// SPDX-License-Identifier: GPL-2.0
/*
* Linux Security Module infrastructure tests
*
* Copyright © 2023 Casey Schaufler <[email protected]>
*/
#define _GNU_SOURCE
#include <linux/lsm.h>
#include <fcntl.h>
#include <string.h>
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <sys/types.h>
#include "common.h"
#define PROCATTR "/proc/self/attr/"
int read_proc_attr(const char *attr, char *value, size_t size)
{
int fd;
int len;
char *path;
len = strlen(PROCATTR) + strlen(attr) + 1;
path = calloc(len, 1);
if (path == NULL)
return -1;
sprintf(path, "%s%s", PROCATTR, attr);
fd = open(path, O_RDONLY);
free(path);
if (fd < 0)
return -1;
len = read(fd, value, size);
close(fd);
/* Ensure value is terminated */
if (len <= 0 || len == size)
return -1;
value[len] = '\0';
path = strchr(value, '\n');
if (path)
*path = '\0';
return 0;
}
int read_sysfs_lsms(char *lsms, size_t size)
{
FILE *fp;
size_t red;
fp = fopen("/sys/kernel/security/lsm", "r");
if (fp == NULL)
return -1;
red = fread(lsms, 1, size, fp);
fclose(fp);
if (red <= 0 || red == size)
return -1;
lsms[red] = '\0';
return 0;
}
int attr_lsm_count(void)
{
char *names = calloc(sysconf(_SC_PAGESIZE), 1);
int count = 0;
if (!names)
return 0;
if (read_sysfs_lsms(names, sysconf(_SC_PAGESIZE)))
return 0;
if (strstr(names, "selinux"))
count++;
if (strstr(names, "smack"))
count++;
if (strstr(names, "apparmor"))
count++;
return count;
}