Re: [PATCH net v3 2/3] net: stmmac: fix l3l4 filter rejecting unsupported offload requests

[Maxime Chevallier]

Hi,

On 7/14/26 04:37, muhammad.nazim.amirul.nazle.asmade@xxxxxxxxxx wrote:
> From: Nazim Amirul <muhammad.nazim.amirul.nazle.asmade@xxxxxxxxxx>
> 
> The basic flow parser in tc_add_basic_flow() does not validate match
> keys before proceeding. Unsupported offload configurations such as
> partial protocol masks, non-IPv4 network proto, or non-TCP/UDP transport
> proto are silently accepted instead of returning -EOPNOTSUPP.
> 
> Add validation to return -EOPNOTSUPP early for:
> - No network or transport proto present in the key
> - Partial protocol mask (only full mask supported)
> - Network proto is not IPv4
> - Transport proto is not TCP or UDP
> 
> Each rejection includes an extack message so the user knows which part
> of the match is unsupported.
> 
> Also propagate -EOPNOTSUPP from tc_add_basic_flow() in tc_add_flow()
> by returning it directly rather than using break. The break was silently
> discarding the error for FLOW_CLS_REPLACE operations where entry->in_use
> is already true, causing tc_add_flow() to return 0 (success) for
> unsupported replace requests.
> 
> Fixes: 425eabddaf0f ("net: stmmac: Implement L3/L4 Filters using TC Flower")
> Signed-off-by: Rohan G Thomas <rohan.g.thomas@xxxxxxxxxx>
> Signed-off-by: Nazim Amirul <muhammad.nazim.amirul.nazle.asmade@xxxxxxxxxx>

Reviewed-by: Maxime Chevallier <maxime.chevallier@xxxxxxxxxxx>

Maxime