net/netlabel/netlabel_domainhash.c

   1 /*
   2  * NetLabel Domain Hash Table
   3  *
   4  * This file manages the domain hash table that NetLabel uses to determine
   5  * which network labeling protocol to use for a given domain.  The NetLabel
   6  * system manages static and dynamic label mappings for network protocols such
   7  * as CIPSO and RIPSO.
   8  *
   9  * Author: Paul Moore <paul@paul-moore.com>
  10  *
  11  */
  12
  13 /*
  14  * (c) Copyright Hewlett-Packard Development Company, L.P., 2006, 2008
  15  *
  16  * This program is free software;  you can redistribute it and/or modify
  17  * it under the terms of the GNU General Public License as published by
  18  * the Free Software Foundation; either version 2 of the License, or
  19  * (at your option) any later version.
  20  *
  21  * This program is distributed in the hope that it will be useful,
  22  * but WITHOUT ANY WARRANTY;  without even the implied warranty of
  23  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See
  24  * the GNU General Public License for more details.
  25  *
  26  * You should have received a copy of the GNU General Public License
  27  * along with this program;  if not, write to the Free Software
  28  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
  29  *
  30  */
  31
  32 #include <linux/types.h>
  33 #include <linux/rculist.h>
  34 #include <linux/skbuff.h>
  35 #include <linux/spinlock.h>
  36 #include <linux/string.h>
  37 #include <linux/audit.h>
  38 #include <linux/slab.h>
  39 #include <net/netlabel.h>
  40 #include <net/cipso_ipv4.h>
  41 #include <asm/bug.h>
  42
  43 #include "netlabel_mgmt.h"
  44 #include "netlabel_addrlist.h"
  45 #include "netlabel_domainhash.h"
  46 #include "netlabel_user.h"
  47
  48 struct netlbl_domhsh_tbl {
  49         struct list_head *tbl;
  50         u32 size;
  51 };
  52
  53 /* Domain hash table */
  54 /* updates should be so rare that having one spinlock for the entire hash table
  55  * should be okay */
  56 static DEFINE_SPINLOCK(netlbl_domhsh_lock);
  57 #define netlbl_domhsh_rcu_deref(p) \
  58         rcu_dereference_check(p, lockdep_is_held(&netlbl_domhsh_lock))
  59 static struct netlbl_domhsh_tbl *netlbl_domhsh = NULL;
  60 static struct netlbl_dom_map *netlbl_domhsh_def = NULL;
  61
  62 /*
  63  * Domain Hash Table Helper Functions
  64  */
  65
  66 /**
  67  * netlbl_domhsh_free_entry - Frees a domain hash table entry
  68  * @entry: the entry's RCU field
  69  *
  70  * Description:
  71  * This function is designed to be used as a callback to the call_rcu()
  72  * function so that the memory allocated to a hash table entry can be released
  73  * safely.
  74  *
  75  */
  76 static void netlbl_domhsh_free_entry(struct rcu_head *entry)
  77 {
  78         struct netlbl_dom_map *ptr;
  79         struct netlbl_af4list *iter4;
  80         struct netlbl_af4list *tmp4;
  81 #if IS_ENABLED(CONFIG_IPV6)
  82         struct netlbl_af6list *iter6;
  83         struct netlbl_af6list *tmp6;
  84 #endif /* IPv6 */
  85
  86         ptr = container_of(entry, struct netlbl_dom_map, rcu);
  87         if (ptr->type == NETLBL_NLTYPE_ADDRSELECT) {
  88                 netlbl_af4list_foreach_safe(iter4, tmp4,
  89                                             &ptr->type_def.addrsel->list4) {
  90                         netlbl_af4list_remove_entry(iter4);
  91                         kfree(netlbl_domhsh_addr4_entry(iter4));
  92                 }
  93 #if IS_ENABLED(CONFIG_IPV6)
  94                 netlbl_af6list_foreach_safe(iter6, tmp6,
  95                                             &ptr->type_def.addrsel->list6) {
  96                         netlbl_af6list_remove_entry(iter6);
  97                         kfree(netlbl_domhsh_addr6_entry(iter6));
  98                 }
  99 #endif /* IPv6 */
 100         }
 101         kfree(ptr->domain);
 102         kfree(ptr);
 103 }
 104
 105 /**
 106  * netlbl_domhsh_hash - Hashing function for the domain hash table
 107  * @domain: the domain name to hash
 108  *
 109  * Description:
 110  * This is the hashing function for the domain hash table, it returns the
 111  * correct bucket number for the domain.  The caller is responsible for
 112  * ensuring that the hash table is protected with either a RCU read lock or the
 113  * hash table lock.
 114  *
 115  */
 116 static u32 netlbl_domhsh_hash(const char *key)
 117 {
 118         u32 iter;
 119         u32 val;
 120         u32 len;
 121
 122         /* This is taken (with slight modification) from
 123          * security/selinux/ss/symtab.c:symhash() */
 124
 125         for (iter = 0, val = 0, len = strlen(key); iter < len; iter++)
 126                 val = (val << 4 | (val >> (8 * sizeof(u32) - 4))) ^ key[iter];
 127         return val & (netlbl_domhsh_rcu_deref(netlbl_domhsh)->size - 1);
 128 }
 129
 130 /**
 131  * netlbl_domhsh_search - Search for a domain entry
 132  * @domain: the domain
 133  *
 134  * Description:
 135  * Searches the domain hash table and returns a pointer to the hash table
 136  * entry if found, otherwise NULL is returned.  The caller is responsible for
 137  * ensuring that the hash table is protected with either a RCU read lock or the
 138  * hash table lock.
 139  *
 140  */
 141 static struct netlbl_dom_map *netlbl_domhsh_search(const char *domain)
 142 {
 143         u32 bkt;
 144         struct list_head *bkt_list;
 145         struct netlbl_dom_map *iter;
 146
 147         if (domain != NULL) {
 148                 bkt = netlbl_domhsh_hash(domain);
 149                 bkt_list = &netlbl_domhsh_rcu_deref(netlbl_domhsh)->tbl[bkt];
 150                 list_for_each_entry_rcu(iter, bkt_list, list)
 151                         if (iter->valid && strcmp(iter->domain, domain) == 0)
 152                                 return iter;
 153         }
 154
 155         return NULL;
 156 }
 157
 158 /**
 159  * netlbl_domhsh_search_def - Search for a domain entry
 160  * @domain: the domain
 161  * @def: return default if no match is found
 162  *
 163  * Description:
 164  * Searches the domain hash table and returns a pointer to the hash table
 165  * entry if an exact match is found, if an exact match is not present in the
 166  * hash table then the default entry is returned if valid otherwise NULL is
 167  * returned.  The caller is responsible ensuring that the hash table is
 168  * protected with either a RCU read lock or the hash table lock.
 169  *
 170  */
 171 static struct netlbl_dom_map *netlbl_domhsh_search_def(const char *domain)
 172 {
 173         struct netlbl_dom_map *entry;
 174
 175         entry = netlbl_domhsh_search(domain);
 176         if (entry == NULL) {
 177                 entry = netlbl_domhsh_rcu_deref(netlbl_domhsh_def);
 178                 if (entry != NULL && !entry->valid)
 179                         entry = NULL;
 180         }
 181
 182         return entry;
 183 }
 184
 185 /**
 186  * netlbl_domhsh_audit_add - Generate an audit entry for an add event
 187  * @entry: the entry being added
 188  * @addr4: the IPv4 address information
 189  * @addr6: the IPv6 address information
 190  * @result: the result code
 191  * @audit_info: NetLabel audit information
 192  *
 193  * Description:
 194  * Generate an audit record for adding a new NetLabel/LSM mapping entry with
 195  * the given information.  Caller is responsible for holding the necessary
 196  * locks.
 197  *
 198  */
 199 static void netlbl_domhsh_audit_add(struct netlbl_dom_map *entry,
 200                                     struct netlbl_af4list *addr4,
 201                                     struct netlbl_af6list *addr6,
 202                                     int result,
 203                                     struct netlbl_audit *audit_info)
 204 {
 205         struct audit_buffer *audit_buf;
 206         struct cipso_v4_doi *cipsov4 = NULL;
 207         u32 type;
 208
 209         audit_buf = netlbl_audit_start_common(AUDIT_MAC_MAP_ADD, audit_info);
 210         if (audit_buf != NULL) {
 211                 audit_log_format(audit_buf, " nlbl_domain=%s",
 212                                  entry->domain ? entry->domain : "(default)");
 213                 if (addr4 != NULL) {
 214                         struct netlbl_domaddr4_map *map4;
 215                         map4 = netlbl_domhsh_addr4_entry(addr4);
 216                         type = map4->type;
 217                         cipsov4 = map4->type_def.cipsov4;
 218                         netlbl_af4list_audit_addr(audit_buf, 0, NULL,
 219                                                   addr4->addr, addr4->mask);
 220 #if IS_ENABLED(CONFIG_IPV6)
 221                 } else if (addr6 != NULL) {
 222                         struct netlbl_domaddr6_map *map6;
 223                         map6 = netlbl_domhsh_addr6_entry(addr6);
 224                         type = map6->type;
 225                         netlbl_af6list_audit_addr(audit_buf, 0, NULL,
 226                                                   &addr6->addr, &addr6->mask);
 227 #endif /* IPv6 */
 228                 } else {
 229                         type = entry->type;
 230                         cipsov4 = entry->type_def.cipsov4;
 231                 }
 232                 switch (type) {
 233                 case NETLBL_NLTYPE_UNLABELED:
 234                         audit_log_format(audit_buf, " nlbl_protocol=unlbl");
 235                         break;
 236                 case NETLBL_NLTYPE_CIPSOV4:
 237                         BUG_ON(cipsov4 == NULL);
 238                         audit_log_format(audit_buf,
 239                                          " nlbl_protocol=cipsov4 cipso_doi=%u",
 240                                          cipsov4->doi);
 241                         break;
 242                 }
 243                 audit_log_format(audit_buf, " res=%u", result == 0 ? 1 : 0);
 244                 audit_log_end(audit_buf);
 245         }
 246 }
 247
 248 /**
 249  * netlbl_domhsh_validate - Validate a new domain mapping entry
 250  * @entry: the entry to validate
 251  *
 252  * This function validates the new domain mapping entry to ensure that it is
 253  * a valid entry.  Returns zero on success, negative values on failure.
 254  *
 255  */
 256 static int netlbl_domhsh_validate(const struct netlbl_dom_map *entry)
 257 {
 258         struct netlbl_af4list *iter4;
 259         struct netlbl_domaddr4_map *map4;
 260 #if IS_ENABLED(CONFIG_IPV6)
 261         struct netlbl_af6list *iter6;
 262         struct netlbl_domaddr6_map *map6;
 263 #endif /* IPv6 */
 264
 265         if (entry == NULL)
 266                 return -EINVAL;
 267
 268         switch (entry->type) {
 269         case NETLBL_NLTYPE_UNLABELED:
 270                 if (entry->type_def.cipsov4 != NULL ||
 271                     entry->type_def.addrsel != NULL)
 272                         return -EINVAL;
 273                 break;
 274         case NETLBL_NLTYPE_CIPSOV4:
 275                 if (entry->type_def.cipsov4 == NULL)
 276                         return -EINVAL;
 277                 break;
 278         case NETLBL_NLTYPE_ADDRSELECT:
 279                 netlbl_af4list_foreach(iter4, &entry->type_def.addrsel->list4) {
 280                         map4 = netlbl_domhsh_addr4_entry(iter4);
 281                         switch (map4->type) {
 282                         case NETLBL_NLTYPE_UNLABELED:
 283                                 if (map4->type_def.cipsov4 != NULL)
 284                                         return -EINVAL;
 285                                 break;
 286                         case NETLBL_NLTYPE_CIPSOV4:
 287                                 if (map4->type_def.cipsov4 == NULL)
 288                                         return -EINVAL;
 289                                 break;
 290                         default:
 291                                 return -EINVAL;
 292                         }
 293                 }
 294 #if IS_ENABLED(CONFIG_IPV6)
 295                 netlbl_af6list_foreach(iter6, &entry->type_def.addrsel->list6) {
 296                         map6 = netlbl_domhsh_addr6_entry(iter6);
 297                         switch (map6->type) {
 298                         case NETLBL_NLTYPE_UNLABELED:
 299                                 break;
 300                         default:
 301                                 return -EINVAL;
 302                         }
 303                 }
 304 #endif /* IPv6 */
 305                 break;
 306         default:
 307                 return -EINVAL;
 308         }
 309
 310         return 0;
 311 }
 312
 313 /*
 314  * Domain Hash Table Functions
 315  */
 316
 317 /**
 318  * netlbl_domhsh_init - Init for the domain hash
 319  * @size: the number of bits to use for the hash buckets
 320  *
 321  * Description:
 322  * Initializes the domain hash table, should be called only by
 323  * netlbl_user_init() during initialization.  Returns zero on success, non-zero
 324  * values on error.
 325  *
 326  */
 327 int __init netlbl_domhsh_init(u32 size)
 328 {
 329         u32 iter;
 330         struct netlbl_domhsh_tbl *hsh_tbl;
 331
 332         if (size == 0)
 333                 return -EINVAL;
 334
 335         hsh_tbl = kmalloc(sizeof(*hsh_tbl), GFP_KERNEL);
 336         if (hsh_tbl == NULL)
 337                 return -ENOMEM;
 338         hsh_tbl->size = 1 << size;
 339         hsh_tbl->tbl = kcalloc(hsh_tbl->size,
 340                                sizeof(struct list_head),
 341                                GFP_KERNEL);
 342         if (hsh_tbl->tbl == NULL) {
 343                 kfree(hsh_tbl);
 344                 return -ENOMEM;
 345         }
 346         for (iter = 0; iter < hsh_tbl->size; iter++)
 347                 INIT_LIST_HEAD(&hsh_tbl->tbl[iter]);
 348
 349         spin_lock(&netlbl_domhsh_lock);
 350         rcu_assign_pointer(netlbl_domhsh, hsh_tbl);
 351         spin_unlock(&netlbl_domhsh_lock);
 352
 353         return 0;
 354 }
 355
 356 /**
 357  * netlbl_domhsh_add - Adds a entry to the domain hash table
 358  * @entry: the entry to add
 359  * @audit_info: NetLabel audit information
 360  *
 361  * Description:
 362  * Adds a new entry to the domain hash table and handles any updates to the
 363  * lower level protocol handler (i.e. CIPSO).  Returns zero on success,
 364  * negative on failure.
 365  *
 366  */
 367 int netlbl_domhsh_add(struct netlbl_dom_map *entry,
 368                       struct netlbl_audit *audit_info)
 369 {
 370         int ret_val = 0;
 371         struct netlbl_dom_map *entry_old;
 372         struct netlbl_af4list *iter4;
 373         struct netlbl_af4list *tmp4;
 374 #if IS_ENABLED(CONFIG_IPV6)
 375         struct netlbl_af6list *iter6;
 376         struct netlbl_af6list *tmp6;
 377 #endif /* IPv6 */
 378
 379         ret_val = netlbl_domhsh_validate(entry);
 380         if (ret_val != 0)
 381                 return ret_val;
 382
 383         /* XXX - we can remove this RCU read lock as the spinlock protects the
 384          *       entire function, but before we do we need to fixup the
 385          *       netlbl_af[4,6]list RCU functions to do "the right thing" with
 386          *       respect to rcu_dereference() when only a spinlock is held. */
 387         rcu_read_lock();
 388         spin_lock(&netlbl_domhsh_lock);
 389         if (entry->domain != NULL)
 390                 entry_old = netlbl_domhsh_search(entry->domain);
 391         else
 392                 entry_old = netlbl_domhsh_search_def(entry->domain);
 393         if (entry_old == NULL) {
 394                 entry->valid = 1;
 395
 396                 if (entry->domain != NULL) {
 397                         u32 bkt = netlbl_domhsh_hash(entry->domain);
 398                         list_add_tail_rcu(&entry->list,
 399                                     &rcu_dereference(netlbl_domhsh)->tbl[bkt]);
 400                 } else {
 401                         INIT_LIST_HEAD(&entry->list);
 402                         rcu_assign_pointer(netlbl_domhsh_def, entry);
 403                 }
 404
 405                 if (entry->type == NETLBL_NLTYPE_ADDRSELECT) {
 406                         netlbl_af4list_foreach_rcu(iter4,
 407                                                &entry->type_def.addrsel->list4)
 408                                 netlbl_domhsh_audit_add(entry, iter4, NULL,
 409                                                         ret_val, audit_info);
 410 #if IS_ENABLED(CONFIG_IPV6)
 411                         netlbl_af6list_foreach_rcu(iter6,
 412                                                &entry->type_def.addrsel->list6)
 413                                 netlbl_domhsh_audit_add(entry, NULL, iter6,
 414                                                         ret_val, audit_info);
 415 #endif /* IPv6 */
 416                 } else
 417                         netlbl_domhsh_audit_add(entry, NULL, NULL,
 418                                                 ret_val, audit_info);
 419         } else if (entry_old->type == NETLBL_NLTYPE_ADDRSELECT &&
 420                    entry->type == NETLBL_NLTYPE_ADDRSELECT) {
 421                 struct list_head *old_list4;
 422                 struct list_head *old_list6;
 423
 424                 old_list4 = &entry_old->type_def.addrsel->list4;
 425                 old_list6 = &entry_old->type_def.addrsel->list6;
 426
 427                 /* we only allow the addition of address selectors if all of
 428                  * the selectors do not exist in the existing domain map */
 429                 netlbl_af4list_foreach_rcu(iter4,
 430                                            &entry->type_def.addrsel->list4)
 431                         if (netlbl_af4list_search_exact(iter4->addr,
 432                                                         iter4->mask,
 433                                                         old_list4)) {
 434                                 ret_val = -EEXIST;
 435                                 goto add_return;
 436                         }
 437 #if IS_ENABLED(CONFIG_IPV6)
 438                 netlbl_af6list_foreach_rcu(iter6,
 439                                            &entry->type_def.addrsel->list6)
 440                         if (netlbl_af6list_search_exact(&iter6->addr,
 441                                                         &iter6->mask,
 442                                                         old_list6)) {
 443                                 ret_val = -EEXIST;
 444                                 goto add_return;
 445                         }
 446 #endif /* IPv6 */
 447
 448                 netlbl_af4list_foreach_safe(iter4, tmp4,
 449                                             &entry->type_def.addrsel->list4) {
 450                         netlbl_af4list_remove_entry(iter4);
 451                         iter4->valid = 1;
 452                         ret_val = netlbl_af4list_add(iter4, old_list4);
 453                         netlbl_domhsh_audit_add(entry_old, iter4, NULL,
 454                                                 ret_val, audit_info);
 455                         if (ret_val != 0)
 456                                 goto add_return;
 457                 }
 458 #if IS_ENABLED(CONFIG_IPV6)
 459                 netlbl_af6list_foreach_safe(iter6, tmp6,
 460                                             &entry->type_def.addrsel->list6) {
 461                         netlbl_af6list_remove_entry(iter6);
 462                         iter6->valid = 1;
 463                         ret_val = netlbl_af6list_add(iter6, old_list6);
 464                         netlbl_domhsh_audit_add(entry_old, NULL, iter6,
 465                                                 ret_val, audit_info);
 466                         if (ret_val != 0)
 467                                 goto add_return;
 468                 }
 469 #endif /* IPv6 */
 470         } else
 471                 ret_val = -EINVAL;
 472
 473 add_return:
 474         spin_unlock(&netlbl_domhsh_lock);
 475         rcu_read_unlock();
 476         return ret_val;
 477 }
 478
 479 /**
 480  * netlbl_domhsh_add_default - Adds the default entry to the domain hash table
 481  * @entry: the entry to add
 482  * @audit_info: NetLabel audit information
 483  *
 484  * Description:
 485  * Adds a new default entry to the domain hash table and handles any updates
 486  * to the lower level protocol handler (i.e. CIPSO).  Returns zero on success,
 487  * negative on failure.
 488  *
 489  */
 490 int netlbl_domhsh_add_default(struct netlbl_dom_map *entry,
 491                               struct netlbl_audit *audit_info)
 492 {
 493         return netlbl_domhsh_add(entry, audit_info);
 494 }
 495
 496 /**
 497  * netlbl_domhsh_remove_entry - Removes a given entry from the domain table
 498  * @entry: the entry to remove
 499  * @audit_info: NetLabel audit information
 500  *
 501  * Description:
 502  * Removes an entry from the domain hash table and handles any updates to the
 503  * lower level protocol handler (i.e. CIPSO).  Caller is responsible for
 504  * ensuring that the RCU read lock is held.  Returns zero on success, negative
 505  * on failure.
 506  *
 507  */
 508 int netlbl_domhsh_remove_entry(struct netlbl_dom_map *entry,
 509                                struct netlbl_audit *audit_info)
 510 {
 511         int ret_val = 0;
 512         struct audit_buffer *audit_buf;
 513
 514         if (entry == NULL)
 515                 return -ENOENT;
 516
 517         spin_lock(&netlbl_domhsh_lock);
 518         if (entry->valid) {
 519                 entry->valid = 0;
 520                 if (entry != rcu_dereference(netlbl_domhsh_def))
 521                         list_del_rcu(&entry->list);
 522                 else
 523                         RCU_INIT_POINTER(netlbl_domhsh_def, NULL);
 524         } else
 525                 ret_val = -ENOENT;
 526         spin_unlock(&netlbl_domhsh_lock);
 527
 528         audit_buf = netlbl_audit_start_common(AUDIT_MAC_MAP_DEL, audit_info);
 529         if (audit_buf != NULL) {
 530                 audit_log_format(audit_buf,
 531                                  " nlbl_domain=%s res=%u",
 532                                  entry->domain ? entry->domain : "(default)",
 533                                  ret_val == 0 ? 1 : 0);
 534                 audit_log_end(audit_buf);
 535         }
 536
 537         if (ret_val == 0) {
 538                 struct netlbl_af4list *iter4;
 539                 struct netlbl_domaddr4_map *map4;
 540
 541                 switch (entry->type) {
 542                 case NETLBL_NLTYPE_ADDRSELECT:
 543                         netlbl_af4list_foreach_rcu(iter4,
 544                                              &entry->type_def.addrsel->list4) {
 545                                 map4 = netlbl_domhsh_addr4_entry(iter4);
 546                                 cipso_v4_doi_putdef(map4->type_def.cipsov4);
 547                         }
 548                         /* no need to check the IPv6 list since we currently
 549                          * support only unlabeled protocols for IPv6 */
 550                         break;
 551                 case NETLBL_NLTYPE_CIPSOV4:
 552                         cipso_v4_doi_putdef(entry->type_def.cipsov4);
 553                         break;
 554                 }
 555                 call_rcu(&entry->rcu, netlbl_domhsh_free_entry);
 556         }
 557
 558         return ret_val;
 559 }
 560
 561 /**
 562  * netlbl_domhsh_remove_af4 - Removes an address selector entry
 563  * @domain: the domain
 564  * @addr: IPv4 address
 565  * @mask: IPv4 address mask
 566  * @audit_info: NetLabel audit information
 567  *
 568  * Description:
 569  * Removes an individual address selector from a domain mapping and potentially
 570  * the entire mapping if it is empty.  Returns zero on success, negative values
 571  * on failure.
 572  *
 573  */
 574 int netlbl_domhsh_remove_af4(const char *domain,
 575                              const struct in_addr *addr,
 576                              const struct in_addr *mask,
 577                              struct netlbl_audit *audit_info)
 578 {
 579         struct netlbl_dom_map *entry_map;
 580         struct netlbl_af4list *entry_addr;
 581         struct netlbl_af4list *iter4;
 582 #if IS_ENABLED(CONFIG_IPV6)
 583         struct netlbl_af6list *iter6;
 584 #endif /* IPv6 */
 585         struct netlbl_domaddr4_map *entry;
 586
 587         rcu_read_lock();
 588
 589         if (domain)
 590                 entry_map = netlbl_domhsh_search(domain);
 591         else
 592                 entry_map = netlbl_domhsh_search_def(domain);
 593         if (entry_map == NULL || entry_map->type != NETLBL_NLTYPE_ADDRSELECT)
 594                 goto remove_af4_failure;
 595
 596         spin_lock(&netlbl_domhsh_lock);
 597         entry_addr = netlbl_af4list_remove(addr->s_addr, mask->s_addr,
 598                                            &entry_map->type_def.addrsel->list4);
 599         spin_unlock(&netlbl_domhsh_lock);
 600
 601         if (entry_addr == NULL)
 602                 goto remove_af4_failure;
 603         netlbl_af4list_foreach_rcu(iter4, &entry_map->type_def.addrsel->list4)
 604                 goto remove_af4_single_addr;
 605 #if IS_ENABLED(CONFIG_IPV6)
 606         netlbl_af6list_foreach_rcu(iter6, &entry_map->type_def.addrsel->list6)
 607                 goto remove_af4_single_addr;
 608 #endif /* IPv6 */
 609         /* the domain mapping is empty so remove it from the mapping table */
 610         netlbl_domhsh_remove_entry(entry_map, audit_info);
 611
 612 remove_af4_single_addr:
 613         rcu_read_unlock();
 614         /* yick, we can't use call_rcu here because we don't have a rcu head
 615          * pointer but hopefully this should be a rare case so the pause
 616          * shouldn't be a problem */
 617         synchronize_rcu();
 618         entry = netlbl_domhsh_addr4_entry(entry_addr);
 619         cipso_v4_doi_putdef(entry->type_def.cipsov4);
 620         kfree(entry);
 621         return 0;
 622
 623 remove_af4_failure:
 624         rcu_read_unlock();
 625         return -ENOENT;
 626 }
 627
 628 /**
 629  * netlbl_domhsh_remove - Removes an entry from the domain hash table
 630  * @domain: the domain to remove
 631  * @audit_info: NetLabel audit information
 632  *
 633  * Description:
 634  * Removes an entry from the domain hash table and handles any updates to the
 635  * lower level protocol handler (i.e. CIPSO).  Returns zero on success,
 636  * negative on failure.
 637  *
 638  */
 639 int netlbl_domhsh_remove(const char *domain, struct netlbl_audit *audit_info)
 640 {
 641         int ret_val;
 642         struct netlbl_dom_map *entry;
 643
 644         rcu_read_lock();
 645         if (domain)
 646                 entry = netlbl_domhsh_search(domain);
 647         else
 648                 entry = netlbl_domhsh_search_def(domain);
 649         ret_val = netlbl_domhsh_remove_entry(entry, audit_info);
 650         rcu_read_unlock();
 651
 652         return ret_val;
 653 }
 654
 655 /**
 656  * netlbl_domhsh_remove_default - Removes the default entry from the table
 657  * @audit_info: NetLabel audit information
 658  *
 659  * Description:
 660  * Removes/resets the default entry for the domain hash table and handles any
 661  * updates to the lower level protocol handler (i.e. CIPSO).  Returns zero on
 662  * success, non-zero on failure.
 663  *
 664  */
 665 int netlbl_domhsh_remove_default(struct netlbl_audit *audit_info)
 666 {
 667         return netlbl_domhsh_remove(NULL, audit_info);
 668 }
 669
 670 /**
 671  * netlbl_domhsh_getentry - Get an entry from the domain hash table
 672  * @domain: the domain name to search for
 673  *
 674  * Description:
 675  * Look through the domain hash table searching for an entry to match @domain,
 676  * return a pointer to a copy of the entry or NULL.  The caller is responsible
 677  * for ensuring that rcu_read_[un]lock() is called.
 678  *
 679  */
 680 struct netlbl_dom_map *netlbl_domhsh_getentry(const char *domain)
 681 {
 682         return netlbl_domhsh_search_def(domain);
 683 }
 684
 685 /**
 686  * netlbl_domhsh_getentry_af4 - Get an entry from the domain hash table
 687  * @domain: the domain name to search for
 688  * @addr: the IP address to search for
 689  *
 690  * Description:
 691  * Look through the domain hash table searching for an entry to match @domain
 692  * and @addr, return a pointer to a copy of the entry or NULL.  The caller is
 693  * responsible for ensuring that rcu_read_[un]lock() is called.
 694  *
 695  */
 696 struct netlbl_domaddr4_map *netlbl_domhsh_getentry_af4(const char *domain,
 697                                                        __be32 addr)
 698 {
 699         struct netlbl_dom_map *dom_iter;
 700         struct netlbl_af4list *addr_iter;
 701
 702         dom_iter = netlbl_domhsh_search_def(domain);
 703         if (dom_iter == NULL)
 704                 return NULL;
 705         if (dom_iter->type != NETLBL_NLTYPE_ADDRSELECT)
 706                 return NULL;
 707
 708         addr_iter = netlbl_af4list_search(addr,
 709                                           &dom_iter->type_def.addrsel->list4);
 710         if (addr_iter == NULL)
 711                 return NULL;
 712
 713         return netlbl_domhsh_addr4_entry(addr_iter);
 714 }
 715
 716 #if IS_ENABLED(CONFIG_IPV6)
 717 /**
 718  * netlbl_domhsh_getentry_af6 - Get an entry from the domain hash table
 719  * @domain: the domain name to search for
 720  * @addr: the IP address to search for
 721  *
 722  * Description:
 723  * Look through the domain hash table searching for an entry to match @domain
 724  * and @addr, return a pointer to a copy of the entry or NULL.  The caller is
 725  * responsible for ensuring that rcu_read_[un]lock() is called.
 726  *
 727  */
 728 struct netlbl_domaddr6_map *netlbl_domhsh_getentry_af6(const char *domain,
 729                                                    const struct in6_addr *addr)
 730 {
 731         struct netlbl_dom_map *dom_iter;
 732         struct netlbl_af6list *addr_iter;
 733
 734         dom_iter = netlbl_domhsh_search_def(domain);
 735         if (dom_iter == NULL)
 736                 return NULL;
 737         if (dom_iter->type != NETLBL_NLTYPE_ADDRSELECT)
 738                 return NULL;
 739
 740         addr_iter = netlbl_af6list_search(addr,
 741                                           &dom_iter->type_def.addrsel->list6);
 742         if (addr_iter == NULL)
 743                 return NULL;
 744
 745         return netlbl_domhsh_addr6_entry(addr_iter);
 746 }
 747 #endif /* IPv6 */
 748
 749 /**
 750  * netlbl_domhsh_walk - Iterate through the domain mapping hash table
 751  * @skip_bkt: the number of buckets to skip at the start
 752  * @skip_chain: the number of entries to skip in the first iterated bucket
 753  * @callback: callback for each entry
 754  * @cb_arg: argument for the callback function
 755  *
 756  * Description:
 757  * Interate over the domain mapping hash table, skipping the first @skip_bkt
 758  * buckets and @skip_chain entries.  For each entry in the table call
 759  * @callback, if @callback returns a negative value stop 'walking' through the
 760  * table and return.  Updates the values in @skip_bkt and @skip_chain on
 761  * return.  Returns zero on success, negative values on failure.
 762  *
 763  */
 764 int netlbl_domhsh_walk(u32 *skip_bkt,
 765                      u32 *skip_chain,
 766                      int (*callback) (struct netlbl_dom_map *entry, void *arg),
 767                      void *cb_arg)
 768 {
 769         int ret_val = -ENOENT;
 770         u32 iter_bkt;
 771         struct list_head *iter_list;
 772         struct netlbl_dom_map *iter_entry;
 773         u32 chain_cnt = 0;
 774
 775         rcu_read_lock();
 776         for (iter_bkt = *skip_bkt;
 777              iter_bkt < rcu_dereference(netlbl_domhsh)->size;
 778              iter_bkt++, chain_cnt = 0) {
 779                 iter_list = &rcu_dereference(netlbl_domhsh)->tbl[iter_bkt];
 780                 list_for_each_entry_rcu(iter_entry, iter_list, list)
 781                         if (iter_entry->valid) {
 782                                 if (chain_cnt++ < *skip_chain)
 783                                         continue;
 784                                 ret_val = callback(iter_entry, cb_arg);
 785                                 if (ret_val < 0) {
 786                                         chain_cnt--;
 787                                         goto walk_return;
 788                                 }
 789                         }
 790         }
 791
 792 walk_return:
 793         rcu_read_unlock();
 794         *skip_bkt = iter_bkt;
 795         *skip_chain = chain_cnt;
 796         return ret_val;
 797 }