code:
;;; GNU Guix --- Functional package management for GNU
;;; Copyright © 2016, 2017, 2018, 2019 Ludovic Courtès <ludo@gnu.org>
;;; Copyright © 2017, 2020 Mathieu Othacehe <m.othacehe@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 herd)
  #:use-module (srfi srfi-1)
  #:use-module (srfi srfi-9)
  #:use-module (srfi srfi-11)
  #:use-module (srfi srfi-34)
  #:use-module (srfi srfi-35)
  #:use-module (ice-9 match)
  #:export (%shepherd-socket-file
            shepherd-message-port

            shepherd-error?
            service-not-found-error?
            service-not-found-error-service
            action-not-found-error?
            action-not-found-error-service
            action-not-found-error-action
            action-exception-error?
            action-exception-error-service
            action-exception-error-action
            action-exception-error-key
            action-exception-error-arguments
            unknown-shepherd-error?
            unknown-shepherd-error-sexp

            live-service
            live-service?
            live-service-provision
            live-service-requirement
            live-service-running
            live-service-canonical-name

            with-shepherd-action
            current-services
            unload-services
            unload-service
            load-services
            load-services/safe
            start-service
            stop-service
            restart-service))

;;; Commentary:
;;;
;;; This module provides an interface to the GNU Shepherd, similar to the
;;; 'herd' command.  Essentially it implements a subset of the (shepherd comm)
;;; module, but focusing only on the parts relevant to 'guix system
;;; reconfigure'.
;;;
;;; Code:

(define %shepherd-socket-file
  (make-parameter "/var/run/shepherd/socket"))

(define* (open-connection #:optional (file (%shepherd-socket-file)))
  "Open a connection to the daemon, using the Unix-domain socket at FILE, and
return the socket."
  ;; The protocol is sexp-based and UTF-8-encoded.
  (with-fluids ((%default-port-encoding "UTF-8"))
    (let ((sock    (socket PF_UNIX SOCK_STREAM 0))
          (address (make-socket-address PF_UNIX file)))
      (catch 'system-error
        (lambda ()
          (connect sock address)
          (setvbuf sock 'block 1024)
          sock)
        (lambda args
          (close-port sock)
          (apply throw args))))))

(define-syntax-rule (with-shepherd connection body ...)
  "Evaluate BODY... with CONNECTION bound to an open socket to PID 1."
  (let ((connection (open-connection)))
    (dynamic-wind
      (const #t)
      (lambda ()
        body ...)
      (lambda ()
        (close-port connection)))))

(define-condition-type &shepherd-error &error
  shepherd-error?)

(define-condition-type &service-not-found-error &shepherd-error
  service-not-found-error?
  (service service-not-found-error-service))

(define-condition-type &action-not-found-error &shepherd-error
  action-not-found-error?
  (service action-not-found-error-service)
  (action  action-not-found-error-action))

(define-condition-type &action-exception-error &shepherd-error
  action-exception-error?
  (service action-exception-error-service)
  (action  action-exception-error-action)
  (key     action-exception-error-key)
  (args    action-exception-error-arguments))

(define-condition-type &unknown-shepherd-error &shepherd-error
  unknown-shepherd-error?
  (sexp   unknown-shepherd-error-sexp))

(define (raise-shepherd-error error)
  "Raise an error condition corresponding to ERROR, an sexp received by a
shepherd client in reply to COMMAND, a command object.  Return #t if ERROR
does not denote an error."
  (match error
    (('error ('version 0 x ...) 'service-not-found service)
     (raise (condition (&service-not-found-error
                        (service service)))))
    (('error ('version 0 x ...) 'action-not-found action service)
     (raise (condition (&action-not-found-error
                        (service service)
                        (action action)))))
    (('error ('version 0 x ...) 'action-exception action service
             key (args ...))
     (raise (condition (&action-exception-error
                        (service service)
                        (action action)
                        (key key) (args args)))))
    (('error . _)
     (raise (condition (&unknown-shepherd-error (sexp error)))))
    (#f                                           ;not an error
     #t)))

(define shepherd-message-port
  ;; Port where messages coming from shepherd are printed.
  (make-parameter (current-error-port)))

(define (display-message message)
  (format (shepherd-message-port) "shepherd: ~a~%" message))

(define* (invoke-action service action arguments cont)
  "Invoke ACTION on SERVICE with ARGUMENTS.  On success, call CONT with the
list of results (one result per instance with the name SERVICE).  Otherwise
return #f."
  (with-shepherd sock
    (write `(shepherd-command (version 0)
                              (action ,action)
                              (service ,service)
                              (arguments ,arguments)
                              (directory ,(getcwd)))
           sock)
    (force-output sock)

    (match (read sock)
      (('reply ('version 0 _ ...) ('result result) ('error #f)
               ('messages messages))
       (for-each display-message messages)
       (cont result))
      (('reply ('version 0 x ...) ('result y) ('error error)
               ('messages messages))
       (for-each display-message messages)
       (raise-shepherd-error error)
       #f)
      (x
       ;; invalid reply
       #f))))

(define-syntax-rule (with-shepherd-action service (action args ...)
                      result body ...)
  "Invoke ACTION on SERVICE with the given ARGS, and evaluate BODY with RESULT
bound to the action's result."
  (invoke-action service action (list args ...)
                 (lambda (result) body ...)))

(define-syntax alist-let*
  (syntax-rules ()
    "Bind the given KEYs in EXP to the corresponding items in ALIST.  ALIST
is assumed to be a list of two-element tuples rather than a traditional list
of pairs."
    ((_ alist (key ...) exp ...)
     (let ((key (and=> (assoc-ref alist 'key) car)) ...)
       exp ...))))

;; Information about live Shepherd services.
(define-record-type <live-service>
  (live-service provision requirement running)
  live-service?
  (provision    live-service-provision)           ;list of symbols
  (requirement  live-service-requirement)         ;list of symbols
  (running      live-service-running))            ;#f | object

(define (live-service-canonical-name service)
  "Return the 'canonical name' of SERVICE."
  (first (live-service-provision service)))

(define (current-services)
  "Return the list of currently defined Shepherd services, represented as
<live-service> objects.  Return #f if the list of services could not be
obtained."
  (with-shepherd-action 'root ('status) results
    ;; We get a list of results, one for each service with the name 'root'.
    ;; In practice there's only one such service though.
    (match results
      ((services _ ...)
       (match services
         ((('service ('version 0 _ ...) _ ...) ...)
          (map (lambda (service)
                 (alist-let* service (provides requires running)
                   (live-service provides requires running)))
               services))
         (x
          #f))))))

(define (unload-service service)
  "Unload SERVICE, a symbol name; return #t on success."
  (with-shepherd-action 'root ('unload (symbol->string service)) result
    (first result)))

(define (%load-file file)
  "Load FILE in the Shepherd."
  (with-shepherd-action 'root ('load file) result
    (first result)))

(define (eval-there exp)
  "Eval EXP in the Shepherd."
  (with-shepherd-action 'root ('eval (object->string exp)) result
    (first result)))

(define (load-services files)
  "Load and register the services from FILES, where FILES contain code that
returns a shepherd <service> object."
  (eval-there `(register-services
                ,@(map (lambda (file)
                         `(primitive-load ,file))
                       files))))

(define (load-services/safe files)
  "This is like 'load-services', but make sure only the subset of FILES that
can be safely reloaded is actually reloaded.

This is done to accommodate the Shepherd < 0.15.0 where services lacked the
'replacement' slot, and where 'register-services' would throw an exception
when passed a service with an already-registered name."
  (eval-there `(let* ((services     (map primitive-load ',files))
                      (slots        (map slot-definition-name
                                         (class-slots <service>)))
                      (can-replace? (memq 'replacement slots)))
                 (define (registered? service)
                   (not (null? (lookup-services (canonical-name service)))))

                 (apply register-services
                        (if can-replace?
                            services
                            (remove registered? services))))))

(define* (start-service name #:optional (arguments '()))
  (invoke-action name 'start arguments
                 (lambda (result)
                   result)))

(define (stop-service name)
  (with-shepherd-action name ('stop) result
    result))

(define (restart-service name)
  (with-shepherd-action name ('restart) result
    result))

;; Local Variables:
;; eval: (put 'alist-let* 'scheme-indent-function 2)
;; eval: (put 'with-shepherd 'scheme-indent-function 1)
;; eval: (put 'with-shepherd-action 'scheme-indent-function 3)
;; End:

;;; herd.scm ends here


code:
;;; GNU Guix --- Functional package management for GNU
;;; Copyright © 2020 Jan (janneke) Nieuwenhuizen <janneke@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 hurd)
  #:use-module (gnu packages admin)
  #:use-module (gnu packages hurd)
  #:use-module (gnu services)
  #:use-module (gnu services shepherd)
  #:use-module (gnu system)
  #:use-module (guix gexp)
  #:use-module (guix records)
  #:export (hurd-console-configuration
            hurd-console-service-type
            hurd-getty-configuration
            hurd-getty-service-type))

;;; Commentary:
;;;
;;; This module implements services for the Hurd.
;;;
;;; Code:

;;;
;;; The Hurd VGA console service.
;;;

(define-record-type* <hurd-console-configuration>
  hurd-console-configuration make-hurd-console-configuration
  hurd-console-configuration?
  (hurd   hurd-console-configuration-hurd ;package
          (default hurd)))

(define (hurd-console-shepherd-service config)
  "Return a <shepherd-service> for a Hurd VGA console with CONFIG."

  (define console-command
    #~(list
       (string-append #$(hurd-console-configuration-hurd config) "/bin/console")
       "-c" "/dev/vcs"
       "-d" "vga"
       "-d" "pc_kbd"
       "-d" "generic_speaker"))

  (list (shepherd-service
         (documentation "Run the Hurd’s VGA console client.")
         (provision '(console))
         (requirement '(user-processes))
         (start #~(make-forkexec-constructor #$console-command))
         (stop #~(make-kill-destructor)))))

(define hurd-console-service-type
  (service-type
   (name 'console)
   (description "Run the Hurd console client.")
   (extensions
    (list (service-extension shepherd-root-service-type
                             hurd-console-shepherd-service)))
   (default-value (hurd-console-configuration))))

;;;
;;; The Hurd getty service.
;;;

(define-record-type* <hurd-getty-configuration>
  hurd-getty-configuration make-hurd-getty-configuration
  hurd-getty-configuration?
  (hurd       hurd-getty-configuration-hurd  ;<package>
              (default hurd))
  (tty        hurd-getty-configuration-tty)  ;string
  (baud-rate  hurd-getty-configuration-baud-rate
              (default 38400)))              ;integer

(define (hurd-getty-shepherd-service config)
  "Return a <shepherd-service> for a Hurd getty with CONFIG."

  (let ((hurd      (hurd-getty-configuration-hurd config))
        (tty       (hurd-getty-configuration-tty config))
        (baud-rate (hurd-getty-configuration-baud-rate config)))

    (define getty-command
      #~(list
         (string-append #$hurd "/libexec/getty")
         #$(number->string baud-rate)
         #$tty))

    (list
     (shepherd-service
      (documentation "Run getty on a tty.")
      (provision (list (string->symbol (string-append "term-" tty))))
      (requirement '(user-processes console))
      (start #~(make-forkexec-constructor #$getty-command))
      (stop  #~(make-kill-destructor))))))

(define hurd-getty-service-type
  (service-type
   (name 'getty)
   (extensions (list (service-extension shepherd-root-service-type
                                        hurd-getty-shepherd-service)))
   (description
    "Provide console login using the Hurd @command{getty} program.")))

;;; hurd.scm ends here

repo_name: maximed/guix

license: mit


code:
;;; GNU Guix --- Functional package management for GNU
;;; Copyright © 2016 John Darrington <jmd@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 kerberos)
  #:use-module (gnu services)
  #:use-module (gnu services configuration)
  #:use-module (gnu system pam)
  #:use-module (guix gexp)
  #:use-module (guix records)
  #:use-module (srfi srfi-1)
  #:use-module (srfi srfi-34)
  #:use-module (srfi srfi-35)
  #:use-module (ice-9 match)
  #:export (pam-krb5-configuration
            pam-krb5-configuration?
            pam-krb5-service-type

            krb5-realm
            krb5-realm?

            krb5-configuration
            krb5-configuration?
            krb5-service-type))

(define unset-field (list 'unset-field))

(define (predicate/unset pred)
  (lambda (x) (or (eq? x unset-field) (pred x))))

(define string/unset? (predicate/unset string?))
(define boolean/unset? (predicate/unset boolean?))
(define integer/unset? (predicate/unset integer?))

(define (uglify-field-name field-name)
  "Return FIELD-NAME with all instances of '-' replaced by '_' and any
trailing '?' removed."
  (let ((str (symbol->string field-name)))
    (string-join (string-split (if (string-suffix? "?" str)
                                   (substring str 0 (1- (string-length str)))
                                   str)
                               #\-)
                 "_")))

(define (serialize-field* field-name val)
  (format #t "~a = ~a\n" (uglify-field-name field-name) val))

(define (serialize-string/unset field-name val)
  (unless (eq? val unset-field)
      (serialize-field* field-name val)))

(define (serialize-integer/unset field-name val)
  (unless (eq? val unset-field)
      (serialize-field* field-name val)))

(define (serialize-boolean/unset field-name val)
  (unless (eq? val unset-field)
      (serialize-field* field-name
                        (if val "true" "false"))))

;; An end-point is an address such as "192.168.0.1"
;; or an address port pair ("foobar.example.com" . 109)
(define (end-point? val)
  (match val
    ((? string?) #t)
    (((? string?) . (? integer?)) #t)
    (_ #f)))

(define (serialize-end-point field-name val)
  (serialize-field* field-name
                    (match val
                      ((host . port)
                       ;; The [] are needed in the case of IPv6 addresses
                       (format #f "[~a]:~a" host port))
                      (host
                       (format #f "~a" host)))))

(define (serialize-space-separated-string-list/unset field-name val)
  (unless (eq? val unset-field)
      (serialize-field* field-name (string-join val " "))))

(define (space-separated-string-list? val)
  (and (list? val)
       (and-map (lambda (x)
                  (and (string? x) (not (string-index x #\space))))
                val)))

(define space-separated-string-list/unset?
  (predicate/unset space-separated-string-list?))

(define comma-separated-integer-list/unset?
  (predicate/unset (lambda (val)
                     (and (list? val)
                          (and-map (lambda (x) (integer? x))
                                   val)))))

(define (serialize-comma-separated-integer-list/unset field-name val)
  (unless (eq? val unset-field)
      (serialize-field* field-name
                       (string-drop ; Drop the leading comma
                        (fold
                         (lambda (i prev)
                           (string-append prev "," (number->string i)))
                         "" val) 1))))

(define file-name? (predicate/unset
                    (lambda (val)
                      (string-prefix? "/" val))))

(define (serialize-field field-name val)
  (format #t "~a ~a\n" (uglify-field-name field-name) val))

(define (serialize-string field-name val)
  (serialize-field field-name val))

(define (serialize-file-name field-name val)
  (unless (eq? val unset-field)
    (serialize-string field-name val)))

(define (serialize-space-separated-string-list field-name val)
  (serialize-field field-name (string-join val " ")))

(define (non-negative-integer? val)
  (and (exact-integer? val) (not (negative? val))))

(define (serialize-non-negative-integer/unset field-name val)
  (unless (eq? val unset-field)
    (serialize-field* field-name val)))

(define (free-form-fields? val)
  (match val
    (() #t)
    ((((? symbol?) . (? string)) . val) (free-form-fields? val))
    (_ #f)))

(define (serialize-free-form-fields field-name val)
  (for-each (match-lambda ((k . v) (serialize-field* k v))) val))

(define non-negative-integer/unset? (predicate/unset non-negative-integer?))

(define (realm-list? val)
  (and (list? val)
       (and-map (lambda (x) (krb5-realm? x)) val)))

(define (serialize-realm-list field-name val)
  (format #t "\n[~a]\n" field-name)
  (for-each (lambda (realm)
              (format #t "\n~a = {\n" (krb5-realm-name realm))
              (for-each (lambda (field)
                          (unless (eq? 'name (configuration-field-name field))
                            ((configuration-field-serializer field)
                             (configuration-field-name field)
                             ((configuration-field-getter field)
                              realm)))) krb5-realm-fields)

              (format #t "}\n")) val))

;; For a more detailed explanation of these fields see man 5 krb5.conf
(define-configuration krb5-realm
  (name
   (string/unset unset-field)
   "The name of the realm.")

  (kdc
   (end-point unset-field)
   "The host and port on which the realm's Key Distribution Server listens.")

  (admin-server
   (string/unset unset-field)
   "The Host running the administration server for the realm.")

  (master-kdc
   (string/unset unset-field)
   "If an attempt to get credentials fails because of an invalid password,
the client software will attempt to contact the master KDC.")

  (kpasswd-server
   (string/unset unset-field)
   "The server where password changes are performed.")

  (auth-to-local
   (free-form-fields '())
   "Rules to map between principals and local users.")

  (auth-to-local-names
   (free-form-fields '())
   "Explicit mappings between principal names and local user names.")

  (http-anchors
   (free-form-fields '())
   "Useful only when http proxy is used to access KDC or KPASSWD.")

  ;; The following are useful only for working with V4 services
  (default-domain
    (string/unset unset-field)
    "The domain used to expand host names when translating Kerberos 4 service
principals to Kerberos 5 principals")

  (v4-instance-convert
   (free-form-fields '())
   "Exceptions to the default-domain mapping rule.")

  (v4-realm
   (string/unset unset-field)
   "Used  when the V4 realm name and the V5 realm name are not the same, but
still share the same principal names and passwords"))

;; For a more detailed explanation of these fields see man 5 krb5.conf
(define-configuration krb5-configuration
  (allow-weak-crypto?
   (boolean/unset unset-field)
   "If true, permits access to services which only offer weak encryption.")

  (ap-req-checksum-type
   (non-negative-integer/unset unset-field)
   "The type of the AP-REQ checksum.")

  (canonicalize?
   (boolean/unset unset-field)
   "Should principals in initial ticket requests be canonicalized?")

  (ccache-type
   (non-negative-integer/unset unset-field)
   "The format of the credential cache type.")

  (clockskew
   (non-negative-integer/unset unset-field)
   "Maximum allowable clock skew in seconds (default 300).")

  (default-ccache-name
    (file-name unset-field)
    "The name of the default credential cache.")

  (default-client-keytab-name
    (file-name unset-field)
    "The name of the default keytab for client credentials.")

  (default-keytab-name
    (file-name unset-field)
    "The name of the default keytab file.")

  (default-realm
    (string/unset unset-field)
    "The realm to be accessed if not explicitly specified by clients.")

  (default-tgs-enctypes
    (free-form-fields '())
    "Session key encryption types when making TGS-REQ requests.")

  (default-tkt-enctypes
    (free-form-fields '())
    "Session key encryption types when making AS-REQ requests.")

  (dns-canonicalize-hostname?
   (boolean/unset  unset-field)
   "Whether name lookups will be used to canonicalize host names for use in
service principal names.")

  (dns-lookup-kdc?
   (boolean/unset unset-field)
 "Should DNS SRV records should be used to locate the KDCs and other servers
not appearing in the realm specification")

  (err-fmt
   (string/unset unset-field)
   "Custom error message formatting. If not #f error messages will be formatted
by substituting a normal error message for %M and an error code for %C in the
value.")

  (forwardable?
   (boolean/unset unset-field)
   "Should initial tickets be forwardable by default?")

  (ignore-acceptor-hostname?
   (boolean/unset unset-field)
   "When accepting GSSAPI or krb5 security contexts for host-based service
principals, ignore any hostname passed by the calling application, and allow
clients to authenticate to any service principal in the keytab matching the
service name and realm name.")

  (k5login-authoritative?
   (boolean/unset unset-field)
   "If this flag is true, principals must be listed in a local user's k5login
file to be granted login access, if a ~/.k5login file exists.")

  (k5login-directory
   (string/unset unset-field)
   "If not #f, the library will look for a local user's @file{k5login} file
within the named directory (instead of the user's home directory), with a
file name corresponding to the local user name.")

  (kcm-mach-service
   (string/unset unset-field)
   "The name of the bootstrap service used to contact the KCM daemon for the
KCM credential cache type.")

  (kcm-socket
   (file-name unset-field)
 "Path to the Unix domain socket used to access the KCM daemon for the KCM
credential cache type.")

  (kdc-default-options
   (non-negative-integer/unset unset-field)
   "Default KDC options (logored for multiple values) when requesting initial
tickets.")

  (kdc-timesync
   (non-negative-integer/unset unset-field)
   "Attempt to compensate for clock skew between the KDC and client.")

  (kdc-req-checksum-type
   (non-negative-integer/unset unset-field)
   "The type of checksum to use for the KDC requests. Relevant only for DES
keys")

  (noaddresses?
   (boolean/unset unset-field)
   "If true, initial ticket requests will not be made with address restrictions.
This enables their use across NATs.")

  (permitted-enctypes
   (space-separated-string-list/unset unset-field)
   "All encryption types that are permitted for use in session key encryption.")

  (plugin-base-dir
   (file-name unset-field)
   "The directory where krb5 plugins are located.")

  (preferred-preauth-types
   (comma-separated-integer-list/unset unset-field)
   "The preferred pre-authentication types which the client will attempt before
others.")

  (proxiable?
   (boolean/unset unset-field)
   "Should initial tickets be proxiable by default?")

  (rdns?
   (boolean/unset unset-field)
   "Should reverse DNS lookup be used in addition to forward name lookup to
canonicalize host names for use in service principal names.")

  (realm-try-domains
   (integer/unset unset-field)
   "Should a host's domain components should be used to determine the Kerberos
realm of the host.")

  (renew-lifetime
   (non-negative-integer/unset unset-field)
   "The default renewable lifetime for initial ticket requests.")

  (safe-checksum-type
   (non-negative-integer/unset unset-field)
   "The type of checksum to use for the KRB-SAFE requests.")

  (ticket-lifetime
   (non-negative-integer/unset unset-field)
   "The default lifetime for initial ticket requests.")

  (udp-preference-limit
   (non-negative-integer/unset unset-field)
   "When sending messages to the KDC, the library will try using TCP
before UDP if the size of the message greater than this limit.")

  (verify-ap-rereq-nofail?
   (boolean/unset unset-field)
 "If true, then attempts to verify initial credentials will fail if the client
machine does not have a keytab.")

  (realms
   (realm-list '())
   "The list of realms which clients may access."))

(define (krb5-configuration-file config)
  "Create a Kerberos 5 configuration file based on CONFIG"
  (mixed-text-file "krb5.conf"
                   "[libdefaults]\n\n"
                   (with-output-to-string
                     (lambda ()
                       (serialize-configuration config
                                                krb5-configuration-fields)))))

(define (krb5-etc-service config)
  (list `("krb5.conf" ,(krb5-configuration-file config))))

(define krb5-service-type
  (service-type (name 'krb5)
                (extensions
                 (list (service-extension etc-service-type
                                          krb5-etc-service)))))

(define-record-type* <pam-krb5-configuration>
  pam-krb5-configuration  make-pam-krb5-configuration
  pam-krb5-configuration?
  (pam-krb5               pam-krb5-configuration-pam-krb5
                          (default pam-krb5))
  (minimum-uid            pam-krb5-configuration-minimum-uid
                          (default 1000)))

(define (pam-krb5-pam-service config)
  "Return a PAM service for Kerberos authentication."
  (lambda (pam)
    (define pam-krb5-module
      #~(string-append #$(pam-krb5-configuration-pam-krb5 config)
                       "/lib/security/pam_krb5.so"))

    (let ((pam-krb5-sufficient
           (pam-entry
            (control "sufficient")
            (module pam-krb5-module)
            (arguments
             (list
              (format #f "minimum_uid=~a"
                      (pam-krb5-configuration-minimum-uid config)))))))
      (pam-service
       (inherit pam)
       (auth (cons* pam-krb5-sufficient
                    (pam-service-auth pam)))
       (session (cons* pam-krb5-sufficient
                       (pam-service-session pam)))
       (account (cons* pam-krb5-sufficient
                       (pam-service-account pam)))))))

(define (pam-krb5-pam-services config)
  (list (pam-krb5-pam-service config)))

(define pam-krb5-service-type
  (service-type (name 'pam-krb5)
                (extensions
                 (list
                  (service-extension pam-root-service-type
                                     pam-krb5-pam-services)))))


code:
;;; GNU Guix --- Functional package management for GNU
;;; Copyright © 2020 Maxim Cournoyer <maxim.cournoyer@gmail.com>
;;; Copyright © 2020 Brice Waegeneire <brice@waegenei.re>
;;; Copyright © 2020 Efraim Flashner <efraim@flashner.co.il>
;;; Copyright © 2021 raid5atemyhomework <raid5atemyhomework@protonmail.com>
;;; Copyright © 2021 B. Wilson <elaexuotee@wilsonb.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 linux)
  #:use-module (guix gexp)
  #:use-module (guix records)
  #:use-module (guix modules)
  #:use-module (gnu services)
  #:use-module (gnu services base)
  #:use-module (gnu services shepherd)
  #:use-module (gnu packages linux)
  #:use-module (srfi srfi-1)
  #:use-module (srfi srfi-26)
  #:use-module (srfi srfi-34)
  #:use-module (srfi srfi-35)
  #:use-module (ice-9 match)
  #:export (earlyoom-configuration
            earlyoom-configuration?
            earlyoom-configuration-earlyoom
            earlyoom-configuration-minimum-available-memory
            earlyoom-configuration-minimum-free-swap
            earlyoom-configuration-prefer-regexp
            earlyoom-configuration-avoid-regexp
            earlyoom-configuration-memory-report-interval
            earlyoom-configuration-ignore-positive-oom-score-adj?
            earlyoom-configuration-show-debug-messages?
            earlyoom-configuration-send-notification-command
            earlyoom-service-type

            kernel-module-loader-service-type

            rasdaemon-configuration
            rasdaemon-configuration?
            rasdaemon-configuration-record?
            rasdaemon-service-type

            zram-device-configuration
            zram-device-configuration?
            zram-device-configuration-size
            zram-device-configuration-compression-algorithm
            zram-device-configuration-memory-limit
            zram-device-configuration-priority
            zram-device-service-type))

;;;
;;; Early OOM daemon.
;;;

(define-record-type* <earlyoom-configuration>
  earlyoom-configuration make-earlyoom-configuration
  earlyoom-configuration?
  (earlyoom earlyoom-configuration-earlyoom
            (default earlyoom))
  (minimum-available-memory earlyoom-configuration-minimum-available-memory
                            (default 10)) ; in percent
  (minimum-free-swap earlyoom-configuration-minimum-free-swap
                     (default 10))      ; in percent
  (prefer-regexp earlyoom-configuration-prefer-regexp ; <string>
                 (default #f))
  (avoid-regexp earlyoom-configuration-avoid-regexp  ; <string>
                (default #f))
  (memory-report-interval earlyoom-configuration-memory-report-interval
                          (default 0)) ; in seconds; 0 means disabled
  (ignore-positive-oom-score-adj?
   earlyoom-configuration-ignore-positive-oom-score-adj? (default #f))
  (run-with-higher-priority? earlyoom-configuration-run-with-higher-priority?
                             (default #f))
  (show-debug-messages? earlyoom-configuration-show-debug-messages?
                        (default #f))
  (send-notification-command
   earlyoom-configuration-send-notification-command  ; <string>
   (default #f)))

(define (earlyoom-configuration->command-line-args config)
  "Translate a <earlyoom-configuration> object to its command line arguments
representation."
  (match config
    (($ <earlyoom-configuration> earlyoom minimum-available-memory
                                 minimum-free-swap prefer-regexp avoid-regexp
                                 memory-report-interval
                                 ignore-positive-oom-score-adj?
                                 run-with-higher-priority? show-debug-messages?
                                 send-notification-command)
     `(,(file-append earlyoom "/bin/earlyoom")
       ,@(if minimum-available-memory
             (list "-m" (format #f "~s" minimum-available-memory))
             '())
       ,@(if minimum-free-swap
             (list "-s" (format #f "~s" minimum-free-swap))
             '())
       ,@(if prefer-regexp
             (list "--prefer" prefer-regexp)
             '())
       ,@(if avoid-regexp
             (list "--avoid" avoid-regexp)
             '())
       "-r" ,(format #f "~s" memory-report-interval)
       ,@(if ignore-positive-oom-score-adj?
             (list "-i")
             '())
       ,@(if run-with-higher-priority?
             (list "-p")
             '())
       ,@(if show-debug-messages?
             (list "-d")
             '())
       ,@(if send-notification-command
             (list "-N" send-notification-command)
             '())))))

(define (earlyoom-shepherd-service config)
  (shepherd-service
   (documentation "Run the Early OOM daemon.")
   (provision '(earlyoom))
   (start #~(make-forkexec-constructor
             '#$(earlyoom-configuration->command-line-args config)
             #:log-file "/var/log/earlyoom.log"))
   (stop #~(make-kill-destructor))))

(define earlyoom-service-type
  (service-type
   (name 'earlyoom)
   (default-value (earlyoom-configuration))
   (extensions
    (list (service-extension shepherd-root-service-type
                             (compose list earlyoom-shepherd-service))))
   (description "Run @command{earlyoom}, the Early OOM daemon.")))

;;;
;;; Kernel module loader.
;;;

(define kernel-module-loader-shepherd-service
  (match-lambda
    ((and (? list? kernel-modules) ((? string?) ...))
     (shepherd-service
      (documentation "Load kernel modules.")
      (provision '(kernel-module-loader))
      (requirement '())
      (one-shot? #t)
      (modules `((srfi srfi-1)
                 (srfi srfi-34)
                 (srfi srfi-35)
                 (rnrs io ports)
                 ,@%default-modules))
      (start
       #~(lambda _
           (cond
            ((null? '#$kernel-modules) #t)
            ((file-exists? "/proc/sys/kernel/modprobe")
             (let ((modprobe (call-with-input-file
                                 "/proc/sys/kernel/modprobe" get-line)))
               (guard (c ((message-condition? c)
                          (format (current-error-port) "~a~%"
                                  (condition-message c))
                          #f))
                 (every (lambda (module)
                          (invoke/quiet modprobe "--" module))
                        '#$kernel-modules))))
            (else
             (format (current-error-port) "error: ~a~%"
                     "Kernel is missing loadable module support.")
             #f))))))))

(define kernel-module-loader-service-type
  (service-type
   (name 'kernel-module-loader)
   (description "Load kernel modules.")
   (extensions
    (list (service-extension shepherd-root-service-type
                             (compose list kernel-module-loader-shepherd-service))))
   (compose concatenate)
   (extend append)
   (default-value '())))

;;;
;;; Reliability, Availability, and Serviceability (RAS) daemon
;;;

(define-record-type* <rasdaemon-configuration>
  rasdaemon-configuration make-rasdaemon-configuration
  rasdaemon-configuration?
  (record? rasdaemon-configuration-record? (default #f)))

(define (rasdaemon-configuration->command-line-args config)
  "Translate <rasdaemon-configuration> to its command line arguments
  representation"
  (let ((record? (rasdaemon-configuration-record? config)))
    `(,(file-append rasdaemon "/sbin/rasdaemon")
      "--foreground" ,@(if record? '("--record") '()))))

(define (rasdaemon-activation config)
  (let ((record? (rasdaemon-configuration-record? config))
        (rasdaemon-dir "/var/lib/rasdaemon"))
    (with-imported-modules '((guix build utils))
      #~(if #$record? (mkdir-p #$rasdaemon-dir)))))

(define (rasdaemon-shepherd-service config)
  (shepherd-service
   (documentation "Run rasdaemon")
   (provision '(rasdaemon))
   (requirement '(syslogd))
   (start #~(make-forkexec-constructor
             '#$(rasdaemon-configuration->command-line-args config)))
   (stop #~(make-kill-destructor))))

(define rasdaemon-service-type
  (service-type
   (name 'rasdaemon)
   (default-value (rasdaemon-configuration))
   (extensions
    (list (service-extension shepherd-root-service-type
                             (compose list rasdaemon-shepherd-service))
          (service-extension activation-service-type rasdaemon-activation)))
   (compose concatenate)
   (description "Run @command{rasdaemon}, the RAS monitor")))

;;;
;;; Kernel module loader.
;;;

(define-record-type* <zram-device-configuration>
  zram-device-configuration make-zram-device-configuration
  zram-device-configuration?
  (size                     zram-device-configuration-size
                            (default "1G"))     ; string or integer
  (compression-algorithm    zram-device-configuration-compression-algorithm
                            (default 'lzo))     ; symbol
  (memory-limit             zram-device-configuration-memory-limit
                            (default 0))        ; string or integer
  (priority                 zram-device-configuration-priority
                            (default -1)))      ; integer

(define (zram-device-configuration->udev-string config)
  "Translate a <zram-device-configuration> into a string which can be
placed in a udev rules file."
  (match config
    (($ <zram-device-configuration> size compression-algorithm memory-limit priority)
     (string-append
       "KERNEL==\"zram0\", "
       "ATTR{comp_algorithm}=\"" (symbol->string compression-algorithm) "\" "
       (if (not (or (equal? "0" size)
                    (equal? 0 size)))
         (string-append "ATTR{disksize}=\"" (if (number? size)
                                              (number->string size)
                                              size)
                        "\" ")
         "")
       (if (not (or (equal? "0" memory-limit)
                    (equal? 0 memory-limit)))
         (string-append "ATTR{mem_limit}=\"" (if (number? memory-limit)
                                               (number->string memory-limit)
                                               memory-limit)
                        "\" ")
         "")
       "RUN+=\"/run/current-system/profile/sbin/mkswap /dev/zram0\" "
       "RUN+=\"/run/current-system/profile/sbin/swapon "
       (if (not (equal? -1 priority))
         (string-append "--priority " (number->string priority) " ")
         "")
       "/dev/zram0\"\n"))))

(define %zram-device-config
  `("modprobe.d/zram.conf"
    ,(plain-file "zram.conf"
                 "options zram num_devices=1")))

(define (zram-device-udev-rule config)
  (file->udev-rule "99-zram.rules"
                   (plain-file "99-zram.rules"
                               (zram-device-configuration->udev-string config))))

(define zram-device-service-type
  (service-type
    (name 'zram)
    (default-value (zram-device-configuration))
    (extensions
      (list (service-extension kernel-module-loader-service-type
                               (const (list "zram")))
            (service-extension etc-service-type
                               (const (list %zram-device-config)))
            (service-extension udev-service-type
                               (compose list zram-device-udev-rule))))
    (description "Creates a zram swap device.")))


code:
;;; GNU Guix --- Functional package management for GNU
;;; Copyright © 2015 Alex Kost <alezost@gmail.com>
;;; Copyright © 2015, 2016 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 lirc)
  #:use-module (gnu services)
  #:use-module (gnu services shepherd)
  #:use-module (gnu packages lirc)
  #:use-module (guix gexp)
  #:use-module (guix records)
  #:use-module (ice-9 match)
  #:export (lirc-configuration
            lirc-configuation?
            lirc-service
            lirc-service-type))

;;; Commentary:
;;;
;;; LIRC service.
;;;
;;; Code:

(define-record-type* <lirc-configuration>
  lirc-configuration make-lirc-configuration
  lirc-configuation?
  (lirc          lirc-configuration-lirc          ;<package>
                 (default lirc))
  (device        lirc-configuration-device)       ;string
  (driver        lirc-configuration-driver)       ;string
  (config-file   lirc-configuration-file)         ;string | file-like object
  (extra-options lirc-configuration-options       ;list of strings
                 (default '())))

(define %lirc-activation
  #~(begin
      (use-modules (guix build utils))
      (mkdir-p "/var/run/lirc")))

(define lirc-shepherd-service
  (match-lambda
    (($ <lirc-configuration> lirc device driver config-file options)
     (list (shepherd-service
            (provision '(lircd))
            (documentation "Run the LIRC daemon.")
            (requirement '(user-processes))
            (start #~(make-forkexec-constructor
                      (list (string-append #$lirc "/sbin/lircd")
                            "--nodaemon"
                            #$@(if device
                                   #~("--device" #$device)
                                   #~())
                            #$@(if driver
                                   #~("--driver" #$driver)
                                   #~())
                            #$@(if config-file
                                   #~(#$config-file)
                                   #~())
                            #$@options)))
            (stop #~(make-kill-destructor)))))))

(define lirc-service-type
  (service-type (name 'lirc)
                (extensions
                 (list (service-extension shepherd-root-service-type
                                          lirc-shepherd-service)
                       (service-extension activation-service-type
                                          (const %lirc-activation))))))

(define* (lirc-service #:key (lirc lirc)
                       device driver config-file
                       (extra-options '()))
  "Return a service that runs @url{http://www.lirc.org,LIRC}, a daemon that
decodes infrared signals from remote controls.

The daemon will use specified @var{device}, @var{driver} and
@var{config-file} (configuration file name).

Finally, @var{extra-options} is a list of additional command-line options
passed to @command{lircd}."
  (service lirc-service-type
           (lirc-configuration
            (lirc lirc)
            (device device) (driver driver)
            (config-file config-file)
            (extra-options extra-options))))

;;; lirc.scm ends here