254 lines
8.6 KiB
Scheme
254 lines
8.6 KiB
Scheme
;;; GNU Guix --- Functional package management for GNU
|
|
;;; Copyright © 2015 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 cpio)
|
|
#:use-module ((guix build utils) #:select (dump-port))
|
|
#:use-module (srfi srfi-9)
|
|
#:use-module (srfi srfi-11)
|
|
#:use-module (rnrs bytevectors)
|
|
#:use-module (rnrs io ports)
|
|
#:use-module (ice-9 match)
|
|
#:export (cpio-header?
|
|
make-cpio-header
|
|
file->cpio-header
|
|
file->cpio-header*
|
|
write-cpio-header
|
|
read-cpio-header
|
|
|
|
write-cpio-archive))
|
|
|
|
;;; Commentary:
|
|
;;;
|
|
;;; This module implements the cpio "new ASCII" format, bit-for-bit identical
|
|
;;; to GNU cpio with the '-H newc' option.
|
|
;;;
|
|
;;; Code:
|
|
|
|
;; Values for 'mode', OR'd together.
|
|
|
|
(define C_IRUSR #o000400)
|
|
(define C_IWUSR #o000200)
|
|
(define C_IXUSR #o000100)
|
|
(define C_IRGRP #o000040)
|
|
(define C_IWGRP #o000020)
|
|
(define C_IXGRP #o000010)
|
|
(define C_IROTH #o000004)
|
|
(define C_IWOTH #o000002)
|
|
(define C_IXOTH #o000001)
|
|
|
|
(define C_ISUID #o004000)
|
|
(define C_ISGID #o002000)
|
|
(define C_ISVTX #o001000)
|
|
|
|
(define C_FMT #o170000) ;bit mask
|
|
(define C_ISBLK #o060000)
|
|
(define C_ISCHR #o020000)
|
|
(define C_ISDIR #o040000)
|
|
(define C_ISFIFO #o010000)
|
|
(define C_ISSOCK #o0140000)
|
|
(define C_ISLNK #o0120000)
|
|
(define C_ISCTG #o0110000)
|
|
(define C_ISREG #o0100000)
|
|
|
|
|
|
(define MAGIC
|
|
;; The "new" portable format with ASCII header, as produced by GNU cpio with
|
|
;; '-H newc'.
|
|
(string->number "070701" 16))
|
|
|
|
(define (read-header-field size port)
|
|
(string->number (get-string-n port size) 16))
|
|
|
|
(define (write-header-field value size port)
|
|
(put-bytevector port
|
|
(string->utf8
|
|
(string-pad (string-upcase (number->string value 16))
|
|
size #\0))))
|
|
|
|
(define-syntax define-pack
|
|
(syntax-rules ()
|
|
((_ type ctor pred write read (field-names field-sizes field-getters) ...)
|
|
(begin
|
|
(define-record-type type
|
|
(ctor field-names ...)
|
|
pred
|
|
(field-names field-getters) ...)
|
|
|
|
(define (read port)
|
|
(set-port-encoding! port "ISO-8859-1")
|
|
(ctor (read-header-field field-sizes port)
|
|
...))
|
|
|
|
(define (write obj port)
|
|
(let* ((size (+ field-sizes ...)))
|
|
(match obj
|
|
(($ type field-names ...)
|
|
(write-header-field field-names field-sizes port)
|
|
...))))))))
|
|
|
|
;; cpio header in "new ASCII" format, without checksum.
|
|
(define-pack <cpio-header>
|
|
%make-cpio-header cpio-header?
|
|
write-cpio-header read-cpio-header
|
|
(magic 6 cpio-header-magic)
|
|
(ino 8 cpio-header-inode)
|
|
(mode 8 cpio-header-mode)
|
|
(uid 8 cpio-header-uid)
|
|
(gid 8 cpio-header-gid)
|
|
(nlink 8 cpio-header-nlink)
|
|
(mtime 8 cpio-header-mtime)
|
|
(file-size 8 cpio-header-file-size)
|
|
(dev-maj 8 cpio-header-device-major)
|
|
(dev-min 8 cpio-header-device-minor)
|
|
(rdev-maj 8 cpio-header-rdevice-major)
|
|
(rdev-min 8 cpio-header-rdevice-minor)
|
|
(name-size 8 cpio-header-name-size)
|
|
(checksum 8 cpio-header-checksum)) ;0 for "newc" format
|
|
|
|
(define* (make-cpio-header #:key
|
|
(inode 0)
|
|
(mode (logior C_ISREG C_IRUSR))
|
|
(uid 0) (gid 0)
|
|
(nlink 1) (mtime 0) (size 0)
|
|
(dev 0) (rdev 0) (name-size 0))
|
|
"Return a new cpio file header."
|
|
(let-values (((major minor) (device->major+minor dev))
|
|
((rmajor rminor) (device->major+minor rdev)))
|
|
(%make-cpio-header MAGIC
|
|
inode mode uid gid
|
|
nlink mtime
|
|
(if (= C_ISDIR (logand mode C_FMT))
|
|
0
|
|
size)
|
|
major minor rmajor rminor
|
|
(+ name-size 1) ;include trailing zero
|
|
0))) ;checksum
|
|
|
|
(define (mode->type mode)
|
|
"Given the number MODE, return a symbol representing the kind of file MODE
|
|
denotes, similar to 'stat:type'."
|
|
(let ((fmt (logand mode C_FMT)))
|
|
(cond ((= C_ISREG fmt) 'regular)
|
|
((= C_ISDIR fmt) 'directory)
|
|
((= C_ISLNK fmt) 'symlink)
|
|
(else
|
|
(error "unsupported file type" mode)))))
|
|
|
|
(define (device-number major minor) ;see <sys/sysmacros.h>
|
|
"Return the device number for the device with MAJOR and MINOR, for use as
|
|
the last argument of `mknod'."
|
|
(+ (* major 256) minor))
|
|
|
|
(define (device->major+minor device)
|
|
"Return two values: the major and minor device numbers that make up DEVICE."
|
|
(values (ash device -8)
|
|
(logand device #xff)))
|
|
|
|
(define* (file->cpio-header file #:optional (file-name file)
|
|
#:key (stat lstat))
|
|
"Return a cpio header corresponding to the info returned by STAT for FILE,
|
|
using FILE-NAME as its file name."
|
|
(let ((st (stat file)))
|
|
(make-cpio-header #:inode (stat:ino st)
|
|
#:mode (stat:mode st)
|
|
#:uid (stat:uid st)
|
|
#:gid (stat:gid st)
|
|
#:nlink (stat:nlink st)
|
|
#:mtime (stat:mtime st)
|
|
#:size (stat:size st)
|
|
#:dev (stat:dev st)
|
|
#:rdev (stat:rdev st)
|
|
#:name-size (string-length file-name))))
|
|
|
|
(define* (file->cpio-header* file
|
|
#:optional (file-name file)
|
|
#:key (stat lstat))
|
|
"Similar to 'file->cpio-header', but return a header with a zeroed
|
|
modification time, inode number, UID/GID, etc. This allows archives to be
|
|
produced in a deterministic fashion."
|
|
(let ((st (stat file)))
|
|
(make-cpio-header #:mode (stat:mode st)
|
|
#:nlink (stat:nlink st)
|
|
#:size (stat:size st)
|
|
#:name-size (string-length file-name))))
|
|
|
|
(define %trailer
|
|
"TRAILER!!!")
|
|
|
|
(define %last-header
|
|
;; The header that marks the end of the archive.
|
|
(make-cpio-header #:mode 0
|
|
#:name-size (string-length %trailer)))
|
|
|
|
(define* (write-cpio-archive files port
|
|
#:key (file->header file->cpio-header))
|
|
"Write to PORT a cpio archive in \"new ASCII\" format containing all of FILES.
|
|
|
|
The archive written to PORT is intended to be bit-identical to what GNU cpio
|
|
produces with the '-H newc' option."
|
|
(define (write-padding offset port)
|
|
(let ((padding (modulo (- 4 (modulo offset 4)) 4)))
|
|
(put-bytevector port (make-bytevector padding))))
|
|
|
|
(define (pad-block port)
|
|
;; Write padding to PORT such that we finish with a 512-byte block.
|
|
;; XXX: We rely on PORT's internal state, assuming it's a file port.
|
|
(let* ((offset (seek port 0 SEEK_CUR))
|
|
(padding (modulo (- 512 (modulo offset 512)) 512)))
|
|
(put-bytevector port (make-bytevector padding))))
|
|
|
|
(define (dump-file file)
|
|
(let* ((header (file->header file))
|
|
(size (cpio-header-file-size header)))
|
|
(write-cpio-header header port)
|
|
(put-bytevector port (string->utf8 file))
|
|
(put-u8 port 0)
|
|
|
|
;; We're padding the header + following file name + trailing zero, and
|
|
;; the header is 110 byte long.
|
|
(write-padding (+ 110 1 (string-length file)) port)
|
|
|
|
(case (mode->type (cpio-header-mode header))
|
|
((regular)
|
|
(call-with-input-file file
|
|
(lambda (input)
|
|
(dump-port input port))))
|
|
((symlink)
|
|
(let ((target (readlink file)))
|
|
(put-string port target)))
|
|
((directory)
|
|
#t)
|
|
(else
|
|
(error "file type not supported")))
|
|
|
|
;; Pad the file content.
|
|
(write-padding size port)))
|
|
|
|
(set-port-encoding! port "ISO-8859-1")
|
|
|
|
(for-each dump-file files)
|
|
|
|
(write-cpio-header %last-header port)
|
|
(put-bytevector port (string->utf8 %trailer))
|
|
(write-padding (string-length %trailer) port)
|
|
|
|
;; Pad so the last block is 512-byte long.
|
|
(pad-block port))
|
|
|
|
;;; cpio.scm ends here
|