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>
153380ec4b