90 lines · c
1// SPDX-License-Identifier: GPL-2.02/*3 * Linux Security Module infrastructure tests4 *5 * Copyright © 2023 Casey Schaufler <casey@schaufler-ca.com>6 */7 8#define _GNU_SOURCE9#include <linux/lsm.h>10#include <fcntl.h>11#include <string.h>12#include <stdio.h>13#include <stdlib.h>14#include <unistd.h>15#include <sys/types.h>16#include "common.h"17 18#define PROCATTR "/proc/self/attr/"19 20int read_proc_attr(const char *attr, char *value, size_t size)21{22 int fd;23 int len;24 char *path;25 26 len = strlen(PROCATTR) + strlen(attr) + 1;27 path = calloc(len, 1);28 if (path == NULL)29 return -1;30 sprintf(path, "%s%s", PROCATTR, attr);31 32 fd = open(path, O_RDONLY);33 free(path);34 35 if (fd < 0)36 return -1;37 len = read(fd, value, size);38 39 close(fd);40 41 /* Ensure value is terminated */42 if (len <= 0 || len == size)43 return -1;44 value[len] = '\0';45 46 path = strchr(value, '\n');47 if (path)48 *path = '\0';49 50 return 0;51}52 53int read_sysfs_lsms(char *lsms, size_t size)54{55 FILE *fp;56 size_t red;57 58 fp = fopen("/sys/kernel/security/lsm", "r");59 if (fp == NULL)60 return -1;61 red = fread(lsms, 1, size, fp);62 fclose(fp);63 64 if (red <= 0 || red == size)65 return -1;66 lsms[red] = '\0';67 return 0;68}69 70int attr_lsm_count(void)71{72 char *names = calloc(sysconf(_SC_PAGESIZE), 1);73 int count = 0;74 75 if (!names)76 return 0;77 78 if (read_sysfs_lsms(names, sysconf(_SC_PAGESIZE)))79 return 0;80 81 if (strstr(names, "selinux"))82 count++;83 if (strstr(names, "smack"))84 count++;85 if (strstr(names, "apparmor"))86 count++;87 88 return count;89}90