[PATCH] SELinux: remove unecessary size_t checks in selinuxfs
[linux-2.6] / security / selinux / selinuxfs.c
1 /* Updated: Karl MacMillan <kmacmillan@tresys.com>
2  *
3  *      Added conditional policy language extensions
4  *
5  * Copyright (C) 2003 - 2004 Tresys Technology, LLC
6  * Copyright (C) 2004 Red Hat, Inc., James Morris <jmorris@redhat.com>
7  *      This program is free software; you can redistribute it and/or modify
8  *      it under the terms of the GNU General Public License as published by
9  *      the Free Software Foundation, version 2.
10  */
11
12 #include <linux/config.h>
13 #include <linux/kernel.h>
14 #include <linux/pagemap.h>
15 #include <linux/slab.h>
16 #include <linux/vmalloc.h>
17 #include <linux/fs.h>
18 #include <linux/init.h>
19 #include <linux/string.h>
20 #include <linux/security.h>
21 #include <linux/major.h>
22 #include <linux/seq_file.h>
23 #include <linux/percpu.h>
24 #include <asm/uaccess.h>
25 #include <asm/semaphore.h>
26
27 /* selinuxfs pseudo filesystem for exporting the security policy API.
28    Based on the proc code and the fs/nfsd/nfsctl.c code. */
29
30 #include "flask.h"
31 #include "avc.h"
32 #include "avc_ss.h"
33 #include "security.h"
34 #include "objsec.h"
35 #include "conditional.h"
36
37 unsigned int selinux_checkreqprot = CONFIG_SECURITY_SELINUX_CHECKREQPROT_VALUE;
38
39 static int __init checkreqprot_setup(char *str)
40 {
41         selinux_checkreqprot = simple_strtoul(str,NULL,0) ? 1 : 0;
42         return 1;
43 }
44 __setup("checkreqprot=", checkreqprot_setup);
45
46
47 static DECLARE_MUTEX(sel_sem);
48
49 /* global data for booleans */
50 static struct dentry *bool_dir = NULL;
51 static int bool_num = 0;
52 static int *bool_pending_values = NULL;
53
54 extern void selnl_notify_setenforce(int val);
55
56 /* Check whether a task is allowed to use a security operation. */
57 static int task_has_security(struct task_struct *tsk,
58                              u32 perms)
59 {
60         struct task_security_struct *tsec;
61
62         tsec = tsk->security;
63         if (!tsec)
64                 return -EACCES;
65
66         return avc_has_perm(tsec->sid, SECINITSID_SECURITY,
67                             SECCLASS_SECURITY, perms, NULL);
68 }
69
70 enum sel_inos {
71         SEL_ROOT_INO = 2,
72         SEL_LOAD,       /* load policy */
73         SEL_ENFORCE,    /* get or set enforcing status */
74         SEL_CONTEXT,    /* validate context */
75         SEL_ACCESS,     /* compute access decision */
76         SEL_CREATE,     /* compute create labeling decision */
77         SEL_RELABEL,    /* compute relabeling decision */
78         SEL_USER,       /* compute reachable user contexts */
79         SEL_POLICYVERS, /* return policy version for this kernel */
80         SEL_COMMIT_BOOLS, /* commit new boolean values */
81         SEL_MLS,        /* return if MLS policy is enabled */
82         SEL_DISABLE,    /* disable SELinux until next reboot */
83         SEL_AVC,        /* AVC management directory */
84         SEL_MEMBER,     /* compute polyinstantiation membership decision */
85         SEL_CHECKREQPROT, /* check requested protection, not kernel-applied one */
86 };
87
88 #define TMPBUFLEN       12
89 static ssize_t sel_read_enforce(struct file *filp, char __user *buf,
90                                 size_t count, loff_t *ppos)
91 {
92         char tmpbuf[TMPBUFLEN];
93         ssize_t length;
94
95         length = scnprintf(tmpbuf, TMPBUFLEN, "%d", selinux_enforcing);
96         return simple_read_from_buffer(buf, count, ppos, tmpbuf, length);
97 }
98
99 #ifdef CONFIG_SECURITY_SELINUX_DEVELOP
100 static ssize_t sel_write_enforce(struct file * file, const char __user * buf,
101                                  size_t count, loff_t *ppos)
102
103 {
104         char *page;
105         ssize_t length;
106         int new_value;
107
108         if (count >= PAGE_SIZE)
109                 return -ENOMEM;
110         if (*ppos != 0) {
111                 /* No partial writes. */
112                 return -EINVAL;
113         }
114         page = (char*)get_zeroed_page(GFP_KERNEL);
115         if (!page)
116                 return -ENOMEM;
117         length = -EFAULT;
118         if (copy_from_user(page, buf, count))
119                 goto out;
120
121         length = -EINVAL;
122         if (sscanf(page, "%d", &new_value) != 1)
123                 goto out;
124
125         if (new_value != selinux_enforcing) {
126                 length = task_has_security(current, SECURITY__SETENFORCE);
127                 if (length)
128                         goto out;
129                 selinux_enforcing = new_value;
130                 if (selinux_enforcing)
131                         avc_ss_reset(0);
132                 selnl_notify_setenforce(selinux_enforcing);
133         }
134         length = count;
135 out:
136         free_page((unsigned long) page);
137         return length;
138 }
139 #else
140 #define sel_write_enforce NULL
141 #endif
142
143 static struct file_operations sel_enforce_ops = {
144         .read           = sel_read_enforce,
145         .write          = sel_write_enforce,
146 };
147
148 #ifdef CONFIG_SECURITY_SELINUX_DISABLE
149 static ssize_t sel_write_disable(struct file * file, const char __user * buf,
150                                  size_t count, loff_t *ppos)
151
152 {
153         char *page;
154         ssize_t length;
155         int new_value;
156         extern int selinux_disable(void);
157
158         if (count >= PAGE_SIZE)
159                 return -ENOMEM;
160         if (*ppos != 0) {
161                 /* No partial writes. */
162                 return -EINVAL;
163         }
164         page = (char*)get_zeroed_page(GFP_KERNEL);
165         if (!page)
166                 return -ENOMEM;
167         length = -EFAULT;
168         if (copy_from_user(page, buf, count))
169                 goto out;
170
171         length = -EINVAL;
172         if (sscanf(page, "%d", &new_value) != 1)
173                 goto out;
174
175         if (new_value) {
176                 length = selinux_disable();
177                 if (length < 0)
178                         goto out;
179         }
180
181         length = count;
182 out:
183         free_page((unsigned long) page);
184         return length;
185 }
186 #else
187 #define sel_write_disable NULL
188 #endif
189
190 static struct file_operations sel_disable_ops = {
191         .write          = sel_write_disable,
192 };
193
194 static ssize_t sel_read_policyvers(struct file *filp, char __user *buf,
195                                    size_t count, loff_t *ppos)
196 {
197         char tmpbuf[TMPBUFLEN];
198         ssize_t length;
199
200         length = scnprintf(tmpbuf, TMPBUFLEN, "%u", POLICYDB_VERSION_MAX);
201         return simple_read_from_buffer(buf, count, ppos, tmpbuf, length);
202 }
203
204 static struct file_operations sel_policyvers_ops = {
205         .read           = sel_read_policyvers,
206 };
207
208 /* declaration for sel_write_load */
209 static int sel_make_bools(void);
210
211 static ssize_t sel_read_mls(struct file *filp, char __user *buf,
212                                 size_t count, loff_t *ppos)
213 {
214         char tmpbuf[TMPBUFLEN];
215         ssize_t length;
216
217         length = scnprintf(tmpbuf, TMPBUFLEN, "%d", selinux_mls_enabled);
218         return simple_read_from_buffer(buf, count, ppos, tmpbuf, length);
219 }
220
221 static struct file_operations sel_mls_ops = {
222         .read           = sel_read_mls,
223 };
224
225 static ssize_t sel_write_load(struct file * file, const char __user * buf,
226                               size_t count, loff_t *ppos)
227
228 {
229         int ret;
230         ssize_t length;
231         void *data = NULL;
232
233         down(&sel_sem);
234
235         length = task_has_security(current, SECURITY__LOAD_POLICY);
236         if (length)
237                 goto out;
238
239         if (*ppos != 0) {
240                 /* No partial writes. */
241                 length = -EINVAL;
242                 goto out;
243         }
244
245         if ((count > 64 * 1024 * 1024)
246             || (data = vmalloc(count)) == NULL) {
247                 length = -ENOMEM;
248                 goto out;
249         }
250
251         length = -EFAULT;
252         if (copy_from_user(data, buf, count) != 0)
253                 goto out;
254
255         length = security_load_policy(data, count);
256         if (length)
257                 goto out;
258
259         ret = sel_make_bools();
260         if (ret)
261                 length = ret;
262         else
263                 length = count;
264 out:
265         up(&sel_sem);
266         vfree(data);
267         return length;
268 }
269
270 static struct file_operations sel_load_ops = {
271         .write          = sel_write_load,
272 };
273
274
275 static ssize_t sel_write_context(struct file * file, const char __user * buf,
276                                  size_t count, loff_t *ppos)
277
278 {
279         char *page;
280         u32 sid;
281         ssize_t length;
282
283         length = task_has_security(current, SECURITY__CHECK_CONTEXT);
284         if (length)
285                 return length;
286
287         if (count >= PAGE_SIZE)
288                 return -ENOMEM;
289         if (*ppos != 0) {
290                 /* No partial writes. */
291                 return -EINVAL;
292         }
293         page = (char*)get_zeroed_page(GFP_KERNEL);
294         if (!page)
295                 return -ENOMEM;
296         length = -EFAULT;
297         if (copy_from_user(page, buf, count))
298                 goto out;
299
300         length = security_context_to_sid(page, count, &sid);
301         if (length < 0)
302                 goto out;
303
304         length = count;
305 out:
306         free_page((unsigned long) page);
307         return length;
308 }
309
310 static struct file_operations sel_context_ops = {
311         .write          = sel_write_context,
312 };
313
314 static ssize_t sel_read_checkreqprot(struct file *filp, char __user *buf,
315                                      size_t count, loff_t *ppos)
316 {
317         char tmpbuf[TMPBUFLEN];
318         ssize_t length;
319
320         length = scnprintf(tmpbuf, TMPBUFLEN, "%u", selinux_checkreqprot);
321         return simple_read_from_buffer(buf, count, ppos, tmpbuf, length);
322 }
323
324 static ssize_t sel_write_checkreqprot(struct file * file, const char __user * buf,
325                                       size_t count, loff_t *ppos)
326 {
327         char *page;
328         ssize_t length;
329         unsigned int new_value;
330
331         length = task_has_security(current, SECURITY__SETCHECKREQPROT);
332         if (length)
333                 return length;
334
335         if (count >= PAGE_SIZE)
336                 return -ENOMEM;
337         if (*ppos != 0) {
338                 /* No partial writes. */
339                 return -EINVAL;
340         }
341         page = (char*)get_zeroed_page(GFP_KERNEL);
342         if (!page)
343                 return -ENOMEM;
344         length = -EFAULT;
345         if (copy_from_user(page, buf, count))
346                 goto out;
347
348         length = -EINVAL;
349         if (sscanf(page, "%u", &new_value) != 1)
350                 goto out;
351
352         selinux_checkreqprot = new_value ? 1 : 0;
353         length = count;
354 out:
355         free_page((unsigned long) page);
356         return length;
357 }
358 static struct file_operations sel_checkreqprot_ops = {
359         .read           = sel_read_checkreqprot,
360         .write          = sel_write_checkreqprot,
361 };
362
363 /*
364  * Remaining nodes use transaction based IO methods like nfsd/nfsctl.c
365  */
366 static ssize_t sel_write_access(struct file * file, char *buf, size_t size);
367 static ssize_t sel_write_create(struct file * file, char *buf, size_t size);
368 static ssize_t sel_write_relabel(struct file * file, char *buf, size_t size);
369 static ssize_t sel_write_user(struct file * file, char *buf, size_t size);
370 static ssize_t sel_write_member(struct file * file, char *buf, size_t size);
371
372 static ssize_t (*write_op[])(struct file *, char *, size_t) = {
373         [SEL_ACCESS] = sel_write_access,
374         [SEL_CREATE] = sel_write_create,
375         [SEL_RELABEL] = sel_write_relabel,
376         [SEL_USER] = sel_write_user,
377         [SEL_MEMBER] = sel_write_member,
378 };
379
380 static ssize_t selinux_transaction_write(struct file *file, const char __user *buf, size_t size, loff_t *pos)
381 {
382         ino_t ino =  file->f_dentry->d_inode->i_ino;
383         char *data;
384         ssize_t rv;
385
386         if (ino >= sizeof(write_op)/sizeof(write_op[0]) || !write_op[ino])
387                 return -EINVAL;
388
389         data = simple_transaction_get(file, buf, size);
390         if (IS_ERR(data))
391                 return PTR_ERR(data);
392
393         rv =  write_op[ino](file, data, size);
394         if (rv>0) {
395                 simple_transaction_set(file, rv);
396                 rv = size;
397         }
398         return rv;
399 }
400
401 static struct file_operations transaction_ops = {
402         .write          = selinux_transaction_write,
403         .read           = simple_transaction_read,
404         .release        = simple_transaction_release,
405 };
406
407 /*
408  * payload - write methods
409  * If the method has a response, the response should be put in buf,
410  * and the length returned.  Otherwise return 0 or and -error.
411  */
412
413 static ssize_t sel_write_access(struct file * file, char *buf, size_t size)
414 {
415         char *scon, *tcon;
416         u32 ssid, tsid;
417         u16 tclass;
418         u32 req;
419         struct av_decision avd;
420         ssize_t length;
421
422         length = task_has_security(current, SECURITY__COMPUTE_AV);
423         if (length)
424                 return length;
425
426         length = -ENOMEM;
427         scon = kzalloc(size+1, GFP_KERNEL);
428         if (!scon)
429                 return length;
430
431         tcon = kzalloc(size+1, GFP_KERNEL);
432         if (!tcon)
433                 goto out;
434
435         length = -EINVAL;
436         if (sscanf(buf, "%s %s %hu %x", scon, tcon, &tclass, &req) != 4)
437                 goto out2;
438
439         length = security_context_to_sid(scon, strlen(scon)+1, &ssid);
440         if (length < 0)
441                 goto out2;
442         length = security_context_to_sid(tcon, strlen(tcon)+1, &tsid);
443         if (length < 0)
444                 goto out2;
445
446         length = security_compute_av(ssid, tsid, tclass, req, &avd);
447         if (length < 0)
448                 goto out2;
449
450         length = scnprintf(buf, SIMPLE_TRANSACTION_LIMIT,
451                           "%x %x %x %x %u",
452                           avd.allowed, avd.decided,
453                           avd.auditallow, avd.auditdeny,
454                           avd.seqno);
455 out2:
456         kfree(tcon);
457 out:
458         kfree(scon);
459         return length;
460 }
461
462 static ssize_t sel_write_create(struct file * file, char *buf, size_t size)
463 {
464         char *scon, *tcon;
465         u32 ssid, tsid, newsid;
466         u16 tclass;
467         ssize_t length;
468         char *newcon;
469         u32 len;
470
471         length = task_has_security(current, SECURITY__COMPUTE_CREATE);
472         if (length)
473                 return length;
474
475         length = -ENOMEM;
476         scon = kzalloc(size+1, GFP_KERNEL);
477         if (!scon)
478                 return length;
479
480         tcon = kzalloc(size+1, GFP_KERNEL);
481         if (!tcon)
482                 goto out;
483
484         length = -EINVAL;
485         if (sscanf(buf, "%s %s %hu", scon, tcon, &tclass) != 3)
486                 goto out2;
487
488         length = security_context_to_sid(scon, strlen(scon)+1, &ssid);
489         if (length < 0)
490                 goto out2;
491         length = security_context_to_sid(tcon, strlen(tcon)+1, &tsid);
492         if (length < 0)
493                 goto out2;
494
495         length = security_transition_sid(ssid, tsid, tclass, &newsid);
496         if (length < 0)
497                 goto out2;
498
499         length = security_sid_to_context(newsid, &newcon, &len);
500         if (length < 0)
501                 goto out2;
502
503         if (len > SIMPLE_TRANSACTION_LIMIT) {
504                 printk(KERN_ERR "%s:  context size (%u) exceeds payload "
505                        "max\n", __FUNCTION__, len);
506                 length = -ERANGE;
507                 goto out3;
508         }
509
510         memcpy(buf, newcon, len);
511         length = len;
512 out3:
513         kfree(newcon);
514 out2:
515         kfree(tcon);
516 out:
517         kfree(scon);
518         return length;
519 }
520
521 static ssize_t sel_write_relabel(struct file * file, char *buf, size_t size)
522 {
523         char *scon, *tcon;
524         u32 ssid, tsid, newsid;
525         u16 tclass;
526         ssize_t length;
527         char *newcon;
528         u32 len;
529
530         length = task_has_security(current, SECURITY__COMPUTE_RELABEL);
531         if (length)
532                 return length;
533
534         length = -ENOMEM;
535         scon = kzalloc(size+1, GFP_KERNEL);
536         if (!scon)
537                 return length;
538
539         tcon = kzalloc(size+1, GFP_KERNEL);
540         if (!tcon)
541                 goto out;
542
543         length = -EINVAL;
544         if (sscanf(buf, "%s %s %hu", scon, tcon, &tclass) != 3)
545                 goto out2;
546
547         length = security_context_to_sid(scon, strlen(scon)+1, &ssid);
548         if (length < 0)
549                 goto out2;
550         length = security_context_to_sid(tcon, strlen(tcon)+1, &tsid);
551         if (length < 0)
552                 goto out2;
553
554         length = security_change_sid(ssid, tsid, tclass, &newsid);
555         if (length < 0)
556                 goto out2;
557
558         length = security_sid_to_context(newsid, &newcon, &len);
559         if (length < 0)
560                 goto out2;
561
562         if (len > SIMPLE_TRANSACTION_LIMIT) {
563                 length = -ERANGE;
564                 goto out3;
565         }
566
567         memcpy(buf, newcon, len);
568         length = len;
569 out3:
570         kfree(newcon);
571 out2:
572         kfree(tcon);
573 out:
574         kfree(scon);
575         return length;
576 }
577
578 static ssize_t sel_write_user(struct file * file, char *buf, size_t size)
579 {
580         char *con, *user, *ptr;
581         u32 sid, *sids;
582         ssize_t length;
583         char *newcon;
584         int i, rc;
585         u32 len, nsids;
586
587         length = task_has_security(current, SECURITY__COMPUTE_USER);
588         if (length)
589                 return length;
590
591         length = -ENOMEM;
592         con = kzalloc(size+1, GFP_KERNEL);
593         if (!con)
594                 return length;
595
596         user = kzalloc(size+1, GFP_KERNEL);
597         if (!user)
598                 goto out;
599
600         length = -EINVAL;
601         if (sscanf(buf, "%s %s", con, user) != 2)
602                 goto out2;
603
604         length = security_context_to_sid(con, strlen(con)+1, &sid);
605         if (length < 0)
606                 goto out2;
607
608         length = security_get_user_sids(sid, user, &sids, &nsids);
609         if (length < 0)
610                 goto out2;
611
612         length = sprintf(buf, "%u", nsids) + 1;
613         ptr = buf + length;
614         for (i = 0; i < nsids; i++) {
615                 rc = security_sid_to_context(sids[i], &newcon, &len);
616                 if (rc) {
617                         length = rc;
618                         goto out3;
619                 }
620                 if ((length + len) >= SIMPLE_TRANSACTION_LIMIT) {
621                         kfree(newcon);
622                         length = -ERANGE;
623                         goto out3;
624                 }
625                 memcpy(ptr, newcon, len);
626                 kfree(newcon);
627                 ptr += len;
628                 length += len;
629         }
630 out3:
631         kfree(sids);
632 out2:
633         kfree(user);
634 out:
635         kfree(con);
636         return length;
637 }
638
639 static ssize_t sel_write_member(struct file * file, char *buf, size_t size)
640 {
641         char *scon, *tcon;
642         u32 ssid, tsid, newsid;
643         u16 tclass;
644         ssize_t length;
645         char *newcon;
646         u32 len;
647
648         length = task_has_security(current, SECURITY__COMPUTE_MEMBER);
649         if (length)
650                 return length;
651
652         length = -ENOMEM;
653         scon = kzalloc(size+1, GFP_KERNEL);
654         if (!scon)
655                 return length;
656
657         tcon = kzalloc(size+1, GFP_KERNEL);
658         if (!tcon)
659                 goto out;
660
661         length = -EINVAL;
662         if (sscanf(buf, "%s %s %hu", scon, tcon, &tclass) != 3)
663                 goto out2;
664
665         length = security_context_to_sid(scon, strlen(scon)+1, &ssid);
666         if (length < 0)
667                 goto out2;
668         length = security_context_to_sid(tcon, strlen(tcon)+1, &tsid);
669         if (length < 0)
670                 goto out2;
671
672         length = security_member_sid(ssid, tsid, tclass, &newsid);
673         if (length < 0)
674                 goto out2;
675
676         length = security_sid_to_context(newsid, &newcon, &len);
677         if (length < 0)
678                 goto out2;
679
680         if (len > SIMPLE_TRANSACTION_LIMIT) {
681                 printk(KERN_ERR "%s:  context size (%u) exceeds payload "
682                        "max\n", __FUNCTION__, len);
683                 length = -ERANGE;
684                 goto out3;
685         }
686
687         memcpy(buf, newcon, len);
688         length = len;
689 out3:
690         kfree(newcon);
691 out2:
692         kfree(tcon);
693 out:
694         kfree(scon);
695         return length;
696 }
697
698 static struct inode *sel_make_inode(struct super_block *sb, int mode)
699 {
700         struct inode *ret = new_inode(sb);
701
702         if (ret) {
703                 ret->i_mode = mode;
704                 ret->i_uid = ret->i_gid = 0;
705                 ret->i_blksize = PAGE_CACHE_SIZE;
706                 ret->i_blocks = 0;
707                 ret->i_atime = ret->i_mtime = ret->i_ctime = CURRENT_TIME;
708         }
709         return ret;
710 }
711
712 #define BOOL_INO_OFFSET 30
713
714 static ssize_t sel_read_bool(struct file *filep, char __user *buf,
715                              size_t count, loff_t *ppos)
716 {
717         char *page = NULL;
718         ssize_t length;
719         ssize_t end;
720         ssize_t ret;
721         int cur_enforcing;
722         struct inode *inode;
723
724         down(&sel_sem);
725
726         ret = -EFAULT;
727
728         /* check to see if this file has been deleted */
729         if (!filep->f_op)
730                 goto out;
731
732         if (count > PAGE_SIZE) {
733                 ret = -EINVAL;
734                 goto out;
735         }
736         if (!(page = (char*)get_zeroed_page(GFP_KERNEL))) {
737                 ret = -ENOMEM;
738                 goto out;
739         }
740
741         inode = filep->f_dentry->d_inode;
742         cur_enforcing = security_get_bool_value(inode->i_ino - BOOL_INO_OFFSET);
743         if (cur_enforcing < 0) {
744                 ret = cur_enforcing;
745                 goto out;
746         }
747
748         length = scnprintf(page, PAGE_SIZE, "%d %d", cur_enforcing,
749                           bool_pending_values[inode->i_ino - BOOL_INO_OFFSET]);
750         if (length < 0) {
751                 ret = length;
752                 goto out;
753         }
754
755         if (*ppos >= length) {
756                 ret = 0;
757                 goto out;
758         }
759         if (count + *ppos > length)
760                 count = length - *ppos;
761         end = count + *ppos;
762         if (copy_to_user(buf, (char *) page + *ppos, count)) {
763                 ret = -EFAULT;
764                 goto out;
765         }
766         *ppos = end;
767         ret = count;
768 out:
769         up(&sel_sem);
770         if (page)
771                 free_page((unsigned long)page);
772         return ret;
773 }
774
775 static ssize_t sel_write_bool(struct file *filep, const char __user *buf,
776                               size_t count, loff_t *ppos)
777 {
778         char *page = NULL;
779         ssize_t length = -EFAULT;
780         int new_value;
781         struct inode *inode;
782
783         down(&sel_sem);
784
785         length = task_has_security(current, SECURITY__SETBOOL);
786         if (length)
787                 goto out;
788
789         /* check to see if this file has been deleted */
790         if (!filep->f_op)
791                 goto out;
792
793         if (count >= PAGE_SIZE) {
794                 length = -ENOMEM;
795                 goto out;
796         }
797         if (*ppos != 0) {
798                 /* No partial writes. */
799                 goto out;
800         }
801         page = (char*)get_zeroed_page(GFP_KERNEL);
802         if (!page) {
803                 length = -ENOMEM;
804                 goto out;
805         }
806
807         if (copy_from_user(page, buf, count))
808                 goto out;
809
810         length = -EINVAL;
811         if (sscanf(page, "%d", &new_value) != 1)
812                 goto out;
813
814         if (new_value)
815                 new_value = 1;
816
817         inode = filep->f_dentry->d_inode;
818         bool_pending_values[inode->i_ino - BOOL_INO_OFFSET] = new_value;
819         length = count;
820
821 out:
822         up(&sel_sem);
823         if (page)
824                 free_page((unsigned long) page);
825         return length;
826 }
827
828 static struct file_operations sel_bool_ops = {
829         .read           = sel_read_bool,
830         .write          = sel_write_bool,
831 };
832
833 static ssize_t sel_commit_bools_write(struct file *filep,
834                                       const char __user *buf,
835                                       size_t count, loff_t *ppos)
836 {
837         char *page = NULL;
838         ssize_t length = -EFAULT;
839         int new_value;
840
841         down(&sel_sem);
842
843         length = task_has_security(current, SECURITY__SETBOOL);
844         if (length)
845                 goto out;
846
847         /* check to see if this file has been deleted */
848         if (!filep->f_op)
849                 goto out;
850
851         if (count >= PAGE_SIZE) {
852                 length = -ENOMEM;
853                 goto out;
854         }
855         if (*ppos != 0) {
856                 /* No partial writes. */
857                 goto out;
858         }
859         page = (char*)get_zeroed_page(GFP_KERNEL);
860         if (!page) {
861                 length = -ENOMEM;
862                 goto out;
863         }
864
865         if (copy_from_user(page, buf, count))
866                 goto out;
867
868         length = -EINVAL;
869         if (sscanf(page, "%d", &new_value) != 1)
870                 goto out;
871
872         if (new_value && bool_pending_values) {
873                 security_set_bools(bool_num, bool_pending_values);
874         }
875
876         length = count;
877
878 out:
879         up(&sel_sem);
880         if (page)
881                 free_page((unsigned long) page);
882         return length;
883 }
884
885 static struct file_operations sel_commit_bools_ops = {
886         .write          = sel_commit_bools_write,
887 };
888
889 /* delete booleans - partial revoke() from
890  * fs/proc/generic.c proc_kill_inodes */
891 static void sel_remove_bools(struct dentry *de)
892 {
893         struct list_head *p, *node;
894         struct super_block *sb = de->d_sb;
895
896         spin_lock(&dcache_lock);
897         node = de->d_subdirs.next;
898         while (node != &de->d_subdirs) {
899                 struct dentry *d = list_entry(node, struct dentry, d_child);
900                 list_del_init(node);
901
902                 if (d->d_inode) {
903                         d = dget_locked(d);
904                         spin_unlock(&dcache_lock);
905                         d_delete(d);
906                         simple_unlink(de->d_inode, d);
907                         dput(d);
908                         spin_lock(&dcache_lock);
909                 }
910                 node = de->d_subdirs.next;
911         }
912
913         spin_unlock(&dcache_lock);
914
915         file_list_lock();
916         list_for_each(p, &sb->s_files) {
917                 struct file * filp = list_entry(p, struct file, f_list);
918                 struct dentry * dentry = filp->f_dentry;
919
920                 if (dentry->d_parent != de) {
921                         continue;
922                 }
923                 filp->f_op = NULL;
924         }
925         file_list_unlock();
926 }
927
928 #define BOOL_DIR_NAME "booleans"
929
930 static int sel_make_bools(void)
931 {
932         int i, ret = 0;
933         ssize_t len;
934         struct dentry *dentry = NULL;
935         struct dentry *dir = bool_dir;
936         struct inode *inode = NULL;
937         struct inode_security_struct *isec;
938         char **names = NULL, *page;
939         int num;
940         int *values = NULL;
941         u32 sid;
942
943         /* remove any existing files */
944         kfree(bool_pending_values);
945         bool_pending_values = NULL;
946
947         sel_remove_bools(dir);
948
949         if (!(page = (char*)get_zeroed_page(GFP_KERNEL)))
950                 return -ENOMEM;
951
952         ret = security_get_bools(&num, &names, &values);
953         if (ret != 0)
954                 goto out;
955
956         for (i = 0; i < num; i++) {
957                 dentry = d_alloc_name(dir, names[i]);
958                 if (!dentry) {
959                         ret = -ENOMEM;
960                         goto err;
961                 }
962                 inode = sel_make_inode(dir->d_sb, S_IFREG | S_IRUGO | S_IWUSR);
963                 if (!inode) {
964                         ret = -ENOMEM;
965                         goto err;
966                 }
967
968                 len = snprintf(page, PAGE_SIZE, "/%s/%s", BOOL_DIR_NAME, names[i]);
969                 if (len < 0) {
970                         ret = -EINVAL;
971                         goto err;
972                 } else if (len >= PAGE_SIZE) {
973                         ret = -ENAMETOOLONG;
974                         goto err;
975                 }
976                 isec = (struct inode_security_struct*)inode->i_security;
977                 if ((ret = security_genfs_sid("selinuxfs", page, SECCLASS_FILE, &sid)))
978                         goto err;
979                 isec->sid = sid;
980                 isec->initialized = 1;
981                 inode->i_fop = &sel_bool_ops;
982                 inode->i_ino = i + BOOL_INO_OFFSET;
983                 d_add(dentry, inode);
984         }
985         bool_num = num;
986         bool_pending_values = values;
987 out:
988         free_page((unsigned long)page);
989         if (names) {
990                 for (i = 0; i < num; i++)
991                         kfree(names[i]);
992                 kfree(names);
993         }
994         return ret;
995 err:
996         kfree(values);
997         d_genocide(dir);
998         ret = -ENOMEM;
999         goto out;
1000 }
1001
1002 #define NULL_FILE_NAME "null"
1003
1004 struct dentry *selinux_null = NULL;
1005
1006 static ssize_t sel_read_avc_cache_threshold(struct file *filp, char __user *buf,
1007                                             size_t count, loff_t *ppos)
1008 {
1009         char tmpbuf[TMPBUFLEN];
1010         ssize_t length;
1011
1012         length = scnprintf(tmpbuf, TMPBUFLEN, "%u", avc_cache_threshold);
1013         return simple_read_from_buffer(buf, count, ppos, tmpbuf, length);
1014 }
1015
1016 static ssize_t sel_write_avc_cache_threshold(struct file * file,
1017                                              const char __user * buf,
1018                                              size_t count, loff_t *ppos)
1019
1020 {
1021         char *page;
1022         ssize_t ret;
1023         int new_value;
1024
1025         if (count >= PAGE_SIZE) {
1026                 ret = -ENOMEM;
1027                 goto out;
1028         }
1029
1030         if (*ppos != 0) {
1031                 /* No partial writes. */
1032                 ret = -EINVAL;
1033                 goto out;
1034         }
1035
1036         page = (char*)get_zeroed_page(GFP_KERNEL);
1037         if (!page) {
1038                 ret = -ENOMEM;
1039                 goto out;
1040         }
1041
1042         if (copy_from_user(page, buf, count)) {
1043                 ret = -EFAULT;
1044                 goto out_free;
1045         }
1046
1047         if (sscanf(page, "%u", &new_value) != 1) {
1048                 ret = -EINVAL;
1049                 goto out;
1050         }
1051
1052         if (new_value != avc_cache_threshold) {
1053                 ret = task_has_security(current, SECURITY__SETSECPARAM);
1054                 if (ret)
1055                         goto out_free;
1056                 avc_cache_threshold = new_value;
1057         }
1058         ret = count;
1059 out_free:
1060         free_page((unsigned long)page);
1061 out:
1062         return ret;
1063 }
1064
1065 static ssize_t sel_read_avc_hash_stats(struct file *filp, char __user *buf,
1066                                        size_t count, loff_t *ppos)
1067 {
1068         char *page;
1069         ssize_t ret = 0;
1070
1071         page = (char *)__get_free_page(GFP_KERNEL);
1072         if (!page) {
1073                 ret = -ENOMEM;
1074                 goto out;
1075         }
1076         ret = avc_get_hash_stats(page);
1077         if (ret >= 0)
1078                 ret = simple_read_from_buffer(buf, count, ppos, page, ret);
1079         free_page((unsigned long)page);
1080 out:
1081         return ret;
1082 }
1083
1084 static struct file_operations sel_avc_cache_threshold_ops = {
1085         .read           = sel_read_avc_cache_threshold,
1086         .write          = sel_write_avc_cache_threshold,
1087 };
1088
1089 static struct file_operations sel_avc_hash_stats_ops = {
1090         .read           = sel_read_avc_hash_stats,
1091 };
1092
1093 #ifdef CONFIG_SECURITY_SELINUX_AVC_STATS
1094 static struct avc_cache_stats *sel_avc_get_stat_idx(loff_t *idx)
1095 {
1096         int cpu;
1097
1098         for (cpu = *idx; cpu < NR_CPUS; ++cpu) {
1099                 if (!cpu_possible(cpu))
1100                         continue;
1101                 *idx = cpu + 1;
1102                 return &per_cpu(avc_cache_stats, cpu);
1103         }
1104         return NULL;
1105 }
1106
1107 static void *sel_avc_stats_seq_start(struct seq_file *seq, loff_t *pos)
1108 {
1109         loff_t n = *pos - 1;
1110
1111         if (*pos == 0)
1112                 return SEQ_START_TOKEN;
1113
1114         return sel_avc_get_stat_idx(&n);
1115 }
1116
1117 static void *sel_avc_stats_seq_next(struct seq_file *seq, void *v, loff_t *pos)
1118 {
1119         return sel_avc_get_stat_idx(pos);
1120 }
1121
1122 static int sel_avc_stats_seq_show(struct seq_file *seq, void *v)
1123 {
1124         struct avc_cache_stats *st = v;
1125
1126         if (v == SEQ_START_TOKEN)
1127                 seq_printf(seq, "lookups hits misses allocations reclaims "
1128                            "frees\n");
1129         else
1130                 seq_printf(seq, "%u %u %u %u %u %u\n", st->lookups,
1131                            st->hits, st->misses, st->allocations,
1132                            st->reclaims, st->frees);
1133         return 0;
1134 }
1135
1136 static void sel_avc_stats_seq_stop(struct seq_file *seq, void *v)
1137 { }
1138
1139 static struct seq_operations sel_avc_cache_stats_seq_ops = {
1140         .start          = sel_avc_stats_seq_start,
1141         .next           = sel_avc_stats_seq_next,
1142         .show           = sel_avc_stats_seq_show,
1143         .stop           = sel_avc_stats_seq_stop,
1144 };
1145
1146 static int sel_open_avc_cache_stats(struct inode *inode, struct file *file)
1147 {
1148         return seq_open(file, &sel_avc_cache_stats_seq_ops);
1149 }
1150
1151 static struct file_operations sel_avc_cache_stats_ops = {
1152         .open           = sel_open_avc_cache_stats,
1153         .read           = seq_read,
1154         .llseek         = seq_lseek,
1155         .release        = seq_release,
1156 };
1157 #endif
1158
1159 static int sel_make_avc_files(struct dentry *dir)
1160 {
1161         int i, ret = 0;
1162         static struct tree_descr files[] = {
1163                 { "cache_threshold",
1164                   &sel_avc_cache_threshold_ops, S_IRUGO|S_IWUSR },
1165                 { "hash_stats", &sel_avc_hash_stats_ops, S_IRUGO },
1166 #ifdef CONFIG_SECURITY_SELINUX_AVC_STATS
1167                 { "cache_stats", &sel_avc_cache_stats_ops, S_IRUGO },
1168 #endif
1169         };
1170
1171         for (i = 0; i < sizeof (files) / sizeof (files[0]); i++) {
1172                 struct inode *inode;
1173                 struct dentry *dentry;
1174
1175                 dentry = d_alloc_name(dir, files[i].name);
1176                 if (!dentry) {
1177                         ret = -ENOMEM;
1178                         goto err;
1179                 }
1180
1181                 inode = sel_make_inode(dir->d_sb, S_IFREG|files[i].mode);
1182                 if (!inode) {
1183                         ret = -ENOMEM;
1184                         goto err;
1185                 }
1186                 inode->i_fop = files[i].ops;
1187                 d_add(dentry, inode);
1188         }
1189 out:
1190         return ret;
1191 err:
1192         d_genocide(dir);
1193         goto out;
1194 }
1195
1196 static int sel_make_dir(struct super_block *sb, struct dentry *dentry)
1197 {
1198         int ret = 0;
1199         struct inode *inode;
1200
1201         inode = sel_make_inode(sb, S_IFDIR | S_IRUGO | S_IXUGO);
1202         if (!inode) {
1203                 ret = -ENOMEM;
1204                 goto out;
1205         }
1206         inode->i_op = &simple_dir_inode_operations;
1207         inode->i_fop = &simple_dir_operations;
1208         d_add(dentry, inode);
1209 out:
1210         return ret;
1211 }
1212
1213 static int sel_fill_super(struct super_block * sb, void * data, int silent)
1214 {
1215         int ret;
1216         struct dentry *dentry;
1217         struct inode *inode;
1218         struct inode_security_struct *isec;
1219
1220         static struct tree_descr selinux_files[] = {
1221                 [SEL_LOAD] = {"load", &sel_load_ops, S_IRUSR|S_IWUSR},
1222                 [SEL_ENFORCE] = {"enforce", &sel_enforce_ops, S_IRUGO|S_IWUSR},
1223                 [SEL_CONTEXT] = {"context", &sel_context_ops, S_IRUGO|S_IWUGO},
1224                 [SEL_ACCESS] = {"access", &transaction_ops, S_IRUGO|S_IWUGO},
1225                 [SEL_CREATE] = {"create", &transaction_ops, S_IRUGO|S_IWUGO},
1226                 [SEL_RELABEL] = {"relabel", &transaction_ops, S_IRUGO|S_IWUGO},
1227                 [SEL_USER] = {"user", &transaction_ops, S_IRUGO|S_IWUGO},
1228                 [SEL_POLICYVERS] = {"policyvers", &sel_policyvers_ops, S_IRUGO},
1229                 [SEL_COMMIT_BOOLS] = {"commit_pending_bools", &sel_commit_bools_ops, S_IWUSR},
1230                 [SEL_MLS] = {"mls", &sel_mls_ops, S_IRUGO},
1231                 [SEL_DISABLE] = {"disable", &sel_disable_ops, S_IWUSR},
1232                 [SEL_MEMBER] = {"member", &transaction_ops, S_IRUGO|S_IWUGO},
1233                 [SEL_CHECKREQPROT] = {"checkreqprot", &sel_checkreqprot_ops, S_IRUGO|S_IWUSR},
1234                 /* last one */ {""}
1235         };
1236         ret = simple_fill_super(sb, SELINUX_MAGIC, selinux_files);
1237         if (ret)
1238                 return ret;
1239
1240         dentry = d_alloc_name(sb->s_root, BOOL_DIR_NAME);
1241         if (!dentry)
1242                 return -ENOMEM;
1243
1244         inode = sel_make_inode(sb, S_IFDIR | S_IRUGO | S_IXUGO);
1245         if (!inode)
1246                 goto out;
1247         inode->i_op = &simple_dir_inode_operations;
1248         inode->i_fop = &simple_dir_operations;
1249         d_add(dentry, inode);
1250         bool_dir = dentry;
1251         ret = sel_make_bools();
1252         if (ret)
1253                 goto out;
1254
1255         dentry = d_alloc_name(sb->s_root, NULL_FILE_NAME);
1256         if (!dentry)
1257                 return -ENOMEM;
1258
1259         inode = sel_make_inode(sb, S_IFCHR | S_IRUGO | S_IWUGO);
1260         if (!inode)
1261                 goto out;
1262         isec = (struct inode_security_struct*)inode->i_security;
1263         isec->sid = SECINITSID_DEVNULL;
1264         isec->sclass = SECCLASS_CHR_FILE;
1265         isec->initialized = 1;
1266
1267         init_special_inode(inode, S_IFCHR | S_IRUGO | S_IWUGO, MKDEV(MEM_MAJOR, 3));
1268         d_add(dentry, inode);
1269         selinux_null = dentry;
1270
1271         dentry = d_alloc_name(sb->s_root, "avc");
1272         if (!dentry)
1273                 return -ENOMEM;
1274
1275         ret = sel_make_dir(sb, dentry);
1276         if (ret)
1277                 goto out;
1278
1279         ret = sel_make_avc_files(dentry);
1280         if (ret)
1281                 goto out;
1282
1283         return 0;
1284 out:
1285         dput(dentry);
1286         printk(KERN_ERR "%s:  failed while creating inodes\n", __FUNCTION__);
1287         return -ENOMEM;
1288 }
1289
1290 static struct super_block *sel_get_sb(struct file_system_type *fs_type,
1291                                       int flags, const char *dev_name, void *data)
1292 {
1293         return get_sb_single(fs_type, flags, data, sel_fill_super);
1294 }
1295
1296 static struct file_system_type sel_fs_type = {
1297         .name           = "selinuxfs",
1298         .get_sb         = sel_get_sb,
1299         .kill_sb        = kill_litter_super,
1300 };
1301
1302 struct vfsmount *selinuxfs_mount;
1303
1304 static int __init init_sel_fs(void)
1305 {
1306         int err;
1307
1308         if (!selinux_enabled)
1309                 return 0;
1310         err = register_filesystem(&sel_fs_type);
1311         if (!err) {
1312                 selinuxfs_mount = kern_mount(&sel_fs_type);
1313                 if (IS_ERR(selinuxfs_mount)) {
1314                         printk(KERN_ERR "selinuxfs:  could not mount!\n");
1315                         err = PTR_ERR(selinuxfs_mount);
1316                         selinuxfs_mount = NULL;
1317                 }
1318         }
1319         return err;
1320 }
1321
1322 __initcall(init_sel_fs);
1323
1324 #ifdef CONFIG_SECURITY_SELINUX_DISABLE
1325 void exit_sel_fs(void)
1326 {
1327         unregister_filesystem(&sel_fs_type);
1328 }
1329 #endif