aboutsummaryrefslogtreecommitdiff
path: root/gnu/services/vpn.scm
blob: e1a04a9858b964b11e753a70c7c5fe6554211b63 (plain)
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
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
;;; GNU Guix --- Functional package management for GNU
;;; Copyright © 2017 Julien Lepiller <julien@lepiller.eu>
;;; Copyright © 2017 Clément Lassieur <clement@lassieur.org>
;;; Copyright © 2017 Mathieu Othacehe <m.othacehe@gmail.com>
;;;
;;; 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 services vpn)
  #:use-module (gnu services)
  #:use-module (gnu services configuration)
  #:use-module (gnu services shepherd)
  #:use-module (gnu system shadow)
  #:use-module (gnu packages admin)
  #:use-module (gnu packages vpn)
  #:use-module (guix packages)
  #:use-module (guix records)
  #:use-module (guix gexp)
  #:use-module (srfi srfi-1)
  #:use-module (ice-9 match)
  #:use-module (ice-9 regex)
  #:export (openvpn-client-service
            openvpn-server-service
            openvpn-client-service-type
            openvpn-server-service-type
            openvpn-client-configuration
            openvpn-server-configuration
            openvpn-remote-configuration
            openvpn-ccd-configuration
            generate-openvpn-client-documentation
            generate-openvpn-server-documentation))

;;;
;;; OpenVPN.
;;;

(define (uglify-field-name name)
  (match name
    ('verbosity "verb")
    (_ (let ((str (symbol->string name)))
         (if (string-suffix? "?" str)
             (substring str 0 (1- (string-length str)))
             str)))))

(define (serialize-field field-name val)
  (if (eq? field-name 'pid-file)
      (format #t "")
      (format #t "~a ~a\n" (uglify-field-name field-name) val)))
(define serialize-string serialize-field)
(define (serialize-boolean field-name val)
  (if val
      (serialize-field field-name val)
      (format #t "")))

(define (ip-mask? val)
  (and (string? val)
       (if (string-match "^([0-9]+\\.){3}[0-9]+ ([0-9]+\\.){3}[0-9]+$" val)
           (let ((numbers (string-tokenize val char-set:digit)))
             (all-lte numbers (list 255 255 255 255 255 255 255 255)))
           #f)))
(define serialize-ip-mask serialize-string)

(define-syntax define-enumerated-field-type
  (lambda (x)
    (define (id-append ctx . parts)
      (datum->syntax ctx (apply symbol-append (map syntax->datum parts))))
    (syntax-case x ()
      ((_ name (option ...))
       #`(begin
           (define (#,(id-append #'name #'name #'?) x)
             (memq x '(option ...)))
           (define (#,(id-append #'name #'serialize- #'name) field-name val)
             (serialize-field field-name val)))))))

(define-enumerated-field-type proto
  (udp tcp udp6 tcp6))
(define-enumerated-field-type dev
  (tun tap))

(define key-usage? boolean?)
(define (serialize-key-usage field-name value)
  (if value
      (format #t "remote-cert-tls server\n")
      #f))

(define bind? boolean?)
(define (serialize-bind field-name value)
  (if value
      #f
      (format #t "nobind\n")))

(define resolv-retry? boolean?)
(define (serialize-resolv-retry field-name value)
  (if value
      (format #t "resolv-retry infinite\n")
      #f))

(define (serialize-tls-auth role location)
  (serialize-field 'tls-auth
                   (string-append location " " (match role
                                                 ('server "0")
                                                 ('client "1")))))
(define (tls-auth? val)
  (or (eq? val #f)
      (string? val)))
(define (serialize-tls-auth-server field-name val)
  (serialize-tls-auth 'server val))
(define (serialize-tls-auth-client field-name val)
  (serialize-tls-auth 'client val))
(define tls-auth-server? tls-auth?)
(define tls-auth-client? tls-auth?)

(define (serialize-number field-name val)
  (serialize-field field-name (number->string val)))

(define (all-lte left right)
  (if (eq? left '())
      (eq? right '())
      (and (<= (string->number (car left)) (car right))
           (all-lte (cdr left) (cdr right)))))

(define (cidr4? val)
  (if (string? val)
      (if (string-match "^([0-9]+\\.){3}[0-9]+/[0-9]+$" val)
          (let ((numbers (string-tokenize val char-set:digit)))
            (all-lte numbers (list 255 255 255 255 32)))
          #f)
      (eq? val #f)))

(define (cidr6? val)
  (if (string? val)
      (string-match "^([0-9a-f]{0,4}:){0,8}/[0-9]{1,3}$" val)
      (eq? val #f)))

(define (serialize-cidr4 field-name val)
  (if (eq? val #f) #f (serialize-field field-name val)))

(define (serialize-cidr6 field-name val)
  (if (eq? val #f) #f (serialize-field field-name val)))

(define (ip? val)
  (if (string? val)
      (if (string-match "^([0-9]+\\.){3}[0-9]+$" val)
          (let ((numbers (string-tokenize val char-set:digit)))
            (all-lte numbers (list 255 255 255 255)))
          #f)
      (eq? val #f)))
(define (serialize-ip field-name val)
  (if (eq? val #f) #f (serialize-field field-name val)))

(define (keepalive? val)
  (and (list? val)
       (and (number? (car val))
            (number? (car (cdr val))))))
(define (serialize-keepalive field-name val)
  (format #t "~a ~a ~a\n" (uglify-field-name field-name)
          (number->string (car val)) (number->string (car (cdr val)))))

(define gateway? boolean?)
(define (serialize-gateway field-name val)
  (and val
       (format #t "push \"redirect-gateway\"\n")))


(define-configuration openvpn-remote-configuration
  (name
   (string "my-server")
   "Server name.")
  (port
   (number 1194)
   "Port number the server listens to."))

(define-configuration openvpn-ccd-configuration
  (name
   (string "client")
   "Client name.")
  (iroute
   (ip-mask #f)
   "Client own network")
  (ifconfig-push
   (ip-mask #f)
   "Client VPN IP."))

(define (openvpn-remote-list? val)
  (and (list? val)
       (or (eq? val '())
           (and (openvpn-remote-configuration? (car val))
                (openvpn-remote-list? (cdr val))))))
(define (serialize-openvpn-remote-list field-name val)
  (for-each (lambda (remote)
              (format #t "remote ~a ~a\n" (openvpn-remote-configuration-name remote)
                      (number->string (openvpn-remote-configuration-port remote))))
            val))

(define (openvpn-ccd-list? val)
  (and (list? val)
       (or (eq? val '())
           (and (openvpn-ccd-configuration? (car val))
                (openvpn-ccd-list? (cdr val))))))
(define (serialize-openvpn-ccd-list field-name val)
  #f)

(define (create-ccd-directory val)
  "Create a ccd directory containing files for the ccd configuration option
of OpenVPN.  Each file in this directory represents particular settings for a
client.  Each file is named after the name of the client."
  (let ((files (map (lambda (ccd)
                      (list (openvpn-ccd-configuration-name ccd)
                            (with-output-to-string
                              (lambda ()
                                (serialize-configuration
                                 ccd openvpn-ccd-configuration-fields)))))
                    val)))
    (computed-file "ccd"
                   (with-imported-modules '((guix build utils))
                     #~(begin
                         (use-modules (guix build utils))
                         (use-modules (ice-9 match))
                         (mkdir-p #$output)
                         (for-each
                          (lambda (ccd)
                            (match ccd
                              ((name config-string)
                               (call-with-output-file
                                   (string-append #$output "/" name)
                                 (lambda (port) (display config-string port))))))
                          '#$files))))))

(define-syntax define-split-configuration
  (lambda (x)
    (syntax-case x ()
      ((_ name1 name2 (common-option ...) (first-option ...) (second-option ...))
       #`(begin
           (define-configuration #,#'name1
             common-option ...
             first-option ...)
           (define-configuration #,#'name2
             common-option ...
             second-option ...))))))

(define-split-configuration openvpn-client-configuration
  openvpn-server-configuration
  ((openvpn
    (package openvpn)
    "The OpenVPN package.")

   (pid-file
    (string "/var/run/openvpn/openvpn.pid")
    "The OpenVPN pid file.")

   (proto
    (proto 'udp)
    "The protocol (UDP or TCP) used to open a channel between clients and
servers.")

   (dev
    (dev 'tun)
    "The device type used to represent the VPN connection.")

   (ca
    (string "/etc/openvpn/ca.crt")
    "The certificate authority to check connections against.")

   (cert
    (string "/etc/openvpn/client.crt")
    "The certificate of the machine the daemon is running on. It should be signed
by the authority given in @code{ca}.")

   (key
    (string "/etc/openvpn/client.key")
    "The key of the machine the daemon is running on. It must be the key whose
certificate is @code{cert}.")

   (comp-lzo?
    (boolean #t)
    "Whether to use the lzo compression algorithm.")

   (persist-key?
    (boolean #t)
    "Don't re-read key files across SIGUSR1 or --ping-restart.")

   (persist-tun?
    (boolean #t)
    "Don't close and reopen TUN/TAP device or run up/down scripts across
SIGUSR1 or --ping-restart restarts.")

   (verbosity
    (number 3)
    "Verbosity level."))
  ;; client-specific configuration
  ((tls-auth
    (tls-auth-client #f)
    "Add an additional layer of HMAC authentication on top of the TLS control
channel to protect against DoS attacks.")

   (verify-key-usage?
    (key-usage #t)
    "Whether to check the server certificate has server usage extension.")

   (bind?
    (bind #f)
    "Bind to a specific local port number.")

   (resolv-retry?
    (resolv-retry #t)
    "Retry resolving server address.")

   (remote
    (openvpn-remote-list '())
    "A list of remote servers to connect to."))
  ;; server-specific configuration
  ((tls-auth
    (tls-auth-server #f)
    "Add an additional layer of HMAC authentication on top of the TLS control
channel to protect against DoS attacks.")

   (port
    (number 1194)
    "Specifies the port number on which the server listens.")

   (server
    (ip-mask "10.8.0.0 255.255.255.0")
    "An ip and mask specifying the subnet inside the virtual network.")

   (server-ipv6
    (cidr6 #f)
    "A CIDR notation specifying the IPv6 subnet inside the virtual network.")

   (dh
    (string "/etc/openvpn/dh2048.pem")
    "The Diffie-Hellman parameters file.")

   (ifconfig-pool-persist
    (string "/etc/openvpn/ipp.txt")
    "The file that records client IPs.")

   (redirect-gateway?
    (gateway #f)
    "When true, the server will act as a gateway for its clients.")

   (client-to-client?
    (boolean #f)
    "When true, clients are alowed to talk to each other inside the VPN.")

   (keepalive
    (keepalive '(10 120))
    "Causes ping-like messages to be sent back and forth over the link so that
each side knows when the other side has gone down. @code{keepalive} requires
a pair. The first element is the period of the ping sending, and the second
element is the timeout before considering the other side down.")

   (max-clients
    (number 100)
    "The maximum number of clients.")

   (status
    (string "/var/run/openvpn/status")
    "The status file. This file shows a small report on current connection. It
is trunkated and rewritten every minute.")

   (client-config-dir
    (openvpn-ccd-list '())
    "The list of configuration for some clients.")))

(define (openvpn-config-file role config)
  (let ((config-str
         (with-output-to-string
           (lambda ()
             (serialize-configuration config
                                      (match role
                                        ('server
                                         openvpn-server-configuration-fields)
                                        ('client
                                         openvpn-client-configuration-fields))))))
        (ccd-dir (match role
                   ('server (create-ccd-directory
                             (openvpn-server-configuration-client-config-dir
                              config)))
                   ('client #f))))
    (computed-file "openvpn.conf"
                   #~(begin
                       (use-modules (ice-9 match))
                       (call-with-output-file #$output
                         (lambda (port)
                           (match '#$role
                             ('server (display "" port))
                             ('client (display "client\n" port)))
                           (display #$config-str port)
                           (match '#$role
                             ('server (display
                                       (string-append "client-config-dir "
                                                      #$ccd-dir "\n") port))
                             ('client (display "" port)))))))))

(define (openvpn-shepherd-service role)
  (lambda (config)
    (let* ((config-file (openvpn-config-file role config))
           (pid-file ((match role
                        ('server openvpn-server-configuration-pid-file)
                        ('client openvpn-client-configuration-pid-file))
                      config))
           (openvpn ((match role
                       ('server openvpn-server-configuration-openvpn)
                       ('client openvpn-client-configuration-openvpn))
                     config))
           (log-file (match role
                       ('server "/var/log/openvpn-server.log")
                       ('client "/var/log/openvpn-client.log"))))
      (list (shepherd-service
             (documentation (string-append "Run the OpenVPN "
                                           (match role
                                             ('server "server")
                                             ('client "client"))
                                           " daemon."))
             (provision (match role
                          ('server '(vpn-server))
                          ('client '(vpn-client))))
             (requirement '(networking))
             (start #~(make-forkexec-constructor
                       (list (string-append #$openvpn "/sbin/openvpn")
                             "--writepid" #$pid-file "--config" #$config-file
                             "--daemon")
                       #:pid-file #$pid-file))
             (stop #~(make-kill-destructor)))))))

(define %openvpn-accounts
  (list (user-group (name "openvpn") (system? #t))
        (user-account
         (name "openvpn")
         (group "openvpn")
         (system? #t)
         (comment "Openvpn daemon user")
         (home-directory "/var/empty")
         (shell (file-append shadow "/sbin/nologin")))))

(define %openvpn-activation
  #~(begin
      (use-modules (guix build utils))
      (mkdir-p "/var/run/openvpn")))

(define openvpn-server-service-type
  (service-type (name 'openvpn-server)
                (extensions
                 (list (service-extension shepherd-root-service-type
                                          (openvpn-shepherd-service 'server))
                       (service-extension account-service-type
                                          (const %openvpn-accounts))
                       (service-extension activation-service-type
                                          (const %openvpn-activation))))))

(define openvpn-client-service-type
  (service-type (name 'openvpn-client)
                (extensions
                 (list (service-extension shepherd-root-service-type
                                          (openvpn-shepherd-service 'client))
                       (service-extension account-service-type
                                          (const %openvpn-accounts))
                       (service-extension activation-service-type
                                          (const %openvpn-activation))))))

(define* (openvpn-client-service #:key (config (openvpn-client-configuration)))
  (validate-configuration config openvpn-client-configuration-fields)
  (service openvpn-client-service-type config))

(define* (openvpn-server-service #:key (config (openvpn-server-configuration)))
  (validate-configuration config openvpn-server-configuration-fields)
  (service openvpn-server-service-type config))

(define (generate-openvpn-server-documentation)
  (generate-documentation
   `((openvpn-server-configuration
      ,openvpn-server-configuration-fields
      (ccd openvpn-ccd-configuration))
     (openvpn-ccd-configuration ,openvpn-ccd-configuration-fields))
   'openvpn-server-configuration))

(define (generate-openvpn-client-documentation)
  (generate-documentation
   `((openvpn-client-configuration
      ,openvpn-client-configuration-fields
      (remote openvpn-remote-configuration))
     (openvpn-remote-configuration ,openvpn-remote-configuration-fields))
   'openvpn-client-configuration))