The FIB lookup example[1] show how the IP-header field tot_len (iph->tot_len) is used as input to perform the MTU check. The recently added MTU check helper bpf_check_mtu() should also support this type of MTU check. Lets add this feature before merge window, please. This is a followup to 34b2021cc616 ("bpf: Add BPF-helper for MTU checking"). [1] samples/bpf/xdp_fwd_kern.c --- Jesper Dangaard Brouer (2): bpf: BPF-helper for MTU checking add length input selftests/bpf: Tests using bpf_check_mtu BPF-helper input mtu_len param include/uapi/linux/bpf.h | 17 ++-- net/core/filter.c | 12 ++- tools/testing/selftests/bpf/prog_tests/check_mtu.c | 4 + tools/testing/selftests/bpf/progs/test_check_mtu.c | 92 ++++++++++++++++++++ 4 files changed, 117 insertions(+), 8 deletions(-) --