/*
* Copyright (c) 2003,2008,2017 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@
*/
/*!
* @header kpi_interfacefilter.h
* This header defines an API to attach interface filters. Interface
* filters may be attached to a specific interface. The filters can
* intercept all packets in to and out of the specific interface. In
* addition, the filters may intercept interface specific events and
* ioctls.
*/
#ifndef __KPI_INTERFACEFILTER__
#define __KPI_INTERFACEFILTER__
#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 */
struct kev_msg;
__BEGIN_DECLS
/*!
* @typedef iff_input_func
*
* @discussion iff_input_func is used to filter incoming packets. The
* interface is only valid for the duration of the filter call. If
* you need to keep a reference to the interface, be sure to call
* ifnet_reference and ifnet_release. The packets passed to the
* inbound filter are different from those passed to the outbound
* filter. Packets to the inbound filter have the frame header
* passed in separately from the rest of the packet. The outbound
* data filters is passed the whole packet including the frame
* header.
*
* The frame header usually preceeds the data in the mbuf. This
* ensures that the frame header will be a valid pointer as long as
* the mbuf is not freed. If you need to change the frame header to
* point somewhere else, the recommended method is to prepend a new
* frame header to the mbuf chain (mbuf_prepend), set the header to
* point to that data, then call mbuf_adj to move the mbuf data
* pointer back to the start of the packet payload.
* @param cookie The cookie specified when this filter was attached.
* @param interface The interface the packet was recieved on.
* @param protocol The protocol of this packet. If you specified a
* protocol when attaching your filter, the protocol will only ever
* be the protocol you specified.
* @param data The inbound packet, after the frame header as determined
* by the interface.
* @param frame_ptr A pointer to the pointer to the frame header. The
* frame header length can be found by inspecting the interface's
* frame header length (ifnet_hdrlen).
* @result Return:
* 0 - The caller will continue with normal processing of the
* packet.
* EJUSTRETURN - The caller will stop processing the packet,
* the packet will not be freed.
* Anything Else - The caller will free the packet and stop
* processing.
*/
typedef errno_t (*iff_input_func)(void *cookie, ifnet_t interface,
protocol_family_t protocol, mbuf_t *data, char **frame_ptr);
/*!
* @typedef iff_output_func
*
* @discussion iff_output_func is used to filter fully formed outbound
* packets. The interface is only valid for the duration of the
* filter call. If you need to keep a reference to the interface,
* be sure to call ifnet_reference and ifnet_release.
* @param cookie The cookie specified when this filter was attached.
* @param interface The interface the packet is being transmitted on.
* @param data The fully formed outbound packet in a chain of mbufs.
* The frame header is already included. The filter function may
* modify the packet or return a different mbuf chain.
* @result Return:
* 0 - The caller will continue with normal processing of the
* packet.
* EJUSTRETURN - The caller will stop processing the packet,
* the packet will not be freed.
* Anything Else - The caller will free the packet and stop
* processing.
*/
typedef errno_t (*iff_output_func)(void *cookie, ifnet_t interface,
protocol_family_t protocol, mbuf_t *data);
/*!
* @typedef iff_event_func
*
* @discussion iff_event_func is used to filter interface specific
* events. The interface is only valid for the duration of the
* filter call. If you need to keep a reference to the interface,
* be sure to call ifnet_reference and ifnet_release.
* @param cookie The cookie specified when this filter was attached.
* @param interface The interface the packet is being transmitted on.
* @param event_msg The kernel event, may not be changed.
*/
typedef void (*iff_event_func)(void *cookie, ifnet_t interface,
protocol_family_t protocol, const struct kev_msg *event_msg);
/*!
* @typedef iff_ioctl_func
*
* @discussion iff_ioctl_func is used to filter ioctls sent to an
* interface. The interface is only valid for the duration of the
* filter call. If you need to keep a reference to the interface,
* be sure to call ifnet_reference and ifnet_release.
*
* All undefined ioctls are reserved for future use by Apple. If
* you need to communicate with your kext using an ioctl, please
* use SIOCSIFKPI and SIOCGIFKPI.
* @param cookie The cookie specified when this filter was attached.
* @param interface The interface the packet is being transmitted on.
* @param ioctl_cmd The ioctl command.
* @param ioctl_arg A pointer to the ioctl argument.
* @result Return:
* 0 - This filter function handled the ioctl.
* EOPNOTSUPP - This filter function does not understand/did not
* handle this ioctl.
* EJUSTRETURN - This filter function handled the ioctl,
* processing should stop.
* Anything Else - Processing will stop, the error will be
* returned.
*/
typedef errno_t (*iff_ioctl_func)(void *cookie, ifnet_t interface,
protocol_family_t protocol, unsigned long ioctl_cmd, void *ioctl_arg);
/*!
* @typedef iff_detached_func
*
* @discussion iff_detached_func is called to notify the filter that it
* has been detached from an interface. This is the last call to
* the filter that will be made. A filter may be detached if the
* interface is detached or the detach filter function is called.
* In the case that the interface is being detached, your filter's
* event function will be called with the interface detaching event
* before the your detached function will be called.
* @param cookie The cookie specified when this filter was attached.
* @param interface The interface this filter was detached from.
*/
typedef void (*iff_detached_func)(void *cookie, ifnet_t interface);
/*!
* @struct iff_filter
* @discussion This structure is used to define an interface filter for
* use with the iflt_attach function.
* @field iff_cookie A kext defined cookie that will be passed to all
* filter functions.
* @field iff_name A filter name used for debugging purposes.
* @field iff_protocol The protocol of the packets this filter is
* interested in. If you specify zero, packets from all protocols
* will be passed to the filter.
* @field iff_input The filter function to handle inbound packets, may
* be NULL.
* @field iff_output The filter function to handle outbound packets,
* may be NULL.
* @field iff_event The filter function to handle interface events, may
* be null.
* @field iff_ioctl The filter function to handle interface ioctls, may
* be null.
* @field iff_detached The filter function used to notify the filter that
* it has been detached.
*/
struct iff_filter {
void *iff_cookie;
const char *iff_name;
protocol_family_t iff_protocol;
iff_input_func iff_input;
iff_output_func iff_output;
iff_event_func iff_event;
iff_ioctl_func iff_ioctl;
iff_detached_func iff_detached;
};
/*!
* @function iflt_attach
* @discussion Attaches an interface filter to an interface.
* @param interface The interface the filter should be attached to.
* @param filter A structure defining the filter.
* @param filter_ref A reference to the filter used to detach.
* @result 0 on success otherwise the errno error.
*/
#ifdef KERNEL_PRIVATE
extern errno_t iflt_attach_internal(ifnet_t interface, const struct iff_filter *filter,
interface_filter_t *filter_ref);
#define iflt_attach(interface, filter, filter_ref) \
iflt_attach_internal((interface), (filter), (filter_ref))
#else
extern errno_t iflt_attach(ifnet_t interface, const struct iff_filter *filter,
interface_filter_t *filter_ref)
__NKE_API_DEPRECATED;
#endif /* KERNEL_PRIVATE */
/*!
* @function iflt_detach
* @discussion Detaches an interface filter from an interface.
* @param filter_ref The reference to the filter from iflt_attach.
*/
extern void iflt_detach(interface_filter_t filter_ref)
__NKE_API_DEPRECATED;
__END_DECLS
#undef __NKE_API_DEPRECATED
#endif /* __KPI_INTERFACEFILTER__ */