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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 |