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 <net/netlink.h>
  37 #include <asm/atomic.h>
  38
  39 struct cipso_v4_doi;
  40
  41 /*
  42  * NetLabel - A management interface for maintaining network packet label
  43  *            mapping tables for explicit packet labling protocols.
  44  *
  45  * Network protocols such as CIPSO and RIPSO require a label translation layer
  46  * to convert the label on the packet into something meaningful on the host
  47  * machine.  In the current Linux implementation these mapping tables live
  48  * inside the kernel; NetLabel provides a mechanism for user space applications
  49  * to manage these mapping tables.
  50  *
  51  * NetLabel makes use of the Generic NETLINK mechanism as a transport layer to
  52  * send messages between kernel and user space.  The general format of a
  53  * NetLabel message is shown below:
  54  *
  55  *  +-----------------+-------------------+--------- --- -- -
  56  *  | struct nlmsghdr | struct genlmsghdr | payload
  57  *  +-----------------+-------------------+--------- --- -- -
  58  *
  59  * The 'nlmsghdr' and 'genlmsghdr' structs should be dealt with like normal.
  60  * The payload is dependent on the subsystem specified in the
  61  * 'nlmsghdr->nlmsg_type' and should be defined below, supporting functions
  62  * should be defined in the corresponding net/netlabel/netlabel_<subsys>.h|c
  63  * file.  All of the fields in the NetLabel payload are NETLINK attributes, see
  64  * the include/net/netlink.h file for more information on NETLINK attributes.
  65  *
  66  */
  67
  68 /*
  69  * NetLabel NETLINK protocol
  70  */
  71
  72 /* NetLabel NETLINK protocol version
  73  *  1: initial version
  74  *  2: added static labels for unlabeled connections
  75  *  3: network selectors added to the NetLabel/LSM domain mapping
  76  */
  77 #define NETLBL_PROTO_VERSION            3
  78
  79 /* NetLabel NETLINK types/families */
  80 #define NETLBL_NLTYPE_NONE              0
  81 #define NETLBL_NLTYPE_MGMT              1
  82 #define NETLBL_NLTYPE_MGMT_NAME         "NLBL_MGMT"
  83 #define NETLBL_NLTYPE_RIPSO             2
  84 #define NETLBL_NLTYPE_RIPSO_NAME        "NLBL_RIPSO"
  85 #define NETLBL_NLTYPE_CIPSOV4           3
  86 #define NETLBL_NLTYPE_CIPSOV4_NAME      "NLBL_CIPSOv4"
  87 #define NETLBL_NLTYPE_CIPSOV6           4
  88 #define NETLBL_NLTYPE_CIPSOV6_NAME      "NLBL_CIPSOv6"
  89 #define NETLBL_NLTYPE_UNLABELED         5
  90 #define NETLBL_NLTYPE_UNLABELED_NAME    "NLBL_UNLBL"
  91 #define NETLBL_NLTYPE_ADDRSELECT        6
  92 #define NETLBL_NLTYPE_ADDRSELECT_NAME   "NLBL_ADRSEL"
  93
  94 /*
  95  * NetLabel - Kernel API for accessing the network packet label mappings.
  96  *
  97  * The following functions are provided for use by other kernel modules,
  98  * specifically kernel LSM modules, to provide a consistent, transparent API
  99  * for dealing with explicit packet labeling protocols such as CIPSO and
 100  * RIPSO.  The functions defined here are implemented in the
 101  * net/netlabel/netlabel_kapi.c file.
 102  *
 103  */
 104
 105 /* NetLabel audit information */
 106 struct netlbl_audit {
 107         u32 secid;
 108         uid_t loginuid;
 109         u32 sessionid;
 110 };
 111
 112 /*
 113  * LSM security attributes
 114  */
 115
 116 /**
 117  * struct netlbl_lsm_cache - NetLabel LSM security attribute cache
 118  * @refcount: atomic reference counter
 119  * @free: LSM supplied function to free the cache data
 120  * @data: LSM supplied cache data
 121  *
 122  * Description:
 123  * This structure is provided for LSMs which wish to make use of the NetLabel
 124  * caching mechanism to store LSM specific data/attributes in the NetLabel
 125  * cache.  If the LSM has to perform a lot of translation from the NetLabel
 126  * security attributes into it's own internal representation then the cache
 127  * mechanism can provide a way to eliminate some or all of that translation
 128  * overhead on a cache hit.
 129  *
 130  */
 131 struct netlbl_lsm_cache {
 132         atomic_t refcount;
 133         void (*free) (const void *data);
 134         void *data;
 135 };
 136
 137 /**
 138  * struct netlbl_lsm_secattr_catmap - NetLabel LSM secattr category bitmap
 139  * @startbit: the value of the lowest order bit in the bitmap
 140  * @bitmap: the category bitmap
 141  * @next: pointer to the next bitmap "node" or NULL
 142  *
 143  * Description:
 144  * This structure is used to represent category bitmaps.  Due to the large
 145  * number of categories supported by most labeling protocols it is not
 146  * practical to transfer a full bitmap internally so NetLabel adopts a sparse
 147  * bitmap structure modeled after SELinux's ebitmap structure.
 148  * The catmap bitmap field MUST be a power of two in length and large
 149  * enough to hold at least 240 bits.  Special care (i.e. check the code!)
 150  * should be used when changing these values as the LSM implementation
 151  * probably has functions which rely on the sizes of these types to speed
 152  * processing.
 153  *
 154  */
 155 #define NETLBL_CATMAP_MAPTYPE           u64
 156 #define NETLBL_CATMAP_MAPCNT            4
 157 #define NETLBL_CATMAP_MAPSIZE           (sizeof(NETLBL_CATMAP_MAPTYPE) * 8)
 158 #define NETLBL_CATMAP_SIZE              (NETLBL_CATMAP_MAPSIZE * \
 159                                          NETLBL_CATMAP_MAPCNT)
 160 #define NETLBL_CATMAP_BIT               (NETLBL_CATMAP_MAPTYPE)0x01
 161 struct netlbl_lsm_secattr_catmap {
 162         u32 startbit;
 163         NETLBL_CATMAP_MAPTYPE bitmap[NETLBL_CATMAP_MAPCNT];
 164         struct netlbl_lsm_secattr_catmap *next;
 165 };
 166
 167 /**
 168  * struct netlbl_lsm_secattr - NetLabel LSM security attributes
 169  * @flags: indicate structure attributes, see NETLBL_SECATTR_*
 170  * @type: indicate the NLTYPE of the attributes
 171  * @domain: the NetLabel LSM domain
 172  * @cache: NetLabel LSM specific cache
 173  * @attr.mls: MLS sensitivity label
 174  * @attr.mls.cat: MLS category bitmap
 175  * @attr.mls.lvl: MLS sensitivity level
 176  * @attr.secid: LSM specific secid token
 177  *
 178  * Description:
 179  * This structure is used to pass security attributes between NetLabel and the
 180  * LSM modules.  The flags field is used to specify which fields within the
 181  * struct are valid and valid values can be created by bitwise OR'ing the
 182  * NETLBL_SECATTR_* defines.  The domain field is typically set by the LSM to
 183  * specify domain specific configuration settings and is not usually used by
 184  * NetLabel itself when returning security attributes to the LSM.
 185  *
 186  */
 187 struct netlbl_lsm_secattr {
 188         u32 flags;
 189         /* bitmap values for 'flags' */
 190 #define NETLBL_SECATTR_NONE             0x00000000
 191 #define NETLBL_SECATTR_DOMAIN           0x00000001
 192 #define NETLBL_SECATTR_DOMAIN_CPY       (NETLBL_SECATTR_DOMAIN | \
 193                                          NETLBL_SECATTR_FREE_DOMAIN)
 194 #define NETLBL_SECATTR_CACHE            0x00000002
 195 #define NETLBL_SECATTR_MLS_LVL          0x00000004
 196 #define NETLBL_SECATTR_MLS_CAT          0x00000008
 197 #define NETLBL_SECATTR_SECID            0x00000010
 198         /* bitmap meta-values for 'flags' */
 199 #define NETLBL_SECATTR_FREE_DOMAIN      0x01000000
 200 #define NETLBL_SECATTR_CACHEABLE        (NETLBL_SECATTR_MLS_LVL | \
 201                                          NETLBL_SECATTR_MLS_CAT | \
 202                                          NETLBL_SECATTR_SECID)
 203         u32 type;
 204         char *domain;
 205         struct netlbl_lsm_cache *cache;
 206         union {
 207                 struct {
 208                         struct netlbl_lsm_secattr_catmap *cat;
 209                         u32 lvl;
 210                 } mls;
 211                 u32 secid;
 212         } attr;
 213 };
 214
 215 /*
 216  * LSM security attribute operations (inline)
 217  */
 218
 219 /**
 220  * netlbl_secattr_cache_alloc - Allocate and initialize a secattr cache
 221  * @flags: the memory allocation flags
 222  *
 223  * Description:
 224  * Allocate and initialize a netlbl_lsm_cache structure.  Returns a pointer
 225  * on success, NULL on failure.
 226  *
 227  */
 228 static inline struct netlbl_lsm_cache *netlbl_secattr_cache_alloc(gfp_t flags)
 229 {
 230         struct netlbl_lsm_cache *cache;
 231
 232         cache = kzalloc(sizeof(*cache), flags);
 233         if (cache)
 234                 atomic_set(&cache->refcount, 1);
 235         return cache;
 236 }
 237
 238 /**
 239  * netlbl_secattr_cache_free - Frees a netlbl_lsm_cache struct
 240  * @cache: the struct to free
 241  *
 242  * Description:
 243  * Frees @secattr including all of the internal buffers.
 244  *
 245  */
 246 static inline void netlbl_secattr_cache_free(struct netlbl_lsm_cache *cache)
 247 {
 248         if (!atomic_dec_and_test(&cache->refcount))
 249                 return;
 250
 251         if (cache->free)
 252                 cache->free(cache->data);
 253         kfree(cache);
 254 }
 255
 256 /**
 257  * netlbl_secattr_catmap_alloc - Allocate a LSM secattr catmap
 258  * @flags: memory allocation flags
 259  *
 260  * Description:
 261  * Allocate memory for a LSM secattr catmap, returns a pointer on success, NULL
 262  * on failure.
 263  *
 264  */
 265 static inline struct netlbl_lsm_secattr_catmap *netlbl_secattr_catmap_alloc(
 266                                                                    gfp_t flags)
 267 {
 268         return kzalloc(sizeof(struct netlbl_lsm_secattr_catmap), flags);
 269 }
 270
 271 /**
 272  * netlbl_secattr_catmap_free - Free a LSM secattr catmap
 273  * @catmap: the category bitmap
 274  *
 275  * Description:
 276  * Free a LSM secattr catmap.
 277  *
 278  */
 279 static inline void netlbl_secattr_catmap_free(
 280                                       struct netlbl_lsm_secattr_catmap *catmap)
 281 {
 282         struct netlbl_lsm_secattr_catmap *iter;
 283
 284         do {
 285                 iter = catmap;
 286                 catmap = catmap->next;
 287                 kfree(iter);
 288         } while (catmap);
 289 }
 290
 291 /**
 292  * netlbl_secattr_init - Initialize a netlbl_lsm_secattr struct
 293  * @secattr: the struct to initialize
 294  *
 295  * Description:
 296  * Initialize an already allocated netlbl_lsm_secattr struct.
 297  *
 298  */
 299 static inline void netlbl_secattr_init(struct netlbl_lsm_secattr *secattr)
 300 {
 301         memset(secattr, 0, sizeof(*secattr));
 302 }
 303
 304 /**
 305  * netlbl_secattr_destroy - Clears a netlbl_lsm_secattr struct
 306  * @secattr: the struct to clear
 307  *
 308  * Description:
 309  * Destroys the @secattr struct, including freeing all of the internal buffers.
 310  * The struct must be reset with a call to netlbl_secattr_init() before reuse.
 311  *
 312  */
 313 static inline void netlbl_secattr_destroy(struct netlbl_lsm_secattr *secattr)
 314 {
 315         if (secattr->flags & NETLBL_SECATTR_FREE_DOMAIN)
 316                 kfree(secattr->domain);
 317         if (secattr->flags & NETLBL_SECATTR_CACHE)
 318                 netlbl_secattr_cache_free(secattr->cache);
 319         if (secattr->flags & NETLBL_SECATTR_MLS_CAT)
 320                 netlbl_secattr_catmap_free(secattr->attr.mls.cat);
 321 }
 322
 323 /**
 324  * netlbl_secattr_alloc - Allocate and initialize a netlbl_lsm_secattr struct
 325  * @flags: the memory allocation flags
 326  *
 327  * Description:
 328  * Allocate and initialize a netlbl_lsm_secattr struct.  Returns a valid
 329  * pointer on success, or NULL on failure.
 330  *
 331  */
 332 static inline struct netlbl_lsm_secattr *netlbl_secattr_alloc(gfp_t flags)
 333 {
 334         return kzalloc(sizeof(struct netlbl_lsm_secattr), flags);
 335 }
 336
 337 /**
 338  * netlbl_secattr_free - Frees a netlbl_lsm_secattr struct
 339  * @secattr: the struct to free
 340  *
 341  * Description:
 342  * Frees @secattr including all of the internal buffers.
 343  *
 344  */
 345 static inline void netlbl_secattr_free(struct netlbl_lsm_secattr *secattr)
 346 {
 347         netlbl_secattr_destroy(secattr);
 348         kfree(secattr);
 349 }
 350
 351 #ifdef CONFIG_NETLABEL
 352 /*
 353  * LSM configuration operations
 354  */
 355 int netlbl_cfg_map_del(const char *domain, struct netlbl_audit *audit_info);
 356 int netlbl_cfg_unlbl_add_map(const char *domain,
 357                              struct netlbl_audit *audit_info);
 358 int netlbl_cfg_cipsov4_add_map(struct cipso_v4_doi *doi_def,
 359                                const char *domain,
 360                                struct netlbl_audit *audit_info);
 361
 362 /*
 363  * LSM security attribute operations
 364  */
 365 int netlbl_secattr_catmap_walk(struct netlbl_lsm_secattr_catmap *catmap,
 366                                u32 offset);
 367 int netlbl_secattr_catmap_walk_rng(struct netlbl_lsm_secattr_catmap *catmap,
 368                                    u32 offset);
 369 int netlbl_secattr_catmap_setbit(struct netlbl_lsm_secattr_catmap *catmap,
 370                                  u32 bit,
 371                                  gfp_t flags);
 372 int netlbl_secattr_catmap_setrng(struct netlbl_lsm_secattr_catmap *catmap,
 373                                  u32 start,
 374                                  u32 end,
 375                                  gfp_t flags);
 376
 377 /*
 378  * LSM protocol operations (NetLabel LSM/kernel API)
 379  */
 380 int netlbl_enabled(void);
 381 int netlbl_sock_setattr(struct sock *sk,
 382                         const struct netlbl_lsm_secattr *secattr);
 383 int netlbl_sock_getattr(struct sock *sk,
 384                         struct netlbl_lsm_secattr *secattr);
 385 int netlbl_skbuff_setattr(struct sk_buff *skb,
 386                           u16 family,
 387                           const struct netlbl_lsm_secattr *secattr);
 388 int netlbl_skbuff_getattr(const struct sk_buff *skb,
 389                           u16 family,
 390                           struct netlbl_lsm_secattr *secattr);
 391 void netlbl_skbuff_err(struct sk_buff *skb, int error, int gateway);
 392
 393 /*
 394  * LSM label mapping cache operations
 395  */
 396 void netlbl_cache_invalidate(void);
 397 int netlbl_cache_add(const struct sk_buff *skb,
 398                      const struct netlbl_lsm_secattr *secattr);
 399 #else
 400 static inline int netlbl_cfg_map_del(const char *domain,
 401                                      struct netlbl_audit *audit_info)
 402 {
 403         return -ENOSYS;
 404 }
 405 static inline int netlbl_cfg_unlbl_add_map(const char *domain,
 406                                            struct netlbl_audit *audit_info)
 407 {
 408         return -ENOSYS;
 409 }
 410 static inline int netlbl_cfg_cipsov4_add_map(struct cipso_v4_doi *doi_def,
 411                                              const char *domain,
 412                                              struct netlbl_audit *audit_info)
 413 {
 414         return -ENOSYS;
 415 }
 416 static inline int netlbl_secattr_catmap_walk(
 417                                       struct netlbl_lsm_secattr_catmap *catmap,
 418                                       u32 offset)
 419 {
 420         return -ENOENT;
 421 }
 422 static inline int netlbl_secattr_catmap_walk_rng(
 423                                       struct netlbl_lsm_secattr_catmap *catmap,
 424                                       u32 offset)
 425 {
 426         return -ENOENT;
 427 }
 428 static inline int netlbl_secattr_catmap_setbit(
 429                                       struct netlbl_lsm_secattr_catmap *catmap,
 430                                       u32 bit,
 431                                       gfp_t flags)
 432 {
 433         return 0;
 434 }
 435 static inline int netlbl_secattr_catmap_setrng(
 436                                       struct netlbl_lsm_secattr_catmap *catmap,
 437                                       u32 start,
 438                                       u32 end,
 439                                       gfp_t flags)
 440 {
 441         return 0;
 442 }
 443 static inline int netlbl_enabled(void)
 444 {
 445         return 0;
 446 }
 447 static inline int netlbl_sock_setattr(struct sock *sk,
 448                                      const struct netlbl_lsm_secattr *secattr)
 449 {
 450         return -ENOSYS;
 451 }
 452 static inline int netlbl_sock_getattr(struct sock *sk,
 453                                       struct netlbl_lsm_secattr *secattr)
 454 {
 455         return -ENOSYS;
 456 }
 457 static inline int netlbl_skbuff_setattr(struct sk_buff *skb,
 458                                       u16 family,
 459                                       const struct netlbl_lsm_secattr *secattr)
 460 {
 461         return -ENOSYS;
 462 }
 463 static inline int netlbl_skbuff_getattr(const struct sk_buff *skb,
 464                                         u16 family,
 465                                         struct netlbl_lsm_secattr *secattr)
 466 {
 467         return -ENOSYS;
 468 }
 469 static inline void netlbl_skbuff_err(struct sk_buff *skb,
 470                                      int error,
 471                                      int gateway)
 472 {
 473         return;
 474 }
 475 static inline void netlbl_cache_invalidate(void)
 476 {
 477         return;
 478 }
 479 static inline int netlbl_cache_add(const struct sk_buff *skb,
 480                                    const struct netlbl_lsm_secattr *secattr)
 481 {
 482         return 0;
 483 }
 484 #endif /* CONFIG_NETLABEL */
 485
 486 #endif /* _NETLABEL_H */