From 2e85b3e169e30d604b1af11a7518086e5545b0ce Mon Sep 17 00:00:00 2001
From: Simone Bordet <simone.bordet@gmail.com>
Date: Tue, 14 Apr 2020 11:44:58 +0200
Subject: [PATCH] Fixes #4764 - HTTP2 Jetty Server does not send back
 content-length.

Updates after review.
Now the Content-Length header is generated by HpackEncoder based on
MetaData.contentLength, so that the MetaData.HttpFields are not modified.

Signed-off-by: Simone Bordet <simone.bordet@gmail.com>
---
 .../java/org/eclipse/jetty/http/MetaData.java    |  5 +++++
 .../eclipse/jetty/http2/hpack/HpackEncoder.java  | 14 +++++++++++++-
 .../http2/server/HttpTransportOverHTTP2.java     | 16 ++++++++++++----
 3 files changed, 30 insertions(+), 5 deletions(-)

diff --git a/jetty-http/src/main/java/org/eclipse/jetty/http/MetaData.java b/jetty-http/src/main/java/org/eclipse/jetty/http/MetaData.java
index 7591f62e291..8035b086b72 100644
--- a/jetty-http/src/main/java/org/eclipse/jetty/http/MetaData.java
+++ b/jetty-http/src/main/java/org/eclipse/jetty/http/MetaData.java
@@ -119,6 +119,11 @@ public class MetaData implements Iterable<HttpField>
         return _contentLength;
     }
 
+    public void setContentLength(long contentLength)
+    {
+        _contentLength = contentLength;
+    }
+
     /**
      * @return an iterator over the HTTP fields
      * @see #getFields()
diff --git a/jetty-http2/http2-hpack/src/main/java/org/eclipse/jetty/http2/hpack/HpackEncoder.java b/jetty-http2/http2-hpack/src/main/java/org/eclipse/jetty/http2/hpack/HpackEncoder.java
index d71df43f044..0788806b34b 100644
--- a/jetty-http2/http2-hpack/src/main/java/org/eclipse/jetty/http2/hpack/HpackEncoder.java
+++ b/jetty-http2/http2-hpack/src/main/java/org/eclipse/jetty/http2/hpack/HpackEncoder.java
@@ -217,7 +217,8 @@ public class HpackEncoder
             // Remove fields as specified in RFC 7540, 8.1.2.2.
             if (fields != null)
             {
-                // For example: Connection: Close, TE, Upgrade, Custom.
+                // Remove the headers specified in the Connection header,
+                // for example: Connection: Close, TE, Upgrade, Custom.
                 Set<String> hopHeaders = null;
                 for (String value : fields.getCSV(HttpHeader.CONNECTION, false))
                 {
@@ -225,6 +226,8 @@ public class HpackEncoder
                         hopHeaders = new HashSet<>();
                     hopHeaders.add(StringUtil.asciiToLowerCase(value));
                 }
+
+                boolean contentLengthEncoded = false;
                 for (HttpField field : fields)
                 {
                     HttpHeader header = field.getHeader();
@@ -239,8 +242,17 @@ public class HpackEncoder
                     String name = field.getLowerCaseName();
                     if (hopHeaders != null && hopHeaders.contains(name))
                         continue;
+                    if (header == HttpHeader.CONTENT_LENGTH)
+                        contentLengthEncoded = true;
                     encode(buffer, field);
                 }
+
+                if (!contentLengthEncoded)
+                {
+                    long contentLength = metadata.getContentLength();
+                    if (contentLength >= 0)
+                        encode(buffer, new HttpField(HttpHeader.CONTENT_LENGTH, String.valueOf(contentLength)));
+                }
             }
 
             // Check size
diff --git a/jetty-http2/http2-server/src/main/java/org/eclipse/jetty/http2/server/HttpTransportOverHTTP2.java b/jetty-http2/http2-server/src/main/java/org/eclipse/jetty/http2/server/HttpTransportOverHTTP2.java
index a19a8fa071e..03a9812c588 100644
--- a/jetty-http2/http2-server/src/main/java/org/eclipse/jetty/http2/server/HttpTransportOverHTTP2.java
+++ b/jetty-http2/http2-server/src/main/java/org/eclipse/jetty/http2/server/HttpTransportOverHTTP2.java
@@ -22,8 +22,8 @@ import java.nio.ByteBuffer;
 import java.util.concurrent.atomic.AtomicBoolean;
 import java.util.function.Supplier;
 
+import org.eclipse.jetty.http.BadMessageException;
 import org.eclipse.jetty.http.HttpFields;
-import org.eclipse.jetty.http.HttpHeader;
 import org.eclipse.jetty.http.HttpStatus;
 import org.eclipse.jetty.http.HttpVersion;
 import org.eclipse.jetty.http.MetaData;
@@ -113,9 +113,17 @@ public class HttpTransportOverHTTP2 implements HttpTransport
                 {
                     if (lastContent)
                     {
-                        HttpFields responseHeaders = info.getFields();
-                        if (!responseHeaders.contains(HttpHeader.CONTENT_LENGTH))
-                            responseHeaders.put(HttpHeader.CONTENT_LENGTH, String.valueOf(BufferUtil.length(content)));
+                        long realContentLength = BufferUtil.length(content);
+                        long contentLength = info.getContentLength();
+                        if (contentLength < 0)
+                        {
+                            info.setContentLength(realContentLength);
+                        }
+                        else if (contentLength != realContentLength)
+                        {
+                            callback.failed(new BadMessageException(HttpStatus.INTERNAL_SERVER_ERROR_500, String.format("Incorrect Content-Length %d!=%d", contentLength, realContentLength)));
+                            return;
+                        }
                     }
 
                     if (hasContent)