content/browser/client_hints/critical_client_hints_throttle.h

// Copyright 2020 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#ifndef CONTENT_BROWSER_CLIENT_HINTS_CRITICAL_CLIENT_HINTS_THROTTLE_H_
#define CONTENT_BROWSER_CLIENT_HINTS_CRITICAL_CLIENT_HINTS_THROTTLE_H_

#include "services/network/public/mojom/url_response_head.mojom.h"
#include "third_party/blink/public/common/loader/url_loader_throttle.h"

namespace {

// These values are persisted to logs. Entries should not be renumbered and
// numeric values should never be reused.
enum class CriticalCHRestart {
  kNavigationStarted = 0,
  kHeaderPresent = 1,
  kNavigationRestarted = 2,
  kMaxValue = kNavigationRestarted,
};

// These values are persisted to logs. Entries should not be renumbered and
// numeric values should never be reused.
enum class AcceptCHFrameRestart {
  kFramePresent = 0,
  kNavigationRestarted = 1,
  kMaxValue = kNavigationRestarted,
};

}  // namespace

namespace content {

class BrowserContext;
class ClientHintsControllerDelegate;

class CriticalClientHintsThrottle : public blink::URLLoaderThrottle {
 public:
  CriticalClientHintsThrottle(
      BrowserContext* context,

      ClientHintsControllerDelegate* client_hint_delegate,
      int frame_tree_node_id);
  ~CriticalClientHintsThrottle() override = default;

  void WillProcessResponse(const GURL& response_url,
                           network::mojom::URLResponseHead* response_head,
                           bool* defer) override;

  void HandleAcceptCHFrameReceived(
      const GURL& url,
      const std::vector<network::mojom::WebClientHintsType>& accept_ch_frame)
      override;

 private:
  // Returns true if the extra `hints` are both not stored in the client hints
  // preferences and allowed to be sent to the given URL (from the given frame
  // tree node and so on). If returning true, the new name and values are added
  // to |modified_headers|.
  bool ShouldRestartWithHints(
      const GURL& url,
      const std::vector<network::mojom::WebClientHintsType>& hints,
      net::HttpRequestHeaders& modified_headers);

  BrowserContext* context_;
  ClientHintsControllerDelegate* client_hint_delegate_;
  int frame_tree_node_id_;

  // Both the ACCEPT_CH frame and the Critical-CH header should only restart a
  // navigation once. Once a redirect is triggered, the `*_redirect_` flag for
  // the feature is set to true. These ensure the navigation doesn't turn into
  // an infinite loop for their respective features (this object should stay
  // alive until the navigation is committed).
  //
  // Redirect flag for the Critical-CH header.
  bool critical_redirect_ = false;
  // Redirect flag for the ACCEPT_CH h2/3 frame.
  bool accept_ch_frame_redirect_ = false;
};

}  // namespace content

#endif  // CONTENT_BROWSER_CLIENT_HINTS_CRITICAL_CLIENT_HINTS_THROTTLE_H_