//Process the client request. Find appropriate configuration based on any
//criteria in the request message that can be matched against the server's
//configuration, then formulate a response message containing the options
//to be sent to the client.
//@return a Reply DhcpMessage
public DhcpV4Message ProcessMessage(IPAddress localAddress)
{
Monitor.Enter(_lock);
try
{
//設定ServerId為管理IP
_dhcpV4ServerIdOption.SetIpAddress(localAddress.ToString());
if (!PreProcess())
{
return(null);
}
// build a reply message using the local and remote sockets from the request
_replyMsg = new DhcpV4Message(_requestMsg.GetLocalAddress(), _requestMsg.GetRemoteAddress());
_replyMsg.SetOp(DhcpConstants.V4_OP_REPLY);
// copy fields from request to reply
_replyMsg.SetHtype(_requestMsg.GetHtype());
_replyMsg.SetHlen(_requestMsg.GetHlen());
_replyMsg.SetTransactionId(_requestMsg.GetTransactionId());
_replyMsg.SetFlags(_requestMsg.GetFlags());
_replyMsg.SetGiAddr(_requestMsg.GetGiAddr());
_replyMsg.SetChAddr(_requestMsg.GetChAddr());
// MUST put Server Identifier in REPLY message
_replyMsg.PutDhcpOption(_dhcpV4ServerIdOption);
if (!Process())
{
log.Warn("Message dropped by processor");
return(null);
}
}
catch (Exception ex)
{
log.WarnFormat("BaseDhcpV4Processor ProcessMessage Faile. exMessage:{0} exStackTrace:{1}", ex.Message, ex.StackTrace);
return(null);
}
finally
{
if (!PostProcess())
{
log.Warn("Message dropped by postProcess");
_replyMsg = null;
}
Monitor.Exit(_lock);
}
return(_replyMsg);
}
private DhcpV4Message BuildReleaseMessage(DhcpV4Message ack)
{
DhcpV4Message msg = new DhcpV4Message(null, new IPEndPoint(serverAddr, serverPort));
msg.SetOp((short)DhcpConstants.V4_OP_REQUEST);
msg.SetTransactionId(ack.GetTransactionId());
msg.SetHtype((short)1); // ethernet
msg.SetHlen((byte)6);
msg.SetChAddr(ack.GetChAddr());
msg.SetGiAddr(clientAddr); // look like a relay to the DHCP server
msg.SetCiAddr(ack.GetYiAddr());
DhcpV4MsgTypeOption msgTypeOption = new DhcpV4MsgTypeOption();
msgTypeOption.SetUnsignedByte((short)DhcpConstants.V4MESSAGE_TYPE_RELEASE);
msg.PutDhcpOption(msgTypeOption);
return(msg);
}
private DhcpV4Message BuildRequestMessage(DhcpV4Message offer)
{
DhcpV4Message msg = new DhcpV4Message(IPAddress.Parse("0.0.0.0"), new IPEndPoint(serverAddr, serverPort));
msg.SetOp((short)DhcpConstants.V4_OP_REQUEST);
msg.SetTransactionId(offer.GetTransactionId());
msg.SetHtype((short)1); // ethernet
msg.SetHlen((byte)6);
msg.SetChAddr(offer.GetChAddr());
msg.SetGiAddr(clientAddr); // look like a relay to the DHCP server
DhcpV4MsgTypeOption msgTypeOption = new DhcpV4MsgTypeOption();
msgTypeOption.SetUnsignedByte((short)DhcpConstants.V4MESSAGE_TYPE_REQUEST);
msg.PutDhcpOption(msgTypeOption);
DhcpV4RequestedIpAddressOption reqIpOption = new DhcpV4RequestedIpAddressOption();
reqIpOption.SetIpAddress(offer.GetYiAddr().ToString());
msg.PutDhcpOption(reqIpOption);
return(msg);
}
