;;; GNU Guix --- Functional package management for GNU
;;; Copyright © 2014-2020, 2022 Ludovic Courtès <ludo@gnu.org>
;;;
;;; 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 avahi)
  #:use-module (gnu services)
  #:use-module (gnu services base)
  #:use-module (gnu services shepherd)
  #:use-module (gnu services dbus)
  #:use-module (gnu system shadow)
  #:use-module (gnu packages avahi)
  #:use-module (gnu packages admin)
  #:use-module (guix deprecation)
  #:use-module (guix records)
  #:use-module (guix gexp)
  #:export (avahi-configuration
            avahi-configuration?

            avahi-configuration-avahi
            avahi-configuration-debug?
            avahi-configuration-host-name
            avahi-configuration-publish?
            avahi-configuration-publish-workstation?
            avahi-configuration-ipv4?
            avahi-configuration-ipv6?
            avahi-configuration-wide-area?
            avahi-configuration-domains-to-browse

            avahi-service-type))

;;; Commentary:
;;;
;;; This module provides service definitions for the Avahi
;;; "zero-configuration" tool set.
;;;
;;; Code:

(define-record-type* <avahi-configuration>
  avahi-configuration make-avahi-configuration
  avahi-configuration?
  (avahi             avahi-configuration-avahi    ;file-like
                     (default avahi))
  (debug?            avahi-configuration-debug?   ;Boolean
                     (default #f))
  (host-name         avahi-configuration-host-name ;string | #f
                     (default #f))
  (publish?          avahi-configuration-publish? ;boolean
                     (default #t))

  ;; The default for this was #t in Avahi 0.6.31 and became #f in 0.7.  For
  ;; now we stick to the old default.
  (publish-workstation? avahi-configuration-publish-workstation? ;Boolean
                        (default #t))

  (ipv4?             avahi-configuration-ipv4?    ;Boolean
                     (default #t))
  (ipv6?             avahi-configuration-ipv6?    ;Boolean
                     (default #t))
  (wide-area?        avahi-configuration-wide-area? ;Boolean
                     (default #f))
  (domains-to-browse avahi-configuration-domains-to-browse ;list of strings
                     (default '())))

(define* (configuration-file config)
  "Return an avahi-daemon configuration file based on CONFIG, an
<avahi-configuration>."
  (define (bool value)
    (if value "yes\n" "no\n"))

  (define host-name (avahi-configuration-host-name config))

  (plain-file "avahi-daemon.conf"
              (string-append
               "[server]\n"
               (if host-name
                   (string-append "host-name=" host-name "\n")
                   "")

               "browse-domains=" (string-join
                                  (avahi-configuration-domains-to-browse
                                   config))
               "\n"
               "use-ipv4=" (bool (avahi-configuration-ipv4? config))
               "use-ipv6=" (bool (avahi-configuration-ipv6? config))
               "[wide-area]\n"
               "enable-wide-area=" (bool (avahi-configuration-wide-area? config))
               "[publish]\n"
               "disable-publishing="
               (bo<tr><td><span title='2022-02-14 11:23:08 +0100'>2022-02-14</span></td><td><a href='/guix/commit/tests/guix-git-authenticate.sh?id=ca87601dd97dd9d356409827802eb0f8a3a535f0'>git-authenticate: Ensure the target is a descendant of the introductory commit.</a><span class='msg-avail'>...<span class='msg-tooltip'>Fixes a bug whereby authentication of a commit *not* descending from the
introductory commit could succeed, provided the commit verifies the
authorization invariant.

In the example below, A is a common ancestor of the introductory commit
I and of commit X.  Authentication of X would succeed, even though it is
not a descendant of I, as long as X is authorized according to the
'.guix-authorizations' in A:

   X   	 I
    \   /
      A

This is because, 'authenticate-repository' would not check whether X
descends from I, and the call (commit-difference X I) would return X.

In practice that only affects forks because it means that ancestors of
the introductory commit already contain a '.guix-authorizations' file.

* guix/git-authenticate.scm (authenticate-repository): Add call to
'commit-descendant?'.
* tests/channels.scm ("authenticate-channel, not a descendant of introductory commit"):
New test.
* tests/git-authenticate.scm ("authenticate-repository, target not a descendant of intro"):
New test.
* tests/guix-git-authenticate.sh: Expect earlier test to fail since
9549f0283a78fe36f2d4ff2a04ef8ad6b0c02604 is not a descendant of
$intro_commit.  Add new test targeting an ancestor of the introductory
commit, and another test targeting the v1.2.0 commit.
* doc/guix.texi (Specifying Channel Authorizations): Add a sentence.
</span></span></td><td>Ludovic Courtès</td></tr>
   "Run @command{avahi-daemon}, a host and service discovery
daemon that implements the multicast DNS (mDNS) and DNS service
discovery (DNS-SD) protocols.  Additionally, extend the C library's name
service switch (NSS) with support for @code{.local} host name resolution.")
                  (extensions
                   (list (service-extension shepherd-root-service-type
                                            avahi-shepherd-service)
                         (service-extension dbus-root-service-type
                                            avahi-package)
                         (service-extension account-service-type
                                            (const %avahi-accounts))
                         (service-extension activation-service-type
                                            (const %avahi-activation))
                         (service-extension nscd-service-type
                                            (const (list nss-mdns)))

                         ;; Provide 'avahi-browse', 'avahi-resolve', etc. in
                         ;; the system profile.
                         (service-extension profile-service-type
                                            avahi-package)))
                  (default-value (avahi-configuration)))))

;;; avahi.scm ends here