From ae9d18bce985de6ff806c167059ffdd554278882 Mon Sep 17 00:00:00 2001 From: Jeremy Harris Date: Mon, 8 Jun 2015 21:48:50 +0100 Subject: Truncate delay when peer closes connection. Bug 348 This is now possible on Linux, at least. --- src/src/acl.c | 40 +++++++++++++++++++++++++++++----------- 1 file changed, 29 insertions(+), 11 deletions(-) (limited to 'src') diff --git a/src/src/acl.c b/src/src/acl.c index e79c87f83..dae310117 100644 --- a/src/src/acl.c +++ b/src/src/acl.c @@ -3480,6 +3480,34 @@ for (; cb != NULL; cb = cb->next) debug_printf("delay skipped in -bh checking mode\n"); } + /* NOTE 1: Remember that we may be + dealing with stdin/stdout here, in addition to TCP/IP connections. + Also, delays may be specified for non-SMTP input, where smtp_out and + smtp_in will be NULL. Whatever is done must work in all cases. + + NOTE 2: The added feature of flushing the output before a delay must + apply only to SMTP input. Hence the test for smtp_out being non-NULL. + */ + + else + { + if (smtp_out != NULL && !disable_delay_flush) + mac_smtp_fflush(); + +#if !defined(NO_POLL_H) && defined (_GNU_SOURCE) + { + struct pollfd p; + nfds_t n = 0; + if (smtp_out) + { + p.fd = fileno(smtp_out); + p.events = POLLRDHUP; + n = 1; + } + if (poll(&p, n, delay*1000) > 0) + HDEBUG(D_acl) debug_printf("delay cancelled by peer close\n"); + } +#else /* It appears to be impossible to detect that a TCP/IP connection has gone away without reading from it. This means that we cannot shorten the delay below if the client goes away, because we cannot discover @@ -3489,20 +3517,10 @@ for (; cb != NULL; cb = cb->next) Exim process is not held up unnecessarily. However, it seems that we can't. The poll() function does not do the right thing, and in any case it is not always available. - - NOTE 1: If ever this state of affairs changes, remember that we may be - dealing with stdin/stdout here, in addition to TCP/IP connections. - Also, delays may be specified for non-SMTP input, where smtp_out and - smtp_in will be NULL. Whatever is done must work in all cases. - - NOTE 2: The added feature of flushing the output before a delay must - apply only to SMTP input. Hence the test for smtp_out being non-NULL. */ - else - { - if (smtp_out != NULL && !disable_delay_flush) mac_smtp_fflush(); while (delay > 0) delay = sleep(delay); +#endif } } } -- cgit v1.2.3