1 /*- 2 * SPDX-License-Identifier: BSD-2-Clause 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/types.h> 38 #include <sys/queue.h> 39 #include <sys/sysctl.h> 40 41 #include <dlfcn.h> 42 #include <errno.h> 43 #include <limits.h> 44 #include <stdio.h> 45 #include <stdlib.h> 46 #include <string.h> 47 #include <unistd.h> 48 49 #include <sys/mac.h> 50 51 static int internal_initialized; 52 53 /* 54 * Maintain a list of default label preparations for various object 55 * types. Each name will appear only once in the list. 56 * 57 * XXXMAC: Not thread-safe. 58 */ 59 static LIST_HEAD(, label_default) label_default_head; 60 struct label_default { 61 char *ld_name; 62 char *ld_labels; 63 LIST_ENTRY(label_default) ld_entries; 64 }; 65 66 static void 67 mac_destroy_labels(void) 68 { 69 struct label_default *ld; 70 71 while ((ld = LIST_FIRST(&label_default_head))) { 72 free(ld->ld_name); 73 free(ld->ld_labels); 74 LIST_REMOVE(ld, ld_entries); 75 free(ld); 76 } 77 } 78 79 static void 80 mac_destroy_internal(void) 81 { 82 83 mac_destroy_labels(); 84 85 internal_initialized = 0; 86 } 87 88 static int 89 mac_add_type(const char *name, const char *labels) 90 { 91 struct label_default *ld, *ld_new; 92 char *name_dup, *labels_dup; 93 94 /* 95 * Speculatively allocate all the memory now to avoid allocating 96 * later when we will someday hold a mutex. 97 */ 98 name_dup = strdup(name); 99 if (name_dup == NULL) { 100 errno = ENOMEM; 101 return (-1); 102 } 103 labels_dup = strdup(labels); 104 if (labels_dup == NULL) { 105 free(name_dup); 106 errno = ENOMEM; 107 return (-1); 108 } 109 ld_new = malloc(sizeof(*ld)); 110 if (ld_new == NULL) { 111 free(name_dup); 112 free(labels_dup); 113 errno = ENOMEM; 114 return (-1); 115 } 116 117 /* 118 * If the type is already present, replace the current entry 119 * rather than add a new instance. 120 */ 121 for (ld = LIST_FIRST(&label_default_head); ld != NULL; 122 ld = LIST_NEXT(ld, ld_entries)) { 123 if (strcmp(name, ld->ld_name) == 0) 124 break; 125 } 126 127 if (ld != NULL) { 128 free(ld->ld_labels); 129 ld->ld_labels = labels_dup; 130 labels_dup = NULL; 131 } else { 132 ld = ld_new; 133 ld->ld_name = name_dup; 134 ld->ld_labels = labels_dup; 135 136 ld_new = NULL; 137 name_dup = NULL; 138 labels_dup = NULL; 139 140 LIST_INSERT_HEAD(&label_default_head, ld, ld_entries); 141 } 142 143 if (name_dup != NULL) 144 free(name_dup); 145 if (labels_dup != NULL) 146 free(labels_dup); 147 if (ld_new != NULL) 148 free(ld_new); 149 150 return (0); 151 } 152 153 static char * 154 next_token(char **string) 155 { 156 char *token; 157 158 token = strsep(string, " \t"); 159 while (token != NULL && *token == '\0') 160 token = strsep(string, " \t"); 161 162 return (token); 163 } 164 165 static int 166 mac_init_internal(int ignore_errors) 167 { 168 const char *filename; 169 char line[LINE_MAX]; 170 FILE *file; 171 int error; 172 173 error = 0; 174 175 LIST_INIT(&label_default_head); 176 177 filename = secure_getenv("MAC_CONFFILE"); 178 if (filename == NULL) 179 filename = MAC_CONFFILE; 180 file = fopen(filename, "re"); 181 if (file == NULL) 182 return (0); 183 184 while (fgets(line, LINE_MAX, file)) { 185 char *comment, *parse, *statement; 186 187 if (line[strlen(line)-1] == '\n') 188 line[strlen(line)-1] = '\0'; 189 else { 190 if (ignore_errors) 191 continue; 192 fclose(file); 193 error = EINVAL; 194 goto just_return; 195 } 196 197 /* Remove any comment. */ 198 comment = line; 199 parse = strsep(&comment, "#"); 200 201 /* Blank lines OK. */ 202 statement = next_token(&parse); 203 if (statement == NULL) 204 continue; 205 206 if (strcmp(statement, "default_labels") == 0) { 207 char *name, *labels; 208 209 name = next_token(&parse); 210 labels = next_token(&parse); 211 if (name == NULL || labels == NULL || 212 next_token(&parse) != NULL) { 213 if (ignore_errors) 214 continue; 215 error = EINVAL; 216 fclose(file); 217 goto just_return; 218 } 219 220 if (mac_add_type(name, labels) == -1) { 221 if (ignore_errors) 222 continue; 223 fclose(file); 224 goto just_return; 225 } 226 } else if (strcmp(statement, "default_ifnet_labels") == 0 || 227 strcmp(statement, "default_file_labels") == 0 || 228 strcmp(statement, "default_process_labels") == 0) { 229 char *labels, *type; 230 231 if (strcmp(statement, "default_ifnet_labels") == 0) 232 type = "ifnet"; 233 else if (strcmp(statement, "default_file_labels") == 0) 234 type = "file"; 235 else if (strcmp(statement, "default_process_labels") == 236 0) 237 type = "process"; 238 239 labels = next_token(&parse); 240 if (labels == NULL || next_token(&parse) != NULL) { 241 if (ignore_errors) 242 continue; 243 error = EINVAL; 244 fclose(file); 245 goto just_return; 246 } 247 248 if (mac_add_type(type, labels) == -1) { 249 if (ignore_errors) 250 continue; 251 fclose(file); 252 goto just_return; 253 } 254 } else { 255 if (ignore_errors) 256 continue; 257 fclose(file); 258 error = EINVAL; 259 goto just_return; 260 } 261 } 262 263 fclose(file); 264 265 internal_initialized = 1; 266 267 just_return: 268 if (error != 0) 269 mac_destroy_internal(); 270 return (error); 271 } 272 273 static int 274 mac_maybe_init_internal(void) 275 { 276 277 if (!internal_initialized) 278 return (mac_init_internal(1)); 279 else 280 return (0); 281 } 282 283 int 284 mac_reload(void) 285 { 286 287 if (internal_initialized) 288 mac_destroy_internal(); 289 return (mac_init_internal(0)); 290 } 291 292 int 293 mac_free(struct mac *mac) 294 { 295 296 if (mac->m_string != NULL) 297 free(mac->m_string); 298 free(mac); 299 300 return (0); 301 } 302 303 int 304 mac_from_text(struct mac **mac, const char *text) 305 { 306 307 *mac = (struct mac *) malloc(sizeof(**mac)); 308 if (*mac == NULL) 309 return (ENOMEM); 310 311 (*mac)->m_string = strdup(text); 312 if ((*mac)->m_string == NULL) { 313 free(*mac); 314 *mac = NULL; 315 return (ENOMEM); 316 } 317 318 (*mac)->m_buflen = strlen((*mac)->m_string)+1; 319 320 return (0); 321 } 322 323 int 324 mac_to_text(struct mac *mac, char **text) 325 { 326 327 *text = strdup(mac->m_string); 328 if (*text == NULL) 329 return (ENOMEM); 330 return (0); 331 } 332 333 int 334 mac_prepare(struct mac **mac, const char *elements) 335 { 336 337 if (strlen(elements) >= MAC_MAX_LABEL_BUF_LEN) 338 return (EINVAL); 339 340 *mac = (struct mac *) malloc(sizeof(**mac)); 341 if (*mac == NULL) 342 return (ENOMEM); 343 344 (*mac)->m_string = malloc(MAC_MAX_LABEL_BUF_LEN); 345 if ((*mac)->m_string == NULL) { 346 free(*mac); 347 *mac = NULL; 348 return (ENOMEM); 349 } 350 351 strcpy((*mac)->m_string, elements); 352 (*mac)->m_buflen = MAC_MAX_LABEL_BUF_LEN; 353 354 return (0); 355 } 356 357 int 358 mac_prepare_type(struct mac **mac, const char *name) 359 { 360 struct label_default *ld; 361 int error; 362 363 error = mac_maybe_init_internal(); 364 if (error != 0) 365 return (error); 366 367 for (ld = LIST_FIRST(&label_default_head); ld != NULL; 368 ld = LIST_NEXT(ld, ld_entries)) { 369 if (strcmp(name, ld->ld_name) == 0) 370 return (mac_prepare(mac, ld->ld_labels)); 371 } 372 373 errno = ENOENT; 374 return (-1); /* XXXMAC: ENOLABEL */ 375 } 376 377 int 378 mac_prepare_ifnet_label(struct mac **mac) 379 { 380 381 return (mac_prepare_type(mac, "ifnet")); 382 } 383 384 int 385 mac_prepare_file_label(struct mac **mac) 386 { 387 388 return (mac_prepare_type(mac, "file")); 389 } 390 391 int 392 mac_prepare_packet_label(struct mac **mac) 393 { 394 395 return (mac_prepare_type(mac, "packet")); 396 } 397 398 int 399 mac_prepare_process_label(struct mac **mac) 400 { 401 402 return (mac_prepare_type(mac, "process")); 403 } 404 405 /* 406 * Simply test whether the TrustedBSD/MAC MIB tree is present; if so, 407 * return 1 to indicate that the system has MAC enabled overall or for 408 * a given policy. 409 */ 410 int 411 mac_is_present(const char *policyname) 412 { 413 int mib[5]; 414 size_t siz; 415 char *mibname; 416 int error; 417 418 if (policyname != NULL) { 419 if (policyname[strcspn(policyname, ".=")] != '\0') { 420 errno = EINVAL; 421 return (-1); 422 } 423 mibname = malloc(sizeof("security.mac.") - 1 + 424 strlen(policyname) + sizeof(".enabled")); 425 if (mibname == NULL) 426 return (-1); 427 strcpy(mibname, "security.mac."); 428 strcat(mibname, policyname); 429 strcat(mibname, ".enabled"); 430 siz = 5; 431 error = sysctlnametomib(mibname, mib, &siz); 432 free(mibname); 433 } else { 434 siz = 3; 435 error = sysctlnametomib("security.mac", mib, &siz); 436 } 437 if (error == -1) { 438 switch (errno) { 439 case ENOTDIR: 440 case ENOENT: 441 return (0); 442 default: 443 return (error); 444 } 445 } 446 return (1); 447 } 448