aboutsummaryrefslogtreecommitdiff
path: root/gnu/installer/final.scm
blob: 869be8814be869cc74d1ce08aa46d437cdd38adf (about) (plain)
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
;;; GNU Guix --- Functional package management for GNU
;;; Copyright © 2018, 2020 Mathieu Othacehe <m.othacehe@gmail.com>
;;; Copyright © 2019, 2020 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 installer final)
  #:use-module (gnu installer newt page)
  #:use-module (gnu installer steps)
  #:use-module (gnu installer utils)
  #:use-module (gnu installer user)
  #:use-module (gnu services herd)
  #:use-module (guix build syscalls)
  #:use-module (guix build utils)
  #:use-module (gnu build accounts)
  #:use-module ((gnu system shadow) #:prefix sys:)
  #:use-module (rnrs io ports)
  #:export (install-system))

(define %seed
  (seed->random-state
   (logxor (getpid) (car (gettimeofday)))))

(define (integer->alphanumeric-char n)
  "Map N, an integer in the [0..62] range, to an alphanumeric character."
  (cond ((< n 10)
         (integer->char (+ (char->integer #\0) n)))
        ((< n 36)
         (integer->char (+ (char->integer #\A) (- n 10))))
        ((< n 62)
         (integer->char (+ (char->integer #\a) (- n 36))))
        (else
         (error "integer out of bounds" n))))

(define (random-string len)
  "Compute a random string of size LEN where each character is alphanumeric."
  (let loop ((chars '())
             (len len))
    (if (zero? len)
        (list->string chars)
        (let ((n (random 62 %seed)))
          (loop (cons (integer->alphanumeric-char n) chars)
                (- len 1))))))

(define (create-user-database users root)
  "Create /etc/passwd, /etc/shadow, and /etc/group under ROOT for the given
USERS."
  (define etc
    (string-append root "/etc"))

  (define (salt)
    ;; "$6" gives us a SHA512 password hash; the random string must be taken
    ;; from the './0-9A-Za-z' alphabet (info "(libc) Passphrase Storage").
    (string-append "$6$" (random-string 10)))

  (define users*
    (map (lambda (user)
           (define root?
             (string=? "root" (user-name user)))

           (sys:user-account (name (user-name user))
                             (comment (user-real-name user))
                             (group "users")
                             (uid (if root? 0 #f))
                             (home-directory
                              (user-home-directory user))
                             (password (crypt (user-password user)
                                              (salt)))

                             ;; We need a string here, not a file-like, hence
                             ;; this choice.
                             (shell
                              "/run/current-system/profile/bin/bash")))
         users))

  (define-values (group password shadow)
    (user+group-databases users* sys:%base-groups
                          #:current-passwd '()
                          #:current-groups '()
                          #:current-shadow '()))

  (mkdir-p etc)
  (write-group group (string-append etc "/group"))
  (write-passwd password (string-append etc "/passwd"))
  (write-shadow shadow (string-append etc "/shadow")))

(define (umount-cow-store)
  "Remove the store overlay and the bind-mount on /tmp created by the
cow-store service."
  (let ((tmp-dir "/remove"))
    (mkdir-p tmp-dir)
    (mount (%store-directory) tmp-dir "" MS_MOVE)
    (umount tmp-dir)
    (umount "/tmp")))

(define* (install-system locale #:key (users '()))
  "Create /etc/shadow and /etc/passwd on the installation target for USERS.
Start COW-STORE service on target directory and launch guix install command in
a subshell.  LOCALE must be the locale name under which that command will run,
or #f.  Return #t on success and #f on failure."
  (let* ((options         (catch 'system-error
                            (lambda ()
                              ;; If this file exists, it can provide
                              ;; additional command-line options.
                              (call-with-input-file
                                  "/tmp/installer-system-init-options"
                                read))
                            (const '())))
         (install-command (append (list "guix" "system" "init"
                                        "--fallback")
                                  options
                                  (list (%installer-configuration-file)
                                        (%installer-target-dir)))))
    (mkdir-p (%installer-target-dir))

    ;; We want to initialize user passwords but we don't want to store them in
    ;; the config file since the password hashes would end up world-readable
    ;; in the store.  Thus, create /etc/shadow & co. here such that, on the
    ;; first boot, the activation snippet that creates accounts will reuse the
    ;; passwords that we've put in there.
    (create-user-database users (%installer-target-dir))

    (dynamic-wind
      (lambda ()
        (start-service 'cow-store (list (%installer-target-dir))))
      (lambda ()
        (run-command install-command #:locale locale))
      (lambda ()
        (stop-service 'cow-store)
        ;; Remove the store overlay created at cow-store service start.
        ;; Failing to do that will result in further umount calls to fail
        ;; because the target device is seen as busy. See:
        ;; https://lists.gnu.org/archive/html/guix-devel/2018-12/msg00161.html.
        (umount-cow-store)
        #f))))