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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}
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}