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// Copyright 2015 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.
//
// Overview
//
// The main entry point is CertNetFetcherImpl. This is an implementation of
// CertNetFetcher that provides a service for fetching network requests.
//
// The interface for CertNetFetcher is synchronous, however allows
// overlapping requests. When starting a request CertNetFetcherImpl
// returns a CertNetFetcher::Request (CertNetFetcherImpl) that the
// caller can use to cancel the fetch, or wait for it to complete
// (blocking).
//
// The CertNetFetcherImpl is shared between a network thread and a
// caller thread that waits for fetches to happen on the network thread.
//
// The classes are mainly organized based on their thread affinity:
//
// ---------------
// Straddles caller thread and network thread
// ---------------
//
// CertNetFetcherImpl (implements CertNetFetcher)
// * Main entry point. Must be created and shutdown from the network thread.
// * Provides a service to start/cancel/wait for URL fetches, to be
// used on the caller thread.
// * Returns callers a CertNetFetcher::Request as a handle
// * Requests can run in parallel, however will block the current thread when
// reading results.
// * Posts tasks to network thread to coordinate actual work
//
// RequestCore
// * Reference-counted bridge between CertNetFetcherRequestImpl and the
// dependencies on the network thread
// * Holds the result of the request, a WaitableEvent for signaling
// completion, and pointers for canceling work on network thread.
//
// ---------------
// Lives on caller thread
// ---------------
//
// CertNetFetcherRequestImpl (implements CertNetFetcher::Request)
// * Wrapper for cancelling events, or waiting for a request to complete
// * Waits on a WaitableEvent to complete requests.
//
// ---------------
// Lives on network thread
// ---------------
//
// AsyncCertNetFetcherImpl
// * Asyncronous manager for outstanding requests. Handles de-duplication,
// timeouts, and actual integration with network stack. This is where the
// majority of the logic lives.
// * Signals completion of requests through RequestCore's WaitableEvent.
// * Attaches requests to Jobs for the purpose of de-duplication
#include "net/cert_net/cert_net_fetcher_impl.h"
#include <tuple>
#include <utility>
#include "base/callback_helpers.h"
#include "base/logging.h"
#include "base/macros.h"
#include "base/memory/ptr_util.h"
#include "base/numerics/safe_math.h"
#include "base/single_thread_task_runner.h"
#include "base/synchronization/waitable_event.h"
#include "base/threading/thread_task_runner_handle.h"
#include "base/timer/timer.h"
#include "net/base/load_flags.h"
#include "net/cert/cert_net_fetcher.h"
#include "net/traffic_annotation/network_traffic_annotation.h"
#include "net/url_request/redirect_info.h"
#include "net/url_request/url_request_context.h"
// TODO(eroman): Add support for POST parameters.
// TODO(eroman): Add controls for bypassing the cache.
// TODO(eroman): Add a maximum number of in-flight jobs/requests.
// TODO(eroman): Add NetLog integration.
namespace net {
namespace {
// The size of the buffer used for reading the response body of the URLRequest.
const int kReadBufferSizeInBytes = 4096;
// The maximum size in bytes for the response body when fetching a CRL.
const int kMaxResponseSizeInBytesForCrl = 5 * 1024 * 1024;
// The maximum size in bytes for the response body when fetching an AIA URL
// (caIssuers/OCSP).
const int kMaxResponseSizeInBytesForAia = 64 * 1024;
// The default timeout in seconds for fetch requests.
const int kTimeoutSeconds = 15;
class RequestCore;
struct RequestParams;
class Job;
struct JobToRequestParamsComparator;
struct JobComparator {
bool operator()(const Job* job1, const Job* job2) const;
};
// Would be a set<unique_ptr> but extraction of owned objects from a set of
// owned types doesn't come until C++17.
using JobSet = std::map<Job*, std::unique_ptr<Job>, JobComparator>;
// AsyncCertNetFetcherImpl manages URLRequests in an async fashion on the
// URLRequestContexts's task runner thread.
//
// * Schedules
// * De-duplicates requests
// * Handles timeouts
class AsyncCertNetFetcherImpl {
public:
// Initializes AsyncCertNetFetcherImpl using the specified URLRequestContext
// for issuing requests. |context| must remain valid until Shutdown() is
// called or the AsyncCertNetFetcherImpl is destroyed.
explicit AsyncCertNetFetcherImpl(URLRequestContext* context);
// The AsyncCertNetFetcherImpl is expected to be kept alive until all
// requests have completed or Shutdown() is called.
~AsyncCertNetFetcherImpl();
// Starts an asynchronous request to fetch the given URL. On completion
// request->OnJobCompleted() will be invoked.
void Fetch(std::unique_ptr<RequestParams> request_params,
scoped_refptr<RequestCore> request);
// Cancels outstanding jobs, which stops network requests and signals the
// corresponding RequestCores that the requests have completed.
void Shutdown();
private:
friend class Job;
// Finds a job with a matching RequestPararms or returns nullptr if there was
// no match.
Job* FindJob(const RequestParams& params);
// Removes |job| from the in progress jobs and transfers ownership to the
// caller.
std::unique_ptr<Job> RemoveJob(Job* job);
// The in-progress jobs. This set does not contain the job which is actively
// invoking callbacks (OnJobCompleted).
JobSet jobs_;
// Not owned. |context_| must outlive the AsyncCertNetFetcherImpl.
URLRequestContext* context_ = nullptr;
base::ThreadChecker thread_checker_;
DISALLOW_COPY_AND_ASSIGN(AsyncCertNetFetcherImpl);
};
// Policy for which URLs are allowed to be fetched. This is called both for the
// initial URL and for each redirect. Returns OK on success or a net error
// code on failure.
Error CanFetchUrl(const GURL& url) {
if (!url.SchemeIs("http"))
return ERR_DISALLOWED_URL_SCHEME;
return OK;
}
base::TimeDelta GetTimeout(int timeout_milliseconds) {
if (timeout_milliseconds == CertNetFetcher::DEFAULT)
return base::TimeDelta::FromSeconds(kTimeoutSeconds);
return base::TimeDelta::FromMilliseconds(timeout_milliseconds);
}
size_t GetMaxResponseBytes(int max_response_bytes,
size_t default_max_response_bytes) {
if (max_response_bytes == CertNetFetcher::DEFAULT)
return default_max_response_bytes;
// Ensure that the specified limit is not negative, and cannot result in an
// overflow while reading.
base::CheckedNumeric<size_t> check(max_response_bytes);
check += kReadBufferSizeInBytes;
DCHECK(check.IsValid());
return max_response_bytes;
}
enum HttpMethod {
HTTP_METHOD_GET,
HTTP_METHOD_POST,
};
// RequestCore tracks an outstanding call to Fetch(). It is
// reference-counted for ease of sharing between threads.
class RequestCore : public base::RefCountedThreadSafe<RequestCore> {
public:
explicit RequestCore(scoped_refptr<base::SingleThreadTaskRunner> task_runner)
: completion_event_(base::WaitableEvent::ResetPolicy::MANUAL,
base::WaitableEvent::InitialState::NOT_SIGNALED),
task_runner_(std::move(task_runner)) {}
void AttachedToJob(Job* job) {
DCHECK(task_runner_->RunsTasksInCurrentSequence());
DCHECK(!job_);
// Requests should not be attached to jobs after they have been signalled
// with a cancellation error (which happens via either Cancel() or
// SignalImmediateError()).
DCHECK_NE(error_, ERR_ABORTED);
job_ = job;
}
void OnJobCompleted(Job* job,
Error error,
const std::vector<uint8_t>& response_body) {
DCHECK(task_runner_->RunsTasksInCurrentSequence());
DCHECK_EQ(job_, job);
job_ = nullptr;
error_ = error;
bytes_ = response_body;
completion_event_.Signal();
}
// Detaches this request from its job (if it is attached to any) and
// signals completion with ERR_ABORTED. Can be called from any thread.
void CancelJob();
// Can be used to signal that an error was encountered before the request was
// attached to a job. Can be called from any thread.
void SignalImmediateError();
// Should only be called once.
void WaitForResult(Error* error, std::vector<uint8_t>* bytes) {
DCHECK(!task_runner_->RunsTasksInCurrentSequence());
completion_event_.Wait();
*bytes = std::move(bytes_);
*error = error_;
error_ = ERR_UNEXPECTED;
}
private:
friend class base::RefCountedThreadSafe<RequestCore>;
~RequestCore() {
// Requests should have been cancelled prior to destruction.
DCHECK(!job_);
}
// A non-owned pointer to the job that is executing the request.
Job* job_ = nullptr;
// May be written to from network thread, or from the caller thread only when
// there is no work that will be done on the network thread (e.g. when the
// network thread has been shutdown before the request begins). See comment in
// SignalImmediateError.
Error error_ = OK;
std::vector<uint8_t> bytes_;
// Indicates when |error_| and |bytes_| have been written to.
base::WaitableEvent completion_event_;
scoped_refptr<base::SingleThreadTaskRunner> task_runner_;
DISALLOW_COPY_AND_ASSIGN(RequestCore);
};
struct RequestParams {
RequestParams();
bool operator<(const RequestParams& other) const;
GURL url;
HttpMethod http_method;
size_t max_response_bytes;
// If set to a value <= 0 then means "no timeout".
base::TimeDelta timeout;
// IMPORTANT: When adding fields to this structure, update operator<().
private:
DISALLOW_COPY_AND_ASSIGN(RequestParams);
};
RequestParams::RequestParams()
: http_method(HTTP_METHOD_GET), max_response_bytes(0) {}
bool RequestParams::operator<(const RequestParams& other) const {
return std::tie(url, http_method, max_response_bytes, timeout) <
std::tie(other.url, other.http_method, other.max_response_bytes,
other.timeout);
}
// Job tracks an outstanding URLRequest as well as all of the pending requests
// for it.
class Job : public URLRequest::Delegate {
public:
Job(std::unique_ptr<RequestParams> request_params,
AsyncCertNetFetcherImpl* parent);
~Job() override;
const RequestParams& request_params() const { return *request_params_; }
// Creates a request and attaches it to the job. When the job completes it
// will notify the request of completion through OnJobCompleted.
void AttachRequest(scoped_refptr<RequestCore> request);
// Removes |request| from the job.
void DetachRequest(RequestCore* request);
// Creates and starts a URLRequest for the job. After the URLRequest has
// completed, OnJobCompleted() will be invoked and all the registered requests
// notified of completion.
void StartURLRequest(URLRequestContext* context);
// Cancels the request with an ERR_ABORTED error and invokes
// RequestCore::OnJobCompleted() to notify the registered requests of the
// cancellation. The job is *not* removed from the AsyncCertNetFetcherImpl.
void Cancel();
private:
// Implementation of URLRequest::Delegate
void OnReceivedRedirect(URLRequest* request,
const RedirectInfo& redirect_info,
bool* defer_redirect) override;
void OnResponseStarted(URLRequest* request, int net_error) override;
void OnReadCompleted(URLRequest* request, int bytes_read) override;
// Clears the URLRequest and timer. Helper for doing work common to
// cancellation and job completion.
void Stop();
// Reads as much data as available from |request|.
void ReadBody(URLRequest* request);
// Helper to copy the partial bytes read from the read IOBuffer to an
// aggregated buffer.
bool ConsumeBytesRead(URLRequest* request, int num_bytes);
// Called when the URLRequest has completed (either success or failure).
void OnUrlRequestCompleted(int net_error);
// Called when the Job has completed. The job may finish in response to a
// timeout, an invalid URL, or the URLRequest completing. By the time this
// method is called, the |response_body_| variable have been assigned.
void OnJobCompleted(Error error);
// Calls r->OnJobCompleted() for each RequestCore |r| currently attached
// to this job, and then clears |requests_|.
void CompleteAndClearRequests(Error error);
// Cancels a request with a specified error code and calls
// OnUrlRequestCompleted().
void FailRequest(Error error);
// The requests attached to this job.
std::vector<scoped_refptr<RequestCore>> requests_;
// The input parameters for starting a URLRequest.
std::unique_ptr<RequestParams> request_params_;
// The URLRequest response information.
std::vector<uint8_t> response_body_;
std::unique_ptr<URLRequest> url_request_;
scoped_refptr<IOBuffer> read_buffer_;
// Used to timeout the job when the URLRequest takes too long. This timer is
// also used for notifying a failure to start the URLRequest.
base::OneShotTimer timer_;
// Non-owned pointer to the AsyncCertNetFetcherImpl that created this job.
AsyncCertNetFetcherImpl* parent_;
DISALLOW_COPY_AND_ASSIGN(Job);
};
void RequestCore::CancelJob() {
if (!task_runner_->RunsTasksInCurrentSequence()) {
task_runner_->PostTask(FROM_HERE,
base::Bind(&RequestCore::CancelJob, this));
return;
}
if (job_) {
auto* job = job_;
job_ = nullptr;
job->DetachRequest(this);
}
SignalImmediateError();
}
void RequestCore::SignalImmediateError() {
// These data members are normally only written on the network thread, but it
// is safe to write here from either thread. This is because
// SignalImmediateError is only to be called before this request is attached
// to a job. In particular, if called from the caller thread, no work will be
// done on the network thread for this request, so these variables will only
// be written and read on the caller thread. If called from the network
// thread, they will only be written to on the network thread and will not be
// read on the caller thread until |completion_event_| is signalled (after
// which it will be not be written on the network thread again).
DCHECK(!job_);
error_ = ERR_ABORTED;
bytes_.clear();
completion_event_.Signal();
}
Job::Job(std::unique_ptr<RequestParams> request_params,
AsyncCertNetFetcherImpl* parent)
: request_params_(std::move(request_params)), parent_(parent) {}
Job::~Job() {
DCHECK(requests_.empty());
Stop();
}
void Job::AttachRequest(scoped_refptr<RequestCore> request) {
request->AttachedToJob(this);
requests_.push_back(std::move(request));
}
void Job::DetachRequest(RequestCore* request) {
std::unique_ptr<Job> delete_this;
auto it = std::find(requests_.begin(), requests_.end(), request);
DCHECK(it != requests_.end());
requests_.erase(it);
// If there are no longer any requests attached to the job then
// cancel and delete it.
if (requests_.empty())
delete_this = parent_->RemoveJob(this);
}
void Job::StartURLRequest(URLRequestContext* context) {
Error error = CanFetchUrl(request_params_->url);
if (error != OK) {
OnJobCompleted(error);
return;
}
// Start the URLRequest.
read_buffer_ = new IOBuffer(kReadBufferSizeInBytes);
net::NetworkTrafficAnnotationTag traffic_annotation =
net::DefineNetworkTrafficAnnotation("certificate_verifier", R"(
semantics {
sender: "Certificate Verifier"
description:
"When verifying certificates, the browser may need to fetch "
"additional URLs that are encoded in the server-provided "
"certificate chain. This may be part of revocation checking ("
"Online Certificate Status Protocol, Certificate Revocation List), "
"or path building (Authority Information Access fetches). Please "
"refer to the following for more on above protocols: "
"https://tools.ietf.org/html/rfc6960, "
"https://tools.ietf.org/html/rfc5280#section-4.2.1.13, and"
"https://tools.ietf.org/html/rfc5280#section-5.2.7."
trigger:
"Verifying a certificate (likely in response to navigating to an "
"'https://' website)."
data:
"In the case of OCSP this may divulge the website being viewed. No "
"user data in other cases."
destination: OTHER
}
policy {
cookies_allowed: NO
setting: "This feature cannot be disabled by settings."
policy_exception_justification: "Not implemented."
})");
url_request_ = context->CreateRequest(request_params_->url, DEFAULT_PRIORITY,
this, traffic_annotation);
if (request_params_->http_method == HTTP_METHOD_POST)
url_request_->set_method("POST");
url_request_->SetLoadFlags(LOAD_DO_NOT_SAVE_COOKIES |
LOAD_DO_NOT_SEND_COOKIES);
url_request_->Start();
// Start a timer to limit how long the job runs for.
if (request_params_->timeout > base::TimeDelta())
timer_.Start(
FROM_HERE, request_params_->timeout,
base::Bind(&Job::FailRequest, base::Unretained(this), ERR_TIMED_OUT));
}
void Job::Cancel() {
// Stop the timer and clear the URLRequest.
Stop();
// Signal attached requests that they've been completed.
CompleteAndClearRequests(static_cast<Error>(ERR_ABORTED));
}
void Job::OnReceivedRedirect(URLRequest* request,
const RedirectInfo& redirect_info,
bool* defer_redirect) {
DCHECK_EQ(url_request_.get(), request);
// Ensure that the new URL matches the policy.
Error error = CanFetchUrl(redirect_info.new_url);
if (error != OK) {
FailRequest(error);
return;
}
}
void Job::OnResponseStarted(URLRequest* request, int net_error) {
DCHECK_EQ(url_request_.get(), request);
DCHECK_NE(ERR_IO_PENDING, net_error);
if (net_error != OK) {
OnUrlRequestCompleted(net_error);
return;
}
if (request->GetResponseCode() != 200) {
// TODO(eroman): Use a more specific error code.
FailRequest(ERR_FAILED);
return;
}
ReadBody(request);
}
void Job::OnReadCompleted(URLRequest* request, int bytes_read) {
DCHECK_EQ(url_request_.get(), request);
DCHECK_NE(ERR_IO_PENDING, bytes_read);
// Keep reading the response body.
if (ConsumeBytesRead(request, bytes_read))
ReadBody(request);
}
void Job::Stop() {
timer_.Stop();
url_request_.reset();
}
void Job::ReadBody(URLRequest* request) {
// Read as many bytes as are available synchronously.
int num_bytes = 0;
while (num_bytes >= 0) {
num_bytes = request->Read(read_buffer_.get(), kReadBufferSizeInBytes);
if (num_bytes == ERR_IO_PENDING)
return;
if (!ConsumeBytesRead(request, num_bytes))
return;
}
OnUrlRequestCompleted(num_bytes);
}
bool Job::ConsumeBytesRead(URLRequest* request, int num_bytes) {
DCHECK_NE(ERR_IO_PENDING, num_bytes);
if (num_bytes <= 0) {
// Error while reading, or EOF.
OnUrlRequestCompleted(num_bytes);
return false;
}
// Enforce maximum size bound.
if (num_bytes + response_body_.size() > request_params_->max_response_bytes) {
FailRequest(ERR_FILE_TOO_BIG);
return false;
}
// Append the data to |response_body_|.
response_body_.reserve(num_bytes);
response_body_.insert(response_body_.end(), read_buffer_->data(),
read_buffer_->data() + num_bytes);
return true;
}
void Job::OnUrlRequestCompleted(int net_error) {
DCHECK_NE(ERR_IO_PENDING, net_error);
Error result = static_cast<Error>(net_error);
OnJobCompleted(result);
}
void Job::OnJobCompleted(Error error) {
DCHECK_NE(ERR_IO_PENDING, error);
// Stop the timer and clear the URLRequest.
Stop();
std::unique_ptr<Job> delete_this = parent_->RemoveJob(this);
CompleteAndClearRequests(error);
}
void Job::CompleteAndClearRequests(Error error) {
for (const auto& request : requests_) {
request->OnJobCompleted(this, error, response_body_);
}
requests_.clear();
}
void Job::FailRequest(Error error) {
DCHECK_NE(ERR_IO_PENDING, error);
int result = url_request_->CancelWithError(error);
OnUrlRequestCompleted(result);
}
AsyncCertNetFetcherImpl::AsyncCertNetFetcherImpl(URLRequestContext* context)
: context_(context) {
// Allow creation to happen from another thread.
thread_checker_.DetachFromThread();
}
AsyncCertNetFetcherImpl::~AsyncCertNetFetcherImpl() {
DCHECK(thread_checker_.CalledOnValidThread());
jobs_.clear();
}
bool JobComparator::operator()(const Job* job1, const Job* job2) const {
return job1->request_params() < job2->request_params();
}
void AsyncCertNetFetcherImpl::Fetch(
std::unique_ptr<RequestParams> request_params,
scoped_refptr<RequestCore> request) {
DCHECK(thread_checker_.CalledOnValidThread());
// If there is an in-progress job that matches the request parameters use it.
// Otherwise start a new job.
Job* job = FindJob(*request_params);
if (job) {
job->AttachRequest(std::move(request));
return;
}
job = new Job(std::move(request_params), this);
jobs_[job] = base::WrapUnique(job);
// Attach the request before calling StartURLRequest; this ensures that the
// request will get signalled if StartURLRequest completes the job
// synchronously.
job->AttachRequest(std::move(request));
job->StartURLRequest(context_);
}
void AsyncCertNetFetcherImpl::Shutdown() {
DCHECK(thread_checker_.CalledOnValidThread());
for (const auto& job : jobs_) {
job.first->Cancel();
}
jobs_.clear();
}
struct JobToRequestParamsComparator {
bool operator()(const JobSet::value_type& job,
const RequestParams& value) const {
return job.first->request_params() < value;
}
};
Job* AsyncCertNetFetcherImpl::FindJob(const RequestParams& params) {
DCHECK(thread_checker_.CalledOnValidThread());
// The JobSet is kept in sorted order so items can be found using binary
// search.
JobSet::iterator it = std::lower_bound(jobs_.begin(), jobs_.end(), params,
JobToRequestParamsComparator());
if (it != jobs_.end() && !(params < (*it).first->request_params()))
return (*it).first;
return nullptr;
}
std::unique_ptr<Job> AsyncCertNetFetcherImpl::RemoveJob(Job* job) {
DCHECK(thread_checker_.CalledOnValidThread());
auto it = jobs_.find(job);
CHECK(it != jobs_.end());
std::unique_ptr<Job> owned_job = std::move(it->second);
jobs_.erase(it);
return owned_job;
}
class CertNetFetcherRequestImpl : public CertNetFetcher::Request {
public:
explicit CertNetFetcherRequestImpl(scoped_refptr<RequestCore> core)
: core_(std::move(core)) {
DCHECK(core_);
}
void WaitForResult(Error* error, std::vector<uint8_t>* bytes) override {
// Should only be called a single time.
DCHECK(core_);
core_->WaitForResult(error, bytes);
core_ = nullptr;
}
~CertNetFetcherRequestImpl() override {
if (core_)
core_->CancelJob();
}
private:
scoped_refptr<RequestCore> core_;
};
class CertNetFetcherImpl : public CertNetFetcher {
public:
explicit CertNetFetcherImpl(URLRequestContext* context)
: task_runner_(base::ThreadTaskRunnerHandle::Get()), context_(context) {}
void Shutdown() override {
DCHECK(task_runner_->RunsTasksInCurrentSequence());
if (impl_) {
impl_->Shutdown();
impl_.reset();
}
context_ = nullptr;
}
std::unique_ptr<Request> FetchCaIssuers(const GURL& url,
int timeout_milliseconds,
int max_response_bytes) override {
std::unique_ptr<RequestParams> request_params(new RequestParams);
request_params->url = url;
request_params->http_method = HTTP_METHOD_GET;
request_params->timeout = GetTimeout(timeout_milliseconds);
request_params->max_response_bytes =
GetMaxResponseBytes(max_response_bytes, kMaxResponseSizeInBytesForAia);
return DoFetch(std::move(request_params));
}
std::unique_ptr<Request> FetchCrl(const GURL& url,
int timeout_milliseconds,
int max_response_bytes) override {
std::unique_ptr<RequestParams> request_params(new RequestParams);
request_params->url = url;
request_params->http_method = HTTP_METHOD_GET;
request_params->timeout = GetTimeout(timeout_milliseconds);
request_params->max_response_bytes =
GetMaxResponseBytes(max_response_bytes, kMaxResponseSizeInBytesForCrl);
return DoFetch(std::move(request_params));
}
WARN_UNUSED_RESULT std::unique_ptr<Request> FetchOcsp(
const GURL& url,
int timeout_milliseconds,
int max_response_bytes) override {
std::unique_ptr<RequestParams> request_params(new RequestParams);
request_params->url = url;
request_params->http_method = HTTP_METHOD_GET;
request_params->timeout = GetTimeout(timeout_milliseconds);
request_params->max_response_bytes =
GetMaxResponseBytes(max_response_bytes, kMaxResponseSizeInBytesForAia);
return DoFetch(std::move(request_params));
}
private:
~CertNetFetcherImpl() override {
// The fetcher must be shutdown (at which point |context_| will be set to
// null) before destruction.
DCHECK(!context_);
}
void DoFetchOnNetworkSequence(std::unique_ptr<RequestParams> request_params,
scoped_refptr<RequestCore> request) {
DCHECK(task_runner_->RunsTasksInCurrentSequence());
if (!context_) {
// The fetcher might have been shutdown between when this task was posted
// and when it is running. In this case, signal the request and do not
// start a network request.
request->SignalImmediateError();
return;
}
if (!impl_) {
impl_.reset(new AsyncCertNetFetcherImpl(context_));
}
impl_->Fetch(std::move(request_params), request);
}
std::unique_ptr<Request> DoFetch(
std::unique_ptr<RequestParams> request_params) {
scoped_refptr<RequestCore> request_core = new RequestCore(task_runner_);
// If the fetcher has already been shutdown, DoFetchOnNetworkSequence will
// signal the request with an error. However, if the fetcher shuts down
// before DoFetchOnNetworkSequence runs and PostTask still returns true,
// then the request will hang (that is, WaitForResult will not return).
if (!task_runner_->PostTask(
FROM_HERE,
base::Bind(&CertNetFetcherImpl::DoFetchOnNetworkSequence, this,
base::Passed(&request_params), request_core))) {
request_core->SignalImmediateError();
}
return std::make_unique<CertNetFetcherRequestImpl>(std::move(request_core));
}
private:
scoped_refptr<base::SingleThreadTaskRunner> task_runner_;
// Not owned. |context_| must stay valid until Shutdown() is called.
URLRequestContext* context_ = nullptr;
std::unique_ptr<AsyncCertNetFetcherImpl> impl_;
};
} // namespace
scoped_refptr<CertNetFetcher> CreateCertNetFetcher(URLRequestContext* context) {
return base::MakeRefCounted<CertNetFetcherImpl>(context);
}
} // namespace net