reassembly_queue.h | Explore in Territory

/*
 *  Copyright (c) 2021 The WebRTC project authors. All Rights Reserved.
 *
 *  Use of this source code is governed by a BSD-style license
 *  that can be found in the LICENSE file in the root of the source
 *  tree. An additional intellectual property rights grant can be found
 *  in the file PATENTS.  All contributing project authors may
 *  be found in the AUTHORS file in the root of the source tree.
 */
#ifndef NET_DCSCTP_RX_REASSEMBLY_QUEUE_H_
#define NET_DCSCTP_RX_REASSEMBLY_QUEUE_H_

#include <stddef.h>

#include <cstdint>
#include <memory>
#include <set>
#include <string>
#include <utility>
#include <vector>

#include "absl/functional/any_invocable.h"
#include "absl/strings/string_view.h"
#include "api/array_view.h"
#include "net/dcsctp/common/internal_types.h"
#include "net/dcsctp/common/sequence_numbers.h"
#include "net/dcsctp/packet/chunk/forward_tsn_common.h"
#include "net/dcsctp/packet/data.h"
#include "net/dcsctp/packet/parameter/outgoing_ssn_reset_request_parameter.h"
#include "net/dcsctp/packet/parameter/reconfiguration_response_parameter.h"
#include "net/dcsctp/public/dcsctp_message.h"
#include "net/dcsctp/rx/reassembly_streams.h"
#include "rtc_base/containers/flat_set.h"

namespace dcsctp {

// Contains the received DATA chunks that haven't yet been reassembled, and
// reassembles chunks when possible.
//
// The actual assembly is handled by an implementation of the
// `ReassemblyStreams` interface.
//
// Except for reassembling fragmented messages, this class will also handle two
// less common operations; To handle the receiver-side of partial reliability
// (limited number of retransmissions or limited message lifetime) as well as
// stream resetting, which is used when a sender wishes to close a data channel.
//
// Partial reliability is handled when a FORWARD-TSN or I-FORWARD-TSN chunk is
// received, and it will simply delete any chunks matching the parameters in
// that chunk. This is mainly implemented in ReassemblyStreams.
//
// Resetting streams is handled when a RECONFIG chunks is received, with an
// "Outgoing SSN Reset Request" parameter. That parameter will contain a list of
// streams to reset, and a `sender_last_assigned_tsn`. If this TSN is not yet
// seen, the stream cannot be directly reset, and this class will respond that
// the reset is "deferred". But if this TSN provided is known, the stream can be
// immediately be reset.
//
// The ReassemblyQueue has a maximum size, as it would otherwise be an DoS
// attack vector where a peer could consume all memory of the other peer by
// sending a lot of ordered chunks, but carefully withholding an early one. It
// also has a watermark limit, which the caller can query is the number of bytes
// is above that limit. This is used by the caller to be selective in what to
// add to the reassembly queue, so that it's not exhausted. The caller is
// expected to call `is_full` prior to adding data to the queue and to act
// accordingly if the queue is full.
class ReassemblyQueue { … };
}  // namespace dcsctp

#endif  // NET_DCSCTP_RX_REASSEMBLY_QUEUE_H_
chromium/third_party/webrtc/net/dcsctp/rx/reassembly_queue.h
