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-rw-r--r--nselib/dhcp6.lua661
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diff --git a/nselib/dhcp6.lua b/nselib/dhcp6.lua
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+---
+-- Minimalistic DHCP6 (Dynamic Host Configuration Protocol for IPv6)
+-- implementation supporting basic DHCP6 Solicit requests The library
+-- is structured around the following classes:
+-- * DHCP6.Option - DHCP6 options encoders (for requests) and decoders
+-- (for responses)
+-- * DHCP6.Request - DHCP6 request encoder and decoder
+-- * DHCP6.Response - DHCP6 response encoder and decoder
+-- * Helper - The helper class, primary script interface
+--
+-- The following sample code sends a DHCP6 Solicit request and returns a
+-- response suitable for script output:
+-- <code>
+-- local helper = DHCP6.Helper:new("eth0")
+-- local status, response = helper:solicit()
+-- if ( status ) then
+-- return stdnse.format_output(true, response)
+-- end
+-- </code>
+--
+-- @author Patrik Karlsson <patrik@cqure.net>
+--
+
+local datetime = require "datetime"
+local ipOps = require "ipOps"
+local math = require "math"
+local nmap = require "nmap"
+local os = require "os"
+local stdnse = require "stdnse"
+local string = require "string"
+local table = require "table"
+_ENV = stdnse.module("dhcp6", stdnse.seeall)
+
+DHCP6 = {}
+
+-- DHCP6 request and response types
+DHCP6.Type = {
+ SOLICIT = 1,
+ ADVERTISE = 2,
+ REQUEST = 3,
+}
+
+-- DHCP6 type as string
+DHCP6.TypeStr = {
+ [DHCP6.Type.SOLICIT] = "Solicit",
+ [DHCP6.Type.ADVERTISE] = "Advertise",
+ [DHCP6.Type.REQUEST] = "Request",
+}
+
+-- DHCP6 option types
+DHCP6.OptionTypes = {
+ OPTION_CLIENTID = 0x01,
+ OPTION_SERVERID = 0x02,
+ OPTION_IA_NA = 0x03,
+ OPTION_IAADDR = 0x05,
+ OPTION_ELAPSED_TIME = 0x08,
+ OPTION_STATUS_CODE = 0x0d,
+ OPTION_DNS_SERVERS = 0x17,
+ OPTION_DOMAIN_LIST = 0x18,
+ OPTION_IA_PD = 0x19,
+ OPTION_SNTP_SERVERS = 0x1f,
+ OPTION_CLIENT_FQDN = 0x27,
+}
+
+local DHCP6_EPOCH = os.time({year=2000, day=1, month=1, hour=0, min=0, sec=0})
+-- DHCP6 options
+DHCP6.Option = {
+
+ [DHCP6.OptionTypes.OPTION_ELAPSED_TIME] = {
+
+ -- Create a new class instance
+ -- @param time in ms since last request
+ -- @return o new instance of class
+ new = function(self, time)
+ local o = {
+ type = DHCP6.OptionTypes.OPTION_ELAPSED_TIME,
+ time = time,
+ -- in case no time was created, we need this to be able to
+ -- calculate time since instantiation
+ created = os.time(),
+ }
+ setmetatable(o, self)
+ self.__index = self
+ return o
+ end,
+
+ -- Converts option to a string
+ -- @return str string containing the class instance as string
+ __tostring = function(self)
+ local data
+ if ( self.time ) then
+ data = string.pack(">I2", self.time)
+ else
+ data = string.pack(">I2", (os.time() - self.created) * 1000)
+ end
+ return string.pack(">I2s2", self.type, data)
+ end,
+
+ },
+
+ [DHCP6.OptionTypes.OPTION_CLIENTID] = {
+
+ -- Create a new class instance
+ -- @param mac string containing the mac address
+ -- @param duid number the duid of the client
+ -- @param hwtype number the hwtype of the client
+ -- @param time number time since 2000-01-01 00:00:00
+ -- @return o new instance of class
+ new = function(self, mac, duid, hwtype, time)
+ local o = {
+ type = DHCP6.OptionTypes.OPTION_CLIENTID,
+ duid = duid or 1,
+ hwtype = hwtype or 1,
+ time = time or os.time() - DHCP6_EPOCH,
+ mac = mac,
+ }
+ setmetatable(o, self)
+ self.__index = self
+ return o
+ end,
+
+ -- Parse the data string and create an instance of the class
+ -- @param data string containing the data as received over the socket
+ -- @return opt new instance of option
+ parse = function(data)
+ local opt = DHCP6.Option[DHCP6.OptionTypes.OPTION_CLIENTID]:new()
+ local pos
+ opt.duid, pos = string.unpack(">I2", data, pos)
+ if ( 1 ~= opt.duid ) then
+ stdnse.debug1("Unexpected DUID type (%d)", opt.duid)
+ return
+ end
+ opt.hwtype, opt.time = string.unpack(">I2I4", data, pos)
+ opt.mac = data:sub(pos)
+ opt.time = opt.time + DHCP6_EPOCH
+ return opt
+ end,
+
+ -- Converts option to a string
+ -- @return str string containing the class instance as string
+ __tostring = function(self)
+ local data = string.pack(">I2I2I4", self.duid, self.hwtype, self.time) .. self.mac
+ return string.pack(">I2s2", self.type, data)
+ end,
+ },
+
+ [DHCP6.OptionTypes.OPTION_SERVERID] = {
+ -- Create a new class instance
+ -- @param mac string containing the mac address
+ -- @param duid number the duid of the client
+ -- @param hwtype number the hwtype of the client
+ -- @param time number time since 2000-01-01 00:00:00
+ -- @return o new instance of class
+ new = function(...) return DHCP6.Option[DHCP6.OptionTypes.OPTION_CLIENTID].new(...) end,
+
+ -- Parse the data string and create an instance of the class
+ -- @param data string containing the data as received over the socket
+ -- @return opt new instance of option
+ parse = function(...) return DHCP6.Option[DHCP6.OptionTypes.OPTION_CLIENTID].parse(...) end,
+
+ -- Converts option to a string
+ -- @return str string containing the class instance as string
+ __tostring = function(...) return DHCP6.Option[DHCP6.OptionTypes.OPTION_CLIENTID].__tostring(...) end,
+ },
+
+ [DHCP6.OptionTypes.OPTION_STATUS_CODE] = {
+
+ -- Create a new class instance
+ -- @param code number containing the error code
+ -- @param msg string containing the error message
+ -- @return o new instance of class
+ new = function(self, code, msg)
+ local o = {
+ type = DHCP6.OptionTypes.OPTION_STATUS_CODE,
+ code = code,
+ msg = msg,
+ }
+ setmetatable(o, self)
+ self.__index = self
+ return o
+ end,
+
+ -- Parse the data string and create an instance of the class
+ -- @param data string containing the data as received over the socket
+ -- @return opt new instance of option
+ parse = function(data)
+ local opt = DHCP6.Option[DHCP6.OptionTypes.OPTION_STATUS_CODE]:new()
+
+ local pos
+ opt.code, pos = string.unpack(">I2", data)
+ opt.msg = data:sub(pos)
+
+ return opt
+ end,
+
+ },
+
+ [DHCP6.OptionTypes.OPTION_DNS_SERVERS] = {
+
+ -- Create a new class instance
+ -- @param servers table containing DNS servers
+ -- @return o new instance of class
+ new = function(self, servers)
+ local o = {
+ type = DHCP6.OptionTypes.OPTION_DNS_SERVERS,
+ servers = servers or {},
+ }
+ setmetatable(o, self)
+ self.__index = self
+ return o
+ end,
+
+ -- Parse the data string and create an instance of the class
+ -- @param data string containing the data as received over the socket
+ -- @return opt new instance of option
+ parse = function(data)
+ local opt = DHCP6.Option[DHCP6.OptionTypes.OPTION_DNS_SERVERS]:new()
+ local pos, count = 1, #data/16
+
+ for i=1,count do
+ local srv
+ srv, pos = string.unpack(">c16", data, pos)
+ table.insert(opt.servers, srv)
+ end
+ return opt
+ end,
+
+ -- Converts option to a string
+ -- @return str string containing the class instance as string
+ __tostring = function(self)
+ local data = {}
+ for _, ipv6 in ipairs(self.servers) do
+ data[#data+1] = ipOps.ip_to_str(ipv6)
+ end
+ data = table.concat(data)
+ return string.pack(">I2s2", self.type, data)
+ end
+ },
+
+ [DHCP6.OptionTypes.OPTION_DOMAIN_LIST] = {
+
+ -- Create a new class instance
+ -- @param domain table containing the search domains
+ -- @return o new instance of class
+ new = function(self, domains)
+ local o = {
+ type = DHCP6.OptionTypes.OPTION_DOMAIN_LIST,
+ domains = domains or {},
+ }
+ setmetatable(o, self)
+ self.__index = self
+ return o
+ end,
+
+ -- Parse the data string and create an instance of the class
+ -- @param data string containing the data as received over the socket
+ -- @return opt new instance of option
+ parse = function(data)
+ local opt = DHCP6.Option[DHCP6.OptionTypes.OPTION_DOMAIN_LIST]:new()
+ local pos = 1
+
+ repeat
+ local domain = {}
+ repeat
+ local part
+ part, pos = string.unpack("s1", data, pos)
+ if ( part ~= "" ) then
+ table.insert(domain, part)
+ end
+ until( part == "" )
+ table.insert(opt.domains, table.concat(domain, "."))
+ until( pos > #data )
+ return opt
+ end,
+
+
+ },
+
+ [DHCP6.OptionTypes.OPTION_IA_PD] = {
+
+ -- Create a new class instance
+ -- @param iad number containing iad
+ -- @param t1 number containing t1
+ -- @param t2 number containing t2
+ -- @param option string containing any options
+ -- @return o new instance of class
+ new = function(self, iaid, t1, t2, options)
+ local o = {
+ type = DHCP6.OptionTypes.OPTION_IA_PD,
+ iaid = iaid,
+ t1 = t1 or 0,
+ t2 = t2 or 0,
+ options = options or "",
+ }
+ setmetatable(o, self)
+ self.__index = self
+ return o
+ end,
+
+ -- Converts option to a string
+ -- @return str string containing the class instance as string
+ __tostring = function(self)
+ local data = string.pack(">I4I4I4", self.iaid, self.t1, self.t2) .. self.options
+ return string.pack(">I2s2", self.type, data)
+ end,
+
+ },
+
+ [DHCP6.OptionTypes.OPTION_IA_NA] = {
+
+ -- Create a new class instance
+ -- @param iad number containing iad
+ -- @param t1 number containing t1
+ -- @param t2 number containing t2
+ -- @param option table containing any options
+ -- @return o new instance of class
+ new = function(self, iaid, t1, t2, options)
+ local o = {
+ type = DHCP6.OptionTypes.OPTION_IA_NA,
+ iaid = iaid,
+ t1 = t1 or 0,
+ t2 = t2 or 0,
+ options = options or {},
+ }
+ setmetatable(o, self)
+ self.__index = self
+ return o
+ end,
+
+ -- Parse the data string and create an instance of the class
+ -- @param data string containing the data as received over the socket
+ -- @return opt new instance of option
+ parse = function(data)
+ local opt = DHCP6.Option[DHCP6.OptionTypes.OPTION_IA_NA]:new()
+ local pos
+
+ opt.iaid, opt.t1, opt.t2, pos = string.unpack(">I4I4I4", data)
+
+ -- do we have any options
+ while ( pos < #data ) do
+ local typ, len, ipv6, pref_lt, valid_lt, options
+ typ, len, pos = string.unpack(">I2I2", data, pos)
+
+ if ( 5 == DHCP6.OptionTypes.OPTION_IAADDR ) then
+ local addr = { type = DHCP6.OptionTypes.OPTION_IAADDR }
+ addr.ipv6, addr.pref_lt, addr.valid_lt, pos = string.unpack(">c16I4I4", data, pos)
+ table.insert(opt.options, addr)
+ else
+ pos = pos + len
+ end
+ end
+ return opt
+ end,
+
+ -- Converts option to a string
+ -- @return str string containing the class instance as string
+ __tostring = function(self)
+ local data = string.pack(">I4I4I4", self.iaid, self.t1, self.t2)
+
+ -- TODO: we don't cover self.options here, we should probably add that
+ return string.pack(">I2s2", self.type, data)
+ end,
+ },
+
+ [DHCP6.OptionTypes.OPTION_SNTP_SERVERS] = {
+
+ -- Create a new class instance
+ -- @param servers table containing the NTP servers
+ -- @return o new instance of class
+ new = function(self, servers)
+ local o = {
+ type = DHCP6.OptionTypes.OPTION_SNTP_SERVERS,
+ servers = servers or {},
+ }
+ setmetatable(o, self)
+ self.__index = self
+ return o
+ end,
+
+ -- Parse the data string and create an instance of the class
+ -- @param data string containing the data as received over the socket
+ -- @return opt new instance of option
+ parse = function(data)
+ local opt = DHCP6.Option[DHCP6.OptionTypes.OPTION_SNTP_SERVERS]:new()
+ local pos, server
+
+ repeat
+ server, pos = string.unpack(">c16", data, pos)
+ table.insert( opt.servers, ipOps.str_to_ip(server) )
+ until( pos > #data )
+ return opt
+ end,
+ },
+
+ [DHCP6.OptionTypes.OPTION_CLIENT_FQDN] = {
+
+ -- Create a new class instance
+ -- @param fqdn string containing the fqdn
+ -- @return o new instance of class
+ new = function(self, fqdn)
+ local o = {
+ type = DHCP6.OptionTypes.OPTION_CLIENT_FQDN,
+ fqdn = fqdn or "",
+ }
+ setmetatable(o, self)
+ self.__index = self
+ return o
+ end,
+
+ -- Parse the data string and create an instance of the class
+ -- @param data string containing the data as received over the socket
+ -- @return opt new instance of option
+ parse = function(data)
+ local opt = DHCP6.Option[DHCP6.OptionTypes.OPTION_CLIENT_FQDN]:new()
+ local pos = 2
+ local pieces = {}
+
+ repeat
+ local tmp
+ tmp, pos = string.unpack("s1", data, pos)
+ table.insert(pieces, tmp)
+ until(pos >= #data)
+ opt.fqdn = table.concat(pieces, ".")
+ return opt
+ end,
+
+ }
+
+}
+
+
+DHCP6.Request = {
+
+ -- Create a new class instance
+ -- @param msgtype number containing the message type
+ -- @param xid number containing the transaction id
+ -- @param opts table containing any request options
+ -- @return o new instance of class
+ new = function(self, msgtype, xid, opts)
+ local o = {
+ type = msgtype,
+ xid = xid or math.random(1048575),
+ opts = opts or {}
+ }
+ setmetatable(o, self)
+ self.__index = self
+ return o
+ end,
+
+ -- Adds a new DHCP6 option to the request
+ -- @param opt instance of object to add to the request
+ addOption = function(self, opt)
+ table.insert(self.opts, opt)
+ end,
+
+ -- Converts option to a string
+ -- @return str string containing the class instance as string
+ __tostring = function(self)
+ local tmp = (self.type << 24) + self.xid
+ local data = {}
+
+ for _, opt in ipairs(self.opts) do
+ data[#data+1] = tostring(opt)
+ end
+ return string.pack(">I4", tmp) .. table.concat(data)
+ end,
+
+}
+
+-- The Response class handles responses from the server
+DHCP6.Response = {
+
+ -- Creates a new instance of the response class
+ -- @param msgtype number containing the type of DHCP6 message
+ -- @param xid number containing the transaction ID
+ new = function(self, msgtype, xid, opts)
+ local o = {
+ msgtype = msgtype,
+ xid = xid,
+ opts = opts or {},
+ }
+ setmetatable(o, self)
+ self.__index = self
+ return o
+ end,
+
+ -- Parse the data string and create an instance of the class
+ -- @param data string containing the data as received over the socket
+ -- @return opt new instance of option
+ parse = function(data)
+ local resp = DHCP6.Response:new()
+ local tmp, pos = string.unpack(">I4", data)
+
+ resp.msgtype = (tmp & 0xFF000000)
+ resp.msgtype = (resp.msgtype >> 24)
+ resp.xid = (tmp & 0x00FFFFFF)
+ while( pos < #data ) do
+ local opt = {}
+ opt.type, opt.data, pos = string.unpack(">I2s2", data, pos)
+ if ( DHCP6.Option[opt.type] and DHCP6.Option[opt.type].parse ) then
+ local opt_parsed = DHCP6.Option[opt.type].parse(opt.data)
+ if ( not(opt_parsed) ) then
+ table.insert(resp.opts, { type = opt.type, raw = opt.data })
+ else
+ table.insert(resp.opts, { type = opt.type, resp = opt_parsed, raw = opt.data })
+ end
+ else
+ stdnse.debug2("No option decoder for type: %d; len: %d", opt.type, #(opt.data or ""))
+ table.insert(resp.opts, { type = opt.type, raw = opt.data })
+ end
+ end
+ return resp
+ end
+
+}
+
+-- Table of option to string converters
+-- Each option should have its own function to convert an instance of option
+-- to a printable string.
+--
+-- TODO: These functions could eventually be moved to a method in its
+-- respective class.
+OptionToString = {
+
+ [DHCP6.OptionTypes.OPTION_CLIENTID] = function(opt)
+ local HWTYPE_ETHER = 1
+ if ( HWTYPE_ETHER == opt.hwtype ) then
+ local mac = stdnse.tohex(opt.mac):upper()
+ mac = mac:gsub("..", "%1:"):sub(1, -2)
+ local tm = datetime.format_timestamp(opt.time)
+ return "Client identifier", ("MAC: %s; Time: %s"):format(mac, tm)
+ end
+ end,
+
+ [DHCP6.OptionTypes.OPTION_SERVERID] = function(opt)
+ local topic, str = OptionToString[DHCP6.OptionTypes.OPTION_CLIENTID](opt)
+ return "Server identifier", str
+ end,
+
+ [DHCP6.OptionTypes.OPTION_IA_NA] = function(opt)
+ if ( opt.options and 1 == #opt.options ) then
+ local ipv6 = ipOps.str_to_ip(opt.options[1].ipv6)
+ return "Non-temporary Address", ipv6
+ end
+ end,
+
+ [DHCP6.OptionTypes.OPTION_DNS_SERVERS] = function(opt)
+ local servers = {}
+ for _, srv in ipairs(opt.servers) do
+ local ipv6 = ipOps.str_to_ip(srv)
+ table.insert(servers, ipv6)
+ end
+ return "DNS Servers", table.concat(servers, ",")
+ end,
+
+ [DHCP6.OptionTypes.OPTION_DOMAIN_LIST] = function(opt)
+ return "Domain Search", table.concat(opt.domains, ", ")
+ end,
+
+ [DHCP6.OptionTypes.OPTION_STATUS_CODE] = function(opt)
+ return "Error", ("Code: %d; Message: %s"):format(opt.code, opt.msg)
+ end,
+
+ [DHCP6.OptionTypes.OPTION_SNTP_SERVERS] = function(opt)
+ return "NTP Servers", table.concat(opt.servers, ", ")
+ end,
+}
+
+-- The Helper class serves as the main interface to scripts
+Helper = {
+
+ -- Creates a new Helper class instance
+ -- @param iface string containing the interface name
+ -- @param options table containing any options, currently
+ -- <code>timeout</code> - socket timeout in ms
+ -- @return o new instance of Helper
+ new = function(self, iface, options)
+ local o = {
+ iface = iface,
+ options = options or {},
+ }
+ setmetatable(o, self)
+ self.__index = self
+
+ local info, err = nmap.get_interface_info(iface)
+ -- if we fail to get interface info, don't return a helper
+ -- this is true on OS X for interfaces like: p2p0 and vboxnet0
+ if ( not(info) and err ) then
+ return
+ end
+ o.mac = info.mac
+ o.socket = nmap.new_socket("udp")
+ o.socket:bind(nil, 546)
+ o.socket:set_timeout(o.options.timeout or 5000)
+ return o
+ end,
+
+ -- Sends a DHCP6 Solicit message to the server, essentially requesting a new
+ -- IPv6 non-temporary address
+ -- @return table of results suitable for use with
+ -- <code>stdnse.format_output</code>
+ solicit = function(self)
+ local req = DHCP6.Request:new( DHCP6.Type.SOLICIT )
+ local option = DHCP6.Option
+ req:addOption(option[DHCP6.OptionTypes.OPTION_ELAPSED_TIME]:new())
+ req:addOption(option[DHCP6.OptionTypes.OPTION_CLIENTID]:new(self.mac))
+
+ local iaid = string.unpack(">I4", self.mac:sub(3))
+ req:addOption(option[DHCP6.OptionTypes.OPTION_IA_NA]:new(iaid, 3600, 5400))
+
+ self.host, self.port = { ip = "ff02::1:2" }, { number = 547, protocol = "udp"}
+ local status, err = self.socket:sendto( self.host, self.port, tostring(req) )
+ if ( not(status) ) then
+ self.host.ip = ("%s%%%s"):format(self.host.ip, self.iface)
+ status, err = self.socket:sendto( self.host, self.port, tostring(req) )
+ if ( not(status) ) then
+ return false, "Failed to send DHCP6 request to server"
+ end
+ end
+
+ local resp, retries = {}, 3
+ repeat
+ retries = retries - 1
+ local status, data = self.socket:receive()
+ if ( not(status) ) then
+ return false, "Failed to receive DHCP6 request from server"
+ end
+
+ resp = DHCP6.Response.parse(data)
+ if ( not(resp) ) then
+ return false, "Failed to decode DHCP6 response from server"
+ end
+ until( req.xid == resp.xid or retries == 0 )
+
+ if ( req.xid ~= resp.xid ) then
+ return false, "Failed to receive DHCP6 response from server"
+ end
+
+ local result, result_options = {}, { name = "Options" }
+ local resptype = DHCP6.TypeStr[resp.msgtype] or ("Unknown (%d)"):format(resp.msgtype)
+
+ table.insert(result, ("Message type: %s"):format(resptype))
+ table.insert(result, ("Transaction id: %d"):format(resp.xid))
+
+ for _, opt in ipairs(resp.opts or {}) do
+ if ( OptionToString[opt.type] ) then
+ local topic, str = OptionToString[opt.type](opt.resp)
+ if ( topic and str ) then
+ table.insert(result_options, ("%s: %s"):format(topic, str))
+ end
+ else
+ stdnse.debug2("No decoder for option type: %d", opt.type)
+ end
+ end
+ table.insert(result, result_options)
+ return true, result
+ end,
+}
+
+
+return _ENV;
generated by cgit v1.2.3 (git 2.39.1) at 2024-06-12 11:12:36 +0000