Re: [PATCH] ip.7: Add not supported by SOCK_STREAM to socket options

From: Alejandro Colomar
Date: Wed Mar 06 2024 - 05:59:35 EST


Hi Oliver,

On Tue, Mar 05, 2024 at 02:31:48PM -0500, Oliver Crumrine wrote:
> Hi Alex,
> I have attached two programs in the form of C source code below. No
> special compilation options required. To change between the three
> different socket options outlined in my patch, there are two options on
> line 16 and 18 with a comment above them explaining how to use the
> fields.
>
> Here's how to use the programs:
> 0. Make sure you have netcat installed.
> 1. Compile the dgram one.
> 2. Run it.
> 3. Run nc localhost 8888 -u (in a seperate terminal window or tab)
> 4. Type whatever into netcat and press enter
> 5. Observe that there is a control message recieved, and there is a byte
> printed, which is the first byte of the data in the control message.

Can't reproduce this. The terminal running nc(1) isn't printing
anything.

alx@debian:~$ which nc
/usr/bin/nc
alx@debian:~$ which nc | xargs realpath
/usr/bin/nc.openbsd
alx@debian:~$ dpkg -S /bin/nc.openbsd
netcat-openbsd: /bin/nc.openbsd

> 6. You may repeat this for the three different socket options.
> 7. Repeat for the stream one, but use nc localhost 8888 (without the -u)
> for #5.
> 8. Observe that there are no control messages recieved with the stream one,
> and byte is 00, which is the initial value of the variable, before it has
> a value assigned when the control messages (of which there are none) are read.
>
> Thanks,
> Oliver

Have a lovely day!
Alex

--
<https://www.alejandro-colomar.es/>
Looking for a remote C programming job at the moment.

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