Re: [PATCH net-next v3 3/3] net: icmp: add reasons of the skb drops to icmp protocol

[Menglong Dong]

On Sat, Mar 19, 2022 at 6:33 AM David Ahern <dsahern@xxxxxxxxxx> wrote:
>
> On 3/18/22 1:26 AM, Menglong Dong wrote:
> > Yeah, PTYPE seems not suitable. I mean that replace SKB_DROP_REASON_PTYPE_ABSENT
> > that is used in __netif_receive_skb_core() with L3_PROTO, which means no L3
> > protocol handler (or other device handler) is not found for the
> > packet. This seems more
> > friendly and not code based.
> >
> >>> And use SKB_DROP_REASON_L4_PROTO for the L4 protocol problem,
> >>> such as GRE version not supported, ICMP type not supported, etc.
> > Is this L4_PROTO followed by anyone?
>
> how about just a generic
>         SKB_DROP_REASON_UNHANDLED_PROTO  /* protocol not implemented
>                                           * or not supported
>                                           */
>
> in place of current PTYPE_ABSENT (so a rename to remove a Linux code
> reference), and then use it for no L3 protocol handler, no L4 protocol
> handler, version extensions etc. The instruction pointer to symbol gives
> the context of the unsupported protocol.

Yeah, I think it's a good idea :)

Thanks!
Menglong Dong