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