hans-2.1.0.0: src/Network/TCP/Aux/Output.hs
{-# LANGUAGE ScopedTypeVariables #-}
{--
Copyright (c) 2006, Peng Li
2006, Stephan A. Zdancewic
All rights reserved.
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modification, are permitted provided that the following conditions are
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* Redistributions of source code must retain the above copyright
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* Redistributions in binary form must reproduce the above copyright
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* Neither the name of the copyright owners nor the names of its
contributors may be used to endorse or promote products derived from
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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 COPYRIGHT
OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
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LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
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--}
module Network.TCP.Aux.Output where
import Hans.Message.Tcp
import Network.TCP.Type.Base
import Network.TCP.Type.Timer
import Network.TCP.Type.Datagram as Datagram
import Network.TCP.Type.Socket
import Network.TCP.Type.Syscall
import Network.TCP.Aux.Param
import Network.TCP.Aux.Misc
import Hans.Layer.Tcp.Monad
import Foreign
import Control.Exception
import Control.Monad
make_syn_segment :: Time -> TCPSocket t -> Timestamp -> TCPSegment
make_syn_segment curr_time sock (ts_val::Timestamp) =
let ws = request_r_scale $ cb sock -- should assert it's <= tcp_maxwinscale ?
mss = t_advmss $ cb $ sock
ts = do_tcp_options curr_time (tf_req_tstmp $ cb sock) (ts_recent $ cb_time $ sock ) ts_val
hdr =
set_tcp_mss mss $
set_tcp_ws ws $
set_tcp_ts ts $ emptyTcpHeader
{ tcpSeqNum = TcpSeqNum (seq_val (iss (cb sock)))
, tcpAckNum = TcpAckNum 0
, tcpSyn = True
, tcpWindow = fromIntegral (rcv_wnd (cb_rcv sock))
}
in mkTCPSegment'
(local_addr (cb sock)) (remote_addr (cb sock)) hdr bufferchain_empty
make_syn_ack_segment curr_time sock (addrfrom::TCPAddr) (addrto::TCPAddr) (ts_val::Timestamp) =
let urp_any = 0
tcb = cb sock
win = rcv_wnd (cb_rcv sock) -- `shiftR` (rcv_scale $ cb sock)
ws = if tf_doing_ws tcb then Just (rcv_scale tcb) else Nothing
mss = t_advmss tcb
ts = do_tcp_options curr_time (tf_req_tstmp tcb) (ts_recent $ cb_time sock) ts_val
hdr =
set_tcp_mss mss $
set_tcp_ws ws $
set_tcp_ts ts $ emptyTcpHeader
{ tcpSeqNum = TcpSeqNum (seq_val (iss tcb))
, tcpAckNum = TcpAckNum (fseq_val (rcv_nxt (cb_rcv sock)))
, tcpAck = True
, tcpSyn = True
, tcpWindow = fromIntegral win
, tcpUrgentPointer = urp_any
}
in mkTCPSegment' addrfrom addrto hdr bufferchain_empty
make_ack_segment curr_time sock (fin::Bool) (ts_val::Timestamp) =
let urp_garbage = 0
tcb = cb sock
win = (rcv_wnd $ cb_rcv sock) `shiftR` (rcv_scale tcb)
ts = do_tcp_options curr_time (tf_req_tstmp tcb) (ts_recent $ cb_time sock) ts_val
sn | fin = snd_una (cb_snd sock)
| otherwise = snd_nxt (cb_snd sock)
hdr =
set_tcp_ts ts $ emptyTcpHeader
{ tcpSeqNum = TcpSeqNum (seq_val sn)
, tcpAckNum = TcpAckNum (fseq_val (rcv_nxt (cb_rcv sock)))
, tcpAck = True
, tcpFin = fin
, tcpWindow = fromIntegral win
, tcpUrgentPointer = urp_garbage
}
in mkTCPSegment' (local_addr tcb) (remote_addr tcb) hdr bufferchain_empty
bsd_make_phantom_segment curr_time sock (addrfrom::TCPAddr) (addrto::TCPAddr) (ts_val::Timestamp) (cantsendmore::Bool) =
let urp_garbage = 0
tcb = cb sock
scb = cb_snd sock
rcb = cb_rcv sock
win = (rcv_wnd rcb) `shiftR` (rcv_scale tcb)
fin = (cantsendmore && seq_lt (snd_una scb) (seq_minus (snd_max scb) 1))
ts = do_tcp_options curr_time (tf_req_tstmp tcb) (ts_recent $ cb_time sock) ts_val
sn | fin = snd_una scb
| otherwise = snd_max scb
hdr =
set_tcp_ts ts emptyTcpHeader
{ tcpSourcePort = TcpPort 0
, tcpDestPort = TcpPort 0
, tcpSeqNum = TcpSeqNum (seq_val sn)
, tcpAckNum = TcpAckNum (fseq_val (rcv_nxt rcb))
, tcpFin = fin
, tcpWindow = fromIntegral win
, tcpUrgentPointer = urp_garbage
}
in
mkTCPSegment' addrfrom addrto hdr bufferchain_empty
make_rst_segment_from_cb sock (addrfrom::TCPAddr) (addrto::TCPAddr) =
let hdr = emptyTcpHeader
{ tcpSourcePort = TcpPort 0
, tcpDestPort = TcpPort 0
, tcpSeqNum = TcpSeqNum (seq_val (snd_nxt (cb_snd sock)))
, tcpAckNum = TcpAckNum (fseq_val (rcv_nxt (cb_rcv sock)))
, tcpAck = False
, tcpRst = False
}
in mkTCPSegment' addrfrom addrto hdr bufferchain_empty
make_rst_segment_from_seg (seg::TCPSegment) =
let tcp_ACK' = not (tcp_ACK seg)
seq' = if tcp_ACK seg then tcp_ack seg else 0
ack' = if tcp_ACK'
then let s1 = tcp_seq seg
in s1 `seq_plus` bufc_length (tcp_data seg)
`seq_plus` (if tcp_SYN seg then 1 else 0)
else 0
hdr = emptyTcpHeader
{ tcpSeqNum = TcpSeqNum seq'
, tcpAckNum = TcpAckNum ack'
, tcpAck = tcp_ACK'
, tcpRst = True
}
in
mkTCPSegment' (tcp_src seg) (tcp_dst seg) hdr bufferchain_empty
dropwithreset (seg::TCPSegment) =
if tcp_RST seg then []
else let seg' = make_rst_segment_from_seg seg
in [TCPMessage seg']
dropwithreset_ignore_or_fail = dropwithreset
tcp_close_temp sock =
sock { cb = (cb sock) { cantrcvmore = True
, cantsndmore = True
, local_addr = TCPAddr (IPAddr 0,0)
, remote_addr = TCPAddr (IPAddr 0,0)
, bsd_cantconnect = True
}
, st = CLOSED
, cb_snd = (cb_snd sock) { sndq = bufferchain_empty }
}
tcp_close :: SocketID -> HMonad t ()
tcp_close sid =
do b <- has_sock sid
when b $ do
sock <- lookup_sock sid
let pending_tasks = waiting_list sock
has_parent = (get_local_port $ parent_id $ cb sock) /= 0
let result = map (\(_,cont) -> cont (SockError "tcpclose")) pending_tasks
emit_ready result
delete_sock sid
when (not has_parent) $ free_local_port $ get_local_port sid
tcp_drop_and_close :: SocketID -> HMonad t ()
tcp_drop_and_close sid =
do b <- has_sock sid
when b $ do
sock <- lookup_sock sid
let outsegs = if st sock `notElem` [CLOSED,LISTEN,SYN_SENT]
then [TCPMessage $ make_rst_segment_from_cb
(sock) (local_addr $ cb sock) (remote_addr $ cb sock)]
else []
emit_segs outsegs
tcp_close sid
alloc_local_port :: HMonad t (Maybe Port)
alloc_local_port = do
h <- get_host
case local_ports h of
[] -> return Nothing
port:rest -> do put_host $ h { local_ports = rest }
return $ Just port
free_local_port port =
modify_host $ \h -> h { local_ports = port:(local_ports h) }