+-- | The CIDR modules contains most of the functions used for working
+-- with the CIDR type.
module Cidr
( Cidr(..),
- cidr_from_string,
- combine_all
+ 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 IPv4Address
-import ListUtils
-import Maskable
-import Maskbits
-import Octet
+import Data.List (nub)
+import Data.List.Split (splitOneOf)
+import Data.Maybe (catMaybes, mapMaybe)
+import Test.Tasty ( TestTree, testGroup )
+import Test.Tasty.HUnit ( (@?=), testCase )
+import Test.Tasty.QuickCheck (
+ Arbitrary( arbitrary ),
+ Gen,
+ Property,
+ (==>),
+ testProperty )
+import Text.Read (readMaybe)
-data Cidr = None | Cidr { ipv4address :: IPv4Address,
- maskbits :: Maskbits }
- deriving (Eq, Show)
+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())
--- 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)
+data Cidr = Cidr { ipv4address :: IPv4Address,
+ maskbits :: Maskbits }
--- Takes an IP address String in CIDR notation, and returns a list of
--- its octets (as Ints).
+instance Show Cidr where
+ show cidr = (show (ipv4address cidr)) ++ "/" ++ (show (maskbits cidr))
+
+
+instance Arbitrary Cidr where
+ arbitrary = do
+ ipv4 <- arbitrary :: Gen IPv4Address
+ mask <- arbitrary :: Gen Maskbits
+ return (Cidr ipv4 mask)
+
+
+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 = addr1 == addr2 && mask1 == mask2
+ 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 =
- map octet_from_string (take 4 (splitWith (`elem` "./") 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, "")]
+ _ -> []
+ _ -> []
-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
+-- | 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
--- 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.
+-- | 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,
+-- 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 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
--- We want to get rid of all the Cidrs that are properly contained
--- in some other Cidr.
+-- | 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 =
- filter (not . (redundant cidrs)) cidrs
+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 ]
+
+
+-- 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))
projects / hath.git / blobdiff