52 lines
1.5 KiB
Nim
52 lines
1.5 KiB
Nim
import asyncdispatch, asyncnet, strformat
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from net import IpAddress, Port, `$`, `==`
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import port_prediction
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import puncher
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import utils
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export PunchHoleError
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type
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Attempt = object
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srcIp: IpAddress
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srcPort: Port
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dstIp: IpAddress
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dstPorts: seq[Port]
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TcpNutssResponder* = Puncher[Attempt]
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proc cleanup*(puncher: TcpNutssResponder) {.async.} =
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discard
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proc initTcpNutssResponder*(): TcpNutssResponder =
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TcpNutssResponder()
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proc connect(srcIp: IpAddress, srcPort: Port, dstIp: IpAddress, dstPort: Port,
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future: Future[AsyncSocket]) {.async.} =
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let sock = newAsyncSocket()
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sock.setSockOpt(OptReuseAddr, true)
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echo &"connect {srcIp}:{srcPort} -> {dstIp}:{dstPort}"
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sock.bindAddr(srcPort, $srcIp)
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try:
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await sock.connect($dstIp, dstPort)
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future.complete(sock)
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except OSError as e:
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echo &"connection {srcIP}:{srcPort.int} -> {dstIp}:{dstPort.int} failed: ", e.msg
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sock.close()
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proc respond*(puncher: TcpNutssResponder, srcPort: Port, dstIp: IpAddress,
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dstPorts: seq[Port]): Future[AsyncSocket] {.async.} =
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let localIp = getPrimaryIPAddr(dstIp)
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try:
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let connectFuture = newFuture[AsyncSocket]("respond")
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let portRange = predictPortRange(dstPorts)
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for dstPort in portRange:
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asyncCheck connect(localIp, srcPort, dstIp, dstPort, connectFuture)
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await connectFuture or sleepAsync(Timeout)
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if connectFuture.finished():
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result = connectFuture.read()
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else:
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raise newException(PunchHoleError, "timeout")
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except OSError as e:
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raise newException(PunchHoleError, e.msg)
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