xref: /linux/security/smack/smack_lsm.c (revision 4705b2e8047221142af2ed5e37f54ac4c7f80a7d)
1 /*
2  *  Simplified MAC Kernel (smack) security module
3  *
4  *  This file contains the smack hook function implementations.
5  *
6  *  Author:
7  *	Casey Schaufler <casey@schaufler-ca.com>
8  *
9  *  Copyright (C) 2007 Casey Schaufler <casey@schaufler-ca.com>
10  *  Copyright (C) 2009 Hewlett-Packard Development Company, L.P.
11  *                Paul Moore <paul.moore@hp.com>
12  *
13  *	This program is free software; you can redistribute it and/or modify
14  *	it under the terms of the GNU General Public License version 2,
15  *      as published by the Free Software Foundation.
16  */
17 
18 #include <linux/xattr.h>
19 #include <linux/pagemap.h>
20 #include <linux/mount.h>
21 #include <linux/stat.h>
22 #include <linux/kd.h>
23 #include <asm/ioctls.h>
24 #include <linux/ip.h>
25 #include <linux/tcp.h>
26 #include <linux/udp.h>
27 #include <linux/slab.h>
28 #include <linux/mutex.h>
29 #include <linux/pipe_fs_i.h>
30 #include <net/netlabel.h>
31 #include <net/cipso_ipv4.h>
32 #include <linux/audit.h>
33 #include <linux/magic.h>
34 #include "smack.h"
35 
36 #define task_security(task)	(task_cred_xxx((task), security))
37 
38 /**
39  * smk_fetch - Fetch the smack label from a file.
40  * @ip: a pointer to the inode
41  * @dp: a pointer to the dentry
42  *
43  * Returns a pointer to the master list entry for the Smack label
44  * or NULL if there was no label to fetch.
45  */
46 static char *smk_fetch(struct inode *ip, struct dentry *dp)
47 {
48 	int rc;
49 	char in[SMK_LABELLEN];
50 
51 	if (ip->i_op->getxattr == NULL)
52 		return NULL;
53 
54 	rc = ip->i_op->getxattr(dp, XATTR_NAME_SMACK, in, SMK_LABELLEN);
55 	if (rc < 0)
56 		return NULL;
57 
58 	return smk_import(in, rc);
59 }
60 
61 /**
62  * new_inode_smack - allocate an inode security blob
63  * @smack: a pointer to the Smack label to use in the blob
64  *
65  * Returns the new blob or NULL if there's no memory available
66  */
67 struct inode_smack *new_inode_smack(char *smack)
68 {
69 	struct inode_smack *isp;
70 
71 	isp = kzalloc(sizeof(struct inode_smack), GFP_KERNEL);
72 	if (isp == NULL)
73 		return NULL;
74 
75 	isp->smk_inode = smack;
76 	isp->smk_flags = 0;
77 	mutex_init(&isp->smk_lock);
78 
79 	return isp;
80 }
81 
82 /*
83  * LSM hooks.
84  * We he, that is fun!
85  */
86 
87 /**
88  * smack_ptrace_access_check - Smack approval on PTRACE_ATTACH
89  * @ctp: child task pointer
90  * @mode: ptrace attachment mode
91  *
92  * Returns 0 if access is OK, an error code otherwise
93  *
94  * Do the capability checks, and require read and write.
95  */
96 static int smack_ptrace_access_check(struct task_struct *ctp, unsigned int mode)
97 {
98 	int rc;
99 	struct smk_audit_info ad;
100 	char *sp, *tsp;
101 
102 	rc = cap_ptrace_access_check(ctp, mode);
103 	if (rc != 0)
104 		return rc;
105 
106 	sp = current_security();
107 	tsp = task_security(ctp);
108 	smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_TASK);
109 	smk_ad_setfield_u_tsk(&ad, ctp);
110 
111 	/* we won't log here, because rc can be overriden */
112 	rc = smk_access(sp, tsp, MAY_READWRITE, NULL);
113 	if (rc != 0 && capable(CAP_MAC_OVERRIDE))
114 		rc = 0;
115 
116 	smack_log(sp, tsp, MAY_READWRITE, rc, &ad);
117 	return rc;
118 }
119 
120 /**
121  * smack_ptrace_traceme - Smack approval on PTRACE_TRACEME
122  * @ptp: parent task pointer
123  *
124  * Returns 0 if access is OK, an error code otherwise
125  *
126  * Do the capability checks, and require read and write.
127  */
128 static int smack_ptrace_traceme(struct task_struct *ptp)
129 {
130 	int rc;
131 	struct smk_audit_info ad;
132 	char *sp, *tsp;
133 
134 	rc = cap_ptrace_traceme(ptp);
135 	if (rc != 0)
136 		return rc;
137 
138 	smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_TASK);
139 	smk_ad_setfield_u_tsk(&ad, ptp);
140 
141 	sp = current_security();
142 	tsp = task_security(ptp);
143 	/* we won't log here, because rc can be overriden */
144 	rc = smk_access(tsp, sp, MAY_READWRITE, NULL);
145 	if (rc != 0 && has_capability(ptp, CAP_MAC_OVERRIDE))
146 		rc = 0;
147 
148 	smack_log(tsp, sp, MAY_READWRITE, rc, &ad);
149 	return rc;
150 }
151 
152 /**
153  * smack_syslog - Smack approval on syslog
154  * @type: message type
155  *
156  * Require that the task has the floor label
157  *
158  * Returns 0 on success, error code otherwise.
159  */
160 static int smack_syslog(int type, bool from_file)
161 {
162 	int rc;
163 	char *sp = current_security();
164 
165 	rc = cap_syslog(type, from_file);
166 	if (rc != 0)
167 		return rc;
168 
169 	if (capable(CAP_MAC_OVERRIDE))
170 		return 0;
171 
172 	 if (sp != smack_known_floor.smk_known)
173 		rc = -EACCES;
174 
175 	return rc;
176 }
177 
178 
179 /*
180  * Superblock Hooks.
181  */
182 
183 /**
184  * smack_sb_alloc_security - allocate a superblock blob
185  * @sb: the superblock getting the blob
186  *
187  * Returns 0 on success or -ENOMEM on error.
188  */
189 static int smack_sb_alloc_security(struct super_block *sb)
190 {
191 	struct superblock_smack *sbsp;
192 
193 	sbsp = kzalloc(sizeof(struct superblock_smack), GFP_KERNEL);
194 
195 	if (sbsp == NULL)
196 		return -ENOMEM;
197 
198 	sbsp->smk_root = smack_known_floor.smk_known;
199 	sbsp->smk_default = smack_known_floor.smk_known;
200 	sbsp->smk_floor = smack_known_floor.smk_known;
201 	sbsp->smk_hat = smack_known_hat.smk_known;
202 	sbsp->smk_initialized = 0;
203 	spin_lock_init(&sbsp->smk_sblock);
204 
205 	sb->s_security = sbsp;
206 
207 	return 0;
208 }
209 
210 /**
211  * smack_sb_free_security - free a superblock blob
212  * @sb: the superblock getting the blob
213  *
214  */
215 static void smack_sb_free_security(struct super_block *sb)
216 {
217 	kfree(sb->s_security);
218 	sb->s_security = NULL;
219 }
220 
221 /**
222  * smack_sb_copy_data - copy mount options data for processing
223  * @orig: where to start
224  * @smackopts: mount options string
225  *
226  * Returns 0 on success or -ENOMEM on error.
227  *
228  * Copy the Smack specific mount options out of the mount
229  * options list.
230  */
231 static int smack_sb_copy_data(char *orig, char *smackopts)
232 {
233 	char *cp, *commap, *otheropts, *dp;
234 
235 	otheropts = (char *)get_zeroed_page(GFP_KERNEL);
236 	if (otheropts == NULL)
237 		return -ENOMEM;
238 
239 	for (cp = orig, commap = orig; commap != NULL; cp = commap + 1) {
240 		if (strstr(cp, SMK_FSDEFAULT) == cp)
241 			dp = smackopts;
242 		else if (strstr(cp, SMK_FSFLOOR) == cp)
243 			dp = smackopts;
244 		else if (strstr(cp, SMK_FSHAT) == cp)
245 			dp = smackopts;
246 		else if (strstr(cp, SMK_FSROOT) == cp)
247 			dp = smackopts;
248 		else
249 			dp = otheropts;
250 
251 		commap = strchr(cp, ',');
252 		if (commap != NULL)
253 			*commap = '\0';
254 
255 		if (*dp != '\0')
256 			strcat(dp, ",");
257 		strcat(dp, cp);
258 	}
259 
260 	strcpy(orig, otheropts);
261 	free_page((unsigned long)otheropts);
262 
263 	return 0;
264 }
265 
266 /**
267  * smack_sb_kern_mount - Smack specific mount processing
268  * @sb: the file system superblock
269  * @flags: the mount flags
270  * @data: the smack mount options
271  *
272  * Returns 0 on success, an error code on failure
273  */
274 static int smack_sb_kern_mount(struct super_block *sb, int flags, void *data)
275 {
276 	struct dentry *root = sb->s_root;
277 	struct inode *inode = root->d_inode;
278 	struct superblock_smack *sp = sb->s_security;
279 	struct inode_smack *isp;
280 	char *op;
281 	char *commap;
282 	char *nsp;
283 
284 	spin_lock(&sp->smk_sblock);
285 	if (sp->smk_initialized != 0) {
286 		spin_unlock(&sp->smk_sblock);
287 		return 0;
288 	}
289 	sp->smk_initialized = 1;
290 	spin_unlock(&sp->smk_sblock);
291 
292 	for (op = data; op != NULL; op = commap) {
293 		commap = strchr(op, ',');
294 		if (commap != NULL)
295 			*commap++ = '\0';
296 
297 		if (strncmp(op, SMK_FSHAT, strlen(SMK_FSHAT)) == 0) {
298 			op += strlen(SMK_FSHAT);
299 			nsp = smk_import(op, 0);
300 			if (nsp != NULL)
301 				sp->smk_hat = nsp;
302 		} else if (strncmp(op, SMK_FSFLOOR, strlen(SMK_FSFLOOR)) == 0) {
303 			op += strlen(SMK_FSFLOOR);
304 			nsp = smk_import(op, 0);
305 			if (nsp != NULL)
306 				sp->smk_floor = nsp;
307 		} else if (strncmp(op, SMK_FSDEFAULT,
308 				   strlen(SMK_FSDEFAULT)) == 0) {
309 			op += strlen(SMK_FSDEFAULT);
310 			nsp = smk_import(op, 0);
311 			if (nsp != NULL)
312 				sp->smk_default = nsp;
313 		} else if (strncmp(op, SMK_FSROOT, strlen(SMK_FSROOT)) == 0) {
314 			op += strlen(SMK_FSROOT);
315 			nsp = smk_import(op, 0);
316 			if (nsp != NULL)
317 				sp->smk_root = nsp;
318 		}
319 	}
320 
321 	/*
322 	 * Initialize the root inode.
323 	 */
324 	isp = inode->i_security;
325 	if (isp == NULL)
326 		inode->i_security = new_inode_smack(sp->smk_root);
327 	else
328 		isp->smk_inode = sp->smk_root;
329 
330 	return 0;
331 }
332 
333 /**
334  * smack_sb_statfs - Smack check on statfs
335  * @dentry: identifies the file system in question
336  *
337  * Returns 0 if current can read the floor of the filesystem,
338  * and error code otherwise
339  */
340 static int smack_sb_statfs(struct dentry *dentry)
341 {
342 	struct superblock_smack *sbp = dentry->d_sb->s_security;
343 	int rc;
344 	struct smk_audit_info ad;
345 
346 	smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_FS);
347 	smk_ad_setfield_u_fs_path_dentry(&ad, dentry);
348 
349 	rc = smk_curacc(sbp->smk_floor, MAY_READ, &ad);
350 	return rc;
351 }
352 
353 /**
354  * smack_sb_mount - Smack check for mounting
355  * @dev_name: unused
356  * @path: mount point
357  * @type: unused
358  * @flags: unused
359  * @data: unused
360  *
361  * Returns 0 if current can write the floor of the filesystem
362  * being mounted on, an error code otherwise.
363  */
364 static int smack_sb_mount(char *dev_name, struct path *path,
365 			  char *type, unsigned long flags, void *data)
366 {
367 	struct superblock_smack *sbp = path->mnt->mnt_sb->s_security;
368 	struct smk_audit_info ad;
369 
370 	smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_FS);
371 	smk_ad_setfield_u_fs_path(&ad, *path);
372 
373 	return smk_curacc(sbp->smk_floor, MAY_WRITE, &ad);
374 }
375 
376 /**
377  * smack_sb_umount - Smack check for unmounting
378  * @mnt: file system to unmount
379  * @flags: unused
380  *
381  * Returns 0 if current can write the floor of the filesystem
382  * being unmounted, an error code otherwise.
383  */
384 static int smack_sb_umount(struct vfsmount *mnt, int flags)
385 {
386 	struct superblock_smack *sbp;
387 	struct smk_audit_info ad;
388 
389 	smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_FS);
390 	smk_ad_setfield_u_fs_path_dentry(&ad, mnt->mnt_root);
391 	smk_ad_setfield_u_fs_path_mnt(&ad, mnt);
392 
393 	sbp = mnt->mnt_sb->s_security;
394 	return smk_curacc(sbp->smk_floor, MAY_WRITE, &ad);
395 }
396 
397 /*
398  * Inode hooks
399  */
400 
401 /**
402  * smack_inode_alloc_security - allocate an inode blob
403  * @inode: the inode in need of a blob
404  *
405  * Returns 0 if it gets a blob, -ENOMEM otherwise
406  */
407 static int smack_inode_alloc_security(struct inode *inode)
408 {
409 	inode->i_security = new_inode_smack(current_security());
410 	if (inode->i_security == NULL)
411 		return -ENOMEM;
412 	return 0;
413 }
414 
415 /**
416  * smack_inode_free_security - free an inode blob
417  * @inode: the inode with a blob
418  *
419  * Clears the blob pointer in inode
420  */
421 static void smack_inode_free_security(struct inode *inode)
422 {
423 	kfree(inode->i_security);
424 	inode->i_security = NULL;
425 }
426 
427 /**
428  * smack_inode_init_security - copy out the smack from an inode
429  * @inode: the inode
430  * @dir: unused
431  * @name: where to put the attribute name
432  * @value: where to put the attribute value
433  * @len: where to put the length of the attribute
434  *
435  * Returns 0 if it all works out, -ENOMEM if there's no memory
436  */
437 static int smack_inode_init_security(struct inode *inode, struct inode *dir,
438 				     char **name, void **value, size_t *len)
439 {
440 	char *isp = smk_of_inode(inode);
441 
442 	if (name) {
443 		*name = kstrdup(XATTR_SMACK_SUFFIX, GFP_KERNEL);
444 		if (*name == NULL)
445 			return -ENOMEM;
446 	}
447 
448 	if (value) {
449 		*value = kstrdup(isp, GFP_KERNEL);
450 		if (*value == NULL)
451 			return -ENOMEM;
452 	}
453 
454 	if (len)
455 		*len = strlen(isp) + 1;
456 
457 	return 0;
458 }
459 
460 /**
461  * smack_inode_link - Smack check on link
462  * @old_dentry: the existing object
463  * @dir: unused
464  * @new_dentry: the new object
465  *
466  * Returns 0 if access is permitted, an error code otherwise
467  */
468 static int smack_inode_link(struct dentry *old_dentry, struct inode *dir,
469 			    struct dentry *new_dentry)
470 {
471 	char *isp;
472 	struct smk_audit_info ad;
473 	int rc;
474 
475 	smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_FS);
476 	smk_ad_setfield_u_fs_path_dentry(&ad, old_dentry);
477 
478 	isp = smk_of_inode(old_dentry->d_inode);
479 	rc = smk_curacc(isp, MAY_WRITE, &ad);
480 
481 	if (rc == 0 && new_dentry->d_inode != NULL) {
482 		isp = smk_of_inode(new_dentry->d_inode);
483 		smk_ad_setfield_u_fs_path_dentry(&ad, new_dentry);
484 		rc = smk_curacc(isp, MAY_WRITE, &ad);
485 	}
486 
487 	return rc;
488 }
489 
490 /**
491  * smack_inode_unlink - Smack check on inode deletion
492  * @dir: containing directory object
493  * @dentry: file to unlink
494  *
495  * Returns 0 if current can write the containing directory
496  * and the object, error code otherwise
497  */
498 static int smack_inode_unlink(struct inode *dir, struct dentry *dentry)
499 {
500 	struct inode *ip = dentry->d_inode;
501 	struct smk_audit_info ad;
502 	int rc;
503 
504 	smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_FS);
505 	smk_ad_setfield_u_fs_path_dentry(&ad, dentry);
506 
507 	/*
508 	 * You need write access to the thing you're unlinking
509 	 */
510 	rc = smk_curacc(smk_of_inode(ip), MAY_WRITE, &ad);
511 	if (rc == 0) {
512 		/*
513 		 * You also need write access to the containing directory
514 		 */
515 		smk_ad_setfield_u_fs_path_dentry(&ad, NULL);
516 		smk_ad_setfield_u_fs_inode(&ad, dir);
517 		rc = smk_curacc(smk_of_inode(dir), MAY_WRITE, &ad);
518 	}
519 	return rc;
520 }
521 
522 /**
523  * smack_inode_rmdir - Smack check on directory deletion
524  * @dir: containing directory object
525  * @dentry: directory to unlink
526  *
527  * Returns 0 if current can write the containing directory
528  * and the directory, error code otherwise
529  */
530 static int smack_inode_rmdir(struct inode *dir, struct dentry *dentry)
531 {
532 	struct smk_audit_info ad;
533 	int rc;
534 
535 	smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_FS);
536 	smk_ad_setfield_u_fs_path_dentry(&ad, dentry);
537 
538 	/*
539 	 * You need write access to the thing you're removing
540 	 */
541 	rc = smk_curacc(smk_of_inode(dentry->d_inode), MAY_WRITE, &ad);
542 	if (rc == 0) {
543 		/*
544 		 * You also need write access to the containing directory
545 		 */
546 		smk_ad_setfield_u_fs_path_dentry(&ad, NULL);
547 		smk_ad_setfield_u_fs_inode(&ad, dir);
548 		rc = smk_curacc(smk_of_inode(dir), MAY_WRITE, &ad);
549 	}
550 
551 	return rc;
552 }
553 
554 /**
555  * smack_inode_rename - Smack check on rename
556  * @old_inode: the old directory
557  * @old_dentry: unused
558  * @new_inode: the new directory
559  * @new_dentry: unused
560  *
561  * Read and write access is required on both the old and
562  * new directories.
563  *
564  * Returns 0 if access is permitted, an error code otherwise
565  */
566 static int smack_inode_rename(struct inode *old_inode,
567 			      struct dentry *old_dentry,
568 			      struct inode *new_inode,
569 			      struct dentry *new_dentry)
570 {
571 	int rc;
572 	char *isp;
573 	struct smk_audit_info ad;
574 
575 	smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_FS);
576 	smk_ad_setfield_u_fs_path_dentry(&ad, old_dentry);
577 
578 	isp = smk_of_inode(old_dentry->d_inode);
579 	rc = smk_curacc(isp, MAY_READWRITE, &ad);
580 
581 	if (rc == 0 && new_dentry->d_inode != NULL) {
582 		isp = smk_of_inode(new_dentry->d_inode);
583 		smk_ad_setfield_u_fs_path_dentry(&ad, new_dentry);
584 		rc = smk_curacc(isp, MAY_READWRITE, &ad);
585 	}
586 	return rc;
587 }
588 
589 /**
590  * smack_inode_permission - Smack version of permission()
591  * @inode: the inode in question
592  * @mask: the access requested
593  *
594  * This is the important Smack hook.
595  *
596  * Returns 0 if access is permitted, -EACCES otherwise
597  */
598 static int smack_inode_permission(struct inode *inode, int mask)
599 {
600 	struct smk_audit_info ad;
601 	/*
602 	 * No permission to check. Existence test. Yup, it's there.
603 	 */
604 	if (mask == 0)
605 		return 0;
606 	smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_FS);
607 	smk_ad_setfield_u_fs_inode(&ad, inode);
608 	return smk_curacc(smk_of_inode(inode), mask, &ad);
609 }
610 
611 /**
612  * smack_inode_setattr - Smack check for setting attributes
613  * @dentry: the object
614  * @iattr: for the force flag
615  *
616  * Returns 0 if access is permitted, an error code otherwise
617  */
618 static int smack_inode_setattr(struct dentry *dentry, struct iattr *iattr)
619 {
620 	struct smk_audit_info ad;
621 	/*
622 	 * Need to allow for clearing the setuid bit.
623 	 */
624 	if (iattr->ia_valid & ATTR_FORCE)
625 		return 0;
626 	smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_FS);
627 	smk_ad_setfield_u_fs_path_dentry(&ad, dentry);
628 
629 	return smk_curacc(smk_of_inode(dentry->d_inode), MAY_WRITE, &ad);
630 }
631 
632 /**
633  * smack_inode_getattr - Smack check for getting attributes
634  * @mnt: unused
635  * @dentry: the object
636  *
637  * Returns 0 if access is permitted, an error code otherwise
638  */
639 static int smack_inode_getattr(struct vfsmount *mnt, struct dentry *dentry)
640 {
641 	struct smk_audit_info ad;
642 
643 	smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_FS);
644 	smk_ad_setfield_u_fs_path_dentry(&ad, dentry);
645 	smk_ad_setfield_u_fs_path_mnt(&ad, mnt);
646 	return smk_curacc(smk_of_inode(dentry->d_inode), MAY_READ, &ad);
647 }
648 
649 /**
650  * smack_inode_setxattr - Smack check for setting xattrs
651  * @dentry: the object
652  * @name: name of the attribute
653  * @value: unused
654  * @size: unused
655  * @flags: unused
656  *
657  * This protects the Smack attribute explicitly.
658  *
659  * Returns 0 if access is permitted, an error code otherwise
660  */
661 static int smack_inode_setxattr(struct dentry *dentry, const char *name,
662 				const void *value, size_t size, int flags)
663 {
664 	struct smk_audit_info ad;
665 	int rc = 0;
666 
667 	if (strcmp(name, XATTR_NAME_SMACK) == 0 ||
668 	    strcmp(name, XATTR_NAME_SMACKIPIN) == 0 ||
669 	    strcmp(name, XATTR_NAME_SMACKIPOUT) == 0) {
670 		if (!capable(CAP_MAC_ADMIN))
671 			rc = -EPERM;
672 		/*
673 		 * check label validity here so import wont fail on
674 		 * post_setxattr
675 		 */
676 		if (size == 0 || size >= SMK_LABELLEN ||
677 		    smk_import(value, size) == NULL)
678 			rc = -EINVAL;
679 	} else
680 		rc = cap_inode_setxattr(dentry, name, value, size, flags);
681 
682 	smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_FS);
683 	smk_ad_setfield_u_fs_path_dentry(&ad, dentry);
684 
685 	if (rc == 0)
686 		rc = smk_curacc(smk_of_inode(dentry->d_inode), MAY_WRITE, &ad);
687 
688 	return rc;
689 }
690 
691 /**
692  * smack_inode_post_setxattr - Apply the Smack update approved above
693  * @dentry: object
694  * @name: attribute name
695  * @value: attribute value
696  * @size: attribute size
697  * @flags: unused
698  *
699  * Set the pointer in the inode blob to the entry found
700  * in the master label list.
701  */
702 static void smack_inode_post_setxattr(struct dentry *dentry, const char *name,
703 				      const void *value, size_t size, int flags)
704 {
705 	struct inode_smack *isp;
706 	char *nsp;
707 
708 	/*
709 	 * Not SMACK
710 	 */
711 	if (strcmp(name, XATTR_NAME_SMACK))
712 		return;
713 
714 	isp = dentry->d_inode->i_security;
715 
716 	/*
717 	 * No locking is done here. This is a pointer
718 	 * assignment.
719 	 */
720 	nsp = smk_import(value, size);
721 	if (nsp != NULL)
722 		isp->smk_inode = nsp;
723 	else
724 		isp->smk_inode = smack_known_invalid.smk_known;
725 
726 	return;
727 }
728 
729 /*
730  * smack_inode_getxattr - Smack check on getxattr
731  * @dentry: the object
732  * @name: unused
733  *
734  * Returns 0 if access is permitted, an error code otherwise
735  */
736 static int smack_inode_getxattr(struct dentry *dentry, const char *name)
737 {
738 	struct smk_audit_info ad;
739 
740 	smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_FS);
741 	smk_ad_setfield_u_fs_path_dentry(&ad, dentry);
742 
743 	return smk_curacc(smk_of_inode(dentry->d_inode), MAY_READ, &ad);
744 }
745 
746 /*
747  * smack_inode_removexattr - Smack check on removexattr
748  * @dentry: the object
749  * @name: name of the attribute
750  *
751  * Removing the Smack attribute requires CAP_MAC_ADMIN
752  *
753  * Returns 0 if access is permitted, an error code otherwise
754  */
755 static int smack_inode_removexattr(struct dentry *dentry, const char *name)
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 		if (!capable(CAP_MAC_ADMIN))
764 			rc = -EPERM;
765 	} else
766 		rc = cap_inode_removexattr(dentry, name);
767 
768 	smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_FS);
769 	smk_ad_setfield_u_fs_path_dentry(&ad, dentry);
770 	if (rc == 0)
771 		rc = smk_curacc(smk_of_inode(dentry->d_inode), MAY_WRITE, &ad);
772 
773 	return rc;
774 }
775 
776 /**
777  * smack_inode_getsecurity - get smack xattrs
778  * @inode: the object
779  * @name: attribute name
780  * @buffer: where to put the result
781  * @alloc: unused
782  *
783  * Returns the size of the attribute or an error code
784  */
785 static int smack_inode_getsecurity(const struct inode *inode,
786 				   const char *name, void **buffer,
787 				   bool alloc)
788 {
789 	struct socket_smack *ssp;
790 	struct socket *sock;
791 	struct super_block *sbp;
792 	struct inode *ip = (struct inode *)inode;
793 	char *isp;
794 	int ilen;
795 	int rc = 0;
796 
797 	if (strcmp(name, XATTR_SMACK_SUFFIX) == 0) {
798 		isp = smk_of_inode(inode);
799 		ilen = strlen(isp) + 1;
800 		*buffer = isp;
801 		return ilen;
802 	}
803 
804 	/*
805 	 * The rest of the Smack xattrs are only on sockets.
806 	 */
807 	sbp = ip->i_sb;
808 	if (sbp->s_magic != SOCKFS_MAGIC)
809 		return -EOPNOTSUPP;
810 
811 	sock = SOCKET_I(ip);
812 	if (sock == NULL || sock->sk == NULL)
813 		return -EOPNOTSUPP;
814 
815 	ssp = sock->sk->sk_security;
816 
817 	if (strcmp(name, XATTR_SMACK_IPIN) == 0)
818 		isp = ssp->smk_in;
819 	else if (strcmp(name, XATTR_SMACK_IPOUT) == 0)
820 		isp = ssp->smk_out;
821 	else
822 		return -EOPNOTSUPP;
823 
824 	ilen = strlen(isp) + 1;
825 	if (rc == 0) {
826 		*buffer = isp;
827 		rc = ilen;
828 	}
829 
830 	return rc;
831 }
832 
833 
834 /**
835  * smack_inode_listsecurity - list the Smack attributes
836  * @inode: the object
837  * @buffer: where they go
838  * @buffer_size: size of buffer
839  *
840  * Returns 0 on success, -EINVAL otherwise
841  */
842 static int smack_inode_listsecurity(struct inode *inode, char *buffer,
843 				    size_t buffer_size)
844 {
845 	int len = strlen(XATTR_NAME_SMACK);
846 
847 	if (buffer != NULL && len <= buffer_size) {
848 		memcpy(buffer, XATTR_NAME_SMACK, len);
849 		return len;
850 	}
851 	return -EINVAL;
852 }
853 
854 /**
855  * smack_inode_getsecid - Extract inode's security id
856  * @inode: inode to extract the info from
857  * @secid: where result will be saved
858  */
859 static void smack_inode_getsecid(const struct inode *inode, u32 *secid)
860 {
861 	struct inode_smack *isp = inode->i_security;
862 
863 	*secid = smack_to_secid(isp->smk_inode);
864 }
865 
866 /*
867  * File Hooks
868  */
869 
870 /**
871  * smack_file_permission - Smack check on file operations
872  * @file: unused
873  * @mask: unused
874  *
875  * Returns 0
876  *
877  * Should access checks be done on each read or write?
878  * UNICOS and SELinux say yes.
879  * Trusted Solaris, Trusted Irix, and just about everyone else says no.
880  *
881  * I'll say no for now. Smack does not do the frequent
882  * label changing that SELinux does.
883  */
884 static int smack_file_permission(struct file *file, int mask)
885 {
886 	return 0;
887 }
888 
889 /**
890  * smack_file_alloc_security - assign a file security blob
891  * @file: the object
892  *
893  * The security blob for a file is a pointer to the master
894  * label list, so no allocation is done.
895  *
896  * Returns 0
897  */
898 static int smack_file_alloc_security(struct file *file)
899 {
900 	file->f_security = current_security();
901 	return 0;
902 }
903 
904 /**
905  * smack_file_free_security - clear a file security blob
906  * @file: the object
907  *
908  * The security blob for a file is a pointer to the master
909  * label list, so no memory is freed.
910  */
911 static void smack_file_free_security(struct file *file)
912 {
913 	file->f_security = NULL;
914 }
915 
916 /**
917  * smack_file_ioctl - Smack check on ioctls
918  * @file: the object
919  * @cmd: what to do
920  * @arg: unused
921  *
922  * Relies heavily on the correct use of the ioctl command conventions.
923  *
924  * Returns 0 if allowed, error code otherwise
925  */
926 static int smack_file_ioctl(struct file *file, unsigned int cmd,
927 			    unsigned long arg)
928 {
929 	int rc = 0;
930 	struct smk_audit_info ad;
931 
932 	smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_FS);
933 	smk_ad_setfield_u_fs_path(&ad, file->f_path);
934 
935 	if (_IOC_DIR(cmd) & _IOC_WRITE)
936 		rc = smk_curacc(file->f_security, MAY_WRITE, &ad);
937 
938 	if (rc == 0 && (_IOC_DIR(cmd) & _IOC_READ))
939 		rc = smk_curacc(file->f_security, MAY_READ, &ad);
940 
941 	return rc;
942 }
943 
944 /**
945  * smack_file_lock - Smack check on file locking
946  * @file: the object
947  * @cmd: unused
948  *
949  * Returns 0 if current has write access, error code otherwise
950  */
951 static int smack_file_lock(struct file *file, unsigned int cmd)
952 {
953 	struct smk_audit_info ad;
954 
955 	smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_FS);
956 	smk_ad_setfield_u_fs_path_dentry(&ad, file->f_path.dentry);
957 	return smk_curacc(file->f_security, MAY_WRITE, &ad);
958 }
959 
960 /**
961  * smack_file_fcntl - Smack check on fcntl
962  * @file: the object
963  * @cmd: what action to check
964  * @arg: unused
965  *
966  * Returns 0 if current has access, error code otherwise
967  */
968 static int smack_file_fcntl(struct file *file, unsigned int cmd,
969 			    unsigned long arg)
970 {
971 	struct smk_audit_info ad;
972 	int rc;
973 
974 	smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_FS);
975 	smk_ad_setfield_u_fs_path(&ad, file->f_path);
976 
977 	switch (cmd) {
978 	case F_DUPFD:
979 	case F_GETFD:
980 	case F_GETFL:
981 	case F_GETLK:
982 	case F_GETOWN:
983 	case F_GETSIG:
984 		rc = smk_curacc(file->f_security, MAY_READ, &ad);
985 		break;
986 	case F_SETFD:
987 	case F_SETFL:
988 	case F_SETLK:
989 	case F_SETLKW:
990 	case F_SETOWN:
991 	case F_SETSIG:
992 		rc = smk_curacc(file->f_security, MAY_WRITE, &ad);
993 		break;
994 	default:
995 		rc = smk_curacc(file->f_security, MAY_READWRITE, &ad);
996 	}
997 
998 	return rc;
999 }
1000 
1001 /**
1002  * smack_file_set_fowner - set the file security blob value
1003  * @file: object in question
1004  *
1005  * Returns 0
1006  * Further research may be required on this one.
1007  */
1008 static int smack_file_set_fowner(struct file *file)
1009 {
1010 	file->f_security = current_security();
1011 	return 0;
1012 }
1013 
1014 /**
1015  * smack_file_send_sigiotask - Smack on sigio
1016  * @tsk: The target task
1017  * @fown: the object the signal come from
1018  * @signum: unused
1019  *
1020  * Allow a privileged task to get signals even if it shouldn't
1021  *
1022  * Returns 0 if a subject with the object's smack could
1023  * write to the task, an error code otherwise.
1024  */
1025 static int smack_file_send_sigiotask(struct task_struct *tsk,
1026 				     struct fown_struct *fown, int signum)
1027 {
1028 	struct file *file;
1029 	int rc;
1030 	char *tsp = tsk->cred->security;
1031 	struct smk_audit_info ad;
1032 
1033 	/*
1034 	 * struct fown_struct is never outside the context of a struct file
1035 	 */
1036 	file = container_of(fown, struct file, f_owner);
1037 	/* we don't log here as rc can be overriden */
1038 	rc = smk_access(file->f_security, tsp, MAY_WRITE, NULL);
1039 	if (rc != 0 && has_capability(tsk, CAP_MAC_OVERRIDE))
1040 		rc = 0;
1041 
1042 	smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_TASK);
1043 	smk_ad_setfield_u_tsk(&ad, tsk);
1044 	smack_log(file->f_security, tsp, MAY_WRITE, rc, &ad);
1045 	return rc;
1046 }
1047 
1048 /**
1049  * smack_file_receive - Smack file receive check
1050  * @file: the object
1051  *
1052  * Returns 0 if current has access, error code otherwise
1053  */
1054 static int smack_file_receive(struct file *file)
1055 {
1056 	int may = 0;
1057 	struct smk_audit_info ad;
1058 
1059 	smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_TASK);
1060 	smk_ad_setfield_u_fs_path(&ad, file->f_path);
1061 	/*
1062 	 * This code relies on bitmasks.
1063 	 */
1064 	if (file->f_mode & FMODE_READ)
1065 		may = MAY_READ;
1066 	if (file->f_mode & FMODE_WRITE)
1067 		may |= MAY_WRITE;
1068 
1069 	return smk_curacc(file->f_security, may, &ad);
1070 }
1071 
1072 /*
1073  * Task hooks
1074  */
1075 
1076 /**
1077  * smack_cred_alloc_blank - "allocate" blank task-level security credentials
1078  * @new: the new credentials
1079  * @gfp: the atomicity of any memory allocations
1080  *
1081  * Prepare a blank set of credentials for modification.  This must allocate all
1082  * the memory the LSM module might require such that cred_transfer() can
1083  * complete without error.
1084  */
1085 static int smack_cred_alloc_blank(struct cred *cred, gfp_t gfp)
1086 {
1087 	cred->security = NULL;
1088 	return 0;
1089 }
1090 
1091 
1092 /**
1093  * smack_cred_free - "free" task-level security credentials
1094  * @cred: the credentials in question
1095  *
1096  * Smack isn't using copies of blobs. Everyone
1097  * points to an immutable list. The blobs never go away.
1098  * There is no leak here.
1099  */
1100 static void smack_cred_free(struct cred *cred)
1101 {
1102 	cred->security = NULL;
1103 }
1104 
1105 /**
1106  * smack_cred_prepare - prepare new set of credentials for modification
1107  * @new: the new credentials
1108  * @old: the original credentials
1109  * @gfp: the atomicity of any memory allocations
1110  *
1111  * Prepare a new set of credentials for modification.
1112  */
1113 static int smack_cred_prepare(struct cred *new, const struct cred *old,
1114 			      gfp_t gfp)
1115 {
1116 	new->security = old->security;
1117 	return 0;
1118 }
1119 
1120 /**
1121  * smack_cred_transfer - Transfer the old credentials to the new credentials
1122  * @new: the new credentials
1123  * @old: the original credentials
1124  *
1125  * Fill in a set of blank credentials from another set of credentials.
1126  */
1127 static void smack_cred_transfer(struct cred *new, const struct cred *old)
1128 {
1129 	new->security = old->security;
1130 }
1131 
1132 /**
1133  * smack_kernel_act_as - Set the subjective context in a set of credentials
1134  * @new: points to the set of credentials to be modified.
1135  * @secid: specifies the security ID to be set
1136  *
1137  * Set the security data for a kernel service.
1138  */
1139 static int smack_kernel_act_as(struct cred *new, u32 secid)
1140 {
1141 	char *smack = smack_from_secid(secid);
1142 
1143 	if (smack == NULL)
1144 		return -EINVAL;
1145 
1146 	new->security = smack;
1147 	return 0;
1148 }
1149 
1150 /**
1151  * smack_kernel_create_files_as - Set the file creation label in a set of creds
1152  * @new: points to the set of credentials to be modified
1153  * @inode: points to the inode to use as a reference
1154  *
1155  * Set the file creation context in a set of credentials to the same
1156  * as the objective context of the specified inode
1157  */
1158 static int smack_kernel_create_files_as(struct cred *new,
1159 					struct inode *inode)
1160 {
1161 	struct inode_smack *isp = inode->i_security;
1162 
1163 	new->security = isp->smk_inode;
1164 	return 0;
1165 }
1166 
1167 /**
1168  * smk_curacc_on_task - helper to log task related access
1169  * @p: the task object
1170  * @access : the access requested
1171  *
1172  * Return 0 if access is permitted
1173  */
1174 static int smk_curacc_on_task(struct task_struct *p, int access)
1175 {
1176 	struct smk_audit_info ad;
1177 
1178 	smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_TASK);
1179 	smk_ad_setfield_u_tsk(&ad, p);
1180 	return smk_curacc(task_security(p), access, &ad);
1181 }
1182 
1183 /**
1184  * smack_task_setpgid - Smack check on setting pgid
1185  * @p: the task object
1186  * @pgid: unused
1187  *
1188  * Return 0 if write access is permitted
1189  */
1190 static int smack_task_setpgid(struct task_struct *p, pid_t pgid)
1191 {
1192 	return smk_curacc_on_task(p, MAY_WRITE);
1193 }
1194 
1195 /**
1196  * smack_task_getpgid - Smack access check for getpgid
1197  * @p: the object task
1198  *
1199  * Returns 0 if current can read the object task, error code otherwise
1200  */
1201 static int smack_task_getpgid(struct task_struct *p)
1202 {
1203 	return smk_curacc_on_task(p, MAY_READ);
1204 }
1205 
1206 /**
1207  * smack_task_getsid - Smack access check for getsid
1208  * @p: the object task
1209  *
1210  * Returns 0 if current can read the object task, error code otherwise
1211  */
1212 static int smack_task_getsid(struct task_struct *p)
1213 {
1214 	return smk_curacc_on_task(p, MAY_READ);
1215 }
1216 
1217 /**
1218  * smack_task_getsecid - get the secid of the task
1219  * @p: the object task
1220  * @secid: where to put the result
1221  *
1222  * Sets the secid to contain a u32 version of the smack label.
1223  */
1224 static void smack_task_getsecid(struct task_struct *p, u32 *secid)
1225 {
1226 	*secid = smack_to_secid(task_security(p));
1227 }
1228 
1229 /**
1230  * smack_task_setnice - Smack check on setting nice
1231  * @p: the task object
1232  * @nice: unused
1233  *
1234  * Return 0 if write access is permitted
1235  */
1236 static int smack_task_setnice(struct task_struct *p, int nice)
1237 {
1238 	int rc;
1239 
1240 	rc = cap_task_setnice(p, nice);
1241 	if (rc == 0)
1242 		rc = smk_curacc_on_task(p, MAY_WRITE);
1243 	return rc;
1244 }
1245 
1246 /**
1247  * smack_task_setioprio - Smack check on setting ioprio
1248  * @p: the task object
1249  * @ioprio: unused
1250  *
1251  * Return 0 if write access is permitted
1252  */
1253 static int smack_task_setioprio(struct task_struct *p, int ioprio)
1254 {
1255 	int rc;
1256 
1257 	rc = cap_task_setioprio(p, ioprio);
1258 	if (rc == 0)
1259 		rc = smk_curacc_on_task(p, MAY_WRITE);
1260 	return rc;
1261 }
1262 
1263 /**
1264  * smack_task_getioprio - Smack check on reading ioprio
1265  * @p: the task object
1266  *
1267  * Return 0 if read access is permitted
1268  */
1269 static int smack_task_getioprio(struct task_struct *p)
1270 {
1271 	return smk_curacc_on_task(p, MAY_READ);
1272 }
1273 
1274 /**
1275  * smack_task_setscheduler - Smack check on setting scheduler
1276  * @p: the task object
1277  * @policy: unused
1278  * @lp: unused
1279  *
1280  * Return 0 if read access is permitted
1281  */
1282 static int smack_task_setscheduler(struct task_struct *p, int policy,
1283 				   struct sched_param *lp)
1284 {
1285 	int rc;
1286 
1287 	rc = cap_task_setscheduler(p, policy, lp);
1288 	if (rc == 0)
1289 		rc = smk_curacc_on_task(p, MAY_WRITE);
1290 	return rc;
1291 }
1292 
1293 /**
1294  * smack_task_getscheduler - Smack check on reading scheduler
1295  * @p: the task object
1296  *
1297  * Return 0 if read access is permitted
1298  */
1299 static int smack_task_getscheduler(struct task_struct *p)
1300 {
1301 	return smk_curacc_on_task(p, MAY_READ);
1302 }
1303 
1304 /**
1305  * smack_task_movememory - Smack check on moving memory
1306  * @p: the task object
1307  *
1308  * Return 0 if write access is permitted
1309  */
1310 static int smack_task_movememory(struct task_struct *p)
1311 {
1312 	return smk_curacc_on_task(p, MAY_WRITE);
1313 }
1314 
1315 /**
1316  * smack_task_kill - Smack check on signal delivery
1317  * @p: the task object
1318  * @info: unused
1319  * @sig: unused
1320  * @secid: identifies the smack to use in lieu of current's
1321  *
1322  * Return 0 if write access is permitted
1323  *
1324  * The secid behavior is an artifact of an SELinux hack
1325  * in the USB code. Someday it may go away.
1326  */
1327 static int smack_task_kill(struct task_struct *p, struct siginfo *info,
1328 			   int sig, u32 secid)
1329 {
1330 	struct smk_audit_info ad;
1331 
1332 	smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_TASK);
1333 	smk_ad_setfield_u_tsk(&ad, p);
1334 	/*
1335 	 * Sending a signal requires that the sender
1336 	 * can write the receiver.
1337 	 */
1338 	if (secid == 0)
1339 		return smk_curacc(task_security(p), MAY_WRITE, &ad);
1340 	/*
1341 	 * If the secid isn't 0 we're dealing with some USB IO
1342 	 * specific behavior. This is not clean. For one thing
1343 	 * we can't take privilege into account.
1344 	 */
1345 	return smk_access(smack_from_secid(secid), task_security(p),
1346 			  MAY_WRITE, &ad);
1347 }
1348 
1349 /**
1350  * smack_task_wait - Smack access check for waiting
1351  * @p: task to wait for
1352  *
1353  * Returns 0 if current can wait for p, error code otherwise
1354  */
1355 static int smack_task_wait(struct task_struct *p)
1356 {
1357 	struct smk_audit_info ad;
1358 	char *sp = current_security();
1359 	char *tsp = task_security(p);
1360 	int rc;
1361 
1362 	/* we don't log here, we can be overriden */
1363 	rc = smk_access(sp, tsp, MAY_WRITE, NULL);
1364 	if (rc == 0)
1365 		goto out_log;
1366 
1367 	/*
1368 	 * Allow the operation to succeed if either task
1369 	 * has privilege to perform operations that might
1370 	 * account for the smack labels having gotten to
1371 	 * be different in the first place.
1372 	 *
1373 	 * This breaks the strict subject/object access
1374 	 * control ideal, taking the object's privilege
1375 	 * state into account in the decision as well as
1376 	 * the smack value.
1377 	 */
1378 	if (capable(CAP_MAC_OVERRIDE) || has_capability(p, CAP_MAC_OVERRIDE))
1379 		rc = 0;
1380 	/* we log only if we didn't get overriden */
1381  out_log:
1382 	smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_TASK);
1383 	smk_ad_setfield_u_tsk(&ad, p);
1384 	smack_log(sp, tsp, MAY_WRITE, rc, &ad);
1385 	return rc;
1386 }
1387 
1388 /**
1389  * smack_task_to_inode - copy task smack into the inode blob
1390  * @p: task to copy from
1391  * @inode: inode to copy to
1392  *
1393  * Sets the smack pointer in the inode security blob
1394  */
1395 static void smack_task_to_inode(struct task_struct *p, struct inode *inode)
1396 {
1397 	struct inode_smack *isp = inode->i_security;
1398 	isp->smk_inode = task_security(p);
1399 }
1400 
1401 /*
1402  * Socket hooks.
1403  */
1404 
1405 /**
1406  * smack_sk_alloc_security - Allocate a socket blob
1407  * @sk: the socket
1408  * @family: unused
1409  * @gfp_flags: memory allocation flags
1410  *
1411  * Assign Smack pointers to current
1412  *
1413  * Returns 0 on success, -ENOMEM is there's no memory
1414  */
1415 static int smack_sk_alloc_security(struct sock *sk, int family, gfp_t gfp_flags)
1416 {
1417 	char *csp = current_security();
1418 	struct socket_smack *ssp;
1419 
1420 	ssp = kzalloc(sizeof(struct socket_smack), gfp_flags);
1421 	if (ssp == NULL)
1422 		return -ENOMEM;
1423 
1424 	ssp->smk_in = csp;
1425 	ssp->smk_out = csp;
1426 	ssp->smk_packet[0] = '\0';
1427 
1428 	sk->sk_security = ssp;
1429 
1430 	return 0;
1431 }
1432 
1433 /**
1434  * smack_sk_free_security - Free a socket blob
1435  * @sk: the socket
1436  *
1437  * Clears the blob pointer
1438  */
1439 static void smack_sk_free_security(struct sock *sk)
1440 {
1441 	kfree(sk->sk_security);
1442 }
1443 
1444 /**
1445 * smack_host_label - check host based restrictions
1446 * @sip: the object end
1447 *
1448 * looks for host based access restrictions
1449 *
1450 * This version will only be appropriate for really small sets of single label
1451 * hosts.  The caller is responsible for ensuring that the RCU read lock is
1452 * taken before calling this function.
1453 *
1454 * Returns the label of the far end or NULL if it's not special.
1455 */
1456 static char *smack_host_label(struct sockaddr_in *sip)
1457 {
1458 	struct smk_netlbladdr *snp;
1459 	struct in_addr *siap = &sip->sin_addr;
1460 
1461 	if (siap->s_addr == 0)
1462 		return NULL;
1463 
1464 	list_for_each_entry_rcu(snp, &smk_netlbladdr_list, list)
1465 		/*
1466 		* we break after finding the first match because
1467 		* the list is sorted from longest to shortest mask
1468 		* so we have found the most specific match
1469 		*/
1470 		if ((&snp->smk_host.sin_addr)->s_addr ==
1471 		    (siap->s_addr & (&snp->smk_mask)->s_addr)) {
1472 			/* we have found the special CIPSO option */
1473 			if (snp->smk_label == smack_cipso_option)
1474 				return NULL;
1475 			return snp->smk_label;
1476 		}
1477 
1478 	return NULL;
1479 }
1480 
1481 /**
1482  * smack_set_catset - convert a capset to netlabel mls categories
1483  * @catset: the Smack categories
1484  * @sap: where to put the netlabel categories
1485  *
1486  * Allocates and fills attr.mls.cat
1487  */
1488 static void smack_set_catset(char *catset, struct netlbl_lsm_secattr *sap)
1489 {
1490 	unsigned char *cp;
1491 	unsigned char m;
1492 	int cat;
1493 	int rc;
1494 	int byte;
1495 
1496 	if (!catset)
1497 		return;
1498 
1499 	sap->flags |= NETLBL_SECATTR_MLS_CAT;
1500 	sap->attr.mls.cat = netlbl_secattr_catmap_alloc(GFP_ATOMIC);
1501 	sap->attr.mls.cat->startbit = 0;
1502 
1503 	for (cat = 1, cp = catset, byte = 0; byte < SMK_LABELLEN; cp++, byte++)
1504 		for (m = 0x80; m != 0; m >>= 1, cat++) {
1505 			if ((m & *cp) == 0)
1506 				continue;
1507 			rc = netlbl_secattr_catmap_setbit(sap->attr.mls.cat,
1508 							  cat, GFP_ATOMIC);
1509 		}
1510 }
1511 
1512 /**
1513  * smack_to_secattr - fill a secattr from a smack value
1514  * @smack: the smack value
1515  * @nlsp: where the result goes
1516  *
1517  * Casey says that CIPSO is good enough for now.
1518  * It can be used to effect.
1519  * It can also be abused to effect when necessary.
1520  * Appologies to the TSIG group in general and GW in particular.
1521  */
1522 static void smack_to_secattr(char *smack, struct netlbl_lsm_secattr *nlsp)
1523 {
1524 	struct smack_cipso cipso;
1525 	int rc;
1526 
1527 	nlsp->domain = smack;
1528 	nlsp->flags = NETLBL_SECATTR_DOMAIN | NETLBL_SECATTR_MLS_LVL;
1529 
1530 	rc = smack_to_cipso(smack, &cipso);
1531 	if (rc == 0) {
1532 		nlsp->attr.mls.lvl = cipso.smk_level;
1533 		smack_set_catset(cipso.smk_catset, nlsp);
1534 	} else {
1535 		nlsp->attr.mls.lvl = smack_cipso_direct;
1536 		smack_set_catset(smack, nlsp);
1537 	}
1538 }
1539 
1540 /**
1541  * smack_netlabel - Set the secattr on a socket
1542  * @sk: the socket
1543  * @labeled: socket label scheme
1544  *
1545  * Convert the outbound smack value (smk_out) to a
1546  * secattr and attach it to the socket.
1547  *
1548  * Returns 0 on success or an error code
1549  */
1550 static int smack_netlabel(struct sock *sk, int labeled)
1551 {
1552 	struct socket_smack *ssp = sk->sk_security;
1553 	struct netlbl_lsm_secattr secattr;
1554 	int rc = 0;
1555 
1556 	/*
1557 	 * Usually the netlabel code will handle changing the
1558 	 * packet labeling based on the label.
1559 	 * The case of a single label host is different, because
1560 	 * a single label host should never get a labeled packet
1561 	 * even though the label is usually associated with a packet
1562 	 * label.
1563 	 */
1564 	local_bh_disable();
1565 	bh_lock_sock_nested(sk);
1566 
1567 	if (ssp->smk_out == smack_net_ambient ||
1568 	    labeled == SMACK_UNLABELED_SOCKET)
1569 		netlbl_sock_delattr(sk);
1570 	else {
1571 		netlbl_secattr_init(&secattr);
1572 		smack_to_secattr(ssp->smk_out, &secattr);
1573 		rc = netlbl_sock_setattr(sk, sk->sk_family, &secattr);
1574 		netlbl_secattr_destroy(&secattr);
1575 	}
1576 
1577 	bh_unlock_sock(sk);
1578 	local_bh_enable();
1579 
1580 	return rc;
1581 }
1582 
1583 /**
1584  * smack_netlbel_send - Set the secattr on a socket and perform access checks
1585  * @sk: the socket
1586  * @sap: the destination address
1587  *
1588  * Set the correct secattr for the given socket based on the destination
1589  * address and perform any outbound access checks needed.
1590  *
1591  * Returns 0 on success or an error code.
1592  *
1593  */
1594 static int smack_netlabel_send(struct sock *sk, struct sockaddr_in *sap)
1595 {
1596 	int rc;
1597 	int sk_lbl;
1598 	char *hostsp;
1599 	struct socket_smack *ssp = sk->sk_security;
1600 	struct smk_audit_info ad;
1601 
1602 	rcu_read_lock();
1603 	hostsp = smack_host_label(sap);
1604 	if (hostsp != NULL) {
1605 		sk_lbl = SMACK_UNLABELED_SOCKET;
1606 #ifdef CONFIG_AUDIT
1607 		smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_NET);
1608 		ad.a.u.net.family = sap->sin_family;
1609 		ad.a.u.net.dport = sap->sin_port;
1610 		ad.a.u.net.v4info.daddr = sap->sin_addr.s_addr;
1611 #endif
1612 		rc = smk_access(ssp->smk_out, hostsp, MAY_WRITE, &ad);
1613 	} else {
1614 		sk_lbl = SMACK_CIPSO_SOCKET;
1615 		rc = 0;
1616 	}
1617 	rcu_read_unlock();
1618 	if (rc != 0)
1619 		return rc;
1620 
1621 	return smack_netlabel(sk, sk_lbl);
1622 }
1623 
1624 /**
1625  * smack_inode_setsecurity - set smack xattrs
1626  * @inode: the object
1627  * @name: attribute name
1628  * @value: attribute value
1629  * @size: size of the attribute
1630  * @flags: unused
1631  *
1632  * Sets the named attribute in the appropriate blob
1633  *
1634  * Returns 0 on success, or an error code
1635  */
1636 static int smack_inode_setsecurity(struct inode *inode, const char *name,
1637 				   const void *value, size_t size, int flags)
1638 {
1639 	char *sp;
1640 	struct inode_smack *nsp = inode->i_security;
1641 	struct socket_smack *ssp;
1642 	struct socket *sock;
1643 	int rc = 0;
1644 
1645 	if (value == NULL || size > SMK_LABELLEN || size == 0)
1646 		return -EACCES;
1647 
1648 	sp = smk_import(value, size);
1649 	if (sp == NULL)
1650 		return -EINVAL;
1651 
1652 	if (strcmp(name, XATTR_SMACK_SUFFIX) == 0) {
1653 		nsp->smk_inode = sp;
1654 		nsp->smk_flags |= SMK_INODE_INSTANT;
1655 		return 0;
1656 	}
1657 	/*
1658 	 * The rest of the Smack xattrs are only on sockets.
1659 	 */
1660 	if (inode->i_sb->s_magic != SOCKFS_MAGIC)
1661 		return -EOPNOTSUPP;
1662 
1663 	sock = SOCKET_I(inode);
1664 	if (sock == NULL || sock->sk == NULL)
1665 		return -EOPNOTSUPP;
1666 
1667 	ssp = sock->sk->sk_security;
1668 
1669 	if (strcmp(name, XATTR_SMACK_IPIN) == 0)
1670 		ssp->smk_in = sp;
1671 	else if (strcmp(name, XATTR_SMACK_IPOUT) == 0) {
1672 		ssp->smk_out = sp;
1673 		rc = smack_netlabel(sock->sk, SMACK_CIPSO_SOCKET);
1674 		if (rc != 0)
1675 			printk(KERN_WARNING "Smack: \"%s\" netlbl error %d.\n",
1676 			       __func__, -rc);
1677 	} else
1678 		return -EOPNOTSUPP;
1679 
1680 	return 0;
1681 }
1682 
1683 /**
1684  * smack_socket_post_create - finish socket setup
1685  * @sock: the socket
1686  * @family: protocol family
1687  * @type: unused
1688  * @protocol: unused
1689  * @kern: unused
1690  *
1691  * Sets the netlabel information on the socket
1692  *
1693  * Returns 0 on success, and error code otherwise
1694  */
1695 static int smack_socket_post_create(struct socket *sock, int family,
1696 				    int type, int protocol, int kern)
1697 {
1698 	if (family != PF_INET || sock->sk == NULL)
1699 		return 0;
1700 	/*
1701 	 * Set the outbound netlbl.
1702 	 */
1703 	return smack_netlabel(sock->sk, SMACK_CIPSO_SOCKET);
1704 }
1705 
1706 /**
1707  * smack_socket_connect - connect access check
1708  * @sock: the socket
1709  * @sap: the other end
1710  * @addrlen: size of sap
1711  *
1712  * Verifies that a connection may be possible
1713  *
1714  * Returns 0 on success, and error code otherwise
1715  */
1716 static int smack_socket_connect(struct socket *sock, struct sockaddr *sap,
1717 				int addrlen)
1718 {
1719 	if (sock->sk == NULL || sock->sk->sk_family != PF_INET)
1720 		return 0;
1721 	if (addrlen < sizeof(struct sockaddr_in))
1722 		return -EINVAL;
1723 
1724 	return smack_netlabel_send(sock->sk, (struct sockaddr_in *)sap);
1725 }
1726 
1727 /**
1728  * smack_flags_to_may - convert S_ to MAY_ values
1729  * @flags: the S_ value
1730  *
1731  * Returns the equivalent MAY_ value
1732  */
1733 static int smack_flags_to_may(int flags)
1734 {
1735 	int may = 0;
1736 
1737 	if (flags & S_IRUGO)
1738 		may |= MAY_READ;
1739 	if (flags & S_IWUGO)
1740 		may |= MAY_WRITE;
1741 	if (flags & S_IXUGO)
1742 		may |= MAY_EXEC;
1743 
1744 	return may;
1745 }
1746 
1747 /**
1748  * smack_msg_msg_alloc_security - Set the security blob for msg_msg
1749  * @msg: the object
1750  *
1751  * Returns 0
1752  */
1753 static int smack_msg_msg_alloc_security(struct msg_msg *msg)
1754 {
1755 	msg->security = current_security();
1756 	return 0;
1757 }
1758 
1759 /**
1760  * smack_msg_msg_free_security - Clear the security blob for msg_msg
1761  * @msg: the object
1762  *
1763  * Clears the blob pointer
1764  */
1765 static void smack_msg_msg_free_security(struct msg_msg *msg)
1766 {
1767 	msg->security = NULL;
1768 }
1769 
1770 /**
1771  * smack_of_shm - the smack pointer for the shm
1772  * @shp: the object
1773  *
1774  * Returns a pointer to the smack value
1775  */
1776 static char *smack_of_shm(struct shmid_kernel *shp)
1777 {
1778 	return (char *)shp->shm_perm.security;
1779 }
1780 
1781 /**
1782  * smack_shm_alloc_security - Set the security blob for shm
1783  * @shp: the object
1784  *
1785  * Returns 0
1786  */
1787 static int smack_shm_alloc_security(struct shmid_kernel *shp)
1788 {
1789 	struct kern_ipc_perm *isp = &shp->shm_perm;
1790 
1791 	isp->security = current_security();
1792 	return 0;
1793 }
1794 
1795 /**
1796  * smack_shm_free_security - Clear the security blob for shm
1797  * @shp: the object
1798  *
1799  * Clears the blob pointer
1800  */
1801 static void smack_shm_free_security(struct shmid_kernel *shp)
1802 {
1803 	struct kern_ipc_perm *isp = &shp->shm_perm;
1804 
1805 	isp->security = NULL;
1806 }
1807 
1808 /**
1809  * smk_curacc_shm : check if current has access on shm
1810  * @shp : the object
1811  * @access : access requested
1812  *
1813  * Returns 0 if current has the requested access, error code otherwise
1814  */
1815 static int smk_curacc_shm(struct shmid_kernel *shp, int access)
1816 {
1817 	char *ssp = smack_of_shm(shp);
1818 	struct smk_audit_info ad;
1819 
1820 #ifdef CONFIG_AUDIT
1821 	smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_IPC);
1822 	ad.a.u.ipc_id = shp->shm_perm.id;
1823 #endif
1824 	return smk_curacc(ssp, access, &ad);
1825 }
1826 
1827 /**
1828  * smack_shm_associate - Smack access check for shm
1829  * @shp: the object
1830  * @shmflg: access requested
1831  *
1832  * Returns 0 if current has the requested access, error code otherwise
1833  */
1834 static int smack_shm_associate(struct shmid_kernel *shp, int shmflg)
1835 {
1836 	int may;
1837 
1838 	may = smack_flags_to_may(shmflg);
1839 	return smk_curacc_shm(shp, may);
1840 }
1841 
1842 /**
1843  * smack_shm_shmctl - Smack access check for shm
1844  * @shp: the object
1845  * @cmd: what it wants to do
1846  *
1847  * Returns 0 if current has the requested access, error code otherwise
1848  */
1849 static int smack_shm_shmctl(struct shmid_kernel *shp, int cmd)
1850 {
1851 	int may;
1852 
1853 	switch (cmd) {
1854 	case IPC_STAT:
1855 	case SHM_STAT:
1856 		may = MAY_READ;
1857 		break;
1858 	case IPC_SET:
1859 	case SHM_LOCK:
1860 	case SHM_UNLOCK:
1861 	case IPC_RMID:
1862 		may = MAY_READWRITE;
1863 		break;
1864 	case IPC_INFO:
1865 	case SHM_INFO:
1866 		/*
1867 		 * System level information.
1868 		 */
1869 		return 0;
1870 	default:
1871 		return -EINVAL;
1872 	}
1873 	return smk_curacc_shm(shp, may);
1874 }
1875 
1876 /**
1877  * smack_shm_shmat - Smack access for shmat
1878  * @shp: the object
1879  * @shmaddr: unused
1880  * @shmflg: access requested
1881  *
1882  * Returns 0 if current has the requested access, error code otherwise
1883  */
1884 static int smack_shm_shmat(struct shmid_kernel *shp, char __user *shmaddr,
1885 			   int shmflg)
1886 {
1887 	int may;
1888 
1889 	may = smack_flags_to_may(shmflg);
1890 	return smk_curacc_shm(shp, may);
1891 }
1892 
1893 /**
1894  * smack_of_sem - the smack pointer for the sem
1895  * @sma: the object
1896  *
1897  * Returns a pointer to the smack value
1898  */
1899 static char *smack_of_sem(struct sem_array *sma)
1900 {
1901 	return (char *)sma->sem_perm.security;
1902 }
1903 
1904 /**
1905  * smack_sem_alloc_security - Set the security blob for sem
1906  * @sma: the object
1907  *
1908  * Returns 0
1909  */
1910 static int smack_sem_alloc_security(struct sem_array *sma)
1911 {
1912 	struct kern_ipc_perm *isp = &sma->sem_perm;
1913 
1914 	isp->security = current_security();
1915 	return 0;
1916 }
1917 
1918 /**
1919  * smack_sem_free_security - Clear the security blob for sem
1920  * @sma: the object
1921  *
1922  * Clears the blob pointer
1923  */
1924 static void smack_sem_free_security(struct sem_array *sma)
1925 {
1926 	struct kern_ipc_perm *isp = &sma->sem_perm;
1927 
1928 	isp->security = NULL;
1929 }
1930 
1931 /**
1932  * smk_curacc_sem : check if current has access on sem
1933  * @sma : the object
1934  * @access : access requested
1935  *
1936  * Returns 0 if current has the requested access, error code otherwise
1937  */
1938 static int smk_curacc_sem(struct sem_array *sma, int access)
1939 {
1940 	char *ssp = smack_of_sem(sma);
1941 	struct smk_audit_info ad;
1942 
1943 #ifdef CONFIG_AUDIT
1944 	smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_IPC);
1945 	ad.a.u.ipc_id = sma->sem_perm.id;
1946 #endif
1947 	return smk_curacc(ssp, access, &ad);
1948 }
1949 
1950 /**
1951  * smack_sem_associate - Smack access check for sem
1952  * @sma: the object
1953  * @semflg: access requested
1954  *
1955  * Returns 0 if current has the requested access, error code otherwise
1956  */
1957 static int smack_sem_associate(struct sem_array *sma, int semflg)
1958 {
1959 	int may;
1960 
1961 	may = smack_flags_to_may(semflg);
1962 	return smk_curacc_sem(sma, may);
1963 }
1964 
1965 /**
1966  * smack_sem_shmctl - Smack access check for sem
1967  * @sma: the object
1968  * @cmd: what it wants to do
1969  *
1970  * Returns 0 if current has the requested access, error code otherwise
1971  */
1972 static int smack_sem_semctl(struct sem_array *sma, int cmd)
1973 {
1974 	int may;
1975 
1976 	switch (cmd) {
1977 	case GETPID:
1978 	case GETNCNT:
1979 	case GETZCNT:
1980 	case GETVAL:
1981 	case GETALL:
1982 	case IPC_STAT:
1983 	case SEM_STAT:
1984 		may = MAY_READ;
1985 		break;
1986 	case SETVAL:
1987 	case SETALL:
1988 	case IPC_RMID:
1989 	case IPC_SET:
1990 		may = MAY_READWRITE;
1991 		break;
1992 	case IPC_INFO:
1993 	case SEM_INFO:
1994 		/*
1995 		 * System level information
1996 		 */
1997 		return 0;
1998 	default:
1999 		return -EINVAL;
2000 	}
2001 
2002 	return smk_curacc_sem(sma, may);
2003 }
2004 
2005 /**
2006  * smack_sem_semop - Smack checks of semaphore operations
2007  * @sma: the object
2008  * @sops: unused
2009  * @nsops: unused
2010  * @alter: unused
2011  *
2012  * Treated as read and write in all cases.
2013  *
2014  * Returns 0 if access is allowed, error code otherwise
2015  */
2016 static int smack_sem_semop(struct sem_array *sma, struct sembuf *sops,
2017 			   unsigned nsops, int alter)
2018 {
2019 	return smk_curacc_sem(sma, MAY_READWRITE);
2020 }
2021 
2022 /**
2023  * smack_msg_alloc_security - Set the security blob for msg
2024  * @msq: the object
2025  *
2026  * Returns 0
2027  */
2028 static int smack_msg_queue_alloc_security(struct msg_queue *msq)
2029 {
2030 	struct kern_ipc_perm *kisp = &msq->q_perm;
2031 
2032 	kisp->security = current_security();
2033 	return 0;
2034 }
2035 
2036 /**
2037  * smack_msg_free_security - Clear the security blob for msg
2038  * @msq: the object
2039  *
2040  * Clears the blob pointer
2041  */
2042 static void smack_msg_queue_free_security(struct msg_queue *msq)
2043 {
2044 	struct kern_ipc_perm *kisp = &msq->q_perm;
2045 
2046 	kisp->security = NULL;
2047 }
2048 
2049 /**
2050  * smack_of_msq - the smack pointer for the msq
2051  * @msq: the object
2052  *
2053  * Returns a pointer to the smack value
2054  */
2055 static char *smack_of_msq(struct msg_queue *msq)
2056 {
2057 	return (char *)msq->q_perm.security;
2058 }
2059 
2060 /**
2061  * smk_curacc_msq : helper to check if current has access on msq
2062  * @msq : the msq
2063  * @access : access requested
2064  *
2065  * return 0 if current has access, error otherwise
2066  */
2067 static int smk_curacc_msq(struct msg_queue *msq, int access)
2068 {
2069 	char *msp = smack_of_msq(msq);
2070 	struct smk_audit_info ad;
2071 
2072 #ifdef CONFIG_AUDIT
2073 	smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_IPC);
2074 	ad.a.u.ipc_id = msq->q_perm.id;
2075 #endif
2076 	return smk_curacc(msp, access, &ad);
2077 }
2078 
2079 /**
2080  * smack_msg_queue_associate - Smack access check for msg_queue
2081  * @msq: the object
2082  * @msqflg: access requested
2083  *
2084  * Returns 0 if current has the requested access, error code otherwise
2085  */
2086 static int smack_msg_queue_associate(struct msg_queue *msq, int msqflg)
2087 {
2088 	int may;
2089 
2090 	may = smack_flags_to_may(msqflg);
2091 	return smk_curacc_msq(msq, may);
2092 }
2093 
2094 /**
2095  * smack_msg_queue_msgctl - Smack access check for msg_queue
2096  * @msq: the object
2097  * @cmd: what it wants to do
2098  *
2099  * Returns 0 if current has the requested access, error code otherwise
2100  */
2101 static int smack_msg_queue_msgctl(struct msg_queue *msq, int cmd)
2102 {
2103 	int may;
2104 
2105 	switch (cmd) {
2106 	case IPC_STAT:
2107 	case MSG_STAT:
2108 		may = MAY_READ;
2109 		break;
2110 	case IPC_SET:
2111 	case IPC_RMID:
2112 		may = MAY_READWRITE;
2113 		break;
2114 	case IPC_INFO:
2115 	case MSG_INFO:
2116 		/*
2117 		 * System level information
2118 		 */
2119 		return 0;
2120 	default:
2121 		return -EINVAL;
2122 	}
2123 
2124 	return smk_curacc_msq(msq, may);
2125 }
2126 
2127 /**
2128  * smack_msg_queue_msgsnd - Smack access check for msg_queue
2129  * @msq: the object
2130  * @msg: unused
2131  * @msqflg: access requested
2132  *
2133  * Returns 0 if current has the requested access, error code otherwise
2134  */
2135 static int smack_msg_queue_msgsnd(struct msg_queue *msq, struct msg_msg *msg,
2136 				  int msqflg)
2137 {
2138 	int may;
2139 
2140 	may = smack_flags_to_may(msqflg);
2141 	return smk_curacc_msq(msq, may);
2142 }
2143 
2144 /**
2145  * smack_msg_queue_msgsnd - Smack access check for msg_queue
2146  * @msq: the object
2147  * @msg: unused
2148  * @target: unused
2149  * @type: unused
2150  * @mode: unused
2151  *
2152  * Returns 0 if current has read and write access, error code otherwise
2153  */
2154 static int smack_msg_queue_msgrcv(struct msg_queue *msq, struct msg_msg *msg,
2155 			struct task_struct *target, long type, int mode)
2156 {
2157 	return smk_curacc_msq(msq, MAY_READWRITE);
2158 }
2159 
2160 /**
2161  * smack_ipc_permission - Smack access for ipc_permission()
2162  * @ipp: the object permissions
2163  * @flag: access requested
2164  *
2165  * Returns 0 if current has read and write access, error code otherwise
2166  */
2167 static int smack_ipc_permission(struct kern_ipc_perm *ipp, short flag)
2168 {
2169 	char *isp = ipp->security;
2170 	int may = smack_flags_to_may(flag);
2171 	struct smk_audit_info ad;
2172 
2173 #ifdef CONFIG_AUDIT
2174 	smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_IPC);
2175 	ad.a.u.ipc_id = ipp->id;
2176 #endif
2177 	return smk_curacc(isp, may, &ad);
2178 }
2179 
2180 /**
2181  * smack_ipc_getsecid - Extract smack security id
2182  * @ipp: the object permissions
2183  * @secid: where result will be saved
2184  */
2185 static void smack_ipc_getsecid(struct kern_ipc_perm *ipp, u32 *secid)
2186 {
2187 	char *smack = ipp->security;
2188 
2189 	*secid = smack_to_secid(smack);
2190 }
2191 
2192 /**
2193  * smack_d_instantiate - Make sure the blob is correct on an inode
2194  * @opt_dentry: unused
2195  * @inode: the object
2196  *
2197  * Set the inode's security blob if it hasn't been done already.
2198  */
2199 static void smack_d_instantiate(struct dentry *opt_dentry, struct inode *inode)
2200 {
2201 	struct super_block *sbp;
2202 	struct superblock_smack *sbsp;
2203 	struct inode_smack *isp;
2204 	char *csp = current_security();
2205 	char *fetched;
2206 	char *final;
2207 	struct dentry *dp;
2208 
2209 	if (inode == NULL)
2210 		return;
2211 
2212 	isp = inode->i_security;
2213 
2214 	mutex_lock(&isp->smk_lock);
2215 	/*
2216 	 * If the inode is already instantiated
2217 	 * take the quick way out
2218 	 */
2219 	if (isp->smk_flags & SMK_INODE_INSTANT)
2220 		goto unlockandout;
2221 
2222 	sbp = inode->i_sb;
2223 	sbsp = sbp->s_security;
2224 	/*
2225 	 * We're going to use the superblock default label
2226 	 * if there's no label on the file.
2227 	 */
2228 	final = sbsp->smk_default;
2229 
2230 	/*
2231 	 * If this is the root inode the superblock
2232 	 * may be in the process of initialization.
2233 	 * If that is the case use the root value out
2234 	 * of the superblock.
2235 	 */
2236 	if (opt_dentry->d_parent == opt_dentry) {
2237 		isp->smk_inode = sbsp->smk_root;
2238 		isp->smk_flags |= SMK_INODE_INSTANT;
2239 		goto unlockandout;
2240 	}
2241 
2242 	/*
2243 	 * This is pretty hackish.
2244 	 * Casey says that we shouldn't have to do
2245 	 * file system specific code, but it does help
2246 	 * with keeping it simple.
2247 	 */
2248 	switch (sbp->s_magic) {
2249 	case SMACK_MAGIC:
2250 		/*
2251 		 * Casey says that it's a little embarassing
2252 		 * that the smack file system doesn't do
2253 		 * extended attributes.
2254 		 */
2255 		final = smack_known_star.smk_known;
2256 		break;
2257 	case PIPEFS_MAGIC:
2258 		/*
2259 		 * Casey says pipes are easy (?)
2260 		 */
2261 		final = smack_known_star.smk_known;
2262 		break;
2263 	case DEVPTS_SUPER_MAGIC:
2264 		/*
2265 		 * devpts seems content with the label of the task.
2266 		 * Programs that change smack have to treat the
2267 		 * pty with respect.
2268 		 */
2269 		final = csp;
2270 		break;
2271 	case SOCKFS_MAGIC:
2272 		/*
2273 		 * Casey says sockets get the smack of the task.
2274 		 */
2275 		final = csp;
2276 		break;
2277 	case PROC_SUPER_MAGIC:
2278 		/*
2279 		 * Casey says procfs appears not to care.
2280 		 * The superblock default suffices.
2281 		 */
2282 		break;
2283 	case TMPFS_MAGIC:
2284 		/*
2285 		 * Device labels should come from the filesystem,
2286 		 * but watch out, because they're volitile,
2287 		 * getting recreated on every reboot.
2288 		 */
2289 		final = smack_known_star.smk_known;
2290 		/*
2291 		 * No break.
2292 		 *
2293 		 * If a smack value has been set we want to use it,
2294 		 * but since tmpfs isn't giving us the opportunity
2295 		 * to set mount options simulate setting the
2296 		 * superblock default.
2297 		 */
2298 	default:
2299 		/*
2300 		 * This isn't an understood special case.
2301 		 * Get the value from the xattr.
2302 		 *
2303 		 * No xattr support means, alas, no SMACK label.
2304 		 * Use the aforeapplied default.
2305 		 * It would be curious if the label of the task
2306 		 * does not match that assigned.
2307 		 */
2308 		if (inode->i_op->getxattr == NULL)
2309 			break;
2310 		/*
2311 		 * Get the dentry for xattr.
2312 		 */
2313 		if (opt_dentry == NULL) {
2314 			dp = d_find_alias(inode);
2315 			if (dp == NULL)
2316 				break;
2317 		} else {
2318 			dp = dget(opt_dentry);
2319 			if (dp == NULL)
2320 				break;
2321 		}
2322 
2323 		fetched = smk_fetch(inode, dp);
2324 		if (fetched != NULL)
2325 			final = fetched;
2326 
2327 		dput(dp);
2328 		break;
2329 	}
2330 
2331 	if (final == NULL)
2332 		isp->smk_inode = csp;
2333 	else
2334 		isp->smk_inode = final;
2335 
2336 	isp->smk_flags |= SMK_INODE_INSTANT;
2337 
2338 unlockandout:
2339 	mutex_unlock(&isp->smk_lock);
2340 	return;
2341 }
2342 
2343 /**
2344  * smack_getprocattr - Smack process attribute access
2345  * @p: the object task
2346  * @name: the name of the attribute in /proc/.../attr
2347  * @value: where to put the result
2348  *
2349  * Places a copy of the task Smack into value
2350  *
2351  * Returns the length of the smack label or an error code
2352  */
2353 static int smack_getprocattr(struct task_struct *p, char *name, char **value)
2354 {
2355 	char *cp;
2356 	int slen;
2357 
2358 	if (strcmp(name, "current") != 0)
2359 		return -EINVAL;
2360 
2361 	cp = kstrdup(task_security(p), GFP_KERNEL);
2362 	if (cp == NULL)
2363 		return -ENOMEM;
2364 
2365 	slen = strlen(cp);
2366 	*value = cp;
2367 	return slen;
2368 }
2369 
2370 /**
2371  * smack_setprocattr - Smack process attribute setting
2372  * @p: the object task
2373  * @name: the name of the attribute in /proc/.../attr
2374  * @value: the value to set
2375  * @size: the size of the value
2376  *
2377  * Sets the Smack value of the task. Only setting self
2378  * is permitted and only with privilege
2379  *
2380  * Returns the length of the smack label or an error code
2381  */
2382 static int smack_setprocattr(struct task_struct *p, char *name,
2383 			     void *value, size_t size)
2384 {
2385 	struct cred *new;
2386 	char *newsmack;
2387 
2388 	/*
2389 	 * Changing another process' Smack value is too dangerous
2390 	 * and supports no sane use case.
2391 	 */
2392 	if (p != current)
2393 		return -EPERM;
2394 
2395 	if (!capable(CAP_MAC_ADMIN))
2396 		return -EPERM;
2397 
2398 	if (value == NULL || size == 0 || size >= SMK_LABELLEN)
2399 		return -EINVAL;
2400 
2401 	if (strcmp(name, "current") != 0)
2402 		return -EINVAL;
2403 
2404 	newsmack = smk_import(value, size);
2405 	if (newsmack == NULL)
2406 		return -EINVAL;
2407 
2408 	/*
2409 	 * No process is ever allowed the web ("@") label.
2410 	 */
2411 	if (newsmack == smack_known_web.smk_known)
2412 		return -EPERM;
2413 
2414 	new = prepare_creds();
2415 	if (new == NULL)
2416 		return -ENOMEM;
2417 	new->security = newsmack;
2418 	commit_creds(new);
2419 	return size;
2420 }
2421 
2422 /**
2423  * smack_unix_stream_connect - Smack access on UDS
2424  * @sock: one socket
2425  * @other: the other socket
2426  * @newsk: unused
2427  *
2428  * Return 0 if a subject with the smack of sock could access
2429  * an object with the smack of other, otherwise an error code
2430  */
2431 static int smack_unix_stream_connect(struct socket *sock,
2432 				     struct socket *other, struct sock *newsk)
2433 {
2434 	struct inode *sp = SOCK_INODE(sock);
2435 	struct inode *op = SOCK_INODE(other);
2436 	struct smk_audit_info ad;
2437 
2438 	smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_NET);
2439 	smk_ad_setfield_u_net_sk(&ad, other->sk);
2440 	return smk_access(smk_of_inode(sp), smk_of_inode(op),
2441 				 MAY_READWRITE, &ad);
2442 }
2443 
2444 /**
2445  * smack_unix_may_send - Smack access on UDS
2446  * @sock: one socket
2447  * @other: the other socket
2448  *
2449  * Return 0 if a subject with the smack of sock could access
2450  * an object with the smack of other, otherwise an error code
2451  */
2452 static int smack_unix_may_send(struct socket *sock, struct socket *other)
2453 {
2454 	struct inode *sp = SOCK_INODE(sock);
2455 	struct inode *op = SOCK_INODE(other);
2456 	struct smk_audit_info ad;
2457 
2458 	smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_NET);
2459 	smk_ad_setfield_u_net_sk(&ad, other->sk);
2460 	return smk_access(smk_of_inode(sp), smk_of_inode(op), MAY_WRITE, &ad);
2461 }
2462 
2463 /**
2464  * smack_socket_sendmsg - Smack check based on destination host
2465  * @sock: the socket
2466  * @msg: the message
2467  * @size: the size of the message
2468  *
2469  * Return 0 if the current subject can write to the destination
2470  * host. This is only a question if the destination is a single
2471  * label host.
2472  */
2473 static int smack_socket_sendmsg(struct socket *sock, struct msghdr *msg,
2474 				int size)
2475 {
2476 	struct sockaddr_in *sip = (struct sockaddr_in *) msg->msg_name;
2477 
2478 	/*
2479 	 * Perfectly reasonable for this to be NULL
2480 	 */
2481 	if (sip == NULL || sip->sin_family != AF_INET)
2482 		return 0;
2483 
2484 	return smack_netlabel_send(sock->sk, sip);
2485 }
2486 
2487 
2488 /**
2489  * smack_from_secattr - Convert a netlabel attr.mls.lvl/attr.mls.cat pair to smack
2490  * @sap: netlabel secattr
2491  * @sip: where to put the result
2492  *
2493  * Copies a smack label into sip
2494  */
2495 static void smack_from_secattr(struct netlbl_lsm_secattr *sap, char *sip)
2496 {
2497 	char smack[SMK_LABELLEN];
2498 	char *sp;
2499 	int pcat;
2500 
2501 	if ((sap->flags & NETLBL_SECATTR_MLS_LVL) != 0) {
2502 		/*
2503 		 * Looks like a CIPSO packet.
2504 		 * If there are flags but no level netlabel isn't
2505 		 * behaving the way we expect it to.
2506 		 *
2507 		 * Get the categories, if any
2508 		 * Without guidance regarding the smack value
2509 		 * for the packet fall back on the network
2510 		 * ambient value.
2511 		 */
2512 		memset(smack, '\0', SMK_LABELLEN);
2513 		if ((sap->flags & NETLBL_SECATTR_MLS_CAT) != 0)
2514 			for (pcat = -1;;) {
2515 				pcat = netlbl_secattr_catmap_walk(
2516 					sap->attr.mls.cat, pcat + 1);
2517 				if (pcat < 0)
2518 					break;
2519 				smack_catset_bit(pcat, smack);
2520 			}
2521 		/*
2522 		 * If it is CIPSO using smack direct mapping
2523 		 * we are already done. WeeHee.
2524 		 */
2525 		if (sap->attr.mls.lvl == smack_cipso_direct) {
2526 			memcpy(sip, smack, SMK_MAXLEN);
2527 			return;
2528 		}
2529 		/*
2530 		 * Look it up in the supplied table if it is not
2531 		 * a direct mapping.
2532 		 */
2533 		smack_from_cipso(sap->attr.mls.lvl, smack, sip);
2534 		return;
2535 	}
2536 	if ((sap->flags & NETLBL_SECATTR_SECID) != 0) {
2537 		/*
2538 		 * Looks like a fallback, which gives us a secid.
2539 		 */
2540 		sp = smack_from_secid(sap->attr.secid);
2541 		/*
2542 		 * This has got to be a bug because it is
2543 		 * impossible to specify a fallback without
2544 		 * specifying the label, which will ensure
2545 		 * it has a secid, and the only way to get a
2546 		 * secid is from a fallback.
2547 		 */
2548 		BUG_ON(sp == NULL);
2549 		strncpy(sip, sp, SMK_MAXLEN);
2550 		return;
2551 	}
2552 	/*
2553 	 * Without guidance regarding the smack value
2554 	 * for the packet fall back on the network
2555 	 * ambient value.
2556 	 */
2557 	strncpy(sip, smack_net_ambient, SMK_MAXLEN);
2558 	return;
2559 }
2560 
2561 /**
2562  * smack_socket_sock_rcv_skb - Smack packet delivery access check
2563  * @sk: socket
2564  * @skb: packet
2565  *
2566  * Returns 0 if the packet should be delivered, an error code otherwise
2567  */
2568 static int smack_socket_sock_rcv_skb(struct sock *sk, struct sk_buff *skb)
2569 {
2570 	struct netlbl_lsm_secattr secattr;
2571 	struct socket_smack *ssp = sk->sk_security;
2572 	char smack[SMK_LABELLEN];
2573 	char *csp;
2574 	int rc;
2575 	struct smk_audit_info ad;
2576 	if (sk->sk_family != PF_INET && sk->sk_family != PF_INET6)
2577 		return 0;
2578 
2579 	/*
2580 	 * Translate what netlabel gave us.
2581 	 */
2582 	netlbl_secattr_init(&secattr);
2583 
2584 	rc = netlbl_skbuff_getattr(skb, sk->sk_family, &secattr);
2585 	if (rc == 0) {
2586 		smack_from_secattr(&secattr, smack);
2587 		csp = smack;
2588 	} else
2589 		csp = smack_net_ambient;
2590 
2591 	netlbl_secattr_destroy(&secattr);
2592 
2593 #ifdef CONFIG_AUDIT
2594 	smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_NET);
2595 	ad.a.u.net.family = sk->sk_family;
2596 	ad.a.u.net.netif = skb->skb_iif;
2597 	ipv4_skb_to_auditdata(skb, &ad.a, NULL);
2598 #endif
2599 	/*
2600 	 * Receiving a packet requires that the other end
2601 	 * be able to write here. Read access is not required.
2602 	 * This is the simplist possible security model
2603 	 * for networking.
2604 	 */
2605 	rc = smk_access(csp, ssp->smk_in, MAY_WRITE, &ad);
2606 	if (rc != 0)
2607 		netlbl_skbuff_err(skb, rc, 0);
2608 	return rc;
2609 }
2610 
2611 /**
2612  * smack_socket_getpeersec_stream - pull in packet label
2613  * @sock: the socket
2614  * @optval: user's destination
2615  * @optlen: size thereof
2616  * @len: max thereof
2617  *
2618  * returns zero on success, an error code otherwise
2619  */
2620 static int smack_socket_getpeersec_stream(struct socket *sock,
2621 					  char __user *optval,
2622 					  int __user *optlen, unsigned len)
2623 {
2624 	struct socket_smack *ssp;
2625 	int slen;
2626 	int rc = 0;
2627 
2628 	ssp = sock->sk->sk_security;
2629 	slen = strlen(ssp->smk_packet) + 1;
2630 
2631 	if (slen > len)
2632 		rc = -ERANGE;
2633 	else if (copy_to_user(optval, ssp->smk_packet, slen) != 0)
2634 		rc = -EFAULT;
2635 
2636 	if (put_user(slen, optlen) != 0)
2637 		rc = -EFAULT;
2638 
2639 	return rc;
2640 }
2641 
2642 
2643 /**
2644  * smack_socket_getpeersec_dgram - pull in packet label
2645  * @sock: the socket
2646  * @skb: packet data
2647  * @secid: pointer to where to put the secid of the packet
2648  *
2649  * Sets the netlabel socket state on sk from parent
2650  */
2651 static int smack_socket_getpeersec_dgram(struct socket *sock,
2652 					 struct sk_buff *skb, u32 *secid)
2653 
2654 {
2655 	struct netlbl_lsm_secattr secattr;
2656 	struct sock *sk;
2657 	char smack[SMK_LABELLEN];
2658 	int family = PF_INET;
2659 	u32 s;
2660 	int rc;
2661 
2662 	/*
2663 	 * Only works for families with packets.
2664 	 */
2665 	if (sock != NULL) {
2666 		sk = sock->sk;
2667 		if (sk->sk_family != PF_INET && sk->sk_family != PF_INET6)
2668 			return 0;
2669 		family = sk->sk_family;
2670 	}
2671 	/*
2672 	 * Translate what netlabel gave us.
2673 	 */
2674 	netlbl_secattr_init(&secattr);
2675 	rc = netlbl_skbuff_getattr(skb, family, &secattr);
2676 	if (rc == 0)
2677 		smack_from_secattr(&secattr, smack);
2678 	netlbl_secattr_destroy(&secattr);
2679 
2680 	/*
2681 	 * Give up if we couldn't get anything
2682 	 */
2683 	if (rc != 0)
2684 		return rc;
2685 
2686 	s = smack_to_secid(smack);
2687 	if (s == 0)
2688 		return -EINVAL;
2689 
2690 	*secid = s;
2691 	return 0;
2692 }
2693 
2694 /**
2695  * smack_sock_graft - Initialize a newly created socket with an existing sock
2696  * @sk: child sock
2697  * @parent: parent socket
2698  *
2699  * Set the smk_{in,out} state of an existing sock based on the process that
2700  * is creating the new socket.
2701  */
2702 static void smack_sock_graft(struct sock *sk, struct socket *parent)
2703 {
2704 	struct socket_smack *ssp;
2705 
2706 	if (sk == NULL ||
2707 	    (sk->sk_family != PF_INET && sk->sk_family != PF_INET6))
2708 		return;
2709 
2710 	ssp = sk->sk_security;
2711 	ssp->smk_in = ssp->smk_out = current_security();
2712 	/* cssp->smk_packet is already set in smack_inet_csk_clone() */
2713 }
2714 
2715 /**
2716  * smack_inet_conn_request - Smack access check on connect
2717  * @sk: socket involved
2718  * @skb: packet
2719  * @req: unused
2720  *
2721  * Returns 0 if a task with the packet label could write to
2722  * the socket, otherwise an error code
2723  */
2724 static int smack_inet_conn_request(struct sock *sk, struct sk_buff *skb,
2725 				   struct request_sock *req)
2726 {
2727 	u16 family = sk->sk_family;
2728 	struct socket_smack *ssp = sk->sk_security;
2729 	struct netlbl_lsm_secattr secattr;
2730 	struct sockaddr_in addr;
2731 	struct iphdr *hdr;
2732 	char smack[SMK_LABELLEN];
2733 	int rc;
2734 	struct smk_audit_info ad;
2735 
2736 	/* handle mapped IPv4 packets arriving via IPv6 sockets */
2737 	if (family == PF_INET6 && skb->protocol == htons(ETH_P_IP))
2738 		family = PF_INET;
2739 
2740 	netlbl_secattr_init(&secattr);
2741 	rc = netlbl_skbuff_getattr(skb, family, &secattr);
2742 	if (rc == 0)
2743 		smack_from_secattr(&secattr, smack);
2744 	else
2745 		strncpy(smack, smack_known_huh.smk_known, SMK_MAXLEN);
2746 	netlbl_secattr_destroy(&secattr);
2747 
2748 #ifdef CONFIG_AUDIT
2749 	smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_NET);
2750 	ad.a.u.net.family = family;
2751 	ad.a.u.net.netif = skb->skb_iif;
2752 	ipv4_skb_to_auditdata(skb, &ad.a, NULL);
2753 #endif
2754 	/*
2755 	 * Receiving a packet requires that the other end be able to write
2756 	 * here. Read access is not required.
2757 	 */
2758 	rc = smk_access(smack, ssp->smk_in, MAY_WRITE, &ad);
2759 	if (rc != 0)
2760 		return rc;
2761 
2762 	/*
2763 	 * Save the peer's label in the request_sock so we can later setup
2764 	 * smk_packet in the child socket so that SO_PEERCRED can report it.
2765 	 */
2766 	req->peer_secid = smack_to_secid(smack);
2767 
2768 	/*
2769 	 * We need to decide if we want to label the incoming connection here
2770 	 * if we do we only need to label the request_sock and the stack will
2771 	 * propogate the wire-label to the sock when it is created.
2772 	 */
2773 	hdr = ip_hdr(skb);
2774 	addr.sin_addr.s_addr = hdr->saddr;
2775 	rcu_read_lock();
2776 	if (smack_host_label(&addr) == NULL) {
2777 		rcu_read_unlock();
2778 		netlbl_secattr_init(&secattr);
2779 		smack_to_secattr(smack, &secattr);
2780 		rc = netlbl_req_setattr(req, &secattr);
2781 		netlbl_secattr_destroy(&secattr);
2782 	} else {
2783 		rcu_read_unlock();
2784 		netlbl_req_delattr(req);
2785 	}
2786 
2787 	return rc;
2788 }
2789 
2790 /**
2791  * smack_inet_csk_clone - Copy the connection information to the new socket
2792  * @sk: the new socket
2793  * @req: the connection's request_sock
2794  *
2795  * Transfer the connection's peer label to the newly created socket.
2796  */
2797 static void smack_inet_csk_clone(struct sock *sk,
2798 				 const struct request_sock *req)
2799 {
2800 	struct socket_smack *ssp = sk->sk_security;
2801 	char *smack;
2802 
2803 	if (req->peer_secid != 0) {
2804 		smack = smack_from_secid(req->peer_secid);
2805 		strncpy(ssp->smk_packet, smack, SMK_MAXLEN);
2806 	} else
2807 		ssp->smk_packet[0] = '\0';
2808 }
2809 
2810 /*
2811  * Key management security hooks
2812  *
2813  * Casey has not tested key support very heavily.
2814  * The permission check is most likely too restrictive.
2815  * If you care about keys please have a look.
2816  */
2817 #ifdef CONFIG_KEYS
2818 
2819 /**
2820  * smack_key_alloc - Set the key security blob
2821  * @key: object
2822  * @cred: the credentials to use
2823  * @flags: unused
2824  *
2825  * No allocation required
2826  *
2827  * Returns 0
2828  */
2829 static int smack_key_alloc(struct key *key, const struct cred *cred,
2830 			   unsigned long flags)
2831 {
2832 	key->security = cred->security;
2833 	return 0;
2834 }
2835 
2836 /**
2837  * smack_key_free - Clear the key security blob
2838  * @key: the object
2839  *
2840  * Clear the blob pointer
2841  */
2842 static void smack_key_free(struct key *key)
2843 {
2844 	key->security = NULL;
2845 }
2846 
2847 /*
2848  * smack_key_permission - Smack access on a key
2849  * @key_ref: gets to the object
2850  * @cred: the credentials to use
2851  * @perm: unused
2852  *
2853  * Return 0 if the task has read and write to the object,
2854  * an error code otherwise
2855  */
2856 static int smack_key_permission(key_ref_t key_ref,
2857 				const struct cred *cred, key_perm_t perm)
2858 {
2859 	struct key *keyp;
2860 	struct smk_audit_info ad;
2861 
2862 	keyp = key_ref_to_ptr(key_ref);
2863 	if (keyp == NULL)
2864 		return -EINVAL;
2865 	/*
2866 	 * If the key hasn't been initialized give it access so that
2867 	 * it may do so.
2868 	 */
2869 	if (keyp->security == NULL)
2870 		return 0;
2871 	/*
2872 	 * This should not occur
2873 	 */
2874 	if (cred->security == NULL)
2875 		return -EACCES;
2876 #ifdef CONFIG_AUDIT
2877 	smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_KEY);
2878 	ad.a.u.key_struct.key = keyp->serial;
2879 	ad.a.u.key_struct.key_desc = keyp->description;
2880 #endif
2881 	return smk_access(cred->security, keyp->security,
2882 				 MAY_READWRITE, &ad);
2883 }
2884 #endif /* CONFIG_KEYS */
2885 
2886 /*
2887  * Smack Audit hooks
2888  *
2889  * Audit requires a unique representation of each Smack specific
2890  * rule. This unique representation is used to distinguish the
2891  * object to be audited from remaining kernel objects and also
2892  * works as a glue between the audit hooks.
2893  *
2894  * Since repository entries are added but never deleted, we'll use
2895  * the smack_known label address related to the given audit rule as
2896  * the needed unique representation. This also better fits the smack
2897  * model where nearly everything is a label.
2898  */
2899 #ifdef CONFIG_AUDIT
2900 
2901 /**
2902  * smack_audit_rule_init - Initialize a smack audit rule
2903  * @field: audit rule fields given from user-space (audit.h)
2904  * @op: required testing operator (=, !=, >, <, ...)
2905  * @rulestr: smack label to be audited
2906  * @vrule: pointer to save our own audit rule representation
2907  *
2908  * Prepare to audit cases where (@field @op @rulestr) is true.
2909  * The label to be audited is created if necessay.
2910  */
2911 static int smack_audit_rule_init(u32 field, u32 op, char *rulestr, void **vrule)
2912 {
2913 	char **rule = (char **)vrule;
2914 	*rule = NULL;
2915 
2916 	if (field != AUDIT_SUBJ_USER && field != AUDIT_OBJ_USER)
2917 		return -EINVAL;
2918 
2919 	if (op != Audit_equal && op != Audit_not_equal)
2920 		return -EINVAL;
2921 
2922 	*rule = smk_import(rulestr, 0);
2923 
2924 	return 0;
2925 }
2926 
2927 /**
2928  * smack_audit_rule_known - Distinguish Smack audit rules
2929  * @krule: rule of interest, in Audit kernel representation format
2930  *
2931  * This is used to filter Smack rules from remaining Audit ones.
2932  * If it's proved that this rule belongs to us, the
2933  * audit_rule_match hook will be called to do the final judgement.
2934  */
2935 static int smack_audit_rule_known(struct audit_krule *krule)
2936 {
2937 	struct audit_field *f;
2938 	int i;
2939 
2940 	for (i = 0; i < krule->field_count; i++) {
2941 		f = &krule->fields[i];
2942 
2943 		if (f->type == AUDIT_SUBJ_USER || f->type == AUDIT_OBJ_USER)
2944 			return 1;
2945 	}
2946 
2947 	return 0;
2948 }
2949 
2950 /**
2951  * smack_audit_rule_match - Audit given object ?
2952  * @secid: security id for identifying the object to test
2953  * @field: audit rule flags given from user-space
2954  * @op: required testing operator
2955  * @vrule: smack internal rule presentation
2956  * @actx: audit context associated with the check
2957  *
2958  * The core Audit hook. It's used to take the decision of
2959  * whether to audit or not to audit a given object.
2960  */
2961 static int smack_audit_rule_match(u32 secid, u32 field, u32 op, void *vrule,
2962 				  struct audit_context *actx)
2963 {
2964 	char *smack;
2965 	char *rule = vrule;
2966 
2967 	if (!rule) {
2968 		audit_log(actx, GFP_KERNEL, AUDIT_SELINUX_ERR,
2969 			  "Smack: missing rule\n");
2970 		return -ENOENT;
2971 	}
2972 
2973 	if (field != AUDIT_SUBJ_USER && field != AUDIT_OBJ_USER)
2974 		return 0;
2975 
2976 	smack = smack_from_secid(secid);
2977 
2978 	/*
2979 	 * No need to do string comparisons. If a match occurs,
2980 	 * both pointers will point to the same smack_known
2981 	 * label.
2982 	 */
2983 	if (op == Audit_equal)
2984 		return (rule == smack);
2985 	if (op == Audit_not_equal)
2986 		return (rule != smack);
2987 
2988 	return 0;
2989 }
2990 
2991 /**
2992  * smack_audit_rule_free - free smack rule representation
2993  * @vrule: rule to be freed.
2994  *
2995  * No memory was allocated.
2996  */
2997 static void smack_audit_rule_free(void *vrule)
2998 {
2999 	/* No-op */
3000 }
3001 
3002 #endif /* CONFIG_AUDIT */
3003 
3004 /**
3005  * smack_secid_to_secctx - return the smack label for a secid
3006  * @secid: incoming integer
3007  * @secdata: destination
3008  * @seclen: how long it is
3009  *
3010  * Exists for networking code.
3011  */
3012 static int smack_secid_to_secctx(u32 secid, char **secdata, u32 *seclen)
3013 {
3014 	char *sp = smack_from_secid(secid);
3015 
3016 	*secdata = sp;
3017 	*seclen = strlen(sp);
3018 	return 0;
3019 }
3020 
3021 /**
3022  * smack_secctx_to_secid - return the secid for a smack label
3023  * @secdata: smack label
3024  * @seclen: how long result is
3025  * @secid: outgoing integer
3026  *
3027  * Exists for audit and networking code.
3028  */
3029 static int smack_secctx_to_secid(const char *secdata, u32 seclen, u32 *secid)
3030 {
3031 	*secid = smack_to_secid(secdata);
3032 	return 0;
3033 }
3034 
3035 /**
3036  * smack_release_secctx - don't do anything.
3037  * @secdata: unused
3038  * @seclen: unused
3039  *
3040  * Exists to make sure nothing gets done, and properly
3041  */
3042 static void smack_release_secctx(char *secdata, u32 seclen)
3043 {
3044 }
3045 
3046 static int smack_inode_notifysecctx(struct inode *inode, void *ctx, u32 ctxlen)
3047 {
3048 	return smack_inode_setsecurity(inode, XATTR_SMACK_SUFFIX, ctx, ctxlen, 0);
3049 }
3050 
3051 static int smack_inode_setsecctx(struct dentry *dentry, void *ctx, u32 ctxlen)
3052 {
3053 	return __vfs_setxattr_noperm(dentry, XATTR_NAME_SMACK, ctx, ctxlen, 0);
3054 }
3055 
3056 static int smack_inode_getsecctx(struct inode *inode, void **ctx, u32 *ctxlen)
3057 {
3058 	int len = 0;
3059 	len = smack_inode_getsecurity(inode, XATTR_SMACK_SUFFIX, ctx, true);
3060 
3061 	if (len < 0)
3062 		return len;
3063 	*ctxlen = len;
3064 	return 0;
3065 }
3066 
3067 struct security_operations smack_ops = {
3068 	.name =				"smack",
3069 
3070 	.ptrace_access_check =		smack_ptrace_access_check,
3071 	.ptrace_traceme =		smack_ptrace_traceme,
3072 	.syslog = 			smack_syslog,
3073 
3074 	.sb_alloc_security = 		smack_sb_alloc_security,
3075 	.sb_free_security = 		smack_sb_free_security,
3076 	.sb_copy_data = 		smack_sb_copy_data,
3077 	.sb_kern_mount = 		smack_sb_kern_mount,
3078 	.sb_statfs = 			smack_sb_statfs,
3079 	.sb_mount = 			smack_sb_mount,
3080 	.sb_umount = 			smack_sb_umount,
3081 
3082 	.inode_alloc_security = 	smack_inode_alloc_security,
3083 	.inode_free_security = 		smack_inode_free_security,
3084 	.inode_init_security = 		smack_inode_init_security,
3085 	.inode_link = 			smack_inode_link,
3086 	.inode_unlink = 		smack_inode_unlink,
3087 	.inode_rmdir = 			smack_inode_rmdir,
3088 	.inode_rename = 		smack_inode_rename,
3089 	.inode_permission = 		smack_inode_permission,
3090 	.inode_setattr = 		smack_inode_setattr,
3091 	.inode_getattr = 		smack_inode_getattr,
3092 	.inode_setxattr = 		smack_inode_setxattr,
3093 	.inode_post_setxattr = 		smack_inode_post_setxattr,
3094 	.inode_getxattr = 		smack_inode_getxattr,
3095 	.inode_removexattr = 		smack_inode_removexattr,
3096 	.inode_getsecurity = 		smack_inode_getsecurity,
3097 	.inode_setsecurity = 		smack_inode_setsecurity,
3098 	.inode_listsecurity = 		smack_inode_listsecurity,
3099 	.inode_getsecid =		smack_inode_getsecid,
3100 
3101 	.file_permission = 		smack_file_permission,
3102 	.file_alloc_security = 		smack_file_alloc_security,
3103 	.file_free_security = 		smack_file_free_security,
3104 	.file_ioctl = 			smack_file_ioctl,
3105 	.file_lock = 			smack_file_lock,
3106 	.file_fcntl = 			smack_file_fcntl,
3107 	.file_set_fowner = 		smack_file_set_fowner,
3108 	.file_send_sigiotask = 		smack_file_send_sigiotask,
3109 	.file_receive = 		smack_file_receive,
3110 
3111 	.cred_alloc_blank =		smack_cred_alloc_blank,
3112 	.cred_free =			smack_cred_free,
3113 	.cred_prepare =			smack_cred_prepare,
3114 	.cred_transfer =		smack_cred_transfer,
3115 	.kernel_act_as =		smack_kernel_act_as,
3116 	.kernel_create_files_as =	smack_kernel_create_files_as,
3117 	.task_setpgid = 		smack_task_setpgid,
3118 	.task_getpgid = 		smack_task_getpgid,
3119 	.task_getsid = 			smack_task_getsid,
3120 	.task_getsecid = 		smack_task_getsecid,
3121 	.task_setnice = 		smack_task_setnice,
3122 	.task_setioprio = 		smack_task_setioprio,
3123 	.task_getioprio = 		smack_task_getioprio,
3124 	.task_setscheduler = 		smack_task_setscheduler,
3125 	.task_getscheduler = 		smack_task_getscheduler,
3126 	.task_movememory = 		smack_task_movememory,
3127 	.task_kill = 			smack_task_kill,
3128 	.task_wait = 			smack_task_wait,
3129 	.task_to_inode = 		smack_task_to_inode,
3130 
3131 	.ipc_permission = 		smack_ipc_permission,
3132 	.ipc_getsecid =			smack_ipc_getsecid,
3133 
3134 	.msg_msg_alloc_security = 	smack_msg_msg_alloc_security,
3135 	.msg_msg_free_security = 	smack_msg_msg_free_security,
3136 
3137 	.msg_queue_alloc_security = 	smack_msg_queue_alloc_security,
3138 	.msg_queue_free_security = 	smack_msg_queue_free_security,
3139 	.msg_queue_associate = 		smack_msg_queue_associate,
3140 	.msg_queue_msgctl = 		smack_msg_queue_msgctl,
3141 	.msg_queue_msgsnd = 		smack_msg_queue_msgsnd,
3142 	.msg_queue_msgrcv = 		smack_msg_queue_msgrcv,
3143 
3144 	.shm_alloc_security = 		smack_shm_alloc_security,
3145 	.shm_free_security = 		smack_shm_free_security,
3146 	.shm_associate = 		smack_shm_associate,
3147 	.shm_shmctl = 			smack_shm_shmctl,
3148 	.shm_shmat = 			smack_shm_shmat,
3149 
3150 	.sem_alloc_security = 		smack_sem_alloc_security,
3151 	.sem_free_security = 		smack_sem_free_security,
3152 	.sem_associate = 		smack_sem_associate,
3153 	.sem_semctl = 			smack_sem_semctl,
3154 	.sem_semop = 			smack_sem_semop,
3155 
3156 	.d_instantiate = 		smack_d_instantiate,
3157 
3158 	.getprocattr = 			smack_getprocattr,
3159 	.setprocattr = 			smack_setprocattr,
3160 
3161 	.unix_stream_connect = 		smack_unix_stream_connect,
3162 	.unix_may_send = 		smack_unix_may_send,
3163 
3164 	.socket_post_create = 		smack_socket_post_create,
3165 	.socket_connect =		smack_socket_connect,
3166 	.socket_sendmsg =		smack_socket_sendmsg,
3167 	.socket_sock_rcv_skb = 		smack_socket_sock_rcv_skb,
3168 	.socket_getpeersec_stream =	smack_socket_getpeersec_stream,
3169 	.socket_getpeersec_dgram =	smack_socket_getpeersec_dgram,
3170 	.sk_alloc_security = 		smack_sk_alloc_security,
3171 	.sk_free_security = 		smack_sk_free_security,
3172 	.sock_graft = 			smack_sock_graft,
3173 	.inet_conn_request = 		smack_inet_conn_request,
3174 	.inet_csk_clone =		smack_inet_csk_clone,
3175 
3176  /* key management security hooks */
3177 #ifdef CONFIG_KEYS
3178 	.key_alloc = 			smack_key_alloc,
3179 	.key_free = 			smack_key_free,
3180 	.key_permission = 		smack_key_permission,
3181 #endif /* CONFIG_KEYS */
3182 
3183  /* Audit hooks */
3184 #ifdef CONFIG_AUDIT
3185 	.audit_rule_init =		smack_audit_rule_init,
3186 	.audit_rule_known =		smack_audit_rule_known,
3187 	.audit_rule_match =		smack_audit_rule_match,
3188 	.audit_rule_free =		smack_audit_rule_free,
3189 #endif /* CONFIG_AUDIT */
3190 
3191 	.secid_to_secctx = 		smack_secid_to_secctx,
3192 	.secctx_to_secid = 		smack_secctx_to_secid,
3193 	.release_secctx = 		smack_release_secctx,
3194 	.inode_notifysecctx =		smack_inode_notifysecctx,
3195 	.inode_setsecctx =		smack_inode_setsecctx,
3196 	.inode_getsecctx =		smack_inode_getsecctx,
3197 };
3198 
3199 
3200 static __init void init_smack_know_list(void)
3201 {
3202 	list_add(&smack_known_huh.list, &smack_known_list);
3203 	list_add(&smack_known_hat.list, &smack_known_list);
3204 	list_add(&smack_known_star.list, &smack_known_list);
3205 	list_add(&smack_known_floor.list, &smack_known_list);
3206 	list_add(&smack_known_invalid.list, &smack_known_list);
3207 	list_add(&smack_known_web.list, &smack_known_list);
3208 }
3209 
3210 /**
3211  * smack_init - initialize the smack system
3212  *
3213  * Returns 0
3214  */
3215 static __init int smack_init(void)
3216 {
3217 	struct cred *cred;
3218 
3219 	if (!security_module_enable(&smack_ops))
3220 		return 0;
3221 
3222 	printk(KERN_INFO "Smack:  Initializing.\n");
3223 
3224 	/*
3225 	 * Set the security state for the initial task.
3226 	 */
3227 	cred = (struct cred *) current->cred;
3228 	cred->security = &smack_known_floor.smk_known;
3229 
3230 	/* initilize the smack_know_list */
3231 	init_smack_know_list();
3232 	/*
3233 	 * Initialize locks
3234 	 */
3235 	spin_lock_init(&smack_known_huh.smk_cipsolock);
3236 	spin_lock_init(&smack_known_hat.smk_cipsolock);
3237 	spin_lock_init(&smack_known_star.smk_cipsolock);
3238 	spin_lock_init(&smack_known_floor.smk_cipsolock);
3239 	spin_lock_init(&smack_known_invalid.smk_cipsolock);
3240 
3241 	/*
3242 	 * Register with LSM
3243 	 */
3244 	if (register_security(&smack_ops))
3245 		panic("smack: Unable to register with kernel.\n");
3246 
3247 	return 0;
3248 }
3249 
3250 /*
3251  * Smack requires early initialization in order to label
3252  * all processes and objects when they are created.
3253  */
3254 security_initcall(smack_init);
3255