1/* 2 * Copyright (c) 2008 Apple Computer, Inc. All rights reserved. 3 * 4 * @APPLE_OSREFERENCE_LICENSE_HEADER_START@ 5 * 6 * This file contains Original Code and/or Modifications of Original Code 7 * as defined in and that are subject to the Apple Public Source License 8 * Version 2.0 (the 'License'). You may not use this file except in 9 * compliance with the License. The rights granted to you under the License 10 * may not be used to create, or enable the creation or redistribution of, 11 * unlawful or unlicensed copies of an Apple operating system, or to 12 * circumvent, violate, or enable the circumvention or violation of, any 13 * terms of an Apple operating system software license agreement. 14 * 15 * Please obtain a copy of the License at 16 * http://www.opensource.apple.com/apsl/ and read it before using this file. 17 * 18 * The Original Code and all software distributed under the License are 19 * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER 20 * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES, 21 * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY, 22 * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT. 23 * Please see the License for the specific language governing rights and 24 * limitations under the License. 25 * 26 * @APPLE_OSREFERENCE_LICENSE_HEADER_END@ 27 */ 28/*! 29 @header kpi_interfacefilter.h 30 This header defines an API to attach interface filters. Interface 31 filters may be attached to a specific interface. The filters can 32 intercept all packets in to and out of the specific interface. In 33 addition, the filters may intercept interface specific events and 34 ioctls. 35 */ 36 37#ifndef __KPI_INTERFACEFILTER__ 38#define __KPI_INTERFACEFILTER__ 39#include <sys/kernel_types.h> 40#include <net/kpi_interface.h> 41 42struct kev_msg; 43 44__BEGIN_DECLS 45 46/*! 47 @typedef iff_input_func 48 49 @discussion iff_input_func is used to filter incoming packets. The 50 interface is only valid for the duration of the filter call. If 51 you need to keep a reference to the interface, be sure to call 52 ifnet_reference and ifnet_release. The packets passed to the 53 inbound filter are different from those passed to the outbound 54 filter. Packets to the inbound filter have the frame header 55 passed in separately from the rest of the packet. The outbound 56 data filters is passed the whole packet including the frame 57 header. 58 59 The frame header usually preceeds the data in the mbuf. This 60 ensures that the frame header will be a valid pointer as long as 61 the mbuf is not freed. If you need to change the frame header to 62 point somewhere else, the recommended method is to prepend a new 63 frame header to the mbuf chain (mbuf_prepend), set the header to 64 point to that data, then call mbuf_adj to move the mbuf data 65 pointer back to the start of the packet payload. 66 @param cookie The cookie specified when this filter was attached. 67 @param interface The interface the packet was recieved on. 68 @param protocol The protocol of this packet. If you specified a 69 protocol when attaching your filter, the protocol will only ever 70 be the protocol you specified. 71 @param data The inbound packet, after the frame header as determined 72 by the interface. 73 @param frame_ptr A pointer to the pointer to the frame header. The 74 frame header length can be found by inspecting the interface's 75 frame header length (ifnet_hdrlen). 76 @result Return: 77 0 - The caller will continue with normal processing of the 78 packet. 79 EJUSTRETURN - The caller will stop processing the packet, 80 the packet will not be freed. 81 Anything Else - The caller will free the packet and stop 82 processing. 83*/ 84typedef errno_t (*iff_input_func)(void *cookie, ifnet_t interface, 85 protocol_family_t protocol, mbuf_t *data, char **frame_ptr); 86 87/*! 88 @typedef iff_output_func 89 90 @discussion iff_output_func is used to filter fully formed outbound 91 packets. The interface is only valid for the duration of the 92 filter call. If you need to keep a reference to the interface, 93 be sure to call ifnet_reference and ifnet_release. 94 @param cookie The cookie specified when this filter was attached. 95 @param interface The interface the packet is being transmitted on. 96 @param data The fully formed outbound packet in a chain of mbufs. 97 The frame header is already included. The filter function may 98 modify the packet or return a different mbuf chain. 99 @result Return: 100 0 - The caller will continue with normal processing of the 101 packet. 102 EJUSTRETURN - The caller will stop processing the packet, 103 the packet will not be freed. 104 Anything Else - The caller will free the packet and stop 105 processing. 106*/ 107typedef errno_t (*iff_output_func)(void *cookie, ifnet_t interface, 108 protocol_family_t protocol, mbuf_t *data); 109 110/*! 111 @typedef iff_event_func 112 113 @discussion iff_event_func is used to filter interface specific 114 events. The interface is only valid for the duration of the 115 filter call. If you need to keep a reference to the interface, 116 be sure to call ifnet_reference and ifnet_release. 117 @param cookie The cookie specified when this filter was attached. 118 @param interface The interface the packet is being transmitted on. 119 @param event_msg The kernel event, may not be changed. 120*/ 121typedef void (*iff_event_func)(void *cookie, ifnet_t interface, 122 protocol_family_t protocol, const struct kev_msg *event_msg); 123 124/*! 125 @typedef iff_ioctl_func 126 127 @discussion iff_ioctl_func is used to filter ioctls sent to an 128 interface. The interface is only valid for the duration of the 129 filter call. If you need to keep a reference to the interface, 130 be sure to call ifnet_reference and ifnet_release. 131 132 All undefined ioctls are reserved for future use by Apple. If 133 you need to communicate with your kext using an ioctl, please 134 use SIOCSIFKPI and SIOCGIFKPI. 135 @param cookie The cookie specified when this filter was attached. 136 @param interface The interface the packet is being transmitted on. 137 @param ioctl_cmd The ioctl command. 138 @param ioctl_arg A pointer to the ioctl argument. 139 @result Return: 140 0 - This filter function handled the ioctl. 141 EOPNOTSUPP - This filter function does not understand/did not 142 handle this ioctl. 143 EJUSTRETURN - This filter function handled the ioctl, 144 processing should stop. 145 Anything Else - Processing will stop, the error will be 146 returned. 147*/ 148typedef errno_t (*iff_ioctl_func)(void *cookie, ifnet_t interface, 149 protocol_family_t protocol, unsigned long ioctl_cmd, void *ioctl_arg); 150 151/*! 152 @typedef iff_detached_func 153 154 @discussion iff_detached_func is called to notify the filter that it 155 has been detached from an interface. This is the last call to 156 the filter that will be made. A filter may be detached if the 157 interface is detached or the detach filter function is called. 158 In the case that the interface is being detached, your filter's 159 event function will be called with the interface detaching event 160 before the your detached function will be called. 161 @param cookie The cookie specified when this filter was attached. 162 @param interface The interface this filter was detached from. 163*/ 164typedef void (*iff_detached_func)(void *cookie, ifnet_t interface); 165 166/*! 167 @struct iff_filter 168 @discussion This structure is used to define an interface filter for 169 use with the iflt_attach function. 170 @field iff_cookie A kext defined cookie that will be passed to all 171 filter functions. 172 @field iff_name A filter name used for debugging purposes. 173 @field iff_protocol The protocol of the packets this filter is 174 interested in. If you specify zero, packets from all protocols 175 will be passed to the filter. 176 @field iff_input The filter function to handle inbound packets, may 177 be NULL. 178 @field iff_output The filter function to handle outbound packets, 179 may be NULL. 180 @field iff_event The filter function to handle interface events, may 181 be null. 182 @field iff_ioctl The filter function to handle interface ioctls, may 183 be null. 184 @field iff_detached The filter function used to notify the filter that 185 it has been detached. 186*/ 187 188struct iff_filter { 189 void *iff_cookie; 190 const char *iff_name; 191 protocol_family_t iff_protocol; 192 iff_input_func iff_input; 193 iff_output_func iff_output; 194 iff_event_func iff_event; 195 iff_ioctl_func iff_ioctl; 196 iff_detached_func iff_detached; 197}; 198 199/*! 200 @function iflt_attach 201 @discussion Attaches an interface filter to an interface. 202 @param interface The interface the filter should be attached to. 203 @param filter A structure defining the filter. 204 @param filter_ref A reference to the filter used to detach. 205 @result 0 on success otherwise the errno error. 206 */ 207extern errno_t iflt_attach(ifnet_t interface, const struct iff_filter *filter, 208 interface_filter_t *filter_ref); 209 210/*! 211 @function iflt_detach 212 @discussion Detaches an interface filter from an interface. 213 @param filter_ref The reference to the filter from iflt_attach. 214 */ 215extern void iflt_detach(interface_filter_t filter_ref); 216 217__END_DECLS 218#endif /* __KPI_INTERFACEFILTER__ */ 219