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 and the
  76  *     CIPSO_V4_MAP_LOCAL CIPSO mapping was added
  77  */
  78 #define NETLBL_PROTO_VERSION            3
  79
  80 /* NetLabel NETLINK types/families */
  81 #define NETLBL_NLTYPE_NONE              0
  82 #define NETLBL_NLTYPE_MGMT              1
  83 #define NETLBL_NLTYPE_MGMT_NAME         "NLBL_MGMT"
  84 #define NETLBL_NLTYPE_RIPSO             2
  85 #define NETLBL_NLTYPE_RIPSO_NAME        "NLBL_RIPSO"
  86 #define NETLBL_NLTYPE_CIPSOV4           3
  87 #define NETLBL_NLTYPE_CIPSOV4_NAME      "NLBL_CIPSOv4"
  88 #define NETLBL_NLTYPE_CIPSOV6           4
  89 #define NETLBL_NLTYPE_CIPSOV6_NAME      "NLBL_CIPSOv6"
  90 #define NETLBL_NLTYPE_UNLABELED         5
  91 #define NETLBL_NLTYPE_UNLABELED_NAME    "NLBL_UNLBL"
  92 #define NETLBL_NLTYPE_ADDRSELECT        6
  93 #define NETLBL_NLTYPE_ADDRSELECT_NAME   "NLBL_ADRSEL"
  94
  95 /*
  96  * NetLabel - Kernel API for accessing the network packet label mappings.
  97  *
  98  * The following functions are provided for use by other kernel modules,
  99  * specifically kernel LSM modules, to provide a consistent, transparent API
 100  * for dealing with explicit packet labeling protocols such as CIPSO and
 101  * RIPSO.  The functions defined here are implemented in the
 102  * net/netlabel/netlabel_kapi.c file.
 103  *
 104  */
 105
 106 /* NetLabel audit information */
 107 struct netlbl_audit {
 108         u32 secid;
 109         uid_t loginuid;
 110         u32 sessionid;
 111 };
 112
 113 /*
 114  * LSM security attributes
 115  */
 116
 117 /**
 118  * struct netlbl_lsm_cache - NetLabel LSM security attribute cache
 119  * @refcount: atomic reference counter
 120  * @free: LSM supplied function to free the cache data
 121  * @data: LSM supplied cache data
 122  *
 123  * Description:
 124  * This structure is provided for LSMs which wish to make use of the NetLabel
 125  * caching mechanism to store LSM specific data/attributes in the NetLabel
 126  * cache.  If the LSM has to perform a lot of translation from the NetLabel
 127  * security attributes into it's own internal representation then the cache
 128  * mechanism can provide a way to eliminate some or all of that translation
 129  * overhead on a cache hit.
 130  *
 131  */
 132 struct netlbl_lsm_cache {
 133         atomic_t refcount;
 134         void (*free) (const void *data);
 135         void *data;
 136 };
 137
 138 /**
 139  * struct netlbl_lsm_secattr_catmap - NetLabel LSM secattr category bitmap
 140  * @startbit: the value of the lowest order bit in the bitmap
 141  * @bitmap: the category bitmap
 142  * @next: pointer to the next bitmap "node" or NULL
 143  *
 144  * Description:
 145  * This structure is used to represent category bitmaps.  Due to the large
 146  * number of categories supported by most labeling protocols it is not
 147  * practical to transfer a full bitmap internally so NetLabel adopts a sparse
 148  * bitmap structure modeled after SELinux's ebitmap structure.
 149  * The catmap bitmap field MUST be a power of two in length and large
 150  * enough to hold at least 240 bits.  Special care (i.e. check the code!)
 151  * should be used when changing these values as the LSM implementation
 152  * probably has functions which rely on the sizes of these types to speed
 153  * processing.
 154  *
 155  */
 156 #define NETLBL_CATMAP_MAPTYPE           u64
 157 #define NETLBL_CATMAP_MAPCNT            4
 158 #define NETLBL_CATMAP_MAPSIZE           (sizeof(NETLBL_CATMAP_MAPTYPE) * 8)
 159 #define NETLBL_CATMAP_SIZE              (NETLBL_CATMAP_MAPSIZE * \
 160                                          NETLBL_CATMAP_MAPCNT)
 161 #define NETLBL_CATMAP_BIT               (NETLBL_CATMAP_MAPTYPE)0x01
 162 struct netlbl_lsm_secattr_catmap {
 163         u32 startbit;
 164         NETLBL_CATMAP_MAPTYPE bitmap[NETLBL_CATMAP_MAPCNT];
 165         struct netlbl_lsm_secattr_catmap *next;
 166 };
 167
 168 /**
 169  * struct netlbl_lsm_secattr - NetLabel LSM security attributes
 170  * @flags: indicate structure attributes, see NETLBL_SECATTR_*
 171  * @type: indicate the NLTYPE of the attributes
 172  * @domain: the NetLabel LSM domain
 173  * @cache: NetLabel LSM specific cache
 174  * @attr.mls: MLS sensitivity label
 175  * @attr.mls.cat: MLS category bitmap
 176  * @attr.mls.lvl: MLS sensitivity level
 177  * @attr.secid: LSM specific secid token
 178  *
 179  * Description:
 180  * This structure is used to pass security attributes between NetLabel and the
 181  * LSM modules.  The flags field is used to specify which fields within the
 182  * struct are valid and valid values can be created by bitwise OR'ing the
 183  * NETLBL_SECATTR_* defines.  The domain field is typically set by the LSM to
 184  * specify domain specific configuration settings and is not usually used by
 185  * NetLabel itself when returning security attributes to the LSM.
 186  *
 187  */
 188 struct netlbl_lsm_secattr {
 189         u32 flags;
 190         /* bitmap values for 'flags' */
 191 #define NETLBL_SECATTR_NONE             0x00000000
 192 #define NETLBL_SECATTR_DOMAIN           0x00000001
 193 #define NETLBL_SECATTR_DOMAIN_CPY       (NETLBL_SECATTR_DOMAIN | \
 194                                          NETLBL_SECATTR_FREE_DOMAIN)
 195 #define NETLBL_SECATTR_CACHE            0x00000002
 196 #define NETLBL_SECATTR_MLS_LVL          0x00000004
 197 #define NETLBL_SECATTR_MLS_CAT          0x00000008
 198 #define NETLBL_SECATTR_SECID            0x00000010
 199         /* bitmap meta-values for 'flags' */
 200 #define NETLBL_SECATTR_FREE_DOMAIN      0x01000000
 201 #define NETLBL_SECATTR_CACHEABLE        (NETLBL_SECATTR_MLS_LVL | \
 202                                          NETLBL_SECATTR_MLS_CAT | \
 203                                          NETLBL_SECATTR_SECID)
 204         u32 type;
 205         char *domain;
 206         struct netlbl_lsm_cache *cache;
 207         struct {
 208                 struct {
 209                         struct netlbl_lsm_secattr_catmap *cat;
 210                         u32 lvl;
 211                 } mls;
 212                 u32 secid;
 213         } attr;
 214 };
 215
 216 /*
 217  * LSM security attribute operations (inline)
 218  */
 219
 220 /**
 221  * netlbl_secattr_cache_alloc - Allocate and initialize a secattr cache
 222  * @flags: the memory allocation flags
 223  *
 224  * Description:
 225  * Allocate and initialize a netlbl_lsm_cache structure.  Returns a pointer
 226  * on success, NULL on failure.
 227  *
 228  */
 229 static inline struct netlbl_lsm_cache *netlbl_secattr_cache_alloc(gfp_t flags)
 230 {
 231         struct netlbl_lsm_cache *cache;
 232
 233         cache = kzalloc(sizeof(*cache), flags);
 234         if (cache)
 235                 atomic_set(&cache->refcount, 1);
 236         return cache;
 237 }
 238
 239 /**
 240  * netlbl_secattr_cache_free - Frees a netlbl_lsm_cache struct
 241  * @cache: the struct to free
 242  *
 243  * Description:
 244  * Frees @secattr including all of the internal buffers.
 245  *
 246  */
 247 static inline void netlbl_secattr_cache_free(struct netlbl_lsm_cache *cache)
 248 {
 249         if (!atomic_dec_and_test(&cache->refcount))
 250                 return;
 251
 252         if (cache->free)
 253                 cache->free(cache->data);
 254         kfree(cache);
 255 }
 256
 257 /**
 258  * netlbl_secattr_catmap_alloc - Allocate a LSM secattr catmap
 259  * @flags: memory allocation flags
 260  *
 261  * Description:
 262  * Allocate memory for a LSM secattr catmap, returns a pointer on success, NULL
 263  * on failure.
 264  *
 265  */
 266 static inline struct netlbl_lsm_secattr_catmap *netlbl_secattr_catmap_alloc(
 267                                                                    gfp_t flags)
 268 {
 269         return kzalloc(sizeof(struct netlbl_lsm_secattr_catmap), flags);
 270 }
 271
 272 /**
 273  * netlbl_secattr_catmap_free - Free a LSM secattr catmap
 274  * @catmap: the category bitmap
 275  *
 276  * Description:
 277  * Free a LSM secattr catmap.
 278  *
 279  */
 280 static inline void netlbl_secattr_catmap_free(
 281                                       struct netlbl_lsm_secattr_catmap *catmap)
 282 {
 283         struct netlbl_lsm_secattr_catmap *iter;
 284
 285         do {
 286                 iter = catmap;
 287                 catmap = catmap->next;
 288                 kfree(iter);
 289         } while (catmap);
 290 }
 291
 292 /**
 293  * netlbl_secattr_init - Initialize a netlbl_lsm_secattr struct
 294  * @secattr: the struct to initialize
 295  *
 296  * Description:
 297  * Initialize an already allocated netlbl_lsm_secattr struct.
 298  *
 299  */
 300 static inline void netlbl_secattr_init(struct netlbl_lsm_secattr *secattr)
 301 {
 302         memset(secattr, 0, sizeof(*secattr));
 303 }
 304
 305 /**
 306  * netlbl_secattr_destroy - Clears a netlbl_lsm_secattr struct
 307  * @secattr: the struct to clear
 308  *
 309  * Description:
 310  * Destroys the @secattr struct, including freeing all of the internal buffers.
 311  * The struct must be reset with a call to netlbl_secattr_init() before reuse.
 312  *
 313  */
 314 static inline void netlbl_secattr_destroy(struct netlbl_lsm_secattr *secattr)
 315 {
 316         if (secattr->flags & NETLBL_SECATTR_FREE_DOMAIN)
 317                 kfree(secattr->domain);
 318         if (secattr->flags & NETLBL_SECATTR_CACHE)
 319                 netlbl_secattr_cache_free(secattr->cache);
 320         if (secattr->flags & NETLBL_SECATTR_MLS_CAT)
 321                 netlbl_secattr_catmap_free(secattr->attr.mls.cat);
 322 }
 323
 324 /**
 325  * netlbl_secattr_alloc - Allocate and initialize a netlbl_lsm_secattr struct
 326  * @flags: the memory allocation flags
 327  *
 328  * Description:
 329  * Allocate and initialize a netlbl_lsm_secattr struct.  Returns a valid
 330  * pointer on success, or NULL on failure.
 331  *
 332  */
 333 static inline struct netlbl_lsm_secattr *netlbl_secattr_alloc(gfp_t flags)
 334 {
 335         return kzalloc(sizeof(struct netlbl_lsm_secattr), flags);
 336 }
 337
 338 /**
 339  * netlbl_secattr_free - Frees a netlbl_lsm_secattr struct
 340  * @secattr: the struct to free
 341  *
 342  * Description:
 343  * Frees @secattr including all of the internal buffers.
 344  *
 345  */
 346 static inline void netlbl_secattr_free(struct netlbl_lsm_secattr *secattr)
 347 {
 348         netlbl_secattr_destroy(secattr);
 349         kfree(secattr);
 350 }
 351
 352 #ifdef CONFIG_NETLABEL
 353 /*
 354  * LSM configuration operations
 355  */
 356 int netlbl_cfg_map_del(const char *domain, struct netlbl_audit *audit_info);
 357 int netlbl_cfg_unlbl_add_map(const char *domain,
 358                              struct netlbl_audit *audit_info);
 359 int netlbl_cfg_cipsov4_add_map(struct cipso_v4_doi *doi_def,
 360                                const char *domain,
 361                                struct netlbl_audit *audit_info);
 362
 363 /*
 364  * LSM security attribute operations
 365  */
 366 int netlbl_secattr_catmap_walk(struct netlbl_lsm_secattr_catmap *catmap,
 367                                u32 offset);
 368 int netlbl_secattr_catmap_walk_rng(struct netlbl_lsm_secattr_catmap *catmap,
 369                                    u32 offset);
 370 int netlbl_secattr_catmap_setbit(struct netlbl_lsm_secattr_catmap *catmap,
 371                                  u32 bit,
 372                                  gfp_t flags);
 373 int netlbl_secattr_catmap_setrng(struct netlbl_lsm_secattr_catmap *catmap,
 374                                  u32 start,
 375                                  u32 end,
 376                                  gfp_t flags);
 377
 378 /*
 379  * LSM protocol operations (NetLabel LSM/kernel API)
 380  */
 381 int netlbl_enabled(void);
 382 int netlbl_sock_setattr(struct sock *sk,
 383                         const struct netlbl_lsm_secattr *secattr);
 384 void netlbl_sock_delattr(struct sock *sk);
 385 int netlbl_sock_getattr(struct sock *sk,
 386                         struct netlbl_lsm_secattr *secattr);
 387 int netlbl_conn_setattr(struct sock *sk,
 388                         struct sockaddr *addr,
 389                         const struct netlbl_lsm_secattr *secattr);
 390 int netlbl_skbuff_setattr(struct sk_buff *skb,
 391                           u16 family,
 392                           const struct netlbl_lsm_secattr *secattr);
 393 int netlbl_skbuff_getattr(const struct sk_buff *skb,
 394                           u16 family,
 395                           struct netlbl_lsm_secattr *secattr);
 396 void netlbl_skbuff_err(struct sk_buff *skb, int error, int gateway);
 397
 398 /*
 399  * LSM label mapping cache operations
 400  */
 401 void netlbl_cache_invalidate(void);
 402 int netlbl_cache_add(const struct sk_buff *skb,
 403                      const struct netlbl_lsm_secattr *secattr);
 404 #else
 405 static inline int netlbl_cfg_map_del(const char *domain,
 406                                      struct netlbl_audit *audit_info)
 407 {
 408         return -ENOSYS;
 409 }
 410 static inline int netlbl_cfg_unlbl_add_map(const char *domain,
 411                                            struct netlbl_audit *audit_info)
 412 {
 413         return -ENOSYS;
 414 }
 415 static inline int netlbl_cfg_cipsov4_add_map(struct cipso_v4_doi *doi_def,
 416                                              const char *domain,
 417                                              struct netlbl_audit *audit_info)
 418 {
 419         return -ENOSYS;
 420 }
 421 static inline int netlbl_secattr_catmap_walk(
 422                                       struct netlbl_lsm_secattr_catmap *catmap,
 423                                       u32 offset)
 424 {
 425         return -ENOENT;
 426 }
 427 static inline int netlbl_secattr_catmap_walk_rng(
 428                                       struct netlbl_lsm_secattr_catmap *catmap,
 429                                       u32 offset)
 430 {
 431         return -ENOENT;
 432 }
 433 static inline int netlbl_secattr_catmap_setbit(
 434                                       struct netlbl_lsm_secattr_catmap *catmap,
 435                                       u32 bit,
 436                                       gfp_t flags)
 437 {
 438         return 0;
 439 }
 440 static inline int netlbl_secattr_catmap_setrng(
 441                                       struct netlbl_lsm_secattr_catmap *catmap,
 442                                       u32 start,
 443                                       u32 end,
 444                                       gfp_t flags)
 445 {
 446         return 0;
 447 }
 448 static inline int netlbl_enabled(void)
 449 {
 450         return 0;
 451 }
 452 static inline int netlbl_sock_setattr(struct sock *sk,
 453                                      const struct netlbl_lsm_secattr *secattr)
 454 {
 455         return -ENOSYS;
 456 }
 457 static inline void netlbl_sock_delattr(struct sock *sk)
 458 {
 459 }
 460 static inline int netlbl_sock_getattr(struct sock *sk,
 461                                       struct netlbl_lsm_secattr *secattr)
 462 {
 463         return -ENOSYS;
 464 }
 465 static inline int netlbl_conn_setattr(struct sock *sk,
 466                                       struct sockaddr *addr,
 467                                       const struct netlbl_lsm_secattr *secattr)
 468 {
 469         return -ENOSYS;
 470 }
 471 static inline int netlbl_skbuff_setattr(struct sk_buff *skb,
 472                                       u16 family,
 473                                       const struct netlbl_lsm_secattr *secattr)
 474 {
 475         return -ENOSYS;
 476 }
 477 static inline int netlbl_skbuff_getattr(const struct sk_buff *skb,
 478                                         u16 family,
 479                                         struct netlbl_lsm_secattr *secattr)
 480 {
 481         return -ENOSYS;
 482 }
 483 static inline void netlbl_skbuff_err(struct sk_buff *skb,
 484                                      int error,
 485                                      int gateway)
 486 {
 487         return;
 488 }
 489 static inline void netlbl_cache_invalidate(void)
 490 {
 491         return;
 492 }
 493 static inline int netlbl_cache_add(const struct sk_buff *skb,
 494                                    const struct netlbl_lsm_secattr *secattr)
 495 {
 496         return 0;
 497 }
 498 #endif /* CONFIG_NETLABEL */
 499
 500 #endif /* _NETLABEL_H */