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Version 17 (modified by Antoine Martin, 6 years ago) (diff)

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Network Protocol

Introduction

This page documents the types of messages that the client and server can exchange. For the actual network connection see wiki/Network and for the encoding and compression of the messages see wiki/PacketEncoding.
The most important packet is the first one sent, the hello packet, since it contains "capabilities" which determines what packets and features are supported by the other end. In a lot of cases, a client which does not implement all the features should disable the capability rather than ignoring the corresponding packets.


The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this document are to be interpreted as described in RFC 2119.


  • General packets that flow in both directions:
Packet Type Arguments Purpose Actions Required
helloa dictionary containing connection options and capabilitiesauthentication (if required), setup of keyboard, configuration options, etcthe receiver must either accept the connection and send a hello back as acknowledgement, send a challenge request or disconnect
pingtime to be echoed backmonitor connection state, collect latency statisticsThe receiver must send a ping-echo back
ping-echoechoed time, load average, measured latencyresponse to pingnone, it should be used to collect latency statistics
sound-datasound buffers and associated metadataforward sound datathe receiver should queue the sound buffer, it may drop them if desired - if so, it should tell the other end to stop sending
connection-lostnonesent by the network layer when the network connection has droppedfree any resources
gibberishnonesent by the network layer when the network received unparseable data, data decompression failed or decryption faileddisconnect the connection and free any resources




  • Packets sent by the server
Packet Type Arguments Purpose Actions Required Client Capability Required
startup-completenonenotifies the client that all the windows have been sentnonenotify-startup-complete
new-window and
new-override-redirect
window ID and attributestells the client about a new regular window or override-redirect windowthe client should show the new window, it should eventually send a map-window packet with the location of the windownone
new-traywindow ID and attributestells the client about a new tray windowthe client should show the new system traysystem_tray
lost-windowwindow IDthe application has closed the given windowthe client must close the given window or tray, which can not longer be usednone
raise-windowwindow IDthe application has requested that the window be raisedthe client should raise the windowwindow.raise
configure-override-redirectwindow ID, new position and sizehonour applications that reconfigure their override redirect windowsthe client must move and resize the windownone
window-move-resizewindow ID, new position and sizehonour applications that request the window to be moved and resizedthe client should move and resize the windowserver-window-move-resize
window-resizedwindow ID and new sizehonour applications that request the window to be resized - this is only a deprecated fallback for window-move-resizethe client should move and resize the windowserver-window-resize
window-iconwindow ID and icon datanew icon for the given windowthe client may display this new icon in the window's title bar, etcraw_window_icons
window-metadatawindow ID and metadata dictionaryupdate the metadata associated with a windowthe client should apply the new attributes to the given windownone
cursorthe cursor data (see code for details)honour applications that request a different cursorthe client should display the new cursor immediatelycursors
bellthe bell sound definition (see code for details)honour applications requesting the bell to ringthe client should ring the "bell" or its equivallentbell
notify_shownotification ID, message, etchonour applications which request that a notification be shown to the userthe client should show the notificationnotifications
notify_closenotification IDthe notification should be closedthe client should stop showing the given notificationnotifications
set-clipboard-enablednew state, reason for changethe server requests that clipboard synchronization be turned on or offthe client should honour the requestclipboard.set_enabled
desktop_sizedimensionsthe server has resized the virtual displaythe client may record and use these new dimensionsnone
drawposition of the update within the window and the pixel dataan area of the window must be re-paintedthe client must repaint the window with the new pixel datanone
rpc-replyrpc responsethe server is responding to a rpc packetthe client should be able to match the response to a query it sent (only dbus rpc is supported at present)dbus_proxy
controlcontrol command and argumentsthe server is requesting a configuration changethe client may honour itcontrol_commands (list)




  • Packets sent by the client
Packet Type Arguments Purpose Actions Required Server Capability Required
set-clipboard-enablednew stateenable or disable clipboard synchronizationthe server should honour the requestclipboard
set-keyboard-sync-enablednew stateenable or disable keyboard synchronizationthe server should honour the requesttoggle_keyboard_sync
set-cursorsnew stateenable or disable sending of cursor datathe server should honour the requesttoggle_cursors_bell_notify
set-notifynew stateenable or disable sending of notificationsthe server should honour the requesttoggle_cursors_bell_notify
set-bellnew stateenable or disable sending of bell eventsthe server should honour the requesttoggle_cursors_bell_notify
map-windowwindow ID, position and propertiestells the server where the window has been mapped on the clientthe server must ensure its window is at the same locationnone
unmap-windowwindow IDthe window is no longer shownthe server should do the same and park the windownone
configure-windowwindow ID, position, size and propertiesthe client has modified the window in some waythe server must ensure its window matchesnone
close-windowwindow IDthe client has requested that the window be closedthe server should ask the application to close the window, it may force it to do sonone
focuswindow ID and keyboard statethe client has focused a different window, or none at allthe server should ensure its focus state matchesnone
button-actionwindow ID, button, pressed or unpressed, position and keyboard modifiers statethe client has clicked on a window (or used the mouse wheel)the server should try to simulate pressing or unpressing the same buttonnone
pointer-positionwindow ID, position and keyboard modifiers statethe user is moving its mouse over a windowthe server should try to move its mouse to the same positionnone
key-actionkey definition (keycode, key name, pressed or unpressed, etc)the user has pressed a keythe server should try to simulate pressing the same keynone
key-repeatkey definition (as above)the key is still pressedthe server may use this information to continue pressing the same key, cancelling any timeouts it may have - this is only relevant when the keyboard state is synchronizednone
layout-changedlayout and variantthe client keyboard configuration has changedthe server should try to update its keyboard configuration to matchnone
keymap-changeda dictionary of keyboard definitionsthe client keyboard configuration has changedthe server should try to update its keyboard configuration to matchnone
damage-sequencesequence ID and decoding detailsthe client is acknowledging that it has painted a screen update received in a draw packetthe server may use this information to estimate the performance of the connection and of the client, and may decide to send more screen updatesnone
server-settingssettingsthe client's xsettings have changedthe server should apply the new settingsnone
jpeg-quality (deprecated) or
quality
new fixed picture quality value from -1 to 100the client wants to use a fixed quality (0 to 100), or disable fixed quality (-1)the server should honour the request, it may refresh all the windows with the new settingnone
min-qualitynew minimum picture quality value
speednew fixed speed value from -1 to 100the client wants to use a fixed speed (0 to 100), or disable fixed speed (-1)the server should honour the request, it may refresh all the windows with the new settingnone
min-speednew minimum speed setting

TODO: undocumented:

set_deflate
desktop_size
encoding
suspend
resume
rpc
sound-control
shutdown-server
exit-server
buffer-refresh
screenshot
disconnect