include/net/netlabel.h

   1 /*
   2  * NetLabel System
   3  *
   4  * The NetLabel system manages static and dynamic label mappings for network
   5  * protocols such as CIPSO and RIPSO.
   6  *
   7  * Author: Paul Moore <paul@paul-moore.com>
   8  *
   9  */
  10
  11 /*
  12  * (c) Copyright Hewlett-Packard Development Company, L.P., 2006, 2008
  13  *
  14  * This program is free software;  you can redistribute it and/or modify
  15  * it under the terms of the GNU General Public License as published by
  16  * the Free Software Foundation; either version 2 of the License, or
  17  * (at your option) any later version.
  18  *
  19  * This program is distributed in the hope that it will be useful,
  20  * but WITHOUT ANY WARRANTY;  without even the implied warranty of
  21  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See
  22  * the GNU General Public License for more details.
  23  *
  24  * You should have received a copy of the GNU General Public License
  25  * along with this program;  if not, see <http://www.gnu.org/licenses/>.
  26  *
  27  */
  28
  29 #ifndef _NETLABEL_H
  30 #define _NETLABEL_H
  31
  32 #include <linux/types.h>
  33 #include <linux/slab.h>
  34 #include <linux/net.h>
  35 #include <linux/skbuff.h>
  36 #include <linux/in.h>
  37 #include <linux/in6.h>
  38 #include <net/netlink.h>
  39 #include <net/request_sock.h>
  40 #include <linux/atomic.h>
  41
  42 struct cipso_v4_doi;
  43
  44 /*
  45  * NetLabel - A management interface for maintaining network packet label
  46  *            mapping tables for explicit packet labling protocols.
  47  *
  48  * Network protocols such as CIPSO and RIPSO require a label translation layer
  49  * to convert the label on the packet into something meaningful on the host
  50  * machine.  In the current Linux implementation these mapping tables live
  51  * inside the kernel; NetLabel provides a mechanism for user space applications
  52  * to manage these mapping tables.
  53  *
  54  * NetLabel makes use of the Generic NETLINK mechanism as a transport layer to
  55  * send messages between kernel and user space.  The general format of a
  56  * NetLabel message is shown below:
  57  *
  58  *  +-----------------+-------------------+--------- --- -- -
  59  *  | struct nlmsghdr | struct genlmsghdr | payload
  60  *  +-----------------+-------------------+--------- --- -- -
  61  *
  62  * The 'nlmsghdr' and 'genlmsghdr' structs should be dealt with like normal.
  63  * The payload is dependent on the subsystem specified in the
  64  * 'nlmsghdr->nlmsg_type' and should be defined below, supporting functions
  65  * should be defined in the corresponding net/netlabel/netlabel_<subsys>.h|c
  66  * file.  All of the fields in the NetLabel payload are NETLINK attributes, see
  67  * the include/net/netlink.h file for more information on NETLINK attributes.
  68  *
  69  */
  70
  71 /*
  72  * NetLabel NETLINK protocol
  73  */
  74
  75 /* NetLabel NETLINK protocol version
  76  *  1: initial version
  77  *  2: added static labels for unlabeled connections
  78  *  3: network selectors added to the NetLabel/LSM domain mapping and the
  79  *     CIPSO_V4_MAP_LOCAL CIPSO mapping was added
  80  */
  81 #define NETLBL_PROTO_VERSION            3
  82
  83 /* NetLabel NETLINK types/families */
  84 #define NETLBL_NLTYPE_NONE              0
  85 #define NETLBL_NLTYPE_MGMT              1
  86 #define NETLBL_NLTYPE_MGMT_NAME         "NLBL_MGMT"
  87 #define NETLBL_NLTYPE_RIPSO             2
  88 #define NETLBL_NLTYPE_RIPSO_NAME        "NLBL_RIPSO"
  89 #define NETLBL_NLTYPE_CIPSOV4           3
  90 #define NETLBL_NLTYPE_CIPSOV4_NAME      "NLBL_CIPSOv4"
  91 #define NETLBL_NLTYPE_CIPSOV6           4
  92 #define NETLBL_NLTYPE_CIPSOV6_NAME      "NLBL_CIPSOv6"
  93 #define NETLBL_NLTYPE_UNLABELED         5
  94 #define NETLBL_NLTYPE_UNLABELED_NAME    "NLBL_UNLBL"
  95 #define NETLBL_NLTYPE_ADDRSELECT        6
  96 #define NETLBL_NLTYPE_ADDRSELECT_NAME   "NLBL_ADRSEL"
  97
  98 /*
  99  * NetLabel - Kernel API for accessing the network packet label mappings.
 100  *
 101  * The following functions are provided for use by other kernel modules,
 102  * specifically kernel LSM modules, to provide a consistent, transparent API
 103  * for dealing with explicit packet labeling protocols such as CIPSO and
 104  * RIPSO.  The functions defined here are implemented in the
 105  * net/netlabel/netlabel_kapi.c file.
 106  *
 107  */
 108
 109 /* NetLabel audit information */
 110 struct netlbl_audit {
 111         u32 secid;
 112         kuid_t loginuid;
 113         unsigned int sessionid;
 114 };
 115
 116 /*
 117  * LSM security attributes
 118  */
 119
 120 /**
 121  * struct netlbl_lsm_cache - NetLabel LSM security attribute cache
 122  * @refcount: atomic reference counter
 123  * @free: LSM supplied function to free the cache data
 124  * @data: LSM supplied cache data
 125  *
 126  * Description:
 127  * This structure is provided for LSMs which wish to make use of the NetLabel
 128  * caching mechanism to store LSM specific data/attributes in the NetLabel
 129  * cache.  If the LSM has to perform a lot of translation from the NetLabel
 130  * security attributes into it's own internal representation then the cache
 131  * mechanism can provide a way to eliminate some or all of that translation
 132  * overhead on a cache hit.
 133  *
 134  */
 135 struct netlbl_lsm_cache {
 136         atomic_t refcount;
 137         void (*free) (const void *data);
 138         void *data;
 139 };
 140
 141 /**
 142  * struct netlbl_lsm_catmap - NetLabel LSM secattr category bitmap
 143  * @startbit: the value of the lowest order bit in the bitmap
 144  * @bitmap: the category bitmap
 145  * @next: pointer to the next bitmap "node" or NULL
 146  *
 147  * Description:
 148  * This structure is used to represent category bitmaps.  Due to the large
 149  * number of categories supported by most labeling protocols it is not
 150  * practical to transfer a full bitmap internally so NetLabel adopts a sparse
 151  * bitmap structure modeled after SELinux's ebitmap structure.
 152  * The catmap bitmap field MUST be a power of two in length and large
 153  * enough to hold at least 240 bits.  Special care (i.e. check the code!)
 154  * should be used when changing these values as the LSM implementation
 155  * probably has functions which rely on the sizes of these types to speed
 156  * processing.
 157  *
 158  */
 159 #define NETLBL_CATMAP_MAPTYPE           u64
 160 #define NETLBL_CATMAP_MAPCNT            4
 161 #define NETLBL_CATMAP_MAPSIZE           (sizeof(NETLBL_CATMAP_MAPTYPE) * 8)
 162 #define NETLBL_CATMAP_SIZE              (NETLBL_CATMAP_MAPSIZE * \
 163                                          NETLBL_CATMAP_MAPCNT)
 164 #define NETLBL_CATMAP_BIT               (NETLBL_CATMAP_MAPTYPE)0x01
 165 struct netlbl_lsm_catmap {
 166         u32 startbit;
 167         NETLBL_CATMAP_MAPTYPE bitmap[NETLBL_CATMAP_MAPCNT];
 168         struct netlbl_lsm_catmap *next;
 169 };
 170
 171 /**
 172  * struct netlbl_lsm_secattr - NetLabel LSM security attributes
 173  * @flags: indicate structure attributes, see NETLBL_SECATTR_*
 174  * @type: indicate the NLTYPE of the attributes
 175  * @domain: the NetLabel LSM domain
 176  * @cache: NetLabel LSM specific cache
 177  * @attr.mls: MLS sensitivity label
 178  * @attr.mls.cat: MLS category bitmap
 179  * @attr.mls.lvl: MLS sensitivity level
 180  * @attr.secid: LSM specific secid token
 181  *
 182  * Description:
 183  * This structure is used to pass security attributes between NetLabel and the
 184  * LSM modules.  The flags field is used to specify which fields within the
 185  * struct are valid and valid values can be created by bitwise OR'ing the
 186  * NETLBL_SECATTR_* defines.  The domain field is typically set by the LSM to
 187  * specify domain specific configuration settings and is not usually used by
 188  * NetLabel itself when returning security attributes to the LSM.
 189  *
 190  */
 191 struct netlbl_lsm_secattr {
 192         u32 flags;
 193         /* bitmap values for 'flags' */
 194 #define NETLBL_SECATTR_NONE             0x00000000
 195 #define NETLBL_SECATTR_DOMAIN           0x00000001
 196 #define NETLBL_SECATTR_DOMAIN_CPY       (NETLBL_SECATTR_DOMAIN | \
 197                                          NETLBL_SECATTR_FREE_DOMAIN)
 198 #define NETLBL_SECATTR_CACHE            0x00000002
 199 #define NETLBL_SECATTR_MLS_LVL          0x00000004
 200 #define NETLBL_SECATTR_MLS_CAT          0x00000008
 201 #define NETLBL_SECATTR_SECID            0x00000010
 202         /* bitmap meta-values for 'flags' */
 203 #define NETLBL_SECATTR_FREE_DOMAIN      0x01000000
 204 #define NETLBL_SECATTR_CACHEABLE        (NETLBL_SECATTR_MLS_LVL | \
 205                                          NETLBL_SECATTR_MLS_CAT | \
 206                                          NETLBL_SECATTR_SECID)
 207         u32 type;
 208         char *domain;
 209         struct netlbl_lsm_cache *cache;
 210         struct {
 211                 struct {
 212                         struct netlbl_lsm_catmap *cat;
 213                         u32 lvl;
 214                 } mls;
 215                 u32 secid;
 216         } attr;
 217 };
 218
 219 /*
 220  * LSM security attribute operations (inline)
 221  */
 222
 223 /**
 224  * netlbl_secattr_cache_alloc - Allocate and initialize a secattr cache
 225  * @flags: the memory allocation flags
 226  *
 227  * Description:
 228  * Allocate and initialize a netlbl_lsm_cache structure.  Returns a pointer
 229  * on success, NULL on failure.
 230  *
 231  */
 232 static inline struct netlbl_lsm_cache *netlbl_secattr_cache_alloc(gfp_t flags)
 233 {
 234         struct netlbl_lsm_cache *cache;
 235
 236         cache = kzalloc(sizeof(*cache), flags);
 237         if (cache)
 238                 atomic_set(&cache->refcount, 1);
 239         return cache;
 240 }
 241
 242 /**
 243  * netlbl_secattr_cache_free - Frees a netlbl_lsm_cache struct
 244  * @cache: the struct to free
 245  *
 246  * Description:
 247  * Frees @secattr including all of the internal buffers.
 248  *
 249  */
 250 static inline void netlbl_secattr_cache_free(struct netlbl_lsm_cache *cache)
 251 {
 252         if (!atomic_dec_and_test(&cache->refcount))
 253                 return;
 254
 255         if (cache->free)
 256                 cache->free(cache->data);
 257         kfree(cache);
 258 }
 259
 260 /**
 261  * netlbl_catmap_alloc - Allocate a LSM secattr catmap
 262  * @flags: memory allocation flags
 263  *
 264  * Description:
 265  * Allocate memory for a LSM secattr catmap, returns a pointer on success, NULL
 266  * on failure.
 267  *
 268  */
 269 static inline struct netlbl_lsm_catmap *netlbl_catmap_alloc(gfp_t flags)
 270 {
 271         return kzalloc(sizeof(struct netlbl_lsm_catmap), flags);
 272 }
 273
 274 /**
 275  * netlbl_catmap_free - Free a LSM secattr catmap
 276  * @catmap: the category bitmap
 277  *
 278  * Description:
 279  * Free a LSM secattr catmap.
 280  *
 281  */
 282 static inline void netlbl_catmap_free(struct netlbl_lsm_catmap *catmap)
 283 {
 284         struct netlbl_lsm_catmap *iter;
 285
 286         while (catmap) {
 287                 iter = catmap;
 288                 catmap = catmap->next;
 289                 kfree(iter);
 290         }
 291 }
 292
 293 /**
 294  * netlbl_secattr_init - Initialize a netlbl_lsm_secattr struct
 295  * @secattr: the struct to initialize
 296  *
 297  * Description:
 298  * Initialize an already allocated netlbl_lsm_secattr struct.
 299  *
 300  */
 301 static inline void netlbl_secattr_init(struct netlbl_lsm_secattr *secattr)
 302 {
 303         memset(secattr, 0, sizeof(*secattr));
 304 }
 305
 306 /**
 307  * netlbl_secattr_destroy - Clears a netlbl_lsm_secattr struct
 308  * @secattr: the struct to clear
 309  *
 310  * Description:
 311  * Destroys the @secattr struct, including freeing all of the internal buffers.
 312  * The struct must be reset with a call to netlbl_secattr_init() before reuse.
 313  *
 314  */
 315 static inline void netlbl_secattr_destroy(struct netlbl_lsm_secattr *secattr)
 316 {
 317         if (secattr->flags & NETLBL_SECATTR_FREE_DOMAIN)
 318                 kfree(secattr->domain);
 319         if (secattr->flags & NETLBL_SECATTR_CACHE)
 320                 netlbl_secattr_cache_free(secattr->cache);
 321         if (secattr->flags & NETLBL_SECATTR_MLS_CAT)
 322                 netlbl_catmap_free(secattr->attr.mls.cat);
 323 }
 324
 325 /**
 326  * netlbl_secattr_alloc - Allocate and initialize a netlbl_lsm_secattr struct
 327  * @flags: the memory allocation flags
 328  *
 329  * Description:
 330  * Allocate and initialize a netlbl_lsm_secattr struct.  Returns a valid
 331  * pointer on success, or NULL on failure.
 332  *
 333  */
 334 static inline struct netlbl_lsm_secattr *netlbl_secattr_alloc(gfp_t flags)
 335 {
 336         return kzalloc(sizeof(struct netlbl_lsm_secattr), flags);
 337 }
 338
 339 /**
 340  * netlbl_secattr_free - Frees a netlbl_lsm_secattr struct
 341  * @secattr: the struct to free
 342  *
 343  * Description:
 344  * Frees @secattr including all of the internal buffers.
 345  *
 346  */
 347 static inline void netlbl_secattr_free(struct netlbl_lsm_secattr *secattr)
 348 {
 349         netlbl_secattr_destroy(secattr);
 350         kfree(secattr);
 351 }
 352
 353 #ifdef CONFIG_NETLABEL
 354 /*
 355  * LSM configuration operations
 356  */
 357 int netlbl_cfg_map_del(const char *domain,
 358                        u16 family,
 359                        const void *addr,
 360                        const void *mask,
 361                        struct netlbl_audit *audit_info);
 362 int netlbl_cfg_unlbl_map_add(const char *domain,
 363                              u16 family,
 364                              const void *addr,
 365                              const void *mask,
 366                              struct netlbl_audit *audit_info);
 367 int netlbl_cfg_unlbl_static_add(struct net *net,
 368                                 const char *dev_name,
 369                                 const void *addr,
 370                                 const void *mask,
 371                                 u16 family,
 372                                 u32 secid,
 373                                 struct netlbl_audit *audit_info);
 374 int netlbl_cfg_unlbl_static_del(struct net *net,
 375                                 const char *dev_name,
 376                                 const void *addr,
 377                                 const void *mask,
 378                                 u16 family,
 379                                 struct netlbl_audit *audit_info);
 380 int netlbl_cfg_cipsov4_add(struct cipso_v4_doi *doi_def,
 381                            struct netlbl_audit *audit_info);
 382 void netlbl_cfg_cipsov4_del(u32 doi, struct netlbl_audit *audit_info);
 383 int netlbl_cfg_cipsov4_map_add(u32 doi,
 384                                const char *domain,
 385                                const struct in_addr *addr,
 386                                const struct in_addr *mask,
 387                                struct netlbl_audit *audit_info);
 388 /*
 389  * LSM security attribute operations
 390  */
 391 int netlbl_catmap_walk(struct netlbl_lsm_catmap *catmap, u32 offset);
 392 int netlbl_catmap_walkrng(struct netlbl_lsm_catmap *catmap, u32 offset);
 393 int netlbl_catmap_getlong(struct netlbl_lsm_catmap *catmap,
 394                           u32 *offset,
 395                           unsigned long *bitmap);
 396 int netlbl_catmap_setbit(struct netlbl_lsm_catmap **catmap,
 397                          u32 bit,
 398                          gfp_t flags);
 399 int netlbl_catmap_setrng(struct netlbl_lsm_catmap **catmap,
 400                          u32 start,
 401                          u32 end,
 402                          gfp_t flags);
 403 int netlbl_catmap_setlong(struct netlbl_lsm_catmap **catmap,
 404                           u32 offset,
 405                           unsigned long bitmap,
 406                           gfp_t flags);
 407
 408 /*
 409  * LSM protocol operations (NetLabel LSM/kernel API)
 410  */
 411 int netlbl_enabled(void);
 412 int netlbl_sock_setattr(struct sock *sk,
 413                         u16 family,
 414                         const struct netlbl_lsm_secattr *secattr);
 415 void netlbl_sock_delattr(struct sock *sk);
 416 int netlbl_sock_getattr(struct sock *sk,
 417                         struct netlbl_lsm_secattr *secattr);
 418 int netlbl_conn_setattr(struct sock *sk,
 419                         struct sockaddr *addr,
 420                         const struct netlbl_lsm_secattr *secattr);
 421 int netlbl_req_setattr(struct request_sock *req,
 422                        const struct netlbl_lsm_secattr *secattr);
 423 void netlbl_req_delattr(struct request_sock *req);
 424 int netlbl_skbuff_setattr(struct sk_buff *skb,
 425                           u16 family,
 426                           const struct netlbl_lsm_secattr *secattr);
 427 int netlbl_skbuff_getattr(const struct sk_buff *skb,
 428                           u16 family,
 429                           struct netlbl_lsm_secattr *secattr);
 430 void netlbl_skbuff_err(struct sk_buff *skb, int error, int gateway);
 431
 432 /*
 433  * LSM label mapping cache operations
 434  */
 435 void netlbl_cache_invalidate(void);
 436 int netlbl_cache_add(const struct sk_buff *skb,
 437                      const struct netlbl_lsm_secattr *secattr);
 438
 439 /*
 440  * Protocol engine operations
 441  */
 442 struct audit_buffer *netlbl_audit_start(int type,
 443                                         struct netlbl_audit *audit_info);
 444 #else
 445 static inline int netlbl_cfg_map_del(const char *domain,
 446                                      u16 family,
 447                                      const void *addr,
 448                                      const void *mask,
 449                                      struct netlbl_audit *audit_info)
 450 {
 451         return -ENOSYS;
 452 }
 453 static inline int netlbl_cfg_unlbl_map_add(const char *domain,
 454                                            u16 family,
 455                                            void *addr,
 456                                            void *mask,
 457                                            struct netlbl_audit *audit_info)
 458 {
 459         return -ENOSYS;
 460 }
 461 static inline int netlbl_cfg_unlbl_static_add(struct net *net,
 462                                               const char *dev_name,
 463                                               const void *addr,
 464                                               const void *mask,
 465                                               u16 family,
 466                                               u32 secid,
 467                                               struct netlbl_audit *audit_info)
 468 {
 469         return -ENOSYS;
 470 }
 471 static inline int netlbl_cfg_unlbl_static_del(struct net *net,
 472                                               const char *dev_name,
 473                                               const void *addr,
 474                                               const void *mask,
 475                                               u16 family,
 476                                               struct netlbl_audit *audit_info)
 477 {
 478         return -ENOSYS;
 479 }
 480 static inline int netlbl_cfg_cipsov4_add(struct cipso_v4_doi *doi_def,
 481                                          struct netlbl_audit *audit_info)
 482 {
 483         return -ENOSYS;
 484 }
 485 static inline void netlbl_cfg_cipsov4_del(u32 doi,
 486                                           struct netlbl_audit *audit_info)
 487 {
 488         return;
 489 }
 490 static inline int netlbl_cfg_cipsov4_map_add(u32 doi,
 491                                              const char *domain,
 492                                              const struct in_addr *addr,
 493                                              const struct in_addr *mask,
 494                                              struct netlbl_audit *audit_info)
 495 {
 496         return -ENOSYS;
 497 }
 498 static inline int netlbl_catmap_walk(struct netlbl_lsm_catmap *catmap,
 499                                      u32 offset)
 500 {
 501         return -ENOENT;
 502 }
 503 static inline int netlbl_catmap_walkrng(struct netlbl_lsm_catmap *catmap,
 504                                         u32 offset)
 505 {
 506         return -ENOENT;
 507 }
 508 static inline int netlbl_catmap_getlong(struct netlbl_lsm_catmap *catmap,
 509                                         u32 *offset,
 510                                         unsigned long *bitmap)
 511 {
 512         return 0;
 513 }
 514 static inline int netlbl_catmap_setbit(struct netlbl_lsm_catmap **catmap,
 515                                        u32 bit,
 516                                        gfp_t flags)
 517 {
 518         return 0;
 519 }
 520 static inline int netlbl_catmap_setrng(struct netlbl_lsm_catmap **catmap,
 521                                        u32 start,
 522                                        u32 end,
 523                                        gfp_t flags)
 524 {
 525         return 0;
 526 }
 527 static int netlbl_catmap_setlong(struct netlbl_lsm_catmap **catmap,
 528                                  u32 offset,
 529                                  unsigned long bitmap,
 530                                  gfp_t flags)
 531 {
 532         return 0;
 533 }
 534 static inline int netlbl_enabled(void)
 535 {
 536         return 0;
 537 }
 538 static inline int netlbl_sock_setattr(struct sock *sk,
 539                                       u16 family,
 540                                       const struct netlbl_lsm_secattr *secattr)
 541 {
 542         return -ENOSYS;
 543 }
 544 static inline void netlbl_sock_delattr(struct sock *sk)
 545 {
 546 }
 547 static inline int netlbl_sock_getattr(struct sock *sk,
 548                                       struct netlbl_lsm_secattr *secattr)
 549 {
 550         return -ENOSYS;
 551 }
 552 static inline int netlbl_conn_setattr(struct sock *sk,
 553                                       struct sockaddr *addr,
 554                                       const struct netlbl_lsm_secattr *secattr)
 555 {
 556         return -ENOSYS;
 557 }
 558 static inline int netlbl_req_setattr(struct request_sock *req,
 559                                      const struct netlbl_lsm_secattr *secattr)
 560 {
 561         return -ENOSYS;
 562 }
 563 static inline void netlbl_req_delattr(struct request_sock *req)
 564 {
 565         return;
 566 }
 567 static inline int netlbl_skbuff_setattr(struct sk_buff *skb,
 568                                       u16 family,
 569                                       const struct netlbl_lsm_secattr *secattr)
 570 {
 571         return -ENOSYS;
 572 }
 573 static inline int netlbl_skbuff_getattr(const struct sk_buff *skb,
 574                                         u16 family,
 575                                         struct netlbl_lsm_secattr *secattr)
 576 {
 577         return -ENOSYS;
 578 }
 579 static inline void netlbl_skbuff_err(struct sk_buff *skb,
 580                                      int error,
 581                                      int gateway)
 582 {
 583         return;
 584 }
 585 static inline void netlbl_cache_invalidate(void)
 586 {
 587         return;
 588 }
 589 static inline int netlbl_cache_add(const struct sk_buff *skb,
 590                                    const struct netlbl_lsm_secattr *secattr)
 591 {
 592         return 0;
 593 }
 594 static inline struct audit_buffer *netlbl_audit_start(int type,
 595                                                 struct netlbl_audit *audit_info)
 596 {
 597         return NULL;
 598 }
 599 #endif /* CONFIG_NETLABEL */
 600
 601 #endif /* _NETLABEL_H */