aboutsummaryrefslogtreecommitdiff
path: root/libXdmcp
diff options
context:
space:
mode:
authormarha <marha@users.sourceforge.net>2011-09-16 08:40:57 +0200
committermarha <marha@users.sourceforge.net>2011-09-16 08:40:57 +0200
commit9d911bc1246139019e555f443e934677a067bc0a (patch)
tree2af1428f59f88fbcbe4e0ed27a29ff9f3426210a /libXdmcp
parent4095d7af9f50126361eb7b0aeba6869786f63d5c (diff)
parent18ae1470a8dbcfe369ddf0d7e17e0ea665251ccd (diff)
downloadvcxsrv-9d911bc1246139019e555f443e934677a067bc0a.tar.gz
vcxsrv-9d911bc1246139019e555f443e934677a067bc0a.tar.bz2
vcxsrv-9d911bc1246139019e555f443e934677a067bc0a.zip
Merge remote-tracking branch 'origin/released'
Diffstat (limited to 'libXdmcp')
-rw-r--r--libXdmcp/doc/xdmcp.xml7813
-rw-r--r--libXdmcp/docbook.am112
2 files changed, 3967 insertions, 3958 deletions
diff --git a/libXdmcp/doc/xdmcp.xml b/libXdmcp/doc/xdmcp.xml
index c8797742d..36abb75a9 100644
--- a/libXdmcp/doc/xdmcp.xml
+++ b/libXdmcp/doc/xdmcp.xml
@@ -1,3906 +1,3907 @@
-<?xml version="1.0" encoding="UTF-8" ?>
-<!DOCTYPE book PUBLIC "-//OASIS//DTD DocBook XML V4.3//EN"
- "http://www.oasis-open.org/docbook/xml/4.3/docbookx.dtd" [
-<!--
- variable names used in equation markup in the authentication chapter
- FIXME: Replace with mathml?
- -->
-<!ENTITY variable.D "<emphasis role='italic'>D</emphasis>">
-<!ENTITY variable.N "<emphasis role='italic'>N</emphasis>">
-<!ENTITY variable.T "<emphasis role='italic'>T</emphasis>">
-<!ENTITY variable.Delta "<emphasis role='italic'>&Delta;</emphasis>">
-<!ENTITY variable.alpha "<emphasis role='italic'>&alpha;</emphasis>">
-<!ENTITY variable.beta "<emphasis role='italic'>&beta;</emphasis>">
-<!ENTITY variable.kappa "<emphasis role='italic'>&kappa;</emphasis>">
-<!ENTITY variable.rho "<emphasis role='italic'>&rho;</emphasis>">
-<!ENTITY variable.sigma "<emphasis role='italic'>&sigma;</emphasis>">
-<!ENTITY variable.tau "<emphasis role='italic'>&tau;</emphasis>">
-]>
-
-<book id="xdmcp">
-
-<bookinfo>
- <title>X Display Manager Control Protocol</title>
- <subtitle>X.Org Standard</subtitle>
- <releaseinfo>Version 1.1</releaseinfo>
- <authorgroup>
- <author>
- <firstname>Keith</firstname><surname>Packard</surname>
- <affiliation><orgname>
-X Consortium,
-Laboratory for Computer Science,
-Massachusetts Institute of Technology
- </orgname></affiliation>
- </author>
- </authorgroup>
-
- <copyright><year>1989</year><year>2004</year>
- <holder>The Open Group</holder></copyright>
- <productnumber>X Version 11, Release 6.8</productnumber>
-
-<legalnotice>
-
-
-
-<para>
-Permission is hereby granted, free of charge, to any person obtaining a copy
-of this software and associated documentation files (the "Software"), to deal
-in the Software without restriction, including without limitation the rights
-to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
-copies of the Software, and to permit persons to whom the Software is
-furnished to do so, subject to the following conditions:
-</para>
-<para>
-The above copyright notice and this permission notice shall be included in
-all copies or substantial portions of the Software.
-</para>
-<para>
-THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
-IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
-FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
-OPEN GROUP BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN
-AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
-CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
-</para>
-<para>
-Except as contained in this notice, the name of The Open Group shall not be
-used in advertising or otherwise to promote the sale, use or other dealings
-in this Software without prior written authorization from The Open Group.
-</para>
-
-<para>
-<emphasis remap='I'>X Window System</emphasis> is a trademark of The Open Group.
-</para>
-</legalnotice>
-</bookinfo>
-
-<chapter id="Purpose_and_Goals">
-<title>Purpose and Goals</title>
-<!-- .XS -->
-<!-- (SN Purpose and Goals -->
-<!-- .XE -->
-<para>
-<!-- .LP -->
-The purpose of the X Display Manager Control Protocol (XDMCP)
-is to provide a uniform mechanism for an autonomous
-display to request login service from a remote host.
-By autonomous, we mean
-the display consists of hardware and processes that are independent of any
-particular host where login service is desired. (For example, the server
-cannot simply be started by a
-<function>fork/exec</function>
-sequence on the host.)
-An X terminal (screen, keyboard, mouse, processor, network interface)
-is a prime example of an autonomous display.
-</para>
-
-<para>
-From the point of view of the end user, it is very important to make
-autonomous displays as easy to use as traditional hardwired character
-terminals. Specifically, you can typically just power on a hardwired
-terminal and be greeted with a login prompt. The same should be possible
-with autonomous displays. However, in a network environment with multiple
-hosts, the end user may want to choose which host(s) to connect to. In an
-environment with many displays and many hosts, a site administrator may want
-to associate particular collections of hosts with particular displays. We
-would like to support the following options:
-</para>
-
-<itemizedlist>
- <listitem>
- <para>
-The display has a single, fixed host to which it should connect. It should be
-possible to power on the display and receive a login prompt, without user
-intervention.
- </para>
- </listitem>
- <listitem>
- <para>
-Any one of several hosts on a network or subnetwork may be acceptable
-for accepting login from the display.
-(For example, the user's file systems can be mounted onto
-any such host, providing comparable environments.) It should be possible
-for the display to broadcast to find such hosts and to have the display
-either automatically choose a host or present the possible hosts to the
-user for selection.
- </para>
- </listitem>
- <listitem>
- <para>
-The display has a fixed set of hosts that it can connect to. It should be
-possible for the display to have that set stored in RAM, but it should also be
-possible for a site administrator to be able to maintain host sets for a
-large number of displays using a centralized facility, without having to
-interact (physically or electronically) with each individual display.
-Particular hosts should be allowed to refuse login service, based on
-whatever local criteria are desired.
- </para>
- </listitem>
-</itemizedlist>
-
-<para>
-The control protocol should be designed in such a way that it can be used over
-a reasonable variety of communication transport layers. In fact, it is quite
-desirable if every major network protocol family that supports the standard X
-protocol is also capable of supporting XDMCP, because the end result of XDMCP
-negotiation will be standard X protocol connections to the display.
-However, because the number of displays per host may be large,
-a connection-based protocol appears less desirable
-than a connection-less protocol. For this reason the protocol is designed
-to use datagram services with the display responsible for sequencing and
-retransmission.
-</para>
-<para>
-<!-- .LP -->
-To keep the burden on displays at a minimum (because display cost is not
-a factor that can be ignored), it is desirable that displays not be required
-to maintain permanent state (across power cycles) for the purposes
-of the control protocol,
-and it is desirable to keep required state at a minimum while the
-display is powered on.
-</para>
-<para>
-<!-- .LP -->
-Security is an important consideration and must be an integral part of the
-design. The important security goals in the context of XDMCP are:
-</para>
-<itemizedlist>
- <listitem>
- <para>
-It should be possible for the display to verify that it is communicating
-with a legitimate host login service. Because the user will present
-credentials (for example, password) to this service,
-it is important to avoid spoof attacks.
- </para>
- </listitem>
- <listitem>
- <para>
-It should be possible for the display and the login service to negotiate the
-authorization mechanism to be used for the standard X protocol.
- </para>
- </listitem>
- <listitem>
- <para>
-It should be possible to provide the same level of security in verifying the
-login service as is provided by the negotiated authorization mechanism.
- </para>
- </listitem>
- <listitem>
- <para>
-Because there are no firm standards yet in the area of security,
-XDMCP must be flexible enough to accomodate a variety of security mechanisms.
- </para>
- </listitem>
-</itemizedlist>
-</chapter>
-
-<chapter id="Overview_of_the_Protocol">
-<title>Overview of the Protocol</title>
-<!-- .XS -->
-<!-- (SN Overview of the Protocol -->
-<!-- .XE -->
-<para>
-<!-- .LP -->
-XDMCP is designed to provide authenticated access to display management
-services for remote displays. A new network server, called a \fIDisplay
-Manager\fP, will use XDMCP to communicate with displays to negotiate the
-startup of X sessions. The protocol allows the display to authenticate the
-manager. It also allows most of the configuration information to be
-centralized with the manager and to ease the burden of system administration
-in a large network of displays.
-The essential goal is to provide plug-and-play
-services similar to those provided in the familiar mainframe/terminal world.
-</para>
-<para>
-<!-- .LP -->
-Displays may be turned off by the user at any time. Any existing session
-running on a display that has been turned off must be identifiable. This
-is made possible by requiring a three-way handshake to start a session. If
-the handshake succeeds, any existing session is terminated immediately and a
-new session started. There is the problem (at least with TCP) that
-connections may not be closed when the display is turned off. In most
-environments, the manager should reduce this problem by periodically XSync'ing
-on its own connection, perhaps every five to ten minutes, and terminating the
-session if its own connection ever closes.
-</para>
-<para>
-<!-- .LP -->
-Displays should not be required to retain permanent state for purposes of
-the control protocol. One solution to packets received out of sequence
-would be to use monotonically increasing message identifiers in each message
-to allow both sides to ignore messages that arrive out-of-sequence. For
-this to work, displays would at a minimum have to increment a stable crash
-count each time they are powered on and use that number as part of a
-larger sequence number. But if displays cannot retain permanent state this
-cannot work. Instead, the manager assumes the responsibility for permanent
-state by generating unique numbers that identify a particular session and
-the protocol simply ignores packets that correspond to an invalid session.
-</para>
-<para>
-<!-- .LP -->
-The Manager must not be responsible for packet reception. To prevent the
-Manager from becoming stuck because of a hostile display, no portion of the
-protocol requires the Manager to retransmit a packet. Part of this means
-that any valid packet that the Manager does receive must be
-acknowledged in some way to prevent the display from continuously resending
-packets. The display can keep the protocol running as it will always know
-when the Manager has received (at least one copy of) a packet. On the
-Manager side, this means that any packet may be received more than once (if
-the response was lost) and duplicates must be ignored.
-</para>
-</chapter>
-
-<chapter id="Data_Types">
-<title>Data Types</title>
-<!-- .XS -->
-<!-- (SN Data Types -->
-<!-- .XE -->
-<para>
-<!-- .LP -->
-XDMCP packets contain several types of data. Integer values are always
-stored most significant byte first in the packet ("Big Endian" order).
-As XDMCP will not be used to transport large quantities of data, this
-restriction will not substantially hamper the efficiency of any
-implementation. Also, no padding of any sort will occur within the packets.
-</para>
-
-<informaltable frame="none">
- <tgroup cols='3' align='left'>
- <colspec colname='c1' colsep="0"/>
- <colspec colname='c2' colsep="0"/>
- <colspec colname='c3' colsep="0"/>
- <thead>
- <row>
- <entry>Type Name</entry>
- <entry>Length (Bytes)</entry>
- <entry>Description</entry>
- </row>
- </thead>
- <tbody>
- <row rowsep="0">
- <entry>CARD8</entry>
- <entry>1</entry>
- <entry>A single byte unsigned integer</entry>
- </row>
- <row rowsep="0">
- <entry>CARD16</entry>
- <entry>2</entry>
- <entry>Two byte unsigned integer</entry>
- </row>
- <row rowsep="0">
- <entry>CARD32</entry>
- <entry>4</entry>
- <entry>Four byte unsigned integer</entry>
- </row>
- <row rowsep="0">
- <entry>ARRAY8</entry>
- <entry>n+2</entry>
- <entry>
-This is actually a CARD16 followed by
-a collection of CARD8. The value of the CARD16
-field (n) specifies the number of CARD8 values to follow
- </entry>
- </row>
- <row rowsep="0">
- <entry>ARRAY16</entry>
- <entry>2*m+1</entry>
- <entry>
-This is a CARD8 (m) which specifies the
-number of CARD16 values to follow
- </entry>
- </row>
- <row rowsep="0">
- <entry>ARRAY32</entry>
- <entry>4*l+1</entry>
- <entry>
-This is a CARD8 (l) which specifies the
-number of CARD32 values to follow
- </entry>
- </row>
- <row rowsep="0">
- <entry>ARRAYofARRAY8</entry>
- <entry>?</entry>
- <entry>
-This is a CARD8 which specifies the
-number of ARRAY8 values to follow.
- </entry>
- </row>
- </tbody>
- </tgroup>
-</informaltable>
-</chapter>
-
-<chapter id="Packet_Format">
-<title>Packet Format</title>
-<!-- .XS -->
-<!-- (SN Packet Format -->
-<!-- .XE -->
-<para>
-All XDMCP packets have the following information:
-</para>
-
-<informaltable frame="none">
- <tgroup cols='3' align='left'>
- <colspec colname='c1' colsep="0"/>
- <colspec colname='c2' colsep="0"/>
- <colspec colname='c3' colsep="0"/>
- <thead>
- <row>
- <entry>Length (Bytes)</entry>
- <entry>Field Type</entry>
- <entry>Description</entry>
- </row>
- </thead>
- <tbody>
- <row rowsep="0">
- <entry>2</entry>
- <entry>CARD16</entry>
- <entry>version number</entry>
- </row>
- <row rowsep="0">
- <entry>2</entry>
- <entry>CARD16</entry>
- <entry>opcode packet header</entry>
- </row>
- <row rowsep="0">
- <entry>2</entry>
- <entry>CARD16</entry>
- <entry>n = length of remaining data in bytes</entry>
- </row>
- <row rowsep="0">
- <entry>n</entry>
- <entry>???</entry>
- <entry>packet-specific data</entry>
- </row>
- </tbody>
- </tgroup>
-</informaltable>
-
-<para>
-<!-- .LP -->
-The fields are as follows:
-</para>
-
-<variablelist>
- <varlistentry>
- <term>Version number</term>
- <listitem>
- <para>
-This specifies the version of XDMCP that generated this packet in
-case changes in this protocol are required. Displays and
-managers may choose to support older versions for compatibility.
-This field will initially be one (1).
- </para>
- </listitem>
- </varlistentry>
- <varlistentry>
- <term>Opcode</term>
- <listitem>
- <para>
-This specifies what step of the protocol this packet represents and should
-contain one of the following values (encoding provided in section below):
-<emphasis role="bold">BroadcastQuery</emphasis>,
-<emphasis role="bold">Query</emphasis>,
-<emphasis role="bold">IndirectQuery</emphasis>,
-<emphasis role="bold">ForwardQuery</emphasis>,
-<emphasis role="bold">Willing</emphasis>,
-<emphasis role="bold">Unwilling</emphasis>,
-<emphasis role="bold">Request</emphasis>,
-<emphasis role="bold">Accept</emphasis>,
-<emphasis role="bold">Decline</emphasis>,
-<emphasis role="bold">Manage</emphasis>,
-<emphasis role="bold">Refuse</emphasis>,
-<emphasis role="bold">Failed</emphasis>,
-<emphasis role="bold">KeepAlive</emphasis>
-or
-<emphasis role="bold">Alive</emphasis>.
- </para>
- </listitem>
- </varlistentry>
- <varlistentry>
- <term>Length of data in bytes</term>
- <listitem>
- <para>
-This specifies the length of the information following the first 6 bytes.
-Each packet-type has a different format and will need to be separately
-length-checked against this value. Because every data item has either an
-explicit or implicit length, this can be easily accomplished.
-Packets that have too little or too much data should be ignored.
- </para>
- </listitem>
- </varlistentry>
-</variablelist>
-<para>
-Packets should be checked to make sure that they satisfy the following
-conditions:
-</para>
-
-<orderedlist>
- <listitem>
- <para>
-They must contain valid opcodes.
- </para>
- </listitem>
- <listitem>
- <para>
-The length of the remaining data should correspond to the sum of the
-lengths of the individual remaining data items.
- </para>
- </listitem>
- <listitem>
- <para>
-The opcode should be expected (a finite state diagram is given
-in a later section).
- </para>
- </listitem>
- <listitem>
- <para>
-If the packet is of type
-<emphasis role="bold">Manage</emphasis> or
-<emphasis role="bold">Refuse</emphasis>,
-the Session ID should match the value sent in the preceding
-<emphasis role="bold">Accept</emphasis> packet.
- </para>
- </listitem>
-</orderedlist>
-</chapter>
-
-<chapter id="Protocol">
-<title>Protocol</title>
-<!-- .XS -->
-<!-- (SN Protocol -->
-<!-- .XE -->
-<para>
-Each of the opcodes is described below. Because a given packet type is only
-ever sent one way, each packet description below indicates the direction.
-Most of the packets have additional information included beyond the
-description above. The additional information is appended to the packet
-header in the order described without padding, and the length field is
-computed accordingly.
-</para>
-
-<informaltable frame="none">
- <tgroup cols='10' align='left'>
- <colspec colname='col1' colsep="0" colwidth="1*"/>
- <colspec colname='col2' colsep="0" colwidth="1*"/>
- <colspec colname='col3' colsep="0" colwidth="1*"/>
- <colspec colname='col4' colsep="0" colwidth="1*"/>
- <colspec colname='col5' colsep="0" colwidth="1*"/>
- <colspec colname='col6' colsep="0" colwidth="1*"/>
- <colspec colname='col7' colsep="0" colwidth="1*"/>
- <colspec colname='col8' colsep="0" colwidth="1*"/>
- <colspec colname='col9' colsep="0" colwidth="1*"/>
- <colspec colname='col10' colsep="0" colwidth="1*"/>
- <spanspec namest="col1" nameend="col10" spanname="col1_on" align="left"/>
- <spanspec namest="col2" nameend="col10" spanname="col2_on" align="left"/>
- <spanspec namest="col3" nameend="col10" spanname="col3_on" align="left"/>
- <spanspec namest="col4" nameend="col10" spanname="col4_on" align="left"/>
- <spanspec namest="col5" nameend="col10" spanname="col5_on" align="left"/>
- <tbody>
- <row rowsep="0">
- <entry spanname="col1_on"><emphasis role="bold">Query</emphasis></entry>
- </row>
- <row rowsep="0">
- <entry spanname="col1_on"><emphasis role="bold">BroadcastQuery</emphasis></entry>
- </row>
- <row rowsep="0">
- <entry spanname="col1_on"><emphasis role="bold">IndirectQuery</emphasis></entry>
- </row>
- <row rowsep="0">
- <entry></entry>
- <entry spanname="col2_on">Display -> Manager</entry>
- </row>
- <row rowsep="0">
- <entry></entry>
- <entry spanname="col2_on">Additional Fields:</entry>
- </row>
- <row rowsep="0">
- <entry></entry>
- <entry></entry>
- <entry spanname="col3_on">
-<emphasis>Authentication Names</emphasis>: ARRAYofARRAY8
- </entry>
- </row>
- <row rowsep="0">
- <entry></entry>
- <entry></entry>
- <entry></entry>
- <entry spanname="col4_on">
-Specifies a list of authentication names that the display supports. The
-manager will choose one of these and return it in the
-<emphasis role="bold">Willing</emphasis> packet.
- </entry>
- </row>
-<!-- AAAAAAAAAAAAA -->
- <row rowsep="0">
- <entry></entry>
- <entry></entry>
- <entry>Semantics</entry>
- </row>
- <row rowsep="0">
- <entry></entry>
- <entry></entry>
- <entry></entry>
- <entry spanname="col4_on">
-<para>
-A <function>Query</function>
-packet is sent from the display to a specific host to ask if
-that host is willing to provide management services to this display. The
-host should respond with
-<function>Willing</function>
-if it is willing to service the display or
-<function>Unwilling</function>
-if it is not.
-</para>
-
-<para>
-A
-<function>BroadcastQuery</function>
-packet is similar to the
-<function>Query</function>
-packet except that it is intended to be received by all hosts on the network
-(or subnetwork). However, unlike
-<function>Query</function>
-requests, hosts that are not willing to service the display
-should simply ignore
-<function>BroadcastQuery</function>
-requests.
-</para>
-
-<para>
-An
-<function>IndirectQuery</function>
-packet is sent to a well known manager that forwards
-the request to a larger collection of secondary managers using
-<function>ForwardQuery</function>
-packets.
-In this way, the collection of managers that respond can be grouped
-on other than network boundaries; the use of a central manager reduces
-system administrative overhead.
-The primary manager may also send a
-<function>Willing</function>
-packet in response to this packet.
-</para>
-
-<para>
-Each packet type has slightly different semantics:
-</para>
- </entry>
- </row>
- <row rowsep="0">
- <entry></entry>
- <entry></entry>
- <entry></entry>
- <entry></entry>
- <entry spanname="col5_on">
-<para>
-The
-<function>Query</function>
-packet is destined only for a single host.
-If the display is instructed to
-<function>Query</function>
-multiple managers, it will send multiple
-<function>Query</function>
-packets. The
-<function>Query</function>
-packet also demands a response from the manager, either
-<function>Willing</function>
-or
-<function>Unwilling</function>.
- </para>
- <para>
-The
-<function>BroadcastQuery</function>
-packet is sent to many hosts.
-Each manager that receives this packet will not respond with an
-<function>Unwilling</function>
-packet.
- </para>
- <para>
-The
-<function>IndirectQuery</function>
-packet is sent to only one manager with the request
-that the request be forwarded to a larger list of managers using
-<function>ForwardQuery</function>
-packets. This list is expected to be maintained at one
-central site to reduce administrative overhead.
-The function of this packet type is similar to
-<function>BroadcastQuery except that</function>
-<function>BroadcastQuery</function>
-is not forwarded.
- </para>
- </entry>
- </row>
- <row rowsep="0">
- <entry></entry>
- <entry></entry>
- <entry></entry>
- <entry spanname="col4_on">Valid Responses:</entry>
- </row>
- <row rowsep="0">
- <entry></entry>
- <entry></entry>
- <entry spanname="col3_on">
-<function>Willing</function>,
-<function>Unwilling</function>
- </entry>
- </row>
- <row rowsep="0">
- <entry></entry>
- <entry></entry>
- <entry></entry>
- <entry spanname="col4_on">Problems/Solutions:</entry>
- </row>
- <row rowsep="0">
- <entry></entry>
- <entry></entry>
- <entry spanname="col3_on">Problem:</entry>
- </row>
- <row rowsep="0">
- <entry></entry>
- <entry></entry>
- <entry></entry>
- <entry spanname="col4_on">
-<para>Not all managers receive the query packet.</para>
-<para>Indication:</para>
- </entry>
- </row>
- <row rowsep="0">
- <entry></entry>
- <entry></entry>
- <entry></entry>
- <entry></entry>
- <entry spanname="col5_on">
-None if
-<function>BroadcastQuery</function>
-or
-<function>IndirectQuery</function>
-was sent, else failure to receive
-<function>Willing</function>.
- </entry>
- </row>
- <row rowsep="0">
- <entry></entry>
- <entry></entry>
- <entry></entry>
- <entry spanname="col4_on">Solution:</entry>
- </row>
- <row rowsep="0">
- <entry></entry>
- <entry></entry>
- <entry></entry>
- <entry></entry>
- <entry spanname="col5_on">
-Repeatedly send the packet while waiting for user to choose a manager.
- </entry>
- </row>
- <row rowsep="0">
- <entry></entry>
- <entry></entry>
- <entry spanname="col3_on">
-Timeout/Retransmission policy:
- </entry>
- </row>
- <row rowsep="0">
- <entry></entry>
- <entry></entry>
- <entry></entry>
- <entry spanname="col4_on">
-An exponential backoff algorithm should be used here to reduce network load
-for long-standing idle displays. Start at 2 seconds, back off by factors of
-2 to 32 seconds, and discontinue retransmit after 126 seconds. The display
-should reset the timeout when user-input is detected. In this way, the
-display will wakeup when touched by the user.
- </entry>
- </row>
- <row rowsep="0">
- <entry spanname="col1_on">
-<function>ForwardQuery</function>
- </entry>
- </row>
- <row rowsep="0">
- <entry></entry>
- <entry spanname="col2_on">
-<para>Primary Manager -&gt; Secondary Manager</para>
-<para>Additional Fields:</para>
- </entry>
- </row>
- <row rowsep="0">
- <entry></entry>
- <entry></entry>
- <entry spanname="col3_on">
-<emphasis remap='I'>Client Address</emphasis>: ARRAY8
- </entry>
- </row>
- <row rowsep="0">
- <entry></entry>
- <entry></entry>
- <entry></entry>
- <entry spanname="col4_on">
-Specifies the network address of the client display.
- </entry>
- </row>
- <row rowsep="0">
- <entry></entry>
- <entry></entry>
- <entry spanname="col3_on">
-<emphasis remap='I'>Client Port</emphasis>: ARRAY8
- </entry>
- </row>
- <row rowsep="0">
- <entry></entry>
- <entry></entry>
- <entry></entry>
- <entry spanname="col4_on">
-Specifies an identification of the client task on the client display.
- </entry>
- </row>
- <row rowsep="0">
- <entry></entry>
- <entry></entry>
- <entry spanname="col3_on">
-<emphasis remap='I'>Authentication Names</emphasis>: ARRAYofARRAY8
- </entry>
- </row>
- <row rowsep="0">
- <entry></entry>
- <entry></entry>
- <entry></entry>
- <entry spanname="col4_on">
-Is a duplicate of Authentication Names array that was received
-in the
-<function>IndirectQuery</function>
-packet.
- </entry>
- </row>
- <row rowsep="0">
- <entry></entry>
- <entry spanname="col2_on">
-Semantics:
- </entry>
- </row>
- <row rowsep="0">
- <entry></entry>
- <entry></entry>
- <entry spanname="col3_on">
- <para>
-When primary manager receives a
-<function>IndirectQuery</function>
-packet, it is responsible for sending
-<function>ForwardQuery</function>
-packets to an appropriate list of
-managers that can provide service to the display using the same network
-type as the one the original
-<function>IndirectQuery</function>
-packet was received from.
-The Client Address and Client Port fields must contain an
-address that the secondary manager can use to reach the display also using
-this same network. Each secondary manager sends a
-<function>Willing</function>
-packet to the display if it is willing to provide service.
- </para>
-
- <para>
-<function>ForwardQuery</function>
-packets are similar to
-<function>BroadcastQuery</function>
-packets in that managers that are not willing to service
-particular displays should not send a
-<function>Unwilling</function>
-packet.
- </para>
- </entry>
- </row>
- <row rowsep="0">
- <entry></entry>
- <entry spanname="col2_on">
-Valid Responses:
- </entry>
- </row>
-
- <row rowsep="0">
- <entry></entry>
- <entry></entry>
- <entry spanname="col3_on">
-<function>Willing</function>
- </entry>
- </row>
- <row rowsep="0">
- <entry></entry>
- <entry spanname="col2_on">
-Problems/Solutions:
- </entry>
- </row>
- <row rowsep="0">
- <entry></entry>
- <entry></entry>
- <entry spanname="col3_on">
-Identical to
-<function>BroadcastQuery</function>
- </entry>
- </row>
- <row rowsep="0">
- <entry></entry>
- <entry spanname="col2_on">
-Timeout/Retransmission policy:
- </entry>
- </row>
- <row rowsep="0">
- <entry></entry>
- <entry></entry>
- <entry spanname="col3_on">
-Like all packets sent from a manager, this packet should never be
-retransmitted.
- </entry>
- </row>
-
- <row rowsep="0">
- <entry spanname="col1_on">
-<function>Willing</function>
- </entry>
- </row>
-
- <row rowsep="0">
- <entry></entry>
- <entry spanname="col2_on">
- <para>
-Manager -&gt; Display
- </para>
- <para>
-Additional Fields:
- </para>
- </entry>
- </row>
-
- <row rowsep="0">
- <entry></entry>
- <entry></entry>
- <entry spanname="col3_on">
-<emphasis remap='I'>Authentication Name</emphasis>: ARRAY8
- </entry>
- </row>
-
- <row rowsep="0">
- <entry></entry>
- <entry></entry>
- <entry></entry>
- <entry spanname="col4_on">
-<para>
-Specifies the authentication method, selected from the list offered in the
-<function>Query ,</function>
-<function>BroadcastQuery ,</function>
-or
-<function>IndirectQuery</function>
-packet that the manger expects the display to use in the subsequent
-<function>Request</function>
-packet.
-This choice should remain as constant as feasible so that displays that
-send multiple
-<function>Query</function>
-packets can use the Authentication Name from any
-<function>Willing</function>
-packet that arrives.
-</para>
-<para>
-The display is free to ignore managers that request an insufficient level
-of authentication.
-</para>
- </entry>
- </row>
-
- <row rowsep="0">
- <entry></entry>
- <entry></entry>
- <entry spanname="col3_on">
-<emphasis remap='I'>Hostname</emphasis>: ARRAY8
- </entry>
- </row>
-
- <row rowsep="0">
- <entry></entry>
- <entry></entry>
- <entry></entry>
- <entry spanname="col4_on">
-Is a human readable string describing the host from which the packet was sent.
-The protocol specifies no interpretation of the data in this field.
- </entry>
- </row>
-
- <row rowsep="0">
- <entry></entry>
- <entry></entry>
- <entry spanname="col3_on">
-<emphasis remap='I'>Status</emphasis>: ARRAY8
- </entry>
- </row>
-
- <row rowsep="0">
- <entry></entry>
- <entry></entry>
- <entry></entry>
- <entry spanname="col4_on">
-Is a human readable string describing the status of the host. This could
-include load average/number of users connected or other information. The
-protocol specifies no interpretation of the data in this field.
- </entry>
- </row>
-
-
- <row rowsep="0">
- <entry></entry>
- <entry spanname="col2_on">
-Semantics:
- </entry>
- </row>
-
- <row rowsep="0">
- <entry></entry>
- <entry></entry>
- <entry spanname="col3_on">
-A
-<function>Willing</function>
-packet is sent by managers that may service connections from
-this display. It is sent in response to either a
-<function>Query ,</function>
-<function>BroadcastQuery ,</function>
-or
-<function>ForwardQuery</function>
-but does not imply a commitment to provide service
-(for example, it may later decide that it has accepted enough
-connections already).
- </entry>
- </row>
-
- <row rowsep="0">
- <entry></entry>
- <entry spanname="col2_on">
-Problems/Solutions:
- </entry>
- </row>
-
- <row rowsep="0">
- <entry></entry>
- <entry></entry>
- <entry spanname="col3_on">
-Problem:
- </entry>
- </row>
-
- <row rowsep="0">
- <entry></entry>
- <entry></entry>
- <entry></entry>
- <entry spanname="col4_on">
-<para>
-<function>Willing</function>
-not received by the display.
-</para>
-<para>
-Indication:
-</para>
- </entry>
- </row>
-
- <row rowsep="0">
- <entry></entry>
- <entry></entry>
- <entry></entry>
- <entry></entry>
- <entry spanname="col5_on">
-None if
-<function>BroadcastQuery</function>
-or
-<function>IndirectQuery</function>
-was sent, else failure to receive
-<function>Willing .</function>
- </entry>
- </row>
-
- <row rowsep="0">
- <entry></entry>
- <entry></entry>
- <entry></entry>
- <entry spanname="col4_on">
-Solution:
- </entry>
- </row>
-
- <row rowsep="0">
- <entry></entry>
- <entry></entry>
- <entry></entry>
- <entry></entry>
- <entry spanname="col5_on">
-The display should continue to send the query until a response is received.
- </entry>
- </row>
-
-
-
- <row rowsep="0">
- <entry></entry>
- <entry spanname="col2_on">
-Timeout/Retransmission policy:
- </entry>
- </row>
-
- <row rowsep="0">
- <entry></entry>
- <entry></entry>
- <entry spanname="col3_on">
-Like all packets sent from the manager to the display, this packet should
-never be retransmitted.
- </entry>
- </row>
-
- <row rowsep="0">
- <entry spanname="col1_on">
-<function>Unwilling</function>
- </entry>
- </row>
-
- <row rowsep="0">
- <entry></entry>
- <entry spanname="col2_on">
- <para>
-Manager -&gt; Display
- </para>
- <para>
-Additional Fields:
- </para>
- </entry>
- </row>
-
- <row rowsep="0">
- <entry></entry>
- <entry></entry>
- <entry spanname="col3_on">
-The Hostname and Status fields as in the
-<function>Willing</function>
-packet.
-The Status field should indicate to the user a reason
-for the refusal of service.
- </entry>
- </row>
-
- <row rowsep="0">
- <entry></entry>
- <entry spanname="col2_on">
-Semantics:
- </entry>
- </row>
-
- <row rowsep="0">
- <entry></entry>
- <entry></entry>
- <entry spanname="col3_on">
-An
-<function>Unwilling</function>
-packet is sent by managers in response to direct
-<function>Query</function>
-requests (as opposed to
-<function>BroadcastQuery</function>
-or
-<function>IndirectQuery</function>
-requests) if the manager will not accept requests for management.
-This is typically sent by managers that wish to only service
-particular displays or that handle a limited number of displays at once.
- </entry>
- </row>
-
- <row rowsep="0">
- <entry></entry>
- <entry spanname="col2_on">
-Problems/Solutions:
- </entry>
- </row>
-
- <row rowsep="0">
- <entry></entry>
- <entry></entry>
- <entry spanname="col3_on">
-Problem:
- </entry>
- </row>
-
- <row rowsep="0">
- <entry></entry>
- <entry></entry>
- <entry></entry>
- <entry spanname="col4_on">
-<para>
-<function>Unwilling</function>
-not received by the display.
-</para>
-<para>
-Indication:
-</para>
- </entry>
- </row>
-
- <row rowsep="0">
- <entry></entry>
- <entry></entry>
- <entry></entry>
- <entry></entry>
- <entry spanname="col5_on">
-Display fails to receive
-<function>Unwilling .</function>
- </entry>
- </row>
-
- <row rowsep="0">
- <entry></entry>
- <entry></entry>
- <entry></entry>
- <entry spanname="col4_on">
-Solution:
- </entry>
- </row>
-
- <row rowsep="0">
- <entry></entry>
- <entry></entry>
- <entry></entry>
- <entry></entry>
- <entry spanname="col5_on">
-The display should continue to send
-<function>Query</function>
-messages until a response is received.
- </entry>
- </row>
-
- <row rowsep="0">
- <entry></entry>
- <entry spanname="col2_on">
-Timeout/Retransmission policy:
- </entry>
- </row>
-
- <row rowsep="0">
- <entry></entry>
- <entry></entry>
- <entry spanname="col3_on">
-Like all packets sent from the manager to the display, this packet should
-never be retransmitted.
- </entry>
- </row>
- <row rowsep="0">
- <entry spanname="col1_on">
-<function>Request</function>
- </entry>
- </row>
-
- <row rowsep="0">
- <entry></entry>
- <entry spanname="col2_on">
- <para>
-Display -&gt; Manager
- </para>
- <para>
-Additional Fields:
- </para>
- </entry>
- </row>
-
- <row rowsep="0">
- <entry></entry>
- <entry></entry>
- <entry spanname="col3_on">
-<emphasis remap='I'>Display Number</emphasis>: CARD16
- </entry>
- </row>
-
- <row rowsep="0">
- <entry></entry>
- <entry></entry>
- <entry></entry>
- <entry spanname="col4_on">
-Specifies the index of this particular server for the host
-on which the display is resident.
-This value will be zero for most autonomous displays.
- </entry>
- </row>
-
- <row rowsep="0">
- <entry></entry>
- <entry></entry>
- <entry spanname="col3_on">
-<emphasis remap='I'>Connection Types</emphasis>: ARRAY16
- </entry>
- </row>
-
- <row rowsep="0">
- <entry></entry>
- <entry></entry>
- <entry></entry>
- <entry spanname="col4_on">
-Specifies an array indicating the stream services accepted by the display.
-If the high-order byte in a particular entry is zero, the low-order byte
-corresponds to an X-protocol host family type.
- </entry>
- </row>
-
- <row rowsep="0">
- <entry></entry>
- <entry></entry>
- <entry spanname="col3_on">
-<emphasis remap='I'>Connection Addresses</emphasis>: ARRAYofARRAY8
- </entry>
- </row>
-
- <row rowsep="0">
- <entry></entry>
- <entry></entry>
- <entry></entry>
- <entry spanname="col4_on">
-For each connection type in the previous array, the corresponding entry in
-this array indicates the network address of the display device.
- </entry>
- </row>
-
- <row rowsep="0">
- <entry></entry>
- <entry></entry>
- <entry spanname="col3_on">
- <para>
-<emphasis remap='I'>Authentication Name</emphasis>: ARRAY8
- </para>
- <para>
-<emphasis remap='I'>Authentication Data</emphasis>: ARRAY8
- </para>
- </entry>
- </row>
-
- <row rowsep="0">
- <entry></entry>
- <entry></entry>
- <entry></entry>
- <entry spanname="col4_on">
-Specifies the authentication protocol that the display expects
-the manager to validate itself with. The Authentication Data is
-expected to contain data that the manager will interpret, modify
-and use to authenticate itself.
- </entry>
- </row>
-
- <row rowsep="0">
- <entry></entry>
- <entry></entry>
- <entry spanname="col3_on">
-<emphasis remap='I'>Authorization Names</emphasis>: ARRAYofARRAY8
- </entry>
- </row>
-
- <row rowsep="0">
- <entry></entry>
- <entry></entry>
- <entry></entry>
- <entry spanname="col4_on">
-Specifies which types of authorization the display supports. The
-manager may decide to reject displays with which it cannot perform
-authorization.
- </entry>
- </row>
-
- <row rowsep="0">
- <entry></entry>
- <entry></entry>
- <entry spanname="col3_on">
-<emphasis remap='I'>Manufacturer Display ID</emphasis>: ARRAY8
- </entry>
- </row>
-
- <row rowsep="0">
- <entry></entry>
- <entry></entry>
- <entry></entry>
- <entry spanname="col4_on">
-Can be used by the manager to determine how to decrypt the
-Authentication Data field in this packet. See the section below on
-Manufacturer Display ID Format.
- </entry>
- </row>
-
- <row rowsep="0">
- <entry></entry>
- <entry spanname="col2_on">
-Semantics:
- </entry>
- </row>
-
- <row rowsep="0">
- <entry></entry>
- <entry></entry>
- <entry spanname="col3_on">
-A
-<function>Request</function>
-packet is sent by a display to a specific host to request a
-session ID in preparation for a establishing a connection. If the manager
-is willing to service a connection to this display, it should return an
-<function>Accept</function>
-packet with a valid session ID and should be ready for a subsequent
-<function>Manage</function>
-request. Otherwise, it should return a
-<function>Decline</function>
-packet.
- </entry>
- </row>
-
- <row rowsep="0">
- <entry></entry>
- <entry spanname="col2_on">
-Valid Responses:
- </entry>
- </row>
-
- <row rowsep="0">
- <entry></entry>
- <entry></entry>
- <entry spanname="col3_on">
-<function>Accept ,</function>
-<function>Decline</function>
- </entry>
- </row>
-
- <row rowsep="0">
- <entry></entry>
- <entry spanname="col2_on">
-Problems/Solutions:
- </entry>
- </row>
-
- <row rowsep="0">
- <entry></entry>
- <entry></entry>
- <entry spanname="col3_on">
-Problem:
- </entry>
- </row>
-
- <row rowsep="0">
- <entry></entry>
- <entry></entry>
- <entry></entry>
- <entry spanname="col4_on">
-Request not received by manager.
- </entry>
- </row>
-
- <row rowsep="0">
- <entry></entry>
- <entry></entry>
- <entry></entry>
- <entry spanname="col4_on">
-Indication:
- </entry>
- </row>
-
- <row rowsep="0">
- <entry></entry>
- <entry></entry>
- <entry></entry>
- <entry></entry>
- <entry spanname="col5_on">
-Display timeout waiting for response.
- </entry>
- </row>
-
- <row rowsep="0">
- <entry></entry>
- <entry></entry>
- <entry></entry>
- <entry spanname="col4_on">
-Solution:
- </entry>
- </row>
-
- <row rowsep="0">
- <entry></entry>
- <entry></entry>
- <entry></entry>
- <entry></entry>
- <entry spanname="col5_on">
-Display resends
-<function>Request</function>
-message.
- </entry>
- </row>
-
-
- <row rowsep="0">
- <entry></entry>
- <entry></entry>
- <entry></entry>
- <entry spanname="col4_on">
-Problem:
- </entry>
- </row>
-
- <row rowsep="0">
- <entry></entry>
- <entry></entry>
- <entry></entry>
- <entry></entry>
- <entry spanname="col5_on">
-Message received out of order by manager.
- </entry>
- </row>
-
- <row rowsep="0">
- <entry></entry>
- <entry></entry>
- <entry></entry>
- <entry spanname="col4_on">
-Indication:
- </entry>
- </row>
-
- <row rowsep="0">
- <entry></entry>
- <entry></entry>
- <entry></entry>
- <entry></entry>
- <entry spanname="col5_on">
-None.
- </entry>
- </row>
-
- <row rowsep="0">
- <entry></entry>
- <entry></entry>
- <entry></entry>
- <entry spanname="col4_on">
-Solution:
- </entry>
- </row>
-
- <row rowsep="0">
- <entry></entry>
- <entry></entry>
- <entry></entry>
- <entry></entry>
- <entry spanname="col5_on">
-Each time a
-<function>Request</function>
-is sent, the manager sends the Session ID
-associated with the next session in the
-<function>Accept .</function>
-If that next session is not yet started,
-the manager will simply resend with the same Session ID.
-If the session is in progress, the manager will reply
-with a new Session ID; in which case, the
-<function>Accept</function>
-will be discarded by the display.
- </entry>
- </row>
-
- <row rowsep="0">
- <entry></entry>
- <entry spanname="col2_on">
-Timeout/Retransmission policy:
- </entry>
- </row>
-
- <row rowsep="0">
- <entry></entry>
- <entry></entry>
- <entry spanname="col3_on">
-Timeout after 2 seconds, exponential backoff to 32 seconds.
-After no more than 126 seconds, give up and report an error to the user.
- </entry>
- </row>
-
- <row rowsep="0">
- <entry spanname="col1_on">
-<function>Accept</function>
- </entry>
- </row>
-
- <row rowsep="0">
- <entry></entry>
- <entry spanname="col2_on">
- <para>
-Manager -&gt; Display
- </para>
- <para>
-Additional Fields:
- </para>
- </entry>
- </row>
-
- <row rowsep="0">
- <entry></entry>
- <entry></entry>
- <entry spanname="col3_on">
-<emphasis remap='I'>Session ID</emphasis>: CARD32
- </entry>
- </row>
-
- <row rowsep="0">
- <entry></entry>
- <entry></entry>
- <entry></entry>
- <entry spanname="col4_on">
-Identifies the session that can be started by the manager.
- </entry>
- </row>
-
- <row rowsep="0">
- <entry></entry>
- <entry></entry>
- <entry spanname="col3_on">
- <para>
-<emphasis remap='I'>Authentication Name</emphasis>: ARRAY8
- </para>
- <para>
-<emphasis remap='I'>Authentication Data</emphasis>: ARRAY8
- </para>
- </entry>
- </row>
-
- <row rowsep="0">
- <entry></entry>
- <entry></entry>
- <entry></entry>
- <entry spanname="col4_on">
-Is the data sent back to the display to authenticate the manager.
-If the Authentication Data is not the value expected by the display, it
-should terminate the protocol at this point and display an error to the user.
- </entry>
- </row>
-
- <row rowsep="0">
- <entry></entry>
- <entry></entry>
- <entry spanname="col3_on">
- <para>
-<emphasis remap='I'>Authorization Name</emphasis>: ARRAY8
- </para>
- <para>
-<emphasis remap='I'>Authorization Data</emphasis>: ARRAY8
- </para>
- </entry>
- </row>
-
- <row rowsep="0">
- <entry></entry>
- <entry></entry>
- <entry></entry>
- <entry spanname="col4_on">
-Is the data sent to the display to indicate the type of authorization the
-manager will be using in the first call to
-<function>XOpenDisplay</function>
-after the
-<function>Manage</function>
-packet is received.
- </entry>
- </row>
-
-
- <row rowsep="0">
- <entry></entry>
- <entry spanname="col2_on">
-Semantics:
- </entry>
- </row>
-
- <row rowsep="0">
- <entry></entry>
- <entry></entry>
- <entry spanname="col3_on">
-<para>
-An
-<function>Accept</function>
-packet is sent by a manager in response to a
-<function>Request</function>
-packet if the manager is willing to establish a connection for the display.
-The Session ID is used to identify this connection from any preceding
-ones and will be used by the display in its subsequent
-<function>Manage</function>
-packet.
-The Session ID is a 32-bit number that is incremented each time an
-<function>Accept</function>
-packet is sent as it must be unique over a reasonably long period of time.
-</para>
-<para>
-If the authentication information is invalid, a
-<function>Decline</function>
-packet will be returned with an appropriate
-<function>Status</function>
-message.
-</para>
- </entry>
- </row>
-
- <row rowsep="0">
- <entry></entry>
- <entry spanname="col2_on">
-Problems/Solutions:
- </entry>
- </row>
-
- <row rowsep="0">
- <entry></entry>
- <entry></entry>
- <entry spanname="col3_on">
-Problem:
- </entry>
- </row>
-
- <row rowsep="0">
- <entry></entry>
- <entry></entry>
- <entry></entry>
- <entry spanname="col4_on">
-<function>Accept</function>
-or
-<function>Decline</function>
-not received by display.
- </entry>
- </row>
-
- <row rowsep="0">
- <entry></entry>
- <entry></entry>
- <entry></entry>
- <entry spanname="col4_on">
-Indication:
- </entry>
- </row>
-
- <row rowsep="0">
- <entry></entry>
- <entry></entry>
- <entry></entry>
- <entry></entry>
- <entry spanname="col5_on">
-Display timeout waiting for response to
-<function>Request .</function>
- </entry>
- </row>
-
- <row rowsep="0">
- <entry></entry>
- <entry></entry>
- <entry></entry>
- <entry spanname="col4_on">
-Solution:
- </entry>
- </row>
-
- <row rowsep="0">
- <entry></entry>
- <entry></entry>
- <entry></entry>
- <entry></entry>
- <entry spanname="col5_on">
-Display resends
-<function>Request</function>
-message.
- </entry>
- </row>
-
- <row rowsep="0">
- <entry></entry>
- <entry></entry>
- <entry spanname="col3_on">
-Problem:
- </entry>
- </row>
-
- <row rowsep="0">
- <entry></entry>
- <entry></entry>
- <entry></entry>
- <entry spanname="col4_on">
-Message received out of order by display.
- </entry>
- </row>
-
- <row rowsep="0">
- <entry></entry>
- <entry></entry>
- <entry></entry>
- <entry spanname="col4_on">
-Indication:
- </entry>
- </row>
-
- <row rowsep="0">
- <entry></entry>
- <entry></entry>
- <entry></entry>
- <entry></entry>
- <entry spanname="col5_on">
-Display receives
-<function>Accept</function>
-after
-<function>Manage</function>
-has been sent.
- </entry>
- </row>
-
- <row rowsep="0">
- <entry></entry>
- <entry></entry>
- <entry></entry>
- <entry spanname="col4_on">
-Solution:
- </entry>
- </row>
-
- <row rowsep="0">
- <entry></entry>
- <entry></entry>
- <entry></entry>
- <entry></entry>
- <entry spanname="col5_on">
-Display discards
-<function>Accept</function>
-messages after it has sent a
-<function>Manage</function>
-message.
- </entry>
- </row>
-
- <row rowsep="0">
- <entry></entry>
- <entry spanname="col2_on">
-Timeout/Retransmission policy:
- </entry>
- </row>
-
- <row rowsep="0">
- <entry></entry>
- <entry></entry>
- <entry spanname="col3_on">
-Like all packets sent from the manager to the display, this packet should
-never be retransmitted.
- </entry>
- </row>
-
- <row rowsep="0">
- <entry spanname="col1_on">
-<function>Decline</function>
- </entry>
- </row>
-
- <row rowsep="0">
- <entry></entry>
- <entry spanname="col2_on">
- <para>
-Manager -&gt; Display
- </para>
- <para>
-Additional Fields:
- </para>
- </entry>
- </row>
-
- <row rowsep="0">
- <entry></entry>
- <entry></entry>
- <entry spanname="col3_on">
-<emphasis remap='I'>Status</emphasis>: ARRAY8
- </entry>
- </row>
-
- <row rowsep="0">
- <entry></entry>
- <entry></entry>
- <entry></entry>
- <entry spanname="col4_on">
-Is a human readable string indicating the reason for refusal of
-service.
- </entry>
- </row>
-
- <row rowsep="0">
- <entry></entry>
- <entry></entry>
- <entry spanname="col3_on">
- <para>
-<emphasis remap='I'>Authentication Name</emphasis>:
-ARRAY8
- </para>
- <para>
-<emphasis remap='I'>Authentication Data</emphasis>:
-ARRAY8
- </para>
- </entry>
- </row>
-
- <row rowsep="0">
- <entry></entry>
- <entry></entry>
- <entry></entry>
- <entry spanname="col4_on">
-Is the data sent back to the display to authenticate the manager. If the
-Authentication Data is not the value expected by the display, it
-should terminate the protocol at this point and display an error to the user.
- </entry>
- </row>
-
- <row rowsep="0">
- <entry></entry>
- <entry spanname="col2_on">
-Semantics:
- </entry>
- </row>
-
- <row rowsep="0">
- <entry></entry>
- <entry></entry>
- <entry spanname="col3_on">
-A
-<function>Decline</function>
-packet is sent by a manager in response to a
-<function>Request</function>
-packet if the manager is unwilling to establish a connection for the
-display.
-This is allowed even if the manager had responded
-<function>Willing</function>
-to a previous query.
- </entry>
- </row>
-
- <row rowsep="0">
- <entry></entry>
- <entry spanname="col2_on">
-Problems/Solutions:
- </entry>
- </row>
-
- <row rowsep="0">
- <entry></entry>
- <entry></entry>
- <entry spanname="col3_on">
-Same as for
-<function>Accept .</function>
- </entry>
- </row>
-
- <row rowsep="0">
- <entry></entry>
- <entry spanname="col2_on">
-Timeout/Retransmission policy:
- </entry>
- </row>
-
- <row rowsep="0">
- <entry></entry>
- <entry></entry>
- <entry spanname="col3_on">
-Like all packets sent from a manager to a display, this packet should never
-be retransmitted.
- </entry>
- </row>
-
- <row rowsep="0">
- <entry spanname="col1_on">
-<function>Manage</function>
- </entry>
- </row>
-
- <row rowsep="0">
- <entry></entry>
- <entry spanname="col2_on">
- <para>
-Display -&gt; Manager
- </para>
- <para>
-Additional Fields:
- </para>
- </entry>
- </row>
-
- <row rowsep="0">
- <entry></entry>
- <entry></entry>
- <entry spanname="col3_on">
-<emphasis remap='I'>Session ID</emphasis>: CARD32
- </entry>
- </row>
-
- <row rowsep="0">
- <entry></entry>
- <entry></entry>
- <entry></entry>
- <entry spanname="col4_on">
-Should contain the nonzero session ID returned in the
-<function>Accept</function>
-packet.
- </entry>
- </row>
-
- <row rowsep="0">
- <entry></entry>
- <entry></entry>
- <entry spanname="col3_on">
-<emphasis remap='I'>Display Number</emphasis>: CARD16
- </entry>
- </row>
-
- <row rowsep="0">
- <entry></entry>
- <entry></entry>
- <entry></entry>
- <entry spanname="col4_on">
-Must match the value sent in the previous
-<function>Request</function>
-packet.
- </entry>
- </row>
-
- <row rowsep="0">
- <entry></entry>
- <entry></entry>
- <entry spanname="col3_on">
-<emphasis remap='I'>Display Class</emphasis>: ARRAY8
- </entry>
- </row>
-
- <row rowsep="0">
- <entry></entry>
- <entry></entry>
- <entry></entry>
- <entry spanname="col4_on">
-Specifies the class of the display.
-See the Display Class Format section,
-which discusses the format of this field.
- </entry>
- </row>
-
-
- <row rowsep="0">
- <entry></entry>
- <entry spanname="col2_on">
-Semantics:
- </entry>
- </row>
-
- <row rowsep="0">
- <entry></entry>
- <entry></entry>
- <entry spanname="col3_on">
-A
-<function>Manage</function>
-packet is sent by a display to ask the manager to begin a
-session on the display. If the Session ID is correct the manager
-should open a connection; otherwise, it should respond with a
-<function>Refuse</function>
-or
-<function>Failed</function>
-packet, unless the Session ID matches a currently
-running session or a session that has not yet successfully opened the
-display but has not given up the attempt. In this latter case, the
-<function>Manage</function>
-packet should be ignored.
-This will work as stream connections give positive success indication
-to both halves of the stream, and positive failure indication
-to the connection initiator (which will eventually generate a
-<function>Failed</function>
-packet).
- </entry>
- </row>
-
- <row rowsep="0">
- <entry></entry>
- <entry spanname="col2_on">
-Valid Responses:
- </entry>
- </row>
-
- <row rowsep="0">
- <entry></entry>
- <entry></entry>
- <entry spanname="col3_on">
-X connection with correct auth info,
-<function>Refuse ,</function>
-<function>Failed .</function>
- </entry>
- </row>
-
- <row rowsep="0">
- <entry></entry>
- <entry spanname="col2_on">
-Problems/Solutions:
- </entry>
- </row>
-
- <row rowsep="0">
- <entry></entry>
- <entry></entry>
- <entry spanname="col3_on">
-Problem:
- </entry>
- </row>
-
- <row rowsep="0">
- <entry></entry>
- <entry></entry>
- <entry></entry>
- <entry spanname="col4_on">
-<function>Manage</function>
-not received by manager.
- </entry>
- </row>
-
- <row rowsep="0">
- <entry></entry>
- <entry></entry>
- <entry></entry>
- <entry spanname="col4_on">
-Indication:
- </entry>
- </row>
-
- <row rowsep="0">
- <entry></entry>
- <entry></entry>
- <entry></entry>
- <entry></entry>
- <entry spanname="col5_on">
-Display timeout waiting for response.
- </entry>
- </row>
-
- <row rowsep="0">
- <entry></entry>
- <entry></entry>
- <entry></entry>
- <entry spanname="col4_on">
-Solution:
- </entry>
- </row>
-
- <row rowsep="0">
- <entry></entry>
- <entry></entry>
- <entry></entry>
- <entry></entry>
- <entry spanname="col5_on">
-Display resends
-<function>Manage</function>
-message.
- </entry>
- </row>
-
-
- <row rowsep="0">
- <entry></entry>
- <entry></entry>
- <entry spanname="col3_on">
-Problem:
- </entry>
- </row>
-
- <row rowsep="0">
- <entry></entry>
- <entry></entry>
- <entry></entry>
- <entry spanname="col4_on">
-<function>Manage</function>
-received out of order by manager.
- </entry>
- </row>
-
- <row rowsep="0">
- <entry></entry>
- <entry></entry>
- <entry></entry>
- <entry spanname="col4_on">
-Indication:
- </entry>
- </row>
-
- <row rowsep="0">
- <entry></entry>
- <entry></entry>
- <entry></entry>
- <entry></entry>
- <entry spanname="col5_on">
-Session already in progress with matching Session ID.
- </entry>
- </row>
-
- <row rowsep="0">
- <entry></entry>
- <entry></entry>
- <entry></entry>
- <entry spanname="col4_on">
-Solution:
- </entry>
- </row>
-
- <row rowsep="0">
- <entry></entry>
- <entry></entry>
- <entry></entry>
- <entry></entry>
- <entry spanname="col5_on">
-<function>Manage</function>
-packet ignored.
- </entry>
- </row>
-
- <row rowsep="0">
- <entry></entry>
- <entry></entry>
- <entry></entry>
- <entry spanname="col4_on">
-Indication:
- </entry>
- </row>
-
- <row rowsep="0">
- <entry></entry>
- <entry></entry>
- <entry></entry>
- <entry></entry>
- <entry spanname="col5_on">
-Session ID does not match next Session ID.
- </entry>
- </row>
-
- <row rowsep="0">
- <entry></entry>
- <entry></entry>
- <entry></entry>
- <entry spanname="col4_on">
-Solution:
- </entry>
- </row>
-
- <row rowsep="0">
- <entry></entry>
- <entry></entry>
- <entry></entry>
- <entry></entry>
- <entry spanname="col5_on">
-<function>Refuse</function>
-message is sent.
- </entry>
- </row>
-
-
- <row rowsep="0">
- <entry></entry>
- <entry></entry>
- <entry spanname="col3_on">
-Problem:
- </entry>
- </row>
-
- <row rowsep="0">
- <entry></entry>
- <entry></entry>
- <entry></entry>
- <entry spanname="col4_on">
-Display cannot be opened on selected stream.
- </entry>
- </row>
-
- <row rowsep="0">
- <entry></entry>
- <entry></entry>
- <entry></entry>
- <entry spanname="col4_on">
-Indication:
- </entry>
- </row>
-
- <row rowsep="0">
- <entry></entry>
- <entry></entry>
- <entry></entry>
- <entry></entry>
- <entry spanname="col5_on">
-Display connection setup fails.
- </entry>
- </row>
-
- <row rowsep="0">
- <entry></entry>
- <entry></entry>
- <entry></entry>
- <entry spanname="col4_on">
-Solution:
- </entry>
- </row>
-
- <row rowsep="0">
- <entry></entry>
- <entry></entry>
- <entry></entry>
- <entry></entry>
- <entry spanname="col5_on">
-<function>Failed</function>
-message is sent including a human readable reason.
- </entry>
- </row>
-
- <row rowsep="0">
- <entry></entry>
- <entry></entry>
- <entry spanname="col3_on">
-Problem:
- </entry>
- </row>
-
- <row rowsep="0">
- <entry></entry>
- <entry></entry>
- <entry></entry>
- <entry spanname="col4_on">
-Display open does not succeed before a second manage packet is received
-because of a timeout occuring in the display.
- </entry>
- </row>
-
- <row rowsep="0">
- <entry></entry>
- <entry></entry>
- <entry></entry>
- <entry spanname="col4_on">
-Indication:
- </entry>
- </row>
-
- <row rowsep="0">
- <entry></entry>
- <entry></entry>
- <entry></entry>
- <entry></entry>
- <entry spanname="col5_on">
-<function>Manage</function>
-packet received with Session ID matching the session
-attempting to connect to the display.
- </entry>
- </row>
-
- <row rowsep="0">
- <entry></entry>
- <entry></entry>
- <entry></entry>
- <entry spanname="col4_on">
-Solution:
- </entry>
- </row>
-
- <row rowsep="0">
- <entry></entry>
- <entry></entry>
- <entry></entry>
- <entry></entry>
- <entry spanname="col5_on">
-<function>Manage</function>
-packet is ignored. As the stream connection will either
-succeed, which will result in an active session, or the stream will
-eventually give up hope of connecting and send a
-<function>Failed</function>
-packet; no response to this
-<function>Manage</function>
-packet is necessary.
- </entry>
- </row>
-
- <row rowsep="0">
- <entry></entry>
- <entry spanname="col2_on">
-Timeout/Retransmission policy:
- </entry>
- </row>
-
- <row rowsep="0">
- <entry></entry>
- <entry></entry>
- <entry spanname="col3_on">
-Timeout after 2 seconds, exponential backoff to 32 seconds. After no more
-than 126 seconds, give up and report an error to the user.
- </entry>
- </row>
-
- <row rowsep="0">
- <entry spanname="col1_on">
-<function>Refuse</function>
- </entry>
- </row>
-
- <row rowsep="0">
- <entry></entry>
- <entry spanname="col2_on">
- <para>
-Manager -&gt; Display
- </para>
- <para>
-Additional Fields:
- </para>
- </entry>
- </row>
-
- <row rowsep="0">
- <entry></entry>
- <entry></entry>
- <entry spanname="col3_on">
-<emphasis remap='I'>Session ID</emphasis>: CARD32
- </entry>
- </row>
-
- <row rowsep="0">
- <entry></entry>
- <entry></entry>
- <entry></entry>
- <entry spanname="col4_on">
-Should be set to the Session ID received in the
-<function>Manage</function>
-packet.
- </entry>
- </row>
-
-
- <row rowsep="0">
- <entry></entry>
- <entry spanname="col2_on">
-Semantics:
- </entry>
- </row>
-
- <row rowsep="0">
- <entry></entry>
- <entry></entry>
- <entry spanname="col3_on">
-A
-<function>Refuse</function>
-packet is sent by a manager when the Session ID received in the
-<function>Manage</function>
-packet does not match the current Session ID.
-The display should assume that it received an old
-<function>Accept</function>
-packet and should resend its
-<function>Request</function>
-packet.
- </entry>
- </row>
-
- <row rowsep="0">
- <entry></entry>
- <entry spanname="col2_on">
-Problems/Solutions:
- </entry>
- </row>
-
- <row rowsep="0">
- <entry></entry>
- <entry></entry>
- <entry spanname="col3_on">
-Problem:
- </entry>
- </row>
-
- <row rowsep="0">
- <entry></entry>
- <entry></entry>
- <entry></entry>
- <entry spanname="col4_on">
-Error message is lost.
- </entry>
- </row>
-
- <row rowsep="0">
- <entry></entry>
- <entry></entry>
- <entry></entry>
- <entry spanname="col4_on">
-Indication:
- </entry>
- </row>
-
- <row rowsep="0">
- <entry></entry>
- <entry></entry>
- <entry></entry>
- <entry></entry>
- <entry spanname="col5_on">
-Display times out waiting for
-new connection,
-<function>Refuse</function>
-or
-<function>Failed .</function>
- </entry>
- </row>
-
- <row rowsep="0">
- <entry></entry>
- <entry></entry>
- <entry></entry>
- <entry spanname="col4_on">
-Solution:
- </entry>
- </row>
-
- <row rowsep="0">
- <entry></entry>
- <entry></entry>
- <entry></entry>
- <entry></entry>
- <entry spanname="col5_on">
-Display resends
-<function>Manage</function>
-message.
- </entry>
- </row>
-
-
-
- <row rowsep="0">
- <entry></entry>
- <entry spanname="col2_on">
-Timeout/Retransmission policy:
- </entry>
- </row>
-
- <row rowsep="0">
- <entry></entry>
- <entry></entry>
- <entry spanname="col3_on">
-Like all packets sent from a manager to a display, this packet should never be
-retransmitted.
- </entry>
- </row>
-
- <row rowsep="0">
- <entry spanname="col1_on">
-<function>Failed</function>
- </entry>
- </row>
-
- <row rowsep="0">
- <entry></entry>
- <entry spanname="col2_on">
- <para>
-Manager -&gt; Display
- </para>
- <para>
-Additional Fields:
- </para>
- </entry>
- </row>
-
- <row rowsep="0">
- <entry></entry>
- <entry></entry>
- <entry spanname="col3_on">
-<emphasis remap='I'>Session ID</emphasis>: CARD32
- </entry>
- </row>
-
- <row rowsep="0">
- <entry></entry>
- <entry></entry>
- <entry></entry>
- <entry spanname="col4_on">
-Should be set to the Session ID received in the
-<function>Manage</function>
-packet.
- </entry>
- </row>
-
- <row rowsep="0">
- <entry></entry>
- <entry></entry>
- <entry spanname="col3_on">
-<emphasis remap='I'>Status</emphasis>: ARRAY8
- </entry>
- </row>
-
- <row rowsep="0">
- <entry></entry>
- <entry></entry>
- <entry></entry>
- <entry spanname="col4_on">
-Is a human readable string indicating the reason for failure.
- </entry>
- </row>
-
-
- <row rowsep="0">
- <entry></entry>
- <entry spanname="col2_on">
-Semantics:
- </entry>
- </row>
-
- <row rowsep="0">
- <entry></entry>
- <entry></entry>
- <entry spanname="col3_on">
-A
-<function>Failed</function>
-packet is sent by a manager when it has problems establishing
-the initial X connection in response to the
-<function>Manage</function>
-packet.
- </entry>
- </row>
-
- <row rowsep="0">
- <entry></entry>
- <entry spanname="col2_on">
-Problems/Solutions
- </entry>
- </row>
-
- <row rowsep="0">
- <entry></entry>
- <entry></entry>
- <entry spanname="col3_on">
-Same as for
-<function>Refuse .</function>
- </entry>
- </row>
-
- <row rowsep="0">
- <entry spanname="col1_on">
-<function>KeepAlive</function>
- </entry>
- </row>
-
- <row rowsep="0">
- <entry></entry>
- <entry spanname="col2_on">
- <para>
-Display -&gt; Manager
- </para>
- <para>
-Additional Fields:
- </para>
- </entry>
- </row>
-
- <row rowsep="0">
- <entry></entry>
- <entry></entry>
- <entry spanname="col3_on">
-<emphasis remap='I'>Display Number</emphasis>: CARD16
- </entry>
- </row>
-
- <row rowsep="0">
- <entry></entry>
- <entry></entry>
- <entry></entry>
- <entry spanname="col4_on">
-Set to the display index for the display host.
- </entry>
- </row>
-
- <row rowsep="0">
- <entry></entry>
- <entry></entry>
- <entry spanname="col3_on">
-<emphasis remap='I'>Session ID</emphasis>: CARD32
- </entry>
- </row>
-
- <row rowsep="0">
- <entry></entry>
- <entry></entry>
- <entry></entry>
- <entry spanname="col4_on">
-Should be set to the Session ID received in the
-<function>Manage</function>
-packet during the negotiation for the current session.
- </entry>
- </row>
-
- <row rowsep="0">
- <entry></entry>
- <entry spanname="col2_on">
-Sematics:
- </entry>
- </row>
-
- <row rowsep="0">
- <entry></entry>
- <entry></entry>
- <entry spanname="col3_on">
- <para>
-A
-<function>KeepAlive</function>
-packet can be sent at any time during the session by a
-display to discover if the manager is running.
-The manager should respond with
-<function>Alive</function>
-whenever it receives this type of packet.
- </para>
- <para>
-This allows the display to discover when the manager host
-is no longer running.
-A display is not required to send
-<function>KeepAlive</function>
-packets and, upon lack of receipt of
-<function>Alive</function>
-packets, is not required to perform any specific action.
- </para>
- <para>
-The expected use of this packet is to terminate an active session when the
-manager host or network link fails. The display should keep track of the
-time since any packet has been received from the manager host and use
-<function>KeepAlive</function>
-packets when a substantial time has elapsed since the
-most recent packet.
- </para>
- </entry>
- </row>
-
- <row rowsep="0">
- <entry></entry>
- <entry spanname="col2_on">
-Valid Responses:
- </entry>
- </row>
-
- <row rowsep="0">
- <entry></entry>
- <entry></entry>
- <entry spanname="col3_on">
-<function>Alive</function>
- </entry>
- </row>
-
- <row rowsep="0">
- <entry></entry>
- <entry spanname="col2_on">
-Problems/Solutions:
- </entry>
- </row>
-
- <row rowsep="0">
- <entry></entry>
- <entry></entry>
- <entry spanname="col3_on">
-Problem:
- </entry>
- </row>
-
- <row rowsep="0">
- <entry></entry>
- <entry></entry>
- <entry></entry>
- <entry spanname="col4_on">
-Manager does not receive the packet or display does not receive the response.
- </entry>
- </row>
-
-
- <row rowsep="0">
- <entry></entry>
- <entry></entry>
- <entry></entry>
- <entry spanname="col4_on">
-Indication:
- </entry>
- </row>
-
- <row rowsep="0">
- <entry></entry>
- <entry></entry>
- <entry></entry>
- <entry></entry>
- <entry spanname="col5_on">
-No
-<function>Alive</function>
-packet is returned.
- </entry>
- </row>
-
- <row rowsep="0">
- <entry></entry>
- <entry></entry>
- <entry></entry>
- <entry spanname="col4_on">
-Solution:
- </entry>
- </row>
-
- <row rowsep="0">
- <entry></entry>
- <entry></entry>
- <entry></entry>
- <entry></entry>
- <entry spanname="col5_on">
-Retransmit the packet with an exponential backoff; start at 2 seconds and
-assume the host is not up after no less than 30 seconds.
- </entry>
- </row>
-
- <row rowsep="0">
- <entry spanname="col1_on">
-<function>Alive</function>
- </entry>
- </row>
-
- <row rowsep="0">
- <entry></entry>
- <entry spanname="col2_on">
- <para>
-Manager -&gt; Display
- </para>
- <para>
-Additional Fields:
- </para>
- </entry>
- </row>
-
- <row rowsep="0">
- <entry></entry>
- <entry></entry>
- <entry spanname="col3_on">
-<emphasis remap='I'>Session Running</emphasis>: CARD8
- </entry>
- </row>
-
- <row rowsep="0">
- <entry></entry>
- <entry></entry>
- <entry></entry>
- <entry spanname="col4_on">
-Indicates that the session identified by Session ID is
-currently active. The value is zero if no session is active
-or one if a session
-is active.
- </entry>
- </row>
-
- <row rowsep="0">
- <entry></entry>
- <entry></entry>
- <entry spanname="col3_on">
-<emphasis remap='I'>Session ID</emphasis>: CARD32
- </entry>
- </row>
-
- <row rowsep="0">
- <entry></entry>
- <entry></entry>
- <entry></entry>
- <entry spanname="col4_on">
-Specifies the ID of the currently running session; if any.
-When no session is active this field should be zero.
- </entry>
- </row>
-
-
- <row rowsep="0">
- <entry></entry>
- <entry spanname="col2_on">
-Semantics:
- </entry>
- </row>
-
- <row rowsep="0">
- <entry></entry>
- <entry></entry>
- <entry spanname="col3_on">
-An
-<function>Alive</function>
-packet is sent in response to a
-<function>KeepAlive</function>
-request.
-If a session is currently active on the display, the manager includes the
-Session ID in the packet. The display can use this information to
-determine the status of the manager.
- </entry>
- </row>
- </tbody>
- </tgroup>
-</informaltable>
-
-</chapter>
-
-<chapter id="Session_Termination">
-<title>Session Termination</title>
-<para>
-When the session is over, the initial connection with the display (the one
-that acknowledges the
-<function>Manage</function>
-packet) will be closed by the manager.
-If only a single session was active on the display,
-all other connections should be closed by the display
-and the display should be reset. If multiple sessions
-are active simultaneously and the display can identify which connections
-belong to the terminated sesssion, those connections should be closed.
-Otherwise, all connections should be closed and the display reset only when
-all sessions have been terminated (that is, all initial connections closed).
-</para>
-
-<para>
-The session may also be terminated at any time by the display if the
-managing host no longer responds to
-<function>KeepAlive</function>
-packets.
-The exact time-outs for sending
-<function>KeepAlive</function>
-packets is not specified in this protocol as the trade off
-should not be fixed between loading an otherwise idle system with spurious
-<function>KeepAlive</function>
-packets and not noticing that the manager host is down for a long time.
-</para>
-</chapter>
-
-<chapter id="State_Diagrams">
-<title>State Diagrams</title>
-<!-- .XS -->
-<!-- (SN State Diagrams -->
-<!-- .XE -->
-<para>
-<!-- .LP -->
-The following state diagrams are designed to cover all actions of both
-the display and the manager. Any packet that is received out-of-sequence
-will be ignored.
-</para>
-<para>
-<!-- .LP -->
-Display:
-</para>
-
-<variablelist>
- <varlistentry>
- <term><emphasis remap='I'>start</emphasis>:</term>
- <listitem>
- <para>
-User-requested connect to one host -&gt; <emphasis remap='I'>query</emphasis>
- </para>
- <para>
-User-requested connect to some host -&gt; <emphasis remap='I'>broadcast</emphasis>
- </para>
- <para>
-User-requested connect to site host-list -&gt; <emphasis remap='I'>indirect</emphasis>
- </para>
- </listitem>
- </varlistentry>
- <varlistentry>
- <term><emphasis remap='I'>query</emphasis>:</term>
- <listitem>
- <para>
-Send <function>Query</function> packet
--&gt; <emphasis remap='I'>collect-query</emphasis>
- </para>
- </listitem>
- </varlistentry>
- <varlistentry>
- <term><emphasis remap='I'>collect-query</emphasis>:</term>
- <listitem>
- <para>
-Receive <function>Willing</function> -&gt;
-<emphasis remap='I'>start-connection</emphasis>
- </para>
- <para>
-Receive <function>Unwilling</function> -&gt;
-<emphasis remap='I'>stop-connection</emphasis>
- </para>
- <para>
-Timeout -&gt; <emphasis remap='I'>query</emphasis>
- </para>
- </listitem>
- </varlistentry>
-
- <varlistentry>
- <term><emphasis remap='I'>broadcast</emphasis>:</term>
- <listitem>
- <para>
-Send <function>BroadcastQuery</function> packet
- </para>
- <para>
--&gt; <emphasis remap='I'>collect-broadcast-query</emphasis>
- </para>
- </listitem>
- </varlistentry>
- <varlistentry>
- <term><emphasis remap='I'>collect-broadcast-query</emphasis>:</term>
- <listitem>
- <para>
-Receive <function>Willing</function> -&gt;
-<emphasis remap='I'>update-broadcast-willing</emphasis>
- </para>
- <para>
-User-requested connect to one host -&gt;
-<emphasis remap='I'>start-connection</emphasis>
- </para>
- <para>
-Timeout -&gt; <emphasis remap='I'>broadcast</emphasis>
- </para>
- </listitem>
- </varlistentry>
- <varlistentry>
- <term><emphasis remap='I'>update-broadcast-willing</emphasis>:</term>
- <listitem>
- <para>
-Add new host to the host list presented to the user
- </para>
- <para>
--&gt; <emphasis remap='I'>collect-broadcast-query</emphasis>
- </para>
- </listitem>
- </varlistentry>
- <varlistentry>
- <term><emphasis remap='I'>indirect</emphasis>:</term>
- <listitem>
- <para>
-Send <function>IndirectQuery</function> packet
- </para>
- <para>
--&gt; <emphasis remap='I'>collect-indirect-query</emphasis>
- </para>
- </listitem>
- </varlistentry>
- <varlistentry>
- <term><emphasis remap='I'>collect-indirect-query</emphasis>:</term>
- <listitem>
- <para>
-Receive <function>Willing</function> -&gt;
-<emphasis remap='I'>update-indirect-willing</emphasis>
- </para>
- <para>
-User-requested connect to one host -&gt;
-<emphasis remap='I'>start-connection</emphasis>
- </para>
- <para>
-Timeout -&gt; <emphasis remap='I'>indirect</emphasis>
- </para>
- </listitem>
- </varlistentry>
- <varlistentry>
- <term><emphasis remap='I'>update-indirect-willing</emphasis>:</term>
- <listitem>
- <para>
-Add new host to the host list presented to the user
- </para>
- <para>
--&gt; <emphasis remap='I'>collect-indirect-query</emphasis>
- </para>
- </listitem>
- </varlistentry>
-
- <varlistentry>
- <term><emphasis remap='I'>start-connection</emphasis>:</term>
- <listitem>
- <para>
-Send <function>Request</function> packet
- </para>
- <para>
--&gt; <emphasis remap='I'>await-request-response</emphasis>
- </para>
- </listitem>
- </varlistentry>
- <varlistentry>
- <term><emphasis remap='I'>await-request-response</emphasis>:</term>
- <listitem>
- <para>
-Receive <function>Accept</function> -&gt;
-<emphasis remap='I'>manage</emphasis>
- </para>
- <para>
-Receive <function>Decline</function> -&gt;
-<emphasis remap='I'>stop-connection</emphasis>
- </para>
- <para>
-Timeout -&gt; <emphasis remap='I'>start-connection</emphasis>
- </para>
- </listitem>
- </varlistentry>
- <varlistentry>
- <term><emphasis remap='I'>manage</emphasis>:</term>
- <listitem>
- <para>
-Save Session ID
- </para>
- <para>
-Send <function>Manage</function> packet with Session ID
- </para>
- <para>
--&gt; <emphasis remap='I'>await-manage-response</emphasis>
- </para>
- </listitem>
- </varlistentry>
- <varlistentry>
- <term><emphasis remap='I'>await-manage-response</emphasis>:</term>
- <listitem>
- <para>
-Receive <function>XOpenDisplay :</function> -&gt;
-<emphasis remap='I'>run-session</emphasis>
- </para>
- <para>
-Receive <function>Refuse</function> with matching Session ID
--&gt; <emphasis remap='I'>start-connection</emphasis>
- </para>
- <para>
-Receive <function>Failed</function> with matching Session ID
--&gt; <emphasis remap='I'>stop-connection</emphasis>
- </para>
- <para>
-Timeout -&gt; <emphasis remap='I'>manage</emphasis>
- </para>
- </listitem>
- </varlistentry>
- <varlistentry>
- <term><emphasis remap='I'>stop-connection</emphasis>:</term>
- <listitem>
- <para>
-Display cause of termination to user
- </para>
- <para>
--&gt; <emphasis remap='I'>start</emphasis>
- </para>
- </listitem>
- </varlistentry>
- <varlistentry>
- <term><emphasis remap='I'>run-session</emphasis>:</term>
- <listitem>
- <para>
-Decide to send <function>KeepAlive</function> packet -&gt;
-<emphasis remap='I'>keep-alive</emphasis>
- </para>
- <para>
-wait close of first display connection
- </para>
- <para>
--&gt; <emphasis remap='I'>reset-display</emphasis>
- </para>
- </listitem>
- </varlistentry>
- <varlistentry>
- <term><emphasis remap='I'>keep-alive</emphasis>:</term>
- <listitem>
- <para>
-Send <function>KeepAlive</function> packet with current Session ID
- </para>
- <para>
--&gt; <emphasis remap='I'>await-alive</emphasis>
- </para>
- </listitem>
- </varlistentry>
- <varlistentry>
- <term><emphasis remap='I'>await-alive</emphasis>:</term>
- <listitem>
- <para>
-Receive <function>Alive</function> with matching Session ID -&gt;
-<emphasis remap='I'>run-session</emphasis>
- </para>
- <para>
-Receive <function>Alive</function> with nonmatching Session ID
-or FALSE Session Running -&gt; <emphasis remap='I'>reset-display</emphasis>
- </para>
- <para>
-Final timeout without receiving <function>Alive</function>
-packet -&gt; <emphasis remap='I'>reset-display</emphasis>
- </para>
- <para>
-Timeout -&gt; <emphasis remap='I'>keep-alive</emphasis>
- </para>
- </listitem>
- </varlistentry>
- <varlistentry>
- <term><emphasis remap='I'>reset-display</emphasis>:</term>
- <listitem>
- <para>
-(if possible) -&gt; close all display connections associated with this session
- </para>
- <para>
-Last session -&gt; close all display connections
- </para>
- <para>
--&gt; <emphasis remap='I'>start</emphasis>
- </para>
- </listitem>
- </varlistentry>
-</variablelist>
-
-
-<para>
-Manager:
-</para>
-
-<variablelist>
- <varlistentry>
- <term><emphasis remap='I'>idle</emphasis>:</term>
- <listitem>
- <para>
-Receive <function>Query</function> -&gt;
-<emphasis remap='I'>query-respond</emphasis>
- </para>
- <para>
-Receive
-<function>BroadcastQuery</function>
--&gt; <emphasis remap='I'>broadcast-respond</emphasis>
- </para>
- <para>
-Receive
-<function>IndirectQuery</function>
--&gt; <emphasis remap='I'>indirect-respond</emphasis>
- </para>
- <para>
-Receive
-<function>ForwardQuery</function>
--&gt; <emphasis remap='I'>forward-respond</emphasis>
-Receive
- </para>
- <para>
-<function>Request</function>
--&gt; <emphasis remap='I'>request-respond</emphasis>
- </para>
- <para>
-Receive
-<function>Manage</function>
--&gt; <emphasis remap='I'>manage</emphasis>
- </para>
- <para>
-An active session terminates
--&gt; <emphasis remap='I'>finish-session</emphasis>
- </para>
- <para>
-Receive <function>KeepAlive</function>
--&gt; <emphasis remap='I'>send-alive</emphasis>
- </para>
- <para>
--&gt; <emphasis remap='I'>idle</emphasis>
- </para>
- </listitem>
- </varlistentry>
- <varlistentry>
- <term><emphasis remap='I'>query-respond</emphasis>:</term>
- <listitem>
- <para>
-If willing to manage -&gt; <emphasis remap='I'>send-willing</emphasis>
- </para>
- <para>
--&gt; <emphasis remap='I'>send-unwilling</emphasis>
- </para>
- </listitem>
- </varlistentry>
- <varlistentry>
- <term><emphasis remap='I'>broadcast-respond</emphasis>:</term>
- <listitem>
- <para>
-If willing to manage -&gt; <emphasis remap='I'>send-willing</emphasis>
- </para>
- <para>
--&gt; <emphasis remap='I'>idle</emphasis>
- </para>
- </listitem>
- </varlistentry>
- <varlistentry>
- <term><emphasis remap='I'>indirect-respond</emphasis>:</term>
- <listitem>
- <para>
-Send <function>ForwardQuery</function>
-packets to all managers on redirect list
- </para>
- <para>
-If willing to manage -&gt; <emphasis remap='I'>send-willing</emphasis>
- </para>
- <para>
--&gt; <emphasis remap='I'>idle</emphasis>
- </para>
- </listitem>
- </varlistentry>
- <varlistentry>
- <term><emphasis remap='I'>forward-respond</emphasis>:</term>
- <listitem>
- <para>
-Decode destination address, if willing to manage -&gt;
-<emphasis remap='I'>send-willing</emphasis>
- </para>
- <para>
--&gt; <emphasis remap='I'>idle</emphasis>
- </para>
- </listitem>
- </varlistentry>
- <varlistentry>
- <term><emphasis remap='I'>send-willing</emphasis>:</term>
- <listitem>
- <para>
-Send <function>Willing</function> packet
- </para>
- <para>
--&gt; <emphasis remap='I'>idle</emphasis>
- </para>
- </listitem>
- </varlistentry>
- <varlistentry>
- <term><emphasis remap='I'>send-unwilling</emphasis>:</term>
- <listitem>
- <para>
-Send <function>Unwilling</function> packet
--&gt; <emphasis remap='I'>idle</emphasis>
- </para>
- </listitem>
- </varlistentry>
- <varlistentry>
- <term><emphasis remap='I'>request-respond</emphasis>:</term>
- <listitem>
- <para>
-If manager is willing to allow a session on display
--&gt; <emphasis remap='I'>accept-session</emphasis>
- </para>
- <para>
--&gt; <emphasis remap='I'>decline-session</emphasis>
- </para>
- </listitem>
- </varlistentry>
- <varlistentry>
- <term><emphasis remap='I'>accept-session</emphasis>:</term>
- <listitem>
- <para>
-Generate Session ID and save Session ID, display address, and
-display number somewhere
- </para>
- <para>
-Send <function>Accept</function> packet
- </para>
- <para>
--&gt; <emphasis remap='I'>idle</emphasis>
- </para>
- </listitem>
- </varlistentry>
- <varlistentry>
- <term><emphasis remap='I'>decline-session</emphasis>:</term>
- <listitem>
- <para>
-Send <function>Decline</function> packet
- </para>
- <para>
--&gt; <emphasis remap='I'>idle</emphasis>
- </para>
- </listitem>
- </varlistentry>
- <varlistentry>
- <term><emphasis remap='I'>manage</emphasis>:</term>
- <listitem>
- <para>
-If Session ID matches saved Session ID -&gt;
-<emphasis remap='I'>run-session</emphasis>
- </para>
- <para>
-If Session ID matches Session ID of session in process of
-starting up, or currently active session -&gt;
-<emphasis remap='I'>idle</emphasis>
- </para>
- <para>
--&gt; <emphasis remap='I'>refuse</emphasis>
- </para>
- </listitem>
- </varlistentry>
- <varlistentry>
- <term><emphasis remap='I'>refuse</emphasis>:</term>
- <listitem>
- <para>
-Send <function>Refuse</function> packet
- </para>
- <para>
--&gt; <emphasis remap='I'>idle</emphasis>
- </para>
- </listitem>
- </varlistentry>
- <varlistentry>
- <term><emphasis remap='I'>run-session</emphasis>:</term>
- <listitem>
- <para>
-Terminate any session in progress
- </para>
- <para>
-<function>XOpenDisplay</function>
- </para>
- <para>
-Open display succeeds -&gt;
-<emphasis remap='I'>start-session</emphasis>
- </para>
- <para>
--&gt; <emphasis remap='I'>failed</emphasis>
- </para>
- </listitem>
- </varlistentry>
- <varlistentry>
- <term><emphasis remap='I'>failed</emphasis>:</term>
- <listitem>
- <para>
-Send <function>Failed</function> packet
- </para>
- <para>
--&gt; <emphasis remap='I'>idle</emphasis>
- </para>
- </listitem>
- </varlistentry>
- <varlistentry>
- <term><emphasis remap='I'>start-session</emphasis>:</term>
- <listitem>
- <para>
-Start a new session
- </para>
- <para>
--&gt; <emphasis remap='I'>idle</emphasis>
- </para>
- </listitem>
- </varlistentry>
- <varlistentry>
- <term><emphasis remap='I'>finish-session</emphasis>:</term>
- <listitem>
- <para>
-<function>XCloseDisplay</function>
- </para>
- <para>
--&gt; <emphasis remap='I'>idle</emphasis>
- </para>
- </listitem>
- </varlistentry>
- <varlistentry>
- <term><emphasis remap='I'>send-alive</emphasis>:</term>
- <listitem>
- <para>
-Send <function>Alive</function> packet containing current status
- </para>
- <para>
--&gt; <emphasis remap='I'>idle</emphasis>
- </para>
- </listitem>
- </varlistentry>
-</variablelist>
-
-</chapter>
-
-<chapter id="Protocol_Encoding">
-<title>Protocol Encoding</title>
-<para>
-When XDMCP is implemented on top of the Internet User Datagram Protocol (UDP),
-port number 177 is to be used. When using UDP over IPv4, Broadcast Query
-packets are sent via UDP broadcast. When using UDP over IPv6, Broadcast Query
-packets are sent via multicast, either to an address in the IANA registered
-XDMCP multicast address range of
-FF0<emphasis remap='I'>X</emphasis>:0:0:0:0:0:0:12B
-(where the <emphasis remap='I'>X</emphasis> is replaced by a valid scope id)
-or to a locally assigned
-multicast address. The version number in all packets will be 1.
-Packet opcodes are 16-bit integers.
-</para>
-
-<informaltable frame="none">
- <tgroup cols='2' align='left'>
- <colspec colname='c1' colsep="0"/>
- <colspec colname='c2' colsep="0"/>
- <thead>
- <row>
- <entry>Packet Name</entry>
- <entry>Encoding</entry>
- </row>
- </thead>
- <tbody>
- <row rowsep="0">
- <entry>BroadcastQuery</entry>
- <entry>1</entry>
- </row>
- <row rowsep="0">
- <entry>Query</entry>
- <entry>2</entry>
- </row>
- <row rowsep="0">
- <entry>IndirectQuery</entry>
- <entry>3</entry>
- </row>
- <row rowsep="0">
- <entry>ForwardQuery</entry>
- <entry>4</entry>
- </row>
- <row rowsep="0">
- <entry>Willing</entry>
- <entry>5</entry>
- </row>
- <row rowsep="0">
- <entry>Unwilling</entry>
- <entry>6</entry>
- </row>
- <row rowsep="0">
- <entry>Request</entry>
- <entry>7</entry>
- </row>
- <row rowsep="0">
- <entry>Accept</entry>
- <entry>8</entry>
- </row>
- <row rowsep="0">
- <entry>Decline</entry>
- <entry>9</entry>
- </row>
- <row rowsep="0">
- <entry>Manage</entry>
- <entry>10</entry>
- </row>
- <row rowsep="0">
- <entry>Refuse</entry>
- <entry>11</entry>
- </row>
- <row rowsep="0">
- <entry>Failed</entry>
- <entry>12</entry>
- </row>
- <row rowsep="0">
- <entry>KeepAlive</entry>
- <entry>13
-<footnote><para>
-A previous version of this document incorrectly reversed the opcodes of
-<emphasis role="bold">Alive</emphasis> and
-<emphasis role="bold">KeepAlive</emphasis>.
-</para></footnote>
- </entry>
- </row>
- <row rowsep="0">
- <entry>Alive</entry>
- <entry>14
-<footnote><para>
-A previous version of this document incorrectly reversed the opcodes of
-<emphasis role="bold">Alive</emphasis> and
-<emphasis role="bold">KeepAlive</emphasis>.
-</para></footnote>
- </entry>
- </row>
- </tbody>
- </tgroup>
-</informaltable>
-
-<para>
-Per packet information follows:
-</para>
-
-<para>
-<function>Query</function>,
-<function>BroadcastQuery</function>,
-<function>IndirectQuery</function>
-</para>
-
-<literallayout class="monospaced">
- 2 CARD16 version number (always 1)
- 2 CARD16 opcode (always Query, BroadcastQuery or IndirectQuery)
- 2 CARD16 length
- 1 CARD8 number of Authentication Names sent (m)
- 2 CARD16 length of first Authentication Name (m<emphasis role="subscript">1</emphasis>)
- m<emphasis role="subscript">1</emphasis> CARD8 first Authentication Name
- ... Other Authentication Names
-</literallayout>
-
-<para>
-Note that these three packets are identical except for the opcode field.
-</para>
-
-<literallayout class="monospaced">
-<function>ForwardQuery</function>
- 2 CARD16 version number (always 1)
- 2 CARD16 opcode (always ForwardQuery)
- 2 CARD16 length
- 2 CARD16 length of Client Address (m)
- m CARD8 Client Address
- 2 CARD16 length of Client Port (n)
- n CARD8 Client Port
- 1 CARD8 number of Authentication Names sent (o)
- 2 CARD16 length of first Authentication Name (o<emphasis role="subscript">1</emphasis>)
- o<emphasis role="subscript">1</emphasis> CARD8 first Authentication Name
- ... Other Authentication Names
-</literallayout>
-
-<literallayout class="monospaced">
-<function>Willing</function>
- 2 CARD16 version number (always 1)
- 2 CARD16 opcode (always Willing)
- 2 CARD16 length (6 + m + n + o)
- 2 CARD16 Length of Authentication Name (m)
- m CARD8 Authentication Name
- 2 CARD16 Hostname length (n)
- n CARD8 Hostname
- 2 CARD16 Status length (o)
- o CARD8 Status
-</literallayout>
-
-<literallayout class="monospaced">
-<function>Unwilling</function>
- 2 CARD16 version number (always 1)
- 2 CARD16 opcode (always Unwilling)
- 2 CARD16 length (4 + m + n)
- 2 CARD16 Hostname length (m)
- m CARD8 Hostname
- 2 CARD16 Status length (n)
- n CARD8 Status
-</literallayout>
-
-<literallayout class="monospaced">
-<function>Request</function>
- 2 CARD16 version number (always 1)
- 2 CARD16 opcode (always Request)
- 2 CARD16 length
- 2 CARD16 Display Number
- 1 CARD8 Count of Connection Types (m)
- 2xm CARD16 Connection Types
- 1 CARD8 Count of Connection Addresses (n)
- 2 CARD16 Length of first Connection Address (n<emphasis role="subscript">1</emphasis>)
- n<emphasis role="subscript">1</emphasis> CARD8 First Connection Address
- ... Other connection addresses
- 2 CARD16 Length of Authentication Name (o)
- o CARD8 Authentication Name
- 2 CARD16 Length of Authentication Data (p)
- p CARD8 Authentication Data
- 1 CARD8 Count of Authorization Names (q)
- 2 CARD16 Length of first Authorization Name (q<emphasis role="subscript">1</emphasis>)
- q<emphasis role="subscript">1</emphasis> CARD8 First Authorization Name
- ... Other authorization names
- 2 CARD16 Length of Manufacturer Display ID (r)
- r CARD8 Manufacturer Display ID
-</literallayout>
-
-<literallayout class="monospaced">
-<function>Accept</function>
- 2 CARD16 version number (always 1)
- 2 CARD16 opcode (always Accept)
- 2 CARD16 length (12 + n + m + o + p)
- 4 CARD32 Session ID
- 2 CARD16 Length of Authentication Name (n)
- n CARD8 Authentication Name
- 2 CARD16 Length of Authentication Data (m)
- m CARD8 Authentication Data
- 2 CARD16 Length of Authorization Name (o)
- o CARD8 Authorization Name
- 2 CARD16 Length of Authorization Data (p)
- p CARD8 Authorization Data
-</literallayout>
-
-<literallayout class="monospaced">
-<function>Decline</function>
- 2 CARD16 version number (always 1)
- 2 CARD16 opcode (always Decline)
- 2 CARD16 length (6 + m + n + o)
- 2 CARD16 Length of Status (m)
- m CARD8 Status
- 2 CARD16 Length of Authentication Name (n)
- n CARD8 Authentication Name
- 2 CARD16 Length of Authentication Data (o)
- o CARD8 Authentication Data
-</literallayout>
-
-<literallayout class="monospaced">
-<function>Manage</function>
- 2 CARD16 version number (always 1)
- 2 CARD16 opcode (always Manage)
- 2 CARD16 length (8 + m)
- 4 CARD32 Session ID
- 2 CARD16 Display Number
- 2 CARD16 Length of Display Class (m)
- m CARD8 Display Class
-</literallayout>
-
-<literallayout class="monospaced">
-<function>Refuse</function>
- 2 CARD16 version number (always 1)
- 2 CARD16 opcode (always Refuse)
- 2 CARD16 length (4)
- 4 CARD32 Session ID
-</literallayout>
-
-<literallayout class="monospaced">
-<function>Failed</function>
- 2 CARD16 version number (always 1)
- 2 CARD16 opcode (always Failed)
- 2 CARD16 length (6 + m)
- 4 CARD32 Session ID
- 2 CARD16 Length of Status (m)
- m CARD8 Status
-</literallayout>
-
-<literallayout class="monospaced">
-<function>KeepAlive</function>
- 2 CARD16 version number (always 1)
- 2 CARD16 opcode (always KeepAlive)
- 2 CARD16 length (6)
- 2 CARD16 Display Number
- 4 CARD32 Session ID
-</literallayout>
-
-<literallayout class="monospaced">
-<function>Alive</function>
- 2 CARD16 version number (always 1)
- 2 CARD16 opcode (always Alive)
- 2 CARD16 length (5)
- 1 CARD8 Session Running (0: not running 1: running)
- 4 CARD32 Session ID (0: not running)
-</literallayout>
-</chapter>
-
-<chapter id="Display_Class_Format">
-<title>Display Class Format</title>
-<!-- .XS -->
-<!-- (SN Display Class Format -->
-<!-- .XE -->
-<para>
-The Display Class field of the
-<function>Manage</function>
-packet is used by the display manager to collect common sorts of
-displays into manageable groups. This field is a string encoded of
-ISO-LATIN-1 characters in the following format:
-</para>
-
-<literallayout class="monospaced">
-<emphasis remap='I'>ManufacturerID</emphasis>-<emphasis remap='I'>ModelNumber</emphasis>
-</literallayout>
-
-<para>
-Both elements of this string must exclude characters of the set
-{ <function>-</function>,
-<function>.</function>,
-<function>:</function>,
-<function>*</function>,
-<function>?</function>,
-<emphasis remap='I'>&lt;space&gt;</emphasis> }.
-The ManufacturerID is a string that should be registered
-with the X Consortium.
-The ModelNumber is designed to identify characteristics of the display
-within the manufacturer's product line.
-This string should be documented in the users manual for the
-particular device and should probably not be specifiable by the
-display user to avoid unexpected configuration errors.
-</para>
-</chapter>
-
-<chapter id="Manufacturer_Display_ID_Format">
-<title>Manufacturer Display ID Format</title>
-<!-- .XS -->
-<!-- (SN Manufacturer Display ID Format -->
-<!-- .XE -->
-<para>
-To authenticate the manager, the display and manager will share a private
-key.
-The manager, then, must be able to discover which key to use for a
-particular device.
-The Manufacturer Display ID field of the
-<function>Request</function>
-packet is intended for this purpose. Typically, the manager host will
-contain a map between this number and the key. This field is intended to be
-unique per display, possibly the ethernet address of the display in the form:
-</para>
-
-<literallayout class="monospaced">
--Ethernet-8:0:2b:a:f:d2
-</literallayout>
-
-<para>
-It can also be a string of the form:
-</para>
-
-<literallayout class="monospaced">
-<emphasis remap='I'>ManufacturerID</emphasis>-<emphasis remap='I'>ModelNumber</emphasis>-<emphasis remap='I'>SerialNumber</emphasis>
-</literallayout>
-
-<para>
-The ManufacturerID, ModelNumber and SerialNumber are encoded using
-ISO-LATIN-1 characters, excluding {
-<function>-</function>,
-<function>.</function>,
-<function>*</function>,
-<function>?</function>,
-<emphasis remap='I'>&lt;space&gt;</emphasis> }
-</para>
-
-<para>
-When the display is shipped to a customer, it should include both the
-Manufacturer Display ID and the private key in the documentation set.
-This information should not be modifiable by the display user.
-</para>
-
-</chapter>
-
-<chapter id="Authentication">
-<title>Authentication</title>
-<!-- .XS -->
-<!-- (SN Authentication -->
-<!-- .XE -->
-<para>
-In an environment where authentication is not needed, XDMCP can disable
-authentication by having the display send empty Authentication Name
-and Authentication Data fields in the
-<function>Request</function>
-packet.
-In this case, the manager will not attempt to authenticate itself.
-Other authentication protocols may be developed, depending on local needs.
-</para>
-
-<para>
-In an unsecure environment, the display must be able to verify that the
-source of the various packets is a trusted manager. These packets will
-contain authentication information. As an example of such a system, the
-following discussion describes the "XDM-AUTHENTICATION-1" authentication
-system. This system uses a 56-bit shared private key, and 64 bits of
-authentication data. An associated example X authorization protocol
-"XDM-AUTHORIZATION-1" will also be discussed. The 56-bit key is represented
-as a 64-bit number in network order (big endian). This means that the first
-octet in the representation will be zero. When incrementing a 64-bit value,
-the 8 octets of data will be interpreted in network order (big endian).
-That is, the last octet will be incremented, subsequent carries propogate
-towards the first octet.
-</para>
-
-<para>
-Assumptions:
-</para>
-
-<orderedlist>
- <listitem>
- <para>
-The display and manager share a private key. This key could be programmed
-into the display by the manufacturer and shipped with the unit. It must not
-be available from the display itself, but should allow the value to be
-modified in some way. The system administrator would be responsible for
-managing a database of terminal keys.
- </para>
- </listitem>
- <listitem>
- <para>
-The display can generate random authentication numbers.
- </para>
- </listitem>
-</orderedlist>
-
-<para>
-Some definitions first:
-</para>
-
-<!-- FIXME: -->
-<!-- double chk math symbols, use mathml to display them? -->
-<itemizedlist>
- <listitem>
- <para>
-{&variable.D;}<superscript>&variable.kappa;</superscript> = encryption of plain text D by key &variable.kappa;
- </para>
- </listitem>
- <listitem>
- <para>
-{&variable.Delta;}*<superscript>&variable.kappa;</superscript> = decryption of crypto text &variable.Delta; with key &variable.kappa;
- </para>
- </listitem>
- <listitem>
- <para>
-&variable.tau; = private key shared by display and manager
- </para>
- </listitem>
- <listitem>
- <para>
-&variable.rho; = 64 bit random number generated by display
- </para>
- </listitem>
- <listitem>
- <para>
-&variable.alpha; = authentication data in XDMCP packets
- </para>
- </listitem>
- <listitem>
- <para>
-&variable.sigma; = per-session private key, generated by manager
- </para>
- </listitem>
- <listitem>
- <para>
-&variable.beta; = authorization data
- </para>
- </listitem>
-</itemizedlist>
-
-<para>
-Encryption will use the Data Encryption Standard (DES, FIPS 46-3); blocks
-shorter than 64 bits will be zero-filled
-on the right to 64 bits. Blocks longer than 64 bits will use block chaining:
-</para>
-<para>
-{&variable.D;}<superscript>&variable.kappa;</superscript> = {&variable.D;<subscript>1</subscript>}<superscript>&variable.kappa;</superscript> {&variable.D;<subscript>2</subscript> xor {&variable.D;<subscript>1</subscript>}<superscript>&variable.kappa;</superscript>}<superscript>&variable.kappa;</superscript>
-</para>
-
-<para>
-The display generates the first authentication data in the
-<function>Request</function>
-packet:
-</para>
-
-<para>
-&variable.alpha;<subscript>Request</subscript> = {&variable.rho;}<superscript>&variable.tau;</superscript>
-</para>
-
-<para>
-For the <function>Accept</function>
-packet, the manager decrypts the initial message and returns
-&variable.alpha;<subscript>Accept</subscript>:
-
-</para>
-
-<para>
-&variable.rho; = {&variable.alpha;<subscript>Request</subscript>}*<superscript>&variable.tau;</superscript>
-</para>
-
-<para>
-&variable.alpha;<subscript>Accept</subscript> = { &variable.rho; + 1}<superscript>&variable.tau;</superscript>
-</para>
-
-<para>
-The <function>Accept</function>
-packet also contains the authorization intended for use by
-the X server. A description of authorization type "XDM-AUTHORIZATION-1"
-follows.
-</para>
-
-<para>
-The <function>Accept</function>
-packet contains the authorization name
-"XDM-AUTHORIZATION-1". The authorization data is the string:
-</para>
-<para>
-&variable.beta;<subscript>Accept</subscript> = {&variable.sigma;}<superscript>&variable.tau;</superscript>
-</para>
-
-<para>
-To create authorization information for connection setup with the X server
-using the XDM-AUTHORIZATION-1 authorization protocol, the client computes the
-following:
-</para>
-<para>
-&variable.N; = X client identifier
-</para>
-<para>
-&variable.T; = Current time in seconds on client host (32 bits)
-</para>
-<para>
-&variable.beta; = {&variable.rho;&variable.N;&variable.T;}<superscript>&variable.sigma;</superscript>
-</para>
-
-<para>
-For TCP connections &variable.N; is 48 bits long and contains the 32-bit IPv4 address of
-the client host followed by the 16-bit port number of the client socket.
-Formats for other connections must be registered.
-The resulting value, &variable.beta;, is 192 bits of authorization data that is sent
-in the connection setup to the server. The server receives the packet,
-decrypts the contents. To accept the connection, the following must hold:
-</para>
-
-<itemizedlist>
- <listitem>
- <para>
-&variable.rho; must match the value generated for the most recent XDMCP negotiation.
- </para>
- </listitem>
- <listitem>
- <para>
-&variable.T; must be within 1200 seconds of the internally stored time. If no time
-been received before, the current time is set to &variable.T;.
- </para>
- </listitem>
- <listitem>
- <para>
-No packet containing the same pair (&variable.N;, &variable.T;) can have been received
-in the last 1200 seconds (20 minutes).
- </para>
- </listitem>
-</itemizedlist>
-</chapter>
-</book>
+<?xml version="1.0" encoding="UTF-8" ?>
+<!DOCTYPE book PUBLIC "-//OASIS//DTD DocBook XML V4.3//EN"
+ "http://www.oasis-open.org/docbook/xml/4.3/docbookx.dtd" [
+<!--
+ variable names used in equation markup in the authentication chapter
+ FIXME: Replace with mathml?
+ -->
+<!ENTITY variable.D "<emphasis role='italic'>D</emphasis>">
+<!ENTITY variable.N "<emphasis role='italic'>N</emphasis>">
+<!ENTITY variable.T "<emphasis role='italic'>T</emphasis>">
+<!ENTITY variable.Delta "<emphasis role='italic'>&Delta;</emphasis>">
+<!ENTITY variable.alpha "<emphasis role='italic'>&alpha;</emphasis>">
+<!ENTITY variable.beta "<emphasis role='italic'>&beta;</emphasis>">
+<!ENTITY variable.kappa "<emphasis role='italic'>&kappa;</emphasis>">
+<!ENTITY variable.rho "<emphasis role='italic'>&rho;</emphasis>">
+<!ENTITY variable.sigma "<emphasis role='italic'>&sigma;</emphasis>">
+<!ENTITY variable.tau "<emphasis role='italic'>&tau;</emphasis>">
+<!ENTITY % defs SYSTEM "defs.ent"> %defs;
+]>
+
+<book id="xdmcp">
+
+<bookinfo>
+ <title>X Display Manager Control Protocol</title>
+ <subtitle>X.Org Standard</subtitle>
+ <releaseinfo>X Version 11, Release &fullrelvers;</releaseinfo>
+ <releaseinfo>Version 1.1</releaseinfo>
+ <authorgroup>
+ <author>
+ <firstname>Keith</firstname><surname>Packard</surname>
+ <affiliation>
+ <orgname>Massachusetts Institute of Technology</orgname>
+ <orgdiv>Laboratory for Computer Science</orgdiv>
+ <orgdiv>X Consortium</orgdiv>
+ </affiliation>
+ </author>
+ </authorgroup>
+
+ <copyright><year>1989</year><year>2004</year>
+ <holder>The Open Group</holder></copyright>
+
+<legalnotice>
+
+
+
+<para>
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+</para>
+<para>
+The above copyright notice and this permission notice shall be included in
+all copies or substantial portions of the Software.
+</para>
+<para>
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+OPEN GROUP BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN
+AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
+CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+</para>
+<para>
+Except as contained in this notice, the name of The Open Group shall not be
+used in advertising or otherwise to promote the sale, use or other dealings
+in this Software without prior written authorization from The Open Group.
+</para>
+
+<para>
+<emphasis remap='I'>X Window System</emphasis> is a trademark of The Open Group.
+</para>
+</legalnotice>
+</bookinfo>
+
+<chapter id="Purpose_and_Goals">
+<title>Purpose and Goals</title>
+<!-- .XS -->
+<!-- (SN Purpose and Goals -->
+<!-- .XE -->
+<para>
+<!-- .LP -->
+The purpose of the X Display Manager Control Protocol (XDMCP)
+is to provide a uniform mechanism for an autonomous
+display to request login service from a remote host.
+By autonomous, we mean
+the display consists of hardware and processes that are independent of any
+particular host where login service is desired. (For example, the server
+cannot simply be started by a
+<function>fork/exec</function>
+sequence on the host.)
+An X terminal (screen, keyboard, mouse, processor, network interface)
+is a prime example of an autonomous display.
+</para>
+
+<para>
+From the point of view of the end user, it is very important to make
+autonomous displays as easy to use as traditional hardwired character
+terminals. Specifically, you can typically just power on a hardwired
+terminal and be greeted with a login prompt. The same should be possible
+with autonomous displays. However, in a network environment with multiple
+hosts, the end user may want to choose which host(s) to connect to. In an
+environment with many displays and many hosts, a site administrator may want
+to associate particular collections of hosts with particular displays. We
+would like to support the following options:
+</para>
+
+<itemizedlist>
+ <listitem>
+ <para>
+The display has a single, fixed host to which it should connect. It should be
+possible to power on the display and receive a login prompt, without user
+intervention.
+ </para>
+ </listitem>
+ <listitem>
+ <para>
+Any one of several hosts on a network or subnetwork may be acceptable
+for accepting login from the display.
+(For example, the user's file systems can be mounted onto
+any such host, providing comparable environments.) It should be possible
+for the display to broadcast to find such hosts and to have the display
+either automatically choose a host or present the possible hosts to the
+user for selection.
+ </para>
+ </listitem>
+ <listitem>
+ <para>
+The display has a fixed set of hosts that it can connect to. It should be
+possible for the display to have that set stored in RAM, but it should also be
+possible for a site administrator to be able to maintain host sets for a
+large number of displays using a centralized facility, without having to
+interact (physically or electronically) with each individual display.
+Particular hosts should be allowed to refuse login service, based on
+whatever local criteria are desired.
+ </para>
+ </listitem>
+</itemizedlist>
+
+<para>
+The control protocol should be designed in such a way that it can be used over
+a reasonable variety of communication transport layers. In fact, it is quite
+desirable if every major network protocol family that supports the standard X
+protocol is also capable of supporting XDMCP, because the end result of XDMCP
+negotiation will be standard X protocol connections to the display.
+However, because the number of displays per host may be large,
+a connection-based protocol appears less desirable
+than a connection-less protocol. For this reason the protocol is designed
+to use datagram services with the display responsible for sequencing and
+retransmission.
+</para>
+<para>
+<!-- .LP -->
+To keep the burden on displays at a minimum (because display cost is not
+a factor that can be ignored), it is desirable that displays not be required
+to maintain permanent state (across power cycles) for the purposes
+of the control protocol,
+and it is desirable to keep required state at a minimum while the
+display is powered on.
+</para>
+<para>
+<!-- .LP -->
+Security is an important consideration and must be an integral part of the
+design. The important security goals in the context of XDMCP are:
+</para>
+<itemizedlist>
+ <listitem>
+ <para>
+It should be possible for the display to verify that it is communicating
+with a legitimate host login service. Because the user will present
+credentials (for example, password) to this service,
+it is important to avoid spoof attacks.
+ </para>
+ </listitem>
+ <listitem>
+ <para>
+It should be possible for the display and the login service to negotiate the
+authorization mechanism to be used for the standard X protocol.
+ </para>
+ </listitem>
+ <listitem>
+ <para>
+It should be possible to provide the same level of security in verifying the
+login service as is provided by the negotiated authorization mechanism.
+ </para>
+ </listitem>
+ <listitem>
+ <para>
+Because there are no firm standards yet in the area of security,
+XDMCP must be flexible enough to accomodate a variety of security mechanisms.
+ </para>
+ </listitem>
+</itemizedlist>
+</chapter>
+
+<chapter id="Overview_of_the_Protocol">
+<title>Overview of the Protocol</title>
+<!-- .XS -->
+<!-- (SN Overview of the Protocol -->
+<!-- .XE -->
+<para>
+<!-- .LP -->
+XDMCP is designed to provide authenticated access to display management
+services for remote displays. A new network server, called a \fIDisplay
+Manager\fP, will use XDMCP to communicate with displays to negotiate the
+startup of X sessions. The protocol allows the display to authenticate the
+manager. It also allows most of the configuration information to be
+centralized with the manager and to ease the burden of system administration
+in a large network of displays.
+The essential goal is to provide plug-and-play
+services similar to those provided in the familiar mainframe/terminal world.
+</para>
+<para>
+<!-- .LP -->
+Displays may be turned off by the user at any time. Any existing session
+running on a display that has been turned off must be identifiable. This
+is made possible by requiring a three-way handshake to start a session. If
+the handshake succeeds, any existing session is terminated immediately and a
+new session started. There is the problem (at least with TCP) that
+connections may not be closed when the display is turned off. In most
+environments, the manager should reduce this problem by periodically XSync'ing
+on its own connection, perhaps every five to ten minutes, and terminating the
+session if its own connection ever closes.
+</para>
+<para>
+<!-- .LP -->
+Displays should not be required to retain permanent state for purposes of
+the control protocol. One solution to packets received out of sequence
+would be to use monotonically increasing message identifiers in each message
+to allow both sides to ignore messages that arrive out-of-sequence. For
+this to work, displays would at a minimum have to increment a stable crash
+count each time they are powered on and use that number as part of a
+larger sequence number. But if displays cannot retain permanent state this
+cannot work. Instead, the manager assumes the responsibility for permanent
+state by generating unique numbers that identify a particular session and
+the protocol simply ignores packets that correspond to an invalid session.
+</para>
+<para>
+<!-- .LP -->
+The Manager must not be responsible for packet reception. To prevent the
+Manager from becoming stuck because of a hostile display, no portion of the
+protocol requires the Manager to retransmit a packet. Part of this means
+that any valid packet that the Manager does receive must be
+acknowledged in some way to prevent the display from continuously resending
+packets. The display can keep the protocol running as it will always know
+when the Manager has received (at least one copy of) a packet. On the
+Manager side, this means that any packet may be received more than once (if
+the response was lost) and duplicates must be ignored.
+</para>
+</chapter>
+
+<chapter id="Data_Types">
+<title>Data Types</title>
+<!-- .XS -->
+<!-- (SN Data Types -->
+<!-- .XE -->
+<para>
+<!-- .LP -->
+XDMCP packets contain several types of data. Integer values are always
+stored most significant byte first in the packet ("Big Endian" order).
+As XDMCP will not be used to transport large quantities of data, this
+restriction will not substantially hamper the efficiency of any
+implementation. Also, no padding of any sort will occur within the packets.
+</para>
+
+<informaltable frame="none">
+ <tgroup cols='3' align='left'>
+ <colspec colname='c1' colsep="0"/>
+ <colspec colname='c2' colsep="0"/>
+ <colspec colname='c3' colsep="0"/>
+ <thead>
+ <row>
+ <entry>Type Name</entry>
+ <entry>Length (Bytes)</entry>
+ <entry>Description</entry>
+ </row>
+ </thead>
+ <tbody>
+ <row rowsep="0">
+ <entry>CARD8</entry>
+ <entry>1</entry>
+ <entry>A single byte unsigned integer</entry>
+ </row>
+ <row rowsep="0">
+ <entry>CARD16</entry>
+ <entry>2</entry>
+ <entry>Two byte unsigned integer</entry>
+ </row>
+ <row rowsep="0">
+ <entry>CARD32</entry>
+ <entry>4</entry>
+ <entry>Four byte unsigned integer</entry>
+ </row>
+ <row rowsep="0">
+ <entry>ARRAY8</entry>
+ <entry>n+2</entry>
+ <entry>
+This is actually a CARD16 followed by
+a collection of CARD8. The value of the CARD16
+field (n) specifies the number of CARD8 values to follow
+ </entry>
+ </row>
+ <row rowsep="0">
+ <entry>ARRAY16</entry>
+ <entry>2*m+1</entry>
+ <entry>
+This is a CARD8 (m) which specifies the
+number of CARD16 values to follow
+ </entry>
+ </row>
+ <row rowsep="0">
+ <entry>ARRAY32</entry>
+ <entry>4*l+1</entry>
+ <entry>
+This is a CARD8 (l) which specifies the
+number of CARD32 values to follow
+ </entry>
+ </row>
+ <row rowsep="0">
+ <entry>ARRAYofARRAY8</entry>
+ <entry>?</entry>
+ <entry>
+This is a CARD8 which specifies the
+number of ARRAY8 values to follow.
+ </entry>
+ </row>
+ </tbody>
+ </tgroup>
+</informaltable>
+</chapter>
+
+<chapter id="Packet_Format">
+<title>Packet Format</title>
+<!-- .XS -->
+<!-- (SN Packet Format -->
+<!-- .XE -->
+<para>
+All XDMCP packets have the following information:
+</para>
+
+<informaltable frame="none">
+ <tgroup cols='3' align='left'>
+ <colspec colname='c1' colsep="0"/>
+ <colspec colname='c2' colsep="0"/>
+ <colspec colname='c3' colsep="0"/>
+ <thead>
+ <row>
+ <entry>Length (Bytes)</entry>
+ <entry>Field Type</entry>
+ <entry>Description</entry>
+ </row>
+ </thead>
+ <tbody>
+ <row rowsep="0">
+ <entry>2</entry>
+ <entry>CARD16</entry>
+ <entry>version number</entry>
+ </row>
+ <row rowsep="0">
+ <entry>2</entry>
+ <entry>CARD16</entry>
+ <entry>opcode packet header</entry>
+ </row>
+ <row rowsep="0">
+ <entry>2</entry>
+ <entry>CARD16</entry>
+ <entry>n = length of remaining data in bytes</entry>
+ </row>
+ <row rowsep="0">
+ <entry>n</entry>
+ <entry>???</entry>
+ <entry>packet-specific data</entry>
+ </row>
+ </tbody>
+ </tgroup>
+</informaltable>
+
+<para>
+<!-- .LP -->
+The fields are as follows:
+</para>
+
+<variablelist>
+ <varlistentry>
+ <term>Version number</term>
+ <listitem>
+ <para>
+This specifies the version of XDMCP that generated this packet in
+case changes in this protocol are required. Displays and
+managers may choose to support older versions for compatibility.
+This field will initially be one (1).
+ </para>
+ </listitem>
+ </varlistentry>
+ <varlistentry>
+ <term>Opcode</term>
+ <listitem>
+ <para>
+This specifies what step of the protocol this packet represents and should
+contain one of the following values (encoding provided in section below):
+<emphasis role="bold">BroadcastQuery</emphasis>,
+<emphasis role="bold">Query</emphasis>,
+<emphasis role="bold">IndirectQuery</emphasis>,
+<emphasis role="bold">ForwardQuery</emphasis>,
+<emphasis role="bold">Willing</emphasis>,
+<emphasis role="bold">Unwilling</emphasis>,
+<emphasis role="bold">Request</emphasis>,
+<emphasis role="bold">Accept</emphasis>,
+<emphasis role="bold">Decline</emphasis>,
+<emphasis role="bold">Manage</emphasis>,
+<emphasis role="bold">Refuse</emphasis>,
+<emphasis role="bold">Failed</emphasis>,
+<emphasis role="bold">KeepAlive</emphasis>
+or
+<emphasis role="bold">Alive</emphasis>.
+ </para>
+ </listitem>
+ </varlistentry>
+ <varlistentry>
+ <term>Length of data in bytes</term>
+ <listitem>
+ <para>
+This specifies the length of the information following the first 6 bytes.
+Each packet-type has a different format and will need to be separately
+length-checked against this value. Because every data item has either an
+explicit or implicit length, this can be easily accomplished.
+Packets that have too little or too much data should be ignored.
+ </para>
+ </listitem>
+ </varlistentry>
+</variablelist>
+<para>
+Packets should be checked to make sure that they satisfy the following
+conditions:
+</para>
+
+<orderedlist>
+ <listitem>
+ <para>
+They must contain valid opcodes.
+ </para>
+ </listitem>
+ <listitem>
+ <para>
+The length of the remaining data should correspond to the sum of the
+lengths of the individual remaining data items.
+ </para>
+ </listitem>
+ <listitem>
+ <para>
+The opcode should be expected (a finite state diagram is given
+in a later section).
+ </para>
+ </listitem>
+ <listitem>
+ <para>
+If the packet is of type
+<emphasis role="bold">Manage</emphasis> or
+<emphasis role="bold">Refuse</emphasis>,
+the Session ID should match the value sent in the preceding
+<emphasis role="bold">Accept</emphasis> packet.
+ </para>
+ </listitem>
+</orderedlist>
+</chapter>
+
+<chapter id="Protocol">
+<title>Protocol</title>
+<!-- .XS -->
+<!-- (SN Protocol -->
+<!-- .XE -->
+<para>
+Each of the opcodes is described below. Because a given packet type is only
+ever sent one way, each packet description below indicates the direction.
+Most of the packets have additional information included beyond the
+description above. The additional information is appended to the packet
+header in the order described without padding, and the length field is
+computed accordingly.
+</para>
+
+<informaltable frame="none">
+ <tgroup cols='10' align='left'>
+ <colspec colname='col1' colsep="0" colwidth="1*"/>
+ <colspec colname='col2' colsep="0" colwidth="1*"/>
+ <colspec colname='col3' colsep="0" colwidth="1*"/>
+ <colspec colname='col4' colsep="0" colwidth="1*"/>
+ <colspec colname='col5' colsep="0" colwidth="1*"/>
+ <colspec colname='col6' colsep="0" colwidth="1*"/>
+ <colspec colname='col7' colsep="0" colwidth="1*"/>
+ <colspec colname='col8' colsep="0" colwidth="1*"/>
+ <colspec colname='col9' colsep="0" colwidth="1*"/>
+ <colspec colname='col10' colsep="0" colwidth="1*"/>
+ <spanspec namest="col1" nameend="col10" spanname="col1_on" align="left"/>
+ <spanspec namest="col2" nameend="col10" spanname="col2_on" align="left"/>
+ <spanspec namest="col3" nameend="col10" spanname="col3_on" align="left"/>
+ <spanspec namest="col4" nameend="col10" spanname="col4_on" align="left"/>
+ <spanspec namest="col5" nameend="col10" spanname="col5_on" align="left"/>
+ <tbody>
+ <row rowsep="0">
+ <entry spanname="col1_on"><emphasis role="bold">Query</emphasis></entry>
+ </row>
+ <row rowsep="0">
+ <entry spanname="col1_on"><emphasis role="bold">BroadcastQuery</emphasis></entry>
+ </row>
+ <row rowsep="0">
+ <entry spanname="col1_on"><emphasis role="bold">IndirectQuery</emphasis></entry>
+ </row>
+ <row rowsep="0">
+ <entry></entry>
+ <entry spanname="col2_on">Display -> Manager</entry>
+ </row>
+ <row rowsep="0">
+ <entry></entry>
+ <entry spanname="col2_on">Additional Fields:</entry>
+ </row>
+ <row rowsep="0">
+ <entry></entry>
+ <entry></entry>
+ <entry spanname="col3_on">
+<emphasis>Authentication Names</emphasis>: ARRAYofARRAY8
+ </entry>
+ </row>
+ <row rowsep="0">
+ <entry></entry>
+ <entry></entry>
+ <entry></entry>
+ <entry spanname="col4_on">
+Specifies a list of authentication names that the display supports. The
+manager will choose one of these and return it in the
+<emphasis role="bold">Willing</emphasis> packet.
+ </entry>
+ </row>
+<!-- AAAAAAAAAAAAA -->
+ <row rowsep="0">
+ <entry></entry>
+ <entry></entry>
+ <entry>Semantics</entry>
+ </row>
+ <row rowsep="0">
+ <entry></entry>
+ <entry></entry>
+ <entry></entry>
+ <entry spanname="col4_on">
+<para>
+A <function>Query</function>
+packet is sent from the display to a specific host to ask if
+that host is willing to provide management services to this display. The
+host should respond with
+<function>Willing</function>
+if it is willing to service the display or
+<function>Unwilling</function>
+if it is not.
+</para>
+
+<para>
+A
+<function>BroadcastQuery</function>
+packet is similar to the
+<function>Query</function>
+packet except that it is intended to be received by all hosts on the network
+(or subnetwork). However, unlike
+<function>Query</function>
+requests, hosts that are not willing to service the display
+should simply ignore
+<function>BroadcastQuery</function>
+requests.
+</para>
+
+<para>
+An
+<function>IndirectQuery</function>
+packet is sent to a well known manager that forwards
+the request to a larger collection of secondary managers using
+<function>ForwardQuery</function>
+packets.
+In this way, the collection of managers that respond can be grouped
+on other than network boundaries; the use of a central manager reduces
+system administrative overhead.
+The primary manager may also send a
+<function>Willing</function>
+packet in response to this packet.
+</para>
+
+<para>
+Each packet type has slightly different semantics:
+</para>
+ </entry>
+ </row>
+ <row rowsep="0">
+ <entry></entry>
+ <entry></entry>
+ <entry></entry>
+ <entry></entry>
+ <entry spanname="col5_on">
+<para>
+The
+<function>Query</function>
+packet is destined only for a single host.
+If the display is instructed to
+<function>Query</function>
+multiple managers, it will send multiple
+<function>Query</function>
+packets. The
+<function>Query</function>
+packet also demands a response from the manager, either
+<function>Willing</function>
+or
+<function>Unwilling</function>.
+ </para>
+ <para>
+The
+<function>BroadcastQuery</function>
+packet is sent to many hosts.
+Each manager that receives this packet will not respond with an
+<function>Unwilling</function>
+packet.
+ </para>
+ <para>
+The
+<function>IndirectQuery</function>
+packet is sent to only one manager with the request
+that the request be forwarded to a larger list of managers using
+<function>ForwardQuery</function>
+packets. This list is expected to be maintained at one
+central site to reduce administrative overhead.
+The function of this packet type is similar to
+<function>BroadcastQuery except that</function>
+<function>BroadcastQuery</function>
+is not forwarded.
+ </para>
+ </entry>
+ </row>
+ <row rowsep="0">
+ <entry></entry>
+ <entry></entry>
+ <entry></entry>
+ <entry spanname="col4_on">Valid Responses:</entry>
+ </row>
+ <row rowsep="0">
+ <entry></entry>
+ <entry></entry>
+ <entry spanname="col3_on">
+<function>Willing</function>,
+<function>Unwilling</function>
+ </entry>
+ </row>
+ <row rowsep="0">
+ <entry></entry>
+ <entry></entry>
+ <entry></entry>
+ <entry spanname="col4_on">Problems/Solutions:</entry>
+ </row>
+ <row rowsep="0">
+ <entry></entry>
+ <entry></entry>
+ <entry spanname="col3_on">Problem:</entry>
+ </row>
+ <row rowsep="0">
+ <entry></entry>
+ <entry></entry>
+ <entry></entry>
+ <entry spanname="col4_on">
+<para>Not all managers receive the query packet.</para>
+<para>Indication:</para>
+ </entry>
+ </row>
+ <row rowsep="0">
+ <entry></entry>
+ <entry></entry>
+ <entry></entry>
+ <entry></entry>
+ <entry spanname="col5_on">
+None if
+<function>BroadcastQuery</function>
+or
+<function>IndirectQuery</function>
+was sent, else failure to receive
+<function>Willing</function>.
+ </entry>
+ </row>
+ <row rowsep="0">
+ <entry></entry>
+ <entry></entry>
+ <entry></entry>
+ <entry spanname="col4_on">Solution:</entry>
+ </row>
+ <row rowsep="0">
+ <entry></entry>
+ <entry></entry>
+ <entry></entry>
+ <entry></entry>
+ <entry spanname="col5_on">
+Repeatedly send the packet while waiting for user to choose a manager.
+ </entry>
+ </row>
+ <row rowsep="0">
+ <entry></entry>
+ <entry></entry>
+ <entry spanname="col3_on">
+Timeout/Retransmission policy:
+ </entry>
+ </row>
+ <row rowsep="0">
+ <entry></entry>
+ <entry></entry>
+ <entry></entry>
+ <entry spanname="col4_on">
+An exponential backoff algorithm should be used here to reduce network load
+for long-standing idle displays. Start at 2 seconds, back off by factors of
+2 to 32 seconds, and discontinue retransmit after 126 seconds. The display
+should reset the timeout when user-input is detected. In this way, the
+display will wakeup when touched by the user.
+ </entry>
+ </row>
+ <row rowsep="0">
+ <entry spanname="col1_on">
+<function>ForwardQuery</function>
+ </entry>
+ </row>
+ <row rowsep="0">
+ <entry></entry>
+ <entry spanname="col2_on">
+<para>Primary Manager -&gt; Secondary Manager</para>
+<para>Additional Fields:</para>
+ </entry>
+ </row>
+ <row rowsep="0">
+ <entry></entry>
+ <entry></entry>
+ <entry spanname="col3_on">
+<emphasis remap='I'>Client Address</emphasis>: ARRAY8
+ </entry>
+ </row>
+ <row rowsep="0">
+ <entry></entry>
+ <entry></entry>
+ <entry></entry>
+ <entry spanname="col4_on">
+Specifies the network address of the client display.
+ </entry>
+ </row>
+ <row rowsep="0">
+ <entry></entry>
+ <entry></entry>
+ <entry spanname="col3_on">
+<emphasis remap='I'>Client Port</emphasis>: ARRAY8
+ </entry>
+ </row>
+ <row rowsep="0">
+ <entry></entry>
+ <entry></entry>
+ <entry></entry>
+ <entry spanname="col4_on">
+Specifies an identification of the client task on the client display.
+ </entry>
+ </row>
+ <row rowsep="0">
+ <entry></entry>
+ <entry></entry>
+ <entry spanname="col3_on">
+<emphasis remap='I'>Authentication Names</emphasis>: ARRAYofARRAY8
+ </entry>
+ </row>
+ <row rowsep="0">
+ <entry></entry>
+ <entry></entry>
+ <entry></entry>
+ <entry spanname="col4_on">
+Is a duplicate of Authentication Names array that was received
+in the
+<function>IndirectQuery</function>
+packet.
+ </entry>
+ </row>
+ <row rowsep="0">
+ <entry></entry>
+ <entry spanname="col2_on">
+Semantics:
+ </entry>
+ </row>
+ <row rowsep="0">
+ <entry></entry>
+ <entry></entry>
+ <entry spanname="col3_on">
+ <para>
+When primary manager receives a
+<function>IndirectQuery</function>
+packet, it is responsible for sending
+<function>ForwardQuery</function>
+packets to an appropriate list of
+managers that can provide service to the display using the same network
+type as the one the original
+<function>IndirectQuery</function>
+packet was received from.
+The Client Address and Client Port fields must contain an
+address that the secondary manager can use to reach the display also using
+this same network. Each secondary manager sends a
+<function>Willing</function>
+packet to the display if it is willing to provide service.
+ </para>
+
+ <para>
+<function>ForwardQuery</function>
+packets are similar to
+<function>BroadcastQuery</function>
+packets in that managers that are not willing to service
+particular displays should not send a
+<function>Unwilling</function>
+packet.
+ </para>
+ </entry>
+ </row>
+ <row rowsep="0">
+ <entry></entry>
+ <entry spanname="col2_on">
+Valid Responses:
+ </entry>
+ </row>
+
+ <row rowsep="0">
+ <entry></entry>
+ <entry></entry>
+ <entry spanname="col3_on">
+<function>Willing</function>
+ </entry>
+ </row>
+ <row rowsep="0">
+ <entry></entry>
+ <entry spanname="col2_on">
+Problems/Solutions:
+ </entry>
+ </row>
+ <row rowsep="0">
+ <entry></entry>
+ <entry></entry>
+ <entry spanname="col3_on">
+Identical to
+<function>BroadcastQuery</function>
+ </entry>
+ </row>
+ <row rowsep="0">
+ <entry></entry>
+ <entry spanname="col2_on">
+Timeout/Retransmission policy:
+ </entry>
+ </row>
+ <row rowsep="0">
+ <entry></entry>
+ <entry></entry>
+ <entry spanname="col3_on">
+Like all packets sent from a manager, this packet should never be
+retransmitted.
+ </entry>
+ </row>
+
+ <row rowsep="0">
+ <entry spanname="col1_on">
+<function>Willing</function>
+ </entry>
+ </row>
+
+ <row rowsep="0">
+ <entry></entry>
+ <entry spanname="col2_on">
+ <para>
+Manager -&gt; Display
+ </para>
+ <para>
+Additional Fields:
+ </para>
+ </entry>
+ </row>
+
+ <row rowsep="0">
+ <entry></entry>
+ <entry></entry>
+ <entry spanname="col3_on">
+<emphasis remap='I'>Authentication Name</emphasis>: ARRAY8
+ </entry>
+ </row>
+
+ <row rowsep="0">
+ <entry></entry>
+ <entry></entry>
+ <entry></entry>
+ <entry spanname="col4_on">
+<para>
+Specifies the authentication method, selected from the list offered in the
+<function>Query ,</function>
+<function>BroadcastQuery ,</function>
+or
+<function>IndirectQuery</function>
+packet that the manger expects the display to use in the subsequent
+<function>Request</function>
+packet.
+This choice should remain as constant as feasible so that displays that
+send multiple
+<function>Query</function>
+packets can use the Authentication Name from any
+<function>Willing</function>
+packet that arrives.
+</para>
+<para>
+The display is free to ignore managers that request an insufficient level
+of authentication.
+</para>
+ </entry>
+ </row>
+
+ <row rowsep="0">
+ <entry></entry>
+ <entry></entry>
+ <entry spanname="col3_on">
+<emphasis remap='I'>Hostname</emphasis>: ARRAY8
+ </entry>
+ </row>
+
+ <row rowsep="0">
+ <entry></entry>
+ <entry></entry>
+ <entry></entry>
+ <entry spanname="col4_on">
+Is a human readable string describing the host from which the packet was sent.
+The protocol specifies no interpretation of the data in this field.
+ </entry>
+ </row>
+
+ <row rowsep="0">
+ <entry></entry>
+ <entry></entry>
+ <entry spanname="col3_on">
+<emphasis remap='I'>Status</emphasis>: ARRAY8
+ </entry>
+ </row>
+
+ <row rowsep="0">
+ <entry></entry>
+ <entry></entry>
+ <entry></entry>
+ <entry spanname="col4_on">
+Is a human readable string describing the status of the host. This could
+include load average/number of users connected or other information. The
+protocol specifies no interpretation of the data in this field.
+ </entry>
+ </row>
+
+
+ <row rowsep="0">
+ <entry></entry>
+ <entry spanname="col2_on">
+Semantics:
+ </entry>
+ </row>
+
+ <row rowsep="0">
+ <entry></entry>
+ <entry></entry>
+ <entry spanname="col3_on">
+A
+<function>Willing</function>
+packet is sent by managers that may service connections from
+this display. It is sent in response to either a
+<function>Query ,</function>
+<function>BroadcastQuery ,</function>
+or
+<function>ForwardQuery</function>
+but does not imply a commitment to provide service
+(for example, it may later decide that it has accepted enough
+connections already).
+ </entry>
+ </row>
+
+ <row rowsep="0">
+ <entry></entry>
+ <entry spanname="col2_on">
+Problems/Solutions:
+ </entry>
+ </row>
+
+ <row rowsep="0">
+ <entry></entry>
+ <entry></entry>
+ <entry spanname="col3_on">
+Problem:
+ </entry>
+ </row>
+
+ <row rowsep="0">
+ <entry></entry>
+ <entry></entry>
+ <entry></entry>
+ <entry spanname="col4_on">
+<para>
+<function>Willing</function>
+not received by the display.
+</para>
+<para>
+Indication:
+</para>
+ </entry>
+ </row>
+
+ <row rowsep="0">
+ <entry></entry>
+ <entry></entry>
+ <entry></entry>
+ <entry></entry>
+ <entry spanname="col5_on">
+None if
+<function>BroadcastQuery</function>
+or
+<function>IndirectQuery</function>
+was sent, else failure to receive
+<function>Willing .</function>
+ </entry>
+ </row>
+
+ <row rowsep="0">
+ <entry></entry>
+ <entry></entry>
+ <entry></entry>
+ <entry spanname="col4_on">
+Solution:
+ </entry>
+ </row>
+
+ <row rowsep="0">
+ <entry></entry>
+ <entry></entry>
+ <entry></entry>
+ <entry></entry>
+ <entry spanname="col5_on">
+The display should continue to send the query until a response is received.
+ </entry>
+ </row>
+
+
+
+ <row rowsep="0">
+ <entry></entry>
+ <entry spanname="col2_on">
+Timeout/Retransmission policy:
+ </entry>
+ </row>
+
+ <row rowsep="0">
+ <entry></entry>
+ <entry></entry>
+ <entry spanname="col3_on">
+Like all packets sent from the manager to the display, this packet should
+never be retransmitted.
+ </entry>
+ </row>
+
+ <row rowsep="0">
+ <entry spanname="col1_on">
+<function>Unwilling</function>
+ </entry>
+ </row>
+
+ <row rowsep="0">
+ <entry></entry>
+ <entry spanname="col2_on">
+ <para>
+Manager -&gt; Display
+ </para>
+ <para>
+Additional Fields:
+ </para>
+ </entry>
+ </row>
+
+ <row rowsep="0">
+ <entry></entry>
+ <entry></entry>
+ <entry spanname="col3_on">
+The Hostname and Status fields as in the
+<function>Willing</function>
+packet.
+The Status field should indicate to the user a reason
+for the refusal of service.
+ </entry>
+ </row>
+
+ <row rowsep="0">
+ <entry></entry>
+ <entry spanname="col2_on">
+Semantics:
+ </entry>
+ </row>
+
+ <row rowsep="0">
+ <entry></entry>
+ <entry></entry>
+ <entry spanname="col3_on">
+An
+<function>Unwilling</function>
+packet is sent by managers in response to direct
+<function>Query</function>
+requests (as opposed to
+<function>BroadcastQuery</function>
+or
+<function>IndirectQuery</function>
+requests) if the manager will not accept requests for management.
+This is typically sent by managers that wish to only service
+particular displays or that handle a limited number of displays at once.
+ </entry>
+ </row>
+
+ <row rowsep="0">
+ <entry></entry>
+ <entry spanname="col2_on">
+Problems/Solutions:
+ </entry>
+ </row>
+
+ <row rowsep="0">
+ <entry></entry>
+ <entry></entry>
+ <entry spanname="col3_on">
+Problem:
+ </entry>
+ </row>
+
+ <row rowsep="0">
+ <entry></entry>
+ <entry></entry>
+ <entry></entry>
+ <entry spanname="col4_on">
+<para>
+<function>Unwilling</function>
+not received by the display.
+</para>
+<para>
+Indication:
+</para>
+ </entry>
+ </row>
+
+ <row rowsep="0">
+ <entry></entry>
+ <entry></entry>
+ <entry></entry>
+ <entry></entry>
+ <entry spanname="col5_on">
+Display fails to receive
+<function>Unwilling .</function>
+ </entry>
+ </row>
+
+ <row rowsep="0">
+ <entry></entry>
+ <entry></entry>
+ <entry></entry>
+ <entry spanname="col4_on">
+Solution:
+ </entry>
+ </row>
+
+ <row rowsep="0">
+ <entry></entry>
+ <entry></entry>
+ <entry></entry>
+ <entry></entry>
+ <entry spanname="col5_on">
+The display should continue to send
+<function>Query</function>
+messages until a response is received.
+ </entry>
+ </row>
+
+ <row rowsep="0">
+ <entry></entry>
+ <entry spanname="col2_on">
+Timeout/Retransmission policy:
+ </entry>
+ </row>
+
+ <row rowsep="0">
+ <entry></entry>
+ <entry></entry>
+ <entry spanname="col3_on">
+Like all packets sent from the manager to the display, this packet should
+never be retransmitted.
+ </entry>
+ </row>
+ <row rowsep="0">
+ <entry spanname="col1_on">
+<function>Request</function>
+ </entry>
+ </row>
+
+ <row rowsep="0">
+ <entry></entry>
+ <entry spanname="col2_on">
+ <para>
+Display -&gt; Manager
+ </para>
+ <para>
+Additional Fields:
+ </para>
+ </entry>
+ </row>
+
+ <row rowsep="0">
+ <entry></entry>
+ <entry></entry>
+ <entry spanname="col3_on">
+<emphasis remap='I'>Display Number</emphasis>: CARD16
+ </entry>
+ </row>
+
+ <row rowsep="0">
+ <entry></entry>
+ <entry></entry>
+ <entry></entry>
+ <entry spanname="col4_on">
+Specifies the index of this particular server for the host
+on which the display is resident.
+This value will be zero for most autonomous displays.
+ </entry>
+ </row>
+
+ <row rowsep="0">
+ <entry></entry>
+ <entry></entry>
+ <entry spanname="col3_on">
+<emphasis remap='I'>Connection Types</emphasis>: ARRAY16
+ </entry>
+ </row>
+
+ <row rowsep="0">
+ <entry></entry>
+ <entry></entry>
+ <entry></entry>
+ <entry spanname="col4_on">
+Specifies an array indicating the stream services accepted by the display.
+If the high-order byte in a particular entry is zero, the low-order byte
+corresponds to an X-protocol host family type.
+ </entry>
+ </row>
+
+ <row rowsep="0">
+ <entry></entry>
+ <entry></entry>
+ <entry spanname="col3_on">
+<emphasis remap='I'>Connection Addresses</emphasis>: ARRAYofARRAY8
+ </entry>
+ </row>
+
+ <row rowsep="0">
+ <entry></entry>
+ <entry></entry>
+ <entry></entry>
+ <entry spanname="col4_on">
+For each connection type in the previous array, the corresponding entry in
+this array indicates the network address of the display device.
+ </entry>
+ </row>
+
+ <row rowsep="0">
+ <entry></entry>
+ <entry></entry>
+ <entry spanname="col3_on">
+ <para>
+<emphasis remap='I'>Authentication Name</emphasis>: ARRAY8
+ </para>
+ <para>
+<emphasis remap='I'>Authentication Data</emphasis>: ARRAY8
+ </para>
+ </entry>
+ </row>
+
+ <row rowsep="0">
+ <entry></entry>
+ <entry></entry>
+ <entry></entry>
+ <entry spanname="col4_on">
+Specifies the authentication protocol that the display expects
+the manager to validate itself with. The Authentication Data is
+expected to contain data that the manager will interpret, modify
+and use to authenticate itself.
+ </entry>
+ </row>
+
+ <row rowsep="0">
+ <entry></entry>
+ <entry></entry>
+ <entry spanname="col3_on">
+<emphasis remap='I'>Authorization Names</emphasis>: ARRAYofARRAY8
+ </entry>
+ </row>
+
+ <row rowsep="0">
+ <entry></entry>
+ <entry></entry>
+ <entry></entry>
+ <entry spanname="col4_on">
+Specifies which types of authorization the display supports. The
+manager may decide to reject displays with which it cannot perform
+authorization.
+ </entry>
+ </row>
+
+ <row rowsep="0">
+ <entry></entry>
+ <entry></entry>
+ <entry spanname="col3_on">
+<emphasis remap='I'>Manufacturer Display ID</emphasis>: ARRAY8
+ </entry>
+ </row>
+
+ <row rowsep="0">
+ <entry></entry>
+ <entry></entry>
+ <entry></entry>
+ <entry spanname="col4_on">
+Can be used by the manager to determine how to decrypt the
+Authentication Data field in this packet. See the section below on
+Manufacturer Display ID Format.
+ </entry>
+ </row>
+
+ <row rowsep="0">
+ <entry></entry>
+ <entry spanname="col2_on">
+Semantics:
+ </entry>
+ </row>
+
+ <row rowsep="0">
+ <entry></entry>
+ <entry></entry>
+ <entry spanname="col3_on">
+A
+<function>Request</function>
+packet is sent by a display to a specific host to request a
+session ID in preparation for a establishing a connection. If the manager
+is willing to service a connection to this display, it should return an
+<function>Accept</function>
+packet with a valid session ID and should be ready for a subsequent
+<function>Manage</function>
+request. Otherwise, it should return a
+<function>Decline</function>
+packet.
+ </entry>
+ </row>
+
+ <row rowsep="0">
+ <entry></entry>
+ <entry spanname="col2_on">
+Valid Responses:
+ </entry>
+ </row>
+
+ <row rowsep="0">
+ <entry></entry>
+ <entry></entry>
+ <entry spanname="col3_on">
+<function>Accept ,</function>
+<function>Decline</function>
+ </entry>
+ </row>
+
+ <row rowsep="0">
+ <entry></entry>
+ <entry spanname="col2_on">
+Problems/Solutions:
+ </entry>
+ </row>
+
+ <row rowsep="0">
+ <entry></entry>
+ <entry></entry>
+ <entry spanname="col3_on">
+Problem:
+ </entry>
+ </row>
+
+ <row rowsep="0">
+ <entry></entry>
+ <entry></entry>
+ <entry></entry>
+ <entry spanname="col4_on">
+Request not received by manager.
+ </entry>
+ </row>
+
+ <row rowsep="0">
+ <entry></entry>
+ <entry></entry>
+ <entry></entry>
+ <entry spanname="col4_on">
+Indication:
+ </entry>
+ </row>
+
+ <row rowsep="0">
+ <entry></entry>
+ <entry></entry>
+ <entry></entry>
+ <entry></entry>
+ <entry spanname="col5_on">
+Display timeout waiting for response.
+ </entry>
+ </row>
+
+ <row rowsep="0">
+ <entry></entry>
+ <entry></entry>
+ <entry></entry>
+ <entry spanname="col4_on">
+Solution:
+ </entry>
+ </row>
+
+ <row rowsep="0">
+ <entry></entry>
+ <entry></entry>
+ <entry></entry>
+ <entry></entry>
+ <entry spanname="col5_on">
+Display resends
+<function>Request</function>
+message.
+ </entry>
+ </row>
+
+
+ <row rowsep="0">
+ <entry></entry>
+ <entry></entry>
+ <entry></entry>
+ <entry spanname="col4_on">
+Problem:
+ </entry>
+ </row>
+
+ <row rowsep="0">
+ <entry></entry>
+ <entry></entry>
+ <entry></entry>
+ <entry></entry>
+ <entry spanname="col5_on">
+Message received out of order by manager.
+ </entry>
+ </row>
+
+ <row rowsep="0">
+ <entry></entry>
+ <entry></entry>
+ <entry></entry>
+ <entry spanname="col4_on">
+Indication:
+ </entry>
+ </row>
+
+ <row rowsep="0">
+ <entry></entry>
+ <entry></entry>
+ <entry></entry>
+ <entry></entry>
+ <entry spanname="col5_on">
+None.
+ </entry>
+ </row>
+
+ <row rowsep="0">
+ <entry></entry>
+ <entry></entry>
+ <entry></entry>
+ <entry spanname="col4_on">
+Solution:
+ </entry>
+ </row>
+
+ <row rowsep="0">
+ <entry></entry>
+ <entry></entry>
+ <entry></entry>
+ <entry></entry>
+ <entry spanname="col5_on">
+Each time a
+<function>Request</function>
+is sent, the manager sends the Session ID
+associated with the next session in the
+<function>Accept .</function>
+If that next session is not yet started,
+the manager will simply resend with the same Session ID.
+If the session is in progress, the manager will reply
+with a new Session ID; in which case, the
+<function>Accept</function>
+will be discarded by the display.
+ </entry>
+ </row>
+
+ <row rowsep="0">
+ <entry></entry>
+ <entry spanname="col2_on">
+Timeout/Retransmission policy:
+ </entry>
+ </row>
+
+ <row rowsep="0">
+ <entry></entry>
+ <entry></entry>
+ <entry spanname="col3_on">
+Timeout after 2 seconds, exponential backoff to 32 seconds.
+After no more than 126 seconds, give up and report an error to the user.
+ </entry>
+ </row>
+
+ <row rowsep="0">
+ <entry spanname="col1_on">
+<function>Accept</function>
+ </entry>
+ </row>
+
+ <row rowsep="0">
+ <entry></entry>
+ <entry spanname="col2_on">
+ <para>
+Manager -&gt; Display
+ </para>
+ <para>
+Additional Fields:
+ </para>
+ </entry>
+ </row>
+
+ <row rowsep="0">
+ <entry></entry>
+ <entry></entry>
+ <entry spanname="col3_on">
+<emphasis remap='I'>Session ID</emphasis>: CARD32
+ </entry>
+ </row>
+
+ <row rowsep="0">
+ <entry></entry>
+ <entry></entry>
+ <entry></entry>
+ <entry spanname="col4_on">
+Identifies the session that can be started by the manager.
+ </entry>
+ </row>
+
+ <row rowsep="0">
+ <entry></entry>
+ <entry></entry>
+ <entry spanname="col3_on">
+ <para>
+<emphasis remap='I'>Authentication Name</emphasis>: ARRAY8
+ </para>
+ <para>
+<emphasis remap='I'>Authentication Data</emphasis>: ARRAY8
+ </para>
+ </entry>
+ </row>
+
+ <row rowsep="0">
+ <entry></entry>
+ <entry></entry>
+ <entry></entry>
+ <entry spanname="col4_on">
+Is the data sent back to the display to authenticate the manager.
+If the Authentication Data is not the value expected by the display, it
+should terminate the protocol at this point and display an error to the user.
+ </entry>
+ </row>
+
+ <row rowsep="0">
+ <entry></entry>
+ <entry></entry>
+ <entry spanname="col3_on">
+ <para>
+<emphasis remap='I'>Authorization Name</emphasis>: ARRAY8
+ </para>
+ <para>
+<emphasis remap='I'>Authorization Data</emphasis>: ARRAY8
+ </para>
+ </entry>
+ </row>
+
+ <row rowsep="0">
+ <entry></entry>
+ <entry></entry>
+ <entry></entry>
+ <entry spanname="col4_on">
+Is the data sent to the display to indicate the type of authorization the
+manager will be using in the first call to
+<function>XOpenDisplay</function>
+after the
+<function>Manage</function>
+packet is received.
+ </entry>
+ </row>
+
+
+ <row rowsep="0">
+ <entry></entry>
+ <entry spanname="col2_on">
+Semantics:
+ </entry>
+ </row>
+
+ <row rowsep="0">
+ <entry></entry>
+ <entry></entry>
+ <entry spanname="col3_on">
+<para>
+An
+<function>Accept</function>
+packet is sent by a manager in response to a
+<function>Request</function>
+packet if the manager is willing to establish a connection for the display.
+The Session ID is used to identify this connection from any preceding
+ones and will be used by the display in its subsequent
+<function>Manage</function>
+packet.
+The Session ID is a 32-bit number that is incremented each time an
+<function>Accept</function>
+packet is sent as it must be unique over a reasonably long period of time.
+</para>
+<para>
+If the authentication information is invalid, a
+<function>Decline</function>
+packet will be returned with an appropriate
+<function>Status</function>
+message.
+</para>
+ </entry>
+ </row>
+
+ <row rowsep="0">
+ <entry></entry>
+ <entry spanname="col2_on">
+Problems/Solutions:
+ </entry>
+ </row>
+
+ <row rowsep="0">
+ <entry></entry>
+ <entry></entry>
+ <entry spanname="col3_on">
+Problem:
+ </entry>
+ </row>
+
+ <row rowsep="0">
+ <entry></entry>
+ <entry></entry>
+ <entry></entry>
+ <entry spanname="col4_on">
+<function>Accept</function>
+or
+<function>Decline</function>
+not received by display.
+ </entry>
+ </row>
+
+ <row rowsep="0">
+ <entry></entry>
+ <entry></entry>
+ <entry></entry>
+ <entry spanname="col4_on">
+Indication:
+ </entry>
+ </row>
+
+ <row rowsep="0">
+ <entry></entry>
+ <entry></entry>
+ <entry></entry>
+ <entry></entry>
+ <entry spanname="col5_on">
+Display timeout waiting for response to
+<function>Request .</function>
+ </entry>
+ </row>
+
+ <row rowsep="0">
+ <entry></entry>
+ <entry></entry>
+ <entry></entry>
+ <entry spanname="col4_on">
+Solution:
+ </entry>
+ </row>
+
+ <row rowsep="0">
+ <entry></entry>
+ <entry></entry>
+ <entry></entry>
+ <entry></entry>
+ <entry spanname="col5_on">
+Display resends
+<function>Request</function>
+message.
+ </entry>
+ </row>
+
+ <row rowsep="0">
+ <entry></entry>
+ <entry></entry>
+ <entry spanname="col3_on">
+Problem:
+ </entry>
+ </row>
+
+ <row rowsep="0">
+ <entry></entry>
+ <entry></entry>
+ <entry></entry>
+ <entry spanname="col4_on">
+Message received out of order by display.
+ </entry>
+ </row>
+
+ <row rowsep="0">
+ <entry></entry>
+ <entry></entry>
+ <entry></entry>
+ <entry spanname="col4_on">
+Indication:
+ </entry>
+ </row>
+
+ <row rowsep="0">
+ <entry></entry>
+ <entry></entry>
+ <entry></entry>
+ <entry></entry>
+ <entry spanname="col5_on">
+Display receives
+<function>Accept</function>
+after
+<function>Manage</function>
+has been sent.
+ </entry>
+ </row>
+
+ <row rowsep="0">
+ <entry></entry>
+ <entry></entry>
+ <entry></entry>
+ <entry spanname="col4_on">
+Solution:
+ </entry>
+ </row>
+
+ <row rowsep="0">
+ <entry></entry>
+ <entry></entry>
+ <entry></entry>
+ <entry></entry>
+ <entry spanname="col5_on">
+Display discards
+<function>Accept</function>
+messages after it has sent a
+<function>Manage</function>
+message.
+ </entry>
+ </row>
+
+ <row rowsep="0">
+ <entry></entry>
+ <entry spanname="col2_on">
+Timeout/Retransmission policy:
+ </entry>
+ </row>
+
+ <row rowsep="0">
+ <entry></entry>
+ <entry></entry>
+ <entry spanname="col3_on">
+Like all packets sent from the manager to the display, this packet should
+never be retransmitted.
+ </entry>
+ </row>
+
+ <row rowsep="0">
+ <entry spanname="col1_on">
+<function>Decline</function>
+ </entry>
+ </row>
+
+ <row rowsep="0">
+ <entry></entry>
+ <entry spanname="col2_on">
+ <para>
+Manager -&gt; Display
+ </para>
+ <para>
+Additional Fields:
+ </para>
+ </entry>
+ </row>
+
+ <row rowsep="0">
+ <entry></entry>
+ <entry></entry>
+ <entry spanname="col3_on">
+<emphasis remap='I'>Status</emphasis>: ARRAY8
+ </entry>
+ </row>
+
+ <row rowsep="0">
+ <entry></entry>
+ <entry></entry>
+ <entry></entry>
+ <entry spanname="col4_on">
+Is a human readable string indicating the reason for refusal of
+service.
+ </entry>
+ </row>
+
+ <row rowsep="0">
+ <entry></entry>
+ <entry></entry>
+ <entry spanname="col3_on">
+ <para>
+<emphasis remap='I'>Authentication Name</emphasis>:
+ARRAY8
+ </para>
+ <para>
+<emphasis remap='I'>Authentication Data</emphasis>:
+ARRAY8
+ </para>
+ </entry>
+ </row>
+
+ <row rowsep="0">
+ <entry></entry>
+ <entry></entry>
+ <entry></entry>
+ <entry spanname="col4_on">
+Is the data sent back to the display to authenticate the manager. If the
+Authentication Data is not the value expected by the display, it
+should terminate the protocol at this point and display an error to the user.
+ </entry>
+ </row>
+
+ <row rowsep="0">
+ <entry></entry>
+ <entry spanname="col2_on">
+Semantics:
+ </entry>
+ </row>
+
+ <row rowsep="0">
+ <entry></entry>
+ <entry></entry>
+ <entry spanname="col3_on">
+A
+<function>Decline</function>
+packet is sent by a manager in response to a
+<function>Request</function>
+packet if the manager is unwilling to establish a connection for the
+display.
+This is allowed even if the manager had responded
+<function>Willing</function>
+to a previous query.
+ </entry>
+ </row>
+
+ <row rowsep="0">
+ <entry></entry>
+ <entry spanname="col2_on">
+Problems/Solutions:
+ </entry>
+ </row>
+
+ <row rowsep="0">
+ <entry></entry>
+ <entry></entry>
+ <entry spanname="col3_on">
+Same as for
+<function>Accept .</function>
+ </entry>
+ </row>
+
+ <row rowsep="0">
+ <entry></entry>
+ <entry spanname="col2_on">
+Timeout/Retransmission policy:
+ </entry>
+ </row>
+
+ <row rowsep="0">
+ <entry></entry>
+ <entry></entry>
+ <entry spanname="col3_on">
+Like all packets sent from a manager to a display, this packet should never
+be retransmitted.
+ </entry>
+ </row>
+
+ <row rowsep="0">
+ <entry spanname="col1_on">
+<function>Manage</function>
+ </entry>
+ </row>
+
+ <row rowsep="0">
+ <entry></entry>
+ <entry spanname="col2_on">
+ <para>
+Display -&gt; Manager
+ </para>
+ <para>
+Additional Fields:
+ </para>
+ </entry>
+ </row>
+
+ <row rowsep="0">
+ <entry></entry>
+ <entry></entry>
+ <entry spanname="col3_on">
+<emphasis remap='I'>Session ID</emphasis>: CARD32
+ </entry>
+ </row>
+
+ <row rowsep="0">
+ <entry></entry>
+ <entry></entry>
+ <entry></entry>
+ <entry spanname="col4_on">
+Should contain the nonzero session ID returned in the
+<function>Accept</function>
+packet.
+ </entry>
+ </row>
+
+ <row rowsep="0">
+ <entry></entry>
+ <entry></entry>
+ <entry spanname="col3_on">
+<emphasis remap='I'>Display Number</emphasis>: CARD16
+ </entry>
+ </row>
+
+ <row rowsep="0">
+ <entry></entry>
+ <entry></entry>
+ <entry></entry>
+ <entry spanname="col4_on">
+Must match the value sent in the previous
+<function>Request</function>
+packet.
+ </entry>
+ </row>
+
+ <row rowsep="0">
+ <entry></entry>
+ <entry></entry>
+ <entry spanname="col3_on">
+<emphasis remap='I'>Display Class</emphasis>: ARRAY8
+ </entry>
+ </row>
+
+ <row rowsep="0">
+ <entry></entry>
+ <entry></entry>
+ <entry></entry>
+ <entry spanname="col4_on">
+Specifies the class of the display.
+See the Display Class Format section,
+which discusses the format of this field.
+ </entry>
+ </row>
+
+
+ <row rowsep="0">
+ <entry></entry>
+ <entry spanname="col2_on">
+Semantics:
+ </entry>
+ </row>
+
+ <row rowsep="0">
+ <entry></entry>
+ <entry></entry>
+ <entry spanname="col3_on">
+A
+<function>Manage</function>
+packet is sent by a display to ask the manager to begin a
+session on the display. If the Session ID is correct the manager
+should open a connection; otherwise, it should respond with a
+<function>Refuse</function>
+or
+<function>Failed</function>
+packet, unless the Session ID matches a currently
+running session or a session that has not yet successfully opened the
+display but has not given up the attempt. In this latter case, the
+<function>Manage</function>
+packet should be ignored.
+This will work as stream connections give positive success indication
+to both halves of the stream, and positive failure indication
+to the connection initiator (which will eventually generate a
+<function>Failed</function>
+packet).
+ </entry>
+ </row>
+
+ <row rowsep="0">
+ <entry></entry>
+ <entry spanname="col2_on">
+Valid Responses:
+ </entry>
+ </row>
+
+ <row rowsep="0">
+ <entry></entry>
+ <entry></entry>
+ <entry spanname="col3_on">
+X connection with correct auth info,
+<function>Refuse ,</function>
+<function>Failed .</function>
+ </entry>
+ </row>
+
+ <row rowsep="0">
+ <entry></entry>
+ <entry spanname="col2_on">
+Problems/Solutions:
+ </entry>
+ </row>
+
+ <row rowsep="0">
+ <entry></entry>
+ <entry></entry>
+ <entry spanname="col3_on">
+Problem:
+ </entry>
+ </row>
+
+ <row rowsep="0">
+ <entry></entry>
+ <entry></entry>
+ <entry></entry>
+ <entry spanname="col4_on">
+<function>Manage</function>
+not received by manager.
+ </entry>
+ </row>
+
+ <row rowsep="0">
+ <entry></entry>
+ <entry></entry>
+ <entry></entry>
+ <entry spanname="col4_on">
+Indication:
+ </entry>
+ </row>
+
+ <row rowsep="0">
+ <entry></entry>
+ <entry></entry>
+ <entry></entry>
+ <entry></entry>
+ <entry spanname="col5_on">
+Display timeout waiting for response.
+ </entry>
+ </row>
+
+ <row rowsep="0">
+ <entry></entry>
+ <entry></entry>
+ <entry></entry>
+ <entry spanname="col4_on">
+Solution:
+ </entry>
+ </row>
+
+ <row rowsep="0">
+ <entry></entry>
+ <entry></entry>
+ <entry></entry>
+ <entry></entry>
+ <entry spanname="col5_on">
+Display resends
+<function>Manage</function>
+message.
+ </entry>
+ </row>
+
+
+ <row rowsep="0">
+ <entry></entry>
+ <entry></entry>
+ <entry spanname="col3_on">
+Problem:
+ </entry>
+ </row>
+
+ <row rowsep="0">
+ <entry></entry>
+ <entry></entry>
+ <entry></entry>
+ <entry spanname="col4_on">
+<function>Manage</function>
+received out of order by manager.
+ </entry>
+ </row>
+
+ <row rowsep="0">
+ <entry></entry>
+ <entry></entry>
+ <entry></entry>
+ <entry spanname="col4_on">
+Indication:
+ </entry>
+ </row>
+
+ <row rowsep="0">
+ <entry></entry>
+ <entry></entry>
+ <entry></entry>
+ <entry></entry>
+ <entry spanname="col5_on">
+Session already in progress with matching Session ID.
+ </entry>
+ </row>
+
+ <row rowsep="0">
+ <entry></entry>
+ <entry></entry>
+ <entry></entry>
+ <entry spanname="col4_on">
+Solution:
+ </entry>
+ </row>
+
+ <row rowsep="0">
+ <entry></entry>
+ <entry></entry>
+ <entry></entry>
+ <entry></entry>
+ <entry spanname="col5_on">
+<function>Manage</function>
+packet ignored.
+ </entry>
+ </row>
+
+ <row rowsep="0">
+ <entry></entry>
+ <entry></entry>
+ <entry></entry>
+ <entry spanname="col4_on">
+Indication:
+ </entry>
+ </row>
+
+ <row rowsep="0">
+ <entry></entry>
+ <entry></entry>
+ <entry></entry>
+ <entry></entry>
+ <entry spanname="col5_on">
+Session ID does not match next Session ID.
+ </entry>
+ </row>
+
+ <row rowsep="0">
+ <entry></entry>
+ <entry></entry>
+ <entry></entry>
+ <entry spanname="col4_on">
+Solution:
+ </entry>
+ </row>
+
+ <row rowsep="0">
+ <entry></entry>
+ <entry></entry>
+ <entry></entry>
+ <entry></entry>
+ <entry spanname="col5_on">
+<function>Refuse</function>
+message is sent.
+ </entry>
+ </row>
+
+
+ <row rowsep="0">
+ <entry></entry>
+ <entry></entry>
+ <entry spanname="col3_on">
+Problem:
+ </entry>
+ </row>
+
+ <row rowsep="0">
+ <entry></entry>
+ <entry></entry>
+ <entry></entry>
+ <entry spanname="col4_on">
+Display cannot be opened on selected stream.
+ </entry>
+ </row>
+
+ <row rowsep="0">
+ <entry></entry>
+ <entry></entry>
+ <entry></entry>
+ <entry spanname="col4_on">
+Indication:
+ </entry>
+ </row>
+
+ <row rowsep="0">
+ <entry></entry>
+ <entry></entry>
+ <entry></entry>
+ <entry></entry>
+ <entry spanname="col5_on">
+Display connection setup fails.
+ </entry>
+ </row>
+
+ <row rowsep="0">
+ <entry></entry>
+ <entry></entry>
+ <entry></entry>
+ <entry spanname="col4_on">
+Solution:
+ </entry>
+ </row>
+
+ <row rowsep="0">
+ <entry></entry>
+ <entry></entry>
+ <entry></entry>
+ <entry></entry>
+ <entry spanname="col5_on">
+<function>Failed</function>
+message is sent including a human readable reason.
+ </entry>
+ </row>
+
+ <row rowsep="0">
+ <entry></entry>
+ <entry></entry>
+ <entry spanname="col3_on">
+Problem:
+ </entry>
+ </row>
+
+ <row rowsep="0">
+ <entry></entry>
+ <entry></entry>
+ <entry></entry>
+ <entry spanname="col4_on">
+Display open does not succeed before a second manage packet is received
+because of a timeout occuring in the display.
+ </entry>
+ </row>
+
+ <row rowsep="0">
+ <entry></entry>
+ <entry></entry>
+ <entry></entry>
+ <entry spanname="col4_on">
+Indication:
+ </entry>
+ </row>
+
+ <row rowsep="0">
+ <entry></entry>
+ <entry></entry>
+ <entry></entry>
+ <entry></entry>
+ <entry spanname="col5_on">
+<function>Manage</function>
+packet received with Session ID matching the session
+attempting to connect to the display.
+ </entry>
+ </row>
+
+ <row rowsep="0">
+ <entry></entry>
+ <entry></entry>
+ <entry></entry>
+ <entry spanname="col4_on">
+Solution:
+ </entry>
+ </row>
+
+ <row rowsep="0">
+ <entry></entry>
+ <entry></entry>
+ <entry></entry>
+ <entry></entry>
+ <entry spanname="col5_on">
+<function>Manage</function>
+packet is ignored. As the stream connection will either
+succeed, which will result in an active session, or the stream will
+eventually give up hope of connecting and send a
+<function>Failed</function>
+packet; no response to this
+<function>Manage</function>
+packet is necessary.
+ </entry>
+ </row>
+
+ <row rowsep="0">
+ <entry></entry>
+ <entry spanname="col2_on">
+Timeout/Retransmission policy:
+ </entry>
+ </row>
+
+ <row rowsep="0">
+ <entry></entry>
+ <entry></entry>
+ <entry spanname="col3_on">
+Timeout after 2 seconds, exponential backoff to 32 seconds. After no more
+than 126 seconds, give up and report an error to the user.
+ </entry>
+ </row>
+
+ <row rowsep="0">
+ <entry spanname="col1_on">
+<function>Refuse</function>
+ </entry>
+ </row>
+
+ <row rowsep="0">
+ <entry></entry>
+ <entry spanname="col2_on">
+ <para>
+Manager -&gt; Display
+ </para>
+ <para>
+Additional Fields:
+ </para>
+ </entry>
+ </row>
+
+ <row rowsep="0">
+ <entry></entry>
+ <entry></entry>
+ <entry spanname="col3_on">
+<emphasis remap='I'>Session ID</emphasis>: CARD32
+ </entry>
+ </row>
+
+ <row rowsep="0">
+ <entry></entry>
+ <entry></entry>
+ <entry></entry>
+ <entry spanname="col4_on">
+Should be set to the Session ID received in the
+<function>Manage</function>
+packet.
+ </entry>
+ </row>
+
+
+ <row rowsep="0">
+ <entry></entry>
+ <entry spanname="col2_on">
+Semantics:
+ </entry>
+ </row>
+
+ <row rowsep="0">
+ <entry></entry>
+ <entry></entry>
+ <entry spanname="col3_on">
+A
+<function>Refuse</function>
+packet is sent by a manager when the Session ID received in the
+<function>Manage</function>
+packet does not match the current Session ID.
+The display should assume that it received an old
+<function>Accept</function>
+packet and should resend its
+<function>Request</function>
+packet.
+ </entry>
+ </row>
+
+ <row rowsep="0">
+ <entry></entry>
+ <entry spanname="col2_on">
+Problems/Solutions:
+ </entry>
+ </row>
+
+ <row rowsep="0">
+ <entry></entry>
+ <entry></entry>
+ <entry spanname="col3_on">
+Problem:
+ </entry>
+ </row>
+
+ <row rowsep="0">
+ <entry></entry>
+ <entry></entry>
+ <entry></entry>
+ <entry spanname="col4_on">
+Error message is lost.
+ </entry>
+ </row>
+
+ <row rowsep="0">
+ <entry></entry>
+ <entry></entry>
+ <entry></entry>
+ <entry spanname="col4_on">
+Indication:
+ </entry>
+ </row>
+
+ <row rowsep="0">
+ <entry></entry>
+ <entry></entry>
+ <entry></entry>
+ <entry></entry>
+ <entry spanname="col5_on">
+Display times out waiting for
+new connection,
+<function>Refuse</function>
+or
+<function>Failed .</function>
+ </entry>
+ </row>
+
+ <row rowsep="0">
+ <entry></entry>
+ <entry></entry>
+ <entry></entry>
+ <entry spanname="col4_on">
+Solution:
+ </entry>
+ </row>
+
+ <row rowsep="0">
+ <entry></entry>
+ <entry></entry>
+ <entry></entry>
+ <entry></entry>
+ <entry spanname="col5_on">
+Display resends
+<function>Manage</function>
+message.
+ </entry>
+ </row>
+
+
+
+ <row rowsep="0">
+ <entry></entry>
+ <entry spanname="col2_on">
+Timeout/Retransmission policy:
+ </entry>
+ </row>
+
+ <row rowsep="0">
+ <entry></entry>
+ <entry></entry>
+ <entry spanname="col3_on">
+Like all packets sent from a manager to a display, this packet should never be
+retransmitted.
+ </entry>
+ </row>
+
+ <row rowsep="0">
+ <entry spanname="col1_on">
+<function>Failed</function>
+ </entry>
+ </row>
+
+ <row rowsep="0">
+ <entry></entry>
+ <entry spanname="col2_on">
+ <para>
+Manager -&gt; Display
+ </para>
+ <para>
+Additional Fields:
+ </para>
+ </entry>
+ </row>
+
+ <row rowsep="0">
+ <entry></entry>
+ <entry></entry>
+ <entry spanname="col3_on">
+<emphasis remap='I'>Session ID</emphasis>: CARD32
+ </entry>
+ </row>
+
+ <row rowsep="0">
+ <entry></entry>
+ <entry></entry>
+ <entry></entry>
+ <entry spanname="col4_on">
+Should be set to the Session ID received in the
+<function>Manage</function>
+packet.
+ </entry>
+ </row>
+
+ <row rowsep="0">
+ <entry></entry>
+ <entry></entry>
+ <entry spanname="col3_on">
+<emphasis remap='I'>Status</emphasis>: ARRAY8
+ </entry>
+ </row>
+
+ <row rowsep="0">
+ <entry></entry>
+ <entry></entry>
+ <entry></entry>
+ <entry spanname="col4_on">
+Is a human readable string indicating the reason for failure.
+ </entry>
+ </row>
+
+
+ <row rowsep="0">
+ <entry></entry>
+ <entry spanname="col2_on">
+Semantics:
+ </entry>
+ </row>
+
+ <row rowsep="0">
+ <entry></entry>
+ <entry></entry>
+ <entry spanname="col3_on">
+A
+<function>Failed</function>
+packet is sent by a manager when it has problems establishing
+the initial X connection in response to the
+<function>Manage</function>
+packet.
+ </entry>
+ </row>
+
+ <row rowsep="0">
+ <entry></entry>
+ <entry spanname="col2_on">
+Problems/Solutions
+ </entry>
+ </row>
+
+ <row rowsep="0">
+ <entry></entry>
+ <entry></entry>
+ <entry spanname="col3_on">
+Same as for
+<function>Refuse .</function>
+ </entry>
+ </row>
+
+ <row rowsep="0">
+ <entry spanname="col1_on">
+<function>KeepAlive</function>
+ </entry>
+ </row>
+
+ <row rowsep="0">
+ <entry></entry>
+ <entry spanname="col2_on">
+ <para>
+Display -&gt; Manager
+ </para>
+ <para>
+Additional Fields:
+ </para>
+ </entry>
+ </row>
+
+ <row rowsep="0">
+ <entry></entry>
+ <entry></entry>
+ <entry spanname="col3_on">
+<emphasis remap='I'>Display Number</emphasis>: CARD16
+ </entry>
+ </row>
+
+ <row rowsep="0">
+ <entry></entry>
+ <entry></entry>
+ <entry></entry>
+ <entry spanname="col4_on">
+Set to the display index for the display host.
+ </entry>
+ </row>
+
+ <row rowsep="0">
+ <entry></entry>
+ <entry></entry>
+ <entry spanname="col3_on">
+<emphasis remap='I'>Session ID</emphasis>: CARD32
+ </entry>
+ </row>
+
+ <row rowsep="0">
+ <entry></entry>
+ <entry></entry>
+ <entry></entry>
+ <entry spanname="col4_on">
+Should be set to the Session ID received in the
+<function>Manage</function>
+packet during the negotiation for the current session.
+ </entry>
+ </row>
+
+ <row rowsep="0">
+ <entry></entry>
+ <entry spanname="col2_on">
+Sematics:
+ </entry>
+ </row>
+
+ <row rowsep="0">
+ <entry></entry>
+ <entry></entry>
+ <entry spanname="col3_on">
+ <para>
+A
+<function>KeepAlive</function>
+packet can be sent at any time during the session by a
+display to discover if the manager is running.
+The manager should respond with
+<function>Alive</function>
+whenever it receives this type of packet.
+ </para>
+ <para>
+This allows the display to discover when the manager host
+is no longer running.
+A display is not required to send
+<function>KeepAlive</function>
+packets and, upon lack of receipt of
+<function>Alive</function>
+packets, is not required to perform any specific action.
+ </para>
+ <para>
+The expected use of this packet is to terminate an active session when the
+manager host or network link fails. The display should keep track of the
+time since any packet has been received from the manager host and use
+<function>KeepAlive</function>
+packets when a substantial time has elapsed since the
+most recent packet.
+ </para>
+ </entry>
+ </row>
+
+ <row rowsep="0">
+ <entry></entry>
+ <entry spanname="col2_on">
+Valid Responses:
+ </entry>
+ </row>
+
+ <row rowsep="0">
+ <entry></entry>
+ <entry></entry>
+ <entry spanname="col3_on">
+<function>Alive</function>
+ </entry>
+ </row>
+
+ <row rowsep="0">
+ <entry></entry>
+ <entry spanname="col2_on">
+Problems/Solutions:
+ </entry>
+ </row>
+
+ <row rowsep="0">
+ <entry></entry>
+ <entry></entry>
+ <entry spanname="col3_on">
+Problem:
+ </entry>
+ </row>
+
+ <row rowsep="0">
+ <entry></entry>
+ <entry></entry>
+ <entry></entry>
+ <entry spanname="col4_on">
+Manager does not receive the packet or display does not receive the response.
+ </entry>
+ </row>
+
+
+ <row rowsep="0">
+ <entry></entry>
+ <entry></entry>
+ <entry></entry>
+ <entry spanname="col4_on">
+Indication:
+ </entry>
+ </row>
+
+ <row rowsep="0">
+ <entry></entry>
+ <entry></entry>
+ <entry></entry>
+ <entry></entry>
+ <entry spanname="col5_on">
+No
+<function>Alive</function>
+packet is returned.
+ </entry>
+ </row>
+
+ <row rowsep="0">
+ <entry></entry>
+ <entry></entry>
+ <entry></entry>
+ <entry spanname="col4_on">
+Solution:
+ </entry>
+ </row>
+
+ <row rowsep="0">
+ <entry></entry>
+ <entry></entry>
+ <entry></entry>
+ <entry></entry>
+ <entry spanname="col5_on">
+Retransmit the packet with an exponential backoff; start at 2 seconds and
+assume the host is not up after no less than 30 seconds.
+ </entry>
+ </row>
+
+ <row rowsep="0">
+ <entry spanname="col1_on">
+<function>Alive</function>
+ </entry>
+ </row>
+
+ <row rowsep="0">
+ <entry></entry>
+ <entry spanname="col2_on">
+ <para>
+Manager -&gt; Display
+ </para>
+ <para>
+Additional Fields:
+ </para>
+ </entry>
+ </row>
+
+ <row rowsep="0">
+ <entry></entry>
+ <entry></entry>
+ <entry spanname="col3_on">
+<emphasis remap='I'>Session Running</emphasis>: CARD8
+ </entry>
+ </row>
+
+ <row rowsep="0">
+ <entry></entry>
+ <entry></entry>
+ <entry></entry>
+ <entry spanname="col4_on">
+Indicates that the session identified by Session ID is
+currently active. The value is zero if no session is active
+or one if a session
+is active.
+ </entry>
+ </row>
+
+ <row rowsep="0">
+ <entry></entry>
+ <entry></entry>
+ <entry spanname="col3_on">
+<emphasis remap='I'>Session ID</emphasis>: CARD32
+ </entry>
+ </row>
+
+ <row rowsep="0">
+ <entry></entry>
+ <entry></entry>
+ <entry></entry>
+ <entry spanname="col4_on">
+Specifies the ID of the currently running session; if any.
+When no session is active this field should be zero.
+ </entry>
+ </row>
+
+
+ <row rowsep="0">
+ <entry></entry>
+ <entry spanname="col2_on">
+Semantics:
+ </entry>
+ </row>
+
+ <row rowsep="0">
+ <entry></entry>
+ <entry></entry>
+ <entry spanname="col3_on">
+An
+<function>Alive</function>
+packet is sent in response to a
+<function>KeepAlive</function>
+request.
+If a session is currently active on the display, the manager includes the
+Session ID in the packet. The display can use this information to
+determine the status of the manager.
+ </entry>
+ </row>
+ </tbody>
+ </tgroup>
+</informaltable>
+
+</chapter>
+
+<chapter id="Session_Termination">
+<title>Session Termination</title>
+<para>
+When the session is over, the initial connection with the display (the one
+that acknowledges the
+<function>Manage</function>
+packet) will be closed by the manager.
+If only a single session was active on the display,
+all other connections should be closed by the display
+and the display should be reset. If multiple sessions
+are active simultaneously and the display can identify which connections
+belong to the terminated sesssion, those connections should be closed.
+Otherwise, all connections should be closed and the display reset only when
+all sessions have been terminated (that is, all initial connections closed).
+</para>
+
+<para>
+The session may also be terminated at any time by the display if the
+managing host no longer responds to
+<function>KeepAlive</function>
+packets.
+The exact time-outs for sending
+<function>KeepAlive</function>
+packets is not specified in this protocol as the trade off
+should not be fixed between loading an otherwise idle system with spurious
+<function>KeepAlive</function>
+packets and not noticing that the manager host is down for a long time.
+</para>
+</chapter>
+
+<chapter id="State_Diagrams">
+<title>State Diagrams</title>
+<!-- .XS -->
+<!-- (SN State Diagrams -->
+<!-- .XE -->
+<para>
+<!-- .LP -->
+The following state diagrams are designed to cover all actions of both
+the display and the manager. Any packet that is received out-of-sequence
+will be ignored.
+</para>
+<para>
+<!-- .LP -->
+Display:
+</para>
+
+<variablelist>
+ <varlistentry>
+ <term><emphasis remap='I'>start</emphasis>:</term>
+ <listitem>
+ <para>
+User-requested connect to one host -&gt; <emphasis remap='I'>query</emphasis>
+ </para>
+ <para>
+User-requested connect to some host -&gt; <emphasis remap='I'>broadcast</emphasis>
+ </para>
+ <para>
+User-requested connect to site host-list -&gt; <emphasis remap='I'>indirect</emphasis>
+ </para>
+ </listitem>
+ </varlistentry>
+ <varlistentry>
+ <term><emphasis remap='I'>query</emphasis>:</term>
+ <listitem>
+ <para>
+Send <function>Query</function> packet
+-&gt; <emphasis remap='I'>collect-query</emphasis>
+ </para>
+ </listitem>
+ </varlistentry>
+ <varlistentry>
+ <term><emphasis remap='I'>collect-query</emphasis>:</term>
+ <listitem>
+ <para>
+Receive <function>Willing</function> -&gt;
+<emphasis remap='I'>start-connection</emphasis>
+ </para>
+ <para>
+Receive <function>Unwilling</function> -&gt;
+<emphasis remap='I'>stop-connection</emphasis>
+ </para>
+ <para>
+Timeout -&gt; <emphasis remap='I'>query</emphasis>
+ </para>
+ </listitem>
+ </varlistentry>
+
+ <varlistentry>
+ <term><emphasis remap='I'>broadcast</emphasis>:</term>
+ <listitem>
+ <para>
+Send <function>BroadcastQuery</function> packet
+ </para>
+ <para>
+-&gt; <emphasis remap='I'>collect-broadcast-query</emphasis>
+ </para>
+ </listitem>
+ </varlistentry>
+ <varlistentry>
+ <term><emphasis remap='I'>collect-broadcast-query</emphasis>:</term>
+ <listitem>
+ <para>
+Receive <function>Willing</function> -&gt;
+<emphasis remap='I'>update-broadcast-willing</emphasis>
+ </para>
+ <para>
+User-requested connect to one host -&gt;
+<emphasis remap='I'>start-connection</emphasis>
+ </para>
+ <para>
+Timeout -&gt; <emphasis remap='I'>broadcast</emphasis>
+ </para>
+ </listitem>
+ </varlistentry>
+ <varlistentry>
+ <term><emphasis remap='I'>update-broadcast-willing</emphasis>:</term>
+ <listitem>
+ <para>
+Add new host to the host list presented to the user
+ </para>
+ <para>
+-&gt; <emphasis remap='I'>collect-broadcast-query</emphasis>
+ </para>
+ </listitem>
+ </varlistentry>
+ <varlistentry>
+ <term><emphasis remap='I'>indirect</emphasis>:</term>
+ <listitem>
+ <para>
+Send <function>IndirectQuery</function> packet
+ </para>
+ <para>
+-&gt; <emphasis remap='I'>collect-indirect-query</emphasis>
+ </para>
+ </listitem>
+ </varlistentry>
+ <varlistentry>
+ <term><emphasis remap='I'>collect-indirect-query</emphasis>:</term>
+ <listitem>
+ <para>
+Receive <function>Willing</function> -&gt;
+<emphasis remap='I'>update-indirect-willing</emphasis>
+ </para>
+ <para>
+User-requested connect to one host -&gt;
+<emphasis remap='I'>start-connection</emphasis>
+ </para>
+ <para>
+Timeout -&gt; <emphasis remap='I'>indirect</emphasis>
+ </para>
+ </listitem>
+ </varlistentry>
+ <varlistentry>
+ <term><emphasis remap='I'>update-indirect-willing</emphasis>:</term>
+ <listitem>
+ <para>
+Add new host to the host list presented to the user
+ </para>
+ <para>
+-&gt; <emphasis remap='I'>collect-indirect-query</emphasis>
+ </para>
+ </listitem>
+ </varlistentry>
+
+ <varlistentry>
+ <term><emphasis remap='I'>start-connection</emphasis>:</term>
+ <listitem>
+ <para>
+Send <function>Request</function> packet
+ </para>
+ <para>
+-&gt; <emphasis remap='I'>await-request-response</emphasis>
+ </para>
+ </listitem>
+ </varlistentry>
+ <varlistentry>
+ <term><emphasis remap='I'>await-request-response</emphasis>:</term>
+ <listitem>
+ <para>
+Receive <function>Accept</function> -&gt;
+<emphasis remap='I'>manage</emphasis>
+ </para>
+ <para>
+Receive <function>Decline</function> -&gt;
+<emphasis remap='I'>stop-connection</emphasis>
+ </para>
+ <para>
+Timeout -&gt; <emphasis remap='I'>start-connection</emphasis>
+ </para>
+ </listitem>
+ </varlistentry>
+ <varlistentry>
+ <term><emphasis remap='I'>manage</emphasis>:</term>
+ <listitem>
+ <para>
+Save Session ID
+ </para>
+ <para>
+Send <function>Manage</function> packet with Session ID
+ </para>
+ <para>
+-&gt; <emphasis remap='I'>await-manage-response</emphasis>
+ </para>
+ </listitem>
+ </varlistentry>
+ <varlistentry>
+ <term><emphasis remap='I'>await-manage-response</emphasis>:</term>
+ <listitem>
+ <para>
+Receive <function>XOpenDisplay :</function> -&gt;
+<emphasis remap='I'>run-session</emphasis>
+ </para>
+ <para>
+Receive <function>Refuse</function> with matching Session ID
+-&gt; <emphasis remap='I'>start-connection</emphasis>
+ </para>
+ <para>
+Receive <function>Failed</function> with matching Session ID
+-&gt; <emphasis remap='I'>stop-connection</emphasis>
+ </para>
+ <para>
+Timeout -&gt; <emphasis remap='I'>manage</emphasis>
+ </para>
+ </listitem>
+ </varlistentry>
+ <varlistentry>
+ <term><emphasis remap='I'>stop-connection</emphasis>:</term>
+ <listitem>
+ <para>
+Display cause of termination to user
+ </para>
+ <para>
+-&gt; <emphasis remap='I'>start</emphasis>
+ </para>
+ </listitem>
+ </varlistentry>
+ <varlistentry>
+ <term><emphasis remap='I'>run-session</emphasis>:</term>
+ <listitem>
+ <para>
+Decide to send <function>KeepAlive</function> packet -&gt;
+<emphasis remap='I'>keep-alive</emphasis>
+ </para>
+ <para>
+wait close of first display connection
+ </para>
+ <para>
+-&gt; <emphasis remap='I'>reset-display</emphasis>
+ </para>
+ </listitem>
+ </varlistentry>
+ <varlistentry>
+ <term><emphasis remap='I'>keep-alive</emphasis>:</term>
+ <listitem>
+ <para>
+Send <function>KeepAlive</function> packet with current Session ID
+ </para>
+ <para>
+-&gt; <emphasis remap='I'>await-alive</emphasis>
+ </para>
+ </listitem>
+ </varlistentry>
+ <varlistentry>
+ <term><emphasis remap='I'>await-alive</emphasis>:</term>
+ <listitem>
+ <para>
+Receive <function>Alive</function> with matching Session ID -&gt;
+<emphasis remap='I'>run-session</emphasis>
+ </para>
+ <para>
+Receive <function>Alive</function> with nonmatching Session ID
+or FALSE Session Running -&gt; <emphasis remap='I'>reset-display</emphasis>
+ </para>
+ <para>
+Final timeout without receiving <function>Alive</function>
+packet -&gt; <emphasis remap='I'>reset-display</emphasis>
+ </para>
+ <para>
+Timeout -&gt; <emphasis remap='I'>keep-alive</emphasis>
+ </para>
+ </listitem>
+ </varlistentry>
+ <varlistentry>
+ <term><emphasis remap='I'>reset-display</emphasis>:</term>
+ <listitem>
+ <para>
+(if possible) -&gt; close all display connections associated with this session
+ </para>
+ <para>
+Last session -&gt; close all display connections
+ </para>
+ <para>
+-&gt; <emphasis remap='I'>start</emphasis>
+ </para>
+ </listitem>
+ </varlistentry>
+</variablelist>
+
+
+<para>
+Manager:
+</para>
+
+<variablelist>
+ <varlistentry>
+ <term><emphasis remap='I'>idle</emphasis>:</term>
+ <listitem>
+ <para>
+Receive <function>Query</function> -&gt;
+<emphasis remap='I'>query-respond</emphasis>
+ </para>
+ <para>
+Receive
+<function>BroadcastQuery</function>
+-&gt; <emphasis remap='I'>broadcast-respond</emphasis>
+ </para>
+ <para>
+Receive
+<function>IndirectQuery</function>
+-&gt; <emphasis remap='I'>indirect-respond</emphasis>
+ </para>
+ <para>
+Receive
+<function>ForwardQuery</function>
+-&gt; <emphasis remap='I'>forward-respond</emphasis>
+Receive
+ </para>
+ <para>
+<function>Request</function>
+-&gt; <emphasis remap='I'>request-respond</emphasis>
+ </para>
+ <para>
+Receive
+<function>Manage</function>
+-&gt; <emphasis remap='I'>manage</emphasis>
+ </para>
+ <para>
+An active session terminates
+-&gt; <emphasis remap='I'>finish-session</emphasis>
+ </para>
+ <para>
+Receive <function>KeepAlive</function>
+-&gt; <emphasis remap='I'>send-alive</emphasis>
+ </para>
+ <para>
+-&gt; <emphasis remap='I'>idle</emphasis>
+ </para>
+ </listitem>
+ </varlistentry>
+ <varlistentry>
+ <term><emphasis remap='I'>query-respond</emphasis>:</term>
+ <listitem>
+ <para>
+If willing to manage -&gt; <emphasis remap='I'>send-willing</emphasis>
+ </para>
+ <para>
+-&gt; <emphasis remap='I'>send-unwilling</emphasis>
+ </para>
+ </listitem>
+ </varlistentry>
+ <varlistentry>
+ <term><emphasis remap='I'>broadcast-respond</emphasis>:</term>
+ <listitem>
+ <para>
+If willing to manage -&gt; <emphasis remap='I'>send-willing</emphasis>
+ </para>
+ <para>
+-&gt; <emphasis remap='I'>idle</emphasis>
+ </para>
+ </listitem>
+ </varlistentry>
+ <varlistentry>
+ <term><emphasis remap='I'>indirect-respond</emphasis>:</term>
+ <listitem>
+ <para>
+Send <function>ForwardQuery</function>
+packets to all managers on redirect list
+ </para>
+ <para>
+If willing to manage -&gt; <emphasis remap='I'>send-willing</emphasis>
+ </para>
+ <para>
+-&gt; <emphasis remap='I'>idle</emphasis>
+ </para>
+ </listitem>
+ </varlistentry>
+ <varlistentry>
+ <term><emphasis remap='I'>forward-respond</emphasis>:</term>
+ <listitem>
+ <para>
+Decode destination address, if willing to manage -&gt;
+<emphasis remap='I'>send-willing</emphasis>
+ </para>
+ <para>
+-&gt; <emphasis remap='I'>idle</emphasis>
+ </para>
+ </listitem>
+ </varlistentry>
+ <varlistentry>
+ <term><emphasis remap='I'>send-willing</emphasis>:</term>
+ <listitem>
+ <para>
+Send <function>Willing</function> packet
+ </para>
+ <para>
+-&gt; <emphasis remap='I'>idle</emphasis>
+ </para>
+ </listitem>
+ </varlistentry>
+ <varlistentry>
+ <term><emphasis remap='I'>send-unwilling</emphasis>:</term>
+ <listitem>
+ <para>
+Send <function>Unwilling</function> packet
+-&gt; <emphasis remap='I'>idle</emphasis>
+ </para>
+ </listitem>
+ </varlistentry>
+ <varlistentry>
+ <term><emphasis remap='I'>request-respond</emphasis>:</term>
+ <listitem>
+ <para>
+If manager is willing to allow a session on display
+-&gt; <emphasis remap='I'>accept-session</emphasis>
+ </para>
+ <para>
+-&gt; <emphasis remap='I'>decline-session</emphasis>
+ </para>
+ </listitem>
+ </varlistentry>
+ <varlistentry>
+ <term><emphasis remap='I'>accept-session</emphasis>:</term>
+ <listitem>
+ <para>
+Generate Session ID and save Session ID, display address, and
+display number somewhere
+ </para>
+ <para>
+Send <function>Accept</function> packet
+ </para>
+ <para>
+-&gt; <emphasis remap='I'>idle</emphasis>
+ </para>
+ </listitem>
+ </varlistentry>
+ <varlistentry>
+ <term><emphasis remap='I'>decline-session</emphasis>:</term>
+ <listitem>
+ <para>
+Send <function>Decline</function> packet
+ </para>
+ <para>
+-&gt; <emphasis remap='I'>idle</emphasis>
+ </para>
+ </listitem>
+ </varlistentry>
+ <varlistentry>
+ <term><emphasis remap='I'>manage</emphasis>:</term>
+ <listitem>
+ <para>
+If Session ID matches saved Session ID -&gt;
+<emphasis remap='I'>run-session</emphasis>
+ </para>
+ <para>
+If Session ID matches Session ID of session in process of
+starting up, or currently active session -&gt;
+<emphasis remap='I'>idle</emphasis>
+ </para>
+ <para>
+-&gt; <emphasis remap='I'>refuse</emphasis>
+ </para>
+ </listitem>
+ </varlistentry>
+ <varlistentry>
+ <term><emphasis remap='I'>refuse</emphasis>:</term>
+ <listitem>
+ <para>
+Send <function>Refuse</function> packet
+ </para>
+ <para>
+-&gt; <emphasis remap='I'>idle</emphasis>
+ </para>
+ </listitem>
+ </varlistentry>
+ <varlistentry>
+ <term><emphasis remap='I'>run-session</emphasis>:</term>
+ <listitem>
+ <para>
+Terminate any session in progress
+ </para>
+ <para>
+<function>XOpenDisplay</function>
+ </para>
+ <para>
+Open display succeeds -&gt;
+<emphasis remap='I'>start-session</emphasis>
+ </para>
+ <para>
+-&gt; <emphasis remap='I'>failed</emphasis>
+ </para>
+ </listitem>
+ </varlistentry>
+ <varlistentry>
+ <term><emphasis remap='I'>failed</emphasis>:</term>
+ <listitem>
+ <para>
+Send <function>Failed</function> packet
+ </para>
+ <para>
+-&gt; <emphasis remap='I'>idle</emphasis>
+ </para>
+ </listitem>
+ </varlistentry>
+ <varlistentry>
+ <term><emphasis remap='I'>start-session</emphasis>:</term>
+ <listitem>
+ <para>
+Start a new session
+ </para>
+ <para>
+-&gt; <emphasis remap='I'>idle</emphasis>
+ </para>
+ </listitem>
+ </varlistentry>
+ <varlistentry>
+ <term><emphasis remap='I'>finish-session</emphasis>:</term>
+ <listitem>
+ <para>
+<function>XCloseDisplay</function>
+ </para>
+ <para>
+-&gt; <emphasis remap='I'>idle</emphasis>
+ </para>
+ </listitem>
+ </varlistentry>
+ <varlistentry>
+ <term><emphasis remap='I'>send-alive</emphasis>:</term>
+ <listitem>
+ <para>
+Send <function>Alive</function> packet containing current status
+ </para>
+ <para>
+-&gt; <emphasis remap='I'>idle</emphasis>
+ </para>
+ </listitem>
+ </varlistentry>
+</variablelist>
+
+</chapter>
+
+<chapter id="Protocol_Encoding">
+<title>Protocol Encoding</title>
+<para>
+When XDMCP is implemented on top of the Internet User Datagram Protocol (UDP),
+port number 177 is to be used. When using UDP over IPv4, Broadcast Query
+packets are sent via UDP broadcast. When using UDP over IPv6, Broadcast Query
+packets are sent via multicast, either to an address in the IANA registered
+XDMCP multicast address range of
+FF0<emphasis remap='I'>X</emphasis>:0:0:0:0:0:0:12B
+(where the <emphasis remap='I'>X</emphasis> is replaced by a valid scope id)
+or to a locally assigned
+multicast address. The version number in all packets will be 1.
+Packet opcodes are 16-bit integers.
+</para>
+
+<informaltable frame="none">
+ <tgroup cols='2' align='left'>
+ <colspec colname='c1' colsep="0"/>
+ <colspec colname='c2' colsep="0"/>
+ <thead>
+ <row>
+ <entry>Packet Name</entry>
+ <entry>Encoding</entry>
+ </row>
+ </thead>
+ <tbody>
+ <row rowsep="0">
+ <entry>BroadcastQuery</entry>
+ <entry>1</entry>
+ </row>
+ <row rowsep="0">
+ <entry>Query</entry>
+ <entry>2</entry>
+ </row>
+ <row rowsep="0">
+ <entry>IndirectQuery</entry>
+ <entry>3</entry>
+ </row>
+ <row rowsep="0">
+ <entry>ForwardQuery</entry>
+ <entry>4</entry>
+ </row>
+ <row rowsep="0">
+ <entry>Willing</entry>
+ <entry>5</entry>
+ </row>
+ <row rowsep="0">
+ <entry>Unwilling</entry>
+ <entry>6</entry>
+ </row>
+ <row rowsep="0">
+ <entry>Request</entry>
+ <entry>7</entry>
+ </row>
+ <row rowsep="0">
+ <entry>Accept</entry>
+ <entry>8</entry>
+ </row>
+ <row rowsep="0">
+ <entry>Decline</entry>
+ <entry>9</entry>
+ </row>
+ <row rowsep="0">
+ <entry>Manage</entry>
+ <entry>10</entry>
+ </row>
+ <row rowsep="0">
+ <entry>Refuse</entry>
+ <entry>11</entry>
+ </row>
+ <row rowsep="0">
+ <entry>Failed</entry>
+ <entry>12</entry>
+ </row>
+ <row rowsep="0">
+ <entry>KeepAlive</entry>
+ <entry>13
+<footnote><para>
+A previous version of this document incorrectly reversed the opcodes of
+<emphasis role="bold">Alive</emphasis> and
+<emphasis role="bold">KeepAlive</emphasis>.
+</para></footnote>
+ </entry>
+ </row>
+ <row rowsep="0">
+ <entry>Alive</entry>
+ <entry>14
+<footnote><para>
+A previous version of this document incorrectly reversed the opcodes of
+<emphasis role="bold">Alive</emphasis> and
+<emphasis role="bold">KeepAlive</emphasis>.
+</para></footnote>
+ </entry>
+ </row>
+ </tbody>
+ </tgroup>
+</informaltable>
+
+<para>
+Per packet information follows:
+</para>
+
+<para>
+<function>Query</function>,
+<function>BroadcastQuery</function>,
+<function>IndirectQuery</function>
+</para>
+
+<literallayout class="monospaced">
+ 2 CARD16 version number (always 1)
+ 2 CARD16 opcode (always Query, BroadcastQuery or IndirectQuery)
+ 2 CARD16 length
+ 1 CARD8 number of Authentication Names sent (m)
+ 2 CARD16 length of first Authentication Name (m<emphasis role="subscript">1</emphasis>)
+ m<emphasis role="subscript">1</emphasis> CARD8 first Authentication Name
+ ... Other Authentication Names
+</literallayout>
+
+<para>
+Note that these three packets are identical except for the opcode field.
+</para>
+
+<literallayout class="monospaced">
+<function>ForwardQuery</function>
+ 2 CARD16 version number (always 1)
+ 2 CARD16 opcode (always ForwardQuery)
+ 2 CARD16 length
+ 2 CARD16 length of Client Address (m)
+ m CARD8 Client Address
+ 2 CARD16 length of Client Port (n)
+ n CARD8 Client Port
+ 1 CARD8 number of Authentication Names sent (o)
+ 2 CARD16 length of first Authentication Name (o<emphasis role="subscript">1</emphasis>)
+ o<emphasis role="subscript">1</emphasis> CARD8 first Authentication Name
+ ... Other Authentication Names
+</literallayout>
+
+<literallayout class="monospaced">
+<function>Willing</function>
+ 2 CARD16 version number (always 1)
+ 2 CARD16 opcode (always Willing)
+ 2 CARD16 length (6 + m + n + o)
+ 2 CARD16 Length of Authentication Name (m)
+ m CARD8 Authentication Name
+ 2 CARD16 Hostname length (n)
+ n CARD8 Hostname
+ 2 CARD16 Status length (o)
+ o CARD8 Status
+</literallayout>
+
+<literallayout class="monospaced">
+<function>Unwilling</function>
+ 2 CARD16 version number (always 1)
+ 2 CARD16 opcode (always Unwilling)
+ 2 CARD16 length (4 + m + n)
+ 2 CARD16 Hostname length (m)
+ m CARD8 Hostname
+ 2 CARD16 Status length (n)
+ n CARD8 Status
+</literallayout>
+
+<literallayout class="monospaced">
+<function>Request</function>
+ 2 CARD16 version number (always 1)
+ 2 CARD16 opcode (always Request)
+ 2 CARD16 length
+ 2 CARD16 Display Number
+ 1 CARD8 Count of Connection Types (m)
+ 2xm CARD16 Connection Types
+ 1 CARD8 Count of Connection Addresses (n)
+ 2 CARD16 Length of first Connection Address (n<emphasis role="subscript">1</emphasis>)
+ n<emphasis role="subscript">1</emphasis> CARD8 First Connection Address
+ ... Other connection addresses
+ 2 CARD16 Length of Authentication Name (o)
+ o CARD8 Authentication Name
+ 2 CARD16 Length of Authentication Data (p)
+ p CARD8 Authentication Data
+ 1 CARD8 Count of Authorization Names (q)
+ 2 CARD16 Length of first Authorization Name (q<emphasis role="subscript">1</emphasis>)
+ q<emphasis role="subscript">1</emphasis> CARD8 First Authorization Name
+ ... Other authorization names
+ 2 CARD16 Length of Manufacturer Display ID (r)
+ r CARD8 Manufacturer Display ID
+</literallayout>
+
+<literallayout class="monospaced">
+<function>Accept</function>
+ 2 CARD16 version number (always 1)
+ 2 CARD16 opcode (always Accept)
+ 2 CARD16 length (12 + n + m + o + p)
+ 4 CARD32 Session ID
+ 2 CARD16 Length of Authentication Name (n)
+ n CARD8 Authentication Name
+ 2 CARD16 Length of Authentication Data (m)
+ m CARD8 Authentication Data
+ 2 CARD16 Length of Authorization Name (o)
+ o CARD8 Authorization Name
+ 2 CARD16 Length of Authorization Data (p)
+ p CARD8 Authorization Data
+</literallayout>
+
+<literallayout class="monospaced">
+<function>Decline</function>
+ 2 CARD16 version number (always 1)
+ 2 CARD16 opcode (always Decline)
+ 2 CARD16 length (6 + m + n + o)
+ 2 CARD16 Length of Status (m)
+ m CARD8 Status
+ 2 CARD16 Length of Authentication Name (n)
+ n CARD8 Authentication Name
+ 2 CARD16 Length of Authentication Data (o)
+ o CARD8 Authentication Data
+</literallayout>
+
+<literallayout class="monospaced">
+<function>Manage</function>
+ 2 CARD16 version number (always 1)
+ 2 CARD16 opcode (always Manage)
+ 2 CARD16 length (8 + m)
+ 4 CARD32 Session ID
+ 2 CARD16 Display Number
+ 2 CARD16 Length of Display Class (m)
+ m CARD8 Display Class
+</literallayout>
+
+<literallayout class="monospaced">
+<function>Refuse</function>
+ 2 CARD16 version number (always 1)
+ 2 CARD16 opcode (always Refuse)
+ 2 CARD16 length (4)
+ 4 CARD32 Session ID
+</literallayout>
+
+<literallayout class="monospaced">
+<function>Failed</function>
+ 2 CARD16 version number (always 1)
+ 2 CARD16 opcode (always Failed)
+ 2 CARD16 length (6 + m)
+ 4 CARD32 Session ID
+ 2 CARD16 Length of Status (m)
+ m CARD8 Status
+</literallayout>
+
+<literallayout class="monospaced">
+<function>KeepAlive</function>
+ 2 CARD16 version number (always 1)
+ 2 CARD16 opcode (always KeepAlive)
+ 2 CARD16 length (6)
+ 2 CARD16 Display Number
+ 4 CARD32 Session ID
+</literallayout>
+
+<literallayout class="monospaced">
+<function>Alive</function>
+ 2 CARD16 version number (always 1)
+ 2 CARD16 opcode (always Alive)
+ 2 CARD16 length (5)
+ 1 CARD8 Session Running (0: not running 1: running)
+ 4 CARD32 Session ID (0: not running)
+</literallayout>
+</chapter>
+
+<chapter id="Display_Class_Format">
+<title>Display Class Format</title>
+<!-- .XS -->
+<!-- (SN Display Class Format -->
+<!-- .XE -->
+<para>
+The Display Class field of the
+<function>Manage</function>
+packet is used by the display manager to collect common sorts of
+displays into manageable groups. This field is a string encoded of
+ISO-LATIN-1 characters in the following format:
+</para>
+
+<literallayout class="monospaced">
+<emphasis remap='I'>ManufacturerID</emphasis>-<emphasis remap='I'>ModelNumber</emphasis>
+</literallayout>
+
+<para>
+Both elements of this string must exclude characters of the set
+{ <function>-</function>,
+<function>.</function>,
+<function>:</function>,
+<function>*</function>,
+<function>?</function>,
+<emphasis remap='I'>&lt;space&gt;</emphasis> }.
+The ManufacturerID is a string that should be registered
+with the X Consortium.
+The ModelNumber is designed to identify characteristics of the display
+within the manufacturer's product line.
+This string should be documented in the users manual for the
+particular device and should probably not be specifiable by the
+display user to avoid unexpected configuration errors.
+</para>
+</chapter>
+
+<chapter id="Manufacturer_Display_ID_Format">
+<title>Manufacturer Display ID Format</title>
+<!-- .XS -->
+<!-- (SN Manufacturer Display ID Format -->
+<!-- .XE -->
+<para>
+To authenticate the manager, the display and manager will share a private
+key.
+The manager, then, must be able to discover which key to use for a
+particular device.
+The Manufacturer Display ID field of the
+<function>Request</function>
+packet is intended for this purpose. Typically, the manager host will
+contain a map between this number and the key. This field is intended to be
+unique per display, possibly the ethernet address of the display in the form:
+</para>
+
+<literallayout class="monospaced">
+-Ethernet-8:0:2b:a:f:d2
+</literallayout>
+
+<para>
+It can also be a string of the form:
+</para>
+
+<literallayout class="monospaced">
+<emphasis remap='I'>ManufacturerID</emphasis>-<emphasis remap='I'>ModelNumber</emphasis>-<emphasis remap='I'>SerialNumber</emphasis>
+</literallayout>
+
+<para>
+The ManufacturerID, ModelNumber and SerialNumber are encoded using
+ISO-LATIN-1 characters, excluding {
+<function>-</function>,
+<function>.</function>,
+<function>*</function>,
+<function>?</function>,
+<emphasis remap='I'>&lt;space&gt;</emphasis> }
+</para>
+
+<para>
+When the display is shipped to a customer, it should include both the
+Manufacturer Display ID and the private key in the documentation set.
+This information should not be modifiable by the display user.
+</para>
+
+</chapter>
+
+<chapter id="Authentication">
+<title>Authentication</title>
+<!-- .XS -->
+<!-- (SN Authentication -->
+<!-- .XE -->
+<para>
+In an environment where authentication is not needed, XDMCP can disable
+authentication by having the display send empty Authentication Name
+and Authentication Data fields in the
+<function>Request</function>
+packet.
+In this case, the manager will not attempt to authenticate itself.
+Other authentication protocols may be developed, depending on local needs.
+</para>
+
+<para>
+In an unsecure environment, the display must be able to verify that the
+source of the various packets is a trusted manager. These packets will
+contain authentication information. As an example of such a system, the
+following discussion describes the "XDM-AUTHENTICATION-1" authentication
+system. This system uses a 56-bit shared private key, and 64 bits of
+authentication data. An associated example X authorization protocol
+"XDM-AUTHORIZATION-1" will also be discussed. The 56-bit key is represented
+as a 64-bit number in network order (big endian). This means that the first
+octet in the representation will be zero. When incrementing a 64-bit value,
+the 8 octets of data will be interpreted in network order (big endian).
+That is, the last octet will be incremented, subsequent carries propogate
+towards the first octet.
+</para>
+
+<para>
+Assumptions:
+</para>
+
+<orderedlist>
+ <listitem>
+ <para>
+The display and manager share a private key. This key could be programmed
+into the display by the manufacturer and shipped with the unit. It must not
+be available from the display itself, but should allow the value to be
+modified in some way. The system administrator would be responsible for
+managing a database of terminal keys.
+ </para>
+ </listitem>
+ <listitem>
+ <para>
+The display can generate random authentication numbers.
+ </para>
+ </listitem>
+</orderedlist>
+
+<para>
+Some definitions first:
+</para>
+
+<!-- FIXME: -->
+<!-- double chk math symbols, use mathml to display them? -->
+<itemizedlist>
+ <listitem>
+ <para>
+{&variable.D;}<superscript>&variable.kappa;</superscript> = encryption of plain text D by key &variable.kappa;
+ </para>
+ </listitem>
+ <listitem>
+ <para>
+{&variable.Delta;}*<superscript>&variable.kappa;</superscript> = decryption of crypto text &variable.Delta; with key &variable.kappa;
+ </para>
+ </listitem>
+ <listitem>
+ <para>
+&variable.tau; = private key shared by display and manager
+ </para>
+ </listitem>
+ <listitem>
+ <para>
+&variable.rho; = 64 bit random number generated by display
+ </para>
+ </listitem>
+ <listitem>
+ <para>
+&variable.alpha; = authentication data in XDMCP packets
+ </para>
+ </listitem>
+ <listitem>
+ <para>
+&variable.sigma; = per-session private key, generated by manager
+ </para>
+ </listitem>
+ <listitem>
+ <para>
+&variable.beta; = authorization data
+ </para>
+ </listitem>
+</itemizedlist>
+
+<para>
+Encryption will use the Data Encryption Standard (DES, FIPS 46-3); blocks
+shorter than 64 bits will be zero-filled
+on the right to 64 bits. Blocks longer than 64 bits will use block chaining:
+</para>
+<para>
+{&variable.D;}<superscript>&variable.kappa;</superscript> = {&variable.D;<subscript>1</subscript>}<superscript>&variable.kappa;</superscript> {&variable.D;<subscript>2</subscript> xor {&variable.D;<subscript>1</subscript>}<superscript>&variable.kappa;</superscript>}<superscript>&variable.kappa;</superscript>
+</para>
+
+<para>
+The display generates the first authentication data in the
+<function>Request</function>
+packet:
+</para>
+
+<para>
+&variable.alpha;<subscript>Request</subscript> = {&variable.rho;}<superscript>&variable.tau;</superscript>
+</para>
+
+<para>
+For the <function>Accept</function>
+packet, the manager decrypts the initial message and returns
+&variable.alpha;<subscript>Accept</subscript>:
+
+</para>
+
+<para>
+&variable.rho; = {&variable.alpha;<subscript>Request</subscript>}*<superscript>&variable.tau;</superscript>
+</para>
+
+<para>
+&variable.alpha;<subscript>Accept</subscript> = { &variable.rho; + 1}<superscript>&variable.tau;</superscript>
+</para>
+
+<para>
+The <function>Accept</function>
+packet also contains the authorization intended for use by
+the X server. A description of authorization type "XDM-AUTHORIZATION-1"
+follows.
+</para>
+
+<para>
+The <function>Accept</function>
+packet contains the authorization name
+"XDM-AUTHORIZATION-1". The authorization data is the string:
+</para>
+<para>
+&variable.beta;<subscript>Accept</subscript> = {&variable.sigma;}<superscript>&variable.tau;</superscript>
+</para>
+
+<para>
+To create authorization information for connection setup with the X server
+using the XDM-AUTHORIZATION-1 authorization protocol, the client computes the
+following:
+</para>
+<para>
+&variable.N; = X client identifier
+</para>
+<para>
+&variable.T; = Current time in seconds on client host (32 bits)
+</para>
+<para>
+&variable.beta; = {&variable.rho;&variable.N;&variable.T;}<superscript>&variable.sigma;</superscript>
+</para>
+
+<para>
+For TCP connections &variable.N; is 48 bits long and contains the 32-bit IPv4 address of
+the client host followed by the 16-bit port number of the client socket.
+Formats for other connections must be registered.
+The resulting value, &variable.beta;, is 192 bits of authorization data that is sent
+in the connection setup to the server. The server receives the packet,
+decrypts the contents. To accept the connection, the following must hold:
+</para>
+
+<itemizedlist>
+ <listitem>
+ <para>
+&variable.rho; must match the value generated for the most recent XDMCP negotiation.
+ </para>
+ </listitem>
+ <listitem>
+ <para>
+&variable.T; must be within 1200 seconds of the internally stored time. If no time
+been received before, the current time is set to &variable.T;.
+ </para>
+ </listitem>
+ <listitem>
+ <para>
+No packet containing the same pair (&variable.N;, &variable.T;) can have been received
+in the last 1200 seconds (20 minutes).
+ </para>
+ </listitem>
+</itemizedlist>
+</chapter>
+</book>
diff --git a/libXdmcp/docbook.am b/libXdmcp/docbook.am
index 2ffb7e60a..bba4d5453 100644
--- a/libXdmcp/docbook.am
+++ b/libXdmcp/docbook.am
@@ -21,74 +21,82 @@ shelf_DATA =
dist_shelf_DATA = $(docbook) $(chapters)
if HAVE_XMLTO
-#
-# Generate DocBook/XML output formats with or without stylesheets
-#
-
-# Stylesheets are available if the package xorg-sgml-doctools is installed
if HAVE_STYLESHEETS
-# The location where all cross reference databases are installed
-sgmldbsdir = $(XORG_SGML_PATH)/X11/dbs
-masterdb = "$(sgmldbsdir)/masterdb$(suffix $@).xml"
-XMLTO_FLAGS = \
- --searchpath "$(XORG_SGML_PATH)/X11" \
- --stringparam target.database.document=$(masterdb) \
- --stringparam current.docid="$(<:.xml=)" \
- --stringparam collect.xref.targets="no"
-
-XMLTO_XHTML_FLAGS = \
- -x $(STYLESHEET_SRCDIR)/xorg-xhtml.xsl \
- --stringparam html.stylesheet=$(STYLESHEET_SRCDIR)/xorg.css
-
-XMLTO_FO_FLAGS = \
- -x $(STYLESHEET_SRCDIR)/xorg-fo.xsl
-endif HAVE_STYLESHEETS
+XMLTO_SEARCHPATH_FLAGS = \
+ --searchpath "$(XORG_SGML_PATH)/X11" \
+ --searchpath "$(abs_top_builddir)"
+XMLTO_HTML_OLINK_FLAGS = \
+ --stringparam target.database.document=$(XORG_SGML_PATH)/X11/dbs/masterdb.html.xml \
+ --stringparam current.docid="$(<:.xml=)"
+XMLTO_HTML_STYLESHEET_FLAGS = -x $(STYLESHEET_SRCDIR)/xorg-xhtml.xsl
+XMLTO_HTML_FLAGS = \
+ $(XMLTO_SEARCHPATH_FLAGS) \
+ $(XMLTO_HTML_STYLESHEET_FLAGS) \
+ $(XMLTO_HTML_OLINK_FLAGS)
shelf_DATA += $(docbook:.xml=.html)
-%.html: %.xml $(chapters)
- $(AM_V_GEN)$(XMLTO) $(XMLTO_FLAGS) $(XMLTO_XHTML_FLAGS) xhtml-nochunks $<
-
-if HAVE_FOP
-shelf_DATA += $(docbook:.xml=.pdf) $(docbook:.xml=.ps)
-%.pdf: %.xml $(chapters)
- $(AM_V_GEN)$(XMLTO) $(XMLTO_FLAGS) $(XMLTO_FO_FLAGS) --with-fop pdf $<
-%.ps: %.xml $(chapters)
- $(AM_V_GEN)$(XMLTO) $(XMLTO_FLAGS) $(XMLTO_FO_FLAGS) --with-fop ps $<
-endif HAVE_FOP
+%.html: %.xml $(chapters)
+ $(AM_V_GEN)$(XMLTO) $(XMLTO_HTML_FLAGS) xhtml-nochunks $<
if HAVE_XMLTO_TEXT
+
shelf_DATA += $(docbook:.xml=.txt)
%.txt: %.xml $(chapters)
- $(AM_V_GEN)$(XMLTO) $(XMLTO_FLAGS) $(XMLTO_XHTML_FLAGS) txt $<
+ $(AM_V_GEN)$(XMLTO) $(XMLTO_HTML_FLAGS) txt $<
endif HAVE_XMLTO_TEXT
-#
-# Generate documents cross-reference target databases
-#
+if HAVE_FOP
+XMLTO_FO_IMAGEPATH_FLAGS = --stringparam img.src.path=$(abs_builddir)/
+XMLTO_PDF_OLINK_FLAGS = \
+ --stringparam target.database.document=$(XORG_SGML_PATH)/X11/dbs/masterdb.pdf.xml \
+ --stringparam current.docid="$(<:.xml=)"
+XMLTO_FO_STYLESHEET_FLAGS = -x $(STYLESHEET_SRCDIR)/xorg-fo.xsl
+
+XMLTO_FO_FLAGS = \
+ $(XMLTO_SEARCHPATH_FLAGS) \
+ $(XMLTO_FO_STYLESHEET_FLAGS) \
+ $(XMLTO_FO_IMAGEPATH_FLAGS) \
+ $(XMLTO_PDF_OLINK_FLAGS)
+
+shelf_DATA += $(docbook:.xml=.pdf)
+%.pdf: %.xml $(chapters)
+ $(AM_V_GEN)$(XMLTO) $(XMLTO_FO_FLAGS) --with-fop pdf $<
-# This is only possible if the xorg-sgml-doctools package is installed
-if HAVE_STYLESHEETS
-if HAVE_XSLTPROC
+shelf_DATA += $(docbook:.xml=.ps)
+%.ps: %.xml $(chapters)
+ $(AM_V_GEN)$(XMLTO) $(XMLTO_FO_FLAGS) --with-fop ps $<
+endif HAVE_FOP
-# DocBook/XML generated document cross-reference database
-shelf_DATA += $(docbook:.xml=.html.db) $(docbook:.xml=.fo.db)
+# Generate documents cross-reference target databases
+if HAVE_XSLTPROC
-# Generate DocBook/XML document cross-reference database
-# Flags for the XSL Transformation processor generating xref target databases
-XSLTPROC_FLAGS = \
+XSLT_SEARCHPATH_FLAGS = \
--path "$(XORG_SGML_PATH)/X11" \
- --stringparam targets.filename "$@" \
- --stringparam collect.xref.targets "only" \
- --nonet --xinclude
-
+ --path "$(abs_top_builddir)"
+XSLT_OLINK_FLAGS = \
+ --stringparam targets.filename "$@" \
+ --stringparam collect.xref.targets "only" \
+ --stringparam olink.base.uri "$(@:.db=)"
+
+XSLT_HTML_FLAGS = \
+ $(XSLT_SEARCHPATH_FLAGS) \
+ $(XSLT_OLINK_FLAGS) \
+ --nonet --xinclude \
+ $(STYLESHEET_SRCDIR)/xorg-xhtml.xsl
+XSLT_PDF_FLAGS = \
+ $(XSLT_SEARCHPATH_FLAGS) \
+ $(XSLT_OLINK_FLAGS) \
+ --nonet --xinclude \
+ $(STYLESHEET_SRCDIR)/xorg-fo.xsl
+
+shelf_DATA += $(docbook:.xml=.html.db)
%.html.db: %.xml $(chapters)
- $(AM_V_GEN)$(XSLTPROC) $(XSLTPROC_FLAGS) \
- http://docbook.sourceforge.net/release/xsl/current/xhtml/docbook.xsl $<
+ $(AM_V_GEN)$(XSLTPROC) $(XSLT_HTML_FLAGS) $<
-%.fo.db: %.xml $(chapters)
- $(AM_V_GEN)$(XSLTPROC) $(XSLTPROC_FLAGS) \
- http://docbook.sourceforge.net/release/xsl/current/fo/docbook.xsl $<
+shelf_DATA += $(docbook:.xml=.pdf.db)
+%.pdf.db: %.xml $(chapters)
+ $(AM_V_GEN)$(XSLTPROC) $(XSLT_PDF_FLAGS) $<
endif HAVE_XSLTPROC
endif HAVE_STYLESHEETS
generated by cgit v1.2.3 (git 2.25.1) at 2024-11-22 03:38:50 +0000