1 files changed, 9 insertions, 0 deletions

diff --git a/src/Network/Tox/Crypto/Handlers.hs b/src/Network/Tox/Crypto/Handlers.hs
index f0332df0..50224178 100644
--- a/src/Network/Tox/Crypto/Handlers.hs
+++ b/src/Network/Tox/Crypto/Handlers.hs
@@ -360,6 +360,15 @@ type NewSessionHook = IOHook (Maybe NoSpam) NetCryptoSession
 addNewSessionHook :: NetCryptoSessions -> NewSessionHook -> STM ()
 addNewSessionHook allsessions@(NCSessions { announceNewSessionHooks }) hook = modifyTVar announceNewSessionHooks (hook:)
 
+addDestroySessionHook :: NetCryptoSession -> (Maybe Int) -> (NetCryptoSession -> IO ()) -> STM Int
+addDestroySessionHook netcrypto mbkey hook = do
+    modifyTVar (ncDestoryHooks netcrypto) $ \hooklist ->
+        case mbkey of
+            Just key -> ((key,hook):filter ((/=key) . fst) hooklist)
+            Nothing -> let maxkey = maximum (map fst hooklist)
+                           in if null hooklist then [(0,hook)] else (maxkey+1,hook):hooklist
+    fst . head <$> readTVar (ncDestoryHooks netcrypto)
+
 forgetCrypto :: TransportCrypto -> NetCryptoSessions -> NetCryptoSession -> STM ()
 forgetCrypto crypto (NCSessions {netCryptoSessions,netCryptoSessionsByKey}) session = do
     let HaveDHTKey addr = ncSockAddr session