@@ -321,6 +321,7 @@ System Configuration
* Invoking guix deploy:: Deploying a system configuration to a remote host.
* Running Guix in a VM:: How to run Guix System in a virtual machine.
* Defining Services:: Adding new service definitions.
+* Activation:: Setting up system-wide files and directories.
Services
@@ -13386,6 +13387,7 @@ instance to support new system services.
* Invoking guix deploy:: Deploying a system configuration to a remote host.
* Running Guix in a VM:: How to run Guix System in a virtual machine.
* Defining Services:: Adding new service definitions.
+* Activation:: Setting up system-wide files and directories.
@end menu
@node Using the Configuration System
@@ -34633,6 +34635,35 @@ system:
This service represents PID@tie{}1.
@end defvr
+@node Activation
+@section Activation
+
+@dfn{Activation} is the process that sets up system-wide files and
+directories so that an @code{operating-system} (@pxref{operating-system
+Reference}) configuration becomes active. This will happen when
+invoking commands like @command{guix system reconfigure} or
+@command{guix system switch-generation}, but not when invoking
+@command{guix system build} (@pxref{Invoking guix system}).
+
+@deffn {Scheme Procedure} call-with-output-file* @var{file} @var{proc} @
+ [#:perms #o666]
+Open FILE for output, set the file permission bits to @var{perms}, and
+call @code{(PROC port)} with the resulting port.
+
+The advantage of using this procedure compared to something like this
+
+@lisp
+(call-with-output-file "FILE"
+ (lambda (port)
+ (display "top secret" port)))
+(chmod "FILE" #o400)
+@end lisp
+
+is that, with the latter, an unpriviliged user could open @var{file}
+before the permission was changed to @code{#o400}, thus making it
+possible to leak sensitive information.
+@end deffn
+
@node Documentation
@chapter Documentation
@@ -6,6 +6,7 @@
;;; Copyright © 2018 Arun Isaac <arunisaac@systemreboot.net>
;;; Copyright © 2018, 2019 Ricardo Wurmus <rekado@elephly.net>
;;; Copyright © 2021 Maxime Devos <maximedevos@telenet.be>
+;;; Copyright © 2021 Xinglu Chen <public@yoctocell.xyz>
;;;
;;; This file is part of GNU Guix.
;;;
@@ -34,6 +35,7 @@
#:use-module (srfi srfi-1)
#:use-module (srfi srfi-11)
#:use-module (srfi srfi-26)
+ #:use-module (srfi srfi-60)
#:export (activate-users+groups
activate-user-home
activate-etc
@@ -43,7 +45,8 @@
activate-firmware
activate-ptrace-attach
activate-current-system
- mkdir-p/perms))
+ mkdir-p/perms
+ call-with-output-file*))
;;; Commentary:
;;;
@@ -102,6 +105,14 @@ Warning: this is currently suspect to a TOCTTOU race!"
(chown directory (passwd:uid owner) (passwd:gid owner))
(chmod directory bits))
+;; Prevent secrets from leaking, see <https://issues.guix.gnu.org/48872>
+(define* (call-with-output-file* file proc #:key (perms #o666))
+ "FILE should be string containg the path to a file, PROC should be a procedure
+that accepts the port as an argument, and PERMS should be the permission bits
+of the file, the default is 666."
+ (let ((port (open file (bitwise-ior O_WRONLY O_CREAT) perms)))
+ (call-with-port port proc)))
+
(define* (copy-account-skeletons home
#:key
(directory %skeleton-directory)