RATFS(4) RATFS(4)
NAME
ratfs - mail address ratification file system
SYNOPSIS
ratfs [ -d ] [ -c configuration ] [ -f classification ] [ -m
mountpoint ]
DESCRIPTION
Ratfs starts a process that mounts itself (see bind(2)) on
mountpoint (default /mail/ratify). Ratfs is a persistent
representation of the local network configuration and spam
blocking list. Without it each instance of smtpd(6) would
need to reread and parse a multimegabyte list of addresses
and accounts.
Ratfs serves a control file, ctl, and several top level
directories: trusted, deny, dial, block, delay, and allow.
The control file is write only and accepts three possible
commands:
reload rereads classification and configuration
debug file creates file and sends debugging output to it.
nodebug closes the debug file and turns off debugging
The directory trusted serves a file for each IP range from
which all mail is trusted. The names of the files are CIDR
blocks; an IP address or an IP address followed by #n, where
n is the number of bits to match. To check if any IP
address falls in a trusted range, it is sufficient to open
the file whose name is the IP address. For example, if
trusted contains only the file 135.104.0.0#16, an attempt to
open the file 135.104.9.1 will succeed while opening
10.1.1.1 will fail. To determine the particular range
matched, dirfstat (see stat (2)) the open file and the name
field will be the matching CIDR range.
The trusted ranges come both from the ournet entries in the
file configuration (default /mail/lib/blocked) and from cre-
ates, typically done by imap4d (see ipserv(8)) and pop3 (see
mail(1)) whenever they are used to read someone's mail.
The remaining directories, allow, block, delay, deny, and
dial, represent the contents of the classification (default
/mail/lib/smtpd.conf.ext). Each contains two directories;
ip and account. The ip directory has the same open seman-
tics as the trusted directory, i.e., to check if an IP
address falls in that category, try to open a file whose
name is the IP address. The account directory is similar
but is used for matching strings. Each file in the
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RATFS(4) RATFS(4)
directory represents a regular expression. To see if one of
the strings matches one of the regular expressions, try to
open the file whose name is the string. If it succeeds,
then there is a regular expression that matches. To deter-
mine the regular expression, fstat the open file. The name
field will be the regular expression.
There is a direct mapping from entries in classification and
files under allow, block, delay, deny, and dial. A configu-
ration file entry of the form:
dial 135.104.9.0/24
corresponds to the file dial/ip/135.104.9.0#24. An entry of
the form
*block .*!gre
corresponds to the file block/account/.*!gre.
Both the configuration file and control file formats are
described in smtpd(6).
SOURCE
/sys/src/cmd/ratfs
SEE ALSO
mail(1) smtpd(6) scanmail(8)
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