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       // TODO(pkasting): Remove ScopedTracker below once crbug.com/455423 is
 341       // fixed.
 342       tracked_objects::ScopedTracker tracking_profile(
 343           FROM_HERE_WITH_EXPLICIT_FUNCTION(
 344               "455423 URLRequestChromeJob::CompleteRead"));
 345       CompleteRead(pending_buf_.get(), pending_buf_size_, &bytes_read);
 346       pending_buf_ = NULL;
 347       NotifyReadComplete(bytes_read);
 348     }
 349   } else {
 350     // TODO(pkasting): Remove ScopedTracker below once crbug.com/455423 is
 351     // fixed.
 352     tracked_objects::ScopedTracker tracking_profile(
 353         FROM_HERE_WITH_EXPLICIT_FUNCTION("455423 URLRequestJob::NotifyDone"));
 354     // The request failed.
 355     NotifyDone(net::URLRequestStatus(net::URLRequestStatus::FAILED,
 356                                      net::ERR_FAILED));
 357   }
 358 }
 359
 360 bool URLRequestChromeJob::ReadRawData(net::IOBuffer* buf, int buf_size,
 361                                       int* bytes_read) {
 362   // TODO(vadimt): Remove ScopedTracker below once crbug.com/423948 is fixed.
 363   tracked_objects::ScopedTracker tracking_profile(
 364       FROM_HERE_WITH_EXPLICIT_FUNCTION(
 365           "423948 URLRequestChromeJob::ReadRawData"));
 366
 367   if (!data_.get()) {
 368     SetStatus(net::URLRequestStatus(net::URLRequestStatus::IO_PENDING, 0));
 369     DCHECK(!pending_buf_.get());
 370     CHECK(buf->data());
 371     pending_buf_ = buf;
 372     pending_buf_size_ = buf_size;
 373     return false;  // Tell the caller we're still waiting for data.
 374   }
 375
 376   // Otherwise, the data is available.
 377   CompleteRead(buf, buf_size, bytes_read);
 378   return true;
 379 }
 380
 381 void URLRequestChromeJob::CompleteRead(net::IOBuffer* buf, int buf_size,
 382                                        int* bytes_read) {
 383   // http://crbug.com/373841
 384   char url_buf[128];
 385   base::strlcpy(url_buf, request_->url().spec().c_str(), arraysize(url_buf));
 386   base::debug::Alias(url_buf);
 387
 388   int remaining = static_cast<int>(data_->size()) - data_offset_;
 389   if (buf_size > remaining)
 390     buf_size = remaining;
 391   if (buf_size > 0) {
 392     memcpy(buf->data(), data_->front() + data_offset_, buf_size);
 393     data_offset_ += buf_size;
 394   }
 395   *bytes_read = buf_size;
 396 }
 397
 398 void URLRequestChromeJob::CheckStoragePartitionMatches(
 399     int render_process_id,
 400     const GURL& url,
 401     const base::WeakPtr<URLRequestChromeJob>& job) {
 402   // The embedder could put some webui pages in separate storage partition.
 403   // RenderProcessHostImpl::IsSuitableHost would guard against top level pages
 404   // being in the same process. We do an extra check to guard against an
 405   // exploited renderer pretending to add them as a subframe. We skip this check
 406   // for resources.
 407   bool allowed = false;
 408   std::vector<std::string> hosts;
 409   GetContentClient()->
 410       browser()->GetAdditionalWebUIHostsToIgnoreParititionCheck(&hosts);
 411   if (url.SchemeIs(kChromeUIScheme) &&
 412       (url.SchemeIs(kChromeUIScheme) ||
 413        std::find(hosts.begin(), hosts.end(), url.host()) != hosts.end())) {
 414     allowed = true;
 415   } else if (render_process_id == kNoRenderProcessId) {
 416     // Request was not issued by renderer.
 417     allowed = true;
 418   } else {
 419     RenderProcessHost* process = RenderProcessHost::FromID(render_process_id);
 420     if (process) {
 421       StoragePartition* partition = BrowserContext::GetStoragePartitionForSite(
 422           process->GetBrowserContext(), url);
 423       allowed = partition == process->GetStoragePartition();
 424     }
 425   }
 426
 427   BrowserThread::PostTask(
 428       BrowserThread::IO,
 429       FROM_HERE,
 430       base::Bind(&URLRequestChromeJob::StartAsync, job, allowed));
 431 }
 432
 433 void URLRequestChromeJob::StartAsync(bool allowed) {
 434   if (!request_)
 435     return;
 436
 437   if (!allowed || !backend_->StartRequest(request_, this)) {
 438     NotifyStartError(net::URLRequestStatus(net::URLRequestStatus::FAILED,
 439                                            net::ERR_INVALID_URL));
 440   }
 441 }
 442
 443 namespace {
 444
 445 // Gets mime type for data that is available from |source| by |path|.
 446 // After that, notifies |job| that mime type is available. This method
 447 // should be called on the UI thread, but notification is performed on
 448 // the IO thread.
 449 void GetMimeTypeOnUI(URLDataSourceImpl* source,
 450                      const std::string& path,
 451                      const base::WeakPtr<URLRequestChromeJob>& job) {
 452   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
 453   std::string mime_type = source->source()->GetMimeType(path);
 454   BrowserThread::PostTask(
 455       BrowserThread::IO, FROM_HERE,
 456       base::Bind(&URLRequestChromeJob::MimeTypeAvailable, job, mime_type));
 457 }
 458
 459 }  // namespace
 460
 461 namespace {
 462
 463 class ChromeProtocolHandler
 464     : public net::URLRequestJobFactory::ProtocolHandler {
 465  public:
 466   // |is_incognito| should be set for incognito profiles.
 467   ChromeProtocolHandler(ResourceContext* resource_context,
 468                         bool is_incognito,
 469                         AppCacheServiceImpl* appcache_service,
 470                         ChromeBlobStorageContext* blob_storage_context)
 471       : resource_context_(resource_context),
 472         is_incognito_(is_incognito),
 473         appcache_service_(appcache_service),
 474         blob_storage_context_(blob_storage_context) {}
 475   ~ChromeProtocolHandler() override {}
 476
 477   net::URLRequestJob* MaybeCreateJob(
 478       net::URLRequest* request,
 479       net::NetworkDelegate* network_delegate) const override {
 480     DCHECK(request);
 481
 482     // Check for chrome://view-http-cache/*, which uses its own job type.
 483     if (ViewHttpCacheJobFactory::IsSupportedURL(request->url()))
 484       return ViewHttpCacheJobFactory::CreateJobForRequest(request,
 485                                                           network_delegate);
 486
 487     // Next check for chrome://appcache-internals/, which uses its own job type.
 488     if (request->url().SchemeIs(kChromeUIScheme) &&
 489         request->url().host() == kChromeUIAppCacheInternalsHost) {
 490       return ViewAppCacheInternalsJobFactory::CreateJobForRequest(
 491           request, network_delegate, appcache_service_);
 492     }
 493
 494     // Next check for chrome://blob-internals/, which uses its own job type.
 495     if (ViewBlobInternalsJobFactory::IsSupportedURL(request->url())) {
 496       return ViewBlobInternalsJobFactory::CreateJobForRequest(
 497           request, network_delegate, blob_storage_context_->context());
 498     }
 499
 500 #if defined(USE_TCMALLOC)
 501     // Next check for chrome://tcmalloc/, which uses its own job type.
 502     if (request->url().SchemeIs(kChromeUIScheme) &&
 503         request->url().host() == kChromeUITcmallocHost) {
 504       return new TcmallocInternalsRequestJob(request, network_delegate);
 505     }
 506 #endif
 507
 508     // Next check for chrome://histograms/, which uses its own job type.
 509     if (request->url().SchemeIs(kChromeUIScheme) &&
 510         request->url().host() == kChromeUIHistogramHost) {
 511       return new HistogramInternalsRequestJob(request, network_delegate);
 512     }
 513
 514     // Fall back to using a custom handler
 515     return new URLRequestChromeJob(
 516         request, network_delegate,
 517         GetURLDataManagerForResourceContext(resource_context_), is_incognito_);
 518   }
 519
 520   bool IsSafeRedirectTarget(const GURL& location) const override {
 521     return false;
 522   }
 523
 524  private:
 525   // These members are owned by ProfileIOData, which owns this ProtocolHandler.
 526   content::ResourceContext* const resource_context_;
 527
 528   // True when generated from an incognito profile.
 529   const bool is_incognito_;
 530   AppCacheServiceImpl* appcache_service_;
 531   ChromeBlobStorageContext* blob_storage_context_;
 532
 533   DISALLOW_COPY_AND_ASSIGN(ChromeProtocolHandler);
 534 };
 535
 536 }  // namespace
 537
 538 URLDataManagerBackend::URLDataManagerBackend()
 539     : next_request_id_(0) {
 540   URLDataSource* shared_source = new SharedResourcesDataSource();
 541   URLDataSourceImpl* source_impl =
 542       new URLDataSourceImpl(shared_source->GetSource(), shared_source);
 543   AddDataSource(source_impl);
 544 }
 545
 546 URLDataManagerBackend::~URLDataManagerBackend() {
 547   for (DataSourceMap::iterator i = data_sources_.begin();
 548        i != data_sources_.end(); ++i) {
 549     i->second->backend_ = NULL;
 550   }
 551   data_sources_.clear();
 552 }
 553
 554 // static
 555 net::URLRequestJobFactory::ProtocolHandler*
 556 URLDataManagerBackend::CreateProtocolHandler(
 557     content::ResourceContext* resource_context,
 558     bool is_incognito,
 559     AppCacheServiceImpl* appcache_service,
 560     ChromeBlobStorageContext* blob_storage_context) {
 561   DCHECK(resource_context);
 562   return new ChromeProtocolHandler(
 563       resource_context, is_incognito, appcache_service, blob_storage_context);
 564 }
 565
 566 void URLDataManagerBackend::AddDataSource(
 567     URLDataSourceImpl* source) {
 568   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::IO));
 569   DataSourceMap::iterator i = data_sources_.find(source->source_name());
 570   if (i != data_sources_.end()) {
 571     if (!source->source()->ShouldReplaceExistingSource())
 572       return;
 573     i->second->backend_ = NULL;
 574   }
 575   data_sources_[source->source_name()] = source;
 576   source->backend_ = this;
 577 }
 578
 579 bool URLDataManagerBackend::HasPendingJob(
 580     URLRequestChromeJob* job) const {
 581   for (PendingRequestMap::const_iterator i = pending_requests_.begin();
 582        i != pending_requests_.end(); ++i) {
 583     if (i->second == job)
 584       return true;
 585   }
 586   return false;
 587 }
 588
 589 bool URLDataManagerBackend::StartRequest(const net::URLRequest* request,
 590                                          URLRequestChromeJob* job) {
 591   if (!CheckURLIsValid(request->url()))
 592     return false;
 593
 594   URLDataSourceImpl* source = GetDataSourceFromURL(request->url());
 595   if (!source)
 596     return false;
 597
 598   if (!source->source()->ShouldServiceRequest(request))
 599     return false;
 600
 601   std::string path;
 602   URLToRequestPath(request->url(), &path);
 603   source->source()->WillServiceRequest(request, &path);
 604
 605   // Save this request so we know where to send the data.
 606   RequestID request_id = next_request_id_++;
 607   pending_requests_.insert(std::make_pair(request_id, job));
 608
 609   job->set_allow_caching(source->source()->AllowCaching());
 610   job->set_add_content_security_policy(
 611       source->source()->ShouldAddContentSecurityPolicy());
 612   job->set_content_security_policy_object_source(
 613       source->source()->GetContentSecurityPolicyObjectSrc());
 614   job->set_content_security_policy_frame_source(
 615       source->source()->GetContentSecurityPolicyFrameSrc());
 616   job->set_deny_xframe_options(
 617       source->source()->ShouldDenyXFrameOptions());
 618   job->set_send_content_type_header(
 619       source->source()->ShouldServeMimeTypeAsContentTypeHeader());
 620
 621   std::string origin = GetOriginHeaderValue(request);
 622   if (!origin.empty()) {
 623     std::string header =
 624         source->source()->GetAccessControlAllowOriginForOrigin(origin);
 625     DCHECK(header.empty() || header == origin || header == "*" ||
 626            header == "null");
 627     job->set_access_control_allow_origin(header);
 628   }
 629
 630   // Look up additional request info to pass down.
 631   int render_process_id = -1;
 632   int render_frame_id = -1;
 633   ResourceRequestInfo::GetRenderFrameForRequest(request,
 634                                                 &render_process_id,
 635                                                 &render_frame_id);
 636
 637   // Forward along the request to the data source.
 638   base::MessageLoop* target_message_loop =
 639       source->source()->MessageLoopForRequestPath(path);
 640   if (!target_message_loop) {
 641     job->MimeTypeAvailable(source->source()->GetMimeType(path));
 642     // Eliminate potentially dangling pointer to avoid future use.
 643     job = NULL;
 644
 645     // The DataSource is agnostic to which thread StartDataRequest is called
 646     // on for this path.  Call directly into it from this thread, the IO
 647     // thread.
 648     source->source()->StartDataRequest(
 649         path, render_process_id, render_frame_id,
 650         base::Bind(&URLDataSourceImpl::SendResponse, source, request_id));
 651   } else {
 652     // URLRequestChromeJob should receive mime type before data. This
 653     // is guaranteed because request for mime type is placed in the
 654     // message loop before request for data. And correspondingly their
 655     // replies are put on the IO thread in the same order.
 656     target_message_loop->PostTask(
 657         FROM_HERE,
 658         base::Bind(&GetMimeTypeOnUI,
 659                    scoped_refptr<URLDataSourceImpl>(source),
 660                    path, job->AsWeakPtr()));
 661
 662     // The DataSource wants StartDataRequest to be called on a specific thread,
 663     // usually the UI thread, for this path.
 664     target_message_loop->PostTask(
 665         FROM_HERE,
 666         base::Bind(&URLDataManagerBackend::CallStartRequest,
 667                    make_scoped_refptr(source), path, render_process_id,
 668                    render_frame_id, request_id));
 669   }
 670   return true;
 671 }
 672
 673 URLDataSourceImpl* URLDataManagerBackend::GetDataSourceFromURL(
 674     const GURL& url) {
 675   // The input usually looks like: chrome://source_name/extra_bits?foo
 676   // so do a lookup using the host of the URL.
 677   DataSourceMap::iterator i = data_sources_.find(url.host());
 678   if (i != data_sources_.end())
 679     return i->second.get();
 680
 681   // No match using the host of the URL, so do a lookup using the scheme for
 682   // URLs on the form source_name://extra_bits/foo .
 683   i = data_sources_.find(url.scheme() + "://");
 684   if (i != data_sources_.end())
 685     return i->second.get();
 686
 687   // No matches found, so give up.
 688   return NULL;
 689 }
 690
 691 void URLDataManagerBackend::CallStartRequest(
 692     scoped_refptr<URLDataSourceImpl> source,
 693     const std::string& path,
 694     int render_process_id,
 695     int render_frame_id,
 696     int request_id) {
 697   if (BrowserThread::CurrentlyOn(BrowserThread::UI) &&
 698       render_process_id != -1 &&
 699       !RenderProcessHost::FromID(render_process_id)) {
 700     // Make the request fail if its initiating renderer is no longer valid.
 701     // This can happen when the IO thread posts this task just before the
 702     // renderer shuts down.
 703     source->SendResponse(request_id, NULL);
 704     return;
 705   }
 706   source->source()->StartDataRequest(
 707       path,
 708       render_process_id,
 709       render_frame_id,
 710       base::Bind(&URLDataSourceImpl::SendResponse, source, request_id));
 711 }
 712
 713 void URLDataManagerBackend::RemoveRequest(URLRequestChromeJob* job) {
 714   // Remove the request from our list of pending requests.
 715   // If/when the source sends the data that was requested, the data will just
 716   // be thrown away.
 717   for (PendingRequestMap::iterator i = pending_requests_.begin();
 718        i != pending_requests_.end(); ++i) {
 719     if (i->second == job) {
 720       pending_requests_.erase(i);
 721       return;
 722     }
 723   }
 724 }
 725
 726 void URLDataManagerBackend::DataAvailable(RequestID request_id,
 727                                           base::RefCountedMemory* bytes) {
 728   // TODO(pkasting): Remove ScopedTracker below once crbug.com/455423 is fixed.
 729   tracked_objects::ScopedTracker tracking_profile(
 730       FROM_HERE_WITH_EXPLICIT_FUNCTION(
 731           "455423 URLDataManagerBackend::DataAvailable"));
 732   // Forward this data on to the pending net::URLRequest, if it exists.
 733   PendingRequestMap::iterator i = pending_requests_.find(request_id);
 734   if (i != pending_requests_.end()) {
 735     URLRequestChromeJob* job = i->second;
 736     pending_requests_.erase(i);
 737     job->DataAvailable(bytes);
 738   }
 739 }
 740
 741 namespace {
 742
 743 class DevToolsJobFactory
 744     : public net::URLRequestJobFactory::ProtocolHandler {
 745  public:
 746   // |is_incognito| should be set for incognito profiles.
 747   DevToolsJobFactory(content::ResourceContext* resource_context,
 748                      bool is_incognito);
 749   ~DevToolsJobFactory() override;
 750
 751   net::URLRequestJob* MaybeCreateJob(
 752       net::URLRequest* request,
 753       net::NetworkDelegate* network_delegate) const override;
 754
 755  private:
 756   // |resource_context_| and |network_delegate_| are owned by ProfileIOData,
 757   // which owns this ProtocolHandler.
 758   content::ResourceContext* const resource_context_;
 759
 760   // True when generated from an incognito profile.
 761   const bool is_incognito_;
 762
 763   DISALLOW_COPY_AND_ASSIGN(DevToolsJobFactory);
 764 };
 765
 766 DevToolsJobFactory::DevToolsJobFactory(
 767     content::ResourceContext* resource_context,
 768     bool is_incognito)
 769     : resource_context_(resource_context),
 770       is_incognito_(is_incognito) {
 771   DCHECK(resource_context_);
 772 }
 773
 774 DevToolsJobFactory::~DevToolsJobFactory() {}
 775
 776 net::URLRequestJob*
 777 DevToolsJobFactory::MaybeCreateJob(
 778     net::URLRequest* request, net::NetworkDelegate* network_delegate) const {
 779   return new URLRequestChromeJob(
 780       request, network_delegate,
 781       GetURLDataManagerForResourceContext(resource_context_), is_incognito_);
 782 }
 783
 784 }  // namespace
 785
 786 net::URLRequestJobFactory::ProtocolHandler*
 787 CreateDevToolsProtocolHandler(content::ResourceContext* resource_context,
 788                               bool is_incognito) {
 789   return new DevToolsJobFactory(resource_context, is_incognito);
 790 }
 791
 792 }  // namespace content