badvpn/flow/PacketPassNotifier.h
2012-01-27 13:24:37 +00:00

100 lines
3.5 KiB
C

/**
* @file PacketPassNotifier.h
* @author Ambroz Bizjak <ambrop7@gmail.com>
*
* @section LICENSE
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. Neither the name of the author nor the
* names of its contributors may be used to endorse or promote products
* derived from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
* WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
* DISCLAIMED. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY
* DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
* (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
* LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
* ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
* SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*
* @section DESCRIPTION
*
* A {@link PacketPassInterface} layer which calles a handler function before
* passing a packet from input to output.
*/
#ifndef BADVPN_FLOW_PACKETPASSNOTIFIER_H
#define BADVPN_FLOW_PACKETPASSNOTIFIER_H
#include <stdint.h>
#include <base/DebugObject.h>
#include <flow/PacketPassInterface.h>
/**
* Handler function called when input calls Send, but before the call is passed on to output.
*
* @param user value specified in {@link PacketPassNotifier_SetHandler}
* @param data packet provided by input
* @param data_len size of the packet
*/
typedef void (*PacketPassNotifier_handler_notify) (void *user, uint8_t *data, int data_len);
/**
* A {@link PacketPassInterface} layer which calles a handler function before
* passing a packet from input to output.
*/
typedef struct {
PacketPassInterface input;
PacketPassInterface *output;
PacketPassNotifier_handler_notify handler;
void *handler_user;
DebugObject d_obj;
} PacketPassNotifier;
/**
* Initializes the object.
*
* @param o the object
* @param output output interface
* @param pg pending group
*/
void PacketPassNotifier_Init (PacketPassNotifier *o, PacketPassInterface *output, BPendingGroup *pg);
/**
* Frees the object.
*
* @param o the object
*/
void PacketPassNotifier_Free (PacketPassNotifier *o);
/**
* Returns the input interface.
* The MTU of the interface will be the same as of the output interface.
* The interface supports cancel functionality if the output interface supports it.
*
* @param o the object
* @return input interface
*/
PacketPassInterface * PacketPassNotifier_GetInput (PacketPassNotifier *o);
/**
* Configures a handler function to call before passing input packets to output.
*
* @param o the object
* @param handler handler function, or NULL to disable.
* @param user value to pass to handler function. Ignored if handler is NULL.
*/
void PacketPassNotifier_SetHandler (PacketPassNotifier *o, PacketPassNotifier_handler_notify handler, void *user);
#endif