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;;; GNU Guix --- Functional package management for GNU
;;; Copyright © 2013, 2014, 2015, 2016, 2017, 2018, 2019, 2020 Ludovic Courtès <ludo@gnu.org>
;;; Copyright © 2016 Chris Marusich <cmmarusich@gmail.com>
;;; Copyright © 2017 Leo Famulari <leo@famulari.name>
;;; Copyright © 2017, 2020 Mathieu Othacehe <m.othacehe@gmail.com>
;;; Copyright © 2019, 2020, 2023, 2024 Janneke Nieuwenhuizen <janneke@gnu.org>
;;; Copyright © 2019, 2020 Miguel Ángel Arruga Vivas <rosen644835@gmail.com>
;;; Copyright © 2020 Maxim Cournoyer <maxim.cournoyer@gmail.com>
;;; Copyright © 2020 Stefan <stefan-guix@vodafonemail.de>
;;; Copyright © 2022 Karl Hallsby <karl@hallsby.com>
;;; Copyright © 2022 Denis 'GNUtoo' Carikli <GNUtoo@cyberdimension.org>
;;; Copyright © 2024 Tomas Volf <~@wolfsden.cz>
;;; Copyright © 2024 Herman Rimm <herman@rimm.ee>
;;;
;;; 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 bootloader grub)
  #:use-module (guix build union)
  #:use-module (guix deprecation)
  #:use-module (guix records)
  #:use-module (guix store)
  #:use-module (guix utils)
  #:use-module (guix gexp)
  #:use-module (gnu artwork)
  #:use-module (gnu bootloader)
  #:use-module (gnu build file-systems)
  #:use-module (gnu system uuid)
  #:use-module (gnu system file-systems)
  #:use-module (gnu system keyboard)
  #:use-module (gnu system locale)
  #:use-module (gnu packages bootloaders)
  #:autoload   (gnu packages gtk) (guile-cairo guile-rsvg)
  #:autoload   (gnu packages xorg) (xkeyboard-config)
  #:use-module (ice-9 match)
  #:use-module (ice-9 regex)
  #:use-module (srfi srfi-1)
  #:use-module (srfi srfi-2)
  #:use-module (srfi srfi-26)
  #:export (grub-theme
            grub-theme?
            grub-theme-image
            grub-theme-resolution
            grub-theme-color-normal
            grub-theme-color-highlight
            grub-theme-gfxmode

            install-grub-efi-removable
            make-grub-efi-installer
            make-grub-efi-netboot-installer

            grub-bootloader
            grub-efi-bootloader
            grub-efi-removable-bootloader
            grub-efi32-bootloader
            grub-efi-netboot-bootloader
            grub-efi-netboot-removable-bootloader
            grub-mkrescue-bootloader
            grub-minimal-bootloader

            grub-configuration))

;;; Commentary:
;;;
;;; Configuration of GNU GRUB.
;;;
;;; Code:

(define* (normalize-file file mount-point store-directory-prefix)
  "Strip MOUNT-POINT and prepend STORE-DIRECTORY-PREFIX, if any, to FILE, a
G-expression or other lowerable object denoting a file name."

  (define (strip-mount-point mount-point file)
    (if mount-point
        (if (string=? mount-point "/")
            file
            #~(let ((file #$file))
                (if (string-prefix? #$mount-point file)
                    (substring #$file #$(string-length mount-point))
                    file)))
        file))

  (define (prepend-store-directory-prefix store-directory-prefix file)
    (if store-directory-prefix
        #~(string-append #$store-directory-prefix #$file)
        file))

  (prepend-store-directory-prefix store-directory-prefix
                                  (strip-mount-point mount-point file)))



(define-record-type* <grub-theme>
  ;; Default theme contributed by Felipe López.
  grub-theme make-grub-theme
  grub-theme?
  (image           grub-theme-image
                   (default (file-append %artwork-repository
                                         "/grub/GuixSD-fully-black-4-3.svg")))
  (resolution      grub-theme-resolution
                   (default '(1024 . 768)))
  (color-normal    grub-theme-color-normal
                   (default '((fg . light-gray) (bg . black))))
  (color-highlight grub-theme-color-highlight
                   (default '((fg . yellow) (bg . black))))
  (gfxmode         grub-theme-gfxmode
                   (default '("auto"))))          ;list of string


;;;
;;; Background image & themes.
;;;

(define (bootloader-theme config)
  "Return user defined theme in CONFIG if defined or a default theme
otherwise."
  (or (bootloader-configuration-theme config) (grub-theme)))

(define* (image->png image #:key width height)
  "Build a PNG of HEIGHT x WIDTH from IMAGE if its file suffix is \".svg\".
Otherwise the picture in IMAGE is just copied."
  (computed-file "grub-image.png"
                 (with-imported-modules '((gnu build svg))
                   (with-extensions (list guile-rsvg guile-cairo)
                     #~(if (string-suffix? ".svg" #+image)
                           (begin
                             (use-modules (gnu build svg))
                             (svg->png #+image #$output
                                       #:width #$width
                                       #:height #$height))
                           (copy-file #+image #$output))))))

(define* (grub-background-image config)
  "Return the GRUB background image defined in CONFIG or #f if none was found.
If the suffix of the image file is \".svg\", then it is converted into a PNG
file with the resolution provided in CONFIG."
  (let* ((theme (bootloader-theme config))
         (image (grub-theme-image theme)))
    (and image
         (match (grub-theme-resolution theme)
           (((? number? width) . (? number? height))
            (image->png image #:width width #:height height))
           (_ #f)))))

(define (grub-locale-directory grub)
  "Generate a directory with the locales from GRUB."
  (define builder
    #~(begin
        (use-modules (ice-9 ftw))
        (let ((locale (string-append #$grub "/share/locale"))
              (out    #$output))
          (mkdir out)
          (chdir out)
          (for-each (lambda (lang)
                      (let ((file (string-append locale "/" lang
                                                 "/LC_MESSAGES/grub.mo"))
                            (dest (string-append lang ".mo")))
                        (when (file-exists? file)
                          (copy-file file dest))))
                    (scandir locale)))))
  (computed-file "grub-locales" builder))

(define* (eye-candy config store-device store-mount-point
                    #:key store-directory-prefix port)
  "Return a gexp that writes to PORT (a port-valued gexp) the 'grub.cfg' part
concerned with graphics mode, background images, colors, and all that.
STORE-DEVICE designates the device holding the store, and STORE-MOUNT-POINT is
its mount point; these are used to determine where the background image and
fonts must be searched for.  STORE-DIRECTORY-PREFIX is a directory prefix to
prepend to any store file name."
  (define (setup-gfxterm config)
    (if (memq 'gfxterm (bootloader-configuration-terminal-outputs config))
        #~(format #f "
if loadfont unicode; then
  set gfxmode=~a
  insmod all_video
  insmod gfxterm
fi~%"
                  #$(string-join
                     (grub-theme-gfxmode (bootloader-theme config))
                     ";"))
        ""))

  (define (theme-colors type)
    (let* ((theme  (bootloader-theme config))
           (colors (type theme)))
      (string-append (symbol->string (assoc-ref colors 'fg)) "/"
                     (symbol->string (assoc-ref colors 'bg)))))

  (define image
    (normalize-file (grub-background-image config)
                    store-mount-point
                    store-directory-prefix))

  (and image
       #~(format #$port "
# Set 'root' to the partition that contains /gnu/store.
~a

~a
~a

insmod png
if background_image ~a; then
  set color_normal=~a
  set color_highlight=~a
else
  set menu_color_normal=cyan/blue
  set menu_color_highlight=white/blue
fi~%"
                 #$(grub-root-search store-device image)
                 #$(setup-gfxterm config)
                 #$(grub-setup-io config)

                 #$image
                 #$(theme-colors grub-theme-color-normal)
                 #$(theme-colors grub-theme-color-highlight))))


;;;
;;; Configuration file.
;;;

(define* (keyboard-layout-file layout
                               #:key
                               (grub grub))
  "Process the X keyboard layout description LAYOUT, a <keyboard-layout> record,
and return a file in the format for GRUB keymaps.  LAYOUT must be present in
the 'share/X11/xkb/symbols/' directory of 'xkeyboard-config'."
  (define builder
    (with-imported-modules '((guix build utils))
      #~(begin
          (use-modules (guix build utils))

          ;; 'grub-kbdcomp' passes all its arguments but '-o' to 'ckbcomp'
          ;; (from the 'console-setup' package).
          (invoke #+(file-append grub "/bin/grub-mklayout")
                  "-i" #+(keyboard-layout->console-keymap layout)
                  "-o" #$output))))

  (computed-file (string-append "grub-keymap."
                                (string-map (match-lambda
                                              (#\, #\-)
                                              (chr chr))
                                            (keyboard-layout-name layout)))
                 builder))

(define (grub-setup-io config)
  "Return GRUB commands to configure the input / output interfaces.  The result
is a string that can be inserted in grub.cfg."
  (let* ((symbols->string (lambda (list)
                           (string-join (map symbol->string list) " ")))
         (outputs (bootloader-configuration-terminal-outputs config))
         (inputs (bootloader-configuration-terminal-inputs config))
         (unit (bootloader-configuration-serial-unit config))
         (speed (bootloader-configuration-serial-speed config))

         ;; Respectively, GRUB_TERMINAL_OUTPUT and GRUB_TERMINAL_INPUT,
         ;; as documented in GRUB manual section "Simple Configuration
         ;; Handling".
         (valid-outputs '(console serial serial_0 serial_1 serial_2 serial_3
                          gfxterm vga_text mda_text morse spkmodem))
         (valid-inputs '(console serial serial_0 serial_1 serial_2 serial_3
                         at_keyboard usb_keyboard))

         (io (string-append
              ;; UNIT and SPEED are arguments to the same GRUB command
              ;; ("serial"), so we process them together.
              (if (or unit speed)
                  (string-append
                   "serial"
                   (if unit
                       ;; COM ports 1 through 4
                       (if (and (exact-integer? unit) (<= unit 3) (>= unit 0))
                           (string-append " --unit=" (number->string unit))
                           #f)
                       "")
                   (if speed
                       (if (exact-integer? speed)
                           (string-append " --speed=" (number->string speed))
                           #f)
                       "")
                   "\n")
                  "")
              (if (null? inputs)
                  ""
                  (string-append
                   "terminal_input "
                   (symbols->string
                    (map
                     (lambda (input)
                       (if (memq input valid-inputs) input #f)) inputs))
                   "\n"))
              "terminal_output "
              (symbols->string
               (map
                (lambda (output)
                  (if (memq output valid-outputs) output #f)) outputs)))))
    (format #f "~a" io)))

(define (grub-root-search device file)
  "Return the GRUB 'search' command to look for DEVICE, which contains FILE,
a gexp.  The result is a gexp that can be inserted in the grub.cfg-generation
code."
  ;; Usually FILE is a file name gexp like "/gnu/store/…-linux/vmlinuz", but
  ;; it can also be something like "(hd0,msdos1)/vmlinuz" in the case of
  ;; custom menu entries.  In the latter case, don't emit a 'search' command.
  (if (and (string? file) (not (string-prefix? "/" file)))
      ""
      (match device
        ;; Preferably refer to DEVICE by its UUID or label.  This is more
        ;; efficient and less ambiguous, see <http://bugs.gnu.org/22281>.
        ((? uuid? uuid)
         (format #f "search --fs-uuid --set ~a"
                 (uuid->string device)))
        ((? file-system-label? label)
         (format #f "search --label --set ~a"
                 (file-system-label->string label)))
        ((? (lambda (device)
              (and (string? device) (string-contains device ":/"))) nfs-uri)
         ;; If the device is an NFS share, then we assume that the expected
         ;; file on that device (e.g. the GRUB background image or the kernel)
         ;; has to be loaded over the network.  Otherwise we would need an
         ;; additional device information for some local disk to look for that
         ;; file, which we do not have.
         ;;
         ;; We explicitly set "root=(tftp)" here even though if grub.cfg
         ;; had been loaded via TFTP, Grub would have set "root=(tftp)"
         ;; automatically anyway.  The reason is if you have a system that
         ;; used to be on NFS but now is local, root would be set to local
         ;; disk.  If you then selected an older system generation that is
         ;; supposed to boot from network in the Grub boot menu, Grub still
         ;; wouldn't load those files from network otherwise.
         ;;
         ;; TFTP is preferred to HTTP because it is used more widely and
         ;; specified in standards more widely--especially BOOTP/DHCPv4
         ;; defines a TFTP server for DHCP option 66, but not HTTP.
         ;;
         ;; Note: DHCPv6 specifies option 59 to contain a boot-file-url,
         ;; which can contain a HTTP or TFTP URL.
         ;;
         ;; Note: It is assumed that the file paths are of a similar
         ;; setup on both the TFTP server and the NFS server (it is
         ;; not possible to search for files on TFTP).
         ;;
         ;; TODO: Allow HTTP.
         "set root=(tftp)")
        ((or #f (? string?))
         #~(format #f "search --file --set ~a" #$file)))))

(define* (device->hurd-device-name device-spec #:key (disk "w"))
  "Return DEVICE as a Hurd name spec: part:PART-NUMBER:device:DISKdDISK-INDEX."
  (let ((device-name (canonicalize-device-spec device-spec)))
    (device-name->hurd-device-name device-name #:disk disk)))

(define* (make-grub-configuration grub config entries
                                  #:key
                                  (locale #f)
                                  (system (%current-system))
                                  (old-entries '())
                                  (store-crypto-devices '())
                                  store-directory-prefix)
  "Return the GRUB configuration file corresponding to CONFIG, a
<bootloader-configuration> object, and where the store is available at
STORE-FS, a <file-system> object.  OLD-ENTRIES is taken to be a list of menu
entries corresponding to old generations of the system.
STORE-CRYPTO-DEVICES contain the UUIDs of the encrypted units that must
be unlocked to access the store contents.
STORE-DIRECTORY-PREFIX may be used to specify a store prefix, as is required
when booting a root file system on a Btrfs subvolume."
  (define all-entries
    (append entries (bootloader-configuration-menu-entries config)))
  (define (menu-entry->gexp entry)
    (let ((label (menu-entry-label entry))
          (linux (menu-entry-linux entry))
          (device (menu-entry-device entry))
          (device-mount-point (menu-entry-device-mount-point entry))
          (multiboot-kernel (menu-entry-multiboot-kernel entry))
          (chain-loader (menu-entry-chain-loader entry)))
      (cond
       (linux
        (let ((arguments (menu-entry-linux-arguments entry))
              (linux (normalize-file linux
                                     device-mount-point
                                     store-directory-prefix))
              (initrd (normalize-file (menu-entry-initrd entry)
                                      device-mount-point
                                      store-directory-prefix))
              (extra-initrd (bootloader-configuration-extra-initrd config)))
          ;; Here DEVICE is the store and DEVICE-MOUNT-POINT is its mount point.
          ;; Use the right file names for LINUX and INITRD in case
          ;; DEVICE-MOUNT-POINT is not "/", meaning that the store is on a
          ;; separate partition.

          ;; When STORE-DIRECTORY-PREFIX is defined, prepend it the linux and
          ;; initrd paths, to allow booting from a Btrfs subvolume.
          #~(format port "menuentry ~s {
  ~a
  linux ~a ~a
  initrd ~a ~a
}~%"
                    #$label
                    #$(grub-root-search device linux)
                    #$linux (string-join (list #$@arguments))
                    (or #$extra-initrd "")
                    #$initrd)))
       (multiboot-kernel
        (let* ((kernel (menu-entry-multiboot-kernel entry))
               (arguments (menu-entry-multiboot-arguments entry))
               ;; Choose between device names as understood by Mach's built-in
               ;; IDE driver ("hdX") and those understood by rumpdisk ("wdX"
               ;; in the "noide" case).
               (disk (if (member "noide" arguments) "w" "h"))
               (device-spec (and=> device file-system-device->string))
               (device-name (and=> device-spec device-spec->device-name))
               (modules (menu-entry-multiboot-modules entry)))
          #~(format port "
menuentry ~s {
  multiboot ~a root=~a~a~a
}~%"
                    #$label
                    #$kernel
                    #$(device-name->hurd-device-name device-name #:disk disk)
                    (string-join (list #$@arguments) " " 'prefix)
                    (string-join (map string-join '#$modules)
                                 "\n  module " 'prefix))))
       (chain-loader
        #~(format port "
menuentry ~s {
  ~a
  chainloader ~a
}~%"
                  #$label
                  #$(grub-root-search device chain-loader)
                  #$chain-loader)))))

  (define (crypto-devices)
    (define (crypto-device->cryptomount dev)
      (if (uuid? dev)
          #~(format port "cryptomount -u ~a~%"
                    ;; cryptomount only accepts UUID without the hypen.
                    #$(string-delete #\- (uuid->string dev)))
          ;; Other type of devices aren't implemented.
          #~()))
    (let ((devices (map crypto-device->cryptomount store-crypto-devices))
          (modules #~(format port "insmod luks~%insmod luks2~%")))
      (if (null? devices)
          devices
          (cons modules devices))))

  (define (sugar)
    (let* ((entry (first all-entries))
           (device (menu-entry-device entry))
           (mount-point (menu-entry-device-mount-point entry)))
      (eye-candy config
                 device
                 mount-point
                 #:store-directory-prefix store-directory-prefix
                 #:port #~port)))

  (define locale-config
    (let* ((entry (first all-entries))
           (device (menu-entry-device entry))
           (mount-point (menu-entry-device-mount-point entry)))
      #~(let ((locale #$(and locale
                             (locale-definition-source
                              (locale-name->definition locale))))
              (locales #$(and locale
                              (normalize-file (grub-locale-directory grub)
                                              mount-point
                                              store-directory-prefix))))
          (when locale
            (format port "\
# Localization configuration.
~asearch --file --set ~a/en@quot.mo
set locale_dir=~a
set lang=~a~%"
                    ;; Skip the search if there is an image, as it has already
                    ;; been performed by eye-candy and traversing the store is
                    ;; an expensive operation.
                    #$(if (grub-theme-image (bootloader-theme config))
                          "# "
                          "")
                    locales
                    locales
                    locale)))))

  (define keyboard-layout-config
    (let* ((layout (bootloader-configuration-keyboard-layout config))
           (keymap* (and layout
                         (keyboard-layout-file layout #:grub grub)))
           (entry (first all-entries))
           (device (menu-entry-device entry))
           (mount-point (menu-entry-device-mount-point entry))
           (keymap (and keymap*
                        (normalize-file keymap* mount-point
                                        store-directory-prefix))))
      #~(when #$keymap
          (format port "\
insmod keylayouts
keymap ~a~%" #$keymap))))

  (define builder
    #~(call-with-output-file #$output
        (lambda (port)
          (format port
                  "# This file was generated from your Guix configuration.  Any changes
# will be lost upon reconfiguration.
")
          #$@(crypto-devices)
          #$(sugar)
          #$locale-config
          #$keyboard-layout-config
          (format port "
set default=~a
set timeout=~a~%"
                  #$(bootloader-configuration-default-entry config)
                  #$(bootloader-configuration-timeout config))
          #$@(map menu-entry->gexp all-entries)

          #$@(if (pair? old-entries)
                 #~((format port "
submenu \"GNU system, old configurations...\" {~%")
                    #$@(map menu-entry->gexp old-entries)
                    (format port "}~%"))
                 #~())
          (format port "
if [ \"${grub_platform}\" == efi ]; then
  menuentry \"Firmware setup\" {
    fwsetup
  }
fi~%"))))

  ;; Since this file is rather unique, there's no point in trying to
  ;; substitute it.
  (computed-file "grub.cfg" builder
                 #:options '(#:local-build? #t
                             #:substitutable? #f)))

(define (grub-configuration-file config . args)
  (let* ((bootloader (bootloader-configuration-bootloader config))
         (grub (bootloader-package bootloader)))
    (apply make-grub-configuration grub config args)))

(define (grub-efi-configuration-file . args)
  (apply make-grub-configuration grub-efi args))

(define grub-cfg "/boot/grub/grub.cfg")



;;;
;;; Install procedures.
;;;

(define install-grub
  #~(lambda (bootloader device mount-point)
      (let ((grub (string-append bootloader "/sbin/grub-install"))
            (install-dir (string-append mount-point "/boot")))
        ;; Install GRUB on DEVICE which is mounted at MOUNT-POINT. If DEVICE
        ;; is #f, then we populate the disk-image rooted at MOUNT-POINT.
        (if device
            (begin
              ;; Tell 'grub-install' that there might be a LUKS-encrypted
              ;; /boot or root partition.
              (setenv "GRUB_ENABLE_CRYPTODISK" "y")

              ;; Hide potentially confusing messages from the user, such as
              ;; "Installing for i386-pc platform."
              (invoke/quiet grub "--no-floppy" "--target=i386-pc"
                            "--boot-directory" install-dir
                            device))
            ;; When creating a disk-image, only install a font and GRUB modules.
            (let* ((fonts (string-append install-dir "/grub/fonts")))
              (mkdir-p fonts)
              (copy-file (string-append bootloader "/share/grub/unicode.pf2")
                         (string-append fonts "/unicode.pf2"))
              (copy-recursively (string-append bootloader "/lib/")
                                install-dir))))))

(define install-grub-disk-image
  #~(lambda (bootloader root-index image)
      ;; Install GRUB on the given IMAGE. The root partition index is
      ;; ROOT-INDEX.
      (let ((grub-mkimage
             (string-append bootloader "/bin/grub-mkimage"))
            (modules '("biosdisk" "part_msdos" "fat" "ext2"))
            (grub-bios-setup
             (string-append bootloader "/sbin/grub-bios-setup"))
            (root-device (format #f "hd0,msdos~a" root-index))
            (boot-img (string-append bootloader "/lib/grub/i386-pc/boot.img"))
            (device-map "device.map"))

        ;; Create a minimal, standalone GRUB image that will be written
        ;; directly in the MBR-GAP (space between the end of the MBR and the
        ;; first partition).
        (apply invoke grub-mkimage
               "-O" "i386-pc"
               "-o" "core.img"
               "-p" (format #f "(~a)/boot/grub" root-device)
               modules)

        ;; Create a device mapping file.
        (call-with-output-file device-map
          (lambda (port)
            (format port "(hd0) ~a~%" image)))

        ;; Copy the default boot.img, that will be written on the MBR sector
        ;; by GRUB-BIOS-SETUP.
        (copy-file boot-img "boot.img")

        ;; Install both the "boot.img" and the "core.img" files on the given
        ;; IMAGE. On boot, the MBR sector will execute the minimal GRUB
        ;; written in the MBR-GAP. GRUB configuration and missing modules will
        ;; be read from ROOT-DEVICE.
        (invoke grub-bios-setup
                "-m" device-map
                "-r" root-device
                "-d" "."
                image))))

(define* (make-grub-efi-installer #:key efi32? removable?)
  "Return a G-expression of a procedure for installing GRUB on a UEFI
system.  If EFI32? is #t, then a 32-bit target will be used.  If
REMOVABLE? is #t, GRUB will be installed for Removable Media Boot."
  (define extra-args
    (list (and efi32?
               #~(cond ((target-x86?) "--target=i386-efi")
                       ((target-arm?) "--target=arm-efi")))
          ;; This does not update UEFI boot entries, like --no-nvram.
          (and removable? "--removable")))
  #~(lambda (bootloader efi-dir mount-point)
      ;; There is nothing useful to do when called in the context of a disk
      ;; image generation.
      (when efi-dir
        ;; Install GRUB onto the EFI partition mounted at EFI-DIR, for the
        ;; system whose root is mounted at MOUNT-POINT.
        (let ((grub-install (string-append bootloader "/sbin/grub-install"))
              (install-dir (string-append mount-point "/boot"))
              ;; When installing Guix, it's common to mount EFI-DIR below
              ;; MOUNT-POINT rather than /boot/efi on the live image.
              (target-esp (if (file-exists? (string-append mount-point efi-dir))
                              (string-append mount-point efi-dir)
                              efi-dir)))
          ;; Tell 'grub-install' that there might be a LUKS-encrypted /boot or
          ;; root partition.
          (setenv "GRUB_ENABLE_CRYPTODISK" "y")
          (invoke/quiet grub-install "--bootloader-id=Guix"
                        "--boot-directory" install-dir
                        "--efi-directory" target-esp
                        #$@(filter identity extra-args))))))

(define* (make-grub-efi-netboot-installer grub-efi grub-cfg subdir)
  "Make a bootloader-installer for a grub-efi-netboot bootloader, which expects
its files in SUBDIR and its configuration file in GRUB-CFG.

As a grub-efi-netboot package is already pre-installed by 'grub-mknetdir', the
installer basically copies all files from the bootloader-package (or profile)
into the bootloader-target directory.

Additionally for network booting over TFTP, two relative symlinks to the store
and to the GRUB-CFG file are necessary.  Due to this a TFTP root directory must
not be located on a FAT file-system.

If the bootloader-target does not support symlinks, then it is assumed to be a
kind of EFI System Partition (ESP).  In this case an intermediate configuration
file is created with the help of GRUB-EFI to load the GRUB-CFG.

The installer is usable for any efi-bootloader-chain, which prepares the
bootloader-profile in a way ready for copying.

The installer does not manipulate the system's 'UEFI Boot Manager'.

The returned installer accepts the BOOTLOADER, TARGET and MOUNT-POINT
arguments.  Its job is to copy the BOOTLOADER, which must be a pre-installed
grub-efi-netboot package with a SUBDIR like efi/boot or efi/Guix, below the
directory TARGET for the system whose root is mounted at MOUNT-POINT.

MOUNT-POINT is the last argument in 'guix system init /etc/config.scm mnt/point'
or '/' for other 'guix system' commands.

Where TARGET comes from the targets argument given to the
bootloader-configuration in:

(operating-system
 (bootloader (bootloader-configuration
              (targets '(\"/boot/efi\"))
              …))
 …)

TARGET is required to be an absolute directory name, usually mounted via NFS,
and finally needs to be provided by a TFTP server as
the TFTP root directory.

Usually the installer will be used to prepare network booting over TFTP.  Then
GRUB will load tftp://server/SUBDIR/grub.cfg and this file will instruct it to
load more files from the store like tftp://server/gnu/store/…-linux…/Image.

To make this possible two symlinks are created.  The first symlink points
relatively form MOUNT-POINT/TARGET/SUBDIR/grub.cfg to
MOUNT-POINT/boot/grub/grub.cfg, and the second symlink points relatively from
MOUNT-POINT/TARGET/%store-prefix to MOUNT-POINT/%store-prefix.

It is important to note that these symlinks need to be relative, as the absolute
paths on the TFTP server side are unknown.

It is also important to note that both symlinks will point outside the TFTP root
directory and that the TARGET/%store-prefix symlink makes the whole store
accessible via TFTP.  Possibly the TFTP server must be configured to allow
accesses outside its TFTP root directory.  This all may need to be considered
for security aspects.  It is advised to disable any TFTP write access!

The installer can also be used to prepare booting from local storage, if the
underlying file-system, like FAT on an EFI System Partition (ESP), does not
support symlinks.  In this case the MOUNT-POINT/TARGET/SUBDIR/grub.cfg will be
created with the help of GRUB-EFI to load the /boot/grub/grub.cfg file.  A
symlink to the store is not needed in this case."
  (with-imported-modules '((guix build union))
    #~(lambda (bootloader target mount-point)
        ;; In context of a disk image creation TARGET will be #f and an
        ;; installer is expected to do necessary installations on MOUNT-POINT,
        ;; which will become the root file system.  If TARGET is #f, this
        ;; installer has nothing to do, as it only cares about the EFI System
        ;; Partition (ESP).
        (when target
          (use-modules ((guix build union) #:select (symlink-relative))
                       (ice-9 popen)
                       (ice-9 rdelim))
          (let* ((mount-point/target (string-append mount-point target "/"))
                 ;; When installing Guix, it is common to mount TARGET below
                 ;; MOUNT-POINT rather than the root directory.
                 (bootloader-target (if (file-exists? mount-point/target)
                                        mount-point/target
                                        target))
                 (store (string-append mount-point (%store-prefix)))
                 (store-link (string-append bootloader-target (%store-prefix)))
                 (grub-cfg (string-append mount-point #$grub-cfg))
                 (grub-cfg-link (string-append bootloader-target
                                               #$subdir "/"
                                               (basename grub-cfg))))
            ;; Copy the bootloader into the bootloader-target directory.
            ;; Should we beforehand recursively delete any existing file?
            (copy-recursively bootloader bootloader-target
                              #:follow-symlinks? #t
                              #:log (%make-void-port "w"))
            ;; For TFTP we need to install additional relative symlinks.
            ;; If we install on an EFI System Partition (ESP) or some other FAT
            ;; file-system, then symlinks cannot be created and are not needed.
            ;; Therefore we ignore exceptions when trying.
            ;; Prepare the symlink to the grub.cfg.
            (mkdir-p (dirname grub-cfg-link))
            (false-if-exception (delete-file grub-cfg-link))
            (if (unspecified?
                 (false-if-exception (symlink-relative grub-cfg grub-cfg-link)))
                ;; Symlinks are supported.
                (begin
                  ;; Prepare the symlink to the store.
                  (mkdir-p (dirname store-link))
                  (false-if-exception (delete-file store-link))
                  (symlink-relative store store-link))
                ;; Creating symlinks does not seem to be supported.  Probably
                ;; an ESP is used.  Add a script to search and load the actual
                ;; grub.cfg.
                (let* ((probe #$(file-append grub-efi "/sbin/grub-probe"))
                       (port (open-pipe* OPEN_READ probe "--target=fs_uuid"
                                         grub-cfg))
                       (search-root
                        (match (read-line port)
                          ((? eof-object?)
                           ;; There is no UUID available. As a fallback search
                           ;; everywhere for the grub.cfg.
                           (string-append "search --file --set " #$grub-cfg))
                          (fs-uuid
                           ;; The UUID to load the grub.cfg from is known.
                           (string-append "search --fs-uuid --set " fs-uuid))))
                       (load-grub-cfg (string-append "configfile " #$grub-cfg)))
                  (close-pipe port)
                  (with-output-to-file grub-cfg-link
                    (lambda ()
                      (display (string-join (list search-root
                                                  load-grub-cfg)
                                            "\n")))))))))))



;;;
;;; Bootloader definitions.
;;;
;;; For all these grub-bootloader variables the path to /boot/grub/grub.cfg
;;; is fixed.  Inheriting and overwriting the field 'configuration-file' will
;;; break 'guix system delete-generations', 'guix system switch-generation',
;;; and 'guix system roll-back'.

(define grub-bootloader
  (bootloader
   (name 'grub)
   (package grub)
   (installer install-grub)
   (disk-image-installer install-grub-disk-image)
   (configuration-file grub-cfg)
   (configuration-file-generator grub-configuration-file)))

(define grub-minimal-bootloader
  (bootloader
   (inherit grub-bootloader)
   (package grub-minimal)))

(define grub-efi-bootloader
  (bootloader
   (name 'grub-efi)
   (package grub-efi)
   (installer (make-grub-efi-installer))
   (disk-image-installer #f)
   (configuration-file grub-cfg)
   (configuration-file-generator grub-configuration-file)))

(define grub-efi-removable-bootloader
  (bootloader
   (inherit grub-efi-bootloader)
   (name 'grub-efi-removable-bootloader)
   (installer (make-grub-efi-installer #:removable? #t))))

(define grub-efi32-bootloader
  (bootloader
   (inherit grub-efi-bootloader)
   (installer (make-grub-efi-installer #:efi32? #t))
   (name 'grub-efi32)
   (package grub-efi32)))

(define (make-grub-efi-netboot-bootloader name subdir)
  (bootloader
   (name name)
   (package (make-grub-efi-netboot (symbol->string name) subdir))
   (installer (make-grub-efi-netboot-installer grub-efi grub-cfg subdir))
   (disk-image-installer #f)
   (configuration-file grub-cfg)
   (configuration-file-generator grub-efi-configuration-file)))

(define grub-efi-netboot-bootloader
  (make-grub-efi-netboot-bootloader 'grub-efi-netboot-bootloader
                                    "efi/Guix"))

(define grub-efi-netboot-removable-bootloader
  (make-grub-efi-netboot-bootloader 'grub-efi-netboot-removable-bootloader
                                    "efi/boot"))

(define grub-mkrescue-bootloader
  (bootloader
   (inherit grub-efi-bootloader)
   (package grub-hybrid)))


;;;
;;; Compatibility macros.
;;;

(define-syntax grub-configuration
  (syntax-rules (grub)
                ((_ (grub package) fields ...)
                 (if (eq? package grub)
                     (bootloader-configuration
                      (bootloader grub-bootloader)
                      fields ...)
                   (bootloader-configuration
                    (bootloader grub-efi-bootloader)
                    fields ...)))
                ((_ fields ...)
                 (bootloader-configuration
                  (bootloader grub-bootloader)
                  fields ...))))


;;;
;;; Deprecated bootloader and installer variables.
;;;

(define-deprecated/alias install-grub-efi-removable
  (make-grub-efi-installer #:removable? #t))

;;; grub.scm ends here
generated by cgit
ref='#n1146'>1146 1147 1148 1149 1150 1151 1152 1153 1154 1155 1156 1157 1158 1159 1160 1161 1162 1163 1164 1165 1166 1167 1168 1169 1170 1171 1172 1173 1174 1175 1176 1177 1178 1179 1180 1181 1182 1183 1184 1185 1186 1187 1188 1189 1190 1191 1192 1193 1194 1195 1196 1197 1198 1199 1200 1201 1202 1203 1204 1205 1206 1207 1208 1209 1210 1211 1212 1213 1214 1215 1216 1217 1218 1219 1220 1221 1222 1223 1224 1225 1226 1227 1228 1229 1230 1231 1232 1233 1234 
#include "config.h"

#include "util.hh"
#include "affinity.hh"

#include <iostream>
#include <cerrno>
#include <cstdio>
#include <cstdlib>
#include <sstream>
#include <cstring>

#include <sys/wait.h>
#include <unistd.h>
#include <fcntl.h>
#include <limits.h>

#ifdef __APPLE__
#include <sys/syscall.h>
#endif

#ifdef __linux__
#include <sys/prctl.h>
#endif


extern char * * environ;


namespace nix {


BaseError::BaseError(const FormatOrString & fs, unsigned int status)
    : status(status)
{
    err = fs.s;
}


BaseError & BaseError::addPrefix(const FormatOrString & fs)
{
    prefix_ = fs.s + prefix_;
    return *this;
}


SysError::SysError(const FormatOrString & fs)
    : Error(format("%1%: %2%") % fs.s % strerror(errno))
    , errNo(errno)
{
}


string getEnv(const string & key, const string & def)
{
    char * value = getenv(key.c_str());
    return value ? string(value) : def;
}


Path absPath(Path path, Path dir)
{
    if (path[0] != '/') {
        if (dir == "") {
#ifdef __GNU__
            /* GNU (aka. GNU/Hurd) doesn't have any limitation on path
               lengths and doesn't define `PATH_MAX'.  */
            char *buf = getcwd(NULL, 0);
            if (buf == NULL)
#else
            char buf[PATH_MAX];
            if (!getcwd(buf, sizeof(buf)))
#endif
                throw SysError("cannot get cwd");
            dir = buf;
#ifdef __GNU__
            free(buf);
#endif
        }
        path = dir + "/" + path;
    }
    return canonPath(path);
}


Path canonPath(const Path & path, bool resolveSymlinks)
{
    string s;

    if (path[0] != '/')
        throw Error(format("not an absolute path: `%1%'") % path);

    string::const_iterator i = path.begin(), end = path.end();
    string temp;

    /* Count the number of times we follow a symlink and stop at some
       arbitrary (but high) limit to prevent infinite loops. */
    unsigned int followCount = 0, maxFollow = 1024;

    while (1) {

        /* Skip slashes. */
        while (i != end && *i == '/') i++;
        if (i == end) break;

        /* Ignore `.'. */
        if (*i == '.' && (i + 1 == end || i[1] == '/'))
            i++;

        /* If `..', delete the last component. */
        else if (*i == '.' && i + 1 < end && i[1] == '.' &&
            (i + 2 == end || i[2] == '/'))
        {
            if (!s.empty()) s.erase(s.rfind('/'));
            i += 2;
        }

        /* Normal component; copy it. */
        else {
            s += '/';
            while (i != end && *i != '/') s += *i++;

            /* If s points to a symlink, resolve it and restart (since
               the symlink target might contain new symlinks). */
            if (resolveSymlinks && isLink(s)) {
                if (++followCount >= maxFollow)
                    throw Error(format("infinite symlink recursion in path `%1%'") % path);
                temp = absPath(readLink(s), dirOf(s))
                    + string(i, end);
                i = temp.begin(); /* restart */
                end = temp.end();
                s = "";
            }
        }
    }

    return s.empty() ? "/" : s;
}


Path dirOf(const Path & path)
{
    Path::size_type pos = path.rfind('/');
    if (pos == string::npos)
        throw Error(format("invalid file name `%1%'") % path);
    return pos == 0 ? "/" : Path(path, 0, pos);
}


string baseNameOf(const Path & path)
{
    Path::size_type pos = path.rfind('/');
    if (pos == string::npos)
        throw Error(format("invalid file name `%1%'") % path);
    return string(path, pos + 1);
}


bool isInDir(const Path & path, const Path & dir)
{
    return path[0] == '/'
        && string(path, 0, dir.size()) == dir
        && path.size() >= dir.size() + 2
        && path[dir.size()] == '/';
}


struct stat lstat(const Path & path)
{
    struct stat st;
    if (lstat(path.c_str(), &st))
        throw SysError(format("getting status of `%1%'") % path);
    return st;
}


bool pathExists(const Path & path)
{
    int res;
#ifdef HAVE_STATX
    struct statx st;
    res = statx(AT_FDCWD, path.c_str(), AT_SYMLINK_NOFOLLOW, 0, &st);
#else
    struct stat st;
    res = lstat(path.c_str(), &st);
#endif
    if (!res) return true;
    if (errno != ENOENT && errno != ENOTDIR)
        throw SysError(format("getting status of %1%") % path);
    return false;
}


Path readLink(const Path & path)
{
    checkInterrupt();
    struct stat st = lstat(path);
    if (!S_ISLNK(st.st_mode))
        throw Error(format("`%1%' is not a symlink") % path);
    char buf[st.st_size];
    ssize_t rlsize = readlink(path.c_str(), buf, st.st_size);
    if (rlsize == -1)
        throw SysError(format("reading symbolic link '%1%'") % path);
    else if (rlsize > st.st_size)
        throw Error(format("symbolic link ‘%1%’ size overflow %2% > %3%")
            % path % rlsize % st.st_size);
    return string(buf, st.st_size);
}


bool isLink(const Path & path)
{
    struct stat st = lstat(path);
    return S_ISLNK(st.st_mode);
}


DirEntries readDirectory(const Path & path)
{
    DirEntries entries;
    entries.reserve(64);

    AutoCloseDir dir = opendir(path.c_str());
    if (!dir) throw SysError(format("opening directory `%1%'") % path);

    struct dirent * dirent;
    while (errno = 0, dirent = readdir(dir)) { /* sic */
        checkInterrupt();
        string name = dirent->d_name;
        if (name == "." || name == "..") continue;
        entries.emplace_back(name, dirent->d_ino, dirent->d_type);
    }
    if (errno) throw SysError(format("reading directory `%1%'") % path);

    return entries;
}


unsigned char getFileType(const Path & path)
{
    struct stat st = lstat(path);
    if (S_ISDIR(st.st_mode)) return DT_DIR;
    if (S_ISLNK(st.st_mode)) return DT_LNK;
    if (S_ISREG(st.st_mode)) return DT_REG;
    return DT_UNKNOWN;
}


string readFile(int fd)
{
    struct stat st;
    if (fstat(fd, &st) == -1)
        throw SysError("statting file");

    unsigned char * buf = new unsigned char[st.st_size];
    AutoDeleteArray<unsigned char> d(buf);
    readFull(fd, buf, st.st_size);

    return string((char *) buf, st.st_size);
}


string readFile(const Path & path, bool drain)
{
    AutoCloseFD fd = open(path.c_str(), O_RDONLY);
    if (fd == -1)
        throw SysError(format("opening file `%1%'") % path);
    return drain ? drainFD(fd) : readFile(fd);
}


void writeFile(const Path & path, const string & s)
{
    AutoCloseFD fd = open(path.c_str(), O_WRONLY | O_TRUNC | O_CREAT, 0666);
    if (fd == -1)
        throw SysError(format("opening file '%1%'") % path);
    writeFull(fd, s);
}


string readLine(int fd)
{
    string s;
    while (1) {
        checkInterrupt();
        char ch;
        ssize_t rd = read(fd, &ch, 1);
        if (rd == -1) {
            if (errno != EINTR)
                throw SysError("reading a line");
        } else if (rd == 0)
            throw EndOfFile("unexpected EOF reading a line");
        else {
            if (ch == '\n') return s;
            s += ch;
        }
    }
}


void writeLine(int fd, string s)
{
    s += '\n';
    writeFull(fd, s);
}


static void _deletePath(const Path & path, unsigned long long & bytesFreed, size_t linkThreshold)
{
    checkInterrupt();

    printMsg(lvlVomit, format("%1%") % path);

#ifdef HAVE_STATX
# define st_mode stx_mode
# define st_size stx_size
# define st_nlink stx_nlink
    struct statx st;
    if (statx(AT_FDCWD, path.c_str(),
	      AT_SYMLINK_NOFOLLOW,
	      STATX_SIZE | STATX_NLINK | STATX_MODE, &st) == -1)
	throw SysError(format("getting status of `%1%'") % path);
#else
    struct stat st = lstat(path);
#endif

    if (!S_ISDIR(st.st_mode) && st.st_nlink <= linkThreshold)
	bytesFreed += st.st_size;

    if (S_ISDIR(st.st_mode)) {
        /* Make the directory writable. */
        if (!(st.st_mode & S_IWUSR)) {
            if (chmod(path.c_str(), st.st_mode | S_IWUSR) == -1)
                throw SysError(format("making `%1%' writable") % path);
        }

        for (auto & i : readDirectory(path))
            _deletePath(path + "/" + i.name, bytesFreed, linkThreshold);
    }
#undef st_mode
#undef st_size
#undef st_nlink

    if (remove(path.c_str()) == -1)
        throw SysError(format("cannot unlink `%1%'") % path);
}


void deletePath(const Path & path)
{
    unsigned long long dummy;
    deletePath(path, dummy);
}


void deletePath(const Path & path, unsigned long long & bytesFreed, size_t linkThreshold)
{
    startNest(nest, lvlDebug,
        format("recursively deleting path `%1%'") % path);
    bytesFreed = 0;
    _deletePath(path, bytesFreed, linkThreshold);
}


static Path tempName(Path tmpRoot, const Path & prefix, bool includePid,
    int & counter)
{
    tmpRoot = canonPath(tmpRoot.empty() ? getEnv("TMPDIR", "/tmp") : tmpRoot, true);
    if (includePid)
        return (format("%1%/%2%-%3%-%4%") % tmpRoot % prefix % getpid() % counter++).str();
    else
        return (format("%1%/%2%-%3%") % tmpRoot % prefix % counter++).str();
}


Path createTempDir(const Path & tmpRoot, const Path & prefix,
    bool includePid, bool useGlobalCounter, mode_t mode)
{
    static int globalCounter = 0;
    int localCounter = 0;
    int & counter(useGlobalCounter ? globalCounter : localCounter);

    while (1) {
        checkInterrupt();
        Path tmpDir = tempName(tmpRoot, prefix, includePid, counter);
        if (mkdir(tmpDir.c_str(), mode) == 0) {
            /* Explicitly set the group of the directory.  This is to
               work around around problems caused by BSD's group
               ownership semantics (directories inherit the group of
               the parent).  For instance, the group of /tmp on
               FreeBSD is "wheel", so all directories created in /tmp
               will be owned by "wheel"; but if the user is not in
               "wheel", then "tar" will fail to unpack archives that
               have the setgid bit set on directories. */
            if (chown(tmpDir.c_str(), (uid_t) -1, getegid()) != 0)
                throw SysError(format("setting group of directory `%1%'") % tmpDir);
            return tmpDir;
        }
        if (errno != EEXIST)
            throw SysError(format("creating directory `%1%'") % tmpDir);
    }
}


Paths createDirs(const Path & path)
{
    Paths created;
    if (path == "/") return created;

    struct stat st;
    if (lstat(path.c_str(), &st) == -1) {
        created = createDirs(dirOf(path));
        if (mkdir(path.c_str(), 0777) == -1 && errno != EEXIST)
            throw SysError(format("creating directory `%1%'") % path);
        st = lstat(path);
        created.push_back(path);
    }

    if (S_ISLNK(st.st_mode) && stat(path.c_str(), &st) == -1)
        throw SysError(format("statting symlink `%1%'") % path);

    if (!S_ISDIR(st.st_mode)) throw Error(format("`%1%' is not a directory") % path);

    return created;
}


void createSymlink(const Path & target, const Path & link)
{
    if (symlink(target.c_str(), link.c_str()))
        throw SysError(format("creating symlink from `%1%' to `%2%'") % link % target);
}


LogType logType = ltPretty;
Verbosity verbosity = lvlInfo;

static int nestingLevel = 0;


Nest::Nest()
{
    nest = false;
}


Nest::~Nest()
{
    close();
}


static string escVerbosity(Verbosity level)
{
    return std::to_string((int) level);
}


void Nest::open(Verbosity level, const FormatOrString & fs)
{
    if (level <= verbosity) {
        if (logType == ltEscapes)
            std::cerr << "\033[" << escVerbosity(level) << "p"
                      << fs.s << "\n";
        else
            printMsg_(level, fs);
        nest = true;
        nestingLevel++;
    }
}


void Nest::close()
{
    if (nest) {
        nestingLevel--;
        if (logType == ltEscapes)
            std::cerr << "\033[q";
        nest = false;
    }
}


void printMsg_(Verbosity level, const FormatOrString & fs)
{
    checkInterrupt();
    if (level > verbosity) return;
    string prefix;
    if (logType == ltPretty)
        for (int i = 0; i < nestingLevel; i++)
            prefix += "|   ";
    else if (logType == ltEscapes && level != lvlInfo)
        prefix = "\033[" + escVerbosity(level) + "s";
    string s = (format("%1%%2%\n") % prefix % fs.s).str();
    writeToStderr(s);
}


void warnOnce(bool & haveWarned, const FormatOrString & fs)
{
    if (!haveWarned) {
        printMsg(lvlError, format("warning: %1%") % fs.s);
        haveWarned = true;
    }
}


void writeToStderr(const string & s)
{
    try {
        if (_writeToStderr)
            _writeToStderr((const unsigned char *) s.data(), s.size());
        else
            writeFull(STDERR_FILENO, s);
    } catch (SysError & e) {
        /* Ignore failing writes to stderr if we're in an exception
           handler, otherwise throw an exception.  We need to ignore
           write errors in exception handlers to ensure that cleanup
           code runs to completion if the other side of stderr has
           been closed unexpectedly. */
        if (!std::uncaught_exception()) throw;
    }
}


void (*_writeToStderr) (const unsigned char * buf, size_t count) = 0;


void readFull(int fd, unsigned char * buf, size_t count)
{
    while (count) {
        checkInterrupt();
        ssize_t res = read(fd, (char *) buf, count);
        if (res == -1) {
            if (errno == EINTR) continue;
            throw SysError("reading from file");
        }
        if (res == 0) throw EndOfFile("unexpected end-of-file");
        count -= res;
        buf += res;
    }
}


void writeFull(int fd, const unsigned char * buf, size_t count)
{
    while (count) {
        checkInterrupt();
        ssize_t res = write(fd, (char *) buf, count);
        if (res == -1) {
            if (errno == EINTR) continue;
            throw SysError("writing to file");
        }
        count -= res;
        buf += res;
    }
}


void writeFull(int fd, const string & s)
{
    writeFull(fd, (const unsigned char *) s.data(), s.size());
}


string drainFD(int fd)
{
    string result;
    unsigned char buffer[4096];
    while (1) {
        checkInterrupt();
        ssize_t rd = read(fd, buffer, sizeof buffer);
        if (rd == -1) {
            if (errno != EINTR)
                throw SysError("reading from file");
        }
        else if (rd == 0) break;
        else result.append((char *) buffer, rd);
    }
    return result;
}



//////////////////////////////////////////////////////////////////////


AutoDelete::AutoDelete(const string & p, bool recursive) : path(p)
{
    del = true;
    this->recursive = recursive;
}

AutoDelete::~AutoDelete()
{
    try {
        if (del) {
            if (recursive)
                deletePath(path);
            else {
                if (remove(path.c_str()) == -1)
                    throw SysError(format("cannot unlink `%1%'") % path);
            }
        }
    } catch (...) {
        ignoreException();
    }
}

void AutoDelete::cancel()
{
    del = false;
}



//////////////////////////////////////////////////////////////////////


AutoCloseFD::AutoCloseFD()
{
    fd = -1;
}


AutoCloseFD::AutoCloseFD(int fd)
{
    this->fd = fd;
}


AutoCloseFD::AutoCloseFD(const AutoCloseFD & fd)
{
    /* Copying an AutoCloseFD isn't allowed (who should get to close
       it?).  But as an edge case, allow copying of closed
       AutoCloseFDs.  This is necessary due to tiresome reasons
       involving copy constructor use on default object values in STL
       containers (like when you do `map[value]' where value isn't in
       the map yet). */
    this->fd = fd.fd;
    if (this->fd != -1) abort();
}


AutoCloseFD::~AutoCloseFD()
{
    try {
        close();
    } catch (...) {
        ignoreException();
    }
}


void AutoCloseFD::operator =(int fd)
{
    if (this->fd != fd) close();
    this->fd = fd;
}


AutoCloseFD::operator int() const
{
    return fd;
}


void AutoCloseFD::close()
{
    if (fd != -1) {
        if (::close(fd) == -1)
            /* This should never happen. */
            throw SysError(format("closing file descriptor %1%") % fd);
        fd = -1;
    }
}


bool AutoCloseFD::isOpen()
{
    return fd != -1;
}


/* Pass responsibility for closing this fd to the caller. */
int AutoCloseFD::borrow()
{
    int oldFD = fd;
    fd = -1;
    return oldFD;
}


void Pipe::create()
{
    int fds[2];
    if (pipe(fds) != 0) throw SysError("creating pipe");
    readSide = fds[0];
    writeSide = fds[1];
    closeOnExec(readSide);
    closeOnExec(writeSide);
}



//////////////////////////////////////////////////////////////////////


AutoCloseDir::AutoCloseDir()
{
    dir = 0;
}


AutoCloseDir::AutoCloseDir(DIR * dir)
{
    this->dir = dir;
}


AutoCloseDir::~AutoCloseDir()
{
    close();
}


void AutoCloseDir::operator =(DIR * dir)
{
    this->dir = dir;
}


AutoCloseDir::operator DIR *()
{
    return dir;
}


void AutoCloseDir::close()
{
    if (dir) {
        closedir(dir);
        dir = 0;
    }
}


//////////////////////////////////////////////////////////////////////


Pid::Pid()
    : pid(-1), separatePG(false), killSignal(SIGKILL)
{
}


Pid::Pid(pid_t pid)
    : pid(pid), separatePG(false), killSignal(SIGKILL)
{
}


Pid::~Pid()
{
    kill();
}


void Pid::operator =(pid_t pid)
{
    if (this->pid != pid) kill();
    this->pid = pid;
    killSignal = SIGKILL; // reset signal to default
}


Pid::operator pid_t()
{
    return pid;
}


void Pid::kill(bool quiet)
{
    if (pid == -1 || pid == 0) return;

    if (!quiet)
        printMsg(lvlError, format("killing process %1%") % pid);

    /* Send the requested signal to the child.  If it has its own
       process group, send the signal to every process in the child
       process group (which hopefully includes *all* its children). */
    if (::kill(separatePG ? -pid : pid, killSignal) != 0)
        printMsg(lvlError, (SysError(format("killing process %1%") % pid).msg()));

    /* Wait until the child dies, disregarding the exit status. */
    int status;
    while (waitpid(pid, &status, 0) == -1) {
        checkInterrupt();
        if (errno != EINTR) {
            printMsg(lvlError,
                (SysError(format("waiting for process %1%") % pid).msg()));
            break;
        }
    }

    pid = -1;
}


int Pid::wait(bool block)
{
    assert(pid != -1);
    while (1) {
        int status;
        int res = waitpid(pid, &status, block ? 0 : WNOHANG);
        if (res == pid) {
            pid = -1;
            return status;
        }
        if (res == 0 && !block) return -1;
        if (errno != EINTR)
            throw SysError("cannot get child exit status");
        checkInterrupt();
    }
}


void Pid::setSeparatePG(bool separatePG)
{
    this->separatePG = separatePG;
}


void Pid::setKillSignal(int signal)
{
    this->killSignal = signal;
}


void killUser(uid_t uid)
{
    debug(format("killing all processes running under uid `%1%'") % uid);

    assert(uid != 0); /* just to be safe... */

    /* The system call kill(-1, sig) sends the signal `sig' to all
       users to which the current process can send signals.  So we
       fork a process, switch to uid, and send a mass kill. */

    Pid pid = startProcess([&]() {

        if (setuid(uid) == -1)
            throw SysError("setting uid");

        while (true) {
#ifdef __APPLE__
            /* OSX's kill syscall takes a third parameter that, among
               other things, determines if kill(-1, signo) affects the
               calling process. In the OSX libc, it's set to true,
               which means "follow POSIX", which we don't want here
                 */
            if (syscall(SYS_kill, -1, SIGKILL, false) == 0) break;
#elif __GNU__
            /* Killing all a user's processes using PID=-1 does currently
               not work on the Hurd.  */
            if (kill(getpid(), SIGKILL) == 0) break;
#else
            if (kill(-1, SIGKILL) == 0) break;
#endif
            if (errno == ESRCH) break; /* no more processes */
            if (errno != EINTR)
                throw SysError(format("cannot kill processes for uid `%1%'") % uid);
        }

        _exit(0);
    });

    int status = pid.wait(true);
#if __GNU__
    /* When the child killed itself, status = SIGKILL.  */
    if (status == SIGKILL) return;
#endif
    if (status != 0)
        throw Error(format("cannot kill processes for uid `%1%': %2%") % uid % statusToString(status));

    /* !!! We should really do some check to make sure that there are
       no processes left running under `uid', but there is no portable
       way to do so (I think).  The most reliable way may be `ps -eo
       uid | grep -q $uid'. */
}


//////////////////////////////////////////////////////////////////////


pid_t startProcess(std::function<void()> fun,
    bool dieWithParent, const string & errorPrefix, bool runExitHandlers)
{
    pid_t pid = fork();
    if (pid == -1) throw SysError("unable to fork");

    if (pid == 0) {
        _writeToStderr = 0;
        try {
#if __linux__
            if (dieWithParent && prctl(PR_SET_PDEATHSIG, SIGKILL) == -1)
                throw SysError("setting death signal");
#endif
            restoreAffinity();
            fun();
        } catch (std::exception & e) {
            try {
                std::cerr << errorPrefix << e.what() << "\n";
            } catch (...) { }
        } catch (...) { }
        if (runExitHandlers)
            exit(1);
        else
            _exit(1);
    }

    return pid;
}


std::vector<char *> stringsToCharPtrs(const Strings & ss)
{
    std::vector<char *> res;
    for (auto & s : ss) res.push_back((char *) s.c_str());
    res.push_back(0);
    return res;
}


string runProgram(Path program, bool searchPath, const Strings & args)
{
    checkInterrupt();

    /* Create a pipe. */
    Pipe pipe;
    pipe.create();

    /* Fork. */
    Pid pid = startProcess([&]() {
        if (dup2(pipe.writeSide, STDOUT_FILENO) == -1)
            throw SysError("dupping stdout");

        Strings args_(args);
        args_.push_front(program);

        if (searchPath)
            execvp(program.c_str(), stringsToCharPtrs(args_).data());
        else
            execv(program.c_str(), stringsToCharPtrs(args_).data());

        throw SysError(format("executing `%1%'") % program);
    });

    pipe.writeSide.close();

    string result = drainFD(pipe.readSide);

    /* Wait for the child to finish. */
    int status = pid.wait(true);
    if (!statusOk(status))
        throw ExecError(format("program `%1%' %2%")
            % program % statusToString(status));

    return result;
}


void closeMostFDs(const set<int> & exceptions)
{
    int maxFD = 0;
    maxFD = sysconf(_SC_OPEN_MAX);
    for (int fd = 0; fd < maxFD; ++fd)
        if (fd != STDIN_FILENO && fd != STDOUT_FILENO && fd != STDERR_FILENO
            && exceptions.find(fd) == exceptions.end())
            close(fd); /* ignore result */
}


void closeOnExec(int fd)
{
    int prev;
    if ((prev = fcntl(fd, F_GETFD, 0)) == -1 ||
        fcntl(fd, F_SETFD, prev | FD_CLOEXEC) == -1)
        throw SysError("setting close-on-exec flag");
}


//////////////////////////////////////////////////////////////////////


volatile sig_atomic_t _isInterrupted = 0;

void _interrupted()
{
    /* Block user interrupts while an exception is being handled.
       Throwing an exception while another exception is being handled
       kills the program! */
    if (!std::uncaught_exception()) {
        _isInterrupted = 0;
        throw Interrupted("interrupted by the user");
    }
}



//////////////////////////////////////////////////////////////////////


template<class C> C tokenizeString(const string & s, const string & separators)
{
    C result;
    string::size_type pos = s.find_first_not_of(separators, 0);
    while (pos != string::npos) {
        string::size_type end = s.find_first_of(separators, pos + 1);
        if (end == string::npos) end = s.size();
        string token(s, pos, end - pos);
        result.insert(result.end(), token);
        pos = s.find_first_not_of(separators, end);
    }
    return result;
}

template Strings tokenizeString(const string & s, const string & separators);
template StringSet tokenizeString(const string & s, const string & separators);
template vector<string> tokenizeString(const string & s, const string & separators);


string concatStringsSep(const string & sep, const Strings & ss)
{
    string s;
    foreach (Strings::const_iterator, i, ss) {
        if (s.size() != 0) s += sep;
        s += *i;
    }
    return s;
}


string concatStringsSep(const string & sep, const StringSet & ss)
{
    string s;
    foreach (StringSet::const_iterator, i, ss) {
        if (s.size() != 0) s += sep;
        s += *i;
    }
    return s;
}


string chomp(const string & s)
{
    size_t i = s.find_last_not_of(" \n\r\t");
    return i == string::npos ? "" : string(s, 0, i + 1);
}


string statusToString(int status)
{
    if (!WIFEXITED(status) || WEXITSTATUS(status) != 0) {
        if (WIFEXITED(status))
            return (format("failed with exit code %1%") % WEXITSTATUS(status)).str();
        else if (WIFSIGNALED(status)) {
            int sig = WTERMSIG(status);
#if HAVE_STRSIGNAL
            const char * description = strsignal(sig);
            return (format("failed due to signal %1% (%2%)") % sig % description).str();
#else
            return (format("failed due to signal %1%") % sig).str();
#endif
        }
        else
            return "died abnormally";
    } else return "succeeded";
}


bool statusOk(int status)
{
    return WIFEXITED(status) && WEXITSTATUS(status) == 0;
}


bool hasSuffix(const string & s, const string & suffix)
{
    return s.size() >= suffix.size() && string(s, s.size() - suffix.size()) == suffix;
}


void expect(std::istream & str, const string & s)
{
    char s2[s.size()];
    str.read(s2, s.size());
    if (string(s2, s.size()) != s)
        throw FormatError(format("expected string `%1%'") % s);
}


string parseString(std::istream & str)
{
    string res;
    expect(str, "\"");
    int c;
    while ((c = str.get()) != '"')
        if (c == '\\') {
            c = str.get();
            if (c == 'n') res += '\n';
            else if (c == 'r') res += '\r';
            else if (c == 't') res += '\t';
            else res += c;
        }
        else res += c;
    return res;
}


bool endOfList(std::istream & str)
{
    if (str.peek() == ',') {
        str.get();
        return false;
    }
    if (str.peek() == ']') {
        str.get();
        return true;
    }
    return false;
}


void ignoreException()
{
    try {
        throw;
    } catch (std::exception & e) {
        printMsg(lvlError, format("error (ignored): %1%") % e.what());
    }
}

static const string pathNullDevice = "/dev/null";

/* Common initialisation performed in child processes. */
void commonChildInit(Pipe & logPipe)
{
    /* Put the child in a separate session (and thus a separate
       process group) so that it has no controlling terminal (meaning
       that e.g. ssh cannot open /dev/tty) and it doesn't receive
       terminal signals. */
    if (setsid() == -1)
        throw SysError(format("creating a new session"));

    /* Dup the write side of the logger pipe into stderr. */
    if (dup2(logPipe.writeSide, STDERR_FILENO) == -1)
        throw SysError("cannot pipe standard error into log file");

    /* Dup stderr to stdout. */
    if (dup2(STDERR_FILENO, STDOUT_FILENO) == -1)
        throw SysError("cannot dup stderr into stdout");

    /* Reroute stdin to /dev/null. */
    int fdDevNull = open(pathNullDevice.c_str(), O_RDWR);
    if (fdDevNull == -1)
        throw SysError(format("cannot open `%1%'") % pathNullDevice);
    if (dup2(fdDevNull, STDIN_FILENO) == -1)
        throw SysError("cannot dup null device into stdin");
    close(fdDevNull);
}

//////////////////////////////////////////////////////////////////////

Agent::Agent(const string &command, const Strings &args, const std::map<string, string> &env)
{
    debug(format("starting agent '%1%'") % command);

    /* Create a pipe to get the output of the child. */
    fromAgent.create();

    /* Create the communication pipes. */
    toAgent.create();

    /* Create a pipe to get the output of the builder. */
    builderOut.create();

    /* Fork the hook. */
    pid = startProcess([&]() {

        commonChildInit(fromAgent);

	for (auto pair: env) {
	    setenv(pair.first.c_str(), pair.second.c_str(), 1);
	}

        if (chdir("/") == -1) throw SysError("changing into `/");

        /* Dup the communication pipes. */
        if (dup2(toAgent.readSide, STDIN_FILENO) == -1)
            throw SysError("dupping to-hook read side");

        /* Use fd 4 for the builder's stdout/stderr. */
        if (dup2(builderOut.writeSide, 4) == -1)
            throw SysError("dupping builder's stdout/stderr");

	Strings allArgs;
	allArgs.push_back(command);
	allArgs.insert(allArgs.end(), args.begin(), args.end()); // append

        execv(command.c_str(), stringsToCharPtrs(allArgs).data());

        throw SysError(format("executing `%1%'") % command);
    });

    pid.setSeparatePG(true);
    fromAgent.writeSide.close();
    toAgent.readSide.close();
}


Agent::~Agent()
{
    try {
        toAgent.writeSide.close();
        pid.kill(true);
    } catch (...) {
        ignoreException();
    }
}


}
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