QWebEngineUrlResponseInterceptor: Implement new URL response interceptor

This patch adds the QWebEngineUrlResponseInterceptor abstract class,
which, when implemented, allows a user to intercept response headers and
modify them in any way they like.

A response interceptor can be set via
QWebEngineProfile::setUrlResponseInterceptor(),
QQuickWebEngineProfile::setUrlResponseInterceptor() or
QWebEnginePage::setUrlResponseInterceptor().

Also, the QWebEngineUrlResponseInfo class is implemented, which contains
the request and response data to be used with the response interceptor.

If a response interceptor is set in the profile and page, the one in the
profile takes precedence.

Fixes: QTBUG-61071
Change-Id: I484d14373ff597b1d531541c066f0102bae28c72
Reviewed-by: Michael Brüning <michael.bruning@qt.io>

1 files changed, 67 insertions, 0 deletions

diff --git a/src/core/net/proxying_url_loader_factory_qt.cpp b/src/core/net/proxying_url_loader_factory_qt.cpp
index 70ec61b34..aa333ae02 100644
--- a/src/core/net/proxying_url_loader_factory_qt.cpp
+++ b/src/core/net/proxying_url_loader_factory_qt.cpp
@@ -20,11 +20,14 @@
 #include "url/url_util_qt.h"
 
 #include "api/qwebengineurlrequestinfo_p.h"
+#include "api/qwebengineurlresponseinfo_p.h"
 #include "type_conversion.h"
 #include "web_contents_adapter.h"
 #include "web_contents_adapter_client.h"
 #include "web_contents_view_qt.h"
 
+#include <QtWebEngineCore/QWebEngineUrlResponseInfo>
+
 // originally based on aw_proxying_url_loader_factory.cc:
 // Copyright 2018 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
@@ -148,6 +151,11 @@ private:
     content::WebContents* webContents();
     QWebEngineUrlRequestInterceptor* getProfileInterceptor();
     QWebEngineUrlRequestInterceptor* getPageInterceptor();
+    QWebEngineUrlResponseInterceptor *getProfileResponseInterceptor();
+    QWebEngineUrlResponseInterceptor *getPageResponseInterceptor();
+
+    void interceptResponseHeaders(QWebEngineUrlResponseInterceptor *const interceptor,
+                                  net::HttpResponseHeaders *const responseHeadersPtr);
 
     QPointer<ProfileAdapter> profile_adapter_;
     const int frame_tree_node_id_;
@@ -252,6 +260,59 @@ QWebEngineUrlRequestInterceptor* InterceptedRequest::getPageInterceptor()
     return nullptr;
 }
 
+QWebEngineUrlResponseInterceptor* InterceptedRequest::getProfileResponseInterceptor()
+{
+    return profile_adapter_ ? profile_adapter_->responseInterceptor() : nullptr;
+}
+
+QWebEngineUrlResponseInterceptor* InterceptedRequest::getPageResponseInterceptor()
+{
+    if (auto wc = webContents()) {
+        auto view = static_cast<content::WebContentsImpl *>(wc)->GetView();
+        if (WebContentsAdapterClient *client = WebContentsViewQt::from(view)->client())
+            return client->webContentsAdapter()->responseInterceptor();
+    }
+    return nullptr;
+}
+
+void InterceptedRequest::interceptResponseHeaders(
+        QWebEngineUrlResponseInterceptor *const interceptor,
+        net::HttpResponseHeaders *const responseHeadersPtr)
+{
+    QHash<QByteArray, QByteArray> responseHeaders;
+    std::unordered_set<std::string> headersToRemove;
+    {
+        std::size_t iter = 0;
+        std::string name;
+        std::string value;
+        while (responseHeadersPtr->EnumerateHeaderLines(&iter, &name, &value)) {
+            responseHeaders.insert(QByteArray::fromStdString(name),
+                                   QByteArray::fromStdString(value));
+            headersToRemove.insert(name);
+        }
+    }
+
+    const QUrl requestUrl = QUrl::fromEncoded(QByteArray::fromStdString(request_.url.spec()));
+    const QHash<QByteArray, QByteArray> requestHeaders =
+            [](const net::HttpRequestHeaders &headers) {
+                QHash<QByteArray, QByteArray> result;
+                for (const auto &header : headers.GetHeaderVector()) {
+                    result.insert(QByteArray::fromStdString(header.key),
+                                  QByteArray::fromStdString(header.value));
+                }
+                return result;
+            }(request_.headers);
+
+    QWebEngineUrlResponseInfo info(requestUrl, requestHeaders, responseHeaders);
+    interceptor->interceptResponseHeaders(info);
+
+    if (info.d_ptr->isModified) {
+        responseHeadersPtr->RemoveHeaders(headersToRemove);
+        for (auto it = info.responseHeaders().cbegin(); it != info.responseHeaders().cend(); ++it)
+            responseHeadersPtr->AddHeader(it.key().toStdString(), it.value().toStdString());
+    }
+}
+
 void InterceptedRequest::Restart()
 {
     DCHECK_CURRENTLY_ON(content::BrowserThread::UI);
@@ -404,6 +465,12 @@ void InterceptedRequest::ContinueAfterIntercept()
 
 void InterceptedRequest::OnReceiveResponse(network::mojom::URLResponseHeadPtr head, mojo::ScopedDataPipeConsumerHandle handle, absl::optional<mojo_base::BigBuffer> buffer)
 {
+    QWebEngineUrlResponseInterceptor *const responseInterceptor = getProfileResponseInterceptor()
+            ? getProfileResponseInterceptor()
+            : getPageResponseInterceptor();
+    if (responseInterceptor)
+        interceptResponseHeaders(responseInterceptor, head->headers.get());
+
     current_response_ = head.Clone();
 
     target_client_->OnReceiveResponse(std::move(head), std::move(handle), std::move(buffer));