Revert "net: Add a second bind table hashed by port and address"

This reverts:

commit d5a42de8 ("net: Add a second bind table hashed by port and address")
commit 538aaf9b ("selftests: Add test for timing a bind request to a port with a populated bhash entry")
Link: https://lore.kernel.org/netdev/20220520001834.2247810-1-kuba@kernel.org/

There are a few things that need to be fixed here:
* Updating bhash2 in cases where the socket's rcv saddr changes
* Adding bhash2 hashbucket locks

Links to syzbot reports:
https://lore.kernel.org/netdev/00000000000022208805e0df247a@google.com/
https://lore.kernel.org/netdev/0000000000003f33bc05dfaf44fe@google.com/

Fixes: d5a42de8 ("net: Add a second bind table hashed by port and address")
Reported-by: syzbot+015d756bbd1f8b5c8f09@syzkaller.appspotmail.com
Reported-by: syzbot+98fd2d1422063b0f8c44@syzkaller.appspotmail.com
Reported-by: syzbot+0a847a982613c6438fba@syzkaller.appspotmail.com
Signed-off-by: Joanne Koong <joannelkoong@gmail.com>
Link: https://lore.kernel.org/r/20220615193213.2419568-1-joannelkoong@gmail.comSigned-off-by: Jakub Kicinski <kuba@kernel.org>

include/net/inet_connection_sock.h

@@ -25,7 +25,6 @@
 #undef INET_CSK_CLEAR_TIMERS
 
 struct inet_bind_bucket;
-struct inet_bind2_bucket;
 struct tcp_congestion_ops;
 
 /*
@@ -58,7 +57,6 @@ struct inet_connection_sock_af_ops {
  *
  * @icsk_accept_queue:	   FIFO of established children
  * @icsk_bind_hash:	   Bind node
- * @icsk_bind2_hash:	   Bind node in the bhash2 table
  * @icsk_timeout:	   Timeout
  * @icsk_retransmit_timer: Resend (no ack)
  * @icsk_rto:		   Retransmit timeout
@@ -85,7 +83,6 @@ struct inet_connection_sock {
 	struct inet_sock	  icsk_inet;
 	struct request_sock_queue icsk_accept_queue;
 	struct inet_bind_bucket	  *icsk_bind_hash;
-	struct inet_bind2_bucket  *icsk_bind2_hash;
 	unsigned long		  icsk_timeout;
  	struct timer_list	  icsk_retransmit_timer;
  	struct timer_list	  icsk_delack_timer;

include/net/inet_hashtables.h

@@ -90,32 +90,11 @@ struct inet_bind_bucket {
 	struct hlist_head	owners;
 };
 
-struct inet_bind2_bucket {
-	possible_net_t		ib_net;
-	int			l3mdev;
-	unsigned short		port;
-	union {
-#if IS_ENABLED(CONFIG_IPV6)
-		struct in6_addr		v6_rcv_saddr;
-#endif
-		__be32			rcv_saddr;
-	};
-	/* Node in the inet2_bind_hashbucket chain */
-	struct hlist_node	node;
-	/* List of sockets hashed to this bucket */
-	struct hlist_head	owners;
-};
-
 static inline struct net *ib_net(struct inet_bind_bucket *ib)
 {
 	return read_pnet(&ib->ib_net);
 }
 
-static inline struct net *ib2_net(struct inet_bind2_bucket *ib)
-{
-	return read_pnet(&ib->ib_net);
-}
-
 #define inet_bind_bucket_for_each(tb, head) \
 	hlist_for_each_entry(tb, head, node)
 
@@ -124,15 +103,6 @@ struct inet_bind_hashbucket {
 	struct hlist_head	chain;
 };
 
-/* This is synchronized using the inet_bind_hashbucket's spinlock.
- * Instead of having separate spinlocks, the inet_bind2_hashbucket can share
- * the inet_bind_hashbucket's given that in every case where the bhash2 table
- * is useful, a lookup in the bhash table also occurs.
- */
-struct inet_bind2_hashbucket {
-	struct hlist_head	chain;
-};
-
 /* Sockets can be hashed in established or listening table.
  * We must use different 'nulls' end-of-chain value for all hash buckets :
  * A socket might transition from ESTABLISH to LISTEN state without
@@ -164,12 +134,6 @@ struct inet_hashinfo {
 	 */
 	struct kmem_cache		*bind_bucket_cachep;
 	struct inet_bind_hashbucket	*bhash;
-	/* The 2nd binding table hashed by port and address.
-	 * This is used primarily for expediting the resolution of bind
-	 * conflicts.
-	 */
-	struct kmem_cache		*bind2_bucket_cachep;
-	struct inet_bind2_hashbucket	*bhash2;
 	unsigned int			bhash_size;
 
 	/* The 2nd listener table hashed by local port and address */
@@ -229,36 +193,6 @@ inet_bind_bucket_create(struct kmem_cache *cachep, struct net *net,
 void inet_bind_bucket_destroy(struct kmem_cache *cachep,
 			      struct inet_bind_bucket *tb);
 
-static inline bool check_bind_bucket_match(struct inet_bind_bucket *tb,
-					   struct net *net,
-					   const unsigned short port,
-					   int l3mdev)
-{
-	return net_eq(ib_net(tb), net) && tb->port == port &&
-		tb->l3mdev == l3mdev;
-}
-
-struct inet_bind2_bucket *
-inet_bind2_bucket_create(struct kmem_cache *cachep, struct net *net,
-			 struct inet_bind2_hashbucket *head,
-			 const unsigned short port, int l3mdev,
-			 const struct sock *sk);
-
-void inet_bind2_bucket_destroy(struct kmem_cache *cachep,
-			       struct inet_bind2_bucket *tb);
-
-struct inet_bind2_bucket *
-inet_bind2_bucket_find(struct inet_hashinfo *hinfo, struct net *net,
-		       const unsigned short port, int l3mdev,
-		       struct sock *sk,
-		       struct inet_bind2_hashbucket **head);
-
-bool check_bind2_bucket_match_nulladdr(struct inet_bind2_bucket *tb,
-				       struct net *net,
-				       const unsigned short port,
-				       int l3mdev,
-				       const struct sock *sk);
-
 static inline u32 inet_bhashfn(const struct net *net, const __u16 lport,
 			       const u32 bhash_size)
 {
@@ -266,7 +200,7 @@ static inline u32 inet_bhashfn(const struct net *net, const __u16 lport,
 }
 
 void inet_bind_hash(struct sock *sk, struct inet_bind_bucket *tb,
-		    struct inet_bind2_bucket *tb2, const unsigned short snum);
+		    const unsigned short snum);
 
 /* Caller must disable local BH processing. */
 int __inet_inherit_port(const struct sock *sk, struct sock *child);

include/net/sock.h

@@ -348,7 +348,6 @@ struct sk_filter;
   *	@sk_txtime_report_errors: set report errors mode for SO_TXTIME
   *	@sk_txtime_unused: unused txtime flags
   *	@ns_tracker: tracker for netns reference
-  *	@sk_bind2_node: bind node in the bhash2 table
   */
 struct sock {
 	/*
@@ -538,7 +537,6 @@ struct sock {
 #endif
 	struct rcu_head		sk_rcu;
 	netns_tracker		ns_tracker;
-	struct hlist_node	sk_bind2_node;
 };
 
 enum sk_pacing {
@@ -819,16 +817,6 @@ static inline void sk_add_bind_node(struct sock *sk,
 	hlist_add_head(&sk->sk_bind_node, list);
 }
 
-static inline void __sk_del_bind2_node(struct sock *sk)
-{
-	__hlist_del(&sk->sk_bind2_node);
-}
-
-static inline void sk_add_bind2_node(struct sock *sk, struct hlist_head *list)
-{
-	hlist_add_head(&sk->sk_bind2_node, list);
-}
-
 #define sk_for_each(__sk, list) \
 	hlist_for_each_entry(__sk, list, sk_node)
 #define sk_for_each_rcu(__sk, list) \
@@ -846,8 +834,6 @@ static inline void sk_add_bind2_node(struct sock *sk, struct hlist_head *list)
 	hlist_for_each_entry_safe(__sk, tmp, list, sk_node)
 #define sk_for_each_bound(__sk, list) \
 	hlist_for_each_entry(__sk, list, sk_bind_node)
-#define sk_for_each_bound_bhash2(__sk, list) \
-	hlist_for_each_entry(__sk, list, sk_bind2_node)
 
 /**
  * sk_for_each_entry_offset_rcu - iterate over a list at a given struct offset

net/dccp/proto.c

@@ -1120,12 +1120,6 @@ static int __init dccp_init(void)
 				  SLAB_HWCACHE_ALIGN | SLAB_ACCOUNT, NULL);
 	if (!dccp_hashinfo.bind_bucket_cachep)
 		goto out_free_hashinfo2;
-	dccp_hashinfo.bind2_bucket_cachep =
-		kmem_cache_create("dccp_bind2_bucket",
-				  sizeof(struct inet_bind2_bucket), 0,
-				  SLAB_HWCACHE_ALIGN | SLAB_ACCOUNT, NULL);
-	if (!dccp_hashinfo.bind2_bucket_cachep)
-		goto out_free_bind_bucket_cachep;
 
 	/*
 	 * Size and allocate the main established and bind bucket
@@ -1156,7 +1150,7 @@ static int __init dccp_init(void)
 
 	if (!dccp_hashinfo.ehash) {
 		DCCP_CRIT("Failed to allocate DCCP established hash table");
-		goto out_free_bind2_bucket_cachep;
+		goto out_free_bind_bucket_cachep;
 	}
 
 	for (i = 0; i <= dccp_hashinfo.ehash_mask; i++)
@@ -1182,23 +1176,14 @@ static int __init dccp_init(void)
 		goto out_free_dccp_locks;
 	}
 
-	dccp_hashinfo.bhash2 = (struct inet_bind2_hashbucket *)
-		__get_free_pages(GFP_ATOMIC | __GFP_NOWARN, bhash_order);
-
-	if (!dccp_hashinfo.bhash2) {
-		DCCP_CRIT("Failed to allocate DCCP bind2 hash table");
-		goto out_free_dccp_bhash;
-	}
-
 	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);
-		INIT_HLIST_HEAD(&dccp_hashinfo.bhash2[i].chain);
 	}
 
 	rc = dccp_mib_init();
 	if (rc)
-		goto out_free_dccp_bhash2;
+		goto out_free_dccp_bhash;
 
 	rc = dccp_ackvec_init();
 	if (rc)
@@ -1222,38 +1207,30 @@ static int __init dccp_init(void)
 	dccp_ackvec_exit();
 out_free_dccp_mib:
 	dccp_mib_exit();
-out_free_dccp_bhash2:
-	free_pages((unsigned long)dccp_hashinfo.bhash2, bhash_order);
 out_free_dccp_bhash:
 	free_pages((unsigned long)dccp_hashinfo.bhash, bhash_order);
 out_free_dccp_locks:
 	inet_ehash_locks_free(&dccp_hashinfo);
 out_free_dccp_ehash:
 	free_pages((unsigned long)dccp_hashinfo.ehash, ehash_order);
-out_free_bind2_bucket_cachep:
-	kmem_cache_destroy(dccp_hashinfo.bind2_bucket_cachep);
 out_free_bind_bucket_cachep:
 	kmem_cache_destroy(dccp_hashinfo.bind_bucket_cachep);
 out_free_hashinfo2:
 	inet_hashinfo2_free_mod(&dccp_hashinfo);
 out_fail:
 	dccp_hashinfo.bhash = NULL;
-	dccp_hashinfo.bhash2 = NULL;
 	dccp_hashinfo.ehash = NULL;
 	dccp_hashinfo.bind_bucket_cachep = NULL;
-	dccp_hashinfo.bind2_bucket_cachep = NULL;
 	return rc;
 }
 
 static void __exit dccp_fini(void)
 {
-	int bhash_order = get_order(dccp_hashinfo.bhash_size *
-				    sizeof(struct inet_bind_hashbucket));
-
 	ccid_cleanup_builtins();
 	dccp_mib_exit();
-	free_pages((unsigned long)dccp_hashinfo.bhash, bhash_order);
-	free_pages((unsigned long)dccp_hashinfo.bhash2, bhash_order);
+	free_pages((unsigned long)dccp_hashinfo.bhash,
+		   get_order(dccp_hashinfo.bhash_size *
+			     sizeof(struct inet_bind_hashbucket)));
 	free_pages((unsigned long)dccp_hashinfo.ehash,
 		   get_order((dccp_hashinfo.ehash_mask + 1) *
 			     sizeof(struct inet_ehash_bucket)));

net/ipv4/inet_connection_sock.c

@@ -117,32 +117,6 @@ bool inet_rcv_saddr_any(const struct sock *sk)
 	return !sk->sk_rcv_saddr;
 }
 
-static bool use_bhash2_on_bind(const struct sock *sk)
-{
-#if IS_ENABLED(CONFIG_IPV6)
-	int addr_type;
-
-	if (sk->sk_family == AF_INET6) {
-		addr_type = ipv6_addr_type(&sk->sk_v6_rcv_saddr);
-		return addr_type != IPV6_ADDR_ANY &&
-			addr_type != IPV6_ADDR_MAPPED;
-	}
-#endif
-	return sk->sk_rcv_saddr != htonl(INADDR_ANY);
-}
-
-static u32 get_bhash2_nulladdr_hash(const struct sock *sk, struct net *net,
-				    int port)
-{
-#if IS_ENABLED(CONFIG_IPV6)
-	struct in6_addr nulladdr = {};
-
-	if (sk->sk_family == AF_INET6)
-		return ipv6_portaddr_hash(net, &nulladdr, port);
-#endif
-	return ipv4_portaddr_hash(net, 0, port);
-}
-
 void inet_get_local_port_range(struct net *net, int *low, int *high)
 {
 	unsigned int seq;
@@ -156,71 +130,16 @@ void inet_get_local_port_range(struct net *net, int *low, int *high)
 }
 EXPORT_SYMBOL(inet_get_local_port_range);
 
-static bool bind_conflict_exist(const struct sock *sk, struct sock *sk2,
-				kuid_t sk_uid, bool relax,
-				bool reuseport_cb_ok, bool reuseport_ok)
-{
-	int bound_dev_if2;
-
-	if (sk == sk2)
-		return false;
-
-	bound_dev_if2 = READ_ONCE(sk2->sk_bound_dev_if);
-
-	if (!sk->sk_bound_dev_if || !bound_dev_if2 ||
-	    sk->sk_bound_dev_if == bound_dev_if2) {
-		if (sk->sk_reuse && sk2->sk_reuse &&
-		    sk2->sk_state != TCP_LISTEN) {
-			if (!relax || (!reuseport_ok && sk->sk_reuseport &&
-				       sk2->sk_reuseport && reuseport_cb_ok &&
-				       (sk2->sk_state == TCP_TIME_WAIT ||
-					uid_eq(sk_uid, sock_i_uid(sk2)))))
-				return true;
-		} else if (!reuseport_ok || !sk->sk_reuseport ||
-			   !sk2->sk_reuseport || !reuseport_cb_ok ||
-			   (sk2->sk_state != TCP_TIME_WAIT &&
-			    !uid_eq(sk_uid, sock_i_uid(sk2)))) {
-			return true;
-		}
-	}
-	return false;
-}
-
-static bool check_bhash2_conflict(const struct sock *sk,
-				  struct inet_bind2_bucket *tb2, kuid_t sk_uid,
-				  bool relax, bool reuseport_cb_ok,
-				  bool reuseport_ok)
-{
-	struct sock *sk2;
-
-	sk_for_each_bound_bhash2(sk2, &tb2->owners) {
-		if (sk->sk_family == AF_INET && ipv6_only_sock(sk2))
-			continue;
-
-		if (bind_conflict_exist(sk, sk2, sk_uid, relax,
-					reuseport_cb_ok, reuseport_ok))
-			return true;
-	}
-	return false;
-}
-
-/* This should be called only when the corresponding inet_bind_bucket spinlock
- * is held
- */
-static int inet_csk_bind_conflict(const struct sock *sk, int port,
-				  struct inet_bind_bucket *tb,
-				  struct inet_bind2_bucket *tb2, /* may be null */
+static int inet_csk_bind_conflict(const struct sock *sk,
+				  const struct inet_bind_bucket *tb,
 				  bool relax, bool reuseport_ok)
 {
-	struct inet_hashinfo *hinfo = sk->sk_prot->h.hashinfo;
-	kuid_t uid = sock_i_uid((struct sock *)sk);
-	struct sock_reuseport *reuseport_cb;
-	struct inet_bind2_hashbucket *head2;
-	bool reuseport_cb_ok;
 	struct sock *sk2;
-	struct net *net;
-	int l3mdev;
-	u32 hash;
+	bool reuseport_cb_ok;
+	bool reuse = sk->sk_reuse;
+	bool reuseport = !!sk->sk_reuseport;
+	struct sock_reuseport *reuseport_cb;
+	kuid_t uid = sock_i_uid((struct sock *)sk);
 
 	rcu_read_lock();
 	reuseport_cb = rcu_dereference(sk->sk_reuseport_cb);
@@ -231,42 +150,40 @@ static int inet_csk_bind_conflict(const struct sock *sk, int port,
 	/*
 	 * Unlike other sk lookup places we do not check
 	 * for sk_net here, since _all_ the socks listed
-	 * in tb->owners and tb2->owners list belong
-	 * to the same net
+	 * in tb->owners list belong to the same net - the
+	 * one this bucket belongs to.
 	 */
 
-	if (!use_bhash2_on_bind(sk)) {
-		sk_for_each_bound(sk2, &tb->owners)
-			if (bind_conflict_exist(sk, sk2, uid, relax,
-						reuseport_cb_ok, reuseport_ok) &&
-			    inet_rcv_saddr_equal(sk, sk2, true))
-				return true;
+	sk_for_each_bound(sk2, &tb->owners) {
+		int bound_dev_if2;
 
-		return false;
+		if (sk == sk2)
+			continue;
+		bound_dev_if2 = READ_ONCE(sk2->sk_bound_dev_if);
+		if ((!sk->sk_bound_dev_if ||
+		     !bound_dev_if2 ||
+		     sk->sk_bound_dev_if == bound_dev_if2)) {
+			if (reuse && sk2->sk_reuse &&
+			    sk2->sk_state != TCP_LISTEN) {
+				if ((!relax ||
+				     (!reuseport_ok &&
+				      reuseport && sk2->sk_reuseport &&
+				      reuseport_cb_ok &&
+				      (sk2->sk_state == TCP_TIME_WAIT ||
+				       uid_eq(uid, sock_i_uid(sk2))))) &&
+				    inet_rcv_saddr_equal(sk, sk2, true))
+					break;
+			} else if (!reuseport_ok ||
+				   !reuseport || !sk2->sk_reuseport ||
+				   !reuseport_cb_ok ||
+				   (sk2->sk_state != TCP_TIME_WAIT &&
+				    !uid_eq(uid, sock_i_uid(sk2)))) {
+				if (inet_rcv_saddr_equal(sk, sk2, true))
+					break;
+			}
+		}
 	}
-
-	if (tb2 && check_bhash2_conflict(sk, tb2, uid, relax, reuseport_cb_ok,
-					 reuseport_ok))
-		return true;
-
-	net = sock_net(sk);
-
-	/* check there's no conflict with an existing IPV6_ADDR_ANY (if ipv6) or
-	 * INADDR_ANY (if ipv4) socket.
-	 */
-	hash = get_bhash2_nulladdr_hash(sk, net, port);
-	head2 = &hinfo->bhash2[hash & (hinfo->bhash_size - 1)];
-
-	l3mdev = inet_sk_bound_l3mdev(sk);
-	inet_bind_bucket_for_each(tb2, &head2->chain)
-		if (check_bind2_bucket_match_nulladdr(tb2, net, port, l3mdev, sk))
-			break;
-
-	if (tb2 && check_bhash2_conflict(sk, tb2, uid, relax, reuseport_cb_ok,
-					 reuseport_ok))
-		return true;
-
-	return false;
+	return sk2 != NULL;
 }
 
 /*
@@ -274,20 +191,16 @@ static int inet_csk_bind_conflict(const struct sock *sk, int port,
  * inet_bind_hashbucket lock held.
  */
 static struct inet_bind_hashbucket *
-inet_csk_find_open_port(struct sock *sk, struct inet_bind_bucket **tb_ret,
-			struct inet_bind2_bucket **tb2_ret,
-			struct inet_bind2_hashbucket **head2_ret, int *port_ret)
+inet_csk_find_open_port(struct sock *sk, struct inet_bind_bucket **tb_ret, int *port_ret)
 {
 	struct inet_hashinfo *hinfo = sk->sk_prot->h.hashinfo;
-	struct inet_bind2_hashbucket *head2;
+	int port = 0;
 	struct inet_bind_hashbucket *head;
 	struct net *net = sock_net(sk);
+	bool relax = false;
 	int i, low, high, attempt_half;
-	struct inet_bind2_bucket *tb2;
 	struct inet_bind_bucket *tb;
 	u32 remaining, offset;
-	bool relax = false;
-	int port = 0;
 	int l3mdev;
 
 	l3mdev = inet_sk_bound_l3mdev(sk);
@@ -326,12 +239,10 @@ inet_csk_find_open_port(struct sock *sk, struct inet_bind_bucket **tb_ret,
 		head = &hinfo->bhash[inet_bhashfn(net, port,
 						  hinfo->bhash_size)];
 		spin_lock_bh(&head->lock);
-		tb2 = inet_bind2_bucket_find(hinfo, net, port, l3mdev, sk,
-					     &head2);
 		inet_bind_bucket_for_each(tb, &head->chain)
-			if (check_bind_bucket_match(tb, net, port, l3mdev)) {
-				if (!inet_csk_bind_conflict(sk, port, tb, tb2,
-							    relax, false))
+			if (net_eq(ib_net(tb), net) && tb->l3mdev == l3mdev &&
+			    tb->port == port) {
+				if (!inet_csk_bind_conflict(sk, tb, relax, false))
 					goto success;
 				goto next_port;
 			}
@@ -361,8 +272,6 @@ inet_csk_find_open_port(struct sock *sk, struct inet_bind_bucket **tb_ret,
 success:
 	*port_ret = port;
 	*tb_ret = tb;
-	*tb2_ret = tb2;
-	*head2_ret = head2;
 	return head;
 }
 
@@ -458,81 +367,54 @@ int inet_csk_get_port(struct sock *sk, unsigned short snum)
 {
 	bool reuse = sk->sk_reuse && sk->sk_state != TCP_LISTEN;
 	struct inet_hashinfo *hinfo = sk->sk_prot->h.hashinfo;
-	bool bhash_created = false, bhash2_created = false;
-	struct inet_bind2_bucket *tb2 = NULL;
-	struct inet_bind2_hashbucket *head2;
-	struct inet_bind_bucket *tb = NULL;
+	int ret = 1, port = snum;
 	struct inet_bind_hashbucket *head;
 	struct net *net = sock_net(sk);
-	int ret = 1, port = snum;
-	bool found_port = false;
+	struct inet_bind_bucket *tb = NULL;
 	int l3mdev;
 
 	l3mdev = inet_sk_bound_l3mdev(sk);
 
 	if (!port) {
-		head = inet_csk_find_open_port(sk, &tb, &tb2, &head2, &port);
+		head = inet_csk_find_open_port(sk, &tb, &port);
 		if (!head)
 			return ret;
-		if (tb && tb2)
-			goto success;
-		found_port = true;
-	} else {
-		head = &hinfo->bhash[inet_bhashfn(net, port,
-						  hinfo->bhash_size)];
-		spin_lock_bh(&head->lock);
-		inet_bind_bucket_for_each(tb, &head->chain)
-			if (check_bind_bucket_match(tb, net, port, l3mdev))
-				break;
-
-		tb2 = inet_bind2_bucket_find(hinfo, net, port, l3mdev, sk,
-					     &head2);
-	}
-
-	if (!tb) {
-		tb = inet_bind_bucket_create(hinfo->bind_bucket_cachep, net,
-					     head, port, l3mdev);
 		if (!tb)
-			goto fail_unlock;
-		bhash_created = true;
-	}
-
-	if (!tb2) {
-		tb2 = inet_bind2_bucket_create(hinfo->bind2_bucket_cachep,
-					       net, head2, port, l3mdev, sk);
-		if (!tb2)
-			goto fail_unlock;
-		bhash2_created = true;
+			goto tb_not_found;
+		goto success;
 	}
-
-	/* If we had to find an open port, we already checked for conflicts */
-	if (!found_port && !hlist_empty(&tb->owners)) {
+	head = &hinfo->bhash[inet_bhashfn(net, port,
+					  hinfo->bhash_size)];
+	spin_lock_bh(&head->lock);
+	inet_bind_bucket_for_each(tb, &head->chain)
+		if (net_eq(ib_net(tb), net) && tb->l3mdev == l3mdev &&
+		    tb->port == port)
+			goto tb_found;
+tb_not_found:
+	tb = inet_bind_bucket_create(hinfo->bind_bucket_cachep,
+				     net, head, port, l3mdev);
+	if (!tb)
+		goto fail_unlock;
+tb_found:
+	if (!hlist_empty(&tb->owners)) {
 		if (sk->sk_reuse == SK_FORCE_REUSE)
 			goto success;
 
 		if ((tb->fastreuse > 0 && reuse) ||
 		    sk_reuseport_match(tb, sk))
 			goto success;
-		if (inet_csk_bind_conflict(sk, port, tb, tb2, true, true))
+		if (inet_csk_bind_conflict(sk, tb, true, true))
 			goto fail_unlock;
 	}
 success:
 	inet_csk_update_fastreuse(tb, sk);
 
 	if (!inet_csk(sk)->icsk_bind_hash)
-		inet_bind_hash(sk, tb, tb2, port);
+		inet_bind_hash(sk, tb, port);
 	WARN_ON(inet_csk(sk)->icsk_bind_hash != tb);
-	WARN_ON(inet_csk(sk)->icsk_bind2_hash != tb2);
 	ret = 0;
 
 fail_unlock:
-	if (ret) {
-		if (bhash_created)
-			inet_bind_bucket_destroy(hinfo->bind_bucket_cachep, tb);
-		if (bhash2_created)
-			inet_bind2_bucket_destroy(hinfo->bind2_bucket_cachep,
-						  tb2);
-	}
 	spin_unlock_bh(&head->lock);
 	return ret;
 }
@@ -1079,7 +961,6 @@ struct sock *inet_csk_clone_lock(const struct sock *sk,
 
 		inet_sk_set_state(newsk, TCP_SYN_RECV);
 		newicsk->icsk_bind_hash = NULL;
-		newicsk->icsk_bind2_hash = NULL;
 
 		inet_sk(newsk)->inet_dport = inet_rsk(req)->ir_rmt_port;
 		inet_sk(newsk)->inet_num = inet_rsk(req)->ir_num;

net/ipv4/inet_hashtables.c

@@ -81,41 +81,6 @@ struct inet_bind_bucket *inet_bind_bucket_create(struct kmem_cache *cachep,
 	return tb;
 }
 
-struct inet_bind2_bucket *inet_bind2_bucket_create(struct kmem_cache *cachep,
-						   struct net *net,
-						   struct inet_bind2_hashbucket *head,
-						   const unsigned short port,
-						   int l3mdev,
-						   const struct sock *sk)
-{
-	struct inet_bind2_bucket *tb = kmem_cache_alloc(cachep, GFP_ATOMIC);
-
-	if (tb) {
-		write_pnet(&tb->ib_net, net);
-		tb->l3mdev    = l3mdev;
-		tb->port      = port;
-#if IS_ENABLED(CONFIG_IPV6)
-		if (sk->sk_family == AF_INET6)
-			tb->v6_rcv_saddr = sk->sk_v6_rcv_saddr;
-		else
-#endif
-			tb->rcv_saddr = sk->sk_rcv_saddr;
-		INIT_HLIST_HEAD(&tb->owners);
-		hlist_add_head(&tb->node, &head->chain);
-	}
-	return tb;
-}
-
-static bool bind2_bucket_addr_match(struct inet_bind2_bucket *tb2, struct sock *sk)
-{
-#if IS_ENABLED(CONFIG_IPV6)
-	if (sk->sk_family == AF_INET6)
-		return ipv6_addr_equal(&tb2->v6_rcv_saddr,
-				       &sk->sk_v6_rcv_saddr);
-#endif
-	return tb2->rcv_saddr == sk->sk_rcv_saddr;
-}
-
 /*
  * Caller must hold hashbucket lock for this tb with local BH disabled
  */
@@ -127,25 +92,12 @@ void inet_bind_bucket_destroy(struct kmem_cache *cachep, struct inet_bind_bucket
 	}
 }
 
-/* Caller must hold the lock for the corresponding hashbucket in the bhash table
- * with local BH disabled
- */
-void inet_bind2_bucket_destroy(struct kmem_cache *cachep, struct inet_bind2_bucket *tb)
-{
-	if (hlist_empty(&tb->owners)) {
-		__hlist_del(&tb->node);
-		kmem_cache_free(cachep, tb);
-	}
-}
-
 void inet_bind_hash(struct sock *sk, struct inet_bind_bucket *tb,
-		    struct inet_bind2_bucket *tb2, const unsigned short snum)
+		    const unsigned short snum)
 {
 	inet_sk(sk)->inet_num = snum;
 	sk_add_bind_node(sk, &tb->owners);
 	inet_csk(sk)->icsk_bind_hash = tb;
-	sk_add_bind2_node(sk, &tb2->owners);
-	inet_csk(sk)->icsk_bind2_hash = tb2;
 }
 
 /*
@@ -157,7 +109,6 @@ static void __inet_put_port(struct sock *sk)
 	const int bhash = inet_bhashfn(sock_net(sk), inet_sk(sk)->inet_num,
 			hashinfo->bhash_size);
 	struct inet_bind_hashbucket *head = &hashinfo->bhash[bhash];
-	struct inet_bind2_bucket *tb2;
 	struct inet_bind_bucket *tb;
 
 	spin_lock(&head->lock);
@@ -166,13 +117,6 @@ static void __inet_put_port(struct sock *sk)
 	inet_csk(sk)->icsk_bind_hash = NULL;
 	inet_sk(sk)->inet_num = 0;
 	inet_bind_bucket_destroy(hashinfo->bind_bucket_cachep, tb);
-
-	if (inet_csk(sk)->icsk_bind2_hash) {
-		tb2 = inet_csk(sk)->icsk_bind2_hash;
-		__sk_del_bind2_node(sk);
-		inet_csk(sk)->icsk_bind2_hash = NULL;
-		inet_bind2_bucket_destroy(hashinfo->bind2_bucket_cachep, tb2);
-	}
 	spin_unlock(&head->lock);
 }
 
@@ -189,19 +133,14 @@ int __inet_inherit_port(const struct sock *sk, struct sock *child)
 	struct inet_hashinfo *table = sk->sk_prot->h.hashinfo;
 	unsigned short port = inet_sk(child)->inet_num;
 	const int bhash = inet_bhashfn(sock_net(sk), port,
-				       table->bhash_size);
+			table->bhash_size);
 	struct inet_bind_hashbucket *head = &table->bhash[bhash];
-	struct inet_bind2_hashbucket *head_bhash2;
-	bool created_inet_bind_bucket = false;
-	struct net *net = sock_net(sk);
-	struct inet_bind2_bucket *tb2;
 	struct inet_bind_bucket *tb;
 	int l3mdev;
 
 	spin_lock(&head->lock);
 	tb = inet_csk(sk)->icsk_bind_hash;
-	tb2 = inet_csk(sk)->icsk_bind2_hash;
-	if (unlikely(!tb || !tb2)) {
+	if (unlikely(!tb)) {
 		spin_unlock(&head->lock);
 		return -ENOENT;
 	}
@@ -214,45 +153,25 @@ int __inet_inherit_port(const struct sock *sk, struct sock *child)
 		 * as that of the child socket. We have to look up or
 		 * create a new bind bucket for the child here. */
 		inet_bind_bucket_for_each(tb, &head->chain) {
-			if (check_bind_bucket_match(tb, net, port, l3mdev))
+			if (net_eq(ib_net(tb), sock_net(sk)) &&
+			    tb->l3mdev == l3mdev && tb->port == port)
 				break;
 		}
 		if (!tb) {
 			tb = inet_bind_bucket_create(table->bind_bucket_cachep,
-						     net, head, port, l3mdev);
+						     sock_net(sk), head, port,
+						     l3mdev);
 			if (!tb) {
 				spin_unlock(&head->lock);
 				return -ENOMEM;
 			}
-			created_inet_bind_bucket = true;
 		}
 		inet_csk_update_fastreuse(tb, child);
-
-		goto bhash2_find;
-	} else if (!bind2_bucket_addr_match(tb2, child)) {
-		l3mdev = inet_sk_bound_l3mdev(sk);
-
-bhash2_find:
-		tb2 = inet_bind2_bucket_find(table, net, port, l3mdev, child,
-					     &head_bhash2);
-		if (!tb2) {
-			tb2 = inet_bind2_bucket_create(table->bind2_bucket_cachep,
-						       net, head_bhash2, port,
-						       l3mdev, child);
-			if (!tb2)
-				goto error;
-		}
 	}
-	inet_bind_hash(child, tb, tb2, port);
+	inet_bind_hash(child, tb, port);
 	spin_unlock(&head->lock);
 
 	return 0;
-
-error:
-	if (created_inet_bind_bucket)
-		inet_bind_bucket_destroy(table->bind_bucket_cachep, tb);
-	spin_unlock(&head->lock);
-	return -ENOMEM;
 }
 EXPORT_SYMBOL_GPL(__inet_inherit_port);
 
@@ -756,76 +675,6 @@ void inet_unhash(struct sock *sk)
 }
 EXPORT_SYMBOL_GPL(inet_unhash);
 
-static bool check_bind2_bucket_match(struct inet_bind2_bucket *tb,
-				     struct net *net, unsigned short port,
-				     int l3mdev, struct sock *sk)
-{
-#if IS_ENABLED(CONFIG_IPV6)
-	if (sk->sk_family == AF_INET6)
-		return net_eq(ib2_net(tb), net) && tb->port == port &&
-			tb->l3mdev == l3mdev &&
-			ipv6_addr_equal(&tb->v6_rcv_saddr, &sk->sk_v6_rcv_saddr);
-	else
-#endif
-		return net_eq(ib2_net(tb), net) && tb->port == port &&
-			tb->l3mdev == l3mdev && tb->rcv_saddr == sk->sk_rcv_saddr;
-}
-
-bool check_bind2_bucket_match_nulladdr(struct inet_bind2_bucket *tb,
-				       struct net *net, const unsigned short port,
-				       int l3mdev, const struct sock *sk)
-{
-#if IS_ENABLED(CONFIG_IPV6)
-	struct in6_addr nulladdr = {};
-
-	if (sk->sk_family == AF_INET6)
-		return net_eq(ib2_net(tb), net) && tb->port == port &&
-			tb->l3mdev == l3mdev &&
-			ipv6_addr_equal(&tb->v6_rcv_saddr, &nulladdr);
-	else
-#endif
-		return net_eq(ib2_net(tb), net) && tb->port == port &&
-			tb->l3mdev == l3mdev && tb->rcv_saddr == 0;
-}
-
-static struct inet_bind2_hashbucket *
-inet_bhashfn_portaddr(struct inet_hashinfo *hinfo, const struct sock *sk,
-		      const struct net *net, unsigned short port)
-{
-	u32 hash;
-
-#if IS_ENABLED(CONFIG_IPV6)
-	if (sk->sk_family == AF_INET6)
-		hash = ipv6_portaddr_hash(net, &sk->sk_v6_rcv_saddr, port);
-	else
-#endif
-		hash = ipv4_portaddr_hash(net, sk->sk_rcv_saddr, port);
-	return &hinfo->bhash2[hash & (hinfo->bhash_size - 1)];
-}
-
-/* This should only be called when the spinlock for the socket's corresponding
- * bind_hashbucket is held
- */
-struct inet_bind2_bucket *
-inet_bind2_bucket_find(struct inet_hashinfo *hinfo, struct net *net,
-		       const unsigned short port, int l3mdev, struct sock *sk,
-		       struct inet_bind2_hashbucket **head)
-{
-	struct inet_bind2_bucket *bhash2 = NULL;
-	struct inet_bind2_hashbucket *h;
-
-	h = inet_bhashfn_portaddr(hinfo, sk, net, port);
-	inet_bind_bucket_for_each(bhash2, &h->chain) {
-		if (check_bind2_bucket_match(bhash2, net, port, l3mdev, sk))
-			break;
-	}
-
-	if (head)
-		*head = h;
-
-	return bhash2;
-}
-
 /* RFC 6056 3.3.4.  Algorithm 4: Double-Hash Port Selection Algorithm
  * Note that we use 32bit integers (vs RFC 'short integers')
  * because 2^16 is not a multiple of num_ephemeral and this
@@ -846,13 +695,10 @@ int __inet_hash_connect(struct inet_timewait_death_row *death_row,
 {
 	struct inet_hashinfo *hinfo = death_row->hashinfo;
 	struct inet_timewait_sock *tw = NULL;
-	struct inet_bind2_hashbucket *head2;
 	struct inet_bind_hashbucket *head;
 	int port = inet_sk(sk)->inet_num;
 	struct net *net = sock_net(sk);
-	struct inet_bind2_bucket *tb2;
 	struct inet_bind_bucket *tb;
-	bool tb_created = false;
 	u32 remaining, offset;
 	int ret, i, low, high;
 	int l3mdev;
@@ -909,7 +755,8 @@ int __inet_hash_connect(struct inet_timewait_death_row *death_row,
 		 * the established check is already unique enough.
 		 */
 		inet_bind_bucket_for_each(tb, &head->chain) {
-			if (check_bind_bucket_match(tb, net, port, l3mdev)) {
+			if (net_eq(ib_net(tb), net) && tb->l3mdev == l3mdev &&
+			    tb->port == port) {
 				if (tb->fastreuse >= 0 ||
 				    tb->fastreuseport >= 0)
 					goto next_port;
@@ -927,7 +774,6 @@ int __inet_hash_connect(struct inet_timewait_death_row *death_row,
 			spin_unlock_bh(&head->lock);
 			return -ENOMEM;
 		}
-		tb_created = true;
 		tb->fastreuse = -1;
 		tb->fastreuseport = -1;
 		goto ok;
@@ -943,17 +789,6 @@ int __inet_hash_connect(struct inet_timewait_death_row *death_row,
 	return -EADDRNOTAVAIL;
 
 ok:
-	/* Find the corresponding tb2 bucket since we need to
-	 * add the socket to the bhash2 table as well
-	 */
-	tb2 = inet_bind2_bucket_find(hinfo, net, port, l3mdev, sk, &head2);
-	if (!tb2) {
-		tb2 = inet_bind2_bucket_create(hinfo->bind2_bucket_cachep, net,
-					       head2, port, l3mdev, sk);
-		if (!tb2)
-			goto error;
-	}
-
 	/* Here we want to add a little bit of randomness to the next source
 	 * port that will be chosen. We use a max() with a random here so that
 	 * on low contention the randomness is maximal and on high contention
@@ -963,7 +798,7 @@ int __inet_hash_connect(struct inet_timewait_death_row *death_row,
 	WRITE_ONCE(table_perturb[index], READ_ONCE(table_perturb[index]) + i + 2);
 
 	/* Head lock still held and bh's disabled */
-	inet_bind_hash(sk, tb, tb2, port);
+	inet_bind_hash(sk, tb, port);
 	if (sk_unhashed(sk)) {
 		inet_sk(sk)->inet_sport = htons(port);
 		inet_ehash_nolisten(sk, (struct sock *)tw, NULL);
@@ -975,12 +810,6 @@ int __inet_hash_connect(struct inet_timewait_death_row *death_row,
 		inet_twsk_deschedule_put(tw);
 	local_bh_enable();
 	return 0;
-
-error:
-	if (tb_created)
-		inet_bind_bucket_destroy(hinfo->bind_bucket_cachep, tb);
-	spin_unlock_bh(&head->lock);
-	return -ENOMEM;
 }
 
 /*

net/ipv4/tcp.c

@@ -4604,12 +4604,6 @@ void __init tcp_init(void)
 				  SLAB_HWCACHE_ALIGN | SLAB_PANIC |
 				  SLAB_ACCOUNT,
 				  NULL);
-	tcp_hashinfo.bind2_bucket_cachep =
-		kmem_cache_create("tcp_bind2_bucket",
-				  sizeof(struct inet_bind2_bucket), 0,
-				  SLAB_HWCACHE_ALIGN | SLAB_PANIC |
-				  SLAB_ACCOUNT,
-				  NULL);
 
 	/* Size and allocate the main established and bind bucket
 	 * hash tables.
@@ -4632,9 +4626,8 @@ void __init tcp_init(void)
 	if (inet_ehash_locks_alloc(&tcp_hashinfo))
 		panic("TCP: failed to alloc ehash_locks");
 	tcp_hashinfo.bhash =
-		alloc_large_system_hash("TCP bind bhash tables",
-					sizeof(struct inet_bind_hashbucket) +
-					sizeof(struct inet_bind2_hashbucket),
+		alloc_large_system_hash("TCP bind",
+					sizeof(struct inet_bind_hashbucket),
 					tcp_hashinfo.ehash_mask + 1,
 					17, /* one slot per 128 KB of memory */
 					0,
@@ -4643,12 +4636,9 @@ void __init tcp_init(void)
 					0,
 					64 * 1024);
 	tcp_hashinfo.bhash_size = 1U << tcp_hashinfo.bhash_size;
-	tcp_hashinfo.bhash2 =
-		(struct inet_bind2_hashbucket *)(tcp_hashinfo.bhash + tcp_hashinfo.bhash_size);
 	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);
-		INIT_HLIST_HEAD(&tcp_hashinfo.bhash2[i].chain);
 	}
 
 

tools/testing/selftests/net/.gitignore

@@ -37,4 +37,3 @@ gro
 ioam6_parser
 toeplitz
 cmsg_sender
-bind_bhash_test

tools/testing/selftests/net/Makefile

@@ -59,7 +59,6 @@ TEST_GEN_FILES += toeplitz
 TEST_GEN_FILES += cmsg_sender
 TEST_GEN_FILES += stress_reuseport_listen
 TEST_PROGS += test_vxlan_vnifiltering.sh
-TEST_GEN_FILES += bind_bhash_test
 
 TEST_FILES := settings
 
@@ -70,5 +69,4 @@ include bpf/Makefile
 
 $(OUTPUT)/reuseport_bpf_numa: LDLIBS += -lnuma
 $(OUTPUT)/tcp_mmap: LDLIBS += -lpthread
-$(OUTPUT)/bind_bhash_test: LDLIBS += -lpthread
 $(OUTPUT)/tcp_inq: LDLIBS += -lpthread

tools/testing/selftests/net/bind_bhash_test.c

-// SPDX-License-Identifier: GPL-2.0
-/*
- * This times how long it takes to bind to a port when the port already
- * has multiple sockets in its bhash table.
- *
- * In the setup(), we populate the port's bhash table with
- * MAX_THREADS * MAX_CONNECTIONS number of entries.
- */
-
-#include <unistd.h>
-#include <stdio.h>
-#include <netdb.h>
-#include <pthread.h>
-
-#define MAX_THREADS 600
-#define MAX_CONNECTIONS 40
-
-static const char *bind_addr = "::1";
-static const char *port;
-
-static int fd_array[MAX_THREADS][MAX_CONNECTIONS];
-
-static int bind_socket(int opt, const char *addr)
-{
-	struct addrinfo *res, hint = {};
-	int sock_fd, reuse = 1, err;
-
-	sock_fd = socket(AF_INET6, SOCK_STREAM, 0);
-	if (sock_fd < 0) {
-		perror("socket fd err");
-		return -1;
-	}
-
-	hint.ai_family = AF_INET6;
-	hint.ai_socktype = SOCK_STREAM;
-
-	err = getaddrinfo(addr, port, &hint, &res);
-	if (err) {
-		perror("getaddrinfo failed");
-		return -1;
-	}
-
-	if (opt) {
-		err = setsockopt(sock_fd, SOL_SOCKET, opt, &reuse, sizeof(reuse));
-		if (err) {
-			perror("setsockopt failed");
-			return -1;
-		}
-	}
-
-	err = bind(sock_fd, res->ai_addr, res->ai_addrlen);
-	if (err) {
-		perror("failed to bind to port");
-		return -1;
-	}
-
-	return sock_fd;
-}
-
-static void *setup(void *arg)
-{
-	int sock_fd, i;
-	int *array = (int *)arg;
-
-	for (i = 0; i < MAX_CONNECTIONS; i++) {
-		sock_fd = bind_socket(SO_REUSEADDR | SO_REUSEPORT, bind_addr);
-		if (sock_fd < 0)
-			return NULL;
-		array[i] = sock_fd;
-	}
-
-	return NULL;
-}
-
-int main(int argc, const char *argv[])
-{
-	int listener_fd, sock_fd, i, j;
-	pthread_t tid[MAX_THREADS];
-	clock_t begin, end;
-
-	if (argc != 2) {
-		printf("Usage: listener <port>\n");
-		return -1;
-	}
-
-	port = argv[1];
-
-	listener_fd = bind_socket(SO_REUSEADDR | SO_REUSEPORT, bind_addr);
-	if (listen(listener_fd, 100) < 0) {
-		perror("listen failed");
-		return -1;
-	}
-
-	/* Set up threads to populate the bhash table entry for the port */
-	for (i = 0; i < MAX_THREADS; i++)
-		pthread_create(&tid[i], NULL, setup, fd_array[i]);
-
-	for (i = 0; i < MAX_THREADS; i++)
-		pthread_join(tid[i], NULL);
-
-	begin = clock();
-
-	/* Bind to the same port on a different address */
-	sock_fd  = bind_socket(0, "2001:0db8:0:f101::1");
-
-	end = clock();
-
-	printf("time spent = %f\n", (double)(end - begin) / CLOCKS_PER_SEC);
-
-	/* clean up */
-	close(sock_fd);
-	close(listener_fd);
-	for (i = 0; i < MAX_THREADS; i++) {
-		for (j = 0; i < MAX_THREADS; i++)
-			close(fd_array[i][j]);
-	}
-
-	return 0;
-}