4 import Data.Maybe (fromJust)
6 import Test.HUnit (assertEqual)
7 import Test.Framework (Test, testGroup)
8 import Test.Framework.Providers.HUnit (testCase)
10 import Test.QuickCheck (Arbitrary(..), Gen)
16 -- | An Octet consists of eight bits. For our purposes, the most
17 -- significant bit will come "first." That is, b1 is in the 2^7
18 -- place while b8 is in the 2^0 place.
31 instance Show Octet where
32 show oct = show (octet_to_int oct)
35 instance Arbitrary Octet where
37 a1 <- arbitrary :: Gen Bit
38 a2 <- arbitrary :: Gen Bit
39 a3 <- arbitrary :: Gen Bit
40 a4 <- arbitrary :: Gen Bit
41 a5 <- arbitrary :: Gen Bit
42 a6 <- arbitrary :: Gen Bit
43 a7 <- arbitrary :: Gen Bit
44 a8 <- arbitrary :: Gen Bit
45 return (Octet a1 a2 a3 a4 a5 a6 a7 a8)
48 instance Maskable Octet where
49 apply_mask oct Eight _ = oct
51 apply_mask oct Seven bit =
54 apply_mask oct Six bit =
55 oct { b8 = bit, b7 = bit }
57 apply_mask oct Five bit =
58 oct { b8 = bit, b7 = bit, b6 = bit }
60 apply_mask oct Four bit =
61 oct { b8 = bit, b7 = bit, b6 = bit, b5 = bit }
63 apply_mask oct Three bit =
64 oct { b8 = bit, b7 = bit, b6 = bit, b5 = bit, b4 = bit }
66 apply_mask oct Two bit =
67 oct { b8 = bit, b7 = bit, b6 = bit, b5 = bit, b4 = bit, b3 = bit }
69 apply_mask oct Maskbits.One bit =
70 oct { b8 = bit, b7 = bit, b6 = bit, b5 = bit,
71 b4 = bit, b3 = bit, b2 = bit }
73 apply_mask oct Maskbits.Zero bit =
74 oct { b8 = bit, b7 = bit, b6 = bit, b5 = bit,
75 b4 = bit, b3 = bit, b2 = bit, b1 = bit }
77 -- The Maskbits must be in [Eight..ThirtyTwo].
78 apply_mask oct _ _ = oct
81 -- | Convert each bit to its integer value, and multiply by the
82 -- appropriate power of two. Sum them up, and we should get an integer
84 octet_to_int :: Octet -> Int
86 128 * (bit_to_int (b1 x)) +
87 64 * (bit_to_int (b2 x)) +
88 32 * (bit_to_int (b3 x)) +
89 16 * (bit_to_int (b4 x)) +
90 8 * (bit_to_int (b5 x)) +
91 4 * (bit_to_int (b6 x)) +
92 2 * (bit_to_int (b7 x)) +
93 1 * (bit_to_int (b8 x))
97 octet_from_int :: Int -> Maybe Octet
99 | (x < 0) || (x > 255) = Nothing
100 | otherwise = Just (Octet a1 a2 a3 a4 a5 a6 a7 a8)
102 a1 = if (x >= 128) then B.One else B.Zero
103 a2 = if ((x `mod` 128) >= 64) then B.One else B.Zero
104 a3 = if ((x `mod` 64) >= 32) then B.One else B.Zero
105 a4 = if ((x `mod` 32) >= 16) then B.One else B.Zero
106 a5 = if ((x `mod` 16) >= 8) then B.One else B.Zero
107 a6 = if ((x `mod` 8) >= 4) then B.One else B.Zero
108 a7 = if ((x `mod` 4) >= 2) then B.One else B.Zero
109 a8 = if ((x `mod` 2) == 1) then B.One else B.Zero
112 octet_from_string :: String -> Maybe Octet
113 octet_from_string s =
114 case (reads s :: [(Int, String)]) of
116 x:_ -> octet_from_int (fst x)
119 -- | The octet with the least possible value.
122 Octet B.Zero B.Zero B.Zero B.Zero B.Zero B.Zero B.Zero B.Zero
125 -- | The octet with the greatest possible value.
128 Octet B.One B.One B.One B.One B.One B.One B.One B.One
133 test_octet_from_int1 :: Test
134 test_octet_from_int1 =
135 testCase desc $ assertEqual desc oct1 oct2
137 desc = "octet_from_int 128 should parse as 10000000"
138 oct1 = Octet B.One B.Zero B.Zero B.Zero B.Zero B.Zero B.Zero B.Zero
139 oct2 = fromJust $ octet_from_int 128
141 test_octet_mask1 :: Test
144 assertEqual desc oct2 (apply_mask oct1 Four B.Zero)
146 desc = "The network bits of 255/4 should equal 240"
147 oct1 = fromJust $ octet_from_int 255
148 oct2 = fromJust $ octet_from_int 240
151 test_octet_mask2 :: Test
154 assertEqual desc oct2 (apply_mask oct1 Maskbits.One B.Zero)
156 desc = "The network bits of 255/1 should equal 128"
157 oct1 = fromJust $ octet_from_int 255
158 oct2 = fromJust $ octet_from_int 128
163 testGroup "Octet Tests" [
164 test_octet_from_int1,