/*
 * Copyright (c) 2000-2014 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@
 */
/* Copyright (c) 1998, 1999 Apple Computer, Inc. All Rights Reserved */
/*!
	@header kern_event.h
	This header defines in-kernel functions for generating kernel events as
	well as functions for receiving kernel events using a kernel event
	socket.
 */

#ifndef SYS_KERN_EVENT_H
#define	SYS_KERN_EVENT_H

#include <sys/appleapiopts.h>
#include <sys/ioccom.h>
#include <sys/sys_domain.h>

#define	KEV_SNDSPACE	(4 * 1024)
#define	KEV_RECVSPACE	(32 * 1024)

#define	KEV_ANY_VENDOR		0
#define	KEV_ANY_CLASS		0
#define	KEV_ANY_SUBCLASS	0

/*
 * Vendor Code
 */

/*!
	@defined KEV_VENDOR_APPLE
	@discussion Apple generated kernel events use the hard coded vendor code
	value of 1. Third party kernel events use a dynamically allocated vendor
	code. The vendor code can be found using the SIOCGKEVVENDOR ioctl.
*/
#define	KEV_VENDOR_APPLE	1

/*
 * Definition of top-level classifications for KEV_VENDOR_APPLE
 */

/*!
	@defined KEV_NETWORK_CLASS
	@discussion Network kernel event class.
 */
#define	KEV_NETWORK_CLASS	1

/*!
	@defined KEV_IOKIT_CLASS
	@discussion IOKit kernel event class.
 */
#define	KEV_IOKIT_CLASS		2

/*!
	@defined KEV_SYSTEM_CLASS
	@discussion System kernel event class.
 */
#define	KEV_SYSTEM_CLASS	3

/*!
	@defined KEV_APPLESHARE_CLASS
	@discussion AppleShare kernel event class.
 */
#define	KEV_APPLESHARE_CLASS	4

/*!
	@defined KEV_FIREWALL_CLASS
	@discussion Firewall kernel event class.
 */
#define	KEV_FIREWALL_CLASS	5

/*!
	@defined KEV_IEEE80211_CLASS
	@discussion IEEE 802.11 kernel event class.
 */
#define	KEV_IEEE80211_CLASS	6

/*!
	@struct kern_event_msg
	@discussion This structure is prepended to all kernel events. This
		structure is used to determine the format of the remainder of
		the kernel event. This structure will appear on all messages
		received on a kernel event socket. To post a kernel event, a
		slightly different structure is used.
	@field total_size Total size of the kernel event message including the
		header.
	@field vendor_code The vendor code indicates which vendor generated the
		kernel event. This gives every vendor a unique set of classes
		and subclasses to use. Use the SIOCGKEVVENDOR ioctl to look up
		vendor codes for vendors other than Apple. Apple uses
		KEV_VENDOR_APPLE.
	@field kev_class The class of the kernel event.
	@field kev_subclass The subclass of the kernel event.
	@field id Monotonically increasing value.
	@field event_code The event code.
	@field event_data Any additional data about this event. Format will
		depend on the vendor_code, kev_class, kev_subclass, and
		event_code. The length of the event_data can be determined
		using total_size - KEV_MSG_HEADER_SIZE.
 */
struct kern_event_msg {
	u_int32_t	total_size;	/* Size of entire event msg */
	u_int32_t	vendor_code;	/* For non-Apple extensibility */
	u_int32_t	kev_class;	/* Layer of event source */
	u_int32_t	kev_subclass;	/* Component within layer */
	u_int32_t	id;		/* Monotonically increasing value */
	u_int32_t	event_code;	/* unique code */
	u_int32_t	event_data[1];	/* One or more data words */
};

/*!
	@defined KEV_MSG_HEADER_SIZE
	@discussion Size of the header portion of the kern_event_msg structure.
		This accounts for everything right up to event_data. The size
		of the data can be found by subtracting KEV_MSG_HEADER_SIZE
		from the total size from the kern_event_msg.
 */
#define	KEV_MSG_HEADER_SIZE (offsetof(struct kern_event_msg, event_data[0]))

/*!
	@struct kev_request
	@discussion This structure is used with the SIOCSKEVFILT and
		SIOCGKEVFILT to set and get the control filter setting for a
		kernel control socket.
	@field total_size Total size of the kernel event message including the
		header.
	@field vendor_code All kernel events that don't match this vendor code
		will be ignored. KEV_ANY_VENDOR can be used to receive kernel
		events with any vendor code.
	@field kev_class All kernel events that don't match this class will be
		ignored. KEV_ANY_CLASS can be used to receive kernel events with
		any class.
	@field kev_subclass All kernel events that don't match this subclass
		will be ignored. KEV_ANY_SUBCLASS can be used to receive kernel
		events with any subclass.
 */
struct kev_request {
	u_int32_t	vendor_code;
	u_int32_t	kev_class;
	u_int32_t	kev_subclass;
};

/*!
	@defined KEV_VENDOR_CODE_MAX_STR_LEN
	@discussion This define sets the maximum length of a string that can be
		used to identify a vendor or kext when looking up a vendor code.
 */
#define	KEV_VENDOR_CODE_MAX_STR_LEN	200

/*!
	@struct kev_vendor_code
	@discussion This structure is used with the SIOCGKEVVENDOR ioctl to
		convert from a string identifying a kext or vendor, in the
		form of a bundle identifier, to a vendor code.
	@field vendor_code After making the SIOCGKEVVENDOR ioctl call, this will
		be filled in with the vendor code if there is one.
	@field vendor_string A bundle style identifier.
 */
#pragma pack(4)
struct kev_vendor_code {
	u_int32_t	vendor_code;
	char		vendor_string[KEV_VENDOR_CODE_MAX_STR_LEN];
};
#pragma pack()

/*!
	@defined SIOCGKEVID
	@discussion Retrieve the current event id. Each event generated will
		have a new id. The next event to be generated will have an id
		of id+1.
 */
#define	SIOCGKEVID	_IOR('e', 1, u_int32_t)

/*!
	@defined SIOCSKEVFILT
	@discussion Set the kernel event filter for this socket. Kernel events
		not matching this filter will not be received on this socket.
 */
#define	SIOCSKEVFILT	_IOW('e', 2, struct kev_request)

/*!
	@defined SIOCGKEVFILT
	@discussion Retrieve the kernel event filter for this socket. Kernel
		events not matching this filter will not be received on this
		socket.
 */
#define	SIOCGKEVFILT	_IOR('e', 3, struct kev_request)

/*!
	@defined SIOCGKEVVENDOR
	@discussion Lookup the vendor code for the specified vendor. ENOENT will
		be returned if a vendor code for that vendor string does not
		exist.
 */
#define	SIOCGKEVVENDOR	_IOWR('e', 4, struct kev_vendor_code)


/*!
	@define N_KEV_VECTORS
	@discussion The maximum number of kev_d_vectors for a kernel event.
 */
#define	N_KEV_VECTORS	5

/*!
	@struct kev_d_vectors
	@discussion This structure is used to append some data to a kernel
		event.
	@field data_length The length of data.
	@field data_ptr A pointer to data.
 */
struct kev_d_vectors {
	u_int32_t	data_length;	/* Length of the event data */
	void		*data_ptr;	/* Pointer to event data */
};

/*!
	@struct kev_msg
	@discussion This structure is used when posting a kernel event.
	@field vendor_code The vendor code assigned by kev_vendor_code_find.
	@field kev_class The event's class.
	@field kev_class The event's subclass.
	@field kev_class The event's code.
	@field dv An array of vectors describing additional data to be appended
		to the kernel event.
 */
struct kev_msg {
	u_int32_t vendor_code;		/* For non-Apple extensibility */
	u_int32_t kev_class;		/* Layer of event source */
	u_int32_t kev_subclass;		/* Component within layer */
	u_int32_t event_code;		/* The event code */
	struct kev_d_vectors dv[N_KEV_VECTORS];	/* Up to n data vectors */
};

/*!
	@function kev_vendor_code_find
	@discussion Lookup a vendor_code given a unique string. If the vendor
		code has not been used since launch, a unique integer will be
		assigned for that string. Vendor codes will remain the same
		until the machine is rebooted.
	@param vendor_string A bundle style vendor identifier(i.e. com.apple).
	@param vendor_code Upon return, a unique vendor code for use when
		posting kernel events.
	@result May return ENOMEM if memory constraints prevent allocation of a
		new vendor code.
 */
errno_t	kev_vendor_code_find(const char *vendor_string, u_int32_t *vendor_code);

/*!
	@function kev_msg_post
	@discussion Post a kernel event message.
	@param event_msg A structure defining the kernel event message to post.
	@result Will return zero upon success. May return a number of errors
		depending on the type of failure. EINVAL indicates that there
		was something wrong with the kerne event. The vendor code of
		the kernel event must be assigned using kev_vendor_code_find.
		If the message is too large, EMSGSIZE will be returned.
 */
errno_t kev_msg_post(struct kev_msg *event_msg);

#endif /* SYS_KERN_EVENT_H */
