The Tor Browser: js/xpconnect/loader/mozJSSubScriptLoader.cpp@b8a032363ba2 (annotated)

js/xpconnect/loader/mozJSSubScriptLoader.cpp@b8a032363ba2 (annotated)

js/xpconnect/loader/mozJSSubScriptLoader.cpp

Thu, 22 Jan 2015 13:21:57 +0100

author: Michael Schloh von Bennewitz <michael@schloh.com>
date: Thu, 22 Jan 2015 13:21:57 +0100
branch: TOR_BUG_9701
changeset 15: b8a032363ba2
permissions: -rw-r--r--

Incorporate requested changes from Mozilla in review:
https://bugzilla.mozilla.org/show_bug.cgi?id=1123480#c6

 /* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
 /* vim: set ts=8 sts=4 et sw=4 tw=99: */
 /* 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 "mozJSSubScriptLoader.h"
 #include "mozJSComponentLoader.h"
 #include "mozJSLoaderUtils.h"
 #include "nsIURI.h"
 #include "nsIIOService.h"
 #include "nsIChannel.h"
 #include "nsIInputStream.h"
 #include "nsNetCID.h"
 #include "nsNetUtil.h"
 #include "nsIFileURL.h"
 #include "nsScriptLoader.h"
 #include "nsIScriptSecurityManager.h"
 #include "nsThreadUtils.h"
 #include "jsapi.h"
 #include "jsfriendapi.h"
 #include "js/OldDebugAPI.h"
 #include "nsJSPrincipals.h"
 #include "xpcpublic.h" // For xpc::SystemErrorReporter
 #include "xpcprivate.h" // For xpc::OptionsBase
 #include "jswrapper.h"
 #include "mozilla/scache/StartupCache.h"
 #include "mozilla/scache/StartupCacheUtils.h"
 #include "mozilla/unused.h"
 using namespace mozilla::scache;
 using namespace JS;
 using namespace xpc;
 using namespace mozilla;
 class MOZ_STACK_CLASS LoadSubScriptOptions : public OptionsBase {
 public:
     LoadSubScriptOptions(JSContext *cx = xpc_GetSafeJSContext(),
                          JSObject *options = nullptr)
         : OptionsBase(cx, options)
         , target(cx)
         , charset(NullString())
         , ignoreCache(false)
     { }
     virtual bool Parse() {
       return ParseObject("target", &target) &&
              ParseString("charset", charset) &&
              ParseBoolean("ignoreCache", &ignoreCache);
     }
     RootedObject target;
     nsString charset;
     bool ignoreCache;
 };
 /* load() error msgs, XXX localize? */
 #define LOAD_ERROR_NOSERVICE "Error creating IO Service."
 #define LOAD_ERROR_NOURI "Error creating URI (invalid URL scheme?)"
 #define LOAD_ERROR_NOSCHEME "Failed to get URI scheme.  This is bad."
 #define LOAD_ERROR_URI_NOT_LOCAL "Trying to load a non-local URI."
 #define LOAD_ERROR_NOSTREAM  "Error opening input stream (invalid filename?)"
 #define LOAD_ERROR_NOCONTENT "ContentLength not available (not a local URL?)"
 #define LOAD_ERROR_BADCHARSET "Error converting to specified charset"
 #define LOAD_ERROR_BADREAD   "File Read Error."
 #define LOAD_ERROR_READUNDERFLOW "File Read Error (underflow.)"
 #define LOAD_ERROR_NOPRINCIPALS "Failed to get principals."
 #define LOAD_ERROR_NOSPEC "Failed to get URI spec.  This is bad."
 #define LOAD_ERROR_CONTENTTOOBIG "ContentLength is too large"
 mozJSSubScriptLoader::mozJSSubScriptLoader() : mSystemPrincipal(nullptr)
 {
     // Force construction of the JS component loader.  We may need it later.
     nsCOMPtr<xpcIJSModuleLoader> componentLoader =
         do_GetService(MOZJSCOMPONENTLOADER_CONTRACTID);
 }
 mozJSSubScriptLoader::~mozJSSubScriptLoader()
 {
     /* empty */
 }
 NS_IMPL_ISUPPORTS(mozJSSubScriptLoader, mozIJSSubScriptLoader)
 static nsresult
 ReportError(JSContext *cx, const char *msg)
 {
     RootedValue exn(cx, JS::StringValue(JS_NewStringCopyZ(cx, msg)));
     JS_SetPendingException(cx, exn);
     return NS_OK;
 }
 nsresult
 mozJSSubScriptLoader::ReadScript(nsIURI *uri, JSContext *cx, JSObject *targetObjArg,
                                  const nsAString &charset, const char *uriStr,
                                  nsIIOService *serv, nsIPrincipal *principal,
                                  bool reuseGlobal, JS::MutableHandleScript script,
                                  JS::MutableHandleFunction function)
 {
     RootedObject target_obj(cx, targetObjArg);
     script.set(nullptr);
     function.set(nullptr);
     // Instead of calling NS_OpenURI, we create the channel ourselves and call
     // SetContentType, to avoid expensive MIME type lookups (bug 632490).
     nsCOMPtr<nsIChannel> chan;
     nsCOMPtr<nsIInputStream> instream;
     nsresult rv = NS_NewChannel(getter_AddRefs(chan), uri, serv,
                                 nullptr, nullptr, nsIRequest::LOAD_NORMAL);
     if (NS_SUCCEEDED(rv)) {
         chan->SetContentType(NS_LITERAL_CSTRING("application/javascript"));
         rv = chan->Open(getter_AddRefs(instream));
     }
     if (NS_FAILED(rv)) {
         return ReportError(cx, LOAD_ERROR_NOSTREAM);
     }
     int64_t len = -1;
     rv = chan->GetContentLength(&len);
     if (NS_FAILED(rv) || len == -1) {
         return ReportError(cx, LOAD_ERROR_NOCONTENT);
     }
     if (len > INT32_MAX) {
         return ReportError(cx, LOAD_ERROR_CONTENTTOOBIG);
     }
     nsCString buf;
     rv = NS_ReadInputStreamToString(instream, buf, len);
     if (NS_FAILED(rv))
         return rv;
     /* set our own error reporter so we can report any bad things as catchable
      * exceptions, including the source/line number */
     JSErrorReporter er = JS_SetErrorReporter(cx, xpc::SystemErrorReporter);
     JS::CompileOptions options(cx);
     options.setFileAndLine(uriStr, 1);
     if (!charset.IsVoid()) {
         jschar *scriptBuf = nullptr;
         size_t scriptLength = 0;
         rv = nsScriptLoader::ConvertToUTF16(nullptr, reinterpret_cast<const uint8_t*>(buf.get()), len,
                                             charset, nullptr, scriptBuf, scriptLength);
         JS::SourceBufferHolder srcBuf(scriptBuf, scriptLength,
                                       JS::SourceBufferHolder::GiveOwnership);
         if (NS_FAILED(rv)) {
             return ReportError(cx, LOAD_ERROR_BADCHARSET);
         }
         if (!reuseGlobal) {
             JS::Compile(cx, target_obj, options, srcBuf, script);
         } else {
             JS::CompileFunction(cx, target_obj, options,
                                 nullptr, 0, nullptr,
                                 srcBuf,
                                 function);
         }
     } else {
         // We only use lazy source when no special encoding is specified because
         // the lazy source loader doesn't know the encoding.
         if (!reuseGlobal) {
             options.setSourceIsLazy(true);
             script.set(JS::Compile(cx, target_obj, options, buf.get(), len));
         } else {
             function.set(JS::CompileFunction(cx, target_obj, options,
                                              nullptr, 0, nullptr, buf.get(),
                                              len));
         }
     }
     /* repent for our evil deeds */
     JS_SetErrorReporter(cx, er);
     return NS_OK;
 }
 NS_IMETHODIMP
 mozJSSubScriptLoader::LoadSubScript(const nsAString &url,
                                     HandleValue target,
                                     const nsAString &charset,
                                     JSContext *cx,
                                     MutableHandleValue retval)
 {
     /*
      * Loads a local url and evals it into the current cx
      * Synchronous (an async version would be cool too.)
      *   url: The url to load.  Must be local so that it can be loaded
      *        synchronously.
      *   target_obj: Optional object to eval the script onto (defaults to context
      *               global)
      *   charset: Optional character set to use for reading
      *   returns: Whatever jsval the script pointed to by the url returns.
      * Should ONLY (O N L Y !) be called from JavaScript code.
      */
     LoadSubScriptOptions options(cx);
     options.charset = charset;
     options.target = target.isObject() ? &target.toObject() : nullptr;
     return DoLoadSubScriptWithOptions(url, options, cx, retval);
 }
 NS_IMETHODIMP
 mozJSSubScriptLoader::LoadSubScriptWithOptions(const nsAString &url,
                                                HandleValue optionsVal,
                                                JSContext *cx,
                                                MutableHandleValue retval)
 {
     if (!optionsVal.isObject())
         return NS_ERROR_INVALID_ARG;
     LoadSubScriptOptions options(cx, &optionsVal.toObject());
     if (!options.Parse())
         return NS_ERROR_INVALID_ARG;
     return DoLoadSubScriptWithOptions(url, options, cx, retval);
 }
 nsresult
 mozJSSubScriptLoader::DoLoadSubScriptWithOptions(const nsAString &url,
                                                  LoadSubScriptOptions &options,
                                                  JSContext *cx,
                                                  MutableHandleValue retval)
 {
     nsresult rv = NS_OK;
     /* set the system principal if it's not here already */
     if (!mSystemPrincipal) {
         nsCOMPtr<nsIScriptSecurityManager> secman =
             do_GetService(NS_SCRIPTSECURITYMANAGER_CONTRACTID);
         if (!secman)
             return NS_OK;
         rv = secman->GetSystemPrincipal(getter_AddRefs(mSystemPrincipal));
         if (NS_FAILED(rv) || !mSystemPrincipal)
             return rv;
     }
     RootedObject targetObj(cx);
     mozJSComponentLoader *loader = mozJSComponentLoader::Get();
     rv = loader->FindTargetObject(cx, &targetObj);
     NS_ENSURE_SUCCESS(rv, rv);
     // We base reusingGlobal off of what the loader told us, but we may not
     // actually be using that object.
     bool reusingGlobal = !JS_IsGlobalObject(targetObj);
     if (options.target)
         targetObj = options.target;
     // Remember an object out of the calling compartment so that we
     // can properly wrap the result later.
     nsCOMPtr<nsIPrincipal> principal = mSystemPrincipal;
     RootedObject result_obj(cx, targetObj);
     targetObj = JS_FindCompilationScope(cx, targetObj);
     if (!targetObj)
         return NS_ERROR_FAILURE;
     if (targetObj != result_obj)
         principal = GetObjectPrincipal(targetObj);
     JSAutoCompartment ac(cx, targetObj);
     /* load up the url.  From here on, failures are reflected as ``custom''
      * js exceptions */
     nsCOMPtr<nsIURI> uri;
     nsAutoCString uriStr;
     nsAutoCString scheme;
     // Figure out who's calling us
     JS::AutoFilename filename;
     if (!JS::DescribeScriptedCaller(cx, &filename)) {
         // No scripted frame means we don't know who's calling, bail.
         return NS_ERROR_FAILURE;
     }
     // Suppress caching if we're compiling as content.
     StartupCache* cache = (principal == mSystemPrincipal)
                           ? StartupCache::GetSingleton()
                           : nullptr;
     nsCOMPtr<nsIIOService> serv = do_GetService(NS_IOSERVICE_CONTRACTID);
     if (!serv) {
         return ReportError(cx, LOAD_ERROR_NOSERVICE);
     }
     // Make sure to explicitly create the URI, since we'll need the
     // canonicalized spec.
     rv = NS_NewURI(getter_AddRefs(uri), NS_LossyConvertUTF16toASCII(url).get(), nullptr, serv);
     if (NS_FAILED(rv)) {
         return ReportError(cx, LOAD_ERROR_NOURI);
     }
     rv = uri->GetSpec(uriStr);
     if (NS_FAILED(rv)) {
         return ReportError(cx, LOAD_ERROR_NOSPEC);
     }
     rv = uri->GetScheme(scheme);
     if (NS_FAILED(rv)) {
         return ReportError(cx, LOAD_ERROR_NOSCHEME);
     }
     if (!scheme.EqualsLiteral("chrome")) {
         // This might be a URI to a local file, though!
         nsCOMPtr<nsIURI> innerURI = NS_GetInnermostURI(uri);
         nsCOMPtr<nsIFileURL> fileURL = do_QueryInterface(innerURI);
         if (!fileURL) {
             return ReportError(cx, LOAD_ERROR_URI_NOT_LOCAL);
         }
         // For file URIs prepend the filename with the filename of the
         // calling script, and " -> ". See bug 418356.
         nsAutoCString tmp(filename.get());
         tmp.AppendLiteral(" -> ");
         tmp.Append(uriStr);
         uriStr = tmp;
     }
     bool writeScript = false;
     JSVersion version = JS_GetVersion(cx);
     nsAutoCString cachePath;
     cachePath.AppendPrintf("jssubloader/%d", version);
     PathifyURI(uri, cachePath);
     RootedFunction function(cx);
     RootedScript script(cx);
     if (cache && !options.ignoreCache)
         rv = ReadCachedScript(cache, cachePath, cx, mSystemPrincipal, &script);
     if (!script) {
         rv = ReadScript(uri, cx, targetObj, options.charset,
                         static_cast<const char*>(uriStr.get()), serv,
                         principal, reusingGlobal, &script, &function);
         writeScript = !!script;
     }
     if (NS_FAILED(rv) || (!script && !function))
         return rv;
     if (function) {
         script = JS_GetFunctionScript(cx, function);
     }
     loader->NoteSubScript(script, targetObj);
     bool ok = false;
     if (function) {
         ok = JS_CallFunction(cx, targetObj, function, JS::HandleValueArray::empty(),
                              retval);
     } else {
         ok = JS_ExecuteScriptVersion(cx, targetObj, script, retval, version);
     }
     if (ok) {
         JSAutoCompartment rac(cx, result_obj);
         if (!JS_WrapValue(cx, retval))
             return NS_ERROR_UNEXPECTED;
     }
     if (cache && ok && writeScript) {
         WriteCachedScript(cache, cachePath, cx, mSystemPrincipal, script);
     }
     return NS_OK;
 }
 /**
   * Let us compile scripts from a URI off the main thread.
   */
 class ScriptPrecompiler : public nsIStreamLoaderObserver
 {
 public:
     NS_DECL_ISUPPORTS
     NS_DECL_NSISTREAMLOADEROBSERVER
     ScriptPrecompiler(nsIObserver* aObserver,
                       nsIPrincipal* aPrincipal,
                       nsIChannel* aChannel)
         : mObserver(aObserver)
         , mPrincipal(aPrincipal)
         , mChannel(aChannel)
         , mScriptBuf(nullptr)
         , mScriptLength(0)
     {}
     virtual ~ScriptPrecompiler()
     {
       if (mScriptBuf) {
         js_free(mScriptBuf);
       }
     }
     static void OffThreadCallback(void *aToken, void *aData);
     /* Sends the "done" notification back. Main thread only. */
     void SendObserverNotification();
 private:
     nsRefPtr<nsIObserver> mObserver;
     nsRefPtr<nsIPrincipal> mPrincipal;
     nsRefPtr<nsIChannel> mChannel;
     jschar* mScriptBuf;
     size_t mScriptLength;
 };
 NS_IMPL_ISUPPORTS(ScriptPrecompiler, nsIStreamLoaderObserver);
 class NotifyPrecompilationCompleteRunnable : public nsRunnable
 {
 public:
     NS_DECL_NSIRUNNABLE
     NotifyPrecompilationCompleteRunnable(ScriptPrecompiler* aPrecompiler)
         : mPrecompiler(aPrecompiler)
         , mToken(nullptr)
     {}
     void SetToken(void* aToken) {
         MOZ_ASSERT(aToken && !mToken);
         mToken = aToken;
     }
 protected:
     nsRefPtr<ScriptPrecompiler> mPrecompiler;
     void* mToken;
 };
 /* RAII helper class to send observer notifications */
 class AutoSendObserverNotification {
 public:
     AutoSendObserverNotification(ScriptPrecompiler* aPrecompiler)
         : mPrecompiler(aPrecompiler)
     {}
     ~AutoSendObserverNotification() {
         if (mPrecompiler) {
             mPrecompiler->SendObserverNotification();
         }
     }
     void Disarm() {
         mPrecompiler = nullptr;
     }
 private:
     ScriptPrecompiler* mPrecompiler;
 };
 NS_IMETHODIMP
 NotifyPrecompilationCompleteRunnable::Run(void)
 {
     MOZ_ASSERT(NS_IsMainThread());
     MOZ_ASSERT(mPrecompiler);
     AutoSendObserverNotification notifier(mPrecompiler);
     if (mToken) {
         JSRuntime *rt = XPCJSRuntime::Get()->Runtime();
         NS_ENSURE_TRUE(rt, NS_ERROR_FAILURE);
         JS::FinishOffThreadScript(nullptr, rt, mToken);
     }
     return NS_OK;
 }
 NS_IMETHODIMP
 ScriptPrecompiler::OnStreamComplete(nsIStreamLoader* aLoader,
                                     nsISupports* aContext,
                                     nsresult aStatus,
                                     uint32_t aLength,
                                     const uint8_t* aString)
 {
     AutoSendObserverNotification notifier(this);
     // Just notify that we are done with this load.
     NS_ENSURE_SUCCESS(aStatus, NS_OK);
     // Convert data to jschar* and prepare to call CompileOffThread.
     nsAutoString hintCharset;
     nsresult rv =
         nsScriptLoader::ConvertToUTF16(mChannel, aString, aLength,
                                        hintCharset, nullptr,
                                        mScriptBuf, mScriptLength);
     NS_ENSURE_SUCCESS(rv, NS_OK);
     // Our goal is to cache persistently the compiled script and to avoid quota
     // checks. Since the caching mechanism decide the persistence type based on
     // the principal, we create a new global with the app's principal.
     // We then enter its compartment to compile with its principal.
     AutoSafeJSContext cx;
     RootedValue v(cx);
     SandboxOptions sandboxOptions;
     sandboxOptions.sandboxName.AssignASCII("asm.js precompilation");
     sandboxOptions.invisibleToDebugger = true;
     sandboxOptions.discardSource = true;
     rv = CreateSandboxObject(cx, &v, mPrincipal, sandboxOptions);
     NS_ENSURE_SUCCESS(rv, NS_OK);
     JSAutoCompartment ac(cx, js::UncheckedUnwrap(&v.toObject()));
     JS::CompileOptions options(cx, JSVERSION_DEFAULT);
     options.forceAsync = true;
     options.compileAndGo = true;
     options.installedFile = true;
     nsCOMPtr<nsIURI> uri;
     mChannel->GetURI(getter_AddRefs(uri));
     nsAutoCString spec;
     uri->GetSpec(spec);
     options.setFile(spec.get());
     if (!JS::CanCompileOffThread(cx, options, mScriptLength)) {
         NS_WARNING("Can't compile script off thread!");
         return NS_OK;
     }
     nsRefPtr<NotifyPrecompilationCompleteRunnable> runnable =
         new NotifyPrecompilationCompleteRunnable(this);
     if (!JS::CompileOffThread(cx, options,
                               mScriptBuf, mScriptLength,
                               OffThreadCallback,
                               static_cast<void*>(runnable))) {
         NS_WARNING("Failed to compile script off thread!");
         return NS_OK;
     }
     unused << runnable.forget();
     notifier.Disarm();
     return NS_OK;
 }
 /* static */
 void
 ScriptPrecompiler::OffThreadCallback(void* aToken, void* aData)
 {
     nsRefPtr<NotifyPrecompilationCompleteRunnable> runnable =
         dont_AddRef(static_cast<NotifyPrecompilationCompleteRunnable*>(aData));
     runnable->SetToken(aToken);
     NS_DispatchToMainThread(runnable);
 }
 void
 ScriptPrecompiler::SendObserverNotification()
 {
     MOZ_ASSERT(mChannel && mObserver);
     MOZ_ASSERT(NS_IsMainThread());
     nsCOMPtr<nsIURI> uri;
     mChannel->GetURI(getter_AddRefs(uri));
     mObserver->Observe(uri, "script-precompiled", nullptr);
 }
 NS_IMETHODIMP
 mozJSSubScriptLoader::PrecompileScript(nsIURI* aURI,
                                        nsIPrincipal* aPrincipal,
                                        nsIObserver *aObserver)
 {
     nsCOMPtr<nsIChannel> channel;
     nsresult rv = NS_NewChannel(getter_AddRefs(channel),
                                 aURI, nullptr, nullptr, nullptr,
                                 nsIRequest::LOAD_NORMAL, nullptr);
     NS_ENSURE_SUCCESS(rv, rv);
     nsRefPtr<ScriptPrecompiler> loadObserver =
         new ScriptPrecompiler(aObserver, aPrincipal, channel);
     nsCOMPtr<nsIStreamLoader> loader;
     rv = NS_NewStreamLoader(getter_AddRefs(loader), loadObserver);
     NS_ENSURE_SUCCESS(rv, rv);
     nsCOMPtr<nsIStreamListener> listener = loader.get();
     rv = channel->AsyncOpen(listener, nullptr);
     NS_ENSURE_SUCCESS(rv, rv);
     return NS_OK;
 }

The Tor Browser / annotate

js/xpconnect/loader/mozJSSubScriptLoader.cpp@b8a032363ba2 (annotated)

js/xpconnect/loader/mozJSSubScriptLoader.cpp