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 Each request specifies a command, a lookup key, and possibly a lookup 38 result. 39 40 <b>get</b> SPACE <i>key</i> NEWLINE 41 Look up data under the specified key. 42 43 <b>put</b> SPACE <i>key</i> SPACE <i>value</i> NEWLINE 44 This request is currently not implemented. 45 46<b>REPLY FORMAT</b> 47 Each reply specifies a status code and text. Replies must be no longer 48 than 4096 characters including the newline terminator. 49 50 <b>500</b> SPACE <i>text</i> NEWLINE 51 In case of a lookup request, the requested data does not exist. 52 In case of an update request, the request was rejected. The 53 text describes the nature of the problem. 54 55 <b>400</b> SPACE <i>text</i> NEWLINE 56 This indicates an error condition. The text describes the nature 57 of the problem. The client should retry the request later. 58 59 <b>200</b> SPACE <i>text</i> NEWLINE 60 The request was successful. In the case of a lookup request, the 61 text contains an encoded version of the requested data. 62 63<b>ENCODING</b> 64 In request and reply parameters, the character %, each non-printing 65 character, and each whitespace character must be replaced by %XX, where 66 XX is the corresponding ASCII hexadecimal character value. The hexadec- 67 imal codes can be specified in any case (upper, lower, mixed). 68 69 The Postfix client always encodes a request. The server may omit the 70 encoding as long as the reply is guaranteed to not contain the % or 71 NEWLINE character. 72 73<b>SECURITY</b> 74 Do not use TCP lookup tables for security critical purposes. The 75 client-server connection is not protected and the server is not authen- 76 ticated. 77 78<b>BUGS</b> 79 Only the lookup method is currently implemented. 80 81 The client does not hang up when the connection is idle for a long 82 time. 83 84<b>SEE ALSO</b> 85 <a href="postmap.1.html">postmap(1)</a>, Postfix lookup table manager 86 <a href="regexp_table.5.html">regexp_table(5)</a>, format of regular expression tables 87 <a href="pcre_table.5.html">pcre_table(5)</a>, format of PCRE tables 88 <a href="cidr_table.5.html">cidr_table(5)</a>, format of CIDR tables 89 90<b>README FILES</b> 91 <a href="DATABASE_README.html">DATABASE_README</a>, Postfix lookup table overview 92 93<b>LICENSE</b> 94 The Secure Mailer license must be distributed with this software. 95 96<b>AUTHOR(S)</b> 97 Wietse Venema 98 IBM T.J. Watson Research 99 P.O. Box 704 100 Yorktown Heights, NY 10598, USA 101 102 Wietse Venema 103 Google, Inc. 104 111 8th Avenue 105 New York, NY 10011, USA 106 107 TCP_TABLE(5) 108</pre> </body> </html> 109