Assignment added for 20 min course

WheelTimer/Assignment/compile.sh

@@ -0,0 +1,5 @@
+rm *o
+rm *exe
+gcc -g -c rt.c -o rt.o
+gcc -g -c rt_entry_expiration.c -o rt_entry_expiration.o
+gcc -g rt_entry_expiration.o rt.o -o rt_entry_expiration.exe

WheelTimer/Assignment/rt.c

@@ -0,0 +1,134 @@
+/*
+ * =====================================================================================
+ *
+ *       Filename:  rt.h
+ *
+ *    Description:  
+ *
+ *        Version:  1.0
+ *        Created:  02/22/2020 06:14:33 AM
+ *       Revision:  none
+ *       Compiler:  gcc
+ *
+ *         Author:  Er. Abhishek Sagar, Juniper Networks (https://csepracticals.wixsite.com/csepracticals), sachinites@gmail.com
+ *        Company:  Juniper Networks
+ *
+ *        This file is part of the Netlink Sockets distribution (https://github.com/sachinites) 
+ *        Copyright (c) 2019 Abhishek Sagar.
+ *        This program is free software: you can redistribute it and/or modify it under the terms of the GNU General 
+ *        Public License as published by the Free Software Foundation, version 3.
+ *        
+ *        This program is distributed in the hope that it will be useful, but
+ *        WITHOUT ANY WARRANTY; without even the implied warranty of
+ *        MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ *        General Public License for more details.
+ *
+ *        visit website : https://csepracticals.wixsite.com/csepracticals for more courses and projects
+ *                                  
+ * =====================================================================================
+ */
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <memory.h>
+#include "rt.h"
+
+void
+rt_init_rt_table(rt_table_t *rt_table){
+
+    rt_table->head = NULL;
+}
+
+bool
+rt_add_new_rt_entry(rt_table_t *rt_table,
+                    char *dest, 
+                    char mask, 
+                    char *gw_ip, 
+                    char *oif){
+
+    rt_entry_t *head = NULL;
+    rt_entry_t *rt_entry = NULL;
+
+    rt_entry = calloc(1, sizeof(rt_entry_t));
+
+    if(!rt_entry)
+        return false;
+
+    strncpy(rt_entry->rt_entry_keys.dest, dest, sizeof(rt_entry->rt_entry_keys.dest));
+    rt_entry->rt_entry_keys.mask = mask;
+    
+    if(gw_ip)
+        strncpy(rt_entry->gw_ip, gw_ip, sizeof(rt_entry->gw_ip));
+    if(oif)
+        strncpy(rt_entry->oif, oif, sizeof(rt_entry->oif));
+	
+	rt_entry->time_to_expire = RT_TABLE_EXP_TIME;
+
+    head = rt_table->head;
+    rt_table->head = rt_entry;
+    rt_entry->prev = 0;
+    rt_entry->next = head;
+    if(head)
+    head->prev = rt_entry;
+    return true;
+}
+
+bool
+rt_delete_rt_entry(rt_table_t *rt_table,
+    char *dest, char mask){
+
+    rt_entry_t *rt_entry = NULL;
+
+    ITERTAE_RT_TABLE_BEGIN(rt_table, rt_entry){
+    
+        if(strncmp(rt_entry->rt_entry_keys.dest, 
+            dest, sizeof(rt_entry->rt_entry_keys.dest)) == 0 &&
+            rt_entry->rt_entry_keys.mask == mask){
+
+            rt_entry_remove(rt_table, rt_entry);
+            free(rt_entry);
+            return true;
+        }
+    } ITERTAE_RT_TABLE_END(rt_table, curr);
+
+    return false;
+}
+
+bool
+rt_update_rt_entry(rt_table_t *rt_table,
+                  char *dest, 
+                  char mask, 
+                  char *new_gw_ip, 
+                  char *new_oif){
+
+    return true;
+}
+
+void
+rt_clear_rt_table(rt_table_t *rt_table){
+
+
+}
+
+void
+rt_free_rt_table(rt_table_t *rt_table){
+
+
+}
+
+void
+rt_dump_rt_table(rt_table_t *rt_table){
+
+    rt_entry_t *rt_entry = NULL;
+
+    ITERTAE_RT_TABLE_BEGIN(rt_table, rt_entry){
+
+        printf("%-20s %-4d %-20s %-12s %usec\n",
+            rt_entry->rt_entry_keys.dest, 
+            rt_entry->rt_entry_keys.mask, 
+            rt_entry->gw_ip,
+            rt_entry->oif,
+			rt_entry->time_to_expire);
+    } ITERTAE_RT_TABLE_END(rt_tabl, rt_entry);
+}

WheelTimer/Assignment/rt.h

@@ -0,0 +1,124 @@
+/*
+ * =====================================================================================
+ *
+ *       Filename:  rt.h
+ *
+ *    Description:  
+ *
+ *        Version:  1.0
+ *        Created:  02/22/2020 06:14:33 AM
+ *       Revision:  none
+ *       Compiler:  gcc
+ *
+ *         Author:  Er. Abhishek Sagar, Juniper Networks (https://csepracticals.wixsite.com/csepracticals), sachinites@gmail.com
+ *        Company:  Juniper Networks
+ *
+ *        This file is part of the Netlink Sockets distribution (https://github.com/sachinites) 
+ *        Copyright (c) 2019 Abhishek Sagar.
+ *        This program is free software: you can redistribute it and/or modify it under the terms of the GNU General 
+ *        Public License as published by the Free Software Foundation, version 3.
+ *        
+ *        This program is distributed in the hope that it will be useful, but
+ *        WITHOUT ANY WARRANTY; without even the implied warranty of
+ *        MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ *        General Public License for more details.
+ *
+ *        visit website : https://csepracticals.wixsite.com/csepracticals for more courses and projects
+ *                                  
+ * =====================================================================================
+ */
+
+#ifndef __RT__
+#define __RT__
+
+#include <stdint.h>
+#include <stdbool.h>
+
+#define RT_TABLE_EXP_TIME	30  /*  30 sec */
+
+
+typedef struct rt_entry_keys_{
+
+    char dest[16];
+    char mask;
+} rt_entry_keys_t;
+
+typedef struct rt_entry_{
+
+    /* A Structure which represents only the keys of the
+     * Routing Table.*/
+    rt_entry_keys_t rt_entry_keys;
+
+    char gw_ip[16];
+    char oif[32];
+	uint32_t time_to_expire; /* time left to delete the entry */
+    struct rt_entry_ *prev;
+    struct rt_entry_ *next;
+} rt_entry_t;
+
+typedef struct rt_table_{
+
+    rt_entry_t *head;
+} rt_table_t;
+
+void
+rt_init_rt_table(rt_table_t *rt_table);
+
+bool
+rt_add_new_rt_entry(rt_table_t *rt_table,
+    char *dest_ip, char mask, char *gw_ip, char *oif);
+
+bool
+rt_delete_rt_entry(rt_table_t *rt_table,
+    char *dest_ip, char mask);
+
+bool
+rt_update_rt_entry(rt_table_t *rt_table,
+    char *dest_ip, char mask, 
+    char *new_gw_ip, char *new_oif);
+
+void
+rt_clear_rt_table(rt_table_t *rt_table);
+
+void
+rt_free_rt_table(rt_table_t *rt_table);
+
+void
+rt_dump_rt_table(rt_table_t *rt_table);
+
+static inline void
+rt_entry_remove(rt_table_t *rt_table,
+                rt_entry_t *rt_entry){
+
+    if(!rt_entry->prev){
+        if(rt_entry->next){
+            rt_entry->next->prev = 0;
+            rt_table->head = rt_entry->next;
+            rt_entry->next = 0;
+            return;
+        }
+        return;
+    }
+    if(!rt_entry->next){
+        rt_entry->prev->next = 0;
+        rt_entry->prev = 0;
+        return;
+    }
+
+    rt_entry->prev->next = rt_entry->next;
+    rt_entry->next->prev = rt_entry->prev;
+    rt_entry->prev = 0;
+    rt_entry->next = 0;
+}
+
+#define ITERTAE_RT_TABLE_BEGIN(rt_table_ptr, rt_entry_ptr)                \
+{                                                                         \
+    rt_entry_t *_next_rt_entry;                                           \
+    for((rt_entry_ptr) = (rt_table_ptr)->head;                            \
+            (rt_entry_ptr);                                               \
+            (rt_entry_ptr) = _next_rt_entry) {                            \
+        _next_rt_entry = (rt_entry_ptr)->next;
+
+#define ITERTAE_RT_TABLE_END(rt_table_ptr, rt_entry_ptr)  }}
+
+#endif /* __RT__ */

WheelTimer/Assignment/rt_entry_expiration.c

@@ -0,0 +1,79 @@
+/*
+ * =====================================================================================
+ *
+ *       Filename:  rt_entry_expiration.c
+ *
+ *    Description: This file illustrates how to age out rt table entry 
+ *
+ *        Version:  1.0
+ *        Created:  10/27/2020 04:59:45 AM
+ *       Revision:  none
+ *       Compiler:  gcc
+ *
+ *         Author:  ABHISHEK SAGAR (), sachinites@gmail.com
+ *   Organization:  Juniper Networks
+ *
+ * =====================================================================================
+ */
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <stdint.h>
+#include "rt.h"
+
+static rt_table_t rt;
+
+int
+main(int argc, char **argv){
+
+	rt_init_rt_table(&rt);
+
+	rt_add_new_rt_entry(&rt, "122.1.1.1", 32, "10.1.1.1", "eth0");
+    rt_add_new_rt_entry(&rt, "122.1.1.2", 32, "10.1.1.2", "eth1");
+    rt_add_new_rt_entry(&rt, "122.1.1.3", 32, "10.1.1.3", "eth2");
+    rt_add_new_rt_entry(&rt, "122.1.1.4", 32, "10.1.1.4", "eth3");
+    rt_add_new_rt_entry(&rt, "122.1.1.5", 32, "10.1.1.5", "eth4");
+
+	while(1){
+		printf("1. Add rt table entry\n");
+		printf("2. Update rt table entry\n");
+		printf("3. Delete rt table entry\n");
+		printf("4. Dump rt table\n");
+
+		int choice;
+		printf("Enter Choice :");
+		scanf("%d", &choice);
+		fflush(stdin);
+        switch(choice){
+            case 1:
+                {
+                    char dest[16];
+                    uint8_t mask;
+                    char oif[32];
+                    char gw[16];
+                    printf("Enter Destination :");
+                    scanf("%s", dest);
+                    printf("Mask : ");
+                    scanf("%hhd", &mask);
+                    printf("Enter oif name :");
+                    scanf("%s", oif);
+                    printf("Enter Gateway IP :");
+                    scanf("%s", gw);
+                    if(!rt_add_new_rt_entry(&rt, dest, mask,
+                        gw, oif)){
+                        printf("Error : Could not add an entry\n");
+                    }
+				}
+				break;
+			case 2:
+				break;
+			case 3:
+				break;
+			case 4:
+				rt_dump_rt_table(&rt);
+			default:
+				;
+		}
+	}
+	return 0;
+}