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 /*
  40  * NetLabel - A management interface for maintaining network packet label
  41  *            mapping tables for explicit packet labling protocols.
  42  *
  43  * Network protocols such as CIPSO and RIPSO require a label translation layer
  44  * to convert the label on the packet into something meaningful on the host
  45  * machine.  In the current Linux implementation these mapping tables live
  46  * inside the kernel; NetLabel provides a mechanism for user space applications
  47  * to manage these mapping tables.
  48  *
  49  * NetLabel makes use of the Generic NETLINK mechanism as a transport layer to
  50  * send messages between kernel and user space.  The general format of a
  51  * NetLabel message is shown below:
  52  *
  53  *  +-----------------+-------------------+--------- --- -- -
  54  *  | struct nlmsghdr | struct genlmsghdr | payload
  55  *  +-----------------+-------------------+--------- --- -- -
  56  *
  57  * The 'nlmsghdr' and 'genlmsghdr' structs should be dealt with like normal.
  58  * The payload is dependent on the subsystem specified in the
  59  * 'nlmsghdr->nlmsg_type' and should be defined below, supporting functions
  60  * should be defined in the corresponding net/netlabel/netlabel_<subsys>.h|c
  61  * file.  All of the fields in the NetLabel payload are NETLINK attributes, see
  62  * the include/net/netlink.h file for more information on NETLINK attributes.
  63  *
  64  */
  65
  66 /*
  67  * NetLabel NETLINK protocol
  68  */
  69
  70 /* NetLabel NETLINK protocol version
  71  *  1: initial version
  72  *  2: added static labels for unlabeled connections
  73  */
  74 #define NETLBL_PROTO_VERSION            2
  75
  76 /* NetLabel NETLINK types/families */
  77 #define NETLBL_NLTYPE_NONE              0
  78 #define NETLBL_NLTYPE_MGMT              1
  79 #define NETLBL_NLTYPE_MGMT_NAME         "NLBL_MGMT"
  80 #define NETLBL_NLTYPE_RIPSO             2
  81 #define NETLBL_NLTYPE_RIPSO_NAME        "NLBL_RIPSO"
  82 #define NETLBL_NLTYPE_CIPSOV4           3
  83 #define NETLBL_NLTYPE_CIPSOV4_NAME      "NLBL_CIPSOv4"
  84 #define NETLBL_NLTYPE_CIPSOV6           4
  85 #define NETLBL_NLTYPE_CIPSOV6_NAME      "NLBL_CIPSOv6"
  86 #define NETLBL_NLTYPE_UNLABELED         5
  87 #define NETLBL_NLTYPE_UNLABELED_NAME    "NLBL_UNLBL"
  88
  89 /*
  90  * NetLabel - Kernel API for accessing the network packet label mappings.
  91  *
  92  * The following functions are provided for use by other kernel modules,
  93  * specifically kernel LSM modules, to provide a consistent, transparent API
  94  * for dealing with explicit packet labeling protocols such as CIPSO and
  95  * RIPSO.  The functions defined here are implemented in the
  96  * net/netlabel/netlabel_kapi.c file.
  97  *
  98  */
  99
 100 /* NetLabel audit information */
 101 struct netlbl_audit {
 102         u32 secid;
 103         uid_t loginuid;
 104 };
 105
 106 /* Domain mapping definition struct */
 107 struct netlbl_dom_map;
 108
 109 /* Domain mapping operations */
 110 int netlbl_domhsh_remove(const char *domain, struct netlbl_audit *audit_info);
 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 which attributes are contained in this structure
 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 #define NETLBL_SECATTR_NONE             0x00000000
 188 #define NETLBL_SECATTR_DOMAIN           0x00000001
 189 #define NETLBL_SECATTR_CACHE            0x00000002
 190 #define NETLBL_SECATTR_MLS_LVL          0x00000004
 191 #define NETLBL_SECATTR_MLS_CAT          0x00000008
 192 #define NETLBL_SECATTR_SECID            0x00000010
 193 #define NETLBL_SECATTR_CACHEABLE        (NETLBL_SECATTR_MLS_LVL | \
 194                                          NETLBL_SECATTR_MLS_CAT | \
 195                                          NETLBL_SECATTR_SECID)
 196 struct netlbl_lsm_secattr {
 197         u32 flags;
 198         u32 type;
 199         char *domain;
 200         struct netlbl_lsm_cache *cache;
 201         union {
 202                 struct {
 203                         struct netlbl_lsm_secattr_catmap *cat;
 204                         u32 lvl;
 205                 } mls;
 206                 u32 secid;
 207         } attr;
 208 };
 209
 210 /*
 211  * LSM security attribute operations (inline)
 212  */
 213
 214 /**
 215  * netlbl_secattr_cache_alloc - Allocate and initialize a secattr cache
 216  * @flags: the memory allocation flags
 217  *
 218  * Description:
 219  * Allocate and initialize a netlbl_lsm_cache structure.  Returns a pointer
 220  * on success, NULL on failure.
 221  *
 222  */
 223 static inline struct netlbl_lsm_cache *netlbl_secattr_cache_alloc(gfp_t flags)
 224 {
 225         struct netlbl_lsm_cache *cache;
 226
 227         cache = kzalloc(sizeof(*cache), flags);
 228         if (cache)
 229                 atomic_set(&cache->refcount, 1);
 230         return cache;
 231 }
 232
 233 /**
 234  * netlbl_secattr_cache_free - Frees a netlbl_lsm_cache struct
 235  * @cache: the struct to free
 236  *
 237  * Description:
 238  * Frees @secattr including all of the internal buffers.
 239  *
 240  */
 241 static inline void netlbl_secattr_cache_free(struct netlbl_lsm_cache *cache)
 242 {
 243         if (!atomic_dec_and_test(&cache->refcount))
 244                 return;
 245
 246         if (cache->free)
 247                 cache->free(cache->data);
 248         kfree(cache);
 249 }
 250
 251 /**
 252  * netlbl_secattr_catmap_alloc - Allocate a LSM secattr catmap
 253  * @flags: memory allocation flags
 254  *
 255  * Description:
 256  * Allocate memory for a LSM secattr catmap, returns a pointer on success, NULL
 257  * on failure.
 258  *
 259  */
 260 static inline struct netlbl_lsm_secattr_catmap *netlbl_secattr_catmap_alloc(
 261                                                                    gfp_t flags)
 262 {
 263         return kzalloc(sizeof(struct netlbl_lsm_secattr_catmap), flags);
 264 }
 265
 266 /**
 267  * netlbl_secattr_catmap_free - Free a LSM secattr catmap
 268  * @catmap: the category bitmap
 269  *
 270  * Description:
 271  * Free a LSM secattr catmap.
 272  *
 273  */
 274 static inline void netlbl_secattr_catmap_free(
 275                                       struct netlbl_lsm_secattr_catmap *catmap)
 276 {
 277         struct netlbl_lsm_secattr_catmap *iter;
 278
 279         do {
 280                 iter = catmap;
 281                 catmap = catmap->next;
 282                 kfree(iter);
 283         } while (catmap);
 284 }
 285
 286 /**
 287  * netlbl_secattr_init - Initialize a netlbl_lsm_secattr struct
 288  * @secattr: the struct to initialize
 289  *
 290  * Description:
 291  * Initialize an already allocated netlbl_lsm_secattr struct.
 292  *
 293  */
 294 static inline void netlbl_secattr_init(struct netlbl_lsm_secattr *secattr)
 295 {
 296         memset(secattr, 0, sizeof(*secattr));
 297 }
 298
 299 /**
 300  * netlbl_secattr_destroy - Clears a netlbl_lsm_secattr struct
 301  * @secattr: the struct to clear
 302  *
 303  * Description:
 304  * Destroys the @secattr struct, including freeing all of the internal buffers.
 305  * The struct must be reset with a call to netlbl_secattr_init() before reuse.
 306  *
 307  */
 308 static inline void netlbl_secattr_destroy(struct netlbl_lsm_secattr *secattr)
 309 {
 310         kfree(secattr->domain);
 311         if (secattr->flags & NETLBL_SECATTR_CACHE)
 312                 netlbl_secattr_cache_free(secattr->cache);
 313         if (secattr->flags & NETLBL_SECATTR_MLS_CAT)
 314                 netlbl_secattr_catmap_free(secattr->attr.mls.cat);
 315 }
 316
 317 /**
 318  * netlbl_secattr_alloc - Allocate and initialize a netlbl_lsm_secattr struct
 319  * @flags: the memory allocation flags
 320  *
 321  * Description:
 322  * Allocate and initialize a netlbl_lsm_secattr struct.  Returns a valid
 323  * pointer on success, or NULL on failure.
 324  *
 325  */
 326 static inline struct netlbl_lsm_secattr *netlbl_secattr_alloc(gfp_t flags)
 327 {
 328         return kzalloc(sizeof(struct netlbl_lsm_secattr), flags);
 329 }
 330
 331 /**
 332  * netlbl_secattr_free - Frees a netlbl_lsm_secattr struct
 333  * @secattr: the struct to free
 334  *
 335  * Description:
 336  * Frees @secattr including all of the internal buffers.
 337  *
 338  */
 339 static inline void netlbl_secattr_free(struct netlbl_lsm_secattr *secattr)
 340 {
 341         netlbl_secattr_destroy(secattr);
 342         kfree(secattr);
 343 }
 344
 345 #ifdef CONFIG_NETLABEL
 346 /*
 347  * LSM security attribute operations
 348  */
 349 int netlbl_secattr_catmap_walk(struct netlbl_lsm_secattr_catmap *catmap,
 350                                u32 offset);
 351 int netlbl_secattr_catmap_walk_rng(struct netlbl_lsm_secattr_catmap *catmap,
 352                                    u32 offset);
 353 int netlbl_secattr_catmap_setbit(struct netlbl_lsm_secattr_catmap *catmap,
 354                                  u32 bit,
 355                                  gfp_t flags);
 356 int netlbl_secattr_catmap_setrng(struct netlbl_lsm_secattr_catmap *catmap,
 357                                  u32 start,
 358                                  u32 end,
 359                                  gfp_t flags);
 360
 361 /*
 362  * LSM protocol operations (NetLabel LSM/kernel API)
 363  */
 364 int netlbl_enabled(void);
 365 int netlbl_sock_setattr(struct sock *sk,
 366                         const struct netlbl_lsm_secattr *secattr);
 367 int netlbl_sock_getattr(struct sock *sk,
 368                         struct netlbl_lsm_secattr *secattr);
 369 int netlbl_skbuff_getattr(const struct sk_buff *skb,
 370                           u16 family,
 371                           struct netlbl_lsm_secattr *secattr);
 372 void netlbl_skbuff_err(struct sk_buff *skb, int error);
 373
 374 /*
 375  * LSM label mapping cache operations
 376  */
 377 void netlbl_cache_invalidate(void);
 378 int netlbl_cache_add(const struct sk_buff *skb,
 379                      const struct netlbl_lsm_secattr *secattr);
 380 #else
 381 static inline int netlbl_secattr_catmap_walk(
 382                                       struct netlbl_lsm_secattr_catmap *catmap,
 383                                       u32 offset)
 384 {
 385         return -ENOENT;
 386 }
 387 static inline int netlbl_secattr_catmap_walk_rng(
 388                                       struct netlbl_lsm_secattr_catmap *catmap,
 389                                       u32 offset)
 390 {
 391         return -ENOENT;
 392 }
 393 static inline int netlbl_secattr_catmap_setbit(
 394                                       struct netlbl_lsm_secattr_catmap *catmap,
 395                                       u32 bit,
 396                                       gfp_t flags)
 397 {
 398         return 0;
 399 }
 400 static inline int netlbl_secattr_catmap_setrng(
 401                                       struct netlbl_lsm_secattr_catmap *catmap,
 402                                       u32 start,
 403                                       u32 end,
 404                                       gfp_t flags)
 405 {
 406         return 0;
 407 }
 408 static inline int netlbl_enabled(void)
 409 {
 410         return 0;
 411 }
 412 static inline int netlbl_sock_setattr(struct sock *sk,
 413                                      const struct netlbl_lsm_secattr *secattr)
 414 {
 415         return -ENOSYS;
 416 }
 417 static inline int netlbl_sock_getattr(struct sock *sk,
 418                                       struct netlbl_lsm_secattr *secattr)
 419 {
 420         return -ENOSYS;
 421 }
 422 static inline int netlbl_skbuff_getattr(const struct sk_buff *skb,
 423                                         u16 family,
 424                                         struct netlbl_lsm_secattr *secattr)
 425 {
 426         return -ENOSYS;
 427 }
 428 static inline void netlbl_skbuff_err(struct sk_buff *skb, int error)
 429 {
 430         return;
 431 }
 432 static inline void netlbl_cache_invalidate(void)
 433 {
 434         return;
 435 }
 436 static inline int netlbl_cache_add(const struct sk_buff *skb,
 437                                    const struct netlbl_lsm_secattr *secattr)
 438 {
 439         return 0;
 440 }
 441 #endif /* CONFIG_NETLABEL */
 442
 443 #endif /* _NETLABEL_H */