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|
-- |
--
-- This module defines three tasks intended to be run in separate threads:
--
-- * 'acceptContact'
--
-- * 'persueContact'
--
-- * 'freshenContact'
--
{-# LANGUAGE LambdaCase #-}
module Connection.Tox.Threads where
import Connection
-- import Connection.Tox
import Data.IP (IP)
import Network.Tox.Crypto.Transport
import Network.Tox.NodeId
-- import Network.Tox.DHT.Handlers (nodeSearch)
import Network.Socket
import Network.Kademlia.Search
import Network.Kademlia.Routing (BucketList)
import Control.Concurrent.STM
import Control.Monad
import Data.Function
import Data.Functor.Identity
import System.Timeout
-- | This type indicates the progress of a tox encrypted friend link
-- connection. Two scenarios are illustrated below. The parenthesis show the
-- current 'G.Status' 'ToxProgress' of the session.
--
--
-- Perfect handshake scenario:
--
-- Peer 1 Peer 2
-- (InProgress AcquiringCookie) (Dormant/InProgress AcquiringCookie)
-- Cookie request ->
-- <- Cookie response
-- (InProgress AwaitingHandshake) (Dormant/InProgress AcquiringCookie)
-- Handshake packet ->
-- * accepts connection
-- (InProgress AwaitingSessionPacket)
-- <- Handshake packet
-- *accepts connection
-- (InProgress AwaitingSessionPacket)
-- Encrypted packet -> <- Encrypted packet
-- *confirms connection *confirms connection
-- (Established) (Established)
--
-- Connection successful.
--
-- Encrypted packets -> <- Encrypted packets
--
--
--
--
-- More realistic handshake scenario:
-- Peer 1 Peer 2
-- (InProgress AcquiringCookie) (Dormant/InProgress AcquiringCookie)
-- Cookie request -> *packet lost*
-- Cookie request ->
-- <- Cookie response
-- (InProgress AwaitingHandshake) (Dormant/InProgress AcquiringCookie)
--
-- *Peer 2 randomly starts new connection to peer 1
-- (InProgress AcquiringCookie)
-- <- Cookie request
-- Cookie response ->
-- (InProgress AwaitingHandshake)
--
-- Handshake packet -> <- Handshake packet
-- *accepts connection * accepts connection
-- (InProgress AwaitingSessionPacket) (InProgress AwaitingSessionPacket)
--
-- Encrypted packet -> <- Encrypted packet
-- *confirms connection *confirms connection
-- (Established) (Established)
--
-- Connection successful.
--
-- Encrypted packets -> <- Encrypted packets
data ToxProgress
= AwaitingDHTKey -- ^ Waiting to receive their DHT key.
| AcquiringIPAddress -- ^ Searching DHT to obtain their node's IP & port.
| AcquiringCookie -- ^ Attempting to obtain a cookie.
| AwaitingHandshake -- ^ Waiting to receive a handshake.
| AwaitingSessionPacket -- ^ Connection is "accepted" but not yet "confirmed".
deriving (Eq,Ord,Enum,Show)
type NodeSearch = Search NodeId (IP,PortNumber) () NodeInfo NodeInfo
data AcceptContactMethods = AcceptContactMethods
{ getHandshake :: STM (Handshake Identity)
, handshakeIsSuitable :: Handshake Identity -> STM Bool
, transitionToState :: Status ToxProgress -> STM ()
}
-- | Invokes an STM action on each incoming handshake.
--
-- Does not return until getPolicy yields RefusingToConnect.
acceptContact :: STM Policy -> AcceptContactMethods -> (Status ToxProgress -> STM ()) -> IO ()
acceptContact getPolicy AcceptContactMethods{..} writeState = fix $ \loop -> do
join $ atomically $ do
orElse
(getPolicy >>= \case
RefusingToConnect -> do writeState Dormant
return $ return () -- QUIT Dormant/Established
_ -> retry)
(do hs <- getHandshake
handshakeIsSuitable hs >>= \case
True -> do
-- Here we allocate a NetCrypto session for handling CryptoPacket.
writeState (InProgress AwaitingSessionPacket)
transitionToState (InProgress AwaitingSessionPacket)
return loop
False -> return loop)
whileTryingAndNotEstablished :: STM Policy
-> STM (Status t)
-> (Status ToxProgress -> STM ())
-> ((Int -> IO ()) -> STM (IO ()))
-> IO ()
whileTryingAndNotEstablished getPolicy getStatus writeStatus body = fix $ \loop -> do
let retryWhileTrying k = getPolicy >>= \case
TryingToConnect -> retry
_ -> do writeStatus Dormant
return k
ifEstablished t e = getStatus >>= \case
Established -> t
_ -> e
retryAfterTimeout interval = do
timeout interval $ atomically
$ orElse
(retryWhileTrying ())
(ifEstablished (return ()) retry)
loop
join $ atomically $ orElse
(retryWhileTrying (return ())) -- QUIT Dormant/Established
(ifEstablished retry
(body retryAfterTimeout))
data PersueContactMethods params = PersueContactMethods
{ getHandshakeParams :: STM params
, sendHandshake :: params -> IO ()
, retryInterval :: Int
}
-- | Continuously attempt to send handshake packets until a connection is
-- established.
--
-- As long as getPolicy is TryingToConnect and there is no established
-- connection, this function will continue.
persueContact :: STM Policy
-> STM (Status t)
-> PersueContactMethods a
-> (Status ToxProgress -> STM ())
-> IO ()
persueContact getPolicy getStatus PersueContactMethods{..} writeStatus
= whileTryingAndNotEstablished getPolicy getStatus writeStatus
$ \retryAfterTimeout -> do
-- AwaitingDHTKey
-- AcquiringIPAddress
params <- getHandshakeParams
writeStatus (InProgress AcquiringCookie)
return $ do -- AcquiringCookie
-- AwaitingHandshake
-- AwaitingSessionPacket
sendHandshake params
atomically $ writeStatus $ InProgress AwaitingHandshake
retryAfterTimeout retryInterval
data FreshenContactMethods = FreshenContactMethods
{ dhtkeyInterval :: Int
, sockAddrInterval :: Int
, nodeSch :: NodeSearch
, getDHTKey :: STM (Maybe NodeId)
, getSockAddr :: STM (Maybe SockAddr)
, getBuckets :: STM (BucketList NodeInfo)
}
-- send my dht key
-- search for their sockaddr
-- monitor new dht key
-- monitor new sockaddr
--
-- Keep going while TryingToConnect
-- pause while Established
-- Useful:
-- toxidSearch onionTimeout
-- newSearch
-- searchLoop
-- searchCancel
-- -> (r -> STM Bool) -- ^ Invoked on each result. Return False to quit searching.
-- | Continuously search the DHT to obtain ip addresses and to send your dht
-- key to contacts.
--
-- As long as getPolicy is TryingToConnect and there is no established
-- connection, this function will continue.
freshenContact :: STM Policy -> STM (Status t) -> FreshenContactMethods
-> (Status ToxProgress -> STM ())
-> IO ()
freshenContact getPolicy getStatus FreshenContactMethods{..} writeStatus
= whileTryingAndNotEstablished getPolicy getStatus writeStatus
-- retryAfterTimeout :: Int -> IO ()
$ \retryAfterTimeout ->
getDHTKey >>= \case
Nothing -> -- AwaitingDHTKey
retry
Just dk -> getSockAddr >>= \case
Nothing -> do -- AcquiringIPAddress
writeStatus (InProgress AcquiringIPAddress)
return $
do bkts <- atomically $ getBuckets
st <- search nodeSch bkts dk $
\r -> do -- TODO: store saddr, check for finish
return True
atomically $ searchIsFinished st >>= check
-- TODO: searchCancel on stop condition
retryAfterTimeout sockAddrInterval
Just a -> do
writeStatus (InProgress AcquiringCookie)
return $
-- AcquiringCookie
-- AwaitingHandshake
-- AwaitingSessionPacket
do _todo_search_toxid_send_dhtkey -- 123 _todo_search_toxid_send_dhtkey :: IO a0
retryAfterTimeout dhtkeyInterval
|
