From: Hangbin Liu liuhangbin@gmail.com
[ Upstream commit e9919a24d3022f72bcadc407e73a6ef17093a849 ]
With commit 153380ec4b9 ("fib_rules: Added NLM_F_EXCL support to fib_nl_newrule") we now able to check if a rule already exists. But this only works with iproute2. For other tools like libnl, NetworkManager, it still could add duplicate rules with only NLM_F_CREATE flag, like
[localhost ~ ]# ip rule 0: from all lookup local 32766: from all lookup main 32767: from all lookup default 100000: from 192.168.7.5 lookup 5 100000: from 192.168.7.5 lookup 5
As it doesn't make sense to create two duplicate rules, let's just return 0 if the rule exists.
Fixes: 153380ec4b9 ("fib_rules: Added NLM_F_EXCL support to fib_nl_newrule") Reported-by: Thomas Haller thaller@redhat.com Signed-off-by: Hangbin Liu liuhangbin@gmail.com Signed-off-by: David S. Miller davem@davemloft.net Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- net/core/fib_rules.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-)
--- a/net/core/fib_rules.c +++ b/net/core/fib_rules.c @@ -756,9 +756,9 @@ int fib_nl_newrule(struct sk_buff *skb, if (err) goto errout;
- if ((nlh->nlmsg_flags & NLM_F_EXCL) && - rule_exists(ops, frh, tb, rule)) { - err = -EEXIST; + if (rule_exists(ops, frh, tb, rule)) { + if (nlh->nlmsg_flags & NLM_F_EXCL) + err = -EEXIST; goto errout_free; }