xref: /xnu-10002.61.3/osfmk/ipc/ipc_object.h (revision 0f4c859e951fba394238ab619495c4e1d54d0f34)
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31 /*
32  * Mach Operating System
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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 <os/atomic_private.h>
76 #include <mach/kern_return.h>
77 #include <mach/message.h>
78 #include <kern/locks.h>
79 #include <kern/macro_help.h>
80 #include <kern/assert.h>
81 #include <kern/zalloc.h>
82 #include <ipc/ipc_types.h>
83 #include <libkern/OSAtomic.h>
84 
85 __BEGIN_DECLS __ASSUME_PTR_ABI_SINGLE_BEGIN
86 #pragma GCC visibility push(hidden)
87 
88 typedef natural_t ipc_object_refs_t;    /* for ipc/ipc_object.h		*/
89 typedef natural_t ipc_object_bits_t;
90 typedef natural_t ipc_object_type_t;
91 
92 __options_closed_decl(ipc_object_copyout_flags_t, uint32_t, {
93 	IPC_OBJECT_COPYOUT_FLAGS_NONE                 = 0x0,
94 	IPC_OBJECT_COPYOUT_FLAGS_PINNED               = 0x1,
95 	IPC_OBJECT_COPYOUT_FLAGS_NO_LABEL_CHECK       = 0x2,
96 });
97 
98 __options_closed_decl(ipc_object_copyin_flags_t, uint16_t, {
99 	IPC_OBJECT_COPYIN_FLAGS_NONE                          = 0x0,
100 	IPC_OBJECT_COPYIN_FLAGS_ALLOW_IMMOVABLE_SEND          = 0x1, /* Dest port contains an immovable send right */
101 	IPC_OBJECT_COPYIN_FLAGS_ALLOW_DEAD_SEND_ONCE          = 0x2,
102 	IPC_OBJECT_COPYIN_FLAGS_DEADOK                        = 0x4,
103 	IPC_OBJECT_COPYIN_FLAGS_ALLOW_REPLY_MAKE_SEND_ONCE    = 0x8,  /* Port is a reply port. */
104 	IPC_OBJECT_COPYIN_FLAGS_ALLOW_REPLY_MOVE_SEND_ONCE    = 0x10, /* Port is a reply port. */
105 	IPC_OBJECT_COPYIN_FLAGS_ALLOW_IMMOVABLE_RECEIVE       = 0x20,
106 	IPC_OBJECT_COPYIN_FLAGS_ALLOW_CONN_IMMOVABLE_RECEIVE  = 0x40, /* Port is a libxpc connection port. */
107 });
108 
109 /*
110  * The ipc_object is used to both tag and reference count these two data
111  * structures, and (Noto Bene!) pointers to either of these or the
112  * ipc_object at the head of these are freely cast back and forth; hence
113  * the ipc_object MUST BE FIRST in the ipc_common_data.
114  *
115  * If the RPC implementation enabled user-mode code to use kernel-level
116  * data structures (as ours used to), this peculiar structuring would
117  * avoid having anything in user code depend on the kernel configuration
118  * (with which lock size varies).
119  */
120 struct ipc_object {
121 	ipc_object_bits_t _Atomic io_bits;
122 	ipc_object_refs_t _Atomic io_references;
123 } __attribute__((aligned(8)));
124 
125 /*
126  * Legacy defines.  Should use IPC_OBJECT_NULL, etc...
127  */
128 #define IO_NULL                 ((ipc_object_t) 0)
129 #define IO_DEAD                 ((ipc_object_t) ~0UL)
130 #define IO_VALID(io)            (((io) != IO_NULL) && ((io) != IO_DEAD))
131 
132 /*
133  *	IPC steals the high-order bits from the kotype to use
134  *	for its own purposes.  This allows IPC to record facts
135  *	about ports that aren't otherwise obvious from the
136  *	existing port fields.  In particular, IPC can optionally
137  *	mark a port for no more senders detection.  Any change
138  *	to IO_BITS_PORT_INFO must be coordinated with bitfield
139  *	definitions in ipc_port.h.
140  *
141  *	Note that the io_bits can be read atomically without
142  *	holding the object lock (for example to read the kobject type).
143  *	As such updates to this field need to use the io_bits_or()
144  *	or io_bits_andnot() functions.
145  */
146 #define IO_BITS_PORT_INFO       0x0000f000      /* stupid port tricks */
147 #define IO_BITS_KOTYPE          0x000003ff      /* used by the object */
148 #define IO_BITS_KOLABEL         0x00000400      /* The kobject has a label */
149 #define IO_BITS_OTYPE           0x7fff0000      /* determines a zone */
150 #define IO_BITS_ACTIVE          0x80000000      /* is object alive? */
151 
152 #define io_bits(io)             atomic_load_explicit(&(io)->io_bits, memory_order_relaxed)
153 
154 static inline void
io_bits_or(ipc_object_t io,ipc_object_bits_t bits)155 io_bits_or(ipc_object_t io, ipc_object_bits_t bits)
156 {
157 	/*
158 	 * prevent any possibility for the compiler to tear the update,
159 	 * the update still requires the io lock to be held.
160 	 */
161 	os_atomic_store(&io->io_bits, io_bits(io) | bits, relaxed);
162 }
163 
164 static inline void
io_bits_andnot(ipc_object_t io,ipc_object_bits_t bits)165 io_bits_andnot(ipc_object_t io, ipc_object_bits_t bits)
166 {
167 	/*
168 	 * prevent any possibility for the compiler to tear the update,
169 	 * the update still requires the io lock to be held.
170 	 */
171 	os_atomic_store(&io->io_bits, io_bits(io) & ~bits, relaxed);
172 }
173 
174 #define io_active(io)           ((io_bits(io) & IO_BITS_ACTIVE) != 0)
175 
176 #define io_otype(io)            ((io_bits(io) & IO_BITS_OTYPE) >> 16)
177 #define io_kotype(io)           (io_bits(io) & IO_BITS_KOTYPE)
178 #define io_is_kobject(io)       (io_kotype(io) != 0)
179 #define io_is_kolabeled(io)     ((io_bits(io) & IO_BITS_KOLABEL) != 0)
180 #define io_makebits(otype)      (IO_BITS_ACTIVE | ((otype) << 16))
181 
182 /*
183  * Object types: ports, port sets, kernel-loaded ports
184  */
185 #define IOT_PORT                0
186 #define IOT_PORT_SET            1
187 #define IOT_NUMBER              2               /* number of types used */
188 
189 extern zone_t __single ipc_object_zones[IOT_NUMBER];
190 
191 #define io_alloc(otype, flags) \
192 	zalloc_flags(ipc_object_zones[otype], flags)
193 
194 /*
195  * Here we depend on all ipc_objects being an ipc_wait_queue
196  */
197 #define io_waitq(io) \
198 	(&__container_of(io, struct ipc_object_waitq, iowq_object)->iowq_waitq)
199 #define io_from_waitq(waitq) \
200 	(&__container_of(waitq, struct ipc_object_waitq, iowq_waitq)->iowq_object)
201 
202 #define io_lock(io)          ipc_object_lock(io)
203 #define io_lock_try(io)      ipc_object_lock_try(io)
204 #define io_unlock(io)        ipc_object_unlock(io)
205 #define io_lock_held(io)     assert(waitq_held(io_waitq(io)))
206 #define io_lock_held_kdp(io) waitq_held(io_waitq(io))
207 #define io_lock_allow_invalid(io) ipc_object_lock_allow_invalid(io)
208 
209 #define io_reference(io)     ipc_object_reference(io)
210 #define io_release(io)       ipc_object_release(io)
211 #define io_release_safe(io)  ipc_object_release_safe(io)
212 #define io_release_live(io)  ipc_object_release_live(io)
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 
220 struct label;
221 extern struct label *io_getlabel(ipc_object_t obj);
222 #define io_unlocklabel(obj)
223 
224 /*
225  * Exported interfaces
226  */
227 
228 extern void ipc_object_lock(
229 	ipc_object_t    object);
230 
231 extern bool ipc_object_lock_allow_invalid(
232 	ipc_object_t    object) __result_use_check;
233 
234 extern bool ipc_object_lock_try(
235 	ipc_object_t    object);
236 
237 extern void ipc_object_unlock(
238 	ipc_object_t    object);
239 
240 extern void ipc_object_deallocate_register_queue(void);
241 
242 /* Take a reference to an object */
243 extern void ipc_object_reference(
244 	ipc_object_t    object);
245 
246 /* Release a reference to an object */
247 extern void ipc_object_release(
248 	ipc_object_t    object);
249 
250 extern void ipc_object_release_safe(
251 	ipc_object_t    object);
252 
253 /* Release a reference to an object that isn't the last one */
254 extern void ipc_object_release_live(
255 	ipc_object_t    object);
256 
257 /* Look up an object in a space */
258 extern kern_return_t ipc_object_translate(
259 	ipc_space_t             space,
260 	mach_port_name_t        name,
261 	mach_port_right_t       right,
262 	ipc_object_t            *objectp);
263 
264 /* Look up two objects in a space, locking them in the order described */
265 extern kern_return_t ipc_object_translate_two(
266 	ipc_space_t             space,
267 	mach_port_name_t        name1,
268 	mach_port_right_t       right1,
269 	ipc_object_t            *objectp1,
270 	mach_port_name_t        name2,
271 	mach_port_right_t       right2,
272 	ipc_object_t            *objectp2);
273 
274 /* Validate an object as belonging to the correct zone */
275 extern void ipc_object_validate(
276 	ipc_object_t object);
277 
278 /* Allocate a dead-name entry */
279 extern kern_return_t
280 ipc_object_alloc_dead(
281 	ipc_space_t             space,
282 	mach_port_name_t        *namep);
283 
284 /* Allocate an object */
285 extern kern_return_t ipc_object_alloc(
286 	ipc_space_t             space,
287 	ipc_object_type_t       otype,
288 	mach_port_type_t        type,
289 	mach_port_urefs_t       urefs,
290 	mach_port_name_t        *namep,
291 	ipc_object_t            *objectp);
292 
293 /* Allocate an object, with a specific name */
294 extern kern_return_t ipc_object_alloc_name(
295 	ipc_space_t             space,
296 	ipc_object_type_t       otype,
297 	mach_port_type_t        type,
298 	mach_port_urefs_t       urefs,
299 	mach_port_name_t        name,
300 	ipc_object_t            *objectp,
301 	void                    (^finish_init)(ipc_object_t object));
302 
303 /* Convert a send type name to a received type name */
304 extern mach_msg_type_name_t ipc_object_copyin_type(
305 	mach_msg_type_name_t    msgt_name);
306 
307 /* Copyin a capability from a space */
308 extern kern_return_t ipc_object_copyin(
309 	ipc_space_t             space,
310 	mach_port_name_t        name,
311 	mach_msg_type_name_t    msgt_name,
312 	ipc_object_t            *objectp,
313 	mach_port_context_t     context,
314 	mach_msg_guard_flags_t  *guard_flags,
315 	ipc_object_copyin_flags_t copyin_flags);
316 
317 /* Copyin a naked capability from the kernel */
318 extern void ipc_object_copyin_from_kernel(
319 	ipc_object_t            object,
320 	mach_msg_type_name_t    msgt_name);
321 
322 /* Destroy a naked capability */
323 extern void ipc_object_destroy(
324 	ipc_object_t            object,
325 	mach_msg_type_name_t    msgt_name);
326 
327 /* Destroy a naked destination capability */
328 extern void ipc_object_destroy_dest(
329 	ipc_object_t            object,
330 	mach_msg_type_name_t    msgt_name);
331 
332 /* Insert a send right into an object already in the current space */
333 extern kern_return_t ipc_object_insert_send_right(
334 	ipc_space_t             space,
335 	mach_port_name_t        name,
336 	mach_msg_type_name_t    msgt_name);
337 
338 /* Copyout a capability, placing it into a space */
339 extern kern_return_t ipc_object_copyout(
340 	ipc_space_t             space,
341 	ipc_object_t            object,
342 	mach_msg_type_name_t    msgt_name,
343 	ipc_object_copyout_flags_t flags,
344 	mach_port_context_t     *context,
345 	mach_msg_guard_flags_t  *guard_flags,
346 	mach_port_name_t        *namep);
347 
348 /* Copyout a capability with a name, placing it into a space */
349 extern kern_return_t ipc_object_copyout_name(
350 	ipc_space_t             space,
351 	ipc_object_t            object,
352 	mach_msg_type_name_t    msgt_name,
353 	mach_port_name_t        name);
354 
355 /* Translate/consume the destination right of a message */
356 extern void ipc_object_copyout_dest(
357 	ipc_space_t             space,
358 	ipc_object_t            object,
359 	mach_msg_type_name_t    msgt_name,
360 	mach_port_name_t        *namep);
361 
362 #pragma GCC visibility pop
363 __ASSUME_PTR_ABI_SINGLE_BEGIN __END_DECLS
364 
365 #endif  /* _IPC_IPC_OBJECT_H_ */
366