xref: /openbmc/linux/security/selinux/ss/policydb.h (revision e620a1e0)
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 	char default_range;
73 };
74 
75 /* Role attributes */
76 struct role_datum {
77 	u32 value;			/* internal role value */
78 	u32 bounds;			/* boundary of role */
79 	struct ebitmap dominates;	/* set of roles dominated by this role */
80 	struct ebitmap types;		/* set of authorized types for role */
81 };
82 
83 struct role_trans {
84 	u32 role;		/* current role */
85 	u32 type;		/* program executable type, or new object type */
86 	u32 tclass;		/* process class, or new object class */
87 	u32 new_role;		/* new role */
88 	struct role_trans *next;
89 };
90 
91 struct filename_trans {
92 	u32 stype;		/* current process */
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 	u32 otype;		/* expected of new object */
100 };
101 
102 struct role_allow {
103 	u32 role;		/* current role */
104 	u32 new_role;		/* new role */
105 	struct role_allow *next;
106 };
107 
108 /* Type attributes */
109 struct type_datum {
110 	u32 value;		/* internal type value */
111 	u32 bounds;		/* boundary of type */
112 	unsigned char primary;	/* primary name? */
113 	unsigned char attribute;/* attribute ?*/
114 };
115 
116 /* User attributes */
117 struct user_datum {
118 	u32 value;			/* internal user value */
119 	u32 bounds;			/* bounds of user */
120 	struct ebitmap roles;		/* set of authorized roles for user */
121 	struct mls_range range;		/* MLS range (min - max) for user */
122 	struct mls_level dfltlevel;	/* default login MLS level for user */
123 };
124 
125 
126 /* Sensitivity attributes */
127 struct level_datum {
128 	struct mls_level *level;	/* sensitivity and associated categories */
129 	unsigned char isalias;	/* is this sensitivity an alias for another? */
130 };
131 
132 /* Category attributes */
133 struct cat_datum {
134 	u32 value;		/* internal category bit + 1 */
135 	unsigned char isalias;  /* is this category an alias for another? */
136 };
137 
138 struct range_trans {
139 	u32 source_type;
140 	u32 target_type;
141 	u32 target_class;
142 };
143 
144 /* Boolean data type */
145 struct cond_bool_datum {
146 	__u32 value;		/* internal type value */
147 	int state;
148 };
149 
150 struct cond_node;
151 
152 /*
153  * type set preserves data needed to determine constraint info from
154  * policy source. This is not used by the kernel policy but allows
155  * utilities such as audit2allow to determine constraint denials.
156  */
157 struct type_set {
158 	struct ebitmap types;
159 	struct ebitmap negset;
160 	u32 flags;
161 };
162 
163 /*
164  * The configuration data includes security contexts for
165  * initial SIDs, unlabeled file systems, TCP and UDP port numbers,
166  * network interfaces, and nodes.  This structure stores the
167  * relevant data for one such entry.  Entries of the same kind
168  * (e.g. all initial SIDs) are linked together into a list.
169  */
170 struct ocontext {
171 	union {
172 		char *name;	/* name of initial SID, fs, netif, fstype, path */
173 		struct {
174 			u8 protocol;
175 			u16 low_port;
176 			u16 high_port;
177 		} port;		/* TCP or UDP port information */
178 		struct {
179 			u32 addr;
180 			u32 mask;
181 		} node;		/* node information */
182 		struct {
183 			u32 addr[4];
184 			u32 mask[4];
185 		} node6;        /* IPv6 node information */
186 		struct {
187 			u64 subnet_prefix;
188 			u16 low_pkey;
189 			u16 high_pkey;
190 		} ibpkey;
191 		struct {
192 			char *dev_name;
193 			u8 port;
194 		} ibendport;
195 	} u;
196 	union {
197 		u32 sclass;  /* security class for genfs */
198 		u32 behavior;  /* labeling behavior for fs_use */
199 	} v;
200 	struct context context[2];	/* security context(s) */
201 	u32 sid[2];	/* SID(s) */
202 	struct ocontext *next;
203 };
204 
205 struct genfs {
206 	char *fstype;
207 	struct ocontext *head;
208 	struct genfs *next;
209 };
210 
211 /* symbol table array indices */
212 #define SYM_COMMONS 0
213 #define SYM_CLASSES 1
214 #define SYM_ROLES   2
215 #define SYM_TYPES   3
216 #define SYM_USERS   4
217 #define SYM_BOOLS   5
218 #define SYM_LEVELS  6
219 #define SYM_CATS    7
220 #define SYM_NUM     8
221 
222 /* object context array indices */
223 #define OCON_ISID	0 /* initial SIDs */
224 #define OCON_FS		1 /* unlabeled file systems */
225 #define OCON_PORT	2 /* TCP and UDP port numbers */
226 #define OCON_NETIF	3 /* network interfaces */
227 #define OCON_NODE	4 /* nodes */
228 #define OCON_FSUSE	5 /* fs_use */
229 #define OCON_NODE6	6 /* IPv6 nodes */
230 #define OCON_IBPKEY	7 /* Infiniband PKeys */
231 #define OCON_IBENDPORT	8 /* Infiniband end ports */
232 #define OCON_NUM	9
233 
234 /* The policy database */
235 struct policydb {
236 	int mls_enabled;
237 
238 	/* symbol tables */
239 	struct symtab symtab[SYM_NUM];
240 #define p_commons symtab[SYM_COMMONS]
241 #define p_classes symtab[SYM_CLASSES]
242 #define p_roles symtab[SYM_ROLES]
243 #define p_types symtab[SYM_TYPES]
244 #define p_users symtab[SYM_USERS]
245 #define p_bools symtab[SYM_BOOLS]
246 #define p_levels symtab[SYM_LEVELS]
247 #define p_cats symtab[SYM_CATS]
248 
249 	/* symbol names indexed by (value - 1) */
250 	char		**sym_val_to_name[SYM_NUM];
251 
252 	/* class, role, and user attributes indexed by (value - 1) */
253 	struct class_datum **class_val_to_struct;
254 	struct role_datum **role_val_to_struct;
255 	struct user_datum **user_val_to_struct;
256 	struct type_datum **type_val_to_struct;
257 
258 	/* type enforcement access vectors and transitions */
259 	struct avtab te_avtab;
260 
261 	/* role transitions */
262 	struct role_trans *role_tr;
263 
264 	/* file transitions with the last path component */
265 	/* quickly exclude lookups when parent ttype has no rules */
266 	struct ebitmap filename_trans_ttypes;
267 	/* actual set of filename_trans rules */
268 	struct hashtab *filename_trans;
269 
270 	/* bools indexed by (value - 1) */
271 	struct cond_bool_datum **bool_val_to_struct;
272 	/* type enforcement conditional access vectors and transitions */
273 	struct avtab te_cond_avtab;
274 	/* linked list indexing te_cond_avtab by conditional */
275 	struct cond_node *cond_list;
276 
277 	/* role allows */
278 	struct role_allow *role_allow;
279 
280 	/* security contexts of initial SIDs, unlabeled file systems,
281 	   TCP or UDP port numbers, network interfaces and nodes */
282 	struct ocontext *ocontexts[OCON_NUM];
283 
284 	/* security contexts for files in filesystems that cannot support
285 	   a persistent label mapping or use another
286 	   fixed labeling behavior. */
287 	struct genfs *genfs;
288 
289 	/* range transitions table (range_trans_key -> mls_range) */
290 	struct hashtab *range_tr;
291 
292 	/* type -> attribute reverse mapping */
293 	struct ebitmap *type_attr_map_array;
294 
295 	struct ebitmap policycaps;
296 
297 	struct ebitmap permissive_map;
298 
299 	/* length of this policy when it was loaded */
300 	size_t len;
301 
302 	unsigned int policyvers;
303 
304 	unsigned int reject_unknown : 1;
305 	unsigned int allow_unknown : 1;
306 
307 	u16 process_class;
308 	u32 process_trans_perms;
309 };
310 
311 extern void policydb_destroy(struct policydb *p);
312 extern int policydb_load_isids(struct policydb *p, struct sidtab *s);
313 extern int policydb_context_isvalid(struct policydb *p, struct context *c);
314 extern int policydb_class_isvalid(struct policydb *p, unsigned int class);
315 extern int policydb_type_isvalid(struct policydb *p, unsigned int type);
316 extern int policydb_role_isvalid(struct policydb *p, unsigned int role);
317 extern int policydb_read(struct policydb *p, void *fp);
318 extern int policydb_write(struct policydb *p, void *fp);
319 
320 #define PERM_SYMTAB_SIZE 32
321 
322 #define POLICYDB_CONFIG_MLS    1
323 
324 /* the config flags related to unknown classes/perms are bits 2 and 3 */
325 #define REJECT_UNKNOWN	0x00000002
326 #define ALLOW_UNKNOWN	0x00000004
327 
328 #define OBJECT_R "object_r"
329 #define OBJECT_R_VAL 1
330 
331 #define POLICYDB_MAGIC SELINUX_MAGIC
332 #define POLICYDB_STRING "SE Linux"
333 
334 struct policy_file {
335 	char *data;
336 	size_t len;
337 };
338 
339 struct policy_data {
340 	struct policydb *p;
341 	void *fp;
342 };
343 
344 static inline int next_entry(void *buf, struct policy_file *fp, size_t bytes)
345 {
346 	if (bytes > fp->len)
347 		return -EINVAL;
348 
349 	memcpy(buf, fp->data, bytes);
350 	fp->data += bytes;
351 	fp->len -= bytes;
352 	return 0;
353 }
354 
355 static inline int put_entry(const void *buf, size_t bytes, int num, struct policy_file *fp)
356 {
357 	size_t len = bytes * num;
358 
359 	memcpy(fp->data, buf, len);
360 	fp->data += len;
361 	fp->len -= len;
362 
363 	return 0;
364 }
365 
366 static inline char *sym_name(struct policydb *p, unsigned int sym_num, unsigned int element_nr)
367 {
368 	return p->sym_val_to_name[sym_num][element_nr];
369 }
370 
371 extern u16 string_to_security_class(struct policydb *p, const char *name);
372 extern u32 string_to_av_perm(struct policydb *p, u16 tclass, const char *name);
373 
374 #endif	/* _SS_POLICYDB_H_ */
375 
376