tc: flower: Classify packets based port ranges

tc: flower: Classify packets based port ranges

Added support for filtering based on port ranges.
UAPI changes have been accepted into net-next.

Example:
1. Match on a port range:
-------------------------
$ tc filter add dev enp4s0 protocol ip parent ffff:\
  prio 1 flower ip_proto tcp dst_port 20-30 skip_hw\
  action drop

$ tc -s filter show dev enp4s0 parent ffff:
filter protocol ip pref 1 flower chain 0
filter protocol ip pref 1 flower chain 0 handle 0x1
  eth_type ipv4
  ip_proto tcp
  dst_port 20-30
  skip_hw
  not_in_hw
        action order 1: gact action drop
         random type none pass val 0
         index 1 ref 1 bind 1 installed 85 sec used 3 sec
        Action statistics:
        Sent 460 bytes 10 pkt (dropped 10, 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 1 flower dst_ip 192.168.1.1 ip_proto tcp dst_port 100-200\
  skip_hw action drop

$ tc -s filter show dev enp4s0 parent ffff:
filter protocol ip pref 1 flower chain 0 handle 0x2
  eth_type ipv4
  ip_proto tcp
  dst_ip 192.168.1.1
  dst_port 100-200
  skip_hw
  not_in_hw
        action order 1: gact action drop
         random type none pass val 0
         index 2 ref 1 bind 1 installed 58 sec used 2 sec
        Action statistics:
        Sent 920 bytes 20 pkt (dropped 20, overlimits 0 requeues 0)
        backlog 0b 0p requeues 0

v6:
Modified to change json output format as object for sport/dport.

 "dst_port":{
           "start":2000,
           "end":6000
 },
 "src_port":{
           "start":50,
           "end":60
 }

v5:
Simplified some code and used 'sscanf' for parsing. Removed
space in output format.

v4:
Added man updates explaining filtering based on port ranges.
Removed 'range' keyword.

v3:
Modified flower_port_range_attr_type calls.

v2:
Addressed Jiri's comment to sync output format with input

Signed-off-by: Amritha Nambiar <amritha.nambiar@intel.com>
Signed-off-by: David Ahern <dsahern@gmail.com>