import sys from colorama import Fore, Style from mininet.net import Mininet from mininet.link import TCLink from mininet.topo import Topo from mininet.node import Node from mininet.cli import CLI from mininet.log import setLogLevel class MyRouter (Node): def config(self, **params): super(MyRouter, self).config(**params) self.cmd('sysctl net.ipv4.ip_forward=1') #Enable forwarding on the router def terminate(self): self.cmd('sysctl net.ipv4.ip_forward=0') #Disable forwarding on the router super(MyRouter, self).terminate def build_topology(config_file): topo = Topo() elements = {} # Dictionary to store nodes with open(config_file, 'r') as file: for line in file: line = line.strip() if line.startswith('#'): #Skip comment continue parts = line.split(" ") #Parse the topology file using spaces if parts[0] == 'N_host': #Parse hosts host_name = parts[1] elements[host_name] = topo.addHost(host_name) elif parts[0] == 'N_router': #Parse routers router_name = parts[1] elements[router_name] = topo.addNode(router_name) elif parts[0] == 'N_switch': #Parse switches switch_name = parts[1] elements[switch_name] = topo.addSwitch(switch_name) elif parts[0] == 'NN_link': #Parse general links nodes to nodes node1 = parts[1] node2 = parts[2] topo.addLink(elements.get(node1), elements.get(node2)) elif parts[0] == 'SN_link': #Parse general links switches to nodes switch = parts[1] node = parts[2] bandwidth = int(parts[3]) topo.addLink(elements.get(switch), elements.get(node), bw=bandwidth) if parts[0] == 'host': #Parse hosts host_name = parts[1] host_ip = parts[2] host_nexthop = 'via ' + parts[3] elements[host_name] = topo.addHost(host_name, ip=host_ip, defaultRoute=host_nexthop) elif parts[0] == 'router': #Parse routers router_name = parts[1] router_ip = parts[2] elements[router_name] = topo.addNode(router_name, cls=MyRouter, ip=router_ip) elif parts[0] == 'linkRR': #Parse links routers to routers router1 = parts[1] router1_intfName = parts[2] router1_intfIP = parts[3] router2 = parts[4] router2_intfName = parts[5] router2_intfIP = parts[6] topo.addLink(elements.get(router1), elements.get(router2), intfName1=router1_intfName, intfName2=router2_intfName, params1={'ip' : router1_intfIP}, params2={'ip' : router2_intfIP}) elif parts[0] == 'linkRH': #Parse links routers to hosts host = parts[1] host_intfName = parts[2] router = parts[3] router_intfName = parts[4] router_intfIP = parts[5] topo.addLink(elements.get(host), elements.get(router), intfName1=host_intfName, intfName2=router_intfName, params2={'ip' : router_intfIP}) elif parts[0] == 'linkRS': #Parse links routers to switches switch = parts[1] router = parts[2] router_intfName = parts[3] router_intfIP = parts[4] topo.addLink(elements.get(switch), elements.get(router), intfName2=router_intfName, params2={'ip' : router_intfIP}) elif parts[0] == 'linkSS': #Parse links switches to switches switch1 = parts[1] switch2 = parts[2] topo.addLink(elements.get(switch1), elements.get(switch2)) elif parts[0] == 'linkSH': #Parse links switches to hosts switch = parts[1] host = parts[2] host_intfName = parts[3] topo.addLink(elements.get(switch), elements.get(host), intfName2=host_intfName) return topo def run_topology(config_file): setLogLevel('info') #Different logging levels are 'info' 'warning' 'error' 'debug' topo = build_topology(config_file) net = Mininet(topo=topo, link=TCLink) net.start() #Starting the network with open(config_file, 'r') as file: #Search in the configuration file for routing table for line in file: line = line.strip() if line.startswith('#'): #Skip comment continue parts = line.split(" ") if parts[0] == 'N_route': #Parse routing tables name = parts[1] pck_src = parts[2] pck_nexthop = parts[3] # cmd = 'ip route add ' + pck_src + ' via ' + pck_nexthop TODO # (net.getNodeByName(name)).cmd(cmd) elif parts[0] == 'route': #Parse routing tables name = parts[1] pck_src = parts[2] pck_nexthop = parts[3] interf = parts[4] cmd = 'ip route add ' + pck_src + ' via ' + pck_nexthop + ' dev ' + interf (net.getNodeByName(name)).cmd(cmd) if net.pingAll(): print(Fore.RED + "Network has issues" + Style.RESET_ALL) else: print(Fore.GREEN + "Network working properly" + Style.RESET_ALL) CLI(net) net.stop() #Stopping the network if __name__ == '__main__': if '-f' in sys.argv: try: file_index = sys.argv.index('-f') + 1 config_file = sys.argv[file_index] run_topology(config_file) except IndexError: print("Error: No configuration file provided after -f flag.") else: run_topology('MininetTopo.conf')