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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 <stdint.h>
     11 #include <sys/types.h>
     12 #include <selinux/selinux.h>
     13 
     14 #ifdef __cplusplus
     15 extern "C" {
     16 #endif
     17 
     18 /*
     19  * Opaque type used for all label handles.
     20  */
     21 
     22 struct selabel_handle;
     23 
     24 /*
     25  * Available backends.
     26  */
     27 
     28 /* file contexts */
     29 #define SELABEL_CTX_FILE	0
     30 /* media contexts */
     31 #define SELABEL_CTX_MEDIA	1
     32 /* x contexts */
     33 #define SELABEL_CTX_X		2
     34 /* db objects */
     35 #define SELABEL_CTX_DB		3
     36 /* Android property service contexts */
     37 #define SELABEL_CTX_ANDROID_PROP 4
     38 /* Android service contexts */
     39 #define SELABEL_CTX_ANDROID_SERVICE 5
     40 
     41 /*
     42  * Available options
     43  */
     44 
     45 /* no-op option, useful for unused slots in an array of options */
     46 #define SELABEL_OPT_UNUSED	0
     47 /* validate contexts before returning them (boolean value) */
     48 #define SELABEL_OPT_VALIDATE	1
     49 /* don't use local customizations to backend data (boolean value) */
     50 #define SELABEL_OPT_BASEONLY	2
     51 /* specify an alternate path to use when loading backend data */
     52 #define SELABEL_OPT_PATH	3
     53 /* select a subset of the search space as an optimization (file backend) */
     54 #define SELABEL_OPT_SUBSET	4
     55 /* require a hash calculation on spec files */
     56 #define SELABEL_OPT_DIGEST	5
     57 /* total number of options */
     58 #define SELABEL_NOPT		6
     59 
     60 /*
     61  * Label operations
     62  */
     63 
     64 /**
     65  * selabel_open - Create a labeling handle.
     66  * @backend: one of the constants specifying a supported labeling backend.
     67  * @opts: array of selabel_opt structures specifying label options or NULL.
     68  * @nopts: number of elements in opts array or zero for no options.
     69  *
     70  * Open a labeling backend for use.  The available backend identifiers are
     71  * listed above.  Options may be provided via the opts parameter; available
     72  * options are listed above.  Not all options may be supported by every
     73  * backend.  Return value is the created handle on success or NULL with
     74  * @errno set on failure.
     75  */
     76 struct selabel_handle *selabel_open(unsigned int backend,
     77 				    const struct selinux_opt *opts,
     78 				    unsigned nopts);
     79 
     80 /**
     81  * selabel_close - Close a labeling handle.
     82  * @handle: specifies handle to close
     83  *
     84  * Destroy the specified handle, closing files, freeing allocated memory,
     85  * etc.  The handle may not be further used after it has been closed.
     86  */
     87 void selabel_close(struct selabel_handle *handle);
     88 
     89 /**
     90  * selabel_lookup - Perform labeling lookup operation.
     91  * @handle: specifies backend instance to query
     92  * @con: returns the appropriate context with which to label the object
     93  * @key: string input to lookup operation
     94  * @type: numeric input to the lookup operation
     95  *
     96  * Perform a labeling lookup operation.  Return %0 on success, -%1 with
     97  * @errno set on failure.  The key and type arguments are the inputs to the
     98  * lookup operation; appropriate values are dictated by the backend in use.
     99  * The result is returned in the memory pointed to by @con and must be freed
    100  * by the user with freecon().
    101  */
    102 int selabel_lookup(struct selabel_handle *handle, char **con,
    103 		   const char *key, int type);
    104 int selabel_lookup_raw(struct selabel_handle *handle, char **con,
    105 		       const char *key, int type);
    106 
    107 bool selabel_partial_match(struct selabel_handle *handle, const char *key);
    108 
    109 bool selabel_hash_all_partial_matches(struct selabel_handle *rec,
    110                                       const char *key, uint8_t* digest);
    111 
    112 int selabel_lookup_best_match(struct selabel_handle *rec, char **con,
    113 			      const char *key, const char **aliases, int type);
    114 int selabel_lookup_best_match_raw(struct selabel_handle *rec, char **con,
    115 			      const char *key, const char **aliases, int type);
    116 
    117 /**
    118  * selabel_digest - Retrieve the SHA1 digest and the list of specfiles used to
    119  *		    generate the digest. The SELABEL_OPT_DIGEST option must
    120  *		    be set in selabel_open() to initiate the digest generation.
    121  * @handle: specifies backend instance to query
    122  * @digest: returns a pointer to the SHA1 digest.
    123  * @digest_len: returns length of digest in bytes.
    124  * @specfiles: a list of specfiles used in the SHA1 digest generation.
    125  *	       The list is NULL terminated and will hold @num_specfiles entries.
    126  * @num_specfiles: number of specfiles in the list.
    127  *
    128  * Return %0 on success, -%1 with @errno set on failure.
    129  */
    130 int selabel_digest(struct selabel_handle *rec,
    131 			    unsigned char **digest, size_t *digest_len,
    132 			    char ***specfiles, size_t *num_specfiles);
    133 
    134 enum selabel_cmp_result {
    135 	SELABEL_SUBSET,
    136 	SELABEL_EQUAL,
    137 	SELABEL_SUPERSET,
    138 	SELABEL_INCOMPARABLE
    139 };
    140 
    141 /**
    142  * selabel_cmp - Compare two label configurations.
    143  * @h1: handle for the first label configuration
    144  * @h2: handle for the first label configuration
    145  *
    146  * Compare two label configurations.
    147  * Return %SELABEL_SUBSET if @h1 is a subset of @h2, %SELABEL_EQUAL
    148  * if @h1 is identical to @h2, %SELABEL_SUPERSET if @h1 is a superset
    149  * of @h2, and %SELABEL_INCOMPARABLE if @h1 and @h2 are incomparable.
    150  */
    151 enum selabel_cmp_result selabel_cmp(struct selabel_handle *h1,
    152 				    struct selabel_handle *h2);
    153 
    154 /**
    155  * selabel_stats - log labeling operation statistics.
    156  * @handle: specifies backend instance to query
    157  *
    158  * Log a message with information about the number of queries performed,
    159  * number of unused matching entries, or other operational statistics.
    160  * Message is backend-specific, some backends may not output a message.
    161  */
    162 void selabel_stats(struct selabel_handle *handle);
    163 
    164 /*
    165  * Type codes used by specific backends
    166  */
    167 
    168 /* X backend */
    169 #define SELABEL_X_PROP		1
    170 #define SELABEL_X_EXT		2
    171 #define SELABEL_X_CLIENT	3
    172 #define SELABEL_X_EVENT		4
    173 #define SELABEL_X_SELN		5
    174 #define SELABEL_X_POLYPROP	6
    175 #define SELABEL_X_POLYSELN	7
    176 
    177 /* DB backend */
    178 #define SELABEL_DB_DATABASE	1
    179 #define SELABEL_DB_SCHEMA	2
    180 #define SELABEL_DB_TABLE	3
    181 #define SELABEL_DB_COLUMN	4
    182 #define SELABEL_DB_SEQUENCE	5
    183 #define SELABEL_DB_VIEW		6
    184 #define SELABEL_DB_PROCEDURE	7
    185 #define SELABEL_DB_BLOB		8
    186 #define SELABEL_DB_TUPLE	9
    187 #define SELABEL_DB_LANGUAGE	10
    188 #define SELABEL_DB_EXCEPTION 11
    189 #define SELABEL_DB_DATATYPE 12
    190 
    191 #ifdef __cplusplus
    192 }
    193 #endif
    194 #endif	/* _SELABEL_H_ */
    195