Allow to change default mark

Related to #96

README.md

@@ -187,6 +187,8 @@ Available flags:
 
 - `--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)
 
+- `--packet-mark=<mark>` Use this option if youtubeUnblock conflicts with other systems rely on packet mark. Note that you may want to change accept rule for iptables to follow the mark.
+
 ## Troubleshooting
 
 If you got troubles with some sites and you sure that they are blocked by SNI (youtube for example), use may play around with [flags](#flags) and their combinations. At first it is recommended to try `--faking-strategy` flag and `--frag-sni-faked=1`.

args.c

@@ -22,6 +22,7 @@ struct config_t config = {
 	.frag_sni_pos = 2,
 	.use_ipv6 = 1,
 	.fakeseq_offset = 10000,
+	.mark = DEFAULT_RAWSOCKET_MARK,
 
 	.sni_detection = SNI_DETECTION_PARSE,
 
@@ -67,13 +68,14 @@ struct config_t config = {
 #define OPT_SNI_DETECTION	17
 #define OPT_NO_IPV6		20
 #define OPT_FAKE_SEQ_OFFSET	21
+#define OPT_PACKET_MARK 	22
 #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_FAKE_SEQ_OFFSET
+#define OPT_MAX OPT_PACKET_MARK 
 
 static struct option long_opt[] = {
 	{"help",		0, 0, 'h'},
@@ -99,6 +101,7 @@ static struct option long_opt[] = {
 	{"no-gso",		0, 0, OPT_NO_GSO},
 	{"no-ipv6",		0, 0, OPT_NO_IPV6},
 	{"queue-num",		1, 0, OPT_QUEUE_NUM},
+	{"packet-mark",		1, 0, OPT_PACKET_MARK},
 	{0,0,0,0}
 };
 
@@ -148,6 +151,7 @@ void print_usage(const char *argv0) {
 	printf("\t--sni-detection={parse|brute}\n");
 	printf("\t--seg2delay=<delay>\n");
 	printf("\t--threads=<threads number>\n");
+	printf("\t--packet-mark=<mark>\n");
 	printf("\t--silent\n");
 	printf("\t--trace\n");
 	printf("\t--no-gso\n");
@@ -331,6 +335,15 @@ int parse_args(int argc, char *argv[]) {
 
 			config.queue_start_num = num;
 			break;
+		case OPT_PACKET_MARK:
+			num = parse_numeric_option(optarg);
+			if (errno != 0 || num < 0) {
+				goto invalid_opt;
+			}
+
+			config.mark = num;
+			break;
+
 		default:
 			goto error;
 		}

config.h

@@ -45,6 +45,7 @@ struct config_t {
 	unsigned int fake_sni_pkt_sz;
 	unsigned int fk_winsize;
 	unsigned int fakeseq_offset;
+	unsigned int mark;
 };
 
 extern struct config_t config;
@@ -71,7 +72,7 @@ extern struct config_t config;
 #define FRAGMENTATION_STRATEGY FRAG_STRAT_TCP
 #endif
 
-#define RAWSOCKET_MARK (1 << 15)
+#define DEFAULT_RAWSOCKET_MARK (1 << 15)
 
 #ifdef USE_SEG2_DELAY
 #define SEG2_DELAY 100

youtubeUnblock.c

@@ -87,7 +87,7 @@ static int open_raw_socket(void) {
 		return -1;
 	}
 
-	int mark = RAWSOCKET_MARK;
+	int mark = config.mark;
 	if (setsockopt(rawsocket, SOL_SOCKET, SO_MARK, &mark, sizeof(mark)) < 0)
 	{
 		fprintf(stderr, "setsockopt(SO_MARK, %d) failed\n", mark);
@@ -139,7 +139,7 @@ static int open_raw6_socket(void) {
 		return -1;
 	}
 
-	int mark = RAWSOCKET_MARK;
+	int mark = config.mark;
 	if (setsockopt(raw6socket, SOL_SOCKET, SO_MARK, &mark, sizeof(mark)) < 0)
 	{
 		fprintf(stderr, "setsockopt(SO_MARK, %d) failed\n", mark);
@@ -424,8 +424,8 @@ static int queue_cb(const struct nlmsghdr *nlh, void *data) {
 
 	if (attr[NFQA_MARK] != NULL) {
 		// Skip packets sent by rawsocket to escape infinity loop.
-		if ((ntohl(mnl_attr_get_u32(attr[NFQA_MARK])) & RAWSOCKET_MARK) == 
+		if ((ntohl(mnl_attr_get_u32(attr[NFQA_MARK])) & config.mark) == 
-			RAWSOCKET_MARK) {
+			config.mark) {
 			return fallback_accept_packet(packet.id, *qdata);
 		}
 	}