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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 = kmalloc_array(p->p_bools.nprim,
180 sizeof(*p->bool_val_to_struct),
181 GFP_KERNEL);
182 if (!p->bool_val_to_struct)
183 return -ENOMEM;
184 return 0;
185}
186
187int cond_destroy_bool(void *key, void *datum, void *p)
188{
189 kfree(key);
190 kfree(datum);
191 return 0;
192}
193
194int cond_index_bool(void *key, void *datum, void *datap)
195{
196 struct policydb *p;
197 struct cond_bool_datum *booldatum;
198 struct flex_array *fa;
199
200 booldatum = datum;
201 p = datap;
202
203 if (!booldatum->value || booldatum->value > p->p_bools.nprim)
204 return -EINVAL;
205
206 fa = p->sym_val_to_name[SYM_BOOLS];
207 if (flex_array_put_ptr(fa, booldatum->value - 1, key,
208 GFP_KERNEL | __GFP_ZERO))
209 BUG();
210 p->bool_val_to_struct[booldatum->value - 1] = booldatum;
211
212 return 0;
213}
214
215static int bool_isvalid(struct cond_bool_datum *b)
216{
217 if (!(b->state == 0 || b->state == 1))
218 return 0;
219 return 1;
220}
221
222int cond_read_bool(struct policydb *p, struct hashtab *h, void *fp)
223{
224 char *key = NULL;
225 struct cond_bool_datum *booldatum;
226 __le32 buf[3];
227 u32 len;
228 int rc;
229
230 booldatum = kzalloc(sizeof(*booldatum), GFP_KERNEL);
231 if (!booldatum)
232 return -ENOMEM;
233
234 rc = next_entry(buf, fp, sizeof buf);
235 if (rc)
236 goto err;
237
238 booldatum->value = le32_to_cpu(buf[0]);
239 booldatum->state = le32_to_cpu(buf[1]);
240
241 rc = -EINVAL;
242 if (!bool_isvalid(booldatum))
243 goto err;
244
245 len = le32_to_cpu(buf[2]);
246 if (((len == 0) || (len == (u32)-1)))
247 goto err;
248
249 rc = -ENOMEM;
250 key = kmalloc(len + 1, GFP_KERNEL);
251 if (!key)
252 goto err;
253 rc = next_entry(key, fp, len);
254 if (rc)
255 goto err;
256 key[len] = '\0';
257 rc = hashtab_insert(h, key, booldatum);
258 if (rc)
259 goto err;
260
261 return 0;
262err:
263 cond_destroy_bool(key, booldatum, NULL);
264 return rc;
265}
266
267struct cond_insertf_data {
268 struct policydb *p;
269 struct cond_av_list *other;
270 struct cond_av_list *head;
271 struct cond_av_list *tail;
272};
273
274static int cond_insertf(struct avtab *a, struct avtab_key *k, struct avtab_datum *d, void *ptr)
275{
276 struct cond_insertf_data *data = ptr;
277 struct policydb *p = data->p;
278 struct cond_av_list *other = data->other, *list, *cur;
279 struct avtab_node *node_ptr;
280 u8 found;
281 int rc = -EINVAL;
282
283 /*
284 * For type rules we have to make certain there aren't any
285 * conflicting rules by searching the te_avtab and the
286 * cond_te_avtab.
287 */
288 if (k->specified & AVTAB_TYPE) {
289 if (avtab_search(&p->te_avtab, k)) {
290 printk(KERN_ERR "SELinux: type rule already exists outside of a conditional.\n");
291 goto err;
292 }
293 /*
294 * If we are reading the false list other will be a pointer to
295 * the true list. We can have duplicate entries if there is only
296 * 1 other entry and it is in our true list.
297 *
298 * If we are reading the true list (other == NULL) there shouldn't
299 * be any other entries.
300 */
301 if (other) {
302 node_ptr = avtab_search_node(&p->te_cond_avtab, k);
303 if (node_ptr) {
304 if (avtab_search_node_next(node_ptr, k->specified)) {
305 printk(KERN_ERR "SELinux: too many conflicting type rules.\n");
306 goto err;
307 }
308 found = 0;
309 for (cur = other; cur; cur = cur->next) {
310 if (cur->node == node_ptr) {
311 found = 1;
312 break;
313 }
314 }
315 if (!found) {
316 printk(KERN_ERR "SELinux: conflicting type rules.\n");
317 goto err;
318 }
319 }
320 } else {
321 if (avtab_search(&p->te_cond_avtab, k)) {
322 printk(KERN_ERR "SELinux: conflicting type rules when adding type rule for true.\n");
323 goto err;
324 }
325 }
326 }
327
328 node_ptr = avtab_insert_nonunique(&p->te_cond_avtab, k, d);
329 if (!node_ptr) {
330 printk(KERN_ERR "SELinux: could not insert rule.\n");
331 rc = -ENOMEM;
332 goto err;
333 }
334
335 list = kzalloc(sizeof(*list), GFP_KERNEL);
336 if (!list) {
337 rc = -ENOMEM;
338 goto err;
339 }
340
341 list->node = node_ptr;
342 if (!data->head)
343 data->head = list;
344 else
345 data->tail->next = list;
346 data->tail = list;
347 return 0;
348
349err:
350 cond_av_list_destroy(data->head);
351 data->head = NULL;
352 return rc;
353}
354
355static int cond_read_av_list(struct policydb *p, void *fp, struct cond_av_list **ret_list, struct cond_av_list *other)
356{
357 int i, rc;
358 __le32 buf[1];
359 u32 len;
360 struct cond_insertf_data data;
361
362 *ret_list = NULL;
363
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(*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(*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}
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 return 0;
173}
174
175int cond_destroy_bool(void *key, void *datum, void *p)
176{
177 kfree(key);
178 kfree(datum);
179 return 0;
180}
181
182int cond_index_bool(void *key, void *datum, void *datap)
183{
184 struct policydb *p;
185 struct cond_bool_datum *booldatum;
186
187 booldatum = datum;
188 p = datap;
189
190 if (!booldatum->value || booldatum->value > p->p_bools.nprim)
191 return -EINVAL;
192
193 p->sym_val_to_name[SYM_BOOLS][booldatum->value - 1] = key;
194 p->bool_val_to_struct[booldatum->value - 1] = booldatum;
195
196 return 0;
197}
198
199static int bool_isvalid(struct cond_bool_datum *b)
200{
201 if (!(b->state == 0 || b->state == 1))
202 return 0;
203 return 1;
204}
205
206int cond_read_bool(struct policydb *p, struct symtab *s, void *fp)
207{
208 char *key = NULL;
209 struct cond_bool_datum *booldatum;
210 __le32 buf[3];
211 u32 len;
212 int rc;
213
214 booldatum = kzalloc(sizeof(*booldatum), GFP_KERNEL);
215 if (!booldatum)
216 return -ENOMEM;
217
218 rc = next_entry(buf, fp, sizeof(buf));
219 if (rc)
220 goto err;
221
222 booldatum->value = le32_to_cpu(buf[0]);
223 booldatum->state = le32_to_cpu(buf[1]);
224
225 rc = -EINVAL;
226 if (!bool_isvalid(booldatum))
227 goto err;
228
229 len = le32_to_cpu(buf[2]);
230 if (((len == 0) || (len == (u32)-1)))
231 goto err;
232
233 rc = -ENOMEM;
234 key = kmalloc(len + 1, GFP_KERNEL);
235 if (!key)
236 goto err;
237 rc = next_entry(key, fp, len);
238 if (rc)
239 goto err;
240 key[len] = '\0';
241 rc = symtab_insert(s, key, booldatum);
242 if (rc)
243 goto err;
244
245 return 0;
246err:
247 cond_destroy_bool(key, booldatum, NULL);
248 return rc;
249}
250
251struct cond_insertf_data {
252 struct policydb *p;
253 struct avtab_node **dst;
254 struct cond_av_list *other;
255};
256
257static int cond_insertf(struct avtab *a, const struct avtab_key *k,
258 const struct avtab_datum *d, void *ptr)
259{
260 struct cond_insertf_data *data = ptr;
261 struct policydb *p = data->p;
262 struct cond_av_list *other = data->other;
263 struct avtab_node *node_ptr;
264 u32 i;
265 bool found;
266
267 /*
268 * For type rules we have to make certain there aren't any
269 * conflicting rules by searching the te_avtab and the
270 * cond_te_avtab.
271 */
272 if (k->specified & AVTAB_TYPE) {
273 if (avtab_search_node(&p->te_avtab, k)) {
274 pr_err("SELinux: type rule already exists outside of a conditional.\n");
275 return -EINVAL;
276 }
277 /*
278 * If we are reading the false list other will be a pointer to
279 * the true list. We can have duplicate entries if there is only
280 * 1 other entry and it is in our true list.
281 *
282 * If we are reading the true list (other == NULL) there shouldn't
283 * be any other entries.
284 */
285 if (other) {
286 node_ptr = avtab_search_node(&p->te_cond_avtab, k);
287 if (node_ptr) {
288 if (avtab_search_node_next(node_ptr,
289 k->specified)) {
290 pr_err("SELinux: too many conflicting type rules.\n");
291 return -EINVAL;
292 }
293 found = false;
294 for (i = 0; i < other->len; i++) {
295 if (other->nodes[i] == node_ptr) {
296 found = true;
297 break;
298 }
299 }
300 if (!found) {
301 pr_err("SELinux: conflicting type rules.\n");
302 return -EINVAL;
303 }
304 }
305 } else {
306 if (avtab_search_node(&p->te_cond_avtab, k)) {
307 pr_err("SELinux: conflicting type rules when adding type rule for true.\n");
308 return -EINVAL;
309 }
310 }
311 }
312
313 node_ptr = avtab_insert_nonunique(&p->te_cond_avtab, k, d);
314 if (!node_ptr) {
315 pr_err("SELinux: could not insert rule.\n");
316 return -ENOMEM;
317 }
318
319 *data->dst = node_ptr;
320 return 0;
321}
322
323static int cond_read_av_list(struct policydb *p, void *fp,
324 struct cond_av_list *list,
325 struct cond_av_list *other)
326{
327 int rc;
328 __le32 buf[1];
329 u32 i, len;
330 struct cond_insertf_data data;
331
332 rc = next_entry(buf, fp, sizeof(u32));
333 if (rc)
334 return rc;
335
336 len = le32_to_cpu(buf[0]);
337 if (len == 0)
338 return 0;
339
340 list->nodes = kcalloc(len, sizeof(*list->nodes), GFP_KERNEL);
341 if (!list->nodes)
342 return -ENOMEM;
343
344 data.p = p;
345 data.other = other;
346 for (i = 0; i < len; i++) {
347 data.dst = &list->nodes[i];
348 rc = avtab_read_item(&p->te_cond_avtab, fp, p, cond_insertf,
349 &data);
350 if (rc) {
351 kfree(list->nodes);
352 list->nodes = NULL;
353 return rc;
354 }
355 }
356
357 list->len = len;
358 return 0;
359}
360
361static int expr_node_isvalid(struct policydb *p, struct cond_expr_node *expr)
362{
363 if (expr->expr_type <= 0 || expr->expr_type > COND_LAST) {
364 pr_err("SELinux: conditional expressions uses unknown operator.\n");
365 return 0;
366 }
367
368 if (expr->boolean > p->p_bools.nprim) {
369 pr_err("SELinux: conditional expressions uses unknown bool.\n");
370 return 0;
371 }
372 return 1;
373}
374
375static int cond_read_node(struct policydb *p, struct cond_node *node, void *fp)
376{
377 __le32 buf[2];
378 u32 i, len;
379 int rc;
380
381 rc = next_entry(buf, fp, sizeof(u32) * 2);
382 if (rc)
383 return rc;
384
385 node->cur_state = le32_to_cpu(buf[0]);
386
387 /* expr */
388 len = le32_to_cpu(buf[1]);
389 node->expr.nodes = kcalloc(len, sizeof(*node->expr.nodes), GFP_KERNEL);
390 if (!node->expr.nodes)
391 return -ENOMEM;
392
393 node->expr.len = len;
394
395 for (i = 0; i < len; i++) {
396 struct cond_expr_node *expr = &node->expr.nodes[i];
397
398 rc = next_entry(buf, fp, sizeof(u32) * 2);
399 if (rc)
400 return rc;
401
402 expr->expr_type = le32_to_cpu(buf[0]);
403 expr->boolean = le32_to_cpu(buf[1]);
404
405 if (!expr_node_isvalid(p, expr))
406 return -EINVAL;
407 }
408
409 rc = cond_read_av_list(p, fp, &node->true_list, NULL);
410 if (rc)
411 return rc;
412 return cond_read_av_list(p, fp, &node->false_list, &node->true_list);
413}
414
415int cond_read_list(struct policydb *p, void *fp)
416{
417 __le32 buf[1];
418 u32 i, len;
419 int rc;
420
421 rc = next_entry(buf, fp, sizeof(buf));
422 if (rc)
423 return rc;
424
425 len = le32_to_cpu(buf[0]);
426
427 p->cond_list = kcalloc(len, sizeof(*p->cond_list), GFP_KERNEL);
428 if (!p->cond_list)
429 return -ENOMEM;
430
431 rc = avtab_alloc(&(p->te_cond_avtab), p->te_avtab.nel);
432 if (rc)
433 goto err;
434
435 p->cond_list_len = len;
436
437 for (i = 0; i < len; i++) {
438 rc = cond_read_node(p, &p->cond_list[i], fp);
439 if (rc)
440 goto err;
441 }
442 return 0;
443err:
444 cond_list_destroy(p);
445 return rc;
446}
447
448int cond_write_bool(void *vkey, void *datum, void *ptr)
449{
450 char *key = vkey;
451 struct cond_bool_datum *booldatum = datum;
452 struct policy_data *pd = ptr;
453 void *fp = pd->fp;
454 __le32 buf[3];
455 u32 len;
456 int rc;
457
458 len = strlen(key);
459 buf[0] = cpu_to_le32(booldatum->value);
460 buf[1] = cpu_to_le32(booldatum->state);
461 buf[2] = cpu_to_le32(len);
462 rc = put_entry(buf, sizeof(u32), 3, fp);
463 if (rc)
464 return rc;
465 rc = put_entry(key, 1, len, fp);
466 if (rc)
467 return rc;
468 return 0;
469}
470
471/*
472 * cond_write_cond_av_list doesn't write out the av_list nodes.
473 * Instead it writes out the key/value pairs from the avtab. This
474 * is necessary because there is no way to uniquely identifying rules
475 * in the avtab so it is not possible to associate individual rules
476 * in the avtab with a conditional without saving them as part of
477 * the conditional. This means that the avtab with the conditional
478 * rules will not be saved but will be rebuilt on policy load.
479 */
480static int cond_write_av_list(struct policydb *p, struct cond_av_list *list,
481 struct policy_file *fp)
482{
483 __le32 buf[1];
484 u32 i;
485 int rc;
486
487 buf[0] = cpu_to_le32(list->len);
488 rc = put_entry(buf, sizeof(u32), 1, fp);
489 if (rc)
490 return rc;
491
492 for (i = 0; i < list->len; i++) {
493 rc = avtab_write_item(p, list->nodes[i], fp);
494 if (rc)
495 return rc;
496 }
497
498 return 0;
499}
500
501static int cond_write_node(struct policydb *p, struct cond_node *node,
502 struct policy_file *fp)
503{
504 __le32 buf[2];
505 int rc;
506 u32 i;
507
508 buf[0] = cpu_to_le32(node->cur_state);
509 rc = put_entry(buf, sizeof(u32), 1, fp);
510 if (rc)
511 return rc;
512
513 buf[0] = cpu_to_le32(node->expr.len);
514 rc = put_entry(buf, sizeof(u32), 1, fp);
515 if (rc)
516 return rc;
517
518 for (i = 0; i < node->expr.len; i++) {
519 buf[0] = cpu_to_le32(node->expr.nodes[i].expr_type);
520 buf[1] = cpu_to_le32(node->expr.nodes[i].boolean);
521 rc = put_entry(buf, sizeof(u32), 2, fp);
522 if (rc)
523 return rc;
524 }
525
526 rc = cond_write_av_list(p, &node->true_list, fp);
527 if (rc)
528 return rc;
529 rc = cond_write_av_list(p, &node->false_list, fp);
530 if (rc)
531 return rc;
532
533 return 0;
534}
535
536int cond_write_list(struct policydb *p, void *fp)
537{
538 u32 i;
539 __le32 buf[1];
540 int rc;
541
542 buf[0] = cpu_to_le32(p->cond_list_len);
543 rc = put_entry(buf, sizeof(u32), 1, fp);
544 if (rc)
545 return rc;
546
547 for (i = 0; i < p->cond_list_len; i++) {
548 rc = cond_write_node(p, &p->cond_list[i], fp);
549 if (rc)
550 return rc;
551 }
552
553 return 0;
554}
555
556void cond_compute_xperms(struct avtab *ctab, struct avtab_key *key,
557 struct extended_perms_decision *xpermd)
558{
559 struct avtab_node *node;
560
561 if (!ctab || !key || !xpermd)
562 return;
563
564 for (node = avtab_search_node(ctab, key); node;
565 node = avtab_search_node_next(node, key->specified)) {
566 if (node->key.specified & AVTAB_ENABLED)
567 services_compute_xperms_decision(xpermd, node);
568 }
569}
570/* Determine whether additional permissions are granted by the conditional
571 * av table, and if so, add them to the result
572 */
573void cond_compute_av(struct avtab *ctab, struct avtab_key *key,
574 struct av_decision *avd, struct extended_perms *xperms)
575{
576 struct avtab_node *node;
577
578 if (!ctab || !key || !avd)
579 return;
580
581 for (node = avtab_search_node(ctab, key); node;
582 node = avtab_search_node_next(node, key->specified)) {
583 if ((u16)(AVTAB_ALLOWED | AVTAB_ENABLED) ==
584 (node->key.specified & (AVTAB_ALLOWED | AVTAB_ENABLED)))
585 avd->allowed |= node->datum.u.data;
586 if ((u16)(AVTAB_AUDITDENY | AVTAB_ENABLED) ==
587 (node->key.specified & (AVTAB_AUDITDENY | AVTAB_ENABLED)))
588 /* Since a '0' in an auditdeny mask represents a
589 * permission we do NOT want to audit (dontaudit), we use
590 * the '&' operand to ensure that all '0's in the mask
591 * are retained (much unlike the allow and auditallow cases).
592 */
593 avd->auditdeny &= node->datum.u.data;
594 if ((u16)(AVTAB_AUDITALLOW | AVTAB_ENABLED) ==
595 (node->key.specified & (AVTAB_AUDITALLOW | AVTAB_ENABLED)))
596 avd->auditallow |= node->datum.u.data;
597 if (xperms && (node->key.specified & AVTAB_ENABLED) &&
598 (node->key.specified & AVTAB_XPERMS))
599 services_compute_xperms_drivers(xperms, node);
600 }
601}
602
603static int cond_dup_av_list(struct cond_av_list *new, struct cond_av_list *orig,
604 struct avtab *avtab)
605{
606 u32 i;
607
608 memset(new, 0, sizeof(*new));
609
610 new->nodes = kcalloc(orig->len, sizeof(*new->nodes), GFP_KERNEL);
611 if (!new->nodes)
612 return -ENOMEM;
613
614 for (i = 0; i < orig->len; i++) {
615 new->nodes[i] = avtab_insert_nonunique(
616 avtab, &orig->nodes[i]->key, &orig->nodes[i]->datum);
617 if (!new->nodes[i])
618 return -ENOMEM;
619 new->len++;
620 }
621
622 return 0;
623}
624
625static int duplicate_policydb_cond_list(struct policydb *newp,
626 struct policydb *origp)
627{
628 int rc;
629 u32 i;
630
631 rc = avtab_alloc_dup(&newp->te_cond_avtab, &origp->te_cond_avtab);
632 if (rc)
633 return rc;
634
635 newp->cond_list_len = 0;
636 newp->cond_list = kcalloc(origp->cond_list_len,
637 sizeof(*newp->cond_list), GFP_KERNEL);
638 if (!newp->cond_list)
639 goto error;
640
641 for (i = 0; i < origp->cond_list_len; i++) {
642 struct cond_node *newn = &newp->cond_list[i];
643 struct cond_node *orign = &origp->cond_list[i];
644
645 newp->cond_list_len++;
646
647 newn->cur_state = orign->cur_state;
648 newn->expr.nodes =
649 kmemdup(orign->expr.nodes,
650 orign->expr.len * sizeof(*orign->expr.nodes),
651 GFP_KERNEL);
652 if (!newn->expr.nodes)
653 goto error;
654
655 newn->expr.len = orign->expr.len;
656
657 rc = cond_dup_av_list(&newn->true_list, &orign->true_list,
658 &newp->te_cond_avtab);
659 if (rc)
660 goto error;
661
662 rc = cond_dup_av_list(&newn->false_list, &orign->false_list,
663 &newp->te_cond_avtab);
664 if (rc)
665 goto error;
666 }
667
668 return 0;
669
670error:
671 avtab_destroy(&newp->te_cond_avtab);
672 cond_list_destroy(newp);
673 return -ENOMEM;
674}
675
676static int cond_bools_destroy(void *key, void *datum, void *args)
677{
678 /* key was not copied so no need to free here */
679 kfree(datum);
680 return 0;
681}
682
683static int cond_bools_copy(struct hashtab_node *new, struct hashtab_node *orig,
684 void *args)
685{
686 struct cond_bool_datum *datum;
687
688 datum = kmemdup(orig->datum, sizeof(struct cond_bool_datum),
689 GFP_KERNEL);
690 if (!datum)
691 return -ENOMEM;
692
693 new->key = orig->key; /* No need to copy, never modified */
694 new->datum = datum;
695 return 0;
696}
697
698static int cond_bools_index(void *key, void *datum, void *args)
699{
700 struct cond_bool_datum *booldatum, **cond_bool_array;
701
702 booldatum = datum;
703 cond_bool_array = args;
704 cond_bool_array[booldatum->value - 1] = booldatum;
705
706 return 0;
707}
708
709static int duplicate_policydb_bools(struct policydb *newdb,
710 struct policydb *orig)
711{
712 struct cond_bool_datum **cond_bool_array;
713 int rc;
714
715 cond_bool_array = kmalloc_array(orig->p_bools.nprim,
716 sizeof(*orig->bool_val_to_struct),
717 GFP_KERNEL);
718 if (!cond_bool_array)
719 return -ENOMEM;
720
721 rc = hashtab_duplicate(&newdb->p_bools.table, &orig->p_bools.table,
722 cond_bools_copy, cond_bools_destroy, NULL);
723 if (rc) {
724 kfree(cond_bool_array);
725 return -ENOMEM;
726 }
727
728 hashtab_map(&newdb->p_bools.table, cond_bools_index, cond_bool_array);
729 newdb->bool_val_to_struct = cond_bool_array;
730
731 newdb->p_bools.nprim = orig->p_bools.nprim;
732
733 return 0;
734}
735
736void cond_policydb_destroy_dup(struct policydb *p)
737{
738 hashtab_map(&p->p_bools.table, cond_bools_destroy, NULL);
739 hashtab_destroy(&p->p_bools.table);
740 cond_policydb_destroy(p);
741}
742
743int cond_policydb_dup(struct policydb *new, struct policydb *orig)
744{
745 cond_policydb_init(new);
746
747 if (duplicate_policydb_bools(new, orig))
748 return -ENOMEM;
749
750 if (duplicate_policydb_cond_list(new, orig)) {
751 cond_policydb_destroy_dup(new);
752 return -ENOMEM;
753 }
754
755 return 0;
756}