Commit 88b9cfca authored by Kuniyuki Iwashima's avatar Kuniyuki Iwashima Committed by Jakub Kicinski
Browse files

net: fib_rules: Convert RTM_DELRULE to per-netns RTNL. 



fib_nl_delrule() is the doit() handler for RTM_DELRULE but also called
from vrf_newlink() in case something fails in vrf_add_fib_rules().

In the latter case, RTNL is already held and the 4th arg is true.

Let's hold per-netns RTNL in fib_delrule() if rtnl_held is false.

Now we can place ASSERT_RTNL_NET() in call_fib_rule_notifiers().

Signed-off-by: default avatarKuniyuki Iwashima <kuniyu@amazon.com>
Reviewed-by: default avatarEric Dumazet <edumazet@google.com>
Reviewed-by: default avatarIdo Schimmel <idosch@nvidia.com>
Tested-by: default avatarIdo Schimmel <idosch@nvidia.com>
Link: https://patch.msgid.link/20250207072502.87775-9-kuniyu@amazon.com


Signed-off-by: default avatarJakub Kicinski <kuba@kernel.org>
parent 1cf770da

net/core/fib_rules.c

+16 −7
Original line number Diff line number Diff line
@@ -371,7 +371,8 @@ static int call_fib_rule_notifiers(struct net *net, 
		.rule = rule,

	};



	ASSERT_RTNL();

	ASSERT_RTNL_NET(net);



	/* Paired with READ_ONCE() in fib_rules_seq() */

	WRITE_ONCE(ops->fib_rules_seq, ops->fib_rules_seq + 1);

	return call_fib_notifiers(net, event_type, &info.info);
@@ -944,6 +945,9 @@ int fib_delrule(struct net *net, struct sk_buff *skb, struct nlmsghdr *nlh, 
	if (err)

		goto errout;



	if (!rtnl_held)

		rtnl_net_lock(net);



	err = fib_nl2rule_rtnl(nlrule, ops, tb, extack);

	if (err)

		goto errout_free;
@@ -998,10 +1002,12 @@ int fib_delrule(struct net *net, struct sk_buff *skb, struct nlmsghdr *nlh, 
		}

	}



	call_fib_rule_notifiers(net, FIB_EVENT_RULE_DEL, rule, ops,

				NULL);

	notify_rule_change(RTM_DELRULE, rule, ops, nlh,

			   NETLINK_CB(skb).portid);

	call_fib_rule_notifiers(net, FIB_EVENT_RULE_DEL, rule, ops, NULL);



	if (!rtnl_held)

		rtnl_net_unlock(net);



	notify_rule_change(RTM_DELRULE, rule, ops, nlh, NETLINK_CB(skb).portid);

	fib_rule_put(rule);

	flush_route_cache(ops);

	rules_ops_put(ops);
@@ -1009,6 +1015,8 @@ int fib_delrule(struct net *net, struct sk_buff *skb, struct nlmsghdr *nlh, 
	return 0;



errout_free:

	if (!rtnl_held)

		rtnl_net_unlock(net);

	kfree(nlrule);

errout:

	rules_ops_put(ops);
@@ -1019,7 +1027,7 @@ EXPORT_SYMBOL_GPL(fib_delrule); 
static int fib_nl_delrule(struct sk_buff *skb, struct nlmsghdr *nlh,

			  struct netlink_ext_ack *extack)

{

	return fib_delrule(sock_net(skb->sk), skb, nlh, extack, true);

	return fib_delrule(sock_net(skb->sk), skb, nlh, extack, false);

}



static inline size_t fib_rule_nlmsg_size(struct fib_rules_ops *ops,
@@ -1334,7 +1342,8 @@ static struct pernet_operations fib_rules_net_ops = { 
static const struct rtnl_msg_handler fib_rules_rtnl_msg_handlers[] __initconst = {

	{.msgtype = RTM_NEWRULE, .doit = fib_nl_newrule,

	 .flags = RTNL_FLAG_DOIT_PERNET},

	{.msgtype = RTM_DELRULE, .doit = fib_nl_delrule},

	{.msgtype = RTM_DELRULE, .doit = fib_nl_delrule,

	 .flags = RTNL_FLAG_DOIT_PERNET},

	{.msgtype = RTM_GETRULE, .dumpit = fib_nl_dumprule,

	 .flags = RTNL_FLAG_DUMP_UNLOCKED},

};