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 creates, 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 semantics 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 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 determine 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 configuration 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)