net/netlabel/netlabel_domainhash.c

   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                 kfree(ptr->def.addrsel);
  89         }
  90         kfree(ptr->domain);
  91         kfree(ptr);
  92 }
  93
  94 /**
  95  * netlbl_domhsh_hash - Hashing function for the domain hash table
  96  * @key: the domain name to hash
  97  *
  98  * Description:
  99  * This is the hashing function for the domain hash table, it returns the
 100  * correct bucket number for the domain.  The caller is responsible for
 101  * ensuring that the hash table is protected with either a RCU read lock or the
 102  * hash table lock.
 103  *
 104  */
 105 static u32 netlbl_domhsh_hash(const char *key)
 106 {
 107         u32 iter;
 108         u32 val;
 109         u32 len;
 110
 111         /* This is taken (with slight modification) from
 112          * security/selinux/ss/symtab.c:symhash() */
 113
 114         for (iter = 0, val = 0, len = strlen(key); iter < len; iter++)
 115                 val = (val << 4 | (val >> (8 * sizeof(u32) - 4))) ^ key[iter];
 116         return val & (netlbl_domhsh_rcu_deref(netlbl_domhsh)->size - 1);
 117 }
 118
 119 static bool netlbl_family_match(u16 f1, u16 f2)
 120 {
 121         return (f1 == f2) || (f1 == AF_UNSPEC) || (f2 == AF_UNSPEC);
 122 }
 123
 124 /**
 125  * netlbl_domhsh_search - Search for a domain entry
 126  * @domain: the domain
 127  * @family: the address family
 128  *
 129  * Description:
 130  * Searches the domain hash table and returns a pointer to the hash table
 131  * entry if found, otherwise NULL is returned.  @family may be %AF_UNSPEC
 132  * which matches any address family entries.  The caller is responsible for
 133  * ensuring that the hash table is protected with either a RCU read lock or the
 134  * hash table lock.
 135  *
 136  */
 137 static struct netlbl_dom_map *netlbl_domhsh_search(const char *domain,
 138                                                    u16 family)
 139 {
 140         u32 bkt;
 141         struct list_head *bkt_list;
 142         struct netlbl_dom_map *iter;
 143
 144         if (domain != NULL) {
 145                 bkt = netlbl_domhsh_hash(domain);
 146                 bkt_list = &netlbl_domhsh_rcu_deref(netlbl_domhsh)->tbl[bkt];
 147                 list_for_each_entry_rcu(iter, bkt_list, list,
 148                                         lockdep_is_held(&netlbl_domhsh_lock))
 149                         if (iter->valid &&
 150                             netlbl_family_match(iter->family, family) &&
 151                             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  * @family: the address family
 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.  @family may be %AF_UNSPEC which matches any address family
 168  * entries.  The caller is responsible ensuring that the hash table is
 169  * protected with either a RCU read lock or the hash table lock.
 170  *
 171  */
 172 static struct netlbl_dom_map *netlbl_domhsh_search_def(const char *domain,
 173                                                        u16 family)
 174 {
 175         struct netlbl_dom_map *entry;
 176
 177         entry = netlbl_domhsh_search(domain, family);
 178         if (entry != NULL)
 179                 return entry;
 180         if (family == AF_INET || family == AF_UNSPEC) {
 181                 entry = netlbl_domhsh_rcu_deref(netlbl_domhsh_def_ipv4);
 182                 if (entry != NULL && entry->valid)
 183                         return entry;
 184         }
 185         if (family == AF_INET6 || family == AF_UNSPEC) {
 186                 entry = netlbl_domhsh_rcu_deref(netlbl_domhsh_def_ipv6);
 187                 if (entry != NULL && entry->valid)
 188                         return entry;
 189         }
 190
 191         return NULL;
 192 }
 193
 194 /**
 195  * netlbl_domhsh_audit_add - Generate an audit entry for an add event
 196  * @entry: the entry being added
 197  * @addr4: the IPv4 address information
 198  * @addr6: the IPv6 address information
 199  * @result: the result code
 200  * @audit_info: NetLabel audit information
 201  *
 202  * Description:
 203  * Generate an audit record for adding a new NetLabel/LSM mapping entry with
 204  * the given information.  Caller is responsible for holding the necessary
 205  * locks.
 206  *
 207  */
 208 static void netlbl_domhsh_audit_add(struct netlbl_dom_map *entry,
 209                                     struct netlbl_af4list *addr4,
 210                                     struct netlbl_af6list *addr6,
 211                                     int result,
 212                                     struct netlbl_audit *audit_info)
 213 {
 214         struct audit_buffer *audit_buf;
 215         struct cipso_v4_doi *cipsov4 = NULL;
 216         struct calipso_doi *calipso = NULL;
 217         u32 type;
 218
 219         audit_buf = netlbl_audit_start_common(AUDIT_MAC_MAP_ADD, audit_info);
 220         if (audit_buf != NULL) {
 221                 audit_log_format(audit_buf, " nlbl_domain=%s",
 222                                  entry->domain ? entry->domain : "(default)");
 223                 if (addr4 != NULL) {
 224                         struct netlbl_domaddr4_map *map4;
 225                         map4 = netlbl_domhsh_addr4_entry(addr4);
 226                         type = map4->def.type;
 227                         cipsov4 = map4->def.cipso;
 228                         netlbl_af4list_audit_addr(audit_buf, 0, NULL,
 229                                                   addr4->addr, addr4->mask);
 230 #if IS_ENABLED(CONFIG_IPV6)
 231                 } else if (addr6 != NULL) {
 232                         struct netlbl_domaddr6_map *map6;
 233                         map6 = netlbl_domhsh_addr6_entry(addr6);
 234                         type = map6->def.type;
 235                         calipso = map6->def.calipso;
 236                         netlbl_af6list_audit_addr(audit_buf, 0, NULL,
 237                                                   &addr6->addr, &addr6->mask);
 238 #endif /* IPv6 */
 239                 } else {
 240                         type = entry->def.type;
 241                         cipsov4 = entry->def.cipso;
 242                         calipso = entry->def.calipso;
 243                 }
 244                 switch (type) {
 245                 case NETLBL_NLTYPE_UNLABELED:
 246                         audit_log_format(audit_buf, " nlbl_protocol=unlbl");
 247                         break;
 248                 case NETLBL_NLTYPE_CIPSOV4:
 249                         BUG_ON(cipsov4 == NULL);
 250                         audit_log_format(audit_buf,
 251                                          " nlbl_protocol=cipsov4 cipso_doi=%u",
 252                                          cipsov4->doi);
 253                         break;
 254                 case NETLBL_NLTYPE_CALIPSO:
 255                         BUG_ON(calipso == NULL);
 256                         audit_log_format(audit_buf,
 257                                          " nlbl_protocol=calipso calipso_doi=%u",
 258                                          calipso->doi);
 259                         break;
 260                 }
 261                 audit_log_format(audit_buf, " res=%u", result == 0 ? 1 : 0);
 262                 audit_log_end(audit_buf);
 263         }
 264 }
 265
 266 /**
 267  * netlbl_domhsh_validate - Validate a new domain mapping entry
 268  * @entry: the entry to validate
 269  *
 270  * This function validates the new domain mapping entry to ensure that it is
 271  * a valid entry.  Returns zero on success, negative values on failure.
 272  *
 273  */
 274 static int netlbl_domhsh_validate(const struct netlbl_dom_map *entry)
 275 {
 276         struct netlbl_af4list *iter4;
 277         struct netlbl_domaddr4_map *map4;
 278 #if IS_ENABLED(CONFIG_IPV6)
 279         struct netlbl_af6list *iter6;
 280         struct netlbl_domaddr6_map *map6;
 281 #endif /* IPv6 */
 282
 283         if (entry == NULL)
 284                 return -EINVAL;
 285
 286         if (entry->family != AF_INET && entry->family != AF_INET6 &&
 287             (entry->family != AF_UNSPEC ||
 288              entry->def.type != NETLBL_NLTYPE_UNLABELED))
 289                 return -EINVAL;
 290
 291         switch (entry->def.type) {
 292         case NETLBL_NLTYPE_UNLABELED:
 293                 if (entry->def.cipso != NULL || entry->def.calipso != NULL ||
 294                     entry->def.addrsel != NULL)
 295                         return -EINVAL;
 296                 break;
 297         case NETLBL_NLTYPE_CIPSOV4:
 298                 if (entry->family != AF_INET ||
 299                     entry->def.cipso == NULL)
 300                         return -EINVAL;
 301                 break;
 302         case NETLBL_NLTYPE_CALIPSO:
 303                 if (entry->family != AF_INET6 ||
 304                     entry->def.calipso == NULL)
 305                         return -EINVAL;
 306                 break;
 307         case NETLBL_NLTYPE_ADDRSELECT:
 308                 netlbl_af4list_foreach(iter4, &entry->def.addrsel->list4) {
 309                         map4 = netlbl_domhsh_addr4_entry(iter4);
 310                         switch (map4->def.type) {
 311                         case NETLBL_NLTYPE_UNLABELED:
 312                                 if (map4->def.cipso != NULL)
 313                                         return -EINVAL;
 314                                 break;
 315                         case NETLBL_NLTYPE_CIPSOV4:
 316                                 if (map4->def.cipso == NULL)
 317                                         return -EINVAL;
 318                                 break;
 319                         default:
 320                                 return -EINVAL;
 321                         }
 322                 }
 323 #if IS_ENABLED(CONFIG_IPV6)
 324                 netlbl_af6list_foreach(iter6, &entry->def.addrsel->list6) {
 325                         map6 = netlbl_domhsh_addr6_entry(iter6);
 326                         switch (map6->def.type) {
 327                         case NETLBL_NLTYPE_UNLABELED:
 328                                 if (map6->def.calipso != NULL)
 329                                         return -EINVAL;
 330                                 break;
 331                         case NETLBL_NLTYPE_CALIPSO:
 332                                 if (map6->def.calipso == NULL)
 333                                         return -EINVAL;
 334                                 break;
 335                         default:
 336                                 return -EINVAL;
 337                         }
 338                 }
 339 #endif /* IPv6 */
 340                 break;
 341         default:
 342                 return -EINVAL;
 343         }
 344
 345         return 0;
 346 }
 347
 348 /*
 349  * Domain Hash Table Functions
 350  */
 351
 352 /**
 353  * netlbl_domhsh_init - Init for the domain hash
 354  * @size: the number of bits to use for the hash buckets
 355  *
 356  * Description:
 357  * Initializes the domain hash table, should be called only by
 358  * netlbl_user_init() during initialization.  Returns zero on success, non-zero
 359  * values on error.
 360  *
 361  */
 362 int __init netlbl_domhsh_init(u32 size)
 363 {
 364         u32 iter;
 365         struct netlbl_domhsh_tbl *hsh_tbl;
 366
 367         if (size == 0)
 368                 return -EINVAL;
 369
 370         hsh_tbl = kmalloc(sizeof(*hsh_tbl), GFP_KERNEL);
 371         if (hsh_tbl == NULL)
 372                 return -ENOMEM;
 373         hsh_tbl->size = 1 << size;
 374         hsh_tbl->tbl = kcalloc(hsh_tbl->size,
 375                                sizeof(struct list_head),
 376                                GFP_KERNEL);
 377         if (hsh_tbl->tbl == NULL) {
 378                 kfree(hsh_tbl);
 379                 return -ENOMEM;
 380         }
 381         for (iter = 0; iter < hsh_tbl->size; iter++)
 382                 INIT_LIST_HEAD(&hsh_tbl->tbl[iter]);
 383
 384         spin_lock(&netlbl_domhsh_lock);
 385         rcu_assign_pointer(netlbl_domhsh, hsh_tbl);
 386         spin_unlock(&netlbl_domhsh_lock);
 387
 388         return 0;
 389 }
 390
 391 /**
 392  * netlbl_domhsh_add - Adds a entry to the domain hash table
 393  * @entry: the entry to add
 394  * @audit_info: NetLabel audit information
 395  *
 396  * Description:
 397  * Adds a new entry to the domain hash table and handles any updates to the
 398  * lower level protocol handler (i.e. CIPSO).  @entry->family may be set to
 399  * %AF_UNSPEC which will add an entry that matches all address families.  This
 400  * is only useful for the unlabelled type and will only succeed if there is no
 401  * existing entry for any address family with the same domain.  Returns zero
 402  * on success, negative on failure.
 403  *
 404  */
 405 int netlbl_domhsh_add(struct netlbl_dom_map *entry,
 406                       struct netlbl_audit *audit_info)
 407 {
 408         int ret_val = 0;
 409         struct netlbl_dom_map *entry_old, *entry_b;
 410         struct netlbl_af4list *iter4;
 411         struct netlbl_af4list *tmp4;
 412 #if IS_ENABLED(CONFIG_IPV6)
 413         struct netlbl_af6list *iter6;
 414         struct netlbl_af6list *tmp6;
 415 #endif /* IPv6 */
 416
 417         ret_val = netlbl_domhsh_validate(entry);
 418         if (ret_val != 0)
 419                 return ret_val;
 420
 421         /* XXX - we can remove this RCU read lock as the spinlock protects the
 422          *       entire function, but before we do we need to fixup the
 423          *       netlbl_af[4,6]list RCU functions to do "the right thing" with
 424          *       respect to rcu_dereference() when only a spinlock is held. */
 425         rcu_read_lock();
 426         spin_lock(&netlbl_domhsh_lock);
 427         if (entry->domain != NULL)
 428                 entry_old = netlbl_domhsh_search(entry->domain, entry->family);
 429         else
 430                 entry_old = netlbl_domhsh_search_def(entry->domain,
 431                                                      entry->family);
 432         if (entry_old == NULL) {
 433                 entry->valid = 1;
 434
 435                 if (entry->domain != NULL) {
 436                         u32 bkt = netlbl_domhsh_hash(entry->domain);
 437                         list_add_tail_rcu(&entry->list,
 438                                     &rcu_dereference(netlbl_domhsh)->tbl[bkt]);
 439                 } else {
 440                         INIT_LIST_HEAD(&entry->list);
 441                         switch (entry->family) {
 442                         case AF_INET:
 443                                 rcu_assign_pointer(netlbl_domhsh_def_ipv4,
 444                                                    entry);
 445                                 break;
 446                         case AF_INET6:
 447                                 rcu_assign_pointer(netlbl_domhsh_def_ipv6,
 448                                                    entry);
 449                                 break;
 450                         case AF_UNSPEC:
 451                                 if (entry->def.type !=
 452                                     NETLBL_NLTYPE_UNLABELED) {
 453                                         ret_val = -EINVAL;
 454                                         goto add_return;
 455                                 }
 456                                 entry_b = kzalloc(sizeof(*entry_b), GFP_ATOMIC);
 457                                 if (entry_b == NULL) {
 458                                         ret_val = -ENOMEM;
 459                                         goto add_return;
 460                                 }
 461                                 entry_b->family = AF_INET6;
 462                                 entry_b->def.type = NETLBL_NLTYPE_UNLABELED;
 463                                 entry_b->valid = 1;
 464                                 entry->family = AF_INET;
 465                                 rcu_assign_pointer(netlbl_domhsh_def_ipv4,
 466                                                    entry);
 467                                 rcu_assign_pointer(netlbl_domhsh_def_ipv6,
 468                                                    entry_b);
 469                                 break;
 470                         default:
 471                                 /* Already checked in
 472                                  * netlbl_domhsh_validate(). */
 473                                 ret_val = -EINVAL;
 474                                 goto add_return;
 475                         }
 476                 }
 477
 478                 if (entry->def.type == NETLBL_NLTYPE_ADDRSELECT) {
 479                         netlbl_af4list_foreach_rcu(iter4,
 480                                                    &entry->def.addrsel->list4)
 481                                 netlbl_domhsh_audit_add(entry, iter4, NULL,
 482                                                         ret_val, audit_info);
 483 #if IS_ENABLED(CONFIG_IPV6)
 484                         netlbl_af6list_foreach_rcu(iter6,
 485                                                    &entry->def.addrsel->list6)
 486                                 netlbl_domhsh_audit_add(entry, NULL, iter6,
 487                                                         ret_val, audit_info);
 488 #endif /* IPv6 */
 489                 } else
 490                         netlbl_domhsh_audit_add(entry, NULL, NULL,
 491                                                 ret_val, audit_info);
 492         } else if (entry_old->def.type == NETLBL_NLTYPE_ADDRSELECT &&
 493                    entry->def.type == NETLBL_NLTYPE_ADDRSELECT) {
 494                 struct list_head *old_list4;
 495                 struct list_head *old_list6;
 496
 497                 old_list4 = &entry_old->def.addrsel->list4;
 498                 old_list6 = &entry_old->def.addrsel->list6;
 499
 500                 /* we only allow the addition of address selectors if all of
 501                  * the selectors do not exist in the existing domain map */
 502                 netlbl_af4list_foreach_rcu(iter4, &entry->def.addrsel->list4)
 503                         if (netlbl_af4list_search_exact(iter4->addr,
 504                                                         iter4->mask,
 505                                                         old_list4)) {
 506                                 ret_val = -EEXIST;
 507                                 goto add_return;
 508                         }
 509 #if IS_ENABLED(CONFIG_IPV6)
 510                 netlbl_af6list_foreach_rcu(iter6, &entry->def.addrsel->list6)
 511                         if (netlbl_af6list_search_exact(&iter6->addr,
 512                                                         &iter6->mask,
 513                                                         old_list6)) {
 514                                 ret_val = -EEXIST;
 515                                 goto add_return;
 516                         }
 517 #endif /* IPv6 */
 518
 519                 netlbl_af4list_foreach_safe(iter4, tmp4,
 520                                             &entry->def.addrsel->list4) {
 521                         netlbl_af4list_remove_entry(iter4);
 522                         iter4->valid = 1;
 523                         ret_val = netlbl_af4list_add(iter4, old_list4);
 524                         netlbl_domhsh_audit_add(entry_old, iter4, NULL,
 525                                                 ret_val, audit_info);
 526                         if (ret_val != 0)
 527                                 goto add_return;
 528                 }
 529 #if IS_ENABLED(CONFIG_IPV6)
 530                 netlbl_af6list_foreach_safe(iter6, tmp6,
 531                                             &entry->def.addrsel->list6) {
 532                         netlbl_af6list_remove_entry(iter6);
 533                         iter6->valid = 1;
 534                         ret_val = netlbl_af6list_add(iter6, old_list6);
 535                         netlbl_domhsh_audit_add(entry_old, NULL, iter6,
 536                                                 ret_val, audit_info);
 537                         if (ret_val != 0)
 538                                 goto add_return;
 539                 }
 540 #endif /* IPv6 */
 541                 /* cleanup the new entry since we've moved everything over */
 542                 netlbl_domhsh_free_entry(&entry->rcu);
 543         } else
 544                 ret_val = -EINVAL;
 545
 546 add_return:
 547         spin_unlock(&netlbl_domhsh_lock);
 548         rcu_read_unlock();
 549         return ret_val;
 550 }
 551
 552 /**
 553  * netlbl_domhsh_add_default - Adds the default entry to the domain hash table
 554  * @entry: the entry to add
 555  * @audit_info: NetLabel audit information
 556  *
 557  * Description:
 558  * Adds a new default entry to the domain hash table and handles any updates
 559  * to the lower level protocol handler (i.e. CIPSO).  Returns zero on success,
 560  * negative on failure.
 561  *
 562  */
 563 int netlbl_domhsh_add_default(struct netlbl_dom_map *entry,
 564                               struct netlbl_audit *audit_info)
 565 {
 566         return netlbl_domhsh_add(entry, audit_info);
 567 }
 568
 569 /**
 570  * netlbl_domhsh_remove_entry - Removes a given entry from the domain table
 571  * @entry: the entry to remove
 572  * @audit_info: NetLabel audit information
 573  *
 574  * Description:
 575  * Removes an entry from the domain hash table and handles any updates to the
 576  * lower level protocol handler (i.e. CIPSO).  Caller is responsible for
 577  * ensuring that the RCU read lock is held.  Returns zero on success, negative
 578  * on failure.
 579  *
 580  */
 581 int netlbl_domhsh_remove_entry(struct netlbl_dom_map *entry,
 582                                struct netlbl_audit *audit_info)
 583 {
 584         int ret_val = 0;
 585         struct audit_buffer *audit_buf;
 586         struct netlbl_af4list *iter4;
 587         struct netlbl_domaddr4_map *map4;
 588 #if IS_ENABLED(CONFIG_IPV6)
 589         struct netlbl_af6list *iter6;
 590         struct netlbl_domaddr6_map *map6;
 591 #endif /* IPv6 */
 592
 593         if (entry == NULL)
 594                 return -ENOENT;
 595
 596         spin_lock(&netlbl_domhsh_lock);
 597         if (entry->valid) {
 598                 entry->valid = 0;
 599                 if (entry == rcu_dereference(netlbl_domhsh_def_ipv4))
 600                         RCU_INIT_POINTER(netlbl_domhsh_def_ipv4, NULL);
 601                 else if (entry == rcu_dereference(netlbl_domhsh_def_ipv6))
 602                         RCU_INIT_POINTER(netlbl_domhsh_def_ipv6, NULL);
 603                 else
 604                         list_del_rcu(&entry->list);
 605         } else
 606                 ret_val = -ENOENT;
 607         spin_unlock(&netlbl_domhsh_lock);
 608
 609         if (ret_val)
 610                 return ret_val;
 611
 612         audit_buf = netlbl_audit_start_common(AUDIT_MAC_MAP_DEL, audit_info);
 613         if (audit_buf != NULL) {
 614                 audit_log_format(audit_buf,
 615                                  " nlbl_domain=%s res=1",
 616                                  entry->domain ? entry->domain : "(default)");
 617                 audit_log_end(audit_buf);
 618         }
 619
 620         switch (entry->def.type) {
 621         case NETLBL_NLTYPE_ADDRSELECT:
 622                 netlbl_af4list_foreach_rcu(iter4, &entry->def.addrsel->list4) {
 623                         map4 = netlbl_domhsh_addr4_entry(iter4);
 624                         cipso_v4_doi_putdef(map4->def.cipso);
 625                 }
 626 #if IS_ENABLED(CONFIG_IPV6)
 627                 netlbl_af6list_foreach_rcu(iter6, &entry->def.addrsel->list6) {
 628                         map6 = netlbl_domhsh_addr6_entry(iter6);
 629                         calipso_doi_putdef(map6->def.calipso);
 630                 }
 631 #endif /* IPv6 */
 632                 break;
 633         case NETLBL_NLTYPE_CIPSOV4:
 634                 cipso_v4_doi_putdef(entry->def.cipso);
 635                 break;
 636 #if IS_ENABLED(CONFIG_IPV6)
 637         case NETLBL_NLTYPE_CALIPSO:
 638                 calipso_doi_putdef(entry->def.calipso);
 639                 break;
 640 #endif /* IPv6 */
 641         }
 642         call_rcu(&entry->rcu, netlbl_domhsh_free_entry);
 643
 644         return ret_val;
 645 }
 646
 647 /**
 648  * netlbl_domhsh_remove_af4 - Removes an address selector entry
 649  * @domain: the domain
 650  * @addr: IPv4 address
 651  * @mask: IPv4 address mask
 652  * @audit_info: NetLabel audit information
 653  *
 654  * Description:
 655  * Removes an individual address selector from a domain mapping and potentially
 656  * the entire mapping if it is empty.  Returns zero on success, negative values
 657  * on failure.
 658  *
 659  */
 660 int netlbl_domhsh_remove_af4(const char *domain,
 661                              const struct in_addr *addr,
 662                              const struct in_addr *mask,
 663                              struct netlbl_audit *audit_info)
 664 {
 665         struct netlbl_dom_map *entry_map;
 666         struct netlbl_af4list *entry_addr;
 667         struct netlbl_af4list *iter4;
 668 #if IS_ENABLED(CONFIG_IPV6)
 669         struct netlbl_af6list *iter6;
 670 #endif /* IPv6 */
 671         struct netlbl_domaddr4_map *entry;
 672
 673         rcu_read_lock();
 674
 675         if (domain)
 676                 entry_map = netlbl_domhsh_search(domain, AF_INET);
 677         else
 678                 entry_map = netlbl_domhsh_search_def(domain, AF_INET);
 679         if (entry_map == NULL ||
 680             entry_map->def.type != NETLBL_NLTYPE_ADDRSELECT)
 681                 goto remove_af4_failure;
 682
 683         spin_lock(&netlbl_domhsh_lock);
 684         entry_addr = netlbl_af4list_remove(addr->s_addr, mask->s_addr,
 685                                            &entry_map->def.addrsel->list4);
 686         spin_unlock(&netlbl_domhsh_lock);
 687
 688         if (entry_addr == NULL)
 689                 goto remove_af4_failure;
 690         netlbl_af4list_foreach_rcu(iter4, &entry_map->def.addrsel->list4)
 691                 goto remove_af4_single_addr;
 692 #if IS_ENABLED(CONFIG_IPV6)
 693         netlbl_af6list_foreach_rcu(iter6, &entry_map->def.addrsel->list6)
 694                 goto remove_af4_single_addr;
 695 #endif /* IPv6 */
 696         /* the domain mapping is empty so remove it from the mapping table */
 697         netlbl_domhsh_remove_entry(entry_map, audit_info);
 698
 699 remove_af4_single_addr:
 700         rcu_read_unlock();
 701         /* yick, we can't use call_rcu here because we don't have a rcu head
 702          * pointer but hopefully this should be a rare case so the pause
 703          * shouldn't be a problem */
 704         synchronize_rcu();
 705         entry = netlbl_domhsh_addr4_entry(entry_addr);
 706         cipso_v4_doi_putdef(entry->def.cipso);
 707         kfree(entry);
 708         return 0;
 709
 710 remove_af4_failure:
 711         rcu_read_unlock();
 712         return -ENOENT;
 713 }
 714
 715 #if IS_ENABLED(CONFIG_IPV6)
 716 /**
 717  * netlbl_domhsh_remove_af6 - Removes an address selector entry
 718  * @domain: the domain
 719  * @addr: IPv6 address
 720  * @mask: IPv6 address mask
 721  * @audit_info: NetLabel audit information
 722  *
 723  * Description:
 724  * Removes an individual address selector from a domain mapping and potentially
 725  * the entire mapping if it is empty.  Returns zero on success, negative values
 726  * on failure.
 727  *
 728  */
 729 int netlbl_domhsh_remove_af6(const char *domain,
 730                              const struct in6_addr *addr,
 731                              const struct in6_addr *mask,
 732                              struct netlbl_audit *audit_info)
 733 {
 734         struct netlbl_dom_map *entry_map;
 735         struct netlbl_af6list *entry_addr;
 736         struct netlbl_af4list *iter4;
 737         struct netlbl_af6list *iter6;
 738         struct netlbl_domaddr6_map *entry;
 739
 740         rcu_read_lock();
 741
 742         if (domain)
 743                 entry_map = netlbl_domhsh_search(domain, AF_INET6);
 744         else
 745                 entry_map = netlbl_domhsh_search_def(domain, AF_INET6);
 746         if (entry_map == NULL ||
 747             entry_map->def.type != NETLBL_NLTYPE_ADDRSELECT)
 748                 goto remove_af6_failure;
 749
 750         spin_lock(&netlbl_domhsh_lock);
 751         entry_addr = netlbl_af6list_remove(addr, mask,
 752                                            &entry_map->def.addrsel->list6);
 753         spin_unlock(&netlbl_domhsh_lock);
 754
 755         if (entry_addr == NULL)
 756                 goto remove_af6_failure;
 757         netlbl_af4list_foreach_rcu(iter4, &entry_map->def.addrsel->list4)
 758                 goto remove_af6_single_addr;
 759         netlbl_af6list_foreach_rcu(iter6, &entry_map->def.addrsel->list6)
 760                 goto remove_af6_single_addr;
 761         /* the domain mapping is empty so remove it from the mapping table */
 762         netlbl_domhsh_remove_entry(entry_map, audit_info);
 763
 764 remove_af6_single_addr:
 765         rcu_read_unlock();
 766         /* yick, we can't use call_rcu here because we don't have a rcu head
 767          * pointer but hopefully this should be a rare case so the pause
 768          * shouldn't be a problem */
 769         synchronize_rcu();
 770         entry = netlbl_domhsh_addr6_entry(entry_addr);
 771         calipso_doi_putdef(entry->def.calipso);
 772         kfree(entry);
 773         return 0;
 774
 775 remove_af6_failure:
 776         rcu_read_unlock();
 777         return -ENOENT;
 778 }
 779 #endif /* IPv6 */
 780
 781 /**
 782  * netlbl_domhsh_remove - Removes an entry from the domain hash table
 783  * @domain: the domain to remove
 784  * @family: address family
 785  * @audit_info: NetLabel audit information
 786  *
 787  * Description:
 788  * Removes an entry from the domain hash table and handles any updates to the
 789  * lower level protocol handler (i.e. CIPSO).  @family may be %AF_UNSPEC which
 790  * removes all address family entries.  Returns zero on success, negative on
 791  * failure.
 792  *
 793  */
 794 int netlbl_domhsh_remove(const char *domain, u16 family,
 795                          struct netlbl_audit *audit_info)
 796 {
 797         int ret_val = -EINVAL;
 798         struct netlbl_dom_map *entry;
 799
 800         rcu_read_lock();
 801
 802         if (family == AF_INET || family == AF_UNSPEC) {
 803                 if (domain)
 804                         entry = netlbl_domhsh_search(domain, AF_INET);
 805                 else
 806                         entry = netlbl_domhsh_search_def(domain, AF_INET);
 807                 ret_val = netlbl_domhsh_remove_entry(entry, audit_info);
 808                 if (ret_val && ret_val != -ENOENT)
 809                         goto done;
 810         }
 811         if (family == AF_INET6 || family == AF_UNSPEC) {
 812                 int ret_val2;
 813
 814                 if (domain)
 815                         entry = netlbl_domhsh_search(domain, AF_INET6);
 816                 else
 817                         entry = netlbl_domhsh_search_def(domain, AF_INET6);
 818                 ret_val2 = netlbl_domhsh_remove_entry(entry, audit_info);
 819                 if (ret_val2 != -ENOENT)
 820                         ret_val = ret_val2;
 821         }
 822 done:
 823         rcu_read_unlock();
 824
 825         return ret_val;
 826 }
 827
 828 /**
 829  * netlbl_domhsh_remove_default - Removes the default entry from the table
 830  * @family: address family
 831  * @audit_info: NetLabel audit information
 832  *
 833  * Description:
 834  * Removes/resets the default entry corresponding to @family from the domain
 835  * hash table and handles any updates to the lower level protocol handler
 836  * (i.e. CIPSO).  @family may be %AF_UNSPEC which removes all address family
 837  * entries.  Returns zero on success, negative on failure.
 838  *
 839  */
 840 int netlbl_domhsh_remove_default(u16 family, struct netlbl_audit *audit_info)
 841 {
 842         return netlbl_domhsh_remove(NULL, family, audit_info);
 843 }
 844
 845 /**
 846  * netlbl_domhsh_getentry - Get an entry from the domain hash table
 847  * @domain: the domain name to search for
 848  * @family: address family
 849  *
 850  * Description:
 851  * Look through the domain hash table searching for an entry to match @domain,
 852  * with address family @family, return a pointer to a copy of the entry or
 853  * NULL.  The caller is responsible for ensuring that rcu_read_[un]lock() is
 854  * called.
 855  *
 856  */
 857 struct netlbl_dom_map *netlbl_domhsh_getentry(const char *domain, u16 family)
 858 {
 859         if (family == AF_UNSPEC)
 860                 return NULL;
 861         return netlbl_domhsh_search_def(domain, family);
 862 }
 863
 864 /**
 865  * netlbl_domhsh_getentry_af4 - Get an entry from the domain hash table
 866  * @domain: the domain name to search for
 867  * @addr: the IP address to search for
 868  *
 869  * Description:
 870  * Look through the domain hash table searching for an entry to match @domain
 871  * and @addr, return a pointer to a copy of the entry or NULL.  The caller is
 872  * responsible for ensuring that rcu_read_[un]lock() is called.
 873  *
 874  */
 875 struct netlbl_dommap_def *netlbl_domhsh_getentry_af4(const char *domain,
 876                                                      __be32 addr)
 877 {
 878         struct netlbl_dom_map *dom_iter;
 879         struct netlbl_af4list *addr_iter;
 880
 881         dom_iter = netlbl_domhsh_search_def(domain, AF_INET);
 882         if (dom_iter == NULL)
 883                 return NULL;
 884
 885         if (dom_iter->def.type != NETLBL_NLTYPE_ADDRSELECT)
 886                 return &dom_iter->def;
 887         addr_iter = netlbl_af4list_search(addr, &dom_iter->def.addrsel->list4);
 888         if (addr_iter == NULL)
 889                 return NULL;
 890         return &(netlbl_domhsh_addr4_entry(addr_iter)->def);
 891 }
 892
 893 #if IS_ENABLED(CONFIG_IPV6)
 894 /**
 895  * netlbl_domhsh_getentry_af6 - Get an entry from the domain hash table
 896  * @domain: the domain name to search for
 897  * @addr: the IP address to search for
 898  *
 899  * Description:
 900  * Look through the domain hash table searching for an entry to match @domain
 901  * and @addr, return a pointer to a copy of the entry or NULL.  The caller is
 902  * responsible for ensuring that rcu_read_[un]lock() is called.
 903  *
 904  */
 905 struct netlbl_dommap_def *netlbl_domhsh_getentry_af6(const char *domain,
 906                                                    const struct in6_addr *addr)
 907 {
 908         struct netlbl_dom_map *dom_iter;
 909         struct netlbl_af6list *addr_iter;
 910
 911         dom_iter = netlbl_domhsh_search_def(domain, AF_INET6);
 912         if (dom_iter == NULL)
 913                 return NULL;
 914
 915         if (dom_iter->def.type != NETLBL_NLTYPE_ADDRSELECT)
 916                 return &dom_iter->def;
 917         addr_iter = netlbl_af6list_search(addr, &dom_iter->def.addrsel->list6);
 918         if (addr_iter == NULL)
 919                 return NULL;
 920         return &(netlbl_domhsh_addr6_entry(addr_iter)->def);
 921 }
 922 #endif /* IPv6 */
 923
 924 /**
 925  * netlbl_domhsh_walk - Iterate through the domain mapping hash table
 926  * @skip_bkt: the number of buckets to skip at the start
 927  * @skip_chain: the number of entries to skip in the first iterated bucket
 928  * @callback: callback for each entry
 929  * @cb_arg: argument for the callback function
 930  *
 931  * Description:
 932  * Interate over the domain mapping hash table, skipping the first @skip_bkt
 933  * buckets and @skip_chain entries.  For each entry in the table call
 934  * @callback, if @callback returns a negative value stop 'walking' through the
 935  * table and return.  Updates the values in @skip_bkt and @skip_chain on
 936  * return.  Returns zero on success, negative values on failure.
 937  *
 938  */
 939 int netlbl_domhsh_walk(u32 *skip_bkt,
 940                      u32 *skip_chain,
 941                      int (*callback) (struct netlbl_dom_map *entry, void *arg),
 942                      void *cb_arg)
 943 {
 944         int ret_val = -ENOENT;
 945         u32 iter_bkt;
 946         struct list_head *iter_list;
 947         struct netlbl_dom_map *iter_entry;
 948         u32 chain_cnt = 0;
 949
 950         rcu_read_lock();
 951         for (iter_bkt = *skip_bkt;
 952              iter_bkt < rcu_dereference(netlbl_domhsh)->size;
 953              iter_bkt++, chain_cnt = 0) {
 954                 iter_list = &rcu_dereference(netlbl_domhsh)->tbl[iter_bkt];
 955                 list_for_each_entry_rcu(iter_entry, iter_list, list)
 956                         if (iter_entry->valid) {
 957                                 if (chain_cnt++ < *skip_chain)
 958                                         continue;
 959                                 ret_val = callback(iter_entry, cb_arg);
 960                                 if (ret_val < 0) {
 961                                         chain_cnt--;
 962                                         goto walk_return;
 963                                 }
 964                         }
 965         }
 966
 967 walk_return:
 968         rcu_read_unlock();
 969         *skip_bkt = iter_bkt;
 970         *skip_chain = chain_cnt;
 971         return ret_val;
 972 }