;;; GNU Guix --- Functional package management for GNU
;;; Copyright © 2015, 2018 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 system nss)
  #:use-module (rnrs enums)
  #:use-module (guix records)
  #:use-module (srfi srfi-9)
  #:use-module (ice-9 match)
  #:export (name-service-switch?
            name-service-switch
            name-service?
            name-service

            lookup-specification

            %default-nss
            %mdn</td></tr></table>
<table class='tabs'><tr><td>
<a href='/guix/about/'>about</a><a href='/guix/'>summary</a><a href='/guix/refs/?id=da96de3b661723954a6469b70d9cb9cc00e031b3'>refs</a><a href='/guix/log/etc/copyright.el'>log</a><a href='/guix/tree/etc/copyright.el?id=da96de3b661723954a6469b70d9cb9cc00e031b3'>tree</a><a href='/guix/commit/etc/copyright.el?id=da96de3b661723954a6469b70d9cb9cc00e031b3'>commit</a><a class='active' href='/guix/diff/etc/copyright.el?id=da96de3b661723954a6469b70d9cb9cc00e031b3&amp;id2=c162dc379ccbfebcd15ae98791ce4e68249322b7'>diff</a></td><td class='form'><form class='right' method='get' action='/guix/log/etc/copyright.el'>
<input type='hidden' name='id' value='da96de3b661723954a6469b70d9cb9cc00e031b3'/><input type='hidden' name='id2' value='c162dc379ccbfebcd15ae98791ce4e68249322b7'/><select name='qt'>
<option value='grep'>log msg</option>
<option value='author'>author</option>
<option value='committer'>committer</option>
<option value='range'>range</option>
</select>
<input class='txt' type='search' size='10' name='q' value=''/>
<input type='submit' value='search'/>
</form>
</td></tr></table>
<div class='path'>path: <a href='/guix/diff/?id=da96de3b661723954a6469b70d9cb9cc00e031b3&amp;id2=c162dc379ccbfebcd15ae98791ce4e68249322b7'>root</a>/<a href='/guix/diff/etc?id=da96de3b661723954a6469b70d9cb9cc00e031b3&amp;id2=c162dc379ccbfebcd15ae98791ce4e68249322b7'>etc</a>/<a href='/guix/diff/etc/copyright.el?id=da96de3b661723954a6469b70d9cb9cc00e031b3&amp;id2=c162dc379ccbfebcd15ae98791ce4e68249322b7'>copyright.el</a></div><div class='content'><div class='cgit-panel'><b>diff options</b><form method='get'><input type='hidden' name='id' value='da96de3b661723954a6469b70d9cb9cc00e031b3'/><input type='hidden' name='id2' value='c162dc379ccbfebcd15ae98791ce4e68249322b7'/><table><tr><td colspan='2'/></tr><tr><td class='label'>context:</td><td class='ctrl'><select name='context' onchange='this.form.submit();'><option value='1'>1</option><option value='2'>2</option><option value='3' selected='selected'>3</option><option value='4'>4</option><option value='5'>5</option><option value='6'>6</option><option value='7'>7</option><option value='8'>8</option><option value='9'>9</option><option value='10'>10</option><option value='15'>15</option><option value='20'>20</option><option value='25'>25</option><option value='30'>30</option><option value='35'>35</option><option value='40'>40</option></select></td></tr><tr><td class='label'>space:</td><td class='ctrl'><select name='ignorews' onchange='this.form.submit();'><option value='0' selected='selected'>include</option><option value='1'>ignore</option></select></td></tr><tr><td class='label'>mode:</td><td class='ctrl'><select name='dt' onchange='this.form.submit();'><option value='0' selected='selected'>unified</option><option value='1'>ssdiff</option><option value='2'>stat only</option></select></td></tr><tr><td/><td class='ctrl'><noscript><input type='submit' value='reload'/></noscript></td></tr></table></form></div><div class='diffstat-header'><a href='/guix/diff/?id=da96de3b661723954a6469b70d9cb9cc00e031b3&amp;id2=c162dc379ccbfebcd15ae98791ce4e68249322b7'>Diffstat</a> (limited to 'etc/copyright.el')</div><table summary='diffstat' class='diffstat'></table><div class='diffstat-summary'>0 files changed, 0 insertions, 0 deletions</div><table summary='diff' class='diff'><tr><td></td></tr></table></div> <!-- class=content -->
                         <div class=footer>generated by
                             <a href="https://git.zx2c4.com/cgit/about/">
                                 cgit
                             </a>
                         </div>
                        </div> <!-- id=cgit -->
</body>
</html>
lt (list %files))))

(define %default-nss
  ;; Default NSS configuration.
  (name-service-switch))

(define %mdns-host-lookup-nss
  (name-service-switch
    (hosts (list %files                           ;first, check /etc/hosts

                 ;; If the above did not succeed, try with 'mdns_minimal'.
                 (name-service
                   (name "mdns_minimal")

                   ;; 'mdns_minimal' is authoritative for '.local'.  When it
                   ;; returns "not found", no need to try the next methods.
                   (reaction (lookup-specification
                              (not-found => return))))

                 ;; Then fall back to DNS.
                 (name-service
                   (name "dns"))

                 ;; Finally, try with the "full" 'mdns'.
                 (name-service
                   (name "mdns"))))))


;;;
;;; Serialization.
;;;

(define (lookup-status->string status)
  (match status
    ('success     "SUCCESS")
    ('not-found   "NOTFOUND")
    ('unavailable "UNAVAIL")
    ('try-again   "TRYAGAIN")
    (($ <lookup-status-negation> status)
     (string-append "!" (lookup-status->string status)))))

(define lookup-reaction->string
  (match-lambda
   (($ <lookup-reaction> status action)
    (string-append (lookup-status->string status) "="
                   (symbol->string action)))))

(define name-service->string
  (match-lambda
   (($ <name-service> name ())
    name)
   (($ <name-service> name reactions)
    (string-append name " ["
                   (string-join (map lookup-reaction->string reactions))
                   "]"))))

(define (name-service-switch->string nss)
  "Return the 'nsswitch.conf' contents for NSS as a string.  See \"NSS
Configuration File\" in the libc manual."
  (let-syntax ((->string
                (syntax-rules ()
                  ((_ name field)
                   (match (field nss)
                     (()                          ;keep the default config
                      "")
                     ((services (... ...))
                      (string-append name ":\t"
                                     (string-join
                                      (map name-service->string services))
                                     "\n")))))))
    (string-append (->string "aliases"    name-service-switch-aliases)
                   (->string "ethers"     name-service-switch-ethers)
                   (->string "group"      name-service-switch-group)
                   (->string "gshadow"    name-service-switch-gshadow)
                   (->string "hosts"      name-service-switch-hosts)
                   (->string "initgroups" name-service-switch-initgroups)
                   (->string "netgroup"   name-service-switch-netgroup)
                   (->string "networks"   name-service-switch-networks)
                   (->string "passwd"     name-service-switch-password)
                   (->string "publickey"  name-service-switch-public-key)
                   (->string "rpc"        name-service-switch-rpc)
                   (->string "services"   name-service-switch-services)
                   (->string "shadow"     name-service-switch-shadow))))

;;; Local Variables:
;;; eval: (put 'name-service 'scheme-indent-function 0)
;;; eval: (put 'name-service-switch 'scheme-indent-function 0)
;;; End:

;;; nss.scm ends here