punchd/punchd.nim

import asyncdispatch, asyncnet, os, strformat, strutils
from nativesockets import Domain, SockType, Protocol
import asyncutils
import message
import tables
import tcp_syni_initiator
import tcp_syni_responder
import tcp_nutss_initiator
import tcp_nutss_responder

from strutils import format, join
from nativesockets import setSockOptInt

type
  Punchd = ref object
    unixSocket: AsyncSocket
    initiators: Table[string, Initiator]
    responders: Table[string, Responder]

  Sigint = object of CatchableError

const PunchdSocket = "/tmp/punchd.socket"

proc handleSigint() {.noconv.} =
  raise newException(Sigint, "received SIGINT")

proc sendToClient(unixSock: AsyncSocket, msg: string,
                  cmsgs: seq[ControlMessage] = @[]) {.async.} =
  if not unixSock.isClosed():
    let unixFd = unixSock.getFd.AsyncFD
    await unixFd.asyncSendMsg(msg, cmsgs)

proc handleRequest(punchd: Punchd, line: string,
                   unixSock: AsyncSocket) {.async.} =
  var id: string
  var sock: AsyncSocket
  try:
    let args = line.parseArgs(4)
    id = args[1]

    case args[0]:
    of "initiate":
      proc progress(extraArgs: string) {.async.} =
        let msg = &"progress|{id}|{args[2]}|{args[3]}|{extraArgs}\n"
        await sendToClient(unixSock, msg)
      sock = await punchd.initiators[args[2]].initiate(args[3], progress)

    of "respond":
      sock = await punchd.responders[args[2]].respond(args[3])

    else:
      raise newException(ValueError, "invalid request")

    await sendToClient(unixSock, &"ok|{id}\n", @[fromFd(sock.getFd.AsyncFD)])
    sock.close()

  except PunchHoleError as e:
    await sendToClient(unixSock, &"error|{id}|{e.msg}\n")
  except KeyError, ValueError:
    unixSock.close

proc handleRequests(punchd: Punchd, userSock: AsyncSocket) {.async.} =
  while true:
    if userSock.isClosed:
      break
    let line = await userSock.recvLine(maxLength = 400)
    if line.len == 0:
      userSock.close()
      break
    asyncCheck punchd.handleRequest(line, userSock)

proc handleUsers(punchd: Punchd) {.async.} =
  while true:
    let user = await punchd.unixSocket.accept()
    asyncCheck punchd.handleRequests(user)

proc main() =
  setControlCHook(handleSigint)
  removeFile(PunchdSocket)
  let unixSocket = newAsyncSocket(AF_UNIX, SOCK_STREAM, IPPROTO_IP)
  unixSocket.bindUnix(PunchdSocket)
  unixSocket.listen()
  setFilePermissions(PunchdSocket,
                     {fpUserRead, fpUserWrite, fpGroupRead, fpGroupWrite,
                      fpOthersRead, fpOthersWrite})
  let punchd = Punchd(unixSocket: unixSocket)
  punchd.initiators["tcp-syni"] = initTcpSyniInitiator()
  punchd.initiators["tcp-nutss"] = initTcpNutssInitiator()
  punchd.responders["tcp-syni"] = initTcpSyniResponder()
  punchd.responders["tcp-nutss"] = initTcpNutssResponder()
  asyncCheck handleUsers(punchd)
  try:
    runForever()

  except Sigint:
    for i in punchd.initiators.values:
      waitFor i.cleanup()
    for r in punchd.responders.values:
      waitFor r.cleanup()
    punchd.unixSocket.close()
    removeFile(PunchdSocket)

when isMainModule:
  main()