/*
 * Copyright (c) 2008-2016 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@
 */
/*!
 *       @header kpi_protocol.h
 *       This header defines an API to interact with protocols in the kernel.
 *       The KPIs in this header file can be used to interact with protocols
 *       that already exist in the stack. These KPIs can be used to support
 *       existing protocols over media types that are not natively supported
 *       in the kernel, such as ATM.
 */

#ifndef __KPI_PROTOCOL__
#define __KPI_PROTOCOL__
#include <sys/kernel_types.h>
#include <net/kpi_interface.h>

#ifndef PRIVATE
#include <Availability.h>
#define __NKE_API_DEPRECATED __API_DEPRECATED("Network Kernel Extension KPI is deprecated", macos(10.4, 10.15.4))
#else
#define __NKE_API_DEPRECATED
#endif /* PRIVATE */

__BEGIN_DECLS

/******************************************************************************/
/* Protocol input/inject                                                      */
/******************************************************************************/

#ifdef BSD_KERNEL_PRIVATE
/*!
 *       @typedef protocol_input_handler
 *       @discussion protocol_input_handler is called to input a packet. If
 *               your protocol has specified a global lock, the lock will be held
 *               when this funciton is called.
 *       @pararm protocol The protocol this packet is intended for.
 *       @param packet The packet that should be input.
 */
typedef void (*proto_input_handler)(protocol_family_t protocol, mbuf_t packet);

/*!
 *       @typedef proto_input_detached_handler
 *       @discussion proto_input_detached_handler is called to notify the
 *               protocol that it has been detached. When this function is
 *               called, the proto_input_handler will not be called again, making
 *               it safe to unload.
 *       @pararm protocol The protocol detached.
 */
typedef void (*proto_input_detached_handler)(protocol_family_t protocol);

/*!
 *       @function proto_register_input
 *       @discussion Allows the caller to specify the functions called when a
 *               packet for a protocol is received.
 *       @param protocol The protocol family these functions will receive
 *               packets for.
 *       @param input The function called when a packet is input.
 *       @param chains Input function supports packet chains.
 *       @result A errno error on failure.
 */
extern errno_t proto_register_input(protocol_family_t protocol,
    proto_input_handler input, proto_input_detached_handler detached,
    int chains);

/*!
 *       @function proto_unregister_input
 *       @discussion Allows the caller to unregister the input and inject
 *               functions for a protocol. The input/inject functions may not be
 *               unregistered immediately if there is a chance they are in use.
 *               To notify the owner when the functions are no longer in use, the
 *               proto_detached_handler function will be called. It is not safe
 *               to unload until the proto_detached_handler is called.
 *       @param protocol The protocol family these functions will receive
 *               packets for.
 */
extern void proto_unregister_input(protocol_family_t protocol);
#endif /* BSD_KERNEL_PRIVATE */

/*!
 *       @function proto_input
 *       @discussion Inputs a packet on the specified protocol from the input
 *               path.
 *       @param protocol The protocol of the packet.
 *       @param packet The first packet in a chain of packets to be input.
 *       @result A errno error on failure. Unless proto_input returns zero,
 *               the caller is responsible for freeing the mbuf.
 */
extern errno_t proto_input(protocol_family_t protocol, mbuf_t packet)
__NKE_API_DEPRECATED;

/*!
 *       @function proto_inject
 *       @discussion Injects a packet on the specified protocol from
 *               anywhere. To avoid recursion, the protocol may need to queue the
 *               packet to be handled later.
 *       @param protocol The protocol of the packet.
 *       @param packet The first packet in a chain of packets to be injected.
 *       @result A errno error on failure. Unless proto_inject returns zero,
 *               the caller is responsible for freeing the mbuf.
 */
extern errno_t proto_inject(protocol_family_t protocol, mbuf_t packet)
__NKE_API_DEPRECATED;


/******************************************************************************/
/* Protocol plumbing                                                          */
/******************************************************************************/

/*!
 *       @typedef proto_plumb_handler
 *       @discussion proto_plumb_handler is called to attach a protocol to an
 *               interface. A typical protocol plumb function would fill out an
 *               ifnet_attach_proto_param and call ifnet_attach_protocol.
 *       @param ifp The interface the protocol should be attached to.
 *       @param protocol The protocol that should be attached to the
 *               interface.
 *       @result
 *               A non-zero value of the attach failed.
 */
typedef errno_t (*proto_plumb_handler)(ifnet_t ifp, protocol_family_t protocol);

/*!
 *       @typedef proto_unplumb_handler
 *       @discussion proto_unplumb_handler is called to detach a protocol
 *               from an interface. A typical unplumb function would call
 *               ifnet_detach_protocol and perform any necessary cleanup.
 *       @param ifp The interface the protocol should be detached from.
 *       @param protocol The protocol that should be detached from the
 *               interface.
 */
typedef void (*proto_unplumb_handler)(ifnet_t ifp, protocol_family_t protocol);

/*!
 *       @function proto_register_plumber
 *       @discussion Allows the caller to specify the functions called when a
 *               protocol is attached to an interface belonging to the specified
 *               family and when that protocol is detached.
 *       @param proto_fam The protocol family these plumbing functions will
 *               handle.
 *       @param if_fam The interface family these plumbing functions will
 *               handle.
 *       @param plumb The function to call to attach the protocol to an
 *               interface.
 *       @param unplumb The function to call to detach the protocol to an
 *               interface, may be NULL in which case ifnet_detach_protocol will
 *               be used to detach the protocol.
 *       @result A non-zero value of the attach failed.
 */
extern errno_t proto_register_plumber(protocol_family_t proto_fam,
    ifnet_family_t if_fam, proto_plumb_handler plumb,
    proto_unplumb_handler unplumb)
__NKE_API_DEPRECATED;

/*!
 *       @function proto_unregister_plumber
 *       @discussion Unregisters a previously registered plumbing function.
 *       @param proto_fam The protocol family these plumbing functions
 *               handle.
 *       @param if_fam The interface family these plumbing functions handle.
 */
extern void proto_unregister_plumber(protocol_family_t proto_fam,
    ifnet_family_t if_fam)
__NKE_API_DEPRECATED;

#ifdef BSD_KERNEL_PRIVATE
/*
 *       @function proto_plumb
 *       @discussion Plumbs a protocol to an actual interface.  This will find
 *               a registered protocol module and call its attach function.
 *               The module will typically call dlil_attach_protocol() with the
 *               appropriate parameters.
 *       @param protocol_family The protocol family.
 *       @param ifp The interface to plumb the protocol to.
 *       @result 0: No error.
 *               ENOENT: No module was registered.
 *               Other: Error returned by the attach_proto function
 */
extern errno_t proto_plumb(protocol_family_t protocol_family, ifnet_t ifp);

/*
 *       @function proto_unplumb
 *       @discussion Unplumbs a protocol from an interface.  This will find
 *               a registered protocol module and call its detach function.
 *               The module will typically call dlil_detach_protocol() with
 *               the appropriate parameters.  If no module is found, this
 *               function will call dlil_detach_protocol directly().
 *       @param protocol_family The protocol family.
 *       @param ifp The interface to unplumb the protocol from.
 *       @result 0: No error.
 *               ENOENT: No module was registered.
 *               Other: Error returned by the attach_proto function
 */
extern errno_t proto_unplumb(protocol_family_t protocol_family, ifnet_t ifp);

__private_extern__ void
proto_kpi_init(void);

#endif /* BSD_KERNEL_PRIVATE */
__END_DECLS

#undef __NKE_API_DEPRECATED
#endif /* __KPI_PROTOCOL__ */
