/*
* Copyright (C) 2009 The Android Open Source Project
* Copyright 2014 gitblit.com.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package com.gitblit.transport.ssh.commands;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.util.ArrayList;
import java.util.List;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;
import java.util.concurrent.Future;
import java.util.concurrent.ScheduledExecutorService;
import java.util.concurrent.atomic.AtomicBoolean;
import java.util.concurrent.atomic.AtomicReference;
import org.apache.sshd.server.Command;
import org.apache.sshd.server.CommandFactory;
import org.apache.sshd.server.Environment;
import org.apache.sshd.server.ExitCallback;
import org.apache.sshd.server.SessionAware;
import org.apache.sshd.server.session.ServerSession;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import com.gitblit.Keys;
import com.gitblit.manager.IGitblit;
import com.gitblit.transport.ssh.SshDaemonClient;
import com.gitblit.utils.WorkQueue;
import com.google.common.util.concurrent.Atomics;
import com.google.common.util.concurrent.ThreadFactoryBuilder;
public class SshCommandFactory implements CommandFactory {
private static final Logger logger = LoggerFactory.getLogger(SshCommandFactory.class);
private final WorkQueue workQueue;
private final IGitblit gitblit;
private final ScheduledExecutorService startExecutor;
private final ExecutorService destroyExecutor;
public SshCommandFactory(IGitblit gitblit, WorkQueue workQueue) {
this.gitblit = gitblit;
this.workQueue = workQueue;
int threads = gitblit.getSettings().getInteger(Keys.git.sshCommandStartThreads, 2);
startExecutor = workQueue.createQueue(threads, "SshCommandStart");
destroyExecutor = Executors.newSingleThreadExecutor(
new ThreadFactoryBuilder()
.setNameFormat("SshCommandDestroy-%s")
.setDaemon(true)
.build());
}
public void stop() {
destroyExecutor.shutdownNow();
}
public RootDispatcher createRootDispatcher(SshDaemonClient client, String commandLine) {
return new RootDispatcher(gitblit, client, commandLine, workQueue);
}
@Override
public Command createCommand(final String commandLine) {
return new Trampoline(commandLine);
}
private class Trampoline implements Command, SessionAware {
private final String[] argv;
private ServerSession session;
private InputStream in;
private OutputStream out;
private OutputStream err;
private ExitCallback exit;
private Environment env;
private String cmdLine;
private DispatchCommand cmd;
private final AtomicBoolean logged;
private final AtomicReference<Future<?>> task;
Trampoline(String line) {
if (line.startsWith("git-")) {
line = "git " + line;
}
cmdLine = line;
argv = split(line);
logged = new AtomicBoolean();
task = Atomics.newReference();
}
@Override
public void setSession(ServerSession session) {
this.session = session;
}
@Override
public void setInputStream(final InputStream in) {
this.in = in;
}
@Override
public void setOutputStream(final OutputStream out) {
this.out = out;
}
@Override
public void setErrorStream(final OutputStream err) {
this.err = err;
}
@Override
public void setExitCallback(final ExitCallback callback) {
this.exit = callback;
}
@Override
public void start(final Environment env) throws IOException {
this.env = env;
task.set(startExecutor.submit(new Runnable() {
@Override
public void run() {
try {
onStart();
} catch (Exception e) {
logger.warn("Cannot start command ", e);
}
}
@Override
public String toString() {
return "start (user " + session.getUsername() + ")";
}
}));
}
private void onStart() throws IOException {
synchronized (this) {
SshDaemonClient client = session.getAttribute(SshDaemonClient.KEY);
try {
cmd = createRootDispatcher(client, cmdLine);
cmd.setArguments(argv);
cmd.setInputStream(in);
cmd.setOutputStream(out);
cmd.setErrorStream(err);
cmd.setExitCallback(new ExitCallback() {
@Override
public void onExit(int rc, String exitMessage) {
exit.onExit(translateExit(rc), exitMessage);
log(rc);
}
@Override
public void onExit(int rc) {
exit.onExit(translateExit(rc));
log(rc);
}
});
cmd.start(env);
} finally {
client = null;
}
}
}
private int translateExit(final int rc) {
switch (rc) {
case BaseCommand.STATUS_NOT_ADMIN:
return 1;
case BaseCommand.STATUS_CANCEL:
return 15 /* SIGKILL */;
case BaseCommand.STATUS_NOT_FOUND:
return 127 /* POSIX not found */;
default:
return rc;
}
}
private void log(final int rc) {
if (logged.compareAndSet(false, true)) {
logger.info("onExecute: {} exits with: {}", cmd.getClass().getSimpleName(), rc);
}
}
@Override
public void destroy() {
Future<?> future = task.getAndSet(null);
if (future != null) {
future.cancel(true);
destroyExecutor.execute(new Runnable() {
@Override
public void run() {
onDestroy();
}
});
}
}
private void onDestroy() {
synchronized (this) {
if (cmd != null) {
try {
cmd.destroy();
} finally {
cmd = null;
}
}
}
}
}
/** Split a command line into a string array. */
static public String[] split(String commandLine) {
final List<String> list = new ArrayList<String>();
boolean inquote = false;
boolean inDblQuote = false;
StringBuilder r = new StringBuilder();
for (int ip = 0; ip < commandLine.length();) {
final char b = commandLine.charAt(ip++);
switch (b) {
case '\t':
case ' ':
if (inquote || inDblQuote)
r.append(b);
else if (r.length() > 0) {
list.add(r.toString());
r = new StringBuilder();
}
continue;
case '\"':
if (inquote)
r.append(b);
else
inDblQuote = !inDblQuote;
continue;
case '\'':
if (inDblQuote)
r.append(b);
else
inquote = !inquote;
continue;
case '\\':
if (inquote || ip == commandLine.length())
r.append(b); // literal within a quote
else
r.append(commandLine.charAt(ip++));
continue;
default:
r.append(b);
continue;
}
}
if (r.length() > 0) {
list.add(r.toString());
}
return list.toArray(new String[list.size()]);
}
}