环境p4_environmen文件夹中还缺少了bmv2交换机（behavioral-model）和p4c-bm编译器，请自行下载，别忘了修改env.sh 有问题欢迎邮件2210274022@email.szu.edu.cn讨论

Test

The method to start the p4 switch is to set up a topology on mininet where we run the switch.

1. Open a terminal and enter the directory hash_version
2. Run run_demo.sh in terminal to start the switch (the data plane of NetHCF) on the topology defined in topo.py，顺利的话你会进入mininet
3. mininet基本的使用在'/home/myp4/P4/tutorials/exercises'，相信你已经看过这些练习了，更多的使用可以参考官方文档 according to mininet walkthrough. 这里我们xterm h1 h2 来打开客户机终端
4. Run controller.py 来统计不正常包数，控制NetHCF的过滤和学习状态。状态转换阈值可以设置
5. 你可以在cmd中直接输入/home/myp4/Downloads/Anti-spoof/p4_environment/behavioral-model/targets/simple_switch/sswitch_CLI hop_count.json 22223来运行CLI，他有很多指令，比如register_read 、register_read ，在control.py文件中使用了这些指令。
6. Then, just try!

Source Code

hop_count.p4 This is the p4 source code.

includes/headers.p4 This is the p4 code which defines the header used in NetHCF.

includes/parser.p4 This is the p4 code which defines the parser graph of NetHCF.

topo.py This script will set up the topology of this model and starts the CLI of p4 switch.

run_demo.sh Start the data plane on the topology defined in topo.py without log.

commands.txt There are table entries here, which will be loaded into the swtich by topo.py. You can also add the entries manually through CLI.

env.sh Set p4 related environment variables.

cleanup.sh Clean up the environment such as the pcap file and accessed webpage.

controller.py NetHCF's conrol plane program running on CPU, masters the running state of switch and matains a global view.

controller_update.py 双倍寄存器表示时间更新,每过一段时间要用缓存表覆盖原表，但是这里并没有实现，2^23太大了，跑起来很慢，我就写了一个记录动过数据的，然后把动过的地方给覆盖过去，但是没动的地方用0覆盖我没有办法实现。这个终归是要结合硬件来实现的。

send和receive都做了监听和发送，在xterm中运行，receive是接收端，send是发送端。写的比较冗余，不过也挺易懂的，可根据测试需要更改

hop_count.json P4编译后的产物，判断自己修改的P4代码有没有错，其实可以看这个json文件有没有更新内容，编译错误他是不会更新的。当然终端在一开始也会有报错。