{-# LANGUAGE OverloadedStrings #-}
module FuncTorrent.Peer
(Peer(..),
- PeerResp(..),
- mkPeerResp,
- handShakeMsg
+ handlePeerMsgs
) where
-import Prelude hiding (lookup, concat, replicate, splitAt)
-import Data.ByteString.Char8 (ByteString, pack, unpack, concat, replicate, splitAt)
-import Data.ByteString.Lazy (toChunks)
-import Data.Int (Int8)
-import Data.List (intercalate)
-import Data.Map as M ((!), lookup)
-import qualified Data.Binary as Bin (encode)
-import qualified Data.ByteString.Base16 as B16 (encode)
-
-import FuncTorrent.Bencode (BVal(..), InfoDict)
-import FuncTorrent.Tracker (infoHash)
-import FuncTorrent.Utils (splitN)
+import Prelude hiding (lookup, concat, replicate, splitAt, empty, writeFile)
+
+import System.IO (Handle, BufferMode(..), hSetBuffering)
+import Data.ByteString (ByteString, pack, unpack, concat, hGet, hPut, singleton, writeFile)
+import Data.ByteString.Lazy (fromStrict, fromChunks, toStrict)
+import qualified Data.ByteString.Char8 as BC (replicate, pack, length)
+import Network (connectTo, PortID(..))
+import Data.Binary (Binary(..), decode, encode)
+import Data.Binary.Put (putWord32be, putWord16be, putWord8)
+import Data.Binary.Get (getWord32be, getWord16be, getWord8, runGet)
+import Control.Monad (replicateM, liftM, forever)
+import Control.Applicative ((<$>), liftA3)
+import Data.Bits
+import Data.Word (Word8)
+import Data.Map (Map(..), fromList, (!))
+import FuncTorrent.Metainfo (Info(..), Metainfo(..))
+import FuncTorrent.Utils (splitN)
-type Address = String
+type ID = String
+type IP = String
type Port = Integer
-data Peer = Peer Address Port
- deriving (Show, Eq)
-
-data PeerResp = PeerResp { interval :: Maybe Integer
- , peers :: [Peer]
- , complete :: Maybe Integer
- , incomplete :: Maybe Integer
- } deriving (Show, Eq)
-
-toInt :: String -> Integer
-toInt = read
-
-mkPeerResp :: BVal -> Either ByteString PeerResp
-mkPeerResp resp =
- case lookup "failure reason" body of
- Just (Bstr err) -> Left err
- Just _ -> Left "Unknown failure"
- Nothing ->
- let (Just (Bint i)) = lookup "interval" body
- (Bstr peersBS) = body ! "peers"
- pl = map (\peer -> let (ip', port') = splitAt 4 peer
- in Peer (toIPNum ip') (toPortNum port'))
- (splitN 6 peersBS)
- in Right PeerResp {
- interval = Just i
- , peers = pl
- , complete = Nothing
- , incomplete = Nothing
- }
- where
- (Bdict body) = resp
- toPortNum = read . ("0x" ++) . unpack . B16.encode
- toIPNum = intercalate "." .
- map (show . toInt . ("0x" ++) . unpack) .
- splitN 2 . B16.encode
-
-
-handShakeMsg :: InfoDict -> String -> ByteString
-handShakeMsg m peer_id = let pstrlen = concat $ toChunks $ Bin.encode (19 :: Int8)
- pstr = pack "BitTorrent protocol"
- reserved = replicate 8 '\0'
- infoH = infoHash m
- peerID = pack peer_id
- in concat [pstrlen, pstr, reserved, infoH, peerID]
+-- PeerState is a misnomer
+data PeerState = PeerState { handle :: Handle
+ , peer :: Peer
+ , meChoking :: Bool
+ , meInterested :: Bool
+ , heChoking :: Bool
+ , heInterested :: Bool}
+
+-- Maintain info on every piece and the current state of it.
+-- should probably be a TVar.
+type Pieces = [PieceData]
+
+data PieceDlState = Pending
+ | InProgress
+ | Have
+ deriving (Show, Eq)
+
+-- todo - map with index to a new data structure (peers who have that piece amd state)
+data PieceData = PieceData { peers :: [Peer] -- ^ list of peers who have this piece
+ , state :: PieceDlState -- ^ state of the piece from download perspective.
+ , hash :: ByteString } -- ^ piece hash
+
+-- which piece is with which peers
+type PieceMap = Map Integer PieceData
+
+-- | Peer is a PeerID, IP address, port tuple
+data Peer = Peer ID IP Port
+ deriving (Show, Eq)
+
+data PeerMsg = KeepAliveMsg
+ | ChokeMsg
+ | UnChokeMsg
+ | InterestedMsg
+ | NotInterestedMsg
+ | HaveMsg Integer
+ | BitFieldMsg ByteString
+ | RequestMsg Integer Integer Integer
+ | PieceMsg Integer Integer ByteString
+ | CancelMsg Integer Integer Integer
+ | PortMsg Port
+ deriving (Show)
+
+-- Make the initial Piece map, with the assumption that no peer has the
+-- piece and that every piece is pending download.
+mkPieceMap :: Integer -> ByteString -> PieceMap
+mkPieceMap numPieces pieceHash = fromList kvs
+ where kvs = [(i, PieceData { peers = []
+ , state = Pending
+ , hash = h }) | (i, h) <- zip [0..numPieces] hashes]
+ hashes = splitN (fromIntegral numPieces) pieceHash
+
+havePiece :: PieceMap -> Integer -> Bool
+havePiece pm index =
+ state (pm ! index) == Have
+
+genHandShakeMsg :: ByteString -> String -> ByteString
+genHandShakeMsg infoHash peer_id = concat [pstrlen, pstr, reserved, infoHash, peerID]
+ where pstrlen = singleton 19
+ pstr = BC.pack "BitTorrent protocol"
+ reserved = BC.replicate 8 '\0'
+ peerID = BC.pack peer_id
+
+handShake :: Peer -> ByteString -> String -> IO Handle
+handShake (Peer _ ip port) infoHash peerid = do
+ let hs = genHandShakeMsg infoHash peerid
+ h <- connectTo ip (PortNumber (fromIntegral port))
+ hSetBuffering h LineBuffering
+ hPut h hs
+ rlenBS <- hGet h (length (unpack hs))
+ putStrLn $ "got handshake from peer: " ++ show rlenBS
+ return h
+
+instance Binary PeerMsg where
+ put msg = case msg of
+ KeepAliveMsg -> putWord32be 0
+ ChokeMsg -> do putWord32be 1
+ putWord8 0
+ UnChokeMsg -> do putWord32be 1
+ putWord8 1
+ InterestedMsg -> do putWord32be 1
+ putWord8 2
+ NotInterestedMsg -> do putWord32be 1
+ putWord8 3
+ HaveMsg i -> do putWord32be 5
+ putWord8 4
+ putWord32be (fromIntegral i)
+ BitFieldMsg bf -> do putWord32be $ fromIntegral (1 + bfListLen)
+ putWord8 5
+ mapM_ putWord8 bfList
+ where bfList = unpack bf
+ bfListLen = length bfList
+ RequestMsg i o l -> do putWord32be 13
+ putWord8 6
+ putWord32be (fromIntegral i)
+ putWord32be (fromIntegral o)
+ putWord32be (fromIntegral l)
+ PieceMsg i o b -> do putWord32be $ fromIntegral (9 + blocklen)
+ putWord8 7
+ putWord32be (fromIntegral i)
+ putWord32be (fromIntegral o)
+ mapM_ putWord8 blockList
+ where blockList = unpack b
+ blocklen = length blockList
+ CancelMsg i o l -> do putWord32be 13
+ putWord8 8
+ putWord32be (fromIntegral i)
+ putWord32be (fromIntegral o)
+ putWord32be (fromIntegral l)
+ PortMsg p -> do putWord32be 3
+ putWord8 9
+ putWord16be (fromIntegral p)
+ get = do
+ l <- getWord32be
+ msgid <- getWord8
+ case msgid of
+ 0 -> return ChokeMsg
+ 1 -> return UnChokeMsg
+ 2 -> return InterestedMsg
+ 3 -> return NotInterestedMsg
+ 4 -> liftM (HaveMsg . fromIntegral) getWord32be
+ 5 -> liftM (BitFieldMsg . pack) (replicateM (fromIntegral l - 1) getWord8)
+ 6 -> liftA3 RequestMsg getInteger getInteger getInteger
+ where getInteger = fromIntegral <$> getWord32be
+ 7 -> liftA3 PieceMsg getInteger getInteger (pack <$> replicateM (fromIntegral l - 9) getWord8)
+ where getInteger = fromIntegral <$> getWord32be
+ 8 -> liftA3 CancelMsg getInteger getInteger getInteger
+ where getInteger = fromIntegral <$> getWord32be
+ 9 -> liftM (PortMsg . fromIntegral) getWord16be
+ _ -> error ("unknown message ID: " ++ show msgid)
+
+getMsg :: Handle -> IO PeerMsg
+getMsg h = do
+ lBS <- hGet h 4
+ let l = bsToInt lBS
+ if l == 0
+ then return KeepAliveMsg
+ else do
+ msg <- hGet h l
+ return $ decode $ fromStrict $ concat [lBS, msg]
+
+sendMsg :: Handle -> PeerMsg -> IO ()
+sendMsg h msg =
+ let bsMsg = toStrict $ encode msg
+ in
+ hPut h bsMsg
+
+bsToInt :: ByteString -> Int
+bsToInt x = fromIntegral (runGet getWord32be (fromChunks (return x)))
+
+bitfieldToList :: [Word8] -> [Integer]
+bitfieldToList bs = go bs 0
+ where go [] _ = []
+ go (b:bs') pos =
+ let setBits = [pos*8 + toInteger i | i <- [0..8], testBit b i]
+ in
+ setBits ++ go bs' (pos + 1)
+
+-- downloadPiece :: Integer -> Handle -> IO ()
+
+createDummyFile :: FilePath -> Int -> IO ()
+createDummyFile path size =
+ writeFile path (BC.replicate size '\0')
+
+-- loop1 :: shake hands with all peers, find out the pieces they have, form PieceData.
+-- recvMsg :: Peer -> Handle -> Msg
+msgLoop :: PeerState -> ByteString -> IO ()
+msgLoop state pieceHash =
+ let numPieces = (toInteger . (`quot` 20) . BC.length) pieceHash
+ pieceStatus = mkPieceMap numPieces pieceHash
+ in
+ forever $ do
+ -- if meInterested and he NOT Choking, pick a piece to download
+ -- and send a requestmsg.
+ msg <- getMsg (handle state)
+ putStrLn $ "got a " ++ show msg
+ case msg of
+ BitFieldMsg bss -> do
+ let pieceList = bitfieldToList (unpack bss)
+ print pieceList
+ -- for each pieceIndex in pieceList, make an entry in the pieceStatus
+ -- map with pieceIndex as the key and modify the value to add the peer.
+
+ -- download each of the piece in order
+ UnChokeMsg -> do
+ print msg
+ msgLoop (state {heChoking = False}) pieceHash
+ _ -> print msg
+
+handlePeerMsgs :: Peer -> Metainfo -> String -> (String -> IO ()) -> IO ()
+handlePeerMsgs p m peerId logFn = do
+ h <- handShake p (infoHash m) peerId
+ logFn "handShake"
+ let state = PeerState { handle = h
+ , peer = p
+ , heInterested = False
+ , heChoking = True
+ , meInterested = True
+ , meChoking = False }
+ msgLoop state (pieces (info m))
+
projects / functorrent.git / blobdiff