zapret-auto: optimize detector code

lua/zapret-auto.lua

@@ -72,42 +72,53 @@ end
 -- standard failure detector
 -- works with tcp and udp
 -- detected failures:
---   incoming RST (within `options.seq_rst`)
+--   incoming RST
---   incoming http redirection (if no 'options.no_http_redirect')
+--   incoming http redirection
---   outgoing retransmissions (`options.retrans` threshold)
+--   outgoing retransmissions
---   udp : >= `options.udp_out` outgoings with <= 'options.udp_in' incomings
+--   udp too much out with too few in
--- stops dectecting after seq 'options.maxseq'
+-- arg: seq=<rseq> - tcp: if packet is beyond this relative sequence number treat this connection as successful. default is 64K
-function standard_failure_detector(desync, crec, options)
+-- arg: retrans=N - tcp: retrans count threshold. default is 3
+-- arg: rst=<rseq> - tcp: maximum relative sequence number to treat incoming RST as DPI reset. default is 1
+-- arg: no_http_redirect - tcp: disable http_reply dpi redirect trigger
+-- arg: udp_out - udp: >= outgoing udp packets. default is 3
+-- arg: udp_in - udp: with <= incoming udp packets. default is 1
+function standard_failure_detector(desync, crec, arg)
 	if crec.nocheck then return false end
 
+	local seq_rst = tonumber(arg.rst) or 1
+	local retrans = tonumber(arg.retrans) or 3
+	local maxseq = tonumber(arg.seq) or 0x10000
+	local udp_in = tonumber(arg.udp_in) or 1
+	local udp_out = tonumber(arg.udp_out) or 3
+
 	local trigger = false
 	if desync.dis.tcp then
 		local seq = pos_get(desync,'s')
-		if options.maxseq and seq>options.maxseq then
+		if maxseq and seq>maxseq then
-			DLOG("standard_failure_detector: s"..seq.." is beyond s"..options.maxseq..". treating connection as successful")
+			DLOG("standard_failure_detector: s"..seq.." is beyond s"..maxseq..". treating connection as successful")
 			crec.nocheck = true
 			return false
 		end
 
 		if desync.outgoing then
-			if #desync.dis.payload>0 and options.retrans and (crec.retrans or 0)<options.retrans then
+			if #desync.dis.payload>0 and retrans and (crec.retrans or 0)<retrans then
 				if is_retransmission(desync) then
 					crec.retrans = crec.retrans and (crec.retrans+1) or 1
-					DLOG("standard_failure_detector: retransmission "..crec.retrans.."/"..options.retrans)
+					DLOG("standard_failure_detector: retransmission "..crec.retrans.."/"..retrans)
-					trigger = crec.retrans>=options.retrans
+					trigger = crec.retrans>=retrans
 				end
 			end
 		else
-			if options.seq_rst and bitand(desync.dis.tcp.th_flags, TH_RST)~=0 then
+			if seq_rst and bitand(desync.dis.tcp.th_flags, TH_RST)~=0 then
-				trigger = seq<=options.seq_rst
+				trigger = seq<=seq_rst
 				if b_debug then
 					if trigger then
-						DLOG("standard_failure_detector: incoming RST s"..seq.." in range s"..options.seq_rst)
+						DLOG("standard_failure_detector: incoming RST s"..seq.." in range s"..seq_rst)
 					else
-						DLOG("standard_failure_detector: not counting incoming RST s"..seq.." beyond s"..options.seq_rst)
+						DLOG("standard_failure_detector: not counting incoming RST s"..seq.." beyond s"..seq_rst)
 					end
 				end
-			elseif not options.no_http_redirect and desync.l7payload=="http_reply" and desync.track.hostname then
+			elseif not arg.no_http_redirect and desync.l7payload=="http_reply" and desync.track.hostname then
 				local hdis = http_dissect_reply(desync.dis.payload)
 				if hdis and (hdis.code==302 or hdis.code==307) and hdis.headers.location and hdis.headers.location then
 					trigger = is_dpi_redirect(desync.track.hostname, hdis.headers.location.value)
@@ -123,13 +134,13 @@ function standard_failure_detector(desync, crec, options)
 		end
 	elseif desync.dis.udp then
 		if desync.outgoing then
-			if options.udp_out then
+			if udp_out then
-				local udp_in = options.udp_in or 0
+				local udp_in = udp_in or 0
-				trigger = desync.track.pcounter_orig>=options.udp_out and desync.track.pcounter_reply<=udp_in
+				trigger = desync.track.pcounter_orig>=udp_out and desync.track.pcounter_reply<=udp_in
 				if trigger then
 					crec.nocheck = true
 					if b_debug then
-						DLOG("standard_failure_detector: udp_out "..desync.track.pcounter_orig..">="..options.udp_out.." udp_in "..desync.track.pcounter_reply.."<="..udp_in)
+						DLOG("standard_failure_detector: udp_out "..desync.track.pcounter_orig..">="..udp_out.." udp_in "..desync.track.pcounter_reply.."<="..udp_in)
 					end
 				end
 			end
@@ -137,16 +148,6 @@ function standard_failure_detector(desync, crec, options)
 	end
 	return trigger
 end
--- prepare options table from args
-function standard_failure_detector_options(arg)
-	return {
-		seq_rst = tonumber(arg.rst) or 1,
-		retrans = tonumber(arg.retrans) or 3,
-		maxseq = tonumber(arg.seq) or 0x10000,
-		udp_in = tonumber(arg.udp_in) or 1,
-		udp_out = tonumber(arg.udp_out) or 3
-	}
-end
 
 -- circularily change strategy numbers when failure count reaches threshold ('fails')
 -- works with tcp only
@@ -154,14 +155,9 @@ end
 -- each orchestrated instance must have strategy=N arg, where N starts from 1 and increment without gaps
 -- if 'final' arg is present in an orchestrated instance it stops rotation
 -- arg: fails=N - failture count threshold. default is 3
--- arg: retrans=N - retrans count threshold. default is 3
--- arg: seq=<rseq> - if packet is beyond this relative sequence number treat this connection as successful. default is 64K
--- arg: rst=<rseq> - maximum relative sequence number to treat incoming RST as DPI reset. default is 1
 -- arg: time=<sec> - if last failure happened earlier than `maxtime` seconds ago - reset failure counter. default is 60.
 -- arg: reqhost - pass with no tampering if hostname is unavailable
--- arg: udp_out - >= outgoing udp packets. default is 3
+-- arg: detector - failure detector function name.
--- arg: udp_in - with <= incoming udp packets. default is 1
--- arg: detector - failure detector function name. '<func_name>_options' function converts parameters from arg to options table.
 -- test case: nfqws2 --qnum 200 --debug --lua-init=@zapret-lib.lua --lua-init=@zapret-auto.lua --in-range=-s1 --lua-desync=circular --lua-desync=argdebug:strategy=1 --lua-desync=argdebug:strategy=2
 function circular(ctx, desync)
 	local function count_strategies(hrec, plan)
@@ -226,20 +222,19 @@ function circular(ctx, desync)
 		local crec = automate_conn_record(desync)
 		local fails = tonumber(desync.arg.fails) or 3
 		local maxtime = tonumber(desync.arg.time) or 60
-		local failure_detector, failure_detector_getopts
+		local failure_detector
 		if desync.arg.detector then
 			if type(_G[desync.arg.detector])~="function" then
 				error("circular: invalid failure detector function '"..desync.arg.detector.."'")
 			end
 			failure_detector = _G[desync.arg.detector]
-			failure_detector_getopts = _G[desync.arg.detector.."_options"] or standard_failure_detector_options
 		else
 			failure_detector = standard_failure_detector
-			failure_detector_getopts = standard_failure_detector_options
 		end
-		if failure_detector(desync,crec,failure_detector_getopts(desync.arg)) then
+		if failure_detector(desync,crec,desync.arg) then
+			-- failure happened. count failures.
 			if automate_failure_counter(hrec, crec, fails, maxtime) then
-				-- circular strategy change
+				-- counter reaches threshold. circular strategy change
 				hrec.nstrategy = (hrec.nstrategy % hrec.ctstrategy) + 1
 				DLOG("circular: rotate strategy to "..hrec.nstrategy)
 				if hrec.nstrategy == hrec.final then