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, write to the Free Software
  27  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
  28  *
  29  */
  30
  31 #include <linux/init.h>
  32 #include <linux/types.h>
  33 #include <linux/slab.h>
  34 #include <linux/audit.h>
  35 #include <linux/in.h>
  36 #include <linux/in6.h>
  37 #include <net/ip.h>
  38 #include <net/ipv6.h>
  39 #include <net/netlabel.h>
  40 #include <net/cipso_ipv4.h>
  41 #include <asm/bug.h>
  42 #include <linux/atomic.h>
  43
  44 #include "netlabel_domainhash.h"
  45 #include "netlabel_unlabeled.h"
  46 #include "netlabel_cipso_v4.h"
  47 #include "netlabel_user.h"
  48 #include "netlabel_mgmt.h"
  49 #include "netlabel_addrlist.h"
  50
  51 /*
  52  * Configuration Functions
  53  */
  54
  55 /**
  56  * netlbl_cfg_map_del - Remove a NetLabel/LSM domain mapping
  57  * @domain: the domain mapping to remove
  58  * @family: address family
  59  * @addr: IP address
  60  * @mask: IP address mask
  61  * @audit_info: NetLabel audit information
  62  *
  63  * Description:
  64  * Removes a NetLabel/LSM domain mapping.  A @domain value of NULL causes the
  65  * default domain mapping to be removed.  Returns zero on success, negative
  66  * values on failure.
  67  *
  68  */
  69 int netlbl_cfg_map_del(const char *domain,
  70                        u16 family,
  71                        const void *addr,
  72                        const void *mask,
  73                        struct netlbl_audit *audit_info)
  74 {
  75         if (addr == NULL && mask == NULL) {
  76                 return netlbl_domhsh_remove(domain, audit_info);
  77         } else if (addr != NULL && mask != NULL) {
  78                 switch (family) {
  79                 case AF_INET:
  80                         return netlbl_domhsh_remove_af4(domain, addr, mask,
  81                                                         audit_info);
  82                 default:
  83                         return -EPFNOSUPPORT;
  84                 }
  85         } else
  86                 return -EINVAL;
  87 }
  88
  89 /**
  90  * netlbl_cfg_unlbl_map_add - Add a new unlabeled mapping
  91  * @domain: the domain mapping to add
  92  * @family: address family
  93  * @addr: IP address
  94  * @mask: IP address mask
  95  * @audit_info: NetLabel audit information
  96  *
  97  * Description:
  98  * Adds a new unlabeled NetLabel/LSM domain mapping.  A @domain value of NULL
  99  * causes a new default domain mapping to be added.  Returns zero on success,
 100  * negative values on failure.
 101  *
 102  */
 103 int netlbl_cfg_unlbl_map_add(const char *domain,
 104                              u16 family,
 105                              const void *addr,
 106                              const void *mask,
 107                              struct netlbl_audit *audit_info)
 108 {
 109         int ret_val = -ENOMEM;
 110         struct netlbl_dom_map *entry;
 111         struct netlbl_domaddr_map *addrmap = NULL;
 112         struct netlbl_domaddr4_map *map4 = NULL;
 113         struct netlbl_domaddr6_map *map6 = NULL;
 114
 115         entry = kzalloc(sizeof(*entry), GFP_ATOMIC);
 116         if (entry == NULL)
 117                 return -ENOMEM;
 118         if (domain != NULL) {
 119                 entry->domain = kstrdup(domain, GFP_ATOMIC);
 120                 if (entry->domain == NULL)
 121                         goto cfg_unlbl_map_add_failure;
 122         }
 123
 124         if (addr == NULL && mask == NULL)
 125                 entry->type = NETLBL_NLTYPE_UNLABELED;
 126         else if (addr != NULL && mask != NULL) {
 127                 addrmap = kzalloc(sizeof(*addrmap), GFP_ATOMIC);
 128                 if (addrmap == NULL)
 129                         goto cfg_unlbl_map_add_failure;
 130                 INIT_LIST_HEAD(&addrmap->list4);
 131                 INIT_LIST_HEAD(&addrmap->list6);
 132
 133                 switch (family) {
 134                 case AF_INET: {
 135                         const struct in_addr *addr4 = addr;
 136                         const struct in_addr *mask4 = mask;
 137                         map4 = kzalloc(sizeof(*map4), GFP_ATOMIC);
 138                         if (map4 == NULL)
 139                                 goto cfg_unlbl_map_add_failure;
 140                         map4->type = NETLBL_NLTYPE_UNLABELED;
 141                         map4->list.addr = addr4->s_addr & mask4->s_addr;
 142                         map4->list.mask = mask4->s_addr;
 143                         map4->list.valid = 1;
 144                         ret_val = netlbl_af4list_add(&map4->list,
 145                                                      &addrmap->list4);
 146                         if (ret_val != 0)
 147                                 goto cfg_unlbl_map_add_failure;
 148                         break;
 149                         }
 150 #if IS_ENABLED(CONFIG_IPV6)
 151                 case AF_INET6: {
 152                         const struct in6_addr *addr6 = addr;
 153                         const struct in6_addr *mask6 = mask;
 154                         map6 = kzalloc(sizeof(*map6), GFP_ATOMIC);
 155                         if (map6 == NULL)
 156                                 goto cfg_unlbl_map_add_failure;
 157                         map6->type = NETLBL_NLTYPE_UNLABELED;
 158                         map6->list.addr = *addr6;
 159                         map6->list.addr.s6_addr32[0] &= mask6->s6_addr32[0];
 160                         map6->list.addr.s6_addr32[1] &= mask6->s6_addr32[1];
 161                         map6->list.addr.s6_addr32[2] &= mask6->s6_addr32[2];
 162                         map6->list.addr.s6_addr32[3] &= mask6->s6_addr32[3];
 163                         map6->list.mask = *mask6;
 164                         map6->list.valid = 1;
 165                         ret_val = netlbl_af6list_add(&map6->list,
 166                                                      &addrmap->list6);
 167                         if (ret_val != 0)
 168                                 goto cfg_unlbl_map_add_failure;
 169                         break;
 170                         }
 171 #endif /* IPv6 */
 172                 default:
 173                         goto cfg_unlbl_map_add_failure;
 174                         break;
 175                 }
 176
 177                 entry->type_def.addrsel = addrmap;
 178                 entry->type = NETLBL_NLTYPE_ADDRSELECT;
 179         } else {
 180                 ret_val = -EINVAL;
 181                 goto cfg_unlbl_map_add_failure;
 182         }
 183
 184         ret_val = netlbl_domhsh_add(entry, audit_info);
 185         if (ret_val != 0)
 186                 goto cfg_unlbl_map_add_failure;
 187
 188         return 0;
 189
 190 cfg_unlbl_map_add_failure:
 191         kfree(entry->domain);
 192         kfree(entry);
 193         kfree(addrmap);
 194         kfree(map4);
 195         kfree(map6);
 196         return ret_val;
 197 }
 198
 199
 200 /**
 201  * netlbl_cfg_unlbl_static_add - Adds a new static label
 202  * @net: network namespace
 203  * @dev_name: interface name
 204  * @addr: IP address in network byte order (struct in[6]_addr)
 205  * @mask: address mask in network byte order (struct in[6]_addr)
 206  * @family: address family
 207  * @secid: LSM secid value for the entry
 208  * @audit_info: NetLabel audit information
 209  *
 210  * Description:
 211  * Adds a new NetLabel static label to be used when protocol provided labels
 212  * are not present on incoming traffic.  If @dev_name is NULL then the default
 213  * interface will be used.  Returns zero on success, negative values on failure.
 214  *
 215  */
 216 int netlbl_cfg_unlbl_static_add(struct net *net,
 217                                 const char *dev_name,
 218                                 const void *addr,
 219                                 const void *mask,
 220                                 u16 family,
 221                                 u32 secid,
 222                                 struct netlbl_audit *audit_info)
 223 {
 224         u32 addr_len;
 225
 226         switch (family) {
 227         case AF_INET:
 228                 addr_len = sizeof(struct in_addr);
 229                 break;
 230 #if IS_ENABLED(CONFIG_IPV6)
 231         case AF_INET6:
 232                 addr_len = sizeof(struct in6_addr);
 233                 break;
 234 #endif /* IPv6 */
 235         default:
 236                 return -EPFNOSUPPORT;
 237         }
 238
 239         return netlbl_unlhsh_add(net,
 240                                  dev_name, addr, mask, addr_len,
 241                                  secid, audit_info);
 242 }
 243
 244 /**
 245  * netlbl_cfg_unlbl_static_del - Removes an existing static label
 246  * @net: network namespace
 247  * @dev_name: interface name
 248  * @addr: IP address in network byte order (struct in[6]_addr)
 249  * @mask: address mask in network byte order (struct in[6]_addr)
 250  * @family: address family
 251  * @secid: LSM secid value for the entry
 252  * @audit_info: NetLabel audit information
 253  *
 254  * Description:
 255  * Removes an existing NetLabel static label used when protocol provided labels
 256  * are not present on incoming traffic.  If @dev_name is NULL then the default
 257  * interface will be used.  Returns zero on success, negative values on failure.
 258  *
 259  */
 260 int netlbl_cfg_unlbl_static_del(struct net *net,
 261                                 const char *dev_name,
 262                                 const void *addr,
 263                                 const void *mask,
 264                                 u16 family,
 265                                 struct netlbl_audit *audit_info)
 266 {
 267         u32 addr_len;
 268
 269         switch (family) {
 270         case AF_INET:
 271                 addr_len = sizeof(struct in_addr);
 272                 break;
 273 #if IS_ENABLED(CONFIG_IPV6)
 274         case AF_INET6:
 275                 addr_len = sizeof(struct in6_addr);
 276                 break;
 277 #endif /* IPv6 */
 278         default:
 279                 return -EPFNOSUPPORT;
 280         }
 281
 282         return netlbl_unlhsh_remove(net,
 283                                     dev_name, addr, mask, addr_len,
 284                                     audit_info);
 285 }
 286
 287 /**
 288  * netlbl_cfg_cipsov4_add - Add a new CIPSOv4 DOI definition
 289  * @doi_def: CIPSO DOI definition
 290  * @audit_info: NetLabel audit information
 291  *
 292  * Description:
 293  * Add a new CIPSO DOI definition as defined by @doi_def.  Returns zero on
 294  * success and negative values on failure.
 295  *
 296  */
 297 int netlbl_cfg_cipsov4_add(struct cipso_v4_doi *doi_def,
 298                            struct netlbl_audit *audit_info)
 299 {
 300         return cipso_v4_doi_add(doi_def, audit_info);
 301 }
 302
 303 /**
 304  * netlbl_cfg_cipsov4_del - Remove an existing CIPSOv4 DOI definition
 305  * @doi: CIPSO DOI
 306  * @audit_info: NetLabel audit information
 307  *
 308  * Description:
 309  * Remove an existing CIPSO DOI definition matching @doi.  Returns zero on
 310  * success and negative values on failure.
 311  *
 312  */
 313 void netlbl_cfg_cipsov4_del(u32 doi, struct netlbl_audit *audit_info)
 314 {
 315         cipso_v4_doi_remove(doi, audit_info);
 316 }
 317
 318 /**
 319  * netlbl_cfg_cipsov4_map_add - Add a new CIPSOv4 DOI mapping
 320  * @doi: the CIPSO DOI
 321  * @domain: the domain mapping to add
 322  * @addr: IP address
 323  * @mask: IP address mask
 324  * @audit_info: NetLabel audit information
 325  *
 326  * Description:
 327  * Add a new NetLabel/LSM domain mapping for the given CIPSO DOI to the NetLabel
 328  * subsystem.  A @domain value of NULL adds a new default domain mapping.
 329  * Returns zero on success, negative values on failure.
 330  *
 331  */
 332 int netlbl_cfg_cipsov4_map_add(u32 doi,
 333                                const char *domain,
 334                                const struct in_addr *addr,
 335                                const struct in_addr *mask,
 336                                struct netlbl_audit *audit_info)
 337 {
 338         int ret_val = -ENOMEM;
 339         struct cipso_v4_doi *doi_def;
 340         struct netlbl_dom_map *entry;
 341         struct netlbl_domaddr_map *addrmap = NULL;
 342         struct netlbl_domaddr4_map *addrinfo = NULL;
 343
 344         doi_def = cipso_v4_doi_getdef(doi);
 345         if (doi_def == NULL)
 346                 return -ENOENT;
 347
 348         entry = kzalloc(sizeof(*entry), GFP_ATOMIC);
 349         if (entry == NULL)
 350                 goto out_entry;
 351         if (domain != NULL) {
 352                 entry->domain = kstrdup(domain, GFP_ATOMIC);
 353                 if (entry->domain == NULL)
 354                         goto out_domain;
 355         }
 356
 357         if (addr == NULL && mask == NULL) {
 358                 entry->type_def.cipsov4 = doi_def;
 359                 entry->type = NETLBL_NLTYPE_CIPSOV4;
 360         } else if (addr != NULL && mask != NULL) {
 361                 addrmap = kzalloc(sizeof(*addrmap), GFP_ATOMIC);
 362                 if (addrmap == NULL)
 363                         goto out_addrmap;
 364                 INIT_LIST_HEAD(&addrmap->list4);
 365                 INIT_LIST_HEAD(&addrmap->list6);
 366
 367                 addrinfo = kzalloc(sizeof(*addrinfo), GFP_ATOMIC);
 368                 if (addrinfo == NULL)
 369                         goto out_addrinfo;
 370                 addrinfo->type_def.cipsov4 = doi_def;
 371                 addrinfo->type = NETLBL_NLTYPE_CIPSOV4;
 372                 addrinfo->list.addr = addr->s_addr & mask->s_addr;
 373                 addrinfo->list.mask = mask->s_addr;
 374                 addrinfo->list.valid = 1;
 375                 ret_val = netlbl_af4list_add(&addrinfo->list, &addrmap->list4);
 376                 if (ret_val != 0)
 377                         goto cfg_cipsov4_map_add_failure;
 378
 379                 entry->type_def.addrsel = addrmap;
 380                 entry->type = NETLBL_NLTYPE_ADDRSELECT;
 381         } else {
 382                 ret_val = -EINVAL;
 383                 goto out_addrmap;
 384         }
 385
 386         ret_val = netlbl_domhsh_add(entry, audit_info);
 387         if (ret_val != 0)
 388                 goto cfg_cipsov4_map_add_failure;
 389
 390         return 0;
 391
 392 cfg_cipsov4_map_add_failure:
 393         kfree(addrinfo);
 394 out_addrinfo:
 395         kfree(addrmap);
 396 out_addrmap:
 397         kfree(entry->domain);
 398 out_domain:
 399         kfree(entry);
 400 out_entry:
 401         cipso_v4_doi_putdef(doi_def);
 402         return ret_val;
 403 }
 404
 405 /*
 406  * Security Attribute Functions
 407  */
 408
 409 /**
 410  * netlbl_secattr_catmap_walk - Walk a LSM secattr catmap looking for a bit
 411  * @catmap: the category bitmap
 412  * @offset: the offset to start searching at, in bits
 413  *
 414  * Description:
 415  * This function walks a LSM secattr category bitmap starting at @offset and
 416  * returns the spot of the first set bit or -ENOENT if no bits are set.
 417  *
 418  */
 419 int netlbl_secattr_catmap_walk(struct netlbl_lsm_secattr_catmap *catmap,
 420                                u32 offset)
 421 {
 422         struct netlbl_lsm_secattr_catmap *iter = catmap;
 423         u32 node_idx;
 424         u32 node_bit;
 425         NETLBL_CATMAP_MAPTYPE bitmap;
 426
 427         if (offset > iter->startbit) {
 428                 while (offset >= (iter->startbit + NETLBL_CATMAP_SIZE)) {
 429                         iter = iter->next;
 430                         if (iter == NULL)
 431                                 return -ENOENT;
 432                 }
 433                 node_idx = (offset - iter->startbit) / NETLBL_CATMAP_MAPSIZE;
 434                 node_bit = offset - iter->startbit -
 435                            (NETLBL_CATMAP_MAPSIZE * node_idx);
 436         } else {
 437                 node_idx = 0;
 438                 node_bit = 0;
 439         }
 440         bitmap = iter->bitmap[node_idx] >> node_bit;
 441
 442         for (;;) {
 443                 if (bitmap != 0) {
 444                         while ((bitmap & NETLBL_CATMAP_BIT) == 0) {
 445                                 bitmap >>= 1;
 446                                 node_bit++;
 447                         }
 448                         return iter->startbit +
 449                                 (NETLBL_CATMAP_MAPSIZE * node_idx) + node_bit;
 450                 }
 451                 if (++node_idx >= NETLBL_CATMAP_MAPCNT) {
 452                         if (iter->next != NULL) {
 453                                 iter = iter->next;
 454                                 node_idx = 0;
 455                         } else
 456                                 return -ENOENT;
 457                 }
 458                 bitmap = iter->bitmap[node_idx];
 459                 node_bit = 0;
 460         }
 461
 462         return -ENOENT;
 463 }
 464
 465 /**
 466  * netlbl_secattr_catmap_walk_rng - Find the end of a string of set bits
 467  * @catmap: the category bitmap
 468  * @offset: the offset to start searching at, in bits
 469  *
 470  * Description:
 471  * This function walks a LSM secattr category bitmap starting at @offset and
 472  * returns the spot of the first cleared bit or -ENOENT if the offset is past
 473  * the end of the bitmap.
 474  *
 475  */
 476 int netlbl_secattr_catmap_walk_rng(struct netlbl_lsm_secattr_catmap *catmap,
 477                                    u32 offset)
 478 {
 479         struct netlbl_lsm_secattr_catmap *iter = catmap;
 480         u32 node_idx;
 481         u32 node_bit;
 482         NETLBL_CATMAP_MAPTYPE bitmask;
 483         NETLBL_CATMAP_MAPTYPE bitmap;
 484
 485         if (offset > iter->startbit) {
 486                 while (offset >= (iter->startbit + NETLBL_CATMAP_SIZE)) {
 487                         iter = iter->next;
 488                         if (iter == NULL)
 489                                 return -ENOENT;
 490                 }
 491                 node_idx = (offset - iter->startbit) / NETLBL_CATMAP_MAPSIZE;
 492                 node_bit = offset - iter->startbit -
 493                            (NETLBL_CATMAP_MAPSIZE * node_idx);
 494         } else {
 495                 node_idx = 0;
 496                 node_bit = 0;
 497         }
 498         bitmask = NETLBL_CATMAP_BIT << node_bit;
 499
 500         for (;;) {
 501                 bitmap = iter->bitmap[node_idx];
 502                 while (bitmask != 0 && (bitmap & bitmask) != 0) {
 503                         bitmask <<= 1;
 504                         node_bit++;
 505                 }
 506
 507                 if (bitmask != 0)
 508                         return iter->startbit +
 509                                 (NETLBL_CATMAP_MAPSIZE * node_idx) +
 510                                 node_bit - 1;
 511                 else if (++node_idx >= NETLBL_CATMAP_MAPCNT) {
 512                         if (iter->next == NULL)
 513                                 return iter->startbit + NETLBL_CATMAP_SIZE - 1;
 514                         iter = iter->next;
 515                         node_idx = 0;
 516                 }
 517                 bitmask = NETLBL_CATMAP_BIT;
 518                 node_bit = 0;
 519         }
 520
 521         return -ENOENT;
 522 }
 523
 524 /**
 525  * netlbl_secattr_catmap_setbit - Set a bit in a LSM secattr catmap
 526  * @catmap: the category bitmap
 527  * @bit: the bit to set
 528  * @flags: memory allocation flags
 529  *
 530  * Description:
 531  * Set the bit specified by @bit in @catmap.  Returns zero on success,
 532  * negative values on failure.
 533  *
 534  */
 535 int netlbl_secattr_catmap_setbit(struct netlbl_lsm_secattr_catmap *catmap,
 536                                  u32 bit,
 537                                  gfp_t flags)
 538 {
 539         struct netlbl_lsm_secattr_catmap *iter = catmap;
 540         u32 node_bit;
 541         u32 node_idx;
 542
 543         while (iter->next != NULL &&
 544                bit >= (iter->startbit + NETLBL_CATMAP_SIZE))
 545                 iter = iter->next;
 546         if (bit >= (iter->startbit + NETLBL_CATMAP_SIZE)) {
 547                 iter->next = netlbl_secattr_catmap_alloc(flags);
 548                 if (iter->next == NULL)
 549                         return -ENOMEM;
 550                 iter = iter->next;
 551                 iter->startbit = bit & ~(NETLBL_CATMAP_SIZE - 1);
 552         }
 553
 554         /* gcc always rounds to zero when doing integer division */
 555         node_idx = (bit - iter->startbit) / NETLBL_CATMAP_MAPSIZE;
 556         node_bit = bit - iter->startbit - (NETLBL_CATMAP_MAPSIZE * node_idx);
 557         iter->bitmap[node_idx] |= NETLBL_CATMAP_BIT << node_bit;
 558
 559         return 0;
 560 }
 561
 562 /**
 563  * netlbl_secattr_catmap_setrng - Set a range of bits in a LSM secattr catmap
 564  * @catmap: the category bitmap
 565  * @start: the starting bit
 566  * @end: the last bit in the string
 567  * @flags: memory allocation flags
 568  *
 569  * Description:
 570  * Set a range of bits, starting at @start and ending with @end.  Returns zero
 571  * on success, negative values on failure.
 572  *
 573  */
 574 int netlbl_secattr_catmap_setrng(struct netlbl_lsm_secattr_catmap *catmap,
 575                                  u32 start,
 576                                  u32 end,
 577                                  gfp_t flags)
 578 {
 579         int ret_val = 0;
 580         struct netlbl_lsm_secattr_catmap *iter = catmap;
 581         u32 iter_max_spot;
 582         u32 spot;
 583
 584         /* XXX - This could probably be made a bit faster by combining writes
 585          * to the catmap instead of setting a single bit each time, but for
 586          * right now skipping to the start of the range in the catmap should
 587          * be a nice improvement over calling the individual setbit function
 588          * repeatedly from a loop. */
 589
 590         while (iter->next != NULL &&
 591                start >= (iter->startbit + NETLBL_CATMAP_SIZE))
 592                 iter = iter->next;
 593         iter_max_spot = iter->startbit + NETLBL_CATMAP_SIZE;
 594
 595         for (spot = start; spot <= end && ret_val == 0; spot++) {
 596                 if (spot >= iter_max_spot && iter->next != NULL) {
 597                         iter = iter->next;
 598                         iter_max_spot = iter->startbit + NETLBL_CATMAP_SIZE;
 599                 }
 600                 ret_val = netlbl_secattr_catmap_setbit(iter, spot, flags);
 601         }
 602
 603         return ret_val;
 604 }
 605
 606 /*
 607  * LSM Functions
 608  */
 609
 610 /**
 611  * netlbl_enabled - Determine if the NetLabel subsystem is enabled
 612  *
 613  * Description:
 614  * The LSM can use this function to determine if it should use NetLabel
 615  * security attributes in it's enforcement mechanism.  Currently, NetLabel is
 616  * considered to be enabled when it's configuration contains a valid setup for
 617  * at least one labeled protocol (i.e. NetLabel can understand incoming
 618  * labeled packets of at least one type); otherwise NetLabel is considered to
 619  * be disabled.
 620  *
 621  */
 622 int netlbl_enabled(void)
 623 {
 624         /* At some point we probably want to expose this mechanism to the user
 625          * as well so that admins can toggle NetLabel regardless of the
 626          * configuration */
 627         return (atomic_read(&netlabel_mgmt_protocount) > 0);
 628 }
 629
 630 /**
 631  * netlbl_sock_setattr - Label a socket using the correct protocol
 632  * @sk: the socket to label
 633  * @family: protocol family
 634  * @secattr: the security attributes
 635  *
 636  * Description:
 637  * Attach the correct label to the given socket using the security attributes
 638  * specified in @secattr.  This function requires exclusive access to @sk,
 639  * which means it either needs to be in the process of being created or locked.
 640  * Returns zero on success, -EDESTADDRREQ if the domain is configured to use
 641  * network address selectors (can't blindly label the socket), and negative
 642  * values on all other failures.
 643  *
 644  */
 645 int netlbl_sock_setattr(struct sock *sk,
 646                         u16 family,
 647                         const struct netlbl_lsm_secattr *secattr)
 648 {
 649         int ret_val;
 650         struct netlbl_dom_map *dom_entry;
 651
 652         rcu_read_lock();
 653         dom_entry = netlbl_domhsh_getentry(secattr->domain);
 654         if (dom_entry == NULL) {
 655                 ret_val = -ENOENT;
 656                 goto socket_setattr_return;
 657         }
 658         switch (family) {
 659         case AF_INET:
 660                 switch (dom_entry->type) {
 661                 case NETLBL_NLTYPE_ADDRSELECT:
 662                         ret_val = -EDESTADDRREQ;
 663                         break;
 664                 case NETLBL_NLTYPE_CIPSOV4:
 665                         ret_val = cipso_v4_sock_setattr(sk,
 666                                                     dom_entry->type_def.cipsov4,
 667                                                     secattr);
 668                         break;
 669                 case NETLBL_NLTYPE_UNLABELED:
 670                         ret_val = 0;
 671                         break;
 672                 default:
 673                         ret_val = -ENOENT;
 674                 }
 675                 break;
 676 #if IS_ENABLED(CONFIG_IPV6)
 677         case AF_INET6:
 678                 /* since we don't support any IPv6 labeling protocols right
 679                  * now we can optimize everything away until we do */
 680                 ret_val = 0;
 681                 break;
 682 #endif /* IPv6 */
 683         default:
 684                 ret_val = -EPROTONOSUPPORT;
 685         }
 686
 687 socket_setattr_return:
 688         rcu_read_unlock();
 689         return ret_val;
 690 }
 691
 692 /**
 693  * netlbl_sock_delattr - Delete all the NetLabel labels on a socket
 694  * @sk: the socket
 695  *
 696  * Description:
 697  * Remove all the NetLabel labeling from @sk.  The caller is responsible for
 698  * ensuring that @sk is locked.
 699  *
 700  */
 701 void netlbl_sock_delattr(struct sock *sk)
 702 {
 703         cipso_v4_sock_delattr(sk);
 704 }
 705
 706 /**
 707  * netlbl_sock_getattr - Determine the security attributes of a sock
 708  * @sk: the sock
 709  * @secattr: the security attributes
 710  *
 711  * Description:
 712  * Examines the given sock to see if any NetLabel style labeling has been
 713  * applied to the sock, if so it parses the socket label and returns the
 714  * security attributes in @secattr.  Returns zero on success, negative values
 715  * on failure.
 716  *
 717  */
 718 int netlbl_sock_getattr(struct sock *sk,
 719                         struct netlbl_lsm_secattr *secattr)
 720 {
 721         int ret_val;
 722
 723         switch (sk->sk_family) {
 724         case AF_INET:
 725                 ret_val = cipso_v4_sock_getattr(sk, secattr);
 726                 break;
 727 #if IS_ENABLED(CONFIG_IPV6)
 728         case AF_INET6:
 729                 ret_val = -ENOMSG;
 730                 break;
 731 #endif /* IPv6 */
 732         default:
 733                 ret_val = -EPROTONOSUPPORT;
 734         }
 735
 736         return ret_val;
 737 }
 738
 739 /**
 740  * netlbl_conn_setattr - Label a connected socket using the correct protocol
 741  * @sk: the socket to label
 742  * @addr: the destination address
 743  * @secattr: the security attributes
 744  *
 745  * Description:
 746  * Attach the correct label to the given connected socket using the security
 747  * attributes specified in @secattr.  The caller is responsible for ensuring
 748  * that @sk is locked.  Returns zero on success, negative values on failure.
 749  *
 750  */
 751 int netlbl_conn_setattr(struct sock *sk,
 752                         struct sockaddr *addr,
 753                         const struct netlbl_lsm_secattr *secattr)
 754 {
 755         int ret_val;
 756         struct sockaddr_in *addr4;
 757         struct netlbl_domaddr4_map *af4_entry;
 758
 759         rcu_read_lock();
 760         switch (addr->sa_family) {
 761         case AF_INET:
 762                 addr4 = (struct sockaddr_in *)addr;
 763                 af4_entry = netlbl_domhsh_getentry_af4(secattr->domain,
 764                                                        addr4->sin_addr.s_addr);
 765                 if (af4_entry == NULL) {
 766                         ret_val = -ENOENT;
 767                         goto conn_setattr_return;
 768                 }
 769                 switch (af4_entry->type) {
 770                 case NETLBL_NLTYPE_CIPSOV4:
 771                         ret_val = cipso_v4_sock_setattr(sk,
 772                                                    af4_entry->type_def.cipsov4,
 773                                                    secattr);
 774                         break;
 775                 case NETLBL_NLTYPE_UNLABELED:
 776                         /* just delete the protocols we support for right now
 777                          * but we could remove other protocols if needed */
 778                         cipso_v4_sock_delattr(sk);
 779                         ret_val = 0;
 780                         break;
 781                 default:
 782                         ret_val = -ENOENT;
 783                 }
 784                 break;
 785 #if IS_ENABLED(CONFIG_IPV6)
 786         case AF_INET6:
 787                 /* since we don't support any IPv6 labeling protocols right
 788                  * now we can optimize everything away until we do */
 789                 ret_val = 0;
 790                 break;
 791 #endif /* IPv6 */
 792         default:
 793                 ret_val = -EPROTONOSUPPORT;
 794         }
 795
 796 conn_setattr_return:
 797         rcu_read_unlock();
 798         return ret_val;
 799 }
 800
 801 /**
 802  * netlbl_req_setattr - Label a request socket using the correct protocol
 803  * @req: the request socket to label
 804  * @secattr: the security attributes
 805  *
 806  * Description:
 807  * Attach the correct label to the given socket using the security attributes
 808  * specified in @secattr.  Returns zero on success, negative values on failure.
 809  *
 810  */
 811 int netlbl_req_setattr(struct request_sock *req,
 812                        const struct netlbl_lsm_secattr *secattr)
 813 {
 814         int ret_val;
 815         struct netlbl_dom_map *dom_entry;
 816         struct netlbl_domaddr4_map *af4_entry;
 817         u32 proto_type;
 818         struct cipso_v4_doi *proto_cv4;
 819
 820         rcu_read_lock();
 821         dom_entry = netlbl_domhsh_getentry(secattr->domain);
 822         if (dom_entry == NULL) {
 823                 ret_val = -ENOENT;
 824                 goto req_setattr_return;
 825         }
 826         switch (req->rsk_ops->family) {
 827         case AF_INET:
 828                 if (dom_entry->type == NETLBL_NLTYPE_ADDRSELECT) {
 829                         struct inet_request_sock *req_inet = inet_rsk(req);
 830                         af4_entry = netlbl_domhsh_getentry_af4(secattr->domain,
 831                                                             req_inet->rmt_addr);
 832                         if (af4_entry == NULL) {
 833                                 ret_val = -ENOENT;
 834                                 goto req_setattr_return;
 835                         }
 836                         proto_type = af4_entry->type;
 837                         proto_cv4 = af4_entry->type_def.cipsov4;
 838                 } else {
 839                         proto_type = dom_entry->type;
 840                         proto_cv4 = dom_entry->type_def.cipsov4;
 841                 }
 842                 switch (proto_type) {
 843                 case NETLBL_NLTYPE_CIPSOV4:
 844                         ret_val = cipso_v4_req_setattr(req, proto_cv4, secattr);
 845                         break;
 846                 case NETLBL_NLTYPE_UNLABELED:
 847                         /* just delete the protocols we support for right now
 848                          * but we could remove other protocols if needed */
 849                         cipso_v4_req_delattr(req);
 850                         ret_val = 0;
 851                         break;
 852                 default:
 853                         ret_val = -ENOENT;
 854                 }
 855                 break;
 856 #if IS_ENABLED(CONFIG_IPV6)
 857         case AF_INET6:
 858                 /* since we don't support any IPv6 labeling protocols right
 859                  * now we can optimize everything away until we do */
 860                 ret_val = 0;
 861                 break;
 862 #endif /* IPv6 */
 863         default:
 864                 ret_val = -EPROTONOSUPPORT;
 865         }
 866
 867 req_setattr_return:
 868         rcu_read_unlock();
 869         return ret_val;
 870 }
 871
 872 /**
 873 * netlbl_req_delattr - Delete all the NetLabel labels on a socket
 874 * @req: the socket
 875 *
 876 * Description:
 877 * Remove all the NetLabel labeling from @req.
 878 *
 879 */
 880 void netlbl_req_delattr(struct request_sock *req)
 881 {
 882         cipso_v4_req_delattr(req);
 883 }
 884
 885 /**
 886  * netlbl_skbuff_setattr - Label a packet using the correct protocol
 887  * @skb: the packet
 888  * @family: protocol family
 889  * @secattr: the security attributes
 890  *
 891  * Description:
 892  * Attach the correct label to the given packet using the security attributes
 893  * specified in @secattr.  Returns zero on success, negative values on failure.
 894  *
 895  */
 896 int netlbl_skbuff_setattr(struct sk_buff *skb,
 897                           u16 family,
 898                           const struct netlbl_lsm_secattr *secattr)
 899 {
 900         int ret_val;
 901         struct iphdr *hdr4;
 902         struct netlbl_domaddr4_map *af4_entry;
 903
 904         rcu_read_lock();
 905         switch (family) {
 906         case AF_INET:
 907                 hdr4 = ip_hdr(skb);
 908                 af4_entry = netlbl_domhsh_getentry_af4(secattr->domain,
 909                                                        hdr4->daddr);
 910                 if (af4_entry == NULL) {
 911                         ret_val = -ENOENT;
 912                         goto skbuff_setattr_return;
 913                 }
 914                 switch (af4_entry->type) {
 915                 case NETLBL_NLTYPE_CIPSOV4:
 916                         ret_val = cipso_v4_skbuff_setattr(skb,
 917                                                    af4_entry->type_def.cipsov4,
 918                                                    secattr);
 919                         break;
 920                 case NETLBL_NLTYPE_UNLABELED:
 921                         /* just delete the protocols we support for right now
 922                          * but we could remove other protocols if needed */
 923                         ret_val = cipso_v4_skbuff_delattr(skb);
 924                         break;
 925                 default:
 926                         ret_val = -ENOENT;
 927                 }
 928                 break;
 929 #if IS_ENABLED(CONFIG_IPV6)
 930         case AF_INET6:
 931                 /* since we don't support any IPv6 labeling protocols right
 932                  * now we can optimize everything away until we do */
 933                 ret_val = 0;
 934                 break;
 935 #endif /* IPv6 */
 936         default:
 937                 ret_val = -EPROTONOSUPPORT;
 938         }
 939
 940 skbuff_setattr_return:
 941         rcu_read_unlock();
 942         return ret_val;
 943 }
 944
 945 /**
 946  * netlbl_skbuff_getattr - Determine the security attributes of a packet
 947  * @skb: the packet
 948  * @family: protocol family
 949  * @secattr: the security attributes
 950  *
 951  * Description:
 952  * Examines the given packet to see if a recognized form of packet labeling
 953  * is present, if so it parses the packet label and returns the security
 954  * attributes in @secattr.  Returns zero on success, negative values on
 955  * failure.
 956  *
 957  */
 958 int netlbl_skbuff_getattr(const struct sk_buff *skb,
 959                           u16 family,
 960                           struct netlbl_lsm_secattr *secattr)
 961 {
 962         switch (family) {
 963         case AF_INET:
 964                 if (CIPSO_V4_OPTEXIST(skb) &&
 965                     cipso_v4_skbuff_getattr(skb, secattr) == 0)
 966                         return 0;
 967                 break;
 968 #if IS_ENABLED(CONFIG_IPV6)
 969         case AF_INET6:
 970                 break;
 971 #endif /* IPv6 */
 972         }
 973
 974         return netlbl_unlabel_getattr(skb, family, secattr);
 975 }
 976
 977 /**
 978  * netlbl_skbuff_err - Handle a LSM error on a sk_buff
 979  * @skb: the packet
 980  * @error: the error code
 981  * @gateway: true if host is acting as a gateway, false otherwise
 982  *
 983  * Description:
 984  * Deal with a LSM problem when handling the packet in @skb, typically this is
 985  * a permission denied problem (-EACCES).  The correct action is determined
 986  * according to the packet's labeling protocol.
 987  *
 988  */
 989 void netlbl_skbuff_err(struct sk_buff *skb, int error, int gateway)
 990 {
 991         if (CIPSO_V4_OPTEXIST(skb))
 992                 cipso_v4_error(skb, error, gateway);
 993 }
 994
 995 /**
 996  * netlbl_cache_invalidate - Invalidate all of the NetLabel protocol caches
 997  *
 998  * Description:
 999  * For all of the NetLabel protocols that support some form of label mapping
1000  * cache, invalidate the cache.  Returns zero on success, negative values on
1001  * error.
1002  *
1003  */
1004 void netlbl_cache_invalidate(void)
1005 {
1006         cipso_v4_cache_invalidate();
1007 }
1008
1009 /**
1010  * netlbl_cache_add - Add an entry to a NetLabel protocol cache
1011  * @skb: the packet
1012  * @secattr: the packet's security attributes
1013  *
1014  * Description:
1015  * Add the LSM security attributes for the given packet to the underlying
1016  * NetLabel protocol's label mapping cache.  Returns zero on success, negative
1017  * values on error.
1018  *
1019  */
1020 int netlbl_cache_add(const struct sk_buff *skb,
1021                      const struct netlbl_lsm_secattr *secattr)
1022 {
1023         if ((secattr->flags & NETLBL_SECATTR_CACHE) == 0)
1024                 return -ENOMSG;
1025
1026         if (CIPSO_V4_OPTEXIST(skb))
1027                 return cipso_v4_cache_add(skb, secattr);
1028
1029         return -ENOMSG;
1030 }
1031
1032 /*
1033  * Protocol Engine Functions
1034  */
1035
1036 /**
1037  * netlbl_audit_start - Start an audit message
1038  * @type: audit message type
1039  * @audit_info: NetLabel audit information
1040  *
1041  * Description:
1042  * Start an audit message using the type specified in @type and fill the audit
1043  * message with some fields common to all NetLabel audit messages.  This
1044  * function should only be used by protocol engines, not LSMs.  Returns a
1045  * pointer to the audit buffer on success, NULL on failure.
1046  *
1047  */
1048 struct audit_buffer *netlbl_audit_start(int type,
1049                                         struct netlbl_audit *audit_info)
1050 {
1051         return netlbl_audit_start_common(type, audit_info);
1052 }
1053
1054 /*
1055  * Setup Functions
1056  */
1057
1058 /**
1059  * netlbl_init - Initialize NetLabel
1060  *
1061  * Description:
1062  * Perform the required NetLabel initialization before first use.
1063  *
1064  */
1065 static int __init netlbl_init(void)
1066 {
1067         int ret_val;
1068
1069         printk(KERN_INFO "NetLabel: Initializing\n");
1070         printk(KERN_INFO "NetLabel:  domain hash size = %u\n",
1071                (1 << NETLBL_DOMHSH_BITSIZE));
1072         printk(KERN_INFO "NetLabel:  protocols ="
1073                " UNLABELED"
1074                " CIPSOv4"
1075                "\n");
1076
1077         ret_val = netlbl_domhsh_init(NETLBL_DOMHSH_BITSIZE);
1078         if (ret_val != 0)
1079                 goto init_failure;
1080
1081         ret_val = netlbl_unlabel_init(NETLBL_UNLHSH_BITSIZE);
1082         if (ret_val != 0)
1083                 goto init_failure;
1084
1085         ret_val = netlbl_netlink_init();
1086         if (ret_val != 0)
1087                 goto init_failure;
1088
1089         ret_val = netlbl_unlabel_defconf();
1090         if (ret_val != 0)
1091                 goto init_failure;
1092         printk(KERN_INFO "NetLabel:  unlabeled traffic allowed by default\n");
1093
1094         return 0;
1095
1096 init_failure:
1097         panic("NetLabel: failed to initialize properly (%d)\n", ret_val);
1098 }
1099
1100 subsys_initcall(netlbl_init);