--- Utility functions for manipulating and comparing IP addresses. -- @copyright Same as Nmap--See http://nmap.org/book/man-legal.html local type = type local table = table local string = string local ipairs = ipairs local tonumber = tonumber local stdnse = require "stdnse" local bit = require "bit" module ( "ipOps" ) --- -- Checks to see if the supplied IP address is part of a non-routable -- address space. -- -- The non-Internet-routable address spaces known to this function are -- * IPv4 Loopback (RFC3330) -- * IPv4 Private Use (RFC1918) -- * IPv4 Link Local (RFC3330) -- * IPv6 Unspecified and Loopback (RFC3513) -- * IPv6 Unique Local Unicast (RFC4193) -- * IPv6 Link Local Unicast (RFC4291) -- @param ip String representing an IPv4 or IPv6 address. Shortened notation -- is permitted. -- @usage -- local is_private = ipOps.isPrivate( "192.168.1.1" ) -- @return True or false (or nil in case of an error). -- @return String error message in case of an error. isPrivate = function( ip ) local err ip, err = expand_ip( ip ) if err then return nil, err end local ipv4_private = { "10/8", "127/8", "169.254/16", "172.15/12", "192.168/16" } local ipv6_private = { "::/127", "FC00::/7", "FE80::/10" } local t, is_private = {} if ip:match( ":" ) then t = ipv6_private else t = ipv4_private end for _, range in ipairs( t ) do is_private, err = ip_in_range( ip, range ) -- return as soon as is_private is true or err if is_private then return true end if err then return nil, err end end return false end --- -- Converts the supplied IPv4 address into a DWORD value. -- -- For example, the address a.b.c.d becomes (((a*256+b)*256+c)*256+d). -- -- Note: IPv6 addresses are not supported. Currently, numbers in NSE are -- limited to 10^14, and consequently not all IPv6 addresses can be -- represented. -- @param ip String representing an IPv4 address. Shortened notation is -- permitted. -- @usage -- local dword = ipOps.todword( "73.150.2.210" ) -- @return Number corresponding to the supplied IP address (or nil -- in case of an error). -- @return String error message in case of an error. todword = function( ip ) if type( ip ) ~= "string" or ip:match( ":" ) then return nil, "Error in ipOps.todword: Expected IPv4 address." end local n, ret, err = {} n, err = get_parts_as_number( ip ) if err then return nil, err end ret = (((n[1]*256+n[2]))*256+n[3])*256+n[4] return ret end --- -- Converts the supplied IPv4 address from a DWORD value into a dotted string. -- -- For example, the address (((a*256+b)*256+c)*256+d) becomes a.b.c.d. -- --@param ip DWORD representing an IPv4 address. --@return The string representing the address. fromdword = function( ip ) if type( ip ) ~= "number" then stdnse.print_debug(1, "Error in ipOps.todword: Expected IPv4 address.") return nil end local n1 = bit.band(bit.rshift(ip, 0), 0x000000FF) local n2 = bit.band(bit.rshift(ip, 8), 0x000000FF) local n3 = bit.band(bit.rshift(ip, 16), 0x000000FF) local n4 = bit.band(bit.rshift(ip, 24), 0x000000FF) return string.format("%d.%d.%d.%d", n1, n2, n3, n4) end --- -- Separates the supplied IP address into its constituent parts and -- returns them as a table of numbers. -- -- For example, the address 139.104.32.123 becomes { 139, 104, 32, 123 }. -- @usage -- local a, b, c, d; -- local t, err = ipOps.get_parts_as_number( "139.104.32.123" ) -- if t then a, b, c, d = unpack( t ) end -- @param ip String representing an IPv4 or IPv6 address. Shortened notation -- is permitted. -- @return Array of numbers for each part of the supplied IP address (or -- nil in case of an error). -- @return String error message in case of an error. get_parts_as_number = function( ip ) local err ip, err = expand_ip( ip ) if err then return nil, err end local pattern, base if ip:match( ":" ) then pattern = "%x+" base = 16 else pattern = "%d+" base = 10 end local t = {} for part in string.gmatch(ip, pattern) do t[#t+1] = tonumber( part, base ) end return t end --- -- Compares two IP addresses (from the same address family). -- @param left String representing an IPv4 or IPv6 address. Shortened -- notation is permitted. -- @param op A comparison operator which may be one of the following -- strings: "eq", "ge", "le", -- "gt" or "lt" (respectively ==, >=, <=, >, <). -- @param right String representing an IPv4 or IPv6 address. Shortened -- notation is permitted. -- @usage -- if ipOps.compare_ip( "2001::DEAD:0:0:0", "eq", "2001:0:0:0:DEAD::" ) then -- ... -- end -- @return True or false (or nil in case of an error). -- @return String error message in case of an error. compare_ip = function( left, op, right ) if type( left ) ~= "string" or type( right ) ~= "string" then return nil, "Error in ipOps.compare_ip: Expected IP address as a string." end if ( left:match( ":" ) and not right:match( ":" ) ) or ( not left:match( ":" ) and right:match( ":" ) ) then return nil, "Error in ipOps.compare_ip: IP addresses must be from the same address family." end if op == "lt" or op == "le" then left, right = right, left elseif op ~= "eq" and op ~= "ge" and op ~= "gt" then return nil, "Error in ipOps.compare_ip: Invalid Operator." end local err ={} left, err[#err+1] = ip_to_bin( left ) right, err[#err+1] = ip_to_bin( right ) if #err > 0 then return nil, table.concat( err, " " ) end if string.len( left ) ~= string.len( right ) then -- shouldn't happen... return nil, "Error in ipOps.compare_ip: Binary IP addresses were of different lengths." end -- equal? if ( op == "eq" or op == "le" or op == "ge" ) and left == right then return true elseif op == "eq" then return false end -- starting from the leftmost bit, subtract the bit in right from the bit in left local compare for i = 1, string.len( left ), 1 do compare = tonumber( string.sub( left, i, i ) ) - tonumber( string.sub( right, i, i ) ) if compare == 1 then return true elseif compare == -1 then return false end end return false end --- -- Checks whether the supplied IP address is within the supplied range of IP -- addresses. -- -- The address and the range must both belong to the same address family. -- @param ip String representing an IPv4 or IPv6 address. Shortened -- notation is permitted. -- @param range String representing a range of IPv4 or IPv6 addresses in -- first-last or CIDR notation (e.g. -- "192.168.1.1 - 192.168.255.255" or -- "2001:0A00::/23"). -- @usage -- if ipOps.ip_in_range( "192.168.1.1", "192/8" ) then ... end -- @return True or false (or nil in case of an error). -- @return String error message in case of an error. ip_in_range = function( ip, range ) local first, last, err = get_ips_from_range( range ) if err then return nil, err end ip, err = expand_ip( ip ) if err then return nil, err end if ( ip:match( ":" ) and not first:match( ":" ) ) or ( not ip:match( ":" ) and first:match( ":" ) ) then return nil, "Error in ipOps.ip_in_range: IP address is of a different address family to Range." end err = {} local ip_ge_first, ip_le_last ip_ge_first, err[#err+1] = compare_ip( ip, "ge", first ) ip_le_last, err[#err+1] = compare_ip( ip, "le", last ) if #err > 0 then return nil, table.concat( err, " " ) end if ip_ge_first and ip_le_last then return true else return false end end --- -- Expands an IP address supplied in shortened notation. -- Serves also to check the well-formedness of an IP address. -- -- Note: IPv4in6 notated addresses will be returned in pure IPv6 notation unless -- the IPv4 portion is shortened and does not contain a dot, in which case the -- address will be treated as IPv6. -- @param ip String representing an IPv4 or IPv6 address in shortened or full notation. -- @usage -- local ip = ipOps.expand_ip( "2001::" ) -- @return String representing a fully expanded IPv4 or IPv6 address (or -- nil in case of an error). -- @return String error message in case of an error. expand_ip = function( ip ) local err if type( ip ) ~= "string" or ip == "" then return nil, "Error in ipOps.expand_ip: Expected IP address as a string." end local err4 = "Error in ipOps.expand_ip: An address assumed to be IPv4 was malformed." if not ip:match( ":" ) then -- ipv4: missing octets should be "0" appended if ip:match( "[^\.0-9]" ) then return nil, err4 end local octets = {} for octet in string.gmatch( ip, "%d+" ) do if tonumber( octet, 10 ) > 255 then return nil, err4 end octets[#octets+1] = octet end if #octets > 4 then return nil, err4 end while #octets < 4 do octets[#octets+1] = "0" end return ( table.concat( octets, "." ) ) end if ip:match( "[^\.:%x]" ) then return nil, ( err4:gsub( "IPv4", "IPv6" ) ) end -- preserve :: ip = string.gsub(ip, "::", ":z:") -- get a table of each hexadectet local hexadectets = {} for hdt in string.gmatch( ip, "[\.z%x]+" ) do hexadectets[#hexadectets+1] = hdt end -- deal with IPv4in6 (last hexadectet only) local t = {} if hexadectets[#hexadectets]:match( "[\.]+" ) then hexadectets[#hexadectets], err = expand_ip( hexadectets[#hexadectets] ) if err then return nil, ( err:gsub( "IPv4", "IPv4in6" ) ) end t = stdnse.strsplit( "[\.]+", hexadectets[#hexadectets] ) for i, v in ipairs( t ) do t[i] = tonumber( v, 10 ) end hexadectets[#hexadectets] = stdnse.tohex( 256*t[1]+t[2] ) hexadectets[#hexadectets+1] = stdnse.tohex( 256*t[3]+t[4] ) end -- deal with :: and check for invalid address local z_done = false for index, value in ipairs( hexadectets ) do if value:match( "[\.]+" ) then -- shouldn't have dots at this point return nil, ( err4:gsub( "IPv4", "IPv6" ) ) elseif value == "z" and z_done then -- can't have more than one :: return nil, ( err4:gsub( "IPv4", "IPv6" ) ) elseif value == "z" and not z_done then z_done = true hexadectets[index] = "0" local bound = 8 - #hexadectets for i = 1, bound, 1 do table.insert( hexadectets, index+i, "0" ) end elseif tonumber( value, 16 ) > 65535 then -- more than FFFF! return nil, ( err4:gsub( "IPv4", "IPv6" ) ) end end -- make sure we have exactly 8 hexadectets if #hexadectets > 8 then return nil, ( err4:gsub( "IPv4", "IPv6" ) ) end while #hexadectets < 8 do hexadectets[#hexadectets+1] = "0" end return ( table.concat( hexadectets, ":" ) ) end --- -- Returns the first and last IP addresses in the supplied range of addresses. -- @param range String representing a range of IPv4 or IPv6 addresses in either -- CIDR or first-last notation. -- @usage -- first, last = ipOps.get_ips_from_range( "192.168.0.0/16" ) -- @return String representing the first address in the supplied range (or -- nil in case of an error). -- @return String representing the last address in the supplied range (or -- nil in case of an error). -- @return String error message in case of an error. get_ips_from_range = function( range ) if type( range ) ~= "string" then return nil, nil, "Error in ipOps.get_ips_from_range: Expected a range as a string." end local first, last, prefix if range:match( "/" ) then first, prefix = range:match( "([%x%d:\.]+)/(%d+)" ) elseif range:match( "-" ) then first, last = range:match( "([%x%d:\.]+)%s*\-%s*([%x%d:\.]+)" ) end local err = {} if first and ( last or prefix ) then first, err[#err+1] = expand_ip( first ) else return nil, nil, "Error in ipOps.get_ips_from_range: The range supplied could not be interpreted." end if last then last, err[#err+1] = expand_ip( last ) elseif first and prefix then last, err[#err+1] = get_last_ip( first, prefix ) end if first and last then if ( first:match( ":" ) and not last:match( ":" ) ) or ( not first:match( ":" ) and last:match( ":" ) ) then return nil, nil, "Error in ipOps.get_ips_from_range: First IP address is of a different address family to last IP address." end return first, last else return nil, nil, table.concat( err, " " ) end end --- -- Calculates the last IP address of a range of addresses given an IP address in -- the range and prefix length for that range. -- @param ip String representing an IPv4 or IPv6 address. Shortened -- notation is permitted. -- @param prefix Number or a string representing a decimal number corresponding -- to a prefix length. -- @usage -- last = ipOps.get_last_ip( "192.0.0.0", 26 ) -- @return String representing the last IP address of the range denoted -- by the supplied parameters (or nil in case of an error). -- @return String error message in case of an error. get_last_ip = function( ip, prefix ) local first, err = ip_to_bin( ip ) if err then return nil, err end prefix = tonumber( prefix ) if not prefix or ( prefix < 0 ) or ( prefix > string.len( first ) ) then return nil, "Error in ipOps.get_last_ip: Invalid prefix length." end local hostbits = string.sub( first, prefix + 1 ) hostbits = string.gsub( hostbits, "0", "1" ) local last = string.sub( first, 1, prefix ) .. hostbits last, err = bin_to_ip( last ) if err then return nil, err end return last end --- -- Converts an IP address into a string representing the address as binary -- digits. -- @param ip String representing an IPv4 or IPv6 address. Shortened notation -- is permitted. -- @usage -- bit_string = ipOps.ip_to_bin( "2001::" ) -- @return String representing the supplied IP address as 32 or 128 binary -- digits (or nil in case of an error). -- @return String error message in case of an error. ip_to_bin = function( ip ) local err ip, err = expand_ip( ip ) if err then return nil, err end local t, mask = {} if not ip:match( ":" ) then -- ipv4 string for octet in string.gmatch( ip, "%d+" ) do t[#t+1] = stdnse.tohex( tonumber(octet) ) end mask = "00" else -- ipv6 string for hdt in string.gmatch( ip, "%x+" ) do t[#t+1] = hdt end mask = "0000" end -- padding for i, v in ipairs( t ) do t[i] = mask:sub( 1, string.len( mask ) - string.len( v ) ) .. v end return hex_to_bin( table.concat( t ) ) end --- -- Converts a string of binary digits into an IP address. -- @param binstring String representing an IP address as 32 or 128 binary -- digits. -- @usage -- ip = ipOps.bin_to_ip( "01111111000000000000000000000001" ) -- @return String representing an IP address (or nil in -- case of an error). -- @return String error message in case of an error. bin_to_ip = function( binstring ) if type( binstring ) ~= "string" or binstring:match( "[^01]+" ) then return nil, "Error in ipOps.bin_to_ip: Expected string of binary digits." end local af if string.len( binstring ) == 32 then af = 4 elseif string.len( binstring ) == 128 then af = 6 else return nil, "Error in ipOps.bin_to_ip: Expected exactly 32 or 128 binary digits." end local t = {} if af == 6 then local pattern = string.rep( "[01]", 16 ) for chunk in string.gmatch( binstring, pattern ) do t[#t+1] = stdnse.tohex( tonumber( chunk, 2 ) ) end return table.concat( t, ":" ) end if af == 4 then local pattern = string.rep( "[01]", 8 ) for chunk in string.gmatch( binstring, pattern ) do t[#t+1] = tonumber( chunk, 2 ) .. "" end return table.concat( t, "." ) end end --- -- Converts a string of hexadecimal digits into the corresponding string of -- binary digits. -- -- Each hex digit results in four bits. This function is really just a wrapper -- around stdnse.tobinary. -- @param hex String representing a hexadecimal number. -- @usage -- bin_string = ipOps.hex_to_bin( "F00D" ) -- @return String representing the supplied number in binary digits (or -- nil in case of an error). -- @return String error message in case of an error. hex_to_bin = function( hex ) if type( hex ) ~= "string" or hex == "" or hex:match( "[^%x]+" ) then return nil, "Error in ipOps.hex_to_bin: Expected string representing a hexadecimal number." end local t, mask, binchar = {}, "0000" for hexchar in string.gmatch( hex, "%x" ) do binchar = stdnse.tobinary( tonumber( hexchar, 16 ) ) t[#t+1] = mask:sub( 1, string.len( mask ) - string.len( binchar ) ) .. binchar end return table.concat( t ) end