net: shell: Add network mgmt events monitor support

Add "net events [on|off]" command that can be used to monitor
the generated network management events.

The monitor output looks like this when enabled:

EVENT: L2 [1] up
EVENT: L3 [1] IPv6 mcast address add ff02::1:ff00:1
EVENT: L3 [1] IPv6 mcast join ff02::1:ff00:1
EVENT: L3 [1] IPv6 address add 2001:db8::1
EVENT: L4 [1] connected
EVENT: L3 [1] IPv6 prefix add 2002:5b9b:41a0::
EVENT: L3 [1] IPv6 address add 2002:5b9b:41a0:0:fec2:3dff:fe11:c147
EVENT: L3 [1] IPv6 neighbor add fe80::9ec7:a6ff:fe5e:4735
EVENT: L3 [1] IPv6 router add fe80::9ec7:a6ff:fe5e:4735
EVENT: L3 [1] IPv6 DAD ok fe80::fec2:3dff:fe11:c147
EVENT: L3 [1] IPv6 DAD ok 2001:db8::1
EVENT: L3 [1] IPv6 DAD ok 2002:5b9b:41a0:0:fec2:3dff:fe11:c147
EVENT: L3 [1] IPv4 address add 192.168.1.69
EVENT: L3 [1] DHCPv4 bound 192.168.1.69

Signed-off-by: Jukka Rissanen <jukka.rissanen@linux.intel.com>
4 files changed