Edit File: bjnp.lua
--- -- An implementation of the Canon BJNP protocol used to discover and query -- Canon network printers and scanner devices. -- -- The implementation is pretty much based on Wireshark decoded messages -- the cups-bjnp implementation and the usual guesswork. -- -- @author "Patrik Karlsson <patrik [at] cqure.net>" -- local bin = require("bin") local bit = require("bin") local nmap = require("nmap") local os = require("os") local stdnse = require("stdnse") local string = require("string") local table = require("table") _ENV = stdnse.module("bjnp", stdnse.seeall) BJNP = { -- The common BJNP header Header = { new = function(self, o) o = o or {} o = { id = o.id or "BJNP", type = o.type or 1, code = o.code, seq = o.seq or 1, session = o.session or 0, length = o.length or 0, } assert(o.code, "code argument required") setmetatable(o, self) self.__index = self return o end, parse = function(data) local hdr = BJNP.Header:new({ code = -1 }) local pos pos, hdr.id, hdr.type, hdr.code, hdr.seq, hdr.session, hdr.length = bin.unpack(">A4CCISI", data) return hdr end, __tostring = function(self) return bin.pack(">ACCISI", self.id, self.type, self.code, self.seq, self.session, self.length ) end }, -- Scanner related code Scanner = { Code = { DISCOVER = 1, IDENTITY = 48, }, Request = { Discover = { new = function(self) local o = { header = BJNP.Header:new( { type = 2, code = BJNP.Scanner.Code.DISCOVER }) } setmetatable(o, self) self.__index = self return o end, __tostring = function(self) return tostring(self.header) end, }, Identity = { new = function(self) local o = { header = BJNP.Header:new( { type = 2, code = BJNP.Scanner.Code.IDENTITY, length = 4 }), data = 0 } setmetatable(o, self) self.__index = self return o end, __tostring = function(self) return tostring(self.header) .. bin.pack(">I", self.data) end, } }, Response = { Identity = { new = function(self) local o = {} setmetatable(o, self) self.__index = self return o end, parse = function(data) local identity = BJNP.Scanner.Response.Identity:new() identity.header = BJNP.Header.parse(data) local pos = #tostring(identity.header) + 1 local pos, len = bin.unpack(">S", data, pos) if ( len ) then pos, identity.data = bin.unpack("A" .. len - 2, data, pos) return identity end end, } } }, -- Printer related code Printer = { Code = { DISCOVER = 1, IDENTITY = 48, }, Request = { Discover = { new = function(self) local o = { header = BJNP.Header:new( { code = BJNP.Printer.Code.DISCOVER }) } setmetatable(o, self) self.__index = self return o end, __tostring = function(self) return tostring(self.header) end, }, Identity = { new = function(self) local o = { header = BJNP.Header:new( { code = BJNP.Printer.Code.IDENTITY }) } setmetatable(o, self) self.__index = self return o end, __tostring = function(self) return tostring(self.header) end, } }, Response = { Identity = { new = function(self) local o = {} setmetatable(o, self) self.__index = self return o end, parse = function(data) local identity = BJNP.Printer.Response.Identity:new() identity.header = BJNP.Header.parse(data) local pos = #tostring(identity.header) + 1 local pos, len = bin.unpack(">S", data, pos) if ( len ) then pos, identity.data = bin.unpack("A" .. len - 2, data, pos) return identity end end, } }, } } -- Helper class, the main script writer interface Helper = { -- Creates a new Helper instance -- @param host table -- @param port table -- @param options table containing one or more of the following fields; -- <code>timeout</code> - the timeout in milliseconds for socket communication -- <code>bcast</code> - instructs the library that the host is a broadcast -- address -- @return o new instance of Helper new = function(self, host, port, options) local o = { host = host, port = port, options = options or {} } o.options.timeout = o.options.timeout or 5000 setmetatable(o, self) self.__index = self return o end, -- Connects the socket to the device -- This should always be called, regardless if the broadcast option is set -- or not. -- -- @return status, true on success, false on failure -- @return err string containing the error message if status is false connect = function(self) self.socket = nmap.new_socket(( self.options.bcast and "udp" )) self.socket:set_timeout(self.options.timeout) if ( not(self.options.bcast) ) then return self.socket:connect(self.host, self.port) end return true end, -- Discover network devices using either broadcast or unicast -- @param packet discovery packet (printer or scanner) -- @return status, true on success, false on failure -- @return devices table containing discovered devices when status is true -- errmsg string containing the error message when status is false discoverDevice = function(self, packet) if ( not(self.options.bcast) ) then if ( not(self.socket:send(tostring(packet))) ) then return false, "Failed to send request to server" end else if ( not(self.socket:sendto(self.host, self.port, tostring(packet))) ) then return false, "Failed to send request to server" end end -- discover run in loop local devices, tmp = {}, {} local start = os.time() while( true ) do local status, data = self.socket:receive() if ( not(status) or ( os.time() - start > ( self.options.timeout/1000 - 1 ) )) then break end local status, _, _, rhost = self.socket:get_info() tmp[rhost] = true end for host in pairs(tmp) do table.insert(devices, host) end return true, ( self.options.bcast and devices or ( #devices > 0 and devices[1] )) end, -- Discover BJNP supporting scanners discoverScanner = function(self) return self:discoverDevice(BJNP.Scanner.Request.Discover:new()) end, -- Discover BJNP supporting printers discoverPrinter = function(self) return self:discoverDevice(BJNP.Printer.Request.Discover:new()) end, -- Gets a printer identity (additional information) -- @param devtype string containing either the string printer or scanner -- @return status, true on success, false on failure -- @return attribs table containing device attributes when status is true -- errmsg string containing the error message when status is false getDeviceIdentity = function(self, devtype) -- Were currenlty only decoding this as I don't know what the other cruft is local attrib_names = { ["scanner"] = { { ['MFG'] = "Manufacturer" }, { ['MDL'] = "Model" }, { ['DES'] = "Description" }, { ['CMD'] = "Command" }, }, ["printer"] = { { ['MFG'] = "Manufacturer" }, { ['MDL'] = "Model" }, { ['DES'] = "Description" }, { ['VER'] = "Firmware version" }, { ['CMD'] = "Command" }, } } local identity if ( "printer" == devtype ) then identity = BJNP.Printer.Request.Identity:new() elseif ( "scanner" == devtype ) then identity = BJNP.Scanner.Request.Identity:new() end assert(not(self.options.bcast), "getIdentity is not supported for broadcast") if ( not(self.socket:send(tostring(identity))) ) then return false, "Failed to send request to server" end local status, data = self.socket:receive() if ( not(status) ) then return false, "Failed to receive response from server" end local identity if ( "printer" == devtype ) then identity = BJNP.Printer.Response.Identity.parse(data) elseif ( "scanner" == devtype ) then identity = BJNP.Scanner.Response.Identity.parse(data) end if ( not(identity) ) then return false, "Failed to parse identity" end local attrs, kvps = {}, {} for k, v in ipairs(stdnse.strsplit(";", identity.data)) do local nm, val = v:match("^([^:]*):(.*)$") if ( nm ) then kvps[nm] = val end end for _, attrib in ipairs(attrib_names[devtype]) do local short, long = next(attrib) if ( kvps[short] ) then table.insert(attrs, ("%s: %s"):format(long, kvps[short])) end end return true, attrs end, -- Retrieves information related to the printer getPrinterIdentity = function(self) return self:getDeviceIdentity("printer") end, -- Retrieves information related to the scanner getScannerIdentity = function(self) return self:getDeviceIdentity("scanner") end, -- Closes the connection -- @return status, true on success, false on failure -- @return errmsg string containing the error message when status is false close = function(self) return self.socket:close() end } return _ENV;