远程命令支持

src/main/java/com/virjar/echo/nat/client/EchoClient.java

 package com.virjar.echo.nat.client;
 
+import com.virjar.echo.nat.cmd.CmdHandler;
 import com.virjar.echo.nat.log.EchoLogger;
 import com.virjar.echo.nat.protocol.EchoPacket;
 import com.virjar.echo.nat.protocol.EchoPacketDecoder;
@@ -7,6 +8,7 @@ import com.virjar.echo.nat.protocol.EchoPacketEncoder;
 import com.virjar.echo.nat.protocol.PacketCommon;
 
 import java.nio.charset.StandardCharsets;
+import java.util.HashMap;
 import java.util.Map;
 import java.util.concurrent.ConcurrentHashMap;
 import java.util.concurrent.TimeUnit;
@@ -33,14 +35,26 @@ public class EchoClient {
     private String clientId;
     private String adminAccount;
 
+    private Map<String, CmdHandler> cmdHandlerMap = new HashMap<>();
+
     public EchoClient(String natServerHost, int natServerPort, String clientId) {
         this.natServerHost = natServerHost;
         this.natServerPort = natServerPort;
         this.clientId = clientId;
     }
 
-    public void setAdminAccount(String adminAccount) {
+    public EchoClient setAdminAccount(String adminAccount) {
         this.adminAccount = adminAccount;
+        return this;
+    }
+
+    public EchoClient registerCmdHandler(CmdHandler cmdHandler) {
+        cmdHandlerMap.put(cmdHandler.action().toUpperCase(), cmdHandler);
+        return this;
+    }
+
+    public CmdHandler queryCmdHandler(String action) {
+        return cmdHandlerMap.get(action.toUpperCase());
     }
 
     private Bootstrap echoClientBootstrap;

src/main/java/com/virjar/echo/nat/client/EchoClientChannelHandler.java

 package com.virjar.echo.nat.client;
 
+import com.virjar.echo.nat.cmd.CmdHandler;
+import com.virjar.echo.nat.cmd.CmdResponse;
 import com.virjar.echo.nat.log.EchoLogger;
 import com.virjar.echo.nat.protocol.EchoPacket;
 import com.virjar.echo.nat.protocol.PacketCommon;
-import io.netty.channel.*;
 
 import java.util.concurrent.TimeUnit;
 
+import io.netty.channel.ChannelFuture;
+import io.netty.channel.ChannelFutureListener;
+import io.netty.channel.ChannelHandlerContext;
+import io.netty.channel.SimpleChannelInboundHandler;
+
 public class EchoClientChannelHandler extends SimpleChannelInboundHandler<EchoPacket> {
 
     private EchoClient echoClient;
@@ -32,7 +38,9 @@ public class EchoClientChannelHandler extends SimpleChannelInboundHandler<EchoPa
             case PacketCommon.TYPE_DISCONNECT:
                 handleDisconnectMessage(msg);
                 break;
-
+            case PacketCommon.C_TYPE_CONTROL:
+                handleControlMessage(ctx, msg);
+                break;
             default:
                 EchoLogger.getLogger().warn("Unknown message type:" + msg.getType());
                 break;
@@ -40,6 +48,29 @@ public class EchoClientChannelHandler extends SimpleChannelInboundHandler<EchoPa
 
     }
 
+    private void handleControlMessage(ChannelHandlerContext ctx, EchoPacket msg) {
+        long seq = msg.getSerialNumber();
+        String action = msg.getExtra();
+        String cmdParam = "";
+        byte[] data = msg.getData();
+        if (data != null) {
+            cmdParam = new String(data);
+        }
+        CmdResponse cmdResponse = new CmdResponse(seq, ctx.channel());
+        CmdHandler cmdHandler = echoClient.queryCmdHandler(action);
+        if (cmdHandler == null) {
+            cmdResponse.failed("NO_ACTION_" + action);
+            return;
+        }
+        try {
+            cmdHandler.handle(cmdParam, cmdResponse);
+        } catch (Exception e) {
+            EchoLogger.getLogger().error("failed to call cmdHandler: " + action
+                    + " param->" + cmdParam, e);
+            cmdResponse.failed("error action:" + action + " param:" + cmdParam + " e:" + e.getMessage());
+        }
+    }
+
     private void handleDisconnectMessage(EchoPacket msg) {
         // 关闭真实服务器的链接，比如baidu.com:443
         echoClient.closeRealServerConnection(msg.getSerialNumber());

src/main/java/com/virjar/echo/nat/cmd/CmdHandler.java

+package com.virjar.echo.nat.cmd;
+
+public interface CmdHandler {
+    String action();
+
+    void handle(String param, CmdResponse cmdResponse);
+}

src/main/java/com/virjar/echo/nat/cmd/CmdResponse.java

+package com.virjar.echo.nat.cmd;
+
+
+import com.virjar.echo.nat.protocol.EchoPacket;
+import com.virjar.echo.nat.protocol.PacketCommon;
+
+import java.nio.charset.StandardCharsets;
+
+import io.netty.channel.Channel;
+
+public class CmdResponse {
+    private long req;
+    private Channel natChannel;
+    private boolean respond = false;
+
+    public CmdResponse(long req, Channel natChannel) {
+        this.req = req;
+        this.natChannel = natChannel;
+    }
+
+    public static final String STATUS_OK = "OK";
+    public static final String STATUS_FAILED = "FAILED";
+
+    public void success(String response) {
+        ack(STATUS_OK, response);
+    }
+
+    public void failed(String errorMessage) {
+        ack(STATUS_FAILED, errorMessage);
+    }
+
+    public synchronized void ack(String status, String response) {
+        if (respond) {
+            return;
+        }
+        respond = true;
+        EchoPacket ackMessage = new EchoPacket();
+        ackMessage.setSerialNumber(req);
+        ackMessage.setType(PacketCommon.C_TYPE_CONTROL);
+        String totalResponse = status;
+        if (response != null) {
+            totalResponse = totalResponse + ":" + response;
+        }
+        ackMessage.setData(totalResponse.getBytes(StandardCharsets.UTF_8));
+        natChannel.writeAndFlush(ackMessage);
+    }
+}

src/main/java/com/virjar/echo/nat/cmd/ShellCmdHandler.java

+package com.virjar.echo.nat.cmd;
+
+import com.virjar.echo.nat.log.EchoLogger;
+
+import java.io.BufferedReader;
+import java.io.IOException;
+import java.io.InputStream;
+import java.io.InputStreamReader;
+
+public class ShellCmdHandler implements CmdHandler {
+    @Override
+    public String action() {
+        return "shell";
+    }
+
+    @Override
+    public void handle(String param, CmdResponse cmdResponse) {
+        new Thread("") {
+            @Override
+            public void run() {
+                try {
+                    EchoLogger.getLogger().info("execute shell:" + param);
+                    Process process = Runtime.getRuntime().exec(param);
+
+                    StringBuffer out = new StringBuffer();
+                    StringBuffer error = new StringBuffer();
+
+                    autoFillOutput(process.getInputStream(), out);
+                    autoFillOutput(process.getErrorStream(), error);
+                    process.waitFor();
+
+                    cmdResponse.success(out + "\n\n" + error);
+                } catch (Exception e) {
+                    e.printStackTrace();
+                    EchoLogger.getLogger().error("error when execute cmd", e);
+                }
+            }
+        }.start();
+
+    }
+
+    private static void autoFillOutput(InputStream inputStream, StringBuffer stringBuffer) {
+        new Thread() {
+            @Override
+            public void run() {
+                try {
+                    BufferedReader bufferedReader = new BufferedReader(new InputStreamReader(inputStream));
+                    String line;
+                    while ((line = bufferedReader.readLine()) != null) {
+                        stringBuffer.append(line).append("\n");
+                    }
+                    bufferedReader.close();
+                } catch (IOException e) {
+                    e.printStackTrace();
+                } finally {
+                    try {
+                        inputStream.close();
+                    } catch (IOException e) {
+                        e.printStackTrace();
+                    }
+                }
+            }
+        }.start();
+    }
+}