The netmask should be tied to the IPv4 address instead of being
global for the network interface.
If there is only one IPv4 address specified to the network interface,
nothing changes from user point of view. But if there are more than
one IPv4 address / network interface, the netmask must be specified
to each address separately.
This means that net_if_ipv4_get_netmask() and net_if_ipv4_set_netmask()
functions should not be used as they only work reliably if there is
only one IPv4 address in the network interface.
The new net_if_ipv4_get_netmask_by_addr() and
net_if_ipv4_set_netmask_by_addr() functions should be used as they make
sure that the netmask is tied to correct IPv4 address in the network
interface.
Signed-off-by: Jukka Rissanen <jukka.rissanen@nordicsemi.no>
1b0f9e865e