Re: [PATCH net-next v6 01/11] tcp: add a dropreason definitions and prepare for cookie check

[Kuniyuki Iwashima <kuniyu@amazon.com>]

From: Jason Xing <kerneljasonxing@gmail.com>
Date: Mon, 19 Feb 2024 11:28:28 +0800
> From: Jason Xing <kernelxing@tencent.com>
> 
> Only add one drop reason to detect the condition of skb dropped
> because of hook points in cookie check for later use.
> 
> Signed-off-by: Jason Xing <kernelxing@tencent.com>
> --
> v6
> Link: https://lore.kernel.org/netdev/20240215210922.19969-1-kuniyu@amazon.com/
> 1. Modify the description NO_SOCKET to extend other two kinds of invalid
> socket cases.
> What I think about it is we can use it as a general indicator for three kinds of
> sockets which are invalid/NULL, like what we did to TCP_FLAGS.
> Any better ideas/suggestions are welcome :)
> 
> v5
> Link: https://lore.kernel.org/netdev/CANn89i+iELpsoea6+C-08m6+=JkneEEM=nAj-28eNtcOCkwQjw@mail.gmail.com/
> Link: https://lore.kernel.org/netdev/632c6fd4-e060-4b8e-a80e-5d545a6c6b6c@kernel.org/
> 1. Use SKB_DROP_REASON_IP_OUTNOROUTES instead of introducing a new one (Eric, David)
> 2. Reuse SKB_DROP_REASON_NOMEM to handle failure of request socket allocation (Eric)
> 3. Reuse NO_SOCKET instead of introducing COOKIE_NOCHILD
> 4. Reuse IP_OUTNOROUTES instead of INVALID_DST (Eric)
> 5. adjust the title and description.
> 
> v4
> Link: https://lore.kernel.org/netdev/20240212172302.3f95e454@kernel.org/
> 1. fix misspelled name in kdoc as Jakub said
> ---
>  include/net/dropreason-core.h | 11 ++++++++++-
>  1 file changed, 10 insertions(+), 1 deletion(-)
> 
> diff --git a/include/net/dropreason-core.h b/include/net/dropreason-core.h
> index 6d3a20163260..3c867384dead 100644
> --- a/include/net/dropreason-core.h
> +++ b/include/net/dropreason-core.h
> @@ -54,6 +54,7 @@
>  	FN(NEIGH_QUEUEFULL)		\
>  	FN(NEIGH_DEAD)			\
>  	FN(TC_EGRESS)			\
> +	FN(SECURITY_HOOK)		\
>  	FN(QDISC_DROP)			\
>  	FN(CPU_BACKLOG)			\
>  	FN(XDP)				\
> @@ -105,7 +106,13 @@ enum skb_drop_reason {
>  	SKB_CONSUMED,
>  	/** @SKB_DROP_REASON_NOT_SPECIFIED: drop reason is not specified */
>  	SKB_DROP_REASON_NOT_SPECIFIED,
> -	/** @SKB_DROP_REASON_NO_SOCKET: socket not found */
> +	/**
> +	 * @SKB_DROP_REASON_NO_SOCKET: no invalid socket that can be used.

s/invalid/valid/

Same for 2) and 3) below.


> +	 * Reason could be one of three cases:
> +	 * 1) no established/listening socket found during lookup process
> +	 * 2) no invalid request socket during 3WHS process
> +	 * 3) no invalid child socket during 3WHS process
> +	 */
>  	SKB_DROP_REASON_NO_SOCKET,
>  	/** @SKB_DROP_REASON_PKT_TOO_SMALL: packet size is too small */
>  	SKB_DROP_REASON_PKT_TOO_SMALL,