net/netlabel/netlabel_kapi.c

   1 /*
   2  * NetLabel Kernel API
   3  *
   4  * This file defines the kernel API for the NetLabel system.  The NetLabel
   5  * system manages static and dynamic label mappings for network protocols such
   6  * as CIPSO and RIPSO.
   7  *
   8  * Author: Paul Moore <paul@paul-moore.com>
   9  *
  10  */
  11
  12 /*
  13  * (c) Copyright Hewlett-Packard Development Company, L.P., 2006, 2008
  14  *
  15  * This program is free software;  you can redistribute it and/or modify
  16  * it under the terms of the GNU General Public License as published by
  17  * the Free Software Foundation; either version 2 of the License, or
  18  * (at your option) any later version.
  19  *
  20  * This program is distributed in the hope that it will be useful,
  21  * but WITHOUT ANY WARRANTY;  without even the implied warranty of
  22  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See
  23  * the GNU General Public License for more details.
  24  *
  25  * You should have received a copy of the GNU General Public License
  26  * along with this program;  if not, see <http://www.gnu.org/licenses/>.
  27  *
  28  */
  29
  30 #include <linux/init.h>
  31 #include <linux/types.h>
  32 #include <linux/slab.h>
  33 #include <linux/audit.h>
  34 #include <linux/in.h>
  35 #include <linux/in6.h>
  36 #include <net/ip.h>
  37 #include <net/ipv6.h>
  38 #include <net/netlabel.h>
  39 #include <net/cipso_ipv4.h>
  40 #include <asm/bug.h>
  41 #include <linux/atomic.h>
  42
  43 #include "netlabel_domainhash.h"
  44 #include "netlabel_unlabeled.h"
  45 #include "netlabel_cipso_v4.h"
  46 #include "netlabel_user.h"
  47 #include "netlabel_mgmt.h"
  48 #include "netlabel_addrlist.h"
  49
  50 /*
  51  * Configuration Functions
  52  */
  53
  54 /**
  55  * netlbl_cfg_map_del - Remove a NetLabel/LSM domain mapping
  56  * @domain: the domain mapping to remove
  57  * @family: address family
  58  * @addr: IP address
  59  * @mask: IP address mask
  60  * @audit_info: NetLabel audit information
  61  *
  62  * Description:
  63  * Removes a NetLabel/LSM domain mapping.  A @domain value of NULL causes the
  64  * default domain mapping to be removed.  Returns zero on success, negative
  65  * values on failure.
  66  *
  67  */
  68 int netlbl_cfg_map_del(const char *domain,
  69                        u16 family,
  70                        const void *addr,
  71                        const void *mask,
  72                        struct netlbl_audit *audit_info)
  73 {
  74         if (addr == NULL && mask == NULL) {
  75                 return netlbl_domhsh_remove(domain, audit_info);
  76         } else if (addr != NULL && mask != NULL) {
  77                 switch (family) {
  78                 case AF_INET:
  79                         return netlbl_domhsh_remove_af4(domain, addr, mask,
  80                                                         audit_info);
  81                 default:
  82                         return -EPFNOSUPPORT;
  83                 }
  84         } else
  85                 return -EINVAL;
  86 }
  87
  88 /**
  89  * netlbl_cfg_unlbl_map_add - Add a new unlabeled mapping
  90  * @domain: the domain mapping to add
  91  * @family: address family
  92  * @addr: IP address
  93  * @mask: IP address mask
  94  * @audit_info: NetLabel audit information
  95  *
  96  * Description:
  97  * Adds a new unlabeled NetLabel/LSM domain mapping.  A @domain value of NULL
  98  * causes a new default domain mapping to be added.  Returns zero on success,
  99  * negative values on failure.
 100  *
 101  */
 102 int netlbl_cfg_unlbl_map_add(const char *domain,
 103                              u16 family,
 104                              const void *addr,
 105                              const void *mask,
 106                              struct netlbl_audit *audit_info)
 107 {
 108         int ret_val = -ENOMEM;
 109         struct netlbl_dom_map *entry;
 110         struct netlbl_domaddr_map *addrmap = NULL;
 111         struct netlbl_domaddr4_map *map4 = NULL;
 112         struct netlbl_domaddr6_map *map6 = NULL;
 113
 114         entry = kzalloc(sizeof(*entry), GFP_ATOMIC);
 115         if (entry == NULL)
 116                 return -ENOMEM;
 117         if (domain != NULL) {
 118                 entry->domain = kstrdup(domain, GFP_ATOMIC);
 119                 if (entry->domain == NULL)
 120                         goto cfg_unlbl_map_add_failure;
 121         }
 122
 123         if (addr == NULL && mask == NULL)
 124                 entry->def.type = NETLBL_NLTYPE_UNLABELED;
 125         else if (addr != NULL && mask != NULL) {
 126                 addrmap = kzalloc(sizeof(*addrmap), GFP_ATOMIC);
 127                 if (addrmap == NULL)
 128                         goto cfg_unlbl_map_add_failure;
 129                 INIT_LIST_HEAD(&addrmap->list4);
 130                 INIT_LIST_HEAD(&addrmap->list6);
 131
 132                 switch (family) {
 133                 case AF_INET: {
 134                         const struct in_addr *addr4 = addr;
 135                         const struct in_addr *mask4 = mask;
 136                         map4 = kzalloc(sizeof(*map4), GFP_ATOMIC);
 137                         if (map4 == NULL)
 138                                 goto cfg_unlbl_map_add_failure;
 139                         map4->def.type = NETLBL_NLTYPE_UNLABELED;
 140                         map4->list.addr = addr4->s_addr & mask4->s_addr;
 141                         map4->list.mask = mask4->s_addr;
 142                         map4->list.valid = 1;
 143                         ret_val = netlbl_af4list_add(&map4->list,
 144                                                      &addrmap->list4);
 145                         if (ret_val != 0)
 146                                 goto cfg_unlbl_map_add_failure;
 147                         break;
 148                         }
 149 #if IS_ENABLED(CONFIG_IPV6)
 150                 case AF_INET6: {
 151                         const struct in6_addr *addr6 = addr;
 152                         const struct in6_addr *mask6 = mask;
 153                         map6 = kzalloc(sizeof(*map6), GFP_ATOMIC);
 154                         if (map6 == NULL)
 155                                 goto cfg_unlbl_map_add_failure;
 156                         map6->def.type = NETLBL_NLTYPE_UNLABELED;
 157                         map6->list.addr = *addr6;
 158                         map6->list.addr.s6_addr32[0] &= mask6->s6_addr32[0];
 159                         map6->list.addr.s6_addr32[1] &= mask6->s6_addr32[1];
 160                         map6->list.addr.s6_addr32[2] &= mask6->s6_addr32[2];
 161                         map6->list.addr.s6_addr32[3] &= mask6->s6_addr32[3];
 162                         map6->list.mask = *mask6;
 163                         map6->list.valid = 1;
 164                         ret_val = netlbl_af6list_add(&map6->list,
 165                                                      &addrmap->list6);
 166                         if (ret_val != 0)
 167                                 goto cfg_unlbl_map_add_failure;
 168                         break;
 169                         }
 170 #endif /* IPv6 */
 171                 default:
 172                         goto cfg_unlbl_map_add_failure;
 173                         break;
 174                 }
 175
 176                 entry->def.addrsel = addrmap;
 177                 entry->def.type = NETLBL_NLTYPE_ADDRSELECT;
 178         } else {
 179                 ret_val = -EINVAL;
 180                 goto cfg_unlbl_map_add_failure;
 181         }
 182
 183         ret_val = netlbl_domhsh_add(entry, audit_info);
 184         if (ret_val != 0)
 185                 goto cfg_unlbl_map_add_failure;
 186
 187         return 0;
 188
 189 cfg_unlbl_map_add_failure:
 190         kfree(entry->domain);
 191         kfree(entry);
 192         kfree(addrmap);
 193         kfree(map4);
 194         kfree(map6);
 195         return ret_val;
 196 }
 197
 198
 199 /**
 200  * netlbl_cfg_unlbl_static_add - Adds a new static label
 201  * @net: network namespace
 202  * @dev_name: interface name
 203  * @addr: IP address in network byte order (struct in[6]_addr)
 204  * @mask: address mask in network byte order (struct in[6]_addr)
 205  * @family: address family
 206  * @secid: LSM secid value for the entry
 207  * @audit_info: NetLabel audit information
 208  *
 209  * Description:
 210  * Adds a new NetLabel static label to be used when protocol provided labels
 211  * are not present on incoming traffic.  If @dev_name is NULL then the default
 212  * interface will be used.  Returns zero on success, negative values on failure.
 213  *
 214  */
 215 int netlbl_cfg_unlbl_static_add(struct net *net,
 216                                 const char *dev_name,
 217                                 const void *addr,
 218                                 const void *mask,
 219                                 u16 family,
 220                                 u32 secid,
 221                                 struct netlbl_audit *audit_info)
 222 {
 223         u32 addr_len;
 224
 225         switch (family) {
 226         case AF_INET:
 227                 addr_len = sizeof(struct in_addr);
 228                 break;
 229 #if IS_ENABLED(CONFIG_IPV6)
 230         case AF_INET6:
 231                 addr_len = sizeof(struct in6_addr);
 232                 break;
 233 #endif /* IPv6 */
 234         default:
 235                 return -EPFNOSUPPORT;
 236         }
 237
 238         return netlbl_unlhsh_add(net,
 239                                  dev_name, addr, mask, addr_len,
 240                                  secid, audit_info);
 241 }
 242
 243 /**
 244  * netlbl_cfg_unlbl_static_del - Removes an existing static label
 245  * @net: network namespace
 246  * @dev_name: interface name
 247  * @addr: IP address in network byte order (struct in[6]_addr)
 248  * @mask: address mask in network byte order (struct in[6]_addr)
 249  * @family: address family
 250  * @secid: LSM secid value for the entry
 251  * @audit_info: NetLabel audit information
 252  *
 253  * Description:
 254  * Removes an existing NetLabel static label used when protocol provided labels
 255  * are not present on incoming traffic.  If @dev_name is NULL then the default
 256  * interface will be used.  Returns zero on success, negative values on failure.
 257  *
 258  */
 259 int netlbl_cfg_unlbl_static_del(struct net *net,
 260                                 const char *dev_name,
 261                                 const void *addr,
 262                                 const void *mask,
 263                                 u16 family,
 264                                 struct netlbl_audit *audit_info)
 265 {
 266         u32 addr_len;
 267
 268         switch (family) {
 269         case AF_INET:
 270                 addr_len = sizeof(struct in_addr);
 271                 break;
 272 #if IS_ENABLED(CONFIG_IPV6)
 273         case AF_INET6:
 274                 addr_len = sizeof(struct in6_addr);
 275                 break;
 276 #endif /* IPv6 */
 277         default:
 278                 return -EPFNOSUPPORT;
 279         }
 280
 281         return netlbl_unlhsh_remove(net,
 282                                     dev_name, addr, mask, addr_len,
 283                                     audit_info);
 284 }
 285
 286 /**
 287  * netlbl_cfg_cipsov4_add - Add a new CIPSOv4 DOI definition
 288  * @doi_def: CIPSO DOI definition
 289  * @audit_info: NetLabel audit information
 290  *
 291  * Description:
 292  * Add a new CIPSO DOI definition as defined by @doi_def.  Returns zero on
 293  * success and negative values on failure.
 294  *
 295  */
 296 int netlbl_cfg_cipsov4_add(struct cipso_v4_doi *doi_def,
 297                            struct netlbl_audit *audit_info)
 298 {
 299         return cipso_v4_doi_add(doi_def, audit_info);
 300 }
 301
 302 /**
 303  * netlbl_cfg_cipsov4_del - Remove an existing CIPSOv4 DOI definition
 304  * @doi: CIPSO DOI
 305  * @audit_info: NetLabel audit information
 306  *
 307  * Description:
 308  * Remove an existing CIPSO DOI definition matching @doi.  Returns zero on
 309  * success and negative values on failure.
 310  *
 311  */
 312 void netlbl_cfg_cipsov4_del(u32 doi, struct netlbl_audit *audit_info)
 313 {
 314         cipso_v4_doi_remove(doi, audit_info);
 315 }
 316
 317 /**
 318  * netlbl_cfg_cipsov4_map_add - Add a new CIPSOv4 DOI mapping
 319  * @doi: the CIPSO DOI
 320  * @domain: the domain mapping to add
 321  * @addr: IP address
 322  * @mask: IP address mask
 323  * @audit_info: NetLabel audit information
 324  *
 325  * Description:
 326  * Add a new NetLabel/LSM domain mapping for the given CIPSO DOI to the NetLabel
 327  * subsystem.  A @domain value of NULL adds a new default domain mapping.
 328  * Returns zero on success, negative values on failure.
 329  *
 330  */
 331 int netlbl_cfg_cipsov4_map_add(u32 doi,
 332                                const char *domain,
 333                                const struct in_addr *addr,
 334                                const struct in_addr *mask,
 335                                struct netlbl_audit *audit_info)
 336 {
 337         int ret_val = -ENOMEM;
 338         struct cipso_v4_doi *doi_def;
 339         struct netlbl_dom_map *entry;
 340         struct netlbl_domaddr_map *addrmap = NULL;
 341         struct netlbl_domaddr4_map *addrinfo = NULL;
 342
 343         doi_def = cipso_v4_doi_getdef(doi);
 344         if (doi_def == NULL)
 345                 return -ENOENT;
 346
 347         entry = kzalloc(sizeof(*entry), GFP_ATOMIC);
 348         if (entry == NULL)
 349                 goto out_entry;
 350         if (domain != NULL) {
 351                 entry->domain = kstrdup(domain, GFP_ATOMIC);
 352                 if (entry->domain == NULL)
 353                         goto out_domain;
 354         }
 355
 356         if (addr == NULL && mask == NULL) {
 357                 entry->def.cipso = doi_def;
 358                 entry->def.type = NETLBL_NLTYPE_CIPSOV4;
 359         } else if (addr != NULL && mask != NULL) {
 360                 addrmap = kzalloc(sizeof(*addrmap), GFP_ATOMIC);
 361                 if (addrmap == NULL)
 362                         goto out_addrmap;
 363                 INIT_LIST_HEAD(&addrmap->list4);
 364                 INIT_LIST_HEAD(&addrmap->list6);
 365
 366                 addrinfo = kzalloc(sizeof(*addrinfo), GFP_ATOMIC);
 367                 if (addrinfo == NULL)
 368                         goto out_addrinfo;
 369                 addrinfo->def.cipso = doi_def;
 370                 addrinfo->def.type = NETLBL_NLTYPE_CIPSOV4;
 371                 addrinfo->list.addr = addr->s_addr & mask->s_addr;
 372                 addrinfo->list.mask = mask->s_addr;
 373                 addrinfo->list.valid = 1;
 374                 ret_val = netlbl_af4list_add(&addrinfo->list, &addrmap->list4);
 375                 if (ret_val != 0)
 376                         goto cfg_cipsov4_map_add_failure;
 377
 378                 entry->def.addrsel = addrmap;
 379                 entry->def.type = NETLBL_NLTYPE_ADDRSELECT;
 380         } else {
 381                 ret_val = -EINVAL;
 382                 goto out_addrmap;
 383         }
 384
 385         ret_val = netlbl_domhsh_add(entry, audit_info);
 386         if (ret_val != 0)
 387                 goto cfg_cipsov4_map_add_failure;
 388
 389         return 0;
 390
 391 cfg_cipsov4_map_add_failure:
 392         kfree(addrinfo);
 393 out_addrinfo:
 394         kfree(addrmap);
 395 out_addrmap:
 396         kfree(entry->domain);
 397 out_domain:
 398         kfree(entry);
 399 out_entry:
 400         cipso_v4_doi_putdef(doi_def);
 401         return ret_val;
 402 }
 403
 404 /*
 405  * Security Attribute Functions
 406  */
 407
 408 /**
 409  * netlbl_secattr_catmap_walk - Walk a LSM secattr catmap looking for a bit
 410  * @catmap: the category bitmap
 411  * @offset: the offset to start searching at, in bits
 412  *
 413  * Description:
 414  * This function walks a LSM secattr category bitmap starting at @offset and
 415  * returns the spot of the first set bit or -ENOENT if no bits are set.
 416  *
 417  */
 418 int netlbl_secattr_catmap_walk(struct netlbl_lsm_secattr_catmap *catmap,
 419                                u32 offset)
 420 {
 421         struct netlbl_lsm_secattr_catmap *iter = catmap;
 422         u32 node_idx;
 423         u32 node_bit;
 424         NETLBL_CATMAP_MAPTYPE bitmap;
 425
 426         if (offset > iter->startbit) {
 427                 while (offset >= (iter->startbit + NETLBL_CATMAP_SIZE)) {
 428                         iter = iter->next;
 429                         if (iter == NULL)
 430                                 return -ENOENT;
 431                 }
 432                 node_idx = (offset - iter->startbit) / NETLBL_CATMAP_MAPSIZE;
 433                 node_bit = offset - iter->startbit -
 434                            (NETLBL_CATMAP_MAPSIZE * node_idx);
 435         } else {
 436                 node_idx = 0;
 437                 node_bit = 0;
 438         }
 439         bitmap = iter->bitmap[node_idx] >> node_bit;
 440
 441         for (;;) {
 442                 if (bitmap != 0) {
 443                         while ((bitmap & NETLBL_CATMAP_BIT) == 0) {
 444                                 bitmap >>= 1;
 445                                 node_bit++;
 446                         }
 447                         return iter->startbit +
 448                                 (NETLBL_CATMAP_MAPSIZE * node_idx) + node_bit;
 449                 }
 450                 if (++node_idx >= NETLBL_CATMAP_MAPCNT) {
 451                         if (iter->next != NULL) {
 452                                 iter = iter->next;
 453                                 node_idx = 0;
 454                         } else
 455                                 return -ENOENT;
 456                 }
 457                 bitmap = iter->bitmap[node_idx];
 458                 node_bit = 0;
 459         }
 460
 461         return -ENOENT;
 462 }
 463
 464 /**
 465  * netlbl_secattr_catmap_walk_rng - Find the end of a string of set bits
 466  * @catmap: the category bitmap
 467  * @offset: the offset to start searching at, in bits
 468  *
 469  * Description:
 470  * This function walks a LSM secattr category bitmap starting at @offset and
 471  * returns the spot of the first cleared bit or -ENOENT if the offset is past
 472  * the end of the bitmap.
 473  *
 474  */
 475 int netlbl_secattr_catmap_walk_rng(struct netlbl_lsm_secattr_catmap *catmap,
 476                                    u32 offset)
 477 {
 478         struct netlbl_lsm_secattr_catmap *iter = catmap;
 479         u32 node_idx;
 480         u32 node_bit;
 481         NETLBL_CATMAP_MAPTYPE bitmask;
 482         NETLBL_CATMAP_MAPTYPE bitmap;
 483
 484         if (offset > iter->startbit) {
 485                 while (offset >= (iter->startbit + NETLBL_CATMAP_SIZE)) {
 486                         iter = iter->next;
 487                         if (iter == NULL)
 488                                 return -ENOENT;
 489                 }
 490                 node_idx = (offset - iter->startbit) / NETLBL_CATMAP_MAPSIZE;
 491                 node_bit = offset - iter->startbit -
 492                            (NETLBL_CATMAP_MAPSIZE * node_idx);
 493         } else {
 494                 node_idx = 0;
 495                 node_bit = 0;
 496         }
 497         bitmask = NETLBL_CATMAP_BIT << node_bit;
 498
 499         for (;;) {
 500                 bitmap = iter->bitmap[node_idx];
 501                 while (bitmask != 0 && (bitmap & bitmask) != 0) {
 502                         bitmask <<= 1;
 503                         node_bit++;
 504                 }
 505
 506                 if (bitmask != 0)
 507                         return iter->startbit +
 508                                 (NETLBL_CATMAP_MAPSIZE * node_idx) +
 509                                 node_bit - 1;
 510                 else if (++node_idx >= NETLBL_CATMAP_MAPCNT) {
 511                         if (iter->next == NULL)
 512                                 return iter->startbit + NETLBL_CATMAP_SIZE - 1;
 513                         iter = iter->next;
 514                         node_idx = 0;
 515                 }
 516                 bitmask = NETLBL_CATMAP_BIT;
 517                 node_bit = 0;
 518         }
 519
 520         return -ENOENT;
 521 }
 522
 523 /**
 524  * netlbl_secattr_catmap_setbit - Set a bit in a LSM secattr catmap
 525  * @catmap: the category bitmap
 526  * @bit: the bit to set
 527  * @flags: memory allocation flags
 528  *
 529  * Description:
 530  * Set the bit specified by @bit in @catmap.  Returns zero on success,
 531  * negative values on failure.
 532  *
 533  */
 534 int netlbl_secattr_catmap_setbit(struct netlbl_lsm_secattr_catmap *catmap,
 535                                  u32 bit,
 536                                  gfp_t flags)
 537 {
 538         struct netlbl_lsm_secattr_catmap *iter = catmap;
 539         u32 node_bit;
 540         u32 node_idx;
 541
 542         while (iter->next != NULL &&
 543                bit >= (iter->startbit + NETLBL_CATMAP_SIZE))
 544                 iter = iter->next;
 545         if (bit >= (iter->startbit + NETLBL_CATMAP_SIZE)) {
 546                 iter->next = netlbl_secattr_catmap_alloc(flags);
 547                 if (iter->next == NULL)
 548                         return -ENOMEM;
 549                 iter = iter->next;
 550                 iter->startbit = bit & ~(NETLBL_CATMAP_SIZE - 1);
 551         }
 552
 553         /* gcc always rounds to zero when doing integer division */
 554         node_idx = (bit - iter->startbit) / NETLBL_CATMAP_MAPSIZE;
 555         node_bit = bit - iter->startbit - (NETLBL_CATMAP_MAPSIZE * node_idx);
 556         iter->bitmap[node_idx] |= NETLBL_CATMAP_BIT << node_bit;
 557
 558         return 0;
 559 }
 560
 561 /**
 562  * netlbl_secattr_catmap_setrng - Set a range of bits in a LSM secattr catmap
 563  * @catmap: the category bitmap
 564  * @start: the starting bit
 565  * @end: the last bit in the string
 566  * @flags: memory allocation flags
 567  *
 568  * Description:
 569  * Set a range of bits, starting at @start and ending with @end.  Returns zero
 570  * on success, negative values on failure.
 571  *
 572  */
 573 int netlbl_secattr_catmap_setrng(struct netlbl_lsm_secattr_catmap *catmap,
 574                                  u32 start,
 575                                  u32 end,
 576                                  gfp_t flags)
 577 {
 578         int ret_val = 0;
 579         struct netlbl_lsm_secattr_catmap *iter = catmap;
 580         u32 iter_max_spot;
 581         u32 spot;
 582
 583         /* XXX - This could probably be made a bit faster by combining writes
 584          * to the catmap instead of setting a single bit each time, but for
 585          * right now skipping to the start of the range in the catmap should
 586          * be a nice improvement over calling the individual setbit function
 587          * repeatedly from a loop. */
 588
 589         while (iter->next != NULL &&
 590                start >= (iter->startbit + NETLBL_CATMAP_SIZE))
 591                 iter = iter->next;
 592         iter_max_spot = iter->startbit + NETLBL_CATMAP_SIZE;
 593
 594         for (spot = start; spot <= end && ret_val == 0; spot++) {
 595                 if (spot >= iter_max_spot && iter->next != NULL) {
 596                         iter = iter->next;
 597                         iter_max_spot = iter->startbit + NETLBL_CATMAP_SIZE;
 598                 }
 599                 ret_val = netlbl_secattr_catmap_setbit(iter, spot, flags);
 600         }
 601
 602         return ret_val;
 603 }
 604
 605 /*
 606  * LSM Functions
 607  */
 608
 609 /**
 610  * netlbl_enabled - Determine if the NetLabel subsystem is enabled
 611  *
 612  * Description:
 613  * The LSM can use this function to determine if it should use NetLabel
 614  * security attributes in it's enforcement mechanism.  Currently, NetLabel is
 615  * considered to be enabled when it's configuration contains a valid setup for
 616  * at least one labeled protocol (i.e. NetLabel can understand incoming
 617  * labeled packets of at least one type); otherwise NetLabel is considered to
 618  * be disabled.
 619  *
 620  */
 621 int netlbl_enabled(void)
 622 {
 623         /* At some point we probably want to expose this mechanism to the user
 624          * as well so that admins can toggle NetLabel regardless of the
 625          * configuration */
 626         return (atomic_read(&netlabel_mgmt_protocount) > 0);
 627 }
 628
 629 /**
 630  * netlbl_sock_setattr - Label a socket using the correct protocol
 631  * @sk: the socket to label
 632  * @family: protocol family
 633  * @secattr: the security attributes
 634  *
 635  * Description:
 636  * Attach the correct label to the given socket using the security attributes
 637  * specified in @secattr.  This function requires exclusive access to @sk,
 638  * which means it either needs to be in the process of being created or locked.
 639  * Returns zero on success, -EDESTADDRREQ if the domain is configured to use
 640  * network address selectors (can't blindly label the socket), and negative
 641  * values on all other failures.
 642  *
 643  */
 644 int netlbl_sock_setattr(struct sock *sk,
 645                         u16 family,
 646                         const struct netlbl_lsm_secattr *secattr)
 647 {
 648         int ret_val;
 649         struct netlbl_dom_map *dom_entry;
 650
 651         rcu_read_lock();
 652         dom_entry = netlbl_domhsh_getentry(secattr->domain);
 653         if (dom_entry == NULL) {
 654                 ret_val = -ENOENT;
 655                 goto socket_setattr_return;
 656         }
 657         switch (family) {
 658         case AF_INET:
 659                 switch (dom_entry->def.type) {
 660                 case NETLBL_NLTYPE_ADDRSELECT:
 661                         ret_val = -EDESTADDRREQ;
 662                         break;
 663                 case NETLBL_NLTYPE_CIPSOV4:
 664                         ret_val = cipso_v4_sock_setattr(sk,
 665                                                         dom_entry->def.cipso,
 666                                                         secattr);
 667                         break;
 668                 case NETLBL_NLTYPE_UNLABELED:
 669                         ret_val = 0;
 670                         break;
 671                 default:
 672                         ret_val = -ENOENT;
 673                 }
 674                 break;
 675 #if IS_ENABLED(CONFIG_IPV6)
 676         case AF_INET6:
 677                 /* since we don't support any IPv6 labeling protocols right
 678                  * now we can optimize everything away until we do */
 679                 ret_val = 0;
 680                 break;
 681 #endif /* IPv6 */
 682         default:
 683                 ret_val = -EPROTONOSUPPORT;
 684         }
 685
 686 socket_setattr_return:
 687         rcu_read_unlock();
 688         return ret_val;
 689 }
 690
 691 /**
 692  * netlbl_sock_delattr - Delete all the NetLabel labels on a socket
 693  * @sk: the socket
 694  *
 695  * Description:
 696  * Remove all the NetLabel labeling from @sk.  The caller is responsible for
 697  * ensuring that @sk is locked.
 698  *
 699  */
 700 void netlbl_sock_delattr(struct sock *sk)
 701 {
 702         cipso_v4_sock_delattr(sk);
 703 }
 704
 705 /**
 706  * netlbl_sock_getattr - Determine the security attributes of a sock
 707  * @sk: the sock
 708  * @secattr: the security attributes
 709  *
 710  * Description:
 711  * Examines the given sock to see if any NetLabel style labeling has been
 712  * applied to the sock, if so it parses the socket label and returns the
 713  * security attributes in @secattr.  Returns zero on success, negative values
 714  * on failure.
 715  *
 716  */
 717 int netlbl_sock_getattr(struct sock *sk,
 718                         struct netlbl_lsm_secattr *secattr)
 719 {
 720         int ret_val;
 721
 722         switch (sk->sk_family) {
 723         case AF_INET:
 724                 ret_val = cipso_v4_sock_getattr(sk, secattr);
 725                 break;
 726 #if IS_ENABLED(CONFIG_IPV6)
 727         case AF_INET6:
 728                 ret_val = -ENOMSG;
 729                 break;
 730 #endif /* IPv6 */
 731         default:
 732                 ret_val = -EPROTONOSUPPORT;
 733         }
 734
 735         return ret_val;
 736 }
 737
 738 /**
 739  * netlbl_conn_setattr - Label a connected socket using the correct protocol
 740  * @sk: the socket to label
 741  * @addr: the destination address
 742  * @secattr: the security attributes
 743  *
 744  * Description:
 745  * Attach the correct label to the given connected socket using the security
 746  * attributes specified in @secattr.  The caller is responsible for ensuring
 747  * that @sk is locked.  Returns zero on success, negative values on failure.
 748  *
 749  */
 750 int netlbl_conn_setattr(struct sock *sk,
 751                         struct sockaddr *addr,
 752                         const struct netlbl_lsm_secattr *secattr)
 753 {
 754         int ret_val;
 755         struct sockaddr_in *addr4;
 756         struct netlbl_dommap_def *entry;
 757
 758         rcu_read_lock();
 759         switch (addr->sa_family) {
 760         case AF_INET:
 761                 addr4 = (struct sockaddr_in *)addr;
 762                 entry = netlbl_domhsh_getentry_af4(secattr->domain,
 763                                                    addr4->sin_addr.s_addr);
 764                 if (entry == NULL) {
 765                         ret_val = -ENOENT;
 766                         goto conn_setattr_return;
 767                 }
 768                 switch (entry->type) {
 769                 case NETLBL_NLTYPE_CIPSOV4:
 770                         ret_val = cipso_v4_sock_setattr(sk,
 771                                                         entry->cipso, secattr);
 772                         break;
 773                 case NETLBL_NLTYPE_UNLABELED:
 774                         /* just delete the protocols we support for right now
 775                          * but we could remove other protocols if needed */
 776                         cipso_v4_sock_delattr(sk);
 777                         ret_val = 0;
 778                         break;
 779                 default:
 780                         ret_val = -ENOENT;
 781                 }
 782                 break;
 783 #if IS_ENABLED(CONFIG_IPV6)
 784         case AF_INET6:
 785                 /* since we don't support any IPv6 labeling protocols right
 786                  * now we can optimize everything away until we do */
 787                 ret_val = 0;
 788                 break;
 789 #endif /* IPv6 */
 790         default:
 791                 ret_val = -EPROTONOSUPPORT;
 792         }
 793
 794 conn_setattr_return:
 795         rcu_read_unlock();
 796         return ret_val;
 797 }
 798
 799 /**
 800  * netlbl_req_setattr - Label a request socket using the correct protocol
 801  * @req: the request socket to label
 802  * @secattr: the security attributes
 803  *
 804  * Description:
 805  * Attach the correct label to the given socket using the security attributes
 806  * specified in @secattr.  Returns zero on success, negative values on failure.
 807  *
 808  */
 809 int netlbl_req_setattr(struct request_sock *req,
 810                        const struct netlbl_lsm_secattr *secattr)
 811 {
 812         int ret_val;
 813         struct netlbl_dommap_def *entry;
 814
 815         rcu_read_lock();
 816         switch (req->rsk_ops->family) {
 817         case AF_INET:
 818                 entry = netlbl_domhsh_getentry_af4(secattr->domain,
 819                                                    inet_rsk(req)->ir_rmt_addr);
 820                 if (entry == NULL) {
 821                         ret_val = -ENOENT;
 822                         goto req_setattr_return;
 823                 }
 824                 switch (entry->type) {
 825                 case NETLBL_NLTYPE_CIPSOV4:
 826                         ret_val = cipso_v4_req_setattr(req,
 827                                                        entry->cipso, secattr);
 828                         break;
 829                 case NETLBL_NLTYPE_UNLABELED:
 830                         /* just delete the protocols we support for right now
 831                          * but we could remove other protocols if needed */
 832                         cipso_v4_req_delattr(req);
 833                         ret_val = 0;
 834                         break;
 835                 default:
 836                         ret_val = -ENOENT;
 837                 }
 838                 break;
 839 #if IS_ENABLED(CONFIG_IPV6)
 840         case AF_INET6:
 841                 /* since we don't support any IPv6 labeling protocols right
 842                  * now we can optimize everything away until we do */
 843                 ret_val = 0;
 844                 break;
 845 #endif /* IPv6 */
 846         default:
 847                 ret_val = -EPROTONOSUPPORT;
 848         }
 849
 850 req_setattr_return:
 851         rcu_read_unlock();
 852         return ret_val;
 853 }
 854
 855 /**
 856 * netlbl_req_delattr - Delete all the NetLabel labels on a socket
 857 * @req: the socket
 858 *
 859 * Description:
 860 * Remove all the NetLabel labeling from @req.
 861 *
 862 */
 863 void netlbl_req_delattr(struct request_sock *req)
 864 {
 865         cipso_v4_req_delattr(req);
 866 }
 867
 868 /**
 869  * netlbl_skbuff_setattr - Label a packet using the correct protocol
 870  * @skb: the packet
 871  * @family: protocol family
 872  * @secattr: the security attributes
 873  *
 874  * Description:
 875  * Attach the correct label to the given packet using the security attributes
 876  * specified in @secattr.  Returns zero on success, negative values on failure.
 877  *
 878  */
 879 int netlbl_skbuff_setattr(struct sk_buff *skb,
 880                           u16 family,
 881                           const struct netlbl_lsm_secattr *secattr)
 882 {
 883         int ret_val;
 884         struct iphdr *hdr4;
 885         struct netlbl_dommap_def *entry;
 886
 887         rcu_read_lock();
 888         switch (family) {
 889         case AF_INET:
 890                 hdr4 = ip_hdr(skb);
 891                 entry = netlbl_domhsh_getentry_af4(secattr->domain,hdr4->daddr);
 892                 if (entry == NULL) {
 893                         ret_val = -ENOENT;
 894                         goto skbuff_setattr_return;
 895                 }
 896                 switch (entry->type) {
 897                 case NETLBL_NLTYPE_CIPSOV4:
 898                         ret_val = cipso_v4_skbuff_setattr(skb, entry->cipso,
 899                                                           secattr);
 900                         break;
 901                 case NETLBL_NLTYPE_UNLABELED:
 902                         /* just delete the protocols we support for right now
 903                          * but we could remove other protocols if needed */
 904                         ret_val = cipso_v4_skbuff_delattr(skb);
 905                         break;
 906                 default:
 907                         ret_val = -ENOENT;
 908                 }
 909                 break;
 910 #if IS_ENABLED(CONFIG_IPV6)
 911         case AF_INET6:
 912                 /* since we don't support any IPv6 labeling protocols right
 913                  * now we can optimize everything away until we do */
 914                 ret_val = 0;
 915                 break;
 916 #endif /* IPv6 */
 917         default:
 918                 ret_val = -EPROTONOSUPPORT;
 919         }
 920
 921 skbuff_setattr_return:
 922         rcu_read_unlock();
 923         return ret_val;
 924 }
 925
 926 /**
 927  * netlbl_skbuff_getattr - Determine the security attributes of a packet
 928  * @skb: the packet
 929  * @family: protocol family
 930  * @secattr: the security attributes
 931  *
 932  * Description:
 933  * Examines the given packet to see if a recognized form of packet labeling
 934  * is present, if so it parses the packet label and returns the security
 935  * attributes in @secattr.  Returns zero on success, negative values on
 936  * failure.
 937  *
 938  */
 939 int netlbl_skbuff_getattr(const struct sk_buff *skb,
 940                           u16 family,
 941                           struct netlbl_lsm_secattr *secattr)
 942 {
 943         switch (family) {
 944         case AF_INET:
 945                 if (CIPSO_V4_OPTEXIST(skb) &&
 946                     cipso_v4_skbuff_getattr(skb, secattr) == 0)
 947                         return 0;
 948                 break;
 949 #if IS_ENABLED(CONFIG_IPV6)
 950         case AF_INET6:
 951                 break;
 952 #endif /* IPv6 */
 953         }
 954
 955         return netlbl_unlabel_getattr(skb, family, secattr);
 956 }
 957
 958 /**
 959  * netlbl_skbuff_err - Handle a LSM error on a sk_buff
 960  * @skb: the packet
 961  * @error: the error code
 962  * @gateway: true if host is acting as a gateway, false otherwise
 963  *
 964  * Description:
 965  * Deal with a LSM problem when handling the packet in @skb, typically this is
 966  * a permission denied problem (-EACCES).  The correct action is determined
 967  * according to the packet's labeling protocol.
 968  *
 969  */
 970 void netlbl_skbuff_err(struct sk_buff *skb, int error, int gateway)
 971 {
 972         if (CIPSO_V4_OPTEXIST(skb))
 973                 cipso_v4_error(skb, error, gateway);
 974 }
 975
 976 /**
 977  * netlbl_cache_invalidate - Invalidate all of the NetLabel protocol caches
 978  *
 979  * Description:
 980  * For all of the NetLabel protocols that support some form of label mapping
 981  * cache, invalidate the cache.  Returns zero on success, negative values on
 982  * error.
 983  *
 984  */
 985 void netlbl_cache_invalidate(void)
 986 {
 987         cipso_v4_cache_invalidate();
 988 }
 989
 990 /**
 991  * netlbl_cache_add - Add an entry to a NetLabel protocol cache
 992  * @skb: the packet
 993  * @secattr: the packet's security attributes
 994  *
 995  * Description:
 996  * Add the LSM security attributes for the given packet to the underlying
 997  * NetLabel protocol's label mapping cache.  Returns zero on success, negative
 998  * values on error.
 999  *
1000  */
1001 int netlbl_cache_add(const struct sk_buff *skb,
1002                      const struct netlbl_lsm_secattr *secattr)
1003 {
1004         if ((secattr->flags & NETLBL_SECATTR_CACHE) == 0)
1005                 return -ENOMSG;
1006
1007         if (CIPSO_V4_OPTEXIST(skb))
1008                 return cipso_v4_cache_add(skb, secattr);
1009
1010         return -ENOMSG;
1011 }
1012
1013 /*
1014  * Protocol Engine Functions
1015  */
1016
1017 /**
1018  * netlbl_audit_start - Start an audit message
1019  * @type: audit message type
1020  * @audit_info: NetLabel audit information
1021  *
1022  * Description:
1023  * Start an audit message using the type specified in @type and fill the audit
1024  * message with some fields common to all NetLabel audit messages.  This
1025  * function should only be used by protocol engines, not LSMs.  Returns a
1026  * pointer to the audit buffer on success, NULL on failure.
1027  *
1028  */
1029 struct audit_buffer *netlbl_audit_start(int type,
1030                                         struct netlbl_audit *audit_info)
1031 {
1032         return netlbl_audit_start_common(type, audit_info);
1033 }
1034
1035 /*
1036  * Setup Functions
1037  */
1038
1039 /**
1040  * netlbl_init - Initialize NetLabel
1041  *
1042  * Description:
1043  * Perform the required NetLabel initialization before first use.
1044  *
1045  */
1046 static int __init netlbl_init(void)
1047 {
1048         int ret_val;
1049
1050         printk(KERN_INFO "NetLabel: Initializing\n");
1051         printk(KERN_INFO "NetLabel:  domain hash size = %u\n",
1052                (1 << NETLBL_DOMHSH_BITSIZE));
1053         printk(KERN_INFO "NetLabel:  protocols ="
1054                " UNLABELED"
1055                " CIPSOv4"
1056                "\n");
1057
1058         ret_val = netlbl_domhsh_init(NETLBL_DOMHSH_BITSIZE);
1059         if (ret_val != 0)
1060                 goto init_failure;
1061
1062         ret_val = netlbl_unlabel_init(NETLBL_UNLHSH_BITSIZE);
1063         if (ret_val != 0)
1064                 goto init_failure;
1065
1066         ret_val = netlbl_netlink_init();
1067         if (ret_val != 0)
1068                 goto init_failure;
1069
1070         ret_val = netlbl_unlabel_defconf();
1071         if (ret_val != 0)
1072                 goto init_failure;
1073         printk(KERN_INFO "NetLabel:  unlabeled traffic allowed by default\n");
1074
1075         return 0;
1076
1077 init_failure:
1078         panic("NetLabel: failed to initialize properly (%d)\n", ret_val);
1079 }
1080
1081 subsys_initcall(netlbl_init);