~ruther/guix-local

d6c9754c568588929c3350da8f7b17ae92d2b801 — Tobias Geerinckx-Rice 3 years ago 0dffb85
services: setuid-program: Populate /run/privileged/bin.

Create /run/setuid-programs compatibility symlinks so that we can
migrate all users (both package and human) piecemeal at our leisure.

Apart from being symlinks, this should be a user-invisible change.

* gnu/build/activation.scm (%privileged-program-directory): New variable.
[activate-setuid-programs]: Put privileged copies in
%PRIVILEGED-PROGRAM-DIRECTORY, with compatibility symlinks to each in
%SETUID-DIRECTORY.
* gnu/services.scm (setuid-program-service-type): Update docstring.
* doc/guix.texi (Setuid Programs): Update @file{} name accordingly.
3 files changed, 44 insertions(+), 21 deletions(-)

M doc/guix.texi
M gnu/build/activation.scm
M gnu/services.scm
M doc/guix.texi => doc/guix.texi +1 -1
@@ 41732,7 41732,7 @@ The list includes commands such as @command{passwd}, @command{ping},
@end defvar

Under the hood, the actual setuid programs are created in the
@file{/run/setuid-programs} directory at system activation time.  The
@file{/run/privileged/bin} directory at system activation time.  The
files in this directory refer to the ``real'' binaries, which are in the
store.


M gnu/build/activation.scm => gnu/build/activation.scm +36 -18
@@ 8,6 8,7 @@
;;; Copyright © 2021 Maxime Devos <maximedevos@telenet.be>
;;; Copyright © 2020 Christine Lemmer-Webber <cwebber@dustycloud.org>
;;; Copyright © 2021 Brice Waegeneire <brice@waegenei.re>
;;; Copyright © 2022 Tobias Geerinckx-Rice <me@tobias.gr>
;;; Copyright © 2024 Nicolas Graves <ngraves@ngraves.fr>
;;;
;;; This file is part of GNU Guix.


@@ 279,14 280,29 @@ they already exist."
                     string<?)))

(define %setuid-directory
  ;; Place where setuid programs are stored.
  ;; Place where setuid programs used to be stored.  It exists for backwards
  ;; compatibility & will be removed.  Use %PRIVILEGED-PROGRAM-DIRECTORY instead.
  "/run/setuid-programs")

(define %privileged-program-directory
  ;; Place where privileged copies of programs are stored.
  "/run/privileged/bin")

(define (activate-setuid-programs programs)
  "Turn PROGRAMS, a list of file setuid-programs record, into setuid programs
stored under %SETUID-DIRECTORY."
  (define (make-setuid-program program setuid? setgid? uid gid)
    (let ((target (string-append %setuid-directory
  "Turn PROGRAMS, a list of file setuid-programs records, into privileged
copies stored under %PRIVILEGED-PROGRAM-DIRECTORY."
  (define (ensure-empty-directory directory)
    (if (file-exists? directory)
        (for-each (compose delete-file
                           (cut string-append directory "/" <>))
                  (scandir directory
                           (lambda (file)
                             (not (member file '("." ".."))))
                           string<?))
        (mkdir-p directory))    )

  (define (make-privileged-program program setuid? setgid? uid gid)
    (let ((target (string-append %privileged-program-directory
                                 "/" (basename program)))
          (mode (+ #o0555                   ; base permissions
                   (if setuid? #o4000 0)    ; setuid bit


@@ 295,16 311,17 @@ stored under %SETUID-DIRECTORY."
      (chown target uid gid)
      (chmod target mode)))

  (format #t "setting up setuid programs in '~a'...~%"
          %setuid-directory)
  (if (file-exists? %setuid-directory)
      (for-each (compose delete-file
                         (cut string-append %setuid-directory "/" <>))
                (scandir %setuid-directory
                         (lambda (file)
                           (not (member file '("." ".."))))
                         string<?))
      (mkdir-p %setuid-directory))
  (define (make-deprecated-wrapper program)
    ;; This will eventually become a script that warns on usage, then vanish.
    (symlink (string-append %privileged-program-directory
                            "/" (basename program))
             (string-append %setuid-directory
                            "/" (basename program))))

  (format #t "setting up privileged programs in '~a'...~%"
          %privileged-program-directory)
  (ensure-empty-directory %privileged-program-directory)
  (ensure-empty-directory %setuid-directory)

  (for-each (lambda (program)
              (catch 'system-error


@@ 320,11 337,12 @@ stored under %SETUID-DIRECTORY."
                         (gid (match group
                                ((? string?) (group:gid (getgrnam group)))
                                ((? integer?) group))))
                    (make-setuid-program program-name setuid? setgid? uid gid)))
                    (make-privileged-program program-name setuid? setgid? uid gid)
                    (make-deprecated-wrapper program-name)))
                (lambda args
                  ;; If we fail to create a setuid program, better keep going
                  ;; so that we don't leave %SETUID-DIRECTORY empty or
                  ;; half-populated.  This can happen if PROGRAMS contains
                  ;; so that we don't leave %PRIVILEGED-PROGRAM-DIRECTORY empty
                  ;; or half-populated.  This can happen if PROGRAMS contains
                  ;; incorrect file names: <https://bugs.gnu.org/38800>.
                  (format (current-error-port)
                          "warning: failed to make ~s setuid/setgid: ~a~%"

M gnu/services.scm => gnu/services.scm +7 -2
@@ 6,6 6,7 @@
;;; Copyright © 2021 raid5atemyhomework <raid5atemyhomework@protonmail.com>
;;; Copyright © 2020 Christine Lemmer-Webber <cwebber@dustycloud.org>
;;; Copyright © 2020, 2021 Brice Waegeneire <brice@waegenei.re>
;;; Copyright © 2022 Tobias Geerinckx-Rice <me@tobias.gr>
;;; Copyright © 2023 Brian Cully <bjc@spork.org>
;;; Copyright © 2024 Nicolas Graves <ngraves@ngraves.fr>
;;;


@@ 921,8 922,12 @@ FILES must be a list of name/file-like object pairs."
                (extend (lambda (config extensions)
                          (append config extensions)))
                (description
                 "Populate @file{/run/setuid-programs} with the specified
executables, making them setuid and/or setgid.")))
                 "Copy the specified executables to @file{/run/privileged/bin}
and apply special privileges like setuid and/or setgid.

The deprecated @file{/run/setuid-programs} directory is also populated with
symbolic links to their @file{/run/privileged/bin} counterpart.  It will be
removed in a future Guix release.")))

(define (packages->profile-entry packages)
  "Return a system entry for the profile containing PACKAGES."