Commit 9cc4cc32 authored by Eric Dumazet's avatar Eric Dumazet Committed by David S. Miller
Browse files

ipv6: use xa_array iterator to implement inet6_dump_addr() 



inet6_dump_addr() can use the new xa_array iterator
for better scalability.

Make it ready for RCU-only protection.
RTNL use is removed in the following patch.

Also properly return 0 at the end of a dump to avoid
and extra recvmsg() to get NLMSG_DONE.

Signed-off-by: default avatarEric Dumazet <edumazet@google.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 46f5182d

net/ipv6/addrconf.c

+30 −49
Original line number Diff line number Diff line
@@ -717,7 +717,7 @@ static int inet6_netconf_get_devconf(struct sk_buff *in_skb, 
static u32 inet6_base_seq(const struct net *net)

{

	u32 res = atomic_read(&net->ipv6.dev_addr_genid) +

		  net->dev_base_seq;

		  READ_ONCE(net->dev_base_seq);



	/* Must not return 0 (see nl_dump_check_consistent()).

	 * Chose a value far away from 0.
@@ -5272,13 +5272,13 @@ static int inet6_fill_ifacaddr(struct sk_buff *skb, 


/* called with rcu_read_lock() */

static int in6_dump_addrs(const struct inet6_dev *idev, struct sk_buff *skb,

			  struct netlink_callback *cb, int s_ip_idx,

			  struct netlink_callback *cb, int *s_ip_idx,

			  struct inet6_fill_args *fillargs)

{

	const struct ifmcaddr6 *ifmca;

	const struct ifacaddr6 *ifaca;

	int ip_idx = 0;

	int err = 1;

	int err = 0;



	switch (fillargs->type) {

	case UNICAST_ADDR: {
@@ -5287,7 +5287,7 @@ static int in6_dump_addrs(const struct inet6_dev *idev, struct sk_buff *skb, 


		/* unicast address incl. temp addr */

		list_for_each_entry_rcu(ifa, &idev->addr_list, if_list) {

			if (ip_idx < s_ip_idx)

			if (ip_idx < *s_ip_idx)

				goto next;

			err = inet6_fill_ifaddr(skb, ifa, fillargs);

			if (err < 0)
@@ -5305,7 +5305,7 @@ static int in6_dump_addrs(const struct inet6_dev *idev, struct sk_buff *skb, 
		for (ifmca = rcu_dereference(idev->mc_list);

		     ifmca;

		     ifmca = rcu_dereference(ifmca->next), ip_idx++) {

			if (ip_idx < s_ip_idx)

			if (ip_idx < *s_ip_idx)

				continue;

			err = inet6_fill_ifmcaddr(skb, ifmca, fillargs);

			if (err < 0)
@@ -5317,7 +5317,7 @@ static int in6_dump_addrs(const struct inet6_dev *idev, struct sk_buff *skb, 
		/* anycast address */

		for (ifaca = rcu_dereference(idev->ac_list); ifaca;

		     ifaca = rcu_dereference(ifaca->aca_next), ip_idx++) {

			if (ip_idx < s_ip_idx)

			if (ip_idx < *s_ip_idx)

				continue;

			err = inet6_fill_ifacaddr(skb, ifaca, fillargs);

			if (err < 0)
@@ -5327,7 +5327,7 @@ static int in6_dump_addrs(const struct inet6_dev *idev, struct sk_buff *skb, 
	default:

		break;

	}

	cb->args[2] = ip_idx;

	*s_ip_idx = err ? ip_idx : 0;

	return err;

}
@@ -5390,6 +5390,7 @@ static int inet6_valid_dump_ifaddr_req(const struct nlmsghdr *nlh, 
static int inet6_dump_addr(struct sk_buff *skb, struct netlink_callback *cb,

			   enum addr_type_t type)

{

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

	const struct nlmsghdr *nlh = cb->nlh;

	struct inet6_fill_args fillargs = {

		.portid = NETLINK_CB(cb->skb).portid,
@@ -5398,72 +5399,52 @@ static int inet6_dump_addr(struct sk_buff *skb, struct netlink_callback *cb, 
		.netnsid = -1,

		.type = type,

	};

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

	int idx, s_idx, s_ip_idx;

	int h, s_h;

	struct {

		unsigned long ifindex;

		int ip_idx;

	} *ctx = (void *)cb->ctx;

	struct net_device *dev;

	struct inet6_dev *idev;

	struct hlist_head *head;

	int err = 0;



	s_h = cb->args[0];

	s_idx = idx = cb->args[1];

	s_ip_idx = cb->args[2];



	rcu_read_lock();

	if (cb->strict_check) {

		err = inet6_valid_dump_ifaddr_req(nlh, &fillargs, &tgt_net,

						  skb->sk, cb);

		if (err < 0)

			goto put_tgt_net;

			goto done;



		err = 0;

		if (fillargs.ifindex) {

			dev = __dev_get_by_index(tgt_net, fillargs.ifindex);

			if (!dev) {

			err = -ENODEV;

				goto put_tgt_net;

			}

			dev = dev_get_by_index_rcu(tgt_net, fillargs.ifindex);

			if (!dev)

				goto done;

			idev = __in6_dev_get(dev);

			if (idev) {

				err = in6_dump_addrs(idev, skb, cb, s_ip_idx,

			if (idev)

				err = in6_dump_addrs(idev, skb, cb,

						     &ctx->ip_idx,

						     &fillargs);

				if (err > 0)

					err = 0;

			}

			goto put_tgt_net;

			goto done;

		}

	}



	cb->seq = inet6_base_seq(tgt_net);

	for (h = s_h; h < NETDEV_HASHENTRIES; h++, s_idx = 0) {

		idx = 0;

		head = &tgt_net->dev_index_head[h];

		hlist_for_each_entry_rcu(dev, head, index_hlist) {

			if (idx < s_idx)

				goto cont;

			if (h > s_h || idx > s_idx)

				s_ip_idx = 0;

	for_each_netdev_dump(tgt_net, dev, ctx->ifindex) {

		idev = __in6_dev_get(dev);

		if (!idev)

				goto cont;



			if (in6_dump_addrs(idev, skb, cb, s_ip_idx,

					   &fillargs) < 0)

			continue;

		err = in6_dump_addrs(idev, skb, cb, &ctx->ip_idx,

				     &fillargs);

		if (err < 0)

			goto done;

cont:

			idx++;

		}

	}

done:

	cb->args[0] = h;

	cb->args[1] = idx;

put_tgt_net:

	rcu_read_unlock();

	if (fillargs.netnsid >= 0)

		put_net(tgt_net);



	return skb->len ? : err;

	return err;

}



static int inet6_dump_ifaddr(struct sk_buff *skb, struct netlink_callback *cb)