{-# LANGUAGE OverloadedStrings #-}
module FuncTorrent.Peer
(Peer(..),
- handShake
+ handlePeerMsgs
) where
-import Prelude hiding (lookup, concat, replicate, splitAt)
+import Prelude hiding (lookup, concat, replicate, splitAt, empty, writeFile)
-import System.IO
-import Data.ByteString (ByteString, unpack, concat, hGet, hPut, singleton)
-import Data.ByteString.Char8 (replicate, pack)
+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(..))
-import Data.Binary.Put (putWord32be, putWord8)
+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 ID = String
type IP = String
type Port = Integer
+-- PeerState is a misnomer
data PeerState = PeerState { handle :: Handle
- , am_choking :: Bool
- , am_interested :: Bool
- , peer_choking :: Bool
- , peer_interested :: Bool }
+ , 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 PieceState = Pending
- | InProgress
- | Have
- deriving (Show)
+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
-data PieceData = PieceData { index :: Int -- ^ Piece number
- , peers :: [Peer] -- ^ list of peers who have this piece
- , state :: PieceState } -- ^ state of the piece from download perspective.
+-- 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
| 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 = pack "BitTorrent protocol"
- reserved = replicate 8 '\0'
- peerID = pack peer_id
+ 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
+handShake peer@(Peer _ ip port) infoHash peerid = do
let hs = genHandShakeMsg infoHash peerid
- handle <- connectTo ip (PortNumber (fromIntegral port))
- hSetBuffering handle LineBuffering
- hPut handle hs
- rlenBS <- hGet handle 1
- let rlen = fromIntegral $ (unpack rlenBS) !! 0
- hGet handle rlen
- return handle
+ h <- connectTo ip (PortNumber (fromIntegral port))
+ hSetBuffering h LineBuffering
+ hPut h hs
+ putStrLn $ "--> handhake to peer: " ++ show peer
+ rlenBS <- hGet h (length (unpack hs))
+ putStrLn $ "<-- handshake from peer: " ++ show peer
+ return h
instance Binary PeerMsg where
put msg = case msg of
putWord8 2
NotInterestedMsg -> do putWord32be 1
putWord8 3
- HaveMsg index -> do putWord32be 5
- putWord8 4
- putWord32be (fromIntegral index)
+ HaveMsg i -> do putWord32be 5
+ putWord8 4
+ putWord32be (fromIntegral i)
BitFieldMsg bf -> do putWord32be $ fromIntegral (1 + bfListLen)
putWord8 5
mapM_ putWord8 bfList
mapM_ putWord8 blockList
where blockList = unpack b
blocklen = length blockList
- CancelMsg i o l -> undefined
- PortMsg p -> undefined
- get = undefined
+ 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 -> PieceMap -> IO ()
+msgLoop state pieceStatus = do
+ -- if meInterested and he NOT Choking, pick a piece to download
+ -- and send a requestmsg.
+ let isMeInterested = meInterested state
+ isHeChoking = heChoking state
+ if (isMeInterested && isHeChoking)
+ then
+ do
+ let h = handle state
+ sendMsg h InterestedMsg
+ putStrLn $ "--> InterestedMsg to peer: " ++ show (peer state)
+ msgLoop state pieceStatus
+ else
+ do
+ msg <- getMsg (handle state)
+ putStrLn $ "<-- " ++ show msg ++ "from peer: " ++ show (peer state)
+ case msg of
+ KeepAliveMsg -> do
+ sendMsg (handle state) KeepAliveMsg
+ msgLoop state pieceStatus
+ 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
+
+ msgLoop state pieceStatus
+ UnChokeMsg -> do
+ msgLoop (state {heChoking = False}) pieceStatus
+ _ -> do
+ msgLoop state pieceStatus
+
+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 = False
+ , meInterested = True
+ , meChoking = False }
+ pieceHash = (pieces (info m))
+ numPieces = (toInteger . (`quot` 20) . BC.length) pieceHash
+ pieceStatus = mkPieceMap numPieces pieceHash
+ msgLoop state pieceStatus
+
projects / functorrent.git / blobdiff