ppapi/native_client/src/untrusted/pnacl_irt_shim/irt_shim_ppapi.c

   1 /*
   2  * Copyright 2014 The Chromium Authors. All rights reserved.
   3  * Use of this source code is governed by a BSD-style license that can be
   4  * found in the LICENSE file.
   5  */
   6
   7 #include "ppapi/native_client/src/untrusted/pnacl_irt_shim/irt_shim_ppapi.h"
   8
   9 #include "native_client/src/untrusted/irt/irt.h"
  10 #include "ppapi/nacl_irt/public/irt_ppapi.h"
  11 #include "ppapi/native_client/src/untrusted/pnacl_irt_shim/pnacl_shim.h"
  12 #include "ppapi/nacl_irt/plugin_main.h"
  13
  14 /*
  15  * Defines a version of the version irt_ppapi_start and of the irt_ppapihook
  16  * that returns a shimmed GetInterface for PNaCl.
  17  *
  18  * The hook will be linked into the IRT but it is considered unstable.
  19  * Stable nexes should not use that IRT hook (and a filter prevents
  20  * it from being used). Instead PNaCl nexes should embed the
  21  * irt_shim_ppapi_start and the shim functions directly into the nexe
  22  * for ABI stability.
  23  */
  24
  25 static struct PP_StartFunctions g_user_start_functions;
  26
  27 static int32_t shim_PPPInitializeModule(PP_Module module_id,
  28                                         PPB_GetInterface get_browser_intf) {
  29   /* Record the original PPB_GetInterface and provide a shimmed one. */
  30   __set_real_Pnacl_PPBGetInterface(get_browser_intf);
  31   return (*g_user_start_functions.PPP_InitializeModule)(
  32       module_id,
  33       &__Pnacl_PPBGetInterface);
  34 }
  35
  36 static void shim_PPPShutdownModule(void) {
  37   (*g_user_start_functions.PPP_ShutdownModule)();
  38 }
  39
  40 #ifdef PNACL_SHIM_AOT
  41  /*
  42   * This will be discovered and set by the shim, since we cannot link
  43   * against the IRT directly in the AOT library.
  44   */
  45 int (*real_irt_ppapi_start)(const struct PP_StartFunctions *) = NULL;
  46 #else
  47  /*
  48   * Otherwise, when linking directly into the IRT, we can refer to the
  49   * real irt_ppapi_start from irt_ppapi.
  50   */
  51 extern int irt_ppapi_start(const struct PP_StartFunctions *);
  52 static int (* const real_irt_ppapi_start)(const struct PP_StartFunctions *) =
  53     &irt_ppapi_start;
  54 #endif
  55
  56 int irt_shim_ppapi_start(const struct PP_StartFunctions *funcs) {
  57   g_user_start_functions = *funcs;
  58   /*
  59    * Record the original PPP_GetInterface and provide a shimmed one
  60    * via wrapped_ppapi_methods.
  61    */
  62   const struct PP_StartFunctions wrapped_ppapi_methods = {
  63     shim_PPPInitializeModule,
  64     shim_PPPShutdownModule,
  65     __Pnacl_PPPGetInterface
  66   };
  67   __set_real_Pnacl_PPPGetInterface(g_user_start_functions.PPP_GetInterface);
  68   /*
  69    * Invoke the IRT's ppapi_start interface with the wrapped interface.
  70    */
  71   return (*real_irt_ppapi_start)(&wrapped_ppapi_methods);
  72 }
  73
  74 #ifndef PNACL_SHIM_AOT
  75 const struct nacl_irt_ppapihook nacl_irt_ppapihook_pnacl_private = {
  76   irt_shim_ppapi_start,
  77   PpapiPluginRegisterThreadCreator,
  78 };
  79 #endif