1 {-# LANGUAGE OverloadedStrings #-}
3 Copyright (C) 2015-2016 Ramakrishnan Muthukrishnan <ram@rkrishnan.org>
5 This file is part of FuncTorrent.
7 FuncTorrent is free software; you can redistribute it and/or modify
8 it under the terms of the GNU General Public License as published by
9 the Free Software Foundation; either version 3 of the License, or
10 (at your option) any later version.
12 FuncTorrent is distributed in the hope that it will be useful,
13 but WITHOUT ANY WARRANTY; without even the implied warranty of
14 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15 GNU General Public License for more details.
17 You should have received a copy of the GNU General Public License
18 along with FuncTorrent; if not, see <http://www.gnu.org/licenses/>
21 module FuncTorrent.Tracker.Http
25 import Prelude hiding (lookup, splitAt)
27 import Control.Concurrent (threadDelay)
28 import Control.Concurrent.MVar (readMVar, putMVar)
29 import Control.Monad (forever)
30 import qualified Data.ByteString.Base16 as B16 (encode)
31 import Data.ByteString (ByteString)
32 import Data.ByteString.Char8 as BC (pack, unpack, splitAt)
33 import Data.Char (chr)
34 import Data.List (intercalate)
35 import Data.Map as M (lookup)
36 import Network (PortNumber)
37 import Network.HTTP.Base (urlEncode)
39 import qualified FuncTorrent.Bencode as Benc
40 import FuncTorrent.Bencode (BVal(..))
41 import qualified FuncTorrent.FileSystem as FS (MsgChannel, Stats(..), getStats)
42 import FuncTorrent.Network (sendGetRequest)
43 import FuncTorrent.Peer (Peer(..))
44 import FuncTorrent.Utils (splitN)
45 import FuncTorrent.Tracker.Types(TState(..), TrackerResponse(..), Port, IP)
48 --- | URL encode hash as per RFC1738
50 --- REVIEW: Why is this not written in terms of `Network.HTTP.Base.urlEncode` or
51 --- equivalent library function?
52 urlEncodeHash :: ByteString -> String
53 urlEncodeHash bs = concatMap (encode' . unpack) (splitN 2 bs)
54 where encode' b@[c1, c2] = let c = chr (read ("0x" ++ b))
57 escape i c1 c2 | i `elem` nonSpecialChars = [i]
58 | otherwise = "%" ++ [c1] ++ [c2]
60 nonSpecialChars = ['A'..'Z'] ++ ['a'..'z'] ++ ['0'..'9'] ++ "-_.~"
62 -- | Make arguments that should be posted to tracker.
63 -- This is a separate pure function for testability.
64 mkArgs :: PortNumber -> String -> Integer -> Integer -> Integer -> ByteString -> [(String, ByteString)]
65 mkArgs port peer_id up down left' infoHash =
66 [("info_hash", pack . urlEncodeHash . B16.encode $ infoHash),
67 ("peer_id", pack . urlEncode $ peer_id),
68 ("port", pack $ show port),
69 ("uploaded", pack $ show up),
70 ("downloaded", pack $ show down),
71 ("left", pack $ show left'),
75 trackerLoop :: String -> PortNumber -> String -> ByteString -> FS.MsgChannel -> TState -> IO ()
76 trackerLoop url port peerId infohash fschan tstate = forever $ do
77 st' <- FS.getStats fschan
79 let up = FS.bytesRead st
80 down = FS.bytesWritten st
81 resp <- sendGetRequest url $ mkArgs port peerId up down (left tstate) infohash
82 case Benc.decode resp of
83 Left e -> return () -- $ pack (show e)
85 case parseTrackerResponse trackerInfo of
86 Left e -> return () -- e
88 _ <- threadDelay $ fromIntegral (interval tresp)
89 _ <- putMVar (connectedPeers tstate) (peers tresp)
90 return () -- trackerLoop port peerId st
92 parseTrackerResponse :: BVal -> Either ByteString TrackerResponse
93 parseTrackerResponse resp =
94 case lookup "failure reason" body of
95 Just (Bstr err) -> Left err
96 Just _ -> Left "Unknown failure"
98 let (Just (Bint i)) = lookup "interval" body
99 (Just (Bstr peersBS)) = lookup "peers" body
100 pl = map makePeer (splitN 6 peersBS)
101 in Right TrackerResponse {
105 , incomplete = Nothing
110 makePeer :: ByteString -> Peer
111 makePeer peer = Peer "" (toIP ip') (toPort port')
112 where (ip', port') = splitAt 4 peer
114 toPort :: ByteString -> Port
115 toPort = read . ("0x" ++) . unpack . B16.encode
117 toIP :: ByteString -> IP
118 toIP = Data.List.intercalate "." .
119 map (show . toInt . ("0x" ++) . unpack) .
120 splitN 2 . B16.encode
122 toInt :: String -> Integer