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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 /* Options how a new object user, role, and type should be decided */
64 #define DEFAULT_SOURCE         1
65 #define DEFAULT_TARGET         2
66 	char default_user;
67 	char default_role;
68 	char default_type;
69 /* Options how a new object range should be decided */
70 #define DEFAULT_SOURCE_LOW     1
71 #define DEFAULT_SOURCE_HIGH    2
72 #define DEFAULT_SOURCE_LOW_HIGH        3
73 #define DEFAULT_TARGET_LOW     4
74 #define DEFAULT_TARGET_HIGH    5
75 #define DEFAULT_TARGET_LOW_HIGH        6
76 	char default_range;
77 };
78 
79 /* Role attributes */
80 struct role_datum {
81 	u32 value;			/* internal role value */
82 	u32 bounds;			/* boundary of role */
83 	struct ebitmap dominates;	/* set of roles dominated by this role */
84 	struct ebitmap types;		/* set of authorized types for role */
85 };
86 
87 struct role_trans {
88 	u32 role;		/* current role */
89 	u32 type;		/* program executable type, or new object type */
90 	u32 tclass;		/* process class, or new object class */
91 	u32 new_role;		/* new role */
92 	struct role_trans *next;
93 };
94 
95 struct filename_trans {
96 	u32 stype;		/* current process */
97 	u32 ttype;		/* parent dir context */
98 	u16 tclass;		/* class of new object */
99 	const char *name;	/* last path component */
100 };
101 
102 struct filename_trans_datum {
103 	u32 otype;		/* expected of new object */
104 };
105 
106 struct role_allow {
107 	u32 role;		/* current role */
108 	u32 new_role;		/* new role */
109 	struct role_allow *next;
110 };
111 
112 /* Type attributes */
113 struct type_datum {
114 	u32 value;		/* internal type value */
115 	u32 bounds;		/* boundary of type */
116 	unsigned char primary;	/* primary name? */
117 	unsigned char attribute;/* attribute ?*/
118 };
119 
120 /* User attributes */
121 struct user_datum {
122 	u32 value;			/* internal user value */
123 	u32 bounds;			/* bounds of user */
124 	struct ebitmap roles;		/* set of authorized roles for user */
125 	struct mls_range range;		/* MLS range (min - max) for user */
126 	struct mls_level dfltlevel;	/* default login MLS level for user */
127 };
128 
129 
130 /* Sensitivity attributes */
131 struct level_datum {
132 	struct mls_level *level;	/* sensitivity and associated categories */
133 	unsigned char isalias;	/* is this sensitivity an alias for another? */
134 };
135 
136 /* Category attributes */
137 struct cat_datum {
138 	u32 value;		/* internal category bit + 1 */
139 	unsigned char isalias;  /* is this category an alias for another? */
140 };
141 
142 struct range_trans {
143 	u32 source_type;
144 	u32 target_type;
145 	u32 target_class;
146 };
147 
148 /* Boolean data type */
149 struct cond_bool_datum {
150 	__u32 value;		/* internal type value */
151 	int state;
152 };
153 
154 struct cond_node;
155 
156 /*
157  * type set preserves data needed to determine constraint info from
158  * policy source. This is not used by the kernel policy but allows
159  * utilities such as audit2allow to determine constraint denials.
160  */
161 struct type_set {
162 	struct ebitmap types;
163 	struct ebitmap negset;
164 	u32 flags;
165 };
166 
167 /*
168  * The configuration data includes security contexts for
169  * initial SIDs, unlabeled file systems, TCP and UDP port numbers,
170  * network interfaces, and nodes.  This structure stores the
171  * relevant data for one such entry.  Entries of the same kind
172  * (e.g. all initial SIDs) are linked together into a list.
173  */
174 struct ocontext {
175 	union {
176 		char *name;	/* name of initial SID, fs, netif, fstype, path */
177 		struct {
178 			u8 protocol;
179 			u16 low_port;
180 			u16 high_port;
181 		} port;		/* TCP or UDP port information */
182 		struct {
183 			u32 addr;
184 			u32 mask;
185 		} node;		/* node information */
186 		struct {
187 			u32 addr[4];
188 			u32 mask[4];
189 		} node6;        /* IPv6 node information */
190 	} u;
191 	union {
192 		u32 sclass;  /* security class for genfs */
193 		u32 behavior;  /* labeling behavior for fs_use */
194 	} v;
195 	struct context context[2];	/* security context(s) */
196 	u32 sid[2];	/* SID(s) */
197 	struct ocontext *next;
198 };
199 
200 struct genfs {
201 	char *fstype;
202 	struct ocontext *head;
203 	struct genfs *next;
204 };
205 
206 /* symbol table array indices */
207 #define SYM_COMMONS 0
208 #define SYM_CLASSES 1
209 #define SYM_ROLES   2
210 #define SYM_TYPES   3
211 #define SYM_USERS   4
212 #define SYM_BOOLS   5
213 #define SYM_LEVELS  6
214 #define SYM_CATS    7
215 #define SYM_NUM     8
216 
217 /* object context array indices */
218 #define OCON_ISID  0	/* initial SIDs */
219 #define OCON_FS    1	/* unlabeled file systems */
220 #define OCON_PORT  2	/* TCP and UDP port numbers */
221 #define OCON_NETIF 3	/* network interfaces */
222 #define OCON_NODE  4	/* nodes */
223 #define OCON_FSUSE 5	/* fs_use */
224 #define OCON_NODE6 6	/* IPv6 nodes */
225 #define OCON_NUM   7
226 
227 /* The policy database */
228 struct policydb {
229 	int mls_enabled;
230 	int android_netlink_route;
231 
232 	/* symbol tables */
233 	struct symtab symtab[SYM_NUM];
234 #define p_commons symtab[SYM_COMMONS]
235 #define p_classes symtab[SYM_CLASSES]
236 #define p_roles symtab[SYM_ROLES]
237 #define p_types symtab[SYM_TYPES]
238 #define p_users symtab[SYM_USERS]
239 #define p_bools symtab[SYM_BOOLS]
240 #define p_levels symtab[SYM_LEVELS]
241 #define p_cats symtab[SYM_CATS]
242 
243 	/* symbol names indexed by (value - 1) */
244 	struct flex_array *sym_val_to_name[SYM_NUM];
245 
246 	/* class, role, and user attributes indexed by (value - 1) */
247 	struct class_datum **class_val_to_struct;
248 	struct role_datum **role_val_to_struct;
249 	struct user_datum **user_val_to_struct;
250 	struct flex_array *type_val_to_struct_array;
251 
252 	/* type enforcement access vectors and transitions */
253 	struct avtab te_avtab;
254 
255 	/* role transitions */
256 	struct role_trans *role_tr;
257 
258 	/* file transitions with the last path component */
259 	/* quickly exclude lookups when parent ttype has no rules */
260 	struct ebitmap filename_trans_ttypes;
261 	/* actual set of filename_trans rules */
262 	struct hashtab *filename_trans;
263 
264 	/* bools indexed by (value - 1) */
265 	struct cond_bool_datum **bool_val_to_struct;
266 	/* type enforcement conditional access vectors and transitions */
267 	struct avtab te_cond_avtab;
268 	/* linked list indexing te_cond_avtab by conditional */
269 	struct cond_node *cond_list;
270 
271 	/* role allows */
272 	struct role_allow *role_allow;
273 
274 	/* security contexts of initial SIDs, unlabeled file systems,
275 	   TCP or UDP port numbers, network interfaces and nodes */
276 	struct ocontext *ocontexts[OCON_NUM];
277 
278 	/* security contexts for files in filesystems that cannot support
279 	   a persistent label mapping or use another
280 	   fixed labeling behavior. */
281 	struct genfs *genfs;
282 
283 	/* range transitions table (range_trans_key -> mls_range) */
284 	struct hashtab *range_tr;
285 
286 	/* type -> attribute reverse mapping */
287 	struct flex_array *type_attr_map_array;
288 
289 	struct ebitmap policycaps;
290 
291 	struct ebitmap permissive_map;
292 
293 	/* length of this policy when it was loaded */
294 	size_t len;
295 
296 	unsigned int policyvers;
297 
298 	unsigned int reject_unknown : 1;
299 	unsigned int allow_unknown : 1;
300 
301 	u16 process_class;
302 	u32 process_trans_perms;
303 };
304 
305 extern void policydb_destroy(struct policydb *p);
306 extern int policydb_load_isids(struct policydb *p, struct sidtab *s);
307 extern int policydb_context_isvalid(struct policydb *p, struct context *c);
308 extern int policydb_class_isvalid(struct policydb *p, unsigned int class);
309 extern int policydb_type_isvalid(struct policydb *p, unsigned int type);
310 extern int policydb_role_isvalid(struct policydb *p, unsigned int role);
311 extern int policydb_read(struct policydb *p, void *fp);
312 extern int policydb_write(struct policydb *p, void *fp);
313 
314 #define PERM_SYMTAB_SIZE 32
315 
316 #define POLICYDB_CONFIG_MLS    1
317 #define POLICYDB_CONFIG_ANDROID_NETLINK_ROUTE    (1 << 31)
318 
319 /* the config flags related to unknown classes/perms are bits 2 and 3 */
320 #define REJECT_UNKNOWN	0x00000002
321 #define ALLOW_UNKNOWN	0x00000004
322 
323 #define OBJECT_R "object_r"
324 #define OBJECT_R_VAL 1
325 
326 #define POLICYDB_MAGIC SELINUX_MAGIC
327 #define POLICYDB_STRING "SE Linux"
328 
329 struct policy_file {
330 	char *data;
331 	size_t len;
332 };
333 
334 struct policy_data {
335 	struct policydb *p;
336 	void *fp;
337 };
338 
next_entry(void * buf,struct policy_file * fp,size_t bytes)339 static inline int next_entry(void *buf, struct policy_file *fp, size_t bytes)
340 {
341 	if (bytes > fp->len)
342 		return -EINVAL;
343 
344 	memcpy(buf, fp->data, bytes);
345 	fp->data += bytes;
346 	fp->len -= bytes;
347 	return 0;
348 }
349 
put_entry(const void * buf,size_t bytes,int num,struct policy_file * fp)350 static inline int put_entry(const void *buf, size_t bytes, int num, struct policy_file *fp)
351 {
352 	size_t len = bytes * num;
353 
354 	memcpy(fp->data, buf, len);
355 	fp->data += len;
356 	fp->len -= len;
357 
358 	return 0;
359 }
360 
sym_name(struct policydb * p,unsigned int sym_num,unsigned int element_nr)361 static inline char *sym_name(struct policydb *p, unsigned int sym_num, unsigned int element_nr)
362 {
363 	struct flex_array *fa = p->sym_val_to_name[sym_num];
364 
365 	return flex_array_get_ptr(fa, element_nr);
366 }
367 
368 extern u16 string_to_security_class(struct policydb *p, const char *name);
369 extern u32 string_to_av_perm(struct policydb *p, u16 tclass, const char *name);
370 
371 #endif	/* _SS_POLICYDB_H_ */
372 
373