Re: eBPF sockhash datastructure and stream_parser/stream_verdict programs

[Cong Wang <xiyou.wangcong@gmail.com>]

Hi, His

On Mon, Jan 03, 2022 at 03:53:12PM +0300, His Shadow wrote:
> Greeetings. Here's the problem. I've written a simple program, that,
> when a connection is established, it establishes a connection to a
> predetermined target and starts routing traffic between a user
> connection and a new connection.
> I've tried to use ebpf stream_parser/verdict programs for this,
> however there's a problem: when a connection to my program is
> established, client sends the data immediately, however there's a
> delay, while I establish a connection to the target. So stream_verdict
> never gets called, because the data is already in the socket receive
> queue(or maybe I'm misunderstanding something). Is there a way around
> this? Should I use something else, like skb_msg verdict?

Are you saying the packets arrived before you put the socket
into the sockmap? If so, you can consider
BPF_SOCK_OPS_PASSIVE_ESTABLISHED_CB.

Hope this helps.

Thanks.