selftests: Use consistent include paths for libbpf

Fix all selftests to include libbpf header files with the bpf/ prefix, to
be consistent with external users of the library. Also ensure that all
includes of exported libbpf header files (those that are exported on 'make
install' of the library) use bracketed includes instead of quoted.

To not break the build, keep the old include path until everything has been
changed to the new one; a subsequent patch will remove that.

Fixes: 6910d7d3867a ("selftests/bpf: Ensure bpf_helper_defs.h are taken from selftests dir")
Signed-off-by: Toke Høiland-Jørgensen <toke@redhat.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Andrii Nakryiko <andriin@fb.com>
Link: https://lore.kernel.org/bpf/157952560568.1683545.9649335788846513446.stgit@toke.dk

selftests/bpf: convert legacy BPF maps to BTF-defined ones

Convert selftests that were originally left out and new ones added
recently to consistently use BTF-defined maps.

Reported-by: kernel test robot <rong.a.chen@intel.com>
Signed-off-by: Andrii Nakryiko <andriin@fb.com>
Acked-by: Song Liu <songliubraving@fb.com>
Acked-by: Yonghong Song <yhs@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>

selftests, bpf: Add test for veth native XDP

Add a test case for veth native XDP. It checks if XDP_PASS, XDP_TX and
XDP_REDIRECT work properly.

$ cd tools/testing/selftests/bpf
$ make \
TEST_CUSTOM_PROGS= \
TEST_GEN_PROGS= \
TEST_GEN_PROGS_EXTENDED= \
TEST_PROGS_EXTENDED= \
TEST_PROGS="test_xdp_veth.sh" \
run_tests
TAP version 13
1..1
# selftests: bpf: test_xdp_veth.sh
# PING 10.1.1.33 (10.1.1.33) 56(84) bytes of data.
# 64 bytes from 10.1.1.33: icmp_seq=1 ttl=64 time=0.073 ms
#
# --- 10.1.1.33 ping statistics ---
# 1 packets transmitted, 1 received, 0% packet loss, time 0ms
# rtt min/avg/max/mdev = 0.073/0.073/0.073/0.000 ms
# selftests: xdp_veth [PASS]
ok 1 selftests: bpf: test_xdp_veth.sh

Signed-off-by: Toshiaki Makita <toshiaki.makita1@gmail.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>