Patch for VYOS kernel module


I am new to VyOS development. I have written a simple educational patch, which will fetch info from VyOS conntracking module and write it on a netlink socket.But the problem is I am not sure whether

  1. Can I edit the kernel module code directly to call my defined function or I have to write the patch.

  2. If I have to make a patch file for it then where to place it in kernel source code. I have already made a patch file using diff command.

I have written some printk(KERN_INFO " "); function in ip_rcv() function in net/ipv4/ip_input.c file. But I can’t see its output. I use show log and monitor log command to check the output of printk() function.

I have searched a lot about this problem but couldn’t find the satisfactory solution. Kindly help me.

Thanks in advance.