RFC: Add an interface for having the browser open a pnacl support file

chrome/renderer/chrome_ppapi_interfaces.cc

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "chrome/renderer/chrome_ppapi_interfaces.h"
 
 #include "base/command_line.h"
 #include "base/lazy_instance.h"
 #include "base/logging.h"
 #include "base/rand_util_c.h"
@@ skipping 51 matching lines @@
 }
 
 int UrandomFD(void) {
 #if defined(OS_POSIX)
   return GetUrandomFD();
 #else
   return 0;
 #endif
 }
 
+int GetReadonlyPnaclFD(const char* filename) {
+  nacl::FileDescriptor out_fd;
+  if (!RenderThread::Get()->Send(
+      new ChromeViewHostMsg_GetReadonlyPnaclFD(
+          std::string(filename),
+          &out_fd))) {
+    return -1;
+  }
+
+  // TODO(jvoung): Should nacl::FileDescriptor handle this?
+  // Should we leave the HANDLE as a HANDLE for now?
+#if defined(OS_WIN)
+  HANDLE handle = nacl::ToNativeHandle(out_fd);
+  int posix_desc = _open_osfhandle(handle, _O_RDONLY | _O_BINARY);
+  if (posix_desc == -1) {
+    // Close the Windows HANDLE if it can't be converted.
+    CloseHandle(handle);
+    return -1;
+  }
+  return posix_desc;
+#elif defined(OS_POSIX)
+  return nacl::ToNativeHandle(out_fd);
+#else
+#error "GetReadonlyPnaclFD: Don't know how to convert FileDescriptor to native."
+#endif
+}
+
 bool Are3DInterfacesDisabled() {
   return CommandLine::ForCurrentProcess()->HasSwitch(switches::kDisable3DAPIs);
 }
 
 void EnableBackgroundSelLdrLaunch() {
   g_background_thread_sender.Get() =
       RenderThread::Get()->GetSyncMessageFilter();
 }
 
 const PPB_NaCl_Private ppb_nacl = {
   &LaunchSelLdr,
   &UrandomFD,
   &Are3DInterfacesDisabled,
   &EnableBackgroundSelLdrLaunch,
+  &GetReadonlyPnaclFD
 };
 
 class PPB_NaCl_Impl {
  public:
   // Returns a pointer to the interface implementing PPB_NaCl_Private that is
   // exposed to the plugin.
   static const PPB_NaCl_Private* GetInterface() {
     return &ppb_nacl;
   }
 };
 #endif  // DISABLE_NACL
 
 const void* ChromePPAPIInterfaceFactory(const std::string& interface_name) {
 #if !defined(DISABLE_NACL)
   if (interface_name == PPB_NACL_PRIVATE_INTERFACE)
     return chrome::PPB_NaCl_Impl::GetInterface();
 #endif  // DISABLE_NACL
   if (interface_name == PPB_PDF_INTERFACE)
     return chrome::PPB_PDF_Impl::GetInterface();
   return NULL;
 }
 
 }  // namespace chrome