gecko-dev/js/ipc/JavaScriptParent.cpp

145 строки
4.3 KiB
C++

/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*-
* vim: set ts=4 sw=2 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 "JavaScriptParent.h"
#include "mozilla/dom/ContentParent.h"
#include "mozilla/dom/ScriptSettings.h"
#include "nsJSUtils.h"
#include "nsIConsoleService.h"
#include "nsIScriptError.h"
#include "jsfriendapi.h"
#include "js/Proxy.h"
#include "js/HeapAPI.h"
#include "js/Wrapper.h"
#include "xpcprivate.h"
#include "mozilla/Casting.h"
#include "mozilla/StaticPrefs_dom.h"
#include "mozilla/Telemetry.h"
using namespace js;
using namespace JS;
using namespace mozilla;
using namespace mozilla::jsipc;
using namespace mozilla::dom;
static void TraceParent(JSTracer* trc, void* data) {
static_cast<JavaScriptParent*>(data)->trace(trc);
}
JavaScriptParent::JavaScriptParent() : savedNextCPOWNumber_(1) {
JS_AddExtraGCRootsTracer(danger::GetJSContext(), TraceParent, this);
}
JavaScriptParent::~JavaScriptParent() {
JS_RemoveExtraGCRootsTracer(danger::GetJSContext(), TraceParent, this);
}
static bool ForbidUnsafeBrowserCPOWs() {
return StaticPrefs::dom_ipc_cpows_forbid_unsafe_from_browser();
}
bool JavaScriptParent::allowMessage(JSContext* cx) {
MOZ_ASSERT(cx);
// If we're running browser code while running tests (in automation),
// then we allow all safe CPOWs and forbid unsafe CPOWs
// based on a pref (which defaults to forbidden).
// A normal (release) browser build will never allow CPOWs,
// except as a token to pass round.
if (!xpc::IsInAutomation()) {
JS_ReportErrorASCII(cx, "CPOW usage forbidden");
return false;
}
MessageChannel* channel = GetIPCChannel();
bool isSafe = channel->IsInTransaction();
if (isSafe) {
return true;
}
nsIGlobalObject* global = dom::GetIncumbentGlobal();
JS::Rooted<JSObject*> jsGlobal(
cx, global ? global->GetGlobalJSObject() : nullptr);
if (jsGlobal) {
JSAutoRealm ar(cx, jsGlobal);
if (ForbidUnsafeBrowserCPOWs()) {
JS_ReportErrorASCII(cx, "unsafe CPOW usage forbidden");
return false;
}
}
static bool disableUnsafeCPOWWarnings =
PR_GetEnv("DISABLE_UNSAFE_CPOW_WARNINGS");
if (!disableUnsafeCPOWWarnings) {
nsCOMPtr<nsIConsoleService> console(
do_GetService(NS_CONSOLESERVICE_CONTRACTID));
if (console) {
nsAutoString filename;
uint32_t lineno = 0, column = 0;
nsJSUtils::GetCallingLocation(cx, filename, &lineno, &column);
nsCOMPtr<nsIScriptError> error(
do_CreateInstance(NS_SCRIPTERROR_CONTRACTID));
error->Init(NS_LITERAL_STRING("unsafe/forbidden CPOW usage"), filename,
EmptyString(), lineno, column, nsIScriptError::warningFlag,
"chrome javascript", false /* from private window */,
true /* from chrome context */);
console->LogMessage(error);
} else {
NS_WARNING("Unsafe synchronous IPC message");
}
}
return true;
}
void JavaScriptParent::trace(JSTracer* trc) {
objects_.trace(trc);
unwaivedObjectIds_.trace(trc);
waivedObjectIds_.trace(trc);
}
JSObject* JavaScriptParent::scopeForTargetObjects() {
// CPOWs from the child need to point into the parent's unprivileged junk
// scope so that a compromised child cannot compromise the parent. In
// practice, this means that a child process can only (a) hold parent
// objects alive and (b) invoke them if they are callable.
return xpc::UnprivilegedJunkScope();
}
void JavaScriptParent::afterProcessTask() {
if (savedNextCPOWNumber_ == nextCPOWNumber_) {
return;
}
savedNextCPOWNumber_ = nextCPOWNumber_;
MOZ_ASSERT(nextCPOWNumber_ > 0);
if (active()) {
Unused << SendDropTemporaryStrongReferences(nextCPOWNumber_ - 1);
}
}
PJavaScriptParent* mozilla::jsipc::NewJavaScriptParent() {
return new JavaScriptParent();
}
void mozilla::jsipc::ReleaseJavaScriptParent(PJavaScriptParent* parent) {
static_cast<JavaScriptParent*>(parent)->decref();
}
void mozilla::jsipc::AfterProcessTask() {
for (auto* cp : ContentParent::AllProcesses(ContentParent::eLive)) {
if (PJavaScriptParent* p =
LoneManagedOrNullAsserts(cp->ManagedPJavaScriptParent())) {
static_cast<JavaScriptParent*>(p)->afterProcessTask();
}
}
}