blob: fa1b6f71ca5efbd98321838be9ec2144831290ec (
plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
|
import Network.Socket
import qualified Network.BSD as BSD
import ControlMaybe
import Control.Exception ({-evaluate,-}handle,SomeException(..),bracketOnError,ErrorCall(..))
import System.IO.Error (isDoesNotExistError)
import System.Endian
import Data.List (nub)
import qualified Data.Text as Text
import GetHostByAddr (getHostByAddr)
import Control.Concurrent
import Control.Concurrent.STM
import Control.Monad
import System.Environment
unmap6mapped4 addr@(SockAddrInet6 port _ (0,0,0xFFFF,a) _) =
SockAddrInet port (toBE32 a)
unmap6mapped4 addr = addr
make6mapped4 addr@(SockAddrInet6 {}) = addr
make6mapped4 addr@(SockAddrInet port a) = SockAddrInet6 port 0 (0,0,0xFFFF,fromBE32 a) 0
reverseResolve addr =
handleIO_ (return []) $ do
ent <- getHostByAddr (unmap6mapped4 addr) -- AF_UNSPEC addr
let names = BSD.hostName ent : BSD.hostAliases ent
return $ map Text.pack $ nub names
forwardResolve addrtext = do
r <- atomically newEmptyTMVar
mvar <- atomically newEmptyTMVar
rt <- forkOS $ resolver r mvar
tt <- forkIO $ timer r rt
atomically $ putTMVar mvar tt
atomically $ readTMVar r
where
resolver r mvar = do
xs <- handle (\e -> let _ = isDoesNotExistError e in return [])
$ do fmap (map $ make6mapped4 . addrAddress) $
getAddrInfo (Just $ defaultHints { addrFlags = [ AI_CANONNAME, AI_V4MAPPED ]})
(Just $ Text.unpack $ strip_brackets addrtext)
(Just "5269")
did <- atomically $ tryPutTMVar r (nub xs)
when did $ do
tt <- atomically $ readTMVar mvar
throwTo tt (ErrorCall "Interrupted delay")
return ()
timer r rt = do
handle (\(ErrorCall _)-> return ()) $ do
threadDelay 2000000
did <- atomically $ tryPutTMVar r []
when did $ do
putStrLn $ "timeout resolving: "++show addrtext
killThread rt
strip_brackets s =
case Text.uncons s of
Just ('[',t) -> Text.takeWhile (/=']') t
_ -> s
main = do
args <- getArgs
forM args $ \arg -> do
putStrLn $ arg ++ ":"
let targ = Text.pack arg
addrs <- forwardResolve targ
putStrLn $ " forward: " ++ show addrs
forM addrs $ \addr -> do
names <- reverseResolve addr
putStrLn $ " reverse "++show addr++": "++show names
return ()
|
