[bpf-next PATCH] bpf: sockmap, test tool support to skip cgroup arg

[John Fastabend <john.fastabend@xxxxxxxxx>]

Its handy to not have to setup a cgroup environment when running
test_sockmap with user specified options. This patch setups a cgroup
environment, similar to how it is done with the auto test suite, when
the user does not provide a cgroup arg.

Signed-off-by: John Fastabend <john.fastabend@xxxxxxxxx>
---
 tools/testing/selftests/bpf/test_sockmap.c |   24 +++++++++++++++++++++---
 1 file changed, 21 insertions(+), 3 deletions(-)

diff --git a/tools/testing/selftests/bpf/test_sockmap.c b/tools/testing/selftests/bpf/test_sockmap.c
index 3845144e2c91..11dfb1f10e15 100644
--- a/tools/testing/selftests/bpf/test_sockmap.c
+++ b/tools/testing/selftests/bpf/test_sockmap.c
@@ -1734,6 +1734,7 @@ int main(int argc, char **argv)
 	int opt, longindex, err, cg_fd = 0;
 	char *bpf_file = BPF_SOCKMAP_FILENAME;
 	int test = PING_PONG;
+	bool cleanup = true;
 
 	if (argc < 2)
 		return test_suite(-1);
@@ -1773,6 +1774,7 @@ int main(int argc, char **argv)
 					cg_fd, optarg);
 				return cg_fd;
 			}
+			cleanup = false;
 			break;
 		case 'r':
 			rate = atoi(optarg);
@@ -1818,9 +1820,23 @@ int main(int argc, char **argv)
 		return test_suite(cg_fd);
 
 	if (!cg_fd) {
-		fprintf(stderr, "%s requires cgroup option: --cgroup <path>\n",
-			argv[0]);
-		return -1;
+		if (setup_cgroup_environment()) {
+			fprintf(stderr, "ERROR: cgroup env failed\n");
+			return -EINVAL;
+		}
+
+		cg_fd = create_and_get_cgroup(CG_PATH);
+		if (cg_fd < 0) {
+			fprintf(stderr,
+				"ERROR: (%i) open cg path failed: %s\n",
+				cg_fd, optarg);
+			return cg_fd;
+		}
+
+		if (join_cgroup(CG_PATH)) {
+			fprintf(stderr, "ERROR: failed to join cgroup\n");
+			return -EINVAL;
+		}
 	}
 
 	err = populate_progs(bpf_file);
@@ -1839,6 +1855,8 @@ int main(int argc, char **argv)
 	options.rate = rate;
 
 	err = run_options(&options, cg_fd, test);
+	if (cleanup)
+		cleanup_cgroup_environment();
 	close(cg_fd);
 	return err;
 }