BPF_F_REDIRECT_INTERNAL
BUILD_BUG_ON(BPF_F_REDIRECT_INTERNAL & BPF_F_REDIRECT_FLAGS);
if (unlikely(flags & (~(BPF_F_INGRESS) | BPF_F_REDIRECT_INTERNAL)))
(flags & (~(BPF_F_INGRESS) | BPF_F_REDIRECT_INTERNAL))))