selftests/bpf: Check -EBUSY for the recurred bpf_setsockopt(TCP_CONGESTION)

This patch changes the bpf_dctcp test to ensure the recurred
bpf_setsockopt(TCP_CONGESTION) returns -EBUSY.

Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org>
Link: https://lore.kernel.org/r/20220929070407.965581-6-martin.lau@linux.dev
Signed-off-by: Alexei Starovoitov <ast@kernel.org>

bpf: selftests: Add dctcp fallback test

This patch makes the bpf_dctcp test to fallback to cubic by
using setsockopt(TCP_CONGESTION) when the tcp flow is not
ecn ready.

It also checks setsockopt() is not available to release().

The settimeo() from the network_helpers.h is used, so the local
one is removed.

Signed-off-by: Martin KaFai Lau <kafai@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20210824173026.3979130-1-kafai@fb.com

bpf: selftests: Bpf_cubic and bpf_dctcp calling kernel functions

This patch removes the bpf implementation of tcp_slow_start()
and tcp_cong_avoid_ai(). Instead, it directly uses the kernel
implementation.

It also replaces the bpf_cubic_undo_cwnd implementation by directly
calling tcp_reno_undo_cwnd(). bpf_dctcp also directly calls
tcp_reno_cong_avoid() instead.

Signed-off-by: Martin KaFai Lau <kafai@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20210325015246.1551062-1-kafai@fb.com

bpf: selftest: Remove enum tcp_ca_state from bpf_tcp_helpers.h

The enum tcp_ca_state is available in <linux/tcp.h>.
Remove it from the bpf_tcp_helpers.h to avoid conflict when the bpf prog
needs to include both both <linux/tcp.h> and bpf_tcp_helpers.h.

Modify the bpf_cubic.c and bpf_dctcp.c to use <linux/tcp.h> instead.
The <linux/stddef.h> is needed by <linux/tcp.h>.

Signed-off-by: Martin KaFai Lau <kafai@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20200925000452.3859313-1-kafai@fb.com

bpf: Add tests for bpf_sk_storage to bpf_tcp_ca

This patch adds test to exercise the bpf_sk_storage_get()
and bpf_sk_storage_delete() helper from the bpf_dctcp.c.

The setup and check on the sk_storage is done immediately
before and after the connect().

This patch also takes this chance to move the pthread_create()
after the connect() has been done. That will remove the need of
the "wait_thread" label.

Signed-off-by: Martin KaFai Lau <kafai@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Yonghong Song <yhs@fb.com>
Link: https://lore.kernel.org/bpf/20200320152107.2169904-1-kafai@fb.com

libbpf: Merge selftests' bpf_trace_helpers.h into libbpf's bpf_tracing.h

Move BPF_PROG, BPF_KPROBE, and BPF_KRETPROBE macro into libbpf's bpf_tracing.h
header to make it available for non-selftests users.

Signed-off-by: Andrii Nakryiko <andriin@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20200229231112.1240137-5-andriin@fb.com

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

selftests/bpf: Add BPF_PROG, BPF_KPROBE, and BPF_KRETPROBE macros

Streamline BPF_TRACE_x macro by moving out return type and section attribute
definition out of macro itself. That makes those function look in source code
similar to other BPF programs. Additionally, simplify its usage by determining
number of arguments automatically (so just single BPF_TRACE vs a family of
BPF_TRACE_1, BPF_TRACE_2, etc). Also, allow more natural function argument
syntax without commas inbetween argument type and name.

Given this helper is useful not only for tracing tp_btf/fenty/fexit programs,
but could be used for LSM programs and others following the same pattern,
rename BPF_TRACE macro into more generic BPF_PROG. Existing BPF_TRACE_x
usages in selftests are converted to new BPF_PROG macro.

Following the same pattern, define BPF_KPROBE and BPF_KRETPROBE macros for
nicer usage of kprobe/kretprobe arguments, respectively. BPF_KRETPROBE, adopts
same convention used by fexit programs, that last defined argument is probed
function's return result.

v4->v5:
- fix test_overhead test (__set_task_comm is void) (Alexei);

v3->v4:
- rebased and fixed one more BPF_TRACE_x occurence (Alexei);

v2->v3:
- rename to shorter and as generic BPF_PROG (Alexei);

v1->v2:
- verified GCC handles pragmas as expected;
- added descriptions to macros;
- converted new STRUCT_OPS selftest to BPF_HANDLER (worked as expected);
- added original context as 'ctx' parameter, for cases where it has to be
passed into BPF helpers. This might cause an accidental naming collision,
unfortunately, but at least it's easy to work around. Fortunately, this
situation produces quite legible compilation error:

progs/bpf_dctcp.c:46:6: error: redefinition of 'ctx' with a different type: 'int' vs 'unsigned long long *'
int ctx = 123;
^
progs/bpf_dctcp.c:42:6: note: previous definition is here
void BPF_HANDLER(dctcp_init, struct sock *sk)
^
./bpf_trace_helpers.h:58:32: note: expanded from macro 'BPF_HANDLER'
____##name(unsigned long long *ctx, ##args)

Signed-off-by: Andrii Nakryiko <andriin@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Martin KaFai Lau <kafai@fb.com>
Link: https://lore.kernel.org/bpf/20200110211634.1614739-1-andriin@fb.com

bpf: Add bpf_dctcp example

This patch adds a bpf_dctcp example. It currently does not do
no-ECN fallback but the same could be done through the cgrp2-bpf.

Signed-off-by: Martin KaFai Lau <kafai@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20200109003517.3856825-1-kafai@fb.com