Commit ca065d0c authored by Eric Dumazet's avatar Eric Dumazet Committed by David S. Miller
Browse files

udp: no longer use SLAB_DESTROY_BY_RCU 



Tom Herbert would like not touching UDP socket refcnt for encapsulated
traffic. For this to happen, we need to use normal RCU rules, with a grace
period before freeing a socket. UDP sockets are not short lived in the
high usage case, so the added cost of call_rcu() should not be a concern.

This actually removes a lot of complexity in UDP stack.

Multicast receives no longer need to hold a bucket spinlock.

Note that ip early demux still needs to take a reference on the socket.

Same remark for functions used by xt_socket and xt_PROXY netfilter modules,
but this might be changed later.

Performance for a single UDP socket receiving flood traffic from
many RX queues/cpus.

Simple udp_rx using simple recvfrom() loop :
438 kpps instead of 374 kpps : 17 % increase of the peak rate.

v2: Addressed Willem de Bruijn feedback in multicast handling
 - keep early demux break in __udp4_lib_demux_lookup()

Signed-off-by: default avatarEric Dumazet <edumazet@google.com>
Cc: Tom Herbert <tom@herbertland.com>
Cc: Willem de Bruijn <willemb@google.com>
Tested-by: default avatarTom Herbert <tom@herbertland.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent a4298e45

include/linux/udp.h

+4 −4
Original line number Diff line number Diff line
@@ -98,11 +98,11 @@ static inline bool udp_get_no_check6_rx(struct sock *sk) 
	return udp_sk(sk)->no_check6_rx;

}



#define udp_portaddr_for_each_entry(__sk, node, list) \

	hlist_nulls_for_each_entry(__sk, node, list, __sk_common.skc_portaddr_node)

#define udp_portaddr_for_each_entry(__sk, list) \

	hlist_for_each_entry(__sk, list, __sk_common.skc_portaddr_node)



#define udp_portaddr_for_each_entry_rcu(__sk, node, list) \

	hlist_nulls_for_each_entry_rcu(__sk, node, list, __sk_common.skc_portaddr_node)

#define udp_portaddr_for_each_entry_rcu(__sk, list) \

	hlist_for_each_entry_rcu(__sk, list, __sk_common.skc_portaddr_node)



#define IS_UDPLITE(__sk) (udp_sk(__sk)->pcflag)

include/net/sock.h

+6 −6
Original line number Diff line number Diff line
@@ -178,7 +178,7 @@ struct sock_common { 
	int			skc_bound_dev_if;

	union {

		struct hlist_node	skc_bind_node;

		struct hlist_nulls_node skc_portaddr_node;

		struct hlist_node	skc_portaddr_node;

	};

	struct proto		*skc_prot;

	possible_net_t		skc_net;
@@ -670,18 +670,18 @@ static inline void sk_add_bind_node(struct sock *sk, 
	hlist_for_each_entry(__sk, list, sk_bind_node)



/**

 * sk_nulls_for_each_entry_offset - iterate over a list at a given struct offset

 * sk_for_each_entry_offset_rcu - iterate over a list at a given struct offset

 * @tpos:	the type * to use as a loop cursor.

 * @pos:	the &struct hlist_node to use as a loop cursor.

 * @head:	the head for your list.

 * @offset:	offset of hlist_node within the struct.

 *

 */

#define sk_nulls_for_each_entry_offset(tpos, pos, head, offset)		       \

	for (pos = (head)->first;					       \

	     (!is_a_nulls(pos)) &&					       \

#define sk_for_each_entry_offset_rcu(tpos, pos, head, offset)		       \

	for (pos = rcu_dereference((head)->first);			       \

	     pos != NULL &&						       \

		({ tpos = (typeof(*tpos) *)((void *)pos - offset); 1;});       \

	     pos = pos->next)

	     pos = rcu_dereference(pos->next))



static inline struct user_namespace *sk_user_ns(struct sock *sk)

{

include/net/udp.h

+1 −1
Original line number Diff line number Diff line
@@ -59,7 +59,7 @@ struct udp_skb_cb { 
 *	@lock:	spinlock protecting changes to head/count

 */

struct udp_hslot {

	struct hlist_nulls_head	head;

	struct hlist_head	head;

	int			count;

	spinlock_t		lock;

} __attribute__((aligned(2 * sizeof(long))));

net/ipv4/udp.c

+87 −206
Original line number Diff line number Diff line
@@ -143,10 +143,9 @@ static int udp_lib_lport_inuse(struct net *net, __u16 num, 
			       unsigned int log)

{

	struct sock *sk2;

	struct hlist_nulls_node *node;

	kuid_t uid = sock_i_uid(sk);



	sk_nulls_for_each(sk2, node, &hslot->head) {

	sk_for_each(sk2, &hslot->head) {

		if (net_eq(sock_net(sk2), net) &&

		    sk2 != sk &&

		    (bitmap || udp_sk(sk2)->udp_port_hash == num) &&
@@ -177,12 +176,11 @@ static int udp_lib_lport_inuse2(struct net *net, __u16 num, 
						  bool match_wildcard))

{

	struct sock *sk2;

	struct hlist_nulls_node *node;

	kuid_t uid = sock_i_uid(sk);

	int res = 0;



	spin_lock(&hslot2->lock);

	udp_portaddr_for_each_entry(sk2, node, &hslot2->head) {

	udp_portaddr_for_each_entry(sk2, &hslot2->head) {

		if (net_eq(sock_net(sk2), net) &&

		    sk2 != sk &&

		    (udp_sk(sk2)->udp_port_hash == num) &&
@@ -207,11 +205,10 @@ static int udp_reuseport_add_sock(struct sock *sk, struct udp_hslot *hslot, 
						    bool match_wildcard))

{

	struct net *net = sock_net(sk);

	struct hlist_nulls_node *node;

	kuid_t uid = sock_i_uid(sk);

	struct sock *sk2;



	sk_nulls_for_each(sk2, node, &hslot->head) {

	sk_for_each(sk2, &hslot->head) {

		if (net_eq(sock_net(sk2), net) &&

		    sk2 != sk &&

		    sk2->sk_family == sk->sk_family &&
@@ -333,17 +330,18 @@ found: 
			goto fail_unlock;

		}



		sk_nulls_add_node_rcu(sk, &hslot->head);

		sk_add_node_rcu(sk, &hslot->head);

		hslot->count++;

		sock_prot_inuse_add(sock_net(sk), sk->sk_prot, 1);



		hslot2 = udp_hashslot2(udptable, udp_sk(sk)->udp_portaddr_hash);

		spin_lock(&hslot2->lock);

		hlist_nulls_add_head_rcu(&udp_sk(sk)->udp_portaddr_node,

		hlist_add_head_rcu(&udp_sk(sk)->udp_portaddr_node,

					 &hslot2->head);

		hslot2->count++;

		spin_unlock(&hslot2->lock);

	}

	sock_set_flag(sk, SOCK_RCU_FREE);

	error = 0;

fail_unlock:

	spin_unlock_bh(&hslot->lock);
@@ -497,37 +495,27 @@ static struct sock *udp4_lib_lookup2(struct net *net, 
		struct sk_buff *skb)

{

	struct sock *sk, *result;

	struct hlist_nulls_node *node;

	int score, badness, matches = 0, reuseport = 0;

	bool select_ok = true;

	u32 hash = 0;



begin:

	result = NULL;

	badness = 0;

	udp_portaddr_for_each_entry_rcu(sk, node, &hslot2->head) {

	udp_portaddr_for_each_entry_rcu(sk, &hslot2->head) {

		score = compute_score2(sk, net, saddr, sport,

				      daddr, hnum, dif);

		if (score > badness) {

			result = sk;

			badness = score;

			reuseport = sk->sk_reuseport;

			if (reuseport) {

				hash = udp_ehashfn(net, daddr, hnum,

						   saddr, sport);

				if (select_ok) {

					struct sock *sk2;



					sk2 = reuseport_select_sock(sk, hash, skb,

				result = reuseport_select_sock(sk, hash, skb,

							sizeof(struct udphdr));

					if (sk2) {

						result = sk2;

						select_ok = false;

						goto found;

					}

				}

				if (result)

					return result;

				matches = 1;

			}

			badness = score;

			result = sk;

		} else if (score == badness && reuseport) {

			matches++;

			if (reciprocal_scale(hash, matches) == 0)
@@ -535,23 +523,6 @@ begin: 
			hash = next_pseudo_random32(hash);

		}

	}

	/*

	 * if the nulls value we got at the end of this lookup is

	 * not the expected one, we must restart lookup.

	 * We probably met an item that was moved to another chain.

	 */

	if (get_nulls_value(node) != slot2)

		goto begin;

	if (result) {

found:

		if (unlikely(!atomic_inc_not_zero_hint(&result->sk_refcnt, 2)))

			result = NULL;

		else if (unlikely(compute_score2(result, net, saddr, sport,

				  daddr, hnum, dif) < badness)) {

			sock_put(result);

			goto begin;

		}

	}

	return result;

}
@@ -563,15 +534,12 @@ struct sock *__udp4_lib_lookup(struct net *net, __be32 saddr, 
		int dif, struct udp_table *udptable, struct sk_buff *skb)

{

	struct sock *sk, *result;

	struct hlist_nulls_node *node;

	unsigned short hnum = ntohs(dport);

	unsigned int hash2, slot2, slot = udp_hashfn(net, hnum, udptable->mask);

	struct udp_hslot *hslot2, *hslot = &udptable->hash[slot];

	int score, badness, matches = 0, reuseport = 0;

	bool select_ok = true;

	u32 hash = 0;



	rcu_read_lock();

	if (hslot->count > 10) {

		hash2 = udp4_portaddr_hash(net, daddr, hnum);

		slot2 = hash2 & udptable->mask;
@@ -593,35 +561,27 @@ struct sock *__udp4_lib_lookup(struct net *net, __be32 saddr, 
						  htonl(INADDR_ANY), hnum, dif,

						  hslot2, slot2, skb);

		}

		rcu_read_unlock();

		return result;

	}

begin:

	result = NULL;

	badness = 0;

	sk_nulls_for_each_rcu(sk, node, &hslot->head) {

	sk_for_each_rcu(sk, &hslot->head) {

		score = compute_score(sk, net, saddr, hnum, sport,

				      daddr, dport, dif);

		if (score > badness) {

			result = sk;

			badness = score;

			reuseport = sk->sk_reuseport;

			if (reuseport) {

				hash = udp_ehashfn(net, daddr, hnum,

						   saddr, sport);

				if (select_ok) {

					struct sock *sk2;



					sk2 = reuseport_select_sock(sk, hash, skb,

				result = reuseport_select_sock(sk, hash, skb,

							sizeof(struct udphdr));

					if (sk2) {

						result = sk2;

						select_ok = false;

						goto found;

					}

				}

				if (result)

					return result;

				matches = 1;

			}

			result = sk;

			badness = score;

		} else if (score == badness && reuseport) {

			matches++;

			if (reciprocal_scale(hash, matches) == 0)
@@ -629,25 +589,6 @@ begin: 
			hash = next_pseudo_random32(hash);

		}

	}

	/*

	 * if the nulls value we got at the end of this lookup is

	 * not the expected one, we must restart lookup.

	 * We probably met an item that was moved to another chain.

	 */

	if (get_nulls_value(node) != slot)

		goto begin;



	if (result) {

found:

		if (unlikely(!atomic_inc_not_zero_hint(&result->sk_refcnt, 2)))

			result = NULL;

		else if (unlikely(compute_score(result, net, saddr, hnum, sport,

				  daddr, dport, dif) < badness)) {

			sock_put(result);

			goto begin;

		}

	}

	rcu_read_unlock();

	return result;

}

EXPORT_SYMBOL_GPL(__udp4_lib_lookup);
@@ -663,13 +604,24 @@ static inline struct sock *__udp4_lib_lookup_skb(struct sk_buff *skb, 
				 udptable, skb);

}



/* Must be called under rcu_read_lock().

 * Does increment socket refcount.

 */

#if IS_ENABLED(CONFIG_NETFILTER_XT_MATCH_SOCKET) || \

    IS_ENABLED(CONFIG_NETFILTER_XT_TARGET_TPROXY)

struct sock *udp4_lib_lookup(struct net *net, __be32 saddr, __be16 sport,

			     __be32 daddr, __be16 dport, int dif)

{

	return __udp4_lib_lookup(net, saddr, sport, daddr, dport, dif,

				 &udp_table, NULL);

	struct sock *sk;



	sk = __udp4_lib_lookup(net, saddr, sport, daddr, dport,

			       dif, &udp_table, NULL);

	if (sk && !atomic_inc_not_zero(&sk->sk_refcnt))

		sk = NULL;

	return sk;

}

EXPORT_SYMBOL_GPL(udp4_lib_lookup);

#endif



static inline bool __udp_is_mcast_sock(struct net *net, struct sock *sk,

				       __be16 loc_port, __be32 loc_addr,
@@ -771,7 +723,7 @@ void __udp4_lib_err(struct sk_buff *skb, u32 info, struct udp_table *udptable) 
	sk->sk_err = err;

	sk->sk_error_report(sk);

out:

	sock_put(sk);

	return;

}



void udp_err(struct sk_buff *skb, u32 info)
@@ -1474,13 +1426,13 @@ void udp_lib_unhash(struct sock *sk) 
		spin_lock_bh(&hslot->lock);

		if (rcu_access_pointer(sk->sk_reuseport_cb))

			reuseport_detach_sock(sk);

		if (sk_nulls_del_node_init_rcu(sk)) {

		if (sk_del_node_init_rcu(sk)) {

			hslot->count--;

			inet_sk(sk)->inet_num = 0;

			sock_prot_inuse_add(sock_net(sk), sk->sk_prot, -1);



			spin_lock(&hslot2->lock);

			hlist_nulls_del_init_rcu(&udp_sk(sk)->udp_portaddr_node);

			hlist_del_init_rcu(&udp_sk(sk)->udp_portaddr_node);

			hslot2->count--;

			spin_unlock(&hslot2->lock);

		}
@@ -1513,12 +1465,12 @@ void udp_lib_rehash(struct sock *sk, u16 newhash) 


			if (hslot2 != nhslot2) {

				spin_lock(&hslot2->lock);

				hlist_nulls_del_init_rcu(&udp_sk(sk)->udp_portaddr_node);

				hlist_del_init_rcu(&udp_sk(sk)->udp_portaddr_node);

				hslot2->count--;

				spin_unlock(&hslot2->lock);



				spin_lock(&nhslot2->lock);

				hlist_nulls_add_head_rcu(&udp_sk(sk)->udp_portaddr_node,

				hlist_add_head_rcu(&udp_sk(sk)->udp_portaddr_node,

							 &nhslot2->head);

				nhslot2->count++;

				spin_unlock(&nhslot2->lock);
@@ -1697,35 +1649,6 @@ drop: 
	return -1;

}



static void flush_stack(struct sock **stack, unsigned int count,

			struct sk_buff *skb, unsigned int final)

{

	unsigned int i;

	struct sk_buff *skb1 = NULL;

	struct sock *sk;



	for (i = 0; i < count; i++) {

		sk = stack[i];

		if (likely(!skb1))

			skb1 = (i == final) ? skb : skb_clone(skb, GFP_ATOMIC);



		if (!skb1) {

			atomic_inc(&sk->sk_drops);

			UDP_INC_STATS_BH(sock_net(sk), UDP_MIB_RCVBUFERRORS,

					 IS_UDPLITE(sk));

			UDP_INC_STATS_BH(sock_net(sk), UDP_MIB_INERRORS,

					 IS_UDPLITE(sk));

		}



		if (skb1 && udp_queue_rcv_skb(sk, skb1) <= 0)

			skb1 = NULL;



		sock_put(sk);

	}

	if (unlikely(skb1))

		kfree_skb(skb1);

}



/* For TCP sockets, sk_rx_dst is protected by socket lock

 * For UDP, we use xchg() to guard against concurrent changes.

 */
@@ -1749,14 +1672,14 @@ static int __udp4_lib_mcast_deliver(struct net *net, struct sk_buff *skb, 
				    struct udp_table *udptable,

				    int proto)

{

	struct sock *sk, *stack[256 / sizeof(struct sock *)];

	struct hlist_nulls_node *node;

	struct sock *sk, *first = NULL;

	unsigned short hnum = ntohs(uh->dest);

	struct udp_hslot *hslot = udp_hashslot(udptable, net, hnum);

	int dif = skb->dev->ifindex;

	unsigned int count = 0, offset = offsetof(typeof(*sk), sk_nulls_node);

	unsigned int hash2 = 0, hash2_any = 0, use_hash2 = (hslot->count > 10);

	bool inner_flushed = false;

	unsigned int offset = offsetof(typeof(*sk), sk_node);

	int dif = skb->dev->ifindex;

	struct hlist_node *node;

	struct sk_buff *nskb;



	if (use_hash2) {

		hash2_any = udp4_portaddr_hash(net, htonl(INADDR_ANY), hnum) &
@@ -1767,40 +1690,42 @@ start_lookup: 
		offset = offsetof(typeof(*sk), __sk_common.skc_portaddr_node);

	}



	spin_lock(&hslot->lock);

	sk_nulls_for_each_entry_offset(sk, node, &hslot->head, offset) {

		if (__udp_is_mcast_sock(net, sk,

					uh->dest, daddr,

					uh->source, saddr,

					dif, hnum)) {

			if (unlikely(count == ARRAY_SIZE(stack))) {

				flush_stack(stack, count, skb, ~0);

				inner_flushed = true;

				count = 0;

	sk_for_each_entry_offset_rcu(sk, node, &hslot->head, offset) {

		if (!__udp_is_mcast_sock(net, sk, uh->dest, daddr,

					 uh->source, saddr, dif, hnum))

			continue;



		if (!first) {

			first = sk;

			continue;

		}

			stack[count++] = sk;

			sock_hold(sk);

		nskb = skb_clone(skb, GFP_ATOMIC);



		if (unlikely(!nskb)) {

			atomic_inc(&sk->sk_drops);

			UDP_INC_STATS_BH(net, UDP_MIB_RCVBUFERRORS,

					 IS_UDPLITE(sk));

			UDP_INC_STATS_BH(net, UDP_MIB_INERRORS,

					 IS_UDPLITE(sk));

			continue;

		}

		if (udp_queue_rcv_skb(sk, nskb) > 0)

			consume_skb(nskb);

	}



	spin_unlock(&hslot->lock);



	/* Also lookup *:port if we are using hash2 and haven't done so yet. */

	if (use_hash2 && hash2 != hash2_any) {

		hash2 = hash2_any;

		goto start_lookup;

	}



	/*

	 * do the slow work with no lock held

	 */

	if (count) {

		flush_stack(stack, count, skb, count - 1);

	if (first) {

		if (udp_queue_rcv_skb(first, skb) > 0)

			consume_skb(skb);

	} else {

		if (!inner_flushed)

		kfree_skb(skb);

		UDP_INC_STATS_BH(net, UDP_MIB_IGNOREDMULTI,

				 proto == IPPROTO_UDPLITE);

		consume_skb(skb);

	}

	return 0;

}
@@ -1897,7 +1822,6 @@ int __udp4_lib_rcv(struct sk_buff *skb, struct udp_table *udptable, 
						 inet_compute_pseudo);



		ret = udp_queue_rcv_skb(sk, skb);

		sock_put(sk);



		/* a return value > 0 means to resubmit the input, but

		 * it wants the return to be -protocol, or 0
@@ -1958,49 +1882,24 @@ static struct sock *__udp4_lib_mcast_demux_lookup(struct net *net, 
						  int dif)

{

	struct sock *sk, *result;

	struct hlist_nulls_node *node;

	unsigned short hnum = ntohs(loc_port);

	unsigned int count, slot = udp_hashfn(net, hnum, udp_table.mask);

	unsigned int slot = udp_hashfn(net, hnum, udp_table.mask);

	struct udp_hslot *hslot = &udp_table.hash[slot];



	/* Do not bother scanning a too big list */

	if (hslot->count > 10)

		return NULL;



	rcu_read_lock();

begin:

	count = 0;

	result = NULL;

	sk_nulls_for_each_rcu(sk, node, &hslot->head) {

		if (__udp_is_mcast_sock(net, sk,

					loc_port, loc_addr,

					rmt_port, rmt_addr,

					dif, hnum)) {

	sk_for_each_rcu(sk, &hslot->head) {

		if (__udp_is_mcast_sock(net, sk, loc_port, loc_addr,

					rmt_port, rmt_addr, dif, hnum)) {

			if (result)

				return NULL;

			result = sk;

			++count;

		}

	}

	/*

	 * if the nulls value we got at the end of this lookup is

	 * not the expected one, we must restart lookup.

	 * We probably met an item that was moved to another chain.

	 */

	if (get_nulls_value(node) != slot)

		goto begin;



	if (result) {

		if (count != 1 ||

		    unlikely(!atomic_inc_not_zero_hint(&result->sk_refcnt, 2)))

			result = NULL;

		else if (unlikely(!__udp_is_mcast_sock(net, result,

						       loc_port, loc_addr,

						       rmt_port, rmt_addr,

						       dif, hnum))) {

			sock_put(result);

			result = NULL;

		}

	}

	rcu_read_unlock();

	return result;

}
@@ -2013,37 +1912,22 @@ static struct sock *__udp4_lib_demux_lookup(struct net *net, 
					    __be16 rmt_port, __be32 rmt_addr,

					    int dif)

{

	struct sock *sk, *result;

	struct hlist_nulls_node *node;

	unsigned short hnum = ntohs(loc_port);

	unsigned int hash2 = udp4_portaddr_hash(net, loc_addr, hnum);

	unsigned int slot2 = hash2 & udp_table.mask;

	struct udp_hslot *hslot2 = &udp_table.hash2[slot2];

	INET_ADDR_COOKIE(acookie, rmt_addr, loc_addr);

	const __portpair ports = INET_COMBINED_PORTS(rmt_port, hnum);

	struct sock *sk;



	rcu_read_lock();

	result = NULL;

	udp_portaddr_for_each_entry_rcu(sk, node, &hslot2->head) {

		if (INET_MATCH(sk, net, acookie,

			       rmt_addr, loc_addr, ports, dif))

			result = sk;

	udp_portaddr_for_each_entry_rcu(sk, &hslot2->head) {

		if (INET_MATCH(sk, net, acookie, rmt_addr,

			       loc_addr, ports, dif))

			return sk;

		/* Only check first socket in chain */

		break;

	}



	if (result) {

		if (unlikely(!atomic_inc_not_zero_hint(&result->sk_refcnt, 2)))

			result = NULL;

		else if (unlikely(!INET_MATCH(sk, net, acookie,

					      rmt_addr, loc_addr,

					      ports, dif))) {

			sock_put(result);

			result = NULL;

		}

	}

	rcu_read_unlock();

	return result;

	return NULL;

}



void udp_v4_early_demux(struct sk_buff *skb)
@@ -2051,7 +1935,7 @@ void udp_v4_early_demux(struct sk_buff *skb) 
	struct net *net = dev_net(skb->dev);

	const struct iphdr *iph;

	const struct udphdr *uh;

	struct sock *sk;

	struct sock *sk = NULL;

	struct dst_entry *dst;

	int dif = skb->dev->ifindex;

	int ours;
@@ -2083,11 +1967,9 @@ void udp_v4_early_demux(struct sk_buff *skb) 
	} else if (skb->pkt_type == PACKET_HOST) {

		sk = __udp4_lib_demux_lookup(net, uh->dest, iph->daddr,

					     uh->source, iph->saddr, dif);

	} else {

		return;

	}



	if (!sk)

	if (!sk || !atomic_inc_not_zero_hint(&sk->sk_refcnt, 2))

		return;



	skb->sk = sk;
@@ -2387,14 +2269,13 @@ static struct sock *udp_get_first(struct seq_file *seq, int start) 


	for (state->bucket = start; state->bucket <= state->udp_table->mask;

	     ++state->bucket) {

		struct hlist_nulls_node *node;

		struct udp_hslot *hslot = &state->udp_table->hash[state->bucket];



		if (hlist_nulls_empty(&hslot->head))

		if (hlist_empty(&hslot->head))

			continue;



		spin_lock_bh(&hslot->lock);

		sk_nulls_for_each(sk, node, &hslot->head) {

		sk_for_each(sk, &hslot->head) {

			if (!net_eq(sock_net(sk), net))

				continue;

			if (sk->sk_family == state->family)
@@ -2413,7 +2294,7 @@ static struct sock *udp_get_next(struct seq_file *seq, struct sock *sk) 
	struct net *net = seq_file_net(seq);



	do {

		sk = sk_nulls_next(sk);

		sk = sk_next(sk);

	} while (sk && (!net_eq(sock_net(sk), net) || sk->sk_family != state->family));



	if (!sk) {
@@ -2622,12 +2503,12 @@ void __init udp_table_init(struct udp_table *table, const char *name) 


	table->hash2 = table->hash + (table->mask + 1);

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

		INIT_HLIST_NULLS_HEAD(&table->hash[i].head, i);

		INIT_HLIST_HEAD(&table->hash[i].head);

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

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

	}

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

		INIT_HLIST_NULLS_HEAD(&table->hash2[i].head, i);

		INIT_HLIST_HEAD(&table->hash2[i].head);

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

		spin_lock_init(&table->hash2[i].lock);

	}

net/ipv4/udp_diag.c

+9 −9
Original line number Diff line number Diff line
@@ -36,10 +36,11 @@ static int udp_dump_one(struct udp_table *tbl, struct sk_buff *in_skb, 
			const struct inet_diag_req_v2 *req)

{

	int err = -EINVAL;

	struct sock *sk;

	struct sock *sk = NULL;

	struct sk_buff *rep;

	struct net *net = sock_net(in_skb->sk);



	rcu_read_lock();

	if (req->sdiag_family == AF_INET)

		sk = __udp4_lib_lookup(net,

				req->id.idiag_src[0], req->id.idiag_sport,
@@ -54,9 +55,9 @@ static int udp_dump_one(struct udp_table *tbl, struct sk_buff *in_skb, 
				req->id.idiag_dport,

				req->id.idiag_if, tbl, NULL);

#endif

	else

		goto out_nosk;



	if (sk && !atomic_inc_not_zero(&sk->sk_refcnt))

		sk = NULL;

	rcu_read_unlock();

	err = -ENOENT;

	if (!sk)

		goto out_nosk;
@@ -96,24 +97,23 @@ static void udp_dump(struct udp_table *table, struct sk_buff *skb, 
		     struct netlink_callback *cb,

		     const struct inet_diag_req_v2 *r, struct nlattr *bc)

{

	int num, s_num, slot, s_slot;

	struct net *net = sock_net(skb->sk);

	int num, s_num, slot, s_slot;



	s_slot = cb->args[0];

	num = s_num = cb->args[1];



	for (slot = s_slot; slot <= table->mask; s_num = 0, slot++) {

		struct sock *sk;

		struct hlist_nulls_node *node;

		struct udp_hslot *hslot = &table->hash[slot];

		struct sock *sk;



		num = 0;



		if (hlist_nulls_empty(&hslot->head))

		if (hlist_empty(&hslot->head))

			continue;



		spin_lock_bh(&hslot->lock);

		sk_nulls_for_each(sk, node, &hslot->head) {

		sk_for_each(sk, &hslot->head) {

			struct inet_sock *inet = inet_sk(sk);



			if (!net_eq(sock_net(sk), net))

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