1 // SPDX-License-Identifier: GPL-2.0 2 /* 3 * Linux Security Module infrastructure tests 4 * 5 * Copyright © 2023 Casey Schaufler <casey@schaufler-ca.com> 6 */ 7 8 #define _GNU_SOURCE 9 #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 20 int 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 53 int 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 70 int 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