Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1 | /* |
| 2 | * Implementation of the kernel access vector cache (AVC). |
| 3 | * |
| 4 | * Authors: Stephen Smalley, <sds@epoch.ncsc.mil> |
| 5 | * James Morris <jmorris@redhat.com> |
| 6 | * |
| 7 | * Update: KaiGai, Kohei <kaigai@ak.jp.nec.com> |
| 8 | * Replaced the avc_lock spinlock by RCU. |
| 9 | * |
| 10 | * Copyright (C) 2003 Red Hat, Inc., James Morris <jmorris@redhat.com> |
| 11 | * |
| 12 | * This program is free software; you can redistribute it and/or modify |
| 13 | * it under the terms of the GNU General Public License version 2, |
| 14 | * as published by the Free Software Foundation. |
| 15 | */ |
| 16 | #include <linux/types.h> |
| 17 | #include <linux/stddef.h> |
| 18 | #include <linux/kernel.h> |
| 19 | #include <linux/slab.h> |
| 20 | #include <linux/fs.h> |
| 21 | #include <linux/dcache.h> |
| 22 | #include <linux/init.h> |
| 23 | #include <linux/skbuff.h> |
| 24 | #include <linux/percpu.h> |
| 25 | #include <net/sock.h> |
| 26 | #include <linux/un.h> |
| 27 | #include <net/af_unix.h> |
| 28 | #include <linux/ip.h> |
| 29 | #include <linux/audit.h> |
| 30 | #include <linux/ipv6.h> |
| 31 | #include <net/ipv6.h> |
| 32 | #include "avc.h" |
| 33 | #include "avc_ss.h" |
| 34 | |
Chad Sellers | 5c45899 | 2006-11-06 12:38:16 -0500 | [diff] [blame] | 35 | static const struct av_perm_to_string av_perm_to_string[] = { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 36 | #define S_(c, v, s) { c, v, s }, |
| 37 | #include "av_perm_to_string.h" |
| 38 | #undef S_ |
| 39 | }; |
| 40 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 41 | static const char *class_to_string[] = { |
| 42 | #define S_(s) s, |
| 43 | #include "class_to_string.h" |
| 44 | #undef S_ |
| 45 | }; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 46 | |
| 47 | #define TB_(s) static const char * s [] = { |
| 48 | #define TE_(s) }; |
| 49 | #define S_(s) s, |
| 50 | #include "common_perm_to_string.h" |
| 51 | #undef TB_ |
| 52 | #undef TE_ |
| 53 | #undef S_ |
| 54 | |
Chad Sellers | 5c45899 | 2006-11-06 12:38:16 -0500 | [diff] [blame] | 55 | static const struct av_inherit av_inherit[] = { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 56 | #define S_(c, i, b) { c, common_##i##_perm_to_string, b }, |
| 57 | #include "av_inherit.h" |
| 58 | #undef S_ |
| 59 | }; |
| 60 | |
Chad Sellers | 5c45899 | 2006-11-06 12:38:16 -0500 | [diff] [blame] | 61 | const struct selinux_class_perm selinux_class_perm = { |
| 62 | av_perm_to_string, |
| 63 | ARRAY_SIZE(av_perm_to_string), |
| 64 | class_to_string, |
| 65 | ARRAY_SIZE(class_to_string), |
| 66 | av_inherit, |
| 67 | ARRAY_SIZE(av_inherit) |
| 68 | }; |
| 69 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 70 | #define AVC_CACHE_SLOTS 512 |
| 71 | #define AVC_DEF_CACHE_THRESHOLD 512 |
| 72 | #define AVC_CACHE_RECLAIM 16 |
| 73 | |
| 74 | #ifdef CONFIG_SECURITY_SELINUX_AVC_STATS |
| 75 | #define avc_cache_stats_incr(field) \ |
| 76 | do { \ |
| 77 | per_cpu(avc_cache_stats, get_cpu()).field++; \ |
| 78 | put_cpu(); \ |
| 79 | } while (0) |
| 80 | #else |
| 81 | #define avc_cache_stats_incr(field) do {} while (0) |
| 82 | #endif |
| 83 | |
| 84 | struct avc_entry { |
| 85 | u32 ssid; |
| 86 | u32 tsid; |
| 87 | u16 tclass; |
| 88 | struct av_decision avd; |
| 89 | atomic_t used; /* used recently */ |
| 90 | }; |
| 91 | |
| 92 | struct avc_node { |
| 93 | struct avc_entry ae; |
| 94 | struct list_head list; |
| 95 | struct rcu_head rhead; |
| 96 | }; |
| 97 | |
| 98 | struct avc_cache { |
| 99 | struct list_head slots[AVC_CACHE_SLOTS]; |
| 100 | spinlock_t slots_lock[AVC_CACHE_SLOTS]; /* lock for writes */ |
| 101 | atomic_t lru_hint; /* LRU hint for reclaim scan */ |
| 102 | atomic_t active_nodes; |
| 103 | u32 latest_notif; /* latest revocation notification */ |
| 104 | }; |
| 105 | |
| 106 | struct avc_callback_node { |
| 107 | int (*callback) (u32 event, u32 ssid, u32 tsid, |
| 108 | u16 tclass, u32 perms, |
| 109 | u32 *out_retained); |
| 110 | u32 events; |
| 111 | u32 ssid; |
| 112 | u32 tsid; |
| 113 | u16 tclass; |
| 114 | u32 perms; |
| 115 | struct avc_callback_node *next; |
| 116 | }; |
| 117 | |
| 118 | /* Exported via selinufs */ |
| 119 | unsigned int avc_cache_threshold = AVC_DEF_CACHE_THRESHOLD; |
| 120 | |
| 121 | #ifdef CONFIG_SECURITY_SELINUX_AVC_STATS |
| 122 | DEFINE_PER_CPU(struct avc_cache_stats, avc_cache_stats) = { 0 }; |
| 123 | #endif |
| 124 | |
| 125 | static struct avc_cache avc_cache; |
| 126 | static struct avc_callback_node *avc_callbacks; |
Christoph Lameter | e18b890 | 2006-12-06 20:33:20 -0800 | [diff] [blame] | 127 | static struct kmem_cache *avc_node_cachep; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 128 | |
| 129 | static inline int avc_hash(u32 ssid, u32 tsid, u16 tclass) |
| 130 | { |
| 131 | return (ssid ^ (tsid<<2) ^ (tclass<<4)) & (AVC_CACHE_SLOTS - 1); |
| 132 | } |
| 133 | |
| 134 | /** |
| 135 | * avc_dump_av - Display an access vector in human-readable form. |
| 136 | * @tclass: target security class |
| 137 | * @av: access vector |
| 138 | */ |
| 139 | static void avc_dump_av(struct audit_buffer *ab, u16 tclass, u32 av) |
| 140 | { |
| 141 | const char **common_pts = NULL; |
| 142 | u32 common_base = 0; |
| 143 | int i, i2, perm; |
| 144 | |
| 145 | if (av == 0) { |
| 146 | audit_log_format(ab, " null"); |
| 147 | return; |
| 148 | } |
| 149 | |
| 150 | for (i = 0; i < ARRAY_SIZE(av_inherit); i++) { |
| 151 | if (av_inherit[i].tclass == tclass) { |
| 152 | common_pts = av_inherit[i].common_pts; |
| 153 | common_base = av_inherit[i].common_base; |
| 154 | break; |
| 155 | } |
| 156 | } |
| 157 | |
| 158 | audit_log_format(ab, " {"); |
| 159 | i = 0; |
| 160 | perm = 1; |
| 161 | while (perm < common_base) { |
| 162 | if (perm & av) { |
| 163 | audit_log_format(ab, " %s", common_pts[i]); |
| 164 | av &= ~perm; |
| 165 | } |
| 166 | i++; |
| 167 | perm <<= 1; |
| 168 | } |
| 169 | |
| 170 | while (i < sizeof(av) * 8) { |
| 171 | if (perm & av) { |
| 172 | for (i2 = 0; i2 < ARRAY_SIZE(av_perm_to_string); i2++) { |
| 173 | if ((av_perm_to_string[i2].tclass == tclass) && |
| 174 | (av_perm_to_string[i2].value == perm)) |
| 175 | break; |
| 176 | } |
| 177 | if (i2 < ARRAY_SIZE(av_perm_to_string)) { |
| 178 | audit_log_format(ab, " %s", |
| 179 | av_perm_to_string[i2].name); |
| 180 | av &= ~perm; |
| 181 | } |
| 182 | } |
| 183 | i++; |
| 184 | perm <<= 1; |
| 185 | } |
| 186 | |
| 187 | if (av) |
| 188 | audit_log_format(ab, " 0x%x", av); |
| 189 | |
| 190 | audit_log_format(ab, " }"); |
| 191 | } |
| 192 | |
| 193 | /** |
| 194 | * avc_dump_query - Display a SID pair and a class in human-readable form. |
| 195 | * @ssid: source security identifier |
| 196 | * @tsid: target security identifier |
| 197 | * @tclass: target security class |
| 198 | */ |
| 199 | static void avc_dump_query(struct audit_buffer *ab, u32 ssid, u32 tsid, u16 tclass) |
| 200 | { |
| 201 | int rc; |
| 202 | char *scontext; |
| 203 | u32 scontext_len; |
| 204 | |
| 205 | rc = security_sid_to_context(ssid, &scontext, &scontext_len); |
| 206 | if (rc) |
| 207 | audit_log_format(ab, "ssid=%d", ssid); |
| 208 | else { |
| 209 | audit_log_format(ab, "scontext=%s", scontext); |
| 210 | kfree(scontext); |
| 211 | } |
| 212 | |
| 213 | rc = security_sid_to_context(tsid, &scontext, &scontext_len); |
| 214 | if (rc) |
| 215 | audit_log_format(ab, " tsid=%d", tsid); |
| 216 | else { |
| 217 | audit_log_format(ab, " tcontext=%s", scontext); |
| 218 | kfree(scontext); |
| 219 | } |
Stephen Smalley | a764ae4 | 2007-03-26 13:36:26 -0400 | [diff] [blame] | 220 | |
| 221 | BUG_ON(tclass >= ARRAY_SIZE(class_to_string) || !class_to_string[tclass]); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 222 | audit_log_format(ab, " tclass=%s", class_to_string[tclass]); |
| 223 | } |
| 224 | |
| 225 | /** |
| 226 | * avc_init - Initialize the AVC. |
| 227 | * |
| 228 | * Initialize the access vector cache. |
| 229 | */ |
| 230 | void __init avc_init(void) |
| 231 | { |
| 232 | int i; |
| 233 | |
| 234 | for (i = 0; i < AVC_CACHE_SLOTS; i++) { |
| 235 | INIT_LIST_HEAD(&avc_cache.slots[i]); |
| 236 | spin_lock_init(&avc_cache.slots_lock[i]); |
| 237 | } |
| 238 | atomic_set(&avc_cache.active_nodes, 0); |
| 239 | atomic_set(&avc_cache.lru_hint, 0); |
| 240 | |
| 241 | avc_node_cachep = kmem_cache_create("avc_node", sizeof(struct avc_node), |
Paul Mundt | 20c2df8 | 2007-07-20 10:11:58 +0900 | [diff] [blame] | 242 | 0, SLAB_PANIC, NULL); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 243 | |
David Woodhouse | 9ad9ad3 | 2005-06-22 15:04:33 +0100 | [diff] [blame] | 244 | audit_log(current->audit_context, GFP_KERNEL, AUDIT_KERNEL, "AVC INITIALIZED\n"); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 245 | } |
| 246 | |
| 247 | int avc_get_hash_stats(char *page) |
| 248 | { |
| 249 | int i, chain_len, max_chain_len, slots_used; |
| 250 | struct avc_node *node; |
| 251 | |
| 252 | rcu_read_lock(); |
| 253 | |
| 254 | slots_used = 0; |
| 255 | max_chain_len = 0; |
| 256 | for (i = 0; i < AVC_CACHE_SLOTS; i++) { |
| 257 | if (!list_empty(&avc_cache.slots[i])) { |
| 258 | slots_used++; |
| 259 | chain_len = 0; |
| 260 | list_for_each_entry_rcu(node, &avc_cache.slots[i], list) |
| 261 | chain_len++; |
| 262 | if (chain_len > max_chain_len) |
| 263 | max_chain_len = chain_len; |
| 264 | } |
| 265 | } |
| 266 | |
| 267 | rcu_read_unlock(); |
| 268 | |
| 269 | return scnprintf(page, PAGE_SIZE, "entries: %d\nbuckets used: %d/%d\n" |
| 270 | "longest chain: %d\n", |
| 271 | atomic_read(&avc_cache.active_nodes), |
| 272 | slots_used, AVC_CACHE_SLOTS, max_chain_len); |
| 273 | } |
| 274 | |
| 275 | static void avc_node_free(struct rcu_head *rhead) |
| 276 | { |
| 277 | struct avc_node *node = container_of(rhead, struct avc_node, rhead); |
| 278 | kmem_cache_free(avc_node_cachep, node); |
| 279 | avc_cache_stats_incr(frees); |
| 280 | } |
| 281 | |
| 282 | static void avc_node_delete(struct avc_node *node) |
| 283 | { |
| 284 | list_del_rcu(&node->list); |
| 285 | call_rcu(&node->rhead, avc_node_free); |
| 286 | atomic_dec(&avc_cache.active_nodes); |
| 287 | } |
| 288 | |
| 289 | static void avc_node_kill(struct avc_node *node) |
| 290 | { |
| 291 | kmem_cache_free(avc_node_cachep, node); |
| 292 | avc_cache_stats_incr(frees); |
| 293 | atomic_dec(&avc_cache.active_nodes); |
| 294 | } |
| 295 | |
| 296 | static void avc_node_replace(struct avc_node *new, struct avc_node *old) |
| 297 | { |
| 298 | list_replace_rcu(&old->list, &new->list); |
| 299 | call_rcu(&old->rhead, avc_node_free); |
| 300 | atomic_dec(&avc_cache.active_nodes); |
| 301 | } |
| 302 | |
| 303 | static inline int avc_reclaim_node(void) |
| 304 | { |
| 305 | struct avc_node *node; |
| 306 | int hvalue, try, ecx; |
| 307 | unsigned long flags; |
| 308 | |
| 309 | for (try = 0, ecx = 0; try < AVC_CACHE_SLOTS; try++ ) { |
| 310 | hvalue = atomic_inc_return(&avc_cache.lru_hint) & (AVC_CACHE_SLOTS - 1); |
| 311 | |
| 312 | if (!spin_trylock_irqsave(&avc_cache.slots_lock[hvalue], flags)) |
| 313 | continue; |
| 314 | |
| 315 | list_for_each_entry(node, &avc_cache.slots[hvalue], list) { |
| 316 | if (atomic_dec_and_test(&node->ae.used)) { |
| 317 | /* Recently Unused */ |
| 318 | avc_node_delete(node); |
| 319 | avc_cache_stats_incr(reclaims); |
| 320 | ecx++; |
| 321 | if (ecx >= AVC_CACHE_RECLAIM) { |
| 322 | spin_unlock_irqrestore(&avc_cache.slots_lock[hvalue], flags); |
| 323 | goto out; |
| 324 | } |
| 325 | } |
| 326 | } |
| 327 | spin_unlock_irqrestore(&avc_cache.slots_lock[hvalue], flags); |
| 328 | } |
| 329 | out: |
| 330 | return ecx; |
| 331 | } |
| 332 | |
| 333 | static struct avc_node *avc_alloc_node(void) |
| 334 | { |
| 335 | struct avc_node *node; |
| 336 | |
Robert P. J. Day | c376222 | 2007-02-10 01:45:03 -0800 | [diff] [blame] | 337 | node = kmem_cache_zalloc(avc_node_cachep, GFP_ATOMIC); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 338 | if (!node) |
| 339 | goto out; |
| 340 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 341 | INIT_RCU_HEAD(&node->rhead); |
| 342 | INIT_LIST_HEAD(&node->list); |
| 343 | atomic_set(&node->ae.used, 1); |
| 344 | avc_cache_stats_incr(allocations); |
| 345 | |
| 346 | if (atomic_inc_return(&avc_cache.active_nodes) > avc_cache_threshold) |
| 347 | avc_reclaim_node(); |
| 348 | |
| 349 | out: |
| 350 | return node; |
| 351 | } |
| 352 | |
| 353 | static void avc_node_populate(struct avc_node *node, u32 ssid, u32 tsid, u16 tclass, struct avc_entry *ae) |
| 354 | { |
| 355 | node->ae.ssid = ssid; |
| 356 | node->ae.tsid = tsid; |
| 357 | node->ae.tclass = tclass; |
| 358 | memcpy(&node->ae.avd, &ae->avd, sizeof(node->ae.avd)); |
| 359 | } |
| 360 | |
| 361 | static inline struct avc_node *avc_search_node(u32 ssid, u32 tsid, u16 tclass) |
| 362 | { |
| 363 | struct avc_node *node, *ret = NULL; |
| 364 | int hvalue; |
| 365 | |
| 366 | hvalue = avc_hash(ssid, tsid, tclass); |
| 367 | list_for_each_entry_rcu(node, &avc_cache.slots[hvalue], list) { |
| 368 | if (ssid == node->ae.ssid && |
| 369 | tclass == node->ae.tclass && |
| 370 | tsid == node->ae.tsid) { |
| 371 | ret = node; |
| 372 | break; |
| 373 | } |
| 374 | } |
| 375 | |
| 376 | if (ret == NULL) { |
| 377 | /* cache miss */ |
| 378 | goto out; |
| 379 | } |
| 380 | |
| 381 | /* cache hit */ |
| 382 | if (atomic_read(&ret->ae.used) != 1) |
| 383 | atomic_set(&ret->ae.used, 1); |
| 384 | out: |
| 385 | return ret; |
| 386 | } |
| 387 | |
| 388 | /** |
| 389 | * avc_lookup - Look up an AVC entry. |
| 390 | * @ssid: source security identifier |
| 391 | * @tsid: target security identifier |
| 392 | * @tclass: target security class |
| 393 | * @requested: requested permissions, interpreted based on @tclass |
| 394 | * |
| 395 | * Look up an AVC entry that is valid for the |
| 396 | * @requested permissions between the SID pair |
| 397 | * (@ssid, @tsid), interpreting the permissions |
| 398 | * based on @tclass. If a valid AVC entry exists, |
| 399 | * then this function return the avc_node. |
| 400 | * Otherwise, this function returns NULL. |
| 401 | */ |
| 402 | static struct avc_node *avc_lookup(u32 ssid, u32 tsid, u16 tclass, u32 requested) |
| 403 | { |
| 404 | struct avc_node *node; |
| 405 | |
| 406 | avc_cache_stats_incr(lookups); |
| 407 | node = avc_search_node(ssid, tsid, tclass); |
| 408 | |
| 409 | if (node && ((node->ae.avd.decided & requested) == requested)) { |
| 410 | avc_cache_stats_incr(hits); |
| 411 | goto out; |
| 412 | } |
| 413 | |
| 414 | node = NULL; |
| 415 | avc_cache_stats_incr(misses); |
| 416 | out: |
| 417 | return node; |
| 418 | } |
| 419 | |
| 420 | static int avc_latest_notif_update(int seqno, int is_insert) |
| 421 | { |
| 422 | int ret = 0; |
| 423 | static DEFINE_SPINLOCK(notif_lock); |
| 424 | unsigned long flag; |
| 425 | |
| 426 | spin_lock_irqsave(¬if_lock, flag); |
| 427 | if (is_insert) { |
| 428 | if (seqno < avc_cache.latest_notif) { |
| 429 | printk(KERN_WARNING "avc: seqno %d < latest_notif %d\n", |
| 430 | seqno, avc_cache.latest_notif); |
| 431 | ret = -EAGAIN; |
| 432 | } |
| 433 | } else { |
| 434 | if (seqno > avc_cache.latest_notif) |
| 435 | avc_cache.latest_notif = seqno; |
| 436 | } |
| 437 | spin_unlock_irqrestore(¬if_lock, flag); |
| 438 | |
| 439 | return ret; |
| 440 | } |
| 441 | |
| 442 | /** |
| 443 | * avc_insert - Insert an AVC entry. |
| 444 | * @ssid: source security identifier |
| 445 | * @tsid: target security identifier |
| 446 | * @tclass: target security class |
| 447 | * @ae: AVC entry |
| 448 | * |
| 449 | * Insert an AVC entry for the SID pair |
| 450 | * (@ssid, @tsid) and class @tclass. |
| 451 | * The access vectors and the sequence number are |
| 452 | * normally provided by the security server in |
| 453 | * response to a security_compute_av() call. If the |
| 454 | * sequence number @ae->avd.seqno is not less than the latest |
| 455 | * revocation notification, then the function copies |
| 456 | * the access vectors into a cache entry, returns |
| 457 | * avc_node inserted. Otherwise, this function returns NULL. |
| 458 | */ |
| 459 | static struct avc_node *avc_insert(u32 ssid, u32 tsid, u16 tclass, struct avc_entry *ae) |
| 460 | { |
| 461 | struct avc_node *pos, *node = NULL; |
| 462 | int hvalue; |
| 463 | unsigned long flag; |
| 464 | |
| 465 | if (avc_latest_notif_update(ae->avd.seqno, 1)) |
| 466 | goto out; |
| 467 | |
| 468 | node = avc_alloc_node(); |
| 469 | if (node) { |
| 470 | hvalue = avc_hash(ssid, tsid, tclass); |
| 471 | avc_node_populate(node, ssid, tsid, tclass, ae); |
| 472 | |
| 473 | spin_lock_irqsave(&avc_cache.slots_lock[hvalue], flag); |
| 474 | list_for_each_entry(pos, &avc_cache.slots[hvalue], list) { |
| 475 | if (pos->ae.ssid == ssid && |
| 476 | pos->ae.tsid == tsid && |
| 477 | pos->ae.tclass == tclass) { |
| 478 | avc_node_replace(node, pos); |
| 479 | goto found; |
| 480 | } |
| 481 | } |
| 482 | list_add_rcu(&node->list, &avc_cache.slots[hvalue]); |
| 483 | found: |
| 484 | spin_unlock_irqrestore(&avc_cache.slots_lock[hvalue], flag); |
| 485 | } |
| 486 | out: |
| 487 | return node; |
| 488 | } |
| 489 | |
| 490 | static inline void avc_print_ipv6_addr(struct audit_buffer *ab, |
Alexey Dobriyan | b5bf6c5 | 2005-09-03 15:55:17 -0700 | [diff] [blame] | 491 | struct in6_addr *addr, __be16 port, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 492 | char *name1, char *name2) |
| 493 | { |
| 494 | if (!ipv6_addr_any(addr)) |
Joe Perches | 46b86a2 | 2006-01-13 14:29:07 -0800 | [diff] [blame] | 495 | audit_log_format(ab, " %s=" NIP6_FMT, name1, NIP6(*addr)); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 496 | if (port) |
| 497 | audit_log_format(ab, " %s=%d", name2, ntohs(port)); |
| 498 | } |
| 499 | |
Al Viro | 87fcd70 | 2006-12-04 22:00:55 +0000 | [diff] [blame] | 500 | static inline void avc_print_ipv4_addr(struct audit_buffer *ab, __be32 addr, |
Alexey Dobriyan | b5bf6c5 | 2005-09-03 15:55:17 -0700 | [diff] [blame] | 501 | __be16 port, char *name1, char *name2) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 502 | { |
| 503 | if (addr) |
Joe Perches | 46b86a2 | 2006-01-13 14:29:07 -0800 | [diff] [blame] | 504 | audit_log_format(ab, " %s=" NIPQUAD_FMT, name1, NIPQUAD(addr)); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 505 | if (port) |
| 506 | audit_log_format(ab, " %s=%d", name2, ntohs(port)); |
| 507 | } |
| 508 | |
| 509 | /** |
| 510 | * avc_audit - Audit the granting or denial of permissions. |
| 511 | * @ssid: source security identifier |
| 512 | * @tsid: target security identifier |
| 513 | * @tclass: target security class |
| 514 | * @requested: requested permissions |
| 515 | * @avd: access vector decisions |
| 516 | * @result: result from avc_has_perm_noaudit |
| 517 | * @a: auxiliary audit data |
| 518 | * |
| 519 | * Audit the granting or denial of permissions in accordance |
| 520 | * with the policy. This function is typically called by |
| 521 | * avc_has_perm() after a permission check, but can also be |
| 522 | * called directly by callers who use avc_has_perm_noaudit() |
| 523 | * in order to separate the permission check from the auditing. |
| 524 | * For example, this separation is useful when the permission check must |
| 525 | * be performed under a lock, to allow the lock to be released |
| 526 | * before calling the auditing code. |
| 527 | */ |
| 528 | void avc_audit(u32 ssid, u32 tsid, |
| 529 | u16 tclass, u32 requested, |
| 530 | struct av_decision *avd, int result, struct avc_audit_data *a) |
| 531 | { |
David Woodhouse | cd77b82 | 2005-05-19 11:18:24 +0100 | [diff] [blame] | 532 | struct task_struct *tsk = current; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 533 | struct inode *inode = NULL; |
| 534 | u32 denied, audited; |
| 535 | struct audit_buffer *ab; |
| 536 | |
| 537 | denied = requested & ~avd->allowed; |
| 538 | if (denied) { |
| 539 | audited = denied; |
| 540 | if (!(audited & avd->auditdeny)) |
| 541 | return; |
| 542 | } else if (result) { |
| 543 | audited = denied = requested; |
| 544 | } else { |
| 545 | audited = requested; |
| 546 | if (!(audited & avd->auditallow)) |
| 547 | return; |
| 548 | } |
| 549 | |
David Woodhouse | 9ad9ad3 | 2005-06-22 15:04:33 +0100 | [diff] [blame] | 550 | ab = audit_log_start(current->audit_context, GFP_ATOMIC, AUDIT_AVC); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 551 | if (!ab) |
| 552 | return; /* audit_panic has been called */ |
| 553 | audit_log_format(ab, "avc: %s ", denied ? "denied" : "granted"); |
| 554 | avc_dump_av(ab, tclass,audited); |
| 555 | audit_log_format(ab, " for "); |
David Woodhouse | cd77b82 | 2005-05-19 11:18:24 +0100 | [diff] [blame] | 556 | if (a && a->tsk) |
| 557 | tsk = a->tsk; |
David Woodhouse | 7b5d781 | 2005-05-21 16:52:57 +0100 | [diff] [blame] | 558 | if (tsk && tsk->pid) { |
David Woodhouse | cd77b82 | 2005-05-19 11:18:24 +0100 | [diff] [blame] | 559 | audit_log_format(ab, " pid=%d comm=", tsk->pid); |
| 560 | audit_log_untrustedstring(ab, tsk->comm); |
| 561 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 562 | if (a) { |
| 563 | switch (a->type) { |
| 564 | case AVC_AUDIT_DATA_IPC: |
| 565 | audit_log_format(ab, " key=%d", a->u.ipc_id); |
| 566 | break; |
| 567 | case AVC_AUDIT_DATA_CAP: |
| 568 | audit_log_format(ab, " capability=%d", a->u.cap); |
| 569 | break; |
| 570 | case AVC_AUDIT_DATA_FS: |
Jan Blunck | 44707fd | 2008-02-14 19:38:33 -0800 | [diff] [blame] | 571 | if (a->u.fs.path.dentry) { |
| 572 | struct dentry *dentry = a->u.fs.path.dentry; |
| 573 | if (a->u.fs.path.mnt) { |
| 574 | audit_log_d_path(ab, "path=", |
| 575 | &a->u.fs.path); |
Al Viro | 4259fa0 | 2007-06-07 11:13:31 -0400 | [diff] [blame] | 576 | } else { |
| 577 | audit_log_format(ab, " name="); |
| 578 | audit_log_untrustedstring(ab, dentry->d_name.name); |
| 579 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 580 | inode = dentry->d_inode; |
| 581 | } else if (a->u.fs.inode) { |
| 582 | struct dentry *dentry; |
| 583 | inode = a->u.fs.inode; |
| 584 | dentry = d_find_alias(inode); |
| 585 | if (dentry) { |
Stephen Smalley | 37ca538 | 2005-05-24 21:28:28 +0100 | [diff] [blame] | 586 | audit_log_format(ab, " name="); |
| 587 | audit_log_untrustedstring(ab, dentry->d_name.name); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 588 | dput(dentry); |
| 589 | } |
| 590 | } |
| 591 | if (inode) |
Tobias Oed | 13bddc2 | 2007-06-11 08:56:31 -0400 | [diff] [blame] | 592 | audit_log_format(ab, " dev=%s ino=%lu", |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 593 | inode->i_sb->s_id, |
| 594 | inode->i_ino); |
| 595 | break; |
| 596 | case AVC_AUDIT_DATA_NET: |
| 597 | if (a->u.net.sk) { |
| 598 | struct sock *sk = a->u.net.sk; |
| 599 | struct unix_sock *u; |
| 600 | int len = 0; |
| 601 | char *p = NULL; |
| 602 | |
| 603 | switch (sk->sk_family) { |
| 604 | case AF_INET: { |
| 605 | struct inet_sock *inet = inet_sk(sk); |
| 606 | |
| 607 | avc_print_ipv4_addr(ab, inet->rcv_saddr, |
| 608 | inet->sport, |
| 609 | "laddr", "lport"); |
| 610 | avc_print_ipv4_addr(ab, inet->daddr, |
| 611 | inet->dport, |
| 612 | "faddr", "fport"); |
| 613 | break; |
| 614 | } |
| 615 | case AF_INET6: { |
| 616 | struct inet_sock *inet = inet_sk(sk); |
| 617 | struct ipv6_pinfo *inet6 = inet6_sk(sk); |
| 618 | |
| 619 | avc_print_ipv6_addr(ab, &inet6->rcv_saddr, |
| 620 | inet->sport, |
| 621 | "laddr", "lport"); |
| 622 | avc_print_ipv6_addr(ab, &inet6->daddr, |
| 623 | inet->dport, |
| 624 | "faddr", "fport"); |
| 625 | break; |
| 626 | } |
| 627 | case AF_UNIX: |
| 628 | u = unix_sk(sk); |
| 629 | if (u->dentry) { |
Jan Blunck | 44707fd | 2008-02-14 19:38:33 -0800 | [diff] [blame] | 630 | struct path path = { |
| 631 | .dentry = u->dentry, |
| 632 | .mnt = u->mnt |
| 633 | }; |
Al Viro | 4259fa0 | 2007-06-07 11:13:31 -0400 | [diff] [blame] | 634 | audit_log_d_path(ab, "path=", |
Jan Blunck | 44707fd | 2008-02-14 19:38:33 -0800 | [diff] [blame] | 635 | &path); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 636 | break; |
| 637 | } |
| 638 | if (!u->addr) |
| 639 | break; |
| 640 | len = u->addr->len-sizeof(short); |
| 641 | p = &u->addr->name->sun_path[0]; |
Stephen Smalley | 37ca538 | 2005-05-24 21:28:28 +0100 | [diff] [blame] | 642 | audit_log_format(ab, " path="); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 643 | if (*p) |
Stephen Smalley | 37ca538 | 2005-05-24 21:28:28 +0100 | [diff] [blame] | 644 | audit_log_untrustedstring(ab, p); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 645 | else |
Stephen Smalley | 37ca538 | 2005-05-24 21:28:28 +0100 | [diff] [blame] | 646 | audit_log_hex(ab, p, len); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 647 | break; |
| 648 | } |
| 649 | } |
| 650 | |
| 651 | switch (a->u.net.family) { |
| 652 | case AF_INET: |
| 653 | avc_print_ipv4_addr(ab, a->u.net.v4info.saddr, |
| 654 | a->u.net.sport, |
| 655 | "saddr", "src"); |
| 656 | avc_print_ipv4_addr(ab, a->u.net.v4info.daddr, |
| 657 | a->u.net.dport, |
| 658 | "daddr", "dest"); |
| 659 | break; |
| 660 | case AF_INET6: |
| 661 | avc_print_ipv6_addr(ab, &a->u.net.v6info.saddr, |
| 662 | a->u.net.sport, |
| 663 | "saddr", "src"); |
| 664 | avc_print_ipv6_addr(ab, &a->u.net.v6info.daddr, |
| 665 | a->u.net.dport, |
| 666 | "daddr", "dest"); |
| 667 | break; |
| 668 | } |
Paul Moore | da5645a | 2008-01-29 08:38:10 -0500 | [diff] [blame] | 669 | if (a->u.net.netif > 0) { |
| 670 | struct net_device *dev; |
| 671 | |
| 672 | /* NOTE: we always use init's namespace */ |
| 673 | dev = dev_get_by_index(&init_net, |
| 674 | a->u.net.netif); |
| 675 | if (dev) { |
| 676 | audit_log_format(ab, " netif=%s", |
| 677 | dev->name); |
| 678 | dev_put(dev); |
| 679 | } |
| 680 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 681 | break; |
| 682 | } |
| 683 | } |
| 684 | audit_log_format(ab, " "); |
| 685 | avc_dump_query(ab, ssid, tsid, tclass); |
| 686 | audit_log_end(ab); |
| 687 | } |
| 688 | |
| 689 | /** |
| 690 | * avc_add_callback - Register a callback for security events. |
| 691 | * @callback: callback function |
| 692 | * @events: security events |
| 693 | * @ssid: source security identifier or %SECSID_WILD |
| 694 | * @tsid: target security identifier or %SECSID_WILD |
| 695 | * @tclass: target security class |
| 696 | * @perms: permissions |
| 697 | * |
| 698 | * Register a callback function for events in the set @events |
| 699 | * related to the SID pair (@ssid, @tsid) and |
| 700 | * and the permissions @perms, interpreting |
| 701 | * @perms based on @tclass. Returns %0 on success or |
| 702 | * -%ENOMEM if insufficient memory exists to add the callback. |
| 703 | */ |
| 704 | int avc_add_callback(int (*callback)(u32 event, u32 ssid, u32 tsid, |
| 705 | u16 tclass, u32 perms, |
| 706 | u32 *out_retained), |
| 707 | u32 events, u32 ssid, u32 tsid, |
| 708 | u16 tclass, u32 perms) |
| 709 | { |
| 710 | struct avc_callback_node *c; |
| 711 | int rc = 0; |
| 712 | |
| 713 | c = kmalloc(sizeof(*c), GFP_ATOMIC); |
| 714 | if (!c) { |
| 715 | rc = -ENOMEM; |
| 716 | goto out; |
| 717 | } |
| 718 | |
| 719 | c->callback = callback; |
| 720 | c->events = events; |
| 721 | c->ssid = ssid; |
| 722 | c->tsid = tsid; |
| 723 | c->perms = perms; |
| 724 | c->next = avc_callbacks; |
| 725 | avc_callbacks = c; |
| 726 | out: |
| 727 | return rc; |
| 728 | } |
| 729 | |
| 730 | static inline int avc_sidcmp(u32 x, u32 y) |
| 731 | { |
| 732 | return (x == y || x == SECSID_WILD || y == SECSID_WILD); |
| 733 | } |
| 734 | |
| 735 | /** |
| 736 | * avc_update_node Update an AVC entry |
| 737 | * @event : Updating event |
| 738 | * @perms : Permission mask bits |
| 739 | * @ssid,@tsid,@tclass : identifier of an AVC entry |
| 740 | * |
| 741 | * if a valid AVC entry doesn't exist,this function returns -ENOENT. |
| 742 | * if kmalloc() called internal returns NULL, this function returns -ENOMEM. |
| 743 | * otherwise, this function update the AVC entry. The original AVC-entry object |
| 744 | * will release later by RCU. |
| 745 | */ |
| 746 | static int avc_update_node(u32 event, u32 perms, u32 ssid, u32 tsid, u16 tclass) |
| 747 | { |
| 748 | int hvalue, rc = 0; |
| 749 | unsigned long flag; |
| 750 | struct avc_node *pos, *node, *orig = NULL; |
| 751 | |
| 752 | node = avc_alloc_node(); |
| 753 | if (!node) { |
| 754 | rc = -ENOMEM; |
| 755 | goto out; |
| 756 | } |
| 757 | |
| 758 | /* Lock the target slot */ |
| 759 | hvalue = avc_hash(ssid, tsid, tclass); |
| 760 | spin_lock_irqsave(&avc_cache.slots_lock[hvalue], flag); |
| 761 | |
| 762 | list_for_each_entry(pos, &avc_cache.slots[hvalue], list){ |
| 763 | if ( ssid==pos->ae.ssid && |
| 764 | tsid==pos->ae.tsid && |
| 765 | tclass==pos->ae.tclass ){ |
| 766 | orig = pos; |
| 767 | break; |
| 768 | } |
| 769 | } |
| 770 | |
| 771 | if (!orig) { |
| 772 | rc = -ENOENT; |
| 773 | avc_node_kill(node); |
| 774 | goto out_unlock; |
| 775 | } |
| 776 | |
| 777 | /* |
| 778 | * Copy and replace original node. |
| 779 | */ |
| 780 | |
| 781 | avc_node_populate(node, ssid, tsid, tclass, &orig->ae); |
| 782 | |
| 783 | switch (event) { |
| 784 | case AVC_CALLBACK_GRANT: |
| 785 | node->ae.avd.allowed |= perms; |
| 786 | break; |
| 787 | case AVC_CALLBACK_TRY_REVOKE: |
| 788 | case AVC_CALLBACK_REVOKE: |
| 789 | node->ae.avd.allowed &= ~perms; |
| 790 | break; |
| 791 | case AVC_CALLBACK_AUDITALLOW_ENABLE: |
| 792 | node->ae.avd.auditallow |= perms; |
| 793 | break; |
| 794 | case AVC_CALLBACK_AUDITALLOW_DISABLE: |
| 795 | node->ae.avd.auditallow &= ~perms; |
| 796 | break; |
| 797 | case AVC_CALLBACK_AUDITDENY_ENABLE: |
| 798 | node->ae.avd.auditdeny |= perms; |
| 799 | break; |
| 800 | case AVC_CALLBACK_AUDITDENY_DISABLE: |
| 801 | node->ae.avd.auditdeny &= ~perms; |
| 802 | break; |
| 803 | } |
| 804 | avc_node_replace(node, orig); |
| 805 | out_unlock: |
| 806 | spin_unlock_irqrestore(&avc_cache.slots_lock[hvalue], flag); |
| 807 | out: |
| 808 | return rc; |
| 809 | } |
| 810 | |
| 811 | /** |
| 812 | * avc_ss_reset - Flush the cache and revalidate migrated permissions. |
| 813 | * @seqno: policy sequence number |
| 814 | */ |
| 815 | int avc_ss_reset(u32 seqno) |
| 816 | { |
| 817 | struct avc_callback_node *c; |
Darrel Goeddel | 376bd9c | 2006-02-24 15:44:05 -0600 | [diff] [blame] | 818 | int i, rc = 0, tmprc; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 819 | unsigned long flag; |
| 820 | struct avc_node *node; |
| 821 | |
| 822 | for (i = 0; i < AVC_CACHE_SLOTS; i++) { |
| 823 | spin_lock_irqsave(&avc_cache.slots_lock[i], flag); |
| 824 | list_for_each_entry(node, &avc_cache.slots[i], list) |
| 825 | avc_node_delete(node); |
| 826 | spin_unlock_irqrestore(&avc_cache.slots_lock[i], flag); |
| 827 | } |
| 828 | |
| 829 | for (c = avc_callbacks; c; c = c->next) { |
| 830 | if (c->events & AVC_CALLBACK_RESET) { |
Darrel Goeddel | 376bd9c | 2006-02-24 15:44:05 -0600 | [diff] [blame] | 831 | tmprc = c->callback(AVC_CALLBACK_RESET, |
| 832 | 0, 0, 0, 0, NULL); |
| 833 | /* save the first error encountered for the return |
| 834 | value and continue processing the callbacks */ |
| 835 | if (!rc) |
| 836 | rc = tmprc; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 837 | } |
| 838 | } |
| 839 | |
| 840 | avc_latest_notif_update(seqno, 0); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 841 | return rc; |
| 842 | } |
| 843 | |
| 844 | /** |
| 845 | * avc_has_perm_noaudit - Check permissions but perform no auditing. |
| 846 | * @ssid: source security identifier |
| 847 | * @tsid: target security identifier |
| 848 | * @tclass: target security class |
| 849 | * @requested: requested permissions, interpreted based on @tclass |
Stephen Smalley | 2c3c05d | 2007-06-07 15:34:10 -0400 | [diff] [blame] | 850 | * @flags: AVC_STRICT or 0 |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 851 | * @avd: access vector decisions |
| 852 | * |
| 853 | * Check the AVC to determine whether the @requested permissions are granted |
| 854 | * for the SID pair (@ssid, @tsid), interpreting the permissions |
| 855 | * based on @tclass, and call the security server on a cache miss to obtain |
| 856 | * a new decision and add it to the cache. Return a copy of the decisions |
| 857 | * in @avd. Return %0 if all @requested permissions are granted, |
| 858 | * -%EACCES if any permissions are denied, or another -errno upon |
| 859 | * other errors. This function is typically called by avc_has_perm(), |
| 860 | * but may also be called directly to separate permission checking from |
| 861 | * auditing, e.g. in cases where a lock must be held for the check but |
| 862 | * should be released for the auditing. |
| 863 | */ |
| 864 | int avc_has_perm_noaudit(u32 ssid, u32 tsid, |
Stephen Smalley | 2c3c05d | 2007-06-07 15:34:10 -0400 | [diff] [blame] | 865 | u16 tclass, u32 requested, |
| 866 | unsigned flags, |
| 867 | struct av_decision *avd) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 868 | { |
| 869 | struct avc_node *node; |
| 870 | struct avc_entry entry, *p_ae; |
| 871 | int rc = 0; |
| 872 | u32 denied; |
| 873 | |
Eric Paris | eda4f69 | 2008-03-11 14:19:34 -0400 | [diff] [blame] | 874 | BUG_ON(!requested); |
| 875 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 876 | rcu_read_lock(); |
| 877 | |
| 878 | node = avc_lookup(ssid, tsid, tclass, requested); |
| 879 | if (!node) { |
| 880 | rcu_read_unlock(); |
| 881 | rc = security_compute_av(ssid,tsid,tclass,requested,&entry.avd); |
| 882 | if (rc) |
| 883 | goto out; |
| 884 | rcu_read_lock(); |
| 885 | node = avc_insert(ssid,tsid,tclass,&entry); |
| 886 | } |
| 887 | |
| 888 | p_ae = node ? &node->ae : &entry; |
| 889 | |
| 890 | if (avd) |
| 891 | memcpy(avd, &p_ae->avd, sizeof(*avd)); |
| 892 | |
| 893 | denied = requested & ~(p_ae->avd.allowed); |
| 894 | |
Eric Paris | eda4f69 | 2008-03-11 14:19:34 -0400 | [diff] [blame] | 895 | if (denied) { |
Eric Paris | 64dbf07 | 2008-03-31 12:17:33 +1100 | [diff] [blame] | 896 | if (flags & AVC_STRICT) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 897 | rc = -EACCES; |
Eric Paris | 64dbf07 | 2008-03-31 12:17:33 +1100 | [diff] [blame] | 898 | else if (!selinux_enforcing || security_permissive_sid(ssid)) |
| 899 | avc_update_node(AVC_CALLBACK_GRANT, requested, ssid, |
| 900 | tsid, tclass); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 901 | else |
Eric Paris | 64dbf07 | 2008-03-31 12:17:33 +1100 | [diff] [blame] | 902 | rc = -EACCES; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 903 | } |
| 904 | |
| 905 | rcu_read_unlock(); |
| 906 | out: |
| 907 | return rc; |
| 908 | } |
| 909 | |
| 910 | /** |
| 911 | * avc_has_perm - Check permissions and perform any appropriate auditing. |
| 912 | * @ssid: source security identifier |
| 913 | * @tsid: target security identifier |
| 914 | * @tclass: target security class |
| 915 | * @requested: requested permissions, interpreted based on @tclass |
| 916 | * @auditdata: auxiliary audit data |
| 917 | * |
| 918 | * Check the AVC to determine whether the @requested permissions are granted |
| 919 | * for the SID pair (@ssid, @tsid), interpreting the permissions |
| 920 | * based on @tclass, and call the security server on a cache miss to obtain |
| 921 | * a new decision and add it to the cache. Audit the granting or denial of |
| 922 | * permissions in accordance with the policy. Return %0 if all @requested |
| 923 | * permissions are granted, -%EACCES if any permissions are denied, or |
| 924 | * another -errno upon other errors. |
| 925 | */ |
| 926 | int avc_has_perm(u32 ssid, u32 tsid, u16 tclass, |
| 927 | u32 requested, struct avc_audit_data *auditdata) |
| 928 | { |
| 929 | struct av_decision avd; |
| 930 | int rc; |
| 931 | |
Stephen Smalley | 2c3c05d | 2007-06-07 15:34:10 -0400 | [diff] [blame] | 932 | rc = avc_has_perm_noaudit(ssid, tsid, tclass, requested, 0, &avd); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 933 | avc_audit(ssid, tsid, tclass, requested, &avd, rc, auditdata); |
| 934 | return rc; |
| 935 | } |
Yuichi Nakamura | 788e7dd | 2007-09-14 09:27:07 +0900 | [diff] [blame] | 936 | |
| 937 | u32 avc_policy_seqno(void) |
| 938 | { |
| 939 | return avc_cache.latest_notif; |
| 940 | } |