Add MX support (untested).

[haeredes.git] / src / DNS.hs

diff --git a/src/DNS.hs b/src/DNS.hs
index 08d4f210434e6588edd0bcb1147b7813ecf570f3..5222cbec3f3a54c1d8b334bb52b615e56b1cc2e2 100644 (file)
--- a/src/DNS.hs
+++ b/src/DNS.hs
@@ -1,4 +1,7 @@
 module DNS (
+  LookupResult,
+  lookupMX',
+  lookupNS',
   normalize
   )
 where
@@ -9,7 +12,31 @@ import qualified Data.ByteString.Char8 as BS (
   map,
   pack )
 import Data.Char (toLower)
-import Network.DNS.Types (Domain)
+import Network.DNS (
+  Domain,
+  Resolver,
+  lookupMX,
+  lookupNS )
+
+type LookupResult = (Domain, Maybe [Domain])
+
+lookupMX' :: Resolver -> Domain -> IO LookupResult
+lookupMX' resolver domain =
+  lookupMX resolver domain >>= return . pair_em . drop_priority
+  where
+    drop_priority :: Maybe [(Domain, Int)] -> Maybe [Domain]
+    drop_priority = fmap (map fst)
+
+    pair_em :: a -> (Domain, a)
+    pair_em = (,) domain
+
+-- This function keeps the domain matches with its NS records.
+lookupNS' :: Resolver -> Domain -> IO LookupResult
+lookupNS' resolver domain =
+  lookupNS resolver domain >>= return . pair_em
+  where
+    pair_em :: a -> (Domain, a)
+    pair_em = (,) domain
 
 -- | Normalize the given name by lowercasing and appending a trailing
 --   dot (the root) if necessary.