bpf, sockmap: Test progs verifier error with latest clang

With a relatively recent clang (7090c10273119) and with this commit
to fix warnings in selftests (c8ed668593972) that uses __sink(err)
to resolve unused variables. We get the following verifier error.

root@6e731a24b33a:/host/tools/testing/selftests/bpf# ./test_sockmap
libbpf: prog 'bpf_sockmap': BPF program load failed: Permission denied
libbpf: prog 'bpf_sockmap': -- BEGIN PROG LOAD LOG --
0: R1=ctx(off=0,imm=0) R10=fp0
; op = (int) skops->op;
0: (61) r2 = *(u32 *)(r1 +0) ; R1=ctx(off=0,imm=0) R2_w=scalar(umax=4294967295,var_off=(0x0; 0xffffffff))
; switch (op) {
1: (16) if w2 == 0x4 goto pc+5 ; R2_w=scalar(umax=4294967295,var_off=(0x0; 0xffffffff))
2: (56) if w2 != 0x5 goto pc+15 ; R2_w=5
; lport = skops->local_port;
3: (61) r2 = *(u32 *)(r1 +68) ; R1=ctx(off=0,imm=0) R2_w=scalar(umax=4294967295,var_off=(0x0; 0xffffffff))
; if (lport == 10000) {
4: (56) if w2 != 0x2710 goto pc+13 18: R1=ctx(off=0,imm=0) R2=scalar(umax=4294967295,var_off=(0x0; 0xffffffff)) R10=fp0
; __sink(err);
18: (bc) w1 = w0
R0 !read_ok
processed 18 insns (limit 1000000) max_states_per_insn 0 total_states 2 peak_states 2 mark_read 1
-- END PROG LOAD LOG --
libbpf: prog 'bpf_sockmap': failed to load: -13
libbpf: failed to load object 'test_sockmap_kern.bpf.o'
load_bpf_file: (-1) No such file or directory
ERROR: (-1) load bpf failed
libbpf: prog 'bpf_sockmap': BPF program load failed: Permission denied
libbpf: prog 'bpf_sockmap': -- BEGIN PROG LOAD LOG --
0: R1=ctx(off=0,imm=0) R10=fp0
; op = (int) skops->op;
0: (61) r2 = *(u32 *)(r1 +0) ; R1=ctx(off=0,imm=0) R2_w=scalar(umax=4294967295,var_off=(0x0; 0xffffffff))
; switch (op) {
1: (16) if w2 == 0x4 goto pc+5 ; R2_w=scalar(umax=4294967295,var_off=(0x0; 0xffffffff))
2: (56) if w2 != 0x5 goto pc+15 ; R2_w=5
; lport = skops->local_port;
3: (61) r2 = *(u32 *)(r1 +68) ; R1=ctx(off=0,imm=0) R2_w=scalar(umax=4294967295,var_off=(0x0; 0xffffffff))
; if (lport == 10000) {
4: (56) if w2 != 0x2710 goto pc+13 18: R1=ctx(off=0,imm=0) R2=scalar(umax=4294967295,var_off=(0x0; 0xffffffff)) R10=fp0
; __sink(err);
18: (bc) w1 = w0
R0 !read_ok
processed 18 insns (limit 1000000) max_states_per_insn 0 total_states 2 peak_states 2 mark_read 1
-- END PROG LOAD LOG --
libbpf: prog 'bpf_sockmap': failed to load: -13
libbpf: failed to load object 'test_sockhash_kern.bpf.o'
load_bpf_file: (-1) No such file or directory
ERROR: (-1) load bpf failed
libbpf: prog 'bpf_sockmap': BPF program load failed: Permission denied
libbpf: prog 'bpf_sockmap': -- BEGIN PROG LOAD LOG --
0: R1=ctx(off=0,imm=0) R10=fp0
; op = (int) skops->op;
0: (61) r2 = *(u32 *)(r1 +0) ; R1=ctx(off=0,imm=0) R2_w=scalar(umax=4294967295,var_off=(0x0; 0xffffffff))
; switch (op) {
1: (16) if w2 == 0x4 goto pc+5 ; R2_w=scalar(umax=4294967295,var_off=(0x0; 0xffffffff))
2: (56) if w2 != 0x5 goto pc+15 ; R2_w=5
; lport = skops->local_port;
3: (61) r2 = *(u32 *)(r1 +68) ; R1=ctx(off=0,imm=0) R2_w=scalar(umax=4294967295,var_off=(0x0; 0xffffffff))
; if (lport == 10000) {
4: (56) if w2 != 0x2710 goto pc+13 18: R1=ctx(off=0,imm=0) R2=scalar(umax=4294967295,var_off=(0x0; 0xffffffff)) R10=fp0
; __sink(err);
18: (bc) w1 = w0
R0 !read_ok
processed 18 insns (limit 1000000) max_states_per_insn 0 total_states 2 peak_states 2 mark_read 1
-- END PROG LOAD LOG --

To fix simply remove the err value because its not actually used anywhere
in the testing. We can investigate the root cause later. Future patch should
probably actually test the err value as well. Although if the map updates
fail they will get caught eventually by userspace.

Fixes: c8ed668593972 ("selftests/bpf: fix lots of silly mistakes pointed out by compiler")
Signed-off-by: John Fastabend <john.fastabend@gmail.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Reviewed-by: Jakub Sitnicki <jakub@cloudflare.com>
Link: https://lore.kernel.org/bpf/20230523025618.113937-15-john.fastabend@gmail.com

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: Check bpf_msg_push_data return value

bpf_msg_push_data may return a non-zero value to indicate an error. The
return value should be checked to prevent undetected errors.

To indicate an error, the BPF programs now perform a different action
than their intended one to make the userspace test program notice the
error, i.e., the programs supposed to pass/redirect drop, the program
supposed to drop passes.

Fixes: 84fbfe026acaa ("bpf: test_sockmap add options to use msg_push_data")
Signed-off-by: Felix Maurer <fmaurer@redhat.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: John Fastabend <john.fastabend@gmail.com>
Link: https://lore.kernel.org/bpf/89f767bb44005d6b4dd1f42038c438f76b3ebfad.1644601294.git.fmaurer@redhat.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

bpf, sockmap: Update selftests to use skb_adjust_room

Instead of working around TLS headers in sockmap selftests use the
new skb_adjust_room helper. This allows us to avoid special casing
the receive side to skip headers.

Signed-off-by: John Fastabend <john.fastabend@gmail.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/160160100932.7052.3646935243867660528.stgit@john-Precision-5820-Tower

bpf, sockmap: Add ingres skb tests that utilize merge skbs

Add a test to check strparser merging skbs is working.

Signed-off-by: John Fastabend <john.fastabend@gmail.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Martin KaFai Lau <kafai@fb.com>
Link: https://lore.kernel.org/bpf/159312681884.18340.4922800172600252370.stgit@john-XPS-13-9370

bpf, selftests: Add test for ktls with skb bpf ingress policy

This adds a test for bpf ingress policy. To ensure data writes happen
as expected with extra TLS headers we run these tests with data
verification enabled by default. This will test receive packets have
"PASS" stamped into the front of the payload.

Signed-off-by: John Fastabend <john.fastabend@gmail.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/159079363965.5745.3390806911628980210.stgit@john-Precision-5820-Tower
Signed-off-by: Alexei Starovoitov <ast@kernel.org>

bpf: Selftests, remove prints from sockmap tests

The prints in the test_sockmap programs were only useful when we
didn't have enough control over test infrastructure to know from
user program what was being pushed into kernel side.

Now that we have or will shortly have better test controls lets
remove the printers. This means we can remove half the programs
and cleanup bpf side.

Signed-off-by: John Fastabend <john.fastabend@gmail.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Reviewed-by: Jakub Sitnicki <jakub@cloudflare.com>
Link: https://lore.kernel.org/bpf/158939720756.15176.9806965887313279429.stgit@john-Precision-5820-Tower

bpf: Selftests, move sockmap bpf prog header into progs

Moves test_sockmap_kern.h into progs directory but does not change
code at all.

Signed-off-by: John Fastabend <john.fastabend@gmail.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Reviewed-by: Jakub Sitnicki <jakub@cloudflare.com>
Link: https://lore.kernel.org/bpf/158939718921.15176.5766299102332077086.stgit@john-Precision-5820-Tower