Linux Kernel Networking and Development

In some cases 2 linked list can intersect each other. In the following diagram, you see that 2 NULL terminated singly linked lists are intersected at the node 5. In this implementation, we will find in which node the 2 lists are intersecting each other. The function will return the node address. We will use the helper functions form the previous post which add nodes to the lists, print the lists etc... Function which finds the intersection: /* * link_list_intersect() * Finds the intersection node of 2 lists. */ struct node * link_list_intersect ( struct node *list1, struct node *list2) { struct node *long_list; struct node *short_list; int diff = 0 ; /* * Get the lengths of the lists. */ int len1 = list_lenght_get(list1); int len2 = list_lenght_get(list2); /* * Find which list is long and which list is short * and find the absolute lenght difference. */ if (len1 >= len2) { diff = l...

In this post, you will see the implementation of a singly linked list. It is one of the main data structures in computer programming. A singly linked list consists of nodes which are bound to each other with their "next" pointers. A simple node is represented at least 2 fields. A "next" node pointer and a "data" field. /*   * node structure.   */ struct node { struct node *next; int data; }; Some of the basic methods of a linked list and node data structures are implemented below. Create a Node Method: /*   * node_create()   * Creates a node.   */ struct node *node_create( int data) {     struct node *n = malloc( sizeof ( struct node));     if (!n) {         printf( "Unable to allocate memory for node\n" );         return NULL ;     }     n->data = data;     n->next = NULL ; ...

In Linux programming, it is very important to debug your code by adding some debug messages to your code. By using the dynamic debug feature of Linux, you can enable these debug messages per file, per function and even per line.  This post will show you how to do this with a simple kernel loadable module implementation. First, you need compile your kernel with the CONFIG_DYNAMIC_DEBUG option. It is under " Kernel hacking " menu and prompt name is " E nable dynamic printk() support " as you see on the below screenshot. Sample Code: TBD Enable/Disable dynamic debug in the sample code: TBD