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 struct netlbl_lsm_secattr {
 136         u32 flags;
 137
 138         char *domain;
 139
 140         u32 mls_lvl;
 141         struct netlbl_lsm_secattr_catmap *mls_cat;
 142
 143         struct netlbl_lsm_cache *cache;
 144 };
 145
 146 /*
 147  * LSM security attribute operations (inline)
 148  */
 149
 150 /**
 151  * netlbl_secattr_cache_alloc - Allocate and initialize a secattr cache
 152  * @flags: the memory allocation flags
 153  *
 154  * Description:
 155  * Allocate and initialize a netlbl_lsm_cache structure.  Returns a pointer
 156  * on success, NULL on failure.
 157  *
 158  */
 159 static inline struct netlbl_lsm_cache *netlbl_secattr_cache_alloc(gfp_t flags)
 160 {
 161         struct netlbl_lsm_cache *cache;
 162
 163         cache = kzalloc(sizeof(*cache), flags);
 164         if (cache)
 165                 atomic_set(&cache->refcount, 1);
 166         return cache;
 167 }
 168
 169 /**
 170  * netlbl_secattr_cache_free - Frees a netlbl_lsm_cache struct
 171  * @cache: the struct to free
 172  *
 173  * Description:
 174  * Frees @secattr including all of the internal buffers.
 175  *
 176  */
 177 static inline void netlbl_secattr_cache_free(struct netlbl_lsm_cache *cache)
 178 {
 179         if (!atomic_dec_and_test(&cache->refcount))
 180                 return;
 181
 182         if (cache->free)
 183                 cache->free(cache->data);
 184         kfree(cache);
 185 }
 186
 187 /**
 188  * netlbl_secattr_catmap_alloc - Allocate a LSM secattr catmap
 189  * @flags: memory allocation flags
 190  *
 191  * Description:
 192  * Allocate memory for a LSM secattr catmap, returns a pointer on success, NULL
 193  * on failure.
 194  *
 195  */
 196 static inline struct netlbl_lsm_secattr_catmap *netlbl_secattr_catmap_alloc(
 197                                                                    gfp_t flags)
 198 {
 199         return kzalloc(sizeof(struct netlbl_lsm_secattr_catmap), flags);
 200 }
 201
 202 /**
 203  * netlbl_secattr_catmap_free - Free a LSM secattr catmap
 204  * @catmap: the category bitmap
 205  *
 206  * Description:
 207  * Free a LSM secattr catmap.
 208  *
 209  */
 210 static inline void netlbl_secattr_catmap_free(
 211                                       struct netlbl_lsm_secattr_catmap *catmap)
 212 {
 213         struct netlbl_lsm_secattr_catmap *iter;
 214
 215         do {
 216                 iter = catmap;
 217                 catmap = catmap->next;
 218                 kfree(iter);
 219         } while (catmap);
 220 }
 221
 222 /**
 223  * netlbl_secattr_init - Initialize a netlbl_lsm_secattr struct
 224  * @secattr: the struct to initialize
 225  *
 226  * Description:
 227  * Initialize an already allocated netlbl_lsm_secattr struct.
 228  *
 229  */
 230 static inline void netlbl_secattr_init(struct netlbl_lsm_secattr *secattr)
 231 {
 232         secattr->flags = 0;
 233         secattr->domain = NULL;
 234         secattr->mls_cat = NULL;
 235         secattr->cache = NULL;
 236 }
 237
 238 /**
 239  * netlbl_secattr_destroy - Clears a netlbl_lsm_secattr struct
 240  * @secattr: the struct to clear
 241  *
 242  * Description:
 243  * Destroys the @secattr struct, including freeing all of the internal buffers.
 244  * The struct must be reset with a call to netlbl_secattr_init() before reuse.
 245  *
 246  */
 247 static inline void netlbl_secattr_destroy(struct netlbl_lsm_secattr *secattr)
 248 {
 249         if (secattr->cache)
 250                 netlbl_secattr_cache_free(secattr->cache);
 251         kfree(secattr->domain);
 252         if (secattr->mls_cat)
 253                 netlbl_secattr_catmap_free(secattr->mls_cat);
 254 }
 255
 256 /**
 257  * netlbl_secattr_alloc - Allocate and initialize a netlbl_lsm_secattr struct
 258  * @flags: the memory allocation flags
 259  *
 260  * Description:
 261  * Allocate and initialize a netlbl_lsm_secattr struct.  Returns a valid
 262  * pointer on success, or NULL on failure.
 263  *
 264  */
 265 static inline struct netlbl_lsm_secattr *netlbl_secattr_alloc(gfp_t flags)
 266 {
 267         return kzalloc(sizeof(struct netlbl_lsm_secattr), flags);
 268 }
 269
 270 /**
 271  * netlbl_secattr_free - Frees a netlbl_lsm_secattr struct
 272  * @secattr: the struct to free
 273  *
 274  * Description:
 275  * Frees @secattr including all of the internal buffers.
 276  *
 277  */
 278 static inline void netlbl_secattr_free(struct netlbl_lsm_secattr *secattr)
 279 {
 280         netlbl_secattr_destroy(secattr);
 281         kfree(secattr);
 282 }
 283
 284 #ifdef CONFIG_NETLABEL
 285 /*
 286  * LSM security attribute operations
 287  */
 288 int netlbl_secattr_catmap_walk(struct netlbl_lsm_secattr_catmap *catmap,
 289                                u32 offset);
 290 int netlbl_secattr_catmap_walk_rng(struct netlbl_lsm_secattr_catmap *catmap,
 291                                    u32 offset);
 292 int netlbl_secattr_catmap_setbit(struct netlbl_lsm_secattr_catmap *catmap,
 293                                  u32 bit,
 294                                  gfp_t flags);
 295 int netlbl_secattr_catmap_setrng(struct netlbl_lsm_secattr_catmap *catmap,
 296                                  u32 start,
 297                                  u32 end,
 298                                  gfp_t flags);
 299
 300 /*
 301  * LSM protocol operations
 302  */
 303 int netlbl_enabled(void);
 304 int netlbl_sock_setattr(struct sock *sk,
 305                         const struct netlbl_lsm_secattr *secattr);
 306 int netlbl_sock_getattr(struct sock *sk,
 307                         struct netlbl_lsm_secattr *secattr);
 308 int netlbl_skbuff_getattr(const struct sk_buff *skb,
 309                           struct netlbl_lsm_secattr *secattr);
 310 void netlbl_skbuff_err(struct sk_buff *skb, int error);
 311
 312 /*
 313  * LSM label mapping cache operations
 314  */
 315 void netlbl_cache_invalidate(void);
 316 int netlbl_cache_add(const struct sk_buff *skb,
 317                      const struct netlbl_lsm_secattr *secattr);
 318 #else
 319 static inline int netlbl_secattr_catmap_walk(
 320                                       struct netlbl_lsm_secattr_catmap *catmap,
 321                                       u32 offset)
 322 {
 323         return -ENOENT;
 324 }
 325 static inline int netlbl_secattr_catmap_walk_rng(
 326                                       struct netlbl_lsm_secattr_catmap *catmap,
 327                                       u32 offset)
 328 {
 329         return -ENOENT;
 330 }
 331 static inline int netlbl_secattr_catmap_setbit(
 332                                       struct netlbl_lsm_secattr_catmap *catmap,
 333                                       u32 bit,
 334                                       gfp_t flags)
 335 {
 336         return 0;
 337 }
 338 static inline int netlbl_secattr_catmap_setrng(
 339                                       struct netlbl_lsm_secattr_catmap *catmap,
 340                                       u32 start,
 341                                       u32 end,
 342                                       gfp_t flags)
 343 {
 344         return 0;
 345 }
 346 static inline int netlbl_enabled(void)
 347 {
 348         return 0;
 349 }
 350 static inline int netlbl_sock_setattr(struct sock *sk,
 351                                      const struct netlbl_lsm_secattr *secattr)
 352 {
 353         return -ENOSYS;
 354 }
 355 static inline int netlbl_sock_getattr(struct sock *sk,
 356                                       struct netlbl_lsm_secattr *secattr)
 357 {
 358         return -ENOSYS;
 359 }
 360 static inline int netlbl_skbuff_getattr(const struct sk_buff *skb,
 361                                         struct netlbl_lsm_secattr *secattr)
 362 {
 363         return -ENOSYS;
 364 }
 365 static inline void netlbl_skbuff_err(struct sk_buff *skb, int error)
 366 {
 367         return;
 368 }
 369 static inline void netlbl_cache_invalidate(void)
 370 {
 371         return;
 372 }
 373 static inline int netlbl_cache_add(const struct sk_buff *skb,
 374                                    const struct netlbl_lsm_secattr *secattr)
 375 {
 376         return 0;
 377 }
 378 #endif /* CONFIG_NETLABEL */
 379
 380 #endif /* _NETLABEL_H */