Adds RemoteAddrRoutePredicate

RemoteAddr=127.0.0.1/24

pom.xml

@@ -81,6 +81,11 @@
 			<groupId>org.springframework.boot</groupId>
 			<artifactId>spring-boot-devtools</artifactId>
 		</dependency>
+		<dependency>
+			<groupId>commons-net</groupId>
+			<artifactId>commons-net</artifactId>
+			<version>3.5</version>
+		</dependency>
 		<dependency>
 			<groupId>org.springframework.cloud</groupId>
 			<artifactId>spring-cloud-starter-eureka</artifactId>

src/main/java/org/springframework/cloud/gateway/config/GatewayAutoConfiguration.java

@@ -40,6 +40,7 @@ import org.springframework.cloud.gateway.handler.predicate.HeaderRoutePredicate;
 import org.springframework.cloud.gateway.handler.predicate.HostRoutePredicate;
 import org.springframework.cloud.gateway.handler.predicate.MethodRoutePredicate;
 import org.springframework.cloud.gateway.handler.predicate.QueryRoutePredicate;
+import org.springframework.cloud.gateway.handler.predicate.RemoteAddrRoutePredicate;
 import org.springframework.cloud.gateway.handler.predicate.RoutePredicate;
 import org.springframework.cloud.gateway.handler.predicate.UrlRoutePredicate;
 import org.springframework.context.annotation.Bean;
@@ -163,6 +164,12 @@ public class GatewayAutoConfiguration {
 		return new QueryRoutePredicate();
 	}
 
+	@Bean(name = "RemoteAddrRoutePredicate")
+	public RemoteAddrRoutePredicate remoteAddrRoutePredicate() {
+		return new RemoteAddrRoutePredicate();
+	}
+
+
 	@Bean(name = "UrlRoutePredicate")
 	public UrlRoutePredicate urlRoutePredicate() {
 		return new UrlRoutePredicate();

src/main/java/org/springframework/cloud/gateway/handler/predicate/RemoteAddrRoutePredicate.java

@@ -0,0 +1,66 @@
+package org.springframework.cloud.gateway.handler.predicate;
+
+import java.net.InetSocketAddress;
+import java.util.ArrayList;
+import java.util.List;
+import java.util.function.Predicate;
+
+import org.apache.commons.logging.Log;
+import org.apache.commons.logging.LogFactory;
+import org.apache.commons.net.util.SubnetUtils;
+import org.springframework.http.server.reactive.ReactorServerHttpRequest;
+import org.springframework.web.server.ServerWebExchange;
+
+/**
+ * @author Spencer Gibb
+ */
+public class RemoteAddrRoutePredicate implements RoutePredicate {
+
+	private static final Log log = LogFactory.getLog(RemoteAddrRoutePredicate.class);
+
+	@Override
+	public Predicate<ServerWebExchange> apply(String source, String[] args) {
+		List<SubnetUtils> sources = new ArrayList<>();
+		addSource(sources, source);
+
+		if (args != null) {
+			for (String arg : args) {
+				addSource(sources, arg);
+			}
+		}
+
+		return exchange -> {
+			ReactorServerHttpRequest request = (ReactorServerHttpRequest) exchange.getRequest();
+			InetSocketAddress remoteAddress = request.getReactorRequest().remoteAddress();
+			String hostAddress = remoteAddress.getAddress().getHostAddress();
+			String host = exchange.getRequest().getURI().getHost();
+
+			if (!hostAddress.equals(host)) {
+				log.warn("Remote addresses didn't match " + hostAddress + " != " + host);
+			}
+
+			for (SubnetUtils subnet : sources) {
+				if (subnet.getInfo().isInRange(hostAddress)) {
+					return true;
+				}
+			}
+
+			return false;
+		};
+	}
+
+	private void addSource(List<SubnetUtils> sources, String source) {
+		boolean inclusiveHostCount = false;
+		if (!source.contains("/")) { // no netmask, add default
+			source = source + "/32";
+		}
+		if (source.endsWith("/32")) {
+			//http://stackoverflow.com/questions/2942299/converting-cidr-address-to-subnet-mask-and-network-address#answer-6858429
+			inclusiveHostCount = true;
+		}
+		//TODO: howto support ipv6 as well?
+		SubnetUtils subnetUtils = new SubnetUtils(source);
+		subnetUtils.setInclusiveHostCount(inclusiveHostCount);
+		sources.add(subnetUtils);
+	}
+}

src/test/java/org/springframework/cloud/gateway/test/GatewayIntegrationTests.java

@@ -43,7 +43,11 @@ public class GatewayIntegrationTests {
 
 	private static final String HANDLER_MAPPER_HEADER = "X-Gateway-Handler-Mapper-Class";
 	private static final String ROUTE_ID_HEADER = "X-Gateway-Route-Id";
-	public static final Duration DURATION = Duration.ofSeconds(5);
+	private static final Duration DURATION = Duration.ofSeconds(5);
+
+	static {
+		System.setProperty("java.net.preferIPv4Stack", "true");
+	}
 
 	@LocalServerPort
 	private int port;

src/test/java/org/springframework/cloud/gateway/test/GatewayTestApplication.java

@@ -53,6 +53,7 @@ public class GatewayTestApplication {
 	}
 
 	public static void main(String[] args) {
+		System.setProperty("java.net.preferIPv4Stack", "true"); //Remove when configurable
 		SpringApplication.run(GatewayTestApplication.class, args);
 	}
 }

src/test/resources/application.yml

@@ -140,6 +140,7 @@ spring:
         uri: http://httpbin.org:80
         predicates:
         - Host=**.baz.org
+        - RemoteAddr=127.0.0.1/24
         filters:
         # $\ is being used as an escape
         - RewritePath=/foo/(?<segment>.*), /$\{segment}