X-Git-Url: http://gitweb.michael.orlitzky.com/?p=haeredes.git;a=blobdiff_plain;f=src%2FMain.hs;h=70fa2f57c842ebb34c96e2e268070065b2488530;hp=142ace670cf62d4a83796c431185d5af2eeb891f;hb=e862342c38e41176a7ab300b6d7ed03cf0ffd6b2;hpb=825753e2731b8491d93d9f2d66b457fe31b1c763

diff --git a/src/Main.hs b/src/Main.hs
index 142ace6..70fa2f5 100644
--- a/src/Main.hs
+++ b/src/Main.hs
@@ -1,68 +1,129 @@
 module Main
 where
 
-import qualified Data.ByteString.Char8 as BS (pack)
+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, splitWs)
-
+import Data.String.Utils (join)
 import Network.DNS (
   Domain,
   FileOrNumericHost(RCHostName),
-  ResolvConf(resolvInfo),
+  ResolvConf(resolvInfo, resolvTimeout),
   defaultResolvConf,
-  lookupNS,
   makeResolvSeed,
-  withResolver
-  )
+  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(..))
+
 
-import System.IO (hGetContents, stdin)
+-- | 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 ()
 
-import CommandLine (Args(..), Delegates(..), get_args)
+-- If the lookup resulted in a DNS error, we just ignore the whole
+-- thing.
+report _ (_, Left _) = return ()
 
-report :: (Domain, Maybe [Domain]) -> IO ()
-report (d, Nothing) =
+-- 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 :: Delegates -> (Domain, Maybe [Domain]) -> (Domain, Maybe [Domain])
-clean _ p@(_, Nothing) = p
-clean (Delegates ds') (d, Just targets) =
-  (d, Just $ targets \\ ds)
-  where
-    ds = map BS.pack ds'
+
+-- 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
   cfg <- get_args
-  print cfg
-  input <- hGetContents stdin
+
+  -- This reads stdin.
+  input <- BS.getContents
 
   -- Split the input on any whitespace characters.
-  let domains' = splitWs input
+  let raw_domains = BS.words input
+
+  -- Convert these to ByteStrings.
+  let raw_delegates = map BS.pack (delegates cfg)
 
-  -- Convert those Strings to ByteStrings
-  let domains  = map BS.pack domains'
+  let normalize_function =
+        if (no_append_root cfg)
+        then normalizeCase
+        else normalize
 
-  let rc = case (server cfg) of
-             Nothing -> defaultResolvConf
-             Just s -> defaultResolvConf { resolvInfo = RCHostName s }
+  -- 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
-  withResolver rs $ \resolver -> do
-    -- This function keeps the domain matches with its NS records.
-    let lookupNS' = \d -> (lookupNS resolver d) >>= (return . ((,) d))
-    domains_ns <- mapM lookupNS' domains
-    let cdns = map (clean (delegates cfg)) domains_ns
-
-    case cfg of
-      (NS _ _) ->
-        -- We're only checking NS records, so report what we found.
-        mapM_ report cdns
-      (MX _ _) ->
-        print "Hello, world."
+
+  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