xref: /linux/security/selinux/ss/policydb.h (revision 8b40a46966d294bc64bad0feb13d3304fde738f2)
1 /* SPDX-License-Identifier: GPL-2.0-only */
2 /*
3  * A policy database (policydb) specifies the
4  * configuration data for the security policy.
5  *
6  * Author : Stephen Smalley, <stephen.smalley.work@gmail.com>
7  */
8 
9 /*
10  * Updated: Trusted Computer Solutions, Inc. <dgoeddel@trustedcs.com>
11  *          Support for enhanced MLS infrastructure.
12  *          Copyright (C) 2004-2005 Trusted Computer Solutions, Inc.
13  *
14  * Updated: Frank Mayer <mayerf@tresys.com> and
15  *          Karl MacMillan <kmacmillan@tresys.com>
16  *          Added conditional policy language extensions
17  *          Copyright (C) 2003-2004 Tresys Technology, LLC
18  */
19 
20 #ifndef _SS_POLICYDB_H_
21 #define _SS_POLICYDB_H_
22 
23 #include "symtab.h"
24 #include "avtab.h"
25 #include "sidtab.h"
26 #include "ebitmap.h"
27 #include "mls_types.h"
28 #include "context.h"
29 #include "constraint.h"
30 
31 /*
32  * A datum type is defined for each kind of symbol
33  * in the configuration data:  individual permissions,
34  * common prefixes for access vectors, classes,
35  * users, roles, types, sensitivities, categories, etc.
36  */
37 
38 /* Permission attributes */
39 struct perm_datum {
40 	u32 value; /* permission bit + 1 */
41 };
42 
43 /* Attributes of a common prefix for access vectors */
44 struct common_datum {
45 	u32 value; /* internal common value */
46 	struct symtab permissions; /* common permissions */
47 };
48 
49 /* Class attributes */
50 struct class_datum {
51 	u32 value; /* class value */
52 	char *comkey; /* common name */
53 	struct common_datum *comdatum; /* common datum */
54 	struct symtab permissions; /* class-specific permission symbol table */
55 	struct constraint_node *constraints; /* constraints on class perms */
56 	struct constraint_node *validatetrans; /* special transition rules */
57 /* Options how a new object user, role, and type should be decided */
58 #define DEFAULT_SOURCE 1
59 #define DEFAULT_TARGET 2
60 	char default_user;
61 	char default_role;
62 	char default_type;
63 /* Options how a new object range should be decided */
64 #define DEFAULT_SOURCE_LOW	1
65 #define DEFAULT_SOURCE_HIGH	2
66 #define DEFAULT_SOURCE_LOW_HIGH 3
67 #define DEFAULT_TARGET_LOW	4
68 #define DEFAULT_TARGET_HIGH	5
69 #define DEFAULT_TARGET_LOW_HIGH 6
70 #define DEFAULT_GLBLUB		7
71 	char default_range;
72 };
73 
74 /* Role attributes */
75 struct role_datum {
76 	u32 value; /* internal role value */
77 	u32 bounds; /* boundary of role */
78 	struct ebitmap dominates; /* set of roles dominated by this role */
79 	struct ebitmap types; /* set of authorized types for role */
80 };
81 
82 struct role_trans_key {
83 	u32 role; /* current role */
84 	u32 type; /* program executable type, or new object type */
85 	u32 tclass; /* process class, or new object class */
86 };
87 
88 struct role_trans_datum {
89 	u32 new_role; /* new role */
90 };
91 
92 struct filename_trans_key {
93 	u32 ttype; /* parent dir context */
94 	u16 tclass; /* class of new object */
95 	const char *name; /* last path component */
96 };
97 
98 struct filename_trans_datum {
99 	struct ebitmap stypes; /* bitmap of source types for this otype */
100 	u32 otype; /* resulting type of new object */
101 	struct filename_trans_datum *next; /* record for next otype*/
102 };
103 
104 struct role_allow {
105 	u32 role; /* current role */
106 	u32 new_role; /* new role */
107 	struct role_allow *next;
108 };
109 
110 /* Type attributes */
111 struct type_datum {
112 	u32 value; /* internal type value */
113 	u32 bounds; /* boundary of type */
114 	unsigned char primary; /* primary name? */
115 	unsigned char attribute; /* attribute ?*/
116 };
117 
118 /* User attributes */
119 struct user_datum {
120 	u32 value; /* internal user value */
121 	u32 bounds; /* bounds of user */
122 	struct ebitmap roles; /* set of authorized roles for user */
123 	struct mls_range range; /* MLS range (min - max) for user */
124 	struct mls_level dfltlevel; /* default login MLS level for user */
125 };
126 
127 /* Sensitivity attributes */
128 struct level_datum {
129 	struct mls_level *level; /* sensitivity and associated categories */
130 	unsigned char isalias; /* is this sensitivity an alias for another? */
131 };
132 
133 /* Category attributes */
134 struct cat_datum {
135 	u32 value; /* internal category bit + 1 */
136 	unsigned char isalias; /* is this category an alias for another? */
137 };
138 
139 struct range_trans {
140 	u32 source_type;
141 	u32 target_type;
142 	u32 target_class;
143 };
144 
145 /* Boolean data type */
146 struct cond_bool_datum {
147 	__u32 value; /* internal type value */
148 	int state;
149 };
150 
151 struct cond_node;
152 
153 /*
154  * type set preserves data needed to determine constraint info from
155  * policy source. This is not used by the kernel policy but allows
156  * utilities such as audit2allow to determine constraint denials.
157  */
158 struct type_set {
159 	struct ebitmap types;
160 	struct ebitmap negset;
161 	u32 flags;
162 };
163 
164 /*
165  * The configuration data includes security contexts for
166  * initial SIDs, unlabeled file systems, TCP and UDP port numbers,
167  * network interfaces, and nodes.  This structure stores the
168  * relevant data for one such entry.  Entries of the same kind
169  * (e.g. all initial SIDs) are linked together into a list.
170  */
171 struct ocontext {
172 	union {
173 		char *name; /* name of initial SID, fs, netif, fstype, path */
174 		struct {
175 			u8 protocol;
176 			u16 low_port;
177 			u16 high_port;
178 		} port; /* TCP or UDP port information */
179 		struct {
180 			u32 addr;
181 			u32 mask;
182 		} node; /* node information */
183 		struct {
184 			u32 addr[4];
185 			u32 mask[4];
186 		} node6; /* IPv6 node information */
187 		struct {
188 			u64 subnet_prefix;
189 			u16 low_pkey;
190 			u16 high_pkey;
191 		} ibpkey;
192 		struct {
193 			char *dev_name;
194 			u8 port;
195 		} ibendport;
196 	} u;
197 	union {
198 		u32 sclass; /* security class for genfs */
199 		u32 behavior; /* labeling behavior for fs_use */
200 	} v;
201 	struct context context[2]; /* security context(s) */
202 	u32 sid[2]; /* SID(s) */
203 	struct ocontext *next;
204 };
205 
206 struct genfs {
207 	char *fstype;
208 	struct ocontext *head;
209 	struct genfs *next;
210 };
211 
212 /* symbol table array indices */
213 #define SYM_COMMONS 0
214 #define SYM_CLASSES 1
215 #define SYM_ROLES   2
216 #define SYM_TYPES   3
217 #define SYM_USERS   4
218 #define SYM_BOOLS   5
219 #define SYM_LEVELS  6
220 #define SYM_CATS    7
221 #define SYM_NUM	    8
222 
223 /* object context array indices */
224 #define OCON_ISID      0 /* initial SIDs */
225 #define OCON_FS	       1 /* unlabeled file systems (deprecated) */
226 #define OCON_PORT      2 /* TCP and UDP port numbers */
227 #define OCON_NETIF     3 /* network interfaces */
228 #define OCON_NODE      4 /* nodes */
229 #define OCON_FSUSE     5 /* fs_use */
230 #define OCON_NODE6     6 /* IPv6 nodes */
231 #define OCON_IBPKEY    7 /* Infiniband PKeys */
232 #define OCON_IBENDPORT 8 /* Infiniband end ports */
233 #define OCON_NUM       9
234 
235 /* The policy database */
236 struct policydb {
237 	int mls_enabled;
238 
239 	/* symbol tables */
240 	struct symtab symtab[SYM_NUM];
241 #define p_commons symtab[SYM_COMMONS]
242 #define p_classes symtab[SYM_CLASSES]
243 #define p_roles	  symtab[SYM_ROLES]
244 #define p_types	  symtab[SYM_TYPES]
245 #define p_users	  symtab[SYM_USERS]
246 #define p_bools	  symtab[SYM_BOOLS]
247 #define p_levels  symtab[SYM_LEVELS]
248 #define p_cats	  symtab[SYM_CATS]
249 
250 	/* symbol names indexed by (value - 1) */
251 	char **sym_val_to_name[SYM_NUM];
252 
253 	/* class, role, and user attributes indexed by (value - 1) */
254 	struct class_datum **class_val_to_struct;
255 	struct role_datum **role_val_to_struct;
256 	struct user_datum **user_val_to_struct;
257 	struct type_datum **type_val_to_struct;
258 
259 	/* type enforcement access vectors and transitions */
260 	struct avtab te_avtab;
261 
262 	/* role transitions */
263 	struct hashtab role_tr;
264 
265 	/* file transitions with the last path component */
266 	/* quickly exclude lookups when parent ttype has no rules */
267 	struct ebitmap filename_trans_ttypes;
268 	/* actual set of filename_trans rules */
269 	struct hashtab filename_trans;
270 	/* only used if policyvers < POLICYDB_VERSION_COMP_FTRANS */
271 	u32 compat_filename_trans_count;
272 
273 	/* bools indexed by (value - 1) */
274 	struct cond_bool_datum **bool_val_to_struct;
275 	/* type enforcement conditional access vectors and transitions */
276 	struct avtab te_cond_avtab;
277 	/* array indexing te_cond_avtab by conditional */
278 	struct cond_node *cond_list;
279 	u32 cond_list_len;
280 
281 	/* role allows */
282 	struct role_allow *role_allow;
283 
284 	/* security contexts of initial SIDs, unlabeled file systems,
285 	   TCP or UDP port numbers, network interfaces and nodes */
286 	struct ocontext *ocontexts[OCON_NUM];
287 
288 	/* security contexts for files in filesystems that cannot support
289 	   a persistent label mapping or use another
290 	   fixed labeling behavior. */
291 	struct genfs *genfs;
292 
293 	/* range transitions table (range_trans_key -> mls_range) */
294 	struct hashtab range_tr;
295 
296 	/* type -> attribute reverse mapping */
297 	struct ebitmap *type_attr_map_array;
298 
299 	struct ebitmap policycaps;
300 
301 	struct ebitmap permissive_map;
302 
303 	/* length of this policy when it was loaded */
304 	size_t len;
305 
306 	unsigned int policyvers;
307 
308 	unsigned int reject_unknown : 1;
309 	unsigned int allow_unknown : 1;
310 
311 	u16 process_class;
312 	u32 process_trans_perms;
313 } __randomize_layout;
314 
315 extern void policydb_destroy(struct policydb *p);
316 extern int policydb_load_isids(struct policydb *p, struct sidtab *s);
317 extern int policydb_context_isvalid(struct policydb *p, struct context *c);
318 extern int policydb_class_isvalid(struct policydb *p, unsigned int class);
319 extern int policydb_type_isvalid(struct policydb *p, unsigned int type);
320 extern int policydb_role_isvalid(struct policydb *p, unsigned int role);
321 extern int policydb_read(struct policydb *p, void *fp);
322 extern int policydb_write(struct policydb *p, void *fp);
323 
324 extern struct filename_trans_datum *
325 policydb_filenametr_search(struct policydb *p, struct filename_trans_key *key);
326 
327 extern struct mls_range *policydb_rangetr_search(struct policydb *p,
328 						 struct range_trans *key);
329 
330 extern struct role_trans_datum *
331 policydb_roletr_search(struct policydb *p, struct role_trans_key *key);
332 
333 #define POLICYDB_CONFIG_MLS 1
334 
335 /* the config flags related to unknown classes/perms are bits 2 and 3 */
336 #define REJECT_UNKNOWN 0x00000002
337 #define ALLOW_UNKNOWN  0x00000004
338 
339 #define OBJECT_R     "object_r"
340 #define OBJECT_R_VAL 1
341 
342 #define POLICYDB_MAGIC	SELINUX_MAGIC
343 #define POLICYDB_STRING "SE Linux"
344 
345 struct policy_file {
346 	char *data;
347 	size_t len;
348 };
349 
350 struct policy_data {
351 	struct policydb *p;
352 	void *fp;
353 };
354 
355 static inline int next_entry(void *buf, struct policy_file *fp, size_t bytes)
356 {
357 	if (bytes > fp->len)
358 		return -EINVAL;
359 
360 	memcpy(buf, fp->data, bytes);
361 	fp->data += bytes;
362 	fp->len -= bytes;
363 	return 0;
364 }
365 
366 static inline int put_entry(const void *buf, size_t bytes, size_t num,
367 			    struct policy_file *fp)
368 {
369 	size_t len;
370 
371 	if (unlikely(check_mul_overflow(bytes, num, &len)))
372 		return -EINVAL;
373 
374 	if (len > fp->len)
375 		return -EINVAL;
376 	memcpy(fp->data, buf, len);
377 	fp->data += len;
378 	fp->len -= len;
379 
380 	return 0;
381 }
382 
383 static inline char *sym_name(struct policydb *p, unsigned int sym_num,
384 			     unsigned int element_nr)
385 {
386 	return p->sym_val_to_name[sym_num][element_nr];
387 }
388 
389 extern u16 string_to_security_class(struct policydb *p, const char *name);
390 extern u32 string_to_av_perm(struct policydb *p, u16 tclass, const char *name);
391 
392 #endif /* _SS_POLICYDB_H_ */
393