text: /*
   * Copyright (c) 2000-2016 Apple Computer, Inc. All rights reserved.
   *
   * @APPLE_OSREFERENCE_LICENSE_HEADER_START@
   * 
   * This file contains Original Code and/or Modifications of Original Code
   * as defined in and that are subject to the Apple Public Source License
   * Version 2.0 (the 'License'). You may not use this file except in
   * compliance with the License. The rights granted to you under the License
   * may not be used to create, or enable the creation or redistribution of,
   * unlawful or unlicensed copies of an Apple operating system, or to
   * circumvent, violate, or enable the circumvention or violation of, any
   * terms of an Apple operating system software license agreement.
   * 
   * Please obtain a copy of the License at
   * http://www.opensource.apple.com/apsl/ and read it before using this file.
   * 
   * The 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, QUIET ENJOYMENT OR NON-INFRINGEMENT.
   * Please see the License for the specific language governing rights and
   * limitations under the License.
   * 
   * @APPLE_OSREFERENCE_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.
   */
  /*
   * NOTICE: This file was modified by McAfee Research in 2004 to introduce
   * support for mandatory and extensible security protections.  This notice
   * is included in support of clause 2.2 (b) of the Apple Public License,
   * Version 2.0.
   */
  /*
   */
  /*
   *	File:	ipc/ipc_port.h
   *	Author:	Rich Draves
   *	Date:	1989
   *
   *	Definitions for ports.
   */
  
  #ifndef	_IPC_IPC_PORT_H_
  #define _IPC_IPC_PORT_H_
  
  #ifdef MACH_KERNEL_PRIVATE
  
  #include <mach_rt.h>
  #include <mach_assert.h>
  #include <mach_debug.h>
  
  #include <mach/mach_types.h>
  #include <mach/boolean.h>
  #include <mach/kern_return.h>
  #include <mach/port.h>
  
  #include <kern/assert.h>
  #include <kern/kern_types.h>
  
  #include <ipc/ipc_types.h>
  #include <ipc/ipc_object.h>
  #include <ipc/ipc_mqueue.h>
  #include <ipc/ipc_space.h>
  
  #include <security/_label.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 {
  
  	/*
  	 * Initial sub-structure in common with ipc_pset
  	 * First element is an ipc_object second is a
  	 * message queue
  	 */
  	struct ipc_object ip_object;
  	struct ipc_mqueue ip_messages;
  
  	union {
  		struct ipc_space *receiver;
  		struct ipc_port *destination;
  		ipc_port_timestamp_t timestamp;
  	} data;
  
  	union {
  		ipc_kobject_t kobject;
  		ipc_importance_task_t imp_task;
  		uintptr_t alias;
  	} kdata;
  		
  	struct ipc_port *ip_nsrequest;
  	struct ipc_port *ip_pdrequest;
  	struct ipc_port_request *ip_requests;
  	struct ipc_kmsg *ip_premsg;
  
  	mach_vm_address_t ip_context;
  
  	natural_t ip_sprequests:1,	/* send-possible requests outstanding */
  		  ip_spimportant:1,	/* ... at least one is importance donating */
  		  ip_impdonation:1,	/* port supports importance donation */
  		  ip_tempowner:1,	/* dont give donations to current receiver */
  		  ip_guarded:1,         /* port guarded (use context value as guard) */
  		  ip_strict_guard:1,	/* Strict guarding; Prevents user manipulation of context values directly */
  		  ip_reserved:2,
  		  ip_impcount:24;	/* number of importance donations in nested queue */
  
  	mach_port_mscount_t ip_mscount;
  	mach_port_rights_t ip_srights;
  	mach_port_rights_t ip_sorights;
  
  #if	MACH_ASSERT
  #define	IP_NSPARES		4
  #define	IP_CALLSTACK_MAX	16
  /*	queue_chain_t	ip_port_links;*//* all allocated ports */
  	thread_t	ip_thread;	/* who made me?  thread context */
  	unsigned long	ip_timetrack;	/* give an idea of "when" created */
  	uintptr_t	ip_callstack[IP_CALLSTACK_MAX]; /* stack trace */
  	unsigned long	ip_spares[IP_NSPARES]; /* for debugging */
  #endif	/* MACH_ASSERT */
  } __attribute__((__packed__));
  
  
  #define ip_references		ip_object.io_references
  #define ip_bits			ip_object.io_bits
  
  #define ip_receiver_name	ip_messages.imq_receiver_name
  #define	ip_in_pset		ip_messages.imq_in_pset
  
  #define	ip_receiver		data.receiver
  #define	ip_destination		data.destination
  #define	ip_timestamp		data.timestamp
  
  #define ip_kobject		kdata.kobject
  #define ip_imp_task		kdata.imp_task
  #define ip_alias		kdata.alias
  
  #define IP_NULL			IPC_PORT_NULL
  #define IP_DEAD			IPC_PORT_DEAD
  #define	IP_VALID(port)		IPC_PORT_VALID(port)
  
  #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_try(port)	io_lock_try(&(port)->ip_object)
  #define	ip_unlock(port)		io_unlock(&(port)->ip_object)
  
  #define	ip_reference(port)	io_reference(&(port)->ip_object)
  #define	ip_release(port)	io_release(&(port)->ip_object)
  
  /* get an ipc_port pointer from an ipc_mqueue pointer */
  #define	ip_from_mq(mq)		((struct ipc_port *)((void *)( \
  					(char *)(mq) - \
  					__offsetof(struct ipc_port, ip_messages)) \
  				))
  
  #define	ip_reference_mq(mq)	ip_reference(ip_from_mq(mq))
  #define	ip_release_mq(mq)	ip_release(ip_from_mq(mq))
  
  #define	ip_kotype(port)		io_kotype(&(port)->ip_object)
  
  #define ip_full_kernel(port)	imq_full_kernel(&(port)->ip_messages) 
  #define ip_full(port)		imq_full(&(port)->ip_messages) 
  
  /*
   * JMM - Preallocation flag
   * This flag indicates that there is a message buffer preallocated for this
   * port and we should use that when sending (from the kernel) rather than
   * allocate a new one.  This avoids deadlocks during notification message
   * sends by critical system threads (which may be needed to free memory and
   * therefore cannot be blocked waiting for memory themselves).
   */
  #define	IP_BIT_PREALLOC		0x00008000	/* preallocated mesg */
  #define IP_PREALLOC(port)	((port)->ip_bits & IP_BIT_PREALLOC)
  
  #define IP_SET_PREALLOC(port, kmsg)				 	\
  MACRO_BEGIN								\
  	(port)->ip_bits |= IP_BIT_PREALLOC;				\
  	(port)->ip_premsg = (kmsg);					\
  MACRO_END
  
  #define IP_CLEAR_PREALLOC(port, kmsg)				 	\
  MACRO_BEGIN								\
  	assert((port)->ip_premsg == kmsg);				\
  	(port)->ip_bits &= ~IP_BIT_PREALLOC;				\
  	(port)->ip_premsg = IKM_NULL;					\
  MACRO_END
  
  /* JMM - address alignment/packing for LP64 */
  struct ipc_port_request {
  	union {
  		struct ipc_port *port;
  		ipc_port_request_index_t index;
  	} notify;
  
  	union {
  		mach_port_name_t name;
  		struct ipc_table_size *size;
  	} name;
  };
  
  #define	ipr_next		notify.index
  #define	ipr_size		name.size
  
  #define	ipr_soright		notify.port
  #define	ipr_name		name.name
  
  /*
   * Use the low bits in the ipr_soright to specify the request type
   */
  #define IPR_SOR_SPARM_MASK	1		/* send-possible armed */
  #define IPR_SOR_SPREQ_MASK	2		/* send-possible requested */
  #define IPR_SOR_SPBIT_MASK	3		/* combo */
  #define IPR_SOR_SPARMED(sor)	(((uintptr_t)(sor) & IPR_SOR_SPARM_MASK) != 0)
  #define IPR_SOR_SPREQ(sor)	(((uintptr_t)(sor) & IPR_SOR_SPREQ_MASK) != 0)
  #define IPR_SOR_PORT(sor)	((ipc_port_t)((uintptr_t)(sor) & ~IPR_SOR_SPBIT_MASK))
  #define IPR_SOR_MAKE(p,m)	((ipc_port_t)((uintptr_t)(p) | (m)))
  
  extern lck_grp_t 	ipc_lck_grp;
  extern lck_attr_t 	ipc_lck_attr;
  
  /*
   *	Taking the ipc_port_multiple lock grants the privilege
   *	to lock multiple ports at once.  No ports must locked
   *	when it is taken.
   */
  
  extern lck_spin_t ipc_port_multiple_lock_data;
  
  #define	ipc_port_multiple_lock_init()					\
  		lck_spin_init(&ipc_port_multiple_lock_data, &ipc_lck_grp, &ipc_lck_attr)
  
  #define	ipc_port_multiple_lock()					\
  		lck_spin_lock(&ipc_port_multiple_lock_data)
  
  #define	ipc_port_multiple_unlock()					\
  		lck_spin_unlock(&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.
   */
  
  extern ipc_port_timestamp_t ipc_port_timestamp_data;
  
  /* Retrieve a port timestamp value */
  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))
  
  /* Allocate a notification request slot */
  #if IMPORTANCE_INHERITANCE
  extern kern_return_t
  ipc_port_request_alloc(
  	ipc_port_t			port,
  	mach_port_name_t		name,
  	ipc_port_t			soright,
  	boolean_t			send_possible,
  	boolean_t			immediate,
  	ipc_port_request_index_t	*indexp,
  	boolean_t			*importantp);
  #else
  extern kern_return_t
  ipc_port_request_alloc(
  	ipc_port_t			port,
  	mach_port_name_t		name,
  	ipc_port_t			soright,
  	boolean_t			send_possible,
  	boolean_t			immediate,
  	ipc_port_request_index_t	*indexp);
  #endif /* IMPORTANCE_INHERITANCE */
  
  /* Grow one of a port's tables of notifcation requests */
  extern kern_return_t ipc_port_request_grow(
  	ipc_port_t			port,
  	ipc_table_elems_t		target_size);
  
  /* Return the type(s) of notification requests outstanding */
  extern mach_port_type_t ipc_port_request_type(
  	ipc_port_t			port,
  	mach_port_name_t		name,
  	ipc_port_request_index_t	index);
  
  /* Cancel a notification request and return the send-once right */
  extern ipc_port_t ipc_port_request_cancel(
  	ipc_port_t			port,
  	mach_port_name_t		name,
  	ipc_port_request_index_t	index);
  
  /* Arm any delayed send-possible notification */
  extern boolean_t ipc_port_request_sparm(
  	ipc_port_t                port,
  	mach_port_name_t          name,
  	ipc_port_request_index_t  index,
  	mach_msg_option_t         option,
  	mach_msg_priority_t       override);
  
  /* Macros for manipulating a port's dead name notificaiton requests */
  #define	ipc_port_request_rename(port, index, oname, nname)		\
  MACRO_BEGIN								\
  	ipc_port_request_t ipr, table;					\
  									\
  	assert(ip_active(port));					\
  									\
  	table = port->ip_requests;					\
  	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);
  
  #define	ipc_port_set_mscount(port, mscount)				\
  MACRO_BEGIN								\
  	assert(ip_active(port));					\
  									\
  	(port)->ip_mscount = (mscount);					\
  MACRO_END
  
  /* Prepare a receive right for transmission/destruction */
  extern boolean_t ipc_port_clear_receiver(
  	ipc_port_t		port,
  	boolean_t		should_destroy);
  
  /* Initialize a newly-allocated port */
  extern void ipc_port_init(
  	ipc_port_t		port,
  	ipc_space_t		space,
  	mach_port_name_t	name);
  
  /* Allocate a port */
  extern kern_return_t ipc_port_alloc(
  	ipc_space_t		space,
  	mach_port_name_t	*namep,
  	ipc_port_t		*portp);
  
  /* Allocate a port, with a specific name */
  extern kern_return_t ipc_port_alloc_name(
  	ipc_space_t		space,
  	mach_port_name_t	name,
  	ipc_port_t		*portp);
  
  /* Generate dead name notifications */
  extern void ipc_port_dnnotify(
  	ipc_port_t		port);
  
  /* Generate send-possible notifications */
  extern void ipc_port_spnotify(
  	ipc_port_t		port);
  
  /* Destroy a port */
  extern void ipc_port_destroy(
  	ipc_port_t	port);
  
  /* Check if queueing "port" in a message for "dest" would create a circular 
     group of ports and messages */
  extern boolean_t
  ipc_port_check_circularity(
  	ipc_port_t	port,
  	ipc_port_t	dest);
  
  #if IMPORTANCE_INHERITANCE
  
  enum {
  	IPID_OPTION_NORMAL       = 0, /* normal boost */
  	IPID_OPTION_SENDPOSSIBLE = 1, /* send-possible induced boost */
  };
  
  /* apply importance delta to port only */
  extern mach_port_delta_t
  ipc_port_impcount_delta(
  	ipc_port_t 		port,
  	mach_port_delta_t	delta,
  	ipc_port_t		base);
  
  /* apply importance delta to port, and return task importance for update */
  extern boolean_t
  ipc_port_importance_delta_internal(
  	ipc_port_t 		port,
  	natural_t		options,
  	mach_port_delta_t	*deltap,
  	ipc_importance_task_t	*imp_task);
  
  /* Apply an importance delta to a port and reflect change in receiver task */
  extern boolean_t
  ipc_port_importance_delta(
  	ipc_port_t 		port,
  	natural_t		options,
  	mach_port_delta_t	delta);
  #endif /* IMPORTANCE_INHERITANCE */
  
  /* Make a send-once notify port from a receive right */
  extern ipc_port_t ipc_port_lookup_notify(
  	ipc_space_t		space, 
  	mach_port_name_t 	name);
  
  /* Make a naked send right from a receive right - port locked and active */
  extern ipc_port_t ipc_port_make_send_locked(
  	ipc_port_t	port);
  
  /* Make a naked send right from a receive right */
  extern ipc_port_t ipc_port_make_send(
  	ipc_port_t	port);
  
  /* Make a naked send right from another naked send right */
  extern ipc_port_t ipc_port_copy_send(
  	ipc_port_t	port);
  
  /* Copyout a naked send right */
  extern mach_port_name_t ipc_port_copyout_send(
  	ipc_port_t	sright,
  	ipc_space_t	space);
  
  #endif /* MACH_KERNEL_PRIVATE */
  
  #if KERNEL_PRIVATE
  
  /* Release a (valid) naked send right */
  extern void ipc_port_release_send(
  	ipc_port_t	port);
  
  extern void ipc_port_reference(
  	ipc_port_t port);
  
  extern void ipc_port_release(
  	ipc_port_t port);
  
  #endif /* KERNEL_PRIVATE */
  
  #ifdef MACH_KERNEL_PRIVATE
  
  /* Make a naked send-once right from a locked and active receive right */
  extern ipc_port_t ipc_port_make_sonce_locked(
  	ipc_port_t	port);
  
  /* Make a naked send-once right from a receive right */
  extern ipc_port_t ipc_port_make_sonce(
  	ipc_port_t	port);
  
  /* Release a naked send-once right */
  extern void ipc_port_release_sonce(
  	ipc_port_t	port);
  
  /* Release a naked (in limbo or in transit) receive right */
  extern void ipc_port_release_receive(
  	ipc_port_t	port);
  
  /* finalize the destruction of a port before it gets freed */
  extern void ipc_port_finalize(
  	ipc_port_t	port);
  
  /* Allocate a port in a special space */
  extern ipc_port_t ipc_port_alloc_special(
  	ipc_space_t	space);
  
  /* Deallocate a port in a special space */
  extern void ipc_port_dealloc_special(
  	ipc_port_t	port,
  	ipc_space_t	space);
  
  #if	MACH_ASSERT
  /* Track low-level port deallocation */
  extern void ipc_port_track_dealloc(
  	ipc_port_t	port);
  
  /* Initialize general port debugging state */
  extern void ipc_port_debug_init(void);
  #endif	/* MACH_ASSERT */
  
  #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)
  
  #endif /* MACH_KERNEL_PRIVATE */
  
  #endif	/* _IPC_IPC_PORT_H_ */
  