selftests/bpf: Move netcnt test under test_progs

Rewrite to skel and ASSERT macros as well while we are at it.

v3:
- replace -f with -A to make it work with busybox ping.
  -A is available on both busybox and iputils, from the man page:
  On networks with low RTT this mode is essentially equivalent to
  flood mode.

v2:
- don't check result of bpf_map__fd (Yonghong Song)
- remove from .gitignore (Andrii Nakryiko)
- move ping_command into network_helpers (Andrii Nakryiko)
- remove assert() (Andrii Nakryiko)

Signed-off-by: Stanislav Fomichev <sdf@google.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: Yonghong Song <yhs@fb.com>
Link: https://lore.kernel.org/bpf/20210804205524.3748709-1-sdf@google.com

1 files changed, 12 insertions, 0 deletions

diff --git a/tools/testing/selftests/bpf/network_helpers.c b/tools/testing/selftests/bpf/network_helpers.c
index 26468a8f44f3..d6857683397f 100644
--- a/tools/testing/selftests/bpf/network_helpers.c
+++ b/tools/testing/selftests/bpf/network_helpers.c
@@ -310,3 +310,15 @@ int make_sockaddr(int family, const char *addr_str, __u16 port,
 	}
 	return -1;
 }
+
+char *ping_command(int family)
+{
+	if (family == AF_INET6) {
+		/* On some systems 'ping' doesn't support IPv6, so use ping6 if it is present. */
+		if (!system("which ping6 >/dev/null 2>&1"))
+			return "ping6";
+		else
+			return "ping -6";
+	}
+	return "ping";
+}