1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
|
;;; GNU Guix --- Functional package management for GNU
;;; Copyright © 2013, 2014 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 (guix build activation)
#:use-module (guix build utils)
#:use-module (guix build linux-initrd)
#:use-module (ice-9 ftw)
#:use-module (ice-9 match)
#:use-module (srfi srfi-1)
#:use-module (srfi srfi-26)
#:export (activate-users+groups
activate-etc
activate-setuid-programs
activate-current-system))
;;; Commentary:
;;;
;;; This module provides "activation" helpers. Activation is the process that
;;; consists in setting up system-wide files and directories so that an
;;; 'operating-system' configuration becomes active.
;;;
;;; Code:
(define* (add-group name #:key gid password system?
(log-port (current-error-port)))
"Add NAME as a user group, with the given numeric GID if specified."
;; Use 'groupadd' from the Shadow package.
(format log-port "adding group '~a'...~%" name)
(let ((args `(,@(if gid `("-g" ,(number->string gid)) '())
,@(if password `("-p" ,password) '())
,@(if system? `("--system") '())
,name)))
(zero? (apply system* "groupadd" args))))
(define* (add-user name group
#:key uid comment home shell password system?
(supplementary-groups '())
(log-port (current-error-port)))
"Create an account for user NAME part of GROUP, with the specified
properties. Return #t on success."
(format log-port "adding user '~a'...~%" name)
(if (and uid (zero? uid))
;; 'useradd' fails with "Cannot determine your user name" if the root
;; account doesn't exist. Thus, for bootstrapping purposes, create that
;; one manually.
(begin
(call-with-output-file "/etc/shadow"
(cut format <> "~a::::::::~%" name))
(call-with-output-file "/etc/passwd"
(cut format <> "~a:x:~a:~a:~a:~a:~a~%"
name "0" "0" comment home shell))
(chmod "/etc/shadow" #o600)
#t)
;; Use 'useradd' from the Shadow package.
(let ((args `(,@(if uid `("-u" ,(number->string uid)) '())
"-g" ,(if (number? group) (number->string group) group)
,@(if (pair? supplementary-groups)
`("-G" ,(string-join supplementary-groups ","))
'())
,@(if comment `("-c" ,comment) '())
,@(if home
(if (file-exists? home)
`("-d" ,home) ; avoid warning from 'useradd'
`("-d" ,home "--create-home"))
'())
,@(if shell `("-s" ,shell) '())
,@(if password `("-p" ,password) '())
,@(if system? '("--system") '())
,name)))
(zero? (apply system* "useradd" args)))))
(define (activate-users+groups users groups)
"Make sure the accounts listed in USERS and the user groups listed in GROUPS
are all available.
Each item in USERS is a list of all the characteristics of a user account;
each item in GROUPS is a tuple with the group name, group password or #f, and
numeric gid or #f."
(define (touch file)
(close-port (open-file file "a0b")))
(define activate-user
(match-lambda
((name uid group supplementary-groups comment home shell password system?)
(unless (false-if-exception (getpwnam name))
(let ((profile-dir (string-append "/var/guix/profiles/per-user/"
name)))
(add-user name group
#:uid uid
#:system? system?
#:supplementary-groups supplementary-groups
#:comment comment
#:home home
#:shell shell
#:password password)
(unless system?
;; Create the profile directory for the new account.
(let ((pw (getpwnam name)))
(mkdir-p profile-dir)
(chown profile-dir (passwd:uid pw) (passwd:gid pw)))))))))
;; 'groupadd' aborts if the file doesn't already exist.
(touch "/etc/group")
;; Create the root account so we can use 'useradd' and 'groupadd'.
(activate-user (find (match-lambda
((name (? zero?) _ ...) #t)
(_ #f))
users))
;; Then create the groups.
(for-each (match-lambda
((name password gid system?)
(unless (false-if-exception (getgrnam name))
(add-group name
#:gid gid #:password password
#:system? system?))))
groups)
;; Finally create the other user accounts.
(for-each activate-user users))
(define (activate-etc etc)
"Install ETC, a directory in the store, as the source of static files for
/etc."
;; /etc is a mixture of static and dynamic settings. Here is where we
;; initialize it from the static part.
(format #t "populating /etc from ~a...~%" etc)
(let ((rm-f (lambda (f)
(false-if-exception (delete-file f)))))
(rm-f "/etc/static")
(symlink etc "/etc/static")
(for-each (lambda (file)
;; TODO: Handle 'shadow' specially so that changed
;; password aren't lost.
(let ((target (string-append "/etc/" file))
(source (string-append "/etc/static/" file)))
(rm-f target)
(symlink source target)))
(scandir etc
(lambda (file)
(not (member file '("." ".."))))
;; The default is 'string-locale<?', but we don't have
;; it when run from the initrd's statically-linked
;; Guile.
string<?))
;; Prevent ETC from being GC'd.
(rm-f "/var/guix/gcroots/etc-directory")
(symlink etc "/var/guix/gcroots/etc-directory")))
(define %setuid-directory
;; Place where setuid programs are stored.
"/run/setuid-programs")
(define (activate-setuid-programs programs)
"Turn PROGRAMS, a list of file names, into setuid programs stored under
%SETUID-DIRECTORY."
(define (make-setuid-program prog)
(let ((target (string-append %setuid-directory
"/" (basename prog))))
(catch 'system-error
(lambda ()
(link prog target))
(lambda args
;; Perhaps PROG and TARGET live in a different file system, so copy
;; PROG.
(copy-file prog target)))
(chown target 0 0)
(chmod target #o6555)))
(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))
(for-each make-setuid-program programs))
(define %current-system
;; The system that is current (a symlink.) This is not necessarily the same
;; as the system we booted (aka. /run/booted-system) because we can re-build
;; a new system configuration and activate it, without rebooting.
"/run/current-system")
(define (boot-time-system)
"Return the '--system' argument passed on the kernel command line."
(find-long-option "--system" (linux-command-line)))
(define* (activate-current-system #:optional (system (boot-time-system)))
"Atomically make SYSTEM the current system."
(format #t "making '~a' the current system...~%" system)
;; Atomically make SYSTEM current.
(let ((new (string-append %current-system ".new")))
(symlink system new)
(rename-file new %current-system)))
;;; activation.scm ends here
|