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: 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

bpf: selftests: A few improvements to network_helpers.c

This patch makes a few changes to the network_helpers.c

1) Enforce SO_RCVTIMEO and SO_SNDTIMEO
This patch enforces timeout to the network fds through setsockopt
SO_RCVTIMEO and SO_SNDTIMEO.

It will remove the need for SOCK_NONBLOCK that requires a more demanding
timeout logic with epoll/select, e.g. epoll_create, epoll_ctrl, and
then epoll_wait for timeout.

That removes the need for connect_wait() from the
cgroup_skb_sk_lookup.c. The needed change is made in
cgroup_skb_sk_lookup.c.

2) start_server():
Add optional addr_str and port to start_server().
That removes the need of the start_server_with_port(). The caller
can pass addr_str==NULL and/or port==0.

I have a future tcp-hdr-opt test that will pass a non-NULL addr_str
and it is in general useful for other future tests.

"int timeout_ms" is also added to control the timeout
on the "accept(listen_fd)".

3) connect_to_fd(): Fully use the server_fd.
The server sock address has already been obtained from
getsockname(server_fd). The sockaddr includes the family,
so the "int family" arg is redundant.

Since the server address is obtained from server_fd, there
is little reason not to get the server's socket type from the
server_fd also. getsockopt(server_fd) can be used to do that,
so "int type" arg is also removed.

"int timeout_ms" is added.

4) connect_fd_to_fd():
"int timeout_ms" is added.
Some code is also refactored to connect_fd_to_addr() which is
shared with connect_to_fd().

5) Preserve errno:
Some callers need to check errno, e.g. cgroup_skb_sk_lookup.c.
Make changes to do it more consistently in save_errno_close()
and log_err().

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/20200702004852.2103003-1-kafai@fb.com

selftests/bpf: Add cgroup_skb/egress test for load_bytes_relative

When cgroup_skb/egress triggers the MAC header is not set. Added a
test that asserts reading MAC header is a -EFAULT but NET header
succeeds. The test result from within the eBPF program is stored in
an 1-element array map that the userspace then reads and asserts on.

Another assertion is added that reading from a large offset, past
the end of packet, returns -EFAULT.

Signed-off-by: YiFei Zhu <zhuyifei@google.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Reviewed-by: Stanislav Fomichev <sdf@google.com>
Link: https://lore.kernel.org/bpf/9028ccbea4385a620e69c0a104f469ffd655c01e.1591812755.git.zhuyifei@google.com