LBXPROXY(1)LBXPROXY(1)NAMElbxproxy - Low BandWidth X proxy
SYNOPSISlbxproxy [:<display>] [option]
DESCRIPTION
Applications that would like to take advantage of the Low
Bandwidth extension to X (LBX) must make their connections
to an lbxproxy. These applications need to know nothing
about LBX, they simply connect to the lbxproxy as if were
a regular server. The lbxproxy accepts client connec-
tions, multiplexes them over a single connection to the X
server, and performs various optimizations on the X proto-
col to make it faster over low bandwidth and/or high
latency connections.
With regard to authentication/authorization, lbxproxy sim-
ply passes along to the server the credentials presented
by the client. Since X clients will connect to lbxproxy,
it is important that the user's .Xauthority file contain
entries with valid keys associated with the network ID of
the proxy. lbxproxy does not get involved with how these
entries are added to the .Xauthority file. The user is
responsible for setting it up.
The lbxproxy program has various options, all of which are
optional.
If :<display> is specified, the proxy will use the given
display port when listening for connections. The display
port is an offset from port 6000, identical to the way in
which regular X display connections are specified. If no
port is specified on the command line option, lbxproxy
will default to port 63. If the port number that the
proxy tries to listen on is in use, the proxy will attempt
to use another port number. If the proxy is not using the
Proxy Manager and the default port number cannot be used,
the port number that is used will be written to stderr.
The other command line options that can be specified are:
-help Prints a brief help message about the command line
options.
-display dpy
Specifies the address of the X server supporting
the LBX extension. If this option is not speci-
fied, the display is obtained by the DISPLAY envi-
ronment variable.
-motion count
A limited number of pointer motion events are
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allowed to be in flight between the server and the
proxy at any given time. The maximimum number of
motion events that can be in flight is set with
this option; the default is 8.
-maxservers number
The default behavior of lbxproxy is to manage a
single server. However, lbxproxy can manage more
than one server. The default maximum number of
servers is 20. The number of servers can be over-
ridden by setting the environment variable LBX-
PROXY_MAXSERVERS to the desired number. The order
of precedence from highest to lowest: command
line, environment variable, default number.
-[terminate|reset]
The default behavior of lbxproxy is to continue
running as usual when it's last client exits. The
-terminate option will cause lbxproxy to exit when
the last client exits. The -reset option will
cause lbxproxy to reset itself when the last
client exits. Resetting causes lbxproxy to clean
up it's state and reconnect to the server.
-reconnect
The default behavior of lbxproxy is to exit when
its connection to the server is broken. The
-reconnect option will cause lbxproxy to just
reset instead (see -reset above) and attempt to
reconnect to the server.
-I Causes all remaining arguments to be ignored.
-nolbx Disables all LBX optimizations.
-nocomp Disables stream compression.
-nodelta
Disables delta request substitutions.
-notags Disables usage of tags.
-nogfx Disables reencoding of graphics requests (not
including image related requests).
-noimage
Disables image compression.
-nosquish
Disables squishing of X events.
-nointernsc
Disables short circuiting of InternAtom requests.
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LBXPROXY(1)LBXPROXY(1)-noatomsfile
Disables reading of the atoms control file. See
the section on "Atom Control" for more details.
-atomsfile file
Overrides the default AtomControl file. See the
section on "Atom Control" for more details.
-nowinattr
Disables GetWindowAttributes/GetGeometry grouping
into one round trip.
-nograbcmap
Disables colormap grabbing.
-norgbfile
Disables color name to RGB resolution in proxy.
-rgbfile path
Specifies an alternate RGB database for color name
to RGB resolution.
-tagcachesize
Set the size of the proxy's tag cache (in bytes).
-zlevel level
Set the Zlib compression level (used for stream
compression).
default is 6
1 = worst compression, fastest
9 = best compression, slowest
-compstats
Report stream compression statistics every time
the proxy resets or receives a SIGHUP signal.
-nozeropad
Don't zero out unused pad bytes in X requests,
replies, and events.
-cheaterrors
Allows cheating on X protocol for the sake of
improved performance. The X protocol guarantees
that any replies, events or errors generated by a
previous request will be sent before those of a
later request. This puts substantial restrictions
on when lbxproxy can short circuit a request. The
-cheaterrors option allows lbxproxy to violate X
protocol rules with respect to errors. Use at
your own risk.
-cheatevents
The -cheatevents option allows lbxproxy to violate
X protocol rules with respect to events as well as
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errors. Use at your own risk.
ATOM CONTROL
At startup, lbxproxy "pre-interns" a configurable list of
atoms. This allows lbxproxy to intern a group of atoms in
a single round trip and immediately store the results in
its cache.
While running, lbxproxy uses heuristics to decide when to
delay sending window property data to the server. The
heuristics depend on the size of the data, the name of the
property, and whether a window manager is running through
the same lbxproxy.
Atom control is specified in the "AtomControl" file, set
up during installation of lbxproxy, with command line
overrides.
The file is a simple text file. There are three forms of
lines: comments, length control, and name control. Lines
starting with a '!' are treated as comments. A line of
the form
z length
specifies the minimum length in bytes before property data
will be delayed. A line of the form
options atomname
controls the given atom, where options is any combination
of the following characters: 'i' means the atom should be
pre-interned; and 'w' means data for properties with this
name should be delayed only if a window manager is also
running through the same lbxproxy.
BUGS
When the authorization protocol XDM-AUTHORIZATION-1 is
used:
A client must be on the same host as lbxproxy for the
client to be authorized to connect to the server.
If a client is not on the same host as lbxproxy, the
client will not be authorized to connect to the
server.
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