xref: /openbmc/linux/security/selinux/ss/policydb.h (revision 1a59d1b8)
1 /*
2  * A policy database (policydb) specifies the
3  * configuration data for the security policy.
4  *
5  * Author : Stephen Smalley, <sds@tycho.nsa.gov>
6  */
7 
8 /*
9  * Updated: Trusted Computer Solutions, Inc. <dgoeddel@trustedcs.com>
10  *
11  *	Support for enhanced MLS infrastructure.
12  *
13  * Updated: Frank Mayer <mayerf@tresys.com> and Karl MacMillan <kmacmillan@tresys.com>
14  *
15  *	Added conditional policy language extensions
16  *
17  * Copyright (C) 2004-2005 Trusted Computer Solutions, Inc.
18  * Copyright (C) 2003 - 2004 Tresys Technology, LLC
19  *	This program is free software; you can redistribute it and/or modify
20  *	it under the terms of the GNU General Public License as published by
21  *	the Free Software Foundation, version 2.
22  */
23 
24 #ifndef _SS_POLICYDB_H_
25 #define _SS_POLICYDB_H_
26 
27 #include "symtab.h"
28 #include "avtab.h"
29 #include "sidtab.h"
30 #include "ebitmap.h"
31 #include "mls_types.h"
32 #include "context.h"
33 #include "constraint.h"
34 
35 /*
36  * A datum type is defined for each kind of symbol
37  * in the configuration data:  individual permissions,
38  * common prefixes for access vectors, classes,
39  * users, roles, types, sensitivities, categories, etc.
40  */
41 
42 /* Permission attributes */
43 struct perm_datum {
44 	u32 value;		/* permission bit + 1 */
45 };
46 
47 /* Attributes of a common prefix for access vectors */
48 struct common_datum {
49 	u32 value;			/* internal common value */
50 	struct symtab permissions;	/* common permissions */
51 };
52 
53 /* Class attributes */
54 struct class_datum {
55 	u32 value;			/* class value */
56 	char *comkey;			/* common name */
57 	struct common_datum *comdatum;	/* common datum */
58 	struct symtab permissions;	/* class-specific permission symbol table */
59 	struct constraint_node *constraints;	/* constraints on class permissions */
60 	struct constraint_node *validatetrans;	/* special transition rules */
61 /* Options how a new object user, role, and type should be decided */
62 #define DEFAULT_SOURCE         1
63 #define DEFAULT_TARGET         2
64 	char default_user;
65 	char default_role;
66 	char default_type;
67 /* Options how a new object range should be decided */
68 #define DEFAULT_SOURCE_LOW     1
69 #define DEFAULT_SOURCE_HIGH    2
70 #define DEFAULT_SOURCE_LOW_HIGH        3
71 #define DEFAULT_TARGET_LOW     4
72 #define DEFAULT_TARGET_HIGH    5
73 #define DEFAULT_TARGET_LOW_HIGH        6
74 	char default_range;
75 };
76 
77 /* Role attributes */
78 struct role_datum {
79 	u32 value;			/* internal role value */
80 	u32 bounds;			/* boundary of role */
81 	struct ebitmap dominates;	/* set of roles dominated by this role */
82 	struct ebitmap types;		/* set of authorized types for role */
83 };
84 
85 struct role_trans {
86 	u32 role;		/* current role */
87 	u32 type;		/* program executable type, or new object type */
88 	u32 tclass;		/* process class, or new object class */
89 	u32 new_role;		/* new role */
90 	struct role_trans *next;
91 };
92 
93 struct filename_trans {
94 	u32 stype;		/* current process */
95 	u32 ttype;		/* parent dir context */
96 	u16 tclass;		/* class of new object */
97 	const char *name;	/* last path component */
98 };
99 
100 struct filename_trans_datum {
101 	u32 otype;		/* expected of new object */
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_array;
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 
272 	/* bools indexed by (value - 1) */
273 	struct cond_bool_datum **bool_val_to_struct;
274 	/* type enforcement conditional access vectors and transitions */
275 	struct avtab te_cond_avtab;
276 	/* linked list indexing te_cond_avtab by conditional */
277 	struct cond_node *cond_list;
278 
279 	/* role allows */
280 	struct role_allow *role_allow;
281 
282 	/* security contexts of initial SIDs, unlabeled file systems,
283 	   TCP or UDP port numbers, network interfaces and nodes */
284 	struct ocontext *ocontexts[OCON_NUM];
285 
286 	/* security contexts for files in filesystems that cannot support
287 	   a persistent label mapping or use another
288 	   fixed labeling behavior. */
289 	struct genfs *genfs;
290 
291 	/* range transitions table (range_trans_key -> mls_range) */
292 	struct hashtab *range_tr;
293 
294 	/* type -> attribute reverse mapping */
295 	struct ebitmap *type_attr_map_array;
296 
297 	struct ebitmap policycaps;
298 
299 	struct ebitmap permissive_map;
300 
301 	/* length of this policy when it was loaded */
302 	size_t len;
303 
304 	unsigned int policyvers;
305 
306 	unsigned int reject_unknown : 1;
307 	unsigned int allow_unknown : 1;
308 
309 	u16 process_class;
310 	u32 process_trans_perms;
311 };
312 
313 extern void policydb_destroy(struct policydb *p);
314 extern int policydb_load_isids(struct policydb *p, struct sidtab *s);
315 extern int policydb_context_isvalid(struct policydb *p, struct context *c);
316 extern int policydb_class_isvalid(struct policydb *p, unsigned int class);
317 extern int policydb_type_isvalid(struct policydb *p, unsigned int type);
318 extern int policydb_role_isvalid(struct policydb *p, unsigned int role);
319 extern int policydb_read(struct policydb *p, void *fp);
320 extern int policydb_write(struct policydb *p, void *fp);
321 
322 #define PERM_SYMTAB_SIZE 32
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