Commit dab78a17 authored by Philo Lu's avatar Philo Lu Committed by David S. Miller
Browse files

net/udp: Add 4-tuple hash list basis 



Add a new hash list, hash4, in udp table. It will be used to implement
4-tuple hash for connected udp sockets. This patch adds the hlist to
table, and implements helpers and the initialization. 4-tuple hash is
implemented in the following patch.

hash4 uses hlist_nulls to avoid moving wrongly onto another hlist due to
concurrent rehash, because rehash() can happen with lookup().

Co-developed-by: default avatarCambda Zhu <cambda@linux.alibaba.com>
Signed-off-by: default avatarCambda Zhu <cambda@linux.alibaba.com>
Co-developed-by: default avatarFred Chen <fred.cc@alibaba-inc.com>
Signed-off-by: default avatarFred Chen <fred.cc@alibaba-inc.com>
Co-developed-by: default avatarYubing Qiu <yubing.qiuyubing@alibaba-inc.com>
Signed-off-by: default avatarYubing Qiu <yubing.qiuyubing@alibaba-inc.com>
Signed-off-by: default avatarPhilo Lu <lulie@linux.alibaba.com>
Acked-by: default avatarWillem de Bruijn <willemb@google.com>
Acked-by: default avatarPaolo Abeni <pabeni@redhat.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent accdd51d

include/linux/udp.h

+11 −0
Original line number Diff line number Diff line
@@ -56,6 +56,12 @@ struct udp_sock { 
	int		 pending;	/* Any pending frames ? */

	__u8		 encap_type;	/* Is this an Encapsulation socket? */



#if !IS_ENABLED(CONFIG_BASE_SMALL)

	/* For UDP 4-tuple hash */

	__u16 udp_lrpa_hash;

	struct hlist_nulls_node udp_lrpa_node;

#endif



	/*

	 * Following member retains the information to create a UDP header

	 * when the socket is uncorked.
@@ -206,6 +212,11 @@ static inline void udp_allow_gso(struct sock *sk) 
#define udp_portaddr_for_each_entry_rcu(__sk, list) \

	hlist_for_each_entry_rcu(__sk, list, __sk_common.skc_portaddr_node)



#if !IS_ENABLED(CONFIG_BASE_SMALL)

#define udp_lrpa_for_each_entry_rcu(__up, node, list) \

	hlist_nulls_for_each_entry_rcu(__up, node, list, udp_lrpa_node)

#endif



#define IS_UDPLITE(__sk) (__sk->sk_protocol == IPPROTO_UDPLITE)



#endif	/* _LINUX_UDP_H */

include/net/udp.h

+82 −3
Original line number Diff line number Diff line
@@ -50,14 +50,21 @@ struct udp_skb_cb { 
#define UDP_SKB_CB(__skb)	((struct udp_skb_cb *)((__skb)->cb))



/**

 *	struct udp_hslot - UDP hash slot used by udp_table.hash

 *	struct udp_hslot - UDP hash slot used by udp_table.hash/hash4

 *

 *	@head:	head of list of sockets

 *	@nulls_head:	head of list of sockets, only used by hash4

 *	@count:	number of sockets in 'head' list

 *	@lock:	spinlock protecting changes to head/count

 */

struct udp_hslot {

	union {

		struct hlist_head	head;

		/* hash4 uses hlist_nulls to avoid moving wrongly onto another

		 * hlist, because rehash() can happen with lookup().

		 */

		struct hlist_nulls_head	nulls_head;

	};

	int			count;

	spinlock_t		lock;

} __aligned(2 * sizeof(long));
@@ -82,12 +89,17 @@ struct udp_hslot_main { 
 *

 *	@hash:	hash table, sockets are hashed on (local port)

 *	@hash2:	hash table, sockets are hashed on (local port, local address)

 *	@hash4:	hash table, connected sockets are hashed on

 *		(local port, local address, remote port, remote address)

 *	@mask:	number of slots in hash tables, minus 1

 *	@log:	log2(number of slots in hash table)

 */

struct udp_table {

	struct udp_hslot	*hash;

	struct udp_hslot_main	*hash2;

#if !IS_ENABLED(CONFIG_BASE_SMALL)

	struct udp_hslot	*hash4;

#endif

	unsigned int		mask;

	unsigned int		log;

};
@@ -114,13 +126,80 @@ static inline struct udp_hslot *udp_hashslot2(struct udp_table *table, 
static inline void udp_table_hash4_init(struct udp_table *table)

{

}



static inline struct udp_hslot *udp_hashslot4(struct udp_table *table,

					      unsigned int hash)

{

	BUILD_BUG();

	return NULL;

}



static inline bool udp_hashed4(const struct sock *sk)

{

	return false;

}



static inline unsigned int udp_hash4_slot_size(void)

{

	return 0;

}



static inline bool udp_has_hash4(const struct udp_hslot *hslot2)

{

	return false;

}



static inline void udp_hash4_inc(struct udp_hslot *hslot2)

{

}



static inline void udp_hash4_dec(struct udp_hslot *hslot2)

{

}

#else /* !CONFIG_BASE_SMALL */



/* Must be called with table->hash2 initialized */

static inline void udp_table_hash4_init(struct udp_table *table)

{

	for (int i = 0; i <= table->mask; i++)

	table->hash4 = (void *)(table->hash2 + (table->mask + 1));

	for (int i = 0; i <= table->mask; i++) {

		table->hash2[i].hash4_cnt = 0;



		INIT_HLIST_NULLS_HEAD(&table->hash4[i].nulls_head, i);

		table->hash4[i].count = 0;

		spin_lock_init(&table->hash4[i].lock);

	}

}



static inline struct udp_hslot *udp_hashslot4(struct udp_table *table,

					      unsigned int hash)

{

	return &table->hash4[hash & table->mask];

}



static inline bool udp_hashed4(const struct sock *sk)

{

	return !hlist_nulls_unhashed(&udp_sk(sk)->udp_lrpa_node);

}



static inline unsigned int udp_hash4_slot_size(void)

{

	return sizeof(struct udp_hslot);

}



static inline bool udp_has_hash4(const struct udp_hslot *hslot2)

{

	return UDP_HSLOT_MAIN(hslot2)->hash4_cnt;

}



static inline void udp_hash4_inc(struct udp_hslot *hslot2)

{

	UDP_HSLOT_MAIN(hslot2)->hash4_cnt++;

}



static inline void udp_hash4_dec(struct udp_hslot *hslot2)

{

	UDP_HSLOT_MAIN(hslot2)->hash4_cnt--;

}

#endif /* CONFIG_BASE_SMALL */

net/ipv4/udp.c

+4 −2
Original line number Diff line number Diff line
@@ -3427,7 +3427,8 @@ void __init udp_table_init(struct udp_table *table, const char *name) 
{

	unsigned int i, slot_size;



	slot_size = sizeof(struct udp_hslot) + sizeof(struct udp_hslot_main);

	slot_size = sizeof(struct udp_hslot) + sizeof(struct udp_hslot_main) +

		    udp_hash4_slot_size();

	table->hash = alloc_large_system_hash(name,

					      slot_size,

					      uhash_entries,
@@ -3482,7 +3483,8 @@ static struct udp_table __net_init *udp_pernet_table_alloc(unsigned int hash_ent 
	if (!udptable)

		goto out;



	slot_size = sizeof(struct udp_hslot) + sizeof(struct udp_hslot_main);

	slot_size = sizeof(struct udp_hslot) + sizeof(struct udp_hslot_main) +

		    udp_hash4_slot_size();

	udptable->hash = vmalloc_huge(hash_entries * slot_size,

				      GFP_KERNEL_ACCOUNT);

	if (!udptable->hash)