Tribblix: manual page: x0vncserver.1

X0VNCSERVER(1) TigerVNC Manual X0VNCSERVER(1)

NAME

x0vncserver - TigerVNC Server for X displays

SYNOPSIS

x0vncserver [options]
x0vncserver -version

DESCRIPTION

x0vncserver is a TigerVNC Server which makes any X display remotely
accessible via VNC, TigerVNC or compatible viewers. Unlike Xvnc(1),
it does not create a virtual display. Instead, it just shares an
existing X server (typically, that one connected to the physical
screen).

XDamage will be used if the existing X server supports it. Otherwise
x0vncserver will fall back to polling the screen for changes.

OPTIONS

x0vncserver interprets the command line as a list of parameters with
optional values. Running x0vncserver -h will show a list of all
valid parameters with short descriptions. All parameters are
optional, but normally you would have to use the PasswordFile
parameter (see its description below).

There are several forms of specifying parameters in the command line
(here we use `SomeParameter' as an example parameter name):

-SomeParameter
Enable the parameter, turn the feature on. This form can be
used with parameters that simply enable or disable some
feature.

-SomeParameter=0
Disable the parameter, turn the feature off.

-SomeParameter=value
Assign the specified value to the parameter. The leading dash
can be omitted, or it can be doubled if desired (like in GNU-
style long options).

Parameter names are case-insensitive, their order in the command line
can be arbitrary.

PARAMETERS

-display display
The X display name. If not specified, it defaults to the
value of the DISPLAY environment variable.

-rfbport port
Specifies the TCP port on which x0vncserver listens for
connections from viewers (the protocol used in VNC is called
RFB - "remote framebuffer"). The default port is 5900.

-UseIPv4
Use IPv4 for incoming and outgoing connections. Default is on.

-UseIPv6
Use IPv6 for incoming and outgoing connections. Default is on.

-rfbunixpath path
Specifies the path of a Unix domain socket on which
x0vncserver listens for connections from viewers, instead of
listening on a TCP port.

-rfbunixmode mode
Specifies the mode of the Unix domain socket. The default is
0600.

-Log logname:dest:level
Configures the debug log settings. dest can currently be
stderr, stdout or syslog, and level is between 0 and 100, 100
meaning most verbose output. logname is usually * meaning
all, but you can target a specific source file if you know the
name of its "LogWriter". Default is *:stderr:30.

-HostsFile filename
This parameter allows to specify a file name with IP access
control rules. The file should include one rule per line, and
the rule format is one of the following: +address/prefix
(accept connections from the specified address group),
-address/prefix (reject connections) or ?address/prefix (query
the local user). The first rule matching the IP address
determines the action to be performed. Rules that include
only an action sign (+, - or ?) will match any IP address.
Prefix is optional and is specified as a number of bits (e.g.
/24). Default is to accept connections from any IP address.

-SecurityTypes sec-types
Specify which security scheme to use for incoming connections.
Valid values are a comma separated list of None, VncAuth,
Plain, TLSNone, TLSVnc, TLSPlain, X509None, X509Vnc and
X509Plain. Default is VncAuth,TLSVnc.

-rfbauth passwd-file, -PasswordFile passwd-file
Password file for VNC authentication. There is no default,
you should specify the password file explicitly. Password
file should be created with the vncpasswd(1) utility. The
file is accessed each time a connection comes in, so it can be
changed on the fly.

-Password password
Obfuscated binary encoding of the password which clients must
supply to access the server. Using this parameter is
insecure, use PasswordFile parameter instead.

-PlainUsers user-list
A comma separated list of user names that are allowed to
authenticate via any of the "Plain" security types (Plain,
TLSPlain, etc.). Specify * to allow any user to authenticate
using this security type. Default is to deny all users.

-pam_service name, -PAMService name
PAM service name to use when authentication users using any of
the "Plain" security types. Default is vnc.

-X509Cert path
Path to a X509 certificate in PEM format to be used for all
X509 based security types (X509None, X509Vnc, etc.).

-X509Key path
Private key counter part to the certificate given in X509Cert.
Must also be in PEM format.

-GnuTLSPriority priority
GnuTLS priority string that controls the TLS session's
handshake algorithms. See the GnuTLS manual for possible
values. Default is NORMAL.

-UseBlacklist
Temporarily reject connections from a host if it repeatedly
fails to authenticate. Default is on.

-BlacklistThreshold count
The number of unauthenticated connection attempts allowed from
any individual host before that host is black-listed. Default
is 5.

-BlacklistTimeout seconds
The initial timeout applied when a host is first black-listed.
The host cannot re-attempt a connection until the timeout
expires. Default is 10.

-QueryConnect
Prompts the user of the desktop to explicitly accept or reject
incoming connections. Default is off.

-QueryConnectTimeout seconds
Number of seconds to show the Accept Connection dialog before
rejecting the connection. Default is 10.

-localhost
Only allow connections from the same machine. Useful if you
use SSH and want to stop non-SSH connections from any other
hosts.

-AlwaysShared
Always treat incoming connections as shared, regardless of the
client-specified setting. Default is off.

-NeverShared
Never treat incoming connections as shared, regardless of the
client-specified setting. Default is off.

-DisconnectClients
Disconnect existing clients if an incoming connection is non-
shared. Default is on. If DisconnectClients is false, then a
new non-shared connection will be refused while there is a
client active. When combined with NeverShared this means only
one client is allowed at a time.

-AcceptKeyEvents
Accept key press and release events from clients. Default is
on.

-AcceptPointerEvents
Accept pointer press and release events from clients. Default
is on.

-AcceptSetDesktopSize
Accept requests to resize the size of the desktop. Default is
on.

-RemapKeys mapping
Sets up a keyboard mapping. mapping is a comma-separated
string of character mappings, each of the form char->char, or
char<>char, where char is a hexadecimal keysym. For example,
to exchange the " and @ symbols you would specify the
following:

RemapKeys=0x22<>0x40

-RawKeyboard
Send keyboard events straight through and avoid mapping them
to the current keyboard layout. This effectively makes the
keyboard behave according to the layout configured on the
server instead of the layout configured on the client. Default
is off.

-Protocol3.3
Always use protocol version 3.3 for backwards compatibility
with badly-behaved clients. Default is off.

-Geometry geometry
This option specifies the screen area that will be shown to
VNC clients. The format is widthxheight+xoffset+yoffset ,
where `+' signs can be replaced with `-' signs to specify
offsets from the right and/or from the bottom of the screen.
Offsets are optional, +0+0 is assumed by default (top left
corner). If the argument is empty, full screen is shown to
VNC clients (this is the default).

-MaxProcessorUsage percent
Maximum percentage of CPU time to be consumed when polling the
screen. Default is 35.

-PollingCycle milliseconds
Milliseconds per one polling cycle. Actual interval may be
dynamically adjusted to satisfy MaxProcessorUsage setting.
Default is 30.

-FrameRate fps
The maximum number of updates per second sent to each client.
If the screen updates any faster then those changes will be
aggregated and sent in a single update to the client. Note
that this only controls the maximum rate and a client may get
a lower rate when resources are limited. Default is 60.

-CompareFB mode
Perform pixel comparison on framebuffer to reduce unnecessary
updates. Can be either 0 (off), 1 (always) or 2 (auto).
Default is 2.

-UseSHM
Use MIT-SHM extension if available. Using that extension
accelerates reading the screen. Default is on.

-ZlibLevel level
Zlib compression level for ZRLE encoding (it does not affect
Tight encoding). Acceptable values are between 0 and 9.
Default is to use the standard compression level provided by
the zlib(3) compression library.

-ImprovedHextile
Use improved compression algorithm for Hextile encoding which
achieves better compression ratios by the cost of using
slightly more CPU time. Default is on.

-IdleTimeout seconds
The number of seconds after which an idle VNC connection will
be dropped. Default is 0, which means that idle connections
will never be dropped.

-MaxDisconnectionTime seconds
Terminate when no client has been connected for N seconds.
Default is 0.

-MaxConnectionTime seconds
Terminate when a client has been connected for N seconds.
Default is 0.

-MaxIdleTime seconds
Terminate after N seconds of user inactivity. Default is 0.

-ClientWaitTimeMillis time
Time in milliseconds to wait for a viewer which is blocking
the server. This is necessary because the server is single-
threaded and sometimes blocks until the viewer has finished
sending or receiving a message - note that this does not mean
an update will be aborted after this time. Default is 20000
(20 seconds).

-AcceptCutText
-SendCutText
-MaxCutText
Currently unused.

AUTHOR