[apple/xnu.git] / osfmk / ipc / ipc_kmsg.h

/*
 * Copyright (c) 2000 Apple Computer, Inc. All rights reserved.
 *
 * @APPLE_LICENSE_HEADER_START@
 * 
 * The contents of this file constitute Original Code as defined in and
 * are subject to the Apple Public Source License Version 1.1 (the
 * "License").  You may not use this file except in compliance with the
 * License.  Please obtain a copy of the License at
 * http://www.apple.com/publicsource and read it before using this file.
 * 
 * This Original Code and all software distributed under the License are
 * distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY KIND, EITHER
 * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
 * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE OR NON-INFRINGEMENT.  Please see the
 * License for the specific language governing rights and limitations
 * under the License.
 * 
 * @APPLE_LICENSE_HEADER_END@
 */
/*
 * @OSF_COPYRIGHT@
 */
/* 
 * Mach Operating System
 * Copyright (c) 1991,1990,1989 Carnegie Mellon University
 * All Rights Reserved.
 * 
 * Permission to use, copy, modify and distribute this software and its
 * documentation is hereby granted, provided that both the copyright
 * notice and this permission notice appear in all copies of the
 * software, derivative works or modified versions, and any portions
 * thereof, and that both notices appear in supporting documentation.
 * 
 * CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS"
 * CONDITION.  CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND FOR
 * ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE.
 * 
 * Carnegie Mellon requests users of this software to return to
 * 
 *  Software Distribution Coordinator  or  Software.Distribution@CS.CMU.EDU
 *  School of Computer Science
 *  Carnegie Mellon University
 *  Pittsburgh PA 15213-3890
 * 
 * any improvements or extensions that they make and grant Carnegie Mellon
 * the rights to redistribute these changes.
 */
/*
 */
/*
 *	File:	ipc/ipc_kmsg.h
 *	Author:	Rich Draves
 *	Date:	1989
 *
 *	Definitions for kernel messages.
 */

#ifndef	_IPC_IPC_KMSG_H_
#define _IPC_IPC_KMSG_H_

#include <cpus.h>

#include <mach/vm_types.h>
#include <mach/message.h>
#include <kern/assert.h>
#include <kern/cpu_number.h>
#include <kern/macro_help.h>
#include <kern/kalloc.h>
#include <ipc/ipc_object.h>

/*
 *	This structure is only the header for a kmsg buffer;
 *	the actual buffer is normally larger.  The rest of the buffer
 *	holds the body of the message.
 *
 *	In a kmsg, the port fields hold pointers to ports instead
 *	of port names.  These pointers hold references.
 *
 *	The ikm_header.msgh_remote_port field is the destination
 *	of the message.
 */


typedef struct ipc_kmsg {
	struct ipc_kmsg *ikm_next;
	struct ipc_kmsg *ikm_prev;
	ipc_port_t ikm_prealloc;	/* port we were preallocated from */
	mach_msg_size_t ikm_size;
	mach_msg_header_t ikm_header;
} *ipc_kmsg_t;

#define	IKM_NULL		((ipc_kmsg_t) 0)

#define	IKM_OVERHEAD							\
		(sizeof(struct ipc_kmsg) - sizeof(mach_msg_header_t))

#define	ikm_plus_overhead(size)	((mach_msg_size_t)((size) + IKM_OVERHEAD))
#define	ikm_less_overhead(size)	((mach_msg_size_t)((size) - IKM_OVERHEAD))

/*
 * XXX	For debugging.
 */
#define IKM_BOGUS		((ipc_kmsg_t) 0xffffff10)

/*
 *	The size of the kernel message buffers that will be cached.
 *	IKM_SAVED_KMSG_SIZE includes overhead; IKM_SAVED_MSG_SIZE doesn't.
 */

#define	IKM_SAVED_MSG_SIZE	ikm_less_overhead(256)

#define	ikm_prealloc_inuse_port(kmsg)					\
	((kmsg)->ikm_prealloc)

#define	ikm_prealloc_inuse(kmsg)					\
	((kmsg)->ikm_prealloc != IP_NULL)

#define	ikm_prealloc_set_inuse(kmsg, port)				\
MACRO_BEGIN								\
	assert((port) != IP_NULL);					\
	(kmsg)->ikm_prealloc = (port);					\
	ip_reference(port);						\
MACRO_END

#define ikm_prealloc_clear_inuse(kmsg, port)				\
MACRO_BEGIN								\
	(kmsg)->ikm_prealloc = IP_NULL;					\
	ip_release(port);						\
MACRO_END


#define	ikm_init(kmsg, size)						\
MACRO_BEGIN								\
	(kmsg)->ikm_size = (size);					\
	(kmsg)->ikm_prealloc = IP_NULL;					\
	assert((kmsg)->ikm_prev = (kmsg)->ikm_next = IKM_BOGUS);	\
MACRO_END

#define	ikm_check_init(kmsg, size)					\
MACRO_BEGIN								\
	assert((kmsg)->ikm_size == (size));				\
	assert((kmsg)->ikm_prev == IKM_BOGUS);				\
	assert((kmsg)->ikm_next == IKM_BOGUS);				\
MACRO_END

struct ipc_kmsg_queue {
	struct ipc_kmsg *ikmq_base;
};

typedef struct ipc_kmsg_queue *ipc_kmsg_queue_t;

#define	IKMQ_NULL		((ipc_kmsg_queue_t) 0)


/*
 * Exported interfaces
 */

#define	ipc_kmsg_queue_init(queue)		\
MACRO_BEGIN					\
	(queue)->ikmq_base = IKM_NULL;		\
MACRO_END

#define	ipc_kmsg_queue_empty(queue)	((queue)->ikmq_base == IKM_NULL)

/* Enqueue a kmsg */
extern void ipc_kmsg_enqueue(
	ipc_kmsg_queue_t	queue,
	ipc_kmsg_t		kmsg);

/* Dequeue and return a kmsg */
extern ipc_kmsg_t ipc_kmsg_dequeue(
	ipc_kmsg_queue_t        queue);

/* Pull a kmsg out of a queue */
extern void ipc_kmsg_rmqueue(
	ipc_kmsg_queue_t	queue,
	ipc_kmsg_t		kmsg);

#define	ipc_kmsg_queue_first(queue)		((queue)->ikmq_base)

/* Return the kmsg following the given kmsg */
extern ipc_kmsg_t ipc_kmsg_queue_next(
	ipc_kmsg_queue_t	queue,
	ipc_kmsg_t		kmsg);

#define	ipc_kmsg_rmqueue_first_macro(queue, kmsg)			\
MACRO_BEGIN								\
	register ipc_kmsg_t _next;					\
									\
	assert((queue)->ikmq_base == (kmsg));				\
									\
	_next = (kmsg)->ikm_next;					\
	if (_next == (kmsg)) {						\
		assert((kmsg)->ikm_prev == (kmsg));			\
		(queue)->ikmq_base = IKM_NULL;				\
	} else {							\
		register ipc_kmsg_t _prev = (kmsg)->ikm_prev;		\
									\
		(queue)->ikmq_base = _next;				\
		_next->ikm_prev = _prev;				\
		_prev->ikm_next = _next;				\
	}								\
  	/* XXX Debug paranoia ASSIGNMENTS */				\
  	assert(kmsg->ikm_next = IKM_BOGUS);				\
  	assert(kmsg->ikm_prev = IKM_BOGUS);				\
MACRO_END

#define	ipc_kmsg_enqueue_macro(queue, kmsg)				\
MACRO_BEGIN								\
	register ipc_kmsg_t _first = (queue)->ikmq_base;		\
									\
	if (_first == IKM_NULL) {					\
		(queue)->ikmq_base = (kmsg);				\
		(kmsg)->ikm_next = (kmsg);				\
		(kmsg)->ikm_prev = (kmsg);				\
	} else {							\
		register ipc_kmsg_t _last = _first->ikm_prev;		\
									\
		(kmsg)->ikm_next = _first;				\
		(kmsg)->ikm_prev = _last;				\
		_first->ikm_prev = (kmsg);				\
		_last->ikm_next = (kmsg);				\
	}								\
MACRO_END

/* scatter list macros */

#define SKIP_PORT_DESCRIPTORS(s, e)					\
MACRO_BEGIN								\
	if ((s) != MACH_MSG_DESCRIPTOR_NULL) {				\
		while ((s) < (e)) {					\
			if ((s)->type.type != MACH_MSG_PORT_DESCRIPTOR)	\
				break;					\
			(s)++;						\
		}							\
		if ((s) >= (e))						\
			(s) = MACH_MSG_DESCRIPTOR_NULL;			\
	}								\
MACRO_END

#define INCREMENT_SCATTER(s)						\
MACRO_BEGIN								\
	if ((s) != MACH_MSG_DESCRIPTOR_NULL) {				\
		(s)++;							\
	}								\
MACRO_END

/*
 *	extern void
 *	ipc_kmsg_send_always(ipc_kmsg_t);
 *
 *	Unfortunately, to avoid warnings/lint about unused variables
 *	when assertions are turned off, we need two versions of this.
 */
#if	MACH_ASSERT

#define	ipc_kmsg_send_always(kmsg)					\
MACRO_BEGIN								\
	mach_msg_return_t mr;						\
									\
	mr = ipc_kmsg_send((kmsg), MACH_SEND_ALWAYS,			\
			     MACH_MSG_TIMEOUT_NONE);			\
	assert(mr == MACH_MSG_SUCCESS);					\
MACRO_END

#else	/* MACH_ASSERT */

#define	ipc_kmsg_send_always(kmsg)					\
MACRO_BEGIN								\
	(void) ipc_kmsg_send((kmsg), MACH_SEND_ALWAYS,			\
			       MACH_MSG_TIMEOUT_NONE);			\
MACRO_END

#endif	/* MACH_ASSERT */

/* Allocate a kernel message */
extern ipc_kmsg_t ipc_kmsg_alloc(
        mach_msg_size_t size);

/* Free a kernel message buffer */
extern void ipc_kmsg_free(
	ipc_kmsg_t	kmsg);

/* Destroy kernel message */
extern void ipc_kmsg_destroy(
	ipc_kmsg_t	kmsg);

/* Preallocate a kernel message buffer */
extern void ipc_kmsg_set_prealloc(
	ipc_kmsg_t	kmsg,
	ipc_port_t	port);

/* Clear a kernel message buffer */
extern void ipc_kmsg_clear_prealloc(
	ipc_kmsg_t	kmsg,
	ipc_port_t	port);

/* Allocate a kernel message buffer and copy a user message to the buffer */
extern mach_msg_return_t ipc_kmsg_get(
	mach_msg_header_t	*msg,
	mach_msg_size_t		size,
	ipc_kmsg_t		*kmsgp);

/* Allocate a kernel message buffer and copy a kernel message to the buffer */
extern mach_msg_return_t ipc_kmsg_get_from_kernel(
	mach_msg_header_t	*msg,
	mach_msg_size_t		size,
	ipc_kmsg_t		*kmsgp);

/* Send a message to a port */
extern mach_msg_return_t ipc_kmsg_send(
	ipc_kmsg_t		kmsg,
	mach_msg_option_t	option,
	mach_msg_timeout_t	timeout);

/* Copy a kernel message buffer to a user message */
extern mach_msg_return_t ipc_kmsg_put(
	mach_msg_header_t	*msg,
	ipc_kmsg_t		kmsg,
	mach_msg_size_t		size);

/* Copy a kernel message buffer to a kernel message */
extern void ipc_kmsg_put_to_kernel(
	mach_msg_header_t	*msg,
	ipc_kmsg_t		kmsg,
	mach_msg_size_t		size);

/* Copyin port rights in the header of a message */
extern mach_msg_return_t ipc_kmsg_copyin_header(
	mach_msg_header_t	*msg,
	ipc_space_t		space,
	mach_port_name_t	notify);

/* Copyin port rights and out-of-line memory from a user message */
extern mach_msg_return_t ipc_kmsg_copyin(
	ipc_kmsg_t		kmsg,
	ipc_space_t		space,
	vm_map_t		map,
	mach_port_name_t	notify);

/* Copyin port rights and out-of-line memory from a kernel message */
extern void ipc_kmsg_copyin_from_kernel(
	ipc_kmsg_t		kmsg);

/* Copyout port rights in the header of a message */
extern mach_msg_return_t ipc_kmsg_copyout_header(
	mach_msg_header_t	*msg,
	ipc_space_t		space,
	mach_port_name_t	notify);

/* Copyout a port right returning a name */
extern mach_msg_return_t ipc_kmsg_copyout_object(
	ipc_space_t		space,
	ipc_object_t		object,
	mach_msg_type_name_t	msgt_name,
	mach_port_name_t	*namep);

/* Copyout the header and body to a user message */
extern mach_msg_return_t ipc_kmsg_copyout(
	ipc_kmsg_t		kmsg,
	ipc_space_t		space,
	vm_map_t		map,
	mach_port_name_t	notify,
	mach_msg_body_t		*slist);

/* Copyout port rights and out-of-line memory from the body of a message */
extern mach_msg_return_t ipc_kmsg_copyout_body(
    	ipc_kmsg_t		kmsg,
	ipc_space_t		space,
	vm_map_t		map,
	mach_msg_body_t		*slist);

/* Copyout port rights and out-of-line memory to a user message,
   not reversing the ports in the header */
extern mach_msg_return_t ipc_kmsg_copyout_pseudo(
	ipc_kmsg_t		kmsg,
	ipc_space_t		space,
	vm_map_t		map,
	mach_msg_body_t		*slist);

/* Copyout the destination port in the message */
extern void ipc_kmsg_copyout_dest( 
	ipc_kmsg_t		kmsg,
	ipc_space_t		space);

/* kernel's version of ipc_kmsg_copyout_dest */
extern void ipc_kmsg_copyout_to_kernel(
	ipc_kmsg_t		kmsg,
	ipc_space_t		space);

/* copyin a scatter list and check consistency */
extern mach_msg_body_t *ipc_kmsg_copyin_scatter(
        mach_msg_header_t       *msg,
        mach_msg_size_t         slist_size,
        ipc_kmsg_t              kmsg);

/* free a scatter list */
extern void ipc_kmsg_free_scatter(
        mach_msg_body_t 	*slist,
        mach_msg_size_t		slist_size);

#include <mach_kdb.h>
#if 	MACH_KDB

/* Do a formatted dump of a kernel message */
extern void ipc_kmsg_print(
	ipc_kmsg_t	kmsg);

/* Do a formatted dump of a user message */
extern void ipc_msg_print(
	mach_msg_header_t	*msgh);

#endif	/* MACH_KDB */

#endif	/* _IPC_IPC_KMSG_H_ */
Commit	Line	Data
1c79356b A	1	/*
	2	* Copyright (c) 2000 Apple Computer, Inc. All rights reserved.
	3	*
	4	* @APPLE_LICENSE_HEADER_START@
	5	*
de355530 A	6	* The contents of this file constitute Original Code as defined in and
	7	* are subject to the Apple Public Source License Version 1.1 (the
	8	* "License"). You may not use this file except in compliance with the
	9	* License. Please obtain a copy of the License at
	10	* http://www.apple.com/publicsource and read it before using this file.
1c79356b	11	*
de355530 A	12	* This Original Code and all software distributed under the License are
de355530 A	13	* distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY KIND, EITHER
1c79356b A	14	* EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
1c79356b A	15	* INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
de355530 A	16	* FITNESS FOR A PARTICULAR PURPOSE OR NON-INFRINGEMENT. Please see the
	17	* License for the specific language governing rights and limitations
	18	* under the License.
1c79356b A	19	*
	20	* @APPLE_LICENSE_HEADER_END@
	21	*/
	22	/*
	23	* @OSF_COPYRIGHT@
	24	*/
	25	/*
	26	* Mach Operating System
	27	* Copyright (c) 1991,1990,1989 Carnegie Mellon University
	28	* All Rights Reserved.
	29	*
	30	* Permission to use, copy, modify and distribute this software and its
	31	* documentation is hereby granted, provided that both the copyright
	32	* notice and this permission notice appear in all copies of the
	33	* software, derivative works or modified versions, and any portions
	34	* thereof, and that both notices appear in supporting documentation.
	35	*
	36	* CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS"
	37	* CONDITION. CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND FOR
	38	* ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE.
	39	*
	40	* Carnegie Mellon requests users of this software to return to
	41	*
	42	* Software Distribution Coordinator or Software.Distribution@CS.CMU.EDU
	43	* School of Computer Science
	44	* Carnegie Mellon University
	45	* Pittsburgh PA 15213-3890
	46	*
	47	* any improvements or extensions that they make and grant Carnegie Mellon
	48	* the rights to redistribute these changes.
	49	*/
	50	/*
	51	*/
	52	/*
	53	* File: ipc/ipc_kmsg.h
	54	* Author: Rich Draves
	55	* Date: 1989
	56	*
	57	* Definitions for kernel messages.
	58	*/
	59
	60	#ifndef _IPC_IPC_KMSG_H_
	61	#define _IPC_IPC_KMSG_H_
	62
	63	#include <cpus.h>
	64
	65	#include <mach/vm_types.h>
	66	#include <mach/message.h>
	67	#include <kern/assert.h>
	68	#include <kern/cpu_number.h>
	69	#include <kern/macro_help.h>
	70	#include <kern/kalloc.h>
	71	#include <ipc/ipc_object.h>
	72
	73	/*
	74	* This structure is only the header for a kmsg buffer;
	75	* the actual buffer is normally larger. The rest of the buffer
	76	* holds the body of the message.
	77	*
	78	* In a kmsg, the port fields hold pointers to ports instead
	79	* of port names. These pointers hold references.
	80	*
	81	* The ikm_header.msgh_remote_port field is the destination
	82	* of the message.
83	*/
84
85
86	typedef struct ipc_kmsg {
87	struct ipc_kmsg *ikm_next;
88	struct ipc_kmsg *ikm_prev;
89	ipc_port_t ikm_prealloc; /* port we were preallocated from */
90	mach_msg_size_t ikm_size;
91	mach_msg_header_t ikm_header;
92	} *ipc_kmsg_t;
93
94	#define IKM_NULL ((ipc_kmsg_t) 0)
95
96	#define IKM_OVERHEAD \
97	(sizeof(struct ipc_kmsg) - sizeof(mach_msg_header_t))
98
99	#define ikm_plus_overhead(size) ((mach_msg_size_t)((size) + IKM_OVERHEAD))
100	#define ikm_less_overhead(size) ((mach_msg_size_t)((size) - IKM_OVERHEAD))
101
102	/*
103	* XXX For debugging.
104	*/
105	#define IKM_BOGUS ((ipc_kmsg_t) 0xffffff10)
106
107	/*
108	* The size of the kernel message buffers that will be cached.
109	* IKM_SAVED_KMSG_SIZE includes overhead; IKM_SAVED_MSG_SIZE doesn't.
110	*/
111
112	#define IKM_SAVED_MSG_SIZE ikm_less_overhead(256)
113
114	#define ikm_prealloc_inuse_port(kmsg) \
115	((kmsg)->ikm_prealloc)
116
117	#define ikm_prealloc_inuse(kmsg) \
118	((kmsg)->ikm_prealloc != IP_NULL)
119
120	#define ikm_prealloc_set_inuse(kmsg, port) \
121	MACRO_BEGIN \
9bccf70c A	122	assert((port) != IP_NULL); \
	123	(kmsg)->ikm_prealloc = (port); \
	124	ip_reference(port); \
1c79356b A	125	MACRO_END
	126
	127	#define ikm_prealloc_clear_inuse(kmsg, port) \
	128	MACRO_BEGIN \
	129	(kmsg)->ikm_prealloc = IP_NULL; \
9bccf70c	130	ip_release(port); \
1c79356b A	131	MACRO_END
	132
	133
	134	#define ikm_init(kmsg, size) \
	135	MACRO_BEGIN \
	136	(kmsg)->ikm_size = (size); \
	137	(kmsg)->ikm_prealloc = IP_NULL; \
	138	assert((kmsg)->ikm_prev = (kmsg)->ikm_next = IKM_BOGUS); \
	139	MACRO_END
	140
	141	#define ikm_check_init(kmsg, size) \
	142	MACRO_BEGIN \
	143	assert((kmsg)->ikm_size == (size)); \
	144	assert((kmsg)->ikm_prev == IKM_BOGUS); \
	145	assert((kmsg)->ikm_next == IKM_BOGUS); \
	146	MACRO_END
	147
	148	struct ipc_kmsg_queue {
	149	struct ipc_kmsg *ikmq_base;
	150	};
	151
	152	typedef struct ipc_kmsg_queue *ipc_kmsg_queue_t;
	153
	154	#define IKMQ_NULL ((ipc_kmsg_queue_t) 0)
	155
	156
	157	/*
	158	* Exported interfaces
	159	*/
	160
	161	#define ipc_kmsg_queue_init(queue) \
	162	MACRO_BEGIN \
	163	(queue)->ikmq_base = IKM_NULL; \
	164	MACRO_END
	165
	166	#define ipc_kmsg_queue_empty(queue) ((queue)->ikmq_base == IKM_NULL)
	167
	168	/* Enqueue a kmsg */
	169	extern void ipc_kmsg_enqueue(
	170	ipc_kmsg_queue_t queue,
	171	ipc_kmsg_t kmsg);
	172
	173	/* Dequeue and return a kmsg */
	174	extern ipc_kmsg_t ipc_kmsg_dequeue(
	175	ipc_kmsg_queue_t queue);
	176
	177	/* Pull a kmsg out of a queue */
	178	extern void ipc_kmsg_rmqueue(
	179	ipc_kmsg_queue_t queue,
	180	ipc_kmsg_t kmsg);
	181
	182	#define ipc_kmsg_queue_first(queue) ((queue)->ikmq_base)
	183
	184	/* Return the kmsg following the given kmsg */
	185	extern ipc_kmsg_t ipc_kmsg_queue_next(
	186	ipc_kmsg_queue_t queue,
	187	ipc_kmsg_t kmsg);
	188
	189	#define ipc_kmsg_rmqueue_first_macro(queue, kmsg) \
	190	MACRO_BEGIN \
	191	register ipc_kmsg_t _next; \
	192	\
	193	assert((queue)->ikmq_base == (kmsg)); \
	194	\
195	_next = (kmsg)->ikm_next; \
196	if (_next == (kmsg)) { \
197	assert((kmsg)->ikm_prev == (kmsg)); \
198	(queue)->ikmq_base = IKM_NULL; \
199	} else { \
200	register ipc_kmsg_t _prev = (kmsg)->ikm_prev; \
201	\
202	(queue)->ikmq_base = _next; \
203	_next->ikm_prev = _prev; \
204	_prev->ikm_next = _next; \
205	} \
206	/* XXX Debug paranoia ASSIGNMENTS */ \
207	assert(kmsg->ikm_next = IKM_BOGUS); \
208	assert(kmsg->ikm_prev = IKM_BOGUS); \
209	MACRO_END
210
211	#define ipc_kmsg_enqueue_macro(queue, kmsg) \
212	MACRO_BEGIN \
213	register ipc_kmsg_t _first = (queue)->ikmq_base; \
214	\
215	if (_first == IKM_NULL) { \
216	(queue)->ikmq_base = (kmsg); \
217	(kmsg)->ikm_next = (kmsg); \
218	(kmsg)->ikm_prev = (kmsg); \
219	} else { \
220	register ipc_kmsg_t _last = _first->ikm_prev; \
221	\
222	(kmsg)->ikm_next = _first; \
223	(kmsg)->ikm_prev = _last; \
224	_first->ikm_prev = (kmsg); \
225	_last->ikm_next = (kmsg); \
226	} \
227	MACRO_END
228
229	/* scatter list macros */
230
231	#define SKIP_PORT_DESCRIPTORS(s, e) \
232	MACRO_BEGIN \
233	if ((s) != MACH_MSG_DESCRIPTOR_NULL) { \
234	while ((s) < (e)) { \
235	if ((s)->type.type != MACH_MSG_PORT_DESCRIPTOR) \
236	break; \
237	(s)++; \
238	} \
239	if ((s) >= (e)) \
240	(s) = MACH_MSG_DESCRIPTOR_NULL; \
241	} \
242	MACRO_END
243
244	#define INCREMENT_SCATTER(s) \
245	MACRO_BEGIN \
246	if ((s) != MACH_MSG_DESCRIPTOR_NULL) { \
247	(s)++; \
248	} \
249	MACRO_END
250
251	/*
252	* extern void
253	* ipc_kmsg_send_always(ipc_kmsg_t);
254	*
255	* Unfortunately, to avoid warnings/lint about unused variables
256	* when assertions are turned off, we need two versions of this.
257	*/
258	#if MACH_ASSERT
259
260	#define ipc_kmsg_send_always(kmsg) \
261	MACRO_BEGIN \
262	mach_msg_return_t mr; \
263	\
264	mr = ipc_kmsg_send((kmsg), MACH_SEND_ALWAYS, \
265	MACH_MSG_TIMEOUT_NONE); \
266	assert(mr == MACH_MSG_SUCCESS); \
267	MACRO_END
268
269	#else /* MACH_ASSERT */
270
271	#define ipc_kmsg_send_always(kmsg) \
272	MACRO_BEGIN \
273	(void) ipc_kmsg_send((kmsg), MACH_SEND_ALWAYS, \
274	MACH_MSG_TIMEOUT_NONE); \
275	MACRO_END
276
277	#endif /* MACH_ASSERT */
278
279	/* Allocate a kernel message */
280	extern ipc_kmsg_t ipc_kmsg_alloc(
281	mach_msg_size_t size);
282
283	/* Free a kernel message buffer */
284	extern void ipc_kmsg_free(
285	ipc_kmsg_t kmsg);
286
287	/* Destroy kernel message */
288	extern void ipc_kmsg_destroy(
289	ipc_kmsg_t kmsg);
290
291	/* Preallocate a kernel message buffer */
292	extern void ipc_kmsg_set_prealloc(
293	ipc_kmsg_t kmsg,
294	ipc_port_t port);
295
296	/* Clear a kernel message buffer */
297	extern void ipc_kmsg_clear_prealloc(
298	ipc_kmsg_t kmsg,
299	ipc_port_t port);
300
301	/* Allocate a kernel message buffer and copy a user message to the buffer */
302	extern mach_msg_return_t ipc_kmsg_get(
303	mach_msg_header_t *msg,
304	mach_msg_size_t size,
305	ipc_kmsg_t *kmsgp);
306
307	/* Allocate a kernel message buffer and copy a kernel message to the buffer */
308	extern mach_msg_return_t ipc_kmsg_get_from_kernel(
309	mach_msg_header_t *msg,
310	mach_msg_size_t size,
311	ipc_kmsg_t *kmsgp);
312
313	/* Send a message to a port */
314	extern mach_msg_return_t ipc_kmsg_send(
315	ipc_kmsg_t kmsg,
316	mach_msg_option_t option,
317	mach_msg_timeout_t timeout);
318
319	/* Copy a kernel message buffer to a user message */
320	extern mach_msg_return_t ipc_kmsg_put(
321	mach_msg_header_t *msg,
322	ipc_kmsg_t kmsg,
323	mach_msg_size_t size);
324
325	/* Copy a kernel message buffer to a kernel message */
326	extern void ipc_kmsg_put_to_kernel(
327	mach_msg_header_t *msg,
328	ipc_kmsg_t kmsg,
329	mach_msg_size_t size);
330
331	/* Copyin port rights in the header of a message */
332	extern mach_msg_return_t ipc_kmsg_copyin_header(
333	mach_msg_header_t *msg,
334	ipc_space_t space,
335	mach_port_name_t notify);
336
337	/* Copyin port rights and out-of-line memory from a user message */
338	extern mach_msg_return_t ipc_kmsg_copyin(
339	ipc_kmsg_t kmsg,
340	ipc_space_t space,
341	vm_map_t map,
342	mach_port_name_t notify);
343
344	/* Copyin port rights and out-of-line memory from a kernel message */
345	extern void ipc_kmsg_copyin_from_kernel(
346	ipc_kmsg_t kmsg);
347
348	/* Copyout port rights in the header of a message */
349	extern mach_msg_return_t ipc_kmsg_copyout_header(
350	mach_msg_header_t *msg,
351	ipc_space_t space,
352	mach_port_name_t notify);
353
354	/* Copyout a port right returning a name */
355	extern mach_msg_return_t ipc_kmsg_copyout_object(
356	ipc_space_t space,
357	ipc_object_t object,
358	mach_msg_type_name_t msgt_name,
359	mach_port_name_t *namep);
360
361	/* Copyout the header and body to a user message */
362	extern mach_msg_return_t ipc_kmsg_copyout(
363	ipc_kmsg_t kmsg,
364	ipc_space_t space,
365	vm_map_t map,
366	mach_port_name_t notify,
367	mach_msg_body_t *slist);
368
369	/* Copyout port rights and out-of-line memory from the body of a message */
370	extern mach_msg_return_t ipc_kmsg_copyout_body(
371	ipc_kmsg_t kmsg,
372	ipc_space_t space,
373	vm_map_t map,
374	mach_msg_body_t *slist);
375
376	/* Copyout port rights and out-of-line memory to a user message,
377	not reversing the ports in the header */
378	extern mach_msg_return_t ipc_kmsg_copyout_pseudo(
379	ipc_kmsg_t kmsg,
380	ipc_space_t space,
381	vm_map_t map,
382	mach_msg_body_t *slist);
383
384	/* Copyout the destination port in the message */
385	extern void ipc_kmsg_copyout_dest(
386	ipc_kmsg_t kmsg,
387	ipc_space_t space);
388
389	/* kernel's version of ipc_kmsg_copyout_dest */
390	extern void ipc_kmsg_copyout_to_kernel(
391	ipc_kmsg_t kmsg,
392	ipc_space_t space);
393
394	/* copyin a scatter list and check consistency */
395	extern mach_msg_body_t *ipc_kmsg_copyin_scatter(
396	mach_msg_header_t *msg,
397	mach_msg_size_t slist_size,
398	ipc_kmsg_t kmsg);
399
400	/* free a scatter list */
401	extern void ipc_kmsg_free_scatter(
402	mach_msg_body_t *slist,
403	mach_msg_size_t slist_size);
404
405	#include <mach_kdb.h>
406	#if MACH_KDB
407
408	/* Do a formatted dump of a kernel message */
409	extern void ipc_kmsg_print(
410	ipc_kmsg_t kmsg);
411
412	/* Do a formatted dump of a user message */
413	extern void ipc_msg_print(
414	mach_msg_header_t *msgh);
415
416	#endif /* MACH_KDB */
417
418	#endif /* _IPC_IPC_KMSG_H_ */