Add configuration property for RemoteIpValve's trusted proxies

See gh-31576

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

@@ -966,6 +966,11 @@ public class ServerProperties {
 					+ "172\\.2[0-9]{1}\\.\\d{1,3}\\.\\d{1,3}|172\\.3[0-1]{1}\\.\\d{1,3}\\.\\d{1,3}|" //
 					+ "0:0:0:0:0:0:0:1|::1";
 
+			/**
+			 * Regular expression defining proxies that are trusted when they appear in the remoteIpHeader header.
+			 */
+			private String trustedProxies;
+
 			/**
 			 * Header that holds the incoming protocol, usually named "X-Forwarded-Proto".
 			 */
@@ -1041,6 +1046,13 @@ public class ServerProperties {
 				this.remoteIpHeader = remoteIpHeader;
 			}
 
+			public String getTrustedProxies() {
+				return trustedProxies;
+			}
+
+			public void setTrustedProxies(String trustedProxies) {
+				this.trustedProxies = trustedProxies;
+			}
 		}
 
 	}

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

@@ -229,6 +229,7 @@ public class TomcatWebServerFactoryCustomizer
 			}
 			// The internal proxies default to a list of "safe" internal IP addresses
 			valve.setInternalProxies(remoteIpProperties.getInternalProxies());
+			valve.setTrustedProxies(remoteIpProperties.getTrustedProxies());
 			try {
 				valve.setHostHeader(remoteIpProperties.getHostHeader());
 			}

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

@@ -129,6 +129,7 @@ class ServerPropertiesTests {
 		map.put("server.tomcat.remoteip.protocol-header", "X-Forwarded-Protocol");
 		map.put("server.tomcat.remoteip.remote-ip-header", "Remote-Ip");
 		map.put("server.tomcat.remoteip.internal-proxies", "10\\.\\d{1,3}\\.\\d{1,3}\\.\\d{1,3}");
+		map.put("server.tomcat.remoteip.trusted-proxies", "proxy1|proxy2|proxy3");
 		map.put("server.tomcat.reject-illegal-header", "false");
 		map.put("server.tomcat.background-processor-delay", "10");
 		map.put("server.tomcat.relaxed-path-chars", "|,<");
@@ -152,6 +153,7 @@ class ServerPropertiesTests {
 		assertThat(tomcat.getRemoteip().getRemoteIpHeader()).isEqualTo("Remote-Ip");
 		assertThat(tomcat.getRemoteip().getProtocolHeader()).isEqualTo("X-Forwarded-Protocol");
 		assertThat(tomcat.getRemoteip().getInternalProxies()).isEqualTo("10\\.\\d{1,3}\\.\\d{1,3}\\.\\d{1,3}");
+		assertThat(tomcat.getRemoteip().getTrustedProxies()).isEqualTo("proxy1|proxy2|proxy3");
 		assertThat(tomcat.isRejectIllegalHeader()).isFalse();
 		assertThat(tomcat.getBackgroundProcessorDelay()).hasSeconds(10);
 		assertThat(tomcat.getRelaxedPathChars()).containsExactly('|', '<');

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

@@ -224,6 +224,7 @@ class TomcatWebServerFactoryCustomizerTests {
 		bind("server.tomcat.remoteip.remote-ip-header=x-my-remote-ip-header",
 				"server.tomcat.remoteip.protocol-header=x-my-protocol-header",
 				"server.tomcat.remoteip.internal-proxies=192.168.0.1",
+				"server.tomcat.remoteip.trusted-proxies=proxy1|proxy2",
 				"server.tomcat.remoteip.host-header=x-my-forward-host",
 				"server.tomcat.remoteip.port-header=x-my-forward-port",
 				"server.tomcat.remoteip.protocol-header-https-value=On");
@@ -238,6 +239,7 @@ class TomcatWebServerFactoryCustomizerTests {
 		assertThat(remoteIpValve.getHostHeader()).isEqualTo("x-my-forward-host");
 		assertThat(remoteIpValve.getPortHeader()).isEqualTo("x-my-forward-port");
 		assertThat(remoteIpValve.getInternalProxies()).isEqualTo("192.168.0.1");
+		assertThat(remoteIpValve.getTrustedProxies()).isEqualTo("proxy1|proxy2");
 	}
 
 	@Test