1 /*
2 * Copyright (C) 2008, Robin Rosenberg <robin.rosenberg@dewire.com>
3 * Copyright (C) 2008, Shawn O. Pearce <spearce@spearce.org>
4 * and other copyright owners as documented in the project's IP log.
5 *
6 * This program and the accompanying materials are made available
7 * under the terms of the Eclipse Distribution License v1.0 which
8 * accompanies this distribution, is reproduced below, and is
9 * available at http://www.eclipse.org/org/documents/edl-v10.php
10 *
11 * All rights reserved.
12 *
13 * Redistribution and use in source and binary forms, with or
14 * without modification, are permitted provided that the following
15 * conditions are met:
16 *
17 * - Redistributions of source code must retain the above copyright
18 * notice, this list of conditions and the following disclaimer.
19 *
20 * - Redistributions in binary form must reproduce the above
21 * copyright notice, this list of conditions and the following
22 * disclaimer in the documentation and/or other materials provided
23 * with the distribution.
24 *
25 * - Neither the name of the Eclipse Foundation, Inc. nor the
26 * names of its contributors may be used to endorse or promote
27 * products derived from this software without specific prior
28 * written permission.
29 *
30 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND
31 * CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES,
32 * INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
33 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
34 * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR
35 * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
36 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
37 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
38 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
39 * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
40 * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
41 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
42 * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
43 */
44
45 package org.eclipse.jgit.transport;
46
47 import org.eclipse.jgit.errors.TransportException;
48 import org.eclipse.jgit.util.FS;
49
50 /**
51 * Creates and destroys SSH connections to a remote system.
52 * <p>
53 * Different implementations of the session factory may be used to control
54 * communicating with the end-user as well as reading their personal SSH
55 * configuration settings, such as known hosts and private keys.
56 * <p>
57 * A {@link org.eclipse.jgit.transport.RemoteSession} must be returned to the
58 * factory that created it. Callers are encouraged to retain the
59 * SshSessionFactory for the duration of the period they are using the Session.
60 */
61 public abstract class SshSessionFactory {
62 private static SshSessionFactory INSTANCE = new DefaultSshSessionFactory();
63
64 /**
65 * Get the currently configured JVM-wide factory.
66 * <p>
67 * A factory is always available. By default the factory will read from the
68 * user's <code>$HOME/.ssh</code> and assume OpenSSH compatibility.
69 *
70 * @return factory the current factory for this JVM.
71 */
72 public static SshSessionFactory getInstance() {
73 return INSTANCE;
74 }
75
76 /**
77 * Change the JVM-wide factory to a different implementation.
78 *
79 * @param newFactory
80 * factory for future sessions to be created through. If null the
81 * default factory will be restored.s
82 */
83 public static void setInstance(final SshSessionFactory newFactory) {
84 if (newFactory != null)
85 INSTANCE = newFactory;
86 else
87 INSTANCE = new DefaultSshSessionFactory();
88 }
89
90 /**
91 * Open (or reuse) a session to a host.
92 * <p>
93 * A reasonable UserInfo that can interact with the end-user (if necessary)
94 * is installed on the returned session by this method.
95 * <p>
96 * The caller must connect the session by invoking <code>connect()</code>
97 * if it has not already been connected.
98 *
99 * @param uri
100 * URI information about the remote host
101 * @param credentialsProvider
102 * provider to support authentication, may be null.
103 * @param fs
104 * the file system abstraction which will be necessary to
105 * perform certain file system operations.
106 * @param tms
107 * Timeout value, in milliseconds.
108 * @return a session that can contact the remote host.
109 * @throws org.eclipse.jgit.errors.TransportException
110 * the session could not be created.
111 */
112 public abstract RemoteSession getSession(URIish uri,
113 CredentialsProvider credentialsProvider, FS fs, int tms)
114 throws TransportException;
115
116 /**
117 * Close (or recycle) a session to a host.
118 *
119 * @param session
120 * a session previously obtained from this factory's
121 * {@link #getSession(URIish, CredentialsProvider, FS, int)}
122 * method.
123 */
124 public void releaseSession(final RemoteSession session) {
125 session.disconnect();
126 }
127 }