From: Willem de Bruijn <will...@google.com>
BPF allows for dynamic tunneling, choosing the tunnel destination and
features on-demand. Extend bpf_skb_adjust_room to allow for efficient
tunneling at the TC hooks.
Patch 1
is a performance optimization, avoiding an unnecessary unclone
for the TCP hot path.
Patches 2..6
introduce a regression test. These can be squashed, but the code is
arguably more readable when gradually expanding the feature set.
Patch 7
is a performance optimization, avoid copying network headers
that are going to be overwritten. This also simplifies the bpf
program.
Patch 8
reenables bpf_skb_adjust_room for UDP packets.
Patch 9
add support for gso packets, which require additional metadata set
in the skb. It does this through new flags to bpf_skb_adjust_room.
other alternatives considered:
- individual bpf_{ipip, gre, udp, ..}_encap functions that combine
adjust room and bpf_skb_store_bytes.
- new bpf_encap_fixup function called after bpf_skb_adjust_room and
bpf_skb_store_bytes that parses the tunnel and sets the metadata.
Patches 10..13
expand the regression test to make use of the new features and
enable the GSO testcases.
these could be interleaved with each of the new features, were it
not for the separate sync bpf.h patch.
Willem de Bruijn (13):
bpf: in bpf_skb_adjust_room avoid copy in tx fast path
selftests/bpf: bpf tunnel encap test
selftests/bpf: expand bpf tunnel test with decap
selftests/bpf: expand bpf tunnel test to ipv6
selftests/bpf: extend bpf tunnel test with gre
selftests/bpf: extend bpf tunnel test with tso
bpf: add bpf_skb_adjust_room mode BPF_ADJ_ROOM_MAC
bpf: add bpf_skb_adjust_room flag BPF_F_ADJ_ROOM_FIXED_GSO
bpf: add bpf_skb_adjust_room encap flags
bpf: Sync bpf.h to tools
selftests/bpf: convert bpf tunnel test to BPF_ADJ_ROOM_MAC
selftests/bpf: convert bpf tunnel test to BPF_F_ADJ_ROOM_FIXED_GSO
selftests/bpf: convert bpf tunnel test to encap modes
include/uapi/linux/bpf.h | 22 +-
net/core/filter.c | 124 +++++++--
tools/include/uapi/linux/bpf.h | 22 +-
tools/testing/selftests/bpf/Makefile | 3 +-
tools/testing/selftests/bpf/config | 2 +
.../selftests/bpf/progs/test_tc_tunnel.c | 261 ++++++++++++++++++
tools/testing/selftests/bpf/test_tc_tunnel.sh | 178 ++++++++++++
7 files changed, 580 insertions(+), 32 deletions(-)
create mode 100644 tools/testing/selftests/bpf/progs/test_tc_tunnel.c
create mode 100755 tools/testing/selftests/bpf/test_tc_tunnel.sh
--
2.21.0.225.g810b269d1ac-goog
