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.
5 #include "content/browser/loader/buffered_resource_handler.h"
10 #include "base/logging.h"
11 #include "base/metrics/histogram.h"
12 #include "base/strings/string_util.h"
13 #include "content/browser/download/download_resource_handler.h"
14 #include "content/browser/download/download_stats.h"
15 #include "content/browser/loader/certificate_resource_handler.h"
16 #include "content/browser/loader/resource_dispatcher_host_impl.h"
17 #include "content/browser/loader/resource_request_info_impl.h"
18 #include "content/browser/plugin_service_impl.h"
19 #include "content/public/browser/content_browser_client.h"
20 #include "content/public/browser/download_item.h"
21 #include "content/public/browser/download_save_info.h"
22 #include "content/public/browser/download_url_parameters.h"
23 #include "content/public/browser/resource_context.h"
24 #include "content/public/browser/resource_dispatcher_host_delegate.h"
25 #include "content/public/common/resource_response.h"
26 #include "content/public/common/webplugininfo.h"
27 #include "net/base/io_buffer.h"
28 #include "net/base/mime_sniffer.h"
29 #include "net/base/mime_util.h"
30 #include "net/base/net_errors.h"
31 #include "net/http/http_content_disposition.h"
32 #include "net/http/http_response_headers.h"
38 void RecordSnifferMetrics(bool sniffing_blocked,
39 bool we_would_like_to_sniff,
40 const std::string& mime_type) {
41 static base::HistogramBase* nosniff_usage(NULL);
43 nosniff_usage = base::BooleanHistogram::FactoryGet(
44 "nosniff.usage", base::HistogramBase::kUmaTargetedHistogramFlag);
45 nosniff_usage->AddBoolean(sniffing_blocked);
47 if (sniffing_blocked) {
48 static base::HistogramBase* nosniff_otherwise(NULL);
49 if (!nosniff_otherwise)
50 nosniff_otherwise = base::BooleanHistogram::FactoryGet(
51 "nosniff.otherwise", base::HistogramBase::kUmaTargetedHistogramFlag);
52 nosniff_otherwise->AddBoolean(we_would_like_to_sniff);
54 static base::HistogramBase* nosniff_empty_mime_type(NULL);
55 if (!nosniff_empty_mime_type)
56 nosniff_empty_mime_type = base::BooleanHistogram::FactoryGet(
57 "nosniff.empty_mime_type",
58 base::HistogramBase::kUmaTargetedHistogramFlag);
59 nosniff_empty_mime_type->AddBoolean(mime_type.empty());
63 // Used to write into an existing IOBuffer at a given offset.
64 class DependentIOBuffer : public net::WrappedIOBuffer {
66 DependentIOBuffer(net::IOBuffer* buf, int offset)
67 : net::WrappedIOBuffer(buf->data() + offset),
72 virtual ~DependentIOBuffer() {}
74 scoped_refptr<net::IOBuffer> buf_;
79 BufferedResourceHandler::BufferedResourceHandler(
80 scoped_ptr<ResourceHandler> next_handler,
81 ResourceDispatcherHostImpl* host,
82 net::URLRequest* request)
83 : LayeredResourceHandler(request, next_handler.Pass()),
84 state_(STATE_STARTING),
88 must_download_(false),
89 must_download_is_set_(false),
90 weak_ptr_factory_(this) {
93 BufferedResourceHandler::~BufferedResourceHandler() {
96 void BufferedResourceHandler::SetController(ResourceController* controller) {
97 ResourceHandler::SetController(controller);
99 // Downstream handlers see us as their ResourceController, which allows us to
100 // consume part or all of the resource response, and then later replay it to
101 // downstream handler.
102 DCHECK(next_handler_.get());
103 next_handler_->SetController(this);
106 bool BufferedResourceHandler::OnResponseStarted(
108 ResourceResponse* response,
110 response_ = response;
112 // TODO(darin): It is very odd to special-case 304 responses at this level.
113 // We do so only because the code always has, see r24977 and r29355. The
114 // fact that 204 is no longer special-cased this way suggests that 304 need
115 // not be special-cased either.
117 // The network stack only forwards 304 responses that were not received in
118 // response to a conditional request (i.e., If-Modified-Since). Other 304
119 // responses end up being translated to 200 or whatever the cached response
120 // code happens to be. It should be very rare to see a 304 at this level.
122 if (!(response_->head.headers.get() &&
123 response_->head.headers->response_code() == 304)) {
124 if (ShouldSniffContent()) {
125 state_ = STATE_BUFFERING;
129 if (response_->head.mime_type.empty()) {
130 // Ugg. The server told us not to sniff the content but didn't give us
131 // a mime type. What's a browser to do? Turns out, we're supposed to
132 // treat the response as "text/plain". This is the most secure option.
133 response_->head.mime_type.assign("text/plain");
136 // Treat feed types as text/plain.
137 if (response_->head.mime_type == "application/rss+xml" ||
138 response_->head.mime_type == "application/atom+xml") {
139 response_->head.mime_type.assign("text/plain");
143 state_ = STATE_PROCESSING;
144 return ProcessResponse(defer);
147 // We'll let the original event handler provide a buffer, and reuse it for
148 // subsequent reads until we're done buffering.
149 bool BufferedResourceHandler::OnWillRead(int request_id,
150 scoped_refptr<net::IOBuffer>* buf,
153 if (state_ == STATE_STREAMING)
154 return next_handler_->OnWillRead(request_id, buf, buf_size, min_size);
156 DCHECK_EQ(-1, min_size);
158 if (read_buffer_.get()) {
159 CHECK_LT(bytes_read_, read_buffer_size_);
160 *buf = new DependentIOBuffer(read_buffer_.get(), bytes_read_);
161 *buf_size = read_buffer_size_ - bytes_read_;
163 if (!next_handler_->OnWillRead(request_id, buf, buf_size, min_size))
167 read_buffer_size_ = *buf_size;
168 DCHECK_GE(read_buffer_size_, net::kMaxBytesToSniff * 2);
173 bool BufferedResourceHandler::OnReadCompleted(int request_id, int bytes_read,
175 if (state_ == STATE_STREAMING)
176 return next_handler_->OnReadCompleted(request_id, bytes_read, defer);
178 DCHECK_EQ(state_, STATE_BUFFERING);
179 bytes_read_ += bytes_read;
181 if (!DetermineMimeType() && (bytes_read > 0))
182 return true; // Needs more data, so keep buffering.
184 state_ = STATE_PROCESSING;
185 return ProcessResponse(defer);
188 bool BufferedResourceHandler::OnResponseCompleted(
190 const net::URLRequestStatus& status,
191 const std::string& security_info) {
192 // Upon completion, act like a pass-through handler in case the downstream
193 // handler defers OnResponseCompleted.
194 state_ = STATE_STREAMING;
196 return next_handler_->OnResponseCompleted(request_id, status, security_info);
199 void BufferedResourceHandler::Resume() {
201 case STATE_BUFFERING:
202 case STATE_PROCESSING:
205 case STATE_REPLAYING:
206 base::MessageLoop::current()->PostTask(
208 base::Bind(&BufferedResourceHandler::CallReplayReadCompleted,
209 weak_ptr_factory_.GetWeakPtr()));
212 case STATE_STREAMING:
213 controller()->Resume();
218 void BufferedResourceHandler::Cancel() {
219 controller()->Cancel();
222 void BufferedResourceHandler::CancelAndIgnore() {
223 controller()->CancelAndIgnore();
226 void BufferedResourceHandler::CancelWithError(int error_code) {
227 controller()->CancelWithError(error_code);
230 bool BufferedResourceHandler::ProcessResponse(bool* defer) {
231 DCHECK_EQ(STATE_PROCESSING, state_);
233 // TODO(darin): Stop special-casing 304 responses.
234 if (!(response_->head.headers.get() &&
235 response_->head.headers->response_code() == 304)) {
236 if (!SelectNextHandler(defer))
242 state_ = STATE_REPLAYING;
244 if (!next_handler_->OnResponseStarted(GetRequestID(), response_.get(), defer))
247 if (!read_buffer_.get()) {
248 state_ = STATE_STREAMING;
253 return ReplayReadCompleted(defer);
258 bool BufferedResourceHandler::ShouldSniffContent() {
259 const std::string& mime_type = response_->head.mime_type;
261 std::string content_type_options;
262 request()->GetResponseHeaderByName("x-content-type-options",
263 &content_type_options);
265 bool sniffing_blocked =
266 LowerCaseEqualsASCII(content_type_options, "nosniff");
267 bool we_would_like_to_sniff =
268 net::ShouldSniffMimeType(request()->url(), mime_type);
270 RecordSnifferMetrics(sniffing_blocked, we_would_like_to_sniff, mime_type);
272 if (!sniffing_blocked && we_would_like_to_sniff) {
273 // We're going to look at the data before deciding what the content type
274 // is. That means we need to delay sending the ResponseStarted message
275 // over the IPC channel.
276 VLOG(1) << "To buffer: " << request()->url().spec();
283 bool BufferedResourceHandler::DetermineMimeType() {
284 DCHECK_EQ(STATE_BUFFERING, state_);
286 const std::string& type_hint = response_->head.mime_type;
288 std::string new_type;
289 bool made_final_decision =
290 net::SniffMimeType(read_buffer_->data(), bytes_read_, request()->url(),
291 type_hint, &new_type);
293 // SniffMimeType() returns false if there is not enough data to determine
294 // the mime type. However, even if it returns false, it returns a new type
295 // that is probably better than the current one.
296 response_->head.mime_type.assign(new_type);
298 return made_final_decision;
301 bool BufferedResourceHandler::SelectNextHandler(bool* defer) {
302 DCHECK(!response_->head.mime_type.empty());
304 ResourceRequestInfoImpl* info = GetRequestInfo();
305 const std::string& mime_type = response_->head.mime_type;
307 if (net::IsSupportedCertificateMimeType(mime_type)) {
308 // Install certificate file.
309 scoped_ptr<ResourceHandler> handler(
310 new CertificateResourceHandler(request()));
311 return UseAlternateNextHandler(handler.Pass());
314 if (!info->allow_download())
317 bool must_download = MustDownload();
318 if (!must_download) {
319 if (net::IsSupportedMimeType(mime_type))
322 scoped_ptr<ResourceHandler> handler(
323 host_->MaybeInterceptAsStream(request(), response_.get()));
325 return UseAlternateNextHandler(handler.Pass());
327 #if defined(ENABLE_PLUGINS)
329 bool has_plugin = HasSupportingPlugin(&stale);
331 // Refresh the plugins asynchronously.
332 PluginServiceImpl::GetInstance()->GetPlugins(
333 base::Bind(&BufferedResourceHandler::OnPluginsLoaded,
334 weak_ptr_factory_.GetWeakPtr()));
343 // Install download handler
344 info->set_is_download(true);
345 scoped_ptr<ResourceHandler> handler(
346 host_->CreateResourceHandlerForDownload(
348 true, // is_content_initiated
350 content::DownloadItem::kInvalidId,
351 scoped_ptr<DownloadSaveInfo>(new DownloadSaveInfo()),
352 DownloadUrlParameters::OnStartedCallback()));
353 return UseAlternateNextHandler(handler.Pass());
356 bool BufferedResourceHandler::UseAlternateNextHandler(
357 scoped_ptr<ResourceHandler> new_handler) {
358 if (response_->head.headers.get() && // Can be NULL if FTP.
359 response_->head.headers->response_code() / 100 != 2) {
360 // The response code indicates that this is an error page, but we don't
361 // know how to display the content. We follow Firefox here and show our
362 // own error page instead of triggering a download.
363 // TODO(abarth): We should abstract the response_code test, but this kind
364 // of check is scattered throughout our codebase.
365 request()->CancelWithError(net::ERR_FILE_NOT_FOUND);
369 int request_id = GetRequestID();
371 // Inform the original ResourceHandler that this will be handled entirely by
372 // the new ResourceHandler.
373 // TODO(darin): We should probably check the return values of these.
374 bool defer_ignored = false;
375 next_handler_->OnResponseStarted(request_id, response_.get(), &defer_ignored);
376 DCHECK(!defer_ignored);
377 net::URLRequestStatus status(net::URLRequestStatus::CANCELED,
379 next_handler_->OnResponseCompleted(request_id, status, std::string());
381 // This is handled entirely within the new ResourceHandler, so just reset the
382 // original ResourceHandler.
383 next_handler_ = new_handler.Pass();
384 next_handler_->SetController(this);
386 return CopyReadBufferToNextHandler(request_id);
389 bool BufferedResourceHandler::ReplayReadCompleted(bool* defer) {
390 DCHECK(read_buffer_.get());
392 bool result = next_handler_->OnReadCompleted(GetRequestID(), bytes_read_,
396 read_buffer_size_ = 0;
399 state_ = STATE_STREAMING;
404 void BufferedResourceHandler::CallReplayReadCompleted() {
406 if (!ReplayReadCompleted(&defer)) {
407 controller()->Cancel();
409 state_ = STATE_STREAMING;
410 controller()->Resume();
414 bool BufferedResourceHandler::MustDownload() {
415 if (must_download_is_set_)
416 return must_download_;
418 must_download_is_set_ = true;
420 std::string disposition;
421 request()->GetResponseHeaderByName("content-disposition", &disposition);
422 if (!disposition.empty() &&
423 net::HttpContentDisposition(disposition, std::string()).is_attachment()) {
424 must_download_ = true;
425 } else if (host_->delegate() &&
426 host_->delegate()->ShouldForceDownloadResource(
427 request()->url(), response_->head.mime_type)) {
428 must_download_ = true;
430 must_download_ = false;
433 return must_download_;
436 bool BufferedResourceHandler::HasSupportingPlugin(bool* stale) {
437 ResourceRequestInfoImpl* info = GetRequestInfo();
439 bool allow_wildcard = false;
440 WebPluginInfo plugin;
441 return PluginServiceImpl::GetInstance()->GetPluginInfo(
442 info->GetChildID(), info->GetRouteID(), info->GetContext(),
443 request()->url(), GURL(), response_->head.mime_type, allow_wildcard,
444 stale, &plugin, NULL);
447 bool BufferedResourceHandler::CopyReadBufferToNextHandler(int request_id) {
451 scoped_refptr<net::IOBuffer> buf;
453 if (!next_handler_->OnWillRead(request_id, &buf, &buf_len, bytes_read_))
456 CHECK((buf_len >= bytes_read_) && (bytes_read_ >= 0));
457 memcpy(buf->data(), read_buffer_->data(), bytes_read_);
461 void BufferedResourceHandler::OnPluginsLoaded(
462 const std::vector<WebPluginInfo>& plugins) {
464 if (!ProcessResponse(&defer)) {
465 controller()->Cancel();
467 controller()->Resume();
471 } // namespace content