xref: /linux/security/selinux/ss/policydb.h (revision 60e13231561b3a4c5269bfa1ef6c0569ad6f28ec)
1 /*
2  * A policy database (policydb) specifies the
3  * configuration data for the security policy.
4  *
5  * Author : Stephen Smalley, <sds@epoch.ncsc.mil>
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 <linux/flex_array.h>
28 
29 #include "symtab.h"
30 #include "avtab.h"
31 #include "sidtab.h"
32 #include "ebitmap.h"
33 #include "mls_types.h"
34 #include "context.h"
35 #include "constraint.h"
36 
37 /*
38  * A datum type is defined for each kind of symbol
39  * in the configuration data:  individual permissions,
40  * common prefixes for access vectors, classes,
41  * users, roles, types, sensitivities, categories, etc.
42  */
43 
44 /* Permission attributes */
45 struct perm_datum {
46 	u32 value;		/* permission bit + 1 */
47 };
48 
49 /* Attributes of a common prefix for access vectors */
50 struct common_datum {
51 	u32 value;			/* internal common value */
52 	struct symtab permissions;	/* common permissions */
53 };
54 
55 /* Class attributes */
56 struct class_datum {
57 	u32 value;			/* class value */
58 	char *comkey;			/* common name */
59 	struct common_datum *comdatum;	/* common datum */
60 	struct symtab permissions;	/* class-specific permission symbol table */
61 	struct constraint_node *constraints;	/* constraints on class permissions */
62 	struct constraint_node *validatetrans;	/* special transition rules */
63 };
64 
65 /* Role attributes */
66 struct role_datum {
67 	u32 value;			/* internal role value */
68 	u32 bounds;			/* boundary of role */
69 	struct ebitmap dominates;	/* set of roles dominated by this role */
70 	struct ebitmap types;		/* set of authorized types for role */
71 };
72 
73 struct role_trans {
74 	u32 role;		/* current role */
75 	u32 type;		/* program executable type, or new object type */
76 	u32 tclass;		/* process class, or new object class */
77 	u32 new_role;		/* new role */
78 	struct role_trans *next;
79 };
80 
81 struct filename_trans {
82 	u32 stype;		/* current process */
83 	u32 ttype;		/* parent dir context */
84 	u16 tclass;		/* class of new object */
85 	const char *name;	/* last path component */
86 };
87 
88 struct filename_trans_datum {
89 	u32 otype;		/* expected of new object */
90 };
91 
92 struct role_allow {
93 	u32 role;		/* current role */
94 	u32 new_role;		/* new role */
95 	struct role_allow *next;
96 };
97 
98 /* Type attributes */
99 struct type_datum {
100 	u32 value;		/* internal type value */
101 	u32 bounds;		/* boundary of type */
102 	unsigned char primary;	/* primary name? */
103 	unsigned char attribute;/* attribute ?*/
104 };
105 
106 /* User attributes */
107 struct user_datum {
108 	u32 value;			/* internal user value */
109 	u32 bounds;			/* bounds of user */
110 	struct ebitmap roles;		/* set of authorized roles for user */
111 	struct mls_range range;		/* MLS range (min - max) for user */
112 	struct mls_level dfltlevel;	/* default login MLS level for user */
113 };
114 
115 
116 /* Sensitivity attributes */
117 struct level_datum {
118 	struct mls_level *level;	/* sensitivity and associated categories */
119 	unsigned char isalias;	/* is this sensitivity an alias for another? */
120 };
121 
122 /* Category attributes */
123 struct cat_datum {
124 	u32 value;		/* internal category bit + 1 */
125 	unsigned char isalias;  /* is this category an alias for another? */
126 };
127 
128 struct range_trans {
129 	u32 source_type;
130 	u32 target_type;
131 	u32 target_class;
132 };
133 
134 /* Boolean data type */
135 struct cond_bool_datum {
136 	__u32 value;		/* internal type value */
137 	int state;
138 };
139 
140 struct cond_node;
141 
142 /*
143  * The configuration data includes security contexts for
144  * initial SIDs, unlabeled file systems, TCP and UDP port numbers,
145  * network interfaces, and nodes.  This structure stores the
146  * relevant data for one such entry.  Entries of the same kind
147  * (e.g. all initial SIDs) are linked together into a list.
148  */
149 struct ocontext {
150 	union {
151 		char *name;	/* name of initial SID, fs, netif, fstype, path */
152 		struct {
153 			u8 protocol;
154 			u16 low_port;
155 			u16 high_port;
156 		} port;		/* TCP or UDP port information */
157 		struct {
158 			u32 addr;
159 			u32 mask;
160 		} node;		/* node information */
161 		struct {
162 			u32 addr[4];
163 			u32 mask[4];
164 		} node6;        /* IPv6 node information */
165 	} u;
166 	union {
167 		u32 sclass;  /* security class for genfs */
168 		u32 behavior;  /* labeling behavior for fs_use */
169 	} v;
170 	struct context context[2];	/* security context(s) */
171 	u32 sid[2];	/* SID(s) */
172 	struct ocontext *next;
173 };
174 
175 struct genfs {
176 	char *fstype;
177 	struct ocontext *head;
178 	struct genfs *next;
179 };
180 
181 /* symbol table array indices */
182 #define SYM_COMMONS 0
183 #define SYM_CLASSES 1
184 #define SYM_ROLES   2
185 #define SYM_TYPES   3
186 #define SYM_USERS   4
187 #define SYM_BOOLS   5
188 #define SYM_LEVELS  6
189 #define SYM_CATS    7
190 #define SYM_NUM     8
191 
192 /* object context array indices */
193 #define OCON_ISID  0	/* initial SIDs */
194 #define OCON_FS    1	/* unlabeled file systems */
195 #define OCON_PORT  2	/* TCP and UDP port numbers */
196 #define OCON_NETIF 3	/* network interfaces */
197 #define OCON_NODE  4	/* nodes */
198 #define OCON_FSUSE 5	/* fs_use */
199 #define OCON_NODE6 6	/* IPv6 nodes */
200 #define OCON_NUM   7
201 
202 /* The policy database */
203 struct policydb {
204 	int mls_enabled;
205 
206 	/* symbol tables */
207 	struct symtab symtab[SYM_NUM];
208 #define p_commons symtab[SYM_COMMONS]
209 #define p_classes symtab[SYM_CLASSES]
210 #define p_roles symtab[SYM_ROLES]
211 #define p_types symtab[SYM_TYPES]
212 #define p_users symtab[SYM_USERS]
213 #define p_bools symtab[SYM_BOOLS]
214 #define p_levels symtab[SYM_LEVELS]
215 #define p_cats symtab[SYM_CATS]
216 
217 	/* symbol names indexed by (value - 1) */
218 	struct flex_array *sym_val_to_name[SYM_NUM];
219 
220 	/* class, role, and user attributes indexed by (value - 1) */
221 	struct class_datum **class_val_to_struct;
222 	struct role_datum **role_val_to_struct;
223 	struct user_datum **user_val_to_struct;
224 	struct flex_array *type_val_to_struct_array;
225 
226 	/* type enforcement access vectors and transitions */
227 	struct avtab te_avtab;
228 
229 	/* role transitions */
230 	struct role_trans *role_tr;
231 
232 	/* file transitions with the last path component */
233 	/* quickly exclude lookups when parent ttype has no rules */
234 	struct ebitmap filename_trans_ttypes;
235 	/* actual set of filename_trans rules */
236 	struct hashtab *filename_trans;
237 
238 	/* bools indexed by (value - 1) */
239 	struct cond_bool_datum **bool_val_to_struct;
240 	/* type enforcement conditional access vectors and transitions */
241 	struct avtab te_cond_avtab;
242 	/* linked list indexing te_cond_avtab by conditional */
243 	struct cond_node *cond_list;
244 
245 	/* role allows */
246 	struct role_allow *role_allow;
247 
248 	/* security contexts of initial SIDs, unlabeled file systems,
249 	   TCP or UDP port numbers, network interfaces and nodes */
250 	struct ocontext *ocontexts[OCON_NUM];
251 
252 	/* security contexts for files in filesystems that cannot support
253 	   a persistent label mapping or use another
254 	   fixed labeling behavior. */
255 	struct genfs *genfs;
256 
257 	/* range transitions table (range_trans_key -> mls_range) */
258 	struct hashtab *range_tr;
259 
260 	/* type -> attribute reverse mapping */
261 	struct flex_array *type_attr_map_array;
262 
263 	struct ebitmap policycaps;
264 
265 	struct ebitmap permissive_map;
266 
267 	/* length of this policy when it was loaded */
268 	size_t len;
269 
270 	unsigned int policyvers;
271 
272 	unsigned int reject_unknown : 1;
273 	unsigned int allow_unknown : 1;
274 
275 	u16 process_class;
276 	u32 process_trans_perms;
277 };
278 
279 extern void policydb_destroy(struct policydb *p);
280 extern int policydb_load_isids(struct policydb *p, struct sidtab *s);
281 extern int policydb_context_isvalid(struct policydb *p, struct context *c);
282 extern int policydb_class_isvalid(struct policydb *p, unsigned int class);
283 extern int policydb_type_isvalid(struct policydb *p, unsigned int type);
284 extern int policydb_role_isvalid(struct policydb *p, unsigned int role);
285 extern int policydb_read(struct policydb *p, void *fp);
286 extern int policydb_write(struct policydb *p, void *fp);
287 
288 #define PERM_SYMTAB_SIZE 32
289 
290 #define POLICYDB_CONFIG_MLS    1
291 
292 /* the config flags related to unknown classes/perms are bits 2 and 3 */
293 #define REJECT_UNKNOWN	0x00000002
294 #define ALLOW_UNKNOWN	0x00000004
295 
296 #define OBJECT_R "object_r"
297 #define OBJECT_R_VAL 1
298 
299 #define POLICYDB_MAGIC SELINUX_MAGIC
300 #define POLICYDB_STRING "SE Linux"
301 
302 struct policy_file {
303 	char *data;
304 	size_t len;
305 };
306 
307 struct policy_data {
308 	struct policydb *p;
309 	void *fp;
310 };
311 
312 static inline int next_entry(void *buf, struct policy_file *fp, size_t bytes)
313 {
314 	if (bytes > fp->len)
315 		return -EINVAL;
316 
317 	memcpy(buf, fp->data, bytes);
318 	fp->data += bytes;
319 	fp->len -= bytes;
320 	return 0;
321 }
322 
323 static inline int put_entry(const void *buf, size_t bytes, int num, struct policy_file *fp)
324 {
325 	size_t len = bytes * num;
326 
327 	memcpy(fp->data, buf, len);
328 	fp->data += len;
329 	fp->len -= len;
330 
331 	return 0;
332 }
333 
334 static inline char *sym_name(struct policydb *p, unsigned int sym_num, unsigned int element_nr)
335 {
336 	struct flex_array *fa = p->sym_val_to_name[sym_num];
337 
338 	return flex_array_get_ptr(fa, element_nr);
339 }
340 
341 extern u16 string_to_security_class(struct policydb *p, const char *name);
342 extern u32 string_to_av_perm(struct policydb *p, u16 tclass, const char *name);
343 
344 #endif	/* _SS_POLICYDB_H_ */
345 
346