urbit/pkg/hs/urbit-king/lib/Urbit/Vere/Ames.hs
2020-08-14 16:17:47 -04:00

253 lines
7.5 KiB
Haskell

{-|
Ames IO Driver
-}
module Urbit.Vere.Ames (ames, ames', PacketOutcome(..)) where
import Urbit.Prelude
import Network.Socket hiding (recvFrom, sendTo)
import Urbit.Arvo hiding (Fake)
import Urbit.King.Config
import Urbit.Vere.Pier.Types
import Urbit.Vere.Ports
import Urbit.King.App (HasKingId(..), HasPierEnv(..))
import Urbit.Vere.Ames.DNS (NetworkMode(..), ResolvServ(..))
import Urbit.Vere.Ames.DNS (galaxyPort, resolvServ)
import Urbit.Vere.Ames.UDP (UdpServ(..), fakeUdpServ, realUdpServ)
-- Constants -------------------------------------------------------------------
-- | How many unprocessed ames packets to allow in the queue before we start
-- dropping incoming packets.
queueBound :: Word
queueBound = 1000
-- | How often, measured in number of packets dropped, we should announce packet
-- loss.
packetsDroppedPerComplaint :: Word
packetsDroppedPerComplaint = 1000
-- Types -----------------------------------------------------------------------
data AmesDrv = AmesDrv
{ aTurfs :: TVar (Maybe [Turf])
, aDropped :: TVar Word
, aUdpServ :: UdpServ
, aResolvr :: ResolvServ
, aRecvTid :: Async ()
}
data PacketOutcome
= Intake
| Ouster
-- Utils -----------------------------------------------------------------------
listenPort :: NetworkMode -> Ship -> PortNumber
listenPort m s | s < 256 = galaxyPort m (fromIntegral s)
listenPort m _ = 0 -- I don't care, just give me any port.
localhost :: HostAddress
localhost = tupleToHostAddress (127, 0, 0, 1)
inaddrAny :: HostAddress
inaddrAny = tupleToHostAddress (0, 0, 0, 0)
modeAddress :: NetworkMode -> Maybe HostAddress
modeAddress = \case
Fake -> Just localhost
Localhost -> Just localhost
Real -> Just inaddrAny
NoNetwork -> Nothing
okFakeAddr :: AmesDest -> Bool
okFakeAddr = \case
EachYes _ -> True
EachNo (Jammed (AAIpv4 (Ipv4 a) _)) -> a == localhost
EachNo (Jammed (AAVoid v )) -> absurd v
localAddr :: NetworkMode -> AmesDest -> SockAddr
localAddr mode = \case
EachYes g -> SockAddrInet (galaxyPort mode g) localhost
EachNo (Jammed (AAIpv4 _ p)) -> SockAddrInet (fromIntegral p) localhost
EachNo (Jammed (AAVoid v )) -> absurd v
bornEv :: KingId -> Ev
bornEv inst = EvBlip $ BlipEvNewt $ NewtEvBorn (fromIntegral inst, ()) ()
hearEv :: PortNumber -> HostAddress -> ByteString -> Ev
hearEv p a bs =
EvBlip $ BlipEvAmes $ AmesEvHear () dest (MkBytes bs)
where
dest = EachNo $ Jammed $ AAIpv4 (Ipv4 a) (fromIntegral p)
--------------------------------------------------------------------------------
netMode :: HasNetworkConfig e => Bool -> RIO e NetworkMode
netMode isFake = do
netMode <- view (networkConfigL . ncNetMode)
noAmes <- view (networkConfigL . ncNoAmes)
pure $ case (noAmes, isFake, netMode) of
(True, _ , _ ) -> NoNetwork
(_ , _ , NMNone ) -> NoNetwork
(_ , True, _ ) -> Fake
(_ , _ , NMNormal ) -> Real
(_ , _ , NMLocalhost) -> Localhost
udpPort :: HasNetworkConfig e => Bool -> Ship -> RIO e PortNumber
udpPort isFake who = do
mode <- netMode isFake
mPort <- view (networkConfigL . ncAmesPort)
pure $ maybe (listenPort mode who) fromIntegral mPort
udpServ :: (HasLogFunc e, HasNetworkConfig e, HasPortControlApi e)
=> Bool
-> Ship
-> RIO e UdpServ
udpServ isFake who = do
mode <- netMode isFake
port <- udpPort isFake who
case modeAddress mode of
Nothing -> fakeUdpServ
Just host -> realUdpServ port host
_bornFailed :: e -> WorkError -> IO ()
_bornFailed env _ = runRIO env $ do
pure () -- TODO What can we do?
ames'
:: HasPierEnv e
=> Ship
-> Bool
-> (Text -> RIO e ())
-> RIO e ([Ev], RAcquire e (DriverApi NewtEf))
ames' who isFake stderr = do
-- Unfortunately, we cannot use TBQueue because the only behavior
-- provided for when full is to block the writer. The implementation
-- below uses materially the same data structures as TBQueue, however.
ventQ :: TQueue EvErr <- newTQueueIO
avail :: TVar Word <- newTVarIO queueBound
let
enqueuePacket p = do
vail <- readTVar avail
if vail > 0
then do
modifyTVar avail (subtract 1)
writeTQueue ventQ p
pure Intake
else do
_ <- readTQueue ventQ
writeTQueue ventQ p
pure Ouster
dequeuePacket = do
pM <- tryReadTQueue ventQ
when (isJust pM) $ modifyTVar avail (+ 1)
pure pM
env <- ask
let (bornEvs, startDriver) = ames env who isFake enqueuePacket stderr
let runDriver = do
diOnEffect <- startDriver
let diEventSource = fmap RRWork <$> dequeuePacket
pure (DriverApi {..})
pure (bornEvs, runDriver)
{-|
inst -- Process instance number.
who -- Which ship are we?
enqueueEv -- Queue-event action.
mPort -- Explicit port override from command line arguments.
4096 is a reasonable number for recvFrom. Packets of that size are
not possible on the internet.
TODO verify that the KingIds match on effects.
-}
ames
:: forall e
. (HasLogFunc e, HasNetworkConfig e, HasPortControlApi e, HasKingId e)
=> e
-> Ship
-> Bool
-> (EvErr -> STM PacketOutcome)
-> (Text -> RIO e ())
-> ([Ev], RAcquire e (NewtEf -> IO ()))
ames env who isFake enqueueEv stderr = (initialEvents, runAmes)
where
king = fromIntegral (env ^. kingIdL)
initialEvents :: [Ev]
initialEvents = [bornEv king]
runAmes :: RAcquire e (NewtEf -> IO ())
runAmes = do
mode <- rio (netMode isFake)
drv <- mkRAcquire start stop
pure (handleEffect drv mode)
start :: HasLogFunc e => RIO e AmesDrv
start = do
aTurfs <- newTVarIO Nothing
aDropped <- newTVarIO 0
aUdpServ <- udpServ isFake who
aRecvTid <- queuePacketsThread aDropped aUdpServ
aResolvr <- resolvServ aTurfs (usSend aUdpServ) stderr
pure (AmesDrv { .. })
hearFailed _ = pure ()
queuePacketsThread :: HasLogFunc e => TVar Word -> UdpServ -> RIO e (Async ())
queuePacketsThread dropCtr UdpServ {..} = async $ forever $ do
outcome <- atomically $ do
(p, a, b) <- usRecv
enqueueEv (EvErr (hearEv p a b) hearFailed)
case outcome of
Intake -> pure ()
Ouster -> do
d <- atomically $ do
d <- readTVar dropCtr
writeTVar dropCtr (d + 1)
pure d
when (d `rem` packetsDroppedPerComplaint == 0) $
logWarn "ames: queue full; dropping inbound packets"
stop :: AmesDrv -> RIO e ()
stop AmesDrv {..} = io $ do
usKill aUdpServ
rsKill aResolvr
cancel aRecvTid
handleEffect :: AmesDrv -> NetworkMode -> NewtEf -> IO ()
handleEffect drv@AmesDrv {..} mode = runRIO env . \case
NewtEfTurf (_id, ()) turfs -> do
atomically $ writeTVar aTurfs (Just turfs)
NewtEfSend (_id, ()) dest (MkBytes bs) -> do
atomically (readTVar aTurfs) >>= \case
Nothing -> stderr "ames: send before turfs" >> pure ()
Just turfs -> sendPacket drv mode dest bs
sendPacket :: AmesDrv -> NetworkMode -> AmesDest -> ByteString -> RIO e ()
sendPacket AmesDrv {..} mode dest byt = do
let to adr = io (usSend aUdpServ adr byt)
case (mode, dest) of
(NoNetwork, _ ) -> pure ()
(Fake , _ ) -> when (okFakeAddr dest) $ to (localAddr Fake dest)
(Localhost, _ ) -> to (localAddr Localhost dest)
(Real , ra) -> ra & \case
EachYes gala -> io (rsSend aResolvr gala byt)
EachNo addr -> to (ipv4Addr addr)
ipv4Addr (Jammed (AAVoid v )) = absurd v
ipv4Addr (Jammed (AAIpv4 a p)) = SockAddrInet (fromIntegral p) (unIpv4 a)