4 import Control.Concurrent.ParallelIO.Global (
7 import Control.Monad (unless)
8 import qualified Data.ByteString.Char8 as BS (
12 import Data.List ( (\\) )
13 import Data.String.Utils (join)
16 FileOrNumericHost(RCHostName),
17 ResolvConf(resolvInfo, resolvTimeout),
23 import System.Exit (ExitCode(ExitFailure), exitWith)
24 import System.IO (hPutStrLn, stderr)
27 Args(NS,MX,delegates,no_append_root,server,timeout),
34 import ExitCodes (exit_bad_server)
35 import Timeout (Timeout(seconds))
38 -- | Given a list of delegates, report results for this
41 -- If there's an empty list in the second component, there were no
42 -- query results, so we report that the domain was not delegated. If
43 -- there were some results and there are leftovers (after removing
44 -- the delegates), we report those as well.
46 -- Before processing, all names are normalized using the supplied
47 -- function @normalize_function@. Ideally this should be the same
48 -- function applied to the user-input names.
50 report :: [Domain] -- ^ The list of @delgts@
51 -> (Domain -> Domain) -- ^ Domain name normalization function,
52 -- @normalize_function@.
56 -- If the lookup resulted in a DNS error, we just ignore the whole
58 report _ _ (_, Left _) = return ()
60 -- If the lookup succeeded but there were no results, report that the
61 -- domain is not delegated.
62 report _ _ (d, Right []) =
63 putStrLn $ "Domain " ++ (show d) ++ " not delegated."
65 -- Otherwise, subtract our delegates from the list of results and
66 -- report the leftovers.
67 report delgts normalize_function (d, Right raw_hosts) = do
68 let nrml_hosts = map normalize_function raw_hosts
69 let leftovers = nrml_hosts \\ delgts
70 unless (null leftovers) $
71 putStrLn $ "Domain " ++
73 " delegates somewhere else: " ++
74 (join " " (map show leftovers))
82 input <- BS.getContents
84 -- Split the input on any whitespace characters.
85 let raw_domains = BS.words input
87 -- Convert these to ByteStrings.
88 let raw_delegates = map BS.pack (delegates cfg)
90 let normalize_function =
91 if (no_append_root cfg)
95 -- Normalize the given names and delegates
96 let nrml_domains = map normalize_function raw_domains
97 let nrml_delegates = map normalize_function raw_delegates
99 rc' <- case (server cfg) of
100 Nothing -> return defaultResolvConf
102 s' <- resolve_address s
105 let errmsg = show err
106 hPutStrLn stderr ("Bad DNS server or lookup error: " ++ errmsg)
107 exitWith (ExitFailure exit_bad_server)
109 hPutStrLn stderr ("Hostname " ++ s ++ " has no 'A' records.")
110 exitWith (ExitFailure exit_bad_server)
112 return $ defaultResolvConf { resolvInfo =
113 RCHostName (show srv) }
115 -- Set the timeout from the command line. The resolvTimeout field is
116 -- in microseconds, so we multiply by one million.
117 let a_million = 1000 * 1000 :: Int
118 let rc = rc' { resolvTimeout = a_million * seconds (timeout cfg) }
119 rs <- makeResolvSeed rc
121 let lookup_function = case cfg of
125 let lookup' d = withResolver rs $ \resolver ->
126 lookup_function resolver d
128 -- Construct a list of [IO whatever]. The withResolver calls
129 -- are the ones that should be run in parallel.
130 let actions = map lookup' nrml_domains
132 -- Run the lookup actions in parallel.
133 results <- parallelInterleaved actions
135 -- Output the results.
136 _ <- mapM (report nrml_delegates normalize_function) results