content/common/sandbox_util.cc

   1 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style license that can be
   3 // found in the LICENSE file.
   4
   5 #include "content/common/sandbox_util.h"
   6
   7 #if defined(OS_POSIX)
   8 #include <unistd.h>
   9 #endif
  10
  11 #include "content/public/common/sandbox_init.h"
  12
  13 namespace content {
  14
  15 IPC::PlatformFileForTransit BrokerGetFileHandleForProcess(
  16     base::PlatformFile handle,
  17     base::ProcessId target_process_id,
  18     bool should_close_source) {
  19   IPC::PlatformFileForTransit out_handle;
  20 #if defined(OS_WIN)
  21   DWORD options = DUPLICATE_SAME_ACCESS;
  22   if (should_close_source)
  23     options |= DUPLICATE_CLOSE_SOURCE;
  24   if (!content::BrokerDuplicateHandle(handle, target_process_id, &out_handle,
  25                                       0, options)) {
  26     out_handle = IPC::InvalidPlatformFileForTransit();
  27   }
  28 #elif defined(OS_POSIX)
  29   // If asked to close the source, we can simply re-use the source fd instead of
  30   // dup()ing and close()ing.
  31   // When we're not closing the source, we need to duplicate the handle and take
  32   // ownership of that. The reason is that this function is often used to
  33   // generate IPC messages, and the handle must remain valid until it's sent to
  34   // the other process from the I/O thread. Without the dup, calling code might
  35   // close the source handle before the message is sent, creating a race
  36   // condition.
  37   int fd = should_close_source ? handle : ::dup(handle);
  38   out_handle = base::FileDescriptor(fd, true);
  39 #else
  40   #error Not implemented.
  41 #endif
  42   return out_handle;
  43 }
  44
  45 }  // namespace content
  46