CORD-524 Added utils to execute IP commands to a remote host

Change-Id: Ie437f760a1d426cc748a7eae4ca1f5a2a1f104f5

+<?xml version="1.0" encoding="UTF-8"?>
+<!--
+  ~ Copyright 2016 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.
+  -->
+<app name="org.onosproject.cordvtn" origin="ON.Lab" version="${project.version}"
+        category="default" url="http://onosproject.org"
+        featuresRepo="mvn:${project.groupId}/${project.artifactId}/${project.version}/xml/features"
+        features="${project.artifactId}"
+        apps="org.onosproject.ovsdb-base,org.onosproject.openstackswitching,org.onosproject.dhcp">
+    <description>${project.description}</description>
+    <artifact>mvn:${project.groupId}/onos-app-cordvtn/${project.version}</artifact>
+</app>

+<?xml version="1.0" encoding="UTF-8" standalone="yes"?>
+<!--
+  ~ Copyright 2016 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.
+  -->
+<features xmlns="http://karaf.apache.org/xmlns/features/v1.2.0" name="${project.artifactId}-${project.version}">
+    <feature name="${project.artifactId}" version="${project.version}" description="${project.description}">
+        <feature>onos-api</feature>
+        <bundle>mvn:${project.groupId}/onos-app-cordvtn/${project.version}</bundle>
+        <bundle>wrap:mvn:com.jcraft/jsch/0.1.53$Bundle-SymbolicName=jsch&amp;Bundle-Version=0.1.53</bundle>
+    </feature>
+</features>

@@ -43,11 +43,6 @@
             APIs for interacting with the CORD VTN application.
         </api.description>
         <api.package>org.onosproject.cordvtn.rest</api.package>
-        <onos.app.requires>
-            org.onosproject.ovsdb-base,
-            org.onosproject.openstackswitching,
-            org.onosproject.dhcp
-        </onos.app.requires>
     </properties>
 
     <dependencies>
@@ -116,6 +111,11 @@
             <artifactId>onos-app-dhcp-api</artifactId>
             <version>${project.version}</version>
         </dependency>
+        <dependency>
+            <groupId>com.jcraft</groupId>
+            <artifactId>jsch</artifactId>
+            <version>0.1.53</version>
+        </dependency>
     </dependencies>
 
     <build>
@@ -145,6 +145,7 @@
                             com.fasterxml.jackson.databind,
                             com.fasterxml.jackson.databind.node,
                             com.fasterxml.jackson.core,
+                            com.jcraft.jsch,
                             org.apache.karaf.shell.commands,
                             org.apache.karaf.shell.console,
                             com.google.common.*,

+/*
+ * Copyright 2016 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.cordvtn;
+
+import com.google.common.collect.Sets;
+import com.google.common.io.CharStreams;
+import com.jcraft.jsch.Channel;
+import com.jcraft.jsch.ChannelExec;
+import com.jcraft.jsch.JSch;
+import com.jcraft.jsch.JSchException;
+import com.jcraft.jsch.Session;
+import org.onlab.packet.IpPrefix;
+import org.slf4j.Logger;
+
+import java.io.IOException;
+import java.io.InputStream;
+import java.io.InputStreamReader;
+import java.util.Set;
+import java.util.regex.Pattern;
+import java.util.stream.Collectors;
+
+import static org.slf4j.LoggerFactory.getLogger;
+
+/**
+ * {@code RemoteIpCommandUtil} provides methods to help execute Linux IP commands to a remote server.
+ * It opens individual exec channels for each command. User can create a session with {@code connect}
+ * method and then execute a series commands. After done with all commands, the session must be closed
+ * explicitly by calling {@code disconnect}.
+ */
+public final class RemoteIpCommandUtil {
+
+    protected static final Logger log = getLogger(RemoteIpCommandUtil.class);
+
+    private static final String STRICT_HOST_CHECKING = "StrictHostKeyChecking";
+    private static final String DEFAULT_STRICT_HOST_CHECKING = "no";
+    private static final int DEFAULT_SESSION_TIMEOUT = 60000; // milliseconds
+
+    private static final String IP_PATTERN = "^(([0-9]|[1-9][0-9]|1[0-9]{2}|2[0-4][0-9]|25[0-5])\\.)" +
+            "{3}([0-9]|[1-9][0-9]|1[0-9]{2}|2[0-4][0-9]|25[0-5])(\\/([0-9]|[1-2][0-9]|3[0-2]))$";
+
+    private static final String IP_ADDR_SHOW = "sudo ip addr show %s";
+    private static final String IP_ADDR_FLUSH = "sudo ip addr flush %s";
+    private static final String IP_ADDR_ADD = "sudo ip addr add %s dev %s";
+    private static final String IP_ADDR_DELETE = "sudo ip addr delete %s dev %s";
+    private static final String IP_LINK_SHOW = "sudo ip link show %s";
+    private static final String IP_LINK_UP = "sudo ip link set %s up";
+
+    /**
+     * Default constructor.
+     */
+    private RemoteIpCommandUtil() {
+    }
+
+    /**
+     * Adds a given IP address to a given device.
+     *
+     * @param session ssh connection
+     * @param ip ip address
+     * @param device device name to assign the ip address
+     * @return true if the command succeeds, or false
+     */
+    public static boolean addIp(Session session, IpPrefix ip, String device) {
+        if (session == null || !session.isConnected()) {
+            return false;
+        }
+
+        executeCommand(session, String.format(IP_ADDR_ADD, ip, device));
+        Set<IpPrefix> result = getCurrentIps(session, device);
+        return result.contains(ip);
+    }
+
+    /**
+     * Removes the IP address from a given device.
+     *
+     * @param session ssh connection
+     * @param ip ip address
+     * @param device device name
+     * @return true if the command succeeds, or false
+     */
+    public static boolean deleteIp(Session session, IpPrefix ip, String device) {
+        if (session == null || !session.isConnected()) {
+            return false;
+        }
+
+        executeCommand(session, String.format(IP_ADDR_DELETE, ip, device));
+        Set<IpPrefix> result = getCurrentIps(session, device);
+        return !result.contains(ip);
+    }
+
+    /**
+     * Removes all IP address on a given device.
+     *
+     * @param session ssh connection
+     * @param device device name
+     * @return true if the command succeeds, or false
+     */
+    public static boolean flushIp(Session session, String device) {
+        if (session == null || !session.isConnected()) {
+            return false;
+        }
+
+        executeCommand(session, String.format(IP_ADDR_FLUSH, device));
+        return getCurrentIps(session, device).isEmpty();
+    }
+
+    /**
+     * Returns a set of IP address that a given device has.
+     *
+     * @param session ssh connection
+     * @param device device name
+     * @return set of IP prefix or empty set
+     */
+    public static Set<IpPrefix> getCurrentIps(Session session, String device) {
+        if (session == null || !session.isConnected()) {
+            return Sets.newHashSet();
+        }
+
+        String output = executeCommand(session, String.format(IP_ADDR_SHOW, device));
+        Set<IpPrefix> result = Pattern.compile(" ")
+                .splitAsStream(output)
+                .filter(s -> s.matches(IP_PATTERN))
+                .map(IpPrefix::valueOf)
+                .collect(Collectors.toSet());
+
+        return result;
+    }
+
+    /**
+     * Sets link state up for a given device.
+     *
+     * @param session ssh connection
+     * @param device device name
+     * @return true if the command succeeds, or false
+     */
+    public static boolean setInterfaceUp(Session session, String device) {
+        if (session == null || !session.isConnected()) {
+            return false;
+        }
+
+        executeCommand(session, String.format(IP_LINK_UP, device));
+        return isInterfaceUp(session, device);
+    }
+
+    /**
+     * Checks if a given interface is up or not.
+     *
+     * @param session ssh connection
+     * @param device device name
+     * @return true if the interface is up, or false
+     */
+    public static boolean isInterfaceUp(Session session, String device) {
+        if (session == null || !session.isConnected()) {
+            return false;
+        }
+
+        String output = executeCommand(session, String.format(IP_LINK_SHOW, device));
+        return output != null && output.contains("UP");
+    }
+
+    /**
+     * Creates a new session with a given access information.
+     *
+     * @param sshInfo information to ssh to the remove server
+     * @return ssh session, or null
+     */
+    public static Session connect(SshAccessInfo sshInfo) {
+        try {
+            JSch jsch = new JSch();
+            jsch.addIdentity(sshInfo.privateKey());
+
+            Session session = jsch.getSession(sshInfo.user(),
+                                      sshInfo.remoteIp().toString(),
+                                      sshInfo.port().toInt());
+            session.setConfig(STRICT_HOST_CHECKING, DEFAULT_STRICT_HOST_CHECKING);
+            session.connect(DEFAULT_SESSION_TIMEOUT);
+
+            return session;
+        } catch (JSchException e) {
+            log.debug("Failed to connect to {} due to {}", sshInfo.toString(), e.toString());
+            return null;
+        }
+    }
+
+    /**
+     * Closes a connection.
+     *
+     * @param session session
+     */
+    public static void disconnect(Session session) {
+        if (session.isConnected()) {
+            session.disconnect();
+        }
+    }
+
+    /**
+     * Executes a given command. It opens exec channel for the command and closes
+     * the channel when it's done.
+     *
+     * @param session ssh connection to a remote server
+     * @param command command to execute
+     * @return command output string if the command succeeds, or null
+     */
+    private static String executeCommand(Session session, String command) {
+        if (session == null || !session.isConnected()) {
+            return null;
+        }
+
+        log.debug("Execute command {} to {}", command, session.getHost());
+
+        try {
+            Channel channel = session.openChannel("exec");
+            ((ChannelExec) channel).setCommand(command);
+            channel.setInputStream(null);
+            InputStream output = channel.getInputStream();
+
+            channel.connect();
+            String result = CharStreams.toString(new InputStreamReader(output));
+            channel.disconnect();
+
+            return result;
+        } catch (JSchException | IOException e) {
+            log.debug("Failed to execute command {} due to {}", command, e.toString());
+            return null;
+        }
+    }
+}

+/*
+ * Copyright 2016 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.cordvtn;
+
+import com.google.common.base.MoreObjects;
+import org.onlab.packet.Ip4Address;
+import org.onlab.packet.TpPort;
+
+import java.util.Objects;
+
+/**
+ * Representation of SSH access information.
+ */
+public final class SshAccessInfo {
+
+    private final Ip4Address remoteIp;
+    private final TpPort port;
+    private final String user;
+    private final String privateKey;
+
+    /**
+     * Creates a new SSH access information.
+     *
+     * @param remoteIp ssh remote ip address
+     * @param port ssh port number
+     * @param user user name
+     * @param privateKey path of ssh private key
+     */
+    public SshAccessInfo(Ip4Address remoteIp, TpPort port, String user, String privateKey) {
+        this.remoteIp = remoteIp;
+        this.port = port;
+        this.user = user;
+        this.privateKey = privateKey;
+    }
+
+    /**
+     * Returns the remote IP address.
+     *
+     * @return ip address
+     */
+    public Ip4Address remoteIp() {
+        return this.remoteIp;
+    }
+
+    /**
+     * Returns the port number.
+     *
+     * @return ssh port
+     */
+    public TpPort port() {
+        return this.port;
+    }
+
+    /**
+     * Returns the user name.
+     *
+     * @return user name
+     */
+    public String user() {
+        return this.user;
+    }
+
+    /**
+     * Returns the private key path.
+     *
+     * @return privateKey
+     */
+    public String privateKey() {
+        return privateKey;
+    }
+
+    @Override
+    public boolean equals(Object obj) {
+        if (this == obj) {
+            return true;
+        }
+
+        if (obj instanceof SshAccessInfo) {
+            SshAccessInfo that = (SshAccessInfo) obj;
+            if (Objects.equals(remoteIp, that.remoteIp) &&
+                    Objects.equals(port, that.port) &&
+                    Objects.equals(user, that.user) &&
+                    Objects.equals(privateKey, that.privateKey)) {
+                return true;
+            }
+        }
+        return false;
+    }
+
+    @Override
+    public int hashCode() {
+        return Objects.hash(remoteIp, port, user, privateKey);
+    }
+
+    @Override
+    public String toString() {
+        return MoreObjects.toStringHelper(getClass())
+                .add("remoteIp", remoteIp)
+                .add("port", port)
+                .add("user", user)
+                .add("privateKey", privateKey)
+                .toString();
+    }
+}