module Main
where
+import Control.Concurrent.ParallelIO.Global (
+ parallelInterleaved,
+ 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, resolvTimeout),
+ defaultResolvConf,
+ makeResolvSeed,
+ normalize,
+ normalizeCase,
+ withResolver )
+import System.Exit (ExitCode(..), exitWith)
+import System.IO (hPutStrLn, stderr)
+
+
+import CommandLine (Args(..), get_args)
+import DNS (
+ LookupResult,
+ lookupMX',
+ lookupNS',
+ resolve_address )
+import ExitCodes (exit_bad_server)
+import Timeout (Timeout(..))
+
+
+-- | Given a list of delegates, report results for this
+-- LookupResult.
+--
+-- If there's an empty list in the second component, there were no
+-- query results, so we report that the domain was not delegated. If
+-- there were some results and there are leftovers (after removing
+-- the delegates), we report those as well.
+--
+report :: [Domain] -- ^ The list of @delgts@
+ -> LookupResult
+ -> IO ()
+
+-- If the lookup resulted in a DNS error, we just ignore the whole
+-- thing.
+report _ (_, Left _) = return ()
+
+-- If the lookup succeeded but there were no results, report that the
+-- domain is not delegated.
+report _ (d, Right []) =
+ putStrLn $ "Domain " ++ (show d) ++ " not delegated."
+
+-- Otherwise, subtract our delegates from the list of results and
+-- report the leftovers.
+report delgts (d, Right hosts) = do
+ let leftovers = hosts \\ delgts
+ unless (null leftovers) $
+ putStrLn $ "Domain " ++
+ (show d) ++
+ " delegates somewhere else: " ++
+ (join " " (map show leftovers))
+
+
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)
+
+ let normalize_function =
+ if (no_append_root cfg)
+ then normalizeCase
+ else normalize
+
+ -- Normalize the given names and delegates
+ let nrml_domains = map normalize_function raw_domains
+ let nrml_delegates = map normalize_function raw_delegates
+
+ rc' <- case (server cfg) of
+ Nothing -> return defaultResolvConf
+ Just s -> do
+ s' <- resolve_address s
+ case s' of
+ Left err -> do
+ let errmsg = show err
+ hPutStrLn stderr ("Bad DNS server or lookup error: " ++ errmsg)
+ exitWith (ExitFailure exit_bad_server)
+ Right [] -> do
+ hPutStrLn stderr ("Hostname " ++ s ++ " has no 'A' records.")
+ exitWith (ExitFailure exit_bad_server)
+ Right (srv:_) ->
+ return $ defaultResolvConf { resolvInfo =
+ RCHostName (show srv) }
+
+ -- Set the timeout from the command line. The resolvTimeout field is
+ -- in microseconds, so we multiply by one million.
+ let rc = rc' { resolvTimeout = 1000 * 1000 * seconds (timeout cfg) }
+ rs <- makeResolvSeed rc
+
+ let lookup_function = case cfg of
+ NS{} -> lookupNS'
+ MX{} -> lookupMX'
+
+ let lookup' d = withResolver rs $ \resolver ->
+ lookup_function resolver d
+
+ -- Construct a list of [IO whatever]. The withResolver calls
+ -- are the ones that should be run in parallel.
+ let actions = map lookup' nrml_domains
+
+ -- Run the lookup actions in parallel.
+ results <- parallelInterleaved actions
+
+ -- Output the results.
+ _ <- mapM (report nrml_delegates) results
+
+ stopGlobalPool