content/browser/preloading/speculation_rules/speculation_host_impl.cc

// Copyright 2021 The Chromium Authors
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#include "content/browser/preloading/speculation_rules/speculation_host_impl.h"

#include <functional>

#include "content/browser/preloading/prefetch/prefetch_document_manager.h"
#include "content/browser/preloading/preloading_decider.h"
#include "third_party/blink/public/common/features.h"

namespace content {

namespace {

bool CandidatesAreValid(
    std::vector<blink::mojom::SpeculationCandidatePtr>& candidates) {
  for (const auto& candidate : candidates) {
    // These non-http candidates should be filtered out in Blink and
    // SpeculationHostImpl should not see them. If SpeculationHostImpl receives
    // non-http candidates, it may mean the renderer process has a bug
    // or is compromised.
    if (!candidate->url.SchemeIsHTTPOrHTTPS()) {
      mojo::ReportBadMessage("SH_NON_HTTP");
      return false;
    }

    // `target_browsing_context_name_hint` on non-prerender actions should be
    // filtered out in Blink.
    if (candidate->action != blink::mojom::SpeculationAction::kPrerender &&
        candidate->target_browsing_context_name_hint !=
            blink::mojom::SpeculationTargetHint::kNoHint) {
      mojo::ReportBadMessage("SH_TARGET_HINT_ON_PREFETCH");
      return false;
    }
  }
  return true;
}

}  // namespace

// static
void SpeculationHostImpl::Bind(
    RenderFrameHost* frame_host,
    mojo::PendingReceiver<blink::mojom::SpeculationHost> receiver) {
  CHECK(frame_host);
  // DocumentService will destroy this on pipe closure or frame destruction.
  new SpeculationHostImpl(*frame_host, std::move(receiver));
}

SpeculationHostImpl::SpeculationHostImpl(
    RenderFrameHost& frame_host,
    mojo::PendingReceiver<blink::mojom::SpeculationHost> receiver)
    : DocumentService(frame_host, std::move(receiver)) {}

SpeculationHostImpl::~SpeculationHostImpl() = default;

// TODO(crbug/1384419): Add devtools_navigation_token to the preloading related
// CDPs for Devtools.
void SpeculationHostImpl::UpdateSpeculationCandidates(
    const base::UnguessableToken& devtools_navigation_token,
    std::vector<blink::mojom::SpeculationCandidatePtr> candidates) {
  DCHECK_CALLED_ON_VALID_THREAD(thread_checker_);
  if (!CandidatesAreValid(candidates))
    return;

  // Only handle messages from an active main frame.
  if (!render_frame_host().IsActive())
    return;
  if (render_frame_host().GetParent())
    return;

  if (!devtools_navigation_token_.has_value()) {
    devtools_navigation_token_ = devtools_navigation_token;
  } else if (devtools_navigation_token_.value() != devtools_navigation_token) {
    // A renderer should send the same devtools navigation token every time.
    mojo::ReportBadMessage("SH_INVALID_DEVTOOLS_TOKEN");
    return;
  }

  auto* preloading_decider =
      PreloadingDecider::GetOrCreateForCurrentDocument(&render_frame_host());
  preloading_decider->UpdateSpeculationCandidates(devtools_navigation_token,
                                                  candidates);
}

void SpeculationHostImpl::EnableNoVarySearchSupport() {
  auto* prefetch_document_manager =
      PrefetchDocumentManager::GetOrCreateForCurrentDocument(
          &render_frame_host());
  DCHECK(prefetch_document_manager);
  prefetch_document_manager->EnableNoVarySearchSupport();
}

}  // namespace content