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1551 lines
41 KiB
1551 lines
41 KiB
#!/usr/bin/perl
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#
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##########################################################################
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# desktop.cgi:
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#
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# This is an example CGI script to provide multi-user web access to
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# x11vnc desktops. The user desktop sessions run in 'Xvfb' displays
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# that are created automatically.
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#
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# This script should/must be served by an HTTPS (i.e. SSL) webserver,
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# otherwise the unix and vnc passwords would be sent over the network
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# unencrypted (see below to disable if you really want to.)
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#
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# The Java VNC Viewer applet connections are encrypted by SSL as well.
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#
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# You can use this script to provide unix users desktops available on
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# demand via any Java enabled web browser. One could also use this for
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# a special-purpose 'single application' service running in a minimal
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# window manager.
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#
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# One example of a special-purpose application would be a scientific
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# data visualization tool running on a server where the data is housed.
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# To do this set $x11vnc_extra_opts = '-env FD_PROG=/path/to/app/launcher'
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# where the program launches your special purpose application. A very
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# simple example: '-env FD_PROG=/usr/bin/xclock'
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#
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#
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# Depending on where you place this script, the user accesses the service
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# with the URL:
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#
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# https://your.webserver.net/cgi-bin/desktop.cgi
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#
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# Then they login with their unix username and password to get their
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# own desktop session.
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#
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# If the user has an existing desktop it is connected to directly,
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# otherwise a new session is created inside an Xvfb display and then
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# connected to by VNC.
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#
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# It is possible to do port redirection to other machines running SSL
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# enabled VNC servers (see below.) This script does not start the VNC
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# servers on the other machines, although with some extra rigging you
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# should be able to do that as well.
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#
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# You can customize the login procedure to whatever you want by modifying
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# this script, or by using ideas in this script write your own PHP,
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# (for example), script.
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#
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##########################################################################
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# Overriding default settings:
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#
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# If you want to override any settings in this script and do not
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# want to edit this script create the assignments in a file named
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# 'desktop.cgi.conf' in the same directory as desktop.cgi. It will be
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# sourced after the defaults are set. The format of desktop.cgi.conf
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# is simply perl statements that make the assignments.
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#
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# For example, if you put something like this in desktop.cgi.conf:
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#
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# $x11vnc = '/usr/local/bin/x11vnc';
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#
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# that will set the path to the x11vnc binary to that location. Look at
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# the settings below for the other variables that you can modify, for
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# example one could set $allowed_users_file.
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#
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##########################################################################
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# x11vnc:
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#
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# You need to install x11vnc or otherwise have it available. It is
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# REQUIRED that you use x11vnc 0.9.10 or later. It won't work with
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# earlier versions. See below the $x11vnc parameter that you can set
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# to the full path to x11vnc.
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#
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##########################################################################
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# Xvfb:
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#
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# Note that the x11vnc -create virtual desktop service used below requires
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# that you install the 'Xvfb' program. On debian this is currently done
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# via 'apt-get install xvfb'.
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#
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# If you are having trouble getting 'x11vnc -create' to work with this
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# script (it can be tricky), try it manually and/or see the x11vnc FAQ
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# links below.
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#
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##########################################################################
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# Apache httpd:
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#
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# You should put this script in, say, a cgi-bin directory. Enable cgi
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# scripts in your apache (or other httpd) config. For example, we have
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# these lines (not commented):
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#
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# In httpd.conf:
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#
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# ScriptAlias /cgi-bin/ "/dist/apache/2.0/cgi-bin/"
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#
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# <Directory "/dist/apache/2.0/cgi-bin">
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# AllowOverride None
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# Options None
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# Order allow,deny
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# Allow from all
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# </Directory>
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#
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# and in ssl.conf:
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#
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# <Directory "/dist/apache/2.0/cgi-bin">
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# SSLOptions +StdEnvVars
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# </Directory>
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#
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# Do not be confused by the non-standard /dist/apache/2.0 apache
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# installation location that we happen to use. Yours will be different.
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#
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# You can test that you have CGI scripts working properly with the
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# 'test-cgi' and 'printenv' scripts apache provides.
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#
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# Copy this file (desktop.cgi) to /dist/apache/2.0/cgi-bin and then run
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# 'chmod 755 ...' on it to make it executable.
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#
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##########################################################################
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# Applet Jar files served by apache:
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#
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# You will *also* need to copy the x11vnc classes/ssl/UltraViewerSSL.jar
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# file to the httpd DocumentRoot to be accessible by: /UltraViewerSSL.jar
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# in a URL (or change $applet_jar below or the html in $applet_html if
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# you want to use a different location.)
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#
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# This location is relative to the apache DocumentRoot 'htdocs' directory.
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# For our (non-standard location installation) that meant we copied the
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# file to:
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#
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# /dist/apache/2.0/htdocs/UltraViewerSSL.jar
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#
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# (your DocumentRoot directory will be different.)
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#
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# The VncViewer.jar (tightvnc) will also work, but you need to change
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# the $applet_jar below. You can get these jar files from the x11vnc
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# tarball from:
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#
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# http://www.karlrunge.com/x11vnc/#downloading
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#
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# This script requires x11vnc 0.9.10 or later.
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#
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# Note that the usage mode for this script is a different from regular
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# 'x11vnc -http ...' usage where x11vnc acts as a mini web server and
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# serves its own applet jars. We don't use that mode for this script.
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# Apache (httpd) serves the jars.
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#
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#
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##########################################################################
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# Notes and Information:
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#
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# Each x11vnc server created for a user login will listen on its own port
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# (see below for port selection schemes.) Your firewall must let in *ALL*
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# of these ports (e.g. a port range, see below for the syntax.)
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#
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# It is also possible, although not as reliable, to do all of this through
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# a single port, see the fixed port scheme $find_free_port = 'fixed:5910'
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# below. This single port mode must be different from apache's port
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# (usually 443 for https) and must also be allowed in by your firewall.
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#
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# Note: The fixed port scheme is DISABLED by default.
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#
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# It is also possible to have this script act as a vnc redirector to SSL
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# enabled VNC servers running on *other* machines inside your firewall
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# (presumably the users' desktops) See the $enable_port_redirection
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# setting below. The user provides 'username@host:port' instead of just
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# 'username' when she logs in. This script doesn't start VNC servers
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# on those other machines, the servers must be running there already.
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# (If you want this script to start them you will need to add it
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# yourself.) It is possible to provide a host:port allow list to limit
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# which internal machines and ports can be redirected to. This is the
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# $port_redirection_allowed_hosts parameter.
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#
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# Note: The vnc redirector scheme is DISABLED by default.
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#
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# Note there are *two* SSL certificates involved that the user may be
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# asked to inspect: apache's SSL cert and x11vnc's SSL cert. This may
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# confuse naive users. You may want to use the same cert for both.
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#
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# This script provides one example on how to provide the service. You can
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# customize it to meet your needs, e.g. switch to php, newer cgi modules,
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# different authentication, SQL database for user authentication, etc,
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# etc. If you plan to use it in production, please examine all security
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# aspects of it carefully; read the comments in the script for more info.
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#
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# More information and background and troubleshooting:
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#
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# http://www.karlrunge.com/x11vnc/faq.html#faq-xvfb
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# http://www.karlrunge.com/x11vnc/faq.html#faq-ssl-tunnel-viewers
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# http://www.karlrunge.com/x11vnc/faq.html#faq-ssl-java-viewer-proxy
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# http://www.karlrunge.com/x11vnc/faq.html#faq-ssl-portal
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# http://www.karlrunge.com/x11vnc/faq.html#faq-unix-passwords
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# http://www.karlrunge.com/x11vnc/faq.html#faq-userlogin
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#
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#
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# Please also read the comments below for changing specific settings.
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# You can modify them in this script or by override file 'desktop.cgi.conf'
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#-------------------------------------------------------------------------
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# Copyright (c) 2010 by Karl J. Runge <runge@karlrunge.com>
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#
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# desktop.cgi is free software; you can redistribute it and/or modify
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# it under the terms of the GNU General Public License as published by
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# the Free Software Foundation; either version 2 of the License, or (at
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# your option) any later version.
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#
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# desktop.cgi is distributed in the hope that it will be useful,
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# but WITHOUT ANY WARRANTY; without even the implied warranty of
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# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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# GNU General Public License for more details.
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#
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# You should have received a copy of the GNU General Public License
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# along with desktop.cgi; if not, write to the Free Software
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# Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA
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# or see <http://www.gnu.org/licenses/>.
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#-------------------------------------------------------------------------
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use strict;
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use IO::Socket::INET;
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# Test for INET6 support:
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#
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my $have_inet6 = 0;
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eval "use IO::Socket::INET6;";
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$have_inet6 = 1 if $@ eq "";
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##########################################################################
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# Path to the x11vnc program:
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#
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my $x11vnc = '/usr/bin/x11vnc';
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##########################################################################
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# You can set some extra x11vnc cmdline options here:
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#
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my $x11vnc_extra_opts = '';
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##########################################################################
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# Override the default x11vnc viewer connection timeout of 75 seconds:
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#
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my $x11vnc_timeout = '';
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##########################################################################
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# TCP Ports:
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#
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# Set find_free_port to 1 (or the other modes described below) to
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# autoselect a free port to use. The default is to use a port based on
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# the userid number (7000 + uid).
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#
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my $find_free_port = 0;
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# Or specify a port range:
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#
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#$find_free_port = '7000-8000';
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#
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# Or indicate to use a kludge to try to do everything through a SINGLE
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# port. To try to avoid contention on the port, simultaneous instances
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# of this script attempt to 'take turns' using it the single port.
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#
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#$find_free_port = 'fixed:5910';
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# This is the starting port for 7000 + uid and also $find_free_port = 1
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# autoselection:
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#
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my $starting_port = 7000;
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# Listen on AF_INET6 if IO::Socket::INET6 is available.
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#
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my $listen_on_ipv6 = 0;
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##########################################################################
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# Port redirection mode:
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#
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# This is to enable port redirection mode: username@host:port. If
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# username is valid, there will be a port redirection to internal machine
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# host:port. Presumably there is already an SSL enabled and password
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# protected VNC server running there. We don't start that VNC server.
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# (You might be able to figure out a way to do this yourself.)
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#
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# See the next setting for an allowed hosts file. The default for port
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# redirection is off.
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#
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my $enable_port_redirection = 0;
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# A file with allowed port redirections. The empty string '' (the
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# default) means all host:port redirections would be allowed.
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#
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# Format of the file: A list of 'user@host:port' or 'host:port'
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# entries, one per line. Port ranges, e.g. host:n-m are also accepted.
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#
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# Leading and trailing whitespace is trimmed off each line. Blank lines
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# and comment lines starting with '#' are skipped. A line consisting of
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# 'ALL' matches everything. If no match can be found or the file cannot
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# be opened the connection is dropped.
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#
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my $port_redirection_allowed_hosts = '';
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##########################################################################
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# Allowed users:
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#
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# To limit which users can use this service, set the following to a file
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# that contains the allowed user names one per line. Lines starting with
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# the '#' character are skipped.
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#
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my $allowed_users_file = '';
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##########################################################################
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# Denied users:
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#
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# As with $allowed_users_file, but to deny certain users. Applied after
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# any $allowed_users_file check and overrides the result.
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#
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my $denied_users_file = '';
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##########################################################################
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# trustUrlVncCert applet parameter:
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#
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# Set to 0 to have the java applet html set the parameter
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# trustUrlVncCert=no, i.e. the applet will not automatically accept
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# an SSL cert already accepted by an HTTPS URL. See $applet_html and
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# print_applet_html() below for more info.
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#
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my $trustUrlVncCert = 1;
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##########################################################################
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# One-time VNC password fifo:
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#
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# For extra security against local untrusted users a fifo is used
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# to copy the one-time VNC password to the user's VNC password file
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# ~user/x11vnc.pw. If that fifo transfer technique causes problems,
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# you can set this value to 1 to disable the security feature:
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#
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my $disable_vnc_passwd_fifo_safety = 0;
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##########################################################################
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# Comment this out if you don't want PATH modified:
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#
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$ENV{PATH} = "/usr/bin:/bin:$ENV{PATH}";
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##########################################################################
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# For the next two settings, note that most users will be confused that
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# geometry and session are ignored when they are returning to their
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# existing desktop session (x11vnc FINDDISPLAY action.)
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##########################################################################
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# Used below if user did not specify preferred geometry and color depth:
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#
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my $default_geometry = '1024x768x24';
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# Set this to the list of x11vnc -create sessions types to show a session
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# dropdown for the user to select from.
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#
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my $session_types = '';
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#
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# example:
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#$session_types = 'gnome kde xfce lxde wmaker enlightenment mwm twm failsafe';
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##########################################################################
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# Set this to 1 to enable user setting a unique tag for each one
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# of his desktops and so can have multiple ones simultaneously and
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# select which one he wants. For now we just hack this onto geometry
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# 1024x768x24:my_2nd_desktop but ultimately there should be a form entry
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# for it. Search for enable_unique_tags for more info:
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#
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my $enable_unique_tags = 0;
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my $unique_tag = '';
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##########################################################################
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# String of HTML for the login form:
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#
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# Feel free to customize to your taste, _USERNAME_ and _GEOMETRY_ are
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# expanded to that of the request.
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#
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my $login_str = <<"END";
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<title>x11vnc web access</title>
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<h3>x11vnc web access</h3>
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<form action="$ENV{REQUEST_URI}" method="post">
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<table border="0">
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<tr><td colspan=2><h2>Login</h2></td></tr>
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<tr><td>Username:</td><td>
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<input type="text" name="username" maxlength="40" value="_USERNAME_">
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</td></tr>
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<tr><td>Password:</td><td>
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<input type="password" name="password" maxlength="50">
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</td></tr>
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<tr><td>Geometry:</td><td>
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<input type="text" name="geometry" maxlength="40" value="_GEOMETRY_">
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</td></tr>
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<!-- session -->
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<tr><td colspan="2" align="right">
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<input type="submit" name="submit" value="Login">
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</td></tr>
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</table>
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</form>
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END
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##########################################################################
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# String of HTML returned to web browser to launch applet:
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#
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# Feel free to customize to your taste, _UID_, _VNC_PORT_, _WIDTH_,
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# _HEIGHT_, _PASS_, _TRUST_UVC_, _APPLET_JAR_, and _APPLET_CLASS_ are
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# expanded to the appropriate values before sending out to the browser.
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#
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my $applet_html = <<"END";
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<html>
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<TITLE>
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x11vnc desktop (_UID_/_VNC_PORT_)
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</TITLE>
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<APPLET CODE=_APPLET_CLASS_ ARCHIVE=_APPLET_JAR_ WIDTH=_WIDTH_ HEIGHT=_HEIGHT_>
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<param name=PORT value=_VNC_PORT_>
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<param name=VNCSERVERPORT value=_VNC_PORT_>
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<param name=PASSWORD value=_PASS_>
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<param name=trustUrlVncCert value=_TRUST_UVC_>
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<param name="Open New Window" value=yes>
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<param name="Offer Relogin" value=no>
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<param name="ignoreMSLogonCheck" value=yes>
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<param name="delayAuthPanel" value=yes>
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<!-- extra -->
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</APPLET>
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<br>
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<a href="$ENV{REQUEST_URI}">Login page</a><br>
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<a href=http://www.karlrunge.com/x11vnc>x11vnc website</a>
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</html>
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END
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##########################################################################
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# These java applet strings are expanded into the above $applet_html.
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# Note that $applet_jar is relative to your apache DocumentRoot (htdocs)
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# not the filesystem root.
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#
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my $applet_jar = '/UltraViewerSSL.jar';
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my $applet_class = 'VncViewer.class';
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# These make the applet panel smaller because we use 'Open New Window'
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# anyway (set to 'W' or 'H' to use actual session geometry values):
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#
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my $applet_width = '400';
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my $applet_height = '300';
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# To customize ALL of the HTML printed out you may need to redefine
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|
# the bye() subtroutine in your desktop.cgi.conf file.
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##########################################################################
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|
# Override any of the above settings by setting them in a file named
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|
# 'desktop.cgi.conf'. It is sourced here.
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#
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|
# You can override any variable set above by supplying perl code
|
|
# in $0.conf that sets it to the desired value.
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#
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# Some examples you could put in $0.conf:
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#
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# $x11vnc = '/usr/local/bin/x11vnc';
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# $x11vnc_extra_opts = '-env FD_PROG=/usr/bin/xclock';
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# $x11vnc_extra_opts = '-ssl /usr/local/etc/dtcgi.pem';
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# $find_free_port = 'fixed:5999';
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# $enable_port_redirection = 1;
|
|
# $allowed_users_file = '/usr/local/etc/dtcgi.allowed';
|
|
#
|
|
if (-f "$0.conf") {
|
|
eval `cat "$0.conf"`;
|
|
}
|
|
|
|
|
|
##########################################################################
|
|
# END OF MAIN USER SETTINGS.
|
|
# Only power users should change anything below.
|
|
##########################################################################
|
|
|
|
# Print http header reply:
|
|
#
|
|
print STDOUT "Content-Type: text/html\r\n\r\n";
|
|
|
|
|
|
# Require HTTPS so that unix and vnc passwords are not sent in clear text
|
|
# (perhaps it is too late...) Disable HTTPS here at your own risk.
|
|
#
|
|
if ($ENV{HTTPS} !~ /^on$/i) {
|
|
bye("HTTPS must be used (to encrypt passwords)");
|
|
}
|
|
|
|
|
|
# Read URL request:
|
|
#
|
|
my $request;
|
|
if ($ENV{'REQUEST_METHOD'} eq "POST") {
|
|
read(STDIN, $request, $ENV{'CONTENT_LENGTH'});
|
|
} elsif ($ENV{'REQUEST_METHOD'} eq "GET" ) {
|
|
$request = $ENV{'QUERY_STRING'};
|
|
} else {
|
|
$request = $ARGV[0];
|
|
}
|
|
|
|
my %request = url_decode(split(/[&=]/, $request));
|
|
|
|
|
|
# Experiment for FD_TAG x11vnc feature for multiple desktops for a
|
|
# single user:
|
|
#
|
|
# we hide it in geometry:tag for now:
|
|
#
|
|
if ($enable_unique_tags && $request{geometry} =~ /^(.*):(\w+)$/) {
|
|
$request{geometry} = $1;
|
|
$unique_tag = $2;
|
|
}
|
|
|
|
# Check/set geometry and session:
|
|
#
|
|
if (!exists $request{geometry} || $request{geometry} !~ /^[x\d]+$/) {
|
|
# default geometry and depth:
|
|
$request{geometry} = $default_geometry;
|
|
}
|
|
if (!exists $request{session} || $request{session} =~ /^\s*$/) {
|
|
$request{session} = '';
|
|
}
|
|
|
|
|
|
# Expand _USERNAME_ and _GEOMETRY_ in the login string HTML:
|
|
#
|
|
$login_str =~ s/_USERNAME_/$request{username}/g;
|
|
$login_str =~ s/_GEOMETRY_/$request{geometry}/g;
|
|
|
|
|
|
# Check x11vnc version for installers of this script who do not know
|
|
# how to read and follow instructions:
|
|
#
|
|
my $version = (split(' ', `$x11vnc -version`))[1];
|
|
$version =~ s/\D*$//;
|
|
|
|
my ($major, $minor, $micro) = split(/\./, $version);
|
|
if ($major !~ /^\d+$/ || $minor !~ /^\d+$/) {
|
|
bye("The x11vnc program is not installed correctly.");
|
|
}
|
|
$micro = 0 unless $micro;
|
|
my $level = $major * 100 * 100 + $minor * 100 + $micro;
|
|
my $needed = 0 * 100 * 100 + 9 * 100 + 10;
|
|
if ($level < $needed) {
|
|
bye("x11vnc version 0.9.10 or later is required. (Found version $version)");
|
|
}
|
|
|
|
|
|
# Set up user selected desktop session list, if enabled:
|
|
#
|
|
my %sessions;
|
|
|
|
if ($session_types ne '') {
|
|
my $str = "<tr><td>Session:</td><td>\n<select name=session>";
|
|
$str .= "<option value=none>select</option>";
|
|
|
|
foreach my $sess (split(' ', $session_types)) {
|
|
next if $sess =~ /^\s*$/;
|
|
next if $sess !~ /^\w+$/; # alphanumeric
|
|
$sessions{$sess} = 1;
|
|
$str .= "<option value=$sess>$sess</option>";
|
|
}
|
|
$str .= "</select>\n</td></tr>";
|
|
|
|
# This forces $request{session} to be a valid one:
|
|
#
|
|
if (! exists $sessions{$request{session}}) {
|
|
$request{session} = 'none';
|
|
}
|
|
|
|
# Insert into login_str:
|
|
#
|
|
my $r = $request{session};
|
|
$str =~ s/option value=\Q$r\E/option selected value=$r/;
|
|
$login_str =~ s/<!-- session -->/$str/;
|
|
}
|
|
|
|
|
|
# If no username or password, show login form:
|
|
#
|
|
if (!$request{username} && !$request{password}) {
|
|
bye($login_str);
|
|
} elsif (!$request{username}) {
|
|
bye("No Username.<p>$login_str");
|
|
} elsif (!$request{password}) {
|
|
bye("No Password.<p>$login_str");
|
|
}
|
|
|
|
|
|
# Some shorthand names:
|
|
#
|
|
my $username = $request{username};
|
|
my $password = $request{password};
|
|
my $geometry = $request{geometry};
|
|
my $session = $request{session};
|
|
|
|
|
|
# If port redirection is enabled, split username@host:port
|
|
#
|
|
my $redirect_host = '';
|
|
my $current_fh1 = '';
|
|
my $current_fh2 = '';
|
|
|
|
if ($enable_port_redirection) {
|
|
($username, $redirect_host) = split(/@/, $username, 2);
|
|
if ($redirect_host ne '') {
|
|
# will exit if the redirection is not allowed:
|
|
check_redirect_host();
|
|
}
|
|
}
|
|
|
|
# If there is an $allowed_users_file, check username against it:
|
|
#
|
|
if ($allowed_users_file ne '') {
|
|
if (! open(USERS, "<$allowed_users_file")) {
|
|
bye("Internal Error #0");
|
|
}
|
|
my $ok = 0;
|
|
while (<USERS>) {
|
|
chomp;
|
|
$_ =~ s/^\s*//;
|
|
$_ =~ s/\s*$//;
|
|
next if /^#/;
|
|
if ($username eq $_) {
|
|
$ok = 1;
|
|
}
|
|
}
|
|
close USERS;
|
|
if (! $ok) {
|
|
bye("Denied Username.<p>$login_str");
|
|
}
|
|
}
|
|
|
|
# If there is a $denied_users_file, check username against it:
|
|
#
|
|
if ($denied_users_file ne '') {
|
|
if (! open(USERS, "<$denied_users_file")) {
|
|
bye("Internal Error #0");
|
|
}
|
|
my $ok = 1;
|
|
while (<USERS>) {
|
|
chomp;
|
|
$_ =~ s/^\s*//;
|
|
$_ =~ s/\s*$//;
|
|
next if /^#/;
|
|
if ($username eq $_) {
|
|
$ok = 0;
|
|
}
|
|
}
|
|
close USERS;
|
|
if (! $ok) {
|
|
bye("Denied Username.<p>$login_str");
|
|
}
|
|
}
|
|
|
|
# Require username to be alphanumeric + '-' + '_':
|
|
# (one may want to add '.' as well)
|
|
#
|
|
if ($username !~ /^\w[-\w]*$/) {
|
|
bye("Invalid Username.<p>$login_str");
|
|
}
|
|
|
|
|
|
# Get the userid number, we may use it as his VNC display port; this
|
|
# also checks if the username exists:
|
|
#
|
|
my $uid = `/usr/bin/id -u '$username'`;
|
|
chomp $uid;
|
|
if ($? != 0 || $uid !~ /^\d+$/) {
|
|
bye("Invalid Username.<p>$login_str");
|
|
}
|
|
|
|
|
|
# Use x11vnc trick to check if the unix password is valid:
|
|
# (requires x11vnc 0.9.10 or later.)
|
|
#
|
|
if (!open(X11VNC, "| $x11vnc -unixpw \%stdin > /dev/null")) {
|
|
bye("Internal Error #1");
|
|
}
|
|
print X11VNC "$username:$password\n";
|
|
|
|
if (!close X11VNC) {
|
|
# x11vnc returns non-zero for invalid username+password:
|
|
bye("Invalid Password.<p>$login_str");
|
|
}
|
|
|
|
|
|
# Initialize random number generator for use below:
|
|
#
|
|
initialize_random();
|
|
|
|
|
|
# Set vnc port:
|
|
#
|
|
my $vnc_port = 0;
|
|
my $fixed_port = 0;
|
|
|
|
if (! $find_free_port) {
|
|
# Fixed port based on userid (we assume it is free):
|
|
#
|
|
$vnc_port = $starting_port + $uid;
|
|
|
|
} elsif ($find_free_port =~ /^fixed:(\d+)$/) {
|
|
#
|
|
# Enable the -loopbg method that tries to share a single port:
|
|
#
|
|
$vnc_port = $1;
|
|
$fixed_port = 1;
|
|
} else {
|
|
# Autoselect a port, either default range (7000-8000) or a user
|
|
# supplied range. (note that $find_free_port will now contain
|
|
# a socket listening on the found port so that it is held.)
|
|
#
|
|
$vnc_port = auto_select_port();
|
|
}
|
|
|
|
# Check for crazy port value:
|
|
#
|
|
if ($vnc_port > 64000 || $vnc_port < 1) {
|
|
bye("Internal Error #2 $vnc_port");
|
|
}
|
|
|
|
|
|
# If port redirection is enabled and the user selected it via
|
|
# username@host:port, we do that right now and then exit.
|
|
#
|
|
if ($enable_port_redirection && $redirect_host ne '') {
|
|
port_redir();
|
|
exit 0;
|
|
}
|
|
|
|
|
|
# Make a random, onetime vnc password:
|
|
#
|
|
my $pass = '';
|
|
my $chars = '0123456789abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ';
|
|
my @abc = split(//, $chars);
|
|
|
|
for (my $i = 0; $i < 8; $i++) {
|
|
$pass .= $abc[ rand(scalar(@abc)) ];
|
|
}
|
|
|
|
# Use x11vnc trick to switch to user and store vnc pass in the passwdfile.
|
|
# Result is $pass is placed in user's $HOME/x11vnc.pw
|
|
#
|
|
# (This is actually difficult to do without untrusted LOCAL users being
|
|
# able to see the pass as well, see copy_password_to_user() for details
|
|
# on how we try to avoid this.)
|
|
#
|
|
copy_password_to_user($pass);
|
|
|
|
|
|
# Make a tmp file for x11vnc launcher script:
|
|
#
|
|
my $tmpfile = `/bin/mktemp /tmp/desktop.cgi.XXXXXX`;
|
|
chomp $tmpfile;
|
|
|
|
# Check if the tmpfile is valid:
|
|
#
|
|
if (! -e $tmpfile || ! -o $tmpfile || -l $tmpfile) {
|
|
unlink $tmpfile;
|
|
bye("Internal Error #3");
|
|
}
|
|
if (!chmod 0644, $tmpfile) {
|
|
unlink $tmpfile;
|
|
bye("Internal Error #4");
|
|
}
|
|
if (!open(TMP, ">$tmpfile")) {
|
|
unlink $tmpfile;
|
|
bye("Internal Error #5");
|
|
}
|
|
|
|
|
|
# The x11vnc command. You adjust it to suit your needs.
|
|
#
|
|
# some ideas: -env FD_PROG=/usr/bin/gnome-session
|
|
# -env FD_SESS=kde
|
|
# -env FD_TAG=my_2nd_desktop
|
|
# -ultrafilexfer
|
|
#
|
|
# Note that -timeout will cause it to exit if client does not connect
|
|
# and -sslonly disables VeNCrypt SSL connections.
|
|
|
|
# Some settings:
|
|
# (change these if you encounter timing problems, etc.)
|
|
#
|
|
my $timeout = 75;
|
|
my $extra = '';
|
|
if ($fixed_port) {
|
|
# settings for fixed port case:
|
|
$timeout = 45;
|
|
$extra .= " -loopbg100,1";
|
|
}
|
|
$timeout = $x11vnc_timeout if $x11vnc_timeout ne '';
|
|
|
|
if ($session_types ne '') {
|
|
# settings for session selection case:
|
|
if (exists $sessions{$session}) {
|
|
$extra .= " -env FD_SESS='$session'";
|
|
}
|
|
}
|
|
if ($enable_unique_tags && $unique_tag ne '' && $unique_tag =~ /^\w+$/) {
|
|
$extra .= " -env FD_TAG='$unique_tag'";
|
|
}
|
|
|
|
# This md5sum check of the vnc passwd is for extra safety (see
|
|
# copy_password_to_user for details.)
|
|
#
|
|
my $md5sum = '';
|
|
system("type md5sum > /dev/null");
|
|
if ($? == 0) {
|
|
my $md5 = `/bin/mktemp /tmp/desktop.cgi.XXXXXX`;
|
|
chomp $md5;
|
|
# compute md5sum of password:
|
|
if (-o $md5 && open(MD5, "| md5sum > $md5")) {
|
|
print MD5 "$pass\n";
|
|
close MD5;
|
|
if (open(MD5, "<$md5")) {
|
|
# read it:
|
|
my $line = <MD5>;
|
|
close MD5;
|
|
my ($s, $t) = split(' ', $line);
|
|
if (length($s) >= 32 && $s =~ /^\w+$/) {
|
|
# shell code for user to check he has correct passwd:
|
|
$md5sum = "if md5sum \$HOME/x11vnc.pw | grep '$s' > /dev/null; then true; else exit 1; fi";
|
|
}
|
|
}
|
|
}
|
|
unlink $md5;
|
|
}
|
|
|
|
# Write x11vnc command to the tmp file:
|
|
#
|
|
print TMP <<"END";
|
|
#!/bin/sh
|
|
export PATH=/usr/bin:/bin:\$PATH
|
|
$md5sum
|
|
$x11vnc -sigpipe ignore:HUP -nopw -rfbport $vnc_port \\
|
|
-passwdfile \$HOME/x11vnc.pw -oa \$HOME/x11vnc.log \\
|
|
-create -ssl SAVE -sslonly -env FD_GEOM=$geometry \\
|
|
-timeout $timeout $extra $x11vnc_extra_opts \\
|
|
>/dev/null 2>/dev/null </dev/null &
|
|
sleep 2
|
|
exit 0
|
|
END
|
|
|
|
close TMP;
|
|
|
|
# Now launch x11vnc to switch to user and run the wrapper script:
|
|
# (this requires x11vnc 0.9.10 or later.)
|
|
#
|
|
$ENV{UNIXPW_CMD} = "/bin/sh $tmpfile";
|
|
|
|
# For the fixed port scheme we try to cooperate via lock file:
|
|
# (disabled by default.)
|
|
#
|
|
my $rmlock = '';
|
|
#
|
|
if ($fixed_port) {
|
|
# try to grab the fixed port for the next 90 secs removing stale
|
|
# locks older than 60 secs:
|
|
#
|
|
$rmlock = lock_fixed_port(90, 60);
|
|
}
|
|
|
|
# Start the x11vnc cmd:
|
|
#
|
|
if (!open(X11VNC, "| $x11vnc -unixpw \%stdin > /dev/null")) {
|
|
unlink $tmpfile;
|
|
unlink $rmlock if $rmlock;
|
|
bye("Internal Error #6");
|
|
}
|
|
|
|
select(X11VNC); $| = 1; select(STDOUT);
|
|
|
|
# Close any port we held. There is still a gap of time between now
|
|
# and when when x11vnc in $tmpfile reopens the port after the password
|
|
# authentication. So another instance of this script could accidentally
|
|
# think it is free...
|
|
#
|
|
sleep 1;
|
|
close $find_free_port if $find_free_port;
|
|
|
|
print X11VNC "$username:$password\n";
|
|
close X11VNC; # note we ignore return value.
|
|
unlink $tmpfile;
|
|
|
|
if ($rmlock) {
|
|
# let our x11vnc proceed a bit before removing lock.
|
|
sleep 2;
|
|
unlink $rmlock;
|
|
}
|
|
|
|
# Return html for the java applet to connect to x11vnc.
|
|
#
|
|
print_applet_html();
|
|
|
|
exit 0;
|
|
|
|
#################################################################
|
|
# Subroutines:
|
|
|
|
# print the message to client and exit with success.
|
|
#
|
|
sub bye {
|
|
my $msg = shift;
|
|
print STDOUT "<html>$msg</html>\n";
|
|
exit 0;
|
|
}
|
|
|
|
# decode %xx to character:
|
|
#
|
|
sub url_decode {
|
|
foreach (@_) {
|
|
tr/+/ /;
|
|
s/%(..)/pack("c",hex($1))/ge;
|
|
}
|
|
@_;
|
|
}
|
|
|
|
# seed random
|
|
#
|
|
sub initialize_random {
|
|
my $rbytes = '';
|
|
if (open(RAN, "</dev/urandom")) {
|
|
read(RAN, $rbytes, 8);
|
|
} elsif (open(RAN, "</dev/random")) {
|
|
read(RAN, $rbytes, 8);
|
|
} else {
|
|
$rbytes = sprintf("%08d", $$);
|
|
}
|
|
close RAN;
|
|
|
|
# set seed:
|
|
#
|
|
my $seed = join('', unpack("C8", $rbytes));
|
|
$seed = substr($seed, -9);
|
|
srand($seed);
|
|
|
|
for (my $i = 0; $i < ($$ % 4096); $i++) {
|
|
# Mix it up even a little bit more. There should be
|
|
# over 1 billion possible vnc passwords now.
|
|
rand();
|
|
}
|
|
}
|
|
|
|
# Autoselect a port for vnc. Note that a socket for the found port
|
|
# is kept open (and stored in $find_free_port) until we call x11vnc at
|
|
# the end.
|
|
#
|
|
sub auto_select_port {
|
|
my $pmin = $starting_port; # default range 7000-8000.
|
|
my $pmax = $starting_port + 1000;
|
|
|
|
if ($find_free_port =~ /^(\d+)-(\d+)$/) {
|
|
# user supplied a range:
|
|
$pmin = $1;
|
|
$pmax = $2;
|
|
if ($pmin > $pmax) {
|
|
($pmin, $pmax) = ($pmax, $pmin);
|
|
}
|
|
} elsif ($find_free_port > 1024) {
|
|
# user supplied a starting port:
|
|
$pmin = $find_free_port;
|
|
$pmax = $pmin + 1000;
|
|
}
|
|
|
|
# Try to add a bit of randomness to the starting port so
|
|
# simultaneous instances of this script won't be fooled by the gap
|
|
# of time before x11vnc reopens the port (see near the bottom.)
|
|
#
|
|
my $dp = int(rand(1.0) * 0.25 * ($pmax - $pmin));
|
|
if ($pmin + $dp < $pmax - 20) {
|
|
$pmin = $pmin + $dp;
|
|
}
|
|
|
|
my $port = 0;
|
|
|
|
# Now try to find a free one:
|
|
#
|
|
for (my $p = $pmin; $p <= $pmax; $p++) {
|
|
my $sock = '';
|
|
if ($have_inet6 && $listen_on_ipv6) {
|
|
eval {$sock = IO::Socket::INET6->new(
|
|
Listen => 1,
|
|
LocalPort => $p,
|
|
ReuseAddr => 1,
|
|
Domain => AF_INET6,
|
|
LocalAddr => "::",
|
|
Proto => "tcp"
|
|
);};
|
|
} else {
|
|
$sock = IO::Socket::INET->new(
|
|
Listen => 1,
|
|
LocalPort => $p,
|
|
ReuseAddr => 1,
|
|
Proto => "tcp"
|
|
);
|
|
}
|
|
if ($sock) {
|
|
# we will keep this open until we call x11vnc:
|
|
$find_free_port = $sock;
|
|
$port = $p;
|
|
last;
|
|
}
|
|
}
|
|
return $port;
|
|
}
|
|
|
|
# Since apache typically runs as user 'apache', 'nobody', etc, and not
|
|
# as root it is tricky for us to copy the pass string to a file owned by
|
|
# the user without some other untrusted local user being able to learn
|
|
# the password (e.g. via reading a file or watching ps.) Note that with
|
|
# the x11vnc -unixpw trick we unfortunately can't use a pipe because
|
|
# the user command is run in its own tty.
|
|
#
|
|
# The best way would be a sudo action or a special setuid program for
|
|
# copying. So consider doing that and thereby simplify this function.
|
|
#
|
|
# Short of a special program doing this, we use a fifo so ONLY ONE
|
|
# process can read the password. If the untrusted local user reads it,
|
|
# then the logging-in user's x11vnc won't get it. The login and x11vnc
|
|
# will fail, but the untrusted user won't gain access to the logging-in
|
|
# user's desktop.
|
|
#
|
|
# So here we start long, tedious work carefully managing the fifo.
|
|
#
|
|
sub copy_password_to_user {
|
|
|
|
my $pass = shift;
|
|
|
|
my $use_fifo = '';
|
|
|
|
# Find a command to make a fifo:
|
|
#
|
|
system("type mkfifo > /dev/null");
|
|
if ($? == 0) {
|
|
$use_fifo = 'mkfifo %s';
|
|
} else {
|
|
system("type mknod > /dev/null");
|
|
if ($? == 0) {
|
|
$use_fifo = 'mknod %s p';
|
|
}
|
|
}
|
|
|
|
# Create the filename for our fifo:
|
|
#
|
|
my $fifo = `/bin/mktemp /tmp/desktop.cgi.XXXXXX`;
|
|
chomp $fifo;
|
|
|
|
if (! -e $fifo || ! -o $fifo || -l $fifo) {
|
|
unlink $fifo;
|
|
bye("Internal Error #7");
|
|
}
|
|
|
|
# disable fifo safety if requested:
|
|
#
|
|
if ($disable_vnc_passwd_fifo_safety) {
|
|
$use_fifo = '';
|
|
}
|
|
|
|
# Make the fifo:
|
|
#
|
|
if ($use_fifo) {
|
|
$use_fifo = sprintf($use_fifo, $fifo);
|
|
|
|
# there is a small race here:
|
|
system("umask 077; rm -f $fifo; $use_fifo; chmod 600 $fifo");
|
|
|
|
if (!chmod 0600, $fifo) {
|
|
# we chmod once more..
|
|
unlink $fifo;
|
|
bye("Internal Error #8");
|
|
}
|
|
|
|
if (! -o $fifo || ! -p $fifo || -l $fifo) {
|
|
# but we get out if not owned by us anymore:
|
|
unlink $fifo;
|
|
bye("Internal Error #9");
|
|
}
|
|
}
|
|
|
|
# Build cmd for user to read our fifo:
|
|
#
|
|
my $upw = '$HOME/x11vnc.pw';
|
|
$ENV{UNIXPW_CMD} = "touch $upw; chmod 600 $upw; cat $fifo > $upw";
|
|
|
|
# Start it:
|
|
#
|
|
if (!open(X11VNC, "| $x11vnc -unixpw \%stdin > /dev/null")) {
|
|
unlink $fifo;
|
|
bye("Internal Error #10");
|
|
}
|
|
select(X11VNC); $| = 1; select(STDOUT);
|
|
|
|
if (! $use_fifo) {
|
|
# regular file, we need to write it now.
|
|
if (!open(FIFO, ">$fifo")) {
|
|
close X11VNC;
|
|
unlink $fifo;
|
|
bye("Internal Error #11");
|
|
}
|
|
print FIFO "$pass\n";
|
|
close FIFO;
|
|
}
|
|
|
|
# open fifo up for reading.
|
|
# (this means the bad guy can read it too.)
|
|
#
|
|
if (!chmod 0644, $fifo) {
|
|
unlink $fifo;
|
|
bye("Internal Error #12");
|
|
}
|
|
|
|
# send the user's passwd now:
|
|
#
|
|
print X11VNC "$username:$password\n";
|
|
|
|
if ($use_fifo) {
|
|
# wait a bit for the cat $fifo to start, reader will block.
|
|
sleep 1;
|
|
if (!open(FIFO, ">$fifo")) {
|
|
close X11VNC;
|
|
unlink $fifo;
|
|
bye("Internal Error #13");
|
|
}
|
|
# here it goes:
|
|
print FIFO "$pass\n";
|
|
close FIFO;
|
|
}
|
|
close X11VNC; # note we ignore return value.
|
|
fsleep(0.5);
|
|
unlink $fifo;
|
|
|
|
# Done!
|
|
}
|
|
|
|
# For fixed, single port mode. Try to open and lock the port before
|
|
# proceeding.
|
|
#
|
|
sub lock_fixed_port {
|
|
my ($t_max, $t_age) = @_;
|
|
|
|
# lock file name:
|
|
#
|
|
my $lock = '/tmp/desktop.cgi.lock';
|
|
my $remove = '';
|
|
|
|
my $t = 0;
|
|
my $sock = '';
|
|
|
|
while ($t < $t_max) {
|
|
if (-e $lock) {
|
|
# clean out stale locks if possible:
|
|
if (! -l $lock) {
|
|
unlink $lock;
|
|
} else {
|
|
my ($pid, $time) = split(/:/, readlink($lock));
|
|
if (! -d "/proc/$pid") {
|
|
unlink $lock;
|
|
}
|
|
if (time() > $time + $t_age) {
|
|
unlink $lock;
|
|
}
|
|
}
|
|
}
|
|
|
|
my $reason = '';
|
|
|
|
if (-l $lock) {
|
|
# someone has locked it.
|
|
$reason = 'locked';
|
|
} else {
|
|
# unlocked, try to listen on port:
|
|
if ($have_inet6 && $listen_on_ipv6) {
|
|
eval {$sock = IO::Socket::INET6->new(
|
|
Listen => 1,
|
|
LocalPort => $vnc_port,
|
|
ReuseAddr => 1,
|
|
Domain => AF_INET6,
|
|
LocalAddr => "::",
|
|
Proto => "tcp"
|
|
);};
|
|
} else {
|
|
$sock = IO::Socket::INET->new(
|
|
Listen => 1,
|
|
LocalPort => $vnc_port,
|
|
ReuseAddr => 1,
|
|
Proto => "tcp"
|
|
);
|
|
}
|
|
if ($sock) {
|
|
# we got it, now try to lock:
|
|
my $str = "$$:" . time();
|
|
if (symlink($str, $lock)) {
|
|
$remove = $lock;
|
|
$find_free_port = $sock;
|
|
last;
|
|
}
|
|
# wow, we didn't lock it...
|
|
$reason = "symlink failed: $!";
|
|
close $sock;
|
|
} else {
|
|
$reason = "listen failed: $!";
|
|
}
|
|
}
|
|
# sleep a bit and then try again:
|
|
#
|
|
print STDERR "$$ failed to get fixed port $vnc_port for $username at $t ($reason)\n";
|
|
$sock = '';
|
|
$t += 5;
|
|
sleep 5;
|
|
}
|
|
if (! $sock) {
|
|
bye("Failed to lock fixed TCP port. Try again a bit later.<p>$login_str");
|
|
}
|
|
print STDERR "$$ got fixed port $vnc_port for $username at $t\n";
|
|
|
|
# Return the file to remove, if any:
|
|
#
|
|
return $remove;
|
|
}
|
|
|
|
|
|
# Return html for the java applet to connect to x11vnc.
|
|
#
|
|
# N.B. Please examine the applet params, e.g. trustUrlVncCert=yes to
|
|
# see if you agree with them. See x11vnc classes/ssl/README for all
|
|
# parameters.
|
|
#
|
|
# Note how we do not take extreme care to authenticate the server to
|
|
# the client applet (but note that trustUrlVncCert=yes is better than
|
|
# trustAllVncCerts=yes) One can tighten all of this up at the expense
|
|
# of extra certificate dialogs (assuming the user bothers to check...)
|
|
#
|
|
# This assumes /UltraViewerSSL.jar is at document root; you need to put
|
|
# it there.
|
|
#
|
|
sub print_applet_html {
|
|
my ($W, $H, $D) = split(/x/, $geometry);
|
|
|
|
# make it smaller since we 'Open New Window' below anyway.
|
|
if ($applet_width ne 'W') {
|
|
$W = $applet_width;
|
|
}
|
|
if ($applet_height ne 'H') {
|
|
$H = $applet_height;
|
|
}
|
|
|
|
my $tUVC = ($trustUrlVncCert ? 'yes' : 'no');
|
|
|
|
# see $applet_html set in defaults section for more info:
|
|
#
|
|
my $str = $applet_html;
|
|
|
|
$str =~ s/_UID_/$uid/g;
|
|
$str =~ s/_VNC_PORT_/$vnc_port/g;
|
|
$str =~ s/_WIDTH_/$W/g;
|
|
$str =~ s/_HEIGHT_/$H/g;
|
|
$str =~ s/_PASS_/$pass/g;
|
|
$str =~ s/_APPLET_JAR_/$applet_jar/g;
|
|
$str =~ s/_APPLET_CLASS_/$applet_class/g;
|
|
$str =~ s/_TRUST_UVC_/$tUVC/g;
|
|
|
|
if ($enable_port_redirection && $redirect_host ne '') {
|
|
$str =~ s/name=PASSWORD value=.*>/name=NOT_USED value=yes>/i;
|
|
#$str =~ s/<!-- extra -->/<!-- extra -->\n<param name="ignoreProxy" value=yes>/;
|
|
}
|
|
|
|
print $str;
|
|
}
|
|
|
|
##########################################################################
|
|
# The following subroutines are for port redirection only, which is
|
|
# disabled by default ($enable_port_redirection == 0)
|
|
#
|
|
sub port_redir {
|
|
# To aid in avoiding zombies:
|
|
#
|
|
setpgrp(0, 0);
|
|
|
|
# For the fixed port scheme we try to cooperate via lock file:
|
|
#
|
|
my $rmlock = '';
|
|
#
|
|
if ($fixed_port) {
|
|
# try to grab the fixed port for the next 90 secs removing
|
|
# stale locks older than 60 secs:
|
|
#
|
|
$rmlock = lock_fixed_port(90, 60);
|
|
|
|
} elsif ($find_free_port eq '0') {
|
|
if ($have_inet6 && $listen_on_ipv6) {
|
|
eval {$find_free_port = IO::Socket::INET6->new(
|
|
Listen => 1,
|
|
LocalPort => $vnc_port,
|
|
ReuseAddr => 1,
|
|
Domain => AF_INET6,
|
|
LocalAddr => "::",
|
|
Proto => "tcp"
|
|
);};
|
|
} else {
|
|
$find_free_port = IO::Socket::INET->new(
|
|
Listen => 1,
|
|
LocalPort => $vnc_port,
|
|
ReuseAddr => 1,
|
|
Proto => "tcp"
|
|
);
|
|
}
|
|
}
|
|
# In all cases, at this point $find_free_port is the listening
|
|
# socket.
|
|
|
|
# fork a helper process to do the port redir:
|
|
#
|
|
# Actually we need to spawn 4(!) of them in case the proxy check
|
|
# /check.https.proxy.connection (it is by default) and the other
|
|
# test connections. Spawn one for each expected connection, for
|
|
# whatever applet parameter usage mode you set up.
|
|
#
|
|
for (my $n = 1; $n <= 4; $n++) {
|
|
my $pid = fork();
|
|
if (! defined $pid) {
|
|
bye("Internal Error #14");
|
|
} elsif ($pid) {
|
|
wait;
|
|
} else {
|
|
if (fork) {
|
|
exit 0;
|
|
}
|
|
setpgrp(0, 0);
|
|
handle_conn();
|
|
exit 0;
|
|
}
|
|
}
|
|
|
|
# We now close the listening socket:
|
|
#
|
|
close $find_free_port;
|
|
|
|
if ($rmlock) {
|
|
# let our process proceed a bit before removing lock.
|
|
sleep 1;
|
|
unlink $rmlock;
|
|
}
|
|
|
|
# Now send html to the browser so it can connect:
|
|
#
|
|
print_applet_html();
|
|
|
|
exit 0;
|
|
}
|
|
|
|
# This checks the validity of a username@host:port for the port
|
|
# redirection mode. Finishes and exits if it is invalid.
|
|
#
|
|
sub check_redirect_host {
|
|
# First check that the host:port string is valid:
|
|
#
|
|
if ($redirect_host !~ /^\w[-\w\.]*:\d+$/) {
|
|
bye("Invalid Redirect Host:Port.<p>$login_str");
|
|
}
|
|
# Second, check if the allowed host file permits it:
|
|
#
|
|
if ($port_redirection_allowed_hosts ne '') {
|
|
if (! open(ALLOWED, "<$port_redirection_allowed_hosts")) {
|
|
bye("Internal Error #15");
|
|
}
|
|
my $ok = 0;
|
|
while (my $line = <ALLOWED>) {
|
|
chomp $line;
|
|
# skip blank lines and '#' comments:
|
|
next if $line =~ /^\s*$/;
|
|
next if $line =~ /^\s*#/;
|
|
|
|
# trim spaces from ends:
|
|
$line =~ s/^\s*//;
|
|
$line =~ s/\s*$//;
|
|
|
|
# collect host:ports in case port range given:
|
|
my @items;
|
|
if ($line =~ /^(.*):(\d+)-(\d+)$/) {
|
|
# port range:
|
|
my $host = $1;
|
|
my $pmin = $2;
|
|
my $pmax = $3;
|
|
for (my $p = $pmin; $p <= $pmax; $p++) {
|
|
push @items, "$host:$p";
|
|
}
|
|
} else {
|
|
push @items, $line;
|
|
}
|
|
|
|
# now check each item for a match:
|
|
foreach my $item (@items) {
|
|
if ($item eq 'ALL') {
|
|
$ok = 1;
|
|
last;
|
|
} elsif ($item =~ /@/) {
|
|
if ("$username\@$redirect_host" eq $item) {
|
|
$ok = 1;
|
|
last;
|
|
}
|
|
} elsif ($redirect_host eq $item) {
|
|
$ok = 1;
|
|
last;
|
|
}
|
|
}
|
|
# got a match:
|
|
last if $ok;
|
|
}
|
|
close ALLOWED;
|
|
|
|
if (! $ok) {
|
|
bye("Disallowed Redirect Host:Port.<p>$login_str");
|
|
}
|
|
}
|
|
}
|
|
|
|
# Much of this code is borrowed from 'connect_switch':
|
|
#
|
|
# (it only applies to the vnc redirector $enable_port_redirection mode
|
|
# which is off by default.)
|
|
#
|
|
sub handle_conn {
|
|
close STDIN;
|
|
close STDOUT;
|
|
close STDERR;
|
|
|
|
$SIG{ALRM} = sub {close $find_free_port; exit 0};
|
|
|
|
# We only wait 30 secs for the redir case, esp. since
|
|
# we need to spawn so many helpers...
|
|
#
|
|
alarm(30);
|
|
|
|
my ($client, $ip) = $find_free_port->accept();
|
|
|
|
alarm(0);
|
|
|
|
close $find_free_port;
|
|
|
|
if (!$client) {
|
|
exit 1;
|
|
}
|
|
|
|
my $host = '';
|
|
my $port = '';
|
|
if ($redirect_host =~ /^(.*):(\d+)$/) {
|
|
($host, $port) = ($1, $2);
|
|
}
|
|
|
|
my $sock = IO::Socket::INET->new(
|
|
PeerAddr => $host,
|
|
PeerPort => $port,
|
|
Proto => "tcp"
|
|
);
|
|
if (! $sock && $have_inet6) {
|
|
eval {$sock = IO::Socket::INET6->new(
|
|
PeerAddr => $host,
|
|
PeerPort => $port,
|
|
Proto => "tcp"
|
|
);};
|
|
}
|
|
|
|
if (! $sock) {
|
|
close $client;
|
|
exit 1;
|
|
}
|
|
|
|
$current_fh1 = $client;
|
|
$current_fh2 = $sock;
|
|
|
|
$SIG{TERM} = sub {close $current_fh1; close $current_fh2; exit 0};
|
|
|
|
my $killpid = 1;
|
|
|
|
my $parent = $$;
|
|
if (my $child = fork()) {
|
|
xfer($sock, $client, 'S->C');
|
|
if ($killpid) {
|
|
fsleep(0.5);
|
|
kill 'TERM', $child;
|
|
}
|
|
} else {
|
|
xfer($client, $sock, 'C->S');
|
|
if ($killpid) {
|
|
fsleep(0.75);
|
|
kill 'TERM', $parent;
|
|
}
|
|
}
|
|
exit 0;
|
|
}
|
|
|
|
# This does socket data transfer in one direction.
|
|
#
|
|
sub xfer {
|
|
my($in, $out, $lab) = @_;
|
|
my ($RIN, $WIN, $EIN, $ROUT);
|
|
$RIN = $WIN = $EIN = "";
|
|
$ROUT = "";
|
|
vec($RIN, fileno($in), 1) = 1;
|
|
vec($WIN, fileno($in), 1) = 1;
|
|
$EIN = $RIN | $WIN;
|
|
my $buf;
|
|
|
|
while (1) {
|
|
my $nf = 0;
|
|
while (! $nf) {
|
|
$nf = select($ROUT=$RIN, undef, undef, undef);
|
|
}
|
|
my $len = sysread($in, $buf, 8192);
|
|
if (! defined($len)) {
|
|
next if $! =~ /^Interrupted/;
|
|
last;
|
|
} elsif ($len == 0) {
|
|
last;
|
|
}
|
|
|
|
my $offset = 0;
|
|
my $quit = 0;
|
|
while ($len) {
|
|
my $written = syswrite($out, $buf, $len, $offset);
|
|
if (! defined $written) {
|
|
$quit = 1;
|
|
last;
|
|
}
|
|
$len -= $written;
|
|
$offset += $written;
|
|
}
|
|
last if $quit;
|
|
}
|
|
close($in);
|
|
close($out);
|
|
}
|
|
|
|
# Sleep a small amount of time (float)
|
|
#
|
|
sub fsleep {
|
|
my ($time) = @_;
|
|
select(undef, undef, undef, $time) if $time;
|
|
}
|