[bpf-next,v3,0/2] bpf: Add ipip6 and ip6ip decap support for bpf_skb_adjust_room()

Message

Ziyang Xuan (William) Jan. 13, 2023, 9:24 a.m. UTC

Add ipip6 and ip6ip decap support for bpf_skb_adjust_room().
Main use case is for using cls_bpf on ingress hook to decapsulate
IPv4 over IPv6 and IPv6 over IPv4 tunnel packets.

And add ipip6 and ip6ip decap testcases to verify that
bpf_skb_adjust_room() correctly decapsulate ipip6 and ip6ip
tunnel packets.

$./test_tc_tunnel.sh
ipip
encap 192.168.1.1 to 192.168.1.2, type ipip, mac none len 100
test basic connectivity
0
test bpf encap without decap (expect failure)
Ncat: TIMEOUT.
1
test bpf encap with tunnel device decap
0
test bpf encap with bpf decap
0
OK
ipip6
encap 192.168.1.1 to 192.168.1.2, type ipip6, mac none len 100
test basic connectivity
0
test bpf encap without decap (expect failure)
Ncat: TIMEOUT.
1
test bpf encap with tunnel device decap
0
test bpf encap with bpf decap
0
OK
ip6ip6
encap fd::1 to fd::2, type ip6tnl, mac none len 100
test basic connectivity
0
test bpf encap without decap (expect failure)
Ncat: TIMEOUT.
1
test bpf encap with tunnel device decap
0
test bpf encap with bpf decap
0
OK
sit
encap fd::1 to fd::2, type sit, mac none len 100
test basic connectivity
0
test bpf encap without decap (expect failure)
Ncat: TIMEOUT.
1
test bpf encap with tunnel device decap
0
test bpf encap with bpf decap
0
OK
...
OK. All tests passed

v3:
  - Fix compilation failure of selftests/bpf.
  - Combine two new branches in bpf_skb_adjust_room().
  - Simplify description for new flags BPF_F_ADJ_ROOM_DECAP_L3_IP*. 

v2:
  - Use decap flags to indicate the new IP header.
    Do not rely on skb->encapsulation.


Ziyang Xuan (2):
  bpf: Add ipip6 and ip6ip decap support for bpf_skb_adjust_room()
  selftests/bpf: add ipip6 and ip6ip decap to test_tc_tunnel

 include/uapi/linux/bpf.h                      |  7 ++
 net/core/filter.c                             | 31 ++++++-
 tools/include/uapi/linux/bpf.h                |  7 ++
 .../selftests/bpf/progs/test_tc_tunnel.c      | 91 ++++++++++++++++++-
 tools/testing/selftests/bpf/test_tc_tunnel.sh | 15 +--
 5 files changed, 142 insertions(+), 9 deletions(-)