xref: /xnu-8020.140.41/osfmk/ipc/ipc_voucher.h (revision 27b03b360a988dfd3dfdf34262bb0042026747cc)
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28 #ifndef _IPC_IPC_VOUCHER_H_
29 #define _IPC_IPC_VOUCHER_H_
30 
31 #include <mach/mach_types.h>
32 #include <mach/mach_voucher_types.h>
33 #include <mach/boolean.h>
34 #include <ipc/ipc_types.h>
35 #include <os/refcnt.h>
36 
37 #ifdef MACH_KERNEL_PRIVATE
38 
39 #include <kern/queue.h>
40 #include <kern/locks.h>
41 #include <kern/simple_lock.h>
42 #include <voucher/ipc_pthread_priority_types.h>
43 
44 /* locking */
45 extern lck_grp_t        ipc_lck_grp;
46 extern lck_attr_t       ipc_lck_attr;
47 
48 /* some shorthand for longer types */
49 typedef mach_voucher_attr_value_handle_t        iv_value_handle_t __kernel_ptr_semantics;
50 typedef mach_voucher_attr_value_reference_t     iv_value_refs_t;
51 
52 typedef natural_t               iv_index_t;
53 #define IV_UNUSED_VALINDEX      ((iv_index_t) 0)
54 #define IV_UNUSED_KEYINDEX      ((iv_index_t) ~0)
55 
56 typedef iv_index_t              *iv_entry_t;
57 #define IVE_NULL                ((iv_entry_t) 0)
58 
59 #define IV_ENTRIES_INLINE MACH_VOUCHER_ATTR_KEY_NUM_WELL_KNOWN
60 
61 /*
62  * IPC Voucher
63  *
64  * Vouchers are a reference counted immutable (once-created) set of
65  * indexes to particular resource manager attribute values
66  * (which themselves are reference counted).
67  */
68 struct ipc_voucher {
69 	iv_index_t              iv_hash;        /* checksum hash */
70 	iv_index_t              iv_sum;         /* checksum of values */
71 	os_refcnt_t             iv_refs;        /* reference count */
72 	iv_index_t              iv_table_size;  /* size of the voucher table */
73 	iv_index_t              iv_inline_table[IV_ENTRIES_INLINE];
74 	iv_entry_t              iv_table;       /* table of voucher attr entries */
75 	ipc_port_t              iv_port;        /* port representing the voucher */
76 	queue_chain_t           iv_hash_link;   /* link on hash chain */
77 };
78 
79 #define IV_NULL         IPC_VOUCHER_NULL
80 
81 
82 /*
83  * Voucher Attribute Cache Control Object
84  *
85  * This is where the Voucher system stores its caches/references to
86  * returned resource manager attribute values.  Each value only appears
87  * once in the table.  If a value is returned more than once by the
88  * resource manager, the voucher system will increase the reference
89  * on the previous value.
90  *
91  * The voucher itself contains one entry per key, that indexes into
92  * this table.
93  *
94  * A voucher that does not have an explicit index for a given key
95  * is assumed to have a reference on slot zero - which is where the
96  * voucher system stores the default value for the given attribute
97  * (specified at the time of resource manager registration).
98  *
99  * The ivace_releasing field limits the entry to a single concurrent
100  * return. Without it, a previous release's reply might still be
101  * working its way back to the voucher code, and a subsequent get-
102  * value could return the same value as was previously returned.  If
103  * the resource manager already knew that, it would return a failure
104  * on the return, and all is well.  We just treat the additional made
105  * references on the value as we normally would.  However, if the resource
106  * manager accepted the return, and the get-value response raced the
107  * release's reply, the newly made references will look like an extension
108  * of the old value's cache lifetime, rather than a new one.  Dropping
109  * that new lifetime's references to zero would result in a second
110  * release callback to the resource manager - this time with the wrong
111  * "made" reference count.  We avoid the race with this flag.
112  */
113 
114 struct ivac_entry_s {
115 	iv_value_handle_t       ivace_value;
116 	iv_value_refs_t         ivace_layered:1,     /* layered effective entry */
117 	    ivace_releasing:1,                       /* release in progress */
118 	    ivace_free:1,                            /* on freelist */
119 	    ivace_persist:1,                         /* Persist the entry, don't count made refs */
120 	    ivace_refs:28;                           /* reference count */
121 	union {
122 		iv_value_refs_t ivaceu_made;         /* made count (non-layered) */
123 		iv_index_t      ivaceu_layer;        /* next effective layer (layered) */
124 	} ivace_u;
125 	iv_index_t              ivace_next;          /* hash or freelist */
126 	iv_index_t              ivace_index;         /* hash head (independent) */
127 };
128 typedef struct ivac_entry_s       ivac_entry;
129 typedef ivac_entry              *ivac_entry_t;
130 
131 #define ivace_made              ivace_u.ivaceu_made
132 #define ivace_layer             ivace_u.ivaceu_layer
133 
134 #define IVACE_NULL              ((ivac_entry_t) 0);
135 
136 #define IVACE_REFS_MAX          ((1 << 28) - 1)
137 
138 #define IVAC_ENTRIES_MIN        512
139 #define IVAC_ENTRIES_MAX        524288
140 
141 struct ipc_voucher_attr_control {
142 	os_refcnt_t             ivac_refs;
143 	boolean_t               ivac_is_growing;        /* is the table being grown */
144 	ivac_entry_t            ivac_table;             /* table of voucher attr value entries */
145 	iv_index_t              ivac_table_size;        /* size of the attr value table */
146 	iv_index_t              ivac_init_table_size;   /* size of the attr value table */
147 	iv_index_t              ivac_freelist;          /* index of the first free element */
148 	ipc_port_t              ivac_port;              /* port for accessing the cache control  */
149 	lck_spin_t              ivac_lock_data;
150 	iv_index_t              ivac_key_index;         /* key index for this value */
151 };
152 typedef ipc_voucher_attr_control_t iv_attr_control_t;
153 
154 #define IVAC_NULL                  IPC_VOUCHER_ATTR_CONTROL_NULL
155 
156 extern ipc_voucher_attr_control_t  ivac_alloc(iv_index_t);
157 extern void ipc_voucher_receive_postprocessing(ipc_kmsg_t kmsg, mach_msg_option_t option);
158 extern void ipc_voucher_send_preprocessing(ipc_kmsg_t kmsg);
159 extern ipc_voucher_t ipc_voucher_get_default_voucher(void);
160 extern void mach_init_activity_id(void);
161 #if CONFIG_VOUCHER_DEPRECATED
162 extern kern_return_t ipc_get_pthpriority_from_kmsg_voucher(ipc_kmsg_t kmsg, ipc_pthread_priority_value_t *qos);
163 #endif /* CONFIG_VOUCHER_DEPRECATED */
164 
165 #define ivac_lock_init(ivac) \
166 	lck_spin_init(&(ivac)->ivac_lock_data, &ipc_lck_grp, &ipc_lck_attr)
167 #define ivac_lock_destroy(ivac) \
168 	lck_spin_destroy(&(ivac)->ivac_lock_data, &ipc_lck_grp)
169 #define ivac_lock(ivac) \
170 	lck_spin_lock_grp(&(ivac)->ivac_lock_data, &ipc_lck_grp)
171 #define ivac_lock_try(ivac) \
172 	lck_spin_try_lock_grp(&(ivac)->ivac_lock_data, &ipc_lck_grp)
173 #define ivac_unlock(ivac) \
174 	lck_spin_unlock(&(ivac)->ivac_lock_data)
175 #define ivac_sleep(ivac) lck_spin_sleep_grp(&(ivac)->ivac_lock_data,        \
176 	                                LCK_SLEEP_DEFAULT,              \
177 	                                (event_t)(ivac),                \
178 	                                THREAD_UNINT, &ipc_lck_grp)
179 #define ivac_wakeup(ivac) thread_wakeup((event_t)(ivac))
180 
181 extern void ivac_dealloc(ipc_voucher_attr_control_t ivac);
182 
183 static inline void
ivac_reference(ipc_voucher_attr_control_t ivac)184 ivac_reference(ipc_voucher_attr_control_t ivac)
185 {
186 	if (ivac == IVAC_NULL) {
187 		return;
188 	}
189 	os_ref_retain(&ivac->ivac_refs);
190 }
191 
192 static inline void
ivac_release(ipc_voucher_attr_control_t ivac)193 ivac_release(ipc_voucher_attr_control_t ivac)
194 {
195 	if (IVAC_NULL == ivac) {
196 		return;
197 	}
198 
199 	if (os_ref_release(&ivac->ivac_refs) == 0) {
200 		ivac_dealloc(ivac);
201 	}
202 }
203 
204 #define IVAM_NULL IPC_VOUCHER_ATTR_MANAGER_NULL
205 
206 /*
207  * IPC voucher Resource Manager table element
208  *
209  * Information Associated with a specific registration of
210  * a voucher resource manager.
211  *
212  * NOTE: For now, this table is indexed directly by the key.  In the future,
213  * it will have to be growable and sparse by key.  When that is implemented
214  * the index will be independent from the key (but there will be a hash to
215  * find the index by key).
216  */
217 typedef struct ipc_voucher_global_table_element {
218 	ipc_voucher_attr_manager_t      ivgte_manager;
219 	ipc_voucher_attr_control_t      ivgte_control;
220 	mach_voucher_attr_key_t         ivgte_key;
221 } ipc_voucher_global_table_element;
222 
223 typedef ipc_voucher_global_table_element *ipc_voucher_global_table_element_t;
224 
225 #endif /* MACH_KERNEL_PRIVATE */
226 
227 /*
228  * IPC voucher attribute recipe
229  *
230  * In-kernel recipe format with an ipc_voucher_t pointer for the previous
231  * voucher reference.
232  */
233 #pragma pack(1)
234 typedef struct ipc_voucher_attr_recipe_data {
235 	mach_voucher_attr_key_t                 key;
236 	mach_voucher_attr_recipe_command_t      command;
237 	ipc_voucher_t                           previous_voucher;
238 	mach_voucher_attr_content_size_t        content_size;
239 	uint8_t                                 content[];
240 } ipc_voucher_attr_recipe_data_t;
241 typedef ipc_voucher_attr_recipe_data_t *ipc_voucher_attr_recipe_t;
242 typedef mach_msg_type_number_t ipc_voucher_attr_recipe_size_t;
243 
244 typedef uint8_t *ipc_voucher_attr_raw_recipe_t;
245 typedef ipc_voucher_attr_raw_recipe_t ipc_voucher_attr_raw_recipe_array_t;
246 typedef mach_msg_type_number_t ipc_voucher_attr_raw_recipe_size_t;
247 typedef mach_msg_type_number_t ipc_voucher_attr_raw_recipe_array_size_t;
248 
249 #pragma pack()
250 
251 /*
252  * In-kernel Resource Manager Definition
253  *
254  * In-kernel resource managers are defined by a v-table like structure for
255  * the three callouts supported by a resource manager (and release function).
256  *
257  * There is a single in-kernel resource manager that represents all the
258  * outside kernel managers (and reflects the calls through MIG to user-space).
259  */
260 
261 typedef kern_return_t (*ipc_voucher_attr_manager_release_value_t)(ipc_voucher_attr_manager_t,
262     mach_voucher_attr_key_t,
263     mach_voucher_attr_value_handle_t,
264     mach_voucher_attr_value_reference_t);
265 
266 typedef kern_return_t (*ipc_voucher_attr_manager_get_value_t)(ipc_voucher_attr_manager_t,
267     mach_voucher_attr_key_t,
268     mach_voucher_attr_recipe_command_t,
269     mach_voucher_attr_value_handle_array_t,
270     mach_voucher_attr_value_handle_array_size_t,
271     mach_voucher_attr_content_t,
272     mach_voucher_attr_content_size_t,
273     mach_voucher_attr_value_handle_t *,
274     mach_voucher_attr_value_flags_t *,
275     ipc_voucher_t *);
276 
277 typedef kern_return_t (*ipc_voucher_attr_manager_extract_content_t)(ipc_voucher_attr_manager_t,
278     mach_voucher_attr_key_t,
279     mach_voucher_attr_value_handle_array_t,
280     mach_voucher_attr_value_handle_array_size_t,
281     mach_voucher_attr_recipe_command_t *,
282     mach_voucher_attr_content_t,
283     mach_voucher_attr_content_size_t *);
284 
285 typedef kern_return_t (*ipc_voucher_attr_manager_command_t)(ipc_voucher_attr_manager_t,
286     mach_voucher_attr_key_t,
287     mach_voucher_attr_value_handle_array_t,
288     mach_voucher_attr_value_handle_array_size_t,
289     mach_voucher_attr_command_t,
290     mach_voucher_attr_content_t,
291     mach_voucher_attr_content_size_t,
292     mach_voucher_attr_content_t,
293     mach_voucher_attr_content_size_t *);
294 
295 typedef void (*ipc_voucher_attr_manager_release_t)(ipc_voucher_attr_manager_t);
296 
297 typedef uint32_t ipc_voucher_attr_manager_flags;
298 
299 struct ipc_voucher_attr_manager {
300 	ipc_voucher_attr_manager_release_value_t        ivam_release_value;
301 	ipc_voucher_attr_manager_get_value_t            ivam_get_value;
302 	ipc_voucher_attr_manager_extract_content_t      ivam_extract_content;
303 	ipc_voucher_attr_manager_command_t              ivam_command;
304 	ipc_voucher_attr_manager_release_t              ivam_release;
305 	ipc_voucher_attr_manager_flags                  ivam_flags;
306 };
307 
308 #define IVAM_FLAGS_NONE                              0
309 #define IVAM_FLAGS_SUPPORT_SEND_PREPROCESS         0x1
310 #define IVAM_FLAGS_SUPPORT_RECEIVE_POSTPROCESS     0x2
311 
312 __BEGIN_DECLS
313 
314 /* DEBUG/TRACE Convert from a port to a voucher */
315 extern uintptr_t unsafe_convert_port_to_voucher(
316 	ipc_port_t              port) __pure2;
317 
318 /* Convert from a port to a voucher */
319 extern ipc_voucher_t convert_port_to_voucher(
320 	ipc_port_t              port);
321 
322 /* Convert from a port name to an ipc_voucher */
323 extern ipc_voucher_t convert_port_name_to_voucher(
324 	mach_port_name_t        name);
325 
326 /* add a reference to the specified voucher */
327 extern void ipc_voucher_reference(
328 	ipc_voucher_t           voucher);
329 
330 /* drop the voucher reference picked up above */
331 extern void ipc_voucher_release(
332 	ipc_voucher_t           voucher);
333 
334 /* Convert from a voucher to a port */
335 extern ipc_port_t convert_voucher_to_port(
336 	ipc_voucher_t           voucher);
337 
338 /* convert from a voucher attribute control to a port */
339 extern ipc_port_t convert_voucher_attr_control_to_port(
340 	ipc_voucher_attr_control_t      control);
341 
342 /* add a reference to the specified voucher */
343 extern void ipc_voucher_attr_control_reference(
344 	ipc_voucher_attr_control_t      control);
345 
346 /* drop the reference picked up above */
347 extern void ipc_voucher_attr_control_release(
348 	ipc_voucher_attr_control_t      control);
349 
350 /* convert from a port to a voucher attribute control */
351 extern ipc_voucher_attr_control_t convert_port_to_voucher_attr_control(
352 	ipc_port_t              port);
353 
354 /*
355  * In-kernel equivalents to the user syscalls
356  */
357 extern kern_return_t
358 ipc_create_mach_voucher(
359 	ipc_voucher_attr_raw_recipe_array_t             recipes,
360 	ipc_voucher_attr_raw_recipe_array_size_t        recipe_size,
361 	ipc_voucher_t                                   *new_voucher);
362 
363 extern kern_return_t
364 ipc_voucher_attr_control_create_mach_voucher(
365 	ipc_voucher_attr_control_t                      control,
366 	ipc_voucher_attr_raw_recipe_array_t             recipes,
367 	ipc_voucher_attr_raw_recipe_array_size_t        recipe_size,
368 	ipc_voucher_t                                   *new_voucher);
369 
370 extern kern_return_t
371 ipc_register_well_known_mach_voucher_attr_manager(
372 	ipc_voucher_attr_manager_t              manager,
373 	mach_voucher_attr_value_handle_t        default_value,
374 	mach_voucher_attr_key_t                 key,
375 	ipc_voucher_attr_control_t              *control);
376 
377 
378 extern kern_return_t
379 ipc_register_mach_voucher_attr_manager(
380 	ipc_voucher_attr_manager_t              manager,
381 	mach_voucher_attr_value_handle_t        default_value,
382 	mach_voucher_attr_key_t                 *key,
383 	ipc_voucher_attr_control_t              *control);
384 
385 __END_DECLS
386 
387 #endif  /* _IPC_IPC_VOUCHER_H_ */
388