# TCP_TABLE(5)                                         TCP_TABLE(5)
# 
# NAME
#        tcp_table - Postfix client/server table lookup protocol
# 
# SYNOPSIS
#        postmap -q "string" tcp:host:port
# 
#        postmap -q - tcp:host:port <inputfile
# 
# DESCRIPTION
#        The  Postfix  mail system uses optional tables for address
#        rewriting or mail routing. These tables are usually in dbm
#        or db format. Alternatively, table lookups can be directed
#        to a TCP server.
# 
#        To find out what types of lookup tables your Postfix  sys-
#        tem supports use the postconf -m command.
# 
#        To   test  lookup  tables,  use  the  postmap  command  as
#        described in the SYNOPSIS above.
# 
# PROTOCOL DESCRIPTION
#        The TCP map class implements a very simple  protocol:  the
#        client  sends  a  request, and the server sends one reply.
#        Requests and replies are sent as one line of  ASCII  text,
#        terminated  by  the  ASCII  newline character. Request and
#        reply parameters (see below) are separated by  whitespace.
# 
# REQUEST FORMAT
#        Each request specifies a command, a lookup key, and possi-
#        bly a lookup result.
# 
#        get SPACE key NEWLINE
#               Look up data under the specified key.
# 
#        put SPACE key SPACE value NEWLINE
#               This request is currently not implemented.
# 
# REPLY FORMAT
#        Each reply specifies a status code and text. Replies  must
#        be  no  longer  than 4096 characters including the newline
#        terminator.
# 
#        500 SPACE text NEWLINE
#               In case of a lookup  request,  the  requested  data
#               does  not exist.  In case of an update request, the
#               request  was  rejected.   The  text  describes  the
#               nature of the problem.
# 
#        400 SPACE text NEWLINE
#               This   indicates   an  error  condition.  The  text
#               describes the nature of  the  problem.  The  client
#               should retry the request later.
# 
#        200 SPACE text NEWLINE
#               The request was successful. In the case of a lookup
#               request, the text contains an  encoded  version  of
#               the requested data.
# 
# ENCODING
#        In  request  and  reply  parameters, the character %, each
#        non-printing character, and each whitespace character must
#        be  replaced  by  %XX, where XX is the corresponding ASCII
#        hexadecimal character value. The hexadecimal codes can  be
#        specified in any case (upper, lower, mixed).
# 
#        The  Postfix  client always encodes a request.  The server
#        may omit the encoding as long as the reply  is  guaranteed
#        to not contain the % or NEWLINE character.
# 
# SECURITY
#        Do  not  use  TCP lookup tables for security critical pur-
#        poses.  The client-server connection is not protected  and
#        the server is not authenticated.
# 
# SEE ALSO
#        regexp_table(5) format of regular expression tables
#        pcre_table(5) format of PCRE tables
#        cidr_table(5) format of CIDR tables
# 
# BUGS
#        Only the lookup method is currently implemented.
# 
#        The  client  does  not hang up when the connection is idle
#        for a long time.
# 
# LICENSE
#        The Secure Mailer license must be  distributed  with  this
#        software.
# 
# AUTHOR(S)
#        Wietse Venema
#        IBM T.J. Watson Research
#        P.O. Box 704
#        Yorktown Heights, NY 10598, USA
# 
#                                                      TCP_TABLE(5)
