/*
   * NetLabel System
   *
   * The NetLabel system manages static and dynamic label mappings for network
   * protocols such as CIPSO and RIPSO.
   *
   * Author: Paul Moore <paul@paul-moore.com>
   *
   */
  
  /*
   * (c) Copyright Hewlett-Packard Development Company, L.P., 2006, 2008
   *
   * This program is free software;  you can redistribute it and/or modify
   * it under the terms of the GNU General Public License as published by
   * the Free Software Foundation; either version 2 of the License, or
   * (at your option) any later version.
   *
   * This program is distributed in the hope that it will be useful,
   * but WITHOUT ANY WARRANTY;  without even the implied warranty of
   * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See
   * the GNU General Public License for more details.
   *
   * You should have received a copy of the GNU General Public License
   * along with this program;  if not, see <http://www.gnu.org/licenses/>.
   *
   */
  
  #ifndef _NETLABEL_H
  #define _NETLABEL_H
  
  #include <linux/types.h>
  #include <linux/slab.h>
  #include <linux/net.h>
  #include <linux/skbuff.h>
  #include <linux/in.h>
  #include <linux/in6.h>
  #include <net/netlink.h>
  #include <net/request_sock.h>
  #include <linux/atomic.h>
  
  struct cipso_v4_doi;
  
  /*
   * NetLabel - A management interface for maintaining network packet label
   *            mapping tables for explicit packet labling protocols.
   *
   * Network protocols such as CIPSO and RIPSO require a label translation layer
   * to convert the label on the packet into something meaningful on the host
   * machine.  In the current Linux implementation these mapping tables live
   * inside the kernel; NetLabel provides a mechanism for user space applications
   * to manage these mapping tables.
   *
   * NetLabel makes use of the Generic NETLINK mechanism as a transport layer to
   * send messages between kernel and user space.  The general format of a
   * NetLabel message is shown below:
   *
   *  +-----------------+-------------------+--------- --- -- -
   *  | struct nlmsghdr | struct genlmsghdr | payload
   *  +-----------------+-------------------+--------- --- -- -
   *
   * The 'nlmsghdr' and 'genlmsghdr' structs should be dealt with like normal.
   * The payload is dependent on the subsystem specified in the
   * 'nlmsghdr->nlmsg_type' and should be defined below, supporting functions
   * should be defined in the corresponding net/netlabel/netlabel_<subsys>.h|c
   * file.  All of the fields in the NetLabel payload are NETLINK attributes, see
   * the include/net/netlink.h file for more information on NETLINK attributes.
   *
   */
  
  /*
   * NetLabel NETLINK protocol
   */
  
  /* NetLabel NETLINK protocol version
   *  1: initial version
   *  2: added static labels for unlabeled connections
   *  3: network selectors added to the NetLabel/LSM domain mapping and the
   *     CIPSO_V4_MAP_LOCAL CIPSO mapping was added
   */
  #define NETLBL_PROTO_VERSION            3
  
  /* NetLabel NETLINK types/families */
  #define NETLBL_NLTYPE_NONE              0
  #define NETLBL_NLTYPE_MGMT              1
  #define NETLBL_NLTYPE_MGMT_NAME         "NLBL_MGMT"
  #define NETLBL_NLTYPE_RIPSO             2
  #define NETLBL_NLTYPE_RIPSO_NAME        "NLBL_RIPSO"
  #define NETLBL_NLTYPE_CIPSOV4           3
  #define NETLBL_NLTYPE_CIPSOV4_NAME      "NLBL_CIPSOv4"
  #define NETLBL_NLTYPE_CIPSOV6           4
  #define NETLBL_NLTYPE_CIPSOV6_NAME      "NLBL_CIPSOv6"
  #define NETLBL_NLTYPE_UNLABELED         5
  #define NETLBL_NLTYPE_UNLABELED_NAME    "NLBL_UNLBL"
  #define NETLBL_NLTYPE_ADDRSELECT        6
  #define NETLBL_NLTYPE_ADDRSELECT_NAME   "NLBL_ADRSEL"
  
  /*
   * NetLabel - Kernel API for accessing the network packet label mappings.
   *
   * The following functions are provided for use by other kernel modules,
   * specifically kernel LSM modules, to provide a consistent, transparent API
   * for dealing with explicit packet labeling protocols such as CIPSO and
   * RIPSO.  The functions defined here are implemented in the
   * net/netlabel/netlabel_kapi.c file.
   *
   */
  
  /* NetLabel audit information */
  struct netlbl_audit {
  	u32 secid;
  	kuid_t loginuid;
  	unsigned int sessionid;
  };
  
  /*
   * LSM security attributes
   */
  
  /**
   * struct netlbl_lsm_cache - NetLabel LSM security attribute cache
   * @refcount: atomic reference counter
   * @free: LSM supplied function to free the cache data
   * @data: LSM supplied cache data
   *
   * Description:
   * This structure is provided for LSMs which wish to make use of the NetLabel
   * caching mechanism to store LSM specific data/attributes in the NetLabel
   * cache.  If the LSM has to perform a lot of translation from the NetLabel
   * security attributes into it's own internal representation then the cache
   * mechanism can provide a way to eliminate some or all of that translation
   * overhead on a cache hit.
   *
   */
  struct netlbl_lsm_cache {
  	atomic_t refcount;
  	void (*free) (const void *data);
  	void *data;
  };
  
  /**
   * struct netlbl_lsm_secattr_catmap - NetLabel LSM secattr category bitmap
   * @startbit: the value of the lowest order bit in the bitmap
   * @bitmap: the category bitmap
   * @next: pointer to the next bitmap "node" or NULL
   *
   * Description:
   * This structure is used to represent category bitmaps.  Due to the large
   * number of categories supported by most labeling protocols it is not
   * practical to transfer a full bitmap internally so NetLabel adopts a sparse
   * bitmap structure modeled after SELinux's ebitmap structure.
   * The catmap bitmap field MUST be a power of two in length and large
   * enough to hold at least 240 bits.  Special care (i.e. check the code!)
   * should be used when changing these values as the LSM implementation
   * probably has functions which rely on the sizes of these types to speed
   * processing.
   *
   */
  #define NETLBL_CATMAP_MAPTYPE           u64
  #define NETLBL_CATMAP_MAPCNT            4
  #define NETLBL_CATMAP_MAPSIZE           (sizeof(NETLBL_CATMAP_MAPTYPE) * 8)
  #define NETLBL_CATMAP_SIZE              (NETLBL_CATMAP_MAPSIZE * \
  					 NETLBL_CATMAP_MAPCNT)
  #define NETLBL_CATMAP_BIT               (NETLBL_CATMAP_MAPTYPE)0x01
  struct netlbl_lsm_secattr_catmap {
  	u32 startbit;
  	NETLBL_CATMAP_MAPTYPE bitmap[NETLBL_CATMAP_MAPCNT];
  	struct netlbl_lsm_secattr_catmap *next;
  };
  
  /**
   * struct netlbl_lsm_secattr - NetLabel LSM security attributes
   * @flags: indicate structure attributes, see NETLBL_SECATTR_*
   * @type: indicate the NLTYPE of the attributes
   * @domain: the NetLabel LSM domain
   * @cache: NetLabel LSM specific cache
   * @attr.mls: MLS sensitivity label
   * @attr.mls.cat: MLS category bitmap
   * @attr.mls.lvl: MLS sensitivity level
   * @attr.secid: LSM specific secid token
   *
   * Description:
   * This structure is used to pass security attributes between NetLabel and the
   * LSM modules.  The flags field is used to specify which fields within the
   * struct are valid and valid values can be created by bitwise OR'ing the
   * NETLBL_SECATTR_* defines.  The domain field is typically set by the LSM to
   * specify domain specific configuration settings and is not usually used by
   * NetLabel itself when returning security attributes to the LSM.
   *
   */
  struct netlbl_lsm_secattr {
  	u32 flags;
  	/* bitmap values for 'flags' */
  #define NETLBL_SECATTR_NONE             0x00000000
  #define NETLBL_SECATTR_DOMAIN           0x00000001
  #define NETLBL_SECATTR_DOMAIN_CPY       (NETLBL_SECATTR_DOMAIN | \
  					 NETLBL_SECATTR_FREE_DOMAIN)
  #define NETLBL_SECATTR_CACHE            0x00000002
  #define NETLBL_SECATTR_MLS_LVL          0x00000004
  #define NETLBL_SECATTR_MLS_CAT          0x00000008
  #define NETLBL_SECATTR_SECID            0x00000010
  	/* bitmap meta-values for 'flags' */
  #define NETLBL_SECATTR_FREE_DOMAIN      0x01000000
  #define NETLBL_SECATTR_CACHEABLE        (NETLBL_SECATTR_MLS_LVL | \
  					 NETLBL_SECATTR_MLS_CAT | \
  					 NETLBL_SECATTR_SECID)
  	u32 type;
  	char *domain;
  	struct netlbl_lsm_cache *cache;
  	struct {
  		struct {
  			struct netlbl_lsm_secattr_catmap *cat;
  			u32 lvl;
  		} mls;
  		u32 secid;
  	} attr;
  };
  
  /*
   * LSM security attribute operations (inline)
   */
  
  /**
   * netlbl_secattr_cache_alloc - Allocate and initialize a secattr cache
   * @flags: the memory allocation flags
   *
   * Description:
   * Allocate and initialize a netlbl_lsm_cache structure.  Returns a pointer
   * on success, NULL on failure.
   *
   */
  static inline struct netlbl_lsm_cache *netlbl_secattr_cache_alloc(gfp_t flags)
  {
  	struct netlbl_lsm_cache *cache;
  
  	cache = kzalloc(sizeof(*cache), flags);
  	if (cache)
  		atomic_set(&cache->refcount, 1);
  	return cache;
  }
  
  /**
   * netlbl_secattr_cache_free - Frees a netlbl_lsm_cache struct
   * @cache: the struct to free
   *
   * Description:
   * Frees @secattr including all of the internal buffers.
   *
   */
  static inline void netlbl_secattr_cache_free(struct netlbl_lsm_cache *cache)
  {
  	if (!atomic_dec_and_test(&cache->refcount))
  		return;
  
  	if (cache->free)
  		cache->free(cache->data);
  	kfree(cache);
  }
  
  /**
   * netlbl_secattr_catmap_alloc - Allocate a LSM secattr catmap
   * @flags: memory allocation flags
   *
   * Description:
   * Allocate memory for a LSM secattr catmap, returns a pointer on success, NULL
   * on failure.
   *
   */
  static inline struct netlbl_lsm_secattr_catmap *netlbl_secattr_catmap_alloc(
  	                                                           gfp_t flags)
  {
  	return kzalloc(sizeof(struct netlbl_lsm_secattr_catmap), flags);
  }
  
  /**
   * netlbl_secattr_catmap_free - Free a LSM secattr catmap
   * @catmap: the category bitmap
   *
   * Description:
   * Free a LSM secattr catmap.
   *
   */
  static inline void netlbl_secattr_catmap_free(
  	                              struct netlbl_lsm_secattr_catmap *catmap)
  {
  	struct netlbl_lsm_secattr_catmap *iter;
  
  	do {
  		iter = catmap;
  		catmap = catmap->next;
  		kfree(iter);
  	} while (catmap);
  }
  
  /**
   * netlbl_secattr_init - Initialize a netlbl_lsm_secattr struct
   * @secattr: the struct to initialize
   *
   * Description:
   * Initialize an already allocated netlbl_lsm_secattr struct.
   *
   */
  static inline void netlbl_secattr_init(struct netlbl_lsm_secattr *secattr)
  {
  	memset(secattr, 0, sizeof(*secattr));
  }
  
  /**
   * netlbl_secattr_destroy - Clears a netlbl_lsm_secattr struct
   * @secattr: the struct to clear
   *
   * Description:
   * Destroys the @secattr struct, including freeing all of the internal buffers.
   * The struct must be reset with a call to netlbl_secattr_init() before reuse.
   *
   */
  static inline void netlbl_secattr_destroy(struct netlbl_lsm_secattr *secattr)
  {
  	if (secattr->flags & NETLBL_SECATTR_FREE_DOMAIN)
  		kfree(secattr->domain);
  	if (secattr->flags & NETLBL_SECATTR_CACHE)
  		netlbl_secattr_cache_free(secattr->cache);
  	if (secattr->flags & NETLBL_SECATTR_MLS_CAT)
  		netlbl_secattr_catmap_free(secattr->attr.mls.cat);
  }
  
  /**
   * netlbl_secattr_alloc - Allocate and initialize a netlbl_lsm_secattr struct
   * @flags: the memory allocation flags
   *
   * Description:
   * Allocate and initialize a netlbl_lsm_secattr struct.  Returns a valid
   * pointer on success, or NULL on failure.
   *
   */
  static inline struct netlbl_lsm_secattr *netlbl_secattr_alloc(gfp_t flags)
  {
  	return kzalloc(sizeof(struct netlbl_lsm_secattr), flags);
  }
  
  /**
   * netlbl_secattr_free - Frees a netlbl_lsm_secattr struct
   * @secattr: the struct to free
   *
   * Description:
   * Frees @secattr including all of the internal buffers.
   *
   */
  static inline void netlbl_secattr_free(struct netlbl_lsm_secattr *secattr)
  {
  	netlbl_secattr_destroy(secattr);
  	kfree(secattr);
  }
  
  #ifdef CONFIG_NETLABEL
  /*
   * LSM configuration operations
   */
  int netlbl_cfg_map_del(const char *domain,
  		       u16 family,
  		       const void *addr,
  		       const void *mask,
  		       struct netlbl_audit *audit_info);
  int netlbl_cfg_unlbl_map_add(const char *domain,
  			     u16 family,
  			     const void *addr,
  			     const void *mask,
  			     struct netlbl_audit *audit_info);
  int netlbl_cfg_unlbl_static_add(struct net *net,
  				const char *dev_name,
  				const void *addr,
  				const void *mask,
  				u16 family,
  				u32 secid,
  				struct netlbl_audit *audit_info);
  int netlbl_cfg_unlbl_static_del(struct net *net,
  				const char *dev_name,
  				const void *addr,
  				const void *mask,
  				u16 family,
  				struct netlbl_audit *audit_info);
  int netlbl_cfg_cipsov4_add(struct cipso_v4_doi *doi_def,
  			   struct netlbl_audit *audit_info);
  void netlbl_cfg_cipsov4_del(u32 doi, struct netlbl_audit *audit_info);
  int netlbl_cfg_cipsov4_map_add(u32 doi,
  			       const char *domain,
  			       const struct in_addr *addr,
  			       const struct in_addr *mask,
  			       struct netlbl_audit *audit_info);
  /*
   * LSM security attribute operations
   */
  int netlbl_secattr_catmap_walk(struct netlbl_lsm_secattr_catmap *catmap,
  			       u32 offset);
  int netlbl_secattr_catmap_walk_rng(struct netlbl_lsm_secattr_catmap *catmap,
  				   u32 offset);
  int netlbl_secattr_catmap_setbit(struct netlbl_lsm_secattr_catmap *catmap,
  				 u32 bit,
  				 gfp_t flags);
  int netlbl_secattr_catmap_setrng(struct netlbl_lsm_secattr_catmap *catmap,
  				 u32 start,
  				 u32 end,
  				 gfp_t flags);
  
  /*
   * LSM protocol operations (NetLabel LSM/kernel API)
   */
  int netlbl_enabled(void);
  int netlbl_sock_setattr(struct sock *sk,
  			u16 family,
  			const struct netlbl_lsm_secattr *secattr);
  void netlbl_sock_delattr(struct sock *sk);
  int netlbl_sock_getattr(struct sock *sk,
  			struct netlbl_lsm_secattr *secattr);
  int netlbl_conn_setattr(struct sock *sk,
  			struct sockaddr *addr,
  			const struct netlbl_lsm_secattr *secattr);
  int netlbl_req_setattr(struct request_sock *req,
  		       const struct netlbl_lsm_secattr *secattr);
  void netlbl_req_delattr(struct request_sock *req);
  int netlbl_skbuff_setattr(struct sk_buff *skb,
  			  u16 family,
  			  const struct netlbl_lsm_secattr *secattr);
  int netlbl_skbuff_getattr(const struct sk_buff *skb,
  			  u16 family,
  			  struct netlbl_lsm_secattr *secattr);
  void netlbl_skbuff_err(struct sk_buff *skb, int error, int gateway);
  
  /*
   * LSM label mapping cache operations
   */
  void netlbl_cache_invalidate(void);
  int netlbl_cache_add(const struct sk_buff *skb,
  		     const struct netlbl_lsm_secattr *secattr);
  
  /*
   * Protocol engine operations
   */
  struct audit_buffer *netlbl_audit_start(int type,
  					struct netlbl_audit *audit_info);
  #else
  static inline int netlbl_cfg_map_del(const char *domain,
  				     u16 family,
  				     const void *addr,
  				     const void *mask,
  				     struct netlbl_audit *audit_info)
  {
  	return -ENOSYS;
  }
  static inline int netlbl_cfg_unlbl_map_add(const char *domain,
  					   u16 family,
  					   void *addr,
  					   void *mask,
  					   struct netlbl_audit *audit_info)
  {
  	return -ENOSYS;
  }
  static inline int netlbl_cfg_unlbl_static_add(struct net *net,
  					      const char *dev_name,
  					      const void *addr,
  					      const void *mask,
  					      u16 family,
  					      u32 secid,
  					      struct netlbl_audit *audit_info)
  {
  	return -ENOSYS;
  }
  static inline int netlbl_cfg_unlbl_static_del(struct net *net,
  					      const char *dev_name,
  					      const void *addr,
  					      const void *mask,
  					      u16 family,
  					      struct netlbl_audit *audit_info)
  {
  	return -ENOSYS;
  }
  static inline int netlbl_cfg_cipsov4_add(struct cipso_v4_doi *doi_def,
  					 struct netlbl_audit *audit_info)
  {
  	return -ENOSYS;
  }
  static inline void netlbl_cfg_cipsov4_del(u32 doi,
  					  struct netlbl_audit *audit_info)
  {
  	return;
  }
  static inline int netlbl_cfg_cipsov4_map_add(u32 doi,
  					     const char *domain,
  					     const struct in_addr *addr,
  					     const struct in_addr *mask,
  					     struct netlbl_audit *audit_info)
  {
  	return -ENOSYS;
  }
  static inline int netlbl_secattr_catmap_walk(
  	                              struct netlbl_lsm_secattr_catmap *catmap,
  				      u32 offset)
  {
  	return -ENOENT;
  }
  static inline int netlbl_secattr_catmap_walk_rng(
  				      struct netlbl_lsm_secattr_catmap *catmap,
  				      u32 offset)
  {
  	return -ENOENT;
  }
  static inline int netlbl_secattr_catmap_setbit(
  	                              struct netlbl_lsm_secattr_catmap *catmap,
  				      u32 bit,
  				      gfp_t flags)
  {
  	return 0;
  }
  static inline int netlbl_secattr_catmap_setrng(
  	                              struct netlbl_lsm_secattr_catmap *catmap,
  				      u32 start,
  				      u32 end,
  				      gfp_t flags)
  {
  	return 0;
  }
  static inline int netlbl_enabled(void)
  {
  	return 0;
  }
  static inline int netlbl_sock_setattr(struct sock *sk,
  				      u16 family,
  				      const struct netlbl_lsm_secattr *secattr)
  {
  	return -ENOSYS;
  }
  static inline void netlbl_sock_delattr(struct sock *sk)
  {
  }
  static inline int netlbl_sock_getattr(struct sock *sk,
  				      struct netlbl_lsm_secattr *secattr)
  {
  	return -ENOSYS;
  }
  static inline int netlbl_conn_setattr(struct sock *sk,
  				      struct sockaddr *addr,
  				      const struct netlbl_lsm_secattr *secattr)
  {
  	return -ENOSYS;
  }
  static inline int netlbl_req_setattr(struct request_sock *req,
  				     const struct netlbl_lsm_secattr *secattr)
  {
  	return -ENOSYS;
  }
  static inline void netlbl_req_delattr(struct request_sock *req)
  {
  	return;
  }
  static inline int netlbl_skbuff_setattr(struct sk_buff *skb,
  				      u16 family,
  				      const struct netlbl_lsm_secattr *secattr)
  {
  	return -ENOSYS;
  }
  static inline int netlbl_skbuff_getattr(const struct sk_buff *skb,
  					u16 family,
  					struct netlbl_lsm_secattr *secattr)
  {
  	return -ENOSYS;
  }
  static inline void netlbl_skbuff_err(struct sk_buff *skb,
  				     int error,
  				     int gateway)
  {
  	return;
  }
  static inline void netlbl_cache_invalidate(void)
  {
  	return;
  }
  static inline int netlbl_cache_add(const struct sk_buff *skb,
  				   const struct netlbl_lsm_secattr *secattr)
  {
  	return 0;
  }
  static inline struct audit_buffer *netlbl_audit_start(int type,
  						struct netlbl_audit *audit_info)
  {
  	return NULL;
  }
  #endif /* CONFIG_NETLABEL */
  
  #endif /* _NETLABEL_H */