/// <summary>
/// Sends DHCP reply
/// </summary>
/// <param name="msgType">Type of DHCP message to send</param>
/// <param name="ip">IP for client</param>
/// <param name="replyData">Reply options (will be sent if requested)</param>
public void SendDHCPReply(DHCPMsgType msgType, IPAddress ip, DHCPReplyOptions replyData)
{
SendDHCPReply(msgType, ip, replyData, null);
}
private byte[] CreateOptionStruct(DHCPMsgType msgType, DHCPReplyOptions replyOptions, Dictionary <DHCPOption, byte[]> otherForceOptions)
{
byte[] resultOptions = null;
// Requested options
var reqList = GetRequestedOptionsList();
// Option82?
var relayInfo = this.GetOptionData(DHCPOption.RelayInfo);
CreateOptionElement(ref resultOptions, DHCPOption.DHCPMessageTYPE, new byte[] { (byte)msgType });
// Server identifier - our IP address
if ((replyOptions != null) && (replyOptions.ServerIdentifier != null))
{
CreateOptionElement(ref resultOptions, DHCPOption.ServerIdentifier, replyOptions.ServerIdentifier.GetAddressBytes());
}
// Requested options
if ((reqList != null) && (replyOptions != null))
{
foreach (DHCPOption i in reqList)
{
byte[] optionData = null;
// If it's force option - ignore it. We'll send it later.
if ((otherForceOptions != null) && (otherForceOptions.TryGetValue(i, out optionData)))
{
continue;
}
switch (i)
{
case DHCPOption.SubnetMask:
if (replyOptions.SubnetMask != null)
{
optionData = replyOptions.SubnetMask.GetAddressBytes();
}
break;
case DHCPOption.Router:
if (replyOptions.RouterIP != null)
{
optionData = replyOptions.RouterIP.GetAddressBytes();
}
break;
case DHCPOption.DomainNameServers:
if (replyOptions.DomainNameServers != null)
{
optionData = new byte[] { };
foreach (var dns in replyOptions.DomainNameServers)
{
var dnsserv = dns.GetAddressBytes();
Array.Resize(ref optionData, optionData.Length + 4);
Array.Copy(dnsserv, 0, optionData, optionData.Length - 4, 4);
}
}
break;
case DHCPOption.DomainName:
if (!string.IsNullOrEmpty(replyOptions.DomainName))
{
optionData = System.Text.Encoding.ASCII.GetBytes(replyOptions.DomainName);
}
break;
case DHCPOption.ServerIdentifier:
if (replyOptions.ServerIdentifier != null)
{
optionData = replyOptions.ServerIdentifier.GetAddressBytes();
}
break;
case DHCPOption.LogServer:
if (replyOptions.LogServerIP != null)
{
optionData = replyOptions.LogServerIP.GetAddressBytes();
}
break;
case DHCPOption.StaticRoutes:
case DHCPOption.StaticRoutesWin:
if (replyOptions.StaticRoutes != null)
{
optionData = new byte[] { };
foreach (var route in replyOptions.StaticRoutes)
{
var routeData = route.BuildRouteData();
Array.Resize(ref optionData, optionData.Length + routeData.Length);
Array.Copy(routeData, 0, optionData, optionData.Length - routeData.Length, routeData.Length);
}
}
break;
default:
replyOptions.OtherRequestedOptions.TryGetValue(i, out optionData);
break;
}
if (optionData != null)
{
CreateOptionElement(ref resultOptions, i, optionData);
}
}
}
if (GetMsgType() != DHCPMsgType.DHCPINFORM)
{
// Lease time
if (replyOptions != null)
{
var leaseTime = new byte[4];
leaseTime[3] = (byte)(replyOptions.IPAddressLeaseTime);
leaseTime[2] = (byte)(replyOptions.IPAddressLeaseTime >> 8);
leaseTime[1] = (byte)(replyOptions.IPAddressLeaseTime >> 16);
leaseTime[0] = (byte)(replyOptions.IPAddressLeaseTime >> 24);
CreateOptionElement(ref resultOptions, DHCPOption.IPAddressLeaseTime, leaseTime);
leaseTime[3] = (byte)(replyOptions.RenewalTimeValue_T1);
leaseTime[2] = (byte)(replyOptions.RenewalTimeValue_T1 >> 8);
leaseTime[1] = (byte)(replyOptions.RenewalTimeValue_T1 >> 16);
leaseTime[0] = (byte)(replyOptions.RenewalTimeValue_T1 >> 24);
CreateOptionElement(ref resultOptions, DHCPOption.RenewalTimeValue_T1, leaseTime);
leaseTime[3] = (byte)(replyOptions.RebindingTimeValue_T2);
leaseTime[2] = (byte)(replyOptions.RebindingTimeValue_T2 >> 8);
leaseTime[1] = (byte)(replyOptions.RebindingTimeValue_T2 >> 16);
leaseTime[0] = (byte)(replyOptions.RebindingTimeValue_T2 >> 24);
CreateOptionElement(ref resultOptions, DHCPOption.RebindingTimeValue_T2, leaseTime);
}
}
// Other requested options
if (otherForceOptions != null)
{
foreach (var option in otherForceOptions.Keys)
{
CreateOptionElement(ref resultOptions, option, otherForceOptions[option]);
if (option == DHCPOption.RelayInfo)
{
relayInfo = null;
}
}
}
// Option 82? Send it back!
if (relayInfo != null)
{
CreateOptionElement(ref resultOptions, DHCPOption.RelayInfo, relayInfo);
}
// Create the end option
Array.Resize(ref resultOptions, resultOptions.Length + 1);
Array.Copy(new byte[] { 255 }, 0, resultOptions, resultOptions.Length - 1, 1);
return(resultOptions);
}
