-- Copyright (c) 2018-2021, OARC, Inc. -- All rights reserved. -- -- This file is part of dnsjit. -- -- dnsjit is free software: you can redistribute it and/or modify -- it under the terms of the GNU General Public License as published by -- the Free Software Foundation, either version 3 of the License, or -- (at your option) any later version. -- -- dnsjit is distributed in the hope that it will be useful, -- but WITHOUT ANY WARRANTY; without even the implied warranty of -- MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the -- GNU General Public License for more details. -- -- You should have received a copy of the GNU General Public License -- along with dnsjit. If not, see . -- dnsjit.output.tcpcli -- Simple, length aware, TCP client -- local output = require("dnsjit.output.tcpcli").new("127.0.0.1", "53") -- -- Simple TCP client that takes any payload you give it, sends the length of -- the payload as an unsigned 16 bit integer and then sends the payload. -- When receiving it will first retrieve the length of the payload as an -- unsigned 16 bit integer and it will stall until it gets, even if -- nonblocking mode is used. -- Then it will retrieve at least that amount of bytes, if nonblocking mode -- is used here then it will return a payload object with length zero if -- there was nothing to receive or if the full payload have not been received -- yet. -- Additional calls will continue retrieving the payload. -- .SS Attributes -- .TP -- timeout -- A -- .I core.timespec -- that is used when producing objects. module(...,package.seeall) require("dnsjit.output.tcpcli_h") local ffi = require("ffi") local C = ffi.C local t_name = "output_tcpcli_t" local output_tcpcli_t = ffi.typeof(t_name) local Tcpcli = {} -- Create a new Tcpcli output. function Tcpcli.new() local self = { obj = output_tcpcli_t(), } C.output_tcpcli_init(self.obj) ffi.gc(self.obj, C.output_tcpcli_destroy) return setmetatable(self, { __index = Tcpcli }) end -- Set the timeout when producing objects. function Tcpcli:timeout(seconds, nanoseconds) self.obj.timeout.sec = seconds self.obj.timeout.nsec = nanoseconds end -- Connect to the -- .I host -- and -- .I port -- and return 0 if successful. function Tcpcli:connect(host, port) return C.output_tcpcli_connect(self.obj, host, port) end -- Enable (true) or disable (false) nonblocking mode and -- return 0 if successful, if -- .I bool -- is not specified then return if nonblocking mode is on (true) or off (false). function Tcpcli:nonblocking(bool) if bool == nil then if C.output_tcpcli_nonblocking(self.obj) == 1 then return true end return false elseif bool == true then return C.output_tcpcli_set_nonblocking(self.obj, 1) else return C.output_tcpcli_set_nonblocking(self.obj, 0) end end -- Return the C functions and context for receiving objects, these objects -- will be sent. function Tcpcli:receive() return C.output_tcpcli_receiver(self.obj), self.obj end -- Return the C functions and context for producing objects, these objects -- are received. -- If nonblocking mode is enabled the producer will return a payload object -- with length zero if there was nothing to receive or if the full payload -- have not been received yet. -- If nonblocking mode is disabled the producer will wait for data and if -- timed out (see -- .IR timeout ) -- it will return a payload object with length zero. -- If a timeout happens during during the first stage, getting the length, it -- will fail and return nil. -- Additional calls will continue retrieving the payload. -- The producer returns nil on error. function Tcpcli:produce() return C.output_tcpcli_producer(self.obj), self.obj end -- Return the number of "packets" sent, actually the number of completely sent -- payloads. function Tcpcli:packets() return tonumber(self.obj.pkts) end -- Return the number of "packets" received, actually the number of completely -- received DNS messages. function Tcpcli:received() return tonumber(self.obj.pkts_recv) end -- Return the number of errors when sending. function Tcpcli:errors() return tonumber(self.obj.errs) end return Tcpcli