Hello,
I want to check inbound SMTP connections
to verify that the HELO/EHLO name matches
the associated rDNS entry.
MY FILTER
filter "HELO_FQDN" phase ehlo match !helo rdns disconnect "NNN:msg."
REPORTED ERROR
doas smtpd -n
/etc/mail/smtpd.conf:191: syntax error
IDEA ORIGINATION (smtpd.conf man page, as follows)
match
[!] helo helo-name | <helo-name>
Specify that session's HELO/EHLO should match the string \
or list table helo-name.
ALSO TRIED
filter "HELO_FQDN" phase ehlo match !helo {rdns} disconnect "NNN:msg."
filter "HELO_FQDN" phase ehlo match !helo fcrdns disconnect "NNN:msg."
filter "HELO_FQDN" phase ehlo match !helo {fcrdns} disconnect "NNN:msg."
with identical errors to that above.
According to man 5 smtpd.conf
...
helo <table> helo name is in table
...
What follows helo must be a table with allowed!disallowed hostnames.
rdns after helo is not a function or comparison.
SUMMARY
smtpd has the rDNS name associated with the calling SMTP session;
how to use that name in a filter?
Someone has to program a custom filter with smtpd-filters API.
man 7 smtpd-filters
