Joshua Brindle | 13cd4c8 | 2008-08-19 15:30:36 -0400 | [diff] [blame] | 1 | |
| 2 | /* Author : Stephen Smalley, <sds@epoch.ncsc.mil> */ |
| 3 | |
| 4 | /* |
| 5 | * Updated: Yuichi Nakamura <ynakam@hitachisoft.jp> |
| 6 | * Tuned number of hash slots for avtab to reduce memory usage |
| 7 | */ |
| 8 | |
| 9 | /* Updated: Frank Mayer <mayerf@tresys.com> |
| 10 | * and Karl MacMillan <kmacmillan@mentalrootkit.com> |
| 11 | * |
| 12 | * Added conditional policy language extensions |
| 13 | * |
| 14 | * Updated: Red Hat, Inc. James Morris <jmorris@redhat.com> |
| 15 | * |
| 16 | * Code cleanup |
| 17 | * |
| 18 | * Updated: Karl MacMillan <kmacmillan@mentalrootkit.com> |
| 19 | * |
| 20 | * Copyright (C) 2003 Tresys Technology, LLC |
| 21 | * Copyright (C) 2003,2007 Red Hat, Inc. |
| 22 | * |
| 23 | * This library is free software; you can redistribute it and/or |
| 24 | * modify it under the terms of the GNU Lesser General Public |
| 25 | * License as published by the Free Software Foundation; either |
| 26 | * version 2.1 of the License, or (at your option) any later version. |
| 27 | * |
| 28 | * This library is distributed in the hope that it will be useful, |
| 29 | * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 30 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
| 31 | * Lesser General Public License for more details. |
| 32 | * |
| 33 | * You should have received a copy of the GNU Lesser General Public |
| 34 | * License along with this library; if not, write to the Free Software |
| 35 | * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA |
| 36 | */ |
| 37 | |
| 38 | /* FLASK */ |
| 39 | |
| 40 | /* |
| 41 | * Implementation of the access vector table type. |
| 42 | */ |
| 43 | |
| 44 | #include <stdlib.h> |
| 45 | #include <sepol/policydb/avtab.h> |
| 46 | #include <sepol/policydb/policydb.h> |
| 47 | #include <sepol/errcodes.h> |
| 48 | |
| 49 | #include "debug.h" |
| 50 | #include "private.h" |
| 51 | |
| 52 | static inline int avtab_hash(struct avtab_key *keyp, uint16_t mask) |
| 53 | { |
| 54 | return ((keyp->target_class + (keyp->target_type << 2) + |
| 55 | (keyp->source_type << 9)) & mask); |
| 56 | } |
| 57 | |
| 58 | static avtab_ptr_t |
| 59 | avtab_insert_node(avtab_t * h, int hvalue, avtab_ptr_t prev, avtab_key_t * key, |
| 60 | avtab_datum_t * datum) |
| 61 | { |
| 62 | avtab_ptr_t newnode; |
| 63 | newnode = (avtab_ptr_t) malloc(sizeof(struct avtab_node)); |
| 64 | if (newnode == NULL) |
| 65 | return NULL; |
| 66 | memset(newnode, 0, sizeof(struct avtab_node)); |
| 67 | newnode->key = *key; |
| 68 | newnode->datum = *datum; |
| 69 | if (prev) { |
| 70 | newnode->next = prev->next; |
| 71 | prev->next = newnode; |
| 72 | } else { |
| 73 | newnode->next = h->htable[hvalue]; |
| 74 | h->htable[hvalue] = newnode; |
| 75 | } |
| 76 | |
| 77 | h->nel++; |
| 78 | return newnode; |
| 79 | } |
| 80 | |
| 81 | int avtab_insert(avtab_t * h, avtab_key_t * key, avtab_datum_t * datum) |
| 82 | { |
| 83 | int hvalue; |
| 84 | avtab_ptr_t prev, cur, newnode; |
| 85 | uint16_t specified = |
| 86 | key->specified & ~(AVTAB_ENABLED | AVTAB_ENABLED_OLD); |
| 87 | |
| 88 | if (!h || !h->htable) |
| 89 | return SEPOL_ENOMEM; |
| 90 | |
| 91 | hvalue = avtab_hash(key, h->mask); |
| 92 | for (prev = NULL, cur = h->htable[hvalue]; |
| 93 | cur; prev = cur, cur = cur->next) { |
| 94 | if (key->source_type == cur->key.source_type && |
| 95 | key->target_type == cur->key.target_type && |
| 96 | key->target_class == cur->key.target_class && |
| 97 | (specified & cur->key.specified)) |
| 98 | return SEPOL_EEXIST; |
| 99 | if (key->source_type < cur->key.source_type) |
| 100 | break; |
| 101 | if (key->source_type == cur->key.source_type && |
| 102 | key->target_type < cur->key.target_type) |
| 103 | break; |
| 104 | if (key->source_type == cur->key.source_type && |
| 105 | key->target_type == cur->key.target_type && |
| 106 | key->target_class < cur->key.target_class) |
| 107 | break; |
| 108 | } |
| 109 | |
| 110 | newnode = avtab_insert_node(h, hvalue, prev, key, datum); |
| 111 | if (!newnode) |
| 112 | return SEPOL_ENOMEM; |
| 113 | |
| 114 | return 0; |
| 115 | } |
| 116 | |
| 117 | /* Unlike avtab_insert(), this function allow multiple insertions of the same |
| 118 | * key/specified mask into the table, as needed by the conditional avtab. |
| 119 | * It also returns a pointer to the node inserted. |
| 120 | */ |
| 121 | avtab_ptr_t |
| 122 | avtab_insert_nonunique(avtab_t * h, avtab_key_t * key, avtab_datum_t * datum) |
| 123 | { |
| 124 | int hvalue; |
| 125 | avtab_ptr_t prev, cur, newnode; |
| 126 | uint16_t specified = |
| 127 | key->specified & ~(AVTAB_ENABLED | AVTAB_ENABLED_OLD); |
| 128 | |
| 129 | if (!h || !h->htable) |
| 130 | return NULL; |
| 131 | hvalue = avtab_hash(key, h->mask); |
| 132 | for (prev = NULL, cur = h->htable[hvalue]; |
| 133 | cur; prev = cur, cur = cur->next) { |
| 134 | if (key->source_type == cur->key.source_type && |
| 135 | key->target_type == cur->key.target_type && |
| 136 | key->target_class == cur->key.target_class && |
| 137 | (specified & cur->key.specified)) |
| 138 | break; |
| 139 | if (key->source_type < cur->key.source_type) |
| 140 | break; |
| 141 | if (key->source_type == cur->key.source_type && |
| 142 | key->target_type < cur->key.target_type) |
| 143 | break; |
| 144 | if (key->source_type == cur->key.source_type && |
| 145 | key->target_type == cur->key.target_type && |
| 146 | key->target_class < cur->key.target_class) |
| 147 | break; |
| 148 | } |
| 149 | newnode = avtab_insert_node(h, hvalue, prev, key, datum); |
| 150 | |
| 151 | return newnode; |
| 152 | } |
| 153 | |
| 154 | avtab_datum_t *avtab_search(avtab_t * h, avtab_key_t * key) |
| 155 | { |
| 156 | int hvalue; |
| 157 | avtab_ptr_t cur; |
| 158 | uint16_t specified = |
| 159 | key->specified & ~(AVTAB_ENABLED | AVTAB_ENABLED_OLD); |
| 160 | |
| 161 | if (!h || !h->htable) |
| 162 | return NULL; |
| 163 | |
| 164 | hvalue = avtab_hash(key, h->mask); |
| 165 | for (cur = h->htable[hvalue]; cur; cur = cur->next) { |
| 166 | if (key->source_type == cur->key.source_type && |
| 167 | key->target_type == cur->key.target_type && |
| 168 | key->target_class == cur->key.target_class && |
| 169 | (specified & cur->key.specified)) |
| 170 | return &cur->datum; |
| 171 | |
| 172 | if (key->source_type < cur->key.source_type) |
| 173 | break; |
| 174 | if (key->source_type == cur->key.source_type && |
| 175 | key->target_type < cur->key.target_type) |
| 176 | break; |
| 177 | if (key->source_type == cur->key.source_type && |
| 178 | key->target_type == cur->key.target_type && |
| 179 | key->target_class < cur->key.target_class) |
| 180 | break; |
| 181 | } |
| 182 | |
| 183 | return NULL; |
| 184 | } |
| 185 | |
| 186 | /* This search function returns a node pointer, and can be used in |
| 187 | * conjunction with avtab_search_next_node() |
| 188 | */ |
| 189 | avtab_ptr_t avtab_search_node(avtab_t * h, avtab_key_t * key) |
| 190 | { |
| 191 | int hvalue; |
| 192 | avtab_ptr_t cur; |
| 193 | uint16_t specified = |
| 194 | key->specified & ~(AVTAB_ENABLED | AVTAB_ENABLED_OLD); |
| 195 | |
| 196 | if (!h || !h->htable) |
| 197 | return NULL; |
| 198 | |
| 199 | hvalue = avtab_hash(key, h->mask); |
| 200 | for (cur = h->htable[hvalue]; cur; cur = cur->next) { |
| 201 | if (key->source_type == cur->key.source_type && |
| 202 | key->target_type == cur->key.target_type && |
| 203 | key->target_class == cur->key.target_class && |
| 204 | (specified & cur->key.specified)) |
| 205 | return cur; |
| 206 | |
| 207 | if (key->source_type < cur->key.source_type) |
| 208 | break; |
| 209 | if (key->source_type == cur->key.source_type && |
| 210 | key->target_type < cur->key.target_type) |
| 211 | break; |
| 212 | if (key->source_type == cur->key.source_type && |
| 213 | key->target_type == cur->key.target_type && |
| 214 | key->target_class < cur->key.target_class) |
| 215 | break; |
| 216 | } |
| 217 | return NULL; |
| 218 | } |
| 219 | |
| 220 | avtab_ptr_t avtab_search_node_next(avtab_ptr_t node, int specified) |
| 221 | { |
| 222 | avtab_ptr_t cur; |
| 223 | |
| 224 | if (!node) |
| 225 | return NULL; |
| 226 | |
| 227 | specified &= ~(AVTAB_ENABLED | AVTAB_ENABLED_OLD); |
| 228 | for (cur = node->next; cur; cur = cur->next) { |
| 229 | if (node->key.source_type == cur->key.source_type && |
| 230 | node->key.target_type == cur->key.target_type && |
| 231 | node->key.target_class == cur->key.target_class && |
| 232 | (specified & cur->key.specified)) |
| 233 | return cur; |
| 234 | |
| 235 | if (node->key.source_type < cur->key.source_type) |
| 236 | break; |
| 237 | if (node->key.source_type == cur->key.source_type && |
| 238 | node->key.target_type < cur->key.target_type) |
| 239 | break; |
| 240 | if (node->key.source_type == cur->key.source_type && |
| 241 | node->key.target_type == cur->key.target_type && |
| 242 | node->key.target_class < cur->key.target_class) |
| 243 | break; |
| 244 | } |
| 245 | return NULL; |
| 246 | } |
| 247 | |
| 248 | void avtab_destroy(avtab_t * h) |
| 249 | { |
| 250 | unsigned int i; |
| 251 | avtab_ptr_t cur, temp; |
| 252 | |
| 253 | if (!h || !h->htable) |
| 254 | return; |
| 255 | |
| 256 | for (i = 0; i < h->nslot; i++) { |
| 257 | cur = h->htable[i]; |
| 258 | while (cur != NULL) { |
| 259 | temp = cur; |
| 260 | cur = cur->next; |
| 261 | free(temp); |
| 262 | } |
| 263 | h->htable[i] = NULL; |
| 264 | } |
| 265 | free(h->htable); |
| 266 | h->htable = NULL; |
| 267 | h->nslot = 0; |
| 268 | h->mask = 0; |
| 269 | } |
| 270 | |
| 271 | int avtab_map(avtab_t * h, |
| 272 | int (*apply) (avtab_key_t * k, |
| 273 | avtab_datum_t * d, void *args), void *args) |
| 274 | { |
| 275 | unsigned int i; |
| 276 | int ret; |
| 277 | avtab_ptr_t cur; |
| 278 | |
| 279 | if (!h) |
| 280 | return 0; |
| 281 | |
| 282 | for (i = 0; i < h->nslot; i++) { |
| 283 | cur = h->htable[i]; |
| 284 | while (cur != NULL) { |
| 285 | ret = apply(&cur->key, &cur->datum, args); |
| 286 | if (ret) |
| 287 | return ret; |
| 288 | cur = cur->next; |
| 289 | } |
| 290 | } |
| 291 | return 0; |
| 292 | } |
| 293 | |
| 294 | int avtab_init(avtab_t * h) |
| 295 | { |
| 296 | h->htable = NULL; |
| 297 | h->nel = 0; |
| 298 | return 0; |
| 299 | } |
| 300 | |
| 301 | int avtab_alloc(avtab_t *h, uint32_t nrules) |
| 302 | { |
| 303 | uint16_t mask = 0; |
| 304 | uint32_t shift = 0; |
| 305 | uint32_t work = nrules; |
| 306 | uint32_t nslot = 0; |
| 307 | |
| 308 | if (nrules == 0) |
| 309 | goto out; |
| 310 | |
| 311 | while (work) { |
| 312 | work = work >> 1; |
| 313 | shift++; |
| 314 | } |
| 315 | if (shift > 2) |
| 316 | shift = shift - 2; |
| 317 | nslot = 1 << shift; |
| 318 | if (nslot > MAX_AVTAB_SIZE) |
| 319 | nslot = MAX_AVTAB_SIZE; |
| 320 | mask = nslot - 1; |
| 321 | |
| 322 | h->htable = calloc(nslot, sizeof(avtab_ptr_t)); |
| 323 | if (!h->htable) |
| 324 | return -1; |
| 325 | out: |
| 326 | h->nel = 0; |
| 327 | h->nslot = nslot; |
| 328 | h->mask = mask; |
| 329 | return 0; |
| 330 | } |
| 331 | |
| 332 | void avtab_hash_eval(avtab_t * h, char *tag) |
| 333 | { |
| 334 | unsigned int i, chain_len, slots_used, max_chain_len; |
| 335 | avtab_ptr_t cur; |
| 336 | |
| 337 | slots_used = 0; |
| 338 | max_chain_len = 0; |
| 339 | for (i = 0; i < h->nslot; i++) { |
| 340 | cur = h->htable[i]; |
| 341 | if (cur) { |
| 342 | slots_used++; |
| 343 | chain_len = 0; |
| 344 | while (cur) { |
| 345 | chain_len++; |
| 346 | cur = cur->next; |
| 347 | } |
| 348 | |
| 349 | if (chain_len > max_chain_len) |
| 350 | max_chain_len = chain_len; |
| 351 | } |
| 352 | } |
| 353 | |
| 354 | printf |
| 355 | ("%s: %d entries and %d/%d buckets used, longest chain length %d\n", |
| 356 | tag, h->nel, slots_used, h->nslot, max_chain_len); |
| 357 | } |
| 358 | |
| 359 | /* Ordering of datums in the original avtab format in the policy file. */ |
| 360 | static uint16_t spec_order[] = { |
| 361 | AVTAB_ALLOWED, |
| 362 | AVTAB_AUDITDENY, |
| 363 | AVTAB_AUDITALLOW, |
| 364 | AVTAB_TRANSITION, |
| 365 | AVTAB_CHANGE, |
| 366 | AVTAB_MEMBER |
| 367 | }; |
| 368 | |
| 369 | int avtab_read_item(struct policy_file *fp, uint32_t vers, avtab_t * a, |
| 370 | int (*insertf) (avtab_t * a, avtab_key_t * k, |
| 371 | avtab_datum_t * d, void *p), void *p) |
| 372 | { |
| 373 | uint16_t buf16[4], enabled; |
| 374 | uint32_t buf32[7], items, items2, val; |
| 375 | avtab_key_t key; |
| 376 | avtab_datum_t datum; |
| 377 | unsigned set; |
| 378 | unsigned int i; |
| 379 | int rc; |
| 380 | |
| 381 | memset(&key, 0, sizeof(avtab_key_t)); |
| 382 | memset(&datum, 0, sizeof(avtab_datum_t)); |
| 383 | |
| 384 | if (vers < POLICYDB_VERSION_AVTAB) { |
| 385 | rc = next_entry(buf32, fp, sizeof(uint32_t)); |
| 386 | if (rc < 0) { |
| 387 | ERR(fp->handle, "truncated entry"); |
| 388 | return -1; |
| 389 | } |
| 390 | items2 = le32_to_cpu(buf32[0]); |
| 391 | |
| 392 | if (items2 < 5 || items2 > ARRAY_SIZE(buf32)) { |
| 393 | ERR(fp->handle, "invalid item count"); |
| 394 | return -1; |
| 395 | } |
| 396 | |
| 397 | rc = next_entry(buf32, fp, sizeof(uint32_t) * items2); |
| 398 | if (rc < 0) { |
| 399 | ERR(fp->handle, "truncated entry"); |
| 400 | return -1; |
| 401 | } |
| 402 | |
| 403 | items = 0; |
| 404 | val = le32_to_cpu(buf32[items++]); |
| 405 | key.source_type = (uint16_t) val; |
| 406 | if (key.source_type != val) { |
| 407 | ERR(fp->handle, "truncated source type"); |
| 408 | return -1; |
| 409 | } |
| 410 | val = le32_to_cpu(buf32[items++]); |
| 411 | key.target_type = (uint16_t) val; |
| 412 | if (key.target_type != val) { |
| 413 | ERR(fp->handle, "truncated target type"); |
| 414 | return -1; |
| 415 | } |
| 416 | val = le32_to_cpu(buf32[items++]); |
| 417 | key.target_class = (uint16_t) val; |
| 418 | if (key.target_class != val) { |
| 419 | ERR(fp->handle, "truncated target class"); |
| 420 | return -1; |
| 421 | } |
| 422 | |
| 423 | val = le32_to_cpu(buf32[items++]); |
| 424 | enabled = (val & AVTAB_ENABLED_OLD) ? AVTAB_ENABLED : 0; |
| 425 | |
| 426 | if (!(val & (AVTAB_AV | AVTAB_TYPE))) { |
| 427 | ERR(fp->handle, "null entry"); |
| 428 | return -1; |
| 429 | } |
| 430 | if ((val & AVTAB_AV) && (val & AVTAB_TYPE)) { |
| 431 | ERR(fp->handle, "entry has both access " |
| 432 | "vectors and types"); |
| 433 | return -1; |
| 434 | } |
| 435 | |
| 436 | for (i = 0; i < ARRAY_SIZE(spec_order); i++) { |
| 437 | if (val & spec_order[i]) { |
| 438 | key.specified = spec_order[i] | enabled; |
| 439 | datum.data = le32_to_cpu(buf32[items++]); |
| 440 | rc = insertf(a, &key, &datum, p); |
| 441 | if (rc) |
| 442 | return rc; |
| 443 | } |
| 444 | } |
| 445 | |
| 446 | if (items != items2) { |
| 447 | ERR(fp->handle, "entry only had %d items, " |
| 448 | "expected %d", items2, items); |
| 449 | return -1; |
| 450 | } |
| 451 | return 0; |
| 452 | } |
| 453 | |
| 454 | rc = next_entry(buf16, fp, sizeof(uint16_t) * 4); |
| 455 | if (rc < 0) { |
| 456 | ERR(fp->handle, "truncated entry"); |
| 457 | return -1; |
| 458 | } |
| 459 | items = 0; |
| 460 | key.source_type = le16_to_cpu(buf16[items++]); |
| 461 | key.target_type = le16_to_cpu(buf16[items++]); |
| 462 | key.target_class = le16_to_cpu(buf16[items++]); |
| 463 | key.specified = le16_to_cpu(buf16[items++]); |
| 464 | |
| 465 | set = 0; |
| 466 | for (i = 0; i < ARRAY_SIZE(spec_order); i++) { |
| 467 | if (key.specified & spec_order[i]) |
| 468 | set++; |
| 469 | } |
| 470 | if (!set || set > 1) { |
| 471 | ERR(fp->handle, "more than one specifier"); |
| 472 | return -1; |
| 473 | } |
| 474 | |
| 475 | rc = next_entry(buf32, fp, sizeof(uint32_t)); |
| 476 | if (rc < 0) { |
| 477 | ERR(fp->handle, "truncated entry"); |
| 478 | return -1; |
| 479 | } |
| 480 | datum.data = le32_to_cpu(*buf32); |
| 481 | return insertf(a, &key, &datum, p); |
| 482 | } |
| 483 | |
| 484 | static int avtab_insertf(avtab_t * a, avtab_key_t * k, avtab_datum_t * d, |
| 485 | void *p __attribute__ ((unused))) |
| 486 | { |
| 487 | return avtab_insert(a, k, d); |
| 488 | } |
| 489 | |
| 490 | int avtab_read(avtab_t * a, struct policy_file *fp, uint32_t vers) |
| 491 | { |
| 492 | unsigned int i; |
| 493 | int rc; |
| 494 | uint32_t buf[1]; |
| 495 | uint32_t nel; |
| 496 | |
| 497 | rc = next_entry(buf, fp, sizeof(uint32_t)); |
| 498 | if (rc < 0) { |
| 499 | ERR(fp->handle, "truncated table"); |
| 500 | goto bad; |
| 501 | } |
| 502 | nel = le32_to_cpu(buf[0]); |
| 503 | if (!nel) { |
| 504 | ERR(fp->handle, "table is empty"); |
| 505 | goto bad; |
| 506 | } |
| 507 | |
| 508 | rc = avtab_alloc(a, nel); |
| 509 | if (rc) { |
| 510 | ERR(fp->handle, "out of memory"); |
| 511 | goto bad; |
| 512 | } |
| 513 | |
| 514 | for (i = 0; i < nel; i++) { |
| 515 | rc = avtab_read_item(fp, vers, a, avtab_insertf, NULL); |
| 516 | if (rc) { |
| 517 | if (rc == SEPOL_ENOMEM) |
| 518 | ERR(fp->handle, "out of memory"); |
| 519 | if (rc == SEPOL_EEXIST) |
| 520 | ERR(fp->handle, "duplicate entry"); |
| 521 | ERR(fp->handle, "failed on entry %d of %u", i, nel); |
| 522 | goto bad; |
| 523 | } |
| 524 | } |
| 525 | |
| 526 | return 0; |
| 527 | |
| 528 | bad: |
| 529 | avtab_destroy(a); |
| 530 | return -1; |
| 531 | } |