src/Maskable.hs

   1 module Maskable where
   2
   3 import Bit
   4 import IPv4Address
   5 import Maskbits
   6 import Octet
   7
   8 -- Any string of bits should be maskable by some number of netmask
   9 -- bits. The convention of the Maskable typeclass follows CIDR
  10 -- notation, where the number of mask bits (the number after the
  11 -- slash) denotes how many bits are reserved for the network.
  12 --
  13 -- So, a mask of 32 applied to an address of 127.0.0.1 will again
  14 -- return 127.0.0.1. Likewise, 31 mask bits applied to 127.0.0.1
  15 -- should return 127.0.0.0, since 127.0.0.1/31 matches both 127.0.0.0
  16 -- and 127.0.0.1. In this case, the final '0' or '1' is the host
  17 -- part of the address. The '127.0.0' is thus the network part.
  18 class Maskable a where
  19     apply_mask :: a -> Maskbits -> a
  20
  21
  22 instance Maskable Octet where
  23     apply_mask _ Maskbits.None = Octet.None
  24     apply_mask oct (Maskbits maskbits)
  25         | maskbits == 8 = oct
  26         | maskbits == 7 = oct { b8 = Zero }
  27         | maskbits == 6 = oct { b8 = Zero, b7 = Zero }
  28         | maskbits == 5 = oct { b8 = Zero, b7 = Zero, b6 = Zero }
  29         | maskbits == 4 = oct { b8 = Zero, b7 = Zero, b6 = Zero, b5 = Zero }
  30         | maskbits == 3 = oct { b8 = Zero, b7 = Zero, b6 = Zero, b5 = Zero, b4 = Zero }
  31         | maskbits == 2 = oct { b8 = Zero, b7 = Zero, b6 = Zero, b5 = Zero, b4 = Zero, b3 = Zero }
  32         | maskbits == 1 = oct { b8 = Zero, b7 = Zero, b6 = Zero, b5 = Zero, b4 = Zero, b3 = Zero, b2 = Zero }
  33         | maskbits == 0 = min_octet
  34         | otherwise = Octet.None
  35
  36
  37
  38 instance Maskable IPv4Address where
  39     apply_mask _ Maskbits.None = IPv4Address.None
  40     apply_mask addr (Maskbits mask)
  41         | mask == 32 = ipv4address_from_octets oct1 oct2 oct3 oct4
  42         | mask == 31 = ipv4address_from_octets oct1 oct2 oct3 (apply_mask oct4 (Maskbits 1))
  43         | mask == 30 = ipv4address_from_octets oct1 oct2 oct3 (apply_mask oct4 (Maskbits 2))
  44         | mask == 29 = ipv4address_from_octets oct1 oct2 oct3 (apply_mask oct4 (Maskbits 3))
  45         | mask == 28 = ipv4address_from_octets oct1 oct2 oct3 (apply_mask oct4 (Maskbits 4))
  46         | mask == 27 = ipv4address_from_octets oct1 oct2 oct3 (apply_mask oct4 (Maskbits 5))
  47         | mask == 26 = ipv4address_from_octets oct1 oct2 oct3 (apply_mask oct4 (Maskbits 6))
  48         | mask == 25 = ipv4address_from_octets oct1 oct2 oct3 (apply_mask oct4 (Maskbits 7))
  49         | mask == 24 = ipv4address_from_octets oct1 oct2 oct3 (min_octet)
  50         | mask == 23 = ipv4address_from_octets oct1 oct2 (apply_mask oct3 (Maskbits 1)) (min_octet)
  51         | mask == 22 = ipv4address_from_octets oct1 oct2 (apply_mask oct3 (Maskbits 2)) (min_octet)
  52         | mask == 21 = ipv4address_from_octets oct1 oct2 (apply_mask oct3 (Maskbits 3)) (min_octet)
  53         | mask == 20 = ipv4address_from_octets oct1 oct2 (apply_mask oct3 (Maskbits 4)) (min_octet)
  54         | mask == 19 = ipv4address_from_octets oct1 oct2 (apply_mask oct3 (Maskbits 5)) (min_octet)
  55         | mask == 18 = ipv4address_from_octets oct1 oct2 (apply_mask oct3 (Maskbits 6)) (min_octet)
  56         | mask == 17 = ipv4address_from_octets oct1 oct2 (apply_mask oct3 (Maskbits 7)) (min_octet)
  57         | mask == 16 = ipv4address_from_octets oct1 oct2 (min_octet) (min_octet)
  58         | mask == 15 = ipv4address_from_octets oct1 (apply_mask oct2 (Maskbits 1)) (min_octet) (min_octet)
  59         | mask == 14 = ipv4address_from_octets oct1 (apply_mask oct2 (Maskbits 2)) (min_octet) (min_octet)
  60         | mask == 13 = ipv4address_from_octets oct1 (apply_mask oct2 (Maskbits 3)) (min_octet) (min_octet)
  61         | mask == 12 = ipv4address_from_octets oct1 (apply_mask oct2 (Maskbits 4)) (min_octet) (min_octet)
  62         | mask == 11 = ipv4address_from_octets oct1 (apply_mask oct2 (Maskbits 5)) (min_octet) (min_octet)
  63         | mask == 10 = ipv4address_from_octets oct1 (apply_mask oct2 (Maskbits 6)) (min_octet) (min_octet)
  64         | mask == 9 = ipv4address_from_octets oct1 (apply_mask oct2 (Maskbits 7)) (min_octet) (min_octet)
  65         | mask == 8 = ipv4address_from_octets oct1 (min_octet) (min_octet) (min_octet)
  66         | mask == 7 = ipv4address_from_octets (apply_mask oct1 (Maskbits 1)) (min_octet) (min_octet) (min_octet)
  67         | mask == 6 = ipv4address_from_octets (apply_mask oct1 (Maskbits 2)) (min_octet) (min_octet) (min_octet)
  68         | mask == 5 = ipv4address_from_octets (apply_mask oct1 (Maskbits 3)) (min_octet) (min_octet) (min_octet)
  69         | mask == 4 =  ipv4address_from_octets (apply_mask oct1 (Maskbits 4)) (min_octet) (min_octet) (min_octet)
  70         | mask == 3 = ipv4address_from_octets (apply_mask oct1 (Maskbits 5)) (min_octet) (min_octet) (min_octet)
  71         | mask == 2 = ipv4address_from_octets (apply_mask oct1 (Maskbits 6)) (min_octet) (min_octet) (min_octet)
  72         | mask == 1 = ipv4address_from_octets (apply_mask oct1 (Maskbits 7)) (min_octet) (min_octet) (min_octet)
  73         | mask == 0 = ipv4address_from_octets (min_octet) (min_octet) (min_octet) (min_octet)
  74         | otherwise = IPv4Address.None
  75         where
  76           oct1 = (octet1 addr)
  77           oct2 = (octet2 addr)
  78           oct3 = (octet3 addr)
  79           oct4 = (octet4 addr)