binder.h revision 457b9a6f09f011ebcb9b52cc203a6331a6fc2de7 
1/*
2 * Copyright (C) 2008 Google, Inc.
3 *
4 * Based on, but no longer compatible with, the original
5 * OpenBinder.org binder driver interface, which is:
6 *
7 * Copyright (c) 2005 Palmsource, Inc.
8 *
9 * This software is licensed under the terms of the GNU General Public
10 * License version 2, as published by the Free Software Foundation, and
11 * may be copied, distributed, and modified under those terms.
12 *
13 * This program is distributed in the hope that it will be useful,
14 * but WITHOUT ANY WARRANTY; without even the implied warranty of
15 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
16 * GNU General Public License for more details.
17 *
18 */
19
20#ifndef _LINUX_BINDER_H
21#define _LINUX_BINDER_H
22
23#include <linux/ioctl.h>
24
25#define B_PACK_CHARS(c1, c2, c3, c4) \
26	((((c1)<<24)) | (((c2)<<16)) | (((c3)<<8)) | (c4))
27#define B_TYPE_LARGE 0x85
28
29enum {
30	BINDER_TYPE_BINDER	= B_PACK_CHARS('s', 'b', '*', B_TYPE_LARGE),
31	BINDER_TYPE_WEAK_BINDER	= B_PACK_CHARS('w', 'b', '*', B_TYPE_LARGE),
32	BINDER_TYPE_HANDLE	= B_PACK_CHARS('s', 'h', '*', B_TYPE_LARGE),
33	BINDER_TYPE_WEAK_HANDLE	= B_PACK_CHARS('w', 'h', '*', B_TYPE_LARGE),
34	BINDER_TYPE_FD		= B_PACK_CHARS('f', 'd', '*', B_TYPE_LARGE),
35};
36
37enum {
38	FLAT_BINDER_FLAG_PRIORITY_MASK = 0xff,
39	FLAT_BINDER_FLAG_ACCEPTS_FDS = 0x100,
40};
41
42/*
43 * This is the flattened representation of a Binder object for transfer
44 * between processes.  The 'offsets' supplied as part of a binder transaction
45 * contains offsets into the data where these structures occur.  The Binder
46 * driver takes care of re-writing the structure type and data as it moves
47 * between processes.
48 */
49struct flat_binder_object {
50	/* 8 bytes for large_flat_header. */
51	unsigned long		type;
52	unsigned long		flags;
53
54	/* 8 bytes of data. */
55	union {
56		void		*binder;	/* local object */
57		signed long	handle;		/* remote object */
58	};
59
60	/* extra data associated with local object */
61	void			*cookie;
62};
63
64/*
65 * On 64-bit platforms where user code may run in 32-bits the driver must
66 * translate the buffer (and local binder) addresses apropriately.
67 */
68
69struct binder_write_read {
70	signed long	write_size;	/* bytes to write */
71	signed long	write_consumed;	/* bytes consumed by driver */
72	unsigned long	write_buffer;
73	signed long	read_size;	/* bytes to read */
74	signed long	read_consumed;	/* bytes consumed by driver */
75	unsigned long	read_buffer;
76};
77
78/* Use with BINDER_VERSION, driver fills in fields. */
79struct binder_version {
80	/* driver protocol version -- increment with incompatible change */
81	signed long	protocol_version;
82};
83
84/* This is the current protocol version. */
85#define BINDER_CURRENT_PROTOCOL_VERSION 7
86
87#define BINDER_WRITE_READ   		_IOWR('b', 1, struct binder_write_read)
88#define	BINDER_SET_IDLE_TIMEOUT		_IOW('b', 3, int64_t)
89#define	BINDER_SET_MAX_THREADS		_IOW('b', 5, size_t)
90#define	BINDER_SET_IDLE_PRIORITY	_IOW('b', 6, int)
91#define	BINDER_SET_CONTEXT_MGR		_IOW('b', 7, int)
92#define	BINDER_THREAD_EXIT		_IOW('b', 8, int)
93#define BINDER_VERSION			_IOWR('b', 9, struct binder_version)
94
95/*
96 * NOTE: Two special error codes you should check for when calling
97 * in to the driver are:
98 *
99 * EINTR -- The operation has been interupted.  This should be
100 * handled by retrying the ioctl() until a different error code
101 * is returned.
102 *
103 * ECONNREFUSED -- The driver is no longer accepting operations
104 * from your process.  That is, the process is being destroyed.
105 * You should handle this by exiting from your process.  Note
106 * that once this error code is returned, all further calls to
107 * the driver from any thread will return this same code.
108 */
109
110enum transaction_flags {
111	TF_ONE_WAY	= 0x01,	/* this is a one-way call: async, no return */
112	TF_ROOT_OBJECT	= 0x04,	/* contents are the component's root object */
113	TF_STATUS_CODE	= 0x08,	/* contents are a 32-bit status code */
114	TF_ACCEPT_FDS	= 0x10,	/* allow replies with file descriptors */
115};
116
117struct binder_transaction_data {
118	/* The first two are only used for bcTRANSACTION and brTRANSACTION,
119	 * identifying the target and contents of the transaction.
120	 */
121	union {
122		size_t	handle;	/* target descriptor of command transaction */
123		void	*ptr;	/* target descriptor of return transaction */
124	} target;
125	void		*cookie;	/* target object cookie */
126	unsigned int	code;		/* transaction command */
127
128	/* General information about the transaction. */
129	unsigned int	flags;
130	pid_t		sender_pid;
131	uid_t		sender_euid;
132	size_t		data_size;	/* number of bytes of data */
133	size_t		offsets_size;	/* number of bytes of offsets */
134
135	/* If this transaction is inline, the data immediately
136	 * follows here; otherwise, it ends with a pointer to
137	 * the data buffer.
138	 */
139	union {
140		struct {
141			/* transaction data */
142			const void	*buffer;
143			/* offsets from buffer to flat_binder_object structs */
144			const void	*offsets;
145		} ptr;
146		uint8_t	buf[8];
147	} data;
148};
149
150struct binder_ptr_cookie {
151	void *ptr;
152	void *cookie;
153};
154
155struct binder_pri_desc {
156	int priority;
157	int desc;
158};
159
160struct binder_pri_ptr_cookie {
161	int priority;
162	void *ptr;
163	void *cookie;
164};
165
166enum BinderDriverReturnProtocol {
167	BR_ERROR = _IOR('r', 0, int),
168	/*
169	 * int: error code
170	 */
171
172	BR_OK = _IO('r', 1),
173	/* No parameters! */
174
175	BR_TRANSACTION = _IOR('r', 2, struct binder_transaction_data),
176	BR_REPLY = _IOR('r', 3, struct binder_transaction_data),
177	/*
178	 * binder_transaction_data: the received command.
179	 */
180
181	BR_ACQUIRE_RESULT = _IOR('r', 4, int),
182	/*
183	 * not currently supported
184	 * int: 0 if the last bcATTEMPT_ACQUIRE was not successful.
185	 * Else the remote object has acquired a primary reference.
186	 */
187
188	BR_DEAD_REPLY = _IO('r', 5),
189	/*
190	 * The target of the last transaction (either a bcTRANSACTION or
191	 * a bcATTEMPT_ACQUIRE) is no longer with us.  No parameters.
192	 */
193
194	BR_TRANSACTION_COMPLETE = _IO('r', 6),
195	/*
196	 * No parameters... always refers to the last transaction requested
197	 * (including replies).  Note that this will be sent even for
198	 * asynchronous transactions.
199	 */
200
201	BR_INCREFS = _IOR('r', 7, struct binder_ptr_cookie),
202	BR_ACQUIRE = _IOR('r', 8, struct binder_ptr_cookie),
203	BR_RELEASE = _IOR('r', 9, struct binder_ptr_cookie),
204	BR_DECREFS = _IOR('r', 10, struct binder_ptr_cookie),
205	/*
206	 * void *:	ptr to binder
207	 * void *: cookie for binder
208	 */
209
210	BR_ATTEMPT_ACQUIRE = _IOR('r', 11, struct binder_pri_ptr_cookie),
211	/*
212	 * not currently supported
213	 * int:	priority
214	 * void *: ptr to binder
215	 * void *: cookie for binder
216	 */
217
218	BR_NOOP = _IO('r', 12),
219	/*
220	 * No parameters.  Do nothing and examine the next command.  It exists
221	 * primarily so that we can replace it with a BR_SPAWN_LOOPER command.
222	 */
223
224	BR_SPAWN_LOOPER = _IO('r', 13),
225	/*
226	 * No parameters.  The driver has determined that a process has no
227	 * threads waiting to service incomming transactions.  When a process
228	 * receives this command, it must spawn a new service thread and
229	 * register it via bcENTER_LOOPER.
230	 */
231
232	BR_FINISHED = _IO('r', 14),
233	/*
234	 * not currently supported
235	 * stop threadpool thread
236	 */
237
238	BR_DEAD_BINDER = _IOR('r', 15, void *),
239	/*
240	 * void *: cookie
241	 */
242	BR_CLEAR_DEATH_NOTIFICATION_DONE = _IOR('r', 16, void *),
243	/*
244	 * void *: cookie
245	 */
246
247	BR_FAILED_REPLY = _IO('r', 17),
248	/*
249	 * The the last transaction (either a bcTRANSACTION or
250	 * a bcATTEMPT_ACQUIRE) failed (e.g. out of memory).  No parameters.
251	 */
252};
253
254enum BinderDriverCommandProtocol {
255	BC_TRANSACTION = _IOW('c', 0, struct binder_transaction_data),
256	BC_REPLY = _IOW('c', 1, struct binder_transaction_data),
257	/*
258	 * binder_transaction_data: the sent command.
259	 */
260
261	BC_ACQUIRE_RESULT = _IOW('c', 2, int),
262	/*
263	 * not currently supported
264	 * int:  0 if the last BR_ATTEMPT_ACQUIRE was not successful.
265	 * Else you have acquired a primary reference on the object.
266	 */
267
268	BC_FREE_BUFFER = _IOW('c', 3, int),
269	/*
270	 * void *: ptr to transaction data received on a read
271	 */
272
273	BC_INCREFS = _IOW('c', 4, int),
274	BC_ACQUIRE = _IOW('c', 5, int),
275	BC_RELEASE = _IOW('c', 6, int),
276	BC_DECREFS = _IOW('c', 7, int),
277	/*
278	 * int:	descriptor
279	 */
280
281	BC_INCREFS_DONE = _IOW('c', 8, struct binder_ptr_cookie),
282	BC_ACQUIRE_DONE = _IOW('c', 9, struct binder_ptr_cookie),
283	/*
284	 * void *: ptr to binder
285	 * void *: cookie for binder
286	 */
287
288	BC_ATTEMPT_ACQUIRE = _IOW('c', 10, struct binder_pri_desc),
289	/*
290	 * not currently supported
291	 * int: priority
292	 * int: descriptor
293	 */
294
295	BC_REGISTER_LOOPER = _IO('c', 11),
296	/*
297	 * No parameters.
298	 * Register a spawned looper thread with the device.
299	 */
300
301	BC_ENTER_LOOPER = _IO('c', 12),
302	BC_EXIT_LOOPER = _IO('c', 13),
303	/*
304	 * No parameters.
305	 * These two commands are sent as an application-level thread
306	 * enters and exits the binder loop, respectively.  They are
307	 * used so the binder can have an accurate count of the number
308	 * of looping threads it has available.
309	 */
310
311	BC_REQUEST_DEATH_NOTIFICATION = _IOW('c', 14, struct binder_ptr_cookie),
312	/*
313	 * void *: ptr to binder
314	 * void *: cookie
315	 */
316
317	BC_CLEAR_DEATH_NOTIFICATION = _IOW('c', 15, struct binder_ptr_cookie),
318	/*
319	 * void *: ptr to binder
320	 * void *: cookie
321	 */
322
323	BC_DEAD_BINDER_DONE = _IOW('c', 16, void *),
324	/*
325	 * void *: cookie
326	 */
327};
328
329#endif /* _LINUX_BINDER_H */
330
331