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 * $FreeBSD$ 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 if (!issetugid() && getenv("MAC_CONFFILE") != NULL) 178 filename = getenv("MAC_CONFFILE"); 179 else 180 filename = MAC_CONFFILE; 181 file = fopen(filename, "r"); 182 if (file == NULL) 183 return (0); 184 185 while (fgets(line, LINE_MAX, file)) { 186 char *comment, *parse, *statement; 187 188 if (line[strlen(line)-1] == '\n') 189 line[strlen(line)-1] = '\0'; 190 else { 191 if (ignore_errors) 192 continue; 193 fclose(file); 194 error = EINVAL; 195 goto just_return; 196 } 197 198 /* Remove any comment. */ 199 comment = line; 200 parse = strsep(&comment, "#"); 201 202 /* Blank lines OK. */ 203 statement = next_token(&parse); 204 if (statement == NULL) 205 continue; 206 207 if (strcmp(statement, "default_labels") == 0) { 208 char *name, *labels; 209 210 name = next_token(&parse); 211 labels = next_token(&parse); 212 if (name == NULL || labels == NULL || 213 next_token(&parse) != NULL) { 214 if (ignore_errors) 215 continue; 216 error = EINVAL; 217 fclose(file); 218 goto just_return; 219 } 220 221 if (mac_add_type(name, labels) == -1) { 222 if (ignore_errors) 223 continue; 224 fclose(file); 225 goto just_return; 226 } 227 } else if (strcmp(statement, "default_ifnet_labels") == 0 || 228 strcmp(statement, "default_file_labels") == 0 || 229 strcmp(statement, "default_process_labels") == 0) { 230 char *labels, *type; 231 232 if (strcmp(statement, "default_ifnet_labels") == 0) 233 type = "ifnet"; 234 else if (strcmp(statement, "default_file_labels") == 0) 235 type = "file"; 236 else if (strcmp(statement, "default_process_labels") == 237 0) 238 type = "process"; 239 240 labels = next_token(&parse); 241 if (labels == NULL || next_token(&parse) != NULL) { 242 if (ignore_errors) 243 continue; 244 error = EINVAL; 245 fclose(file); 246 goto just_return; 247 } 248 249 if (mac_add_type(type, labels) == -1) { 250 if (ignore_errors) 251 continue; 252 fclose(file); 253 goto just_return; 254 } 255 } else { 256 if (ignore_errors) 257 continue; 258 fclose(file); 259 error = EINVAL; 260 goto just_return; 261 } 262 } 263 264 fclose(file); 265 266 internal_initialized = 1; 267 268 just_return: 269 if (error != 0) 270 mac_destroy_internal(); 271 return (error); 272 } 273 274 static int 275 mac_maybe_init_internal(void) 276 { 277 278 if (!internal_initialized) 279 return (mac_init_internal(1)); 280 else 281 return (0); 282 } 283 284 int 285 mac_reload(void) 286 { 287 288 if (internal_initialized) 289 mac_destroy_internal(); 290 return (mac_init_internal(0)); 291 } 292 293 int 294 mac_free(struct mac *mac) 295 { 296 297 if (mac->m_string != NULL) 298 free(mac->m_string); 299 free(mac); 300 301 return (0); 302 } 303 304 int 305 mac_from_text(struct mac **mac, const char *text) 306 { 307 308 *mac = (struct mac *) malloc(sizeof(**mac)); 309 if (*mac == NULL) 310 return (ENOMEM); 311 312 (*mac)->m_string = strdup(text); 313 if ((*mac)->m_string == NULL) { 314 free(*mac); 315 *mac = NULL; 316 return (ENOMEM); 317 } 318 319 (*mac)->m_buflen = strlen((*mac)->m_string)+1; 320 321 return (0); 322 } 323 324 int 325 mac_to_text(struct mac *mac, char **text) 326 { 327 328 *text = strdup(mac->m_string); 329 if (*text == NULL) 330 return (ENOMEM); 331 return (0); 332 } 333 334 int 335 mac_prepare(struct mac **mac, const char *elements) 336 { 337 338 if (strlen(elements) >= MAC_MAX_LABEL_BUF_LEN) 339 return (EINVAL); 340 341 *mac = (struct mac *) malloc(sizeof(**mac)); 342 if (*mac == NULL) 343 return (ENOMEM); 344 345 (*mac)->m_string = malloc(MAC_MAX_LABEL_BUF_LEN); 346 if ((*mac)->m_string == NULL) { 347 free(*mac); 348 *mac = NULL; 349 return (ENOMEM); 350 } 351 352 strcpy((*mac)->m_string, elements); 353 (*mac)->m_buflen = MAC_MAX_LABEL_BUF_LEN; 354 355 return (0); 356 } 357 358 int 359 mac_prepare_type(struct mac **mac, const char *name) 360 { 361 struct label_default *ld; 362 int error; 363 364 error = mac_maybe_init_internal(); 365 if (error != 0) 366 return (error); 367 368 for (ld = LIST_FIRST(&label_default_head); ld != NULL; 369 ld = LIST_NEXT(ld, ld_entries)) { 370 if (strcmp(name, ld->ld_name) == 0) 371 return (mac_prepare(mac, ld->ld_labels)); 372 } 373 374 errno = ENOENT; 375 return (-1); /* XXXMAC: ENOLABEL */ 376 } 377 378 int 379 mac_prepare_ifnet_label(struct mac **mac) 380 { 381 382 return (mac_prepare_type(mac, "ifnet")); 383 } 384 385 int 386 mac_prepare_file_label(struct mac **mac) 387 { 388 389 return (mac_prepare_type(mac, "file")); 390 } 391 392 int 393 mac_prepare_packet_label(struct mac **mac) 394 { 395 396 return (mac_prepare_type(mac, "packet")); 397 } 398 399 int 400 mac_prepare_process_label(struct mac **mac) 401 { 402 403 return (mac_prepare_type(mac, "process")); 404 } 405 406 /* 407 * Simply test whether the TrustedBSD/MAC MIB tree is present; if so, 408 * return 1 to indicate that the system has MAC enabled overall or for 409 * a given policy. 410 */ 411 int 412 mac_is_present(const char *policyname) 413 { 414 int mib[5]; 415 size_t siz; 416 char *mibname; 417 int error; 418 419 if (policyname != NULL) { 420 if (policyname[strcspn(policyname, ".=")] != '\0') { 421 errno = EINVAL; 422 return (-1); 423 } 424 mibname = malloc(sizeof("security.mac.") - 1 + 425 strlen(policyname) + sizeof(".enabled")); 426 if (mibname == NULL) 427 return (-1); 428 strcpy(mibname, "security.mac."); 429 strcat(mibname, policyname); 430 strcat(mibname, ".enabled"); 431 siz = 5; 432 error = sysctlnametomib(mibname, mib, &siz); 433 free(mibname); 434 } else { 435 siz = 3; 436 error = sysctlnametomib("security.mac", mib, &siz); 437 } 438 if (error == -1) { 439 switch (errno) { 440 case ENOTDIR: 441 case ENOENT: 442 return (0); 443 default: 444 return (error); 445 } 446 } 447 return (1); 448 } 449