From 5cac619e237f8f71208142ad78c06a7d15b34c72 Mon Sep 17 00:00:00 2001
From: Brian Clozel <bclozel@pivotal.io>
Date: Thu, 20 Jul 2017 01:45:13 +0200
Subject: [PATCH] Fix host+port resolution in ReactorServerHttpRequest

Prior to this commit, the host+port information of the incoming request
where taken from the remoteAddress, which is actually the socket address
of the HTTP client (i.e. not the server).

This commit resolves this information from the "Host" HTTP request
header, if available, or the actual local address of the channel if no
header is available.

Issue: SPR-15084
---
 .../reactive/ReactorServerHttpRequest.java    | 40 +++++++++++++++----
 1 file changed, 32 insertions(+), 8 deletions(-)

diff --git a/spring-web/src/main/java/org/springframework/http/server/reactive/ReactorServerHttpRequest.java b/spring-web/src/main/java/org/springframework/http/server/reactive/ReactorServerHttpRequest.java
index d73e44b2df..51fb5b7239 100644
--- a/spring-web/src/main/java/org/springframework/http/server/reactive/ReactorServerHttpRequest.java
+++ b/spring-web/src/main/java/org/springframework/http/server/reactive/ReactorServerHttpRequest.java
@@ -20,6 +20,7 @@ import java.net.InetSocketAddress;
 import java.net.URI;
 import java.net.URISyntaxException;
 
+import io.netty.handler.codec.http.HttpHeaderNames;
 import io.netty.handler.codec.http.cookie.Cookie;
 import reactor.core.publisher.Flux;
 import reactor.ipc.netty.http.server.HttpServerRequest;
@@ -55,16 +56,39 @@ public class ReactorServerHttpRequest extends AbstractServerHttpRequest {
 		this.bufferFactory = bufferFactory;
 	}
 
-	private static URI initUri(HttpServerRequest channel) throws URISyntaxException {
-		Assert.notNull(channel, "'channel' must not be null");
-		InetSocketAddress address = channel.remoteAddress();
-		String requestUri = channel.uri();
-		return (address != null ? createUrl(address, requestUri) : new URI(requestUri));
+	private static URI initUri(HttpServerRequest request) throws URISyntaxException {
+		Assert.notNull(request, "'request' must not be null");
+		URI baseUri = resolveBaseUrl(request);
+		String requestUri = request.uri();
+		return (baseUri != null ? new URI(baseUri.toString() + requestUri) : new URI(requestUri));
 	}
 
-	private static URI createUrl(InetSocketAddress address, String requestUri) throws URISyntaxException {
-		URI baseUrl = new URI(null, null, address.getHostString(), address.getPort(), null, null, null);
-		return new URI(baseUrl.toString() + requestUri);
+	private static URI resolveBaseUrl(HttpServerRequest request) throws URISyntaxException {
+		String header = request.requestHeaders().get(HttpHeaderNames.HOST);
+		if (header != null) {
+			final int portIndex;
+			if (header.startsWith("[")) {
+				portIndex = header.indexOf(':', header.indexOf(']'));
+			} else {
+				portIndex = header.indexOf(':');
+			}
+			if (portIndex != -1) {
+				try {
+					return new URI(null, null, header.substring(0, portIndex),
+							Integer.parseInt(header.substring(portIndex + 1)), null, null, null);
+				} catch (NumberFormatException ignore) {
+					throw new URISyntaxException(header, "Unable to parse port", portIndex);
+				}
+			}
+			else {
+				return new URI(null, header, null, null);
+			}
+		}
+		else {
+			InetSocketAddress localAddress = (InetSocketAddress) request.context().channel().localAddress();
+			return new URI(null, null, localAddress.getHostString(),
+					localAddress.getPort(), null, null, null);
+		}
 	}
 
 	private static HttpHeaders initHeaders(HttpServerRequest channel) {