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/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* vim: set sw=2 ts=8 et tw=80 : */
/* 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 "EarlyHintsService.h"
#include "EarlyHintPreconnect.h"
#include "EarlyHintPreloader.h"
#include "mozilla/PreloadHashKey.h"
#include "mozilla/Telemetry.h"
#include "mozilla/glean/GleanMetrics.h"
#include "nsContentUtils.h"
#include "nsIChannel.h"
#include "nsICookieJarSettings.h"
#include "nsILoadInfo.h"
#include "nsIPrincipal.h"
#include "nsNetUtil.h"
#include "nsString.h"
namespace mozilla::net {
EarlyHintsService::EarlyHintsService()
: mOngoingEarlyHints(new OngoingEarlyHints()) {}
// implementing the destructor in the .cpp file to allow EarlyHintsService.h
// not to include EarlyHintPreloader.h, decoupling the two files and hopefully
// allow faster compile times
EarlyHintsService::~EarlyHintsService() = default;
void EarlyHintsService::EarlyHint(const nsACString& aLinkHeader,
nsIURI* aBaseURI, nsIChannel* aChannel,
const nsACString& aReferrerPolicy,
const nsACString& aCSPHeader) {
mEarlyHintsCount++;
if (mFirstEarlyHint.isNothing()) {
mFirstEarlyHint.emplace(TimeStamp::NowLoRes());
} else {
// Only allow one early hint response with link headers. See
// https://html.spec.whatwg.org/multipage/semantics.html#early-hints
// > Note: Only the first early hint response served during the navigation
// > is handled, and it is discarded if it is succeeded by a cross-origin
// > redirect.
return;
}
nsCOMPtr<nsILoadInfo> loadInfo = aChannel->LoadInfo();
// We only follow Early Hints sent on the main document. Make sure that we got
// the main document channel here.
if (loadInfo->GetExternalContentPolicyType() !=
ExtContentPolicy::TYPE_DOCUMENT) {
MOZ_ASSERT(false, "Early Hint on non-document channel");
return;
}
nsCOMPtr<nsIPrincipal> principal;
// We want to set the top-level document as the triggeringPrincipal for the
// load of the sub-resources (image, font, fetch, script, style, fetch and in
// the future maybe more). We can't use the `triggeringPrincipal` of the main
// document channel, because it is the `systemPrincipal` for user initiated
// loads. Same for the `LoadInfo::FindPrincipalToInherit(aChannel)`.
//
// On 3xx redirects of the main document to cross site locations, all Early
// Hint preloads get cancelled as specified in the whatwg spec:
//
// Note: Only the first early hint response served during the navigation is
// handled, and it is discarded if it is succeeded by a cross-origin
// redirect. [1]
//
// Therefore the channel doesn't need to change the principal for any reason
// and has the correct principal for the whole lifetime.
//
// [1]: https://html.spec.whatwg.org/multipage/semantics.html#early-hints
nsresult rv = nsContentUtils::GetSecurityManager()->GetChannelResultPrincipal(
aChannel, getter_AddRefs(principal));
NS_ENSURE_SUCCESS_VOID(rv);
nsCOMPtr<nsICookieJarSettings> cookieJarSettings;
if (NS_FAILED(
loadInfo->GetCookieJarSettings(getter_AddRefs(cookieJarSettings)))) {
return;
}
// TODO: find out why LinkHeaderParser uses utf16 and check if it can be
// changed to utf8
auto linkHeaders = ParseLinkHeader(NS_ConvertUTF8toUTF16(aLinkHeader));
for (auto& linkHeader : linkHeaders) {
CollectLinkTypeTelemetry(linkHeader.mRel);
if (linkHeader.mRel.LowerCaseEqualsLiteral("preconnect")) {
EarlyHintPreconnect::MaybePreconnect(linkHeader, aBaseURI, principal);
} else if (linkHeader.mRel.LowerCaseEqualsLiteral("preload")) {
EarlyHintPreloader::MaybeCreateAndInsertPreload(
mOngoingEarlyHints, linkHeader, aBaseURI, principal,
cookieJarSettings, aReferrerPolicy, aCSPHeader);
}
}
}
void EarlyHintsService::FinalResponse(uint32_t aResponseStatus) {
// We will collect telemetry mosly once for a document.
// In case of a reddirect this will be called multiple times.
CollectTelemetry(Some(aResponseStatus));
}
void EarlyHintsService::Cancel(const nsACString& aReason) {
CollectTelemetry(Nothing());
mOngoingEarlyHints->CancelAllOngoingPreloads(aReason);
}
void EarlyHintsService::RegisterLinksAndGetConnectArgs(
nsTArray<EarlyHintConnectArgs>& aOutLinks) {
mOngoingEarlyHints->RegisterLinksAndGetConnectArgs(aOutLinks);
}
void EarlyHintsService::CollectTelemetry(Maybe<uint32_t> aResponseStatus) {
// EH_NUM_OF_HINTS_PER_PAGE is only collected for the 2xx responses,
// regardless of the number of received mEarlyHintsCount.
// Other telemetry probes are only collected if there was at least one
// EarlyHins response.
if (aResponseStatus && (*aResponseStatus <= 299)) {
Telemetry::Accumulate(Telemetry::EH_NUM_OF_HINTS_PER_PAGE,
mEarlyHintsCount);
}
if (mEarlyHintsCount == 0) {
return;
}
Telemetry::LABELS_EH_FINAL_RESPONSE label =
Telemetry::LABELS_EH_FINAL_RESPONSE::Cancel;
if (aResponseStatus) {
if (*aResponseStatus <= 299) {
label = Telemetry::LABELS_EH_FINAL_RESPONSE::R2xx;
MOZ_ASSERT(mFirstEarlyHint);
Telemetry::AccumulateTimeDelta(Telemetry::EH_TIME_TO_FINAL_RESPONSE,
*mFirstEarlyHint, TimeStamp::NowLoRes());
} else if (*aResponseStatus <= 399) {
label = Telemetry::LABELS_EH_FINAL_RESPONSE::R3xx;
} else if (*aResponseStatus <= 499) {
label = Telemetry::LABELS_EH_FINAL_RESPONSE::R4xx;
} else {
label = Telemetry::LABELS_EH_FINAL_RESPONSE::Other;
}
}
Telemetry::AccumulateCategorical(label);
// Reset telemetry counters and timestamps.
mEarlyHintsCount = 0;
mFirstEarlyHint = Nothing();
}
void EarlyHintsService::CollectLinkTypeTelemetry(const nsAString& aRel) {
if (aRel.LowerCaseEqualsLiteral("dns-prefetch")) {
glean::netwerk::eh_link_type.Get("dns-prefetch"_ns).Add(1);
} else if (aRel.LowerCaseEqualsLiteral("icon")) {
glean::netwerk::eh_link_type.Get("icon"_ns).Add(1);
} else if (aRel.LowerCaseEqualsLiteral("modulepreload")) {
glean::netwerk::eh_link_type.Get("modulepreload"_ns).Add(1);
} else if (aRel.LowerCaseEqualsLiteral("preconnect")) {
glean::netwerk::eh_link_type.Get("preconnect"_ns).Add(1);
} else if (aRel.LowerCaseEqualsLiteral("prefetch")) {
glean::netwerk::eh_link_type.Get("prefetch"_ns).Add(1);
} else if (aRel.LowerCaseEqualsLiteral("preload")) {
glean::netwerk::eh_link_type.Get("preload"_ns).Add(1);
} else if (aRel.LowerCaseEqualsLiteral("prerender")) {
glean::netwerk::eh_link_type.Get("prerender"_ns).Add(1);
} else if (aRel.LowerCaseEqualsLiteral("stylesheet")) {
glean::netwerk::eh_link_type.Get("stylesheet"_ns).Add(1);
} else {
glean::netwerk::eh_link_type.Get("other"_ns).Add(1);
}
}
} // namespace mozilla::net
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