Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris...
[sfrench/cifs-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@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         "redhat1",
49         "always_check_network"
50 };
51
52 unsigned int selinux_checkreqprot = CONFIG_SECURITY_SELINUX_CHECKREQPROT_VALUE;
53
54 static int __init checkreqprot_setup(char *str)
55 {
56         unsigned long checkreqprot;
57         if (!kstrtoul(str, 0, &checkreqprot))
58                 selinux_checkreqprot = checkreqprot ? 1 : 0;
59         return 1;
60 }
61 __setup("checkreqprot=", checkreqprot_setup);
62
63 static DEFINE_MUTEX(sel_mutex);
64
65 /* global data for booleans */
66 static struct dentry *bool_dir;
67 static int bool_num;
68 static char **bool_pending_names;
69 static int *bool_pending_values;
70
71 /* global data for classes */
72 static struct dentry *class_dir;
73 static unsigned long last_class_ino;
74
75 static char policy_opened;
76
77 /* global data for policy capabilities */
78 static struct dentry *policycap_dir;
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                         from_kuid(&init_user_ns, 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 = file_inode(filp)->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
282         length = -ENOMEM;
283         if (count >= PAGE_SIZE)
284                 goto out;
285
286         /* No partial writes. */
287         length = -EINVAL;
288         if (*ppos != 0)
289                 goto out;
290
291         length = -ENOMEM;
292         page = (char *)get_zeroed_page(GFP_KERNEL);
293         if (!page)
294                 goto out;
295
296         length = -EFAULT;
297         if (copy_from_user(page, buf, count))
298                 goto out;
299
300         length = -EINVAL;
301         if (sscanf(page, "%d", &new_value) != 1)
302                 goto out;
303
304         if (new_value) {
305                 length = selinux_disable();
306                 if (length)
307                         goto out;
308                 audit_log(current->audit_context, GFP_KERNEL, AUDIT_MAC_STATUS,
309                         "selinux=0 auid=%u ses=%u",
310                         from_kuid(&init_user_ns, audit_get_loginuid(current)),
311                         audit_get_sessionid(current));
312         }
313
314         length = count;
315 out:
316         free_page((unsigned long) page);
317         return length;
318 }
319 #else
320 #define sel_write_disable NULL
321 #endif
322
323 static const struct file_operations sel_disable_ops = {
324         .write          = sel_write_disable,
325         .llseek         = generic_file_llseek,
326 };
327
328 static ssize_t sel_read_policyvers(struct file *filp, char __user *buf,
329                                    size_t count, loff_t *ppos)
330 {
331         char tmpbuf[TMPBUFLEN];
332         ssize_t length;
333
334         length = scnprintf(tmpbuf, TMPBUFLEN, "%u", POLICYDB_VERSION_MAX);
335         return simple_read_from_buffer(buf, count, ppos, tmpbuf, length);
336 }
337
338 static const struct file_operations sel_policyvers_ops = {
339         .read           = sel_read_policyvers,
340         .llseek         = generic_file_llseek,
341 };
342
343 /* declaration for sel_write_load */
344 static int sel_make_bools(void);
345 static int sel_make_classes(void);
346 static int sel_make_policycap(void);
347
348 /* declaration for sel_make_class_dirs */
349 static struct dentry *sel_make_dir(struct dentry *dir, const char *name,
350                         unsigned long *ino);
351
352 static ssize_t sel_read_mls(struct file *filp, char __user *buf,
353                                 size_t count, loff_t *ppos)
354 {
355         char tmpbuf[TMPBUFLEN];
356         ssize_t length;
357
358         length = scnprintf(tmpbuf, TMPBUFLEN, "%d",
359                            security_mls_enabled());
360         return simple_read_from_buffer(buf, count, ppos, tmpbuf, length);
361 }
362
363 static const struct file_operations sel_mls_ops = {
364         .read           = sel_read_mls,
365         .llseek         = generic_file_llseek,
366 };
367
368 struct policy_load_memory {
369         size_t len;
370         void *data;
371 };
372
373 static int sel_open_policy(struct inode *inode, struct file *filp)
374 {
375         struct policy_load_memory *plm = NULL;
376         int rc;
377
378         BUG_ON(filp->private_data);
379
380         mutex_lock(&sel_mutex);
381
382         rc = task_has_security(current, SECURITY__READ_POLICY);
383         if (rc)
384                 goto err;
385
386         rc = -EBUSY;
387         if (policy_opened)
388                 goto err;
389
390         rc = -ENOMEM;
391         plm = kzalloc(sizeof(*plm), GFP_KERNEL);
392         if (!plm)
393                 goto err;
394
395         if (i_size_read(inode) != security_policydb_len()) {
396                 mutex_lock(&inode->i_mutex);
397                 i_size_write(inode, security_policydb_len());
398                 mutex_unlock(&inode->i_mutex);
399         }
400
401         rc = security_read_policy(&plm->data, &plm->len);
402         if (rc)
403                 goto err;
404
405         policy_opened = 1;
406
407         filp->private_data = plm;
408
409         mutex_unlock(&sel_mutex);
410
411         return 0;
412 err:
413         mutex_unlock(&sel_mutex);
414
415         if (plm)
416                 vfree(plm->data);
417         kfree(plm);
418         return rc;
419 }
420
421 static int sel_release_policy(struct inode *inode, struct file *filp)
422 {
423         struct policy_load_memory *plm = filp->private_data;
424
425         BUG_ON(!plm);
426
427         policy_opened = 0;
428
429         vfree(plm->data);
430         kfree(plm);
431
432         return 0;
433 }
434
435 static ssize_t sel_read_policy(struct file *filp, char __user *buf,
436                                size_t count, loff_t *ppos)
437 {
438         struct policy_load_memory *plm = filp->private_data;
439         int ret;
440
441         mutex_lock(&sel_mutex);
442
443         ret = task_has_security(current, SECURITY__READ_POLICY);
444         if (ret)
445                 goto out;
446
447         ret = simple_read_from_buffer(buf, count, ppos, plm->data, plm->len);
448 out:
449         mutex_unlock(&sel_mutex);
450         return ret;
451 }
452
453 static int sel_mmap_policy_fault(struct vm_area_struct *vma,
454                                  struct vm_fault *vmf)
455 {
456         struct policy_load_memory *plm = vma->vm_file->private_data;
457         unsigned long offset;
458         struct page *page;
459
460         if (vmf->flags & (FAULT_FLAG_MKWRITE | FAULT_FLAG_WRITE))
461                 return VM_FAULT_SIGBUS;
462
463         offset = vmf->pgoff << PAGE_SHIFT;
464         if (offset >= roundup(plm->len, PAGE_SIZE))
465                 return VM_FAULT_SIGBUS;
466
467         page = vmalloc_to_page(plm->data + offset);
468         get_page(page);
469
470         vmf->page = page;
471
472         return 0;
473 }
474
475 static struct vm_operations_struct sel_mmap_policy_ops = {
476         .fault = sel_mmap_policy_fault,
477         .page_mkwrite = sel_mmap_policy_fault,
478 };
479
480 static int sel_mmap_policy(struct file *filp, struct vm_area_struct *vma)
481 {
482         if (vma->vm_flags & VM_SHARED) {
483                 /* do not allow mprotect to make mapping writable */
484                 vma->vm_flags &= ~VM_MAYWRITE;
485
486                 if (vma->vm_flags & VM_WRITE)
487                         return -EACCES;
488         }
489
490         vma->vm_flags |= VM_DONTEXPAND | VM_DONTDUMP;
491         vma->vm_ops = &sel_mmap_policy_ops;
492
493         return 0;
494 }
495
496 static const struct file_operations sel_policy_ops = {
497         .open           = sel_open_policy,
498         .read           = sel_read_policy,
499         .mmap           = sel_mmap_policy,
500         .release        = sel_release_policy,
501         .llseek         = generic_file_llseek,
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                 from_kuid(&init_user_ns, 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, GFP_KERNEL);
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_inode(file)->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                                          GFP_KERNEL);
736         if (length)
737                 goto out;
738
739         length = security_context_to_sid(tcon, strlen(tcon) + 1, &tsid,
740                                          GFP_KERNEL);
741         if (length)
742                 goto out;
743
744         security_compute_av_user(ssid, tsid, tclass, &avd);
745
746         length = scnprintf(buf, SIMPLE_TRANSACTION_LIMIT,
747                           "%x %x %x %x %u %x",
748                           avd.allowed, 0xffffffff,
749                           avd.auditallow, avd.auditdeny,
750                           avd.seqno, avd.flags);
751 out:
752         kfree(tcon);
753         kfree(scon);
754         return length;
755 }
756
757 static ssize_t sel_write_create(struct file *file, char *buf, size_t size)
758 {
759         char *scon = NULL, *tcon = NULL;
760         char *namebuf = NULL, *objname = NULL;
761         u32 ssid, tsid, newsid;
762         u16 tclass;
763         ssize_t length;
764         char *newcon = NULL;
765         u32 len;
766         int nargs;
767
768         length = task_has_security(current, SECURITY__COMPUTE_CREATE);
769         if (length)
770                 goto out;
771
772         length = -ENOMEM;
773         scon = kzalloc(size + 1, GFP_KERNEL);
774         if (!scon)
775                 goto out;
776
777         length = -ENOMEM;
778         tcon = kzalloc(size + 1, GFP_KERNEL);
779         if (!tcon)
780                 goto out;
781
782         length = -ENOMEM;
783         namebuf = kzalloc(size + 1, GFP_KERNEL);
784         if (!namebuf)
785                 goto out;
786
787         length = -EINVAL;
788         nargs = sscanf(buf, "%s %s %hu %s", scon, tcon, &tclass, namebuf);
789         if (nargs < 3 || nargs > 4)
790                 goto out;
791         if (nargs == 4) {
792                 /*
793                  * If and when the name of new object to be queried contains
794                  * either whitespace or multibyte characters, they shall be
795                  * encoded based on the percentage-encoding rule.
796                  * If not encoded, the sscanf logic picks up only left-half
797                  * of the supplied name; splitted by a whitespace unexpectedly.
798                  */
799                 char   *r, *w;
800                 int     c1, c2;
801
802                 r = w = namebuf;
803                 do {
804                         c1 = *r++;
805                         if (c1 == '+')
806                                 c1 = ' ';
807                         else if (c1 == '%') {
808                                 c1 = hex_to_bin(*r++);
809                                 if (c1 < 0)
810                                         goto out;
811                                 c2 = hex_to_bin(*r++);
812                                 if (c2 < 0)
813                                         goto out;
814                                 c1 = (c1 << 4) | c2;
815                         }
816                         *w++ = c1;
817                 } while (c1 != '\0');
818
819                 objname = namebuf;
820         }
821
822         length = security_context_to_sid(scon, strlen(scon) + 1, &ssid,
823                                          GFP_KERNEL);
824         if (length)
825                 goto out;
826
827         length = security_context_to_sid(tcon, strlen(tcon) + 1, &tsid,
828                                          GFP_KERNEL);
829         if (length)
830                 goto out;
831
832         length = security_transition_sid_user(ssid, tsid, tclass,
833                                               objname, &newsid);
834         if (length)
835                 goto out;
836
837         length = security_sid_to_context(newsid, &newcon, &len);
838         if (length)
839                 goto out;
840
841         length = -ERANGE;
842         if (len > SIMPLE_TRANSACTION_LIMIT) {
843                 printk(KERN_ERR "SELinux: %s:  context size (%u) exceeds "
844                         "payload max\n", __func__, len);
845                 goto out;
846         }
847
848         memcpy(buf, newcon, len);
849         length = len;
850 out:
851         kfree(newcon);
852         kfree(namebuf);
853         kfree(tcon);
854         kfree(scon);
855         return length;
856 }
857
858 static ssize_t sel_write_relabel(struct file *file, char *buf, size_t size)
859 {
860         char *scon = NULL, *tcon = NULL;
861         u32 ssid, tsid, newsid;
862         u16 tclass;
863         ssize_t length;
864         char *newcon = NULL;
865         u32 len;
866
867         length = task_has_security(current, SECURITY__COMPUTE_RELABEL);
868         if (length)
869                 goto out;
870
871         length = -ENOMEM;
872         scon = kzalloc(size + 1, GFP_KERNEL);
873         if (!scon)
874                 goto out;
875
876         length = -ENOMEM;
877         tcon = kzalloc(size + 1, GFP_KERNEL);
878         if (!tcon)
879                 goto out;
880
881         length = -EINVAL;
882         if (sscanf(buf, "%s %s %hu", scon, tcon, &tclass) != 3)
883                 goto out;
884
885         length = security_context_to_sid(scon, strlen(scon) + 1, &ssid,
886                                          GFP_KERNEL);
887         if (length)
888                 goto out;
889
890         length = security_context_to_sid(tcon, strlen(tcon) + 1, &tsid,
891                                          GFP_KERNEL);
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, GFP_KERNEL);
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                                          GFP_KERNEL);
1005         if (length)
1006                 goto out;
1007
1008         length = security_context_to_sid(tcon, strlen(tcon) + 1, &tsid,
1009                                          GFP_KERNEL);
1010         if (length)
1011                 goto out;
1012
1013         length = security_member_sid(ssid, tsid, tclass, &newsid);
1014         if (length)
1015                 goto out;
1016
1017         length = security_sid_to_context(newsid, &newcon, &len);
1018         if (length)
1019                 goto out;
1020
1021         length = -ERANGE;
1022         if (len > SIMPLE_TRANSACTION_LIMIT) {
1023                 printk(KERN_ERR "SELinux: %s:  context size (%u) exceeds "
1024                         "payload max\n", __func__, len);
1025                 goto out;
1026         }
1027
1028         memcpy(buf, newcon, len);
1029         length = len;
1030 out:
1031         kfree(newcon);
1032         kfree(tcon);
1033         kfree(scon);
1034         return length;
1035 }
1036
1037 static struct inode *sel_make_inode(struct super_block *sb, int mode)
1038 {
1039         struct inode *ret = new_inode(sb);
1040
1041         if (ret) {
1042                 ret->i_mode = mode;
1043                 ret->i_atime = ret->i_mtime = ret->i_ctime = CURRENT_TIME;
1044         }
1045         return ret;
1046 }
1047
1048 static ssize_t sel_read_bool(struct file *filep, char __user *buf,
1049                              size_t count, loff_t *ppos)
1050 {
1051         char *page = NULL;
1052         ssize_t length;
1053         ssize_t ret;
1054         int cur_enforcing;
1055         unsigned index = file_inode(filep)->i_ino & SEL_INO_MASK;
1056         const char *name = filep->f_path.dentry->d_name.name;
1057
1058         mutex_lock(&sel_mutex);
1059
1060         ret = -EINVAL;
1061         if (index >= bool_num || strcmp(name, bool_pending_names[index]))
1062                 goto out;
1063
1064         ret = -ENOMEM;
1065         page = (char *)get_zeroed_page(GFP_KERNEL);
1066         if (!page)
1067                 goto out;
1068
1069         cur_enforcing = security_get_bool_value(index);
1070         if (cur_enforcing < 0) {
1071                 ret = cur_enforcing;
1072                 goto out;
1073         }
1074         length = scnprintf(page, PAGE_SIZE, "%d %d", cur_enforcing,
1075                           bool_pending_values[index]);
1076         ret = simple_read_from_buffer(buf, count, ppos, page, length);
1077 out:
1078         mutex_unlock(&sel_mutex);
1079         free_page((unsigned long)page);
1080         return ret;
1081 }
1082
1083 static ssize_t sel_write_bool(struct file *filep, const char __user *buf,
1084                               size_t count, loff_t *ppos)
1085 {
1086         char *page = NULL;
1087         ssize_t length;
1088         int new_value;
1089         unsigned index = file_inode(filep)->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_num = 0;
1245         bool_pending_names = NULL;
1246         bool_pending_values = NULL;
1247
1248         sel_remove_entries(dir);
1249
1250         ret = -ENOMEM;
1251         page = (char *)get_zeroed_page(GFP_KERNEL);
1252         if (!page)
1253                 goto out;
1254
1255         ret = security_get_bools(&num, &names, &values);
1256         if (ret)
1257                 goto out;
1258
1259         for (i = 0; i < num; i++) {
1260                 ret = -ENOMEM;
1261                 dentry = d_alloc_name(dir, names[i]);
1262                 if (!dentry)
1263                         goto out;
1264
1265                 ret = -ENOMEM;
1266                 inode = sel_make_inode(dir->d_sb, S_IFREG | S_IRUGO | S_IWUSR);
1267                 if (!inode)
1268                         goto out;
1269
1270                 ret = -ENAMETOOLONG;
1271                 len = snprintf(page, PAGE_SIZE, "/%s/%s", BOOL_DIR_NAME, names[i]);
1272                 if (len >= PAGE_SIZE)
1273                         goto out;
1274
1275                 isec = (struct inode_security_struct *)inode->i_security;
1276                 ret = security_genfs_sid("selinuxfs", page, SECCLASS_FILE, &sid);
1277                 if (ret)
1278                         goto out;
1279
1280                 isec->sid = sid;
1281                 isec->initialized = 1;
1282                 inode->i_fop = &sel_bool_ops;
1283                 inode->i_ino = i|SEL_BOOL_INO_OFFSET;
1284                 d_add(dentry, inode);
1285         }
1286         bool_num = num;
1287         bool_pending_names = names;
1288         bool_pending_values = values;
1289
1290         free_page((unsigned long)page);
1291         return 0;
1292 out:
1293         free_page((unsigned long)page);
1294
1295         if (names) {
1296                 for (i = 0; i < num; i++)
1297                         kfree(names[i]);
1298                 kfree(names);
1299         }
1300         kfree(values);
1301         sel_remove_entries(dir);
1302
1303         return ret;
1304 }
1305
1306 #define NULL_FILE_NAME "null"
1307
1308 struct path selinux_null;
1309
1310 static ssize_t sel_read_avc_cache_threshold(struct file *filp, char __user *buf,
1311                                             size_t count, loff_t *ppos)
1312 {
1313         char tmpbuf[TMPBUFLEN];
1314         ssize_t length;
1315
1316         length = scnprintf(tmpbuf, TMPBUFLEN, "%u", avc_cache_threshold);
1317         return simple_read_from_buffer(buf, count, ppos, tmpbuf, length);
1318 }
1319
1320 static ssize_t sel_write_avc_cache_threshold(struct file *file,
1321                                              const char __user *buf,
1322                                              size_t count, loff_t *ppos)
1323
1324 {
1325         char *page = NULL;
1326         ssize_t ret;
1327         int new_value;
1328
1329         ret = task_has_security(current, SECURITY__SETSECPARAM);
1330         if (ret)
1331                 goto out;
1332
1333         ret = -ENOMEM;
1334         if (count >= PAGE_SIZE)
1335                 goto out;
1336
1337         /* No partial writes. */
1338         ret = -EINVAL;
1339         if (*ppos != 0)
1340                 goto out;
1341
1342         ret = -ENOMEM;
1343         page = (char *)get_zeroed_page(GFP_KERNEL);
1344         if (!page)
1345                 goto out;
1346
1347         ret = -EFAULT;
1348         if (copy_from_user(page, buf, count))
1349                 goto out;
1350
1351         ret = -EINVAL;
1352         if (sscanf(page, "%u", &new_value) != 1)
1353                 goto out;
1354
1355         avc_cache_threshold = new_value;
1356
1357         ret = count;
1358 out:
1359         free_page((unsigned long)page);
1360         return ret;
1361 }
1362
1363 static ssize_t sel_read_avc_hash_stats(struct file *filp, char __user *buf,
1364                                        size_t count, loff_t *ppos)
1365 {
1366         char *page;
1367         ssize_t length;
1368
1369         page = (char *)__get_free_page(GFP_KERNEL);
1370         if (!page)
1371                 return -ENOMEM;
1372
1373         length = avc_get_hash_stats(page);
1374         if (length >= 0)
1375                 length = simple_read_from_buffer(buf, count, ppos, page, length);
1376         free_page((unsigned long)page);
1377
1378         return length;
1379 }
1380
1381 static const struct file_operations sel_avc_cache_threshold_ops = {
1382         .read           = sel_read_avc_cache_threshold,
1383         .write          = sel_write_avc_cache_threshold,
1384         .llseek         = generic_file_llseek,
1385 };
1386
1387 static const struct file_operations sel_avc_hash_stats_ops = {
1388         .read           = sel_read_avc_hash_stats,
1389         .llseek         = generic_file_llseek,
1390 };
1391
1392 #ifdef CONFIG_SECURITY_SELINUX_AVC_STATS
1393 static struct avc_cache_stats *sel_avc_get_stat_idx(loff_t *idx)
1394 {
1395         int cpu;
1396
1397         for (cpu = *idx; cpu < nr_cpu_ids; ++cpu) {
1398                 if (!cpu_possible(cpu))
1399                         continue;
1400                 *idx = cpu + 1;
1401                 return &per_cpu(avc_cache_stats, cpu);
1402         }
1403         return NULL;
1404 }
1405
1406 static void *sel_avc_stats_seq_start(struct seq_file *seq, loff_t *pos)
1407 {
1408         loff_t n = *pos - 1;
1409
1410         if (*pos == 0)
1411                 return SEQ_START_TOKEN;
1412
1413         return sel_avc_get_stat_idx(&n);
1414 }
1415
1416 static void *sel_avc_stats_seq_next(struct seq_file *seq, void *v, loff_t *pos)
1417 {
1418         return sel_avc_get_stat_idx(pos);
1419 }
1420
1421 static int sel_avc_stats_seq_show(struct seq_file *seq, void *v)
1422 {
1423         struct avc_cache_stats *st = v;
1424
1425         if (v == SEQ_START_TOKEN)
1426                 seq_printf(seq, "lookups hits misses allocations reclaims "
1427                            "frees\n");
1428         else {
1429                 unsigned int lookups = st->lookups;
1430                 unsigned int misses = st->misses;
1431                 unsigned int hits = lookups - misses;
1432                 seq_printf(seq, "%u %u %u %u %u %u\n", lookups,
1433                            hits, misses, st->allocations,
1434                            st->reclaims, st->frees);
1435         }
1436         return 0;
1437 }
1438
1439 static void sel_avc_stats_seq_stop(struct seq_file *seq, void *v)
1440 { }
1441
1442 static const struct seq_operations sel_avc_cache_stats_seq_ops = {
1443         .start          = sel_avc_stats_seq_start,
1444         .next           = sel_avc_stats_seq_next,
1445         .show           = sel_avc_stats_seq_show,
1446         .stop           = sel_avc_stats_seq_stop,
1447 };
1448
1449 static int sel_open_avc_cache_stats(struct inode *inode, struct file *file)
1450 {
1451         return seq_open(file, &sel_avc_cache_stats_seq_ops);
1452 }
1453
1454 static const struct file_operations sel_avc_cache_stats_ops = {
1455         .open           = sel_open_avc_cache_stats,
1456         .read           = seq_read,
1457         .llseek         = seq_lseek,
1458         .release        = seq_release,
1459 };
1460 #endif
1461
1462 static int sel_make_avc_files(struct dentry *dir)
1463 {
1464         int i;
1465         static struct tree_descr files[] = {
1466                 { "cache_threshold",
1467                   &sel_avc_cache_threshold_ops, S_IRUGO|S_IWUSR },
1468                 { "hash_stats", &sel_avc_hash_stats_ops, S_IRUGO },
1469 #ifdef CONFIG_SECURITY_SELINUX_AVC_STATS
1470                 { "cache_stats", &sel_avc_cache_stats_ops, S_IRUGO },
1471 #endif
1472         };
1473
1474         for (i = 0; i < ARRAY_SIZE(files); i++) {
1475                 struct inode *inode;
1476                 struct dentry *dentry;
1477
1478                 dentry = d_alloc_name(dir, files[i].name);
1479                 if (!dentry)
1480                         return -ENOMEM;
1481
1482                 inode = sel_make_inode(dir->d_sb, S_IFREG|files[i].mode);
1483                 if (!inode)
1484                         return -ENOMEM;
1485
1486                 inode->i_fop = files[i].ops;
1487                 inode->i_ino = ++sel_last_ino;
1488                 d_add(dentry, inode);
1489         }
1490
1491         return 0;
1492 }
1493
1494 static ssize_t sel_read_initcon(struct file *file, char __user *buf,
1495                                 size_t count, loff_t *ppos)
1496 {
1497         char *con;
1498         u32 sid, len;
1499         ssize_t ret;
1500
1501         sid = file_inode(file)->i_ino&SEL_INO_MASK;
1502         ret = security_sid_to_context(sid, &con, &len);
1503         if (ret)
1504                 return ret;
1505
1506         ret = simple_read_from_buffer(buf, count, ppos, con, len);
1507         kfree(con);
1508         return ret;
1509 }
1510
1511 static const struct file_operations sel_initcon_ops = {
1512         .read           = sel_read_initcon,
1513         .llseek         = generic_file_llseek,
1514 };
1515
1516 static int sel_make_initcon_files(struct dentry *dir)
1517 {
1518         int i;
1519
1520         for (i = 1; i <= SECINITSID_NUM; i++) {
1521                 struct inode *inode;
1522                 struct dentry *dentry;
1523                 dentry = d_alloc_name(dir, security_get_initial_sid_context(i));
1524                 if (!dentry)
1525                         return -ENOMEM;
1526
1527                 inode = sel_make_inode(dir->d_sb, S_IFREG|S_IRUGO);
1528                 if (!inode)
1529                         return -ENOMEM;
1530
1531                 inode->i_fop = &sel_initcon_ops;
1532                 inode->i_ino = i|SEL_INITCON_INO_OFFSET;
1533                 d_add(dentry, inode);
1534         }
1535
1536         return 0;
1537 }
1538
1539 static inline unsigned long sel_class_to_ino(u16 class)
1540 {
1541         return (class * (SEL_VEC_MAX + 1)) | SEL_CLASS_INO_OFFSET;
1542 }
1543
1544 static inline u16 sel_ino_to_class(unsigned long ino)
1545 {
1546         return (ino & SEL_INO_MASK) / (SEL_VEC_MAX + 1);
1547 }
1548
1549 static inline unsigned long sel_perm_to_ino(u16 class, u32 perm)
1550 {
1551         return (class * (SEL_VEC_MAX + 1) + perm) | SEL_CLASS_INO_OFFSET;
1552 }
1553
1554 static inline u32 sel_ino_to_perm(unsigned long ino)
1555 {
1556         return (ino & SEL_INO_MASK) % (SEL_VEC_MAX + 1);
1557 }
1558
1559 static ssize_t sel_read_class(struct file *file, char __user *buf,
1560                                 size_t count, loff_t *ppos)
1561 {
1562         unsigned long ino = file_inode(file)->i_ino;
1563         char res[TMPBUFLEN];
1564         ssize_t len = snprintf(res, sizeof(res), "%d", sel_ino_to_class(ino));
1565         return simple_read_from_buffer(buf, count, ppos, res, len);
1566 }
1567
1568 static const struct file_operations sel_class_ops = {
1569         .read           = sel_read_class,
1570         .llseek         = generic_file_llseek,
1571 };
1572
1573 static ssize_t sel_read_perm(struct file *file, char __user *buf,
1574                                 size_t count, loff_t *ppos)
1575 {
1576         unsigned long ino = file_inode(file)->i_ino;
1577         char res[TMPBUFLEN];
1578         ssize_t len = snprintf(res, sizeof(res), "%d", sel_ino_to_perm(ino));
1579         return simple_read_from_buffer(buf, count, ppos, res, len);
1580 }
1581
1582 static const struct file_operations sel_perm_ops = {
1583         .read           = sel_read_perm,
1584         .llseek         = generic_file_llseek,
1585 };
1586
1587 static ssize_t sel_read_policycap(struct file *file, char __user *buf,
1588                                   size_t count, loff_t *ppos)
1589 {
1590         int value;
1591         char tmpbuf[TMPBUFLEN];
1592         ssize_t length;
1593         unsigned long i_ino = file_inode(file)->i_ino;
1594
1595         value = security_policycap_supported(i_ino & SEL_INO_MASK);
1596         length = scnprintf(tmpbuf, TMPBUFLEN, "%d", value);
1597
1598         return simple_read_from_buffer(buf, count, ppos, tmpbuf, length);
1599 }
1600
1601 static const struct file_operations sel_policycap_ops = {
1602         .read           = sel_read_policycap,
1603         .llseek         = generic_file_llseek,
1604 };
1605
1606 static int sel_make_perm_files(char *objclass, int classvalue,
1607                                 struct dentry *dir)
1608 {
1609         int i, rc, nperms;
1610         char **perms;
1611
1612         rc = security_get_permissions(objclass, &perms, &nperms);
1613         if (rc)
1614                 return rc;
1615
1616         for (i = 0; i < nperms; i++) {
1617                 struct inode *inode;
1618                 struct dentry *dentry;
1619
1620                 rc = -ENOMEM;
1621                 dentry = d_alloc_name(dir, perms[i]);
1622                 if (!dentry)
1623                         goto out;
1624
1625                 rc = -ENOMEM;
1626                 inode = sel_make_inode(dir->d_sb, S_IFREG|S_IRUGO);
1627                 if (!inode)
1628                         goto out;
1629
1630                 inode->i_fop = &sel_perm_ops;
1631                 /* i+1 since perm values are 1-indexed */
1632                 inode->i_ino = sel_perm_to_ino(classvalue, i + 1);
1633                 d_add(dentry, inode);
1634         }
1635         rc = 0;
1636 out:
1637         for (i = 0; i < nperms; i++)
1638                 kfree(perms[i]);
1639         kfree(perms);
1640         return rc;
1641 }
1642
1643 static int sel_make_class_dir_entries(char *classname, int index,
1644                                         struct dentry *dir)
1645 {
1646         struct dentry *dentry = NULL;
1647         struct inode *inode = NULL;
1648         int rc;
1649
1650         dentry = d_alloc_name(dir, "index");
1651         if (!dentry)
1652                 return -ENOMEM;
1653
1654         inode = sel_make_inode(dir->d_sb, S_IFREG|S_IRUGO);
1655         if (!inode)
1656                 return -ENOMEM;
1657
1658         inode->i_fop = &sel_class_ops;
1659         inode->i_ino = sel_class_to_ino(index);
1660         d_add(dentry, inode);
1661
1662         dentry = sel_make_dir(dir, "perms", &last_class_ino);
1663         if (IS_ERR(dentry))
1664                 return PTR_ERR(dentry);
1665
1666         rc = sel_make_perm_files(classname, index, dentry);
1667
1668         return rc;
1669 }
1670
1671 static void sel_remove_classes(void)
1672 {
1673         struct list_head *class_node;
1674
1675         list_for_each(class_node, &class_dir->d_subdirs) {
1676                 struct dentry *class_subdir = list_entry(class_node,
1677                                         struct dentry, d_u.d_child);
1678                 struct list_head *class_subdir_node;
1679
1680                 list_for_each(class_subdir_node, &class_subdir->d_subdirs) {
1681                         struct dentry *d = list_entry(class_subdir_node,
1682                                                 struct dentry, d_u.d_child);
1683
1684                         if (d->d_inode)
1685                                 if (d->d_inode->i_mode & S_IFDIR)
1686                                         sel_remove_entries(d);
1687                 }
1688
1689                 sel_remove_entries(class_subdir);
1690         }
1691
1692         sel_remove_entries(class_dir);
1693 }
1694
1695 static int sel_make_classes(void)
1696 {
1697         int rc, nclasses, i;
1698         char **classes;
1699
1700         /* delete any existing entries */
1701         sel_remove_classes();
1702
1703         rc = security_get_classes(&classes, &nclasses);
1704         if (rc)
1705                 return rc;
1706
1707         /* +2 since classes are 1-indexed */
1708         last_class_ino = sel_class_to_ino(nclasses + 2);
1709
1710         for (i = 0; i < nclasses; i++) {
1711                 struct dentry *class_name_dir;
1712
1713                 class_name_dir = sel_make_dir(class_dir, classes[i],
1714                                 &last_class_ino);
1715                 if (IS_ERR(class_name_dir)) {
1716                         rc = PTR_ERR(class_name_dir);
1717                         goto out;
1718                 }
1719
1720                 /* i+1 since class values are 1-indexed */
1721                 rc = sel_make_class_dir_entries(classes[i], i + 1,
1722                                 class_name_dir);
1723                 if (rc)
1724                         goto out;
1725         }
1726         rc = 0;
1727 out:
1728         for (i = 0; i < nclasses; i++)
1729                 kfree(classes[i]);
1730         kfree(classes);
1731         return rc;
1732 }
1733
1734 static int sel_make_policycap(void)
1735 {
1736         unsigned int iter;
1737         struct dentry *dentry = NULL;
1738         struct inode *inode = NULL;
1739
1740         sel_remove_entries(policycap_dir);
1741
1742         for (iter = 0; iter <= POLICYDB_CAPABILITY_MAX; iter++) {
1743                 if (iter < ARRAY_SIZE(policycap_names))
1744                         dentry = d_alloc_name(policycap_dir,
1745                                               policycap_names[iter]);
1746                 else
1747                         dentry = d_alloc_name(policycap_dir, "unknown");
1748
1749                 if (dentry == NULL)
1750                         return -ENOMEM;
1751
1752                 inode = sel_make_inode(policycap_dir->d_sb, S_IFREG | S_IRUGO);
1753                 if (inode == NULL)
1754                         return -ENOMEM;
1755
1756                 inode->i_fop = &sel_policycap_ops;
1757                 inode->i_ino = iter | SEL_POLICYCAP_INO_OFFSET;
1758                 d_add(dentry, inode);
1759         }
1760
1761         return 0;
1762 }
1763
1764 static struct dentry *sel_make_dir(struct dentry *dir, const char *name,
1765                         unsigned long *ino)
1766 {
1767         struct dentry *dentry = d_alloc_name(dir, name);
1768         struct inode *inode;
1769
1770         if (!dentry)
1771                 return ERR_PTR(-ENOMEM);
1772
1773         inode = sel_make_inode(dir->d_sb, S_IFDIR | S_IRUGO | S_IXUGO);
1774         if (!inode) {
1775                 dput(dentry);
1776                 return ERR_PTR(-ENOMEM);
1777         }
1778
1779         inode->i_op = &simple_dir_inode_operations;
1780         inode->i_fop = &simple_dir_operations;
1781         inode->i_ino = ++(*ino);
1782         /* directory inodes start off with i_nlink == 2 (for "." entry) */
1783         inc_nlink(inode);
1784         d_add(dentry, inode);
1785         /* bump link count on parent directory, too */
1786         inc_nlink(dir->d_inode);
1787
1788         return dentry;
1789 }
1790
1791 static int sel_fill_super(struct super_block *sb, void *data, int silent)
1792 {
1793         int ret;
1794         struct dentry *dentry;
1795         struct inode *inode;
1796         struct inode_security_struct *isec;
1797
1798         static struct tree_descr selinux_files[] = {
1799                 [SEL_LOAD] = {"load", &sel_load_ops, S_IRUSR|S_IWUSR},
1800                 [SEL_ENFORCE] = {"enforce", &sel_enforce_ops, S_IRUGO|S_IWUSR},
1801                 [SEL_CONTEXT] = {"context", &transaction_ops, S_IRUGO|S_IWUGO},
1802                 [SEL_ACCESS] = {"access", &transaction_ops, S_IRUGO|S_IWUGO},
1803                 [SEL_CREATE] = {"create", &transaction_ops, S_IRUGO|S_IWUGO},
1804                 [SEL_RELABEL] = {"relabel", &transaction_ops, S_IRUGO|S_IWUGO},
1805                 [SEL_USER] = {"user", &transaction_ops, S_IRUGO|S_IWUGO},
1806                 [SEL_POLICYVERS] = {"policyvers", &sel_policyvers_ops, S_IRUGO},
1807                 [SEL_COMMIT_BOOLS] = {"commit_pending_bools", &sel_commit_bools_ops, S_IWUSR},
1808                 [SEL_MLS] = {"mls", &sel_mls_ops, S_IRUGO},
1809                 [SEL_DISABLE] = {"disable", &sel_disable_ops, S_IWUSR},
1810                 [SEL_MEMBER] = {"member", &transaction_ops, S_IRUGO|S_IWUGO},
1811                 [SEL_CHECKREQPROT] = {"checkreqprot", &sel_checkreqprot_ops, S_IRUGO|S_IWUSR},
1812                 [SEL_REJECT_UNKNOWN] = {"reject_unknown", &sel_handle_unknown_ops, S_IRUGO},
1813                 [SEL_DENY_UNKNOWN] = {"deny_unknown", &sel_handle_unknown_ops, S_IRUGO},
1814                 [SEL_STATUS] = {"status", &sel_handle_status_ops, S_IRUGO},
1815                 [SEL_POLICY] = {"policy", &sel_policy_ops, S_IRUGO},
1816                 /* last one */ {""}
1817         };
1818         ret = simple_fill_super(sb, SELINUX_MAGIC, selinux_files);
1819         if (ret)
1820                 goto err;
1821
1822         bool_dir = sel_make_dir(sb->s_root, BOOL_DIR_NAME, &sel_last_ino);
1823         if (IS_ERR(bool_dir)) {
1824                 ret = PTR_ERR(bool_dir);
1825                 bool_dir = NULL;
1826                 goto err;
1827         }
1828
1829         ret = -ENOMEM;
1830         dentry = d_alloc_name(sb->s_root, NULL_FILE_NAME);
1831         if (!dentry)
1832                 goto err;
1833
1834         ret = -ENOMEM;
1835         inode = sel_make_inode(sb, S_IFCHR | S_IRUGO | S_IWUGO);
1836         if (!inode)
1837                 goto err;
1838
1839         inode->i_ino = ++sel_last_ino;
1840         isec = (struct inode_security_struct *)inode->i_security;
1841         isec->sid = SECINITSID_DEVNULL;
1842         isec->sclass = SECCLASS_CHR_FILE;
1843         isec->initialized = 1;
1844
1845         init_special_inode(inode, S_IFCHR | S_IRUGO | S_IWUGO, MKDEV(MEM_MAJOR, 3));
1846         d_add(dentry, inode);
1847         selinux_null.dentry = dentry;
1848
1849         dentry = sel_make_dir(sb->s_root, "avc", &sel_last_ino);
1850         if (IS_ERR(dentry)) {
1851                 ret = PTR_ERR(dentry);
1852                 goto err;
1853         }
1854
1855         ret = sel_make_avc_files(dentry);
1856         if (ret)
1857                 goto err;
1858
1859         dentry = sel_make_dir(sb->s_root, "initial_contexts", &sel_last_ino);
1860         if (IS_ERR(dentry)) {
1861                 ret = PTR_ERR(dentry);
1862                 goto err;
1863         }
1864
1865         ret = sel_make_initcon_files(dentry);
1866         if (ret)
1867                 goto err;
1868
1869         class_dir = sel_make_dir(sb->s_root, "class", &sel_last_ino);
1870         if (IS_ERR(class_dir)) {
1871                 ret = PTR_ERR(class_dir);
1872                 class_dir = NULL;
1873                 goto err;
1874         }
1875
1876         policycap_dir = sel_make_dir(sb->s_root, "policy_capabilities", &sel_last_ino);
1877         if (IS_ERR(policycap_dir)) {
1878                 ret = PTR_ERR(policycap_dir);
1879                 policycap_dir = NULL;
1880                 goto err;
1881         }
1882         return 0;
1883 err:
1884         printk(KERN_ERR "SELinux: %s:  failed while creating inodes\n",
1885                 __func__);
1886         return ret;
1887 }
1888
1889 static struct dentry *sel_mount(struct file_system_type *fs_type,
1890                       int flags, const char *dev_name, void *data)
1891 {
1892         return mount_single(fs_type, flags, data, sel_fill_super);
1893 }
1894
1895 static struct file_system_type sel_fs_type = {
1896         .name           = "selinuxfs",
1897         .mount          = sel_mount,
1898         .kill_sb        = kill_litter_super,
1899 };
1900
1901 struct vfsmount *selinuxfs_mount;
1902 static struct kobject *selinuxfs_kobj;
1903
1904 static int __init init_sel_fs(void)
1905 {
1906         int err;
1907
1908         if (!selinux_enabled)
1909                 return 0;
1910
1911         selinuxfs_kobj = kobject_create_and_add("selinux", fs_kobj);
1912         if (!selinuxfs_kobj)
1913                 return -ENOMEM;
1914
1915         err = register_filesystem(&sel_fs_type);
1916         if (err) {
1917                 kobject_put(selinuxfs_kobj);
1918                 return err;
1919         }
1920
1921         selinux_null.mnt = selinuxfs_mount = kern_mount(&sel_fs_type);
1922         if (IS_ERR(selinuxfs_mount)) {
1923                 printk(KERN_ERR "selinuxfs:  could not mount!\n");
1924                 err = PTR_ERR(selinuxfs_mount);
1925                 selinuxfs_mount = NULL;
1926         }
1927
1928         return err;
1929 }
1930
1931 __initcall(init_sel_fs);
1932
1933 #ifdef CONFIG_SECURITY_SELINUX_DISABLE
1934 void exit_sel_fs(void)
1935 {
1936         kobject_put(selinuxfs_kobj);
1937         kern_unmount(selinuxfs_mount);
1938         unregister_filesystem(&sel_fs_type);
1939 }
1940 #endif