Commit 1c32b24c authored by Florian Westphal's avatar Florian Westphal
Browse files

netfilter: nft_fib_ipv6: switch to fib6_lookup 



Existing code works but it requires a temporary dst object that is
released again right away.

Switch to fib6_lookup + RT6_LOOKUP_F_DST_NOREF: no need for temporary dst
objects and refcount overhead anymore.

Provides ~13% improvement in match performance.

Signed-off-by: default avatarFlorian Westphal <fw@strlen.de>
parent 831fb31b

net/ipv6/netfilter/nft_fib_ipv6.c

+49 −30
Original line number Diff line number Diff line
@@ -52,7 +52,13 @@ static int nft_fib6_flowi_init(struct flowi6 *fl6, const struct nft_fib *priv, 
	fl6->flowlabel = (*(__be32 *)iph) & IPV6_FLOWINFO_MASK;

	fl6->flowi6_l3mdev = nft_fib_l3mdev_master_ifindex_rcu(pkt, dev);



	return lookup_flags;

	return lookup_flags | RT6_LOOKUP_F_DST_NOREF;

}



static int nft_fib6_lookup(struct net *net, struct flowi6 *fl6,

			   struct fib6_result *res, int flags)

{

	return fib6_lookup(net, fl6->flowi6_oif, fl6, res, flags);

}



static u32 __nft_fib6_eval_type(const struct nft_fib *priv,
@@ -60,13 +66,14 @@ static u32 __nft_fib6_eval_type(const struct nft_fib *priv, 
				struct ipv6hdr *iph)

{

	const struct net_device *dev = NULL;

	struct fib6_result res = {};

	int route_err, addrtype;

	struct rt6_info *rt;

	struct flowi6 fl6 = {

		.flowi6_iif = LOOPBACK_IFINDEX,

		.flowi6_proto = pkt->tprot,

		.flowi6_uid = sock_net_uid(nft_net(pkt), NULL),

	};

	int lookup_flags;

	u32 ret = 0;



	if (priv->flags & NFTA_FIB_F_IIF)
@@ -74,29 +81,23 @@ static u32 __nft_fib6_eval_type(const struct nft_fib *priv, 
	else if (priv->flags & NFTA_FIB_F_OIF)

		dev = nft_out(pkt);



	nft_fib6_flowi_init(&fl6, priv, pkt, dev, iph);

	lookup_flags = nft_fib6_flowi_init(&fl6, priv, pkt, dev, iph);



	if (dev && nf_ipv6_chk_addr(nft_net(pkt), &fl6.daddr, dev, true))

		ret = RTN_LOCAL;



	route_err = nf_ip6_route(nft_net(pkt), (struct dst_entry **)&rt,

				 flowi6_to_flowi(&fl6), false);

	route_err = nft_fib6_lookup(nft_net(pkt), &fl6, &res, lookup_flags);

	if (route_err)

		goto err;



	if (rt->rt6i_flags & RTF_REJECT) {

		route_err = rt->dst.error;

		dst_release(&rt->dst);

		goto err;

	}

	if (res.fib6_flags & RTF_REJECT)

		return res.fib6_type;



	if (ipv6_anycast_destination((struct dst_entry *)rt, &fl6.daddr))

	if (__ipv6_anycast_destination(&res.f6i->fib6_dst, res.fib6_flags, &fl6.daddr))

		ret = RTN_ANYCAST;

	else if (!dev && rt->rt6i_flags & RTF_LOCAL)

	else if (!dev && res.fib6_flags & RTF_LOCAL)

		ret = RTN_LOCAL;



	dst_release(&rt->dst);



	if (ret)

		return ret;
@@ -152,6 +153,33 @@ static bool nft_fib_v6_skip_icmpv6(const struct sk_buff *skb, u8 next, const str 
	return ipv6_addr_type(&iph->daddr) & IPV6_ADDR_LINKLOCAL;

}



static bool nft_fib6_info_nh_dev_match(const struct net_device *nh_dev,

				       const struct net_device *dev)

{

	return nh_dev == dev ||

	       l3mdev_master_ifindex_rcu(nh_dev) == dev->ifindex;

}



static bool nft_fib6_info_nh_uses_dev(struct fib6_info *rt,

				      const struct net_device *dev)

{

	const struct net_device *nh_dev;

	struct fib6_info *iter;



	nh_dev = fib6_info_nh_dev(rt);

	if (nft_fib6_info_nh_dev_match(nh_dev, dev))

		return true;



	list_for_each_entry(iter, &rt->fib6_siblings, fib6_siblings) {

		nh_dev = fib6_info_nh_dev(iter);



		if (nft_fib6_info_nh_dev_match(nh_dev, dev))

			return true;

	}



	return false;

}



void nft_fib6_eval(const struct nft_expr *expr, struct nft_regs *regs,

		   const struct nft_pktinfo *pkt)

{
@@ -160,14 +188,14 @@ void nft_fib6_eval(const struct nft_expr *expr, struct nft_regs *regs, 
	const struct net_device *found = NULL;

	const struct net_device *oif = NULL;

	u32 *dest = &regs->data[priv->dreg];

	struct fib6_result res = {};

	struct ipv6hdr *iph, _iph;

	struct flowi6 fl6 = {

		.flowi6_iif = LOOPBACK_IFINDEX,

		.flowi6_proto = pkt->tprot,

		.flowi6_uid = sock_net_uid(nft_net(pkt), NULL),

	};

	struct rt6_info *rt;

	int lookup_flags;

	int lookup_flags, ret;



	if (nft_fib_can_skip(pkt)) {

		nft_fib_store_result(dest, priv, nft_in(pkt));
@@ -193,26 +221,17 @@ void nft_fib6_eval(const struct nft_expr *expr, struct nft_regs *regs, 
	lookup_flags = nft_fib6_flowi_init(&fl6, priv, pkt, oif, iph);



	*dest = 0;

	rt = (void *)ip6_route_lookup(nft_net(pkt), &fl6, pkt->skb,

				      lookup_flags);

	if (rt->dst.error)

		goto put_rt_err;



	/* Should not see RTF_LOCAL here */

	if (rt->rt6i_flags & (RTF_REJECT | RTF_ANYCAST | RTF_LOCAL))

		goto put_rt_err;

	ret = nft_fib6_lookup(nft_net(pkt), &fl6, &res, lookup_flags);

	if (ret || res.fib6_flags & (RTF_REJECT | RTF_ANYCAST | RTF_LOCAL))

		return;



	if (!oif) {

		found = rt->rt6i_idev->dev;

		found = fib6_info_nh_dev(res.f6i);

	} else {

		if (oif == rt->rt6i_idev->dev ||

		    l3mdev_master_ifindex_rcu(rt->rt6i_idev->dev) == oif->ifindex)

		if (nft_fib6_info_nh_uses_dev(res.f6i, oif))

			found = oif;

	}



	nft_fib_store_result(dest, priv, found);

 put_rt_err:

	ip6_rt_put(rt);

}

EXPORT_SYMBOL_GPL(nft_fib6_eval);