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
  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  */
  76 #define NETLBL_PROTO_VERSION            2
  77
  78 /* NetLabel NETLINK types/families */
  79 #define NETLBL_NLTYPE_NONE              0
  80 #define NETLBL_NLTYPE_MGMT              1
  81 #define NETLBL_NLTYPE_MGMT_NAME         "NLBL_MGMT"
  82 #define NETLBL_NLTYPE_RIPSO             2
  83 #define NETLBL_NLTYPE_RIPSO_NAME        "NLBL_RIPSO"
  84 #define NETLBL_NLTYPE_CIPSOV4           3
  85 #define NETLBL_NLTYPE_CIPSOV4_NAME      "NLBL_CIPSOv4"
  86 #define NETLBL_NLTYPE_CIPSOV6           4
  87 #define NETLBL_NLTYPE_CIPSOV6_NAME      "NLBL_CIPSOv6"
  88 #define NETLBL_NLTYPE_UNLABELED         5
  89 #define NETLBL_NLTYPE_UNLABELED_NAME    "NLBL_UNLBL"
  90
  91 /*
  92  * NetLabel - Kernel API for accessing the network packet label mappings.
  93  *
  94  * The following functions are provided for use by other kernel modules,
  95  * specifically kernel LSM modules, to provide a consistent, transparent API
  96  * for dealing with explicit packet labeling protocols such as CIPSO and
  97  * RIPSO.  The functions defined here are implemented in the
  98  * net/netlabel/netlabel_kapi.c file.
  99  *
 100  */
 101
 102 /* NetLabel audit information */
 103 struct netlbl_audit {
 104         u32 secid;
 105         uid_t loginuid;
 106         u32 sessionid;
 107 };
 108
 109 /*
 110  * LSM security attributes
 111  */
 112
 113 /**
 114  * struct netlbl_lsm_cache - NetLabel LSM security attribute cache
 115  * @refcount: atomic reference counter
 116  * @free: LSM supplied function to free the cache data
 117  * @data: LSM supplied cache data
 118  *
 119  * Description:
 120  * This structure is provided for LSMs which wish to make use of the NetLabel
 121  * caching mechanism to store LSM specific data/attributes in the NetLabel
 122  * cache.  If the LSM has to perform a lot of translation from the NetLabel
 123  * security attributes into it's own internal representation then the cache
 124  * mechanism can provide a way to eliminate some or all of that translation
 125  * overhead on a cache hit.
 126  *
 127  */
 128 struct netlbl_lsm_cache {
 129         atomic_t refcount;
 130         void (*free) (const void *data);
 131         void *data;
 132 };
 133
 134 /**
 135  * struct netlbl_lsm_secattr_catmap - NetLabel LSM secattr category bitmap
 136  * @startbit: the value of the lowest order bit in the bitmap
 137  * @bitmap: the category bitmap
 138  * @next: pointer to the next bitmap "node" or NULL
 139  *
 140  * Description:
 141  * This structure is used to represent category bitmaps.  Due to the large
 142  * number of categories supported by most labeling protocols it is not
 143  * practical to transfer a full bitmap internally so NetLabel adopts a sparse
 144  * bitmap structure modeled after SELinux's ebitmap structure.
 145  * The catmap bitmap field MUST be a power of two in length and large
 146  * enough to hold at least 240 bits.  Special care (i.e. check the code!)
 147  * should be used when changing these values as the LSM implementation
 148  * probably has functions which rely on the sizes of these types to speed
 149  * processing.
 150  *
 151  */
 152 #define NETLBL_CATMAP_MAPTYPE           u64
 153 #define NETLBL_CATMAP_MAPCNT            4
 154 #define NETLBL_CATMAP_MAPSIZE           (sizeof(NETLBL_CATMAP_MAPTYPE) * 8)
 155 #define NETLBL_CATMAP_SIZE              (NETLBL_CATMAP_MAPSIZE * \
 156                                          NETLBL_CATMAP_MAPCNT)
 157 #define NETLBL_CATMAP_BIT               (NETLBL_CATMAP_MAPTYPE)0x01
 158 struct netlbl_lsm_secattr_catmap {
 159         u32 startbit;
 160         NETLBL_CATMAP_MAPTYPE bitmap[NETLBL_CATMAP_MAPCNT];
 161         struct netlbl_lsm_secattr_catmap *next;
 162 };
 163
 164 /**
 165  * struct netlbl_lsm_secattr - NetLabel LSM security attributes
 166  * @flags: indicate structure attributes, see NETLBL_SECATTR_*
 167  * @type: indicate the NLTYPE of the attributes
 168  * @domain: the NetLabel LSM domain
 169  * @cache: NetLabel LSM specific cache
 170  * @attr.mls: MLS sensitivity label
 171  * @attr.mls.cat: MLS category bitmap
 172  * @attr.mls.lvl: MLS sensitivity level
 173  * @attr.secid: LSM specific secid token
 174  *
 175  * Description:
 176  * This structure is used to pass security attributes between NetLabel and the
 177  * LSM modules.  The flags field is used to specify which fields within the
 178  * struct are valid and valid values can be created by bitwise OR'ing the
 179  * NETLBL_SECATTR_* defines.  The domain field is typically set by the LSM to
 180  * specify domain specific configuration settings and is not usually used by
 181  * NetLabel itself when returning security attributes to the LSM.
 182  *
 183  */
 184 struct netlbl_lsm_secattr {
 185         u32 flags;
 186         /* bitmap values for 'flags' */
 187 #define NETLBL_SECATTR_NONE             0x00000000
 188 #define NETLBL_SECATTR_DOMAIN           0x00000001
 189 #define NETLBL_SECATTR_DOMAIN_CPY       (NETLBL_SECATTR_DOMAIN | \
 190                                          NETLBL_SECATTR_FREE_DOMAIN)
 191 #define NETLBL_SECATTR_CACHE            0x00000002
 192 #define NETLBL_SECATTR_MLS_LVL          0x00000004
 193 #define NETLBL_SECATTR_MLS_CAT          0x00000008
 194 #define NETLBL_SECATTR_SECID            0x00000010
 195         /* bitmap meta-values for 'flags' */
 196 #define NETLBL_SECATTR_FREE_DOMAIN      0x01000000
 197 #define NETLBL_SECATTR_CACHEABLE        (NETLBL_SECATTR_MLS_LVL | \
 198                                          NETLBL_SECATTR_MLS_CAT | \
 199                                          NETLBL_SECATTR_SECID)
 200         u32 type;
 201         char *domain;
 202         struct netlbl_lsm_cache *cache;
 203         union {
 204                 struct {
 205                         struct netlbl_lsm_secattr_catmap *cat;
 206                         u32 lvl;
 207                 } mls;
 208                 u32 secid;
 209         } attr;
 210 };
 211
 212 /*
 213  * LSM security attribute operations (inline)
 214  */
 215
 216 /**
 217  * netlbl_secattr_cache_alloc - Allocate and initialize a secattr cache
 218  * @flags: the memory allocation flags
 219  *
 220  * Description:
 221  * Allocate and initialize a netlbl_lsm_cache structure.  Returns a pointer
 222  * on success, NULL on failure.
 223  *
 224  */
 225 static inline struct netlbl_lsm_cache *netlbl_secattr_cache_alloc(gfp_t flags)
 226 {
 227         struct netlbl_lsm_cache *cache;
 228
 229         cache = kzalloc(sizeof(*cache), flags);
 230         if (cache)
 231                 atomic_set(&cache->refcount, 1);
 232         return cache;
 233 }
 234
 235 /**
 236  * netlbl_secattr_cache_free - Frees a netlbl_lsm_cache struct
 237  * @cache: the struct to free
 238  *
 239  * Description:
 240  * Frees @secattr including all of the internal buffers.
 241  *
 242  */
 243 static inline void netlbl_secattr_cache_free(struct netlbl_lsm_cache *cache)
 244 {
 245         if (!atomic_dec_and_test(&cache->refcount))
 246                 return;
 247
 248         if (cache->free)
 249                 cache->free(cache->data);
 250         kfree(cache);
 251 }
 252
 253 /**
 254  * netlbl_secattr_catmap_alloc - Allocate a LSM secattr catmap
 255  * @flags: memory allocation flags
 256  *
 257  * Description:
 258  * Allocate memory for a LSM secattr catmap, returns a pointer on success, NULL
 259  * on failure.
 260  *
 261  */
 262 static inline struct netlbl_lsm_secattr_catmap *netlbl_secattr_catmap_alloc(
 263                                                                    gfp_t flags)
 264 {
 265         return kzalloc(sizeof(struct netlbl_lsm_secattr_catmap), flags);
 266 }
 267
 268 /**
 269  * netlbl_secattr_catmap_free - Free a LSM secattr catmap
 270  * @catmap: the category bitmap
 271  *
 272  * Description:
 273  * Free a LSM secattr catmap.
 274  *
 275  */
 276 static inline void netlbl_secattr_catmap_free(
 277                                       struct netlbl_lsm_secattr_catmap *catmap)
 278 {
 279         struct netlbl_lsm_secattr_catmap *iter;
 280
 281         do {
 282                 iter = catmap;
 283                 catmap = catmap->next;
 284                 kfree(iter);
 285         } while (catmap);
 286 }
 287
 288 /**
 289  * netlbl_secattr_init - Initialize a netlbl_lsm_secattr struct
 290  * @secattr: the struct to initialize
 291  *
 292  * Description:
 293  * Initialize an already allocated netlbl_lsm_secattr struct.
 294  *
 295  */
 296 static inline void netlbl_secattr_init(struct netlbl_lsm_secattr *secattr)
 297 {
 298         memset(secattr, 0, sizeof(*secattr));
 299 }
 300
 301 /**
 302  * netlbl_secattr_destroy - Clears a netlbl_lsm_secattr struct
 303  * @secattr: the struct to clear
 304  *
 305  * Description:
 306  * Destroys the @secattr struct, including freeing all of the internal buffers.
 307  * The struct must be reset with a call to netlbl_secattr_init() before reuse.
 308  *
 309  */
 310 static inline void netlbl_secattr_destroy(struct netlbl_lsm_secattr *secattr)
 311 {
 312         if (secattr->flags & NETLBL_SECATTR_FREE_DOMAIN)
 313                 kfree(secattr->domain);
 314         if (secattr->flags & NETLBL_SECATTR_CACHE)
 315                 netlbl_secattr_cache_free(secattr->cache);
 316         if (secattr->flags & NETLBL_SECATTR_MLS_CAT)
 317                 netlbl_secattr_catmap_free(secattr->attr.mls.cat);
 318 }
 319
 320 /**
 321  * netlbl_secattr_alloc - Allocate and initialize a netlbl_lsm_secattr struct
 322  * @flags: the memory allocation flags
 323  *
 324  * Description:
 325  * Allocate and initialize a netlbl_lsm_secattr struct.  Returns a valid
 326  * pointer on success, or NULL on failure.
 327  *
 328  */
 329 static inline struct netlbl_lsm_secattr *netlbl_secattr_alloc(gfp_t flags)
 330 {
 331         return kzalloc(sizeof(struct netlbl_lsm_secattr), flags);
 332 }
 333
 334 /**
 335  * netlbl_secattr_free - Frees a netlbl_lsm_secattr struct
 336  * @secattr: the struct to free
 337  *
 338  * Description:
 339  * Frees @secattr including all of the internal buffers.
 340  *
 341  */
 342 static inline void netlbl_secattr_free(struct netlbl_lsm_secattr *secattr)
 343 {
 344         netlbl_secattr_destroy(secattr);
 345         kfree(secattr);
 346 }
 347
 348 #ifdef CONFIG_NETLABEL
 349 /*
 350  * LSM configuration operations
 351  */
 352 int netlbl_cfg_map_del(const char *domain, struct netlbl_audit *audit_info);
 353 int netlbl_cfg_unlbl_add_map(const char *domain,
 354                              struct netlbl_audit *audit_info);
 355 int netlbl_cfg_cipsov4_add(struct cipso_v4_doi *doi_def,
 356                            struct netlbl_audit *audit_info);
 357 int netlbl_cfg_cipsov4_add_map(struct cipso_v4_doi *doi_def,
 358                                const char *domain,
 359                                struct netlbl_audit *audit_info);
 360 int netlbl_cfg_cipsov4_del(u32 doi, 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_getattr(const struct sk_buff *skb,
 386                           u16 family,
 387                           struct netlbl_lsm_secattr *secattr);
 388 void netlbl_skbuff_err(struct sk_buff *skb, int error);
 389
 390 /*
 391  * LSM label mapping cache operations
 392  */
 393 void netlbl_cache_invalidate(void);
 394 int netlbl_cache_add(const struct sk_buff *skb,
 395                      const struct netlbl_lsm_secattr *secattr);
 396 #else
 397 static inline int netlbl_cfg_map_del(const char *domain,
 398                                      struct netlbl_audit *audit_info)
 399 {
 400         return -ENOSYS;
 401 }
 402 static inline int netlbl_cfg_unlbl_add_map(const char *domain,
 403                                            struct netlbl_audit *audit_info)
 404 {
 405         return -ENOSYS;
 406 }
 407 static inline int netlbl_cfg_cipsov4_add(struct cipso_v4_doi *doi_def,
 408                                          struct netlbl_audit *audit_info)
 409 {
 410         return -ENOSYS;
 411 }
 412 static inline int netlbl_cfg_cipsov4_add_map(struct cipso_v4_doi *doi_def,
 413                                              const char *domain,
 414                                              struct netlbl_audit *audit_info)
 415 {
 416         return -ENOSYS;
 417 }
 418 static inline int netlbl_cfg_cipsov4_del(u32 doi,
 419                                          struct netlbl_audit *audit_info)
 420 {
 421         return -ENOSYS;
 422 }
 423 static inline int netlbl_secattr_catmap_walk(
 424                                       struct netlbl_lsm_secattr_catmap *catmap,
 425                                       u32 offset)
 426 {
 427         return -ENOENT;
 428 }
 429 static inline int netlbl_secattr_catmap_walk_rng(
 430                                       struct netlbl_lsm_secattr_catmap *catmap,
 431                                       u32 offset)
 432 {
 433         return -ENOENT;
 434 }
 435 static inline int netlbl_secattr_catmap_setbit(
 436                                       struct netlbl_lsm_secattr_catmap *catmap,
 437                                       u32 bit,
 438                                       gfp_t flags)
 439 {
 440         return 0;
 441 }
 442 static inline int netlbl_secattr_catmap_setrng(
 443                                       struct netlbl_lsm_secattr_catmap *catmap,
 444                                       u32 start,
 445                                       u32 end,
 446                                       gfp_t flags)
 447 {
 448         return 0;
 449 }
 450 static inline int netlbl_enabled(void)
 451 {
 452         return 0;
 453 }
 454 static inline int netlbl_sock_setattr(struct sock *sk,
 455                                      const struct netlbl_lsm_secattr *secattr)
 456 {
 457         return -ENOSYS;
 458 }
 459 static inline int netlbl_sock_getattr(struct sock *sk,
 460                                       struct netlbl_lsm_secattr *secattr)
 461 {
 462         return -ENOSYS;
 463 }
 464 static inline int netlbl_skbuff_getattr(const struct sk_buff *skb,
 465                                         u16 family,
 466                                         struct netlbl_lsm_secattr *secattr)
 467 {
 468         return -ENOSYS;
 469 }
 470 static inline void netlbl_skbuff_err(struct sk_buff *skb, int error)
 471 {
 472         return;
 473 }
 474 static inline void netlbl_cache_invalidate(void)
 475 {
 476         return;
 477 }
 478 static inline int netlbl_cache_add(const struct sk_buff *skb,
 479                                    const struct netlbl_lsm_secattr *secattr)
 480 {
 481         return 0;
 482 }
 483 #endif /* CONFIG_NETLABEL */
 484
 485 #endif /* _NETLABEL_H */