Edit File: srvloc.lua
--- A relatively small implementation of the Service Location Protocol. -- It was initially designed to support requests for discovering Novell NCP -- servers, but should work for any other service as well. -- -- The implementation is based on the following classes: -- * Request.Service -- - Contains necessary code to produce a service request -- -- * Request.Attributes -- - Contains necessary code to produce a attribute request -- -- * Reply.Service -- - Contains necessary code to process and parse the response to the -- service request -- -- * Reply.Attributes -- - Contains necessary code to process and parse the response to the -- attribute request -- -- The following code illustrates intended use of the library: -- -- <code> -- local helper = srvloc.Helper:new() -- local status, tree = helper:ServiceRequest("ndap.novell", "DEFAULT") -- if ( status ) then tree = tree:match("%/%/%/(.*)%.$") end -- </code> --@author Patrik Karlsson <patrik@cqure.net> --@copyright Same as Nmap--See http://nmap.org/book/man-legal.html -- Version 0.1 -- Created 24/04/2011 - v0.1 - created by Patrik Karlsson <patrik@cqure.net> local bin = require "bin" local bit = require "bit" local nmap = require "nmap" local stdnse = require "stdnse" local table = require "table" _ENV = stdnse.module("srvloc", stdnse.seeall) PacketFunction = { SERVICE_REQUEST = 1, SERVICE_REPLY = 2, ATTRIB_REQUEST = 6, } Reply = { Service = { --- Creates a new instance of the Reply.Service class -- @param data string containing the raw reply as read from the socket -- @return o instance of Reply.Service new = function(self, data) local o = { data = data } setmetatable(o, self) self.__index = self o:parse(data) return o end, --- Parses the service reply raw packet data -- @param data string containing the raw reply as read from the socket parse = function(self, data) local pos local len_hi, len_lo pos, self.version, self.func, len_hi, len_lo = bin.unpack(">CCCS", data) self.len = bit.lshift(len_hi, 16) + len_lo pos, self.flags = bin.unpack(">S", data, pos) local neo_hi, neo_lo pos, neo_hi, neo_lo = bin.unpack(">CS", data, pos) self.next_extension_offset = bit.lshift(neo_hi, 16) + neo_lo local lang_tag_len pos, self.xid, lang_tag_len = bin.unpack(">SS", data, pos) pos, self.lang_tag = bin.unpack("A" .. lang_tag_len, data, pos) local no_urls, reserved, url_len pos, self.error_code, no_urls = bin.unpack(">SS", data, pos) if ( no_urls > 0 ) then pos, reserved, self.url_lifetime, url_len = bin.unpack(">CSS", data, pos) local num_auths pos, self.url, num_auths = bin.unpack("A" .. url_len .. "C", data, pos) end end, --- Attempts to create an instance by reading data off the socket -- @param socket socket conected to the SRVLOC service -- @return new instance of the Reply.Service class fromSocket = function(socket) local status, data = socket:receive() if ( not(status) ) then return end return Reply.Service:new(data) end, --- Gets the url value from the reply -- @return uri string containing the reply url getUrl = function(self) return self.url end, }, Attribute = { --- Creates a new instance of Reply.Attribute -- @param data string containing the raw reply as read from the socket -- @return o instance of Reply.Attribute new = function(self, data) local o = { data = data } setmetatable(o, self) self.__index = self o:parse(data) return o end, --- Parses the service reply raw packet data -- @param data string containing the raw reply as read from the socket parse = function(self, data) local pos local len_hi, len_lo pos, self.version, self.func, len_hi, len_lo = bin.unpack(">CCCS", data) self.len = bit.lshift(len_hi, 16) + len_lo pos, self.flags = bin.unpack(">S", data, pos) local neo_hi, neo_lo pos, neo_hi, neo_lo = bin.unpack(">CS", data, pos) self.next_extension_offset = bit.lshift(neo_hi, 16) + neo_lo local lang_tag_len pos, self.xid, lang_tag_len = bin.unpack(">SS", data, pos) pos, self.lang_tag = bin.unpack("A" .. lang_tag_len, data, pos) local attrib_list_len pos, self.error_code, attrib_list_len = bin.unpack(">SS", data, pos) pos, self.attrib_list = bin.unpack("A"..attrib_list_len, data, pos) local num_auths pos, num_auths = bin.unpack("C", data, pos) end, --- Attempts to create an instance by reading data off the socket -- @param socket socket conected to the SRVLOC service -- @return new instance of the Reply.Attribute class fromSocket = function(socket) local status, data = socket:receive() if ( not(status) ) then return end return Reply.Attribute:new(data) end, --- Gets the attribute list -- @return attrib_list getAttribList = function(self) return self.attrib_list end, } } Request = { -- The attribute request Attribute = { --- Creates a new instance of the Attribue request -- @return o instance of Attribute new = function(self) local o = { lang_tag = "en", version = 2, service_type = "", scope = "", next_extension_offset = 0, prev_resp_list_len = 0, slp_spi_len = 0 } setmetatable(o, self) self.__index = self return o end, --- Sets the request scope -- @param scope string containing the request scope setScope = function(self, scope) self.scope = scope end, --- Sets the language tag -- @param lang string containing the language setLangTag = function(self, lang) self.lang_tag = lang end, --- Sets the request flags -- @param flags number containing the numeric flag representation setFlags = function(self, flags) self.flags = flags end, --- Sets the request XID -- @param xid number containing the request XID setXID = function(self, xid) self.xid = xid end, --- Sets the request function -- @param func number containing the request function number setFunction = function(self, func) self.func = func end, --- Sets the request taglist -- @param tl string containing the taglist setTagList = function(self, tl) self.tag_list = tl end, --- Sets the request url -- @param u string containing the url setUrl = function(self, u) self.url = u end, --- "Serializes" the request to a string -- @return data string containing a string representation of the request __tostring = function(self) assert(self.func, "Packet function was not specified") assert(self.scope, "Packet scope was not specified") local BASE_LEN = 24 local len = BASE_LEN + #self.lang_tag + self.prev_resp_list_len + self.slp_spi_len + #self.service_type + #self.url + #self.tag_list + #self.scope local len_hi = bit.band(bit.rshift(len, 16), 0x00FF) local len_lo = bit.band(len, 0xFFFF) local neo_hi = bit.band(bit.rshift(self.next_extension_offset, 16), 0x00FF) local neo_lo = bit.band(self.next_extension_offset, 0xFFFF) local data = bin.pack(">CCCSSCSSSASSASASAS", self.version, self.func, len_hi, len_lo, self.flags, neo_hi, neo_lo, self.xid, #self.lang_tag, self.lang_tag, self.prev_resp_list_len, #self.url, self.url, #self.scope, self.scope, #self.tag_list, self.tag_list, self.slp_spi_len) return data end }, -- The Service request Service = { --- Creates a new instance of the Service request -- @return o instance of Service new = function(self) local o = { lang_tag = "en", version = 2, service_type = "", scope = "", next_extension_offset = 0, prev_resp_list_len = 0, predicate_len = 0, slp_spi_len = 0 } setmetatable(o, self) self.__index = self return o end, --- Sets the service type of the request -- @param t string containing the type of the request setServiceType = function(self, t) self.service_type = t end, --- Sets the request scope -- @param scope string containing the request scope setScope = function(self, scope) self.scope = scope end, --- Sets the language tag -- @param lang string containing the language setLangTag = function(self, lang) self.lang_tag = lang end, --- Sets the request flags -- @param flags number containing the numeric flag representation setFlags = function(self, flags) self.flags = flags end, --- Sets the request XID -- @param xid number containing the request XID setXID = function(self, xid) self.xid = xid end, --- Sets the request function -- @param func number containing the request function number setFunction = function(self, func) self.func = func end, --- "Serializes" the request to a string -- @return data string containing a string representation of the request __tostring = function(self) assert(self.func, "Packet function was not specified") assert(self.scope, "Packet scope was not specified") local BASE_LEN = 24 local len = BASE_LEN + #self.lang_tag + self.prev_resp_list_len + self.predicate_len + self.slp_spi_len + #self.service_type + #self.scope local len_hi = bit.band(bit.rshift(len, 16), 0x00FF) local len_lo = bit.band(len, 0xFFFF) local neo_hi = bit.band(bit.rshift(self.next_extension_offset, 16), 0x00FF) local neo_lo = bit.band(self.next_extension_offset, 0xFFFF) local data = bin.pack(">CCCSSCSSSASSASASS", self.version, self.func, len_hi, len_lo, self.flags, neo_hi, neo_lo, self.xid, #self.lang_tag, self.lang_tag, self.prev_resp_list_len, #self.service_type, self.service_type, #self.scope, self.scope, self.predicate_len, self.slp_spi_len) return data end } } -- The Helper class serves as primary interface for scripts using the libraryy Helper = { new = function(self, host, port) local o = { xid = 1, socket = nmap.new_socket("udp") } setmetatable(o, self) self.__index = self local family = nmap.address_family() o.host = host or (family=="inet6" and "FF02::116" or "239.255.255.253") o.port = port or { number=427, proto="udp" } return o end, --- Sends a service request and waits for the response -- @param srvtype string containing the service type to query -- @param scope string containing the scope of the request -- @return true on success, false on failure -- @return url string (on success) containing the url of the ServiceReply -- @return err string (on failure) containing the error message ServiceRequest = function(self, srvtype, scope) local srvtype = srvtype or "" local scope = scope or "" local sr = Request.Service:new() sr:setXID(self.xid) sr:setServiceType(srvtype) sr:setScope(scope) sr:setFunction(PacketFunction.SERVICE_REQUEST) sr:setFlags(0x2000) self.socket:set_timeout(5000) self.socket:sendto( self.host, self.port, tostring(sr) ) local result = {} repeat local r = Reply.Service.fromSocket(self.socket) if ( r ) then table.insert(result, r:getUrl()) end self.xid = self.xid + 1 until(not(r)) if ( #result == 0 ) then return false, "ERROR: Helper.Locate no response received" end return true, result end, --- Requests an attribute from the server -- @param url as retrieved by the Service request -- @param scope string containing the request scope -- @param taglist string containing the request tag list AttributeRequest = function(self, url, scope, taglist) local url = url or "" local scope = scope or "" local taglist = taglist or "" local ar = Request.Attribute:new() ar:setXID(self.xid) ar:setScope(scope) ar:setUrl(url) ar:setTagList(taglist) ar:setFunction(PacketFunction.ATTRIB_REQUEST) ar:setFlags(0x2000) self.socket:set_timeout(5000) self.socket:sendto( self.host, self.port, tostring(ar) ) local r = Reply.Attribute.fromSocket(self.socket) self.xid = self.xid + 1 if ( not(r) ) then return false, "ERROR: Helper.Locate no response received" end return true, r:getAttribList() end, close = function(self) return self.socket:close() end, } return _ENV;