;;; GNU Guix --- Functional package management for GNU ;;; Copyright © 2018, 2020 Mathieu Othacehe ;;; Copyright © 2019, 2020 Ludovic Courtès ;;; ;;; 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 . (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 build install) #:use-module (gnu build linux-container) #:use-module ((gnu system shadow) #:prefix sys:) #:use-module (rnrs io ports) #:use-module (srfi srfi-1) #:use-module (ice-9 ftw) #:use-module (ice-9 popen) #:use-module (ice-9 match) #:use-module (ice-9 format) #:use-module (ice-9 rdelim) #: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* (kill-cow-users cow-path #:key (spare '("udevd"))) "Kill all processes that have references to the given COW-PATH in their 'maps' file. The process whose names are in SPARE list are spared." (define %not-nul (char-set-complement (char-set #\nul))) (let ((pids (filter-map (lambda (pid) (false-if-exception (call-with-input-file (string-append "/proc/" pid "/maps") (lambda (port) (and (string-contains (get-string-all port) cow-path) (string->number pid)))))) (scandir "/proc" string->number)))) (for-each (lambda (pid) ;; cmdline does not always exist. (false-if-exception (call-with-input-file (string-append "/proc/" (number->string pid) "/cmdline") (lambda (port) (match (string-tokenize (read-string port) %not-nul) ((argv0 _ ...) (unless (member (basename argv0) spare) (syslog "Killing process ~a (~a)~%" pid argv0) (kill pid SIGKILL))) (_ #f)))))) pids))) (define (call-with-mnt-container thunk) "This is a variant of call-with-container. Run THUNK in a new container process, within a separate MNT namespace. The container is not jailed so that it can interact with the rest of the system." (let ((pid (run-container "/" '() '(mnt) 1 thunk))) ;; Catch SIGINT and kill the container process. (sigaction SIGINT (lambda (signum) (false-if-exception (kill pid SIGKILL)))) (match (waitpid pid) ((_ . status) status)))) (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." (define backing-directory ;; Sub-directory used as the backing store for copy-on-write. "/tmp/guix-inst") (define (assert-exit x) (primitive-exit (if x 0 1))) (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)))) (database-dir "/var/guix/db") (database-file (string-append database-dir "/db.sqlite")) (saved-database (string-append database-dir "/db.save")) (ret #f)) (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)) ;; When the store overlay is mounted, other processes such as kmscon, udev ;; and guix-daemon may open files from the store, preventing the ;; underlying install support from being umounted. See: ;; https://lists.gnu.org/archive/html/guix-devel/2018-12/msg00161.html. ;; ;; To avoid this situation, mount the store overlay inside a container, ;; and run the installation from within that container. (zero? (call-with-mnt-container (lambda () (dynamic-wind (lambda () ;; Save the database, so that it can be restored once the ;; cow-store is umounted. (copy-file database-file saved-database) (mount-cow-store (%installer-target-dir) backing-directory)) (lambda () ;; We need to drag the guix-daemon to the container MNT ;; namespace, so that it can operate on the cow-store. (stop-service 'guix-daemon) (start-service 'guix-daemon (list (number->string (getpid)))) (setvbuf (current-output-port) 'none) (setvbuf (current-error-port) 'none) ;; If there are any connected clients, assume that we are running ;; installation tests. In that case, dump the standard and error ;; outputs to syslog. (set! ret (if (not (null? (current-clients))) (with-output-to-file "/dev/console" (lambda () (with-error-to-file "/dev/console" (lambda () (run-command install-command #:locale locale))))) (run-command install-command #:locale locale)))) (lambda () ;; Restart guix-daemon so that it does no keep the MNT namespace ;; alive. (restart-service 'guix-daemon) (copy-file saved-database database-file) ;; Finally umount the cow-store and exit the container. (unmount-cow-store (%installer-target-dir) backing-directory) (assert-exit ret))))))))