On Tue, Apr 9, 2019 at 10:08 AM Alan Maguire <alan.maguire@xxxxxxxxxx> wrote: > > Extend bpf_skb_adjust_room growth to mark inner MAC header so that > L2 encapsulation can be used for tc tunnels. > > Patch #1 extends the existing test_tc_tunnel to support UDP > encapsulation; later we want to be able to test MPLS over UDP and > MPLS over GRE encapsulation. > > Patch #2 adds the BPF_F_ADJ_ROOM_ENCAP_L2(len) macro, which > allows specification of inner mac length. Other approaches were > explored prior to taking this approach. Specifically, I tried > automatically computing the inner mac length on the basis of the > specified flags (so inner maclen for GRE/IPv4 encap is the len_diff > specified to bpf_skb_adjust_room minus GRE + IPv4 header length > for example). Problem with this is that we don't know for sure > what form of GRE/UDP header we have; is it a full GRE header, > or is it a FOU UDP header or generic UDP encap header? My fear > here was we'd end up with an explosion of flags. The other approach > tried was to support inner L2 header marking as a separate room > adjustment, i.e. adjust for L3/L4 encap, then call > bpf_skb_adjust_room for L2 encap. This can be made to work but > because it imposed an order on operations, felt a bit clunky. > > Patch #3 syncs tools/ bpf.h. > > Patch #4 extends the tests again to support MPLSoverGRE, > MPLSoverUDP, and transparent ethernet bridging (TEB) where > the inner L2 header is an ethernet header. Testing of BPF > encap against tunnels is done for cases where configuration > of such tunnels is possible (MPLSoverGRE[6], MPLSoverUDP, > gre[6]tap), and skipped otherwise. Testing of BPF encap/decap > is always carried out. > > Changes since v2: > - updated tools/testing/selftest/bpf/config with FOU/MPLS CONFIG > variables (patches 1, 4) > - reduced noise in patch 1 by avoiding unnecessary movement of code > - eliminated inner_mac variable in bpf_skb_net_grow (patch 2) > > Changes since v1: > - fixed formatting of commit references. > - BPF_F_ADJ_ROOM_FIXED_GSO flag enabled on all variants (patch 1) > - fixed fou6 options for UDP encap; checksum errors observed were > due to the fact fou6 tunnel was not set up with correct ipproto > options (41 -6). 0 checksums work fine (patch 1) > - added definitions for mask and shift used in setting L2 length > (patch 2) > - allow udp encap with fixed GSO (patch 2) > - changed "elen" to "l2_len" to be more descriptive (patch 4) > > > Alan Maguire (4): > selftests_bpf: extend test_tc_tunnel for UDP encap > bpf: add layer 2 encap support to bpf_skb_adjust_room > bpf: sync bpf.h to tools/ for BPF_F_ADJ_ROOM_ENCAP_L2 > selftests_bpf: add L2 encap to test_tc_tunnel > > include/uapi/linux/bpf.h | 10 + > net/core/filter.c | 12 +- > tools/include/uapi/linux/bpf.h | 10 + > tools/testing/selftests/bpf/config | 8 + > tools/testing/selftests/bpf/progs/test_tc_tunnel.c | 321 +++++++++++++++++---- > tools/testing/selftests/bpf/test_tc_tunnel.sh | 136 +++++++-- > 6 files changed, 417 insertions(+), 80 deletions(-) For the series: Acked-by: Willem de Bruijn <willemb@xxxxxxxxxx> Thanks Alan. (quick response due to iterative review: checked out both v2 and v3 series from patchwork (a super useful feature!) and did a git diff)
