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.moore@hp.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, write to the Free Software
  26  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
  27  *
  28  */
  29
  30 #ifndef _NETLABEL_H
  31 #define _NETLABEL_H
  32
  33 #include <linux/types.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 <asm/atomic.h>
  40
  41 struct cipso_v4_doi;
  42
  43 /*
  44  * NetLabel - A management interface for maintaining network packet label
  45  *            mapping tables for explicit packet labling protocols.
  46  *
  47  * Network protocols such as CIPSO and RIPSO require a label translation layer
  48  * to convert the label on the packet into something meaningful on the host
  49  * machine.  In the current Linux implementation these mapping tables live
  50  * inside the kernel; NetLabel provides a mechanism for user space applications
  51  * to manage these mapping tables.
  52  *
  53  * NetLabel makes use of the Generic NETLINK mechanism as a transport layer to
  54  * send messages between kernel and user space.  The general format of a
  55  * NetLabel message is shown below:
  56  *
  57  *  +-----------------+-------------------+--------- --- -- -
  58  *  | struct nlmsghdr | struct genlmsghdr | payload
  59  *  +-----------------+-------------------+--------- --- -- -
  60  *
  61  * The 'nlmsghdr' and 'genlmsghdr' structs should be dealt with like normal.
  62  * The payload is dependent on the subsystem specified in the
  63  * 'nlmsghdr->nlmsg_type' and should be defined below, supporting functions
  64  * should be defined in the corresponding net/netlabel/netlabel_<subsys>.h|c
  65  * file.  All of the fields in the NetLabel payload are NETLINK attributes, see
  66  * the include/net/netlink.h file for more information on NETLINK attributes.
  67  *
  68  */
  69
  70 /*
  71  * NetLabel NETLINK protocol
  72  */
  73
  74 /* NetLabel NETLINK protocol version
  75  *  1: initial version
  76  *  2: added static labels for unlabeled connections
  77  *  3: network selectors added to the NetLabel/LSM domain mapping and the
  78  *     CIPSO_V4_MAP_LOCAL CIPSO mapping was added
  79  */
  80 #define NETLBL_PROTO_VERSION            3
  81
  82 /* NetLabel NETLINK types/families */
  83 #define NETLBL_NLTYPE_NONE              0
  84 #define NETLBL_NLTYPE_MGMT              1
  85 #define NETLBL_NLTYPE_MGMT_NAME         "NLBL_MGMT"
  86 #define NETLBL_NLTYPE_RIPSO             2
  87 #define NETLBL_NLTYPE_RIPSO_NAME        "NLBL_RIPSO"
  88 #define NETLBL_NLTYPE_CIPSOV4           3
  89 #define NETLBL_NLTYPE_CIPSOV4_NAME      "NLBL_CIPSOv4"
  90 #define NETLBL_NLTYPE_CIPSOV6           4
  91 #define NETLBL_NLTYPE_CIPSOV6_NAME      "NLBL_CIPSOv6"
  92 #define NETLBL_NLTYPE_UNLABELED         5
  93 #define NETLBL_NLTYPE_UNLABELED_NAME    "NLBL_UNLBL"
  94 #define NETLBL_NLTYPE_ADDRSELECT        6
  95 #define NETLBL_NLTYPE_ADDRSELECT_NAME   "NLBL_ADRSEL"
  96
  97 /*
  98  * NetLabel - Kernel API for accessing the network packet label mappings.
  99  *
 100  * The following functions are provided for use by other kernel modules,
 101  * specifically kernel LSM modules, to provide a consistent, transparent API
 102  * for dealing with explicit packet labeling protocols such as CIPSO and
 103  * RIPSO.  The functions defined here are implemented in the
 104  * net/netlabel/netlabel_kapi.c file.
 105  *
 106  */
 107
 108 /* NetLabel audit information */
 109 struct netlbl_audit {
 110         u32 secid;
 111         uid_t loginuid;
 112         u32 sessionid;
 113 };
 114
 115 /*
 116  * LSM security attributes
 117  */
 118
 119 /**
 120  * struct netlbl_lsm_cache - NetLabel LSM security attribute cache
 121  * @refcount: atomic reference counter
 122  * @free: LSM supplied function to free the cache data
 123  * @data: LSM supplied cache data
 124  *
 125  * Description:
 126  * This structure is provided for LSMs which wish to make use of the NetLabel
 127  * caching mechanism to store LSM specific data/attributes in the NetLabel
 128  * cache.  If the LSM has to perform a lot of translation from the NetLabel
 129  * security attributes into it's own internal representation then the cache
 130  * mechanism can provide a way to eliminate some or all of that translation
 131  * overhead on a cache hit.
 132  *
 133  */
 134 struct netlbl_lsm_cache {
 135         atomic_t refcount;
 136         void (*free) (const void *data);
 137         void *data;
 138 };
 139
 140 /**
 141  * struct netlbl_lsm_secattr_catmap - NetLabel LSM secattr category bitmap
 142  * @startbit: the value of the lowest order bit in the bitmap
 143  * @bitmap: the category bitmap
 144  * @next: pointer to the next bitmap "node" or NULL
 145  *
 146  * Description:
 147  * This structure is used to represent category bitmaps.  Due to the large
 148  * number of categories supported by most labeling protocols it is not
 149  * practical to transfer a full bitmap internally so NetLabel adopts a sparse
 150  * bitmap structure modeled after SELinux's ebitmap structure.
 151  * The catmap bitmap field MUST be a power of two in length and large
 152  * enough to hold at least 240 bits.  Special care (i.e. check the code!)
 153  * should be used when changing these values as the LSM implementation
 154  * probably has functions which rely on the sizes of these types to speed
 155  * processing.
 156  *
 157  */
 158 #define NETLBL_CATMAP_MAPTYPE           u64
 159 #define NETLBL_CATMAP_MAPCNT            4
 160 #define NETLBL_CATMAP_MAPSIZE           (sizeof(NETLBL_CATMAP_MAPTYPE) * 8)
 161 #define NETLBL_CATMAP_SIZE              (NETLBL_CATMAP_MAPSIZE * \
 162                                          NETLBL_CATMAP_MAPCNT)
 163 #define NETLBL_CATMAP_BIT               (NETLBL_CATMAP_MAPTYPE)0x01
 164 struct netlbl_lsm_secattr_catmap {
 165         u32 startbit;
 166         NETLBL_CATMAP_MAPTYPE bitmap[NETLBL_CATMAP_MAPCNT];
 167         struct netlbl_lsm_secattr_catmap *next;
 168 };
 169
 170 /**
 171  * struct netlbl_lsm_secattr - NetLabel LSM security attributes
 172  * @flags: indicate structure attributes, see NETLBL_SECATTR_*
 173  * @type: indicate the NLTYPE of the attributes
 174  * @domain: the NetLabel LSM domain
 175  * @cache: NetLabel LSM specific cache
 176  * @attr.mls: MLS sensitivity label
 177  * @attr.mls.cat: MLS category bitmap
 178  * @attr.mls.lvl: MLS sensitivity level
 179  * @attr.secid: LSM specific secid token
 180  *
 181  * Description:
 182  * This structure is used to pass security attributes between NetLabel and the
 183  * LSM modules.  The flags field is used to specify which fields within the
 184  * struct are valid and valid values can be created by bitwise OR'ing the
 185  * NETLBL_SECATTR_* defines.  The domain field is typically set by the LSM to
 186  * specify domain specific configuration settings and is not usually used by
 187  * NetLabel itself when returning security attributes to the LSM.
 188  *
 189  */
 190 struct netlbl_lsm_secattr {
 191         u32 flags;
 192         /* bitmap values for 'flags' */
 193 #define NETLBL_SECATTR_NONE             0x00000000
 194 #define NETLBL_SECATTR_DOMAIN           0x00000001
 195 #define NETLBL_SECATTR_DOMAIN_CPY       (NETLBL_SECATTR_DOMAIN | \
 196                                          NETLBL_SECATTR_FREE_DOMAIN)
 197 #define NETLBL_SECATTR_CACHE            0x00000002
 198 #define NETLBL_SECATTR_MLS_LVL          0x00000004
 199 #define NETLBL_SECATTR_MLS_CAT          0x00000008
 200 #define NETLBL_SECATTR_SECID            0x00000010
 201         /* bitmap meta-values for 'flags' */
 202 #define NETLBL_SECATTR_FREE_DOMAIN      0x01000000
 203 #define NETLBL_SECATTR_CACHEABLE        (NETLBL_SECATTR_MLS_LVL | \
 204                                          NETLBL_SECATTR_MLS_CAT | \
 205                                          NETLBL_SECATTR_SECID)
 206         u32 type;
 207         char *domain;
 208         struct netlbl_lsm_cache *cache;
 209         struct {
 210                 struct {
 211                         struct netlbl_lsm_secattr_catmap *cat;
 212                         u32 lvl;
 213                 } mls;
 214                 u32 secid;
 215         } attr;
 216 };
 217
 218 /*
 219  * LSM security attribute operations (inline)
 220  */
 221
 222 /**
 223  * netlbl_secattr_cache_alloc - Allocate and initialize a secattr cache
 224  * @flags: the memory allocation flags
 225  *
 226  * Description:
 227  * Allocate and initialize a netlbl_lsm_cache structure.  Returns a pointer
 228  * on success, NULL on failure.
 229  *
 230  */
 231 static inline struct netlbl_lsm_cache *netlbl_secattr_cache_alloc(gfp_t flags)
 232 {
 233         struct netlbl_lsm_cache *cache;
 234
 235         cache = kzalloc(sizeof(*cache), flags);
 236         if (cache)
 237                 atomic_set(&cache->refcount, 1);
 238         return cache;
 239 }
 240
 241 /**
 242  * netlbl_secattr_cache_free - Frees a netlbl_lsm_cache struct
 243  * @cache: the struct to free
 244  *
 245  * Description:
 246  * Frees @secattr including all of the internal buffers.
 247  *
 248  */
 249 static inline void netlbl_secattr_cache_free(struct netlbl_lsm_cache *cache)
 250 {
 251         if (!atomic_dec_and_test(&cache->refcount))
 252                 return;
 253
 254         if (cache->free)
 255                 cache->free(cache->data);
 256         kfree(cache);
 257 }
 258
 259 /**
 260  * netlbl_secattr_catmap_alloc - Allocate a LSM secattr catmap
 261  * @flags: memory allocation flags
 262  *
 263  * Description:
 264  * Allocate memory for a LSM secattr catmap, returns a pointer on success, NULL
 265  * on failure.
 266  *
 267  */
 268 static inline struct netlbl_lsm_secattr_catmap *netlbl_secattr_catmap_alloc(
 269                                                                    gfp_t flags)
 270 {
 271         return kzalloc(sizeof(struct netlbl_lsm_secattr_catmap), flags);
 272 }
 273
 274 /**
 275  * netlbl_secattr_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_secattr_catmap_free(
 283                                       struct netlbl_lsm_secattr_catmap *catmap)
 284 {
 285         struct netlbl_lsm_secattr_catmap *iter;
 286
 287         do {
 288                 iter = catmap;
 289                 catmap = catmap->next;
 290                 kfree(iter);
 291         } while (catmap);
 292 }
 293
 294 /**
 295  * netlbl_secattr_init - Initialize a netlbl_lsm_secattr struct
 296  * @secattr: the struct to initialize
 297  *
 298  * Description:
 299  * Initialize an already allocated netlbl_lsm_secattr struct.
 300  *
 301  */
 302 static inline void netlbl_secattr_init(struct netlbl_lsm_secattr *secattr)
 303 {
 304         memset(secattr, 0, sizeof(*secattr));
 305 }
 306
 307 /**
 308  * netlbl_secattr_destroy - Clears a netlbl_lsm_secattr struct
 309  * @secattr: the struct to clear
 310  *
 311  * Description:
 312  * Destroys the @secattr struct, including freeing all of the internal buffers.
 313  * The struct must be reset with a call to netlbl_secattr_init() before reuse.
 314  *
 315  */
 316 static inline void netlbl_secattr_destroy(struct netlbl_lsm_secattr *secattr)
 317 {
 318         if (secattr->flags & NETLBL_SECATTR_FREE_DOMAIN)
 319                 kfree(secattr->domain);
 320         if (secattr->flags & NETLBL_SECATTR_CACHE)
 321                 netlbl_secattr_cache_free(secattr->cache);
 322         if (secattr->flags & NETLBL_SECATTR_MLS_CAT)
 323                 netlbl_secattr_catmap_free(secattr->attr.mls.cat);
 324 }
 325
 326 /**
 327  * netlbl_secattr_alloc - Allocate and initialize a netlbl_lsm_secattr struct
 328  * @flags: the memory allocation flags
 329  *
 330  * Description:
 331  * Allocate and initialize a netlbl_lsm_secattr struct.  Returns a valid
 332  * pointer on success, or NULL on failure.
 333  *
 334  */
 335 static inline struct netlbl_lsm_secattr *netlbl_secattr_alloc(gfp_t flags)
 336 {
 337         return kzalloc(sizeof(struct netlbl_lsm_secattr), flags);
 338 }
 339
 340 /**
 341  * netlbl_secattr_free - Frees a netlbl_lsm_secattr struct
 342  * @secattr: the struct to free
 343  *
 344  * Description:
 345  * Frees @secattr including all of the internal buffers.
 346  *
 347  */
 348 static inline void netlbl_secattr_free(struct netlbl_lsm_secattr *secattr)
 349 {
 350         netlbl_secattr_destroy(secattr);
 351         kfree(secattr);
 352 }
 353
 354 #ifdef CONFIG_NETLABEL
 355 /*
 356  * LSM configuration operations
 357  */
 358 int netlbl_cfg_map_del(const char *domain,
 359                        u16 family,
 360                        const void *addr,
 361                        const void *mask,
 362                        struct netlbl_audit *audit_info);
 363 int netlbl_cfg_unlbl_map_add(const char *domain,
 364                              u16 family,
 365                              const void *addr,
 366                              const void *mask,
 367                              struct netlbl_audit *audit_info);
 368 int netlbl_cfg_unlbl_static_add(struct net *net,
 369                                 const char *dev_name,
 370                                 const void *addr,
 371                                 const void *mask,
 372                                 u16 family,
 373                                 u32 secid,
 374                                 struct netlbl_audit *audit_info);
 375 int netlbl_cfg_unlbl_static_del(struct net *net,
 376                                 const char *dev_name,
 377                                 const void *addr,
 378                                 const void *mask,
 379                                 u16 family,
 380                                 struct netlbl_audit *audit_info);
 381 int netlbl_cfg_cipsov4_add(struct cipso_v4_doi *doi_def,
 382                            struct netlbl_audit *audit_info);
 383 void netlbl_cfg_cipsov4_del(u32 doi, struct netlbl_audit *audit_info);
 384 int netlbl_cfg_cipsov4_map_add(u32 doi,
 385                                const char *domain,
 386                                const struct in_addr *addr,
 387                                const struct in_addr *mask,
 388                                struct netlbl_audit *audit_info);
 389 /*
 390  * LSM security attribute operations
 391  */
 392 int netlbl_secattr_catmap_walk(struct netlbl_lsm_secattr_catmap *catmap,
 393                                u32 offset);
 394 int netlbl_secattr_catmap_walk_rng(struct netlbl_lsm_secattr_catmap *catmap,
 395                                    u32 offset);
 396 int netlbl_secattr_catmap_setbit(struct netlbl_lsm_secattr_catmap *catmap,
 397                                  u32 bit,
 398                                  gfp_t flags);
 399 int netlbl_secattr_catmap_setrng(struct netlbl_lsm_secattr_catmap *catmap,
 400                                  u32 start,
 401                                  u32 end,
 402                                  gfp_t flags);
 403
 404 /*
 405  * LSM protocol operations (NetLabel LSM/kernel API)
 406  */
 407 int netlbl_enabled(void);
 408 int netlbl_sock_setattr(struct sock *sk,
 409                         const struct netlbl_lsm_secattr *secattr);
 410 void netlbl_sock_delattr(struct sock *sk);
 411 int netlbl_sock_getattr(struct sock *sk,
 412                         struct netlbl_lsm_secattr *secattr);
 413 int netlbl_conn_setattr(struct sock *sk,
 414                         struct sockaddr *addr,
 415                         const struct netlbl_lsm_secattr *secattr);
 416 int netlbl_skbuff_setattr(struct sk_buff *skb,
 417                           u16 family,
 418                           const struct netlbl_lsm_secattr *secattr);
 419 int netlbl_skbuff_getattr(const struct sk_buff *skb,
 420                           u16 family,
 421                           struct netlbl_lsm_secattr *secattr);
 422 void netlbl_skbuff_err(struct sk_buff *skb, int error, int gateway);
 423
 424 /*
 425  * LSM label mapping cache operations
 426  */
 427 void netlbl_cache_invalidate(void);
 428 int netlbl_cache_add(const struct sk_buff *skb,
 429                      const struct netlbl_lsm_secattr *secattr);
 430
 431 /*
 432  * Protocol engine operations
 433  */
 434 struct audit_buffer *netlbl_audit_start(int type,
 435                                         struct netlbl_audit *audit_info);
 436 #else
 437 static inline int netlbl_cfg_map_del(const char *domain,
 438                                      u16 family,
 439                                      const void *addr,
 440                                      const void *mask,
 441                                      struct netlbl_audit *audit_info)
 442 {
 443         return -ENOSYS;
 444 }
 445 static inline int netlbl_cfg_unlbl_map_add(const char *domain,
 446                                            u16 family,
 447                                            void *addr,
 448                                            void *mask,
 449                                            struct netlbl_audit *audit_info)
 450 {
 451         return -ENOSYS;
 452 }
 453 static inline int netlbl_cfg_unlbl_static_add(struct net *net,
 454                                               const char *dev_name,
 455                                               const void *addr,
 456                                               const void *mask,
 457                                               u16 family,
 458                                               u32 secid,
 459                                               struct netlbl_audit *audit_info)
 460 {
 461         return -ENOSYS;
 462 }
 463 static inline int netlbl_cfg_unlbl_static_del(struct net *net,
 464                                               const char *dev_name,
 465                                               const void *addr,
 466                                               const void *mask,
 467                                               u16 family,
 468                                               struct netlbl_audit *audit_info)
 469 {
 470         return -ENOSYS;
 471 }
 472 static inline int netlbl_cfg_cipsov4_add(struct cipso_v4_doi *doi_def,
 473                                          struct netlbl_audit *audit_info)
 474 {
 475         return -ENOSYS;
 476 }
 477 static inline void netlbl_cfg_cipsov4_del(u32 doi,
 478                                           struct netlbl_audit *audit_info)
 479 {
 480         return;
 481 }
 482 static inline int netlbl_cfg_cipsov4_map_add(u32 doi,
 483                                              const char *domain,
 484                                              const struct in_addr *addr,
 485                                              const struct in_addr *mask,
 486                                              struct netlbl_audit *audit_info)
 487 {
 488         return -ENOSYS;
 489 }
 490 static inline int netlbl_secattr_catmap_walk(
 491                                       struct netlbl_lsm_secattr_catmap *catmap,
 492                                       u32 offset)
 493 {
 494         return -ENOENT;
 495 }
 496 static inline int netlbl_secattr_catmap_walk_rng(
 497                                       struct netlbl_lsm_secattr_catmap *catmap,
 498                                       u32 offset)
 499 {
 500         return -ENOENT;
 501 }
 502 static inline int netlbl_secattr_catmap_setbit(
 503                                       struct netlbl_lsm_secattr_catmap *catmap,
 504                                       u32 bit,
 505                                       gfp_t flags)
 506 {
 507         return 0;
 508 }
 509 static inline int netlbl_secattr_catmap_setrng(
 510                                       struct netlbl_lsm_secattr_catmap *catmap,
 511                                       u32 start,
 512                                       u32 end,
 513                                       gfp_t flags)
 514 {
 515         return 0;
 516 }
 517 static inline int netlbl_enabled(void)
 518 {
 519         return 0;
 520 }
 521 static inline int netlbl_sock_setattr(struct sock *sk,
 522                                      const struct netlbl_lsm_secattr *secattr)
 523 {
 524         return -ENOSYS;
 525 }
 526 static inline void netlbl_sock_delattr(struct sock *sk)
 527 {
 528 }
 529 static inline int netlbl_sock_getattr(struct sock *sk,
 530                                       struct netlbl_lsm_secattr *secattr)
 531 {
 532         return -ENOSYS;
 533 }
 534 static inline int netlbl_conn_setattr(struct sock *sk,
 535                                       struct sockaddr *addr,
 536                                       const struct netlbl_lsm_secattr *secattr)
 537 {
 538         return -ENOSYS;
 539 }
 540 static inline int netlbl_skbuff_setattr(struct sk_buff *skb,
 541                                       u16 family,
 542                                       const struct netlbl_lsm_secattr *secattr)
 543 {
 544         return -ENOSYS;
 545 }
 546 static inline int netlbl_skbuff_getattr(const struct sk_buff *skb,
 547                                         u16 family,
 548                                         struct netlbl_lsm_secattr *secattr)
 549 {
 550         return -ENOSYS;
 551 }
 552 static inline void netlbl_skbuff_err(struct sk_buff *skb,
 553                                      int error,
 554                                      int gateway)
 555 {
 556         return;
 557 }
 558 static inline void netlbl_cache_invalidate(void)
 559 {
 560         return;
 561 }
 562 static inline int netlbl_cache_add(const struct sk_buff *skb,
 563                                    const struct netlbl_lsm_secattr *secattr)
 564 {
 565         return 0;
 566 }
 567 static inline struct audit_buffer *netlbl_audit_start(int type,
 568                                                 struct netlbl_audit *audit_info)
 569 {
 570         return NULL;
 571 }
 572 #endif /* CONFIG_NETLABEL */
 573
 574 #endif /* _NETLABEL_H */