When there is no route to an IPv6 dest addr, skb_dst(skb) points
to loopback dev in the case of that the IP6CB(skb)->iif is
enslaved to a vrf. This causes Ip6InNoRoutes to be incremented on the
loopback dev. This also causes the lookup to fail on icmpv6_send() and
the dest unreachable to not sent and Ip6OutNoRoutes gets incremented on
the loopback dev.
To reproduce:
* Gateway configuration:
ip link add dev vrf_258 type vrf table 258
ip link set dev enp0s9 master vrf_258
ip addr add 66:1/64 dev enp0s9
ip -6 route add unreachable default metric 8192 table 258
sysctl -w net.ipv6.conf.all.forwarding=1
sysctl -w net.ipv6.conf.enp0s9.forwarding=1
* Sender configuration:
ip addr add 66::2/64 dev enp0s9
ip -6 route add default via 66::1
and ping 67::1 for example from the sender.
Fix this by counting on the original netdev and reset the skb dst to
force a fresh lookup.
v2: Fix typo of destination address in the repro steps.
v3: Simplify the loopback check (per David Ahern) and use reverse
Christmas tree format (per David Miller).
Signed-off-by: Stephen Suryaputra <ssuryaextr@gmail.com>
Reviewed-by: David Ahern <dsahern@gmail.com>
Tested-by: David Ahern <dsahern@gmail.com>
Reviewed-by: David Ahern <dsahern@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
1d3fd8a10b