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-<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
-<html>
-<!-- SECTION: Specifications -->
-<head>
- <title>CUPS Browse Protocol</title>
- <meta name='keywords' content='Programming'>
- <LINK REL="STYLESHEET" TYPE="text/css" HREF="../cups-printable.css">
-</head>
-<body>
-<!--
- "$Id$"
-
- CUPS Browse Protocol specification for CUPS.
-
- Copyright 2008-2011 by Apple Inc.
- Copyright 1997-2005 by Easy Software Products.
-
- These coded instructions, statements, and computer programs are the
- property of Apple Inc. and are protected by Federal copyright
- law. Distribution and use rights are outlined in the file "LICENSE.txt"
- which should have been included with this file. If this file is
- file is missing or damaged, see the license at "http://www.cups.org/".
--->
-
-<BLOCKQUOTE><B>Note:</B>
-
-<P>The CUPS Browse Protocol is deprecated and will no longer be used in a future release of CUPS.</P>
-
-</BLOCKQUOTE>
-
-<H1 CLASS="title">CUPS Browse Protocol</H1>
-
-<h2><a name='INTRO'>Introduction</a></h2>
-
-<p>This specification describes the CUPS browsing protocol which is used for
-printer sharing. The protocol is a UDP/IP-based broadcast service that
-operates on IP service port 631 by default. Each broadcast packet describes
-a single printer or class being shared.</p>
-
-<p>For simple networks with a single subnet, a CUPS system sharing a printer
-(the <em>server</em>) will periodically broadcast that printer's availability
-and status information to the subnet. Every other CUPS system on the subnet
-(the <em>clients</em>) will receive the broadcast and make that printer
-available to local users. If a client stops receiving broadcasts from the
-server, or if the server sends a special "deleted" broadcast message, the
-client will remove its copy of the printer.</p>
-
-<p>For larger networks with multiple subnets, a relay configuration can be used
-where one or more client systems poll the server and then broadcast the
-availability and status information for the server's shared printers to the
-clients' local subnets.</p>
-
-<p>A key feature of CUPS printer sharing is support for <em>implicit
-classes</em>, which are automatically-created classes for printers that are
-shared by multiple servers. These implicit classes provide automatic load
-balancing and fail-safe printing functionality transparently to the user.</p>
-
-
-<h2><a name='SECURITY'>Security Considerations</a></h2>
-
-<p>Like most discovery protocols, CUPS browse packets are not encrypted or
-signed, so it is possible for malicious systems on a network to advertise
-or remove printers on that network to cause denial of service or information
-disclosure. In order to combat this, CUPS logs incoming browse packets and
-provides access controls to limit browse packet reception to known hosts.</p>
-
-
-<h2><a name='FORMAT'>Browse Packet Format</a></h2>
-
-<p>Each broadcast packet is an ASCII text string of up to 1450 bytes ending
-with a line feed (0x0a). The general format is:</p>
-
-<p class='summary'>
-printer-type printer-state printer-uri "printer-location" "printer-info"
-"printer-make-and-model" name=value name2=value2 ...
-</p>
-
-<p>Each of the fields contains the value of the corresponding IPP attribute.
-The trailing "name=value" information is used to convey default job template
-attribute values (job-sheets-default, media-default, etc.), authentication
-requirements (auth-info-required), and additional IPP URI options that are
-requested by the server (ipp-options).</p>
-
-<h3>ABNF Definition</h3>
-
-<p>The following ABNF definition [RFC4234, RFC3986] defines the format of each
-browse packet:</p>
-
-<pre class='command'>
-PACKET = TYPE WSP STATE WSP URI WSP LOCATION WSP INFO WSP
- MAKE-AND-MODEL WSP *[ WSP ATTR-NAME "=" ATTR-VALUE ] LF
-
-TYPE = 1*HEXDIG
-
-STATE = "3" / "4" / "5"
-
-URI = "ipp://" ( 1*NAMECHAR / IP-literal / IPv4address )
- [ ":" 1*DIGIT ] ( "/printers/" / "/classes/" ) 1*NAMECHAR
-NAMECHAR = %x21.22.24.26-2E.30-7E / %x25 HEXDIG HEXDIG
-IP-literal = See RFC 3986
-IPv4address = See RFC 3986
-
-LOCATION = QUOTED-STRING
-INFO = QUOTED-STRING
-MAKE-AND-MODEL = QUOTED-STRING
-
-ATTR-NAME = 1*( ALPHA / DIGIT / "-" / "." )
-ATTR-VALUE = QUOTED-STRING / 1*UNQUOTE-CHAR
-
-QUOTED-STRING = DQUOTE *QUOTED-CHAR DQUOTE
-QUOTED-CHAR = %x20.21.23-5B.5D-7E / UTF8-CHAR / %x5C %x5C / %x5C %x22
-UNQUOTE-CHAR = %x21.23-26.28-5B.5D-7E / UTF8-CHAR
-UTF8-CHAR = %xC0.DF %x80.BF / %xE0.EF %x80.BF %x80.BF /
- %xF0.F7 %x80.BF %x80.BF %x80.BF
-</pre>
-
-</body>
-</html>
projects / thirdparty / cups.git / commitdiff
