On Thu, Apr 25, 2024 at 5:13 AM Jason Xing <kerneljasonx...@gmail.com> wrote: > > From: Jason Xing <kernelx...@tencent.com> > > In production, there are so many cases about why the RST skb is sent but > we don't have a very convenient/fast method to detect the exact underlying > reasons. > > RST is implemented in two kinds: passive kind (like tcp_v4_send_reset()) > and active kind (like tcp_send_active_reset()). The former can be traced > carefully 1) in TCP, with the help of drop reasons, which is based on > Eric's idea[1], 2) in MPTCP, with the help of reset options defined in > RFC 8684. The latter is relatively independent, which should be > implemented on our own, such as active reset reasons which can not be > replace by skb drop reason or something like this. > > In this series, I focus on the fundamental implement mostly about how > the rstreason mechanism works and give the detailed passive part as an > example, not including the active reset part. In future, we can go > further and refine those NOT_SPECIFIED reasons. > > Here are some examples when tracing: > <idle>-0 [002] ..s1. 1830.262425: tcp_send_reset: skbaddr=x > skaddr=x src=x dest=x state=x reason=NOT_SPECIFIED > <idle>-0 [002] ..s1. 1830.262425: tcp_send_reset: skbaddr=x > skaddr=x src=x dest=x state=x reason=NO_SOCKET > > [1] > Link: > https://lore.kernel.org/all/CANn89iJw8x-LqgsWOeJQQvgVg6DnL5aBRLi10QN2WBdr+X4k=w...@mail.gmail.com/
Reviewed-by: Eric Dumazet <eduma...@google.com> Thanks !
