Java tutorial
/* * Copyright 2015 Open Networking Laboratory * * 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 org.onosproject.provider.netconf.device.impl; import static com.google.common.base.Preconditions.checkNotNull; import static org.onlab.util.Tools.delay; import static org.slf4j.LoggerFactory.getLogger; import java.io.IOException; import java.io.StringReader; import java.util.ArrayList; import java.util.List; import org.jdom2.Document; import org.jdom2.Element; import org.jdom2.input.SAXBuilder; import org.jdom2.output.Format; import org.jdom2.output.XMLOutputter; import org.slf4j.Logger; import com.tailf.jnc.Capabilities; import com.tailf.jnc.JNCException; import com.tailf.jnc.SSHConnection; import com.tailf.jnc.SSHSession; /** * This is a logical representation of actual NETCONF device, carrying all the * necessary information to connect and execute NETCONF operations. */ public class NetconfDevice { private final Logger log = getLogger(NetconfDevice.class); /** * The Device State is used to determine whether the device is active or * inactive. This state infomation will help Device Creator to add or delete * the device from the core. */ public enum DeviceState { /* Used to specify Active state of the device */ ACTIVE, /* Used to specify inactive state of the device */ INACTIVE, /* Used to specify invalid state of the device */ INVALID } private static final int DEFAULT_SSH_PORT = 22; private static final int DEFAULT_CON_TIMEOUT = 0; private static final String XML_CAPABILITY_KEY = "capability"; private static final int EVENTINTERVAL = 2000; private static final int CONNECTION_CHECK_INTERVAL = 3; private static final String INPUT_HELLO_XML_MSG = new StringBuilder( "<?xml version=\"1.0\" encoding=\"UTF-8\"?>") .append("<hello xmlns=\"urn:ietf:params:xml:ns:netconf:base:1.0\">") .append("<capabilities><capability>urn:ietf:params:netconf:base:1.0</capability>") .append("</capabilities></hello>").toString(); private String sshHost; private int sshPort = DEFAULT_SSH_PORT; private int connectTimeout = DEFAULT_CON_TIMEOUT; private String username; private String password; private boolean reachable = false; private List<String> capabilities = new ArrayList<String>(); private SSHConnection sshConnection = null; private DeviceState deviceState = DeviceState.INVALID; protected NetconfDevice(String sshHost, int sshPort, String username, String password) { this.username = checkNotNull(username, "Netconf Username Cannot be null"); this.sshHost = checkNotNull(sshHost, "Netconf Device IP cannot be null"); this.sshPort = checkNotNull(sshPort, "Netconf Device SSH port cannot be null"); this.password = password; } /** * This will try to connect to NETCONF device and find all the capabilities. * * @throws Exception if unable to connect to the device */ // FIXME: this should not be a generic Exception; perhaps wrap in some RuntimeException public void init() throws Exception { try { if (sshConnection == null) { sshConnection = new SSHConnection(sshHost, sshPort, connectTimeout); sshConnection.authenticateWithPassword(username, password); } // Send hello message to retrieve capabilities. } catch (IOException e) { log.error("Fatal Error while creating connection to the device: " + deviceInfo(), e); throw e; } catch (JNCException e) { log.error("Failed to connect to the device: " + deviceInfo(), e); throw e; } hello(); } private void hello() { SSHSession ssh = null; try { ssh = new SSHSession(sshConnection); String helloRequestXML = INPUT_HELLO_XML_MSG.trim(); log.debug("++++++++++++++++++++++++++++++++++Sending Hello: " + sshConnection.getGanymedConnection().getHostname() + "++++++++++++++++++++++++++++++++++"); printPrettyXML(helloRequestXML); ssh.print(helloRequestXML); // ssh.print(endCharSeq); ssh.flush(); String xmlResponse = null; int i = CONNECTION_CHECK_INTERVAL; while (!ssh.ready() && i > 0) { delay(EVENTINTERVAL); i--; } if (ssh.ready()) { StringBuffer readOne = ssh.readOne(); if (readOne == null) { log.error("The Hello Contains No Capabilites"); throw new JNCException(JNCException.SESSION_ERROR, "server does not support NETCONF base capability: " + Capabilities.NETCONF_BASE_CAPABILITY); } else { xmlResponse = readOne.toString().trim(); log.debug("++++++++++++++++++++++++++++++++++Reading Capabilities: " + sshConnection.getGanymedConnection().getHostname() + "++++++++++++++++++++++++++++++++++"); printPrettyXML(xmlResponse); processCapabilities(xmlResponse); } } reachable = true; } catch (IOException e) { log.error("Fatal Error while sending Hello Message to the device: " + deviceInfo(), e); } catch (JNCException e) { log.error("Fatal Error while sending Hello Message to the device: " + deviceInfo(), e); } finally { log.debug("Closing the session after successful execution"); if (ssh != null) { ssh.close(); } } } private void processCapabilities(String xmlResponse) throws JNCException { if (xmlResponse.isEmpty()) { log.error("The capability response cannot be empty"); throw new JNCException(JNCException.SESSION_ERROR, "server does not support NETCONF base capability: " + Capabilities.NETCONF_BASE_CAPABILITY); } try { Document doc = new SAXBuilder().build(new StringReader(xmlResponse)); Element rootElement = doc.getRootElement(); processCapabilities(rootElement); } catch (Exception e) { log.error("ERROR while parsing the XML " + xmlResponse); } } private void processCapabilities(Element rootElement) { List<Element> children = rootElement.getChildren(); if (children.isEmpty()) { return; } for (Element child : children) { if (child.getName().equals(XML_CAPABILITY_KEY)) { capabilities.add(child.getValue()); } if (!child.getChildren().isEmpty()) { processCapabilities(child); } } } private void printPrettyXML(String xmlstring) { try { Document doc = new SAXBuilder().build(new StringReader(xmlstring)); XMLOutputter xmOut = new XMLOutputter(Format.getPrettyFormat()); String outputString = xmOut.outputString(doc); log.debug(outputString); } catch (Exception e) { log.error("ERROR while parsing the XML " + xmlstring, e); } } /** * This would return host IP and host Port, used by this particular Netconf * Device. * @return Device Information. */ public String deviceInfo() { return new StringBuilder("host: ").append(sshHost).append(". port: ").append(sshPort).toString(); } /** * This will terminate the device connection. */ public void disconnect() { sshConnection.close(); reachable = false; } /** * This will list down all the capabilities supported on the device. * @return Capability list. */ public List<String> getCapabilities() { return capabilities; } /** * This api is intended to know whether the device is connected or not. * @return true if connected */ public boolean isReachable() { return reachable; } /** * This will return the IP used connect ssh on the device. * @return Netconf Device IP */ public String getSshHost() { return sshHost; } /** * This will return the SSH Port used connect the device. * @return SSH Port number */ public int getSshPort() { return sshPort; } /** * The usename used to connect Netconf Device. * @return Device Username */ public String getUsername() { return username; } /** * Retrieve current state of the device. * @return Current Device State */ public DeviceState getDeviceState() { return deviceState; } /** * This is set the state information for the device. * @param deviceState Next Device State */ public void setDeviceState(DeviceState deviceState) { this.deviceState = deviceState; } /** * Check whether the device is in Active state. * @return true if the device is Active */ public boolean isActive() { return deviceState == DeviceState.ACTIVE ? true : false; } public void setConnectTimeout(int connectTimeout) { this.connectTimeout = connectTimeout; } }