selinux-policy/libselinux/include/selinux/selinux.h

#ifndef _SELINUX_H_
#define _SELINUX_H_

#include <sys/types.h>
#include <stdarg.h>

#ifdef __cplusplus
extern "C"
{
#endif

/* Return 1 if we are running on a SELinux kernel, or 0 if not or -1 if we get an error. */
extern int is_selinux_enabled(void);
/* Return 1 if we are running on a SELinux MLS kernel, or 0 otherwise. */
extern int is_selinux_mls_enabled(void);

typedef char* security_context_t;

/* Free the memory allocated for a context by any of the below get* calls. */
extern void freecon(security_context_t con);

/* Free the memory allocated for a context array by security_compute_user. */
extern void freeconary(security_context_t *con);

/* Wrappers for the /proc/pid/attr API. */

/* Get current context, and set *con to refer to it.
   Caller must free via freecon. */
extern int getcon(security_context_t *con);
extern int getcon_raw(security_context_t *con);

/* Set the current security context to con.  
   Note that use of this function requires that the entire application
   be trusted to maintain any desired separation between the old and new 
   security contexts, unlike exec-based transitions performed via setexeccon.  
   When possible, decompose your application and use setexeccon()+execve() 
   instead. Note that the application may lose access to its open descriptors
   as a result of a setcon() unless policy allows it to use descriptors opened
   by the old context. */
extern int setcon(security_context_t con);
extern int setcon_raw(security_context_t con);

/* Get context of process identified by pid, and 
   set *con to refer to it.  Caller must free via freecon. */
extern int getpidcon(pid_t pid, security_context_t *con);
extern int getpidcon_raw(pid_t pid, security_context_t *con);

/* Get previous context (prior to last exec), and set *con to refer to it.
   Caller must free via freecon. */
extern int getprevcon(security_context_t *con);
extern int getprevcon_raw(security_context_t *con);

/* Get exec context, and set *con to refer to it.
   Sets *con to NULL if no exec context has been set, i.e. using default.
   If non-NULL, caller must free via freecon. */
extern int getexeccon(security_context_t *con);
extern int getexeccon_raw(security_context_t *con);

/* Set exec security context for the next execve. 
   Call with NULL if you want to reset to the default. */
extern int setexeccon(security_context_t con);
extern int setexeccon_raw(security_context_t con);

/* Get fscreate context, and set *con to refer to it.
   Sets *con to NULL if no fs create context has been set, i.e. using default.
   If non-NULL, caller must free via freecon. */
extern int getfscreatecon(security_context_t *con);
extern int getfscreatecon_raw(security_context_t *con);

/* Set the fscreate security context for subsequent file creations.
   Call with NULL if you want to reset to the default. */
extern int setfscreatecon(security_context_t context);
extern int setfscreatecon_raw(security_context_t context);


/* Wrappers for the xattr API. */

/* Get file context, and set *con to refer to it.
   Caller must free via freecon. */
extern int getfilecon(const char *path, security_context_t *con);
extern int getfilecon_raw(const char *path, security_context_t *con);
extern int lgetfilecon(const char *path, security_context_t *con);
extern int lgetfilecon_raw(const char *path, security_context_t *con);
extern int fgetfilecon(int fd, security_context_t *con);
extern int fgetfilecon_raw(int fd, security_context_t *con);

/* Set file context */
extern int setfilecon(const char *path, security_context_t con);
extern int setfilecon_raw(const char *path, security_context_t con);
extern int lsetfilecon(const char *path, security_context_t con);
extern int lsetfilecon_raw(const char *path, security_context_t con);
extern int fsetfilecon(int fd, security_context_t con);
extern int fsetfilecon_raw(int fd, security_context_t con);


/* Wrappers for the socket API */

/* Get context of peer socket, and set *con to refer to it.
   Caller must free via freecon. */
extern int getpeercon(int fd, security_context_t *con);
extern int getpeercon_raw(int fd, security_context_t *con);


/* Wrappers for the selinuxfs (policy) API. */

typedef unsigned int access_vector_t;
typedef unsigned short security_class_t;

struct av_decision {
	access_vector_t allowed;
	access_vector_t decided;
	access_vector_t auditallow;
	access_vector_t auditdeny;
	unsigned int seqno;
};

/* Compute an access decision. */
extern int security_compute_av(security_context_t scon,
			       security_context_t tcon,
			       security_class_t tclass,
			       access_vector_t requested,
			       struct av_decision *avd);
extern int security_compute_av_raw(security_context_t scon,
                                   security_context_t tcon,
                                   security_class_t tclass,
                                   access_vector_t requested,
                                   struct av_decision *avd);

/* Compute a labeling decision and set *newcon to refer to it.
   Caller must free via freecon. */
extern int security_compute_create(security_context_t scon,
				   security_context_t tcon,
				   security_class_t tclass,
				   security_context_t *newcon);
extern int security_compute_create_raw(security_context_t scon,
                                       security_context_t tcon,
                                       security_class_t tclass,
                                       security_context_t *newcon);

/* Compute a relabeling decision and set *newcon to refer to it.
   Caller must free via freecon. */
extern int security_compute_relabel(security_context_t scon,
				    security_context_t tcon,
				    security_class_t tclass,
				    security_context_t *newcon);
extern int security_compute_relabel_raw(security_context_t scon,
                                        security_context_t tcon,
                                        security_class_t tclass,
                                        security_context_t *newcon);

/* Compute a polyinstantiation member decision and set *newcon to refer to it.
   Caller must free via freecon. */
extern int security_compute_member(security_context_t scon,
				   security_context_t tcon,
				   security_class_t tclass,
				   security_context_t *newcon);
extern int security_compute_member_raw(security_context_t scon,
                                       security_context_t tcon,
                                       security_class_t tclass,
                                       security_context_t *newcon);

/* Compute the set of reachable user contexts and set *con to refer to 
   the NULL-terminated array of contexts.  Caller must free via freeconary. */
extern int security_compute_user(security_context_t scon,
				 const char *username,
				 security_context_t **con);
extern int security_compute_user_raw(security_context_t scon,
                                     const char *username,
                                     security_context_t **con);

/* Load a policy configuration. */
extern int security_load_policy(void *data, size_t len);

/*
 * Make a policy image and load it.
 * This function provides a higher level interface for loading policy
 * than security_load_policy, internally determining the right policy
 * version, locating and opening the policy file, mapping it into memory,
 * manipulating it as needed for current boolean settings and/or local 
 * definitions, and then calling security_load_policy to load it.
 *
 * 'preservebools' is a boolean flag indicating whether current 
 * policy boolean values should be preserved into the new policy (if 1) 
 * or reset to the saved policy settings (if 0).  The former case is the
 * default for policy reloads, while the latter case is an option for policy
 * reloads but is primarily for the initial policy load.
 */
extern int selinux_mkload_policy(int preservebools);


/* 
 * Perform the initial policy load.
 * This function determines the desired enforcing mode, sets the
 * the *enforce argument accordingly for the caller to use, sets the 
 * SELinux kernel enforcing status to match it, and loads the policy.
 * It also internally handles the initial selinuxfs mount required to
 * perform these actions.
 *
 * The function returns 0 if everything including the policy load succeeds.
 * In this case, init is expected to re-exec itself in order to transition
 * to the proper security context.
 * Otherwise, the function returns -1, and init must check *enforce to
 * determine how to proceed.  If enforcing (*enforce > 0), then init should
 * halt the system.  Otherwise, init may proceed normally without a re-exec.
 */
extern int selinux_init_load_policy(int *enforce);

/* Translate boolean strict to name value pair. */
typedef struct {
	char *name;
	int value; 
} SELboolean;
	/* save a list of booleans in a single transaction.  */
extern int security_set_boolean_list(size_t boolcnt, 
				     SELboolean *boollist, 
				     int permanent);

/* Load policy boolean settings.
   Path may be NULL, in which case the booleans are loaded from
   the active policy boolean configuration file. */
extern int security_load_booleans(char *path);

/* Check the validity of a security context. */
extern int security_check_context(security_context_t con);
extern int security_check_context_raw(security_context_t con);

/* Get the enforce flag value. */
extern int security_getenforce(void);

/* Set the enforce flag value. */
extern int security_setenforce(int value);

/* Disable SELinux at runtime (must be done prior to initial policy load). */
extern int security_disable(void);

/* Get the policy version number. */
extern int security_policyvers(void);

/* Get the boolean names */
extern int security_get_boolean_names(char ***names, int *len);

/* Get the pending value for the boolean */
extern int security_get_boolean_pending(const char *name);

/* Get the active value for the boolean */
extern int security_get_boolean_active(const char *name);

/* Set the pending value for the boolean */
extern int security_set_boolean(const char *name, int value);

/* Commit the pending values for the booleans */
extern int security_commit_booleans(void);

/* Common helpers */

/* Return the security class value for a given class name. */
extern security_class_t string_to_security_class(const char *name);

/* Return an access vector for a given class and permission name. */
extern access_vector_t string_to_av_perm(security_class_t tclass, const char *name);

/* Display an access vector in a string representation. */
extern void print_access_vector(security_class_t tclass, access_vector_t av);

/* Set the function used by matchpathcon_init when displaying
   errors about the file_contexts configuration.  If not set,
   then this defaults to fprintf(stderr, fmt, ...). */
extern void set_matchpathcon_printf(void (*f)(const char *fmt, ...));

/* Set the function used by matchpathcon_init when checking the
   validity of a context in the file contexts configuration.  If not set,
   then this defaults to a test based on security_check_context().  
   The function is also responsible for reporting any such error, and
   may include the 'path' and 'lineno' in such error messages. */
extern void set_matchpathcon_invalidcon(int (*f)(const char *path, 
						 unsigned lineno, 
						 char *context));

/* Set flags controlling operation of matchpathcon_init or matchpathcon. */
#define MATCHPATHCON_BASEONLY 1 /* Only process the base file_contexts file. */
extern void set_matchpathcon_flags(unsigned int flags);

/* Load the file contexts configuration specified by 'path'
   into memory for use by subsequent matchpathcon calls.  
   If 'path' is NULL, then load the active file contexts configuration,
   i.e. the path returned by selinux_file_context_path().
   Unless the MATCHPATHCON_BASEONLY flag has been set, this
   function also checks for a 'path'.homedirs file and 
   a 'path'.local file and loads additional specifications 
   from them if present. */
extern int matchpathcon_init(const char *path);

/* Match the specified pathname and mode against the file contexts
   configuration and set *con to refer to the resulting context.
   'mode' can be 0 to disable mode matching.
   Caller must free via freecon.
   If matchpathcon_init has not already been called, then this function
   will call it upon its first invocation with a NULL path. */
extern int matchpathcon(const char *path,
			mode_t mode,
			security_context_t *con);

/* Same as above, but return a specification index for 
   later use in a matchpathcon_filespec_add() call - see below. */
extern int matchpathcon_index(const char *path,
			      mode_t mode,
			      security_context_t *con);

/* Maintain an association between an inode and a specification index,
   and check whether a conflicting specification is already associated
   with the same inode (e.g. due to multiple hard links).  If so, then
   use the latter of the two specifications based on their order in the 
   file contexts configuration.  Return the used specification index. */
extern int matchpathcon_filespec_add(ino_t ino, int specind, const char *file);

/* Destroy any inode associations that have been added, e.g. to restart
   for a new filesystem. */
extern void matchpathcon_filespec_destroy(void);

/* Display statistics on the hash table usage for the associations. */
extern void matchpathcon_filespec_eval(void);

/* Check to see whether any specifications had no matches and report them.
   The 'str' is used as a prefix for any warning messages. */
extern void matchpathcon_checkmatches(char *str);

/* Match the specified media and against the media contexts 
   configuration and set *con to refer to the resulting context.
   Caller must free con via freecon. */
extern int matchmediacon(const char *media,
		 security_context_t *con);

/*
  selinux_getenforcemode reads the /etc/selinux/config file and determines 
  whether the machine should be started in enforcing (1), permissive (0) or 
  disabled (-1) mode.
 */
extern int selinux_getenforcemode(int *enforce);

/*
  selinux_policy_root reads the /etc/selinux/config file and returns 
  the directory path under which the compiled policy file and context 
  configuration files exist.
 */
extern const char *selinux_policy_root(void);

/* These functions return the paths to specific files under the 
   policy root directory. */
extern const char *selinux_binary_policy_path(void);
extern const char *selinux_failsafe_context_path(void);
extern const char *selinux_removable_context_path(void);
extern const char *selinux_default_context_path(void);
extern const char *selinux_user_contexts_path(void);
extern const char *selinux_file_context_path(void);
extern const char *selinux_media_context_path(void);
extern const char *selinux_contexts_path(void);
extern const char *selinux_booleans_path(void);
extern const char *selinux_customizable_types_path(void);
extern const char *selinux_users_path(void);
extern const char *selinux_usersconf_path(void);

/* Check a permission in the passwd class.
   Return 0 if granted or -1 otherwise. */
extern int selinux_check_passwd_access(access_vector_t requested);
extern int checkPasswdAccess(access_vector_t requested);

/* Set the path to the selinuxfs mount point explicitly.
   Normally, this is determined automatically during libselinux 
   initialization, but this is not always possible, e.g. for /sbin/init
   which performs the initial mount of selinuxfs. */
void set_selinuxmnt(char *mnt);

/* Execute a helper for rpm in an appropriate security context. */
extern int rpm_execcon(unsigned int verified, 
		       const char *filename, 
		       char *const argv[], char *const envp[]);

/* Returns whether a file context is customizable, and should not 
   be relabeled . */
extern int is_context_customizable (security_context_t scontext);

/* Perform context translation between the human-readable format
   ("translated") and the internal system format ("raw"). 
   Caller must free the resulting context via freecon.  
   Returns -1 upon an error or 0 otherwise.
   If passed NULL, sets the returned context to NULL and returns 0. */
extern int selinux_trans_to_raw_context(security_context_t trans, 
					security_context_t *rawp);
extern int selinux_raw_to_trans_context(security_context_t raw, 
					security_context_t *transp);

/* Get the SELinux username and level to use for a given Linux username. 
   These values may then be passed into the get_ordered_context_list*
   and get_default_context* functions to obtain a context for the user.
   Returns 0 on success or -1 otherwise.
   Caller must free the returned strings via free. */
extern int getseuserbyname(const char *linuxuser, char **seuser, char **level);

#ifdef __cplusplus
}
#endif

#endif