1/*
2 * Copyright (c) 2000-2007 Apple Inc. All rights reserved.
3 *
4 * @APPLE_OSREFERENCE_LICENSE_HEADER_START@
5 *
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7 * as defined in and that are subject to the Apple Public Source License
8 * Version 2.0 (the 'License'). You may not use this file except in
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14 *
15 * Please obtain a copy of the License at
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27 */
28/*
29 * @OSF_COPYRIGHT@
30 */
31/*
32 * Mach Operating System
33 * Copyright (c) 1991,1990,1989 Carnegie Mellon University
34 * All Rights Reserved.
35 *
36 * Permission to use, copy, modify and distribute this software and its
37 * documentation is hereby granted, provided that both the copyright
38 * notice and this permission notice appear in all copies of the
39 * software, derivative works or modified versions, and any portions
40 * thereof, and that both notices appear in supporting documentation.
41 *
42 * CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS"
43 * CONDITION.  CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND FOR
44 * ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE.
45 *
46 * Carnegie Mellon requests users of this software to return to
47 *
48 *  Software Distribution Coordinator  or  Software.Distribution@CS.CMU.EDU
49 *  School of Computer Science
50 *  Carnegie Mellon University
51 *  Pittsburgh PA 15213-3890
52 *
53 * any improvements or extensions that they make and grant Carnegie Mellon
54 * the rights to redistribute these changes.
55 */
56/*
57 * NOTICE: This file was modified by McAfee Research in 2004 to introduce
58 * support for mandatory and extensible security protections.  This notice
59 * is included in support of clause 2.2 (b) of the Apple Public License,
60 * Version 2.0.
61 */
62/*
63 */
64/*
65 *	File:	ipc/ipc_object.h
66 *	Author:	Rich Draves
67 *	Date:	1989
68 *
69 *	Definitions for IPC objects, for which tasks have capabilities.
70 */
71
72#ifndef	_IPC_IPC_OBJECT_H_
73#define _IPC_IPC_OBJECT_H_
74
75#include <mach_rt.h>
76#include <mach_kdb.h>
77
78#include <mach/kern_return.h>
79#include <mach/message.h>
80#include <kern/lock.h>
81#include <kern/macro_help.h>
82#include <kern/zalloc.h>
83#include <ipc/ipc_types.h>
84
85typedef natural_t ipc_object_refs_t;	/* for ipc/ipc_object.h		*/
86typedef natural_t ipc_object_bits_t;
87typedef natural_t ipc_object_type_t;
88
89/*
90 * There is no lock in the ipc_object; it is in the enclosing kernel
91 * data structure (rpc_common_data) used by both ipc_port and ipc_pset.
92 * The ipc_object is used to both tag and reference count these two data
93 * structures, and (Noto Bene!) pointers to either of these or the
94 * ipc_object at the head of these are freely cast back and forth; hence
95 * the ipc_object MUST BE FIRST in the ipc_common_data.
96 *
97 * If the RPC implementation enabled user-mode code to use kernel-level
98 * data structures (as ours used to), this peculiar structuring would
99 * avoid having anything in user code depend on the kernel configuration
100 * (with which lock size varies).
101 */
102struct ipc_object {
103	ipc_object_refs_t io_references;
104	ipc_object_bits_t io_bits;
105	mach_port_name_t  io_receiver_name;
106	decl_mutex_data(,	io_lock_data)
107};
108
109/*
110 * Legacy defines.  Should use IPC_OBJECT_NULL, etc...
111 */
112#define	IO_NULL			((ipc_object_t) 0)
113#define	IO_DEAD			((ipc_object_t) -1)
114#define	IO_VALID(io)		(((io) != IO_NULL) && ((io) != IO_DEAD))
115
116/*
117 *	IPC steals the high-order bits from the kotype to use
118 *	for its own purposes.  This allows IPC to record facts
119 *	about ports that aren't otherwise obvious from the
120 *	existing port fields.  In particular, IPC can optionally
121 *	mark a port for no more senders detection.  Any change
122 *	to IO_BITS_PORT_INFO must be coordinated with bitfield
123 *	definitions in ipc_port.h.
124 */
125#define	IO_BITS_PORT_INFO	0x0000f000	/* stupid port tricks */
126#define	IO_BITS_KOTYPE		0x00000fff	/* used by the object */
127#define IO_BITS_OTYPE		0x7fff0000	/* determines a zone */
128#define	IO_BITS_ACTIVE		0x80000000	/* is object alive? */
129
130#define	io_active(io)		((io)->io_bits & IO_BITS_ACTIVE)
131
132#define	io_otype(io)		(((io)->io_bits & IO_BITS_OTYPE) >> 16)
133#define	io_kotype(io)		((io)->io_bits & IO_BITS_KOTYPE)
134
135#define	io_makebits(active, otype, kotype)	\
136	(((active) ? IO_BITS_ACTIVE : 0) | ((otype) << 16) | (kotype))
137
138/*
139 * Object types: ports, port sets, kernel-loaded ports
140 */
141#define	IOT_PORT		0
142#define IOT_PORT_SET		1
143#define IOT_NUMBER		2		/* number of types used */
144
145extern zone_t ipc_object_zones[IOT_NUMBER];
146
147#define	io_alloc(otype)		\
148		((ipc_object_t) zalloc(ipc_object_zones[(otype)]))
149
150#if MACH_ASSERT || CONFIG_MACF_MACH
151/*
152 *	Call the routine for io_free so that checking can be performed.
153 */
154extern void	io_free(
155			unsigned int	otype,
156			ipc_object_t	object);
157
158#else	/* MACH_ASSERT || MAC_MACH */
159#define io_free(otype, io)  \
160	zfree(ipc_object_zones[(otype)], (io))
161#endif	/* MACH_ASSERT || MAC_MACH */
162
163/*
164 * Here we depend on the ipc_object being first within the ipc_common_data,
165 * which is first within the rpc_common_data, which in turn must be first
166 * within any kernel data structure needing to lock an ipc_object
167 * (ipc_port and ipc_pset).
168 */
169#define io_lock_init(io) \
170	mutex_init(&(io)->io_lock_data, 0)
171#define	io_lock(io) \
172	mutex_lock(&(io)->io_lock_data)
173#define	io_lock_try(io) \
174	mutex_try(&(io)->io_lock_data)
175#define	io_unlock(io) \
176	mutex_unlock(&(io)->io_lock_data)
177
178#define _VOLATILE_ volatile
179
180#define io_check_unlock(io) 						\
181MACRO_BEGIN								\
182	_VOLATILE_ ipc_object_refs_t _refs = (io)->io_references;	\
183									\
184	io_unlock(io);							\
185	if (_refs == 0)							\
186		io_free(io_otype(io), io);				\
187MACRO_END
188
189/* Sanity check the ref count.  If it is 0, we may be doubly zfreeing.
190 * If it is larger than max int, it has been corrupted, probably by being
191 * modified into an address (this is architecture dependent, but it's
192 * safe to assume there cannot really be max int references).
193 *
194 * NOTE: The 0 test alone will not catch double zfreeing of ipc_port
195 * structs, because the io_references field is the first word of the struct,
196 * and zfree modifies that to point to the next free zone element.
197 */
198#define IO_MAX_REFERENCES						\
199	(unsigned)(~0 ^ (1 << (sizeof(int)*BYTE_SIZE - 1)))
200
201#define	io_reference(io)						\
202MACRO_BEGIN								\
203	assert((io)->io_references < IO_MAX_REFERENCES);		\
204	(io)->io_references++;						\
205MACRO_END
206
207#define	io_release(io)							\
208MACRO_BEGIN								\
209	assert((io)->io_references > 0 &&				\
210		    (io)->io_references <= IO_MAX_REFERENCES);		\
211	(io)->io_references--;						\
212MACRO_END
213
214/*
215 * Retrieve a label for use in a kernel call that takes a security
216 * label as a parameter. If necessary, io_getlabel acquires internal
217 * (not io_lock) locks, and io_unlocklabel releases them.
218 */
219
220struct label;
221extern struct label *io_getlabel (ipc_object_t obj);
222#define io_unlocklabel(obj)
223
224/*
225 * Exported interfaces
226 */
227
228/* Take a reference to an object */
229extern void ipc_object_reference(
230	ipc_object_t	object);
231
232/* Release a reference to an object */
233extern void ipc_object_release(
234	ipc_object_t	object);
235
236/* Look up an object in a space */
237extern kern_return_t ipc_object_translate(
238	ipc_space_t		space,
239	mach_port_name_t	name,
240	mach_port_right_t	right,
241	ipc_object_t		*objectp);
242
243/* Look up two objects in a space, locking them in the order described */
244extern kern_return_t ipc_object_translate_two(
245	ipc_space_t		space,
246	mach_port_name_t	name1,
247	mach_port_right_t	right1,
248	ipc_object_t		*objectp1,
249	mach_port_name_t	name2,
250	mach_port_right_t	right2,
251	ipc_object_t		*objectp2);
252
253/* Allocate a dead-name entry */
254extern kern_return_t
255ipc_object_alloc_dead(
256	ipc_space_t		space,
257	mach_port_name_t 	*namep);
258
259/*  Allocate a dead-name entry, with a specific name */
260extern kern_return_t ipc_object_alloc_dead_name(
261	ipc_space_t		space,
262	mach_port_name_t	name);
263
264/* Allocate an object */
265extern kern_return_t ipc_object_alloc(
266	ipc_space_t		space,
267	ipc_object_type_t	otype,
268	mach_port_type_t	type,
269	mach_port_urefs_t	urefs,
270	mach_port_name_t	*namep,
271	ipc_object_t		*objectp);
272
273/* Allocate an object, with a specific name */
274extern kern_return_t ipc_object_alloc_name(
275	ipc_space_t		space,
276	ipc_object_type_t	otype,
277	mach_port_type_t	type,
278	mach_port_urefs_t	urefs,
279	mach_port_name_t	name,
280	ipc_object_t		*objectp);
281
282/* Convert a send type name to a received type name */
283extern mach_msg_type_name_t ipc_object_copyin_type(
284	mach_msg_type_name_t	msgt_name);
285
286/* Copyin a capability from a space */
287extern kern_return_t ipc_object_copyin(
288	ipc_space_t		space,
289	mach_port_name_t	name,
290	mach_msg_type_name_t	msgt_name,
291	ipc_object_t		*objectp);
292
293/* Copyin a naked capability from the kernel */
294extern void ipc_object_copyin_from_kernel(
295	ipc_object_t		object,
296	mach_msg_type_name_t	msgt_name);
297
298/* Destroy a naked capability */
299extern void ipc_object_destroy(
300	ipc_object_t		object,
301	mach_msg_type_name_t	msgt_name);
302
303/* Copyout a capability, placing it into a space */
304extern kern_return_t ipc_object_copyout(
305	ipc_space_t		space,
306	ipc_object_t		object,
307	mach_msg_type_name_t	msgt_name,
308	boolean_t		overflow,
309	mach_port_name_t	*namep);
310
311/* Copyout a capability with a name, placing it into a space */
312extern kern_return_t ipc_object_copyout_name(
313	ipc_space_t		space,
314	ipc_object_t		object,
315	mach_msg_type_name_t	msgt_name,
316	boolean_t		overflow,
317	mach_port_name_t	name);
318
319/* Translate/consume the destination right of a message */
320extern void ipc_object_copyout_dest(
321	ipc_space_t		space,
322	ipc_object_t		object,
323	mach_msg_type_name_t	msgt_name,
324	mach_port_name_t	*namep);
325
326/* Rename an entry in a space */
327extern kern_return_t ipc_object_rename(
328	ipc_space_t		space,
329	mach_port_name_t	oname,
330	mach_port_name_t	nname);
331
332#if	MACH_KDB
333/* Pretty-print an ipc object */
334
335extern void ipc_object_print(
336	ipc_object_t	object);
337
338#endif	/* MACH_KDB */
339
340#endif	/* _IPC_IPC_OBJECT_H_ */
341