1 /*- 2 * SPDX-License-Identifier: BSD-2-Clause-FreeBSD 3 * 4 * Copyright (c) 1999, 2000, 2001, 2002 Robert N. M. Watson 5 * Copyright (c) 2002, 2003 Networks Associates Technology, Inc. 6 * All rights reserved. 7 * 8 * This software was developed by Robert Watson for the TrustedBSD Project. 9 * 10 * This software was developed for the FreeBSD Project in part by Network 11 * Associates Laboratories, the Security Research Division of Network 12 * Associates, Inc. under DARPA/SPAWAR contract N66001-01-C-8035 ("CBOSS"), 13 * as part of the DARPA CHATS research program. 14 * 15 * Redistribution and use in source and binary forms, with or without 16 * modification, are permitted provided that the following conditions 17 * are met: 18 * 1. Redistributions of source code must retain the above copyright 19 * notice, this list of conditions and the following disclaimer. 20 * 2. Redistributions in binary form must reproduce the above copyright 21 * notice, this list of conditions and the following disclaimer in the 22 * documentation and/or other materials provided with the distribution. 23 * 24 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 25 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 26 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 27 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 28 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 29 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 30 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 31 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 32 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 33 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 34 * SUCH DAMAGE. 35 */ 36 37 #include <sys/cdefs.h> 38 __FBSDID("$FreeBSD$"); 39 40 #include <sys/types.h> 41 #include <sys/queue.h> 42 #include <sys/sysctl.h> 43 44 #include <dlfcn.h> 45 #include <errno.h> 46 #include <limits.h> 47 #include <stdio.h> 48 #include <stdlib.h> 49 #include <string.h> 50 #include <unistd.h> 51 52 #include <sys/mac.h> 53 54 static int internal_initialized; 55 56 /* 57 * Maintain a list of default label preparations for various object 58 * types. Each name will appear only once in the list. 59 * 60 * XXXMAC: Not thread-safe. 61 */ 62 static LIST_HEAD(, label_default) label_default_head; 63 struct label_default { 64 char *ld_name; 65 char *ld_labels; 66 LIST_ENTRY(label_default) ld_entries; 67 }; 68 69 static void 70 mac_destroy_labels(void) 71 { 72 struct label_default *ld; 73 74 while ((ld = LIST_FIRST(&label_default_head))) { 75 free(ld->ld_name); 76 free(ld->ld_labels); 77 LIST_REMOVE(ld, ld_entries); 78 free(ld); 79 } 80 } 81 82 static void 83 mac_destroy_internal(void) 84 { 85 86 mac_destroy_labels(); 87 88 internal_initialized = 0; 89 } 90 91 static int 92 mac_add_type(const char *name, const char *labels) 93 { 94 struct label_default *ld, *ld_new; 95 char *name_dup, *labels_dup; 96 97 /* 98 * Speculatively allocate all the memory now to avoid allocating 99 * later when we will someday hold a mutex. 100 */ 101 name_dup = strdup(name); 102 if (name_dup == NULL) { 103 errno = ENOMEM; 104 return (-1); 105 } 106 labels_dup = strdup(labels); 107 if (labels_dup == NULL) { 108 free(name_dup); 109 errno = ENOMEM; 110 return (-1); 111 } 112 ld_new = malloc(sizeof(*ld)); 113 if (ld_new == NULL) { 114 free(name_dup); 115 free(labels_dup); 116 errno = ENOMEM; 117 return (-1); 118 } 119 120 /* 121 * If the type is already present, replace the current entry 122 * rather than add a new instance. 123 */ 124 for (ld = LIST_FIRST(&label_default_head); ld != NULL; 125 ld = LIST_NEXT(ld, ld_entries)) { 126 if (strcmp(name, ld->ld_name) == 0) 127 break; 128 } 129 130 if (ld != NULL) { 131 free(ld->ld_labels); 132 ld->ld_labels = labels_dup; 133 labels_dup = NULL; 134 } else { 135 ld = ld_new; 136 ld->ld_name = name_dup; 137 ld->ld_labels = labels_dup; 138 139 ld_new = NULL; 140 name_dup = NULL; 141 labels_dup = NULL; 142 143 LIST_INSERT_HEAD(&label_default_head, ld, ld_entries); 144 } 145 146 if (name_dup != NULL) 147 free(name_dup); 148 if (labels_dup != NULL) 149 free(labels_dup); 150 if (ld_new != NULL) 151 free(ld_new); 152 153 return (0); 154 } 155 156 static char * 157 next_token(char **string) 158 { 159 char *token; 160 161 token = strsep(string, " \t"); 162 while (token != NULL && *token == '\0') 163 token = strsep(string, " \t"); 164 165 return (token); 166 } 167 168 static int 169 mac_init_internal(int ignore_errors) 170 { 171 const char *filename; 172 char line[LINE_MAX]; 173 FILE *file; 174 int error; 175 176 error = 0; 177 178 LIST_INIT(&label_default_head); 179 180 filename = secure_getenv("MAC_CONFFILE"); 181 if (filename == NULL) 182 filename = MAC_CONFFILE; 183 file = fopen(filename, "re"); 184 if (file == NULL) 185 return (0); 186 187 while (fgets(line, LINE_MAX, file)) { 188 char *comment, *parse, *statement; 189 190 if (line[strlen(line)-1] == '\n') 191 line[strlen(line)-1] = '\0'; 192 else { 193 if (ignore_errors) 194 continue; 195 fclose(file); 196 error = EINVAL; 197 goto just_return; 198 } 199 200 /* Remove any comment. */ 201 comment = line; 202 parse = strsep(&comment, "#"); 203 204 /* Blank lines OK. */ 205 statement = next_token(&parse); 206 if (statement == NULL) 207 continue; 208 209 if (strcmp(statement, "default_labels") == 0) { 210 char *name, *labels; 211 212 name = next_token(&parse); 213 labels = next_token(&parse); 214 if (name == NULL || labels == NULL || 215 next_token(&parse) != NULL) { 216 if (ignore_errors) 217 continue; 218 error = EINVAL; 219 fclose(file); 220 goto just_return; 221 } 222 223 if (mac_add_type(name, labels) == -1) { 224 if (ignore_errors) 225 continue; 226 fclose(file); 227 goto just_return; 228 } 229 } else if (strcmp(statement, "default_ifnet_labels") == 0 || 230 strcmp(statement, "default_file_labels") == 0 || 231 strcmp(statement, "default_process_labels") == 0) { 232 char *labels, *type; 233 234 if (strcmp(statement, "default_ifnet_labels") == 0) 235 type = "ifnet"; 236 else if (strcmp(statement, "default_file_labels") == 0) 237 type = "file"; 238 else if (strcmp(statement, "default_process_labels") == 239 0) 240 type = "process"; 241 242 labels = next_token(&parse); 243 if (labels == NULL || next_token(&parse) != NULL) { 244 if (ignore_errors) 245 continue; 246 error = EINVAL; 247 fclose(file); 248 goto just_return; 249 } 250 251 if (mac_add_type(type, labels) == -1) { 252 if (ignore_errors) 253 continue; 254 fclose(file); 255 goto just_return; 256 } 257 } else { 258 if (ignore_errors) 259 continue; 260 fclose(file); 261 error = EINVAL; 262 goto just_return; 263 } 264 } 265 266 fclose(file); 267 268 internal_initialized = 1; 269 270 just_return: 271 if (error != 0) 272 mac_destroy_internal(); 273 return (error); 274 } 275 276 static int 277 mac_maybe_init_internal(void) 278 { 279 280 if (!internal_initialized) 281 return (mac_init_internal(1)); 282 else 283 return (0); 284 } 285 286 int 287 mac_reload(void) 288 { 289 290 if (internal_initialized) 291 mac_destroy_internal(); 292 return (mac_init_internal(0)); 293 } 294 295 int 296 mac_free(struct mac *mac) 297 { 298 299 if (mac->m_string != NULL) 300 free(mac->m_string); 301 free(mac); 302 303 return (0); 304 } 305 306 int 307 mac_from_text(struct mac **mac, const char *text) 308 { 309 310 *mac = (struct mac *) malloc(sizeof(**mac)); 311 if (*mac == NULL) 312 return (ENOMEM); 313 314 (*mac)->m_string = strdup(text); 315 if ((*mac)->m_string == NULL) { 316 free(*mac); 317 *mac = NULL; 318 return (ENOMEM); 319 } 320 321 (*mac)->m_buflen = strlen((*mac)->m_string)+1; 322 323 return (0); 324 } 325 326 int 327 mac_to_text(struct mac *mac, char **text) 328 { 329 330 *text = strdup(mac->m_string); 331 if (*text == NULL) 332 return (ENOMEM); 333 return (0); 334 } 335 336 int 337 mac_prepare(struct mac **mac, const char *elements) 338 { 339 340 if (strlen(elements) >= MAC_MAX_LABEL_BUF_LEN) 341 return (EINVAL); 342 343 *mac = (struct mac *) malloc(sizeof(**mac)); 344 if (*mac == NULL) 345 return (ENOMEM); 346 347 (*mac)->m_string = malloc(MAC_MAX_LABEL_BUF_LEN); 348 if ((*mac)->m_string == NULL) { 349 free(*mac); 350 *mac = NULL; 351 return (ENOMEM); 352 } 353 354 strcpy((*mac)->m_string, elements); 355 (*mac)->m_buflen = MAC_MAX_LABEL_BUF_LEN; 356 357 return (0); 358 } 359 360 int 361 mac_prepare_type(struct mac **mac, const char *name) 362 { 363 struct label_default *ld; 364 int error; 365 366 error = mac_maybe_init_internal(); 367 if (error != 0) 368 return (error); 369 370 for (ld = LIST_FIRST(&label_default_head); ld != NULL; 371 ld = LIST_NEXT(ld, ld_entries)) { 372 if (strcmp(name, ld->ld_name) == 0) 373 return (mac_prepare(mac, ld->ld_labels)); 374 } 375 376 errno = ENOENT; 377 return (-1); /* XXXMAC: ENOLABEL */ 378 } 379 380 int 381 mac_prepare_ifnet_label(struct mac **mac) 382 { 383 384 return (mac_prepare_type(mac, "ifnet")); 385 } 386 387 int 388 mac_prepare_file_label(struct mac **mac) 389 { 390 391 return (mac_prepare_type(mac, "file")); 392 } 393 394 int 395 mac_prepare_packet_label(struct mac **mac) 396 { 397 398 return (mac_prepare_type(mac, "packet")); 399 } 400 401 int 402 mac_prepare_process_label(struct mac **mac) 403 { 404 405 return (mac_prepare_type(mac, "process")); 406 } 407 408 /* 409 * Simply test whether the TrustedBSD/MAC MIB tree is present; if so, 410 * return 1 to indicate that the system has MAC enabled overall or for 411 * a given policy. 412 */ 413 int 414 mac_is_present(const char *policyname) 415 { 416 int mib[5]; 417 size_t siz; 418 char *mibname; 419 int error; 420 421 if (policyname != NULL) { 422 if (policyname[strcspn(policyname, ".=")] != '\0') { 423 errno = EINVAL; 424 return (-1); 425 } 426 mibname = malloc(sizeof("security.mac.") - 1 + 427 strlen(policyname) + sizeof(".enabled")); 428 if (mibname == NULL) 429 return (-1); 430 strcpy(mibname, "security.mac."); 431 strcat(mibname, policyname); 432 strcat(mibname, ".enabled"); 433 siz = 5; 434 error = sysctlnametomib(mibname, mib, &siz); 435 free(mibname); 436 } else { 437 siz = 3; 438 error = sysctlnametomib("security.mac", mib, &siz); 439 } 440 if (error == -1) { 441 switch (errno) { 442 case ENOTDIR: 443 case ENOENT: 444 return (0); 445 default: 446 return (error); 447 } 448 } 449 return (1); 450 } 451