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aiutp_pcb.erl
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aiutp_pcb.erl
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-module(aiutp_pcb).
-include("aiutp.hrl").
-export([new/3,
state/1,
process/2,
check_timeouts/1,
write/2,
close/1,
read/1,
connect/2,
accept/2,
closed/1,
flush/1]).
new(ConnIdRecv,ConnIdSend,Socket)->
CurMilli = aiutp_util:millisecond(),
#aiutp_pcb{time = CurMilli,
state = ?CS_IDLE,
socket = Socket,
conn_id_send = ConnIdSend,
conn_id_recv = ConnIdRecv,
last_got_packet = CurMilli,
last_sent_packet = CurMilli,
last_measured_delay = CurMilli + 16#70000000,
average_sample_time = CurMilli + 5000,
last_rwin_decay = CurMilli - ?MAX_WINDOW_DECAY,
our_hist = aiutp_delay:new(CurMilli),
their_hist = aiutp_delay:new(CurMilli),
rtt_hist = aiutp_delay:new(CurMilli),
max_window = ?PACKET_SIZE,
inbuf = aiutp_buffer:new(?OUTGOING_BUFFER_MAX_SIZE),
outbuf = aiutp_buffer:new(?OUTGOING_BUFFER_MAX_SIZE),
inque = aiutp_queue:new(),
outque = aiutp_queue:new()}.
state(#aiutp_pcb{state = State}) -> State.
closed(#aiutp_pcb{state = State})
when State == ?CS_RESET -> {closed,reset};
closed(#aiutp_pcb{state = State,
fin_sent = FinSent,
fin_sent_acked = FinSentAcked,
got_fin = GotFin,
got_fin_reached = GotFinReached,
cur_window_packets = CurWindowPackets
})
when State == ?CS_DESTROY->
if (FinSent and FinSentAcked) or
(GotFin and GotFinReached) -> {closed,normal};
FinSent and CurWindowPackets == 1 -> {closed,normal};
(FinSent == false) and
(GotFin == false)-> {closed,timeout};
true -> {closed,crash}
end;
closed(#aiutp_pcb{got_fin = GotFin,
got_fin_reached = GotFinReached}) ->
if (GotFin and GotFinReached) -> {closed,normal};
true -> not_closed
end.
process({Packet,TS},PCB)->
aiutp_net:schedule_ack(process(Packet#aiutp_packet.type,Packet,
PCB#aiutp_pcb{recv_time = TS})).
process(_,_,#aiutp_pcb{state = State} = PCB)
when (State == ?CS_DESTROY);
(State == ?CS_RESET) ->
PCB;
process(?ST_RESET,
#aiutp_packet{conn_id = ConnId},
#aiutp_pcb{conn_id_send = ConnIdSend,
conn_id_recv = ConnIdRecv,
close_requested = CloseRequested} = PCB)->
if (ConnIdSend == ConnId) or (ConnIdRecv == ConnId) ->
if CloseRequested == true -> PCB#aiutp_pcb{state = ?CS_DESTROY};
true -> PCB#aiutp_pcb{state = ?CS_RESET}
end;
true-> PCB
end;
%% 处理SYN
process(?ST_SYN,
#aiutp_packet{seq_nr = AckNR},
#aiutp_pcb{state = ?CS_IDLE} = PCB) ->
SeqNR = aiutp_util:bit16_random(),
PCB0 = PCB#aiutp_pcb{state = ?CS_SYN_RECV,
ack_nr = AckNR,
seq_nr = SeqNR,
fast_resend_seq_nr = SeqNR,
last_got_packet = aiutp_util:millisecond()},
aiutp_net:send_ack(PCB0);
process(?ST_SYN,
#aiutp_packet{seq_nr = AckNR},
#aiutp_pcb{state = ?CS_SYN_RECV,ack_nr = AckNR} = PCB) ->
PCB0 = PCB#aiutp_pcb{last_got_packet = aiutp_util:millisecond()},
aiutp_net:send_ack(PCB0);
%% 处理所有非RESET和非SYN
process(_,
#aiutp_packet{type = PktType,ack_nr = PktAckNR,conn_id = ConnId,seq_nr = PktSeqNR}=Packet,
#aiutp_pcb{state = State,seq_nr = SeqNR,cur_window_packets = CurWindowPackets} = PCB)->
% window packets size is used to calculate a minimum
% permissible range for received acks. connections with acks falling
% out of this range are dropped
CurrWindow = erlang:max(CurWindowPackets + ?ACK_NR_ALLOWED_WINDOW,?ACK_NR_ALLOWED_WINDOW),
MaxSeqNR = aiutp_util:bit16(SeqNR - 1),
MinSeqNR = aiutp_util:bit16(SeqNR -1 -CurrWindow),
if ((PktType /= ?ST_SYN) or (State /= ?CS_SYN_RECV)) and
(?WRAPPING_DIFF_16(MaxSeqNR,PktAckNR) < 0) or
(?WRAPPING_DIFF_16(PktAckNR, MinSeqNR) < 0) ->
PCB;
% ignore packets whose ack_nr is invalid. This would imply a spoofed address
% or a malicious attempt to attach the uTP implementation.
% acking a packet that hasn't been sent yet!
% SYN packets have an exception, since there are no previous packets
true -> process_packet(Packet,PCB)
end.
process_packet(#aiutp_packet{type = PktType,seq_nr = PktSeqNR,conn_id = ConnId,ack_nr = PktAckNR} = Packet,
#aiutp_pcb{state = State} = PCB)->
Now = aiutp_util:millisecond(),
PCB0 =
if State == ?CS_SYN_SENT ->
% if this is a syn-ack, initialize our ack_nr
% to match the sequence number we got from the other end
PCB#aiutp_pcb{ack_nr = aiutp_util:bit16(PktSeqNR - 1),
last_got_packet = Now,time = Now};
true -> PCB#aiutp_pcb{last_got_packet = Now,time = Now}
end,
%% 处理超出reorder范围的Packet
NextPktAckNR = aiutp_util:bit16(PCB0#aiutp_pcb.ack_nr + 1),
SeqDistance = aiutp_util:bit16(PktSeqNR - NextPktAckNR),
% seqnr is the number of packets past the expected
% packet this is. ack_nr is the last acked, seq_nr is the
% current. Subtracring 1 makes 0 mean "this is the next
% expected packet".
if SeqDistance >= ?REORDER_BUFFER_MAX_SIZE ->
if (SeqDistance >= (?SEQ_NR_MASK + 1 - ?REORDER_BUFFER_MAX_SIZE)) and
(PktType /= ?ST_STATE) -> PCB0#aiutp_pcb{ida = true};
true -> PCB0
end;
true -> process_packet_1(Packet,PCB0)
end.
%% 计算dulpicateAck
process_packet_1(#aiutp_packet{type = PktType,ack_nr = PktAckNR } = Packet,
#aiutp_pcb{cur_window_packets = CurWindowPackets,
duplicate_ack = DuplicateAck,
seq_nr = SeqNR} = PCB)
when CurWindowPackets > 0->
Seq = aiutp_util:bit16(SeqNR -CurWindowPackets -1),
if (PktAckNR == Seq) and
(PktType == ?ST_STATE) ->
if DuplicateAck + 1 == ?DUPLICATE_ACKS_BEFORE_RESEND ->
PCB0 = aiutp_net:send_packet(aiutp_buffer:head(PCB#aiutp_pcb.outbuf),
PCB#aiutp_pcb{duplicate_ack = 0}),
process_packet_2(Packet,PCB0);
true -> process_packet_2(Packet,PCB#aiutp_pcb{duplicate_ack = DuplicateAck + 1})
end;
true ->
process_packet_2(Packet,PCB#aiutp_pcb{duplicate_ack = 0})
end;
% if we get the same ack_nr as in the last packet
% increase the duplicate_ack counter, otherwise reset it to 0.
% It's important to only count ACKs in ST_STATE packets. Any other
% packet (primarily ST_DATA) is likely to have been sent because of the
% other end having new outgoing data, not in response to incoming data.
% For instance, if we're receiving a steady stream of payload with no
% outgoing data, and we suddently have a few bytes of payload to send (say,
% a bittorrent HAVE message), we're very likely to see 3 duplicate ACKs
% immediately after sending our payload packet. This effectively disables
% the fast-resend on duplicate-ack logic for bi-directional connections
% (except in the case of a selective ACK). This is in line with BSD4.4 TCP
% implementation.
process_packet_1(Packet,PCB)-> process_packet_2(Packet,PCB).
caculate_acked_bytes(Acc,Now,AckedPackets,SAckedPackets)->
Fun = fun(WrapPacket,{Bytes,RTT})->
TimeSent = WrapPacket#aiutp_packet_wrap.time_sent,
RTT0 =
if TimeSent < Now -> erlang:min(RTT,(Now - TimeSent));
true -> erlang:min(RTT,50000)
end,
{Bytes + WrapPacket#aiutp_packet_wrap.payload,RTT0}
end,
Acc0 = lists:foldl(Fun,Acc, AckedPackets),
lists:foldl(Fun, Acc0, SAckedPackets).
cc_control(Now,AckedBytes,RTT,
#aiutp_pcb{our_hist = OurHist,target_delay = TargetDelay,
clock_drift = ClockDrift,max_window = MaxWindow,
last_maxed_out_window = LastMaxedOutWindow,
slow_start = SlowStart,ssthresh = SSThresh} = PCB)->
OurHistValue = aiutp_delay:value(OurHist),
OurDelay = erlang:min(aiutp_util:bit32(RTT),OurHistValue),
Target =
if TargetDelay =< 0 -> 100000;
true -> TargetDelay
end,
Penalty =
if ClockDrift < -200000 -> (200000 + ClockDrift) div 7;
true -> 0
end,
OurDelay0 = OurDelay + Penalty,
OffTarget = Target - OurDelay0,
Win0 = erlang:min(AckedBytes,MaxWindow),
Win1 = erlang:max(AckedBytes,MaxWindow),
WindowFactor = Win0 / Win1,
DelayFactor = OffTarget / Target,
ScaledGain = ?MAX_CWND_INCREASE_BYTES_PER_RTT * WindowFactor * DelayFactor,
ScaledGain0 =
if (ScaledGain > 0) and (Now - LastMaxedOutWindow > 3000) -> 0;
true -> erlang:trunc(ScaledGain)
end,
LedbetCwnd = erlang:max(?MIN_WINDOW_SIZE,(MaxWindow + ScaledGain0)),
{SlowStart0,SSThresh0,MaxWindow0} =
if SlowStart ->
SSCwnd = MaxWindow + erlang:trunc(WindowFactor* ?MIN_WINDOW_SIZE),
if SSCwnd > SSThresh-> {false,SSThresh,MaxWindow};
OurDelay0 > Target * 0.9 -> {false,MaxWindow,MaxWindow};
true -> {SlowStart,SSThresh,erlang:max(SSCwnd,LedbetCwnd)}
end;
true -> {SlowStart,SSThresh,LedbetCwnd}
end,
PCB#aiutp_pcb{slow_start = SlowStart0,ssthresh = SSThresh0,
target_delay = (Target * 3 + OurDelay0) div 4,
max_window = aiutp_util:clamp(MaxWindow0,?MIN_WINDOW_SIZE,?OUTGOING_BUFFER_MAX_SIZE*?PACKET_SIZE)}.
ack_packet(MicroNow,#aiutp_packet_wrap{transmissions = Transmissions,
time_sent = TimeSent,
need_resend = NeedResend,payload = Payload},
{Now,CurWindow,RTT,RTO,RTTVar,RTTHist}) ->
{RTT1,RTTVar1,RTO0,RTTHist1} =
if Transmissions == 1 ->
{RTT0,RTTVar0,ERTT} = aiutp_rtt:caculate_rtt(RTT,RTTVar,TimeSent,MicroNow),
RTTHist0 =
if RTT /= 0 -> aiutp_delay:add_sample(ERTT,Now,RTTHist);
true -> RTTHist
end,
{RTT0,RTTVar0,aiutp_util:clamp((RTT0 + RTTVar0 * 4),600,6000),RTTHist0};
true -> {RTT,RTTVar,RTO,RTTHist}
end,
CurWindow0 =
if NeedResend == false -> CurWindow - Payload;
true -> CurWindow
end,
{Now,CurWindow0,RTT1,RTO0,RTTVar1,RTTHist1}.
maybe_decay_win(#aiutp_pcb {time = Now,
max_window = MaxWindow,
last_rwin_decay = LastRWinDecay
} = PCB)->
if (Now - LastRWinDecay) < ?MAX_WINDOW_DECAY -> PCB;
true ->
MaxWindow0 = erlang:trunc(MaxWindow * 0.5),
MaxWindow1 =
if MaxWindow0 < ?MIN_WINDOW_SIZE -> ?MIN_WINDOW_SIZE;
true -> MaxWindow0
end,
%io:format("decay win to ~p~n",[MaxWindow1]),
PCB#aiutp_pcb{
slow_start = false,
ssthresh = MaxWindow1,
max_window = MaxWindow1,
last_rwin_decay = Now
}
end.
%% 此处实现和C++版本有差异,会浪费带宽,但是不是Bug
%% 需要在后期进行优化
selective_ack_packet(_,_,#aiutp_pcb{cur_window_packets = CurWindowPackets} = PCB)
when CurWindowPackets == 0-> PCB;
selective_ack_packet([],_,PCB)-> PCB;
selective_ack_packet(SAckedPackets,
MicroNow,
#aiutp_pcb{seq_nr = SeqNR,cur_window_packets = CurWindowPackets} = PCB)->
Now0 = aiutp_util:millisecond(),
{_,CurWindow0,RTT0,RTO0,RTTVar0,RTTHist0} =
lists:foldr(fun(I,AccPCB) -> ack_packet(MicroNow,I,AccPCB) end,
{Now0,PCB#aiutp_pcb.cur_window,PCB#aiutp_pcb.rtt,PCB#aiutp_pcb.rto,
PCB#aiutp_pcb.rtt_var,PCB#aiutp_pcb.rtt_hist}, SAckedPackets),
PCB0 = PCB#aiutp_pcb{cur_window = CurWindow0,
rtt = RTT0,rtt_var = RTTVar0,
rtt_hist = RTTHist0, rto = RTO0,retransmit_count = 0,
retransmit_timeout = RTO0, rto_timeout = RTO0 + Now0},
[El|_] = SAckedPackets,
MinSeq = aiutp_util:bit16(SeqNR - CurWindowPackets),
%% 计算出重发最大的序列号
Packet = El#aiutp_packet_wrap.packet,
MaxSeq = aiutp_util:bit16(Packet#aiutp_packet.seq_nr - 1),
if ?WRAPPING_DIFF_16(MaxSeq,MinSeq) > ?DUPLICATE_ACKS_BEFORE_RESEND ->
{Sent,LastSeq,PCB1} = aiutp_net:send_n_packets(MinSeq, MaxSeq, 4, PCB0),
PCB2 = PCB1#aiutp_pcb{fast_resend_seq_nr = aiutp_util:bit16(LastSeq + 1),
duplicate_ack = erlang:length(SAckedPackets)},
if Sent > 0 -> maybe_decay_win(PCB2);
true -> PCB2
end;
true -> PCB0
end.
%% 流控和重传
process_packet_2(#aiutp_packet{type = PktType,ack_nr = PktAckNR,
wnd = PktMaxWindowUser} = Packet,
#aiutp_pcb{state = State,
time = Now,
fast_resend_seq_nr = FastResendSeqNR,
fast_timeout = FastTimeout,
zerowindow_time = ZeroWindowTime,
fin_sent = FinSent,close_requested = CloseRequested,
fin_sent_acked = FinSentAcked,
recv_time = RecvTime} = PCB)->
{AckedPackets,SAckedPackets,PCB0} = aiutp_tx:pick_acked(Packet,PCB),
{AckedBytes,MinRTT} = caculate_acked_bytes({0,?RTT_MAX},RecvTime,AckedPackets,SAckedPackets),
{ActualDelay,PCB1} = aiutp_rtt:caculate_delay(Now,RecvTime,Packet,PCB0),
OurHist = PCB1#aiutp_pcb.our_hist,
OurHistValue = aiutp_delay:value(OurHist),
OurHist0 =
if OurHistValue > MinRTT -> aiutp_delay:shift(aiutp_util:bit32(OurHistValue - MinRTT),OurHist);
true -> OurHist
end,
PCB2 =
if (ActualDelay /= 0) and (AckedBytes > 0) ->
cc_control(Now,AckedBytes,MinRTT,PCB1#aiutp_pcb{our_hist = OurHist0});
true-> PCB1#aiutp_pcb{our_hist = OurHist0}
end,
ZeroWindowTime0 =
if PktMaxWindowUser == 0 -> Now + 15000;
true -> ZeroWindowTime
end,
State0 =
if (PktType == ?ST_DATA) and
(State == ?CS_SYN_RECV) -> ?CS_CONNECTED;
true -> State
end,
{State1,FinSentAcked0} =
if (PktType == ?ST_STATE) and
(State0 == ?CS_SYN_SENT) -> {?CS_CONNECTED,false};
(FinSent == true) and (PCB2#aiutp_pcb.cur_window_packets == 0) ->
if CloseRequested -> {?CS_DESTROY,true};
true -> {State0,true}
end;
true -> {State0,FinSentAcked}
end,
PktAckNR0 = aiutp_util:bit16(PktAckNR + 1),
FastResendSeqNR0 =
if ?WRAPPING_DIFF_16(FastResendSeqNR,PktAckNR0) < 0 -> PktAckNR0;
true -> FastResendSeqNR
end,
{_,CurWindow0,RTT0,RTO0,RTTVar0,RTTHist0} =
lists:foldr(fun(I,AccPCB) -> ack_packet(RecvTime,I,AccPCB) end,
{Now,PCB2#aiutp_pcb.cur_window,PCB2#aiutp_pcb.rtt,PCB2#aiutp_pcb.rto,
PCB2#aiutp_pcb.rtt_var,PCB2#aiutp_pcb.rtt_hist}, AckedPackets),
Now0 = aiutp_util:millisecond(),
PCB3 = PCB2#aiutp_pcb{max_window_user = PktMaxWindowUser,
state = State1,
fin_sent_acked = FinSentAcked0,
fast_resend_seq_nr = FastResendSeqNR0,
zerowindow_time = ZeroWindowTime0,
cur_window = CurWindow0,
rtt = RTT0,rtt_var = RTTVar0,
rtt_hist = RTTHist0, rto = RTO0,retransmit_count = 0,
retransmit_timeout = RTO0, rto_timeout = RTO0 + Now0},
PCB4 =
if PCB3#aiutp_pcb.cur_window_packets == 1 ->
aiutp_net:send_packet(aiutp_buffer:head(PCB3#aiutp_pcb.outbuf),PCB3);
true -> PCB3
end,
PCB5 =
if FastTimeout ->
if ?WRAPPING_DIFF_16(PCB4#aiutp_pcb.seq_nr, PCB4#aiutp_pcb.cur_window_packets) /= FastResendSeqNR0 ->
PCB4#aiutp_pcb{fast_timeout = false};
true -> aiutp_net:send_packet(aiutp_buffer:head(PCB4#aiutp_pcb.outbuf),
PCB4#aiutp_pcb{fast_resend_seq_nr = aiutp_util:bit16(FastResendSeqNR0 +1)})
end;
true-> PCB4
end,
PCB6 = selective_ack_packet(SAckedPackets,RecvTime,PCB5),
process_packet_3(Packet, PCB6).
%% 处理ST_STATE以及CS_CONNECTED状态确认
process_packet_3(#aiutp_packet{type = PktType} = Packet,
#aiutp_pcb{state = State} = PCB)->
{ISFull,PCB0} = aiutp_net:is_full(-1,PCB),
PCB1 =
if (ISFull == false) and
(State == ?CS_CONNECTED_FULL) -> PCB0#aiutp_pcb{state = ?CS_CONNECTED};
true -> PCB0
end,
if PktType == ?ST_STATE-> PCB1;
(State /= ?CS_CONNECTED) and (State /= ?CS_CONNECTED_FULL)-> PCB1;
true -> process_packet_4(Packet, PCB1)
end.
process_packet_4(#aiutp_packet{type = PktType,seq_nr = PktSeqNR} = Packet,
#aiutp_pcb{got_fin = GotFin} = PCB)->
PCB0 =
if (PktType == ?ST_FIN) and (GotFin == false)->
PCB#aiutp_pcb{got_fin = true,eof_pkt = PktSeqNR};
true -> PCB
end,
aiutp_rx:in(Packet, PCB0).
check_timeouts(#aiutp_pcb{state = State} = PCB)
when State /= ?CS_DESTROY;
State /= ?CS_RESET->
Now = aiutp_util:millisecond(),
PCB0 = aiutp_net:flush_packets(PCB),
check_timeouts_0(PCB0#aiutp_pcb{time = Now});
check_timeouts(PCB) -> PCB.
check_timeouts_0(#aiutp_pcb{state = State} = PCB)
when State == ?CS_UNINITIALIZED ;
State == ?CS_IDLE;
State == ?CS_RESET-> PCB;
check_timeouts_0(#aiutp_pcb{time =Now,
state = State,
zerowindow_time = ZeroWindowTime,
max_window_user = MaxWindowUser,
rto_timeout = RTOTimeout,
fin_sent = FinSent,
brust = Brust} = PCB)->
PCB0 =
if (MaxWindowUser == 0 ) and
(Now - ZeroWindowTime >=0) -> PCB#aiutp_pcb{max_window_user = ?MIN_WINDOW_SIZE};
true -> PCB
end,
{Continue,PCB1} =
if (RTOTimeout >0) and
(Now - RTOTimeout >= 0 ) ->
check_timeouts_1(PCB0);
true -> {true,PCB0}
end,
if Continue == true ->
PCBKeepAlive =
if (FinSent == false) and
((State == ?CS_CONNECTED) or (State == ?CS_CONNECTED_FULL)) and
(Now - PCB1#aiutp_pcb.last_sent_packet >= ?KEEPALIVE_INTERVAL) ->
aiutp_net:send_keep_alive(PCB1);
(FinSent == false) and
(Brust == true) and (Now - PCB1#aiutp_pcb.last_sent_packet >= 5000)->
aiutp_net:send_keep_alive(PCB1);
true -> PCB1
end,
PCBFlush =
if PCBKeepAlive#aiutp_pcb.cur_window_packets == 0 ->
aiutp_net:flush_queue(PCBKeepAlive);
true -> PCBKeepAlive
end,
{ISFull,PCB2} = aiutp_net:is_full(-1,PCBFlush),
if (State == ?CS_CONNECTED_FULL) and
(ISFull == false) ->PCB2#aiutp_pcb{state = ?CS_CONNECTED};
true -> PCB2
end;
true -> PCB1
end.
mark_need_resend(_,CurWindow,-1,OutBuf)-> {CurWindow,OutBuf};
mark_need_resend(0,CurWindow,_,OutBuf)-> {CurWindow,OutBuf};
mark_need_resend(CurWindowPackets,CurWindow,Iter,OutBuf) ->
Next = aiutp_buffer:next(Iter, OutBuf),
WrapPacket = aiutp_buffer:data(Iter, OutBuf),
#aiutp_packet_wrap{
transmissions = Transmissions,
need_resend = NeedResend,
payload = Payload
} = WrapPacket,
if (NeedResend == true) or (Transmissions == 0) ->
mark_need_resend(CurWindowPackets - 1,CurWindow,Next,OutBuf);
true ->
WrapPacket0 = WrapPacket#aiutp_packet_wrap{need_resend = true},
OutBuf0 = aiutp_buffer:replace(Iter,WrapPacket0,OutBuf),
mark_need_resend(CurWindowPackets - 1,CurWindow - Payload,Next,OutBuf0)
end.
check_timeouts_1(#aiutp_pcb{state = State} = PCB)
when State == ?CS_SYN_RECV ->
{fasle,PCB#aiutp_pcb{state = ?CS_DESTROY}};
check_timeouts_1(#aiutp_pcb{time = Now,
last_got_packet = LastGotPacket,
close_requested = CloseRequested} = PCB)
when (LastGotPacket > 0),(Now - LastGotPacket > ?KEEPALIVE_INTERVAL * 2) ->
io:format("CLOSED due to MAX Keepalive: ~p~n",[LastGotPacket]),
if CloseRequested == true -> {false,PCB#aiutp_pcb{state = ?CS_DESTROY}};
true -> {false,PCB#aiutp_pcb{state = ?CS_RESET}}
end;
check_timeouts_1(#aiutp_pcb{rtt = RTT,close_requested = CloseRequested} = PCB)
when (RTT > 6000) ->
io:format("CLOSED due to MAX RTT: ~p~n",[RTT]),
if CloseRequested == true -> {false,PCB#aiutp_pcb{state = ?CS_DESTROY}};
true -> {false,PCB#aiutp_pcb{state = ?CS_RESET}}
end;
check_timeouts_1(#aiutp_pcb{state = State,
close_requested = CloseRequested,
retransmit_count = RetransmitCount,
brust = false} = PCB)
when (RetransmitCount >= 4);
((State == ?CS_SYN_SENT) and RetransmitCount > 2) ->
io:format("CLOSED due to MAX retransmit: ~p~n",[RetransmitCount]),
if CloseRequested == true -> {false,PCB#aiutp_pcb{state = ?CS_DESTROY}};
true -> {false,PCB#aiutp_pcb{state = ?CS_RESET}}
end;
check_timeouts_1(#aiutp_pcb{state = State,
close_requested = CloseRequested,
retransmit_count = RetransmitCount,
brust = true} = PCB)
when (RetransmitCount >= 40);
((State == ?CS_SYN_SENT) and RetransmitCount > 10) ->
io:format("CLOSED due to MAX retransmit: ~p~n",[RetransmitCount]),
if CloseRequested == true -> {false,PCB#aiutp_pcb{state = ?CS_DESTROY}};
true -> {false,PCB#aiutp_pcb{state = ?CS_RESET}}
end;
check_timeouts_1(#aiutp_pcb{time=Now,
retransmit_timeout = RetransmitTimeout,
cur_window_packets = CurWindowPackets,
cur_window = CurWindow,
max_window = MaxWindow,
outbuf = OutBuf,
seq_nr = SeqNR,
brust = Brust,
retransmit_count = RetransmitCount} = PCB) ->
NewTimeout = RetransmitTimeout * 2,
PCB0 =
if (CurWindowPackets == 0) and
(MaxWindow > ?PACKET_SIZE)->
PCB#aiutp_pcb{retransmit_timeout = NewTimeout,rto_timeout = Now + NewTimeout,
duplicate_ack = 0,
max_window = erlang:max((MaxWindow * 2 div 3), ?MIN_WINDOW_SIZE)};
true -> PCB#aiutp_pcb{retransmit_timeout = NewTimeout,rto_timeout = Now + NewTimeout,
duplicate_ack = 0,
max_window = erlang:max((MaxWindow div 2), ?MIN_WINDOW_SIZE),
slow_start = true}
end,
if CurWindowPackets > 0 ->
Iter = aiutp_buffer:head(OutBuf),
{CurWindow0,OutBuf0} = mark_need_resend(CurWindowPackets,CurWindow,Iter,OutBuf),
PCB1 = PCB0#aiutp_pcb{
cur_window = CurWindow0,
outbuf = OutBuf0,
retransmit_count = RetransmitCount + 1,
fast_timeout = true,
timeout_seq_nr = SeqNR
},
PCB2 =
if Brust == true -> aiutp_net:flush_packets(PCB);
true -> aiutp_net:send_packet(aiutp_buffer:head(OutBuf0), PCB1)
end,
{true,PCB2};
true -> {true,PCB0}
end.
write(_,#aiutp_pcb{state = State} = PCB)
when (State /= ?CS_CONNECTED),
(State /= ?CS_CONNECTED_FULL) ->
{{error,not_connected},PCB};
write(_,#aiutp_pcb{fin_sent = FinSent} = PCB)
when FinSent == true ->
{{error,closed},PCB};
write(Data,PCB) -> aiutp_tx:in(Data,PCB#aiutp_pcb{time = aiutp_util:millisecond()}).
close(#aiutp_pcb{state = State } = PCB)
when State == ?CS_UNINITIALIZED;
State == ?CS_IDLE;
State == ?CS_DESTROY -> PCB#aiutp_pcb{state = ?CS_DESTROY};
close(#aiutp_pcb{state = State,rto = RTO} = PCB)
when State == ?CS_SYN_SENT ->
PCB#aiutp_pcb{
rto_timeout = erlang:min(RTO * 2, 60) + aiutp_util:millisecond(),
state = ?CS_DESTROY};
close(#aiutp_pcb{state = State} = PCB)
when State == ?CS_SYN_RECV ->
PCB#aiutp_pcb{state = ?CS_DESTROY};
close(#aiutp_pcb{fin_sent_acked = FinSentAcked,fin_sent = FinSent} = PCB)->
PCB0 = PCB#aiutp_pcb{read_shutdown = true,close_requested = true},
if FinSent == false ->
aiutp_net:send_fin(PCB0#aiutp_pcb{fin_sent = true});
FinSentAcked == true -> PCB0#aiutp_pcb{state = ?CS_DESTROY};
true -> PCB0
end.
read(#aiutp_pcb{inque = InQue,max_window = MaxWindow,
inbuf = InBuf,last_rcv_win = LastRcvWin} = PCB)->
L = aiutp_queue:to_list(InQue),
WindowSize = aiutp_net:window_size(MaxWindow, InBuf),
Now = aiutp_util:millisecond(),
PCB0 =
if WindowSize > LastRcvWin->
if LastRcvWin == 0 -> aiutp_net:send_ack(PCB#aiutp_pcb{time = Now});
true -> PCB#aiutp_pcb{time=Now,ida = true}
end;
true -> PCB#aiutp_pcb{time = Now}
end,
QueSize = aiutp_queue:size(InQue),
if QueSize > 0 ->
{lists:foldl(
fun(Bin,Acc) -> <<Acc/binary,Bin/binary>> end,
<<>>,L),PCB0#aiutp_pcb{inque = aiutp_queue:new()}};
true -> {undefined,PCB0}
end.
connect(Socket,ConnIdRecv)->
ConnIdSend = aiutp_util:bit16(ConnIdRecv + 1),
PCB = new(ConnIdRecv,ConnIdSend,Socket),
#aiutp_pcb{max_window = MaxWindow,inbuf = InBuf,
conn_id_recv = ConnId,outbuf = OutBuf} = PCB,
Now = aiutp_util:millisecond(),
SeqNR = aiutp_util:bit16_random(),
WindowSize = aiutp_net:window_size(MaxWindow, InBuf),
Packet = aiutp_packet:syn(SeqNR),
Packet0 = Packet#aiutp_packet{conn_id = ConnId,wnd = WindowSize,
seq_nr = SeqNR},
WrapPacket = #aiutp_packet_wrap{packet = Packet0},
OutBuf0 = aiutp_buffer:append(WrapPacket, OutBuf),
Iter = aiutp_buffer:head(OutBuf0),
PCB0 = PCB#aiutp_pcb{state = ?CS_SYN_SENT,
time=Now,
retransmit_timeout = 3000,
rto_timeout = 3000 + Now,
last_rcv_win = WindowSize,
outbuf = OutBuf0, cur_window_packets = 1,
seq_nr = SeqNR + 1},
aiutp_net:send_packet(Iter, PCB0).
accept(Socket,{#aiutp_packet{conn_id = ConnIdSend},_} = Packet)->
ConnIdRecv = aiutp_util:bit16(ConnIdSend + 1),
PCB = new(ConnIdRecv,ConnIdSend,Socket),
PCB1 = process(Packet,PCB),
{ConnIdRecv,PCB1}.
flush(PCB)-> aiutp_net:flush_queue(PCB).