My requirement is to implement(insert ) an ip address validation step in kernel.. Once any of the interface is up and got ip, then my validation should happen..
So as the first step , in source code (linux 2.6 source code I downloaded ) , in which file I need to trace
The kernel is the wrong place for this unless you’re doing something embedded with a teeny tiny footprint. What you really want is ifplugd.
However, if you absolutely insist on having it be in the kernel – take a look at the kernel bits that get enabled when CONFIG_IP_PNP=y