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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_key {
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 };
89 
90 struct role_trans_datum {
91 	u32 new_role;		/* new role */
92 };
93 
94 struct filename_trans_key {
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 	struct ebitmap stypes;	/* bitmap of source types for this otype */
102 	u32 otype;		/* resulting type of new object */
103 	struct filename_trans_datum *next;	/* record for next otype*/
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 		struct {
191 			u64 subnet_prefix;
192 			u16 low_pkey;
193 			u16 high_pkey;
194 		} ibpkey;
195 		struct {
196 			char *dev_name;
197 			u8 port;
198 		} ibendport;
199 	} u;
200 	union {
201 		u32 sclass;  /* security class for genfs */
202 		u32 behavior;  /* labeling behavior for fs_use */
203 	} v;
204 	struct context context[2];	/* security context(s) */
205 	u32 sid[2];	/* SID(s) */
206 	struct ocontext *next;
207 };
208 
209 struct genfs {
210 	char *fstype;
211 	struct ocontext *head;
212 	struct genfs *next;
213 };
214 
215 /* symbol table array indices */
216 #define SYM_COMMONS 0
217 #define SYM_CLASSES 1
218 #define SYM_ROLES   2
219 #define SYM_TYPES   3
220 #define SYM_USERS   4
221 #define SYM_BOOLS   5
222 #define SYM_LEVELS  6
223 #define SYM_CATS    7
224 #define SYM_NUM     8
225 
226 /* object context array indices */
227 #define OCON_ISID	0 /* initial SIDs */
228 #define OCON_FS		1 /* unlabeled file systems */
229 #define OCON_PORT	2 /* TCP and UDP port numbers */
230 #define OCON_NETIF	3 /* network interfaces */
231 #define OCON_NODE	4 /* nodes */
232 #define OCON_FSUSE	5 /* fs_use */
233 #define OCON_NODE6	6 /* IPv6 nodes */
234 #define OCON_IBPKEY	7 /* Infiniband PKeys */
235 #define OCON_IBENDPORT	8 /* Infiniband end ports */
236 #define OCON_NUM	9
237 
238 /* The policy database */
239 struct policydb {
240 	int mls_enabled;
241 	int android_netlink_route;
242 	int android_netlink_getneigh;
243 
244 	/* symbol tables */
245 	struct symtab symtab[SYM_NUM];
246 #define p_commons symtab[SYM_COMMONS]
247 #define p_classes symtab[SYM_CLASSES]
248 #define p_roles symtab[SYM_ROLES]
249 #define p_types symtab[SYM_TYPES]
250 #define p_users symtab[SYM_USERS]
251 #define p_bools symtab[SYM_BOOLS]
252 #define p_levels symtab[SYM_LEVELS]
253 #define p_cats symtab[SYM_CATS]
254 
255 	/* symbol names indexed by (value - 1) */
256 	char		**sym_val_to_name[SYM_NUM];
257 
258 	/* class, role, and user attributes indexed by (value - 1) */
259 	struct class_datum **class_val_to_struct;
260 	struct role_datum **role_val_to_struct;
261 	struct user_datum **user_val_to_struct;
262 	struct type_datum **type_val_to_struct;
263 
264 	/* type enforcement access vectors and transitions */
265 	struct avtab te_avtab;
266 
267 	/* role transitions */
268 	struct hashtab role_tr;
269 
270 	/* file transitions with the last path component */
271 	/* quickly exclude lookups when parent ttype has no rules */
272 	struct ebitmap filename_trans_ttypes;
273 	/* actual set of filename_trans rules */
274 	struct hashtab filename_trans;
275 	/* only used if policyvers < POLICYDB_VERSION_COMP_FTRANS */
276 	u32 compat_filename_trans_count;
277 
278 	/* bools indexed by (value - 1) */
279 	struct cond_bool_datum **bool_val_to_struct;
280 	/* type enforcement conditional access vectors and transitions */
281 	struct avtab te_cond_avtab;
282 	/* array indexing te_cond_avtab by conditional */
283 	struct cond_node *cond_list;
284 	u32 cond_list_len;
285 
286 	/* role allows */
287 	struct role_allow *role_allow;
288 
289 	/* security contexts of initial SIDs, unlabeled file systems,
290 	   TCP or UDP port numbers, network interfaces and nodes */
291 	struct ocontext *ocontexts[OCON_NUM];
292 
293 	/* security contexts for files in filesystems that cannot support
294 	   a persistent label mapping or use another
295 	   fixed labeling behavior. */
296 	struct genfs *genfs;
297 
298 	/* range transitions table (range_trans_key -> mls_range) */
299 	struct hashtab range_tr;
300 
301 	/* type -> attribute reverse mapping */
302 	struct ebitmap *type_attr_map_array;
303 
304 	struct ebitmap policycaps;
305 
306 	struct ebitmap permissive_map;
307 
308 	/* length of this policy when it was loaded */
309 	size_t len;
310 
311 	unsigned int policyvers;
312 
313 	unsigned int reject_unknown : 1;
314 	unsigned int allow_unknown : 1;
315 
316 	u16 process_class;
317 	u32 process_trans_perms;
318 } __randomize_layout;
319 
320 extern void policydb_destroy(struct policydb *p);
321 extern int policydb_load_isids(struct policydb *p, struct sidtab *s);
322 extern int policydb_context_isvalid(struct policydb *p, struct context *c);
323 extern int policydb_class_isvalid(struct policydb *p, unsigned int class);
324 extern int policydb_type_isvalid(struct policydb *p, unsigned int type);
325 extern int policydb_role_isvalid(struct policydb *p, unsigned int role);
326 extern int policydb_read(struct policydb *p, void *fp);
327 extern int policydb_write(struct policydb *p, void *fp);
328 
329 extern struct filename_trans_datum *policydb_filenametr_search(
330 	struct policydb *p, struct filename_trans_key *key);
331 
332 extern struct mls_range *policydb_rangetr_search(
333 	struct policydb *p, struct range_trans *key);
334 
335 extern struct role_trans_datum *policydb_roletr_search(
336 	struct policydb *p, struct role_trans_key *key);
337 
338 #define POLICYDB_CONFIG_MLS    1
339 #define POLICYDB_CONFIG_ANDROID_NETLINK_ROUTE    (1 << 31)
340 #define POLICYDB_CONFIG_ANDROID_NETLINK_GETNEIGH (1 << 30)
341 
342 /* the config flags related to unknown classes/perms are bits 2 and 3 */
343 #define REJECT_UNKNOWN	0x00000002
344 #define ALLOW_UNKNOWN	0x00000004
345 
346 #define OBJECT_R "object_r"
347 #define OBJECT_R_VAL 1
348 
349 #define POLICYDB_MAGIC SELINUX_MAGIC
350 #define POLICYDB_STRING "SE Linux"
351 
352 struct policy_file {
353 	char *data;
354 	size_t len;
355 };
356 
357 struct policy_data {
358 	struct policydb *p;
359 	void *fp;
360 };
361 
next_entry(void * buf,struct policy_file * fp,size_t bytes)362 static inline int next_entry(void *buf, struct policy_file *fp, size_t bytes)
363 {
364 	if (bytes > fp->len)
365 		return -EINVAL;
366 
367 	memcpy(buf, fp->data, bytes);
368 	fp->data += bytes;
369 	fp->len -= bytes;
370 	return 0;
371 }
372 
put_entry(const void * buf,size_t bytes,int num,struct policy_file * fp)373 static inline int put_entry(const void *buf, size_t bytes, int num, struct policy_file *fp)
374 {
375 	size_t len = bytes * num;
376 
377 	if (len > fp->len)
378 		return -EINVAL;
379 	memcpy(fp->data, buf, len);
380 	fp->data += len;
381 	fp->len -= len;
382 
383 	return 0;
384 }
385 
sym_name(struct policydb * p,unsigned int sym_num,unsigned int element_nr)386 static inline char *sym_name(struct policydb *p, unsigned int sym_num, unsigned int element_nr)
387 {
388 	return p->sym_val_to_name[sym_num][element_nr];
389 }
390 
391 extern u16 string_to_security_class(struct policydb *p, const char *name);
392 extern u32 string_to_av_perm(struct policydb *p, u16 tclass, const char *name);
393 
394 #endif	/* _SS_POLICYDB_H_ */
395 
396