sctp: move hlist_node and hashent out of sctp_ep_common

[ Upstream commit 3d3b2f57d4 ]

Struct sctp_ep_common is included in both asoc and ep, but hlist_node
and hashent are only needed by ep after asoc_hashtable was dropped by
Commit b5eff71283 ("sctp: drop the old assoc hashtable of sctp").

So it is better to move hlist_node and hashent from sctp_ep_common to
sctp_endpoint, and it saves some space for each asoc.

Signed-off-by: Xin Long <lucien.xin@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Stable-dep-of: 9ab0faa7f9ff ("sctp: Fix null-ptr-deref in reuseport_add_sock().")
Signed-off-by: Sasha Levin <sashal@kernel.org>

include/net/sctp/sctp.h

@@ -509,8 +509,8 @@ static inline int sctp_ep_hashfn(struct net *net, __u16 lport)
 	return (net_hash_mix(net) + lport) & (sctp_ep_hashsize - 1);
 }
 
-#define sctp_for_each_hentry(epb, head) \
-	hlist_for_each_entry(epb, head, node)
+#define sctp_for_each_hentry(ep, head) \
+	hlist_for_each_entry(ep, head, node)
 
 /* Is a socket of this style? */
 #define sctp_style(sk, style) __sctp_style((sk), (SCTP_SOCKET_##style))

include/net/sctp/structs.h

@@ -1244,10 +1244,6 @@ enum sctp_endpoint_type {
  */
 
 struct sctp_ep_common {
-	/* Fields to help us manage our entries in the hash tables. */
-	struct hlist_node node;
-	int hashent;
-
 	/* Runtime type information.  What kind of endpoint is this? */
 	enum sctp_endpoint_type type;
 
@@ -1299,6 +1295,10 @@ struct sctp_endpoint {
 	/* Common substructure for endpoint and association. */
 	struct sctp_ep_common base;
 
+	/* Fields to help us manage our entries in the hash tables. */
+	struct hlist_node node;
+	int hashent;
+
 	/* Associations: A list of current associations and mappings
 	 *	      to the data consumers for each association. This
 	 *	      may be in the form of a hash table or other

net/sctp/input.c

@@ -748,23 +748,21 @@ static int __sctp_hash_endpoint(struct sctp_endpoint *ep)
 	struct sock *sk = ep->base.sk;
 	struct net *net = sock_net(sk);
 	struct sctp_hashbucket *head;
-	struct sctp_ep_common *epb;
 
-	epb = &ep->base;
-	epb->hashent = sctp_ep_hashfn(net, epb->bind_addr.port);
-	head = &sctp_ep_hashtable[epb->hashent];
+	ep->hashent = sctp_ep_hashfn(net, ep->base.bind_addr.port);
+	head = &sctp_ep_hashtable[ep->hashent];
 
 	if (sk->sk_reuseport) {
 		bool any = sctp_is_ep_boundall(sk);
-		struct sctp_ep_common *epb2;
+		struct sctp_endpoint *ep2;
 		struct list_head *list;
 		int cnt = 0, err = 1;
 
 		list_for_each(list, &ep->base.bind_addr.address_list)
 			cnt++;
 
-		sctp_for_each_hentry(epb2, &head->chain) {
-			struct sock *sk2 = epb2->sk;
+		sctp_for_each_hentry(ep2, &head->chain) {
+			struct sock *sk2 = ep2->base.sk;
 
 			if (!net_eq(sock_net(sk2), net) || sk2 == sk ||
 			    !uid_eq(sock_i_uid(sk2), sock_i_uid(sk)) ||
@@ -791,7 +789,7 @@ static int __sctp_hash_endpoint(struct sctp_endpoint *ep)
 	}
 
 	write_lock(&head->lock);
-	hlist_add_head(&epb->node, &head->chain);
+	hlist_add_head(&ep->node, &head->chain);
 	write_unlock(&head->lock);
 	return 0;
 }
@@ -813,19 +811,16 @@ static void __sctp_unhash_endpoint(struct sctp_endpoint *ep)
 {
 	struct sock *sk = ep->base.sk;
 	struct sctp_hashbucket *head;
-	struct sctp_ep_common *epb;
 
-	epb = &ep->base;
+	ep->hashent = sctp_ep_hashfn(sock_net(sk), ep->base.bind_addr.port);
 
-	epb->hashent = sctp_ep_hashfn(sock_net(sk), epb->bind_addr.port);
-
-	head = &sctp_ep_hashtable[epb->hashent];
+	head = &sctp_ep_hashtable[ep->hashent];
 
 	if (rcu_access_pointer(sk->sk_reuseport_cb))
 		reuseport_detach_sock(sk);
 
 	write_lock(&head->lock);
-	hlist_del_init(&epb->node);
+	hlist_del_init(&ep->node);
 	write_unlock(&head->lock);
 }
 
@@ -858,7 +853,6 @@ static struct sctp_endpoint *__sctp_rcv_lookup_endpoint(
 					const union sctp_addr *paddr)
 {
 	struct sctp_hashbucket *head;
-	struct sctp_ep_common *epb;
 	struct sctp_endpoint *ep;
 	struct sock *sk;
 	__be16 lport;
@@ -868,8 +862,7 @@ static struct sctp_endpoint *__sctp_rcv_lookup_endpoint(
 	hash = sctp_ep_hashfn(net, ntohs(lport));
 	head = &sctp_ep_hashtable[hash];
 	read_lock(&head->lock);
-	sctp_for_each_hentry(epb, &head->chain) {
-		ep = sctp_ep(epb);
+	sctp_for_each_hentry(ep, &head->chain) {
 		if (sctp_endpoint_is_match(ep, net, laddr))
 			goto hit;
 	}

net/sctp/proc.c

@@ -161,7 +161,6 @@ static void *sctp_eps_seq_next(struct seq_file *seq, void *v, loff_t *pos)
 static int sctp_eps_seq_show(struct seq_file *seq, void *v)
 {
 	struct sctp_hashbucket *head;
-	struct sctp_ep_common *epb;
 	struct sctp_endpoint *ep;
 	struct sock *sk;
 	int    hash = *(loff_t *)v;
@@ -171,18 +170,17 @@ static int sctp_eps_seq_show(struct seq_file *seq, void *v)
 
 	head = &sctp_ep_hashtable[hash];
 	read_lock_bh(&head->lock);
-	sctp_for_each_hentry(epb, &head->chain) {
-		ep = sctp_ep(epb);
-		sk = epb->sk;
+	sctp_for_each_hentry(ep, &head->chain) {
+		sk = ep->base.sk;
 		if (!net_eq(sock_net(sk), seq_file_net(seq)))
 			continue;
 		seq_printf(seq, "%8pK %8pK %-3d %-3d %-4d %-5d %5u %5lu ", ep, sk,
 			   sctp_sk(sk)->type, sk->sk_state, hash,
-			   epb->bind_addr.port,
+			   ep->base.bind_addr.port,
 			   from_kuid_munged(seq_user_ns(seq), sock_i_uid(sk)),
 			   sock_i_ino(sk));
 
-		sctp_seq_dump_local_addrs(seq, epb);
+		sctp_seq_dump_local_addrs(seq, &ep->base);
 		seq_printf(seq, "\n");
 	}
 	read_unlock_bh(&head->lock);

net/sctp/socket.c

@@ -5303,14 +5303,14 @@ int sctp_for_each_endpoint(int (*cb)(struct sctp_endpoint *, void *),
 			   void *p) {
 	int err = 0;
 	int hash = 0;
-	struct sctp_ep_common *epb;
+	struct sctp_endpoint *ep;
 	struct sctp_hashbucket *head;
 
 	for (head = sctp_ep_hashtable; hash < sctp_ep_hashsize;
 	     hash++, head++) {
 		read_lock_bh(&head->lock);
-		sctp_for_each_hentry(epb, &head->chain) {
-			err = cb(sctp_ep(epb), p);
+		sctp_for_each_hentry(ep, &head->chain) {
+			err = cb(ep, p);
 			if (err)
 				break;
 		}