Merge branch 'master' into next
[linux-2.6-block.git] / security / smack / smack_lsm.c
CommitLineData
e114e473
CS
1/*
2 * Simplified MAC Kernel (smack) security module
3 *
4 * This file contains the smack hook function implementations.
5 *
6 * Author:
7 * Casey Schaufler <casey@schaufler-ca.com>
8 *
9 * Copyright (C) 2007 Casey Schaufler <casey@schaufler-ca.com>
10 *
11 * This program is free software; you can redistribute it and/or modify
12 * it under the terms of the GNU General Public License version 2,
13 * as published by the Free Software Foundation.
14 */
15
16#include <linux/xattr.h>
17#include <linux/pagemap.h>
18#include <linux/mount.h>
19#include <linux/stat.h>
20#include <linux/ext2_fs.h>
21#include <linux/kd.h>
22#include <asm/ioctls.h>
23#include <linux/tcp.h>
24#include <linux/udp.h>
25#include <linux/mutex.h>
26#include <linux/pipe_fs_i.h>
27#include <net/netlabel.h>
28#include <net/cipso_ipv4.h>
d20bdda6 29#include <linux/audit.h>
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30
31#include "smack.h"
32
c69e8d9c
DH
33#define task_security(task) (task_cred_xxx((task), security))
34
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35/*
36 * I hope these are the hokeyist lines of code in the module. Casey.
37 */
38#define DEVPTS_SUPER_MAGIC 0x1cd1
39#define SOCKFS_MAGIC 0x534F434B
40#define TMPFS_MAGIC 0x01021994
41
42/**
43 * smk_fetch - Fetch the smack label from a file.
44 * @ip: a pointer to the inode
45 * @dp: a pointer to the dentry
46 *
47 * Returns a pointer to the master list entry for the Smack label
48 * or NULL if there was no label to fetch.
49 */
50static char *smk_fetch(struct inode *ip, struct dentry *dp)
51{
52 int rc;
53 char in[SMK_LABELLEN];
54
55 if (ip->i_op->getxattr == NULL)
56 return NULL;
57
58 rc = ip->i_op->getxattr(dp, XATTR_NAME_SMACK, in, SMK_LABELLEN);
59 if (rc < 0)
60 return NULL;
61
62 return smk_import(in, rc);
63}
64
65/**
66 * new_inode_smack - allocate an inode security blob
67 * @smack: a pointer to the Smack label to use in the blob
68 *
69 * Returns the new blob or NULL if there's no memory available
70 */
71struct inode_smack *new_inode_smack(char *smack)
72{
73 struct inode_smack *isp;
74
75 isp = kzalloc(sizeof(struct inode_smack), GFP_KERNEL);
76 if (isp == NULL)
77 return NULL;
78
79 isp->smk_inode = smack;
80 isp->smk_flags = 0;
81 mutex_init(&isp->smk_lock);
82
83 return isp;
84}
85
86/*
87 * LSM hooks.
88 * We he, that is fun!
89 */
90
91/**
5cd9c58f 92 * smack_ptrace_may_access - Smack approval on PTRACE_ATTACH
e114e473 93 * @ctp: child task pointer
251a2a95 94 * @mode: ptrace attachment mode
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CS
95 *
96 * Returns 0 if access is OK, an error code otherwise
97 *
98 * Do the capability checks, and require read and write.
99 */
5cd9c58f 100static int smack_ptrace_may_access(struct task_struct *ctp, unsigned int mode)
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CS
101{
102 int rc;
103
5cd9c58f 104 rc = cap_ptrace_may_access(ctp, mode);
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105 if (rc != 0)
106 return rc;
107
d84f4f99 108 rc = smk_access(current_security(), task_security(ctp), MAY_READWRITE);
5cd9c58f 109 if (rc != 0 && capable(CAP_MAC_OVERRIDE))
e114e473 110 return 0;
5cd9c58f
DH
111 return rc;
112}
113
114/**
115 * smack_ptrace_traceme - Smack approval on PTRACE_TRACEME
116 * @ptp: parent task pointer
117 *
118 * Returns 0 if access is OK, an error code otherwise
119 *
120 * Do the capability checks, and require read and write.
121 */
122static int smack_ptrace_traceme(struct task_struct *ptp)
123{
124 int rc;
125
126 rc = cap_ptrace_traceme(ptp);
127 if (rc != 0)
128 return rc;
e114e473 129
d84f4f99 130 rc = smk_access(task_security(ptp), current_security(), MAY_READWRITE);
5cd9c58f
DH
131 if (rc != 0 && has_capability(ptp, CAP_MAC_OVERRIDE))
132 return 0;
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133 return rc;
134}
135
136/**
137 * smack_syslog - Smack approval on syslog
138 * @type: message type
139 *
140 * Require that the task has the floor label
141 *
142 * Returns 0 on success, error code otherwise.
143 */
144static int smack_syslog(int type)
145{
146 int rc;
86a264ab 147 char *sp = current_security();
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148
149 rc = cap_syslog(type);
150 if (rc != 0)
151 return rc;
152
153 if (capable(CAP_MAC_OVERRIDE))
154 return 0;
155
156 if (sp != smack_known_floor.smk_known)
157 rc = -EACCES;
158
159 return rc;
160}
161
162
163/*
164 * Superblock Hooks.
165 */
166
167/**
168 * smack_sb_alloc_security - allocate a superblock blob
169 * @sb: the superblock getting the blob
170 *
171 * Returns 0 on success or -ENOMEM on error.
172 */
173static int smack_sb_alloc_security(struct super_block *sb)
174{
175 struct superblock_smack *sbsp;
176
177 sbsp = kzalloc(sizeof(struct superblock_smack), GFP_KERNEL);
178
179 if (sbsp == NULL)
180 return -ENOMEM;
181
182 sbsp->smk_root = smack_known_floor.smk_known;
183 sbsp->smk_default = smack_known_floor.smk_known;
184 sbsp->smk_floor = smack_known_floor.smk_known;
185 sbsp->smk_hat = smack_known_hat.smk_known;
186 sbsp->smk_initialized = 0;
187 spin_lock_init(&sbsp->smk_sblock);
188
189 sb->s_security = sbsp;
190
191 return 0;
192}
193
194/**
195 * smack_sb_free_security - free a superblock blob
196 * @sb: the superblock getting the blob
197 *
198 */
199static void smack_sb_free_security(struct super_block *sb)
200{
201 kfree(sb->s_security);
202 sb->s_security = NULL;
203}
204
205/**
206 * smack_sb_copy_data - copy mount options data for processing
e114e473 207 * @orig: where to start
251a2a95 208 * @smackopts: mount options string
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209 *
210 * Returns 0 on success or -ENOMEM on error.
211 *
212 * Copy the Smack specific mount options out of the mount
213 * options list.
214 */
e0007529 215static int smack_sb_copy_data(char *orig, char *smackopts)
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CS
216{
217 char *cp, *commap, *otheropts, *dp;
218
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219 otheropts = (char *)get_zeroed_page(GFP_KERNEL);
220 if (otheropts == NULL)
221 return -ENOMEM;
222
223 for (cp = orig, commap = orig; commap != NULL; cp = commap + 1) {
224 if (strstr(cp, SMK_FSDEFAULT) == cp)
225 dp = smackopts;
226 else if (strstr(cp, SMK_FSFLOOR) == cp)
227 dp = smackopts;
228 else if (strstr(cp, SMK_FSHAT) == cp)
229 dp = smackopts;
230 else if (strstr(cp, SMK_FSROOT) == cp)
231 dp = smackopts;
232 else
233 dp = otheropts;
234
235 commap = strchr(cp, ',');
236 if (commap != NULL)
237 *commap = '\0';
238
239 if (*dp != '\0')
240 strcat(dp, ",");
241 strcat(dp, cp);
242 }
243
244 strcpy(orig, otheropts);
245 free_page((unsigned long)otheropts);
246
247 return 0;
248}
249
250/**
251 * smack_sb_kern_mount - Smack specific mount processing
252 * @sb: the file system superblock
12204e24 253 * @flags: the mount flags
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254 * @data: the smack mount options
255 *
256 * Returns 0 on success, an error code on failure
257 */
12204e24 258static int smack_sb_kern_mount(struct super_block *sb, int flags, void *data)
e114e473
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259{
260 struct dentry *root = sb->s_root;
261 struct inode *inode = root->d_inode;
262 struct superblock_smack *sp = sb->s_security;
263 struct inode_smack *isp;
264 char *op;
265 char *commap;
266 char *nsp;
267
268 spin_lock(&sp->smk_sblock);
269 if (sp->smk_initialized != 0) {
270 spin_unlock(&sp->smk_sblock);
271 return 0;
272 }
273 sp->smk_initialized = 1;
274 spin_unlock(&sp->smk_sblock);
275
276 for (op = data; op != NULL; op = commap) {
277 commap = strchr(op, ',');
278 if (commap != NULL)
279 *commap++ = '\0';
280
281 if (strncmp(op, SMK_FSHAT, strlen(SMK_FSHAT)) == 0) {
282 op += strlen(SMK_FSHAT);
283 nsp = smk_import(op, 0);
284 if (nsp != NULL)
285 sp->smk_hat = nsp;
286 } else if (strncmp(op, SMK_FSFLOOR, strlen(SMK_FSFLOOR)) == 0) {
287 op += strlen(SMK_FSFLOOR);
288 nsp = smk_import(op, 0);
289 if (nsp != NULL)
290 sp->smk_floor = nsp;
291 } else if (strncmp(op, SMK_FSDEFAULT,
292 strlen(SMK_FSDEFAULT)) == 0) {
293 op += strlen(SMK_FSDEFAULT);
294 nsp = smk_import(op, 0);
295 if (nsp != NULL)
296 sp->smk_default = nsp;
297 } else if (strncmp(op, SMK_FSROOT, strlen(SMK_FSROOT)) == 0) {
298 op += strlen(SMK_FSROOT);
299 nsp = smk_import(op, 0);
300 if (nsp != NULL)
301 sp->smk_root = nsp;
302 }
303 }
304
305 /*
306 * Initialize the root inode.
307 */
308 isp = inode->i_security;
309 if (isp == NULL)
310 inode->i_security = new_inode_smack(sp->smk_root);
311 else
312 isp->smk_inode = sp->smk_root;
313
314 return 0;
315}
316
317/**
318 * smack_sb_statfs - Smack check on statfs
319 * @dentry: identifies the file system in question
320 *
321 * Returns 0 if current can read the floor of the filesystem,
322 * and error code otherwise
323 */
324static int smack_sb_statfs(struct dentry *dentry)
325{
326 struct superblock_smack *sbp = dentry->d_sb->s_security;
327
328 return smk_curacc(sbp->smk_floor, MAY_READ);
329}
330
331/**
332 * smack_sb_mount - Smack check for mounting
333 * @dev_name: unused
251a2a95 334 * @path: mount point
e114e473
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335 * @type: unused
336 * @flags: unused
337 * @data: unused
338 *
339 * Returns 0 if current can write the floor of the filesystem
340 * being mounted on, an error code otherwise.
341 */
b5266eb4 342static int smack_sb_mount(char *dev_name, struct path *path,
e114e473
CS
343 char *type, unsigned long flags, void *data)
344{
b5266eb4 345 struct superblock_smack *sbp = path->mnt->mnt_sb->s_security;
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CS
346
347 return smk_curacc(sbp->smk_floor, MAY_WRITE);
348}
349
350/**
351 * smack_sb_umount - Smack check for unmounting
352 * @mnt: file system to unmount
353 * @flags: unused
354 *
355 * Returns 0 if current can write the floor of the filesystem
356 * being unmounted, an error code otherwise.
357 */
358static int smack_sb_umount(struct vfsmount *mnt, int flags)
359{
360 struct superblock_smack *sbp;
361
362 sbp = mnt->mnt_sb->s_security;
363
364 return smk_curacc(sbp->smk_floor, MAY_WRITE);
365}
366
367/*
368 * Inode hooks
369 */
370
371/**
372 * smack_inode_alloc_security - allocate an inode blob
251a2a95 373 * @inode: the inode in need of a blob
e114e473
CS
374 *
375 * Returns 0 if it gets a blob, -ENOMEM otherwise
376 */
377static int smack_inode_alloc_security(struct inode *inode)
378{
86a264ab 379 inode->i_security = new_inode_smack(current_security());
e114e473
CS
380 if (inode->i_security == NULL)
381 return -ENOMEM;
382 return 0;
383}
384
385/**
386 * smack_inode_free_security - free an inode blob
251a2a95 387 * @inode: the inode with a blob
e114e473
CS
388 *
389 * Clears the blob pointer in inode
390 */
391static void smack_inode_free_security(struct inode *inode)
392{
393 kfree(inode->i_security);
394 inode->i_security = NULL;
395}
396
397/**
398 * smack_inode_init_security - copy out the smack from an inode
399 * @inode: the inode
400 * @dir: unused
401 * @name: where to put the attribute name
402 * @value: where to put the attribute value
403 * @len: where to put the length of the attribute
404 *
405 * Returns 0 if it all works out, -ENOMEM if there's no memory
406 */
407static int smack_inode_init_security(struct inode *inode, struct inode *dir,
408 char **name, void **value, size_t *len)
409{
410 char *isp = smk_of_inode(inode);
411
412 if (name) {
413 *name = kstrdup(XATTR_SMACK_SUFFIX, GFP_KERNEL);
414 if (*name == NULL)
415 return -ENOMEM;
416 }
417
418 if (value) {
419 *value = kstrdup(isp, GFP_KERNEL);
420 if (*value == NULL)
421 return -ENOMEM;
422 }
423
424 if (len)
425 *len = strlen(isp) + 1;
426
427 return 0;
428}
429
430/**
431 * smack_inode_link - Smack check on link
432 * @old_dentry: the existing object
433 * @dir: unused
434 * @new_dentry: the new object
435 *
436 * Returns 0 if access is permitted, an error code otherwise
437 */
438static int smack_inode_link(struct dentry *old_dentry, struct inode *dir,
439 struct dentry *new_dentry)
440{
441 int rc;
442 char *isp;
443
444 isp = smk_of_inode(old_dentry->d_inode);
445 rc = smk_curacc(isp, MAY_WRITE);
446
447 if (rc == 0 && new_dentry->d_inode != NULL) {
448 isp = smk_of_inode(new_dentry->d_inode);
449 rc = smk_curacc(isp, MAY_WRITE);
450 }
451
452 return rc;
453}
454
455/**
456 * smack_inode_unlink - Smack check on inode deletion
457 * @dir: containing directory object
458 * @dentry: file to unlink
459 *
460 * Returns 0 if current can write the containing directory
461 * and the object, error code otherwise
462 */
463static int smack_inode_unlink(struct inode *dir, struct dentry *dentry)
464{
465 struct inode *ip = dentry->d_inode;
466 int rc;
467
468 /*
469 * You need write access to the thing you're unlinking
470 */
471 rc = smk_curacc(smk_of_inode(ip), MAY_WRITE);
472 if (rc == 0)
473 /*
474 * You also need write access to the containing directory
475 */
476 rc = smk_curacc(smk_of_inode(dir), MAY_WRITE);
477
478 return rc;
479}
480
481/**
482 * smack_inode_rmdir - Smack check on directory deletion
483 * @dir: containing directory object
484 * @dentry: directory to unlink
485 *
486 * Returns 0 if current can write the containing directory
487 * and the directory, error code otherwise
488 */
489static int smack_inode_rmdir(struct inode *dir, struct dentry *dentry)
490{
491 int rc;
492
493 /*
494 * You need write access to the thing you're removing
495 */
496 rc = smk_curacc(smk_of_inode(dentry->d_inode), MAY_WRITE);
497 if (rc == 0)
498 /*
499 * You also need write access to the containing directory
500 */
501 rc = smk_curacc(smk_of_inode(dir), MAY_WRITE);
502
503 return rc;
504}
505
506/**
507 * smack_inode_rename - Smack check on rename
508 * @old_inode: the old directory
509 * @old_dentry: unused
510 * @new_inode: the new directory
511 * @new_dentry: unused
512 *
513 * Read and write access is required on both the old and
514 * new directories.
515 *
516 * Returns 0 if access is permitted, an error code otherwise
517 */
518static int smack_inode_rename(struct inode *old_inode,
519 struct dentry *old_dentry,
520 struct inode *new_inode,
521 struct dentry *new_dentry)
522{
523 int rc;
524 char *isp;
525
526 isp = smk_of_inode(old_dentry->d_inode);
527 rc = smk_curacc(isp, MAY_READWRITE);
528
529 if (rc == 0 && new_dentry->d_inode != NULL) {
530 isp = smk_of_inode(new_dentry->d_inode);
531 rc = smk_curacc(isp, MAY_READWRITE);
532 }
533
534 return rc;
535}
536
537/**
538 * smack_inode_permission - Smack version of permission()
539 * @inode: the inode in question
540 * @mask: the access requested
e114e473
CS
541 *
542 * This is the important Smack hook.
543 *
544 * Returns 0 if access is permitted, -EACCES otherwise
545 */
b77b0646 546static int smack_inode_permission(struct inode *inode, int mask)
e114e473
CS
547{
548 /*
549 * No permission to check. Existence test. Yup, it's there.
550 */
551 if (mask == 0)
552 return 0;
553
554 return smk_curacc(smk_of_inode(inode), mask);
555}
556
557/**
558 * smack_inode_setattr - Smack check for setting attributes
559 * @dentry: the object
560 * @iattr: for the force flag
561 *
562 * Returns 0 if access is permitted, an error code otherwise
563 */
564static int smack_inode_setattr(struct dentry *dentry, struct iattr *iattr)
565{
566 /*
567 * Need to allow for clearing the setuid bit.
568 */
569 if (iattr->ia_valid & ATTR_FORCE)
570 return 0;
571
572 return smk_curacc(smk_of_inode(dentry->d_inode), MAY_WRITE);
573}
574
575/**
576 * smack_inode_getattr - Smack check for getting attributes
577 * @mnt: unused
578 * @dentry: the object
579 *
580 * Returns 0 if access is permitted, an error code otherwise
581 */
582static int smack_inode_getattr(struct vfsmount *mnt, struct dentry *dentry)
583{
584 return smk_curacc(smk_of_inode(dentry->d_inode), MAY_READ);
585}
586
587/**
588 * smack_inode_setxattr - Smack check for setting xattrs
589 * @dentry: the object
590 * @name: name of the attribute
591 * @value: unused
592 * @size: unused
593 * @flags: unused
594 *
595 * This protects the Smack attribute explicitly.
596 *
597 * Returns 0 if access is permitted, an error code otherwise
598 */
8f0cfa52
DH
599static int smack_inode_setxattr(struct dentry *dentry, const char *name,
600 const void *value, size_t size, int flags)
e114e473 601{
bcdca225 602 int rc = 0;
e114e473 603
bcdca225
CS
604 if (strcmp(name, XATTR_NAME_SMACK) == 0 ||
605 strcmp(name, XATTR_NAME_SMACKIPIN) == 0 ||
606 strcmp(name, XATTR_NAME_SMACKIPOUT) == 0) {
607 if (!capable(CAP_MAC_ADMIN))
608 rc = -EPERM;
609 } else
610 rc = cap_inode_setxattr(dentry, name, value, size, flags);
611
612 if (rc == 0)
613 rc = smk_curacc(smk_of_inode(dentry->d_inode), MAY_WRITE);
614
615 return rc;
e114e473
CS
616}
617
618/**
619 * smack_inode_post_setxattr - Apply the Smack update approved above
620 * @dentry: object
621 * @name: attribute name
622 * @value: attribute value
623 * @size: attribute size
624 * @flags: unused
625 *
626 * Set the pointer in the inode blob to the entry found
627 * in the master label list.
628 */
8f0cfa52
DH
629static void smack_inode_post_setxattr(struct dentry *dentry, const char *name,
630 const void *value, size_t size, int flags)
e114e473
CS
631{
632 struct inode_smack *isp;
633 char *nsp;
634
635 /*
636 * Not SMACK
637 */
638 if (strcmp(name, XATTR_NAME_SMACK))
639 return;
640
641 if (size >= SMK_LABELLEN)
642 return;
643
644 isp = dentry->d_inode->i_security;
645
646 /*
647 * No locking is done here. This is a pointer
648 * assignment.
649 */
650 nsp = smk_import(value, size);
651 if (nsp != NULL)
652 isp->smk_inode = nsp;
653 else
654 isp->smk_inode = smack_known_invalid.smk_known;
655
656 return;
657}
658
659/*
660 * smack_inode_getxattr - Smack check on getxattr
661 * @dentry: the object
662 * @name: unused
663 *
664 * Returns 0 if access is permitted, an error code otherwise
665 */
8f0cfa52 666static int smack_inode_getxattr(struct dentry *dentry, const char *name)
e114e473
CS
667{
668 return smk_curacc(smk_of_inode(dentry->d_inode), MAY_READ);
669}
670
671/*
672 * smack_inode_removexattr - Smack check on removexattr
673 * @dentry: the object
674 * @name: name of the attribute
675 *
676 * Removing the Smack attribute requires CAP_MAC_ADMIN
677 *
678 * Returns 0 if access is permitted, an error code otherwise
679 */
8f0cfa52 680static int smack_inode_removexattr(struct dentry *dentry, const char *name)
e114e473 681{
bcdca225 682 int rc = 0;
e114e473 683
bcdca225
CS
684 if (strcmp(name, XATTR_NAME_SMACK) == 0 ||
685 strcmp(name, XATTR_NAME_SMACKIPIN) == 0 ||
686 strcmp(name, XATTR_NAME_SMACKIPOUT) == 0) {
687 if (!capable(CAP_MAC_ADMIN))
688 rc = -EPERM;
689 } else
690 rc = cap_inode_removexattr(dentry, name);
691
692 if (rc == 0)
693 rc = smk_curacc(smk_of_inode(dentry->d_inode), MAY_WRITE);
694
695 return rc;
e114e473
CS
696}
697
698/**
699 * smack_inode_getsecurity - get smack xattrs
700 * @inode: the object
701 * @name: attribute name
702 * @buffer: where to put the result
251a2a95 703 * @alloc: unused
e114e473
CS
704 *
705 * Returns the size of the attribute or an error code
706 */
707static int smack_inode_getsecurity(const struct inode *inode,
708 const char *name, void **buffer,
709 bool alloc)
710{
711 struct socket_smack *ssp;
712 struct socket *sock;
713 struct super_block *sbp;
714 struct inode *ip = (struct inode *)inode;
715 char *isp;
716 int ilen;
717 int rc = 0;
718
719 if (strcmp(name, XATTR_SMACK_SUFFIX) == 0) {
720 isp = smk_of_inode(inode);
721 ilen = strlen(isp) + 1;
722 *buffer = isp;
723 return ilen;
724 }
725
726 /*
727 * The rest of the Smack xattrs are only on sockets.
728 */
729 sbp = ip->i_sb;
730 if (sbp->s_magic != SOCKFS_MAGIC)
731 return -EOPNOTSUPP;
732
733 sock = SOCKET_I(ip);
2e1d146a 734 if (sock == NULL || sock->sk == NULL)
e114e473
CS
735 return -EOPNOTSUPP;
736
737 ssp = sock->sk->sk_security;
738
739 if (strcmp(name, XATTR_SMACK_IPIN) == 0)
740 isp = ssp->smk_in;
741 else if (strcmp(name, XATTR_SMACK_IPOUT) == 0)
742 isp = ssp->smk_out;
743 else
744 return -EOPNOTSUPP;
745
746 ilen = strlen(isp) + 1;
747 if (rc == 0) {
748 *buffer = isp;
749 rc = ilen;
750 }
751
752 return rc;
753}
754
755
756/**
757 * smack_inode_listsecurity - list the Smack attributes
758 * @inode: the object
759 * @buffer: where they go
760 * @buffer_size: size of buffer
761 *
762 * Returns 0 on success, -EINVAL otherwise
763 */
764static int smack_inode_listsecurity(struct inode *inode, char *buffer,
765 size_t buffer_size)
766{
767 int len = strlen(XATTR_NAME_SMACK);
768
769 if (buffer != NULL && len <= buffer_size) {
770 memcpy(buffer, XATTR_NAME_SMACK, len);
771 return len;
772 }
773 return -EINVAL;
774}
775
d20bdda6
AD
776/**
777 * smack_inode_getsecid - Extract inode's security id
778 * @inode: inode to extract the info from
779 * @secid: where result will be saved
780 */
781static void smack_inode_getsecid(const struct inode *inode, u32 *secid)
782{
783 struct inode_smack *isp = inode->i_security;
784
785 *secid = smack_to_secid(isp->smk_inode);
786}
787
e114e473
CS
788/*
789 * File Hooks
790 */
791
792/**
793 * smack_file_permission - Smack check on file operations
794 * @file: unused
795 * @mask: unused
796 *
797 * Returns 0
798 *
799 * Should access checks be done on each read or write?
800 * UNICOS and SELinux say yes.
801 * Trusted Solaris, Trusted Irix, and just about everyone else says no.
802 *
803 * I'll say no for now. Smack does not do the frequent
804 * label changing that SELinux does.
805 */
806static int smack_file_permission(struct file *file, int mask)
807{
808 return 0;
809}
810
811/**
812 * smack_file_alloc_security - assign a file security blob
813 * @file: the object
814 *
815 * The security blob for a file is a pointer to the master
816 * label list, so no allocation is done.
817 *
818 * Returns 0
819 */
820static int smack_file_alloc_security(struct file *file)
821{
86a264ab 822 file->f_security = current_security();
e114e473
CS
823 return 0;
824}
825
826/**
827 * smack_file_free_security - clear a file security blob
828 * @file: the object
829 *
830 * The security blob for a file is a pointer to the master
831 * label list, so no memory is freed.
832 */
833static void smack_file_free_security(struct file *file)
834{
835 file->f_security = NULL;
836}
837
838/**
839 * smack_file_ioctl - Smack check on ioctls
840 * @file: the object
841 * @cmd: what to do
842 * @arg: unused
843 *
844 * Relies heavily on the correct use of the ioctl command conventions.
845 *
846 * Returns 0 if allowed, error code otherwise
847 */
848static int smack_file_ioctl(struct file *file, unsigned int cmd,
849 unsigned long arg)
850{
851 int rc = 0;
852
853 if (_IOC_DIR(cmd) & _IOC_WRITE)
854 rc = smk_curacc(file->f_security, MAY_WRITE);
855
856 if (rc == 0 && (_IOC_DIR(cmd) & _IOC_READ))
857 rc = smk_curacc(file->f_security, MAY_READ);
858
859 return rc;
860}
861
862/**
863 * smack_file_lock - Smack check on file locking
864 * @file: the object
251a2a95 865 * @cmd: unused
e114e473
CS
866 *
867 * Returns 0 if current has write access, error code otherwise
868 */
869static int smack_file_lock(struct file *file, unsigned int cmd)
870{
871 return smk_curacc(file->f_security, MAY_WRITE);
872}
873
874/**
875 * smack_file_fcntl - Smack check on fcntl
876 * @file: the object
877 * @cmd: what action to check
878 * @arg: unused
879 *
880 * Returns 0 if current has access, error code otherwise
881 */
882static int smack_file_fcntl(struct file *file, unsigned int cmd,
883 unsigned long arg)
884{
885 int rc;
886
887 switch (cmd) {
888 case F_DUPFD:
889 case F_GETFD:
890 case F_GETFL:
891 case F_GETLK:
892 case F_GETOWN:
893 case F_GETSIG:
894 rc = smk_curacc(file->f_security, MAY_READ);
895 break;
896 case F_SETFD:
897 case F_SETFL:
898 case F_SETLK:
899 case F_SETLKW:
900 case F_SETOWN:
901 case F_SETSIG:
902 rc = smk_curacc(file->f_security, MAY_WRITE);
903 break;
904 default:
905 rc = smk_curacc(file->f_security, MAY_READWRITE);
906 }
907
908 return rc;
909}
910
911/**
912 * smack_file_set_fowner - set the file security blob value
913 * @file: object in question
914 *
915 * Returns 0
916 * Further research may be required on this one.
917 */
918static int smack_file_set_fowner(struct file *file)
919{
86a264ab 920 file->f_security = current_security();
e114e473
CS
921 return 0;
922}
923
924/**
925 * smack_file_send_sigiotask - Smack on sigio
926 * @tsk: The target task
927 * @fown: the object the signal come from
928 * @signum: unused
929 *
930 * Allow a privileged task to get signals even if it shouldn't
931 *
932 * Returns 0 if a subject with the object's smack could
933 * write to the task, an error code otherwise.
934 */
935static int smack_file_send_sigiotask(struct task_struct *tsk,
936 struct fown_struct *fown, int signum)
937{
938 struct file *file;
939 int rc;
940
941 /*
942 * struct fown_struct is never outside the context of a struct file
943 */
944 file = container_of(fown, struct file, f_owner);
b6dff3ec 945 rc = smk_access(file->f_security, tsk->cred->security, MAY_WRITE);
5cd9c58f 946 if (rc != 0 && has_capability(tsk, CAP_MAC_OVERRIDE))
e114e473
CS
947 return 0;
948 return rc;
949}
950
951/**
952 * smack_file_receive - Smack file receive check
953 * @file: the object
954 *
955 * Returns 0 if current has access, error code otherwise
956 */
957static int smack_file_receive(struct file *file)
958{
959 int may = 0;
960
961 /*
962 * This code relies on bitmasks.
963 */
964 if (file->f_mode & FMODE_READ)
965 may = MAY_READ;
966 if (file->f_mode & FMODE_WRITE)
967 may |= MAY_WRITE;
968
969 return smk_curacc(file->f_security, may);
970}
971
972/*
973 * Task hooks
974 */
975
e114e473 976/**
f1752eec
DH
977 * smack_cred_free - "free" task-level security credentials
978 * @cred: the credentials in question
e114e473
CS
979 *
980 * Smack isn't using copies of blobs. Everyone
981 * points to an immutable list. The blobs never go away.
982 * There is no leak here.
983 */
f1752eec 984static void smack_cred_free(struct cred *cred)
e114e473 985{
f1752eec 986 cred->security = NULL;
e114e473
CS
987}
988
d84f4f99
DH
989/**
990 * smack_cred_prepare - prepare new set of credentials for modification
991 * @new: the new credentials
992 * @old: the original credentials
993 * @gfp: the atomicity of any memory allocations
994 *
995 * Prepare a new set of credentials for modification.
996 */
997static int smack_cred_prepare(struct cred *new, const struct cred *old,
998 gfp_t gfp)
999{
1000 new->security = old->security;
1001 return 0;
1002}
1003
251a2a95
RD
1004/**
1005 * smack_cred_commit - commit new credentials
d84f4f99
DH
1006 * @new: the new credentials
1007 * @old: the original credentials
1008 */
1009static void smack_cred_commit(struct cred *new, const struct cred *old)
1010{
1011}
1012
3a3b7ce9
DH
1013/**
1014 * smack_kernel_act_as - Set the subjective context in a set of credentials
251a2a95
RD
1015 * @new: points to the set of credentials to be modified.
1016 * @secid: specifies the security ID to be set
3a3b7ce9
DH
1017 *
1018 * Set the security data for a kernel service.
1019 */
1020static int smack_kernel_act_as(struct cred *new, u32 secid)
1021{
1022 char *smack = smack_from_secid(secid);
1023
1024 if (smack == NULL)
1025 return -EINVAL;
1026
1027 new->security = smack;
1028 return 0;
1029}
1030
1031/**
1032 * smack_kernel_create_files_as - Set the file creation label in a set of creds
251a2a95
RD
1033 * @new: points to the set of credentials to be modified
1034 * @inode: points to the inode to use as a reference
3a3b7ce9
DH
1035 *
1036 * Set the file creation context in a set of credentials to the same
1037 * as the objective context of the specified inode
1038 */
1039static int smack_kernel_create_files_as(struct cred *new,
1040 struct inode *inode)
1041{
1042 struct inode_smack *isp = inode->i_security;
1043
1044 new->security = isp->smk_inode;
1045 return 0;
1046}
1047
e114e473
CS
1048/**
1049 * smack_task_setpgid - Smack check on setting pgid
1050 * @p: the task object
1051 * @pgid: unused
1052 *
1053 * Return 0 if write access is permitted
1054 */
1055static int smack_task_setpgid(struct task_struct *p, pid_t pgid)
1056{
c69e8d9c 1057 return smk_curacc(task_security(p), MAY_WRITE);
e114e473
CS
1058}
1059
1060/**
1061 * smack_task_getpgid - Smack access check for getpgid
1062 * @p: the object task
1063 *
1064 * Returns 0 if current can read the object task, error code otherwise
1065 */
1066static int smack_task_getpgid(struct task_struct *p)
1067{
c69e8d9c 1068 return smk_curacc(task_security(p), MAY_READ);
e114e473
CS
1069}
1070
1071/**
1072 * smack_task_getsid - Smack access check for getsid
1073 * @p: the object task
1074 *
1075 * Returns 0 if current can read the object task, error code otherwise
1076 */
1077static int smack_task_getsid(struct task_struct *p)
1078{
c69e8d9c 1079 return smk_curacc(task_security(p), MAY_READ);
e114e473
CS
1080}
1081
1082/**
1083 * smack_task_getsecid - get the secid of the task
1084 * @p: the object task
1085 * @secid: where to put the result
1086 *
1087 * Sets the secid to contain a u32 version of the smack label.
1088 */
1089static void smack_task_getsecid(struct task_struct *p, u32 *secid)
1090{
c69e8d9c 1091 *secid = smack_to_secid(task_security(p));
e114e473
CS
1092}
1093
1094/**
1095 * smack_task_setnice - Smack check on setting nice
1096 * @p: the task object
1097 * @nice: unused
1098 *
1099 * Return 0 if write access is permitted
1100 */
1101static int smack_task_setnice(struct task_struct *p, int nice)
1102{
bcdca225
CS
1103 int rc;
1104
1105 rc = cap_task_setnice(p, nice);
1106 if (rc == 0)
c69e8d9c 1107 rc = smk_curacc(task_security(p), MAY_WRITE);
bcdca225 1108 return rc;
e114e473
CS
1109}
1110
1111/**
1112 * smack_task_setioprio - Smack check on setting ioprio
1113 * @p: the task object
1114 * @ioprio: unused
1115 *
1116 * Return 0 if write access is permitted
1117 */
1118static int smack_task_setioprio(struct task_struct *p, int ioprio)
1119{
bcdca225
CS
1120 int rc;
1121
1122 rc = cap_task_setioprio(p, ioprio);
1123 if (rc == 0)
c69e8d9c 1124 rc = smk_curacc(task_security(p), MAY_WRITE);
bcdca225 1125 return rc;
e114e473
CS
1126}
1127
1128/**
1129 * smack_task_getioprio - Smack check on reading ioprio
1130 * @p: the task object
1131 *
1132 * Return 0 if read access is permitted
1133 */
1134static int smack_task_getioprio(struct task_struct *p)
1135{
c69e8d9c 1136 return smk_curacc(task_security(p), MAY_READ);
e114e473
CS
1137}
1138
1139/**
1140 * smack_task_setscheduler - Smack check on setting scheduler
1141 * @p: the task object
1142 * @policy: unused
1143 * @lp: unused
1144 *
1145 * Return 0 if read access is permitted
1146 */
1147static int smack_task_setscheduler(struct task_struct *p, int policy,
1148 struct sched_param *lp)
1149{
bcdca225
CS
1150 int rc;
1151
1152 rc = cap_task_setscheduler(p, policy, lp);
1153 if (rc == 0)
c69e8d9c 1154 rc = smk_curacc(task_security(p), MAY_WRITE);
bcdca225 1155 return rc;
e114e473
CS
1156}
1157
1158/**
1159 * smack_task_getscheduler - Smack check on reading scheduler
1160 * @p: the task object
1161 *
1162 * Return 0 if read access is permitted
1163 */
1164static int smack_task_getscheduler(struct task_struct *p)
1165{
c69e8d9c 1166 return smk_curacc(task_security(p), MAY_READ);
e114e473
CS
1167}
1168
1169/**
1170 * smack_task_movememory - Smack check on moving memory
1171 * @p: the task object
1172 *
1173 * Return 0 if write access is permitted
1174 */
1175static int smack_task_movememory(struct task_struct *p)
1176{
c69e8d9c 1177 return smk_curacc(task_security(p), MAY_WRITE);
e114e473
CS
1178}
1179
1180/**
1181 * smack_task_kill - Smack check on signal delivery
1182 * @p: the task object
1183 * @info: unused
1184 * @sig: unused
1185 * @secid: identifies the smack to use in lieu of current's
1186 *
1187 * Return 0 if write access is permitted
1188 *
1189 * The secid behavior is an artifact of an SELinux hack
1190 * in the USB code. Someday it may go away.
1191 */
1192static int smack_task_kill(struct task_struct *p, struct siginfo *info,
1193 int sig, u32 secid)
1194{
e114e473
CS
1195 /*
1196 * Sending a signal requires that the sender
1197 * can write the receiver.
1198 */
1199 if (secid == 0)
c69e8d9c 1200 return smk_curacc(task_security(p), MAY_WRITE);
e114e473
CS
1201 /*
1202 * If the secid isn't 0 we're dealing with some USB IO
1203 * specific behavior. This is not clean. For one thing
1204 * we can't take privilege into account.
1205 */
c69e8d9c 1206 return smk_access(smack_from_secid(secid), task_security(p), MAY_WRITE);
e114e473
CS
1207}
1208
1209/**
1210 * smack_task_wait - Smack access check for waiting
1211 * @p: task to wait for
1212 *
1213 * Returns 0 if current can wait for p, error code otherwise
1214 */
1215static int smack_task_wait(struct task_struct *p)
1216{
1217 int rc;
1218
c69e8d9c 1219 rc = smk_access(current_security(), task_security(p), MAY_WRITE);
e114e473
CS
1220 if (rc == 0)
1221 return 0;
1222
1223 /*
1224 * Allow the operation to succeed if either task
1225 * has privilege to perform operations that might
1226 * account for the smack labels having gotten to
1227 * be different in the first place.
1228 *
5cd9c58f 1229 * This breaks the strict subject/object access
e114e473
CS
1230 * control ideal, taking the object's privilege
1231 * state into account in the decision as well as
1232 * the smack value.
1233 */
5cd9c58f 1234 if (capable(CAP_MAC_OVERRIDE) || has_capability(p, CAP_MAC_OVERRIDE))
e114e473
CS
1235 return 0;
1236
1237 return rc;
1238}
1239
1240/**
1241 * smack_task_to_inode - copy task smack into the inode blob
1242 * @p: task to copy from
251a2a95 1243 * @inode: inode to copy to
e114e473
CS
1244 *
1245 * Sets the smack pointer in the inode security blob
1246 */
1247static void smack_task_to_inode(struct task_struct *p, struct inode *inode)
1248{
1249 struct inode_smack *isp = inode->i_security;
c69e8d9c 1250 isp->smk_inode = task_security(p);
e114e473
CS
1251}
1252
1253/*
1254 * Socket hooks.
1255 */
1256
1257/**
1258 * smack_sk_alloc_security - Allocate a socket blob
1259 * @sk: the socket
1260 * @family: unused
251a2a95 1261 * @gfp_flags: memory allocation flags
e114e473
CS
1262 *
1263 * Assign Smack pointers to current
1264 *
1265 * Returns 0 on success, -ENOMEM is there's no memory
1266 */
1267static int smack_sk_alloc_security(struct sock *sk, int family, gfp_t gfp_flags)
1268{
86a264ab 1269 char *csp = current_security();
e114e473
CS
1270 struct socket_smack *ssp;
1271
1272 ssp = kzalloc(sizeof(struct socket_smack), gfp_flags);
1273 if (ssp == NULL)
1274 return -ENOMEM;
1275
1276 ssp->smk_in = csp;
1277 ssp->smk_out = csp;
6d3dc07c 1278 ssp->smk_labeled = SMACK_CIPSO_SOCKET;
e114e473
CS
1279 ssp->smk_packet[0] = '\0';
1280
1281 sk->sk_security = ssp;
1282
1283 return 0;
1284}
1285
1286/**
1287 * smack_sk_free_security - Free a socket blob
1288 * @sk: the socket
1289 *
1290 * Clears the blob pointer
1291 */
1292static void smack_sk_free_security(struct sock *sk)
1293{
1294 kfree(sk->sk_security);
1295}
1296
1297/**
1298 * smack_set_catset - convert a capset to netlabel mls categories
1299 * @catset: the Smack categories
1300 * @sap: where to put the netlabel categories
1301 *
1302 * Allocates and fills attr.mls.cat
1303 */
1304static void smack_set_catset(char *catset, struct netlbl_lsm_secattr *sap)
1305{
1306 unsigned char *cp;
1307 unsigned char m;
1308 int cat;
1309 int rc;
1310 int byte;
1311
c60264c4 1312 if (!catset)
e114e473
CS
1313 return;
1314
1315 sap->flags |= NETLBL_SECATTR_MLS_CAT;
1316 sap->attr.mls.cat = netlbl_secattr_catmap_alloc(GFP_ATOMIC);
1317 sap->attr.mls.cat->startbit = 0;
1318
1319 for (cat = 1, cp = catset, byte = 0; byte < SMK_LABELLEN; cp++, byte++)
1320 for (m = 0x80; m != 0; m >>= 1, cat++) {
1321 if ((m & *cp) == 0)
1322 continue;
1323 rc = netlbl_secattr_catmap_setbit(sap->attr.mls.cat,
1324 cat, GFP_ATOMIC);
1325 }
1326}
1327
1328/**
1329 * smack_to_secattr - fill a secattr from a smack value
1330 * @smack: the smack value
1331 * @nlsp: where the result goes
1332 *
1333 * Casey says that CIPSO is good enough for now.
1334 * It can be used to effect.
1335 * It can also be abused to effect when necessary.
1336 * Appologies to the TSIG group in general and GW in particular.
1337 */
1338static void smack_to_secattr(char *smack, struct netlbl_lsm_secattr *nlsp)
1339{
1340 struct smack_cipso cipso;
1341 int rc;
1342
6d3dc07c
CS
1343 nlsp->domain = smack;
1344 nlsp->flags = NETLBL_SECATTR_DOMAIN | NETLBL_SECATTR_MLS_LVL;
e114e473 1345
6d3dc07c
CS
1346 rc = smack_to_cipso(smack, &cipso);
1347 if (rc == 0) {
1348 nlsp->attr.mls.lvl = cipso.smk_level;
1349 smack_set_catset(cipso.smk_catset, nlsp);
1350 } else {
1351 nlsp->attr.mls.lvl = smack_cipso_direct;
1352 smack_set_catset(smack, nlsp);
e114e473
CS
1353 }
1354}
1355
1356/**
1357 * smack_netlabel - Set the secattr on a socket
1358 * @sk: the socket
6d3dc07c 1359 * @labeled: socket label scheme
e114e473
CS
1360 *
1361 * Convert the outbound smack value (smk_out) to a
1362 * secattr and attach it to the socket.
1363 *
1364 * Returns 0 on success or an error code
1365 */
6d3dc07c 1366static int smack_netlabel(struct sock *sk, int labeled)
e114e473 1367{
2e1d146a 1368 struct socket_smack *ssp;
e114e473 1369 struct netlbl_lsm_secattr secattr;
6d3dc07c 1370 int rc = 0;
e114e473 1371
2e1d146a 1372 ssp = sk->sk_security;
6d3dc07c
CS
1373 /*
1374 * Usually the netlabel code will handle changing the
1375 * packet labeling based on the label.
1376 * The case of a single label host is different, because
1377 * a single label host should never get a labeled packet
1378 * even though the label is usually associated with a packet
1379 * label.
1380 */
1381 local_bh_disable();
1382 bh_lock_sock_nested(sk);
1383
1384 if (ssp->smk_out == smack_net_ambient ||
1385 labeled == SMACK_UNLABELED_SOCKET)
1386 netlbl_sock_delattr(sk);
1387 else {
1388 netlbl_secattr_init(&secattr);
1389 smack_to_secattr(ssp->smk_out, &secattr);
1390 rc = netlbl_sock_setattr(sk, &secattr);
1391 netlbl_secattr_destroy(&secattr);
1392 }
1393
1394 bh_unlock_sock(sk);
1395 local_bh_enable();
1396 /*
1397 * Remember the label scheme used so that it is not
1398 * necessary to do the netlabel setting if it has not
1399 * changed the next time through.
1400 *
1401 * The -EDESTADDRREQ case is an indication that there's
1402 * a single level host involved.
1403 */
1404 if (rc == 0)
1405 ssp->smk_labeled = labeled;
4bc87e62 1406
e114e473
CS
1407 return rc;
1408}
1409
1410/**
1411 * smack_inode_setsecurity - set smack xattrs
1412 * @inode: the object
1413 * @name: attribute name
1414 * @value: attribute value
1415 * @size: size of the attribute
1416 * @flags: unused
1417 *
1418 * Sets the named attribute in the appropriate blob
1419 *
1420 * Returns 0 on success, or an error code
1421 */
1422static int smack_inode_setsecurity(struct inode *inode, const char *name,
1423 const void *value, size_t size, int flags)
1424{
1425 char *sp;
1426 struct inode_smack *nsp = inode->i_security;
1427 struct socket_smack *ssp;
1428 struct socket *sock;
4bc87e62 1429 int rc = 0;
e114e473
CS
1430
1431 if (value == NULL || size > SMK_LABELLEN)
1432 return -EACCES;
1433
1434 sp = smk_import(value, size);
1435 if (sp == NULL)
1436 return -EINVAL;
1437
1438 if (strcmp(name, XATTR_SMACK_SUFFIX) == 0) {
1439 nsp->smk_inode = sp;
1440 return 0;
1441 }
1442 /*
1443 * The rest of the Smack xattrs are only on sockets.
1444 */
1445 if (inode->i_sb->s_magic != SOCKFS_MAGIC)
1446 return -EOPNOTSUPP;
1447
1448 sock = SOCKET_I(inode);
2e1d146a 1449 if (sock == NULL || sock->sk == NULL)
e114e473
CS
1450 return -EOPNOTSUPP;
1451
1452 ssp = sock->sk->sk_security;
1453
1454 if (strcmp(name, XATTR_SMACK_IPIN) == 0)
1455 ssp->smk_in = sp;
1456 else if (strcmp(name, XATTR_SMACK_IPOUT) == 0) {
1457 ssp->smk_out = sp;
6d3dc07c 1458 rc = smack_netlabel(sock->sk, SMACK_CIPSO_SOCKET);
4bc87e62
CS
1459 if (rc != 0)
1460 printk(KERN_WARNING "Smack: \"%s\" netlbl error %d.\n",
1461 __func__, -rc);
e114e473
CS
1462 } else
1463 return -EOPNOTSUPP;
1464
1465 return 0;
1466}
1467
1468/**
1469 * smack_socket_post_create - finish socket setup
1470 * @sock: the socket
1471 * @family: protocol family
1472 * @type: unused
1473 * @protocol: unused
1474 * @kern: unused
1475 *
1476 * Sets the netlabel information on the socket
1477 *
1478 * Returns 0 on success, and error code otherwise
1479 */
1480static int smack_socket_post_create(struct socket *sock, int family,
1481 int type, int protocol, int kern)
1482{
2e1d146a 1483 if (family != PF_INET || sock->sk == NULL)
e114e473
CS
1484 return 0;
1485 /*
1486 * Set the outbound netlbl.
1487 */
6d3dc07c
CS
1488 return smack_netlabel(sock->sk, SMACK_CIPSO_SOCKET);
1489}
1490
1491
1492/**
1493 * smack_host_label - check host based restrictions
1494 * @sip: the object end
1495 *
1496 * looks for host based access restrictions
1497 *
1498 * This version will only be appropriate for really small
211a40c0 1499 * sets of single label hosts.
6d3dc07c
CS
1500 *
1501 * Returns the label of the far end or NULL if it's not special.
1502 */
1503static char *smack_host_label(struct sockaddr_in *sip)
1504{
1505 struct smk_netlbladdr *snp;
6d3dc07c 1506 struct in_addr *siap = &sip->sin_addr;
6d3dc07c
CS
1507
1508 if (siap->s_addr == 0)
1509 return NULL;
1510
6d3dc07c 1511 for (snp = smack_netlbladdrs; snp != NULL; snp = snp->smk_next) {
6d3dc07c 1512 /*
211a40c0 1513 * we break after finding the first match because
1514 * the list is sorted from longest to shortest mask
1515 * so we have found the most specific match
6d3dc07c 1516 */
211a40c0 1517 if ((&snp->smk_host.sin_addr)->s_addr ==
1518 (siap->s_addr & (&snp->smk_mask)->s_addr)) {
6d3dc07c 1519 return snp->smk_label;
211a40c0 1520 }
6d3dc07c
CS
1521 }
1522
211a40c0 1523 return NULL;
6d3dc07c
CS
1524}
1525
1526/**
1527 * smack_socket_connect - connect access check
1528 * @sock: the socket
1529 * @sap: the other end
1530 * @addrlen: size of sap
1531 *
1532 * Verifies that a connection may be possible
1533 *
1534 * Returns 0 on success, and error code otherwise
1535 */
1536static int smack_socket_connect(struct socket *sock, struct sockaddr *sap,
1537 int addrlen)
1538{
1539 struct socket_smack *ssp = sock->sk->sk_security;
1540 char *hostsp;
1541 int rc;
1542
1543 if (sock->sk == NULL || sock->sk->sk_family != PF_INET)
1544 return 0;
1545
1546 if (addrlen < sizeof(struct sockaddr_in))
1547 return -EINVAL;
1548
1549 hostsp = smack_host_label((struct sockaddr_in *)sap);
1550 if (hostsp == NULL) {
1551 if (ssp->smk_labeled != SMACK_CIPSO_SOCKET)
1552 return smack_netlabel(sock->sk, SMACK_CIPSO_SOCKET);
1553 return 0;
1554 }
1555
1556 rc = smk_access(ssp->smk_out, hostsp, MAY_WRITE);
1557 if (rc != 0)
1558 return rc;
1559
1560 if (ssp->smk_labeled != SMACK_UNLABELED_SOCKET)
1561 return smack_netlabel(sock->sk, SMACK_UNLABELED_SOCKET);
1562 return 0;
e114e473
CS
1563}
1564
1565/**
1566 * smack_flags_to_may - convert S_ to MAY_ values
1567 * @flags: the S_ value
1568 *
1569 * Returns the equivalent MAY_ value
1570 */
1571static int smack_flags_to_may(int flags)
1572{
1573 int may = 0;
1574
1575 if (flags & S_IRUGO)
1576 may |= MAY_READ;
1577 if (flags & S_IWUGO)
1578 may |= MAY_WRITE;
1579 if (flags & S_IXUGO)
1580 may |= MAY_EXEC;
1581
1582 return may;
1583}
1584
1585/**
1586 * smack_msg_msg_alloc_security - Set the security blob for msg_msg
1587 * @msg: the object
1588 *
1589 * Returns 0
1590 */
1591static int smack_msg_msg_alloc_security(struct msg_msg *msg)
1592{
86a264ab 1593 msg->security = current_security();
e114e473
CS
1594 return 0;
1595}
1596
1597/**
1598 * smack_msg_msg_free_security - Clear the security blob for msg_msg
1599 * @msg: the object
1600 *
1601 * Clears the blob pointer
1602 */
1603static void smack_msg_msg_free_security(struct msg_msg *msg)
1604{
1605 msg->security = NULL;
1606}
1607
1608/**
1609 * smack_of_shm - the smack pointer for the shm
1610 * @shp: the object
1611 *
1612 * Returns a pointer to the smack value
1613 */
1614static char *smack_of_shm(struct shmid_kernel *shp)
1615{
1616 return (char *)shp->shm_perm.security;
1617}
1618
1619/**
1620 * smack_shm_alloc_security - Set the security blob for shm
1621 * @shp: the object
1622 *
1623 * Returns 0
1624 */
1625static int smack_shm_alloc_security(struct shmid_kernel *shp)
1626{
1627 struct kern_ipc_perm *isp = &shp->shm_perm;
1628
86a264ab 1629 isp->security = current_security();
e114e473
CS
1630 return 0;
1631}
1632
1633/**
1634 * smack_shm_free_security - Clear the security blob for shm
1635 * @shp: the object
1636 *
1637 * Clears the blob pointer
1638 */
1639static void smack_shm_free_security(struct shmid_kernel *shp)
1640{
1641 struct kern_ipc_perm *isp = &shp->shm_perm;
1642
1643 isp->security = NULL;
1644}
1645
1646/**
1647 * smack_shm_associate - Smack access check for shm
1648 * @shp: the object
1649 * @shmflg: access requested
1650 *
1651 * Returns 0 if current has the requested access, error code otherwise
1652 */
1653static int smack_shm_associate(struct shmid_kernel *shp, int shmflg)
1654{
1655 char *ssp = smack_of_shm(shp);
1656 int may;
1657
1658 may = smack_flags_to_may(shmflg);
1659 return smk_curacc(ssp, may);
1660}
1661
1662/**
1663 * smack_shm_shmctl - Smack access check for shm
1664 * @shp: the object
1665 * @cmd: what it wants to do
1666 *
1667 * Returns 0 if current has the requested access, error code otherwise
1668 */
1669static int smack_shm_shmctl(struct shmid_kernel *shp, int cmd)
1670{
1d252fb8 1671 char *ssp;
e114e473
CS
1672 int may;
1673
1674 switch (cmd) {
1675 case IPC_STAT:
1676 case SHM_STAT:
1677 may = MAY_READ;
1678 break;
1679 case IPC_SET:
1680 case SHM_LOCK:
1681 case SHM_UNLOCK:
1682 case IPC_RMID:
1683 may = MAY_READWRITE;
1684 break;
1685 case IPC_INFO:
1686 case SHM_INFO:
1687 /*
1688 * System level information.
1689 */
1690 return 0;
1691 default:
1692 return -EINVAL;
1693 }
1694
1d252fb8 1695 ssp = smack_of_shm(shp);
e114e473
CS
1696 return smk_curacc(ssp, may);
1697}
1698
1699/**
1700 * smack_shm_shmat - Smack access for shmat
1701 * @shp: the object
1702 * @shmaddr: unused
1703 * @shmflg: access requested
1704 *
1705 * Returns 0 if current has the requested access, error code otherwise
1706 */
1707static int smack_shm_shmat(struct shmid_kernel *shp, char __user *shmaddr,
1708 int shmflg)
1709{
1710 char *ssp = smack_of_shm(shp);
1711 int may;
1712
1713 may = smack_flags_to_may(shmflg);
1714 return smk_curacc(ssp, may);
1715}
1716
1717/**
1718 * smack_of_sem - the smack pointer for the sem
1719 * @sma: the object
1720 *
1721 * Returns a pointer to the smack value
1722 */
1723static char *smack_of_sem(struct sem_array *sma)
1724{
1725 return (char *)sma->sem_perm.security;
1726}
1727
1728/**
1729 * smack_sem_alloc_security - Set the security blob for sem
1730 * @sma: the object
1731 *
1732 * Returns 0
1733 */
1734static int smack_sem_alloc_security(struct sem_array *sma)
1735{
1736 struct kern_ipc_perm *isp = &sma->sem_perm;
1737
86a264ab 1738 isp->security = current_security();
e114e473
CS
1739 return 0;
1740}
1741
1742/**
1743 * smack_sem_free_security - Clear the security blob for sem
1744 * @sma: the object
1745 *
1746 * Clears the blob pointer
1747 */
1748static void smack_sem_free_security(struct sem_array *sma)
1749{
1750 struct kern_ipc_perm *isp = &sma->sem_perm;
1751
1752 isp->security = NULL;
1753}
1754
1755/**
1756 * smack_sem_associate - Smack access check for sem
1757 * @sma: the object
1758 * @semflg: access requested
1759 *
1760 * Returns 0 if current has the requested access, error code otherwise
1761 */
1762static int smack_sem_associate(struct sem_array *sma, int semflg)
1763{
1764 char *ssp = smack_of_sem(sma);
1765 int may;
1766
1767 may = smack_flags_to_may(semflg);
1768 return smk_curacc(ssp, may);
1769}
1770
1771/**
1772 * smack_sem_shmctl - Smack access check for sem
1773 * @sma: the object
1774 * @cmd: what it wants to do
1775 *
1776 * Returns 0 if current has the requested access, error code otherwise
1777 */
1778static int smack_sem_semctl(struct sem_array *sma, int cmd)
1779{
1d252fb8 1780 char *ssp;
e114e473
CS
1781 int may;
1782
1783 switch (cmd) {
1784 case GETPID:
1785 case GETNCNT:
1786 case GETZCNT:
1787 case GETVAL:
1788 case GETALL:
1789 case IPC_STAT:
1790 case SEM_STAT:
1791 may = MAY_READ;
1792 break;
1793 case SETVAL:
1794 case SETALL:
1795 case IPC_RMID:
1796 case IPC_SET:
1797 may = MAY_READWRITE;
1798 break;
1799 case IPC_INFO:
1800 case SEM_INFO:
1801 /*
1802 * System level information
1803 */
1804 return 0;
1805 default:
1806 return -EINVAL;
1807 }
1808
1d252fb8 1809 ssp = smack_of_sem(sma);
e114e473
CS
1810 return smk_curacc(ssp, may);
1811}
1812
1813/**
1814 * smack_sem_semop - Smack checks of semaphore operations
1815 * @sma: the object
1816 * @sops: unused
1817 * @nsops: unused
1818 * @alter: unused
1819 *
1820 * Treated as read and write in all cases.
1821 *
1822 * Returns 0 if access is allowed, error code otherwise
1823 */
1824static int smack_sem_semop(struct sem_array *sma, struct sembuf *sops,
1825 unsigned nsops, int alter)
1826{
1827 char *ssp = smack_of_sem(sma);
1828
1829 return smk_curacc(ssp, MAY_READWRITE);
1830}
1831
1832/**
1833 * smack_msg_alloc_security - Set the security blob for msg
1834 * @msq: the object
1835 *
1836 * Returns 0
1837 */
1838static int smack_msg_queue_alloc_security(struct msg_queue *msq)
1839{
1840 struct kern_ipc_perm *kisp = &msq->q_perm;
1841
86a264ab 1842 kisp->security = current_security();
e114e473
CS
1843 return 0;
1844}
1845
1846/**
1847 * smack_msg_free_security - Clear the security blob for msg
1848 * @msq: the object
1849 *
1850 * Clears the blob pointer
1851 */
1852static void smack_msg_queue_free_security(struct msg_queue *msq)
1853{
1854 struct kern_ipc_perm *kisp = &msq->q_perm;
1855
1856 kisp->security = NULL;
1857}
1858
1859/**
1860 * smack_of_msq - the smack pointer for the msq
1861 * @msq: the object
1862 *
1863 * Returns a pointer to the smack value
1864 */
1865static char *smack_of_msq(struct msg_queue *msq)
1866{
1867 return (char *)msq->q_perm.security;
1868}
1869
1870/**
1871 * smack_msg_queue_associate - Smack access check for msg_queue
1872 * @msq: the object
1873 * @msqflg: access requested
1874 *
1875 * Returns 0 if current has the requested access, error code otherwise
1876 */
1877static int smack_msg_queue_associate(struct msg_queue *msq, int msqflg)
1878{
1879 char *msp = smack_of_msq(msq);
1880 int may;
1881
1882 may = smack_flags_to_may(msqflg);
1883 return smk_curacc(msp, may);
1884}
1885
1886/**
1887 * smack_msg_queue_msgctl - Smack access check for msg_queue
1888 * @msq: the object
1889 * @cmd: what it wants to do
1890 *
1891 * Returns 0 if current has the requested access, error code otherwise
1892 */
1893static int smack_msg_queue_msgctl(struct msg_queue *msq, int cmd)
1894{
1d252fb8 1895 char *msp;
e114e473
CS
1896 int may;
1897
1898 switch (cmd) {
1899 case IPC_STAT:
1900 case MSG_STAT:
1901 may = MAY_READ;
1902 break;
1903 case IPC_SET:
1904 case IPC_RMID:
1905 may = MAY_READWRITE;
1906 break;
1907 case IPC_INFO:
1908 case MSG_INFO:
1909 /*
1910 * System level information
1911 */
1912 return 0;
1913 default:
1914 return -EINVAL;
1915 }
1916
1d252fb8 1917 msp = smack_of_msq(msq);
e114e473
CS
1918 return smk_curacc(msp, may);
1919}
1920
1921/**
1922 * smack_msg_queue_msgsnd - Smack access check for msg_queue
1923 * @msq: the object
1924 * @msg: unused
1925 * @msqflg: access requested
1926 *
1927 * Returns 0 if current has the requested access, error code otherwise
1928 */
1929static int smack_msg_queue_msgsnd(struct msg_queue *msq, struct msg_msg *msg,
1930 int msqflg)
1931{
1932 char *msp = smack_of_msq(msq);
1933 int rc;
1934
1935 rc = smack_flags_to_may(msqflg);
1936 return smk_curacc(msp, rc);
1937}
1938
1939/**
1940 * smack_msg_queue_msgsnd - Smack access check for msg_queue
1941 * @msq: the object
1942 * @msg: unused
1943 * @target: unused
1944 * @type: unused
1945 * @mode: unused
1946 *
1947 * Returns 0 if current has read and write access, error code otherwise
1948 */
1949static int smack_msg_queue_msgrcv(struct msg_queue *msq, struct msg_msg *msg,
1950 struct task_struct *target, long type, int mode)
1951{
1952 char *msp = smack_of_msq(msq);
1953
1954 return smk_curacc(msp, MAY_READWRITE);
1955}
1956
1957/**
1958 * smack_ipc_permission - Smack access for ipc_permission()
1959 * @ipp: the object permissions
1960 * @flag: access requested
1961 *
1962 * Returns 0 if current has read and write access, error code otherwise
1963 */
1964static int smack_ipc_permission(struct kern_ipc_perm *ipp, short flag)
1965{
1966 char *isp = ipp->security;
1967 int may;
1968
1969 may = smack_flags_to_may(flag);
1970 return smk_curacc(isp, may);
1971}
1972
d20bdda6
AD
1973/**
1974 * smack_ipc_getsecid - Extract smack security id
251a2a95 1975 * @ipp: the object permissions
d20bdda6
AD
1976 * @secid: where result will be saved
1977 */
1978static void smack_ipc_getsecid(struct kern_ipc_perm *ipp, u32 *secid)
1979{
1980 char *smack = ipp->security;
1981
1982 *secid = smack_to_secid(smack);
1983}
1984
e114e473
CS
1985/**
1986 * smack_d_instantiate - Make sure the blob is correct on an inode
1987 * @opt_dentry: unused
1988 * @inode: the object
1989 *
1990 * Set the inode's security blob if it hasn't been done already.
1991 */
1992static void smack_d_instantiate(struct dentry *opt_dentry, struct inode *inode)
1993{
1994 struct super_block *sbp;
1995 struct superblock_smack *sbsp;
1996 struct inode_smack *isp;
86a264ab 1997 char *csp = current_security();
e114e473
CS
1998 char *fetched;
1999 char *final;
2000 struct dentry *dp;
2001
2002 if (inode == NULL)
2003 return;
2004
2005 isp = inode->i_security;
2006
2007 mutex_lock(&isp->smk_lock);
2008 /*
2009 * If the inode is already instantiated
2010 * take the quick way out
2011 */
2012 if (isp->smk_flags & SMK_INODE_INSTANT)
2013 goto unlockandout;
2014
2015 sbp = inode->i_sb;
2016 sbsp = sbp->s_security;
2017 /*
2018 * We're going to use the superblock default label
2019 * if there's no label on the file.
2020 */
2021 final = sbsp->smk_default;
2022
e97dcb0e
CS
2023 /*
2024 * If this is the root inode the superblock
2025 * may be in the process of initialization.
2026 * If that is the case use the root value out
2027 * of the superblock.
2028 */
2029 if (opt_dentry->d_parent == opt_dentry) {
2030 isp->smk_inode = sbsp->smk_root;
2031 isp->smk_flags |= SMK_INODE_INSTANT;
2032 goto unlockandout;
2033 }
2034
e114e473
CS
2035 /*
2036 * This is pretty hackish.
2037 * Casey says that we shouldn't have to do
2038 * file system specific code, but it does help
2039 * with keeping it simple.
2040 */
2041 switch (sbp->s_magic) {
2042 case SMACK_MAGIC:
2043 /*
2044 * Casey says that it's a little embarassing
2045 * that the smack file system doesn't do
2046 * extended attributes.
2047 */
2048 final = smack_known_star.smk_known;
2049 break;
2050 case PIPEFS_MAGIC:
2051 /*
2052 * Casey says pipes are easy (?)
2053 */
2054 final = smack_known_star.smk_known;
2055 break;
2056 case DEVPTS_SUPER_MAGIC:
2057 /*
2058 * devpts seems content with the label of the task.
2059 * Programs that change smack have to treat the
2060 * pty with respect.
2061 */
2062 final = csp;
2063 break;
2064 case SOCKFS_MAGIC:
2065 /*
2066 * Casey says sockets get the smack of the task.
2067 */
2068 final = csp;
2069 break;
2070 case PROC_SUPER_MAGIC:
2071 /*
2072 * Casey says procfs appears not to care.
2073 * The superblock default suffices.
2074 */
2075 break;
2076 case TMPFS_MAGIC:
2077 /*
2078 * Device labels should come from the filesystem,
2079 * but watch out, because they're volitile,
2080 * getting recreated on every reboot.
2081 */
2082 final = smack_known_star.smk_known;
2083 /*
2084 * No break.
2085 *
2086 * If a smack value has been set we want to use it,
2087 * but since tmpfs isn't giving us the opportunity
2088 * to set mount options simulate setting the
2089 * superblock default.
2090 */
2091 default:
2092 /*
2093 * This isn't an understood special case.
2094 * Get the value from the xattr.
2095 *
2096 * No xattr support means, alas, no SMACK label.
2097 * Use the aforeapplied default.
2098 * It would be curious if the label of the task
2099 * does not match that assigned.
2100 */
2101 if (inode->i_op->getxattr == NULL)
2102 break;
2103 /*
2104 * Get the dentry for xattr.
2105 */
2106 if (opt_dentry == NULL) {
2107 dp = d_find_alias(inode);
2108 if (dp == NULL)
2109 break;
2110 } else {
2111 dp = dget(opt_dentry);
2112 if (dp == NULL)
2113 break;
2114 }
2115
2116 fetched = smk_fetch(inode, dp);
2117 if (fetched != NULL)
2118 final = fetched;
2119
2120 dput(dp);
2121 break;
2122 }
2123
2124 if (final == NULL)
2125 isp->smk_inode = csp;
2126 else
2127 isp->smk_inode = final;
2128
2129 isp->smk_flags |= SMK_INODE_INSTANT;
2130
2131unlockandout:
2132 mutex_unlock(&isp->smk_lock);
2133 return;
2134}
2135
2136/**
2137 * smack_getprocattr - Smack process attribute access
2138 * @p: the object task
2139 * @name: the name of the attribute in /proc/.../attr
2140 * @value: where to put the result
2141 *
2142 * Places a copy of the task Smack into value
2143 *
2144 * Returns the length of the smack label or an error code
2145 */
2146static int smack_getprocattr(struct task_struct *p, char *name, char **value)
2147{
2148 char *cp;
2149 int slen;
2150
2151 if (strcmp(name, "current") != 0)
2152 return -EINVAL;
2153
c69e8d9c 2154 cp = kstrdup(task_security(p), GFP_KERNEL);
e114e473
CS
2155 if (cp == NULL)
2156 return -ENOMEM;
2157
2158 slen = strlen(cp);
2159 *value = cp;
2160 return slen;
2161}
2162
2163/**
2164 * smack_setprocattr - Smack process attribute setting
2165 * @p: the object task
2166 * @name: the name of the attribute in /proc/.../attr
2167 * @value: the value to set
2168 * @size: the size of the value
2169 *
2170 * Sets the Smack value of the task. Only setting self
2171 * is permitted and only with privilege
2172 *
2173 * Returns the length of the smack label or an error code
2174 */
2175static int smack_setprocattr(struct task_struct *p, char *name,
2176 void *value, size_t size)
2177{
d84f4f99 2178 struct cred *new;
e114e473
CS
2179 char *newsmack;
2180
e114e473
CS
2181 /*
2182 * Changing another process' Smack value is too dangerous
2183 * and supports no sane use case.
2184 */
2185 if (p != current)
2186 return -EPERM;
2187
5cd9c58f
DH
2188 if (!capable(CAP_MAC_ADMIN))
2189 return -EPERM;
2190
e114e473
CS
2191 if (value == NULL || size == 0 || size >= SMK_LABELLEN)
2192 return -EINVAL;
2193
2194 if (strcmp(name, "current") != 0)
2195 return -EINVAL;
2196
2197 newsmack = smk_import(value, size);
2198 if (newsmack == NULL)
2199 return -EINVAL;
2200
6d3dc07c
CS
2201 /*
2202 * No process is ever allowed the web ("@") label.
2203 */
2204 if (newsmack == smack_known_web.smk_known)
2205 return -EPERM;
2206
d84f4f99 2207 new = prepare_creds();
6d3dc07c 2208 if (new == NULL)
d84f4f99
DH
2209 return -ENOMEM;
2210 new->security = newsmack;
2211 commit_creds(new);
e114e473
CS
2212 return size;
2213}
2214
2215/**
2216 * smack_unix_stream_connect - Smack access on UDS
2217 * @sock: one socket
2218 * @other: the other socket
2219 * @newsk: unused
2220 *
2221 * Return 0 if a subject with the smack of sock could access
2222 * an object with the smack of other, otherwise an error code
2223 */
2224static int smack_unix_stream_connect(struct socket *sock,
2225 struct socket *other, struct sock *newsk)
2226{
2227 struct inode *sp = SOCK_INODE(sock);
2228 struct inode *op = SOCK_INODE(other);
2229
2230 return smk_access(smk_of_inode(sp), smk_of_inode(op), MAY_READWRITE);
2231}
2232
2233/**
2234 * smack_unix_may_send - Smack access on UDS
2235 * @sock: one socket
2236 * @other: the other socket
2237 *
2238 * Return 0 if a subject with the smack of sock could access
2239 * an object with the smack of other, otherwise an error code
2240 */
2241static int smack_unix_may_send(struct socket *sock, struct socket *other)
2242{
2243 struct inode *sp = SOCK_INODE(sock);
2244 struct inode *op = SOCK_INODE(other);
2245
2246 return smk_access(smk_of_inode(sp), smk_of_inode(op), MAY_WRITE);
2247}
2248
6d3dc07c
CS
2249/**
2250 * smack_socket_sendmsg - Smack check based on destination host
2251 * @sock: the socket
251a2a95 2252 * @msg: the message
6d3dc07c
CS
2253 * @size: the size of the message
2254 *
2255 * Return 0 if the current subject can write to the destination
2256 * host. This is only a question if the destination is a single
2257 * label host.
2258 */
2259static int smack_socket_sendmsg(struct socket *sock, struct msghdr *msg,
2260 int size)
2261{
2262 struct sockaddr_in *sip = (struct sockaddr_in *) msg->msg_name;
2263 struct socket_smack *ssp = sock->sk->sk_security;
2264 char *hostsp;
2265 int rc;
2266
2267 /*
2268 * Perfectly reasonable for this to be NULL
2269 */
2270 if (sip == NULL || sip->sin_family != PF_INET)
2271 return 0;
2272
2273 hostsp = smack_host_label(sip);
2274 if (hostsp == NULL) {
2275 if (ssp->smk_labeled != SMACK_CIPSO_SOCKET)
2276 return smack_netlabel(sock->sk, SMACK_CIPSO_SOCKET);
2277 return 0;
2278 }
2279
2280 rc = smk_access(ssp->smk_out, hostsp, MAY_WRITE);
2281 if (rc != 0)
2282 return rc;
2283
2284 if (ssp->smk_labeled != SMACK_UNLABELED_SOCKET)
2285 return smack_netlabel(sock->sk, SMACK_UNLABELED_SOCKET);
2286
2287 return 0;
2288
2289}
2290
2291
e114e473 2292/**
251a2a95 2293 * smack_from_secattr - Convert a netlabel attr.mls.lvl/attr.mls.cat pair to smack
e114e473
CS
2294 * @sap: netlabel secattr
2295 * @sip: where to put the result
2296 *
2297 * Copies a smack label into sip
2298 */
2299static void smack_from_secattr(struct netlbl_lsm_secattr *sap, char *sip)
2300{
2301 char smack[SMK_LABELLEN];
6d3dc07c 2302 char *sp;
e114e473
CS
2303 int pcat;
2304
6d3dc07c 2305 if ((sap->flags & NETLBL_SECATTR_MLS_LVL) != 0) {
e114e473 2306 /*
6d3dc07c 2307 * Looks like a CIPSO packet.
e114e473
CS
2308 * If there are flags but no level netlabel isn't
2309 * behaving the way we expect it to.
2310 *
6d3dc07c 2311 * Get the categories, if any
e114e473
CS
2312 * Without guidance regarding the smack value
2313 * for the packet fall back on the network
2314 * ambient value.
2315 */
6d3dc07c
CS
2316 memset(smack, '\0', SMK_LABELLEN);
2317 if ((sap->flags & NETLBL_SECATTR_MLS_CAT) != 0)
2318 for (pcat = -1;;) {
2319 pcat = netlbl_secattr_catmap_walk(
2320 sap->attr.mls.cat, pcat + 1);
2321 if (pcat < 0)
2322 break;
2323 smack_catset_bit(pcat, smack);
2324 }
2325 /*
2326 * If it is CIPSO using smack direct mapping
2327 * we are already done. WeeHee.
2328 */
2329 if (sap->attr.mls.lvl == smack_cipso_direct) {
2330 memcpy(sip, smack, SMK_MAXLEN);
2331 return;
2332 }
2333 /*
2334 * Look it up in the supplied table if it is not
2335 * a direct mapping.
2336 */
2337 smack_from_cipso(sap->attr.mls.lvl, smack, sip);
e114e473
CS
2338 return;
2339 }
6d3dc07c
CS
2340 if ((sap->flags & NETLBL_SECATTR_SECID) != 0) {
2341 /*
2342 * Looks like a fallback, which gives us a secid.
2343 */
2344 sp = smack_from_secid(sap->attr.secid);
2345 /*
2346 * This has got to be a bug because it is
2347 * impossible to specify a fallback without
2348 * specifying the label, which will ensure
2349 * it has a secid, and the only way to get a
2350 * secid is from a fallback.
2351 */
2352 BUG_ON(sp == NULL);
2353 strncpy(sip, sp, SMK_MAXLEN);
e114e473
CS
2354 return;
2355 }
2356 /*
6d3dc07c
CS
2357 * Without guidance regarding the smack value
2358 * for the packet fall back on the network
2359 * ambient value.
e114e473 2360 */
6d3dc07c 2361 strncpy(sip, smack_net_ambient, SMK_MAXLEN);
e114e473
CS
2362 return;
2363}
2364
2365/**
2366 * smack_socket_sock_rcv_skb - Smack packet delivery access check
2367 * @sk: socket
2368 * @skb: packet
2369 *
2370 * Returns 0 if the packet should be delivered, an error code otherwise
2371 */
2372static int smack_socket_sock_rcv_skb(struct sock *sk, struct sk_buff *skb)
2373{
2374 struct netlbl_lsm_secattr secattr;
2375 struct socket_smack *ssp = sk->sk_security;
2376 char smack[SMK_LABELLEN];
6d3dc07c 2377 char *csp;
e114e473
CS
2378 int rc;
2379
2380 if (sk->sk_family != PF_INET && sk->sk_family != PF_INET6)
2381 return 0;
2382
2383 /*
2384 * Translate what netlabel gave us.
2385 */
e114e473 2386 netlbl_secattr_init(&secattr);
6d3dc07c 2387
e114e473 2388 rc = netlbl_skbuff_getattr(skb, sk->sk_family, &secattr);
6d3dc07c 2389 if (rc == 0) {
e114e473 2390 smack_from_secattr(&secattr, smack);
6d3dc07c
CS
2391 csp = smack;
2392 } else
2393 csp = smack_net_ambient;
2394
e114e473 2395 netlbl_secattr_destroy(&secattr);
6d3dc07c 2396
e114e473
CS
2397 /*
2398 * Receiving a packet requires that the other end
2399 * be able to write here. Read access is not required.
2400 * This is the simplist possible security model
2401 * for networking.
2402 */
6d3dc07c 2403 rc = smk_access(csp, ssp->smk_in, MAY_WRITE);
a8134296
PM
2404 if (rc != 0)
2405 netlbl_skbuff_err(skb, rc, 0);
2406 return rc;
e114e473
CS
2407}
2408
2409/**
2410 * smack_socket_getpeersec_stream - pull in packet label
2411 * @sock: the socket
2412 * @optval: user's destination
2413 * @optlen: size thereof
251a2a95 2414 * @len: max thereof
e114e473
CS
2415 *
2416 * returns zero on success, an error code otherwise
2417 */
2418static int smack_socket_getpeersec_stream(struct socket *sock,
2419 char __user *optval,
2420 int __user *optlen, unsigned len)
2421{
2422 struct socket_smack *ssp;
2423 int slen;
2424 int rc = 0;
2425
2426 ssp = sock->sk->sk_security;
2427 slen = strlen(ssp->smk_packet) + 1;
2428
2429 if (slen > len)
2430 rc = -ERANGE;
2431 else if (copy_to_user(optval, ssp->smk_packet, slen) != 0)
2432 rc = -EFAULT;
2433
2434 if (put_user(slen, optlen) != 0)
2435 rc = -EFAULT;
2436
2437 return rc;
2438}
2439
2440
2441/**
2442 * smack_socket_getpeersec_dgram - pull in packet label
2443 * @sock: the socket
2444 * @skb: packet data
2445 * @secid: pointer to where to put the secid of the packet
2446 *
2447 * Sets the netlabel socket state on sk from parent
2448 */
2449static int smack_socket_getpeersec_dgram(struct socket *sock,
2450 struct sk_buff *skb, u32 *secid)
2451
2452{
2453 struct netlbl_lsm_secattr secattr;
2454 struct sock *sk;
2455 char smack[SMK_LABELLEN];
2456 int family = PF_INET;
2457 u32 s;
2458 int rc;
2459
2460 /*
2461 * Only works for families with packets.
2462 */
2463 if (sock != NULL) {
2464 sk = sock->sk;
2465 if (sk->sk_family != PF_INET && sk->sk_family != PF_INET6)
2466 return 0;
2467 family = sk->sk_family;
2468 }
2469 /*
2470 * Translate what netlabel gave us.
2471 */
e114e473
CS
2472 netlbl_secattr_init(&secattr);
2473 rc = netlbl_skbuff_getattr(skb, family, &secattr);
2474 if (rc == 0)
2475 smack_from_secattr(&secattr, smack);
2476 netlbl_secattr_destroy(&secattr);
2477
2478 /*
2479 * Give up if we couldn't get anything
2480 */
2481 if (rc != 0)
2482 return rc;
2483
2484 s = smack_to_secid(smack);
2485 if (s == 0)
2486 return -EINVAL;
2487
2488 *secid = s;
2489 return 0;
2490}
2491
2492/**
2493 * smack_sock_graft - graft access state between two sockets
2494 * @sk: fresh sock
2495 * @parent: donor socket
2496 *
2497 * Sets the netlabel socket state on sk from parent
2498 */
2499static void smack_sock_graft(struct sock *sk, struct socket *parent)
2500{
2501 struct socket_smack *ssp;
2502 int rc;
2503
2504 if (sk == NULL)
2505 return;
2506
2507 if (sk->sk_family != PF_INET && sk->sk_family != PF_INET6)
2508 return;
2509
2510 ssp = sk->sk_security;
86a264ab 2511 ssp->smk_in = ssp->smk_out = current_security();
e114e473
CS
2512 ssp->smk_packet[0] = '\0';
2513
6d3dc07c 2514 rc = smack_netlabel(sk, SMACK_CIPSO_SOCKET);
4bc87e62
CS
2515 if (rc != 0)
2516 printk(KERN_WARNING "Smack: \"%s\" netlbl error %d.\n",
2517 __func__, -rc);
e114e473
CS
2518}
2519
2520/**
2521 * smack_inet_conn_request - Smack access check on connect
2522 * @sk: socket involved
2523 * @skb: packet
2524 * @req: unused
2525 *
2526 * Returns 0 if a task with the packet label could write to
2527 * the socket, otherwise an error code
2528 */
2529static int smack_inet_conn_request(struct sock *sk, struct sk_buff *skb,
2530 struct request_sock *req)
2531{
2532 struct netlbl_lsm_secattr skb_secattr;
2533 struct socket_smack *ssp = sk->sk_security;
2534 char smack[SMK_LABELLEN];
2535 int rc;
2536
2537 if (skb == NULL)
2538 return -EACCES;
2539
e114e473
CS
2540 netlbl_secattr_init(&skb_secattr);
2541 rc = netlbl_skbuff_getattr(skb, sk->sk_family, &skb_secattr);
2542 if (rc == 0)
2543 smack_from_secattr(&skb_secattr, smack);
2544 else
2545 strncpy(smack, smack_known_huh.smk_known, SMK_MAXLEN);
2546 netlbl_secattr_destroy(&skb_secattr);
2547 /*
2548 * Receiving a packet requires that the other end
2549 * be able to write here. Read access is not required.
2550 *
2551 * If the request is successful save the peer's label
2552 * so that SO_PEERCRED can report it.
2553 */
2554 rc = smk_access(smack, ssp->smk_in, MAY_WRITE);
2555 if (rc == 0)
2556 strncpy(ssp->smk_packet, smack, SMK_MAXLEN);
2557
2558 return rc;
2559}
2560
2561/*
2562 * Key management security hooks
2563 *
2564 * Casey has not tested key support very heavily.
2565 * The permission check is most likely too restrictive.
2566 * If you care about keys please have a look.
2567 */
2568#ifdef CONFIG_KEYS
2569
2570/**
2571 * smack_key_alloc - Set the key security blob
2572 * @key: object
d84f4f99 2573 * @cred: the credentials to use
e114e473
CS
2574 * @flags: unused
2575 *
2576 * No allocation required
2577 *
2578 * Returns 0
2579 */
d84f4f99 2580static int smack_key_alloc(struct key *key, const struct cred *cred,
e114e473
CS
2581 unsigned long flags)
2582{
d84f4f99 2583 key->security = cred->security;
e114e473
CS
2584 return 0;
2585}
2586
2587/**
2588 * smack_key_free - Clear the key security blob
2589 * @key: the object
2590 *
2591 * Clear the blob pointer
2592 */
2593static void smack_key_free(struct key *key)
2594{
2595 key->security = NULL;
2596}
2597
2598/*
2599 * smack_key_permission - Smack access on a key
2600 * @key_ref: gets to the object
d84f4f99 2601 * @cred: the credentials to use
e114e473
CS
2602 * @perm: unused
2603 *
2604 * Return 0 if the task has read and write to the object,
2605 * an error code otherwise
2606 */
2607static int smack_key_permission(key_ref_t key_ref,
d84f4f99 2608 const struct cred *cred, key_perm_t perm)
e114e473
CS
2609{
2610 struct key *keyp;
2611
2612 keyp = key_ref_to_ptr(key_ref);
2613 if (keyp == NULL)
2614 return -EINVAL;
2615 /*
2616 * If the key hasn't been initialized give it access so that
2617 * it may do so.
2618 */
2619 if (keyp->security == NULL)
2620 return 0;
2621 /*
2622 * This should not occur
2623 */
d84f4f99 2624 if (cred->security == NULL)
e114e473
CS
2625 return -EACCES;
2626
d84f4f99 2627 return smk_access(cred->security, keyp->security, MAY_READWRITE);
e114e473
CS
2628}
2629#endif /* CONFIG_KEYS */
2630
d20bdda6
AD
2631/*
2632 * Smack Audit hooks
2633 *
2634 * Audit requires a unique representation of each Smack specific
2635 * rule. This unique representation is used to distinguish the
2636 * object to be audited from remaining kernel objects and also
2637 * works as a glue between the audit hooks.
2638 *
2639 * Since repository entries are added but never deleted, we'll use
2640 * the smack_known label address related to the given audit rule as
2641 * the needed unique representation. This also better fits the smack
2642 * model where nearly everything is a label.
2643 */
2644#ifdef CONFIG_AUDIT
2645
2646/**
2647 * smack_audit_rule_init - Initialize a smack audit rule
2648 * @field: audit rule fields given from user-space (audit.h)
2649 * @op: required testing operator (=, !=, >, <, ...)
2650 * @rulestr: smack label to be audited
2651 * @vrule: pointer to save our own audit rule representation
2652 *
2653 * Prepare to audit cases where (@field @op @rulestr) is true.
2654 * The label to be audited is created if necessay.
2655 */
2656static int smack_audit_rule_init(u32 field, u32 op, char *rulestr, void **vrule)
2657{
2658 char **rule = (char **)vrule;
2659 *rule = NULL;
2660
2661 if (field != AUDIT_SUBJ_USER && field != AUDIT_OBJ_USER)
2662 return -EINVAL;
2663
5af75d8d 2664 if (op != Audit_equal && op != Audit_not_equal)
d20bdda6
AD
2665 return -EINVAL;
2666
2667 *rule = smk_import(rulestr, 0);
2668
2669 return 0;
2670}
2671
2672/**
2673 * smack_audit_rule_known - Distinguish Smack audit rules
2674 * @krule: rule of interest, in Audit kernel representation format
2675 *
2676 * This is used to filter Smack rules from remaining Audit ones.
2677 * If it's proved that this rule belongs to us, the
2678 * audit_rule_match hook will be called to do the final judgement.
2679 */
2680static int smack_audit_rule_known(struct audit_krule *krule)
2681{
2682 struct audit_field *f;
2683 int i;
2684
2685 for (i = 0; i < krule->field_count; i++) {
2686 f = &krule->fields[i];
2687
2688 if (f->type == AUDIT_SUBJ_USER || f->type == AUDIT_OBJ_USER)
2689 return 1;
2690 }
2691
2692 return 0;
2693}
2694
2695/**
2696 * smack_audit_rule_match - Audit given object ?
2697 * @secid: security id for identifying the object to test
2698 * @field: audit rule flags given from user-space
2699 * @op: required testing operator
2700 * @vrule: smack internal rule presentation
2701 * @actx: audit context associated with the check
2702 *
2703 * The core Audit hook. It's used to take the decision of
2704 * whether to audit or not to audit a given object.
2705 */
2706static int smack_audit_rule_match(u32 secid, u32 field, u32 op, void *vrule,
2707 struct audit_context *actx)
2708{
2709 char *smack;
2710 char *rule = vrule;
2711
2712 if (!rule) {
2713 audit_log(actx, GFP_KERNEL, AUDIT_SELINUX_ERR,
2714 "Smack: missing rule\n");
2715 return -ENOENT;
2716 }
2717
2718 if (field != AUDIT_SUBJ_USER && field != AUDIT_OBJ_USER)
2719 return 0;
2720
2721 smack = smack_from_secid(secid);
2722
2723 /*
2724 * No need to do string comparisons. If a match occurs,
2725 * both pointers will point to the same smack_known
2726 * label.
2727 */
5af75d8d 2728 if (op == Audit_equal)
d20bdda6 2729 return (rule == smack);
5af75d8d 2730 if (op == Audit_not_equal)
d20bdda6
AD
2731 return (rule != smack);
2732
2733 return 0;
2734}
2735
2736/**
2737 * smack_audit_rule_free - free smack rule representation
2738 * @vrule: rule to be freed.
2739 *
2740 * No memory was allocated.
2741 */
2742static void smack_audit_rule_free(void *vrule)
2743{
2744 /* No-op */
2745}
2746
2747#endif /* CONFIG_AUDIT */
2748
251a2a95 2749/**
e114e473
CS
2750 * smack_secid_to_secctx - return the smack label for a secid
2751 * @secid: incoming integer
2752 * @secdata: destination
2753 * @seclen: how long it is
2754 *
2755 * Exists for networking code.
2756 */
2757static int smack_secid_to_secctx(u32 secid, char **secdata, u32 *seclen)
2758{
2759 char *sp = smack_from_secid(secid);
2760
2761 *secdata = sp;
2762 *seclen = strlen(sp);
2763 return 0;
2764}
2765
251a2a95 2766/**
4bc87e62
CS
2767 * smack_secctx_to_secid - return the secid for a smack label
2768 * @secdata: smack label
2769 * @seclen: how long result is
2770 * @secid: outgoing integer
2771 *
2772 * Exists for audit and networking code.
2773 */
e52c1764 2774static int smack_secctx_to_secid(const char *secdata, u32 seclen, u32 *secid)
4bc87e62
CS
2775{
2776 *secid = smack_to_secid(secdata);
2777 return 0;
2778}
2779
251a2a95 2780/**
e114e473 2781 * smack_release_secctx - don't do anything.
251a2a95
RD
2782 * @secdata: unused
2783 * @seclen: unused
e114e473
CS
2784 *
2785 * Exists to make sure nothing gets done, and properly
2786 */
2787static void smack_release_secctx(char *secdata, u32 seclen)
2788{
2789}
2790
076c54c5
AD
2791struct security_operations smack_ops = {
2792 .name = "smack",
2793
5cd9c58f
DH
2794 .ptrace_may_access = smack_ptrace_may_access,
2795 .ptrace_traceme = smack_ptrace_traceme,
e114e473 2796 .capget = cap_capget,
d84f4f99 2797 .capset = cap_capset,
e114e473
CS
2798 .capable = cap_capable,
2799 .syslog = smack_syslog,
2800 .settime = cap_settime,
2801 .vm_enough_memory = cap_vm_enough_memory,
2802
a6f76f23 2803 .bprm_set_creds = cap_bprm_set_creds,
e114e473
CS
2804 .bprm_secureexec = cap_bprm_secureexec,
2805
2806 .sb_alloc_security = smack_sb_alloc_security,
2807 .sb_free_security = smack_sb_free_security,
2808 .sb_copy_data = smack_sb_copy_data,
2809 .sb_kern_mount = smack_sb_kern_mount,
2810 .sb_statfs = smack_sb_statfs,
2811 .sb_mount = smack_sb_mount,
2812 .sb_umount = smack_sb_umount,
2813
2814 .inode_alloc_security = smack_inode_alloc_security,
2815 .inode_free_security = smack_inode_free_security,
2816 .inode_init_security = smack_inode_init_security,
2817 .inode_link = smack_inode_link,
2818 .inode_unlink = smack_inode_unlink,
2819 .inode_rmdir = smack_inode_rmdir,
2820 .inode_rename = smack_inode_rename,
2821 .inode_permission = smack_inode_permission,
2822 .inode_setattr = smack_inode_setattr,
2823 .inode_getattr = smack_inode_getattr,
2824 .inode_setxattr = smack_inode_setxattr,
2825 .inode_post_setxattr = smack_inode_post_setxattr,
2826 .inode_getxattr = smack_inode_getxattr,
2827 .inode_removexattr = smack_inode_removexattr,
bcdca225
CS
2828 .inode_need_killpriv = cap_inode_need_killpriv,
2829 .inode_killpriv = cap_inode_killpriv,
e114e473
CS
2830 .inode_getsecurity = smack_inode_getsecurity,
2831 .inode_setsecurity = smack_inode_setsecurity,
2832 .inode_listsecurity = smack_inode_listsecurity,
d20bdda6 2833 .inode_getsecid = smack_inode_getsecid,
e114e473
CS
2834
2835 .file_permission = smack_file_permission,
2836 .file_alloc_security = smack_file_alloc_security,
2837 .file_free_security = smack_file_free_security,
2838 .file_ioctl = smack_file_ioctl,
2839 .file_lock = smack_file_lock,
2840 .file_fcntl = smack_file_fcntl,
2841 .file_set_fowner = smack_file_set_fowner,
2842 .file_send_sigiotask = smack_file_send_sigiotask,
2843 .file_receive = smack_file_receive,
2844
f1752eec 2845 .cred_free = smack_cred_free,
d84f4f99
DH
2846 .cred_prepare = smack_cred_prepare,
2847 .cred_commit = smack_cred_commit,
3a3b7ce9
DH
2848 .kernel_act_as = smack_kernel_act_as,
2849 .kernel_create_files_as = smack_kernel_create_files_as,
d84f4f99 2850 .task_fix_setuid = cap_task_fix_setuid,
e114e473
CS
2851 .task_setpgid = smack_task_setpgid,
2852 .task_getpgid = smack_task_getpgid,
2853 .task_getsid = smack_task_getsid,
2854 .task_getsecid = smack_task_getsecid,
2855 .task_setnice = smack_task_setnice,
2856 .task_setioprio = smack_task_setioprio,
2857 .task_getioprio = smack_task_getioprio,
2858 .task_setscheduler = smack_task_setscheduler,
2859 .task_getscheduler = smack_task_getscheduler,
2860 .task_movememory = smack_task_movememory,
2861 .task_kill = smack_task_kill,
2862 .task_wait = smack_task_wait,
e114e473 2863 .task_to_inode = smack_task_to_inode,
1236cc3c 2864 .task_prctl = cap_task_prctl,
e114e473
CS
2865
2866 .ipc_permission = smack_ipc_permission,
d20bdda6 2867 .ipc_getsecid = smack_ipc_getsecid,
e114e473
CS
2868
2869 .msg_msg_alloc_security = smack_msg_msg_alloc_security,
2870 .msg_msg_free_security = smack_msg_msg_free_security,
2871
2872 .msg_queue_alloc_security = smack_msg_queue_alloc_security,
2873 .msg_queue_free_security = smack_msg_queue_free_security,
2874 .msg_queue_associate = smack_msg_queue_associate,
2875 .msg_queue_msgctl = smack_msg_queue_msgctl,
2876 .msg_queue_msgsnd = smack_msg_queue_msgsnd,
2877 .msg_queue_msgrcv = smack_msg_queue_msgrcv,
2878
2879 .shm_alloc_security = smack_shm_alloc_security,
2880 .shm_free_security = smack_shm_free_security,
2881 .shm_associate = smack_shm_associate,
2882 .shm_shmctl = smack_shm_shmctl,
2883 .shm_shmat = smack_shm_shmat,
2884
2885 .sem_alloc_security = smack_sem_alloc_security,
2886 .sem_free_security = smack_sem_free_security,
2887 .sem_associate = smack_sem_associate,
2888 .sem_semctl = smack_sem_semctl,
2889 .sem_semop = smack_sem_semop,
2890
2891 .netlink_send = cap_netlink_send,
2892 .netlink_recv = cap_netlink_recv,
2893
2894 .d_instantiate = smack_d_instantiate,
2895
2896 .getprocattr = smack_getprocattr,
2897 .setprocattr = smack_setprocattr,
2898
2899 .unix_stream_connect = smack_unix_stream_connect,
2900 .unix_may_send = smack_unix_may_send,
2901
2902 .socket_post_create = smack_socket_post_create,
6d3dc07c
CS
2903 .socket_connect = smack_socket_connect,
2904 .socket_sendmsg = smack_socket_sendmsg,
e114e473
CS
2905 .socket_sock_rcv_skb = smack_socket_sock_rcv_skb,
2906 .socket_getpeersec_stream = smack_socket_getpeersec_stream,
2907 .socket_getpeersec_dgram = smack_socket_getpeersec_dgram,
2908 .sk_alloc_security = smack_sk_alloc_security,
2909 .sk_free_security = smack_sk_free_security,
2910 .sock_graft = smack_sock_graft,
2911 .inet_conn_request = smack_inet_conn_request,
d20bdda6 2912
e114e473
CS
2913 /* key management security hooks */
2914#ifdef CONFIG_KEYS
2915 .key_alloc = smack_key_alloc,
2916 .key_free = smack_key_free,
2917 .key_permission = smack_key_permission,
2918#endif /* CONFIG_KEYS */
d20bdda6
AD
2919
2920 /* Audit hooks */
2921#ifdef CONFIG_AUDIT
2922 .audit_rule_init = smack_audit_rule_init,
2923 .audit_rule_known = smack_audit_rule_known,
2924 .audit_rule_match = smack_audit_rule_match,
2925 .audit_rule_free = smack_audit_rule_free,
2926#endif /* CONFIG_AUDIT */
2927
e114e473 2928 .secid_to_secctx = smack_secid_to_secctx,
4bc87e62 2929 .secctx_to_secid = smack_secctx_to_secid,
e114e473
CS
2930 .release_secctx = smack_release_secctx,
2931};
2932
2933/**
2934 * smack_init - initialize the smack system
2935 *
2936 * Returns 0
2937 */
2938static __init int smack_init(void)
2939{
d84f4f99
DH
2940 struct cred *cred;
2941
076c54c5
AD
2942 if (!security_module_enable(&smack_ops))
2943 return 0;
2944
e114e473
CS
2945 printk(KERN_INFO "Smack: Initializing.\n");
2946
2947 /*
2948 * Set the security state for the initial task.
2949 */
d84f4f99
DH
2950 cred = (struct cred *) current->cred;
2951 cred->security = &smack_known_floor.smk_known;
e114e473
CS
2952
2953 /*
2954 * Initialize locks
2955 */
e114e473
CS
2956 spin_lock_init(&smack_known_huh.smk_cipsolock);
2957 spin_lock_init(&smack_known_hat.smk_cipsolock);
2958 spin_lock_init(&smack_known_star.smk_cipsolock);
2959 spin_lock_init(&smack_known_floor.smk_cipsolock);
2960 spin_lock_init(&smack_known_invalid.smk_cipsolock);
2961
2962 /*
2963 * Register with LSM
2964 */
2965 if (register_security(&smack_ops))
2966 panic("smack: Unable to register with kernel.\n");
2967
2968 return 0;
2969}
2970
2971/*
2972 * Smack requires early initialization in order to label
2973 * all processes and objects when they are created.
2974 */
2975security_initcall(smack_init);