1 /*
2  * Copyright (C) 2007 The Android Open Source Project
3  *
4  * Licensed under the Apache License, Version 2.0 (the "License");
5  * you may not use this file except in compliance with the License.
6  * You may obtain a copy of the License at
7  *
8  *      http://www.apache.org/licenses/LICENSE-2.0
9  *
10  * Unless required by applicable law or agreed to in writing, software
11  * distributed under the License is distributed on an "AS IS" BASIS,
12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13  * See the License for the specific language governing permissions and
14  * limitations under the License.
15  */
16 
17 package android.net;
18 
19 import java.io.IOException;
20 import java.io.FileDescriptor;
21 
22 /**
23  * Non-standard class for creating an inbound UNIX-domain socket
24  * in the Linux abstract namespace.
25  */
26 public class LocalServerSocket {
27     private final LocalSocketImpl impl;
28     private final LocalSocketAddress localAddress;
29 
30     /** 50 seems a bit much, but it's what was here */
31     private static final int LISTEN_BACKLOG = 50;
32 
33     /**
34      * Creates a new server socket listening at specified name.
35      * On the Android platform, the name is created in the Linux
36      * abstract namespace (instead of on the filesystem).
37      *
38      * @param name address for socket
39      * @throws IOException
40      */
LocalServerSocket(String name)41     public LocalServerSocket(String name) throws IOException
42     {
43         impl = new LocalSocketImpl();
44 
45         impl.create(LocalSocket.SOCKET_STREAM);
46 
47         localAddress = new LocalSocketAddress(name);
48         impl.bind(localAddress);
49 
50         impl.listen(LISTEN_BACKLOG);
51     }
52 
53     /**
54      * Create a LocalServerSocket from a file descriptor that's already
55      * been created and bound. listen() will be called immediately on it.
56      * Used for cases where file descriptors are passed in via environment
57      * variables
58      *
59      * @param fd bound file descriptor
60      * @throws IOException
61      */
LocalServerSocket(FileDescriptor fd)62     public LocalServerSocket(FileDescriptor fd) throws IOException
63     {
64         impl = new LocalSocketImpl(fd);
65         impl.listen(LISTEN_BACKLOG);
66         localAddress = impl.getSockAddress();
67     }
68 
69     /**
70      * Obtains the socket's local address
71      *
72      * @return local address
73      */
getLocalSocketAddress()74     public LocalSocketAddress getLocalSocketAddress()
75     {
76         return localAddress;
77     }
78 
79     /**
80      * Accepts a new connection to the socket. Blocks until a new
81      * connection arrives.
82      *
83      * @return a socket representing the new connection.
84      * @throws IOException
85      */
accept()86     public LocalSocket accept() throws IOException
87     {
88         LocalSocketImpl acceptedImpl = new LocalSocketImpl();
89 
90         impl.accept (acceptedImpl);
91 
92         return new LocalSocket(acceptedImpl, LocalSocket.SOCKET_UNKNOWN);
93     }
94 
95     /**
96      * Returns file descriptor or null if not yet open/already closed
97      *
98      * @return fd or null
99      */
getFileDescriptor()100     public FileDescriptor getFileDescriptor() {
101         return impl.getFileDescriptor();
102     }
103 
104     /**
105      * Closes server socket.
106      *
107      * @throws IOException
108      */
close()109     public void close() throws IOException
110     {
111         impl.close();
112     }
113 }
114