该程序是POX WIKI上的程序,我只是将统计的报文修改了以下,并做了对这个程序运行流程的分析:
1.程序从launch开始运行
2.监听2个事件,如果监听到“FlowStatsReceived”就交由_handle_flowstats_received()来处理,另一个事件同样道理
3.每5s执行以下_time_func(),这是一步实时监视的处理
4._time_func()启动后发送2个状态请求给所有的switch
5.如果监听到上面说的两个事件,就执行相应的handle部分,其中_handle_flowstats_received()部分会统计源IP为“10.0.0.1”的报文字节数,报文数和报文流数量,并将结果输出出来,可以在terminal上看到
ps: of_json的作用是将openflow的数据结构转化为json的友好数据结构
运行方法可以是:
terminal 1: sudo python topo1.py ---运行一个任意topo
terminal 2: ./pox.py forwarding.l2_learning flow.stats2 ---运行pox主程序,2层交换程序和流量监控程序
代码如下:
#!/usr/bin/python # Copyright 2012 William Yu # wyu@ateneo.edu # # This file is part of POX. # # POX 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, either version 3 of the License, or # (at your option) any later version. # # POX 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. # # You should have received a copy of the GNU General Public License # along with POX. If not, see <http://www.gnu.org/licenses/>. # """ This is a demonstration file created to show how to obtain flow and port statistics from OpenFlow 1.0-enabled switches. The flow statistics handler contains a summary of web-only traffic. """ # standard includes from pox.core import core from pox.lib.util import dpidToStr import pox.openflow.libopenflow_01 as of # include as part of the betta branch from pox.openflow.of_json import * log = core.getLogger() # handler for timer function that sends the requests to all the # switches connected to the controller. def _timer_func (): for connection in core.openflow._connections.values(): connection.send(of.ofp_stats_request(body=of.ofp_flow_stats_request())) connection.send(of.ofp_stats_request(body=of.ofp_port_stats_request())) log.debug("Sent %i flow/port stats request(s)", len(core.openflow._connections)) # handler to display flow statistics received in JSON format # structure of event.stats is defined by ofp_flow_stats() def _handle_flowstats_received (event): stats = flow_stats_to_list(event.stats) # wsc:this step is just for debugging, so it can ba deleted. log.debug("FlowStatsReceived from %s: %s", dpidToStr(event.connection.dpid), stats) # Get number of bytes/packets in flows for web traffic only web_bytes = 0 web_flows = 0 web_packet = 0 for f in event.stats: if f.match.nw_src == IPAddr("10.0.0.1"): web_bytes += f.byte_count web_packet += f.packet_count web_flows += 1 log.info("Web traffic from %s: %s bytes (%s packets) over %s flows", dpidToStr(event.connection.dpid), web_bytes, web_packet, web_flows) # handler to display port statistics received in JSON format def _handle_portstats_received (event): stats = flow_stats_to_list(event.stats) log.debug("PortStatsReceived from %s: %s", dpidToStr(event.connection.dpid), stats) # main functiont to launch the module def launch (): from pox.lib.recoco import Timer # attach handsers to listners core.openflow.addListenerByName("FlowStatsReceived", _handle_flowstats_received) core.openflow.addListenerByName("PortStatsReceived", _handle_portstats_received) # timer set to execute every five seconds Timer(5, _timer_func, recurring=True)