OOPIFs: Transitioning MHTML generation from view-oriented to frame-oriented.

content/browser/download/mhtml_generation_manager.cc

 // Copyright (c) 2012 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.
 
 #include "content/browser/download/mhtml_generation_manager.h"
 
+#include <map>
+#include <queue>
+
 #include "base/bind.h"
 #include "base/files/file.h"
+#include "base/guid.h"
+#include "base/rand_util.h"
 #include "base/scoped_observer.h"
 #include "base/stl_util.h"
-#include "content/browser/renderer_host/render_view_host_impl.h"
+#include "base/strings/string_number_conversions.h"
+#include "base/strings/stringprintf.h"
+#include "content/browser/frame_host/frame_tree_node.h"
+#include "content/common/frame_messages.h"
 #include "content/public/browser/browser_thread.h"
 #include "content/public/browser/render_frame_host.h"
 #include "content/public/browser/render_process_host.h"
 #include "content/public/browser/render_process_host_observer.h"
 #include "content/public/browser/web_contents.h"
-#include "content/common/view_messages.h"
 
 namespace content {
 
 // The class and all of its members live on the UI thread.  Only static methods
 // are executed on other threads.
 class MHTMLGenerationManager::Job : public RenderProcessHostObserver {
  public:
   Job(int job_id, WebContents* web_contents, GenerateMHTMLCallback callback);
   ~Job() override;
 
   void set_browser_file(base::File file) { browser_file_ = file.Pass(); }
 
   GenerateMHTMLCallback callback() const { return callback_; }
 
-  // Sends IPC to the renderer, asking for MHTML generation.
+  // Sends IPC to the renderer, asking for MHTML generation of the next frame.
+  //
   // Returns true if the message was sent successfully; false otherwise.
-  bool SendToRenderView();
+  bool SendToNextRenderFrame();
+
+  // Indicates if more calls to SendToNextRenderFrame are needed.
+  bool GotMoreFramesToProcess() {

[dcheng, 2015/12/09 08:02:37]

Nit: HasMoreFramesToProcess() const?

Got sounds like the code got something in response to trying to get something
(if that makes any sense).

[Łukasz Anforowicz, 2015/12/09 17:33:57]

Makes sense.  Done.

+    return !pending_frame_tree_node_ids_.empty();
+  }
 
   // Close the file on the file thread and respond back on the UI thread with
   // file size.
   void CloseFile(base::Callback<void(int64 file_size)> callback);
 
   // RenderProcessHostObserver:
   void RenderProcessExited(RenderProcessHost* host,
                            base::TerminationStatus status,
                            int exit_code) override;
   void RenderProcessHostDestroyed(RenderProcessHost* host) override;
 
  private:
+  static std::string GenerateMhtmlBoundaryMarker();
   static int64 CloseFileOnFileThread(base::File file);
+  void AddFrame(RenderFrameHost* render_frame_host);
+
+  // Translates |frame_tree_node_to_content_id_| into
+  // a |site_instance|-specific, routing-id-based map.
+  std::map<int, std::string> CreateFrameRoutingIdToContentId(
+      SiteInstance* site_instance);
 
   // Id used to map renderer responses to jobs.
   // See also MHTMLGenerationManager::id_to_job_ map.
   int job_id_;
 
   // The handle to the file the MHTML is saved to for the browser process.
   base::File browser_file_;
 
-  // The IDs mapping to a specific contents.
-  int process_id_;
-  int routing_id_;
+  // The IDs of frames we still need to process.
+  std::queue<int> pending_frame_tree_node_ids_;
+
+  // Map from frames into content ids (see WebPageSerializer::generateMHTMLParts
+  // for more details about what "content ids" are and how they are used).
+  std::map<int, std::string> frame_tree_node_to_content_id_;
+
+  // MIME multipart boundary to use in the MHTML doc.
+  std::string mhtml_boundary_marker_;
 
   // The callback to call once generation is complete.
   GenerateMHTMLCallback callback_;
 
   // RAII helper for registering this Job as a RenderProcessHost observer.
   ScopedObserver<RenderProcessHost, MHTMLGenerationManager::Job>
       observed_renderer_process_host_;
 
   DISALLOW_COPY_AND_ASSIGN(Job);
 };
 
 MHTMLGenerationManager::Job::Job(int job_id,
                                  WebContents* web_contents,
                                  GenerateMHTMLCallback callback)
     : job_id_(job_id),
-      process_id_(web_contents->GetRenderProcessHost()->GetID()),
-      routing_id_(web_contents->GetRenderViewHost()->GetRoutingID()),
+      mhtml_boundary_marker_(GenerateMhtmlBoundaryMarker()),
       callback_(callback),
       observed_renderer_process_host_(this) {
   DCHECK_CURRENTLY_ON(BrowserThread::UI);
+  web_contents->ForEachFrame(base::Bind(
+      &MHTMLGenerationManager::Job::AddFrame,
+      base::Unretained(this)));  // Safe because ForEachFrame is synchronous.
+
+  // Main frame needs to be processed first.
+  DCHECK(!pending_frame_tree_node_ids_.empty());
+  DCHECK(FrameTreeNode::GloballyFindByID(pending_frame_tree_node_ids_.front())
+             ->parent() == nullptr);
 }
 
 MHTMLGenerationManager::Job::~Job() {
   DCHECK_CURRENTLY_ON(BrowserThread::UI);
 }
 
-bool MHTMLGenerationManager::Job::SendToRenderView() {
-  DCHECK_CURRENTLY_ON(BrowserThread::UI);
+std::map<int, std::string>
+MHTMLGenerationManager::Job::CreateFrameRoutingIdToContentId(
+    SiteInstance* site_instance) {
+  std::map<int, std::string> result;
+  for (const auto& it : frame_tree_node_to_content_id_) {
+    int ftn_id = it.first;
+    const std::string& content_id = it.second;
+
+    FrameTreeNode* ftn = FrameTreeNode::GloballyFindByID(ftn_id);
+    if (!ftn)
+      continue;
+
+    int routing_id =
+        ftn->render_manager()->GetRoutingIdForSiteInstance(site_instance);
+    if (routing_id == MSG_ROUTING_NONE)
+      continue;
+
+    result[routing_id] = content_id;
+  }
+  return result;
+}
+
+bool MHTMLGenerationManager::Job::SendToNextRenderFrame() {
   DCHECK(browser_file_.IsValid());
+  DCHECK_LT(0u, pending_frame_tree_node_ids_.size());
 
-  RenderViewHost* rvh = RenderViewHost::FromID(process_id_, routing_id_);
-  if (!rvh) {  // The contents went away.
+  int frame_tree_node_id = pending_frame_tree_node_ids_.front();
+  pending_frame_tree_node_ids_.pop();
+  bool is_last_frame = pending_frame_tree_node_ids_.empty();
+
+  FrameTreeNode* ftn = FrameTreeNode::GloballyFindByID(frame_tree_node_id);
+  if (!ftn)  // The contents went away.
     return false;
-  }
+  RenderFrameHost* rfh = ftn->current_frame_host();
 
-  observed_renderer_process_host_.Add(rvh->GetMainFrame()->GetProcess());
+  // Get notified if the target of the IPC message dies between responding.
+  observed_renderer_process_host_.RemoveAll();
+  observed_renderer_process_host_.Add(rfh->GetProcess());
 
   IPC::PlatformFileForTransit renderer_file = IPC::GetFileHandleForProcess(
-      browser_file_.GetPlatformFile(), rvh->GetProcess()->GetHandle(),
+      browser_file_.GetPlatformFile(), rfh->GetProcess()->GetHandle(),
       false);  // |close_source_handle|.
-  rvh->Send(
-      new ViewMsg_SavePageAsMHTML(rvh->GetRoutingID(), job_id_, renderer_file));
+  rfh->Send(new FrameMsg_SerializeAsMHTML(
+      rfh->GetRoutingID(), job_id_, renderer_file, mhtml_boundary_marker_,
+      CreateFrameRoutingIdToContentId(rfh->GetSiteInstance()), is_last_frame));
   return true;
 }
 
 void MHTMLGenerationManager::Job::RenderProcessExited(
     RenderProcessHost* host,
     base::TerminationStatus status,
     int exit_code) {
   DCHECK_CURRENTLY_ON(BrowserThread::UI);
   MHTMLGenerationManager::GetInstance()->RenderProcessExited(this);
 }
 
+void MHTMLGenerationManager::Job::AddFrame(RenderFrameHost* render_frame_host) {
+  auto* rfhi = static_cast<RenderFrameHostImpl*>(render_frame_host);
+  int frame_tree_node_id = rfhi->frame_tree_node()->frame_tree_node_id();
+  pending_frame_tree_node_ids_.push(frame_tree_node_id);
+
+  std::string guid = base::GenerateGUID();
+  std::string content_id = base::StringPrintf("<frame-%d-%s@mhtml.blink>",
+                                              frame_tree_node_id, guid.c_str());
+  frame_tree_node_to_content_id_[frame_tree_node_id] = content_id;
+}
+
 void MHTMLGenerationManager::Job::RenderProcessHostDestroyed(
     RenderProcessHost* host) {
   DCHECK_CURRENTLY_ON(BrowserThread::UI);
   observed_renderer_process_host_.Remove(host);
 }
 
 void MHTMLGenerationManager::Job::CloseFile(
     base::Callback<void(int64)> callback) {
   DCHECK_CURRENTLY_ON(BrowserThread::UI);
 
@@ skipping 11 matching lines @@
 
 // static
 int64 MHTMLGenerationManager::Job::CloseFileOnFileThread(base::File file) {
   DCHECK_CURRENTLY_ON(BrowserThread::FILE);
   DCHECK(file.IsValid());
   int64 file_size = file.GetLength();
   file.Close();
   return file_size;
 }
 
+// static
+std::string MHTMLGenerationManager::Job::GenerateMhtmlBoundaryMarker() {

[dcheng, 2015/12/09 08:02:37]

I think you should stick either with MHTML or Mhtml, but not both in the same
line.

(I know Mhtml is now the mandated style, but there's something to be said about
consistency)

[Łukasz Anforowicz, 2015/12/09 17:33:57]

Done.

+  // TODO(lukasza): Introduce and use a shared helper function in
+  // net/base/mime_util.h instead of having the ad-hoc code below.
+
+  // Trying to generate random boundaries similar to IE/UnMHT
+  // (ex: ----=_NextPart_000_001B_01CC157B.96F808A0).
+  const size_t kRandomValuesLength = 10;
+  uint8_t random_values[kRandomValuesLength];

[dcheng, 2015/12/09 08:02:37]

Just put 10 in here.

[Łukasz Anforowicz, 2015/12/09 17:33:57]

Done.

+  base::RandBytes(&random_values, kRandomValuesLength);

[dcheng, 2015/12/09 08:02:37]

And then use sizeof() here.

[Łukasz Anforowicz, 2015/12/09 17:33:57]

Done.

+
+  std::string result("----=_NextPart_000_");
+  result += base::HexEncode(random_values + 0, 2);
+  result += '_';
+  result += base::HexEncode(random_values + 2, 4);
+  result += '.';
+  result += base::HexEncode(random_values + 6, 4);
+  return result;
+}
+
 MHTMLGenerationManager* MHTMLGenerationManager::GetInstance() {
   return base::Singleton<MHTMLGenerationManager>::get();
 }
 
 MHTMLGenerationManager::MHTMLGenerationManager() : next_job_id_(0) {}
 
 MHTMLGenerationManager::~MHTMLGenerationManager() {
   STLDeleteValues(&id_to_job_);
 }
 
 void MHTMLGenerationManager::SaveMHTML(WebContents* web_contents,
                                        const base::FilePath& file_path,
                                        const GenerateMHTMLCallback& callback) {
   DCHECK_CURRENTLY_ON(BrowserThread::UI);
 
   int job_id = NewJob(web_contents, callback);
 
   BrowserThread::PostTaskAndReplyWithResult(
       BrowserThread::FILE, FROM_HERE,
       base::Bind(&MHTMLGenerationManager::CreateFile, file_path),
       base::Bind(&MHTMLGenerationManager::OnFileAvailable,
                  base::Unretained(this),  // Safe b/c |this| is a singleton.
                  job_id));
 }
 
 void MHTMLGenerationManager::OnSavedPageAsMHTML(
     int job_id,
     bool mhtml_generation_in_renderer_succeeded) {
   DCHECK_CURRENTLY_ON(BrowserThread::UI);
-  JobStatus job_status = mhtml_generation_in_renderer_succeeded
-                             ? JobStatus::SUCCESS
-                             : JobStatus::FAILURE;
-  JobFinished(job_id, job_status);
+
+  if (!mhtml_generation_in_renderer_succeeded) {
+    JobFinished(job_id, JobStatus::FAILURE);
+    return;
+  }
+
+  Job* job = FindJob(job_id);
+  if (!job)
+    return;
+
+  if (job->GotMoreFramesToProcess()) {
+    if (!job->SendToNextRenderFrame()) {
+      JobFinished(job_id, JobStatus::FAILURE);
+    }
+    return;
+  }
+
+  JobFinished(job_id, JobStatus::SUCCESS);
 }
 
 // static
 base::File MHTMLGenerationManager::CreateFile(const base::FilePath& file_path) {
   DCHECK_CURRENTLY_ON(BrowserThread::FILE);
-  base::File browser_file(
-      file_path, base::File::FLAG_CREATE_ALWAYS | base::File::FLAG_WRITE);
+
+  // SECURITY NOTE: A file descriptor to the file created below will be passed
+  // to multiple renderer processes which (in out-of-process iframes mode) can
+  // act on behalf of separate web principals.  Therefore it is important to
+  // only allow writing to the file and forbid reading from the file (as this
+  // would allow reading content generated by other renderers / other web
+  // principals).
+  uint32 file_flags = base::File::FLAG_CREATE_ALWAYS | base::File::FLAG_WRITE;
+
+  base::File browser_file(file_path, file_flags);
   if (!browser_file.IsValid()) {
     LOG(ERROR) << "Failed to create file to save MHTML at: " <<
         file_path.value();
   }
   return browser_file.Pass();
 }
 
 void MHTMLGenerationManager::OnFileAvailable(int job_id,
                                              base::File browser_file) {
   DCHECK_CURRENTLY_ON(BrowserThread::UI);
 
   if (!browser_file.IsValid()) {
     LOG(ERROR) << "Failed to create file";
     JobFinished(job_id, JobStatus::FAILURE);
     return;
   }
 
   Job* job = FindJob(job_id);
   if (!job)
     return;
 
   job->set_browser_file(browser_file.Pass());
 
-  if (!job->SendToRenderView()) {
+  if (!job->SendToNextRenderFrame()) {
     JobFinished(job_id, JobStatus::FAILURE);
   }
 }
 
 void MHTMLGenerationManager::JobFinished(int job_id, JobStatus job_status) {
   DCHECK_CURRENTLY_ON(BrowserThread::UI);
 
   Job* job = FindJob(job_id);
   if (!job)
     return;
@@ skipping 46 matching lines @@
        ++it) {
     if (it->second == job) {
       JobFinished(it->first, JobStatus::FAILURE);
       return;
     }
   }
   NOTREACHED();
 }
 
 }  // namespace content