Goals: Add links that are reasonable and good explanations of how stuff works. No hype and no vendor content if possible. Practical first-hand accounts of models in prod eagerly sought.

For a brief user-level introduction to CMake, watch C++ Weekly, Episode 78, Intro to CMake by Jason Turner. LLVM’s CMake Primer provides a good high-level introduction to the CMake syntax. Go read it now.
After that, watch Mathieu Ropert’s CppCon 2017 talk Using Modern CMake Patterns to Enforce a Good Modular Design (slides). It provides a thorough explanation of what modern CMake is and why it is so much better than “old school” CMake. The modular design ideas in this talk are based on the book [Large-Scale C++ Software Design](https://www.amazon.de/Large-Scale-Soft
[Unit] | |
Description=Jenkins Slave | |
Wants=network.target | |
After=network.target | |
[Service] | |
ExecStart=/usr/bin/java -Xms512m -Xmx512m -jar /opt/jenkins/slave.jar -jnlpUrl http://${JENKINS_SERVER}/slave-agent.jnlp -secret ${SECRET} | |
User=jenkins | |
Restart=always | |
RestartSec=10 |
由于路由管控系统的建立,实时动态黑洞路由已成为最有效的封锁手段,TCP连接重置和DNS污染成为次要手段,利用漏洞的穿墙方法已不再具有普遍意义。对此应对方法是多样化协议的VPN来抵抗识别。这里介绍一种太简单、有时很朴素的“穷人VPN”。
朴素VPN只需要一次内核配置(Linux内核),即可永久稳定运行,不需要任何用户态守护进程。所有流量转换和加密全部由内核完成,原生性能,开销几乎没有。静态配置,避免动态握手和参数协商产生指纹特征导致被识别。并且支持NAT,移动的内网用户可以使用此方法。支持广泛,基于L2TPv3标准,Linux内核3.2+都有支持,其他操作系统原则上也能支持。但有两个局限:需要root权限;一个隧道只支持一个用户。
朴素VPN利用UDP封装的静态L2TP隧道实现VPN,内核XFRM实现静态IPsec。实际上IP-in-IP隧道即可实现VPN,但是这种协议无法穿越NAT,因此必须利用UDP封装。内核3.18将支持Foo-over-UDP,在UDP里面直接封装IP,与静态的L2TP-over-UDP很类似。
import Data.Tree | |
import Data.List | |
import Debug.Trace | |
import Maybe | |
--the last int is the amount of argument | |
data Label = Command String | |
| Constant String | |
| Declaration | |
deriving Show |