Add youtubeUnblock statistics

The statistis will be printed on exit in userspace version. In kernel
space version, use `cat /proc/kyoutubeUnblock`.

The feature was proposed by @IceCat74 in #220

README.md

@@ -435,6 +435,12 @@ cat /sys/module/kyoutubeUnblock/parameters/parameters
 
 and check all the parameters configured.
 
+You can check up the statistics of youtubeUnblock with
+
+```sh
+sudo cat /proc/kyoutubeUnblock
+```
+
 ### Building kernel module
 
 #### Building on host system

src/args.c

@@ -26,6 +26,7 @@
 #include "getopt.h"
 #include "raw_replacements.h"
 
+struct statistics_data global_stats;
 
 /**
  * Logging definitions

src/config.h

@@ -339,4 +339,13 @@ struct packet_data {
 	struct ytb_conntrack yct;
 };
 
+struct statistics_data {
+	unsigned long all_packet_counter;
+	unsigned long packet_counter;
+	unsigned long target_counter;
+	unsigned long sent_counter;
+};
+
+extern struct statistics_data global_stats;
+
 #endif /* YTB_CONFIG_H */

src/kytunblock.c

@@ -30,6 +30,7 @@
 #include <linux/net.h>
 #include <linux/kernel.h>
 #include <linux/version.h>
+#include <linux/proc_fs.h>
 
 #include <linux/netfilter.h>
 #include <linux/netfilter_ipv4.h>
@@ -329,6 +330,8 @@ erret_lc:
 		return ret;
 	}
 	
+	++global_stats.sent_counter;
+	
 	int ipvx = netproto_version(pkt, pktlen);
 
 	if (ipvx == IP4VERSION) {
@@ -483,6 +486,8 @@ static NF_CALLBACK(ykb_nf_hook, skb) {
 	struct config_t *config = cur_config;
 	kref_get(&config->refcount);
 
+	++global_stats.all_packet_counter;
+
 	if ((skb->mark & config->mark) == config->mark)  {
 		goto send_verdict;
 	}
@@ -523,12 +528,14 @@ static NF_CALLBACK(ykb_nf_hook, skb) {
 	pd.payload_len = skb->len;
 
 	int vrd = process_packet(config, &pd);
+	++global_stats.packet_counter;
 
 	switch(vrd) {
 		case PKT_ACCEPT:
 			nf_verdict = NF_ACCEPT;
 			break;
 		case PKT_DROP:
+			++global_stats.target_counter;
 			nf_verdict = NF_STOLEN;
 			kfree_skb(skb);
 			break;
@@ -580,6 +587,22 @@ static struct pernet_operations ykb_pernet_ops = {
 };
 #endif /* LINUX_VERSION_CODE >= KERNEL_VERSION(4, 3, 0) */
 
+#ifdef CONFIG_PROC_FS
+
+static int stats_show(struct seq_file *s, void *v) {
+	seq_printf(s, "youtubeUnblock stats: \n"
+		"\tCatched: %ld packets\n"
+		"\tProcessed: %ld packets\n"
+		"\tTargetted: %ld packets\n"
+		"\tSent over socket %ld packets\n",
+		global_stats.all_packet_counter, global_stats.packet_counter, 
+		global_stats.target_counter, global_stats.sent_counter);
+	
+	return 0;
+}
+
+#endif
+
 static int __init ykb_init(void) {
 	int ret;
 
@@ -615,6 +638,13 @@ static int __init ykb_init(void) {
 	}
 #endif /* NO_IPV6 */
 
+#ifdef CONFIG_PROC_FS
+	if (!proc_create_single_data("kyoutubeUnblock", 0440, NULL,
+			stats_show, NULL)) {
+		lgwarning("kyoutubeUnblock procfs entry creation failed");
+	}
+#endif
+
 #if LINUX_VERSION_CODE >= KERNEL_VERSION(4, 3, 0)
 	ret = register_pernet_subsys(&ykb_pernet_ops);
 #else
@@ -651,6 +681,10 @@ static void __exit ykb_destroy(void) {
 	close_raw6_socket();
 #endif
 
+#ifdef CONFIG_PROC_FS
+	remove_proc_entry("kyoutubeUnblock", NULL);
+#endif
+
 	close_raw_socket();
 	kref_put(&cur_config->refcount, config_release);
 	lginfo("youtubeUnblock kernel module destroyed.\n");

src/youtubeUnblock.c

@@ -46,6 +46,7 @@
 #include <linux/netfilter.h>
 #include <pthread.h>
 #include <sys/socket.h>
+#include <signal.h>
 
 #include "config.h"
 #include "mangle.h"
@@ -546,6 +547,7 @@ erret_lc:
 		return ret;
 	}
 	
+	++global_stats.sent_counter;
 	int ipvx = netproto_version(pkt, pktlen);
 
 	if (ipvx == IP4VERSION) {
@@ -640,6 +642,8 @@ static int queue_cb(const struct nlmsghdr *nlh, void *data) {
 	uint16_t l3num;	
 	uint32_t id;
 
+	++global_stats.all_packet_counter;
+
         if (nfq_nlmsg_parse(nlh, attr) < 0) {
                 lgerror(-errno, "Attr parse");
                 return MNL_CB_ERROR;
@@ -694,8 +698,11 @@ ct_out:
 
 	ret = process_packet(cur_config, &packet);
 
+	++global_stats.packet_counter;
+
 	switch (ret) {
 		case PKT_DROP:
+			++global_stats.target_counter;
 			nfq_nlmsg_verdict_put(verdnlh, id, NF_DROP);
 			break;
 		default:
@@ -875,6 +882,16 @@ struct instance_config_t instance_config = {
 	.send_delayed_packet = delay_packet_send,
 };
 
+void sigint_handler(int s) {
+	lginfo("youtubeUnblock stats: catched %ld packets, "
+		"processed %ld packets, "
+		"targetted %ld packets, sent over socket %ld packets",
+		global_stats.all_packet_counter, global_stats.packet_counter, 
+		global_stats.target_counter, global_stats.sent_counter);
+
+	exit(EXIT_SUCCESS);
+}
+
 int main(int argc, char *argv[]) {
 	int ret;
 	struct config_t config;
@@ -893,6 +910,8 @@ int main(int argc, char *argv[]) {
 	parse_global_lgconf(&config);
 	cur_config = &config;
 
+	signal(SIGINT, sigint_handler);
+	signal(SIGTERM, sigint_handler);
 
 	if (open_raw_socket() < 0) {
 		lgerror(-errno, "Unable to open raw socket");