Pipe: Refactor AirGap receiver with configurable payload size control (#17443)

* Pipe: add hot-reloadable AirGap payload size guard to mitigate DoS risk.

Introduce a dedicated AirGap receiver payload limit in the pipe config and enforce it before request buffer allocation, so oversized payloads are rejected early and memory pressure is bounded under malicious or malformed inputs.

Made-with: Cursor

* update

* update

* update

* update

* update

* spotless

Author: luoluoyuyu

iotdb-core/datanode/src/main/java/org/apache/iotdb/db/pipe/receiver/protocol/airgap/IoTDBAirGapReceiver.java

@@ -222,14 +222,22 @@ private boolean checkSum(byte[] bytes) {
     }
   }
 
-  private byte[] readData(final InputStream inputStream) throws IOException {
+  byte[] readData(final InputStream inputStream) throws IOException {
     final int length = readLength(inputStream);
 
     if (length <= 0) {
       // Will fail() after checkSum()
       return new byte[0];
     }
 
+    final int maxLength = PipeConfig.getInstance().getPipeAirGapReceiverMaxPayloadSizeInBytes();
+    if (length > maxLength) {
+      throw new IOException(
+          String.format(
+              "AirGap payload length (%d) exceeds maximum allowed (%d). Closing connection from %s",
+              length, maxLength, socket.getRemoteSocketAddress()));
+    }
+
     final byte[] resultBuffer = new byte[length];
     readTillFull(inputStream, resultBuffer);
     if (isELanguagePayload) {
@@ -238,11 +246,16 @@ private byte[] readData(final InputStream inputStream) throws IOException {
     return resultBuffer;
   }
 
+  private int readLength(final InputStream inputStream) throws IOException {
+    return readLength(inputStream, false);
+  }
+
   /**
    * Read the length of the following data. The thread may typically block here when there is no
    * data to read.
    */
-  private int readLength(final InputStream inputStream) throws IOException {
+  private int readLength(final InputStream inputStream, final boolean isELanguage)
+      throws IOException {
     final byte[] doubleIntLengthBytes = new byte[2 * INT_LEN];
     readTillFull(inputStream, doubleIntLengthBytes);
 
@@ -251,10 +264,16 @@ private int readLength(final InputStream inputStream) throws IOException {
     if (Arrays.equals(
         doubleIntLengthBytes,
         BytesUtils.subBytes(AirGapELanguageConstant.E_LANGUAGE_PREFIX, 0, 2 * INT_LEN))) {
+      if (isELanguage) {
+        throw new IOException(
+            String.format(
+                "Detected suspicious nested E-Language prefix. Closing connection from %s",
+                socket.getRemoteSocketAddress()));
+      }
       isELanguagePayload = true;
       skipTillEnough(
           inputStream, (long) AirGapELanguageConstant.E_LANGUAGE_PREFIX.length - 2 * INT_LEN);
-      return readLength(inputStream);
+      return readLength(inputStream, true);
     }
 
     final byte[] dataLengthBytes = BytesUtils.subBytes(doubleIntLengthBytes, 0, INT_LEN);

iotdb-core/datanode/src/test/java/org/apache/iotdb/db/pipe/receiver/protocol/airgap/IoTDBAirGapReceiverTest.java

@@ -0,0 +1,72 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you 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.apache.iotdb.db.pipe.receiver.protocol.airgap;
+
+import org.apache.iotdb.commons.conf.CommonConfig;
+import org.apache.iotdb.commons.conf.CommonDescriptor;
+import org.apache.iotdb.commons.pipe.sink.payload.airgap.AirGapELanguageConstant;
+
+import org.apache.tsfile.utils.BytesUtils;
+import org.junit.Assert;
+import org.junit.Test;
+
+import java.io.ByteArrayInputStream;
+import java.io.IOException;
+import java.io.InputStream;
+import java.net.Socket;
+
+public class IoTDBAirGapReceiverTest {
+
+  @Test
+  public void testRejectOversizedAirGapPayload() throws Exception {
+    final CommonConfig commonConfig = CommonDescriptor.getInstance().getConfig();
+    final int originalMaxPayload = commonConfig.getPipeAirGapReceiverMaxPayloadSizeInBytes();
+
+    try {
+      commonConfig.setPipeAirGapReceiverMaxPayloadSizeInBytes(16);
+      final IoTDBAirGapReceiver receiver = new IoTDBAirGapReceiver(new Socket(), 1L);
+
+      final byte[] oversizedLength = BytesUtils.intToBytes(32);
+      final InputStream inputStream =
+          new ByteArrayInputStream(BytesUtils.concatByteArray(oversizedLength, oversizedLength));
+
+      final IOException exception =
+          Assert.assertThrows(IOException.class, () -> receiver.readData(inputStream));
+      Assert.assertTrue(exception.getMessage().contains("payload length"));
+    } finally {
+      commonConfig.setPipeAirGapReceiverMaxPayloadSizeInBytes(originalMaxPayload);
+    }
+  }
+
+  @Test
+  public void testRejectNestedELanguagePrefix() throws Exception {
+    final IoTDBAirGapReceiver receiver = new IoTDBAirGapReceiver(new Socket(), 2L);
+
+    final InputStream inputStream =
+        new ByteArrayInputStream(
+            BytesUtils.concatByteArray(
+                AirGapELanguageConstant.E_LANGUAGE_PREFIX,
+                AirGapELanguageConstant.E_LANGUAGE_PREFIX));
+
+    final IOException exception =
+        Assert.assertThrows(IOException.class, () -> receiver.readData(inputStream));
+    Assert.assertTrue(exception.getMessage().contains("nested E-Language prefix"));
+  }
+}

iotdb-core/node-commons/src/main/java/org/apache/iotdb/commons/conf/CommonConfig.java

@@ -311,6 +311,11 @@ public class CommonConfig {
   private double pipeReceiverActualToEstimatedMemoryRatio = 3;
 
   private int pipeReceiverReqDecompressedMaxLengthInBytes = 1073741824; // 1GB
+  // Align with default thrift frame size calculation.
+  private int pipeAirGapReceiverMaxPayloadSizeInBytes =
+      Math.min(
+          64 * 1024 * 1024,
+          (int) Math.min(Runtime.getRuntime().maxMemory() / 64, Integer.MAX_VALUE));
   private boolean pipeReceiverLoadConversionEnabled = false;
   private volatile long pipePeriodicalLogMinIntervalSeconds = 60;
   private volatile long pipeLoggerCacheMaxSizeInBytes = 16 * MB;
@@ -1702,6 +1707,23 @@ public void setPipeReceiverReqDecompressedMaxLengthInBytes(
         pipeReceiverReqDecompressedMaxLengthInBytes);
   }
 
+  public void setPipeAirGapReceiverMaxPayloadSizeInBytes(
+      int pipeAirGapReceiverMaxPayloadSizeInBytes) {
+    if (pipeAirGapReceiverMaxPayloadSizeInBytes <= 0) {
+      logger.info(
+          "Ignore invalid pipeAirGapReceiverMaxPayloadSizeInBytes {}, because it must be greater than 0.",
+          pipeAirGapReceiverMaxPayloadSizeInBytes);
+      return;
+    }
+    if (this.pipeAirGapReceiverMaxPayloadSizeInBytes == pipeAirGapReceiverMaxPayloadSizeInBytes) {
+      return;
+    }
+    this.pipeAirGapReceiverMaxPayloadSizeInBytes = pipeAirGapReceiverMaxPayloadSizeInBytes;
+    logger.info(
+        "pipeAirGapReceiverMaxPayloadSizeInBytes is set to {}.",
+        pipeAirGapReceiverMaxPayloadSizeInBytes);
+  }
+
   public boolean isPipeReceiverLoadConversionEnabled() {
     return pipeReceiverLoadConversionEnabled;
   }
@@ -1743,6 +1765,10 @@ public int getPipeReceiverReqDecompressedMaxLengthInBytes() {
     return pipeReceiverReqDecompressedMaxLengthInBytes;
   }
 
+  public int getPipeAirGapReceiverMaxPayloadSizeInBytes() {
+    return pipeAirGapReceiverMaxPayloadSizeInBytes;
+  }
+
   public double getPipeMetaReportMaxLogNumPerRound() {
     return pipeMetaReportMaxLogNumPerRound;
   }

iotdb-core/node-commons/src/main/java/org/apache/iotdb/commons/pipe/config/PipeConfig.java

@@ -361,6 +361,10 @@ public int getPipeReceiverReqDecompressedMaxLengthInBytes() {
     return COMMON_CONFIG.getPipeReceiverReqDecompressedMaxLengthInBytes();
   }
 
+  public int getPipeAirGapReceiverMaxPayloadSizeInBytes() {
+    return COMMON_CONFIG.getPipeAirGapReceiverMaxPayloadSizeInBytes();
+  }
+
   public boolean isPipeReceiverLoadConversionEnabled() {
     return COMMON_CONFIG.isPipeReceiverLoadConversionEnabled();
   }
@@ -627,6 +631,9 @@ public void printAllConfigs() {
     LOGGER.info(
         "PipeReceiverReqDecompressedMaxLengthInBytes: {}",
         getPipeReceiverReqDecompressedMaxLengthInBytes());
+    LOGGER.info(
+        "PipeAirGapReceiverMaxPayloadSizeInBytes: {}",
+        getPipeAirGapReceiverMaxPayloadSizeInBytes());
     LOGGER.info("PipeReceiverLoadConversionEnabled: {}", isPipeReceiverLoadConversionEnabled());
     LOGGER.info(
         "PipePeriodicalLogMinIntervalSeconds: {}", getPipePeriodicalLogMinIntervalSeconds());

iotdb-core/node-commons/src/main/java/org/apache/iotdb/commons/pipe/config/PipeDescriptor.java

@@ -464,6 +464,11 @@ public static void loadPipeInternalConfig(CommonConfig config, TrimProperties pr
             properties.getProperty(
                 "pipe_receiver_req_decompressed_max_length_in_bytes",
                 String.valueOf(config.getPipeReceiverReqDecompressedMaxLengthInBytes()))));
+    config.setPipeAirGapReceiverMaxPayloadSizeInBytes(
+        Integer.parseInt(
+            properties.getProperty(
+                "pipe_air_gap_receiver_max_payload_size_in_bytes",
+                String.valueOf(config.getPipeAirGapReceiverMaxPayloadSizeInBytes()))));
     config.setPipeReceiverLoadConversionEnabled(
         Boolean.parseBoolean(
             properties.getProperty(