From 4f66bbcb1993ef0c681bdded41a328713ad90602 Mon Sep 17 00:00:00 2001
From: Pierantonio Merlino <pierantonio.merlino@eurotech.com>
Date: Fri, 12 May 2023 22:39:20 +0200
Subject: [PATCH] fix(net.admin): added dhclient hook files (#4645)

* Added dhclient hook scripts

Signed-off-by: pierantoniomerlino <pierantonio.merlino@eurotech.com>

* Improved dhclient hook scripts managemenet

Signed-off-by: pierantoniomerlino <pierantonio.merlino@eurotech.com>

* Updated hook script; improved installation

Signed-off-by: pierantoniomerlino <pierantonio.merlino@eurotech.com>

---------

Signed-off-by: pierantoniomerlino <pierantonio.merlino@eurotech.com>
---
 .../src/main/ant/build_equinox_distrib.xml    |   2 +
 .../resources/common/kura-dhclient-enter-hook |   3 +
 .../intel-up2-ubuntu-20/kura_install.sh       |   3 +
 .../nvidia-jetson-nano/kura_install.sh        |   3 +
 .../raspberry-pi-ubuntu-20/kura_install.sh    |   3 +
 .../resources/raspberry-pi/kura_install.sh    |   3 +
 .../META-INF/MANIFEST.MF                      |   2 +-
 .../linux/net/dhcp/DhcpClientManager.java     |  13 +-
 .../META-INF/MANIFEST.MF                      |   2 +-
 .../visitor/linux/DhcpClientConfigWriter.java | 128 ++++++++++++++++++
 .../visitor/linux/LinuxWriteVisitor.java      |   4 +-
 11 files changed, 161 insertions(+), 5 deletions(-)
 create mode 100644 kura/distrib/src/main/resources/common/kura-dhclient-enter-hook
 create mode 100644 kura/org.eclipse.kura.net.admin/src/main/java/org/eclipse/kura/net/admin/visitor/linux/DhcpClientConfigWriter.java

diff --git a/kura/distrib/src/main/ant/build_equinox_distrib.xml b/kura/distrib/src/main/ant/build_equinox_distrib.xml
index 8ee078325bd..112d728ac14 100644
--- a/kura/distrib/src/main/ant/build_equinox_distrib.xml
+++ b/kura/distrib/src/main/ant/build_equinox_distrib.xml
@@ -554,6 +554,8 @@ fi]]>
 				prefix="${build.output.name}/${install.folder}" />
 			<zipfileset file="src/main/resources/common/ifup-local.raspbian"
 				prefix="${build.output.name}/${install.folder}" />
+			<zipfileset file="src/main/resources/common/kura-dhclient-enter-hook"
+				prefix="${build.output.name}/${install.folder}" />
 
 			<zipfileset
 				file="${project.build.directory}/${build.output.name}/selinuxKura.pp"
diff --git a/kura/distrib/src/main/resources/common/kura-dhclient-enter-hook b/kura/distrib/src/main/resources/common/kura-dhclient-enter-hook
new file mode 100644
index 00000000000..3d612e8eee8
--- /dev/null
+++ b/kura/distrib/src/main/resources/common/kura-dhclient-enter-hook
@@ -0,0 +1,3 @@
+#!/bin/sh
+# Don't delete the following entry. Add custom actions after it.
+. /etc/kura-dhclient-resolv-hook
\ No newline at end of file
diff --git a/kura/distrib/src/main/resources/intel-up2-ubuntu-20/kura_install.sh b/kura/distrib/src/main/resources/intel-up2-ubuntu-20/kura_install.sh
index 7de545ba5c8..3fdf749497f 100644
--- a/kura/distrib/src/main/resources/intel-up2-ubuntu-20/kura_install.sh
+++ b/kura/distrib/src/main/resources/intel-up2-ubuntu-20/kura_install.sh
@@ -115,6 +115,9 @@ fi
 chown bind:bind /etc/bind/rndc.key
 chmod 600 /etc/bind/rndc.key
 
+#set up dhclient hooks
+cp ${INSTALL_DIR}/kura/install/kura-dhclient-enter-hook /etc/dhcp/dhclient-enter-hooks.d/zz-kura-dhclient-enter-hook
+
 #set up logrotate - no need to restart as it is a cronjob
 cp ${INSTALL_DIR}/kura/install/kura.logrotate /etc/logrotate-kura.conf
 
diff --git a/kura/distrib/src/main/resources/nvidia-jetson-nano/kura_install.sh b/kura/distrib/src/main/resources/nvidia-jetson-nano/kura_install.sh
index 75bebb7a64f..2b66c0c436b 100755
--- a/kura/distrib/src/main/resources/nvidia-jetson-nano/kura_install.sh
+++ b/kura/distrib/src/main/resources/nvidia-jetson-nano/kura_install.sh
@@ -108,6 +108,9 @@ fi
 chown bind:bind /etc/bind/rndc.key
 chmod 600 /etc/bind/rndc.key
 
+#set up dhclient hooks
+cp ${INSTALL_DIR}/kura/install/kura-dhclient-enter-hook /etc/dhcp/dhclient-enter-hooks.d/zz-kura-dhclient-enter-hook
+
 #set up logrotate - no need to restart as it is a cronjob
 cp ${INSTALL_DIR}/kura/install/kura.logrotate /etc/logrotate-kura.conf
 
diff --git a/kura/distrib/src/main/resources/raspberry-pi-ubuntu-20/kura_install.sh b/kura/distrib/src/main/resources/raspberry-pi-ubuntu-20/kura_install.sh
index d57e4fed7d5..1f4d5b631dc 100644
--- a/kura/distrib/src/main/resources/raspberry-pi-ubuntu-20/kura_install.sh
+++ b/kura/distrib/src/main/resources/raspberry-pi-ubuntu-20/kura_install.sh
@@ -110,6 +110,9 @@ fi
 chown bind:bind /etc/bind/rndc.key
 chmod 600 /etc/bind/rndc.key
 
+#set up dhclient hooks
+cp ${INSTALL_DIR}/kura/install/kura-dhclient-enter-hook /etc/dhcp/dhclient-enter-hooks.d/zz-kura-dhclient-enter-hook
+
 #set up logrotate - no need to restart as it is a cronjob
 cp ${INSTALL_DIR}/kura/install/kura.logrotate /etc/logrotate-kura.conf
 
diff --git a/kura/distrib/src/main/resources/raspberry-pi/kura_install.sh b/kura/distrib/src/main/resources/raspberry-pi/kura_install.sh
index c719c688600..6486e0fc214 100755
--- a/kura/distrib/src/main/resources/raspberry-pi/kura_install.sh
+++ b/kura/distrib/src/main/resources/raspberry-pi/kura_install.sh
@@ -105,6 +105,9 @@ fi
 chown bind:bind /etc/bind/rndc.key
 chmod 600 /etc/bind/rndc.key
 
+#set up dhclient hooks
+cp ${INSTALL_DIR}/kura/install/kura-dhclient-enter-hook /etc/dhcp/dhclient-enter-hooks.d/zz-kura-dhclient-enter-hook
+
 #set up logrotate - no need to restart as it is a cronjob
 cp ${INSTALL_DIR}/kura/install/kura.logrotate /etc/logrotate-kura.conf
 
diff --git a/kura/org.eclipse.kura.linux.net/META-INF/MANIFEST.MF b/kura/org.eclipse.kura.linux.net/META-INF/MANIFEST.MF
index a4b3dfcd053..1d728bcdc99 100644
--- a/kura/org.eclipse.kura.linux.net/META-INF/MANIFEST.MF
+++ b/kura/org.eclipse.kura.linux.net/META-INF/MANIFEST.MF
@@ -53,7 +53,7 @@ Export-Package: org.eclipse.kura.internal.board;version="1.0.0";x-internal:=true
    org.eclipse.kura.net,
    org.eclipse.kura.net.modem,
    org.eclipse.kura.usb",
- org.eclipse.kura.linux.net.dhcp;version="2.0.0";uses:="org.eclipse.kura.net.dhcp",
+ org.eclipse.kura.linux.net.dhcp;version="2.1.0";uses:="org.eclipse.kura.net.dhcp",
  org.eclipse.kura.linux.net.dns;version="1.1.0";uses:="org.eclipse.kura.net,org.eclipse.kura.net.dns",
  org.eclipse.kura.linux.net.iptables;version="1.1.0";uses:="org.eclipse.kura.net",
  org.eclipse.kura.linux.net.modem;version="1.2.0";uses:="org.osgi.service.event,org.eclipse.kura.usb",
diff --git a/kura/org.eclipse.kura.linux.net/src/main/java/org/eclipse/kura/linux/net/dhcp/DhcpClientManager.java b/kura/org.eclipse.kura.linux.net/src/main/java/org/eclipse/kura/linux/net/dhcp/DhcpClientManager.java
index d45c6b03293..c19a3205553 100644
--- a/kura/org.eclipse.kura.linux.net/src/main/java/org/eclipse/kura/linux/net/dhcp/DhcpClientManager.java
+++ b/kura/org.eclipse.kura.linux.net/src/main/java/org/eclipse/kura/linux/net/dhcp/DhcpClientManager.java
@@ -1,5 +1,5 @@
 /*******************************************************************************
- * Copyright (c) 2011, 2020 Eurotech and/or its affiliates and others
+ * Copyright (c) 2011, 2023 Eurotech and/or its affiliates and others
  * 
  * This program and the accompanying materials are made
  * available under the terms of the Eclipse Public License 2.0
@@ -30,8 +30,9 @@ public class DhcpClientManager {
 
     private static final Logger logger = LoggerFactory.getLogger(DhcpClientManager.class);
 
-    private static DhcpClientTool dhcpClientTool = DhcpClientTool.NONE;
     private static final String PID_FILE_DIR = "/var/run";
+    private static final String DHCLIENT_HOOK_SCRIPT_FILE = "/etc/kura-dhclient-resolv-hook";
+    private static DhcpClientTool dhcpClientTool = DhcpClientTool.NONE;
     private final CommandExecutorService executorService;
 
     static {
@@ -89,6 +90,14 @@ public void releaseCurrentLease(String interfaceName) throws KuraProcessExecutio
         }
     }
 
+    public static String getHookScriptFileName() {
+        if (dhcpClientTool == DhcpClientTool.DHCLIENT) {
+            return DHCLIENT_HOOK_SCRIPT_FILE;
+        } else {
+            return "";
+        }
+    }
+
     private static boolean removePidFile(String interfaceName) {
         boolean ret = true;
         File pidFile = new File(getPidFilename(interfaceName));
diff --git a/kura/org.eclipse.kura.net.admin/META-INF/MANIFEST.MF b/kura/org.eclipse.kura.net.admin/META-INF/MANIFEST.MF
index e7720143c48..72601589314 100644
--- a/kura/org.eclipse.kura.net.admin/META-INF/MANIFEST.MF
+++ b/kura/org.eclipse.kura.net.admin/META-INF/MANIFEST.MF
@@ -27,7 +27,7 @@ Import-Package: javax.microedition.io,
  org.eclipse.kura.internal.linux.net.dns;version="[1.0,2.0)",
  org.eclipse.kura.internal.linux.net.wifi;version="[1.0,2.0)",
  org.eclipse.kura.linux.net;version="[1.0,2.0)",
- org.eclipse.kura.linux.net.dhcp;version="[2.0,3.0)",
+ org.eclipse.kura.linux.net.dhcp;version="[2.1,3.0)",
  org.eclipse.kura.linux.net.dns;version="[1.0,2.0)",
  org.eclipse.kura.linux.net.iptables;version="[1.0,2.0)",
  org.eclipse.kura.linux.net.modem;version="[1.1,2.0)",
diff --git a/kura/org.eclipse.kura.net.admin/src/main/java/org/eclipse/kura/net/admin/visitor/linux/DhcpClientConfigWriter.java b/kura/org.eclipse.kura.net.admin/src/main/java/org/eclipse/kura/net/admin/visitor/linux/DhcpClientConfigWriter.java
new file mode 100644
index 00000000000..84909d55017
--- /dev/null
+++ b/kura/org.eclipse.kura.net.admin/src/main/java/org/eclipse/kura/net/admin/visitor/linux/DhcpClientConfigWriter.java
@@ -0,0 +1,128 @@
+/*******************************************************************************
+ * Copyright (c) 2023 Eurotech and/or its affiliates and others
+ * 
+ * This program and the accompanying materials are made
+ * available under the terms of the Eclipse Public License 2.0
+ * which is available at https://www.eclipse.org/legal/epl-2.0/
+ * 
+ * SPDX-License-Identifier: EPL-2.0
+ * 
+ * Contributors:
+ *  Eurotech
+ *******************************************************************************/
+package org.eclipse.kura.net.admin.visitor.linux;
+
+import java.io.IOException;
+import java.nio.charset.StandardCharsets;
+import java.nio.file.Files;
+import java.nio.file.Path;
+import java.nio.file.Paths;
+import java.util.ArrayList;
+import java.util.List;
+import java.util.stream.Collectors;
+
+import org.eclipse.kura.KuraException;
+import org.eclipse.kura.KuraIOException;
+import org.eclipse.kura.core.net.AbstractNetInterface;
+import org.eclipse.kura.core.net.NetworkConfiguration;
+import org.eclipse.kura.core.net.NetworkConfigurationVisitor;
+import org.eclipse.kura.executor.CommandExecutorService;
+import org.eclipse.kura.linux.net.dhcp.DhcpClientManager;
+import org.eclipse.kura.linux.net.dhcp.DhcpClientTool;
+import org.eclipse.kura.net.NetInterfaceAddressConfig;
+import org.eclipse.kura.net.NetInterfaceConfig;
+import org.eclipse.kura.net.NetInterfaceStatus;
+import org.eclipse.kura.net.NetInterfaceType;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+public class DhcpClientConfigWriter implements NetworkConfigurationVisitor {
+
+    private static final Logger logger = LoggerFactory.getLogger(DhcpClientConfigWriter.class);
+    private static final String DEFAULT_HOOK_SCRIPT = "#!/bin/sh\n"
+            + "\n"
+            + "interfaces=\"\"\n"
+            + "\n"
+            + "for item in $interfaces; do \n"
+            + "    if [ \"$item\" = \"$interface\" ]; then\n"
+            + "        make_resolv_conf(){\n"
+            + "            logger \"Don't set DNS address for $interface\"\n"
+            + "            :\n"
+            + "        }\n"
+            + "    fi\n"
+            + "done";
+
+    public DhcpClientConfigWriter() {
+        // Do nothing...
+    }
+
+    @Override
+    public void setExecutorService(CommandExecutorService executorService) {
+        // Not needed
+    }
+
+    @Override
+    public void visit(NetworkConfiguration config) throws KuraException {
+        if (DhcpClientManager.getTool() != DhcpClientTool.DHCLIENT) {
+            logger.debug("Hook scripts are supported only by dhclient. Do nothing.");
+            return;
+        }
+
+        List<String> lanInterfaceNames = new ArrayList<>();
+        List<NetInterfaceConfig<? extends NetInterfaceAddressConfig>> netInterfaceConfigs = config
+                .getModifiedNetInterfaceConfigs();
+        for (NetInterfaceConfig<? extends NetInterfaceAddressConfig> netInterfaceConfig : netInterfaceConfigs) {
+            boolean isLan = ((AbstractNetInterface<?>) netInterfaceConfig)
+                    .getInterfaceStatus() == NetInterfaceStatus.netIPv4StatusEnabledLAN;
+            if (isLan && (netInterfaceConfig.getType() == NetInterfaceType.ETHERNET
+                    || netInterfaceConfig.getType() == NetInterfaceType.WIFI)) {
+                lanInterfaceNames.add(netInterfaceConfig.getName());
+            }
+        }
+
+        lanInterfaceNames.sort(null);
+        writeDhcpClientConfig(lanInterfaceNames);
+    }
+
+    private void writeDhcpClientConfig(List<String> interfaceNames) {
+        String hookScriptFileName = DhcpClientManager.getHookScriptFileName();
+        if (hookScriptFileName == null || hookScriptFileName.isEmpty()) {
+            logger.debug("Hook script file name not defined. Do nothing.");
+            return;
+        }
+
+        try {
+            writeDhclientHookScript(interfaceNames, hookScriptFileName);
+        } catch (KuraIOException e) {
+            logger.error("Failed to write dhclient hook script", e);
+        }
+    }
+
+    private void writeDhclientHookScript(List<String> interfaceNames, String hookScriptFileName)
+            throws KuraIOException {
+        StringBuilder interfacesLine = new StringBuilder("interfaces=\"");
+        interfacesLine.append(interfaceNames.stream().collect(Collectors.joining(" ")));
+        interfacesLine.append("\"\n");
+        String hookScriptContent = DEFAULT_HOOK_SCRIPT.replace("interfaces=\"\"\n", interfacesLine);
+
+        Path hookScriptFilePath = Paths.get(hookScriptFileName);
+        try {
+            if (Files.exists(hookScriptFilePath) && Files.isReadable(hookScriptFilePath)) {
+                String currentHookScriptContent = new String(Files.readAllBytes(hookScriptFilePath),
+                        StandardCharsets.UTF_8);
+                if (!hookScriptContent.equals(currentHookScriptContent)) {
+                    writeFile(hookScriptFilePath, hookScriptContent);
+                }
+            } else {
+                writeFile(hookScriptFilePath, hookScriptContent);
+            }
+        } catch (IOException e) {
+            throw new KuraIOException(e, "Failed to update dhclient hook script");
+        }
+    }
+
+    private void writeFile(Path path, String content) throws IOException {
+        Files.write(path, content.getBytes(StandardCharsets.UTF_8));
+    }
+
+}
diff --git a/kura/org.eclipse.kura.net.admin/src/main/java/org/eclipse/kura/net/admin/visitor/linux/LinuxWriteVisitor.java b/kura/org.eclipse.kura.net.admin/src/main/java/org/eclipse/kura/net/admin/visitor/linux/LinuxWriteVisitor.java
index 19d0e3da645..2c982aae50b 100644
--- a/kura/org.eclipse.kura.net.admin/src/main/java/org/eclipse/kura/net/admin/visitor/linux/LinuxWriteVisitor.java
+++ b/kura/org.eclipse.kura.net.admin/src/main/java/org/eclipse/kura/net/admin/visitor/linux/LinuxWriteVisitor.java
@@ -33,6 +33,7 @@ private LinuxWriteVisitor() {
         this.visitors.add(new WifiConfigWriter());
         this.visitors.add(new PppConfigWriter());
         this.visitors.add(new DhcpConfigWriter());
+        this.visitors.add(new DhcpClientConfigWriter());
         this.visitors.add(new FirewallAutoNatConfigWriter());
     }
 
@@ -51,7 +52,8 @@ public void visit(NetworkConfiguration config) throws KuraException {
             visitor.visit(config);
         }
 
-        // After every visit, unset the executorService. This must be set before every call.
+        // After every visit, unset the executorService. This must be set before every
+        // call.
         this.executorService = null;
     }