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module Network (
Peer(..),
PeerAddress,
peerDiscovery,
) where
import Control.Concurrent
import Control.Exception
import Control.Monad
import Control.Monad.Except
import qualified Data.ByteString.Char8 as BC
import qualified Data.ByteString.Lazy as BL
import qualified Data.Map as M
import qualified Data.Text as T
import Network.Socket
import Network.Socket.ByteString (recvFrom, sendTo)
import Channel
import Identity
import PubKey
import Storage
discoveryPort :: ServiceName
discoveryPort = "29665"
data Peer = Peer
{ peerAddress :: PeerAddress
, peerIdentity :: Maybe (Stored Identity)
, peerChannels :: [Channel]
}
deriving (Show)
data PeerAddress = DatagramAddress SockAddr
deriving (Show)
data TransportHeader = AnnouncePacket Ref
| IdentityRequest Ref Ref
| IdentityResponse Ref
| TrChannelRequest Ref
| TrChannelAccept Ref
transportToObject :: TransportHeader -> Object
transportToObject = \case
AnnouncePacket ref -> Rec
[ (BC.pack "TRANS", RecText $ T.pack "announce")
, (BC.pack "identity", RecRef ref)
]
IdentityRequest ref from -> Rec
[ (BC.pack "TRANS", RecText $ T.pack "idreq")
, (BC.pack "identity", RecRef ref)
, (BC.pack "from", RecRef from)
]
IdentityResponse ref -> Rec
[ (BC.pack "TRANS", RecText $ T.pack "idresp")
, (BC.pack "identity", RecRef ref)
]
TrChannelRequest ref -> Rec
[ (BC.pack "TRANS", RecText $ T.pack "chreq")
, (BC.pack "req", RecRef ref)
]
TrChannelAccept ref -> Rec
[ (BC.pack "TRANS", RecText $ T.pack "chacc")
, (BC.pack "acc", RecRef ref)
]
transportFromObject :: Object -> Maybe TransportHeader
transportFromObject (Rec items)
| Just (RecText trans) <- lookup (BC.pack "TRANS") items, trans == T.pack "announce"
, Just (RecRef ref) <- lookup (BC.pack "identity") items
= Just $ AnnouncePacket ref
| Just (RecText trans) <- lookup (BC.pack "TRANS") items, trans == T.pack "idreq"
, Just (RecRef ref) <- lookup (BC.pack "identity") items
, Just (RecRef from) <- lookup (BC.pack "from") items
= Just $ IdentityRequest ref from
| Just (RecText trans) <- lookup (BC.pack "TRANS") items, trans == T.pack "idresp"
, Just (RecRef ref) <- lookup (BC.pack "identity") items
= Just $ IdentityResponse ref
| Just (RecText trans) <- lookup (BC.pack "TRANS") items, trans == T.pack "chreq"
, Just (RecRef ref) <- lookup (BC.pack "req") items
= Just $ TrChannelRequest ref
| Just (RecText trans) <- lookup (BC.pack "TRANS") items, trans == T.pack "chacc"
, Just (RecRef ref) <- lookup (BC.pack "acc") items
= Just $ TrChannelAccept ref
transportFromObject _ = Nothing
peerDiscovery :: String -> Stored Identity -> IO (Chan Peer)
peerDiscovery bhost sidentity = do
chanPeer <- newChan
peers <- newMVar M.empty
let open addr = do
sock <- socket (addrFamily addr) (addrSocketType addr) (addrProtocol addr)
setSocketOption sock ReuseAddr 1
setSocketOption sock Broadcast 1
setCloseOnExecIfNeeded =<< fdSocket sock
bind sock (addrAddress addr)
return sock
loop sock = do
baddr:_ <- getAddrInfo (Just $ defaultHints { addrSocketType = Datagram }) (Just bhost) (Just discoveryPort)
void $ sendTo sock (BL.toStrict $ serializeObject $ transportToObject $ AnnouncePacket $ storedRef sidentity) (addrAddress baddr)
forever $ do
(msg, paddr) <- recvFrom sock 4096
let packet' = packet sock paddr
case runExcept $ deserializeObjects (storedStorage sidentity) $ BL.fromStrict msg of
Left err -> putStrLn $ show paddr ++ ": " ++ err
Right (obj:objs) | Just tpack <- transportFromObject obj -> packet' tpack objs
_ -> putStrLn $ show paddr ++ ": invalid transport packet"
packet sock paddr (AnnouncePacket ref) _ = do
putStrLn $ "Got announce: " ++ show ref ++ " from " ++ show paddr
when (ref /= storedRef sidentity) $ void $ sendTo sock (BL.toStrict $ BL.concat
[ serializeObject $ transportToObject $ IdentityRequest ref (storedRef sidentity)
, BL.concat $ map (lazyLoadBytes . storedRef) $ collectStoredObjects $ wrappedLoad $ storedRef sidentity
]) paddr
packet _ paddr (IdentityRequest ref from) [] = do
putStrLn $ "Got identity request: for " ++ show ref ++ " by " ++ show from ++ " from " ++ show paddr ++ " without content"
packet sock paddr (IdentityRequest ref from) (obj:objs) = do
putStrLn $ "Got identity request: for " ++ show ref ++ " by " ++ show from ++ " from " ++ show paddr
print (obj:objs)
from' <- store (storedStorage sidentity) obj
if from == from'
then do forM_ objs $ store $ storedStorage sidentity
let peer = Peer (DatagramAddress paddr) (Just $ wrappedLoad from) []
modifyMVar_ peers $ return . M.insert paddr peer
writeChan chanPeer peer
void $ sendTo sock (BL.toStrict $ BL.concat
[ serializeObject $ transportToObject $ IdentityResponse (storedRef sidentity)
, BL.concat $ map (lazyLoadBytes . storedRef) $ collectStoredObjects $ wrappedLoad $ storedRef sidentity
]) paddr
else putStrLn $ "Mismatched content"
packet _ paddr (IdentityResponse ref) [] = do
putStrLn $ "Got identity response: by " ++ show ref ++ " from " ++ show paddr ++ " without content"
packet sock paddr (IdentityResponse ref) (obj:objs) = do
putStrLn $ "Got identity response: by " ++ show ref ++ " from " ++ show paddr
print (obj:objs)
ref' <- store (storedStorage sidentity) obj
if ref == ref'
then do forM_ objs $ store $ storedStorage sidentity
let pidentity = wrappedLoad ref
peer = Peer (DatagramAddress paddr) (Just pidentity) []
modifyMVar_ peers $ return . M.insert paddr peer
writeChan chanPeer peer
req <- createChannelRequest sidentity pidentity
void $ sendTo sock (BL.toStrict $ BL.concat
[ serializeObject $ transportToObject $ TrChannelRequest (storedRef req)
, lazyLoadBytes $ storedRef req
, lazyLoadBytes $ storedRef $ signedData $ fromStored req
, lazyLoadBytes $ storedRef $ crKey $ fromStored $ signedData $ fromStored req
, BL.concat $ map (lazyLoadBytes . storedRef) $ signedSignature $ fromStored req
]) paddr
else putStrLn $ "Mismatched content"
packet _ paddr (TrChannelRequest _) [] = do
putStrLn $ "Got channel request: from " ++ show paddr ++ " without content"
packet sock paddr (TrChannelRequest ref) (obj:objs) = do
putStrLn $ "Got channel request: from " ++ show paddr
print (obj:objs)
ref' <- store (storedStorage sidentity) obj
if ref == ref'
then do forM_ objs $ store $ storedStorage sidentity
let request = wrappedLoad ref :: Stored ChannelRequest
modifyMVar_ peers $ \pval -> case M.lookup paddr pval of
Just peer | Just pid <- peerIdentity peer ->
runExceptT (acceptChannelRequest sidentity pid request) >>= \case
Left errs -> do mapM_ putStrLn ("Invalid channel request" : errs)
return pval
Right (acc, channel) -> do
putStrLn $ "Got channel: " ++ show (storedRef channel)
let peer' = peer { peerChannels = fromStored channel : peerChannels peer }
writeChan chanPeer peer'
void $ sendTo sock (BL.toStrict $ BL.concat
[ serializeObject $ transportToObject $ TrChannelAccept (storedRef acc)
, lazyLoadBytes $ storedRef acc
, lazyLoadBytes $ storedRef $ signedData $ fromStored acc
, lazyLoadBytes $ storedRef $ caKey $ fromStored $ signedData $ fromStored acc
, BL.concat $ map (lazyLoadBytes . storedRef) $ signedSignature $ fromStored acc
]) paddr
return $ M.insert paddr peer' pval
_ -> do putStrLn $ "Invalid channel request - no peer identity"
return pval
else putStrLn $ "Mismatched content"
packet _ paddr (TrChannelAccept _) [] = do
putStrLn $ "Got channel accept: from " ++ show paddr ++ " without content"
packet _ paddr (TrChannelAccept ref) (obj:objs) = do
putStrLn $ "Got channel accept: from " ++ show paddr
print (obj:objs)
ref' <- store (storedStorage sidentity) obj
if ref == ref'
then do forM_ objs $ store $ storedStorage sidentity
let accepted = wrappedLoad ref :: Stored ChannelAccept
modifyMVar_ peers $ \pval -> case M.lookup paddr pval of
Just peer | Just pid <- peerIdentity peer ->
runExceptT (acceptedChannel sidentity pid accepted) >>= \case
Left errs -> do mapM_ putStrLn ("Invalid channel accept" : errs)
return pval
Right channel -> do
putStrLn $ "Got channel: " ++ show (storedRef channel)
let peer' = peer { peerChannels = fromStored channel : peerChannels peer }
writeChan chanPeer peer'
return $ M.insert paddr peer' pval
_ -> do putStrLn $ "Invalid channel accept - no peer identity"
return pval
else putStrLn $ "Mismatched content"
void $ forkIO $ withSocketsDo $ do
let hints = defaultHints
{ addrFlags = [AI_PASSIVE]
, addrSocketType = Datagram
}
addr:_ <- getAddrInfo (Just hints) Nothing (Just discoveryPort)
bracket (open addr) close loop
return chanPeer
|