selftests/bpf: fix missing BPF object files

After commit afef88e65554 ("selftests/bpf: Store BPF object files with
.bpf.o extension"), we should use *.bpf.o instead of *.o.

In addition, use the BPF_FILE variable to save the BPF object file name,
which can be better identified and modified.

Fixes: afef88e65554 ("selftests/bpf: Store BPF object files with .bpf.o extension")
Signed-off-by: Wang Yufen <wangyufen@huawei.com>
Acked-by: Stanislav Fomichev <sdf@google.com>
Link: https://lore.kernel.org/r/1666235134-562-1-git-send-email-wangyufen@huawei.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>

bpf, selftests: Test BPF_FLOW_DISSECTOR_CONTINUE

The dissector program returns BPF_FLOW_DISSECTOR_CONTINUE (and avoids
setting skb->flow_keys or last_dissection map) in case it encounters
IP packets whose (outer) source address is 127.0.0.127.

Additional test is added to prog_tests/flow_dissector.c which sets
this address as test's pkk.iph.saddr, with the expected retval of
BPF_FLOW_DISSECTOR_CONTINUE.

Also, legacy test_flow_dissector.sh was similarly augmented.

Signed-off-by: Shmulik Ladkani <shmulik.ladkani@gmail.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Reviewed-by: Stanislav Fomichev <sdf@google.com>
Acked-by: John Fastabend <john.fastabend@gmail.com>
Link: https://lore.kernel.org/bpf/20220821113519.116765-5-shmulik.ladkani@gmail.com

selftests/bpf: Fix flow dissector tests

- update custom loader to search by name, not section name
- update bpftool commands to use proper pin path

Signed-off-by: Stanislav Fomichev <sdf@google.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20211021214814.1236114-4-sdf@google.com

selftests/bpf: Add test based on port range for BPF flow dissector

Add a simple test to make sure that a filter based on specified port
range classifies packets correctly.

Signed-off-by: Yoshiki Komachi <komachi.yoshiki@gmail.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Petar Penkov <ppenkov@google.com>
Acked-by: John Fastabend <john.fastabend@gmail.com>
Link: https://lore.kernel.org/bpf/20200117070533.402240-3-komachi.yoshiki@gmail.com

selftests/bpf: Set rp_filter in test_flow_dissector

Many distributions enable rp_filter. However, the flow dissector test
generates packets that have 1.1.1.1 set as (inner) source address without
this address being reachable. This causes the selftest to fail.

The selftests should not assume a particular initial configuration. Switch
off rp_filter.

Fixes: 50b3ed57dee9 ("selftests/bpf: test bpf flow dissection")
Signed-off-by: Jiri Benc <jbenc@redhat.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Petar Penkov <ppenkov@google.com>
Link: https://lore.kernel.org/bpf/513a298f53e99561d2f70b2e60e2858ea6cda754.1570539863.git.jbenc@redhat.com

selftests/bpf: add test for BPF flow dissector in the root namespace

Make sure non-root namespaces get an error if root flow dissector is
attached.

Cc: Petar Penkov <ppenkov@google.com>
Acked-by: Song Liu <songliubraving@fb.com>

Signed-off-by: Stanislav Fomichev <sdf@google.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>

selftests/bpf: rename flow dissector section to flow_dissector

Makes it compatible with the logic that derives program type
from section name in libbpf_prog_type_by_name.

Signed-off-by: Stanislav Fomichev <sdf@google.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>

selftests/bpf: test bpf flow dissection

Adds a test that sends different types of packets over multiple
tunnels and verifies that valid packets are dissected correctly. To do
so, a tc-flower rule is added to drop packets on UDP src port 9, and
packets are sent from ports 8, 9, and 10. Only the packets on port 9
should be dropped. Because tc-flower relies on the flow dissector to
match flows, correct classification demonstrates correct dissection.

Also add support logic to load the BPF program and to inject the test
packets.

Signed-off-by: Petar Penkov <ppenkov@google.com>
Signed-off-by: Willem de Bruijn <willemb@google.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>