Merge branch 'net-sched-multichain-filters'

Merge branch 'net-sched-multichain-filters'

Jiri Pirko says:

====================
net: sched: introduce multichain support for filters

Currently, each classful qdisc holds one chain of filters.
This chain is traversed and each filter could be matched on, which
may lead to execution of list of actions. One of such action
could be "reclassify", which would "reset" the processing of the
filter chain.

So this filter chain could be looked at as a flat table.
Sometimes it is convenient for user to configure a hierarchy
of tables. Example usecase is encapsulation.

Hierarchy of tables is a common way how it is done in HW pipelines.
So it is much more convenient to offload this.

This patchset contains two major patches:
8/10 - This patch introduces the support for having multiple
       chains of filters.
10/10 - This patch adds new control action to allow going to specified chain

The rest of the patches are smaller or bigger depencies of those 2.
Please see individual patch descriptions for details.

Corresponding iproute2 patches are appended as a reply to this cover letter.

Simple example:
$ tc qdisc add dev eth0 ingress
$ tc filter add dev eth0 parent ffff: protocol ip pref 33 flower dst_mac 52:54:00:3d:c7:6d action goto chain 11
$ tc filter add dev eth0 parent ffff: protocol ip pref 22 chain 11 flower dst_ip 192.168.40.1 action drop
$ tc filter show dev eth0 root
filter parent ffff: protocol ip pref 33 flower chain 0
filter parent ffff: protocol ip pref 33 flower chain 0 handle 0x1
  dst_mac 52:54:00:3d:c7:6d
  eth_type ipv4
        action order 1: gact action goto chain 11
         random type none pass val 0
         index 2 ref 1 bind 1

filter parent ffff: protocol ip pref 22 flower chain 11
filter parent ffff: protocol ip pref 22 flower chain 11 handle 0x1
  eth_type ipv4
  dst_ip 192.168.40.1
        action order 1: gact action drop
         random type none pass val 0
         index 3 ref 1 bind 1
====================

Signed-off-by: David S. Miller <davem@davemloft.net>