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eProsima / Micro-XRCE-DDS-Client

Micro XRCE-DDS Client repository. Looking for commercial support? Contact info@eprosima.com
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Not checking return value of setsockopt leads to silent failure when error occurs #324

Closed k7g03z closed 2 years ago

k7g03z commented 2 years ago

In the following line, it is attempted to set the receive timeout by calling the setsockopt with the appropriate parameters

https://github.com/eProsima/Micro-XRCE-DDS-Client/blob/6f4edd25c0984fd30bf3bf84e2d1d33af03f24a1/src/c/profile/discovery/transport/udp_transport_datagram_posix_nopoll.c#L70

When setting up Micro-ROS on a new hardware platform, the executor did not function properly. After lots of debugging, we found out that the platform provider did not set the define in their generated lwipopts.h:

#define LWIP_SO_RCVTIMEO 1

When the define is not set, the LWIP stack does not provide the receive timeout functionality, and setsockopt returns -1.

The following call: https://github.com/eProsima/Micro-XRCE-DDS-Client/blob/6f4edd25c0984fd30bf3bf84e2d1d33af03f24a1/src/c/profile/discovery/transport/udp_transport_datagram_posix_nopoll.c#L72

then waits indefinitely, blocking any further Micro-ROS executor functionality.

Since the above code does not check the error, the user has no idea why the executor runs once and then nothing else happens..

pablogs9 commented 2 years ago

Could you take a look at this PR and provide some feedback: https://github.com/eProsima/Micro-XRCE-DDS-Client/pull/325 ??

Thanks a lot for the report, very useful.

Acuadros95 commented 2 years ago

Closing as https://github.com/eProsima/Micro-XRCE-DDS-Client/pull/325 merged.

Please reopen if needed, thanks for the catch!