mirror of https://github.com/status-im/nim-eth.git
uTP clarification on SYN-ACK seqnr and some cleanup (#596)
- Clarify why on SYN-ACK seqNr gets -1 - Cleanup comments - Style fixes - Reuse WriteResult
This commit is contained in:
Kim De Mey
GitHub
parent
4754543605
commit
ea3c164a00
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@ -1,4 +1,4 @@
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# Copyright (c) 2021-2022 Status Research & Development GmbH
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# Copyright (c) 2021-2023 Status Research & Development GmbH
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# Licensed and distributed under either of
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# * MIT license (license terms in the root directory or at https://opensource.org/licenses/MIT).
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# * Apache v2 license (license terms in the root directory or at https://www.apache.org/licenses/LICENSE-2.0).
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@ -97,9 +97,10 @@ proc registerUtpSocket[A](p: UtpRouter, s: UtpSocket[A]) =
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## Register socket, overwriting already existing one
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p.sockets[s.socketKey] = s
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utp_established_connections.set(int64(len(p.sockets)))
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debug "Registered new utp socket", dst = s.socketKey, lenSockets = len(p.sockets)
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# Install deregister handler, so when socket gets closed, in will be promptly
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# removed from open sockets table
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debug "Registered new uTP socket",
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dst = s.socketKey, totalSockets = len(p.sockets)
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# Install deregister handler so that when the socket gets closed, it gets
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# removed from open sockets table.
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s.registerCloseCallback(proc () = p.deRegisterUtpSocket(s))
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proc registerIfAbsent[A](p: UtpRouter, s: UtpSocket[A]): bool =
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@ -144,7 +145,9 @@ proc new*[A](
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rng = newRng()): UtpRouter[A] =
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doAssert(not(isNil(acceptConnectionCb)))
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GC_ref(udata)
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UtpRouter[A].new(acceptConnectionCb, allowConnectionCb, cast[pointer](udata), socketConfig, rng)
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UtpRouter[A].new(
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acceptConnectionCb, allowConnectionCb,
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cast[pointer](udata), socketConfig, rng)
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proc new*[A](
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T: type UtpRouter[A],
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@ -168,7 +171,8 @@ proc getSocketOnReset[A](
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# id is our send id, and we did initiate the connection, our recv id is id - 1
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let sendInitKey = UtpSocketKey[A].init(sender, id - 1)
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# id is our send id, and we did not initiate the connection, so our recv id is id + 1
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# id is our send id, and we did not initiate the connection,
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# our recv id is id + 1
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let sendNoInitKey = UtpSocketKey[A].init(sender, id + 1)
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r.getUtpSocket(recvKey)
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@ -178,7 +182,7 @@ proc getSocketOnReset[A](
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proc shouldAllowConnection[A](
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r: UtpRouter[A], remoteAddress: A, connectionId: uint16): bool =
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if r.allowConnection == nil:
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# if the callback is not configured it means all incoming connections are allowed
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# if the callback is not configured all incoming connections are allowed
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true
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else:
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r.allowConnection(r, remoteAddress, connectionId)
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@ -194,16 +198,17 @@ proc processPacket[A](r: UtpRouter[A], p: Packet, sender: A) {.async.}=
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if maybeSocket.isSome():
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debug "Received RST packet on known connection, closing socket"
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let socket = maybeSocket.unsafeGet()
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# reference implementation actually changes the socket state to reset state unless
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# user explicitly closed socket before. The only difference between reset and destroy
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# state is that socket in destroy state is ultimately deleted from active connection
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# list but socket in reset state lingers there until user of library closes it
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# explicitly.
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# The reference implementation actually changes the socket state to reset
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# state unless the user explicitly closed the socket before. The only
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# difference between the reset and the destroy state is that a socket in
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# the destroy state is ultimately deleted from active connection list but
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# a socket in reset state lingers there until the user of library closes
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# it explicitly.
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socket.destroy()
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else:
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debug "Received RST packet for unknown connection, ignoring"
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of ST_SYN:
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# Syn packet are special, and we need to add 1 to header connectionId
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# SYN packets are special and need an addition of 1 to header connectionId
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let socketKey = UtpSocketKey[A].init(sender, p.header.connectionId + 1)
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let maybeSocket = r.getUtpSocket(socketKey)
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if (maybeSocket.isSome()):
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@ -220,7 +225,7 @@ proc processPacket[A](r: UtpRouter[A], p: Packet, sender: A) {.async.}=
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if (r.shouldAllowConnection(sender, p.header.connectionId)):
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debug "Received SYN for new connection. Initiating incoming connection",
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synSeqNr = p.header.seqNr
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# Initial ackNr is set to incoming packer seqNr
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# Initial ackNr is set to incoming packet seqNr
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let incomingSocket = newIncomingSocket[A](
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sender, r.sendCb, r.socketConfig,
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p.header.connectionId, p.header.seqNr, r.rng[])
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@ -242,7 +247,7 @@ proc processPacket[A](r: UtpRouter[A], p: Packet, sender: A) {.async.}=
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let socket = maybeSocket.unsafeGet()
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await socket.processPacket(p)
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else:
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# TODO add keeping track of recently send reset packets and do not send
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# TODO: add keeping track of recently send reset packets and do not send
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# reset to peers which we recently send reset to.
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debug "Received FIN/DATA/ACK on not known socket sending reset"
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let rstPacket = resetPacket(
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@ -334,8 +339,8 @@ proc connectTo*[A](
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let connFut = socket.connect()
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return connFut
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# Connect to provided address with provided connection id, if socket with this id
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# and address already exists return error
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# Connect to provided address with provided connection id. If the socket with
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# this id and address already exists, return error
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proc connectTo*[A](
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r: UtpRouter[A], address: A, connectionId: uint16):
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Future[ConnectionResult[A]] =
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@ -1,4 +1,4 @@
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# Copyright (c) 2021-2022 Status Research & Development GmbH
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# Copyright (c) 2021-2023 Status Research & Development GmbH
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# Licensed and distributed under either of
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# * MIT license (license terms in the root directory or at https://opensource.org/licenses/MIT).
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# * Apache v2 license (license terms in the root directory or at https://www.apache.org/licenses/LICENSE-2.0).
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@ -48,16 +48,18 @@ type
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PacketAcked, PacketAlreadyAcked, PacketNotSentYet
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# Socket callback to send data to remote peer
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SendCallback*[A] = proc (to: A, data: seq[byte]): Future[void] {.gcsafe, raises: [Defect]}
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SendCallback*[A] =
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proc (to: A, data: seq[byte]): Future[void] {.gcsafe, raises: [Defect]}
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SocketConfig* = object
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# This is configurable (in contrast to reference impl), as with standard 2 syn resends
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# default timeout set to 3seconds and doubling of timeout with each re-send, it
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# means that initial connection would timeout after 21s, which seems rather long
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# This is configurable (in contrast to reference impl), as with standard 2
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# SYN resends, the default timeout of 3 seconds and the doubling of the
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# timeout with each resend, it means that the initial connection would
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# timeout only after 21s, which seems rather long.
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initialSynTimeout*: Duration
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# Number of resend re-tries of each data packet, before declaring connection
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# failed
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# Number of resend retries of each data packet, before declaring the
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# connection as failed.
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dataResendsBeforeFailure*: uint16
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# Maximal size of receive buffer in bytes
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@ -73,23 +75,24 @@ type
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# state and will be able to transfer data.
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incomingSocketReceiveTimeout*: Option[Duration]
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# Timeout after which the send window will be reset to its minimal value after it dropped
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# to zero. i.e when we received a packet from remote peer with `wndSize` set to 0.
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# Timeout after which the send window will be reset to its minimal value
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# after it dropped to zero.
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# i.e when a packet is received from a peer with `wndSize` set to 0.
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remoteWindowResetTimeout*: Duration
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# Size of reorder buffer calculated as fraction of optRcvBuffer
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maxSizeOfReorderBuffer: uint32
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# Maximal number of payload bytes per data packet. Total packet size will be equal to
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# payloadSize + 20 (size of header of data packet)
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# TODO for now we enable only static configuration of packet sizes. In the future
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# it would be nice to add option which enables automatic packet size discovery
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# based on traffic
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# Maximal number of payload bytes per data packet. Total packet size will be
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# equal to payloadSize + 20 (size of header of data packet).
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# TODO: for now we enable only static configuration of packet sizes. In the
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# future it would be nice to add option which enables automatic packet size
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# discovery based on traffic.
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payloadSize*: uint32
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# Maximal number of open uTP connections. When hit, no more incoming connections
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# will be allowed, but it will still be possible to open new outgoing uTP
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# connections
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# Maximal number of open uTP connections. When hit, no more incoming
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# connections will be allowed, but it will still be possible to open new
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# outgoing uTP connections.
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maxNumberOfOpenConnections*: int
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WriteErrorType* = enum
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@ -147,25 +150,25 @@ type
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direction: ConnectionDirection
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socketConfig: SocketConfig
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# Connection id for packets we receive
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# Connection id for received packets
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connectionIdRcv*: uint16
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# Connection id for packets we send
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# Connection id for send packets
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connectionIdSnd*: uint16
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# Sequence number for the next packet to be sent.
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seqNr: uint16
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# All seq number up to this have been correctly acked by us
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# All sequence numbers up to this have been correctly acked by us.
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ackNr: uint16
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# Should be completed after successful connection to remote host or after timeout
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# for the first syn packet
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# Should be completed after successful connection to remote host or after
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# timeout for the first SYN packet.
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connectionFuture: Future[void]
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# the number of packets in the send queue. Packets that haven't
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# yet been sent count as well as packets marked as needing resend
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# the oldest un-acked packet in the send queue is seq_nr - cur_window_packets
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# The number of packets in the send queue. Packets that haven't
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# been sent yet and packets marked as needing to be resend count.
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# The oldest un-acked packet in the send queue is seq_nr - cur_window_packets
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curWindowPackets: uint16
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# out going buffer for all send packets
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# outgoing buffer for all send packets
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outBuffer: GrowableCircularBuffer[OutgoingPacket]
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# current number of bytes in send buffer
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@ -309,29 +312,28 @@ type
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ConnectionResult*[A] = Result[UtpSocket[A], OutgoingConnectionError]
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const
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# Default maximum size of the data packet payload. With such configuration
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# Default maximum size of the data packet payload. With this configuration
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# data packets will have 508 bytes (488 + 20 header).
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# 508 bytes of udp payload can translate into 576 bytes udp packet i.e
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# 508bytes payload + 60bytes (max ip header) + 8bytes (udp header) = 576bytes.
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# 576bytes is defined as minimum reassembly buffer size i.e
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# the minimum datagram size that we are guaranteed any implementation must support.
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# from RFC791: All hosts must be prepared
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# to accept datagrams of up to 576 octets (whether they arrive whole
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# or in fragments).
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# 508 bytes of UDP payload can translate into 576 bytes UDP packet i.e
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# 508 bytes + 60 bytes (max IP header) + 8 bytes (UDP header) = 576 bytes.
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# 576 bytes is defined as minimum reassembly buffer size, i.e the minimum
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# datagram size that any implementation must support.
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# From RFC791: All hosts must be prepared to accept datagrams of up to 576
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# octets (whether they arrive whole or in fragments).
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defaultPayloadSize = 488
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# How often each socket check its different on going timers
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# How often each socket check its different ongoing timers
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checkTimeoutsLoopInterval = milliseconds(500)
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# Default initial timeout for first Syn packet
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# Default initial timeout for first SYN packet
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defaultInitialSynTimeout = milliseconds(3000)
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# Initial timeout to receive first Data data packet after receiving initial Syn
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# packet.
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# Initial timeout to receive first Data data packet after receiving initial
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# SYN packet.
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defaultRcvRetransmitTimeout = milliseconds(10000)
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# Number of times each data packet will be resend before declaring connection
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# dead. 4 is taken from reference implementation
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# dead. 4 is taken from reference implementation.
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defaultDataResendsBeforeFailure = 4'u16
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# default size of rcv buffer in bytes
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@ -350,9 +352,9 @@ const
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# considered suspicious and ignored
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allowedAckWindow*: uint16 = 3
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# Timeout after which the send window will be reset to its minimal value after it dropped
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# lower than our current packet size. i.e when we received a packet
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# from remote peer with `wndSize` set to number <= current packet size
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# Timeout after which the send window will be reset to its minimal value after
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# it dropped lower than our current packet size. i.e when we received a packet
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# from remote peer with `wndSize` set to number <= current packet size.
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defaultResetWindowTimeout = seconds(15)
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reorderBufferMaxSize = 1024
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@ -362,18 +364,19 @@ const
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# minimal time before subsequent window decays
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maxWindowDecay = milliseconds(100)
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# Maximal size of reorder buffer as fraction of optRcvBuffer size following
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# semantics apply bases on rcvBuffer set to 1000 bytes:
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# if there are already 1000 bytes in rcv buffer no more bytes will be accepted to reorder buffer
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# if there are already 500 bytes in reorder buffer, no more bytes will be accepted
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# to it, and only 500 bytes can be accepted to rcv buffer
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# this way there is always a space in rcv buffer to fit new data if the reordering
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# happens
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# Maximal size of reorder buffer as fraction of optRcvBuffer size.
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# Following semantics apply based on a rcvBuffer set to 1000 bytes:
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# - if there are already 1000 bytes in rcvBuffer no more bytes will be
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# accepted to reorder buffer
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# - if there are already 500 bytes in reorder buffer, no more bytes will be
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# accepted to it, and only 500 bytes can be accepted to rcvBuffer
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# This way there is always a space in rcvBuffer to fit new data if the
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# reordering happens.
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maxReorderBufferSize = 0.5
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# Default number of of open utp connections
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# libutp uses 3000
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# libtorrent uses ~16000
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# - libutp uses 3000
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# - libtorrent uses ~16000
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defaultMaxOpenConnections = 8000
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proc init*[A](T: type UtpSocketKey, remoteAddress: A, rcvId: uint16): T =
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@ -405,9 +408,11 @@ proc init*(
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payloadSize: uint32 = defaultPayloadSize,
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maxNumberOfOpenConnections: int = defaultMaxOpenConnections
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): T =
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# make sure there is always some payload in data packets, and that packets are not to large.
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# with 1480 packet boundary, data packets will have 1500 bytes which seems reasonable
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doAssert(payloadSize > 0 and payloadSize <= 1480, "payloadSize should always be positive number <= 1480")
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# Make sure there is always some payload in data packets, and that packets are
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# not to large. With 1480 packet boundary, data packets will have 1500 bytes
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# which seems reasonable.
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doAssert(payloadSize > 0 and payloadSize <= 1480,
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"payloadSize should always be positive number <= 1480")
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# TODO make sure optRcvBuffer is nicely divisible by maxReorderBufferSize
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let reorderBufferSize = uint32(maxReorderBufferSize * float64(optRcvBuffer))
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SocketConfig(
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@ -478,11 +483,14 @@ proc flushPackets(socket: UtpSocket) =
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var i: uint16 = oldestOutgoingPacketSeqNr
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while i != socket.seqNr:
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# sending only packet which were not transmitted yet or need a resend
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let shouldSendPacket = socket.outBuffer.exists(i, (p: OutgoingPacket) => (p.transmissions == 0 or p.needResend == true))
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let shouldSendPacket = socket.outBuffer.exists(
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i, (p: OutgoingPacket) => (p.transmissions == 0 or p.needResend == true))
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if (shouldSendPacket):
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if (socket.freeWindowBytes() > 0):
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# this our first send packet reset rto timeout
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if i == oldestOutgoingPacketSeqNr and socket.curWindowPackets == 1 and socket.outBuffer[i].transmissions == 0:
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if i == oldestOutgoingPacketSeqNr and
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socket.curWindowPackets == 1 and
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socket.outBuffer[i].transmissions == 0:
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socket.resetSendTimeout()
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debug "Flushing packet",
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@ -501,14 +509,16 @@ proc flushPackets(socket: UtpSocket) =
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proc markAllPacketAsLost(s: UtpSocket) =
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var i = 0'u16
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while i < s.curWindowPackets:
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let packetSeqNr = s.seqNr - 1 - i
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if (s.outBuffer.exists(packetSeqNr, (p: OutgoingPacket) => p.transmissions > 0 and p.needResend == false)):
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if (s.outBuffer.exists(
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packetSeqNr,
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(p: OutgoingPacket) => p.transmissions > 0 and p.needResend == false)):
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debug "Marking packet as lost",
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pkSeqNr = packetSeqNr
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s.outBuffer[packetSeqNr].needResend = true
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let packetPayloadLength = s.outBuffer[packetSeqNr].payloadLength
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doAssert(s.currentWindow >= packetPayloadLength, "Window should always be larger than packet length")
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doAssert(s.currentWindow >= packetPayloadLength,
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"Window should always be larger than packet length")
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s.currentWindow = s.currentWindow - packetPayloadLength
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inc i
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@ -655,7 +665,6 @@ proc handleDataWrite(socket: UtpSocket, data: seq[byte]): int =
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let lastOrEnd = min(lastIndex, endIndex)
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let dataSlice = data[i..lastOrEnd]
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let payloadLength = uint32(len(dataSlice))
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if (socket.outBufferBytes + payloadLength <= socket.socketConfig.optSndBuffer):
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let wndSize = socket.getRcvWindowSize()
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let dataPacket =
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@ -667,9 +676,12 @@ proc handleDataWrite(socket: UtpSocket, data: seq[byte]): int =
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dataSlice,
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socket.replayMicro
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)
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let outgoingPacket = OutgoingPacket.init(encodePacket(dataPacket), 0, false, payloadLength)
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let outgoingPacket = OutgoingPacket.init(
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encodePacket(dataPacket), 0, false, payloadLength)
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socket.registerOutgoingPacket(outgoingPacket)
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bytesWritten = bytesWritten + len(dataSlice)
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# TODO: When flushPackets early ended because of send window being full,
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# it keeps trying here again for each dataSlice. Sounds waistfull?
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socket.flushPackets()
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else:
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debug "No more place in write buffer",
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@ -851,6 +863,14 @@ proc calculateAckedbytes(socket: UtpSocket, nrPacketsToAck: uint16, now: Moment)
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proc initializeAckNr(socket: UtpSocket, packetSeqNr: uint16) =
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if (socket.state == SynSent):
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# Different from the uTP spec but in accordance with libutp and libtorrent.
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# When receiving the ACK of a SYN packet, the socket ackNr gets initialized
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# as the packet seqNr - 1. This way, the socket ackNr is set up as one less
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# the next seqNr for an incoming DATA packet. The seqNr in STATE packets
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# should basically be seen as the seqNr for the next DATA or FIN packet.
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# See also:
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# - libutp: https://github.com/bittorrent/libutp/blob/master/utp_internal.cpp#L1874
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# - libtorrent: https://github.com/arvidn/libtorrent/blob/RC_2_0/src/utp_stream.cpp#L2924
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socket.ackNr = packetSeqNr - 1
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proc isAckNrInvalid(socket: UtpSocket, packet: Packet): bool =
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@ -1055,9 +1075,8 @@ proc generateAckPacket*(socket: UtpSocket): Packet =
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)
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|
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proc sendAck(socket: UtpSocket) =
|
||||
## Creates and sends ack, based on current socket state. Acks are different from
|
||||
## other packets as we do not track them in outgoing buffet
|
||||
|
||||
## Creates and sends ack, based on current socket state. Acks are different
|
||||
## from other packets as we do not track them in outgoing buffer.
|
||||
let ackPacket = socket.generateAckPacket()
|
||||
|
||||
debug "Sending STATE packet",
|
||||
|
|
@ -1086,10 +1105,9 @@ proc tryfinalizeConnection(socket: UtpSocket, p: Packet) =
|
|||
if (not socket.connectionFuture.finished()):
|
||||
socket.connectionFuture.complete()
|
||||
|
||||
# TODO at socket level we should handle only FIN/DATA/ACK packets. Refactor to make
|
||||
# it enforceable by type system
|
||||
# TODO: at socket level we should handle only FIN/DATA/ACK packets. Refactor to
|
||||
# make it enforceable by type system
|
||||
proc processPacketInternal(socket: UtpSocket, p: Packet) =
|
||||
|
||||
debug "Process packet",
|
||||
socketKey = socket.socketKey,
|
||||
socketAckNr = socket.ackNr,
|
||||
|
|
@ -1571,8 +1589,8 @@ proc eventLoop(socket: UtpSocket) {.async.} =
|
|||
# stop processing further reads
|
||||
break
|
||||
else:
|
||||
# read was cancelled or socket is already finished move on to next read
|
||||
# request
|
||||
# read was cancelled or socket is already finished move on to next
|
||||
# read request
|
||||
discard socket.pendingReads.popFirst()
|
||||
|
||||
# we processed packet, so there could more place in the send buffer
|
||||
|
|
@ -1592,12 +1610,13 @@ proc eventLoop(socket: UtpSocket) {.async.} =
|
|||
if (bytesWritten == len(pendingWrite.data)):
|
||||
# all bytes were written we can finish external future
|
||||
pendingWrite.writer.complete(
|
||||
Result[int, WriteError].ok(bytesWritten)
|
||||
WriteResult.ok(bytesWritten)
|
||||
)
|
||||
else:
|
||||
let bytesLeft =
|
||||
pendingWrite.data[bytesWritten..pendingWrite.data.high]
|
||||
# bytes partially written to buffer, schedule rest of data for later
|
||||
# bytes partially written to buffer, schedule rest of data for
|
||||
# later
|
||||
socket.pendingWrites.addFirst(
|
||||
WriteRequest(
|
||||
kind: Data,
|
||||
|
|
@ -1619,7 +1638,8 @@ proc eventLoop(socket: UtpSocket) {.async.} =
|
|||
# check if the writer was not cancelled in mean time
|
||||
if (not socketEvent.writer.finished()):
|
||||
if (socket.pendingWrites.len() > 0):
|
||||
# there are still some unfinished writes, waiting to be finished schdule this batch for later
|
||||
# there are still some unfinished writes, waiting to be finished
|
||||
# schedule this batch for later
|
||||
socket.pendingWrites.addLast(
|
||||
WriteRequest(
|
||||
kind: Data,
|
||||
|
|
@ -1632,7 +1652,7 @@ proc eventLoop(socket: UtpSocket) {.async.} =
|
|||
if (bytesWritten == len(socketEvent.data)):
|
||||
# all bytes were written we can finish external future
|
||||
socketEvent.writer.complete(
|
||||
Result[int, WriteError].ok(bytesWritten)
|
||||
WriteResult.ok(bytesWritten)
|
||||
)
|
||||
else:
|
||||
let bytesLeft =
|
||||
|
|
@ -1649,8 +1669,8 @@ proc eventLoop(socket: UtpSocket) {.async.} =
|
|||
# check if the writer was not cancelled in mean time
|
||||
if (not socketEvent.readReq.reader.finished()):
|
||||
if (socket.pendingReads.len() > 0):
|
||||
# there is already pending unfinished read request, schedule this one for
|
||||
# later
|
||||
# there is already pending unfinished read request, schedule this
|
||||
# one for later
|
||||
socket.pendingReads.addLast(socketEvent.readReq)
|
||||
else:
|
||||
var readReq = socketEvent.readReq
|
||||
|
|
@ -1665,19 +1685,19 @@ proc eventLoop(socket: UtpSocket) {.async.} =
|
|||
except CancelledError as exc:
|
||||
for w in socket.pendingWrites.items():
|
||||
if w.kind == Data and (not w.writer.finished()):
|
||||
let res = Result[int, WriteError].err(
|
||||
let res = WriteResult.err(
|
||||
WriteError(kind: SocketNotWriteable, currentState: socket.state)
|
||||
)
|
||||
w.writer.complete(res)
|
||||
for r in socket.pendingReads.items():
|
||||
# complete every reader with already read bytes
|
||||
# TODO: it maybe better to refine read api to return Future[Result[seq[byte], E]]
|
||||
# and return errors for not finished reads
|
||||
# TODO: it may be better to refine read API to return
|
||||
# Future[Result[seq[byte], E]] and return errors for not finished reads
|
||||
if (not r.reader.finished()):
|
||||
r.reader.complete(r.bytesAvailable)
|
||||
socket.pendingWrites.clear()
|
||||
socket.pendingReads.clear()
|
||||
# main eventLoop has been cancelled, try to cancel check timeouts loop
|
||||
# main eventLoop has been cancelled, try to cancel `checkTimeoutsLoop`
|
||||
socket.checkTimeoutsLoop.cancel()
|
||||
trace "main socket event loop cancelled"
|
||||
raise exc
|
||||
|
|
@ -1686,16 +1706,16 @@ proc startEventLoop(s: UtpSocket) =
|
|||
s.eventLoop = eventLoop(s)
|
||||
|
||||
proc atEof*(socket: UtpSocket): bool =
|
||||
# socket is considered at eof when remote side sent us fin packet
|
||||
# and we have processed all packets up to fin
|
||||
# The socket is considered at eof when the remote side sent us a FIN packet
|
||||
# and all packets up to the FIN have been processed.
|
||||
socket.offset == 0 and socket.reachedFin
|
||||
|
||||
proc readingClosed(socket: UtpSocket): bool =
|
||||
socket.atEof() or socket.state == Destroy
|
||||
|
||||
proc close*(socket: UtpSocket) =
|
||||
## Gracefully closes connection (send FIN) if socket is in connected state
|
||||
## does not wait for socket to close
|
||||
## Gracefully close the connection (send FIN) if the socket is in the
|
||||
## connected state. Does not wait for the socket to close.
|
||||
if socket.state != Destroy:
|
||||
case socket.state
|
||||
of Connected:
|
||||
|
|
@ -1703,26 +1723,26 @@ proc close*(socket: UtpSocket) =
|
|||
if (not socket.sendFinRequested):
|
||||
try:
|
||||
debug "Sending FIN", dst = socket.socketKey
|
||||
# with this approach, all pending writes will be executed before sending fin packet
|
||||
# we could also and method which places close request as first one to process
|
||||
# but it would complicate the write loop
|
||||
# With this approach, all pending writes will be executed before
|
||||
# sending the FIN packet.
|
||||
socket.eventQueue.putNoWait(SocketEvent(kind: CloseReq))
|
||||
except AsyncQueueFullError as e:
|
||||
# should not happen as our write queue is unbounded
|
||||
# Should not happen as our write queue is unbounded.
|
||||
raiseAssert e.msg
|
||||
|
||||
socket.sendFinRequested = true
|
||||
else:
|
||||
# In any other case like connection is not established so sending fin make
|
||||
# no sense, we can just out right close it
|
||||
# When connection is not established, sending FIN makes no sense, just
|
||||
# destroy the socket.
|
||||
socket.destroy()
|
||||
|
||||
proc closeWait*(socket: UtpSocket) {.async.} =
|
||||
## Gracefully closes connection (send FIN) if socket is in connected state
|
||||
## and waits for socket to be closed.
|
||||
## Warning: if FIN packet for some reason will be lost, then socket will be closed
|
||||
## due to retransmission failure which may take some time.
|
||||
## default is 4 retransmissions with doubling of rto between each retransmission
|
||||
## Gracefully close the connection (send FIN) if the socket is in the
|
||||
## connected state and wait for the socket to be closed.
|
||||
## Warning: if the FIN packet is lost, then the socket might get closed due to
|
||||
## retransmission failures, which will take some time.
|
||||
## The default is 4 retransmissions with doubling of rto between each
|
||||
## retransmission.
|
||||
socket.close()
|
||||
await socket.closeEvent.wait()
|
||||
|
||||
|
|
@ -1732,26 +1752,27 @@ proc write*(socket: UtpSocket, data: seq[byte]): Future[WriteResult] =
|
|||
let retFuture = newFuture[WriteResult]("UtpSocket.write")
|
||||
|
||||
if (socket.state != Connected):
|
||||
let res = Result[int, WriteError].err(WriteError(kind: SocketNotWriteable, currentState: socket.state))
|
||||
let res = WriteResult.err(WriteError(kind: SocketNotWriteable, currentState: socket.state))
|
||||
retFuture.complete(res)
|
||||
return retFuture
|
||||
|
||||
# fin should be last packet received by remote side, therefore trying to write
|
||||
# after sending fin is considered error
|
||||
if socket.sendFinRequested or socket.finSent:
|
||||
let res = Result[int, WriteError].err(WriteError(kind: FinSent))
|
||||
let res = WriteResult.err(WriteError(kind: FinSent))
|
||||
retFuture.complete(res)
|
||||
return retFuture
|
||||
|
||||
var bytesWritten = 0
|
||||
|
||||
if len(data) == 0:
|
||||
let res = Result[int, WriteError].ok(bytesWritten)
|
||||
let res = WriteResult.ok(bytesWritten)
|
||||
retFuture.complete(res)
|
||||
return retFuture
|
||||
|
||||
try:
|
||||
socket.eventQueue.putNoWait(SocketEvent(kind: WriteReq, data: data, writer: retFuture))
|
||||
socket.eventQueue.putNoWait(SocketEvent(
|
||||
kind: WriteReq, data: data, writer: retFuture))
|
||||
except AsyncQueueFullError as e:
|
||||
# this should not happen as out write queue is unbounded
|
||||
raiseAssert e.msg
|
||||
|
|
|
|||
Loading…
Reference in New Issue