Add the Network.DNS.RBL.Host module.

[dead/harbl.git] / src / Network / DNS / RBL.hs

diff --git a/src/Network/DNS/RBL.hs b/src/Network/DNS/RBL.hs
index 5775c47f8464deb66079eaa1c55149f5014d9089..3c32e5d97b990d654b92bf1e5ad40279b529c65e 100644 (file)
--- a/src/Network/DNS/RBL.hs
+++ b/src/Network/DNS/RBL.hs
@@ -1,10 +1,95 @@
-module Network.DNS.RBL ( lookup_simple )
+module Network.DNS.RBL ( lookup_single )
 where
 
--- | Look up the given @host@ on all of the white/blacklists contained
---   in @rbls@. If the results, multiplied by their weights, add up to
---   (at least) @threshold@, then @True@ is returned; that is, the
---   @host@ is \"listed\". Otherwise, @False@ is returned.
+import Data.ByteString.Char8 ( append, pack )
+import Data.IP ( IPv4 )
+import Data.List ( intercalate )
+import Data.Maybe ( catMaybes )
+import Network.DNS (
+  DNSError,
+  Resolver,
+  defaultResolvConf,
+  lookupA,
+  makeResolvSeed,
+  withResolver )
+
+import Network.DNS.RBL.Domain ( UserDomain )
+import Network.DNS.RBL.Host ( Host, reverse_labels )
+import Network.DNS.RBL.IPv4Pattern ( addresses )
+import Network.DNS.RBL.Pretty ( Pretty(..) )
+import Network.DNS.RBL.Site ( Site(..), Weight(..) )
+
+
+
+-- | In most applications, you will want to know /why/ a host is
+--   blacklisted. This type stores those details: the site on which
+--   the host was listed, and the return codes that we got back from
+--   the blacklist.
+data ListingDetails = ListingDetails Site [IPv4]
+
+
+-- | Create a nice \"error\" message from a host and the details of
+--   why it was listed.
+--
+listing_message :: Host -> ListingDetails -> String
+listing_message host (ListingDetails (Site d _ w) codes) =
+  "host " ++ (pretty_show host) ++ " " ++
+  "listed on " ++ (pretty_show d) ++ " " ++
+  "with return code(s) " ++ return_codes ++ " " ++
+  "having weight " ++ (pretty_show w)
+  where
+    return_codes :: String
+    return_codes = intercalate "," (map show codes)
+
+
+-- | This code is stolen from 'Network.DNS.lookupRDNS', which I'm
+--   pretty sure I wrote anyway.
 --
-lookup_simple :: String -> Int -> String -> Bool
-lookup_simple rbls threshold host = undefined
+dnslookup :: Resolver -> UserDomain -> Host -> IO (Either DNSError [IPv4])
+dnslookup rlv rbl host = lookupA rlv dom
+  where
+    suffix = pack $ "." ++ (pretty_show rbl)
+    dom = (reverse_labels host) `append` suffix
+
+
+-- | See 'lookup_single'. The \"prime\" version here takes an
+--   additional @resolver@ argument for performance reasons.
+--
+lookup_single' :: Resolver
+               -> Host
+               -> Site
+               -> IO (Maybe ListingDetails)
+lookup_single' resolver host site@(Site d p (Weight w)) = do
+  response <- dnslookup resolver d host
+  case response of
+    Left _ -> return Nothing -- Not listed, no error to report
+    Right ipv4s ->
+      case p of
+        -- No pattern given, but we got a hit.
+        Nothing -> return $ Just (ListingDetails site ipv4s)
+        Just pat -> do
+          let ipv4_strings = map show ipv4s
+          let codes = addresses pat
+          let hits = map (`elem` codes) ipv4_strings
+          if or hits -- if any of the returned addresses match the pattern
+          then return $ Just (ListingDetails site ipv4s)
+          else return Nothing
+
+
+-- | Look up a single...
+lookup_single :: Host
+              -> Site
+              -> IO (Maybe ListingDetails)
+lookup_single host site = do
+  rs <- makeResolvSeed defaultResolvConf
+  withResolver rs $ \resolver -> lookup_single' resolver host site
+
+
+lookup :: Host -> [Site] -> IO [ListingDetails]
+lookup host sites = do
+  rs <- makeResolvSeed defaultResolvConf
+  withResolver rs $ \resolver -> do
+    results <- mapM (lookup_single' resolver host) sites
+    return $ catMaybes results
+
+