Commit 4cad4efa authored by David S. Miller's avatar David S. Miller
Browse files

Merge branch 'net-neigh-rcu' 



Eric Dumazet says:

====================
neighbour: convert neigh_dump_info() to RCU

Remove RTNL requirement for "ip neighbour show" command.
====================

Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parents 9fc31a92 ba0f7806

net/core/neighbour.c

+36 −32
Original line number Diff line number Diff line
@@ -1771,7 +1771,7 @@ static void neigh_parms_destroy(struct neigh_parms *parms) 


static struct lock_class_key neigh_table_proxy_queue_class;



static struct neigh_table *neigh_tables[NEIGH_NR_TABLES] __read_mostly;

static struct neigh_table __rcu *neigh_tables[NEIGH_NR_TABLES] __read_mostly;



void neigh_table_init(int index, struct neigh_table *tbl)

{
@@ -1828,13 +1828,19 @@ void neigh_table_init(int index, struct neigh_table *tbl) 
	tbl->last_flush = now;

	tbl->last_rand	= now + tbl->parms.reachable_time * 20;



	neigh_tables[index] = tbl;

	rcu_assign_pointer(neigh_tables[index], tbl);

}

EXPORT_SYMBOL(neigh_table_init);



/*

 * Only called from ndisc_cleanup(), which means this is dead code

 * because we no longer can unload IPv6 module.

 */

int neigh_table_clear(int index, struct neigh_table *tbl)

{

	neigh_tables[index] = NULL;

	RCU_INIT_POINTER(neigh_tables[index], NULL);

	synchronize_rcu();



	/* It is not clean... Fix it to unload IPv6 module safely */

	cancel_delayed_work_sync(&tbl->managed_work);

	cancel_delayed_work_sync(&tbl->gc_work);
@@ -1866,10 +1872,10 @@ static struct neigh_table *neigh_find_table(int family) 


	switch (family) {

	case AF_INET:

		tbl = neigh_tables[NEIGH_ARP_TABLE];

		tbl = rcu_dereference_rtnl(neigh_tables[NEIGH_ARP_TABLE]);

		break;

	case AF_INET6:

		tbl = neigh_tables[NEIGH_ND_TABLE];

		tbl = rcu_dereference_rtnl(neigh_tables[NEIGH_ND_TABLE]);

		break;

	}
@@ -2333,7 +2339,7 @@ static int neightbl_set(struct sk_buff *skb, struct nlmsghdr *nlh, 
	ndtmsg = nlmsg_data(nlh);



	for (tidx = 0; tidx < NEIGH_NR_TABLES; tidx++) {

		tbl = neigh_tables[tidx];

		tbl = rcu_dereference_rtnl(neigh_tables[tidx]);

		if (!tbl)

			continue;

		if (ndtmsg->ndtm_family && tbl->family != ndtmsg->ndtm_family)
@@ -2521,7 +2527,7 @@ static int neightbl_dump_info(struct sk_buff *skb, struct netlink_callback *cb) 
	for (tidx = 0; tidx < NEIGH_NR_TABLES; tidx++) {

		struct neigh_parms *p;



		tbl = neigh_tables[tidx];

		tbl = rcu_dereference_rtnl(neigh_tables[tidx]);

		if (!tbl)

			continue;
@@ -2709,7 +2715,7 @@ static int neigh_dump_table(struct neigh_table *tbl, struct sk_buff *skb, 
{

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

	struct neighbour *n;

	int rc, h, s_h = cb->args[1];

	int err = 0, h, s_h = cb->args[1];

	int idx, s_idx = idx = cb->args[2];

	struct neigh_hash_table *nht;

	unsigned int flags = NLM_F_MULTI;
@@ -2717,7 +2723,6 @@ static int neigh_dump_table(struct neigh_table *tbl, struct sk_buff *skb, 
	if (filter->dev_idx || filter->master_idx)

		flags |= NLM_F_DUMP_FILTERED;



	rcu_read_lock();

	nht = rcu_dereference(tbl->nht);



	for (h = s_h; h < (1 << nht->hash_shift); h++) {
@@ -2731,23 +2736,19 @@ static int neigh_dump_table(struct neigh_table *tbl, struct sk_buff *skb, 
			if (neigh_ifindex_filtered(n->dev, filter->dev_idx) ||

			    neigh_master_filtered(n->dev, filter->master_idx))

				goto next;

			if (neigh_fill_info(skb, n, NETLINK_CB(cb->skb).portid,

			err = neigh_fill_info(skb, n, NETLINK_CB(cb->skb).portid,

					      cb->nlh->nlmsg_seq,

					    RTM_NEWNEIGH,

					    flags) < 0) {

				rc = -1;

					      RTM_NEWNEIGH, flags);

			if (err < 0)

				goto out;

			}

next:

			idx++;

		}

	}

	rc = skb->len;

out:

	rcu_read_unlock();

	cb->args[1] = h;

	cb->args[2] = idx;

	return rc;

	return err;

}



static int pneigh_dump_table(struct neigh_table *tbl, struct sk_buff *skb,
@@ -2756,7 +2757,7 @@ static int pneigh_dump_table(struct neigh_table *tbl, struct sk_buff *skb, 
{

	struct pneigh_entry *n;

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

	int rc, h, s_h = cb->args[3];

	int err = 0, h, s_h = cb->args[3];

	int idx, s_idx = idx = cb->args[4];

	unsigned int flags = NLM_F_MULTI;
@@ -2774,11 +2775,11 @@ static int pneigh_dump_table(struct neigh_table *tbl, struct sk_buff *skb, 
			if (neigh_ifindex_filtered(n->dev, filter->dev_idx) ||

			    neigh_master_filtered(n->dev, filter->master_idx))

				goto next;

			if (pneigh_fill_info(skb, n, NETLINK_CB(cb->skb).portid,

			err = pneigh_fill_info(skb, n, NETLINK_CB(cb->skb).portid,

					       cb->nlh->nlmsg_seq,

					    RTM_NEWNEIGH, flags, tbl) < 0) {

					       RTM_NEWNEIGH, flags, tbl);

			if (err < 0) {

				read_unlock_bh(&tbl->lock);

				rc = -1;

				goto out;

			}

		next:
@@ -2787,12 +2788,10 @@ static int pneigh_dump_table(struct neigh_table *tbl, struct sk_buff *skb, 
	}



	read_unlock_bh(&tbl->lock);

	rc = skb->len;

out:

	cb->args[3] = h;

	cb->args[4] = idx;

	return rc;



	return err;

}



static int neigh_valid_dump_req(const struct nlmsghdr *nlh,
@@ -2880,8 +2879,9 @@ static int neigh_dump_info(struct sk_buff *skb, struct netlink_callback *cb) 


	s_t = cb->args[0];



	rcu_read_lock();

	for (t = 0; t < NEIGH_NR_TABLES; t++) {

		tbl = neigh_tables[t];

		tbl = rcu_dereference(neigh_tables[t]);



		if (!tbl)

			continue;
@@ -2897,9 +2897,10 @@ static int neigh_dump_info(struct sk_buff *skb, struct netlink_callback *cb) 
		if (err < 0)

			break;

	}

	rcu_read_unlock();



	cb->args[0] = t;

	return skb->len;

	return err;

}



static int neigh_valid_get_req(const struct nlmsghdr *nlh,
@@ -3145,14 +3146,15 @@ int neigh_xmit(int index, struct net_device *dev, 
	       const void *addr, struct sk_buff *skb)

{

	int err = -EAFNOSUPPORT;



	if (likely(index < NEIGH_NR_TABLES)) {

		struct neigh_table *tbl;

		struct neighbour *neigh;



		tbl = neigh_tables[index];

		if (!tbl)

			goto out;

		rcu_read_lock();

		tbl = rcu_dereference(neigh_tables[index]);

		if (!tbl)

			goto out_unlock;

		if (index == NEIGH_ARP_TABLE) {

			u32 key = *((u32 *)addr);
@@ -3168,6 +3170,7 @@ int neigh_xmit(int index, struct net_device *dev, 
			goto out_kfree_skb;

		}

		err = READ_ONCE(neigh->output)(neigh, skb);

out_unlock:

		rcu_read_unlock();

	}

	else if (index == NEIGH_LINK_TABLE) {
@@ -3891,7 +3894,8 @@ static int __init neigh_init(void) 
{

	rtnl_register(PF_UNSPEC, RTM_NEWNEIGH, neigh_add, NULL, 0);

	rtnl_register(PF_UNSPEC, RTM_DELNEIGH, neigh_delete, NULL, 0);

	rtnl_register(PF_UNSPEC, RTM_GETNEIGH, neigh_get, neigh_dump_info, 0);

	rtnl_register(PF_UNSPEC, RTM_GETNEIGH, neigh_get, neigh_dump_info,

		      RTNL_FLAG_DUMP_UNLOCKED);



	rtnl_register(PF_UNSPEC, RTM_GETNEIGHTBL, NULL, neightbl_dump_info,

		      0);