Merge commit 'origin/master' into next
[deliverable/linux.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>
e114e473
CS
30
31#include "smack.h"
32
c69e8d9c
DH
33#define task_security(task) (task_cred_xxx((task), security))
34
e114e473
CS
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
CS
93 * @ctp: child task pointer
94 *
95 * Returns 0 if access is OK, an error code otherwise
96 *
97 * Do the capability checks, and require read and write.
98 */
5cd9c58f 99static int smack_ptrace_may_access(struct task_struct *ctp, unsigned int mode)
e114e473
CS
100{
101 int rc;
102
5cd9c58f 103 rc = cap_ptrace_may_access(ctp, mode);
e114e473
CS
104 if (rc != 0)
105 return rc;
106
d84f4f99 107 rc = smk_access(current_security(), task_security(ctp), MAY_READWRITE);
5cd9c58f 108 if (rc != 0 && capable(CAP_MAC_OVERRIDE))
e114e473 109 return 0;
5cd9c58f
DH
110 return rc;
111}
112
113/**
114 * smack_ptrace_traceme - Smack approval on PTRACE_TRACEME
115 * @ptp: parent task pointer
116 *
117 * Returns 0 if access is OK, an error code otherwise
118 *
119 * Do the capability checks, and require read and write.
120 */
121static int smack_ptrace_traceme(struct task_struct *ptp)
122{
123 int rc;
124
125 rc = cap_ptrace_traceme(ptp);
126 if (rc != 0)
127 return rc;
e114e473 128
d84f4f99 129 rc = smk_access(task_security(ptp), current_security(), MAY_READWRITE);
5cd9c58f
DH
130 if (rc != 0 && has_capability(ptp, CAP_MAC_OVERRIDE))
131 return 0;
e114e473
CS
132 return rc;
133}
134
135/**
136 * smack_syslog - Smack approval on syslog
137 * @type: message type
138 *
139 * Require that the task has the floor label
140 *
141 * Returns 0 on success, error code otherwise.
142 */
143static int smack_syslog(int type)
144{
145 int rc;
86a264ab 146 char *sp = current_security();
e114e473
CS
147
148 rc = cap_syslog(type);
149 if (rc != 0)
150 return rc;
151
152 if (capable(CAP_MAC_OVERRIDE))
153 return 0;
154
155 if (sp != smack_known_floor.smk_known)
156 rc = -EACCES;
157
158 return rc;
159}
160
161
162/*
163 * Superblock Hooks.
164 */
165
166/**
167 * smack_sb_alloc_security - allocate a superblock blob
168 * @sb: the superblock getting the blob
169 *
170 * Returns 0 on success or -ENOMEM on error.
171 */
172static int smack_sb_alloc_security(struct super_block *sb)
173{
174 struct superblock_smack *sbsp;
175
176 sbsp = kzalloc(sizeof(struct superblock_smack), GFP_KERNEL);
177
178 if (sbsp == NULL)
179 return -ENOMEM;
180
181 sbsp->smk_root = smack_known_floor.smk_known;
182 sbsp->smk_default = smack_known_floor.smk_known;
183 sbsp->smk_floor = smack_known_floor.smk_known;
184 sbsp->smk_hat = smack_known_hat.smk_known;
185 sbsp->smk_initialized = 0;
186 spin_lock_init(&sbsp->smk_sblock);
187
188 sb->s_security = sbsp;
189
190 return 0;
191}
192
193/**
194 * smack_sb_free_security - free a superblock blob
195 * @sb: the superblock getting the blob
196 *
197 */
198static void smack_sb_free_security(struct super_block *sb)
199{
200 kfree(sb->s_security);
201 sb->s_security = NULL;
202}
203
204/**
205 * smack_sb_copy_data - copy mount options data for processing
206 * @type: file system type
207 * @orig: where to start
208 * @smackopts
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)
e114e473
CS
216{
217 char *cp, *commap, *otheropts, *dp;
218
e114e473
CS
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
e114e473
CS
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
CS
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
334 * @nd: mount point
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;
e114e473
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
373 * @inode - the inode in need of a blob
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
387 * @inode - the inode with a blob
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
541 * @nd: unused
542 *
543 * This is the important Smack hook.
544 *
545 * Returns 0 if access is permitted, -EACCES otherwise
546 */
b77b0646 547static int smack_inode_permission(struct inode *inode, int mask)
e114e473
CS
548{
549 /*
550 * No permission to check. Existence test. Yup, it's there.
551 */
552 if (mask == 0)
553 return 0;
554
555 return smk_curacc(smk_of_inode(inode), mask);
556}
557
558/**
559 * smack_inode_setattr - Smack check for setting attributes
560 * @dentry: the object
561 * @iattr: for the force flag
562 *
563 * Returns 0 if access is permitted, an error code otherwise
564 */
565static int smack_inode_setattr(struct dentry *dentry, struct iattr *iattr)
566{
567 /*
568 * Need to allow for clearing the setuid bit.
569 */
570 if (iattr->ia_valid & ATTR_FORCE)
571 return 0;
572
573 return smk_curacc(smk_of_inode(dentry->d_inode), MAY_WRITE);
574}
575
576/**
577 * smack_inode_getattr - Smack check for getting attributes
578 * @mnt: unused
579 * @dentry: the object
580 *
581 * Returns 0 if access is permitted, an error code otherwise
582 */
583static int smack_inode_getattr(struct vfsmount *mnt, struct dentry *dentry)
584{
585 return smk_curacc(smk_of_inode(dentry->d_inode), MAY_READ);
586}
587
588/**
589 * smack_inode_setxattr - Smack check for setting xattrs
590 * @dentry: the object
591 * @name: name of the attribute
592 * @value: unused
593 * @size: unused
594 * @flags: unused
595 *
596 * This protects the Smack attribute explicitly.
597 *
598 * Returns 0 if access is permitted, an error code otherwise
599 */
8f0cfa52
DH
600static int smack_inode_setxattr(struct dentry *dentry, const char *name,
601 const void *value, size_t size, int flags)
e114e473 602{
bcdca225 603 int rc = 0;
e114e473 604
bcdca225
CS
605 if (strcmp(name, XATTR_NAME_SMACK) == 0 ||
606 strcmp(name, XATTR_NAME_SMACKIPIN) == 0 ||
607 strcmp(name, XATTR_NAME_SMACKIPOUT) == 0) {
608 if (!capable(CAP_MAC_ADMIN))
609 rc = -EPERM;
610 } else
611 rc = cap_inode_setxattr(dentry, name, value, size, flags);
612
613 if (rc == 0)
614 rc = smk_curacc(smk_of_inode(dentry->d_inode), MAY_WRITE);
615
616 return rc;
e114e473
CS
617}
618
619/**
620 * smack_inode_post_setxattr - Apply the Smack update approved above
621 * @dentry: object
622 * @name: attribute name
623 * @value: attribute value
624 * @size: attribute size
625 * @flags: unused
626 *
627 * Set the pointer in the inode blob to the entry found
628 * in the master label list.
629 */
8f0cfa52
DH
630static void smack_inode_post_setxattr(struct dentry *dentry, const char *name,
631 const void *value, size_t size, int flags)
e114e473
CS
632{
633 struct inode_smack *isp;
634 char *nsp;
635
636 /*
637 * Not SMACK
638 */
639 if (strcmp(name, XATTR_NAME_SMACK))
640 return;
641
642 if (size >= SMK_LABELLEN)
643 return;
644
645 isp = dentry->d_inode->i_security;
646
647 /*
648 * No locking is done here. This is a pointer
649 * assignment.
650 */
651 nsp = smk_import(value, size);
652 if (nsp != NULL)
653 isp->smk_inode = nsp;
654 else
655 isp->smk_inode = smack_known_invalid.smk_known;
656
657 return;
658}
659
660/*
661 * smack_inode_getxattr - Smack check on getxattr
662 * @dentry: the object
663 * @name: unused
664 *
665 * Returns 0 if access is permitted, an error code otherwise
666 */
8f0cfa52 667static int smack_inode_getxattr(struct dentry *dentry, const char *name)
e114e473
CS
668{
669 return smk_curacc(smk_of_inode(dentry->d_inode), MAY_READ);
670}
671
672/*
673 * smack_inode_removexattr - Smack check on removexattr
674 * @dentry: the object
675 * @name: name of the attribute
676 *
677 * Removing the Smack attribute requires CAP_MAC_ADMIN
678 *
679 * Returns 0 if access is permitted, an error code otherwise
680 */
8f0cfa52 681static int smack_inode_removexattr(struct dentry *dentry, const char *name)
e114e473 682{
bcdca225 683 int rc = 0;
e114e473 684
bcdca225
CS
685 if (strcmp(name, XATTR_NAME_SMACK) == 0 ||
686 strcmp(name, XATTR_NAME_SMACKIPIN) == 0 ||
687 strcmp(name, XATTR_NAME_SMACKIPOUT) == 0) {
688 if (!capable(CAP_MAC_ADMIN))
689 rc = -EPERM;
690 } else
691 rc = cap_inode_removexattr(dentry, name);
692
693 if (rc == 0)
694 rc = smk_curacc(smk_of_inode(dentry->d_inode), MAY_WRITE);
695
696 return rc;
e114e473
CS
697}
698
699/**
700 * smack_inode_getsecurity - get smack xattrs
701 * @inode: the object
702 * @name: attribute name
703 * @buffer: where to put the result
704 * @size: size of the buffer
705 * @err: unused
706 *
707 * Returns the size of the attribute or an error code
708 */
709static int smack_inode_getsecurity(const struct inode *inode,
710 const char *name, void **buffer,
711 bool alloc)
712{
713 struct socket_smack *ssp;
714 struct socket *sock;
715 struct super_block *sbp;
716 struct inode *ip = (struct inode *)inode;
717 char *isp;
718 int ilen;
719 int rc = 0;
720
721 if (strcmp(name, XATTR_SMACK_SUFFIX) == 0) {
722 isp = smk_of_inode(inode);
723 ilen = strlen(isp) + 1;
724 *buffer = isp;
725 return ilen;
726 }
727
728 /*
729 * The rest of the Smack xattrs are only on sockets.
730 */
731 sbp = ip->i_sb;
732 if (sbp->s_magic != SOCKFS_MAGIC)
733 return -EOPNOTSUPP;
734
735 sock = SOCKET_I(ip);
2e1d146a 736 if (sock == NULL || sock->sk == NULL)
e114e473
CS
737 return -EOPNOTSUPP;
738
739 ssp = sock->sk->sk_security;
740
741 if (strcmp(name, XATTR_SMACK_IPIN) == 0)
742 isp = ssp->smk_in;
743 else if (strcmp(name, XATTR_SMACK_IPOUT) == 0)
744 isp = ssp->smk_out;
745 else
746 return -EOPNOTSUPP;
747
748 ilen = strlen(isp) + 1;
749 if (rc == 0) {
750 *buffer = isp;
751 rc = ilen;
752 }
753
754 return rc;
755}
756
757
758/**
759 * smack_inode_listsecurity - list the Smack attributes
760 * @inode: the object
761 * @buffer: where they go
762 * @buffer_size: size of buffer
763 *
764 * Returns 0 on success, -EINVAL otherwise
765 */
766static int smack_inode_listsecurity(struct inode *inode, char *buffer,
767 size_t buffer_size)
768{
769 int len = strlen(XATTR_NAME_SMACK);
770
771 if (buffer != NULL && len <= buffer_size) {
772 memcpy(buffer, XATTR_NAME_SMACK, len);
773 return len;
774 }
775 return -EINVAL;
776}
777
d20bdda6
AD
778/**
779 * smack_inode_getsecid - Extract inode's security id
780 * @inode: inode to extract the info from
781 * @secid: where result will be saved
782 */
783static void smack_inode_getsecid(const struct inode *inode, u32 *secid)
784{
785 struct inode_smack *isp = inode->i_security;
786
787 *secid = smack_to_secid(isp->smk_inode);
788}
789
e114e473
CS
790/*
791 * File Hooks
792 */
793
794/**
795 * smack_file_permission - Smack check on file operations
796 * @file: unused
797 * @mask: unused
798 *
799 * Returns 0
800 *
801 * Should access checks be done on each read or write?
802 * UNICOS and SELinux say yes.
803 * Trusted Solaris, Trusted Irix, and just about everyone else says no.
804 *
805 * I'll say no for now. Smack does not do the frequent
806 * label changing that SELinux does.
807 */
808static int smack_file_permission(struct file *file, int mask)
809{
810 return 0;
811}
812
813/**
814 * smack_file_alloc_security - assign a file security blob
815 * @file: the object
816 *
817 * The security blob for a file is a pointer to the master
818 * label list, so no allocation is done.
819 *
820 * Returns 0
821 */
822static int smack_file_alloc_security(struct file *file)
823{
86a264ab 824 file->f_security = current_security();
e114e473
CS
825 return 0;
826}
827
828/**
829 * smack_file_free_security - clear a file security blob
830 * @file: the object
831 *
832 * The security blob for a file is a pointer to the master
833 * label list, so no memory is freed.
834 */
835static void smack_file_free_security(struct file *file)
836{
837 file->f_security = NULL;
838}
839
840/**
841 * smack_file_ioctl - Smack check on ioctls
842 * @file: the object
843 * @cmd: what to do
844 * @arg: unused
845 *
846 * Relies heavily on the correct use of the ioctl command conventions.
847 *
848 * Returns 0 if allowed, error code otherwise
849 */
850static int smack_file_ioctl(struct file *file, unsigned int cmd,
851 unsigned long arg)
852{
853 int rc = 0;
854
855 if (_IOC_DIR(cmd) & _IOC_WRITE)
856 rc = smk_curacc(file->f_security, MAY_WRITE);
857
858 if (rc == 0 && (_IOC_DIR(cmd) & _IOC_READ))
859 rc = smk_curacc(file->f_security, MAY_READ);
860
861 return rc;
862}
863
864/**
865 * smack_file_lock - Smack check on file locking
866 * @file: the object
867 * @cmd unused
868 *
869 * Returns 0 if current has write access, error code otherwise
870 */
871static int smack_file_lock(struct file *file, unsigned int cmd)
872{
873 return smk_curacc(file->f_security, MAY_WRITE);
874}
875
876/**
877 * smack_file_fcntl - Smack check on fcntl
878 * @file: the object
879 * @cmd: what action to check
880 * @arg: unused
881 *
882 * Returns 0 if current has access, error code otherwise
883 */
884static int smack_file_fcntl(struct file *file, unsigned int cmd,
885 unsigned long arg)
886{
887 int rc;
888
889 switch (cmd) {
890 case F_DUPFD:
891 case F_GETFD:
892 case F_GETFL:
893 case F_GETLK:
894 case F_GETOWN:
895 case F_GETSIG:
896 rc = smk_curacc(file->f_security, MAY_READ);
897 break;
898 case F_SETFD:
899 case F_SETFL:
900 case F_SETLK:
901 case F_SETLKW:
902 case F_SETOWN:
903 case F_SETSIG:
904 rc = smk_curacc(file->f_security, MAY_WRITE);
905 break;
906 default:
907 rc = smk_curacc(file->f_security, MAY_READWRITE);
908 }
909
910 return rc;
911}
912
913/**
914 * smack_file_set_fowner - set the file security blob value
915 * @file: object in question
916 *
917 * Returns 0
918 * Further research may be required on this one.
919 */
920static int smack_file_set_fowner(struct file *file)
921{
86a264ab 922 file->f_security = current_security();
e114e473
CS
923 return 0;
924}
925
926/**
927 * smack_file_send_sigiotask - Smack on sigio
928 * @tsk: The target task
929 * @fown: the object the signal come from
930 * @signum: unused
931 *
932 * Allow a privileged task to get signals even if it shouldn't
933 *
934 * Returns 0 if a subject with the object's smack could
935 * write to the task, an error code otherwise.
936 */
937static int smack_file_send_sigiotask(struct task_struct *tsk,
938 struct fown_struct *fown, int signum)
939{
940 struct file *file;
941 int rc;
942
943 /*
944 * struct fown_struct is never outside the context of a struct file
945 */
946 file = container_of(fown, struct file, f_owner);
b6dff3ec 947 rc = smk_access(file->f_security, tsk->cred->security, MAY_WRITE);
5cd9c58f 948 if (rc != 0 && has_capability(tsk, CAP_MAC_OVERRIDE))
e114e473
CS
949 return 0;
950 return rc;
951}
952
953/**
954 * smack_file_receive - Smack file receive check
955 * @file: the object
956 *
957 * Returns 0 if current has access, error code otherwise
958 */
959static int smack_file_receive(struct file *file)
960{
961 int may = 0;
962
963 /*
964 * This code relies on bitmasks.
965 */
966 if (file->f_mode & FMODE_READ)
967 may = MAY_READ;
968 if (file->f_mode & FMODE_WRITE)
969 may |= MAY_WRITE;
970
971 return smk_curacc(file->f_security, may);
972}
973
974/*
975 * Task hooks
976 */
977
e114e473 978/**
f1752eec
DH
979 * smack_cred_free - "free" task-level security credentials
980 * @cred: the credentials in question
e114e473
CS
981 *
982 * Smack isn't using copies of blobs. Everyone
983 * points to an immutable list. The blobs never go away.
984 * There is no leak here.
985 */
f1752eec 986static void smack_cred_free(struct cred *cred)
e114e473 987{
f1752eec 988 cred->security = NULL;
e114e473
CS
989}
990
d84f4f99
DH
991/**
992 * smack_cred_prepare - prepare new set of credentials for modification
993 * @new: the new credentials
994 * @old: the original credentials
995 * @gfp: the atomicity of any memory allocations
996 *
997 * Prepare a new set of credentials for modification.
998 */
999static int smack_cred_prepare(struct cred *new, const struct cred *old,
1000 gfp_t gfp)
1001{
1002 new->security = old->security;
1003 return 0;
1004}
1005
1006/*
1007 * commit new credentials
1008 * @new: the new credentials
1009 * @old: the original credentials
1010 */
1011static void smack_cred_commit(struct cred *new, const struct cred *old)
1012{
1013}
1014
3a3b7ce9
DH
1015/**
1016 * smack_kernel_act_as - Set the subjective context in a set of credentials
1017 * @new points to the set of credentials to be modified.
1018 * @secid specifies the security ID to be set
1019 *
1020 * Set the security data for a kernel service.
1021 */
1022static int smack_kernel_act_as(struct cred *new, u32 secid)
1023{
1024 char *smack = smack_from_secid(secid);
1025
1026 if (smack == NULL)
1027 return -EINVAL;
1028
1029 new->security = smack;
1030 return 0;
1031}
1032
1033/**
1034 * smack_kernel_create_files_as - Set the file creation label in a set of creds
1035 * @new points to the set of credentials to be modified
1036 * @inode points to the inode to use as a reference
1037 *
1038 * Set the file creation context in a set of credentials to the same
1039 * as the objective context of the specified inode
1040 */
1041static int smack_kernel_create_files_as(struct cred *new,
1042 struct inode *inode)
1043{
1044 struct inode_smack *isp = inode->i_security;
1045
1046 new->security = isp->smk_inode;
1047 return 0;
1048}
1049
e114e473
CS
1050/**
1051 * smack_task_setpgid - Smack check on setting pgid
1052 * @p: the task object
1053 * @pgid: unused
1054 *
1055 * Return 0 if write access is permitted
1056 */
1057static int smack_task_setpgid(struct task_struct *p, pid_t pgid)
1058{
c69e8d9c 1059 return smk_curacc(task_security(p), MAY_WRITE);
e114e473
CS
1060}
1061
1062/**
1063 * smack_task_getpgid - Smack access check for getpgid
1064 * @p: the object task
1065 *
1066 * Returns 0 if current can read the object task, error code otherwise
1067 */
1068static int smack_task_getpgid(struct task_struct *p)
1069{
c69e8d9c 1070 return smk_curacc(task_security(p), MAY_READ);
e114e473
CS
1071}
1072
1073/**
1074 * smack_task_getsid - Smack access check for getsid
1075 * @p: the object task
1076 *
1077 * Returns 0 if current can read the object task, error code otherwise
1078 */
1079static int smack_task_getsid(struct task_struct *p)
1080{
c69e8d9c 1081 return smk_curacc(task_security(p), MAY_READ);
e114e473
CS
1082}
1083
1084/**
1085 * smack_task_getsecid - get the secid of the task
1086 * @p: the object task
1087 * @secid: where to put the result
1088 *
1089 * Sets the secid to contain a u32 version of the smack label.
1090 */
1091static void smack_task_getsecid(struct task_struct *p, u32 *secid)
1092{
c69e8d9c 1093 *secid = smack_to_secid(task_security(p));
e114e473
CS
1094}
1095
1096/**
1097 * smack_task_setnice - Smack check on setting nice
1098 * @p: the task object
1099 * @nice: unused
1100 *
1101 * Return 0 if write access is permitted
1102 */
1103static int smack_task_setnice(struct task_struct *p, int nice)
1104{
bcdca225
CS
1105 int rc;
1106
1107 rc = cap_task_setnice(p, nice);
1108 if (rc == 0)
c69e8d9c 1109 rc = smk_curacc(task_security(p), MAY_WRITE);
bcdca225 1110 return rc;
e114e473
CS
1111}
1112
1113/**
1114 * smack_task_setioprio - Smack check on setting ioprio
1115 * @p: the task object
1116 * @ioprio: unused
1117 *
1118 * Return 0 if write access is permitted
1119 */
1120static int smack_task_setioprio(struct task_struct *p, int ioprio)
1121{
bcdca225
CS
1122 int rc;
1123
1124 rc = cap_task_setioprio(p, ioprio);
1125 if (rc == 0)
c69e8d9c 1126 rc = smk_curacc(task_security(p), MAY_WRITE);
bcdca225 1127 return rc;
e114e473
CS
1128}
1129
1130/**
1131 * smack_task_getioprio - Smack check on reading ioprio
1132 * @p: the task object
1133 *
1134 * Return 0 if read access is permitted
1135 */
1136static int smack_task_getioprio(struct task_struct *p)
1137{
c69e8d9c 1138 return smk_curacc(task_security(p), MAY_READ);
e114e473
CS
1139}
1140
1141/**
1142 * smack_task_setscheduler - Smack check on setting scheduler
1143 * @p: the task object
1144 * @policy: unused
1145 * @lp: unused
1146 *
1147 * Return 0 if read access is permitted
1148 */
1149static int smack_task_setscheduler(struct task_struct *p, int policy,
1150 struct sched_param *lp)
1151{
bcdca225
CS
1152 int rc;
1153
1154 rc = cap_task_setscheduler(p, policy, lp);
1155 if (rc == 0)
c69e8d9c 1156 rc = smk_curacc(task_security(p), MAY_WRITE);
bcdca225 1157 return rc;
e114e473
CS
1158}
1159
1160/**
1161 * smack_task_getscheduler - Smack check on reading scheduler
1162 * @p: the task object
1163 *
1164 * Return 0 if read access is permitted
1165 */
1166static int smack_task_getscheduler(struct task_struct *p)
1167{
c69e8d9c 1168 return smk_curacc(task_security(p), MAY_READ);
e114e473
CS
1169}
1170
1171/**
1172 * smack_task_movememory - Smack check on moving memory
1173 * @p: the task object
1174 *
1175 * Return 0 if write access is permitted
1176 */
1177static int smack_task_movememory(struct task_struct *p)
1178{
c69e8d9c 1179 return smk_curacc(task_security(p), MAY_WRITE);
e114e473
CS
1180}
1181
1182/**
1183 * smack_task_kill - Smack check on signal delivery
1184 * @p: the task object
1185 * @info: unused
1186 * @sig: unused
1187 * @secid: identifies the smack to use in lieu of current's
1188 *
1189 * Return 0 if write access is permitted
1190 *
1191 * The secid behavior is an artifact of an SELinux hack
1192 * in the USB code. Someday it may go away.
1193 */
1194static int smack_task_kill(struct task_struct *p, struct siginfo *info,
1195 int sig, u32 secid)
1196{
e114e473
CS
1197 /*
1198 * Sending a signal requires that the sender
1199 * can write the receiver.
1200 */
1201 if (secid == 0)
c69e8d9c 1202 return smk_curacc(task_security(p), MAY_WRITE);
e114e473
CS
1203 /*
1204 * If the secid isn't 0 we're dealing with some USB IO
1205 * specific behavior. This is not clean. For one thing
1206 * we can't take privilege into account.
1207 */
c69e8d9c 1208 return smk_access(smack_from_secid(secid), task_security(p), MAY_WRITE);
e114e473
CS
1209}
1210
1211/**
1212 * smack_task_wait - Smack access check for waiting
1213 * @p: task to wait for
1214 *
1215 * Returns 0 if current can wait for p, error code otherwise
1216 */
1217static int smack_task_wait(struct task_struct *p)
1218{
1219 int rc;
1220
c69e8d9c 1221 rc = smk_access(current_security(), task_security(p), MAY_WRITE);
e114e473
CS
1222 if (rc == 0)
1223 return 0;
1224
1225 /*
1226 * Allow the operation to succeed if either task
1227 * has privilege to perform operations that might
1228 * account for the smack labels having gotten to
1229 * be different in the first place.
1230 *
5cd9c58f 1231 * This breaks the strict subject/object access
e114e473
CS
1232 * control ideal, taking the object's privilege
1233 * state into account in the decision as well as
1234 * the smack value.
1235 */
5cd9c58f 1236 if (capable(CAP_MAC_OVERRIDE) || has_capability(p, CAP_MAC_OVERRIDE))
e114e473
CS
1237 return 0;
1238
1239 return rc;
1240}
1241
1242/**
1243 * smack_task_to_inode - copy task smack into the inode blob
1244 * @p: task to copy from
1245 * inode: inode to copy to
1246 *
1247 * Sets the smack pointer in the inode security blob
1248 */
1249static void smack_task_to_inode(struct task_struct *p, struct inode *inode)
1250{
1251 struct inode_smack *isp = inode->i_security;
c69e8d9c 1252 isp->smk_inode = task_security(p);
e114e473
CS
1253}
1254
1255/*
1256 * Socket hooks.
1257 */
1258
1259/**
1260 * smack_sk_alloc_security - Allocate a socket blob
1261 * @sk: the socket
1262 * @family: unused
1263 * @priority: memory allocation priority
1264 *
1265 * Assign Smack pointers to current
1266 *
1267 * Returns 0 on success, -ENOMEM is there's no memory
1268 */
1269static int smack_sk_alloc_security(struct sock *sk, int family, gfp_t gfp_flags)
1270{
86a264ab 1271 char *csp = current_security();
e114e473
CS
1272 struct socket_smack *ssp;
1273
1274 ssp = kzalloc(sizeof(struct socket_smack), gfp_flags);
1275 if (ssp == NULL)
1276 return -ENOMEM;
1277
1278 ssp->smk_in = csp;
1279 ssp->smk_out = csp;
6d3dc07c 1280 ssp->smk_labeled = SMACK_CIPSO_SOCKET;
e114e473
CS
1281 ssp->smk_packet[0] = '\0';
1282
1283 sk->sk_security = ssp;
1284
1285 return 0;
1286}
1287
1288/**
1289 * smack_sk_free_security - Free a socket blob
1290 * @sk: the socket
1291 *
1292 * Clears the blob pointer
1293 */
1294static void smack_sk_free_security(struct sock *sk)
1295{
1296 kfree(sk->sk_security);
1297}
1298
1299/**
1300 * smack_set_catset - convert a capset to netlabel mls categories
1301 * @catset: the Smack categories
1302 * @sap: where to put the netlabel categories
1303 *
1304 * Allocates and fills attr.mls.cat
1305 */
1306static void smack_set_catset(char *catset, struct netlbl_lsm_secattr *sap)
1307{
1308 unsigned char *cp;
1309 unsigned char m;
1310 int cat;
1311 int rc;
1312 int byte;
1313
c60264c4 1314 if (!catset)
e114e473
CS
1315 return;
1316
1317 sap->flags |= NETLBL_SECATTR_MLS_CAT;
1318 sap->attr.mls.cat = netlbl_secattr_catmap_alloc(GFP_ATOMIC);
1319 sap->attr.mls.cat->startbit = 0;
1320
1321 for (cat = 1, cp = catset, byte = 0; byte < SMK_LABELLEN; cp++, byte++)
1322 for (m = 0x80; m != 0; m >>= 1, cat++) {
1323 if ((m & *cp) == 0)
1324 continue;
1325 rc = netlbl_secattr_catmap_setbit(sap->attr.mls.cat,
1326 cat, GFP_ATOMIC);
1327 }
1328}
1329
1330/**
1331 * smack_to_secattr - fill a secattr from a smack value
1332 * @smack: the smack value
1333 * @nlsp: where the result goes
1334 *
1335 * Casey says that CIPSO is good enough for now.
1336 * It can be used to effect.
1337 * It can also be abused to effect when necessary.
1338 * Appologies to the TSIG group in general and GW in particular.
1339 */
1340static void smack_to_secattr(char *smack, struct netlbl_lsm_secattr *nlsp)
1341{
1342 struct smack_cipso cipso;
1343 int rc;
1344
6d3dc07c
CS
1345 nlsp->domain = smack;
1346 nlsp->flags = NETLBL_SECATTR_DOMAIN | NETLBL_SECATTR_MLS_LVL;
e114e473 1347
6d3dc07c
CS
1348 rc = smack_to_cipso(smack, &cipso);
1349 if (rc == 0) {
1350 nlsp->attr.mls.lvl = cipso.smk_level;
1351 smack_set_catset(cipso.smk_catset, nlsp);
1352 } else {
1353 nlsp->attr.mls.lvl = smack_cipso_direct;
1354 smack_set_catset(smack, nlsp);
e114e473
CS
1355 }
1356}
1357
1358/**
1359 * smack_netlabel - Set the secattr on a socket
1360 * @sk: the socket
6d3dc07c 1361 * @labeled: socket label scheme
e114e473
CS
1362 *
1363 * Convert the outbound smack value (smk_out) to a
1364 * secattr and attach it to the socket.
1365 *
1366 * Returns 0 on success or an error code
1367 */
6d3dc07c 1368static int smack_netlabel(struct sock *sk, int labeled)
e114e473 1369{
2e1d146a 1370 struct socket_smack *ssp;
e114e473 1371 struct netlbl_lsm_secattr secattr;
6d3dc07c 1372 int rc = 0;
e114e473 1373
2e1d146a 1374 ssp = sk->sk_security;
6d3dc07c
CS
1375 /*
1376 * Usually the netlabel code will handle changing the
1377 * packet labeling based on the label.
1378 * The case of a single label host is different, because
1379 * a single label host should never get a labeled packet
1380 * even though the label is usually associated with a packet
1381 * label.
1382 */
1383 local_bh_disable();
1384 bh_lock_sock_nested(sk);
1385
1386 if (ssp->smk_out == smack_net_ambient ||
1387 labeled == SMACK_UNLABELED_SOCKET)
1388 netlbl_sock_delattr(sk);
1389 else {
1390 netlbl_secattr_init(&secattr);
1391 smack_to_secattr(ssp->smk_out, &secattr);
1392 rc = netlbl_sock_setattr(sk, &secattr);
1393 netlbl_secattr_destroy(&secattr);
1394 }
1395
1396 bh_unlock_sock(sk);
1397 local_bh_enable();
1398 /*
1399 * Remember the label scheme used so that it is not
1400 * necessary to do the netlabel setting if it has not
1401 * changed the next time through.
1402 *
1403 * The -EDESTADDRREQ case is an indication that there's
1404 * a single level host involved.
1405 */
1406 if (rc == 0)
1407 ssp->smk_labeled = labeled;
4bc87e62 1408
e114e473
CS
1409 return rc;
1410}
1411
1412/**
1413 * smack_inode_setsecurity - set smack xattrs
1414 * @inode: the object
1415 * @name: attribute name
1416 * @value: attribute value
1417 * @size: size of the attribute
1418 * @flags: unused
1419 *
1420 * Sets the named attribute in the appropriate blob
1421 *
1422 * Returns 0 on success, or an error code
1423 */
1424static int smack_inode_setsecurity(struct inode *inode, const char *name,
1425 const void *value, size_t size, int flags)
1426{
1427 char *sp;
1428 struct inode_smack *nsp = inode->i_security;
1429 struct socket_smack *ssp;
1430 struct socket *sock;
4bc87e62 1431 int rc = 0;
e114e473
CS
1432
1433 if (value == NULL || size > SMK_LABELLEN)
1434 return -EACCES;
1435
1436 sp = smk_import(value, size);
1437 if (sp == NULL)
1438 return -EINVAL;
1439
1440 if (strcmp(name, XATTR_SMACK_SUFFIX) == 0) {
1441 nsp->smk_inode = sp;
1442 return 0;
1443 }
1444 /*
1445 * The rest of the Smack xattrs are only on sockets.
1446 */
1447 if (inode->i_sb->s_magic != SOCKFS_MAGIC)
1448 return -EOPNOTSUPP;
1449
1450 sock = SOCKET_I(inode);
2e1d146a 1451 if (sock == NULL || sock->sk == NULL)
e114e473
CS
1452 return -EOPNOTSUPP;
1453
1454 ssp = sock->sk->sk_security;
1455
1456 if (strcmp(name, XATTR_SMACK_IPIN) == 0)
1457 ssp->smk_in = sp;
1458 else if (strcmp(name, XATTR_SMACK_IPOUT) == 0) {
1459 ssp->smk_out = sp;
6d3dc07c 1460 rc = smack_netlabel(sock->sk, SMACK_CIPSO_SOCKET);
4bc87e62
CS
1461 if (rc != 0)
1462 printk(KERN_WARNING "Smack: \"%s\" netlbl error %d.\n",
1463 __func__, -rc);
e114e473
CS
1464 } else
1465 return -EOPNOTSUPP;
1466
1467 return 0;
1468}
1469
1470/**
1471 * smack_socket_post_create - finish socket setup
1472 * @sock: the socket
1473 * @family: protocol family
1474 * @type: unused
1475 * @protocol: unused
1476 * @kern: unused
1477 *
1478 * Sets the netlabel information on the socket
1479 *
1480 * Returns 0 on success, and error code otherwise
1481 */
1482static int smack_socket_post_create(struct socket *sock, int family,
1483 int type, int protocol, int kern)
1484{
2e1d146a 1485 if (family != PF_INET || sock->sk == NULL)
e114e473
CS
1486 return 0;
1487 /*
1488 * Set the outbound netlbl.
1489 */
6d3dc07c
CS
1490 return smack_netlabel(sock->sk, SMACK_CIPSO_SOCKET);
1491}
1492
1493
1494/**
1495 * smack_host_label - check host based restrictions
1496 * @sip: the object end
1497 *
1498 * looks for host based access restrictions
1499 *
1500 * This version will only be appropriate for really small
211a40c0 1501 * sets of single label hosts.
6d3dc07c
CS
1502 *
1503 * Returns the label of the far end or NULL if it's not special.
1504 */
1505static char *smack_host_label(struct sockaddr_in *sip)
1506{
1507 struct smk_netlbladdr *snp;
6d3dc07c 1508 struct in_addr *siap = &sip->sin_addr;
6d3dc07c
CS
1509
1510 if (siap->s_addr == 0)
1511 return NULL;
1512
6d3dc07c 1513 for (snp = smack_netlbladdrs; snp != NULL; snp = snp->smk_next) {
6d3dc07c 1514 /*
211a40c0 1515 * we break after finding the first match because
1516 * the list is sorted from longest to shortest mask
1517 * so we have found the most specific match
6d3dc07c 1518 */
211a40c0 1519 if ((&snp->smk_host.sin_addr)->s_addr ==
1520 (siap->s_addr & (&snp->smk_mask)->s_addr)) {
6d3dc07c 1521 return snp->smk_label;
211a40c0 1522 }
6d3dc07c
CS
1523 }
1524
211a40c0 1525 return NULL;
6d3dc07c
CS
1526}
1527
1528/**
1529 * smack_socket_connect - connect access check
1530 * @sock: the socket
1531 * @sap: the other end
1532 * @addrlen: size of sap
1533 *
1534 * Verifies that a connection may be possible
1535 *
1536 * Returns 0 on success, and error code otherwise
1537 */
1538static int smack_socket_connect(struct socket *sock, struct sockaddr *sap,
1539 int addrlen)
1540{
1541 struct socket_smack *ssp = sock->sk->sk_security;
1542 char *hostsp;
1543 int rc;
1544
1545 if (sock->sk == NULL || sock->sk->sk_family != PF_INET)
1546 return 0;
1547
1548 if (addrlen < sizeof(struct sockaddr_in))
1549 return -EINVAL;
1550
1551 hostsp = smack_host_label((struct sockaddr_in *)sap);
1552 if (hostsp == NULL) {
1553 if (ssp->smk_labeled != SMACK_CIPSO_SOCKET)
1554 return smack_netlabel(sock->sk, SMACK_CIPSO_SOCKET);
1555 return 0;
1556 }
1557
1558 rc = smk_access(ssp->smk_out, hostsp, MAY_WRITE);
1559 if (rc != 0)
1560 return rc;
1561
1562 if (ssp->smk_labeled != SMACK_UNLABELED_SOCKET)
1563 return smack_netlabel(sock->sk, SMACK_UNLABELED_SOCKET);
1564 return 0;
e114e473
CS
1565}
1566
1567/**
1568 * smack_flags_to_may - convert S_ to MAY_ values
1569 * @flags: the S_ value
1570 *
1571 * Returns the equivalent MAY_ value
1572 */
1573static int smack_flags_to_may(int flags)
1574{
1575 int may = 0;
1576
1577 if (flags & S_IRUGO)
1578 may |= MAY_READ;
1579 if (flags & S_IWUGO)
1580 may |= MAY_WRITE;
1581 if (flags & S_IXUGO)
1582 may |= MAY_EXEC;
1583
1584 return may;
1585}
1586
1587/**
1588 * smack_msg_msg_alloc_security - Set the security blob for msg_msg
1589 * @msg: the object
1590 *
1591 * Returns 0
1592 */
1593static int smack_msg_msg_alloc_security(struct msg_msg *msg)
1594{
86a264ab 1595 msg->security = current_security();
e114e473
CS
1596 return 0;
1597}
1598
1599/**
1600 * smack_msg_msg_free_security - Clear the security blob for msg_msg
1601 * @msg: the object
1602 *
1603 * Clears the blob pointer
1604 */
1605static void smack_msg_msg_free_security(struct msg_msg *msg)
1606{
1607 msg->security = NULL;
1608}
1609
1610/**
1611 * smack_of_shm - the smack pointer for the shm
1612 * @shp: the object
1613 *
1614 * Returns a pointer to the smack value
1615 */
1616static char *smack_of_shm(struct shmid_kernel *shp)
1617{
1618 return (char *)shp->shm_perm.security;
1619}
1620
1621/**
1622 * smack_shm_alloc_security - Set the security blob for shm
1623 * @shp: the object
1624 *
1625 * Returns 0
1626 */
1627static int smack_shm_alloc_security(struct shmid_kernel *shp)
1628{
1629 struct kern_ipc_perm *isp = &shp->shm_perm;
1630
86a264ab 1631 isp->security = current_security();
e114e473
CS
1632 return 0;
1633}
1634
1635/**
1636 * smack_shm_free_security - Clear the security blob for shm
1637 * @shp: the object
1638 *
1639 * Clears the blob pointer
1640 */
1641static void smack_shm_free_security(struct shmid_kernel *shp)
1642{
1643 struct kern_ipc_perm *isp = &shp->shm_perm;
1644
1645 isp->security = NULL;
1646}
1647
1648/**
1649 * smack_shm_associate - Smack access check for shm
1650 * @shp: the object
1651 * @shmflg: access requested
1652 *
1653 * Returns 0 if current has the requested access, error code otherwise
1654 */
1655static int smack_shm_associate(struct shmid_kernel *shp, int shmflg)
1656{
1657 char *ssp = smack_of_shm(shp);
1658 int may;
1659
1660 may = smack_flags_to_may(shmflg);
1661 return smk_curacc(ssp, may);
1662}
1663
1664/**
1665 * smack_shm_shmctl - Smack access check for shm
1666 * @shp: the object
1667 * @cmd: what it wants to do
1668 *
1669 * Returns 0 if current has the requested access, error code otherwise
1670 */
1671static int smack_shm_shmctl(struct shmid_kernel *shp, int cmd)
1672{
1d252fb8 1673 char *ssp;
e114e473
CS
1674 int may;
1675
1676 switch (cmd) {
1677 case IPC_STAT:
1678 case SHM_STAT:
1679 may = MAY_READ;
1680 break;
1681 case IPC_SET:
1682 case SHM_LOCK:
1683 case SHM_UNLOCK:
1684 case IPC_RMID:
1685 may = MAY_READWRITE;
1686 break;
1687 case IPC_INFO:
1688 case SHM_INFO:
1689 /*
1690 * System level information.
1691 */
1692 return 0;
1693 default:
1694 return -EINVAL;
1695 }
1696
1d252fb8 1697 ssp = smack_of_shm(shp);
e114e473
CS
1698 return smk_curacc(ssp, may);
1699}
1700
1701/**
1702 * smack_shm_shmat - Smack access for shmat
1703 * @shp: the object
1704 * @shmaddr: unused
1705 * @shmflg: access requested
1706 *
1707 * Returns 0 if current has the requested access, error code otherwise
1708 */
1709static int smack_shm_shmat(struct shmid_kernel *shp, char __user *shmaddr,
1710 int shmflg)
1711{
1712 char *ssp = smack_of_shm(shp);
1713 int may;
1714
1715 may = smack_flags_to_may(shmflg);
1716 return smk_curacc(ssp, may);
1717}
1718
1719/**
1720 * smack_of_sem - the smack pointer for the sem
1721 * @sma: the object
1722 *
1723 * Returns a pointer to the smack value
1724 */
1725static char *smack_of_sem(struct sem_array *sma)
1726{
1727 return (char *)sma->sem_perm.security;
1728}
1729
1730/**
1731 * smack_sem_alloc_security - Set the security blob for sem
1732 * @sma: the object
1733 *
1734 * Returns 0
1735 */
1736static int smack_sem_alloc_security(struct sem_array *sma)
1737{
1738 struct kern_ipc_perm *isp = &sma->sem_perm;
1739
86a264ab 1740 isp->security = current_security();
e114e473
CS
1741 return 0;
1742}
1743
1744/**
1745 * smack_sem_free_security - Clear the security blob for sem
1746 * @sma: the object
1747 *
1748 * Clears the blob pointer
1749 */
1750static void smack_sem_free_security(struct sem_array *sma)
1751{
1752 struct kern_ipc_perm *isp = &sma->sem_perm;
1753
1754 isp->security = NULL;
1755}
1756
1757/**
1758 * smack_sem_associate - Smack access check for sem
1759 * @sma: the object
1760 * @semflg: access requested
1761 *
1762 * Returns 0 if current has the requested access, error code otherwise
1763 */
1764static int smack_sem_associate(struct sem_array *sma, int semflg)
1765{
1766 char *ssp = smack_of_sem(sma);
1767 int may;
1768
1769 may = smack_flags_to_may(semflg);
1770 return smk_curacc(ssp, may);
1771}
1772
1773/**
1774 * smack_sem_shmctl - Smack access check for sem
1775 * @sma: the object
1776 * @cmd: what it wants to do
1777 *
1778 * Returns 0 if current has the requested access, error code otherwise
1779 */
1780static int smack_sem_semctl(struct sem_array *sma, int cmd)
1781{
1d252fb8 1782 char *ssp;
e114e473
CS
1783 int may;
1784
1785 switch (cmd) {
1786 case GETPID:
1787 case GETNCNT:
1788 case GETZCNT:
1789 case GETVAL:
1790 case GETALL:
1791 case IPC_STAT:
1792 case SEM_STAT:
1793 may = MAY_READ;
1794 break;
1795 case SETVAL:
1796 case SETALL:
1797 case IPC_RMID:
1798 case IPC_SET:
1799 may = MAY_READWRITE;
1800 break;
1801 case IPC_INFO:
1802 case SEM_INFO:
1803 /*
1804 * System level information
1805 */
1806 return 0;
1807 default:
1808 return -EINVAL;
1809 }
1810
1d252fb8 1811 ssp = smack_of_sem(sma);
e114e473
CS
1812 return smk_curacc(ssp, may);
1813}
1814
1815/**
1816 * smack_sem_semop - Smack checks of semaphore operations
1817 * @sma: the object
1818 * @sops: unused
1819 * @nsops: unused
1820 * @alter: unused
1821 *
1822 * Treated as read and write in all cases.
1823 *
1824 * Returns 0 if access is allowed, error code otherwise
1825 */
1826static int smack_sem_semop(struct sem_array *sma, struct sembuf *sops,
1827 unsigned nsops, int alter)
1828{
1829 char *ssp = smack_of_sem(sma);
1830
1831 return smk_curacc(ssp, MAY_READWRITE);
1832}
1833
1834/**
1835 * smack_msg_alloc_security - Set the security blob for msg
1836 * @msq: the object
1837 *
1838 * Returns 0
1839 */
1840static int smack_msg_queue_alloc_security(struct msg_queue *msq)
1841{
1842 struct kern_ipc_perm *kisp = &msq->q_perm;
1843
86a264ab 1844 kisp->security = current_security();
e114e473
CS
1845 return 0;
1846}
1847
1848/**
1849 * smack_msg_free_security - Clear the security blob for msg
1850 * @msq: the object
1851 *
1852 * Clears the blob pointer
1853 */
1854static void smack_msg_queue_free_security(struct msg_queue *msq)
1855{
1856 struct kern_ipc_perm *kisp = &msq->q_perm;
1857
1858 kisp->security = NULL;
1859}
1860
1861/**
1862 * smack_of_msq - the smack pointer for the msq
1863 * @msq: the object
1864 *
1865 * Returns a pointer to the smack value
1866 */
1867static char *smack_of_msq(struct msg_queue *msq)
1868{
1869 return (char *)msq->q_perm.security;
1870}
1871
1872/**
1873 * smack_msg_queue_associate - Smack access check for msg_queue
1874 * @msq: the object
1875 * @msqflg: access requested
1876 *
1877 * Returns 0 if current has the requested access, error code otherwise
1878 */
1879static int smack_msg_queue_associate(struct msg_queue *msq, int msqflg)
1880{
1881 char *msp = smack_of_msq(msq);
1882 int may;
1883
1884 may = smack_flags_to_may(msqflg);
1885 return smk_curacc(msp, may);
1886}
1887
1888/**
1889 * smack_msg_queue_msgctl - Smack access check for msg_queue
1890 * @msq: the object
1891 * @cmd: what it wants to do
1892 *
1893 * Returns 0 if current has the requested access, error code otherwise
1894 */
1895static int smack_msg_queue_msgctl(struct msg_queue *msq, int cmd)
1896{
1d252fb8 1897 char *msp;
e114e473
CS
1898 int may;
1899
1900 switch (cmd) {
1901 case IPC_STAT:
1902 case MSG_STAT:
1903 may = MAY_READ;
1904 break;
1905 case IPC_SET:
1906 case IPC_RMID:
1907 may = MAY_READWRITE;
1908 break;
1909 case IPC_INFO:
1910 case MSG_INFO:
1911 /*
1912 * System level information
1913 */
1914 return 0;
1915 default:
1916 return -EINVAL;
1917 }
1918
1d252fb8 1919 msp = smack_of_msq(msq);
e114e473
CS
1920 return smk_curacc(msp, may);
1921}
1922
1923/**
1924 * smack_msg_queue_msgsnd - Smack access check for msg_queue
1925 * @msq: the object
1926 * @msg: unused
1927 * @msqflg: access requested
1928 *
1929 * Returns 0 if current has the requested access, error code otherwise
1930 */
1931static int smack_msg_queue_msgsnd(struct msg_queue *msq, struct msg_msg *msg,
1932 int msqflg)
1933{
1934 char *msp = smack_of_msq(msq);
1935 int rc;
1936
1937 rc = smack_flags_to_may(msqflg);
1938 return smk_curacc(msp, rc);
1939}
1940
1941/**
1942 * smack_msg_queue_msgsnd - Smack access check for msg_queue
1943 * @msq: the object
1944 * @msg: unused
1945 * @target: unused
1946 * @type: unused
1947 * @mode: unused
1948 *
1949 * Returns 0 if current has read and write access, error code otherwise
1950 */
1951static int smack_msg_queue_msgrcv(struct msg_queue *msq, struct msg_msg *msg,
1952 struct task_struct *target, long type, int mode)
1953{
1954 char *msp = smack_of_msq(msq);
1955
1956 return smk_curacc(msp, MAY_READWRITE);
1957}
1958
1959/**
1960 * smack_ipc_permission - Smack access for ipc_permission()
1961 * @ipp: the object permissions
1962 * @flag: access requested
1963 *
1964 * Returns 0 if current has read and write access, error code otherwise
1965 */
1966static int smack_ipc_permission(struct kern_ipc_perm *ipp, short flag)
1967{
1968 char *isp = ipp->security;
1969 int may;
1970
1971 may = smack_flags_to_may(flag);
1972 return smk_curacc(isp, may);
1973}
1974
d20bdda6
AD
1975/**
1976 * smack_ipc_getsecid - Extract smack security id
1977 * @ipcp: the object permissions
1978 * @secid: where result will be saved
1979 */
1980static void smack_ipc_getsecid(struct kern_ipc_perm *ipp, u32 *secid)
1981{
1982 char *smack = ipp->security;
1983
1984 *secid = smack_to_secid(smack);
1985}
1986
e114e473
CS
1987/**
1988 * smack_d_instantiate - Make sure the blob is correct on an inode
1989 * @opt_dentry: unused
1990 * @inode: the object
1991 *
1992 * Set the inode's security blob if it hasn't been done already.
1993 */
1994static void smack_d_instantiate(struct dentry *opt_dentry, struct inode *inode)
1995{
1996 struct super_block *sbp;
1997 struct superblock_smack *sbsp;
1998 struct inode_smack *isp;
86a264ab 1999 char *csp = current_security();
e114e473
CS
2000 char *fetched;
2001 char *final;
2002 struct dentry *dp;
2003
2004 if (inode == NULL)
2005 return;
2006
2007 isp = inode->i_security;
2008
2009 mutex_lock(&isp->smk_lock);
2010 /*
2011 * If the inode is already instantiated
2012 * take the quick way out
2013 */
2014 if (isp->smk_flags & SMK_INODE_INSTANT)
2015 goto unlockandout;
2016
2017 sbp = inode->i_sb;
2018 sbsp = sbp->s_security;
2019 /*
2020 * We're going to use the superblock default label
2021 * if there's no label on the file.
2022 */
2023 final = sbsp->smk_default;
2024
e97dcb0e
CS
2025 /*
2026 * If this is the root inode the superblock
2027 * may be in the process of initialization.
2028 * If that is the case use the root value out
2029 * of the superblock.
2030 */
2031 if (opt_dentry->d_parent == opt_dentry) {
2032 isp->smk_inode = sbsp->smk_root;
2033 isp->smk_flags |= SMK_INODE_INSTANT;
2034 goto unlockandout;
2035 }
2036
e114e473
CS
2037 /*
2038 * This is pretty hackish.
2039 * Casey says that we shouldn't have to do
2040 * file system specific code, but it does help
2041 * with keeping it simple.
2042 */
2043 switch (sbp->s_magic) {
2044 case SMACK_MAGIC:
2045 /*
2046 * Casey says that it's a little embarassing
2047 * that the smack file system doesn't do
2048 * extended attributes.
2049 */
2050 final = smack_known_star.smk_known;
2051 break;
2052 case PIPEFS_MAGIC:
2053 /*
2054 * Casey says pipes are easy (?)
2055 */
2056 final = smack_known_star.smk_known;
2057 break;
2058 case DEVPTS_SUPER_MAGIC:
2059 /*
2060 * devpts seems content with the label of the task.
2061 * Programs that change smack have to treat the
2062 * pty with respect.
2063 */
2064 final = csp;
2065 break;
2066 case SOCKFS_MAGIC:
2067 /*
2068 * Casey says sockets get the smack of the task.
2069 */
2070 final = csp;
2071 break;
2072 case PROC_SUPER_MAGIC:
2073 /*
2074 * Casey says procfs appears not to care.
2075 * The superblock default suffices.
2076 */
2077 break;
2078 case TMPFS_MAGIC:
2079 /*
2080 * Device labels should come from the filesystem,
2081 * but watch out, because they're volitile,
2082 * getting recreated on every reboot.
2083 */
2084 final = smack_known_star.smk_known;
2085 /*
2086 * No break.
2087 *
2088 * If a smack value has been set we want to use it,
2089 * but since tmpfs isn't giving us the opportunity
2090 * to set mount options simulate setting the
2091 * superblock default.
2092 */
2093 default:
2094 /*
2095 * This isn't an understood special case.
2096 * Get the value from the xattr.
2097 *
2098 * No xattr support means, alas, no SMACK label.
2099 * Use the aforeapplied default.
2100 * It would be curious if the label of the task
2101 * does not match that assigned.
2102 */
2103 if (inode->i_op->getxattr == NULL)
2104 break;
2105 /*
2106 * Get the dentry for xattr.
2107 */
2108 if (opt_dentry == NULL) {
2109 dp = d_find_alias(inode);
2110 if (dp == NULL)
2111 break;
2112 } else {
2113 dp = dget(opt_dentry);
2114 if (dp == NULL)
2115 break;
2116 }
2117
2118 fetched = smk_fetch(inode, dp);
2119 if (fetched != NULL)
2120 final = fetched;
2121
2122 dput(dp);
2123 break;
2124 }
2125
2126 if (final == NULL)
2127 isp->smk_inode = csp;
2128 else
2129 isp->smk_inode = final;
2130
2131 isp->smk_flags |= SMK_INODE_INSTANT;
2132
2133unlockandout:
2134 mutex_unlock(&isp->smk_lock);
2135 return;
2136}
2137
2138/**
2139 * smack_getprocattr - Smack process attribute access
2140 * @p: the object task
2141 * @name: the name of the attribute in /proc/.../attr
2142 * @value: where to put the result
2143 *
2144 * Places a copy of the task Smack into value
2145 *
2146 * Returns the length of the smack label or an error code
2147 */
2148static int smack_getprocattr(struct task_struct *p, char *name, char **value)
2149{
2150 char *cp;
2151 int slen;
2152
2153 if (strcmp(name, "current") != 0)
2154 return -EINVAL;
2155
c69e8d9c 2156 cp = kstrdup(task_security(p), GFP_KERNEL);
e114e473
CS
2157 if (cp == NULL)
2158 return -ENOMEM;
2159
2160 slen = strlen(cp);
2161 *value = cp;
2162 return slen;
2163}
2164
2165/**
2166 * smack_setprocattr - Smack process attribute setting
2167 * @p: the object task
2168 * @name: the name of the attribute in /proc/.../attr
2169 * @value: the value to set
2170 * @size: the size of the value
2171 *
2172 * Sets the Smack value of the task. Only setting self
2173 * is permitted and only with privilege
2174 *
2175 * Returns the length of the smack label or an error code
2176 */
2177static int smack_setprocattr(struct task_struct *p, char *name,
2178 void *value, size_t size)
2179{
d84f4f99 2180 struct cred *new;
e114e473
CS
2181 char *newsmack;
2182
e114e473
CS
2183 /*
2184 * Changing another process' Smack value is too dangerous
2185 * and supports no sane use case.
2186 */
2187 if (p != current)
2188 return -EPERM;
2189
5cd9c58f
DH
2190 if (!capable(CAP_MAC_ADMIN))
2191 return -EPERM;
2192
e114e473
CS
2193 if (value == NULL || size == 0 || size >= SMK_LABELLEN)
2194 return -EINVAL;
2195
2196 if (strcmp(name, "current") != 0)
2197 return -EINVAL;
2198
2199 newsmack = smk_import(value, size);
2200 if (newsmack == NULL)
2201 return -EINVAL;
2202
6d3dc07c
CS
2203 /*
2204 * No process is ever allowed the web ("@") label.
2205 */
2206 if (newsmack == smack_known_web.smk_known)
2207 return -EPERM;
2208
d84f4f99 2209 new = prepare_creds();
6d3dc07c 2210 if (new == NULL)
d84f4f99
DH
2211 return -ENOMEM;
2212 new->security = newsmack;
2213 commit_creds(new);
e114e473
CS
2214 return size;
2215}
2216
2217/**
2218 * smack_unix_stream_connect - Smack access on UDS
2219 * @sock: one socket
2220 * @other: the other socket
2221 * @newsk: unused
2222 *
2223 * Return 0 if a subject with the smack of sock could access
2224 * an object with the smack of other, otherwise an error code
2225 */
2226static int smack_unix_stream_connect(struct socket *sock,
2227 struct socket *other, struct sock *newsk)
2228{
2229 struct inode *sp = SOCK_INODE(sock);
2230 struct inode *op = SOCK_INODE(other);
2231
2232 return smk_access(smk_of_inode(sp), smk_of_inode(op), MAY_READWRITE);
2233}
2234
2235/**
2236 * smack_unix_may_send - Smack access on UDS
2237 * @sock: one socket
2238 * @other: the other socket
2239 *
2240 * Return 0 if a subject with the smack of sock could access
2241 * an object with the smack of other, otherwise an error code
2242 */
2243static int smack_unix_may_send(struct socket *sock, struct socket *other)
2244{
2245 struct inode *sp = SOCK_INODE(sock);
2246 struct inode *op = SOCK_INODE(other);
2247
2248 return smk_access(smk_of_inode(sp), smk_of_inode(op), MAY_WRITE);
2249}
2250
6d3dc07c
CS
2251/**
2252 * smack_socket_sendmsg - Smack check based on destination host
2253 * @sock: the socket
2254 * @msghdr: the message
2255 * @size: the size of the message
2256 *
2257 * Return 0 if the current subject can write to the destination
2258 * host. This is only a question if the destination is a single
2259 * label host.
2260 */
2261static int smack_socket_sendmsg(struct socket *sock, struct msghdr *msg,
2262 int size)
2263{
2264 struct sockaddr_in *sip = (struct sockaddr_in *) msg->msg_name;
2265 struct socket_smack *ssp = sock->sk->sk_security;
2266 char *hostsp;
2267 int rc;
2268
2269 /*
2270 * Perfectly reasonable for this to be NULL
2271 */
2272 if (sip == NULL || sip->sin_family != PF_INET)
2273 return 0;
2274
2275 hostsp = smack_host_label(sip);
2276 if (hostsp == NULL) {
2277 if (ssp->smk_labeled != SMACK_CIPSO_SOCKET)
2278 return smack_netlabel(sock->sk, SMACK_CIPSO_SOCKET);
2279 return 0;
2280 }
2281
2282 rc = smk_access(ssp->smk_out, hostsp, MAY_WRITE);
2283 if (rc != 0)
2284 return rc;
2285
2286 if (ssp->smk_labeled != SMACK_UNLABELED_SOCKET)
2287 return smack_netlabel(sock->sk, SMACK_UNLABELED_SOCKET);
2288
2289 return 0;
2290
2291}
2292
2293
e114e473
CS
2294/**
2295 * smack_from_secattr - Convert a netlabel attr.mls.lvl/attr.mls.cat
2296 * pair to smack
2297 * @sap: netlabel secattr
2298 * @sip: where to put the result
2299 *
2300 * Copies a smack label into sip
2301 */
2302static void smack_from_secattr(struct netlbl_lsm_secattr *sap, char *sip)
2303{
2304 char smack[SMK_LABELLEN];
6d3dc07c 2305 char *sp;
e114e473
CS
2306 int pcat;
2307
6d3dc07c 2308 if ((sap->flags & NETLBL_SECATTR_MLS_LVL) != 0) {
e114e473 2309 /*
6d3dc07c 2310 * Looks like a CIPSO packet.
e114e473
CS
2311 * If there are flags but no level netlabel isn't
2312 * behaving the way we expect it to.
2313 *
6d3dc07c 2314 * Get the categories, if any
e114e473
CS
2315 * Without guidance regarding the smack value
2316 * for the packet fall back on the network
2317 * ambient value.
2318 */
6d3dc07c
CS
2319 memset(smack, '\0', SMK_LABELLEN);
2320 if ((sap->flags & NETLBL_SECATTR_MLS_CAT) != 0)
2321 for (pcat = -1;;) {
2322 pcat = netlbl_secattr_catmap_walk(
2323 sap->attr.mls.cat, pcat + 1);
2324 if (pcat < 0)
2325 break;
2326 smack_catset_bit(pcat, smack);
2327 }
2328 /*
2329 * If it is CIPSO using smack direct mapping
2330 * we are already done. WeeHee.
2331 */
2332 if (sap->attr.mls.lvl == smack_cipso_direct) {
2333 memcpy(sip, smack, SMK_MAXLEN);
2334 return;
2335 }
2336 /*
2337 * Look it up in the supplied table if it is not
2338 * a direct mapping.
2339 */
2340 smack_from_cipso(sap->attr.mls.lvl, smack, sip);
e114e473
CS
2341 return;
2342 }
6d3dc07c
CS
2343 if ((sap->flags & NETLBL_SECATTR_SECID) != 0) {
2344 /*
2345 * Looks like a fallback, which gives us a secid.
2346 */
2347 sp = smack_from_secid(sap->attr.secid);
2348 /*
2349 * This has got to be a bug because it is
2350 * impossible to specify a fallback without
2351 * specifying the label, which will ensure
2352 * it has a secid, and the only way to get a
2353 * secid is from a fallback.
2354 */
2355 BUG_ON(sp == NULL);
2356 strncpy(sip, sp, SMK_MAXLEN);
e114e473
CS
2357 return;
2358 }
2359 /*
6d3dc07c
CS
2360 * Without guidance regarding the smack value
2361 * for the packet fall back on the network
2362 * ambient value.
e114e473 2363 */
6d3dc07c 2364 strncpy(sip, smack_net_ambient, SMK_MAXLEN);
e114e473
CS
2365 return;
2366}
2367
2368/**
2369 * smack_socket_sock_rcv_skb - Smack packet delivery access check
2370 * @sk: socket
2371 * @skb: packet
2372 *
2373 * Returns 0 if the packet should be delivered, an error code otherwise
2374 */
2375static int smack_socket_sock_rcv_skb(struct sock *sk, struct sk_buff *skb)
2376{
2377 struct netlbl_lsm_secattr secattr;
2378 struct socket_smack *ssp = sk->sk_security;
2379 char smack[SMK_LABELLEN];
6d3dc07c 2380 char *csp;
e114e473
CS
2381 int rc;
2382
2383 if (sk->sk_family != PF_INET && sk->sk_family != PF_INET6)
2384 return 0;
2385
2386 /*
2387 * Translate what netlabel gave us.
2388 */
e114e473 2389 netlbl_secattr_init(&secattr);
6d3dc07c 2390
e114e473 2391 rc = netlbl_skbuff_getattr(skb, sk->sk_family, &secattr);
6d3dc07c 2392 if (rc == 0) {
e114e473 2393 smack_from_secattr(&secattr, smack);
6d3dc07c
CS
2394 csp = smack;
2395 } else
2396 csp = smack_net_ambient;
2397
e114e473 2398 netlbl_secattr_destroy(&secattr);
6d3dc07c 2399
e114e473
CS
2400 /*
2401 * Receiving a packet requires that the other end
2402 * be able to write here. Read access is not required.
2403 * This is the simplist possible security model
2404 * for networking.
2405 */
6d3dc07c 2406 rc = smk_access(csp, ssp->smk_in, MAY_WRITE);
a8134296
PM
2407 if (rc != 0)
2408 netlbl_skbuff_err(skb, rc, 0);
2409 return rc;
e114e473
CS
2410}
2411
2412/**
2413 * smack_socket_getpeersec_stream - pull in packet label
2414 * @sock: the socket
2415 * @optval: user's destination
2416 * @optlen: size thereof
2417 * @len: max thereoe
2418 *
2419 * returns zero on success, an error code otherwise
2420 */
2421static int smack_socket_getpeersec_stream(struct socket *sock,
2422 char __user *optval,
2423 int __user *optlen, unsigned len)
2424{
2425 struct socket_smack *ssp;
2426 int slen;
2427 int rc = 0;
2428
2429 ssp = sock->sk->sk_security;
2430 slen = strlen(ssp->smk_packet) + 1;
2431
2432 if (slen > len)
2433 rc = -ERANGE;
2434 else if (copy_to_user(optval, ssp->smk_packet, slen) != 0)
2435 rc = -EFAULT;
2436
2437 if (put_user(slen, optlen) != 0)
2438 rc = -EFAULT;
2439
2440 return rc;
2441}
2442
2443
2444/**
2445 * smack_socket_getpeersec_dgram - pull in packet label
2446 * @sock: the socket
2447 * @skb: packet data
2448 * @secid: pointer to where to put the secid of the packet
2449 *
2450 * Sets the netlabel socket state on sk from parent
2451 */
2452static int smack_socket_getpeersec_dgram(struct socket *sock,
2453 struct sk_buff *skb, u32 *secid)
2454
2455{
2456 struct netlbl_lsm_secattr secattr;
2457 struct sock *sk;
2458 char smack[SMK_LABELLEN];
2459 int family = PF_INET;
2460 u32 s;
2461 int rc;
2462
2463 /*
2464 * Only works for families with packets.
2465 */
2466 if (sock != NULL) {
2467 sk = sock->sk;
2468 if (sk->sk_family != PF_INET && sk->sk_family != PF_INET6)
2469 return 0;
2470 family = sk->sk_family;
2471 }
2472 /*
2473 * Translate what netlabel gave us.
2474 */
e114e473
CS
2475 netlbl_secattr_init(&secattr);
2476 rc = netlbl_skbuff_getattr(skb, family, &secattr);
2477 if (rc == 0)
2478 smack_from_secattr(&secattr, smack);
2479 netlbl_secattr_destroy(&secattr);
2480
2481 /*
2482 * Give up if we couldn't get anything
2483 */
2484 if (rc != 0)
2485 return rc;
2486
2487 s = smack_to_secid(smack);
2488 if (s == 0)
2489 return -EINVAL;
2490
2491 *secid = s;
2492 return 0;
2493}
2494
2495/**
2496 * smack_sock_graft - graft access state between two sockets
2497 * @sk: fresh sock
2498 * @parent: donor socket
2499 *
2500 * Sets the netlabel socket state on sk from parent
2501 */
2502static void smack_sock_graft(struct sock *sk, struct socket *parent)
2503{
2504 struct socket_smack *ssp;
2505 int rc;
2506
2507 if (sk == NULL)
2508 return;
2509
2510 if (sk->sk_family != PF_INET && sk->sk_family != PF_INET6)
2511 return;
2512
2513 ssp = sk->sk_security;
86a264ab 2514 ssp->smk_in = ssp->smk_out = current_security();
e114e473
CS
2515 ssp->smk_packet[0] = '\0';
2516
6d3dc07c 2517 rc = smack_netlabel(sk, SMACK_CIPSO_SOCKET);
4bc87e62
CS
2518 if (rc != 0)
2519 printk(KERN_WARNING "Smack: \"%s\" netlbl error %d.\n",
2520 __func__, -rc);
e114e473
CS
2521}
2522
2523/**
2524 * smack_inet_conn_request - Smack access check on connect
2525 * @sk: socket involved
2526 * @skb: packet
2527 * @req: unused
2528 *
2529 * Returns 0 if a task with the packet label could write to
2530 * the socket, otherwise an error code
2531 */
2532static int smack_inet_conn_request(struct sock *sk, struct sk_buff *skb,
2533 struct request_sock *req)
2534{
2535 struct netlbl_lsm_secattr skb_secattr;
2536 struct socket_smack *ssp = sk->sk_security;
2537 char smack[SMK_LABELLEN];
2538 int rc;
2539
2540 if (skb == NULL)
2541 return -EACCES;
2542
e114e473
CS
2543 netlbl_secattr_init(&skb_secattr);
2544 rc = netlbl_skbuff_getattr(skb, sk->sk_family, &skb_secattr);
2545 if (rc == 0)
2546 smack_from_secattr(&skb_secattr, smack);
2547 else
2548 strncpy(smack, smack_known_huh.smk_known, SMK_MAXLEN);
2549 netlbl_secattr_destroy(&skb_secattr);
2550 /*
2551 * Receiving a packet requires that the other end
2552 * be able to write here. Read access is not required.
2553 *
2554 * If the request is successful save the peer's label
2555 * so that SO_PEERCRED can report it.
2556 */
2557 rc = smk_access(smack, ssp->smk_in, MAY_WRITE);
2558 if (rc == 0)
2559 strncpy(ssp->smk_packet, smack, SMK_MAXLEN);
2560
2561 return rc;
2562}
2563
2564/*
2565 * Key management security hooks
2566 *
2567 * Casey has not tested key support very heavily.
2568 * The permission check is most likely too restrictive.
2569 * If you care about keys please have a look.
2570 */
2571#ifdef CONFIG_KEYS
2572
2573/**
2574 * smack_key_alloc - Set the key security blob
2575 * @key: object
d84f4f99 2576 * @cred: the credentials to use
e114e473
CS
2577 * @flags: unused
2578 *
2579 * No allocation required
2580 *
2581 * Returns 0
2582 */
d84f4f99 2583static int smack_key_alloc(struct key *key, const struct cred *cred,
e114e473
CS
2584 unsigned long flags)
2585{
d84f4f99 2586 key->security = cred->security;
e114e473
CS
2587 return 0;
2588}
2589
2590/**
2591 * smack_key_free - Clear the key security blob
2592 * @key: the object
2593 *
2594 * Clear the blob pointer
2595 */
2596static void smack_key_free(struct key *key)
2597{
2598 key->security = NULL;
2599}
2600
2601/*
2602 * smack_key_permission - Smack access on a key
2603 * @key_ref: gets to the object
d84f4f99 2604 * @cred: the credentials to use
e114e473
CS
2605 * @perm: unused
2606 *
2607 * Return 0 if the task has read and write to the object,
2608 * an error code otherwise
2609 */
2610static int smack_key_permission(key_ref_t key_ref,
d84f4f99 2611 const struct cred *cred, key_perm_t perm)
e114e473
CS
2612{
2613 struct key *keyp;
2614
2615 keyp = key_ref_to_ptr(key_ref);
2616 if (keyp == NULL)
2617 return -EINVAL;
2618 /*
2619 * If the key hasn't been initialized give it access so that
2620 * it may do so.
2621 */
2622 if (keyp->security == NULL)
2623 return 0;
2624 /*
2625 * This should not occur
2626 */
d84f4f99 2627 if (cred->security == NULL)
e114e473
CS
2628 return -EACCES;
2629
d84f4f99 2630 return smk_access(cred->security, keyp->security, MAY_READWRITE);
e114e473
CS
2631}
2632#endif /* CONFIG_KEYS */
2633
d20bdda6
AD
2634/*
2635 * Smack Audit hooks
2636 *
2637 * Audit requires a unique representation of each Smack specific
2638 * rule. This unique representation is used to distinguish the
2639 * object to be audited from remaining kernel objects and also
2640 * works as a glue between the audit hooks.
2641 *
2642 * Since repository entries are added but never deleted, we'll use
2643 * the smack_known label address related to the given audit rule as
2644 * the needed unique representation. This also better fits the smack
2645 * model where nearly everything is a label.
2646 */
2647#ifdef CONFIG_AUDIT
2648
2649/**
2650 * smack_audit_rule_init - Initialize a smack audit rule
2651 * @field: audit rule fields given from user-space (audit.h)
2652 * @op: required testing operator (=, !=, >, <, ...)
2653 * @rulestr: smack label to be audited
2654 * @vrule: pointer to save our own audit rule representation
2655 *
2656 * Prepare to audit cases where (@field @op @rulestr) is true.
2657 * The label to be audited is created if necessay.
2658 */
2659static int smack_audit_rule_init(u32 field, u32 op, char *rulestr, void **vrule)
2660{
2661 char **rule = (char **)vrule;
2662 *rule = NULL;
2663
2664 if (field != AUDIT_SUBJ_USER && field != AUDIT_OBJ_USER)
2665 return -EINVAL;
2666
5af75d8d 2667 if (op != Audit_equal && op != Audit_not_equal)
d20bdda6
AD
2668 return -EINVAL;
2669
2670 *rule = smk_import(rulestr, 0);
2671
2672 return 0;
2673}
2674
2675/**
2676 * smack_audit_rule_known - Distinguish Smack audit rules
2677 * @krule: rule of interest, in Audit kernel representation format
2678 *
2679 * This is used to filter Smack rules from remaining Audit ones.
2680 * If it's proved that this rule belongs to us, the
2681 * audit_rule_match hook will be called to do the final judgement.
2682 */
2683static int smack_audit_rule_known(struct audit_krule *krule)
2684{
2685 struct audit_field *f;
2686 int i;
2687
2688 for (i = 0; i < krule->field_count; i++) {
2689 f = &krule->fields[i];
2690
2691 if (f->type == AUDIT_SUBJ_USER || f->type == AUDIT_OBJ_USER)
2692 return 1;
2693 }
2694
2695 return 0;
2696}
2697
2698/**
2699 * smack_audit_rule_match - Audit given object ?
2700 * @secid: security id for identifying the object to test
2701 * @field: audit rule flags given from user-space
2702 * @op: required testing operator
2703 * @vrule: smack internal rule presentation
2704 * @actx: audit context associated with the check
2705 *
2706 * The core Audit hook. It's used to take the decision of
2707 * whether to audit or not to audit a given object.
2708 */
2709static int smack_audit_rule_match(u32 secid, u32 field, u32 op, void *vrule,
2710 struct audit_context *actx)
2711{
2712 char *smack;
2713 char *rule = vrule;
2714
2715 if (!rule) {
2716 audit_log(actx, GFP_KERNEL, AUDIT_SELINUX_ERR,
2717 "Smack: missing rule\n");
2718 return -ENOENT;
2719 }
2720
2721 if (field != AUDIT_SUBJ_USER && field != AUDIT_OBJ_USER)
2722 return 0;
2723
2724 smack = smack_from_secid(secid);
2725
2726 /*
2727 * No need to do string comparisons. If a match occurs,
2728 * both pointers will point to the same smack_known
2729 * label.
2730 */
5af75d8d 2731 if (op == Audit_equal)
d20bdda6 2732 return (rule == smack);
5af75d8d 2733 if (op == Audit_not_equal)
d20bdda6
AD
2734 return (rule != smack);
2735
2736 return 0;
2737}
2738
2739/**
2740 * smack_audit_rule_free - free smack rule representation
2741 * @vrule: rule to be freed.
2742 *
2743 * No memory was allocated.
2744 */
2745static void smack_audit_rule_free(void *vrule)
2746{
2747 /* No-op */
2748}
2749
2750#endif /* CONFIG_AUDIT */
2751
e114e473
CS
2752/*
2753 * smack_secid_to_secctx - return the smack label for a secid
2754 * @secid: incoming integer
2755 * @secdata: destination
2756 * @seclen: how long it is
2757 *
2758 * Exists for networking code.
2759 */
2760static int smack_secid_to_secctx(u32 secid, char **secdata, u32 *seclen)
2761{
2762 char *sp = smack_from_secid(secid);
2763
2764 *secdata = sp;
2765 *seclen = strlen(sp);
2766 return 0;
2767}
2768
4bc87e62
CS
2769/*
2770 * smack_secctx_to_secid - return the secid for a smack label
2771 * @secdata: smack label
2772 * @seclen: how long result is
2773 * @secid: outgoing integer
2774 *
2775 * Exists for audit and networking code.
2776 */
e52c1764 2777static int smack_secctx_to_secid(const char *secdata, u32 seclen, u32 *secid)
4bc87e62
CS
2778{
2779 *secid = smack_to_secid(secdata);
2780 return 0;
2781}
2782
e114e473
CS
2783/*
2784 * smack_release_secctx - don't do anything.
2785 * @key_ref: unused
2786 * @context: unused
2787 * @perm: unused
2788 *
2789 * Exists to make sure nothing gets done, and properly
2790 */
2791static void smack_release_secctx(char *secdata, u32 seclen)
2792{
2793}
2794
076c54c5
AD
2795struct security_operations smack_ops = {
2796 .name = "smack",
2797
5cd9c58f
DH
2798 .ptrace_may_access = smack_ptrace_may_access,
2799 .ptrace_traceme = smack_ptrace_traceme,
e114e473 2800 .capget = cap_capget,
d84f4f99 2801 .capset = cap_capset,
e114e473
CS
2802 .capable = cap_capable,
2803 .syslog = smack_syslog,
2804 .settime = cap_settime,
2805 .vm_enough_memory = cap_vm_enough_memory,
2806
a6f76f23 2807 .bprm_set_creds = cap_bprm_set_creds,
e114e473
CS
2808 .bprm_secureexec = cap_bprm_secureexec,
2809
2810 .sb_alloc_security = smack_sb_alloc_security,
2811 .sb_free_security = smack_sb_free_security,
2812 .sb_copy_data = smack_sb_copy_data,
2813 .sb_kern_mount = smack_sb_kern_mount,
2814 .sb_statfs = smack_sb_statfs,
2815 .sb_mount = smack_sb_mount,
2816 .sb_umount = smack_sb_umount,
2817
2818 .inode_alloc_security = smack_inode_alloc_security,
2819 .inode_free_security = smack_inode_free_security,
2820 .inode_init_security = smack_inode_init_security,
2821 .inode_link = smack_inode_link,
2822 .inode_unlink = smack_inode_unlink,
2823 .inode_rmdir = smack_inode_rmdir,
2824 .inode_rename = smack_inode_rename,
2825 .inode_permission = smack_inode_permission,
2826 .inode_setattr = smack_inode_setattr,
2827 .inode_getattr = smack_inode_getattr,
2828 .inode_setxattr = smack_inode_setxattr,
2829 .inode_post_setxattr = smack_inode_post_setxattr,
2830 .inode_getxattr = smack_inode_getxattr,
2831 .inode_removexattr = smack_inode_removexattr,
bcdca225
CS
2832 .inode_need_killpriv = cap_inode_need_killpriv,
2833 .inode_killpriv = cap_inode_killpriv,
e114e473
CS
2834 .inode_getsecurity = smack_inode_getsecurity,
2835 .inode_setsecurity = smack_inode_setsecurity,
2836 .inode_listsecurity = smack_inode_listsecurity,
d20bdda6 2837 .inode_getsecid = smack_inode_getsecid,
e114e473
CS
2838
2839 .file_permission = smack_file_permission,
2840 .file_alloc_security = smack_file_alloc_security,
2841 .file_free_security = smack_file_free_security,
2842 .file_ioctl = smack_file_ioctl,
2843 .file_lock = smack_file_lock,
2844 .file_fcntl = smack_file_fcntl,
2845 .file_set_fowner = smack_file_set_fowner,
2846 .file_send_sigiotask = smack_file_send_sigiotask,
2847 .file_receive = smack_file_receive,
2848
f1752eec 2849 .cred_free = smack_cred_free,
d84f4f99
DH
2850 .cred_prepare = smack_cred_prepare,
2851 .cred_commit = smack_cred_commit,
3a3b7ce9
DH
2852 .kernel_act_as = smack_kernel_act_as,
2853 .kernel_create_files_as = smack_kernel_create_files_as,
d84f4f99 2854 .task_fix_setuid = cap_task_fix_setuid,
e114e473
CS
2855 .task_setpgid = smack_task_setpgid,
2856 .task_getpgid = smack_task_getpgid,
2857 .task_getsid = smack_task_getsid,
2858 .task_getsecid = smack_task_getsecid,
2859 .task_setnice = smack_task_setnice,
2860 .task_setioprio = smack_task_setioprio,
2861 .task_getioprio = smack_task_getioprio,
2862 .task_setscheduler = smack_task_setscheduler,
2863 .task_getscheduler = smack_task_getscheduler,
2864 .task_movememory = smack_task_movememory,
2865 .task_kill = smack_task_kill,
2866 .task_wait = smack_task_wait,
e114e473 2867 .task_to_inode = smack_task_to_inode,
1236cc3c 2868 .task_prctl = cap_task_prctl,
e114e473
CS
2869
2870 .ipc_permission = smack_ipc_permission,
d20bdda6 2871 .ipc_getsecid = smack_ipc_getsecid,
e114e473
CS
2872
2873 .msg_msg_alloc_security = smack_msg_msg_alloc_security,
2874 .msg_msg_free_security = smack_msg_msg_free_security,
2875
2876 .msg_queue_alloc_security = smack_msg_queue_alloc_security,
2877 .msg_queue_free_security = smack_msg_queue_free_security,
2878 .msg_queue_associate = smack_msg_queue_associate,
2879 .msg_queue_msgctl = smack_msg_queue_msgctl,
2880 .msg_queue_msgsnd = smack_msg_queue_msgsnd,
2881 .msg_queue_msgrcv = smack_msg_queue_msgrcv,
2882
2883 .shm_alloc_security = smack_shm_alloc_security,
2884 .shm_free_security = smack_shm_free_security,
2885 .shm_associate = smack_shm_associate,
2886 .shm_shmctl = smack_shm_shmctl,
2887 .shm_shmat = smack_shm_shmat,
2888
2889 .sem_alloc_security = smack_sem_alloc_security,
2890 .sem_free_security = smack_sem_free_security,
2891 .sem_associate = smack_sem_associate,
2892 .sem_semctl = smack_sem_semctl,
2893 .sem_semop = smack_sem_semop,
2894
2895 .netlink_send = cap_netlink_send,
2896 .netlink_recv = cap_netlink_recv,
2897
2898 .d_instantiate = smack_d_instantiate,
2899
2900 .getprocattr = smack_getprocattr,
2901 .setprocattr = smack_setprocattr,
2902
2903 .unix_stream_connect = smack_unix_stream_connect,
2904 .unix_may_send = smack_unix_may_send,
2905
2906 .socket_post_create = smack_socket_post_create,
6d3dc07c
CS
2907 .socket_connect = smack_socket_connect,
2908 .socket_sendmsg = smack_socket_sendmsg,
e114e473
CS
2909 .socket_sock_rcv_skb = smack_socket_sock_rcv_skb,
2910 .socket_getpeersec_stream = smack_socket_getpeersec_stream,
2911 .socket_getpeersec_dgram = smack_socket_getpeersec_dgram,
2912 .sk_alloc_security = smack_sk_alloc_security,
2913 .sk_free_security = smack_sk_free_security,
2914 .sock_graft = smack_sock_graft,
2915 .inet_conn_request = smack_inet_conn_request,
d20bdda6 2916
e114e473
CS
2917 /* key management security hooks */
2918#ifdef CONFIG_KEYS
2919 .key_alloc = smack_key_alloc,
2920 .key_free = smack_key_free,
2921 .key_permission = smack_key_permission,
2922#endif /* CONFIG_KEYS */
d20bdda6
AD
2923
2924 /* Audit hooks */
2925#ifdef CONFIG_AUDIT
2926 .audit_rule_init = smack_audit_rule_init,
2927 .audit_rule_known = smack_audit_rule_known,
2928 .audit_rule_match = smack_audit_rule_match,
2929 .audit_rule_free = smack_audit_rule_free,
2930#endif /* CONFIG_AUDIT */
2931
e114e473 2932 .secid_to_secctx = smack_secid_to_secctx,
4bc87e62 2933 .secctx_to_secid = smack_secctx_to_secid,
e114e473
CS
2934 .release_secctx = smack_release_secctx,
2935};
2936
2937/**
2938 * smack_init - initialize the smack system
2939 *
2940 * Returns 0
2941 */
2942static __init int smack_init(void)
2943{
d84f4f99
DH
2944 struct cred *cred;
2945
076c54c5
AD
2946 if (!security_module_enable(&smack_ops))
2947 return 0;
2948
e114e473
CS
2949 printk(KERN_INFO "Smack: Initializing.\n");
2950
2951 /*
2952 * Set the security state for the initial task.
2953 */
d84f4f99
DH
2954 cred = (struct cred *) current->cred;
2955 cred->security = &smack_known_floor.smk_known;
e114e473
CS
2956
2957 /*
2958 * Initialize locks
2959 */
e114e473
CS
2960 spin_lock_init(&smack_known_huh.smk_cipsolock);
2961 spin_lock_init(&smack_known_hat.smk_cipsolock);
2962 spin_lock_init(&smack_known_star.smk_cipsolock);
2963 spin_lock_init(&smack_known_floor.smk_cipsolock);
2964 spin_lock_init(&smack_known_invalid.smk_cipsolock);
2965
2966 /*
2967 * Register with LSM
2968 */
2969 if (register_security(&smack_ops))
2970 panic("smack: Unable to register with kernel.\n");
2971
2972 return 0;
2973}
2974
2975/*
2976 * Smack requires early initialization in order to label
2977 * all processes and objects when they are created.
2978 */
2979security_initcall(smack_init);
This page took 0.230291 seconds and 5 git commands to generate.