1 /*
2 * Copyright (C) 2018, Thomas Wolf <thomas.wolf@paranor.ch>
3 * and other copyright owners as documented in the project's IP log.
4 *
5 * This program and the accompanying materials are made available
6 * under the terms of the Eclipse Distribution License v1.0 which
7 * accompanies this distribution, is reproduced below, and is
8 * available at http://www.eclipse.org/org/documents/edl-v10.php
9 *
10 * All rights reserved.
11 *
12 * Redistribution and use in source and binary forms, with or
13 * without modification, are permitted provided that the following
14 * conditions are met:
15 *
16 * - Redistributions of source code must retain the above copyright
17 * notice, this list of conditions and the following disclaimer.
18 *
19 * - Redistributions in binary form must reproduce the above
20 * copyright notice, this list of conditions and the following
21 * disclaimer in the documentation and/or other materials provided
22 * with the distribution.
23 *
24 * - Neither the name of the Eclipse Foundation, Inc. nor the
25 * names of its contributors may be used to endorse or promote
26 * products derived from this software without specific prior
27 * written permission.
28 *
29 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND
30 * CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES,
31 * INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
32 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
33 * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR
34 * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
35 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
36 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
37 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
38 * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
39 * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
40 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
41 * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
42 */
43 package org.eclipse.jgit.internal.transport.sshd.proxy;
44
45 import java.net.InetSocketAddress;
46 import java.util.ArrayList;
47 import java.util.Arrays;
48 import java.util.List;
49 import java.util.concurrent.Callable;
50 import java.util.concurrent.TimeUnit;
51 import java.util.concurrent.atomic.AtomicReference;
52
53 import org.apache.sshd.client.session.ClientSession;
54 import org.eclipse.jgit.annotations.NonNull;
55 import org.eclipse.jgit.internal.transport.sshd.JGitClientSession;
56
57 /**
58 * Basic common functionality for a {@link StatefulProxyConnector}.
59 */
60 public abstract class AbstractClientProxyConnector
61 implements StatefulProxyConnector {
62
63 private static final long DEFAULT_PROXY_TIMEOUT_MILLIS = TimeUnit.SECONDS
64 .toMillis(30L);
65
66 /** Guards {@link #done} and {@link #bufferedCommands}. */
67 private Object lock = new Object();
68
69 private boolean done;
70
71 private List<Callable<Void>> bufferedCommands = new ArrayList<>();
72
73 private AtomicReference<Runnable> unregister = new AtomicReference<>();
74
75 private long remainingProxyProtocolTime = DEFAULT_PROXY_TIMEOUT_MILLIS;
76
77 private long lastProxyOperationTime = 0L;
78
79 /** The ultimate remote address to connect to. */
80 protected final InetSocketAddress remoteAddress;
81
82 /** The proxy address. */
83 protected final InetSocketAddress proxyAddress;
84
85 /** The user to authenticate at the proxy with. */
86 protected String proxyUser;
87
88 /** The password to use for authentication at the proxy. */
89 protected char[] proxyPassword;
90
91 /**
92 * Creates a new {@link AbstractClientProxyConnector}.
93 *
94 * @param proxyAddress
95 * of the proxy server we're connecting to
96 * @param remoteAddress
97 * of the target server to connect to
98 * @param proxyUser
99 * to authenticate at the proxy with; may be {@code null}
100 * @param proxyPassword
101 * to authenticate at the proxy with; may be {@code null}
102 */
103 public AbstractClientProxyConnector(@NonNull InetSocketAddress proxyAddress,
104 @NonNull InetSocketAddress remoteAddress, String proxyUser,
105 char[] proxyPassword) {
106 this.proxyAddress = proxyAddress;
107 this.remoteAddress = remoteAddress;
108 this.proxyUser = proxyUser;
109 this.proxyPassword = proxyPassword == null ? new char[0]
110 : proxyPassword;
111 }
112
113 /**
114 * Initializes this instance. Installs itself as proxy handler on the
115 * session.
116 *
117 * @param session
118 * to initialize for
119 */
120 protected void init(ClientSession session) {
121 remainingProxyProtocolTime = session.getLongProperty(
122 StatefulProxyConnector.TIMEOUT_PROPERTY,
123 DEFAULT_PROXY_TIMEOUT_MILLIS);
124 if (remainingProxyProtocolTime <= 0L) {
125 remainingProxyProtocolTime = DEFAULT_PROXY_TIMEOUT_MILLIS;
126 }
127 if (session instanceof JGitClientSession) {
128 JGitClientSession s = (JGitClientSession) session;
129 unregister.set(() -> s.setProxyHandler(null));
130 s.setProxyHandler(this);
131 } else {
132 // Internal error, no translation
133 throw new IllegalStateException(
134 "Not a JGit session: " + session.getClass().getName()); //$NON-NLS-1$
135 }
136 }
137
138 /**
139 * Obtains the timeout for the whole rest of the proxy connection protocol.
140 *
141 * @return the timeout in milliseconds, always > 0L
142 */
143 protected long getTimeout() {
144 long last = lastProxyOperationTime;
145 long now = System.nanoTime();
146 lastProxyOperationTime = now;
147 long remaining = remainingProxyProtocolTime;
148 if (last != 0L) {
149 long elapsed = now - last;
150 remaining -= elapsed;
151 if (remaining < 0L) {
152 remaining = 10L; // Give it grace period.
153 }
154 }
155 remainingProxyProtocolTime = remaining;
156 return remaining;
157 }
158
159 /**
160 * Adjusts the timeout calculation to not account of elapsed time since the
161 * last time the timeout was gotten. Can be used for instance to ignore time
162 * spent in user dialogs be counted against the overall proxy connection
163 * protocol timeout.
164 */
165 protected void adjustTimeout() {
166 lastProxyOperationTime = System.nanoTime();
167 }
168
169 /**
170 * Sets the "done" flag.
171 *
172 * @param success
173 * whether the connector terminated successfully.
174 * @throws Exception
175 * if starting ssh fails
176 */
177 protected void setDone(boolean success) throws Exception {
178 List<Callable<Void>> buffered;
179 Runnable unset = unregister.getAndSet(null);
180 if (unset != null) {
181 unset.run();
182 }
183 synchronized (lock) {
184 done = true;
185 buffered = bufferedCommands;
186 bufferedCommands = null;
187 }
188 if (success && buffered != null) {
189 for (Callable<Void> starter : buffered) {
190 starter.call();
191 }
192 }
193 }
194
195 @Override
196 public void runWhenDone(Callable<Void> starter) throws Exception {
197 synchronized (lock) {
198 if (!done) {
199 bufferedCommands.add(starter);
200 return;
201 }
202 }
203 starter.call();
204 }
205
206 /**
207 * Clears the proxy password.
208 */
209 protected void clearPassword() {
210 Arrays.fill(proxyPassword, '\000');
211 proxyPassword = new char[0];
212 }
213 }