/*
 * Copyright (c) 2000-2016 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:	kern/ipc_kobject.c
 *	Author:	Rich Draves
 *	Date:	1989
 *
 *	Functions for letting a port represent a kernel object.
 */

#include <mach_debug.h>
#include <mach_ipc_test.h>
#include <mach/mig.h>
#include <mach/port.h>
#include <mach/kern_return.h>
#include <mach/message.h>
#include <mach/mig_errors.h>
#include <mach/notify.h>
#include <mach/ndr.h>
#include <mach/vm_param.h>

#include <mach/mach_vm_server.h>
#include <mach/mach_port_server.h>
#include <mach/mach_host_server.h>
#include <mach/host_priv_server.h>
#include <mach/host_security_server.h>
#include <mach/clock_server.h>
#include <mach/clock_priv_server.h>
#include <mach/lock_set_server.h>
#include <mach/memory_object_control_server.h>
#include <mach/memory_object_default_server.h>
#include <mach/processor_server.h>
#include <mach/processor_set_server.h>
#include <mach/task_server.h>
#include <mach/mach_voucher_server.h>
#include <mach/mach_voucher_attr_control_server.h>
#ifdef VM32_SUPPORT
#include <mach/vm32_map_server.h>
#endif
#include <mach/thread_act_server.h>

#include <device/device_types.h>
#include <device/device_server.h>

#include <UserNotification/UNDReplyServer.h>

#if	CONFIG_AUDIT
#include <kern/audit_sessionport.h>
#endif

#if     MACH_MACHINE_ROUTINES
#include <machine/machine_routines.h>
#endif	/* MACH_MACHINE_ROUTINES */
#if	XK_PROXY
#include <uk_xkern/xk_uproxy_server.h>
#endif	/* XK_PROXY */

#include <kern/ipc_tt.h>
#include <kern/ipc_mig.h>
#include <kern/ipc_misc.h>
#include <kern/ipc_kobject.h>
#include <kern/host_notify.h>
#include <kern/mk_timer.h>
#include <kern/misc_protos.h>
#include <ipc/ipc_kmsg.h>
#include <ipc/ipc_port.h>
#include <ipc/ipc_voucher.h>
#include <kern/sync_sema.h>
#include <kern/counters.h>
#include <kern/work_interval.h>

#include <vm/vm_protos.h>

#include <security/mac_mach_internal.h>

extern char *proc_name_address(void *p);
extern int proc_pid(void *p);

/*
 *	Routine:	ipc_kobject_notify
 *	Purpose:
 *		Deliver notifications to kobjects that care about them.
 */
boolean_t
ipc_kobject_notify(
        mach_msg_header_t *request_header,
        mach_msg_header_t *reply_header);

typedef struct {
        mach_msg_id_t num;
        mig_routine_t routine;
	int size;
#if	MACH_COUNTERS
	mach_counter_t callcount;
#endif
} mig_hash_t;

#define MAX_MIG_ENTRIES 1031
#define MIG_HASH(x) (x)

#ifndef max
#define max(a,b)        (((a) > (b)) ? (a) : (b))
#endif /* max */

static mig_hash_t mig_buckets[MAX_MIG_ENTRIES];
static int mig_table_max_displ;
static mach_msg_size_t mig_reply_size = sizeof(mig_reply_error_t);



const struct mig_subsystem *mig_e[] = {
        (const struct mig_subsystem *)&mach_vm_subsystem,
        (const struct mig_subsystem *)&mach_port_subsystem,
        (const struct mig_subsystem *)&mach_host_subsystem,
        (const struct mig_subsystem *)&host_priv_subsystem,
        (const struct mig_subsystem *)&host_security_subsystem,
        (const struct mig_subsystem *)&clock_subsystem,
        (const struct mig_subsystem *)&clock_priv_subsystem,
        (const struct mig_subsystem *)&processor_subsystem,
        (const struct mig_subsystem *)&processor_set_subsystem,
        (const struct mig_subsystem *)&is_iokit_subsystem,
	(const struct mig_subsystem *)&lock_set_subsystem,
	(const struct mig_subsystem *)&task_subsystem,
	(const struct mig_subsystem *)&thread_act_subsystem,
#ifdef VM32_SUPPORT
	(const struct mig_subsystem *)&vm32_map_subsystem,
#endif
	(const struct mig_subsystem *)&UNDReply_subsystem,
	(const struct mig_subsystem *)&mach_voucher_subsystem,
	(const struct mig_subsystem *)&mach_voucher_attr_control_subsystem,

#if     XK_PROXY
        (const struct mig_subsystem *)&do_uproxy_xk_uproxy_subsystem,
#endif /* XK_PROXY */
#if     MACH_MACHINE_ROUTINES
        (const struct mig_subsystem *)&MACHINE_SUBSYSTEM,
#endif  /* MACH_MACHINE_ROUTINES */
#if     MCMSG && iPSC860
	(const struct mig_subsystem *)&mcmsg_info_subsystem,
#endif  /* MCMSG && iPSC860 */
};

void
mig_init(void)
{
    unsigned int i, n = sizeof(mig_e)/sizeof(const struct mig_subsystem *);
    int howmany;
    mach_msg_id_t j, pos, nentry, range;
	
    for (i = 0; i < n; i++) {
	range = mig_e[i]->end - mig_e[i]->start;
	if (!mig_e[i]->start || range < 0)
	    panic("the msgh_ids in mig_e[] aren't valid!");

	for  (j = 0; j < range; j++) {
	  if (mig_e[i]->routine[j].stub_routine) { 
	    /* Only put real entries in the table */
	    nentry = j + mig_e[i]->start;	
	    for (pos = MIG_HASH(nentry) % MAX_MIG_ENTRIES, howmany = 1;
		 mig_buckets[pos].num;
		 pos++, pos = pos % MAX_MIG_ENTRIES, howmany++) {
	         if (mig_buckets[pos].num == nentry) {
		        printf("message id = %d\n", nentry);
		 	panic("multiple entries with the same msgh_id");
	         }
		 if (howmany == MAX_MIG_ENTRIES)
		       panic("the mig dispatch table is too small");
	    }
		
	    mig_buckets[pos].num = nentry;
	    mig_buckets[pos].routine = mig_e[i]->routine[j].stub_routine;
	    if (mig_e[i]->routine[j].max_reply_msg)
		    mig_buckets[pos].size = mig_e[i]->routine[j].max_reply_msg;
	    else
		    mig_buckets[pos].size = mig_e[i]->maxsize;

	    mig_table_max_displ = max(howmany, mig_table_max_displ);
	  }
	}
    }
    printf("mig_table_max_displ = %d\n", mig_table_max_displ);
}


/*
 *	Routine:	ipc_kobject_server
 *	Purpose:
 *		Handle a message sent to the kernel.
 *		Generates a reply message.
 *		Version for Untyped IPC.
 *	Conditions:
 *		Nothing locked.
 */

ipc_kmsg_t
ipc_kobject_server(
	ipc_kmsg_t	request,
	mach_msg_option_t __unused option)
{
	mach_msg_size_t reply_size;
	ipc_kmsg_t reply;
	kern_return_t kr;
	ipc_port_t *destp;
	ipc_port_t  replyp = IPC_PORT_NULL;
	mach_msg_format_0_trailer_t *trailer;
	mig_hash_t *ptr;
	task_t task = TASK_NULL;
	uint32_t exec_token;
	boolean_t exec_token_changed = FALSE;

	/*
	 * Find out corresponding mig_hash entry if any
	 */
	{
	    int key = request->ikm_header->msgh_id;
	    unsigned int i = (unsigned int)MIG_HASH(key);
	    int max_iter = mig_table_max_displ;

	    do {
		ptr = &mig_buckets[i++ % MAX_MIG_ENTRIES];
	    } while (key != ptr->num && ptr->num && --max_iter);

	    if (!ptr->routine || key != ptr->num) {
	        ptr = (mig_hash_t *)0;
		reply_size = mig_reply_size;
	    } else {
		reply_size = ptr->size;
#if	MACH_COUNTER
		ptr->callcount++;
#endif
	    }
	}

	/* round up for trailer size */
        reply_size += MAX_TRAILER_SIZE;
	reply = ipc_kmsg_alloc(reply_size);

	if (reply == IKM_NULL) {
		printf("ipc_kobject_server: dropping request\n");
		ipc_kmsg_trace_send(request, option);
		ipc_kmsg_destroy(request);
		return IKM_NULL;
	}

	/*
	 * Initialize reply message.
	 */
	{
#define	InP	((mach_msg_header_t *) request->ikm_header)
#define	OutP	((mig_reply_error_t *) reply->ikm_header)

	    /* 
	     * MIG should really assure no data leakage -
	     * but until it does, pessimistically zero the
	     * whole reply buffer.
	     */
	    bzero((void *)OutP, reply_size);

	    OutP->NDR = NDR_record;
	    OutP->Head.msgh_size = sizeof(mig_reply_error_t);

	    OutP->Head.msgh_bits =
		MACH_MSGH_BITS_SET(MACH_MSGH_BITS_LOCAL(InP->msgh_bits), 0, 0, 0);
	    OutP->Head.msgh_remote_port = InP->msgh_local_port;
	    OutP->Head.msgh_local_port = MACH_PORT_NULL;
	    OutP->Head.msgh_voucher_port = MACH_PORT_NULL;
	    OutP->Head.msgh_id = InP->msgh_id + 100;

#undef	InP
#undef	OutP
	}

	/*
	 * Find the routine to call, and call it
	 * to perform the kernel function
	 */
	ipc_kmsg_trace_send(request, option);
	{
	    if (ptr) {
		/*
		 * Check if the port is a task port, if its a task port then
		 * snapshot the task exec token before the mig routine call.
		 */
		ipc_port_t port = request->ikm_header->msgh_remote_port;
		if (IP_VALID(port) && ip_kotype(port) == IKOT_TASK) {
			task = convert_port_to_task_with_exec_token(port, &exec_token);
		}

		(*ptr->routine)(request->ikm_header, reply->ikm_header);

		/* Check if the exec token changed during the mig routine */
		if (task != TASK_NULL) {
			if (exec_token != task->exec_token) {
				exec_token_changed = TRUE;
			}
			task_deallocate(task);
		}

		kernel_task->messages_received++;
	    }
	    else {
		if (!ipc_kobject_notify(request->ikm_header, reply->ikm_header)){
#if DEVELOPMENT || DEBUG
		    printf("ipc_kobject_server: bogus kernel message, id=%d\n",
			request->ikm_header->msgh_id);
#endif	/* DEVELOPMENT || DEBUG */
		    _MIG_MSGID_INVALID(request->ikm_header->msgh_id);

		    ((mig_reply_error_t *) reply->ikm_header)->RetCode
			= MIG_BAD_ID;
		}
		else
		  kernel_task->messages_received++;
	    }
	    kernel_task->messages_sent++;
	}

	/*
	 *	Destroy destination. The following code differs from
	 *	ipc_object_destroy in that we release the send-once
	 *	right instead of generating a send-once notification
	 * 	(which would bring us here again, creating a loop).
	 *	It also differs in that we only expect send or
	 *	send-once rights, never receive rights.
	 *
	 *	We set msgh_remote_port to IP_NULL so that the kmsg
	 *	destroy routines don't try to destroy the port twice.
	 */
	destp = (ipc_port_t *) &request->ikm_header->msgh_remote_port;
	switch (MACH_MSGH_BITS_REMOTE(request->ikm_header->msgh_bits)) {
		case MACH_MSG_TYPE_PORT_SEND:
		    ipc_port_release_send(*destp);
		    break;
		
		case MACH_MSG_TYPE_PORT_SEND_ONCE:
		    ipc_port_release_sonce(*destp);
		    break;
		
		default:
		    panic("ipc_kobject_server: strange destination rights");
	}
	*destp = IP_NULL;

	/*
	 *	Destroy voucher.  The kernel MIG servers never take ownership
	 *	of vouchers sent in messages.  Swallow any such rights here.
	 */
	if (IP_VALID(request->ikm_voucher)) {
		assert(MACH_MSG_TYPE_PORT_SEND ==
		       MACH_MSGH_BITS_VOUCHER(request->ikm_header->msgh_bits));
		ipc_port_release_send(request->ikm_voucher);
		request->ikm_voucher = IP_NULL;
	}

        if (!(reply->ikm_header->msgh_bits & MACH_MSGH_BITS_COMPLEX) &&
           ((mig_reply_error_t *) reply->ikm_header)->RetCode != KERN_SUCCESS)
	 	kr = ((mig_reply_error_t *) reply->ikm_header)->RetCode;
	else
		kr = KERN_SUCCESS;

	if ((kr == KERN_SUCCESS) || (kr == MIG_NO_REPLY)) {
		/*
		 *	The server function is responsible for the contents
		 *	of the message.  The reply port right is moved
		 *	to the reply message, and we have deallocated
		 *	the destination port right, so we just need
		 *	to free the kmsg.
		 */
		ipc_kmsg_free(request);

	} else {
		/*
		 *	The message contents of the request are intact.
		 *	Destroy everthing except the reply port right,
		 *	which is needed in the reply message.
		 */
		request->ikm_header->msgh_local_port = MACH_PORT_NULL;
		ipc_kmsg_destroy(request);
	}

	replyp = (ipc_port_t)reply->ikm_header->msgh_remote_port;

	if (kr == MIG_NO_REPLY) {
		/*
		 *	The server function will send a reply message
		 *	using the reply port right, which it has saved.
		 */

		ipc_kmsg_free(reply);

		return IKM_NULL;
	} else if (!IP_VALID(replyp)) {
		/*
		 *	Can't queue the reply message if the destination
		 *	(the reply port) isn't valid.
		 */

		ipc_kmsg_destroy(reply);

		return IKM_NULL;
	} else if (replyp->ip_receiver == ipc_space_kernel) {
		/*
		 * Don't send replies to kobject kernel ports
		 */
#if DEVELOPMENT || DEBUG
		printf("%s: refusing to send reply to kobject %d port (id:%d)\n",
		       __func__, ip_kotype(replyp),
		       request->ikm_header->msgh_id);
#endif	/* DEVELOPMENT || DEBUG */
		ipc_kmsg_destroy(reply);
		return IKM_NULL;
	}

	/* Fail the MIG call if the task exec token changed during the call */
	if (kr == KERN_SUCCESS && exec_token_changed) {
		/*
		 *	Create a new reply msg with error and destroy the old reply msg.
		 */
		ipc_kmsg_t new_reply = ipc_kmsg_alloc(reply_size);

		if (new_reply == IKM_NULL) {
			printf("ipc_kobject_server: dropping request\n");
			ipc_kmsg_destroy(reply);
			return IKM_NULL;
		}
		/*
		 *	Initialize the new reply message.
		 */
		{
#define	OutP_new	((mig_reply_error_t *) new_reply->ikm_header)
#define	OutP_old	((mig_reply_error_t *) reply->ikm_header)

		    bzero((void *)OutP_new, reply_size);

		    OutP_new->NDR = OutP_old->NDR;
		    OutP_new->Head.msgh_size = sizeof(mig_reply_error_t);
		    OutP_new->Head.msgh_bits = OutP_old->Head.msgh_bits & ~MACH_MSGH_BITS_COMPLEX;
		    OutP_new->Head.msgh_remote_port = OutP_old->Head.msgh_remote_port;
		    OutP_new->Head.msgh_local_port = MACH_PORT_NULL;
		    OutP_new->Head.msgh_voucher_port = MACH_PORT_NULL;
		    OutP_new->Head.msgh_id = OutP_old->Head.msgh_id;

		    /* Set the error as KERN_INVALID_TASK */
		    OutP_new->RetCode = KERN_INVALID_TASK;

#undef	OutP_new
#undef  OutP_old
		}

		/*
		 *	Destroy everything in reply except the reply port right,
		 *	which is needed in the new reply message.
		 */
		reply->ikm_header->msgh_remote_port = MACH_PORT_NULL;
		ipc_kmsg_destroy(reply);

		reply = new_reply;
	}

 	trailer = (mach_msg_format_0_trailer_t *)
		((vm_offset_t)reply->ikm_header + (int)reply->ikm_header->msgh_size);

 	trailer->msgh_sender = KERNEL_SECURITY_TOKEN;
 	trailer->msgh_trailer_type = MACH_MSG_TRAILER_FORMAT_0;
 	trailer->msgh_trailer_size = MACH_MSG_TRAILER_MINIMUM_SIZE;

	return reply;
}

/*
 *	Routine:	ipc_kobject_set
 *	Purpose:
 *		Make a port represent a kernel object of the given type.
 *		The caller is responsible for handling refs for the
 *		kernel object, if necessary.
 *	Conditions:
 *		Nothing locked.  The port must be active if setting
 *		a kobject linkage.  Clearing a linkage is OK on an
 *		inactive port.
 */
void
ipc_kobject_set(
	ipc_port_t			port,
	ipc_kobject_t		kobject,
	ipc_kobject_type_t	type)
{
	ip_lock(port);
	ipc_kobject_set_atomically(port, kobject, type);
	ip_unlock(port);
}

void
ipc_kobject_set_atomically(
	ipc_port_t			port,
	ipc_kobject_t		kobject,
	ipc_kobject_type_t	type)
{
	assert(type == IKOT_NONE || ip_active(port));
#if	MACH_ASSERT
	port->ip_spares[2] = (port->ip_bits & IO_BITS_KOTYPE);
#endif	/* MACH_ASSERT */
	port->ip_bits = (port->ip_bits &~ IO_BITS_KOTYPE) | type;
	port->ip_kobject = kobject;
}

/*
 *	Routine:	ipc_kobject_destroy
 *	Purpose:
 *		Release any kernel object resources associated
 *		with the port, which is being destroyed.
 *
 *		This should only be needed when resources are
 *		associated with a user's port.  In the normal case,
 *		when the kernel is the receiver, the code calling
 *		ipc_port_dealloc_kernel should clean up the resources.
 *	Conditions:
 *		The port is not locked, but it is dead.
 */

void
ipc_kobject_destroy(
	ipc_port_t		port)
{
	switch (ip_kotype(port)) {

	case IKOT_TIMER:
		mk_timer_port_destroy(port);
		break;

	case IKOT_NAMED_ENTRY:
		mach_destroy_memory_entry(port);
		break;

	case IKOT_HOST_NOTIFY:
		host_notify_port_destroy(port);
		break;

	default:
		break;
	}
}


boolean_t
ipc_kobject_notify(
	mach_msg_header_t *request_header,
	mach_msg_header_t *reply_header)
{
	mach_msg_max_trailer_t * trailer;
	ipc_port_t port = (ipc_port_t) request_header->msgh_remote_port;

	((mig_reply_error_t *) reply_header)->RetCode = MIG_NO_REPLY;

	trailer = (mach_msg_max_trailer_t *)
	          ((vm_offset_t)request_header + request_header->msgh_size);

	/*
	 * The kobject notification is privileged and can change the
	 * refcount on kernel-internal objects - make sure
	 * that the message wasn't faked!
	 */
	if (0 != bcmp(&trailer->msgh_audit, &KERNEL_AUDIT_TOKEN,
			sizeof(trailer->msgh_audit))) {
		return FALSE;
	}
	if (0 != bcmp(&trailer->msgh_sender, &KERNEL_SECURITY_TOKEN,
			sizeof(trailer->msgh_sender))) {
		return FALSE;
	}

	switch (request_header->msgh_id) {
		case MACH_NOTIFY_NO_SENDERS:
			switch (ip_kotype(port)) {
			case IKOT_VOUCHER:
				ipc_voucher_notify(request_header);
				return TRUE;

			case IKOT_VOUCHER_ATTR_CONTROL:
				ipc_voucher_attr_control_notify(request_header);
				return TRUE;

			case IKOT_SEMAPHORE:
				semaphore_notify(request_header);
				return TRUE;

			case IKOT_TASK:
				task_port_notify(request_header);
				return TRUE;
				
			case IKOT_NAMED_ENTRY:
				ip_lock(port);

				/*
				 * Bring the sequence number and mscount in
				 * line with ipc_port_destroy assertion.
				 */
				port->ip_mscount = 0;
				port->ip_messages.imq_seqno = 0;
				ipc_port_destroy(port); /* releases lock */
				return TRUE;

			case IKOT_UPL:
				upl_no_senders(
					request_header->msgh_remote_port, 
					(mach_port_mscount_t) 
					((mach_no_senders_notification_t *) 
					 request_header)->not_count);
				reply_header->msgh_remote_port = MACH_PORT_NULL;
				return TRUE;

#if	CONFIG_AUDIT
			case IKOT_AU_SESSIONPORT:
				audit_session_nosenders(request_header);
				return TRUE;
#endif
			case IKOT_FILEPORT:
				fileport_notify(request_header);
				return TRUE;

			case IKOT_WORK_INTERVAL:
				work_interval_port_notify(request_header);
				return TRUE;

			}
		break;

		case MACH_NOTIFY_PORT_DELETED:
		case MACH_NOTIFY_PORT_DESTROYED:
		case MACH_NOTIFY_SEND_ONCE:
		case MACH_NOTIFY_DEAD_NAME:
		break;

		default:
		return FALSE;
	}
	switch (ip_kotype(port)) {

#ifdef IOKIT
		case IKOT_IOKIT_OBJECT:
		case IKOT_IOKIT_CONNECT:
		case IKOT_IOKIT_IDENT:
		{
                return iokit_notify(request_header);
		}
#endif
		case IKOT_TASK_RESUME:
		{
			return task_suspension_notify(request_header);
		}

		default:
                return FALSE;
        }
}