xref: /openbmc/linux/security/selinux/selinuxfs.c (revision e23feb16)
1 /* Updated: Karl MacMillan <kmacmillan@tresys.com>
2  *
3  *	Added conditional policy language extensions
4  *
5  *  Updated: Hewlett-Packard <paul@paul-moore.com>
6  *
7  *	Added support for the policy capability bitmap
8  *
9  * Copyright (C) 2007 Hewlett-Packard Development Company, L.P.
10  * Copyright (C) 2003 - 2004 Tresys Technology, LLC
11  * Copyright (C) 2004 Red Hat, Inc., James Morris <jmorris@redhat.com>
12  *	This program is free software; you can redistribute it and/or modify
13  *	it under the terms of the GNU General Public License as published by
14  *	the Free Software Foundation, version 2.
15  */
16 
17 #include <linux/kernel.h>
18 #include <linux/pagemap.h>
19 #include <linux/slab.h>
20 #include <linux/vmalloc.h>
21 #include <linux/fs.h>
22 #include <linux/mutex.h>
23 #include <linux/init.h>
24 #include <linux/string.h>
25 #include <linux/security.h>
26 #include <linux/major.h>
27 #include <linux/seq_file.h>
28 #include <linux/percpu.h>
29 #include <linux/audit.h>
30 #include <linux/uaccess.h>
31 #include <linux/kobject.h>
32 #include <linux/ctype.h>
33 
34 /* selinuxfs pseudo filesystem for exporting the security policy API.
35    Based on the proc code and the fs/nfsd/nfsctl.c code. */
36 
37 #include "flask.h"
38 #include "avc.h"
39 #include "avc_ss.h"
40 #include "security.h"
41 #include "objsec.h"
42 #include "conditional.h"
43 
44 /* Policy capability filenames */
45 static char *policycap_names[] = {
46 	"network_peer_controls",
47 	"open_perms"
48 };
49 
50 unsigned int selinux_checkreqprot = CONFIG_SECURITY_SELINUX_CHECKREQPROT_VALUE;
51 
52 static int __init checkreqprot_setup(char *str)
53 {
54 	unsigned long checkreqprot;
55 	if (!strict_strtoul(str, 0, &checkreqprot))
56 		selinux_checkreqprot = checkreqprot ? 1 : 0;
57 	return 1;
58 }
59 __setup("checkreqprot=", checkreqprot_setup);
60 
61 static DEFINE_MUTEX(sel_mutex);
62 
63 /* global data for booleans */
64 static struct dentry *bool_dir;
65 static int bool_num;
66 static char **bool_pending_names;
67 static int *bool_pending_values;
68 
69 /* global data for classes */
70 static struct dentry *class_dir;
71 static unsigned long last_class_ino;
72 
73 static char policy_opened;
74 
75 /* global data for policy capabilities */
76 static struct dentry *policycap_dir;
77 
78 /* Check whether a task is allowed to use a security operation. */
79 static int task_has_security(struct task_struct *tsk,
80 			     u32 perms)
81 {
82 	const struct task_security_struct *tsec;
83 	u32 sid = 0;
84 
85 	rcu_read_lock();
86 	tsec = __task_cred(tsk)->security;
87 	if (tsec)
88 		sid = tsec->sid;
89 	rcu_read_unlock();
90 	if (!tsec)
91 		return -EACCES;
92 
93 	return avc_has_perm(sid, SECINITSID_SECURITY,
94 			    SECCLASS_SECURITY, perms, NULL);
95 }
96 
97 enum sel_inos {
98 	SEL_ROOT_INO = 2,
99 	SEL_LOAD,	/* load policy */
100 	SEL_ENFORCE,	/* get or set enforcing status */
101 	SEL_CONTEXT,	/* validate context */
102 	SEL_ACCESS,	/* compute access decision */
103 	SEL_CREATE,	/* compute create labeling decision */
104 	SEL_RELABEL,	/* compute relabeling decision */
105 	SEL_USER,	/* compute reachable user contexts */
106 	SEL_POLICYVERS,	/* return policy version for this kernel */
107 	SEL_COMMIT_BOOLS, /* commit new boolean values */
108 	SEL_MLS,	/* return if MLS policy is enabled */
109 	SEL_DISABLE,	/* disable SELinux until next reboot */
110 	SEL_MEMBER,	/* compute polyinstantiation membership decision */
111 	SEL_CHECKREQPROT, /* check requested protection, not kernel-applied one */
112 	SEL_COMPAT_NET,	/* whether to use old compat network packet controls */
113 	SEL_REJECT_UNKNOWN, /* export unknown reject handling to userspace */
114 	SEL_DENY_UNKNOWN, /* export unknown deny handling to userspace */
115 	SEL_STATUS,	/* export current status using mmap() */
116 	SEL_POLICY,	/* allow userspace to read the in kernel policy */
117 	SEL_INO_NEXT,	/* The next inode number to use */
118 };
119 
120 static unsigned long sel_last_ino = SEL_INO_NEXT - 1;
121 
122 #define SEL_INITCON_INO_OFFSET		0x01000000
123 #define SEL_BOOL_INO_OFFSET		0x02000000
124 #define SEL_CLASS_INO_OFFSET		0x04000000
125 #define SEL_POLICYCAP_INO_OFFSET	0x08000000
126 #define SEL_INO_MASK			0x00ffffff
127 
128 #define TMPBUFLEN	12
129 static ssize_t sel_read_enforce(struct file *filp, char __user *buf,
130 				size_t count, loff_t *ppos)
131 {
132 	char tmpbuf[TMPBUFLEN];
133 	ssize_t length;
134 
135 	length = scnprintf(tmpbuf, TMPBUFLEN, "%d", selinux_enforcing);
136 	return simple_read_from_buffer(buf, count, ppos, tmpbuf, length);
137 }
138 
139 #ifdef CONFIG_SECURITY_SELINUX_DEVELOP
140 static ssize_t sel_write_enforce(struct file *file, const char __user *buf,
141 				 size_t count, loff_t *ppos)
142 
143 {
144 	char *page = NULL;
145 	ssize_t length;
146 	int new_value;
147 
148 	length = -ENOMEM;
149 	if (count >= PAGE_SIZE)
150 		goto out;
151 
152 	/* No partial writes. */
153 	length = EINVAL;
154 	if (*ppos != 0)
155 		goto out;
156 
157 	length = -ENOMEM;
158 	page = (char *)get_zeroed_page(GFP_KERNEL);
159 	if (!page)
160 		goto out;
161 
162 	length = -EFAULT;
163 	if (copy_from_user(page, buf, count))
164 		goto out;
165 
166 	length = -EINVAL;
167 	if (sscanf(page, "%d", &new_value) != 1)
168 		goto out;
169 
170 	if (new_value != selinux_enforcing) {
171 		length = task_has_security(current, SECURITY__SETENFORCE);
172 		if (length)
173 			goto out;
174 		audit_log(current->audit_context, GFP_KERNEL, AUDIT_MAC_STATUS,
175 			"enforcing=%d old_enforcing=%d auid=%u ses=%u",
176 			new_value, selinux_enforcing,
177 			from_kuid(&init_user_ns, audit_get_loginuid(current)),
178 			audit_get_sessionid(current));
179 		selinux_enforcing = new_value;
180 		if (selinux_enforcing)
181 			avc_ss_reset(0);
182 		selnl_notify_setenforce(selinux_enforcing);
183 		selinux_status_update_setenforce(selinux_enforcing);
184 	}
185 	length = count;
186 out:
187 	free_page((unsigned long) page);
188 	return length;
189 }
190 #else
191 #define sel_write_enforce NULL
192 #endif
193 
194 static const struct file_operations sel_enforce_ops = {
195 	.read		= sel_read_enforce,
196 	.write		= sel_write_enforce,
197 	.llseek		= generic_file_llseek,
198 };
199 
200 static ssize_t sel_read_handle_unknown(struct file *filp, char __user *buf,
201 					size_t count, loff_t *ppos)
202 {
203 	char tmpbuf[TMPBUFLEN];
204 	ssize_t length;
205 	ino_t ino = file_inode(filp)->i_ino;
206 	int handle_unknown = (ino == SEL_REJECT_UNKNOWN) ?
207 		security_get_reject_unknown() : !security_get_allow_unknown();
208 
209 	length = scnprintf(tmpbuf, TMPBUFLEN, "%d", handle_unknown);
210 	return simple_read_from_buffer(buf, count, ppos, tmpbuf, length);
211 }
212 
213 static const struct file_operations sel_handle_unknown_ops = {
214 	.read		= sel_read_handle_unknown,
215 	.llseek		= generic_file_llseek,
216 };
217 
218 static int sel_open_handle_status(struct inode *inode, struct file *filp)
219 {
220 	struct page    *status = selinux_kernel_status_page();
221 
222 	if (!status)
223 		return -ENOMEM;
224 
225 	filp->private_data = status;
226 
227 	return 0;
228 }
229 
230 static ssize_t sel_read_handle_status(struct file *filp, char __user *buf,
231 				      size_t count, loff_t *ppos)
232 {
233 	struct page    *status = filp->private_data;
234 
235 	BUG_ON(!status);
236 
237 	return simple_read_from_buffer(buf, count, ppos,
238 				       page_address(status),
239 				       sizeof(struct selinux_kernel_status));
240 }
241 
242 static int sel_mmap_handle_status(struct file *filp,
243 				  struct vm_area_struct *vma)
244 {
245 	struct page    *status = filp->private_data;
246 	unsigned long	size = vma->vm_end - vma->vm_start;
247 
248 	BUG_ON(!status);
249 
250 	/* only allows one page from the head */
251 	if (vma->vm_pgoff > 0 || size != PAGE_SIZE)
252 		return -EIO;
253 	/* disallow writable mapping */
254 	if (vma->vm_flags & VM_WRITE)
255 		return -EPERM;
256 	/* disallow mprotect() turns it into writable */
257 	vma->vm_flags &= ~VM_MAYWRITE;
258 
259 	return remap_pfn_range(vma, vma->vm_start,
260 			       page_to_pfn(status),
261 			       size, vma->vm_page_prot);
262 }
263 
264 static const struct file_operations sel_handle_status_ops = {
265 	.open		= sel_open_handle_status,
266 	.read		= sel_read_handle_status,
267 	.mmap		= sel_mmap_handle_status,
268 	.llseek		= generic_file_llseek,
269 };
270 
271 #ifdef CONFIG_SECURITY_SELINUX_DISABLE
272 static ssize_t sel_write_disable(struct file *file, const char __user *buf,
273 				 size_t count, loff_t *ppos)
274 
275 {
276 	char *page = NULL;
277 	ssize_t length;
278 	int new_value;
279 
280 	length = -ENOMEM;
281 	if (count >= PAGE_SIZE)
282 		goto out;
283 
284 	/* No partial writes. */
285 	length = -EINVAL;
286 	if (*ppos != 0)
287 		goto out;
288 
289 	length = -ENOMEM;
290 	page = (char *)get_zeroed_page(GFP_KERNEL);
291 	if (!page)
292 		goto out;
293 
294 	length = -EFAULT;
295 	if (copy_from_user(page, buf, count))
296 		goto out;
297 
298 	length = -EINVAL;
299 	if (sscanf(page, "%d", &new_value) != 1)
300 		goto out;
301 
302 	if (new_value) {
303 		length = selinux_disable();
304 		if (length)
305 			goto out;
306 		audit_log(current->audit_context, GFP_KERNEL, AUDIT_MAC_STATUS,
307 			"selinux=0 auid=%u ses=%u",
308 			from_kuid(&init_user_ns, audit_get_loginuid(current)),
309 			audit_get_sessionid(current));
310 	}
311 
312 	length = count;
313 out:
314 	free_page((unsigned long) page);
315 	return length;
316 }
317 #else
318 #define sel_write_disable NULL
319 #endif
320 
321 static const struct file_operations sel_disable_ops = {
322 	.write		= sel_write_disable,
323 	.llseek		= generic_file_llseek,
324 };
325 
326 static ssize_t sel_read_policyvers(struct file *filp, char __user *buf,
327 				   size_t count, loff_t *ppos)
328 {
329 	char tmpbuf[TMPBUFLEN];
330 	ssize_t length;
331 
332 	length = scnprintf(tmpbuf, TMPBUFLEN, "%u", POLICYDB_VERSION_MAX);
333 	return simple_read_from_buffer(buf, count, ppos, tmpbuf, length);
334 }
335 
336 static const struct file_operations sel_policyvers_ops = {
337 	.read		= sel_read_policyvers,
338 	.llseek		= generic_file_llseek,
339 };
340 
341 /* declaration for sel_write_load */
342 static int sel_make_bools(void);
343 static int sel_make_classes(void);
344 static int sel_make_policycap(void);
345 
346 /* declaration for sel_make_class_dirs */
347 static struct dentry *sel_make_dir(struct dentry *dir, const char *name,
348 			unsigned long *ino);
349 
350 static ssize_t sel_read_mls(struct file *filp, char __user *buf,
351 				size_t count, loff_t *ppos)
352 {
353 	char tmpbuf[TMPBUFLEN];
354 	ssize_t length;
355 
356 	length = scnprintf(tmpbuf, TMPBUFLEN, "%d",
357 			   security_mls_enabled());
358 	return simple_read_from_buffer(buf, count, ppos, tmpbuf, length);
359 }
360 
361 static const struct file_operations sel_mls_ops = {
362 	.read		= sel_read_mls,
363 	.llseek		= generic_file_llseek,
364 };
365 
366 struct policy_load_memory {
367 	size_t len;
368 	void *data;
369 };
370 
371 static int sel_open_policy(struct inode *inode, struct file *filp)
372 {
373 	struct policy_load_memory *plm = NULL;
374 	int rc;
375 
376 	BUG_ON(filp->private_data);
377 
378 	mutex_lock(&sel_mutex);
379 
380 	rc = task_has_security(current, SECURITY__READ_POLICY);
381 	if (rc)
382 		goto err;
383 
384 	rc = -EBUSY;
385 	if (policy_opened)
386 		goto err;
387 
388 	rc = -ENOMEM;
389 	plm = kzalloc(sizeof(*plm), GFP_KERNEL);
390 	if (!plm)
391 		goto err;
392 
393 	if (i_size_read(inode) != security_policydb_len()) {
394 		mutex_lock(&inode->i_mutex);
395 		i_size_write(inode, security_policydb_len());
396 		mutex_unlock(&inode->i_mutex);
397 	}
398 
399 	rc = security_read_policy(&plm->data, &plm->len);
400 	if (rc)
401 		goto err;
402 
403 	policy_opened = 1;
404 
405 	filp->private_data = plm;
406 
407 	mutex_unlock(&sel_mutex);
408 
409 	return 0;
410 err:
411 	mutex_unlock(&sel_mutex);
412 
413 	if (plm)
414 		vfree(plm->data);
415 	kfree(plm);
416 	return rc;
417 }
418 
419 static int sel_release_policy(struct inode *inode, struct file *filp)
420 {
421 	struct policy_load_memory *plm = filp->private_data;
422 
423 	BUG_ON(!plm);
424 
425 	policy_opened = 0;
426 
427 	vfree(plm->data);
428 	kfree(plm);
429 
430 	return 0;
431 }
432 
433 static ssize_t sel_read_policy(struct file *filp, char __user *buf,
434 			       size_t count, loff_t *ppos)
435 {
436 	struct policy_load_memory *plm = filp->private_data;
437 	int ret;
438 
439 	mutex_lock(&sel_mutex);
440 
441 	ret = task_has_security(current, SECURITY__READ_POLICY);
442 	if (ret)
443 		goto out;
444 
445 	ret = simple_read_from_buffer(buf, count, ppos, plm->data, plm->len);
446 out:
447 	mutex_unlock(&sel_mutex);
448 	return ret;
449 }
450 
451 static int sel_mmap_policy_fault(struct vm_area_struct *vma,
452 				 struct vm_fault *vmf)
453 {
454 	struct policy_load_memory *plm = vma->vm_file->private_data;
455 	unsigned long offset;
456 	struct page *page;
457 
458 	if (vmf->flags & (FAULT_FLAG_MKWRITE | FAULT_FLAG_WRITE))
459 		return VM_FAULT_SIGBUS;
460 
461 	offset = vmf->pgoff << PAGE_SHIFT;
462 	if (offset >= roundup(plm->len, PAGE_SIZE))
463 		return VM_FAULT_SIGBUS;
464 
465 	page = vmalloc_to_page(plm->data + offset);
466 	get_page(page);
467 
468 	vmf->page = page;
469 
470 	return 0;
471 }
472 
473 static struct vm_operations_struct sel_mmap_policy_ops = {
474 	.fault = sel_mmap_policy_fault,
475 	.page_mkwrite = sel_mmap_policy_fault,
476 };
477 
478 static int sel_mmap_policy(struct file *filp, struct vm_area_struct *vma)
479 {
480 	if (vma->vm_flags & VM_SHARED) {
481 		/* do not allow mprotect to make mapping writable */
482 		vma->vm_flags &= ~VM_MAYWRITE;
483 
484 		if (vma->vm_flags & VM_WRITE)
485 			return -EACCES;
486 	}
487 
488 	vma->vm_flags |= VM_DONTEXPAND | VM_DONTDUMP;
489 	vma->vm_ops = &sel_mmap_policy_ops;
490 
491 	return 0;
492 }
493 
494 static const struct file_operations sel_policy_ops = {
495 	.open		= sel_open_policy,
496 	.read		= sel_read_policy,
497 	.mmap		= sel_mmap_policy,
498 	.release	= sel_release_policy,
499 	.llseek		= generic_file_llseek,
500 };
501 
502 static ssize_t sel_write_load(struct file *file, const char __user *buf,
503 			      size_t count, loff_t *ppos)
504 
505 {
506 	ssize_t length;
507 	void *data = NULL;
508 
509 	mutex_lock(&sel_mutex);
510 
511 	length = task_has_security(current, SECURITY__LOAD_POLICY);
512 	if (length)
513 		goto out;
514 
515 	/* No partial writes. */
516 	length = -EINVAL;
517 	if (*ppos != 0)
518 		goto out;
519 
520 	length = -EFBIG;
521 	if (count > 64 * 1024 * 1024)
522 		goto out;
523 
524 	length = -ENOMEM;
525 	data = vmalloc(count);
526 	if (!data)
527 		goto out;
528 
529 	length = -EFAULT;
530 	if (copy_from_user(data, buf, count) != 0)
531 		goto out;
532 
533 	length = security_load_policy(data, count);
534 	if (length)
535 		goto out;
536 
537 	length = sel_make_bools();
538 	if (length)
539 		goto out1;
540 
541 	length = sel_make_classes();
542 	if (length)
543 		goto out1;
544 
545 	length = sel_make_policycap();
546 	if (length)
547 		goto out1;
548 
549 	length = count;
550 
551 out1:
552 	audit_log(current->audit_context, GFP_KERNEL, AUDIT_MAC_POLICY_LOAD,
553 		"policy loaded auid=%u ses=%u",
554 		from_kuid(&init_user_ns, audit_get_loginuid(current)),
555 		audit_get_sessionid(current));
556 out:
557 	mutex_unlock(&sel_mutex);
558 	vfree(data);
559 	return length;
560 }
561 
562 static const struct file_operations sel_load_ops = {
563 	.write		= sel_write_load,
564 	.llseek		= generic_file_llseek,
565 };
566 
567 static ssize_t sel_write_context(struct file *file, char *buf, size_t size)
568 {
569 	char *canon = NULL;
570 	u32 sid, len;
571 	ssize_t length;
572 
573 	length = task_has_security(current, SECURITY__CHECK_CONTEXT);
574 	if (length)
575 		goto out;
576 
577 	length = security_context_to_sid(buf, size, &sid);
578 	if (length)
579 		goto out;
580 
581 	length = security_sid_to_context(sid, &canon, &len);
582 	if (length)
583 		goto out;
584 
585 	length = -ERANGE;
586 	if (len > SIMPLE_TRANSACTION_LIMIT) {
587 		printk(KERN_ERR "SELinux: %s:  context size (%u) exceeds "
588 			"payload max\n", __func__, len);
589 		goto out;
590 	}
591 
592 	memcpy(buf, canon, len);
593 	length = len;
594 out:
595 	kfree(canon);
596 	return length;
597 }
598 
599 static ssize_t sel_read_checkreqprot(struct file *filp, char __user *buf,
600 				     size_t count, loff_t *ppos)
601 {
602 	char tmpbuf[TMPBUFLEN];
603 	ssize_t length;
604 
605 	length = scnprintf(tmpbuf, TMPBUFLEN, "%u", selinux_checkreqprot);
606 	return simple_read_from_buffer(buf, count, ppos, tmpbuf, length);
607 }
608 
609 static ssize_t sel_write_checkreqprot(struct file *file, const char __user *buf,
610 				      size_t count, loff_t *ppos)
611 {
612 	char *page = NULL;
613 	ssize_t length;
614 	unsigned int new_value;
615 
616 	length = task_has_security(current, SECURITY__SETCHECKREQPROT);
617 	if (length)
618 		goto out;
619 
620 	length = -ENOMEM;
621 	if (count >= PAGE_SIZE)
622 		goto out;
623 
624 	/* No partial writes. */
625 	length = -EINVAL;
626 	if (*ppos != 0)
627 		goto out;
628 
629 	length = -ENOMEM;
630 	page = (char *)get_zeroed_page(GFP_KERNEL);
631 	if (!page)
632 		goto out;
633 
634 	length = -EFAULT;
635 	if (copy_from_user(page, buf, count))
636 		goto out;
637 
638 	length = -EINVAL;
639 	if (sscanf(page, "%u", &new_value) != 1)
640 		goto out;
641 
642 	selinux_checkreqprot = new_value ? 1 : 0;
643 	length = count;
644 out:
645 	free_page((unsigned long) page);
646 	return length;
647 }
648 static const struct file_operations sel_checkreqprot_ops = {
649 	.read		= sel_read_checkreqprot,
650 	.write		= sel_write_checkreqprot,
651 	.llseek		= generic_file_llseek,
652 };
653 
654 /*
655  * Remaining nodes use transaction based IO methods like nfsd/nfsctl.c
656  */
657 static ssize_t sel_write_access(struct file *file, char *buf, size_t size);
658 static ssize_t sel_write_create(struct file *file, char *buf, size_t size);
659 static ssize_t sel_write_relabel(struct file *file, char *buf, size_t size);
660 static ssize_t sel_write_user(struct file *file, char *buf, size_t size);
661 static ssize_t sel_write_member(struct file *file, char *buf, size_t size);
662 
663 static ssize_t (*write_op[])(struct file *, char *, size_t) = {
664 	[SEL_ACCESS] = sel_write_access,
665 	[SEL_CREATE] = sel_write_create,
666 	[SEL_RELABEL] = sel_write_relabel,
667 	[SEL_USER] = sel_write_user,
668 	[SEL_MEMBER] = sel_write_member,
669 	[SEL_CONTEXT] = sel_write_context,
670 };
671 
672 static ssize_t selinux_transaction_write(struct file *file, const char __user *buf, size_t size, loff_t *pos)
673 {
674 	ino_t ino = file_inode(file)->i_ino;
675 	char *data;
676 	ssize_t rv;
677 
678 	if (ino >= ARRAY_SIZE(write_op) || !write_op[ino])
679 		return -EINVAL;
680 
681 	data = simple_transaction_get(file, buf, size);
682 	if (IS_ERR(data))
683 		return PTR_ERR(data);
684 
685 	rv = write_op[ino](file, data, size);
686 	if (rv > 0) {
687 		simple_transaction_set(file, rv);
688 		rv = size;
689 	}
690 	return rv;
691 }
692 
693 static const struct file_operations transaction_ops = {
694 	.write		= selinux_transaction_write,
695 	.read		= simple_transaction_read,
696 	.release	= simple_transaction_release,
697 	.llseek		= generic_file_llseek,
698 };
699 
700 /*
701  * payload - write methods
702  * If the method has a response, the response should be put in buf,
703  * and the length returned.  Otherwise return 0 or and -error.
704  */
705 
706 static ssize_t sel_write_access(struct file *file, char *buf, size_t size)
707 {
708 	char *scon = NULL, *tcon = NULL;
709 	u32 ssid, tsid;
710 	u16 tclass;
711 	struct av_decision avd;
712 	ssize_t length;
713 
714 	length = task_has_security(current, SECURITY__COMPUTE_AV);
715 	if (length)
716 		goto out;
717 
718 	length = -ENOMEM;
719 	scon = kzalloc(size + 1, GFP_KERNEL);
720 	if (!scon)
721 		goto out;
722 
723 	length = -ENOMEM;
724 	tcon = kzalloc(size + 1, GFP_KERNEL);
725 	if (!tcon)
726 		goto out;
727 
728 	length = -EINVAL;
729 	if (sscanf(buf, "%s %s %hu", scon, tcon, &tclass) != 3)
730 		goto out;
731 
732 	length = security_context_to_sid(scon, strlen(scon) + 1, &ssid);
733 	if (length)
734 		goto out;
735 
736 	length = security_context_to_sid(tcon, strlen(tcon) + 1, &tsid);
737 	if (length)
738 		goto out;
739 
740 	security_compute_av_user(ssid, tsid, tclass, &avd);
741 
742 	length = scnprintf(buf, SIMPLE_TRANSACTION_LIMIT,
743 			  "%x %x %x %x %u %x",
744 			  avd.allowed, 0xffffffff,
745 			  avd.auditallow, avd.auditdeny,
746 			  avd.seqno, avd.flags);
747 out:
748 	kfree(tcon);
749 	kfree(scon);
750 	return length;
751 }
752 
753 static ssize_t sel_write_create(struct file *file, char *buf, size_t size)
754 {
755 	char *scon = NULL, *tcon = NULL;
756 	char *namebuf = NULL, *objname = NULL;
757 	u32 ssid, tsid, newsid;
758 	u16 tclass;
759 	ssize_t length;
760 	char *newcon = NULL;
761 	u32 len;
762 	int nargs;
763 
764 	length = task_has_security(current, SECURITY__COMPUTE_CREATE);
765 	if (length)
766 		goto out;
767 
768 	length = -ENOMEM;
769 	scon = kzalloc(size + 1, GFP_KERNEL);
770 	if (!scon)
771 		goto out;
772 
773 	length = -ENOMEM;
774 	tcon = kzalloc(size + 1, GFP_KERNEL);
775 	if (!tcon)
776 		goto out;
777 
778 	length = -ENOMEM;
779 	namebuf = kzalloc(size + 1, GFP_KERNEL);
780 	if (!namebuf)
781 		goto out;
782 
783 	length = -EINVAL;
784 	nargs = sscanf(buf, "%s %s %hu %s", scon, tcon, &tclass, namebuf);
785 	if (nargs < 3 || nargs > 4)
786 		goto out;
787 	if (nargs == 4) {
788 		/*
789 		 * If and when the name of new object to be queried contains
790 		 * either whitespace or multibyte characters, they shall be
791 		 * encoded based on the percentage-encoding rule.
792 		 * If not encoded, the sscanf logic picks up only left-half
793 		 * of the supplied name; splitted by a whitespace unexpectedly.
794 		 */
795 		char   *r, *w;
796 		int     c1, c2;
797 
798 		r = w = namebuf;
799 		do {
800 			c1 = *r++;
801 			if (c1 == '+')
802 				c1 = ' ';
803 			else if (c1 == '%') {
804 				c1 = hex_to_bin(*r++);
805 				if (c1 < 0)
806 					goto out;
807 				c2 = hex_to_bin(*r++);
808 				if (c2 < 0)
809 					goto out;
810 				c1 = (c1 << 4) | c2;
811 			}
812 			*w++ = c1;
813 		} while (c1 != '\0');
814 
815 		objname = namebuf;
816 	}
817 
818 	length = security_context_to_sid(scon, strlen(scon) + 1, &ssid);
819 	if (length)
820 		goto out;
821 
822 	length = security_context_to_sid(tcon, strlen(tcon) + 1, &tsid);
823 	if (length)
824 		goto out;
825 
826 	length = security_transition_sid_user(ssid, tsid, tclass,
827 					      objname, &newsid);
828 	if (length)
829 		goto out;
830 
831 	length = security_sid_to_context(newsid, &newcon, &len);
832 	if (length)
833 		goto out;
834 
835 	length = -ERANGE;
836 	if (len > SIMPLE_TRANSACTION_LIMIT) {
837 		printk(KERN_ERR "SELinux: %s:  context size (%u) exceeds "
838 			"payload max\n", __func__, len);
839 		goto out;
840 	}
841 
842 	memcpy(buf, newcon, len);
843 	length = len;
844 out:
845 	kfree(newcon);
846 	kfree(namebuf);
847 	kfree(tcon);
848 	kfree(scon);
849 	return length;
850 }
851 
852 static ssize_t sel_write_relabel(struct file *file, char *buf, size_t size)
853 {
854 	char *scon = NULL, *tcon = NULL;
855 	u32 ssid, tsid, newsid;
856 	u16 tclass;
857 	ssize_t length;
858 	char *newcon = NULL;
859 	u32 len;
860 
861 	length = task_has_security(current, SECURITY__COMPUTE_RELABEL);
862 	if (length)
863 		goto out;
864 
865 	length = -ENOMEM;
866 	scon = kzalloc(size + 1, GFP_KERNEL);
867 	if (!scon)
868 		goto out;
869 
870 	length = -ENOMEM;
871 	tcon = kzalloc(size + 1, GFP_KERNEL);
872 	if (!tcon)
873 		goto out;
874 
875 	length = -EINVAL;
876 	if (sscanf(buf, "%s %s %hu", scon, tcon, &tclass) != 3)
877 		goto out;
878 
879 	length = security_context_to_sid(scon, strlen(scon) + 1, &ssid);
880 	if (length)
881 		goto out;
882 
883 	length = security_context_to_sid(tcon, strlen(tcon) + 1, &tsid);
884 	if (length)
885 		goto out;
886 
887 	length = security_change_sid(ssid, tsid, tclass, &newsid);
888 	if (length)
889 		goto out;
890 
891 	length = security_sid_to_context(newsid, &newcon, &len);
892 	if (length)
893 		goto out;
894 
895 	length = -ERANGE;
896 	if (len > SIMPLE_TRANSACTION_LIMIT)
897 		goto out;
898 
899 	memcpy(buf, newcon, len);
900 	length = len;
901 out:
902 	kfree(newcon);
903 	kfree(tcon);
904 	kfree(scon);
905 	return length;
906 }
907 
908 static ssize_t sel_write_user(struct file *file, char *buf, size_t size)
909 {
910 	char *con = NULL, *user = NULL, *ptr;
911 	u32 sid, *sids = NULL;
912 	ssize_t length;
913 	char *newcon;
914 	int i, rc;
915 	u32 len, nsids;
916 
917 	length = task_has_security(current, SECURITY__COMPUTE_USER);
918 	if (length)
919 		goto out;
920 
921 	length = -ENOMEM;
922 	con = kzalloc(size + 1, GFP_KERNEL);
923 	if (!con)
924 		goto out;
925 
926 	length = -ENOMEM;
927 	user = kzalloc(size + 1, GFP_KERNEL);
928 	if (!user)
929 		goto out;
930 
931 	length = -EINVAL;
932 	if (sscanf(buf, "%s %s", con, user) != 2)
933 		goto out;
934 
935 	length = security_context_to_sid(con, strlen(con) + 1, &sid);
936 	if (length)
937 		goto out;
938 
939 	length = security_get_user_sids(sid, user, &sids, &nsids);
940 	if (length)
941 		goto out;
942 
943 	length = sprintf(buf, "%u", nsids) + 1;
944 	ptr = buf + length;
945 	for (i = 0; i < nsids; i++) {
946 		rc = security_sid_to_context(sids[i], &newcon, &len);
947 		if (rc) {
948 			length = rc;
949 			goto out;
950 		}
951 		if ((length + len) >= SIMPLE_TRANSACTION_LIMIT) {
952 			kfree(newcon);
953 			length = -ERANGE;
954 			goto out;
955 		}
956 		memcpy(ptr, newcon, len);
957 		kfree(newcon);
958 		ptr += len;
959 		length += len;
960 	}
961 out:
962 	kfree(sids);
963 	kfree(user);
964 	kfree(con);
965 	return length;
966 }
967 
968 static ssize_t sel_write_member(struct file *file, char *buf, size_t size)
969 {
970 	char *scon = NULL, *tcon = NULL;
971 	u32 ssid, tsid, newsid;
972 	u16 tclass;
973 	ssize_t length;
974 	char *newcon = NULL;
975 	u32 len;
976 
977 	length = task_has_security(current, SECURITY__COMPUTE_MEMBER);
978 	if (length)
979 		goto out;
980 
981 	length = -ENOMEM;
982 	scon = kzalloc(size + 1, GFP_KERNEL);
983 	if (!scon)
984 		goto out;
985 
986 	length = -ENOMEM;
987 	tcon = kzalloc(size + 1, GFP_KERNEL);
988 	if (!tcon)
989 		goto out;
990 
991 	length = -EINVAL;
992 	if (sscanf(buf, "%s %s %hu", scon, tcon, &tclass) != 3)
993 		goto out;
994 
995 	length = security_context_to_sid(scon, strlen(scon) + 1, &ssid);
996 	if (length)
997 		goto out;
998 
999 	length = security_context_to_sid(tcon, strlen(tcon) + 1, &tsid);
1000 	if (length)
1001 		goto out;
1002 
1003 	length = security_member_sid(ssid, tsid, tclass, &newsid);
1004 	if (length)
1005 		goto out;
1006 
1007 	length = security_sid_to_context(newsid, &newcon, &len);
1008 	if (length)
1009 		goto out;
1010 
1011 	length = -ERANGE;
1012 	if (len > SIMPLE_TRANSACTION_LIMIT) {
1013 		printk(KERN_ERR "SELinux: %s:  context size (%u) exceeds "
1014 			"payload max\n", __func__, len);
1015 		goto out;
1016 	}
1017 
1018 	memcpy(buf, newcon, len);
1019 	length = len;
1020 out:
1021 	kfree(newcon);
1022 	kfree(tcon);
1023 	kfree(scon);
1024 	return length;
1025 }
1026 
1027 static struct inode *sel_make_inode(struct super_block *sb, int mode)
1028 {
1029 	struct inode *ret = new_inode(sb);
1030 
1031 	if (ret) {
1032 		ret->i_mode = mode;
1033 		ret->i_atime = ret->i_mtime = ret->i_ctime = CURRENT_TIME;
1034 	}
1035 	return ret;
1036 }
1037 
1038 static ssize_t sel_read_bool(struct file *filep, char __user *buf,
1039 			     size_t count, loff_t *ppos)
1040 {
1041 	char *page = NULL;
1042 	ssize_t length;
1043 	ssize_t ret;
1044 	int cur_enforcing;
1045 	unsigned index = file_inode(filep)->i_ino & SEL_INO_MASK;
1046 	const char *name = filep->f_path.dentry->d_name.name;
1047 
1048 	mutex_lock(&sel_mutex);
1049 
1050 	ret = -EINVAL;
1051 	if (index >= bool_num || strcmp(name, bool_pending_names[index]))
1052 		goto out;
1053 
1054 	ret = -ENOMEM;
1055 	page = (char *)get_zeroed_page(GFP_KERNEL);
1056 	if (!page)
1057 		goto out;
1058 
1059 	cur_enforcing = security_get_bool_value(index);
1060 	if (cur_enforcing < 0) {
1061 		ret = cur_enforcing;
1062 		goto out;
1063 	}
1064 	length = scnprintf(page, PAGE_SIZE, "%d %d", cur_enforcing,
1065 			  bool_pending_values[index]);
1066 	ret = simple_read_from_buffer(buf, count, ppos, page, length);
1067 out:
1068 	mutex_unlock(&sel_mutex);
1069 	free_page((unsigned long)page);
1070 	return ret;
1071 }
1072 
1073 static ssize_t sel_write_bool(struct file *filep, const char __user *buf,
1074 			      size_t count, loff_t *ppos)
1075 {
1076 	char *page = NULL;
1077 	ssize_t length;
1078 	int new_value;
1079 	unsigned index = file_inode(filep)->i_ino & SEL_INO_MASK;
1080 	const char *name = filep->f_path.dentry->d_name.name;
1081 
1082 	mutex_lock(&sel_mutex);
1083 
1084 	length = task_has_security(current, SECURITY__SETBOOL);
1085 	if (length)
1086 		goto out;
1087 
1088 	length = -EINVAL;
1089 	if (index >= bool_num || strcmp(name, bool_pending_names[index]))
1090 		goto out;
1091 
1092 	length = -ENOMEM;
1093 	if (count >= PAGE_SIZE)
1094 		goto out;
1095 
1096 	/* No partial writes. */
1097 	length = -EINVAL;
1098 	if (*ppos != 0)
1099 		goto out;
1100 
1101 	length = -ENOMEM;
1102 	page = (char *)get_zeroed_page(GFP_KERNEL);
1103 	if (!page)
1104 		goto out;
1105 
1106 	length = -EFAULT;
1107 	if (copy_from_user(page, buf, count))
1108 		goto out;
1109 
1110 	length = -EINVAL;
1111 	if (sscanf(page, "%d", &new_value) != 1)
1112 		goto out;
1113 
1114 	if (new_value)
1115 		new_value = 1;
1116 
1117 	bool_pending_values[index] = new_value;
1118 	length = count;
1119 
1120 out:
1121 	mutex_unlock(&sel_mutex);
1122 	free_page((unsigned long) page);
1123 	return length;
1124 }
1125 
1126 static const struct file_operations sel_bool_ops = {
1127 	.read		= sel_read_bool,
1128 	.write		= sel_write_bool,
1129 	.llseek		= generic_file_llseek,
1130 };
1131 
1132 static ssize_t sel_commit_bools_write(struct file *filep,
1133 				      const char __user *buf,
1134 				      size_t count, loff_t *ppos)
1135 {
1136 	char *page = NULL;
1137 	ssize_t length;
1138 	int new_value;
1139 
1140 	mutex_lock(&sel_mutex);
1141 
1142 	length = task_has_security(current, SECURITY__SETBOOL);
1143 	if (length)
1144 		goto out;
1145 
1146 	length = -ENOMEM;
1147 	if (count >= PAGE_SIZE)
1148 		goto out;
1149 
1150 	/* No partial writes. */
1151 	length = -EINVAL;
1152 	if (*ppos != 0)
1153 		goto out;
1154 
1155 	length = -ENOMEM;
1156 	page = (char *)get_zeroed_page(GFP_KERNEL);
1157 	if (!page)
1158 		goto out;
1159 
1160 	length = -EFAULT;
1161 	if (copy_from_user(page, buf, count))
1162 		goto out;
1163 
1164 	length = -EINVAL;
1165 	if (sscanf(page, "%d", &new_value) != 1)
1166 		goto out;
1167 
1168 	length = 0;
1169 	if (new_value && bool_pending_values)
1170 		length = security_set_bools(bool_num, bool_pending_values);
1171 
1172 	if (!length)
1173 		length = count;
1174 
1175 out:
1176 	mutex_unlock(&sel_mutex);
1177 	free_page((unsigned long) page);
1178 	return length;
1179 }
1180 
1181 static const struct file_operations sel_commit_bools_ops = {
1182 	.write		= sel_commit_bools_write,
1183 	.llseek		= generic_file_llseek,
1184 };
1185 
1186 static void sel_remove_entries(struct dentry *de)
1187 {
1188 	struct list_head *node;
1189 
1190 	spin_lock(&de->d_lock);
1191 	node = de->d_subdirs.next;
1192 	while (node != &de->d_subdirs) {
1193 		struct dentry *d = list_entry(node, struct dentry, d_u.d_child);
1194 
1195 		spin_lock_nested(&d->d_lock, DENTRY_D_LOCK_NESTED);
1196 		list_del_init(node);
1197 
1198 		if (d->d_inode) {
1199 			dget_dlock(d);
1200 			spin_unlock(&de->d_lock);
1201 			spin_unlock(&d->d_lock);
1202 			d_delete(d);
1203 			simple_unlink(de->d_inode, d);
1204 			dput(d);
1205 			spin_lock(&de->d_lock);
1206 		} else
1207 			spin_unlock(&d->d_lock);
1208 		node = de->d_subdirs.next;
1209 	}
1210 
1211 	spin_unlock(&de->d_lock);
1212 }
1213 
1214 #define BOOL_DIR_NAME "booleans"
1215 
1216 static int sel_make_bools(void)
1217 {
1218 	int i, ret;
1219 	ssize_t len;
1220 	struct dentry *dentry = NULL;
1221 	struct dentry *dir = bool_dir;
1222 	struct inode *inode = NULL;
1223 	struct inode_security_struct *isec;
1224 	char **names = NULL, *page;
1225 	int num;
1226 	int *values = NULL;
1227 	u32 sid;
1228 
1229 	/* remove any existing files */
1230 	for (i = 0; i < bool_num; i++)
1231 		kfree(bool_pending_names[i]);
1232 	kfree(bool_pending_names);
1233 	kfree(bool_pending_values);
1234 	bool_num = 0;
1235 	bool_pending_names = NULL;
1236 	bool_pending_values = NULL;
1237 
1238 	sel_remove_entries(dir);
1239 
1240 	ret = -ENOMEM;
1241 	page = (char *)get_zeroed_page(GFP_KERNEL);
1242 	if (!page)
1243 		goto out;
1244 
1245 	ret = security_get_bools(&num, &names, &values);
1246 	if (ret)
1247 		goto out;
1248 
1249 	for (i = 0; i < num; i++) {
1250 		ret = -ENOMEM;
1251 		dentry = d_alloc_name(dir, names[i]);
1252 		if (!dentry)
1253 			goto out;
1254 
1255 		ret = -ENOMEM;
1256 		inode = sel_make_inode(dir->d_sb, S_IFREG | S_IRUGO | S_IWUSR);
1257 		if (!inode)
1258 			goto out;
1259 
1260 		ret = -ENAMETOOLONG;
1261 		len = snprintf(page, PAGE_SIZE, "/%s/%s", BOOL_DIR_NAME, names[i]);
1262 		if (len >= PAGE_SIZE)
1263 			goto out;
1264 
1265 		isec = (struct inode_security_struct *)inode->i_security;
1266 		ret = security_genfs_sid("selinuxfs", page, SECCLASS_FILE, &sid);
1267 		if (ret)
1268 			goto out;
1269 
1270 		isec->sid = sid;
1271 		isec->initialized = 1;
1272 		inode->i_fop = &sel_bool_ops;
1273 		inode->i_ino = i|SEL_BOOL_INO_OFFSET;
1274 		d_add(dentry, inode);
1275 	}
1276 	bool_num = num;
1277 	bool_pending_names = names;
1278 	bool_pending_values = values;
1279 
1280 	free_page((unsigned long)page);
1281 	return 0;
1282 out:
1283 	free_page((unsigned long)page);
1284 
1285 	if (names) {
1286 		for (i = 0; i < num; i++)
1287 			kfree(names[i]);
1288 		kfree(names);
1289 	}
1290 	kfree(values);
1291 	sel_remove_entries(dir);
1292 
1293 	return ret;
1294 }
1295 
1296 #define NULL_FILE_NAME "null"
1297 
1298 struct path selinux_null;
1299 
1300 static ssize_t sel_read_avc_cache_threshold(struct file *filp, char __user *buf,
1301 					    size_t count, loff_t *ppos)
1302 {
1303 	char tmpbuf[TMPBUFLEN];
1304 	ssize_t length;
1305 
1306 	length = scnprintf(tmpbuf, TMPBUFLEN, "%u", avc_cache_threshold);
1307 	return simple_read_from_buffer(buf, count, ppos, tmpbuf, length);
1308 }
1309 
1310 static ssize_t sel_write_avc_cache_threshold(struct file *file,
1311 					     const char __user *buf,
1312 					     size_t count, loff_t *ppos)
1313 
1314 {
1315 	char *page = NULL;
1316 	ssize_t ret;
1317 	int new_value;
1318 
1319 	ret = task_has_security(current, SECURITY__SETSECPARAM);
1320 	if (ret)
1321 		goto out;
1322 
1323 	ret = -ENOMEM;
1324 	if (count >= PAGE_SIZE)
1325 		goto out;
1326 
1327 	/* No partial writes. */
1328 	ret = -EINVAL;
1329 	if (*ppos != 0)
1330 		goto out;
1331 
1332 	ret = -ENOMEM;
1333 	page = (char *)get_zeroed_page(GFP_KERNEL);
1334 	if (!page)
1335 		goto out;
1336 
1337 	ret = -EFAULT;
1338 	if (copy_from_user(page, buf, count))
1339 		goto out;
1340 
1341 	ret = -EINVAL;
1342 	if (sscanf(page, "%u", &new_value) != 1)
1343 		goto out;
1344 
1345 	avc_cache_threshold = new_value;
1346 
1347 	ret = count;
1348 out:
1349 	free_page((unsigned long)page);
1350 	return ret;
1351 }
1352 
1353 static ssize_t sel_read_avc_hash_stats(struct file *filp, char __user *buf,
1354 				       size_t count, loff_t *ppos)
1355 {
1356 	char *page;
1357 	ssize_t length;
1358 
1359 	page = (char *)__get_free_page(GFP_KERNEL);
1360 	if (!page)
1361 		return -ENOMEM;
1362 
1363 	length = avc_get_hash_stats(page);
1364 	if (length >= 0)
1365 		length = simple_read_from_buffer(buf, count, ppos, page, length);
1366 	free_page((unsigned long)page);
1367 
1368 	return length;
1369 }
1370 
1371 static const struct file_operations sel_avc_cache_threshold_ops = {
1372 	.read		= sel_read_avc_cache_threshold,
1373 	.write		= sel_write_avc_cache_threshold,
1374 	.llseek		= generic_file_llseek,
1375 };
1376 
1377 static const struct file_operations sel_avc_hash_stats_ops = {
1378 	.read		= sel_read_avc_hash_stats,
1379 	.llseek		= generic_file_llseek,
1380 };
1381 
1382 #ifdef CONFIG_SECURITY_SELINUX_AVC_STATS
1383 static struct avc_cache_stats *sel_avc_get_stat_idx(loff_t *idx)
1384 {
1385 	int cpu;
1386 
1387 	for (cpu = *idx; cpu < nr_cpu_ids; ++cpu) {
1388 		if (!cpu_possible(cpu))
1389 			continue;
1390 		*idx = cpu + 1;
1391 		return &per_cpu(avc_cache_stats, cpu);
1392 	}
1393 	return NULL;
1394 }
1395 
1396 static void *sel_avc_stats_seq_start(struct seq_file *seq, loff_t *pos)
1397 {
1398 	loff_t n = *pos - 1;
1399 
1400 	if (*pos == 0)
1401 		return SEQ_START_TOKEN;
1402 
1403 	return sel_avc_get_stat_idx(&n);
1404 }
1405 
1406 static void *sel_avc_stats_seq_next(struct seq_file *seq, void *v, loff_t *pos)
1407 {
1408 	return sel_avc_get_stat_idx(pos);
1409 }
1410 
1411 static int sel_avc_stats_seq_show(struct seq_file *seq, void *v)
1412 {
1413 	struct avc_cache_stats *st = v;
1414 
1415 	if (v == SEQ_START_TOKEN)
1416 		seq_printf(seq, "lookups hits misses allocations reclaims "
1417 			   "frees\n");
1418 	else {
1419 		unsigned int lookups = st->lookups;
1420 		unsigned int misses = st->misses;
1421 		unsigned int hits = lookups - misses;
1422 		seq_printf(seq, "%u %u %u %u %u %u\n", lookups,
1423 			   hits, misses, st->allocations,
1424 			   st->reclaims, st->frees);
1425 	}
1426 	return 0;
1427 }
1428 
1429 static void sel_avc_stats_seq_stop(struct seq_file *seq, void *v)
1430 { }
1431 
1432 static const struct seq_operations sel_avc_cache_stats_seq_ops = {
1433 	.start		= sel_avc_stats_seq_start,
1434 	.next		= sel_avc_stats_seq_next,
1435 	.show		= sel_avc_stats_seq_show,
1436 	.stop		= sel_avc_stats_seq_stop,
1437 };
1438 
1439 static int sel_open_avc_cache_stats(struct inode *inode, struct file *file)
1440 {
1441 	return seq_open(file, &sel_avc_cache_stats_seq_ops);
1442 }
1443 
1444 static const struct file_operations sel_avc_cache_stats_ops = {
1445 	.open		= sel_open_avc_cache_stats,
1446 	.read		= seq_read,
1447 	.llseek		= seq_lseek,
1448 	.release	= seq_release,
1449 };
1450 #endif
1451 
1452 static int sel_make_avc_files(struct dentry *dir)
1453 {
1454 	int i;
1455 	static struct tree_descr files[] = {
1456 		{ "cache_threshold",
1457 		  &sel_avc_cache_threshold_ops, S_IRUGO|S_IWUSR },
1458 		{ "hash_stats", &sel_avc_hash_stats_ops, S_IRUGO },
1459 #ifdef CONFIG_SECURITY_SELINUX_AVC_STATS
1460 		{ "cache_stats", &sel_avc_cache_stats_ops, S_IRUGO },
1461 #endif
1462 	};
1463 
1464 	for (i = 0; i < ARRAY_SIZE(files); i++) {
1465 		struct inode *inode;
1466 		struct dentry *dentry;
1467 
1468 		dentry = d_alloc_name(dir, files[i].name);
1469 		if (!dentry)
1470 			return -ENOMEM;
1471 
1472 		inode = sel_make_inode(dir->d_sb, S_IFREG|files[i].mode);
1473 		if (!inode)
1474 			return -ENOMEM;
1475 
1476 		inode->i_fop = files[i].ops;
1477 		inode->i_ino = ++sel_last_ino;
1478 		d_add(dentry, inode);
1479 	}
1480 
1481 	return 0;
1482 }
1483 
1484 static ssize_t sel_read_initcon(struct file *file, char __user *buf,
1485 				size_t count, loff_t *ppos)
1486 {
1487 	char *con;
1488 	u32 sid, len;
1489 	ssize_t ret;
1490 
1491 	sid = file_inode(file)->i_ino&SEL_INO_MASK;
1492 	ret = security_sid_to_context(sid, &con, &len);
1493 	if (ret)
1494 		return ret;
1495 
1496 	ret = simple_read_from_buffer(buf, count, ppos, con, len);
1497 	kfree(con);
1498 	return ret;
1499 }
1500 
1501 static const struct file_operations sel_initcon_ops = {
1502 	.read		= sel_read_initcon,
1503 	.llseek		= generic_file_llseek,
1504 };
1505 
1506 static int sel_make_initcon_files(struct dentry *dir)
1507 {
1508 	int i;
1509 
1510 	for (i = 1; i <= SECINITSID_NUM; i++) {
1511 		struct inode *inode;
1512 		struct dentry *dentry;
1513 		dentry = d_alloc_name(dir, security_get_initial_sid_context(i));
1514 		if (!dentry)
1515 			return -ENOMEM;
1516 
1517 		inode = sel_make_inode(dir->d_sb, S_IFREG|S_IRUGO);
1518 		if (!inode)
1519 			return -ENOMEM;
1520 
1521 		inode->i_fop = &sel_initcon_ops;
1522 		inode->i_ino = i|SEL_INITCON_INO_OFFSET;
1523 		d_add(dentry, inode);
1524 	}
1525 
1526 	return 0;
1527 }
1528 
1529 static inline unsigned long sel_class_to_ino(u16 class)
1530 {
1531 	return (class * (SEL_VEC_MAX + 1)) | SEL_CLASS_INO_OFFSET;
1532 }
1533 
1534 static inline u16 sel_ino_to_class(unsigned long ino)
1535 {
1536 	return (ino & SEL_INO_MASK) / (SEL_VEC_MAX + 1);
1537 }
1538 
1539 static inline unsigned long sel_perm_to_ino(u16 class, u32 perm)
1540 {
1541 	return (class * (SEL_VEC_MAX + 1) + perm) | SEL_CLASS_INO_OFFSET;
1542 }
1543 
1544 static inline u32 sel_ino_to_perm(unsigned long ino)
1545 {
1546 	return (ino & SEL_INO_MASK) % (SEL_VEC_MAX + 1);
1547 }
1548 
1549 static ssize_t sel_read_class(struct file *file, char __user *buf,
1550 				size_t count, loff_t *ppos)
1551 {
1552 	unsigned long ino = file_inode(file)->i_ino;
1553 	char res[TMPBUFLEN];
1554 	ssize_t len = snprintf(res, sizeof(res), "%d", sel_ino_to_class(ino));
1555 	return simple_read_from_buffer(buf, count, ppos, res, len);
1556 }
1557 
1558 static const struct file_operations sel_class_ops = {
1559 	.read		= sel_read_class,
1560 	.llseek		= generic_file_llseek,
1561 };
1562 
1563 static ssize_t sel_read_perm(struct file *file, char __user *buf,
1564 				size_t count, loff_t *ppos)
1565 {
1566 	unsigned long ino = file_inode(file)->i_ino;
1567 	char res[TMPBUFLEN];
1568 	ssize_t len = snprintf(res, sizeof(res), "%d", sel_ino_to_perm(ino));
1569 	return simple_read_from_buffer(buf, count, ppos, res, len);
1570 }
1571 
1572 static const struct file_operations sel_perm_ops = {
1573 	.read		= sel_read_perm,
1574 	.llseek		= generic_file_llseek,
1575 };
1576 
1577 static ssize_t sel_read_policycap(struct file *file, char __user *buf,
1578 				  size_t count, loff_t *ppos)
1579 {
1580 	int value;
1581 	char tmpbuf[TMPBUFLEN];
1582 	ssize_t length;
1583 	unsigned long i_ino = file_inode(file)->i_ino;
1584 
1585 	value = security_policycap_supported(i_ino & SEL_INO_MASK);
1586 	length = scnprintf(tmpbuf, TMPBUFLEN, "%d", value);
1587 
1588 	return simple_read_from_buffer(buf, count, ppos, tmpbuf, length);
1589 }
1590 
1591 static const struct file_operations sel_policycap_ops = {
1592 	.read		= sel_read_policycap,
1593 	.llseek		= generic_file_llseek,
1594 };
1595 
1596 static int sel_make_perm_files(char *objclass, int classvalue,
1597 				struct dentry *dir)
1598 {
1599 	int i, rc, nperms;
1600 	char **perms;
1601 
1602 	rc = security_get_permissions(objclass, &perms, &nperms);
1603 	if (rc)
1604 		return rc;
1605 
1606 	for (i = 0; i < nperms; i++) {
1607 		struct inode *inode;
1608 		struct dentry *dentry;
1609 
1610 		rc = -ENOMEM;
1611 		dentry = d_alloc_name(dir, perms[i]);
1612 		if (!dentry)
1613 			goto out;
1614 
1615 		rc = -ENOMEM;
1616 		inode = sel_make_inode(dir->d_sb, S_IFREG|S_IRUGO);
1617 		if (!inode)
1618 			goto out;
1619 
1620 		inode->i_fop = &sel_perm_ops;
1621 		/* i+1 since perm values are 1-indexed */
1622 		inode->i_ino = sel_perm_to_ino(classvalue, i + 1);
1623 		d_add(dentry, inode);
1624 	}
1625 	rc = 0;
1626 out:
1627 	for (i = 0; i < nperms; i++)
1628 		kfree(perms[i]);
1629 	kfree(perms);
1630 	return rc;
1631 }
1632 
1633 static int sel_make_class_dir_entries(char *classname, int index,
1634 					struct dentry *dir)
1635 {
1636 	struct dentry *dentry = NULL;
1637 	struct inode *inode = NULL;
1638 	int rc;
1639 
1640 	dentry = d_alloc_name(dir, "index");
1641 	if (!dentry)
1642 		return -ENOMEM;
1643 
1644 	inode = sel_make_inode(dir->d_sb, S_IFREG|S_IRUGO);
1645 	if (!inode)
1646 		return -ENOMEM;
1647 
1648 	inode->i_fop = &sel_class_ops;
1649 	inode->i_ino = sel_class_to_ino(index);
1650 	d_add(dentry, inode);
1651 
1652 	dentry = sel_make_dir(dir, "perms", &last_class_ino);
1653 	if (IS_ERR(dentry))
1654 		return PTR_ERR(dentry);
1655 
1656 	rc = sel_make_perm_files(classname, index, dentry);
1657 
1658 	return rc;
1659 }
1660 
1661 static void sel_remove_classes(void)
1662 {
1663 	struct list_head *class_node;
1664 
1665 	list_for_each(class_node, &class_dir->d_subdirs) {
1666 		struct dentry *class_subdir = list_entry(class_node,
1667 					struct dentry, d_u.d_child);
1668 		struct list_head *class_subdir_node;
1669 
1670 		list_for_each(class_subdir_node, &class_subdir->d_subdirs) {
1671 			struct dentry *d = list_entry(class_subdir_node,
1672 						struct dentry, d_u.d_child);
1673 
1674 			if (d->d_inode)
1675 				if (d->d_inode->i_mode & S_IFDIR)
1676 					sel_remove_entries(d);
1677 		}
1678 
1679 		sel_remove_entries(class_subdir);
1680 	}
1681 
1682 	sel_remove_entries(class_dir);
1683 }
1684 
1685 static int sel_make_classes(void)
1686 {
1687 	int rc, nclasses, i;
1688 	char **classes;
1689 
1690 	/* delete any existing entries */
1691 	sel_remove_classes();
1692 
1693 	rc = security_get_classes(&classes, &nclasses);
1694 	if (rc)
1695 		return rc;
1696 
1697 	/* +2 since classes are 1-indexed */
1698 	last_class_ino = sel_class_to_ino(nclasses + 2);
1699 
1700 	for (i = 0; i < nclasses; i++) {
1701 		struct dentry *class_name_dir;
1702 
1703 		class_name_dir = sel_make_dir(class_dir, classes[i],
1704 				&last_class_ino);
1705 		if (IS_ERR(class_name_dir)) {
1706 			rc = PTR_ERR(class_name_dir);
1707 			goto out;
1708 		}
1709 
1710 		/* i+1 since class values are 1-indexed */
1711 		rc = sel_make_class_dir_entries(classes[i], i + 1,
1712 				class_name_dir);
1713 		if (rc)
1714 			goto out;
1715 	}
1716 	rc = 0;
1717 out:
1718 	for (i = 0; i < nclasses; i++)
1719 		kfree(classes[i]);
1720 	kfree(classes);
1721 	return rc;
1722 }
1723 
1724 static int sel_make_policycap(void)
1725 {
1726 	unsigned int iter;
1727 	struct dentry *dentry = NULL;
1728 	struct inode *inode = NULL;
1729 
1730 	sel_remove_entries(policycap_dir);
1731 
1732 	for (iter = 0; iter <= POLICYDB_CAPABILITY_MAX; iter++) {
1733 		if (iter < ARRAY_SIZE(policycap_names))
1734 			dentry = d_alloc_name(policycap_dir,
1735 					      policycap_names[iter]);
1736 		else
1737 			dentry = d_alloc_name(policycap_dir, "unknown");
1738 
1739 		if (dentry == NULL)
1740 			return -ENOMEM;
1741 
1742 		inode = sel_make_inode(policycap_dir->d_sb, S_IFREG | S_IRUGO);
1743 		if (inode == NULL)
1744 			return -ENOMEM;
1745 
1746 		inode->i_fop = &sel_policycap_ops;
1747 		inode->i_ino = iter | SEL_POLICYCAP_INO_OFFSET;
1748 		d_add(dentry, inode);
1749 	}
1750 
1751 	return 0;
1752 }
1753 
1754 static struct dentry *sel_make_dir(struct dentry *dir, const char *name,
1755 			unsigned long *ino)
1756 {
1757 	struct dentry *dentry = d_alloc_name(dir, name);
1758 	struct inode *inode;
1759 
1760 	if (!dentry)
1761 		return ERR_PTR(-ENOMEM);
1762 
1763 	inode = sel_make_inode(dir->d_sb, S_IFDIR | S_IRUGO | S_IXUGO);
1764 	if (!inode) {
1765 		dput(dentry);
1766 		return ERR_PTR(-ENOMEM);
1767 	}
1768 
1769 	inode->i_op = &simple_dir_inode_operations;
1770 	inode->i_fop = &simple_dir_operations;
1771 	inode->i_ino = ++(*ino);
1772 	/* directory inodes start off with i_nlink == 2 (for "." entry) */
1773 	inc_nlink(inode);
1774 	d_add(dentry, inode);
1775 	/* bump link count on parent directory, too */
1776 	inc_nlink(dir->d_inode);
1777 
1778 	return dentry;
1779 }
1780 
1781 static int sel_fill_super(struct super_block *sb, void *data, int silent)
1782 {
1783 	int ret;
1784 	struct dentry *dentry;
1785 	struct inode *inode;
1786 	struct inode_security_struct *isec;
1787 
1788 	static struct tree_descr selinux_files[] = {
1789 		[SEL_LOAD] = {"load", &sel_load_ops, S_IRUSR|S_IWUSR},
1790 		[SEL_ENFORCE] = {"enforce", &sel_enforce_ops, S_IRUGO|S_IWUSR},
1791 		[SEL_CONTEXT] = {"context", &transaction_ops, S_IRUGO|S_IWUGO},
1792 		[SEL_ACCESS] = {"access", &transaction_ops, S_IRUGO|S_IWUGO},
1793 		[SEL_CREATE] = {"create", &transaction_ops, S_IRUGO|S_IWUGO},
1794 		[SEL_RELABEL] = {"relabel", &transaction_ops, S_IRUGO|S_IWUGO},
1795 		[SEL_USER] = {"user", &transaction_ops, S_IRUGO|S_IWUGO},
1796 		[SEL_POLICYVERS] = {"policyvers", &sel_policyvers_ops, S_IRUGO},
1797 		[SEL_COMMIT_BOOLS] = {"commit_pending_bools", &sel_commit_bools_ops, S_IWUSR},
1798 		[SEL_MLS] = {"mls", &sel_mls_ops, S_IRUGO},
1799 		[SEL_DISABLE] = {"disable", &sel_disable_ops, S_IWUSR},
1800 		[SEL_MEMBER] = {"member", &transaction_ops, S_IRUGO|S_IWUGO},
1801 		[SEL_CHECKREQPROT] = {"checkreqprot", &sel_checkreqprot_ops, S_IRUGO|S_IWUSR},
1802 		[SEL_REJECT_UNKNOWN] = {"reject_unknown", &sel_handle_unknown_ops, S_IRUGO},
1803 		[SEL_DENY_UNKNOWN] = {"deny_unknown", &sel_handle_unknown_ops, S_IRUGO},
1804 		[SEL_STATUS] = {"status", &sel_handle_status_ops, S_IRUGO},
1805 		[SEL_POLICY] = {"policy", &sel_policy_ops, S_IRUGO},
1806 		/* last one */ {""}
1807 	};
1808 	ret = simple_fill_super(sb, SELINUX_MAGIC, selinux_files);
1809 	if (ret)
1810 		goto err;
1811 
1812 	bool_dir = sel_make_dir(sb->s_root, BOOL_DIR_NAME, &sel_last_ino);
1813 	if (IS_ERR(bool_dir)) {
1814 		ret = PTR_ERR(bool_dir);
1815 		bool_dir = NULL;
1816 		goto err;
1817 	}
1818 
1819 	ret = -ENOMEM;
1820 	dentry = d_alloc_name(sb->s_root, NULL_FILE_NAME);
1821 	if (!dentry)
1822 		goto err;
1823 
1824 	ret = -ENOMEM;
1825 	inode = sel_make_inode(sb, S_IFCHR | S_IRUGO | S_IWUGO);
1826 	if (!inode)
1827 		goto err;
1828 
1829 	inode->i_ino = ++sel_last_ino;
1830 	isec = (struct inode_security_struct *)inode->i_security;
1831 	isec->sid = SECINITSID_DEVNULL;
1832 	isec->sclass = SECCLASS_CHR_FILE;
1833 	isec->initialized = 1;
1834 
1835 	init_special_inode(inode, S_IFCHR | S_IRUGO | S_IWUGO, MKDEV(MEM_MAJOR, 3));
1836 	d_add(dentry, inode);
1837 	selinux_null.dentry = dentry;
1838 
1839 	dentry = sel_make_dir(sb->s_root, "avc", &sel_last_ino);
1840 	if (IS_ERR(dentry)) {
1841 		ret = PTR_ERR(dentry);
1842 		goto err;
1843 	}
1844 
1845 	ret = sel_make_avc_files(dentry);
1846 	if (ret)
1847 		goto err;
1848 
1849 	dentry = sel_make_dir(sb->s_root, "initial_contexts", &sel_last_ino);
1850 	if (IS_ERR(dentry)) {
1851 		ret = PTR_ERR(dentry);
1852 		goto err;
1853 	}
1854 
1855 	ret = sel_make_initcon_files(dentry);
1856 	if (ret)
1857 		goto err;
1858 
1859 	class_dir = sel_make_dir(sb->s_root, "class", &sel_last_ino);
1860 	if (IS_ERR(class_dir)) {
1861 		ret = PTR_ERR(class_dir);
1862 		class_dir = NULL;
1863 		goto err;
1864 	}
1865 
1866 	policycap_dir = sel_make_dir(sb->s_root, "policy_capabilities", &sel_last_ino);
1867 	if (IS_ERR(policycap_dir)) {
1868 		ret = PTR_ERR(policycap_dir);
1869 		policycap_dir = NULL;
1870 		goto err;
1871 	}
1872 	return 0;
1873 err:
1874 	printk(KERN_ERR "SELinux: %s:  failed while creating inodes\n",
1875 		__func__);
1876 	return ret;
1877 }
1878 
1879 static struct dentry *sel_mount(struct file_system_type *fs_type,
1880 		      int flags, const char *dev_name, void *data)
1881 {
1882 	return mount_single(fs_type, flags, data, sel_fill_super);
1883 }
1884 
1885 static struct file_system_type sel_fs_type = {
1886 	.name		= "selinuxfs",
1887 	.mount		= sel_mount,
1888 	.kill_sb	= kill_litter_super,
1889 };
1890 
1891 struct vfsmount *selinuxfs_mount;
1892 static struct kobject *selinuxfs_kobj;
1893 
1894 static int __init init_sel_fs(void)
1895 {
1896 	int err;
1897 
1898 	if (!selinux_enabled)
1899 		return 0;
1900 
1901 	selinuxfs_kobj = kobject_create_and_add("selinux", fs_kobj);
1902 	if (!selinuxfs_kobj)
1903 		return -ENOMEM;
1904 
1905 	err = register_filesystem(&sel_fs_type);
1906 	if (err) {
1907 		kobject_put(selinuxfs_kobj);
1908 		return err;
1909 	}
1910 
1911 	selinux_null.mnt = selinuxfs_mount = kern_mount(&sel_fs_type);
1912 	if (IS_ERR(selinuxfs_mount)) {
1913 		printk(KERN_ERR "selinuxfs:  could not mount!\n");
1914 		err = PTR_ERR(selinuxfs_mount);
1915 		selinuxfs_mount = NULL;
1916 	}
1917 
1918 	return err;
1919 }
1920 
1921 __initcall(init_sel_fs);
1922 
1923 #ifdef CONFIG_SECURITY_SELINUX_DISABLE
1924 void exit_sel_fs(void)
1925 {
1926 	kobject_put(selinuxfs_kobj);
1927 	kern_unmount(selinuxfs_mount);
1928 	unregister_filesystem(&sel_fs_type);
1929 }
1930 #endif
1931