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      1 /*
      2  * Labeling interface for userspace object managers and others.
      3  *
      4  * Author : Eamon Walsh <ewalsh (at) tycho.nsa.gov>
      5  */
      6 #ifndef _SELABEL_H_
      7 #define _SELABEL_H_
      8 
      9 #include <stdbool.h>
     10 #include <sys/types.h>
     11 #include <selinux/selinux.h>
     12 
     13 #ifdef __cplusplus
     14 extern "C" {
     15 #endif
     16 
     17 /*
     18  * Opaque type used for all label handles.
     19  */
     20 
     21 struct selabel_handle;
     22 
     23 /*
     24  * Available backends.
     25  */
     26 
     27 /* file contexts */
     28 #define SELABEL_CTX_FILE	0
     29 /* media contexts */
     30 #define SELABEL_CTX_MEDIA	1
     31 /* x contexts */
     32 #define SELABEL_CTX_X		2
     33 /* db objects */
     34 #define SELABEL_CTX_DB		3
     35 /* Android property service contexts */
     36 #define SELABEL_CTX_ANDROID_PROP 4
     37 /* Android service contexts */
     38 #define SELABEL_CTX_ANDROID_SERVICE 5
     39 
     40 /*
     41  * Available options
     42  */
     43 
     44 /* no-op option, useful for unused slots in an array of options */
     45 #define SELABEL_OPT_UNUSED	0
     46 /* validate contexts before returning them (boolean value) */
     47 #define SELABEL_OPT_VALIDATE	1
     48 /* don't use local customizations to backend data (boolean value) */
     49 #define SELABEL_OPT_BASEONLY	2
     50 /* specify an alternate path to use when loading backend data */
     51 #define SELABEL_OPT_PATH	3
     52 /* select a subset of the search space as an optimization (file backend) */
     53 #define SELABEL_OPT_SUBSET	4
     54 /* require a hash calculation on spec files */
     55 #define SELABEL_OPT_DIGEST	5
     56 /* total number of options */
     57 #define SELABEL_NOPT		6
     58 
     59 /*
     60  * Label operations
     61  */
     62 
     63 /**
     64  * selabel_open - Create a labeling handle.
     65  * @backend: one of the constants specifying a supported labeling backend.
     66  * @opts: array of selabel_opt structures specifying label options or NULL.
     67  * @nopts: number of elements in opts array or zero for no options.
     68  *
     69  * Open a labeling backend for use.  The available backend identifiers are
     70  * listed above.  Options may be provided via the opts parameter; available
     71  * options are listed above.  Not all options may be supported by every
     72  * backend.  Return value is the created handle on success or NULL with
     73  * @errno set on failure.
     74  */
     75 struct selabel_handle *selabel_open(unsigned int backend,
     76 				    const struct selinux_opt *opts,
     77 				    unsigned nopts);
     78 
     79 /**
     80  * selabel_close - Close a labeling handle.
     81  * @handle: specifies handle to close
     82  *
     83  * Destroy the specified handle, closing files, freeing allocated memory,
     84  * etc.  The handle may not be further used after it has been closed.
     85  */
     86 void selabel_close(struct selabel_handle *handle);
     87 
     88 /**
     89  * selabel_lookup - Perform labeling lookup operation.
     90  * @handle: specifies backend instance to query
     91  * @con: returns the appropriate context with which to label the object
     92  * @key: string input to lookup operation
     93  * @type: numeric input to the lookup operation
     94  *
     95  * Perform a labeling lookup operation.  Return %0 on success, -%1 with
     96  * @errno set on failure.  The key and type arguments are the inputs to the
     97  * lookup operation; appropriate values are dictated by the backend in use.
     98  * The result is returned in the memory pointed to by @con and must be freed
     99  * by the user with freecon().
    100  */
    101 int selabel_lookup(struct selabel_handle *handle, char **con,
    102 		   const char *key, int type);
    103 int selabel_lookup_raw(struct selabel_handle *handle, char **con,
    104 		       const char *key, int type);
    105 
    106 bool selabel_partial_match(struct selabel_handle *handle, const char *key);
    107 
    108 int selabel_lookup_best_match(struct selabel_handle *rec, char **con,
    109 			      const char *key, const char **aliases, int type);
    110 int selabel_lookup_best_match_raw(struct selabel_handle *rec, char **con,
    111 			      const char *key, const char **aliases, int type);
    112 
    113 /**
    114  * selabel_digest - Retrieve the SHA1 digest and the list of specfiles used to
    115  *		    generate the digest. The SELABEL_OPT_DIGEST option must
    116  *		    be set in selabel_open() to initiate the digest generation.
    117  * @handle: specifies backend instance to query
    118  * @digest: returns a pointer to the SHA1 digest.
    119  * @digest_len: returns length of digest in bytes.
    120  * @specfiles: a list of specfiles used in the SHA1 digest generation.
    121  *	       The list is NULL terminated and will hold @num_specfiles entries.
    122  * @num_specfiles: number of specfiles in the list.
    123  *
    124  * Return %0 on success, -%1 with @errno set on failure.
    125  */
    126 int selabel_digest(struct selabel_handle *rec,
    127 			    unsigned char **digest, size_t *digest_len,
    128 			    char ***specfiles, size_t *num_specfiles);
    129 
    130 enum selabel_cmp_result {
    131 	SELABEL_SUBSET,
    132 	SELABEL_EQUAL,
    133 	SELABEL_SUPERSET,
    134 	SELABEL_INCOMPARABLE
    135 };
    136 
    137 /**
    138  * selabel_cmp - Compare two label configurations.
    139  * @h1: handle for the first label configuration
    140  * @h2: handle for the first label configuration
    141  *
    142  * Compare two label configurations.
    143  * Return %SELABEL_SUBSET if @h1 is a subset of @h2, %SELABEL_EQUAL
    144  * if @h1 is identical to @h2, %SELABEL_SUPERSET if @h1 is a superset
    145  * of @h2, and %SELABEL_INCOMPARABLE if @h1 and @h2 are incomparable.
    146  */
    147 enum selabel_cmp_result selabel_cmp(struct selabel_handle *h1,
    148 				    struct selabel_handle *h2);
    149 
    150 /**
    151  * selabel_stats - log labeling operation statistics.
    152  * @handle: specifies backend instance to query
    153  *
    154  * Log a message with information about the number of queries performed,
    155  * number of unused matching entries, or other operational statistics.
    156  * Message is backend-specific, some backends may not output a message.
    157  */
    158 void selabel_stats(struct selabel_handle *handle);
    159 
    160 /*
    161  * Type codes used by specific backends
    162  */
    163 
    164 /* X backend */
    165 #define SELABEL_X_PROP		1
    166 #define SELABEL_X_EXT		2
    167 #define SELABEL_X_CLIENT	3
    168 #define SELABEL_X_EVENT		4
    169 #define SELABEL_X_SELN		5
    170 #define SELABEL_X_POLYPROP	6
    171 #define SELABEL_X_POLYSELN	7
    172 
    173 /* DB backend */
    174 #define SELABEL_DB_DATABASE	1
    175 #define SELABEL_DB_SCHEMA	2
    176 #define SELABEL_DB_TABLE	3
    177 #define SELABEL_DB_COLUMN	4
    178 #define SELABEL_DB_SEQUENCE	5
    179 #define SELABEL_DB_VIEW		6
    180 #define SELABEL_DB_PROCEDURE	7
    181 #define SELABEL_DB_BLOB		8
    182 #define SELABEL_DB_TUPLE	9
    183 #define SELABEL_DB_LANGUAGE	10
    184 #define SELABEL_DB_EXCEPTION 11
    185 #define SELABEL_DB_DATATYPE 12
    186 
    187 #ifdef __cplusplus
    188 }
    189 #endif
    190 #endif	/* _SELABEL_H_ */
    191