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