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 <linux/in.h>
  37 #include <linux/in6.h>
  38 #include <net/netlink.h>
  39 #include <net/request_sock.h>
  40 #include <asm/atomic.h>
  41
  42 struct cipso_v4_doi;
  43
  44 /*
  45  * NetLabel - A management interface for maintaining network packet label
  46  *            mapping tables for explicit packet labling protocols.
  47  *
  48  * Network protocols such as CIPSO and RIPSO require a label translation layer
  49  * to convert the label on the packet into something meaningful on the host
  50  * machine.  In the current Linux implementation these mapping tables live
  51  * inside the kernel; NetLabel provides a mechanism for user space applications
  52  * to manage these mapping tables.
  53  *
  54  * NetLabel makes use of the Generic NETLINK mechanism as a transport layer to
  55  * send messages between kernel and user space.  The general format of a
  56  * NetLabel message is shown below:
  57  *
  58  *  +-----------------+-------------------+--------- --- -- -
  59  *  | struct nlmsghdr | struct genlmsghdr | payload
  60  *  +-----------------+-------------------+--------- --- -- -
  61  *
  62  * The 'nlmsghdr' and 'genlmsghdr' structs should be dealt with like normal.
  63  * The payload is dependent on the subsystem specified in the
  64  * 'nlmsghdr->nlmsg_type' and should be defined below, supporting functions
  65  * should be defined in the corresponding net/netlabel/netlabel_<subsys>.h|c
  66  * file.  All of the fields in the NetLabel payload are NETLINK attributes, see
  67  * the include/net/netlink.h file for more information on NETLINK attributes.
  68  *
  69  */
  70
  71 /*
  72  * NetLabel NETLINK protocol
  73  */
  74
  75 /* NetLabel NETLINK protocol version
  76  *  1: initial version
  77  *  2: added static labels for unlabeled connections
  78  *  3: network selectors added to the NetLabel/LSM domain mapping and the
  79  *     CIPSO_V4_MAP_LOCAL CIPSO mapping was added
  80  */
  81 #define NETLBL_PROTO_VERSION            3
  82
  83 /* NetLabel NETLINK types/families */
  84 #define NETLBL_NLTYPE_NONE              0
  85 #define NETLBL_NLTYPE_MGMT              1
  86 #define NETLBL_NLTYPE_MGMT_NAME         "NLBL_MGMT"
  87 #define NETLBL_NLTYPE_RIPSO             2
  88 #define NETLBL_NLTYPE_RIPSO_NAME        "NLBL_RIPSO"
  89 #define NETLBL_NLTYPE_CIPSOV4           3
  90 #define NETLBL_NLTYPE_CIPSOV4_NAME      "NLBL_CIPSOv4"
  91 #define NETLBL_NLTYPE_CIPSOV6           4
  92 #define NETLBL_NLTYPE_CIPSOV6_NAME      "NLBL_CIPSOv6"
  93 #define NETLBL_NLTYPE_UNLABELED         5
  94 #define NETLBL_NLTYPE_UNLABELED_NAME    "NLBL_UNLBL"
  95 #define NETLBL_NLTYPE_ADDRSELECT        6
  96 #define NETLBL_NLTYPE_ADDRSELECT_NAME   "NLBL_ADRSEL"
  97
  98 /*
  99  * NetLabel - Kernel API for accessing the network packet label mappings.
 100  *
 101  * The following functions are provided for use by other kernel modules,
 102  * specifically kernel LSM modules, to provide a consistent, transparent API
 103  * for dealing with explicit packet labeling protocols such as CIPSO and
 104  * RIPSO.  The functions defined here are implemented in the
 105  * net/netlabel/netlabel_kapi.c file.
 106  *
 107  */
 108
 109 /* NetLabel audit information */
 110 struct netlbl_audit {
 111         u32 secid;
 112         uid_t loginuid;
 113         u32 sessionid;
 114 };
 115
 116 /*
 117  * LSM security attributes
 118  */
 119
 120 /**
 121  * struct netlbl_lsm_cache - NetLabel LSM security attribute cache
 122  * @refcount: atomic reference counter
 123  * @free: LSM supplied function to free the cache data
 124  * @data: LSM supplied cache data
 125  *
 126  * Description:
 127  * This structure is provided for LSMs which wish to make use of the NetLabel
 128  * caching mechanism to store LSM specific data/attributes in the NetLabel
 129  * cache.  If the LSM has to perform a lot of translation from the NetLabel
 130  * security attributes into it's own internal representation then the cache
 131  * mechanism can provide a way to eliminate some or all of that translation
 132  * overhead on a cache hit.
 133  *
 134  */
 135 struct netlbl_lsm_cache {
 136         atomic_t refcount;
 137         void (*free) (const void *data);
 138         void *data;
 139 };
 140
 141 /**
 142  * struct netlbl_lsm_secattr_catmap - NetLabel LSM secattr category bitmap
 143  * @startbit: the value of the lowest order bit in the bitmap
 144  * @bitmap: the category bitmap
 145  * @next: pointer to the next bitmap "node" or NULL
 146  *
 147  * Description:
 148  * This structure is used to represent category bitmaps.  Due to the large
 149  * number of categories supported by most labeling protocols it is not
 150  * practical to transfer a full bitmap internally so NetLabel adopts a sparse
 151  * bitmap structure modeled after SELinux's ebitmap structure.
 152  * The catmap bitmap field MUST be a power of two in length and large
 153  * enough to hold at least 240 bits.  Special care (i.e. check the code!)
 154  * should be used when changing these values as the LSM implementation
 155  * probably has functions which rely on the sizes of these types to speed
 156  * processing.
 157  *
 158  */
 159 #define NETLBL_CATMAP_MAPTYPE           u64
 160 #define NETLBL_CATMAP_MAPCNT            4
 161 #define NETLBL_CATMAP_MAPSIZE           (sizeof(NETLBL_CATMAP_MAPTYPE) * 8)
 162 #define NETLBL_CATMAP_SIZE              (NETLBL_CATMAP_MAPSIZE * \
 163                                          NETLBL_CATMAP_MAPCNT)
 164 #define NETLBL_CATMAP_BIT               (NETLBL_CATMAP_MAPTYPE)0x01
 165 struct netlbl_lsm_secattr_catmap {
 166         u32 startbit;
 167         NETLBL_CATMAP_MAPTYPE bitmap[NETLBL_CATMAP_MAPCNT];
 168         struct netlbl_lsm_secattr_catmap *next;
 169 };
 170
 171 /**
 172  * struct netlbl_lsm_secattr - NetLabel LSM security attributes
 173  * @flags: indicate structure attributes, see NETLBL_SECATTR_*
 174  * @type: indicate the NLTYPE of the attributes
 175  * @domain: the NetLabel LSM domain
 176  * @cache: NetLabel LSM specific cache
 177  * @attr.mls: MLS sensitivity label
 178  * @attr.mls.cat: MLS category bitmap
 179  * @attr.mls.lvl: MLS sensitivity level
 180  * @attr.secid: LSM specific secid token
 181  *
 182  * Description:
 183  * This structure is used to pass security attributes between NetLabel and the
 184  * LSM modules.  The flags field is used to specify which fields within the
 185  * struct are valid and valid values can be created by bitwise OR'ing the
 186  * NETLBL_SECATTR_* defines.  The domain field is typically set by the LSM to
 187  * specify domain specific configuration settings and is not usually used by
 188  * NetLabel itself when returning security attributes to the LSM.
 189  *
 190  */
 191 struct netlbl_lsm_secattr {
 192         u32 flags;
 193         /* bitmap values for 'flags' */
 194 #define NETLBL_SECATTR_NONE             0x00000000
 195 #define NETLBL_SECATTR_DOMAIN           0x00000001
 196 #define NETLBL_SECATTR_DOMAIN_CPY       (NETLBL_SECATTR_DOMAIN | \
 197                                          NETLBL_SECATTR_FREE_DOMAIN)
 198 #define NETLBL_SECATTR_CACHE            0x00000002
 199 #define NETLBL_SECATTR_MLS_LVL          0x00000004
 200 #define NETLBL_SECATTR_MLS_CAT          0x00000008
 201 #define NETLBL_SECATTR_SECID            0x00000010
 202         /* bitmap meta-values for 'flags' */
 203 #define NETLBL_SECATTR_FREE_DOMAIN      0x01000000
 204 #define NETLBL_SECATTR_CACHEABLE        (NETLBL_SECATTR_MLS_LVL | \
 205                                          NETLBL_SECATTR_MLS_CAT | \
 206                                          NETLBL_SECATTR_SECID)
 207         u32 type;
 208         char *domain;
 209         struct netlbl_lsm_cache *cache;
 210         struct {
 211                 struct {
 212                         struct netlbl_lsm_secattr_catmap *cat;
 213                         u32 lvl;
 214                 } mls;
 215                 u32 secid;
 216         } attr;
 217 };
 218
 219 /*
 220  * LSM security attribute operations (inline)
 221  */
 222
 223 /**
 224  * netlbl_secattr_cache_alloc - Allocate and initialize a secattr cache
 225  * @flags: the memory allocation flags
 226  *
 227  * Description:
 228  * Allocate and initialize a netlbl_lsm_cache structure.  Returns a pointer
 229  * on success, NULL on failure.
 230  *
 231  */
 232 static inline struct netlbl_lsm_cache *netlbl_secattr_cache_alloc(gfp_t flags)
 233 {
 234         struct netlbl_lsm_cache *cache;
 235
 236         cache = kzalloc(sizeof(*cache), flags);
 237         if (cache)
 238                 atomic_set(&cache->refcount, 1);
 239         return cache;
 240 }
 241
 242 /**
 243  * netlbl_secattr_cache_free - Frees a netlbl_lsm_cache struct
 244  * @cache: the struct to free
 245  *
 246  * Description:
 247  * Frees @secattr including all of the internal buffers.
 248  *
 249  */
 250 static inline void netlbl_secattr_cache_free(struct netlbl_lsm_cache *cache)
 251 {
 252         if (!atomic_dec_and_test(&cache->refcount))
 253                 return;
 254
 255         if (cache->free)
 256                 cache->free(cache->data);
 257         kfree(cache);
 258 }
 259
 260 /**
 261  * netlbl_secattr_catmap_alloc - Allocate a LSM secattr catmap
 262  * @flags: memory allocation flags
 263  *
 264  * Description:
 265  * Allocate memory for a LSM secattr catmap, returns a pointer on success, NULL
 266  * on failure.
 267  *
 268  */
 269 static inline struct netlbl_lsm_secattr_catmap *netlbl_secattr_catmap_alloc(
 270                                                                    gfp_t flags)
 271 {
 272         return kzalloc(sizeof(struct netlbl_lsm_secattr_catmap), flags);
 273 }
 274
 275 /**
 276  * netlbl_secattr_catmap_free - Free a LSM secattr catmap
 277  * @catmap: the category bitmap
 278  *
 279  * Description:
 280  * Free a LSM secattr catmap.
 281  *
 282  */
 283 static inline void netlbl_secattr_catmap_free(
 284                                       struct netlbl_lsm_secattr_catmap *catmap)
 285 {
 286         struct netlbl_lsm_secattr_catmap *iter;
 287
 288         do {
 289                 iter = catmap;
 290                 catmap = catmap->next;
 291                 kfree(iter);
 292         } while (catmap);
 293 }
 294
 295 /**
 296  * netlbl_secattr_init - Initialize a netlbl_lsm_secattr struct
 297  * @secattr: the struct to initialize
 298  *
 299  * Description:
 300  * Initialize an already allocated netlbl_lsm_secattr struct.
 301  *
 302  */
 303 static inline void netlbl_secattr_init(struct netlbl_lsm_secattr *secattr)
 304 {
 305         memset(secattr, 0, sizeof(*secattr));
 306 }
 307
 308 /**
 309  * netlbl_secattr_destroy - Clears a netlbl_lsm_secattr struct
 310  * @secattr: the struct to clear
 311  *
 312  * Description:
 313  * Destroys the @secattr struct, including freeing all of the internal buffers.
 314  * The struct must be reset with a call to netlbl_secattr_init() before reuse.
 315  *
 316  */
 317 static inline void netlbl_secattr_destroy(struct netlbl_lsm_secattr *secattr)
 318 {
 319         if (secattr->flags & NETLBL_SECATTR_FREE_DOMAIN)
 320                 kfree(secattr->domain);
 321         if (secattr->flags & NETLBL_SECATTR_CACHE)
 322                 netlbl_secattr_cache_free(secattr->cache);
 323         if (secattr->flags & NETLBL_SECATTR_MLS_CAT)
 324                 netlbl_secattr_catmap_free(secattr->attr.mls.cat);
 325 }
 326
 327 /**
 328  * netlbl_secattr_alloc - Allocate and initialize a netlbl_lsm_secattr struct
 329  * @flags: the memory allocation flags
 330  *
 331  * Description:
 332  * Allocate and initialize a netlbl_lsm_secattr struct.  Returns a valid
 333  * pointer on success, or NULL on failure.
 334  *
 335  */
 336 static inline struct netlbl_lsm_secattr *netlbl_secattr_alloc(gfp_t flags)
 337 {
 338         return kzalloc(sizeof(struct netlbl_lsm_secattr), flags);
 339 }
 340
 341 /**
 342  * netlbl_secattr_free - Frees a netlbl_lsm_secattr struct
 343  * @secattr: the struct to free
 344  *
 345  * Description:
 346  * Frees @secattr including all of the internal buffers.
 347  *
 348  */
 349 static inline void netlbl_secattr_free(struct netlbl_lsm_secattr *secattr)
 350 {
 351         netlbl_secattr_destroy(secattr);
 352         kfree(secattr);
 353 }
 354
 355 #ifdef CONFIG_NETLABEL
 356 /*
 357  * LSM configuration operations
 358  */
 359 int netlbl_cfg_map_del(const char *domain,
 360                        u16 family,
 361                        const void *addr,
 362                        const void *mask,
 363                        struct netlbl_audit *audit_info);
 364 int netlbl_cfg_unlbl_map_add(const char *domain,
 365                              u16 family,
 366                              const void *addr,
 367                              const void *mask,
 368                              struct netlbl_audit *audit_info);
 369 int netlbl_cfg_unlbl_static_add(struct net *net,
 370                                 const char *dev_name,
 371                                 const void *addr,
 372                                 const void *mask,
 373                                 u16 family,
 374                                 u32 secid,
 375                                 struct netlbl_audit *audit_info);
 376 int netlbl_cfg_unlbl_static_del(struct net *net,
 377                                 const char *dev_name,
 378                                 const void *addr,
 379                                 const void *mask,
 380                                 u16 family,
 381                                 struct netlbl_audit *audit_info);
 382 int netlbl_cfg_cipsov4_add(struct cipso_v4_doi *doi_def,
 383                            struct netlbl_audit *audit_info);
 384 void netlbl_cfg_cipsov4_del(u32 doi, struct netlbl_audit *audit_info);
 385 int netlbl_cfg_cipsov4_map_add(u32 doi,
 386                                const char *domain,
 387                                const struct in_addr *addr,
 388                                const struct in_addr *mask,
 389                                struct netlbl_audit *audit_info);
 390 /*
 391  * LSM security attribute operations
 392  */
 393 int netlbl_secattr_catmap_walk(struct netlbl_lsm_secattr_catmap *catmap,
 394                                u32 offset);
 395 int netlbl_secattr_catmap_walk_rng(struct netlbl_lsm_secattr_catmap *catmap,
 396                                    u32 offset);
 397 int netlbl_secattr_catmap_setbit(struct netlbl_lsm_secattr_catmap *catmap,
 398                                  u32 bit,
 399                                  gfp_t flags);
 400 int netlbl_secattr_catmap_setrng(struct netlbl_lsm_secattr_catmap *catmap,
 401                                  u32 start,
 402                                  u32 end,
 403                                  gfp_t flags);
 404
 405 /*
 406  * LSM protocol operations (NetLabel LSM/kernel API)
 407  */
 408 int netlbl_enabled(void);
 409 int netlbl_sock_setattr(struct sock *sk,
 410                         u16 family,
 411                         const struct netlbl_lsm_secattr *secattr);
 412 void netlbl_sock_delattr(struct sock *sk);
 413 int netlbl_sock_getattr(struct sock *sk,
 414                         struct netlbl_lsm_secattr *secattr);
 415 int netlbl_conn_setattr(struct sock *sk,
 416                         struct sockaddr *addr,
 417                         const struct netlbl_lsm_secattr *secattr);
 418 int netlbl_req_setattr(struct request_sock *req,
 419                        const struct netlbl_lsm_secattr *secattr);
 420 void netlbl_req_delattr(struct request_sock *req);
 421 int netlbl_skbuff_setattr(struct sk_buff *skb,
 422                           u16 family,
 423                           const struct netlbl_lsm_secattr *secattr);
 424 int netlbl_skbuff_getattr(const struct sk_buff *skb,
 425                           u16 family,
 426                           struct netlbl_lsm_secattr *secattr);
 427 void netlbl_skbuff_err(struct sk_buff *skb, int error, int gateway);
 428
 429 /*
 430  * LSM label mapping cache operations
 431  */
 432 void netlbl_cache_invalidate(void);
 433 int netlbl_cache_add(const struct sk_buff *skb,
 434                      const struct netlbl_lsm_secattr *secattr);
 435
 436 /*
 437  * Protocol engine operations
 438  */
 439 struct audit_buffer *netlbl_audit_start(int type,
 440                                         struct netlbl_audit *audit_info);
 441 #else
 442 static inline int netlbl_cfg_map_del(const char *domain,
 443                                      u16 family,
 444                                      const void *addr,
 445                                      const void *mask,
 446                                      struct netlbl_audit *audit_info)
 447 {
 448         return -ENOSYS;
 449 }
 450 static inline int netlbl_cfg_unlbl_map_add(const char *domain,
 451                                            u16 family,
 452                                            void *addr,
 453                                            void *mask,
 454                                            struct netlbl_audit *audit_info)
 455 {
 456         return -ENOSYS;
 457 }
 458 static inline int netlbl_cfg_unlbl_static_add(struct net *net,
 459                                               const char *dev_name,
 460                                               const void *addr,
 461                                               const void *mask,
 462                                               u16 family,
 463                                               u32 secid,
 464                                               struct netlbl_audit *audit_info)
 465 {
 466         return -ENOSYS;
 467 }
 468 static inline int netlbl_cfg_unlbl_static_del(struct net *net,
 469                                               const char *dev_name,
 470                                               const void *addr,
 471                                               const void *mask,
 472                                               u16 family,
 473                                               struct netlbl_audit *audit_info)
 474 {
 475         return -ENOSYS;
 476 }
 477 static inline int netlbl_cfg_cipsov4_add(struct cipso_v4_doi *doi_def,
 478                                          struct netlbl_audit *audit_info)
 479 {
 480         return -ENOSYS;
 481 }
 482 static inline void netlbl_cfg_cipsov4_del(u32 doi,
 483                                           struct netlbl_audit *audit_info)
 484 {
 485         return;
 486 }
 487 static inline int netlbl_cfg_cipsov4_map_add(u32 doi,
 488                                              const char *domain,
 489                                              const struct in_addr *addr,
 490                                              const struct in_addr *mask,
 491                                              struct netlbl_audit *audit_info)
 492 {
 493         return -ENOSYS;
 494 }
 495 static inline int netlbl_secattr_catmap_walk(
 496                                       struct netlbl_lsm_secattr_catmap *catmap,
 497                                       u32 offset)
 498 {
 499         return -ENOENT;
 500 }
 501 static inline int netlbl_secattr_catmap_walk_rng(
 502                                       struct netlbl_lsm_secattr_catmap *catmap,
 503                                       u32 offset)
 504 {
 505         return -ENOENT;
 506 }
 507 static inline int netlbl_secattr_catmap_setbit(
 508                                       struct netlbl_lsm_secattr_catmap *catmap,
 509                                       u32 bit,
 510                                       gfp_t flags)
 511 {
 512         return 0;
 513 }
 514 static inline int netlbl_secattr_catmap_setrng(
 515                                       struct netlbl_lsm_secattr_catmap *catmap,
 516                                       u32 start,
 517                                       u32 end,
 518                                       gfp_t flags)
 519 {
 520         return 0;
 521 }
 522 static inline int netlbl_enabled(void)
 523 {
 524         return 0;
 525 }
 526 static inline int netlbl_sock_setattr(struct sock *sk,
 527                                       u16 family,
 528                                       const struct netlbl_lsm_secattr *secattr)
 529 {
 530         return -ENOSYS;
 531 }
 532 static inline void netlbl_sock_delattr(struct sock *sk)
 533 {
 534 }
 535 static inline int netlbl_sock_getattr(struct sock *sk,
 536                                       struct netlbl_lsm_secattr *secattr)
 537 {
 538         return -ENOSYS;
 539 }
 540 static inline int netlbl_conn_setattr(struct sock *sk,
 541                                       struct sockaddr *addr,
 542                                       const struct netlbl_lsm_secattr *secattr)
 543 {
 544         return -ENOSYS;
 545 }
 546 static inline int netlbl_req_setattr(struct request_sock *req,
 547                                      const struct netlbl_lsm_secattr *secattr)
 548 {
 549         return -ENOSYS;
 550 }
 551 static inline void netlbl_req_delattr(struct request_sock *req)
 552 {
 553         return;
 554 }
 555 static inline int netlbl_skbuff_setattr(struct sk_buff *skb,
 556                                       u16 family,
 557                                       const struct netlbl_lsm_secattr *secattr)
 558 {
 559         return -ENOSYS;
 560 }
 561 static inline int netlbl_skbuff_getattr(const struct sk_buff *skb,
 562                                         u16 family,
 563                                         struct netlbl_lsm_secattr *secattr)
 564 {
 565         return -ENOSYS;
 566 }
 567 static inline void netlbl_skbuff_err(struct sk_buff *skb,
 568                                      int error,
 569                                      int gateway)
 570 {
 571         return;
 572 }
 573 static inline void netlbl_cache_invalidate(void)
 574 {
 575         return;
 576 }
 577 static inline int netlbl_cache_add(const struct sk_buff *skb,
 578                                    const struct netlbl_lsm_secattr *secattr)
 579 {
 580         return 0;
 581 }
 582 static inline struct audit_buffer *netlbl_audit_start(int type,
 583                                                 struct netlbl_audit *audit_info)
 584 {
 585         return NULL;
 586 }
 587 #endif /* CONFIG_NETLABEL */
 588
 589 #endif /* _NETLABEL_H */