Add SIGHUP handling to reload ssl certificates. Close #134

build.gradle

@@ -54,7 +54,7 @@ dependencies {
     if (file('modules/sockets/build.gradle').exists()) {
         bundle project(":sockets")
     } else {
-        bundle group: 'com.dfbnc', name: 'sockets', version: '0.3'
+        bundle group: 'com.dfbnc', name: 'sockets', version: '0.3.1'
     }
 
     if (file('modules/parser/build.gradle').exists()) {

src/com/dfbnc/DFBnc.java

@@ -108,6 +108,9 @@ public class DFBnc implements NewSocketReadyHandler {
     /** Shutdown hook. */
     private ShutdownHook shutdownHook;
 
+    /** Signal Handler. */
+    private SignalHandler signalHandler;
+
     /** Daemon. */
     public final static DFBncDaemon daemon = new DFBncDaemon();
 
@@ -170,6 +173,8 @@ private void init(final String[] args) {
         shutdownHook = new ShutdownHook(this);
         Runtime.getRuntime().addShutdownHook(shutdownHook);
 
+        signalHandler = new SignalHandler(this);
+
         setupLogging();
 
         if (DFBncDaemon.canFork() && daemon.isDaemonized()) {
@@ -194,6 +199,7 @@ private void init(final String[] args) {
                 // Before forking, close any sockets and files.
                 Logger.setLevel(LogLevel.SILENT);
                 shutdownHook.inactivate();
+                signalHandler.inactivate();
                 this.shutdown(true);
 
                 // Daemonise.
@@ -377,6 +383,19 @@ public void setupLogging() {
         }
     }
 
+    public void createSSLContextManager() {
+        if ("pem".equalsIgnoreCase(getConfig().getOption("ssl", "source"))) {
+            sslContextManager = new SSLContextManager(
+                    getConfig().getOption("ssl", "certificatefile"),
+                    getConfig().getOption("ssl", "privatekeyfile"));
+        } else {
+            sslContextManager = new SSLContextManager(
+                    getConfig().getOption("ssl", "keystore"),
+                    getConfig().getOption("ssl", "storepass"),
+                    getConfig().getOption("ssl", "keypass"));
+        }
+    }
+
     /**
      * Open the listen sockets.
      */
@@ -386,16 +405,7 @@ public void openListenSockets() {
         final List<String> listenhosts = config.getOptionList("general", "listenhost");
 
         if (sslContextManager == null) {
-            if ("pem".equalsIgnoreCase(getConfig().getOption("ssl", "source"))) {
-                sslContextManager = new SSLContextManager(
-                        getConfig().getOption("ssl", "certificatefile"),
-                        getConfig().getOption("ssl", "privatekeyfile"));
-            } else {
-                sslContextManager = new SSLContextManager(
-                        getConfig().getOption("ssl", "keystore"),
-                        getConfig().getOption("ssl", "storepass"),
-                        getConfig().getOption("ssl", "keypass"));
-            }
+            createSSLContextManager();
         }
 
         for (String listenhost : listenhosts) {
@@ -493,6 +503,20 @@ public MultiWriter getMultiWriter() {
         return multiWriter;
     }
 
+    /**
+     * Handle signal
+     *
+     * @param signal Signal name to handle.
+     */
+    public void signal(final String signal) {
+        if (signal.equalsIgnoreCase("HUP")) {
+            Logger.info("Got sighup.");
+
+            Logger.info("Resetting SSL Context.");
+            sslContextManager.setSSLContext(null);
+        }
+    }
+
     /**
      * Handle shutdown
      */
@@ -555,6 +579,10 @@ public void shutdown(final boolean shuttingDown) {
 
         Logger.info("Deactivating shutdown hook.");
         if (shutdownHook != null) { shutdownHook.inactivate(); }
+
+        Logger.info("Deactivating signal handler.");
+        if (signalHandler != null) { signalHandler.inactivate(); }
+
         if (!shuttingDown) {
             Logger.info("Exiting.");
             System.exit(0);

src/com/dfbnc/SignalHandler.java

@@ -0,0 +1,89 @@
+/*
+ *  Copyright 2017 Shane Mc Cormack <shanemcc@gmail.com>.
+ *  See LICENSE.txt for licensing details.
+ */
+package com.dfbnc;
+
+import java.lang.reflect.Constructor;
+import java.lang.reflect.InvocationHandler;
+import java.lang.reflect.InvocationTargetException;
+import java.lang.reflect.Method;
+import java.lang.reflect.Proxy;
+import uk.org.dataforce.libs.logger.Logger;
+
+/**
+ * Handle signals sent to BNC where possible.
+ * This relies on sun.misc.Signal and sun.misc.SignalHandler which may not be
+ * in every JVM, so we use reflection to use them where possible.
+ *
+ * @author Shane Mc Cormack <shanemcc@gmail.com>
+ */
+public class SignalHandler {
+    /** The DFBnc instance that this SignalHandler is for. */
+    private final DFBnc myBnc;
+
+    /** Ignore signals if we are deactivated. */
+    private boolean inactive;
+
+    /**
+     * Create the SignalHandler
+     *
+     * @param bnc DFBnc instance
+     */
+    public SignalHandler(final DFBnc bnc) {
+        myBnc = bnc;
+        inactive = false;
+
+        try {
+            activate();
+        } catch (final Exception ex) {
+            Logger.error("Unable to listen for signals: " + ex.getMessage());
+        }
+    }
+
+    public void activate() throws ClassNotFoundException, NoSuchMethodException, InstantiationException, IllegalAccessException, IllegalArgumentException, InvocationTargetException {
+        final Class<?> handlerCl = Class.forName("sun.misc.SignalHandler");
+        final Class<?> signalCl = Class.forName("sun.misc.Signal");
+
+        final Constructor signalCtor = signalCl.getConstructor(String.class);
+        final Method signalHandle = signalCl.getMethod("handle", signalCl, handlerCl);
+
+        // Create a proxy class that implements SignalHandler
+        final Class<?> proxyClass = Proxy.getProxyClass(signalCl.getClassLoader(), handlerCl);
+
+        // This is used by the instance of proxyClass to dispatch method calls
+        final InvocationHandler invHandler = (final Object proxy, final Method method, final Object[] args) -> {
+            // proxy is the SignalHandler's "this" rederence
+            // method will be the handle(Signal) method
+            // args[0] will be an instance of Signal
+            // If you're using this object for multiple signals, you'll
+            // you'll need to use the "getName" method to determine which
+            // signal you have caught.
+
+            try {
+                final Method signalGetName = signalCl.getMethod("getName");
+                final String name = (String)signalGetName.invoke(args[0]);
+
+                myBnc.signal(name);
+            } catch (final Throwable t) {
+                /** Do nothing. */
+            }
+
+            return null;
+        };
+
+        // Get the constructor and create an instance of proxyClass
+        final Constructor<?> proxyCtor = proxyClass.getConstructor(InvocationHandler.class);
+        final Object handler = proxyCtor.newInstance(invHandler);
+
+        // Create the signal and call Signal.handle to bind handler to signal
+        signalHandle.invoke(null, signalCtor.newInstance("HUP"), handler);
+    }
+
+    /**
+     * Inactivates this handler.
+     */
+    public void inactivate() {
+        inactive = true;
+    }
+}