AI and manual fixes

docs/changes.txt

@@ -328,3 +328,5 @@ v0.9.4.3
 * blockcheck2: use --wf-raw-filter in Windows instead of --ipset to limit target IP addresses
 * github, builder_linux: lua 5.5.1
 * nfqws2: negate SSID/NLM filters
+* nfqws2: desync function can explicitly return nil as a synonym of VERDICT_PASS
+* zapret-lub: luaexec now passes returned verdict code

docs/manual.en.md

@@ -2493,6 +2493,8 @@ The code can address the `desync` table-it is temporarily assigned to a global v
 
 Example: `--lua-desync=luaexec:code="desync.rnd=brandom(math.random(5,10))"`
 
+Verdict can be returned using "return" statement.
+
 ### pass
 
 ```

docs/manual.md

@@ -2653,6 +2653,8 @@ function luaexec(ctx, desync)
 
 Пример : `--lua-desync=luaexec:code="desync.rnd=brandom(math.random(5,10))"`
 
+Функция может возвращать вердикт через return.
+
 ### pass
 
 ```

lua/zapret-auto.lua

@@ -420,7 +420,6 @@ function cond_lua(desync)
 		_G[fname], err = load(desync.arg.cond_code, fname)
 		if not _G[fname] then
 			error(err)
-			return
 		end
 	end
 	-- allow dynamic cond_code to access desync
@@ -463,7 +462,7 @@ function condition(ctx, desync)
 	return replay_execution_plan(desync)
 end
 -- execute further desync instances.
--- each instance may have "cond" and "cond_neg" args.
+-- each instance must have "cond" arg and may optionally have "cond_neg" arg.
 -- "cond" - condition function.  "neg" - invert condition function result
 -- arg: instances - how many instances execute conditionally. all if not defined
 function per_instance_condition(ctx, desync)

lua/zapret-lib.lua

@@ -29,10 +29,12 @@ function luaexec(ctx, desync)
 	end
 	-- allow dynamic code to access desync
 	_G.desync = desync
-	local res, err = pcall(_G[fname])
+	local res, ret = pcall(_G[fname])
 	_G.desync = nil
 	if not res then
-		error(err);
+		error(ret)
+	else
+		return ret and ret or VERDICT_PASS -- older nfqws2 failed if desync function returned explicit nil
 	end
 end
 
@@ -1607,7 +1609,11 @@ function tls_client_hello_mod(tls, options)
 	end
 	local idx_sni
 	if options.sni_snt or options.sni_del_ext or options.sni_del or options.sni_first or options.sni_last then
+		if tdis.handshake[TLS_HANDSHAKE_TYPE_CLIENT].dis.ext then
 			idx_sni = array_field_search(tdis.handshake[TLS_HANDSHAKE_TYPE_CLIENT].dis.ext, "type", TLS_EXT_SERVER_NAME)
+		else
+			tdis.handshake[TLS_HANDSHAKE_TYPE_CLIENT].dis.ext={}
+		end
 		if not idx_sni then
 			DLOG("tls_client_hello_mod: no SNI extension. adding")
 			table.insert(tdis.handshake[TLS_HANDSHAKE_TYPE_CLIENT].dis.ext, 1, { type = TLS_EXT_SERVER_NAME, dis = { list = {} } } )
@@ -2441,7 +2447,7 @@ function tls_dissect_handshake(handshake, partialOK)
 		handshake.dis = { type = typ , ver = u16(handshake.data, 5), name = tostring(TLS_HANDSHAKE_TYPE_NAMES[typ]) }
 
 		-- random
-		if hlen<36 then return partialOK end
+		if hlen<38 then return partialOK end
 		handshake.dis.random = string.sub(handshake.data, 7, 38)
 
 		-- session_id
@@ -2649,8 +2655,10 @@ function tls_reconstruct_handshake(handshake)
 					end
 					exts = exts .. bu16(handshake.dis.ext[i].type) .. bu16(#handshake.dis.ext[i].data) .. handshake.dis.ext[i].data
 				end
-			end
 				handshake.data = bu8(handshake.type) .. bu24(#header + 2 + #exts) .. header .. bu16(#exts) .. exts
+			else
+				handshake.data = bu8(handshake.type) .. bu24(#header) .. header
+			end
 		end
 	end
 
@@ -2701,11 +2709,10 @@ function tls_reconstruct(tdis)
 			if not rec.data then return nil end
 		end
 		tls = barray(tdis.rec, function(a) return (#a.data > 0) and (bu8(a.type) .. bu16(a.ver) .. bu16(#a.data) .. a.data) or "" end)
-	elseif tdis.handshake and #tdis.handshake==1 then
-		-- without record layer
-		for k,handshake in pairs(tdis.handshake) do
-			tls = handshake.data
-			break
+	elseif tdis.handshake then
+		local i = next(tdis.handshake)
+		if i~=nil then
+			tls = tdis.handshake[i].data
 		end
 	end
 

nfq2/conntrack.c

@@ -395,15 +395,6 @@ bool ReasmInit(t_reassemble *reasm, size_t size_requested, uint32_t seq_start)
 	reasm->seq = seq_start;
 	return true;
 }
-bool ReasmResize(t_reassemble *reasm, size_t new_size)
-{
-	uint8_t *p = realloc(reasm->packet, new_size);
-	if (!p) return false;
-	reasm->packet = p;
-	reasm->size = new_size;
-	if (reasm->size_present > new_size) reasm->size_present = new_size;
-	return true;
-}
 #define REASM_MAX_NEG 0x100000
 bool ReasmFeed(t_reassemble *reasm, uint32_t seq, const void *payload, size_t len)
 {

nfq2/darkmagic.c

@@ -377,8 +377,9 @@ bool proto_check_ipv4(const uint8_t *data, size_t len)
 {
 	if (len < sizeof(struct ip)) return false;
 	if (((struct ip*)data)->ip_v!=4) return false;
+	uint16_t iplen = ntohs(((struct ip*)data)->ip_len);
 	uint8_t off = ((struct ip*)data)->ip_hl << 2;
-	return off>=sizeof(struct ip) && len>=off;
+	return off>=sizeof(struct ip) && iplen>=off && len>=off;
 }
 bool proto_check_ipv4_payload(const uint8_t *data, size_t len)
 {
@@ -559,7 +560,7 @@ void proto_dissect_l3l4(const uint8_t *data, size_t len, struct dissect *dis, bo
 	dis->data_pkt = data;
 	dis->len_pkt = len;
 
-	uint16_t iplen;
+	size_t iplen;
 
 	if (proto_check_ipv4(data, len) && (no_payload_check || proto_check_ipv4_payload(data, len)))
 	{

nfq2/desync.c

@@ -814,7 +814,12 @@ static bool desync_get_result(uint8_t *verdict)
 		DLOG_ERR("desync function returned more than one result : %d\n", rescount);
 		goto err;
 	}
+	// absence of the return value or nil mean VERDICT_PASS
 	if (rescount)
+	{
+		if (lua_isnil(params.L, -1))
+			*verdict = VERDICT_PASS;
+		else
 		{
 			if (!lua_isinteger(params.L, -1))
 			{
@@ -829,6 +834,7 @@ static bool desync_get_result(uint8_t *verdict)
 			}
 			*verdict = (uint8_t)lv;
 		}
+	}
 	else
 		*verdict = VERDICT_PASS; // default result if function returns nothing
 	lua_pop(params.L, rescount);

nfq2/nfqws.c

@@ -594,8 +594,9 @@ static int nfq_main(void)
 		DLOG_ERR("recv: recv=%zd errno %d\n", rd, e);
 		errno = e;
 		DLOG_PERROR("recv");
+		errno = e;
 		// do not fail on ENOBUFS
-	} while (e == ENOBUFS);
+	} while (errno == ENOBUFS);
 
 err:
 	res=1;