Floodlight 启动过程分析

时间:2022-11-11 22:52:52
Floodlight 启动过程分析
 Floodlight 启动过程分析
1. 在Main中先是载入模块,启动REST服务,而后构建一个实现了IFloodlightProviderService接口的实例(即Controller)并执行;
2. 接下来进入Controller的run()方法,此时全部的环境初始化工作已经完毕。构建一个基于netty的TCP server,最重要的是流水线factory OpenflowPipelineFactory 的设置,里面是controller上流,下流处理的handler(详细细节见===)。

当Channel建立,接收到来自OF SW的消息之后就会调用 messageReceived() 方法;依据不同的of msg类型,分发给
processOFMessage 进行详细处理;此外。假设这个消息须要进行对SW的回复,或者有其它监听者感兴趣,就呼叫 handleMessage 进行额外的处理,代码贴出来。

  protected void handleMessage(IOFSwitch sw, OFMessage m, FloodlightContext bContext){

        Ethernet eth = null;

        switch (m.getType()) {

            case PACKET_IN:

                OFPacketIn pi = (OFPacketIn)m;

                //  默认情况下总是true

                if (Controller.ALWAYS_DECODE_ETH) {

                    eth = new Ethernet();
                    //解析packet_in消息到eth中,所以以下的bcStore能够直接存储

                    eth.deserialize(pi.getPacketData(), 0, pi.getPacketData().length);

                    counterStore.updatePacketInCounters(sw, m, eth);

                }

                // fall through to default case...



            default:

               

                List<IOFMessageListener> listeners = null;

                if (messageListeners.containsKey(m.getType())) {

                    listeners = messageListeners.get(m.getType()).getOrderedListeners();

                }

                       

                FloodlightContext bc = null;

                if (listeners != null) {

                    // Check if floodlight context is passed from the calling

                    // function, if so use that floodlight context, otherwise

                    // allocate one

                    if (bContext == null) {

                        bc = flcontext_alloc();

                    } else {

                        bc = bContext;

                    }

                    if (eth != null) { 

                        IFloodlightProviderService.bcStore.put(bc,IFloodlightProviderService.CONTEXT_PI_PAYLOAD, eth);
                       
 //缓存到hashmap中。所以当我们加入自己的模块来监听packetin消息的时候。能够从中取出。做自己的业务处理。

                    }

                          

                    Command cmd;

                    for (IOFMessageListener listener : listeners) {

                        if (listener instanceof IOFSwitchFilter) {

                            if (!((IOFSwitchFilter)listener).isInterested(sw)) {

                                continue;

                            }

                        }

                         // 遍历全部对packetin感兴趣的listener。分别运行他们的receive方法;

                        cmd = listener.receive(sw, m, bc);

 

                        if (Command.STOP.equals(cmd)) {

                            break;

                        }     }    }

                      

                if ((bContext == null) && (bc != null)) flcontext_free(bc);

        }    }

3. 在循环中随时处理SW的更新消息。


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