{-# LANGUAGE OverloadedStrings #-}
module FuncTorrent.Peer
(Peer(..),
- handlePeerMsgs
+ PieceMap,
+ handlePeerMsgs,
+ bytesDownloaded,
+ initPieceMap,
+ pieceMapFromFile
) where
-import Prelude hiding (lookup, concat, replicate, splitAt, take)
+import Prelude hiding (lookup, concat, replicate, splitAt, take, drop, filter)
-import System.IO (Handle, BufferMode(..), hSetBuffering)
-import Data.ByteString (ByteString, unpack, concat, hGet, hPut, take, empty)
+import System.IO (Handle, BufferMode(..), hSetBuffering, hClose)
+import Data.ByteString (ByteString, unpack, concat, hGet, hPut, take, drop, empty)
import qualified Data.ByteString.Char8 as BC (length)
import Network (connectTo, PortID(..))
import Control.Monad.State
import Data.Bits
import Data.Word (Word8)
-import Data.Map (Map, fromList, toList, (!), mapWithKey, adjust)
-import qualified Crypto.Hash.SHA1 as SHA1 (hash)
+import Data.Map (Map, fromList, toList, (!), mapWithKey, traverseWithKey, adjust, filter)
+import Safe (headMay)
import FuncTorrent.Metainfo (Info(..), Metainfo(..))
-import FuncTorrent.Utils (splitN, splitNum)
-import FuncTorrent.Fileops (createDummyFile, writeFileAtOffset)
+import FuncTorrent.Utils (splitN, splitNum, writeFileAtOffset, readFileAtOffset, verifyHash)
import FuncTorrent.PeerMsgs (Peer(..), PeerMsg(..), sendMsg, getMsg, genHandshakeMsg)
data PState = PState { handle :: Handle
, heChoking :: Bool
, heInterested :: Bool}
-type PeerState = State PState
-
data PieceDlState = Pending
- | InProgress
+ | Downloading
| Have
deriving (Show, Eq)
--- todo - map with index to a new data structure (peers who have that piece amd state)
+-- todo - map with index to a new data structure (peers who have that piece and state)
data PieceData = PieceData { peers :: [Peer] -- ^ list of peers who have this piece
, dlstate :: PieceDlState -- ^ state of the piece from download perspective.
, hash :: ByteString -- ^ piece hash
-- Make the initial Piece map, with the assumption that no peer has the
-- piece and that every piece is pending download.
-mkPieceMap :: Integer -> ByteString -> [Integer] -> PieceMap
-mkPieceMap numPieces pieceHash pLengths = fromList kvs
- where kvs = [(i, PieceData { peers = []
- , dlstate = Pending
- , hash = h
- , len = pLen })
- | (i, h, pLen) <- zip3 [0..numPieces] hashes pLengths]
- hashes = splitN 20 pieceHash
+initPieceMap :: ByteString -> Integer -> Integer -> PieceMap
+initPieceMap pieceHash fileLen pieceLen = fromList kvs
+ where
+ numPieces = (toInteger . (`quot` 20) . BC.length) pieceHash
+ kvs = [(i, PieceData { peers = []
+ , dlstate = Pending
+ , hash = h
+ , len = pLen })
+ | (i, h, pLen) <- zip3 [0..numPieces] hashes pLengths]
+ hashes = splitN 20 pieceHash
+ pLengths = splitNum fileLen pieceLen
+
+pieceMapFromFile :: FilePath -> PieceMap -> IO PieceMap
+pieceMapFromFile filePath pieceMap =
+ traverseWithKey f pieceMap
+ where
+ f k v = do
+ let offset = if k == 0 then 0 else k * len (pieceMap ! (k - 1))
+ isHashValid <- flip verifyHash (hash v) <$> readFileAtOffset filePath offset (len v)
+ if isHashValid
+ then return $ v { dlstate = Have }
+ else return v
havePiece :: PieceMap -> Integer -> Bool
havePiece pm index =
hSetBuffering h LineBuffering
return h
-doHandshake :: Handle -> Peer -> ByteString -> String -> IO ()
-doHandshake h peer infoHash peerid = do
- let hs = genHandshakeMsg infoHash peerid
+doHandshake :: Bool -> Handle -> Peer -> ByteString -> String -> IO ()
+doHandshake True h p infohash peerid = do
+ let hs = genHandshakeMsg infohash peerid
hPut h hs
- putStrLn $ "--> handhake to peer: " ++ show peer
+ putStrLn $ "--> handhake to peer: " ++ show p
_ <- hGet h (length (unpack hs))
- putStrLn $ "<-- handshake from peer: " ++ show peer
+ putStrLn $ "<-- handshake from peer: " ++ show p
return ()
+doHandshake False h p infohash peerid = do
+ let hs = genHandshakeMsg infohash peerid
+ putStrLn "waiting for a handshake"
+ hsMsg <- hGet h (length (unpack hs))
+ putStrLn $ "<-- handshake from peer: " ++ show p
+ let rxInfoHash = take 20 $ drop 28 hsMsg
+ if rxInfoHash /= infohash
+ then do
+ putStrLn "infoHashes does not match"
+ hClose h
+ return ()
+ else do
+ _ <- hPut h hs
+ putStrLn $ "--> handhake to peer: " ++ show p
+ return ()
bitfieldToList :: [Word8] -> [Integer]
bitfieldToList bs = go bs 0
setBits ++ go bs' (pos + 1)
-- helper functions to manipulate PeerState
-toPeerState :: Handle -> Peer -> Bool -> Bool -> Bool -> Bool -> PState
+toPeerState :: Handle
+ -> Peer
+ -> Bool -- ^ meChoking
+ -> Bool -- ^ meInterested
+ -> Bool -- ^ heChoking
+ -> Bool -- ^ heInterested
+ -> PState
toPeerState h p meCh meIn heCh heIn =
PState { handle = h
, peer = p
, meChoking = meCh
, meInterested = meIn }
--- -- recvMsg :: Peer -> Handle -> Msg
--- 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.
pickPiece :: PieceMap -> Maybe Integer
-pickPiece m =
- let pieceList = toList m
- allPending = filter (\(_, v) -> dlstate v == Pending) pieceList
- in
- case allPending of
- [] -> Nothing
- ((i, _):_) -> Just i
+pickPiece =
+ (fst `liftM`) . headMay . toList . filter (\v -> dlstate v == Pending)
+
+bytesDownloaded :: PieceMap -> Integer
+bytesDownloaded =
+ sum . map (len . snd) . toList . filter (\v -> dlstate v == Have)
updatePieceAvailability :: PieceMap -> Peer -> [Integer] -> PieceMap
updatePieceAvailability pieceStatus p pieceList =
then (pd { peers = p : peers pd })
else pd) pieceStatus
-handlePeerMsgs :: Peer -> Metainfo -> String -> IO ()
-handlePeerMsgs p m peerId = do
+handlePeerMsgs :: Peer -> String -> Metainfo -> PieceMap -> Bool -> IO ()
+handlePeerMsgs p peerId m pieceMap isClient = do
h <- connectToPeer p
- doHandshake h p (infoHash m) peerId
- let pstate = toPeerState h p False True False True
- pieceHash = pieces (info m)
- 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)
- createDummyFile fileName (fromIntegral fileLen)
- (r, _) <- runStateT (msgLoop pieceStatus fileName) pstate
+ doHandshake isClient h p (infoHash m) peerId
+ let pstate = toPeerState h p False False True True
+ filePath = name (info m)
+ _ <- runStateT (msgLoop pieceMap filePath) pstate
return ()
msgLoop :: PieceMap -> FilePath -> StateT PState IO ()
-msgLoop pieceStatus file =
- StateT(\pState -> do
- let h = handle pState
- msg <- getMsg h
- liftIO $ putStrLn $ "<-- " ++ show msg ++ "from peer: " ++ show (peer pState)
- case msg of
- KeepAliveMsg -> do
- sendMsg h KeepAliveMsg
- liftIO $ putStrLn $ "--> " ++ "KeepAliveMsg to peer: " ++ show (peer pState)
- runStateT (msgLoop pieceStatus file) pState)
+msgLoop pieceStatus file = do
+ h <- gets handle
+ st <- get
+ case st of
+ PState { meInterested = False, heChoking = True } -> do
+ liftIO $ sendMsg h InterestedMsg
+ gets peer >>= (\p -> liftIO $ putStrLn $ "--> InterestedMsg to peer: " ++ show p)
+ modify (\st' -> st' { meInterested = True })
+ msgLoop pieceStatus file
+ PState { meInterested = True, heChoking = False } ->
+ case pickPiece pieceStatus of
+ Nothing -> liftIO $ putStrLn "Nothing to download"
+ Just workPiece -> do
+ let pLen = len (pieceStatus ! workPiece)
+ liftIO $ putStrLn $ "piece length = " ++ show pLen
+ pBS <- liftIO $ downloadPiece h workPiece pLen
+ if not $ verifyHash pBS (hash (pieceStatus ! workPiece))
+ then
+ liftIO $ putStrLn "Hash mismatch"
+ else do
+ let fileOffset = if workPiece == 0 then 0 else workPiece * len (pieceStatus ! (workPiece - 1))
+ liftIO $ putStrLn $ "Write into file at offset: " ++ show fileOffset
+ liftIO $ writeFileAtOffset file fileOffset pBS
+ msgLoop (adjust (\pieceData -> pieceData { dlstate = Have }) workPiece pieceStatus) file
+ _ -> do
+ msg <- liftIO $ getMsg h
+ gets peer >>= (\p -> liftIO $ putStrLn $ "<-- " ++ show msg ++ "from peer: " ++ show p)
+ case msg of
+ KeepAliveMsg -> do
+ liftIO $ sendMsg h KeepAliveMsg
+ gets peer >>= (\p -> liftIO $ putStrLn $ "--> " ++ "KeepAliveMsg to peer: " ++ show p)
+ msgLoop pieceStatus file
+ BitFieldMsg bss -> do
+ p <- gets peer
+ let pieceList = bitfieldToList (unpack bss)
+ pieceStatus' = updatePieceAvailability pieceStatus p pieceList
+ liftIO $ 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 pieceStatus' file
+ UnChokeMsg -> do
+ modify (\st' -> st' {heChoking = False })
+ msgLoop pieceStatus file
+ ChokeMsg -> do
+ modify (\st' -> st' {heChoking = True })
+ msgLoop pieceStatus file
+ InterestedMsg -> do
+ modify (\st' -> st' {heInterested = True})
+ msgLoop pieceStatus file
+ NotInterestedMsg -> do
+ modify (\st' -> st' {heInterested = False})
+ msgLoop pieceStatus file
+ CancelMsg _ _ _ -> -- check if valid index, begin, length
+ msgLoop pieceStatus file
+ PortMsg _ ->
+ msgLoop pieceStatus file
+ -- handle RequestMsg, HaveMsg. No need to handle PieceMsg here.
+ -- also BitFieldMsg
+
downloadPiece :: Handle -> Integer -> Integer -> IO ByteString
downloadPiece h index pieceLength = do
let chunks = splitNum pieceLength 16384
- 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 pLen
- 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 =
- take 20 (SHA1.hash bs) == pieceHash
+ concat `liftM` 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 pLen
+ 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)
+
projects / functorrent.git / blobdiff