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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/* SPDX-License-Identifier: GPL-2.0-only */
2/* Authors: Karl MacMillan <kmacmillan@tresys.com>
3 * Frank Mayer <mayerf@tresys.com>
4 * Copyright (C) 2003 - 2004 Tresys Technology, LLC
5 */
6
7#include <linux/kernel.h>
8#include <linux/errno.h>
9#include <linux/string.h>
10#include <linux/spinlock.h>
11#include <linux/slab.h>
12
13#include "security.h"
14#include "conditional.h"
15#include "services.h"
16
17/*
18 * cond_evaluate_expr evaluates a conditional expr
19 * in reverse polish notation. It returns true (1), false (0),
20 * or undefined (-1). Undefined occurs when the expression
21 * exceeds the stack depth of COND_EXPR_MAXDEPTH.
22 */
23static int cond_evaluate_expr(struct policydb *p, struct cond_expr *expr)
24{
25 u32 i;
26 int s[COND_EXPR_MAXDEPTH];
27 int sp = -1;
28
29 if (expr->len == 0)
30 return -1;
31
32 for (i = 0; i < expr->len; i++) {
33 struct cond_expr_node *node = &expr->nodes[i];
34
35 switch (node->expr_type) {
36 case COND_BOOL:
37 if (sp == (COND_EXPR_MAXDEPTH - 1))
38 return -1;
39 sp++;
40 s[sp] = p->bool_val_to_struct[node->boolean - 1]->state;
41 break;
42 case COND_NOT:
43 if (sp < 0)
44 return -1;
45 s[sp] = !s[sp];
46 break;
47 case COND_OR:
48 if (sp < 1)
49 return -1;
50 sp--;
51 s[sp] |= s[sp + 1];
52 break;
53 case COND_AND:
54 if (sp < 1)
55 return -1;
56 sp--;
57 s[sp] &= s[sp + 1];
58 break;
59 case COND_XOR:
60 if (sp < 1)
61 return -1;
62 sp--;
63 s[sp] ^= s[sp + 1];
64 break;
65 case COND_EQ:
66 if (sp < 1)
67 return -1;
68 sp--;
69 s[sp] = (s[sp] == s[sp + 1]);
70 break;
71 case COND_NEQ:
72 if (sp < 1)
73 return -1;
74 sp--;
75 s[sp] = (s[sp] != s[sp + 1]);
76 break;
77 default:
78 return -1;
79 }
80 }
81 return s[0];
82}
83
84/*
85 * evaluate_cond_node evaluates the conditional stored in
86 * a struct cond_node and if the result is different than the
87 * current state of the node it sets the rules in the true/false
88 * list appropriately. If the result of the expression is undefined
89 * all of the rules are disabled for safety.
90 */
91static void evaluate_cond_node(struct policydb *p, struct cond_node *node)
92{
93 struct avtab_node *avnode;
94 int new_state;
95 u32 i;
96
97 new_state = cond_evaluate_expr(p, &node->expr);
98 if (new_state != node->cur_state) {
99 node->cur_state = new_state;
100 if (new_state == -1)
101 pr_err("SELinux: expression result was undefined - disabling all rules.\n");
102 /* turn the rules on or off */
103 for (i = 0; i < node->true_list.len; i++) {
104 avnode = node->true_list.nodes[i];
105 if (new_state <= 0)
106 avnode->key.specified &= ~AVTAB_ENABLED;
107 else
108 avnode->key.specified |= AVTAB_ENABLED;
109 }
110
111 for (i = 0; i < node->false_list.len; i++) {
112 avnode = node->false_list.nodes[i];
113 /* -1 or 1 */
114 if (new_state)
115 avnode->key.specified &= ~AVTAB_ENABLED;
116 else
117 avnode->key.specified |= AVTAB_ENABLED;
118 }
119 }
120}
121
122void evaluate_cond_nodes(struct policydb *p)
123{
124 u32 i;
125
126 for (i = 0; i < p->cond_list_len; i++)
127 evaluate_cond_node(p, &p->cond_list[i]);
128}
129
130void cond_policydb_init(struct policydb *p)
131{
132 p->bool_val_to_struct = NULL;
133 p->cond_list = NULL;
134 p->cond_list_len = 0;
135
136 avtab_init(&p->te_cond_avtab);
137}
138
139static void cond_node_destroy(struct cond_node *node)
140{
141 kfree(node->expr.nodes);
142 /* the avtab_ptr_t nodes are destroyed by the avtab */
143 kfree(node->true_list.nodes);
144 kfree(node->false_list.nodes);
145}
146
147static void cond_list_destroy(struct policydb *p)
148{
149 u32 i;
150
151 for (i = 0; i < p->cond_list_len; i++)
152 cond_node_destroy(&p->cond_list[i]);
153 kfree(p->cond_list);
154 p->cond_list = NULL;
155 p->cond_list_len = 0;
156}
157
158void cond_policydb_destroy(struct policydb *p)
159{
160 kfree(p->bool_val_to_struct);
161 avtab_destroy(&p->te_cond_avtab);
162 cond_list_destroy(p);
163}
164
165int cond_init_bool_indexes(struct policydb *p)
166{
167 kfree(p->bool_val_to_struct);
168 p->bool_val_to_struct = kmalloc_array(
169 p->p_bools.nprim, sizeof(*p->bool_val_to_struct), GFP_KERNEL);
170 if (!p->bool_val_to_struct)
171 return -ENOMEM;
172
173 avtab_hash_eval(&p->te_cond_avtab, "conditional_rules");
174
175 return 0;
176}
177
178int cond_destroy_bool(void *key, void *datum, void *p)
179{
180 kfree(key);
181 kfree(datum);
182 return 0;
183}
184
185int cond_index_bool(void *key, void *datum, void *datap)
186{
187 struct policydb *p;
188 struct cond_bool_datum *booldatum;
189
190 booldatum = datum;
191 p = datap;
192
193 if (!booldatum->value || booldatum->value > p->p_bools.nprim)
194 return -EINVAL;
195
196 p->sym_val_to_name[SYM_BOOLS][booldatum->value - 1] = key;
197 p->bool_val_to_struct[booldatum->value - 1] = booldatum;
198
199 return 0;
200}
201
202static int bool_isvalid(struct cond_bool_datum *b)
203{
204 if (!(b->state == 0 || b->state == 1))
205 return 0;
206 return 1;
207}
208
209int cond_read_bool(struct policydb *p, struct symtab *s, void *fp)
210{
211 char *key = NULL;
212 struct cond_bool_datum *booldatum;
213 __le32 buf[3];
214 u32 len;
215 int rc;
216
217 booldatum = kzalloc(sizeof(*booldatum), GFP_KERNEL);
218 if (!booldatum)
219 return -ENOMEM;
220
221 rc = next_entry(buf, fp, sizeof(buf));
222 if (rc)
223 goto err;
224
225 booldatum->value = le32_to_cpu(buf[0]);
226 booldatum->state = le32_to_cpu(buf[1]);
227
228 rc = -EINVAL;
229 if (!bool_isvalid(booldatum))
230 goto err;
231
232 len = le32_to_cpu(buf[2]);
233 if (((len == 0) || (len == (u32)-1)))
234 goto err;
235
236 rc = -ENOMEM;
237 key = kmalloc(len + 1, GFP_KERNEL);
238 if (!key)
239 goto err;
240 rc = next_entry(key, fp, len);
241 if (rc)
242 goto err;
243 key[len] = '\0';
244 rc = symtab_insert(s, key, booldatum);
245 if (rc)
246 goto err;
247
248 return 0;
249err:
250 cond_destroy_bool(key, booldatum, NULL);
251 return rc;
252}
253
254struct cond_insertf_data {
255 struct policydb *p;
256 struct avtab_node **dst;
257 struct cond_av_list *other;
258};
259
260static int cond_insertf(struct avtab *a, const struct avtab_key *k,
261 const struct avtab_datum *d, void *ptr)
262{
263 struct cond_insertf_data *data = ptr;
264 struct policydb *p = data->p;
265 struct cond_av_list *other = data->other;
266 struct avtab_node *node_ptr;
267 u32 i;
268 bool found;
269
270 /*
271 * For type rules we have to make certain there aren't any
272 * conflicting rules by searching the te_avtab and the
273 * cond_te_avtab.
274 */
275 if (k->specified & AVTAB_TYPE) {
276 if (avtab_search_node(&p->te_avtab, k)) {
277 pr_err("SELinux: type rule already exists outside of a conditional.\n");
278 return -EINVAL;
279 }
280 /*
281 * If we are reading the false list other will be a pointer to
282 * the true list. We can have duplicate entries if there is only
283 * 1 other entry and it is in our true list.
284 *
285 * If we are reading the true list (other == NULL) there shouldn't
286 * be any other entries.
287 */
288 if (other) {
289 node_ptr = avtab_search_node(&p->te_cond_avtab, k);
290 if (node_ptr) {
291 if (avtab_search_node_next(node_ptr,
292 k->specified)) {
293 pr_err("SELinux: too many conflicting type rules.\n");
294 return -EINVAL;
295 }
296 found = false;
297 for (i = 0; i < other->len; i++) {
298 if (other->nodes[i] == node_ptr) {
299 found = true;
300 break;
301 }
302 }
303 if (!found) {
304 pr_err("SELinux: conflicting type rules.\n");
305 return -EINVAL;
306 }
307 }
308 } else {
309 if (avtab_search_node(&p->te_cond_avtab, k)) {
310 pr_err("SELinux: conflicting type rules when adding type rule for true.\n");
311 return -EINVAL;
312 }
313 }
314 }
315
316 node_ptr = avtab_insert_nonunique(&p->te_cond_avtab, k, d);
317 if (!node_ptr) {
318 pr_err("SELinux: could not insert rule.\n");
319 return -ENOMEM;
320 }
321
322 *data->dst = node_ptr;
323 return 0;
324}
325
326static int cond_read_av_list(struct policydb *p, void *fp,
327 struct cond_av_list *list,
328 struct cond_av_list *other)
329{
330 int rc;
331 __le32 buf[1];
332 u32 i, len;
333 struct cond_insertf_data data;
334
335 rc = next_entry(buf, fp, sizeof(u32));
336 if (rc)
337 return rc;
338
339 len = le32_to_cpu(buf[0]);
340 if (len == 0)
341 return 0;
342
343 list->nodes = kcalloc(len, sizeof(*list->nodes), GFP_KERNEL);
344 if (!list->nodes)
345 return -ENOMEM;
346
347 data.p = p;
348 data.other = other;
349 for (i = 0; i < len; i++) {
350 data.dst = &list->nodes[i];
351 rc = avtab_read_item(&p->te_cond_avtab, fp, p, cond_insertf,
352 &data);
353 if (rc) {
354 kfree(list->nodes);
355 list->nodes = NULL;
356 return rc;
357 }
358 }
359
360 list->len = len;
361 return 0;
362}
363
364static int expr_node_isvalid(struct policydb *p, struct cond_expr_node *expr)
365{
366 if (expr->expr_type <= 0 || expr->expr_type > COND_LAST) {
367 pr_err("SELinux: conditional expressions uses unknown operator.\n");
368 return 0;
369 }
370
371 if (expr->boolean > p->p_bools.nprim) {
372 pr_err("SELinux: conditional expressions uses unknown bool.\n");
373 return 0;
374 }
375 return 1;
376}
377
378static int cond_read_node(struct policydb *p, struct cond_node *node, void *fp)
379{
380 __le32 buf[2];
381 u32 i, len;
382 int rc;
383
384 rc = next_entry(buf, fp, sizeof(u32) * 2);
385 if (rc)
386 return rc;
387
388 node->cur_state = le32_to_cpu(buf[0]);
389
390 /* expr */
391 len = le32_to_cpu(buf[1]);
392 node->expr.nodes = kcalloc(len, sizeof(*node->expr.nodes), GFP_KERNEL);
393 if (!node->expr.nodes)
394 return -ENOMEM;
395
396 node->expr.len = len;
397
398 for (i = 0; i < len; i++) {
399 struct cond_expr_node *expr = &node->expr.nodes[i];
400
401 rc = next_entry(buf, fp, sizeof(u32) * 2);
402 if (rc)
403 return rc;
404
405 expr->expr_type = le32_to_cpu(buf[0]);
406 expr->boolean = le32_to_cpu(buf[1]);
407
408 if (!expr_node_isvalid(p, expr))
409 return -EINVAL;
410 }
411
412 rc = cond_read_av_list(p, fp, &node->true_list, NULL);
413 if (rc)
414 return rc;
415 return cond_read_av_list(p, fp, &node->false_list, &node->true_list);
416}
417
418int cond_read_list(struct policydb *p, void *fp)
419{
420 __le32 buf[1];
421 u32 i, len;
422 int rc;
423
424 rc = next_entry(buf, fp, sizeof(buf));
425 if (rc)
426 return rc;
427
428 len = le32_to_cpu(buf[0]);
429
430 p->cond_list = kcalloc(len, sizeof(*p->cond_list), GFP_KERNEL);
431 if (!p->cond_list)
432 return -ENOMEM;
433
434 rc = avtab_alloc(&(p->te_cond_avtab), p->te_avtab.nel);
435 if (rc)
436 goto err;
437
438 p->cond_list_len = len;
439
440 for (i = 0; i < len; i++) {
441 rc = cond_read_node(p, &p->cond_list[i], fp);
442 if (rc)
443 goto err;
444 }
445 return 0;
446err:
447 cond_list_destroy(p);
448 return rc;
449}
450
451int cond_write_bool(void *vkey, void *datum, void *ptr)
452{
453 char *key = vkey;
454 struct cond_bool_datum *booldatum = datum;
455 struct policy_data *pd = ptr;
456 void *fp = pd->fp;
457 __le32 buf[3];
458 u32 len;
459 int rc;
460
461 len = strlen(key);
462 buf[0] = cpu_to_le32(booldatum->value);
463 buf[1] = cpu_to_le32(booldatum->state);
464 buf[2] = cpu_to_le32(len);
465 rc = put_entry(buf, sizeof(u32), 3, fp);
466 if (rc)
467 return rc;
468 rc = put_entry(key, 1, len, fp);
469 if (rc)
470 return rc;
471 return 0;
472}
473
474/*
475 * cond_write_cond_av_list doesn't write out the av_list nodes.
476 * Instead it writes out the key/value pairs from the avtab. This
477 * is necessary because there is no way to uniquely identifying rules
478 * in the avtab so it is not possible to associate individual rules
479 * in the avtab with a conditional without saving them as part of
480 * the conditional. This means that the avtab with the conditional
481 * rules will not be saved but will be rebuilt on policy load.
482 */
483static int cond_write_av_list(struct policydb *p, struct cond_av_list *list,
484 struct policy_file *fp)
485{
486 __le32 buf[1];
487 u32 i;
488 int rc;
489
490 buf[0] = cpu_to_le32(list->len);
491 rc = put_entry(buf, sizeof(u32), 1, fp);
492 if (rc)
493 return rc;
494
495 for (i = 0; i < list->len; i++) {
496 rc = avtab_write_item(p, list->nodes[i], fp);
497 if (rc)
498 return rc;
499 }
500
501 return 0;
502}
503
504static int cond_write_node(struct policydb *p, struct cond_node *node,
505 struct policy_file *fp)
506{
507 __le32 buf[2];
508 int rc;
509 u32 i;
510
511 buf[0] = cpu_to_le32(node->cur_state);
512 rc = put_entry(buf, sizeof(u32), 1, fp);
513 if (rc)
514 return rc;
515
516 buf[0] = cpu_to_le32(node->expr.len);
517 rc = put_entry(buf, sizeof(u32), 1, fp);
518 if (rc)
519 return rc;
520
521 for (i = 0; i < node->expr.len; i++) {
522 buf[0] = cpu_to_le32(node->expr.nodes[i].expr_type);
523 buf[1] = cpu_to_le32(node->expr.nodes[i].boolean);
524 rc = put_entry(buf, sizeof(u32), 2, fp);
525 if (rc)
526 return rc;
527 }
528
529 rc = cond_write_av_list(p, &node->true_list, fp);
530 if (rc)
531 return rc;
532 rc = cond_write_av_list(p, &node->false_list, fp);
533 if (rc)
534 return rc;
535
536 return 0;
537}
538
539int cond_write_list(struct policydb *p, void *fp)
540{
541 u32 i;
542 __le32 buf[1];
543 int rc;
544
545 buf[0] = cpu_to_le32(p->cond_list_len);
546 rc = put_entry(buf, sizeof(u32), 1, fp);
547 if (rc)
548 return rc;
549
550 for (i = 0; i < p->cond_list_len; i++) {
551 rc = cond_write_node(p, &p->cond_list[i], fp);
552 if (rc)
553 return rc;
554 }
555
556 return 0;
557}
558
559void cond_compute_xperms(struct avtab *ctab, struct avtab_key *key,
560 struct extended_perms_decision *xpermd)
561{
562 struct avtab_node *node;
563
564 if (!ctab || !key || !xpermd)
565 return;
566
567 for (node = avtab_search_node(ctab, key); node;
568 node = avtab_search_node_next(node, key->specified)) {
569 if (node->key.specified & AVTAB_ENABLED)
570 services_compute_xperms_decision(xpermd, node);
571 }
572}
573/* Determine whether additional permissions are granted by the conditional
574 * av table, and if so, add them to the result
575 */
576void cond_compute_av(struct avtab *ctab, struct avtab_key *key,
577 struct av_decision *avd, struct extended_perms *xperms)
578{
579 struct avtab_node *node;
580
581 if (!ctab || !key || !avd)
582 return;
583
584 for (node = avtab_search_node(ctab, key); node;
585 node = avtab_search_node_next(node, key->specified)) {
586 if ((u16)(AVTAB_ALLOWED | AVTAB_ENABLED) ==
587 (node->key.specified & (AVTAB_ALLOWED | AVTAB_ENABLED)))
588 avd->allowed |= node->datum.u.data;
589 if ((u16)(AVTAB_AUDITDENY | AVTAB_ENABLED) ==
590 (node->key.specified & (AVTAB_AUDITDENY | AVTAB_ENABLED)))
591 /* Since a '0' in an auditdeny mask represents a
592 * permission we do NOT want to audit (dontaudit), we use
593 * the '&' operand to ensure that all '0's in the mask
594 * are retained (much unlike the allow and auditallow cases).
595 */
596 avd->auditdeny &= node->datum.u.data;
597 if ((u16)(AVTAB_AUDITALLOW | AVTAB_ENABLED) ==
598 (node->key.specified & (AVTAB_AUDITALLOW | AVTAB_ENABLED)))
599 avd->auditallow |= node->datum.u.data;
600 if (xperms && (node->key.specified & AVTAB_ENABLED) &&
601 (node->key.specified & AVTAB_XPERMS))
602 services_compute_xperms_drivers(xperms, node);
603 }
604}
605
606static int cond_dup_av_list(struct cond_av_list *new,
607 const struct cond_av_list *orig,
608 struct avtab *avtab)
609{
610 u32 i;
611
612 memset(new, 0, sizeof(*new));
613
614 new->nodes = kcalloc(orig->len, sizeof(*new->nodes), GFP_KERNEL);
615 if (!new->nodes)
616 return -ENOMEM;
617
618 for (i = 0; i < orig->len; i++) {
619 new->nodes[i] = avtab_insert_nonunique(
620 avtab, &orig->nodes[i]->key, &orig->nodes[i]->datum);
621 if (!new->nodes[i])
622 return -ENOMEM;
623 new->len++;
624 }
625
626 return 0;
627}
628
629static int duplicate_policydb_cond_list(struct policydb *newp,
630 const struct policydb *origp)
631{
632 int rc;
633 u32 i;
634
635 rc = avtab_alloc_dup(&newp->te_cond_avtab, &origp->te_cond_avtab);
636 if (rc)
637 return rc;
638
639 newp->cond_list_len = 0;
640 newp->cond_list = kcalloc(origp->cond_list_len,
641 sizeof(*newp->cond_list), GFP_KERNEL);
642 if (!newp->cond_list)
643 goto error;
644
645 for (i = 0; i < origp->cond_list_len; i++) {
646 struct cond_node *newn = &newp->cond_list[i];
647 const struct cond_node *orign = &origp->cond_list[i];
648
649 newp->cond_list_len++;
650
651 newn->cur_state = orign->cur_state;
652 newn->expr.nodes =
653 kmemdup(orign->expr.nodes,
654 orign->expr.len * sizeof(*orign->expr.nodes),
655 GFP_KERNEL);
656 if (!newn->expr.nodes)
657 goto error;
658
659 newn->expr.len = orign->expr.len;
660
661 rc = cond_dup_av_list(&newn->true_list, &orign->true_list,
662 &newp->te_cond_avtab);
663 if (rc)
664 goto error;
665
666 rc = cond_dup_av_list(&newn->false_list, &orign->false_list,
667 &newp->te_cond_avtab);
668 if (rc)
669 goto error;
670 }
671
672 return 0;
673
674error:
675 avtab_destroy(&newp->te_cond_avtab);
676 cond_list_destroy(newp);
677 return -ENOMEM;
678}
679
680static int cond_bools_destroy(void *key, void *datum, void *args)
681{
682 /* key was not copied so no need to free here */
683 kfree(datum);
684 return 0;
685}
686
687static int cond_bools_copy(struct hashtab_node *new,
688 const struct hashtab_node *orig, void *args)
689{
690 struct cond_bool_datum *datum;
691
692 datum = kmemdup(orig->datum, sizeof(struct cond_bool_datum),
693 GFP_KERNEL);
694 if (!datum)
695 return -ENOMEM;
696
697 new->key = orig->key; /* No need to copy, never modified */
698 new->datum = datum;
699 return 0;
700}
701
702static int cond_bools_index(void *key, void *datum, void *args)
703{
704 struct cond_bool_datum *booldatum, **cond_bool_array;
705
706 booldatum = datum;
707 cond_bool_array = args;
708 cond_bool_array[booldatum->value - 1] = booldatum;
709
710 return 0;
711}
712
713static int duplicate_policydb_bools(struct policydb *newdb,
714 const struct policydb *orig)
715{
716 struct cond_bool_datum **cond_bool_array;
717 int rc;
718
719 cond_bool_array = kmalloc_array(orig->p_bools.nprim,
720 sizeof(*orig->bool_val_to_struct),
721 GFP_KERNEL);
722 if (!cond_bool_array)
723 return -ENOMEM;
724
725 rc = hashtab_duplicate(&newdb->p_bools.table, &orig->p_bools.table,
726 cond_bools_copy, cond_bools_destroy, NULL);
727 if (rc) {
728 kfree(cond_bool_array);
729 return -ENOMEM;
730 }
731
732 hashtab_map(&newdb->p_bools.table, cond_bools_index, cond_bool_array);
733 newdb->bool_val_to_struct = cond_bool_array;
734
735 newdb->p_bools.nprim = orig->p_bools.nprim;
736
737 return 0;
738}
739
740void cond_policydb_destroy_dup(struct policydb *p)
741{
742 hashtab_map(&p->p_bools.table, cond_bools_destroy, NULL);
743 hashtab_destroy(&p->p_bools.table);
744 cond_policydb_destroy(p);
745}
746
747int cond_policydb_dup(struct policydb *new, const struct policydb *orig)
748{
749 cond_policydb_init(new);
750
751 if (duplicate_policydb_bools(new, orig))
752 return -ENOMEM;
753
754 if (duplicate_policydb_cond_list(new, orig)) {
755 cond_policydb_destroy_dup(new);
756 return -ENOMEM;
757 }
758
759 return 0;
760}