selftests/bpf: Store BPF object files with .bpf.o extension

BPF object files are, in a way, the final artifact produced as part of
the ahead-of-time compilation process. That makes them somewhat special
compared to "regular" object files, which are a intermediate build
artifacts that can typically be removed safely. As such, it can make
sense to name them differently to make it easier to spot this difference
at a glance.

Among others, libbpf-bootstrap [0] has established the extension .bpf.o
for BPF object files. It seems reasonable to follow this example and
establish the same denomination for selftest build artifacts. To that
end, this change adjusts the corresponding part of the build system and
the test programs loading BPF object files to work with .bpf.o files.

[0] https://github.com/libbpf/libbpf-bootstrap

Suggested-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Daniel Müller <deso@posteo.net>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/20220901222253.1199242-1-deso@posteo.net

selftests/bpf: Fix attach tests retcode checks

Switching to libbpf 1.0 API broke test_sock and test_sysctl as they
check for return of bpf_prog_attach to be exactly -1. Switch the check
to '< 0' instead.

Fixes: b858ba8c52b6 ("selftests/bpf: Use libbpf 1.0 API mode instead of RLIMIT_MEMLOCK")
Signed-off-by: Artem Savkov <asavkov@redhat.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Reviewed-by: Yafang Shao <laoar.shao@gmail.com>
Link: https://lore.kernel.org/bpf/20220421130104.1582053-1-asavkov@redhat.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

selftests/bpf: Use explicit bpf_prog_test_load() calls everywhere

-Dbpf_prog_load_deprecated=bpf_prog_test_load trick is both ugly and
breaks when deprecation goes into effect due to macro magic. Convert all
the uses to explicit bpf_prog_test_load() calls which avoid deprecation
errors and makes everything less magical.

Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Dave Marchevsky <davemarchevsky@fb.com>
Link: https://lore.kernel.org/bpf/20211103220845.2676888-12-andrii@kernel.org

selftests/bpf: Convert legacy prog load APIs to bpf_prog_load()

Convert all the uses of legacy low-level BPF program loading APIs
(mostly bpf_load_program_xattr(), but also some bpf_verify_program()) to
bpf_prog_load() uses.

Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20211103220845.2676888-10-andrii@kernel.org

selftests/bpf: Use __BYTE_ORDER__

Use the compiler-defined __BYTE_ORDER__ instead of the libc-defined
__BYTE_ORDER for consistency.

Signed-off-by: Ilya Leoshkevich <iii@linux.ibm.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20211026010831.748682-4-iii@linux.ibm.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: 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

bpf: Allow narrow loads of bpf_sysctl fields with offset > 0

"ctx:file_pos sysctl:read read ok narrow" works on s390 by accident: it
reads the wrong byte, which happens to have the expected value of 0.
Improve the test by seeking to the 4th byte and expecting 4 instead of
0.

This makes the latent problem apparent: the test attempts to read the
first byte of bpf_sysctl.file_pos, assuming this is the least-significant
byte, which is not the case on big-endian machines: a non-zero offset is
needed.

The point of the test is to verify narrow loads, so we cannot cheat our
way out by simply using BPF_W. The existence of the test means that such
loads have to be supported, most likely because llvm can generate them.
Fix the test by adding a big-endian variant, which uses an offset to
access the least-significant byte of bpf_sysctl.file_pos.

This reveals the final problem: verifier rejects accesses to bpf_sysctl
fields with offset > 0. Such accesses are already allowed for a wide
range of structs: __sk_buff, bpf_sock_addr and sk_msg_md to name a few.
Extend this support to bpf_sysctl by using bpf_ctx_range instead of
offsetof when matching field offsets.

Fixes: 7b146cebe30c ("bpf: Sysctl hook")
Fixes: e1550bfe0de4 ("bpf: Add file_pos field to bpf_sysctl ctx")
Fixes: 9a1027e52535 ("selftests/bpf: Test file_pos field in bpf_sysctl ctx")
Signed-off-by: Ilya Leoshkevich <iii@linux.ibm.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Andrey Ignatov <rdna@fb.com>
Acked-by: Andrii Nakryiko <andriin@fb.com>
Link: https://lore.kernel.org/bpf/20191028122902.9763-1-iii@linux.ibm.com

selftests/bpf: Test narrow load from bpf_sysctl.write

There are tests for full and narrows loads from bpf_sysctl.file_pos, but
for bpf_sysctl.write only full load is tested. Add the missing test.

Suggested-by: Andrey Ignatov <rdna@fb.com>
Signed-off-by: Ilya Leoshkevich <iii@linux.ibm.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Andrey Ignatov <rdna@fb.com>
Link: https://lore.kernel.org/bpf/20191029143027.28681-1-iii@linux.ibm.com

selftests/bpf: delete unused variables in test_sysctl

Remove no longer used variables and avoid compiler warnings.

Signed-off-by: Andrii Nakryiko <andriin@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>

bpf: fix accessing bpf_sysctl.file_pos on s390

"ctx:file_pos sysctl:read write ok" fails on s390 with "Read value !=
nux". This is because verifier rewrites a complete 32-bit
bpf_sysctl.file_pos update to a partial update of the first 32 bits of
64-bit *bpf_sysctl_kern.ppos, which is not correct on big-endian
systems.

Fix by using an offset on big-endian systems.

Ditto for bpf_sysctl.file_pos reads. Currently the test does not detect
a problem there, since it expects to see 0, which it gets with high
probability in error cases, so change it to seek to offset 3 and expect
3 in bpf_sysctl.file_pos.

Fixes: e1550bfe0de4 ("bpf: Add file_pos field to bpf_sysctl ctx")
Signed-off-by: Ilya Leoshkevich <iii@linux.ibm.com>
Acked-by: Yonghong Song <yhs@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/20190816105300.49035-1-iii@linux.ibm.com/

selftests/bpf: fix endianness issues in test_sysctl

A lot of test_sysctl sub-tests fail due to handling strings as a bunch
of immediate values in a little-endian-specific manner.

Fix by wrapping all immediates in bpf_ntohl and the new bpf_be64_to_cpu.

fixup_sysctl_value() dynamically writes an immediate, and thus should be
endianness-aware. Implement this by simply memcpy()ing the raw
user-provided value, since testcase endianness and bpf program
endianness match.

Fixes: 1f5fa9ab6e2e ("selftests/bpf: Test BPF_CGROUP_SYSCTL")
Fixes: 9a1027e52535 ("selftests/bpf: Test file_pos field in bpf_sysctl ctx")
Fixes: 6041c67f28d8 ("selftests/bpf: Test bpf_sysctl_get_name helper")
Fixes: 11ff34f74e32 ("selftests/bpf: Test sysctl_get_current_value helper")
Fixes: 786047dd08de ("selftests/bpf: Test bpf_sysctl_{get,set}_new_value helpers")
Fixes: 8549ddc832d6 ("selftests/bpf: Test bpf_strtol and bpf_strtoul helpers")
Signed-off-by: Ilya Leoshkevich <iii@linux.ibm.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>

selftests/bpf: improve unexpected success reporting in test_syctl

When tests fail because sysctl() unexpectedly succeeds, they print an
inappropriate "Unexpected failure" message and a random errno. Zero
out errno before calling sysctl() and replace the message with
"Unexpected success".

Fixes: 1f5fa9ab6e2e ("selftests/bpf: Test BPF_CGROUP_SYSCTL")
Signed-off-by: Ilya Leoshkevich <iii@linux.ibm.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>

selftests/bpf: fix "ctx:write sysctl:write read ok" on s390

"ctx:write sysctl:write read ok" fails on s390 because it reads the
first byte of an int assuming it's the least-significant one, which
is not the case on big-endian arches. Since we are not testing narrow
accesses here (there is e.g. "ctx:file_pos sysctl:read read ok narrow"
for that), simply read the whole int.

Fixes: 1f5fa9ab6e2e ("selftests/bpf: Test BPF_CGROUP_SYSCTL")
Signed-off-by: Ilya Leoshkevich <iii@linux.ibm.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>

selftests/bpf: C based test for sysctl and strtoX

Add C based test for a few bpf_sysctl_* helpers and bpf_strtoul.

Make sure that sysctl can be identified by name and that multiple
integers can be parsed from sysctl value with bpf_strtoul.

net/ipv4/tcp_mem is chosen as a testing sysctl, it contains 3 unsigned
longs, they all are parsed and compared (val[0] < val[1] < val[2]).

Example of output:
# ./test_sysctl
...
Test case: C prog: deny all writes .. [PASS]
Test case: C prog: deny access by name .. [PASS]
Test case: C prog: read tcp_mem .. [PASS]
Summary: 39 PASSED, 0 FAILED

Signed-off-by: Andrey Ignatov <rdna@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>

selftests/bpf: Test bpf_strtol and bpf_strtoul helpers

Test that bpf_strtol and bpf_strtoul helpers can be used to convert
provided buffer to long or unsigned long correspondingly and return both
correct result and number of consumed bytes, or proper errno.

Example of output:
# ./test_sysctl
..
Test case: bpf_strtoul one number string .. [PASS]
Test case: bpf_strtoul multi number string .. [PASS]
Test case: bpf_strtoul buf_len = 0, reject .. [PASS]
Test case: bpf_strtoul supported base, ok .. [PASS]
Test case: bpf_strtoul unsupported base, EINVAL .. [PASS]
Test case: bpf_strtoul buf with spaces only, EINVAL .. [PASS]
Test case: bpf_strtoul negative number, EINVAL .. [PASS]
Test case: bpf_strtol negative number, ok .. [PASS]
Test case: bpf_strtol hex number, ok .. [PASS]
Test case: bpf_strtol max long .. [PASS]
Test case: bpf_strtol overflow, ERANGE .. [PASS]
Summary: 36 PASSED, 0 FAILED

Signed-off-by: Andrey Ignatov <rdna@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>

selftests/bpf: Test file_pos field in bpf_sysctl ctx

Test access to file_pos field of bpf_sysctl context, both read (incl.
narrow read) and write.

# ./test_sysctl
...
Test case: ctx:file_pos sysctl:read read ok .. [PASS]
Test case: ctx:file_pos sysctl:read read ok narrow .. [PASS]
Test case: ctx:file_pos sysctl:read write ok .. [PASS]
...

Signed-off-by: Andrey Ignatov <rdna@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>

selftests/bpf: Test bpf_sysctl_{get,set}_new_value helpers

Test that new value provided by user space on sysctl write can be read
by bpf_sysctl_get_new_value and overridden by bpf_sysctl_set_new_value.

# ./test_sysctl
...
Test case: sysctl_get_new_value sysctl:read EINVAL .. [PASS]
Test case: sysctl_get_new_value sysctl:write ok .. [PASS]
Test case: sysctl_get_new_value sysctl:write ok long .. [PASS]
Test case: sysctl_get_new_value sysctl:write E2BIG .. [PASS]
Test case: sysctl_set_new_value sysctl:read EINVAL .. [PASS]
Test case: sysctl_set_new_value sysctl:write ok .. [PASS]
Summary: 22 PASSED, 0 FAILED

Signed-off-by: Andrey Ignatov <rdna@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>

selftests/bpf: Test sysctl_get_current_value helper

Test sysctl_get_current_value on sysctl read and write, buffers with
enough space and too small buffers to get E2BIG and truncated result,
etc.

# ./test_sysctl
...
Test case: sysctl_get_current_value sysctl:read ok, gt .. [PASS]
Test case: sysctl_get_current_value sysctl:read ok, eq .. [PASS]
Test case: sysctl_get_current_value sysctl:read E2BIG truncated .. [PASS]
Test case: sysctl_get_current_value sysctl:read EINVAL .. [PASS]
Test case: sysctl_get_current_value sysctl:write ok .. [PASS]
Summary: 16 PASSED, 0 FAILED

Signed-off-by: Andrey Ignatov <rdna@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>

selftests/bpf: Test bpf_sysctl_get_name helper

Test w/ and w/o BPF_F_SYSCTL_BASE_NAME, buffers with enough space and
too small buffers to get E2BIG and truncated result, etc.

# ./test_sysctl
...
Test case: sysctl_get_name sysctl_value:base ok .. [PASS]
Test case: sysctl_get_name sysctl_value:base E2BIG truncated .. [PASS]
Test case: sysctl_get_name sysctl:full ok .. [PASS]
Test case: sysctl_get_name sysctl:full E2BIG truncated .. [PASS]
Test case: sysctl_get_name sysctl:full E2BIG truncated small .. [PASS]
Summary: 11 PASSED, 0 FAILED

Signed-off-by: Andrey Ignatov <rdna@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>

selftests/bpf: Test BPF_CGROUP_SYSCTL

Add unit test for BPF_PROG_TYPE_CGROUP_SYSCTL program type.

Test that program can allow/deny access.
Test both valid and invalid accesses to ctx->write.

Example of output:
# ./test_sysctl
Test case: sysctl wrong attach_type .. [PASS]
Test case: sysctl:read allow all .. [PASS]
Test case: sysctl:read deny all .. [PASS]
Test case: ctx:write sysctl:read read ok .. [PASS]
Test case: ctx:write sysctl:write read ok .. [PASS]
Test case: ctx:write sysctl:read write reject .. [PASS]
Summary: 6 PASSED, 0 FAILED

Signed-off-by: Andrey Ignatov <rdna@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>