
yiaddr.FillZero();
siaddr.FillZero();
// flags from client DHCPREQUEST message
// giaddr from client DHCPREQUEST message
// chaddr from client DHCPREQUEST message
sname.FillZero();
file.FillZero();
options.ApplyOptionSettings(msgType, server);
break;
}
}
