26 files changed, 1193 insertions, 1295 deletions

diff --git a/src/Network/BitTorrent/Address.hs b/src/Network/BitTorrent/Address.hs
new file mode 100644
index 00000000..8723433d
--- /dev/null
+++ b/src/Network/BitTorrent/Address.hs
@@ -0,0 +1,1172 @@
+-- |
+--   Module      :  Network.BitTorrent.Address
+--   Copyright   :  (c) Sam Truzjan 2013
+--                  (c) Daniel Gröber 2013
+--   License     :  BSD3
+--   Maintainer  :  pxqr.sta@gmail.com
+--   Stability   :  provisional
+--   Portability :  portable
+--
+--   Peer and Node addresses.
+--
+{-# LANGUAGE FlexibleInstances          #-}
+{-# LANGUAGE RecordWildCards            #-}
+{-# LANGUAGE StandaloneDeriving         #-}
+{-# LANGUAGE ViewPatterns               #-}
+{-# LANGUAGE GeneralizedNewtypeDeriving #-}
+{-# LANGUAGE MultiParamTypeClasses      #-}
+{-# LANGUAGE DeriveDataTypeable         #-}
+{-# LANGUAGE DeriveFunctor              #-}
+{-# LANGUAGE TemplateHaskell            #-}
+{-# OPTIONS -fno-warn-orphans           #-}
+module Network.BitTorrent.Address
+       ( -- * Address
+         Address (..)
+       , fromAddr
+
+         -- ** IP
+       , IPv4
+       , IPv6
+       , IP (..)
+
+         -- * PeerId
+         -- $peer-id
+       , PeerId
+
+         -- ** Generation
+       , genPeerId
+       , timestamp
+       , entropy
+
+         -- ** Encoding
+       , azureusStyle
+       , shadowStyle
+       , defaultClientId
+       , defaultVersionNumber
+
+         -- * PeerAddr
+         -- $peer-addr
+       , PeerAddr(..)
+       , defaultPorts
+       , peerSockAddr
+       , peerSocket
+
+         -- * Node
+         -- ** Id
+       , NodeId
+       , testIdBit
+       , genNodeId
+       , NodeDistance
+       , distance
+
+         -- ** Info
+       , NodeAddr (..)
+       , NodeInfo (..)
+       , rank
+
+         -- * Fingerprint
+         -- $fingerprint
+       , ClientImpl (..)
+       , Fingerprint (..)
+       , libFingerprint
+       , fingerprint
+
+         -- * Utils
+       , libUserAgent
+       ) where
+
+import Control.Applicative
+import Control.Monad
+import Data.BEncode as BE
+import Data.BEncode   as BS
+import Data.BEncode.BDict (BKey)
+import Data.Bits
+import Data.ByteString as BS
+import Data.ByteString.Internal as BS
+import Data.ByteString.Base16 as Base16
+import Data.ByteString.Char8 as BC
+import Data.ByteString.Char8 as BS8
+import qualified Data.ByteString.Lazy as BL
+import qualified Data.ByteString.Lazy.Builder as BS
+import Data.Char
+import Data.Convertible
+import Data.Default
+import Data.Foldable
+import Data.IP
+import Data.List as L
+import Data.List.Split as L
+import Data.Maybe       (fromMaybe, catMaybes)
+import Data.Monoid
+import Data.Hashable
+import Data.Ord
+import Data.Serialize as S
+import Data.String
+import Data.Time
+import Data.Typeable
+import Data.Version
+import Data.Word
+import qualified Text.ParserCombinators.ReadP as RP
+import Text.Read        (readMaybe)
+import Network.HTTP.Types.QueryLike
+import Network.Socket
+import Text.PrettyPrint as PP hiding ((<>))
+import Text.PrettyPrint.Class
+import System.Locale    (defaultTimeLocale)
+import System.Entropy
+
+-- import Paths_bittorrent (version)
+
+{-----------------------------------------------------------------------
+--  Address
+-----------------------------------------------------------------------}
+
+instance Pretty UTCTime where
+  pretty = PP.text . show
+
+class (Eq a, Serialize a, Typeable a, Hashable a, Pretty a)
+    => Address a where
+  toSockAddr   :: a        -> SockAddr
+  fromSockAddr :: SockAddr -> Maybe a
+
+fromAddr :: (Address a, Address b) => a -> Maybe b
+fromAddr = fromSockAddr . toSockAddr
+
+-- | Note that port is zeroed.
+instance Address IPv4 where
+  toSockAddr = SockAddrInet 0 . toHostAddress
+  fromSockAddr (SockAddrInet _ h) = Just (fromHostAddress h)
+  fromSockAddr  _                 = Nothing
+
+-- | Note that port is zeroed.
+instance Address IPv6 where
+  toSockAddr h = SockAddrInet6 0 0 (toHostAddress6 h) 0
+  fromSockAddr (SockAddrInet6 _ _ h _) = Just (fromHostAddress6 h)
+  fromSockAddr  _                      = Nothing
+
+-- | Note that port is zeroed.
+instance Address IP where
+  toSockAddr (IPv4 h) = toSockAddr h
+  toSockAddr (IPv6 h) = toSockAddr h
+  fromSockAddr sa =
+        IPv4 <$> fromSockAddr sa
+    <|> IPv6 <$> fromSockAddr sa
+
+setPort :: PortNumber -> SockAddr -> SockAddr
+setPort port (SockAddrInet  _   h  ) = SockAddrInet  port   h
+setPort port (SockAddrInet6 _ f h s) = SockAddrInet6 port f h s
+setPort _    (SockAddrUnix  s      ) = SockAddrUnix  s
+{-# INLINE setPort #-}
+
+getPort :: SockAddr -> Maybe PortNumber
+getPort (SockAddrInet  p   _  ) = Just p
+getPort (SockAddrInet6 p _ _ _) = Just p
+getPort (SockAddrUnix  _      ) = Nothing
+{-# INLINE getPort #-}
+
+instance Address a => Address (NodeAddr a) where
+  toSockAddr NodeAddr {..} = setPort nodePort $ toSockAddr nodeHost
+  fromSockAddr sa = NodeAddr <$> fromSockAddr sa <*> getPort sa
+
+instance Address a => Address (PeerAddr a) where
+  toSockAddr PeerAddr {..} = setPort peerPort $ toSockAddr peerHost
+  fromSockAddr sa = PeerAddr Nothing <$> fromSockAddr sa <*> getPort sa
+
+{-----------------------------------------------------------------------
+--  Peer id
+-----------------------------------------------------------------------}
+-- $peer-id
+--
+--  'PeerID' represent self assigned peer identificator. Ideally each
+--  host in the network should have unique peer id to avoid
+--  collisions, therefore for peer ID generation we use good entropy
+--  source. Peer ID is sent in /tracker request/, sent and received in
+--  /peer handshakes/ and used in DHT queries.
+--
+
+-- TODO use unpacked Word160 form (length is known statically)
+
+-- | Peer identifier is exactly 20 bytes long bytestring.
+newtype PeerId = PeerId { getPeerId :: ByteString }
+  deriving (Show, Eq, Ord, BEncode, Typeable)
+
+peerIdLen :: Int
+peerIdLen = 20
+
+-- | For testing purposes only.
+instance Default PeerId where
+  def = azureusStyle defaultClientId defaultVersionNumber ""
+
+instance Hashable PeerId where
+  hashWithSalt = hashUsing getPeerId
+  {-# INLINE hashWithSalt #-}
+
+instance Serialize PeerId where
+  put = putByteString . getPeerId
+  get = PeerId <$> getBytes peerIdLen
+
+instance QueryValueLike PeerId where
+  toQueryValue (PeerId pid) = Just pid
+  {-# INLINE toQueryValue #-}
+
+instance IsString PeerId where
+  fromString str
+      | BS.length bs == peerIdLen = PeerId bs
+      | otherwise = error $ "Peer id should be 20 bytes long: " ++ show str
+    where
+      bs = fromString str
+
+instance Pretty PeerId where
+  pretty = text . BC.unpack . getPeerId
+
+instance Convertible BS.ByteString PeerId where
+  safeConvert bs
+    | BS.length bs == peerIdLen = pure (PeerId bs)
+    |          otherwise        = convError "invalid length" bs
+
+------------------------------------------------------------------------
+
+-- | Pad bytestring so it's becomes exactly request length. Conversion
+-- is done like so:
+--
+--     * length < size: Complete bytestring by given charaters.
+--
+--     * length = size: Output bytestring as is.
+--
+--     * length > size: Drop last (length - size) charaters from a
+--     given bytestring.
+--
+byteStringPadded :: ByteString -- ^ bytestring to be padded.
+                 -> Int        -- ^ size of result builder.
+                 -> Char       -- ^ character used for padding.
+                 -> BS.Builder
+byteStringPadded bs s c =
+      BS.byteString (BS.take s bs) <>
+      BS.byteString (BC.replicate padLen c)
+  where
+    padLen = s - min (BS.length bs) s
+
+-- | Azureus-style encoding have the following layout:
+--
+--     * 1  byte : '-'
+--
+--     * 2  bytes: client id
+--
+--     * 4  bytes: version number
+--
+--     * 1  byte : '-'
+--
+--     * 12 bytes: random number
+--
+azureusStyle :: ByteString -- ^ 2 character client ID, padded with 'H'.
+             -> ByteString -- ^ Version number, padded with 'X'.
+             -> ByteString -- ^ Random number, padded with '0'.
+             -> PeerId     -- ^ Azureus-style encoded peer ID.
+azureusStyle cid ver rnd = PeerId $ BL.toStrict $ BS.toLazyByteString $
+    BS.char8 '-' <>
+      byteStringPadded cid 2  'H' <>
+      byteStringPadded ver 4  'X' <>
+    BS.char8 '-' <>
+      byteStringPadded rnd 12 '0'
+
+-- | Shadow-style encoding have the following layout:
+--
+--     * 1 byte   : client id.
+--
+--     * 0-4 bytes: version number. If less than 4 then padded with
+--     '-' char.
+--
+--     * 15 bytes : random number. If length is less than 15 then
+--     padded with '0' char.
+--
+shadowStyle :: Char       -- ^ Client ID.
+            -> ByteString -- ^ Version number.
+            -> ByteString -- ^ Random number.
+            -> PeerId     -- ^ Shadow style encoded peer ID.
+shadowStyle cid ver rnd = PeerId $ BL.toStrict $ BS.toLazyByteString $
+    BS.char8 cid <>
+      byteStringPadded ver 4  '-' <>
+      byteStringPadded rnd 15 '0'
+
+
+-- | 'HS'- 2 bytes long client identifier.
+defaultClientId :: ByteString
+defaultClientId = "HS"
+
+-- | Gives exactly 4 bytes long version number for any version of the
+-- package.  Version is taken from .cabal file.
+defaultVersionNumber :: ByteString
+defaultVersionNumber = BS.take 4 $ BC.pack $ foldMap show $
+                         versionBranch $ ciVersion libFingerprint
+
+------------------------------------------------------------------------
+
+-- | Gives 15 characters long decimal timestamp such that:
+--
+--     * 6 bytes   : first 6 characters from picoseconds obtained with %q.
+--
+--     * 1 byte    : character \'.\' for readability.
+--
+--     * 9..* bytes: number of whole seconds since the Unix epoch
+--     (!)REVERSED.
+--
+--   Can be used both with shadow and azureus style encoding. This
+--   format is used to make the ID's readable for debugging purposes.
+--
+timestamp :: IO ByteString
+timestamp = (BC.pack . format) <$> getCurrentTime
+  where
+    format t = L.take 6 (formatTime defaultTimeLocale "%q" t) ++ "." ++
+               L.take 9 (L.reverse (formatTime defaultTimeLocale "%s" t))
+
+-- | Gives 15 character long random bytestring. This is more robust
+-- method for generation of random part of peer ID than 'timestamp'.
+entropy :: IO ByteString
+entropy = getEntropy 15
+
+-- NOTE: entropy generates incorrrect peer id
+
+-- |  Here we use 'azureusStyle' encoding with the following args:
+--
+--      * 'HS' for the client id; ('defaultClientId')
+--
+--      * Version of the package for the version number;
+--      ('defaultVersionNumber')
+--
+--      * UTC time day ++ day time for the random number. ('timestamp')
+--
+genPeerId :: IO PeerId
+genPeerId = azureusStyle defaultClientId defaultVersionNumber <$> timestamp
+
+{-----------------------------------------------------------------------
+-- Peer Addr
+-----------------------------------------------------------------------}
+--   $peer-addr
+--
+--   'PeerAddr' is used to represent peer address. Currently it's
+--   just peer IP and peer port but this might change in future.
+--
+
+{-----------------------------------------------------------------------
+--  Port number
+-----------------------------------------------------------------------}
+
+instance BEncode PortNumber where
+  toBEncode   = toBEncode    .  fromEnum
+  fromBEncode = fromBEncode >=> portNumber
+    where
+      portNumber :: Integer -> BS.Result PortNumber
+      portNumber n
+        | 0 <= n && n <= fromIntegral (maxBound :: Word16)
+        = pure $ fromIntegral n
+        | otherwise = decodingError $ "PortNumber: " ++ show n
+
+instance Serialize PortNumber where
+  get = fromIntegral <$> getWord16be
+  {-# INLINE get #-}
+  put = putWord16be . fromIntegral
+  {-# INLINE put #-}
+
+instance Hashable PortNumber where
+  hashWithSalt s = hashWithSalt s . fromEnum
+  {-# INLINE hashWithSalt #-}
+
+instance Pretty PortNumber where
+  pretty = PP.int . fromEnum
+  {-# INLINE pretty #-}
+
+{-----------------------------------------------------------------------
+--  IP addr
+-----------------------------------------------------------------------}
+
+class IPAddress i where
+  toHostAddr :: i -> Either HostAddress HostAddress6
+
+instance IPAddress IPv4 where
+  toHostAddr = Left . toHostAddress
+  {-# INLINE toHostAddr #-}
+
+instance IPAddress IPv6 where
+  toHostAddr = Right . toHostAddress6
+  {-# INLINE toHostAddr #-}
+
+instance IPAddress IP where
+  toHostAddr (IPv4 ip) = toHostAddr ip
+  toHostAddr (IPv6 ip) = toHostAddr ip
+  {-# INLINE toHostAddr #-}
+
+deriving instance Typeable IP
+deriving instance Typeable IPv4
+deriving instance Typeable IPv6
+
+ipToBEncode :: Show i => i -> BValue
+ipToBEncode ip = BString $ BS8.pack $ show ip
+{-# INLINE ipToBEncode #-}
+
+ipFromBEncode :: Read a => BValue -> BS.Result a
+ipFromBEncode (BString (BS8.unpack -> ipStr))
+  | Just ip <- readMaybe (ipStr) = pure ip
+  |         otherwise            = decodingError $ "IP: " ++ ipStr
+ipFromBEncode _    = decodingError $ "IP: addr should be a bstring"
+
+instance BEncode IP where
+  toBEncode   = ipToBEncode
+  {-# INLINE toBEncode #-}
+  fromBEncode = ipFromBEncode
+  {-# INLINE fromBEncode #-}
+
+instance BEncode IPv4 where
+  toBEncode   = ipToBEncode
+  {-# INLINE toBEncode #-}
+  fromBEncode = ipFromBEncode
+  {-# INLINE fromBEncode #-}
+
+instance BEncode IPv6 where
+  toBEncode   = ipToBEncode
+  {-# INLINE toBEncode #-}
+  fromBEncode = ipFromBEncode
+  {-# INLINE fromBEncode #-}
+
+-- | When 'get'ing an IP it must be 'isolate'd to the appropriate
+-- number of bytes since we have no other way of telling which
+-- address type we are trying to parse
+instance Serialize IP where
+    put (IPv4 ip) = put ip
+    put (IPv6 ip) = put ip
+
+    get = do
+      n <- remaining
+      case n of
+        4  -> IPv4 <$> get
+        16 -> IPv6 <$> get
+        _ -> fail "Wrong number of bytes remaining to parse IP"
+
+instance Serialize IPv4 where
+    put = putWord32host    .  toHostAddress
+    get = fromHostAddress <$> getWord32host
+
+instance Serialize IPv6 where
+    put ip = put $ toHostAddress6 ip
+    get = fromHostAddress6 <$> get
+
+instance Pretty IPv4 where
+  pretty = PP.text . show
+  {-# INLINE pretty #-}
+
+instance Pretty IPv6 where
+  pretty = PP.text . show
+  {-# INLINE pretty #-}
+
+instance Pretty IP where
+  pretty = PP.text . show
+  {-# INLINE pretty #-}
+
+instance Hashable IPv4 where
+  hashWithSalt = hashUsing toHostAddress
+  {-# INLINE hashWithSalt #-}
+
+instance Hashable IPv6 where
+  hashWithSalt s a = hashWithSalt s (toHostAddress6 a)
+
+instance Hashable IP where
+  hashWithSalt s (IPv4 h) = hashWithSalt s h
+  hashWithSalt s (IPv6 h) = hashWithSalt s h
+
+{-----------------------------------------------------------------------
+--  Peer addr
+-----------------------------------------------------------------------}
+-- TODO check semantic of ord and eq instances
+
+-- | Peer address info normally extracted from peer list or peer
+-- compact list encoding.
+data PeerAddr a = PeerAddr
+  { peerId   :: !(Maybe PeerId)
+
+    -- | This is usually 'IPv4', 'IPv6', 'IP' or unresolved
+    -- 'HostName'.
+  , peerHost :: !a
+
+    -- | The port the peer listenning for incoming P2P sessions.
+  , peerPort :: {-# UNPACK #-} !PortNumber
+  } deriving (Show, Eq, Ord, Typeable, Functor)
+
+peer_ip_key, peer_id_key, peer_port_key :: BKey
+peer_ip_key   = "ip"
+peer_id_key   = "peer id"
+peer_port_key = "port"
+
+-- | The tracker's 'announce response' compatible encoding.
+instance (Typeable a, BEncode a) => BEncode (PeerAddr a) where
+  toBEncode PeerAddr {..} = toDict $
+       peer_ip_key   .=! peerHost
+    .: peer_id_key   .=? peerId
+    .: peer_port_key .=! peerPort
+    .: endDict
+
+  fromBEncode = fromDict $ do
+    peerAddr <$>! peer_ip_key
+             <*>? peer_id_key
+             <*>! peer_port_key
+    where
+      peerAddr = flip PeerAddr
+
+-- | The tracker's 'compact peer list' compatible encoding. The
+-- 'peerId' is always 'Nothing'.
+--
+--   For more info see: <http://www.bittorrent.org/beps/bep_0023.html>
+--
+-- TODO: test byte order
+instance (Serialize a) => Serialize (PeerAddr a) where
+  put PeerAddr {..} = put peerHost >> put peerPort
+  get = PeerAddr Nothing <$> get <*> get
+
+-- | @127.0.0.1:6881@
+instance Default (PeerAddr IPv4) where
+  def = "127.0.0.1:6881"
+
+-- | @127.0.0.1:6881@
+instance Default (PeerAddr IP) where
+  def = IPv4 <$> def
+
+-- | Example:
+--
+--   @peerPort \"127.0.0.1:6881\" == 6881@
+--
+instance IsString (PeerAddr IPv4) where
+  fromString str
+    | [hostAddrStr, portStr] <- splitWhen (== ':') str
+    , Just hostAddr <- readMaybe hostAddrStr
+    , Just portNum  <- toEnum <$> readMaybe portStr
+                = PeerAddr Nothing hostAddr portNum
+    | otherwise = error $ "fromString: unable to parse (PeerAddr IPv4): " ++ str
+
+instance Read (PeerAddr IPv4) where
+  readsPrec i = RP.readP_to_S $ do
+    ipv4 <- RP.readS_to_P (readsPrec i)
+    _    <- RP.char ':'
+    port <- toEnum <$> RP.readS_to_P (readsPrec i)
+    return $ PeerAddr Nothing ipv4 port
+
+readsIPv6_port :: String -> [((IPv6, PortNumber), String)]
+readsIPv6_port = RP.readP_to_S $ do
+  ip <- RP.char '[' *> (RP.readS_to_P reads) <* RP.char ']'
+  _ <- RP.char ':'
+  port <- toEnum <$> read <$> (RP.many1 $ RP.satisfy isDigit) <* RP.eof
+  return (ip,port)
+
+instance IsString (PeerAddr IPv6) where
+  fromString str
+    | [((ip,port),"")] <- readsIPv6_port str =
+        PeerAddr Nothing ip port
+    | otherwise = error $ "fromString: unable to parse (PeerAddr IPv6): " ++ str
+
+instance IsString (PeerAddr IP) where
+  fromString str
+    | '[' `L.elem` str = IPv6 <$> fromString str
+    |      otherwise   = IPv4 <$> fromString str
+
+-- | fingerprint + "at" + dotted.host.inet.addr:port
+-- TODO: instances for IPv6, HostName
+instance Pretty a => Pretty (PeerAddr a) where
+  pretty PeerAddr {..}
+    | Just pid <- peerId = pretty (fingerprint pid) <+> "at" <+> paddr
+    |     otherwise      = paddr
+    where
+      paddr = pretty peerHost <> ":" <> text (show peerPort)
+
+instance Hashable a => Hashable (PeerAddr a) where
+  hashWithSalt s PeerAddr {..} =
+    s `hashWithSalt` peerId `hashWithSalt` peerHost `hashWithSalt` peerPort
+
+-- | Ports typically reserved for bittorrent P2P listener.
+defaultPorts :: [PortNumber]
+defaultPorts =  [6881..6889]
+
+_resolvePeerAddr :: (IPAddress i) => PeerAddr HostName -> PeerAddr i
+_resolvePeerAddr = undefined
+
+_peerSockAddr :: PeerAddr IP -> (Family, SockAddr)
+_peerSockAddr PeerAddr {..} =
+    case peerHost of
+          IPv4 ipv4 ->
+              (AF_INET, SockAddrInet peerPort (toHostAddress  ipv4))
+          IPv6 ipv6 ->
+              (AF_INET6, SockAddrInet6 peerPort 0 (toHostAddress6 ipv6) 0)
+
+peerSockAddr :: PeerAddr IP -> SockAddr
+peerSockAddr = snd . _peerSockAddr
+
+-- | Create a socket connected to the address specified in a peerAddr
+peerSocket :: SocketType -> PeerAddr IP -> IO Socket
+peerSocket socketType pa = do
+    let (family, addr) = _peerSockAddr pa
+    sock <- socket family socketType defaultProtocol
+    connect sock addr
+    return sock
+
+{-----------------------------------------------------------------------
+--  Node info
+-----------------------------------------------------------------------}
+--   $node-info
+--
+--   A \"node\" is a client\/server listening on a UDP port
+--   implementing the distributed hash table protocol. The DHT is
+--   composed of nodes and stores the location of peers. BitTorrent
+--   clients include a DHT node, which is used to contact other nodes
+--   in the DHT to get the location of peers to download from using
+--   the BitTorrent protocol.
+
+-- TODO more compact representation ('ShortByteString's?)
+
+-- | Each node has a globally unique identifier known as the \"node
+-- ID.\"
+--
+--   Normally, /this/ node id should be saved between invocations
+--   of the client software.
+newtype NodeId = NodeId ByteString
+  deriving (Show, Eq, Ord, BEncode, Typeable)
+
+nodeIdSize :: Int
+nodeIdSize = 20
+
+-- | Meaningless node id, for testing purposes only.
+instance Default NodeId where
+  def = NodeId (BS.replicate nodeIdSize 0)
+
+instance Serialize NodeId where
+  get = NodeId <$> getByteString nodeIdSize
+  {-# INLINE get #-}
+  put (NodeId bs) = putByteString bs
+  {-# INLINE put #-}
+
+-- | ASCII encoded.
+instance IsString NodeId where
+  fromString str
+    | L.length str == nodeIdSize = NodeId (fromString str)
+    |           otherwise = error "fromString: invalid NodeId length"
+  {-# INLINE fromString #-}
+
+-- | base16 encoded.
+instance Pretty NodeId where
+  pretty (NodeId nid) = PP.text $ BC.unpack $ Base16.encode nid
+
+-- | Test if the nth bit is set.
+testIdBit :: NodeId -> Word -> Bool
+testIdBit (NodeId bs) i
+  | fromIntegral i < nodeIdSize * 8
+  , (q, r) <- quotRem (fromIntegral i) 8
+  = testBit (BS.index bs q) r
+  |     otherwise      = False
+{-# INLINE testIdBit #-}
+
+-- TODO WARN is the 'system' random suitable for this?
+-- | Generate random NodeID used for the entire session.
+--   Distribution of ID's should be as uniform as possible.
+--
+genNodeId :: IO NodeId
+genNodeId = NodeId <$> getEntropy nodeIdSize
+
+------------------------------------------------------------------------
+
+-- | In Kademlia, the distance metric is XOR and the result is
+-- interpreted as an unsigned integer.
+newtype NodeDistance = NodeDistance BS.ByteString
+  deriving (Eq, Ord)
+
+instance Pretty NodeDistance where
+  pretty (NodeDistance bs) = foldMap bitseq $ BS.unpack bs
+    where
+      listBits w = L.map (testBit w) (L.reverse [0..bitSize w - 1])
+      bitseq = foldMap (int . fromEnum) . listBits
+
+-- | distance(A,B) = |A xor B| Smaller values are closer.
+distance :: NodeId -> NodeId -> NodeDistance
+distance (NodeId a) (NodeId b) = NodeDistance (BS.pack (BS.zipWith xor a b))
+
+------------------------------------------------------------------------
+
+data NodeAddr a = NodeAddr
+  { nodeHost ::                !a
+  , nodePort :: {-# UNPACK #-} !PortNumber
+  } deriving (Eq, Typeable, Functor)
+
+instance Show a => Show (NodeAddr a) where
+  showsPrec i NodeAddr {..}
+    = showsPrec i nodeHost <> showString ":" <> showsPrec i nodePort
+
+instance Read (NodeAddr IPv4) where
+  readsPrec i x = [ (fromPeerAddr a, s) | (a, s) <- readsPrec i x ]
+
+-- | @127.0.0.1:6882@
+instance Default (NodeAddr IPv4) where
+  def = "127.0.0.1:6882"
+
+-- | KRPC compatible encoding.
+instance Serialize a => Serialize (NodeAddr a) where
+  get = NodeAddr <$> get <*> get
+  {-# INLINE get #-}
+  put NodeAddr {..} = put nodeHost >> put nodePort
+  {-# INLINE put #-}
+
+-- | Torrent file compatible encoding.
+instance BEncode a => BEncode (NodeAddr a) where
+  toBEncode NodeAddr {..} = toBEncode (nodeHost, nodePort)
+  {-# INLINE toBEncode #-}
+  fromBEncode b = uncurry NodeAddr <$> fromBEncode b
+  {-# INLINE fromBEncode #-}
+
+instance Hashable a => Hashable (NodeAddr a) where
+  hashWithSalt s NodeAddr {..} = hashWithSalt s (nodeHost, nodePort)
+  {-# INLINE hashWithSalt #-}
+
+instance Pretty ip => Pretty (NodeAddr ip) where
+  pretty NodeAddr {..} = pretty nodeHost <> ":" <> pretty nodePort
+
+-- | Example:
+--
+--   @nodePort \"127.0.0.1:6881\" == 6881@
+--
+instance IsString (NodeAddr IPv4) where
+  fromString = fromPeerAddr . fromString
+
+fromPeerAddr :: PeerAddr a -> NodeAddr a
+fromPeerAddr PeerAddr {..} = NodeAddr
+  { nodeHost = peerHost
+  , nodePort = peerPort
+  }
+
+------------------------------------------------------------------------
+
+data NodeInfo a = NodeInfo
+  { nodeId   :: !NodeId
+  , nodeAddr :: !(NodeAddr a)
+  } deriving (Show, Eq, Functor)
+
+instance Eq a => Ord (NodeInfo a) where
+  compare = comparing nodeId
+
+-- | KRPC 'compact list' compatible encoding: contact information for
+-- nodes is encoded as a 26-byte string. Also known as "Compact node
+-- info" the 20-byte Node ID in network byte order has the compact
+-- IP-address/port info concatenated to the end.
+instance Serialize a => Serialize (NodeInfo a) where
+  get = NodeInfo <$> get <*> get
+  put NodeInfo {..} = put nodeId >> put nodeAddr
+
+instance Pretty ip => Pretty (NodeInfo ip) where
+  pretty NodeInfo {..} = pretty nodeId <> "@(" <> pretty nodeAddr <> ")"
+
+instance Pretty ip => Pretty [NodeInfo ip] where
+  pretty = PP.vcat . PP.punctuate "," . L.map pretty
+
+-- | Order by closeness: nearest nodes first.
+rank :: Eq ip => NodeId -> [NodeInfo ip] -> [NodeInfo ip]
+rank nid = L.sortBy (comparing (distance nid . nodeId))
+
+{-----------------------------------------------------------------------
+-- Fingerprint
+-----------------------------------------------------------------------}
+--   $fingerprint
+--
+--   'Fingerprint' is used to identify the client implementation and
+--   version which also contained in 'Peer'. For exsample first 6
+--   bytes of peer id of this this library are @-HS0100-@ while for
+--   mainline we have @M4-3-6--@.  We could extract this info and
+--   print in human-friendly form: this is useful for debugging and
+--   logging.
+--
+--   For more information see:
+--   <http://bittorrent.org/beps/bep_0020.html>
+--
+--
+--   NOTE: Do /not/ use this information to control client
+--   capabilities (such as supported enchancements), this should be
+--   done using 'Network.BitTorrent.Extension'!
+--
+
+-- TODO FIXME
+version :: Version
+version = Version [0, 0, 0, 3] []
+
+-- | List of registered client versions + 'IlibHSbittorrent' (this
+-- package) + 'IUnknown' (for not recognized software). All names are
+-- prefixed by \"I\" because some of them starts from lowercase letter
+-- but that is not a valid Haskell constructor name.
+--
+data ClientImpl =
+   IUnknown
+
+ | IMainline
+
+ | IABC
+ | IOspreyPermaseed
+ | IBTQueue
+ | ITribler
+ | IShadow
+ | IBitTornado
+
+-- UPnP(!) Bit Torrent !???
+-- 'U' - UPnP NAT Bit Torrent
+ | IBitLord
+ | IOpera
+ | IMLdonkey
+
+ | IAres
+ | IArctic
+ | IAvicora
+ | IBitPump
+ | IAzureus
+ | IBitBuddy
+ | IBitComet
+ | IBitflu
+ | IBTG
+ | IBitRocket
+ | IBTSlave
+ | IBittorrentX
+ | IEnhancedCTorrent
+ | ICTorrent
+ | IDelugeTorrent
+ | IPropagateDataClient
+ | IEBit
+ | IElectricSheep
+ | IFoxTorrent
+ | IGSTorrent
+ | IHalite
+ | IlibHSbittorrent
+ | IHydranode
+ | IKGet
+ | IKTorrent
+ | ILH_ABC
+ | ILphant
+ | ILibtorrent
+ | ILibTorrent
+ | ILimeWire
+ | IMonoTorrent
+ | IMooPolice
+ | IMiro
+ | IMoonlightTorrent
+ | INetTransport
+ | IPando
+ | IqBittorrent
+ | IQQDownload
+ | IQt4TorrentExample
+ | IRetriever
+ | IShareaza
+ | ISwiftbit
+ | ISwarmScope
+ | ISymTorrent
+ | Isharktorrent
+ | ITorrentDotNET
+ | ITransmission
+ | ITorrentstorm
+ | ITuoTu
+ | IuLeecher
+ | IuTorrent
+ | IVagaa
+ | IBitLet
+ | IFireTorrent
+ | IXunlei
+ | IXanTorrent
+ | IXtorrent
+ | IZipTorrent
+   deriving (Show, Eq, Ord, Enum, Bounded)
+
+parseImpl :: ByteString -> ClientImpl
+parseImpl = f . BC.unpack
+ where
+  f "AG" = IAres
+  f "A~" = IAres
+  f "AR" = IArctic
+  f "AV" = IAvicora
+  f "AX" = IBitPump
+  f "AZ" = IAzureus
+  f "BB" = IBitBuddy
+  f "BC" = IBitComet
+  f "BF" = IBitflu
+  f "BG" = IBTG
+  f "BR" = IBitRocket
+  f "BS" = IBTSlave
+  f "BX" = IBittorrentX
+  f "CD" = IEnhancedCTorrent
+  f "CT" = ICTorrent
+  f "DE" = IDelugeTorrent
+  f "DP" = IPropagateDataClient
+  f "EB" = IEBit
+  f "ES" = IElectricSheep
+  f "FT" = IFoxTorrent
+  f "GS" = IGSTorrent
+  f "HL" = IHalite
+  f "HS" = IlibHSbittorrent
+  f "HN" = IHydranode
+  f "KG" = IKGet
+  f "KT" = IKTorrent
+  f "LH" = ILH_ABC
+  f "LP" = ILphant
+  f "LT" = ILibtorrent
+  f "lt" = ILibTorrent
+  f "LW" = ILimeWire
+  f "MO" = IMonoTorrent
+  f "MP" = IMooPolice
+  f "MR" = IMiro
+  f "ML" = IMLdonkey
+  f "MT" = IMoonlightTorrent
+  f "NX" = INetTransport
+  f "PD" = IPando
+  f "qB" = IqBittorrent
+  f "QD" = IQQDownload
+  f "QT" = IQt4TorrentExample
+  f "RT" = IRetriever
+  f "S~" = IShareaza
+  f "SB" = ISwiftbit
+  f "SS" = ISwarmScope
+  f "ST" = ISymTorrent
+  f "st" = Isharktorrent
+  f "SZ" = IShareaza
+  f "TN" = ITorrentDotNET
+  f "TR" = ITransmission
+  f "TS" = ITorrentstorm
+  f "TT" = ITuoTu
+  f "UL" = IuLeecher
+  f "UT" = IuTorrent
+  f "VG" = IVagaa
+  f "WT" = IBitLet
+  f "WY" = IFireTorrent
+  f "XL" = IXunlei
+  f "XT" = IXanTorrent
+  f "XX" = IXtorrent
+  f "ZT" = IZipTorrent
+  f _    = IUnknown
+
+-- | Used to represent a not recognized implementation
+instance Default ClientImpl where
+  def = IUnknown
+  {-# INLINE def #-}
+
+-- | Example: @\"BitLet\" == 'IBitLet'@
+instance IsString ClientImpl where
+  fromString str
+    | Just impl <- L.lookup str alist = impl
+    | otherwise = error $ "fromString: not recognized " ++ str
+    where
+      alist = L.map mk [minBound..maxBound]
+      mk  x = (L.tail $ show x, x)
+
+-- | Example: @pretty 'IBitLet' == \"IBitLet\"@
+instance Pretty ClientImpl where
+  pretty = text . L.tail . show
+
+-- | Just the '0' version.
+instance Default Version where
+  def = Version [0] []
+  {-# INLINE def #-}
+
+-- | For dot delimited version strings.
+--   Example: @fromString \"0.1.0.2\" == Version [0, 1, 0, 2]@
+--
+instance IsString Version where
+  fromString str
+    | Just nums <- chunkNums str = Version nums []
+    | otherwise = error $ "fromString: invalid version string " ++ str
+    where
+      chunkNums = sequence . L.map readMaybe . L.linesBy ('.' ==)
+
+instance Pretty Version where
+  pretty = text . showVersion
+
+-- | The all sensible infomation that can be obtained from a peer
+-- identifier or torrent /createdBy/ field.
+data Fingerprint = Fingerprint
+  { ciImpl    :: ClientImpl
+  , ciVersion :: Version
+  } deriving (Show, Eq, Ord)
+
+-- | Unrecognized client implementation.
+instance Default Fingerprint where
+  def = Fingerprint def def
+  {-# INLINE def #-}
+
+-- | Example: @\"BitComet-1.2\" == ClientInfo IBitComet (Version [1, 2] [])@
+instance IsString Fingerprint where
+  fromString str
+    | _ : ver <- _ver = Fingerprint (fromString impl) (fromString ver)
+    | otherwise = error $ "fromString: invalid client info string" ++ str
+    where
+      (impl, _ver) = L.span ((/=) '-') str
+
+instance Pretty Fingerprint where
+  pretty Fingerprint {..} = pretty ciImpl <+> "version" <+> pretty ciVersion
+
+-- | Fingerprint of this (the bittorrent library) package. Normally,
+-- applications should introduce its own fingerprints, otherwise they
+-- can use 'libFingerprint' value.
+--
+libFingerprint :: Fingerprint
+libFingerprint =  Fingerprint IlibHSbittorrent version
+
+-- | HTTP user agent of this (the bittorrent library) package. Can be
+-- used in HTTP tracker requests.
+libUserAgent :: String
+libUserAgent = render (pretty IlibHSbittorrent <> "/" <> pretty version)
+
+{-----------------------------------------------------------------------
+--  For torrent file
+-----------------------------------------------------------------------}
+-- TODO collect information about createdBy torrent field
+{-
+renderImpl :: ClientImpl -> Text
+renderImpl = T.pack . L.tail . show
+
+renderVersion :: Version -> Text
+renderVersion = undefined
+
+renderClientInfo :: ClientInfo -> Text
+renderClientInfo ClientInfo {..} = renderImpl ciImpl <> "/" <> renderVersion ciVersion
+
+parseClientInfo :: Text -> ClientImpl
+parseClientInfo t = undefined
+-}
+{-
+-- code used for generation; remove it later on
+
+mkEnumTyDef :: NM -> String
+mkEnumTyDef = unlines . map (" | I" ++) . nub . map snd
+
+mkPars :: NM -> String
+mkPars = unlines . map (\(code, impl) -> "  f \"" ++ code ++ "\" = " ++ "I" ++ impl)
+
+type NM = [(String, String)]
+nameMap :: NM
+nameMap =
+ [ ("AG", "Ares")
+ , ("A~", "Ares")
+ , ("AR", "Arctic")
+ , ("AV", "Avicora")
+ , ("AX", "BitPump")
+ , ("AZ", "Azureus")
+ , ("BB", "BitBuddy")
+ , ("BC", "BitComet")
+ , ("BF", "Bitflu")
+ , ("BG", "BTG")
+ , ("BR", "BitRocket")
+ , ("BS", "BTSlave")
+ , ("BX", "BittorrentX")
+ , ("CD", "EnhancedCTorrent")
+ , ("CT", "CTorrent")
+ , ("DE", "DelugeTorrent")
+ , ("DP", "PropagateDataClient")
+ , ("EB", "EBit")
+ , ("ES", "ElectricSheep")
+ , ("FT", "FoxTorrent")
+ , ("GS", "GSTorrent")
+ , ("HL", "Halite")
+ , ("HS", "libHSnetwork_bittorrent")
+ , ("HN", "Hydranode")
+ , ("KG", "KGet")
+ , ("KT", "KTorrent")
+ , ("LH", "LH_ABC")
+ , ("LP", "Lphant")
+ , ("LT", "Libtorrent")
+ , ("lt", "LibTorrent")
+ , ("LW", "LimeWire")
+ , ("MO", "MonoTorrent")
+ , ("MP", "MooPolice")
+ , ("MR", "Miro")
+ , ("MT", "MoonlightTorrent")
+ , ("NX", "NetTransport")
+ , ("PD", "Pando")
+ , ("qB", "qBittorrent")
+ , ("QD", "QQDownload")
+ , ("QT", "Qt4TorrentExample")
+ , ("RT", "Retriever")
+ , ("S~", "Shareaza")
+ , ("SB", "Swiftbit")
+ , ("SS", "SwarmScope")
+ , ("ST", "SymTorrent")
+ , ("st", "sharktorrent")
+ , ("SZ", "Shareaza")
+ , ("TN", "TorrentDotNET")
+ , ("TR", "Transmission")
+ , ("TS", "Torrentstorm")
+ , ("TT", "TuoTu")
+ , ("UL", "uLeecher")
+ , ("UT", "uTorrent")
+ , ("VG", "Vagaa")
+ , ("WT", "BitLet")
+ , ("WY", "FireTorrent")
+ , ("XL", "Xunlei")
+ , ("XT", "XanTorrent")
+ , ("XX", "Xtorrent")
+ , ("ZT", "ZipTorrent")
+ ]
+-}
+
+-- TODO use regexps
+
+-- | Tries to extract meaningful information from peer ID bytes. If
+-- peer id uses unknown coding style then client info returned is
+-- 'def'.
+--
+fingerprint :: PeerId -> Fingerprint
+fingerprint pid = either (const def) id $ runGet getCI (getPeerId pid)
+  where
+    getCI    = do
+      leading <- BS.w2c <$> getWord8
+      case leading of
+        '-' -> Fingerprint <$> getAzureusImpl <*> getAzureusVersion
+        'M' -> Fingerprint <$> pure IMainline <*> getMainlineVersion
+        'e' -> Fingerprint <$> getBitCometImpl <*> getBitCometVersion
+        'F' -> Fingerprint <$> getBitCometImpl <*> getBitCometVersion
+        c   -> do
+          c1 <- w2c <$> S.lookAhead getWord8
+          if c1 == 'P'
+            then do
+                 _ <- getWord8
+                 Fingerprint <$> pure IOpera            <*> getOperaVersion
+            else Fingerprint <$> pure (getShadowImpl c) <*> getShadowVersion
+
+    getMainlineVersion = do
+      str <- BC.unpack <$> getByteString 7
+      let mnums = L.filter (not . L.null) $ L.linesBy ('-' ==) str
+      return $ Version (fromMaybe [] $ sequence $ L.map readMaybe mnums) []
+
+    getAzureusImpl    = parseImpl <$> getByteString 2
+    getAzureusVersion = mkVer     <$> getByteString 4
+      where
+        mkVer bs = Version [fromMaybe 0 $ readMaybe $ BC.unpack bs] []
+
+    getBitCometImpl = do
+      bs <- getByteString 3
+      S.lookAhead $ do
+        _  <- getByteString 2
+        lr <- getByteString 4
+        return $
+          if lr == "LORD" then IBitLord  else
+          if bs == "UTB"  then IBitComet else
+          if bs == "xbc"  then IBitComet else def
+
+    getBitCometVersion = do
+      x <- getWord8
+      y <- getWord8
+      return $ Version [fromIntegral x, fromIntegral y] []
+
+    getOperaVersion = do
+      str <- BC.unpack <$> getByteString 4
+      return $ Version [fromMaybe 0 $ readMaybe str] []
+
+    getShadowImpl 'A' = IABC
+    getShadowImpl 'O' = IOspreyPermaseed
+    getShadowImpl 'Q' = IBTQueue
+    getShadowImpl 'R' = ITribler
+    getShadowImpl 'S' = IShadow
+    getShadowImpl 'T' = IBitTornado
+    getShadowImpl  _  = IUnknown
+
+    decodeShadowVerNr :: Char -> Maybe Int
+    decodeShadowVerNr c
+      | '0' < c && c <= '9' = Just  (fromEnum c - fromEnum '0')
+      | 'A' < c && c <= 'Z' = Just ((fromEnum c - fromEnum 'A') + 10)
+      | 'a' < c && c <= 'z' = Just ((fromEnum c - fromEnum 'a') + 36)
+      |        otherwise    = Nothing
+
+    getShadowVersion = do
+      str <- BC.unpack <$> getByteString 5
+      return $ Version (catMaybes $ L.map decodeShadowVerNr str) []
diff --git a/src/Network/BitTorrent/Client.hs b/src/Network/BitTorrent/Client.hs
index 700289d2..d21b4d1e 100644
--- a/src/Network/BitTorrent/Client.hs
+++ b/src/Network/BitTorrent/Client.hs
@@ -61,9 +61,9 @@ import Data.Text
 import Network
 
 import           Data.Torrent
+import           Network.BitTorrent.Address
 import           Network.BitTorrent.Client.Types
 import           Network.BitTorrent.Client.Handle
-import           Network.BitTorrent.Core
 import           Network.BitTorrent.DHT      as DHT      hiding (Options)
 import           Network.BitTorrent.Tracker  as Tracker  hiding (Options)
 import           Network.BitTorrent.Exchange as Exchange hiding (Options)
diff --git a/src/Network/BitTorrent/Client/Types.hs b/src/Network/BitTorrent/Client/Types.hs
index 3c1e9c9c..a5bf0cce 100644
--- a/src/Network/BitTorrent/Client/Types.hs
+++ b/src/Network/BitTorrent/Client/Types.hs
@@ -35,8 +35,8 @@ import Network
 import System.Log.FastLogger
 
 import Data.Torrent
+import Network.BitTorrent.Address
 import Network.BitTorrent.Internal.Types as Types
-import Network.BitTorrent.Core
 import Network.BitTorrent.DHT      as DHT
 import Network.BitTorrent.Exchange as Exchange
 import Network.BitTorrent.Tracker  as Tracker hiding (Event)
diff --git a/src/Network/BitTorrent/Core.hs b/src/Network/BitTorrent/Core.hs
deleted file mode 100644
index b9b3c065..00000000
--- a/src/Network/BitTorrent/Core.hs
+++ /dev/null
@@ -1,88 +0,0 @@
--- |
---   Copyright   :  (c) Sam Truzjan 2013
---   License     :  BSD3
---   Maintainer  :  pxqr.sta@gmail.com
---   Stability   :  experimental
---   Portability :  portable
---
---   Re-export every @Network.BitTorrent.Core.*@ module.
---
-module Network.BitTorrent.Core
-       ( module Core
-
-         -- * Address class
-       , Address (..)
-       , fromAddr
-
-         -- * Re-exports from Data.IP
-       , IPv4
-       , IPv6
-       , IP (..)
-       ) where
-
-import Control.Applicative
-import Data.IP
-import Data.Hashable
-import Data.Serialize
-import Data.Time
-import Data.Typeable
-import Network.Socket (SockAddr (..), PortNumber)
-import Text.PrettyPrint as PP hiding ((<>))
-import Text.PrettyPrint.Class
-
-import Network.BitTorrent.Core.Fingerprint as Core
-import Network.BitTorrent.Core.NodeInfo    as Core
-import Network.BitTorrent.Core.PeerId      as Core
-import Network.BitTorrent.Core.PeerAddr    as Core
-
-
-instance Pretty UTCTime where
-  pretty = PP.text . show
-
-class (Eq a, Serialize a, Typeable a, Hashable a, Pretty a)
-    => Address a where
-  toSockAddr   :: a        -> SockAddr
-  fromSockAddr :: SockAddr -> Maybe a
-
-fromAddr :: (Address a, Address b) => a -> Maybe b
-fromAddr = fromSockAddr . toSockAddr
-
--- | Note that port is zeroed.
-instance Address IPv4 where
-  toSockAddr = SockAddrInet 0 . toHostAddress
-  fromSockAddr (SockAddrInet _ h) = Just (fromHostAddress h)
-  fromSockAddr  _                 = Nothing
-
--- | Note that port is zeroed.
-instance Address IPv6 where
-  toSockAddr h = SockAddrInet6 0 0 (toHostAddress6 h) 0
-  fromSockAddr (SockAddrInet6 _ _ h _) = Just (fromHostAddress6 h)
-  fromSockAddr  _                      = Nothing
-
--- | Note that port is zeroed.
-instance Address IP where
-  toSockAddr (IPv4 h) = toSockAddr h
-  toSockAddr (IPv6 h) = toSockAddr h
-  fromSockAddr sa =
-        IPv4 <$> fromSockAddr sa
-    <|> IPv6 <$> fromSockAddr sa
-
-setPort :: PortNumber -> SockAddr -> SockAddr
-setPort port (SockAddrInet  _   h  ) = SockAddrInet  port   h
-setPort port (SockAddrInet6 _ f h s) = SockAddrInet6 port f h s
-setPort _    (SockAddrUnix  s      ) = SockAddrUnix  s
-{-# INLINE setPort #-}
-
-getPort :: SockAddr -> Maybe PortNumber
-getPort (SockAddrInet  p   _  ) = Just p
-getPort (SockAddrInet6 p _ _ _) = Just p
-getPort (SockAddrUnix  _      ) = Nothing
-{-# INLINE getPort #-}
-
-instance Address a => Address (NodeAddr a) where
-  toSockAddr NodeAddr {..} = setPort nodePort $ toSockAddr nodeHost
-  fromSockAddr sa = NodeAddr <$> fromSockAddr sa <*> getPort sa
-
-instance Address a => Address (PeerAddr a) where
-  toSockAddr PeerAddr {..} = setPort peerPort $ toSockAddr peerHost
-  fromSockAddr sa = PeerAddr Nothing <$> fromSockAddr sa <*> getPort sa
diff --git a/src/Network/BitTorrent/Core/Fingerprint.hs b/src/Network/BitTorrent/Core/Fingerprint.hs
deleted file mode 100644
index d743acd0..00000000
--- a/src/Network/BitTorrent/Core/Fingerprint.hs
+++ /dev/null
@@ -1,290 +0,0 @@
--- |
---   Copyright   :  (c) Sam Truzjan 2013
---   License     :  BSD3
---   Maintainer  :  pxqr.sta@gmail.com
---   Stability   :  experimental
---   Portability :  portable
---
---   'Fingerprint' is used to identify the client implementation and
---   version which also contained in 'Peer'. For exsample first 6
---   bytes of peer id of this this library are @-HS0100-@ while for
---   mainline we have @M4-3-6--@.  We could extract this info and
---   print in human-friendly form: this is useful for debugging and
---   logging.
---
---   For more information see:
---   <http://bittorrent.org/beps/bep_0020.html>
---
---
---   NOTE: Do /not/ use this information to control client
---   capabilities (such as supported enchancements), this should be
---   done using 'Network.BitTorrent.Extension'!
---
-{-# OPTIONS -fno-warn-orphans #-}
-module Network.BitTorrent.Core.Fingerprint
-       ( ClientImpl (..)
-       , Fingerprint (..)
-       , libFingerprint
-       , libUserAgent
-       ) where
-
-import Data.Default
-import Data.List as L
-import Data.List.Split as L
-import Data.Monoid
-import Data.String
-import Data.Version
-import Text.PrettyPrint hiding ((<>))
-import Text.PrettyPrint.Class
-import Text.Read (readMaybe)
--- import Paths_bittorrent (version)
-
--- TODO FIXME
-version :: Version
-version = Version [0, 0, 0, 3] []
-
--- | List of registered client versions + 'IlibHSbittorrent' (this
--- package) + 'IUnknown' (for not recognized software). All names are
--- prefixed by \"I\" because some of them starts from lowercase letter
--- but that is not a valid Haskell constructor name.
---
-data ClientImpl =
-   IUnknown
-
- | IMainline
-
- | IABC
- | IOspreyPermaseed
- | IBTQueue
- | ITribler
- | IShadow
- | IBitTornado
-
--- UPnP(!) Bit Torrent !???
--- 'U' - UPnP NAT Bit Torrent
- | IBitLord
- | IOpera
- | IMLdonkey
-
- | IAres
- | IArctic
- | IAvicora
- | IBitPump
- | IAzureus
- | IBitBuddy
- | IBitComet
- | IBitflu
- | IBTG
- | IBitRocket
- | IBTSlave
- | IBittorrentX
- | IEnhancedCTorrent
- | ICTorrent
- | IDelugeTorrent
- | IPropagateDataClient
- | IEBit
- | IElectricSheep
- | IFoxTorrent
- | IGSTorrent
- | IHalite
- | IlibHSbittorrent
- | IHydranode
- | IKGet
- | IKTorrent
- | ILH_ABC
- | ILphant
- | ILibtorrent
- | ILibTorrent
- | ILimeWire
- | IMonoTorrent
- | IMooPolice
- | IMiro
- | IMoonlightTorrent
- | INetTransport
- | IPando
- | IqBittorrent
- | IQQDownload
- | IQt4TorrentExample
- | IRetriever
- | IShareaza
- | ISwiftbit
- | ISwarmScope
- | ISymTorrent
- | Isharktorrent
- | ITorrentDotNET
- | ITransmission
- | ITorrentstorm
- | ITuoTu
- | IuLeecher
- | IuTorrent
- | IVagaa
- | IBitLet
- | IFireTorrent
- | IXunlei
- | IXanTorrent
- | IXtorrent
- | IZipTorrent
-   deriving (Show, Eq, Ord, Enum, Bounded)
-
--- | Used to represent a not recognized implementation
-instance Default ClientImpl where
-  def = IUnknown
-  {-# INLINE def #-}
-
--- | Example: @\"BitLet\" == 'IBitLet'@
-instance IsString ClientImpl where
-  fromString str
-    | Just impl <- L.lookup str alist = impl
-    | otherwise = error $ "fromString: not recognized " ++ str
-    where
-      alist = L.map mk [minBound..maxBound]
-      mk  x = (L.tail $ show x, x)
-
--- | Example: @pretty 'IBitLet' == \"IBitLet\"@
-instance Pretty ClientImpl where
-  pretty = text . L.tail . show
-
--- | Just the '0' version.
-instance Default Version where
-  def = Version [0] []
-  {-# INLINE def #-}
-
--- | For dot delimited version strings.
---   Example: @fromString \"0.1.0.2\" == Version [0, 1, 0, 2]@
---
-instance IsString Version where
-  fromString str
-    | Just nums <- chunkNums str = Version nums []
-    | otherwise = error $ "fromString: invalid version string " ++ str
-    where
-      chunkNums = sequence . L.map readMaybe . L.linesBy ('.' ==)
-
-instance Pretty Version where
-  pretty = text . showVersion
-
--- | The all sensible infomation that can be obtained from a peer
--- identifier or torrent /createdBy/ field.
-data Fingerprint = Fingerprint
-  { ciImpl    :: ClientImpl
-  , ciVersion :: Version
-  } deriving (Show, Eq, Ord)
-
--- | Unrecognized client implementation.
-instance Default Fingerprint where
-  def = Fingerprint def def
-  {-# INLINE def #-}
-
--- | Example: @\"BitComet-1.2\" == ClientInfo IBitComet (Version [1, 2] [])@
-instance IsString Fingerprint where
-  fromString str
-    | _ : ver <- _ver = Fingerprint (fromString impl) (fromString ver)
-    | otherwise = error $ "fromString: invalid client info string" ++ str
-    where
-      (impl, _ver) = L.span ((/=) '-') str
-
-instance Pretty Fingerprint where
-  pretty Fingerprint {..} = pretty ciImpl <+> "version" <+> pretty ciVersion
-
--- | Fingerprint of this (the bittorrent library) package. Normally,
--- applications should introduce its own fingerprints, otherwise they
--- can use 'libFingerprint' value.
---
-libFingerprint :: Fingerprint
-libFingerprint =  Fingerprint IlibHSbittorrent version
-
--- | HTTP user agent of this (the bittorrent library) package. Can be
--- used in HTTP tracker requests.
-libUserAgent :: String
-libUserAgent = render (pretty IlibHSbittorrent <> "/" <> pretty version)
-
-{-----------------------------------------------------------------------
---  For torrent file
------------------------------------------------------------------------}
--- TODO collect information about createdBy torrent field
-{-
-renderImpl :: ClientImpl -> Text
-renderImpl = T.pack . L.tail . show
-
-renderVersion :: Version -> Text
-renderVersion = undefined
-
-renderClientInfo :: ClientInfo -> Text
-renderClientInfo ClientInfo {..} = renderImpl ciImpl <> "/" <> renderVersion ciVersion
-
-parseClientInfo :: Text -> ClientImpl
-parseClientInfo t = undefined
--}
-{-
--- code used for generation; remove it later on
-
-mkEnumTyDef :: NM -> String
-mkEnumTyDef = unlines . map (" | I" ++) . nub . map snd
-
-mkPars :: NM -> String
-mkPars = unlines . map (\(code, impl) -> "  f \"" ++ code ++ "\" = " ++ "I" ++ impl)
-
-type NM = [(String, String)]
-nameMap :: NM
-nameMap =
- [ ("AG", "Ares")
- , ("A~", "Ares")
- , ("AR", "Arctic")
- , ("AV", "Avicora")
- , ("AX", "BitPump")
- , ("AZ", "Azureus")
- , ("BB", "BitBuddy")
- , ("BC", "BitComet")
- , ("BF", "Bitflu")
- , ("BG", "BTG")
- , ("BR", "BitRocket")
- , ("BS", "BTSlave")
- , ("BX", "BittorrentX")
- , ("CD", "EnhancedCTorrent")
- , ("CT", "CTorrent")
- , ("DE", "DelugeTorrent")
- , ("DP", "PropagateDataClient")
- , ("EB", "EBit")
- , ("ES", "ElectricSheep")
- , ("FT", "FoxTorrent")
- , ("GS", "GSTorrent")
- , ("HL", "Halite")
- , ("HS", "libHSnetwork_bittorrent")
- , ("HN", "Hydranode")
- , ("KG", "KGet")
- , ("KT", "KTorrent")
- , ("LH", "LH_ABC")
- , ("LP", "Lphant")
- , ("LT", "Libtorrent")
- , ("lt", "LibTorrent")
- , ("LW", "LimeWire")
- , ("MO", "MonoTorrent")
- , ("MP", "MooPolice")
- , ("MR", "Miro")
- , ("MT", "MoonlightTorrent")
- , ("NX", "NetTransport")
- , ("PD", "Pando")
- , ("qB", "qBittorrent")
- , ("QD", "QQDownload")
- , ("QT", "Qt4TorrentExample")
- , ("RT", "Retriever")
- , ("S~", "Shareaza")
- , ("SB", "Swiftbit")
- , ("SS", "SwarmScope")
- , ("ST", "SymTorrent")
- , ("st", "sharktorrent")
- , ("SZ", "Shareaza")
- , ("TN", "TorrentDotNET")
- , ("TR", "Transmission")
- , ("TS", "Torrentstorm")
- , ("TT", "TuoTu")
- , ("UL", "uLeecher")
- , ("UT", "uTorrent")
- , ("VG", "Vagaa")
- , ("WT", "BitLet")
- , ("WY", "FireTorrent")
- , ("XL", "Xunlei")
- , ("XT", "XanTorrent")
- , ("XX", "Xtorrent")
- , ("ZT", "ZipTorrent")
- ]
--}
diff --git a/src/Network/BitTorrent/Core/NodeInfo.hs b/src/Network/BitTorrent/Core/NodeInfo.hs
deleted file mode 100644
index fe17c097..00000000
--- a/src/Network/BitTorrent/Core/NodeInfo.hs
+++ /dev/null
@@ -1,219 +0,0 @@
--- |
---   Module      :  Network.BitTorrent.Core.Node
---   Copyright   :  (c) Sam Truzjan 2013
---                  (c) Daniel Gröber 2013
---   License     :  BSD3
---   Maintainer  :  pxqr.sta@gmail.com
---   Stability   :  experimental
---   Portability :  portable
---
---   A \"node\" is a client\/server listening on a UDP port
---   implementing the distributed hash table protocol. The DHT is
---   composed of nodes and stores the location of peers. BitTorrent
---   clients include a DHT node, which is used to contact other nodes
---   in the DHT to get the location of peers to download from using
---   the BitTorrent protocol.
---
-{-# LANGUAGE RecordWildCards            #-}
-{-# LANGUAGE FlexibleInstances          #-}
-{-# LANGUAGE TemplateHaskell            #-}
-{-# LANGUAGE GeneralizedNewtypeDeriving #-}
-{-# LANGUAGE DeriveDataTypeable         #-}
-{-# LANGUAGE DeriveFunctor              #-}
-module Network.BitTorrent.Core.NodeInfo
-       (  -- * Node ID
-         NodeId
-       , testIdBit
-       , genNodeId
-
-         -- ** Node distance
-       , NodeDistance
-       , distance
-
-         -- * Node address
-       , NodeAddr (..)
-
-         -- * Node info
-       , NodeInfo (..)
-       , rank
-       ) where
-
-import Control.Applicative
-import Data.Bits
-import Data.ByteString as BS
-import Data.ByteString.Char8 as BC
-import Data.ByteString.Base16 as Base16
-import Data.BEncode as BE
-import Data.Default
-import Data.Hashable
-import Data.Foldable
-import Data.IP
-import Data.List as L
-import Data.Monoid
-import Data.Ord
-import Data.Serialize as S
-import Data.String
-import Data.Typeable
-import Data.Word
-import Network
-import System.Entropy
-import Text.PrettyPrint as PP hiding ((<>))
-import Text.PrettyPrint.Class
-
-import Network.BitTorrent.Core.PeerAddr (PeerAddr (..))
-
-{-----------------------------------------------------------------------
---  Node id
------------------------------------------------------------------------}
--- TODO more compact representation ('ShortByteString's?)
-
--- | Each node has a globally unique identifier known as the \"node
--- ID.\"
---
---   Normally, /this/ node id should be saved between invocations
---   of the client software.
-newtype NodeId = NodeId ByteString
-  deriving (Show, Eq, Ord, BEncode, Typeable)
-
-nodeIdSize :: Int
-nodeIdSize = 20
-
--- | Meaningless node id, for testing purposes only.
-instance Default NodeId where
-  def = NodeId (BS.replicate nodeIdSize 0)
-
-instance Serialize NodeId where
-  get = NodeId <$> getByteString nodeIdSize
-  {-# INLINE get #-}
-  put (NodeId bs) = putByteString bs
-  {-# INLINE put #-}
-
--- | ASCII encoded.
-instance IsString NodeId where
-  fromString str
-    | L.length str == nodeIdSize = NodeId (fromString str)
-    |           otherwise = error "fromString: invalid NodeId length"
-  {-# INLINE fromString #-}
-
--- | base16 encoded.
-instance Pretty NodeId where
-  pretty (NodeId nid) = PP.text $ BC.unpack $ Base16.encode nid
-
--- | Test if the nth bit is set.
-testIdBit :: NodeId -> Word -> Bool
-testIdBit (NodeId bs) i
-  | fromIntegral i < nodeIdSize * 8
-  , (q, r) <- quotRem (fromIntegral i) 8
-  = testBit (BS.index bs q) r
-  |     otherwise      = False
-{-# INLINE testIdBit #-}
-
--- TODO WARN is the 'system' random suitable for this?
--- | Generate random NodeID used for the entire session.
---   Distribution of ID's should be as uniform as possible.
---
-genNodeId :: IO NodeId
-genNodeId = NodeId <$> getEntropy nodeIdSize
-
-{-----------------------------------------------------------------------
---  Node distance
------------------------------------------------------------------------}
-
--- | In Kademlia, the distance metric is XOR and the result is
--- interpreted as an unsigned integer.
-newtype NodeDistance = NodeDistance BS.ByteString
-  deriving (Eq, Ord)
-
-instance Pretty NodeDistance where
-  pretty (NodeDistance bs) = foldMap bitseq $ BS.unpack bs
-    where
-      listBits w = L.map (testBit w) (L.reverse [0..bitSize w - 1])
-      bitseq = foldMap (int . fromEnum) . listBits
-
--- | distance(A,B) = |A xor B| Smaller values are closer.
-distance :: NodeId -> NodeId -> NodeDistance
-distance (NodeId a) (NodeId b) = NodeDistance (BS.pack (BS.zipWith xor a b))
-
-{-----------------------------------------------------------------------
---  Node address
------------------------------------------------------------------------}
-
-data NodeAddr a = NodeAddr
-  { nodeHost ::                !a
-  , nodePort :: {-# UNPACK #-} !PortNumber
-  } deriving (Eq, Typeable, Functor)
-
-instance Show a => Show (NodeAddr a) where
-  showsPrec i NodeAddr {..}
-    = showsPrec i nodeHost <> showString ":" <> showsPrec i nodePort
-
-instance Read (NodeAddr IPv4) where
-  readsPrec i x = [ (fromPeerAddr a, s) | (a, s) <- readsPrec i x ]
-
--- | @127.0.0.1:6882@
-instance Default (NodeAddr IPv4) where
-  def = "127.0.0.1:6882"
-
--- | KRPC compatible encoding.
-instance Serialize a => Serialize (NodeAddr a) where
-  get = NodeAddr <$> get <*> get
-  {-# INLINE get #-}
-  put NodeAddr {..} = put nodeHost >> put nodePort
-  {-# INLINE put #-}
-
--- | Torrent file compatible encoding.
-instance BEncode a => BEncode (NodeAddr a) where
-  toBEncode NodeAddr {..} = toBEncode (nodeHost, nodePort)
-  {-# INLINE toBEncode #-}
-  fromBEncode b = uncurry NodeAddr <$> fromBEncode b
-  {-# INLINE fromBEncode #-}
-
-instance Hashable a => Hashable (NodeAddr a) where
-  hashWithSalt s NodeAddr {..} = hashWithSalt s (nodeHost, nodePort)
-  {-# INLINE hashWithSalt #-}
-
-instance Pretty ip => Pretty (NodeAddr ip) where
-  pretty NodeAddr {..} = pretty nodeHost <> ":" <> pretty nodePort
-
--- | Example:
---
---   @nodePort \"127.0.0.1:6881\" == 6881@
---
-instance IsString (NodeAddr IPv4) where
-  fromString = fromPeerAddr . fromString
-
-fromPeerAddr :: PeerAddr a -> NodeAddr a
-fromPeerAddr PeerAddr {..} = NodeAddr
-  { nodeHost = peerHost
-  , nodePort = peerPort
-  }
-
-{-----------------------------------------------------------------------
---  Node info
------------------------------------------------------------------------}
-
-data NodeInfo a = NodeInfo
-  { nodeId   :: !NodeId
-  , nodeAddr :: !(NodeAddr a)
-  } deriving (Show, Eq, Functor)
-
-instance Eq a => Ord (NodeInfo a) where
-  compare = comparing nodeId
-
--- | KRPC 'compact list' compatible encoding: contact information for
--- nodes is encoded as a 26-byte string. Also known as "Compact node
--- info" the 20-byte Node ID in network byte order has the compact
--- IP-address/port info concatenated to the end.
-instance Serialize a => Serialize (NodeInfo a) where
-  get = NodeInfo <$> get <*> get
-  put NodeInfo {..} = put nodeId >> put nodeAddr
-
-instance Pretty ip => Pretty (NodeInfo ip) where
-  pretty NodeInfo {..} = pretty nodeId <> "@(" <> pretty nodeAddr <> ")"
-
-instance Pretty ip => Pretty [NodeInfo ip] where
-  pretty = PP.vcat . PP.punctuate "," . L.map pretty
-
--- | Order by closeness: nearest nodes first.
-rank :: Eq ip => NodeId -> [NodeInfo ip] -> [NodeInfo ip]
-rank nid = L.sortBy (comparing (distance nid . nodeId))
diff --git a/src/Network/BitTorrent/Core/PeerAddr.hs b/src/Network/BitTorrent/Core/PeerAddr.hs
deleted file mode 100644
index e9ad7c96..00000000
--- a/src/Network/BitTorrent/Core/PeerAddr.hs
+++ /dev/null
@@ -1,312 +0,0 @@
--- |
---   Module      :  Network.BitTorrent.Core.PeerAddr
---   Copyright   :  (c) Sam Truzjan 2013
---                  (c) Daniel Gröber 2013
---   License     :  BSD3
---   Maintainer  :  pxqr.sta@gmail.com
---   Stability   :  provisional
---   Portability :  portable
---
---   'PeerAddr' is used to represent peer address. Currently it's
---   just peer IP and peer port but this might change in future.
---
-{-# LANGUAGE TemplateHaskell            #-}
-{-# LANGUAGE StandaloneDeriving         #-}
-{-# LANGUAGE GeneralizedNewtypeDeriving #-}
-{-# LANGUAGE DeriveDataTypeable         #-}
-{-# LANGUAGE FlexibleInstances          #-}
-{-# LANGUAGE DeriveFunctor              #-}
-{-# LANGUAGE ViewPatterns               #-}
-{-# OPTIONS -fno-warn-orphans           #-} -- for PortNumber instances
-module Network.BitTorrent.Core.PeerAddr
-       ( -- * Peer address
-         PeerAddr(..)
-       , defaultPorts
-       , peerSockAddr
-       , peerSocket
-
-         -- * Peer storage
-       ) where
-
-import Control.Applicative
-import Control.Monad
-import Data.BEncode   as BS
-import Data.BEncode.BDict (BKey)
-import Data.ByteString.Char8 as BS8
-import Data.Char
-import Data.Default
-import Data.Hashable
-import Data.IP
-import Data.List      as L
-import Data.List.Split
-import Data.Monoid
-import Data.Serialize as S
-import Data.String
-import Data.Typeable
-import Data.Word
-import Network.Socket
-import Text.PrettyPrint as PP hiding ((<>))
-import Text.PrettyPrint.Class
-import Text.Read (readMaybe)
-import qualified Text.ParserCombinators.ReadP as RP
-
---import Data.Torrent
-import Network.BitTorrent.Core.PeerId
-
-
-{-----------------------------------------------------------------------
---  Port number
------------------------------------------------------------------------}
-
-instance BEncode PortNumber where
-  toBEncode   = toBEncode    .  fromEnum
-  fromBEncode = fromBEncode >=> portNumber
-    where
-      portNumber :: Integer -> BS.Result PortNumber
-      portNumber n
-        | 0 <= n && n <= fromIntegral (maxBound :: Word16)
-        = pure $ fromIntegral n
-        | otherwise = decodingError $ "PortNumber: " ++ show n
-
-instance Serialize PortNumber where
-  get = fromIntegral <$> getWord16be
-  {-# INLINE get #-}
-  put = putWord16be . fromIntegral
-  {-# INLINE put #-}
-
-instance Hashable PortNumber where
-  hashWithSalt s = hashWithSalt s . fromEnum
-  {-# INLINE hashWithSalt #-}
-
-instance Pretty PortNumber where
-  pretty = PP.int . fromEnum
-  {-# INLINE pretty #-}
-
-{-----------------------------------------------------------------------
---  IP addr
------------------------------------------------------------------------}
-
-class IPAddress i where
-  toHostAddr :: i -> Either HostAddress HostAddress6
-
-instance IPAddress IPv4 where
-  toHostAddr = Left . toHostAddress
-  {-# INLINE toHostAddr #-}
-
-instance IPAddress IPv6 where
-  toHostAddr = Right . toHostAddress6
-  {-# INLINE toHostAddr #-}
-
-instance IPAddress IP where
-  toHostAddr (IPv4 ip) = toHostAddr ip
-  toHostAddr (IPv6 ip) = toHostAddr ip
-  {-# INLINE toHostAddr #-}
-
-deriving instance Typeable IP
-deriving instance Typeable IPv4
-deriving instance Typeable IPv6
-
-ipToBEncode :: Show i => i -> BValue
-ipToBEncode ip = BString $ BS8.pack $ show ip
-{-# INLINE ipToBEncode #-}
-
-ipFromBEncode :: Read a => BValue -> BS.Result a
-ipFromBEncode (BString (BS8.unpack -> ipStr))
-  | Just ip <- readMaybe (ipStr) = pure ip
-  |         otherwise            = decodingError $ "IP: " ++ ipStr
-ipFromBEncode _    = decodingError $ "IP: addr should be a bstring"
-
-instance BEncode IP where
-  toBEncode   = ipToBEncode
-  {-# INLINE toBEncode #-}
-  fromBEncode = ipFromBEncode
-  {-# INLINE fromBEncode #-}
-
-instance BEncode IPv4 where
-  toBEncode   = ipToBEncode
-  {-# INLINE toBEncode #-}
-  fromBEncode = ipFromBEncode
-  {-# INLINE fromBEncode #-}
-
-instance BEncode IPv6 where
-  toBEncode   = ipToBEncode
-  {-# INLINE toBEncode #-}
-  fromBEncode = ipFromBEncode
-  {-# INLINE fromBEncode #-}
-
--- | When 'get'ing an IP it must be 'isolate'd to the appropriate
--- number of bytes since we have no other way of telling which
--- address type we are trying to parse
-instance Serialize IP where
-    put (IPv4 ip) = put ip
-    put (IPv6 ip) = put ip
-
-    get = do
-      n <- remaining
-      case n of
-        4  -> IPv4 <$> get
-        16 -> IPv6 <$> get
-        _ -> fail "Wrong number of bytes remaining to parse IP"
-
-instance Serialize IPv4 where
-    put = putWord32host    .  toHostAddress
-    get = fromHostAddress <$> getWord32host
-
-instance Serialize IPv6 where
-    put ip = put $ toHostAddress6 ip
-    get = fromHostAddress6 <$> get
-
-instance Pretty IPv4 where
-  pretty = PP.text . show
-  {-# INLINE pretty #-}
-
-instance Pretty IPv6 where
-  pretty = PP.text . show
-  {-# INLINE pretty #-}
-
-instance Pretty IP where
-  pretty = PP.text . show
-  {-# INLINE pretty #-}
-
-instance Hashable IPv4 where
-  hashWithSalt = hashUsing toHostAddress
-  {-# INLINE hashWithSalt #-}
-
-instance Hashable IPv6 where
-  hashWithSalt s a = hashWithSalt s (toHostAddress6 a)
-
-instance Hashable IP where
-  hashWithSalt s (IPv4 h) = hashWithSalt s h
-  hashWithSalt s (IPv6 h) = hashWithSalt s h
-
-{-----------------------------------------------------------------------
---  Peer addr
------------------------------------------------------------------------}
--- TODO check semantic of ord and eq instances
-
--- | Peer address info normally extracted from peer list or peer
--- compact list encoding.
-data PeerAddr a = PeerAddr
-  { peerId   :: !(Maybe PeerId)
-
-    -- | This is usually 'IPv4', 'IPv6', 'IP' or unresolved
-    -- 'HostName'.
-  , peerHost :: !a
-
-    -- | The port the peer listenning for incoming P2P sessions.
-  , peerPort :: {-# UNPACK #-} !PortNumber
-  } deriving (Show, Eq, Ord, Typeable, Functor)
-
-peer_ip_key, peer_id_key, peer_port_key :: BKey
-peer_ip_key   = "ip"
-peer_id_key   = "peer id"
-peer_port_key = "port"
-
--- | The tracker's 'announce response' compatible encoding.
-instance (Typeable a, BEncode a) => BEncode (PeerAddr a) where
-  toBEncode PeerAddr {..} = toDict $
-       peer_ip_key   .=! peerHost
-    .: peer_id_key   .=? peerId
-    .: peer_port_key .=! peerPort
-    .: endDict
-
-  fromBEncode = fromDict $ do
-    peerAddr <$>! peer_ip_key
-             <*>? peer_id_key
-             <*>! peer_port_key
-    where
-      peerAddr = flip PeerAddr
-
--- | The tracker's 'compact peer list' compatible encoding. The
--- 'peerId' is always 'Nothing'.
---
---   For more info see: <http://www.bittorrent.org/beps/bep_0023.html>
---
--- TODO: test byte order
-instance (Serialize a) => Serialize (PeerAddr a) where
-  put PeerAddr {..} = put peerHost >> put peerPort
-  get = PeerAddr Nothing <$> get <*> get
-
--- | @127.0.0.1:6881@
-instance Default (PeerAddr IPv4) where
-  def = "127.0.0.1:6881"
-
--- | @127.0.0.1:6881@
-instance Default (PeerAddr IP) where
-  def = IPv4 <$> def
-
--- | Example:
---
---   @peerPort \"127.0.0.1:6881\" == 6881@
---
-instance IsString (PeerAddr IPv4) where
-  fromString str
-    | [hostAddrStr, portStr] <- splitWhen (== ':') str
-    , Just hostAddr <- readMaybe hostAddrStr
-    , Just portNum  <- toEnum <$> readMaybe portStr
-                = PeerAddr Nothing hostAddr portNum
-    | otherwise = error $ "fromString: unable to parse (PeerAddr IPv4): " ++ str
-
-instance Read (PeerAddr IPv4) where
-  readsPrec i = RP.readP_to_S $ do
-    ipv4 <- RP.readS_to_P (readsPrec i)
-    _    <- RP.char ':'
-    port <- toEnum <$> RP.readS_to_P (readsPrec i)
-    return $ PeerAddr Nothing ipv4 port
-
-readsIPv6_port :: String -> [((IPv6, PortNumber), String)]
-readsIPv6_port = RP.readP_to_S $ do
-  ip <- RP.char '[' *> (RP.readS_to_P reads) <* RP.char ']'
-  _ <- RP.char ':'
-  port <- toEnum <$> read <$> (RP.many1 $ RP.satisfy isDigit) <* RP.eof
-  return (ip,port)
-
-instance IsString (PeerAddr IPv6) where
-  fromString str
-    | [((ip,port),"")] <- readsIPv6_port str =
-        PeerAddr Nothing ip port
-    | otherwise = error $ "fromString: unable to parse (PeerAddr IPv6): " ++ str
-
-instance IsString (PeerAddr IP) where
-  fromString str
-    | '[' `L.elem` str = IPv6 <$> fromString str
-    |      otherwise   = IPv4 <$> fromString str
-
--- | fingerprint + "at" + dotted.host.inet.addr:port
--- TODO: instances for IPv6, HostName
-instance Pretty a => Pretty (PeerAddr a) where
-  pretty PeerAddr {..}
-    | Just pid <- peerId = pretty (fingerprint pid) <+> "at" <+> paddr
-    |     otherwise      = paddr
-    where
-      paddr = pretty peerHost <> ":" <> text (show peerPort)
-
-instance Hashable a => Hashable (PeerAddr a) where
-  hashWithSalt s PeerAddr {..} =
-    s `hashWithSalt` peerId `hashWithSalt` peerHost `hashWithSalt` peerPort
-
--- | Ports typically reserved for bittorrent P2P listener.
-defaultPorts :: [PortNumber]
-defaultPorts =  [6881..6889]
-
-_resolvePeerAddr :: (IPAddress i) => PeerAddr HostName -> PeerAddr i
-_resolvePeerAddr = undefined
-
-_peerSockAddr :: PeerAddr IP -> (Family, SockAddr)
-_peerSockAddr PeerAddr {..} =
-    case peerHost of
-          IPv4 ipv4 ->
-              (AF_INET, SockAddrInet peerPort (toHostAddress  ipv4))
-          IPv6 ipv6 ->
-              (AF_INET6, SockAddrInet6 peerPort 0 (toHostAddress6 ipv6) 0)
-
-peerSockAddr :: PeerAddr IP -> SockAddr
-peerSockAddr = snd . _peerSockAddr
-
--- | Create a socket connected to the address specified in a peerAddr
-peerSocket :: SocketType -> PeerAddr IP -> IO Socket
-peerSocket socketType pa = do
-    let (family, addr) = _peerSockAddr pa
-    sock <- socket family socketType defaultProtocol
-    connect sock addr
-    return sock
diff --git a/src/Network/BitTorrent/Core/PeerId.hs b/src/Network/BitTorrent/Core/PeerId.hs
deleted file mode 100644
index a180ff30..00000000
--- a/src/Network/BitTorrent/Core/PeerId.hs
+++ /dev/null
@@ -1,364 +0,0 @@
--- |
---   Copyright   :  (c) Sam Truzjan 2013
---   License     :  BSD3
---   Maintainer  :  pxqr.sta@gmail.com
---   Stability   :  experimental
---   Portability :  portable
---
---  'PeerID' represent self assigned peer identificator. Ideally each
---  host in the network should have unique peer id to avoid
---  collisions, therefore for peer ID generation we use good entropy
---  source. Peer ID is sent in /tracker request/, sent and received in
---  /peer handshakes/ and used in DHT queries.
---
-{-# LANGUAGE GeneralizedNewtypeDeriving #-}
-{-# LANGUAGE MultiParamTypeClasses      #-}
-{-# LANGUAGE DeriveDataTypeable         #-}
-module Network.BitTorrent.Core.PeerId
-       ( -- * PeerId
-         PeerId
-
-         -- * Generation
-       , genPeerId
-       , timestamp
-       , entropy
-
-         -- * Encoding
-       , azureusStyle
-       , shadowStyle
-       , defaultClientId
-       , defaultVersionNumber
-
-         -- * Decoding
-       , fingerprint
-       ) where
-
-import Control.Applicative
-import Data.BEncode as BE
-import Data.ByteString as BS
-import Data.ByteString.Internal as BS
-import Data.ByteString.Char8 as BC
-import qualified Data.ByteString.Lazy as BL
-import qualified Data.ByteString.Lazy.Builder as BS
-import Data.Convertible
-import Data.Default
-import Data.Foldable    (foldMap)
-import Data.List as L
-import Data.List.Split as L
-import Data.Maybe       (fromMaybe, catMaybes)
-import Data.Monoid
-import Data.Hashable
-import Data.Serialize as S
-import Data.String
-import Data.Time.Clock  (getCurrentTime)
-import Data.Time.Format (formatTime)
-import Data.Typeable
-import Data.Version     (Version(Version), versionBranch)
-import Network.HTTP.Types.QueryLike
-import System.Entropy   (getEntropy)
-import System.Locale    (defaultTimeLocale)
-import Text.PrettyPrint hiding ((<>))
-import Text.PrettyPrint.Class
-import Text.Read        (readMaybe)
-
-import Network.BitTorrent.Core.Fingerprint
-
--- TODO use unpacked Word160 form (length is known statically)
-
--- | Peer identifier is exactly 20 bytes long bytestring.
-newtype PeerId = PeerId { getPeerId :: ByteString }
-  deriving (Show, Eq, Ord, BEncode, Typeable)
-
-peerIdLen :: Int
-peerIdLen = 20
-
--- | For testing purposes only.
-instance Default PeerId where
-  def = azureusStyle defaultClientId defaultVersionNumber ""
-
-instance Hashable PeerId where
-  hashWithSalt = hashUsing getPeerId
-  {-# INLINE hashWithSalt #-}
-
-instance Serialize PeerId where
-  put = putByteString . getPeerId
-  get = PeerId <$> getBytes peerIdLen
-
-instance QueryValueLike PeerId where
-  toQueryValue (PeerId pid) = Just pid
-  {-# INLINE toQueryValue #-}
-
-instance IsString PeerId where
-  fromString str
-      | BS.length bs == peerIdLen = PeerId bs
-      | otherwise = error $ "Peer id should be 20 bytes long: " ++ show str
-    where
-      bs = fromString str
-
-instance Pretty PeerId where
-  pretty = text . BC.unpack . getPeerId
-
-instance Convertible BS.ByteString PeerId where
-  safeConvert bs
-    | BS.length bs == peerIdLen = pure (PeerId bs)
-    |          otherwise        = convError "invalid length" bs
-
-{-----------------------------------------------------------------------
---  Encoding
------------------------------------------------------------------------}
-
--- | Pad bytestring so it's becomes exactly request length. Conversion
--- is done like so:
---
---     * length < size: Complete bytestring by given charaters.
---
---     * length = size: Output bytestring as is.
---
---     * length > size: Drop last (length - size) charaters from a
---     given bytestring.
---
-byteStringPadded :: ByteString -- ^ bytestring to be padded.
-                 -> Int        -- ^ size of result builder.
-                 -> Char       -- ^ character used for padding.
-                 -> BS.Builder
-byteStringPadded bs s c =
-      BS.byteString (BS.take s bs) <>
-      BS.byteString (BC.replicate padLen c)
-  where
-    padLen = s - min (BS.length bs) s
-
--- | Azureus-style encoding have the following layout:
---
---     * 1  byte : '-'
---
---     * 2  bytes: client id
---
---     * 4  bytes: version number
---
---     * 1  byte : '-'
---
---     * 12 bytes: random number
---
-azureusStyle :: ByteString -- ^ 2 character client ID, padded with 'H'.
-             -> ByteString -- ^ Version number, padded with 'X'.
-             -> ByteString -- ^ Random number, padded with '0'.
-             -> PeerId     -- ^ Azureus-style encoded peer ID.
-azureusStyle cid ver rnd = PeerId $ BL.toStrict $ BS.toLazyByteString $
-    BS.char8 '-' <>
-      byteStringPadded cid 2  'H' <>
-      byteStringPadded ver 4  'X' <>
-    BS.char8 '-' <>
-      byteStringPadded rnd 12 '0'
-
--- | Shadow-style encoding have the following layout:
---
---     * 1 byte   : client id.
---
---     * 0-4 bytes: version number. If less than 4 then padded with
---     '-' char.
---
---     * 15 bytes : random number. If length is less than 15 then
---     padded with '0' char.
---
-shadowStyle :: Char       -- ^ Client ID.
-            -> ByteString -- ^ Version number.
-            -> ByteString -- ^ Random number.
-            -> PeerId     -- ^ Shadow style encoded peer ID.
-shadowStyle cid ver rnd = PeerId $ BL.toStrict $ BS.toLazyByteString $
-    BS.char8 cid <>
-      byteStringPadded ver 4  '-' <>
-      byteStringPadded rnd 15 '0'
-
-
--- | 'HS'- 2 bytes long client identifier.
-defaultClientId :: ByteString
-defaultClientId = "HS"
-
--- | Gives exactly 4 bytes long version number for any version of the
--- package.  Version is taken from .cabal file.
-defaultVersionNumber :: ByteString
-defaultVersionNumber = BS.take 4 $ BC.pack $ foldMap show $
-                         versionBranch $ ciVersion libFingerprint
-
-{-----------------------------------------------------------------------
---  Generation
------------------------------------------------------------------------}
-
--- | Gives 15 characters long decimal timestamp such that:
---
---     * 6 bytes   : first 6 characters from picoseconds obtained with %q.
---
---     * 1 byte    : character \'.\' for readability.
---
---     * 9..* bytes: number of whole seconds since the Unix epoch
---     (!)REVERSED.
---
---   Can be used both with shadow and azureus style encoding. This
---   format is used to make the ID's readable for debugging purposes.
---
-timestamp :: IO ByteString
-timestamp = (BC.pack . format) <$> getCurrentTime
-  where
-    format t = L.take 6 (formatTime defaultTimeLocale "%q" t) ++ "." ++
-               L.take 9 (L.reverse (formatTime defaultTimeLocale "%s" t))
-
--- | Gives 15 character long random bytestring. This is more robust
--- method for generation of random part of peer ID than 'timestamp'.
-entropy :: IO ByteString
-entropy = getEntropy 15
-
--- NOTE: entropy generates incorrrect peer id
-
--- |  Here we use 'azureusStyle' encoding with the following args:
---
---      * 'HS' for the client id; ('defaultClientId')
---
---      * Version of the package for the version number;
---      ('defaultVersionNumber')
---
---      * UTC time day ++ day time for the random number. ('timestamp')
---
-genPeerId :: IO PeerId
-genPeerId = azureusStyle defaultClientId defaultVersionNumber <$> timestamp
-
-{-----------------------------------------------------------------------
---  Decoding
------------------------------------------------------------------------}
-
-parseImpl :: ByteString -> ClientImpl
-parseImpl = f . BC.unpack
- where
-  f "AG" = IAres
-  f "A~" = IAres
-  f "AR" = IArctic
-  f "AV" = IAvicora
-  f "AX" = IBitPump
-  f "AZ" = IAzureus
-  f "BB" = IBitBuddy
-  f "BC" = IBitComet
-  f "BF" = IBitflu
-  f "BG" = IBTG
-  f "BR" = IBitRocket
-  f "BS" = IBTSlave
-  f "BX" = IBittorrentX
-  f "CD" = IEnhancedCTorrent
-  f "CT" = ICTorrent
-  f "DE" = IDelugeTorrent
-  f "DP" = IPropagateDataClient
-  f "EB" = IEBit
-  f "ES" = IElectricSheep
-  f "FT" = IFoxTorrent
-  f "GS" = IGSTorrent
-  f "HL" = IHalite
-  f "HS" = IlibHSbittorrent
-  f "HN" = IHydranode
-  f "KG" = IKGet
-  f "KT" = IKTorrent
-  f "LH" = ILH_ABC
-  f "LP" = ILphant
-  f "LT" = ILibtorrent
-  f "lt" = ILibTorrent
-  f "LW" = ILimeWire
-  f "MO" = IMonoTorrent
-  f "MP" = IMooPolice
-  f "MR" = IMiro
-  f "ML" = IMLdonkey
-  f "MT" = IMoonlightTorrent
-  f "NX" = INetTransport
-  f "PD" = IPando
-  f "qB" = IqBittorrent
-  f "QD" = IQQDownload
-  f "QT" = IQt4TorrentExample
-  f "RT" = IRetriever
-  f "S~" = IShareaza
-  f "SB" = ISwiftbit
-  f "SS" = ISwarmScope
-  f "ST" = ISymTorrent
-  f "st" = Isharktorrent
-  f "SZ" = IShareaza
-  f "TN" = ITorrentDotNET
-  f "TR" = ITransmission
-  f "TS" = ITorrentstorm
-  f "TT" = ITuoTu
-  f "UL" = IuLeecher
-  f "UT" = IuTorrent
-  f "VG" = IVagaa
-  f "WT" = IBitLet
-  f "WY" = IFireTorrent
-  f "XL" = IXunlei
-  f "XT" = IXanTorrent
-  f "XX" = IXtorrent
-  f "ZT" = IZipTorrent
-  f _    = IUnknown
-
--- TODO use regexps
-
--- | Tries to extract meaningful information from peer ID bytes. If
--- peer id uses unknown coding style then client info returned is
--- 'def'.
---
-fingerprint :: PeerId -> Fingerprint
-fingerprint pid = either (const def) id $ runGet getCI (getPeerId pid)
-  where
-    getCI    = do
-      leading <- BS.w2c <$> getWord8
-      case leading of
-        '-' -> Fingerprint <$> getAzureusImpl <*> getAzureusVersion
-        'M' -> Fingerprint <$> pure IMainline <*> getMainlineVersion
-        'e' -> Fingerprint <$> getBitCometImpl <*> getBitCometVersion
-        'F' -> Fingerprint <$> getBitCometImpl <*> getBitCometVersion
-        c   -> do
-          c1 <- w2c <$> S.lookAhead getWord8
-          if c1 == 'P'
-            then do
-                 _ <- getWord8
-                 Fingerprint <$> pure IOpera            <*> getOperaVersion
-            else Fingerprint <$> pure (getShadowImpl c) <*> getShadowVersion
-
-    getMainlineVersion = do
-      str <- BC.unpack <$> getByteString 7
-      let mnums = L.filter (not . L.null) $ L.linesBy ('-' ==) str
-      return $ Version (fromMaybe [] $ sequence $ L.map readMaybe mnums) []
-
-    getAzureusImpl    = parseImpl <$> getByteString 2
-    getAzureusVersion = mkVer     <$> getByteString 4
-      where
-        mkVer bs = Version [fromMaybe 0 $ readMaybe $ BC.unpack bs] []
-
-    getBitCometImpl = do
-      bs <- getByteString 3
-      S.lookAhead $ do
-        _  <- getByteString 2
-        lr <- getByteString 4
-        return $
-          if lr == "LORD" then IBitLord  else
-          if bs == "UTB"  then IBitComet else
-          if bs == "xbc"  then IBitComet else def
-
-    getBitCometVersion = do
-      x <- getWord8
-      y <- getWord8
-      return $ Version [fromIntegral x, fromIntegral y] []
-
-    getOperaVersion = do
-      str <- BC.unpack <$> getByteString 4
-      return $ Version [fromMaybe 0 $ readMaybe str] []
-
-    getShadowImpl 'A' = IABC
-    getShadowImpl 'O' = IOspreyPermaseed
-    getShadowImpl 'Q' = IBTQueue
-    getShadowImpl 'R' = ITribler
-    getShadowImpl 'S' = IShadow
-    getShadowImpl 'T' = IBitTornado
-    getShadowImpl  _  = IUnknown
-
-    decodeShadowVerNr :: Char -> Maybe Int
-    decodeShadowVerNr c
-      | '0' < c && c <= '9' = Just  (fromEnum c - fromEnum '0')
-      | 'A' < c && c <= 'Z' = Just ((fromEnum c - fromEnum 'A') + 10)
-      | 'a' < c && c <= 'z' = Just ((fromEnum c - fromEnum 'a') + 36)
-      |        otherwise    = Nothing
-
-    getShadowVersion = do
-      str <- BC.unpack <$> getByteString 5
-      return $ Version (catMaybes $ L.map decodeShadowVerNr str) []
diff --git a/src/Network/BitTorrent/DHT.hs b/src/Network/BitTorrent/DHT.hs
index b6067456..39b33478 100644
--- a/src/Network/BitTorrent/DHT.hs
+++ b/src/Network/BitTorrent/DHT.hs
@@ -63,7 +63,7 @@ import Data.Conduit.List as C
 import Network.Socket
 
 import Data.Torrent
-import Network.BitTorrent.Core
+import Network.BitTorrent.Address
 import Network.BitTorrent.DHT.Query
 import Network.BitTorrent.DHT.Session
 import Network.BitTorrent.DHT.Routing as T
diff --git a/src/Network/BitTorrent/DHT/ContactInfo.hs b/src/Network/BitTorrent/DHT/ContactInfo.hs
index 201b84ee..baa240b4 100644
--- a/src/Network/BitTorrent/DHT/ContactInfo.hs
+++ b/src/Network/BitTorrent/DHT/ContactInfo.hs
@@ -12,13 +12,13 @@ import Data.HashMap.Strict as HM
 import Data.Serialize
 
 import Data.Torrent
-import Network.BitTorrent.Core.PeerAddr
+import Network.BitTorrent.Address
 
 {-
 import Data.HashMap.Strict as HM
 
 import Data.Torrent.InfoHash
-import Network.BitTorrent.Core
+import Network.BitTorrent.Address
 
 -- increase prefix when table is too large
 -- decrease prefix when table is too small
diff --git a/src/Network/BitTorrent/DHT/Message.hs b/src/Network/BitTorrent/DHT/Message.hs
index 06274fa7..145141ee 100644
--- a/src/Network/BitTorrent/DHT/Message.hs
+++ b/src/Network/BitTorrent/DHT/Message.hs
@@ -93,7 +93,7 @@ import Network
 import Network.KRPC
 
 import Data.Torrent
-import Network.BitTorrent.Core
+import Network.BitTorrent.Address
 import Network.BitTorrent.DHT.Token
 import Network.KRPC ()
 
diff --git a/src/Network/BitTorrent/DHT/Query.hs b/src/Network/BitTorrent/DHT/Query.hs
index 497c9001..d4710ecf 100644
--- a/src/Network/BitTorrent/DHT/Query.hs
+++ b/src/Network/BitTorrent/DHT/Query.hs
@@ -57,7 +57,7 @@ import Text.PrettyPrint.Class
 
 import Network.KRPC hiding (Options, def)
 import Data.Torrent
-import Network.BitTorrent.Core
+import Network.BitTorrent.Address
 import Network.BitTorrent.DHT.Message
 import Network.BitTorrent.DHT.Routing
 import Network.BitTorrent.DHT.Session
diff --git a/src/Network/BitTorrent/DHT/Routing.hs b/src/Network/BitTorrent/DHT/Routing.hs
index 5dc511bd..ee295125 100644
--- a/src/Network/BitTorrent/DHT/Routing.hs
+++ b/src/Network/BitTorrent/DHT/Routing.hs
@@ -74,7 +74,7 @@ import Text.PrettyPrint as PP hiding ((<>))
 import Text.PrettyPrint.Class
 
 import Data.Torrent
-import Network.BitTorrent.Core
+import Network.BitTorrent.Address
 
 {-----------------------------------------------------------------------
 --  Routing monad
diff --git a/src/Network/BitTorrent/DHT/Session.hs b/src/Network/BitTorrent/DHT/Session.hs
index 8fe81abd..0dd4b862 100644
--- a/src/Network/BitTorrent/DHT/Session.hs
+++ b/src/Network/BitTorrent/DHT/Session.hs
@@ -94,8 +94,7 @@ import Text.PrettyPrint.Class
 import Data.Torrent as Torrent
 import Network.KRPC hiding (Options, def)
 import qualified Network.KRPC as KRPC (def)
-import Network.BitTorrent.Core
-import Network.BitTorrent.Core.PeerAddr
+import Network.BitTorrent.Address
 import Network.BitTorrent.DHT.ContactInfo as P
 import Network.BitTorrent.DHT.Message
 import Network.BitTorrent.DHT.Routing as R
diff --git a/src/Network/BitTorrent/DHT/Token.hs b/src/Network/BitTorrent/DHT/Token.hs
index a38456fd..a0ed428b 100644
--- a/src/Network/BitTorrent/DHT/Token.hs
+++ b/src/Network/BitTorrent/DHT/Token.hs
@@ -50,7 +50,7 @@ import Data.String
 import Data.Time
 import System.Random
 
-import Network.BitTorrent.Core
+import Network.BitTorrent.Address
 
 -- TODO use ShortByteString
 
diff --git a/src/Network/BitTorrent/Exchange/Assembler.hs b/src/Network/BitTorrent/Exchange/Assembler.hs
index e17dfbe2..7abb8ab0 100644
--- a/src/Network/BitTorrent/Exchange/Assembler.hs
+++ b/src/Network/BitTorrent/Exchange/Assembler.hs
@@ -68,7 +68,7 @@ import Data.Maybe
 import Data.IP
 
 import Data.Torrent
-import Network.BitTorrent.Core
+import Network.BitTorrent.Address
 import Network.BitTorrent.Exchange.Block as B
 
 {-----------------------------------------------------------------------
diff --git a/src/Network/BitTorrent/Exchange/Connection.hs b/src/Network/BitTorrent/Exchange/Connection.hs
index 42b991a0..9b7942ae 100644
--- a/src/Network/BitTorrent/Exchange/Connection.hs
+++ b/src/Network/BitTorrent/Exchange/Connection.hs
@@ -137,7 +137,7 @@ import System.Timeout
 
 import Data.Torrent.Bitfield as BF
 import Data.Torrent
-import Network.BitTorrent.Core
+import Network.BitTorrent.Address
 import Network.BitTorrent.Exchange.Message as Msg
 
 -- TODO handle port message?
diff --git a/src/Network/BitTorrent/Exchange/Manager.hs b/src/Network/BitTorrent/Exchange/Manager.hs
index ad7a47a2..54727805 100644
--- a/src/Network/BitTorrent/Exchange/Manager.hs
+++ b/src/Network/BitTorrent/Exchange/Manager.hs
@@ -13,7 +13,7 @@ import Data.Default
 import Network.Socket
 
 import Data.Torrent
-import Network.BitTorrent.Core
+import Network.BitTorrent.Address
 import Network.BitTorrent.Exchange.Connection hiding (Options)
 import Network.BitTorrent.Exchange.Session
 
diff --git a/src/Network/BitTorrent/Exchange/Message.hs b/src/Network/BitTorrent/Exchange/Message.hs
index 5ca7c97e..a0cb5c91 100644
--- a/src/Network/BitTorrent/Exchange/Message.hs
+++ b/src/Network/BitTorrent/Exchange/Message.hs
@@ -120,7 +120,7 @@ import Text.PrettyPrint.Class
 import Data.Torrent.Bitfield
 import Data.Torrent hiding (Piece (..))
 import qualified Data.Torrent as P (Piece (..))
-import Network.BitTorrent.Core
+import Network.BitTorrent.Address
 import Network.BitTorrent.Exchange.Block
 
 {-----------------------------------------------------------------------
diff --git a/src/Network/BitTorrent/Exchange/Session.hs b/src/Network/BitTorrent/Exchange/Session.hs
index cae3a2d5..b68f17a0 100644
--- a/src/Network/BitTorrent/Exchange/Session.hs
+++ b/src/Network/BitTorrent/Exchange/Session.hs
@@ -48,7 +48,7 @@ import Data.BEncode as BE
 import Data.Torrent as Torrent
 import Data.Torrent.Bitfield as BF
 import Network.BitTorrent.Internal.Types
-import Network.BitTorrent.Core
+import Network.BitTorrent.Address
 import Network.BitTorrent.Exchange.Block   as Block
 import Network.BitTorrent.Exchange.Connection
 import Network.BitTorrent.Exchange.Message as Message
diff --git a/src/Network/BitTorrent/Exchange/Session/Metadata.hs b/src/Network/BitTorrent/Exchange/Session/Metadata.hs
index a4e54659..f08ebe00 100644
--- a/src/Network/BitTorrent/Exchange/Session/Metadata.hs
+++ b/src/Network/BitTorrent/Exchange/Session/Metadata.hs
@@ -27,7 +27,7 @@ import Data.Tuple
 
 import Data.BEncode as BE
 import Data.Torrent as Torrent
-import Network.BitTorrent.Core
+import Network.BitTorrent.Address
 import Network.BitTorrent.Exchange.Block   as Block
 import Network.BitTorrent.Exchange.Message as Message hiding (Status)
 
diff --git a/src/Network/BitTorrent/Exchange/Session/Status.hs b/src/Network/BitTorrent/Exchange/Session/Status.hs
index 4feff8d6..63b91926 100644
--- a/src/Network/BitTorrent/Exchange/Session/Status.hs
+++ b/src/Network/BitTorrent/Exchange/Session/Status.hs
@@ -30,7 +30,7 @@ import Data.Tuple
 
 import Data.Torrent
 import Data.Torrent.Bitfield as BF
-import Network.BitTorrent.Core
+import Network.BitTorrent.Address
 import Network.BitTorrent.Exchange.Block as Block
 import System.Torrent.Storage (Storage, writePiece)
 
diff --git a/src/Network/BitTorrent/Tracker/Message.hs b/src/Network/BitTorrent/Tracker/Message.hs
index e58f6d70..d251d0ad 100644
--- a/src/Network/BitTorrent/Tracker/Message.hs
+++ b/src/Network/BitTorrent/Tracker/Message.hs
@@ -126,7 +126,7 @@ import Text.Read (readMaybe)
 
 import Data.Torrent
 import Data.Torrent.Progress
-import Network.BitTorrent.Core
+import Network.BitTorrent.Address
 
 
 {-----------------------------------------------------------------------
diff --git a/src/Network/BitTorrent/Tracker/RPC.hs b/src/Network/BitTorrent/Tracker/RPC.hs
index 9148f1f5..ecb1001c 100644
--- a/src/Network/BitTorrent/Tracker/RPC.hs
+++ b/src/Network/BitTorrent/Tracker/RPC.hs
@@ -38,7 +38,7 @@ import Network.Socket (HostAddress)
 
 import           Data.Torrent
 import           Data.Torrent.Progress
-import           Network.BitTorrent.Core
+import           Network.BitTorrent.Address
 import           Network.BitTorrent.Tracker.Message
 import qualified Network.BitTorrent.Tracker.RPC.HTTP as HTTP
 import qualified Network.BitTorrent.Tracker.RPC.UDP  as UDP
diff --git a/src/Network/BitTorrent/Tracker/RPC/HTTP.hs b/src/Network/BitTorrent/Tracker/RPC/HTTP.hs
index b4924e6d..6e55eb04 100644
--- a/src/Network/BitTorrent/Tracker/RPC/HTTP.hs
+++ b/src/Network/BitTorrent/Tracker/RPC/HTTP.hs
@@ -48,7 +48,7 @@ import           Network.HTTP.Types.Header (hUserAgent)
 import           Network.HTTP.Types.URI    (SimpleQuery, renderSimpleQuery)
 
 import Data.Torrent                        (InfoHash)
-import Network.BitTorrent.Core.Fingerprint (libUserAgent)
+import Network.BitTorrent.Address             (libUserAgent)
 import Network.BitTorrent.Tracker.Message hiding (Request, Response)
 
 {-----------------------------------------------------------------------
diff --git a/src/Network/BitTorrent/Tracker/Session.hs b/src/Network/BitTorrent/Tracker/Session.hs
index 35db459f..cef7d665 100644
--- a/src/Network/BitTorrent/Tracker/Session.hs
+++ b/src/Network/BitTorrent/Tracker/Session.hs
@@ -58,7 +58,7 @@ import Data.Traversable
 import Network.URI
 
 import Data.Torrent
-import Network.BitTorrent.Core
+import Network.BitTorrent.Address
 import Network.BitTorrent.Internal.Cache
 import Network.BitTorrent.Internal.Types
 import Network.BitTorrent.Tracker.List as TL