/*
* The MIT License
*
* Copyright 2011 Sony Ericsson Mobile Communications. All rights reserved.
*
* Permission is hereby granted, free of charge, to any person obtaining a copy
* of this software and associated documentation files (the "Software"), to deal
* in the Software without restriction, including without limitation the rights
* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
* copies of the Software, and to permit persons to whom the Software is
* furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included in
* all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
* THE SOFTWARE.
*/
package com.sonyericsson.hudson.plugins.gerrit.gerritevents.ssh;
import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.Reader;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import com.jcraft.jsch.Channel;
import com.jcraft.jsch.ChannelExec;
import com.jcraft.jsch.HostKey;
import com.jcraft.jsch.HostKeyRepository;
import com.jcraft.jsch.JSch;
import com.jcraft.jsch.JSchException;
import com.jcraft.jsch.Session;
import com.jcraft.jsch.UserInfo;
/**
* A simple ssh client connection with private key.
*
* @author Robert Sandell <robert.sandell@sonyericsson.com>
*/
public class SshConnectionImpl implements SshConnection {
private static final Logger logger = LoggerFactory.getLogger(SshConnectionImpl.class);
/**
* Keep-alive interval [msec]
*/
private static final int ALIVE_INTERVAL = 30 * 1000;
/**
* SSH Command to open an "exec channel".
*/
protected static final String CMD_EXEC = "exec";
private final JSch client;
private Session connectSession;
private Channel currentSession;
//CS IGNORE RedundantThrows FOR NEXT 12 LINES. REASON: Informative
/**
* Creates and opens a SshConnection.
*
* @param host the host to connect to.
* @param port the port.
* @param authentication the authentication-info
* @throws SshException if something happens - usually due to bad config.
* @throws IOException if the unfortunate happens.
*/
protected SshConnectionImpl(String host, int port, Authentication authentication) throws SshException, IOException {
logger.debug("connecting...");
try {
client = new JSch();
client.addIdentity(authentication.getPrivateKeyFile().getAbsolutePath(),
authentication.getPrivateKeyFilePassword());
client.setHostKeyRepository(new BlindHostKeyRepository());
connectSession = client.getSession(authentication.getUsername(), host, port);
connectSession.connect();
logger.debug("Connected: {}", connectSession.isConnected());
connectSession.setServerAliveInterval(ALIVE_INTERVAL);
} catch (JSchException ex) {
throw new SshException(ex);
}
}
/**
* Is the connection connected.
*
* @return true if it is so.
*/
@Override
public synchronized boolean isConnected() {
//Cannot distinguish connected or authenticated with the "new" API
return isAuthenticated();
}
/**
* Is the connection authenticated.
*
* @return true if it is so.
*/
@Override
public synchronized boolean isAuthenticated() {
return client != null && connectSession != null && connectSession.isConnected();
}
/**
* Returns if there already is an open session on this connection.
*
* @return true if it is so.
*/
@Override
public synchronized boolean isSessionOpen() {
return currentSession != null && currentSession.isConnected() && !currentSession.isEOF();
}
/**
* Execute an ssh command on the server.
* After the command is sent the used channel is disconnected.
*
* @param command the command to execute.
* @return a String containing the output from the command.
* @throws SshException if so.
*/
@Override
public synchronized String executeCommand(String command) throws SshException {
if (!isConnected()) {
throw new IllegalStateException("Not connected!");
}
try {
logger.debug("Opening channel");
Channel channel = connectSession.openChannel(CMD_EXEC);
((ChannelExec)channel).setCommand(command);
BufferedReader bufferedReader = new BufferedReader(new InputStreamReader(channel.getInputStream()));
logger.debug("connecting channel.");
channel.connect();
// Seems like Gerrit does not like when you disconnect directly after the command has been sent.
// For instance, we have seen effects of mails not being sent out. This is the reason for
// receiving all the incoming data.
String incomingLine = null;
StringBuilder commandOutput = new StringBuilder();
while ((incomingLine = bufferedReader.readLine()) != null) {
commandOutput.append(incomingLine);
commandOutput.append('\n');
logger.trace("Incoming line: {}", incomingLine);
}
logger.trace("Closing reader.");
bufferedReader.close();
logger.trace("disconnecting channel.");
channel.disconnect();
return commandOutput.toString();
} catch (JSchException ex) {
throw new SshException(ex);
} catch (IOException ex) {
throw new SshException(ex);
}
}
//CS IGNORE RedundantThrows FOR NEXT 14 LINES. REASON: Informative.
/**
* Execute an ssh command on the server, without closing the session
* so that a Reader can be returned with streaming data from the server.
*
* @param command the command to execute.
* @return a Reader with streaming data from the server.
* @throws IOException if it is so.
* @throws SshException if there are any ssh problems.
*/
@Override
public synchronized Reader executeCommandReader(String command) throws SshException, IOException {
if (!isConnected()) {
throw new IllegalStateException("Not connected!");
}
try {
Channel channel = connectSession.openChannel("exec");
((ChannelExec)channel).setCommand(command);
InputStreamReader reader = new InputStreamReader(channel.getInputStream());
channel.connect();
return reader;
} catch (JSchException ex) {
throw new SshException(ex);
}
}
//CS IGNORE RedundantThrows FOR NEXT 15 LINES. REASON: Informative.
/**
* This version takes a command to run, and then returns a wrapper instance
* that exposes all the standard state of the channel (stdin, stdout,
* stderr, exit status, etc).
*
* @param command the command to execute.
* @return a Channel with access to all streams and the exit code.
* @throws IOException if it is so.
* @throws SshException if there are any ssh problems.
* @see #executeCommandReader(String)
*/
@Override
public synchronized ChannelExec executeCommandChannel(String command) throws SshException, IOException {
if (!isConnected()) {
throw new IllegalStateException("Not connected!");
}
try {
ChannelExec channel = (ChannelExec)connectSession.openChannel("exec");
channel.setCommand(command);
channel.connect();
return channel;
} catch (JSchException ex) {
throw new SshException(ex);
}
}
/**
* Disconnects the connection.
*/
@Override
public synchronized void disconnect() {
if (isSessionOpen()) {
logger.debug("Closing ssh session.");
currentSession.disconnect();
currentSession = null;
}
if (isConnected()) {
logger.debug("Disconnecting client connection.");
connectSession.disconnect();
connectSession = null;
}
}
/**
* A KnownHosts repository that blindly exepts any host fingerprint as OK.
*/
static class BlindHostKeyRepository implements HostKeyRepository {
private static final HostKey[] EMPTY = new HostKey[0];
@Override
public int check(String host, byte[] key) {
return HostKeyRepository.OK;
}
@Override
public void add(HostKey hostkey, UserInfo ui) {
}
@Override
public void remove(String host, String type) {
}
@Override
public void remove(String host, String type, byte[] key) {
}
@Override
public String getKnownHostsRepositoryID() {
return "";
}
@Override
public HostKey[] getHostKey() {
return EMPTY;
}
@Override
public HostKey[] getHostKey(String host, String type) {
return EMPTY;
}
}
}