1<!doctype html public "-//W3C//DTD HTML 4.01 Transitional//EN" 2 "http://www.w3.org/TR/html4/loose.dtd"> 3<html> <head> 4<meta http-equiv="Content-Type" content="text/html; charset=us-ascii"> 5<title> Postfix manual - tcp_table(5) </title> 6</head> <body> <pre> 7TCP_TABLE(5) TCP_TABLE(5) 8 9<b>NAME</b> 10 tcp_table - Postfix client/server table lookup protocol 11 12<b>SYNOPSIS</b> 13 <b>postmap -q "</b><i>string</i><b>" <a href="tcp_table.5.html">tcp</a>:</b><i>host:port</i> 14 15 <b>postmap -q - <a href="tcp_table.5.html">tcp</a>:</b><i>host:port</i> <<i>inputfile</i> 16 17<b>DESCRIPTION</b> 18 The Postfix mail system uses optional tables for address rewriting or 19 mail routing. These tables are usually in <b>dbm</b> or <b>db</b> format. Alterna- 20 tively, table lookups can be directed to a TCP server. 21 22 To find out what types of lookup tables your Postfix system supports 23 use the "<b>postconf -m</b>" command. 24 25 To test lookup tables, use the "<b>postmap -q</b>" command as described in the 26 SYNOPSIS above. 27 28<b>PROTOCOL DESCRIPTION</b> 29 The TCP map class implements a very simple protocol: the client sends a 30 request, and the server sends one reply. Requests and replies are sent 31 as one line of ASCII text, terminated by the ASCII newline character. 32 Request and reply parameters (see below) are separated by whitespace. 33 34 Send and receive operations must complete in 100 seconds. 35 36<b>REQUEST FORMAT</b> 37 The tcp_table protocol supports only the lookup request. The request 38 has the following form: 39 40 <b>get</b> SPACE <i>key</i> NEWLINE 41 Look up data under the specified key. 42 43 Postfix will not generate partial search keys such as domain names 44 without one or more subdomains, network addresses without one or more 45 least-significant octets, or email addresses without the localpart, 46 address extension or domain portion. This behavior is also found with 47 <a href="cidr_table.5.html">cidr</a>:, <a href="pcre_table.5.html">pcre</a>:, and <a href="regexp_table.5.html">regexp</a>: tables. 48 49<b>REPLY FORMAT</b> 50 Each reply specifies a status code and text. Replies must be no longer 51 than 4096 characters including the newline terminator. 52 53 <b>500</b> SPACE <i>text</i> NEWLINE 54 In case of a lookup request, the requested data does not exist. 55 The text describes the nature of the problem. 56 57 <b>400</b> SPACE <i>text</i> NEWLINE 58 This indicates an error condition. The text describes the nature 59 of the problem. The client should retry the request later. 60 61 <b>200</b> SPACE <i>text</i> NEWLINE 62 The request was successful. In the case of a lookup request, the 63 text contains an encoded version of the requested data. 64 65<b>ENCODING</b> 66 In request and reply parameters, the character %, each non-printing 67 character, and each whitespace character must be replaced by %XX, where 68 XX is the corresponding ASCII hexadecimal character value. The hexadec- 69 imal codes can be specified in any case (upper, lower, mixed). 70 71 The Postfix client always encodes a request. The server may omit the 72 encoding as long as the reply is guaranteed to not contain the % or 73 NEWLINE character. 74 75<b>SECURITY</b> 76 Do not use TCP lookup tables for security critical purposes. The 77 client-server connection is not protected and the server is not authen- 78 ticated. 79 80<b>BUGS</b> 81 Only the lookup method is currently implemented. 82 83 The client does not hang up when the connection is idle for a long 84 time. 85 86<b>SEE ALSO</b> 87 <a href="postmap.1.html">postmap(1)</a>, Postfix lookup table manager 88 <a href="regexp_table.5.html">regexp_table(5)</a>, format of regular expression tables 89 <a href="pcre_table.5.html">pcre_table(5)</a>, format of PCRE tables 90 <a href="cidr_table.5.html">cidr_table(5)</a>, format of CIDR tables 91 92<b>README FILES</b> 93 <a href="DATABASE_README.html">DATABASE_README</a>, Postfix lookup table overview 94 95<b>LICENSE</b> 96 The Secure Mailer license must be distributed with this software. 97 98<b>AUTHOR(S)</b> 99 Wietse Venema 100 IBM T.J. Watson Research 101 P.O. Box 704 102 Yorktown Heights, NY 10598, USA 103 104 Wietse Venema 105 Google, Inc. 106 111 8th Avenue 107 New York, NY 10011, USA 108 109 TCP_TABLE(5) 110</pre> </body> </html> 111