--- /dev/null
+/*
+ * Copyright (c) 2003 Apple Computer, Inc. All rights reserved.
+ *
+ * @APPLE_LICENSE_HEADER_START@
+ *
+ * The contents of this file constitute Original Code as defined in and
+ * are subject to the Apple Public Source License Version 1.1 (the
+ * "License"). You may not use this file except in compliance with the
+ * License. Please obtain a copy of the License at
+ * http://www.apple.com/publicsource and read it before using this file.
+ *
+ * This 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 OR NON-INFRINGEMENT. Please see the
+ * License for the specific language governing rights and limitations
+ * under the License.
+ *
+ * @APPLE_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>
+
+struct kev_msg;
+
+/*!
+ @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.
+ @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 - 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_ioctl_func)(void* cookie, ifnet_t interface, protocol_family_t protocol,
+ u_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.
+ */
+errno_t iflt_attach(ifnet_t interface, const struct iff_filter* filter,
+ interface_filter_t *filter_ref);
+
+/*!
+ @function iflt_detach
+ @discussion Detaches an interface filter from an interface.
+ @param filter_ref The reference to the filter from iflt_attach.
+ */
+void iflt_detach(interface_filter_t filter_ref);
+
+#endif
projects / apple / xnu.git / blobdiff