content/browser/webui/url_data_manager_backend.cc

   1 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style license that can be
   3 // found in the LICENSE file.
   4
   5 #include "content/browser/webui/url_data_manager_backend.h"
   6
   7 #include <set>
   8
   9 #include "base/basictypes.h"
  10 #include "base/bind.h"
  11 #include "base/command_line.h"
  12 #include "base/compiler_specific.h"
  13 #include "base/debug/alias.h"
  14 #include "base/lazy_instance.h"
  15 #include "base/memory/ref_counted.h"
  16 #include "base/memory/ref_counted_memory.h"
  17 #include "base/memory/weak_ptr.h"
  18 #include "base/message_loop/message_loop.h"
  19 #include "base/profiler/scoped_tracker.h"
  20 #include "base/strings/string_util.h"
  21 #include "base/strings/stringprintf.h"
  22 #include "base/trace_event/trace_event.h"
  23 #include "content/browser/appcache/view_appcache_internals_job.h"
  24 #include "content/browser/fileapi/chrome_blob_storage_context.h"
  25 #include "content/browser/histogram_internals_request_job.h"
  26 #include "content/browser/net/view_blob_internals_job_factory.h"
  27 #include "content/browser/net/view_http_cache_job_factory.h"
  28 #include "content/browser/resource_context_impl.h"
  29 #include "content/browser/tcmalloc_internals_request_job.h"
  30 #include "content/browser/webui/shared_resources_data_source.h"
  31 #include "content/browser/webui/url_data_source_impl.h"
  32 #include "content/public/browser/browser_context.h"
  33 #include "content/public/browser/browser_thread.h"
  34 #include "content/public/browser/content_browser_client.h"
  35 #include "content/public/browser/render_process_host.h"
  36 #include "content/public/browser/resource_request_info.h"
  37 #include "content/public/common/url_constants.h"
  38 #include "net/base/io_buffer.h"
  39 #include "net/base/net_errors.h"
  40 #include "net/http/http_response_headers.h"
  41 #include "net/http/http_status_code.h"
  42 #include "net/url_request/url_request.h"
  43 #include "net/url_request/url_request_context.h"
  44 #include "net/url_request/url_request_job.h"
  45 #include "net/url_request/url_request_job_factory.h"
  46 #include "url/url_util.h"
  47
  48 namespace content {
  49
  50 namespace {
  51
  52 // TODO(tsepez) remove unsafe-eval when bidichecker_packaged.js fixed.
  53 const char kChromeURLContentSecurityPolicyHeaderBase[] =
  54     "Content-Security-Policy: script-src chrome://resources "
  55     "'self' 'unsafe-eval'; ";
  56
  57 const char kChromeURLXFrameOptionsHeader[] = "X-Frame-Options: DENY";
  58
  59 const int kNoRenderProcessId = -1;
  60
  61 bool SchemeIsInSchemes(const std::string& scheme,
  62                        const std::vector<std::string>& schemes) {
  63   return std::find(schemes.begin(), schemes.end(), scheme) != schemes.end();
  64 }
  65
  66 // Returns whether |url| passes some sanity checks and is a valid GURL.
  67 bool CheckURLIsValid(const GURL& url) {
  68   std::vector<std::string> additional_schemes;
  69   DCHECK(url.SchemeIs(kChromeDevToolsScheme) || url.SchemeIs(kChromeUIScheme) ||
  70          (GetContentClient()->browser()->GetAdditionalWebUISchemes(
  71               &additional_schemes),
  72           SchemeIsInSchemes(url.scheme(), additional_schemes)));
  73
  74   if (!url.is_valid()) {
  75     NOTREACHED();
  76     return false;
  77   }
  78
  79   return true;
  80 }
  81
  82 // Parse |url| to get the path which will be used to resolve the request. The
  83 // path is the remaining portion after the scheme and hostname.
  84 void URLToRequestPath(const GURL& url, std::string* path) {
  85   const std::string& spec = url.possibly_invalid_spec();
  86   const url::Parsed& parsed = url.parsed_for_possibly_invalid_spec();
  87   // + 1 to skip the slash at the beginning of the path.
  88   int offset = parsed.CountCharactersBefore(url::Parsed::PATH, false) + 1;
  89
  90   if (offset < static_cast<int>(spec.size()))
  91     path->assign(spec.substr(offset));
  92 }
  93
  94 // Returns a value of 'Origin:' header for the |request| if the header is set.
  95 // Otherwise returns an empty string.
  96 std::string GetOriginHeaderValue(const net::URLRequest* request) {
  97   std::string result;
  98   if (request->extra_request_headers().GetHeader(
  99           net::HttpRequestHeaders::kOrigin, &result))
 100     return result;
 101   net::HttpRequestHeaders headers;
 102   if (request->GetFullRequestHeaders(&headers))
 103     headers.GetHeader(net::HttpRequestHeaders::kOrigin, &result);
 104   return result;
 105 }
 106
 107 }  // namespace
 108
 109 // URLRequestChromeJob is a net::URLRequestJob that manages running
 110 // chrome-internal resource requests asynchronously.
 111 // It hands off URL requests to ChromeURLDataManager, which asynchronously
 112 // calls back once the data is available.
 113 class URLRequestChromeJob : public net::URLRequestJob,
 114                             public base::SupportsWeakPtr<URLRequestChromeJob> {
 115  public:
 116   // |is_incognito| set when job is generated from an incognito profile.
 117   URLRequestChromeJob(net::URLRequest* request,
 118                       net::NetworkDelegate* network_delegate,
 119                       URLDataManagerBackend* backend,
 120                       bool is_incognito);
 121
 122   // net::URLRequestJob implementation.
 123   void Start() override;
 124   void Kill() override;
 125   bool ReadRawData(net::IOBuffer* buf, int buf_size, int* bytes_read) override;
 126   bool GetMimeType(std::string* mime_type) const override;
 127   int GetResponseCode() const override;
 128   void GetResponseInfo(net::HttpResponseInfo* info) override;
 129
 130   // Used to notify that the requested data's |mime_type| is ready.
 131   void MimeTypeAvailable(const std::string& mime_type);
 132
 133   // Called by ChromeURLDataManager to notify us that the data blob is ready
 134   // for us.
 135   void DataAvailable(base::RefCountedMemory* bytes);
 136
 137   void set_mime_type(const std::string& mime_type) {
 138     mime_type_ = mime_type;
 139   }
 140
 141   void set_allow_caching(bool allow_caching) {
 142     allow_caching_ = allow_caching;
 143   }
 144
 145   void set_add_content_security_policy(bool add_content_security_policy) {
 146     add_content_security_policy_ = add_content_security_policy;
 147   }
 148
 149   void set_content_security_policy_object_source(
 150       const std::string& data) {
 151     content_security_policy_object_source_ = data;
 152   }
 153
 154   void set_content_security_policy_frame_source(
 155       const std::string& data) {
 156     content_security_policy_frame_source_ = data;
 157   }
 158
 159   void set_deny_xframe_options(bool deny_xframe_options) {
 160     deny_xframe_options_ = deny_xframe_options;
 161   }
 162
 163   void set_send_content_type_header(bool send_content_type_header) {
 164     send_content_type_header_ = send_content_type_header;
 165   }
 166
 167   void set_access_control_allow_origin(const std::string& value) {
 168     access_control_allow_origin_ = value;
 169   }
 170
 171   // Returns true when job was generated from an incognito profile.
 172   bool is_incognito() const {
 173     return is_incognito_;
 174   }
 175
 176  private:
 177   ~URLRequestChromeJob() override;
 178
 179   // Helper for Start(), to let us start asynchronously.
 180   // (This pattern is shared by most net::URLRequestJob implementations.)
 181   void StartAsync(bool allowed);
 182
 183   // Called on the UI thread to check if this request is allowed.
 184   static void CheckStoragePartitionMatches(
 185       int render_process_id,
 186       const GURL& url,
 187       const base::WeakPtr<URLRequestChromeJob>& job);
 188
 189   // Do the actual copy from data_ (the data we're serving) into |buf|.
 190   // Separate from ReadRawData so we can handle async I/O.
 191   void CompleteRead(net::IOBuffer* buf, int buf_size, int* bytes_read);
 192
 193   // The actual data we're serving.  NULL until it's been fetched.
 194   scoped_refptr<base::RefCountedMemory> data_;
 195   // The current offset into the data that we're handing off to our
 196   // callers via the Read interfaces.
 197   int data_offset_;
 198
 199   // For async reads, we keep around a pointer to the buffer that
 200   // we're reading into.
 201   scoped_refptr<net::IOBuffer> pending_buf_;
 202   int pending_buf_size_;
 203   std::string mime_type_;
 204
 205   // If true, set a header in the response to prevent it from being cached.
 206   bool allow_caching_;
 207
 208   // If true, set the Content Security Policy (CSP) header.
 209   bool add_content_security_policy_;
 210
 211   // These are used with the CSP.
 212   std::string content_security_policy_object_source_;
 213   std::string content_security_policy_frame_source_;
 214
 215   // If true, sets  the "X-Frame-Options: DENY" header.
 216   bool deny_xframe_options_;
 217
 218   // If true, sets the "Content-Type: <mime-type>" header.
 219   bool send_content_type_header_;
 220
 221   // If not empty, "Access-Control-Allow-Origin:" is set to the value of this
 222   // string.
 223   std::string access_control_allow_origin_;
 224
 225   // True when job is generated from an incognito profile.
 226   const bool is_incognito_;
 227
 228   // The backend is owned by net::URLRequestContext and always outlives us.
 229   URLDataManagerBackend* backend_;
 230
 231   base::WeakPtrFactory<URLRequestChromeJob> weak_factory_;
 232
 233   DISALLOW_COPY_AND_ASSIGN(URLRequestChromeJob);
 234 };
 235
 236 URLRequestChromeJob::URLRequestChromeJob(net::URLRequest* request,
 237                                          net::NetworkDelegate* network_delegate,
 238                                          URLDataManagerBackend* backend,
 239                                          bool is_incognito)
 240     : net::URLRequestJob(request, network_delegate),
 241       data_offset_(0),
 242       pending_buf_size_(0),
 243       allow_caching_(true),
 244       add_content_security_policy_(true),
 245       content_security_policy_object_source_("object-src 'none';"),
 246       content_security_policy_frame_source_("frame-src 'none';"),
 247       deny_xframe_options_(true),
 248       send_content_type_header_(false),
 249       is_incognito_(is_incognito),
 250       backend_(backend),
 251       weak_factory_(this) {
 252   DCHECK(backend);
 253 }
 254
 255 URLRequestChromeJob::~URLRequestChromeJob() {
 256   CHECK(!backend_->HasPendingJob(this));
 257 }
 258
 259 void URLRequestChromeJob::Start() {
 260   int render_process_id, unused;
 261   bool is_renderer_request = ResourceRequestInfo::GetRenderFrameForRequest(
 262       request_, &render_process_id, &unused);
 263   if (!is_renderer_request)
 264     render_process_id = kNoRenderProcessId;
 265   BrowserThread::PostTask(
 266       BrowserThread::UI,
 267       FROM_HERE,
 268       base::Bind(&URLRequestChromeJob::CheckStoragePartitionMatches,
 269                  render_process_id, request_->url(), AsWeakPtr()));
 270   TRACE_EVENT_ASYNC_BEGIN1("browser", "DataManager:Request", this, "URL",
 271       request_->url().possibly_invalid_spec());
 272 }
 273
 274 void URLRequestChromeJob::Kill() {
 275   backend_->RemoveRequest(this);
 276 }
 277
 278 bool URLRequestChromeJob::GetMimeType(std::string* mime_type) const {
 279   *mime_type = mime_type_;
 280   return !mime_type_.empty();
 281 }
 282
 283 int URLRequestChromeJob::GetResponseCode() const {
 284   return net::HTTP_OK;
 285 }
 286
 287 void URLRequestChromeJob::GetResponseInfo(net::HttpResponseInfo* info) {
 288   DCHECK(!info->headers.get());
 289   // Set the headers so that requests serviced by ChromeURLDataManager return a
 290   // status code of 200. Without this they return a 0, which makes the status
 291   // indistiguishable from other error types. Instant relies on getting a 200.
 292   info->headers = new net::HttpResponseHeaders("HTTP/1.1 200 OK");
 293
 294   // Determine the least-privileged content security policy header, if any,
 295   // that is compatible with a given WebUI URL, and append it to the existing
 296   // response headers.
 297   if (add_content_security_policy_) {
 298     std::string base = kChromeURLContentSecurityPolicyHeaderBase;
 299     base.append(content_security_policy_object_source_);
 300     base.append(content_security_policy_frame_source_);
 301     info->headers->AddHeader(base);
 302   }
 303
 304   if (deny_xframe_options_)
 305     info->headers->AddHeader(kChromeURLXFrameOptionsHeader);
 306
 307   if (!allow_caching_)
 308     info->headers->AddHeader("Cache-Control: no-cache");
 309
 310   if (send_content_type_header_ && !mime_type_.empty()) {
 311     std::string content_type =
 312         base::StringPrintf("%s:%s", net::HttpRequestHeaders::kContentType,
 313                            mime_type_.c_str());
 314     info->headers->AddHeader(content_type);
 315   }
 316
 317   if (!access_control_allow_origin_.empty()) {
 318     info->headers->AddHeader("Access-Control-Allow-Origin: " +
 319                              access_control_allow_origin_);
 320     info->headers->AddHeader("Vary: Origin");
 321   }
 322 }
 323
 324 void URLRequestChromeJob::MimeTypeAvailable(const std::string& mime_type) {
 325   set_mime_type(mime_type);
 326   NotifyHeadersComplete();
 327 }
 328
 329 void URLRequestChromeJob::DataAvailable(base::RefCountedMemory* bytes) {
 330   TRACE_EVENT_ASYNC_END0("browser", "DataManager:Request", this);
 331   if (bytes) {
 332     // The request completed, and we have all the data.
 333     // Clear any IO pending status.
 334     SetStatus(net::URLRequestStatus());
 335
 336     data_ = bytes;
 337     int bytes_read;
 338     if (pending_buf_.get()) {
 339       CHECK(pending_buf_->data());
 340       CompleteRead(pending_buf_.get(), pending_buf_size_, &bytes_read);
 341       pending_buf_ = NULL;
 342       NotifyReadComplete(bytes_read);
 343     }
 344   } else {
 345     // The request failed.
 346     NotifyDone(net::URLRequestStatus(net::URLRequestStatus::FAILED,
 347                                      net::ERR_FAILED));
 348   }
 349 }
 350
 351 bool URLRequestChromeJob::ReadRawData(net::IOBuffer* buf, int buf_size,
 352                                       int* bytes_read) {
 353   // TODO(vadimt): Remove ScopedTracker below once crbug.com/423948 is fixed.
 354   tracked_objects::ScopedTracker tracking_profile(
 355       FROM_HERE_WITH_EXPLICIT_FUNCTION(
 356           "423948 URLRequestChromeJob::ReadRawData"));
 357
 358   if (!data_.get()) {
 359     SetStatus(net::URLRequestStatus(net::URLRequestStatus::IO_PENDING, 0));
 360     DCHECK(!pending_buf_.get());
 361     CHECK(buf->data());
 362     pending_buf_ = buf;
 363     pending_buf_size_ = buf_size;
 364     return false;  // Tell the caller we're still waiting for data.
 365   }
 366
 367   // Otherwise, the data is available.
 368   CompleteRead(buf, buf_size, bytes_read);
 369   return true;
 370 }
 371
 372 void URLRequestChromeJob::CompleteRead(net::IOBuffer* buf, int buf_size,
 373                                        int* bytes_read) {
 374   int remaining = static_cast<int>(data_->size()) - data_offset_;
 375   if (buf_size > remaining)
 376     buf_size = remaining;
 377   if (buf_size > 0) {
 378     // TODO(pkasting): Remove ScopedTracker below once crbug.com/455423 is
 379     // fixed.
 380     tracked_objects::ScopedTracker tracking_profile(
 381         FROM_HERE_WITH_EXPLICIT_FUNCTION(
 382             "455423 URLRequestChromeJob::CompleteRead memcpy"));
 383     memcpy(buf->data(), data_->front() + data_offset_, buf_size);
 384     data_offset_ += buf_size;
 385   }
 386   *bytes_read = buf_size;
 387 }
 388
 389 void URLRequestChromeJob::CheckStoragePartitionMatches(
 390     int render_process_id,
 391     const GURL& url,
 392     const base::WeakPtr<URLRequestChromeJob>& job) {
 393   // The embedder could put some webui pages in separate storage partition.
 394   // RenderProcessHostImpl::IsSuitableHost would guard against top level pages
 395   // being in the same process. We do an extra check to guard against an
 396   // exploited renderer pretending to add them as a subframe. We skip this check
 397   // for resources.
 398   bool allowed = false;
 399   std::vector<std::string> hosts;
 400   GetContentClient()->
 401       browser()->GetAdditionalWebUIHostsToIgnoreParititionCheck(&hosts);
 402   if (url.SchemeIs(kChromeUIScheme) &&
 403       (url.SchemeIs(kChromeUIScheme) ||
 404        std::find(hosts.begin(), hosts.end(), url.host()) != hosts.end())) {
 405     allowed = true;
 406   } else if (render_process_id == kNoRenderProcessId) {
 407     // Request was not issued by renderer.
 408     allowed = true;
 409   } else {
 410     RenderProcessHost* process = RenderProcessHost::FromID(render_process_id);
 411     if (process) {
 412       StoragePartition* partition = BrowserContext::GetStoragePartitionForSite(
 413           process->GetBrowserContext(), url);
 414       allowed = partition == process->GetStoragePartition();
 415     }
 416   }
 417
 418   BrowserThread::PostTask(
 419       BrowserThread::IO,
 420       FROM_HERE,
 421       base::Bind(&URLRequestChromeJob::StartAsync, job, allowed));
 422 }
 423
 424 void URLRequestChromeJob::StartAsync(bool allowed) {
 425   if (!request_)
 426     return;
 427
 428   if (!allowed || !backend_->StartRequest(request_, this)) {
 429     NotifyStartError(net::URLRequestStatus(net::URLRequestStatus::FAILED,
 430                                            net::ERR_INVALID_URL));
 431   }
 432 }
 433
 434 namespace {
 435
 436 // Gets mime type for data that is available from |source| by |path|.
 437 // After that, notifies |job| that mime type is available. This method
 438 // should be called on the UI thread, but notification is performed on
 439 // the IO thread.
 440 void GetMimeTypeOnUI(URLDataSourceImpl* source,
 441                      const std::string& path,
 442                      const base::WeakPtr<URLRequestChromeJob>& job) {
 443   DCHECK_CURRENTLY_ON(BrowserThread::UI);
 444   std::string mime_type = source->source()->GetMimeType(path);
 445   BrowserThread::PostTask(
 446       BrowserThread::IO, FROM_HERE,
 447       base::Bind(&URLRequestChromeJob::MimeTypeAvailable, job, mime_type));
 448 }
 449
 450 }  // namespace
 451
 452 namespace {
 453
 454 class ChromeProtocolHandler
 455     : public net::URLRequestJobFactory::ProtocolHandler {
 456  public:
 457   // |is_incognito| should be set for incognito profiles.
 458   ChromeProtocolHandler(ResourceContext* resource_context,
 459                         bool is_incognito,
 460                         AppCacheServiceImpl* appcache_service,
 461                         ChromeBlobStorageContext* blob_storage_context)
 462       : resource_context_(resource_context),
 463         is_incognito_(is_incognito),
 464         appcache_service_(appcache_service),
 465         blob_storage_context_(blob_storage_context) {}
 466   ~ChromeProtocolHandler() override {}
 467
 468   net::URLRequestJob* MaybeCreateJob(
 469       net::URLRequest* request,
 470       net::NetworkDelegate* network_delegate) const override {
 471     DCHECK(request);
 472
 473     // Check for chrome://view-http-cache/*, which uses its own job type.
 474     if (ViewHttpCacheJobFactory::IsSupportedURL(request->url()))
 475       return ViewHttpCacheJobFactory::CreateJobForRequest(request,
 476                                                           network_delegate);
 477
 478     // Next check for chrome://appcache-internals/, which uses its own job type.
 479     if (request->url().SchemeIs(kChromeUIScheme) &&
 480         request->url().host() == kChromeUIAppCacheInternalsHost) {
 481       return ViewAppCacheInternalsJobFactory::CreateJobForRequest(
 482           request, network_delegate, appcache_service_);
 483     }
 484
 485     // Next check for chrome://blob-internals/, which uses its own job type.
 486     if (ViewBlobInternalsJobFactory::IsSupportedURL(request->url())) {
 487       return ViewBlobInternalsJobFactory::CreateJobForRequest(
 488           request, network_delegate, blob_storage_context_->context());
 489     }
 490
 491 #if defined(USE_TCMALLOC)
 492     // Next check for chrome://tcmalloc/, which uses its own job type.
 493     if (request->url().SchemeIs(kChromeUIScheme) &&
 494         request->url().host() == kChromeUITcmallocHost) {
 495       return new TcmallocInternalsRequestJob(request, network_delegate);
 496     }
 497 #endif
 498
 499     // Next check for chrome://histograms/, which uses its own job type.
 500     if (request->url().SchemeIs(kChromeUIScheme) &&
 501         request->url().host() == kChromeUIHistogramHost) {
 502       return new HistogramInternalsRequestJob(request, network_delegate);
 503     }
 504
 505     // Fall back to using a custom handler
 506     return new URLRequestChromeJob(
 507         request, network_delegate,
 508         GetURLDataManagerForResourceContext(resource_context_), is_incognito_);
 509   }
 510
 511   bool IsSafeRedirectTarget(const GURL& location) const override {
 512     return false;
 513   }
 514
 515  private:
 516   // These members are owned by ProfileIOData, which owns this ProtocolHandler.
 517   content::ResourceContext* const resource_context_;
 518
 519   // True when generated from an incognito profile.
 520   const bool is_incognito_;
 521   AppCacheServiceImpl* appcache_service_;
 522   ChromeBlobStorageContext* blob_storage_context_;
 523
 524   DISALLOW_COPY_AND_ASSIGN(ChromeProtocolHandler);
 525 };
 526
 527 }  // namespace
 528
 529 URLDataManagerBackend::URLDataManagerBackend()
 530     : next_request_id_(0) {
 531   URLDataSource* shared_source = new SharedResourcesDataSource();
 532   URLDataSourceImpl* source_impl =
 533       new URLDataSourceImpl(shared_source->GetSource(), shared_source);
 534   AddDataSource(source_impl);
 535 }
 536
 537 URLDataManagerBackend::~URLDataManagerBackend() {
 538   for (DataSourceMap::iterator i = data_sources_.begin();
 539        i != data_sources_.end(); ++i) {
 540     i->second->backend_ = NULL;
 541   }
 542   data_sources_.clear();
 543 }
 544
 545 // static
 546 net::URLRequestJobFactory::ProtocolHandler*
 547 URLDataManagerBackend::CreateProtocolHandler(
 548     content::ResourceContext* resource_context,
 549     bool is_incognito,
 550     AppCacheServiceImpl* appcache_service,
 551     ChromeBlobStorageContext* blob_storage_context) {
 552   DCHECK(resource_context);
 553   return new ChromeProtocolHandler(
 554       resource_context, is_incognito, appcache_service, blob_storage_context);
 555 }
 556
 557 void URLDataManagerBackend::AddDataSource(
 558     URLDataSourceImpl* source) {
 559   DCHECK_CURRENTLY_ON(BrowserThread::IO);
 560   DataSourceMap::iterator i = data_sources_.find(source->source_name());
 561   if (i != data_sources_.end()) {
 562     if (!source->source()->ShouldReplaceExistingSource())
 563       return;
 564     i->second->backend_ = NULL;
 565   }
 566   data_sources_[source->source_name()] = source;
 567   source->backend_ = this;
 568 }
 569
 570 bool URLDataManagerBackend::HasPendingJob(
 571     URLRequestChromeJob* job) const {
 572   for (PendingRequestMap::const_iterator i = pending_requests_.begin();
 573        i != pending_requests_.end(); ++i) {
 574     if (i->second == job)
 575       return true;
 576   }
 577   return false;
 578 }
 579
 580 bool URLDataManagerBackend::StartRequest(const net::URLRequest* request,
 581                                          URLRequestChromeJob* job) {
 582   if (!CheckURLIsValid(request->url()))
 583     return false;
 584
 585   URLDataSourceImpl* source = GetDataSourceFromURL(request->url());
 586   if (!source)
 587     return false;
 588
 589   if (!source->source()->ShouldServiceRequest(request))
 590     return false;
 591
 592   std::string path;
 593   URLToRequestPath(request->url(), &path);
 594   source->source()->WillServiceRequest(request, &path);
 595
 596   // Save this request so we know where to send the data.
 597   RequestID request_id = next_request_id_++;
 598   pending_requests_.insert(std::make_pair(request_id, job));
 599
 600   job->set_allow_caching(source->source()->AllowCaching());
 601   job->set_add_content_security_policy(
 602       source->source()->ShouldAddContentSecurityPolicy());
 603   job->set_content_security_policy_object_source(
 604       source->source()->GetContentSecurityPolicyObjectSrc());
 605   job->set_content_security_policy_frame_source(
 606       source->source()->GetContentSecurityPolicyFrameSrc());
 607   job->set_deny_xframe_options(
 608       source->source()->ShouldDenyXFrameOptions());
 609   job->set_send_content_type_header(
 610       source->source()->ShouldServeMimeTypeAsContentTypeHeader());
 611
 612   std::string origin = GetOriginHeaderValue(request);
 613   if (!origin.empty()) {
 614     std::string header =
 615         source->source()->GetAccessControlAllowOriginForOrigin(origin);
 616     DCHECK(header.empty() || header == origin || header == "*" ||
 617            header == "null");
 618     job->set_access_control_allow_origin(header);
 619   }
 620
 621   // Look up additional request info to pass down.
 622   int render_process_id = -1;
 623   int render_frame_id = -1;
 624   ResourceRequestInfo::GetRenderFrameForRequest(request,
 625                                                 &render_process_id,
 626                                                 &render_frame_id);
 627
 628   // Forward along the request to the data source.
 629   base::MessageLoop* target_message_loop =
 630       source->source()->MessageLoopForRequestPath(path);
 631   if (!target_message_loop) {
 632     job->MimeTypeAvailable(source->source()->GetMimeType(path));
 633     // Eliminate potentially dangling pointer to avoid future use.
 634     job = NULL;
 635
 636     // The DataSource is agnostic to which thread StartDataRequest is called
 637     // on for this path.  Call directly into it from this thread, the IO
 638     // thread.
 639     source->source()->StartDataRequest(
 640         path, render_process_id, render_frame_id,
 641         base::Bind(&URLDataSourceImpl::SendResponse, source, request_id));
 642   } else {
 643     // URLRequestChromeJob should receive mime type before data. This
 644     // is guaranteed because request for mime type is placed in the
 645     // message loop before request for data. And correspondingly their
 646     // replies are put on the IO thread in the same order.
 647     target_message_loop->PostTask(
 648         FROM_HERE,
 649         base::Bind(&GetMimeTypeOnUI,
 650                    scoped_refptr<URLDataSourceImpl>(source),
 651                    path, job->AsWeakPtr()));
 652
 653     // The DataSource wants StartDataRequest to be called on a specific thread,
 654     // usually the UI thread, for this path.
 655     target_message_loop->PostTask(
 656         FROM_HERE,
 657         base::Bind(&URLDataManagerBackend::CallStartRequest,
 658                    make_scoped_refptr(source), path, render_process_id,
 659                    render_frame_id, request_id));
 660   }
 661   return true;
 662 }
 663
 664 URLDataSourceImpl* URLDataManagerBackend::GetDataSourceFromURL(
 665     const GURL& url) {
 666   // The input usually looks like: chrome://source_name/extra_bits?foo
 667   // so do a lookup using the host of the URL.
 668   DataSourceMap::iterator i = data_sources_.find(url.host());
 669   if (i != data_sources_.end())
 670     return i->second.get();
 671
 672   // No match using the host of the URL, so do a lookup using the scheme for
 673   // URLs on the form source_name://extra_bits/foo .
 674   i = data_sources_.find(url.scheme() + "://");
 675   if (i != data_sources_.end())
 676     return i->second.get();
 677
 678   // No matches found, so give up.
 679   return NULL;
 680 }
 681
 682 void URLDataManagerBackend::CallStartRequest(
 683     scoped_refptr<URLDataSourceImpl> source,
 684     const std::string& path,
 685     int render_process_id,
 686     int render_frame_id,
 687     int request_id) {
 688   if (BrowserThread::CurrentlyOn(BrowserThread::UI) &&
 689       render_process_id != -1 &&
 690       !RenderProcessHost::FromID(render_process_id)) {
 691     // Make the request fail if its initiating renderer is no longer valid.
 692     // This can happen when the IO thread posts this task just before the
 693     // renderer shuts down.
 694     source->SendResponse(request_id, NULL);
 695     return;
 696   }
 697   source->source()->StartDataRequest(
 698       path,
 699       render_process_id,
 700       render_frame_id,
 701       base::Bind(&URLDataSourceImpl::SendResponse, source, request_id));
 702 }
 703
 704 void URLDataManagerBackend::RemoveRequest(URLRequestChromeJob* job) {
 705   // Remove the request from our list of pending requests.
 706   // If/when the source sends the data that was requested, the data will just
 707   // be thrown away.
 708   for (PendingRequestMap::iterator i = pending_requests_.begin();
 709        i != pending_requests_.end(); ++i) {
 710     if (i->second == job) {
 711       pending_requests_.erase(i);
 712       return;
 713     }
 714   }
 715 }
 716
 717 void URLDataManagerBackend::DataAvailable(RequestID request_id,
 718                                           base::RefCountedMemory* bytes) {
 719   // Forward this data on to the pending net::URLRequest, if it exists.
 720   PendingRequestMap::iterator i = pending_requests_.find(request_id);
 721   if (i != pending_requests_.end()) {
 722     URLRequestChromeJob* job = i->second;
 723     pending_requests_.erase(i);
 724     job->DataAvailable(bytes);
 725   }
 726 }
 727
 728 namespace {
 729
 730 class DevToolsJobFactory
 731     : public net::URLRequestJobFactory::ProtocolHandler {
 732  public:
 733   // |is_incognito| should be set for incognito profiles.
 734   DevToolsJobFactory(content::ResourceContext* resource_context,
 735                      bool is_incognito);
 736   ~DevToolsJobFactory() override;
 737
 738   net::URLRequestJob* MaybeCreateJob(
 739       net::URLRequest* request,
 740       net::NetworkDelegate* network_delegate) const override;
 741
 742  private:
 743   // |resource_context_| and |network_delegate_| are owned by ProfileIOData,
 744   // which owns this ProtocolHandler.
 745   content::ResourceContext* const resource_context_;
 746
 747   // True when generated from an incognito profile.
 748   const bool is_incognito_;
 749
 750   DISALLOW_COPY_AND_ASSIGN(DevToolsJobFactory);
 751 };
 752
 753 DevToolsJobFactory::DevToolsJobFactory(
 754     content::ResourceContext* resource_context,
 755     bool is_incognito)
 756     : resource_context_(resource_context),
 757       is_incognito_(is_incognito) {
 758   DCHECK(resource_context_);
 759 }
 760
 761 DevToolsJobFactory::~DevToolsJobFactory() {}
 762
 763 net::URLRequestJob*
 764 DevToolsJobFactory::MaybeCreateJob(
 765     net::URLRequest* request, net::NetworkDelegate* network_delegate) const {
 766   return new URLRequestChromeJob(
 767       request, network_delegate,
 768       GetURLDataManagerForResourceContext(resource_context_), is_incognito_);
 769 }
 770
 771 }  // namespace
 772
 773 net::URLRequestJobFactory::ProtocolHandler*
 774 CreateDevToolsProtocolHandler(content::ResourceContext* resource_context,
 775                               bool is_incognito) {
 776   return new DevToolsJobFactory(resource_context, is_incognito);
 777 }
 778
 779 }  // namespace content