content/browser/loader/resource

/* [<][>][^][v][top][bottom][index][help] */
This source file includes following definitions.
PopulateResourceResponse
weak_ptr_factory_
StartRequest
CancelRequest
CancelAndIgnore
CancelWithError
ReportUploadProgress
MarkAsTransferring
CompleteTransfer
GetRequestInfo
ClearLoginDelegate
ClearSSLClientAuthHandler
OnUploadProgressACK
OnReceivedRedirect
OnAuthRequired
OnCertificateRequested
OnSSLCertificateError
OnBeforeNetworkStart
OnResponseStarted
OnReadCompleted
CancelSSLRequest
ContinueSSLRequest
Resume
Cancel
StartRequestInternal
CancelRequestInternal
StoreSignedCertificateTimestamps
CompleteResponseStarted
StartReading
ResumeReading
ReadMore
CompleteRead
ResponseCompleted
CallDidFinishLoading
RecordHistograms
// 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/loader/resource_loader.h"

#include "base/command_line.h"
#include "base/message_loop/message_loop.h"
#include "base/metrics/histogram.h"
#include "base/time/time.h"
#include "content/browser/appcache/appcache_interceptor.h"
#include "content/browser/child_process_security_policy_impl.h"
#include "content/browser/loader/cross_site_resource_handler.h"
#include "content/browser/loader/detachable_resource_handler.h"
#include "content/browser/loader/resource_loader_delegate.h"
#include "content/browser/loader/resource_request_info_impl.h"
#include "content/browser/ssl/ssl_client_auth_handler.h"
#include "content/browser/ssl/ssl_manager.h"
#include "content/common/ssl_status_serialization.h"
#include "content/public/browser/cert_store.h"
#include "content/public/browser/resource_context.h"
#include "content/public/browser/resource_dispatcher_host_login_delegate.h"
#include "content/public/browser/signed_certificate_timestamp_store.h"
#include "content/public/common/content_client.h"
#include "content/public/common/content_switches.h"
#include "content/public/common/process_type.h"
#include "content/public/common/resource_response.h"
#include "net/base/io_buffer.h"
#include "net/base/load_flags.h"
#include "net/http/http_response_headers.h"
#include "net/ssl/client_cert_store.h"
#include "net/url_request/url_request_status.h"

using base::TimeDelta;
using base::TimeTicks;

namespace content {
namespace {

void PopulateResourceResponse(net::URLRequest* request,
                              ResourceResponse* response) {
  response->head.error_code = request->status().error();
  response->head.request_time = request->request_time();
  response->head.response_time = request->response_time();
  response->head.headers = request->response_headers();
  request->GetCharset(&response->head.charset);
  response->head.content_length = request->GetExpectedContentSize();
  request->GetMimeType(&response->head.mime_type);
  net::HttpResponseInfo response_info = request->response_info();
  response->head.was_fetched_via_spdy = response_info.was_fetched_via_spdy;
  response->head.was_npn_negotiated = response_info.was_npn_negotiated;
  response->head.npn_negotiated_protocol =
      response_info.npn_negotiated_protocol;
  response->head.connection_info = response_info.connection_info;
  response->head.was_fetched_via_proxy = request->was_fetched_via_proxy();
  response->head.socket_address = request->GetSocketAddress();
  AppCacheInterceptor::GetExtraResponseInfo(
      request,
      &response->head.appcache_id,
      &response->head.appcache_manifest_url);
  // TODO(mmenke):  Figure out if LOAD_ENABLE_LOAD_TIMING is safe to remove.
  if (request->load_flags() & net::LOAD_ENABLE_LOAD_TIMING)
    request->GetLoadTimingInfo(&response->head.load_timing);
}

}  // namespace

ResourceLoader::ResourceLoader(scoped_ptr<net::URLRequest> request,
                               scoped_ptr<ResourceHandler> handler,
                               ResourceLoaderDelegate* delegate)
    : deferred_stage_(DEFERRED_NONE),
      request_(request.Pass()),
      handler_(handler.Pass()),
      delegate_(delegate),
      last_upload_position_(0),
      waiting_for_upload_progress_ack_(false),
      is_transferring_(false),
      weak_ptr_factory_(this) {
  request_->set_delegate(this);
  handler_->SetController(this);
}

ResourceLoader::~ResourceLoader() {
  if (login_delegate_.get())
    login_delegate_->OnRequestCancelled();
  if (ssl_client_auth_handler_.get())
    ssl_client_auth_handler_->OnRequestCancelled();

  // Run ResourceHandler destructor before we tear-down the rest of our state
  // as the ResourceHandler may want to inspect the URLRequest and other state.
  handler_.reset();
}

void ResourceLoader::StartRequest() {
  if (delegate_->HandleExternalProtocol(this, request_->url())) {
    CancelAndIgnore();
    return;
  }

  // Give the handler a chance to delay the URLRequest from being started.
  bool defer_start = false;
  if (!handler_->OnWillStart(GetRequestInfo()->GetRequestID(), request_->url(),
                             &defer_start)) {
    Cancel();
    return;
  }

  if (defer_start) {
    deferred_stage_ = DEFERRED_START;
  } else {
    StartRequestInternal();
  }
}

void ResourceLoader::CancelRequest(bool from_renderer) {
  CancelRequestInternal(net::ERR_ABORTED, from_renderer);
}

void ResourceLoader::CancelAndIgnore() {
  ResourceRequestInfoImpl* info = GetRequestInfo();
  info->set_was_ignored_by_handler(true);
  CancelRequest(false);
}

void ResourceLoader::CancelWithError(int error_code) {
  CancelRequestInternal(error_code, false);
}

void ResourceLoader::ReportUploadProgress() {
  ResourceRequestInfoImpl* info = GetRequestInfo();

  if (waiting_for_upload_progress_ack_)
    return;  // Send one progress event at a time.

  net::UploadProgress progress = request_->GetUploadProgress();
  if (!progress.size())
    return;  // Nothing to upload.

  if (progress.position() == last_upload_position_)
    return;  // No progress made since last time.

  const uint64 kHalfPercentIncrements = 200;
  const TimeDelta kOneSecond = TimeDelta::FromMilliseconds(1000);

  uint64 amt_since_last = progress.position() - last_upload_position_;
  TimeDelta time_since_last = TimeTicks::Now() - last_upload_ticks_;

  bool is_finished = (progress.size() == progress.position());
  bool enough_new_progress =
      (amt_since_last > (progress.size() / kHalfPercentIncrements));
  bool too_much_time_passed = time_since_last > kOneSecond;

  if (is_finished || enough_new_progress || too_much_time_passed) {
    if (request_->load_flags() & net::LOAD_ENABLE_UPLOAD_PROGRESS) {
      handler_->OnUploadProgress(
          info->GetRequestID(), progress.position(), progress.size());
      waiting_for_upload_progress_ack_ = true;
    }
    last_upload_ticks_ = TimeTicks::Now();
    last_upload_position_ = progress.position();
  }
}

void ResourceLoader::MarkAsTransferring() {
  CHECK(ResourceType::IsFrame(GetRequestInfo()->GetResourceType()))
      << "Can only transfer for navigations";
  is_transferring_ = true;
}

void ResourceLoader::CompleteTransfer() {
  DCHECK_EQ(DEFERRED_READ, deferred_stage_);

  is_transferring_ = false;
  GetRequestInfo()->cross_site_handler()->ResumeResponse();
}

ResourceRequestInfoImpl* ResourceLoader::GetRequestInfo() {
  return ResourceRequestInfoImpl::ForRequest(request_.get());
}

void ResourceLoader::ClearLoginDelegate() {
  login_delegate_ = NULL;
}

void ResourceLoader::ClearSSLClientAuthHandler() {
  ssl_client_auth_handler_ = NULL;
}

void ResourceLoader::OnUploadProgressACK() {
  waiting_for_upload_progress_ack_ = false;
}

void ResourceLoader::OnReceivedRedirect(net::URLRequest* unused,
                                        const GURL& new_url,
                                        bool* defer) {
  DCHECK_EQ(request_.get(), unused);

  VLOG(1) << "OnReceivedRedirect: " << request_->url().spec();
  DCHECK(request_->status().is_success());

  ResourceRequestInfoImpl* info = GetRequestInfo();

  if (info->GetProcessType() != PROCESS_TYPE_PLUGIN &&
      !ChildProcessSecurityPolicyImpl::GetInstance()->
          CanRequestURL(info->GetChildID(), new_url)) {
    VLOG(1) << "Denied unauthorized request for "
            << new_url.possibly_invalid_spec();

    // Tell the renderer that this request was disallowed.
    Cancel();
    return;
  }

  delegate_->DidReceiveRedirect(this, new_url);

  if (delegate_->HandleExternalProtocol(this, new_url)) {
    // The request is complete so we can remove it.
    CancelAndIgnore();
    return;
  }

  scoped_refptr<ResourceResponse> response(new ResourceResponse());
  PopulateResourceResponse(request_.get(), response.get());

  if (!handler_->OnRequestRedirected(
          info->GetRequestID(), new_url, response.get(), defer)) {
    Cancel();
  } else if (*defer) {
    deferred_stage_ = DEFERRED_REDIRECT;  // Follow redirect when resumed.
  }
}

void ResourceLoader::OnAuthRequired(net::URLRequest* unused,
                                    net::AuthChallengeInfo* auth_info) {
  DCHECK_EQ(request_.get(), unused);

  if (request_->load_flags() & net::LOAD_DO_NOT_PROMPT_FOR_LOGIN) {
    request_->CancelAuth();
    return;
  }

  // Create a login dialog on the UI thread to get authentication data, or pull
  // from cache and continue on the IO thread.

  DCHECK(!login_delegate_.get())
      << "OnAuthRequired called with login_delegate pending";
  login_delegate_ = delegate_->CreateLoginDelegate(this, auth_info);
  if (!login_delegate_.get())
    request_->CancelAuth();
}

void ResourceLoader::OnCertificateRequested(
    net::URLRequest* unused,
    net::SSLCertRequestInfo* cert_info) {
  DCHECK_EQ(request_.get(), unused);

  if (request_->load_flags() & net::LOAD_PREFETCH) {
    request_->Cancel();
    return;
  }

  DCHECK(!ssl_client_auth_handler_.get())
      << "OnCertificateRequested called with ssl_client_auth_handler pending";
  ssl_client_auth_handler_ = new SSLClientAuthHandler(
      GetRequestInfo()->GetContext()->CreateClientCertStore(),
      request_.get(),
      cert_info);
  ssl_client_auth_handler_->SelectCertificate();
}

void ResourceLoader::OnSSLCertificateError(net::URLRequest* request,
                                           const net::SSLInfo& ssl_info,
                                           bool fatal) {
  ResourceRequestInfoImpl* info = GetRequestInfo();

  int render_process_id;
  int render_frame_id;
  if (!info->GetAssociatedRenderFrame(&render_process_id, &render_frame_id))
    NOTREACHED();

  SSLManager::OnSSLCertificateError(
      weak_ptr_factory_.GetWeakPtr(),
      info->GetGlobalRequestID(),
      info->GetResourceType(),
      request_->url(),
      render_process_id,
      render_frame_id,
      ssl_info,
      fatal);
}

void ResourceLoader::OnBeforeNetworkStart(net::URLRequest* unused,
                                          bool* defer) {
  DCHECK_EQ(request_.get(), unused);

  // Give the handler a chance to delay the URLRequest from using the network.
  if (!handler_->OnBeforeNetworkStart(
           GetRequestInfo()->GetRequestID(), request_->url(), defer)) {
    Cancel();
    return;
  } else if (*defer) {
    deferred_stage_ = DEFERRED_NETWORK_START;
  }
}

void ResourceLoader::OnResponseStarted(net::URLRequest* unused) {
  DCHECK_EQ(request_.get(), unused);

  VLOG(1) << "OnResponseStarted: " << request_->url().spec();

  // The CanLoadPage check should take place after any server redirects have
  // finished, at the point in time that we know a page will commit in the
  // renderer process.
  ResourceRequestInfoImpl* info = GetRequestInfo();
  ChildProcessSecurityPolicyImpl* policy =
      ChildProcessSecurityPolicyImpl::GetInstance();
  if (!policy->CanLoadPage(info->GetChildID(),
                           request_->url(),
                           info->GetResourceType())) {
    Cancel();
    return;
  }

  if (!request_->status().is_success()) {
    ResponseCompleted();
    return;
  }

  // We want to send a final upload progress message prior to sending the
  // response complete message even if we're waiting for an ack to to a
  // previous upload progress message.
  waiting_for_upload_progress_ack_ = false;
  ReportUploadProgress();

  CompleteResponseStarted();

  if (is_deferred())
    return;

  if (request_->status().is_success()) {
    StartReading(false);  // Read the first chunk.
  } else {
    ResponseCompleted();
  }
}

void ResourceLoader::OnReadCompleted(net::URLRequest* unused, int bytes_read) {
  DCHECK_EQ(request_.get(), unused);
  VLOG(1) << "OnReadCompleted: \"" << request_->url().spec() << "\""
          << " bytes_read = " << bytes_read;

  // bytes_read == -1 always implies an error.
  if (bytes_read == -1 || !request_->status().is_success()) {
    ResponseCompleted();
    return;
  }

  CompleteRead(bytes_read);

  if (is_deferred())
    return;

  if (request_->status().is_success() && bytes_read > 0) {
    StartReading(true);  // Read the next chunk.
  } else {
    ResponseCompleted();
  }
}

void ResourceLoader::CancelSSLRequest(const GlobalRequestID& id,
                                      int error,
                                      const net::SSLInfo* ssl_info) {
  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::IO));

  // The request can be NULL if it was cancelled by the renderer (as the
  // request of the user navigating to a new page from the location bar).
  if (!request_->is_pending())
    return;
  DVLOG(1) << "CancelSSLRequest() url: " << request_->url().spec();

  if (ssl_info) {
    request_->CancelWithSSLError(error, *ssl_info);
  } else {
    request_->CancelWithError(error);
  }
}

void ResourceLoader::ContinueSSLRequest(const GlobalRequestID& id) {
  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::IO));

  DVLOG(1) << "ContinueSSLRequest() url: " << request_->url().spec();

  request_->ContinueDespiteLastError();
}

void ResourceLoader::Resume() {
  DCHECK(!is_transferring_);

  DeferredStage stage = deferred_stage_;
  deferred_stage_ = DEFERRED_NONE;
  switch (stage) {
    case DEFERRED_NONE:
      NOTREACHED();
      break;
    case DEFERRED_START:
      StartRequestInternal();
      break;
    case DEFERRED_NETWORK_START:
      request_->ResumeNetworkStart();
      break;
    case DEFERRED_REDIRECT:
      request_->FollowDeferredRedirect();
      break;
    case DEFERRED_READ:
      base::MessageLoop::current()->PostTask(
          FROM_HERE,
          base::Bind(&ResourceLoader::ResumeReading,
                     weak_ptr_factory_.GetWeakPtr()));
      break;
    case DEFERRED_FINISH:
      // Delay self-destruction since we don't know how we were reached.
      base::MessageLoop::current()->PostTask(
          FROM_HERE,
          base::Bind(&ResourceLoader::CallDidFinishLoading,
                     weak_ptr_factory_.GetWeakPtr()));
      break;
  }
}

void ResourceLoader::Cancel() {
  CancelRequest(false);
}

void ResourceLoader::StartRequestInternal() {
  DCHECK(!request_->is_pending());

  if (!request_->status().is_success()) {
    return;
  }

  request_->Start();

  delegate_->DidStartRequest(this);
}

void ResourceLoader::CancelRequestInternal(int error, bool from_renderer) {
  VLOG(1) << "CancelRequestInternal: " << request_->url().spec();

  ResourceRequestInfoImpl* info = GetRequestInfo();

  // WebKit will send us a cancel for downloads since it no longer handles
  // them.  In this case, ignore the cancel since we handle downloads in the
  // browser.
  if (from_renderer && (info->IsDownload() || info->is_stream()))
    return;

  if (from_renderer && info->detachable_handler()) {
    // TODO(davidben): Fix Blink handling of prefetches so they are not
    // cancelled on navigate away and end up in the local cache.
    info->detachable_handler()->Detach();
    return;
  }

  // TODO(darin): Perhaps we should really be looking to see if the status is
  // IO_PENDING?
  bool was_pending = request_->is_pending();

  if (login_delegate_.get()) {
    login_delegate_->OnRequestCancelled();
    login_delegate_ = NULL;
  }
  if (ssl_client_auth_handler_.get()) {
    ssl_client_auth_handler_->OnRequestCancelled();
    ssl_client_auth_handler_ = NULL;
  }

  request_->CancelWithError(error);

  if (!was_pending) {
    // If the request isn't in flight, then we won't get an asynchronous
    // notification from the request, so we have to signal ourselves to finish
    // this request.
    base::MessageLoop::current()->PostTask(
        FROM_HERE,
        base::Bind(&ResourceLoader::ResponseCompleted,
                   weak_ptr_factory_.GetWeakPtr()));
  }
}

void ResourceLoader::StoreSignedCertificateTimestamps(
    const net::SignedCertificateTimestampAndStatusList& sct_list,
    int process_id,
    SignedCertificateTimestampIDStatusList* sct_ids) {
  SignedCertificateTimestampStore* sct_store(
      SignedCertificateTimestampStore::GetInstance());

  for (net::SignedCertificateTimestampAndStatusList::const_iterator iter =
       sct_list.begin(); iter != sct_list.end(); ++iter) {
    const int sct_id(sct_store->Store(iter->sct, process_id));
    sct_ids->push_back(
        SignedCertificateTimestampIDAndStatus(sct_id, iter->status));
  }
}

void ResourceLoader::CompleteResponseStarted() {
  ResourceRequestInfoImpl* info = GetRequestInfo();

  scoped_refptr<ResourceResponse> response(new ResourceResponse());
  PopulateResourceResponse(request_.get(), response.get());

  if (request_->ssl_info().cert.get()) {
    int cert_id = CertStore::GetInstance()->StoreCert(
        request_->ssl_info().cert.get(), info->GetChildID());

    SignedCertificateTimestampIDStatusList signed_certificate_timestamp_ids;
    StoreSignedCertificateTimestamps(
        request_->ssl_info().signed_certificate_timestamps,
        info->GetChildID(),
        &signed_certificate_timestamp_ids);

    response->head.security_info = SerializeSecurityInfo(
        cert_id,
        request_->ssl_info().cert_status,
        request_->ssl_info().security_bits,
        request_->ssl_info().connection_status,
        signed_certificate_timestamp_ids);
  } else {
    // We should not have any SSL state.
    DCHECK(!request_->ssl_info().cert_status &&
           request_->ssl_info().security_bits == -1 &&
           !request_->ssl_info().connection_status);
  }

  delegate_->DidReceiveResponse(this);

  bool defer = false;
  if (!handler_->OnResponseStarted(
          info->GetRequestID(), response.get(), &defer)) {
    Cancel();
  } else if (defer) {
    read_deferral_start_time_ = base::TimeTicks::Now();
    deferred_stage_ = DEFERRED_READ;  // Read first chunk when resumed.
  }
}

void ResourceLoader::StartReading(bool is_continuation) {
  int bytes_read = 0;
  ReadMore(&bytes_read);

  // If IO is pending, wait for the URLRequest to call OnReadCompleted.
  if (request_->status().is_io_pending())
    return;

  if (!is_continuation || bytes_read <= 0) {
    OnReadCompleted(request_.get(), bytes_read);
  } else {
    // Else, trigger OnReadCompleted asynchronously to avoid starving the IO
    // thread in case the URLRequest can provide data synchronously.
    base::MessageLoop::current()->PostTask(
        FROM_HERE,
        base::Bind(&ResourceLoader::OnReadCompleted,
                   weak_ptr_factory_.GetWeakPtr(),
                   request_.get(),
                   bytes_read));
  }
}

void ResourceLoader::ResumeReading() {
  DCHECK(!is_deferred());

  if (!read_deferral_start_time_.is_null()) {
    UMA_HISTOGRAM_TIMES("Net.ResourceLoader.ReadDeferral",
                        base::TimeTicks::Now() - read_deferral_start_time_);
    read_deferral_start_time_ = base::TimeTicks();
  }
  if (request_->status().is_success()) {
    StartReading(false);  // Read the next chunk (OK to complete synchronously).
  } else {
    ResponseCompleted();
  }
}

void ResourceLoader::ReadMore(int* bytes_read) {
  ResourceRequestInfoImpl* info = GetRequestInfo();
  DCHECK(!is_deferred());

  // Make sure we track the buffer in at least one place.  This ensures it gets
  // deleted even in the case the request has already finished its job and
  // doesn't use the buffer.
  scoped_refptr<net::IOBuffer> buf;
  int buf_size;
  if (!handler_->OnWillRead(info->GetRequestID(), &buf, &buf_size, -1)) {
    Cancel();
    return;
  }

  DCHECK(buf);
  DCHECK(buf_size > 0);

  request_->Read(buf.get(), buf_size, bytes_read);

  // No need to check the return value here as we'll detect errors by
  // inspecting the URLRequest's status.
}

void ResourceLoader::CompleteRead(int bytes_read) {
  DCHECK(bytes_read >= 0);
  DCHECK(request_->status().is_success());

  ResourceRequestInfoImpl* info = GetRequestInfo();

  bool defer = false;
  if (!handler_->OnReadCompleted(info->GetRequestID(), bytes_read, &defer)) {
    Cancel();
  } else if (defer) {
    deferred_stage_ = DEFERRED_READ;  // Read next chunk when resumed.
  }
}

void ResourceLoader::ResponseCompleted() {
  VLOG(1) << "ResponseCompleted: " << request_->url().spec();
  RecordHistograms();
  ResourceRequestInfoImpl* info = GetRequestInfo();

  std::string security_info;
  const net::SSLInfo& ssl_info = request_->ssl_info();
  if (ssl_info.cert.get() != NULL) {
    int cert_id = CertStore::GetInstance()->StoreCert(ssl_info.cert.get(),
                                                      info->GetChildID());
    SignedCertificateTimestampIDStatusList signed_certificate_timestamp_ids;
    StoreSignedCertificateTimestamps(ssl_info.signed_certificate_timestamps,
                                     info->GetChildID(),
                                     &signed_certificate_timestamp_ids);

    security_info = SerializeSecurityInfo(
        cert_id, ssl_info.cert_status, ssl_info.security_bits,
        ssl_info.connection_status, signed_certificate_timestamp_ids);
  }

  bool defer = false;
  handler_->OnResponseCompleted(info->GetRequestID(), request_->status(),
                                security_info, &defer);
  if (defer) {
    // The handler is not ready to die yet.  We will call DidFinishLoading when
    // we resume.
    deferred_stage_ = DEFERRED_FINISH;
  } else {
    // This will result in our destruction.
    CallDidFinishLoading();
  }
}

void ResourceLoader::CallDidFinishLoading() {
  delegate_->DidFinishLoading(this);
}

void ResourceLoader::RecordHistograms() {
  ResourceRequestInfoImpl* info = GetRequestInfo();

  if (info->GetResourceType() == ResourceType::PREFETCH) {
    PrefetchStatus status = STATUS_UNDEFINED;
    TimeDelta total_time = base::TimeTicks::Now() - request_->creation_time();

    switch (request_->status().status()) {
      case net::URLRequestStatus::SUCCESS:
        if (request_->was_cached()) {
          status = STATUS_SUCCESS_FROM_CACHE;
          UMA_HISTOGRAM_TIMES("Net.Prefetch.TimeSpentPrefetchingFromCache",
                              total_time);
        } else {
          status = STATUS_SUCCESS_FROM_NETWORK;
          UMA_HISTOGRAM_TIMES("Net.Prefetch.TimeSpentPrefetchingFromNetwork",
                              total_time);
        }
        break;
      case net::URLRequestStatus::CANCELED:
        status = STATUS_CANCELED;
        UMA_HISTOGRAM_TIMES("Net.Prefetch.TimeBeforeCancel", total_time);
        break;
      case net::URLRequestStatus::IO_PENDING:
      case net::URLRequestStatus::FAILED:
        status = STATUS_UNDEFINED;
        break;
    }

    UMA_HISTOGRAM_ENUMERATION("Net.Prefetch.Pattern", status, STATUS_MAX);
  }
}

}  // namespace content
/* [<][>][^][v][top][bottom][index][help] */
root/content/browser/loader/resource_loader.cc

DEFINITIONS
