root/net/netlabel/netlabel_domainhash.c

DEFINITIONS

1. netlbl_domhsh_free_entry
2. netlbl_domhsh_hash
3. netlbl_family_match
4. netlbl_domhsh_search
5. netlbl_domhsh_search_def
6. netlbl_domhsh_audit_add
7. netlbl_domhsh_validate
8. netlbl_domhsh_init
9. netlbl_domhsh_add
10. netlbl_domhsh_add_default
11. netlbl_domhsh_remove_entry
12. netlbl_domhsh_remove_af4
13. netlbl_domhsh_remove_af6
14. netlbl_domhsh_remove
15. netlbl_domhsh_remove_default
16. netlbl_domhsh_getentry
17. netlbl_domhsh_getentry_af4
18. netlbl_domhsh_getentry_af6
19. netlbl_domhsh_walk

   1 // SPDX-License-Identifier: GPL-2.0-or-later
   2 /*
   3  * NetLabel Domain Hash Table
   4  *
   5  * This file manages the domain hash table that NetLabel uses to determine
   6  * which network labeling protocol to use for a given domain.  The NetLabel
   7  * system manages static and dynamic label mappings for network protocols such
   8  * as CIPSO and RIPSO.
   9  *
  10  * Author: Paul Moore <paul@paul-moore.com>
  11  */
  12 
  13 /*
  14  * (c) Copyright Hewlett-Packard Development Company, L.P., 2006, 2008
  15  */
  16 
  17 #include <linux/types.h>
  18 #include <linux/rculist.h>
  19 #include <linux/skbuff.h>
  20 #include <linux/spinlock.h>
  21 #include <linux/string.h>
  22 #include <linux/audit.h>
  23 #include <linux/slab.h>
  24 #include <net/netlabel.h>
  25 #include <net/cipso_ipv4.h>
  26 #include <net/calipso.h>
  27 #include <asm/bug.h>
  28 
  29 #include "netlabel_mgmt.h"
  30 #include "netlabel_addrlist.h"
  31 #include "netlabel_calipso.h"
  32 #include "netlabel_domainhash.h"
  33 #include "netlabel_user.h"
  34 
  35 struct netlbl_domhsh_tbl {
  36         struct list_head *tbl;
  37         u32 size;
  38 };
  39 
  40 /* Domain hash table */
  41 /* updates should be so rare that having one spinlock for the entire hash table
  42  * should be okay */
  43 static DEFINE_SPINLOCK(netlbl_domhsh_lock);
  44 #define netlbl_domhsh_rcu_deref(p) \
  45         rcu_dereference_check(p, lockdep_is_held(&netlbl_domhsh_lock))
  46 static struct netlbl_domhsh_tbl __rcu *netlbl_domhsh;
  47 static struct netlbl_dom_map __rcu *netlbl_domhsh_def_ipv4;
  48 static struct netlbl_dom_map __rcu *netlbl_domhsh_def_ipv6;
  49 
  50 /*
  51  * Domain Hash Table Helper Functions
  52  */
  53 
  54 /**
  55  * netlbl_domhsh_free_entry - Frees a domain hash table entry
  56  * @entry: the entry's RCU field
  57  *
  58  * Description:
  59  * This function is designed to be used as a callback to the call_rcu()
  60  * function so that the memory allocated to a hash table entry can be released
  61  * safely.
  62  *
  63  */
  64 static void netlbl_domhsh_free_entry(struct rcu_head *entry)
  65 {
  66         struct netlbl_dom_map *ptr;
  67         struct netlbl_af4list *iter4;
  68         struct netlbl_af4list *tmp4;
  69 #if IS_ENABLED(CONFIG_IPV6)
  70         struct netlbl_af6list *iter6;
  71         struct netlbl_af6list *tmp6;
  72 #endif /* IPv6 */
  73 
  74         ptr = container_of(entry, struct netlbl_dom_map, rcu);
  75         if (ptr->def.type == NETLBL_NLTYPE_ADDRSELECT) {
  76                 netlbl_af4list_foreach_safe(iter4, tmp4,
  77                                             &ptr->def.addrsel->list4) {
  78                         netlbl_af4list_remove_entry(iter4);
  79                         kfree(netlbl_domhsh_addr4_entry(iter4));
  80                 }
  81 #if IS_ENABLED(CONFIG_IPV6)
  82                 netlbl_af6list_foreach_safe(iter6, tmp6,
  83                                             &ptr->def.addrsel->list6) {
  84                         netlbl_af6list_remove_entry(iter6);
  85                         kfree(netlbl_domhsh_addr6_entry(iter6));
  86                 }
  87 #endif /* IPv6 */
  88         }
  89         kfree(ptr->domain);
  90         kfree(ptr);
  91 }
  92 
  93 /**
  94  * netlbl_domhsh_hash - Hashing function for the domain hash table
  95  * @domain: the domain name to hash
  96  *
  97  * Description:
  98  * This is the hashing function for the domain hash table, it returns the
  99  * correct bucket number for the domain.  The caller is responsible for
 100  * ensuring that the hash table is protected with either a RCU read lock or the
 101  * hash table lock.
 102  *
 103  */
 104 static u32 netlbl_domhsh_hash(const char *key)
 105 {
 106         u32 iter;
 107         u32 val;
 108         u32 len;
 109 
 110         /* This is taken (with slight modification) from
 111          * security/selinux/ss/symtab.c:symhash() */
 112 
 113         for (iter = 0, val = 0, len = strlen(key); iter < len; iter++)
 114                 val = (val << 4 | (val >> (8 * sizeof(u32) - 4))) ^ key[iter];
 115         return val & (netlbl_domhsh_rcu_deref(netlbl_domhsh)->size - 1);
 116 }
 117 
 118 static bool netlbl_family_match(u16 f1, u16 f2)
 119 {
 120         return (f1 == f2) || (f1 == AF_UNSPEC) || (f2 == AF_UNSPEC);
 121 }
 122 
 123 /**
 124  * netlbl_domhsh_search - Search for a domain entry
 125  * @domain: the domain
 126  * @family: the address family
 127  *
 128  * Description:
 129  * Searches the domain hash table and returns a pointer to the hash table
 130  * entry if found, otherwise NULL is returned.  @family may be %AF_UNSPEC
 131  * which matches any address family entries.  The caller is responsible for
 132  * ensuring that the hash table is protected with either a RCU read lock or the
 133  * hash table lock.
 134  *
 135  */
 136 static struct netlbl_dom_map *netlbl_domhsh_search(const char *domain,
 137                                                    u16 family)
 138 {
 139         u32 bkt;
 140         struct list_head *bkt_list;
 141         struct netlbl_dom_map *iter;
 142 
 143         if (domain != NULL) {
 144                 bkt = netlbl_domhsh_hash(domain);
 145                 bkt_list = &netlbl_domhsh_rcu_deref(netlbl_domhsh)->tbl[bkt];
 146                 list_for_each_entry_rcu(iter, bkt_list, list)
 147                         if (iter->valid &&
 148                             netlbl_family_match(iter->family, family) &&
 149                             strcmp(iter->domain, domain) == 0)
 150                                 return iter;
 151         }
 152 
 153         return NULL;
 154 }
 155 
 156 /**
 157  * netlbl_domhsh_search_def - Search for a domain entry
 158  * @domain: the domain
 159  * @family: the address family
 160  *
 161  * Description:
 162  * Searches the domain hash table and returns a pointer to the hash table
 163  * entry if an exact match is found, if an exact match is not present in the
 164  * hash table then the default entry is returned if valid otherwise NULL is
 165  * returned.  @family may be %AF_UNSPEC which matches any address family
 166  * entries.  The caller is responsible ensuring that the hash table is
 167  * protected with either a RCU read lock or the hash table lock.
 168  *
 169  */
 170 static struct netlbl_dom_map *netlbl_domhsh_search_def(const char *domain,
 171                                                        u16 family)
 172 {
 173         struct netlbl_dom_map *entry;
 174 
 175         entry = netlbl_domhsh_search(domain, family);
 176         if (entry != NULL)
 177                 return entry;
 178         if (family == AF_INET || family == AF_UNSPEC) {
 179                 entry = netlbl_domhsh_rcu_deref(netlbl_domhsh_def_ipv4);
 180                 if (entry != NULL && entry->valid)
 181                         return entry;
 182         }
 183         if (family == AF_INET6 || family == AF_UNSPEC) {
 184                 entry = netlbl_domhsh_rcu_deref(netlbl_domhsh_def_ipv6);
 185                 if (entry != NULL && entry->valid)
 186                         return entry;
 187         }
 188 
 189         return NULL;
 190 }
 191 
 192 /**
 193  * netlbl_domhsh_audit_add - Generate an audit entry for an add event
 194  * @entry: the entry being added
 195  * @addr4: the IPv4 address information
 196  * @addr6: the IPv6 address information
 197  * @result: the result code
 198  * @audit_info: NetLabel audit information
 199  *
 200  * Description:
 201  * Generate an audit record for adding a new NetLabel/LSM mapping entry with
 202  * the given information.  Caller is responsible for holding the necessary
 203  * locks.
 204  *
 205  */
 206 static void netlbl_domhsh_audit_add(struct netlbl_dom_map *entry,
 207                                     struct netlbl_af4list *addr4,
 208                                     struct netlbl_af6list *addr6,
 209                                     int result,
 210                                     struct netlbl_audit *audit_info)
 211 {
 212         struct audit_buffer *audit_buf;
 213         struct cipso_v4_doi *cipsov4 = NULL;
 214         struct calipso_doi *calipso = NULL;
 215         u32 type;
 216 
 217         audit_buf = netlbl_audit_start_common(AUDIT_MAC_MAP_ADD, audit_info);
 218         if (audit_buf != NULL) {
 219                 audit_log_format(audit_buf, " nlbl_domain=%s",
 220                                  entry->domain ? entry->domain : "(default)");
 221                 if (addr4 != NULL) {
 222                         struct netlbl_domaddr4_map *map4;
 223                         map4 = netlbl_domhsh_addr4_entry(addr4);
 224                         type = map4->def.type;
 225                         cipsov4 = map4->def.cipso;
 226                         netlbl_af4list_audit_addr(audit_buf, 0, NULL,
 227                                                   addr4->addr, addr4->mask);
 228 #if IS_ENABLED(CONFIG_IPV6)
 229                 } else if (addr6 != NULL) {
 230                         struct netlbl_domaddr6_map *map6;
 231                         map6 = netlbl_domhsh_addr6_entry(addr6);
 232                         type = map6->def.type;
 233                         calipso = map6->def.calipso;
 234                         netlbl_af6list_audit_addr(audit_buf, 0, NULL,
 235                                                   &addr6->addr, &addr6->mask);
 236 #endif /* IPv6 */
 237                 } else {
 238                         type = entry->def.type;
 239                         cipsov4 = entry->def.cipso;
 240                         calipso = entry->def.calipso;
 241                 }
 242                 switch (type) {
 243                 case NETLBL_NLTYPE_UNLABELED:
 244                         audit_log_format(audit_buf, " nlbl_protocol=unlbl");
 245                         break;
 246                 case NETLBL_NLTYPE_CIPSOV4:
 247                         BUG_ON(cipsov4 == NULL);
 248                         audit_log_format(audit_buf,
 249                                          " nlbl_protocol=cipsov4 cipso_doi=%u",
 250                                          cipsov4->doi);
 251                         break;
 252                 case NETLBL_NLTYPE_CALIPSO:
 253                         BUG_ON(calipso == NULL);
 254                         audit_log_format(audit_buf,
 255                                          " nlbl_protocol=calipso calipso_doi=%u",
 256                                          calipso->doi);
 257                         break;
 258                 }
 259                 audit_log_format(audit_buf, " res=%u", result == 0 ? 1 : 0);
 260                 audit_log_end(audit_buf);
 261         }
 262 }
 263 
 264 /**
 265  * netlbl_domhsh_validate - Validate a new domain mapping entry
 266  * @entry: the entry to validate
 267  *
 268  * This function validates the new domain mapping entry to ensure that it is
 269  * a valid entry.  Returns zero on success, negative values on failure.
 270  *
 271  */
 272 static int netlbl_domhsh_validate(const struct netlbl_dom_map *entry)
 273 {
 274         struct netlbl_af4list *iter4;
 275         struct netlbl_domaddr4_map *map4;
 276 #if IS_ENABLED(CONFIG_IPV6)
 277         struct netlbl_af6list *iter6;
 278         struct netlbl_domaddr6_map *map6;
 279 #endif /* IPv6 */
 280 
 281         if (entry == NULL)
 282                 return -EINVAL;
 283 
 284         if (entry->family != AF_INET && entry->family != AF_INET6 &&
 285             (entry->family != AF_UNSPEC ||
 286              entry->def.type != NETLBL_NLTYPE_UNLABELED))
 287                 return -EINVAL;
 288 
 289         switch (entry->def.type) {
 290         case NETLBL_NLTYPE_UNLABELED:
 291                 if (entry->def.cipso != NULL || entry->def.calipso != NULL ||
 292                     entry->def.addrsel != NULL)
 293                         return -EINVAL;
 294                 break;
 295         case NETLBL_NLTYPE_CIPSOV4:
 296                 if (entry->family != AF_INET ||
 297                     entry->def.cipso == NULL)
 298                         return -EINVAL;
 299                 break;
 300         case NETLBL_NLTYPE_CALIPSO:
 301                 if (entry->family != AF_INET6 ||
 302                     entry->def.calipso == NULL)
 303                         return -EINVAL;
 304                 break;
 305         case NETLBL_NLTYPE_ADDRSELECT:
 306                 netlbl_af4list_foreach(iter4, &entry->def.addrsel->list4) {
 307                         map4 = netlbl_domhsh_addr4_entry(iter4);
 308                         switch (map4->def.type) {
 309                         case NETLBL_NLTYPE_UNLABELED:
 310                                 if (map4->def.cipso != NULL)
 311                                         return -EINVAL;
 312                                 break;
 313                         case NETLBL_NLTYPE_CIPSOV4:
 314                                 if (map4->def.cipso == NULL)
 315                                         return -EINVAL;
 316                                 break;
 317                         default:
 318                                 return -EINVAL;
 319                         }
 320                 }
 321 #if IS_ENABLED(CONFIG_IPV6)
 322                 netlbl_af6list_foreach(iter6, &entry->def.addrsel->list6) {
 323                         map6 = netlbl_domhsh_addr6_entry(iter6);
 324                         switch (map6->def.type) {
 325                         case NETLBL_NLTYPE_UNLABELED:
 326                                 if (map6->def.calipso != NULL)
 327                                         return -EINVAL;
 328                                 break;
 329                         case NETLBL_NLTYPE_CALIPSO:
 330                                 if (map6->def.calipso == NULL)
 331                                         return -EINVAL;
 332                                 break;
 333                         default:
 334                                 return -EINVAL;
 335                         }
 336                 }
 337 #endif /* IPv6 */
 338                 break;
 339         default:
 340                 return -EINVAL;
 341         }
 342 
 343         return 0;
 344 }
 345 
 346 /*
 347  * Domain Hash Table Functions
 348  */
 349 
 350 /**
 351  * netlbl_domhsh_init - Init for the domain hash
 352  * @size: the number of bits to use for the hash buckets
 353  *
 354  * Description:
 355  * Initializes the domain hash table, should be called only by
 356  * netlbl_user_init() during initialization.  Returns zero on success, non-zero
 357  * values on error.
 358  *
 359  */
 360 int __init netlbl_domhsh_init(u32 size)
 361 {
 362         u32 iter;
 363         struct netlbl_domhsh_tbl *hsh_tbl;
 364 
 365         if (size == 0)
 366                 return -EINVAL;
 367 
 368         hsh_tbl = kmalloc(sizeof(*hsh_tbl), GFP_KERNEL);
 369         if (hsh_tbl == NULL)
 370                 return -ENOMEM;
 371         hsh_tbl->size = 1 << size;
 372         hsh_tbl->tbl = kcalloc(hsh_tbl->size,
 373                                sizeof(struct list_head),
 374                                GFP_KERNEL);
 375         if (hsh_tbl->tbl == NULL) {
 376                 kfree(hsh_tbl);
 377                 return -ENOMEM;
 378         }
 379         for (iter = 0; iter < hsh_tbl->size; iter++)
 380                 INIT_LIST_HEAD(&hsh_tbl->tbl[iter]);
 381 
 382         spin_lock(&netlbl_domhsh_lock);
 383         rcu_assign_pointer(netlbl_domhsh, hsh_tbl);
 384         spin_unlock(&netlbl_domhsh_lock);
 385 
 386         return 0;
 387 }
 388 
 389 /**
 390  * netlbl_domhsh_add - Adds a entry to the domain hash table
 391  * @entry: the entry to add
 392  * @audit_info: NetLabel audit information
 393  *
 394  * Description:
 395  * Adds a new entry to the domain hash table and handles any updates to the
 396  * lower level protocol handler (i.e. CIPSO).  @entry->family may be set to
 397  * %AF_UNSPEC which will add an entry that matches all address families.  This
 398  * is only useful for the unlabelled type and will only succeed if there is no
 399  * existing entry for any address family with the same domain.  Returns zero
 400  * on success, negative on failure.
 401  *
 402  */
 403 int netlbl_domhsh_add(struct netlbl_dom_map *entry,
 404                       struct netlbl_audit *audit_info)
 405 {
 406         int ret_val = 0;
 407         struct netlbl_dom_map *entry_old, *entry_b;
 408         struct netlbl_af4list *iter4;
 409         struct netlbl_af4list *tmp4;
 410 #if IS_ENABLED(CONFIG_IPV6)
 411         struct netlbl_af6list *iter6;
 412         struct netlbl_af6list *tmp6;
 413 #endif /* IPv6 */
 414 
 415         ret_val = netlbl_domhsh_validate(entry);
 416         if (ret_val != 0)
 417                 return ret_val;
 418 
 419         /* XXX - we can remove this RCU read lock as the spinlock protects the
 420          *       entire function, but before we do we need to fixup the
 421          *       netlbl_af[4,6]list RCU functions to do "the right thing" with
 422          *       respect to rcu_dereference() when only a spinlock is held. */
 423         rcu_read_lock();
 424         spin_lock(&netlbl_domhsh_lock);
 425         if (entry->domain != NULL)
 426                 entry_old = netlbl_domhsh_search(entry->domain, entry->family);
 427         else
 428                 entry_old = netlbl_domhsh_search_def(entry->domain,
 429                                                      entry->family);
 430         if (entry_old == NULL) {
 431                 entry->valid = 1;
 432 
 433                 if (entry->domain != NULL) {
 434                         u32 bkt = netlbl_domhsh_hash(entry->domain);
 435                         list_add_tail_rcu(&entry->list,
 436                                     &rcu_dereference(netlbl_domhsh)->tbl[bkt]);
 437                 } else {
 438                         INIT_LIST_HEAD(&entry->list);
 439                         switch (entry->family) {
 440                         case AF_INET:
 441                                 rcu_assign_pointer(netlbl_domhsh_def_ipv4,
 442                                                    entry);
 443                                 break;
 444                         case AF_INET6:
 445                                 rcu_assign_pointer(netlbl_domhsh_def_ipv6,
 446                                                    entry);
 447                                 break;
 448                         case AF_UNSPEC:
 449                                 if (entry->def.type !=
 450                                     NETLBL_NLTYPE_UNLABELED) {
 451                                         ret_val = -EINVAL;
 452                                         goto add_return;
 453                                 }
 454                                 entry_b = kzalloc(sizeof(*entry_b), GFP_ATOMIC);
 455                                 if (entry_b == NULL) {
 456                                         ret_val = -ENOMEM;
 457                                         goto add_return;
 458                                 }
 459                                 entry_b->family = AF_INET6;
 460                                 entry_b->def.type = NETLBL_NLTYPE_UNLABELED;
 461                                 entry_b->valid = 1;
 462                                 entry->family = AF_INET;
 463                                 rcu_assign_pointer(netlbl_domhsh_def_ipv4,
 464                                                    entry);
 465                                 rcu_assign_pointer(netlbl_domhsh_def_ipv6,
 466                                                    entry_b);
 467                                 break;
 468                         default:
 469                                 /* Already checked in
 470                                  * netlbl_domhsh_validate(). */
 471                                 ret_val = -EINVAL;
 472                                 goto add_return;
 473                         }
 474                 }
 475 
 476                 if (entry->def.type == NETLBL_NLTYPE_ADDRSELECT) {
 477                         netlbl_af4list_foreach_rcu(iter4,
 478                                                    &entry->def.addrsel->list4)
 479                                 netlbl_domhsh_audit_add(entry, iter4, NULL,
 480                                                         ret_val, audit_info);
 481 #if IS_ENABLED(CONFIG_IPV6)
 482                         netlbl_af6list_foreach_rcu(iter6,
 483                                                    &entry->def.addrsel->list6)
 484                                 netlbl_domhsh_audit_add(entry, NULL, iter6,
 485                                                         ret_val, audit_info);
 486 #endif /* IPv6 */
 487                 } else
 488                         netlbl_domhsh_audit_add(entry, NULL, NULL,
 489                                                 ret_val, audit_info);
 490         } else if (entry_old->def.type == NETLBL_NLTYPE_ADDRSELECT &&
 491                    entry->def.type == NETLBL_NLTYPE_ADDRSELECT) {
 492                 struct list_head *old_list4;
 493                 struct list_head *old_list6;
 494 
 495                 old_list4 = &entry_old->def.addrsel->list4;
 496                 old_list6 = &entry_old->def.addrsel->list6;
 497 
 498                 /* we only allow the addition of address selectors if all of
 499                  * the selectors do not exist in the existing domain map */
 500                 netlbl_af4list_foreach_rcu(iter4, &entry->def.addrsel->list4)
 501                         if (netlbl_af4list_search_exact(iter4->addr,
 502                                                         iter4->mask,
 503                                                         old_list4)) {
 504                                 ret_val = -EEXIST;
 505                                 goto add_return;
 506                         }
 507 #if IS_ENABLED(CONFIG_IPV6)
 508                 netlbl_af6list_foreach_rcu(iter6, &entry->def.addrsel->list6)
 509                         if (netlbl_af6list_search_exact(&iter6->addr,
 510                                                         &iter6->mask,
 511                                                         old_list6)) {
 512                                 ret_val = -EEXIST;
 513                                 goto add_return;
 514                         }
 515 #endif /* IPv6 */
 516 
 517                 netlbl_af4list_foreach_safe(iter4, tmp4,
 518                                             &entry->def.addrsel->list4) {
 519                         netlbl_af4list_remove_entry(iter4);
 520                         iter4->valid = 1;
 521                         ret_val = netlbl_af4list_add(iter4, old_list4);
 522                         netlbl_domhsh_audit_add(entry_old, iter4, NULL,
 523                                                 ret_val, audit_info);
 524                         if (ret_val != 0)
 525                                 goto add_return;
 526                 }
 527 #if IS_ENABLED(CONFIG_IPV6)
 528                 netlbl_af6list_foreach_safe(iter6, tmp6,
 529                                             &entry->def.addrsel->list6) {
 530                         netlbl_af6list_remove_entry(iter6);
 531                         iter6->valid = 1;
 532                         ret_val = netlbl_af6list_add(iter6, old_list6);
 533                         netlbl_domhsh_audit_add(entry_old, NULL, iter6,
 534                                                 ret_val, audit_info);
 535                         if (ret_val != 0)
 536                                 goto add_return;
 537                 }
 538 #endif /* IPv6 */
 539         } else
 540                 ret_val = -EINVAL;
 541 
 542 add_return:
 543         spin_unlock(&netlbl_domhsh_lock);
 544         rcu_read_unlock();
 545         return ret_val;
 546 }
 547 
 548 /**
 549  * netlbl_domhsh_add_default - Adds the default entry to the domain hash table
 550  * @entry: the entry to add
 551  * @audit_info: NetLabel audit information
 552  *
 553  * Description:
 554  * Adds a new default entry to the domain hash table and handles any updates
 555  * to the lower level protocol handler (i.e. CIPSO).  Returns zero on success,
 556  * negative on failure.
 557  *
 558  */
 559 int netlbl_domhsh_add_default(struct netlbl_dom_map *entry,
 560                               struct netlbl_audit *audit_info)
 561 {
 562         return netlbl_domhsh_add(entry, audit_info);
 563 }
 564 
 565 /**
 566  * netlbl_domhsh_remove_entry - Removes a given entry from the domain table
 567  * @entry: the entry to remove
 568  * @audit_info: NetLabel audit information
 569  *
 570  * Description:
 571  * Removes an entry from the domain hash table and handles any updates to the
 572  * lower level protocol handler (i.e. CIPSO).  Caller is responsible for
 573  * ensuring that the RCU read lock is held.  Returns zero on success, negative
 574  * on failure.
 575  *
 576  */
 577 int netlbl_domhsh_remove_entry(struct netlbl_dom_map *entry,
 578                                struct netlbl_audit *audit_info)
 579 {
 580         int ret_val = 0;
 581         struct audit_buffer *audit_buf;
 582 
 583         if (entry == NULL)
 584                 return -ENOENT;
 585 
 586         spin_lock(&netlbl_domhsh_lock);
 587         if (entry->valid) {
 588                 entry->valid = 0;
 589                 if (entry == rcu_dereference(netlbl_domhsh_def_ipv4))
 590                         RCU_INIT_POINTER(netlbl_domhsh_def_ipv4, NULL);
 591                 else if (entry == rcu_dereference(netlbl_domhsh_def_ipv6))
 592                         RCU_INIT_POINTER(netlbl_domhsh_def_ipv6, NULL);
 593                 else
 594                         list_del_rcu(&entry->list);
 595         } else
 596                 ret_val = -ENOENT;
 597         spin_unlock(&netlbl_domhsh_lock);
 598 
 599         audit_buf = netlbl_audit_start_common(AUDIT_MAC_MAP_DEL, audit_info);
 600         if (audit_buf != NULL) {
 601                 audit_log_format(audit_buf,
 602                                  " nlbl_domain=%s res=%u",
 603                                  entry->domain ? entry->domain : "(default)",
 604                                  ret_val == 0 ? 1 : 0);
 605                 audit_log_end(audit_buf);
 606         }
 607 
 608         if (ret_val == 0) {
 609                 struct netlbl_af4list *iter4;
 610                 struct netlbl_domaddr4_map *map4;
 611 #if IS_ENABLED(CONFIG_IPV6)
 612                 struct netlbl_af6list *iter6;
 613                 struct netlbl_domaddr6_map *map6;
 614 #endif /* IPv6 */
 615 
 616                 switch (entry->def.type) {
 617                 case NETLBL_NLTYPE_ADDRSELECT:
 618                         netlbl_af4list_foreach_rcu(iter4,
 619                                              &entry->def.addrsel->list4) {
 620                                 map4 = netlbl_domhsh_addr4_entry(iter4);
 621                                 cipso_v4_doi_putdef(map4->def.cipso);
 622                         }
 623 #if IS_ENABLED(CONFIG_IPV6)
 624                         netlbl_af6list_foreach_rcu(iter6,
 625                                              &entry->def.addrsel->list6) {
 626                                 map6 = netlbl_domhsh_addr6_entry(iter6);
 627                                 calipso_doi_putdef(map6->def.calipso);
 628                         }
 629 #endif /* IPv6 */
 630                         break;
 631                 case NETLBL_NLTYPE_CIPSOV4:
 632                         cipso_v4_doi_putdef(entry->def.cipso);
 633                         break;
 634 #if IS_ENABLED(CONFIG_IPV6)
 635                 case NETLBL_NLTYPE_CALIPSO:
 636                         calipso_doi_putdef(entry->def.calipso);
 637                         break;
 638 #endif /* IPv6 */
 639                 }
 640                 call_rcu(&entry->rcu, netlbl_domhsh_free_entry);
 641         }
 642 
 643         return ret_val;
 644 }
 645 
 646 /**
 647  * netlbl_domhsh_remove_af4 - Removes an address selector entry
 648  * @domain: the domain
 649  * @addr: IPv4 address
 650  * @mask: IPv4 address mask
 651  * @audit_info: NetLabel audit information
 652  *
 653  * Description:
 654  * Removes an individual address selector from a domain mapping and potentially
 655  * the entire mapping if it is empty.  Returns zero on success, negative values
 656  * on failure.
 657  *
 658  */
 659 int netlbl_domhsh_remove_af4(const char *domain,
 660                              const struct in_addr *addr,
 661                              const struct in_addr *mask,
 662                              struct netlbl_audit *audit_info)
 663 {
 664         struct netlbl_dom_map *entry_map;
 665         struct netlbl_af4list *entry_addr;
 666         struct netlbl_af4list *iter4;
 667 #if IS_ENABLED(CONFIG_IPV6)
 668         struct netlbl_af6list *iter6;
 669 #endif /* IPv6 */
 670         struct netlbl_domaddr4_map *entry;
 671 
 672         rcu_read_lock();
 673 
 674         if (domain)
 675                 entry_map = netlbl_domhsh_search(domain, AF_INET);
 676         else
 677                 entry_map = netlbl_domhsh_search_def(domain, AF_INET);
 678         if (entry_map == NULL ||
 679             entry_map->def.type != NETLBL_NLTYPE_ADDRSELECT)
 680                 goto remove_af4_failure;
 681 
 682         spin_lock(&netlbl_domhsh_lock);
 683         entry_addr = netlbl_af4list_remove(addr->s_addr, mask->s_addr,
 684                                            &entry_map->def.addrsel->list4);
 685         spin_unlock(&netlbl_domhsh_lock);
 686 
 687         if (entry_addr == NULL)
 688                 goto remove_af4_failure;
 689         netlbl_af4list_foreach_rcu(iter4, &entry_map->def.addrsel->list4)
 690                 goto remove_af4_single_addr;
 691 #if IS_ENABLED(CONFIG_IPV6)
 692         netlbl_af6list_foreach_rcu(iter6, &entry_map->def.addrsel->list6)
 693                 goto remove_af4_single_addr;
 694 #endif /* IPv6 */
 695         /* the domain mapping is empty so remove it from the mapping table */
 696         netlbl_domhsh_remove_entry(entry_map, audit_info);
 697 
 698 remove_af4_single_addr:
 699         rcu_read_unlock();
 700         /* yick, we can't use call_rcu here because we don't have a rcu head
 701          * pointer but hopefully this should be a rare case so the pause
 702          * shouldn't be a problem */
 703         synchronize_rcu();
 704         entry = netlbl_domhsh_addr4_entry(entry_addr);
 705         cipso_v4_doi_putdef(entry->def.cipso);
 706         kfree(entry);
 707         return 0;
 708 
 709 remove_af4_failure:
 710         rcu_read_unlock();
 711         return -ENOENT;
 712 }
 713 
 714 #if IS_ENABLED(CONFIG_IPV6)
 715 /**
 716  * netlbl_domhsh_remove_af6 - Removes an address selector entry
 717  * @domain: the domain
 718  * @addr: IPv6 address
 719  * @mask: IPv6 address mask
 720  * @audit_info: NetLabel audit information
 721  *
 722  * Description:
 723  * Removes an individual address selector from a domain mapping and potentially
 724  * the entire mapping if it is empty.  Returns zero on success, negative values
 725  * on failure.
 726  *
 727  */
 728 int netlbl_domhsh_remove_af6(const char *domain,
 729                              const struct in6_addr *addr,
 730                              const struct in6_addr *mask,
 731                              struct netlbl_audit *audit_info)
 732 {
 733         struct netlbl_dom_map *entry_map;
 734         struct netlbl_af6list *entry_addr;
 735         struct netlbl_af4list *iter4;
 736         struct netlbl_af6list *iter6;
 737         struct netlbl_domaddr6_map *entry;
 738 
 739         rcu_read_lock();
 740 
 741         if (domain)
 742                 entry_map = netlbl_domhsh_search(domain, AF_INET6);
 743         else
 744                 entry_map = netlbl_domhsh_search_def(domain, AF_INET6);
 745         if (entry_map == NULL ||
 746             entry_map->def.type != NETLBL_NLTYPE_ADDRSELECT)
 747                 goto remove_af6_failure;
 748 
 749         spin_lock(&netlbl_domhsh_lock);
 750         entry_addr = netlbl_af6list_remove(addr, mask,
 751                                            &entry_map->def.addrsel->list6);
 752         spin_unlock(&netlbl_domhsh_lock);
 753 
 754         if (entry_addr == NULL)
 755                 goto remove_af6_failure;
 756         netlbl_af4list_foreach_rcu(iter4, &entry_map->def.addrsel->list4)
 757                 goto remove_af6_single_addr;
 758         netlbl_af6list_foreach_rcu(iter6, &entry_map->def.addrsel->list6)
 759                 goto remove_af6_single_addr;
 760         /* the domain mapping is empty so remove it from the mapping table */
 761         netlbl_domhsh_remove_entry(entry_map, audit_info);
 762 
 763 remove_af6_single_addr:
 764         rcu_read_unlock();
 765         /* yick, we can't use call_rcu here because we don't have a rcu head
 766          * pointer but hopefully this should be a rare case so the pause
 767          * shouldn't be a problem */
 768         synchronize_rcu();
 769         entry = netlbl_domhsh_addr6_entry(entry_addr);
 770         calipso_doi_putdef(entry->def.calipso);
 771         kfree(entry);
 772         return 0;
 773 
 774 remove_af6_failure:
 775         rcu_read_unlock();
 776         return -ENOENT;
 777 }
 778 #endif /* IPv6 */
 779 
 780 /**
 781  * netlbl_domhsh_remove - Removes an entry from the domain hash table
 782  * @domain: the domain to remove
 783  * @family: address family
 784  * @audit_info: NetLabel audit information
 785  *
 786  * Description:
 787  * Removes an entry from the domain hash table and handles any updates to the
 788  * lower level protocol handler (i.e. CIPSO).  @family may be %AF_UNSPEC which
 789  * removes all address family entries.  Returns zero on success, negative on
 790  * failure.
 791  *
 792  */
 793 int netlbl_domhsh_remove(const char *domain, u16 family,
 794                          struct netlbl_audit *audit_info)
 795 {
 796         int ret_val = -EINVAL;
 797         struct netlbl_dom_map *entry;
 798 
 799         rcu_read_lock();
 800 
 801         if (family == AF_INET || family == AF_UNSPEC) {
 802                 if (domain)
 803                         entry = netlbl_domhsh_search(domain, AF_INET);
 804                 else
 805                         entry = netlbl_domhsh_search_def(domain, AF_INET);
 806                 ret_val = netlbl_domhsh_remove_entry(entry, audit_info);
 807                 if (ret_val && ret_val != -ENOENT)
 808                         goto done;
 809         }
 810         if (family == AF_INET6 || family == AF_UNSPEC) {
 811                 int ret_val2;
 812 
 813                 if (domain)
 814                         entry = netlbl_domhsh_search(domain, AF_INET6);
 815                 else
 816                         entry = netlbl_domhsh_search_def(domain, AF_INET6);
 817                 ret_val2 = netlbl_domhsh_remove_entry(entry, audit_info);
 818                 if (ret_val2 != -ENOENT)
 819                         ret_val = ret_val2;
 820         }
 821 done:
 822         rcu_read_unlock();
 823 
 824         return ret_val;
 825 }
 826 
 827 /**
 828  * netlbl_domhsh_remove_default - Removes the default entry from the table
 829  * @family: address family
 830  * @audit_info: NetLabel audit information
 831  *
 832  * Description:
 833  * Removes/resets the default entry corresponding to @family from the domain
 834  * hash table and handles any updates to the lower level protocol handler
 835  * (i.e. CIPSO).  @family may be %AF_UNSPEC which removes all address family
 836  * entries.  Returns zero on success, negative on failure.
 837  *
 838  */
 839 int netlbl_domhsh_remove_default(u16 family, struct netlbl_audit *audit_info)
 840 {
 841         return netlbl_domhsh_remove(NULL, family, audit_info);
 842 }
 843 
 844 /**
 845  * netlbl_domhsh_getentry - Get an entry from the domain hash table
 846  * @domain: the domain name to search for
 847  * @family: address family
 848  *
 849  * Description:
 850  * Look through the domain hash table searching for an entry to match @domain,
 851  * with address family @family, return a pointer to a copy of the entry or
 852  * NULL.  The caller is responsible for ensuring that rcu_read_[un]lock() is
 853  * called.
 854  *
 855  */
 856 struct netlbl_dom_map *netlbl_domhsh_getentry(const char *domain, u16 family)
 857 {
 858         if (family == AF_UNSPEC)
 859                 return NULL;
 860         return netlbl_domhsh_search_def(domain, family);
 861 }
 862 
 863 /**
 864  * netlbl_domhsh_getentry_af4 - Get an entry from the domain hash table
 865  * @domain: the domain name to search for
 866  * @addr: the IP address to search for
 867  *
 868  * Description:
 869  * Look through the domain hash table searching for an entry to match @domain
 870  * and @addr, return a pointer to a copy of the entry or NULL.  The caller is
 871  * responsible for ensuring that rcu_read_[un]lock() is called.
 872  *
 873  */
 874 struct netlbl_dommap_def *netlbl_domhsh_getentry_af4(const char *domain,
 875                                                      __be32 addr)
 876 {
 877         struct netlbl_dom_map *dom_iter;
 878         struct netlbl_af4list *addr_iter;
 879 
 880         dom_iter = netlbl_domhsh_search_def(domain, AF_INET);
 881         if (dom_iter == NULL)
 882                 return NULL;
 883 
 884         if (dom_iter->def.type != NETLBL_NLTYPE_ADDRSELECT)
 885                 return &dom_iter->def;
 886         addr_iter = netlbl_af4list_search(addr, &dom_iter->def.addrsel->list4);
 887         if (addr_iter == NULL)
 888                 return NULL;
 889         return &(netlbl_domhsh_addr4_entry(addr_iter)->def);
 890 }
 891 
 892 #if IS_ENABLED(CONFIG_IPV6)
 893 /**
 894  * netlbl_domhsh_getentry_af6 - Get an entry from the domain hash table
 895  * @domain: the domain name to search for
 896  * @addr: the IP address to search for
 897  *
 898  * Description:
 899  * Look through the domain hash table searching for an entry to match @domain
 900  * and @addr, return a pointer to a copy of the entry or NULL.  The caller is
 901  * responsible for ensuring that rcu_read_[un]lock() is called.
 902  *
 903  */
 904 struct netlbl_dommap_def *netlbl_domhsh_getentry_af6(const char *domain,
 905                                                    const struct in6_addr *addr)
 906 {
 907         struct netlbl_dom_map *dom_iter;
 908         struct netlbl_af6list *addr_iter;
 909 
 910         dom_iter = netlbl_domhsh_search_def(domain, AF_INET6);
 911         if (dom_iter == NULL)
 912                 return NULL;
 913 
 914         if (dom_iter->def.type != NETLBL_NLTYPE_ADDRSELECT)
 915                 return &dom_iter->def;
 916         addr_iter = netlbl_af6list_search(addr, &dom_iter->def.addrsel->list6);
 917         if (addr_iter == NULL)
 918                 return NULL;
 919         return &(netlbl_domhsh_addr6_entry(addr_iter)->def);
 920 }
 921 #endif /* IPv6 */
 922 
 923 /**
 924  * netlbl_domhsh_walk - Iterate through the domain mapping hash table
 925  * @skip_bkt: the number of buckets to skip at the start
 926  * @skip_chain: the number of entries to skip in the first iterated bucket
 927  * @callback: callback for each entry
 928  * @cb_arg: argument for the callback function
 929  *
 930  * Description:
 931  * Interate over the domain mapping hash table, skipping the first @skip_bkt
 932  * buckets and @skip_chain entries.  For each entry in the table call
 933  * @callback, if @callback returns a negative value stop 'walking' through the
 934  * table and return.  Updates the values in @skip_bkt and @skip_chain on
 935  * return.  Returns zero on success, negative values on failure.
 936  *
 937  */
 938 int netlbl_domhsh_walk(u32 *skip_bkt,
 939                      u32 *skip_chain,
 940                      int (*callback) (struct netlbl_dom_map *entry, void *arg),
 941                      void *cb_arg)
 942 {
 943         int ret_val = -ENOENT;
 944         u32 iter_bkt;
 945         struct list_head *iter_list;
 946         struct netlbl_dom_map *iter_entry;
 947         u32 chain_cnt = 0;
 948 
 949         rcu_read_lock();
 950         for (iter_bkt = *skip_bkt;
 951              iter_bkt < rcu_dereference(netlbl_domhsh)->size;
 952              iter_bkt++, chain_cnt = 0) {
 953                 iter_list = &rcu_dereference(netlbl_domhsh)->tbl[iter_bkt];
 954                 list_for_each_entry_rcu(iter_entry, iter_list, list)
 955                         if (iter_entry->valid) {
 956                                 if (chain_cnt++ < *skip_chain)
 957                                         continue;
 958                                 ret_val = callback(iter_entry, cb_arg);
 959                                 if (ret_val < 0) {
 960                                         chain_cnt--;
 961                                         goto walk_return;
 962                                 }
 963                         }
 964         }
 965 
 966 walk_return:
 967         rcu_read_unlock();
 968         *skip_bkt = iter_bkt;
 969         *skip_chain = chain_cnt;
 970         return ret_val;
 971 }