From 364735d8f7cbc78528517faeccac606813ef9998 Mon Sep 17 00:00:00 2001 From: Michael Orlitzky Date: Wed, 21 Apr 2010 20:48:59 -0400 Subject: [PATCH] Moved most of the CIDR code out of Main and in to a new Cidr module. Created a Cidr data type to handle four-tuples of octets. Modified all of the function signatures to use the new Cidr data type. --- src/Cidr.hs | 185 ++++++++++++++++++++++++++++++++++++++++++++++++++++ src/Main.hs | 139 +++++++-------------------------------- 2 files changed, 209 insertions(+), 115 deletions(-) create mode 100644 src/Cidr.hs diff --git a/src/Cidr.hs b/src/Cidr.hs new file mode 100644 index 0000000..a2aed97 --- /dev/null +++ b/src/Cidr.hs @@ -0,0 +1,185 @@ +module Cidr +( Cidr, + from_string, + min_first_octet, + max_first_octet, + min_second_octet, + max_second_octet, + min_third_octet, + max_third_octet, + min_fourth_octet, + max_fourth_octet +) where + +import Data.Char (digitToInt, intToDigit) +import Numeric (readInt, showIntAtBase) +import ListUtils + +type Maskbits = Int +type Octet = Int +type OctetList = (Octet, Octet, Octet, Octet) +type BaseTwoOctetList = (String, String, String, String) + +data Cidr = Cidr { octet1 :: Octet, + octet2 :: Octet, + octet3 :: Octet, + octet4 :: Octet, + maskbits :: Maskbits } + deriving (Show) + +first :: (a,b,c,d) -> a +first (w,_,_,_) = w + +second :: (a,b,c,d) -> b +second (_,x,_,_) = x + +third :: (a,b,c,d) -> c +third (_,_,y,_) = y + +fourth :: (a,b,c,d) -> d +fourth (_,_,_,z) = z + +min_first_octet :: Cidr -> Octet +min_first_octet cidr = first (min_octets cidr) + +min_second_octet :: Cidr -> Octet +min_second_octet cidr = second (min_octets cidr) + +min_third_octet :: Cidr -> Octet +min_third_octet cidr = third (min_octets cidr) + +min_fourth_octet :: Cidr -> Octet +min_fourth_octet cidr = fourth (min_octets cidr) + +max_first_octet :: Cidr -> Octet +max_first_octet cidr = first (max_octets cidr) + +max_second_octet :: Cidr -> Octet +max_second_octet cidr = second (max_octets cidr) + +max_third_octet :: Cidr -> Octet +max_third_octet cidr = third (max_octets cidr) + +max_fourth_octet :: Cidr -> Octet +max_fourth_octet cidr = fourth (max_octets cidr) + + +-- Returns the mask portion of a CIDR address. That is, everything +-- after the trailing slash. +maskbits_from_string :: String -> Maskbits +maskbits_from_string s = read ((splitWith (`elem` "/") s) !! 1) + + +-- Takes an IP address String in CIDR notation, and returns a list of +-- its octets (converted to Int). +octets_from_string :: String -> [Octet] +octets_from_string s = map read (take 4 (splitWith (`elem` "./") s)) + + +from_string :: String -> Cidr +from_string s = Cidr (octs !! 0) (octs !! 1) (octs !! 2) (octs !! 3) mbits + where + octs = octets_from_string s + mbits = maskbits_from_string s + + +-- The base_two_to_base_ten function requires a way to determine +-- whether or not the character it's currently parsing is valid. This +-- should do it. +is_binary_digit :: Char -> Bool +is_binary_digit c = + if c `elem` ['0','1'] then + True + else + False + + +-- Takes an Int, and returns its base-two representation as a String. +base_two :: Int -> String +base_two n = showIntAtBase 2 intToDigit n "" + + +-- Takes a set of octets, and converts them to base-two +-- individually. The results are then zero-padded on the left to 8 +-- characters, and concatenated together. +octets_base_two :: Cidr -> String +octets_base_two cidr = + s1 ++ s2 ++ s3 ++ s4 + where + s1 = ((pad_left_to 8 '0') . base_two) (octet1 cidr) + s2 = ((pad_left_to 8 '0') . base_two) (octet2 cidr) + s3 = ((pad_left_to 8 '0') . base_two) (octet3 cidr) + s4 = ((pad_left_to 8 '0') . base_two) (octet4 cidr) + + +base_two_octetlist_to_octetlist :: BaseTwoOctetList -> OctetList +base_two_octetlist_to_octetlist b2ol = + (oct1, oct2, oct3, oct4) + where + oct1 = base_two_to_base_ten (first b2ol) + oct2 = base_two_to_base_ten (second b2ol) + oct3 = base_two_to_base_ten (third b2ol) + oct4 = base_two_to_base_ten (fourth b2ol) + + +-- Convert a base-two String to an Int. +base_two_to_base_ten :: String -> Int +base_two_to_base_ten s = + if (length parsed) == 0 then + 0 + else + fst (parsed !! 0) + where + parsed = readInt 2 is_binary_digit digitToInt s + + +-- Returns the minimum address (as a base-two string) satisfying the +-- given CIDR string. +min_base_two_address :: Cidr -> String +min_base_two_address cidr = + pad_right_to 32 '0' netpart + where + netpart = take (maskbits cidr) (octets_base_two cidr) + + +-- Returns the maximum address (as a base-two string) satisfying the +-- given CIDR string. +max_base_two_address :: Cidr -> String +max_base_two_address cidr = + pad_right_to 32 '1' netpart + where + netpart = take (maskbits cidr) (octets_base_two cidr) + + +-- The octet components of min_base_two_address, as a base-two String. +min_base_two_octets :: Cidr -> BaseTwoOctetList +min_base_two_octets cidr = + (oct1, oct2, oct3, oct4) + where + addr = min_base_two_address cidr + oct1 = fst (splitAt 8 addr) + oct2 = fst (splitAt 8 (snd (splitAt 8 addr))) + oct3 = fst (splitAt 8 (snd (splitAt 16 addr))) + oct4 = snd (splitAt 24 addr) + + +-- The octet components of max_base_two_address, as a base-two String. +max_base_two_octets :: Cidr -> BaseTwoOctetList +max_base_two_octets cidr = + (oct1, oct2, oct3, oct4) + where + addr = max_base_two_address cidr + oct1 = fst (splitAt 8 addr) + oct2 = fst (splitAt 8 (snd (splitAt 8 addr))) + oct3 = fst (splitAt 8 (snd (splitAt 16 addr))) + oct4 = snd (splitAt 24 addr) + + +-- The octet components of min_base_two_address, as Ints. +min_octets :: Cidr -> OctetList +min_octets cidr = base_two_octetlist_to_octetlist (min_base_two_octets cidr) + + +-- The octet components of max_base_two_address, as Ints. +max_octets :: Cidr -> OctetList +max_octets cidr = base_two_octetlist_to_octetlist (max_base_two_octets cidr) diff --git a/src/Main.hs b/src/Main.hs index 3eb4c2a..c875209 100644 --- a/src/Main.hs +++ b/src/Main.hs @@ -1,110 +1,17 @@ -import Data.Char (digitToInt, intToDigit) -import Data.List (concatMap, intercalate, intersperse, splitAt) -import Numeric (readInt, showIntAtBase) +import Data.List (intercalate, intersperse) import System.Exit (exitFailure) import Text.Regex.Posix -import ListUtils - --- Takes an IP address in CIDR notation, and returns a list of its --- octets (converted to Int). -octets :: String -> [Int] -octets cidr = map read (take 4 (splitWith (`elem` "./") cidr)) - - --- Returns the mask portion of a CIDR address. That is, everything --- after the trailing slash. -maskbits :: String -> Int -maskbits cidr = read ((splitWith (`elem` "/") cidr) !! 1) - - --- Takes an Int, and returns its base-two representation as a String. -base_two :: Int -> String -base_two n = showIntAtBase 2 intToDigit n "" - - --- Takes a set of octets, and converts them to base-two --- individually. The results are then zero-padded on the left to 8 --- characters, and concatenated together. -octets_base_two :: [Int] -> String -octets_base_two octet_list = - concatMap ((pad_left_to 8 '0') .base_two) octet_list - - --- Returns the minimum address (as a base-two string) satisfying the --- given CIDR string. -min_base_two_address :: String -> String -min_base_two_address cidr = - pad_right_to 32 '0' netpart - where - netpart = take (maskbits cidr) (octets_base_two (octets cidr)) - - --- Returns the maximum address (as a base-two string) satisfying the --- given CIDR string. -max_base_two_address :: String -> String -max_base_two_address cidr = - pad_right_to 32 '1' netpart - where - netpart = take (maskbits cidr) (octets_base_two (octets cidr)) - - --- The octet components of min_base_two_address, as a base-two String. -min_base_two_octets :: String -> [String] -min_base_two_octets cidr = - [octet1, octet2, octet3, octet4] - where - addr = min_base_two_address cidr - octet1 = fst (splitAt 8 addr) - octet2 = fst (splitAt 8 (snd (splitAt 8 addr))) - octet3 = fst (splitAt 8 (snd (splitAt 16 addr))) - octet4 = snd (splitAt 24 addr) - - --- The octet components of max_base_two_address, as a base-two String. -max_base_two_octets :: String -> [String] -max_base_two_octets cidr = - [octet1, octet2, octet3, octet4] - where - addr = max_base_two_address cidr - octet1 = fst (splitAt 8 addr) - octet2 = fst (splitAt 8 (snd (splitAt 8 addr))) - octet3 = fst (splitAt 8 (snd (splitAt 16 addr))) - octet4 = snd (splitAt 24 addr) - - --- The octet components of min_base_two_address, as Ints. -min_octets :: String -> [Int] -min_octets cidr = - map base_two_to_base_ten (min_base_two_octets cidr) - - --- The octet components of max_base_two_address, as Ints. -max_octets :: String -> [Int] -max_octets cidr = - map base_two_to_base_ten (max_base_two_octets cidr) - - --- The base_two_to_base_ten function requires a way to determine --- whether or not the character it's currently parsing is valid. This --- should do it. -is_binary_digit :: Char -> Bool -is_binary_digit c = - if c `elem` ['0','1'] then - True - else - False - - --- Convert a base-two String to an Int. -base_two_to_base_ten :: String -> Int -base_two_to_base_ten s = - if (length parsed) == 0 then - 0 - else - fst (parsed !! 0) - where - parsed = readInt 2 is_binary_digit digitToInt s +import Cidr (Cidr, + from_string, + min_first_octet, + min_second_octet, + min_third_octet, + min_fourth_octet, + max_first_octet, + max_second_octet, + max_third_octet, + max_fourth_octet) -- A regular expression that matches a non-address character. @@ -128,7 +35,8 @@ addr_barrier x = non_addr_char ++ x ++ non_addr_char -- 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 :: String -> String +cidr_to_regex :: Cidr.Cidr -> String cidr_to_regex cidr = addr_barrier (intercalate "\\." [range1, range2, range3, range4]) where @@ -136,14 +44,14 @@ cidr_to_regex cidr = range2 = numeric_range min2 max2 range3 = numeric_range min3 max3 range4 = numeric_range min4 max4 - min1 = (min_octets cidr) !! 0 - min2 = (min_octets cidr) !! 1 - min3 = (min_octets cidr) !! 2 - min4 = (min_octets cidr) !! 3 - max1 = (max_octets cidr) !! 0 - max2 = (max_octets cidr) !! 1 - max3 = (max_octets cidr) !! 2 - max4 = (max_octets cidr) !! 3 + min1 = min_first_octet cidr + min2 = min_second_octet cidr + min3 = min_third_octet cidr + min4 = min_fourth_octet cidr + max1 = max_first_octet cidr + max2 = max_second_octet cidr + max3 = max_third_octet cidr + max4 = max_fourth_octet cidr -- Will return True if the passed String is in CIDR notation, False @@ -182,8 +90,9 @@ validate_or_die cidr = do main :: IO () main = do input <- getContents - let cidrs = lines input - mapM validate_or_die cidrs + let cidr_strings = lines input + mapM validate_or_die cidr_strings + let cidrs = map Cidr.from_string cidr_strings let regexes = map cidr_to_regex cidrs putStrLn $ alternate regexes -- 2.43.2