xref: /openbmc/linux/security/selinux/ss/policydb.h (revision 2d68bb26)
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 {
93 	u32 stype;		/* current process */
94 	u32 ttype;		/* parent dir context */
95 	u16 tclass;		/* class of new object */
96 	const char *name;	/* last path component */
97 };
98 
99 struct filename_trans_datum {
100 	u32 otype;		/* expected of new object */
101 };
102 
103 struct role_allow {
104 	u32 role;		/* current role */
105 	u32 new_role;		/* new role */
106 	struct role_allow *next;
107 };
108 
109 /* Type attributes */
110 struct type_datum {
111 	u32 value;		/* internal type value */
112 	u32 bounds;		/* boundary of type */
113 	unsigned char primary;	/* primary name? */
114 	unsigned char attribute;/* attribute ?*/
115 };
116 
117 /* User attributes */
118 struct user_datum {
119 	u32 value;			/* internal user value */
120 	u32 bounds;			/* bounds of user */
121 	struct ebitmap roles;		/* set of authorized roles for user */
122 	struct mls_range range;		/* MLS range (min - max) for user */
123 	struct mls_level dfltlevel;	/* default login MLS level for user */
124 };
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 */
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 role_trans *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 
271 	/* bools indexed by (value - 1) */
272 	struct cond_bool_datum **bool_val_to_struct;
273 	/* type enforcement conditional access vectors and transitions */
274 	struct avtab te_cond_avtab;
275 	/* linked list indexing te_cond_avtab by conditional */
276 	struct cond_node *cond_list;
277 
278 	/* role allows */
279 	struct role_allow *role_allow;
280 
281 	/* security contexts of initial SIDs, unlabeled file systems,
282 	   TCP or UDP port numbers, network interfaces and nodes */
283 	struct ocontext *ocontexts[OCON_NUM];
284 
285 	/* security contexts for files in filesystems that cannot support
286 	   a persistent label mapping or use another
287 	   fixed labeling behavior. */
288 	struct genfs *genfs;
289 
290 	/* range transitions table (range_trans_key -> mls_range) */
291 	struct hashtab *range_tr;
292 
293 	/* type -> attribute reverse mapping */
294 	struct ebitmap *type_attr_map_array;
295 
296 	struct ebitmap policycaps;
297 
298 	struct ebitmap permissive_map;
299 
300 	/* length of this policy when it was loaded */
301 	size_t len;
302 
303 	unsigned int policyvers;
304 
305 	unsigned int reject_unknown : 1;
306 	unsigned int allow_unknown : 1;
307 
308 	u16 process_class;
309 	u32 process_trans_perms;
310 };
311 
312 extern void policydb_destroy(struct policydb *p);
313 extern int policydb_load_isids(struct policydb *p, struct sidtab *s);
314 extern int policydb_context_isvalid(struct policydb *p, struct context *c);
315 extern int policydb_class_isvalid(struct policydb *p, unsigned int class);
316 extern int policydb_type_isvalid(struct policydb *p, unsigned int type);
317 extern int policydb_role_isvalid(struct policydb *p, unsigned int role);
318 extern int policydb_read(struct policydb *p, void *fp);
319 extern int policydb_write(struct policydb *p, void *fp);
320 
321 #define PERM_SYMTAB_SIZE 32
322 
323 #define POLICYDB_CONFIG_MLS    1
324 
325 /* the config flags related to unknown classes/perms are bits 2 and 3 */
326 #define REJECT_UNKNOWN	0x00000002
327 #define ALLOW_UNKNOWN	0x00000004
328 
329 #define OBJECT_R "object_r"
330 #define OBJECT_R_VAL 1
331 
332 #define POLICYDB_MAGIC SELINUX_MAGIC
333 #define POLICYDB_STRING "SE Linux"
334 
335 struct policy_file {
336 	char *data;
337 	size_t len;
338 };
339 
340 struct policy_data {
341 	struct policydb *p;
342 	void *fp;
343 };
344 
345 static inline int next_entry(void *buf, struct policy_file *fp, size_t bytes)
346 {
347 	if (bytes > fp->len)
348 		return -EINVAL;
349 
350 	memcpy(buf, fp->data, bytes);
351 	fp->data += bytes;
352 	fp->len -= bytes;
353 	return 0;
354 }
355 
356 static inline int put_entry(const void *buf, size_t bytes, int num, struct policy_file *fp)
357 {
358 	size_t len = bytes * num;
359 
360 	memcpy(fp->data, buf, len);
361 	fp->data += len;
362 	fp->len -= len;
363 
364 	return 0;
365 }
366 
367 static inline char *sym_name(struct policydb *p, unsigned int sym_num, unsigned int element_nr)
368 {
369 	return p->sym_val_to_name[sym_num][element_nr];
370 }
371 
372 extern u16 string_to_security_class(struct policydb *p, const char *name);
373 extern u32 string_to_av_perm(struct policydb *p, u16 tclass, const char *name);
374 
375 #endif	/* _SS_POLICYDB_H_ */
376 
377