LeOS-Genesis/external/badvpn/flow/RouteBuffer.h

140 lines
4.6 KiB
C

/**
* @file RouteBuffer.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
*
* Packet buffer for zero-copy packet routing.
*/
#ifndef BADVPN_FLOW_ROUTEBUFFER_H
#define BADVPN_FLOW_ROUTEBUFFER_H
#include <misc/debug.h>
#include <structure/LinkedList1.h>
#include <base/DebugObject.h>
#include <flow/PacketPassInterface.h>
struct RouteBuffer_packet {
LinkedList1Node node;
int len;
};
/**
* Packet buffer for zero-copy packet routing.
*
* Packets are buffered using {@link RouteBufferSource} objects.
*/
typedef struct {
int mtu;
PacketPassInterface *output;
LinkedList1 packets_free;
LinkedList1 packets_used;
DebugObject d_obj;
} RouteBuffer;
/**
* Object through which packets are buffered into {@link RouteBuffer} objects.
*
* A packet is routed by calling {@link RouteBufferSource_Pointer}, writing it to
* the returned address, then calling {@link RouteBufferSource_Route}.
*/
typedef struct {
int mtu;
struct RouteBuffer_packet *current_packet;
DebugObject d_obj;
} RouteBufferSource;
/**
* Initializes the object.
*
* @param o the object
* @param mtu maximum packet size. Must be >=0. It will only be possible to route packets to this buffer
* from {@link RouteBufferSource}.s with the same MTU.
* @param output output interface. Its MTU must be >=mtu.
* @param buf_size size of the buffer in number of packet. Must be >0.
* @return 1 on success, 0 on failure
*/
int RouteBuffer_Init (RouteBuffer *o, int mtu, PacketPassInterface *output, int buf_size) WARN_UNUSED;
/**
* Frees the object.
*/
void RouteBuffer_Free (RouteBuffer *o);
/**
* Retuns the buffer's MTU (mtu argument to {@link RouteBuffer_Init}).
*
* @return MTU
*/
int RouteBuffer_GetMTU (RouteBuffer *o);
/**
* Initializes the object.
*
* @param o the object
* @param mtu maximum packet size. Must be >=0. The object will only be able to route packets
* to {@link RouteBuffer}'s with the same MTU.
* @return 1 on success, 0 on failure
*/
int RouteBufferSource_Init (RouteBufferSource *o, int mtu) WARN_UNUSED;
/**
* Frees the object.
*
* @param o the object
*/
void RouteBufferSource_Free (RouteBufferSource *o);
/**
* Returns a pointer to the current packet.
* The pointed to memory area will have space for MTU bytes.
* The pointer is only valid until {@link RouteBufferSource_Route} succeeds.
*
* @param o the object
* @return pointer to the current packet
*/
uint8_t * RouteBufferSource_Pointer (RouteBufferSource *o);
/**
* Routes the current packet to a given buffer.
* On success, this invalidates the pointer previously returned from
* {@link RouteBufferSource_Pointer}.
*
* @param o the object
* @param len length of the packet. Must be >=0 and <=MTU.
* @param b buffer to route to. Its MTU must equal this object's MTU.
* @param copy_offset Offset from the beginning for copying. Must be >=0 and
* <=mtu.
* @param copy_len Number of bytes to copy from the old current packet to the new one.
* Must be >=0 and <= mtu - copy_offset.
* @return 1 on success, 0 on failure
*/
int RouteBufferSource_Route (RouteBufferSource *o, int len, RouteBuffer *b, int copy_offset, int copy_len);
#endif