xref: /openbmc/linux/security/selinux/ss/policydb.h (revision 15e3ae36)
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, <sds@tycho.nsa.gov>
7  */
8 
9 /*
10  * Updated: Trusted Computer Solutions, Inc. <dgoeddel@trustedcs.com>
11  *
12  *	Support for enhanced MLS infrastructure.
13  *
14  * Updated: Frank Mayer <mayerf@tresys.com> and Karl MacMillan <kmacmillan@tresys.com>
15  *
16  *	Added conditional policy language extensions
17  *
18  * Copyright (C) 2004-2005 Trusted Computer Solutions, Inc.
19  * Copyright (C) 2003 - 2004 Tresys Technology, LLC
20  */
21 
22 #ifndef _SS_POLICYDB_H_
23 #define _SS_POLICYDB_H_
24 
25 #include "symtab.h"
26 #include "avtab.h"
27 #include "sidtab.h"
28 #include "ebitmap.h"
29 #include "mls_types.h"
30 #include "context.h"
31 #include "constraint.h"
32 
33 /*
34  * A datum type is defined for each kind of symbol
35  * in the configuration data:  individual permissions,
36  * common prefixes for access vectors, classes,
37  * users, roles, types, sensitivities, categories, etc.
38  */
39 
40 /* Permission attributes */
41 struct perm_datum {
42 	u32 value;		/* permission bit + 1 */
43 };
44 
45 /* Attributes of a common prefix for access vectors */
46 struct common_datum {
47 	u32 value;			/* internal common value */
48 	struct symtab permissions;	/* common permissions */
49 };
50 
51 /* Class attributes */
52 struct class_datum {
53 	u32 value;			/* class value */
54 	char *comkey;			/* common name */
55 	struct common_datum *comdatum;	/* common datum */
56 	struct symtab permissions;	/* class-specific permission symbol table */
57 	struct constraint_node *constraints;	/* constraints on class permissions */
58 	struct constraint_node *validatetrans;	/* special transition rules */
59 /* Options how a new object user, role, and type should be decided */
60 #define DEFAULT_SOURCE         1
61 #define DEFAULT_TARGET         2
62 	char default_user;
63 	char default_role;
64 	char default_type;
65 /* Options how a new object range should be decided */
66 #define DEFAULT_SOURCE_LOW     1
67 #define DEFAULT_SOURCE_HIGH    2
68 #define DEFAULT_SOURCE_LOW_HIGH        3
69 #define DEFAULT_TARGET_LOW     4
70 #define DEFAULT_TARGET_HIGH    5
71 #define DEFAULT_TARGET_LOW_HIGH        6
72 #define DEFAULT_GLBLUB		7
73 	char default_range;
74 };
75 
76 /* Role attributes */
77 struct role_datum {
78 	u32 value;			/* internal role value */
79 	u32 bounds;			/* boundary of role */
80 	struct ebitmap dominates;	/* set of roles dominated by this role */
81 	struct ebitmap types;		/* set of authorized types for role */
82 };
83 
84 struct role_trans {
85 	u32 role;		/* current role */
86 	u32 type;		/* program executable type, or new object type */
87 	u32 tclass;		/* process class, or new object class */
88 	u32 new_role;		/* new role */
89 	struct role_trans *next;
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 
128 /* Sensitivity attributes */
129 struct level_datum {
130 	struct mls_level *level;	/* sensitivity and associated categories */
131 	unsigned char isalias;	/* is this sensitivity an alias for another? */
132 };
133 
134 /* Category attributes */
135 struct cat_datum {
136 	u32 value;		/* internal category bit + 1 */
137 	unsigned char isalias;  /* is this category an alias for another? */
138 };
139 
140 struct range_trans {
141 	u32 source_type;
142 	u32 target_type;
143 	u32 target_class;
144 };
145 
146 /* Boolean data type */
147 struct cond_bool_datum {
148 	__u32 value;		/* internal type value */
149 	int state;
150 };
151 
152 struct cond_node;
153 
154 /*
155  * type set preserves data needed to determine constraint info from
156  * policy source. This is not used by the kernel policy but allows
157  * utilities such as audit2allow to determine constraint denials.
158  */
159 struct type_set {
160 	struct ebitmap types;
161 	struct ebitmap negset;
162 	u32 flags;
163 };
164 
165 /*
166  * The configuration data includes security contexts for
167  * initial SIDs, unlabeled file systems, TCP and UDP port numbers,
168  * network interfaces, and nodes.  This structure stores the
169  * relevant data for one such entry.  Entries of the same kind
170  * (e.g. all initial SIDs) are linked together into a list.
171  */
172 struct ocontext {
173 	union {
174 		char *name;	/* name of initial SID, fs, netif, fstype, path */
175 		struct {
176 			u8 protocol;
177 			u16 low_port;
178 			u16 high_port;
179 		} port;		/* TCP or UDP port information */
180 		struct {
181 			u32 addr;
182 			u32 mask;
183 		} node;		/* node information */
184 		struct {
185 			u32 addr[4];
186 			u32 mask[4];
187 		} node6;        /* IPv6 node information */
188 		struct {
189 			u64 subnet_prefix;
190 			u16 low_pkey;
191 			u16 high_pkey;
192 		} ibpkey;
193 		struct {
194 			char *dev_name;
195 			u8 port;
196 		} ibendport;
197 	} u;
198 	union {
199 		u32 sclass;  /* security class for genfs */
200 		u32 behavior;  /* labeling behavior for fs_use */
201 	} v;
202 	struct context context[2];	/* security context(s) */
203 	u32 sid[2];	/* SID(s) */
204 	struct ocontext *next;
205 };
206 
207 struct genfs {
208 	char *fstype;
209 	struct ocontext *head;
210 	struct genfs *next;
211 };
212 
213 /* symbol table array indices */
214 #define SYM_COMMONS 0
215 #define SYM_CLASSES 1
216 #define SYM_ROLES   2
217 #define SYM_TYPES   3
218 #define SYM_USERS   4
219 #define SYM_BOOLS   5
220 #define SYM_LEVELS  6
221 #define SYM_CATS    7
222 #define SYM_NUM     8
223 
224 /* object context array indices */
225 #define OCON_ISID	0 /* initial SIDs */
226 #define OCON_FS		1 /* unlabeled file systems */
227 #define OCON_PORT	2 /* TCP and UDP port numbers */
228 #define OCON_NETIF	3 /* network interfaces */
229 #define OCON_NODE	4 /* nodes */
230 #define OCON_FSUSE	5 /* fs_use */
231 #define OCON_NODE6	6 /* IPv6 nodes */
232 #define OCON_IBPKEY	7 /* Infiniband PKeys */
233 #define OCON_IBENDPORT	8 /* Infiniband end ports */
234 #define OCON_NUM	9
235 
236 /* The policy database */
237 struct policydb {
238 	int mls_enabled;
239 
240 	/* symbol tables */
241 	struct symtab symtab[SYM_NUM];
242 #define p_commons symtab[SYM_COMMONS]
243 #define p_classes symtab[SYM_CLASSES]
244 #define p_roles symtab[SYM_ROLES]
245 #define p_types symtab[SYM_TYPES]
246 #define p_users symtab[SYM_USERS]
247 #define p_bools symtab[SYM_BOOLS]
248 #define p_levels symtab[SYM_LEVELS]
249 #define p_cats symtab[SYM_CATS]
250 
251 	/* symbol names indexed by (value - 1) */
252 	char		**sym_val_to_name[SYM_NUM];
253 
254 	/* class, role, and user attributes indexed by (value - 1) */
255 	struct class_datum **class_val_to_struct;
256 	struct role_datum **role_val_to_struct;
257 	struct user_datum **user_val_to_struct;
258 	struct type_datum **type_val_to_struct;
259 
260 	/* type enforcement access vectors and transitions */
261 	struct avtab te_avtab;
262 
263 	/* role transitions */
264 	struct role_trans *role_tr;
265 
266 	/* file transitions with the last path component */
267 	/* quickly exclude lookups when parent ttype has no rules */
268 	struct ebitmap filename_trans_ttypes;
269 	/* actual set of filename_trans rules */
270 	struct hashtab *filename_trans;
271 	u32 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 #define POLICYDB_CONFIG_MLS    1
325 
326 /* the config flags related to unknown classes/perms are bits 2 and 3 */
327 #define REJECT_UNKNOWN	0x00000002
328 #define ALLOW_UNKNOWN	0x00000004
329 
330 #define OBJECT_R "object_r"
331 #define OBJECT_R_VAL 1
332 
333 #define POLICYDB_MAGIC SELINUX_MAGIC
334 #define POLICYDB_STRING "SE Linux"
335 
336 struct policy_file {
337 	char *data;
338 	size_t len;
339 };
340 
341 struct policy_data {
342 	struct policydb *p;
343 	void *fp;
344 };
345 
346 static inline int next_entry(void *buf, struct policy_file *fp, size_t bytes)
347 {
348 	if (bytes > fp->len)
349 		return -EINVAL;
350 
351 	memcpy(buf, fp->data, bytes);
352 	fp->data += bytes;
353 	fp->len -= bytes;
354 	return 0;
355 }
356 
357 static inline int put_entry(const void *buf, size_t bytes, int num, struct policy_file *fp)
358 {
359 	size_t len = bytes * num;
360 
361 	memcpy(fp->data, buf, len);
362 	fp->data += len;
363 	fp->len -= len;
364 
365 	return 0;
366 }
367 
368 static inline char *sym_name(struct policydb *p, unsigned int sym_num, unsigned int element_nr)
369 {
370 	return p->sym_val_to_name[sym_num][element_nr];
371 }
372 
373 extern u16 string_to_security_class(struct policydb *p, const char *name);
374 extern u32 string_to_av_perm(struct policydb *p, u16 tclass, const char *name);
375 
376 #endif	/* _SS_POLICYDB_H_ */
377 
378