selftests/bpf: Use ping_command() for IPv6 pings in lwt_ip_encap

lwt_ip_encap hardcodes the ping6 binary for its IPv6 pings. iputils
merged ping6 into ping long ago and distros have started dropping the
compat symlink -- Arch's iputils 20250605 ships only arping, clockdiff,
ping and tracepath. There, every lwt_ip_encap subtest fails:

  check_ping_ok:FAIL:ip netns exec ns-lwt-ip-encap-1-0101330 ping6 -c 1 \
    -W1 -I veth1 fb04::1 > /dev/null unexpected error: 256 (errno 2)
  #217/1   lwt_ip_encap_ipv4/egress:FAIL

The IPv4 subtests fail too, because check_ping_ok() pings both families.
SYS() runs the command through system(), so a missing binary is
indistinguishable from an unreachable peer.

network_helpers.c has had ping_command() for exactly this since commit
372642ea83ff ("selftests/bpf: Move netcnt test under test_progs"): it
falls back to "ping -6" when ping6 is not present. lwt_ip_encap.c is the
last hardcoded ping6 user. Fix that.

Fixes: f5e288943e2c ("selftests/bpf: Move test_lwt_ip_encap to test_progs")
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Song Liu <song@kernel.org>
Link: https://lore.kernel.org/bpf/20260813213558.3103179-1-andrii@kernel.org

0 files changed, 0 insertions, 0 deletions