selftests/bpf: fix lots of silly mistakes pointed out by compiler

Once we enable -Wall for BPF sources, compiler will complain about lots
of unused variables, variables that are set but never read, etc.

Fix all these issues first before enabling -Wall in Makefile.

Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/r/20230309054015.4068562-4-andrii@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>

selftests/bpf: Fix test for 4-byte load from remote_port on big-endian

The context access converter rewrites the 4-byte load from
bpf_sk_lookup->remote_port to a 2-byte load from bpf_sk_lookup_kern
structure.

It means that we cannot treat the destination register contents as a 32-bit
value, or the code will not be portable across big- and little-endian
architectures.

This is exactly the same case as with 4-byte loads from bpf_sock->dst_port
so follow the approach outlined in [1] and treat the register contents as a
16-bit value in the test.

[1]: https://lore.kernel.org/bpf/20220317113920.1068535-5-jakub@cloudflare.com/

Fixes: 2ed0dc5937d3 ("selftests/bpf: Cover 4-byte load from remote_port in bpf_sk_lookup")
Signed-off-by: Jakub Sitnicki <jakub@cloudflare.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Martin KaFai Lau <kafai@fb.com>
Link: https://lore.kernel.org/bpf/20220319183356.233666-4-jakub@cloudflare.com

selftests/bpf: Fix u8 narrow load checks for bpf_sk_lookup remote_port

In commit 9a69e2b385f4 ("bpf: Make remote_port field in struct
bpf_sk_lookup 16-bit wide") ->remote_port field changed from __u32 to
__be16.

However, narrow load tests which exercise 1-byte sized loads from
offsetof(struct bpf_sk_lookup, remote_port) were not adopted to reflect the
change.

As a result, on little-endian we continue testing loads from addresses:

- (__u8 *)&ctx->remote_port + 3
- (__u8 *)&ctx->remote_port + 4

which map to the zero padding following the remote_port field, and don't
break the tests because there is no observable change.

While on big-endian, we observe breakage because tests expect to see zeros
for values loaded from:

- (__u8 *)&ctx->remote_port - 1
- (__u8 *)&ctx->remote_port - 2

Above addresses map to ->remote_ip6 field, which precedes ->remote_port,
and are populated during the bpf_sk_lookup IPv6 tests.

Unsurprisingly, on s390x we observe:

#136/38 sk_lookup/narrow access to ctx v4:OK
#136/39 sk_lookup/narrow access to ctx v6:FAIL

Fix it by removing the checks for 1-byte loads from offsets outside of the
->remote_port field.

Fixes: 9a69e2b385f4 ("bpf: Make remote_port field in struct bpf_sk_lookup 16-bit wide")
Suggested-by: Ilya Leoshkevich <iii@linux.ibm.com>
Signed-off-by: Jakub Sitnicki <jakub@cloudflare.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Martin KaFai Lau <kafai@fb.com>
Link: https://lore.kernel.org/bpf/20220319183356.233666-3-jakub@cloudflare.com

selftests/bpf: Cover 4-byte load from remote_port in bpf_sk_lookup

Extend the context access tests for sk_lookup prog to cover the surprising
case of a 4-byte load from the remote_port field, where the expected value
is actually shifted by 16 bits.

Signed-off-by: Jakub Sitnicki <jakub@cloudflare.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Yonghong Song <yhs@fb.com>
Link: https://lore.kernel.org/bpf/20220209184333.654927-3-jakub@cloudflare.com

selftests/bpf: Add tests for accessing ingress_ifindex in bpf_sk_lookup

A new field was added to the bpf_sk_lookup data that users can access.
Add tests that validate that the new ingress_ifindex field contains the
right data.

Signed-off-by: Mark Pashmfouroush <markpash@cloudflare.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20211110111016.5670-3-markpash@cloudflare.com

selftests/bpf: Remove SEC("version") from test progs

Since commit 6c4fc209fcf9d ("bpf: remove useless version check for prog
load") these "version" sections, which result in bpf_attr.kern_version
being set, have been unnecessary.

Remove them so that it's obvious to folks using selftests as a guide that
"modern" BPF progs don't need this section.

Signed-off-by: Dave Marchevsky <davemarchevsky@fb.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20211007231234.2223081-1-davemarchevsky@fb.com

selftests/bpf: Switch sk_lookup selftests to strict SEC("sk_lookup") use

Update "sk_lookup/" definition to be a stand-alone type specifier,
with backwards-compatible prefix match logic in non-libbpf-1.0 mode.

Currently in selftests all the "sk_lookup/<whatever>" uses just use
<whatever> for duplicated unique name encoding, which is redundant as
BPF program's name (C function name) uniquely and descriptively
identifies the intended use for such BPF programs.

With libbpf's SEC_DEF("sk_lookup") definition updated, switch existing
sk_lookup programs to use "unqualified" SEC("sk_lookup") section names,
with no random text after it.

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/20210928161946.2512801-11-andrii@kernel.org

selftests/bpf: Normalize all the rest SEC() uses

Normalize all the other non-conforming SEC() usages across all
selftests. This is in preparation for libbpf to start to enforce
stricter SEC() rules in libbpf 1.0 mode.

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/20210928161946.2512801-5-andrii@kernel.org

selftests: bpf: Convert sk_lookup ctx access tests to PROG_TEST_RUN

Convert the selftests for sk_lookup narrow context access to use
PROG_TEST_RUN instead of creating actual sockets. This ensures that
ctx is populated correctly when using PROG_TEST_RUN.

Assert concrete values since we now control remote_ip and remote_port.

Signed-off-by: Lorenz Bauer <lmb@cloudflare.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20210303101816.36774-4-lmb@cloudflare.com

selftests/bpf: Fix endianness issues in sk_lookup/ctx_narrow_access

This test makes a lot of narrow load checks while assuming little
endian architecture, and therefore fails on s390.

Fix by introducing LSB and LSW macros and using them to perform narrow
loads.

Fixes: 0ab5539f8584 ("selftests/bpf: Tests for BPF_SK_LOOKUP attach point")
Signed-off-by: Ilya Leoshkevich <iii@linux.ibm.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20200929201814.44360-1-iii@linux.ibm.com

selftests/bpf: Tests for BPF_SK_LOOKUP attach point

Add tests to test_progs that exercise:

- attaching/detaching/querying programs to BPF_SK_LOOKUP hook,
- redirecting socket lookup to a socket selected by BPF program,
- failing a socket lookup on BPF program's request,
- error scenarios for selecting a socket from BPF program,
- accessing BPF program context,
- attaching and running multiple BPF programs.

Run log:

bash-5.0# ./test_progs -n 70
#70/1 query lookup prog:OK
#70/2 TCP IPv4 redir port:OK
#70/3 TCP IPv4 redir addr:OK
#70/4 TCP IPv4 redir with reuseport:OK
#70/5 TCP IPv4 redir skip reuseport:OK
#70/6 TCP IPv6 redir port:OK
#70/7 TCP IPv6 redir addr:OK
#70/8 TCP IPv4->IPv6 redir port:OK
#70/9 TCP IPv6 redir with reuseport:OK
#70/10 TCP IPv6 redir skip reuseport:OK
#70/11 UDP IPv4 redir port:OK
#70/12 UDP IPv4 redir addr:OK
#70/13 UDP IPv4 redir with reuseport:OK
#70/14 UDP IPv4 redir skip reuseport:OK
#70/15 UDP IPv6 redir port:OK
#70/16 UDP IPv6 redir addr:OK
#70/17 UDP IPv4->IPv6 redir port:OK
#70/18 UDP IPv6 redir and reuseport:OK
#70/19 UDP IPv6 redir skip reuseport:OK
#70/20 TCP IPv4 drop on lookup:OK
#70/21 TCP IPv6 drop on lookup:OK
#70/22 UDP IPv4 drop on lookup:OK
#70/23 UDP IPv6 drop on lookup:OK
#70/24 TCP IPv4 drop on reuseport:OK
#70/25 TCP IPv6 drop on reuseport:OK
#70/26 UDP IPv4 drop on reuseport:OK
#70/27 TCP IPv6 drop on reuseport:OK
#70/28 sk_assign returns EEXIST:OK
#70/29 sk_assign honors F_REPLACE:OK
#70/30 sk_assign accepts NULL socket:OK
#70/31 access ctx->sk:OK
#70/32 narrow access to ctx v4:OK
#70/33 narrow access to ctx v6:OK
#70/34 sk_assign rejects TCP established:OK
#70/35 sk_assign rejects UDP connected:OK
#70/36 multi prog - pass, pass:OK
#70/37 multi prog - drop, drop:OK
#70/38 multi prog - pass, drop:OK
#70/39 multi prog - drop, pass:OK
#70/40 multi prog - pass, redir:OK
#70/41 multi prog - redir, pass:OK
#70/42 multi prog - drop, redir:OK
#70/43 multi prog - redir, drop:OK
#70/44 multi prog - redir, redir:OK
#70 sk_lookup:OK
Summary: 1/44 PASSED, 0 SKIPPED, 0 FAILED

Signed-off-by: Jakub Sitnicki <jakub@cloudflare.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20200717103536.397595-16-jakub@cloudflare.com