[PATCHv3 net-next 0/5] net: eliminate the duplicate code in the ct nat functions of ovs and tc

[Xin Long <lucien.xin@gmail.com>]

The changes in the patchset:

  "net: add helper support in tc act_ct for ovs offloading"

had moved some common ct code used by both OVS and TC into netfilter.

There are still some big functions pretty similar defined and used in
each of OVS and TC. It is not good to maintain such big function in 2
places. This patchset is to extract the functions for NAT processing
from OVS and TC to netfilter.

To make this change clear and safe, this patchset gets the common code
out of OVS and TC step by step: The patch 1-4 make some minor changes
in OVS and TC to make the NAT code of them completely the same, then
the patch 5 moves the common code to the netfilter and exports one
function called by each of OVS and TC.

v1->v2:
  - Create nf_nat_ovs.c to include the nat functions, as Pablo suggested.
v2->v3:
  - Fix a typo in subject of patch 2/5, as Marcelo noticed.
  - Fix in openvswitch to keep OVS ct nat and TC ct nat consistent in
    patch 3/5 instead of in tc, as Marcelo noticed.
  - Use BIT(var) macro instead of (1 << var) in patch 5/5, as Marcelo
    suggested.
  - Use ifdef in netfilter/Makefile to build nf_nat_ovs only when OVS
    or TC ct action is enabled in patch 5/5, as Marcelo suggested.

Xin Long (5):
  openvswitch: delete the unncessary skb_pull_rcsum call in
    ovs_ct_nat_execute
  openvswitch: return NF_ACCEPT when OVS_CT_NAT is not set in info nat
  openvswitch: return NF_DROP when fails to add nat ext in ovs_ct_nat
  net: sched: update the nat flag for icmp error packets in
    ct_nat_execute
  net: move the nat function to nf_nat_ovs for ovs and tc

 include/net/netfilter/nf_nat.h |   4 +
 net/netfilter/Makefile         |   6 ++
 net/netfilter/nf_nat_ovs.c     | 135 ++++++++++++++++++++++++++++++
 net/openvswitch/conntrack.c    | 146 +++------------------------------
 net/sched/act_ct.c             | 136 +++---------------------------
 5 files changed, 169 insertions(+), 258 deletions(-)
 create mode 100644 net/netfilter/nf_nat_ovs.c

-- 
2.31.1