_nxe_tcp_socket_receive_notify invalid input pointer check breaks documented functionality.

[timp-exi]

https://github.com/azure-rtos/netxduo/blob/846932ee7b379edee9f87627f4d23cb995da4cde/common/src/nxe_tcp_socket_receive_notify.c#L92-L96

As described in the NetX documentation for nx_tcp_socket_receive_notify:

"This service configures the receive notify function pointer with the callback function specified by the application. This callback function is then called whenever one or more packets are received on the socket. If a NX_NULL pointer is supplied, the notify function is disabled."

With the code as it stands, if you run without defining the macro "NX_DISABLE_ERROR_CHECKING" then the error checking function _nxe_tcp_socket_receive_notify will break the documented functionality. Effectively at present you cannot disable the socket receive notify callback if error checking is enabled!

The lines 92 - 96 from _nxe_tcp_socket_receive_notify.c should be removed. (Note in the NetX repo the code is correct for this function. Seems to only be an issue in NetxDuo).

[TiejunMS]

@timp-exi, thanks for reaching out! This function is designed to set callback function but not clear it. So NX_NULL is not allowed. We will keep as it is now. You are free to modify it in your own project.

[timp-exi]

Hi, thanks for your quick response but with all due respect in this case you are mistaken.

If you check the documentation for NetX Duo:

https://learn.microsoft.com/en-us/azure/rtos/netx-duo/chapter4#nx_tcp_socket_receive_notify

It specifically states that the nx_tcp_socket_receive_notify function is used both to set and clear the callback function:

"This service configures the receive notify function pointer with the callback function specified by the application. This callback function is then called whenever one or more packets are received on the socket. If a NX_NULL pointer is supplied, the notify function is disabled."

It makes no sense that the error checking wrapper to this function (nxe_tcp_socket_receive_notify) blocks this functionality. It makes even less sense knowing that this behaviour also contradicts the current NetX implementation ( https://github.com/azure-rtos/netx/blob/master/common/src/nxe_tcp_socket_receive_notify.c ).

So either:

• The documentation is wrong, in which case the NX_NULL pointer check should be moved from nxe_tcp_socket_receive_notify to the nx_tcp_socket_receive_notify function and the documentation should be updated to reflect that).

or

• The documentation is correct, and the nxe_tcp_socket_receive_notify function should be changed to respect the documented functionality of the nx_tcp_socket_receive_notify function (as it does in the NetX branch) instead of the implementation as it currently stands, which breaks the documented functionality.

I would kindly ask that you please take the time to review this again and reconsider your decision.

[TiejunMS]

Good catch! We will honor what user guide describes and remove this check in _nxe_xxx function. Many thanks!

[timp-exi]

That's great, thanks :)

[TiejunMS]

Fixed by commit https://github.com/azure-rtos/netxduo/commit/2973652d801e92615caa285ad9ee13db19a26cb9