Source code

Revision control

Other Tools

/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
* file, You can obtain one at http://mozilla.org/MPL/2.0/. */
#include "nsDNSPrefetch.h"
#include "nsCOMPtr.h"
#include "nsString.h"
#include "nsThreadUtils.h"
#include "nsIDNSListener.h"
#include "nsIDNSService.h"
#include "nsICancelable.h"
#include "nsIURI.h"
#include "mozilla/Atomics.h"
#include "mozilla/Preferences.h"
static nsIDNSService* sDNSService = nullptr;
static mozilla::Atomic<bool, mozilla::Relaxed> sESNIEnabled(false);
const char kESNIPref[] = "network.security.esni.enabled";
nsresult nsDNSPrefetch::Initialize(nsIDNSService* aDNSService) {
MOZ_ASSERT(NS_IsMainThread());
NS_IF_RELEASE(sDNSService);
sDNSService = aDNSService;
NS_IF_ADDREF(sDNSService);
mozilla::Preferences::RegisterCallback(nsDNSPrefetch::PrefChanged, kESNIPref);
PrefChanged(nullptr, nullptr);
return NS_OK;
}
nsresult nsDNSPrefetch::Shutdown() {
NS_IF_RELEASE(sDNSService);
mozilla::Preferences::UnregisterCallback(nsDNSPrefetch::PrefChanged,
kESNIPref);
return NS_OK;
}
// static
void nsDNSPrefetch::PrefChanged(const char* aPref, void* aClosure) {
if (!aPref || strcmp(aPref, kESNIPref) == 0) {
bool enabled = false;
if (NS_SUCCEEDED(mozilla::Preferences::GetBool(kESNIPref, &enabled))) {
sESNIEnabled = enabled;
}
}
}
nsDNSPrefetch::nsDNSPrefetch(nsIURI* aURI,
mozilla::OriginAttributes& aOriginAttributes,
nsIRequest::TRRMode aTRRMode,
nsIDNSListener* aListener, bool storeTiming)
: mOriginAttributes(aOriginAttributes),
mStoreTiming(storeTiming),
mTRRMode(aTRRMode),
mListener(do_GetWeakReference(aListener)) {
aURI->GetAsciiHost(mHostname);
mIsHttps = aURI->SchemeIs("https");
}
nsresult nsDNSPrefetch::Prefetch(uint32_t flags) {
if (mHostname.IsEmpty()) return NS_ERROR_NOT_AVAILABLE;
if (!sDNSService) return NS_ERROR_NOT_AVAILABLE;
nsCOMPtr<nsICancelable> tmpOutstanding;
if (mStoreTiming) mStartTimestamp = mozilla::TimeStamp::Now();
// If AsyncResolve fails, for example because prefetching is disabled,
// then our timing will be useless. However, in such a case,
// mEndTimestamp will be a null timestamp and callers should check
// TimingsValid() before using the timing.
nsCOMPtr<nsIEventTarget> target = mozilla::GetCurrentThreadEventTarget();
flags |= nsIDNSService::GetFlagsFromTRRMode(mTRRMode);
nsresult rv = sDNSService->AsyncResolveNative(
mHostname, flags | nsIDNSService::RESOLVE_SPECULATE, this, target,
mOriginAttributes, getter_AddRefs(tmpOutstanding));
if (NS_FAILED(rv)) {
return rv;
}
// Fetch esni keys if needed.
if (sESNIEnabled && mIsHttps) {
nsAutoCString esniHost;
esniHost.Append("_esni.");
esniHost.Append(mHostname);
sDNSService->AsyncResolveByTypeNative(
esniHost, nsIDNSService::RESOLVE_TYPE_TXT,
flags | nsIDNSService::RESOLVE_SPECULATE, this, target,
mOriginAttributes, getter_AddRefs(tmpOutstanding));
}
return NS_OK;
}
nsresult nsDNSPrefetch::PrefetchLow(bool refreshDNS) {
return Prefetch(nsIDNSService::RESOLVE_PRIORITY_LOW |
(refreshDNS ? nsIDNSService::RESOLVE_BYPASS_CACHE : 0));
}
nsresult nsDNSPrefetch::PrefetchMedium(bool refreshDNS) {
return Prefetch(nsIDNSService::RESOLVE_PRIORITY_MEDIUM |
(refreshDNS ? nsIDNSService::RESOLVE_BYPASS_CACHE : 0));
}
nsresult nsDNSPrefetch::PrefetchHigh(bool refreshDNS) {
return Prefetch(refreshDNS ? nsIDNSService::RESOLVE_BYPASS_CACHE : 0);
}
NS_IMPL_ISUPPORTS(nsDNSPrefetch, nsIDNSListener)
NS_IMETHODIMP
nsDNSPrefetch::OnLookupComplete(nsICancelable* request, nsIDNSRecord* rec,
nsresult status) {
if (mStoreTiming) {
mEndTimestamp = mozilla::TimeStamp::Now();
}
nsCOMPtr<nsIDNSListener> listener = do_QueryReferent(mListener);
if (listener) {
listener->OnLookupComplete(request, rec, status);
}
// OnLookupComplete should be called on the target thread, so we release
// mListener here to make sure mListener is also released on the target
// thread.
mListener = nullptr;
return NS_OK;
}