inet: add bound ports statistic

index 9141e95529e7..dc74f7af4446 100644
@@ -103,6 +103,7 @@ static inline struct net *ib_net(struct inet_bind_bucket *ib)
 
 struct inet_bind_hashbucket {
 	spinlock_t		lock;
+	int			count;
 	struct hlist_head	chain;
 };
 

@@ -193,7 +194,9 @@ inet_bind_bucket_create(struct kmem_cache *cachep, struct net *net,
 			struct inet_bind_hashbucket *head,
 			const unsigned short snum);
 void inet_bind_bucket_destroy(struct kmem_cache *cachep,
+			      struct inet_bind_hashbucket *head,
 			      struct inet_bind_bucket *tb);
+int inet_bind_bucket_count(struct proto *prot);
 
 static inline u32 inet_bhashfn(const struct net *net, const __u16 lport,
 			       const u32 bhash_size)

index c7be1ca8e562..4cdb8034ad80 100644
@@ -87,7 +87,9 @@ static inline struct inet_timewait_sock *inet_twsk(const struct sock *sk)
 void inet_twsk_free(struct inet_timewait_sock *tw);
 void inet_twsk_put(struct inet_timewait_sock *tw);
 
+struct inet_bind_hashbucket;
 void inet_twsk_bind_unhash(struct inet_timewait_sock *tw,
+			   struct inet_bind_hashbucket *head,
 			   struct inet_hashinfo *hashinfo);
 
 struct inet_timewait_sock *inet_twsk_alloc(const struct sock *sk,

index 84cd4e3fd01b..25f03e62cfea 100644
@@ -1208,6 +1208,7 @@ static int __init dccp_init(void)
 	for (i = 0; i < dccp_hashinfo.bhash_size; i++) {
 		spin_lock_init(&dccp_hashinfo.bhash[i].lock);
 		INIT_HLIST_HEAD(&dccp_hashinfo.bhash[i].chain);
+		dccp_hashinfo.bhash[i].count = 0;
 	}
 
 	rc = dccp_mib_init();

index 881ac6d046f2..8a70465c240c 100644
@@ -309,6 +309,7 @@ int inet_csk_get_port(struct sock *sk, unsigned short snum)
 				     net, head, port);
 	if (!tb)
 		goto fail_unlock;
+	++head->count;
 tb_found:
 	if (!hlist_empty(&tb->owners)) {
 		if (sk->sk_reuse == SK_FORCE_REUSE)

index 31ff46daae97..f7c7a589bfb3 100644
@@ -58,6 +58,18 @@ static u32 sk_ehashfn(const struct sock *sk)
 			    sk->sk_daddr, sk->sk_dport);
 }
 
+/* Count how many any entries are in the bind hash table */
+int inet_bind_bucket_count(struct proto *prot)
+{
+	struct inet_hashinfo *hinfo = prot->h.hashinfo;
+	int i, ports = 0;
+
+	for (i = 0; i < hinfo->bhash_size; i++)
+		ports += hinfo->bhash[i].count;
+
+	return ports;
+}
+
 /*
  * Allocate and initialize a new local port bind bucket.
  * The bindhash mutex for snum's hash chain must be held here.

@@ -76,6 +88,7 @@ struct inet_bind_bucket *inet_bind_bucket_create(struct kmem_cache *cachep,
 		tb->fastreuseport = 0;
 		INIT_HLIST_HEAD(&tb->owners);
 		hlist_add_head(&tb->node, &head->chain);
+		++head->count;
 	}
 	return tb;
 }

@@ -83,10 +96,13 @@ struct inet_bind_bucket *inet_bind_bucket_create(struct kmem_cache *cachep,
 /*
  * Caller must hold hashbucket lock for this tb with local BH disabled
  */
-void inet_bind_bucket_destroy(struct kmem_cache *cachep, struct inet_bind_bucket *tb)
+void inet_bind_bucket_destroy(struct kmem_cache *cachep,
+			      struct inet_bind_hashbucket *head,
+			      struct inet_bind_bucket *tb)
 {
 	if (hlist_empty(&tb->owners)) {
 		__hlist_del(&tb->node);
+		--head->count;
 		kmem_cache_free(cachep, tb);
 	}
 }

@@ -115,7 +131,7 @@ static void __inet_put_port(struct sock *sk)
 	__sk_del_bind_node(sk);
 	inet_csk(sk)->icsk_bind_hash = NULL;
 	inet_sk(sk)->inet_num = 0;
-	inet_bind_bucket_destroy(hashinfo->bind_bucket_cachep, tb);
+	inet_bind_bucket_destroy(hashinfo->bind_bucket_cachep, head, tb);
 	spin_unlock(&head->lock);
 }
 

@@ -756,7 +772,7 @@ int __inet_hash_connect(struct inet_timewait_death_row *death_row,
 		inet_ehash_nolisten(sk, (struct sock *)tw);
 	}
 	if (tw)
-		inet_twsk_bind_unhash(tw, hinfo);
+		inet_twsk_bind_unhash(tw, head, hinfo);
 	spin_unlock(&head->lock);
 	if (tw)
 		inet_twsk_deschedule_put(tw);

index 88c5069b5d20..dd888c52f958 100644
@@ -26,7 +26,8 @@
  *	Returns 1 if caller should call inet_twsk_put() after lock release.
  */
 void inet_twsk_bind_unhash(struct inet_timewait_sock *tw,
-			  struct inet_hashinfo *hashinfo)
+			   struct inet_bind_hashbucket *head,
+			   struct inet_hashinfo *hashinfo)
 {
 	struct inet_bind_bucket *tb = tw->tw_tb;
 

@@ -35,7 +36,8 @@ void inet_twsk_bind_unhash(struct inet_timewait_sock *tw,
 
 	__hlist_del(&tw->tw_bind_node);
 	tw->tw_tb = NULL;
-	inet_bind_bucket_destroy(hashinfo->bind_bucket_cachep, tb);
+	inet_bind_bucket_destroy(hashinfo->bind_bucket_cachep,
+				 head, tb);
 	__sock_put((struct sock *)tw);
 }
 

@@ -55,7 +57,7 @@ static void inet_twsk_kill(struct inet_timewait_sock *tw)
 			hashinfo->bhash_size)];
 
 	spin_lock(&bhead->lock);
-	inet_twsk_bind_unhash(tw, hashinfo);
+	inet_twsk_bind_unhash(tw, bhead, hashinfo);
 	spin_unlock(&bhead->lock);
 
 	atomic_dec(&tw->tw_dr->tw_count);

index 261b71d0ccc5..12621f8fb4d5 100644
@@ -60,10 +60,11 @@ static int sockstat_seq_show(struct seq_file *seq, void *v)
 	sockets = proto_sockets_allocated_sum_positive(&tcp_prot);
 
 	socket_seq_show(seq);
-	seq_printf(seq, "TCP: inuse %d orphan %d tw %d alloc %d mem %ld\n",
+	seq_printf(seq, "TCP: inuse %d orphan %d tw %d alloc %d mem %ld ports %d\n",
 		   sock_prot_inuse_get(net, &tcp_prot), orphans,
 		   atomic_read(&net->ipv4.tcp_death_row.tw_count), sockets,
-		   proto_memory_allocated(&tcp_prot));
+		   proto_memory_allocated(&tcp_prot),
+		   inet_bind_bucket_count(&tcp_prot));
 	seq_printf(seq, "UDP: inuse %d mem %ld\n",
 		   sock_prot_inuse_get(net, &udp_prot),
 		   proto_memory_allocated(&udp_prot));

index 868ed74a76a8..f62e2fb02fdf 100644
@@ -3836,6 +3836,7 @@ void __init tcp_init(void)
 	for (i = 0; i < tcp_hashinfo.bhash_size; i++) {
 		spin_lock_init(&tcp_hashinfo.bhash[i].lock);
 		INIT_HLIST_HEAD(&tcp_hashinfo.bhash[i].chain);
+		tcp_hashinfo.bhash[i].count = 0;
 	}