Add option to disable ipv6, document ipv6

README.md

@@ -6,6 +6,7 @@
     - [Firewall configuration](#firewall-configuration)
       - [nftables rules](#nftables-rules)
       - [Iptables rules](#iptables-rules)
+    - [IPv6](#ipv6)
   - [Check it](#check-it)
   - [Flags](#flags)
   - [Troubleshooting](#troubleshooting)
@@ -104,6 +105,16 @@ iptables -t mangle -A FORWARD -p tcp --dport 443 -m connbytes --connbytes-dir or
 iptables -I OUTPUT -m mark --mark 32768/32768 -j ACCEPT
 ```
 
+#### IPv6
+
+For IPv6 on iptables you need to duplicate rules above for ip6tables:
+```sh
+ip6tables -t mangle -A FORWARD -p tcp --dport 443 -m connbytes --connbytes-dir original --connbytes-mode packets --connbytes 0:19 -j NFQUEUE --queue-num 537 --queue-bypass
+ip6tables -I OUTPUT -m mark --mark 32768/32768 -j ACCEPT
+```
+
+
+
 Note that above rules use *conntrack* to route only first 20 packets from the connection to **youtubeUnblock**. 
 If you got some troubles with it, for example **youtubeUnblock** doesn't detect YouTube, try to delete *connbytes* from the rules. But it is an unlikely behavior and you should probably check your ruleset.
 
@@ -170,6 +181,8 @@ Available flags:
 
 - `--no-gso` Disables support for Google Chrome fat packets which uses GSO. This feature is well tested now, so this flag probably won't fix anything.
 
+- `--no-ipv6` Disables support for ipv6. May be useful if you don't want for ipv6 socket to be opened.
+
 - `--threads=<threads number>` Specifies the amount of threads you want to be running for your program. This defaults to **1** and shouldn't be edited for normal use. If you have performance issues, consult [performance chaptr](https://github.com/Waujito/youtubeUnblock?tab=readme-ov-file#performance)
 
 ## Troubleshooting

args.c

@@ -20,6 +20,7 @@ struct config_t config = {
 	.fake_sni_seq_len = 1,
 	.frag_middle_sni = 1,
 	.frag_sni_pos = 2,
+	.use_ipv6 = 1,
 
 	.sni_detection = SNI_DETECTION_PARSE,
 
@@ -63,13 +64,14 @@ struct config_t config = {
 #define OPT_TRACE		15
 #define OPT_QUIC_DROP		16
 #define OPT_SNI_DETECTION	17
+#define OPT_NO_IPV6		20
 #define OPT_SEG2DELAY 		5
 #define OPT_THREADS 		6
 #define OPT_SILENT 		7
 #define OPT_NO_GSO 		8
 #define OPT_QUEUE_NUM		9
 
-#define OPT_MAX OPT_FRAG_SNI_POS
+#define OPT_MAX OPT_NO_IPV6
 
 static struct option long_opt[] = {
 	{"help",		0, 0, 'h'},
@@ -92,6 +94,7 @@ static struct option long_opt[] = {
 	{"silent",		0, 0, OPT_SILENT},
 	{"trace",		0, 0, OPT_TRACE},
 	{"no-gso",		0, 0, OPT_NO_GSO},
+	{"no-ipv6",		0, 0, OPT_NO_IPV6},
 	{"queue-num",		1, 0, OPT_QUEUE_NUM},
 	{0,0,0,0}
 };
@@ -144,6 +147,7 @@ void print_usage(const char *argv0) {
 	printf("\t--silent\n");
 	printf("\t--trace\n");
 	printf("\t--no-gso\n");
+	printf("\t--no-ipv6\n");
 	printf("\n");
 }
 
@@ -169,6 +173,9 @@ int parse_args(int argc, char *argv[]) {
 		case OPT_NO_GSO:
 			config.use_gso = 0;
 			break;
+		case OPT_NO_IPV6:
+			config.use_ipv6 = 0;
+			break;
 		case OPT_QUIC_DROP:
 			config.quic_drop = 1;
 			break;
@@ -393,6 +400,12 @@ void print_welcome() {
 		printf("GSO is enabled\n");
 	}
 
+	if (config.use_ipv6) {
+		printf("IPv6 is enabled\n");
+	} else {
+		printf("IPv6 is disabled\n");
+	}
+
 	if (config.quic_drop) {
 		printf("All QUIC packets will be dropped\n");
 	}

config.h

@@ -18,6 +18,7 @@ struct config_t {
 	unsigned int queue_start_num;
 	int threads;
 	int use_gso;
+	int use_ipv6;
 	int fragmentation_strategy;
 	int frag_sni_reverse;
 	int frag_sni_faked;

mangle.c

@@ -35,7 +35,7 @@ int process_packet(const uint8_t *raw_payload, uint32_t raw_payload_len) {
 
 		transport_proto = iph ->protocol;
 
-	} else if (ipver == IP6VERSION) {
+	} else if (ipver == IP6VERSION && config.use_ipv6) {
 		ret = ip6_payload_split((uint8_t *)raw_payload, raw_payload_len,
 			 (struct ip6_hdr **)&ip6h, &iph_len, 
 			 (uint8_t **)&ip_payload, &ip_payload_len);
@@ -45,12 +45,12 @@ int process_packet(const uint8_t *raw_payload, uint32_t raw_payload_len) {
 
 		transport_proto = ip6h->ip6_ctlun.ip6_un1.ip6_un1_nxt;
 
+	} else {
+		lgtracemsg("Unknown layer 3 protocol version: %d", ipver);
+		goto accept;
 	}
 
 	
-	if (ret < 0) 
-		goto accept;
-	
 	switch (transport_proto) {
 	case IPPROTO_TCP:
 		return process_tcp_packet(raw_payload, raw_payload_len);

youtubeUnblock.c

@@ -579,11 +579,13 @@ int main(int argc, char *argv[]) {
 		exit(EXIT_FAILURE);
 	}
 
+	if (config.use_ipv6) {
 		if (open_raw6_socket() < 0) {
 			perror("Unable to open raw socket for ipv6");
 			close_raw_socket();
 			exit(EXIT_FAILURE);
 		}
+	}
 
 	struct queue_res *qres = &defqres;
 
@@ -618,6 +620,7 @@ int main(int argc, char *argv[]) {
 	}
 
 	close_raw_socket();
+	if (config.use_ipv6)
 		close_raw6_socket();
 
 	return -qres->status;