basic PEX

has glitches; it's needed to determine when same
peer shows up under different address (like in case of
NAT)

docs/devlog.md

@@ -1,6 +1,30 @@
 
 ## 2023-02-06
 
+Ну а так, базовый PEX заработал
+
+TODO:   Добавлять пиров в KnownPeers
+        только после того, как они
+        пинганулись.  Т.е пинговать
+        пиров, если их еще нет.
+        Не добавлять в KnownPeers до
+        того, как ответили на пинг.
+
+TODO:   Научиться убирать дубликаты пиров.
+        Их можно распознать по PeerNonce,
+        но непонятно, какой из пиров
+        оставлять.
+        Иначе это будет реально большая
+        проблема при скачивании.
+
+
+TODO:   Убедиться, что subscribe на перманентное
+        событие НИКОГДА не вызывается в рекурсии.
+        Проверить ВСЕ subscribe.
+        Возможно, вставить проверки в рантайм.
+        Возможно, ограничить число таких событий
+        и ругаться в рантайме.
+
 FIXME:  При вычислении burst надо каким-то образом
         находить плато и не лезть выше него.
 

hbs2-core/hbs2-core.cabal

@@ -91,6 +91,7 @@ library
                     , HBS2.Net.Proto.Definition
                     , HBS2.Net.Proto.Peer
                     , HBS2.Net.Proto.PeerAnnounce
+                    , HBS2.Net.Proto.PeerExchange
                     , HBS2.Net.Proto.Sessions
                     , HBS2.Net.Proto.Types
                     , HBS2.OrDie

hbs2-core/lib/HBS2/Actors/Peer.hs

@@ -57,9 +57,6 @@ data AnyMessage enc e = AnyMessage !Integer !(Encoded e)
 class Monad m => HasOwnPeer e m where
   ownPeer :: m (Peer e)
 
-class Monad m => HasPeerLocator e m where
-  getPeerLocator ::  m (AnyPeerLocator e)
-
 class HasStorage m where
   getStorage :: m AnyStorage
 
@@ -464,4 +461,6 @@ instance (Monad m, HasFabriq e m) => HasFabriq e (ResponseM e m) where
 instance (Monad m, HasPeerNonce e m) => HasPeerNonce e (ResponseM e m) where
   peerNonce = lift $ peerNonce @e
 
+instance (Monad m, HasPeerLocator e m) => HasPeerLocator e (ResponseM e m) where
+  getPeerLocator = lift getPeerLocator
 

hbs2-core/lib/HBS2/Defaults.hs

@@ -70,5 +70,8 @@ defSweepTimeout = 30 -- FIXME: only for debug!
 defPeerAnnounceTime :: Timeout 'Seconds
 defPeerAnnounceTime = 120
 
+defPexMaxPeers :: Int
+defPexMaxPeers = 50
+
 
 

hbs2-core/lib/HBS2/Net/PeerLocator.hs

@@ -4,10 +4,14 @@ module HBS2.Net.PeerLocator where
 import HBS2.Prelude
 import HBS2.Net.Proto.Types
 
+import System.Random.Shuffle (shuffleM)
+
 class PeerLocator e l where
   knownPeers   :: forall m . (HasPeer e, MonadIO m) => l -> m [Peer e]
   addPeers     :: forall m . (HasPeer e, MonadIO m) => l -> [Peer e] -> m ()
   delPeers     :: forall m . (HasPeer e, MonadIO m) => l -> [Peer e] -> m ()
+  bestPeers    :: forall m . (HasPeer e, MonadIO m) => l -> m [Peer e]
+  addExcluded  :: forall m . (HasPeer e, MonadIO m) => l -> [Peer e] -> m ()
 
 data AnyPeerLocator e = forall a . PeerLocator e a => AnyPeerLocator a
 
@@ -15,5 +19,10 @@ instance HasPeer e => PeerLocator e (AnyPeerLocator e) where
   knownPeers (AnyPeerLocator l) = knownPeers  l
   addPeers (AnyPeerLocator l) = addPeers l
   delPeers (AnyPeerLocator l) = delPeers l
+  addExcluded (AnyPeerLocator l) = addExcluded l
 
+  -- FIXME: a better algorithm of choice
+  bestPeers (AnyPeerLocator l) = liftIO $ knownPeers l >>= shuffleM
 
+class Monad m => HasPeerLocator e m where
+  getPeerLocator ::  m (AnyPeerLocator e)

hbs2-core/lib/HBS2/Net/PeerLocator/Static.hs

@@ -1,4 +1,8 @@
-module HBS2.Net.PeerLocator.Static where
+module HBS2.Net.PeerLocator.Static
+  ( StaticPeerLocator
+  , newStaticPeerLocator
+  , PeerLocator()
+  ) where
 
 import HBS2.Prelude
 import HBS2.Net.Proto
@@ -8,27 +12,36 @@ import Control.Concurrent.STM
 import Data.Set (Set)
 import Data.Set qualified as Set
 
-import Prettyprinter
 
-newtype StaticPeerLocator e =
+data StaticPeerLocator e =
-  StaticPeerLocator (TVar (Set (Peer e)))
+  StaticPeerLocator
+  { include :: TVar (Set (Peer e))
+  , exclude :: TVar (Set (Peer e))
+  }
 
 
 newStaticPeerLocator :: (Ord (Peer p), HasPeer p, MonadIO m) => [Peer p] -> m (StaticPeerLocator p)
 newStaticPeerLocator seeds = do
   tv  <- liftIO $ newTVarIO (Set.fromList seeds)
-  pure $ StaticPeerLocator tv
+  tv2 <- liftIO $ newTVarIO mempty
+  pure $ StaticPeerLocator tv tv2
 
 instance (Ord (Peer e), Pretty (Peer e)) => PeerLocator  e (StaticPeerLocator e)  where
 
-  knownPeers (StaticPeerLocator peers) = do
+  knownPeers (StaticPeerLocator peers e) = do
     ps <- liftIO $ readTVarIO  peers
-    pure $ Set.toList ps
+    excl <- liftIO $ readTVarIO e
+    pure $ Set.toList (ps `Set.difference` excl)
 
-  addPeers (StaticPeerLocator peers) new = do
+  addPeers (StaticPeerLocator peers te) new = do
-    liftIO $ atomically $ modifyTVar' peers (<> Set.fromList new)
+    excl <- liftIO $ readTVarIO te
+    liftIO $ atomically $ modifyTVar' peers ((`Set.difference` excl) . (<> Set.fromList new))
 
-  delPeers (StaticPeerLocator peers) del = do
+  delPeers (StaticPeerLocator peers _) del = do
     liftIO $ atomically $ modifyTVar' peers (`Set.difference` Set.fromList del)
 
+  addExcluded p excl = do
+    liftIO $ atomically $ modifyTVar' (exclude p)  (<> Set.fromList excl)
+
+  bestPeers = knownPeers
 

hbs2-core/lib/HBS2/Net/Proto/Definition.hs

@@ -15,6 +15,7 @@ import HBS2.Net.Proto.BlockChunks
 import HBS2.Net.Proto.BlockInfo
 import HBS2.Net.Proto.Peer
 import HBS2.Net.Proto.PeerAnnounce
+import HBS2.Net.Proto.PeerExchange
 import HBS2.Defaults
 
 import Data.Functor
@@ -65,6 +66,12 @@ instance HasProtocol UDP (PeerAnnounce UDP) where
   decode = either (const Nothing) Just . deserialiseOrFail
   encode = serialise
 
+instance HasProtocol UDP (PeerExchange UDP) where
+  type instance ProtocolId (PeerExchange UDP) = 6
+  type instance Encoded UDP = ByteString
+  decode = either (const Nothing) Just . deserialiseOrFail
+  encode = serialise
+
 
 instance Expires (SessionKey UDP (BlockInfo UDP)) where
   expiresIn _ = Just defCookieTimeoutSec
@@ -94,6 +101,12 @@ instance MonadIO m => HasNonces (PeerHandshake UDP) m where
     n <- liftIO ( Crypto.newNonce <&> Crypto.encode )
     pure $ BS.take 32 n
 
+instance MonadIO m => HasNonces (PeerExchange UDP) m where
+  type instance Nonce (PeerExchange UDP) = BS.ByteString
+  newNonce = do
+    n <- liftIO ( Crypto.newNonce <&> Crypto.encode )
+    pure $ BS.take 32 n
+
 instance MonadIO m => HasNonces () m where
   type instance Nonce () = BS.ByteString
   newNonce = do

hbs2-core/lib/HBS2/Net/Proto/Peer.hs

@@ -10,6 +10,8 @@ import HBS2.Clock
 import HBS2.Net.Proto.Sessions
 import HBS2.Prelude.Plated
 
+import HBS2.System.Logger.Simple
+
 import Data.Maybe
 import Codec.Serialise()
 import Data.ByteString qualified as BS
@@ -31,7 +33,7 @@ makeLenses 'PeerData
 
 data PeerHandshake e =
     PeerPing  PingNonce
-  | PeerPong  (Signature e) (PeerData e)
+  | PeerPong  PingNonce (Signature e) (PeerData e)
   deriving stock (Generic)
 
 newtype KnownPeer e = KnownPeer (PeerData e)
@@ -41,10 +43,10 @@ newtype instance SessionKey e  (KnownPeer e) =
   KnownPeerKey (Peer e)
   deriving stock (Generic,Typeable)
 
-type instance SessionData e (KnownPeer e) = KnownPeer e
+type instance SessionData e (KnownPeer e) = PeerData e
 
 newtype instance SessionKey e (PeerHandshake e) =
-  PeerHandshakeKey (Peer e)
+  PeerHandshakeKey (PingNonce, Peer e)
   deriving stock (Generic, Typeable)
 
 type instance SessionData e (PeerHandshake e) = PingNonce
@@ -61,7 +63,7 @@ sendPing :: forall e m . ( MonadIO m
 
 sendPing pip = do
   nonce <- newNonce @(PeerHandshake e)
-  update nonce (PeerHandshakeKey pip) id
+  update nonce (PeerHandshakeKey (nonce,pip)) id
   request pip (PeerPing @e nonce)
 
 peerHandShakeProto :: forall e m . ( MonadIO m
@@ -93,7 +95,7 @@ peerHandShakeProto =
       own <- peerNonce @e
 
       -- TODO: отправить обратно вместе с публичным ключом
-      response (PeerPong @e sign (PeerData (view peerSignPk creds) own))
+      response (PeerPong @e nonce sign (PeerData (view peerSignPk creds) own))
 
       -- TODO: да и пингануть того самим
 
@@ -102,10 +104,10 @@ peerHandShakeProto =
       unless se $ do
         sendPing pip
 
-    PeerPong sign d -> do
+    PeerPong nonce0 sign d -> do
       pip <- thatPeer proto
 
-      se' <- find @e (PeerHandshakeKey pip) id
+      se' <- find @e (PeerHandshakeKey (nonce0,pip)) id
 
       maybe1 se' (pure ()) $ \nonce -> do
 
@@ -113,11 +115,13 @@ peerHandShakeProto =
 
         let signed = verifySign @e pk sign nonce
 
-        expire (PeerHandshakeKey pip)
+        when signed $ do
+
+          expire (PeerHandshakeKey (nonce0,pip))
 
           -- FIXME: check if peer is blacklisted
           --        right here
-        update (KnownPeer d) (KnownPeerKey pip) id
+          update d (KnownPeerKey pip) id
 
           emit AnyKnownPeerEventKey (KnownPeerEvent pip d)
           emit (ConcretePeerKey pip) (ConcretePeerData pip d)

hbs2-core/lib/HBS2/Net/Proto/PeerExchange.hs

@@ -0,0 +1,137 @@
+{-# Language UndecidableInstances #-}
+module HBS2.Net.Proto.PeerExchange where
+
+import HBS2.Prelude.Plated
+import HBS2.Net.Proto
+import HBS2.Net.Proto.Peer
+import HBS2.Net.PeerLocator
+import HBS2.Net.Proto.Sessions
+import HBS2.Events
+import HBS2.Clock
+import HBS2.Defaults
+
+import Data.ByteString qualified as BS
+import Data.Traversable
+import Data.Functor
+import Data.Maybe
+import Codec.Serialise
+import Data.Hashable
+import Type.Reflection
+
+import HBS2.System.Logger.Simple
+import Prettyprinter
+
+data PeerExchange e =
+    PeerExchangeGet (Nonce (PeerExchange e))
+  | PeerExchangePeers (Nonce (PeerExchange e)) [PeerAddr e]
+  deriving stock (Generic, Typeable)
+
+data PeerExchangePeersEv e
+
+
+
+sendPeerExchangeGet :: forall e m . ( MonadIO m
+                                    , HasNonces (PeerExchange e) m
+                                    , Request e (PeerExchange e) m
+                                    , Sessions e (PeerExchange e) m
+                                    )
+                  => Peer e -> m ()
+
+sendPeerExchangeGet pip = do
+  nonce <- newNonce @(PeerExchange e)
+  update nonce (PeerExchangeKey @e nonce) id
+  request pip (PeerExchangeGet @e nonce)
+
+peerExchangeProto :: forall e m . ( MonadIO m
+                                  , Response e (PeerExchange e) m
+                                  , HasPeerLocator e m
+                                  , HasDeferred e (PeerExchange e) m
+                                  , HasNonces (PeerExchange e) m
+                                  , IsPeerAddr e m
+                                  , Sessions e (KnownPeer e) m
+                                  , Sessions e (PeerExchange e) m
+                                  , EventEmitter e (PeerExchangePeersEv e) m
+                                  , Eq (Nonce (PeerExchange e))
+                                  , Pretty (Peer e)
+                                  )
+                  => PeerExchange e -> m ()
+
+peerExchangeProto =
+  \case
+    PeerExchangeGet n -> deferred proto do
+      -- TODO:  sort peers by their usefulness
+
+      that <- thatPeer proto
+
+      debug $ "PeerExchangeGet" <+> "from" <+> pretty that
+
+      pl   <- getPeerLocator @e
+      pips <- knownPeers @e pl
+
+      pa'   <- forM pips $ \p -> do
+                 auth <- find (KnownPeerKey p) id <&> isJust
+                 if auth then do
+                   a <- toPeerAddr p
+                   pure [a]
+                 else
+                   pure mempty
+
+      let pa = take defPexMaxPeers $ mconcat pa'
+
+      response (PeerExchangePeers @e n pa)
+
+    PeerExchangePeers nonce pips -> do
+
+      pip <- thatPeer proto
+
+      ok <- find (PeerExchangeKey @e nonce) id <&> isJust
+
+      when ok do
+        sa <- mapM (fromPeerAddr @e) pips
+        debug $ "got pex" <+> "from" <+> pretty pip <+> pretty sa
+        expire @e (PeerExchangeKey nonce)
+        emit @e PeerExchangePeersKey (PeerExchangePeersData sa)
+
+   where
+    proto = Proxy @(PeerExchange e)
+
+
+newtype instance SessionKey e (PeerExchange e) =
+  PeerExchangeKey (Nonce (PeerExchange e))
+  deriving stock (Generic, Typeable)
+
+type instance SessionData e (PeerExchange e) = Nonce (PeerExchange e)
+
+data instance EventKey e (PeerExchangePeersEv e) =
+  PeerExchangePeersKey
+  deriving stock (Typeable, Eq,Generic)
+
+deriving instance Eq (Nonce (PeerExchange e)) => Eq (SessionKey e (PeerExchange e))
+instance Hashable (Nonce (PeerExchange e)) => Hashable (SessionKey e (PeerExchange e))
+
+instance Expires (SessionKey e (PeerExchange e)) where
+  expiresIn _ = Just 10
+
+
+instance Typeable (PeerExchangePeersEv e)
+  => Hashable (EventKey e (PeerExchangePeersEv e)) where
+  hashWithSalt salt _ = hashWithSalt salt (someTypeRep p)
+    where
+      p = Proxy @(PeerExchangePeersEv e)
+
+instance EventType ( Event e ( PeerExchangePeersEv e) ) where
+  isPersistent = True
+
+instance Expires (EventKey e (PeerExchangePeersEv e)) where
+  expiresIn _ = Nothing
+
+newtype instance Event e (PeerExchangePeersEv e) =
+  PeerExchangePeersData [Peer e]
+  deriving stock (Typeable)
+
+instance ( Serialise (PeerAddr e)
+         , Serialise (Nonce (PeerExchange e)))
+
+  => Serialise (PeerExchange e)
+
+

hbs2-peer/app/BlockDownload.hs

@@ -22,15 +22,16 @@ import HBS2.System.Logger.Simple
 
 import PeerInfo
 
-import Numeric ( showGFloat )
 import Control.Concurrent.Async
 import Control.Concurrent.STM
 import Control.Monad.Reader
 import Control.Monad.Trans.Maybe
+import Control.Concurrent.STM.TSem as Sem
 import Data.ByteString.Lazy (ByteString)
 import Data.Cache (Cache)
 import Data.Cache qualified as Cache
 import Data.Foldable hiding (find)
+import Data.Hashable
 import Data.HashMap.Strict (HashMap)
 import Data.HashMap.Strict qualified as HashMap
 import Data.IntMap (IntMap)
@@ -40,8 +41,10 @@ import Data.Maybe
 import Data.Set qualified as Set
 import Data.Set (Set)
 import Lens.Micro.Platform
+import Numeric ( showGFloat )
 import Prettyprinter
 import System.Random.Shuffle
+import Type.Reflection
 
 
 calcBursts :: forall a . Integral a => a -> [a] -> [(a,a)]
@@ -648,12 +651,11 @@ blockDownloadLoop env0 = do
                 withDownload env (addBlockInfo p1 hx s)
 
               pips <- knownPeers @e pl
-              for_ pips $ \pip -> request pip (GetBlockSize @e h)
+              for_ pips $ \pip -> do
+                auth <- find (KnownPeerKey pip) id <&> isJust
 
-          p  <- knownPeers @e pl >>= liftIO . shuffleM
+                when auth $ request pip (GetBlockSize @e h) -- FIXME: request only known peers
-
+                                                            --        move this to peer locator
-          -- debug $ "known peers" <+> pretty p
-          -- debug $ "peers/blocks" <+> pretty peers
 
           p0 <- headMay <$> liftIO (shuffleM peers) -- FIXME: random choice to work faster
 
@@ -687,15 +689,30 @@ tossPostponed penv = do
 
   env <- ask
 
-  waitQ <- liftIO newTQueueIO
+  waitQ <- liftIO $ newTBQueueIO 1
+
+  busy <- liftIO $ newTVarIO False
 
   cache <- asks (view blockPostponed)
 
   lift $ subscribe @e AnyKnownPeerEventKey $ \(KnownPeerEvent{}) -> do
-    liftIO $ atomically $ writeTQueue waitQ ()
+    cant <- liftIO $ readTVarIO busy
+    unless cant $ do
+      debug "AnyKnownPeerEventKey"
+      mt <- liftIO $ atomically $ isEmptyTBQueue waitQ
+      when mt do
+        liftIO $ atomically $ writeTBQueue waitQ ()
 
   forever do
-    r <- liftIO $ race ( pause @'Seconds 20 ) ( atomically $ readTQueue waitQ )
+    r <- liftIO $ race ( pause @'Seconds 20 ) ( atomically $ readTBQueue waitQ )
+
+    void $ liftIO $ atomically $ flushTBQueue waitQ
+
+    liftIO $ atomically $ writeTVar busy True
+
+    void $ liftIO $ async $ do
+      pause @'Seconds 5
+      atomically $ writeTVar busy False
 
     let allBack = either (const False) (const True) r
 

hbs2-peer/app/PeerInfo.hs

@@ -5,19 +5,26 @@ module PeerInfo where
 import HBS2.Actors.Peer
 import HBS2.Clock
 import HBS2.Defaults
+import HBS2.Events
 import HBS2.Net.Messaging.UDP
 import HBS2.Net.PeerLocator
 import HBS2.Net.Proto.Peer
+import HBS2.Net.Proto.PeerExchange
 import HBS2.Net.Proto.Sessions
 import HBS2.Net.Proto.Types
 import HBS2.Prelude.Plated
 import HBS2.System.Logger.Simple
 
-import Data.Foldable
+import Data.Maybe
+import Data.Set qualified as Set
+import Data.List qualified as List
+import Data.Foldable hiding (find)
 import Lens.Micro.Platform
 import Control.Concurrent.STM.TVar
 import Control.Concurrent.STM
 import Control.Monad
+import Control.Concurrent.Async
+import System.Random.Shuffle
 import Prettyprinter
 
 data PeerInfo e =
@@ -59,6 +66,35 @@ instance Expires (SessionKey UDP (PeerInfo UDP)) where
   expiresIn = const (Just 600)
 
 
+pexLoop :: forall e m . ( HasPeerLocator e m
+                        , HasPeer e
+                        , Sessions e (KnownPeer e) m
+                        , HasNonces (PeerExchange e) m
+                        , Request e (PeerExchange e) m
+                        , Sessions e (PeerExchange e) m
+                        , MonadIO m
+                        ) => m ()
+
+pexLoop = do
+
+  pause @'Seconds 5
+
+  pl <- getPeerLocator @e
+
+  forever do
+
+    pips <- knownPeers @e pl
+
+    peers' <- forM pips $ \p -> do
+                au <- find @e (KnownPeerKey p) id
+                pure $ maybe1 au mempty (const [p])
+
+    peers <- liftIO (shuffleM (mconcat peers')) <&> take 10 -- FIXME: defaults
+
+    for_ peers sendPeerExchangeGet
+
+    pause @'Seconds 60 -- FIXME: defaults
+
 peerPingLoop :: forall e m . ( HasPeerLocator e m
                              , HasPeer e
                              , HasNonces (PeerHandshake e) m
@@ -67,23 +103,41 @@ peerPingLoop :: forall e m . ( HasPeerLocator e m
                              , Sessions e (PeerHandshake e) m
                              , Sessions e (PeerInfo e) m
                              , Sessions e (KnownPeer e) m
+                             , EventListener e (PeerExchangePeersEv e) m
                              , Pretty (Peer e)
                              , MonadIO m
                              )
              => m ()
-peerPingLoop = forever do
+peerPingLoop = do
-  pause @'Seconds 120 -- FIXME: defaults
+
+  wake <- liftIO newTQueueIO
+
+  subscribe @e PeerExchangePeersKey $ \(PeerExchangePeersData sas) -> do
+    liftIO $ atomically $ writeTQueue wake sas
+
+  forever do
+
+    -- FIXME: defaults
+    r <- liftIO $ race (pause @'Seconds 60)
+                       (atomically $ readTQueue wake)
+
+    sas' <- liftIO $ atomically $ flushTQueue wake <&> mconcat
+
+    let sas = case r of
+          Left{}   -> sas'
+          Right sa -> sa <> sas'
+
     debug "peerPingLoop"
 
     pl <- getPeerLocator @e
-  pips <- knownPeers @e pl
+    pips <- knownPeers @e pl <&> (<> sas) <&> List.nub
 
     for_ pips $ \p -> do
       npi <- newPeerInfo
       pfails <- fetch True npi (PeerInfoKey p) (view peerPingFailed)
       liftIO $ atomically $ modifyTVar pfails succ
       sendPing @e p
-    pause @'Seconds 2 -- NOTE: it's okay?
+      pause @'Seconds 1 -- NOTE: it's okay?
 
       fnum <- liftIO $ readTVarIO pfails
 

hbs2-peer/app/PeerMain.hs

@@ -18,6 +18,7 @@ import HBS2.Net.Proto
 import HBS2.Net.Proto.Definition
 import HBS2.Net.Proto.Peer
 import HBS2.Net.Proto.PeerAnnounce
+import HBS2.Net.Proto.PeerExchange
 import HBS2.Net.Proto.Sessions
 import HBS2.OrDie
 import HBS2.Prelude.Plated
@@ -294,7 +295,22 @@ runPeer opts = Exception.handle myException $ do
                   unless known $ sendPing pip
 
               subscribe @UDP AnyKnownPeerEventKey $ \(KnownPeerEvent p d) -> do
-                unless (pnonce == view peerOwnNonce d) $ do
+
+                -- FIXME: check if we've got a reference to ourselves
+                if pnonce == view peerOwnNonce d then  do
+                  delPeers pl [p]
+                  addExcluded pl [p]
+                  expire (KnownPeerKey p)
+
+                else do
+
+                  prev <- find (KnownPeerKey p) (view peerOwnNonce)
+
+                  case prev of
+                    Just nonce0 | nonce0 /= view peerOwnNonce d -> do
+                      debug "old peer, new address. ignoring"
+
+                    _ -> do
                       addPeers pl [p]
 
                       npi    <- newPeerInfo
@@ -309,16 +325,22 @@ runPeer opts = Exception.handle myException $ do
                 debug "sending first peer announce"
                 request localMulticast (PeerAnnounce @UDP pnonce)
 
-              void $ liftIO $ async $ withPeerM env $ forever $ do
+              let wo = fmap L.singleton
+
+              workers <- do
+
+                wo $ liftIO $ async $ withPeerM env $ forever $ do
                   pause defPeerAnnounceTime -- FIXME: setting!
                   debug "sending local peer announce"
                   request localMulticast (PeerAnnounce @UDP pnonce)
 
-              as <- liftIO $ async $ withPeerM env (peerPingLoop @UDP)
+                wo $ liftIO $ async $ withPeerM env (peerPingLoop @UDP)
 
-              as <- liftIO $ async $ withPeerM env (blockDownloadLoop denv)
+                wo $ liftIO $ async $ withPeerM env (pexLoop @UDP)
 
-              rpc <- liftIO $ async $ withPeerM env $ forever $ do
+                wo $ liftIO $ async $ withPeerM env (blockDownloadLoop denv)
+
+                wo $ liftIO $ async $ withPeerM env $ forever $ do
                           cmd <- liftIO $ atomically $ readTQueue rpcQ
                           case cmd of
                             POKE -> debug "on poke: alive and kicking!"
@@ -370,15 +392,16 @@ runPeer opts = Exception.handle myException $ do
                             _ -> pure ()
 
 
-              me <- liftIO $ async $ withPeerM env $ do
+                wo $ liftIO $ async $ withPeerM env $ do
                   runProto @UDP
                     [ makeResponse (blockSizeProto blk dontHandle)
                     , makeResponse (blockChunksProto adapter)
                     , makeResponse blockAnnounceProto
                     , makeResponse (withCredentials pc . peerHandShakeProto)
+                    , makeResponse peerExchangeProto
                     ]
 
-              void $ liftIO $ waitAnyCatchCancel [me,as]
+              void $ liftIO $ waitAnyCatchCancel workers
 
   let pokeAction _ = do
         liftIO $ atomically $ writeTQueue rpcQ POKE

nix/peer/flake.lock

@@ -112,15 +112,16 @@
         "saltine": "saltine"
       },
       "locked": {
-        "lastModified": 1675599025,
+        "lastModified": 1675665762,
-        "narHash": "sha256-ZVOkBwFMpUHyhsdBg8ubv/h43N7phoLqR1lYbgZEeH0=",
+        "narHash": "sha256-zVfyDqVyPgMXMsj/od1xmOCQz5gkHzi3pTyf83qaqF0=",
         "owner": "voidlizard",
         "repo": "hbs2",
-        "rev": "4ab83f0517c0ab465634a15607d3f0dddeaba3e7",
+        "rev": "85d34209e10016fc243e37e221dca8217af3f7bb",
         "type": "github"
       },
       "original": {
         "owner": "voidlizard",
+        "ref": "wip",
         "repo": "hbs2",
         "type": "github"
       }
@@ -165,11 +166,11 @@
     },
     "nixpkgs_2": {
       "locked": {
-        "lastModified": 1675512093,
+        "lastModified": 1675600654,
-        "narHash": "sha256-u1CY4feK14B57E6T+0Bhkuoj8dpBxCPrWO+SP87UVP8=",
+        "narHash": "sha256-ipsDTkzRq1CAl2g5tYd7ugjVMSKF6KLh9F+5Kso0lT0=",
         "owner": "nixos",
         "repo": "nixpkgs",
-        "rev": "8e8240194eda25b61449f29bb5131e02b28a5486",
+        "rev": "cff83d5032a21aad4f69bf284e95b5f564f4a54e",
         "type": "github"
       },
       "original": {

nix/peer/flake.nix

@@ -5,7 +5,7 @@
   inputs = {
     extra-container.url = "github:erikarvstedt/extra-container";
     nixpkgs.url = "github:nixos/nixpkgs/nixos-22.11";
-    hbs2.url = "github:voidlizard/hbs2";
+    hbs2.url = "github:voidlizard/hbs2/wip";
     hbs2.inputs.nixpkgs.follows = "nixpkgs";
   };