src/IPv4Address.hs

   1 module IPv4Address(
   2   IPv4Address(..),
   3   ipv4address_properties,
   4   ipv4address_tests,
   5   most_sig_bit_different )
   6 where
   7
   8
   9 import Test.QuickCheck ( Gen ) -- Not re-exported by tasty
  10 import Test.Tasty ( TestTree, testGroup )
  11 import Test.Tasty.HUnit ( (@?=), testCase )
  12 import Test.Tasty.QuickCheck (
  13   Arbitrary(..),
  14   Property,
  15   (==>),
  16   testProperty )
  17
  18 import Maskable (Maskable(..))
  19 import Maskbits (Maskbits(..))
  20 import Octet (Octet(..))
  21
  22 data IPv4Address =
  23   IPv4Address { octet1 :: Octet,
  24                 octet2 :: Octet,
  25                 octet3 :: Octet,
  26                 octet4 :: Octet }
  27     deriving (Eq)
  28
  29
  30 instance Show IPv4Address where
  31   show addr = concat [(show oct1) ++ ".",
  32                       (show oct2) ++ ".",
  33                       (show oct3) ++ ".",
  34                       (show oct4)]
  35       where
  36         oct1 = (octet1 addr)
  37         oct2 = (octet2 addr)
  38         oct3 = (octet3 addr)
  39         oct4 = (octet4 addr)
  40
  41
  42 instance Arbitrary IPv4Address where
  43   arbitrary = do
  44     oct1 <- arbitrary :: Gen Octet
  45     oct2 <- arbitrary :: Gen Octet
  46     oct3 <- arbitrary :: Gen Octet
  47     oct4 <- arbitrary :: Gen Octet
  48     return (IPv4Address oct1 oct2 oct3 oct4)
  49
  50
  51
  52 instance Maskable IPv4Address where
  53
  54   apply_mask addr mask bit =
  55    apply_mask' mask
  56    where
  57      oct1 = octet1 addr
  58      oct2 = octet2 addr
  59      oct3 = octet3 addr
  60      oct4 = octet4 addr
  61
  62      -- A copy of 'addr' with the fourth octet zeroed (or oned).
  63      new_addr1 = addr { octet4 = (apply_mask oct4 Zero bit) }
  64
  65      -- Likewise for new_addr1's third octet.
  66      new_addr2 = new_addr1 { octet3 = (apply_mask oct3 Zero bit) }
  67
  68      -- And new_addr2's second octet.
  69      new_addr3 = new_addr2 { octet2 = (apply_mask oct2 Zero bit) }
  70
  71      -- This helper function allows us to pattern-match cleanly.
  72      apply_mask' :: Maskbits -> IPv4Address
  73
  74      apply_mask' ThirtyTwo = addr
  75
  76      apply_mask' ThirtyOne = addr { octet4 = (apply_mask oct4 Seven bit) }
  77
  78      apply_mask' Thirty =
  79        addr { octet4 = (apply_mask oct4 Six bit) }
  80
  81      apply_mask' TwentyNine =
  82        addr { octet4 = (apply_mask oct4 Five bit) }
  83
  84      apply_mask' TwentyEight =
  85        addr { octet4 = (apply_mask oct4 Four bit) }
  86
  87      apply_mask' TwentySeven =
  88        addr { octet4 = (apply_mask oct4 Three bit) }
  89
  90      apply_mask' TwentySix =
  91        addr { octet4 = (apply_mask oct4 Two bit) }
  92
  93      apply_mask' TwentyFive =
  94        addr { octet4 = (apply_mask oct4 One bit) }
  95
  96      apply_mask' TwentyFour = new_addr1
  97
  98      apply_mask' TwentyThree =
  99        new_addr1 { octet3 = (apply_mask oct3 Seven bit) }
 100
 101      apply_mask' TwentyTwo =
 102        new_addr1 { octet3 = (apply_mask oct3 Six bit) }
 103
 104      apply_mask' TwentyOne =
 105        new_addr1 { octet3 = (apply_mask oct3 Five bit) }
 106
 107      apply_mask' Twenty =
 108        new_addr1 { octet3 = (apply_mask oct3 Four bit) }
 109
 110      apply_mask' Nineteen =
 111        new_addr1 { octet3 = (apply_mask oct3 Three bit) }
 112
 113      apply_mask' Eighteen =
 114        new_addr1 { octet3 = (apply_mask oct3 Two bit) }
 115
 116      apply_mask' Seventeen =
 117        new_addr1 { octet3 = (apply_mask oct3 One bit) }
 118
 119      apply_mask' Sixteen =
 120        new_addr2
 121
 122      apply_mask' Fifteen =
 123        new_addr2 { octet2 = (apply_mask oct2 Seven bit) }
 124
 125      apply_mask' Fourteen =
 126        new_addr2 { octet2 = (apply_mask oct2 Six bit) }
 127
 128      apply_mask' Thirteen =
 129        new_addr2 { octet2 = (apply_mask oct2 Five bit) }
 130
 131      apply_mask' Twelve =
 132        new_addr2 { octet2 = (apply_mask oct2 Four bit) }
 133
 134      apply_mask' Eleven =
 135        new_addr2 { octet2 = (apply_mask oct2 Three bit) }
 136
 137      apply_mask' Ten =
 138        new_addr2 { octet2 = (apply_mask oct2 Two bit) }
 139
 140      apply_mask' Nine =
 141        new_addr2 { octet2 = (apply_mask oct2 One bit) }
 142
 143      apply_mask' Eight =
 144        new_addr3 { octet2 = (apply_mask oct2 Zero bit) }
 145
 146      apply_mask' Seven =
 147        new_addr3 { octet1 = (apply_mask oct1 Seven bit) }
 148
 149      apply_mask' Six =
 150        new_addr3 { octet1 = (apply_mask oct1 Six bit) }
 151
 152      apply_mask' Five =
 153        new_addr3 { octet1 = (apply_mask oct1 Five bit) }
 154
 155      apply_mask' Four =
 156        new_addr3 { octet1 = (apply_mask oct1 Four bit) }
 157
 158      apply_mask' Three =
 159        new_addr3 { octet1 = (apply_mask oct1 Three bit) }
 160
 161      apply_mask' Two =
 162        new_addr3 { octet1 = (apply_mask oct1 Two bit) }
 163
 164      apply_mask' One =
 165        new_addr3 { octet1 = (apply_mask oct1 One bit) }
 166
 167      apply_mask' Zero =
 168        new_addr3 { octet1 = (apply_mask oct1 Zero bit) }
 169
 170
 171 instance Bounded IPv4Address where
 172   -- | The minimum possible IPv4 address, 0.0.0.0.
 173   minBound = IPv4Address minBound minBound minBound minBound
 174
 175   -- | The maximum possible IPv4 address, 255.255.255.255.
 176   maxBound = IPv4Address maxBound maxBound maxBound maxBound
 177
 178
 179
 180
 181 instance Enum IPv4Address where
 182   -- | Convert an 'Int' @x@ to an 'IPv4Address'. Each octet of @x@ is
 183   --   right-shifted by the appropriate number of bits, and the fractional
 184   --   part is dropped.
 185   toEnum x =
 186     IPv4Address oct1 oct2 oct3 oct4
 187     where
 188       -- Chop off the higher octets. x1 = x `mod` 2^32, would be
 189       -- redundant.
 190       x2 = x `mod` 2^(24 :: Integer)
 191       x3 = x `mod` 2^(16 :: Integer)
 192       x4 = x `mod` 2^(8  :: Integer)
 193       -- Perform right-shifts. x4 doesn't need a shift.
 194       shifted_x1 = x `quot` 2^(24 :: Integer)
 195       shifted_x2 = x2 `quot` 2^(16 :: Integer)
 196       shifted_x3 = x3 `quot` 2^(8 :: Integer)
 197       oct1 = toEnum shifted_x1
 198       oct2 = toEnum shifted_x2
 199       oct3 = toEnum shifted_x3
 200       oct4 = toEnum x4
 201
 202   -- | Convert @addr@ to an 'Int' by converting each octet to an 'Int'
 203   --   and shifting the result to the left by 0,8.16, or 24 bits.
 204   fromEnum addr =
 205     (shifted_oct1) + (shifted_oct2) + (shifted_oct3) + oct4
 206     where
 207       oct1 = fromEnum (octet1 addr)
 208       oct2 = fromEnum (octet2 addr)
 209       oct3 = fromEnum (octet3 addr)
 210       oct4 = fromEnum (octet4 addr)
 211       shifted_oct1 = oct1 * 2^(24 :: Integer)
 212       shifted_oct2 = oct2 * 2^(16 :: Integer)
 213       shifted_oct3 = oct3 * 2^(8 :: Integer)
 214
 215 -- | Given two addresses, find the number of the most significant bit
 216 --   where they differ. If the addresses are the same, return
 217 --   Maskbits.Zero.
 218 most_sig_bit_different :: IPv4Address -> IPv4Address -> Maskbits
 219 most_sig_bit_different addr1 addr2
 220   | addr1 == addr2 = Maskbits.Zero
 221   | m1  /= n1  = Maskbits.One
 222   | m2  /= n2  = Two
 223   | m3  /= n3  = Three
 224   | m4  /= n4  = Four
 225   | m5  /= n5  = Five
 226   | m6  /= n6  = Six
 227   | m7  /= n7  = Seven
 228   | m8  /= n8  = Eight
 229   | m9  /= n9  = Nine
 230   | m10 /= n10 = Ten
 231   | m11 /= n11 = Eleven
 232   | m12 /= n12 = Twelve
 233   | m13 /= n13 = Thirteen
 234   | m14 /= n14 = Fourteen
 235   | m15 /= n15 = Fifteen
 236   | m16 /= n16 = Sixteen
 237   | m17 /= n17 = Seventeen
 238   | m18 /= n18 = Eighteen
 239   | m19 /= n19 = Nineteen
 240   | m20 /= n20 = Twenty
 241   | m21 /= n21 = TwentyOne
 242   | m22 /= n22 = TwentyTwo
 243   | m23 /= n23 = TwentyThree
 244   | m24 /= n24 = TwentyFour
 245   | m25 /= n25 = TwentyFive
 246   | m26 /= n26 = TwentySix
 247   | m27 /= n27 = TwentySeven
 248   | m28 /= n28 = TwentyEight
 249   | m29 /= n29 = TwentyNine
 250   | m30 /= n30 = Thirty
 251   | m31 /= n31 = ThirtyOne
 252   | m32 /= n32 = ThirtyTwo
 253   | otherwise  = Maskbits.Zero
 254   where
 255     m1  = (b1 oct1a)
 256     m2  = (b2 oct1a)
 257     m3  = (b3 oct1a)
 258     m4  = (b4 oct1a)
 259     m5  = (b5 oct1a)
 260     m6  = (b6 oct1a)
 261     m7  = (b7 oct1a)
 262     m8  = (b8 oct1a)
 263     m9  = (b1 oct2a)
 264     m10 = (b2 oct2a)
 265     m11 = (b3 oct2a)
 266     m12 = (b4 oct2a)
 267     m13 = (b5 oct2a)
 268     m14 = (b6 oct2a)
 269     m15 = (b7 oct2a)
 270     m16 = (b8 oct2a)
 271     m17 = (b1 oct3a)
 272     m18 = (b2 oct3a)
 273     m19 = (b3 oct3a)
 274     m20 = (b4 oct3a)
 275     m21 = (b5 oct3a)
 276     m22 = (b6 oct3a)
 277     m23 = (b7 oct3a)
 278     m24 = (b8 oct3a)
 279     m25 = (b1 oct4a)
 280     m26 = (b2 oct4a)
 281     m27 = (b3 oct4a)
 282     m28 = (b4 oct4a)
 283     m29 = (b5 oct4a)
 284     m30 = (b6 oct4a)
 285     m31 = (b7 oct4a)
 286     m32 = (b8 oct4a)
 287     oct1a = (octet1 addr1)
 288     oct2a = (octet2 addr1)
 289     oct3a = (octet3 addr1)
 290     oct4a = (octet4 addr1)
 291     n1  = (b1 oct1b)
 292     n2  = (b2 oct1b)
 293     n3  = (b3 oct1b)
 294     n4  = (b4 oct1b)
 295     n5  = (b5 oct1b)
 296     n6  = (b6 oct1b)
 297     n7  = (b7 oct1b)
 298     n8  = (b8 oct1b)
 299     n9  = (b1 oct2b)
 300     n10 = (b2 oct2b)
 301     n11 = (b3 oct2b)
 302     n12 = (b4 oct2b)
 303     n13 = (b5 oct2b)
 304     n14 = (b6 oct2b)
 305     n15 = (b7 oct2b)
 306     n16 = (b8 oct2b)
 307     n17 = (b1 oct3b)
 308     n18 = (b2 oct3b)
 309     n19 = (b3 oct3b)
 310     n20 = (b4 oct3b)
 311     n21 = (b5 oct3b)
 312     n22 = (b6 oct3b)
 313     n23 = (b7 oct3b)
 314     n24 = (b8 oct3b)
 315     n25 = (b1 oct4b)
 316     n26 = (b2 oct4b)
 317     n27 = (b3 oct4b)
 318     n28 = (b4 oct4b)
 319     n29 = (b5 oct4b)
 320     n30 = (b6 oct4b)
 321     n31 = (b7 oct4b)
 322     n32 = (b8 oct4b)
 323     oct1b = (octet1 addr2)
 324     oct2b = (octet2 addr2)
 325     oct3b = (octet3 addr2)
 326     oct4b = (octet4 addr2)
 327
 328
 329 -- Test lists.
 330 ipv4address_tests :: TestTree
 331 ipv4address_tests =
 332   testGroup "IPv4 Address Tests" [
 333     test_enum,
 334     test_maxBound,
 335     test_minBound,
 336     test_most_sig_bit_different1,
 337     test_most_sig_bit_different2,
 338     test_to_enum ]
 339
 340 ipv4address_properties :: TestTree
 341 ipv4address_properties =
 342   testGroup
 343     "IPv4 Address Properties "
 344     [ prop_from_enum_to_enum_inverses ]
 345
 346 -- QuickCheck properties
 347 prop_from_enum_to_enum_inverses :: TestTree
 348 prop_from_enum_to_enum_inverses =
 349   testProperty "fromEnum and toEnum are inverses" prop
 350   where
 351     prop :: Int -> Property
 352     prop x =
 353       (0 <= x) && (x <= 2^(32 :: Integer) - 1) ==>
 354         fromEnum (toEnum x :: IPv4Address) == x
 355
 356 -- HUnit Tests
 357 mk_testaddr :: Int -> Int -> Int -> Int -> IPv4Address
 358 mk_testaddr a b c d =
 359   IPv4Address oct1 oct2 oct3 oct4
 360   where
 361     oct1 = toEnum a
 362     oct2 = toEnum b
 363     oct3 = toEnum c
 364     oct4 = toEnum d
 365
 366
 367 test_minBound :: TestTree
 368 test_minBound =
 369   testCase desc $ actual @?= expected
 370   where
 371     desc = "minBound should be 0.0.0.0"
 372     expected = mk_testaddr 0 0 0 0
 373     actual = minBound :: IPv4Address
 374
 375
 376 test_maxBound :: TestTree
 377 test_maxBound =
 378   testCase desc $ actual @?= expected
 379   where
 380     desc = "maxBound should be 255.255.255.255"
 381     expected = mk_testaddr 255 255 255 255
 382     actual = maxBound :: IPv4Address
 383
 384
 385 test_enum :: TestTree
 386 test_enum =
 387   testCase desc $ actual @?= expected
 388   where
 389     desc = "enumerating a /24 gives the correct addresses"
 390     expected = ["192.168.0." ++ (show x) | x <- [0..255::Int] ]
 391     lb = mk_testaddr 192 168 0 0
 392     ub = mk_testaddr 192 168 0 255
 393     actual = map show [lb..ub]
 394
 395
 396 test_most_sig_bit_different1 :: TestTree
 397 test_most_sig_bit_different1 =
 398   testCase desc $ actual @?= expected
 399   where
 400     desc = "10.1.1.0 and 10.1.0.0 differ in bit 24"
 401     addr1 = mk_testaddr 10 1 1 0
 402     addr2 = (mk_testaddr 10 1 0 0)
 403     expected = TwentyFour
 404     actual = most_sig_bit_different addr1 addr2
 405
 406
 407
 408 test_most_sig_bit_different2 :: TestTree
 409 test_most_sig_bit_different2 =
 410   testCase desc $ actual @?= expected
 411   where
 412     desc = "10.1.2.0 and 10.1.1.0 differ in bit 23"
 413     addr1 = mk_testaddr 10 1 2 0
 414     addr2 = mk_testaddr 10 1 1 0
 415     expected = TwentyThree
 416     actual = most_sig_bit_different addr1 addr2
 417
 418
 419 test_to_enum :: TestTree
 420 test_to_enum =
 421   testCase desc $ actual @?= expected
 422   where
 423     desc     = "192.168.0.0 in base-10 is 3232235520"
 424     expected = mk_testaddr 192 168 0 0
 425     actual   = toEnum 3232235520