Hi, everyone I am now reading the source code of netfilter. When it comes to iptable, I am confused by the ipt_table_info's underflow data member. It seems that iptable provide a method to jump from one rule to another, and jump back to the original one, just like a stack. While the underflow is always the last one, or the buttom of the stack. Some one told me that underflow marks the last of the rules of the corresponding hook, I think it can do more. for example, cleanning up. But what is this member's supposed use? Thank you.
