tor-android/external/badvpn_dns/client/FragmentProtoAssembler.h

135 lines
4.8 KiB
C

/**
* @file FragmentProtoAssembler.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
*
* Object which decodes packets according to FragmentProto.
*/
#ifndef BADVPN_CLIENT_FRAGMENTPROTOASSEMBLER_H
#define BADVPN_CLIENT_FRAGMENTPROTOASSEMBLER_H
#include <stdint.h>
#include <protocol/fragmentproto.h>
#include <misc/debug.h>
#include <misc/compare.h>
#include <base/DebugObject.h>
#include <base/BLog.h>
#include <structure/LinkedList1.h>
#include <structure/SAvl.h>
#include <flow/PacketPassInterface.h>
#define FPA_MAX_TIME UINT32_MAX
struct FragmentProtoAssembler_frame;
#include "FragmentProtoAssembler_tree.h"
#include <structure/SAvl_decl.h>
struct FragmentProtoAssembler_chunk {
int start;
int len;
};
struct FragmentProtoAssembler_frame {
LinkedList1Node list_node; // node in free or used list
struct FragmentProtoAssembler_chunk *chunks; // array of chunks, up to num_chunks
uint8_t *buffer; // buffer with frame data, size output_mtu
// everything below only defined when frame entry is used
fragmentproto_frameid id; // frame identifier
uint32_t time; // packet time when the last chunk was received
FPAFramesTreeNode tree_node; // node fields in tree for searching frames by id
int num_chunks; // number of valid chunks
int sum; // sum of all chunks' lengths
int length; // length of the frame, or -1 if not yet known
int length_so_far; // if length=-1, current data set's upper bound
};
/**
* Object which decodes packets according to FragmentProto.
*
* Input is with {@link PacketPassInterface}.
* Output is with {@link PacketPassInterface}.
*/
typedef struct {
void *user;
BLog_logfunc logfunc;
PacketPassInterface input;
PacketPassInterface *output;
int output_mtu;
int num_chunks;
uint32_t time;
int time_tolerance;
struct FragmentProtoAssembler_frame *frames_entries;
struct FragmentProtoAssembler_chunk *frames_chunks;
uint8_t *frames_buffer;
LinkedList1 frames_free;
LinkedList1 frames_used;
FPAFramesTree frames_used_tree;
int in_len;
uint8_t *in;
int in_pos;
DebugObject d_obj;
} FragmentProtoAssembler;
/**
* Initializes the object.
* {@link BLog_Init} must have been done.
*
* @param o the object
* @param input_mtu maximum input packet size. Must be >=0.
* @param output output interface
* @param num_frames number of frames we can hold. Must be >0 and < FPA_MAX_TIME.
* To make the assembler tolerate out-of-order input of degree D, set to D+2.
* Here, D is the minimum size of a hypothetical buffer needed to order the input.
* @param num_chunks maximum number of chunks a frame can come in. Must be >0.
* @param pg pending group
* @param user argument to handlers
* @param logfunc function which prepends the log prefix using {@link BLog_Append}
* @return 1 on success, 0 on failure
*/
int FragmentProtoAssembler_Init (FragmentProtoAssembler *o, int input_mtu, PacketPassInterface *output, int num_frames, int num_chunks, BPendingGroup *pg, void *user, BLog_logfunc logfunc) WARN_UNUSED;
/**
* Frees the object.
*
* @param o the object
*/
void FragmentProtoAssembler_Free (FragmentProtoAssembler *o);
/**
* Returns the input interface.
*
* @param o the object
* @return input interface
*/
PacketPassInterface * FragmentProtoAssembler_GetInput (FragmentProtoAssembler *o);
#endif