Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame^] | 1 | /* |
| 2 | * Implementation of the access vector table type. |
| 3 | * |
| 4 | * Author : Stephen Smalley, <sds@epoch.ncsc.mil> |
| 5 | */ |
| 6 | |
| 7 | /* Updated: Frank Mayer <mayerf@tresys.com> and Karl MacMillan <kmacmillan@tresys.com> |
| 8 | * |
| 9 | * Added conditional policy language extensions |
| 10 | * |
| 11 | * Copyright (C) 2003 Tresys Technology, LLC |
| 12 | * This program is free software; you can redistribute it and/or modify |
| 13 | * it under the terms of the GNU General Public License as published by |
| 14 | * the Free Software Foundation, version 2. |
| 15 | */ |
| 16 | |
| 17 | #include <linux/kernel.h> |
| 18 | #include <linux/slab.h> |
| 19 | #include <linux/vmalloc.h> |
| 20 | #include <linux/errno.h> |
| 21 | |
| 22 | #include "avtab.h" |
| 23 | #include "policydb.h" |
| 24 | |
| 25 | #define AVTAB_HASH(keyp) \ |
| 26 | ((keyp->target_class + \ |
| 27 | (keyp->target_type << 2) + \ |
| 28 | (keyp->source_type << 9)) & \ |
| 29 | AVTAB_HASH_MASK) |
| 30 | |
| 31 | static kmem_cache_t *avtab_node_cachep; |
| 32 | |
| 33 | static struct avtab_node* |
| 34 | avtab_insert_node(struct avtab *h, int hvalue, |
| 35 | struct avtab_node * prev, struct avtab_node * cur, |
| 36 | struct avtab_key *key, struct avtab_datum *datum) |
| 37 | { |
| 38 | struct avtab_node * newnode; |
| 39 | newnode = kmem_cache_alloc(avtab_node_cachep, SLAB_KERNEL); |
| 40 | if (newnode == NULL) |
| 41 | return NULL; |
| 42 | memset(newnode, 0, sizeof(struct avtab_node)); |
| 43 | newnode->key = *key; |
| 44 | newnode->datum = *datum; |
| 45 | if (prev) { |
| 46 | newnode->next = prev->next; |
| 47 | prev->next = newnode; |
| 48 | } else { |
| 49 | newnode->next = h->htable[hvalue]; |
| 50 | h->htable[hvalue] = newnode; |
| 51 | } |
| 52 | |
| 53 | h->nel++; |
| 54 | return newnode; |
| 55 | } |
| 56 | |
| 57 | static int avtab_insert(struct avtab *h, struct avtab_key *key, struct avtab_datum *datum) |
| 58 | { |
| 59 | int hvalue; |
| 60 | struct avtab_node *prev, *cur, *newnode; |
| 61 | |
| 62 | if (!h) |
| 63 | return -EINVAL; |
| 64 | |
| 65 | hvalue = AVTAB_HASH(key); |
| 66 | for (prev = NULL, cur = h->htable[hvalue]; |
| 67 | cur; |
| 68 | prev = cur, cur = cur->next) { |
| 69 | if (key->source_type == cur->key.source_type && |
| 70 | key->target_type == cur->key.target_type && |
| 71 | key->target_class == cur->key.target_class && |
| 72 | (datum->specified & cur->datum.specified)) |
| 73 | return -EEXIST; |
| 74 | if (key->source_type < cur->key.source_type) |
| 75 | break; |
| 76 | if (key->source_type == cur->key.source_type && |
| 77 | key->target_type < cur->key.target_type) |
| 78 | break; |
| 79 | if (key->source_type == cur->key.source_type && |
| 80 | key->target_type == cur->key.target_type && |
| 81 | key->target_class < cur->key.target_class) |
| 82 | break; |
| 83 | } |
| 84 | |
| 85 | newnode = avtab_insert_node(h, hvalue, prev, cur, key, datum); |
| 86 | if(!newnode) |
| 87 | return -ENOMEM; |
| 88 | |
| 89 | return 0; |
| 90 | } |
| 91 | |
| 92 | /* Unlike avtab_insert(), this function allow multiple insertions of the same |
| 93 | * key/specified mask into the table, as needed by the conditional avtab. |
| 94 | * It also returns a pointer to the node inserted. |
| 95 | */ |
| 96 | struct avtab_node * |
| 97 | avtab_insert_nonunique(struct avtab * h, struct avtab_key * key, struct avtab_datum * datum) |
| 98 | { |
| 99 | int hvalue; |
| 100 | struct avtab_node *prev, *cur, *newnode; |
| 101 | |
| 102 | if (!h) |
| 103 | return NULL; |
| 104 | hvalue = AVTAB_HASH(key); |
| 105 | for (prev = NULL, cur = h->htable[hvalue]; |
| 106 | cur; |
| 107 | prev = cur, cur = cur->next) { |
| 108 | if (key->source_type == cur->key.source_type && |
| 109 | key->target_type == cur->key.target_type && |
| 110 | key->target_class == cur->key.target_class && |
| 111 | (datum->specified & cur->datum.specified)) |
| 112 | break; |
| 113 | if (key->source_type < cur->key.source_type) |
| 114 | break; |
| 115 | if (key->source_type == cur->key.source_type && |
| 116 | key->target_type < cur->key.target_type) |
| 117 | break; |
| 118 | if (key->source_type == cur->key.source_type && |
| 119 | key->target_type == cur->key.target_type && |
| 120 | key->target_class < cur->key.target_class) |
| 121 | break; |
| 122 | } |
| 123 | newnode = avtab_insert_node(h, hvalue, prev, cur, key, datum); |
| 124 | |
| 125 | return newnode; |
| 126 | } |
| 127 | |
| 128 | struct avtab_datum *avtab_search(struct avtab *h, struct avtab_key *key, int specified) |
| 129 | { |
| 130 | int hvalue; |
| 131 | struct avtab_node *cur; |
| 132 | |
| 133 | if (!h) |
| 134 | return NULL; |
| 135 | |
| 136 | hvalue = AVTAB_HASH(key); |
| 137 | for (cur = h->htable[hvalue]; cur; cur = cur->next) { |
| 138 | if (key->source_type == cur->key.source_type && |
| 139 | key->target_type == cur->key.target_type && |
| 140 | key->target_class == cur->key.target_class && |
| 141 | (specified & cur->datum.specified)) |
| 142 | return &cur->datum; |
| 143 | |
| 144 | if (key->source_type < cur->key.source_type) |
| 145 | break; |
| 146 | if (key->source_type == cur->key.source_type && |
| 147 | key->target_type < cur->key.target_type) |
| 148 | break; |
| 149 | if (key->source_type == cur->key.source_type && |
| 150 | key->target_type == cur->key.target_type && |
| 151 | key->target_class < cur->key.target_class) |
| 152 | break; |
| 153 | } |
| 154 | |
| 155 | return NULL; |
| 156 | } |
| 157 | |
| 158 | /* This search function returns a node pointer, and can be used in |
| 159 | * conjunction with avtab_search_next_node() |
| 160 | */ |
| 161 | struct avtab_node* |
| 162 | avtab_search_node(struct avtab *h, struct avtab_key *key, int specified) |
| 163 | { |
| 164 | int hvalue; |
| 165 | struct avtab_node *cur; |
| 166 | |
| 167 | if (!h) |
| 168 | return NULL; |
| 169 | |
| 170 | hvalue = AVTAB_HASH(key); |
| 171 | for (cur = h->htable[hvalue]; cur; cur = cur->next) { |
| 172 | if (key->source_type == cur->key.source_type && |
| 173 | key->target_type == cur->key.target_type && |
| 174 | key->target_class == cur->key.target_class && |
| 175 | (specified & cur->datum.specified)) |
| 176 | return cur; |
| 177 | |
| 178 | if (key->source_type < cur->key.source_type) |
| 179 | break; |
| 180 | if (key->source_type == cur->key.source_type && |
| 181 | key->target_type < cur->key.target_type) |
| 182 | break; |
| 183 | if (key->source_type == cur->key.source_type && |
| 184 | key->target_type == cur->key.target_type && |
| 185 | key->target_class < cur->key.target_class) |
| 186 | break; |
| 187 | } |
| 188 | return NULL; |
| 189 | } |
| 190 | |
| 191 | struct avtab_node* |
| 192 | avtab_search_node_next(struct avtab_node *node, int specified) |
| 193 | { |
| 194 | struct avtab_node *cur; |
| 195 | |
| 196 | if (!node) |
| 197 | return NULL; |
| 198 | |
| 199 | for (cur = node->next; cur; cur = cur->next) { |
| 200 | if (node->key.source_type == cur->key.source_type && |
| 201 | node->key.target_type == cur->key.target_type && |
| 202 | node->key.target_class == cur->key.target_class && |
| 203 | (specified & cur->datum.specified)) |
| 204 | return cur; |
| 205 | |
| 206 | if (node->key.source_type < cur->key.source_type) |
| 207 | break; |
| 208 | if (node->key.source_type == cur->key.source_type && |
| 209 | node->key.target_type < cur->key.target_type) |
| 210 | break; |
| 211 | if (node->key.source_type == cur->key.source_type && |
| 212 | node->key.target_type == cur->key.target_type && |
| 213 | node->key.target_class < cur->key.target_class) |
| 214 | break; |
| 215 | } |
| 216 | return NULL; |
| 217 | } |
| 218 | |
| 219 | void avtab_destroy(struct avtab *h) |
| 220 | { |
| 221 | int i; |
| 222 | struct avtab_node *cur, *temp; |
| 223 | |
| 224 | if (!h || !h->htable) |
| 225 | return; |
| 226 | |
| 227 | for (i = 0; i < AVTAB_SIZE; i++) { |
| 228 | cur = h->htable[i]; |
| 229 | while (cur != NULL) { |
| 230 | temp = cur; |
| 231 | cur = cur->next; |
| 232 | kmem_cache_free(avtab_node_cachep, temp); |
| 233 | } |
| 234 | h->htable[i] = NULL; |
| 235 | } |
| 236 | vfree(h->htable); |
| 237 | h->htable = NULL; |
| 238 | } |
| 239 | |
| 240 | |
| 241 | int avtab_init(struct avtab *h) |
| 242 | { |
| 243 | int i; |
| 244 | |
| 245 | h->htable = vmalloc(sizeof(*(h->htable)) * AVTAB_SIZE); |
| 246 | if (!h->htable) |
| 247 | return -ENOMEM; |
| 248 | for (i = 0; i < AVTAB_SIZE; i++) |
| 249 | h->htable[i] = NULL; |
| 250 | h->nel = 0; |
| 251 | return 0; |
| 252 | } |
| 253 | |
| 254 | void avtab_hash_eval(struct avtab *h, char *tag) |
| 255 | { |
| 256 | int i, chain_len, slots_used, max_chain_len; |
| 257 | struct avtab_node *cur; |
| 258 | |
| 259 | slots_used = 0; |
| 260 | max_chain_len = 0; |
| 261 | for (i = 0; i < AVTAB_SIZE; i++) { |
| 262 | cur = h->htable[i]; |
| 263 | if (cur) { |
| 264 | slots_used++; |
| 265 | chain_len = 0; |
| 266 | while (cur) { |
| 267 | chain_len++; |
| 268 | cur = cur->next; |
| 269 | } |
| 270 | |
| 271 | if (chain_len > max_chain_len) |
| 272 | max_chain_len = chain_len; |
| 273 | } |
| 274 | } |
| 275 | |
| 276 | printk(KERN_INFO "%s: %d entries and %d/%d buckets used, longest " |
| 277 | "chain length %d\n", tag, h->nel, slots_used, AVTAB_SIZE, |
| 278 | max_chain_len); |
| 279 | } |
| 280 | |
| 281 | int avtab_read_item(void *fp, struct avtab_datum *avdatum, struct avtab_key *avkey) |
| 282 | { |
| 283 | u32 buf[7]; |
| 284 | u32 items, items2; |
| 285 | int rc; |
| 286 | |
| 287 | memset(avkey, 0, sizeof(struct avtab_key)); |
| 288 | memset(avdatum, 0, sizeof(struct avtab_datum)); |
| 289 | |
| 290 | rc = next_entry(buf, fp, sizeof(u32)); |
| 291 | if (rc < 0) { |
| 292 | printk(KERN_ERR "security: avtab: truncated entry\n"); |
| 293 | goto bad; |
| 294 | } |
| 295 | items2 = le32_to_cpu(buf[0]); |
| 296 | if (items2 > ARRAY_SIZE(buf)) { |
| 297 | printk(KERN_ERR "security: avtab: entry overflow\n"); |
| 298 | goto bad; |
| 299 | } |
| 300 | rc = next_entry(buf, fp, sizeof(u32)*items2); |
| 301 | if (rc < 0) { |
| 302 | printk(KERN_ERR "security: avtab: truncated entry\n"); |
| 303 | goto bad; |
| 304 | } |
| 305 | items = 0; |
| 306 | avkey->source_type = le32_to_cpu(buf[items++]); |
| 307 | avkey->target_type = le32_to_cpu(buf[items++]); |
| 308 | avkey->target_class = le32_to_cpu(buf[items++]); |
| 309 | avdatum->specified = le32_to_cpu(buf[items++]); |
| 310 | if (!(avdatum->specified & (AVTAB_AV | AVTAB_TYPE))) { |
| 311 | printk(KERN_ERR "security: avtab: null entry\n"); |
| 312 | goto bad; |
| 313 | } |
| 314 | if ((avdatum->specified & AVTAB_AV) && |
| 315 | (avdatum->specified & AVTAB_TYPE)) { |
| 316 | printk(KERN_ERR "security: avtab: entry has both access vectors and types\n"); |
| 317 | goto bad; |
| 318 | } |
| 319 | if (avdatum->specified & AVTAB_AV) { |
| 320 | if (avdatum->specified & AVTAB_ALLOWED) |
| 321 | avtab_allowed(avdatum) = le32_to_cpu(buf[items++]); |
| 322 | if (avdatum->specified & AVTAB_AUDITDENY) |
| 323 | avtab_auditdeny(avdatum) = le32_to_cpu(buf[items++]); |
| 324 | if (avdatum->specified & AVTAB_AUDITALLOW) |
| 325 | avtab_auditallow(avdatum) = le32_to_cpu(buf[items++]); |
| 326 | } else { |
| 327 | if (avdatum->specified & AVTAB_TRANSITION) |
| 328 | avtab_transition(avdatum) = le32_to_cpu(buf[items++]); |
| 329 | if (avdatum->specified & AVTAB_CHANGE) |
| 330 | avtab_change(avdatum) = le32_to_cpu(buf[items++]); |
| 331 | if (avdatum->specified & AVTAB_MEMBER) |
| 332 | avtab_member(avdatum) = le32_to_cpu(buf[items++]); |
| 333 | } |
| 334 | if (items != items2) { |
| 335 | printk(KERN_ERR "security: avtab: entry only had %d items, expected %d\n", |
| 336 | items2, items); |
| 337 | goto bad; |
| 338 | } |
| 339 | |
| 340 | return 0; |
| 341 | bad: |
| 342 | return -1; |
| 343 | } |
| 344 | |
| 345 | int avtab_read(struct avtab *a, void *fp, u32 config) |
| 346 | { |
| 347 | int rc; |
| 348 | struct avtab_key avkey; |
| 349 | struct avtab_datum avdatum; |
| 350 | u32 buf[1]; |
| 351 | u32 nel, i; |
| 352 | |
| 353 | |
| 354 | rc = next_entry(buf, fp, sizeof(u32)); |
| 355 | if (rc < 0) { |
| 356 | printk(KERN_ERR "security: avtab: truncated table\n"); |
| 357 | goto bad; |
| 358 | } |
| 359 | nel = le32_to_cpu(buf[0]); |
| 360 | if (!nel) { |
| 361 | printk(KERN_ERR "security: avtab: table is empty\n"); |
| 362 | rc = -EINVAL; |
| 363 | goto bad; |
| 364 | } |
| 365 | for (i = 0; i < nel; i++) { |
| 366 | if (avtab_read_item(fp, &avdatum, &avkey)) { |
| 367 | rc = -EINVAL; |
| 368 | goto bad; |
| 369 | } |
| 370 | rc = avtab_insert(a, &avkey, &avdatum); |
| 371 | if (rc) { |
| 372 | if (rc == -ENOMEM) |
| 373 | printk(KERN_ERR "security: avtab: out of memory\n"); |
| 374 | if (rc == -EEXIST) |
| 375 | printk(KERN_ERR "security: avtab: duplicate entry\n"); |
| 376 | goto bad; |
| 377 | } |
| 378 | } |
| 379 | |
| 380 | rc = 0; |
| 381 | out: |
| 382 | return rc; |
| 383 | |
| 384 | bad: |
| 385 | avtab_destroy(a); |
| 386 | goto out; |
| 387 | } |
| 388 | |
| 389 | void avtab_cache_init(void) |
| 390 | { |
| 391 | avtab_node_cachep = kmem_cache_create("avtab_node", |
| 392 | sizeof(struct avtab_node), |
| 393 | 0, SLAB_PANIC, NULL, NULL); |
| 394 | } |
| 395 | |
| 396 | void avtab_cache_destroy(void) |
| 397 | { |
| 398 | kmem_cache_destroy (avtab_node_cachep); |
| 399 | } |