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
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
|
;;; 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 scripts challenge)
#:use-module (guix ui)
#:use-module (guix scripts)
#:use-module (guix store)
#:use-module (guix utils)
#:use-module (guix monads)
#:use-module (guix base32)
#:use-module (guix packages)
#:use-module (guix serialization)
#:use-module (guix scripts substitute)
#:use-module (rnrs bytevectors)
#:use-module (srfi srfi-1)
#:use-module (srfi srfi-9)
#:use-module (srfi srfi-26)
#:use-module (srfi srfi-34)
#:use-module (srfi srfi-37)
#:use-module (ice-9 match)
#:use-module (ice-9 vlist)
#:use-module (ice-9 format)
#:use-module (web uri)
#:export (discrepancies
discrepancy?
discrepancy-item
discrepancy-local-sha256
discrepancy-narinfos
guix-challenge))
;;; Commentary:
;;;
;;; Challenge substitute servers, checking whether they provide the same
;;; binaries as those built locally.
;;;
;;; Here we completely bypass the daemon to access substitutes. This is
;;; because we want to be able to report fine-grain information about
;;; discrepancies: We need to show the URL of the offending nar, its hash, and
;;; so on.
;;;
;;; Code:
(define ensure-store-item ;XXX: move to (guix ui)?
(@@ (guix scripts size) ensure-store-item))
;; Representation of a hash mismatch for ITEM.
(define-record-type <discrepancy>
(discrepancy item local-sha256 narinfos)
discrepancy?
(item discrepancy-item) ;string, /gnu/store/… item
(local-sha256 discrepancy-local-sha256) ;bytevector | #f
(narinfos discrepancy-narinfos)) ;list of <narinfo>
(define (locally-built? store item)
"Return true if ITEM was built locally."
;; XXX: For now approximate it by checking whether there's a build log for
;; ITEM. There could be false negatives, if logs have been removed.
(->bool (log-file store item)))
(define (query-locally-built-hash item)
"Return the hash of ITEM, a store item, if ITEM was built locally.
Otherwise return #f."
(lambda (store)
(guard (c ((nix-protocol-error? c)
(values #f store)))
(if (locally-built? store item)
(values (query-path-hash store item) store)
(values #f store)))))
(define-syntax-rule (report args ...)
(format (current-error-port) args ...))
(define (discrepancies items servers)
"Challenge the substitute servers whose URLs are listed in SERVERS by
comparing the hash of the substitutes of ITEMS that they serve. Return the
list of discrepancies.
This procedure does not authenticate narinfos from SERVERS, nor does it verify
that they are signed by an authorized public keys. The reason is that, by
definition, we may want to target unknown servers. Furthermore, no risk is
taken since we do not import the archives."
(define (compare item reference)
;; Return a procedure to compare the hash of ITEM with REFERENCE.
(lambda (narinfo url)
(if (not narinfo)
(begin
(warning (_ "~a: no substitute at '~a'~%")
item url)
#t)
(let ((value (narinfo-hash->sha256 (narinfo-hash narinfo))))
(bytevector=? reference value)))))
(define (select-reference item narinfos urls)
;; Return a "reference" narinfo among NARINFOS.
(match narinfos
((first narinfos ...)
(match servers
((url urls ...)
(if (not first)
(select-reference item narinfos urls)
(narinfo-hash->sha256 (narinfo-hash first))))))
(()
(leave (_ "no substitutes for '~a'~%") item))))
(mlet* %store-monad ((local (mapm %store-monad
query-locally-built-hash items))
(remote -> (append-map (cut lookup-narinfos <> items)
servers))
;; No 'assert-valid-narinfo' on purpose.
(narinfos -> (fold (lambda (narinfo vhash)
(vhash-cons (narinfo-path narinfo) narinfo
vhash))
vlist-null
remote)))
(return (filter-map (lambda (item local)
(let ((narinfos (vhash-fold* cons '() item narinfos)))
(define reference
(or local
(begin
(warning (_ "no local build for '~a'~%") item)
(select-reference item narinfos servers))))
(if (every (compare item reference)
narinfos servers)
#f
(discrepancy item local narinfos))))
items
local))))
(define* (summarize-discrepancy discrepancy
#:key (hash->string
bytevector->nix-base32-string))
"Write to the current error port a summary of DISCREPANCY, a <discrepancy>
object that denotes a hash mismatch."
(match discrepancy
(($ <discrepancy> item local (narinfos ...))
(report (_ "~a contents differ:~%") item)
(if local
(report (_ " local hash: ~a~%") (hash->string local))
(warning (_ "no local build for '~a'~%") item))
(for-each (lambda (narinfo)
(if narinfo
(report (_ " ~50a: ~a~%")
(uri->string (narinfo-uri narinfo))
(hash->string
(narinfo-hash->sha256 (narinfo-hash narinfo))))
(report (_ " ~50a: unavailable~%")
(uri->string (narinfo-uri narinfo)))))
narinfos))))
;;;
;;; Command-line options.
;;;
(define (show-help)
(display (_ "Usage: guix challenge [PACKAGE...]
Challenge the substitutes for PACKAGE... provided by one or more servers.\n"))
(display (_ "
--substitute-urls=URLS
compare build results with those at URLS"))
(newline)
(display (_ "
-h, --help display this help and exit"))
(display (_ "
-V, --version display version information and exit"))
(newline)
(show-bug-report-information))
(define %options
(list (option '(#\h "help") #f #f
(lambda args
(show-help)
(exit 0)))
(option '(#\V "version") #f #f
(lambda args
(show-version-and-exit "guix challenge")))
(option '("substitute-urls") #t #f
(lambda (opt name arg result . rest)
(apply values
(alist-cons 'substitute-urls
(string-tokenize arg)
(alist-delete 'substitute-urls result))
rest)))))
(define %default-options
`((system . ,(%current-system))
(substitute-urls . ,%default-substitute-urls)))
;;;
;;; Entry point.
;;;
(define (guix-challenge . args)
(with-error-handling
(let* ((opts (parse-command-line args %options (list %default-options)))
(files (filter-map (match-lambda
(('argument . file) file)
(_ #f))
opts))
(system (assoc-ref opts 'system))
(urls (assoc-ref opts 'substitute-urls)))
(leave-on-EPIPE
(with-store store
(let ((files (match files
(()
(filter (cut locally-built? store <>)
(live-paths store)))
(x
files))))
(set-build-options store
#:use-substitutes? #f)
(run-with-store store
(mlet* %store-monad ((items (mapm %store-monad
ensure-store-item files))
(issues (discrepancies items urls)))
(for-each summarize-discrepancy issues)
(unless (null? issues)
(exit 1))
(return (null? issues)))
#:system system)))))))
;;; challenge.scm ends here
|
