From 8090a52f5ceb201b22798b3a2136c4e064b26647 Mon Sep 17 00:00:00 2001
From: rstoyanchev <rstoyanchev@vmware.com>
Date: Thu, 30 Nov 2023 13:10:06 +0000
Subject: [PATCH] ForwardedHeaderFilter supports ERROR requestUri attribute

Closes gh-30828
---
 .../web/filter/ForwardedHeaderFilter.java     | 38 +++++++++++++++++++
 .../filter/ForwardedHeaderFilterTests.java    | 23 ++++++++++-
 2 files changed, 60 insertions(+), 1 deletion(-)

diff --git a/spring-web/src/main/java/org/springframework/web/filter/ForwardedHeaderFilter.java b/spring-web/src/main/java/org/springframework/web/filter/ForwardedHeaderFilter.java
index 3b4bc005d60..a03c188cac4 100644
--- a/spring-web/src/main/java/org/springframework/web/filter/ForwardedHeaderFilter.java
+++ b/spring-web/src/main/java/org/springframework/web/filter/ForwardedHeaderFilter.java
@@ -27,6 +27,7 @@ import java.util.function.Supplier;
 
 import jakarta.servlet.FilterChain;
 import jakarta.servlet.ServletException;
+import jakarta.servlet.ServletRequest;
 import jakarta.servlet.http.HttpServletRequest;
 import jakarta.servlet.http.HttpServletRequestWrapper;
 import jakarta.servlet.http.HttpServletResponse;
@@ -37,12 +38,14 @@ import org.springframework.http.HttpStatus;
 import org.springframework.http.server.ServerHttpRequest;
 import org.springframework.http.server.ServletServerHttpRequest;
 import org.springframework.lang.Nullable;
+import org.springframework.util.Assert;
 import org.springframework.util.LinkedCaseInsensitiveMap;
 import org.springframework.util.StringUtils;
 import org.springframework.web.util.ForwardedHeaderUtils;
 import org.springframework.web.util.UriComponents;
 import org.springframework.web.util.UriComponentsBuilder;
 import org.springframework.web.util.UrlPathHelper;
+import org.springframework.web.util.WebUtils;
 
 /**
  * Extract values from "Forwarded" and "X-Forwarded-*" headers, wrap the request
@@ -312,6 +315,15 @@ public class ForwardedHeaderFilter extends OncePerRequestFilter {
 		public int getRemotePort() {
 			return (this.remoteAddress != null ? this.remoteAddress.getPort() : super.getRemotePort());
 		}
+
+		@SuppressWarnings("DataFlowIssue")
+		@Override
+		public Object getAttribute(String name) {
+			if (name.equals(WebUtils.ERROR_REQUEST_URI_ATTRIBUTE)) {
+				return this.forwardedPrefixExtractor.getErrorRequestUri();
+			}
+			return super.getAttribute(name);
+		}
 	}
 
 
@@ -419,6 +431,17 @@ public class ForwardedHeaderFilter extends OncePerRequestFilter {
 				this.requestUrl = initRequestUrl();
 			}
 		}
+
+		@Nullable
+		public String getErrorRequestUri() {
+			HttpServletRequest request = this.delegate.get();
+			String requestUri = (String) request.getAttribute(WebUtils.ERROR_REQUEST_URI_ATTRIBUTE);
+			if (this.forwardedPrefix == null || requestUri == null) {
+				return requestUri;
+			}
+			ErrorPathRequest errorRequest = new ErrorPathRequest(request);
+			return this.forwardedPrefix + UrlPathHelper.rawPathInstance.getPathWithinApplication(errorRequest);
+		}
 	}
 
 
@@ -473,4 +496,19 @@ public class ForwardedHeaderFilter extends OncePerRequestFilter {
 		}
 	}
 
+
+	private static class ErrorPathRequest extends HttpServletRequestWrapper {
+
+		ErrorPathRequest(ServletRequest request) {
+			super((HttpServletRequest) request);
+		}
+
+		@Override
+		public String getRequestURI() {
+			String requestUri = (String) getAttribute(WebUtils.ERROR_REQUEST_URI_ATTRIBUTE);
+			Assert.isTrue(requestUri != null, "Expected ERROR requestUri attribute");
+			return requestUri;
+		}
+	}
+
 }
diff --git a/spring-web/src/test/java/org/springframework/web/filter/ForwardedHeaderFilterTests.java b/spring-web/src/test/java/org/springframework/web/filter/ForwardedHeaderFilterTests.java
index bf4a4c722ff..b421d0c9c61 100644
--- a/spring-web/src/test/java/org/springframework/web/filter/ForwardedHeaderFilterTests.java
+++ b/spring-web/src/test/java/org/springframework/web/filter/ForwardedHeaderFilterTests.java
@@ -35,6 +35,7 @@ import org.junit.jupiter.params.provider.ValueSource;
 import org.springframework.web.testfixture.servlet.MockFilterChain;
 import org.springframework.web.testfixture.servlet.MockHttpServletRequest;
 import org.springframework.web.testfixture.servlet.MockHttpServletResponse;
+import org.springframework.web.util.WebUtils;
 
 import static org.assertj.core.api.Assertions.assertThat;
 import static org.assertj.core.api.Assertions.assertThatIllegalArgumentException;
@@ -187,7 +188,7 @@ public class ForwardedHeaderFilterTests {
 	}
 
 	@Test // SPR-16983
-	public void forwardedRequestWithServletForward() throws Exception {
+	public void forwardedRequestWithForwardDispatch() throws Exception {
 		this.request.setRequestURI("/foo");
 		this.request.addHeader(X_FORWARDED_PROTO, "https");
 		this.request.addHeader(X_FORWARDED_HOST, "www.mycompany.example");
@@ -208,6 +209,26 @@ public class ForwardedHeaderFilterTests {
 		assertThat(actual.getRequestURL().toString()).isEqualTo("https://www.mycompany.example/bar");
 	}
 
+	@Test // gh-30828
+	public void forwardedRequestWithErrorDispatch() throws Exception {
+		this.request.setRequestURI("/foo");
+		this.request.setDispatcherType(DispatcherType.ERROR);
+		this.request.addHeader(X_FORWARDED_PROTO, "https");
+		this.request.addHeader(X_FORWARDED_HOST, "www.mycompany.example");
+		this.request.addHeader(X_FORWARDED_PORT, "443");
+		this.request.addHeader(X_FORWARDED_PREFIX, "/app");
+		this.request.setAttribute(WebUtils.ERROR_REQUEST_URI_ATTRIBUTE, "/foo");
+
+		this.filter.doFilter(this.request, new MockHttpServletResponse(), this.filterChain);
+
+		HttpServletRequest wrappedRequest = (HttpServletRequest) this.filterChain.getRequest();
+
+		assertThat(wrappedRequest).isNotNull();
+		assertThat(wrappedRequest.getRequestURI()).isEqualTo("/app/foo");
+		assertThat(wrappedRequest.getRequestURL().toString()).isEqualTo("https://www.mycompany.example/app/foo");
+		assertThat(wrappedRequest.getAttribute(WebUtils.ERROR_REQUEST_URI_ATTRIBUTE)).isEqualTo("/app/foo");
+	}
+
 	@Nested
 	class ForwardedPrefix {