aboutsummaryrefslogtreecommitdiffstats
path: root/lua/inet/init.lua
blob: fcdabe9153e2ccd35e4899ad9b23580033f31421 (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
-- ipv4 / 24 = network
-- ipv6/56 * 5 = 5 /56 further down

local bit32 = require 'bit32'

local inet, inet4, inet6

inet = {}
inet.__index = inet

function inet.new(ip, mask)
	local ipv6 = string.find(ip, ':', 1, true)
	if ipv6 then
		return inet6.new(ip, mask)
	else
		return inet4.new(ip, mask)
	end
end

function inet:__len()
	return self.mask
end

local lshift = bit32.lshift
local rshift = bit32.rshift
local band = bit32.band
local replace = bit32.replace
local bxor = bit32.bxor

inet4 = {}
inet4.__index = inet4
inet4.__len = inet.__len

local ipv4_parser
local ipv6_parser
do
	local lpeg = require 'lpeg'
	local C, Ct = lpeg.C, lpeg.Ct
	local S, R = lpeg.S, lpeg.R
	local B, Cc = lpeg.B, lpeg.Cc

	local digit = R('09')

	do
		local dot = S('.')
		local zero = S('0')
		local octet0 = B(zero) * Cc('0')
		local octet1 = R('19')
		local octet2 = R('19') * digit
		local octet31 = S('1') * digit * digit
		local octet32 = R('04') * digit
		local octet325 = S('5') * R('05')
		local octet3 = octet31 + (S('2') * (octet32 + octet325))
		local octet = zero^0 * (C(octet3 + octet2 + octet1) + octet0)
		local ipv4 = octet * dot * octet * dot * octet * dot * octet
		local mask12 = R('12') * digit
		local mask3 = S('3') * R('02')
		local netmask = S('/') * C(mask12 + mask3 + digit)
		ipv4_parser = ipv4 * (netmask + C('')) * -1
	end

	do
		local function hextonumber(hex) return tonumber(hex, 16) end
		local hexdigit = R('09') + R('af') + R('AF')
		local piece = C(hexdigit * (hexdigit^-3)) / hextonumber
		local col = S(':')
		local colcol = C(col * col)
		local picol = piece * col
		local colpi = col * piece
		local full = picol * picol * picol * picol * picol * picol * picol * piece
		local partial = (piece * (colpi^-6))^-1 * colcol * ((picol^-6)*piece)^-1
		local netmask = S('/') * C((digit^-3)) / tonumber
		ipv6_parser = Ct(full + partial) * ((netmask + C(''))^-1) * -1
	end
end

local function parse4(ipstr)
	local o1, o2, o3, o4, mask = ipv4_parser:match(ipstr)
	if o1 == nil then return nil end

	local bip = lshift(o1, 24) + lshift(o2, 16) + lshift(o3, 8) + o4
	return bip, tonumber(mask)
end

function inet4.new(ip, mask)
	local bip, ourmask
	if type(ip) == 'string' then
		bip, ourmask = parse4(ip)
		if bip == nil then
			return nil
		end
	elseif type(ip) == 'number' then
		bip = ip
	end
	if mask then
		if type(mask) == 'number' and mask >= 0 and mask <= 32 then
			ourmask = mask
		else
			error('invalid mask')
		end
	else
		if not ourmask then
			ourmask = 32
		end
	end
	return setmetatable({
		bip = bip,
		mask = ourmask,
	}, inet4)
end

local function tostr4(self, withmask)
	-- return human readable
	local bip, mask = self.bip, self.mask
	local o1, o2, o3, o4
	o1 = band(rshift(bip, 24), 0xff)
	o2 = band(rshift(bip, 16), 0xff)
	o3 = band(rshift(bip, 8), 0xff)
	o4 = band(bip, 0xff)
	if (mask == nil or mask == 32 or withmask == false) and withmask ~= true then
		return string.format('%d.%d.%d.%d', o1, o2, o3, o4)
	else
		return string.format('%d.%d.%d.%d/%d', o1, o2, o3, o4, mask)
	end
end

function inet4:__tostring()
	return tostr4(self)
end

function inet4:ipstring()
	return tostr4(self, false)
end

function inet4:cidrstring()
	return tostr4(self, true)
end

function inet4:__add(n)
	return inet4.new(self.bip + n, self.mask)
end

function inet4:__sub(n)
	return inet4.new(self.bip - n, self.mask)
end

function inet4:__mul(n)
	local new = self.bip + (n * math.pow(2, 32 - self.mask))
	return inet4.new(new, self.mask)
end

function inet4:__div(n)
	return inet4.new(self.bip, n)
end

function inet4:__pow(n)
	return inet4.new(self.bip, self.mask + n)
end

function inet4:__lt(other)
	if self.mask <= other.mask then
		return false
	end
	local mask = other.mask
	local selfnet = replace(self.bip, 0, 0, 32-mask)
	local othernet = replace(other.bip, 0, 0, 32-mask)
	return selfnet == othernet
end

function inet4:__le(other)
	if self.mask < other.mask then
		return false
	end
	local mask = other.mask
	if mask == 32 then
		return self.bip == other.bip
	else
		local selfnet = replace(self.bip, 0, 0, 32-mask)
		local othernet = replace(other.bip, 0, 0, 32-mask)
		return selfnet == othernet
	end
end

function inet4:__eq(other)
	return self.bip == other.bip and self.mask == other.mask
end

function inet4:network()
	local hostbits = 32 - self.mask
	return inet4.new(lshift(rshift(self.bip, hostbits), hostbits), self.mask)
end

function inet4:netmask()
	local hostbits = 32 - self.mask
	return inet4.new(replace(0xffffffff, 0, 0, hostbits), 32)
end

function inet4:flip()
	-- find twin by flipping the last network bit
	local mask = self.mask
	if mask == 0 then return nil end
	local hostbits = 32 - mask
	local flipbit = lshift(1, hostbits)
	return inet4.new(bxor(self.bip, flipbit), mask)
end

local function parse6(ipstr)
	local pcs, netmask = ipv6_parser:match(ipstr)
	if not pcs then return nil end
	if #pcs > 8 then return nil, 'too many pieces' end
	local zero_pieces = 8 - #pcs
	for i=1,#pcs do
		if pcs[i] == '::' then
			pcs[i] = 0
			for j=1,#pcs-i do
				pcs[i+j+zero_pieces] = pcs[i+j]
			end
			for j=1,zero_pieces do
				pcs[i+j] = 0
			end
		end
	end
	if #pcs > 8 then return nil, 'too many pieces' end
	if netmask == '' then
		netmask = 128
	elseif netmask > 128 then
		return nil, 'invalid netmask'
	end
	return pcs, netmask
end

inet6 = setmetatable({}, inet)
inet6.__index = inet6
inet6.__len = inet.__len

function inet6.new(ip, netmask)
	local pcs, err
	if type(ip) == 'string' then
		pcs, err = parse6(ip)
		if pcs == nil then
			return nil, err
		end
		if not netmask then
			netmask = err
		end
	elseif type(ip) == 'table' then
		pcs = { ip[1], ip[2], ip[3], ip[4],
		        ip[5], ip[6], ip[7], ip[8] }
		if not netmask then
			netmask = 128
		end
	else
		return nil
	end

	local r = setmetatable({
		pcs = pcs,
		mask = netmask,
	}, inet6)

	-- ensure that the result is balanced
	if not r:is_balanced() then
		r:balance()
		return nil, tostring(r)..' unbalanced'
	end

	return r
end

-- each ipv6 address is stored as eight pieces
-- 1111:2222:3333:4444:5555:6666:7777:8888
-- in the table pcs.

function inet6:is_balanced()
	local pcs = self.pcs
	local i = 8
	for i=i,8 do
		local piece = pcs[i]
		if piece < 0 or piece > 0xffff then
			return false
		end
	end
	return true
end

function inet6:balance(quick)
	local pcs = self.pcs
	local i = 8
	while i > 1 do
		if quick and pcs[i] > 0 then
			break
		end
		while pcs[i] < 0 do
			pcs[i] = pcs[i] + 0x10000
			pcs[i-1] = pcs[i-1] - 1
		end
		i = i - 1
	end
	i = 8
	while i > 1 do
		local extra = rshift(pcs[i], 16)
		if quick and extra == 0 then
			break
		end
		pcs[i] = band(pcs[i], 0xffff)
		pcs[i-1] = pcs[i-1] + extra
		i = i - 1
	end
	pcs[1] = band(pcs[1], 0xffff)
	return self
end

local function tostr6(self, withmask)
	-- return human readable
	local pcs = self.pcs
	local zeros = {}

	-- count zero clusters
	local first_zero = 0
	local prev_was_zero = false
	for i=1,#pcs do
		if pcs[i] == 0 then
			if prev_was_zero then
				zeros[first_zero] = zeros[first_zero] + 1
			else
				first_zero = i
				zeros[first_zero] = 1
			end
			prev_was_zero = true
		else
			prev_was_zero = false
		end
	end

	-- find the largest zero cluster
	local zeros_begin = nil
	local zeros_cnt = 0
	for begin,cnt in pairs(zeros) do
		if cnt > zeros_cnt then
			zeros_begin = begin
			zeros_cnt = cnt
		end
	end

	-- format ipv6 address
	local out = ''
	local i = 1
	while i <= 8 do
		if i == zeros_begin then
			if i > 1 then
				out = out .. ':'
			else
				out = out .. '::'
			end
			i = i + zeros_cnt
		else
			local p = pcs[i]
			local hexdigits = string.format('%x', p)
			out = out .. hexdigits
			if i ~= 8 then
				out = out .. ':'
			end
			i = i + 1
		end
	end

	local mask = self.mask
	if (mask == nil or mask == 128 or withmask == false) and withmask ~= true then
		return out
	else
		return string.format('%s/%d', out, mask)
	end
end

function inet6:__tostring()
	return tostr6(self)
end

function inet6:ipstring()
	return tostr6(self, false)
end

function inet6:cidrstring()
	return tostr6(self, true)
end

function inet6:clone()
	return inet6.new(self.pcs, self.mask)
end

function inet6:__eq(other)
	if self.mask ~= other.mask then
		return false
	end
	local spcs = self.pcs
	local opcs = other.pcs
	for i=1,8 do
		if spcs[i] ~= opcs[i] then
			return false
		end
	end
	return true
end

function inet6:__div(n)
	return inet6.new(self.pcs, n)
end

function inet6:__pow(n)
	return inet6.new(self.pcs, self.mask + n)
end

function inet6:__add(n)
	local new = self:clone()
	local pcs = new.pcs
	pcs[8] = pcs[8] + n
	new:balance(true)
	return new
end

function inet6:__sub(n)
	return self + (n*-1)
end

function inet6:network()
	local netbits = self.mask
	local pcs = self.pcs
	local newpcs = { 0, 0, 0, 0, 0, 0, 0, 0 }
	for i=1,8 do
		if netbits >= i*16 then
			newpcs[i] = pcs[i]
		elseif netbits <= (i-1)*16 then
			break -- the rest is already zero
		else
			local netbitsleft = 16-(netbits-((i-1)*16))
			newpcs[i] = lshift(rshift(pcs[i], netbitsleft), netbitsleft)
		end
	end
	return inet6.new(newpcs, netbits)
end

function inet6:flip()
	-- find twin by flipping the last network bit
	local mask = self.mask
	if mask == 0 then return nil end
	local block = rshift(mask, 4)+1
	local maskbits = band(mask, 0xf)
	local bitno = 16 - maskbits
	if bitno == 16 then
		block = block - 1
		bitno = 0
	end
	local flipbit = lshift(1, bitno)
	local r = self:clone()
	local val = r.pcs[block]
	r.pcs[block] = bxor(r.pcs[block], flipbit)
	--print(mask, block, maskbits, bitno, flipbit, self, r:balance())
	return r
end


function inet6:__mul(n)
	local new = self:clone()
	local mask = new.mask
	local pcs = new.pcs
	local netbitoverflow = mask % 16
	local netbitremainder = (128-mask) % 16
	local p = (mask - netbitoverflow) / 16
	if netbitremainder ~= 0 then
		p = p + 1
	end
	local was_negative = false
	if n < 0 then
		n = n * -1
		was_negative = true
	end
	local shiftet = lshift(n, netbitremainder)
	local high_shift = rshift(shiftet, 16)
	local low_shift = band(shiftet, 0xffff)
	--print(p, netbitoverflow, hex(shiftet), hex(high_shift), hex(low_shift))
	if was_negative then
		high_shift = -high_shift
		low_shift = -low_shift
	end
	if p > 2 then
		pcs[p-1] = pcs[p-1] + high_shift
	end
	pcs[p] = pcs[p] + low_shift
	new:balance()
	-- print(mask % 8)
	return new
end

return inet.new