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[34.85.235.172]) by smtp.gmail.com with ESMTPSA id 956f58d0204a3-65c2e86e35csm5782052d50.16.2026.05.04.10.15.13 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 04 May 2026 10:15:13 -0700 (PDT) Date: Mon, 04 May 2026 13:15:12 -0400 From: Willem de Bruijn To: Nick Hudson , bpf@vger.kernel.org, netdev@vger.kernel.org, Willem de Bruijn , Martin KaFai Lau Cc: Nick Hudson , Max Tottenham , Anna Glasgall , Daniel Borkmann , Alexei Starovoitov , Andrii Nakryiko , Eduard Zingerman , Kumar Kartikeya Dwivedi , "David S. Miller" , Eric Dumazet , Jakub Kicinski , Paolo Abeni , linux-kernel@vger.kernel.org Message-ID: In-Reply-To: <20260504101759.3319427-6-nhudson@akamai.com> References: <20260504101759.3319427-1-nhudson@akamai.com> <20260504101759.3319427-6-nhudson@akamai.com> Subject: Re: [PATCH v6 5/6] bpf: clear decap state on skb_adjust_room shrink path Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 7bit Nick Hudson wrote: > On shrink in bpf_skb_adjust_room(), apply decapsulation state updates > according to BPF_F_ADJ_ROOM_DECAP_* flags. > > For GSO skbs, clear only the tunnel gso_type bits that correspond to the > requested decap layer: > - DECAP_L4_UDP: SKB_GSO_UDP_TUNNEL{,_CSUM} > - DECAP_L4_GRE: SKB_GSO_GRE{,_CSUM} > - DECAP_IPXIP4: SKB_GSO_IPXIP4 > - DECAP_IPXIP6: SKB_GSO_IPXIP6 > > Then clear skb->encapsulation only if no tunnel GSO bits remain, keeping > encapsulation set for cases such as ESP-in-UDP where tunnel state remains. > > For non-GSO skbs, there are no tunnel GSO bits to consult, so clear > skb->encapsulation directly when DECAP_L4_* or DECAP_IPXIP_* flags are set. > > This keeps decap state handling consistent between GSO and non-GSO packets. > > Co-developed-by: Max Tottenham > Signed-off-by: Max Tottenham > Co-developed-by: Anna Glasgall > Signed-off-by: Anna Glasgall > Signed-off-by: Nick Hudson Reviewed-by: Willem de Bruijn