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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/* 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}