X-Git-Url: http://gitweb.michael.orlitzky.com/?a=blobdiff_plain;f=src%2FCidr.hs;h=8fc014f6cf5b062f8ae019d3b990c22a9604e9b8;hb=a3c4fbd855c182390f39cdf88de36d7cb0ea69d5;hp=553bd15c06061daf2928fce8ae49dee71f56c1c8;hpb=706e492881f05238ace00fefc6ec9cb0000ea2e9;p=hath.git diff --git a/src/Cidr.hs b/src/Cidr.hs index 553bd15..8fc014f 100644 --- a/src/Cidr.hs +++ b/src/Cidr.hs @@ -1,193 +1,382 @@ module Cidr -( Cidr, - from_string, - is_valid_cidr, - min_first_octet, - max_first_octet, - min_second_octet, - max_second_octet, - min_third_octet, - max_third_octet, - min_fourth_octet, - max_fourth_octet +( Cidr(..), + cidr_from_string, + cidr_tests, + combine_all, + contains, + contains_proper, + max_octet1, + max_octet2, + max_octet3, + max_octet4, + min_octet1, + min_octet2, + min_octet3, + min_octet4, + prop_all_cidrs_contain_themselves, + prop_contains_proper_intransitive ) where -import Data.Char (digitToInt, intToDigit) -import Numeric (readInt, showIntAtBase) -import Text.Regex.Posix +import Data.List (nubBy) +import Test.HUnit +import Test.QuickCheck +import qualified Bit as B +import IPv4Address import ListUtils +import Maskable +import Maskbits +import Octet -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) +data Cidr = None | Cidr { ipv4address :: IPv4Address, + maskbits :: Maskbits } + deriving (Eq) --- Will return True if the passed String is in CIDR notation, False --- otherwise. -is_valid_cidr :: String -> Bool -is_valid_cidr cidr = cidr =~ "([0-9]{1,3}\\.){3}[0-9]{1,3}/[0-9]{1,2}" -first :: (a,b,c,d) -> a -first (w,_,_,_) = w +instance Show Cidr where + show Cidr.None = "None" + show cidr = (show (ipv4address cidr)) ++ "/" ++ (show (maskbits cidr)) -second :: (a,b,c,d) -> b -second (_,x,_,_) = x -third :: (a,b,c,d) -> c -third (_,_,y,_) = y +instance Arbitrary Cidr where + arbitrary = do + ipv4 <- arbitrary :: Gen IPv4Address + mask <- arbitrary :: Gen Maskbits + return (Cidr ipv4 mask) -fourth :: (a,b,c,d) -> d -fourth (_,_,_,z) = z + coarbitrary _ = variant 0 -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) +-- Two CIDR ranges are equivalent if they have the same network bits +-- and the masks are the same. +equivalent :: Cidr -> Cidr -> Bool +equivalent Cidr.None Cidr.None = True +equivalent Cidr.None _ = False +equivalent _ Cidr.None = False +equivalent (Cidr addr1 mbits1) (Cidr addr2 mbits2) = + (mbits1 == mbits2) && ((apply_mask addr1 mbits1 B.Zero) == (apply_mask addr2 mbits2 B.Zero)) -min_third_octet :: Cidr -> Octet -min_third_octet cidr = third (min_octets cidr) +-- Returns the mask portion of a CIDR address. That is, everything +-- after the trailing slash. +maskbits_from_cidr_string :: String -> Maskbits +maskbits_from_cidr_string s = + maskbits_from_string ((splitWith (`elem` "/") s) !! 1) -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) +-- Takes an IP address String in CIDR notation, and returns a list of +-- its octets (as Ints). +octets_from_cidr_string :: String -> [Octet] +octets_from_cidr_string s = + map octet_from_string (take 4 (splitWith (`elem` "./") s)) -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) +cidr_from_string :: String -> Cidr +cidr_from_string s + | addr == IPv4Address.None = Cidr.None + | mbits == Maskbits.None = Cidr.None + | otherwise = Cidr addr mbits + where + addr = ipv4address_from_octets (oct1) (oct2) (oct3) (oct4) + oct1 = (octs !! 0) + oct2 = (octs !! 1) + oct3 = (octs !! 2) + oct4 = (octs !! 3) + octs = octets_from_cidr_string s + mbits = maskbits_from_cidr_string s + + + +min_host :: Cidr -> IPv4Address +min_host Cidr.None = IPv4Address.None +min_host (Cidr IPv4Address.None _) = IPv4Address.None +min_host (Cidr _ Maskbits.None) = IPv4Address.None +min_host (Cidr addr mask) = apply_mask addr mask B.Zero + + +max_host :: Cidr -> IPv4Address +max_host Cidr.None = IPv4Address.None +max_host (Cidr IPv4Address.None _) = IPv4Address.None +max_host (Cidr _ Maskbits.None) = IPv4Address.None +max_host (Cidr addr mask) = apply_mask addr mask B.One + + +min_octet1 :: Cidr -> Octet +min_octet1 cidr = octet1 (min_host cidr) + +min_octet2 :: Cidr -> Octet +min_octet2 cidr = octet2 (min_host cidr) + +min_octet3 :: Cidr -> Octet +min_octet3 cidr = octet3 (min_host cidr) + +min_octet4 :: Cidr -> Octet +min_octet4 cidr = octet4 (min_host cidr) + +max_octet1 :: Cidr -> Octet +max_octet1 cidr = octet1 (max_host cidr) + +max_octet2 :: Cidr -> Octet +max_octet2 cidr = octet2 (max_host cidr) + +max_octet3 :: Cidr -> Octet +max_octet3 cidr = octet3 (max_host cidr) + +max_octet4 :: Cidr -> Octet +max_octet4 cidr = octet4 (max_host cidr) + + + +-- Return true if the first argument (a CIDR range) contains the +-- second (another CIDR range). There are a lot of ways we can be fed +-- junk here. For lack of a better alternative, just return False when +-- we are given nonsense. +contains :: Cidr -> Cidr -> Bool +contains Cidr.None _ = False +contains _ Cidr.None = False +contains (Cidr _ Maskbits.None) _ = False +contains (Cidr IPv4Address.None _) _ = False +contains _ (Cidr _ Maskbits.None) = False +contains _ (Cidr IPv4Address.None _) = False + +-- If the number of bits in the network part of the first address is +-- larger than the number of bits in the second, there is no way that +-- the first range can contain the second. For, if the number of +-- network bits is larger, then the number of host bits must be +-- smaller, and if cidr1 has fewer hosts than cidr2, cidr1 most +-- certainly does not contain cidr2. +-- +-- On the other hand, if the first argument (cidr1) has fewer (or the +-- same number of) network bits as the second, it can contain the +-- second. In this case, we need to check that every host in cidr2 is +-- contained in cidr1. If a host in cidr2 is contained in cidr1, then +-- at least mbits1 of an address in cidr2 will match cidr1. For +-- example, +-- +-- cidr1 = 192.168.1.0/23, cidr2 = 192.168.1.100/24 +-- +-- Here, cidr2 contains all of 192.168.1.0 through +-- 192.168.1.255. However, cidr1 contains BOTH 192.168.0.0 through +-- 192.168.0.255 and 192.168.1.0 through 192.168.1.255. In essence, +-- what we want to check is that cidr2 "begins with" something that +-- cidr1 CAN begin with. Since cidr1 can begin with 192.168.1, and +-- cidr2 DOES, cidr1 contains cidr2.. +-- +-- The way that we check this is to apply cidr1's mask to cidr2's +-- address and see if the result is the same as cidr1's mask applied +-- to cidr1's address. +-- +contains (Cidr addr1 mbits1) (Cidr addr2 mbits2) + | mbits1 > mbits2 = False + | otherwise = addr1masked == addr2masked + where + addr1masked = apply_mask addr1 mbits1 B.Zero + addr2masked = apply_mask addr2 mbits1 B.Zero -max_fourth_octet :: Cidr -> Octet -max_fourth_octet cidr = fourth (max_octets cidr) +contains_proper :: Cidr -> Cidr -> Bool +contains_proper cidr1 cidr2 = + (cidr1 `contains` cidr2) && (not (cidr2 `contains` cidr1)) --- 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) +-- A CIDR range is redundant (with respect to the given list) if +-- another CIDR range in that list properly contains it. +redundant :: [Cidr] -> Cidr -> Bool +redundant cidrlist cidr = any ((flip contains_proper) cidr) cidrlist --- 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)) + +-- First, we look at all possible pairs of cidrs, and combine the +-- adjacent ones in to a new list. Then, we concatenate that list with +-- the original one, and filter out all of the redundancies. If two +-- adjacent Cidrs are combined into a larger one, they will be removed +-- in the second step since the larger Cidr must contain the smaller +-- two. +combine_all :: [Cidr] -> [Cidr] +combine_all cidrs = + combine_contained unique_cidrs + where + unique_cidrs = nubBy equivalent valid_cidr_combinations + valid_cidr_combinations = filter (/= Cidr.None) cidr_combinations + cidr_combinations = + cidrs ++ [ (combine_adjacent x y) | x <- cidrs, y <- cidrs ] + + +-- Take a list of CIDR ranges and filter out all of the ones that are +-- contained entirelt within some other range in the list. +combine_contained :: [Cidr] -> [Cidr] +combine_contained cidrs = + filter (not . (redundant cidrs)) cidrs + + +-- If the two Cidrs are not adjacent, return Cidr.None. Otherwise, +-- decrement the maskbits of cidr1 and return that; it will contain +-- both cidr1 and cidr2. +combine_adjacent :: Cidr -> Cidr -> Cidr +combine_adjacent cidr1 cidr2 + | not (adjacent cidr1 cidr2) = Cidr.None + | (maskbits cidr1 == Zero) = Cidr.None + | otherwise = cidr1 { maskbits = decrement (maskbits cidr1) } -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 +-- Determine whether or not two CIDR ranges are adjacent. If two +-- ranges lie consecutively within the IP space, they can be +-- combined. For example, 10.1.0.0/24 and 10.0.1.0/24 are adjacent, +-- and can be combined in to 10.1.0.0/23. +adjacent :: Cidr -> Cidr -> Bool +adjacent Cidr.None _ = False +adjacent _ Cidr.None = False +adjacent cidr1 cidr2 + | mbits1 /= mbits2 = False + | mbits1 == Maskbits.Zero = False -- They're equal. + | otherwise = (mbits1 == (most_sig_bit_different addr1 addr2)) + where + addr1 = ipv4address cidr1 + addr2 = ipv4address cidr2 + mbits1 = maskbits cidr1 + mbits2 = maskbits cidr2 --- 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 +-- HUnit Tests + +test_equality1 :: Test +test_equality1 = + TestCase $ assertEqual "10.1.1.0/23 equals itself" True (cidr1 == cidr1) + where + cidr1 = cidr_from_string "10.1.1.0/23" + + +test_contains1 :: Test +test_contains1 = + TestCase $ assertEqual "10.1.1.0/23 contains 10.1.1.0/24" True (cidr1 `contains` cidr2) 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) + cidr1 = cidr_from_string "10.1.1.0/23" + cidr2 = cidr_from_string "10.1.1.0/24" -base_two_octetlist_to_octetlist :: BaseTwoOctetList -> OctetList -base_two_octetlist_to_octetlist b2ol = - (oct1, oct2, oct3, oct4) +test_contains2 :: Test +test_contains2 = + TestCase $ assertEqual "10.1.1.0/23 contains itself" True (cidr1 `contains` cidr1) 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) + cidr1 = cidr_from_string "10.1.1.0/23" + + +test_contains_proper1 :: Test +test_contains_proper1 = + TestCase $ assertEqual "10.1.1.0/23 contains 10.1.1.0/24 properly" True (cidr1 `contains_proper` cidr2) where - parsed = readInt 2 is_binary_digit digitToInt s + cidr1 = cidr_from_string "10.1.1.0/23" + cidr2 = cidr_from_string "10.1.1.0/24" --- 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 +test_contains_proper2 :: Test +test_contains_proper2 = + TestCase $ assertEqual "10.1.1.0/23 does not contain itself properly" False (cidr1 `contains_proper` cidr1) where - netpart = take (maskbits cidr) (octets_base_two cidr) + cidr1 = cidr_from_string "10.1.1.0/23" --- 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 +test_adjacent1 :: Test +test_adjacent1 = + TestCase $ assertEqual "10.1.0.0/24 is adjacent to 10.1.1.0/24" True (cidr1 `adjacent` cidr2) where - netpart = take (maskbits cidr) (octets_base_two cidr) + cidr1 = cidr_from_string "10.1.0.0/24" + cidr2 = cidr_from_string "10.1.1.0/24" --- 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) +test_adjacent2 :: Test +test_adjacent2 = + TestCase $ assertEqual "10.1.0.0/23 is not adjacent to 10.1.0.0/24" False (cidr1 `adjacent` cidr2) 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) + cidr1 = cidr_from_string "10.1.0.0/23" + cidr2 = cidr_from_string "10.1.0.0/24" --- 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) +test_adjacent3 :: Test +test_adjacent3 = + TestCase $ assertEqual "10.1.0.0/24 is not adjacent to 10.2.5.0/24" False (cidr1 `adjacent` cidr2) 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) + cidr1 = cidr_from_string "10.1.0.0/24" + cidr2 = cidr_from_string "10.2.5.0/24" --- 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) +test_adjacent4 :: Test +test_adjacent4 = + TestCase $ assertEqual "10.1.1.0/24 is not adjacent to 10.1.2.0/24" False (cidr1 `adjacent` cidr2) + where + cidr1 = cidr_from_string "10.1.1.0/24" + cidr2 = cidr_from_string "10.1.2.0/24" --- 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) +test_combine_contained1 :: Test +test_combine_contained1 = + TestCase $ assertEqual "10.0.0.0/8, 10.1.0.0/16, and 10.1.1.0/24 combine to 10.0.0.0/8" expected_cidrs (combine_contained test_cidrs) + where + cidr1 = cidr_from_string "10.0.0.0/8" + cidr2 = cidr_from_string "10.1.0.0/16" + cidr3 = cidr_from_string "10.1.1.0/24" + expected_cidrs = [cidr1] + test_cidrs = [cidr1, cidr2, cidr3] + + +test_combine_contained2 :: Test +test_combine_contained2 = + TestCase $ assertEqual "192.168.3.0/23 does not contain 192.168.1.0/24" [cidr1, cidr2] (combine_contained [cidr1, cidr2]) + where + cidr1 = cidr_from_string "192.168.3.0/23" + cidr2 = cidr_from_string "192.168.1.0/24" + + +test_combine_all1 :: Test +test_combine_all1 = + TestCase $ assertEqual "10.0.0.0/24 is adjacent to 10.0.1.0/24 and 10.0.3.0/23 contains 10.0.2.0/24" expected_cidrs (combine_all test_cidrs) + where + cidr1 = cidr_from_string "10.0.0.0/24" + cidr2 = cidr_from_string "10.0.1.0/24" + cidr3 = cidr_from_string "10.0.2.0/24" + cidr4 = cidr_from_string "10.0.3.0/23" + cidr5 = cidr_from_string "10.0.0.0/23" + expected_cidrs = [cidr4, cidr5] + test_cidrs = [cidr1, cidr2, cidr3, cidr4] + + +test_combine_all2 :: Test +test_combine_all2 = + TestCase $ assertEqual "127.0.0.1/32 combines with itself recursively" expected_cidrs (combine_all test_cidrs) + where + cidr1 = cidr_from_string "127.0.0.1/32" + expected_cidrs = [cidr1] + test_cidrs = [cidr1, cidr1, cidr1, cidr1, cidr1] + + +cidr_tests :: [Test] +cidr_tests = [ test_equality1, + test_contains1, + test_contains2, + test_contains_proper1, + test_contains_proper2, + test_adjacent1, + test_adjacent2, + test_adjacent3, + test_adjacent4, + test_combine_contained1, + test_combine_contained2, + test_combine_all1, + test_combine_all2 + ] + + +-- QuickCheck Tests +prop_all_cidrs_contain_themselves :: Cidr -> Bool +prop_all_cidrs_contain_themselves cidr1 = cidr1 `contains` cidr1 + + +-- If cidr1 properly contains cidr2, then by definition cidr2 +-- does not properly contain cidr1. +prop_contains_proper_intransitive :: Cidr -> Cidr -> Property +prop_contains_proper_intransitive cidr1 cidr2 = + (cidr1 `contains_proper` cidr2) ==> + (not (cidr2 `contains_proper` cidr1))