X-Git-Url: http://gitweb.michael.orlitzky.com/?a=blobdiff_plain;f=src%2FCidr.hs;h=8fc014f6cf5b062f8ae019d3b990c22a9604e9b8;hb=a3c4fbd855c182390f39cdf88de36d7cb0ea69d5;hp=4bb3d48ef788656c79abf8f971a46f07f1a3a48d;hpb=9b1ce7fe8f4dc65230b223f4156760e2b9c7f098;p=hath.git

diff --git a/src/Cidr.hs b/src/Cidr.hs
index 4bb3d48..8fc014f 100644
--- a/src/Cidr.hs
+++ b/src/Cidr.hs
@@ -1,47 +1,382 @@
 module Cidr
 ( Cidr(..),
   cidr_from_string,
-  is_valid_cidr
+  cidr_tests,
+  combine_all,
+  contains,
+  contains_proper,
+  max_octet1,
+  max_octet2,
+  max_octet3,
+  max_octet4,
+  min_octet1,
+  min_octet2,
+  min_octet3,
+  min_octet4,
+  prop_all_cidrs_contain_themselves,
+  prop_contains_proper_intransitive
 ) where
 
-import Text.Regex.Posix
+import Data.List (nubBy)
+import Test.HUnit
+import Test.QuickCheck
 
+import qualified Bit as B
 import IPv4Address
 import ListUtils
+import Maskable
+import Maskbits
 import Octet
 
 
 data Cidr = None | Cidr { ipv4address :: IPv4Address,
                           maskbits :: Maskbits }
-            deriving (Eq, Show)
+            deriving (Eq)
 
--- Will return True if the passed String is in CIDR notation, False
--- otherwise.
-is_valid_cidr :: String -> Bool
-is_valid_cidr cidr = cidr =~ "([0-9]{1,3}\\.){3}[0-9]{1,3}/[0-9]{1,2}"
 
+instance Show Cidr where
+    show Cidr.None = "None"
+    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)
+
+    coarbitrary _ = variant 0
+
+
+-- Two CIDR ranges are equivalent if they have the same network bits
+-- and the masks are the same.
+equivalent :: Cidr -> Cidr -> Bool
+equivalent Cidr.None Cidr.None = True
+equivalent Cidr.None _ = False
+equivalent _ Cidr.None = False
+equivalent (Cidr addr1 mbits1) (Cidr addr2 mbits2) =
+    (mbits1 == mbits2) && ((apply_mask addr1 mbits1 B.Zero) == (apply_mask addr2 mbits2 B.Zero))
 
 -- Returns the mask portion of a CIDR address. That is, everything
 -- after the trailing slash.
-maskbits_from_string :: String -> Maskbits
-maskbits_from_string s = read ((splitWith (`elem` "/") s) !! 1)
+maskbits_from_cidr_string :: String -> Maskbits
+maskbits_from_cidr_string s =
+    maskbits_from_string ((splitWith (`elem` "/") s) !! 1)
 
 
 -- Takes an IP address String in CIDR notation, and returns a list of
 -- its octets (as Ints).
-octets_from_string :: String -> [Int]
-octets_from_string s = map read (take 4 (splitWith (`elem` "./") s))
+octets_from_cidr_string :: String -> [Octet]
+octets_from_cidr_string s =
+    map octet_from_string (take 4 (splitWith (`elem` "./") s))
 
 
 cidr_from_string :: String -> Cidr
 cidr_from_string s
-    | addr == IPv4Address.None = Cidr.None
+    | addr  == IPv4Address.None = Cidr.None
+    | mbits == Maskbits.None    = Cidr.None
     | otherwise = Cidr addr mbits
                where
                  addr = ipv4address_from_octets (oct1) (oct2) (oct3) (oct4)
-                 oct1 = octet_from_int (octs !! 0)
-                 oct2 = octet_from_int (octs !! 1)
-                 oct3 = octet_from_int (octs !! 2)
-                 oct4 = octet_from_int (octs !! 3)
-                 octs  = octets_from_string s
-                 mbits = maskbits_from_string s
+                 oct1 = (octs !! 0)
+                 oct2 = (octs !! 1)
+                 oct3 = (octs !! 2)
+                 oct4 = (octs !! 3)
+                 octs  = octets_from_cidr_string s
+                 mbits = maskbits_from_cidr_string s
+
+
+
+min_host :: Cidr -> IPv4Address
+min_host Cidr.None                 = IPv4Address.None
+min_host (Cidr IPv4Address.None _) = IPv4Address.None
+min_host (Cidr _ Maskbits.None)    = IPv4Address.None
+min_host (Cidr addr mask) = apply_mask addr mask B.Zero
+
+
+max_host :: Cidr -> IPv4Address
+max_host Cidr.None                 = IPv4Address.None
+max_host (Cidr IPv4Address.None _) = IPv4Address.None
+max_host (Cidr _ Maskbits.None)    = IPv4Address.None
+max_host (Cidr addr mask) = apply_mask addr mask B.One
+
+
+min_octet1 :: Cidr -> Octet
+min_octet1 cidr = octet1 (min_host cidr)
+
+min_octet2 :: Cidr -> Octet
+min_octet2 cidr = octet2 (min_host cidr)
+
+min_octet3 :: Cidr -> Octet
+min_octet3 cidr = octet3 (min_host cidr)
+
+min_octet4 :: Cidr -> Octet
+min_octet4 cidr = octet4 (min_host cidr)
+
+max_octet1 :: Cidr -> Octet
+max_octet1 cidr = octet1 (max_host cidr)
+
+max_octet2 :: Cidr -> Octet
+max_octet2 cidr = octet2 (max_host cidr)
+
+max_octet3 :: Cidr -> Octet
+max_octet3 cidr = octet3 (max_host cidr)
+
+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.
+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.
+--
+-- 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
+--
+-- 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.
+--
+contains (Cidr addr1 mbits1) (Cidr addr2 mbits2)
+    | mbits1 > mbits2 = False
+    | otherwise = addr1masked == addr2masked
+    where
+      addr1masked = apply_mask addr1 mbits1 B.Zero
+      addr2masked = apply_mask addr2 mbits1 B.Zero
+
+
+contains_proper :: Cidr -> Cidr -> Bool
+contains_proper 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.
+redundant :: [Cidr] -> Cidr -> Bool
+redundant cidrlist cidr = any ((flip contains_proper) cidr) cidrlist
+
+
+-- 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.
+combine_all :: [Cidr] -> [Cidr]
+combine_all cidrs =
+    combine_contained unique_cidrs
+    where
+      unique_cidrs = nubBy equivalent valid_cidr_combinations
+      valid_cidr_combinations = filter (/= Cidr.None) cidr_combinations
+      cidr_combinations =
+          cidrs ++ [ (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 -> Cidr
+combine_adjacent cidr1 cidr2
+  | not (adjacent cidr1 cidr2) = Cidr.None
+  | (maskbits cidr1 == Zero) = Cidr.None
+  | otherwise = cidr1 { maskbits = decrement (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 Cidr.None _ = False
+adjacent _ Cidr.None = False
+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
+
+
+
+
+
+-- HUnit Tests
+
+test_equality1 :: Test
+test_equality1 =
+    TestCase $ assertEqual "10.1.1.0/23 equals itself" True (cidr1 == cidr1)
+    where
+      cidr1 = cidr_from_string "10.1.1.0/23"
+
+
+test_contains1 :: Test
+test_contains1 =
+    TestCase $ assertEqual "10.1.1.0/23 contains 10.1.1.0/24" True (cidr1 `contains` cidr2)
+    where
+      cidr1 = cidr_from_string "10.1.1.0/23"
+      cidr2 = cidr_from_string "10.1.1.0/24"
+
+
+test_contains2 :: Test
+test_contains2 =
+    TestCase $ assertEqual "10.1.1.0/23 contains itself" True (cidr1 `contains` cidr1)
+    where
+      cidr1 = cidr_from_string "10.1.1.0/23"
+
+
+test_contains_proper1 :: Test
+test_contains_proper1 =
+    TestCase $ assertEqual "10.1.1.0/23 contains 10.1.1.0/24 properly" True (cidr1 `contains_proper` cidr2)
+    where
+      cidr1 = cidr_from_string "10.1.1.0/23"
+      cidr2 = cidr_from_string "10.1.1.0/24"
+
+
+test_contains_proper2 :: Test
+test_contains_proper2 =
+    TestCase $ assertEqual "10.1.1.0/23 does not contain itself properly" False (cidr1 `contains_proper` cidr1)
+    where
+      cidr1 = cidr_from_string "10.1.1.0/23"
+
+
+test_adjacent1 :: Test
+test_adjacent1 =
+    TestCase $ assertEqual "10.1.0.0/24 is adjacent to 10.1.1.0/24" True (cidr1 `adjacent` cidr2)
+    where
+      cidr1 = cidr_from_string "10.1.0.0/24"
+      cidr2 = cidr_from_string "10.1.1.0/24"
+
+
+test_adjacent2 :: Test
+test_adjacent2 =
+    TestCase $ assertEqual "10.1.0.0/23 is not adjacent to 10.1.0.0/24" False (cidr1 `adjacent` cidr2)
+    where
+      cidr1 = cidr_from_string "10.1.0.0/23"
+      cidr2 = cidr_from_string "10.1.0.0/24"
+
+
+test_adjacent3 :: Test
+test_adjacent3 =
+    TestCase $ assertEqual "10.1.0.0/24 is not adjacent to 10.2.5.0/24" False (cidr1 `adjacent` cidr2)
+    where
+      cidr1 = cidr_from_string "10.1.0.0/24"
+      cidr2 = cidr_from_string "10.2.5.0/24"
+
+
+test_adjacent4 :: Test
+test_adjacent4 =
+    TestCase $ assertEqual "10.1.1.0/24 is not adjacent to 10.1.2.0/24" False (cidr1 `adjacent` cidr2)
+    where
+      cidr1 = cidr_from_string "10.1.1.0/24"
+      cidr2 = cidr_from_string "10.1.2.0/24"
+
+
+test_combine_contained1 :: Test
+test_combine_contained1 =
+    TestCase $ assertEqual "10.0.0.0/8, 10.1.0.0/16, and 10.1.1.0/24 combine to 10.0.0.0/8" expected_cidrs (combine_contained test_cidrs)
+    where
+      cidr1 = cidr_from_string "10.0.0.0/8"
+      cidr2 = cidr_from_string "10.1.0.0/16"
+      cidr3 = cidr_from_string "10.1.1.0/24"
+      expected_cidrs = [cidr1]
+      test_cidrs = [cidr1, cidr2, cidr3]
+
+
+test_combine_contained2 :: Test
+test_combine_contained2 =
+    TestCase $ assertEqual "192.168.3.0/23 does not contain 192.168.1.0/24" [cidr1, cidr2] (combine_contained [cidr1, cidr2])
+    where
+      cidr1 = cidr_from_string "192.168.3.0/23"
+      cidr2 = cidr_from_string "192.168.1.0/24"
+
+
+test_combine_all1 :: Test
+test_combine_all1 =
+    TestCase $ assertEqual "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" expected_cidrs (combine_all test_cidrs)
+    where
+      cidr1 = cidr_from_string "10.0.0.0/24"
+      cidr2 = cidr_from_string "10.0.1.0/24"
+      cidr3 = cidr_from_string "10.0.2.0/24"
+      cidr4 = cidr_from_string "10.0.3.0/23"
+      cidr5 = cidr_from_string "10.0.0.0/23"
+      expected_cidrs = [cidr4, cidr5]
+      test_cidrs = [cidr1, cidr2, cidr3, cidr4]
+
+
+test_combine_all2 :: Test
+test_combine_all2 =
+    TestCase $ assertEqual "127.0.0.1/32 combines with itself recursively" expected_cidrs (combine_all test_cidrs)
+    where
+      cidr1 = cidr_from_string "127.0.0.1/32"
+      expected_cidrs = [cidr1]
+      test_cidrs = [cidr1, cidr1, cidr1, cidr1, cidr1]
+
+
+cidr_tests :: [Test]
+cidr_tests = [ 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
+             ]
+
+
+-- QuickCheck Tests
+prop_all_cidrs_contain_themselves :: Cidr -> Bool
+prop_all_cidrs_contain_themselves cidr1 = cidr1 `contains` cidr1
+
+
+-- If cidr1 properly contains cidr2, then by definition cidr2
+-- does not properly contain cidr1.
+prop_contains_proper_intransitive :: Cidr -> Cidr -> Property
+prop_contains_proper_intransitive cidr1 cidr2 =
+    (cidr1 `contains_proper` cidr2) ==>
+      (not (cidr2 `contains_proper` cidr1))