16 prop_all_cidrs_contain_themselves,
17 prop_contains_proper_intransitive
20 import Data.List (nubBy)
22 import Test.QuickCheck
24 import qualified Bit as B
32 data Cidr = None | Cidr { ipv4address :: IPv4Address,
33 maskbits :: Maskbits }
37 instance Show Cidr where
38 show Cidr.None = "None"
39 show cidr = (show (ipv4address cidr)) ++ "/" ++ (show (maskbits cidr))
42 instance Arbitrary Cidr where
44 ipv4 <- arbitrary :: Gen IPv4Address
45 mask <- arbitrary :: Gen Maskbits
46 return (Cidr ipv4 mask)
48 coarbitrary _ = variant 0
51 -- Two CIDR ranges are equivalent if they have the same network bits
52 -- and the masks are the same.
53 equivalent :: Cidr -> Cidr -> Bool
54 equivalent Cidr.None Cidr.None = True
55 equivalent Cidr.None _ = False
56 equivalent _ Cidr.None = False
57 equivalent (Cidr addr1 mbits1) (Cidr addr2 mbits2) =
58 (mbits1 == mbits2) && ((apply_mask addr1 mbits1) == (apply_mask addr2 mbits2))
60 -- Returns the mask portion of a CIDR address. That is, everything
61 -- after the trailing slash.
62 maskbits_from_cidr_string :: String -> Maskbits
63 maskbits_from_cidr_string s =
64 maskbits_from_string ((splitWith (`elem` "/") s) !! 1)
67 -- Takes an IP address String in CIDR notation, and returns a list of
68 -- its octets (as Ints).
69 octets_from_cidr_string :: String -> [Octet]
70 octets_from_cidr_string s =
71 map octet_from_string (take 4 (splitWith (`elem` "./") s))
74 cidr_from_string :: String -> Cidr
76 | addr == IPv4Address.None = Cidr.None
77 | mbits == Maskbits.None = Cidr.None
78 | otherwise = Cidr addr mbits
80 addr = ipv4address_from_octets (oct1) (oct2) (oct3) (oct4)
85 octs = octets_from_cidr_string s
86 mbits = maskbits_from_cidr_string s
90 min_host :: Cidr -> IPv4Address
91 min_host Cidr.None = IPv4Address.None
92 min_host (Cidr IPv4Address.None _) = IPv4Address.None
93 min_host (Cidr _ Maskbits.None) = IPv4Address.None
94 min_host (Cidr addr mask)
95 | mask == ThirtyTwo = addr
96 | mask == ThirtyOne = addr { octet4 = apply_mask oct4 Seven }
97 | mask == Thirty = addr { octet4 = apply_mask oct4 Six }
98 | mask == TwentyNine = addr { octet4 = apply_mask oct4 Five }
99 | mask == TwentyEight = addr { octet4 = apply_mask oct4 Four }
100 | mask == TwentySeven = addr { octet4 = apply_mask oct4 Three }
101 | mask == TwentySix = addr { octet4 = apply_mask oct4 Two }
102 | mask == TwentyFive = addr { octet4 = apply_mask oct4 One }
103 | mask == TwentyFour = addr { octet4 = min_octet }
104 | mask == TwentyThree = addr { octet3 = apply_mask oct3 Seven,
106 | mask == TwentyTwo = addr { octet3 = apply_mask oct3 Six,
108 | mask == TwentyOne = addr { octet3 = apply_mask oct3 Five,
110 | mask == Twenty = addr { octet3 = apply_mask oct3 Four,
112 | mask == Nineteen = addr { octet3 = apply_mask oct3 Three,
114 | mask == Eighteen = addr { octet3 = apply_mask oct3 Two,
116 | mask == Seventeen = addr { octet3 = apply_mask oct3 One,
118 | mask == Sixteen = addr { octet3 = min_octet,
120 | mask == Fifteen = addr { octet2 = apply_mask oct2 Seven,
123 | mask == Fourteen = addr { octet2 = apply_mask oct2 Six,
126 | mask == Thirteen = addr { octet2 = apply_mask oct2 Five,
129 | mask == Twelve = addr { octet2 = apply_mask oct2 Four,
132 | mask == Eleven = addr { octet2 = apply_mask oct2 Three,
135 | mask == Ten = addr { octet2 = apply_mask oct2 Two,
138 | mask == Nine = addr { octet2 = apply_mask oct2 One,
141 | mask == Eight = addr { octet2 = min_octet,
144 | mask == Seven = addr { octet1 = apply_mask oct1 Seven,
148 | mask == Six = addr { octet1 = apply_mask oct1 Six,
152 | mask == Five = addr { octet1 = apply_mask oct1 Five,
156 | mask == Four = addr { octet1 = apply_mask oct1 Four,
160 | mask == Three = addr { octet1 = apply_mask oct1 Three,
164 | mask == Two = addr { octet1 = apply_mask oct1 Two,
168 | mask == One = addr { octet1 = apply_mask oct1 One,
172 | mask == Zero = addr { octet1 = min_octet,
185 max_host :: Cidr -> IPv4Address
186 max_host Cidr.None = IPv4Address.None
187 max_host (Cidr IPv4Address.None _) = IPv4Address.None
188 max_host (Cidr _ Maskbits.None) = IPv4Address.None
189 max_host (Cidr addr mask)
190 | mask == ThirtyTwo = addr
191 | mask == ThirtyOne = addr { octet4 = oct4 { b8 = B.One } }
192 | mask == Thirty = addr { octet4 = oct4 { b7 = B.One, b8 = B.One } }
193 | mask == TwentyNine = addr { octet4 = oct4 { b6 = B.One,
196 | mask == TwentyEight = addr { octet4 = oct4 { b5 = B.One,
200 | mask == TwentySeven = addr { octet4 = oct4 { b4 = B.One,
205 | mask == TwentySix = addr { octet4 = oct4 { b3 = B.One,
211 | mask == TwentyFive = addr { octet4 = oct4 { b2 = B.One,
218 | mask == TwentyFour = addr { octet4 = max_octet }
219 | mask == TwentyThree = ipv4address_from_octets oct1 oct2 (Octet a17 a18 a19 a20 a21 a22 a23 B.One) (max_octet)
220 | mask == TwentyTwo = ipv4address_from_octets oct1 oct2 (Octet a17 a18 a19 a20 a21 a22 B.One B.One) (max_octet)
221 | mask == TwentyOne = ipv4address_from_octets oct1 oct2 (Octet a17 a18 a19 a20 a21 B.One B.One B.One) (max_octet)
222 | mask == Twenty = ipv4address_from_octets oct1 oct2 (Octet a17 a18 a19 a20 B.One B.One B.One B.One) (max_octet)
223 | mask == Nineteen = ipv4address_from_octets oct1 oct2 (Octet a17 a18 a19 B.One B.One B.One B.One B.One) (max_octet)
224 | mask == Eighteen = ipv4address_from_octets oct1 oct2 (Octet a17 a18 B.One B.One B.One B.One B.One B.One) (max_octet)
225 | mask == Seventeen = ipv4address_from_octets oct1 oct2 (Octet a17 B.One B.One B.One B.One B.One B.One B.One) (max_octet)
226 | mask == Sixteen = ipv4address_from_octets oct1 oct2 (max_octet) (max_octet)
227 | mask == Fifteen = ipv4address_from_octets oct1 (Octet a9 a10 a11 a12 a13 a14 a15 B.One) (max_octet) (max_octet)
228 | mask == Fourteen = ipv4address_from_octets oct1 (Octet a9 a10 a11 a12 a13 a14 B.One B.One) (max_octet) (max_octet)
229 | mask == Thirteen = ipv4address_from_octets oct1 (Octet a9 a10 a11 a12 a13 B.One B.One B.One) (max_octet) (max_octet)
230 | mask == Twelve = ipv4address_from_octets oct1 (Octet a9 a10 a11 a12 B.One B.One B.One B.One) (max_octet) (max_octet)
231 | mask == Eleven = ipv4address_from_octets oct1 (Octet a9 a10 a11 B.One B.One B.One B.One B.One) (max_octet) (max_octet)
232 | mask == Ten = ipv4address_from_octets oct1 (Octet a9 a10 B.One B.One B.One B.One B.One B.One) (max_octet) (max_octet)
233 | mask == Nine = ipv4address_from_octets oct1 (Octet a9 B.One B.One B.One B.One B.One B.One B.One) (max_octet) (max_octet)
234 | mask == Eight = ipv4address_from_octets oct1 (max_octet) (max_octet) (max_octet)
235 | mask == Seven = ipv4address_from_octets (Octet a1 a2 a3 a4 a5 a6 a7 B.One) (max_octet) (max_octet) (max_octet)
236 | mask == Six = ipv4address_from_octets (Octet a1 a2 a3 a4 a5 a6 B.One B.One) (max_octet) (max_octet) (max_octet)
237 | mask == Five = ipv4address_from_octets (Octet a1 a2 a3 a4 a5 B.One B.One B.One) (max_octet) (max_octet) (max_octet)
238 | mask == Four = ipv4address_from_octets (Octet a1 a2 a3 a4 B.One B.One B.One B.One) (max_octet) (max_octet) (max_octet)
239 | mask == Three = ipv4address_from_octets (Octet a1 a2 a3 B.One B.One B.One B.One B.One) (max_octet) (max_octet) (max_octet)
240 | mask == Two = ipv4address_from_octets (Octet a1 a2 B.One B.One B.One B.One B.One B.One) (max_octet) (max_octet) (max_octet)
241 | mask == One = ipv4address_from_octets (Octet a1 B.One B.One B.One B.One B.One B.One B.One) (max_octet) (max_octet) (max_octet)
242 | mask == Zero = ipv4address_from_octets (max_octet) (max_octet) (max_octet) (max_octet)
273 min_octet1 :: Cidr -> Octet
274 min_octet1 cidr = octet1 (min_host cidr)
276 min_octet2 :: Cidr -> Octet
277 min_octet2 cidr = octet2 (min_host cidr)
279 min_octet3 :: Cidr -> Octet
280 min_octet3 cidr = octet3 (min_host cidr)
282 min_octet4 :: Cidr -> Octet
283 min_octet4 cidr = octet4 (min_host cidr)
285 max_octet1 :: Cidr -> Octet
286 max_octet1 cidr = octet1 (max_host cidr)
288 max_octet2 :: Cidr -> Octet
289 max_octet2 cidr = octet2 (max_host cidr)
291 max_octet3 :: Cidr -> Octet
292 max_octet3 cidr = octet3 (max_host cidr)
294 max_octet4 :: Cidr -> Octet
295 max_octet4 cidr = octet4 (max_host cidr)
299 -- Return true if the first argument (a CIDR range) contains the
300 -- second (another CIDR range). There are a lot of ways we can be fed
301 -- junk here. For lack of a better alternative, just return False when
302 -- we are given nonsense.
303 contains :: Cidr -> Cidr -> Bool
304 contains Cidr.None _ = False
305 contains _ Cidr.None = False
306 contains (Cidr _ Maskbits.None) _ = False
307 contains (Cidr IPv4Address.None _) _ = False
308 contains _ (Cidr _ Maskbits.None) = False
309 contains _ (Cidr IPv4Address.None _) = False
311 -- If the number of bits in the network part of the first address is
312 -- larger than the number of bits in the second, there is no way that
313 -- the first range can contain the second. For, if the number of
314 -- network bits is larger, then the number of host bits must be
315 -- smaller, and if cidr1 has fewer hosts than cidr2, cidr1 most
316 -- certainly does not contain cidr2.
318 -- On the other hand, if the first argument (cidr1) has fewer (or the
319 -- same number of) network bits as the second, it can contain the
320 -- second. In this case, we need to check that every host in cidr2 is
321 -- contained in cidr1. If a host in cidr2 is contained in cidr1, then
322 -- at least mbits1 of an address in cidr2 will match cidr1. For
325 -- cidr1 = 192.168.1.0/23, cidr2 = 192.168.1.100/24
327 -- Here, cidr2 contains all of 192.168.1.0 through
328 -- 192.168.1.255. However, cidr1 contains BOTH 192.168.0.0 through
329 -- 192.168.0.255 and 192.168.1.0 through 192.168.1.255. In essence,
330 -- what we want to check is that cidr2 "begins with" something that
331 -- cidr1 CAN begin with. Since cidr1 can begin with 192.168.1, and
332 -- cidr2 DOES, cidr1 contains cidr2..
334 -- The way that we check this is to apply cidr1's mask to cidr2's
335 -- address and see if the result is the same as cidr1's mask applied
336 -- to cidr1's address.
338 contains (Cidr addr1 mbits1) (Cidr addr2 mbits2)
339 | mbits1 > mbits2 = False
340 | otherwise = addr1masked == addr2masked
342 addr1masked = apply_mask addr1 mbits1
343 addr2masked = apply_mask addr2 mbits1
346 contains_proper :: Cidr -> Cidr -> Bool
347 contains_proper cidr1 cidr2 =
348 (cidr1 `contains` cidr2) && (not (cidr2 `contains` cidr1))
351 -- A CIDR range is redundant (with respect to the given list) if
352 -- another CIDR range in that list properly contains it.
353 redundant :: [Cidr] -> Cidr -> Bool
354 redundant cidrlist cidr = any ((flip contains_proper) cidr) cidrlist
357 -- First, we look at all possible pairs of cidrs, and combine the
358 -- adjacent ones in to a new list. Then, we concatenate that list with
359 -- the original one, and filter out all of the redundancies. If two
360 -- adjacent Cidrs are combined into a larger one, they will be removed
361 -- in the second step since the larger Cidr must contain the smaller
363 combine_all :: [Cidr] -> [Cidr]
365 combine_contained unique_cidrs
367 unique_cidrs = nubBy equivalent valid_cidr_combinations
368 valid_cidr_combinations = filter (/= Cidr.None) cidr_combinations
370 cidrs ++ [ (combine_adjacent x y) | x <- cidrs, y <- cidrs ]
373 -- Take a list of CIDR ranges and filter out all of the ones that are
374 -- contained entirelt within some other range in the list.
375 combine_contained :: [Cidr] -> [Cidr]
376 combine_contained cidrs =
377 filter (not . (redundant cidrs)) cidrs
380 -- If the two Cidrs are not adjacent, return Cidr.None. Otherwise,
381 -- decrement the maskbits of cidr1 and return that; it will contain
382 -- both cidr1 and cidr2.
383 combine_adjacent :: Cidr -> Cidr -> Cidr
384 combine_adjacent cidr1 cidr2
385 | not (adjacent cidr1 cidr2) = Cidr.None
386 | (maskbits cidr1 == Zero) = Cidr.None
387 | otherwise = cidr1 { maskbits = decrement (maskbits cidr1) }
391 -- Determine whether or not two CIDR ranges are adjacent. If two
392 -- ranges lie consecutively within the IP space, they can be
393 -- combined. For example, 10.1.0.0/24 and 10.0.1.0/24 are adjacent,
394 -- and can be combined in to 10.1.0.0/23.
395 adjacent :: Cidr -> Cidr -> Bool
396 adjacent Cidr.None _ = False
397 adjacent _ Cidr.None = False
399 | mbits1 /= mbits2 = False
400 | mbits1 == Maskbits.Zero = False -- They're equal.
401 | otherwise = (mbits1 == (most_sig_bit_different addr1 addr2))
403 addr1 = ipv4address cidr1
404 addr2 = ipv4address cidr2
405 mbits1 = maskbits cidr1
406 mbits2 = maskbits cidr2
414 test_equality1 :: Test
416 TestCase $ assertEqual "10.1.1.0/23 equals itself" True (cidr1 == cidr1)
418 cidr1 = cidr_from_string "10.1.1.0/23"
421 test_contains1 :: Test
423 TestCase $ assertEqual "10.1.1.0/23 contains 10.1.1.0/24" True (cidr1 `contains` cidr2)
425 cidr1 = cidr_from_string "10.1.1.0/23"
426 cidr2 = cidr_from_string "10.1.1.0/24"
429 test_contains2 :: Test
431 TestCase $ assertEqual "10.1.1.0/23 contains itself" True (cidr1 `contains` cidr1)
433 cidr1 = cidr_from_string "10.1.1.0/23"
436 test_contains_proper1 :: Test
437 test_contains_proper1 =
438 TestCase $ assertEqual "10.1.1.0/23 contains 10.1.1.0/24 properly" True (cidr1 `contains_proper` cidr2)
440 cidr1 = cidr_from_string "10.1.1.0/23"
441 cidr2 = cidr_from_string "10.1.1.0/24"
444 test_contains_proper2 :: Test
445 test_contains_proper2 =
446 TestCase $ assertEqual "10.1.1.0/23 does not contain itself properly" False (cidr1 `contains_proper` cidr1)
448 cidr1 = cidr_from_string "10.1.1.0/23"
451 test_adjacent1 :: Test
453 TestCase $ assertEqual "10.1.0.0/24 is adjacent to 10.1.1.0/24" True (cidr1 `adjacent` cidr2)
455 cidr1 = cidr_from_string "10.1.0.0/24"
456 cidr2 = cidr_from_string "10.1.1.0/24"
459 test_adjacent2 :: Test
461 TestCase $ assertEqual "10.1.0.0/23 is not adjacent to 10.1.0.0/24" False (cidr1 `adjacent` cidr2)
463 cidr1 = cidr_from_string "10.1.0.0/23"
464 cidr2 = cidr_from_string "10.1.0.0/24"
467 test_adjacent3 :: Test
469 TestCase $ assertEqual "10.1.0.0/24 is not adjacent to 10.2.5.0/24" False (cidr1 `adjacent` cidr2)
471 cidr1 = cidr_from_string "10.1.0.0/24"
472 cidr2 = cidr_from_string "10.2.5.0/24"
475 test_adjacent4 :: Test
477 TestCase $ assertEqual "10.1.1.0/24 is not adjacent to 10.1.2.0/24" False (cidr1 `adjacent` cidr2)
479 cidr1 = cidr_from_string "10.1.1.0/24"
480 cidr2 = cidr_from_string "10.1.2.0/24"
483 test_combine_contained1 :: Test
484 test_combine_contained1 =
485 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)
487 cidr1 = cidr_from_string "10.0.0.0/8"
488 cidr2 = cidr_from_string "10.1.0.0/16"
489 cidr3 = cidr_from_string "10.1.1.0/24"
490 expected_cidrs = [cidr1]
491 test_cidrs = [cidr1, cidr2, cidr3]
494 test_combine_contained2 :: Test
495 test_combine_contained2 =
496 TestCase $ assertEqual "192.168.3.0/23 does not contain 192.168.1.0/24" [cidr1, cidr2] (combine_contained [cidr1, cidr2])
498 cidr1 = cidr_from_string "192.168.3.0/23"
499 cidr2 = cidr_from_string "192.168.1.0/24"
502 test_combine_all1 :: Test
504 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)
506 cidr1 = cidr_from_string "10.0.0.0/24"
507 cidr2 = cidr_from_string "10.0.1.0/24"
508 cidr3 = cidr_from_string "10.0.2.0/24"
509 cidr4 = cidr_from_string "10.0.3.0/23"
510 cidr5 = cidr_from_string "10.0.0.0/23"
511 expected_cidrs = [cidr4, cidr5]
512 test_cidrs = [cidr1, cidr2, cidr3, cidr4]
515 test_combine_all2 :: Test
517 TestCase $ assertEqual "127.0.0.1/32 combines with itself recursively" expected_cidrs (combine_all test_cidrs)
519 cidr1 = cidr_from_string "127.0.0.1/32"
520 expected_cidrs = [cidr1]
521 test_cidrs = [cidr1, cidr1, cidr1, cidr1, cidr1]
525 cidr_tests = [ test_equality1,
528 test_contains_proper1,
529 test_contains_proper2,
534 test_combine_contained1,
535 test_combine_contained2,
542 prop_all_cidrs_contain_themselves :: Cidr -> Bool
543 prop_all_cidrs_contain_themselves cidr1 = cidr1 `contains` cidr1
546 -- If cidr1 properly contains cidr2, then by definition cidr2
547 -- does not properly contain cidr1.
548 prop_contains_proper_intransitive :: Cidr -> Cidr -> Property
549 prop_contains_proper_intransitive cidr1 cidr2 =
550 (cidr1 `contains_proper` cidr2) ==>
551 (not (cidr2 `contains_proper` cidr1))