Merge branch 'tcp-fast-so_reuseport'

Craig Gallek says:

====================
Faster SO_REUSEPORT for TCP

This patch series complements an earlier series (6a5ef90c58da)
which added faster SO_REUSEPORT lookup for UDP sockets by
extending the feature to TCP sockets.  It uses the same
array-based data structure which allows for socket selection
after finding the first listening socket that matches an incoming
packet.  Prior to this feature, every socket in the reuseport
group needed to be found and examined before a selection could be
made.

With this series the SO_ATTACH_REUSEPORT_CBPF and
SO_ATTACH_REUSEPORT_EBPF socket options now work for TCP sockets
as well.  The test at the end of the series includes an example of
how to use these options to select a reuseport socket based on the
cpu core id handling the incoming packet.

There are several refactoring patches that precede the feature
implementation.  Only the last two patches in this series
should result in any behavioral changes.

v4
- Fix build issue when compiling IPv6 as a module.  This required
  moving the ipv6_rcv_saddr_equal into an object that is included as a
  built-in object.  I included this change in the second patch which
  adds inet6_hash since that is where ipv6_rcv_saddr_equal will
  later be called from non-module code.

v3:
- Another warning in the first patch caught by a build bot.  Return 0 in
  the no-op UDP hash function.

v2:
- In the first patched I missed a couple of hash functions that should now be
  returning int instead of void.  I missed these the first time through as it
  only generated a warning and not an error :\
====================

Signed-off-by: David S. Miller <davem@davemloft.net>

23 files changed, 258 insertions, 105 deletions

diff --git a/net/core/filter.c b/net/core/filter.c
index 94d26201080d..2a6e9562f1ab 100644
--- a/net/core/filter.c
+++ b/net/core/filter.c
@@ -1181,7 +1181,7 @@ static int __reuseport_attach_prog(struct bpf_prog *prog, struct sock *sk)
 	if (bpf_prog_size(prog->len) > sysctl_optmem_max)
 		return -ENOMEM;
 
-	if (sk_unhashed(sk)) {
+	if (sk_unhashed(sk) && sk->sk_reuseport) {
 		err = reuseport_alloc(sk);
 		if (err)
 			return err;
diff --git a/net/core/sock.c b/net/core/sock.c
index 6c1c8bc93412..46dc8ad7d050 100644
--- a/net/core/sock.c
+++ b/net/core/sock.c
@@ -1531,6 +1531,7 @@ struct sock *sk_clone_lock(const struct sock *sk, const gfp_t priority)
 			newsk = NULL;
 			goto out;
 		}
+		RCU_INIT_POINTER(newsk->sk_reuseport_cb, NULL);
 
 		newsk->sk_err	   = 0;
 		newsk->sk_priority = 0;
diff --git a/net/dccp/ipv4.c b/net/dccp/ipv4.c
index 5684e14932bd..1e0c600c83ae 100644
--- a/net/dccp/ipv4.c
+++ b/net/dccp/ipv4.c
@@ -802,7 +802,7 @@ static int dccp_v4_rcv(struct sk_buff *skb)
 	}
 
 lookup:
-	sk = __inet_lookup_skb(&dccp_hashinfo, skb,
+	sk = __inet_lookup_skb(&dccp_hashinfo, skb, __dccp_hdr_len(dh),
 			       dh->dccph_sport, dh->dccph_dport);
 	if (!sk) {
 		dccp_pr_debug("failed to look up flow ID in table and "
diff --git a/net/dccp/ipv6.c b/net/dccp/ipv6.c
index 9c6d0508e63a..45cbe85f0940 100644
--- a/net/dccp/ipv6.c
+++ b/net/dccp/ipv6.c
@@ -668,7 +668,7 @@ static int dccp_v6_rcv(struct sk_buff *skb)
 		DCCP_SKB_CB(skb)->dccpd_ack_seq = dccp_hdr_ack_seq(skb);
 
 lookup:
-	sk = __inet6_lookup_skb(&dccp_hashinfo, skb,
+	sk = __inet6_lookup_skb(&dccp_hashinfo, skb, __dccp_hdr_len(dh),
 			        dh->dccph_sport, dh->dccph_dport,
 				inet6_iif(skb));
 	if (!sk) {
@@ -993,7 +993,7 @@ static struct proto dccp_v6_prot = {
 	.sendmsg	   = dccp_sendmsg,
 	.recvmsg	   = dccp_recvmsg,
 	.backlog_rcv	   = dccp_v6_do_rcv,
-	.hash		   = inet_hash,
+	.hash		   = inet6_hash,
 	.unhash		   = inet_unhash,
 	.accept		   = inet_csk_accept,
 	.get_port	   = inet_csk_get_port,
diff --git a/net/ieee802154/socket.c b/net/ieee802154/socket.c
index a548be247e15..e0bd013a1e5e 100644
--- a/net/ieee802154/socket.c
+++ b/net/ieee802154/socket.c
@@ -182,12 +182,14 @@ static int ieee802154_sock_ioctl(struct socket *sock, unsigned int cmd,
 static HLIST_HEAD(raw_head);
 static DEFINE_RWLOCK(raw_lock);
 
-static void raw_hash(struct sock *sk)
+static int raw_hash(struct sock *sk)
 {
 	write_lock_bh(&raw_lock);
 	sk_add_node(sk, &raw_head);
 	sock_prot_inuse_add(sock_net(sk), sk->sk_prot, 1);
 	write_unlock_bh(&raw_lock);
+
+	return 0;
 }
 
 static void raw_unhash(struct sock *sk)
@@ -462,12 +464,14 @@ static inline struct dgram_sock *dgram_sk(const struct sock *sk)
 	return container_of(sk, struct dgram_sock, sk);
 }
 
-static void dgram_hash(struct sock *sk)
+static int dgram_hash(struct sock *sk)
 {
 	write_lock_bh(&dgram_lock);
 	sk_add_node(sk, &dgram_head);
 	sock_prot_inuse_add(sock_net(sk), sk->sk_prot, 1);
 	write_unlock_bh(&dgram_lock);
+
+	return 0;
 }
 
 static void dgram_unhash(struct sock *sk)
@@ -1026,8 +1030,13 @@ static int ieee802154_create(struct net *net, struct socket *sock,
 	/* Checksums on by default */
 	sock_set_flag(sk, SOCK_ZAPPED);
 
-	if (sk->sk_prot->hash)
-		sk->sk_prot->hash(sk);
+	if (sk->sk_prot->hash) {
+		rc = sk->sk_prot->hash(sk);
+		if (rc) {
+			sk_common_release(sk);
+			goto out;
+		}
+	}
 
 	if (sk->sk_prot->init) {
 		rc = sk->sk_prot->init(sk);
diff --git a/net/ipv4/af_inet.c b/net/ipv4/af_inet.c
index 5c5db6636704..eade66db214e 100644
--- a/net/ipv4/af_inet.c
+++ b/net/ipv4/af_inet.c
@@ -370,7 +370,11 @@ lookup_protocol:
 		 */
 		inet->inet_sport = htons(inet->inet_num);
 		/* Add to protocol hash chains. */
-		sk->sk_prot->hash(sk);
+		err = sk->sk_prot->hash(sk);
+		if (err) {
+			sk_common_release(sk);
+			goto out;
+		}
 	}
 
 	if (sk->sk_prot->init) {
@@ -1142,8 +1146,7 @@ static int inet_sk_reselect_saddr(struct sock *sk)
 	 * Besides that, it does not check for connection
 	 * uniqueness. Wait for troubles.
 	 */
-	__sk_prot_rehash(sk);
-	return 0;
+	return __sk_prot_rehash(sk);
 }
 
 int inet_sk_rebuild_header(struct sock *sk)
diff --git a/net/ipv4/inet_connection_sock.c b/net/ipv4/inet_connection_sock.c
index 9b17c1792dce..c16a2e6273d9 100644
--- a/net/ipv4/inet_connection_sock.c
+++ b/net/ipv4/inet_connection_sock.c
@@ -24,6 +24,7 @@
 #include <net/tcp_states.h>
 #include <net/xfrm.h>
 #include <net/tcp.h>
+#include <net/sock_reuseport.h>
 
 #ifdef INET_CSK_DEBUG
 const char inet_csk_timer_bug_msg[] = "inet_csk BUG: unknown timer value\n";
@@ -67,7 +68,8 @@ int inet_csk_bind_conflict(const struct sock *sk,
 			if ((!reuse || !sk2->sk_reuse ||
 			    sk2->sk_state == TCP_LISTEN) &&
 			    (!reuseport || !sk2->sk_reuseport ||
-			    (sk2->sk_state != TCP_TIME_WAIT &&
+			     rcu_access_pointer(sk->sk_reuseport_cb) ||
+			     (sk2->sk_state != TCP_TIME_WAIT &&
 			     !uid_eq(uid, sock_i_uid(sk2))))) {
 
 				if (!sk2->sk_rcv_saddr || !sk->sk_rcv_saddr ||
@@ -132,6 +134,7 @@ again:
 					      sk->sk_state != TCP_LISTEN) ||
 					     (tb->fastreuseport > 0 &&
 					      sk->sk_reuseport &&
+					      !rcu_access_pointer(sk->sk_reuseport_cb) &&
 					      uid_eq(tb->fastuid, uid))) &&
 					    (tb->num_owners < smallest_size || smallest_size == -1)) {
 						smallest_size = tb->num_owners;
@@ -193,15 +196,18 @@ tb_found:
 		if (((tb->fastreuse > 0 &&
 		      sk->sk_reuse && sk->sk_state != TCP_LISTEN) ||
 		     (tb->fastreuseport > 0 &&
-		      sk->sk_reuseport && uid_eq(tb->fastuid, uid))) &&
-		    smallest_size == -1) {
+		      sk->sk_reuseport &&
+		      !rcu_access_pointer(sk->sk_reuseport_cb) &&
+		      uid_eq(tb->fastuid, uid))) && smallest_size == -1) {
 			goto success;
 		} else {
 			ret = 1;
 			if (inet_csk(sk)->icsk_af_ops->bind_conflict(sk, tb, true)) {
 				if (((sk->sk_reuse && sk->sk_state != TCP_LISTEN) ||
 				     (tb->fastreuseport > 0 &&
-				      sk->sk_reuseport && uid_eq(tb->fastuid, uid))) &&
+				      sk->sk_reuseport &&
+				      !rcu_access_pointer(sk->sk_reuseport_cb) &&
+				      uid_eq(tb->fastuid, uid))) &&
 				    smallest_size != -1 && --attempts >= 0) {
 					spin_unlock(&head->lock);
 					goto again;
@@ -734,6 +740,7 @@ int inet_csk_listen_start(struct sock *sk, int backlog)
 {
 	struct inet_connection_sock *icsk = inet_csk(sk);
 	struct inet_sock *inet = inet_sk(sk);
+	int err = -EADDRINUSE;
 
 	reqsk_queue_alloc(&icsk->icsk_accept_queue);
 
@@ -751,13 +758,14 @@ int inet_csk_listen_start(struct sock *sk, int backlog)
 		inet->inet_sport = htons(inet->inet_num);
 
 		sk_dst_reset(sk);
-		sk->sk_prot->hash(sk);
+		err = sk->sk_prot->hash(sk);
 
-		return 0;
+		if (likely(!err))
+			return 0;
 	}
 
 	sk->sk_state = TCP_CLOSE;
-	return -EADDRINUSE;
+	return err;
 }
 EXPORT_SYMBOL_GPL(inet_csk_listen_start);
 
diff --git a/net/ipv4/inet_diag.c b/net/ipv4/inet_diag.c
index 6029157a19ed..50c0d96b8441 100644
--- a/net/ipv4/inet_diag.c
+++ b/net/ipv4/inet_diag.c
@@ -357,18 +357,18 @@ struct sock *inet_diag_find_one_icsk(struct net *net,
 	struct sock *sk;
 
 	if (req->sdiag_family == AF_INET)
-		sk = inet_lookup(net, hashinfo, req->id.idiag_dst[0],
+		sk = inet_lookup(net, hashinfo, NULL, 0, req->id.idiag_dst[0],
 				 req->id.idiag_dport, req->id.idiag_src[0],
 				 req->id.idiag_sport, req->id.idiag_if);
 #if IS_ENABLED(CONFIG_IPV6)
 	else if (req->sdiag_family == AF_INET6) {
 		if (ipv6_addr_v4mapped((struct in6_addr *)req->id.idiag_dst) &&
 		    ipv6_addr_v4mapped((struct in6_addr *)req->id.idiag_src))
-			sk = inet_lookup(net, hashinfo, req->id.idiag_dst[3],
+			sk = inet_lookup(net, hashinfo, NULL, 0, req->id.idiag_dst[3],
 					 req->id.idiag_dport, req->id.idiag_src[3],
 					 req->id.idiag_sport, req->id.idiag_if);
 		else
-			sk = inet6_lookup(net, hashinfo,
+			sk = inet6_lookup(net, hashinfo, NULL, 0,
 					  (struct in6_addr *)req->id.idiag_dst,
 					  req->id.idiag_dport,
 					  (struct in6_addr *)req->id.idiag_src,
diff --git a/net/ipv4/inet_hashtables.c b/net/ipv4/inet_hashtables.c
index ccc5980797fc..c0f9942de924 100644
--- a/net/ipv4/inet_hashtables.c
+++ b/net/ipv4/inet_hashtables.c
@@ -20,10 +20,12 @@
 #include <linux/wait.h>
 #include <linux/vmalloc.h>
 
+#include <net/addrconf.h>
 #include <net/inet_connection_sock.h>
 #include <net/inet_hashtables.h>
 #include <net/secure_seq.h>
 #include <net/ip.h>
+#include <net/sock_reuseport.h>
 
 static u32 inet_ehashfn(const struct net *net, const __be32 laddr,
 			const __u16 lport, const __be32 faddr,
@@ -205,6 +207,7 @@ static inline int compute_score(struct sock *sk, struct net *net,
 
 struct sock *__inet_lookup_listener(struct net *net,
 				    struct inet_hashinfo *hashinfo,
+				    struct sk_buff *skb, int doff,
 				    const __be32 saddr, __be16 sport,
 				    const __be32 daddr, const unsigned short hnum,
 				    const int dif)
@@ -214,6 +217,7 @@ struct sock *__inet_lookup_listener(struct net *net,
 	unsigned int hash = inet_lhashfn(net, hnum);
 	struct inet_listen_hashbucket *ilb = &hashinfo->listening_hash[hash];
 	int score, hiscore, matches = 0, reuseport = 0;
+	bool select_ok = true;
 	u32 phash = 0;
 
 	rcu_read_lock();
@@ -229,6 +233,15 @@ begin:
 			if (reuseport) {
 				phash = inet_ehashfn(net, daddr, hnum,
 						     saddr, sport);
+				if (select_ok) {
+					struct sock *sk2;
+					sk2 = reuseport_select_sock(sk, phash,
+								    skb, doff);
+					if (sk2) {
+						result = sk2;
+						goto found;
+					}
+				}
 				matches = 1;
 			}
 		} else if (score == hiscore && reuseport) {
@@ -246,11 +259,13 @@ begin:
 	if (get_nulls_value(node) != hash + LISTENING_NULLS_BASE)
 		goto begin;
 	if (result) {
+found:
 		if (unlikely(!atomic_inc_not_zero(&result->sk_refcnt)))
 			result = NULL;
 		else if (unlikely(compute_score(result, net, hnum, daddr,
 				  dif) < hiscore)) {
 			sock_put(result);
+			select_ok = false;
 			goto begin;
 		}
 	}
@@ -449,32 +464,74 @@ bool inet_ehash_nolisten(struct sock *sk, struct sock *osk)
 }
 EXPORT_SYMBOL_GPL(inet_ehash_nolisten);
 
-void __inet_hash(struct sock *sk, struct sock *osk)
+static int inet_reuseport_add_sock(struct sock *sk,
+				   struct inet_listen_hashbucket *ilb,
+				   int (*saddr_same)(const struct sock *sk1,
+						     const struct sock *sk2,
+						     bool match_wildcard))
+{
+	struct sock *sk2;
+	struct hlist_nulls_node *node;
+	kuid_t uid = sock_i_uid(sk);
+
+	sk_nulls_for_each_rcu(sk2, node, &ilb->head) {
+		if (sk2 != sk &&
+		    sk2->sk_family == sk->sk_family &&
+		    ipv6_only_sock(sk2) == ipv6_only_sock(sk) &&
+		    sk2->sk_bound_dev_if == sk->sk_bound_dev_if &&
+		    sk2->sk_reuseport && uid_eq(uid, sock_i_uid(sk2)) &&
+		    saddr_same(sk, sk2, false))
+			return reuseport_add_sock(sk, sk2);
+	}
+
+	/* Initial allocation may have already happened via setsockopt */
+	if (!rcu_access_pointer(sk->sk_reuseport_cb))
+		return reuseport_alloc(sk);
+	return 0;
+}
+
+int __inet_hash(struct sock *sk, struct sock *osk,
+		 int (*saddr_same)(const struct sock *sk1,
+				   const struct sock *sk2,
+				   bool match_wildcard))
 {
 	struct inet_hashinfo *hashinfo = sk->sk_prot->h.hashinfo;
 	struct inet_listen_hashbucket *ilb;
+	int err = 0;
 
 	if (sk->sk_state != TCP_LISTEN) {
 		inet_ehash_nolisten(sk, osk);
-		return;
+		return 0;
 	}
 	WARN_ON(!sk_unhashed(sk));
 	ilb = &hashinfo->listening_hash[inet_sk_listen_hashfn(sk)];
 
 	spin_lock(&ilb->lock);
+	if (sk->sk_reuseport) {
+		err = inet_reuseport_add_sock(sk, ilb, saddr_same);
+		if (err)
+			goto unlock;
+	}
 	__sk_nulls_add_node_rcu(sk, &ilb->head);
 	sock_prot_inuse_add(sock_net(sk), sk->sk_prot, 1);
+unlock:
 	spin_unlock(&ilb->lock);
+
+	return err;
 }
 EXPORT_SYMBOL(__inet_hash);
 
-void inet_hash(struct sock *sk)
+int inet_hash(struct sock *sk)
 {
+	int err = 0;
+
 	if (sk->sk_state != TCP_CLOSE) {
 		local_bh_disable();
-		__inet_hash(sk, NULL);
+		err = __inet_hash(sk, NULL, ipv4_rcv_saddr_equal);
 		local_bh_enable();
 	}
+
+	return err;
 }
 EXPORT_SYMBOL_GPL(inet_hash);
 
@@ -493,6 +550,8 @@ void inet_unhash(struct sock *sk)
 		lock = inet_ehash_lockp(hashinfo, sk->sk_hash);
 
 	spin_lock_bh(lock);
+	if (rcu_access_pointer(sk->sk_reuseport_cb))
+		reuseport_detach_sock(sk);
 	done = __sk_nulls_del_node_init_rcu(sk);
 	if (done)
 		sock_prot_inuse_add(sock_net(sk), sk->sk_prot, -1);
diff --git a/net/ipv4/ping.c b/net/ipv4/ping.c
index c117b21b937d..f6f93fc2c61f 100644
--- a/net/ipv4/ping.c
+++ b/net/ipv4/ping.c
@@ -145,10 +145,12 @@ fail:
 }
 EXPORT_SYMBOL_GPL(ping_get_port);
 
-void ping_hash(struct sock *sk)
+int ping_hash(struct sock *sk)
 {
 	pr_debug("ping_hash(sk->port=%u)\n", inet_sk(sk)->inet_num);
 	BUG(); /* "Please do not press this button again." */
+
+	return 0;
 }
 
 void ping_unhash(struct sock *sk)
diff --git a/net/ipv4/raw.c b/net/ipv4/raw.c
index bc35f1842512..d6352515d738 100644
--- a/net/ipv4/raw.c
+++ b/net/ipv4/raw.c
@@ -93,7 +93,7 @@ static struct raw_hashinfo raw_v4_hashinfo = {
 	.lock = __RW_LOCK_UNLOCKED(raw_v4_hashinfo.lock),
 };
 
-void raw_hash_sk(struct sock *sk)
+int raw_hash_sk(struct sock *sk)
 {
 	struct raw_hashinfo *h = sk->sk_prot->h.raw_hash;
 	struct hlist_head *head;
@@ -104,6 +104,8 @@ void raw_hash_sk(struct sock *sk)
 	sk_add_node(sk, head);
 	sock_prot_inuse_add(sock_net(sk), sk->sk_prot, 1);
 	write_unlock_bh(&h->lock);
+
+	return 0;
 }
 EXPORT_SYMBOL_GPL(raw_hash_sk);
 
diff --git a/net/ipv4/tcp_ipv4.c b/net/ipv4/tcp_ipv4.c
index 0d381fa164f8..3f872a6bc274 100644
--- a/net/ipv4/tcp_ipv4.c
+++ b/net/ipv4/tcp_ipv4.c
@@ -637,8 +637,8 @@ static void tcp_v4_send_reset(const struct sock *sk, struct sk_buff *skb)
 		 * Incoming packet is checked with md5 hash with finding key,
 		 * no RST generated if md5 hash doesn't match.
 		 */
-		sk1 = __inet_lookup_listener(net,
-					     &tcp_hashinfo, ip_hdr(skb)->saddr,
+		sk1 = __inet_lookup_listener(net, &tcp_hashinfo, NULL, 0,
+					     ip_hdr(skb)->saddr,
 					     th->source, ip_hdr(skb)->daddr,
 					     ntohs(th->source), inet_iif(skb));
 		/* don't send rst if it can't find key */
@@ -1581,7 +1581,8 @@ int tcp_v4_rcv(struct sk_buff *skb)
 	TCP_SKB_CB(skb)->sacked	 = 0;
 
 lookup:
-	sk = __inet_lookup_skb(&tcp_hashinfo, skb, th->source, th->dest);
+	sk = __inet_lookup_skb(&tcp_hashinfo, skb, __tcp_hdrlen(th), th->source,
+			       th->dest);
 	if (!sk)
 		goto no_tcp_socket;
 
@@ -1695,7 +1696,8 @@ do_time_wait:
 	switch (tcp_timewait_state_process(inet_twsk(sk), skb, th)) {
 	case TCP_TW_SYN: {
 		struct sock *sk2 = inet_lookup_listener(dev_net(skb->dev),
-							&tcp_hashinfo,
+							&tcp_hashinfo, skb,
+							__tcp_hdrlen(th),
 							iph->saddr, th->source,
 							iph->daddr, th->dest,
 							inet_iif(skb));
diff --git a/net/ipv4/udp.c b/net/ipv4/udp.c
index be0b21852b13..ac3cedb25a9f 100644
--- a/net/ipv4/udp.c
+++ b/net/ipv4/udp.c
@@ -356,8 +356,8 @@ EXPORT_SYMBOL(udp_lib_get_port);
  * match_wildcard == false: addresses must be exactly the same, i.e.
  *                          0.0.0.0 only equals to 0.0.0.0
  */
-static int ipv4_rcv_saddr_equal(const struct sock *sk1, const struct sock *sk2,
-				bool match_wildcard)
+int ipv4_rcv_saddr_equal(const struct sock *sk1, const struct sock *sk2,
+			 bool match_wildcard)
 {
 	struct inet_sock *inet1 = inet_sk(sk1), *inet2 = inet_sk(sk2);
 
diff --git a/net/ipv6/af_inet6.c b/net/ipv6/af_inet6.c
index 9f5137cd604e..b11c37cfd67c 100644
--- a/net/ipv6/af_inet6.c
+++ b/net/ipv6/af_inet6.c
@@ -235,7 +235,11 @@ lookup_protocol:
 		 * creation time automatically shares.
 		 */
 		inet->inet_sport = htons(inet->inet_num);
-		sk->sk_prot->hash(sk);
+		err = sk->sk_prot->hash(sk);
+		if (err) {
+			sk_common_release(sk);
+			goto out;
+		}
 	}
 	if (sk->sk_prot->init) {
 		err = sk->sk_prot->init(sk);
diff --git a/net/ipv6/inet6_connection_sock.c b/net/ipv6/inet6_connection_sock.c
index 36c3f0155010..532c3ef282c5 100644
--- a/net/ipv6/inet6_connection_sock.c
+++ b/net/ipv6/inet6_connection_sock.c
@@ -26,6 +26,7 @@
 #include <net/ip6_route.h>
 #include <net/sock.h>
 #include <net/inet6_connection_sock.h>
+#include <net/sock_reuseport.h>
 
 int inet6_csk_bind_conflict(const struct sock *sk,
 			    const struct inet_bind_bucket *tb, bool relax)
@@ -48,6 +49,7 @@ int inet6_csk_bind_conflict(const struct sock *sk,
 			if ((!reuse || !sk2->sk_reuse ||
 			     sk2->sk_state == TCP_LISTEN) &&
 			    (!reuseport || !sk2->sk_reuseport ||
+			     rcu_access_pointer(sk->sk_reuseport_cb) ||
 			     (sk2->sk_state != TCP_TIME_WAIT &&
 			      !uid_eq(uid,
 				      sock_i_uid((struct sock *)sk2))))) {
diff --git a/net/ipv6/inet6_hashtables.c b/net/ipv6/inet6_hashtables.c
index 21ace5a2bf7c..70f2628be6fa 100644
--- a/net/ipv6/inet6_hashtables.c
+++ b/net/ipv6/inet6_hashtables.c
@@ -17,11 +17,13 @@
 #include <linux/module.h>
 #include <linux/random.h>
 
+#include <net/addrconf.h>
 #include <net/inet_connection_sock.h>
 #include <net/inet_hashtables.h>
 #include <net/inet6_hashtables.h>
 #include <net/secure_seq.h>
 #include <net/ip.h>
+#include <net/sock_reuseport.h>
 
 u32 inet6_ehashfn(const struct net *net,
 		  const struct in6_addr *laddr, const u16 lport,
@@ -121,7 +123,9 @@ static inline int compute_score(struct sock *sk, struct net *net,
 }
 
 struct sock *inet6_lookup_listener(struct net *net,
-		struct inet_hashinfo *hashinfo, const struct in6_addr *saddr,
+		struct inet_hashinfo *hashinfo,
+		struct sk_buff *skb, int doff,
+		const struct in6_addr *saddr,
 		const __be16 sport, const struct in6_addr *daddr,
 		const unsigned short hnum, const int dif)
 {
@@ -129,6 +133,7 @@ struct sock *inet6_lookup_listener(struct net *net,
 	const struct hlist_nulls_node *node;
 	struct sock *result;
 	int score, hiscore, matches = 0, reuseport = 0;
+	bool select_ok = true;
 	u32 phash = 0;
 	unsigned int hash = inet_lhashfn(net, hnum);
 	struct inet_listen_hashbucket *ilb = &hashinfo->listening_hash[hash];
@@ -146,6 +151,15 @@ begin:
 			if (reuseport) {
 				phash = inet6_ehashfn(net, daddr, hnum,
 						      saddr, sport);
+				if (select_ok) {
+					struct sock *sk2;
+					sk2 = reuseport_select_sock(sk, phash,
+								    skb, doff);
+					if (sk2) {
+						result = sk2;
+						goto found;
+					}
+				}
 				matches = 1;
 			}
 		} else if (score == hiscore && reuseport) {
@@ -163,11 +177,13 @@ begin:
 	if (get_nulls_value(node) != hash + LISTENING_NULLS_BASE)
 		goto begin;
 	if (result) {
+found:
 		if (unlikely(!atomic_inc_not_zero(&result->sk_refcnt)))
 			result = NULL;
 		else if (unlikely(compute_score(result, net, hnum, daddr,
 				  dif) < hiscore)) {
 			sock_put(result);
+			select_ok = false;
 			goto begin;
 		}
 	}
@@ -177,6 +193,7 @@ begin:
 EXPORT_SYMBOL_GPL(inet6_lookup_listener);
 
 struct sock *inet6_lookup(struct net *net, struct inet_hashinfo *hashinfo,
+			  struct sk_buff *skb, int doff,
 			  const struct in6_addr *saddr, const __be16 sport,
 			  const struct in6_addr *daddr, const __be16 dport,
 			  const int dif)
@@ -184,7 +201,8 @@ struct sock *inet6_lookup(struct net *net, struct inet_hashinfo *hashinfo,
 	struct sock *sk;
 
 	local_bh_disable();
-	sk = __inet6_lookup(net, hashinfo, saddr, sport, daddr, ntohs(dport), dif);
+	sk = __inet6_lookup(net, hashinfo, skb, doff, saddr, sport, daddr,
+			    ntohs(dport), dif);
 	local_bh_enable();
 
 	return sk;
@@ -274,3 +292,59 @@ int inet6_hash_connect(struct inet_timewait_death_row *death_row,
 				   __inet6_check_established);
 }
 EXPORT_SYMBOL_GPL(inet6_hash_connect);
+
+int inet6_hash(struct sock *sk)
+{
+	if (sk->sk_state != TCP_CLOSE) {
+		local_bh_disable();
+		__inet_hash(sk, NULL, ipv6_rcv_saddr_equal);
+		local_bh_enable();
+	}
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(inet6_hash);
+
+/* match_wildcard == true:  IPV6_ADDR_ANY equals to any IPv6 addresses if IPv6
+ *                          only, and any IPv4 addresses if not IPv6 only
+ * match_wildcard == false: addresses must be exactly the same, i.e.
+ *                          IPV6_ADDR_ANY only equals to IPV6_ADDR_ANY,
+ *                          and 0.0.0.0 equals to 0.0.0.0 only
+ */
+int ipv6_rcv_saddr_equal(const struct sock *sk, const struct sock *sk2,
+			 bool match_wildcard)
+{
+	const struct in6_addr *sk2_rcv_saddr6 = inet6_rcv_saddr(sk2);
+	int sk2_ipv6only = inet_v6_ipv6only(sk2);
+	int addr_type = ipv6_addr_type(&sk->sk_v6_rcv_saddr);
+	int addr_type2 = sk2_rcv_saddr6 ? ipv6_addr_type(sk2_rcv_saddr6) : IPV6_ADDR_MAPPED;
+
+	/* if both are mapped, treat as IPv4 */
+	if (addr_type == IPV6_ADDR_MAPPED && addr_type2 == IPV6_ADDR_MAPPED) {
+		if (!sk2_ipv6only) {
+			if (sk->sk_rcv_saddr == sk2->sk_rcv_saddr)
+				return 1;
+			if (!sk->sk_rcv_saddr || !sk2->sk_rcv_saddr)
+				return match_wildcard;
+		}
+		return 0;
+	}
+
+	if (addr_type == IPV6_ADDR_ANY && addr_type2 == IPV6_ADDR_ANY)
+		return 1;
+
+	if (addr_type2 == IPV6_ADDR_ANY && match_wildcard &&
+	    !(sk2_ipv6only && addr_type == IPV6_ADDR_MAPPED))
+		return 1;
+
+	if (addr_type == IPV6_ADDR_ANY && match_wildcard &&
+	    !(ipv6_only_sock(sk) && addr_type2 == IPV6_ADDR_MAPPED))
+		return 1;
+
+	if (sk2_rcv_saddr6 &&
+	    ipv6_addr_equal(&sk->sk_v6_rcv_saddr, sk2_rcv_saddr6))
+		return 1;
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(ipv6_rcv_saddr_equal);
diff --git a/net/ipv6/tcp_ipv6.c b/net/ipv6/tcp_ipv6.c
index 006396e31cb0..9977b6f19f2a 100644
--- a/net/ipv6/tcp_ipv6.c
+++ b/net/ipv6/tcp_ipv6.c
@@ -866,7 +866,8 @@ static void tcp_v6_send_reset(const struct sock *sk, struct sk_buff *skb)
 		 * no RST generated if md5 hash doesn't match.
 		 */
 		sk1 = inet6_lookup_listener(dev_net(skb_dst(skb)->dev),
-					   &tcp_hashinfo, &ipv6h->saddr,
+					   &tcp_hashinfo, NULL, 0,
+					   &ipv6h->saddr,
 					   th->source, &ipv6h->daddr,
 					   ntohs(th->source), tcp_v6_iif(skb));
 		if (!sk1)
@@ -1375,8 +1376,8 @@ static int tcp_v6_rcv(struct sk_buff *skb)
 	hdr = ipv6_hdr(skb);
 
 lookup:
-	sk = __inet6_lookup_skb(&tcp_hashinfo, skb, th->source, th->dest,
-				inet6_iif(skb));
+	sk = __inet6_lookup_skb(&tcp_hashinfo, skb, __tcp_hdrlen(th),
+				th->source, th->dest, inet6_iif(skb));
 	if (!sk)
 		goto no_tcp_socket;
 
@@ -1500,6 +1501,7 @@ do_time_wait:
 		struct sock *sk2;
 
 		sk2 = inet6_lookup_listener(dev_net(skb->dev), &tcp_hashinfo,
+					    skb, __tcp_hdrlen(th),
 					    &ipv6_hdr(skb)->saddr, th->source,
 					    &ipv6_hdr(skb)->daddr,
 					    ntohs(th->dest), tcp_v6_iif(skb));
@@ -1865,7 +1867,7 @@ struct proto tcpv6_prot = {
 	.sendpage		= tcp_sendpage,
 	.backlog_rcv		= tcp_v6_do_rcv,
 	.release_cb		= tcp_release_cb,
-	.hash			= inet_hash,
+	.hash			= inet6_hash,
 	.unhash			= inet_unhash,
 	.get_port		= inet_csk_get_port,
 	.enter_memory_pressure	= tcp_enter_memory_pressure,
diff --git a/net/ipv6/udp.c b/net/ipv6/udp.c
index 22e28a44e3c8..ac4e7e03dded 100644
--- a/net/ipv6/udp.c
+++ b/net/ipv6/udp.c
@@ -37,6 +37,7 @@
 #include <linux/slab.h>
 #include <asm/uaccess.h>
 
+#include <net/addrconf.h>
 #include <net/ndisc.h>
 #include <net/protocol.h>
 #include <net/transp_v6.h>
@@ -77,49 +78,6 @@ static u32 udp6_ehashfn(const struct net *net,
 			       udp_ipv6_hash_secret + net_hash_mix(net));
 }
 
-/* match_wildcard == true:  IPV6_ADDR_ANY equals to any IPv6 addresses if IPv6
- *                          only, and any IPv4 addresses if not IPv6 only
- * match_wildcard == false: addresses must be exactly the same, i.e.
- *                          IPV6_ADDR_ANY only equals to IPV6_ADDR_ANY,
- *                          and 0.0.0.0 equals to 0.0.0.0 only
- */
-int ipv6_rcv_saddr_equal(const struct sock *sk, const struct sock *sk2,
-			 bool match_wildcard)
-{
-	const struct in6_addr *sk2_rcv_saddr6 = inet6_rcv_saddr(sk2);
-	int sk2_ipv6only = inet_v6_ipv6only(sk2);
-	int addr_type = ipv6_addr_type(&sk->sk_v6_rcv_saddr);
-	int addr_type2 = sk2_rcv_saddr6 ? ipv6_addr_type(sk2_rcv_saddr6) : IPV6_ADDR_MAPPED;
-
-	/* if both are mapped, treat as IPv4 */
-	if (addr_type == IPV6_ADDR_MAPPED && addr_type2 == IPV6_ADDR_MAPPED) {
-		if (!sk2_ipv6only) {
-			if (sk->sk_rcv_saddr == sk2->sk_rcv_saddr)
-				return 1;
-			if (!sk->sk_rcv_saddr || !sk2->sk_rcv_saddr)
-				return match_wildcard;
-		}
-		return 0;
-	}
-
-	if (addr_type == IPV6_ADDR_ANY && addr_type2 == IPV6_ADDR_ANY)
-		return 1;
-
-	if (addr_type2 == IPV6_ADDR_ANY && match_wildcard &&
-	    !(sk2_ipv6only && addr_type == IPV6_ADDR_MAPPED))
-		return 1;
-
-	if (addr_type == IPV6_ADDR_ANY && match_wildcard &&
-	    !(ipv6_only_sock(sk) && addr_type2 == IPV6_ADDR_MAPPED))
-		return 1;
-
-	if (sk2_rcv_saddr6 &&
-	    ipv6_addr_equal(&sk->sk_v6_rcv_saddr, sk2_rcv_saddr6))
-		return 1;
-
-	return 0;
-}
-
 static u32 udp6_portaddr_hash(const struct net *net,
 			      const struct in6_addr *addr6,
 			      unsigned int port)
diff --git a/net/l2tp/l2tp_ip6.c b/net/l2tp/l2tp_ip6.c
index a2c8747d2936..6b54ff3ff4cb 100644
--- a/net/l2tp/l2tp_ip6.c
+++ b/net/l2tp/l2tp_ip6.c
@@ -25,6 +25,7 @@
 #include <net/udp.h>
 #include <net/inet_common.h>
 #include <net/inet_hashtables.h>
+#include <net/inet6_hashtables.h>
 #include <net/tcp_states.h>
 #include <net/protocol.h>
 #include <net/xfrm.h>
@@ -718,7 +719,7 @@ static struct proto l2tp_ip6_prot = {
 	.sendmsg	   = l2tp_ip6_sendmsg,
 	.recvmsg	   = l2tp_ip6_recvmsg,
 	.backlog_rcv	   = l2tp_ip6_backlog_recv,
-	.hash		   = inet_hash,
+	.hash		   = inet6_hash,
 	.unhash		   = inet_unhash,
 	.obj_size	   = sizeof(struct l2tp_ip6_sock),
 #ifdef CONFIG_COMPAT
diff --git a/net/netfilter/xt_TPROXY.c b/net/netfilter/xt_TPROXY.c
index 3ab591e73ec0..7f4414d26a66 100644
--- a/net/netfilter/xt_TPROXY.c
+++ b/net/netfilter/xt_TPROXY.c
@@ -105,19 +105,24 @@ tproxy_laddr4(struct sk_buff *skb, __be32 user_laddr, __be32 daddr)
  * belonging to established connections going through that one.
  */
 static inline struct sock *
-nf_tproxy_get_sock_v4(struct net *net, const u8 protocol,
+nf_tproxy_get_sock_v4(struct net *net, struct sk_buff *skb, void *hp,
+		      const u8 protocol,
 		      const __be32 saddr, const __be32 daddr,
 		      const __be16 sport, const __be16 dport,
 		      const struct net_device *in,
 		      const enum nf_tproxy_lookup_t lookup_type)
 {
 	struct sock *sk;
+	struct tcphdr *tcph;
 
 	switch (protocol) {
 	case IPPROTO_TCP:
 		switch (lookup_type) {
 		case NFT_LOOKUP_LISTENER:
-			sk = inet_lookup_listener(net, &tcp_hashinfo,
+			tcph = hp;
+			sk = inet_lookup_listener(net, &tcp_hashinfo, skb,
+						    ip_hdrlen(skb) +
+						      __tcp_hdrlen(tcph),
 						    saddr, sport,
 						    daddr, dport,
 						    in->ifindex);
@@ -169,19 +174,23 @@ nf_tproxy_get_sock_v4(struct net *net, const u8 protocol,
 
 #ifdef XT_TPROXY_HAVE_IPV6
 static inline struct sock *
-nf_tproxy_get_sock_v6(struct net *net, const u8 protocol,
+nf_tproxy_get_sock_v6(struct net *net, struct sk_buff *skb, int thoff, void *hp,
+		      const u8 protocol,
 		      const struct in6_addr *saddr, const struct in6_addr *daddr,
 		      const __be16 sport, const __be16 dport,
 		      const struct net_device *in,
 		      const enum nf_tproxy_lookup_t lookup_type)
 {
 	struct sock *sk;
+	struct tcphdr *tcph;
 
 	switch (protocol) {
 	case IPPROTO_TCP:
 		switch (lookup_type) {
 		case NFT_LOOKUP_LISTENER:
-			sk = inet6_lookup_listener(net, &tcp_hashinfo,
+			tcph = hp;
+			sk = inet6_lookup_listener(net, &tcp_hashinfo, skb,
+						   thoff + __tcp_hdrlen(tcph),
 						   saddr, sport,
 						   daddr, ntohs(dport),
 						   in->ifindex);
@@ -267,7 +276,7 @@ tproxy_handle_time_wait4(struct net *net, struct sk_buff *skb,
 		 * to a listener socket if there's one */
 		struct sock *sk2;
 
-		sk2 = nf_tproxy_get_sock_v4(net, iph->protocol,
+		sk2 = nf_tproxy_get_sock_v4(net, skb, hp, iph->protocol,
 					    iph->saddr, laddr ? laddr : iph->daddr,
 					    hp->source, lport ? lport : hp->dest,
 					    skb->dev, NFT_LOOKUP_LISTENER);
@@ -305,7 +314,7 @@ tproxy_tg4(struct net *net, struct sk_buff *skb, __be32 laddr, __be16 lport,
 	 * addresses, this happens if the redirect already happened
 	 * and the current packet belongs to an already established
 	 * connection */
-	sk = nf_tproxy_get_sock_v4(net, iph->protocol,
+	sk = nf_tproxy_get_sock_v4(net, skb, hp, iph->protocol,
 				   iph->saddr, iph->daddr,
 				   hp->source, hp->dest,
 				   skb->dev, NFT_LOOKUP_ESTABLISHED);
@@ -321,7 +330,7 @@ tproxy_tg4(struct net *net, struct sk_buff *skb, __be32 laddr, __be16 lport,
 	else if (!sk)
 		/* no, there's no established connection, check if
 		 * there's a listener on the redirected addr/port */
-		sk = nf_tproxy_get_sock_v4(net, iph->protocol,
+		sk = nf_tproxy_get_sock_v4(net, skb, hp, iph->protocol,
 					   iph->saddr, laddr,
 					   hp->source, lport,
 					   skb->dev, NFT_LOOKUP_LISTENER);
@@ -429,7 +438,7 @@ tproxy_handle_time_wait6(struct sk_buff *skb, int tproto, int thoff,
 		 * to a listener socket if there's one */
 		struct sock *sk2;
 
-		sk2 = nf_tproxy_get_sock_v6(par->net, tproto,
+		sk2 = nf_tproxy_get_sock_v6(par->net, skb, thoff, hp, tproto,
 					    &iph->saddr,
 					    tproxy_laddr6(skb, &tgi->laddr.in6, &iph->daddr),
 					    hp->source,
@@ -472,7 +481,7 @@ tproxy_tg6_v1(struct sk_buff *skb, const struct xt_action_param *par)
 	 * addresses, this happens if the redirect already happened
 	 * and the current packet belongs to an already established
 	 * connection */
-	sk = nf_tproxy_get_sock_v6(par->net, tproto,
+	sk = nf_tproxy_get_sock_v6(par->net, skb, thoff, hp, tproto,
 				   &iph->saddr, &iph->daddr,
 				   hp->source, hp->dest,
 				   par->in, NFT_LOOKUP_ESTABLISHED);
@@ -487,8 +496,8 @@ tproxy_tg6_v1(struct sk_buff *skb, const struct xt_action_param *par)
 	else if (!sk)
 		/* no there's no established connection, check if
 		 * there's a listener on the redirected addr/port */
-		sk = nf_tproxy_get_sock_v6(par->net, tproto,
-					   &iph->saddr, laddr,
+		sk = nf_tproxy_get_sock_v6(par->net, skb, thoff, hp,
+					   tproto, &iph->saddr, laddr,
 					   hp->source, lport,
 					   par->in, NFT_LOOKUP_LISTENER);
 
diff --git a/net/netfilter/xt_socket.c b/net/netfilter/xt_socket.c
index 2ec08f04b816..49d14ecad444 100644
--- a/net/netfilter/xt_socket.c
+++ b/net/netfilter/xt_socket.c
@@ -112,14 +112,15 @@ extract_icmp4_fields(const struct sk_buff *skb,
  *     box.
  */
 static struct sock *
-xt_socket_get_sock_v4(struct net *net, const u8 protocol,
+xt_socket_get_sock_v4(struct net *net, struct sk_buff *skb, const int doff,
+		      const u8 protocol,
 		      const __be32 saddr, const __be32 daddr,
 		      const __be16 sport, const __be16 dport,
 		      const struct net_device *in)
 {
 	switch (protocol) {
 	case IPPROTO_TCP:
-		return __inet_lookup(net, &tcp_hashinfo,
+		return __inet_lookup(net, &tcp_hashinfo, skb, doff,
 				     saddr, sport, daddr, dport,
 				     in->ifindex);
 	case IPPROTO_UDP:
@@ -148,6 +149,8 @@ static struct sock *xt_socket_lookup_slow_v4(struct net *net,
 					     const struct net_device *indev)
 {
 	const struct iphdr *iph = ip_hdr(skb);
+	struct sk_buff *data_skb = NULL;
+	int doff = 0;
 	__be32 uninitialized_var(daddr), uninitialized_var(saddr);
 	__be16 uninitialized_var(dport), uninitialized_var(sport);
 	u8 uninitialized_var(protocol);
@@ -169,6 +172,10 @@ static struct sock *xt_socket_lookup_slow_v4(struct net *net,
 		sport = hp->source;
 		daddr = iph->daddr;
 		dport = hp->dest;
+		data_skb = (struct sk_buff *)skb;
+		doff = iph->protocol == IPPROTO_TCP ?
+			ip_hdrlen(skb) + __tcp_hdrlen((struct tcphdr *)hp) :
+			ip_hdrlen(skb) + sizeof(*hp);
 
 	} else if (iph->protocol == IPPROTO_ICMP) {
 		if (extract_icmp4_fields(skb, &protocol, &saddr, &daddr,
@@ -198,8 +205,8 @@ static struct sock *xt_socket_lookup_slow_v4(struct net *net,
 	}
 #endif
 
-	return xt_socket_get_sock_v4(net, protocol, saddr, daddr,
-				     sport, dport, indev);
+	return xt_socket_get_sock_v4(net, data_skb, doff, protocol, saddr,
+				     daddr, sport, dport, indev);
 }
 
 static bool
@@ -318,14 +325,15 @@ extract_icmp6_fields(const struct sk_buff *skb,
 }
 
 static struct sock *
-xt_socket_get_sock_v6(struct net *net, const u8 protocol,
+xt_socket_get_sock_v6(struct net *net, struct sk_buff *skb, int doff,
+		      const u8 protocol,
 		      const struct in6_addr *saddr, const struct in6_addr *daddr,
 		      const __be16 sport, const __be16 dport,
 		      const struct net_device *in)
 {
 	switch (protocol) {
 	case IPPROTO_TCP:
-		return inet6_lookup(net, &tcp_hashinfo,
+		return inet6_lookup(net, &tcp_hashinfo, skb, doff,
 				    saddr, sport, daddr, dport,
 				    in->ifindex);
 	case IPPROTO_UDP:
@@ -343,6 +351,8 @@ static struct sock *xt_socket_lookup_slow_v6(struct net *net,
 	__be16 uninitialized_var(dport), uninitialized_var(sport);
 	const struct in6_addr *daddr = NULL, *saddr = NULL;
 	struct ipv6hdr *iph = ipv6_hdr(skb);
+	struct sk_buff *data_skb = NULL;
+	int doff = 0;
 	int thoff = 0, tproto;
 
 	tproto = ipv6_find_hdr(skb, &thoff, -1, NULL, NULL);
@@ -362,6 +372,10 @@ static struct sock *xt_socket_lookup_slow_v6(struct net *net,
 		sport = hp->source;
 		daddr = &iph->daddr;
 		dport = hp->dest;
+		data_skb = (struct sk_buff *)skb;
+		doff = tproto == IPPROTO_TCP ?
+			thoff + __tcp_hdrlen((struct tcphdr *)hp) :
+			thoff + sizeof(*hp);
 
 	} else if (tproto == IPPROTO_ICMPV6) {
 		struct ipv6hdr ipv6_var;
@@ -373,7 +387,7 @@ static struct sock *xt_socket_lookup_slow_v6(struct net *net,
 		return NULL;
 	}
 
-	return xt_socket_get_sock_v6(net, tproto, saddr, daddr,
+	return xt_socket_get_sock_v6(net, data_skb, doff, tproto, saddr, daddr,
 				     sport, dport, indev);
 }
 
diff --git a/net/phonet/socket.c b/net/phonet/socket.c
index d575ef4e9aa6..ffd5f2297584 100644
--- a/net/phonet/socket.c
+++ b/net/phonet/socket.c
@@ -140,13 +140,15 @@ void pn_deliver_sock_broadcast(struct net *net, struct sk_buff *skb)
 	rcu_read_unlock();
 }
 
-void pn_sock_hash(struct sock *sk)
+int pn_sock_hash(struct sock *sk)
 {
 	struct hlist_head *hlist = pn_hash_list(pn_sk(sk)->sobject);
 
 	mutex_lock(&pnsocks.lock);
 	sk_add_node_rcu(sk, hlist);
 	mutex_unlock(&pnsocks.lock);
+
+	return 0;
 }
 EXPORT_SYMBOL(pn_sock_hash);
 
@@ -200,7 +202,7 @@ static int pn_socket_bind(struct socket *sock, struct sockaddr *addr, int len)
 	pn->resource = spn->spn_resource;
 
 	/* Enable RX on the socket */
-	sk->sk_prot->hash(sk);
+	err = sk->sk_prot->hash(sk);
 out_port:
 	mutex_unlock(&port_mutex);
 out:
diff --git a/net/sctp/socket.c b/net/sctp/socket.c
index 5ca2ebfe0be8..6427b9d1197e 100644
--- a/net/sctp/socket.c
+++ b/net/sctp/socket.c
@@ -6101,9 +6101,10 @@ static int sctp_getsockopt(struct sock *sk, int level, int optname,
 	return retval;
 }
 
-static void sctp_hash(struct sock *sk)
+static int sctp_hash(struct sock *sk)
 {
 	/* STUB */
+	return 0;
 }
 
 static void sctp_unhash(struct sock *sk)