blob: bc3a810aae74d3923ad9e6b471b45ac1f9bf51e9 [file] [log] [blame]
// Copyright (c) 2012 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
#include "extensions/browser/extension_throttle_manager.h"
#include <utility>
#include "base/logging.h"
#include "base/memory/ptr_util.h"
#include "base/metrics/field_trial.h"
#include "base/metrics/histogram.h"
#include "base/strings/string_util.h"
#include "extensions/browser/extension_request_limiting_throttle.h"
#include "extensions/common/constants.h"
#include "net/base/url_util.h"
#include "net/log/net_log.h"
#include "net/log/net_log_event_type.h"
#include "net/log/net_log_source_type.h"
#include "net/url_request/url_request.h"
namespace extensions {
const unsigned int ExtensionThrottleManager::kMaximumNumberOfEntries = 1500;
const unsigned int ExtensionThrottleManager::kRequestsBetweenCollecting = 200;
ExtensionThrottleManager::ExtensionThrottleManager()
: requests_since_last_gc_(0),
enable_thread_checks_(false),
logged_for_localhost_disabled_(false),
registered_from_thread_(base::kInvalidThreadId),
ignore_user_gesture_load_flag_for_tests_(false) {
url_id_replacements_.ClearPassword();
url_id_replacements_.ClearUsername();
url_id_replacements_.ClearQuery();
url_id_replacements_.ClearRef();
net::NetworkChangeNotifier::AddIPAddressObserver(this);
net::NetworkChangeNotifier::AddConnectionTypeObserver(this);
}
ExtensionThrottleManager::~ExtensionThrottleManager() {
DCHECK_CALLED_ON_VALID_SEQUENCE(sequence_checker_);
net::NetworkChangeNotifier::RemoveIPAddressObserver(this);
net::NetworkChangeNotifier::RemoveConnectionTypeObserver(this);
// Since the manager object might conceivably go away before the
// entries, detach the entries' back-pointer to the manager.
UrlEntryMap::iterator i = url_entries_.begin();
while (i != url_entries_.end()) {
if (i->second.get() != NULL) {
i->second->DetachManager();
}
++i;
}
// Delete all entries.
url_entries_.clear();
}
std::unique_ptr<content::ResourceThrottle>
ExtensionThrottleManager::MaybeCreateThrottle(const net::URLRequest* request) {
if (request->first_party_for_cookies().scheme() !=
extensions::kExtensionScheme) {
return nullptr;
}
return base::MakeUnique<extensions::ExtensionRequestLimitingThrottle>(request,
this);
}
scoped_refptr<ExtensionThrottleEntryInterface>
ExtensionThrottleManager::RegisterRequestUrl(const GURL& url) {
#if DCHECK_IS_ON()
DCHECK(!enable_thread_checks_ || sequence_checker_.CalledOnValidSequence());
#endif // DCHECK_IS_ON()
// Normalize the url.
std::string url_id = GetIdFromUrl(url);
// Periodically garbage collect old entries.
GarbageCollectEntriesIfNecessary();
// Find the entry in the map or create a new NULL entry.
scoped_refptr<ExtensionThrottleEntry>& entry = url_entries_[url_id];
// If the entry exists but could be garbage collected at this point, we
// start with a fresh entry so that we possibly back off a bit less
// aggressively (i.e. this resets the error count when the entry's URL
// hasn't been requested in long enough).
if (entry.get() && entry->IsEntryOutdated()) {
entry = NULL;
}
// Create the entry if needed.
if (entry.get() == NULL) {
if (backoff_policy_for_tests_) {
entry = new ExtensionThrottleEntry(
this, url_id, backoff_policy_for_tests_.get(),
ignore_user_gesture_load_flag_for_tests_);
} else {
entry = new ExtensionThrottleEntry(
this, url_id, ignore_user_gesture_load_flag_for_tests_);
}
// We only disable back-off throttling on an entry that we have
// just constructed. This is to allow unit tests to explicitly override
// the entry for localhost URLs.
std::string host = url.host();
if (net::IsLocalhost(host)) {
if (!logged_for_localhost_disabled_ && net::IsLocalhost(host)) {
logged_for_localhost_disabled_ = true;
net_log_.AddEvent(net::NetLogEventType::THROTTLING_DISABLED_FOR_HOST,
net::NetLog::StringCallback("host", &host));
}
// TODO(joi): Once sliding window is separate from back-off throttling,
// we can simply return a dummy implementation of
// ExtensionThrottleEntryInterface here that never blocks anything.
entry->DisableBackoffThrottling();
}
}
return entry;
}
void ExtensionThrottleManager::SetBackoffPolicyForTests(
std::unique_ptr<net::BackoffEntry::Policy> policy) {
backoff_policy_for_tests_ = std::move(policy);
}
void ExtensionThrottleManager::OverrideEntryForTests(
const GURL& url,
ExtensionThrottleEntry* entry) {
// Normalize the url.
std::string url_id = GetIdFromUrl(url);
// Periodically garbage collect old entries.
GarbageCollectEntriesIfNecessary();
url_entries_[url_id] = entry;
}
void ExtensionThrottleManager::EraseEntryForTests(const GURL& url) {
// Normalize the url.
std::string url_id = GetIdFromUrl(url);
url_entries_.erase(url_id);
}
void ExtensionThrottleManager::SetIgnoreUserGestureLoadFlagForTests(
bool ignore_user_gesture_load_flag_for_tests) {
ignore_user_gesture_load_flag_for_tests_ = true;
}
void ExtensionThrottleManager::set_enable_thread_checks(bool enable) {
enable_thread_checks_ = enable;
}
bool ExtensionThrottleManager::enable_thread_checks() const {
return enable_thread_checks_;
}
void ExtensionThrottleManager::set_net_log(net::NetLog* net_log) {
DCHECK(net_log);
net_log_ = net::NetLogWithSource::Make(
net_log, net::NetLogSourceType::EXPONENTIAL_BACKOFF_THROTTLING);
}
net::NetLog* ExtensionThrottleManager::net_log() const {
return net_log_.net_log();
}
void ExtensionThrottleManager::OnIPAddressChanged() {
OnNetworkChange();
}
void ExtensionThrottleManager::OnConnectionTypeChanged(
net::NetworkChangeNotifier::ConnectionType type) {
OnNetworkChange();
}
std::string ExtensionThrottleManager::GetIdFromUrl(const GURL& url) const {
if (!url.is_valid())
return url.possibly_invalid_spec();
GURL id = url.ReplaceComponents(url_id_replacements_);
return base::ToLowerASCII(id.spec());
}
void ExtensionThrottleManager::GarbageCollectEntriesIfNecessary() {
requests_since_last_gc_++;
if (requests_since_last_gc_ < kRequestsBetweenCollecting)
return;
requests_since_last_gc_ = 0;
GarbageCollectEntries();
}
void ExtensionThrottleManager::GarbageCollectEntries() {
UrlEntryMap::iterator i = url_entries_.begin();
while (i != url_entries_.end()) {
if ((i->second)->IsEntryOutdated()) {
url_entries_.erase(i++);
} else {
++i;
}
}
// In case something broke we want to make sure not to grow indefinitely.
while (url_entries_.size() > kMaximumNumberOfEntries) {
url_entries_.erase(url_entries_.begin());
}
}
void ExtensionThrottleManager::OnNetworkChange() {
// Remove all entries. Any entries that in-flight requests have a reference
// to will live until those requests end, and these entries may be
// inconsistent with new entries for the same URLs, but since what we
// want is a clean slate for the new connection type, this is OK.
url_entries_.clear();
requests_since_last_gc_ = 0;
}
} // namespace extensions