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/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*-
* vim: set ts=8 sts=2 et sw=2 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 "xpcrtfuzzing/xpcrtfuzzing.h"
#include "mozilla/Assertions.h" // MOZ_CRASH
#include "mozilla/Utf8.h" // mozilla::Utf8Unit
#include <stdio.h> // fflush, fprintf, fputs
#include "FuzzingInterface.h"
#include "jsapi.h"
#include "js/CompilationAndEvaluation.h" // JS::Evaluate
#include "js/CompileOptions.h" // JS::CompileOptions
#include "js/Conversions.h" // JS::Conversions
#include "js/ErrorReport.h" // JS::PrintError
#include "js/Exception.h" // JS::StealPendingExceptionStack
#include "js/experimental/TypedData.h" // JS_GetUint8ClampedArrayData, JS_NewUint8ClampedArray
#include "js/PropertyAndElement.h" // JS_SetProperty, JS_HasOwnProperty
#include "js/RootingAPI.h" // JS::Rooted
#include "js/SourceText.h" // JS::Source{Ownership,Text}
#include "js/Value.h" // JS::Value
using mozilla::dom::AutoJSAPI;
static AutoJSAPI* gJsapi = nullptr;
static std::string gFuzzModuleName;
static void CrashOnPendingException() {
if (gJsapi->HasException()) {
gJsapi->ReportException();
MOZ_CRASH("Unhandled exception from JS runtime!");
}
}
int FuzzXPCRuntimeStart(AutoJSAPI* jsapi, int* argc, char*** argv,
LibFuzzerDriver fuzzerDriver) {
gFuzzModuleName = getenv("FUZZER");
gJsapi = jsapi;
int ret = FuzzXPCRuntimeInit();
if (ret) {
fprintf(stderr, "Fuzzing Interface: Error: Initialize callback failed\n");
return ret;
}
ret = fuzzerDriver(argc, argv, FuzzXPCRuntimeFuzz);
if (!ret) {
fprintf(stdout, "Trying to shutdown!\n");
int shutdown = FuzzXPCRuntimeShutdown();
if (shutdown) {
fprintf(stderr, "Fuzzing Interface: Error: Shutdown callback failed\n");
return shutdown;
}
}
return ret;
}
int FuzzXPCRuntimeInit() {
JSContext* cx = gJsapi->cx();
JS::Rooted<JS::Value> v(cx);
JS::CompileOptions opts(cx);
// Load the fuzzing module specified in the FUZZER environment variable
JS::EvaluateUtf8Path(cx, opts, gFuzzModuleName.c_str(), &v);
// Any errors while loading the fuzzing module should be fatal
CrashOnPendingException();
return 0;
}
int FuzzXPCRuntimeFuzz(const uint8_t* buf, size_t size) {
if (!size) {
return 0;
}
JSContext* cx = gJsapi->cx();
JS::Rooted<JSObject*> arr(cx, JS_NewUint8ClampedArray(cx, size));
if (!arr) {
MOZ_CRASH("OOM");
}
do {
JS::AutoCheckCannotGC nogc;
bool isShared;
uint8_t* data = JS_GetUint8ClampedArrayData(arr, &isShared, nogc);
MOZ_RELEASE_ASSERT(!isShared);
memcpy(data, buf, size);
} while (false);
JS::Rooted<JSObject*> global(cx, JS::CurrentGlobalOrNull(cx));
JS::RootedValue arrVal(cx, JS::ObjectValue(*arr));
if (!JS_SetProperty(cx, global, "fuzzBuf", arrVal)) {
MOZ_CRASH("JS_SetProperty failed");
}
JS::Rooted<JS::Value> v(cx);
JS::CompileOptions opts(cx);
static const char data[] = "JSFuzzIterate();";
JS::SourceText<mozilla::Utf8Unit> srcBuf;
if (!srcBuf.init(cx, data, strlen(data), JS::SourceOwnership::Borrowed)) {
return 1;
}
if (!JS::Evaluate(cx, opts.setFileAndLine(__FILE__, __LINE__), srcBuf, &v) &&
!JS_IsExceptionPending(cx)) {
// A return value of `false` without a pending exception indicates
// a timeout as triggered by the `timeout` shell function.
return 1;
}
// The fuzzing module is required to handle any exceptions
CrashOnPendingException();
int32_t ret = 0;
if (!ToInt32(cx, v, &ret)) {
MOZ_CRASH("Must return an int32 compatible return value!");
}
return ret;
}
int FuzzXPCRuntimeShutdown() {
JSContext* cx = gJsapi->cx();
JS::Rooted<JS::Value> v(cx);
JS::CompileOptions opts(cx);
JS::Rooted<JSObject*> global(cx, JS::CurrentGlobalOrNull(cx));
bool found = false;
if (JS_HasOwnProperty(cx, global, "JSFuzzShutdown", &found)) {
if (found) {
static const char data[] = "JSFuzzShutdown();";
JS::SourceText<mozilla::Utf8Unit> srcBuf;
if (!srcBuf.init(cx, data, strlen(data), JS::SourceOwnership::Borrowed)) {
return 1;
}
if (!JS::Evaluate(cx, opts.setFileAndLine(__FILE__, __LINE__), srcBuf,
&v) &&
!JS_IsExceptionPending(cx)) {
// A return value of `false` without a pending exception indicates
// a timeout as triggered by the `timeout` shell function.
return 1;
}
}
}
// The fuzzing module is required to handle any exceptions
CrashOnPendingException();
return 0;
}
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