[net-next,RFC PATCH] Introduce TC Range classifier

[Amritha Nambiar <amritha.nambiar@intel.com>]

This patch introduces a TC range classifier to support filtering based
on ranges. Only port-range filters are supported currently. This can
be combined with flower classifier to support filters that are a
combination of port-ranges and other parameters based on existing
fields supported by cls_flower. The 'goto chain' action can be used to
combine the flower and range filter.
The filter precedence is decided based on the 'prio' value.

Example:
1. Match on a port range:
-----------------------
$ tc filter add dev enp4s0 protocol ip parent ffff: prio 2 range\
ip_proto tcp dst_port 1-15 skip_hw action drop

$ tc -s filter show dev enp4s0 parent ffff:
filter protocol ip pref 2 range chain 0
filter protocol ip pref 2 range chain 0 handle 0x1
  eth_type ipv4
  ip_proto tcp
  dst_port_min 1
  dst_port_max 15
  skip_hw
  not_in_hw
        action order 1: gact action drop
         random type none pass val 0
         index 1 ref 1 bind 1 installed 34 sec used 2 sec
        Action statistics:
        Sent 1380 bytes 30 pkt (dropped 30, overlimits 0 requeues 0)
        backlog 0b 0p requeues 0

2. Match on IP address and port range:
--------------------------------------
$ tc filter add dev enp4s0 protocol ip parent ffff: prio 2 flower\
  dst_ip 192.168.1.1 skip_hw action goto chain 11

$ tc filter add dev enp4s0 protocol ip parent ffff: prio 2 chain 11\
  range ip_proto tcp dst_port 1-15 action drop

$ tc -s filter show dev enp4s0 parent ffff:
filter protocol ip pref 2 flower chain 0
filter protocol ip pref 2 flower chain 0 handle 0x1
  eth_type ipv4
  dst_ip 192.168.1.1
  skip_hw
  not_in_hw
        action order 1: gact action goto chain 11
         random type none pass val 0
         index 1 ref 1 bind 1 installed 1426 sec used 2 sec
        Action statistics:
        Sent 460 bytes 10 pkt (dropped 0, overlimits 0 requeues 0)
        backlog 0b 0p requeues 0

filter protocol ip pref 2 range chain 11
filter protocol ip pref 2 range chain 11 handle 0x1
  eth_type ipv4
  ip_proto tcp
  dst_port_min 1
  dst_port_max 15
  not_in_hw
        action order 1: gact action drop
         random type none pass val 0
         index 2 ref 1 bind 1 installed 1310 sec used 2 sec
        Action statistics:
        Sent 460 bytes 10 pkt (dropped 10, overlimits 0 requeues 0)
        backlog 0b 0p requeues 0
---

Amritha Nambiar (1):
      net: sched: cls_range: Introduce Range classifier


 include/uapi/linux/pkt_cls.h |   19 +
 net/sched/Kconfig            |   10 +
 net/sched/Makefile           |    1 
 net/sched/cls_range.c        |  725 ++++++++++++++++++++++++++++++++++++++++++
 4 files changed, 755 insertions(+)
 create mode 100644 net/sched/cls_range.c