Added support to specify Custom Hop-By-Hop Headers

src/main/java/io/vertx/httpproxy/ProxyOptions.java

@@ -4,6 +4,12 @@
 import io.vertx.codegen.json.annotations.JsonGen;
 import io.vertx.core.json.JsonObject;
 import io.vertx.httpproxy.cache.CacheOptions;
+import java.util.ArrayList;
+import java.util.Arrays;
+import java.util.List;
+
+import static io.vertx.core.http.HttpHeaders.*;
+import static io.vertx.core.http.HttpHeaders.UPGRADE;
 
 /**
  * Proxy options.
@@ -17,15 +23,28 @@ public class ProxyOptions {
    */
   public static final boolean DEFAULT_SUPPORT_WEBSOCKET = true;
 
+  public static final List<String> DEFAULT_HOP_BY_HOP_HEADERS = new ArrayList<>(Arrays.asList(
+    CONNECTION.toString(),
+    KEEP_ALIVE.toString(),
+    PROXY_AUTHENTICATE.toString(),
+    PROXY_AUTHORIZATION.toString(),
+    TRANSFER_ENCODING.toString(),
+    UPGRADE.toString(),
+    "te",
+    "trailer"
+  ));
+
   private CacheOptions cacheOptions;
   private boolean supportWebSocket;
+  private List<String> customHopHeaders;
 
   public ProxyOptions(JsonObject json) {
     ProxyOptionsConverter.fromJson(json, this);
   }
 
   public ProxyOptions() {
     supportWebSocket = DEFAULT_SUPPORT_WEBSOCKET;
+    customHopHeaders = DEFAULT_HOP_BY_HOP_HEADERS;
   }
 
   /**
@@ -66,6 +85,30 @@ public ProxyOptions setSupportWebSocket(boolean supportWebSocket) {
     return this;
   }
 
+  /**
+   * @return custom hop-by-hop headers
+   */
+  public List<String> getCustomHopHeaders() {
+    return customHopHeaders;
+  }
+
+  /**
+   * Sets custom hop-by-hop headers, overriding the default {@code DEFAULT_HOP_BY_HOP_HEADERS} headers.
+   * <p>
+   * <b>Warning:</b> Please read the following specification before removing or modifying
+   * any hop-by-hop header:
+   * <a href="https://datatracker.ietf.org/doc/html/rfc2616#section-13.5.1">
+   * RFC 2616, Section 13.5.1
+   * </a>
+   * </p>
+   *
+   * @param customHopHeaders the list of hop-by-hop headers to set
+   */
+  public ProxyOptions setCustomHopHeaders(List<String> customHopHeaders){
+    this.customHopHeaders = customHopHeaders;
+    return this;
+  }
+
   @Override
   public String toString() {
     return toJson().toString();

src/main/java/io/vertx/httpproxy/ProxyRequest.java

@@ -21,6 +21,7 @@
 import io.vertx.core.http.HttpVersion;
 import io.vertx.core.net.HostAndPort;
 import io.vertx.httpproxy.impl.ProxiedRequest;
+import java.util.List;
 
 /**
  *
@@ -42,6 +43,18 @@ static ProxyRequest reverseProxy(HttpServerRequest proxiedRequest) {
     return new ProxiedRequest(proxiedRequest);
   }
 
+  /**
+   * Create a new {@code ProxyRequest} instance, the proxied request will be paused.
+   *
+   * @param proxiedRequest the {@code HttpServerRequest} that is proxied
+   * @param customHopHeaders list of Custom Hop-By-Hop Headers
+   * @return a reference to this, so the API can be used fluently
+   */
+  static ProxyRequest reverseProxy(HttpServerRequest proxiedRequest, List<String> customHopHeaders) {
+    proxiedRequest.pause();
+    return new ProxiedRequest(proxiedRequest, customHopHeaders);
+  }
+
   /**
    * @return the HTTP version of the proxied request
    */

src/main/java/io/vertx/httpproxy/impl/ProxiedRequest.java

@@ -23,35 +23,23 @@
 import io.vertx.core.net.HostAndPort;
 import io.vertx.core.streams.Pipe;
 import io.vertx.httpproxy.Body;
-import io.vertx.httpproxy.MediaType;
 import io.vertx.httpproxy.ProxyRequest;
 import io.vertx.httpproxy.ProxyResponse;
-
+import io.vertx.httpproxy.ProxyOptions;
 import java.util.Map;
 import java.util.Objects;
+import java.util.HashSet;
+import java.util.List;
 
-import static io.vertx.core.http.HttpHeaders.CONNECTION;
 import static io.vertx.core.http.HttpHeaders.CONTENT_LENGTH;
-import static io.vertx.core.http.HttpHeaders.KEEP_ALIVE;
-import static io.vertx.core.http.HttpHeaders.PROXY_AUTHENTICATE;
-import static io.vertx.core.http.HttpHeaders.PROXY_AUTHORIZATION;
-import static io.vertx.core.http.HttpHeaders.TRANSFER_ENCODING;
-import static io.vertx.core.http.HttpHeaders.UPGRADE;
 
 public class ProxiedRequest implements ProxyRequest {
 
   private static final CharSequence X_FORWARDED_HOST = HttpHeaders.createOptimized("x-forwarded-host");
 
-  private static final MultiMap HOP_BY_HOP_HEADERS = MultiMap.caseInsensitiveMultiMap()
-    .add(CONNECTION, "whatever")
-    .add(KEEP_ALIVE, "whatever")
-    .add(PROXY_AUTHENTICATE, "whatever")
-    .add(PROXY_AUTHORIZATION, "whatever")
-    .add("te", "whatever")
-    .add("trailer", "whatever")
-    .add(TRANSFER_ENCODING, "whatever")
-    .add(UPGRADE, "whatever");
+  private static final HashSet<String> DEFAULT_HOP_BY_HOP_HEADERS = new HashSet<>(ProxyOptions.DEFAULT_HOP_BY_HOP_HEADERS);
 
+  private final HashSet<String> HOP_BY_HOP_HEADERS;
   final ContextInternal context;
   private HttpMethod method;
   private final HttpVersion version;
@@ -88,6 +76,35 @@ public ProxiedRequest(HttpServerRequest proxiedRequest) {
     this.proxiedRequest = proxiedRequest;
     this.context = ((HttpServerRequestInternal) proxiedRequest).context();
     this.authority = null; // null is used as a signal to indicate an unchanged authority
+    this.HOP_BY_HOP_HEADERS = DEFAULT_HOP_BY_HOP_HEADERS;
+  }
+
+  public ProxiedRequest(HttpServerRequest proxiedRequest, List<String> customHopHeaders) {
+
+    // Determine content length
+    long contentLength = -1L;
+    String contentLengthHeader = proxiedRequest.getHeader(CONTENT_LENGTH);
+    if (contentLengthHeader != null) {
+      try {
+        contentLength = Long.parseLong(contentLengthHeader);
+      } catch (NumberFormatException e) {
+        // Ignore ???
+      }
+    }
+
+    // Content type
+    String contentType = proxiedRequest.getHeader(HttpHeaders.CONTENT_TYPE);
+
+    this.method = proxiedRequest.method();
+    this.version = proxiedRequest.version();
+    this.body = Body.body(proxiedRequest, contentLength, contentType);
+    this.uri = proxiedRequest.uri();
+    this.headers = MultiMap.caseInsensitiveMultiMap().addAll(proxiedRequest.headers());
+    this.absoluteURI = proxiedRequest.absoluteURI();
+    this.proxiedRequest = proxiedRequest;
+    this.context = ((HttpServerRequestInternal) proxiedRequest).context();
+    this.authority = null; // null is used as a signal to indicate an unchanged authority
+    this.HOP_BY_HOP_HEADERS = new HashSet<>(customHopHeaders);
   }
 
   @Override
@@ -173,7 +190,7 @@ Future<ProxyResponse> sendRequest() {
     for (Map.Entry<String, String> header : headers) {
       String name = header.getKey();
       String value = header.getValue();
-      if (!HOP_BY_HOP_HEADERS.contains(name) && !name.equalsIgnoreCase(HttpHeaders.HOST.toString())) {
+      if (!HOP_BY_HOP_HEADERS.contains(name)) {
         request.headers().add(name, value);
       }
     }

src/main/java/io/vertx/httpproxy/impl/ReverseProxy.java

@@ -38,6 +38,7 @@ public class ReverseProxy implements HttpProxy {
   private final boolean supportWebSocket;
   private OriginRequestProvider originRequestProvider = (pc) -> Future.failedFuture("No origin available");
   private final List<ProxyInterceptorEntry> interceptors = new ArrayList<>();
+  private final List<String> hopByHopHeaders;
 
   public ReverseProxy(ProxyOptions options, HttpClient client) {
     CacheOptions cacheOptions = options.getCacheOptions();
@@ -47,6 +48,7 @@ public ReverseProxy(ProxyOptions options, HttpClient client) {
     }
     this.client = client;
     this.supportWebSocket = options.getSupportWebSocket();
+    this.hopByHopHeaders = options.getCustomHopHeaders();
   }
 
   public Cache newCache(CacheOptions options, Vertx vertx) {
@@ -73,7 +75,7 @@ public HttpProxy addInterceptor(ProxyInterceptor interceptor, boolean supportsWe
 
   @Override
   public void handle(HttpServerRequest request) {
-    ProxyRequest proxyRequest = ProxyRequest.reverseProxy(request);
+    ProxyRequest proxyRequest = ProxyRequest.reverseProxy(request, hopByHopHeaders);
 
     // Encoding sanity check
     Boolean chunked = HttpUtils.isChunked(request.headers());