-module Main
+module Main (main)
where
-import qualified Data.ByteString.Char8 as BS (pack)
-import Data.List ((\\))
-import Data.String.Utils (join, splitWs)
-
+import Control.Concurrent.ParallelIO.Global (
+ parallelInterleaved,
+ stopGlobalPool )
+import Control.Monad (unless)
+import qualified Data.ByteString.Char8 as BS (
+ getContents,
+ pack,
+ words )
+import Data.List ( (\\), intersperse, sort )
import Network.DNS (
+ DNSError(NameError),
Domain,
FileOrNumericHost(RCHostName),
- ResolvConf(resolvInfo),
+ ResolvConf(resolvInfo, resolvTimeout),
defaultResolvConf,
- lookupNS,
makeResolvSeed,
- withResolver
- )
+ normalize,
+ normalizeCase,
+ withResolver )
+import System.Exit (ExitCode(ExitFailure), exitWith)
+import System.IO (hPutStrLn, stderr)
+
+import CommandLine (
+ Args(NS,MX,delegates,no_append_root,server,timeout),
+ get_args)
+import DNS (
+ LookupResult,
+ lookupMX',
+ lookupNS',
+ resolve_address )
+import ExitCodes (exit_bad_server)
+import Timeout (Timeout(seconds))
-import System.IO (hGetContents, stdin)
-import CommandLine (Args(..), Delegates(..), get_args)
+-- | 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.
+--
+-- Before processing, all names are normalized using the supplied
+-- function @normalize_function@. Ideally this should be the same
+-- function applied to the user-input names.
+--
+report :: [Domain] -- ^ The list of @delgts@
+ -> (Domain -> Domain) -- ^ Domain name normalization function,
+ -- @normalize_function@.
+ -> LookupResult
+ -> IO ()
-report :: (Domain, Maybe [Domain]) -> IO ()
-report (d, Nothing) =
+-- If the lookup succeeded but there were no results, report that the
+-- domain is not delegated. Note that the behavior of the DNS library
+-- changed with regard to this at some point: we used to get back
+-- a "success," but with an empty list of results. Now a NameError
+-- (which is not actually an error!) is returned.
+report _ _ (d, Left NameError) =
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)
+
+-- If the lookup resulted in some other DNS error, we just ignore the
+-- whole thing.
+report _ _ (_, Left _) = return ()
+
+-- Otherwise, subtract our delegates from the list of results and
+-- report the leftovers.
+report delgts normalize_function (d, Right raw_hosts) = do
+ let nrml_hosts = map normalize_function raw_hosts
+ -- Sort the leftovers so that we can test the expected output.
+ let leftovers = sort (nrml_hosts \\ delgts)
+ unless (null leftovers) $
+ putStrLn $ "Domain " ++
+ (show d) ++
+ " delegates somewhere else: " ++
+ (join " " (map show leftovers))
where
- ds = map BS.pack ds'
+ -- Create one big string by joining together a list of smaller
+ -- strings and placing a delimiter between them.
+ join :: String -> [String] -> String
+ join delimiter strings = concat (intersperse delimiter strings)
+
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 a_million = 1000 * 1000 :: Int
+ let rc = rc' { resolvTimeout = a_million * 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 normalize_function) results
+
+ stopGlobalPool
projects / haeredes.git / blobdiff