import Data.List (intercalate, intersperse) import System.Exit (ExitCode(..), exitWith) import System.IO (stderr, hPutStrLn) import Cidr (Cidr(..), cidr_from_string, combine_all) import CommandLine (help_set, help_text, input_function, Mode(..), parse_errors, parse_mode) import IPv4Address import Octet -- Some exit codes, used in the ExitFailure constructor. exit_invalid_cidr :: Int exit_invalid_cidr = 1 exit_args_parse_failed :: Int exit_args_parse_failed = 2 -- A regular expression that matches a non-address character. non_addr_char :: String non_addr_char = "[^\\.0-9]" -- Add non_addr_chars on either side of the given String. This -- prevents (for example) the regex '127.0.0.1' from matching -- '127.0.0.100'. addr_barrier :: String -> String addr_barrier x = non_addr_char ++ x ++ non_addr_char -- The magic happens here. We take a CIDR String as an argument, and -- return the equivalent regular expression. We do this as follows: -- -- 1. Compute the minimum possible value of each octet. -- 2. Compute the maximum possible value of each octet. -- 3. Generate a regex matching every value between those min and -- max values. -- 4. Join the regexes from step 3 with regexes matching periods. -- 5. Stick an address boundary on either side of the result. --cidr_to_regex :: String -> String cidr_to_regex :: Cidr.Cidr -> String cidr_to_regex cidr = addr_barrier (intercalate "\\." [range1, range2, range3, range4]) where range1 = numeric_range min1 max1 range2 = numeric_range min2 max2 range3 = numeric_range min3 max3 range4 = numeric_range min4 max4 min1 = octet_to_int (min_octet1 (ipv4address cidr) (maskbits cidr)) min2 = octet_to_int (min_octet2 (ipv4address cidr) (maskbits cidr)) min3 = octet_to_int (min_octet3 (ipv4address cidr) (maskbits cidr)) min4 = octet_to_int (min_octet4 (ipv4address cidr) (maskbits cidr)) max1 = octet_to_int (max_octet1 (ipv4address cidr) (maskbits cidr)) max2 = octet_to_int (max_octet2 (ipv4address cidr) (maskbits cidr)) max3 = octet_to_int (max_octet3 (ipv4address cidr) (maskbits cidr)) max4 = octet_to_int (max_octet4 (ipv4address cidr) (maskbits cidr)) -- Take a list of Strings, and return a regular expression matching -- any of them. alternate :: [String] -> String alternate terms = "(" ++ (concat (intersperse "|" terms)) ++ ")" -- Take two Ints as parameters, and return a regex matching any -- integer between them (inclusive). numeric_range :: Int -> Int -> String numeric_range x y = alternate (map show [lower..upper]) where lower = minimum [x,y] upper = maximum [x,y] main :: IO () main = do -- First, check for any errors that occurred while parsing -- the command line options. errors <- CommandLine.parse_errors if not (null errors) then do hPutStrLn stderr (concat errors) putStrLn CommandLine.help_text exitWith (ExitFailure exit_args_parse_failed) else do -- Nothing -- Next, check to see if the 'help' option was passed to the -- program. If it was, display the help, and exit successfully. help_opt_set <- CommandLine.help_set if help_opt_set then do putStrLn CommandLine.help_text exitWith ExitSuccess else do -- Nothing -- The input function we receive here should know what to read. inputfunc <- (CommandLine.input_function) input <- inputfunc let cidr_strings = lines input let cidrs = map Cidr.cidr_from_string cidr_strings if (any (== Cidr.None) cidrs) then do putStrLn "Error: not valid CIDR notation." exitWith (ExitFailure exit_invalid_cidr) else do -- Nothing -- Get the mode of operation. mode <- CommandLine.parse_mode case mode of Regex -> do let regexes = map cidr_to_regex cidrs putStrLn $ alternate regexes Reduce -> do mapM (putStrLn . show) (combine_all cidrs) return ()