nettrace is is a powerful tool to trace network packet and diagnose
network problem inside kernel on TencentOS.
It make use of eBPF.
'skb' is the struct that used in kernel to store network package.
By tracing kernel function and tracepoint (with the help of kprobe
based on eBPF) that handle skb, nettrace is able to show the path
of skb bypass inside kernel network stack. Therefor, some network
issue (such as package drop) can be solved simply.
