1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
|
// Copyright 2012 The Chromium Authors
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
#include "build/build_config.h"
#include "ipc/ipc_platform_file.h"
#if BUILDFLAG(IS_WIN)
#include <windows.h>
#include "base/win/windows_handle_util.h"
#elif BUILDFLAG(IS_POSIX) || BUILDFLAG(IS_FUCHSIA)
#include <unistd.h>
#include "base/posix/eintr_wrapper.h"
#endif
namespace IPC {
#if BUILDFLAG(IS_WIN)
PlatformFileForTransit::PlatformFileForTransit() : handle_(nullptr) {}
PlatformFileForTransit::PlatformFileForTransit(HANDLE handle) {
// Refuse to represent handles that cannot be sent in transit, if it is
// necessary to send a process or thread handle callers should duplicate them
// before construction.
if (!handle || base::win::IsPseudoHandle(handle)) {
handle_ = nullptr;
return;
}
handle_ = handle;
}
bool PlatformFileForTransit::operator==(
const PlatformFileForTransit& platform_file) const {
return handle_ == platform_file.handle_;
}
bool PlatformFileForTransit::operator!=(
const PlatformFileForTransit& platform_file) const {
return !(*this == platform_file);
}
HANDLE PlatformFileForTransit::GetHandle() const {
return handle_;
}
bool PlatformFileForTransit::IsValid() const {
return handle_ != nullptr;
}
#endif // BUILDFLAG(IS_WIN)
PlatformFileForTransit GetPlatformFileForTransit(base::PlatformFile handle,
bool close_source_handle) {
#if BUILDFLAG(IS_WIN)
HANDLE raw_handle = nullptr;
DWORD options = DUPLICATE_SAME_ACCESS;
if (close_source_handle) {
options |= DUPLICATE_CLOSE_SOURCE;
}
// Avoid duplicating pseudo handle values like ::GetCurrentProcess().
if (!handle || base::win::IsPseudoHandle(handle) ||
!::DuplicateHandle(::GetCurrentProcess(), handle, ::GetCurrentProcess(),
&raw_handle, 0, FALSE, options)) {
return IPC::InvalidPlatformFileForTransit();
}
return IPC::PlatformFileForTransit(raw_handle);
#elif BUILDFLAG(IS_POSIX) || BUILDFLAG(IS_FUCHSIA)
// If asked to close the source, we can simply re-use the source fd instead of
// dup()ing and close()ing.
// When we're not closing the source, we need to duplicate the handle and take
// ownership of that. The reason is that this function is often used to
// generate IPC messages, and the handle must remain valid until it's sent to
// the other process from the I/O thread. Without the dup, calling code might
// close the source handle before the message is sent, creating a race
// condition.
int fd = close_source_handle ? handle : HANDLE_EINTR(::dup(handle));
return base::FileDescriptor(fd, true);
#endif
}
PlatformFileForTransit TakePlatformFileForTransit(base::File file) {
return GetPlatformFileForTransit(file.TakePlatformFile(), true);
}
} // namespace IPC
|
