selftests/bpf: Use bpf_{btf,link,map,prog}_get_info_by_fd()

Use the new type-safe wrappers around bpf_obj_get_info_by_fd().
Fix a prog/map mixup in prog_holds_map().

Signed-off-by: Ilya Leoshkevich <iii@linux.ibm.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20230214231221.249277-6-iii@linux.ibm.com

selftests/bpf: Use libbpf 1.0 API mode instead of RLIMIT_MEMLOCK

We have switched to memcg-based memory accouting and thus the rlimit is
not needed any more. LIBBPF_STRICT_AUTO_RLIMIT_MEMLOCK was introduced in
libbpf for backward compatibility, so we can use it instead now. After
this change, the header tools/testing/selftests/bpf/bpf_rlimit.h can be
removed.

This patch also removes the useless header sys/resource.h from many files
in tools/testing/selftests/bpf/.

Signed-off-by: Yafang Shao <laoar.shao@gmail.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20220409125958.92629-3-laoar.shao@gmail.com

bpf, selftests: Use single cgroup helpers for both test_sockmap/progs

Nearly every user of cgroup helpers does the same sequence of API calls. So
push these into a single helper cgroup_setup_and_join. The cases that do
a bit of extra logic are test_progs which currently uses an env variable
to decide if it needs to setup the cgroup environment or can use an
existingi environment. And then tests that are doing cgroup tests
themselves. We skip these cases for now.

Signed-off-by: John Fastabend <john.fastabend@gmail.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Andrii Nakryiko <andriin@fb.com>
Link: https://lore.kernel.org/bpf/159623335418.30208.15807461815525100199.stgit@john-XPS-13-9370

selftests/bpf: Don't hard-code root cgroup id

Commit 40430452fd5d ("kernfs: use 64bit inos if ino_t is 64bit") changed
the way cgroup ids are exposed to the userspace. Instead of assuming
fixed root id, let's query it.

Fixes: 40430452fd5d ("kernfs: use 64bit inos if ino_t is 64bit")
Signed-off-by: Stanislav Fomichev <sdf@google.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20191202200143.250793-1-sdf@google.com

selftests/bpf: fix incorrect users of create_and_get_cgroup

We have some tests that assume create_and_get_cgroup returns -1 on error
which is incorrect (it returns 0 on error). Since fd might be zero in
general case, change create_and_get_cgroup to return -1 on error
and fix the users that assume 0 on error.

Fixes: f269099a7e7a ("tools/bpf: add a selftest for bpf_get_current_cgroup_id() helper")
Fixes: 7d2c6cfc5411 ("bpf: use --cgroup in test_suite if supplied")

v2:
- instead of fixing the uses that assume -1 on error, convert the users
that assume 0 on error (fd might be zero in general case)

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

selftests/bpf: Selftest for bpf_skb_ancestor_cgroup_id

Add selftests for bpf_skb_ancestor_cgroup_id helper.

test_skb_cgroup_id.sh prepares testing interface and adds tc qdisc and
filter for it using BPF object compiled from test_skb_cgroup_id_kern.c
program.

BPF program in test_skb_cgroup_id_kern.c gets ancestor cgroup id using
the new helper at different levels of cgroup hierarchy that skb belongs
to, including root level and non-existing level, and saves it to the map
where the key is the level of corresponding cgroup and the value is its
id.

To trigger BPF program, user space program test_skb_cgroup_id_user is
run. It adds itself into testing cgroup and sends UDP datagram to
link-local multicast address of testing interface. Then it reads cgroup
ids saved in kernel for different levels from the BPF map and compares
them with those in user space. They must be equal for every level of
ancestry.

Example of run:
# ./test_skb_cgroup_id.sh
Wait for testing link-local IP to become available ... OK
Note: 8 bytes struct bpf_elf_map fixup performed due to size mismatch!
[PASS]

Signed-off-by: Andrey Ignatov <rdna@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>