create local server socket

Hash2Pub/Hash2Pub.cabal

@@ -46,7 +46,7 @@ category:            Network
 extra-source-files:  CHANGELOG.md
 
 common deps
-  build-depends:       base ^>=4.12.0.0, containers ^>=0.6.0.1, bytestring, utf8-string ^>=1.0.1.1, network ^>=2.8.0.1, time ^>=1.8.0.2, cmdargs ^>= 0.10, cryptonite ^>= 0.25, memory, async, asn1-encoding, asn1-types, asn1-parse, publicsuffix, network-byte-order, safe
+  build-depends:       base ^>=4.12.0.0, containers ^>=0.6.0.1, bytestring, utf8-string ^>=1.0.1.1, network ^>=2.8.0.1, time ^>=1.8.0.2, cmdargs ^>= 0.10, cryptonite ^>= 0.25, memory, async, asn1-encoding, asn1-types, asn1-parse, publicsuffix, network-byte-order, safe, iproute
   ghc-options:         -Wall
 
 
@@ -74,7 +74,7 @@ executable Hash2Pub
   import: deps
 
   -- adding the library as a dependency
-  build-depends:       Hash2Pub, iproute
+  build-depends:       Hash2Pub
 
   -- .hs or .lhs file containing the Main module.
   main-is:             Main.hs

Hash2Pub/src/Hash2Pub/DHTProtocol.hs

@@ -19,6 +19,8 @@ import Data.Maybe (maybe, fromMaybe)
 import qualified Data.Set as Set
 import qualified Data.Map as Map
 import Data.Time.Clock.POSIX
+import Network.Socket hiding (send, sendTo, recv, recvFrom)
+import Network.Socket.ByteString
 
 import Hash2Pub.FediChord
   ( NodeID
@@ -187,4 +189,3 @@ deleteCacheEntry = Map.update modifier
     modifier (ProxyEntry idPointer _) = Just (ProxyEntry idPointer Nothing)
     modifier NodeEntry {} = Nothing
 
-

Hash2Pub/src/Hash2Pub/FediChord.hs

@@ -38,6 +38,8 @@ module Hash2Pub.FediChord (
   , bsAsIpAddr
   , FediChordConf(..)
   , fediChordInit
+  , mkServerSocket
+  , resolve
                            ) where
 
 import qualified Data.Map.Strict as Map
@@ -53,6 +55,7 @@ import qualified Data.ByteString as BS
 import qualified Data.ByteString.UTF8 as BSU
 import qualified Data.ByteArray as BA
 import qualified Network.ByteOrder as NetworkBytes
+import Data.IP (IPv6, fromHostAddress6, toHostAddress6)
 
 import Hash2Pub.Utils
 
@@ -392,7 +395,6 @@ checkCacheSlices state = case getNodeCache state of
 
 
 -- Todo: DHT backend can learn potential initial bootstrapping points through the instances mentioned in the received AP-relay messages
--- needs to know its own domain anyways for ID generation
 -- persist them on disk so they can be used for all following bootstraps
 
 -- | configuration values used for initialising the FediChord DHT
@@ -402,10 +404,12 @@ data FediChordConf = FediChordConf {
   , confDhtPort :: Int
                                    } deriving (Show, Eq)
 
--- | initialise data structures, compute own IDs.
+-- | initialise data structures, compute own IDs and bind to listening socket
 -- ToDo: load persisted state, thus this function already operates in IO
-fediChordInit :: FediChordConf -> IO NodeState
-fediChordInit conf = return $ NodeState {
+fediChordInit :: FediChordConf -> IO (Socket, NodeState)
+fediChordInit conf = do
+    let
+        initialState = NodeState {
             domain = confDomain conf
           , ipAddr = confIP conf
           , nid = genNodeID (confIP conf) (confDomain conf) 0
@@ -414,7 +418,6 @@ fediChordInit conf = return $ NodeState {
           , vServerID = 0
           , internals = Just internalsInit
                                             }
-      where
         internalsInit = InternalNodeState {
            nodeCache = initCache
           , successors = []
@@ -424,5 +427,38 @@ fediChordInit conf = return $ NodeState {
           , pNumParallelQueries = 2
           , jEntriesPerSlice = 2
                                            }
+    serverSock <- mkServerSocket (ipAddr initialState) (dhtPort initialState)
+    return (serverSock, initialState)
 
 
+
+--fediChordJoin :: NodeState              -- ^ the local 'NodeState'
+--              -> (String, PortNumber)   -- ^ domain and port of a bootstrapping node
+--              -> IO Either String NodeState -- ^ the joined 'NodeState' after a successful
+--                                         -- join, otherwise an error message
+--fediChordJoin
+
+
+-- ====== network socket operations ======
+
+-- | resolve a specified host and return the 'AddrInfo' for it.
+-- If no hostname or IP is specified, the 'AddrInfo' can be used to bind to all
+-- addresses;
+-- if no port is specified an arbitrary free port is selected.
+resolve :: Maybe String         -- ^ hostname or IP address to be resolved
+        -> Maybe PortNumber     -- ^ port number of either local bind or remote
+        -> IO AddrInfo
+resolve host port = let
+    hints = defaultHints { addrFamily = AF_INET6, addrSocketType = Datagram
+                         , addrFlags = [AI_PASSIVE] }
+    in
+    head <$> getAddrInfo (Just hints) host (show <$> port)
+
+-- | create an unconnected UDP Datagram 'Socket' bound to the specified address
+mkServerSocket :: HostAddress6 -> PortNumber -> IO Socket
+mkServerSocket ip port = do
+    sockAddr <- addrAddress <$> resolve (Just $ show . fromHostAddress6 $ ip) (Just port)
+    sock <- socket AF_INET6 Datagram defaultProtocol
+    setSocketOption sock IPv6Only 1
+    bind sock sockAddr
+    return sock

Hash2Pub/src/Hash2Pub/Main.hs

@@ -11,8 +11,9 @@ main = do
     -- probably use `tomland` for that
     conf <- readConfig
     -- ToDo: load persisted caches, bootstrapping nodes …
-    thisNode <- fediChordInit conf
+    (serverSock, thisNode) <- fediChordInit conf
     print thisNode
+    print serverSock
     return ()
 
 readConfig :: IO FediChordConf