mach_msg.c   [plain text]

/*
 * Copyright (c) 2000-2007 Apple 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.
 * Copyright (c) 2005 SPARTA, Inc.
 */
/*
 */
/*
 *	File:	ipc/mach_msg.c
 *	Author:	Rich Draves
 *	Date:	1989
 *
 *	Exported message traps.  See mach/message.h.
 */

#include <mach/mach_types.h>
#include <mach/kern_return.h>
#include <mach/port.h>
#include <mach/message.h>
#include <mach/mig_errors.h>
#include <mach/mach_traps.h>

#include <kern/kern_types.h>
#include <kern/assert.h>
#include <kern/counters.h>
#include <kern/cpu_number.h>
#include <kern/ipc_kobject.h>
#include <kern/ipc_mig.h>
#include <kern/task.h>
#include <kern/thread.h>
#include <kern/lock.h>
#include <kern/sched_prim.h>
#include <kern/exception.h>
#include <kern/misc_protos.h>
#include <kern/kalloc.h>
#include <kern/processor.h>
#include <kern/syscall_subr.h>

#include <vm/vm_map.h>

#include <ipc/ipc_types.h>
#include <ipc/ipc_kmsg.h>
#include <ipc/ipc_mqueue.h>
#include <ipc/ipc_object.h>
#include <ipc/ipc_notify.h>
#include <ipc/ipc_port.h>
#include <ipc/ipc_pset.h>
#include <ipc/ipc_space.h>
#include <ipc/ipc_entry.h>

#include <machine/machine_routines.h>
#include <security/mac_mach_internal.h>

#include <sys/kdebug.h>


#ifndef offsetof
#define offsetof(type, member)  ((size_t)(&((type *)0)->member))
#endif /* offsetof */

/*
 * Forward declarations - kernel internal routines
 */

mach_msg_return_t mach_msg_send(
	mach_msg_header_t	*msg,
	mach_msg_option_t	option,
	mach_msg_size_t		send_size,
	mach_msg_timeout_t	send_timeout,
	mach_port_name_t	notify);

mach_msg_return_t mach_msg_receive(
	mach_msg_header_t	*msg,
	mach_msg_option_t	option,
	mach_msg_size_t		rcv_size,
	mach_port_name_t	rcv_name,
	mach_msg_timeout_t	rcv_timeout,
	void 			(*continuation)(mach_msg_return_t),
	mach_msg_size_t		slist_size);


mach_msg_return_t msg_receive_error(
	ipc_kmsg_t		kmsg,
	mach_vm_address_t	msg_addr,
	mach_msg_option_t	option,
	mach_port_seqno_t	seqno,
	ipc_space_t		space);

security_token_t KERNEL_SECURITY_TOKEN = KERNEL_SECURITY_TOKEN_VALUE;
audit_token_t KERNEL_AUDIT_TOKEN = KERNEL_AUDIT_TOKEN_VALUE;

mach_msg_format_0_trailer_t trailer_template = {
	/* mach_msg_trailer_type_t */ MACH_MSG_TRAILER_FORMAT_0,
	/* mach_msg_trailer_size_t */ MACH_MSG_TRAILER_MINIMUM_SIZE,
        /* mach_port_seqno_t */       0,
	/* security_token_t */        KERNEL_SECURITY_TOKEN_VALUE
};

/*
 *	Routine:	mach_msg_send
 *	Purpose:
 *		Send a message.
 *	Conditions:
 *		Nothing locked.
 *	Returns:
 *		MACH_MSG_SUCCESS	Sent the message.
 *		MACH_SEND_MSG_TOO_SMALL	Message smaller than a header.
 *		MACH_SEND_NO_BUFFER	Couldn't allocate buffer.
 *		MACH_SEND_INVALID_DATA	Couldn't copy message data.
 *		MACH_SEND_INVALID_HEADER
 *			Illegal value in the message header bits.
 *		MACH_SEND_INVALID_DEST	The space is dead.
 *		MACH_SEND_INVALID_NOTIFY	Bad notify port.
 *		MACH_SEND_INVALID_DEST	Can't copyin destination port.
 *		MACH_SEND_INVALID_REPLY	Can't copyin reply port.
 *		MACH_SEND_TIMED_OUT	Timeout expired without delivery.
 *		MACH_SEND_INTERRUPTED	Delivery interrupted.
 *		MACH_SEND_NO_NOTIFY	Can't allocate a msg-accepted request.
 *		MACH_SEND_WILL_NOTIFY	Msg-accepted notif. requested.
 *		MACH_SEND_NOTIFY_IN_PROGRESS
 *			This space has already forced a message to this port.
 */

mach_msg_return_t
mach_msg_send(
	mach_msg_header_t	*msg,
	mach_msg_option_t	option,
	mach_msg_size_t		send_size,
	mach_msg_timeout_t	send_timeout,
	mach_port_name_t	notify)
{
	ipc_space_t space = current_space();
	vm_map_t map = current_map();
	ipc_kmsg_t kmsg;
	mach_msg_return_t mr;
	mach_msg_size_t	msg_and_trailer_size;
	mach_msg_max_trailer_t	*trailer;

	if ((send_size < sizeof(mach_msg_header_t)) || (send_size & 3))
		return MACH_SEND_MSG_TOO_SMALL;

	if (send_size > MACH_MSG_SIZE_MAX - MAX_TRAILER_SIZE)
		return MACH_SEND_TOO_LARGE;
	
	msg_and_trailer_size = send_size + MAX_TRAILER_SIZE;

	kmsg = ipc_kmsg_alloc(msg_and_trailer_size);

	if (kmsg == IKM_NULL)
		return MACH_SEND_NO_BUFFER;

	(void) memcpy((void *) kmsg->ikm_header, (const void *) msg, send_size);

	kmsg->ikm_header->msgh_size = send_size;

	/* 
	 * reserve for the trailer the largest space (MAX_TRAILER_SIZE)
	 * However, the internal size field of the trailer (msgh_trailer_size)
	 * is initialized to the minimum (sizeof(mach_msg_trailer_t)), to optimize
	 * the cases where no implicit data is requested.
	 */
	trailer = (mach_msg_max_trailer_t *) ((vm_offset_t)kmsg->ikm_header + send_size);
	trailer->msgh_sender = current_thread()->task->sec_token;
	trailer->msgh_audit = current_thread()->task->audit_token;
	trailer->msgh_trailer_type = MACH_MSG_TRAILER_FORMAT_0;
	trailer->msgh_trailer_size = MACH_MSG_TRAILER_MINIMUM_SIZE;
	
	if (option & MACH_SEND_CANCEL) {
		if (notify == MACH_PORT_NULL)
			mr = MACH_SEND_INVALID_NOTIFY;
		else
			mr = ipc_kmsg_copyin(kmsg, space, map, notify);
	} else
		mr = ipc_kmsg_copyin(kmsg, space, map, MACH_PORT_NULL);
	if (mr != MACH_MSG_SUCCESS) {
		ipc_kmsg_free(kmsg);
		return mr;
	}

	mr = ipc_kmsg_send(kmsg, option & MACH_SEND_TIMEOUT, send_timeout);

	if (mr != MACH_MSG_SUCCESS) {
	    mr |= ipc_kmsg_copyout_pseudo(kmsg, space, map, MACH_MSG_BODY_NULL);
	    (void) memcpy((void *) msg, (const void *) kmsg->ikm_header, 
			  kmsg->ikm_header->msgh_size);
	    ipc_kmsg_free(kmsg);
	}

	return mr;
}

/*
 *	Routine:	mach_msg_receive
 *	Purpose:
 *		Receive a message.
 *	Conditions:
 *		Nothing locked.
 *	Returns:
 *		MACH_MSG_SUCCESS	Received a message.
 *		MACH_RCV_INVALID_NAME	The name doesn't denote a right,
 *			or the denoted right is not receive or port set.
 *		MACH_RCV_IN_SET		Receive right is a member of a set.
 *		MACH_RCV_TOO_LARGE	Message wouldn't fit into buffer.
 *		MACH_RCV_TIMED_OUT	Timeout expired without a message.
 *		MACH_RCV_INTERRUPTED	Reception interrupted.
 *		MACH_RCV_PORT_DIED	Port/set died while receiving.
 *		MACH_RCV_PORT_CHANGED	Port moved into set while receiving.
 *		MACH_RCV_INVALID_DATA	Couldn't copy to user buffer.
 *		MACH_RCV_INVALID_NOTIFY	Bad notify port.
 *		MACH_RCV_HEADER_ERROR
 */

mach_msg_return_t
mach_msg_receive_results(void)
{
	thread_t          self = current_thread();
	ipc_space_t       space = current_space();
	vm_map_t	  map = current_map();

	ipc_object_t      object = self->ith_object;
	mach_msg_return_t mr = self->ith_state;
	mach_vm_address_t msg_addr = self->ith_msg_addr;
	mach_msg_option_t option = self->ith_option;
	ipc_kmsg_t        kmsg = self->ith_kmsg;
	mach_port_seqno_t seqno = self->ith_seqno;

	mach_msg_max_trailer_t *trailer;

	ipc_object_release(object);

	if (mr != MACH_MSG_SUCCESS) {

	  if (mr == MACH_RCV_TOO_LARGE ) {
	    if (option & MACH_RCV_LARGE) {
	      /*
	       * We need to inform the user-level code that it needs more
	       * space.  The value for how much space was returned in the
	       * msize save area instead of the message (which was left on
	       * the queue).
	       */
	      if (copyout((char *) &self->ith_msize,
			  msg_addr + offsetof(mach_msg_header_t, msgh_size),
			  sizeof(mach_msg_size_t)))
		mr = MACH_RCV_INVALID_DATA;
	      goto out;
	    }
		  
	    if (msg_receive_error(kmsg, msg_addr, option, seqno, space)
		== MACH_RCV_INVALID_DATA)
	      mr = MACH_RCV_INVALID_DATA;
	  }
	  goto out;
	}

	trailer = (mach_msg_max_trailer_t *)
			((vm_offset_t)kmsg->ikm_header +
			round_msg(kmsg->ikm_header->msgh_size));
	if (option & MACH_RCV_TRAILER_MASK) {
		trailer->msgh_seqno = seqno;
		trailer->msgh_context = 
			kmsg->ikm_header->msgh_remote_port->ip_context;
		trailer->msgh_trailer_size = REQUESTED_TRAILER_SIZE(option);

		if (MACH_RCV_TRAILER_ELEMENTS(option) >= 
				MACH_RCV_TRAILER_ELEMENTS(MACH_RCV_TRAILER_AV)){
#if CONFIG_MACF_MACH
		  if (kmsg->ikm_sender != NULL &&
		    IP_VALID(kmsg->ikm_header->msgh_remote_port) &&
		    mac_port_check_method(kmsg->ikm_sender,
		    &kmsg->ikm_sender->maclabel,
		    &kmsg->ikm_header->msgh_remote_port->ip_label,
		    kmsg->ikm_header->msgh_id) == 0)
		      trailer->msgh_ad = 1;
		  else
#endif
		      trailer->msgh_ad = 0;
		}

		/*
		 * The ipc_kmsg_t holds a reference to the label of a label
		 * handle, not the port. We must get a reference to the port
		 * and a send right to copyout to the receiver.
		 */

		if (option & MACH_RCV_TRAILER_ELEMENTS (MACH_RCV_TRAILER_LABELS)) {
#if CONFIG_MACF_MACH
		  if (kmsg->ikm_sender != NULL) {
		    ipc_labelh_t  lh = kmsg->ikm_sender->label;
		    kern_return_t kr;

		    ip_lock(lh->lh_port);
		    lh->lh_port->ip_mscount++;
		    lh->lh_port->ip_srights++;
		    ip_reference(lh->lh_port);
		    ip_unlock(lh->lh_port);

		    kr = ipc_object_copyout(space, (ipc_object_t)lh->lh_port,
					    MACH_MSG_TYPE_PORT_SEND, 0,
					    &trailer->msgh_labels.sender);
		    if (kr != KERN_SUCCESS) {
		      ip_lock(lh->lh_port);
		      ip_release(lh->lh_port);
		      ip_check_unlock(lh->lh_port);

		      trailer->msgh_labels.sender = 0;
		    }
		  } else {
		    trailer->msgh_labels.sender = 0;
		  }
#else
		    trailer->msgh_labels.sender = 0;
#endif
		}
	}

	/*
	 * If MACH_RCV_OVERWRITE was specified, try to get the scatter
	 * list and verify it against the contents of the message.  If
	 * there is any problem with it, we will continue without it as
	 * normal.
	 */
	if (option & MACH_RCV_OVERWRITE) {
		mach_msg_size_t slist_size = self->ith_scatter_list_size;
		mach_msg_body_t *slist;

		slist = ipc_kmsg_get_scatter(msg_addr, slist_size, kmsg);
		mr = ipc_kmsg_copyout(kmsg, space, map, MACH_PORT_NULL, slist);
		ipc_kmsg_free_scatter(slist, slist_size);
	} else {
		mr = ipc_kmsg_copyout(kmsg, space, map,
				      MACH_PORT_NULL, MACH_MSG_BODY_NULL);
	}

	if (mr != MACH_MSG_SUCCESS) {
		if ((mr &~ MACH_MSG_MASK) == MACH_RCV_BODY_ERROR) {
			if (ipc_kmsg_put(msg_addr, kmsg, kmsg->ikm_header->msgh_size +
			   trailer->msgh_trailer_size) == MACH_RCV_INVALID_DATA)
				mr = MACH_RCV_INVALID_DATA;
		} 
		else {
			if (msg_receive_error(kmsg, msg_addr, option, seqno, space) 
						== MACH_RCV_INVALID_DATA)
				mr = MACH_RCV_INVALID_DATA;
		}
		goto out;
	}
	mr = ipc_kmsg_put(msg_addr,
			  kmsg,
			  kmsg->ikm_header->msgh_size + 
			  trailer->msgh_trailer_size);
 out:
	return mr;
}

mach_msg_return_t
mach_msg_receive(
	mach_msg_header_t	*msg,
	mach_msg_option_t	option,
	mach_msg_size_t		rcv_size,
	mach_port_name_t	rcv_name,
	mach_msg_timeout_t	rcv_timeout,
	void			(*continuation)(mach_msg_return_t),
	mach_msg_size_t		slist_size)
{
	thread_t self = current_thread();
	ipc_space_t space = current_space();
	ipc_object_t object;
	ipc_mqueue_t mqueue;
	mach_msg_return_t mr;

	mr = ipc_mqueue_copyin(space, rcv_name, &mqueue, &object);
 	if (mr != MACH_MSG_SUCCESS) {
		return mr;
	}
	/* hold ref for object */

	self->ith_msg_addr = CAST_DOWN(mach_vm_address_t, msg);
	self->ith_object = object;
	self->ith_msize = rcv_size;
	self->ith_option = option;
	self->ith_scatter_list_size = slist_size;
	self->ith_continuation = continuation;

	ipc_mqueue_receive(mqueue, option, rcv_size, rcv_timeout, THREAD_ABORTSAFE);
	if ((option & MACH_RCV_TIMEOUT) && rcv_timeout == 0)
		thread_poll_yield(self);
	return mach_msg_receive_results();
}

void
mach_msg_receive_continue(void)
{
	thread_t self = current_thread();

	(*self->ith_continuation)(mach_msg_receive_results());
}


/*
 *	Routine:	mach_msg_overwrite_trap [mach trap]
 *	Purpose:
 *		Possibly send a message; possibly receive a message.
 *	Conditions:
 *		Nothing locked.
 *	Returns:
 *		All of mach_msg_send and mach_msg_receive error codes.
 */

mach_msg_return_t
mach_msg_overwrite_trap(
	struct mach_msg_overwrite_trap_args *args)
{
  	mach_vm_address_t	msg_addr = args->msg;
	mach_msg_option_t	option = args->option;
	mach_msg_size_t		send_size = args->send_size;
	mach_msg_size_t		rcv_size = args->rcv_size;
	mach_port_name_t	rcv_name = args->rcv_name;
	mach_msg_timeout_t	msg_timeout = args->timeout;
	mach_port_name_t	notify = args->notify;
	mach_vm_address_t	rcv_msg_addr = args->rcv_msg;
        mach_msg_size_t		scatter_list_size = 0; /* NOT INITIALIZED - but not used in pactice */
	__unused mach_port_seqno_t temp_seqno = 0;

	mach_msg_return_t  mr = MACH_MSG_SUCCESS;
	vm_map_t map = current_map();
	
	if (option & MACH_SEND_MSG) {
		ipc_space_t space = current_space();
		ipc_kmsg_t kmsg;

		mr = ipc_kmsg_get(msg_addr, send_size, &kmsg);

		if (mr != MACH_MSG_SUCCESS)
			return mr;

		if (option & MACH_SEND_CANCEL) {
			if (notify == MACH_PORT_NULL)
				mr = MACH_SEND_INVALID_NOTIFY;
			else
				mr = ipc_kmsg_copyin(kmsg, space, map, notify);
		} else
			mr = ipc_kmsg_copyin(kmsg, space, map, MACH_PORT_NULL);
		if (mr != MACH_MSG_SUCCESS) {
			ipc_kmsg_free(kmsg);
			return mr;
		}

		mr = ipc_kmsg_send(kmsg, option & MACH_SEND_TIMEOUT, msg_timeout);

		if (mr != MACH_MSG_SUCCESS) {
			mr |= ipc_kmsg_copyout_pseudo(kmsg, space, map, MACH_MSG_BODY_NULL);
			(void) ipc_kmsg_put(msg_addr, kmsg, kmsg->ikm_header->msgh_size);
			return mr;
		}

	}

	if (option & MACH_RCV_MSG) {
		thread_t self = current_thread();
		ipc_space_t space = current_space();
		ipc_object_t object;
		ipc_mqueue_t mqueue;

		mr = ipc_mqueue_copyin(space, rcv_name, &mqueue, &object);
		if (mr != MACH_MSG_SUCCESS) {
			return mr;
		}
		/* hold ref for object */

		/*
		 * 1. MACH_RCV_OVERWRITE is on, and rcv_msg is our scatter list
		 *    and receive buffer
		 * 2. MACH_RCV_OVERWRITE is off, and rcv_msg might be the
		 *    alternate receive buffer (separate send and receive buffers).
		 */
		if (option & MACH_RCV_OVERWRITE) 
			self->ith_msg_addr = rcv_msg_addr;
		else if (rcv_msg_addr != (mach_vm_address_t)0)
			self->ith_msg_addr = rcv_msg_addr;
		else
			self->ith_msg_addr = msg_addr;
		self->ith_object = object;
		self->ith_msize = rcv_size;
		self->ith_option = option;
		self->ith_scatter_list_size = scatter_list_size;
		self->ith_receiver_name = MACH_PORT_NULL;
		self->ith_continuation = thread_syscall_return;

		ipc_mqueue_receive(mqueue, option, rcv_size, msg_timeout, THREAD_ABORTSAFE);
		if ((option & MACH_RCV_TIMEOUT) && msg_timeout == 0)
			thread_poll_yield(self);
		return mach_msg_receive_results();
	}

	return MACH_MSG_SUCCESS;
}

/*
 *	Routine:	mach_msg_trap [mach trap]
 *	Purpose:
 *		Possibly send a message; possibly receive a message.
 *	Conditions:
 *		Nothing locked.
 *	Returns:
 *		All of mach_msg_send and mach_msg_receive error codes.
 */

mach_msg_return_t
mach_msg_trap(
	struct mach_msg_overwrite_trap_args *args)
{
	kern_return_t kr;
	args->rcv_msg = (mach_vm_address_t)0;

 	kr = mach_msg_overwrite_trap(args);
	return kr;
}
 

/*
 *	Routine:	msg_receive_error	[internal]
 *	Purpose:
 *		Builds a minimal header/trailer and copies it to
 *		the user message buffer.  Invoked when in the case of a
 *		MACH_RCV_TOO_LARGE or MACH_RCV_BODY_ERROR error.
 *	Conditions:
 *		Nothing locked.
 *	Returns:
 *		MACH_MSG_SUCCESS	minimal header/trailer copied
 *		MACH_RCV_INVALID_DATA	copyout to user buffer failed
 */
	
mach_msg_return_t
msg_receive_error(
	ipc_kmsg_t		kmsg,
	mach_vm_address_t	msg_addr,
	mach_msg_option_t	option,
	mach_port_seqno_t	seqno,
	ipc_space_t		space)
{
	mach_msg_max_trailer_t *trailer;
	mach_vm_address_t	context;

	context = kmsg->ikm_header->msgh_remote_port->ip_context;

	/*
	 * Copy out the destination port in the message.
 	 * Destroy all other rights and memory in the message.
	 */
	ipc_kmsg_copyout_dest(kmsg, space);

	/*
	 * Build a minimal message with the requested trailer.
	 */
	trailer = (mach_msg_max_trailer_t *) 
			((vm_offset_t)kmsg->ikm_header +
			round_msg(sizeof(mach_msg_header_t)));
	kmsg->ikm_header->msgh_size = sizeof(mach_msg_header_t);
	bcopy(  (char *)&trailer_template, 
		(char *)trailer, 
		sizeof(trailer_template));
	if (option & MACH_RCV_TRAILER_MASK) {
		trailer->msgh_context = context; 
		trailer->msgh_seqno = seqno;
		trailer->msgh_trailer_size = REQUESTED_TRAILER_SIZE(option);
	}

	/*
	 * Copy the message to user space
	 */
	if (ipc_kmsg_put(msg_addr, kmsg, kmsg->ikm_header->msgh_size +
			trailer->msgh_trailer_size) == MACH_RCV_INVALID_DATA)
		return(MACH_RCV_INVALID_DATA);
	else 
		return(MACH_MSG_SUCCESS);
}