From: Eric Garver <eric@garver.life>
This adds an explicit drop action. This is used by OVS to drop packets
for which it cannot determine what to do. An explicit action in the
kernel allows passing the reason _why_ the packet is being dropped or
zero to indicate no particular error happened (i.e: OVS intentionally
dropped the packet).
Since the error codes coming from userspace mean nothing for the kernel,
we squash all of them into only two drop reasons:
- OVS_DROP_EXPLICIT_WITH_ERROR to indicate a non-zero value was passed
- OVS_DROP_EXPLICIT to indicate a zero value was passed (no error)
e.g. trace all OVS dropped skbs
# perf trace -e skb:kfree_skb --filter="reason >= 0x30000"
[..]
106.023 ping/2465 skb:kfree_skb(skbaddr: 0xffffa0e8765f2000, \
location:0xffffffffc0d9b462, protocol: 2048, reason: 196611)
reason: 196611 --> 0x30003 (OVS_DROP_EXPLICIT)
Also, this patch allows ovs-dpctl.py to add explicit drop actions as:
"drop" -> implicit empty-action drop
"drop(0)" -> explicit non-error action drop
"drop(42)" -> explicit error action drop
Signed-off-by: Eric Garver <eric@garver.life>
Co-developed-by: Adrian Moreno <amorenoz@redhat.com>
Signed-off-by: Adrian Moreno <amorenoz@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Add a drop reason for packets that are dropped because an action
returns a non-zero error code.
Acked-by: Aaron Conole <aconole@redhat.com>
Signed-off-by: Adrian Moreno <amorenoz@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Create a new drop reason subsystem for openvswitch and add the first
drop reason to represent last-action drops.
Last-action drops happen when a flow has an empty action list or there
is no action that consumes the packet (output, userspace, recirc, etc).
It is the most common way in which OVS drops packets.
Implementation-wise, most of these skb-consuming actions already call
"consume_skb" internally and return directly from within the
do_execute_actions() loop so with minimal changes we can assume that
any skb that exits the loop normally is a packet drop.
Signed-off-by: Adrian Moreno <amorenoz@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Eric Garver