Merge pull request #13966 from ayudovin:make-max-swallow-size-easily-configurable

* pr/13966:
  Polish "Make "MaxSwallowSize" more easily configurable"
  Make "MaxSwallowSize" more easily configurable

spring-boot-project/spring-boot-autoconfigure/src/main/java/org/springframework/boot/autoconfigure/web/ServerProperties.java

@@ -329,6 +329,11 @@ public class ServerProperties {
 		 */
 		private int maxHttpHeaderSize = 0;
 
+		/**
+		 * Maximum amount of request body bytes to swallow.
+		 */
+		private int maxSwallowSize = 4096;
+
 		/**
 		 * Whether requests to the context root should be redirected by appending a / to
 		 * the path.
@@ -491,6 +496,14 @@ public class ServerProperties {
 			return this.maxHttpHeaderSize;
 		}
 
+		public int getMaxSwallowSize() {
+			return this.maxSwallowSize;
+		}
+
+		public void setMaxSwallowSize(int maxSwallowSize) {
+			this.maxSwallowSize = maxSwallowSize;
+		}
+
 		public void setMaxHttpHeaderSize(int maxHttpHeaderSize) {
 			this.maxHttpHeaderSize = maxHttpHeaderSize;
 		}

spring-boot-project/spring-boot-autoconfigure/src/main/java/org/springframework/boot/autoconfigure/web/embedded/TomcatWebServerFactoryCustomizer.java

@@ -46,6 +46,7 @@ import org.springframework.util.StringUtils;
  * @author Yulin Qin
  * @author Stephane Nicoll
  * @author Phillip Webb
+ * @author Artsiom Yudovin
  * @since 2.0.0
  */
 public class TomcatWebServerFactoryCustomizer implements
@@ -85,6 +86,8 @@ public class TomcatWebServerFactoryCustomizer implements
 		propertyMapper.from(() -> determineMaxHttpHeaderSize()).when(this::isPositive)
 				.to((maxHttpHeaderSize) -> customizeMaxHttpHeaderSize(factory,
 						maxHttpHeaderSize));
+		propertyMapper.from(tomcatProperties::getMaxSwallowSize)
+				.to((maxSwallowSize) -> customizeMaxSwallowSize(factory, maxSwallowSize));
 		propertyMapper.from(tomcatProperties::getMaxHttpPostSize)
 				.when((maxHttpPostSize) -> maxHttpPostSize != 0)
 				.to((maxHttpPostSize) -> customizeMaxHttpPostSize(factory,
@@ -216,6 +219,17 @@ public class TomcatWebServerFactoryCustomizer implements
 		});
 	}
 
+	private void customizeMaxSwallowSize(ConfigurableTomcatWebServerFactory factory,
+			int maxSwallowSize) {
+		factory.addConnectorCustomizers((connector) -> {
+			ProtocolHandler handler = connector.getProtocolHandler();
+			if (handler instanceof AbstractHttp11Protocol) {
+				AbstractHttp11Protocol<?> protocol = (AbstractHttp11Protocol<?>) handler;
+				protocol.setMaxSwallowSize(maxSwallowSize);
+			}
+		});
+	}
+
 	private void customizeMaxHttpPostSize(ConfigurableTomcatWebServerFactory factory,
 			int maxHttpPostSize) {
 		factory.addConnectorCustomizers(

spring-boot-project/spring-boot-autoconfigure/src/test/java/org/springframework/boot/autoconfigure/web/embedded/TomcatWebServerFactoryCustomizerTests.java

@@ -28,6 +28,7 @@ import org.apache.catalina.valves.ErrorReportValve;
 import org.apache.catalina.valves.RemoteIpValve;
 import org.apache.catalina.webresources.StandardRoot;
 import org.apache.coyote.AbstractProtocol;
+import org.apache.coyote.http11.AbstractHttp11Protocol;
 import org.junit.Before;
 import org.junit.Test;
 
@@ -49,6 +50,8 @@ import static org.assertj.core.api.Assertions.assertThat;
  * @author Brian Clozel
  * @author Phillip Webb
  * @author Rob Tompkins
+ * @author Artsiom Yudovin
+ * @author Stephane Nicoll
  */
 public class TomcatWebServerFactoryCustomizerTests {
 
@@ -67,6 +70,15 @@ public class TomcatWebServerFactoryCustomizerTests {
 				this.serverProperties);
 	}
 
+	@Test
+	public void defaultsAreConsistent() {
+		customizeAndRunServer((server) -> {
+			assertThat(((AbstractHttp11Protocol<?>) server.getTomcat().getConnector()
+					.getProtocolHandler()).getMaxSwallowSize()).isEqualTo(
+							this.serverProperties.getTomcat().getMaxSwallowSize());
+		});
+	}
+
 	@Test
 	public void customAcceptCount() {
 		bind("server.tomcat.accept-count=10");
@@ -107,6 +119,14 @@ public class TomcatWebServerFactoryCustomizerTests {
 						.isEqualTo(10000));
 	}
 
+	@Test
+	public void customMaxSwallowSize() {
+		bind("server.tomcat.max-swallow-size=10");
+		customizeAndRunServer((server) -> assertThat(((AbstractHttp11Protocol<?>) server
+				.getTomcat().getConnector().getProtocolHandler()).getMaxSwallowSize())
+						.isEqualTo(10));
+	}
+
 	@Test
 	public void customRemoteIpValve() {
 		bind("server.tomcat.remote-ip-header=x-my-remote-ip-header",

spring-boot-project/spring-boot-docs/src/main/asciidoc/appendix-application-properties.adoc

@@ -252,6 +252,7 @@ content into your application. Rather, pick only the properties that you need.
 	server.tomcat.max-connections=0 # Maximum number of connections that the server accepts and processes at any given time.
 	server.tomcat.max-http-header-size=0 # Maximum size, in bytes, of the HTTP message header.
 	server.tomcat.max-http-post-size=0 # Maximum size, in bytes, of the HTTP post content.
+	server.tomcat.max-swallow-size=4096 # Maximum amount of request body bytes to swallow.
 	server.tomcat.max-threads=0 # Maximum number of worker threads.
 	server.tomcat.min-spare-threads=0 # Minimum number of worker threads.
 	server.tomcat.port-header=X-Forwarded-Port # Name of the HTTP header used to override the original port value.