Commit 153380ec authored Jun 29, 2016 by Mateusz Bajorski Committed by David S. Miller Jun 30, 2016

fib_rules: Added NLM_F_EXCL support to fib_nl_newrule

When adding rule with NLM_F_EXCL flag then check if the same rule exist.
If yes then exit with -EEXIST.

This is already implemented in iproute2:
        if (cmd == RTM_NEWRULE) {
                req.n.nlmsg_flags |= NLM_F_CREATE|NLM_F_EXCL;
                req.r.rtm_type = RTN_UNICAST;
        }

Tested ipv4 and ipv6 with net-next linux on qemu x86

expected behavior after patch:
localhost ~ # ip rule
0:    from all lookup local
32766:    from all lookup main
32767:    from all lookup default
localhost ~ # ip rule add from 10.46.177.97 lookup 104 pref 1005
localhost ~ # ip rule add from 10.46.177.97 lookup 104 pref 1005
RTNETLINK answers: File exists
localhost ~ # ip rule
0:    from all lookup local
1005:    from 10.46.177.97 lookup 104
32766:    from all lookup main
32767:    from all lookup default

There was already topic regarding this but I don't see any changes
merged and problem still occurs.
https://lkml.kernel.org/r/1135778809.5944.7.camel+%28%29+localhost+%21+localdomain



Signed-off-by: Mateusz Bajorski <mateusz.bajorski@nokia.com>
Acked-by: David Ahern <dsa@cumulusnetworks.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

parent 2631b79f

net/core/fib_rules.c

+49 −0

Original line number	Diff line number	Diff line
		@@ -269,6 +269,49 @@ errout:
		return err;
		}

		static int rule_exists(struct fib_rules_ops ops, struct fib_rule_hdr frh,
		struct nlattr *tb, struct fib_rule rule)
		{
		struct fib_rule *r;

		list_for_each_entry(r, &ops->rules_list, list) {
		if (r->action != rule->action)
		continue;

		if (r->table != rule->table)
		continue;

		if (r->pref != rule->pref)
		continue;

		if (memcmp(r->iifname, rule->iifname, IFNAMSIZ))
		continue;

		if (memcmp(r->oifname, rule->oifname, IFNAMSIZ))
		continue;

		if (r->mark != rule->mark)
		continue;

		if (r->mark_mask != rule->mark_mask)
		continue;

		if (r->tun_id != rule->tun_id)
		continue;

		if (r->fr_net != rule->fr_net)
		continue;

		if (r->l3mdev != rule->l3mdev)
		continue;

		if (!ops->compare(r, frh, tb))
		continue;
		return 1;
		}
		return 0;
		}

		int fib_nl_newrule(struct sk_buff skb, struct nlmsghdr nlh)
		{
		struct net *net = sock_net(skb->sk);
		@@ -386,6 +429,12 @@ int fib_nl_newrule(struct sk_buff skb, struct nlmsghdr nlh)
		if (rule->l3mdev && rule->table)
		goto errout_free;

		if ((nlh->nlmsg_flags & NLM_F_EXCL) &&
		rule_exists(ops, frh, tb, rule)) {
		err = -EEXIST;
		goto errout_free;
		}

		err = ops->configure(rule, skb, frh, tb);
		if (err < 0)
		goto errout_free;

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