On Sat, Oct 31, 2020 at 01:57:08AM +0100, Yann Ylavic wrote:
> On Wed, Oct 28, 2020 at 6:40 PM Joe Orton <[email protected]> wrote:
> >
> > On Wed, Oct 21, 2020 at 05:17:01PM +0100, Adam Hill wrote:
> > > On Linux at least, you can see how much unsent data remains by querying
> > > the
> > > SIOCOUTQ ioctl, so the mitigation would be to check to see that ANY data
> > > was draining at all, and if so ( and there's some left ) extend the
> > > lingering close time and repeat. However, this wouldn't be a cross
> > > platform
> > > solution, but it would at least be the "correct" thing to do in terms of
> > > network function. Not sure if there's an equivalent on other systems.
> >
> > Nice writeup, thank you.
>
> +1
>
> > So I kind of wish that
> > something was missed here, but multiple people have come to exactly that
> > conclusion independently.
>
> It may be due to r1802875 where I added RST (SO_LINGER.l_linger = 0)
> after lingering close timeout.
Oh, happy to see I missed that! Thanks Yann.
> Thinking of it now, it's probably not the right thing to do. Simply
> calling apr_socket_close() in abort_socket_nonblocking() would allow
> the system's lingering close after httpd's.
+1
> Adam, can you still observe the same behaviour with the attached
> mpm_event patch applied?
>
>
> Regards;
> Yann.
> Index: server/mpm/event/event.c
> ===================================================================
> --- server/mpm/event/event.c (revision 1881339)
> +++ server/mpm/event/event.c (working copy)
> @@ -526,21 +526,6 @@ static void abort_socket_nonblocking(apr_socket_t
> {
> apr_status_t rv;
> apr_socket_timeout_set(csd, 0);
> -#if defined(SOL_SOCKET) && defined(SO_LINGER)
> - /* This socket is over now, and we don't want to block nor linger
> - * anymore, so reset it. A normal close could still linger in the
> - * system, while RST is fast, nonblocking, and what the peer will
> - * get if it sends us further data anyway.
> - */
> - {
> - apr_os_sock_t osd = -1;
> - struct linger opt;
> - opt.l_onoff = 1;
> - opt.l_linger = 0; /* zero timeout is RST */
> - apr_os_sock_get(&osd, csd);
> - setsockopt(osd, SOL_SOCKET, SO_LINGER, (void *)&opt, sizeof opt);
> - }
> -#endif
> rv = apr_socket_close(csd);
> if (rv != APR_SUCCESS) {
> ap_log_error(APLOG_MARK, APLOG_ERR, rv, ap_server_conf,
> APLOGNO(00468)
