From: Alexei Starovoitov Date: Fri, 5 Jun 2026 22:28:29 +0000 (-0700) Subject: Merge branch 'bpf-update-transport_header-when-encapsulating-udp-tunnel-in-lwt' X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=f091801c85a5991cb4acacfb5b15daa265b674dd;p=thirdparty%2Flinux.git Merge branch 'bpf-update-transport_header-when-encapsulating-udp-tunnel-in-lwt' Leon Hwang says: ==================== bpf: Update transport_header when encapsulating UDP tunnel in lwt Currently, bpf_lwt_push_ip_encap() does not update skb->transport_header. When a driver, e.g. ice, reuses the stale skb->transport_header to offload checksum computation to NIC hardware, VxLAN packets encapsulated by bpf_lwt_push_encap() helper may be dropped due to incorrect checksum. Update skb->transport_header in bpf_lwt_push_ip_encap() whenever the encapsulated packet uses UDP, so checksum offload works correctly. Changes: v3 -> v4: * Address comments from Emil: * Make the logic of skb_set_transport_header() clearer in patch #1. * Fold the code of fexit_lwt_push_ip_encap() into test_lwt_ip_encap.c in patch #2. * Resolve assorted issues of test in patch #2. * v3: https://lore.kernel.org/bpf/20260601150203.20352-1-leon.hwang@linux.dev/ v2 -> v3: * Drop patch #1 and #2 of v2 that aim to resolve potential issues reported by sashiko (per Alexei). * Check target IP version and UDP tunnel in test (per sashiko). * v2: https://lore.kernel.org/bpf/20260529151351.69911-1-leon.hwang@linux.dev/ v1 -> v2: * Address sashiko's reviews: * Fix TOCTOU issue in lwt to avoid changing hdr after checks. * Add check iph->ihl < 5 in lwt to avoid infinite-loop in MIPS driver. * Update comment style in selftests with BPF comment style. * v1: https://lore.kernel.org/bpf/20260525142650.2569-1-leon.hwang@linux.dev/ ==================== Link: https://patch.msgid.link/20260602150931.49629-1-leon.hwang@linux.dev Signed-off-by: Alexei Starovoitov --- f091801c85a5991cb4acacfb5b15daa265b674dd