;;; 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) #: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 (pk (basename argv0)) spare) (syslog "Killing process ~a~%" pid) (kill pid SIGKILL))) (_ #f)))))) pids))) (define (umount-cow-store) "Remove the store overlay and the bind-mount on /tmp created by the cow-store service. This procedure is very fragile and a better approach would be much appreciated." ;; Remove when integrated in (gnu services herd). (define (restart-service name) (with-shepherd-action name ('restart) result result)) (catch #t (lambda () (let ((tmp-dir "/remove")) (mkdir-p tmp-dir) (mount (%store-directory) tmp-dir "" MS_MOVE) ;; The guix-daemon has possibly opened files from the cow-store, ;; restart it. (restart-service 'guix-daemon) ;; Kill all processes started while the cow-store was active (logins ;; on other TTYs for instance). (kill-cow-users tmp-dir) ;; Try to umount the store overlay. Some process such as udevd ;; workers might still be active, so do some retries. (let loop ((try 5)) (sleep 1) (let ((umounted? (false-if-exception (umount tmp-dir)))) (if (and (not umounted?) (> try 0)) (loop (- try 1)) (if umounted? (syslog "Umounted ~a successfully.~%" tmp-dir) (syslog "Failed to umount ~a.~%" tmp-dir))))) (umount "/tmp"))) (lambda args (syslog "~a~%" args)))) (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))))