Support hostnames as --server arguments.

[haeredes.git] / src / Main.hs

diff --git a/src/Main.hs b/src/Main.hs
index b141e302f8298e50ef10600616b3084b64cc6c18..4aa0c326de6f5ebbc81bd371a1c46c31dac10bd0 100644 (file)
--- a/src/Main.hs
+++ b/src/Main.hs
@@ -1,6 +1,95 @@
 module Main
 where
 
+import Control.Concurrent.ParallelIO.Global (
+  parallel,
+  stopGlobalPool )
+import Control.Monad (unless)
+import qualified Data.ByteString.Char8 as BS (
+  getContents,
+  pack,
+  words )
+import Data.List ((\\))
+import Data.String.Utils (join)
+import Network.DNS (
+  Domain,
+  FileOrNumericHost(RCHostName),
+  ResolvConf(resolvInfo),
+  defaultResolvConf,
+  makeResolvSeed,
+  withResolver )
+import System.Exit (ExitCode(..), exitWith)
+import System.IO (hPutStrLn, stderr)
+
+
+import CommandLine (Args(..), get_args)
+import DNS (
+  LookupResult,
+  lookupMX',
+  lookupNS',
+  normalize,
+  resolve_address )
+import ExitCodes (exit_bad_server)
+
+report :: (Domain, Maybe [Domain]) -> IO ()
+report (d, Nothing) =
+  putStrLn $ "Domain " ++ (show d) ++ " not delegated."
+report (d, Just leftovers) =
+  unless (null leftovers) $
+    putStrLn $ "Domain " ++
+               (show d) ++
+               " delegates somewhere else: " ++
+               (join " " (map show leftovers))
+
+clean :: [Domain] -- ^ List of delegates, @ds@
+      -> LookupResult
+      -> LookupResult
+clean _ p@(_, Nothing) = p
+clean delgts (d, Just targets) =
+  (d, Just $ targets \\ delgts)
+
+
+
 main :: IO ()
 main = do
-  putStrLn "Hello, World."
+  cfg <- get_args
+
+  -- This reads stdin.
+  input <- BS.getContents
+
+  -- Split the input on any whitespace characters.
+  let raw_domains = BS.words input
+
+  -- Convert these to ByteStrings.
+  let raw_delegates = map BS.pack (delegates cfg)
+
+  -- Normalize the given names and delegates
+  let nrml_domains   = map normalize raw_domains
+  let nrml_delegates = map normalize raw_delegates
+
+  rc <- case (server cfg) of
+          Nothing -> return defaultResolvConf
+          Just s -> do
+            s' <- resolve_address s
+            case s' of
+              Nothing -> do
+                hPutStrLn stderr ("Bad DNS server or lookup error: " ++ s)
+                exitWith (ExitFailure exit_bad_server)
+              Just s'' ->
+                return $ defaultResolvConf { resolvInfo =
+                                               RCHostName (show s'') }
+
+  rs <- makeResolvSeed rc
+
+  let lookup_function = case cfg of
+                          (NS _ _) -> lookupNS'
+                          (MX _ _) -> lookupMX'
+
+  _ <- withResolver rs $ \resolver -> do
+         -- Bad stuff happens if we try to run these lookups in parallel
+         -- instead of the reports.
+         records <- mapM (lookup_function resolver) nrml_domains
+         let cleaned_records = map (clean nrml_delegates) records
+         parallel (map report cleaned_records)
+
+  stopGlobalPool