term% ls -F
term% cat index.txt
RATFS(4)                   Kernel Interfaces Manual                   RATFS(4)

       ratfs  - mail address ratification file system

       ratfs [ -d ] [ -c configuration ] [ -f classification ] [ -m mountpoint

       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.

              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 suf‐
       ficient to open the file whose name is the IP address.  For example, if
       trusted contains only the file, an attempt to  open  the
       file will succeed while opening will fail.  To de‐
       termine 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 con‐
       figuration (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,  repre‐
       sent     the     contents     of     the     classification    (default
       /mail/lib/smtpd.conf.ext).  Each contains two directories; ip  and  ac‐
       count.  The ip directory has the same open semantics as the trusted di‐
       rectory, 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 un‐
       der allow, block, delay, deny, and dial.  A configuration file entry of
       the form:
       corresponds to the file dial/ip/  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


       mail(1) smtpd(6) scanmail(8)