/* * Copyright (c) 2008-2012 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_ipfilter.h This header defines an API to attach IP filters. IP filters may be attached to intercept either IPv4 or IPv6 packets. The filters can intercept all IP packets in to and out of the host regardless of interface. */ #ifndef __KPI_IPFILTER__ #define __KPI_IPFILTER__ #include /* * ipf_pktopts * * Options for outgoing packets. The options need to be preserved when * re-injecting a packet. */ struct ipf_pktopts { u_int32_t ippo_flags; ifnet_t ippo_mcast_ifnet; int ippo_mcast_loop; u_int8_t ippo_mcast_ttl; }; #define IPPOF_MCAST_OPTS 0x1 #ifdef PRIVATE #define IPPOF_BOUND_IF 0x2 #define IPPOF_NO_IFT_CELLULAR 0x4 #define IPPOF_SELECT_SRCIF 0x8 #define IPPOF_BOUND_SRCADDR 0x10 #define IPPOF_SHIFT_IFSCOPE 16 #endif /* PRIVATE */ typedef struct ipf_pktopts *ipf_pktopts_t; __BEGIN_DECLS /*! @typedef ipf_input_func @discussion ipf_input_func is used to filter incoming ip packets. The IP filter is called for packets from all interfaces. The filter is called between when the general IP processing is handled and when the packet is passed up to the next layer protocol such as udp or tcp. In the case of encapsulation, such as UDP in ESP (IPSec), your filter will be called once for ESP and then again for UDP. This will give your filter an opportunity to process the ESP header as well as the decrypted packet. Offset and protocol are used to determine where in the packet processing is currently occuring. If you're only interested in TCP or UDP packets, just return 0 if protocol doesn't match TCP or UDP. @param cookie The cookie specified when your filter was attached. @param data The reassembled ip packet, data will start at the ip header. @param offset An offset to the next header (udp/tcp/icmp/esp/etc...). @param protocol The protocol type (udp/tcp/icmp/etc...) of the IP packet @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 (*ipf_input_func)(void *cookie, mbuf_t *data, int offset, u_int8_t protocol); /*! @typedef ipf_output_func @discussion ipf_output_func is used to filter outbound ip packets. The IP filter is called for packets to all interfaces. The filter is called before fragmentation and IPSec processing. If you need to change the destination IP address, call ipf_inject_output and return EJUSTRETURN. @param cookie The cookie specified when your filter was attached. @param data The ip packet, will contain an IP header followed by the rest of the IP packet. @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 (*ipf_output_func)(void *cookie, mbuf_t *data, ipf_pktopts_t options); /*! @typedef ipf_detach_func @discussion ipf_detach_func is called to notify your filter that it has been detached. @param cookie The cookie specified when your filter was attached. */ typedef void (*ipf_detach_func)(void *cookie); /*! @typedef ipf_filter @discussion This structure is used to define an IP filter for use with the ipf_addv4 or ipf_addv6 function. @field cookie A kext defined cookie that will be passed to all filter functions. @field name A filter name used for debugging purposes. @field ipf_input The filter function to handle inbound packets. @field ipf_output The filter function to handle outbound packets. @field ipf_detach The filter function to notify of a detach. */ struct ipf_filter { void *cookie; const char *name; ipf_input_func ipf_input; ipf_output_func ipf_output; ipf_detach_func ipf_detach; }; struct opaque_ipfilter; typedef struct opaque_ipfilter *ipfilter_t; /*! @function ipf_addv4 @discussion Attaches an IPv4 ip filter. @param filter A structure defining the filter. @param filter_ref A reference to the filter used to detach it. @result 0 on success otherwise the errno error. */ extern errno_t ipf_addv4(const struct ipf_filter *filter, ipfilter_t *filter_ref); /*! @function ipf_addv6 @discussion Attaches an IPv6 ip filter. @param filter A structure defining the filter. @param filter_ref A reference to the filter used to detach it. @result 0 on success otherwise the errno error. */ extern errno_t ipf_addv6(const struct ipf_filter *filter, ipfilter_t *filter_ref); /*! @function ipf_remove @discussion Detaches an IPv4 or IPv6 filter. @param filter_ref The reference to the filter returned from ipf_addv4 or ipf_addv6. @result 0 on success otherwise the errno error. */ extern errno_t ipf_remove(ipfilter_t filter_ref); /*! @function ipf_inject_input @discussion Inject an IP packet as though it had just been reassembled in ip_input. When re-injecting a packet intercepted by the filter's ipf_input function, an IP filter can pass its reference to avoid processing the packet twice. This also prevents ip filters installed before this filter from getting a chance to process the packet. If the filter modified the packet, it should not specify the filter ref to give other filters a chance to process the new packet. Caller is responsible for freeing mbuf chain in the event that ipf_inject_input returns an error. @param data The complete IPv4 or IPv6 packet, receive interface must be set. @param filter_ref The reference to the filter injecting the data @result 0 on success otherwise the errno error. */ extern errno_t ipf_inject_input(mbuf_t data, ipfilter_t filter_ref); /*! @function ipf_inject_output @discussion Inject an IP packet as though it had just been sent to ip_output. When re-injecting a packet intercepted by the filter's ipf_output function, an IP filter can pass its reference to avoid processing the packet twice. This also prevents ip filters installed before this filter from getting a chance to process the packet. If the filter modified the packet, it should not specify the filter ref to give other filters a chance to process the new packet. @param data The complete IPv4 or IPv6 packet. @param filter_ref The reference to the filter injecting the data @param options Output options for the packet @result 0 on success otherwise the errno error. ipf_inject_output will always free the mbuf. */ extern errno_t ipf_inject_output(mbuf_t data, ipfilter_t filter_ref, ipf_pktopts_t options); __END_DECLS #endif /* __KPI_IPFILTER__ */