1 files changed, 37 insertions, 0 deletions
diff --git a/tools/testing/selftests/bpf/sysctl_helpers.c b/tools/testing/selftests/bpf/sysctl_helpers.c
new file mode 100644
index 000000000000..e2bd824f12d5
--- /dev/null
+++ b/tools/testing/selftests/bpf/sysctl_helpers.c
@@ -0,0 +1,37 @@
+// SPDX-License-Identifier: GPL-2.0
+#include <stdio.h>
+#include <errno.h>
+#include <string.h>
+
+#include "sysctl_helpers.h"
+#include "test_progs.h"
+
+int sysctl_set(const char *sysctl_path, char *old_val, const char *new_val)
+{
+	int ret = 0;
+	FILE *fp;
+
+	fp = fopen(sysctl_path, "r+");
+	if (!fp)
+		return -errno;
+	if (old_val && fscanf(fp, "%s", old_val) <= 0) {
+		ret = -ENOENT;
+	} else if (!old_val || strcmp(old_val, new_val) != 0) {
+		fseek(fp, 0, SEEK_SET);
+		if (fprintf(fp, "%s", new_val) < 0)
+			ret = -errno;
+	}
+	fclose(fp);
+
+	return ret;
+}
+
+int sysctl_set_or_fail(const char *sysctl_path, char *old_val, const char *new_val)
+{
+	int err;
+
+	err = sysctl_set(sysctl_path, old_val, new_val);
+	if (err)
+		PRINT_FAIL("failed to set %s to %s: %s\n", sysctl_path, new_val, strerror(-err));
+	return err;
+}