[bpf,0/5] bpf: Allow any source IP in bpf_skb_set_tunnel_key

Message

Paul Chaignon July 15, 2022, 2:59 p.m. UTC

Commit 26101f5ab6bd ("bpf: Add source ip in "struct bpf_tunnel_key"")
added support for getting and setting the outer source IP of encapsulated
packets via the bpf_skb_{get,set}_tunnel_key BPF helper. This change
allows BPF programs to set any IP address as the source, including for
example the IP address of a container running on the same host.

In that last case, however, the encapsulated packets are dropped when
looking up the route because the source IP address isn't assigned to any
interface on the host. To avoid this, we need to set the
FLOWI_FLAG_ANYSRC flag.

Paul Chaignon (5):
  ip_tunnels: Add new flow flags field to ip_tunnel_key
  vxlan: Use ip_tunnel_key flow flags in route lookups
  geneve: Use ip_tunnel_key flow flags in route lookups
  bpf: Set flow flag to allow any source IP in bpf_tunnel_key
  selftests/bpf: Don't assign outer source IP to host

 drivers/net/geneve.c                           |  2 ++
 drivers/net/vxlan/vxlan_core.c                 | 18 ++++++++++++------
 include/net/ip_tunnels.h                       |  1 +
 net/core/filter.c                              |  1 +
 .../selftests/bpf/prog_tests/test_tunnel.c     |  1 -
 5 files changed, 16 insertions(+), 7 deletions(-)