1 // SPDX-License-Identifier: GPL-2.0-or-later 2 /* 3 * 4 * mdp - make dummy policy 5 * 6 * When pointed at a kernel tree, builds a dummy policy for that kernel 7 * with exactly one type with full rights to itself. 8 * 9 * Copyright (C) IBM Corporation, 2006 10 * 11 * Authors: Serge E. Hallyn <serue@us.ibm.com> 12 */ 13 14 15 /* NOTE: we really do want to use the kernel headers here */ 16 #define __EXPORTED_HEADERS__ 17 18 #include <stdio.h> 19 #include <stdlib.h> 20 #include <unistd.h> 21 #include <string.h> 22 #include <linux/kconfig.h> 23 24 static void usage(char *name) 25 { 26 printf("usage: %s [-m] policy_file context_file\n", name); 27 exit(1); 28 } 29 30 /* Class/perm mapping support */ 31 struct security_class_mapping { 32 const char *name; 33 const char *perms[sizeof(unsigned) * 8 + 1]; 34 }; 35 36 #include "classmap.h" 37 #include "initial_sid_to_string.h" 38 39 int main(int argc, char *argv[]) 40 { 41 int i, j, mls = 0; 42 int initial_sid_to_string_len; 43 char **arg, *polout, *ctxout; 44 45 FILE *fout; 46 47 if (argc < 3) 48 usage(argv[0]); 49 arg = argv+1; 50 if (argc==4 && strcmp(argv[1], "-m") == 0) { 51 mls = 1; 52 arg++; 53 } 54 polout = *arg++; 55 ctxout = *arg; 56 57 fout = fopen(polout, "w"); 58 if (!fout) { 59 printf("Could not open %s for writing\n", polout); 60 usage(argv[0]); 61 } 62 63 /* print out the classes */ 64 for (i = 0; secclass_map[i].name; i++) 65 fprintf(fout, "class %s\n", secclass_map[i].name); 66 fprintf(fout, "\n"); 67 68 initial_sid_to_string_len = sizeof(initial_sid_to_string) / sizeof (char *); 69 /* print out the sids */ 70 for (i = 1; i < initial_sid_to_string_len; i++) { 71 const char *name = initial_sid_to_string[i]; 72 73 if (name) 74 fprintf(fout, "sid %s\n", name); 75 else 76 fprintf(fout, "sid unused%d\n", i); 77 } 78 fprintf(fout, "\n"); 79 80 /* print out the class permissions */ 81 for (i = 0; secclass_map[i].name; i++) { 82 struct security_class_mapping *map = &secclass_map[i]; 83 fprintf(fout, "class %s\n", map->name); 84 fprintf(fout, "{\n"); 85 for (j = 0; map->perms[j]; j++) 86 fprintf(fout, "\t%s\n", map->perms[j]); 87 fprintf(fout, "}\n\n"); 88 } 89 fprintf(fout, "\n"); 90 91 /* print out mls declarations and constraints */ 92 if (mls) { 93 fprintf(fout, "sensitivity s0;\n"); 94 fprintf(fout, "sensitivity s1;\n"); 95 fprintf(fout, "dominance { s0 s1 }\n"); 96 fprintf(fout, "category c0;\n"); 97 fprintf(fout, "category c1;\n"); 98 fprintf(fout, "level s0:c0.c1;\n"); 99 fprintf(fout, "level s1:c0.c1;\n"); 100 #define SYSTEMLOW "s0" 101 #define SYSTEMHIGH "s1:c0.c1" 102 for (i = 0; secclass_map[i].name; i++) { 103 struct security_class_mapping *map = &secclass_map[i]; 104 105 fprintf(fout, "mlsconstrain %s {\n", map->name); 106 for (j = 0; map->perms[j]; j++) 107 fprintf(fout, "\t%s\n", map->perms[j]); 108 /* 109 * This requires all subjects and objects to be 110 * single-level (l2 eq h2), and that the subject 111 * level dominate the object level (h1 dom h2) 112 * in order to have any permissions to it. 113 */ 114 fprintf(fout, "} (l2 eq h2 and h1 dom h2);\n\n"); 115 } 116 } 117 118 /* types, roles, and allows */ 119 fprintf(fout, "type base_t;\n"); 120 fprintf(fout, "role base_r;\n"); 121 fprintf(fout, "role base_r types { base_t };\n"); 122 for (i = 0; secclass_map[i].name; i++) 123 fprintf(fout, "allow base_t base_t:%s *;\n", 124 secclass_map[i].name); 125 fprintf(fout, "user user_u roles { base_r }"); 126 if (mls) 127 fprintf(fout, " level %s range %s - %s", SYSTEMLOW, 128 SYSTEMLOW, SYSTEMHIGH); 129 fprintf(fout, ";\n"); 130 131 #define SUBJUSERROLETYPE "user_u:base_r:base_t" 132 #define OBJUSERROLETYPE "user_u:object_r:base_t" 133 134 /* default sids */ 135 for (i = 1; i < initial_sid_to_string_len; i++) { 136 const char *name = initial_sid_to_string[i]; 137 138 if (name) 139 fprintf(fout, "sid %s ", name); 140 else 141 fprintf(fout, "sid unused%d\n", i); 142 fprintf(fout, SUBJUSERROLETYPE "%s\n", 143 mls ? ":" SYSTEMLOW : ""); 144 } 145 fprintf(fout, "\n"); 146 147 #define FS_USE(behavior, fstype) \ 148 fprintf(fout, "fs_use_%s %s " OBJUSERROLETYPE "%s;\n", \ 149 behavior, fstype, mls ? ":" SYSTEMLOW : "") 150 151 /* 152 * Filesystems whose inode labels can be fetched via getxattr. 153 */ 154 #ifdef CONFIG_EXT2_FS_SECURITY 155 FS_USE("xattr", "ext2"); 156 #endif 157 #ifdef CONFIG_EXT4_FS_SECURITY 158 #ifdef CONFIG_EXT4_USE_FOR_EXT2 159 FS_USE("xattr", "ext2"); 160 #endif 161 FS_USE("xattr", "ext3"); 162 FS_USE("xattr", "ext4"); 163 #endif 164 #ifdef CONFIG_JFS_SECURITY 165 FS_USE("xattr", "jfs"); 166 #endif 167 #ifdef CONFIG_REISERFS_FS_SECURITY 168 FS_USE("xattr", "reiserfs"); 169 #endif 170 #ifdef CONFIG_JFFS2_FS_SECURITY 171 FS_USE("xattr", "jffs2"); 172 #endif 173 #ifdef CONFIG_XFS_FS 174 FS_USE("xattr", "xfs"); 175 #endif 176 #ifdef CONFIG_GFS2_FS 177 FS_USE("xattr", "gfs2"); 178 #endif 179 #ifdef CONFIG_BTRFS_FS 180 FS_USE("xattr", "btrfs"); 181 #endif 182 #ifdef CONFIG_F2FS_FS_SECURITY 183 FS_USE("xattr", "f2fs"); 184 #endif 185 #ifdef CONFIG_OCFS2_FS 186 FS_USE("xattr", "ocsfs2"); 187 #endif 188 #ifdef CONFIG_OVERLAY_FS 189 FS_USE("xattr", "overlay"); 190 #endif 191 #ifdef CONFIG_SQUASHFS_XATTR 192 FS_USE("xattr", "squashfs"); 193 #endif 194 195 /* 196 * Filesystems whose inodes are labeled from allocating task. 197 */ 198 FS_USE("task", "pipefs"); 199 FS_USE("task", "sockfs"); 200 201 /* 202 * Filesystems whose inode labels are computed from both 203 * the allocating task and the superblock label. 204 */ 205 #ifdef CONFIG_UNIX98_PTYS 206 FS_USE("trans", "devpts"); 207 #endif 208 #ifdef CONFIG_HUGETLBFS 209 FS_USE("trans", "hugetlbfs"); 210 #endif 211 #ifdef CONFIG_TMPFS 212 FS_USE("trans", "tmpfs"); 213 #endif 214 #ifdef CONFIG_DEVTMPFS 215 FS_USE("trans", "devtmpfs"); 216 #endif 217 #ifdef CONFIG_POSIX_MQUEUE 218 FS_USE("trans", "mqueue"); 219 #endif 220 221 #define GENFSCON(fstype, prefix) \ 222 fprintf(fout, "genfscon %s %s " OBJUSERROLETYPE "%s\n", \ 223 fstype, prefix, mls ? ":" SYSTEMLOW : "") 224 225 /* 226 * Filesystems whose inodes are labeled from path prefix match 227 * relative to the filesystem root. Depending on the filesystem, 228 * only a single label for all inodes may be supported. Here 229 * we list the filesystem types for which per-file labeling is 230 * supported using genfscon; any other filesystem type can also 231 * be added by only with a single entry for all of its inodes. 232 */ 233 #ifdef CONFIG_PROC_FS 234 GENFSCON("proc", "/"); 235 #endif 236 #ifdef CONFIG_SECURITY_SELINUX 237 GENFSCON("selinuxfs", "/"); 238 #endif 239 #ifdef CONFIG_SYSFS 240 GENFSCON("sysfs", "/"); 241 #endif 242 #ifdef CONFIG_DEBUG_FS 243 GENFSCON("debugfs", "/"); 244 #endif 245 #ifdef CONFIG_TRACING 246 GENFSCON("tracefs", "/"); 247 #endif 248 #ifdef CONFIG_PSTORE 249 GENFSCON("pstore", "/"); 250 #endif 251 GENFSCON("cgroup", "/"); 252 GENFSCON("cgroup2", "/"); 253 254 fclose(fout); 255 256 fout = fopen(ctxout, "w"); 257 if (!fout) { 258 printf("Wrote policy, but cannot open %s for writing\n", ctxout); 259 usage(argv[0]); 260 } 261 fprintf(fout, "/ " OBJUSERROLETYPE "%s\n", mls ? ":" SYSTEMLOW : ""); 262 fprintf(fout, "/.* " OBJUSERROLETYPE "%s\n", mls ? ":" SYSTEMLOW : ""); 263 fclose(fout); 264 265 return 0; 266 } 267