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1 | ;;; GNU Guix --- Functional package management for GNU |
2 | ;;; Copyright © 2014, 2015, 2016 Ludovic Courtès <ludo@gnu.org> | |
3 | ;;; | |
4 | ;;; This file is part of GNU Guix. | |
5 | ;;; | |
6 | ;;; GNU Guix is free software; you can redistribute it and/or modify it | |
7 | ;;; under the terms of the GNU General Public License as published by | |
8 | ;;; the Free Software Foundation; either version 3 of the License, or (at | |
9 | ;;; your option) any later version. | |
10 | ;;; | |
11 | ;;; GNU Guix is distributed in the hope that it will be useful, but | |
12 | ;;; WITHOUT ANY WARRANTY; without even the implied warranty of | |
13 | ;;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
14 | ;;; GNU General Public License for more details. | |
15 | ;;; | |
16 | ;;; You should have received a copy of the GNU General Public License | |
17 | ;;; along with GNU Guix. If not, see <http://www.gnu.org/licenses/>. | |
18 | ||
19 | (define-module (gnu system mapped-devices) | |
374f14c2 | 20 | #:use-module (guix gexp) |
060d62a7 | 21 | #:use-module (guix records) |
1ea507bc LC |
22 | #:use-module (gnu services) |
23 | #:use-module (gnu services shepherd) | |
374f14c2 | 24 | #:autoload (gnu packages cryptsetup) (cryptsetup) |
1ea507bc | 25 | #:use-module (ice-9 match) |
060d62a7 LC |
26 | #:export (mapped-device |
27 | mapped-device? | |
28 | mapped-device-source | |
29 | mapped-device-target | |
30 | mapped-device-type | |
31 | ||
32 | mapped-device-kind | |
33 | mapped-device-kind? | |
34 | mapped-device-kind-open | |
374f14c2 LC |
35 | mapped-device-kind-close |
36 | ||
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37 | device-mapping-service-type |
38 | device-mapping-service | |
39 | ||
374f14c2 | 40 | luks-device-mapping)) |
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41 | |
42 | ;;; Commentary: | |
43 | ;;; | |
44 | ;;; This module supports "device mapping", a concept implemented by Linux's | |
45 | ;;; device-mapper. | |
46 | ;;; | |
47 | ;;; Code: | |
48 | ||
49 | (define-record-type* <mapped-device> mapped-device | |
50 | make-mapped-device | |
51 | mapped-device? | |
52 | (source mapped-device-source) ;string | |
53 | (target mapped-device-target) ;string | |
54 | (type mapped-device-type)) ;<mapped-device-kind> | |
55 | ||
56 | (define-record-type* <mapped-device-type> mapped-device-kind | |
57 | make-mapped-device-kind | |
58 | mapped-device-kind? | |
59 | (open mapped-device-kind-open) ;source target -> gexp | |
60 | (close mapped-device-kind-close ;source target -> gexp | |
61 | (default (const #~(const #f))))) | |
62 | ||
374f14c2 | 63 | \f |
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64 | ;;; |
65 | ;;; Device mapping as a Shepherd service. | |
66 | ;;; | |
67 | ||
68 | (define device-mapping-service-type | |
69 | (shepherd-service-type | |
70 | 'device-mapping | |
71 | (match-lambda | |
72 | ((target open close) | |
73 | (shepherd-service | |
74 | (provision (list (symbol-append 'device-mapping- (string->symbol target)))) | |
75 | (requirement '(udev)) | |
76 | (documentation "Map a device node using Linux's device mapper.") | |
77 | (start #~(lambda () #$open)) | |
78 | (stop #~(lambda _ (not #$close))) | |
79 | (respawn? #f)))))) | |
80 | ||
81 | (define (device-mapping-service target open close) | |
82 | "Return a service that maps device @var{target}, a string such as | |
83 | @code{\"home\"} (meaning @code{/dev/mapper/home}). Evaluate @var{open}, a | |
84 | gexp, to open it, and evaluate @var{close} to close it." | |
85 | (service device-mapping-service-type | |
86 | (list target open close))) | |
87 | ||
88 | \f | |
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89 | ;;; |
90 | ;;; Common device mappings. | |
91 | ;;; | |
92 | ||
93 | (define (open-luks-device source target) | |
94 | "Return a gexp that maps SOURCE to TARGET as a LUKS device, using | |
95 | 'cryptsetup'." | |
96 | #~(zero? (system* (string-append #$cryptsetup "/sbin/cryptsetup") | |
97 | "open" "--type" "luks" | |
98 | #$source #$target))) | |
99 | ||
100 | (define (close-luks-device source target) | |
101 | "Return a gexp that closes TARGET, a LUKS device." | |
102 | #~(zero? (system* (string-append #$cryptsetup "/sbin/cryptsetup") | |
103 | "close" #$target))) | |
104 | ||
105 | (define luks-device-mapping | |
106 | ;; The type of LUKS mapped devices. | |
107 | (mapped-device-kind | |
108 | (open open-luks-device) | |
109 | (close close-luks-device))) | |
110 | ||
060d62a7 | 111 | ;;; mapped-devices.scm ends here |