1/*
2 * Copyright (c) 2000-2007 Apple Inc. All rights reserved.
3 *
4 * @APPLE_OSREFERENCE_LICENSE_HEADER_START@
5 *
6 * This file contains Original Code and/or Modifications of Original Code
7 * as defined in and that are subject to the Apple Public Source License
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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
77#include <mach/kern_return.h>
78#include <mach/message.h>
79#include <kern/locks.h>
80#include <kern/macro_help.h>
81#include <kern/assert.h>
82#include <kern/zalloc.h>
83#include <ipc/ipc_types.h>
84#include <libkern/OSAtomic.h>
85
86typedef natural_t ipc_object_refs_t;	/* for ipc/ipc_object.h		*/
87typedef natural_t ipc_object_bits_t;
88typedef natural_t ipc_object_type_t;
89
90/*
91 * The ipc_object is used to both tag and reference count these two data
92 * structures, and (Noto Bene!) pointers to either of these or the
93 * ipc_object at the head of these are freely cast back and forth; hence
94 * the ipc_object MUST BE FIRST in the ipc_common_data.
95 *
96 * If the RPC implementation enabled user-mode code to use kernel-level
97 * data structures (as ours used to), this peculiar structuring would
98 * avoid having anything in user code depend on the kernel configuration
99 * (with which lock size varies).
100 */
101struct ipc_object {
102	ipc_object_bits_t io_bits;
103	ipc_object_refs_t io_references;
104	lck_spin_t	io_lock_data;
105};
106
107/*
108 * If another object type needs to participate in io_kotype()-based
109 * dispatching, it must include a stub structure as the first
110 * element
111 */
112struct ipc_object_header {
113	ipc_object_bits_t io_bits;
114#ifdef __LP64__
115	natural_t         io_padding; /* pad to natural boundary */
116#endif
117};
118
119/*
120 * Legacy defines.  Should use IPC_OBJECT_NULL, etc...
121 */
122#define	IO_NULL			((ipc_object_t) 0)
123#define	IO_DEAD			((ipc_object_t) ~0UL)
124#define	IO_VALID(io)		(((io) != IO_NULL) && ((io) != IO_DEAD))
125
126/*
127 *	IPC steals the high-order bits from the kotype to use
128 *	for its own purposes.  This allows IPC to record facts
129 *	about ports that aren't otherwise obvious from the
130 *	existing port fields.  In particular, IPC can optionally
131 *	mark a port for no more senders detection.  Any change
132 *	to IO_BITS_PORT_INFO must be coordinated with bitfield
133 *	definitions in ipc_port.h.
134 */
135#define	IO_BITS_PORT_INFO	0x0000f000	/* stupid port tricks */
136#define	IO_BITS_KOTYPE		0x00000fff	/* used by the object */
137#define IO_BITS_OTYPE		0x7fff0000	/* determines a zone */
138#define	IO_BITS_ACTIVE		0x80000000	/* is object alive? */
139
140#define	io_active(io)		(((io)->io_bits & IO_BITS_ACTIVE) != 0)
141
142#define	io_otype(io)		(((io)->io_bits & IO_BITS_OTYPE) >> 16)
143#define	io_kotype(io)		((io)->io_bits & IO_BITS_KOTYPE)
144
145#define	io_makebits(active, otype, kotype)	\
146	(((active) ? IO_BITS_ACTIVE : 0) | ((otype) << 16) | (kotype))
147
148/*
149 * Object types: ports, port sets, kernel-loaded ports
150 */
151#define	IOT_PORT		0
152#define IOT_PORT_SET		1
153#define IOT_NUMBER		2		/* number of types used */
154
155extern zone_t ipc_object_zones[IOT_NUMBER];
156
157#define	io_alloc(otype)		\
158		((ipc_object_t) zalloc(ipc_object_zones[(otype)]))
159
160extern void	io_free(
161			unsigned int	otype,
162			ipc_object_t	object);
163
164/*
165 * Here we depend on the ipc_object being first within the kernel struct
166 * (ipc_port and ipc_pset).
167 */
168#define io_lock_init(io) \
169	lck_spin_init(&(io)->io_lock_data, &ipc_lck_grp, &ipc_lck_attr)
170#define io_lock_destroy(io) \
171	lck_spin_destroy(&(io)->io_lock_data, &ipc_lck_grp)
172#define	io_lock(io) \
173	lck_spin_lock(&(io)->io_lock_data)
174#define	io_lock_try(io) \
175	lck_spin_try_lock(&(io)->io_lock_data)
176#define	io_unlock(io) \
177	lck_spin_unlock(&(io)->io_lock_data)
178
179#define _VOLATILE_ volatile
180
181/* Sanity check the ref count.  If it is 0, we may be doubly zfreeing.
182 * If it is larger than max int, it has been corrupted, probably by being
183 * modified into an address (this is architecture dependent, but it's
184 * safe to assume there cannot really be max int references).
185 *
186 * NOTE: The 0 test alone will not catch double zfreeing of ipc_port
187 * structs, because the io_references field is the first word of the struct,
188 * and zfree modifies that to point to the next free zone element.
189 */
190#define IO_MAX_REFERENCES						\
191	(unsigned)(~0 ^ (1 << (sizeof(int)*BYTE_SIZE - 1)))
192
193static inline void
194io_reference(ipc_object_t io) {
195	assert((io)->io_references > 0 &&
196	    (io)->io_references < IO_MAX_REFERENCES);
197	OSIncrementAtomic(&((io)->io_references));
198}
199
200
201static inline void
202io_release(ipc_object_t io) {
203	assert((io)->io_references > 0 &&
204	    (io)->io_references < IO_MAX_REFERENCES);
205        /* If we just removed the last reference count */
206	if ( 1 == OSDecrementAtomic(&((io)->io_references))) {
207		/* Free the object */
208		io_free(io_otype((io)), (io));
209	}
210}
211
212/*
213 * Retrieve a label for use in a kernel call that takes a security
214 * label as a parameter. If necessary, io_getlabel acquires internal
215 * (not io_lock) locks, and io_unlocklabel releases them.
216 */
217
218struct label;
219extern struct label *io_getlabel (ipc_object_t obj);
220#define io_unlocklabel(obj)
221
222/*
223 * Exported interfaces
224 */
225
226/* Take a reference to an object */
227extern void ipc_object_reference(
228	ipc_object_t	object);
229
230/* Release a reference to an object */
231extern void ipc_object_release(
232	ipc_object_t	object);
233
234/* Look up an object in a space */
235extern kern_return_t ipc_object_translate(
236	ipc_space_t		space,
237	mach_port_name_t	name,
238	mach_port_right_t	right,
239	ipc_object_t		*objectp);
240
241/* Look up two objects in a space, locking them in the order described */
242extern kern_return_t ipc_object_translate_two(
243	ipc_space_t		space,
244	mach_port_name_t	name1,
245	mach_port_right_t	right1,
246	ipc_object_t		*objectp1,
247	mach_port_name_t	name2,
248	mach_port_right_t	right2,
249	ipc_object_t		*objectp2);
250
251/* Allocate a dead-name entry */
252extern kern_return_t
253ipc_object_alloc_dead(
254	ipc_space_t		space,
255	mach_port_name_t 	*namep);
256
257/*  Allocate a dead-name entry, with a specific name */
258extern kern_return_t ipc_object_alloc_dead_name(
259	ipc_space_t		space,
260	mach_port_name_t	name);
261
262/* Allocate an object */
263extern kern_return_t ipc_object_alloc(
264	ipc_space_t		space,
265	ipc_object_type_t	otype,
266	mach_port_type_t	type,
267	mach_port_urefs_t	urefs,
268	mach_port_name_t	*namep,
269	ipc_object_t		*objectp);
270
271/* Allocate an object, with a specific name */
272extern kern_return_t ipc_object_alloc_name(
273	ipc_space_t		space,
274	ipc_object_type_t	otype,
275	mach_port_type_t	type,
276	mach_port_urefs_t	urefs,
277	mach_port_name_t	name,
278	ipc_object_t		*objectp);
279
280/* Convert a send type name to a received type name */
281extern mach_msg_type_name_t ipc_object_copyin_type(
282	mach_msg_type_name_t	msgt_name);
283
284/* Copyin a capability from a space */
285extern kern_return_t ipc_object_copyin(
286	ipc_space_t		space,
287	mach_port_name_t	name,
288	mach_msg_type_name_t	msgt_name,
289	ipc_object_t		*objectp);
290
291/* Copyin a naked capability from the kernel */
292extern void ipc_object_copyin_from_kernel(
293	ipc_object_t		object,
294	mach_msg_type_name_t	msgt_name);
295
296/* Destroy a naked capability */
297extern void ipc_object_destroy(
298	ipc_object_t		object,
299	mach_msg_type_name_t	msgt_name);
300
301/* Destroy a naked destination capability */
302extern void ipc_object_destroy_dest(
303	ipc_object_t		object,
304	mach_msg_type_name_t	msgt_name);
305
306/* Copyout a capability, placing it into a space */
307extern kern_return_t ipc_object_copyout(
308	ipc_space_t		space,
309	ipc_object_t		object,
310	mach_msg_type_name_t	msgt_name,
311	boolean_t		overflow,
312	mach_port_name_t	*namep);
313
314/* Copyout a capability with a name, placing it into a space */
315extern kern_return_t ipc_object_copyout_name(
316	ipc_space_t		space,
317	ipc_object_t		object,
318	mach_msg_type_name_t	msgt_name,
319	boolean_t		overflow,
320	mach_port_name_t	name);
321
322/* Translate/consume the destination right of a message */
323extern void ipc_object_copyout_dest(
324	ipc_space_t		space,
325	ipc_object_t		object,
326	mach_msg_type_name_t	msgt_name,
327	mach_port_name_t	*namep);
328
329/* Rename an entry in a space */
330extern kern_return_t ipc_object_rename(
331	ipc_space_t		space,
332	mach_port_name_t	oname,
333	mach_port_name_t	nname);
334
335#endif	/* _IPC_IPC_OBJECT_H_ */
336