opensmtpd-filter-reportlogger

OpenSMTPD filter which logs all report output to a file.

Setup

1. Copy filter-reportlogger.sh to the smtpd(8) filter directory:

   install -oroot -gbin -m0755 filter-reportlogger.sh /usr/local/libexec/smtpd/filter-reportlogger
   

2. Activate the filter in smtpd.conf(5):

   filter reportlogger proc-exec "filter-reportlogger"
   
   listen on egress filter "reportlogger"
   

Overview

opensmtpd-filter-reportlogger is an experimental filter for OpenSMTPD that registers to receive all report events from smtpd(8) and logs them to an output file.

Currently:

• The filter is implemented as a (KSH) shell program.
• The filter registers to receive several events in the smtp-in subsystem.
• The output file may be specified as either:
  • A user-specified file path (the typical use case).
  • A temporary file (typically written under /tmp). This is useful for testing.
• Debug output is generated and logged to stdout, resulting in smtpd(8) logging that output in the maillog. This output is configurable and includes the following:
  • A startup notice, including the path to the output file.
  • Error output.
  • Debug output, including a copy of every event received by the filter, if debug logging is enabled.
  • A report on shutdown of the program or input termination.

Python (WIP)

A work in progress Python implementation of the filter is also available (filter-reportlogger.py). This implementation doesn't currently appear to complete filter registration correctly and doesn't log any events to the output file.