VFS : mount lock scalability for internal mounts
[linux-2.6.git] / security / selinux / selinuxfs.c
1 /* Updated: Karl MacMillan <kmacmillan@tresys.com>
2  *
3  *      Added conditional policy language extensions
4  *
5  *  Updated: Hewlett-Packard <paul.moore@hp.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 extern void selnl_notify_setenforce(int val);
79
80 /* Check whether a task is allowed to use a security operation. */
81 static int task_has_security(struct task_struct *tsk,
82                              u32 perms)
83 {
84         const struct task_security_struct *tsec;
85         u32 sid = 0;
86
87         rcu_read_lock();
88         tsec = __task_cred(tsk)->security;
89         if (tsec)
90                 sid = tsec->sid;
91         rcu_read_unlock();
92         if (!tsec)
93                 return -EACCES;
94
95         return avc_has_perm(sid, SECINITSID_SECURITY,
96                             SECCLASS_SECURITY, perms, NULL);
97 }
98
99 enum sel_inos {
100         SEL_ROOT_INO = 2,
101         SEL_LOAD,       /* load policy */
102         SEL_ENFORCE,    /* get or set enforcing status */
103         SEL_CONTEXT,    /* validate context */
104         SEL_ACCESS,     /* compute access decision */
105         SEL_CREATE,     /* compute create labeling decision */
106         SEL_RELABEL,    /* compute relabeling decision */
107         SEL_USER,       /* compute reachable user contexts */
108         SEL_POLICYVERS, /* return policy version for this kernel */
109         SEL_COMMIT_BOOLS, /* commit new boolean values */
110         SEL_MLS,        /* return if MLS policy is enabled */
111         SEL_DISABLE,    /* disable SELinux until next reboot */
112         SEL_MEMBER,     /* compute polyinstantiation membership decision */
113         SEL_CHECKREQPROT, /* check requested protection, not kernel-applied one */
114         SEL_COMPAT_NET, /* whether to use old compat network packet controls */
115         SEL_REJECT_UNKNOWN, /* export unknown reject handling to userspace */
116         SEL_DENY_UNKNOWN, /* export unknown deny handling to userspace */
117         SEL_STATUS,     /* export current status using mmap() */
118         SEL_POLICY,     /* allow userspace to read the in kernel policy */
119         SEL_INO_NEXT,   /* The next inode number to use */
120 };
121
122 static unsigned long sel_last_ino = SEL_INO_NEXT - 1;
123
124 #define SEL_INITCON_INO_OFFSET          0x01000000
125 #define SEL_BOOL_INO_OFFSET             0x02000000
126 #define SEL_CLASS_INO_OFFSET            0x04000000
127 #define SEL_POLICYCAP_INO_OFFSET        0x08000000
128 #define SEL_INO_MASK                    0x00ffffff
129
130 #define TMPBUFLEN       12
131 static ssize_t sel_read_enforce(struct file *filp, char __user *buf,
132                                 size_t count, loff_t *ppos)
133 {
134         char tmpbuf[TMPBUFLEN];
135         ssize_t length;
136
137         length = scnprintf(tmpbuf, TMPBUFLEN, "%d", selinux_enforcing);
138         return simple_read_from_buffer(buf, count, ppos, tmpbuf, length);
139 }
140
141 #ifdef CONFIG_SECURITY_SELINUX_DEVELOP
142 static ssize_t sel_write_enforce(struct file *file, const char __user *buf,
143                                  size_t count, loff_t *ppos)
144
145 {
146         char *page = NULL;
147         ssize_t length;
148         int new_value;
149
150         length = -ENOMEM;
151         if (count >= PAGE_SIZE)
152                 goto out;
153
154         /* No partial writes. */
155         length = EINVAL;
156         if (*ppos != 0)
157                 goto out;
158
159         length = -ENOMEM;
160         page = (char *)get_zeroed_page(GFP_KERNEL);
161         if (!page)
162                 goto out;
163
164         length = -EFAULT;
165         if (copy_from_user(page, buf, count))
166                 goto out;
167
168         length = -EINVAL;
169         if (sscanf(page, "%d", &new_value) != 1)
170                 goto out;
171
172         if (new_value != selinux_enforcing) {
173                 length = task_has_security(current, SECURITY__SETENFORCE);
174                 if (length)
175                         goto out;
176                 audit_log(current->audit_context, GFP_KERNEL, AUDIT_MAC_STATUS,
177                         "enforcing=%d old_enforcing=%d auid=%u ses=%u",
178                         new_value, selinux_enforcing,
179                         audit_get_loginuid(current),
180                         audit_get_sessionid(current));
181                 selinux_enforcing = new_value;
182                 if (selinux_enforcing)
183                         avc_ss_reset(0);
184                 selnl_notify_setenforce(selinux_enforcing);
185                 selinux_status_update_setenforce(selinux_enforcing);
186         }
187         length = count;
188 out:
189         free_page((unsigned long) page);
190         return length;
191 }
192 #else
193 #define sel_write_enforce NULL
194 #endif
195
196 static const struct file_operations sel_enforce_ops = {
197         .read           = sel_read_enforce,
198         .write          = sel_write_enforce,
199         .llseek         = generic_file_llseek,
200 };
201
202 static ssize_t sel_read_handle_unknown(struct file *filp, char __user *buf,
203                                         size_t count, loff_t *ppos)
204 {
205         char tmpbuf[TMPBUFLEN];
206         ssize_t length;
207         ino_t ino = filp->f_path.dentry->d_inode->i_ino;
208         int handle_unknown = (ino == SEL_REJECT_UNKNOWN) ?
209                 security_get_reject_unknown() : !security_get_allow_unknown();
210
211         length = scnprintf(tmpbuf, TMPBUFLEN, "%d", handle_unknown);
212         return simple_read_from_buffer(buf, count, ppos, tmpbuf, length);
213 }
214
215 static const struct file_operations sel_handle_unknown_ops = {
216         .read           = sel_read_handle_unknown,
217         .llseek         = generic_file_llseek,
218 };
219
220 static int sel_open_handle_status(struct inode *inode, struct file *filp)
221 {
222         struct page    *status = selinux_kernel_status_page();
223
224         if (!status)
225                 return -ENOMEM;
226
227         filp->private_data = status;
228
229         return 0;
230 }
231
232 static ssize_t sel_read_handle_status(struct file *filp, char __user *buf,
233                                       size_t count, loff_t *ppos)
234 {
235         struct page    *status = filp->private_data;
236
237         BUG_ON(!status);
238
239         return simple_read_from_buffer(buf, count, ppos,
240                                        page_address(status),
241                                        sizeof(struct selinux_kernel_status));
242 }
243
244 static int sel_mmap_handle_status(struct file *filp,
245                                   struct vm_area_struct *vma)
246 {
247         struct page    *status = filp->private_data;
248         unsigned long   size = vma->vm_end - vma->vm_start;
249
250         BUG_ON(!status);
251
252         /* only allows one page from the head */
253         if (vma->vm_pgoff > 0 || size != PAGE_SIZE)
254                 return -EIO;
255         /* disallow writable mapping */
256         if (vma->vm_flags & VM_WRITE)
257                 return -EPERM;
258         /* disallow mprotect() turns it into writable */
259         vma->vm_flags &= ~VM_MAYWRITE;
260
261         return remap_pfn_range(vma, vma->vm_start,
262                                page_to_pfn(status),
263                                size, vma->vm_page_prot);
264 }
265
266 static const struct file_operations sel_handle_status_ops = {
267         .open           = sel_open_handle_status,
268         .read           = sel_read_handle_status,
269         .mmap           = sel_mmap_handle_status,
270         .llseek         = generic_file_llseek,
271 };
272
273 #ifdef CONFIG_SECURITY_SELINUX_DISABLE
274 static ssize_t sel_write_disable(struct file *file, const char __user *buf,
275                                  size_t count, loff_t *ppos)
276
277 {
278         char *page = NULL;
279         ssize_t length;
280         int new_value;
281         extern int selinux_disable(void);
282
283         length = -ENOMEM;
284         if (count >= PAGE_SIZE)
285                 goto out;
286
287         /* No partial writes. */
288         length = -EINVAL;
289         if (*ppos != 0)
290                 goto out;
291
292         length = -ENOMEM;
293         page = (char *)get_zeroed_page(GFP_KERNEL);
294         if (!page)
295                 goto out;
296
297         length = -EFAULT;
298         if (copy_from_user(page, buf, count))
299                 goto out;
300
301         length = -EINVAL;
302         if (sscanf(page, "%d", &new_value) != 1)
303                 goto out;
304
305         if (new_value) {
306                 length = selinux_disable();
307                 if (length)
308                         goto out;
309                 audit_log(current->audit_context, GFP_KERNEL, AUDIT_MAC_STATUS,
310                         "selinux=0 auid=%u ses=%u",
311                         audit_get_loginuid(current),
312                         audit_get_sessionid(current));
313         }
314
315         length = count;
316 out:
317         free_page((unsigned long) page);
318         return length;
319 }
320 #else
321 #define sel_write_disable NULL
322 #endif
323
324 static const struct file_operations sel_disable_ops = {
325         .write          = sel_write_disable,
326         .llseek         = generic_file_llseek,
327 };
328
329 static ssize_t sel_read_policyvers(struct file *filp, char __user *buf,
330                                    size_t count, loff_t *ppos)
331 {
332         char tmpbuf[TMPBUFLEN];
333         ssize_t length;
334
335         length = scnprintf(tmpbuf, TMPBUFLEN, "%u", POLICYDB_VERSION_MAX);
336         return simple_read_from_buffer(buf, count, ppos, tmpbuf, length);
337 }
338
339 static const struct file_operations sel_policyvers_ops = {
340         .read           = sel_read_policyvers,
341         .llseek         = generic_file_llseek,
342 };
343
344 /* declaration for sel_write_load */
345 static int sel_make_bools(void);
346 static int sel_make_classes(void);
347 static int sel_make_policycap(void);
348
349 /* declaration for sel_make_class_dirs */
350 static int sel_make_dir(struct inode *dir, struct dentry *dentry,
351                         unsigned long *ino);
352
353 static ssize_t sel_read_mls(struct file *filp, char __user *buf,
354                                 size_t count, loff_t *ppos)
355 {
356         char tmpbuf[TMPBUFLEN];
357         ssize_t length;
358
359         length = scnprintf(tmpbuf, TMPBUFLEN, "%d",
360                            security_mls_enabled());
361         return simple_read_from_buffer(buf, count, ppos, tmpbuf, length);
362 }
363
364 static const struct file_operations sel_mls_ops = {
365         .read           = sel_read_mls,
366         .llseek         = generic_file_llseek,
367 };
368
369 struct policy_load_memory {
370         size_t len;
371         void *data;
372 };
373
374 static int sel_open_policy(struct inode *inode, struct file *filp)
375 {
376         struct policy_load_memory *plm = NULL;
377         int rc;
378
379         BUG_ON(filp->private_data);
380
381         mutex_lock(&sel_mutex);
382
383         rc = task_has_security(current, SECURITY__READ_POLICY);
384         if (rc)
385                 goto err;
386
387         rc = -EBUSY;
388         if (policy_opened)
389                 goto err;
390
391         rc = -ENOMEM;
392         plm = kzalloc(sizeof(*plm), GFP_KERNEL);
393         if (!plm)
394                 goto err;
395
396         if (i_size_read(inode) != security_policydb_len()) {
397                 mutex_lock(&inode->i_mutex);
398                 i_size_write(inode, security_policydb_len());
399                 mutex_unlock(&inode->i_mutex);
400         }
401
402         rc = security_read_policy(&plm->data, &plm->len);
403         if (rc)
404                 goto err;
405
406         policy_opened = 1;
407
408         filp->private_data = plm;
409
410         mutex_unlock(&sel_mutex);
411
412         return 0;
413 err:
414         mutex_unlock(&sel_mutex);
415
416         if (plm)
417                 vfree(plm->data);
418         kfree(plm);
419         return rc;
420 }
421
422 static int sel_release_policy(struct inode *inode, struct file *filp)
423 {
424         struct policy_load_memory *plm = filp->private_data;
425
426         BUG_ON(!plm);
427
428         policy_opened = 0;
429
430         vfree(plm->data);
431         kfree(plm);
432
433         return 0;
434 }
435
436 static ssize_t sel_read_policy(struct file *filp, char __user *buf,
437                                size_t count, loff_t *ppos)
438 {
439         struct policy_load_memory *plm = filp->private_data;
440         int ret;
441
442         mutex_lock(&sel_mutex);
443
444         ret = task_has_security(current, SECURITY__READ_POLICY);
445         if (ret)
446                 goto out;
447
448         ret = simple_read_from_buffer(buf, count, ppos, plm->data, plm->len);
449 out:
450         mutex_unlock(&sel_mutex);
451         return ret;
452 }
453
454 static int sel_mmap_policy_fault(struct vm_area_struct *vma,
455                                  struct vm_fault *vmf)
456 {
457         struct policy_load_memory *plm = vma->vm_file->private_data;
458         unsigned long offset;
459         struct page *page;
460
461         if (vmf->flags & (FAULT_FLAG_MKWRITE | FAULT_FLAG_WRITE))
462                 return VM_FAULT_SIGBUS;
463
464         offset = vmf->pgoff << PAGE_SHIFT;
465         if (offset >= roundup(plm->len, PAGE_SIZE))
466                 return VM_FAULT_SIGBUS;
467
468         page = vmalloc_to_page(plm->data + offset);
469         get_page(page);
470
471         vmf->page = page;
472
473         return 0;
474 }
475
476 static struct vm_operations_struct sel_mmap_policy_ops = {
477         .fault = sel_mmap_policy_fault,
478         .page_mkwrite = sel_mmap_policy_fault,
479 };
480
481 int sel_mmap_policy(struct file *filp, struct vm_area_struct *vma)
482 {
483         if (vma->vm_flags & VM_SHARED) {
484                 /* do not allow mprotect to make mapping writable */
485                 vma->vm_flags &= ~VM_MAYWRITE;
486
487                 if (vma->vm_flags & VM_WRITE)
488                         return -EACCES;
489         }
490
491         vma->vm_flags |= VM_RESERVED;
492         vma->vm_ops = &sel_mmap_policy_ops;
493
494         return 0;
495 }
496
497 static const struct file_operations sel_policy_ops = {
498         .open           = sel_open_policy,
499         .read           = sel_read_policy,
500         .mmap           = sel_mmap_policy,
501         .release        = sel_release_policy,
502 };
503
504 static ssize_t sel_write_load(struct file *file, const char __user *buf,
505                               size_t count, loff_t *ppos)
506
507 {
508         ssize_t length;
509         void *data = NULL;
510
511         mutex_lock(&sel_mutex);
512
513         length = task_has_security(current, SECURITY__LOAD_POLICY);
514         if (length)
515                 goto out;
516
517         /* No partial writes. */
518         length = -EINVAL;
519         if (*ppos != 0)
520                 goto out;
521
522         length = -EFBIG;
523         if (count > 64 * 1024 * 1024)
524                 goto out;
525
526         length = -ENOMEM;
527         data = vmalloc(count);
528         if (!data)
529                 goto out;
530
531         length = -EFAULT;
532         if (copy_from_user(data, buf, count) != 0)
533                 goto out;
534
535         length = security_load_policy(data, count);
536         if (length)
537                 goto out;
538
539         length = sel_make_bools();
540         if (length)
541                 goto out1;
542
543         length = sel_make_classes();
544         if (length)
545                 goto out1;
546
547         length = sel_make_policycap();
548         if (length)
549                 goto out1;
550
551         length = count;
552
553 out1:
554         audit_log(current->audit_context, GFP_KERNEL, AUDIT_MAC_POLICY_LOAD,
555                 "policy loaded auid=%u ses=%u",
556                 audit_get_loginuid(current),
557                 audit_get_sessionid(current));
558 out:
559         mutex_unlock(&sel_mutex);
560         vfree(data);
561         return length;
562 }
563
564 static const struct file_operations sel_load_ops = {
565         .write          = sel_write_load,
566         .llseek         = generic_file_llseek,
567 };
568
569 static ssize_t sel_write_context(struct file *file, char *buf, size_t size)
570 {
571         char *canon = NULL;
572         u32 sid, len;
573         ssize_t length;
574
575         length = task_has_security(current, SECURITY__CHECK_CONTEXT);
576         if (length)
577                 goto out;
578
579         length = security_context_to_sid(buf, size, &sid);
580         if (length)
581                 goto out;
582
583         length = security_sid_to_context(sid, &canon, &len);
584         if (length)
585                 goto out;
586
587         length = -ERANGE;
588         if (len > SIMPLE_TRANSACTION_LIMIT) {
589                 printk(KERN_ERR "SELinux: %s:  context size (%u) exceeds "
590                         "payload max\n", __func__, len);
591                 goto out;
592         }
593
594         memcpy(buf, canon, len);
595         length = len;
596 out:
597         kfree(canon);
598         return length;
599 }
600
601 static ssize_t sel_read_checkreqprot(struct file *filp, char __user *buf,
602                                      size_t count, loff_t *ppos)
603 {
604         char tmpbuf[TMPBUFLEN];
605         ssize_t length;
606
607         length = scnprintf(tmpbuf, TMPBUFLEN, "%u", selinux_checkreqprot);
608         return simple_read_from_buffer(buf, count, ppos, tmpbuf, length);
609 }
610
611 static ssize_t sel_write_checkreqprot(struct file *file, const char __user *buf,
612                                       size_t count, loff_t *ppos)
613 {
614         char *page = NULL;
615         ssize_t length;
616         unsigned int new_value;
617
618         length = task_has_security(current, SECURITY__SETCHECKREQPROT);
619         if (length)
620                 goto out;
621
622         length = -ENOMEM;
623         if (count >= PAGE_SIZE)
624                 goto out;
625
626         /* No partial writes. */
627         length = -EINVAL;
628         if (*ppos != 0)
629                 goto out;
630
631         length = -ENOMEM;
632         page = (char *)get_zeroed_page(GFP_KERNEL);
633         if (!page)
634                 goto out;
635
636         length = -EFAULT;
637         if (copy_from_user(page, buf, count))
638                 goto out;
639
640         length = -EINVAL;
641         if (sscanf(page, "%u", &new_value) != 1)
642                 goto out;
643
644         selinux_checkreqprot = new_value ? 1 : 0;
645         length = count;
646 out:
647         free_page((unsigned long) page);
648         return length;
649 }
650 static const struct file_operations sel_checkreqprot_ops = {
651         .read           = sel_read_checkreqprot,
652         .write          = sel_write_checkreqprot,
653         .llseek         = generic_file_llseek,
654 };
655
656 /*
657  * Remaining nodes use transaction based IO methods like nfsd/nfsctl.c
658  */
659 static ssize_t sel_write_access(struct file *file, char *buf, size_t size);
660 static ssize_t sel_write_create(struct file *file, char *buf, size_t size);
661 static ssize_t sel_write_relabel(struct file *file, char *buf, size_t size);
662 static ssize_t sel_write_user(struct file *file, char *buf, size_t size);
663 static ssize_t sel_write_member(struct file *file, char *buf, size_t size);
664
665 static ssize_t (*write_op[])(struct file *, char *, size_t) = {
666         [SEL_ACCESS] = sel_write_access,
667         [SEL_CREATE] = sel_write_create,
668         [SEL_RELABEL] = sel_write_relabel,
669         [SEL_USER] = sel_write_user,
670         [SEL_MEMBER] = sel_write_member,
671         [SEL_CONTEXT] = sel_write_context,
672 };
673
674 static ssize_t selinux_transaction_write(struct file *file, const char __user *buf, size_t size, loff_t *pos)
675 {
676         ino_t ino = file->f_path.dentry->d_inode->i_ino;
677         char *data;
678         ssize_t rv;
679
680         if (ino >= ARRAY_SIZE(write_op) || !write_op[ino])
681                 return -EINVAL;
682
683         data = simple_transaction_get(file, buf, size);
684         if (IS_ERR(data))
685                 return PTR_ERR(data);
686
687         rv = write_op[ino](file, data, size);
688         if (rv > 0) {
689                 simple_transaction_set(file, rv);
690                 rv = size;
691         }
692         return rv;
693 }
694
695 static const struct file_operations transaction_ops = {
696         .write          = selinux_transaction_write,
697         .read           = simple_transaction_read,
698         .release        = simple_transaction_release,
699         .llseek         = generic_file_llseek,
700 };
701
702 /*
703  * payload - write methods
704  * If the method has a response, the response should be put in buf,
705  * and the length returned.  Otherwise return 0 or and -error.
706  */
707
708 static ssize_t sel_write_access(struct file *file, char *buf, size_t size)
709 {
710         char *scon = NULL, *tcon = NULL;
711         u32 ssid, tsid;
712         u16 tclass;
713         struct av_decision avd;
714         ssize_t length;
715
716         length = task_has_security(current, SECURITY__COMPUTE_AV);
717         if (length)
718                 goto out;
719
720         length = -ENOMEM;
721         scon = kzalloc(size + 1, GFP_KERNEL);
722         if (!scon)
723                 goto out;
724
725         length = -ENOMEM;
726         tcon = kzalloc(size + 1, GFP_KERNEL);
727         if (!tcon)
728                 goto out;
729
730         length = -EINVAL;
731         if (sscanf(buf, "%s %s %hu", scon, tcon, &tclass) != 3)
732                 goto out;
733
734         length = security_context_to_sid(scon, strlen(scon) + 1, &ssid);
735         if (length)
736                 goto out;
737
738         length = security_context_to_sid(tcon, strlen(tcon) + 1, &tsid);
739         if (length)
740                 goto out;
741
742         security_compute_av_user(ssid, tsid, tclass, &avd);
743
744         length = scnprintf(buf, SIMPLE_TRANSACTION_LIMIT,
745                           "%x %x %x %x %u %x",
746                           avd.allowed, 0xffffffff,
747                           avd.auditallow, avd.auditdeny,
748                           avd.seqno, avd.flags);
749 out:
750         kfree(tcon);
751         kfree(scon);
752         return length;
753 }
754
755 static inline int hexcode_to_int(int code) {
756         if (code == '\0' || !isxdigit(code))
757                 return -1;
758         if (isdigit(code))
759                 return code - '0';
760         return tolower(code) - 'a' + 10;
761 }
762
763 static ssize_t sel_write_create(struct file *file, char *buf, size_t size)
764 {
765         char *scon = NULL, *tcon = NULL;
766         char *namebuf = NULL, *objname = NULL;
767         u32 ssid, tsid, newsid;
768         u16 tclass;
769         ssize_t length;
770         char *newcon = NULL;
771         u32 len;
772         int nargs;
773
774         length = task_has_security(current, SECURITY__COMPUTE_CREATE);
775         if (length)
776                 goto out;
777
778         length = -ENOMEM;
779         scon = kzalloc(size + 1, GFP_KERNEL);
780         if (!scon)
781                 goto out;
782
783         length = -ENOMEM;
784         tcon = kzalloc(size + 1, GFP_KERNEL);
785         if (!tcon)
786                 goto out;
787
788         length = -ENOMEM;
789         namebuf = kzalloc(size + 1, GFP_KERNEL);
790         if (!namebuf)
791                 goto out;
792
793         length = -EINVAL;
794         nargs = sscanf(buf, "%s %s %hu %s", scon, tcon, &tclass, namebuf);
795         if (nargs < 3 || nargs > 4)
796                 goto out;
797         if (nargs == 4) {
798                 /*
799                  * If and when the name of new object to be queried contains
800                  * either whitespace or multibyte characters, they shall be
801                  * encoded based on the percentage-encoding rule.
802                  * If not encoded, the sscanf logic picks up only left-half
803                  * of the supplied name; splitted by a whitespace unexpectedly.
804                  */
805                 char   *r, *w;
806                 int     c1, c2;
807
808                 r = w = namebuf;
809                 do {
810                         c1 = *r++;
811                         if (c1 == '+')
812                                 c1 = ' ';
813                         else if (c1 == '%') {
814                                 if ((c1 = hexcode_to_int(*r++)) < 0)
815                                         goto out;
816                                 if ((c2 = hexcode_to_int(*r++)) < 0)
817                                         goto out;
818                                 c1 = (c1 << 4) | c2;
819                         }
820                         *w++ = c1;
821                 } while (c1 != '\0');
822
823                 objname = namebuf;
824         }
825
826         length = security_context_to_sid(scon, strlen(scon) + 1, &ssid);
827         if (length)
828                 goto out;
829
830         length = security_context_to_sid(tcon, strlen(tcon) + 1, &tsid);
831         if (length)
832                 goto out;
833
834         length = security_transition_sid_user(ssid, tsid, tclass,
835                                               objname, &newsid);
836         if (length)
837                 goto out;
838
839         length = security_sid_to_context(newsid, &newcon, &len);
840         if (length)
841                 goto out;
842
843         length = -ERANGE;
844         if (len > SIMPLE_TRANSACTION_LIMIT) {
845                 printk(KERN_ERR "SELinux: %s:  context size (%u) exceeds "
846                         "payload max\n", __func__, len);
847                 goto out;
848         }
849
850         memcpy(buf, newcon, len);
851         length = len;
852 out:
853         kfree(newcon);
854         kfree(namebuf);
855         kfree(tcon);
856         kfree(scon);
857         return length;
858 }
859
860 static ssize_t sel_write_relabel(struct file *file, char *buf, size_t size)
861 {
862         char *scon = NULL, *tcon = NULL;
863         u32 ssid, tsid, newsid;
864         u16 tclass;
865         ssize_t length;
866         char *newcon = NULL;
867         u32 len;
868
869         length = task_has_security(current, SECURITY__COMPUTE_RELABEL);
870         if (length)
871                 goto out;
872
873         length = -ENOMEM;
874         scon = kzalloc(size + 1, GFP_KERNEL);
875         if (!scon)
876                 goto out;
877
878         length = -ENOMEM;
879         tcon = kzalloc(size + 1, GFP_KERNEL);
880         if (!tcon)
881                 goto out;
882
883         length = -EINVAL;
884         if (sscanf(buf, "%s %s %hu", scon, tcon, &tclass) != 3)
885                 goto out;
886
887         length = security_context_to_sid(scon, strlen(scon) + 1, &ssid);
888         if (length)
889                 goto out;
890
891         length = security_context_to_sid(tcon, strlen(tcon) + 1, &tsid);
892         if (length)
893                 goto out;
894
895         length = security_change_sid(ssid, tsid, tclass, &newsid);
896         if (length)
897                 goto out;
898
899         length = security_sid_to_context(newsid, &newcon, &len);
900         if (length)
901                 goto out;
902
903         length = -ERANGE;
904         if (len > SIMPLE_TRANSACTION_LIMIT)
905                 goto out;
906
907         memcpy(buf, newcon, len);
908         length = len;
909 out:
910         kfree(newcon);
911         kfree(tcon);
912         kfree(scon);
913         return length;
914 }
915
916 static ssize_t sel_write_user(struct file *file, char *buf, size_t size)
917 {
918         char *con = NULL, *user = NULL, *ptr;
919         u32 sid, *sids = NULL;
920         ssize_t length;
921         char *newcon;
922         int i, rc;
923         u32 len, nsids;
924
925         length = task_has_security(current, SECURITY__COMPUTE_USER);
926         if (length)
927                 goto out;
928
929         length = -ENOMEM;
930         con = kzalloc(size + 1, GFP_KERNEL);
931         if (!con)
932                 goto out;
933
934         length = -ENOMEM;
935         user = kzalloc(size + 1, GFP_KERNEL);
936         if (!user)
937                 goto out;
938
939         length = -EINVAL;
940         if (sscanf(buf, "%s %s", con, user) != 2)
941                 goto out;
942
943         length = security_context_to_sid(con, strlen(con) + 1, &sid);
944         if (length)
945                 goto out;
946
947         length = security_get_user_sids(sid, user, &sids, &nsids);
948         if (length)
949                 goto out;
950
951         length = sprintf(buf, "%u", nsids) + 1;
952         ptr = buf + length;
953         for (i = 0; i < nsids; i++) {
954                 rc = security_sid_to_context(sids[i], &newcon, &len);
955                 if (rc) {
956                         length = rc;
957                         goto out;
958                 }
959                 if ((length + len) >= SIMPLE_TRANSACTION_LIMIT) {
960                         kfree(newcon);
961                         length = -ERANGE;
962                         goto out;
963                 }
964                 memcpy(ptr, newcon, len);
965                 kfree(newcon);
966                 ptr += len;
967                 length += len;
968         }
969 out:
970         kfree(sids);
971         kfree(user);
972         kfree(con);
973         return length;
974 }
975
976 static ssize_t sel_write_member(struct file *file, char *buf, size_t size)
977 {
978         char *scon = NULL, *tcon = NULL;
979         u32 ssid, tsid, newsid;
980         u16 tclass;
981         ssize_t length;
982         char *newcon = NULL;
983         u32 len;
984
985         length = task_has_security(current, SECURITY__COMPUTE_MEMBER);
986         if (length)
987                 goto out;
988
989         length = -ENOMEM;
990         scon = kzalloc(size + 1, GFP_KERNEL);
991         if (!scon)
992                 goto out;
993
994         length = -ENOMEM;
995         tcon = kzalloc(size + 1, GFP_KERNEL);
996         if (!tcon)
997                 goto out;
998
999         length = -EINVAL;
1000         if (sscanf(buf, "%s %s %hu", scon, tcon, &tclass) != 3)
1001                 goto out;
1002
1003         length = security_context_to_sid(scon, strlen(scon) + 1, &ssid);
1004         if (length)
1005                 goto out;
1006
1007         length = security_context_to_sid(tcon, strlen(tcon) + 1, &tsid);
1008         if (length)
1009                 goto out;
1010
1011         length = security_member_sid(ssid, tsid, tclass, &newsid);
1012         if (length)
1013                 goto out;
1014
1015         length = security_sid_to_context(newsid, &newcon, &len);
1016         if (length)
1017                 goto out;
1018
1019         length = -ERANGE;
1020         if (len > SIMPLE_TRANSACTION_LIMIT) {
1021                 printk(KERN_ERR "SELinux: %s:  context size (%u) exceeds "
1022                         "payload max\n", __func__, len);
1023                 goto out;
1024         }
1025
1026         memcpy(buf, newcon, len);
1027         length = len;
1028 out:
1029         kfree(newcon);
1030         kfree(tcon);
1031         kfree(scon);
1032         return length;
1033 }
1034
1035 static struct inode *sel_make_inode(struct super_block *sb, int mode)
1036 {
1037         struct inode *ret = new_inode(sb);
1038
1039         if (ret) {
1040                 ret->i_mode = mode;
1041                 ret->i_atime = ret->i_mtime = ret->i_ctime = CURRENT_TIME;
1042         }
1043         return ret;
1044 }
1045
1046 static ssize_t sel_read_bool(struct file *filep, char __user *buf,
1047                              size_t count, loff_t *ppos)
1048 {
1049         char *page = NULL;
1050         ssize_t length;
1051         ssize_t ret;
1052         int cur_enforcing;
1053         struct inode *inode = filep->f_path.dentry->d_inode;
1054         unsigned index = inode->i_ino & SEL_INO_MASK;
1055         const char *name = filep->f_path.dentry->d_name.name;
1056
1057         mutex_lock(&sel_mutex);
1058
1059         ret = -EINVAL;
1060         if (index >= bool_num || strcmp(name, bool_pending_names[index]))
1061                 goto out;
1062
1063         ret = -ENOMEM;
1064         page = (char *)get_zeroed_page(GFP_KERNEL);
1065         if (!page)
1066                 goto out;
1067
1068         cur_enforcing = security_get_bool_value(index);
1069         if (cur_enforcing < 0) {
1070                 ret = cur_enforcing;
1071                 goto out;
1072         }
1073         length = scnprintf(page, PAGE_SIZE, "%d %d", cur_enforcing,
1074                           bool_pending_values[index]);
1075         ret = simple_read_from_buffer(buf, count, ppos, page, length);
1076 out:
1077         mutex_unlock(&sel_mutex);
1078         free_page((unsigned long)page);
1079         return ret;
1080 }
1081
1082 static ssize_t sel_write_bool(struct file *filep, const char __user *buf,
1083                               size_t count, loff_t *ppos)
1084 {
1085         char *page = NULL;
1086         ssize_t length;
1087         int new_value;
1088         struct inode *inode = filep->f_path.dentry->d_inode;
1089         unsigned index = inode->i_ino & SEL_INO_MASK;
1090         const char *name = filep->f_path.dentry->d_name.name;
1091
1092         mutex_lock(&sel_mutex);
1093
1094         length = task_has_security(current, SECURITY__SETBOOL);
1095         if (length)
1096                 goto out;
1097
1098         length = -EINVAL;
1099         if (index >= bool_num || strcmp(name, bool_pending_names[index]))
1100                 goto out;
1101
1102         length = -ENOMEM;
1103         if (count >= PAGE_SIZE)
1104                 goto out;
1105
1106         /* No partial writes. */
1107         length = -EINVAL;
1108         if (*ppos != 0)
1109                 goto out;
1110
1111         length = -ENOMEM;
1112         page = (char *)get_zeroed_page(GFP_KERNEL);
1113         if (!page)
1114                 goto out;
1115
1116         length = -EFAULT;
1117         if (copy_from_user(page, buf, count))
1118                 goto out;
1119
1120         length = -EINVAL;
1121         if (sscanf(page, "%d", &new_value) != 1)
1122                 goto out;
1123
1124         if (new_value)
1125                 new_value = 1;
1126
1127         bool_pending_values[index] = new_value;
1128         length = count;
1129
1130 out:
1131         mutex_unlock(&sel_mutex);
1132         free_page((unsigned long) page);
1133         return length;
1134 }
1135
1136 static const struct file_operations sel_bool_ops = {
1137         .read           = sel_read_bool,
1138         .write          = sel_write_bool,
1139         .llseek         = generic_file_llseek,
1140 };
1141
1142 static ssize_t sel_commit_bools_write(struct file *filep,
1143                                       const char __user *buf,
1144                                       size_t count, loff_t *ppos)
1145 {
1146         char *page = NULL;
1147         ssize_t length;
1148         int new_value;
1149
1150         mutex_lock(&sel_mutex);
1151
1152         length = task_has_security(current, SECURITY__SETBOOL);
1153         if (length)
1154                 goto out;
1155
1156         length = -ENOMEM;
1157         if (count >= PAGE_SIZE)
1158                 goto out;
1159
1160         /* No partial writes. */
1161         length = -EINVAL;
1162         if (*ppos != 0)
1163                 goto out;
1164
1165         length = -ENOMEM;
1166         page = (char *)get_zeroed_page(GFP_KERNEL);
1167         if (!page)
1168                 goto out;
1169
1170         length = -EFAULT;
1171         if (copy_from_user(page, buf, count))
1172                 goto out;
1173
1174         length = -EINVAL;
1175         if (sscanf(page, "%d", &new_value) != 1)
1176                 goto out;
1177
1178         length = 0;
1179         if (new_value && bool_pending_values)
1180                 length = security_set_bools(bool_num, bool_pending_values);
1181
1182         if (!length)
1183                 length = count;
1184
1185 out:
1186         mutex_unlock(&sel_mutex);
1187         free_page((unsigned long) page);
1188         return length;
1189 }
1190
1191 static const struct file_operations sel_commit_bools_ops = {
1192         .write          = sel_commit_bools_write,
1193         .llseek         = generic_file_llseek,
1194 };
1195
1196 static void sel_remove_entries(struct dentry *de)
1197 {
1198         struct list_head *node;
1199
1200         spin_lock(&de->d_lock);
1201         node = de->d_subdirs.next;
1202         while (node != &de->d_subdirs) {
1203                 struct dentry *d = list_entry(node, struct dentry, d_u.d_child);
1204
1205                 spin_lock_nested(&d->d_lock, DENTRY_D_LOCK_NESTED);
1206                 list_del_init(node);
1207
1208                 if (d->d_inode) {
1209                         dget_dlock(d);
1210                         spin_unlock(&de->d_lock);
1211                         spin_unlock(&d->d_lock);
1212                         d_delete(d);
1213                         simple_unlink(de->d_inode, d);
1214                         dput(d);
1215                         spin_lock(&de->d_lock);
1216                 } else
1217                         spin_unlock(&d->d_lock);
1218                 node = de->d_subdirs.next;
1219         }
1220
1221         spin_unlock(&de->d_lock);
1222 }
1223
1224 #define BOOL_DIR_NAME "booleans"
1225
1226 static int sel_make_bools(void)
1227 {
1228         int i, ret;
1229         ssize_t len;
1230         struct dentry *dentry = NULL;
1231         struct dentry *dir = bool_dir;
1232         struct inode *inode = NULL;
1233         struct inode_security_struct *isec;
1234         char **names = NULL, *page;
1235         int num;
1236         int *values = NULL;
1237         u32 sid;
1238
1239         /* remove any existing files */
1240         for (i = 0; i < bool_num; i++)
1241                 kfree(bool_pending_names[i]);
1242         kfree(bool_pending_names);
1243         kfree(bool_pending_values);
1244         bool_pending_names = NULL;
1245         bool_pending_values = NULL;
1246
1247         sel_remove_entries(dir);
1248
1249         ret = -ENOMEM;
1250         page = (char *)get_zeroed_page(GFP_KERNEL);
1251         if (!page)
1252                 goto out;
1253
1254         ret = security_get_bools(&num, &names, &values);
1255         if (ret)
1256                 goto out;
1257
1258         for (i = 0; i < num; i++) {
1259                 ret = -ENOMEM;
1260                 dentry = d_alloc_name(dir, names[i]);
1261                 if (!dentry)
1262                         goto out;
1263
1264                 ret = -ENOMEM;
1265                 inode = sel_make_inode(dir->d_sb, S_IFREG | S_IRUGO | S_IWUSR);
1266                 if (!inode)
1267                         goto out;
1268
1269                 ret = -EINVAL;
1270                 len = snprintf(page, PAGE_SIZE, "/%s/%s", BOOL_DIR_NAME, names[i]);
1271                 if (len < 0)
1272                         goto out;
1273
1274                 ret = -ENAMETOOLONG;
1275                 if (len >= PAGE_SIZE)
1276                         goto out;
1277
1278                 isec = (struct inode_security_struct *)inode->i_security;
1279                 ret = security_genfs_sid("selinuxfs", page, SECCLASS_FILE, &sid);
1280                 if (ret)
1281                         goto out;
1282
1283                 isec->sid = sid;
1284                 isec->initialized = 1;
1285                 inode->i_fop = &sel_bool_ops;
1286                 inode->i_ino = i|SEL_BOOL_INO_OFFSET;
1287                 d_add(dentry, inode);
1288         }
1289         bool_num = num;
1290         bool_pending_names = names;
1291         bool_pending_values = values;
1292
1293         free_page((unsigned long)page);
1294         return 0;
1295 out:
1296         free_page((unsigned long)page);
1297
1298         if (names) {
1299                 for (i = 0; i < num; i++)
1300                         kfree(names[i]);
1301                 kfree(names);
1302         }
1303         kfree(values);
1304         sel_remove_entries(dir);
1305
1306         return ret;
1307 }
1308
1309 #define NULL_FILE_NAME "null"
1310
1311 struct dentry *selinux_null;
1312
1313 static ssize_t sel_read_avc_cache_threshold(struct file *filp, char __user *buf,
1314                                             size_t count, loff_t *ppos)
1315 {
1316         char tmpbuf[TMPBUFLEN];
1317         ssize_t length;
1318
1319         length = scnprintf(tmpbuf, TMPBUFLEN, "%u", avc_cache_threshold);
1320         return simple_read_from_buffer(buf, count, ppos, tmpbuf, length);
1321 }
1322
1323 static ssize_t sel_write_avc_cache_threshold(struct file *file,
1324                                              const char __user *buf,
1325                                              size_t count, loff_t *ppos)
1326
1327 {
1328         char *page = NULL;
1329         ssize_t ret;
1330         int new_value;
1331
1332         ret = task_has_security(current, SECURITY__SETSECPARAM);
1333         if (ret)
1334                 goto out;
1335
1336         ret = -ENOMEM;
1337         if (count >= PAGE_SIZE)
1338                 goto out;
1339
1340         /* No partial writes. */
1341         ret = -EINVAL;
1342         if (*ppos != 0)
1343                 goto out;
1344
1345         ret = -ENOMEM;
1346         page = (char *)get_zeroed_page(GFP_KERNEL);
1347         if (!page)
1348                 goto out;
1349
1350         ret = -EFAULT;
1351         if (copy_from_user(page, buf, count))
1352                 goto out;
1353
1354         ret = -EINVAL;
1355         if (sscanf(page, "%u", &new_value) != 1)
1356                 goto out;
1357
1358         avc_cache_threshold = new_value;
1359
1360         ret = count;
1361 out:
1362         free_page((unsigned long)page);
1363         return ret;
1364 }
1365
1366 static ssize_t sel_read_avc_hash_stats(struct file *filp, char __user *buf,
1367                                        size_t count, loff_t *ppos)
1368 {
1369         char *page;
1370         ssize_t length;
1371
1372         page = (char *)__get_free_page(GFP_KERNEL);
1373         if (!page)
1374                 return -ENOMEM;
1375
1376         length = avc_get_hash_stats(page);
1377         if (length >= 0)
1378                 length = simple_read_from_buffer(buf, count, ppos, page, length);
1379         free_page((unsigned long)page);
1380
1381         return length;
1382 }
1383
1384 static const struct file_operations sel_avc_cache_threshold_ops = {
1385         .read           = sel_read_avc_cache_threshold,
1386         .write          = sel_write_avc_cache_threshold,
1387         .llseek         = generic_file_llseek,
1388 };
1389
1390 static const struct file_operations sel_avc_hash_stats_ops = {
1391         .read           = sel_read_avc_hash_stats,
1392         .llseek         = generic_file_llseek,
1393 };
1394
1395 #ifdef CONFIG_SECURITY_SELINUX_AVC_STATS
1396 static struct avc_cache_stats *sel_avc_get_stat_idx(loff_t *idx)
1397 {
1398         int cpu;
1399
1400         for (cpu = *idx; cpu < nr_cpu_ids; ++cpu) {
1401                 if (!cpu_possible(cpu))
1402                         continue;
1403                 *idx = cpu + 1;
1404                 return &per_cpu(avc_cache_stats, cpu);
1405         }
1406         return NULL;
1407 }
1408
1409 static void *sel_avc_stats_seq_start(struct seq_file *seq, loff_t *pos)
1410 {
1411         loff_t n = *pos - 1;
1412
1413         if (*pos == 0)
1414                 return SEQ_START_TOKEN;
1415
1416         return sel_avc_get_stat_idx(&n);
1417 }
1418
1419 static void *sel_avc_stats_seq_next(struct seq_file *seq, void *v, loff_t *pos)
1420 {
1421         return sel_avc_get_stat_idx(pos);
1422 }
1423
1424 static int sel_avc_stats_seq_show(struct seq_file *seq, void *v)
1425 {
1426         struct avc_cache_stats *st = v;
1427
1428         if (v == SEQ_START_TOKEN)
1429                 seq_printf(seq, "lookups hits misses allocations reclaims "
1430                            "frees\n");
1431         else {
1432                 unsigned int lookups = st->lookups;
1433                 unsigned int misses = st->misses;
1434                 unsigned int hits = lookups - misses;
1435                 seq_printf(seq, "%u %u %u %u %u %u\n", lookups,
1436                            hits, misses, st->allocations,
1437                            st->reclaims, st->frees);
1438         }
1439         return 0;
1440 }
1441
1442 static void sel_avc_stats_seq_stop(struct seq_file *seq, void *v)
1443 { }
1444
1445 static const struct seq_operations sel_avc_cache_stats_seq_ops = {
1446         .start          = sel_avc_stats_seq_start,
1447         .next           = sel_avc_stats_seq_next,
1448         .show           = sel_avc_stats_seq_show,
1449         .stop           = sel_avc_stats_seq_stop,
1450 };
1451
1452 static int sel_open_avc_cache_stats(struct inode *inode, struct file *file)
1453 {
1454         return seq_open(file, &sel_avc_cache_stats_seq_ops);
1455 }
1456
1457 static const struct file_operations sel_avc_cache_stats_ops = {
1458         .open           = sel_open_avc_cache_stats,
1459         .read           = seq_read,
1460         .llseek         = seq_lseek,
1461         .release        = seq_release,
1462 };
1463 #endif
1464
1465 static int sel_make_avc_files(struct dentry *dir)
1466 {
1467         int i;
1468         static struct tree_descr files[] = {
1469                 { "cache_threshold",
1470                   &sel_avc_cache_threshold_ops, S_IRUGO|S_IWUSR },
1471                 { "hash_stats", &sel_avc_hash_stats_ops, S_IRUGO },
1472 #ifdef CONFIG_SECURITY_SELINUX_AVC_STATS
1473                 { "cache_stats", &sel_avc_cache_stats_ops, S_IRUGO },
1474 #endif
1475         };
1476
1477         for (i = 0; i < ARRAY_SIZE(files); i++) {
1478                 struct inode *inode;
1479                 struct dentry *dentry;
1480
1481                 dentry = d_alloc_name(dir, files[i].name);
1482                 if (!dentry)
1483                         return -ENOMEM;
1484
1485                 inode = sel_make_inode(dir->d_sb, S_IFREG|files[i].mode);
1486                 if (!inode)
1487                         return -ENOMEM;
1488
1489                 inode->i_fop = files[i].ops;
1490                 inode->i_ino = ++sel_last_ino;
1491                 d_add(dentry, inode);
1492         }
1493
1494         return 0;
1495 }
1496
1497 static ssize_t sel_read_initcon(struct file *file, char __user *buf,
1498                                 size_t count, loff_t *ppos)
1499 {
1500         struct inode *inode;
1501         char *con;
1502         u32 sid, len;
1503         ssize_t ret;
1504
1505         inode = file->f_path.dentry->d_inode;
1506         sid = inode->i_ino&SEL_INO_MASK;
1507         ret = security_sid_to_context(sid, &con, &len);
1508         if (ret)
1509                 return ret;
1510
1511         ret = simple_read_from_buffer(buf, count, ppos, con, len);
1512         kfree(con);
1513         return ret;
1514 }
1515
1516 static const struct file_operations sel_initcon_ops = {
1517         .read           = sel_read_initcon,
1518         .llseek         = generic_file_llseek,
1519 };
1520
1521 static int sel_make_initcon_files(struct dentry *dir)
1522 {
1523         int i;
1524
1525         for (i = 1; i <= SECINITSID_NUM; i++) {
1526                 struct inode *inode;
1527                 struct dentry *dentry;
1528                 dentry = d_alloc_name(dir, security_get_initial_sid_context(i));
1529                 if (!dentry)
1530                         return -ENOMEM;
1531
1532                 inode = sel_make_inode(dir->d_sb, S_IFREG|S_IRUGO);
1533                 if (!inode)
1534                         return -ENOMEM;
1535
1536                 inode->i_fop = &sel_initcon_ops;
1537                 inode->i_ino = i|SEL_INITCON_INO_OFFSET;
1538                 d_add(dentry, inode);
1539         }
1540
1541         return 0;
1542 }
1543
1544 static inline unsigned int sel_div(unsigned long a, unsigned long b)
1545 {
1546         return a / b - (a % b < 0);
1547 }
1548
1549 static inline unsigned long sel_class_to_ino(u16 class)
1550 {
1551         return (class * (SEL_VEC_MAX + 1)) | SEL_CLASS_INO_OFFSET;
1552 }
1553
1554 static inline u16 sel_ino_to_class(unsigned long ino)
1555 {
1556         return sel_div(ino & SEL_INO_MASK, SEL_VEC_MAX + 1);
1557 }
1558
1559 static inline unsigned long sel_perm_to_ino(u16 class, u32 perm)
1560 {
1561         return (class * (SEL_VEC_MAX + 1) + perm) | SEL_CLASS_INO_OFFSET;
1562 }
1563
1564 static inline u32 sel_ino_to_perm(unsigned long ino)
1565 {
1566         return (ino & SEL_INO_MASK) % (SEL_VEC_MAX + 1);
1567 }
1568
1569 static ssize_t sel_read_class(struct file *file, char __user *buf,
1570                                 size_t count, loff_t *ppos)
1571 {
1572         ssize_t rc, len;
1573         char *page;
1574         unsigned long ino = file->f_path.dentry->d_inode->i_ino;
1575
1576         page = (char *)__get_free_page(GFP_KERNEL);
1577         if (!page)
1578                 return -ENOMEM;
1579
1580         len = snprintf(page, PAGE_SIZE, "%d", sel_ino_to_class(ino));
1581         rc = simple_read_from_buffer(buf, count, ppos, page, len);
1582         free_page((unsigned long)page);
1583
1584         return rc;
1585 }
1586
1587 static const struct file_operations sel_class_ops = {
1588         .read           = sel_read_class,
1589         .llseek         = generic_file_llseek,
1590 };
1591
1592 static ssize_t sel_read_perm(struct file *file, char __user *buf,
1593                                 size_t count, loff_t *ppos)
1594 {
1595         ssize_t rc, len;
1596         char *page;
1597         unsigned long ino = file->f_path.dentry->d_inode->i_ino;
1598
1599         page = (char *)__get_free_page(GFP_KERNEL);
1600         if (!page)
1601                 return -ENOMEM;
1602
1603         len = snprintf(page, PAGE_SIZE, "%d", sel_ino_to_perm(ino));
1604         rc = simple_read_from_buffer(buf, count, ppos, page, len);
1605         free_page((unsigned long)page);
1606
1607         return rc;
1608 }
1609
1610 static const struct file_operations sel_perm_ops = {
1611         .read           = sel_read_perm,
1612         .llseek         = generic_file_llseek,
1613 };
1614
1615 static ssize_t sel_read_policycap(struct file *file, char __user *buf,
1616                                   size_t count, loff_t *ppos)
1617 {
1618         int value;
1619         char tmpbuf[TMPBUFLEN];
1620         ssize_t length;
1621         unsigned long i_ino = file->f_path.dentry->d_inode->i_ino;
1622
1623         value = security_policycap_supported(i_ino & SEL_INO_MASK);
1624         length = scnprintf(tmpbuf, TMPBUFLEN, "%d", value);
1625
1626         return simple_read_from_buffer(buf, count, ppos, tmpbuf, length);
1627 }
1628
1629 static const struct file_operations sel_policycap_ops = {
1630         .read           = sel_read_policycap,
1631         .llseek         = generic_file_llseek,
1632 };
1633
1634 static int sel_make_perm_files(char *objclass, int classvalue,
1635                                 struct dentry *dir)
1636 {
1637         int i, rc, nperms;
1638         char **perms;
1639
1640         rc = security_get_permissions(objclass, &perms, &nperms);
1641         if (rc)
1642                 return rc;
1643
1644         for (i = 0; i < nperms; i++) {
1645                 struct inode *inode;
1646                 struct dentry *dentry;
1647
1648                 rc = -ENOMEM;
1649                 dentry = d_alloc_name(dir, perms[i]);
1650                 if (!dentry)
1651                         goto out;
1652
1653                 rc = -ENOMEM;
1654                 inode = sel_make_inode(dir->d_sb, S_IFREG|S_IRUGO);
1655                 if (!inode)
1656                         goto out;
1657
1658                 inode->i_fop = &sel_perm_ops;
1659                 /* i+1 since perm values are 1-indexed */
1660                 inode->i_ino = sel_perm_to_ino(classvalue, i + 1);
1661                 d_add(dentry, inode);
1662         }
1663         rc = 0;
1664 out:
1665         for (i = 0; i < nperms; i++)
1666                 kfree(perms[i]);
1667         kfree(perms);
1668         return rc;
1669 }
1670
1671 static int sel_make_class_dir_entries(char *classname, int index,
1672                                         struct dentry *dir)
1673 {
1674         struct dentry *dentry = NULL;
1675         struct inode *inode = NULL;
1676         int rc;
1677
1678         dentry = d_alloc_name(dir, "index");
1679         if (!dentry)
1680                 return -ENOMEM;
1681
1682         inode = sel_make_inode(dir->d_sb, S_IFREG|S_IRUGO);
1683         if (!inode)
1684                 return -ENOMEM;
1685
1686         inode->i_fop = &sel_class_ops;
1687         inode->i_ino = sel_class_to_ino(index);
1688         d_add(dentry, inode);
1689
1690         dentry = d_alloc_name(dir, "perms");
1691         if (!dentry)
1692                 return -ENOMEM;
1693
1694         rc = sel_make_dir(dir->d_inode, dentry, &last_class_ino);
1695         if (rc)
1696                 return rc;
1697
1698         rc = sel_make_perm_files(classname, index, dentry);
1699
1700         return rc;
1701 }
1702
1703 static void sel_remove_classes(void)
1704 {
1705         struct list_head *class_node;
1706
1707         list_for_each(class_node, &class_dir->d_subdirs) {
1708                 struct dentry *class_subdir = list_entry(class_node,
1709                                         struct dentry, d_u.d_child);
1710                 struct list_head *class_subdir_node;
1711
1712                 list_for_each(class_subdir_node, &class_subdir->d_subdirs) {
1713                         struct dentry *d = list_entry(class_subdir_node,
1714                                                 struct dentry, d_u.d_child);
1715
1716                         if (d->d_inode)
1717                                 if (d->d_inode->i_mode & S_IFDIR)
1718                                         sel_remove_entries(d);
1719                 }
1720
1721                 sel_remove_entries(class_subdir);
1722         }
1723
1724         sel_remove_entries(class_dir);
1725 }
1726
1727 static int sel_make_classes(void)
1728 {
1729         int rc, nclasses, i;
1730         char **classes;
1731
1732         /* delete any existing entries */
1733         sel_remove_classes();
1734
1735         rc = security_get_classes(&classes, &nclasses);
1736         if (rc)
1737                 return rc;
1738
1739         /* +2 since classes are 1-indexed */
1740         last_class_ino = sel_class_to_ino(nclasses + 2);
1741
1742         for (i = 0; i < nclasses; i++) {
1743                 struct dentry *class_name_dir;
1744
1745                 rc = -ENOMEM;
1746                 class_name_dir = d_alloc_name(class_dir, classes[i]);
1747                 if (!class_name_dir)
1748                         goto out;
1749
1750                 rc = sel_make_dir(class_dir->d_inode, class_name_dir,
1751                                 &last_class_ino);
1752                 if (rc)
1753                         goto out;
1754
1755                 /* i+1 since class values are 1-indexed */
1756                 rc = sel_make_class_dir_entries(classes[i], i + 1,
1757                                 class_name_dir);
1758                 if (rc)
1759                         goto out;
1760         }
1761         rc = 0;
1762 out:
1763         for (i = 0; i < nclasses; i++)
1764                 kfree(classes[i]);
1765         kfree(classes);
1766         return rc;
1767 }
1768
1769 static int sel_make_policycap(void)
1770 {
1771         unsigned int iter;
1772         struct dentry *dentry = NULL;
1773         struct inode *inode = NULL;
1774
1775         sel_remove_entries(policycap_dir);
1776
1777         for (iter = 0; iter <= POLICYDB_CAPABILITY_MAX; iter++) {
1778                 if (iter < ARRAY_SIZE(policycap_names))
1779                         dentry = d_alloc_name(policycap_dir,
1780                                               policycap_names[iter]);
1781                 else
1782                         dentry = d_alloc_name(policycap_dir, "unknown");
1783
1784                 if (dentry == NULL)
1785                         return -ENOMEM;
1786
1787                 inode = sel_make_inode(policycap_dir->d_sb, S_IFREG | S_IRUGO);
1788                 if (inode == NULL)
1789                         return -ENOMEM;
1790
1791                 inode->i_fop = &sel_policycap_ops;
1792                 inode->i_ino = iter | SEL_POLICYCAP_INO_OFFSET;
1793                 d_add(dentry, inode);
1794         }
1795
1796         return 0;
1797 }
1798
1799 static int sel_make_dir(struct inode *dir, struct dentry *dentry,
1800                         unsigned long *ino)
1801 {
1802         struct inode *inode;
1803
1804         inode = sel_make_inode(dir->i_sb, S_IFDIR | S_IRUGO | S_IXUGO);
1805         if (!inode)
1806                 return -ENOMEM;
1807
1808         inode->i_op = &simple_dir_inode_operations;
1809         inode->i_fop = &simple_dir_operations;
1810         inode->i_ino = ++(*ino);
1811         /* directory inodes start off with i_nlink == 2 (for "." entry) */
1812         inc_nlink(inode);
1813         d_add(dentry, inode);
1814         /* bump link count on parent directory, too */
1815         inc_nlink(dir);
1816
1817         return 0;
1818 }
1819
1820 static int sel_fill_super(struct super_block *sb, void *data, int silent)
1821 {
1822         int ret;
1823         struct dentry *dentry;
1824         struct inode *inode, *root_inode;
1825         struct inode_security_struct *isec;
1826
1827         static struct tree_descr selinux_files[] = {
1828                 [SEL_LOAD] = {"load", &sel_load_ops, S_IRUSR|S_IWUSR},
1829                 [SEL_ENFORCE] = {"enforce", &sel_enforce_ops, S_IRUGO|S_IWUSR},
1830                 [SEL_CONTEXT] = {"context", &transaction_ops, S_IRUGO|S_IWUGO},
1831                 [SEL_ACCESS] = {"access", &transaction_ops, S_IRUGO|S_IWUGO},
1832                 [SEL_CREATE] = {"create", &transaction_ops, S_IRUGO|S_IWUGO},
1833                 [SEL_RELABEL] = {"relabel", &transaction_ops, S_IRUGO|S_IWUGO},
1834                 [SEL_USER] = {"user", &transaction_ops, S_IRUGO|S_IWUGO},
1835                 [SEL_POLICYVERS] = {"policyvers", &sel_policyvers_ops, S_IRUGO},
1836                 [SEL_COMMIT_BOOLS] = {"commit_pending_bools", &sel_commit_bools_ops, S_IWUSR},
1837                 [SEL_MLS] = {"mls", &sel_mls_ops, S_IRUGO},
1838                 [SEL_DISABLE] = {"disable", &sel_disable_ops, S_IWUSR},
1839                 [SEL_MEMBER] = {"member", &transaction_ops, S_IRUGO|S_IWUGO},
1840                 [SEL_CHECKREQPROT] = {"checkreqprot", &sel_checkreqprot_ops, S_IRUGO|S_IWUSR},
1841                 [SEL_REJECT_UNKNOWN] = {"reject_unknown", &sel_handle_unknown_ops, S_IRUGO},
1842                 [SEL_DENY_UNKNOWN] = {"deny_unknown", &sel_handle_unknown_ops, S_IRUGO},
1843                 [SEL_STATUS] = {"status", &sel_handle_status_ops, S_IRUGO},
1844                 [SEL_POLICY] = {"policy", &sel_policy_ops, S_IRUSR},
1845                 /* last one */ {""}
1846         };
1847         ret = simple_fill_super(sb, SELINUX_MAGIC, selinux_files);
1848         if (ret)
1849                 goto err;
1850
1851         root_inode = sb->s_root->d_inode;
1852
1853         ret = -ENOMEM;
1854         dentry = d_alloc_name(sb->s_root, BOOL_DIR_NAME);
1855         if (!dentry)
1856                 goto err;
1857
1858         ret = sel_make_dir(root_inode, dentry, &sel_last_ino);
1859         if (ret)
1860                 goto err;
1861
1862         bool_dir = dentry;
1863
1864         ret = -ENOMEM;
1865         dentry = d_alloc_name(sb->s_root, NULL_FILE_NAME);
1866         if (!dentry)
1867                 goto err;
1868
1869         ret = -ENOMEM;
1870         inode = sel_make_inode(sb, S_IFCHR | S_IRUGO | S_IWUGO);
1871         if (!inode)
1872                 goto err;
1873
1874         inode->i_ino = ++sel_last_ino;
1875         isec = (struct inode_security_struct *)inode->i_security;
1876         isec->sid = SECINITSID_DEVNULL;
1877         isec->sclass = SECCLASS_CHR_FILE;
1878         isec->initialized = 1;
1879
1880         init_special_inode(inode, S_IFCHR | S_IRUGO | S_IWUGO, MKDEV(MEM_MAJOR, 3));
1881         d_add(dentry, inode);
1882         selinux_null = dentry;
1883
1884         ret = -ENOMEM;
1885         dentry = d_alloc_name(sb->s_root, "avc");
1886         if (!dentry)
1887                 goto err;
1888
1889         ret = sel_make_dir(root_inode, dentry, &sel_last_ino);
1890         if (ret)
1891                 goto err;
1892
1893         ret = sel_make_avc_files(dentry);
1894         if (ret)
1895                 goto err;
1896
1897         ret = -ENOMEM;
1898         dentry = d_alloc_name(sb->s_root, "initial_contexts");
1899         if (!dentry)
1900                 goto err;
1901
1902         ret = sel_make_dir(root_inode, dentry, &sel_last_ino);
1903         if (ret)
1904                 goto err;
1905
1906         ret = sel_make_initcon_files(dentry);
1907         if (ret)
1908                 goto err;
1909
1910         ret = -ENOMEM;
1911         dentry = d_alloc_name(sb->s_root, "class");
1912         if (!dentry)
1913                 goto err;
1914
1915         ret = sel_make_dir(root_inode, dentry, &sel_last_ino);
1916         if (ret)
1917                 goto err;
1918
1919         class_dir = dentry;
1920
1921         ret = -ENOMEM;
1922         dentry = d_alloc_name(sb->s_root, "policy_capabilities");
1923         if (!dentry)
1924                 goto err;
1925
1926         ret = sel_make_dir(root_inode, dentry, &sel_last_ino);
1927         if (ret)
1928                 goto err;
1929
1930         policycap_dir = dentry;
1931
1932         return 0;
1933 err:
1934         printk(KERN_ERR "SELinux: %s:  failed while creating inodes\n",
1935                 __func__);
1936         return ret;
1937 }
1938
1939 static struct dentry *sel_mount(struct file_system_type *fs_type,
1940                       int flags, const char *dev_name, void *data)
1941 {
1942         return mount_single(fs_type, flags, data, sel_fill_super);
1943 }
1944
1945 static struct file_system_type sel_fs_type = {
1946         .name           = "selinuxfs",
1947         .mount          = sel_mount,
1948         .kill_sb        = kill_litter_super,
1949 };
1950
1951 struct vfsmount *selinuxfs_mount;
1952 static struct kobject *selinuxfs_kobj;
1953
1954 static int __init init_sel_fs(void)
1955 {
1956         int err;
1957
1958         if (!selinux_enabled)
1959                 return 0;
1960
1961         selinuxfs_kobj = kobject_create_and_add("selinux", fs_kobj);
1962         if (!selinuxfs_kobj)
1963                 return -ENOMEM;
1964
1965         err = register_filesystem(&sel_fs_type);
1966         if (err) {
1967                 kobject_put(selinuxfs_kobj);
1968                 return err;
1969         }
1970
1971         selinuxfs_mount = kern_mount(&sel_fs_type);
1972         if (IS_ERR(selinuxfs_mount)) {
1973                 printk(KERN_ERR "selinuxfs:  could not mount!\n");
1974                 err = PTR_ERR(selinuxfs_mount);
1975                 selinuxfs_mount = NULL;
1976         }
1977
1978         return err;
1979 }
1980
1981 __initcall(init_sel_fs);
1982
1983 #ifdef CONFIG_SECURITY_SELINUX_DISABLE
1984 void exit_sel_fs(void)
1985 {
1986         kobject_put(selinuxfs_kobj);
1987         kern_unmount(selinuxfs_mount);
1988         unregister_filesystem(&sel_fs_type);
1989 }
1990 #endif