// 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;}