module IPv4Address(
+ IPv4Address(..),
ipv4address_properties,
ipv4address_tests,
- IPv4Address(..),
- most_sig_bit_different,
-) where
-
-import Data.Maybe (fromJust)
-import Test.HUnit (assertEqual)
-import Test.Framework (Test, testGroup)
-import Test.Framework.Providers.HUnit (testCase)
-import Test.Framework.Providers.QuickCheck2 (testProperty)
-import Test.QuickCheck (Arbitrary(..), Gen, Property, (==>))
-
-import Maskable
-import Maskbits
-import Octet
+ most_sig_bit_different )
+where
+
+import Data.Int ( Int32, Int64 )
+import Data.Word ( Word32 )
+
+import Test.Tasty ( TestTree, testGroup )
+import Test.Tasty.HUnit ( (@?=), testCase )
+import Test.Tasty.QuickCheck (
+ Arbitrary( arbitrary ),
+ Gen,
+ Large,
+ Property,
+ Small,
+ (==>),
+ testProperty )
+
+import Maskable ( Maskable( apply_mask) )
+import Maskbits (
+ Maskbits(
+ Zero, One, Two, Three, Four, Five, Six, Seven, Eight,
+ Nine, Ten, Eleven, Twelve, Thirteen, Fourteen, Fifteen, Sixteen,
+ Seventeen, Eighteen, Nineteen, Twenty, TwentyOne, TwentyTwo, TwentyThree,
+ TwentyFour, TwentyFive, TwentySix, TwentySeven, TwentyEight, TwentyNine,
+ Thirty, ThirtyOne, ThirtyTwo ) )
+import Octet ( Octet( b1, b2, b3, b4, b5, b6, b7, b8) )
data IPv4Address =
IPv4Address { octet1 :: Octet,
octet2 :: Octet,
octet3 :: Octet,
octet4 :: Octet }
- deriving (Eq)
+ deriving (Eq, Ord)
instance Show IPv4Address where
--- | Convert @addr@ to an 'Int' by converting each octet to an 'Int'
--- and shifting the result to the left by 0,8.16, or 24 bits.
-ipv4address_to_int :: IPv4Address -> Int
-ipv4address_to_int addr =
- (shifted_oct1) + (shifted_oct2) + (shifted_oct3) + oct4
- where
- oct1 = octet_to_int (octet1 addr)
- oct2 = octet_to_int (octet2 addr)
- oct3 = octet_to_int (octet3 addr)
- oct4 = octet_to_int (octet4 addr)
-
- shifted_oct1 = oct1 * 2^(24 :: Integer)
- shifted_oct2 = oct2 * 2^(16 :: Integer)
- shifted_oct3 = oct3 * 2^(8 :: Integer)
-
-
-
--- | Convert an 'Int' @x@ to an 'IPv4Address'. Each octet of @x@ is
--- right-shifted by the appropriate number of bits, and the fractional
--- part is dropped.
-ipv4address_from_int :: Int -> Maybe IPv4Address
-ipv4address_from_int x
- | (x < 0) || (x > 2^(32 :: Integer) - 1) = Nothing
- | otherwise = do
- -- If the algebra is right, none of these octet_from_int calls
- -- below can fail since 0 <= x <= 2^32 - 1.
- oct1 <- octet_from_int shifted_x1
- oct2 <- octet_from_int shifted_x2
- oct3 <- octet_from_int shifted_x3
- oct4 <- octet_from_int x4
- return $ IPv4Address oct1 oct2 oct3 oct4
- where
- -- Chop off the higher octets. x1 = x `mod` 2^32, would be
- -- redundant.
- x2 = x `mod` 2^(24 :: Integer)
- x3 = x `mod` 2^(16 :: Integer)
- x4 = x `mod` 2^(8 :: Integer)
- -- Perform right-shifts. x4 doesn't need a shift.
- shifted_x1 = x `quot` 2^(24 :: Integer)
- shifted_x2 = x2 `quot` 2^(16 :: Integer)
- shifted_x3 = x3 `quot` 2^(8 :: Integer)
-
instance Enum IPv4Address where
- -- We're supposed to throw a runtime error if you call (succ
- -- maxBound), so the fromJust here doesn't introduce any additional
- -- badness.
- toEnum = fromJust . ipv4address_from_int
- fromEnum = ipv4address_to_int
+ -- | Convert an 'Int' @x@ to an 'IPv4Address'. Each octet of @x@ is
+ -- right-shifted by the appropriate number of bits, and the fractional
+ -- part is dropped.
+ toEnum signed_x =
+ IPv4Address oct1 oct2 oct3 oct4
+ where
+ -- Convert the input Int to a Word32 before we proceed. On x86,
+ -- the Int that we get could be negative (half of all IP
+ -- addresses correspond to negative numbers), and then the magic
+ -- below doesn't work. The Word32 type is unsigned, so we do the
+ -- math on that and then convert everything back to Int later on
+ -- once we have four much-smaller non-negative numbers.
+ x = fromIntegral signed_x :: Word32
+
+ -- Chop off the higher octets. x1 = x `mod` 2^32, would be
+ -- redundant.
+ x2 = x `mod` (2 ^ (24 :: Integer))
+ x3 = x `mod` (2 ^ (16 :: Integer))
+ x4 = (fromIntegral $ x `mod` (2 ^ (8 :: Integer))) :: Int
+ -- Perform right-shifts. x4 doesn't need a shift.
+ shifted_x1 = (fromIntegral $ x `quot` (2 ^ (24 :: Integer))) :: Int
+ shifted_x2 = (fromIntegral $ x2 `quot` (2 ^ (16 :: Integer))) :: Int
+ shifted_x3 = (fromIntegral $ x3 `quot` (2 ^ (8 :: Integer))) :: Int
+ oct1 = toEnum shifted_x1 :: Octet
+ oct2 = toEnum shifted_x2 :: Octet
+ oct3 = toEnum shifted_x3 :: Octet
+ oct4 = toEnum x4 :: Octet
+
+ -- | Convert @addr@ to an 'Int' by converting each octet to an 'Int'
+ -- and shifting the result to the left by 0,8.16, or 24 bits.
+ fromEnum addr =
+ (shifted_oct1) + (shifted_oct2) + (shifted_oct3) + oct4
+ where
+ oct1 = fromEnum (octet1 addr)
+ oct2 = fromEnum (octet2 addr)
+ oct3 = fromEnum (octet3 addr)
+ oct4 = fromEnum (octet4 addr)
+ shifted_oct1 = oct1 * (2 ^ (24 :: Integer))
+ shifted_oct2 = oct2 * (2 ^ (16 :: Integer))
+ shifted_oct3 = oct3 * (2 ^ (8 :: Integer))
-- | Given two addresses, find the number of the most significant bit
-- where they differ. If the addresses are the same, return
-- Test lists.
-ipv4address_tests :: Test
+ipv4address_tests :: TestTree
ipv4address_tests =
testGroup "IPv4 Address Tests" [
test_enum,
test_maxBound,
test_minBound,
test_most_sig_bit_different1,
- test_most_sig_bit_different2 ]
-
-ipv4address_properties :: Test
+ test_most_sig_bit_different2,
+ test_ord_instance1,
+ test_ord_instance2,
+ test_ord_instance3,
+ test_ord_instance4,
+ test_to_enum ]
+
+ipv4address_properties :: TestTree
ipv4address_properties =
testGroup
"IPv4 Address Properties "
- [ testProperty
- "fromEnum/toEnum are inverses"
- prop_from_enum_to_enum_inverses ]
+ [ prop_from_enum_to_enum_inverses_x32,
+ prop_from_enum_to_enum_inverses_x64 ]
-- QuickCheck properties
-prop_from_enum_to_enum_inverses :: Int -> Property
-prop_from_enum_to_enum_inverses x =
- (0 <= x) && (x <= 2^(32 :: Integer) - 1) ==>
- fromEnum (toEnum x :: IPv4Address) == x
+--
+-- We have two different tests to show that toEnum and fromEnum are
+-- inverses of one another. This part of the code isn't really
+-- type-safe, because the stupid Enum class insists that we use a
+-- machine 'Int' for our representation. Since IPv4 addresses can
+-- correspond to very large 32-bit integers, there's a possibility
+-- that our math is wrong in 32- but not 64-bits, and vice-versa.
+--
+-- tl;dr we want to ensure that this test passes when the 'Int' type
+-- is both 32-bit and 64-bit.
+
+-- Generate "Small" 64-bit numbers, because almost all 64-bit integers are
+-- too large to satisfy our predicate (i.e. also be 32-bit integers).
+prop_from_enum_to_enum_inverses_x64 :: TestTree
+prop_from_enum_to_enum_inverses_x64 =
+ testProperty "fromEnum and toEnum are inverses (x64)" prop
+ where
+ prop :: (Small Int64) -> Property
+ prop x =
+ 0 <= x && x <= (2 ^ (32 :: Integer)) - 1 ==>
+ fromIntegral (fromEnum (toEnum (fromIntegral x) :: IPv4Address)) == x
+
+-- According to the QuickCheck documentation, we need the "Large"
+-- modifier to ensure that the test cases are drawn from the entire
+-- range of Int32 values.
+prop_from_enum_to_enum_inverses_x32 :: TestTree
+prop_from_enum_to_enum_inverses_x32 =
+ testProperty "fromEnum and toEnum are inverses (x32)" prop
+ where
+ prop :: (Large Int32) -> Bool
+ prop x =
+ fromIntegral (fromEnum (toEnum (fromIntegral x) :: IPv4Address)) == x
-- HUnit Tests
mk_testaddr :: Int -> Int -> Int -> Int -> IPv4Address
mk_testaddr a b c d =
IPv4Address oct1 oct2 oct3 oct4
where
- oct1 = fromJust $ octet_from_int a
- oct2 = fromJust $ octet_from_int b
- oct3 = fromJust $ octet_from_int c
- oct4 = fromJust $ octet_from_int d
+ oct1 = toEnum a :: Octet
+ oct2 = toEnum b :: Octet
+ oct3 = toEnum c :: Octet
+ oct4 = toEnum d :: Octet
+
-test_minBound :: Test
+test_minBound :: TestTree
test_minBound =
- testCase desc $ assertEqual desc expected actual
+ testCase desc $ actual @?= expected
where
desc = "minBound should be 0.0.0.0"
expected = mk_testaddr 0 0 0 0
actual = minBound :: IPv4Address
-test_maxBound :: Test
+
+test_maxBound :: TestTree
test_maxBound =
- testCase desc $ assertEqual desc expected actual
+ testCase desc $ actual @?= expected
where
desc = "maxBound should be 255.255.255.255"
expected = mk_testaddr 255 255 255 255
actual = maxBound :: IPv4Address
-test_enum :: Test
+
+test_enum :: TestTree
test_enum =
- testCase desc $ assertEqual desc expected actual
+ testCase desc $ actual @?= expected
where
desc = "enumerating a /24 gives the correct addresses"
expected = ["192.168.0." ++ (show x) | x <- [0..255::Int] ]
ub = mk_testaddr 192 168 0 255
actual = map show [lb..ub]
-test_most_sig_bit_different1 :: Test
+
+test_most_sig_bit_different1 :: TestTree
test_most_sig_bit_different1 =
- testCase desc $ assertEqual desc
- TwentyFour
- bit
+ testCase desc $ actual @?= expected
where
desc = "10.1.1.0 and 10.1.0.0 differ in bit 24"
addr1 = mk_testaddr 10 1 1 0
addr2 = (mk_testaddr 10 1 0 0)
- bit = most_sig_bit_different addr1 addr2
+ expected = TwentyFour
+ actual = most_sig_bit_different addr1 addr2
-test_most_sig_bit_different2 :: Test
+test_most_sig_bit_different2 :: TestTree
test_most_sig_bit_different2 =
- testCase desc $ assertEqual desc
- TwentyThree
- bit
+ testCase desc $ actual @?= expected
where
desc = "10.1.2.0 and 10.1.1.0 differ in bit 23"
addr1 = mk_testaddr 10 1 2 0
addr2 = mk_testaddr 10 1 1 0
- bit = most_sig_bit_different addr1 addr2
+ expected = TwentyThree
+ actual = most_sig_bit_different addr1 addr2
+
+
+test_to_enum :: TestTree
+test_to_enum =
+ testCase desc $ actual @?= expected
+ where
+ desc = "192.168.0.0 in base-10 is 3232235520"
+ expected = mk_testaddr 192 168 0 0
+ -- We declare the big number as Word32 because otherwise, on x86,
+ -- we get a warning that it's too big to fit in a 32-bit integer.
+ -- Ultimately we convert it to a (negative) Int on those systems
+ -- anyway, but the gymnastics declare our intent to the compiler.
+ actual = toEnum (fromIntegral (3232235520 :: Word32)) :: IPv4Address
+
+
+test_ord_instance1 :: TestTree
+test_ord_instance1 =
+ testCase desc $ actual @?= expected
+ where
+ desc = "127.0.0.0 is less than 127.0.0.1"
+ addr1 = mk_testaddr 127 0 0 0
+ addr2 = mk_testaddr 127 0 0 1
+ expected = True
+ actual = addr1 <= addr2
+test_ord_instance2 :: TestTree
+test_ord_instance2 =
+ testCase desc $ actual @?= expected
+ where
+ desc = "127.0.0.0 is less than 127.0.1.0"
+ addr1 = mk_testaddr 127 0 0 0
+ addr2 = mk_testaddr 127 0 1 0
+ expected = True
+ actual = addr1 <= addr2
+
+test_ord_instance3 :: TestTree
+test_ord_instance3 =
+ testCase desc $ actual @?= expected
+ where
+ desc = "127.0.0.0 is less than 127.1.0.0"
+ addr1 = mk_testaddr 127 0 0 0
+ addr2 = mk_testaddr 127 1 0 0
+ expected = True
+ actual = addr1 <= addr2
+
+test_ord_instance4 :: TestTree
+test_ord_instance4 =
+ testCase desc $ actual @?= expected
+ where
+ desc = "127.0.0.0 is less than 128.0.0.0"
+ addr1 = mk_testaddr 127 0 0 0
+ addr2 = mk_testaddr 128 0 0 0
+ expected = True
+ actual = addr1 <= addr2
projects / hath.git / blobdiff