//
// Licensed to the Apache Software Foundation (ASF) under one
// or more contributor license agreements. See the NOTICE file
// distributed with this work for additional information
// regarding copyright ownership. The ASF licenses this file
// to you 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.cloud.utils.ssh;
import java.io.IOException;
import java.io.InputStream;
import org.apache.log4j.Logger;
import com.trilead.ssh2.ChannelCondition;
import com.trilead.ssh2.Session;
public class SSHCmdHelper {
private static final Logger s_logger = Logger.getLogger(SSHCmdHelper.class);
private static final int DEFAULT_CONNECT_TIMEOUT = 180000;
private static final int DEFAULT_KEX_TIMEOUT = 60000;
public static com.trilead.ssh2.Connection acquireAuthorizedConnection(String ip, String username, String password) {
return acquireAuthorizedConnection(ip, 22, username, password);
}
public static com.trilead.ssh2.Connection acquireAuthorizedConnection(String ip, int port, String username, String password) {
com.trilead.ssh2.Connection sshConnection = new com.trilead.ssh2.Connection(ip, port);
try {
sshConnection.connect(null, DEFAULT_CONNECT_TIMEOUT, DEFAULT_KEX_TIMEOUT);
if (!sshConnection.authenticateWithPassword(username, password)) {
String[] methods = sshConnection.getRemainingAuthMethods(username);
StringBuffer mStr = new StringBuffer();
for (int i = 0; i < methods.length; i++) {
mStr.append(methods[i]);
}
s_logger.warn("SSH authorizes failed, support authorized methods are " + mStr);
return null;
}
return sshConnection;
} catch (IOException e) {
s_logger.warn("Get SSH connection failed", e);
return null;
}
}
public static void releaseSshConnection(com.trilead.ssh2.Connection sshConnection) {
if (sshConnection != null) {
sshConnection.close();
}
}
public static boolean sshExecuteCmd(com.trilead.ssh2.Connection sshConnection, String cmd, int nTimes) {
for (int i = 0; i < nTimes; i++) {
try {
if (sshExecuteCmdOneShot(sshConnection, cmd))
return true;
} catch (SshException e) {
continue;
}
}
return false;
}
public static int sshExecuteCmdWithExitCode(com.trilead.ssh2.Connection sshConnection, String cmd) {
return sshExecuteCmdWithExitCode(sshConnection, cmd, 3);
}
public static int sshExecuteCmdWithExitCode(com.trilead.ssh2.Connection sshConnection, String cmd, int nTimes) {
for (int i = 0; i < nTimes; i++) {
try {
return sshExecuteCmdOneShotWithExitCode(sshConnection, cmd);
} catch (SshException e) {
continue;
}
}
return -1;
}
public static boolean sshExecuteCmd(com.trilead.ssh2.Connection sshConnection, String cmd) {
return sshExecuteCmd(sshConnection, cmd, 3);
}
public static int sshExecuteCmdOneShotWithExitCode(com.trilead.ssh2.Connection sshConnection, String cmd) throws SshException {
s_logger.debug("Executing cmd: " + cmd);
Session sshSession = null;
try {
sshSession = sshConnection.openSession();
// There is a bug in Trilead library, wait a second before
// starting a shell and executing commands, from http://spci.st.ewi.tudelft.nl/chiron/xref/nl/tudelft/swerl/util/SSHConnection.html
Thread.sleep(1000);
if (sshSession == null) {
throw new SshException("Cannot open ssh session");
}
sshSession.execCommand(cmd);
InputStream stdout = sshSession.getStdout();
InputStream stderr = sshSession.getStderr();
byte[] buffer = new byte[8192];
StringBuffer sbResult = new StringBuffer();
int currentReadBytes = 0;
while (true) {
if (stdout == null || stderr == null) {
throw new SshException("stdout or stderr of ssh session is null");
}
if ((stdout.available() == 0) && (stderr.available() == 0)) {
int conditions = sshSession.waitForCondition(ChannelCondition.STDOUT_DATA
| ChannelCondition.STDERR_DATA | ChannelCondition.EOF | ChannelCondition.EXIT_STATUS,
120000);
if ((conditions & ChannelCondition.TIMEOUT) != 0) {
String msg = "Timed out in waiting SSH execution result";
s_logger.error(msg);
throw new Exception(msg);
}
if ((conditions & ChannelCondition.EXIT_STATUS) != 0) {
if ((conditions & (ChannelCondition.STDOUT_DATA | ChannelCondition.STDERR_DATA)) == 0) {
break;
}
}
if ((conditions & ChannelCondition.EOF) != 0) {
if ((conditions & (ChannelCondition.STDOUT_DATA | ChannelCondition.STDERR_DATA)) == 0) {
break;
}
}
}
while (stdout.available() > 0) {
currentReadBytes = stdout.read(buffer);
sbResult.append(new String(buffer, 0, currentReadBytes));
}
while (stderr.available() > 0) {
currentReadBytes = stderr.read(buffer);
sbResult.append(new String(buffer, 0, currentReadBytes));
}
}
String result = sbResult.toString();
if (result != null && !result.isEmpty())
s_logger.debug(cmd + " output:" + result);
// exit status delivery might get delayed
for(int i = 0 ; i<10 ; i++ ) {
Integer status = sshSession.getExitStatus();
if( status != null ) {
return status;
}
Thread.sleep(100);
}
return -1;
} catch (Exception e) {
s_logger.debug("Ssh executed failed", e);
throw new SshException("Ssh executed failed " + e.getMessage());
} finally {
if (sshSession != null)
sshSession.close();
}
}
public static boolean sshExecuteCmdOneShot(com.trilead.ssh2.Connection sshConnection, String cmd) throws SshException {
return sshExecuteCmdOneShotWithExitCode(sshConnection, cmd) == 0;
}
}