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