Why this patch

This patch sets QMAILPPID to the PID of your qmail-qfilter(1) filter’s grandparent (in other words, the process that called qmail-qfilter). If you’re writing custom filters that you’d like to correlate with qmail-smtpd or ofmipd sessions, this patch may be useful to you.

Without this patch

Find some other way to correlate invocations of your filter with qmail-smtpd or ofmipd sessions.

With this patch

In your filter, log the value of QMAILPPID. In the logs, observe the PID, then search for other instances of it.

Get this patch

Download and apply qmail-qfilter-2.1-grandparent-20171026.patch.

(Generated with git diff 2.1 qmail-qfilter-2.1-grandparent-20171026.)

(Merged upstream as pull request #2.)

Improve this patch

If you see a simpler way to do it, I’d love to know.