Re: PROBLEM: Interface address change netlink socket problem.(Patch

[Vividh Siddha]

When you give
ifconfig eth0 10.10.10.50 netmask 0xffffff00 broadcast 10.10.10.255

It first calls devinet_ioctl() with cmd as SIOCSIFADDR. In this we reset 
netmask and broadcast address.

When devinet_ioctl() is called with SIOCSIFBRDADDR, the check for old 
address and new address suceeds as we changed the broadcast 
address(whereas it is unchanged). This then calls inet_del_ifa(delete 
notification) and then inet_insert_ifa(add notification).

Similarly when devinet_ioctl() is called with SIOCSIFNETMASK.

I tested this with the netlink socket with the patch applied and it 
works as expected.

Thanks,
vividh

David S. Miller wrote:
> Can you explain how not initializing some fields of the 'ifa'
> prevents the extra netlink messages?  I don't understand how
> your patch works.
> 
>