X-Git-Url: http://gitweb.michael.orlitzky.com/?p=haeredes.git;a=blobdiff_plain;f=src%2FMain.hs;h=679a1ac1fe1d0dc3cf684420596676dde91e10e5;hp=0c215b758a59501b6d4c8bd049a5dd4cab53e9ee;hb=71c5a7f6c3a8ecb4c17f454e0e27a21538379f58;hpb=fa4220513eb9d2036c3db0cc9c518c6346050318

diff --git a/src/Main.hs b/src/Main.hs
index 0c215b7..679a1ac 100644
--- a/src/Main.hs
+++ b/src/Main.hs
@@ -2,48 +2,68 @@ module Main
 where
 
 import Control.Concurrent.ParallelIO.Global (
-  parallel,
+  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),
+  ResolvConf(resolvInfo, resolvTimeout),
   defaultResolvConf,
   makeResolvSeed,
   withResolver )
+import System.Exit (ExitCode(..), exitWith)
+import System.IO (hPutStrLn, stderr)
+
 
 import CommandLine (Args(..), get_args)
 import DNS (
   LookupResult,
   lookupMX',
   lookupNS',
-  normalize )
-
-report :: (Domain, Maybe [Domain]) -> IO ()
-report (d, Nothing) =
+  normalize,
+  normalize_case,
+  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."
-report (d, Just leftovers) =
-  if null leftovers
-  then return ()
-  else 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)
 
+-- 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 ()
@@ -59,25 +79,51 @@ main = do
   -- 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
-
-  let rc = case (server cfg) of
-             Nothing -> defaultResolvConf
-             Just s -> defaultResolvConf { resolvInfo = RCHostName s }
+  let normalize_function =
+        if (no_append_root cfg)
+        then normalize_case
+        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'
-
-  _ <- 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)
+                          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