CIDR_TABLE

Section: File Formats (5)
Page Index
 

NAME

cidr_table - format of Postfix CIDR tables  

SYNOPSIS

postmap -q "string" cidr:/etc/postfix/filename

postmap -q - cidr:/etc/postfix/filename <inputfile
 

DESCRIPTION

The Postfix mail system uses optional lookup tables. These tables are usually in dbm or db format. Alternatively, lookup tables can be specified in CIDR (Classless Inter-Domain Routing) form. In this case, each input is compared against a list of patterns. When a match is found, the corresponding result is returned and the search is terminated.

To find out what types of lookup tables your Postfix system supports use the "postconf -m" command.

To test lookup tables, use the "postmap -q" command as described in the SYNOPSIS above.  

TABLE FORMAT



The general form of a Postfix CIDR table is:



pattern     result

When a search string matches the specified pattern, use
the corresponding result value. The pattern must be
in network/prefix or network_address form (see
ADDRESS PATTERN SYNTAX below).

!pattern     result

When a search string does not match the specified pattern,
use the specified result value. The pattern must
be in network/prefix or network_address form (see
ADDRESS PATTERN SYNTAX below).


This feature is available in Postfix 3.2 and later.

if pattern


endif

When a search string matches the specified pattern, match
that search string against the patterns between if and
endif.  The pattern must be in network/prefix or
network_address form (see ADDRESS PATTERN SYNTAX below). The
if..endif can nest.


Note: do not prepend whitespace to text between
if..endif.


This feature is available in Postfix 3.2 and later.

if !pattern


endif

When a search string does not match the specified pattern,
match that search string against the patterns between if and
endif. The pattern must be in network/prefix or
network_address form (see ADDRESS PATTERN SYNTAX below). The
if..endif can nest.


Note: do not prepend whitespace to text between
if..endif.


This feature is available in Postfix 3.2 and later.

blank lines and comments

Empty lines and whitespace-only lines are ignored, as
are lines whose first non-whitespace character is a `#'.

multi-line text

A logical line starts with non-whitespace text. A line that
starts with whitespace continues a logical line.


 

TABLE SEARCH ORDER






Patterns are applied in the order as specified in the table, until a
pattern is found that matches the search string.
 

ADDRESS PATTERN SYNTAX






Postfix CIDR tables are pattern-based. A pattern is either
a network_address which requires an exact match, or a
network_address/prefix_length where the prefix_length
part specifies the length of the network_address prefix
that must be matched (the other bits in the network_address
part must be zero).


An IPv4 network address is a sequence of four decimal octets
separated by ".", and an IPv6 network address is a sequence
of three to eight hexadecimal octet pairs separated by ":"
or "::", where the latter is short-hand for a sequence of
one or more all-zero octet pairs. The pattern 0.0.0.0/0
matches every IPv4 address, and ::/0 matches every IPv6
address.  IPv6 support is available in Postfix 2.2 and
later.


Before comparisons are made, lookup keys and table entries
are converted from string to binary. Therefore, IPv6 patterns
will be matched regardless of leading zeros (a leading zero in
an IPv4 address octet indicates octal notation).


Note: address information may be enclosed inside "[]" but
this form is not required.
 

EXAMPLE SMTPD ACCESS MAP




/etc/postfix/main.cf:
    smtpd_client_restrictions = ... cidr:/etc/postfix/client.cidr ...

/etc/postfix/client.cidr:
    # Rule order matters. Put more specific whitelist entries
    # before more general blacklist entries.
    192.168.1.1             OK
    192.168.0.0/16          REJECT
    2001:db8::1             OK
    2001:db8::/32           REJECT



 

SEE ALSO




postmap(1), Postfix lookup table manager
regexp_table(5), format of regular expression tables
pcre_table(5), format of PCRE tables

 

README FILES






Use "postconf readme_directory" or
"postconf html_directory" to locate this information.


DATABASE_README, Postfix lookup table overview

 

HISTORY




CIDR table support was introduced with Postfix version 2.1.
 

AUTHOR(S)




The CIDR table lookup code was originally written by:
Jozsef Kadlecsik
KFKI Research Institute for Particle and Nuclear Physics
POB. 49
1525 Budapest, Hungary

Adopted and adapted by:
Wietse Venema
IBM T.J. Watson Research
P.O. Box 704
Yorktown Heights, NY 10598, USA

Wietse Venema
Google, Inc.
111 8th Avenue
New York, NY 10011, USA






 
Index




NAME


SYNOPSIS


DESCRIPTION


TABLE FORMAT


TABLE SEARCH ORDER


ADDRESS PATTERN SYNTAX


EXAMPLE SMTPD ACCESS MAP


SEE ALSO


README FILES


HISTORY


AUTHOR(S)