Internet Not working eh? How Ubuntu Resolves DNS?

Problem I upgraded my Ubuntu from 16.04 to 18. And the Internet stopped working. 😦 I tried rebooting interface, adding a new interface to ifconfig. But it did not help. What helped was an answer on AskUbuntu How it worked? The answer is in how Ubuntu lookup domains like http://www.google.com. Step 1 Check the domain … More Internet Not working eh? How Ubuntu Resolves DNS?

Netlink Sockets: Addind a new socket family

Kernel version 3.13, Ubuntu 14.04 $ uname -a Linux ubuntu 3.13.0-37-generic #64-Ubuntu SMP Mon Sep 22 21:28:38 UTC 2014 x86_64 x86_64 x86_64 GNU/Linux We need two changes: User space Locate the file “netlink.h” $ sudo locate “netlink.h” You would get the header file at “/usr/include/linux/netlink.h” Add the new family #define NETLINK_MY     17 Keep … More Netlink Sockets: Addind a new socket family

Linux Device Driver Development: Block Device Driver

It is my very first interaction with Linux kernel at device driver level. My objective is to develop a block device driver, very simple, that just forward I/O requests to a virtual device. This post explains my observations limited to attacking the problem. Block v/s Character Device Linux support block and character device drivers. Only … More Linux Device Driver Development: Block Device Driver