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
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
|
;;; GNU Guix --- Functional package management for GNU
;;; Copyright © 2016, 2017 Ludovic Courtès <ludo@gnu.org>
;;; Copyright © 2017 Danny Milosavljevic <dannym@scratchpost.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 system uuid)
#:use-module (srfi srfi-1)
#:use-module (rnrs bytevectors)
#:use-module (ice-9 match)
#:use-module (ice-9 vlist)
#:use-module (ice-9 regex)
#:use-module (ice-9 format)
#:export (uuid
uuid->string
dce-uuid->string
string->uuid
string->dce-uuid
string->iso9660-uuid
string->ext2-uuid
string->ext3-uuid
string->ext4-uuid
string->btrfs-uuid
iso9660-uuid->string
;; XXX: For lack of a better place.
sub-bytevector
latin1->string))
;;;
;;; Tools that lack a better place.
;;;
(define (sub-bytevector bv start size)
"Return a copy of the SIZE bytes of BV starting from offset START."
(let ((result (make-bytevector size)))
(bytevector-copy! bv start result 0 size)
result))
(define (latin1->string bv terminator)
"Return a string of BV, a latin1 bytevector, or #f. TERMINATOR is a predicate
that takes a number and returns #t when a termination character is found."
(let ((bytes (take-while (negate terminator) (bytevector->u8-list bv))))
(if (null? bytes)
#f
(list->string (map integer->char bytes)))))
;;;
;;; DCE UUIDs.
;;;
(define-syntax %network-byte-order
(identifier-syntax (endianness big)))
(define (dce-uuid->string uuid)
"Convert UUID, a 16-byte bytevector, to its string representation, something
like \"6b700d61-5550-48a1-874c-a3d86998990e\"."
;; See <https://tools.ietf.org/html/rfc4122>.
(let ((time-low (bytevector-uint-ref uuid 0 %network-byte-order 4))
(time-mid (bytevector-uint-ref uuid 4 %network-byte-order 2))
(time-hi (bytevector-uint-ref uuid 6 %network-byte-order 2))
(clock-seq (bytevector-uint-ref uuid 8 %network-byte-order 2))
(node (bytevector-uint-ref uuid 10 %network-byte-order 6)))
(format #f "~8,'0x-~4,'0x-~4,'0x-~4,'0x-~12,'0x"
time-low time-mid time-hi clock-seq node)))
(define %uuid-rx
;; The regexp of a UUID.
(make-regexp "^([[:xdigit:]]{8})-([[:xdigit:]]{4})-([[:xdigit:]]{4})-([[:xdigit:]]{4})-([[:xdigit:]]{12})$"))
(define (string->dce-uuid str)
"Parse STR as a DCE UUID (see <https://tools.ietf.org/html/rfc4122>) and
return its contents as a 16-byte bytevector. Return #f if STR is not a valid
UUID representation."
(and=> (regexp-exec %uuid-rx str)
(lambda (match)
(letrec-syntax ((hex->number
(syntax-rules ()
((_ index)
(string->number (match:substring match index)
16))))
(put!
(syntax-rules ()
((_ bv index (number len) rest ...)
(begin
(bytevector-uint-set! bv index number
(endianness big) len)
(put! bv (+ index len) rest ...)))
((_ bv index)
bv))))
(let ((time-low (hex->number 1))
(time-mid (hex->number 2))
(time-hi (hex->number 3))
(clock-seq (hex->number 4))
(node (hex->number 5))
(uuid (make-bytevector 16)))
(put! uuid 0
(time-low 4) (time-mid 2) (time-hi 2)
(clock-seq 2) (node 6)))))))
;;;
;;; ISO-9660.
;;;
;; <http://www.ecma-international.org/publications/files/ECMA-ST/Ecma-119.pdf>.
(define %iso9660-uuid-rx
;; Y m d H M S ss
(make-regexp "^([[:digit:]]{4})-([[:digit:]]{2})-([[:digit:]]{2})-([[:digit:]]{2})-([[:digit:]]{2})-([[:digit:]]{2})-([[:digit:]]{2})$"))
(define (string->iso9660-uuid str)
"Parse STR as a ISO9660 UUID (which is really a timestamp - see /dev/disk/by-uuid).
Return its contents as a 16-byte bytevector. Return #f if STR is not a valid
ISO9660 UUID representation."
(and=> (regexp-exec %iso9660-uuid-rx str)
(lambda (match)
(letrec-syntax ((match-numerals
(syntax-rules ()
((_ index (name rest ...) body)
(let ((name (match:substring match index)))
(match-numerals (+ 1 index) (rest ...) body)))
((_ index () body)
body))))
(match-numerals 1 (year month day hour minute second hundredths)
(string->utf8 (string-append year month day
hour minute second hundredths)))))))
(define (iso9660-uuid->string uuid)
"Given an UUID bytevector, return its timestamp string."
(define (digits->string bytes)
(latin1->string bytes (lambda (c) #f)))
(let* ((year (sub-bytevector uuid 0 4))
(month (sub-bytevector uuid 4 2))
(day (sub-bytevector uuid 6 2))
(hour (sub-bytevector uuid 8 2))
(minute (sub-bytevector uuid 10 2))
(second (sub-bytevector uuid 12 2))
(hundredths (sub-bytevector uuid 14 2))
(parts (list year month day hour minute second hundredths)))
(string-append (string-join (map digits->string parts) "-"))))
;;;
;;; FAT32.
;;;
(define-syntax %fat32-endianness
;; Endianness of FAT file systems.
(identifier-syntax (endianness little)))
(define (fat32-uuid->string uuid)
"Convert fat32 UUID, a 4-byte bytevector, to its string representation."
(let ((high (bytevector-uint-ref uuid 0 %fat32-endianness 2))
(low (bytevector-uint-ref uuid 2 %fat32-endianness 2)))
(format #f "~:@(~x-~x~)" low high)))
;;;
;;; Generic interface.
;;;
(define string->ext2-uuid string->dce-uuid)
(define string->ext3-uuid string->dce-uuid)
(define string->ext4-uuid string->dce-uuid)
(define string->btrfs-uuid string->dce-uuid)
(define-syntax vhashq
(syntax-rules (=>)
((_)
vlist-null)
((_ (key others ... => value) rest ...)
(vhash-consq key value
(vhashq (others ... => value) rest ...)))
((_ (=> value) rest ...)
(vhashq rest ...))))
(define %uuid-parsers
(vhashq
('dce 'ext2 'ext3 'ext4 'btrfs 'luks => string->dce-uuid)
('iso9660 => string->iso9660-uuid)))
(define %uuid-printers
(vhashq
('dce 'ext2 'ext3 'ext4 'btrfs 'luks => dce-uuid->string)
('iso9660 => iso9660-uuid->string)
('fat32 'fat => fat32-uuid->string)))
(define* (string->uuid str #:key (type 'dce))
"Parse STR as a UUID of the given TYPE. On success, return the
corresponding bytevector; otherwise return #f."
(match (vhash-assq type %uuid-parsers)
(#f #f)
((_ . (? procedure? parse)) (parse str))))
(define* (uuid->string bv #:key (type 'dce))
"Convert BV, a bytevector, to the UUID string representation for TYPE."
(match (vhash-assq type %uuid-printers)
(#f #f)
((_ . (? procedure? unparse)) (unparse bv))))
(define-syntax uuid
(lambda (s)
"Return the bytevector corresponding to the given UUID representation."
(syntax-case s ()
((_ str)
(string? (syntax->datum #'str))
;; A literal string: do the conversion at expansion time.
(let ((bv (string->uuid (syntax->datum #'str))))
(unless bv
(syntax-violation 'uuid "invalid UUID" s))
(datum->syntax #'str bv)))
((_ str)
#'(string->uuid str)))))
|
