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Diffstat (limited to 'modules/base/luasrc/ip.lua')
| -rw-r--r-- | modules/base/luasrc/ip.lua | 673 |
1 files changed, 673 insertions, 0 deletions
diff --git a/modules/base/luasrc/ip.lua b/modules/base/luasrc/ip.lua new file mode 100644 index 000000000..60ca09013 --- /dev/null +++ b/modules/base/luasrc/ip.lua @@ -0,0 +1,673 @@ +--[[ + +LuCI ip calculation libarary +(c) 2008 Jo-Philipp Wich <xm@leipzig.freifunk.net> +(c) 2008 Steven Barth <steven@midlink.org> + +Licensed under the Apache License, Version 2.0 (the "License"); +you may not use this file except in compliance with the License. +You may obtain a copy of the License at + + http://www.apache.org/licenses/LICENSE-2.0 + +$Id$ + +]]-- + +--- LuCI IP calculation library. +module( "luci.ip", package.seeall ) + +require "nixio" +local bit = nixio.bit +local util = require "luci.util" + +--- Boolean; true if system is little endian +LITTLE_ENDIAN = not util.bigendian() + +--- Boolean; true if system is big endian +BIG_ENDIAN = not LITTLE_ENDIAN + +--- Specifier for IPv4 address family +FAMILY_INET4 = 0x04 + +--- Specifier for IPv6 address family +FAMILY_INET6 = 0x06 + + +local function __bless(x) + return setmetatable( x, { + __index = luci.ip.cidr, + __add = luci.ip.cidr.add, + __sub = luci.ip.cidr.sub, + __lt = luci.ip.cidr.lower, + __eq = luci.ip.cidr.equal, + __le = + function(...) + return luci.ip.cidr.equal(...) or luci.ip.cidr.lower(...) + end + } ) +end + +local function __array16( x, family ) + local list + + if type(x) == "number" then + list = { bit.rshift(x, 16), bit.band(x, 0xFFFF) } + + elseif type(x) == "string" then + if x:find(":") then x = IPv6(x) else x = IPv4(x) end + if x then + assert( x[1] == family, "Can't mix IPv4 and IPv6 addresses" ) + list = { unpack(x[2]) } + end + + elseif type(x) == "table" and type(x[2]) == "table" then + assert( x[1] == family, "Can't mix IPv4 and IPv6 addresses" ) + list = { unpack(x[2]) } + + elseif type(x) == "table" then + list = { unpack(x) } + end + + assert( list, "Invalid operand" ) + + return list +end + +local function __mask16(bits) + return bit.lshift( bit.rshift( 0xFFFF, 16 - bits % 16 ), 16 - bits % 16 ) +end + +local function __not16(bits) + return bit.band( bit.bnot( __mask16(bits) ), 0xFFFF ) +end + +local function __maxlen(family) + return ( family == FAMILY_INET4 ) and 32 or 128 +end + +local function __sublen(family) + return ( family == FAMILY_INET4 ) and 30 or 127 +end + + +--- Convert given short value to network byte order on little endian hosts +-- @param x Unsigned integer value between 0x0000 and 0xFFFF +-- @return Byte-swapped value +-- @see htonl +-- @see ntohs +function htons(x) + if LITTLE_ENDIAN then + return bit.bor( + bit.rshift( x, 8 ), + bit.band( bit.lshift( x, 8 ), 0xFF00 ) + ) + else + return x + end +end + +--- Convert given long value to network byte order on little endian hosts +-- @param x Unsigned integer value between 0x00000000 and 0xFFFFFFFF +-- @return Byte-swapped value +-- @see htons +-- @see ntohl +function htonl(x) + if LITTLE_ENDIAN then + return bit.bor( + bit.lshift( htons( bit.band( x, 0xFFFF ) ), 16 ), + htons( bit.rshift( x, 16 ) ) + ) + else + return x + end +end + +--- Convert given short value to host byte order on little endian hosts +-- @class function +-- @name ntohs +-- @param x Unsigned integer value between 0x0000 and 0xFFFF +-- @return Byte-swapped value +-- @see htonl +-- @see ntohs +ntohs = htons + +--- Convert given short value to host byte order on little endian hosts +-- @class function +-- @name ntohl +-- @param x Unsigned integer value between 0x00000000 and 0xFFFFFFFF +-- @return Byte-swapped value +-- @see htons +-- @see ntohl +ntohl = htonl + + +--- Parse given IPv4 address in dotted quad or CIDR notation. If an optional +-- netmask is given as second argument and the IP address is encoded in CIDR +-- notation then the netmask parameter takes precedence. If neither a CIDR +-- encoded prefix nor a netmask parameter is given, then a prefix length of +-- 32 bit is assumed. +-- @param address IPv4 address in dotted quad or CIDR notation +-- @param netmask IPv4 netmask in dotted quad notation (optional) +-- @return luci.ip.cidr instance or nil if given address was invalid +-- @see IPv6 +-- @see Hex +function IPv4(address, netmask) + address = address or "0.0.0.0/0" + + local obj = __bless({ FAMILY_INET4 }) + + local data = {} + local prefix = address:match("/(.+)") + address = address:gsub("/.+","") + address = address:gsub("^%[(.*)%]$", "%1"):upper():gsub("^::FFFF:", "") + + if netmask then + prefix = obj:prefix(netmask) + elseif prefix then + prefix = tonumber(prefix) + if not prefix or prefix < 0 or prefix > 32 then return nil end + else + prefix = 32 + end + + local b1, b2, b3, b4 = address:match("^(%d+)%.(%d+)%.(%d+)%.(%d+)$") + + b1 = tonumber(b1) + b2 = tonumber(b2) + b3 = tonumber(b3) + b4 = tonumber(b4) + + if b1 and b1 <= 255 and + b2 and b2 <= 255 and + b3 and b3 <= 255 and + b4 and b4 <= 255 and + prefix + then + table.insert(obj, { b1 * 256 + b2, b3 * 256 + b4 }) + table.insert(obj, prefix) + return obj + end +end + +--- Parse given IPv6 address in full, compressed, mixed or CIDR notation. +-- If an optional netmask is given as second argument and the IP address is +-- encoded in CIDR notation then the netmask parameter takes precedence. +-- If neither a CIDR encoded prefix nor a netmask parameter is given, then a +-- prefix length of 128 bit is assumed. +-- @param address IPv6 address in full/compressed/mixed or CIDR notation +-- @param netmask IPv6 netmask in full/compressed/mixed notation (optional) +-- @return luci.ip.cidr instance or nil if given address was invalid +-- @see IPv4 +-- @see Hex +function IPv6(address, netmask) + address = address or "::/0" + + local obj = __bless({ FAMILY_INET6 }) + + local data = {} + local prefix = address:match("/(.+)") + address = address:gsub("/.+","") + address = address:gsub("^%[(.*)%]$", "%1") + + if netmask then + prefix = obj:prefix(netmask) + elseif prefix then + prefix = tonumber(prefix) + if not prefix or prefix < 0 or prefix > 128 then return nil end + else + prefix = 128 + end + + local borderl = address:sub(1, 1) == ":" and 2 or 1 + local borderh, zeroh, chunk, block, i + + if #address > 45 then return nil end + + repeat + borderh = address:find(":", borderl, true) + if not borderh then break end + + block = tonumber(address:sub(borderl, borderh - 1), 16) + if block and block <= 0xFFFF then + data[#data+1] = block + else + if zeroh or borderh - borderl > 1 then return nil end + zeroh = #data + 1 + end + + borderl = borderh + 1 + until #data == 7 + + chunk = address:sub(borderl) + if #chunk > 0 and #chunk <= 4 then + block = tonumber(chunk, 16) + if not block or block > 0xFFFF then return nil end + + data[#data+1] = block + elseif #chunk > 4 then + if #data == 7 or #chunk > 15 then return nil end + borderl = 1 + for i=1, 4 do + borderh = chunk:find(".", borderl, true) + if not borderh and i < 4 then return nil end + borderh = borderh and borderh - 1 + + block = tonumber(chunk:sub(borderl, borderh)) + if not block or block > 255 then return nil end + + if i == 1 or i == 3 then + data[#data+1] = block * 256 + else + data[#data] = data[#data] + block + end + + borderl = borderh and borderh + 2 + end + end + + if zeroh then + if #data == 8 then return nil end + while #data < 8 do + table.insert(data, zeroh, 0) + end + end + + if #data == 8 and prefix then + table.insert(obj, data) + table.insert(obj, prefix) + return obj + end +end + +--- Transform given hex-encoded value to luci.ip.cidr instance of specified +-- address family. +-- @param hex String containing hex encoded value +-- @param prefix Prefix length of CIDR instance (optional, default is 32/128) +-- @param family Address family, either luci.ip.FAMILY_INET4 or FAMILY_INET6 +-- @param swap Bool indicating whether to swap byteorder on low endian host +-- @return luci.ip.cidr instance or nil if given value was invalid +-- @see IPv4 +-- @see IPv6 +function Hex( hex, prefix, family, swap ) + family = ( family ~= nil ) and family or FAMILY_INET4 + swap = ( swap == nil ) and true or swap + prefix = prefix or __maxlen(family) + + local len = __maxlen(family) + local tmp = "" + local data = { } + local i + + for i = 1, (len/4) - #hex do tmp = tmp .. '0' end + + if swap and LITTLE_ENDIAN then + for i = #hex, 1, -2 do tmp = tmp .. hex:sub( i - 1, i ) end + else + tmp = tmp .. hex + end + + hex = tmp + + for i = 1, ( len / 4 ), 4 do + local n = tonumber( hex:sub( i, i+3 ), 16 ) + if n then + data[#data+1] = n + else + return nil + end + end + + return __bless({ family, data, prefix }) +end + + +--- LuCI IP Library / CIDR instances +-- @class module +-- @cstyle instance +-- @name luci.ip.cidr +cidr = util.class() + +--- Test whether the instance is a IPv4 address. +-- @return Boolean indicating a IPv4 address type +-- @see cidr.is6 +function cidr.is4( self ) + return self[1] == FAMILY_INET4 +end + +--- Test whether this instance is an IPv4 RFC1918 private address +-- @return Boolean indicating whether this instance is an RFC1918 address +function cidr.is4rfc1918( self ) + if self[1] == FAMILY_INET4 then + return ((self[2][1] >= 0x0A00) and (self[2][1] <= 0x0AFF)) or + ((self[2][1] >= 0xAC10) and (self[2][1] <= 0xAC1F)) or + (self[2][1] == 0xC0A8) + end + return false +end + +--- Test whether this instance is an IPv4 link-local address (Zeroconf) +-- @return Boolean indicating whether this instance is IPv4 link-local +function cidr.is4linklocal( self ) + if self[1] == FAMILY_INET4 then + return (self[2][1] == 0xA9FE) + end + return false +end + +--- Test whether the instance is a IPv6 address. +-- @return Boolean indicating a IPv6 address type +-- @see cidr.is4 +function cidr.is6( self ) + return self[1] == FAMILY_INET6 +end + +--- Test whether this instance is an IPv6 link-local address +-- @return Boolean indicating whether this instance is IPv6 link-local +function cidr.is6linklocal( self ) + if self[1] == FAMILY_INET6 then + return (self[2][1] >= 0xFE80) and (self[2][1] <= 0xFEBF) + end + return false +end + +--- Return a corresponding string representation of the instance. +-- If the prefix length is lower then the maximum possible prefix length for the +-- corresponding address type then the address is returned in CIDR notation, +-- otherwise the prefix will be left out. +function cidr.string( self ) + local str + if self:is4() then + str = string.format( + "%d.%d.%d.%d", + bit.rshift(self[2][1], 8), bit.band(self[2][1], 0xFF), + bit.rshift(self[2][2], 8), bit.band(self[2][2], 0xFF) + ) + if self[3] < 32 then + str = str .. "/" .. self[3] + end + elseif self:is6() then + str = string.format( "%X:%X:%X:%X:%X:%X:%X:%X", unpack(self[2]) ) + if self[3] < 128 then + str = str .. "/" .. self[3] + end + end + return str +end + +--- Test whether the value of the instance is lower then the given address. +-- This function will throw an exception if the given address has a different +-- family than this instance. +-- @param addr A luci.ip.cidr instance to compare against +-- @return Boolean indicating whether this instance is lower +-- @see cidr.higher +-- @see cidr.equal +function cidr.lower( self, addr ) + assert( self[1] == addr[1], "Can't compare IPv4 and IPv6 addresses" ) + local i + for i = 1, #self[2] do + if self[2][i] ~= addr[2][i] then + return self[2][i] < addr[2][i] + end + end + return false +end + +--- Test whether the value of the instance is higher then the given address. +-- This function will throw an exception if the given address has a different +-- family than this instance. +-- @param addr A luci.ip.cidr instance to compare against +-- @return Boolean indicating whether this instance is higher +-- @see cidr.lower +-- @see cidr.equal +function cidr.higher( self, addr ) + assert( self[1] == addr[1], "Can't compare IPv4 and IPv6 addresses" ) + local i + for i = 1, #self[2] do + if self[2][i] ~= addr[2][i] then + return self[2][i] > addr[2][i] + end + end + return false +end + +--- Test whether the value of the instance is equal to the given address. +-- This function will throw an exception if the given address is a different +-- family than this instance. +-- @param addr A luci.ip.cidr instance to compare against +-- @return Boolean indicating whether this instance is equal +-- @see cidr.lower +-- @see cidr.higher +function cidr.equal( self, addr ) + assert( self[1] == addr[1], "Can't compare IPv4 and IPv6 addresses" ) + local i + for i = 1, #self[2] do + if self[2][i] ~= addr[2][i] then + return false + end + end + return true +end + +--- Return the prefix length of this CIDR instance. +-- @param mask Override instance prefix with given netmask (optional) +-- @return Prefix length in bit +function cidr.prefix( self, mask ) + local prefix = self[3] + + if mask then + prefix = 0 + + local stop = false + local obj = type(mask) ~= "table" + and ( self:is4() and IPv4(mask) or IPv6(mask) ) or mask + + if not obj then return nil end + + local _, word + for _, word in ipairs(obj[2]) do + if word == 0xFFFF then + prefix = prefix + 16 + else + local bitmask = bit.lshift(1, 15) + while bit.band(word, bitmask) == bitmask do + prefix = prefix + 1 + bitmask = bit.lshift(1, 15 - (prefix % 16)) + end + + break + end + end + end + + return prefix +end + +--- Return a corresponding CIDR representing the network address of this +-- instance. +-- @param bits Override prefix length of this instance (optional) +-- @return CIDR instance containing the network address +-- @see cidr.host +-- @see cidr.broadcast +-- @see cidr.mask +function cidr.network( self, bits ) + local data = { } + bits = bits or self[3] + + local i + for i = 1, math.floor( bits / 16 ) do + data[#data+1] = self[2][i] + end + + if #data < #self[2] then + data[#data+1] = bit.band( self[2][1+#data], __mask16(bits) ) + + for i = #data + 1, #self[2] do + data[#data+1] = 0 + end + end + + return __bless({ self[1], data, __maxlen(self[1]) }) +end + +--- Return a corresponding CIDR representing the host address of this +-- instance. This is intended to extract the host address from larger subnet. +-- @return CIDR instance containing the network address +-- @see cidr.network +-- @see cidr.broadcast +-- @see cidr.mask +function cidr.host( self ) + return __bless({ self[1], self[2], __maxlen(self[1]) }) +end + +--- Return a corresponding CIDR representing the netmask of this instance. +-- @param bits Override prefix length of this instance (optional) +-- @return CIDR instance containing the netmask +-- @see cidr.network +-- @see cidr.host +-- @see cidr.broadcast +function cidr.mask( self, bits ) + local data = { } + bits = bits or self[3] + + for i = 1, math.floor( bits / 16 ) do + data[#data+1] = 0xFFFF + end + + if #data < #self[2] then + data[#data+1] = __mask16(bits) + + for i = #data + 1, #self[2] do + data[#data+1] = 0 + end + end + + return __bless({ self[1], data, __maxlen(self[1]) }) +end + +--- Return CIDR containing the broadcast address of this instance. +-- @return CIDR instance containing the netmask, always nil for IPv6 +-- @see cidr.network +-- @see cidr.host +-- @see cidr.mask +function cidr.broadcast( self ) + -- IPv6 has no broadcast addresses (XXX: assert() instead?) + if self[1] == FAMILY_INET4 then + local data = { unpack(self[2]) } + local offset = math.floor( self[3] / 16 ) + 1 + + if offset <= #data then + data[offset] = bit.bor( data[offset], __not16(self[3]) ) + for i = offset + 1, #data do data[i] = 0xFFFF end + + return __bless({ self[1], data, __maxlen(self[1]) }) + end + end +end + +--- Test whether this instance fully contains the given CIDR instance. +-- @param addr CIDR instance to test against +-- @return Boolean indicating whether this instance contains the given CIDR +function cidr.contains( self, addr ) + assert( self[1] == addr[1], "Can't compare IPv4 and IPv6 addresses" ) + + if self:prefix() <= addr:prefix() then + return self:network() == addr:network(self:prefix()) + end + + return false +end + +--- Add specified amount of hosts to this instance. +-- @param amount Number of hosts to add to this instance +-- @param inplace Boolen indicating whether to alter values inplace (optional) +-- @return CIDR representing the new address or nil on overflow error +-- @see cidr.sub +function cidr.add( self, amount, inplace ) + local pos + local data = { unpack(self[2]) } + local shorts = __array16( amount, self[1] ) + + for pos = #data, 1, -1 do + local add = ( #shorts > 0 ) and table.remove( shorts, #shorts ) or 0 + if ( data[pos] + add ) > 0xFFFF then + data[pos] = ( data[pos] + add ) % 0xFFFF + if pos > 1 then + data[pos-1] = data[pos-1] + ( add - data[pos] ) + else + return nil + end + else + data[pos] = data[pos] + add + end + end + + if inplace then + self[2] = data + return self + else + return __bless({ self[1], data, self[3] }) + end +end + +--- Substract specified amount of hosts from this instance. +-- @param amount Number of hosts to substract from this instance +-- @param inplace Boolen indicating whether to alter values inplace (optional) +-- @return CIDR representing the new address or nil on underflow error +-- @see cidr.add +function cidr.sub( self, amount, inplace ) + local pos + local data = { unpack(self[2]) } + local shorts = __array16( amount, self[1] ) + + for pos = #data, 1, -1 do + local sub = ( #shorts > 0 ) and table.remove( shorts, #shorts ) or 0 + if ( data[pos] - sub ) < 0 then + data[pos] = ( sub - data[pos] ) % 0xFFFF + if pos > 1 then + data[pos-1] = data[pos-1] - ( sub + data[pos] ) + else + return nil + end + else + data[pos] = data[pos] - sub + end + end + + if inplace then + self[2] = data + return self + else + return __bless({ self[1], data, self[3] }) + end +end + +--- Return CIDR containing the lowest available host address within this subnet. +-- @return CIDR containing the host address, nil if subnet is too small +-- @see cidr.maxhost +function cidr.minhost( self ) + if self[3] <= __sublen(self[1]) then + -- 1st is Network Address in IPv4 and Subnet-Router Anycast Adresse in IPv6 + return self:network():add(1, true) + end +end + +--- Return CIDR containing the highest available host address within the subnet. +-- @return CIDR containing the host address, nil if subnet is too small +-- @see cidr.minhost +function cidr.maxhost( self ) + if self[3] <= __sublen(self[1]) then + local i + local data = { unpack(self[2]) } + local offset = math.floor( self[3] / 16 ) + 1 + + data[offset] = bit.bor( data[offset], __not16(self[3]) ) + for i = offset + 1, #data do data[i] = 0xFFFF end + data = __bless({ self[1], data, __maxlen(self[1]) }) + + -- Last address in reserved for Broadcast Address in IPv4 + if data[1] == FAMILY_INET4 then data:sub(1, true) end + + return data + end +end |