Toggle diff (494 lines)
diff --git a/doc/guix.texi b/doc/guix.texi
index b04ec25399..26dcc7fdbe 100644
--- a/doc/guix.texi
+++ b/doc/guix.texi
@@ -17514,6 +17514,7 @@ declaration.
* Web Services:: Web servers.
* Certificate Services:: TLS certificates via Let's Encrypt.
* DNS Services:: DNS daemons.
+* VNC Services:: VNC daemons.
* VPN Services:: VPN daemons.
* Network File System:: NFS related services.
* Continuous Integration:: Cuirass and Laminar services.
@@ -21005,6 +21006,7 @@ started by the @dfn{login manager}, by default the GNOME Display Manager (GDM).
@cindex GDM
@cindex GNOME, login manager
+@anchor{gdm}
GDM of course allows users to log in into window managers and desktop
environments other than GNOME; for those using GNOME, GDM is required for
features such as automatic screen locking.
@@ -21306,6 +21308,7 @@ Relogin after logout.
@cindex lightdm, graphical login manager
@cindex display manager, lightdm
+@anchor{lightdm}
@defvr {Scheme Variable} lightdm-service-type
This is the type of the service to run the
@url{https://github.com/canonical/lightdm,LightDM display manager}. Its
@@ -21509,10 +21512,11 @@ Extra configuration values to append to the seat configuration section.
@cindex Xorg, configuration
@deftp {Data Type} xorg-configuration
-This data type represents the configuration of the Xorg graphical display
-server. Note that there is no Xorg service; instead, the X server is started
-by a ``display manager'' such as GDM, SDDM, and SLiM@. Thus, the configuration
-of these display managers aggregates an @code{xorg-configuration} record.
+This data type represents the configuration of the Xorg graphical
+display server. Note that there is no Xorg service; instead, the X
+server is started by a ``display manager'' such as GDM, SDDM, LightDM or
+SLiM@. Thus, the configuration of these display managers aggregates an
+@code{xorg-configuration} record.
@table @asis
@item @code{modules} (default: @code{%default-xorg-modules})
@@ -30779,6 +30783,157 @@ Defaults to @samp{()}.
@c %end of fragment
+@node VNC Services
+@subsection VNC Services
+@cindex VNC (virtual network computing)
+@cindex XDMCP (x display manager control protocol)
+
+The @code{(gnu services vnc)} module provides services related to
+@dfn{Virtual Network Computing} (VNC), which makes it possible to
+locally use graphical Xorg applications running on a remote machine.
+Combined with a graphical manager that supports the @dfn{X Display
+Manager Control Protocol}, such as GDM (@pxref{gdm}) or LightDM
+(@pxref{lightdm}), it is possible to remote an entire desktop for a
+multi-user environment.
+
+@subsubheading Xvnc
+
+Xvnc is a VNC server that spawns its own X window server; which means it
+can run on headless servers. The Xvnc implementations provided by the
+@code{tigervnc-server} and @code{turbovnc} aim to be fast and efficient.
+
+@defvar {Scheme Variable} xvnc-service-type
+
+The @code{xvnc-server-type} service can be configured via the
+@code{xvnc-configuration} record, documented below. A second virtual
+display could be made available on a remote machine for via the
+following configuration:
+@end defvar
+
+@lisp
+(service xvnc-service-type (xvnc-configuration (display-number 10)
+@end lisp
+
+As a demonstration, the @command{xclock} command could then be started
+on the remote machine on display number 10, and it could be display
+locally via the @command{vncviewer} command:
+@example
+# Start xclock on the remote machine.
+ssh -L5910:localhost:5910 -- guix shell xclock -- env DISPLAY=:10 xclock
+# Access it via VNC.
+guix shell tigervnc-client -- vncviewer localhost:5910
+@end example
+
+The following configuration combines XDMCP and Inetd to allow multiple
+users to concurrently use the remote system, login in graphically via
+the GDM display manager:
+
+@lisp
+(operating-system
+ [...]
+ (services (cons*
+ [...]
+ (service xvnc-service-type (xvnc-configuration
+ (display-number 5)
+ (localhost? #f)
+ (xdmcp? #t)
+ (inetd? #t)))
+ (modify-services %desktop-services
+ (gdm-service-type config => (gdm-configuration
+ (inherit config)
+ (auto-suspend? #f)
+ (xdmcp? #t)))))))
+@end lisp
+
+A remote user could then connect to it by using the @command{vncviewer}
+command or a compatible VNC client and start a desktop session of their
+choosing:
+@example
+vncviewer remote-host:5905
+@end example
+
+@quotation Warning
+Unless your machine is in a controlled environment, for security
+reasons, the @code{localhost?} configuration of the
+@code{xvnc-configuration} record should be left to its default @code{#t}
+value and exposed via a secure means such as an SSH port forward. The
+XDMCP port, UDP 177 should also be blocked from the outside by a
+firewall, as it is not a secure protocol and can expose login
+credentials in clear.
+@end quotation
+
+@c Use (configuration->documentation 'xvnc-configuration) to regenerate
+@c the documentation.
+@c %start of fragment
+@deftp {Data Type} xvnc-configuration
+Available @code{xvnc-configuration} fields are:
+
+@table @asis
+@item @code{xvnc} (default: @code{tigervnc-server}) (type: file-like)
+The package that provides the Xvnc binary.
+
+@item @code{display-number} (default: @code{0}) (type: number)
+The display number used by Xvnc. You should set this to a number not
+already used a Xorg server.
+
+@item @code{geometry} (default: @code{"1024x768"}) (type: string)
+The size of the desktop to be created.
+
+@item @code{depth} (default: @code{24}) (type: color-depth)
+The pixel depth in bits of the desktop to be created. Accepted values
+are 16, 24 or 32.
+
+@item @code{port} (type: maybe-port)
+The port on which to listen for connections from viewers. When left
+unspecified, it defaults to 5900 plus the display number.
+
+@item @code{ipv4?} (default: @code{#t}) (type: boolean)
+Use IPv4 for incoming and outgoing connections.
+
+@item @code{ipv6?} (default: @code{#t}) (type: boolean)
+Use IPv6 for incoming and outgoing connections.
+
+@item @code{password-file} (type: maybe-string)
+The password file to use, if any. Refer to vncpasswd(1) to learn how to
+generate such a file.
+
+@item @code{xdmcp?} (default: @code{#f}) (type: boolean)
+Query the XDMCP server for a session. This enables users to log in a
+desktop session from the login manager screen. For a multiple users
+scenario, you'll want to enable the @code{inetd?} option as well, so
+that each connection to the VNC server is handled separately rather than
+shared.
+
+@item @code{inetd?} (default: @code{#f}) (type: boolean)
+Use an Inetd-style service, which runs the Xvnc server on demand.
+
+@item @code{frame-rate} (default: @code{60}) (type: number)
+The maximum number of updates per second sent to each client.
+
+@item @code{security-types} (default: @code{("None")}) (type: security-types)
+The allowed security schemes to use for incoming connections. The
+default is "None", which is safe given that Xvnc is configured to
+authenticate the user via the display manager, and only for local
+connections. Accepted values are any of the following: ("None"
+"VncAuth" "Plain" "TLSNone" "TLSVnc" "TLSPlain" "X509None" "X509Vnc")
+
+@item @code{localhost?} (default: @code{#t}) (type: boolean)
+Only allow connections from the same machine. It is set to #true by
+default for security, which means SSH or another secure means should be
+used to expose the remote port.
+
+@item @code{log-level} (default: @code{30}) (type: log-level)
+The log level, a number between 0 and 100, 100 meaning most verbose
+output. The log messages are output to syslog.
+
+@item @code{extra-options} (default: @code{()}) (type: strings)
+This can be used to provide extra Xvnc options not exposed via this
+<xvnc-configuration> record.
+
+@end table
+
+@end deftp
+@c %end of fragment
@node VPN Services
@subsection VPN Services
diff --git a/gnu/local.mk b/gnu/local.mk
index ef1bae5f3c..eaccf763c7 100644
--- a/gnu/local.mk
+++ b/gnu/local.mk
@@ -689,6 +689,7 @@ GNU_SYSTEM_MODULES = \
%D%/services/sysctl.scm \
%D%/services/telephony.scm \
%D%/services/version-control.scm \
+ %D%/services/vnc.scm \
%D%/services/vpn.scm \
%D%/services/web.scm \
%D%/services/xorg.scm \
@@ -768,6 +769,7 @@ GNU_SYSTEM_MODULES = \
%D%/tests/telephony.scm \
%D%/tests/version-control.scm \
%D%/tests/virtualization.scm \
+ %D%/tests/vnc.scm \
%D%/tests/web.scm
INSTALLER_MODULES = \
diff --git a/gnu/services/vnc.scm b/gnu/services/vnc.scm
new file mode 100644
index 0000000000..15c3c14fee
--- /dev/null
+++ b/gnu/services/vnc.scm
@@ -0,0 +1,247 @@
+;;; GNU Guix --- Functional package management for GNU
+;;; Copyright © 2022 Maxim Cournoyer <maxim.cournoyer@gmail.com>
+;;;
+;;; This file is part of GNU Guix.
+;;;
+;;; GNU Guix is free software; you can redistribute it and/or modify it
+;;; under the terms of the GNU General Public License as published by
+;;; the Free Software Foundation; either version 3 of the License, or (at
+;;; your option) any later version.
+;;;
+;;; GNU Guix is distributed in the hope that it will be useful, but
+;;; WITHOUT ANY WARRANTY; without even the implied warranty of
+;;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+;;; GNU General Public License for more details.
+;;;
+;;; You should have received a copy of the GNU General Public License
+;;; along with GNU Guix. If not, see <http://www.gnu.org/licenses/>.
+
+(define-module (gnu services vnc)
+ #:use-module (gnu packages vnc)
+ #:use-module ((gnu services) #:hide (delete))
+ #:use-module (gnu system shadow)
+ #:use-module (gnu services configuration)
+ #:use-module (gnu services shepherd)
+ #:use-module (guix gexp)
+ #:use-module (guix records)
+
+ #:export (xvnc-configuration
+ xvnc-configuration-xvnc
+ xvnc-configuration-display-number
+ xvnc-configuration-geometry
+ xvnc-configuration-depth
+ xvnc-configuration-port
+ xvnc-configuration-ipv4?
+ xvnc-configuration-ipv6?
+ xvnc-configuration-password-file
+ xvnc-configuration-xdmcp?
+ xvnc-configuration-inetd?
+ xvnc-configuration-frame-rate
+ xvnc-configuration-security-types
+ xvnc-configuration-localhost?
+ xvnc-configuration-log-level
+ xvnc-configuration-extra-options
+
+ xvnc-service-type))
+
+;;;
+;;; Xvnc.
+;;;
+
+(define (color-depth? x)
+ (member x '(16 24 32)))
+
+(define (port? x)
+ (and (number? x)
+ (and (>= x 0) (<= x 65535))))
+
+(define-maybe/no-serialization port)
+
+(define-maybe/no-serialization string)
+
+(define %security-types '("None" "VncAuth" "Plain" "TLSNone" "TLSVnc" "TLSPlain"
+ "X509None" "X509Vnc"))
+
+(define (security-type? x)
+ (member x %security-types))
+
+(define (security-types? x)
+ (and (list? x)
+ (and-map security-type? x)))
+
+(define (log-level? x)
+ (and (number? x)
+ (and (>= x 0) (<= x 100))))
+
+(define (strings? x)
+ (and (list? x)
+ (and-map string? x)))
+
+(define-configuration/no-serialization xvnc-configuration
+ (xvnc
+ (file-like tigervnc-server)
+ "The package that provides the Xvnc binary.")
+ (display-number
+ (number 0)
+ "The display number used by Xvnc. You should set this to a number not
+already used by a Xorg server. When remoting a complete desktop session via
+XDMCP and using a compatible VNC viewer as provided by the
+@code{tigervnc-client} or @code{turbovnc} packages, the geometry is
+automatically adjusted.")
+ (geometry
+ (string "1024x768")
+ "The size of the desktop to be created.")
+ (depth
+ (color-depth 24)
+ "The pixel depth in bits of the desktop to be created. Accepted values are
+16, 24 or 32.")
+ (port
+ maybe-port
+ "The port on which to listen for connections from viewers. When left
+unspecified, it defaults to 5900 plus the display number.")
+ (ipv4?
+ (boolean #t)
+ "Use IPv4 for incoming and outgoing connections.")
+ (ipv6?
+ (boolean #t)
+ "Use IPv6 for incoming and outgoing connections.")
+ (password-file
+ maybe-string
+ "The password file to use, if any. Refer to vncpasswd(1) to learn how to
+generate such a file.")
+ (xdmcp?
+ (boolean #f)
+ "Query the XDMCP server for a session. This enables users to log in a
+desktop session from the login manager screen. For a multiple users scenario,
+you'll want to enable the @code{inetd?} option as well, so that each
+connection to the VNC server is handled separately rather than shared.")
+ (inetd?
+ (boolean #f)
+ "Use an Inetd-style service, which runs the Xvnc server on demand.")
+ (frame-rate
+ (number 60)
+ "The maximum number of updates per second sent to each client.")
+ (security-types
+ (security-types (list "None"))
+ (format #f "The allowed security schemes to use for incoming connections.
+The default is \"None\", which is safe given that Xvnc is configured to
+authenticate the user via the display manager, and only for local connections.
+Accepted values are any of the following: ~s" %security-types))
+ (localhost?
+ (boolean #t)
+ "Only allow connections from the same machine. It is set to @code{#true}
+by default for security, which means SSH or another secure means should be
+used to expose the remote port.")
+ (log-level
+ (log-level 30)
+ "The log level, a number between 0 and 100, 100 meaning most verbose
+output. The log messages are output to syslog.")
+ (extra-options
+ (strings '())
+ "This can be used to provide extra Xvnc options not exposed via this
+<xvnc-configuration> record."))
+
+(define (xvnc-configuration->command-line-arguments config)
+ "Derive the command line arguments to used to launch the Xvnc daemon from
+CONFIG, a <xvnc-configuration> object."
+ (match-record config <xvnc-configuration>
+ (xvnc display-number geometry depth port ipv4? ipv6? password-file xdmcp?
+ inetd? frame-rate security-types localhost? log-level extra-options)
+ #~(list #$(file-append xvnc "/bin/Xvnc")
+ #$(format #f ":~a" display-number)
+ "-geometry" #$geometry
+ "-depth" #$(number->string depth)
+ #$@(if inetd?
+ (list "-inetd")
+ '())
+ #$@(if (not inetd?)
+ (if (maybe-value-set? port)
+ (list "-rfbport" (number->string port))
+ '())
+ '())
+ #$@(if (not inetd?)
+ (if ipv4?
+ (list "-UseIPv4")
+ '())
+ '())
+ #$@(if (not inetd?)
+ (if ipv6?
+ (list "-UseIPv6")
+ '())
+ '())
+ #$@(if (maybe-value-set? password-file)
+ (list "-PasswordFile" password-file)
+ '())
+ "-FrameRate" #$(number->string frame-rate)
+ "-SecurityTypes" #$(string-join security-types ",")
+ #$@(if localhost?
+ (list "-localhost")
+ '())
+ "-Log" #$(format #f "*:syslog:~a" log-level)
+ #$@(if xdmcp?
+ (list "-query" "localhost" "-once")
+ '())
+ #$@extra-options)))
+
+(define %xvnc-accounts
+ (list (user-group
+ (name "xvnc")
+ (system? #t))
+ (user-account
+ (name "xvnc")
+ (group "xvnc")
+ (system? #t)
+ (comment "User for Xvnc server"))))
+
+(define (xvnc-shepherd-service config)
+ "Return a <shepherd-service> for Xvnc with CONFIG."
+ (let* ((display-number (xvnc-configuration-display-number config))
+ (port (if (maybe-value-set? (xvnc-configuration-port config))
+ (xvnc-configuration-port config)
+ #f))
+ (port* (or port (+ 5900 display-number))))
+ (shepherd-service
+ (provision '(xvnc vncserver))
+ (documentation "Run the Xvnc server.")
+ (requirement '(networking syslogd))
+ (start (if (xvnc-configuration-inetd? config)
+ #~(let* ((inaddr (if #$(xvnc-configuration-localhost? config)
+ INADDR_LOOPBACK
+ INADDR_ANY))
+ (in6addr (if #$(xvnc-configuration-localhost? config)
+ IN6ADDR_LOOPBACK
+ IN6ADDR_ANY))
+ (ipv4-socket (and #$(xvnc-configuration-ipv4? config)
+ (make-socket-address AF_INET inaddr
+ #$port*)))
+ (ipv6-socket (and #$(xvnc-configuration-ipv6? config)
+ (make-socket-address AF_INET6 in6addr
+ #$port*))))
+ (make-inetd-constructor
+ #$(xvnc-configuration->command-line-arguments config)
+ `(,@(if ipv4-socket
+ (list (endpoint ipv4-socket))
+ '())
+ ,@(if ipv6-socket
+ (list (endpoint ipv6-socket))
+ '()))
+ #:user "xvnc"
+ #:group "xvnc"))
+ #~(make-forkexec-constructor
+ #$(xvnc-configuration->command-line-arguments config)
+ #:user "xvnc"
+ #:group "xvnc")))
+ (stop #~(make-inetd-destructor)))))
+
+(define xvnc-service-type
+ (service-type
+ (name 'xvnc)
+ (default-value (xvnc-configuration))
+ (description "Run the Xvnc server, which creates a virtual X11 session and
+allow remote clients connecting to it via the remote framebuffer (RFB)
+protocol.")
+ (extensions (list (service-extension
+ shepherd-root-service-type
+ (compose list xvnc-shepherd-service))
+ (service-extension account-service-type
+ (const %xvnc-accounts))))))
diff --git a/gnu/tests/vnc.scm b/gnu/tests/vnc.scm
new file mode 100644
index 0000000000..34c2db1203
--- /dev/null
+++ b/gnu/tests/vnc.scm
@@ -0,0 +1,200 @@
+;;; GNU Guix --- Functional package management for GNU
+;;; Copyright © 2022 Maxim Cournoyer <maxim.cournoyer@gmail.com>.
+;;;
+;;; This file is part of GNU Guix.
+;;;
+;;; GNU Guix is free software; you can redistribute it and/or modify it
+;;; under the terms of the GNU General Public License as published by
+;;; the Free Software Foundation; either version 3 of the License, or (at
+;;; your option) any later version.
+;;;
+;;; GNU Guix is distributed in the hope that it will be useful, but
+;;; WITHOUT ANY WARRANTY; without even the implied warranty of
+;;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See th
