1/*
2 * Copyright (c) 2000-2016 Apple Computer, 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
8 * Version 2.0 (the 'License'). You may not use this file except in
9 * compliance with the License. The rights granted to you under the License
10 * may not be used to create, or enable the creation or redistribution of,
11 * unlawful or unlicensed copies of an Apple operating system, or to
12 * circumvent, violate, or enable the circumvention or violation of, any
13 * terms of an Apple operating system software license agreement.
14 *
15 * Please obtain a copy of the License at
16 * http://www.opensource.apple.com/apsl/ and read it before using this file.
17 *
18 * The Original Code and all software distributed under the License are
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20 * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
21 * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
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23 * Please see the License for the specific language governing rights and
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25 *
26 * @APPLE_OSREFERENCE_LICENSE_HEADER_END@
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_space.h
66 * Author: Rich Draves
67 * Date: 1989
68 *
69 * Definitions for IPC spaces of capabilities.
70 */
71
72#ifndef _IPC_IPC_SPACE_H_
73#define _IPC_IPC_SPACE_H_
74
75
76#include <prng/random.h>
77#include <mach/mach_types.h>
78#include <mach/boolean.h>
79#include <mach/kern_return.h>
80#include <mach/vm_types.h>
81
82#include <sys/appleapiopts.h>
83
84#ifdef __APPLE_API_PRIVATE
85#ifdef MACH_KERNEL_PRIVATE
86#include <kern/macro_help.h>
87#include <kern/kern_types.h>
88#include <kern/locks.h>
89#include <kern/task.h>
90#include <kern/zalloc.h>
91#include <ipc/ipc_entry.h>
92#include <ipc/ipc_types.h>
93
94#include <libkern/OSAtomic.h>
95
96/*
97 * Every task has a space of IPC capabilities.
98 * IPC operations like send and receive use this space.
99 * IPC kernel calls manipulate the space of the target task.
100 *
101 * Every space has a non-NULL is_table with is_table_size entries.
102 *
103 * Only one thread can be growing the space at a time. Others
104 * that need it grown wait for the first. We do almost all the
105 * work with the space unlocked, so lookups proceed pretty much
106 * unaffected while the grow operation is underway.
107 */
108
109typedef natural_t ipc_space_refs_t;
110#define IS_REFS_MAX 0x0fffffff
111#define IS_INACTIVE 0x40000000 /* space is inactive */
112#define IS_GROWING 0x20000000 /* space is growing */
113#define IS_ENTROPY_CNT 1 /* per-space entropy pool size */
114
115struct ipc_space {
116 lck_spin_t is_lock_data;
117 ipc_space_refs_t is_bits; /* holds refs, active, growing */
118 ipc_entry_num_t is_table_size; /* current size of table */
119 ipc_entry_num_t is_table_free; /* count of free elements */
120 ipc_entry_t is_table; /* an array of entries */
121 task_t is_task; /* associated task */
122 struct ipc_table_size *is_table_next; /* info for larger table */
123 ipc_entry_num_t is_low_mod; /* lowest modified entry during growth */
124 ipc_entry_num_t is_high_mod; /* highest modified entry during growth */
125 struct bool_gen bool_gen; /* state for boolean RNG */
126 unsigned int is_entropy[IS_ENTROPY_CNT]; /* pool of entropy taken from RNG */
127 int is_node_id; /* HOST_LOCAL_NODE, or remote node if proxy space */
128};
129
130#define IS_NULL ((ipc_space_t) 0)
131#define IS_INSPECT_NULL ((ipc_space_inspect_t) 0)
132
133#define is_active(is) (((is)->is_bits & IS_INACTIVE) != IS_INACTIVE)
134
135static inline void
136is_mark_inactive(ipc_space_t is)
137{
138 assert(is_active(is));
139 OSBitOrAtomic(IS_INACTIVE, &is->is_bits);
140}
141
142#define is_growing(is) (((is)->is_bits & IS_GROWING) == IS_GROWING)
143
144static inline void
145is_start_growing(ipc_space_t is)
146{
147 assert(!is_growing(is));
148 OSBitOrAtomic(IS_GROWING, &is->is_bits);
149}
150
151static inline void
152is_done_growing(ipc_space_t is)
153{
154 assert(is_growing(is));
155 OSBitAndAtomic(~IS_GROWING, &is->is_bits);
156}
157
158extern zone_t ipc_space_zone;
159
160#define is_alloc() ((ipc_space_t) zalloc(ipc_space_zone))
161#define is_free(is) zfree(ipc_space_zone, (is))
162
163extern ipc_space_t ipc_space_kernel;
164extern ipc_space_t ipc_space_reply;
165#if DIPC
166extern ipc_space_t ipc_space_remote;
167#endif /* DIPC */
168#if DIPC
169extern ipc_space_t default_pager_space;
170#endif /* DIPC */
171
172extern lck_grp_t ipc_lck_grp;
173extern lck_attr_t ipc_lck_attr;
174
175#define is_lock_init(is) lck_spin_init(&(is)->is_lock_data, &ipc_lck_grp, &ipc_lck_attr)
176#define is_lock_destroy(is) lck_spin_destroy(&(is)->is_lock_data, &ipc_lck_grp)
177
178#define is_read_lock(is) lck_spin_lock(&(is)->is_lock_data)
179#define is_read_unlock(is) lck_spin_unlock(&(is)->is_lock_data)
180#define is_read_sleep(is) lck_spin_sleep(&(is)->is_lock_data, \
181 LCK_SLEEP_DEFAULT, \
182 (event_t)(is), \
183 THREAD_UNINT)
184
185#define is_write_lock(is) lck_spin_lock(&(is)->is_lock_data)
186#define is_write_lock_try(is) lck_spin_try_lock(&(is)->is_lock_data)
187#define is_write_unlock(is) lck_spin_unlock(&(is)->is_lock_data)
188#define is_write_sleep(is) lck_spin_sleep(&(is)->is_lock_data, \
189 LCK_SLEEP_DEFAULT, \
190 (event_t)(is), \
191 THREAD_UNINT)
192
193#define is_refs(is) ((is)->is_bits & IS_REFS_MAX)
194
195static inline void
196is_reference(ipc_space_t is)
197{
198 assert(is_refs(is) > 0 && is_refs(is) < IS_REFS_MAX);
199 OSIncrementAtomic(&(is->is_bits));
200}
201
202
203static inline void
204is_release(ipc_space_t is) {
205 assert(is_refs(is) > 0);
206
207 /* If we just removed the last reference count */
208 if ( 1 == (OSDecrementAtomic(&(is->is_bits)) & IS_REFS_MAX)) {
209 assert(!is_active(is));
210 is_lock_destroy(is);
211 is_free(is);
212 }
213}
214
215#define current_space_fast() (current_task_fast()->itk_space)
216#define current_space() (current_space_fast())
217
218/* Create a special IPC space */
219extern kern_return_t ipc_space_create_special(
220 ipc_space_t *spacep);
221
222/* Create a new IPC space */
223extern kern_return_t ipc_space_create(
224 ipc_table_size_t initial,
225 ipc_space_t *spacep);
226
227/* Mark a space as dead and cleans up the entries*/
228extern void ipc_space_terminate(
229 ipc_space_t space);
230
231/* Clean up the entries - but leave the space alive */
232extern void ipc_space_clean(
233 ipc_space_t space);
234
235/* Permute the order of a range within an IPC space */
236extern void ipc_space_rand_freelist(
237 ipc_space_t space,
238 ipc_entry_t table,
239 mach_port_index_t bottom,
240 mach_port_index_t top);
241
242/* Generate a new gencount rollover point from a space's entropy pool */
243extern ipc_entry_bits_t ipc_space_get_rollpoint(ipc_space_t space);
244#endif /* MACH_KERNEL_PRIVATE */
245#endif /* __APPLE_API_PRIVATE */
246
247#ifdef __APPLE_API_UNSTABLE
248#ifndef MACH_KERNEL_PRIVATE
249
250extern ipc_space_t current_space(void);
251
252#endif /* !MACH_KERNEL_PRIVATE */
253#endif /* __APPLE_API_UNSTABLE */
254
255/* Take a reference on a space */
256extern void ipc_space_reference(
257 ipc_space_t space);
258
259/* Realase a reference on a space */
260extern void ipc_space_release(
261 ipc_space_t space);
262
263#endif /* _IPC_IPC_SPACE_H_ */
264