;;; GNU Guix --- Functional package management for GNU
;;; Copyright © 2013, 2014, 2015, 2016, 2017, 2019, 2020 Ludovic Courtès <ludo@gnu.org>
;;; Copyright © 2015 Sou Bunnbu <iyzsong@gmail.com>
;;; Copyright © 2021 Maxime Devos <maximedevos@telenet.be>
;;; Copyright © 2021 Brice Waegeneire <brice@waegenei.re>
;;;
;;; 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 dbus)
  #:use-module (gnu services)
  #:use-module (gnu services shepherd)
  #:use-module (gnu system setuid)
  #:use-module (gnu system shadow)
  #:use-module (gnu system pam)
  #:use-module ((gnu packages glib) #:select (dbus))
  #:use-module (gnu packages polkit)
  #:use-module (gnu packages admin)
  #:use-module (guix gexp)
  #:use-module ((guix packages) #:select (package-name))
  #:use-module (guix records)
  #:use-module (guix modules)
  #:use-module (srfi srfi-1)
  #:use-module (ice-9 match)
  #:export (dbus-configuration
            dbus-configuration?
            dbus-root-service-type
            dbus-service
            wrapped-dbus-service

            polkit-service-type
            polkit-service))

;;;
;;; D-Bus.
;;;

(define-record-type* <dbus-configuration>
  dbus-configuration make-dbus-configuration
  dbus-configuration?
  (dbus      dbus-configuration-dbus              ;<package>
             (default dbus))
  (services  dbus-configuration-services          ;list of <package>
             (default '())))

(define (system-service-directory services)
  "Return the system service directory, containing @code{.service} files for
all the services that may be activated by the daemon."
  (computed-file "dbus-system-services"
                 (with-imported-modules '((guix build utils))
                   #~(begin
                       (use-modules (guix build utils)
                                    (srfi srfi-1))

                       (define files
                         (append-map (lambda (service)
                                       (find-files
                                        (string-append
                                         service
                                         "/share/dbus-1/")
                                        "\\.service$"))
                                     (list #$@services)))

                       (mkdir #$output)
                       (for-each (lambda (file)
                                   (symlink file
                                            (string-append #$output "/"
                                                           (basename file))))
                                 files)
                       #t))))

(define (dbus-configuration-directory services)
  "Return a directory contains the @code{system-local.conf} file for DBUS that
includes the @code{etc/dbus-1/system.d} directories of each package listed in
@var{services}."
  (define build
    #~(begin
        (use-modules (sxml simple)
                     (srfi srfi-1))

        (define-syntax directives
          (syntax-rules ()
            ;; Expand the given directives (SXML expressions) only if their
            ;; key names a file that exists.
            ((_ (name directory) rest ...)
             (let ((dir directory))
               (if (file-exists? dir)
                   `((name ,dir)
                     ,@(directives rest ...))
                   (directives rest ...))))
            ((_)
             '())))

        (define (services->sxml services)
          ;; Return the SXML 'includedir' clauses for DIRS.
          `(busconfig
            (servicehelper "/run/setuid-programs/dbus-daemon-launch-helper")

            ;; First, the '.service' files of services subject to activation.
            ;; We use a fixed location under /etc because the setuid helper
            ;; looks for them in that location and nowhere else.  See
            ;; <https://bugs.freedesktop.org/show_bug.cgi?id=92458>.
            (servicedir "/etc/dbus-1/system-services")

            ,@(append-map (lambda (dir)
                            (directives
                             (includedir
                              (string-append dir "/etc/dbus-1/system.d"))
                             (includedir
                              (string-append dir "/share/dbus-1/system.d"))
                             (servicedir          ;for '.service' files
                              (string-append dir "/share/dbus-1/services"))))
                          services)))

        (mkdir #$output)

        ;; Provide /etc/dbus-1/system-services, which is where the setuid
        ;; helper looks for system service files.
        (symlink #$(system-service-directory services)
                 (string-append #$output "/system-services"))

        ;; 'system-local.conf' is automatically included by the default
        ;; 'system.conf', so this is where we stuff our own things.
        (call-with-output-file (string-append #$output "/system-local.conf")
          (lambda (port)
            (sxml->xml (services->sxml (list #$@services))
                       port)))))

  (computed-file "dbus-configuration" build))

(define (dbus-etc-files config)
  "Return a list of FILES for @var{etc-service-type} to build the
@code{/etc/dbus-1} directory."
  (list `("dbus-1" ,(dbus-configuration-directory
                     (dbus-configuration-services config)))))

(define %dbus-accounts
  ;; Accounts used by the system bus.
  (list (user-group (name "messagebus") (system? #t))
        (user-account
         (name "messagebus")
         (group "messagebus")
         (system? #t)
         (comment "D-Bus system bus user")
         (home-directory "/var/run/dbus")
         (shell (file-append shadow "/sbin/nologin")))))

(define dbus-setuid-programs
  ;; Return a list of <setuid-program> for the program that we need.
  (match-lambda
    (($ <dbus-configuration> dbus services)
     (list (setuid-program
            (program (file-append
                      dbus "/libexec/dbus-daemon-launch-helper")))))))

(define (dbus-activation config)
  "Return an activation gexp for D-Bus using @var{config}."
  (with-imported-modules (source-module-closure
                          '((gnu build activation)
                            (guix build utils)))
    #~(begin
        (use-modules (gnu build activation)
                     (guix build utils))

        (let ((user (getpwnam "messagebus")))
          ;; This directory contains the daemon's socket so it must be
          ;; world-readable.
          (mkdir-p/perms "/var/run/dbus" user #o755))

        (unless (file-exists? "/etc/machine-id")
          (format #t "creating /etc/machine-id...~%")
          (invoke (string-append #$(dbus-configuration-dbus config)
                                 "/bin/dbus-uuidgen")
                  "--ensure=/etc/machine-id")))))

(define dbus-shepherd-service
  (match-lambda
    (($ <dbus-configuration> dbus)
     (list (shepherd-service
            (documentation "Run the D-Bus system daemon.")
            (provision '(dbus-system))
            (requirement '(user-processes syslogd))
            (start #~(make-forkexec-constructor
                      (list (string-append #$dbus "/bin/dbus-daemon")
                            "--nofork" "--system" "--syslog-only")
                      #:pid-file "/var/run/dbus/pid"))
            (stop #~(make-kill-destructor)))))))

(define dbus-root-service-type
  (service-type (name 'dbus)
                (extensions
                 (list (service-extension shepherd-root-service-type
                                          dbus-shepherd-service)
                       (service-extension activation-service-type
                                          dbus-activation)
                       (service-extension etc-service-type
                                          dbus-etc-files)
                       (service-extension account-service-type
                                          (const %dbus-accounts))
                       (service-extension setuid-program-service-type
                                          dbus-setuid-programs)))

                ;; Extensions consist of lists of packages (representing D-Bus
                ;; services) that we just concatenate.
                (compose concatenate)

                ;; The service's parameters field is extended by augmenting
                ;; its <dbus-configuration> 'services' field.
                (extend (lambda (config services)
                          (dbus-configuration
                           (inherit config)
                           (services
                            (append (dbus-configuration-services config)
                                    services)))))

                (default-value (dbus-configuration))
                (description "Run the system-wide D-Bus inter-process message
bus.  It allows programs and daemons to communicate and is also responsible
for spawning (@dfn{activating}) D-Bus services on demand.")))

(define* (dbus-service #:key (dbus dbus) (services '()))
  "Return a service that runs the \"system bus\", using @var{dbus}, with
support for @var{services}.

@uref{http://dbus.freedesktop.org/, D-Bus} is an inter-process communication
facility.  Its system bus is used to allow system services to communicate and
be notified of system-wide events.

@var{services} must be a list of packages that provide an
@file{etc/dbus-1/system.d} directory containing additional D-Bus configuration
and policy files.  For example, to allow avahi-daemon to use the system bus,
@var{services} must be equal to @code{(list avahi)}."
  (service dbus-root-service-type
           (dbus-configuration (dbus dbus)
                               (services services))))

(define (wrapped-dbus-service service program variables)
  "Return a wrapper for @var{service}, a package containing a D-Bus service,
where @var{program} is wrapped such that @var{variables}, a list of name/value
tuples, are all set as environment variables when the bus daemon launches it."
  (define wrapper
    (program-file (string-append (package-name service) "-program-wrapper")
                  #~(begin
                      (use-modules (ice-9 match))

                      (for-each (match-lambda
                                  ((variable value)
                                   (setenv variable value)))
                                '#$variables)

                      (apply execl (string-append #$service "/" #$program)
                             (string-append #$service "/" #$program)
                             (cdr (command-line))))))

  (define build
    (with-imported-modules '((guix build utils))
      #~(begin
          (use-modules (guix build utils))

          (define service-directory
            "/share/dbus-1/system-services")

          (mkdir-p (dirname (string-append #$output
                                           service-directory)))
          (copy-recursively (string-append #$service
                                           service-directory)
                            (string-append #$output
                                           service-directory))
          (symlink (string-append #$service "/etc") ;for etc/dbus-1
                   (string-append #$output "/etc"))

          (for-each (lambda (file)
                      (substitute* file
                        (("Exec[[:blank:]]*=[[:blank:]]*([[:graph:]]+)(.*)$"
                          _ original-program arguments)
                         (string-append "Exec=" #$wrapper arguments
                                        "\n"))))
                    (find-files #$output "\\.service$")))))

  (computed-file (string-append (package-name service) "-wrapper")
                 build))


;;;
;;; Polkit privilege management service.
;;;

(define-record-type* <polkit-configuration>
  polkit-configuration make-polkit-configuration
  polkit-configuration?
  (polkit   polkit-configuration-polkit           ;<package>
            (default polkit))
  (actions  polkit-configuration-actions          ;list of <package>
            (default '())))

(define %polkit-accounts
  (list (user-group (name "polkitd") (system? #t))
        (user-account
         (name "polkitd")
         (group "polkitd")
         (system? #t)
         (comment "Polkit daemon user")
         (home-directory "/var/empty")
         (shell "/run/current-system/profile/sbin/nologin"))))

(define %polkit-pam-services
  (list (unix-pam-service "polkit-1")))

(define (polkit-directory packages)
  "Return a directory containing an @file{actions} and possibly a
@file{rules.d} sub-directory, for use as @file{/etc/polkit-1}."
  (with-imported-modules '((guix build union))
    (computed-file "etc-polkit-1"
                   #~(begin
                       (use-modules (guix build union) (srfi srfi-26))

                       (union-build #$output
                                    (map (cut string-append <>
                                              "/share/polkit-1")
                                         (list #$@packages)))))))

(define polkit-etc-files
  (match-lambda
    (($ <polkit-configuration> polkit packages)
     `(("polkit-1" ,(polkit-directory (cons polkit packages)))))))

(define polkit-setuid-programs
  (match-lambda
    (($ <polkit-configuration> polkit)
     (map file-like->setuid-program
         <tr class='logheader'><td><span title='2024-12-18 13:22:47 +0100'>2024-12-18</span></td><td class='logsubject'><a href='/guix/commit/gnu/packages?id=9a7899738ac95866844c938d612a0e1e87da3cf2'>gnu: Add julia-simdtypes.</a></td><td>Spencer King</td></tr>
<tr class='nohover-highlight'><td/><td colspan='3' class='logmsg'>
* gnu/packages/julia-xyz.scm (julia-simdtypes): New variable.

Change-Id: I33f4321abd19b44bc0d04dac45be07624ad55098
Signed-off-by: Ludovic Courtès &lt;ludo@gnu.org&gt;


</td></tr>
<tr class='logheader'><td><span title='2024-12-18 13:22:47 +0100'>2024-12-18</span></td><td class='logsubject'><a href='/guix/commit/gnu/packages?id=e25b491d5e3a6f03527a33c5b74d872b70c0d6f4'>gnu: Add julia-terminterface.</a></td><td>Spencer King</td></tr>
<tr class='nohover-highlight'><td/><td colspan='3' class='logmsg'>
* gnu/packages/julia-xyz.scm (julia-terminterface): New variable.

Change-Id: I22ad743410ff9704e3281440120befc857a10660
Signed-off-by: Ludovic Courtès &lt;ludo@gnu.org&gt;


</td></tr>
<tr class='logheader'><td><span title='2024-12-18 13:22:47 +0100'>2024-12-18</span></td><td class='logsubject'><a href='/guix/commit/gnu/packages?id=24a271684e95d80982c0a1250255215a278ee171'>gnu: isc-dhcp: Fix cross compilation for arm32</a></td><td>Christoph Buck</td></tr>
<tr class='nohover-highlight'><td/><td colspan='3' class='logmsg'>
* gnu/packages/admin.scm (isc-dhcp): Fix cross compilation for arm32

Change-Id: I52a863d2cb44e81e26de3224a7c5f8c6d2420cc6
Signed-off-by: Ludovic Courtès &lt;ludo@gnu.org&gt;


</td></tr>
<tr class='logheader'><td><span title='2024-12-18 12:15:34 +0100'>2024-12-18</span></td><td class='logsubject'><a href='/guix/commit/gnu/packages?id=8c2e41f71725866ee9d3a739ee6599ba08d1e31c'>gnu: python-pygpgme: Fix build.</a></td><td>Danny Milosavljevic</td></tr>
<tr class='nohover-highlight'><td/><td colspan='3' class='logmsg'>
* gnu/packages/gnupg.scm (python-pygpgme)[native-inputs]: Add
python-setuptools, python-wheel.

Change-Id: Ida614c2ddcf8b7f275496a2e56e35ada0eb7667b


</td></tr>
<tr class='logheader'><td><span title='2024-12-18 09:07:27 +0100'>2024-12-18</span></td><td class='logsubject'><a href='/guix/commit/gnu/packages?id=cd018214a3c0319451ab46855ea395b2be6a15dc'>gnu: perl-pdl: Clarify return value.</a></td><td>Danny Milosavljevic</td></tr>
<tr class='nohover-highlight'><td/><td colspan='3' class='logmsg'>
* gnu/packages/patches/pdl-2.019-glut-bitmap-fonts.patch: Modify.

Change-Id: Ib32237ddde43cd0c743