Re: [PATCH net-next v3 4/4] net: tun: track dropped skb via kfree_skb_reason()

[David Ahern <dsahern@gmail.com>]

On 2/24/22 10:57 PM, Menglong Dong wrote:
>>>
>>> For tun unique filters, how about using a shortened version of the ioctl
>>> name used to set the filter.
>>>
>>
>> Although TUN is widely used in virtualization environment, it is only one of
>> many drivers. I prefer to not introduce a reason that can be used only by a
>> specific driver.
>>
>> In order to make it more generic and more re-usable (e.g., perhaps people may
>> add ebpf filter to TAP driver as well), how about we create below reasons.
>>
>> SKB_DROP_REASON_DEV_FILTER,     /* dropped by filter attached to
>> 				 * or directly implemented by a
>> 				 * specific driver
>> 				 */
>> SKB_DROP_REASON_BPF_DEV,	/* dropped by bpf directly
>> 				 * attached to a specific device,
>> 				 * e.g., via TUNSETFILTEREBPF
>> 				 */
> 
> Aren't DEV_FILTER and BPF_DEV too generic? eBPF atached to netdev can
> be many kinds, such as XDP, TC, etc.

yes.

> 
> I think that use TAP_TXFILTER instaed of DEV_FILTER maybe better?
> and TAP_FILTER->BPF_DEV. Make them similar to the name in
> __tun_chr_ioctl() may be easier for user to understand.
> 

in this case given the unique attach points and API tap in the name
seems more appropriate