Re: [Discuss-gnuradio] UDP Source Error (on windows)

[Geof Nieboer]

Thanks Andy,

I will submit a change to remove this set_option from the udp source then.

Geof

On Thu, May 19, 2016 at 3:59 PM, Andy Walls <address@hidden> wrote:

>
> OK, I was able to reproduce the issue, and it appears to me to a core
> GNURadio issue not specifically related to the installer
>
>
> udp_source_impl.cc is setting the SO_LINGER option on the UDP socket,
> which at least on Windows, causes a WSAENOPROTOOPT exception, because
> linger doesn't really mean anything for a UDP socket.
>
>
> Perhaps the Linux folks can help here, but I'm guessing that this
> option must be simply ignored on Linux so there is no error for most
> users.  Looking at the man pages doesn't specify any particular
> behavior required.
>
>
> Geof


SO_LINGER gets processed by the Linux kernel generically here:

http://lxr.free-electrons.com/source/net/core/sock.c#L644

with no check against socket type.

The UDP socket handling doesn't use the resulting SOCK_LINGER flag
setting.
http://lxr.free-electrons.com/source/net/ipv4/udp.c
http://lxr.free-electrons.com/source/net/ipv6/udp.c

Only TCP and the Bluetooth SCO protocol in the Linux kernel care about
SO_LINGER.

Regards,
Andy