X-Git-Url: http://gitweb.michael.orlitzky.com/?a=blobdiff_plain;f=src%2FCidr.hs;h=6e759660486a1dffc5e1967c147ac7ff1b4d464d;hb=eee156f562f9c1c1194a67cef12f146304d88ce9;hp=ff357bee673eac676fffd540844dc3c3eac7c3b9;hpb=103f95bf9bf2ad9908ec7a82691b81b1182774c7;p=hath.git diff --git a/src/Cidr.hs b/src/Cidr.hs index ff357be..6e75966 100644 --- a/src/Cidr.hs +++ b/src/Cidr.hs @@ -1,168 +1,250 @@ +-- | The CIDR modules contains most of the functions used for working +-- with the CIDR type. module Cidr ( Cidr(..), - cidr_from_string, + cidr_properties, cidr_tests, - combine_all + combine_all, + contains, + contains_proper, + enumerate, + max_octet1, + max_octet2, + max_octet3, + max_octet4, + min_octet1, + min_octet2, + min_octet3, + min_octet4, ) where import Data.List (nubBy) -import Test.HUnit +import Data.List.Split (splitOneOf) +import Data.Maybe (catMaybes, mapMaybe) -import IPv4Address -import ListUtils -import Maskable -import Maskbits -import Octet +import Test.QuickCheck ( Gen ) -- Not re-exported by tasty +import Test.Tasty ( TestTree, testGroup ) +import Test.Tasty.HUnit ( (@?=), testCase ) +import Test.Tasty.QuickCheck ( + Arbitrary(..), + Property, + (==>), + testProperty ) +import Text.Read (readMaybe) +import qualified Bit as B (Bit(..)) +import IPv4Address (IPv4Address(..), most_sig_bit_different) +import Maskable (Maskable(..)) +import Maskbits (Maskbits(..)) +import Octet (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)) --- 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)) - --- 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) - +instance Arbitrary Cidr where + arbitrary = do + ipv4 <- arbitrary :: Gen IPv4Address + mask <- arbitrary :: Gen Maskbits + return (Cidr ipv4 mask) --- 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)) +instance Eq Cidr where + cidr1 == cidr2 = (cidr1 `equivalent` cidr2) -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 +-- | Two CIDR ranges are equivalent if they have the same network bits +-- and the masks are the same. +equivalent :: Cidr -> Cidr -> Bool +equivalent (Cidr addr1 mbits1) (Cidr 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 -> Maybe Maskbits +maskbits_from_cidr_string s + | length partlist == 2 = readMaybe (partlist !! 1) + | otherwise = Nothing + where + partlist = splitOneOf "/" s --- 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. +-- | 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 = + case parts of + (p1:p2:p3:p4:_) -> mapMaybe readMaybe [p1,p2,p3,p4] + _ -> [] + where + parts = splitOneOf "./" s + +instance Read Cidr where + -- | Parse everything or nothing. + readsPrec _ s = + case (octets_from_cidr_string s) of + [oct1, oct2, oct3, oct4] -> + case (maskbits_from_cidr_string s) of + Just mbits -> + [(Cidr (IPv4Address oct1 oct2 oct3 oct4) mbits, "")] + _ -> [] + _ -> [] + + +-- | Given a CIDR, return the minimum valid IPv4 address contained +-- within it. +min_host :: Cidr -> IPv4Address +min_host (Cidr addr mask) = apply_mask addr mask B.Zero + +-- | Given a CIDR, return the maximum valid IPv4 address contained +-- within it. +max_host :: Cidr -> IPv4Address +max_host (Cidr addr mask) = apply_mask addr mask B.One + +-- | Given a CIDR, return the first octet of the minimum valid IPv4 +-- address contained within it. +min_octet1 :: Cidr -> Octet +min_octet1 cidr = octet1 (min_host cidr) + +-- | Given a CIDR, return the second octet of the minimum valid IPv4 +-- address contained within it. +min_octet2 :: Cidr -> Octet +min_octet2 cidr = octet2 (min_host cidr) + +-- | Given a CIDR, return the third octet of the minimum valid IPv4 +-- address contained within it. +min_octet3 :: Cidr -> Octet +min_octet3 cidr = octet3 (min_host cidr) + +-- | Given a CIDR, return the fourth octet of the minimum valid IPv4 +-- address contained within it. +min_octet4 :: Cidr -> Octet +min_octet4 cidr = octet4 (min_host cidr) + +-- | Given a CIDR, return the first octet of the maximum valid IPv4 +-- address contained within it. +max_octet1 :: Cidr -> Octet +max_octet1 cidr = octet1 (max_host cidr) + +-- | Given a CIDR, return the second octet of the maximum valid IPv4 +-- address contained within it. +max_octet2 :: Cidr -> Octet +max_octet2 cidr = octet2 (max_host cidr) + +-- | Given a CIDR, return the third octet of the maximum valid IPv4 +-- address contained within it. +max_octet3 :: Cidr -> Octet +max_octet3 cidr = octet3 (max_host cidr) + +-- | Given a CIDR, return the fourth octet of the maximum valid IPv4 +-- address contained within it. +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. -- --- 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, +-- 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. -- --- cidr1 = 192.168.1.0/23, cidr2 = 192.168.1.100/24 +-- 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, -- --- 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.. +-- cidr1 = 192.168.1.0\/23, cidr2 = 192.168.1.100\/24 -- --- 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. +-- 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 -> 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 but is not equal to. 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 = pred (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. @@ -174,52 +256,247 @@ adjacent cidr1 cidr2 mbits2 = maskbits cidr2 - +enumerate :: Cidr -> [IPv4Address] +enumerate cidr = [(min_host cidr)..(max_host cidr)] + +-- Test lists. +cidr_tests :: TestTree +cidr_tests = + testGroup "CIDR Tests" [ + test_enumerate, + test_min_host1, + test_max_host1, + 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, + test_combine_all3 ] + +cidr_properties :: TestTree +cidr_properties = + testGroup "CIDR Properties" [ + prop_all_cidrs_contain_themselves, + prop_contains_proper_antisymmetric ] -- HUnit Tests +test_enumerate :: TestTree +test_enumerate = + testCase desc $ actual @?= expected + where + desc = "192.168.0.240/30 is enumerated correctly" + oct1 = toEnum 192 + oct2 = toEnum 168 + oct3 = minBound + mk_ip = IPv4Address oct1 oct2 oct3 + addr1 = mk_ip $ toEnum 240 + addr2 = mk_ip $ toEnum 241 + addr3 = mk_ip $ toEnum 242 + addr4 = mk_ip $ toEnum 243 + expected = [addr1, addr2, addr3, addr4] + actual = enumerate $ read "192.168.0.240/30" + +test_min_host1 :: TestTree +test_min_host1 = + testCase desc $ actual @?= expected + where + desc = "The minimum host in 10.0.0.0/24 is 10.0.0.0" + actual = show $ min_host (read "10.0.0.0/24") + expected = "10.0.0.0" -test_equality1 :: Test + +test_max_host1 :: TestTree +test_max_host1 = + testCase desc $ actual @?= expected + where + desc = "The maximum host in 10.0.0.0/24 is 10.0.0.255" + actual = show $ max_host (read "10.0.0.0/24") + expected = "10.0.0.255" + + +test_equality1 :: TestTree 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 desc $ actual @?= expected + where + desc = "10.1.1.0/23 equals itself" + actual = read "10.1.1.0/23" :: Cidr + expected = read "10.1.1.0/23" :: Cidr -test_contains1 :: Test +test_contains1 :: TestTree 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 desc $ actual @?= expected + where + desc = "10.1.1.0/23 contains 10.1.1.0/24" + cidr1 = read "10.1.1.0/23" + cidr2 = read "10.1.1.0/24" + expected = True + actual = cidr1 `contains` cidr2 + - -test_contains2 :: Test +test_contains2 :: TestTree 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 desc $ actual @?= expected + where + desc = "10.1.1.0/23 contains itself" + cidr1 = read "10.1.1.0/23" + expected = True + actual = cidr1 `contains` cidr1 -test_contains_proper1 :: Test +test_contains_proper1 :: TestTree 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 desc $ actual @?= expected + where + desc = "10.1.1.0/23 contains 10.1.1.0/24 properly" + cidr1 = read "10.1.1.0/23" + cidr2 = read "10.1.1.0/24" + expected = True + actual = cidr1 `contains_proper` cidr2 -test_contains_proper2 :: Test +test_contains_proper2 :: TestTree 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" - - -cidr_tests :: [Test] -cidr_tests = [ test_equality1, - test_contains1, - test_contains2, - test_contains_proper1, - test_contains_proper2 - ] + testCase desc $ actual @?= expected + where + desc = "10.1.1.0/23 does not contain itself properly" + cidr1 = read "10.1.1.0/23" + expected = False + actual = cidr1 `contains_proper` cidr1 + + +test_adjacent1 :: TestTree +test_adjacent1 = + testCase desc $ actual @?= expected + where + desc = "10.1.0.0/24 is adjacent to 10.1.1.0/24" + cidr1 = read "10.1.0.0/24" + cidr2 = read "10.1.1.0/24" + expected = True + actual = cidr1 `adjacent` cidr2 + + +test_adjacent2 :: TestTree +test_adjacent2 = + testCase desc $ actual @?= expected + where + desc = "10.1.0.0/23 is not adjacent to 10.1.0.0/24" + cidr1 = read "10.1.0.0/23" + cidr2 = read "10.1.0.0/24" + expected = False + actual = cidr1 `adjacent` cidr2 + + +test_adjacent3 :: TestTree +test_adjacent3 = + testCase desc $ actual @?= expected + where + desc = "10.1.0.0/24 is not adjacent to 10.2.5.0/24" + cidr1 = read "10.1.0.0/24" + cidr2 = read "10.2.5.0/24" + expected = False + actual = cidr1 `adjacent` cidr2 + + +test_adjacent4 :: TestTree +test_adjacent4 = + testCase desc $ actual @?= expected + where + desc = "10.1.1.0/24 is not adjacent to 10.1.2.0/24" + cidr1 = read "10.1.1.0/24" + cidr2 = read "10.1.2.0/24" + expected = False + actual = cidr1 `adjacent` cidr2 + +test_combine_contained1 :: TestTree +test_combine_contained1 = + testCase desc $ actual @?= expected + where + desc = "10.0.0.0/8, 10.1.0.0/16, and 10.1.1.0/24 combine to 10.0.0.0/8" + cidr1 = read "10.0.0.0/8" + cidr2 = read "10.1.0.0/16" + cidr3 = read "10.1.1.0/24" + test_cidrs = [cidr1, cidr2, cidr3] + expected = [cidr1] + actual = combine_contained test_cidrs + +test_combine_contained2 :: TestTree +test_combine_contained2 = + testCase desc $ actual @?= expected + where + desc = "192.168.3.0/23 does not contain 192.168.1.0/24" + cidr1 = read "192.168.3.0/23" + cidr2 = read "192.168.1.0/24" + expected = [cidr1, cidr2] + actual = combine_contained [cidr1, cidr2] + + +test_combine_all1 :: TestTree +test_combine_all1 = + testCase desc $ actual @?= expected + where + desc = "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" + cidr1 = read "10.0.0.0/24" + cidr2 = read "10.0.1.0/24" + cidr3 = read "10.0.2.0/24" + cidr4 = read "10.0.3.0/23" + cidr5 = read "10.0.0.0/23" + test_cidrs = [cidr1, cidr2, cidr3, cidr4, cidr5] + expected = [read "10.0.0.0/22"] + actual = combine_all test_cidrs + + +test_combine_all2 :: TestTree +test_combine_all2 = + testCase desc $ actual @?= expected + where + desc = "127.0.0.1/32 combines with itself recursively" + cidr1 = read "127.0.0.1/32" + test_cidrs = [cidr1, cidr1, cidr1, cidr1, cidr1] + expected = [cidr1] + actual = combine_all test_cidrs + + +test_combine_all3 :: TestTree +test_combine_all3 = + testCase desc $ actual @?= expected + where + desc = "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" + cidr1 = read "10.0.0.16/32" + cidr2 = read "10.0.0.17/32" + cidr3 = read "10.0.0.18/32" + cidr4 = read "10.0.0.19/32" + test_cidrs = [cidr1, cidr2, cidr3, cidr4] + expected = [read "10.0.0.16/30"] + actual = combine_all test_cidrs + +-- QuickCheck Tests +prop_all_cidrs_contain_themselves :: TestTree +prop_all_cidrs_contain_themselves = + testProperty "All CIDRs contain themselves" prop + where + prop :: Cidr -> Bool + prop cidr1 = cidr1 `contains` cidr1 + + +-- If cidr1 properly contains cidr2, then by definition cidr2 +-- does not properly contain cidr1. +prop_contains_proper_antisymmetric :: TestTree +prop_contains_proper_antisymmetric = + testProperty "CIDR proper containment is an antisymmetric relation" prop + where + prop :: Cidr -> Cidr -> Property + prop cidr1 cidr2 = + (cidr1 `contains_proper` cidr2) ==> + (not (cidr2 `contains_proper` cidr1))