Sorry everyone for cross posting. I was trying to send it on some other forum but some how i missed the email id. Regards Mukesh Tiwari
On Oct 16, 5:47 pm, mukesh tiwari <mukeshtiwari.ii...@gmail.com> wrote: > Hello everyone > I am writing application which reads pcap file like wireshark in pure > haskell but there is some thing missing. I read this > filehttp://www.viste.com/Linux/Server/WireShark/libpcapformat.pdf<http://www.google.com/url?sa=D&q=http://www.viste.com/Linux/Server/Wi...> > > and it say that first 24 bytes are global headers , after that every packet > contains pcap local header and data. What i am trying to do is , > first trying to get the bytes of data in each packet by reading the third > field incl_len in local header but my code is not behaving as it suppose . I > am not getting the list of parsed packets . My test libcap file > ishttp://wiki.wireshark.org/SampleCaptures?action=AttachFile&do=view&ta...<http://www.google.com/url?sa=D&q=http://wiki.wireshark.org/SampleCapt...> > > --http://www.viste.com/Linux/Server/WireShark/libpcapformat.pdf<http://www.google.com/url?sa=D&q=http://www.viste.com/Linux/Server/Wi...> > > --http://hackage.haskell.org/packages/archive/bytestring/0.9.0.4/doc/<http://www.google.com/url?sa=D&q=http://hackage.haskell.org/packages/...> > > html/Data-ByteString-Lazy.html > import Data.List > import qualified Data.ByteString.Lazy as BS > import qualified Data.ByteString.Lazy.Char8 as B > import Control.Monad > import Text.Printf > import Data.Word > import Data.Char > import System.Time > import Numeric > import System.Environment > > hexTodec :: BS.ByteString -> Integer > hexTodec lst = read $ "0x" ++ ( concatMap ( \x -> showHex x "" ) > $ BS.unpack lst ) > > parseFile :: BS.ByteString -> Bool -> IO [ BS.ByteString ] > parseFile xs revflag > | BS.null xs = return [] > | otherwise = do > let ind =if revflag then hexTodec . BS.reverse . BS.take 4 . > BS.drop 8 $ xs > else hexTodec . BS.take 4 . BS.drop 8 $ xs > print ind > let ( x , ys ) = BS.splitAt ( fromIntegral ind ) xs > --BS.putStrLn $ x > tmp <- parseFile ys revflag > return $ x : tmp > > main = do > [ file ] <- getArgs > contents <- BS.readFile file > let ( a , rest ) = BS.splitAt 24 contents --strip global header > > let revflag = case BS.unpack $ BS.take 4 a of > [ 0xd4 , 0xc3 , 0xb2 , 0xa1 ] -> True > _ -> False > p <- parseFile rest revflag > print $ p !! 0 > BS.putStr $ p !! 0 > > Regards > Mukesh Tiwari > > _______________________________________________ > Haskell-Cafe mailing list > Haskell-C...@haskell.orghttp://www.haskell.org/mailman/listinfo/haskell-cafe _______________________________________________ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
