On Tue, 27 Oct 2020 11:15:31 -0600 David Ahern <dsahern@xxxxxxxxx> wrote: > On 10/27/20 10:26 AM, Jesper Dangaard Brouer wrote: > > The BPF-helpers for FIB lookup (bpf_xdp_fib_lookup and bpf_skb_fib_lookup) > > can perform MTU check and return BPF_FIB_LKUP_RET_FRAG_NEEDED. The BPF-prog > > don't know the MTU value that caused this rejection. > > > > If the BPF-prog wants to implement PMTU (Path MTU Discovery) (rfc1191) it > > need to know this MTU value for the ICMP packet. > > > > Patch change lookup and result struct bpf_fib_lookup, to contain this MTU > > value as output via a union with 'tot_len' as this is the value used for > > the MTU lookup. > > > > Signed-off-by: Jesper Dangaard Brouer <brouer@xxxxxxxxxx> > > --- > > include/uapi/linux/bpf.h | 11 +++++++++-- > > net/core/filter.c | 17 ++++++++++++----- > > tools/include/uapi/linux/bpf.h | 11 +++++++++-- > > 3 files changed, 30 insertions(+), 9 deletions(-) > > Reviewed-by: David Ahern <dsahern@xxxxxxxxxx> Thanks a lot for the review. I didn't propagate-it-over in V5 of this patch, as I changed the name of the output member from mtu to mtu_result in V5. Please review V5 and give your review consent. -- Best regards, Jesper Dangaard Brouer MSc.CS, Principal Kernel Engineer at Red Hat LinkedIn: http://www.linkedin.com/in/brouer
