Commit 613f727c authored by Jakub Kicinski's avatar Jakub Kicinski
Browse files

Merge branch 'ipv6-multipath-routing-fixes' 

Ido Schimmel says:

====================
ipv6: Multipath routing fixes

This patchset contains two fixes for IPv6 multipath routing. See the
commit messages for more details.
====================

Link: https://patch.msgid.link/20250402114224.293392-1-idosch@nvidia.com


Signed-off-by: default avatarJakub Kicinski <kuba@kernel.org>
parents 51de3600 8b8e0dd3

net/ipv6/route.c

+38 −4
Original line number Diff line number Diff line
@@ -412,12 +412,37 @@ static bool rt6_check_expired(const struct rt6_info *rt) 
	return false;

}



static struct fib6_info *

rt6_multipath_first_sibling_rcu(const struct fib6_info *rt)

{

	struct fib6_info *iter;

	struct fib6_node *fn;



	fn = rcu_dereference(rt->fib6_node);

	if (!fn)

		goto out;

	iter = rcu_dereference(fn->leaf);

	if (!iter)

		goto out;



	while (iter) {

		if (iter->fib6_metric == rt->fib6_metric &&

		    rt6_qualify_for_ecmp(iter))

			return iter;

		iter = rcu_dereference(iter->fib6_next);

	}



out:

	return NULL;

}



void fib6_select_path(const struct net *net, struct fib6_result *res,

		      struct flowi6 *fl6, int oif, bool have_oif_match,

		      const struct sk_buff *skb, int strict)

{

	struct fib6_info *match = res->f6i;

	struct fib6_info *first, *match = res->f6i;

	struct fib6_info *sibling;

	int hash;



	if (!match->nh && (!match->fib6_nsiblings || have_oif_match))

		goto out;
@@ -440,16 +465,25 @@ void fib6_select_path(const struct net *net, struct fib6_result *res, 
		return;

	}



	if (fl6->mp_hash <= atomic_read(&match->fib6_nh->fib_nh_upper_bound))

	first = rt6_multipath_first_sibling_rcu(match);

	if (!first)

		goto out;



	list_for_each_entry_rcu(sibling, &match->fib6_siblings,

	hash = fl6->mp_hash;

	if (hash <= atomic_read(&first->fib6_nh->fib_nh_upper_bound) &&

	    rt6_score_route(first->fib6_nh, first->fib6_flags, oif,

			    strict) >= 0) {

		match = first;

		goto out;

	}



	list_for_each_entry_rcu(sibling, &first->fib6_siblings,

				fib6_siblings) {

		const struct fib6_nh *nh = sibling->fib6_nh;

		int nh_upper_bound;



		nh_upper_bound = atomic_read(&nh->fib_nh_upper_bound);

		if (fl6->mp_hash > nh_upper_bound)

		if (hash > nh_upper_bound)

			continue;

		if (rt6_score_route(nh, sibling->fib6_flags, oif, strict) < 0)

			break;