The Tor Browser: ipc/testshell/XPCShellEnvironment.cpp@97036ab72558 (annotated)

ipc/testshell/XPCShellEnvironment.cpp@97036ab72558 (annotated)

ipc/testshell/XPCShellEnvironment.cpp

Tue, 06 Jan 2015 21:39:09 +0100

author: Michael Schloh von Bennewitz <michael@schloh.com>
date: Tue, 06 Jan 2015 21:39:09 +0100
branch: TOR_BUG_9701
changeset 8: 97036ab72558
permissions: -rw-r--r--

Conditionally force memory storage according to privacy.thirdparty.isolate;
This solves Tor bug #9701, complying with disk avoidance documented in
https://www.torproject.org/projects/torbrowser/design/#disk-avoidance.

 /* vim: set ts=8 sts=4 et sw=4 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 <stdlib.h>
 #include <errno.h>
 #ifdef HAVE_IO_H
 #include <io.h>     /* for isatty() */
 #endif
 #ifdef HAVE_UNISTD_H
 #include <unistd.h>     /* for isatty() */
 #endif
 #include "base/basictypes.h"
 #include "jsapi.h"
 #include "js/OldDebugAPI.h"
 #include "xpcpublic.h"
 #include "XPCShellEnvironment.h"
 #include "mozilla/XPCOM.h"
 #include "nsIChannel.h"
 #include "nsIClassInfo.h"
 #include "nsIDirectoryService.h"
 #include "nsIJSRuntimeService.h"
 #include "nsIPrincipal.h"
 #include "nsIScriptSecurityManager.h"
 #include "nsIURI.h"
 #include "nsIXPConnect.h"
 #include "nsIXPCScriptable.h"
 #include "nsCxPusher.h"
 #include "nsJSUtils.h"
 #include "nsJSPrincipals.h"
 #include "nsThreadUtils.h"
 #include "nsXULAppAPI.h"
 #include "BackstagePass.h"
 #include "TestShellChild.h"
 #include "TestShellParent.h"
 using mozilla::ipc::XPCShellEnvironment;
 using mozilla::ipc::TestShellChild;
 using mozilla::ipc::TestShellParent;
 using mozilla::AutoSafeJSContext;
 using namespace JS;
 namespace {
 static const char kDefaultRuntimeScriptFilename[] = "xpcshell.js";
 class XPCShellDirProvider : public nsIDirectoryServiceProvider
 {
 public:
     NS_DECL_ISUPPORTS
     NS_DECL_NSIDIRECTORYSERVICEPROVIDER
     XPCShellDirProvider() { }
     ~XPCShellDirProvider() { }
     bool SetGREDir(const char *dir);
     void ClearGREDir() { mGREDir = nullptr; }
 private:
     nsCOMPtr<nsIFile> mGREDir;
 };
 inline XPCShellEnvironment*
 Environment(Handle<JSObject*> global)
 {
     AutoSafeJSContext cx;
     JSAutoCompartment ac(cx, global);
     Rooted<Value> v(cx);
     if (!JS_GetProperty(cx, global, "__XPCShellEnvironment", &v) ||
         !v.get().isDouble())
     {
         return nullptr;
     }
     return static_cast<XPCShellEnvironment*>(v.get().toPrivate());
 }
 static bool
 Print(JSContext *cx, unsigned argc, JS::Value *vp)
 {
     JS::CallArgs args = JS::CallArgsFromVp(argc, vp);
     for (unsigned i = 0; i < args.length(); i++) {
         JSString *str = JS::ToString(cx, args[i]);
         if (!str)
             return false;
         JSAutoByteString bytes(cx, str);
         if (!bytes)
             return false;
         fprintf(stdout, "%s%s", i ? " " : "", bytes.ptr());
         fflush(stdout);
     }
     fputc('\n', stdout);
     args.rval().setUndefined();
     return true;
 }
 static bool
 GetLine(char *bufp,
         FILE *file,
         const char *prompt)
 {
     char line[256];
     fputs(prompt, stdout);
     fflush(stdout);
     if (!fgets(line, sizeof line, file))
         return false;
     strcpy(bufp, line);
     return true;
 }
 static bool
 Dump(JSContext *cx, unsigned argc, JS::Value *vp)
 {
     JS::CallArgs args = JS::CallArgsFromVp(argc, vp);
     if (!args.length())
         return true;
     JSString *str = JS::ToString(cx, args[0]);
     if (!str)
         return false;
     JSAutoByteString bytes(cx, str);
     if (!bytes)
       return false;
     fputs(bytes.ptr(), stdout);
     fflush(stdout);
     return true;
 }
 static bool
 Load(JSContext *cx,
      unsigned argc,
      JS::Value *vp)
 {
     JS::CallArgs args = JS::CallArgsFromVp(argc, vp);
     JS::Rooted<JSObject*> obj(cx, JS_THIS_OBJECT(cx, vp));
     if (!obj)
         return false;
     for (unsigned i = 0; i < args.length(); i++) {
         JS::Rooted<JSString*> str(cx, JS::ToString(cx, args[i]));
         if (!str)
             return false;
         JSAutoByteString filename(cx, str);
         if (!filename)
             return false;
         FILE *file = fopen(filename.ptr(), "r");
         if (!file) {
             JS_ReportError(cx, "cannot open file '%s' for reading", filename.ptr());
             return false;
         }
         Rooted<JSObject*> global(cx, JS::CurrentGlobalOrNull(cx));
         JS::CompileOptions options(cx);
         options.setUTF8(true)
                .setFileAndLine(filename.ptr(), 1);
         JS::Rooted<JSScript*> script(cx, JS::Compile(cx, obj, options, file));
         fclose(file);
         if (!script)
             return false;
         if (!JS_ExecuteScript(cx, obj, script)) {
             return false;
         }
     }
     args.rval().setUndefined();
     return true;
 }
 static bool
 Version(JSContext *cx,
         unsigned argc,
         JS::Value *vp)
 {
     JS::CallArgs args = JS::CallArgsFromVp(argc, vp);
     args.rval().setInt32(JS_GetVersion(cx));
     if (args.get(0).isInt32())
         JS_SetVersionForCompartment(js::GetContextCompartment(cx),
                                     JSVersion(args[0].toInt32()));
     return true;
 }
 static bool
 BuildDate(JSContext *cx, unsigned argc, JS::Value *vp)
 {
     JS::CallArgs args = JS::CallArgsFromVp(argc, vp);
     fprintf(stdout, "built on %s at %s\n", __DATE__, __TIME__);
     args.rval().setUndefined();
     return true;
 }
 static bool
 Quit(JSContext *cx,
      unsigned argc,
      JS::Value *vp)
 {
     Rooted<JSObject*> global(cx, JS::CurrentGlobalOrNull(cx));
     XPCShellEnvironment* env = Environment(global);
     env->SetIsQuitting();
     return false;
 }
 static bool
 DumpXPC(JSContext *cx,
         unsigned argc,
         JS::Value *vp)
 {
     JS::CallArgs args = CallArgsFromVp(argc, vp);
     uint16_t depth = 2;
     if (args.length() > 0) {
         if (!JS::ToUint16(cx, args[0], &depth))
             return false;
     }
     nsCOMPtr<nsIXPConnect> xpc = do_GetService(nsIXPConnect::GetCID());
     if (xpc)
         xpc->DebugDump(int16_t(depth));
     args.rval().setUndefined();
     return true;
 }
 static bool
 GC(JSContext *cx,
    unsigned argc,
    JS::Value *vp)
 {
     JS::CallArgs args = JS::CallArgsFromVp(argc, vp);
     JSRuntime *rt = JS_GetRuntime(cx);
     JS_GC(rt);
 #ifdef JS_GCMETER
     js_DumpGCStats(rt, stdout);
 #endif
     args.rval().setUndefined();
     return true;
 }
 #ifdef JS_GC_ZEAL
 static bool
 GCZeal(JSContext *cx, unsigned argc, JS::Value *vp)
 {
   CallArgs args = CallArgsFromVp(argc, vp);
   uint32_t zeal;
   if (!ToUint32(cx, args.get(0), &zeal))
     return false;
   JS_SetGCZeal(cx, uint8_t(zeal), JS_DEFAULT_ZEAL_FREQ);
   return true;
 }
 #endif
 const JSFunctionSpec gGlobalFunctions[] =
 {
     JS_FS("print",           Print,          0,0),
     JS_FS("load",            Load,           1,0),
     JS_FS("quit",            Quit,           0,0),
     JS_FS("version",         Version,        1,0),
     JS_FS("build",           BuildDate,      0,0),
     JS_FS("dumpXPC",         DumpXPC,        1,0),
     JS_FS("dump",            Dump,           1,0),
     JS_FS("gc",              GC,             0,0),
  #ifdef JS_GC_ZEAL
     JS_FS("gczeal",          GCZeal,         1,0),
  #endif
     JS_FS_END
 };
 typedef enum JSShellErrNum
 {
 #define MSG_DEF(name, number, count, exception, format) \
     name = number,
 #include "jsshell.msg"
 #undef MSG_DEF
     JSShellErr_Limit
 #undef MSGDEF
 } JSShellErrNum;
 } /* anonymous namespace */
 void
 XPCShellEnvironment::ProcessFile(JSContext *cx,
                                  JS::Handle<JSObject*> obj,
                                  const char *filename,
                                  FILE *file,
                                  bool forceTTY)
 {
     XPCShellEnvironment* env = this;
     JS::Rooted<JS::Value> result(cx);
     int lineno, startline;
     bool ok, hitEOF;
     char *bufp, buffer[4096];
     JSString *str;
     if (forceTTY) {
         file = stdin;
     }
     else if (!isatty(fileno(file)))
     {
         /*
          * It's not interactive - just execute it.
          *
          * Support the UNIX #! shell hack; gobble the first line if it starts
          * with '#'.  TODO - this isn't quite compatible with sharp variables,
          * as a legal js program (using sharp variables) might start with '#'.
          * But that would require multi-character lookahead.
          */
         int ch = fgetc(file);
         if (ch == '#') {
             while((ch = fgetc(file)) != EOF) {
                 if(ch == '\n' || ch == '\r')
                     break;
             }
         }
         ungetc(ch, file);
         JSAutoRequest ar(cx);
         JSAutoCompartment ac(cx, obj);
         JS::CompileOptions options(cx);
         options.setUTF8(true)
                .setFileAndLine(filename, 1);
         JS::Rooted<JSScript*> script(cx, JS::Compile(cx, obj, options, file));
         if (script)
             (void)JS_ExecuteScript(cx, obj, script, &result);
         return;
     }
     /* It's an interactive filehandle; drop into read-eval-print loop. */
     lineno = 1;
     hitEOF = false;
     do {
         bufp = buffer;
         *bufp = '\0';
         JSAutoRequest ar(cx);
         JSAutoCompartment ac(cx, obj);
         /*
          * Accumulate lines until we get a 'compilable unit' - one that either
          * generates an error (before running out of source) or that compiles
          * cleanly.  This should be whenever we get a complete statement that
          * coincides with the end of a line.
          */
         startline = lineno;
         do {
             if (!GetLine(bufp, file, startline == lineno ? "js> " : "")) {
                 hitEOF = true;
                 break;
             }
             bufp += strlen(bufp);
             lineno++;
         } while (!JS_BufferIsCompilableUnit(cx, obj, buffer, strlen(buffer)));
         /* Clear any pending exception from previous failed compiles.  */
         JS_ClearPendingException(cx);
         JS::CompileOptions options(cx);
         options.setFileAndLine("typein", startline);
         JS::Rooted<JSScript*> script(cx,
                                      JS_CompileScript(cx, obj, buffer, strlen(buffer), options));
         if (script) {
             JSErrorReporter older;
             ok = JS_ExecuteScript(cx, obj, script, &result);
             if (ok && result != JSVAL_VOID) {
                 /* Suppress error reports from JS::ToString(). */
                 older = JS_SetErrorReporter(cx, nullptr);
                 str = JS::ToString(cx, result);
                 JSAutoByteString bytes;
                 if (str)
                     bytes.encodeLatin1(cx, str);
                 JS_SetErrorReporter(cx, older);
                 if (!!bytes)
                     fprintf(stdout, "%s\n", bytes.ptr());
                 else
                     ok = false;
             }
         }
     } while (!hitEOF && !env->IsQuitting());
     fprintf(stdout, "\n");
 }
 NS_IMETHODIMP_(MozExternalRefCountType)
 XPCShellDirProvider::AddRef()
 {
     return 2;
 }
 NS_IMETHODIMP_(MozExternalRefCountType)
 XPCShellDirProvider::Release()
 {
     return 1;
 }
 NS_IMPL_QUERY_INTERFACE(XPCShellDirProvider, nsIDirectoryServiceProvider)
 bool
 XPCShellDirProvider::SetGREDir(const char *dir)
 {
     nsresult rv = XRE_GetFileFromPath(dir, getter_AddRefs(mGREDir));
     return NS_SUCCEEDED(rv);
 }
 NS_IMETHODIMP
 XPCShellDirProvider::GetFile(const char *prop,
                              bool *persistent,
                              nsIFile* *result)
 {
     if (mGREDir && !strcmp(prop, NS_GRE_DIR)) {
         *persistent = true;
         NS_ADDREF(*result = mGREDir);
         return NS_OK;
     }
     return NS_ERROR_FAILURE;
 }
 // static
 XPCShellEnvironment*
 XPCShellEnvironment::CreateEnvironment()
 {
     XPCShellEnvironment* env = new XPCShellEnvironment();
     if (env && !env->Init()) {
         delete env;
         env = nullptr;
     }
     return env;
 }
 XPCShellEnvironment::XPCShellEnvironment()
 :   mQuitting(false)
 {
 }
 XPCShellEnvironment::~XPCShellEnvironment()
 {
     AutoSafeJSContext cx;
     Rooted<JSObject*> global(cx, GetGlobalObject());
     if (global) {
         {
             JSAutoCompartment ac(cx, global);
             JS_SetAllNonReservedSlotsToUndefined(cx, global);
         }
         mGlobalHolder.Release();
         JSRuntime *rt = JS_GetRuntime(cx);
         JS_GC(rt);
     }
 }
 bool
 XPCShellEnvironment::Init()
 {
     nsresult rv;
     // unbuffer stdout so that output is in the correct order; note that stderr
     // is unbuffered by default
     setbuf(stdout, 0);
     nsCOMPtr<nsIJSRuntimeService> rtsvc =
         do_GetService("@mozilla.org/js/xpc/RuntimeService;1");
     if (!rtsvc) {
         NS_ERROR("failed to get nsJSRuntimeService!");
         return false;
     }
     JSRuntime *rt;
     if (NS_FAILED(rtsvc->GetRuntime(&rt)) || !rt) {
         NS_ERROR("failed to get JSRuntime from nsJSRuntimeService!");
         return false;
     }
     if (!mGlobalHolder.Hold(rt)) {
         NS_ERROR("Can't protect global object!");
         return false;
     }
     AutoSafeJSContext cx;
     JS_SetContextPrivate(cx, this);
     nsCOMPtr<nsIXPConnect> xpc =
       do_GetService(nsIXPConnect::GetCID());
     if (!xpc) {
         NS_ERROR("failed to get nsXPConnect service!");
         return false;
     }
     nsCOMPtr<nsIPrincipal> principal;
     nsCOMPtr<nsIScriptSecurityManager> securityManager =
         do_GetService(NS_SCRIPTSECURITYMANAGER_CONTRACTID, &rv);
     if (NS_SUCCEEDED(rv) && securityManager) {
         rv = securityManager->GetSystemPrincipal(getter_AddRefs(principal));
         if (NS_FAILED(rv)) {
             fprintf(stderr, "+++ Failed to obtain SystemPrincipal from ScriptSecurityManager service.\n");
         }
     } else {
         fprintf(stderr, "+++ Failed to get ScriptSecurityManager service, running without principals");
     }
     nsRefPtr<BackstagePass> backstagePass;
     rv = NS_NewBackstagePass(getter_AddRefs(backstagePass));
     if (NS_FAILED(rv)) {
         NS_ERROR("Failed to create backstage pass!");
         return false;
     }
     JS::CompartmentOptions options;
     options.setZone(JS::SystemZone)
            .setVersion(JSVERSION_LATEST);
     nsCOMPtr<nsIXPConnectJSObjectHolder> holder;
     rv = xpc->InitClassesWithNewWrappedGlobal(cx,
                                               static_cast<nsIGlobalObject *>(backstagePass),
                                               principal, 0,
                                               options,
                                               getter_AddRefs(holder));
     if (NS_FAILED(rv)) {
         NS_ERROR("InitClassesWithNewWrappedGlobal failed!");
         return false;
     }
     JS::Rooted<JSObject*> globalObj(cx, holder->GetJSObject());
     if (!globalObj) {
         NS_ERROR("Failed to get global JSObject!");
         return false;
     }
     JSAutoCompartment ac(cx, globalObj);
     backstagePass->SetGlobalObject(globalObj);
     JS::Rooted<Value> privateVal(cx, PrivateValue(this));
     if (!JS_DefineProperty(cx, globalObj, "__XPCShellEnvironment",
                            privateVal, JSPROP_READONLY | JSPROP_PERMANENT,
                            JS_PropertyStub, JS_StrictPropertyStub) ||
         !JS_DefineFunctions(cx, globalObj, gGlobalFunctions) ||
         !JS_DefineProfilingFunctions(cx, globalObj))
     {
         NS_ERROR("JS_DefineFunctions failed!");
         return false;
     }
     mGlobalHolder = globalObj;
     FILE* runtimeScriptFile = fopen(kDefaultRuntimeScriptFilename, "r");
     if (runtimeScriptFile) {
         fprintf(stdout, "[loading '%s'...]\n", kDefaultRuntimeScriptFilename);
         ProcessFile(cx, globalObj, kDefaultRuntimeScriptFilename,
                     runtimeScriptFile, false);
         fclose(runtimeScriptFile);
     }
     return true;
 }
 bool
 XPCShellEnvironment::EvaluateString(const nsString& aString,
                                     nsString* aResult)
 {
   AutoSafeJSContext cx;
   JS::Rooted<JSObject*> global(cx, GetGlobalObject());
   JSAutoCompartment ac(cx, global);
   JS::CompileOptions options(cx);
   options.setFileAndLine("typein", 0);
   JS::Rooted<JSScript*> script(cx, JS_CompileUCScript(cx, global, aString.get(),
                                                       aString.Length(), options));
   if (!script) {
      return false;
   }
   if (aResult) {
       aResult->Truncate();
   }
   JS::Rooted<JS::Value> result(cx);
   bool ok = JS_ExecuteScript(cx, global, script, &result);
   if (ok && result != JSVAL_VOID) {
       JSErrorReporter old = JS_SetErrorReporter(cx, nullptr);
       JSString* str = JS::ToString(cx, result);
       nsDependentJSString depStr;
       if (str)
           depStr.init(cx, str);
       JS_SetErrorReporter(cx, old);
       if (!depStr.IsEmpty() && aResult) {
           aResult->Assign(depStr);
       }
   }
   return true;
 }

The Tor Browser / annotate

ipc/testshell/XPCShellEnvironment.cpp@97036ab72558 (annotated)

ipc/testshell/XPCShellEnvironment.cpp