wayvnc - Man Page

A VNC server for wlroots based Wayland compositors.

Synopsis

wayvnc [options] [address [port]]

Options

-C,  --config=<path>

Select a config file.

-g,--gpu

Enable features that require GPU.

-o,  --output=<name>

Select output to capture.

-k,  --keyboard=<layout>[-variant]

Select keyboard layout. The variant can be appended if needed.

-s,  --seat=<name>

Select seat by name.

-S,  --socket=<path>

Set wayvnc control socket path. Default: $XDG_RUNTIME_DIR/wayvncctl or /tmp/wayvncctl-$UID

-r,  --render-cursor

Enable overlay cursor rendering.

-f,  --max-fps=<fps>

Set the rate limit (default 30).

-p,  --show-performance

Show performance counters.

-u,  --unix-socket

Create a UNIX domain socket instead of TCP, treating the address as a path.

-d,  --disable-input

Disable all remote input. This allows using wayvnc without compositor support of virtual mouse / keyboard protocols.

-V,  --version

Show version info.

-v,--verbose

Be more verbose. Same as setting `--log-level=info`.

-w,--websocket

Create a websocket.

-L,--log-level

Set log level. The levels are: error, warning, info, debug, trace and quiet.

-h,  --help

Get help.

Description

This is a VNC server for wlroots based Wayland compositors. It attaches to a running Wayland session, creates virtual input devices and exposes a single display via the RFB protocol. The Wayland session may be a headless one, so it is also possible to run wayvnc without a physical display attached.

Multiple Outputs

If the Wayland session consists of multiple outputs, only one will be captured. By default this will be the first one, but can be specified by the -o command line argument. The argument accepts the short name such as eDP-1 or DP-4. Running wayvnc in verbose mode (-v) will display the names of all outputs on startup, or you can query them at runtime via the wayvncctl output-list command.

You can also change which output is being captured on the fly via the wayvncctl output-set command.

Configuration

wayvnc searches for a config file in the location

~/$XDG_CONFIG_HOME/wayvnc/config

or if $XDG_CONFIG_HOME is not set

~/.config/wayvnc/config

Syntax

The configuration file is composed of key-value pairs separated with an equal sign. Whitespace around either the key or the value is insignificant and is not considered to be part of the key or the value.

Keywords

address

The address to which the server shall bind, e.g. 0.0.0.0 or localhost.

certificate_file

The path to the certificate file for encryption. Only applicable when enable_auth=true.

enable_auth

Enable authentication and encryption. Setting this value to true requires also setting certificate_file, private_key_file, username and password.

password

Choose a password for authentication.

port

The port to which the server shall bind. Default is 5900.

private_key_file_file

The path to the private key file for TLS encryption. Only applicable when enable_auth=true.

relax_encryption

Don't require encryption after the user has been authenticated. This enables some security types such as Apple Diffie-Hellman.

rsa_private_key_file

The path to the private key file for RSA-AES encryption. Only applicable when enable_auth=true.

username

Choose a username for authentication.

use_relative_paths

Make file paths relative to the location of the config file.

xkb_layout

The keyboard layout to use for key code lookup.

Default: XKB_DEFAULT_LAYOUT or system default.

xkb_model

The keyboard model by which to interpret keycodes and LEDs.

Default: "pc105"

xkb_options

A comma separated list of options, through which the user specifies non-layout related preferences such as which key is the Compose key.

Default: XKB_DEFAULT_OPTIONS or system default.

xkb_rules

The rules file describes how to interpret the values of the model, layout, variant and options fields.

Default: XKB_DEFAULT_RULES or system default.

xkb_variant

The keyboard variant to use for keycode lookup.

Default: XKB_DEFAULT_VARIANT or system default.

Example

  use_relative_paths=true
  address=0.0.0.0
  enable_auth=true
  username=luser
  password=p455w0rd
  rsa_private_key_file=rsa_key.pem
  private_key_file=tls_key.pem
  certificate_file=tls_cert.pem

Wayvncctl Control Socket

To facilitate runtime interaction and control, wayvnc opens a unix domain socket at $XDG_RUNTIME_DIR/wayvncctl (or a fallback of /tmp/wayvncctl-$UID). A client can connect and exchange json-formatted IPC messages to query and control the running wayvnc instance.

Ipc Commands

HELP

The help command, when issued without any parameters, lists the names of all available commands.

If an optional command parameter refers to one of those commands by name, the response data will be a detailed description of that command and its parameters.

EVENT-RECEIVE

The event-receive command registers for asynchronous server events. See the EVENTS section below for details on the event message format, and the Ipc Events section below for a description of all possible server events.

Event registration registers for all available server events and is scoped to the current connection only. If a client disconnects and reconnects, it must re-register for events.

CLIENT-LIST

The client-list command retrieves a list of all VNC clients currently connected to wayvnc.

CLIENT-DISCONNECT

The client-disconnect command disconnects a single VNC client.

Parameters:

id

Required: The ID of the client to disconnect.  This ID can be found from the GET-CLIENTS command or receipt of a CLIENT-CONNECTED event.

OUTPUT-LIST

The output-list command retrieves a list of all outputs known to wayvnc and whether or not each one is currently being captured.

OUTPUT-CYCLE

For multi-output wayland displays, the output-cycle command switches which output is actively captured by wayvnc. Running this once will switch to the next available output. If no more outputs are available, it cycles back to the first again.

OUTPUT-SET

For multi-output wayland displays, the output-set command switches which output is actively captured by wayvnc by name.

output-name=name

Required: The name of the output to capture next.

VERSION

The version command queries the running wayvnc instance for its version information. Much like the -V option, the response data will contain the version numbers of wayvnc, as well as the versions of the neatvnc and aml components.

WAYVNC-EXIT

The wayvnc-exit command disconnects all clients and shuts down wayvnc.

Ipc Events

CAPTURE_CHANGED

The capture-changed event is sent when the currently captured output changes.

Parameters:

output=...

The name of the output now being captured.

CLIENT-CONNECTED

The client-connected event is sent when a new VNC client connects to wayvnc.

Parameters:

id=...

A unique identifier for this client.

connection_count=...

The total number of connected VNC clients including this one.

address=...

The IP address of this client. May be null.

username=...

The username used to authenticate this client. May be null.

CLIENT-DISCONNECTED

The client-disconnected event is sent when a VNC cliwnt disconnects from wayvnc.

Parameters:

id=...

A unique identifier for this client.

connection_count=...

The total number of connected VNC clients not including this one.

address=...

The IP address of this client. May be null.

username=...

The username used to authenticate this client. May be null.

Ipc Message Format

The wayvncctl(1) command line utility will construct properly-formatted json ipc messages, but any client will work. The client initiates the connection and sends one or more request objects, each of which will receive a corresponding response object.

Note This message format is unstable and may change substantially over the next few releases.

REQUEST

The general form of a json-ipc request message is:

  {
  	"method": "command-name",
  	"id": 123,
  	"params": {
  		"key1": "value1",
  		"key2": "value2",
  	}
  }

The method is the name of the command to be executed. Use the help method to query a list of all valid method names.

The id field is optional and may be any valid json number or string. If provided, the response to this request will contain the identical id value, which the client may use to coordinate multiple requests and responses.

The params object supplies optional parameters on a per-method basis, and may be omitted if empty.

RESPONSE

  {
  	"id": 123,
  	"code": 0,
  	"data": {
  		...
  	}
  }

If the request had an id, the response will have an identical value for id.

The numerical code provides an indication of how the request was handled. A value of 0 always signifies success. Any other value means failure, and varies depending on the method in question.

The data object contains method-specific return data. This may be structured data in response to a query, a simple error string in the case of a failed request, or it may be omitted entirely if the error code alone is sufficient.

EVENTS

Events are aaynchronous messages sent from a server to all registered clients. The message format is identical to a REQUEST, but without an "id" field, and a client must not send a response.

Example event message:

  {
  	"method": "event-name",
  	"params": {
  		"key1": "value1",
  		"key2": "value2",
  	}
  }

In order to receive any events, a client must first register to receive them by sending a event-receive request IPC. Once the success response has been sent by the server, the client must expect that asynchronous event messages may be sent by the server at any time, even between a request and the associated response.

Environment

The following environment variables have an effect on wayvnc:

WAYLAND_DISPLAY

Specifies the name of the Wayland display that the compositor to which wayvnc shall bind is running on.

XDG_CONFIG_HOME

Specifies the location of configuration files.

XDG_RUNTIME_DIR

Specifies the default location for the wayvncctl control socket.

FAQ

Wayvnc complains that a protocol is not supported

The error might look like this:

  wl_registry@2: error 0: invalid version for global zxdg_output_manager_v1 (4): have 2, wanted 3
  ERROR: ../src/main.c: 388: Screencopy protocol not supported by compositor. Exiting. Refer to FAQ section in man page.
  ERROR: ../src/main.c: 1024: Failed to initialise wayland

This means that your wayland compositor does not implement the screencopy protocol and wayvnc won't work with it. Screencopy is implemented by wlroots based compositors such as Sway and Wayfire.

How can I run wayvnc in headless mode/over an SSH session?

Set the environment variables WLR_BACKENDS=headless and WLR_LIBINPUT_NO_DEVICES=1 before starting the compositor, then run wayvnc as normal.

How can I pass my mod-key from Sway to the remote desktop session?

Create an almost empty mode in your sway config. Example:

  mode passthrough {
  	bindsym $mod+Pause mode default
  }
  bindsym $mod+Pause mode passthrough

This makes it so that when you press $mod+Pause, all keybindings, except the one to switch back, are disabled.

Not all symbols show up when I'm typing. What can I do to fix this?

Try setting the keyboard layout in wayvnc to the one that most closely matches the keyboard layout that you're using on the client side. An exact layout isn't needed, just one that has all the symbols that you use.

How do I enable the Compose key?

Set "xkb_options=compose:menu" in the config file. Any key that is not otherwise used will work. There just needs to be some key for wayvnc to match against.

Authors

Maintained by Andri Yngvason <andri@yngvason.is>. Up-to-date sources can be found at https://github.com/any1/wayvnc and bugs reports or patches can be submitted to GitHub's issue tracker.

See Also

wayvncctl(1)

Referenced By

wayvncctl(1).

2024-02-29