Loading...
1/* Authors: Karl MacMillan <kmacmillan@tresys.com>
2 * Frank Mayer <mayerf@tresys.com>
3 *
4 * Copyright (C) 2003 - 2004 Tresys Technology, LLC
5 * This program is free software; you can redistribute it and/or modify
6 * it under the terms of the GNU General Public License as published by
7 * the Free Software Foundation, version 2.
8 */
9
10#include <linux/kernel.h>
11#include <linux/errno.h>
12#include <linux/string.h>
13#include <linux/spinlock.h>
14#include <linux/slab.h>
15
16#include "security.h"
17#include "conditional.h"
18#include "services.h"
19
20/*
21 * cond_evaluate_expr evaluates a conditional expr
22 * in reverse polish notation. It returns true (1), false (0),
23 * or undefined (-1). Undefined occurs when the expression
24 * exceeds the stack depth of COND_EXPR_MAXDEPTH.
25 */
26static int cond_evaluate_expr(struct policydb *p, struct cond_expr *expr)
27{
28
29 struct cond_expr *cur;
30 int s[COND_EXPR_MAXDEPTH];
31 int sp = -1;
32
33 for (cur = expr; cur; cur = cur->next) {
34 switch (cur->expr_type) {
35 case COND_BOOL:
36 if (sp == (COND_EXPR_MAXDEPTH - 1))
37 return -1;
38 sp++;
39 s[sp] = p->bool_val_to_struct[cur->bool - 1]->state;
40 break;
41 case COND_NOT:
42 if (sp < 0)
43 return -1;
44 s[sp] = !s[sp];
45 break;
46 case COND_OR:
47 if (sp < 1)
48 return -1;
49 sp--;
50 s[sp] |= s[sp + 1];
51 break;
52 case COND_AND:
53 if (sp < 1)
54 return -1;
55 sp--;
56 s[sp] &= s[sp + 1];
57 break;
58 case COND_XOR:
59 if (sp < 1)
60 return -1;
61 sp--;
62 s[sp] ^= s[sp + 1];
63 break;
64 case COND_EQ:
65 if (sp < 1)
66 return -1;
67 sp--;
68 s[sp] = (s[sp] == s[sp + 1]);
69 break;
70 case COND_NEQ:
71 if (sp < 1)
72 return -1;
73 sp--;
74 s[sp] = (s[sp] != s[sp + 1]);
75 break;
76 default:
77 return -1;
78 }
79 }
80 return s[0];
81}
82
83/*
84 * evaluate_cond_node evaluates the conditional stored in
85 * a struct cond_node and if the result is different than the
86 * current state of the node it sets the rules in the true/false
87 * list appropriately. If the result of the expression is undefined
88 * all of the rules are disabled for safety.
89 */
90int evaluate_cond_node(struct policydb *p, struct cond_node *node)
91{
92 int new_state;
93 struct cond_av_list *cur;
94
95 new_state = cond_evaluate_expr(p, node->expr);
96 if (new_state != node->cur_state) {
97 node->cur_state = new_state;
98 if (new_state == -1)
99 printk(KERN_ERR "SELinux: expression result was undefined - disabling all rules.\n");
100 /* turn the rules on or off */
101 for (cur = node->true_list; cur; cur = cur->next) {
102 if (new_state <= 0)
103 cur->node->key.specified &= ~AVTAB_ENABLED;
104 else
105 cur->node->key.specified |= AVTAB_ENABLED;
106 }
107
108 for (cur = node->false_list; cur; cur = cur->next) {
109 /* -1 or 1 */
110 if (new_state)
111 cur->node->key.specified &= ~AVTAB_ENABLED;
112 else
113 cur->node->key.specified |= AVTAB_ENABLED;
114 }
115 }
116 return 0;
117}
118
119int cond_policydb_init(struct policydb *p)
120{
121 int rc;
122
123 p->bool_val_to_struct = NULL;
124 p->cond_list = NULL;
125
126 rc = avtab_init(&p->te_cond_avtab);
127 if (rc)
128 return rc;
129
130 return 0;
131}
132
133static void cond_av_list_destroy(struct cond_av_list *list)
134{
135 struct cond_av_list *cur, *next;
136 for (cur = list; cur; cur = next) {
137 next = cur->next;
138 /* the avtab_ptr_t node is destroy by the avtab */
139 kfree(cur);
140 }
141}
142
143static void cond_node_destroy(struct cond_node *node)
144{
145 struct cond_expr *cur_expr, *next_expr;
146
147 for (cur_expr = node->expr; cur_expr; cur_expr = next_expr) {
148 next_expr = cur_expr->next;
149 kfree(cur_expr);
150 }
151 cond_av_list_destroy(node->true_list);
152 cond_av_list_destroy(node->false_list);
153 kfree(node);
154}
155
156static void cond_list_destroy(struct cond_node *list)
157{
158 struct cond_node *next, *cur;
159
160 if (list == NULL)
161 return;
162
163 for (cur = list; cur; cur = next) {
164 next = cur->next;
165 cond_node_destroy(cur);
166 }
167}
168
169void cond_policydb_destroy(struct policydb *p)
170{
171 kfree(p->bool_val_to_struct);
172 avtab_destroy(&p->te_cond_avtab);
173 cond_list_destroy(p->cond_list);
174}
175
176int cond_init_bool_indexes(struct policydb *p)
177{
178 kfree(p->bool_val_to_struct);
179 p->bool_val_to_struct =
180 kmalloc(p->p_bools.nprim * sizeof(struct cond_bool_datum *), GFP_KERNEL);
181 if (!p->bool_val_to_struct)
182 return -ENOMEM;
183 return 0;
184}
185
186int cond_destroy_bool(void *key, void *datum, void *p)
187{
188 kfree(key);
189 kfree(datum);
190 return 0;
191}
192
193int cond_index_bool(void *key, void *datum, void *datap)
194{
195 struct policydb *p;
196 struct cond_bool_datum *booldatum;
197 struct flex_array *fa;
198
199 booldatum = datum;
200 p = datap;
201
202 if (!booldatum->value || booldatum->value > p->p_bools.nprim)
203 return -EINVAL;
204
205 fa = p->sym_val_to_name[SYM_BOOLS];
206 if (flex_array_put_ptr(fa, booldatum->value - 1, key,
207 GFP_KERNEL | __GFP_ZERO))
208 BUG();
209 p->bool_val_to_struct[booldatum->value - 1] = booldatum;
210
211 return 0;
212}
213
214static int bool_isvalid(struct cond_bool_datum *b)
215{
216 if (!(b->state == 0 || b->state == 1))
217 return 0;
218 return 1;
219}
220
221int cond_read_bool(struct policydb *p, struct hashtab *h, void *fp)
222{
223 char *key = NULL;
224 struct cond_bool_datum *booldatum;
225 __le32 buf[3];
226 u32 len;
227 int rc;
228
229 booldatum = kzalloc(sizeof(struct cond_bool_datum), GFP_KERNEL);
230 if (!booldatum)
231 return -ENOMEM;
232
233 rc = next_entry(buf, fp, sizeof buf);
234 if (rc)
235 goto err;
236
237 booldatum->value = le32_to_cpu(buf[0]);
238 booldatum->state = le32_to_cpu(buf[1]);
239
240 rc = -EINVAL;
241 if (!bool_isvalid(booldatum))
242 goto err;
243
244 len = le32_to_cpu(buf[2]);
245
246 rc = -ENOMEM;
247 key = kmalloc(len + 1, GFP_KERNEL);
248 if (!key)
249 goto err;
250 rc = next_entry(key, fp, len);
251 if (rc)
252 goto err;
253 key[len] = '\0';
254 rc = hashtab_insert(h, key, booldatum);
255 if (rc)
256 goto err;
257
258 return 0;
259err:
260 cond_destroy_bool(key, booldatum, NULL);
261 return rc;
262}
263
264struct cond_insertf_data {
265 struct policydb *p;
266 struct cond_av_list *other;
267 struct cond_av_list *head;
268 struct cond_av_list *tail;
269};
270
271static int cond_insertf(struct avtab *a, struct avtab_key *k, struct avtab_datum *d, void *ptr)
272{
273 struct cond_insertf_data *data = ptr;
274 struct policydb *p = data->p;
275 struct cond_av_list *other = data->other, *list, *cur;
276 struct avtab_node *node_ptr;
277 u8 found;
278 int rc = -EINVAL;
279
280 /*
281 * For type rules we have to make certain there aren't any
282 * conflicting rules by searching the te_avtab and the
283 * cond_te_avtab.
284 */
285 if (k->specified & AVTAB_TYPE) {
286 if (avtab_search(&p->te_avtab, k)) {
287 printk(KERN_ERR "SELinux: type rule already exists outside of a conditional.\n");
288 goto err;
289 }
290 /*
291 * If we are reading the false list other will be a pointer to
292 * the true list. We can have duplicate entries if there is only
293 * 1 other entry and it is in our true list.
294 *
295 * If we are reading the true list (other == NULL) there shouldn't
296 * be any other entries.
297 */
298 if (other) {
299 node_ptr = avtab_search_node(&p->te_cond_avtab, k);
300 if (node_ptr) {
301 if (avtab_search_node_next(node_ptr, k->specified)) {
302 printk(KERN_ERR "SELinux: too many conflicting type rules.\n");
303 goto err;
304 }
305 found = 0;
306 for (cur = other; cur; cur = cur->next) {
307 if (cur->node == node_ptr) {
308 found = 1;
309 break;
310 }
311 }
312 if (!found) {
313 printk(KERN_ERR "SELinux: conflicting type rules.\n");
314 goto err;
315 }
316 }
317 } else {
318 if (avtab_search(&p->te_cond_avtab, k)) {
319 printk(KERN_ERR "SELinux: conflicting type rules when adding type rule for true.\n");
320 goto err;
321 }
322 }
323 }
324
325 node_ptr = avtab_insert_nonunique(&p->te_cond_avtab, k, d);
326 if (!node_ptr) {
327 printk(KERN_ERR "SELinux: could not insert rule.\n");
328 rc = -ENOMEM;
329 goto err;
330 }
331
332 list = kzalloc(sizeof(struct cond_av_list), GFP_KERNEL);
333 if (!list) {
334 rc = -ENOMEM;
335 goto err;
336 }
337
338 list->node = node_ptr;
339 if (!data->head)
340 data->head = list;
341 else
342 data->tail->next = list;
343 data->tail = list;
344 return 0;
345
346err:
347 cond_av_list_destroy(data->head);
348 data->head = NULL;
349 return rc;
350}
351
352static int cond_read_av_list(struct policydb *p, void *fp, struct cond_av_list **ret_list, struct cond_av_list *other)
353{
354 int i, rc;
355 __le32 buf[1];
356 u32 len;
357 struct cond_insertf_data data;
358
359 *ret_list = NULL;
360
361 len = 0;
362 rc = next_entry(buf, fp, sizeof(u32));
363 if (rc)
364 return rc;
365
366 len = le32_to_cpu(buf[0]);
367 if (len == 0)
368 return 0;
369
370 data.p = p;
371 data.other = other;
372 data.head = NULL;
373 data.tail = NULL;
374 for (i = 0; i < len; i++) {
375 rc = avtab_read_item(&p->te_cond_avtab, fp, p, cond_insertf,
376 &data);
377 if (rc)
378 return rc;
379 }
380
381 *ret_list = data.head;
382 return 0;
383}
384
385static int expr_isvalid(struct policydb *p, struct cond_expr *expr)
386{
387 if (expr->expr_type <= 0 || expr->expr_type > COND_LAST) {
388 printk(KERN_ERR "SELinux: conditional expressions uses unknown operator.\n");
389 return 0;
390 }
391
392 if (expr->bool > p->p_bools.nprim) {
393 printk(KERN_ERR "SELinux: conditional expressions uses unknown bool.\n");
394 return 0;
395 }
396 return 1;
397}
398
399static int cond_read_node(struct policydb *p, struct cond_node *node, void *fp)
400{
401 __le32 buf[2];
402 u32 len, i;
403 int rc;
404 struct cond_expr *expr = NULL, *last = NULL;
405
406 rc = next_entry(buf, fp, sizeof(u32) * 2);
407 if (rc)
408 goto err;
409
410 node->cur_state = le32_to_cpu(buf[0]);
411
412 /* expr */
413 len = le32_to_cpu(buf[1]);
414
415 for (i = 0; i < len; i++) {
416 rc = next_entry(buf, fp, sizeof(u32) * 2);
417 if (rc)
418 goto err;
419
420 rc = -ENOMEM;
421 expr = kzalloc(sizeof(struct cond_expr), GFP_KERNEL);
422 if (!expr)
423 goto err;
424
425 expr->expr_type = le32_to_cpu(buf[0]);
426 expr->bool = le32_to_cpu(buf[1]);
427
428 if (!expr_isvalid(p, expr)) {
429 rc = -EINVAL;
430 kfree(expr);
431 goto err;
432 }
433
434 if (i == 0)
435 node->expr = expr;
436 else
437 last->next = expr;
438 last = expr;
439 }
440
441 rc = cond_read_av_list(p, fp, &node->true_list, NULL);
442 if (rc)
443 goto err;
444 rc = cond_read_av_list(p, fp, &node->false_list, node->true_list);
445 if (rc)
446 goto err;
447 return 0;
448err:
449 cond_node_destroy(node);
450 return rc;
451}
452
453int cond_read_list(struct policydb *p, void *fp)
454{
455 struct cond_node *node, *last = NULL;
456 __le32 buf[1];
457 u32 i, len;
458 int rc;
459
460 rc = next_entry(buf, fp, sizeof buf);
461 if (rc)
462 return rc;
463
464 len = le32_to_cpu(buf[0]);
465
466 rc = avtab_alloc(&(p->te_cond_avtab), p->te_avtab.nel);
467 if (rc)
468 goto err;
469
470 for (i = 0; i < len; i++) {
471 rc = -ENOMEM;
472 node = kzalloc(sizeof(struct cond_node), GFP_KERNEL);
473 if (!node)
474 goto err;
475
476 rc = cond_read_node(p, node, fp);
477 if (rc)
478 goto err;
479
480 if (i == 0)
481 p->cond_list = node;
482 else
483 last->next = node;
484 last = node;
485 }
486 return 0;
487err:
488 cond_list_destroy(p->cond_list);
489 p->cond_list = NULL;
490 return rc;
491}
492
493int cond_write_bool(void *vkey, void *datum, void *ptr)
494{
495 char *key = vkey;
496 struct cond_bool_datum *booldatum = datum;
497 struct policy_data *pd = ptr;
498 void *fp = pd->fp;
499 __le32 buf[3];
500 u32 len;
501 int rc;
502
503 len = strlen(key);
504 buf[0] = cpu_to_le32(booldatum->value);
505 buf[1] = cpu_to_le32(booldatum->state);
506 buf[2] = cpu_to_le32(len);
507 rc = put_entry(buf, sizeof(u32), 3, fp);
508 if (rc)
509 return rc;
510 rc = put_entry(key, 1, len, fp);
511 if (rc)
512 return rc;
513 return 0;
514}
515
516/*
517 * cond_write_cond_av_list doesn't write out the av_list nodes.
518 * Instead it writes out the key/value pairs from the avtab. This
519 * is necessary because there is no way to uniquely identifying rules
520 * in the avtab so it is not possible to associate individual rules
521 * in the avtab with a conditional without saving them as part of
522 * the conditional. This means that the avtab with the conditional
523 * rules will not be saved but will be rebuilt on policy load.
524 */
525static int cond_write_av_list(struct policydb *p,
526 struct cond_av_list *list, struct policy_file *fp)
527{
528 __le32 buf[1];
529 struct cond_av_list *cur_list;
530 u32 len;
531 int rc;
532
533 len = 0;
534 for (cur_list = list; cur_list != NULL; cur_list = cur_list->next)
535 len++;
536
537 buf[0] = cpu_to_le32(len);
538 rc = put_entry(buf, sizeof(u32), 1, fp);
539 if (rc)
540 return rc;
541
542 if (len == 0)
543 return 0;
544
545 for (cur_list = list; cur_list != NULL; cur_list = cur_list->next) {
546 rc = avtab_write_item(p, cur_list->node, fp);
547 if (rc)
548 return rc;
549 }
550
551 return 0;
552}
553
554static int cond_write_node(struct policydb *p, struct cond_node *node,
555 struct policy_file *fp)
556{
557 struct cond_expr *cur_expr;
558 __le32 buf[2];
559 int rc;
560 u32 len = 0;
561
562 buf[0] = cpu_to_le32(node->cur_state);
563 rc = put_entry(buf, sizeof(u32), 1, fp);
564 if (rc)
565 return rc;
566
567 for (cur_expr = node->expr; cur_expr != NULL; cur_expr = cur_expr->next)
568 len++;
569
570 buf[0] = cpu_to_le32(len);
571 rc = put_entry(buf, sizeof(u32), 1, fp);
572 if (rc)
573 return rc;
574
575 for (cur_expr = node->expr; cur_expr != NULL; cur_expr = cur_expr->next) {
576 buf[0] = cpu_to_le32(cur_expr->expr_type);
577 buf[1] = cpu_to_le32(cur_expr->bool);
578 rc = put_entry(buf, sizeof(u32), 2, fp);
579 if (rc)
580 return rc;
581 }
582
583 rc = cond_write_av_list(p, node->true_list, fp);
584 if (rc)
585 return rc;
586 rc = cond_write_av_list(p, node->false_list, fp);
587 if (rc)
588 return rc;
589
590 return 0;
591}
592
593int cond_write_list(struct policydb *p, struct cond_node *list, void *fp)
594{
595 struct cond_node *cur;
596 u32 len;
597 __le32 buf[1];
598 int rc;
599
600 len = 0;
601 for (cur = list; cur != NULL; cur = cur->next)
602 len++;
603 buf[0] = cpu_to_le32(len);
604 rc = put_entry(buf, sizeof(u32), 1, fp);
605 if (rc)
606 return rc;
607
608 for (cur = list; cur != NULL; cur = cur->next) {
609 rc = cond_write_node(p, cur, fp);
610 if (rc)
611 return rc;
612 }
613
614 return 0;
615}
616
617void cond_compute_xperms(struct avtab *ctab, struct avtab_key *key,
618 struct extended_perms_decision *xpermd)
619{
620 struct avtab_node *node;
621
622 if (!ctab || !key || !xpermd)
623 return;
624
625 for (node = avtab_search_node(ctab, key); node;
626 node = avtab_search_node_next(node, key->specified)) {
627 if (node->key.specified & AVTAB_ENABLED)
628 services_compute_xperms_decision(xpermd, node);
629 }
630 return;
631
632}
633/* Determine whether additional permissions are granted by the conditional
634 * av table, and if so, add them to the result
635 */
636void cond_compute_av(struct avtab *ctab, struct avtab_key *key,
637 struct av_decision *avd, struct extended_perms *xperms)
638{
639 struct avtab_node *node;
640
641 if (!ctab || !key || !avd)
642 return;
643
644 for (node = avtab_search_node(ctab, key); node;
645 node = avtab_search_node_next(node, key->specified)) {
646 if ((u16)(AVTAB_ALLOWED|AVTAB_ENABLED) ==
647 (node->key.specified & (AVTAB_ALLOWED|AVTAB_ENABLED)))
648 avd->allowed |= node->datum.u.data;
649 if ((u16)(AVTAB_AUDITDENY|AVTAB_ENABLED) ==
650 (node->key.specified & (AVTAB_AUDITDENY|AVTAB_ENABLED)))
651 /* Since a '0' in an auditdeny mask represents a
652 * permission we do NOT want to audit (dontaudit), we use
653 * the '&' operand to ensure that all '0's in the mask
654 * are retained (much unlike the allow and auditallow cases).
655 */
656 avd->auditdeny &= node->datum.u.data;
657 if ((u16)(AVTAB_AUDITALLOW|AVTAB_ENABLED) ==
658 (node->key.specified & (AVTAB_AUDITALLOW|AVTAB_ENABLED)))
659 avd->auditallow |= node->datum.u.data;
660 if (xperms && (node->key.specified & AVTAB_ENABLED) &&
661 (node->key.specified & AVTAB_XPERMS))
662 services_compute_xperms_drivers(xperms, node);
663 }
664 return;
665}
1/* Authors: Karl MacMillan <kmacmillan@tresys.com>
2 * Frank Mayer <mayerf@tresys.com>
3 *
4 * Copyright (C) 2003 - 2004 Tresys Technology, LLC
5 * This program is free software; you can redistribute it and/or modify
6 * it under the terms of the GNU General Public License as published by
7 * the Free Software Foundation, version 2.
8 */
9
10#include <linux/kernel.h>
11#include <linux/errno.h>
12#include <linux/string.h>
13#include <linux/spinlock.h>
14#include <linux/slab.h>
15
16#include "security.h"
17#include "conditional.h"
18#include "services.h"
19
20/*
21 * cond_evaluate_expr evaluates a conditional expr
22 * in reverse polish notation. It returns true (1), false (0),
23 * or undefined (-1). Undefined occurs when the expression
24 * exceeds the stack depth of COND_EXPR_MAXDEPTH.
25 */
26static int cond_evaluate_expr(struct policydb *p, struct cond_expr *expr)
27{
28
29 struct cond_expr *cur;
30 int s[COND_EXPR_MAXDEPTH];
31 int sp = -1;
32
33 for (cur = expr; cur; cur = cur->next) {
34 switch (cur->expr_type) {
35 case COND_BOOL:
36 if (sp == (COND_EXPR_MAXDEPTH - 1))
37 return -1;
38 sp++;
39 s[sp] = p->bool_val_to_struct[cur->bool - 1]->state;
40 break;
41 case COND_NOT:
42 if (sp < 0)
43 return -1;
44 s[sp] = !s[sp];
45 break;
46 case COND_OR:
47 if (sp < 1)
48 return -1;
49 sp--;
50 s[sp] |= s[sp + 1];
51 break;
52 case COND_AND:
53 if (sp < 1)
54 return -1;
55 sp--;
56 s[sp] &= s[sp + 1];
57 break;
58 case COND_XOR:
59 if (sp < 1)
60 return -1;
61 sp--;
62 s[sp] ^= s[sp + 1];
63 break;
64 case COND_EQ:
65 if (sp < 1)
66 return -1;
67 sp--;
68 s[sp] = (s[sp] == s[sp + 1]);
69 break;
70 case COND_NEQ:
71 if (sp < 1)
72 return -1;
73 sp--;
74 s[sp] = (s[sp] != s[sp + 1]);
75 break;
76 default:
77 return -1;
78 }
79 }
80 return s[0];
81}
82
83/*
84 * evaluate_cond_node evaluates the conditional stored in
85 * a struct cond_node and if the result is different than the
86 * current state of the node it sets the rules in the true/false
87 * list appropriately. If the result of the expression is undefined
88 * all of the rules are disabled for safety.
89 */
90int evaluate_cond_node(struct policydb *p, struct cond_node *node)
91{
92 int new_state;
93 struct cond_av_list *cur;
94
95 new_state = cond_evaluate_expr(p, node->expr);
96 if (new_state != node->cur_state) {
97 node->cur_state = new_state;
98 if (new_state == -1)
99 printk(KERN_ERR "SELinux: expression result was undefined - disabling all rules.\n");
100 /* turn the rules on or off */
101 for (cur = node->true_list; cur; cur = cur->next) {
102 if (new_state <= 0)
103 cur->node->key.specified &= ~AVTAB_ENABLED;
104 else
105 cur->node->key.specified |= AVTAB_ENABLED;
106 }
107
108 for (cur = node->false_list; cur; cur = cur->next) {
109 /* -1 or 1 */
110 if (new_state)
111 cur->node->key.specified &= ~AVTAB_ENABLED;
112 else
113 cur->node->key.specified |= AVTAB_ENABLED;
114 }
115 }
116 return 0;
117}
118
119int cond_policydb_init(struct policydb *p)
120{
121 int rc;
122
123 p->bool_val_to_struct = NULL;
124 p->cond_list = NULL;
125
126 rc = avtab_init(&p->te_cond_avtab);
127 if (rc)
128 return rc;
129
130 return 0;
131}
132
133static void cond_av_list_destroy(struct cond_av_list *list)
134{
135 struct cond_av_list *cur, *next;
136 for (cur = list; cur; cur = next) {
137 next = cur->next;
138 /* the avtab_ptr_t node is destroy by the avtab */
139 kfree(cur);
140 }
141}
142
143static void cond_node_destroy(struct cond_node *node)
144{
145 struct cond_expr *cur_expr, *next_expr;
146
147 for (cur_expr = node->expr; cur_expr; cur_expr = next_expr) {
148 next_expr = cur_expr->next;
149 kfree(cur_expr);
150 }
151 cond_av_list_destroy(node->true_list);
152 cond_av_list_destroy(node->false_list);
153 kfree(node);
154}
155
156static void cond_list_destroy(struct cond_node *list)
157{
158 struct cond_node *next, *cur;
159
160 if (list == NULL)
161 return;
162
163 for (cur = list; cur; cur = next) {
164 next = cur->next;
165 cond_node_destroy(cur);
166 }
167}
168
169void cond_policydb_destroy(struct policydb *p)
170{
171 kfree(p->bool_val_to_struct);
172 avtab_destroy(&p->te_cond_avtab);
173 cond_list_destroy(p->cond_list);
174}
175
176int cond_init_bool_indexes(struct policydb *p)
177{
178 kfree(p->bool_val_to_struct);
179 p->bool_val_to_struct =
180 kmalloc(p->p_bools.nprim * sizeof(struct cond_bool_datum *), GFP_KERNEL);
181 if (!p->bool_val_to_struct)
182 return -ENOMEM;
183 return 0;
184}
185
186int cond_destroy_bool(void *key, void *datum, void *p)
187{
188 kfree(key);
189 kfree(datum);
190 return 0;
191}
192
193int cond_index_bool(void *key, void *datum, void *datap)
194{
195 struct policydb *p;
196 struct cond_bool_datum *booldatum;
197 struct flex_array *fa;
198
199 booldatum = datum;
200 p = datap;
201
202 if (!booldatum->value || booldatum->value > p->p_bools.nprim)
203 return -EINVAL;
204
205 fa = p->sym_val_to_name[SYM_BOOLS];
206 if (flex_array_put_ptr(fa, booldatum->value - 1, key,
207 GFP_KERNEL | __GFP_ZERO))
208 BUG();
209 p->bool_val_to_struct[booldatum->value - 1] = booldatum;
210
211 return 0;
212}
213
214static int bool_isvalid(struct cond_bool_datum *b)
215{
216 if (!(b->state == 0 || b->state == 1))
217 return 0;
218 return 1;
219}
220
221int cond_read_bool(struct policydb *p, struct hashtab *h, void *fp)
222{
223 char *key = NULL;
224 struct cond_bool_datum *booldatum;
225 __le32 buf[3];
226 u32 len;
227 int rc;
228
229 booldatum = kzalloc(sizeof(struct cond_bool_datum), GFP_KERNEL);
230 if (!booldatum)
231 return -ENOMEM;
232
233 rc = next_entry(buf, fp, sizeof buf);
234 if (rc)
235 goto err;
236
237 booldatum->value = le32_to_cpu(buf[0]);
238 booldatum->state = le32_to_cpu(buf[1]);
239
240 rc = -EINVAL;
241 if (!bool_isvalid(booldatum))
242 goto err;
243
244 len = le32_to_cpu(buf[2]);
245 if (((len == 0) || (len == (u32)-1)))
246 goto err;
247
248 rc = -ENOMEM;
249 key = kmalloc(len + 1, GFP_KERNEL);
250 if (!key)
251 goto err;
252 rc = next_entry(key, fp, len);
253 if (rc)
254 goto err;
255 key[len] = '\0';
256 rc = hashtab_insert(h, key, booldatum);
257 if (rc)
258 goto err;
259
260 return 0;
261err:
262 cond_destroy_bool(key, booldatum, NULL);
263 return rc;
264}
265
266struct cond_insertf_data {
267 struct policydb *p;
268 struct cond_av_list *other;
269 struct cond_av_list *head;
270 struct cond_av_list *tail;
271};
272
273static int cond_insertf(struct avtab *a, struct avtab_key *k, struct avtab_datum *d, void *ptr)
274{
275 struct cond_insertf_data *data = ptr;
276 struct policydb *p = data->p;
277 struct cond_av_list *other = data->other, *list, *cur;
278 struct avtab_node *node_ptr;
279 u8 found;
280 int rc = -EINVAL;
281
282 /*
283 * For type rules we have to make certain there aren't any
284 * conflicting rules by searching the te_avtab and the
285 * cond_te_avtab.
286 */
287 if (k->specified & AVTAB_TYPE) {
288 if (avtab_search(&p->te_avtab, k)) {
289 printk(KERN_ERR "SELinux: type rule already exists outside of a conditional.\n");
290 goto err;
291 }
292 /*
293 * If we are reading the false list other will be a pointer to
294 * the true list. We can have duplicate entries if there is only
295 * 1 other entry and it is in our true list.
296 *
297 * If we are reading the true list (other == NULL) there shouldn't
298 * be any other entries.
299 */
300 if (other) {
301 node_ptr = avtab_search_node(&p->te_cond_avtab, k);
302 if (node_ptr) {
303 if (avtab_search_node_next(node_ptr, k->specified)) {
304 printk(KERN_ERR "SELinux: too many conflicting type rules.\n");
305 goto err;
306 }
307 found = 0;
308 for (cur = other; cur; cur = cur->next) {
309 if (cur->node == node_ptr) {
310 found = 1;
311 break;
312 }
313 }
314 if (!found) {
315 printk(KERN_ERR "SELinux: conflicting type rules.\n");
316 goto err;
317 }
318 }
319 } else {
320 if (avtab_search(&p->te_cond_avtab, k)) {
321 printk(KERN_ERR "SELinux: conflicting type rules when adding type rule for true.\n");
322 goto err;
323 }
324 }
325 }
326
327 node_ptr = avtab_insert_nonunique(&p->te_cond_avtab, k, d);
328 if (!node_ptr) {
329 printk(KERN_ERR "SELinux: could not insert rule.\n");
330 rc = -ENOMEM;
331 goto err;
332 }
333
334 list = kzalloc(sizeof(struct cond_av_list), GFP_KERNEL);
335 if (!list) {
336 rc = -ENOMEM;
337 goto err;
338 }
339
340 list->node = node_ptr;
341 if (!data->head)
342 data->head = list;
343 else
344 data->tail->next = list;
345 data->tail = list;
346 return 0;
347
348err:
349 cond_av_list_destroy(data->head);
350 data->head = NULL;
351 return rc;
352}
353
354static int cond_read_av_list(struct policydb *p, void *fp, struct cond_av_list **ret_list, struct cond_av_list *other)
355{
356 int i, rc;
357 __le32 buf[1];
358 u32 len;
359 struct cond_insertf_data data;
360
361 *ret_list = NULL;
362
363 len = 0;
364 rc = next_entry(buf, fp, sizeof(u32));
365 if (rc)
366 return rc;
367
368 len = le32_to_cpu(buf[0]);
369 if (len == 0)
370 return 0;
371
372 data.p = p;
373 data.other = other;
374 data.head = NULL;
375 data.tail = NULL;
376 for (i = 0; i < len; i++) {
377 rc = avtab_read_item(&p->te_cond_avtab, fp, p, cond_insertf,
378 &data);
379 if (rc)
380 return rc;
381 }
382
383 *ret_list = data.head;
384 return 0;
385}
386
387static int expr_isvalid(struct policydb *p, struct cond_expr *expr)
388{
389 if (expr->expr_type <= 0 || expr->expr_type > COND_LAST) {
390 printk(KERN_ERR "SELinux: conditional expressions uses unknown operator.\n");
391 return 0;
392 }
393
394 if (expr->bool > p->p_bools.nprim) {
395 printk(KERN_ERR "SELinux: conditional expressions uses unknown bool.\n");
396 return 0;
397 }
398 return 1;
399}
400
401static int cond_read_node(struct policydb *p, struct cond_node *node, void *fp)
402{
403 __le32 buf[2];
404 u32 len, i;
405 int rc;
406 struct cond_expr *expr = NULL, *last = NULL;
407
408 rc = next_entry(buf, fp, sizeof(u32) * 2);
409 if (rc)
410 goto err;
411
412 node->cur_state = le32_to_cpu(buf[0]);
413
414 /* expr */
415 len = le32_to_cpu(buf[1]);
416
417 for (i = 0; i < len; i++) {
418 rc = next_entry(buf, fp, sizeof(u32) * 2);
419 if (rc)
420 goto err;
421
422 rc = -ENOMEM;
423 expr = kzalloc(sizeof(struct cond_expr), GFP_KERNEL);
424 if (!expr)
425 goto err;
426
427 expr->expr_type = le32_to_cpu(buf[0]);
428 expr->bool = le32_to_cpu(buf[1]);
429
430 if (!expr_isvalid(p, expr)) {
431 rc = -EINVAL;
432 kfree(expr);
433 goto err;
434 }
435
436 if (i == 0)
437 node->expr = expr;
438 else
439 last->next = expr;
440 last = expr;
441 }
442
443 rc = cond_read_av_list(p, fp, &node->true_list, NULL);
444 if (rc)
445 goto err;
446 rc = cond_read_av_list(p, fp, &node->false_list, node->true_list);
447 if (rc)
448 goto err;
449 return 0;
450err:
451 cond_node_destroy(node);
452 return rc;
453}
454
455int cond_read_list(struct policydb *p, void *fp)
456{
457 struct cond_node *node, *last = NULL;
458 __le32 buf[1];
459 u32 i, len;
460 int rc;
461
462 rc = next_entry(buf, fp, sizeof buf);
463 if (rc)
464 return rc;
465
466 len = le32_to_cpu(buf[0]);
467
468 rc = avtab_alloc(&(p->te_cond_avtab), p->te_avtab.nel);
469 if (rc)
470 goto err;
471
472 for (i = 0; i < len; i++) {
473 rc = -ENOMEM;
474 node = kzalloc(sizeof(struct cond_node), GFP_KERNEL);
475 if (!node)
476 goto err;
477
478 rc = cond_read_node(p, node, fp);
479 if (rc)
480 goto err;
481
482 if (i == 0)
483 p->cond_list = node;
484 else
485 last->next = node;
486 last = node;
487 }
488 return 0;
489err:
490 cond_list_destroy(p->cond_list);
491 p->cond_list = NULL;
492 return rc;
493}
494
495int cond_write_bool(void *vkey, void *datum, void *ptr)
496{
497 char *key = vkey;
498 struct cond_bool_datum *booldatum = datum;
499 struct policy_data *pd = ptr;
500 void *fp = pd->fp;
501 __le32 buf[3];
502 u32 len;
503 int rc;
504
505 len = strlen(key);
506 buf[0] = cpu_to_le32(booldatum->value);
507 buf[1] = cpu_to_le32(booldatum->state);
508 buf[2] = cpu_to_le32(len);
509 rc = put_entry(buf, sizeof(u32), 3, fp);
510 if (rc)
511 return rc;
512 rc = put_entry(key, 1, len, fp);
513 if (rc)
514 return rc;
515 return 0;
516}
517
518/*
519 * cond_write_cond_av_list doesn't write out the av_list nodes.
520 * Instead it writes out the key/value pairs from the avtab. This
521 * is necessary because there is no way to uniquely identifying rules
522 * in the avtab so it is not possible to associate individual rules
523 * in the avtab with a conditional without saving them as part of
524 * the conditional. This means that the avtab with the conditional
525 * rules will not be saved but will be rebuilt on policy load.
526 */
527static int cond_write_av_list(struct policydb *p,
528 struct cond_av_list *list, struct policy_file *fp)
529{
530 __le32 buf[1];
531 struct cond_av_list *cur_list;
532 u32 len;
533 int rc;
534
535 len = 0;
536 for (cur_list = list; cur_list != NULL; cur_list = cur_list->next)
537 len++;
538
539 buf[0] = cpu_to_le32(len);
540 rc = put_entry(buf, sizeof(u32), 1, fp);
541 if (rc)
542 return rc;
543
544 if (len == 0)
545 return 0;
546
547 for (cur_list = list; cur_list != NULL; cur_list = cur_list->next) {
548 rc = avtab_write_item(p, cur_list->node, fp);
549 if (rc)
550 return rc;
551 }
552
553 return 0;
554}
555
556static int cond_write_node(struct policydb *p, struct cond_node *node,
557 struct policy_file *fp)
558{
559 struct cond_expr *cur_expr;
560 __le32 buf[2];
561 int rc;
562 u32 len = 0;
563
564 buf[0] = cpu_to_le32(node->cur_state);
565 rc = put_entry(buf, sizeof(u32), 1, fp);
566 if (rc)
567 return rc;
568
569 for (cur_expr = node->expr; cur_expr != NULL; cur_expr = cur_expr->next)
570 len++;
571
572 buf[0] = cpu_to_le32(len);
573 rc = put_entry(buf, sizeof(u32), 1, fp);
574 if (rc)
575 return rc;
576
577 for (cur_expr = node->expr; cur_expr != NULL; cur_expr = cur_expr->next) {
578 buf[0] = cpu_to_le32(cur_expr->expr_type);
579 buf[1] = cpu_to_le32(cur_expr->bool);
580 rc = put_entry(buf, sizeof(u32), 2, fp);
581 if (rc)
582 return rc;
583 }
584
585 rc = cond_write_av_list(p, node->true_list, fp);
586 if (rc)
587 return rc;
588 rc = cond_write_av_list(p, node->false_list, fp);
589 if (rc)
590 return rc;
591
592 return 0;
593}
594
595int cond_write_list(struct policydb *p, struct cond_node *list, void *fp)
596{
597 struct cond_node *cur;
598 u32 len;
599 __le32 buf[1];
600 int rc;
601
602 len = 0;
603 for (cur = list; cur != NULL; cur = cur->next)
604 len++;
605 buf[0] = cpu_to_le32(len);
606 rc = put_entry(buf, sizeof(u32), 1, fp);
607 if (rc)
608 return rc;
609
610 for (cur = list; cur != NULL; cur = cur->next) {
611 rc = cond_write_node(p, cur, fp);
612 if (rc)
613 return rc;
614 }
615
616 return 0;
617}
618
619void cond_compute_xperms(struct avtab *ctab, struct avtab_key *key,
620 struct extended_perms_decision *xpermd)
621{
622 struct avtab_node *node;
623
624 if (!ctab || !key || !xpermd)
625 return;
626
627 for (node = avtab_search_node(ctab, key); node;
628 node = avtab_search_node_next(node, key->specified)) {
629 if (node->key.specified & AVTAB_ENABLED)
630 services_compute_xperms_decision(xpermd, node);
631 }
632 return;
633
634}
635/* Determine whether additional permissions are granted by the conditional
636 * av table, and if so, add them to the result
637 */
638void cond_compute_av(struct avtab *ctab, struct avtab_key *key,
639 struct av_decision *avd, struct extended_perms *xperms)
640{
641 struct avtab_node *node;
642
643 if (!ctab || !key || !avd)
644 return;
645
646 for (node = avtab_search_node(ctab, key); node;
647 node = avtab_search_node_next(node, key->specified)) {
648 if ((u16)(AVTAB_ALLOWED|AVTAB_ENABLED) ==
649 (node->key.specified & (AVTAB_ALLOWED|AVTAB_ENABLED)))
650 avd->allowed |= node->datum.u.data;
651 if ((u16)(AVTAB_AUDITDENY|AVTAB_ENABLED) ==
652 (node->key.specified & (AVTAB_AUDITDENY|AVTAB_ENABLED)))
653 /* Since a '0' in an auditdeny mask represents a
654 * permission we do NOT want to audit (dontaudit), we use
655 * the '&' operand to ensure that all '0's in the mask
656 * are retained (much unlike the allow and auditallow cases).
657 */
658 avd->auditdeny &= node->datum.u.data;
659 if ((u16)(AVTAB_AUDITALLOW|AVTAB_ENABLED) ==
660 (node->key.specified & (AVTAB_AUDITALLOW|AVTAB_ENABLED)))
661 avd->auditallow |= node->datum.u.data;
662 if (xperms && (node->key.specified & AVTAB_ENABLED) &&
663 (node->key.specified & AVTAB_XPERMS))
664 services_compute_xperms_drivers(xperms, node);
665 }
666 return;
667}