X-Git-Url: http://gitweb.michael.orlitzky.com/?a=blobdiff_plain;f=src%2FCidr.hs;h=af9c9e8ba55a6c9aaaa5190baf4800599a1623cc;hb=a8c2d85d8611f7f56eaa0c3406ec423d68f81f96;hp=4bb3d48ef788656c79abf8f971a46f07f1a3a48d;hpb=9b1ce7fe8f4dc65230b223f4156760e2b9c7f098;p=hath.git diff --git a/src/Cidr.hs b/src/Cidr.hs index 4bb3d48..af9c9e8 100644 --- a/src/Cidr.hs +++ b/src/Cidr.hs @@ -1,47 +1,595 @@ +-- | The CIDR modules contains most of the functions used for working +-- with the CIDR type. module Cidr ( Cidr(..), - cidr_from_string, - is_valid_cidr + cidr_properties, + cidr_tests, + combine_all, + contains, + contains_proper, + enumerate, + max_octet1, + max_octet2, + max_octet3, + max_octet4, + min_octet1, + min_octet2, + min_octet3, + min_octet4, + normalize ) where -import Text.Regex.Posix +import Data.List (nub) +import Data.List.Split (splitOneOf) +import Data.Maybe (catMaybes, mapMaybe) -import IPv4Address -import ListUtils -import Octet +import Test.Tasty ( TestTree, localOption, testGroup ) +import Test.Tasty.HUnit ( (@?=), testCase ) +import Test.Tasty.QuickCheck ( + Arbitrary( arbitrary ), + Gen, + Property, + QuickCheckTests( QuickCheckTests ), + (==>), + testProperty ) +import Text.Read (readMaybe) +import qualified Bit as B (Bit(..)) +import IPv4Address ( + IPv4Address( IPv4Address, octet1, octet2, octet3, octet4 ), + most_sig_bit_different ) +import Maskable (Maskable(apply_mask)) +import Maskbits ( Maskbits(Zero) ) +import Octet (Octet()) -data Cidr = None | Cidr { ipv4address :: IPv4Address, - maskbits :: Maskbits } - deriving (Eq, Show) --- 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}" +data Cidr = Cidr { ipv4address :: IPv4Address, + maskbits :: Maskbits } --- 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) +instance Show Cidr where + show cidr = (show (ipv4address cidr)) ++ "/" ++ (show (maskbits cidr)) --- Takes an IP address String in CIDR notation, and returns a list of --- its octets (as Ints). -octets_from_string :: String -> [Int] -octets_from_string s = map read (take 4 (splitWith (`elem` "./") s)) +instance Arbitrary Cidr where + arbitrary = do + ipv4 <- arbitrary :: Gen IPv4Address + mask <- arbitrary :: Gen Maskbits + return (Cidr ipv4 mask) -cidr_from_string :: String -> Cidr -cidr_from_string s - | addr == IPv4Address.None = Cidr.None - | otherwise = Cidr addr mbits - where - addr = ipv4address_from_octets (oct1) (oct2) (oct3) (oct4) - oct1 = octet_from_int (octs !! 0) - oct2 = octet_from_int (octs !! 1) - oct3 = octet_from_int (octs !! 2) - oct4 = octet_from_int (octs !! 3) - octs = octets_from_string s - mbits = maskbits_from_string s +instance Eq Cidr where + -- | Two CIDRs are equal if they have the same network bits and if + -- their masks are the same. In other words, if they are the same + -- after normalization. + cidr1 == cidr2 = (cidr1 <= cidr2) && (cidr2 <= cidr1) + +instance Ord Cidr where + cidr1 <= cidr2 = if addr1 == addr2 then mask1 <= mask2 else addr1 <= addr2 + where + Cidr addr1 mask1 = normalize cidr1 + Cidr addr2 mask2 = normalize cidr2 + +-- | 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 + + +-- | 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. +-- +-- 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 -> Cidr -> Bool +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 + + +-- | Contains but is not equal to. +contains_proper :: Cidr -> Cidr -> Bool +contains_proper 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. +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. +-- +-- 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 + | cidrs == (combine_contained unique_cidrs) = cidrs + | otherwise = combine_all (combine_contained unique_cidrs) + where + unique_cidrs = nub cidr_combinations + cidr_combinations = + 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. +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 -> Maybe Cidr +combine_adjacent cidr1 cidr2 + | 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. +adjacent :: Cidr -> Cidr -> Bool +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 + + +enumerate :: Cidr -> [IPv4Address] +enumerate cidr = [(min_host cidr)..(max_host cidr)] + + +-- | Replace any masked bits in this CIDR's IPv4Address with zeros. +normalize :: Cidr -> Cidr +normalize (Cidr addr mask) = + Cidr nrml_addr mask + where + nrml_addr = apply_mask addr mask B.Zero + +-- 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, + test_normalize1, + test_normalize2, + test_normalize3 ] + +cidr_properties :: TestTree +cidr_properties = + testGroup "CIDR Properties" [ + prop_all_cidrs_contain_themselves, + prop_contains_proper_antisymmetric, + prop_normalize_idempotent, + prop_normalize_preserves_equality, + prop_ord_instance_antisymmetric, + prop_ord_instance_reflexive, + prop_ord_instance_transitive ] + + +-- HUnit Tests +test_enumerate :: TestTree +test_enumerate = + testCase desc $ actual @?= expected + where + desc = "192.168.0.240/30 is enumerated correctly" + oct1 = toEnum 192 :: Octet + oct2 = toEnum 168 :: Octet + oct3 = minBound :: Octet + 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" :: Cidr) + +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" :: Cidr) + expected = "10.0.0.0" + + +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" :: Cidr) + expected = "10.0.0.255" + + +test_equality1 :: TestTree +test_equality1 = + 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 :: TestTree +test_contains1 = + testCase desc $ actual @?= expected + where + desc = "10.1.1.0/23 contains 10.1.1.0/24" + cidr1 = read "10.1.1.0/23" :: Cidr + cidr2 = read "10.1.1.0/24" :: Cidr + expected = True + actual = cidr1 `contains` cidr2 + + +test_contains2 :: TestTree +test_contains2 = + testCase desc $ actual @?= expected + where + desc = "10.1.1.0/23 contains itself" + cidr1 = read "10.1.1.0/23" :: Cidr + expected = True + actual = cidr1 `contains` cidr1 + + +test_contains_proper1 :: TestTree +test_contains_proper1 = + 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" :: Cidr + cidr2 = read "10.1.1.0/24" :: Cidr + expected = True + actual = cidr1 `contains_proper` cidr2 + + +test_contains_proper2 :: TestTree +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" :: Cidr + 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" :: Cidr + cidr2 = read "10.1.1.0/24" :: Cidr + 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" :: Cidr + cidr2 = read "10.1.0.0/24" :: Cidr + 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" :: Cidr + cidr2 = read "10.2.5.0/24" :: Cidr + 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" :: Cidr + cidr2 = read "10.1.2.0/24" :: Cidr + 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" :: Cidr + cidr2 = read "10.1.0.0/16" :: Cidr + cidr3 = read "10.1.1.0/24" :: Cidr + 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" :: Cidr + cidr2 = read "192.168.1.0/24" :: Cidr + 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" :: Cidr + cidr2 = read "10.0.1.0/24" :: Cidr + cidr3 = read "10.0.2.0/24" :: Cidr + cidr4 = read "10.0.3.0/23" :: Cidr + cidr5 = read "10.0.0.0/23" :: Cidr + test_cidrs = [cidr1, cidr2, cidr3, cidr4, cidr5] + expected = [read "10.0.0.0/22" :: Cidr] + 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" :: Cidr + 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" :: Cidr + cidr2 = read "10.0.0.17/32" :: Cidr + cidr3 = read "10.0.0.18/32" :: Cidr + cidr4 = read "10.0.0.19/32" :: Cidr + test_cidrs = [cidr1, cidr2, cidr3, cidr4] + expected = [read "10.0.0.16/30" :: Cidr] + actual = combine_all test_cidrs + +test_normalize1 :: TestTree +test_normalize1 = + testCase desc $ actual @?= expected + where + desc = "127.0.0.1/8 normalized is 127.0.0.0/8" + expected = read "127.0.0.0/8" :: Cidr + actual = normalize (read "127.0.0.1/8" :: Cidr) + + +test_normalize2 :: TestTree +test_normalize2 = + testCase desc $ actual @?= expected + where + desc = "192.168.1.101/24 normalized is 192.168.1.0/24" + expected = read "192.168.1.0/24" :: Cidr + actual = normalize (read "192.168.1.101/24" :: Cidr) + +test_normalize3 :: TestTree +test_normalize3 = + testCase desc $ actual @?= expected + where + desc = "10.10.10.10/22 normalized is 10.10.8.0/22" + expected = read "10.10.8.0/22" :: Cidr + actual = normalize (read "10.10.10.10/22" :: Cidr) + +-- 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)) + + +-- Running "normalize" a second time shouldn't do anything. +prop_normalize_idempotent :: TestTree +prop_normalize_idempotent = + testProperty "The CIDR \"normalize\" function is idempotent" prop + where + prop :: Cidr -> Bool + prop cidr = (normalize cidr) == (normalize (normalize cidr)) + +-- Normalization should not affect equality of two CIDRs. +prop_normalize_preserves_equality :: TestTree +prop_normalize_preserves_equality = + testProperty "The CIDR \"normalize\" function preserves equality" prop + where + prop :: Cidr -> Cidr -> Bool + prop cidr1 cidr2 = (cidr1 == cidr2) == (normalize cidr1 == normalize cidr2) + + +prop_ord_instance_reflexive :: TestTree +prop_ord_instance_reflexive = + testProperty "The CIDR order is reflexive" prop + where + prop :: Cidr -> Bool + prop cidr = cidr <= cidr + + +prop_ord_instance_transitive :: TestTree +prop_ord_instance_transitive = + testProperty "The CIDR order is transitive" prop + where + prop :: Cidr -> Cidr -> Cidr -> Property + prop cidr1 cidr2 cidr3 = + (cidr1 <= cidr2 && cidr2 <= cidr3) ==> cidr1 <= cidr3 + +-- This is how Eq is currently implemented, but it is useful to have +-- around in case that changes. Try fewer instances of this than usual +-- because it's a rare condition. +prop_ord_instance_antisymmetric :: TestTree +prop_ord_instance_antisymmetric = + localOption (QuickCheckTests 500) $ + testProperty "The CIDR order is antisymmetric" prop + where + prop :: Cidr -> Cidr -> Property + prop cidr1 cidr2 = + (cidr1 <= cidr2 && cidr2 <= cidr1) ==> cidr1 == cidr2