1 files changed, 187 insertions, 0 deletions
diff --git a/include/dnsjit/output/dnscli.lua b/include/dnsjit/output/dnscli.lua
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+++ b/include/dnsjit/output/dnscli.lua
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+-- 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 <http://www.gnu.org/licenses/>.
+
+-- dnsjit.output.dnscli
+-- DNS aware UDP/TCP/TLS client
+--   local dnscli = require("dnsjit.output.dnscli")
+-- .SS UDP Receiver Chain
+--   local output = dnscli.new(dnscli.UDP)
+--   output:connect("127.0.0.1", "53")
+--   input:receiver(output)
+-- .SS TCP Nonblocking
+--   local output = dnscli.new(dnscli.TCP + dnscli.NONBLOCKING)
+--   output:send(object)
+--
+-- The DNS client can a
+-- .I core.object.dns
+-- or a
+-- .I core.object.payload
+-- object via the receiver interface or using
+-- .I send()
+-- and send it as DNS query after which it can receive the response by using
+-- the producer interface.
+-- If the object being sent is a
+-- .I core.object.dns
+-- then it will look at
+-- .I includes_dnslen
+-- attribute and depending on the protocol it will disregard, include or send
+-- the DNS length as an extra packet.
+-- If the object being sent is a
+-- .I core.object.payload
+-- then no special handling will be done and it will be sent as is.
+-- When receiving responses the producer interface will generate
+-- .I core.object.payload
+-- objects which may include the DNS length depending on the protocol used and
+-- must be handled by the caller.
+-- .SS MODES
+-- These transport modes and options are available when creating a new Dnscli
+-- output.
+-- .TP
+-- UDP
+-- Create an output using UDP.
+-- .TP
+-- TCP
+-- Create an output using TCP.
+-- .TP
+-- TLS
+-- Create an output using TCP and encrypt it with TLS.
+-- .TP
+-- NONBLOCKING
+-- Make the client nonblocking, see
+-- .I send()
+-- and
+-- .IR produce() .
+module(...,package.seeall)
+
+require("dnsjit.output.dnscli_h")
+local ffi = require("ffi")
+local C = ffi.C
+
+local t_name = "output_dnscli_t"
+local output_dnscli_t = ffi.typeof(t_name)
+local Dnscli = {
+    NONBLOCKING = 0x1,
+    UDP = 0x10,
+    TCP = 0x20,
+    TLS = 0x30,
+}
+
+-- Create a new Dnscli output.
+function Dnscli.new(mode)
+    local self = {
+        obj = output_dnscli_t(),
+    }
+    C.output_dnscli_init(self.obj, mode)
+    ffi.gc(self.obj, C.output_dnscli_destroy)
+    return setmetatable(self, { __index = Dnscli })
+end
+
+-- Set or return the timeout used for sending and reciving, must be used before
+-- .IR connect() .
+function Dnscli:timeout(seconds, nanoseconds)
+    if seconds == nil and nanoseconds == nil then
+        return self.obj.timeout
+    end
+    if nanoseconds == nil then
+        nanoseconds = 0
+    end
+    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 Dnscli:connect(host, port)
+    return C.output_dnscli_connect(self.obj, host, port)
+end
+
+-- Return if nonblocking mode is on (true) or off (false).
+function Dnscli:nonblocking()
+    if self.obj.nonblocking == 1 then
+        return true
+    end
+    return false
+end
+
+-- Send an object and optionally continue sending after
+-- .I sent
+-- bytes.
+-- Unlike the receive interface this function lets you know if the sending was
+-- successful or not which might be needed on nonblocking connections.
+-- Returns -2 on error, -1 if interrupted, timed out or unable to send due to
+-- nonblocking, or the number of bytes sent.
+-- .B Note
+-- the counters for sent, received, errors and timeouts are not affected by
+-- this function.
+function Dnscli:send(object, sent)
+    if sent == nil then
+        sent = 0
+    end
+    return C.output_dnscli_send(self.obj, object, sent)
+end
+
+-- Return the C functions and context for receiving objects, these objects
+-- will be sent.
+function Dnscli:receive()
+    return C.output_dnscli_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.
+-- 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.
+-- The producer returns nil on error.
+function Dnscli:produce()
+    return C.output_dnscli_producer(self.obj), self.obj
+end
+
+-- Return the number of "packets" sent, actually the number of completely sent
+-- payloads.
+function Dnscli:packets()
+    return tonumber(self.obj.pkts)
+end
+
+-- Return the number of "packets" received, actually the number of successful
+-- calls to
+-- .IR recvfrom (2)
+-- that returned data.
+function Dnscli:received()
+    return tonumber(self.obj.pkts_recv)
+end
+
+-- Return the number of errors when sending or receiving.
+function Dnscli:errors()
+    return tonumber(self.obj.errs)
+end
+
+-- Return the number of timeouts when sending or receiving.
+function Dnscli:timeouts()
+    return tonumber(self.obj.timeouts)
+end
+
+-- core.object.dns (3),
+-- core.object.payload (3),
+-- core.timespec (3)
+return Dnscli