Michael Fischer v. Mollard <lists@???> (Di 22 Mär 2016 11:02:13 CET):
>
>
> other PIDs, but same situation:
> # strace -p 18619
> Process 18619 attached
> select(8, [7], NULL, NULL, {17, 252791}) = 0 (Timeout)
> wait4(-1, 0x7ffe6b2aef8c, WNOHANG, NULL) = 0
> select(8, [7], NULL, NULL, {60, 0}) = 0 (Timeout)
> wait4(-1, 0x7ffe6b2aef8c, WNOHANG, NULL) = 0
> select(8, [7], NULL, NULL, {60, 0}) = 0 (Timeout)
> wait4(-1, 0x7ffe6b2aef8c, WNOHANG, NULL) = 0
> select(8, [7], NULL, NULL, {60, 0}^CProcess 18619 detached
> <detached ...>
Looks like the loop in src/deliver.c in function par_wait(), around line
3603. Waiting for any subprocess or (primarily) for the deliver status
from the subprocess.
There doesn't seem to be implemented a global timeout, this is probably
done in the transports/smtp.c…
> with
> exim4 18619 root 0u CHR 1,3 0t0 1034 /dev/null
> exim4 18619 root 1u CHR 1,3 0t0 1034 /dev/null
> exim4 18619 root 2u CHR 1,3 0t0 1034 /dev/null
> exim4 18619 root 3r CHR 1,9 0t0 1039 /dev/urandom
> exim4 18619 root 4uw REG 253,0 134167 1795 /var/spool/exim4/input/1aiHUQ-0004q8-Lq-D
> exim4 18619 root 5w REG 253,0 176 1649 /var/spool/exim4/msglog/1aiHUQ-0004q8-Lq
> exim4 18619 root 6w REG 253,0 0 1827 /var/spool/exim4/input/1aiHUQ-0004q8-Lq-J
> exim4 18619 root 7r FIFO 0,8 0t0 98772157 pipe
>
> and
> # strace -p 18622
> Process 18622 attached
> recvfrom(7, ^CProcess 18622 detached
> <detached ...>
It's not easy to tell who (which function) is calling this recvfrom(). I
suppose, it's inside the TLS connection handling, and hidden from any
"external" timeout catchers.
Is it possible to have a tcpdump watching the connection and then, if
the error re-occurs, to filter out the stream?
I'd like at which stage of conversation it hangs.
> exim4 18622 Debian-exim 7u IPv4 98772160 0t0 TCP XXXX:41992->YYYY:smtp (ESTABLISHED)
> exim4 18622 Debian-exim 8w FIFO 0,8 0t0 98772157 pipe
Unfortunately it's not visible how much they talked to each other
already.
Using an acl condion
condition = <to be forwarded to the internal host>
control = debug/tag=.foo/opts=+all
would help too.
--
Heiko
