path: root/ipc/ipc_port.h

/*
 * Mach Operating System
 * Copyright (c) 1991,1990,1989 Carnegie Mellon University.
 * Copyright (c) 1993,1994 The University of Utah and
 * the Computer Systems Laboratory (CSL).
 * 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, THE UNIVERSITY OF UTAH AND CSL ALLOW FREE USE OF
 * THIS SOFTWARE IN ITS "AS IS" CONDITION, AND DISCLAIM 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_port.h
 *	Author:	Rich Draves
 *	Date:	1989
 *
 *	Definitions for ports.
 */

#ifndef	_IPC_IPC_PORT_H_
#define _IPC_IPC_PORT_H_

#include <mach/boolean.h>
#include <mach/kern_return.h>
#include <mach/port.h>
#include <kern/lock.h>
#include <kern/macros.h>
#include <kern/ipc_kobject.h>
#include <ipc/ipc_mqueue.h>
#include <ipc/ipc_table.h>
#include <ipc/ipc_thread.h>
#include <ipc/ipc_object.h>
#include "ipc_target.h"
#include <mach/rpc.h>

/*
 *  A receive right (port) can be in four states:
 *	1) dead (not active, ip_timestamp has death time)
 *	2) in a space (ip_receiver_name != 0, ip_receiver points
 *	to the space but doesn't hold a ref for it)
 *	3) in transit (ip_receiver_name == 0, ip_destination points
 *	to the destination port and holds a ref for it)
 *	4) in limbo (ip_receiver_name == 0, ip_destination == IP_NULL)
 *
 *  If the port is active, and ip_receiver points to some space,
 *  then ip_receiver_name != 0, and that space holds receive rights.
 *  If the port is not active, then ip_timestamp contains a timestamp
 *  taken when the port was destroyed.
 */

typedef unsigned int ipc_port_timestamp_t;

struct ipc_port {
	struct ipc_target ip_target;

	/* This points to the ip_target above if this port isn't on a port set;
	   otherwise it points to the port set's ips_target.  */
	struct ipc_target *ip_cur_target;

	union {
		struct ipc_space *receiver;
		struct ipc_port *destination;
		ipc_port_timestamp_t timestamp;
	} data;

	/* Note: For pagers (IKOT_PAGER), this field is protected by
	   vm_object_cache_lock.  */
	ipc_kobject_t ip_kobject;

	mach_port_mscount_t ip_mscount;
	mach_port_rights_t ip_srights;
	mach_port_rights_t ip_sorights;

	struct ipc_port *ip_nsrequest;
	struct ipc_port *ip_pdrequest;
	struct ipc_port_request *ip_dnrequests;

	struct ipc_pset *ip_pset;
	mach_port_seqno_t ip_seqno;		/* locked by message queue */
	mach_port_msgcount_t ip_msgcount;
	mach_port_msgcount_t ip_qlimit;
	struct ipc_thread_queue ip_blocked;
	unsigned long ip_protected_payload;
};

#define ip_object		ip_target.ipt_object
#define ip_receiver_name	ip_target.ipt_name
#define ip_messages		ip_target.ipt_messages
#define	ip_references		ip_object.io_references
#define	ip_bits			ip_object.io_bits
#define	ip_receiver		data.receiver
#define	ip_destination		data.destination
#define	ip_timestamp		data.timestamp

#define	IP_NULL			((ipc_port_t) IO_NULL)
#define	IP_DEAD			((ipc_port_t) IO_DEAD)

#define	IP_VALID(port)		IO_VALID(&(port)->ip_object)

#define	ip_active(port)		io_active(&(port)->ip_object)
#define	ip_lock_init(port)	io_lock_init(&(port)->ip_object)
#define	ip_lock(port)		io_lock(&(port)->ip_object)
#define	ip_lock_surrender(port)	io_lock_surrender(&(port)->ip_object)
#define	ip_lock_steal(port)	io_lock_steal(&(port)->ip_object)
#define	ip_lock_try(port)	io_lock_try(&(port)->ip_object)
#define	ip_unlock(port)		io_unlock(&(port)->ip_object)
#define have_ip_lock(port)	have_io_lock(&(port)->ip_object)
#define	ip_check_unlock(port)	io_check_unlock(&(port)->ip_object)
#define	ip_reference(port)	io_reference(&(port)->ip_object)
#define	ip_release(port)	io_release(&(port)->ip_object)

#define	ip_alloc()		((ipc_port_t) io_alloc(IOT_PORT))
#define	ip_free(port)		io_free(IOT_PORT, &(port)->ip_object)

#define	ip_kotype(port)		io_kotype(&(port)->ip_object)

typedef ipc_table_index_t ipc_port_request_index_t;

typedef struct ipc_port_request {
	union {
		struct ipc_port *port;
		ipc_port_request_index_t index;
	} notify;

	union {
		mach_port_t name;
		struct ipc_table_size *size;
	} name;
} *ipc_port_request_t;

#define	ipr_next		notify.index
#define	ipr_size		name.size

#define	ipr_soright		notify.port
#define	ipr_name		name.name

#define	IPR_NULL		((ipc_port_request_t) 0)

/*
 *	Taking the ipc_port_multiple lock grants the privilege
 *	to lock multiple ports at once.  No ports must locked
 *	when it is taken.
 */

extern struct lock ipc_port_multiple_lock_data;

#define	ipc_port_multiple_lock_init()					\
		lock_init(&ipc_port_multiple_lock_data, TRUE)

#define	ipc_port_multiple_lock()					\
		lock_write(&ipc_port_multiple_lock_data)

#define	ipc_port_multiple_unlock()					\
		lock_write_done(&ipc_port_multiple_lock_data)

/*
 *	The port timestamp facility provides timestamps
 *	for port destruction.  It is used to serialize
 *	mach_port_names with port death.
 */

decl_simple_lock_data(extern, ipc_port_timestamp_lock_data)
extern ipc_port_timestamp_t ipc_port_timestamp_data;

#define	ipc_port_timestamp_lock_init()					\
		simple_lock_init(&ipc_port_timestamp_lock_data)

#define	ipc_port_timestamp_lock()					\
		simple_lock(&ipc_port_timestamp_lock_data)

#define	ipc_port_timestamp_unlock()					\
		simple_unlock(&ipc_port_timestamp_lock_data)

extern ipc_port_timestamp_t
ipc_port_timestamp(void);

/*
 *	Compares two timestamps, and returns TRUE if one
 *	happened before two.  Note that this formulation
 *	works when the timestamp wraps around at 2^32,
 *	as long as one and two aren't too far apart.
 */

#define	IP_TIMESTAMP_ORDER(one, two)	((int) ((one) - (two)) < 0)

#define	ipc_port_translate_receive(space, name, portp)			\
		ipc_object_translate((space), (name),			\
				     MACH_PORT_RIGHT_RECEIVE,		\
				     (ipc_object_t *) (portp))

#define	ipc_port_translate_send(space, name, portp)			\
		ipc_object_translate((space), (name),			\
				     MACH_PORT_RIGHT_SEND,		\
				     (ipc_object_t *) (portp))

extern kern_return_t
ipc_port_dnrequest(ipc_port_t, mach_port_t, ipc_port_t,
		   ipc_port_request_index_t *);

extern kern_return_t
ipc_port_dngrow(ipc_port_t);

extern ipc_port_t
ipc_port_dncancel(ipc_port_t, mach_port_t, ipc_port_request_index_t);

#define	ipc_port_dnrename(port, index, oname, nname)			\
MACRO_BEGIN								\
	ipc_port_request_t ipr, table;					\
									\
	assert(ip_active(port));					\
									\
	table = port->ip_dnrequests;					\
	assert(table != IPR_NULL);					\
									\
	ipr = &table[index];						\
	assert(ipr->ipr_name == oname);					\
									\
	ipr->ipr_name = nname;						\
MACRO_END

/* Make a port-deleted request */
extern void ipc_port_pdrequest(
	ipc_port_t	port,
	ipc_port_t	notify,
	ipc_port_t	*previousp);

/* Make a no-senders request */
extern void ipc_port_nsrequest(
	ipc_port_t		port,
	mach_port_mscount_t	sync,
	ipc_port_t		notify,
	ipc_port_t		*previousp);

/* Change a port's queue limit */
extern void ipc_port_set_qlimit(
	ipc_port_t		port,
	mach_port_msgcount_t	qlimit);

#define	ipc_port_set_mscount(port, mscount)				\
MACRO_BEGIN								\
	assert(ip_active(port));					\
									\
	(port)->ip_mscount = (mscount);					\
MACRO_END

extern struct ipc_mqueue *
ipc_port_lock_mqueue(ipc_port_t);

extern void
ipc_port_set_seqno(ipc_port_t, mach_port_seqno_t);

extern void
ipc_port_set_protected_payload(ipc_port_t, unsigned long);

extern void
ipc_port_clear_protected_payload(ipc_port_t);

extern void
ipc_port_clear_receiver(ipc_port_t);

extern void
ipc_port_init(ipc_port_t, ipc_space_t, mach_port_t);

extern kern_return_t
ipc_port_alloc(ipc_space_t, mach_port_t *, ipc_port_t *);

extern kern_return_t
ipc_port_alloc_name(ipc_space_t, mach_port_t, ipc_port_t *);

extern void
ipc_port_destroy(ipc_port_t);

extern boolean_t
ipc_port_check_circularity(ipc_port_t, ipc_port_t);

extern ipc_port_t
ipc_port_lookup_notify(ipc_space_t, mach_port_t);

extern ipc_port_t
ipc_port_make_send(ipc_port_t);

extern ipc_port_t
ipc_port_copy_send(ipc_port_t);

extern mach_port_t
ipc_port_copyout_send(ipc_port_t, ipc_space_t);

extern void
ipc_port_release_send(ipc_port_t);

extern ipc_port_t
ipc_port_make_sonce(ipc_port_t);

extern void
ipc_port_release_sonce(ipc_port_t);

extern void
ipc_port_release_receive(ipc_port_t);

extern ipc_port_t
ipc_port_alloc_special(ipc_space_t);

extern void
ipc_port_dealloc_special(ipc_port_t, ipc_space_t);

#define	ipc_port_alloc_kernel()		\
		ipc_port_alloc_special(ipc_space_kernel)
#define	ipc_port_dealloc_kernel(port)	\
		ipc_port_dealloc_special((port), ipc_space_kernel)

#define	ipc_port_alloc_reply()		\
		ipc_port_alloc_special(ipc_space_reply)
#define	ipc_port_dealloc_reply(port)	\
		ipc_port_dealloc_special((port), ipc_space_reply)

#define	ipc_port_reference(port)	\
		ipc_object_reference(&(port)->ip_object)

#define	ipc_port_release(port)		\
		ipc_object_release(&(port)->ip_object)

static inline boolean_t
ipc_port_flag_protected_payload(const struct ipc_port *port)
{
	return !! (port->ip_target.ipt_object.io_bits
		   & IO_BITS_PROTECTED_PAYLOAD);
}

static inline void
ipc_port_flag_protected_payload_set(struct ipc_port *port)
{
	port->ip_target.ipt_object.io_bits |= IO_BITS_PROTECTED_PAYLOAD;
}

static inline void
ipc_port_flag_protected_payload_clear(struct ipc_port *port)
{
	port->ip_target.ipt_object.io_bits &= ~IO_BITS_PROTECTED_PAYLOAD;
}

#endif	/* _IPC_IPC_PORT_H_ */