Re: [PATCH net-next 1/6] flow_offload: add flow_rule_no_unsupp_control_flags()

["Asbjørn Sloth Tønnesen" <ast@fiberby.net>]

Hi Baowen,

On 4/9/24 1:56 AM, Baowen Zheng wrote:
> On April 8, 2024 9:09 PM,  Asbjørn wrote:
> 
>> This helper can be used by drivers to check for the presence of unsupported
>> control flags.
>>
>> It mirrors the existing check done in sfc:
>>   drivers/net/ethernet/sfc/tc.c +276
>>
>> This is aimed at drivers, which implements some control flags.
>>
>> This should also be used by drivers that implement all current flags, so that
>> future flags will be unsupported by default.
>>
>> Only compile-tested.
>>
>> Signed-off-by: Asbjørn Sloth Tønnesen <ast@fiberby.net>
>> ---
>> include/net/flow_offload.h | 22 ++++++++++++++++++++++
>> 1 file changed, 22 insertions(+)
>>
>> diff --git a/include/net/flow_offload.h b/include/net/flow_offload.h index
>> 314087a5e1818..c1317b14da08c 100644
>> --- a/include/net/flow_offload.h
>> +++ b/include/net/flow_offload.h
>> @@ -449,6 +449,28 @@ static inline bool flow_rule_match_key(const struct
>> flow_rule *rule,
>>         return dissector_uses_key(rule->match.dissector, key);  }
>>
>> +/**
>> + * flow_rule_no_unsupp_control_flags() - check for unsupported control
>> +flags
>> + * @supp_flags: flags supported by driver
>> + * @flags: flags present in rule
>> + * @extack: The netlink extended ACK for reporting errors.
>> + *
>> + * Returns true if only supported control flags are set, false otherwise.
>> + */
>> +static inline bool flow_rule_no_unsupp_control_flags(const u32 supp_flags,
>> +                                                    const u32 flags,
>> +
> Hi Asbjørn, thanks for your work, it makes sense for driver check. Will it better to name flags as "ctrl_flags" to make it more clear since it indicates the ctrl_flags in rule and you name it as control.flags in the following print message.

Good point, I will rename that argument in v2.

I copied the error message verbatim from sfc.

>                                                     struct
>> +netlink_ext_ack *extack) {
>> +       if (likely((flags & ~supp_flags) == 0))
>> +               return true;
>> +
>> +       NL_SET_ERR_MSG_FMT_MOD(extack,
>> +                              "Unsupported match on control.flags %#x",
>> +                              flags);
>> +
>> +       return false;
>> +}
>> +
>> struct flow_stats {
>>         u64     pkts;
>>         u64     bytes;
>> --
> This should not be included in this patch.

It's the default 3 lines of context, as is default in git format-patch.

-- 
Best regards
Asbjørn Sloth Tønnesen
Network Engineer
Fiberby - AS42541