module DNS (
LookupResult,
+ dns_properties,
+ dns_tests,
lookupMX',
lookupNS',
normalize,
append,
last,
map,
+ null,
pack )
import Data.Char (toLower)
import Data.IP (IPv4)
rdata,
rrtype,
withResolver )
+import Test.Framework (Test, testGroup)
+import Test.Framework.Providers.HUnit (testCase)
+import Test.Framework.Providers.QuickCheck2 (testProperty)
+import Test.HUnit (assertEqual)
import Text.Read (readMaybe)
type LookupResult = (Domain, Maybe [Domain])
unTag (RD_NS dm) = dm
unTag _ = error "lookupNS_authority"
+
+-- | Takes a String representing either a hostname or an IP
+-- address. If a hostname was supplied, it is resolved to either an
+-- IPv4 or Nothing. If an IP address is supplied, it is returned as an
+-- IPv4.
+--
+-- Examples:
+--
+-- >>> resolve_address "example.com"
+-- Just 93.184.216.119
+-- >>> resolve_address "93.184.216.119"
+-- Just 93.184.216.119
+--
resolve_address :: String -> IO (Maybe IPv4)
resolve_address s =
case read_result of
read_result :: Maybe IPv4
read_result = readMaybe s
+
+-- | This calls lookupMX, and returns the result as the second
+-- component of a tuple whose first component is the domain name
+-- itself.
+--
+-- Examples:
+--
+-- The example domain, example.com, has no MX record.
+--
+-- >>> rs <- makeResolvSeed defaultResolvConf
+-- >>> let domain = BS.pack "example.com."
+-- >>> withResolver rs $ \resolver -> lookupMX' resolver domain
+-- ("example.com.",Nothing)
+--
lookupMX' :: Resolver -> Domain -> IO LookupResult
lookupMX' resolver domain =
liftM (pair_em . drop_priority) $ lookupMX resolver domain
pair_em :: a -> (Domain, a)
pair_em = (,) domain
--- This function keeps the domain matches with its NS records.
+
+-- | This calls lookupNS, and returns the result as the second
+-- component of a tuple whose first component is the domain name
+-- itself.
+--
+-- Examples:
+--
+-- The example domain, example.com, does have NS records, but the
+-- order in which they are returned is variable, so we have to sort
+-- them to get a reliable result.
+--
+-- >>> import Data.List (sort)
+-- >>> let sort_snd (x,y) = (x, sort <$> y)
+-- >>> rs <- makeResolvSeed defaultResolvConf
+-- >>> let domain = BS.pack "example.com."
+-- >>> withResolver rs $ \resolver -> sort_snd <$> lookupNS' resolver domain
+-- ("example.com.",Just ["a.iana-servers.net.","b.iana-servers.net."])
+--
lookupNS' :: Resolver -> Domain -> IO LookupResult
lookupNS' resolver domain = do
answer_result <- lookupNS resolver domain
combine Nothing m2 = m2
combine (Just ds1) (Just ds2) = Just (ds1 ++ ds2)
--- | Normalize the given name by lowercasing and appending a trailing
--- dot (the root) if necessary.
+-- | Perform both normalize_case and normalize_root.
normalize :: Domain -> Domain
normalize = normalize_case . normalize_root
-
+-- | Normalize the given name by appending a trailing dot (the DNS
+-- root) if necessary.
normalize_root :: Domain -> Domain
normalize_root d
+ | BS.null d = BS.pack "."
| BS.last d == '.' = d
| otherwise = d `BS.append` trailing_dot
where
trailing_dot = BS.pack "."
+-- | Normalize the given name by lowercasing it.
normalize_case :: Domain -> Domain
normalize_case = BS.map toLower
+
+
+test_normalize_case :: Test
+test_normalize_case =
+ testCase desc $
+ assertEqual desc expected actual
+ where
+ desc = "normalize_case lowercases DNS names"
+ expected = BS.pack "example.com"
+ actual = normalize_case $ BS.pack "ExAmPlE.COM"
+
+prop_normalize_case_idempotent :: String -> Bool
+prop_normalize_case_idempotent s =
+ (normalize_case . normalize_case) bs == normalize_case bs
+ where
+ bs = BS.pack s
+
+test_normalize_root_adds_dot :: Test
+test_normalize_root_adds_dot =
+ testCase desc $
+ assertEqual desc expected actual
+ where
+ desc = "normalize_root adds a trailing dot"
+ expected = BS.pack "example.com."
+ actual = normalize_root $ BS.pack "example.com"
+
+prop_normalize_root_idempotent :: String -> Bool
+prop_normalize_root_idempotent s =
+ (normalize_root . normalize_root) bs == normalize_root bs
+ where
+ bs = BS.pack s
+
+dns_tests :: Test
+dns_tests =
+ testGroup "DNS Tests" [
+ test_normalize_case,
+ test_normalize_root_adds_dot ]
+
+dns_properties :: Test
+dns_properties =
+ testGroup "DNS Properties" [
+ testProperty
+ "normalize_case is idempotent"
+ prop_normalize_case_idempotent,
+ testProperty
+ "normalize_root is idempotent"
+ prop_normalize_root_idempotent ]