1 //
2 // Copyright (c) 2013-2017 Carsten Sonne Larsen <cs@innolan.net>
3 //
4 // Permission is hereby granted, free of charge, to any person obtaining a copy
5 // of this software and associated documentation files (the "Software"), to deal
6 // in the Software without restriction, including without limitation the rights
7 // to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
8 // copies of the Software, and to permit persons to whom the Software is
9 // furnished to do so, subject to the following conditions:
10 //
11 // The above copyright notice and this permission notice shall be included in
12 // all copies or substantial portions of the Software.
13 //
14 // THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
15 // IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
16 // FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
17 // AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
18 // LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
19 // OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
20 // THE SOFTWARE.
21 
22 using System;
23 using Mono.Unix.Native;
24 
25 namespace Ntp.Common.IO
26 {
27     public static class Permission
28     {
ChangeFileMode(string file, uint mode)29         public static bool ChangeFileMode(string file, uint mode)
30         {
31             // Changing file mode is only supported on Unix platforms
32             if (Environment.OSVersion.Platform != PlatformID.Unix)
33                 return true;
34 
35             var permissions = NativeConvert.FromOctalPermissionString(mode.ToString());
36             return Syscall.chmod(file, permissions) == 0;
37         }
38 
ChangeFileOwner(string file, uint user, uint? group)39         public static bool ChangeFileOwner(string file, uint user, uint? group)
40         {
41             // Changing file owner is only supported on Unix platforms
42             if (Environment.OSVersion.Platform != PlatformID.Unix)
43                 return true;
44 
45             return Syscall.chown(file, user, group ?? unchecked((uint) -1)) == 0;
46         }
47 
GetGroupId(string groupName)48         public static uint? GetGroupId(string groupName)
49         {
50             // Group IDs are only supported on Unix platforms
51             if (Environment.OSVersion.Platform != PlatformID.Unix)
52                 return 0;
53 
54             var gr = Syscall.getgrnam(groupName);
55             return gr?.gr_gid;
56         }
57 
GetUserId(string userName)58         public static uint? GetUserId(string userName)
59         {
60             // User IDs are only supported on Unix platforms
61             if (Environment.OSVersion.Platform != PlatformID.Unix)
62                 return 0;
63 
64             var pw = Syscall.getpwnam(userName);
65             return pw?.pw_uid;
66         }
67 
SetUserId(uint userId)68         public static bool SetUserId(uint userId)
69         {
70             // Setting user ID is only supported on Unix platforms
71             if (Environment.OSVersion.Platform != PlatformID.Unix)
72                 return true;
73 
74             try
75             {
76                 Syscall.setuid(userId);
77             }
78             catch
79             {
80                 return false;
81             }
82 
83             return true;
84         }
85     }
86 }