diff options
Diffstat (limited to 'lua/inet/core.lua')
| -rw-r--r-- | lua/inet/core.lua | 683 |
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 |