From c6c44769e246d4d73f5beffe5b40f8097461b746 Mon Sep 17 00:00:00 2001
From: Simon Rettberg
Date: Fri, 10 Jan 2020 10:38:33 +0100
Subject: [WakeOnLan] Native Java implementation

Gets rid of any dependency on installed tools.
---
 .../org/openslx/taskmanager/tasks/WakeOnLan.java   | 140 +++++++++++++++------
 1 file changed, 102 insertions(+), 38 deletions(-)

diff --git a/src/main/java/org/openslx/taskmanager/tasks/WakeOnLan.java b/src/main/java/org/openslx/taskmanager/tasks/WakeOnLan.java
index 36ec7d6..74b776d 100644
--- a/src/main/java/org/openslx/taskmanager/tasks/WakeOnLan.java
+++ b/src/main/java/org/openslx/taskmanager/tasks/WakeOnLan.java
@@ -1,30 +1,41 @@
 package org.openslx.taskmanager.tasks;
 
-import java.util.Arrays;
+import java.io.IOException;
+import java.net.DatagramPacket;
+import java.net.DatagramSocket;
+import java.net.InetAddress;
+import java.net.SocketException;
+import java.net.UnknownHostException;
+import java.util.regex.Matcher;
+import java.util.regex.Pattern;
 
-import org.openslx.satserver.util.Exec;
-import org.openslx.satserver.util.Exec.ExecCallback;
 import org.openslx.satserver.util.Util;
 import org.openslx.taskmanager.api.AbstractTask;
 
 import com.google.gson.annotations.Expose;
 
-public class WakeOnLan extends AbstractTask implements ExecCallback
+public class WakeOnLan extends AbstractTask
 {
-	
+
+	private static final Pattern RE_IPv4 =
+			Pattern.compile( "^(\\d+)\\.(\\d+)\\.(\\d+)\\.(\\d+)$" );
+	private static final Pattern RE_MAC =
+			Pattern.compile( "^([0-9a-f]{2})[:-]([0-9a-f]{2}+)[:-]([0-9a-f]{2}+)[:-]([0-9a-f]{2}+)[:-]([0-9a-f]{2}+)[:-]([0-9a-f]{2}+)$",
+					Pattern.CASE_INSENSITIVE );
+
 	@Expose
 	private String[] macs;
-	
+
 	@Expose
 	private String ip;
-	
+
 	@Expose
 	private String password;
-	
-	private String[] cmdline;
 
 	private StatusObject status;
 
+	private byte[] buffer;
+
 	@Override
 	protected boolean initTask()
 	{
@@ -36,48 +47,101 @@ public class WakeOnLan extends AbstractTask implements ExecCallback
 		if ( Util.isEmpty( ip ) ) {
 			status.addMsg( "IP empty" );
 		}
+		int pwlen = 0;
+		Matcher m = null;
+		if ( !Util.isEmpty( password ) ) {
+			m = RE_IPv4.matcher( password );
+			if ( m.matches() ) {
+				pwlen = 4;
+			} else {
+				m = RE_MAC.matcher( password );
+				if ( m.matches() ) {
+					pwlen = 6;
+				}
+			}
+			if ( pwlen == 0 ) {
+				status.addMsg( "Invalid password format: " + password );
+			}
+		}
 		if ( !Util.isEmpty( status.messages ) )
 			return false;
-		int xlen = Util.isEmpty( password ) ? 0 : 2; 
-		cmdline = new String[macs.length + 3 + xlen];
-		cmdline[0] = "jawol";
-		cmdline[1] = "-d";
-		cmdline[2] = ip;
-		if ( xlen != 0 ) {
-			cmdline[3] = "-p";
-			cmdline[4] = password;
+		buffer = new byte[ 17 * 6 + pwlen ];
+		if ( pwlen != 0 ) {
+			try {
+				for ( int i = 0; i < pwlen; ++i ) {
+					int x = Integer.parseInt( m.group( i + 1 ), pwlen == 4 ? 10 : 16 );
+					buffer[17 * 6 + i] = (byte)x;
+				}
+			} catch ( Throwable t ) {
+				status.addMsg( "Invalid octet in password" );
+				return false;
+			}
 		}
-		System.arraycopy( macs, 0, cmdline, 3 + xlen, macs.length );
-		status.addMsg( "Command line: " + Arrays.toString( cmdline ) );
 		return true;
 	}
 
 	@Override
 	protected boolean execute()
 	{
-		int ret;
-		for ( int i = 0; i < 2; ++i ) {
-			ret = Exec.sync( 1, this, cmdline );
-			if ( ret != 0 )
-				return false;
+		DatagramSocket sock = null;
+		try {
 			try {
-				Thread.sleep( 800 );
-			} catch ( InterruptedException e ) {
+				sock = new DatagramSocket();
+				sock.setBroadcast( true );
+			} catch ( SocketException e ) {
+				status.addMsg( "Cannot create UDP socket" );
+				return false;
 			}
-		}
-		return Exec.sync( 1, cmdline ) == 0;
-	}
 
-	@Override
-	public void processStdOut( String line )
-	{
-		status.addMsg( line );
-	}
+			// Sync bytes
+			for ( int i = 0; i < 6; ++i ) {
+				buffer[i] = -1;
+			}
 
-	@Override
-	public void processStdErr( String line )
-	{
-		status.addMsg( line );
+			// Repeat three times
+			for ( int reps = 0; reps < 3; ++reps ) {
+				if ( reps != 0 ) {
+					try {
+						Thread.sleep( 600 );
+					} catch ( InterruptedException t ) {
+						Thread.currentThread().interrupt();
+						break;
+					}
+				}
+				// For each MAC
+				for ( int mi = 0; mi < macs.length; ++mi ) {
+					Matcher m = RE_MAC.matcher( macs[mi] );
+					if ( !m.matches() ) {
+						status.addMsg( "Cannot parse MAC address " + macs[mi] );
+						continue;
+					}
+					try {
+						for ( int i = 0; i < 6; ++i ) {
+							byte x = (byte)Integer.parseInt( m.group( i + 1 ), 16 );
+							for ( int offset = 0; offset < 16; ++offset ) {
+								buffer[6 + offset * 6 + i] = x;
+							}
+						}
+					} catch ( NumberFormatException e ) {
+						status.addMsg( "Invalid octet in MAC address: " + macs[mi] );
+						continue;
+					}
+					DatagramPacket dp = new DatagramPacket( buffer, buffer.length, InetAddress.getByName( ip ), 9 );
+					try {
+						sock.send( dp );
+						status.addMsg( "Sent packet to " + macs[mi] );
+					} catch ( IOException e ) {
+						status.addMsg( "Error sending UDP packet to " + ip + "/" + macs[mi] + ": " + e.toString() );
+					}
+				}
+			}
+		} catch ( UnknownHostException e ) {
+			status.addMsg( "Cannot resolve " + ip );
+			return false;
+		} finally {
+			Util.multiClose( sock );
+		}
+		return true;
 	}
 
 	class StatusObject
-- 
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