X11vnc For Mac

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X11vnc

x11vnc is a VNC server, it allows one to view remotely and interact with real X displays (i.e. a display corresponding to a physical monitor, keyboard, and mouse) with any VNC viewer. While it is not developed any longer by its original author Karl Runge, LibVNC and the GitHub community have taken over the development.

Mac

x11vnc does not create an extra display (or X desktop) for remote control. Instead, it shows in real time the existing X11 display, unlike Xvnc, part of TigerVNC, which is an alternatives VNC server available in the official repositories.

Also note that x11vnc is not shipped with a client viewer. Any VNC viewer should do the job and be compatible with the x11vnc server while not necessarily using all its functionalities. TigerVNC's vncviewer is a recommended client.

  • 1Setting up x11vnc
    • 1.2Starting
      • 1.2.1Setting X authority
  • 3Troubleshooting
  • 4Tips and tricks

Setting up x11vnc

I wanted to vnc into my tinkerboard, and using the default mac vnc client. I tried different packages, like RealVNC but that has license only for RaspberryPi, then I tried tightvnc but it was not working with the default mac client and getting tigervnc up was also not a smooth process, as it was giving Continue reading 'VNC into the tinkerboard with x11vnc'. Name x11vnc - allow VNC connections to real X11 displays version: 0.9.13, lastmod: 2011-08-10 Synopsis x11vnc OPTION.

Installation

Install x11vnc from the official repositories.

Starting

First, start X either by startx or through a display manager. You may need to set up X to run headless too.

Then, run the following command, all available options are explained in x11vnc(1).

Another option is to place the x11vnc command line in a script which is called at login, for example:

Note: The password 'PASSWORD' above is not secured; anyone who can run ps on the machine will see it. Also note that /var/log/x11vnc.log needs to be created manually and its ownership needs to match that of the user who will run it.

Setting X authority

You may set an X authority file for the VNC server. This is accomplished by using the -auth argument followed by the appropriate file, which will depend on how your X server was started. Generally, assigning an X authority file requires running x11vnc as root.

Start X

X11vnc Windows 10

If that fails, you may have to run instead (as root):

Where user is the username of the user who is running the X server.

Running from xinetd

X11vnc can be run using a xinetd service, which only starts X11vnc once a user connects.

Create an xinetd service entry for x11vnc, for example:

After reloading xinetd.service, X11vnc will start once a client connects to port 5900.

Systemd

To run x11vnc when system boots, create the override with systemctl edit x11vnc.service. The content should be like the following

Replace the second ExecStart with the command you run interactively. Run systemctl enable x11vnc.service if you need.

GDM
Note: Newer GDM packages ship with Xwayland as the default display server backend. The following instructions, however, only apply when using Xorg (else .Xauthority is not created, and x11vnc fails to start). You are therefore advised to uncomment #WaylandEnable=false setting in /etc/gdm/custom.conf in order to proceed.

Newer versions of GDM uses /run/user. Example for user 120 (gdm), used for login screen.

or see Troubleshooting section below

Lightdm

Running from the bash:

LXDM
SDDM

SDDM uses an unpredictable UUID for the auth file [1] therefore one needs to:

Embedding this into a systemd .service file will require a trick to evaluate the find command as shown here [2].

SLIM
Warning: This will set up VNC with NO PASSWORD. This means that ANYBODY who has access to the network the computer is on CAN SEE YOUR XSERVER. It is a fairly simple matter to tunnel your VNC connection through SSH to avoid this. Or, simply set a password, as described below.
Note: The password will only encrypt the login process itself. The transmission is still unencrypted[3].

Setting a password

Running:

uses the password found in ~/.vnc/passwd, where the password is obscured with a fixed key in a VNC compatible format, or alternatively in ~/.vnc/passwdfile, where the first line of the file contains the password.If none of these files can be located, it prompts the user for a password which is saved in ~/.vnc/passwd and is used right away.

The VNC viewer should then prompt for a password when connecting.

Running constantly

By default, x11vnc will accept the first VNC session and shutdown when the session disconnects.In order to avoid that, start x11vnc with either the -many or the -forever argument, like this:

It is also possible to use the following command :

this will restart the server once the session is finished

Accessing

Get a VNC client on another computer, and type in the IP address of the computer running x11vnc. Hit connect, and you should be set.

If you are attempting to access a VNC server / computer (running x11vnc) from outside of its network then you will need to ensure that it has port 5900 forwarded.

SSH Tunnel

You need to have SSH installed and configured.

Use the -localhost flag with x11vnc for it to bind to the local interface. Once that is done, you can use SSH to tunnel the port; then, connect to VNC through SSH.

Simple example (from http://www.karlrunge.com/x11vnc/index.html#tunnelling ):

X11vnc For Mac Installer

(You will likely have to provide passwords/passphrases to login from your current location into your remote_host Unix account; we assume you have a login account on remote_host and it is running the SSH server)

And then in another terminal window on your current machine run the command:

Troubleshooting

1. You can check your ip address and make sure port 5900 is forwarded by visiting this[dead link 2020-04-03 ⓘ] website.

The factual accuracy of this article or section is disputed.

Reason:please use the first argument of the template to provide a brief explanation. (Discuss in Talk:X11vnc#)

2. Tested only on GNOME + GDM

If you cannot start the tunnel, and get error like XOpenDisplay(':0') failed,Check if you have a ~/.Xauthority directory.If that does not exist, You can create one easily (Actually a symlink to actual one) by running command given below as normal user NOT ROOT OR USING Sudo as below:

Client

then try above tunneling example and it should work fine.Further if you want this to be automatically done each time Xorg is restarted, create the xprofile file & make is executable as below

Mac

3. GNOME 3 and x11vnc

If you are using GNOME 3 and x11vnc and you get the following errors

X11vnc client for windows

Try running x11vnc like

Please update if this works / not works for any other display manager or desktop environment.

Screensaver problem

If screensaver starts every 1-2 second, start x11vnc with -nodpms key.

IPv6 port different from IPv4 port

The default behavior for the command:

is for the server to listen to TCP port 5908 and TCP6 port 5900.For the server to listen to the same TCP6 port, also use the -rfbportv6 option to force the IPv6 listening port.For example:

Tips and tricks

This article or section needs language, wiki syntax or style improvements. See Help:Style for reference.

Reason: Use Template:ic. (Discuss in Talk:X11vnc#)

Run x11vnc 'system-wide' in (GDM and GNOME Shell)

Note: This instructions will work only if you are using GDM and GNOME shell in Xorg

If you want to run x11vnc in GDM to login and then you want to run x11vnc in a GNOME shell user session for a 'system-wide' x11vnc you can acomplish that with the following steps

First we need to create a systemd service to launch a x11vnc server in GDM

This will start a x11vnc server protected by the password stored at USER_HOME/.vnc/passwd that shows the GDM to any connected VNC client, however as you may notice, if you click in any of the users, as soon as you login all the VNC clients will show a black screen

To fix this we need to create another systemd service that will start another x11vnc server in the GNOME Shell session assoon as you login

Now, you need to keep in mind 3 things

First, as you may notice in the 'ExecStart' part of the systemd service the command that executes can be separated in two tasks, first it stops the x11vnc-gdm.service (killing the gdm x11vnc server) and then it starts the x11vnc server for the user in the GNOME shell session, this was done like this because if you keep running the GDM x11vnc server in the background, the new x11vnc server for the user, is going to use the next available port, and you would need to change your client connection settings to connect either to the GDM x11vnc server or for your user specific x11vnc server, a setup like this is usefull because the GDM x11vnc server stops as soon as you login into your account.

Second, you need to create a service like this for each user that you want to have this functionallity, dont forget to replace the 'YOUR_USER' and 'USER_HOME' with your actual username.

Third, you need to keep in mind that you might need to change the '-display :X' part of the command to match your system setings, you can view your current display executing the following command.

use the output of the command to match the systemd service.

Now, as you might notice, the x11vnc-gnome-shell systemd service is executed as your (probably) unprivigiled user, this presents a problem if we want to stop the x11vnc-gdm.service so we need to allow the user to stop the GDM service, this is acomplished using sudo, but we need to allow the execution of only that specific command without a password, we can do that with the following steps

execute visudo as root

at the end of the file add the following line and save your changes

Now you now simply need to enable both systemd services as root

When you restart your computer both of them will start running and you can connect to your GDM and GNOME Shell using VNC

Change x11vnc password in each boot

A setup like this could be useful is if you need to share your desktop with several people that you dont trust and you dont want to manually change the password every time, a setup like this would generate boot-unique passwords so if you share your password with someone, you only need to reboot your computer (or re-run the systemd service) and the password would change

The new generated password will be stored as PLAIN TEXT in the /home/$USER/.vnc/autovncpass so it can be accesed simply by using

Keep in mind that storing the password as plain text could represent a security threat, USE THIS AT YOUR OWN RISK.


Anyway, if you want to acomplish this, complete the following steps:


First install expect from the official repositories.

Then, create the following script anywhere in your home directory

Now we need to create a systemd unit file that will execute the script at boot time

Finally you just need to start/enable the systemd service using systemctl and the password will change

you can access the current password by using

See also

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