PWOSPF Project

.gitignore

@@ -0,0 +1,4 @@
+*~
+*.o
+sr
+*.d

Makefile

@@ -0,0 +1,79 @@
+#------------------------------------------------------------------------------
+# File: Makefile
+# 
+# Note: This Makefile requires GNU make.
+# 
+# (c) 2001,2000 Stanford University
+#
+#------------------------------------------------------------------------------
+
+all : sr
+
+CC = g++
+
+OSTYPE = $(shell uname)
+
+ifeq ($(OSTYPE),Linux)
+ARCH = -D_LINUX_
+SOCK = -lnsl
+endif
+
+ifeq ($(OSTYPE),SunOS)
+ARCH =  -D_SOLARIS_
+SOCK = -lnsl -lsocket
+endif
+
+ifeq ($(OSTYPE),Darwin)
+ARCH = -D_DARWIN_
+SOCK =
+endif
+
+ifdef NO_DEBUG
+  CFLAGS = -g -Wall -ansi $(ARCH)
+else
+  CFLAGS = -g -Wall -ansi -D_DEBUG_ $(ARCH)
+endif
+
+LIBS= $(SOCK) -lm -lresolv -lpthread
+PFLAGS= -follow-child-processes=yes -cache-dir=/tmp/${USER} 
+PURIFY= purify ${PFLAGS}
+
+sr_SRCS = sr_router.c sr_main.c  \
+          sr_if.c sr_rt.c sr_vns_comm.c   \
+          sr_dumper.c sr_pwospf.c sha1.c cache.c queue.c \
+          pwospf_neighbors.c pwospf_topology.c dijkstra_stack.c
+
+sr_OBJS = $(patsubst %.c,%.o,$(sr_SRCS))
+sr_DEPS = $(patsubst %.c,.%.d,$(sr_SRCS))
+
+$(sr_OBJS) : %.o : %.c
+	$(CC) -c $(CFLAGS) $< -o $@
+
+$(sr_DEPS) : .%.d : %.c
+	$(CC) -MM $(CFLAGS) $<  > $@
+
+include $(sr_DEPS)	
+
+sr : $(sr_OBJS)
+	$(CC) $(CFLAGS) -o sr $(sr_OBJS) $(LIBS) 
+
+sr.purify : $(sr_OBJS)
+	$(PURIFY) $(CC) $(CFLAGS) -o sr.purify $(sr_OBJS) $(LIBS)
+
+.PHONY : clean clean-deps dist    
+
+clean:
+	rm -f *.o *~ core sr *.dump *.tar tags
+
+clean-deps:
+	rm -f .*.d
+
+dist-clean: clean clean-deps
+	rm -f .*.swp pwospf_stub.tar.gz
+
+dist: dist-clean 
+	(cd ..; tar -X pwospf_stub/exclude -cvf pwospf_stub.tar pwospf_stub/; gzip pwospf_stub.tar); \
+    mv ../pwospf_stub.tar.gz .
+
+tags:
+	ctags *.c

README.md

@@ -1,4 +1,35 @@
+PWOSPF (Pee-Wee OSPF)
+=====================
+
+This project involves building advanced functionality on top of the <a href="https://github.com/cesarghali/SimpleRouter" target="_new">SimpleRouter</a> project. The goal is to develop a simple dynamic routing protocol, PWOSPF, so that your router can generate its forwarding table automatically based on routes advertised by other routers on the network. By the end of this project, your router is expected to be able to build its forwarding table from link-state advertisements sent from other routers, and route traffic through complex topologies containing multiple nodes.
+
 PWOSPF
-======
+------
+The routing protocol you will be implementing is a link state protocol that is loosely based on OSPFv2. You may find a full specification of PWOSPF <a href="" target="_new">here</a>. Note that while PWOSPF is based on OSPFv2 it is sufficiently different that referring to the OSPFv2 as a reference will not be of much help and contrarily may confuse or mislead you.
+
+Network Topology
+----------------
+![Network Topology]()
+
+The task is to implement PWOSPF within your existing router so that your router will be able to do the following:
+
+* build the correct forwarding tables on the assignment topology.
+* detect when routers join/or leave the topology and correct the forwarding tables correctly.
+* inter-operate with a third party reference solution that implements pwosp.
+
+Running Multiple Routers
+------------------------
+Since this project requires multiple instances of your router to run simultaneously you will want to use the -r and the -v command line options. -r allows you to specify the routing table file you want to use (e.g. -r rtable.vhost1) and -v allows you to specify the host you want to connect to on the topology (e.g. -v vhost3). Connecting to vhost3 on topology 300 should look something like:
+
+> ./sr -t 300 -v vhost3 -r rtable.vhost3
+
+For more information check Stanford <a href="http://yuba.stanford.edu/vns/assignments/pwospf/" target="_new">Virtual Network System</a>.
+
+Partners
+--------
+Wassim Itani
+Ahmad El Hajj
 
-This project implements a simple version of the OSPF routing protocol.
+References
+----------
+Ayman Kayssi, American University of Beirut, <a href="http://staff.aub.edu.lb/~ayman/" target="_new">More</a>.

cache.c

@@ -0,0 +1,106 @@
+#include <stdio.h>
+#include <time.h>
+
+#include "cache.h"
+
+
+void cache_push(struct cache_item* pFirstItem, struct cache_item* pNewItem)
+{
+    if (pFirstItem->next_item != NULL)
+    {
+        pNewItem->next_item = pFirstItem->next_item;
+        pFirstItem->next_item = pNewItem;
+    }
+
+    pFirstItem->next_item = pNewItem;
+}
+
+struct cache_item* cache_pop(struct cache_item* pFirstItem)
+{
+    if (pFirstItem->next_item == NULL)
+    {
+        return NULL;
+    }
+    else
+    {
+        struct cache_item* pResult = pFirstItem->next_item;
+
+        pFirstItem->next_item = pFirstItem->next_item->next_item;
+
+        return pResult;
+    }
+}
+
+struct cache_item* cache_search(struct cache_item* pFirstItem, uint32_t IP)
+{
+    struct cache_item* ptr = pFirstItem->next_item;
+
+    while(ptr != NULL)
+    {
+        if (ptr->ip == IP)
+        {
+            return ptr;
+        }
+        ptr = ptr->next_item;
+    }
+
+    return NULL;
+}
+
+struct cache_item* cache_create_item(uint32_t ip, unsigned char mac[ETHER_ADDR_LEN], int time_stamp)
+{
+    struct cache_item* cache_new_item = ((cache_item*)(malloc(sizeof(cache_item))));
+    cache_new_item->ip = ip;
+    for (int i = 0; i < ETHER_ADDR_LEN; i++)
+    {
+        cache_new_item->mac[i] = mac[i];
+    }
+    cache_new_item->time_stamp = time_stamp;
+    cache_new_item->next_item = NULL;
+    return cache_new_item;
+}
+
+void check_cache(struct cache_item* pFirstItem)
+{
+    time_t time_stamp;
+    time(&time_stamp);
+    int current_time_stamp = ((int)(time_stamp));
+
+    struct cache_item* ptr = pFirstItem;
+
+    while(ptr != NULL)
+    {
+        if (ptr->next_item == NULL)
+        {
+            break;
+        }
+
+        if (current_time_stamp - ptr->next_item->time_stamp >= 15)
+        {
+            in_addr ip_addr;
+            ip_addr.s_addr = ptr->next_item->ip;
+            Debug("\n\n**** Removing cache entry, [%s, ", inet_ntoa(ip_addr));
+            DebugMAC(ptr->next_item->mac);
+            Debug("] *****\n\n");
+
+            remove_cache_item(ptr);
+
+        }
+
+        ptr = ptr->next_item;
+    }
+}
+
+void remove_cache_item(struct cache_item* previous_item)
+{
+    if (previous_item->next_item->next_item != NULL)
+    {
+        previous_item->next_item = previous_item->next_item->next_item;
+    }
+    else
+    {
+        previous_item->next_item = NULL;
+    }
+
+    free(previous_item->next_item);
+}

cache.h

@@ -0,0 +1,24 @@
+#ifndef CACHE_H
+#define CACHE_H
+
+#include <stdlib.h>
+
+#include "sr_if.h"
+#include "sr_router.h"
+
+#include "sr_protocol.h"
+
+struct cache_item
+{
+    uint32_t ip;
+    unsigned char mac[ETHER_ADDR_LEN];
+    int time_stamp;
+    struct cache_item* next_item;
+} __attribute__ ((packed)) ;
+
+void cache_push(struct cache_item*, struct cache_item*);
+struct cache_item* cache_pop(struct cache_item*);
+struct cache_item* cache_search(struct cache_item*, uint32_t);struct cache_item* cache_create_item(uint32_t ip, unsigned char mac[ETHER_ADDR_LEN], int time_stamp);
+void check_cache(struct cache_item*);
+void remove_cache_item(struct cache_item*);
+#endif	//CACHE_H

dijkstra_stack.c

@@ -0,0 +1,65 @@
+#include <stdio.h>
+#include <time.h>
+
+#include "dijkstra_stack.h"
+
+
+void dijkstra_stack_push(struct dijkstra_item* dijkstra_first_item, struct dijkstra_item* dijkstra_new_item)
+{
+    if (dijkstra_first_item->next != NULL)
+    {
+        dijkstra_new_item->next = dijkstra_first_item->next;
+        dijkstra_first_item->next = dijkstra_new_item;
+    }
+
+    dijkstra_first_item->next = dijkstra_new_item;
+}
+
+void dijkstra_stack_reorder(struct dijkstra_item* dijkstra_first_item)
+{
+    struct dijkstra_item* ptr = dijkstra_first_item;
+    while (ptr->next != NULL)
+    {
+        if (ptr->next->next == NULL)
+        {
+            break;
+        }
+
+        if (ptr->next->cost > ptr->next->next->cost)
+        {
+            struct dijkstra_item* temp_1 = ptr->next->next->next;
+            struct dijkstra_item* temp_2 = ptr->next->next;
+            ptr->next->next->next = ptr->next;
+            ptr->next->next = temp_1;
+            ptr->next = temp_2;
+        }
+
+        ptr = ptr->next;
+    }
+}
+
+struct dijkstra_item* dijkstra_stack_pop(struct dijkstra_item* dijkstra_first_item)
+{
+    if (dijkstra_first_item->next == NULL)
+    {
+        return NULL;
+    }
+    else
+    {
+        struct dijkstra_item* pResult = dijkstra_first_item->next;
+
+        dijkstra_first_item->next = dijkstra_first_item->next->next;
+
+        return pResult;
+    }
+}
+
+struct dijkstra_item* create_dikjstra_item(struct ospfv2_topology_entry* new_topology_entry, uint8_t cost)
+{
+    struct dijkstra_item* dijkstra_new_item = ((dijkstra_item*)(malloc(sizeof(dijkstra_item))));
+    dijkstra_new_item->topology_entry = new_topology_entry;
+    dijkstra_new_item->cost = cost;
+    dijkstra_new_item->parent = NULL;
+    dijkstra_new_item->next = NULL;
+    return dijkstra_new_item;
+}

dijkstra_stack.h

@@ -0,0 +1,23 @@
+#ifndef DIJKSTRA_STACK_H
+#define DIJKSTRA_STACK_H
+
+#include <stdlib.h>
+
+#include "sr_if.h"
+#include "sr_router.h"
+
+#include "sr_protocol.h"
+
+struct dijkstra_item
+{
+    struct ospfv2_topology_entry* topology_entry;
+    uint8_t cost;
+    struct dijkstra_item* parent;
+    struct dijkstra_item* next;
+} __attribute__ ((packed)) ;
+
+void dijkstra_stack_push(struct dijkstra_item*, struct dijkstra_item*);
+void dijkstra_stack_reorder(struct dijkstra_item*);
+struct dijkstra_item* dijkstra_stack_pop(struct dijkstra_item*);
+struct dijkstra_item* create_dikjstra_item(struct ospfv2_topology_entry*, uint8_t);
+#endif	//DIJKSTRA_STACK_H