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1 | (* HCoop Domtool (http://hcoop.sourceforge.net/) |
2 | * Copyright (c) 2006, Adam Chlipala | |
3 | * | |
4 | * This program is free software; you can redistribute it and/or | |
5 | * modify it under the terms of the GNU General Public License | |
6 | * as published by the Free Software Foundation; either version 2 | |
7 | * of the License, or (at your option) any later version. | |
8 | * | |
9 | * This program is distributed in the hope that it will be useful, | |
10 | * but WITHOUT ANY WARRANTY; without even the implied warranty of | |
11 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
12 | * GNU General Public License for more details. | |
13 | * | |
14 | * You should have received a copy of the GNU General Public License | |
15 | * along with this program; if not, write to the Free Software | |
16 | * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA. | |
17 | *) | |
18 | ||
19 | (* Per-user access control lists for resources various *) | |
20 | ||
21 | structure Acl :> ACL = struct | |
22 | ||
23 | type acl = {user : string, | |
24 | class : string, | |
25 | value : string} | |
26 | ||
27 | structure SM = DataStructures.StringMap | |
28 | structure SS = DataStructures.StringSet | |
29 | ||
30 | val acl : SS.set SM.map SM.map ref = ref SM.empty | |
31 | ||
32 | fun query {user, class, value} = | |
33 | case SM.find (!acl, user) of | |
34 | NONE => false | |
35 | | SOME classes => | |
36 | case SM.find (classes, class) of | |
37 | NONE => false | |
38 | | SOME values => SS.member (values, value) | |
39 | ||
40 | fun class {user, class} = | |
41 | case SM.find (!acl, user) of | |
42 | NONE => SS.empty | |
43 | | SOME classes => | |
44 | case SM.find (classes, class) of | |
45 | NONE => SS.empty | |
46 | | SOME values => values | |
47 | ||
48 | fun grant {user, class, value} = | |
49 | let | |
50 | val classes = Option.getOpt (SM.find (!acl, user), SM.empty) | |
51 | val values = Option.getOpt (SM.find (classes, class), SS.empty) | |
52 | in | |
53 | acl := SM.insert (!acl, user, | |
54 | SM.insert (classes, class, | |
55 | SS.add (values, value))) | |
56 | end | |
57 | ||
58 | fun revoke {user, class, value} = | |
59 | let | |
60 | val classes = Option.getOpt (SM.find (!acl, user), SM.empty) | |
61 | val values = Option.getOpt (SM.find (classes, class), SS.empty) | |
62 | ||
63 | val values = if SS.member (values, value) then | |
64 | SS.delete (values, value) | |
65 | else | |
66 | values | |
67 | in | |
68 | acl := SM.insert (!acl, user, | |
69 | SM.insert (classes, class, | |
70 | values)) | |
71 | end | |
72 | ||
73 | fun read fname = | |
74 | let | |
75 | val inf = TextIO.openIn fname | |
76 | ||
77 | fun users usrs = | |
78 | case TextIO.inputLine inf of | |
79 | NONE => usrs | |
80 | | SOME line => | |
81 | case String.tokens Char.isSpace line of | |
82 | [user] => | |
83 | let | |
84 | fun classes clss = | |
85 | case TextIO.inputLine inf of | |
86 | NONE => clss | |
87 | | SOME line => | |
88 | case String.tokens Char.isSpace line of | |
89 | [] => clss | |
90 | | class :: values => | |
91 | classes (SM.insert (clss, class, | |
92 | foldl SS.add' SS.empty values)) | |
93 | in | |
94 | users (SM.insert (usrs, user, classes SM.empty)) | |
95 | end | |
96 | | _ => raise Fail "Unexpected ACL file format" | |
97 | in | |
98 | acl := users SM.empty | |
99 | before TextIO.closeIn inf | |
100 | end | |
101 | ||
102 | fun write fname = | |
103 | let | |
104 | val outf = TextIO.openOut fname | |
105 | ||
106 | val writeValues = SS.app (fn value => | |
107 | (TextIO.output (outf, " "); | |
108 | TextIO.output (outf, value))) | |
109 | ||
110 | val writeClasses = SM.appi (fn (class, values) => | |
111 | (TextIO.output (outf, class); | |
112 | writeValues values; | |
113 | TextIO.output (outf, "\n"))) | |
114 | ||
115 | val writeUsers = SM.appi (fn (user, classes) => | |
116 | (TextIO.output (outf, user); | |
117 | TextIO.output (outf, "\n"); | |
118 | writeClasses classes; | |
119 | TextIO.output (outf, "\n"))) | |
120 | in | |
121 | writeUsers (!acl); | |
122 | TextIO.closeOut outf | |
123 | end | |
124 | ||
125 | end |