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1 // Copyright (c) 2012 The Chromium Authors. All rights reserved. | 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 | 2 // Use of this source code is governed by a BSD-style license that can be |
3 // found in the LICENSE file. | 3 // found in the LICENSE file. |
4 | 4 |
5 #ifndef DBUS_FILE_DESCRIPTOR_H_ | 5 #ifndef DBUS_FILE_DESCRIPTOR_H_ |
6 #define DBUS_FILE_DESCRIPTOR_H_ | 6 #define DBUS_FILE_DESCRIPTOR_H_ |
7 | 7 |
8 #include "base/basictypes.h" | 8 #include "base/basictypes.h" |
9 #include "base/memory/scoped_ptr.h" | |
10 #include "dbus/dbus_export.h" | 9 #include "dbus/dbus_export.h" |
11 | 10 |
12 namespace dbus { | 11 namespace dbus { |
13 | 12 |
14 // FileDescriptor is a type used to encapsulate D-Bus file descriptors | 13 // FileDescriptor is a type used to encapsulate D-Bus file descriptors |
15 // and to follow the RAII idiom appropiate for use with message operations | 14 // and to follow the RAII idiom appropiate for use with message operations |
16 // where the descriptor might be easily leaked. To guard against this the | 15 // where the descriptor might be easily leaked. To guard against this the |
17 // descriptor is closed when an instance is destroyed if it is owned. | 16 // descriptor is closed when an instance is destroyed if it is owned. |
18 // Ownership is asserted only when PutValue is used and TakeValue can be | 17 // Ownership is asserted only when PutValue is used and TakeValue can be |
19 // used to take ownership. | 18 // used to take ownership. |
20 // | 19 // |
21 // For example, in the following | 20 // For example, in the following |
22 // FileDescriptor fd; | 21 // FileDescriptor fd; |
23 // if (!reader->PopString(&name) || | 22 // if (!reader->PopString(&name) || |
24 // !reader->PopFileDescriptor(&fd) || | 23 // !reader->PopFileDescriptor(&fd) || |
25 // !reader->PopUint32(&flags)) { | 24 // !reader->PopUint32(&flags)) { |
26 // the descriptor in fd will be closed if the PopUint32 fails. But | 25 // the descriptor in fd will be closed if the PopUint32 fails. But |
27 // writer.AppendFileDescriptor(dbus::FileDescriptor(1)); | 26 // writer.AppendFileDescriptor(dbus::FileDescriptor(1)); |
28 // will not automatically close "1" because it is not owned. | 27 // will not automatically close "1" because it is not owned. |
29 // | 28 // |
30 // Descriptors must be validated before marshalling in a D-Bus message | 29 // Descriptors must be validated before marshalling in a D-Bus message |
31 // or using them after unmarshalling. We disallow descriptors to a | 30 // or using them after unmarshalling. We disallow descriptors to a |
32 // directory to reduce the security risks. Splitting out validation | 31 // directory to reduce the security risks. Splitting out validation |
33 // also allows the caller to do this work on the File thread to conform | 32 // also allows the caller to do this work on the File thread to conform |
34 // with i/o restrictions. | 33 // with i/o restrictions. |
35 class CHROME_DBUS_EXPORT FileDescriptor { | 34 class CHROME_DBUS_EXPORT FileDescriptor { |
36 public: | 35 public: |
37 // This provides a simple way to pass around file descriptors since they must | |
38 // be closed on a thread that is allowed to perform I/O. | |
39 struct Deleter { | |
40 void CHROME_DBUS_EXPORT operator()(FileDescriptor* fd); | |
41 }; | |
42 | |
43 // Permits initialization without a value for passing to | 36 // Permits initialization without a value for passing to |
44 // dbus::MessageReader::PopFileDescriptor to fill in and from int values. | 37 // dbus::MessageReader::PopFileDescriptor to fill in and from int values. |
45 FileDescriptor() : value_(-1), owner_(false), valid_(false) {} | 38 FileDescriptor() : value_(-1), owner_(false), valid_(false) {} |
46 explicit FileDescriptor(int value) : value_(value), owner_(false), | 39 explicit FileDescriptor(int value) : value_(value), owner_(false), |
47 valid_(false) {} | 40 valid_(false) {} |
48 | 41 |
49 virtual ~FileDescriptor(); | 42 virtual ~FileDescriptor(); |
50 | 43 |
51 // Retrieves value as an int without affecting ownership. | 44 // Retrieves value as an int without affecting ownership. |
52 int value() const; | 45 int value() const; |
(...skipping 17 matching lines...) Expand all Loading... |
70 void CheckValidity(); | 63 void CheckValidity(); |
71 | 64 |
72 private: | 65 private: |
73 int value_; | 66 int value_; |
74 bool owner_; | 67 bool owner_; |
75 bool valid_; | 68 bool valid_; |
76 | 69 |
77 DISALLOW_COPY_AND_ASSIGN(FileDescriptor); | 70 DISALLOW_COPY_AND_ASSIGN(FileDescriptor); |
78 }; | 71 }; |
79 | 72 |
80 using ScopedFileDescriptor = | |
81 scoped_ptr<FileDescriptor, FileDescriptor::Deleter> CHROME_DBUS_EXPORT; | |
82 | |
83 } // namespace dbus | 73 } // namespace dbus |
84 | 74 |
85 #endif // DBUS_FILE_DESCRIPTOR_H_ | 75 #endif // DBUS_FILE_DESCRIPTOR_H_ |
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