dprox-0.4.2: src/Main.hs
-- SPDX-License-Identifier: BSD-3-Clause
--
-- Copyright (C) 2019 Bin Jin. All Rights Reserved.
{-# LANGUAGE OverloadedStrings #-}
{-# LANGUAGE RecordWildCards #-}
{-# LANGUAGE TupleSections #-}
module Main where
import Control.Concurrent (forkIO, threadDelay)
import Control.Exception (SomeException, handle)
import Control.Monad (forM, forever, join, void)
import Data.ByteString (ByteString)
import Data.Foldable qualified as F
import Data.Hashable (Hashable (..))
import Data.IP qualified as IP
import Data.IP.RouteTable qualified as IP
import Data.Map qualified as M
import Data.Maybe (fromMaybe, isJust, maybeToList)
import Data.Set qualified as S
import Data.Streaming.Network (bindPortUDP)
import Data.Version (showVersion)
import Network.DNS qualified as DNS
import Network.Socket.ByteString (recvFrom, sendTo)
import Config
import DomainRoute
import Log
import LRU
import Paths_dprox
instance Hashable DNS.TYPE where
hashWithSalt s = hashWithSalt s . DNS.fromTYPE
type Resolver = DNS.Domain -> DNS.TYPE -> IO (Either DNS.DNSError [DNS.RData])
type CachedResolver = DNS.Domain -> DNS.TYPE -> IO (Either DNS.DNSError (DNS.TTL, [DNS.RData]))
processQuery :: CachedResolver -> DNS.Question -> IO [DNS.ResourceRecord]
processQuery resolver (DNS.Question qd qt) = handle handler $ do
res <- resolver qd qt
case res of
Left _ -> return []
Right (ttl, r) -> return (map (wrapper ttl) r)
where
handler :: SomeException -> IO [DNS.ResourceRecord]
handler _ = return []
wrapper :: DNS.TTL -> DNS.RData -> DNS.ResourceRecord
wrapper ttl rdata = DNS.ResourceRecord qd (getType rdata) DNS.classIN ttl rdata
getType :: DNS.RData -> DNS.TYPE
getType DNS.RD_A{} = DNS.A
getType DNS.RD_NS{} = DNS.NS
getType DNS.RD_CNAME{} = DNS.CNAME
getType DNS.RD_SOA{} = DNS.SOA
getType DNS.RD_NULL{} = DNS.NULL
getType DNS.RD_PTR{} = DNS.PTR
getType DNS.RD_MX{} = DNS.MX
getType DNS.RD_TXT{} = DNS.TXT
getType DNS.RD_AAAA{} = DNS.AAAA
getType _ = qt
parseDNS :: ByteString -> Either DNS.DNSError DNS.DNSMessage
parseDNS bs = do
q <- DNS.decode bs
if DNS.qOrR (DNS.flags (DNS.header q)) == DNS.QR_Query
then return q
else Left DNS.FormatError
processDNS :: CachedResolver -> DNS.DNSMessage -> IO (Either DNS.DNSError ByteString)
processDNS resolver DNS.DNSMessage{ DNS.header = hd, DNS.question = q } = do
rrs <- mapM (processQuery resolver) q
let hd0 = DNS.header DNS.defaultResponse
resp = DNS.defaultResponse {
DNS.header = hd0 { DNS.identifier = DNS.identifier hd },
DNS.question = q,
DNS.answer = concat rrs
}
return (Right (DNS.encode resp))
handleServer :: DomainRoute (Maybe Resolver) -> Resolver
handleServer route qd qt = case resolver of
Nothing -> return (Left DNS.NameError)
Just resolver' -> resolver' qd qt
where
resolver = join (getDomainRouteByPrefix route qd)
handleAddressAndHosts :: DomainRoute [IP] -> DomainRoute [IP] -> Resolver -> Resolver
handleAddressAndHosts address hosts resolver qd qt =
if null ips then resolver qd qt else return (Right userDefined)
where
ips1 = fromMaybe [] $ getDomainRouteByPrefix address qd
ips2 = fromMaybe [] $ getDomainRouteExact hosts qd
ips | null ips2 = ips1
| otherwise = ips2
ipv4 = [DNS.RD_A ipv4addr | IPv4 ipv4addr <- ips]
ipv6 = [DNS.RD_AAAA ipv6addr | IPv6 ipv6addr <- ips]
userDefined | qt == DNS.A = ipv4
| qt == DNS.AAAA = ipv6
| otherwise = []
handleBogusNX :: S.Set IP -> Resolver -> Resolver
handleBogusNX blacklist resolver qd qt =
fmap (filter (not . isBlacklisted)) <$> resolver qd qt
where
isBlacklisted (DNS.RD_A ipv4) = IPv4 ipv4 `S.member` blacklist
isBlacklisted (DNS.RD_AAAA ipv6) = IPv6 ipv6 `S.member` blacklist
isBlacklisted _ = False
handleIPSet :: [IPMask] -> IPSetMatch -> Maybe Resolver -> LRUCache DNS.Domain () -> CachedResolver -> CachedResolver
handleIPSet [] _ _ _ = id
handleIPSet _ _ Nothing _ = id
handleIPSet ipset match (Just ipsetResolver) cache = handleWithResolver
where
iproute = IP.fromList $ zip ipset $ repeat ()
inIPSet ip = isJust $ IP.lookup (IP.makeAddrRange ip 32) iproute
check NoneMatch = not . any inIPSet
check AllMatch = all inIPSet
check AnyMatch = any inIPSet
check AnyNotMatch = any (not.inIPSet)
handleWithResolver resolver qd qt@DNS.A = do
cachedInIPSet <- isJust <$> lookupCache qd cache
if cachedInIPSet
then fmap (1,) <$> ipsetResolver qd qt
else do
res <- resolver qd qt
case res of
Left _ -> return res
Right (_, rs) -> do
let ipv4s = [ipv4 | DNS.RD_A ipv4 <- rs]
if not (null ipv4s) && check match ipv4s
then do
updateCache qd () cache
fmap (1,) <$> ipsetResolver qd qt
else return res
handleWithResolver resolver qd qt = resolver qd qt
makeResolverCache :: Int -> DNS.TTL -> IO (Resolver -> CachedResolver)
makeResolverCache sz ttl | sz <= 0 = return $ \r qd qt -> fmap (ttl,) <$> r qd qt
makeResolverCache sz ttl = do
cache <- newCache sz ttl
_ <- forkIO $ forever $ do
threadDelay (fromInteger (fromIntegral ttl * 1000000 `div` 3))
purgeCache cache
let process resolver qd qt = do
let k = (qd, qt)
res <- lookupCache k cache
case res of
Just (ttl', v) -> return (Right (max ttl' 3, v))
Nothing -> do
resolved <- resolver qd qt
case resolved of
Left e -> return (Left e)
Right v -> do
updateCache k v cache
return (Right (ttl, v))
return process
main :: IO ()
main = getConfig >>= \(GlobalConfig{..}, conf) -> withLogger (LogStdout 4096) loglevel $ \logger -> do
logger INFO $ "dprox " <> toLogStr (showVersion version) <> " started"
let defaultPort = 53
fallbackServer = Server Nothing "8.8.8.8" Nothing
server = [ (fromMaybe "" mDomain, (ip, fromMaybe defaultPort mPort))
| Server mDomain ip mPort <- fallbackServer : conf
]
address = [(domain, [ip]) | Address domain ip <- conf]
hosts = [(domain, [ip]) | Hosts domain ip <- conf]
bogusnx = [ip | BogusNX ip <- conf]
ipset = [ipmask | IPSet ipmask <- conf]
serverRoute = newDomainRoute (const id) server
serverAddressSet = S.fromList $ F.toList serverRoute
addressRoute = newDomainRoute (++) address
hostsRoute = newDomainRoute (++) hosts
bogusnxSet = S.fromList bogusnx
ipsetServerPort = fmap (fromMaybe defaultPort) <$> ipsetServer
resolvConfs = [ (addr, rc)
| addr@(host, port) <- S.toList serverAddressSet ++ maybeToList ipsetServerPort
, host /= invalidIPAddress
, let rsinfo = if port == defaultPort
then DNS.RCHostName (show host)
else DNS.RCHostPort (show host) port
, let rc = DNS.defaultResolvConf {
DNS.resolvCache = Nothing,
DNS.resolvInfo = rsinfo
}
]
logger INFO $ "read " <> toLogStr (length server) <> " server configs"
logger INFO $ "read " <> toLogStr (length address) <> " address configs"
logger INFO $ "read " <> toLogStr (length hosts) <> " hosts configs"
logger INFO $ "read " <> toLogStr (length bogusnx) <> " bogus-nxdomain configs"
logger INFO $ "read " <> toLogStr (length ipset) <> " ipset configs"
let (bport, bhost) = (fromIntegral $ fromMaybe defaultPort localPort, fromMaybe "*6" listenAddress)
sock <- bindPortUDP bport bhost
logger INFO $ "bind to " <> toLogStr (show bhost) <> ":" <> toLogStr bport
resolvSeeds <- forM resolvConfs $ \(k, v) -> do
logger INFO $ "creating resolver: " <> toLogStr (show $ fst k) <> ":" <> toLogStr (show $ snd k)
rs <- DNS.makeResolvSeed v
return (k, rs)
resolverCache <- makeResolverCache cacheSize cacheTTL
ipsetCache <- newCache 4096 maxBound
let processWithResolver resolver = forever $ do
(bs, addr) <- recvFrom sock (fromIntegral DNS.maxUdpSize)
forkIO $ do
case parseDNS bs of
Left err -> logger DEBUG $ "dns parse error: " <> toLogStr (show err) <> " from: " <> toLogStr (show addr)
Right q -> do
logger TRACE $ "dns request from " <> toLogStr (show addr) <> ": " <> toLogStr (show $ DNS.question q)
resp <- processDNS resolver q
case resp of
Right resp' -> void $ sendTo sock resp' addr
Left err -> do
logger DEBUG $ "dns process error: " <> toLogStr (show err) <> " from: " <> toLogStr (show addr)
createResolvers ((k,v):xs) m = DNS.withResolver v $ \rs ->
createResolvers xs (M.insert k (DNS.lookup rs) m)
createResolvers [] m = let serverRoute' = fmap (`M.lookup`m) serverRoute
ipsetResolver = join $ fmap (`M.lookup`m) ipsetServerPort
resolver = handleIPSet ipset ipsetMatch ipsetResolver ipsetCache $
resolverCache $
handleAddressAndHosts addressRoute hostsRoute $
handleBogusNX bogusnxSet $
handleServer serverRoute'
in processWithResolver resolver
createResolvers resolvSeeds M.empty