X-Git-Url: http://gitweb.michael.orlitzky.com/?a=blobdiff_plain;f=src%2FCidr.hs;h=266b7c57f8a8e8318124a2518900de75a4d166ca;hb=7d9a55cb4f217bada3c66f585cd1ce35dc564fb1;hp=ab1ef51cce7af37bb5e3bdbec269a512ca59976f;hpb=fbd4a98a9a0996d41e3715a2698114b8a061f2cd;p=hath.git

diff --git a/src/Cidr.hs b/src/Cidr.hs
index ab1ef51..266b7c5 100644
--- a/src/Cidr.hs
+++ b/src/Cidr.hs
@@ -1,7 +1,7 @@
 module Cidr
 ( Cidr(..),
   cidr_from_string,
-  contains
+  combine_all
 ) where
 
 import IPv4Address
@@ -85,9 +85,27 @@ contains _ (Cidr IPv4Address.None _) = False
 -- address and see if the result is the same as cidr1's mask applied
 -- to cidr1's address.
 --
-contains (Cidr addr1 (Maskbits mbits1)) (Cidr addr2 (Maskbits mbits2))
+contains (Cidr addr1 mbits1) (Cidr addr2 mbits2)
     | mbits1 > mbits2 = False
     | otherwise = addr1masked == addr2masked
     where
-      addr1masked = apply_mask addr1 (Maskbits mbits1)
-      addr2masked = apply_mask addr2 (Maskbits mbits1)
+      addr1masked = apply_mask addr1 mbits1
+      addr2masked = apply_mask addr2 mbits1
+
+
+contains_proper :: Cidr -> Cidr -> Bool
+contains_proper cidr1 cidr2 =
+    (cidr1 `contains` cidr2) && (not (cidr1 == cidr2))
+
+
+-- 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
+
+
+-- We want to get rid of all the Cidrs that are properly contained
+-- in some other Cidr.
+combine_all :: [Cidr] -> [Cidr]
+combine_all cidrs =
+    filter (not . (redundant cidrs)) cidrs