me
/
guix
Archived
1
0
Fork 0
This repository has been archived on 2024-08-07. You can view files and clone it, but cannot push or open issues/pull-requests.
guix/gnu/system/linux.scm

216 lines
7.8 KiB
Scheme
Raw Blame History

This file contains invisible Unicode characters!

This file contains invisible Unicode characters that may be processed differently from what appears below. If your use case is intentional and legitimate, you can safely ignore this warning. Use the Escape button to reveal hidden characters.

;;; GNU Guix --- Functional package management for GNU
;;; Copyright © 2013, 2014, 2015 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 linux)
#:use-module (guix records)
#:use-module (guix derivations)
#:use-module (guix gexp)
#:use-module (gnu services)
#:use-module (ice-9 match)
#:use-module (srfi srfi-1)
#:use-module (srfi srfi-26)
#:use-module ((guix utils) #:select (%current-system))
#:export (pam-service
pam-entry
pam-services->directory
unix-pam-service
base-pam-services
pam-root-service-type
pam-root-service))
;;; Commentary:
;;;
;;; Configuration of Linux-related things, including pluggable authentication
;;; modules (PAM).
;;;
;;; Code:
;; PAM services (see
;; <http://www.linux-pam.org/Linux-PAM-html/sag-configuration-file.html>.)
(define-record-type* <pam-service> pam-service
make-pam-service
pam-service?
(name pam-service-name) ; string
;; The four "management groups".
(account pam-service-account ; list of <pam-entry>
(default '()))
(auth pam-service-auth
(default '()))
(password pam-service-password
(default '()))
(session pam-service-session
(default '())))
(define-record-type* <pam-entry> pam-entry
make-pam-entry
pam-entry?
(control pam-entry-control) ; string
(module pam-entry-module) ; file name
(arguments pam-entry-arguments ; list of string-valued g-expressions
(default '())))
(define (pam-service->configuration service)
"Return the derivation building the configuration file for SERVICE, to be
dumped in /etc/pam.d/NAME, where NAME is the name of SERVICE."
(define (entry->gexp type entry)
(match entry
(($ <pam-entry> control module (arguments ...))
#~(format #t "~a ~a ~a ~a~%"
#$type #$control #$module
(string-join (list #$@arguments))))))
(match service
(($ <pam-service> name account auth password session)
(define builder
#~(begin
(with-output-to-file #$output
(lambda ()
#$@(append (map (cut entry->gexp "account" <>) account)
(map (cut entry->gexp "auth" <>) auth)
(map (cut entry->gexp "password" <>) password)
(map (cut entry->gexp "session" <>) session))
#t))))
(computed-file name builder))))
(define (pam-services->directory services)
"Return the derivation to build the configuration directory to be used as
/etc/pam.d for SERVICES."
(let ((names (map pam-service-name services))
(files (map pam-service->configuration services)))
(define builder
#~(begin
(use-modules (ice-9 match)
(srfi srfi-1))
(mkdir #$output)
(for-each (match-lambda
((name file)
(symlink file (string-append #$output "/" name))))
;; Since <pam-service> objects cannot be compared with
;; 'equal?' since they contain gexps, which contain
;; closures, use 'delete-duplicates' on the build-side
;; instead. See <http://bugs.gnu.org/20037>.
(delete-duplicates '#$(zip names files)))))
(computed-file "pam.d" builder)))
(define %pam-other-services
;; The "other" PAM configuration, which denies everything (see
;; <http://www.linux-pam.org/Linux-PAM-html/sag-configuration-example.html>.)
(let ((deny (pam-entry
(control "required")
(module "pam_deny.so"))))
(pam-service
(name "other")
(account (list deny))
(auth (list deny))
(password (list deny))
(session (list deny)))))
(define unix-pam-service
(let ((unix (pam-entry
(control "required")
(module "pam_unix.so"))))
(lambda* (name #:key allow-empty-passwords? motd)
"Return a standard Unix-style PAM service for NAME. When
ALLOW-EMPTY-PASSWORDS? is true, allow empty passwords. When MOTD is true, it
should be a file-like object used as the message-of-the-day."
;; See <http://www.linux-pam.org/Linux-PAM-html/sag-configuration-example.html>.
(let ((name* name))
(pam-service
(name name*)
(account (list unix))
(auth (list (if allow-empty-passwords?
(pam-entry
(control "required")
(module "pam_unix.so")
(arguments '("nullok")))
unix)))
(password (list (pam-entry
(control "required")
(module "pam_unix.so")
;; Store SHA-512 encrypted passwords in /etc/shadow.
(arguments '("sha512" "shadow")))))
(session (if motd
(list unix
(pam-entry
(control "optional")
(module "pam_motd.so")
(arguments
(list #~(string-append "motd=" #$motd)))))
(list unix))))))))
(define (rootok-pam-service command)
"Return a PAM service for COMMAND such that 'root' does not need to
authenticate to run COMMAND."
(let ((unix (pam-entry
(control "required")
(module "pam_unix.so"))))
(pam-service
(name command)
(account (list unix))
(auth (list (pam-entry
(control "sufficient")
(module "pam_rootok.so"))))
(password (list unix))
(session (list unix)))))
(define* (base-pam-services #:key allow-empty-passwords?)
"Return the list of basic PAM services everyone would want."
;; TODO: Add other Shadow programs?
(append (list %pam-other-services)
;; These programs are setuid-root.
(map (cut unix-pam-service <>
#:allow-empty-passwords? allow-empty-passwords?)
'("su" "passwd" "sudo"
"xlock" "xscreensaver"))
;; These programs are not setuid-root, and we want root to be able
;; to run them without having to authenticate (notably because
;; 'useradd' and 'groupadd' are run during system activation.)
(map rootok-pam-service
'("useradd" "userdel" "usermod"
"groupadd" "groupdel" "groupmod"))))
;;;
;;; PAM root service.
;;;
(define (/etc-entry services)
`(("pam.d" ,(pam-services->directory services))))
(define pam-root-service-type
(service-type (name 'pam)
(extensions (list (service-extension etc-service-type
/etc-entry)))
(compose concatenate)
(extend append)))
(define (pam-root-service base)
"The \"root\" PAM service, which collects <pam-service> instance and turns
them into a /etc/pam.d directory, including the <pam-service> listed in BASE."
(service pam-root-service-type base))
;;; linux.scm ends here