handlePeerMsgs
) where
-import Prelude hiding (lookup, concat, replicate, splitAt, writeFile, take)
+import Prelude hiding (lookup, concat, replicate, splitAt, take)
-import System.IO (Handle, BufferMode(..), IOMode(..), SeekMode(..), withFile, hSeek, hSetBuffering)
-import Data.ByteString (ByteString, pack, unpack, concat, hGet, hPut, singleton, writeFile, take)
-import Data.ByteString.Lazy (fromStrict, fromChunks, toStrict)
-import qualified Data.ByteString.Char8 as BC (replicate, pack, length)
+import System.IO (Handle, BufferMode(..), hSetBuffering)
+import Data.ByteString (ByteString, unpack, concat, hGet, hPut, take, empty)
+import qualified Data.ByteString.Char8 as BC (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, forM)
-import Control.Applicative ((<$>), liftA3)
+import Control.Monad (liftM, forM)
import Data.Bits
import Data.Word (Word8)
import Data.Map (Map, fromList, toList, (!), mapWithKey, adjust)
import FuncTorrent.Metainfo (Info(..), Metainfo(..))
import FuncTorrent.Utils (splitN, splitNum)
-
-type ID = String
-type IP = String
-type Port = Integer
+import FuncTorrent.Fileops (createDummyFile, writeFileAtOffset)
+import FuncTorrent.PeerMsgs (Peer(..), PeerMsg(..), sendMsg, getMsg, genHandshakeMsg)
-- PeerState is a misnomer
data PeerState = PeerState { handle :: Handle
-- 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.
, hash = h
, len = pLen })
| (i, h, pLen) <- zip3 [0..numPieces] hashes pLengths]
- hashes = splitN (fromIntegral numPieces) pieceHash
+ hashes = splitN 20 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@(Peer _ ip port) infoHash peerid = do
- let hs = genHandShakeMsg infoHash peerid
+connectToPeer :: Peer -> IO Handle
+connectToPeer (Peer _ ip port) = do
h <- connectTo ip (PortNumber (fromIntegral port))
hSetBuffering h LineBuffering
+ return h
+
+doHandshake :: Handle -> Peer -> ByteString -> String -> IO ()
+doHandshake h peer infoHash peerid = do
+ let hs = genHandshakeMsg infoHash peerid
hPut h hs
putStrLn $ "--> handhake to peer: " ++ show peer
_ <- hGet h (length (unpack hs))
putStrLn $ "<-- handshake from peer: " ++ show peer
- 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)))
+ return ()
bitfieldToList :: [Word8] -> [Integer]
bitfieldToList bs = go bs 0
in
setBits ++ go bs' (pos + 1)
-createDummyFile :: FilePath -> Int -> IO ()
-createDummyFile path size =
- writeFile path (BC.replicate size '\0')
-
--- write into a file at a specific offet
-writeFileAtOffset :: FilePath -> Integer -> ByteString -> IO ()
-writeFileAtOffset path offset block =
- withFile path WriteMode $ (\h -> do
- _ <- hSeek h AbsoluteSeek offset
- hPut h block)
-
-- recvMsg :: Peer -> Handle -> Msg
-msgLoop :: PeerState -> PieceMap -> IO ()
-msgLoop pState pieceStatus | meInterested pState == False &&
- heChoking pState == True = do
- -- if me NOT Interested and she is Choking, tell her that
- -- I am interested.
- let h = handle pState
- sendMsg h InterestedMsg
- putStrLn $ "--> InterestedMsg to peer: " ++ show (peer pState)
- msgLoop (pState { meInterested = True }) pieceStatus
- | meInterested pState == True &&
- heChoking pState == False =
- -- if me Interested and she not Choking, send her a request
- -- for a piece.
- case pickPiece pieceStatus of
- Nothing -> putStrLn "Nothing to download"
- Just workPiece -> do
- let pLen = len (pieceStatus ! workPiece)
- pBS <- downloadPiece (handle pState) workPiece pLen
- if not $ verifyHash pBS (hash (pieceStatus ! workPiece))
- then
- putStrLn $ "Hash mismatch: " ++ show (hash (pieceStatus ! workPiece)) ++ " vs " ++ show (take 20 (SHA1.hash pBS))
- else
- msgLoop pState (adjust (\pieceData -> pieceData { state = Have }) workPiece pieceStatus)
- | otherwise = do
- msg <- getMsg (handle pState)
- putStrLn $ "<-- " ++ show msg ++ "from peer: " ++ show (peer pState)
- case msg of
- KeepAliveMsg -> do
- sendMsg (handle pState) KeepAliveMsg
- putStrLn $ "--> " ++ "KeepAliveMsg to peer: " ++ show (peer pState)
- msgLoop pState pieceStatus
- BitFieldMsg bss -> do
- let pieceList = bitfieldToList (unpack bss)
- pieceStatus' = updatePieceAvailability pieceStatus (peer pState) pieceList
- 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 pState pieceStatus'
- UnChokeMsg -> do
- msgLoop (pState { heChoking = False }) pieceStatus
- _ -> do
- msgLoop pState pieceStatus
+msgLoop :: PeerState -> PieceMap -> FilePath -> IO ()
+msgLoop pState@(PeerState { meInterested = False, heChoking = True }) pieceStatus file =
+ do
+ -- if me NOT Interested and she is Choking, tell her that
+ -- I am interested.
+ let h = handle pState
+ sendMsg h InterestedMsg
+ putStrLn $ "--> InterestedMsg to peer: " ++ show (peer pState)
+ msgLoop (pState { meInterested = True }) pieceStatus file
+msgLoop pState@(PeerState { meInterested = True, heChoking = False }) pieceStatus file =
+ -- if me Interested and she not Choking, send her a request
+ -- for a piece.
+ case pickPiece pieceStatus of
+ Nothing -> putStrLn "Nothing to download"
+ Just workPiece -> do
+ let pLen = len (pieceStatus ! workPiece)
+ putStrLn $ "piece length = " ++ show pLen
+ pBS <- downloadPiece (handle pState) workPiece pLen
+ if not $ verifyHash pBS (hash (pieceStatus ! workPiece))
+ then
+ putStrLn $ "Hash mismatch: " ++ show (hash (pieceStatus ! workPiece)) ++ " vs " ++ show (take 20 (SHA1.hash pBS))
+ else do
+ let fileOffset = if workPiece == 0 then 0 else workPiece * len (pieceStatus ! (workPiece - 1))
+ putStrLn $ "Write into file at offset: " ++ show fileOffset
+ writeFileAtOffset file fileOffset pBS
+ msgLoop pState (adjust (\pieceData -> pieceData { state = Have }) workPiece pieceStatus) file
+msgLoop pState pieceStatus file = do
+ msg <- getMsg (handle pState)
+ putStrLn $ "<-- " ++ show msg ++ "from peer: " ++ show (peer pState)
+ case msg of
+ KeepAliveMsg -> do
+ sendMsg (handle pState) KeepAliveMsg
+ putStrLn $ "--> " ++ "KeepAliveMsg to peer: " ++ show (peer pState)
+ msgLoop pState pieceStatus file
+ BitFieldMsg bss -> do
+ let pieceList = bitfieldToList (unpack bss)
+ pieceStatus' = updatePieceAvailability pieceStatus (peer pState) pieceList
+ putStrLn $ show (length pieceList) ++ " Pieces"
+ -- 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 pState pieceStatus' file
+ UnChokeMsg ->
+ msgLoop (pState { heChoking = False }) pieceStatus file
+ _ ->
+ msgLoop pState pieceStatus file
-- simple algorithm to pick piece.
-- pick the first piece from 0 that is not downloaded yet.
updatePieceAvailability :: PieceMap -> Peer -> [Integer] -> PieceMap
updatePieceAvailability pieceStatus p pieceList =
mapWithKey (\k pd -> if k `elem` pieceList
- then (pd { peers = p : (peers pd) })
+ then (pd { peers = p : peers pd })
else pd) pieceStatus
handlePeerMsgs :: Peer -> Metainfo -> String -> IO ()
handlePeerMsgs p m peerId = do
- h <- handShake p (infoHash m) peerId
+ h <- connectToPeer p
+ doHandshake h p (infoHash m) peerId
let state = PeerState { handle = h
, peer = p
, heInterested = False
numPieces = (toInteger . (`quot` 20) . BC.length) pieceHash
pLen = pieceLength (info m)
fileLen = lengthInBytes (info m)
+ fileName = name (info m)
pieceStatus = mkPieceMap numPieces pieceHash (splitNum fileLen pLen)
- msgLoop state pieceStatus
+ createDummyFile fileName (fromIntegral fileLen)
+ msgLoop state pieceStatus fileName
downloadPiece :: Handle -> Integer -> Integer -> IO ByteString
downloadPiece h index pieceLength = do
liftM concat $ forM (zip [0..] chunks) (\(i, pLen) -> do
sendMsg h (RequestMsg index (i*pLen) pLen)
putStrLn $ "--> " ++ "RequestMsg for Piece "
- ++ (show index) ++ ", part: " ++ show i ++ " of length: "
+ ++ show index ++ ", part: " ++ show i ++ " of length: "
++ show pLen
- -- TODO: non exhaustive pattern matching. :(
- PieceMsg index begin block <- getMsg h
- putStrLn $ " <-- PieceMsg for Piece: "
- ++ show index
- ++ ", offset: "
- ++ show begin
- return block)
+ msg <- getMsg h
+ case msg of
+ PieceMsg index begin block -> do
+ putStrLn $ " <-- PieceMsg for Piece: "
+ ++ show index
+ ++ ", offset: "
+ ++ show begin
+ return block
+ _ -> do
+ putStrLn "ignoring irrelevant msg"
+ return empty)
verifyHash :: ByteString -> ByteString -> Bool
verifyHash bs pieceHash =
projects / functorrent.git / blobdiff