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1 /*
2 * Simplified MAC Kernel (smack) security module
3 *
4 * This file contains the smack hook function implementations.
5 *
6 * Authors:
7 * Casey Schaufler <casey@schaufler-ca.com>
8 * Jarkko Sakkinen <ext-jarkko.2.sakkinen@nokia.com>
9 *
10 * Copyright (C) 2007 Casey Schaufler <casey@schaufler-ca.com>
11 * Copyright (C) 2009 Hewlett-Packard Development Company, L.P.
12 * Paul Moore <paul.moore@hp.com>
13 * Copyright (C) 2010 Nokia Corporation
14 *
15 * This program is free software; you can redistribute it and/or modify
16 * it under the terms of the GNU General Public License version 2,
17 * as published by the Free Software Foundation.
18 */
19
20 #include <linux/xattr.h>
21 #include <linux/pagemap.h>
22 #include <linux/mount.h>
23 #include <linux/stat.h>
24 #include <linux/kd.h>
25 #include <asm/ioctls.h>
26 #include <linux/ip.h>
27 #include <linux/tcp.h>
28 #include <linux/udp.h>
29 #include <linux/slab.h>
30 #include <linux/mutex.h>
31 #include <linux/pipe_fs_i.h>
32 #include <net/netlabel.h>
33 #include <net/cipso_ipv4.h>
34 #include <linux/audit.h>
35 #include <linux/magic.h>
36 #include <linux/dcache.h>
37 #include "smack.h"
38
39 #define task_security(task) (task_cred_xxx((task), security))
40
41 #define TRANS_TRUE "TRUE"
42 #define TRANS_TRUE_SIZE 4
43
44 /**
45 * smk_fetch - Fetch the smack label from a file.
46 * @ip: a pointer to the inode
47 * @dp: a pointer to the dentry
48 *
49 * Returns a pointer to the master list entry for the Smack label
50 * or NULL if there was no label to fetch.
51 */
52 static char *smk_fetch(const char *name, struct inode *ip, struct dentry *dp)
53 {
54 int rc;
55 char in[SMK_LABELLEN];
56
57 if (ip->i_op->getxattr == NULL)
58 return NULL;
59
60 rc = ip->i_op->getxattr(dp, name, in, SMK_LABELLEN);
61 if (rc < 0)
62 return NULL;
63
64 return smk_import(in, rc);
65 }
66
67 /**
68 * new_inode_smack - allocate an inode security blob
69 * @smack: a pointer to the Smack label to use in the blob
70 *
71 * Returns the new blob or NULL if there's no memory available
72 */
73 struct inode_smack *new_inode_smack(char *smack)
74 {
75 struct inode_smack *isp;
76
77 isp = kzalloc(sizeof(struct inode_smack), GFP_KERNEL);
78 if (isp == NULL)
79 return NULL;
80
81 isp->smk_inode = smack;
82 isp->smk_flags = 0;
83 mutex_init(&isp->smk_lock);
84
85 return isp;
86 }
87
88 /**
89 * new_task_smack - allocate a task security blob
90 * @smack: a pointer to the Smack label to use in the blob
91 *
92 * Returns the new blob or NULL if there's no memory available
93 */
94 static struct task_smack *new_task_smack(char *task, char *forked, gfp_t gfp)
95 {
96 struct task_smack *tsp;
97
98 tsp = kzalloc(sizeof(struct task_smack), gfp);
99 if (tsp == NULL)
100 return NULL;
101
102 tsp->smk_task = task;
103 tsp->smk_forked = forked;
104 INIT_LIST_HEAD(&tsp->smk_rules);
105 mutex_init(&tsp->smk_rules_lock);
106
107 return tsp;
108 }
109
110 /**
111 * smk_copy_rules - copy a rule set
112 * @nhead - new rules header pointer
113 * @ohead - old rules header pointer
114 *
115 * Returns 0 on success, -ENOMEM on error
116 */
117 static int smk_copy_rules(struct list_head *nhead, struct list_head *ohead,
118 gfp_t gfp)
119 {
120 struct smack_rule *nrp;
121 struct smack_rule *orp;
122 int rc = 0;
123
124 INIT_LIST_HEAD(nhead);
125
126 list_for_each_entry_rcu(orp, ohead, list) {
127 nrp = kzalloc(sizeof(struct smack_rule), gfp);
128 if (nrp == NULL) {
129 rc = -ENOMEM;
130 break;
131 }
132 *nrp = *orp;
133 list_add_rcu(&nrp->list, nhead);
134 }
135 return rc;
136 }
137
138 /*
139 * LSM hooks.
140 * We he, that is fun!
141 */
142
143 /**
144 * smack_ptrace_access_check - Smack approval on PTRACE_ATTACH
145 * @ctp: child task pointer
146 * @mode: ptrace attachment mode
147 *
148 * Returns 0 if access is OK, an error code otherwise
149 *
150 * Do the capability checks, and require read and write.
151 */
152 static int smack_ptrace_access_check(struct task_struct *ctp, unsigned int mode)
153 {
154 int rc;
155 struct smk_audit_info ad;
156 char *tsp;
157
158 rc = cap_ptrace_access_check(ctp, mode);
159 if (rc != 0)
160 return rc;
161
162 tsp = smk_of_task(task_security(ctp));
163 smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_TASK);
164 smk_ad_setfield_u_tsk(&ad, ctp);
165
166 rc = smk_curacc(tsp, MAY_READWRITE, &ad);
167 return rc;
168 }
169
170 /**
171 * smack_ptrace_traceme - Smack approval on PTRACE_TRACEME
172 * @ptp: parent task pointer
173 *
174 * Returns 0 if access is OK, an error code otherwise
175 *
176 * Do the capability checks, and require read and write.
177 */
178 static int smack_ptrace_traceme(struct task_struct *ptp)
179 {
180 int rc;
181 struct smk_audit_info ad;
182 char *tsp;
183
184 rc = cap_ptrace_traceme(ptp);
185 if (rc != 0)
186 return rc;
187
188 tsp = smk_of_task(task_security(ptp));
189 smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_TASK);
190 smk_ad_setfield_u_tsk(&ad, ptp);
191
192 rc = smk_curacc(tsp, MAY_READWRITE, &ad);
193 return rc;
194 }
195
196 /**
197 * smack_syslog - Smack approval on syslog
198 * @type: message type
199 *
200 * Require that the task has the floor label
201 *
202 * Returns 0 on success, error code otherwise.
203 */
204 static int smack_syslog(int typefrom_file)
205 {
206 int rc = 0;
207 char *sp = smk_of_current();
208
209 if (capable(CAP_MAC_OVERRIDE))
210 return 0;
211
212 if (sp != smack_known_floor.smk_known)
213 rc = -EACCES;
214
215 return rc;
216 }
217
218
219 /*
220 * Superblock Hooks.
221 */
222
223 /**
224 * smack_sb_alloc_security - allocate a superblock blob
225 * @sb: the superblock getting the blob
226 *
227 * Returns 0 on success or -ENOMEM on error.
228 */
229 static int smack_sb_alloc_security(struct super_block *sb)
230 {
231 struct superblock_smack *sbsp;
232
233 sbsp = kzalloc(sizeof(struct superblock_smack), GFP_KERNEL);
234
235 if (sbsp == NULL)
236 return -ENOMEM;
237
238 sbsp->smk_root = smack_known_floor.smk_known;
239 sbsp->smk_default = smack_known_floor.smk_known;
240 sbsp->smk_floor = smack_known_floor.smk_known;
241 sbsp->smk_hat = smack_known_hat.smk_known;
242 sbsp->smk_initialized = 0;
243 spin_lock_init(&sbsp->smk_sblock);
244
245 sb->s_security = sbsp;
246
247 return 0;
248 }
249
250 /**
251 * smack_sb_free_security - free a superblock blob
252 * @sb: the superblock getting the blob
253 *
254 */
255 static void smack_sb_free_security(struct super_block *sb)
256 {
257 kfree(sb->s_security);
258 sb->s_security = NULL;
259 }
260
261 /**
262 * smack_sb_copy_data - copy mount options data for processing
263 * @orig: where to start
264 * @smackopts: mount options string
265 *
266 * Returns 0 on success or -ENOMEM on error.
267 *
268 * Copy the Smack specific mount options out of the mount
269 * options list.
270 */
271 static int smack_sb_copy_data(char *orig, char *smackopts)
272 {
273 char *cp, *commap, *otheropts, *dp;
274
275 otheropts = (char *)get_zeroed_page(GFP_KERNEL);
276 if (otheropts == NULL)
277 return -ENOMEM;
278
279 for (cp = orig, commap = orig; commap != NULL; cp = commap + 1) {
280 if (strstr(cp, SMK_FSDEFAULT) == cp)
281 dp = smackopts;
282 else if (strstr(cp, SMK_FSFLOOR) == cp)
283 dp = smackopts;
284 else if (strstr(cp, SMK_FSHAT) == cp)
285 dp = smackopts;
286 else if (strstr(cp, SMK_FSROOT) == cp)
287 dp = smackopts;
288 else
289 dp = otheropts;
290
291 commap = strchr(cp, ',');
292 if (commap != NULL)
293 *commap = '\0';
294
295 if (*dp != '\0')
296 strcat(dp, ",");
297 strcat(dp, cp);
298 }
299
300 strcpy(orig, otheropts);
301 free_page((unsigned long)otheropts);
302
303 return 0;
304 }
305
306 /**
307 * smack_sb_kern_mount - Smack specific mount processing
308 * @sb: the file system superblock
309 * @flags: the mount flags
310 * @data: the smack mount options
311 *
312 * Returns 0 on success, an error code on failure
313 */
314 static int smack_sb_kern_mount(struct super_block *sb, int flags, void *data)
315 {
316 struct dentry *root = sb->s_root;
317 struct inode *inode = root->d_inode;
318 struct superblock_smack *sp = sb->s_security;
319 struct inode_smack *isp;
320 char *op;
321 char *commap;
322 char *nsp;
323
324 spin_lock(&sp->smk_sblock);
325 if (sp->smk_initialized != 0) {
326 spin_unlock(&sp->smk_sblock);
327 return 0;
328 }
329 sp->smk_initialized = 1;
330 spin_unlock(&sp->smk_sblock);
331
332 for (op = data; op != NULL; op = commap) {
333 commap = strchr(op, ',');
334 if (commap != NULL)
335 *commap++ = '\0';
336
337 if (strncmp(op, SMK_FSHAT, strlen(SMK_FSHAT)) == 0) {
338 op += strlen(SMK_FSHAT);
339 nsp = smk_import(op, 0);
340 if (nsp != NULL)
341 sp->smk_hat = nsp;
342 } else if (strncmp(op, SMK_FSFLOOR, strlen(SMK_FSFLOOR)) == 0) {
343 op += strlen(SMK_FSFLOOR);
344 nsp = smk_import(op, 0);
345 if (nsp != NULL)
346 sp->smk_floor = nsp;
347 } else if (strncmp(op, SMK_FSDEFAULT,
348 strlen(SMK_FSDEFAULT)) == 0) {
349 op += strlen(SMK_FSDEFAULT);
350 nsp = smk_import(op, 0);
351 if (nsp != NULL)
352 sp->smk_default = nsp;
353 } else if (strncmp(op, SMK_FSROOT, strlen(SMK_FSROOT)) == 0) {
354 op += strlen(SMK_FSROOT);
355 nsp = smk_import(op, 0);
356 if (nsp != NULL)
357 sp->smk_root = nsp;
358 }
359 }
360
361 /*
362 * Initialize the root inode.
363 */
364 isp = inode->i_security;
365 if (isp == NULL)
366 inode->i_security = new_inode_smack(sp->smk_root);
367 else
368 isp->smk_inode = sp->smk_root;
369
370 return 0;
371 }
372
373 /**
374 * smack_sb_statfs - Smack check on statfs
375 * @dentry: identifies the file system in question
376 *
377 * Returns 0 if current can read the floor of the filesystem,
378 * and error code otherwise
379 */
380 static int smack_sb_statfs(struct dentry *dentry)
381 {
382 struct superblock_smack *sbp = dentry->d_sb->s_security;
383 int rc;
384 struct smk_audit_info ad;
385
386 smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_FS);
387 smk_ad_setfield_u_fs_path_dentry(&ad, dentry);
388
389 rc = smk_curacc(sbp->smk_floor, MAY_READ, &ad);
390 return rc;
391 }
392
393 /**
394 * smack_sb_mount - Smack check for mounting
395 * @dev_name: unused
396 * @path: mount point
397 * @type: unused
398 * @flags: unused
399 * @data: unused
400 *
401 * Returns 0 if current can write the floor of the filesystem
402 * being mounted on, an error code otherwise.
403 */
404 static int smack_sb_mount(char *dev_name, struct path *path,
405 char *type, unsigned long flags, void *data)
406 {
407 struct superblock_smack *sbp = path->mnt->mnt_sb->s_security;
408 struct smk_audit_info ad;
409
410 smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_FS);
411 smk_ad_setfield_u_fs_path(&ad, *path);
412
413 return smk_curacc(sbp->smk_floor, MAY_WRITE, &ad);
414 }
415
416 /**
417 * smack_sb_umount - Smack check for unmounting
418 * @mnt: file system to unmount
419 * @flags: unused
420 *
421 * Returns 0 if current can write the floor of the filesystem
422 * being unmounted, an error code otherwise.
423 */
424 static int smack_sb_umount(struct vfsmount *mnt, int flags)
425 {
426 struct superblock_smack *sbp;
427 struct smk_audit_info ad;
428
429 smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_FS);
430 smk_ad_setfield_u_fs_path_dentry(&ad, mnt->mnt_root);
431 smk_ad_setfield_u_fs_path_mnt(&ad, mnt);
432
433 sbp = mnt->mnt_sb->s_security;
434 return smk_curacc(sbp->smk_floor, MAY_WRITE, &ad);
435 }
436
437 /*
438 * BPRM hooks
439 */
440
441 static int smack_bprm_set_creds(struct linux_binprm *bprm)
442 {
443 struct task_smack *tsp = bprm->cred->security;
444 struct inode_smack *isp;
445 struct dentry *dp;
446 int rc;
447
448 rc = cap_bprm_set_creds(bprm);
449 if (rc != 0)
450 return rc;
451
452 if (bprm->cred_prepared)
453 return 0;
454
455 if (bprm->file == NULL || bprm->file->f_dentry == NULL)
456 return 0;
457
458 dp = bprm->file->f_dentry;
459
460 if (dp->d_inode == NULL)
461 return 0;
462
463 isp = dp->d_inode->i_security;
464
465 if (isp->smk_task != NULL)
466 tsp->smk_task = isp->smk_task;
467
468 return 0;
469 }
470
471 /*
472 * Inode hooks
473 */
474
475 /**
476 * smack_inode_alloc_security - allocate an inode blob
477 * @inode: the inode in need of a blob
478 *
479 * Returns 0 if it gets a blob, -ENOMEM otherwise
480 */
481 static int smack_inode_alloc_security(struct inode *inode)
482 {
483 inode->i_security = new_inode_smack(smk_of_current());
484 if (inode->i_security == NULL)
485 return -ENOMEM;
486 return 0;
487 }
488
489 /**
490 * smack_inode_free_security - free an inode blob
491 * @inode: the inode with a blob
492 *
493 * Clears the blob pointer in inode
494 */
495 static void smack_inode_free_security(struct inode *inode)
496 {
497 kfree(inode->i_security);
498 inode->i_security = NULL;
499 }
500
501 /**
502 * smack_inode_init_security - copy out the smack from an inode
503 * @inode: the inode
504 * @dir: unused
505 * @qstr: unused
506 * @name: where to put the attribute name
507 * @value: where to put the attribute value
508 * @len: where to put the length of the attribute
509 *
510 * Returns 0 if it all works out, -ENOMEM if there's no memory
511 */
512 static int smack_inode_init_security(struct inode *inode, struct inode *dir,
513 const struct qstr *qstr, char **name,
514 void **value, size_t *len)
515 {
516 char *isp = smk_of_inode(inode);
517 char *dsp = smk_of_inode(dir);
518 int may;
519
520 if (name) {
521 *name = kstrdup(XATTR_SMACK_SUFFIX, GFP_KERNEL);
522 if (*name == NULL)
523 return -ENOMEM;
524 }
525
526 if (value) {
527 rcu_read_lock();
528 may = smk_access_entry(smk_of_current(), dsp, &smack_rule_list);
529 rcu_read_unlock();
530
531 /*
532 * If the access rule allows transmutation and
533 * the directory requests transmutation then
534 * by all means transmute.
535 */
536 if (may > 0 && ((may & MAY_TRANSMUTE) != 0) &&
537 smk_inode_transmutable(dir))
538 isp = dsp;
539
540 *value = kstrdup(isp, GFP_KERNEL);
541 if (*value == NULL)
542 return -ENOMEM;
543 }
544
545 if (len)
546 *len = strlen(isp) + 1;
547
548 return 0;
549 }
550
551 /**
552 * smack_inode_link - Smack check on link
553 * @old_dentry: the existing object
554 * @dir: unused
555 * @new_dentry: the new object
556 *
557 * Returns 0 if access is permitted, an error code otherwise
558 */
559 static int smack_inode_link(struct dentry *old_dentry, struct inode *dir,
560 struct dentry *new_dentry)
561 {
562 char *isp;
563 struct smk_audit_info ad;
564 int rc;
565
566 smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_FS);
567 smk_ad_setfield_u_fs_path_dentry(&ad, old_dentry);
568
569 isp = smk_of_inode(old_dentry->d_inode);
570 rc = smk_curacc(isp, MAY_WRITE, &ad);
571
572 if (rc == 0 && new_dentry->d_inode != NULL) {
573 isp = smk_of_inode(new_dentry->d_inode);
574 smk_ad_setfield_u_fs_path_dentry(&ad, new_dentry);
575 rc = smk_curacc(isp, MAY_WRITE, &ad);
576 }
577
578 return rc;
579 }
580
581 /**
582 * smack_inode_unlink - Smack check on inode deletion
583 * @dir: containing directory object
584 * @dentry: file to unlink
585 *
586 * Returns 0 if current can write the containing directory
587 * and the object, error code otherwise
588 */
589 static int smack_inode_unlink(struct inode *dir, struct dentry *dentry)
590 {
591 struct inode *ip = dentry->d_inode;
592 struct smk_audit_info ad;
593 int rc;
594
595 smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_FS);
596 smk_ad_setfield_u_fs_path_dentry(&ad, dentry);
597
598 /*
599 * You need write access to the thing you're unlinking
600 */
601 rc = smk_curacc(smk_of_inode(ip), MAY_WRITE, &ad);
602 if (rc == 0) {
603 /*
604 * You also need write access to the containing directory
605 */
606 smk_ad_setfield_u_fs_path_dentry(&ad, NULL);
607 smk_ad_setfield_u_fs_inode(&ad, dir);
608 rc = smk_curacc(smk_of_inode(dir), MAY_WRITE, &ad);
609 }
610 return rc;
611 }
612
613 /**
614 * smack_inode_rmdir - Smack check on directory deletion
615 * @dir: containing directory object
616 * @dentry: directory to unlink
617 *
618 * Returns 0 if current can write the containing directory
619 * and the directory, error code otherwise
620 */
621 static int smack_inode_rmdir(struct inode *dir, struct dentry *dentry)
622 {
623 struct smk_audit_info ad;
624 int rc;
625
626 smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_FS);
627 smk_ad_setfield_u_fs_path_dentry(&ad, dentry);
628
629 /*
630 * You need write access to the thing you're removing
631 */
632 rc = smk_curacc(smk_of_inode(dentry->d_inode), MAY_WRITE, &ad);
633 if (rc == 0) {
634 /*
635 * You also need write access to the containing directory
636 */
637 smk_ad_setfield_u_fs_path_dentry(&ad, NULL);
638 smk_ad_setfield_u_fs_inode(&ad, dir);
639 rc = smk_curacc(smk_of_inode(dir), MAY_WRITE, &ad);
640 }
641
642 return rc;
643 }
644
645 /**
646 * smack_inode_rename - Smack check on rename
647 * @old_inode: the old directory
648 * @old_dentry: unused
649 * @new_inode: the new directory
650 * @new_dentry: unused
651 *
652 * Read and write access is required on both the old and
653 * new directories.
654 *
655 * Returns 0 if access is permitted, an error code otherwise
656 */
657 static int smack_inode_rename(struct inode *old_inode,
658 struct dentry *old_dentry,
659 struct inode *new_inode,
660 struct dentry *new_dentry)
661 {
662 int rc;
663 char *isp;
664 struct smk_audit_info ad;
665
666 smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_FS);
667 smk_ad_setfield_u_fs_path_dentry(&ad, old_dentry);
668
669 isp = smk_of_inode(old_dentry->d_inode);
670 rc = smk_curacc(isp, MAY_READWRITE, &ad);
671
672 if (rc == 0 && new_dentry->d_inode != NULL) {
673 isp = smk_of_inode(new_dentry->d_inode);
674 smk_ad_setfield_u_fs_path_dentry(&ad, new_dentry);
675 rc = smk_curacc(isp, MAY_READWRITE, &ad);
676 }
677 return rc;
678 }
679
680 /**
681 * smack_inode_permission - Smack version of permission()
682 * @inode: the inode in question
683 * @mask: the access requested
684 *
685 * This is the important Smack hook.
686 *
687 * Returns 0 if access is permitted, -EACCES otherwise
688 */
689 static int smack_inode_permission(struct inode *inode, int mask)
690 {
691 struct smk_audit_info ad;
692
693 mask &= (MAY_READ|MAY_WRITE|MAY_EXEC|MAY_APPEND);
694 /*
695 * No permission to check. Existence test. Yup, it's there.
696 */
697 if (mask == 0)
698 return 0;
699 smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_FS);
700 smk_ad_setfield_u_fs_inode(&ad, inode);
701 return smk_curacc(smk_of_inode(inode), mask, &ad);
702 }
703
704 /**
705 * smack_inode_setattr - Smack check for setting attributes
706 * @dentry: the object
707 * @iattr: for the force flag
708 *
709 * Returns 0 if access is permitted, an error code otherwise
710 */
711 static int smack_inode_setattr(struct dentry *dentry, struct iattr *iattr)
712 {
713 struct smk_audit_info ad;
714 /*
715 * Need to allow for clearing the setuid bit.
716 */
717 if (iattr->ia_valid & ATTR_FORCE)
718 return 0;
719 smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_FS);
720 smk_ad_setfield_u_fs_path_dentry(&ad, dentry);
721
722 return smk_curacc(smk_of_inode(dentry->d_inode), MAY_WRITE, &ad);
723 }
724
725 /**
726 * smack_inode_getattr - Smack check for getting attributes
727 * @mnt: unused
728 * @dentry: the object
729 *
730 * Returns 0 if access is permitted, an error code otherwise
731 */
732 static int smack_inode_getattr(struct vfsmount *mnt, struct dentry *dentry)
733 {
734 struct smk_audit_info ad;
735
736 smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_FS);
737 smk_ad_setfield_u_fs_path_dentry(&ad, dentry);
738 smk_ad_setfield_u_fs_path_mnt(&ad, mnt);
739 return smk_curacc(smk_of_inode(dentry->d_inode), MAY_READ, &ad);
740 }
741
742 /**
743 * smack_inode_setxattr - Smack check for setting xattrs
744 * @dentry: the object
745 * @name: name of the attribute
746 * @value: unused
747 * @size: unused
748 * @flags: unused
749 *
750 * This protects the Smack attribute explicitly.
751 *
752 * Returns 0 if access is permitted, an error code otherwise
753 */
754 static int smack_inode_setxattr(struct dentry *dentry, const char *name,
755 const void *value, size_t size, int flags)
756 {
757 struct smk_audit_info ad;
758 int rc = 0;
759
760 if (strcmp(name, XATTR_NAME_SMACK) == 0 ||
761 strcmp(name, XATTR_NAME_SMACKIPIN) == 0 ||
762 strcmp(name, XATTR_NAME_SMACKIPOUT) == 0 ||
763 strcmp(name, XATTR_NAME_SMACKEXEC) == 0 ||
764 strcmp(name, XATTR_NAME_SMACKMMAP) == 0) {
765 if (!capable(CAP_MAC_ADMIN))
766 rc = -EPERM;
767 /*
768 * check label validity here so import wont fail on
769 * post_setxattr
770 */
771 if (size == 0 || size >= SMK_LABELLEN ||
772 smk_import(value, size) == NULL)
773 rc = -EINVAL;
774 } else if (strcmp(name, XATTR_NAME_SMACKTRANSMUTE) == 0) {
775 if (!capable(CAP_MAC_ADMIN))
776 rc = -EPERM;
777 if (size != TRANS_TRUE_SIZE ||
778 strncmp(value, TRANS_TRUE, TRANS_TRUE_SIZE) != 0)
779 rc = -EINVAL;
780 } else
781 rc = cap_inode_setxattr(dentry, name, value, size, flags);
782
783 smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_FS);
784 smk_ad_setfield_u_fs_path_dentry(&ad, dentry);
785
786 if (rc == 0)
787 rc = smk_curacc(smk_of_inode(dentry->d_inode), MAY_WRITE, &ad);
788
789 return rc;
790 }
791
792 /**
793 * smack_inode_post_setxattr - Apply the Smack update approved above
794 * @dentry: object
795 * @name: attribute name
796 * @value: attribute value
797 * @size: attribute size
798 * @flags: unused
799 *
800 * Set the pointer in the inode blob to the entry found
801 * in the master label list.
802 */
803 static void smack_inode_post_setxattr(struct dentry *dentry, const char *name,
804 const void *value, size_t size, int flags)
805 {
806 char *nsp;
807 struct inode_smack *isp = dentry->d_inode->i_security;
808
809 if (strcmp(name, XATTR_NAME_SMACK) == 0) {
810 nsp = smk_import(value, size);
811 if (nsp != NULL)
812 isp->smk_inode = nsp;
813 else
814 isp->smk_inode = smack_known_invalid.smk_known;
815 } else if (strcmp(name, XATTR_NAME_SMACKEXEC) == 0) {
816 nsp = smk_import(value, size);
817 if (nsp != NULL)
818 isp->smk_task = nsp;
819 else
820 isp->smk_task = smack_known_invalid.smk_known;
821 } else if (strcmp(name, XATTR_NAME_SMACKMMAP) == 0) {
822 nsp = smk_import(value, size);
823 if (nsp != NULL)
824 isp->smk_mmap = nsp;
825 else
826 isp->smk_mmap = smack_known_invalid.smk_known;
827 } else if (strcmp(name, XATTR_NAME_SMACKTRANSMUTE) == 0)
828 isp->smk_flags |= SMK_INODE_TRANSMUTE;
829
830 return;
831 }
832
833 /*
834 * smack_inode_getxattr - Smack check on getxattr
835 * @dentry: the object
836 * @name: unused
837 *
838 * Returns 0 if access is permitted, an error code otherwise
839 */
840 static int smack_inode_getxattr(struct dentry *dentry, const char *name)
841 {
842 struct smk_audit_info ad;
843
844 smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_FS);
845 smk_ad_setfield_u_fs_path_dentry(&ad, dentry);
846
847 return smk_curacc(smk_of_inode(dentry->d_inode), MAY_READ, &ad);
848 }
849
850 /*
851 * smack_inode_removexattr - Smack check on removexattr
852 * @dentry: the object
853 * @name: name of the attribute
854 *
855 * Removing the Smack attribute requires CAP_MAC_ADMIN
856 *
857 * Returns 0 if access is permitted, an error code otherwise
858 */
859 static int smack_inode_removexattr(struct dentry *dentry, const char *name)
860 {
861 struct inode_smack *isp;
862 struct smk_audit_info ad;
863 int rc = 0;
864
865 if (strcmp(name, XATTR_NAME_SMACK) == 0 ||
866 strcmp(name, XATTR_NAME_SMACKIPIN) == 0 ||
867 strcmp(name, XATTR_NAME_SMACKIPOUT) == 0 ||
868 strcmp(name, XATTR_NAME_SMACKEXEC) == 0 ||
869 strcmp(name, XATTR_NAME_SMACKTRANSMUTE) == 0 ||
870 strcmp(name, XATTR_NAME_SMACKMMAP)) {
871 if (!capable(CAP_MAC_ADMIN))
872 rc = -EPERM;
873 } else
874 rc = cap_inode_removexattr(dentry, name);
875
876 smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_FS);
877 smk_ad_setfield_u_fs_path_dentry(&ad, dentry);
878 if (rc == 0)
879 rc = smk_curacc(smk_of_inode(dentry->d_inode), MAY_WRITE, &ad);
880
881 if (rc == 0) {
882 isp = dentry->d_inode->i_security;
883 isp->smk_task = NULL;
884 isp->smk_mmap = NULL;
885 }
886
887 return rc;
888 }
889
890 /**
891 * smack_inode_getsecurity - get smack xattrs
892 * @inode: the object
893 * @name: attribute name
894 * @buffer: where to put the result
895 * @alloc: unused
896 *
897 * Returns the size of the attribute or an error code
898 */
899 static int smack_inode_getsecurity(const struct inode *inode,
900 const char *name, void **buffer,
901 bool alloc)
902 {
903 struct socket_smack *ssp;
904 struct socket *sock;
905 struct super_block *sbp;
906 struct inode *ip = (struct inode *)inode;
907 char *isp;
908 int ilen;
909 int rc = 0;
910
911 if (strcmp(name, XATTR_SMACK_SUFFIX) == 0) {
912 isp = smk_of_inode(inode);
913 ilen = strlen(isp) + 1;
914 *buffer = isp;
915 return ilen;
916 }
917
918 /*
919 * The rest of the Smack xattrs are only on sockets.
920 */
921 sbp = ip->i_sb;
922 if (sbp->s_magic != SOCKFS_MAGIC)
923 return -EOPNOTSUPP;
924
925 sock = SOCKET_I(ip);
926 if (sock == NULL || sock->sk == NULL)
927 return -EOPNOTSUPP;
928
929 ssp = sock->sk->sk_security;
930
931 if (strcmp(name, XATTR_SMACK_IPIN) == 0)
932 isp = ssp->smk_in;
933 else if (strcmp(name, XATTR_SMACK_IPOUT) == 0)
934 isp = ssp->smk_out;
935 else
936 return -EOPNOTSUPP;
937
938 ilen = strlen(isp) + 1;
939 if (rc == 0) {
940 *buffer = isp;
941 rc = ilen;
942 }
943
944 return rc;
945 }
946
947
948 /**
949 * smack_inode_listsecurity - list the Smack attributes
950 * @inode: the object
951 * @buffer: where they go
952 * @buffer_size: size of buffer
953 *
954 * Returns 0 on success, -EINVAL otherwise
955 */
956 static int smack_inode_listsecurity(struct inode *inode, char *buffer,
957 size_t buffer_size)
958 {
959 int len = strlen(XATTR_NAME_SMACK);
960
961 if (buffer != NULL && len <= buffer_size) {
962 memcpy(buffer, XATTR_NAME_SMACK, len);
963 return len;
964 }
965 return -EINVAL;
966 }
967
968 /**
969 * smack_inode_getsecid - Extract inode's security id
970 * @inode: inode to extract the info from
971 * @secid: where result will be saved
972 */
973 static void smack_inode_getsecid(const struct inode *inode, u32 *secid)
974 {
975 struct inode_smack *isp = inode->i_security;
976
977 *secid = smack_to_secid(isp->smk_inode);
978 }
979
980 /*
981 * File Hooks
982 */
983
984 /**
985 * smack_file_permission - Smack check on file operations
986 * @file: unused
987 * @mask: unused
988 *
989 * Returns 0
990 *
991 * Should access checks be done on each read or write?
992 * UNICOS and SELinux say yes.
993 * Trusted Solaris, Trusted Irix, and just about everyone else says no.
994 *
995 * I'll say no for now. Smack does not do the frequent
996 * label changing that SELinux does.
997 */
998 static int smack_file_permission(struct file *file, int mask)
999 {
1000 return 0;
1001 }
1002
1003 /**
1004 * smack_file_alloc_security - assign a file security blob
1005 * @file: the object
1006 *
1007 * The security blob for a file is a pointer to the master
1008 * label list, so no allocation is done.
1009 *
1010 * Returns 0
1011 */
1012 static int smack_file_alloc_security(struct file *file)
1013 {
1014 file->f_security = smk_of_current();
1015 return 0;
1016 }
1017
1018 /**
1019 * smack_file_free_security - clear a file security blob
1020 * @file: the object
1021 *
1022 * The security blob for a file is a pointer to the master
1023 * label list, so no memory is freed.
1024 */
1025 static void smack_file_free_security(struct file *file)
1026 {
1027 file->f_security = NULL;
1028 }
1029
1030 /**
1031 * smack_file_ioctl - Smack check on ioctls
1032 * @file: the object
1033 * @cmd: what to do
1034 * @arg: unused
1035 *
1036 * Relies heavily on the correct use of the ioctl command conventions.
1037 *
1038 * Returns 0 if allowed, error code otherwise
1039 */
1040 static int smack_file_ioctl(struct file *file, unsigned int cmd,
1041 unsigned long arg)
1042 {
1043 int rc = 0;
1044 struct smk_audit_info ad;
1045
1046 smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_FS);
1047 smk_ad_setfield_u_fs_path(&ad, file->f_path);
1048
1049 if (_IOC_DIR(cmd) & _IOC_WRITE)
1050 rc = smk_curacc(file->f_security, MAY_WRITE, &ad);
1051
1052 if (rc == 0 && (_IOC_DIR(cmd) & _IOC_READ))
1053 rc = smk_curacc(file->f_security, MAY_READ, &ad);
1054
1055 return rc;
1056 }
1057
1058 /**
1059 * smack_file_lock - Smack check on file locking
1060 * @file: the object
1061 * @cmd: unused
1062 *
1063 * Returns 0 if current has write access, error code otherwise
1064 */
1065 static int smack_file_lock(struct file *file, unsigned int cmd)
1066 {
1067 struct smk_audit_info ad;
1068
1069 smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_FS);
1070 smk_ad_setfield_u_fs_path_dentry(&ad, file->f_path.dentry);
1071 return smk_curacc(file->f_security, MAY_WRITE, &ad);
1072 }
1073
1074 /**
1075 * smack_file_fcntl - Smack check on fcntl
1076 * @file: the object
1077 * @cmd: what action to check
1078 * @arg: unused
1079 *
1080 * Returns 0 if current has access, error code otherwise
1081 */
1082 static int smack_file_fcntl(struct file *file, unsigned int cmd,
1083 unsigned long arg)
1084 {
1085 struct smk_audit_info ad;
1086 int rc;
1087
1088 smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_FS);
1089 smk_ad_setfield_u_fs_path(&ad, file->f_path);
1090
1091 switch (cmd) {
1092 case F_DUPFD:
1093 case F_GETFD:
1094 case F_GETFL:
1095 case F_GETLK:
1096 case F_GETOWN:
1097 case F_GETSIG:
1098 rc = smk_curacc(file->f_security, MAY_READ, &ad);
1099 break;
1100 case F_SETFD:
1101 case F_SETFL:
1102 case F_SETLK:
1103 case F_SETLKW:
1104 case F_SETOWN:
1105 case F_SETSIG:
1106 rc = smk_curacc(file->f_security, MAY_WRITE, &ad);
1107 break;
1108 default:
1109 rc = smk_curacc(file->f_security, MAY_READWRITE, &ad);
1110 }
1111
1112 return rc;
1113 }
1114
1115 /**
1116 * smk_mmap_list_check - the mmap check
1117 * @sub: subject label
1118 * @obj: object label
1119 * @access: access mode
1120 * @local: the task specific rule list
1121 *
1122 * Returns 0 if acces is permitted, -EACCES otherwise
1123 */
1124 static int smk_mmap_list_check(char *sub, char *obj, int access,
1125 struct list_head *local)
1126 {
1127 int may;
1128
1129 /*
1130 * If there is not a global rule that
1131 * allows access say no.
1132 */
1133 may = smk_access_entry(sub, obj, &smack_rule_list);
1134 if (may == -ENOENT || (may & access) != access)
1135 return -EACCES;
1136 /*
1137 * If there is a task local rule that
1138 * denies access say no.
1139 */
1140 may = smk_access_entry(sub, obj, local);
1141 if (may != -ENOENT && (may & access) != access)
1142 return -EACCES;
1143
1144 return 0;
1145 }
1146
1147 /**
1148 * smack_file_mmap :
1149 * Check permissions for a mmap operation. The @file may be NULL, e.g.
1150 * if mapping anonymous memory.
1151 * @file contains the file structure for file to map (may be NULL).
1152 * @reqprot contains the protection requested by the application.
1153 * @prot contains the protection that will be applied by the kernel.
1154 * @flags contains the operational flags.
1155 * Return 0 if permission is granted.
1156 */
1157 static int smack_file_mmap(struct file *file,
1158 unsigned long reqprot, unsigned long prot,
1159 unsigned long flags, unsigned long addr,
1160 unsigned long addr_only)
1161 {
1162 struct smack_rule *srp;
1163 struct task_smack *tsp;
1164 char *sp;
1165 char *msmack;
1166 struct inode_smack *isp;
1167 struct dentry *dp;
1168 int rc;
1169
1170 /* do DAC check on address space usage */
1171 rc = cap_file_mmap(file, reqprot, prot, flags, addr, addr_only);
1172 if (rc || addr_only)
1173 return rc;
1174
1175 if (file == NULL || file->f_dentry == NULL)
1176 return 0;
1177
1178 dp = file->f_dentry;
1179
1180 if (dp->d_inode == NULL)
1181 return 0;
1182
1183 isp = dp->d_inode->i_security;
1184 if (isp->smk_mmap == NULL)
1185 return 0;
1186 msmack = isp->smk_mmap;
1187
1188 tsp = current_security();
1189 sp = smk_of_current();
1190 rc = 0;
1191
1192 rcu_read_lock();
1193 /*
1194 * For each Smack rule associated with the subject
1195 * label verify that the SMACK64MMAP also has access
1196 * to that rule's object label.
1197 *
1198 * Because neither of the labels comes
1199 * from the networking code it is sufficient
1200 * to compare pointers.
1201 */
1202 list_for_each_entry_rcu(srp, &smack_rule_list, list) {
1203 if (srp->smk_subject != sp)
1204 continue;
1205 /*
1206 * Matching labels always allows access.
1207 */
1208 if (msmack == srp->smk_object)
1209 continue;
1210
1211 rc = smk_mmap_list_check(msmack, srp->smk_object,
1212 srp->smk_access, &tsp->smk_rules);
1213 if (rc != 0)
1214 break;
1215 }
1216
1217 rcu_read_unlock();
1218
1219 return rc;
1220 }
1221
1222 /**
1223 * smack_file_set_fowner - set the file security blob value
1224 * @file: object in question
1225 *
1226 * Returns 0
1227 * Further research may be required on this one.
1228 */
1229 static int smack_file_set_fowner(struct file *file)
1230 {
1231 file->f_security = smk_of_current();
1232 return 0;
1233 }
1234
1235 /**
1236 * smack_file_send_sigiotask - Smack on sigio
1237 * @tsk: The target task
1238 * @fown: the object the signal come from
1239 * @signum: unused
1240 *
1241 * Allow a privileged task to get signals even if it shouldn't
1242 *
1243 * Returns 0 if a subject with the object's smack could
1244 * write to the task, an error code otherwise.
1245 */
1246 static int smack_file_send_sigiotask(struct task_struct *tsk,
1247 struct fown_struct *fown, int signum)
1248 {
1249 struct file *file;
1250 int rc;
1251 char *tsp = smk_of_task(tsk->cred->security);
1252 struct smk_audit_info ad;
1253
1254 /*
1255 * struct fown_struct is never outside the context of a struct file
1256 */
1257 file = container_of(fown, struct file, f_owner);
1258
1259 /* we don't log here as rc can be overriden */
1260 rc = smk_access(file->f_security, tsp, MAY_WRITE, NULL);
1261 if (rc != 0 && has_capability(tsk, CAP_MAC_OVERRIDE))
1262 rc = 0;
1263
1264 smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_TASK);
1265 smk_ad_setfield_u_tsk(&ad, tsk);
1266 smack_log(file->f_security, tsp, MAY_WRITE, rc, &ad);
1267 return rc;
1268 }
1269
1270 /**
1271 * smack_file_receive - Smack file receive check
1272 * @file: the object
1273 *
1274 * Returns 0 if current has access, error code otherwise
1275 */
1276 static int smack_file_receive(struct file *file)
1277 {
1278 int may = 0;
1279 struct smk_audit_info ad;
1280
1281 smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_TASK);
1282 smk_ad_setfield_u_fs_path(&ad, file->f_path);
1283 /*
1284 * This code relies on bitmasks.
1285 */
1286 if (file->f_mode & FMODE_READ)
1287 may = MAY_READ;
1288 if (file->f_mode & FMODE_WRITE)
1289 may |= MAY_WRITE;
1290
1291 return smk_curacc(file->f_security, may, &ad);
1292 }
1293
1294 /*
1295 * Task hooks
1296 */
1297
1298 /**
1299 * smack_cred_alloc_blank - "allocate" blank task-level security credentials
1300 * @new: the new credentials
1301 * @gfp: the atomicity of any memory allocations
1302 *
1303 * Prepare a blank set of credentials for modification. This must allocate all
1304 * the memory the LSM module might require such that cred_transfer() can
1305 * complete without error.
1306 */
1307 static int smack_cred_alloc_blank(struct cred *cred, gfp_t gfp)
1308 {
1309 struct task_smack *tsp;
1310
1311 tsp = new_task_smack(NULL, NULL, gfp);
1312 if (tsp == NULL)
1313 return -ENOMEM;
1314
1315 cred->security = tsp;
1316
1317 return 0;
1318 }
1319
1320
1321 /**
1322 * smack_cred_free - "free" task-level security credentials
1323 * @cred: the credentials in question
1324 *
1325 */
1326 static void smack_cred_free(struct cred *cred)
1327 {
1328 struct task_smack *tsp = cred->security;
1329 struct smack_rule *rp;
1330 struct list_head *l;
1331 struct list_head *n;
1332
1333 if (tsp == NULL)
1334 return;
1335 cred->security = NULL;
1336
1337 list_for_each_safe(l, n, &tsp->smk_rules) {
1338 rp = list_entry(l, struct smack_rule, list);
1339 list_del(&rp->list);
1340 kfree(rp);
1341 }
1342 kfree(tsp);
1343 }
1344
1345 /**
1346 * smack_cred_prepare - prepare new set of credentials for modification
1347 * @new: the new credentials
1348 * @old: the original credentials
1349 * @gfp: the atomicity of any memory allocations
1350 *
1351 * Prepare a new set of credentials for modification.
1352 */
1353 static int smack_cred_prepare(struct cred *new, const struct cred *old,
1354 gfp_t gfp)
1355 {
1356 struct task_smack *old_tsp = old->security;
1357 struct task_smack *new_tsp;
1358 int rc;
1359
1360 new_tsp = new_task_smack(old_tsp->smk_task, old_tsp->smk_task, gfp);
1361 if (new_tsp == NULL)
1362 return -ENOMEM;
1363
1364 rc = smk_copy_rules(&new_tsp->smk_rules, &old_tsp->smk_rules, gfp);
1365 if (rc != 0)
1366 return rc;
1367
1368 new->security = new_tsp;
1369 return 0;
1370 }
1371
1372 /**
1373 * smack_cred_transfer - Transfer the old credentials to the new credentials
1374 * @new: the new credentials
1375 * @old: the original credentials
1376 *
1377 * Fill in a set of blank credentials from another set of credentials.
1378 */
1379 static void smack_cred_transfer(struct cred *new, const struct cred *old)
1380 {
1381 struct task_smack *old_tsp = old->security;
1382 struct task_smack *new_tsp = new->security;
1383
1384 new_tsp->smk_task = old_tsp->smk_task;
1385 new_tsp->smk_forked = old_tsp->smk_task;
1386 mutex_init(&new_tsp->smk_rules_lock);
1387 INIT_LIST_HEAD(&new_tsp->smk_rules);
1388
1389
1390 /* cbs copy rule list */
1391 }
1392
1393 /**
1394 * smack_kernel_act_as - Set the subjective context in a set of credentials
1395 * @new: points to the set of credentials to be modified.
1396 * @secid: specifies the security ID to be set
1397 *
1398 * Set the security data for a kernel service.
1399 */
1400 static int smack_kernel_act_as(struct cred *new, u32 secid)
1401 {
1402 struct task_smack *new_tsp = new->security;
1403 char *smack = smack_from_secid(secid);
1404
1405 if (smack == NULL)
1406 return -EINVAL;
1407
1408 new_tsp->smk_task = smack;
1409 return 0;
1410 }
1411
1412 /**
1413 * smack_kernel_create_files_as - Set the file creation label in a set of creds
1414 * @new: points to the set of credentials to be modified
1415 * @inode: points to the inode to use as a reference
1416 *
1417 * Set the file creation context in a set of credentials to the same
1418 * as the objective context of the specified inode
1419 */
1420 static int smack_kernel_create_files_as(struct cred *new,
1421 struct inode *inode)
1422 {
1423 struct inode_smack *isp = inode->i_security;
1424 struct task_smack *tsp = new->security;
1425
1426 tsp->smk_forked = isp->smk_inode;
1427 tsp->smk_task = isp->smk_inode;
1428 return 0;
1429 }
1430
1431 /**
1432 * smk_curacc_on_task - helper to log task related access
1433 * @p: the task object
1434 * @access : the access requested
1435 *
1436 * Return 0 if access is permitted
1437 */
1438 static int smk_curacc_on_task(struct task_struct *p, int access)
1439 {
1440 struct smk_audit_info ad;
1441
1442 smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_TASK);
1443 smk_ad_setfield_u_tsk(&ad, p);
1444 return smk_curacc(smk_of_task(task_security(p)), access, &ad);
1445 }
1446
1447 /**
1448 * smack_task_setpgid - Smack check on setting pgid
1449 * @p: the task object
1450 * @pgid: unused
1451 *
1452 * Return 0 if write access is permitted
1453 */
1454 static int smack_task_setpgid(struct task_struct *p, pid_t pgid)
1455 {
1456 return smk_curacc_on_task(p, MAY_WRITE);
1457 }
1458
1459 /**
1460 * smack_task_getpgid - Smack access check for getpgid
1461 * @p: the object task
1462 *
1463 * Returns 0 if current can read the object task, error code otherwise
1464 */
1465 static int smack_task_getpgid(struct task_struct *p)
1466 {
1467 return smk_curacc_on_task(p, MAY_READ);
1468 }
1469
1470 /**
1471 * smack_task_getsid - Smack access check for getsid
1472 * @p: the object task
1473 *
1474 * Returns 0 if current can read the object task, error code otherwise
1475 */
1476 static int smack_task_getsid(struct task_struct *p)
1477 {
1478 return smk_curacc_on_task(p, MAY_READ);
1479 }
1480
1481 /**
1482 * smack_task_getsecid - get the secid of the task
1483 * @p: the object task
1484 * @secid: where to put the result
1485 *
1486 * Sets the secid to contain a u32 version of the smack label.
1487 */
1488 static void smack_task_getsecid(struct task_struct *p, u32 *secid)
1489 {
1490 *secid = smack_to_secid(smk_of_task(task_security(p)));
1491 }
1492
1493 /**
1494 * smack_task_setnice - Smack check on setting nice
1495 * @p: the task object
1496 * @nice: unused
1497 *
1498 * Return 0 if write access is permitted
1499 */
1500 static int smack_task_setnice(struct task_struct *p, int nice)
1501 {
1502 int rc;
1503
1504 rc = cap_task_setnice(p, nice);
1505 if (rc == 0)
1506 rc = smk_curacc_on_task(p, MAY_WRITE);
1507 return rc;
1508 }
1509
1510 /**
1511 * smack_task_setioprio - Smack check on setting ioprio
1512 * @p: the task object
1513 * @ioprio: unused
1514 *
1515 * Return 0 if write access is permitted
1516 */
1517 static int smack_task_setioprio(struct task_struct *p, int ioprio)
1518 {
1519 int rc;
1520
1521 rc = cap_task_setioprio(p, ioprio);
1522 if (rc == 0)
1523 rc = smk_curacc_on_task(p, MAY_WRITE);
1524 return rc;
1525 }
1526
1527 /**
1528 * smack_task_getioprio - Smack check on reading ioprio
1529 * @p: the task object
1530 *
1531 * Return 0 if read access is permitted
1532 */
1533 static int smack_task_getioprio(struct task_struct *p)
1534 {
1535 return smk_curacc_on_task(p, MAY_READ);
1536 }
1537
1538 /**
1539 * smack_task_setscheduler - Smack check on setting scheduler
1540 * @p: the task object
1541 * @policy: unused
1542 * @lp: unused
1543 *
1544 * Return 0 if read access is permitted
1545 */
1546 static int smack_task_setscheduler(struct task_struct *p)
1547 {
1548 int rc;
1549
1550 rc = cap_task_setscheduler(p);
1551 if (rc == 0)
1552 rc = smk_curacc_on_task(p, MAY_WRITE);
1553 return rc;
1554 }
1555
1556 /**
1557 * smack_task_getscheduler - Smack check on reading scheduler
1558 * @p: the task object
1559 *
1560 * Return 0 if read access is permitted
1561 */
1562 static int smack_task_getscheduler(struct task_struct *p)
1563 {
1564 return smk_curacc_on_task(p, MAY_READ);
1565 }
1566
1567 /**
1568 * smack_task_movememory - Smack check on moving memory
1569 * @p: the task object
1570 *
1571 * Return 0 if write access is permitted
1572 */
1573 static int smack_task_movememory(struct task_struct *p)
1574 {
1575 return smk_curacc_on_task(p, MAY_WRITE);
1576 }
1577
1578 /**
1579 * smack_task_kill - Smack check on signal delivery
1580 * @p: the task object
1581 * @info: unused
1582 * @sig: unused
1583 * @secid: identifies the smack to use in lieu of current's
1584 *
1585 * Return 0 if write access is permitted
1586 *
1587 * The secid behavior is an artifact of an SELinux hack
1588 * in the USB code. Someday it may go away.
1589 */
1590 static int smack_task_kill(struct task_struct *p, struct siginfo *info,
1591 int sig, u32 secid)
1592 {
1593 struct smk_audit_info ad;
1594
1595 smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_TASK);
1596 smk_ad_setfield_u_tsk(&ad, p);
1597 /*
1598 * Sending a signal requires that the sender
1599 * can write the receiver.
1600 */
1601 if (secid == 0)
1602 return smk_curacc(smk_of_task(task_security(p)), MAY_WRITE,
1603 &ad);
1604 /*
1605 * If the secid isn't 0 we're dealing with some USB IO
1606 * specific behavior. This is not clean. For one thing
1607 * we can't take privilege into account.
1608 */
1609 return smk_access(smack_from_secid(secid),
1610 smk_of_task(task_security(p)), MAY_WRITE, &ad);
1611 }
1612
1613 /**
1614 * smack_task_wait - Smack access check for waiting
1615 * @p: task to wait for
1616 *
1617 * Returns 0 if current can wait for p, error code otherwise
1618 */
1619 static int smack_task_wait(struct task_struct *p)
1620 {
1621 struct smk_audit_info ad;
1622 char *sp = smk_of_current();
1623 char *tsp = smk_of_forked(task_security(p));
1624 int rc;
1625
1626 /* we don't log here, we can be overriden */
1627 rc = smk_access(tsp, sp, MAY_WRITE, NULL);
1628 if (rc == 0)
1629 goto out_log;
1630
1631 /*
1632 * Allow the operation to succeed if either task
1633 * has privilege to perform operations that might
1634 * account for the smack labels having gotten to
1635 * be different in the first place.
1636 *
1637 * This breaks the strict subject/object access
1638 * control ideal, taking the object's privilege
1639 * state into account in the decision as well as
1640 * the smack value.
1641 */
1642 if (capable(CAP_MAC_OVERRIDE) || has_capability(p, CAP_MAC_OVERRIDE))
1643 rc = 0;
1644 /* we log only if we didn't get overriden */
1645 out_log:
1646 smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_TASK);
1647 smk_ad_setfield_u_tsk(&ad, p);
1648 smack_log(tsp, sp, MAY_WRITE, rc, &ad);
1649 return rc;
1650 }
1651
1652 /**
1653 * smack_task_to_inode - copy task smack into the inode blob
1654 * @p: task to copy from
1655 * @inode: inode to copy to
1656 *
1657 * Sets the smack pointer in the inode security blob
1658 */
1659 static void smack_task_to_inode(struct task_struct *p, struct inode *inode)
1660 {
1661 struct inode_smack *isp = inode->i_security;
1662 isp->smk_inode = smk_of_task(task_security(p));
1663 }
1664
1665 /*
1666 * Socket hooks.
1667 */
1668
1669 /**
1670 * smack_sk_alloc_security - Allocate a socket blob
1671 * @sk: the socket
1672 * @family: unused
1673 * @gfp_flags: memory allocation flags
1674 *
1675 * Assign Smack pointers to current
1676 *
1677 * Returns 0 on success, -ENOMEM is there's no memory
1678 */
1679 static int smack_sk_alloc_security(struct sock *sk, int family, gfp_t gfp_flags)
1680 {
1681 char *csp = smk_of_current();
1682 struct socket_smack *ssp;
1683
1684 ssp = kzalloc(sizeof(struct socket_smack), gfp_flags);
1685 if (ssp == NULL)
1686 return -ENOMEM;
1687
1688 ssp->smk_in = csp;
1689 ssp->smk_out = csp;
1690 ssp->smk_packet[0] = '\0';
1691
1692 sk->sk_security = ssp;
1693
1694 return 0;
1695 }
1696
1697 /**
1698 * smack_sk_free_security - Free a socket blob
1699 * @sk: the socket
1700 *
1701 * Clears the blob pointer
1702 */
1703 static void smack_sk_free_security(struct sock *sk)
1704 {
1705 kfree(sk->sk_security);
1706 }
1707
1708 /**
1709 * smack_host_label - check host based restrictions
1710 * @sip: the object end
1711 *
1712 * looks for host based access restrictions
1713 *
1714 * This version will only be appropriate for really small sets of single label
1715 * hosts. The caller is responsible for ensuring that the RCU read lock is
1716 * taken before calling this function.
1717 *
1718 * Returns the label of the far end or NULL if it's not special.
1719 */
1720 static char *smack_host_label(struct sockaddr_in *sip)
1721 {
1722 struct smk_netlbladdr *snp;
1723 struct in_addr *siap = &sip->sin_addr;
1724
1725 if (siap->s_addr == 0)
1726 return NULL;
1727
1728 list_for_each_entry_rcu(snp, &smk_netlbladdr_list, list)
1729 /*
1730 * we break after finding the first match because
1731 * the list is sorted from longest to shortest mask
1732 * so we have found the most specific match
1733 */
1734 if ((&snp->smk_host.sin_addr)->s_addr ==
1735 (siap->s_addr & (&snp->smk_mask)->s_addr)) {
1736 /* we have found the special CIPSO option */
1737 if (snp->smk_label == smack_cipso_option)
1738 return NULL;
1739 return snp->smk_label;
1740 }
1741
1742 return NULL;
1743 }
1744
1745 /**
1746 * smack_set_catset - convert a capset to netlabel mls categories
1747 * @catset: the Smack categories
1748 * @sap: where to put the netlabel categories
1749 *
1750 * Allocates and fills attr.mls.cat
1751 */
1752 static void smack_set_catset(char *catset, struct netlbl_lsm_secattr *sap)
1753 {
1754 unsigned char *cp;
1755 unsigned char m;
1756 int cat;
1757 int rc;
1758 int byte;
1759
1760 if (!catset)
1761 return;
1762
1763 sap->flags |= NETLBL_SECATTR_MLS_CAT;
1764 sap->attr.mls.cat = netlbl_secattr_catmap_alloc(GFP_ATOMIC);
1765 sap->attr.mls.cat->startbit = 0;
1766
1767 for (cat = 1, cp = catset, byte = 0; byte < SMK_LABELLEN; cp++, byte++)
1768 for (m = 0x80; m != 0; m >>= 1, cat++) {
1769 if ((m & *cp) == 0)
1770 continue;
1771 rc = netlbl_secattr_catmap_setbit(sap->attr.mls.cat,
1772 cat, GFP_ATOMIC);
1773 }
1774 }
1775
1776 /**
1777 * smack_to_secattr - fill a secattr from a smack value
1778 * @smack: the smack value
1779 * @nlsp: where the result goes
1780 *
1781 * Casey says that CIPSO is good enough for now.
1782 * It can be used to effect.
1783 * It can also be abused to effect when necessary.
1784 * Appologies to the TSIG group in general and GW in particular.
1785 */
1786 static void smack_to_secattr(char *smack, struct netlbl_lsm_secattr *nlsp)
1787 {
1788 struct smack_cipso cipso;
1789 int rc;
1790
1791 nlsp->domain = smack;
1792 nlsp->flags = NETLBL_SECATTR_DOMAIN | NETLBL_SECATTR_MLS_LVL;
1793
1794 rc = smack_to_cipso(smack, &cipso);
1795 if (rc == 0) {
1796 nlsp->attr.mls.lvl = cipso.smk_level;
1797 smack_set_catset(cipso.smk_catset, nlsp);
1798 } else {
1799 nlsp->attr.mls.lvl = smack_cipso_direct;
1800 smack_set_catset(smack, nlsp);
1801 }
1802 }
1803
1804 /**
1805 * smack_netlabel - Set the secattr on a socket
1806 * @sk: the socket
1807 * @labeled: socket label scheme
1808 *
1809 * Convert the outbound smack value (smk_out) to a
1810 * secattr and attach it to the socket.
1811 *
1812 * Returns 0 on success or an error code
1813 */
1814 static int smack_netlabel(struct sock *sk, int labeled)
1815 {
1816 struct socket_smack *ssp = sk->sk_security;
1817 struct netlbl_lsm_secattr secattr;
1818 int rc = 0;
1819
1820 /*
1821 * Usually the netlabel code will handle changing the
1822 * packet labeling based on the label.
1823 * The case of a single label host is different, because
1824 * a single label host should never get a labeled packet
1825 * even though the label is usually associated with a packet
1826 * label.
1827 */
1828 local_bh_disable();
1829 bh_lock_sock_nested(sk);
1830
1831 if (ssp->smk_out == smack_net_ambient ||
1832 labeled == SMACK_UNLABELED_SOCKET)
1833 netlbl_sock_delattr(sk);
1834 else {
1835 netlbl_secattr_init(&secattr);
1836 smack_to_secattr(ssp->smk_out, &secattr);
1837 rc = netlbl_sock_setattr(sk, sk->sk_family, &secattr);
1838 netlbl_secattr_destroy(&secattr);
1839 }
1840
1841 bh_unlock_sock(sk);
1842 local_bh_enable();
1843
1844 return rc;
1845 }
1846
1847 /**
1848 * smack_netlbel_send - Set the secattr on a socket and perform access checks
1849 * @sk: the socket
1850 * @sap: the destination address
1851 *
1852 * Set the correct secattr for the given socket based on the destination
1853 * address and perform any outbound access checks needed.
1854 *
1855 * Returns 0 on success or an error code.
1856 *
1857 */
1858 static int smack_netlabel_send(struct sock *sk, struct sockaddr_in *sap)
1859 {
1860 int rc;
1861 int sk_lbl;
1862 char *hostsp;
1863 struct socket_smack *ssp = sk->sk_security;
1864 struct smk_audit_info ad;
1865
1866 rcu_read_lock();
1867 hostsp = smack_host_label(sap);
1868 if (hostsp != NULL) {
1869 sk_lbl = SMACK_UNLABELED_SOCKET;
1870 #ifdef CONFIG_AUDIT
1871 smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_NET);
1872 ad.a.u.net.family = sap->sin_family;
1873 ad.a.u.net.dport = sap->sin_port;
1874 ad.a.u.net.v4info.daddr = sap->sin_addr.s_addr;
1875 #endif
1876 rc = smk_access(ssp->smk_out, hostsp, MAY_WRITE, &ad);
1877 } else {
1878 sk_lbl = SMACK_CIPSO_SOCKET;
1879 rc = 0;
1880 }
1881 rcu_read_unlock();
1882 if (rc != 0)
1883 return rc;
1884
1885 return smack_netlabel(sk, sk_lbl);
1886 }
1887
1888 /**
1889 * smack_inode_setsecurity - set smack xattrs
1890 * @inode: the object
1891 * @name: attribute name
1892 * @value: attribute value
1893 * @size: size of the attribute
1894 * @flags: unused
1895 *
1896 * Sets the named attribute in the appropriate blob
1897 *
1898 * Returns 0 on success, or an error code
1899 */
1900 static int smack_inode_setsecurity(struct inode *inode, const char *name,
1901 const void *value, size_t size, int flags)
1902 {
1903 char *sp;
1904 struct inode_smack *nsp = inode->i_security;
1905 struct socket_smack *ssp;
1906 struct socket *sock;
1907 int rc = 0;
1908
1909 if (value == NULL || size > SMK_LABELLEN || size == 0)
1910 return -EACCES;
1911
1912 sp = smk_import(value, size);
1913 if (sp == NULL)
1914 return -EINVAL;
1915
1916 if (strcmp(name, XATTR_SMACK_SUFFIX) == 0) {
1917 nsp->smk_inode = sp;
1918 nsp->smk_flags |= SMK_INODE_INSTANT;
1919 return 0;
1920 }
1921 /*
1922 * The rest of the Smack xattrs are only on sockets.
1923 */
1924 if (inode->i_sb->s_magic != SOCKFS_MAGIC)
1925 return -EOPNOTSUPP;
1926
1927 sock = SOCKET_I(inode);
1928 if (sock == NULL || sock->sk == NULL)
1929 return -EOPNOTSUPP;
1930
1931 ssp = sock->sk->sk_security;
1932
1933 if (strcmp(name, XATTR_SMACK_IPIN) == 0)
1934 ssp->smk_in = sp;
1935 else if (strcmp(name, XATTR_SMACK_IPOUT) == 0) {
1936 ssp->smk_out = sp;
1937 if (sock->sk->sk_family != PF_UNIX) {
1938 rc = smack_netlabel(sock->sk, SMACK_CIPSO_SOCKET);
1939 if (rc != 0)
1940 printk(KERN_WARNING
1941 "Smack: \"%s\" netlbl error %d.\n",
1942 __func__, -rc);
1943 }
1944 } else
1945 return -EOPNOTSUPP;
1946
1947 return 0;
1948 }
1949
1950 /**
1951 * smack_socket_post_create - finish socket setup
1952 * @sock: the socket
1953 * @family: protocol family
1954 * @type: unused
1955 * @protocol: unused
1956 * @kern: unused
1957 *
1958 * Sets the netlabel information on the socket
1959 *
1960 * Returns 0 on success, and error code otherwise
1961 */
1962 static int smack_socket_post_create(struct socket *sock, int family,
1963 int type, int protocol, int kern)
1964 {
1965 if (family != PF_INET || sock->sk == NULL)
1966 return 0;
1967 /*
1968 * Set the outbound netlbl.
1969 */
1970 return smack_netlabel(sock->sk, SMACK_CIPSO_SOCKET);
1971 }
1972
1973 /**
1974 * smack_socket_connect - connect access check
1975 * @sock: the socket
1976 * @sap: the other end
1977 * @addrlen: size of sap
1978 *
1979 * Verifies that a connection may be possible
1980 *
1981 * Returns 0 on success, and error code otherwise
1982 */
1983 static int smack_socket_connect(struct socket *sock, struct sockaddr *sap,
1984 int addrlen)
1985 {
1986 if (sock->sk == NULL || sock->sk->sk_family != PF_INET)
1987 return 0;
1988 if (addrlen < sizeof(struct sockaddr_in))
1989 return -EINVAL;
1990
1991 return smack_netlabel_send(sock->sk, (struct sockaddr_in *)sap);
1992 }
1993
1994 /**
1995 * smack_flags_to_may - convert S_ to MAY_ values
1996 * @flags: the S_ value
1997 *
1998 * Returns the equivalent MAY_ value
1999 */
2000 static int smack_flags_to_may(int flags)
2001 {
2002 int may = 0;
2003
2004 if (flags & S_IRUGO)
2005 may |= MAY_READ;
2006 if (flags & S_IWUGO)
2007 may |= MAY_WRITE;
2008 if (flags & S_IXUGO)
2009 may |= MAY_EXEC;
2010
2011 return may;
2012 }
2013
2014 /**
2015 * smack_msg_msg_alloc_security - Set the security blob for msg_msg
2016 * @msg: the object
2017 *
2018 * Returns 0
2019 */
2020 static int smack_msg_msg_alloc_security(struct msg_msg *msg)
2021 {
2022 msg->security = smk_of_current();
2023 return 0;
2024 }
2025
2026 /**
2027 * smack_msg_msg_free_security - Clear the security blob for msg_msg
2028 * @msg: the object
2029 *
2030 * Clears the blob pointer
2031 */
2032 static void smack_msg_msg_free_security(struct msg_msg *msg)
2033 {
2034 msg->security = NULL;
2035 }
2036
2037 /**
2038 * smack_of_shm - the smack pointer for the shm
2039 * @shp: the object
2040 *
2041 * Returns a pointer to the smack value
2042 */
2043 static char *smack_of_shm(struct shmid_kernel *shp)
2044 {
2045 return (char *)shp->shm_perm.security;
2046 }
2047
2048 /**
2049 * smack_shm_alloc_security - Set the security blob for shm
2050 * @shp: the object
2051 *
2052 * Returns 0
2053 */
2054 static int smack_shm_alloc_security(struct shmid_kernel *shp)
2055 {
2056 struct kern_ipc_perm *isp = &shp->shm_perm;
2057
2058 isp->security = smk_of_current();
2059 return 0;
2060 }
2061
2062 /**
2063 * smack_shm_free_security - Clear the security blob for shm
2064 * @shp: the object
2065 *
2066 * Clears the blob pointer
2067 */
2068 static void smack_shm_free_security(struct shmid_kernel *shp)
2069 {
2070 struct kern_ipc_perm *isp = &shp->shm_perm;
2071
2072 isp->security = NULL;
2073 }
2074
2075 /**
2076 * smk_curacc_shm : check if current has access on shm
2077 * @shp : the object
2078 * @access : access requested
2079 *
2080 * Returns 0 if current has the requested access, error code otherwise
2081 */
2082 static int smk_curacc_shm(struct shmid_kernel *shp, int access)
2083 {
2084 char *ssp = smack_of_shm(shp);
2085 struct smk_audit_info ad;
2086
2087 #ifdef CONFIG_AUDIT
2088 smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_IPC);
2089 ad.a.u.ipc_id = shp->shm_perm.id;
2090 #endif
2091 return smk_curacc(ssp, access, &ad);
2092 }
2093
2094 /**
2095 * smack_shm_associate - Smack access check for shm
2096 * @shp: the object
2097 * @shmflg: access requested
2098 *
2099 * Returns 0 if current has the requested access, error code otherwise
2100 */
2101 static int smack_shm_associate(struct shmid_kernel *shp, int shmflg)
2102 {
2103 int may;
2104
2105 may = smack_flags_to_may(shmflg);
2106 return smk_curacc_shm(shp, may);
2107 }
2108
2109 /**
2110 * smack_shm_shmctl - Smack access check for shm
2111 * @shp: the object
2112 * @cmd: what it wants to do
2113 *
2114 * Returns 0 if current has the requested access, error code otherwise
2115 */
2116 static int smack_shm_shmctl(struct shmid_kernel *shp, int cmd)
2117 {
2118 int may;
2119
2120 switch (cmd) {
2121 case IPC_STAT:
2122 case SHM_STAT:
2123 may = MAY_READ;
2124 break;
2125 case IPC_SET:
2126 case SHM_LOCK:
2127 case SHM_UNLOCK:
2128 case IPC_RMID:
2129 may = MAY_READWRITE;
2130 break;
2131 case IPC_INFO:
2132 case SHM_INFO:
2133 /*
2134 * System level information.
2135 */
2136 return 0;
2137 default:
2138 return -EINVAL;
2139 }
2140 return smk_curacc_shm(shp, may);
2141 }
2142
2143 /**
2144 * smack_shm_shmat - Smack access for shmat
2145 * @shp: the object
2146 * @shmaddr: unused
2147 * @shmflg: access requested
2148 *
2149 * Returns 0 if current has the requested access, error code otherwise
2150 */
2151 static int smack_shm_shmat(struct shmid_kernel *shp, char __user *shmaddr,
2152 int shmflg)
2153 {
2154 int may;
2155
2156 may = smack_flags_to_may(shmflg);
2157 return smk_curacc_shm(shp, may);
2158 }
2159
2160 /**
2161 * smack_of_sem - the smack pointer for the sem
2162 * @sma: the object
2163 *
2164 * Returns a pointer to the smack value
2165 */
2166 static char *smack_of_sem(struct sem_array *sma)
2167 {
2168 return (char *)sma->sem_perm.security;
2169 }
2170
2171 /**
2172 * smack_sem_alloc_security - Set the security blob for sem
2173 * @sma: the object
2174 *
2175 * Returns 0
2176 */
2177 static int smack_sem_alloc_security(struct sem_array *sma)
2178 {
2179 struct kern_ipc_perm *isp = &sma->sem_perm;
2180
2181 isp->security = smk_of_current();
2182 return 0;
2183 }
2184
2185 /**
2186 * smack_sem_free_security - Clear the security blob for sem
2187 * @sma: the object
2188 *
2189 * Clears the blob pointer
2190 */
2191 static void smack_sem_free_security(struct sem_array *sma)
2192 {
2193 struct kern_ipc_perm *isp = &sma->sem_perm;
2194
2195 isp->security = NULL;
2196 }
2197
2198 /**
2199 * smk_curacc_sem : check if current has access on sem
2200 * @sma : the object
2201 * @access : access requested
2202 *
2203 * Returns 0 if current has the requested access, error code otherwise
2204 */
2205 static int smk_curacc_sem(struct sem_array *sma, int access)
2206 {
2207 char *ssp = smack_of_sem(sma);
2208 struct smk_audit_info ad;
2209
2210 #ifdef CONFIG_AUDIT
2211 smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_IPC);
2212 ad.a.u.ipc_id = sma->sem_perm.id;
2213 #endif
2214 return smk_curacc(ssp, access, &ad);
2215 }
2216
2217 /**
2218 * smack_sem_associate - Smack access check for sem
2219 * @sma: the object
2220 * @semflg: access requested
2221 *
2222 * Returns 0 if current has the requested access, error code otherwise
2223 */
2224 static int smack_sem_associate(struct sem_array *sma, int semflg)
2225 {
2226 int may;
2227
2228 may = smack_flags_to_may(semflg);
2229 return smk_curacc_sem(sma, may);
2230 }
2231
2232 /**
2233 * smack_sem_shmctl - Smack access check for sem
2234 * @sma: the object
2235 * @cmd: what it wants to do
2236 *
2237 * Returns 0 if current has the requested access, error code otherwise
2238 */
2239 static int smack_sem_semctl(struct sem_array *sma, int cmd)
2240 {
2241 int may;
2242
2243 switch (cmd) {
2244 case GETPID:
2245 case GETNCNT:
2246 case GETZCNT:
2247 case GETVAL:
2248 case GETALL:
2249 case IPC_STAT:
2250 case SEM_STAT:
2251 may = MAY_READ;
2252 break;
2253 case SETVAL:
2254 case SETALL:
2255 case IPC_RMID:
2256 case IPC_SET:
2257 may = MAY_READWRITE;
2258 break;
2259 case IPC_INFO:
2260 case SEM_INFO:
2261 /*
2262 * System level information
2263 */
2264 return 0;
2265 default:
2266 return -EINVAL;
2267 }
2268
2269 return smk_curacc_sem(sma, may);
2270 }
2271
2272 /**
2273 * smack_sem_semop - Smack checks of semaphore operations
2274 * @sma: the object
2275 * @sops: unused
2276 * @nsops: unused
2277 * @alter: unused
2278 *
2279 * Treated as read and write in all cases.
2280 *
2281 * Returns 0 if access is allowed, error code otherwise
2282 */
2283 static int smack_sem_semop(struct sem_array *sma, struct sembuf *sops,
2284 unsigned nsops, int alter)
2285 {
2286 return smk_curacc_sem(sma, MAY_READWRITE);
2287 }
2288
2289 /**
2290 * smack_msg_alloc_security - Set the security blob for msg
2291 * @msq: the object
2292 *
2293 * Returns 0
2294 */
2295 static int smack_msg_queue_alloc_security(struct msg_queue *msq)
2296 {
2297 struct kern_ipc_perm *kisp = &msq->q_perm;
2298
2299 kisp->security = smk_of_current();
2300 return 0;
2301 }
2302
2303 /**
2304 * smack_msg_free_security - Clear the security blob for msg
2305 * @msq: the object
2306 *
2307 * Clears the blob pointer
2308 */
2309 static void smack_msg_queue_free_security(struct msg_queue *msq)
2310 {
2311 struct kern_ipc_perm *kisp = &msq->q_perm;
2312
2313 kisp->security = NULL;
2314 }
2315
2316 /**
2317 * smack_of_msq - the smack pointer for the msq
2318 * @msq: the object
2319 *
2320 * Returns a pointer to the smack value
2321 */
2322 static char *smack_of_msq(struct msg_queue *msq)
2323 {
2324 return (char *)msq->q_perm.security;
2325 }
2326
2327 /**
2328 * smk_curacc_msq : helper to check if current has access on msq
2329 * @msq : the msq
2330 * @access : access requested
2331 *
2332 * return 0 if current has access, error otherwise
2333 */
2334 static int smk_curacc_msq(struct msg_queue *msq, int access)
2335 {
2336 char *msp = smack_of_msq(msq);
2337 struct smk_audit_info ad;
2338
2339 #ifdef CONFIG_AUDIT
2340 smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_IPC);
2341 ad.a.u.ipc_id = msq->q_perm.id;
2342 #endif
2343 return smk_curacc(msp, access, &ad);
2344 }
2345
2346 /**
2347 * smack_msg_queue_associate - Smack access check for msg_queue
2348 * @msq: the object
2349 * @msqflg: access requested
2350 *
2351 * Returns 0 if current has the requested access, error code otherwise
2352 */
2353 static int smack_msg_queue_associate(struct msg_queue *msq, int msqflg)
2354 {
2355 int may;
2356
2357 may = smack_flags_to_may(msqflg);
2358 return smk_curacc_msq(msq, may);
2359 }
2360
2361 /**
2362 * smack_msg_queue_msgctl - Smack access check for msg_queue
2363 * @msq: the object
2364 * @cmd: what it wants to do
2365 *
2366 * Returns 0 if current has the requested access, error code otherwise
2367 */
2368 static int smack_msg_queue_msgctl(struct msg_queue *msq, int cmd)
2369 {
2370 int may;
2371
2372 switch (cmd) {
2373 case IPC_STAT:
2374 case MSG_STAT:
2375 may = MAY_READ;
2376 break;
2377 case IPC_SET:
2378 case IPC_RMID:
2379 may = MAY_READWRITE;
2380 break;
2381 case IPC_INFO:
2382 case MSG_INFO:
2383 /*
2384 * System level information
2385 */
2386 return 0;
2387 default:
2388 return -EINVAL;
2389 }
2390
2391 return smk_curacc_msq(msq, may);
2392 }
2393
2394 /**
2395 * smack_msg_queue_msgsnd - Smack access check for msg_queue
2396 * @msq: the object
2397 * @msg: unused
2398 * @msqflg: access requested
2399 *
2400 * Returns 0 if current has the requested access, error code otherwise
2401 */
2402 static int smack_msg_queue_msgsnd(struct msg_queue *msq, struct msg_msg *msg,
2403 int msqflg)
2404 {
2405 int may;
2406
2407 may = smack_flags_to_may(msqflg);
2408 return smk_curacc_msq(msq, may);
2409 }
2410
2411 /**
2412 * smack_msg_queue_msgsnd - Smack access check for msg_queue
2413 * @msq: the object
2414 * @msg: unused
2415 * @target: unused
2416 * @type: unused
2417 * @mode: unused
2418 *
2419 * Returns 0 if current has read and write access, error code otherwise
2420 */
2421 static int smack_msg_queue_msgrcv(struct msg_queue *msq, struct msg_msg *msg,
2422 struct task_struct *target, long type, int mode)
2423 {
2424 return smk_curacc_msq(msq, MAY_READWRITE);
2425 }
2426
2427 /**
2428 * smack_ipc_permission - Smack access for ipc_permission()
2429 * @ipp: the object permissions
2430 * @flag: access requested
2431 *
2432 * Returns 0 if current has read and write access, error code otherwise
2433 */
2434 static int smack_ipc_permission(struct kern_ipc_perm *ipp, short flag)
2435 {
2436 char *isp = ipp->security;
2437 int may = smack_flags_to_may(flag);
2438 struct smk_audit_info ad;
2439
2440 #ifdef CONFIG_AUDIT
2441 smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_IPC);
2442 ad.a.u.ipc_id = ipp->id;
2443 #endif
2444 return smk_curacc(isp, may, &ad);
2445 }
2446
2447 /**
2448 * smack_ipc_getsecid - Extract smack security id
2449 * @ipp: the object permissions
2450 * @secid: where result will be saved
2451 */
2452 static void smack_ipc_getsecid(struct kern_ipc_perm *ipp, u32 *secid)
2453 {
2454 char *smack = ipp->security;
2455
2456 *secid = smack_to_secid(smack);
2457 }
2458
2459 /**
2460 * smack_d_instantiate - Make sure the blob is correct on an inode
2461 * @opt_dentry: dentry where inode will be attached
2462 * @inode: the object
2463 *
2464 * Set the inode's security blob if it hasn't been done already.
2465 */
2466 static void smack_d_instantiate(struct dentry *opt_dentry, struct inode *inode)
2467 {
2468 struct super_block *sbp;
2469 struct superblock_smack *sbsp;
2470 struct inode_smack *isp;
2471 char *csp = smk_of_current();
2472 char *fetched;
2473 char *final;
2474 char trattr[TRANS_TRUE_SIZE];
2475 int transflag = 0;
2476 struct dentry *dp;
2477
2478 if (inode == NULL)
2479 return;
2480
2481 isp = inode->i_security;
2482
2483 mutex_lock(&isp->smk_lock);
2484 /*
2485 * If the inode is already instantiated
2486 * take the quick way out
2487 */
2488 if (isp->smk_flags & SMK_INODE_INSTANT)
2489 goto unlockandout;
2490
2491 sbp = inode->i_sb;
2492 sbsp = sbp->s_security;
2493 /*
2494 * We're going to use the superblock default label
2495 * if there's no label on the file.
2496 */
2497 final = sbsp->smk_default;
2498
2499 /*
2500 * If this is the root inode the superblock
2501 * may be in the process of initialization.
2502 * If that is the case use the root value out
2503 * of the superblock.
2504 */
2505 if (opt_dentry->d_parent == opt_dentry) {
2506 isp->smk_inode = sbsp->smk_root;
2507 isp->smk_flags |= SMK_INODE_INSTANT;
2508 goto unlockandout;
2509 }
2510
2511 /*
2512 * This is pretty hackish.
2513 * Casey says that we shouldn't have to do
2514 * file system specific code, but it does help
2515 * with keeping it simple.
2516 */
2517 switch (sbp->s_magic) {
2518 case SMACK_MAGIC:
2519 /*
2520 * Casey says that it's a little embarassing
2521 * that the smack file system doesn't do
2522 * extended attributes.
2523 */
2524 final = smack_known_star.smk_known;
2525 break;
2526 case PIPEFS_MAGIC:
2527 /*
2528 * Casey says pipes are easy (?)
2529 */
2530 final = smack_known_star.smk_known;
2531 break;
2532 case DEVPTS_SUPER_MAGIC:
2533 /*
2534 * devpts seems content with the label of the task.
2535 * Programs that change smack have to treat the
2536 * pty with respect.
2537 */
2538 final = csp;
2539 break;
2540 case SOCKFS_MAGIC:
2541 /*
2542 * Socket access is controlled by the socket
2543 * structures associated with the task involved.
2544 */
2545 final = smack_known_star.smk_known;
2546 break;
2547 case PROC_SUPER_MAGIC:
2548 /*
2549 * Casey says procfs appears not to care.
2550 * The superblock default suffices.
2551 */
2552 break;
2553 case TMPFS_MAGIC:
2554 /*
2555 * Device labels should come from the filesystem,
2556 * but watch out, because they're volitile,
2557 * getting recreated on every reboot.
2558 */
2559 final = smack_known_star.smk_known;
2560 /*
2561 * No break.
2562 *
2563 * If a smack value has been set we want to use it,
2564 * but since tmpfs isn't giving us the opportunity
2565 * to set mount options simulate setting the
2566 * superblock default.
2567 */
2568 default:
2569 /*
2570 * This isn't an understood special case.
2571 * Get the value from the xattr.
2572 */
2573
2574 /*
2575 * UNIX domain sockets use lower level socket data.
2576 */
2577 if (S_ISSOCK(inode->i_mode)) {
2578 final = smack_known_star.smk_known;
2579 break;
2580 }
2581 /*
2582 * No xattr support means, alas, no SMACK label.
2583 * Use the aforeapplied default.
2584 * It would be curious if the label of the task
2585 * does not match that assigned.
2586 */
2587 if (inode->i_op->getxattr == NULL)
2588 break;
2589 /*
2590 * Get the dentry for xattr.
2591 */
2592 dp = dget(opt_dentry);
2593 fetched = smk_fetch(XATTR_NAME_SMACK, inode, dp);
2594 if (fetched != NULL) {
2595 final = fetched;
2596 if (S_ISDIR(inode->i_mode)) {
2597 trattr[0] = '\0';
2598 inode->i_op->getxattr(dp,
2599 XATTR_NAME_SMACKTRANSMUTE,
2600 trattr, TRANS_TRUE_SIZE);
2601 if (strncmp(trattr, TRANS_TRUE,
2602 TRANS_TRUE_SIZE) == 0)
2603 transflag = SMK_INODE_TRANSMUTE;
2604 }
2605 }
2606 isp->smk_task = smk_fetch(XATTR_NAME_SMACKEXEC, inode, dp);
2607 isp->smk_mmap = smk_fetch(XATTR_NAME_SMACKMMAP, inode, dp);
2608
2609 dput(dp);
2610 break;
2611 }
2612
2613 if (final == NULL)
2614 isp->smk_inode = csp;
2615 else
2616 isp->smk_inode = final;
2617
2618 isp->smk_flags |= (SMK_INODE_INSTANT | transflag);
2619
2620 unlockandout:
2621 mutex_unlock(&isp->smk_lock);
2622 return;
2623 }
2624
2625 /**
2626 * smack_getprocattr - Smack process attribute access
2627 * @p: the object task
2628 * @name: the name of the attribute in /proc/.../attr
2629 * @value: where to put the result
2630 *
2631 * Places a copy of the task Smack into value
2632 *
2633 * Returns the length of the smack label or an error code
2634 */
2635 static int smack_getprocattr(struct task_struct *p, char *name, char **value)
2636 {
2637 char *cp;
2638 int slen;
2639
2640 if (strcmp(name, "current") != 0)
2641 return -EINVAL;
2642
2643 cp = kstrdup(smk_of_task(task_security(p)), GFP_KERNEL);
2644 if (cp == NULL)
2645 return -ENOMEM;
2646
2647 slen = strlen(cp);
2648 *value = cp;
2649 return slen;
2650 }
2651
2652 /**
2653 * smack_setprocattr - Smack process attribute setting
2654 * @p: the object task
2655 * @name: the name of the attribute in /proc/.../attr
2656 * @value: the value to set
2657 * @size: the size of the value
2658 *
2659 * Sets the Smack value of the task. Only setting self
2660 * is permitted and only with privilege
2661 *
2662 * Returns the length of the smack label or an error code
2663 */
2664 static int smack_setprocattr(struct task_struct *p, char *name,
2665 void *value, size_t size)
2666 {
2667 int rc;
2668 struct task_smack *tsp;
2669 struct task_smack *oldtsp;
2670 struct cred *new;
2671 char *newsmack;
2672
2673 /*
2674 * Changing another process' Smack value is too dangerous
2675 * and supports no sane use case.
2676 */
2677 if (p != current)
2678 return -EPERM;
2679
2680 if (!capable(CAP_MAC_ADMIN))
2681 return -EPERM;
2682
2683 if (value == NULL || size == 0 || size >= SMK_LABELLEN)
2684 return -EINVAL;
2685
2686 if (strcmp(name, "current") != 0)
2687 return -EINVAL;
2688
2689 newsmack = smk_import(value, size);
2690 if (newsmack == NULL)
2691 return -EINVAL;
2692
2693 /*
2694 * No process is ever allowed the web ("@") label.
2695 */
2696 if (newsmack == smack_known_web.smk_known)
2697 return -EPERM;
2698
2699 oldtsp = p->cred->security;
2700 new = prepare_creds();
2701 if (new == NULL)
2702 return -ENOMEM;
2703
2704 tsp = new_task_smack(newsmack, oldtsp->smk_forked, GFP_KERNEL);
2705 if (tsp == NULL) {
2706 kfree(new);
2707 return -ENOMEM;
2708 }
2709 rc = smk_copy_rules(&tsp->smk_rules, &oldtsp->smk_rules, GFP_KERNEL);
2710 if (rc != 0)
2711 return rc;
2712
2713 new->security = tsp;
2714 commit_creds(new);
2715 return size;
2716 }
2717
2718 /**
2719 * smack_unix_stream_connect - Smack access on UDS
2720 * @sock: one sock
2721 * @other: the other sock
2722 * @newsk: unused
2723 *
2724 * Return 0 if a subject with the smack of sock could access
2725 * an object with the smack of other, otherwise an error code
2726 */
2727 static int smack_unix_stream_connect(struct sock *sock,
2728 struct sock *other, struct sock *newsk)
2729 {
2730 struct socket_smack *ssp = sock->sk_security;
2731 struct socket_smack *osp = other->sk_security;
2732 struct smk_audit_info ad;
2733 int rc = 0;
2734
2735 smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_NET);
2736 smk_ad_setfield_u_net_sk(&ad, other);
2737
2738 if (!capable(CAP_MAC_OVERRIDE))
2739 rc = smk_access(ssp->smk_out, osp->smk_in, MAY_WRITE, &ad);
2740
2741 return rc;
2742 }
2743
2744 /**
2745 * smack_unix_may_send - Smack access on UDS
2746 * @sock: one socket
2747 * @other: the other socket
2748 *
2749 * Return 0 if a subject with the smack of sock could access
2750 * an object with the smack of other, otherwise an error code
2751 */
2752 static int smack_unix_may_send(struct socket *sock, struct socket *other)
2753 {
2754 struct socket_smack *ssp = sock->sk->sk_security;
2755 struct socket_smack *osp = other->sk->sk_security;
2756 struct smk_audit_info ad;
2757 int rc = 0;
2758
2759 smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_NET);
2760 smk_ad_setfield_u_net_sk(&ad, other->sk);
2761
2762 if (!capable(CAP_MAC_OVERRIDE))
2763 rc = smk_access(ssp->smk_out, osp->smk_in, MAY_WRITE, &ad);
2764
2765 return rc;
2766 }
2767
2768 /**
2769 * smack_socket_sendmsg - Smack check based on destination host
2770 * @sock: the socket
2771 * @msg: the message
2772 * @size: the size of the message
2773 *
2774 * Return 0 if the current subject can write to the destination
2775 * host. This is only a question if the destination is a single
2776 * label host.
2777 */
2778 static int smack_socket_sendmsg(struct socket *sock, struct msghdr *msg,
2779 int size)
2780 {
2781 struct sockaddr_in *sip = (struct sockaddr_in *) msg->msg_name;
2782
2783 /*
2784 * Perfectly reasonable for this to be NULL
2785 */
2786 if (sip == NULL || sip->sin_family != AF_INET)
2787 return 0;
2788
2789 return smack_netlabel_send(sock->sk, sip);
2790 }
2791
2792
2793 /**
2794 * smack_from_secattr - Convert a netlabel attr.mls.lvl/attr.mls.cat pair to smack
2795 * @sap: netlabel secattr
2796 * @sip: where to put the result
2797 *
2798 * Copies a smack label into sip
2799 */
2800 static void smack_from_secattr(struct netlbl_lsm_secattr *sap, char *sip)
2801 {
2802 char smack[SMK_LABELLEN];
2803 char *sp;
2804 int pcat;
2805
2806 if ((sap->flags & NETLBL_SECATTR_MLS_LVL) != 0) {
2807 /*
2808 * Looks like a CIPSO packet.
2809 * If there are flags but no level netlabel isn't
2810 * behaving the way we expect it to.
2811 *
2812 * Get the categories, if any
2813 * Without guidance regarding the smack value
2814 * for the packet fall back on the network
2815 * ambient value.
2816 */
2817 memset(smack, '\0', SMK_LABELLEN);
2818 if ((sap->flags & NETLBL_SECATTR_MLS_CAT) != 0)
2819 for (pcat = -1;;) {
2820 pcat = netlbl_secattr_catmap_walk(
2821 sap->attr.mls.cat, pcat + 1);
2822 if (pcat < 0)
2823 break;
2824 smack_catset_bit(pcat, smack);
2825 }
2826 /*
2827 * If it is CIPSO using smack direct mapping
2828 * we are already done. WeeHee.
2829 */
2830 if (sap->attr.mls.lvl == smack_cipso_direct) {
2831 memcpy(sip, smack, SMK_MAXLEN);
2832 return;
2833 }
2834 /*
2835 * Look it up in the supplied table if it is not
2836 * a direct mapping.
2837 */
2838 smack_from_cipso(sap->attr.mls.lvl, smack, sip);
2839 return;
2840 }
2841 if ((sap->flags & NETLBL_SECATTR_SECID) != 0) {
2842 /*
2843 * Looks like a fallback, which gives us a secid.
2844 */
2845 sp = smack_from_secid(sap->attr.secid);
2846 /*
2847 * This has got to be a bug because it is
2848 * impossible to specify a fallback without
2849 * specifying the label, which will ensure
2850 * it has a secid, and the only way to get a
2851 * secid is from a fallback.
2852 */
2853 BUG_ON(sp == NULL);
2854 strncpy(sip, sp, SMK_MAXLEN);
2855 return;
2856 }
2857 /*
2858 * Without guidance regarding the smack value
2859 * for the packet fall back on the network
2860 * ambient value.
2861 */
2862 strncpy(sip, smack_net_ambient, SMK_MAXLEN);
2863 return;
2864 }
2865
2866 /**
2867 * smack_socket_sock_rcv_skb - Smack packet delivery access check
2868 * @sk: socket
2869 * @skb: packet
2870 *
2871 * Returns 0 if the packet should be delivered, an error code otherwise
2872 */
2873 static int smack_socket_sock_rcv_skb(struct sock *sk, struct sk_buff *skb)
2874 {
2875 struct netlbl_lsm_secattr secattr;
2876 struct socket_smack *ssp = sk->sk_security;
2877 char smack[SMK_LABELLEN];
2878 char *csp;
2879 int rc;
2880 struct smk_audit_info ad;
2881 if (sk->sk_family != PF_INET && sk->sk_family != PF_INET6)
2882 return 0;
2883
2884 /*
2885 * Translate what netlabel gave us.
2886 */
2887 netlbl_secattr_init(&secattr);
2888
2889 rc = netlbl_skbuff_getattr(skb, sk->sk_family, &secattr);
2890 if (rc == 0) {
2891 smack_from_secattr(&secattr, smack);
2892 csp = smack;
2893 } else
2894 csp = smack_net_ambient;
2895
2896 netlbl_secattr_destroy(&secattr);
2897
2898 #ifdef CONFIG_AUDIT
2899 smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_NET);
2900 ad.a.u.net.family = sk->sk_family;
2901 ad.a.u.net.netif = skb->skb_iif;
2902 ipv4_skb_to_auditdata(skb, &ad.a, NULL);
2903 #endif
2904 /*
2905 * Receiving a packet requires that the other end
2906 * be able to write here. Read access is not required.
2907 * This is the simplist possible security model
2908 * for networking.
2909 */
2910 rc = smk_access(csp, ssp->smk_in, MAY_WRITE, &ad);
2911 if (rc != 0)
2912 netlbl_skbuff_err(skb, rc, 0);
2913 return rc;
2914 }
2915
2916 /**
2917 * smack_socket_getpeersec_stream - pull in packet label
2918 * @sock: the socket
2919 * @optval: user's destination
2920 * @optlen: size thereof
2921 * @len: max thereof
2922 *
2923 * returns zero on success, an error code otherwise
2924 */
2925 static int smack_socket_getpeersec_stream(struct socket *sock,
2926 char __user *optval,
2927 int __user *optlen, unsigned len)
2928 {
2929 struct socket_smack *ssp;
2930 int slen;
2931 int rc = 0;
2932
2933 ssp = sock->sk->sk_security;
2934 slen = strlen(ssp->smk_packet) + 1;
2935
2936 if (slen > len)
2937 rc = -ERANGE;
2938 else if (copy_to_user(optval, ssp->smk_packet, slen) != 0)
2939 rc = -EFAULT;
2940
2941 if (put_user(slen, optlen) != 0)
2942 rc = -EFAULT;
2943
2944 return rc;
2945 }
2946
2947
2948 /**
2949 * smack_socket_getpeersec_dgram - pull in packet label
2950 * @sock: the peer socket
2951 * @skb: packet data
2952 * @secid: pointer to where to put the secid of the packet
2953 *
2954 * Sets the netlabel socket state on sk from parent
2955 */
2956 static int smack_socket_getpeersec_dgram(struct socket *sock,
2957 struct sk_buff *skb, u32 *secid)
2958
2959 {
2960 struct netlbl_lsm_secattr secattr;
2961 struct socket_smack *sp;
2962 char smack[SMK_LABELLEN];
2963 int family = PF_UNSPEC;
2964 u32 s = 0; /* 0 is the invalid secid */
2965 int rc;
2966
2967 if (skb != NULL) {
2968 if (skb->protocol == htons(ETH_P_IP))
2969 family = PF_INET;
2970 else if (skb->protocol == htons(ETH_P_IPV6))
2971 family = PF_INET6;
2972 }
2973 if (family == PF_UNSPEC && sock != NULL)
2974 family = sock->sk->sk_family;
2975
2976 if (family == PF_UNIX) {
2977 sp = sock->sk->sk_security;
2978 s = smack_to_secid(sp->smk_out);
2979 } else if (family == PF_INET || family == PF_INET6) {
2980 /*
2981 * Translate what netlabel gave us.
2982 */
2983 netlbl_secattr_init(&secattr);
2984 rc = netlbl_skbuff_getattr(skb, family, &secattr);
2985 if (rc == 0) {
2986 smack_from_secattr(&secattr, smack);
2987 s = smack_to_secid(smack);
2988 }
2989 netlbl_secattr_destroy(&secattr);
2990 }
2991 *secid = s;
2992 if (s == 0)
2993 return -EINVAL;
2994 return 0;
2995 }
2996
2997 /**
2998 * smack_sock_graft - Initialize a newly created socket with an existing sock
2999 * @sk: child sock
3000 * @parent: parent socket
3001 *
3002 * Set the smk_{in,out} state of an existing sock based on the process that
3003 * is creating the new socket.
3004 */
3005 static void smack_sock_graft(struct sock *sk, struct socket *parent)
3006 {
3007 struct socket_smack *ssp;
3008
3009 if (sk == NULL ||
3010 (sk->sk_family != PF_INET && sk->sk_family != PF_INET6))
3011 return;
3012
3013 ssp = sk->sk_security;
3014 ssp->smk_in = ssp->smk_out = smk_of_current();
3015 /* cssp->smk_packet is already set in smack_inet_csk_clone() */
3016 }
3017
3018 /**
3019 * smack_inet_conn_request - Smack access check on connect
3020 * @sk: socket involved
3021 * @skb: packet
3022 * @req: unused
3023 *
3024 * Returns 0 if a task with the packet label could write to
3025 * the socket, otherwise an error code
3026 */
3027 static int smack_inet_conn_request(struct sock *sk, struct sk_buff *skb,
3028 struct request_sock *req)
3029 {
3030 u16 family = sk->sk_family;
3031 struct socket_smack *ssp = sk->sk_security;
3032 struct netlbl_lsm_secattr secattr;
3033 struct sockaddr_in addr;
3034 struct iphdr *hdr;
3035 char smack[SMK_LABELLEN];
3036 int rc;
3037 struct smk_audit_info ad;
3038
3039 /* handle mapped IPv4 packets arriving via IPv6 sockets */
3040 if (family == PF_INET6 && skb->protocol == htons(ETH_P_IP))
3041 family = PF_INET;
3042
3043 netlbl_secattr_init(&secattr);
3044 rc = netlbl_skbuff_getattr(skb, family, &secattr);
3045 if (rc == 0)
3046 smack_from_secattr(&secattr, smack);
3047 else
3048 strncpy(smack, smack_known_huh.smk_known, SMK_MAXLEN);
3049 netlbl_secattr_destroy(&secattr);
3050
3051 #ifdef CONFIG_AUDIT
3052 smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_NET);
3053 ad.a.u.net.family = family;
3054 ad.a.u.net.netif = skb->skb_iif;
3055 ipv4_skb_to_auditdata(skb, &ad.a, NULL);
3056 #endif
3057 /*
3058 * Receiving a packet requires that the other end be able to write
3059 * here. Read access is not required.
3060 */
3061 rc = smk_access(smack, ssp->smk_in, MAY_WRITE, &ad);
3062 if (rc != 0)
3063 return rc;
3064
3065 /*
3066 * Save the peer's label in the request_sock so we can later setup
3067 * smk_packet in the child socket so that SO_PEERCRED can report it.
3068 */
3069 req->peer_secid = smack_to_secid(smack);
3070
3071 /*
3072 * We need to decide if we want to label the incoming connection here
3073 * if we do we only need to label the request_sock and the stack will
3074 * propogate the wire-label to the sock when it is created.
3075 */
3076 hdr = ip_hdr(skb);
3077 addr.sin_addr.s_addr = hdr->saddr;
3078 rcu_read_lock();
3079 if (smack_host_label(&addr) == NULL) {
3080 rcu_read_unlock();
3081 netlbl_secattr_init(&secattr);
3082 smack_to_secattr(smack, &secattr);
3083 rc = netlbl_req_setattr(req, &secattr);
3084 netlbl_secattr_destroy(&secattr);
3085 } else {
3086 rcu_read_unlock();
3087 netlbl_req_delattr(req);
3088 }
3089
3090 return rc;
3091 }
3092
3093 /**
3094 * smack_inet_csk_clone - Copy the connection information to the new socket
3095 * @sk: the new socket
3096 * @req: the connection's request_sock
3097 *
3098 * Transfer the connection's peer label to the newly created socket.
3099 */
3100 static void smack_inet_csk_clone(struct sock *sk,
3101 const struct request_sock *req)
3102 {
3103 struct socket_smack *ssp = sk->sk_security;
3104 char *smack;
3105
3106 if (req->peer_secid != 0) {
3107 smack = smack_from_secid(req->peer_secid);
3108 strncpy(ssp->smk_packet, smack, SMK_MAXLEN);
3109 } else
3110 ssp->smk_packet[0] = '\0';
3111 }
3112
3113 /*
3114 * Key management security hooks
3115 *
3116 * Casey has not tested key support very heavily.
3117 * The permission check is most likely too restrictive.
3118 * If you care about keys please have a look.
3119 */
3120 #ifdef CONFIG_KEYS
3121
3122 /**
3123 * smack_key_alloc - Set the key security blob
3124 * @key: object
3125 * @cred: the credentials to use
3126 * @flags: unused
3127 *
3128 * No allocation required
3129 *
3130 * Returns 0
3131 */
3132 static int smack_key_alloc(struct key *key, const struct cred *cred,
3133 unsigned long flags)
3134 {
3135 key->security = smk_of_task(cred->security);
3136 return 0;
3137 }
3138
3139 /**
3140 * smack_key_free - Clear the key security blob
3141 * @key: the object
3142 *
3143 * Clear the blob pointer
3144 */
3145 static void smack_key_free(struct key *key)
3146 {
3147 key->security = NULL;
3148 }
3149
3150 /*
3151 * smack_key_permission - Smack access on a key
3152 * @key_ref: gets to the object
3153 * @cred: the credentials to use
3154 * @perm: unused
3155 *
3156 * Return 0 if the task has read and write to the object,
3157 * an error code otherwise
3158 */
3159 static int smack_key_permission(key_ref_t key_ref,
3160 const struct cred *cred, key_perm_t perm)
3161 {
3162 struct key *keyp;
3163 struct smk_audit_info ad;
3164 char *tsp = smk_of_task(cred->security);
3165
3166 keyp = key_ref_to_ptr(key_ref);
3167 if (keyp == NULL)
3168 return -EINVAL;
3169 /*
3170 * If the key hasn't been initialized give it access so that
3171 * it may do so.
3172 */
3173 if (keyp->security == NULL)
3174 return 0;
3175 /*
3176 * This should not occur
3177 */
3178 if (tsp == NULL)
3179 return -EACCES;
3180 #ifdef CONFIG_AUDIT
3181 smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_KEY);
3182 ad.a.u.key_struct.key = keyp->serial;
3183 ad.a.u.key_struct.key_desc = keyp->description;
3184 #endif
3185 return smk_access(tsp, keyp->security,
3186 MAY_READWRITE, &ad);
3187 }
3188 #endif /* CONFIG_KEYS */
3189
3190 /*
3191 * Smack Audit hooks
3192 *
3193 * Audit requires a unique representation of each Smack specific
3194 * rule. This unique representation is used to distinguish the
3195 * object to be audited from remaining kernel objects and also
3196 * works as a glue between the audit hooks.
3197 *
3198 * Since repository entries are added but never deleted, we'll use
3199 * the smack_known label address related to the given audit rule as
3200 * the needed unique representation. This also better fits the smack
3201 * model where nearly everything is a label.
3202 */
3203 #ifdef CONFIG_AUDIT
3204
3205 /**
3206 * smack_audit_rule_init - Initialize a smack audit rule
3207 * @field: audit rule fields given from user-space (audit.h)
3208 * @op: required testing operator (=, !=, >, <, ...)
3209 * @rulestr: smack label to be audited
3210 * @vrule: pointer to save our own audit rule representation
3211 *
3212 * Prepare to audit cases where (@field @op @rulestr) is true.
3213 * The label to be audited is created if necessay.
3214 */
3215 static int smack_audit_rule_init(u32 field, u32 op, char *rulestr, void **vrule)
3216 {
3217 char **rule = (char **)vrule;
3218 *rule = NULL;
3219
3220 if (field != AUDIT_SUBJ_USER && field != AUDIT_OBJ_USER)
3221 return -EINVAL;
3222
3223 if (op != Audit_equal && op != Audit_not_equal)
3224 return -EINVAL;
3225
3226 *rule = smk_import(rulestr, 0);
3227
3228 return 0;
3229 }
3230
3231 /**
3232 * smack_audit_rule_known - Distinguish Smack audit rules
3233 * @krule: rule of interest, in Audit kernel representation format
3234 *
3235 * This is used to filter Smack rules from remaining Audit ones.
3236 * If it's proved that this rule belongs to us, the
3237 * audit_rule_match hook will be called to do the final judgement.
3238 */
3239 static int smack_audit_rule_known(struct audit_krule *krule)
3240 {
3241 struct audit_field *f;
3242 int i;
3243
3244 for (i = 0; i < krule->field_count; i++) {
3245 f = &krule->fields[i];
3246
3247 if (f->type == AUDIT_SUBJ_USER || f->type == AUDIT_OBJ_USER)
3248 return 1;
3249 }
3250
3251 return 0;
3252 }
3253
3254 /**
3255 * smack_audit_rule_match - Audit given object ?
3256 * @secid: security id for identifying the object to test
3257 * @field: audit rule flags given from user-space
3258 * @op: required testing operator
3259 * @vrule: smack internal rule presentation
3260 * @actx: audit context associated with the check
3261 *
3262 * The core Audit hook. It's used to take the decision of
3263 * whether to audit or not to audit a given object.
3264 */
3265 static int smack_audit_rule_match(u32 secid, u32 field, u32 op, void *vrule,
3266 struct audit_context *actx)
3267 {
3268 char *smack;
3269 char *rule = vrule;
3270
3271 if (!rule) {
3272 audit_log(actx, GFP_KERNEL, AUDIT_SELINUX_ERR,
3273 "Smack: missing rule\n");
3274 return -ENOENT;
3275 }
3276
3277 if (field != AUDIT_SUBJ_USER && field != AUDIT_OBJ_USER)
3278 return 0;
3279
3280 smack = smack_from_secid(secid);
3281
3282 /*
3283 * No need to do string comparisons. If a match occurs,
3284 * both pointers will point to the same smack_known
3285 * label.
3286 */
3287 if (op == Audit_equal)
3288 return (rule == smack);
3289 if (op == Audit_not_equal)
3290 return (rule != smack);
3291
3292 return 0;
3293 }
3294
3295 /**
3296 * smack_audit_rule_free - free smack rule representation
3297 * @vrule: rule to be freed.
3298 *
3299 * No memory was allocated.
3300 */
3301 static void smack_audit_rule_free(void *vrule)
3302 {
3303 /* No-op */
3304 }
3305
3306 #endif /* CONFIG_AUDIT */
3307
3308 /**
3309 * smack_secid_to_secctx - return the smack label for a secid
3310 * @secid: incoming integer
3311 * @secdata: destination
3312 * @seclen: how long it is
3313 *
3314 * Exists for networking code.
3315 */
3316 static int smack_secid_to_secctx(u32 secid, char **secdata, u32 *seclen)
3317 {
3318 char *sp = smack_from_secid(secid);
3319
3320 if (secdata)
3321 *secdata = sp;
3322 *seclen = strlen(sp);
3323 return 0;
3324 }
3325
3326 /**
3327 * smack_secctx_to_secid - return the secid for a smack label
3328 * @secdata: smack label
3329 * @seclen: how long result is
3330 * @secid: outgoing integer
3331 *
3332 * Exists for audit and networking code.
3333 */
3334 static int smack_secctx_to_secid(const char *secdata, u32 seclen, u32 *secid)
3335 {
3336 *secid = smack_to_secid(secdata);
3337 return 0;
3338 }
3339
3340 /**
3341 * smack_release_secctx - don't do anything.
3342 * @secdata: unused
3343 * @seclen: unused
3344 *
3345 * Exists to make sure nothing gets done, and properly
3346 */
3347 static void smack_release_secctx(char *secdata, u32 seclen)
3348 {
3349 }
3350
3351 static int smack_inode_notifysecctx(struct inode *inode, void *ctx, u32 ctxlen)
3352 {
3353 return smack_inode_setsecurity(inode, XATTR_SMACK_SUFFIX, ctx, ctxlen, 0);
3354 }
3355
3356 static int smack_inode_setsecctx(struct dentry *dentry, void *ctx, u32 ctxlen)
3357 {
3358 return __vfs_setxattr_noperm(dentry, XATTR_NAME_SMACK, ctx, ctxlen, 0);
3359 }
3360
3361 static int smack_inode_getsecctx(struct inode *inode, void **ctx, u32 *ctxlen)
3362 {
3363 int len = 0;
3364 len = smack_inode_getsecurity(inode, XATTR_SMACK_SUFFIX, ctx, true);
3365
3366 if (len < 0)
3367 return len;
3368 *ctxlen = len;
3369 return 0;
3370 }
3371
3372 struct security_operations smack_ops = {
3373 .name = "smack",
3374
3375 .ptrace_access_check = smack_ptrace_access_check,
3376 .ptrace_traceme = smack_ptrace_traceme,
3377 .syslog = smack_syslog,
3378
3379 .sb_alloc_security = smack_sb_alloc_security,
3380 .sb_free_security = smack_sb_free_security,
3381 .sb_copy_data = smack_sb_copy_data,
3382 .sb_kern_mount = smack_sb_kern_mount,
3383 .sb_statfs = smack_sb_statfs,
3384 .sb_mount = smack_sb_mount,
3385 .sb_umount = smack_sb_umount,
3386
3387 .bprm_set_creds = smack_bprm_set_creds,
3388
3389 .inode_alloc_security = smack_inode_alloc_security,
3390 .inode_free_security = smack_inode_free_security,
3391 .inode_init_security = smack_inode_init_security,
3392 .inode_link = smack_inode_link,
3393 .inode_unlink = smack_inode_unlink,
3394 .inode_rmdir = smack_inode_rmdir,
3395 .inode_rename = smack_inode_rename,
3396 .inode_permission = smack_inode_permission,
3397 .inode_setattr = smack_inode_setattr,
3398 .inode_getattr = smack_inode_getattr,
3399 .inode_setxattr = smack_inode_setxattr,
3400 .inode_post_setxattr = smack_inode_post_setxattr,
3401 .inode_getxattr = smack_inode_getxattr,
3402 .inode_removexattr = smack_inode_removexattr,
3403 .inode_getsecurity = smack_inode_getsecurity,
3404 .inode_setsecurity = smack_inode_setsecurity,
3405 .inode_listsecurity = smack_inode_listsecurity,
3406 .inode_getsecid = smack_inode_getsecid,
3407
3408 .file_permission = smack_file_permission,
3409 .file_alloc_security = smack_file_alloc_security,
3410 .file_free_security = smack_file_free_security,
3411 .file_ioctl = smack_file_ioctl,
3412 .file_lock = smack_file_lock,
3413 .file_fcntl = smack_file_fcntl,
3414 .file_mmap = smack_file_mmap,
3415 .file_set_fowner = smack_file_set_fowner,
3416 .file_send_sigiotask = smack_file_send_sigiotask,
3417 .file_receive = smack_file_receive,
3418
3419 .cred_alloc_blank = smack_cred_alloc_blank,
3420 .cred_free = smack_cred_free,
3421 .cred_prepare = smack_cred_prepare,
3422 .cred_transfer = smack_cred_transfer,
3423 .kernel_act_as = smack_kernel_act_as,
3424 .kernel_create_files_as = smack_kernel_create_files_as,
3425 .task_setpgid = smack_task_setpgid,
3426 .task_getpgid = smack_task_getpgid,
3427 .task_getsid = smack_task_getsid,
3428 .task_getsecid = smack_task_getsecid,
3429 .task_setnice = smack_task_setnice,
3430 .task_setioprio = smack_task_setioprio,
3431 .task_getioprio = smack_task_getioprio,
3432 .task_setscheduler = smack_task_setscheduler,
3433 .task_getscheduler = smack_task_getscheduler,
3434 .task_movememory = smack_task_movememory,
3435 .task_kill = smack_task_kill,
3436 .task_wait = smack_task_wait,
3437 .task_to_inode = smack_task_to_inode,
3438
3439 .ipc_permission = smack_ipc_permission,
3440 .ipc_getsecid = smack_ipc_getsecid,
3441
3442 .msg_msg_alloc_security = smack_msg_msg_alloc_security,
3443 .msg_msg_free_security = smack_msg_msg_free_security,
3444
3445 .msg_queue_alloc_security = smack_msg_queue_alloc_security,
3446 .msg_queue_free_security = smack_msg_queue_free_security,
3447 .msg_queue_associate = smack_msg_queue_associate,
3448 .msg_queue_msgctl = smack_msg_queue_msgctl,
3449 .msg_queue_msgsnd = smack_msg_queue_msgsnd,
3450 .msg_queue_msgrcv = smack_msg_queue_msgrcv,
3451
3452 .shm_alloc_security = smack_shm_alloc_security,
3453 .shm_free_security = smack_shm_free_security,
3454 .shm_associate = smack_shm_associate,
3455 .shm_shmctl = smack_shm_shmctl,
3456 .shm_shmat = smack_shm_shmat,
3457
3458 .sem_alloc_security = smack_sem_alloc_security,
3459 .sem_free_security = smack_sem_free_security,
3460 .sem_associate = smack_sem_associate,
3461 .sem_semctl = smack_sem_semctl,
3462 .sem_semop = smack_sem_semop,
3463
3464 .d_instantiate = smack_d_instantiate,
3465
3466 .getprocattr = smack_getprocattr,
3467 .setprocattr = smack_setprocattr,
3468
3469 .unix_stream_connect = smack_unix_stream_connect,
3470 .unix_may_send = smack_unix_may_send,
3471
3472 .socket_post_create = smack_socket_post_create,
3473 .socket_connect = smack_socket_connect,
3474 .socket_sendmsg = smack_socket_sendmsg,
3475 .socket_sock_rcv_skb = smack_socket_sock_rcv_skb,
3476 .socket_getpeersec_stream = smack_socket_getpeersec_stream,
3477 .socket_getpeersec_dgram = smack_socket_getpeersec_dgram,
3478 .sk_alloc_security = smack_sk_alloc_security,
3479 .sk_free_security = smack_sk_free_security,
3480 .sock_graft = smack_sock_graft,
3481 .inet_conn_request = smack_inet_conn_request,
3482 .inet_csk_clone = smack_inet_csk_clone,
3483
3484 /* key management security hooks */
3485 #ifdef CONFIG_KEYS
3486 .key_alloc = smack_key_alloc,
3487 .key_free = smack_key_free,
3488 .key_permission = smack_key_permission,
3489 #endif /* CONFIG_KEYS */
3490
3491 /* Audit hooks */
3492 #ifdef CONFIG_AUDIT
3493 .audit_rule_init = smack_audit_rule_init,
3494 .audit_rule_known = smack_audit_rule_known,
3495 .audit_rule_match = smack_audit_rule_match,
3496 .audit_rule_free = smack_audit_rule_free,
3497 #endif /* CONFIG_AUDIT */
3498
3499 .secid_to_secctx = smack_secid_to_secctx,
3500 .secctx_to_secid = smack_secctx_to_secid,
3501 .release_secctx = smack_release_secctx,
3502 .inode_notifysecctx = smack_inode_notifysecctx,
3503 .inode_setsecctx = smack_inode_setsecctx,
3504 .inode_getsecctx = smack_inode_getsecctx,
3505 };
3506
3507
3508 static __init void init_smack_know_list(void)
3509 {
3510 list_add(&smack_known_huh.list, &smack_known_list);
3511 list_add(&smack_known_hat.list, &smack_known_list);
3512 list_add(&smack_known_star.list, &smack_known_list);
3513 list_add(&smack_known_floor.list, &smack_known_list);
3514 list_add(&smack_known_invalid.list, &smack_known_list);
3515 list_add(&smack_known_web.list, &smack_known_list);
3516 }
3517
3518 /**
3519 * smack_init - initialize the smack system
3520 *
3521 * Returns 0
3522 */
3523 static __init int smack_init(void)
3524 {
3525 struct cred *cred;
3526 struct task_smack *tsp;
3527
3528 if (!security_module_enable(&smack_ops))
3529 return 0;
3530
3531 tsp = new_task_smack(smack_known_floor.smk_known,
3532 smack_known_floor.smk_known, GFP_KERNEL);
3533 if (tsp == NULL)
3534 return -ENOMEM;
3535
3536 printk(KERN_INFO "Smack: Initializing.\n");
3537
3538 /*
3539 * Set the security state for the initial task.
3540 */
3541 cred = (struct cred *) current->cred;
3542 cred->security = tsp;
3543
3544 /* initialize the smack_know_list */
3545 init_smack_know_list();
3546 /*
3547 * Initialize locks
3548 */
3549 spin_lock_init(&smack_known_huh.smk_cipsolock);
3550 spin_lock_init(&smack_known_hat.smk_cipsolock);
3551 spin_lock_init(&smack_known_star.smk_cipsolock);
3552 spin_lock_init(&smack_known_floor.smk_cipsolock);
3553 spin_lock_init(&smack_known_invalid.smk_cipsolock);
3554
3555 /*
3556 * Register with LSM
3557 */
3558 if (register_security(&smack_ops))
3559 panic("smack: Unable to register with kernel.\n");
3560
3561 return 0;
3562 }
3563
3564 /*
3565 * Smack requires early initialization in order to label
3566 * all processes and objects when they are created.
3567 */
3568 security_initcall(smack_init);