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