コード例 #1
0
int NaClSelLdrMain(int argc, char **argv) {
  int                           opt;
  char                          *rest;
  struct redir                  *entry;
  struct redir                  *redir_queue;
  struct redir                  **redir_qend;


  struct NaClApp                state;
  char                          *nacl_file = NULL;
  char                          *blob_library_file = NULL;
  int                           rpc_supplies_nexe = 0;
  int                           export_addr_to = -1;

  struct NaClApp                *nap = &state;

  struct GioFile                gout;
  NaClErrorCode                 errcode = LOAD_INTERNAL;
  struct GioMemoryFileSnapshot  blob_file;

  int                           ret_code;
  struct DynArray               env_vars;

  char                          *log_file = NULL;
  int                           verbosity = 0;
  int                           fuzzing_quit_after_load = 0;
  int                           debug_mode_bypass_acl_checks = 0;
  int                           debug_mode_ignore_validator = 0;
  int                           skip_qualification = 0;
  int                           handle_signals = 0;
  int                           enable_debug_stub = 0;
  struct NaClPerfCounter        time_all_main;
  const char                    **envp;
  struct NaClEnvCleanser        env_cleanser;

#if NACL_OSX
  /* Mac dynamic libraries cannot access the environ variable directly. */
  envp = (const char **) *_NSGetEnviron();
#else
  /* Overzealous code style check is overzealous. */
  /* @IGNORE_LINES_FOR_CODE_HYGIENE[1] */
  extern char **environ;
  envp = (const char **) environ;
#endif

  ret_code = 1;
  redir_queue = NULL;
  redir_qend = &redir_queue;

  memset(&state, 0, sizeof state);
  NaClAllModulesInit();
  NaClBootstrapChannelErrorReporterInit();
  NaClErrorLogHookInit(NaClBootstrapChannelErrorReporter, &state);

  verbosity = NaClLogGetVerbosity();

  NaClPerfCounterCtor(&time_all_main, "SelMain");

  fflush((FILE *) NULL);

  NaClDebugExceptionHandlerStandaloneHandleArgs(argc, argv);

  if (!GioFileRefCtor(&gout, stdout)) {
    fprintf(stderr, "Could not create general standard output channel\n");
    exit(1);
  }
  if (!NaClAppCtor(&state)) {
    NaClLog(LOG_FATAL, "NaClAppCtor() failed\n");
  }
  if (!DynArrayCtor(&env_vars, 0)) {
    NaClLog(LOG_FATAL, "Failed to allocate env var array\n");
  }
  /*
   * On platforms with glibc getopt, require POSIXLY_CORRECT behavior,
   * viz, no reordering of the arglist -- stop argument processing as
   * soon as an unrecognized argument is encountered, so that, for
   * example, in the invocation
   *
   *   sel_ldr foo.nexe -vvv
   *
   * the -vvv flags are made available to the nexe, rather than being
   * consumed by getopt.  This makes the behavior of the Linux build
   * of sel_ldr consistent with the Windows and OSX builds.
   */
  while ((opt = my_getopt(argc, argv,
#if NACL_LINUX
                       "+D:z:"
#endif
                       "aB:ceE:f:Fgh:i:l:Qr:RsSvw:X:Z")) != -1) {
    switch (opt) {
      case 'a':
        fprintf(stderr, "DEBUG MODE ENABLED (bypass acl)\n");
        debug_mode_bypass_acl_checks = 1;
        break;
      case 'B':
        blob_library_file = optarg;
        break;
      case 'c':
        ++debug_mode_ignore_validator;
        break;
#if NACL_LINUX
      case 'D':
        NaClHandleRDebug(optarg, argv[0]);
        break;
#endif
      case 'e':
        nap->enable_exception_handling = 1;
        break;
      case 'E':
        /*
         * For simplicity, we treat the environment variables as a
         * list of strings rather than a key/value mapping.  We do not
         * try to prevent duplicate keys or require the strings to be
         * of the form "KEY=VALUE".  This is in line with how execve()
         * works in Unix.
         *
         * We expect that most callers passing "-E" will either pass
         * in a fixed list or will construct the list using a
         * high-level language, in which case de-duplicating keys
         * outside of sel_ldr is easier.  However, we could do
         * de-duplication here if it proves to be worthwhile.
         */
        if (!DynArraySet(&env_vars, env_vars.num_entries, optarg)) {
          NaClLog(LOG_FATAL, "Adding item to env_vars failed\n");
        }
        break;
      case 'f':
        nacl_file = optarg;
        break;
      case 'F':
        fuzzing_quit_after_load = 1;
        break;

      case 'g':
        enable_debug_stub = 1;
        break;

      case 'h':
      case 'r':
      case 'w':
        /* import host descriptor */
        entry = malloc(sizeof *entry);
        if (NULL == entry) {
          fprintf(stderr, "No memory for redirection queue\n");
          exit(1);
        }
        entry->next = NULL;
        entry->nacl_desc = strtol(optarg, &rest, 0);
        entry->tag = HOST_DESC;
        entry->u.host.d = strtol(rest+1, (char **) 0, 0);
        entry->u.host.mode = ImportModeMap(opt);
        *redir_qend = entry;
        redir_qend = &entry->next;
        break;
      case 'i':
        /* import IMC handle */
        entry = malloc(sizeof *entry);
        if (NULL == entry) {
          fprintf(stderr, "No memory for redirection queue\n");
          exit(1);
        }
        entry->next = NULL;
        entry->nacl_desc = strtol(optarg, &rest, 0);
        entry->tag = IMC_DESC;
        entry->u.handle = (NaClHandle) strtol(rest+1, (char **) 0, 0);
        *redir_qend = entry;
        redir_qend = &entry->next;
        break;
      case 'l':
        log_file = optarg;
        break;
      case 'Q':
        fprintf(stderr, "PLATFORM QUALIFICATION DISABLED BY -Q - "
                "Native Client's sandbox will be unreliable!\n");
        skip_qualification = 1;
        break;
      case 'R':
        rpc_supplies_nexe = 1;
        break;
      /* case 'r':  with 'h' and 'w' above */
      case 's':
        nap->validator_stub_out_mode = 1;
        break;
      case 'S':
        handle_signals = 1;
        break;
      case 'v':
        ++verbosity;
        NaClLogIncrVerbosity();
        break;
      /* case 'w':  with 'h' and 'r' above */
      case 'X':
        export_addr_to = strtol(optarg, (char **) 0, 0);
        break;
#if NACL_LINUX
      case 'z':
        NaClHandleReservedAtZero(optarg);
        break;
#endif
      case 'Z':
        NaClLog(LOG_WARNING, "Enabling Fixed-Feature CPU Mode\n");
        nap->fixed_feature_cpu_mode = 1;
        if (!nap->validator->FixCPUFeatures(nap->cpu_features)) {
          NaClLog(LOG_ERROR,
                  "This CPU lacks features required by "
                  "fixed-function CPU mode.\n");
          exit(1);
        }
        break;
      default:
        fprintf(stderr, "ERROR: unknown option: [%c]\n\n", opt);
        PrintUsage();
        exit(-1);
    }
  }

  if (debug_mode_ignore_validator == 1)
    fprintf(stderr, "DEBUG MODE ENABLED (ignore validator)\n");
  else if (debug_mode_ignore_validator > 1)
    fprintf(stderr, "DEBUG MODE ENABLED (skip validator)\n");

  if (verbosity) {
    int         ix;
    char const  *separator = "";

    fprintf(stderr, "sel_ldr argument list:\n");
    for (ix = 0; ix < argc; ++ix) {
      fprintf(stderr, "%s%s", separator, argv[ix]);
      separator = " ";
    }
    putc('\n', stderr);
  }

  if (debug_mode_bypass_acl_checks) {
    NaClInsecurelyBypassAllAclChecks();
  }

  /*
   * change stdout/stderr to log file now, so that subsequent error
   * messages will go there.  unfortunately, error messages that
   * result from getopt processing -- usually out-of-memory, which
   * shouldn't happen -- won't show up.
   */
  if (NULL != log_file) {
    NaClLogSetFile(log_file);
  }

  if (rpc_supplies_nexe) {
    if (NULL != nacl_file) {
      fprintf(stderr,
              "sel_ldr: mutually exclusive flags -f and -R both used\n");
      exit(1);
    }
    /* post: NULL == nacl_file */
    if (export_addr_to < 0) {
      fprintf(stderr,
              "sel_ldr: -R requires -X to set up secure command channel\n");
      exit(1);
    }
  } else {
    if (NULL == nacl_file && optind < argc) {
      nacl_file = argv[optind];
      ++optind;
    }
    if (NULL == nacl_file) {
      fprintf(stderr, "No nacl file specified\n");
      exit(1);
    }
    /* post: NULL != nacl_file */
  }
  /*
   * post condition established by the above code (in Hoare logic
   * terminology):
   *
   * NULL == nacl_file iff rpc_supplies_nexe
   *
   * so hence forth, testing !rpc_supplies_nexe suffices for
   * establishing NULL != nacl_file.
   */
  CHECK((NULL == nacl_file) == rpc_supplies_nexe);

  /* to be passed to NaClMain, eventually... */
  argv[--optind] = (char *) "NaClMain";

  state.ignore_validator_result = (debug_mode_ignore_validator > 0);
  state.skip_validator = (debug_mode_ignore_validator > 1);

  if (getenv("NACL_UNTRUSTED_EXCEPTION_HANDLING") != NULL) {
    state.enable_exception_handling = 1;
  }
  if (state.enable_exception_handling || enable_debug_stub) {
#if NACL_WINDOWS
    state.attach_debug_exception_handler_func =
        NaClDebugExceptionHandlerStandaloneAttach;
#elif NACL_LINUX
    /* NaCl's signal handler is always enabled on Linux. */
#elif NACL_OSX
    if (!NaClInterceptMachExceptions()) {
      fprintf(stderr, "ERROR setting up Mach exception interception.\n");
      return -1;
    }
#else
# error Unknown host OS
#endif
  }
  if (NACL_LINUX) {
    handle_signals = 1;
  }

  errcode = LOAD_OK;

  /*
   * in order to report load error to the browser plugin through the
   * secure command channel, we do not immediate jump to cleanup code
   * on error.  rather, we continue processing (assuming earlier
   * errors do not make it inappropriate) until the secure command
   * channel is set up, and then bail out.
   */

  /*
   * Ensure the platform qualification checks pass.
   *
   * NACL_DANGEROUS_SKIP_QUALIFICATION_TEST is used by tsan / memcheck
   * (see src/third_party/valgrind/).
   */
  if (!skip_qualification &&
      getenv("NACL_DANGEROUS_SKIP_QUALIFICATION_TEST") != NULL) {
    fprintf(stderr, "PLATFORM QUALIFICATION DISABLED BY ENVIRONMENT - "
            "Native Client's sandbox will be unreliable!\n");
    skip_qualification = 1;
  }

  if (!skip_qualification) {
    NaClErrorCode pq_error = NACL_FI_VAL("pq", NaClErrorCode,
                                         NaClRunSelQualificationTests());
    if (LOAD_OK != pq_error) {
      errcode = pq_error;
      nap->module_load_status = pq_error;
      fprintf(stderr, "Error while loading \"%s\": %s\n",
              NULL != nacl_file ? nacl_file
                                : "(no file, to-be-supplied-via-RPC)",
              NaClErrorString(errcode));
    }
  }

  if (handle_signals) {
    NaClSignalHandlerInit();
  } else {
    /*
     * Patch the Windows exception dispatcher to be safe in the case
     * of faults inside x86-64 sandboxed code.  The sandbox is not
     * secure on 64-bit Windows without this.
     */
#if (NACL_WINDOWS && NACL_ARCH(NACL_BUILD_ARCH) == NACL_x86 && \
     NACL_BUILD_SUBARCH == 64)
    NaClPatchWindowsExceptionDispatcher();
#endif
  }
  NaClSignalTestCrashOnStartup();

  /*
   * Open both files first because (on Mac OS X at least)
   * NaClAppLoadFile() enables an outer sandbox.
   */
  if (NULL != blob_library_file) {
    NaClFileNameForValgrind(blob_library_file);
    if (0 == GioMemoryFileSnapshotCtor(&blob_file, blob_library_file)) {
      perror("sel_main");
      fprintf(stderr, "Cannot open \"%s\".\n", blob_library_file);
      exit(1);
    }
    NaClPerfCounterMark(&time_all_main, "SnapshotBlob");
    NaClPerfCounterIntervalLast(&time_all_main);
  }

  NaClAppInitialDescriptorHookup(nap);

  if (!rpc_supplies_nexe) {
    struct GioMemoryFileSnapshot main_file;

    NaClFileNameForValgrind(nacl_file);
    if (0 == GioMemoryFileSnapshotCtor(&main_file, nacl_file)) {
      perror("sel_main");
      fprintf(stderr, "Cannot open \"%s\".\n", nacl_file);
      exit(1);
    }
    NaClPerfCounterMark(&time_all_main, "SnapshotNaclFile");
    NaClPerfCounterIntervalLast(&time_all_main);

    if (LOAD_OK == errcode) {
      NaClLog(2, "Loading nacl file %s (non-RPC)\n", nacl_file);
      errcode = NaClAppLoadFile((struct Gio *) &main_file, nap);
      if (LOAD_OK != errcode) {
        fprintf(stderr, "Error while loading \"%s\": %s\n",
                nacl_file,
                NaClErrorString(errcode));
        fprintf(stderr,
                ("Using the wrong type of nexe (nacl-x86-32"
                 " on an x86-64 or vice versa)\n"
                 "or a corrupt nexe file may be"
                 " responsible for this error.\n"));
      }
      NaClPerfCounterMark(&time_all_main, "AppLoadEnd");
      NaClPerfCounterIntervalLast(&time_all_main);

      NaClXMutexLock(&nap->mu);
      nap->module_load_status = errcode;
      NaClXCondVarBroadcast(&nap->cv);
      NaClXMutexUnlock(&nap->mu);
    }

    if (-1 == (*((struct Gio *) &main_file)->vtbl->Close)((struct Gio *)
                                                          &main_file)) {
      fprintf(stderr, "Error while closing \"%s\".\n", nacl_file);
    }
    (*((struct Gio *) &main_file)->vtbl->Dtor)((struct Gio *) &main_file);

    if (fuzzing_quit_after_load) {
      exit(0);
    }
  }

  /*
   * Execute additional I/O redirections.  NB: since the NaClApp
   * takes ownership of host / IMC socket descriptors, all but
   * the first run will not get access if the NaClApp closes
   * them.  Currently a normal NaClApp process exit does not
   * close descriptors, since the underlying host OS will do so
   * as part of service runtime exit.
   */
  NaClLog(4, "Processing I/O redirection/inheritance from command line\n");
  for (entry = redir_queue; NULL != entry; entry = entry->next) {
    switch (entry->tag) {
      case HOST_DESC:
        NaClAddHostDescriptor(nap, entry->u.host.d,
                              entry->u.host.mode, entry->nacl_desc);
        break;
      case IMC_DESC:
        NaClAddImcHandle(nap, entry->u.handle, entry->nacl_desc);
        break;
    }
  }

  /*
   * If export_addr_to is set to a non-negative integer, we create a
   * bound socket and socket address pair and bind the former to
   * descriptor NACL_SERVICE_PORT_DESCRIPTOR (3 [see sel_ldr.h]) and
   * the latter to descriptor NACL_SERVICE_ADDRESS_DESCRIPTOR (4).
   * The socket address is sent to the export_addr_to descriptor.
   *
   * The service runtime also accepts a connection on the bound socket
   * and spawns a secure command channel thread to service it.
   */
  if (0 <= export_addr_to) {
    NaClCreateServiceSocket(nap);
    /*
     * LOG_FATAL errors that occur before NaClSetUpBootstrapChannel will
     * not be reported via the crash log mechanism (for Chromium
     * embedding of NaCl, shown in the JavaScript console).
     *
     * Some errors, such as due to NaClRunSelQualificationTests, do not
     * trigger a LOG_FATAL but instead set module_load_status to be sent
     * in the start_module RPC reply.  Log messages associated with such
     * errors would be seen, since NaClSetUpBootstrapChannel will get
     * called.
     */
    NaClSetUpBootstrapChannel(nap, (NaClHandle) export_addr_to);
    /*
     * NB: spawns a thread that uses the command channel.  we do
     * this after NaClAppLoadFile so that NaClApp object is more
     * fully populated.  Hereafter any changes to nap should be done
     * while holding locks.
     */
    NaClSecureCommandChannel(nap);
  }

  /*
   * May have created a thread, so need to synchronize uses of nap
   * contents henceforth.
   */

  if (rpc_supplies_nexe) {
    errcode = NaClWaitForLoadModuleStatus(nap);
    NaClPerfCounterMark(&time_all_main, "WaitForLoad");
    NaClPerfCounterIntervalLast(&time_all_main);
  } else {
    /**************************************************************************
     * TODO(bsy): This else block should be made unconditional and
     * invoked after the LoadModule RPC completes, eliminating the
     * essentially dulicated code in latter part of NaClLoadModuleRpc.
     * This cannot be done until we have full saucer separation
     * technology, since Chrome currently uses sel_main_chrome.c and
     * relies on the functionality of the duplicated code.
     *************************************************************************/
    if (LOAD_OK == errcode) {
      if (verbosity) {
        gprintf((struct Gio *) &gout, "printing NaClApp details\n");
        NaClAppPrintDetails(nap, (struct Gio *) &gout);
      }

      /*
       * Finish setting up the NaCl App.  On x86-32, this means
       * allocating segment selectors.  On x86-64 and ARM, this is
       * (currently) a no-op.
       */
      errcode = NaClAppPrepareToLaunch(nap);
      if (LOAD_OK != errcode) {
        nap->module_load_status = errcode;
        fprintf(stderr, "NaClAppPrepareToLaunch returned %d", errcode);
      }
      NaClPerfCounterMark(&time_all_main, "AppPrepLaunch");
      NaClPerfCounterIntervalLast(&time_all_main);
    }

    /* Give debuggers a well known point at which xlate_base is known.  */
    NaClGdbHook(&state);
  }

  /*
   * Tell the debug stub to bind a TCP port before enabling the outer
   * sandbox.  This is only needed on Mac OS X since that is the only
   * platform where we have an outer sandbox in standalone sel_ldr.
   * In principle this call should work on all platforms, but Windows
   * XP seems to have some problems when we do bind()/listen() on a
   * separate thread from accept().
   */
  if (enable_debug_stub && NACL_OSX) {
    if (!NaClDebugBindSocket()) {
      exit(1);
    }
  }

  /*
   * Enable the outer sandbox, if one is defined.  Do this as soon as
   * possible.
   *
   * This must come after NaClWaitForLoadModuleStatus(), which waits
   * for another thread to have called NaClAppLoadFile().
   * NaClAppLoadFile() does not work inside the Mac outer sandbox in
   * standalone sel_ldr when using a dynamic code area because it uses
   * NaClCreateMemoryObject() which opens a file in /tmp.
   *
   * We cannot enable the sandbox if file access is enabled.
   */
  if (!NaClAclBypassChecks && g_enable_outer_sandbox_func != NULL) {
    g_enable_outer_sandbox_func();
  }

  if (NULL != blob_library_file) {
    if (LOAD_OK == errcode) {
      NaClLog(2, "Loading blob file %s\n", blob_library_file);
      errcode = NaClAppLoadFileDynamically(nap, (struct Gio *) &blob_file);
      if (LOAD_OK != errcode) {
        fprintf(stderr, "Error while loading \"%s\": %s\n",
                blob_library_file,
                NaClErrorString(errcode));
      }
      NaClPerfCounterMark(&time_all_main, "BlobLoaded");
      NaClPerfCounterIntervalLast(&time_all_main);
    }

    if (-1 == (*((struct Gio *) &blob_file)->vtbl->Close)((struct Gio *)
                                                          &blob_file)) {
      fprintf(stderr, "Error while closing \"%s\".\n", blob_library_file);
    }
    (*((struct Gio *) &blob_file)->vtbl->Dtor)((struct Gio *) &blob_file);
    if (verbosity) {
      gprintf((struct Gio *) &gout, "printing post-IRT NaClApp details\n");
      NaClAppPrintDetails(nap, (struct Gio *) &gout);
    }
  }

  /*
   * Print out a marker for scripts to use to mark the start of app
   * output.
   */
  NaClLog(1, "NACL: Application output follows\n");

  /*
   * Make sure all the file buffers are flushed before entering
   * the application code.
   */
  fflush((FILE *) NULL);

  if (NULL != nap->secure_service) {
    NaClErrorCode start_result;
    /*
     * wait for start_module RPC call on secure channel thread.
     */
    start_result = NaClWaitForStartModuleCommand(nap);
    NaClPerfCounterMark(&time_all_main, "WaitedForStartModuleCommand");
    NaClPerfCounterIntervalLast(&time_all_main);
    if (LOAD_OK == errcode) {
      errcode = start_result;
    }
  }

  /*
   * error reporting done; can quit now if there was an error earlier.
   */
  if (LOAD_OK != errcode) {
    NaClLog(4,
            "Not running app code since errcode is %s (%d)\n",
            NaClErrorString(errcode),
            errcode);
    goto done;
  }

  if (!DynArraySet(&env_vars, env_vars.num_entries, NULL)) {
    NaClLog(LOG_FATAL, "Adding env_vars NULL terminator failed\n");
  }

  NaClEnvCleanserCtor(&env_cleanser, 0);
  if (!NaClEnvCleanserInit(&env_cleanser, envp,
          (char const *const *)env_vars.ptr_array)) {
    NaClLog(LOG_FATAL, "Failed to initialise env cleanser\n");
  }

  if (!NaClAppLaunchServiceThreads(nap)) {
    fprintf(stderr, "Launch service threads failed\n");
    goto done;
  }
  if (enable_debug_stub) {
    if (!NaClDebugInit(nap)) {
      goto done;
    }
  }
  NACL_TEST_INJECTION(BeforeMainThreadLaunches, ());
  if (!NaClCreateMainThread(nap,
                            argc - optind,
                            argv + optind,
                            NaClEnvCleanserEnvironment(&env_cleanser))) {
    fprintf(stderr, "creating main thread failed\n");
    goto done;
  }

  NaClEnvCleanserDtor(&env_cleanser);

  NaClPerfCounterMark(&time_all_main, "CreateMainThread");
  NaClPerfCounterIntervalLast(&time_all_main);
  DynArrayDtor(&env_vars);

  ret_code = NaClWaitForMainThreadToExit(nap);
  NaClPerfCounterMark(&time_all_main, "WaitForMainThread");
  NaClPerfCounterIntervalLast(&time_all_main);

  NaClPerfCounterMark(&time_all_main, "SelMainEnd");
  NaClPerfCounterIntervalTotal(&time_all_main);

  /*
   * exit_group or equiv kills any still running threads while module
   * addr space is still valid.  otherwise we'd have to kill threads
   * before we clean up the address space.
   */
  NaClExit(ret_code);

 done:
  fflush(stdout);

  if (verbosity) {
    gprintf((struct Gio *) &gout, "exiting -- printing NaClApp details\n");
    NaClAppPrintDetails(nap, (struct Gio *) &gout);

    printf("Dumping vmmap.\n"); fflush(stdout);
    PrintVmmap(nap);
    fflush(stdout);
  }
  /*
   * If there is a secure command channel, we sent an RPC reply with
   * the reason that the nexe was rejected.  If we exit now, that
   * reply may still be in-flight and the various channel closure (esp
   * reverse channel) may be detected first.  This would result in a
   * crash being reported, rather than the error in the RPC reply.
   * Instead, we wait for the hard-shutdown on the command channel.
   */
  if (LOAD_OK != errcode) {
    NaClBlockIfCommandChannelExists(nap);
  }

  if (verbosity > 0) {
    printf("Done.\n");
  }
  fflush(stdout);

  if (handle_signals) NaClSignalHandlerFini();
  NaClAllModulesFini();

  NaClExit(ret_code);

  /* Unreachable, but having the return prevents a compiler error. */
  return ret_code;
}
コード例 #2
0
int NaClMainForChromium(int handle_count, const NaClHandle *handles,
                        int debug) {
  char *av[1];
  int ac = 1;
  const char **envp;
  struct NaClApp state;
  int main_thread_only = 1;
  int export_addr_to = kSrpcFd; /* Used to be set by -X. */
  struct NaClApp *nap;
  NaClErrorCode errcode;
  int ret_code = 1;
  struct NaClEnvCleanser env_cleanser;

#if NACL_OSX
  /* Mac dynamic libraries cannot access the environ variable directly. */
  envp = (const char **) *_NSGetEnviron();
#else
  /* Overzealous code style check is overzealous. */
  /* @IGNORE_LINES_FOR_CODE_HYGIENE[1] */
  extern char **environ;
  envp = (const char **) environ;
#endif

  NaClAllModulesInit();

  /* Add a handler to catch untrusted errors only */
  NaClSignalHandlerAdd(NaClSignalHandleUntrusted);

  /* to be passed to NaClMain, eventually... */
  av[0] = "NaClMain";

  if (!NaClAppCtor(&state)) {
    fprintf(stderr, "Error while constructing app state\n");
    goto done;
  }

  state.restrict_to_main_thread = main_thread_only;

  nap = &state;
  errcode = LOAD_OK;

  /* import IMC handle - used to be "-i" */
  CHECK(handle_count == 3);
  NaClAddImcHandle(nap, handles[0], export_addr_to);
  NaClAddImcHandle(nap, handles[1], 6); /* async_receive_desc */
  NaClAddImcHandle(nap, handles[2], 7); /* async_send_desc */

  /*
   * in order to report load error to the browser plugin through the
   * secure command channel, we do not immediate jump to cleanup code
   * on error.  rather, we continue processing (assuming earlier
   * errors do not make it inappropriate) until the secure command
   * channel is set up, and then bail out.
   */

  /*
   * Ensure this operating system platform is supported.
   */
  errcode = NaClRunSelQualificationTests();
  if (LOAD_OK != errcode) {
    nap->module_load_status = errcode;
    fprintf(stderr, "Error while loading in SelMain: %s\n",
            NaClErrorString(errcode));
  }

  /* Give debuggers a well known point at which xlate_base is known.  */
  NaClGdbHook(&state);

  /*
   * If export_addr_to is set to a non-negative integer, we create a
   * bound socket and socket address pair and bind the former to
   * descriptor 3 and the latter to descriptor 4.  The socket address
   * is written out to the export_addr_to descriptor.
   *
   * The service runtime also accepts a connection on the bound socket
   * and spawns a secure command channel thread to service it.
   *
   * If export_addr_to is -1, we only create the bound socket and
   * socket address pair, and we do not export to an IMC socket.  This
   * use case is typically only used in testing, where we only "dump"
   * the socket address to stdout or similar channel.
   */
  if (-2 < export_addr_to) {
    NaClCreateServiceSocket(nap);
    if (0 <= export_addr_to) {
      NaClSendServiceAddressTo(nap, export_addr_to);
      /*
       * NB: spawns a thread that uses the command channel.  we do
       * this after NaClAppLoadFile so that NaClApp object is more
       * fully populated.  Hereafter any changes to nap should be done
       * while holding locks.
       */
      NaClSecureCommandChannel(nap);
    }
  }

  if (NULL != nap->secure_channel && LOAD_OK == errcode) {
    /*
     * wait for start_module RPC call on secure channel thread.
     */
    errcode = NaClWaitForStartModuleCommand(nap);
  }

  /*
   * error reporting done; can quit now if there was an error earlier.
   */
  if (LOAD_OK != errcode) {
    goto done;
  }


  /*
   * Enable debugging if requested.
   */
  if (debug) NaClDebugSetAllow(1);

  NaClEnvCleanserCtor(&env_cleanser);
  if (!NaClEnvCleanserInit(&env_cleanser, envp)) {
    NaClLog(LOG_FATAL, "Failed to initialise env cleanser\n");
  }

  /*
   * only nap->ehdrs.e_entry is usable, no symbol table is
   * available.
   */
  if (!NaClCreateMainThread(nap, ac, av,
                            NaClEnvCleanserEnvironment(&env_cleanser))) {
    fprintf(stderr, "creating main thread failed\n");
    goto done;
  }

  NaClEnvCleanserDtor(&env_cleanser);

  ret_code = NaClWaitForMainThreadToExit(nap);

  /*
   * exit_group or equiv kills any still running threads while module
   * addr space is still valid.  otherwise we'd have to kill threads
   * before we clean up the address space.
   */
  return ret_code;

 done:
  fflush(stdout);

  NaClAllModulesFini();

  return ret_code;
}
コード例 #3
0
static int LoadApp(struct NaClApp *nap, struct NaClChromeMainArgs *args) {
  NaClErrorCode errcode = LOAD_OK;
  int has_bootstrap_channel = args->imc_bootstrap_handle != NACL_INVALID_HANDLE;

  CHECK(g_initialized);

  /* Allow or disallow dyncode API based on args. */
  nap->enable_dyncode_syscalls = args->enable_dyncode_syscalls;
  nap->initial_nexe_max_code_bytes = args->initial_nexe_max_code_bytes;
  nap->pnacl_mode = args->pnacl_mode;

#if NACL_LINUX
  g_prereserved_sandbox_size = args->prereserved_sandbox_size;
#endif
#if NACL_LINUX || NACL_OSX
  /*
   * Overwrite value of sc_nprocessors_onln set in NaClAppCtor.  In
   * the Chrome embedding, the outer sandbox was already enabled when
   * the NaClApp Ctor was invoked, so a bogus value was written in
   * sc_nprocessors_onln.
   */
  if (-1 != args->number_of_cores) {
    nap->sc_nprocessors_onln = args->number_of_cores;
  }
#endif

  if (args->create_memory_object_func != NULL)
    NaClSetCreateMemoryObjectFunc(args->create_memory_object_func);

  /* Inject the validation caching interface, if it exists. */
  nap->validation_cache = args->validation_cache;

#if NACL_WINDOWS
  if (args->broker_duplicate_handle_func != NULL)
    NaClSetBrokerDuplicateHandleFunc(args->broker_duplicate_handle_func);
#endif

  NaClAppInitialDescriptorHookup(nap);

  /*
   * NACL_SERVICE_PORT_DESCRIPTOR and NACL_SERVICE_ADDRESS_DESCRIPTOR
   * are 3 and 4.
   */

  /*
   * in order to report load error to the browser plugin through the
   * secure command channel, we do not immediate jump to cleanup code
   * on error.  rather, we continue processing (assuming earlier
   * errors do not make it inappropriate) until the secure command
   * channel is set up, and then bail out.
   */

  /*
   * Ensure this operating system platform is supported.
   */
  if (args->skip_qualification) {
    fprintf(stderr, "PLATFORM QUALIFICATION DISABLED - "
        "Native Client's sandbox will be unreliable!\n");
  } else {
    errcode = NACL_FI_VAL("pq", NaClErrorCode,
                          NaClRunSelQualificationTests());
    if (LOAD_OK != errcode) {
      nap->module_load_status = errcode;
      fprintf(stderr, "Error while loading in SelMain: %s\n",
              NaClErrorString(errcode));
    }
  }

  /*
   * Patch the Windows exception dispatcher to be safe in the case
   * of faults inside x86-64 sandboxed code.  The sandbox is not
   * secure on 64-bit Windows without this.
   */
#if (NACL_WINDOWS && NACL_ARCH(NACL_BUILD_ARCH) == NACL_x86 && \
     NACL_BUILD_SUBARCH == 64)
  NaClPatchWindowsExceptionDispatcher();
#endif
  NaClSignalTestCrashOnStartup();

  nap->enable_exception_handling = args->enable_exception_handling;

  if (args->enable_exception_handling || args->enable_debug_stub) {
#if NACL_LINUX
    /* NaCl's signal handler is always enabled on Linux. */
#elif NACL_OSX
    if (!NaClInterceptMachExceptions()) {
      NaClLog(LOG_FATAL, "LoadApp: Failed to set up Mach exception handler\n");
    }
#elif NACL_WINDOWS
    nap->attach_debug_exception_handler_func =
        args->attach_debug_exception_handler_func;
#else
# error Unknown host OS
#endif
  }
#if NACL_LINUX
  NaClSignalHandlerInit();
#endif

  /* Give debuggers a well known point at which xlate_base is known.  */
  NaClGdbHook(nap);

  if (has_bootstrap_channel) {
    NaClCreateServiceSocket(nap);
    /*
     * LOG_FATAL errors that occur before NaClSetUpBootstrapChannel will
     * not be reported via the crash log mechanism (for Chromium
     * embedding of NaCl, shown in the JavaScript console).
     *
     * Some errors, such as due to NaClRunSelQualificationTests, do not
     * trigger a LOG_FATAL but instead set module_load_status to be sent
     * in the start_module RPC reply.  Log messages associated with such
     * errors would be seen, since NaClSetUpBootstrapChannel will get
     * called.
     */
    NaClSetUpBootstrapChannel(nap, args->imc_bootstrap_handle);
  }

  CHECK(args->nexe_desc != NULL);
  NaClAppLoadModule(nap, args->nexe_desc, NULL, NULL);
  NaClDescUnref(args->nexe_desc);
  args->nexe_desc = NULL;

  if (has_bootstrap_channel) {
    NACL_FI_FATAL("BeforeSecureCommandChannel");
    /*
     * Spawns a thread that uses the command channel.
     * Hereafter any changes to nap should be done while holding locks.
     */
    NaClSecureCommandChannel(nap);

    NaClLog(4, "NaClSecureCommandChannel has spawned channel\n");

    NaClLog(4, "secure service = %"NACL_PRIxPTR"\n",
            (uintptr_t) nap->secure_service);

  }

  NACL_FI_FATAL("BeforeLoadIrt");

  /*
   * error reporting done; can quit now if there was an error earlier.
   */
  if (LOAD_OK == errcode) {
    errcode = NaClGetLoadStatus(nap);
  }
  if (LOAD_OK != errcode) {
    goto done;
  }

  /*
   * Load the integrated runtime (IRT) library.
   * Skip if irt_load_optional and the nexe doesn't have the usual 256MB
   * segment gap. PNaCl's disabling of the segment gap doesn't actually
   * disable the segment gap. It only only reduces it drastically.
   */
  if (args->irt_load_optional && nap->dynamic_text_end < 0x10000000) {
    NaClLog(1,
            "Skipped NaClLoadIrt, irt_load_optional with dynamic_text_end: %"
            NACL_PRIxPTR"\n", nap->dynamic_text_end);
  } else {
    if (args->irt_fd != -1) {
      CHECK(args->irt_desc == NULL);
      args->irt_desc = IrtDescFromFd(args->irt_fd);
      args->irt_fd = -1;
    }
    if (args->irt_desc != NULL) {
      NaClLoadIrt(nap, args->irt_desc);
      NaClDescUnref(args->irt_desc);
      args->irt_desc = NULL;
    }
  }

  if (args->enable_debug_stub) {
#if NACL_LINUX || NACL_OSX
    if (args->debug_stub_server_bound_socket_fd != NACL_INVALID_SOCKET) {
      NaClDebugSetBoundSocket(args->debug_stub_server_bound_socket_fd);
    }
#endif
    if (!NaClDebugInit(nap)) {
      goto done;
    }
#if NACL_WINDOWS
    if (NULL != args->debug_stub_server_port_selected_handler_func) {
      args->debug_stub_server_port_selected_handler_func(nap->debug_stub_port);
    }
#endif
  }

  if (args->load_status_handler_func != NULL) {
    args->load_status_handler_func(LOAD_OK);
  }
  return LOAD_OK;

done:
  fflush(stdout);

  /*
   * If there is a load status callback, call that now and transfer logs
   * in preparation for process exit.
   */
  if (args->load_status_handler_func != NULL) {
    /* Don't return LOAD_OK if we had some failure loading. */
    if (LOAD_OK == errcode) {
      errcode = LOAD_INTERNAL;
    }
    args->load_status_handler_func(errcode);
    NaClLog(LOG_ERROR, "NaCl LoadApp failed. Transferring logs before exit.\n");
    NaClLogRunAbortBehavior();
    /*
     * Fall through and run NaClBlockIfCommandChannelExists.
     * TODO(jvoung): remove NaClBlockIfCommandChannelExists() and use the
     * callback to indicate the load_status after Chromium no longer calls
     * start_module. We also need to change Chromium so that it does not
     * attempt to set up the command channel if there is a known load error.
     * Otherwise there is a race between this process's exit / load error
     * reporting, and the command channel setup on the Chromium side (plus
     * the associated reporting). Thus this could end up with two different
     * load errors being reported (1) the real load error from here, and
     * (2) the command channel setup failure because the process exited in
     * the middle of setting up the command channel.
     */
  }
  /*
   * If there is a secure command channel, we sent an RPC reply with
   * the reason that the nexe was rejected.  If we exit now, that
   * reply may still be in-flight and the various channel closure (esp
   * reverse channel) may be detected first.  This would result in a
   * crash being reported, rather than the error in the RPC reply.
   * Instead, we wait for the hard-shutdown on the command channel.
   */
  if (LOAD_OK != errcode) {
    NaClBlockIfCommandChannelExists(nap);
  } else {
    /*
     * Don't return LOAD_OK if we had some failure loading.
     */
    errcode = LOAD_INTERNAL;
  }
  return errcode;
}