How can server implementation stub determine the IP address of a client

[srl100]

As detailed in issue #679, in a vsomeip/CommonAPI stub implementation, how can the server determine the IP address of the client that triggers a call to a method?

[Man777]

Did you already got running between 2 different clients, so that you can observe with wireshark the trace between them ? Project with fidl and generated with cgen and build etc.

[srl100]

Comments added after issue #679 was closed appear to be relevant to this issue.

How are other people determining the peer address for a service accessed over UDP ?

[duartenfonseca]

Hi @srl100 , as it was mentioned here #679 the method getHostAddress() would only work with internal TCP connection (applications on the same device). This does not seem to be what you are hoping to achieve. CommonAPI is supposed to work in a abstraction layer above network communication, in the sense that it does not have interfaces for dealing with it.

CommonAPI C++ is a C++ framework for interprocess and network communication. The basic objective is not to provide a new mechanism for interprocess or network communication (IPC), but to define a high-level C++ API, which can be used for different mechanisms. The benefit for C++ developers should be that they are relieved from details of proprietary or little-known communication frameworks or protocols.

this quote is from the CommonAPI wiki (https://covesa.github.io/capicxx-core-tools/)

You would have to get the IP from another source

[srl100]

Hi @duartenfonseca , as it stands it seems to me that _client->getHostAddress() is fundamentally flawed - it does not give you the host address of the client - so we need a work around...

If I got rid of CommonAPI C++ and just used vsomeip on its own (which seems to be like a retrograde step) do you think that I would stand a chance at being able to determine the (IP) source of a request? What am I losing in taking this approach?

I can see that feature would be useful for several reasons (e.g. logging, rate limiting) aside from my purpose (implementing a temporary lock of a service to a particular client IP address).

I can see now that another issue I raised, not being able to set the SOME/IP response code, is also related to this abstracting away of the network communication - once we have got past the stub adapter checks of known services and methods and we are in the dispatcher/handler there appears to be no way to pass a response code back to the SOME/IP layer, so services such as VCIC, which use the SOME/IP response code to reject invalid parameters, cannot be implemented using CommonAPI.

[duartenfonseca]

• For CAPI the interface the _client->getHostAddress() will only return the routing HOST address of the local tcp communication. If unix domain sockets are used instead, there will be no address.

• vsomeip-lib also doesn't provide this as an interface.

The design of CommonAPI (and also vsomeip) is to keep away the user from the underlying network. That´s why all the IP addresses, ports, etc are provided by the vsomeip configuration and not by an API. If an application requires this information for whatever reason, these are the wrong libraries to use.

The feature that could be added here on COVESA would be having the possibility to get that information for debugging purposes only