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
13namespace content {
14
15IPC::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
47