1 /***
2   This file is part of avahi.
3 
4   avahi is free software; you can redistribute it and/or modify it
5   under the terms of the GNU Lesser General Public License as
6   published by the Free Software Foundation; either version 2.1 of the
7   License, or (at your option) any later version.
8 
9   avahi is distributed in the hope that it will be useful, but WITHOUT
10   ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
11   or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General
12   Public License for more details.
13 
14   You should have received a copy of the GNU Lesser General Public
15   License along with avahi; if not, write to the Free Software
16   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307
17   USA.
18 ***/
19 
20 using System;
21 using System.Net;
22 using System.Text;
23 using System.Runtime.InteropServices;
24 using Mono.Unix;
25 using Mono.Unix.Native;
26 
27 using Stdlib = Mono.Unix.Native.Stdlib;
28 
29 namespace Avahi
30 {
31     internal class Utility
32     {
33         [DllImport ("libc")]
strlen(IntPtr ptr)34         private static extern int strlen (IntPtr ptr);
35 
36         [DllImport ("avahi-common")]
avahi_address_snprint(IntPtr buf, int size, IntPtr address)37         private static extern IntPtr avahi_address_snprint (IntPtr buf, int size, IntPtr address);
38 
39         [DllImport ("avahi-common")]
avahi_address_parse(IntPtr str, Protocol proto, IntPtr ret)40         private static extern IntPtr avahi_address_parse (IntPtr str, Protocol proto, IntPtr ret);
41 
PtrToString(IntPtr ptr)42         public static string PtrToString (IntPtr ptr)
43         {
44             if (ptr == IntPtr.Zero)
45                 return null;
46 
47             int len = strlen (ptr);
48             byte[] bytes = new byte[len];
49             Marshal.Copy (ptr, bytes, 0, len);
50             return Encoding.UTF8.GetString (bytes);
51         }
52 
PtrToStringFree(IntPtr ptr)53         public static string PtrToStringFree (IntPtr ptr)
54         {
55             if (ptr == IntPtr.Zero)
56                 return null;
57 
58             string ret = PtrToString (ptr);
59             Free (ptr);
60             return ret;
61         }
62 
StringToBytes(string str)63         public static byte[] StringToBytes (string str)
64         {
65             if (str == null)
66                 return null;
67 
68             return Encoding.UTF8.GetBytes (str + "\0"); // lame.
69         }
70 
StringToPtr(string str)71         private static IntPtr StringToPtr (string str)
72         {
73             if (str == null)
74                 return IntPtr.Zero;
75 
76             byte[] bytes = Utility.StringToBytes (str);
77             IntPtr buf = Stdlib.malloc ((uint) bytes.Length + 1);
78             Marshal.Copy (bytes, 0, buf, bytes.Length);
79             Marshal.WriteByte (buf, bytes.Length, 0);
80             return buf;
81         }
82 
Free(IntPtr ptr)83         public static void Free (IntPtr ptr)
84         {
85             Stdlib.free (ptr);
86         }
87 
AddressToPtr(IPAddress address)88         public static IntPtr AddressToPtr (IPAddress address)
89         {
90             IntPtr straddr = Utility.StringToPtr (address.ToString ());
91             IntPtr addrPtr = Stdlib.malloc (32);
92             avahi_address_parse (straddr, Protocol.Unspecified, addrPtr);
93             Utility.Free (straddr);
94 
95             return addrPtr;
96         }
97 
PtrToAddress(IntPtr ptr)98         public static IPAddress PtrToAddress (IntPtr ptr)
99         {
100             IPAddress address = null;
101 
102             if (ptr != IntPtr.Zero) {
103                 IntPtr buf = Stdlib.malloc (256);
104                 IntPtr addrPtr = avahi_address_snprint (buf, 256, ptr);
105                 address = IPAddress.Parse (Utility.PtrToString (addrPtr));
106                 Utility.Free (addrPtr);
107             }
108 
109             return address;
110         }
111     }
112 }
113