I have a web service that is running on IIS (6 or 7, doesn't matter) and I would like to know the port that the caller has sent their request/invocation from.
So if a client makes a call on my web service, how do I find out from the server side what the port number is they made the call from?
Is that something that even gets passed at even the lowest level? Just to be clear I'm not looking for the port for callback purposes. It's for logging only.
If you service is on WCF, then:
OperationContext context = OperationContext.Current;
MessageProperties messageProperties = context.IncomingMessageProperties;
var endpointProperty = messageProperties[RemoteEndpointMessageProperty.Name]
as RemoteEndpointMessageProperty;
if (endpointProperty != null)
{
string sRemoteAddress = endpointProperty.Address;
int nRemotePort = endpointProperty.Port;
}
TCP sockets do have the concept of sender port number but it doesn't have much use in application level protocols. That said, considering the last paragraph of the OP, I think you're looking for some way to call back the client. The ports I said previously cannot be used for that. Asynchronous requests are identical to synchronous ones running on a separate thread, nothing special about them.
You should be able to find it as "REMOTE_PORT" in the server variables of the Server object.
However, this port should pretty much always be random, and is only active for the Request/Response pair the client is making. It should be can't be used for asynchronous call backs. Even your webservice when calling to someother service will use a random port number to initiate the request from. The only static port in the communication is the receiving port at the server end of the TCP connection.
Some Network Address Translation-type devices will hide the actual "sending" port number from you. You would then have access to a useless IP address and a useless port number.