|
1 // Copyright (c) 2007, Google Inc. |
|
2 // All rights reserved. |
|
3 // |
|
4 // Redistribution and use in source and binary forms, with or without |
|
5 // modification, are permitted provided that the following conditions are |
|
6 // met: |
|
7 // |
|
8 // * Redistributions of source code must retain the above copyright |
|
9 // notice, this list of conditions and the following disclaimer. |
|
10 // * Redistributions in binary form must reproduce the above |
|
11 // copyright notice, this list of conditions and the following disclaimer |
|
12 // in the documentation and/or other materials provided with the |
|
13 // distribution. |
|
14 // * Neither the name of Google Inc. nor the names of its |
|
15 // contributors may be used to endorse or promote products derived from |
|
16 // this software without specific prior written permission. |
|
17 // |
|
18 // THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS |
|
19 // "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT |
|
20 // LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR |
|
21 // A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT |
|
22 // OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, |
|
23 // SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT |
|
24 // LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, |
|
25 // DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY |
|
26 // THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT |
|
27 // (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE |
|
28 // OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. |
|
29 // |
|
30 // MachIPC.h |
|
31 // |
|
32 // Some helpful wrappers for using Mach IPC calls |
|
33 |
|
34 #ifndef MACH_IPC_H__ |
|
35 #define MACH_IPC_H__ |
|
36 |
|
37 #import <mach/mach.h> |
|
38 #import <mach/message.h> |
|
39 #import <servers/bootstrap.h> |
|
40 #import <sys/types.h> |
|
41 |
|
42 #import <CoreServices/CoreServices.h> |
|
43 |
|
44 //============================================================================== |
|
45 // DISCUSSION: |
|
46 // |
|
47 // The three main classes of interest are |
|
48 // |
|
49 // MachMessage: a wrapper for a mach message of the following form |
|
50 // mach_msg_header_t |
|
51 // mach_msg_body_t |
|
52 // optional descriptors |
|
53 // optional extra message data |
|
54 // |
|
55 // MachReceiveMessage and MachSendMessage subclass MachMessage |
|
56 // and are used instead of MachMessage which is an abstract base class |
|
57 // |
|
58 // ReceivePort: |
|
59 // Represents a mach port for which we have receive rights |
|
60 // |
|
61 // MachPortSender: |
|
62 // Represents a mach port for which we have send rights |
|
63 // |
|
64 // Here's an example to receive a message on a server port: |
|
65 // |
|
66 // // This creates our named server port |
|
67 // ReceivePort receivePort("com.Google.MyService"); |
|
68 // |
|
69 // MachReceiveMessage message; |
|
70 // kern_return_t result = receivePort.WaitForMessage(&message, 0); |
|
71 // |
|
72 // if (result == KERN_SUCCESS && message.GetMessageID() == 57) { |
|
73 // mach_port_t task = message.GetTranslatedPort(0); |
|
74 // mach_port_t thread = message.GetTranslatedPort(1); |
|
75 // |
|
76 // char *messageString = message.GetData(); |
|
77 // |
|
78 // printf("message string = %s\n", messageString); |
|
79 // } |
|
80 // |
|
81 // Here is an example of using these classes to send a message to this port: |
|
82 // |
|
83 // // send to already named port |
|
84 // MachPortSender sender("com.Google.MyService"); |
|
85 // MachSendMessage message(57); // our message ID is 57 |
|
86 // |
|
87 // // add some ports to be translated for us |
|
88 // message.AddDescriptor(mach_task_self()); // our task |
|
89 // message.AddDescriptor(mach_thread_self()); // this thread |
|
90 // |
|
91 // char messageString[] = "Hello server!\n"; |
|
92 // message.SetData(messageString, strlen(messageString)+1); |
|
93 // |
|
94 // kern_return_t result = sender.SendMessage(message, 1000); // timeout 1000ms |
|
95 // |
|
96 |
|
97 namespace google_breakpad { |
|
98 #define PRINT_MACH_RESULT(result_, message_) \ |
|
99 printf(message_" %s (%d)\n", mach_error_string(result_), result_ ); |
|
100 |
|
101 //============================================================================== |
|
102 // A wrapper class for mach_msg_port_descriptor_t (with same memory layout) |
|
103 // with convenient constructors and accessors |
|
104 class MachMsgPortDescriptor : public mach_msg_port_descriptor_t { |
|
105 public: |
|
106 // General-purpose constructor |
|
107 MachMsgPortDescriptor(mach_port_t in_name, |
|
108 mach_msg_type_name_t in_disposition) { |
|
109 name = in_name; |
|
110 pad1 = 0; |
|
111 pad2 = 0; |
|
112 disposition = in_disposition; |
|
113 type = MACH_MSG_PORT_DESCRIPTOR; |
|
114 } |
|
115 |
|
116 // For passing send rights to a port |
|
117 MachMsgPortDescriptor(mach_port_t in_name) { |
|
118 name = in_name; |
|
119 pad1 = 0; |
|
120 pad2 = 0; |
|
121 disposition = MACH_MSG_TYPE_COPY_SEND; |
|
122 type = MACH_MSG_PORT_DESCRIPTOR; |
|
123 } |
|
124 |
|
125 // Copy constructor |
|
126 MachMsgPortDescriptor(const MachMsgPortDescriptor& desc) { |
|
127 name = desc.name; |
|
128 pad1 = desc.pad1; |
|
129 pad2 = desc.pad2; |
|
130 disposition = desc.disposition; |
|
131 type = desc.type; |
|
132 } |
|
133 |
|
134 mach_port_t GetMachPort() const { |
|
135 return name; |
|
136 } |
|
137 |
|
138 mach_msg_type_name_t GetDisposition() const { |
|
139 return disposition; |
|
140 } |
|
141 |
|
142 // For convenience |
|
143 operator mach_port_t() const { |
|
144 return GetMachPort(); |
|
145 } |
|
146 }; |
|
147 |
|
148 //============================================================================== |
|
149 // MachMessage: a wrapper for a mach message |
|
150 // (mach_msg_header_t, mach_msg_body_t, extra data) |
|
151 // |
|
152 // This considerably simplifies the construction of a message for sending |
|
153 // and the getting at relevant data and descriptors for the receiver. |
|
154 // |
|
155 // Currently the combined size of the descriptors plus data must be |
|
156 // less than 1024. But as a benefit no memory allocation is necessary. |
|
157 // |
|
158 // TODO: could consider adding malloc() support for very large messages |
|
159 // |
|
160 // A MachMessage object is used by ReceivePort::WaitForMessage |
|
161 // and MachPortSender::SendMessage |
|
162 // |
|
163 class MachMessage { |
|
164 public: |
|
165 |
|
166 // The receiver of the message can retrieve the raw data this way |
|
167 uint8_t *GetData() { |
|
168 return GetDataLength() > 0 ? GetDataPacket()->data : NULL; |
|
169 } |
|
170 |
|
171 uint32_t GetDataLength() { |
|
172 return EndianU32_LtoN(GetDataPacket()->data_length); |
|
173 } |
|
174 |
|
175 // The message ID may be used as a code identifying the type of message |
|
176 void SetMessageID(int32_t message_id) { |
|
177 GetDataPacket()->id = EndianU32_NtoL(message_id); |
|
178 } |
|
179 |
|
180 int32_t GetMessageID() { return EndianU32_LtoN(GetDataPacket()->id); } |
|
181 |
|
182 // Adds a descriptor (typically a mach port) to be translated |
|
183 // returns true if successful, otherwise not enough space |
|
184 bool AddDescriptor(const MachMsgPortDescriptor &desc); |
|
185 |
|
186 int GetDescriptorCount() const { return body.msgh_descriptor_count; } |
|
187 MachMsgPortDescriptor *GetDescriptor(int n); |
|
188 |
|
189 // Convenience method which gets the mach port described by the descriptor |
|
190 mach_port_t GetTranslatedPort(int n); |
|
191 |
|
192 // A simple message is one with no descriptors |
|
193 bool IsSimpleMessage() const { return GetDescriptorCount() == 0; } |
|
194 |
|
195 // Sets raw data for the message (returns false if not enough space) |
|
196 bool SetData(void *data, int32_t data_length); |
|
197 |
|
198 protected: |
|
199 // Consider this an abstract base class - must create an actual instance |
|
200 // of MachReceiveMessage or MachSendMessage |
|
201 |
|
202 MachMessage() { |
|
203 memset(this, 0, sizeof(MachMessage)); |
|
204 } |
|
205 |
|
206 friend class ReceivePort; |
|
207 friend class MachPortSender; |
|
208 |
|
209 // Represents raw data in our message |
|
210 struct MessageDataPacket { |
|
211 int32_t id; // little-endian |
|
212 int32_t data_length; // little-endian |
|
213 uint8_t data[1]; // actual size limited by sizeof(MachMessage) |
|
214 }; |
|
215 |
|
216 MessageDataPacket* GetDataPacket(); |
|
217 |
|
218 void SetDescriptorCount(int n); |
|
219 void SetDescriptor(int n, const MachMsgPortDescriptor &desc); |
|
220 |
|
221 // Returns total message size setting msgh_size in the header to this value |
|
222 mach_msg_size_t CalculateSize(); |
|
223 |
|
224 mach_msg_header_t head; |
|
225 mach_msg_body_t body; |
|
226 uint8_t padding[1024]; // descriptors and data may be embedded here |
|
227 }; |
|
228 |
|
229 //============================================================================== |
|
230 // MachReceiveMessage and MachSendMessage are useful to separate the idea |
|
231 // of a mach message being sent and being received, and adds increased type |
|
232 // safety: |
|
233 // ReceivePort::WaitForMessage() only accepts a MachReceiveMessage |
|
234 // MachPortSender::SendMessage() only accepts a MachSendMessage |
|
235 |
|
236 //============================================================================== |
|
237 class MachReceiveMessage : public MachMessage { |
|
238 public: |
|
239 MachReceiveMessage() : MachMessage() {}; |
|
240 }; |
|
241 |
|
242 //============================================================================== |
|
243 class MachSendMessage : public MachMessage { |
|
244 public: |
|
245 MachSendMessage(int32_t message_id); |
|
246 }; |
|
247 |
|
248 //============================================================================== |
|
249 // Represents a mach port for which we have receive rights |
|
250 class ReceivePort { |
|
251 public: |
|
252 // Creates a new mach port for receiving messages and registers a name for it |
|
253 explicit ReceivePort(const char *receive_port_name); |
|
254 |
|
255 // Given an already existing mach port, use it. We take ownership of the |
|
256 // port and deallocate it in our destructor. |
|
257 explicit ReceivePort(mach_port_t receive_port); |
|
258 |
|
259 // Create a new mach port for receiving messages |
|
260 ReceivePort(); |
|
261 |
|
262 ~ReceivePort(); |
|
263 |
|
264 // Waits on the mach port until message received or timeout |
|
265 kern_return_t WaitForMessage(MachReceiveMessage *out_message, |
|
266 mach_msg_timeout_t timeout); |
|
267 |
|
268 // The underlying mach port that we wrap |
|
269 mach_port_t GetPort() const { return port_; } |
|
270 |
|
271 private: |
|
272 ReceivePort(const ReceivePort&); // disable copy c-tor |
|
273 |
|
274 mach_port_t port_; |
|
275 kern_return_t init_result_; |
|
276 }; |
|
277 |
|
278 //============================================================================== |
|
279 // Represents a mach port for which we have send rights |
|
280 class MachPortSender { |
|
281 public: |
|
282 // get a port with send rights corresponding to a named registered service |
|
283 explicit MachPortSender(const char *receive_port_name); |
|
284 |
|
285 |
|
286 // Given an already existing mach port, use it. |
|
287 explicit MachPortSender(mach_port_t send_port); |
|
288 |
|
289 kern_return_t SendMessage(MachSendMessage &message, |
|
290 mach_msg_timeout_t timeout); |
|
291 |
|
292 private: |
|
293 MachPortSender(const MachPortSender&); // disable copy c-tor |
|
294 |
|
295 mach_port_t send_port_; |
|
296 kern_return_t init_result_; |
|
297 }; |
|
298 |
|
299 } // namespace google_breakpad |
|
300 |
|
301 #endif // MACH_IPC_H__ |