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authorAsbjørn Sloth Tønnesen <ast@2e8.dk>2019-07-16 19:42:24 +0000
committerAsbjørn Sloth Tønnesen <ast@2e8.dk>2019-07-16 19:42:24 +0000
commit5dbfa921c8df2f5fe518886dc25eb1c44d8c99a7 (patch)
treefb85d23f3ec52a5e9276fb73cbc14e53f3dd8ff5 /lua/inet/core.lua
parenta25b3f729116c5fc9d33233e6636f59770908a1a (diff)
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refactor lua/ directory
Signed-off-by: Asbjørn Sloth Tønnesen <ast@2e8.dk>
Diffstat (limited to 'lua/inet/core.lua')
-rw-r--r--lua/inet/core.lua683
1 files changed, 683 insertions, 0 deletions
diff --git a/lua/inet/core.lua b/lua/inet/core.lua
new file mode 100644
index 0000000..4a5e14f
--- /dev/null
+++ b/lua/inet/core.lua
@@ -0,0 +1,683 @@
+local bit32 = require 'bit32'
+
+local format = string.format
+
+local lshift = bit32.lshift
+local rshift = bit32.rshift
+local band = bit32.band
+local replace = bit32.replace
+local bxor = bit32.bxor
+
+local mt2fam = {}
+
+local inet = {}
+inet.__index = inet
+
+local inet4 = setmetatable({}, inet)
+inet4.__index = inet4
+mt2fam[inet4] = 4
+
+local inet6 = setmetatable({}, inet)
+inet6.__index = inet6
+mt2fam[inet6] = 6
+
+local function get_mt(t)
+ if type(t) ~= 'table' then return nil end
+ return getmetatable(t)
+end
+
+local function is_inet4(t)
+ local mt = get_mt(t)
+ return mt == inet4
+end
+
+local function is_inet6(t)
+ local mt = get_mt(t)
+ return mt == inet6
+end
+
+local function is_inet(t)
+ local mt = get_mt(t)
+ return mt == inet4 or mt == inet6
+end
+
+function inet:__len()
+ local mask = self.mask
+ if mask == nil then return 0 end -- make metatable inspectable
+ return mask
+end
+inet4.__len = inet.__len
+inet6.__len = inet.__len
+
+function inet:family()
+ local mt = assert(getmetatable(self))
+ return assert(mt2fam[mt])
+end
+
+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')
+
+ local ipv4addr
+ 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) / tonumber
+ ipv4addr = 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 = ipv4addr * (netmask + Cc()) * -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 ipv4embed = ipv4addr / function(a,b,c,d)
+ return lshift(a, 8) + b, lshift(c, 8) + d
+ end
+ local last32bits = (ipv4embed + (picol * piece))
+ local full = picol * picol * picol * picol * picol * picol * last32bits
+ local partial = (piece * (colpi^-6))^-1 * colcol * ((picol^-6)*(ipv4embed+piece))^-1
+ local netmask = S('/') * C((digit^-3)) / tonumber
+ local pieces = full + partial
+ ipv6_parser = Ct(pieces) * ((netmask + Cc())^-1) * -1
+ end
+end
+
+local function build_bip(o1, o2, o3, o4)
+ return lshift(o1, 24) + lshift(o2, 16) + lshift(o3, 8) + o4
+end
+
+local function inet4_from_string(ipstr)
+ local o1, o2, o3, o4, mask = ipv4_parser:match(ipstr)
+ if not o1 then return nil, 'parse error' end
+
+ local bip = build_bip(o1, o2, o3, o4)
+ return bip, tonumber(mask)
+end
+
+local function inet4_from_number(bip)
+ return bip
+end
+
+local function inet4_from_table(t)
+ if #t ~= 4 then return nil, 'invalid length' end
+ for i=1,4 do
+ local v = t[i]
+ if type(v) ~= 'number' then return nil, 'invalid number' end
+ if v < 0 or v > 255 then return nil, 'octet out of range' end
+ end
+ return build_bip(t[1], t[2], t[3], t[4])
+end
+
+local inet4_constructors = {
+ string = inet4_from_string,
+ number = inet4_from_number,
+ table = inet4_from_table,
+}
+
+local function inet6_from_string(ipstr)
+ local pcs, netmask = ipv6_parser:match(ipstr)
+ if not pcs then return nil, 'parse error' 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=#pcs,i,-1 do
+ pcs[j+zero_pieces] = pcs[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 ~= nil and netmask > 128 then
+ return nil, 'invalid netmask'
+ end
+ return pcs, netmask
+end
+
+local function inet6_from_table(t)
+ if #t ~= 8 then return nil, 'invalid length' end
+ for i=1,8 do
+ local v = t[i]
+ if type(v) ~= 'number' then return nil, 'invalid number' end
+ if v < 0 or v > 0xffff then return nil, 'octet out of range' end
+ end
+ return { t[1], t[2], t[3], t[4], t[5], t[6], t[7], t[8] }
+end
+
+local inet6_constructors = {
+ string = inet6_from_string,
+ table = inet6_from_table,
+}
+
+local function decide_mask(from_ip, override, high)
+ local newmask = from_ip
+ if override then
+ if type(override) == 'number' and override >= 0 and override <= high then
+ if from_ip ~= nil then
+ return nil, 'multiple masks supplied'
+ end
+ newmask = override
+ else
+ return nil, 'invalid mask'
+ end
+ else
+ if not newmask then
+ newmask = high
+ end
+ end
+ return newmask
+end
+
+local function generic_new(constructors, high, ip, mask)
+ local type_ip = type(ip)
+ local constructor = constructors[type_ip]
+ if not constructor then
+ return nil, 'invalid ip argument'
+ end
+ local iir, ourmask = constructor(ip)
+ if not iir then
+ return nil, ourmask
+ end
+ local outmask, err = decide_mask(ourmask, mask, high)
+ if not outmask then return nil, err end
+
+ return iir, outmask
+end
+
+local function new_inet4(ip, mask)
+ local bip, outmask = generic_new(inet4_constructors, 32, ip, mask)
+ if not bip then return nil, outmask end
+ return setmetatable({
+ bip = bip,
+ mask = outmask,
+ }, inet4)
+end
+
+local function new_inet6(ip, mask)
+ local pcs, outmask = generic_new(inet6_constructors, 128, ip, mask)
+ if not pcs then return nil, outmask end
+
+ local r = setmetatable({
+ pcs = pcs,
+ mask = outmask,
+ }, inet6)
+
+ -- ensure that the result is balanced
+ if not r:is_balanced() then
+ r:balance()
+ return nil, tostring(r)..' unbalanced'
+ end
+
+ return r
+end
+
+local function new_inet(ip, mask)
+ local is_ipv6
+ local type_ip = type(ip)
+ if type_ip == 'string' then
+ is_ipv6 = string.find(ip, ':', 1, true)
+ elseif type_ip == 'number' then
+ is_ipv6 = false
+ elseif is_inet4(ip) then
+ mask = mask or #ip
+ ip = ip.bip
+ is_ipv6 = false
+ elseif is_inet6(ip) then
+ mask = mask or #ip
+ ip = ip.pcs
+ is_ipv6 = true
+ elseif type_ip == 'table' then
+ local n = #ip
+ if n == 8 then
+ is_ipv6 = true
+ elseif n == 4 then
+ is_ipv6 = false
+ else
+ return nil, 'invalid table'
+ end
+ else
+ return nil, 'invalid ip type'
+ end
+
+ if is_ipv6 then
+ return new_inet6(ip, mask)
+ else
+ return new_inet4(ip, mask)
+ end
+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 new_inet4(self.bip + n, self.mask)
+end
+
+function inet4:__sub(n)
+ return new_inet4(self.bip - n, self.mask)
+end
+
+function inet4:__mul(n)
+ local new = self.bip + (n * math.pow(2, 32 - self.mask))
+ return new_inet4(new, self.mask)
+end
+
+function inet4:__div(n)
+ return new_inet4(self.bip, n)
+end
+
+function inet4:__pow(n)
+ return new_inet4(self.bip, self.mask + n)
+end
+
+function inet4:clone()
+ return new_inet4(self.bip, self.mask)
+end
+
+function inet4:contains(other)
+ if self.mask >= other.mask then
+ return false
+ end
+ local mask = self.mask -- make test
+ local self_netbits = replace(self.bip, 0, 0, 32-mask)
+ local other_netbits = replace(other.bip, 0, 0, 32-mask)
+ return self_netbits == other_netbits
+end
+
+function inet4:__lt(other)
+ if self.bip == other.bip then
+ return self.mask < other.mask
+ end
+ return self.bip < other.bip
+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 new_inet4(lshift(rshift(self.bip, hostbits), hostbits), self.mask)
+end
+
+function inet4:netmask()
+ local hostbits = 32 - self.mask
+ return new_inet4(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 new_inet4(bxor(self.bip, flipbit), mask)
+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
+ for i=1,8 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 tohex(n)
+ if n == nil then return nil end
+ return format('%x', n)
+end
+
+local function tostr6(self, withmask, embeddedipv4)
+ -- return human readable
+ local pcs = self.pcs
+ local zeros = {}
+
+ if embeddedipv4 == nil then
+ embeddedipv4 = false -- TODO check if well-known prefix
+ end
+
+ local ipv6pieces = 8
+ if embeddedipv4 then
+ ipv6pieces = 6
+ end
+
+ -- count zero clusters
+ local first_zero = 0
+ local prev_was_zero = false
+ for i=1,ipv6pieces 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 first largest zero cluster
+ local zeros_begin = nil
+ local zeros_cnt = 1
+ for begin=1,ipv6pieces do
+ local cnt = zeros[begin] or 0
+ if cnt > zeros_cnt then
+ zeros_begin = begin
+ zeros_cnt = cnt
+ end
+ end
+
+ -- format ipv6 address
+ local out = ''
+ local i = 1
+ while i <= ipv6pieces 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 = tohex(p)
+ out = out .. hexdigits
+ if i ~= 8 then
+ out = out .. ':'
+ end
+ i = i + 1
+ end
+ end
+
+ if embeddedipv4 then
+ out = out .. new_inet4(lshift(pcs[7], 16) + pcs[8]):ipstring()
+ 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:ipstring4()
+ return tostr6(self, false, true)
+end
+
+function inet6:ipstring6()
+ return tostr6(self, false, false)
+end
+
+function inet6:cidrstring()
+ return tostr6(self, true)
+end
+
+function inet6:clone()
+ return new_inet6(self.pcs, self.mask)
+end
+
+function inet6:contains(other)
+ -- self contains other
+ local mask = self.mask
+
+ if mask > other.mask then
+ return false
+ end
+
+ local snet = self:network()
+ local onet = (other / mask):network()
+
+ return snet == onet
+end
+
+function inet6:__lt(other)
+ -- self < other
+ local spcs = self.pcs
+ local opcs = other.pcs
+
+ for i=1,8 do
+ if spcs[i] < opcs[i] then
+ return true
+ end
+ if spcs[i] > opcs[i] then
+ return false
+ end
+ end
+
+ return self.mask < other.mask
+end
+
+function inet6:__le(other)
+ -- self <= other
+ local spcs = self.pcs
+ local opcs = other.pcs
+ for i=1,8 do
+ if spcs[i] < opcs[i] then
+ return true
+ end
+ if spcs[i] > opcs[i] then
+ return false
+ end
+ end
+
+ return self.mask <= other.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 new_inet6(self.pcs, n)
+end
+
+function inet6:__pow(n)
+ return new_inet6(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 new_inet6(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(val, 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
+ if mask == 0 then return nil, 'unable to perform operation' end
+ 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, tohex(shiftet), tohex(high_shift), tohex(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()
+ return new
+end
+
+local M = {}
+
+M.is_inet4 = is_inet4
+M.is_inet6 = is_inet6
+M.is_inet = is_inet
+M.new_inet = new_inet
+
+return M