Redundant DHCP Request checks

[Yuli]

In short we check all packets coming from routers and from VMs for DHCP IP resolution.
We need this check only for packets coming from VMs.

Technical explanation:
By default, all packets coming from virtual routers and from VMs is forwarded to OVS table 9.

One of the checks in this table is to check that the packet is DHCP IP resolution request that later is forwarded to CONTROLLER.

Basically all packet received from all interfaces (routers and VMs) pass this check.

We just need to check packets coming from VMs. All other checks are redundant.

Example:
table=0, n_packets=9, n_bytes=872, priority=100,in_port=1 actions=set_field:0x1->reg6,set_field:0x1->metadata,goto_table:9
table=0, n_packets=1593, n_bytes=175246, priority=100,in_port=2 actions=set_field:0x3->reg6,set_field:0x1->metadata,goto_table:9
table=0, n_packets=16, n_bytes=1685, priority=100,in_port=3 actions=set_field:0x4->reg6,set_field:0x1->metadata,goto_table:9

In table 9:
table=9, n_packets=2, n_bytes=672, priority=100,udp,dl_dst=ff:ff:ff:ff:ff:ff,tp_src=68,tp_dst=67 actions=goto_table:11

Where port1, port2, port3:
 1(qr-f5fac1e2-29): addr:00:00:00:00:00:00
 2(qr-6bb13220-73): addr:00:00:00:00:00:00
 3(tap1ce66674-4f): addr:fe:16:3e:4f:5d:09

We just need to check only for port3: tap1ce66674-4f

Thanks

Yuli

[Gal Sagie (gal-sagie)]

We need to check if we can apply an optimization to not send all flows to table 9 (for example we might not need to send router ports to that table)