//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);
}
public static DhcpV4Message HandleMessage(IPAddress localAddress, DhcpV4Message dhcpMessage)
{
DhcpV4Message replyMessage = null;
if (dhcpMessage.GetOp() == DhcpConstants.V4_OP_REQUEST)
{
IPAddress linkAddress = null;
if (dhcpMessage.GetGiAddr().Equals(DhcpConstants.ZEROADDR_V4))
{
linkAddress = localAddress;
//log.Info("Handling client request on local client link address: " +
// linkAddress.ToString());
}
else
{
linkAddress = dhcpMessage.GetGiAddr();
log.Info("Handling client request on remote client link address: " +
linkAddress.ToString());
}
DhcpV4MsgTypeOption msgTypeOption = (DhcpV4MsgTypeOption)
dhcpMessage.GetDhcpOption(DhcpConstants.V4OPTION_MESSAGE_TYPE);
if (msgTypeOption != null)
{
short msgType = msgTypeOption.GetUnsignedByte();
DhcpV4MessageProcessor processor = null;
switch (msgType)
{
case DhcpConstants.V4MESSAGE_TYPE_DISCOVER:
processor = new DhcpV4DiscoverProcessor(dhcpMessage, linkAddress);
break;
case DhcpConstants.V4MESSAGE_TYPE_REQUEST:
processor = new DhcpV4RequestProcessor(dhcpMessage, linkAddress);
break;
case DhcpConstants.V4MESSAGE_TYPE_DECLINE:
processor = new DhcpV4DeclineProcessor(dhcpMessage, linkAddress);
break;
case DhcpConstants.V4MESSAGE_TYPE_RELEASE:
processor = new DhcpV4ReleaseProcessor(dhcpMessage, linkAddress);
break;
case DhcpConstants.V4MESSAGE_TYPE_INFORM:
processor = new DhcpV4InformProcessor(dhcpMessage, linkAddress);
break;
default:
log.Error("Unknown message type.");
break;
}
if (processor != null)
{
return(processor.ProcessMessage(localAddress));
}
else
{
log.Error("No processor found for message type: " + msgType);
}
}
else
{
log.Error("No message type option found in request.");
}
return(null);
}
else
{
log.Error("Unsupported op code: " + dhcpMessage.GetOp());
}
return(replyMessage);
}
