From fd1eac2ef11eff525a82868c17d3692646958fc3 Mon Sep 17 00:00:00 2001
From: bol-van <none@none.none>
Date: Fri, 5 Dec 2025 22:31:51 +0300
Subject: [PATCH] zapret-lib: fix seq number substraction

---
 lua/zapret-antidpi.lua |  2 +-
 lua/zapret-lib.lua     |  9 +++++++--
 lua/zapret-tests.lua   | 26 +++++++++++++++++++++++++-
 3 files changed, 33 insertions(+), 4 deletions(-)

diff --git a/lua/zapret-antidpi.lua b/lua/zapret-antidpi.lua
index c367004..1e63496 100644
--- a/lua/zapret-antidpi.lua
+++ b/lua/zapret-antidpi.lua
@@ -290,7 +290,7 @@ end
 -- nfqws1 : "--dpi-desync=syndata"
 -- standard args : fooling, rawsend, reconstruct, ipfrag
 -- arg : blob=<blob> - fake payload. must fit to single packet. no segmentation possible. default - 16 zero bytes.
--- arg : tls_mod=<list> - comma separated list of tls mods : rnd,rndsni,sni=<str>,dupsid,padencap
+-- arg : tls_mod=<list> - comma separated list of tls mods : rnd,rndsni,sni=<str>
 function syndata(ctx, desync)
 	if desync.dis.tcp then
 		if bitand(desync.dis.tcp.th_flags, TH_SYN + TH_ACK)==TH_SYN then
diff --git a/lua/zapret-lib.lua b/lua/zapret-lib.lua
index fb033b1..ea4945e 100644
--- a/lua/zapret-lib.lua
+++ b/lua/zapret-lib.lua
@@ -85,7 +85,7 @@ function apply_execution_plan(desync, plan)
 	desync.arg = deepcopy(plan.arg)
 	apply_arg_prefix(desync.arg)
 end
--- produce resulting verdict from 2 verdict
+-- produce resulting verdict from 2 verdicts
 function verdict_aggregate(v1, v2)
 	local v
 	v1 = v1 or VERDICT_PASS
@@ -142,7 +142,7 @@ function pos_get(desync, mode)
 		elseif mode=='b' then
 			return desync.outgoing and desync.track.pbcounter_orig or desync.track.pbcounter_reply
 		elseif mode=='s' and desync.track.tcp then
-			return desync.outgoing and (desync.track.tcp.seq - desync.track.tcp.seq0) or (desync.track.tcp.ack - desync.track.tcp.ack0)
+			return desync.outgoing and u32add(desync.track.tcp.seq, -desync.track.tcp.seq0) or u32add(desync.track.tcp.ack, -desync.track.tcp.ack0)
 		end
 	end
 	return 0
@@ -1032,6 +1032,11 @@ function genhost(len, template)
 	end
 end
 
+-- return hostname if present or ip address in text form otherwise
+function host_or_ip(desync)
+	return desync.hostname or (desync.dis.ip and ntop(desync.dis.ip) or desync.dis.ip6 and ntop(desync.dis.ip6))
+end
+
 function is_absolute_path(path)
 	if string.sub(path,1,1)=='/' then return true end
 	local un = uname()
diff --git a/lua/zapret-tests.lua b/lua/zapret-tests.lua
index 7224906..6a549a2 100644
--- a/lua/zapret-tests.lua
+++ b/lua/zapret-tests.lua
@@ -299,8 +299,32 @@ function test_bit()
 	test_assert(v2==v3)
 end
 
+function test_ux()
+	local v1, v2, v3, usum, sum
+	for k,test in pairs({
+		{ add=u8add, fname="u8add", max = 0xFF },
+		{ add=u16add, fname="u16add", max = 0xFFFF },
+		{ add=u24add, fname="u24add", max = 0xFFFFFF },
+		{ add=u32add, fname="u32add", max = 0xFFFFFFFF }
+	}) do
+		io.write(test.fname.." : ")
+		for i=1,1000 do
+			v1=math.random(-test.max,test.max)
+			v2=math.random(-test.max,test.max)
+			v3=math.random(-test.max,test.max)
+			usum = test.add(v1,v2,v3)
+			sum = bitand(v1+v2+v3,test.max)
+			if sum~=usum then
+				print("FAIL")
+			end
+			test_assert(sum==usum)
+		end
+		print("OK")
+	end
+end
+
 function test_bin(...)
-	test_run({test_ub, test_bit},...)
+	test_run({test_ub, test_bit, test_ux},...)
 end