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 #define NETLBL_PROTO_VERSION            1
  71
  72 /* NetLabel NETLINK types/families */
  73 #define NETLBL_NLTYPE_NONE              0
  74 #define NETLBL_NLTYPE_MGMT              1
  75 #define NETLBL_NLTYPE_MGMT_NAME         "NLBL_MGMT"
  76 #define NETLBL_NLTYPE_RIPSO             2
  77 #define NETLBL_NLTYPE_RIPSO_NAME        "NLBL_RIPSO"
  78 #define NETLBL_NLTYPE_CIPSOV4           3
  79 #define NETLBL_NLTYPE_CIPSOV4_NAME      "NLBL_CIPSOv4"
  80 #define NETLBL_NLTYPE_CIPSOV6           4
  81 #define NETLBL_NLTYPE_CIPSOV6_NAME      "NLBL_CIPSOv6"
  82 #define NETLBL_NLTYPE_UNLABELED         5
  83 #define NETLBL_NLTYPE_UNLABELED_NAME    "NLBL_UNLBL"
  84
  85 /*
  86  * NetLabel - Kernel API for accessing the network packet label mappings.
  87  *
  88  * The following functions are provided for use by other kernel modules,
  89  * specifically kernel LSM modules, to provide a consistent, transparent API
  90  * for dealing with explicit packet labeling protocols such as CIPSO and
  91  * RIPSO.  The functions defined here are implemented in the
  92  * net/netlabel/netlabel_kapi.c file.
  93  *
  94  */
  95
  96 /* NetLabel audit information */
  97 struct netlbl_audit {
  98         u32 secid;
  99         uid_t loginuid;
 100 };
 101
 102 /* Domain mapping definition struct */
 103 struct netlbl_dom_map;
 104
 105 /* Domain mapping operations */
 106 int netlbl_domhsh_remove(const char *domain, struct netlbl_audit *audit_info);
 107
 108 /* LSM security attributes */
 109 struct netlbl_lsm_cache {
 110         atomic_t refcount;
 111         void (*free) (const void *data);
 112         void *data;
 113 };
 114 /* The catmap bitmap field MUST be a power of two in length and large
 115  * enough to hold at least 240 bits.  Special care (i.e. check the code!)
 116  * should be used when changing these values as the LSM implementation
 117  * probably has functions which rely on the sizes of these types to speed
 118  * processing. */
 119 #define NETLBL_CATMAP_MAPTYPE           u64
 120 #define NETLBL_CATMAP_MAPCNT            4
 121 #define NETLBL_CATMAP_MAPSIZE           (sizeof(NETLBL_CATMAP_MAPTYPE) * 8)
 122 #define NETLBL_CATMAP_SIZE              (NETLBL_CATMAP_MAPSIZE * \
 123                                          NETLBL_CATMAP_MAPCNT)
 124 #define NETLBL_CATMAP_BIT               (NETLBL_CATMAP_MAPTYPE)0x01
 125 struct netlbl_lsm_secattr_catmap {
 126         u32 startbit;
 127         NETLBL_CATMAP_MAPTYPE bitmap[NETLBL_CATMAP_MAPCNT];
 128         struct netlbl_lsm_secattr_catmap *next;
 129 };
 130 #define NETLBL_SECATTR_NONE             0x00000000
 131 #define NETLBL_SECATTR_DOMAIN           0x00000001
 132 #define NETLBL_SECATTR_CACHE            0x00000002
 133 #define NETLBL_SECATTR_MLS_LVL          0x00000004
 134 #define NETLBL_SECATTR_MLS_CAT          0x00000008
 135 #define NETLBL_SECATTR_CACHEABLE        (NETLBL_SECATTR_MLS_LVL | \
 136                                          NETLBL_SECATTR_MLS_CAT)
 137 struct netlbl_lsm_secattr {
 138         u32 flags;
 139
 140         char *domain;
 141
 142         u32 mls_lvl;
 143         struct netlbl_lsm_secattr_catmap *mls_cat;
 144
 145         struct netlbl_lsm_cache *cache;
 146 };
 147
 148 /*
 149  * LSM security attribute operations (inline)
 150  */
 151
 152 /**
 153  * netlbl_secattr_cache_alloc - Allocate and initialize a secattr cache
 154  * @flags: the memory allocation flags
 155  *
 156  * Description:
 157  * Allocate and initialize a netlbl_lsm_cache structure.  Returns a pointer
 158  * on success, NULL on failure.
 159  *
 160  */
 161 static inline struct netlbl_lsm_cache *netlbl_secattr_cache_alloc(gfp_t flags)
 162 {
 163         struct netlbl_lsm_cache *cache;
 164
 165         cache = kzalloc(sizeof(*cache), flags);
 166         if (cache)
 167                 atomic_set(&cache->refcount, 1);
 168         return cache;
 169 }
 170
 171 /**
 172  * netlbl_secattr_cache_free - Frees a netlbl_lsm_cache struct
 173  * @cache: the struct to free
 174  *
 175  * Description:
 176  * Frees @secattr including all of the internal buffers.
 177  *
 178  */
 179 static inline void netlbl_secattr_cache_free(struct netlbl_lsm_cache *cache)
 180 {
 181         if (!atomic_dec_and_test(&cache->refcount))
 182                 return;
 183
 184         if (cache->free)
 185                 cache->free(cache->data);
 186         kfree(cache);
 187 }
 188
 189 /**
 190  * netlbl_secattr_catmap_alloc - Allocate a LSM secattr catmap
 191  * @flags: memory allocation flags
 192  *
 193  * Description:
 194  * Allocate memory for a LSM secattr catmap, returns a pointer on success, NULL
 195  * on failure.
 196  *
 197  */
 198 static inline struct netlbl_lsm_secattr_catmap *netlbl_secattr_catmap_alloc(
 199                                                                    gfp_t flags)
 200 {
 201         return kzalloc(sizeof(struct netlbl_lsm_secattr_catmap), flags);
 202 }
 203
 204 /**
 205  * netlbl_secattr_catmap_free - Free a LSM secattr catmap
 206  * @catmap: the category bitmap
 207  *
 208  * Description:
 209  * Free a LSM secattr catmap.
 210  *
 211  */
 212 static inline void netlbl_secattr_catmap_free(
 213                                       struct netlbl_lsm_secattr_catmap *catmap)
 214 {
 215         struct netlbl_lsm_secattr_catmap *iter;
 216
 217         do {
 218                 iter = catmap;
 219                 catmap = catmap->next;
 220                 kfree(iter);
 221         } while (catmap);
 222 }
 223
 224 /**
 225  * netlbl_secattr_init - Initialize a netlbl_lsm_secattr struct
 226  * @secattr: the struct to initialize
 227  *
 228  * Description:
 229  * Initialize an already allocated netlbl_lsm_secattr struct.
 230  *
 231  */
 232 static inline void netlbl_secattr_init(struct netlbl_lsm_secattr *secattr)
 233 {
 234         secattr->flags = 0;
 235         secattr->domain = NULL;
 236         secattr->mls_cat = NULL;
 237         secattr->cache = NULL;
 238 }
 239
 240 /**
 241  * netlbl_secattr_destroy - Clears a netlbl_lsm_secattr struct
 242  * @secattr: the struct to clear
 243  *
 244  * Description:
 245  * Destroys the @secattr struct, including freeing all of the internal buffers.
 246  * The struct must be reset with a call to netlbl_secattr_init() before reuse.
 247  *
 248  */
 249 static inline void netlbl_secattr_destroy(struct netlbl_lsm_secattr *secattr)
 250 {
 251         if (secattr->cache)
 252                 netlbl_secattr_cache_free(secattr->cache);
 253         kfree(secattr->domain);
 254         if (secattr->mls_cat)
 255                 netlbl_secattr_catmap_free(secattr->mls_cat);
 256 }
 257
 258 /**
 259  * netlbl_secattr_alloc - Allocate and initialize a netlbl_lsm_secattr struct
 260  * @flags: the memory allocation flags
 261  *
 262  * Description:
 263  * Allocate and initialize a netlbl_lsm_secattr struct.  Returns a valid
 264  * pointer on success, or NULL on failure.
 265  *
 266  */
 267 static inline struct netlbl_lsm_secattr *netlbl_secattr_alloc(gfp_t flags)
 268 {
 269         return kzalloc(sizeof(struct netlbl_lsm_secattr), flags);
 270 }
 271
 272 /**
 273  * netlbl_secattr_free - Frees a netlbl_lsm_secattr struct
 274  * @secattr: the struct to free
 275  *
 276  * Description:
 277  * Frees @secattr including all of the internal buffers.
 278  *
 279  */
 280 static inline void netlbl_secattr_free(struct netlbl_lsm_secattr *secattr)
 281 {
 282         netlbl_secattr_destroy(secattr);
 283         kfree(secattr);
 284 }
 285
 286 #ifdef CONFIG_NETLABEL
 287 /*
 288  * LSM security attribute operations
 289  */
 290 int netlbl_secattr_catmap_walk(struct netlbl_lsm_secattr_catmap *catmap,
 291                                u32 offset);
 292 int netlbl_secattr_catmap_walk_rng(struct netlbl_lsm_secattr_catmap *catmap,
 293                                    u32 offset);
 294 int netlbl_secattr_catmap_setbit(struct netlbl_lsm_secattr_catmap *catmap,
 295                                  u32 bit,
 296                                  gfp_t flags);
 297 int netlbl_secattr_catmap_setrng(struct netlbl_lsm_secattr_catmap *catmap,
 298                                  u32 start,
 299                                  u32 end,
 300                                  gfp_t flags);
 301
 302 /*
 303  * LSM protocol operations
 304  */
 305 int netlbl_enabled(void);
 306 int netlbl_sock_setattr(struct sock *sk,
 307                         const struct netlbl_lsm_secattr *secattr);
 308 int netlbl_sock_getattr(struct sock *sk,
 309                         struct netlbl_lsm_secattr *secattr);
 310 int netlbl_skbuff_getattr(const struct sk_buff *skb,
 311                           struct netlbl_lsm_secattr *secattr);
 312 void netlbl_skbuff_err(struct sk_buff *skb, int error);
 313
 314 /*
 315  * LSM label mapping cache operations
 316  */
 317 void netlbl_cache_invalidate(void);
 318 int netlbl_cache_add(const struct sk_buff *skb,
 319                      const struct netlbl_lsm_secattr *secattr);
 320 #else
 321 static inline int netlbl_secattr_catmap_walk(
 322                                       struct netlbl_lsm_secattr_catmap *catmap,
 323                                       u32 offset)
 324 {
 325         return -ENOENT;
 326 }
 327 static inline int netlbl_secattr_catmap_walk_rng(
 328                                       struct netlbl_lsm_secattr_catmap *catmap,
 329                                       u32 offset)
 330 {
 331         return -ENOENT;
 332 }
 333 static inline int netlbl_secattr_catmap_setbit(
 334                                       struct netlbl_lsm_secattr_catmap *catmap,
 335                                       u32 bit,
 336                                       gfp_t flags)
 337 {
 338         return 0;
 339 }
 340 static inline int netlbl_secattr_catmap_setrng(
 341                                       struct netlbl_lsm_secattr_catmap *catmap,
 342                                       u32 start,
 343                                       u32 end,
 344                                       gfp_t flags)
 345 {
 346         return 0;
 347 }
 348 static inline int netlbl_enabled(void)
 349 {
 350         return 0;
 351 }
 352 static inline int netlbl_sock_setattr(struct sock *sk,
 353                                      const struct netlbl_lsm_secattr *secattr)
 354 {
 355         return -ENOSYS;
 356 }
 357 static inline int netlbl_sock_getattr(struct sock *sk,
 358                                       struct netlbl_lsm_secattr *secattr)
 359 {
 360         return -ENOSYS;
 361 }
 362 static inline int netlbl_skbuff_getattr(const struct sk_buff *skb,
 363                                         struct netlbl_lsm_secattr *secattr)
 364 {
 365         return -ENOSYS;
 366 }
 367 static inline void netlbl_skbuff_err(struct sk_buff *skb, int error)
 368 {
 369         return;
 370 }
 371 static inline void netlbl_cache_invalidate(void)
 372 {
 373         return;
 374 }
 375 static inline int netlbl_cache_add(const struct sk_buff *skb,
 376                                    const struct netlbl_lsm_secattr *secattr)
 377 {
 378         return 0;
 379 }
 380 #endif /* CONFIG_NETLABEL */
 381
 382 #endif /* _NETLABEL_H */