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1 /*
2  * Labeling interface for userspace object managers and others.
3  *
4  * Author : Eamon Walsh <ewalsh@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 extern 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 extern 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 extern int selabel_lookup(struct selabel_handle *handle, char **con,
103 			  const char *key, int type);
104 extern int selabel_lookup_raw(struct selabel_handle *handle, char **con,
105 			      const char *key, int type);
106 
107 extern bool selabel_partial_match(struct selabel_handle *handle, const char *key);
108 
109 extern bool selabel_get_digests_all_partial_matches(struct selabel_handle *rec,
110 						    const char *key,
111 						    uint8_t **calculated_digest,
112 						    uint8_t **xattr_digest,
113 						    size_t *digest_len);
114 extern bool selabel_hash_all_partial_matches(struct selabel_handle *rec,
115 					     const char *key, uint8_t* digest);
116 
117 extern int selabel_lookup_best_match(struct selabel_handle *rec, char **con,
118 				     const char *key, const char **aliases, int type);
119 extern int selabel_lookup_best_match_raw(struct selabel_handle *rec, char **con,
120 					 const char *key, const char **aliases, int type);
121 
122 /**
123  * selabel_digest - Retrieve the SHA1 digest and the list of specfiles used to
124  *		    generate the digest. The SELABEL_OPT_DIGEST option must
125  *		    be set in selabel_open() to initiate the digest generation.
126  * @handle: specifies backend instance to query
127  * @digest: returns a pointer to the SHA1 digest.
128  * @digest_len: returns length of digest in bytes.
129  * @specfiles: a list of specfiles used in the SHA1 digest generation.
130  *	       The list is NULL terminated and will hold @num_specfiles entries.
131  * @num_specfiles: number of specfiles in the list.
132  *
133  * Return %0 on success, -%1 with @errno set on failure.
134  */
135 extern int selabel_digest(struct selabel_handle *rec,
136 			  unsigned char **digest, size_t *digest_len,
137 			  char ***specfiles, size_t *num_specfiles);
138 
139 enum selabel_cmp_result {
140 	SELABEL_SUBSET,
141 	SELABEL_EQUAL,
142 	SELABEL_SUPERSET,
143 	SELABEL_INCOMPARABLE
144 };
145 
146 /**
147  * selabel_cmp - Compare two label configurations.
148  * @h1: handle for the first label configuration
149  * @h2: handle for the first label configuration
150  *
151  * Compare two label configurations.
152  * Return %SELABEL_SUBSET if @h1 is a subset of @h2, %SELABEL_EQUAL
153  * if @h1 is identical to @h2, %SELABEL_SUPERSET if @h1 is a superset
154  * of @h2, and %SELABEL_INCOMPARABLE if @h1 and @h2 are incomparable.
155  */
156 extern enum selabel_cmp_result selabel_cmp(struct selabel_handle *h1,
157 					   struct selabel_handle *h2);
158 
159 /**
160  * selabel_stats - log labeling operation statistics.
161  * @handle: specifies backend instance to query
162  *
163  * Log a message with information about the number of queries performed,
164  * number of unused matching entries, or other operational statistics.
165  * Message is backend-specific, some backends may not output a message.
166  */
167 extern void selabel_stats(struct selabel_handle *handle);
168 
169 /*
170  * Type codes used by specific backends
171  */
172 
173 /* X backend */
174 #define SELABEL_X_PROP		1
175 #define SELABEL_X_EXT		2
176 #define SELABEL_X_CLIENT	3
177 #define SELABEL_X_EVENT		4
178 #define SELABEL_X_SELN		5
179 #define SELABEL_X_POLYPROP	6
180 #define SELABEL_X_POLYSELN	7
181 
182 /* DB backend */
183 #define SELABEL_DB_DATABASE	1
184 #define SELABEL_DB_SCHEMA	2
185 #define SELABEL_DB_TABLE	3
186 #define SELABEL_DB_COLUMN	4
187 #define SELABEL_DB_SEQUENCE	5
188 #define SELABEL_DB_VIEW		6
189 #define SELABEL_DB_PROCEDURE	7
190 #define SELABEL_DB_BLOB		8
191 #define SELABEL_DB_TUPLE	9
192 #define SELABEL_DB_LANGUAGE	10
193 #define SELABEL_DB_EXCEPTION 11
194 #define SELABEL_DB_DATATYPE 12
195 
196 #ifdef __cplusplus
197 }
198 #endif
199 #endif	/* _SELABEL_H_ */
200