Mbed-os: Socket::open() behaviour with no network connectivity

[tommikas]

Calling Socket::open() before EthernetInterface::connect() results in sys_arch_protect error.
As a NetworkInterface instance is required by sockets (as documented), I wouldn't necessarily expect it to work (although possibly not with that specific error).

But, as long as EthernetInterface::connect() has been called once, even if DHCP fails or connect() is immediately followed by EthernetInterface::disconnect(), I can then open sockets as if I had working network connectivity.

Is this the intended behaviour in each situation?

[0xc0170]

cc @geky

[geky]

Thanks for reporting this. You are right, this error should be reported more consistently (perhaps with NSAPI_ERROR_PARAMETER). Opening sockets on a disconnect interface should fail as well.

There is also the situation in which a socket is left open through a network disconnect call. I propose we leave this as undefined behaviour due to the complexity in enforcing a consistent error (the EthernetInterface may have been freed at that point).

[tommikas]

Sounds good to me.

[tommikas]

http://jira.arm.com/browse/IOTSFW-2862

[ciarmcom]

ARM Internal Ref: IOTMORF-444

[geky]

This should be fixed on https://github.com/ARMmbed/mbed-os/pull/2561, let me know if there's still and issue

[sg-]

@tommikas Is this resolved?

[tommikas]

Yep. Just been waiting for the changes to land on master. Closing now.