Re: [RFC PATCH v2 0/2] vsock: handle writes to shutdowned socket

From: Arseniy Krasnov
Date: Thu Aug 31 2023 - 13:10:43 EST




On 31.08.2023 18:23, Stefano Garzarella wrote:
> Hi Arseniy,
>
> On Sat, Aug 26, 2023 at 08:58:58PM +0300, Arseniy Krasnov wrote:
>> Hello,
>>
>> this small patchset adds POSIX compliant behaviour on writes to the
>> socket which was shutdowned with 'shutdown()' (both sides - local with
>> SHUT_WR flag, peer - with SHUT_RD flag). According POSIX we must send
>> SIGPIPE in such cases (but SIGPIPE is not send when MSG_NOSIGNAL is set).
>>
>> First patch is implemented in the same way as net/ipv4/tcp.c:tcp_sendmsg_locked().
>> It uses 'sk_stream_error()' function which handles EPIPE error. Another
>> way is to use code from net/unix/af_unix.c:unix_stream_sendmsg() where
>> same logic from 'sk_stream_error()' is implemented "from scratch", but
>> it doesn't check 'sk_err' field. I think error from this field has more
>> priority to be returned from syscall. So I guess it is better to reuse
>> currently implemented 'sk_stream_error()' function.
>>
>> Test is also added.
>>
>> Head for this patchset is:
>> https://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next.git/commit/?id=b38460bc463c54e0c15ff3b37e81f7e2059bb9bb
>>
>> Link to v1:
>> https://lore.kernel.org/netdev/20230801141727.481156-1-AVKrasnov@xxxxxxxxxxxxxx/
>>
>> Changelog:
>> v1 -> v2:
>> * 0001 stills the same - SIGPIPE is sent only for SOCK_STREAM as discussed in v1
>>   with Stefano Garzarella <sgarzare@xxxxxxxxxx>.
>> * 0002 - use 'sig_atomic_t' instead of 'bool' for flag variables updated from
>>   signal handler.
>>
>> Arseniy Krasnov (2):
>>  vsock: send SIGPIPE on write to shutdowned socket
>>  test/vsock: shutdowned socket test
>
> Thanks for this series, I fully reviewed it, LGTM!
>
> Please send it targeting net-next when it reopens.

Hi Stefano,

Ok and thanks for review!

Thanks, Arseniy

>
> Stefano
>