X-Git-Url: http://gitweb.michael.orlitzky.com/?a=blobdiff_plain;f=src%2FCidr.hs;h=a07117d5382842b94d23f87fe469c6831c997aad;hb=b4397616550eff1141b094f3fe0c38a1b3caffb7;hp=5c9fefd66e6714c5a6eeeb62718ccffd668345b8;hpb=0be56eaa64ab03adf3aa1f3f3c14a191c09045c8;p=hath.git diff --git a/src/Cidr.hs b/src/Cidr.hs index 5c9fefd..a07117d 100644 --- a/src/Cidr.hs +++ b/src/Cidr.hs @@ -3,13 +3,26 @@ module Cidr cidr_from_string, cidr_tests, combine_all, - prop_all_cidrs_contain_themselves + 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.List (nubBy) +import Data.Maybe (catMaybes, fromJust) import Test.HUnit import Test.QuickCheck +import qualified Bit as B import IPv4Address import ListUtils import Maskable @@ -17,13 +30,12 @@ import Maskbits import Octet -data Cidr = None | Cidr { ipv4address :: IPv4Address, - maskbits :: Maskbits } - deriving (Eq) +data Cidr = Cidr { ipv4address :: IPv4Address, + maskbits :: Maskbits } + instance Show Cidr where - show Cidr.None = "None" show cidr = (show (ipv4address cidr)) ++ "/" ++ (show (maskbits cidr)) @@ -33,147 +45,178 @@ instance Arbitrary Cidr where mask <- arbitrary :: Gen Maskbits return (Cidr ipv4 mask) - coarbitrary _ = variant 0 + +instance Eq Cidr where + cidr1 == cidr2 = (cidr1 `equivalent` cidr2) -- 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) == (apply_mask addr2 mbits2)) + (mbits1 == mbits2) && ((apply_mask addr1 mbits1 B.Zero) == (apply_mask addr2 mbits2 B.Zero)) -- 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) +maskbits_from_cidr_string :: String -> Maybe Maskbits +maskbits_from_cidr_string s + | length partlist == 2 = maskbits_from_string (partlist !! 1) + | otherwise = Nothing + where + partlist = (splitWith (`elem` "/") s) --- Takes an IP address String in CIDR notation, and returns a list of --- its octets (as Ints). +-- | 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)) + catMaybes $ map octet_from_string (take 4 (splitWith (`elem` "./") s)) -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 +-- | Return Nothing if we can't parse both maskbits and octets from +-- the string. +cidr_from_string :: String -> Maybe Cidr +cidr_from_string s = + case (octets_from_cidr_string s) of + [oct1, oct2, oct3, oct4] -> + case (maskbits_from_cidr_string s) of + Just mbits -> + Just $ Cidr (IPv4Address oct1 oct2 oct3 oct4) mbits + _ -> Nothing + _ -> Nothing --- 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. +min_host :: Cidr -> IPv4Address +min_host (Cidr addr mask) = apply_mask addr mask B.Zero + + +max_host :: Cidr -> IPv4Address +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. +-- +-- 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, +-- 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 +-- 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.. +-- 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. +-- 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 -> Cidr -> Bool contains (Cidr addr1 mbits1) (Cidr addr2 mbits2) - | mbits1 > mbits2 = False - | otherwise = addr1masked == addr2masked - where - addr1masked = apply_mask addr1 mbits1 - addr2masked = apply_mask addr2 mbits1 + | mbits1 > mbits2 = False + | otherwise = addr1masked == addr2masked + where + addr1masked = apply_mask addr1 mbits1 B.Zero + addr2masked = apply_mask addr2 mbits1 B.Zero contains_proper :: Cidr -> Cidr -> Bool contains_proper cidr1 cidr2 = - (cidr1 `contains` cidr2) && (not (cidr1 == cidr2)) + (cidr1 `contains` cidr2) && (not (cidr2 `contains` cidr1)) --- A CIDR range is redundant (with respect to the given list) if --- another CIDR range in that list properly contains it. +-- | 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 --- 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. +-- | 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. +-- +-- Once this is done, we see whether or not the result is different +-- than the argument that was passed in. If nothing changed, we're +-- done and return the list that was passed to us. However, if +-- something changed, we recurse and try to combine the list again. combine_all :: [Cidr] -> [Cidr] -combine_all cidrs = - combine_contained unique_cidrs +combine_all cidrs + | cidrs == (combine_contained unique_cidrs) = cidrs + | otherwise = combine_all (combine_contained unique_cidrs) where - unique_cidrs = nubBy equivalent valid_cidr_combinations - valid_cidr_combinations = filter (/= Cidr.None) cidr_combinations + unique_cidrs = nubBy equivalent cidr_combinations cidr_combinations = - cidrs ++ [ (combine_adjacent x y) | x <- cidrs, y <- cidrs ] + cidrs ++ (catMaybes [ (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. +-- | 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 + 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 +-- | 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 -> Maybe Cidr combine_adjacent cidr1 cidr2 - | not (adjacent cidr1 cidr2) = Cidr.None - | (maskbits cidr1 == Zero) = Cidr.None - | otherwise = cidr1 { maskbits = decrement (maskbits cidr1) } + | not (adjacent cidr1 cidr2) = Nothing + | (maskbits cidr1 == Zero) = Nothing + | otherwise = Just $ cidr1 { maskbits = decrement (maskbits cidr1) } --- 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. +-- | 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. @@ -190,95 +233,208 @@ adjacent cidr1 cidr2 -- HUnit Tests +test_min_host1 :: Test +test_min_host1 = + TestCase $ assertEqual "The minimum host in 10.0.0.0/24 is 10.0.0.0" + expected + actual + where + actual = show $ min_host (fromJust $ cidr_from_string "10.0.0.0/24") + expected = "10.0.0.0" + + +test_max_host1 :: Test +test_max_host1 = + TestCase $ assertEqual "The maximum host in 10.0.0.0/24 is 10.0.0.255" + expected + actual + where + actual = show $ max_host (fromJust $ cidr_from_string "10.0.0.0/24") + expected = "10.0.0.255" + + 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" + TestCase $ + assertEqual + "10.1.1.0/23 equals itself" + True + (cidr1 == cidr1) + where + cidr1 = fromJust $ 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 - cidr1 = cidr_from_string "10.1.1.0/23" - cidr2 = cidr_from_string "10.1.1.0/24" + TestCase $ + assertEqual + "10.1.1.0/23 contains 10.1.1.0/24" + True + (cidr1 `contains` cidr2) + where + cidr1 = fromJust $ cidr_from_string "10.1.1.0/23" + cidr2 = fromJust $ cidr_from_string "10.1.1.0/24" test_contains2 :: Test test_contains2 = - TestCase $ assertEqual "10.1.1.0/23 contains itself" True (cidr1 `contains` cidr1) - where - cidr1 = cidr_from_string "10.1.1.0/23" + TestCase $ + assertEqual + "10.1.1.0/23 contains itself" + True + (cidr1 `contains` cidr1) + where + cidr1 = fromJust $ 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 - cidr1 = cidr_from_string "10.1.1.0/23" - cidr2 = cidr_from_string "10.1.1.0/24" + TestCase $ + assertEqual + "10.1.1.0/23 contains 10.1.1.0/24 properly" + True + (cidr1 `contains_proper` cidr2) + where + cidr1 = fromJust $ cidr_from_string "10.1.1.0/23" + cidr2 = fromJust $ cidr_from_string "10.1.1.0/24" 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 - cidr1 = cidr_from_string "10.1.1.0/23" + TestCase $ + assertEqual + "10.1.1.0/23 does not contain itself properly" + False + (cidr1 `contains_proper` cidr1) + where + cidr1 = fromJust $ cidr_from_string "10.1.1.0/23" 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 - cidr1 = cidr_from_string "10.1.0.0/24" - cidr2 = cidr_from_string "10.1.1.0/24" + TestCase $ + assertEqual + "10.1.0.0/24 is adjacent to 10.1.1.0/24" + True + (cidr1 `adjacent` cidr2) + where + cidr1 = fromJust $ cidr_from_string "10.1.0.0/24" + cidr2 = fromJust $ cidr_from_string "10.1.1.0/24" 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 - cidr1 = cidr_from_string "10.1.0.0/23" - cidr2 = cidr_from_string "10.1.0.0/24" + TestCase $ + assertEqual + "10.1.0.0/23 is not adjacent to 10.1.0.0/24" + False + (cidr1 `adjacent` cidr2) + where + cidr1 = fromJust $ cidr_from_string "10.1.0.0/23" + cidr2 = fromJust $ cidr_from_string "10.1.0.0/24" 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 - cidr1 = cidr_from_string "10.1.0.0/24" - cidr2 = cidr_from_string "10.2.5.0/24" + TestCase $ + assertEqual + "10.1.0.0/24 is not adjacent to 10.2.5.0/24" + False + (cidr1 `adjacent` cidr2) + where + cidr1 = fromJust $ cidr_from_string "10.1.0.0/24" + cidr2 = fromJust $ cidr_from_string "10.2.5.0/24" 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" + TestCase $ + assertEqual + "10.1.1.0/24 is not adjacent to 10.1.2.0/24" + False + (cidr1 `adjacent` cidr2) + where + cidr1 = fromJust $ cidr_from_string "10.1.1.0/24" + cidr2 = fromJust $ cidr_from_string "10.1.2.0/24" 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_all 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] + 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 = fromJust $ cidr_from_string "10.0.0.0/8" + cidr2 = fromJust $ cidr_from_string "10.1.0.0/16" + cidr3 = fromJust $ 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 "192.168.1.0/24 combines with itself" [cidr1] (combine_all [cidr1, cidr1]) + TestCase $ + assertEqual + "192.168.3.0/23 does not contain 192.168.1.0/24" + [cidr1, cidr2] + (combine_contained [cidr1, cidr2]) + where + cidr1 = fromJust $ cidr_from_string "192.168.3.0/23" + cidr2 = fromJust $ 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 = fromJust $ cidr_from_string "10.0.0.0/24" + cidr2 = fromJust $ cidr_from_string "10.0.1.0/24" + cidr3 = fromJust $ cidr_from_string "10.0.2.0/24" + cidr4 = fromJust $ cidr_from_string "10.0.3.0/23" + cidr5 = fromJust $ cidr_from_string "10.0.0.0/23" + expected_cidrs = [fromJust $ cidr_from_string "10.0.0.0/22"] + test_cidrs = [cidr1, cidr2, cidr3, cidr4, cidr5] + + +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 "192.168.1.0/24" + cidr1 = fromJust $ cidr_from_string "127.0.0.1/32" + expected_cidrs = [cidr1] + test_cidrs = [cidr1, cidr1, cidr1, cidr1, cidr1] + + +test_combine_all3 :: Test +test_combine_all3 = + TestCase $ + assertEqual + "10.0.0.16, 10.0.0.17, 10.0.0.18, and 10.0.0.19 get combined into 10.0.0.16/30" + expected_cidrs + (combine_all test_cidrs) + where + cidr1 = fromJust $ cidr_from_string "10.0.0.16/32" + cidr2 = fromJust $ cidr_from_string "10.0.0.17/32" + cidr3 = fromJust $ cidr_from_string "10.0.0.18/32" + cidr4 = fromJust $ cidr_from_string "10.0.0.19/32" + expected_cidrs = [fromJust $ cidr_from_string "10.0.0.16/30"] + test_cidrs = [cidr1, cidr2, cidr3, cidr4] cidr_tests :: [Test] -cidr_tests = [ test_equality1, +cidr_tests = [ test_min_host1, + test_max_host1, + test_equality1, test_contains1, test_contains2, test_contains_proper1, @@ -288,7 +444,10 @@ cidr_tests = [ test_equality1, test_adjacent3, test_adjacent4, test_combine_contained1, - test_combine_contained2 + test_combine_contained2, + test_combine_all1, + test_combine_all2, + test_combine_all3 ] @@ -296,3 +455,10 @@ cidr_tests = [ test_equality1, 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))