blockcheck.sh

@@ -906,17 +906,16 @@ pktws_check_domain_http_bypass_()
 				[ "$SCANLEVEL" = quick ] && return
 			}			
 		done
-
-		s="http_iana_org.bin"
-		[ "$sec" = 1 ] && s="tls_clienthello_iana_org.bin"
-		for desync in syndata syndata,split2 syndata,disorder2 syndata,split2 syndata,disorder2 ; do
-			pktws_curl_test_update_vary $1 $2 $3 $desync $e && [ "$SCANLEVEL" = quick ] && return
-			pktws_curl_test_update_vary $1 $2 $3 $desync --dpi-desync-fake-syndata="$ZAPRET_BASE/files/fake/$s" $e && [ "$SCANLEVEL" = quick ] && return
-		done
-
 		# do not do wssize test for http. it's useless
 		[ "$sec" = 1 ] || break
 	done
+
+	s="http_iana_org.bin"
+	[ "$sec" = 1 ] && s="tls_clienthello_iana_org.bin"
+	for desync in syndata syndata,split2 syndata,disorder2 syndata,split2 syndata,disorder2 ; do
+		pktws_curl_test_update_vary $1 $2 $3 $desync && [ "$SCANLEVEL" = quick ] && return
+		pktws_curl_test_update_vary $1 $2 $3 $desync --dpi-desync-fake-syndata="$ZAPRET_BASE/files/fake/$s" && [ "$SCANLEVEL" = quick ] && return
+	done
 }
 pktws_check_domain_http_bypass()
 {

nfq/desync.c

@@ -321,60 +321,40 @@ static void reasm_orig_fin(t_ctrack *ctrack)
 }
 
 
-static uint8_t ct_new_postnat_fix(const t_ctrack *ctrack, struct ip *ip, struct ip6_hdr *ip6, uint8_t proto, struct udphdr *udp, struct tcphdr *tcp, size_t *len_pkt)
+static packet_process_result ct_new_postnat_fix(const t_ctrack *ctrack, struct ip *ip, packet_process_result res)
 {
 #ifdef __linux__
 	// if used in postnat chain, dropping initial packet will cause conntrack connection teardown
 	// so we need to workaround this.
-	// we can't use low ttl because TCP/IP stack listens to ttl expired ICMPs and notify socket
+	// we can't use low ttl for UDP because TCP/IP stack listens to ttl expired ICMPs and notify socket
-	// we also can't use fooling because DPI would accept fooled packets
+	// we also can't use TCP fooling because DPI would accept fooled packets
-	if (ctrack && ctrack->pcounter_orig==1)
+	if (ip && ctrack && ctrack->pcounter_orig==1)
 	{
-		DLOG("applying linux postnat conntrack workaround\n")
+		// routers will drop IP frames with invalid checksum
-		if (proto==IPPROTO_UDP && udp && len_pkt)
+		if (ip->ip_p==IPPROTO_TCP)
 		{
-			// make malformed udp packet with zero length and invalid checksum
+			// linux recalc ip checksum in tcp
-			udp->len = 0; // invalid length. must be >=8
+			// need another limiter
-			udp_fix_checksum(udp,sizeof(struct udphdr),ip,ip6);
+			ip->ip_ttl=1;
-			udp->check ^= htons(0xBEAF);
-			// truncate packet
-			*len_pkt = (uint8_t*)udp - (ip ? (uint8_t*)ip : (uint8_t*)ip6) + sizeof(struct udphdr);
-			if (ip)
-			{
-				ip->ip_len = htons((uint16_t)*len_pkt);
-				ip4_fix_checksum(ip);
-			}
-			else if (ip6)
-				ip6->ip6_ctlun.ip6_un1.ip6_un1_plen = (uint16_t)htons(sizeof(struct udphdr));
 		}
-		else if (proto==IPPROTO_TCP && tcp)
+		else
-		{
+			ip->ip_sum ^= htons(0xBEAF);
-			// only SYN here is expected
+		
-			// make flags invalid and also corrupt checksum
+		return res==frag ? modfrag : modify;
-			tcp->th_flags = 0;
-		}
-		if (ip)	ip->ip_sum ^= htons(0xBEAF);
-		return VERDICT_MODIFY | VERDICT_NOCSUM;
 	}
+	else
 #endif
-	return VERDICT_DROP;
+	// ipv6 does not have checksum
+    	// consider we are free of NAT in ipv6 case. just drop
+	// BSDs also do not need this
+	return drop;
 }
 
-static uint8_t ct_new_postnat_fix_tcp(const t_ctrack *ctrack, struct ip *ip, struct ip6_hdr *ip6, struct tcphdr *tcphdr)
-{
-	return ct_new_postnat_fix(ctrack,ip,ip6,IPPROTO_TCP,NULL,tcphdr,NULL);
-}
-static uint8_t ct_new_postnat_fix_udp(const t_ctrack *ctrack, struct ip *ip, struct ip6_hdr *ip6, struct udphdr *udphdr, size_t *len_pkt)
-{
-	return ct_new_postnat_fix(ctrack,ip,ip6,IPPROTO_UDP,udphdr,NULL,len_pkt);
-}
-
-
 
 // result : true - drop original packet, false = dont drop
-uint8_t dpi_desync_tcp_packet(uint32_t fwmark, const char *ifout, uint8_t *data_pkt, size_t *len_pkt, struct ip *ip, struct ip6_hdr *ip6hdr, struct tcphdr *tcphdr, size_t len_tcp, uint8_t *data_payload, size_t len_payload)
+packet_process_result dpi_desync_tcp_packet(uint32_t fwmark, const char *ifout, uint8_t *data_pkt, size_t len_pkt, struct ip *ip, struct ip6_hdr *ip6hdr, struct tcphdr *tcphdr, size_t len_tcp, uint8_t *data_payload, size_t len_payload)
 {
-	uint8_t res=VERDICT_PASS;
+	packet_process_result res=pass;
 	t_ctrack *ctrack=NULL;
 	bool bReverse=false;
 
@@ -397,7 +377,7 @@ uint8_t dpi_desync_tcp_packet(uint32_t fwmark, const char *ifout, uint8_t *data_
 	if (params.wsize && tcp_synack_segment(tcphdr))
 	{
 		tcp_rewrite_winsize(tcphdr, params.wsize, params.wscale);
-		res=VERDICT_MODIFY;
+		res=modify;
 	}
 	
 	if (bReverse)
@@ -470,7 +450,7 @@ uint8_t dpi_desync_tcp_packet(uint32_t fwmark, const char *ifout, uint8_t *data_
 			{
 				if (params.wssize_cutoff) DLOG("wssize-cutoff not reached (mode %c): %llu/%u\n", params.wssize_cutoff_mode, (unsigned long long)cutoff_get_limit(ctrack,params.wssize_cutoff_mode), params.wssize_cutoff);
 				tcp_rewrite_winsize(tcphdr, params.wssize, params.wsscale);
-				res=VERDICT_MODIFY;
+				res=modify;
 			}
 		}
 		else
@@ -528,7 +508,7 @@ uint8_t dpi_desync_tcp_packet(uint32_t fwmark, const char *ifout, uint8_t *data_
 				if (!rawsend_rep((struct sockaddr *)&dst, desync_fwmark, ifout , pkt1, pkt1_len))
 					return res;
 
-				res = ct_new_postnat_fix_tcp(ctrack, ip, ip6hdr, tcphdr);
+				res = ct_new_postnat_fix(ctrack, ip, drop);
 				break;
 		}
 		// can do nothing else with SYN packet
@@ -683,14 +663,14 @@ uint8_t dpi_desync_tcp_packet(uint32_t fwmark, const char *ifout, uint8_t *data_
 			{
 				DLOG("modifying Host: => %c%c%c%c:\n", params.hostspell[0], params.hostspell[1], params.hostspell[2], params.hostspell[3])
 				memcpy(phost + 2, params.hostspell, 4);
-				res=VERDICT_MODIFY;
+				res=modify;
 			}
 			if (params.domcase)
 			{
 				DLOG("mixing domain case\n");
 				for (p = phost+7; p < (data_payload + len_payload) && *p != '\r' && *p != '\n'; p++)
 					*p = (((size_t)p) & 1) ? tolower(*p) : toupper(*p);
-				res=VERDICT_MODIFY;
+				res=modify;
 			}
 			uint8_t *pua;
 			if (params.hostnospace &&
@@ -708,7 +688,7 @@ uint8_t dpi_desync_tcp_packet(uint32_t fwmark, const char *ifout, uint8_t *data_
 					memmove(pua + 1, pua, phost - pua + 7);
 					*pua = ' ';
 				}
-				res=VERDICT_MODIFY;
+				res=modify;
 			}
 		}
 
@@ -776,7 +756,7 @@ uint8_t dpi_desync_tcp_packet(uint32_t fwmark, const char *ifout, uint8_t *data_
 					if (!rawsend((struct sockaddr *)&dst, desync_fwmark, ifout , pkt1, pkt1_len))
 						return res;
 					// this mode is final, no other options available
-					return VERDICT_DROP;
+					return drop;
 				}
 				desync_mode = params.desync_mode2;
 		}
@@ -789,23 +769,23 @@ uint8_t dpi_desync_tcp_packet(uint32_t fwmark, const char *ifout, uint8_t *data_
 			{
 					if (params.desync_retrans)
 					{
-						DLOG("dropping original packet to force retransmission. len=%zu len_payload=%zu\n", *len_pkt, len_payload)
+						DLOG("dropping original packet to force retransmission. len=%zu len_payload=%zu\n", len_pkt, len_payload)
 					}
 					else
 					{
-						DLOG("reinjecting original packet. len=%zu len_payload=%zu\n", *len_pkt, len_payload)
+						DLOG("reinjecting original packet. len=%zu len_payload=%zu\n", len_pkt, len_payload)
 						#ifdef __FreeBSD__
 						// FreeBSD tend to pass ipv6 frames with wrong checksum
-						if ((res & VERDICT_MASK)==VERDICT_MODIFY || ip6hdr)
+						if (res==modify || ip6hdr)
 						#else
 						// if original packet was tampered earlier it needs checksum fixed
-						if ((res & VERDICT_MASK)==VERDICT_MODIFY)
+						if (res==modify)
 						#endif
 							tcp_fix_checksum(tcphdr,len_tcp,ip,ip6hdr);
-						if (!rawsend((struct sockaddr *)&dst, desync_fwmark, ifout , data_pkt, *len_pkt))
+						if (!rawsend((struct sockaddr *)&dst, desync_fwmark, ifout , data_pkt, len_pkt))
 							return res;
 					}
-					return VERDICT_DROP;
+					return drop;
 			}
 			desync_mode = params.desync_mode2;
 		}
@@ -865,7 +845,7 @@ uint8_t dpi_desync_tcp_packet(uint32_t fwmark, const char *ifout, uint8_t *data_
 							return res;
 					}
 
-					return VERDICT_DROP;
+					return drop;
 				}
 				break;
 			case DESYNC_SPLIT:
@@ -918,17 +898,17 @@ uint8_t dpi_desync_tcp_packet(uint32_t fwmark, const char *ifout, uint8_t *data_
 							return res;
 					}
 
-					return VERDICT_DROP;
+					return drop;
 				}
 				break;
 			case DESYNC_IPFRAG2:
 				{
 					#ifdef __FreeBSD__
 					// FreeBSD tend to pass ipv6 frames with wrong checksum
-					if ((res & VERDICT_MASK)==VERDICT_MODIFY || ip6hdr)
+					if (res==modify || ip6hdr)
 					#else
 					// if original packet was tampered earlier it needs checksum fixed
-					if ((res & VERDICT_MASK)==VERDICT_MODIFY)
+					if (res==modify)
 					#endif
 						tcp_fix_checksum(tcphdr,len_tcp,ip,ip6hdr);
 
@@ -944,14 +924,14 @@ uint8_t dpi_desync_tcp_packet(uint32_t fwmark, const char *ifout, uint8_t *data_
 					if (ip6hdr && (fooling_orig==FOOL_HOPBYHOP || fooling_orig==FOOL_DESTOPT))
 					{
 						pkt_orig_len = sizeof(pkt3);
-						if (!ip6_insert_simple_hdr(fooling_orig==FOOL_HOPBYHOP ? IPPROTO_HOPOPTS : IPPROTO_DSTOPTS, data_pkt, *len_pkt, pkt3, &pkt_orig_len))
+						if (!ip6_insert_simple_hdr(fooling_orig==FOOL_HOPBYHOP ? IPPROTO_HOPOPTS : IPPROTO_DSTOPTS, data_pkt, len_pkt, pkt3, &pkt_orig_len))
 							return res;
 						pkt_orig = pkt3;
 					}
 					else
 					{
 						pkt_orig = data_pkt;
-						pkt_orig_len = *len_pkt;
+						pkt_orig_len = len_pkt;
 					}
 
 					if (!ip_frag(pkt_orig, pkt_orig_len, ipfrag_pos, ident, pkt1, &pkt1_len, pkt2, &pkt2_len))
@@ -967,7 +947,7 @@ uint8_t dpi_desync_tcp_packet(uint32_t fwmark, const char *ifout, uint8_t *data_
 					if (!rawsend((struct sockaddr *)&dst, desync_fwmark, ifout , pkt1, pkt1_len))
 						return res;
 
-					return VERDICT_DROP;
+					return frag;
 				}
 		}
 	
@@ -978,9 +958,9 @@ uint8_t dpi_desync_tcp_packet(uint32_t fwmark, const char *ifout, uint8_t *data_
 
 
 
-uint8_t dpi_desync_udp_packet(uint32_t fwmark, const char *ifout, uint8_t *data_pkt, size_t *len_pkt, struct ip *ip, struct ip6_hdr *ip6hdr, struct udphdr *udphdr, uint8_t *data_payload, size_t len_payload)
+packet_process_result dpi_desync_udp_packet(uint32_t fwmark, const char *ifout, uint8_t *data_pkt, size_t len_pkt, struct ip *ip, struct ip6_hdr *ip6hdr, struct udphdr *udphdr, uint8_t *data_payload, size_t len_payload)
 {
-	uint8_t res=VERDICT_PASS;
+	packet_process_result res=pass;
 	t_ctrack *ctrack=NULL;
 	bool bReverse=false;
 
@@ -1176,7 +1156,7 @@ uint8_t dpi_desync_udp_packet(uint32_t fwmark, const char *ifout, uint8_t *data_
 					if (!rawsend((struct sockaddr *)&dst, desync_fwmark, ifout , pkt1, pkt1_len))
 						return res;
 					// this mode is final, no other options available
-					return ct_new_postnat_fix_udp(ctrack, ip, ip6hdr, udphdr, len_pkt);
+					return ct_new_postnat_fix(ctrack, ip, drop);
 				}
 				desync_mode = params.desync_mode2;
 				break;
@@ -1186,18 +1166,18 @@ uint8_t dpi_desync_udp_packet(uint32_t fwmark, const char *ifout, uint8_t *data_
 		{
 			if (params.desync_mode2==DESYNC_NONE || !desync_valid_second_stage_udp(params.desync_mode2))
 			{
-				DLOG("reinjecting original packet. len=%zu len_payload=%zu\n", *len_pkt, len_payload)
+				DLOG("reinjecting original packet. len=%zu len_payload=%zu\n", len_pkt, len_payload)
 				#ifdef __FreeBSD__
 				// FreeBSD tend to pass ipv6 frames with wrong checksum
-				if ((res & VERDICT_MASK)==VERDICT_MODIFY || ip6hdr)
+				if (res==modify || ip6hdr)
 				#else
 				// if original packet was tampered earlier it needs checksum fixed
-				if ((res & VERDICT_MASK)==VERDICT_MODIFY)
+				if (res==modify)
 				#endif
 					udp_fix_checksum(udphdr,sizeof(struct udphdr)+len_payload,ip,ip6hdr);
-				if (!rawsend((struct sockaddr *)&dst, desync_fwmark, ifout , data_pkt, *len_pkt))
+				if (!rawsend((struct sockaddr *)&dst, desync_fwmark, ifout , data_pkt, len_pkt))
 					return res;
-				return ct_new_postnat_fix_udp(ctrack, ip, ip6hdr, udphdr, len_pkt);
+				return ct_new_postnat_fix(ctrack, ip, drop);
 			}
 			desync_mode = params.desync_mode2;
 		}
@@ -1214,7 +1194,7 @@ uint8_t dpi_desync_udp_packet(uint32_t fwmark, const char *ifout, uint8_t *data_
 				DLOG("resending original packet with increased by %d length\n", params.udplen_increment);
 				if (!rawsend((struct sockaddr *)&dst, desync_fwmark, ifout , pkt1, pkt1_len))
 					return res;
-				return ct_new_postnat_fix_udp(ctrack, ip, ip6hdr, udphdr, len_pkt);
+				return ct_new_postnat_fix(ctrack, ip, drop);
 			case DESYNC_TAMPER:
 				if (IsDhtD1(data_payload,len_payload))
 				{
@@ -1239,7 +1219,7 @@ uint8_t dpi_desync_udp_packet(uint32_t fwmark, const char *ifout, uint8_t *data_
 					DLOG("resending tampered DHT\n");
 					if (!rawsend((struct sockaddr *)&dst, desync_fwmark, ifout , pkt1, pkt1_len))
 						return res;
-					return ct_new_postnat_fix_udp(ctrack, ip, ip6hdr, udphdr, len_pkt);
+					return ct_new_postnat_fix(ctrack, ip, drop);
 				}
 				else
 				{
@@ -1251,10 +1231,10 @@ uint8_t dpi_desync_udp_packet(uint32_t fwmark, const char *ifout, uint8_t *data_
 
 					#ifdef __FreeBSD__
 					// FreeBSD tend to pass ipv6 frames with wrong checksum
-					if ((res & VERDICT_MASK)==VERDICT_MODIFY || ip6hdr)
+					if (res==modify || ip6hdr)
 					#else
 					// if original packet was tampered earlier it needs checksum fixed
-					if ((res & VERDICT_MASK)==VERDICT_MODIFY)
+					if (res==modify)
 					#endif
 						udp_fix_checksum(udphdr,sizeof(struct udphdr)+len_payload,ip,ip6hdr);
 
@@ -1272,14 +1252,14 @@ uint8_t dpi_desync_udp_packet(uint32_t fwmark, const char *ifout, uint8_t *data_
 					if (ip6hdr && (fooling_orig==FOOL_HOPBYHOP || fooling_orig==FOOL_DESTOPT))
 					{
 						pkt_orig_len = sizeof(pkt3);
-						if (!ip6_insert_simple_hdr(fooling_orig==FOOL_HOPBYHOP ? IPPROTO_HOPOPTS : IPPROTO_DSTOPTS, data_pkt, *len_pkt, pkt3, &pkt_orig_len))
+						if (!ip6_insert_simple_hdr(fooling_orig==FOOL_HOPBYHOP ? IPPROTO_HOPOPTS : IPPROTO_DSTOPTS, data_pkt, len_pkt, pkt3, &pkt_orig_len))
 							return res;
 						pkt_orig = pkt3;
 					}
 					else
 					{
 						pkt_orig = data_pkt;
-						pkt_orig_len = *len_pkt;
+						pkt_orig_len = len_pkt;
 					}
 
 					if (!ip_frag(pkt_orig, pkt_orig_len, ipfrag_pos, ident, pkt1, &pkt1_len, pkt2, &pkt2_len))
@@ -1295,7 +1275,7 @@ uint8_t dpi_desync_udp_packet(uint32_t fwmark, const char *ifout, uint8_t *data_
 					if (!rawsend((struct sockaddr *)&dst, desync_fwmark, ifout , pkt1, pkt1_len))
 						return res;
 
-					return ct_new_postnat_fix_udp(ctrack, ip, ip6hdr, udphdr, len_pkt);
+					return ct_new_postnat_fix(ctrack, ip, frag);
 				}
 		}
 

nfq/desync.h

@@ -51,5 +51,5 @@ bool desync_valid_second_stage_tcp(enum dpi_desync_mode mode);
 bool desync_valid_second_stage_udp(enum dpi_desync_mode mode);
 
 void desync_init(void);
-uint8_t dpi_desync_tcp_packet(uint32_t fwmark, const char *ifout, uint8_t *data_pkt, size_t *len_pkt, struct ip *ip, struct ip6_hdr *ip6hdr, struct tcphdr *tcphdr, size_t len_tcp, uint8_t *data_payload, size_t len_payload);
+packet_process_result dpi_desync_tcp_packet(uint32_t fwmark, const char *ifout, uint8_t *data_pkt, size_t len_pkt, struct ip *ip, struct ip6_hdr *ip6hdr, struct tcphdr *tcphdr, size_t len_tcp, uint8_t *data_payload, size_t len_payload);
-uint8_t dpi_desync_udp_packet(uint32_t fwmark, const char *ifout, uint8_t *data_pkt, size_t *len_pkt, struct ip *ip, struct ip6_hdr *ip6hdr, struct udphdr *udphdr, uint8_t *data_payload, size_t len_payload);
+packet_process_result dpi_desync_udp_packet(uint32_t fwmark, const char *ifout, uint8_t *data_pkt, size_t len_pkt, struct ip *ip, struct ip6_hdr *ip6hdr, struct udphdr *udphdr, uint8_t *data_payload, size_t len_payload);

nfq/nfqws.c

@@ -80,15 +80,15 @@ static void onusr2(int sig)
 
 
 
-static uint8_t processPacketData(uint32_t *mark, const char *ifout, uint8_t *data_pkt, size_t *len_pkt)
+static packet_process_result processPacketData(uint32_t *mark, const char *ifout, uint8_t *data_pkt, size_t len_pkt)
 {
 	struct ip *ip = NULL;
 	struct ip6_hdr *ip6hdr = NULL;
 	struct tcphdr *tcphdr = NULL;
 	struct udphdr *udphdr = NULL;
-	size_t len = *len_pkt, len_with_th;
+	size_t len = len_pkt, len_with_th;
 	uint8_t *data = data_pkt;
-	uint8_t res = VERDICT_PASS;
+	packet_process_result res = pass;
 	uint8_t proto;
 
 #ifdef __linux__
@@ -146,9 +146,9 @@ static uint8_t processPacketData(uint32_t *mark, const char *ifout, uint8_t *dat
 		// ipv6 packets were with incorrect checksum
 #ifdef __FreeBSD__
 		// FreeBSD tend to pass ipv6 frames with wrong checksum
-		if (!(res & VERDICT_NOCSUM) && ((res & VERDICT_MASK)==VERDICT_MODIFY || ip6hdr && (res & VERDICT_MASK)==VERDICT_PASS))
+		if (res==modify || res!=frag && res!=modfrag && ip6hdr)
 #else
-		if (!(res & VERDICT_NOCSUM) && (res & VERDICT_MASK)==VERDICT_MODIFY)
+		if (res==modify)
 #endif
 			tcp_fix_checksum(tcphdr,len_with_th,ip,ip6hdr);
 	}
@@ -169,9 +169,9 @@ static uint8_t processPacketData(uint32_t *mark, const char *ifout, uint8_t *dat
 		res = dpi_desync_udp_packet(*mark, ifout, data_pkt, len_pkt, ip, ip6hdr, udphdr, data, len);
 #ifdef __FreeBSD__
 		// FreeBSD tend to pass ipv6 frames with wrong checksum
-		if (!(res & VERDICT_NOCSUM) && ((res & VERDICT_MASK)==VERDICT_MODIFY || ip6hdr && (res & VERDICT_MASK)==VERDICT_PASS))
+		if (res==modify || res!=frag && res!=modfrag && ip6hdr)
 #else
-		if (!(res & VERDICT_NOCSUM) && (res & VERDICT_MASK)==VERDICT_MODIFY)
+		if (res==modify)
 #endif
 			udp_fix_checksum(udphdr,len_with_th,ip,ip6hdr);
 	}
@@ -187,8 +187,8 @@ static uint8_t processPacketData(uint32_t *mark, const char *ifout, uint8_t *dat
 #ifdef __linux__
 static int nfq_cb(struct nfq_q_handle *qh, struct nfgenmsg *nfmsg, struct nfq_data *nfa, void *cookie)
 {
-	int id, ilen;
+	int id;
-	size_t len;
+	int len;
 	struct nfqnl_msg_packet_hdr *ph;
 	uint8_t *data;
 	uint32_t ifidx;
@@ -198,7 +198,7 @@ static int nfq_cb(struct nfq_q_handle *qh, struct nfgenmsg *nfmsg, struct nfq_da
 	id = ph ? ntohl(ph->packet_id) : 0;
 
 	uint32_t mark = nfq_get_nfmark(nfa);
-	ilen = nfq_get_payload(nfa, &data);
+	len = nfq_get_payload(nfa, &data);
 
 	*ifout=0;
 	if (params.bind_fix4 || params.bind_fix6)
@@ -206,21 +206,21 @@ static int nfq_cb(struct nfq_q_handle *qh, struct nfgenmsg *nfmsg, struct nfq_da
 		ifidx = nfq_get_outdev(nfa);
 		if (ifidx) if_indextoname(ifidx,ifout);
 
-		DLOG("packet: id=%d len=%d mark=%08X ifout=%s(%u)\n", id, ilen, mark, ifout, ifidx)
+		DLOG("packet: id=%d len=%d ifout=%s(%u)\n", id, len, ifout, ifidx)
 	}
 	else
 		// save some syscalls
-		DLOG("packet: id=%d len=%d mark=%08X\n", id, ilen, mark)
+		DLOG("packet: id=%d len=%d\n", id, len)
-	if (ilen >= 0)
+	if (len >= 0)
 	{
-		len = ilen;
+		switch (processPacketData(&mark, ifout, data, len))
-		uint8_t res = processPacketData(&mark, ifout, data, &len);
-		switch(res & VERDICT_MASK)
 		{
-		case VERDICT_MODIFY:
+		case modify: 
-			DLOG("packet: id=%d pass modified. len=%zu\n", id, len);
+		case modfrag:
-			return nfq_set_verdict2(qh, id, NF_ACCEPT, mark, (uint32_t)len, data);
+			DLOG("packet: id=%d pass modified\n", id);
-		case VERDICT_DROP:
+			return nfq_set_verdict2(qh, id, NF_ACCEPT, mark, len, data);
+		case drop:
+		case frag:
 			DLOG("packet: id=%d drop\n", id);
 			return nfq_set_verdict2(qh, id, NF_DROP, mark, 0, NULL);
 		}
@@ -343,6 +343,7 @@ static int dvt_main(void)
 	unsigned int id=0;
 	socklen_t socklen;
 	ssize_t rd,wr;
+	packet_process_result ppr;
 	fd_set fdset;
 
 	{
@@ -438,24 +439,18 @@ static int dvt_main(void)
 				else if (rd>0)
 				{
 					uint32_t mark=0;
-					uint8_t res;
+					DLOG("packet: id=%u len=%zd\n", id, rd)
-					size_t len = rd;
+					ppr = processPacketData(&mark, NULL, buf, rd);
-
+					switch (ppr)
-					DLOG("packet: id=%u len=%zu\n", id, len)
-					res = processPacketData(&mark, NULL, buf, &len);
-					switch (res & VERDICT_MASK)
 					{
-					case VERDICT_PASS:
+					case pass:
-					case VERDICT_MODIFY:
+					case modify:
-						if ((res & VERDICT_MASK)==VERDICT_PASS)
+						DLOG(ppr==pass ? "packet: id=%u reinject unmodified\n" : "packet: id=%u reinject modified\n", id);
-							DLOG("packet: id=%u reinject unmodified\n", id)
+						wr = sendto(fd[i], buf, rd, 0, (struct sockaddr*)&sa_from, socklen);
-						else
-							DLOG("packet: id=%u reinject modified len=%zu\n", id, len)
-						wr = sendto(fd[i], buf, len, 0, (struct sockaddr*)&sa_from, socklen);
 						if (wr<0)
 							perror("reinject sendto");
-						else if (wr!=len)
+						else if (wr!=rd)
-							fprintf(stderr,"reinject sendto: not all data was reinjected. received %zu, sent %zd\n", len, wr);
+							fprintf(stderr,"reinject sendto: not all data was reinjected. received %zd, sent %zd\n", rd, wr);
 						break;
 					default:
 						DLOG("packet: id=%u drop\n", id);

nfq/nfqws.h

@@ -1,7 +1,7 @@
 #pragma once
 
-#define VERDICT_PASS	0
+typedef enum
-#define VERDICT_MODIFY	1
+{
-#define VERDICT_DROP	2
+	// frag=drop but do not fix checksum
-#define VERDICT_MASK	3
+	pass = 0, modify, drop, frag, modfrag
-#define VERDICT_NOCSUM	4
+} packet_process_result;