Bpf和xdp代码的编译和加载和redhat的xdp Filter防火墙过滤
需要用clang把c语言写的代码编译成ebpf的object文件，然后用工具把object文件加载到内核。 不过也有纯golang的库用于编译和调试ebpf的 https://github.com/cilium/ebpf
也有很多辅助工具用于加载bpf代码，比如https://github.com/iovisor/bcc 用于调试分析系统，已经集成了很多脚本了吧，好像可以取代systemtap.
BPF and XDP Reference Guide
https://docs.cilium.io/en/stable/bpf/
详细介绍了llvm编译bpf和ip 命令加载等用法, 内核提供 bpftool 命令用于辅助调试bpf代码
bpf相关的资讯博客
https://ebpf.io/
Load XDP programs using the ip (iproute2) command
https://fntlnz.wtf/post/xdp-ip-iproute/
ip link的帮助手册 详细介绍了怎么用ip命令加载xdp代码
https://www.man7.org/linux/man-pages/man8/ip-link.8.html
WRITING AN XDP NETWORK FILTER WITH EBPF
https://duo.com/labs/tech-notes/writing-an-xdp-network-filter-with-ebpf
简单的防火墙过滤ip黑名单的例子
https://github.com/gamemann/XDP-Firewall
https://github.com/cppcoffee/ipblock
https://github.com/massoudasadi/packiffer/blob/master/xdp_block_address.c
Linux下一代防火墙bpfilter是什么？让我演示给你看
https://blog.csdn.net/dog250/article/details/103283981
csdn博主演示用xdp和实现类似bpfilter的ip黑名单功能
redhat提供一个xdp-tools 工具包，有提供一个xdp-filter命令用户做xdp防火墙过滤。
https://access.redhat.com/documentation/en-us/red_hat_enterprise_linux/8/html/configuring_and_managing_networking/using-xdp-filter-for-high-performance-traffic-filtering-to-prevent-ddos-attacks_configuring-and-managing-networking
https://www.redhat.com/en/blog/capturing-network-traffic-express-data-path-xdp-environment
redhat的xdp编程教程 https://developers.redhat.com/blog/2018/12/06/achieving-high-performance-low-latency-networking-with-xdp-part-1#some_rough_edges https://developers.redhat.com/blog/2018/12/17/using-xdp-maps-rhel8#some_map_caveats https://github.com/pabeni/xdp_walkthrough_examples
之前记录的相关资料，bpf的防火墙应用:
BPF comes to firewalls
https://lwn.net/Articles/747551/
内核支持自动把iptables规则转换为bpf过滤代码，源码是在这 https://elixir.bootlin.com/linux/latest/source/net/bpfilter
eBPF / XDP firewall and packet filtering
http://vger.kernel.org/lpc_net2018_talks/ebpf-firewall-LPC.pdf
L4Drop: XDP DDoS Mitigations
https://blog.cloudflare.com/l4drop-xdp-ebpf-based-ddos-mitigations/
介绍自动发现ddos和bpf规则的生成
https://github.com/gmd20/gmd20.github.io/blob/master/_posts/2019-05-01-XDP%E5%92%8CAF_XDP%E5%92%8Cbpfilter.markdown