xref: /openbmc/linux/security/smack/smack_lsm.c (revision baa7eb025ab14f3cba2e35c0a8648f9c9f01d24f)
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 typefrom_file)
161 {
162 	int rc = 0;
163 	char *sp = current_security();
164 
165 	if (capable(CAP_MAC_OVERRIDE))
166 		return 0;
167 
168 	 if (sp != smack_known_floor.smk_known)
169 		rc = -EACCES;
170 
171 	return rc;
172 }
173 
174 
175 /*
176  * Superblock Hooks.
177  */
178 
179 /**
180  * smack_sb_alloc_security - allocate a superblock blob
181  * @sb: the superblock getting the blob
182  *
183  * Returns 0 on success or -ENOMEM on error.
184  */
185 static int smack_sb_alloc_security(struct super_block *sb)
186 {
187 	struct superblock_smack *sbsp;
188 
189 	sbsp = kzalloc(sizeof(struct superblock_smack), GFP_KERNEL);
190 
191 	if (sbsp == NULL)
192 		return -ENOMEM;
193 
194 	sbsp->smk_root = smack_known_floor.smk_known;
195 	sbsp->smk_default = smack_known_floor.smk_known;
196 	sbsp->smk_floor = smack_known_floor.smk_known;
197 	sbsp->smk_hat = smack_known_hat.smk_known;
198 	sbsp->smk_initialized = 0;
199 	spin_lock_init(&sbsp->smk_sblock);
200 
201 	sb->s_security = sbsp;
202 
203 	return 0;
204 }
205 
206 /**
207  * smack_sb_free_security - free a superblock blob
208  * @sb: the superblock getting the blob
209  *
210  */
211 static void smack_sb_free_security(struct super_block *sb)
212 {
213 	kfree(sb->s_security);
214 	sb->s_security = NULL;
215 }
216 
217 /**
218  * smack_sb_copy_data - copy mount options data for processing
219  * @orig: where to start
220  * @smackopts: mount options string
221  *
222  * Returns 0 on success or -ENOMEM on error.
223  *
224  * Copy the Smack specific mount options out of the mount
225  * options list.
226  */
227 static int smack_sb_copy_data(char *orig, char *smackopts)
228 {
229 	char *cp, *commap, *otheropts, *dp;
230 
231 	otheropts = (char *)get_zeroed_page(GFP_KERNEL);
232 	if (otheropts == NULL)
233 		return -ENOMEM;
234 
235 	for (cp = orig, commap = orig; commap != NULL; cp = commap + 1) {
236 		if (strstr(cp, SMK_FSDEFAULT) == cp)
237 			dp = smackopts;
238 		else if (strstr(cp, SMK_FSFLOOR) == cp)
239 			dp = smackopts;
240 		else if (strstr(cp, SMK_FSHAT) == cp)
241 			dp = smackopts;
242 		else if (strstr(cp, SMK_FSROOT) == cp)
243 			dp = smackopts;
244 		else
245 			dp = otheropts;
246 
247 		commap = strchr(cp, ',');
248 		if (commap != NULL)
249 			*commap = '\0';
250 
251 		if (*dp != '\0')
252 			strcat(dp, ",");
253 		strcat(dp, cp);
254 	}
255 
256 	strcpy(orig, otheropts);
257 	free_page((unsigned long)otheropts);
258 
259 	return 0;
260 }
261 
262 /**
263  * smack_sb_kern_mount - Smack specific mount processing
264  * @sb: the file system superblock
265  * @flags: the mount flags
266  * @data: the smack mount options
267  *
268  * Returns 0 on success, an error code on failure
269  */
270 static int smack_sb_kern_mount(struct super_block *sb, int flags, void *data)
271 {
272 	struct dentry *root = sb->s_root;
273 	struct inode *inode = root->d_inode;
274 	struct superblock_smack *sp = sb->s_security;
275 	struct inode_smack *isp;
276 	char *op;
277 	char *commap;
278 	char *nsp;
279 
280 	spin_lock(&sp->smk_sblock);
281 	if (sp->smk_initialized != 0) {
282 		spin_unlock(&sp->smk_sblock);
283 		return 0;
284 	}
285 	sp->smk_initialized = 1;
286 	spin_unlock(&sp->smk_sblock);
287 
288 	for (op = data; op != NULL; op = commap) {
289 		commap = strchr(op, ',');
290 		if (commap != NULL)
291 			*commap++ = '\0';
292 
293 		if (strncmp(op, SMK_FSHAT, strlen(SMK_FSHAT)) == 0) {
294 			op += strlen(SMK_FSHAT);
295 			nsp = smk_import(op, 0);
296 			if (nsp != NULL)
297 				sp->smk_hat = nsp;
298 		} else if (strncmp(op, SMK_FSFLOOR, strlen(SMK_FSFLOOR)) == 0) {
299 			op += strlen(SMK_FSFLOOR);
300 			nsp = smk_import(op, 0);
301 			if (nsp != NULL)
302 				sp->smk_floor = nsp;
303 		} else if (strncmp(op, SMK_FSDEFAULT,
304 				   strlen(SMK_FSDEFAULT)) == 0) {
305 			op += strlen(SMK_FSDEFAULT);
306 			nsp = smk_import(op, 0);
307 			if (nsp != NULL)
308 				sp->smk_default = nsp;
309 		} else if (strncmp(op, SMK_FSROOT, strlen(SMK_FSROOT)) == 0) {
310 			op += strlen(SMK_FSROOT);
311 			nsp = smk_import(op, 0);
312 			if (nsp != NULL)
313 				sp->smk_root = nsp;
314 		}
315 	}
316 
317 	/*
318 	 * Initialize the root inode.
319 	 */
320 	isp = inode->i_security;
321 	if (isp == NULL)
322 		inode->i_security = new_inode_smack(sp->smk_root);
323 	else
324 		isp->smk_inode = sp->smk_root;
325 
326 	return 0;
327 }
328 
329 /**
330  * smack_sb_statfs - Smack check on statfs
331  * @dentry: identifies the file system in question
332  *
333  * Returns 0 if current can read the floor of the filesystem,
334  * and error code otherwise
335  */
336 static int smack_sb_statfs(struct dentry *dentry)
337 {
338 	struct superblock_smack *sbp = dentry->d_sb->s_security;
339 	int rc;
340 	struct smk_audit_info ad;
341 
342 	smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_FS);
343 	smk_ad_setfield_u_fs_path_dentry(&ad, dentry);
344 
345 	rc = smk_curacc(sbp->smk_floor, MAY_READ, &ad);
346 	return rc;
347 }
348 
349 /**
350  * smack_sb_mount - Smack check for mounting
351  * @dev_name: unused
352  * @path: mount point
353  * @type: unused
354  * @flags: unused
355  * @data: unused
356  *
357  * Returns 0 if current can write the floor of the filesystem
358  * being mounted on, an error code otherwise.
359  */
360 static int smack_sb_mount(char *dev_name, struct path *path,
361 			  char *type, unsigned long flags, void *data)
362 {
363 	struct superblock_smack *sbp = path->mnt->mnt_sb->s_security;
364 	struct smk_audit_info ad;
365 
366 	smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_FS);
367 	smk_ad_setfield_u_fs_path(&ad, *path);
368 
369 	return smk_curacc(sbp->smk_floor, MAY_WRITE, &ad);
370 }
371 
372 /**
373  * smack_sb_umount - Smack check for unmounting
374  * @mnt: file system to unmount
375  * @flags: unused
376  *
377  * Returns 0 if current can write the floor of the filesystem
378  * being unmounted, an error code otherwise.
379  */
380 static int smack_sb_umount(struct vfsmount *mnt, int flags)
381 {
382 	struct superblock_smack *sbp;
383 	struct smk_audit_info ad;
384 
385 	smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_FS);
386 	smk_ad_setfield_u_fs_path_dentry(&ad, mnt->mnt_root);
387 	smk_ad_setfield_u_fs_path_mnt(&ad, mnt);
388 
389 	sbp = mnt->mnt_sb->s_security;
390 	return smk_curacc(sbp->smk_floor, MAY_WRITE, &ad);
391 }
392 
393 /*
394  * Inode hooks
395  */
396 
397 /**
398  * smack_inode_alloc_security - allocate an inode blob
399  * @inode: the inode in need of a blob
400  *
401  * Returns 0 if it gets a blob, -ENOMEM otherwise
402  */
403 static int smack_inode_alloc_security(struct inode *inode)
404 {
405 	inode->i_security = new_inode_smack(current_security());
406 	if (inode->i_security == NULL)
407 		return -ENOMEM;
408 	return 0;
409 }
410 
411 /**
412  * smack_inode_free_security - free an inode blob
413  * @inode: the inode with a blob
414  *
415  * Clears the blob pointer in inode
416  */
417 static void smack_inode_free_security(struct inode *inode)
418 {
419 	kfree(inode->i_security);
420 	inode->i_security = NULL;
421 }
422 
423 /**
424  * smack_inode_init_security - copy out the smack from an inode
425  * @inode: the inode
426  * @dir: unused
427  * @name: where to put the attribute name
428  * @value: where to put the attribute value
429  * @len: where to put the length of the attribute
430  *
431  * Returns 0 if it all works out, -ENOMEM if there's no memory
432  */
433 static int smack_inode_init_security(struct inode *inode, struct inode *dir,
434 				     char **name, void **value, size_t *len)
435 {
436 	char *isp = smk_of_inode(inode);
437 
438 	if (name) {
439 		*name = kstrdup(XATTR_SMACK_SUFFIX, GFP_KERNEL);
440 		if (*name == NULL)
441 			return -ENOMEM;
442 	}
443 
444 	if (value) {
445 		*value = kstrdup(isp, GFP_KERNEL);
446 		if (*value == NULL)
447 			return -ENOMEM;
448 	}
449 
450 	if (len)
451 		*len = strlen(isp) + 1;
452 
453 	return 0;
454 }
455 
456 /**
457  * smack_inode_link - Smack check on link
458  * @old_dentry: the existing object
459  * @dir: unused
460  * @new_dentry: the new object
461  *
462  * Returns 0 if access is permitted, an error code otherwise
463  */
464 static int smack_inode_link(struct dentry *old_dentry, struct inode *dir,
465 			    struct dentry *new_dentry)
466 {
467 	char *isp;
468 	struct smk_audit_info ad;
469 	int rc;
470 
471 	smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_FS);
472 	smk_ad_setfield_u_fs_path_dentry(&ad, old_dentry);
473 
474 	isp = smk_of_inode(old_dentry->d_inode);
475 	rc = smk_curacc(isp, MAY_WRITE, &ad);
476 
477 	if (rc == 0 && new_dentry->d_inode != NULL) {
478 		isp = smk_of_inode(new_dentry->d_inode);
479 		smk_ad_setfield_u_fs_path_dentry(&ad, new_dentry);
480 		rc = smk_curacc(isp, MAY_WRITE, &ad);
481 	}
482 
483 	return rc;
484 }
485 
486 /**
487  * smack_inode_unlink - Smack check on inode deletion
488  * @dir: containing directory object
489  * @dentry: file to unlink
490  *
491  * Returns 0 if current can write the containing directory
492  * and the object, error code otherwise
493  */
494 static int smack_inode_unlink(struct inode *dir, struct dentry *dentry)
495 {
496 	struct inode *ip = dentry->d_inode;
497 	struct smk_audit_info ad;
498 	int rc;
499 
500 	smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_FS);
501 	smk_ad_setfield_u_fs_path_dentry(&ad, dentry);
502 
503 	/*
504 	 * You need write access to the thing you're unlinking
505 	 */
506 	rc = smk_curacc(smk_of_inode(ip), MAY_WRITE, &ad);
507 	if (rc == 0) {
508 		/*
509 		 * You also need write access to the containing directory
510 		 */
511 		smk_ad_setfield_u_fs_path_dentry(&ad, NULL);
512 		smk_ad_setfield_u_fs_inode(&ad, dir);
513 		rc = smk_curacc(smk_of_inode(dir), MAY_WRITE, &ad);
514 	}
515 	return rc;
516 }
517 
518 /**
519  * smack_inode_rmdir - Smack check on directory deletion
520  * @dir: containing directory object
521  * @dentry: directory to unlink
522  *
523  * Returns 0 if current can write the containing directory
524  * and the directory, error code otherwise
525  */
526 static int smack_inode_rmdir(struct inode *dir, struct dentry *dentry)
527 {
528 	struct smk_audit_info ad;
529 	int rc;
530 
531 	smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_FS);
532 	smk_ad_setfield_u_fs_path_dentry(&ad, dentry);
533 
534 	/*
535 	 * You need write access to the thing you're removing
536 	 */
537 	rc = smk_curacc(smk_of_inode(dentry->d_inode), MAY_WRITE, &ad);
538 	if (rc == 0) {
539 		/*
540 		 * You also need write access to the containing directory
541 		 */
542 		smk_ad_setfield_u_fs_path_dentry(&ad, NULL);
543 		smk_ad_setfield_u_fs_inode(&ad, dir);
544 		rc = smk_curacc(smk_of_inode(dir), MAY_WRITE, &ad);
545 	}
546 
547 	return rc;
548 }
549 
550 /**
551  * smack_inode_rename - Smack check on rename
552  * @old_inode: the old directory
553  * @old_dentry: unused
554  * @new_inode: the new directory
555  * @new_dentry: unused
556  *
557  * Read and write access is required on both the old and
558  * new directories.
559  *
560  * Returns 0 if access is permitted, an error code otherwise
561  */
562 static int smack_inode_rename(struct inode *old_inode,
563 			      struct dentry *old_dentry,
564 			      struct inode *new_inode,
565 			      struct dentry *new_dentry)
566 {
567 	int rc;
568 	char *isp;
569 	struct smk_audit_info ad;
570 
571 	smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_FS);
572 	smk_ad_setfield_u_fs_path_dentry(&ad, old_dentry);
573 
574 	isp = smk_of_inode(old_dentry->d_inode);
575 	rc = smk_curacc(isp, MAY_READWRITE, &ad);
576 
577 	if (rc == 0 && new_dentry->d_inode != NULL) {
578 		isp = smk_of_inode(new_dentry->d_inode);
579 		smk_ad_setfield_u_fs_path_dentry(&ad, new_dentry);
580 		rc = smk_curacc(isp, MAY_READWRITE, &ad);
581 	}
582 	return rc;
583 }
584 
585 /**
586  * smack_inode_permission - Smack version of permission()
587  * @inode: the inode in question
588  * @mask: the access requested
589  *
590  * This is the important Smack hook.
591  *
592  * Returns 0 if access is permitted, -EACCES otherwise
593  */
594 static int smack_inode_permission(struct inode *inode, int mask)
595 {
596 	struct smk_audit_info ad;
597 
598 	mask &= (MAY_READ|MAY_WRITE|MAY_EXEC|MAY_APPEND);
599 	/*
600 	 * No permission to check. Existence test. Yup, it's there.
601 	 */
602 	if (mask == 0)
603 		return 0;
604 	smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_FS);
605 	smk_ad_setfield_u_fs_inode(&ad, inode);
606 	return smk_curacc(smk_of_inode(inode), mask, &ad);
607 }
608 
609 /**
610  * smack_inode_setattr - Smack check for setting attributes
611  * @dentry: the object
612  * @iattr: for the force flag
613  *
614  * Returns 0 if access is permitted, an error code otherwise
615  */
616 static int smack_inode_setattr(struct dentry *dentry, struct iattr *iattr)
617 {
618 	struct smk_audit_info ad;
619 	/*
620 	 * Need to allow for clearing the setuid bit.
621 	 */
622 	if (iattr->ia_valid & ATTR_FORCE)
623 		return 0;
624 	smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_FS);
625 	smk_ad_setfield_u_fs_path_dentry(&ad, dentry);
626 
627 	return smk_curacc(smk_of_inode(dentry->d_inode), MAY_WRITE, &ad);
628 }
629 
630 /**
631  * smack_inode_getattr - Smack check for getting attributes
632  * @mnt: unused
633  * @dentry: the object
634  *
635  * Returns 0 if access is permitted, an error code otherwise
636  */
637 static int smack_inode_getattr(struct vfsmount *mnt, struct dentry *dentry)
638 {
639 	struct smk_audit_info ad;
640 
641 	smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_FS);
642 	smk_ad_setfield_u_fs_path_dentry(&ad, dentry);
643 	smk_ad_setfield_u_fs_path_mnt(&ad, mnt);
644 	return smk_curacc(smk_of_inode(dentry->d_inode), MAY_READ, &ad);
645 }
646 
647 /**
648  * smack_inode_setxattr - Smack check for setting xattrs
649  * @dentry: the object
650  * @name: name of the attribute
651  * @value: unused
652  * @size: unused
653  * @flags: unused
654  *
655  * This protects the Smack attribute explicitly.
656  *
657  * Returns 0 if access is permitted, an error code otherwise
658  */
659 static int smack_inode_setxattr(struct dentry *dentry, const char *name,
660 				const void *value, size_t size, int flags)
661 {
662 	struct smk_audit_info ad;
663 	int rc = 0;
664 
665 	if (strcmp(name, XATTR_NAME_SMACK) == 0 ||
666 	    strcmp(name, XATTR_NAME_SMACKIPIN) == 0 ||
667 	    strcmp(name, XATTR_NAME_SMACKIPOUT) == 0) {
668 		if (!capable(CAP_MAC_ADMIN))
669 			rc = -EPERM;
670 		/*
671 		 * check label validity here so import wont fail on
672 		 * post_setxattr
673 		 */
674 		if (size == 0 || size >= SMK_LABELLEN ||
675 		    smk_import(value, size) == NULL)
676 			rc = -EINVAL;
677 	} else
678 		rc = cap_inode_setxattr(dentry, name, value, size, flags);
679 
680 	smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_FS);
681 	smk_ad_setfield_u_fs_path_dentry(&ad, dentry);
682 
683 	if (rc == 0)
684 		rc = smk_curacc(smk_of_inode(dentry->d_inode), MAY_WRITE, &ad);
685 
686 	return rc;
687 }
688 
689 /**
690  * smack_inode_post_setxattr - Apply the Smack update approved above
691  * @dentry: object
692  * @name: attribute name
693  * @value: attribute value
694  * @size: attribute size
695  * @flags: unused
696  *
697  * Set the pointer in the inode blob to the entry found
698  * in the master label list.
699  */
700 static void smack_inode_post_setxattr(struct dentry *dentry, const char *name,
701 				      const void *value, size_t size, int flags)
702 {
703 	struct inode_smack *isp;
704 	char *nsp;
705 
706 	/*
707 	 * Not SMACK
708 	 */
709 	if (strcmp(name, XATTR_NAME_SMACK))
710 		return;
711 
712 	isp = dentry->d_inode->i_security;
713 
714 	/*
715 	 * No locking is done here. This is a pointer
716 	 * assignment.
717 	 */
718 	nsp = smk_import(value, size);
719 	if (nsp != NULL)
720 		isp->smk_inode = nsp;
721 	else
722 		isp->smk_inode = smack_known_invalid.smk_known;
723 
724 	return;
725 }
726 
727 /*
728  * smack_inode_getxattr - Smack check on getxattr
729  * @dentry: the object
730  * @name: unused
731  *
732  * Returns 0 if access is permitted, an error code otherwise
733  */
734 static int smack_inode_getxattr(struct dentry *dentry, const char *name)
735 {
736 	struct smk_audit_info ad;
737 
738 	smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_FS);
739 	smk_ad_setfield_u_fs_path_dentry(&ad, dentry);
740 
741 	return smk_curacc(smk_of_inode(dentry->d_inode), MAY_READ, &ad);
742 }
743 
744 /*
745  * smack_inode_removexattr - Smack check on removexattr
746  * @dentry: the object
747  * @name: name of the attribute
748  *
749  * Removing the Smack attribute requires CAP_MAC_ADMIN
750  *
751  * Returns 0 if access is permitted, an error code otherwise
752  */
753 static int smack_inode_removexattr(struct dentry *dentry, const char *name)
754 {
755 	struct smk_audit_info ad;
756 	int rc = 0;
757 
758 	if (strcmp(name, XATTR_NAME_SMACK) == 0 ||
759 	    strcmp(name, XATTR_NAME_SMACKIPIN) == 0 ||
760 	    strcmp(name, XATTR_NAME_SMACKIPOUT) == 0) {
761 		if (!capable(CAP_MAC_ADMIN))
762 			rc = -EPERM;
763 	} else
764 		rc = cap_inode_removexattr(dentry, name);
765 
766 	smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_FS);
767 	smk_ad_setfield_u_fs_path_dentry(&ad, dentry);
768 	if (rc == 0)
769 		rc = smk_curacc(smk_of_inode(dentry->d_inode), MAY_WRITE, &ad);
770 
771 	return rc;
772 }
773 
774 /**
775  * smack_inode_getsecurity - get smack xattrs
776  * @inode: the object
777  * @name: attribute name
778  * @buffer: where to put the result
779  * @alloc: unused
780  *
781  * Returns the size of the attribute or an error code
782  */
783 static int smack_inode_getsecurity(const struct inode *inode,
784 				   const char *name, void **buffer,
785 				   bool alloc)
786 {
787 	struct socket_smack *ssp;
788 	struct socket *sock;
789 	struct super_block *sbp;
790 	struct inode *ip = (struct inode *)inode;
791 	char *isp;
792 	int ilen;
793 	int rc = 0;
794 
795 	if (strcmp(name, XATTR_SMACK_SUFFIX) == 0) {
796 		isp = smk_of_inode(inode);
797 		ilen = strlen(isp) + 1;
798 		*buffer = isp;
799 		return ilen;
800 	}
801 
802 	/*
803 	 * The rest of the Smack xattrs are only on sockets.
804 	 */
805 	sbp = ip->i_sb;
806 	if (sbp->s_magic != SOCKFS_MAGIC)
807 		return -EOPNOTSUPP;
808 
809 	sock = SOCKET_I(ip);
810 	if (sock == NULL || sock->sk == NULL)
811 		return -EOPNOTSUPP;
812 
813 	ssp = sock->sk->sk_security;
814 
815 	if (strcmp(name, XATTR_SMACK_IPIN) == 0)
816 		isp = ssp->smk_in;
817 	else if (strcmp(name, XATTR_SMACK_IPOUT) == 0)
818 		isp = ssp->smk_out;
819 	else
820 		return -EOPNOTSUPP;
821 
822 	ilen = strlen(isp) + 1;
823 	if (rc == 0) {
824 		*buffer = isp;
825 		rc = ilen;
826 	}
827 
828 	return rc;
829 }
830 
831 
832 /**
833  * smack_inode_listsecurity - list the Smack attributes
834  * @inode: the object
835  * @buffer: where they go
836  * @buffer_size: size of buffer
837  *
838  * Returns 0 on success, -EINVAL otherwise
839  */
840 static int smack_inode_listsecurity(struct inode *inode, char *buffer,
841 				    size_t buffer_size)
842 {
843 	int len = strlen(XATTR_NAME_SMACK);
844 
845 	if (buffer != NULL && len <= buffer_size) {
846 		memcpy(buffer, XATTR_NAME_SMACK, len);
847 		return len;
848 	}
849 	return -EINVAL;
850 }
851 
852 /**
853  * smack_inode_getsecid - Extract inode's security id
854  * @inode: inode to extract the info from
855  * @secid: where result will be saved
856  */
857 static void smack_inode_getsecid(const struct inode *inode, u32 *secid)
858 {
859 	struct inode_smack *isp = inode->i_security;
860 
861 	*secid = smack_to_secid(isp->smk_inode);
862 }
863 
864 /*
865  * File Hooks
866  */
867 
868 /**
869  * smack_file_permission - Smack check on file operations
870  * @file: unused
871  * @mask: unused
872  *
873  * Returns 0
874  *
875  * Should access checks be done on each read or write?
876  * UNICOS and SELinux say yes.
877  * Trusted Solaris, Trusted Irix, and just about everyone else says no.
878  *
879  * I'll say no for now. Smack does not do the frequent
880  * label changing that SELinux does.
881  */
882 static int smack_file_permission(struct file *file, int mask)
883 {
884 	return 0;
885 }
886 
887 /**
888  * smack_file_alloc_security - assign a file security blob
889  * @file: the object
890  *
891  * The security blob for a file is a pointer to the master
892  * label list, so no allocation is done.
893  *
894  * Returns 0
895  */
896 static int smack_file_alloc_security(struct file *file)
897 {
898 	file->f_security = current_security();
899 	return 0;
900 }
901 
902 /**
903  * smack_file_free_security - clear a file security blob
904  * @file: the object
905  *
906  * The security blob for a file is a pointer to the master
907  * label list, so no memory is freed.
908  */
909 static void smack_file_free_security(struct file *file)
910 {
911 	file->f_security = NULL;
912 }
913 
914 /**
915  * smack_file_ioctl - Smack check on ioctls
916  * @file: the object
917  * @cmd: what to do
918  * @arg: unused
919  *
920  * Relies heavily on the correct use of the ioctl command conventions.
921  *
922  * Returns 0 if allowed, error code otherwise
923  */
924 static int smack_file_ioctl(struct file *file, unsigned int cmd,
925 			    unsigned long arg)
926 {
927 	int rc = 0;
928 	struct smk_audit_info ad;
929 
930 	smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_FS);
931 	smk_ad_setfield_u_fs_path(&ad, file->f_path);
932 
933 	if (_IOC_DIR(cmd) & _IOC_WRITE)
934 		rc = smk_curacc(file->f_security, MAY_WRITE, &ad);
935 
936 	if (rc == 0 && (_IOC_DIR(cmd) & _IOC_READ))
937 		rc = smk_curacc(file->f_security, MAY_READ, &ad);
938 
939 	return rc;
940 }
941 
942 /**
943  * smack_file_lock - Smack check on file locking
944  * @file: the object
945  * @cmd: unused
946  *
947  * Returns 0 if current has write access, error code otherwise
948  */
949 static int smack_file_lock(struct file *file, unsigned int cmd)
950 {
951 	struct smk_audit_info ad;
952 
953 	smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_FS);
954 	smk_ad_setfield_u_fs_path_dentry(&ad, file->f_path.dentry);
955 	return smk_curacc(file->f_security, MAY_WRITE, &ad);
956 }
957 
958 /**
959  * smack_file_fcntl - Smack check on fcntl
960  * @file: the object
961  * @cmd: what action to check
962  * @arg: unused
963  *
964  * Returns 0 if current has access, error code otherwise
965  */
966 static int smack_file_fcntl(struct file *file, unsigned int cmd,
967 			    unsigned long arg)
968 {
969 	struct smk_audit_info ad;
970 	int rc;
971 
972 	smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_FS);
973 	smk_ad_setfield_u_fs_path(&ad, file->f_path);
974 
975 	switch (cmd) {
976 	case F_DUPFD:
977 	case F_GETFD:
978 	case F_GETFL:
979 	case F_GETLK:
980 	case F_GETOWN:
981 	case F_GETSIG:
982 		rc = smk_curacc(file->f_security, MAY_READ, &ad);
983 		break;
984 	case F_SETFD:
985 	case F_SETFL:
986 	case F_SETLK:
987 	case F_SETLKW:
988 	case F_SETOWN:
989 	case F_SETSIG:
990 		rc = smk_curacc(file->f_security, MAY_WRITE, &ad);
991 		break;
992 	default:
993 		rc = smk_curacc(file->f_security, MAY_READWRITE, &ad);
994 	}
995 
996 	return rc;
997 }
998 
999 /**
1000  * smack_file_set_fowner - set the file security blob value
1001  * @file: object in question
1002  *
1003  * Returns 0
1004  * Further research may be required on this one.
1005  */
1006 static int smack_file_set_fowner(struct file *file)
1007 {
1008 	file->f_security = current_security();
1009 	return 0;
1010 }
1011 
1012 /**
1013  * smack_file_send_sigiotask - Smack on sigio
1014  * @tsk: The target task
1015  * @fown: the object the signal come from
1016  * @signum: unused
1017  *
1018  * Allow a privileged task to get signals even if it shouldn't
1019  *
1020  * Returns 0 if a subject with the object's smack could
1021  * write to the task, an error code otherwise.
1022  */
1023 static int smack_file_send_sigiotask(struct task_struct *tsk,
1024 				     struct fown_struct *fown, int signum)
1025 {
1026 	struct file *file;
1027 	int rc;
1028 	char *tsp = tsk->cred->security;
1029 	struct smk_audit_info ad;
1030 
1031 	/*
1032 	 * struct fown_struct is never outside the context of a struct file
1033 	 */
1034 	file = container_of(fown, struct file, f_owner);
1035 	/* we don't log here as rc can be overriden */
1036 	rc = smk_access(file->f_security, tsp, MAY_WRITE, NULL);
1037 	if (rc != 0 && has_capability(tsk, CAP_MAC_OVERRIDE))
1038 		rc = 0;
1039 
1040 	smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_TASK);
1041 	smk_ad_setfield_u_tsk(&ad, tsk);
1042 	smack_log(file->f_security, tsp, MAY_WRITE, rc, &ad);
1043 	return rc;
1044 }
1045 
1046 /**
1047  * smack_file_receive - Smack file receive check
1048  * @file: the object
1049  *
1050  * Returns 0 if current has access, error code otherwise
1051  */
1052 static int smack_file_receive(struct file *file)
1053 {
1054 	int may = 0;
1055 	struct smk_audit_info ad;
1056 
1057 	smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_TASK);
1058 	smk_ad_setfield_u_fs_path(&ad, file->f_path);
1059 	/*
1060 	 * This code relies on bitmasks.
1061 	 */
1062 	if (file->f_mode & FMODE_READ)
1063 		may = MAY_READ;
1064 	if (file->f_mode & FMODE_WRITE)
1065 		may |= MAY_WRITE;
1066 
1067 	return smk_curacc(file->f_security, may, &ad);
1068 }
1069 
1070 /*
1071  * Task hooks
1072  */
1073 
1074 /**
1075  * smack_cred_alloc_blank - "allocate" blank task-level security credentials
1076  * @new: the new credentials
1077  * @gfp: the atomicity of any memory allocations
1078  *
1079  * Prepare a blank set of credentials for modification.  This must allocate all
1080  * the memory the LSM module might require such that cred_transfer() can
1081  * complete without error.
1082  */
1083 static int smack_cred_alloc_blank(struct cred *cred, gfp_t gfp)
1084 {
1085 	cred->security = NULL;
1086 	return 0;
1087 }
1088 
1089 
1090 /**
1091  * smack_cred_free - "free" task-level security credentials
1092  * @cred: the credentials in question
1093  *
1094  * Smack isn't using copies of blobs. Everyone
1095  * points to an immutable list. The blobs never go away.
1096  * There is no leak here.
1097  */
1098 static void smack_cred_free(struct cred *cred)
1099 {
1100 	cred->security = NULL;
1101 }
1102 
1103 /**
1104  * smack_cred_prepare - prepare new set of credentials for modification
1105  * @new: the new credentials
1106  * @old: the original credentials
1107  * @gfp: the atomicity of any memory allocations
1108  *
1109  * Prepare a new set of credentials for modification.
1110  */
1111 static int smack_cred_prepare(struct cred *new, const struct cred *old,
1112 			      gfp_t gfp)
1113 {
1114 	new->security = old->security;
1115 	return 0;
1116 }
1117 
1118 /**
1119  * smack_cred_transfer - Transfer the old credentials to the new credentials
1120  * @new: the new credentials
1121  * @old: the original credentials
1122  *
1123  * Fill in a set of blank credentials from another set of credentials.
1124  */
1125 static void smack_cred_transfer(struct cred *new, const struct cred *old)
1126 {
1127 	new->security = old->security;
1128 }
1129 
1130 /**
1131  * smack_kernel_act_as - Set the subjective context in a set of credentials
1132  * @new: points to the set of credentials to be modified.
1133  * @secid: specifies the security ID to be set
1134  *
1135  * Set the security data for a kernel service.
1136  */
1137 static int smack_kernel_act_as(struct cred *new, u32 secid)
1138 {
1139 	char *smack = smack_from_secid(secid);
1140 
1141 	if (smack == NULL)
1142 		return -EINVAL;
1143 
1144 	new->security = smack;
1145 	return 0;
1146 }
1147 
1148 /**
1149  * smack_kernel_create_files_as - Set the file creation label in a set of creds
1150  * @new: points to the set of credentials to be modified
1151  * @inode: points to the inode to use as a reference
1152  *
1153  * Set the file creation context in a set of credentials to the same
1154  * as the objective context of the specified inode
1155  */
1156 static int smack_kernel_create_files_as(struct cred *new,
1157 					struct inode *inode)
1158 {
1159 	struct inode_smack *isp = inode->i_security;
1160 
1161 	new->security = isp->smk_inode;
1162 	return 0;
1163 }
1164 
1165 /**
1166  * smk_curacc_on_task - helper to log task related access
1167  * @p: the task object
1168  * @access : the access requested
1169  *
1170  * Return 0 if access is permitted
1171  */
1172 static int smk_curacc_on_task(struct task_struct *p, int access)
1173 {
1174 	struct smk_audit_info ad;
1175 
1176 	smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_TASK);
1177 	smk_ad_setfield_u_tsk(&ad, p);
1178 	return smk_curacc(task_security(p), access, &ad);
1179 }
1180 
1181 /**
1182  * smack_task_setpgid - Smack check on setting pgid
1183  * @p: the task object
1184  * @pgid: unused
1185  *
1186  * Return 0 if write access is permitted
1187  */
1188 static int smack_task_setpgid(struct task_struct *p, pid_t pgid)
1189 {
1190 	return smk_curacc_on_task(p, MAY_WRITE);
1191 }
1192 
1193 /**
1194  * smack_task_getpgid - Smack access check for getpgid
1195  * @p: the object task
1196  *
1197  * Returns 0 if current can read the object task, error code otherwise
1198  */
1199 static int smack_task_getpgid(struct task_struct *p)
1200 {
1201 	return smk_curacc_on_task(p, MAY_READ);
1202 }
1203 
1204 /**
1205  * smack_task_getsid - Smack access check for getsid
1206  * @p: the object task
1207  *
1208  * Returns 0 if current can read the object task, error code otherwise
1209  */
1210 static int smack_task_getsid(struct task_struct *p)
1211 {
1212 	return smk_curacc_on_task(p, MAY_READ);
1213 }
1214 
1215 /**
1216  * smack_task_getsecid - get the secid of the task
1217  * @p: the object task
1218  * @secid: where to put the result
1219  *
1220  * Sets the secid to contain a u32 version of the smack label.
1221  */
1222 static void smack_task_getsecid(struct task_struct *p, u32 *secid)
1223 {
1224 	*secid = smack_to_secid(task_security(p));
1225 }
1226 
1227 /**
1228  * smack_task_setnice - Smack check on setting nice
1229  * @p: the task object
1230  * @nice: unused
1231  *
1232  * Return 0 if write access is permitted
1233  */
1234 static int smack_task_setnice(struct task_struct *p, int nice)
1235 {
1236 	int rc;
1237 
1238 	rc = cap_task_setnice(p, nice);
1239 	if (rc == 0)
1240 		rc = smk_curacc_on_task(p, MAY_WRITE);
1241 	return rc;
1242 }
1243 
1244 /**
1245  * smack_task_setioprio - Smack check on setting ioprio
1246  * @p: the task object
1247  * @ioprio: unused
1248  *
1249  * Return 0 if write access is permitted
1250  */
1251 static int smack_task_setioprio(struct task_struct *p, int ioprio)
1252 {
1253 	int rc;
1254 
1255 	rc = cap_task_setioprio(p, ioprio);
1256 	if (rc == 0)
1257 		rc = smk_curacc_on_task(p, MAY_WRITE);
1258 	return rc;
1259 }
1260 
1261 /**
1262  * smack_task_getioprio - Smack check on reading ioprio
1263  * @p: the task object
1264  *
1265  * Return 0 if read access is permitted
1266  */
1267 static int smack_task_getioprio(struct task_struct *p)
1268 {
1269 	return smk_curacc_on_task(p, MAY_READ);
1270 }
1271 
1272 /**
1273  * smack_task_setscheduler - Smack check on setting scheduler
1274  * @p: the task object
1275  * @policy: unused
1276  * @lp: unused
1277  *
1278  * Return 0 if read access is permitted
1279  */
1280 static int smack_task_setscheduler(struct task_struct *p)
1281 {
1282 	int rc;
1283 
1284 	rc = cap_task_setscheduler(p);
1285 	if (rc == 0)
1286 		rc = smk_curacc_on_task(p, MAY_WRITE);
1287 	return rc;
1288 }
1289 
1290 /**
1291  * smack_task_getscheduler - Smack check on reading scheduler
1292  * @p: the task object
1293  *
1294  * Return 0 if read access is permitted
1295  */
1296 static int smack_task_getscheduler(struct task_struct *p)
1297 {
1298 	return smk_curacc_on_task(p, MAY_READ);
1299 }
1300 
1301 /**
1302  * smack_task_movememory - Smack check on moving memory
1303  * @p: the task object
1304  *
1305  * Return 0 if write access is permitted
1306  */
1307 static int smack_task_movememory(struct task_struct *p)
1308 {
1309 	return smk_curacc_on_task(p, MAY_WRITE);
1310 }
1311 
1312 /**
1313  * smack_task_kill - Smack check on signal delivery
1314  * @p: the task object
1315  * @info: unused
1316  * @sig: unused
1317  * @secid: identifies the smack to use in lieu of current's
1318  *
1319  * Return 0 if write access is permitted
1320  *
1321  * The secid behavior is an artifact of an SELinux hack
1322  * in the USB code. Someday it may go away.
1323  */
1324 static int smack_task_kill(struct task_struct *p, struct siginfo *info,
1325 			   int sig, u32 secid)
1326 {
1327 	struct smk_audit_info ad;
1328 
1329 	smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_TASK);
1330 	smk_ad_setfield_u_tsk(&ad, p);
1331 	/*
1332 	 * Sending a signal requires that the sender
1333 	 * can write the receiver.
1334 	 */
1335 	if (secid == 0)
1336 		return smk_curacc(task_security(p), MAY_WRITE, &ad);
1337 	/*
1338 	 * If the secid isn't 0 we're dealing with some USB IO
1339 	 * specific behavior. This is not clean. For one thing
1340 	 * we can't take privilege into account.
1341 	 */
1342 	return smk_access(smack_from_secid(secid), task_security(p),
1343 			  MAY_WRITE, &ad);
1344 }
1345 
1346 /**
1347  * smack_task_wait - Smack access check for waiting
1348  * @p: task to wait for
1349  *
1350  * Returns 0 if current can wait for p, error code otherwise
1351  */
1352 static int smack_task_wait(struct task_struct *p)
1353 {
1354 	struct smk_audit_info ad;
1355 	char *sp = current_security();
1356 	char *tsp = task_security(p);
1357 	int rc;
1358 
1359 	/* we don't log here, we can be overriden */
1360 	rc = smk_access(sp, tsp, MAY_WRITE, NULL);
1361 	if (rc == 0)
1362 		goto out_log;
1363 
1364 	/*
1365 	 * Allow the operation to succeed if either task
1366 	 * has privilege to perform operations that might
1367 	 * account for the smack labels having gotten to
1368 	 * be different in the first place.
1369 	 *
1370 	 * This breaks the strict subject/object access
1371 	 * control ideal, taking the object's privilege
1372 	 * state into account in the decision as well as
1373 	 * the smack value.
1374 	 */
1375 	if (capable(CAP_MAC_OVERRIDE) || has_capability(p, CAP_MAC_OVERRIDE))
1376 		rc = 0;
1377 	/* we log only if we didn't get overriden */
1378  out_log:
1379 	smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_TASK);
1380 	smk_ad_setfield_u_tsk(&ad, p);
1381 	smack_log(sp, tsp, MAY_WRITE, rc, &ad);
1382 	return rc;
1383 }
1384 
1385 /**
1386  * smack_task_to_inode - copy task smack into the inode blob
1387  * @p: task to copy from
1388  * @inode: inode to copy to
1389  *
1390  * Sets the smack pointer in the inode security blob
1391  */
1392 static void smack_task_to_inode(struct task_struct *p, struct inode *inode)
1393 {
1394 	struct inode_smack *isp = inode->i_security;
1395 	isp->smk_inode = task_security(p);
1396 }
1397 
1398 /*
1399  * Socket hooks.
1400  */
1401 
1402 /**
1403  * smack_sk_alloc_security - Allocate a socket blob
1404  * @sk: the socket
1405  * @family: unused
1406  * @gfp_flags: memory allocation flags
1407  *
1408  * Assign Smack pointers to current
1409  *
1410  * Returns 0 on success, -ENOMEM is there's no memory
1411  */
1412 static int smack_sk_alloc_security(struct sock *sk, int family, gfp_t gfp_flags)
1413 {
1414 	char *csp = current_security();
1415 	struct socket_smack *ssp;
1416 
1417 	ssp = kzalloc(sizeof(struct socket_smack), gfp_flags);
1418 	if (ssp == NULL)
1419 		return -ENOMEM;
1420 
1421 	ssp->smk_in = csp;
1422 	ssp->smk_out = csp;
1423 	ssp->smk_packet[0] = '\0';
1424 
1425 	sk->sk_security = ssp;
1426 
1427 	return 0;
1428 }
1429 
1430 /**
1431  * smack_sk_free_security - Free a socket blob
1432  * @sk: the socket
1433  *
1434  * Clears the blob pointer
1435  */
1436 static void smack_sk_free_security(struct sock *sk)
1437 {
1438 	kfree(sk->sk_security);
1439 }
1440 
1441 /**
1442 * smack_host_label - check host based restrictions
1443 * @sip: the object end
1444 *
1445 * looks for host based access restrictions
1446 *
1447 * This version will only be appropriate for really small sets of single label
1448 * hosts.  The caller is responsible for ensuring that the RCU read lock is
1449 * taken before calling this function.
1450 *
1451 * Returns the label of the far end or NULL if it's not special.
1452 */
1453 static char *smack_host_label(struct sockaddr_in *sip)
1454 {
1455 	struct smk_netlbladdr *snp;
1456 	struct in_addr *siap = &sip->sin_addr;
1457 
1458 	if (siap->s_addr == 0)
1459 		return NULL;
1460 
1461 	list_for_each_entry_rcu(snp, &smk_netlbladdr_list, list)
1462 		/*
1463 		* we break after finding the first match because
1464 		* the list is sorted from longest to shortest mask
1465 		* so we have found the most specific match
1466 		*/
1467 		if ((&snp->smk_host.sin_addr)->s_addr ==
1468 		    (siap->s_addr & (&snp->smk_mask)->s_addr)) {
1469 			/* we have found the special CIPSO option */
1470 			if (snp->smk_label == smack_cipso_option)
1471 				return NULL;
1472 			return snp->smk_label;
1473 		}
1474 
1475 	return NULL;
1476 }
1477 
1478 /**
1479  * smack_set_catset - convert a capset to netlabel mls categories
1480  * @catset: the Smack categories
1481  * @sap: where to put the netlabel categories
1482  *
1483  * Allocates and fills attr.mls.cat
1484  */
1485 static void smack_set_catset(char *catset, struct netlbl_lsm_secattr *sap)
1486 {
1487 	unsigned char *cp;
1488 	unsigned char m;
1489 	int cat;
1490 	int rc;
1491 	int byte;
1492 
1493 	if (!catset)
1494 		return;
1495 
1496 	sap->flags |= NETLBL_SECATTR_MLS_CAT;
1497 	sap->attr.mls.cat = netlbl_secattr_catmap_alloc(GFP_ATOMIC);
1498 	sap->attr.mls.cat->startbit = 0;
1499 
1500 	for (cat = 1, cp = catset, byte = 0; byte < SMK_LABELLEN; cp++, byte++)
1501 		for (m = 0x80; m != 0; m >>= 1, cat++) {
1502 			if ((m & *cp) == 0)
1503 				continue;
1504 			rc = netlbl_secattr_catmap_setbit(sap->attr.mls.cat,
1505 							  cat, GFP_ATOMIC);
1506 		}
1507 }
1508 
1509 /**
1510  * smack_to_secattr - fill a secattr from a smack value
1511  * @smack: the smack value
1512  * @nlsp: where the result goes
1513  *
1514  * Casey says that CIPSO is good enough for now.
1515  * It can be used to effect.
1516  * It can also be abused to effect when necessary.
1517  * Appologies to the TSIG group in general and GW in particular.
1518  */
1519 static void smack_to_secattr(char *smack, struct netlbl_lsm_secattr *nlsp)
1520 {
1521 	struct smack_cipso cipso;
1522 	int rc;
1523 
1524 	nlsp->domain = smack;
1525 	nlsp->flags = NETLBL_SECATTR_DOMAIN | NETLBL_SECATTR_MLS_LVL;
1526 
1527 	rc = smack_to_cipso(smack, &cipso);
1528 	if (rc == 0) {
1529 		nlsp->attr.mls.lvl = cipso.smk_level;
1530 		smack_set_catset(cipso.smk_catset, nlsp);
1531 	} else {
1532 		nlsp->attr.mls.lvl = smack_cipso_direct;
1533 		smack_set_catset(smack, nlsp);
1534 	}
1535 }
1536 
1537 /**
1538  * smack_netlabel - Set the secattr on a socket
1539  * @sk: the socket
1540  * @labeled: socket label scheme
1541  *
1542  * Convert the outbound smack value (smk_out) to a
1543  * secattr and attach it to the socket.
1544  *
1545  * Returns 0 on success or an error code
1546  */
1547 static int smack_netlabel(struct sock *sk, int labeled)
1548 {
1549 	struct socket_smack *ssp = sk->sk_security;
1550 	struct netlbl_lsm_secattr secattr;
1551 	int rc = 0;
1552 
1553 	/*
1554 	 * Usually the netlabel code will handle changing the
1555 	 * packet labeling based on the label.
1556 	 * The case of a single label host is different, because
1557 	 * a single label host should never get a labeled packet
1558 	 * even though the label is usually associated with a packet
1559 	 * label.
1560 	 */
1561 	local_bh_disable();
1562 	bh_lock_sock_nested(sk);
1563 
1564 	if (ssp->smk_out == smack_net_ambient ||
1565 	    labeled == SMACK_UNLABELED_SOCKET)
1566 		netlbl_sock_delattr(sk);
1567 	else {
1568 		netlbl_secattr_init(&secattr);
1569 		smack_to_secattr(ssp->smk_out, &secattr);
1570 		rc = netlbl_sock_setattr(sk, sk->sk_family, &secattr);
1571 		netlbl_secattr_destroy(&secattr);
1572 	}
1573 
1574 	bh_unlock_sock(sk);
1575 	local_bh_enable();
1576 
1577 	return rc;
1578 }
1579 
1580 /**
1581  * smack_netlbel_send - Set the secattr on a socket and perform access checks
1582  * @sk: the socket
1583  * @sap: the destination address
1584  *
1585  * Set the correct secattr for the given socket based on the destination
1586  * address and perform any outbound access checks needed.
1587  *
1588  * Returns 0 on success or an error code.
1589  *
1590  */
1591 static int smack_netlabel_send(struct sock *sk, struct sockaddr_in *sap)
1592 {
1593 	int rc;
1594 	int sk_lbl;
1595 	char *hostsp;
1596 	struct socket_smack *ssp = sk->sk_security;
1597 	struct smk_audit_info ad;
1598 
1599 	rcu_read_lock();
1600 	hostsp = smack_host_label(sap);
1601 	if (hostsp != NULL) {
1602 		sk_lbl = SMACK_UNLABELED_SOCKET;
1603 #ifdef CONFIG_AUDIT
1604 		smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_NET);
1605 		ad.a.u.net.family = sap->sin_family;
1606 		ad.a.u.net.dport = sap->sin_port;
1607 		ad.a.u.net.v4info.daddr = sap->sin_addr.s_addr;
1608 #endif
1609 		rc = smk_access(ssp->smk_out, hostsp, MAY_WRITE, &ad);
1610 	} else {
1611 		sk_lbl = SMACK_CIPSO_SOCKET;
1612 		rc = 0;
1613 	}
1614 	rcu_read_unlock();
1615 	if (rc != 0)
1616 		return rc;
1617 
1618 	return smack_netlabel(sk, sk_lbl);
1619 }
1620 
1621 /**
1622  * smack_inode_setsecurity - set smack xattrs
1623  * @inode: the object
1624  * @name: attribute name
1625  * @value: attribute value
1626  * @size: size of the attribute
1627  * @flags: unused
1628  *
1629  * Sets the named attribute in the appropriate blob
1630  *
1631  * Returns 0 on success, or an error code
1632  */
1633 static int smack_inode_setsecurity(struct inode *inode, const char *name,
1634 				   const void *value, size_t size, int flags)
1635 {
1636 	char *sp;
1637 	struct inode_smack *nsp = inode->i_security;
1638 	struct socket_smack *ssp;
1639 	struct socket *sock;
1640 	int rc = 0;
1641 
1642 	if (value == NULL || size > SMK_LABELLEN || size == 0)
1643 		return -EACCES;
1644 
1645 	sp = smk_import(value, size);
1646 	if (sp == NULL)
1647 		return -EINVAL;
1648 
1649 	if (strcmp(name, XATTR_SMACK_SUFFIX) == 0) {
1650 		nsp->smk_inode = sp;
1651 		nsp->smk_flags |= SMK_INODE_INSTANT;
1652 		return 0;
1653 	}
1654 	/*
1655 	 * The rest of the Smack xattrs are only on sockets.
1656 	 */
1657 	if (inode->i_sb->s_magic != SOCKFS_MAGIC)
1658 		return -EOPNOTSUPP;
1659 
1660 	sock = SOCKET_I(inode);
1661 	if (sock == NULL || sock->sk == NULL)
1662 		return -EOPNOTSUPP;
1663 
1664 	ssp = sock->sk->sk_security;
1665 
1666 	if (strcmp(name, XATTR_SMACK_IPIN) == 0)
1667 		ssp->smk_in = sp;
1668 	else if (strcmp(name, XATTR_SMACK_IPOUT) == 0) {
1669 		ssp->smk_out = sp;
1670 		rc = smack_netlabel(sock->sk, SMACK_CIPSO_SOCKET);
1671 		if (rc != 0)
1672 			printk(KERN_WARNING "Smack: \"%s\" netlbl error %d.\n",
1673 			       __func__, -rc);
1674 	} else
1675 		return -EOPNOTSUPP;
1676 
1677 	return 0;
1678 }
1679 
1680 /**
1681  * smack_socket_post_create - finish socket setup
1682  * @sock: the socket
1683  * @family: protocol family
1684  * @type: unused
1685  * @protocol: unused
1686  * @kern: unused
1687  *
1688  * Sets the netlabel information on the socket
1689  *
1690  * Returns 0 on success, and error code otherwise
1691  */
1692 static int smack_socket_post_create(struct socket *sock, int family,
1693 				    int type, int protocol, int kern)
1694 {
1695 	if (family != PF_INET || sock->sk == NULL)
1696 		return 0;
1697 	/*
1698 	 * Set the outbound netlbl.
1699 	 */
1700 	return smack_netlabel(sock->sk, SMACK_CIPSO_SOCKET);
1701 }
1702 
1703 /**
1704  * smack_socket_connect - connect access check
1705  * @sock: the socket
1706  * @sap: the other end
1707  * @addrlen: size of sap
1708  *
1709  * Verifies that a connection may be possible
1710  *
1711  * Returns 0 on success, and error code otherwise
1712  */
1713 static int smack_socket_connect(struct socket *sock, struct sockaddr *sap,
1714 				int addrlen)
1715 {
1716 	if (sock->sk == NULL || sock->sk->sk_family != PF_INET)
1717 		return 0;
1718 	if (addrlen < sizeof(struct sockaddr_in))
1719 		return -EINVAL;
1720 
1721 	return smack_netlabel_send(sock->sk, (struct sockaddr_in *)sap);
1722 }
1723 
1724 /**
1725  * smack_flags_to_may - convert S_ to MAY_ values
1726  * @flags: the S_ value
1727  *
1728  * Returns the equivalent MAY_ value
1729  */
1730 static int smack_flags_to_may(int flags)
1731 {
1732 	int may = 0;
1733 
1734 	if (flags & S_IRUGO)
1735 		may |= MAY_READ;
1736 	if (flags & S_IWUGO)
1737 		may |= MAY_WRITE;
1738 	if (flags & S_IXUGO)
1739 		may |= MAY_EXEC;
1740 
1741 	return may;
1742 }
1743 
1744 /**
1745  * smack_msg_msg_alloc_security - Set the security blob for msg_msg
1746  * @msg: the object
1747  *
1748  * Returns 0
1749  */
1750 static int smack_msg_msg_alloc_security(struct msg_msg *msg)
1751 {
1752 	msg->security = current_security();
1753 	return 0;
1754 }
1755 
1756 /**
1757  * smack_msg_msg_free_security - Clear the security blob for msg_msg
1758  * @msg: the object
1759  *
1760  * Clears the blob pointer
1761  */
1762 static void smack_msg_msg_free_security(struct msg_msg *msg)
1763 {
1764 	msg->security = NULL;
1765 }
1766 
1767 /**
1768  * smack_of_shm - the smack pointer for the shm
1769  * @shp: the object
1770  *
1771  * Returns a pointer to the smack value
1772  */
1773 static char *smack_of_shm(struct shmid_kernel *shp)
1774 {
1775 	return (char *)shp->shm_perm.security;
1776 }
1777 
1778 /**
1779  * smack_shm_alloc_security - Set the security blob for shm
1780  * @shp: the object
1781  *
1782  * Returns 0
1783  */
1784 static int smack_shm_alloc_security(struct shmid_kernel *shp)
1785 {
1786 	struct kern_ipc_perm *isp = &shp->shm_perm;
1787 
1788 	isp->security = current_security();
1789 	return 0;
1790 }
1791 
1792 /**
1793  * smack_shm_free_security - Clear the security blob for shm
1794  * @shp: the object
1795  *
1796  * Clears the blob pointer
1797  */
1798 static void smack_shm_free_security(struct shmid_kernel *shp)
1799 {
1800 	struct kern_ipc_perm *isp = &shp->shm_perm;
1801 
1802 	isp->security = NULL;
1803 }
1804 
1805 /**
1806  * smk_curacc_shm : check if current has access on shm
1807  * @shp : the object
1808  * @access : access requested
1809  *
1810  * Returns 0 if current has the requested access, error code otherwise
1811  */
1812 static int smk_curacc_shm(struct shmid_kernel *shp, int access)
1813 {
1814 	char *ssp = smack_of_shm(shp);
1815 	struct smk_audit_info ad;
1816 
1817 #ifdef CONFIG_AUDIT
1818 	smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_IPC);
1819 	ad.a.u.ipc_id = shp->shm_perm.id;
1820 #endif
1821 	return smk_curacc(ssp, access, &ad);
1822 }
1823 
1824 /**
1825  * smack_shm_associate - Smack access check for shm
1826  * @shp: the object
1827  * @shmflg: access requested
1828  *
1829  * Returns 0 if current has the requested access, error code otherwise
1830  */
1831 static int smack_shm_associate(struct shmid_kernel *shp, int shmflg)
1832 {
1833 	int may;
1834 
1835 	may = smack_flags_to_may(shmflg);
1836 	return smk_curacc_shm(shp, may);
1837 }
1838 
1839 /**
1840  * smack_shm_shmctl - Smack access check for shm
1841  * @shp: the object
1842  * @cmd: what it wants to do
1843  *
1844  * Returns 0 if current has the requested access, error code otherwise
1845  */
1846 static int smack_shm_shmctl(struct shmid_kernel *shp, int cmd)
1847 {
1848 	int may;
1849 
1850 	switch (cmd) {
1851 	case IPC_STAT:
1852 	case SHM_STAT:
1853 		may = MAY_READ;
1854 		break;
1855 	case IPC_SET:
1856 	case SHM_LOCK:
1857 	case SHM_UNLOCK:
1858 	case IPC_RMID:
1859 		may = MAY_READWRITE;
1860 		break;
1861 	case IPC_INFO:
1862 	case SHM_INFO:
1863 		/*
1864 		 * System level information.
1865 		 */
1866 		return 0;
1867 	default:
1868 		return -EINVAL;
1869 	}
1870 	return smk_curacc_shm(shp, may);
1871 }
1872 
1873 /**
1874  * smack_shm_shmat - Smack access for shmat
1875  * @shp: the object
1876  * @shmaddr: unused
1877  * @shmflg: access requested
1878  *
1879  * Returns 0 if current has the requested access, error code otherwise
1880  */
1881 static int smack_shm_shmat(struct shmid_kernel *shp, char __user *shmaddr,
1882 			   int shmflg)
1883 {
1884 	int may;
1885 
1886 	may = smack_flags_to_may(shmflg);
1887 	return smk_curacc_shm(shp, may);
1888 }
1889 
1890 /**
1891  * smack_of_sem - the smack pointer for the sem
1892  * @sma: the object
1893  *
1894  * Returns a pointer to the smack value
1895  */
1896 static char *smack_of_sem(struct sem_array *sma)
1897 {
1898 	return (char *)sma->sem_perm.security;
1899 }
1900 
1901 /**
1902  * smack_sem_alloc_security - Set the security blob for sem
1903  * @sma: the object
1904  *
1905  * Returns 0
1906  */
1907 static int smack_sem_alloc_security(struct sem_array *sma)
1908 {
1909 	struct kern_ipc_perm *isp = &sma->sem_perm;
1910 
1911 	isp->security = current_security();
1912 	return 0;
1913 }
1914 
1915 /**
1916  * smack_sem_free_security - Clear the security blob for sem
1917  * @sma: the object
1918  *
1919  * Clears the blob pointer
1920  */
1921 static void smack_sem_free_security(struct sem_array *sma)
1922 {
1923 	struct kern_ipc_perm *isp = &sma->sem_perm;
1924 
1925 	isp->security = NULL;
1926 }
1927 
1928 /**
1929  * smk_curacc_sem : check if current has access on sem
1930  * @sma : the object
1931  * @access : access requested
1932  *
1933  * Returns 0 if current has the requested access, error code otherwise
1934  */
1935 static int smk_curacc_sem(struct sem_array *sma, int access)
1936 {
1937 	char *ssp = smack_of_sem(sma);
1938 	struct smk_audit_info ad;
1939 
1940 #ifdef CONFIG_AUDIT
1941 	smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_IPC);
1942 	ad.a.u.ipc_id = sma->sem_perm.id;
1943 #endif
1944 	return smk_curacc(ssp, access, &ad);
1945 }
1946 
1947 /**
1948  * smack_sem_associate - Smack access check for sem
1949  * @sma: the object
1950  * @semflg: access requested
1951  *
1952  * Returns 0 if current has the requested access, error code otherwise
1953  */
1954 static int smack_sem_associate(struct sem_array *sma, int semflg)
1955 {
1956 	int may;
1957 
1958 	may = smack_flags_to_may(semflg);
1959 	return smk_curacc_sem(sma, may);
1960 }
1961 
1962 /**
1963  * smack_sem_shmctl - Smack access check for sem
1964  * @sma: the object
1965  * @cmd: what it wants to do
1966  *
1967  * Returns 0 if current has the requested access, error code otherwise
1968  */
1969 static int smack_sem_semctl(struct sem_array *sma, int cmd)
1970 {
1971 	int may;
1972 
1973 	switch (cmd) {
1974 	case GETPID:
1975 	case GETNCNT:
1976 	case GETZCNT:
1977 	case GETVAL:
1978 	case GETALL:
1979 	case IPC_STAT:
1980 	case SEM_STAT:
1981 		may = MAY_READ;
1982 		break;
1983 	case SETVAL:
1984 	case SETALL:
1985 	case IPC_RMID:
1986 	case IPC_SET:
1987 		may = MAY_READWRITE;
1988 		break;
1989 	case IPC_INFO:
1990 	case SEM_INFO:
1991 		/*
1992 		 * System level information
1993 		 */
1994 		return 0;
1995 	default:
1996 		return -EINVAL;
1997 	}
1998 
1999 	return smk_curacc_sem(sma, may);
2000 }
2001 
2002 /**
2003  * smack_sem_semop - Smack checks of semaphore operations
2004  * @sma: the object
2005  * @sops: unused
2006  * @nsops: unused
2007  * @alter: unused
2008  *
2009  * Treated as read and write in all cases.
2010  *
2011  * Returns 0 if access is allowed, error code otherwise
2012  */
2013 static int smack_sem_semop(struct sem_array *sma, struct sembuf *sops,
2014 			   unsigned nsops, int alter)
2015 {
2016 	return smk_curacc_sem(sma, MAY_READWRITE);
2017 }
2018 
2019 /**
2020  * smack_msg_alloc_security - Set the security blob for msg
2021  * @msq: the object
2022  *
2023  * Returns 0
2024  */
2025 static int smack_msg_queue_alloc_security(struct msg_queue *msq)
2026 {
2027 	struct kern_ipc_perm *kisp = &msq->q_perm;
2028 
2029 	kisp->security = current_security();
2030 	return 0;
2031 }
2032 
2033 /**
2034  * smack_msg_free_security - Clear the security blob for msg
2035  * @msq: the object
2036  *
2037  * Clears the blob pointer
2038  */
2039 static void smack_msg_queue_free_security(struct msg_queue *msq)
2040 {
2041 	struct kern_ipc_perm *kisp = &msq->q_perm;
2042 
2043 	kisp->security = NULL;
2044 }
2045 
2046 /**
2047  * smack_of_msq - the smack pointer for the msq
2048  * @msq: the object
2049  *
2050  * Returns a pointer to the smack value
2051  */
2052 static char *smack_of_msq(struct msg_queue *msq)
2053 {
2054 	return (char *)msq->q_perm.security;
2055 }
2056 
2057 /**
2058  * smk_curacc_msq : helper to check if current has access on msq
2059  * @msq : the msq
2060  * @access : access requested
2061  *
2062  * return 0 if current has access, error otherwise
2063  */
2064 static int smk_curacc_msq(struct msg_queue *msq, int access)
2065 {
2066 	char *msp = smack_of_msq(msq);
2067 	struct smk_audit_info ad;
2068 
2069 #ifdef CONFIG_AUDIT
2070 	smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_IPC);
2071 	ad.a.u.ipc_id = msq->q_perm.id;
2072 #endif
2073 	return smk_curacc(msp, access, &ad);
2074 }
2075 
2076 /**
2077  * smack_msg_queue_associate - Smack access check for msg_queue
2078  * @msq: the object
2079  * @msqflg: access requested
2080  *
2081  * Returns 0 if current has the requested access, error code otherwise
2082  */
2083 static int smack_msg_queue_associate(struct msg_queue *msq, int msqflg)
2084 {
2085 	int may;
2086 
2087 	may = smack_flags_to_may(msqflg);
2088 	return smk_curacc_msq(msq, may);
2089 }
2090 
2091 /**
2092  * smack_msg_queue_msgctl - Smack access check for msg_queue
2093  * @msq: the object
2094  * @cmd: what it wants to do
2095  *
2096  * Returns 0 if current has the requested access, error code otherwise
2097  */
2098 static int smack_msg_queue_msgctl(struct msg_queue *msq, int cmd)
2099 {
2100 	int may;
2101 
2102 	switch (cmd) {
2103 	case IPC_STAT:
2104 	case MSG_STAT:
2105 		may = MAY_READ;
2106 		break;
2107 	case IPC_SET:
2108 	case IPC_RMID:
2109 		may = MAY_READWRITE;
2110 		break;
2111 	case IPC_INFO:
2112 	case MSG_INFO:
2113 		/*
2114 		 * System level information
2115 		 */
2116 		return 0;
2117 	default:
2118 		return -EINVAL;
2119 	}
2120 
2121 	return smk_curacc_msq(msq, may);
2122 }
2123 
2124 /**
2125  * smack_msg_queue_msgsnd - Smack access check for msg_queue
2126  * @msq: the object
2127  * @msg: unused
2128  * @msqflg: access requested
2129  *
2130  * Returns 0 if current has the requested access, error code otherwise
2131  */
2132 static int smack_msg_queue_msgsnd(struct msg_queue *msq, struct msg_msg *msg,
2133 				  int msqflg)
2134 {
2135 	int may;
2136 
2137 	may = smack_flags_to_may(msqflg);
2138 	return smk_curacc_msq(msq, may);
2139 }
2140 
2141 /**
2142  * smack_msg_queue_msgsnd - Smack access check for msg_queue
2143  * @msq: the object
2144  * @msg: unused
2145  * @target: unused
2146  * @type: unused
2147  * @mode: unused
2148  *
2149  * Returns 0 if current has read and write access, error code otherwise
2150  */
2151 static int smack_msg_queue_msgrcv(struct msg_queue *msq, struct msg_msg *msg,
2152 			struct task_struct *target, long type, int mode)
2153 {
2154 	return smk_curacc_msq(msq, MAY_READWRITE);
2155 }
2156 
2157 /**
2158  * smack_ipc_permission - Smack access for ipc_permission()
2159  * @ipp: the object permissions
2160  * @flag: access requested
2161  *
2162  * Returns 0 if current has read and write access, error code otherwise
2163  */
2164 static int smack_ipc_permission(struct kern_ipc_perm *ipp, short flag)
2165 {
2166 	char *isp = ipp->security;
2167 	int may = smack_flags_to_may(flag);
2168 	struct smk_audit_info ad;
2169 
2170 #ifdef CONFIG_AUDIT
2171 	smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_IPC);
2172 	ad.a.u.ipc_id = ipp->id;
2173 #endif
2174 	return smk_curacc(isp, may, &ad);
2175 }
2176 
2177 /**
2178  * smack_ipc_getsecid - Extract smack security id
2179  * @ipp: the object permissions
2180  * @secid: where result will be saved
2181  */
2182 static void smack_ipc_getsecid(struct kern_ipc_perm *ipp, u32 *secid)
2183 {
2184 	char *smack = ipp->security;
2185 
2186 	*secid = smack_to_secid(smack);
2187 }
2188 
2189 /**
2190  * smack_d_instantiate - Make sure the blob is correct on an inode
2191  * @opt_dentry: dentry where inode will be attached
2192  * @inode: the object
2193  *
2194  * Set the inode's security blob if it hasn't been done already.
2195  */
2196 static void smack_d_instantiate(struct dentry *opt_dentry, struct inode *inode)
2197 {
2198 	struct super_block *sbp;
2199 	struct superblock_smack *sbsp;
2200 	struct inode_smack *isp;
2201 	char *csp = current_security();
2202 	char *fetched;
2203 	char *final;
2204 	struct dentry *dp;
2205 
2206 	if (inode == NULL)
2207 		return;
2208 
2209 	isp = inode->i_security;
2210 
2211 	mutex_lock(&isp->smk_lock);
2212 	/*
2213 	 * If the inode is already instantiated
2214 	 * take the quick way out
2215 	 */
2216 	if (isp->smk_flags & SMK_INODE_INSTANT)
2217 		goto unlockandout;
2218 
2219 	sbp = inode->i_sb;
2220 	sbsp = sbp->s_security;
2221 	/*
2222 	 * We're going to use the superblock default label
2223 	 * if there's no label on the file.
2224 	 */
2225 	final = sbsp->smk_default;
2226 
2227 	/*
2228 	 * If this is the root inode the superblock
2229 	 * may be in the process of initialization.
2230 	 * If that is the case use the root value out
2231 	 * of the superblock.
2232 	 */
2233 	if (opt_dentry->d_parent == opt_dentry) {
2234 		isp->smk_inode = sbsp->smk_root;
2235 		isp->smk_flags |= SMK_INODE_INSTANT;
2236 		goto unlockandout;
2237 	}
2238 
2239 	/*
2240 	 * This is pretty hackish.
2241 	 * Casey says that we shouldn't have to do
2242 	 * file system specific code, but it does help
2243 	 * with keeping it simple.
2244 	 */
2245 	switch (sbp->s_magic) {
2246 	case SMACK_MAGIC:
2247 		/*
2248 		 * Casey says that it's a little embarassing
2249 		 * that the smack file system doesn't do
2250 		 * extended attributes.
2251 		 */
2252 		final = smack_known_star.smk_known;
2253 		break;
2254 	case PIPEFS_MAGIC:
2255 		/*
2256 		 * Casey says pipes are easy (?)
2257 		 */
2258 		final = smack_known_star.smk_known;
2259 		break;
2260 	case DEVPTS_SUPER_MAGIC:
2261 		/*
2262 		 * devpts seems content with the label of the task.
2263 		 * Programs that change smack have to treat the
2264 		 * pty with respect.
2265 		 */
2266 		final = csp;
2267 		break;
2268 	case SOCKFS_MAGIC:
2269 		/*
2270 		 * Casey says sockets get the smack of the task.
2271 		 */
2272 		final = csp;
2273 		break;
2274 	case PROC_SUPER_MAGIC:
2275 		/*
2276 		 * Casey says procfs appears not to care.
2277 		 * The superblock default suffices.
2278 		 */
2279 		break;
2280 	case TMPFS_MAGIC:
2281 		/*
2282 		 * Device labels should come from the filesystem,
2283 		 * but watch out, because they're volitile,
2284 		 * getting recreated on every reboot.
2285 		 */
2286 		final = smack_known_star.smk_known;
2287 		/*
2288 		 * No break.
2289 		 *
2290 		 * If a smack value has been set we want to use it,
2291 		 * but since tmpfs isn't giving us the opportunity
2292 		 * to set mount options simulate setting the
2293 		 * superblock default.
2294 		 */
2295 	default:
2296 		/*
2297 		 * This isn't an understood special case.
2298 		 * Get the value from the xattr.
2299 		 *
2300 		 * No xattr support means, alas, no SMACK label.
2301 		 * Use the aforeapplied default.
2302 		 * It would be curious if the label of the task
2303 		 * does not match that assigned.
2304 		 */
2305 		if (inode->i_op->getxattr == NULL)
2306 			break;
2307 		/*
2308 		 * Get the dentry for xattr.
2309 		 */
2310 		dp = dget(opt_dentry);
2311 		fetched = smk_fetch(inode, dp);
2312 		if (fetched != NULL)
2313 			final = fetched;
2314 		dput(dp);
2315 		break;
2316 	}
2317 
2318 	if (final == NULL)
2319 		isp->smk_inode = csp;
2320 	else
2321 		isp->smk_inode = final;
2322 
2323 	isp->smk_flags |= SMK_INODE_INSTANT;
2324 
2325 unlockandout:
2326 	mutex_unlock(&isp->smk_lock);
2327 	return;
2328 }
2329 
2330 /**
2331  * smack_getprocattr - Smack process attribute access
2332  * @p: the object task
2333  * @name: the name of the attribute in /proc/.../attr
2334  * @value: where to put the result
2335  *
2336  * Places a copy of the task Smack into value
2337  *
2338  * Returns the length of the smack label or an error code
2339  */
2340 static int smack_getprocattr(struct task_struct *p, char *name, char **value)
2341 {
2342 	char *cp;
2343 	int slen;
2344 
2345 	if (strcmp(name, "current") != 0)
2346 		return -EINVAL;
2347 
2348 	cp = kstrdup(task_security(p), GFP_KERNEL);
2349 	if (cp == NULL)
2350 		return -ENOMEM;
2351 
2352 	slen = strlen(cp);
2353 	*value = cp;
2354 	return slen;
2355 }
2356 
2357 /**
2358  * smack_setprocattr - Smack process attribute setting
2359  * @p: the object task
2360  * @name: the name of the attribute in /proc/.../attr
2361  * @value: the value to set
2362  * @size: the size of the value
2363  *
2364  * Sets the Smack value of the task. Only setting self
2365  * is permitted and only with privilege
2366  *
2367  * Returns the length of the smack label or an error code
2368  */
2369 static int smack_setprocattr(struct task_struct *p, char *name,
2370 			     void *value, size_t size)
2371 {
2372 	struct cred *new;
2373 	char *newsmack;
2374 
2375 	/*
2376 	 * Changing another process' Smack value is too dangerous
2377 	 * and supports no sane use case.
2378 	 */
2379 	if (p != current)
2380 		return -EPERM;
2381 
2382 	if (!capable(CAP_MAC_ADMIN))
2383 		return -EPERM;
2384 
2385 	if (value == NULL || size == 0 || size >= SMK_LABELLEN)
2386 		return -EINVAL;
2387 
2388 	if (strcmp(name, "current") != 0)
2389 		return -EINVAL;
2390 
2391 	newsmack = smk_import(value, size);
2392 	if (newsmack == NULL)
2393 		return -EINVAL;
2394 
2395 	/*
2396 	 * No process is ever allowed the web ("@") label.
2397 	 */
2398 	if (newsmack == smack_known_web.smk_known)
2399 		return -EPERM;
2400 
2401 	new = prepare_creds();
2402 	if (new == NULL)
2403 		return -ENOMEM;
2404 	new->security = newsmack;
2405 	commit_creds(new);
2406 	return size;
2407 }
2408 
2409 /**
2410  * smack_unix_stream_connect - Smack access on UDS
2411  * @sock: one sock
2412  * @other: the other sock
2413  * @newsk: unused
2414  *
2415  * Return 0 if a subject with the smack of sock could access
2416  * an object with the smack of other, otherwise an error code
2417  */
2418 static int smack_unix_stream_connect(struct sock *sock,
2419 				     struct sock *other, struct sock *newsk)
2420 {
2421 	struct inode *sp = SOCK_INODE(sock->sk_socket);
2422 	struct inode *op = SOCK_INODE(other->sk_socket);
2423 	struct smk_audit_info ad;
2424 
2425 	smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_NET);
2426 	smk_ad_setfield_u_net_sk(&ad, other);
2427 	return smk_access(smk_of_inode(sp), smk_of_inode(op),
2428 				 MAY_READWRITE, &ad);
2429 }
2430 
2431 /**
2432  * smack_unix_may_send - Smack access on UDS
2433  * @sock: one socket
2434  * @other: the other socket
2435  *
2436  * Return 0 if a subject with the smack of sock could access
2437  * an object with the smack of other, otherwise an error code
2438  */
2439 static int smack_unix_may_send(struct socket *sock, struct socket *other)
2440 {
2441 	struct inode *sp = SOCK_INODE(sock);
2442 	struct inode *op = SOCK_INODE(other);
2443 	struct smk_audit_info ad;
2444 
2445 	smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_NET);
2446 	smk_ad_setfield_u_net_sk(&ad, other->sk);
2447 	return smk_access(smk_of_inode(sp), smk_of_inode(op), MAY_WRITE, &ad);
2448 }
2449 
2450 /**
2451  * smack_socket_sendmsg - Smack check based on destination host
2452  * @sock: the socket
2453  * @msg: the message
2454  * @size: the size of the message
2455  *
2456  * Return 0 if the current subject can write to the destination
2457  * host. This is only a question if the destination is a single
2458  * label host.
2459  */
2460 static int smack_socket_sendmsg(struct socket *sock, struct msghdr *msg,
2461 				int size)
2462 {
2463 	struct sockaddr_in *sip = (struct sockaddr_in *) msg->msg_name;
2464 
2465 	/*
2466 	 * Perfectly reasonable for this to be NULL
2467 	 */
2468 	if (sip == NULL || sip->sin_family != AF_INET)
2469 		return 0;
2470 
2471 	return smack_netlabel_send(sock->sk, sip);
2472 }
2473 
2474 
2475 /**
2476  * smack_from_secattr - Convert a netlabel attr.mls.lvl/attr.mls.cat pair to smack
2477  * @sap: netlabel secattr
2478  * @sip: where to put the result
2479  *
2480  * Copies a smack label into sip
2481  */
2482 static void smack_from_secattr(struct netlbl_lsm_secattr *sap, char *sip)
2483 {
2484 	char smack[SMK_LABELLEN];
2485 	char *sp;
2486 	int pcat;
2487 
2488 	if ((sap->flags & NETLBL_SECATTR_MLS_LVL) != 0) {
2489 		/*
2490 		 * Looks like a CIPSO packet.
2491 		 * If there are flags but no level netlabel isn't
2492 		 * behaving the way we expect it to.
2493 		 *
2494 		 * Get the categories, if any
2495 		 * Without guidance regarding the smack value
2496 		 * for the packet fall back on the network
2497 		 * ambient value.
2498 		 */
2499 		memset(smack, '\0', SMK_LABELLEN);
2500 		if ((sap->flags & NETLBL_SECATTR_MLS_CAT) != 0)
2501 			for (pcat = -1;;) {
2502 				pcat = netlbl_secattr_catmap_walk(
2503 					sap->attr.mls.cat, pcat + 1);
2504 				if (pcat < 0)
2505 					break;
2506 				smack_catset_bit(pcat, smack);
2507 			}
2508 		/*
2509 		 * If it is CIPSO using smack direct mapping
2510 		 * we are already done. WeeHee.
2511 		 */
2512 		if (sap->attr.mls.lvl == smack_cipso_direct) {
2513 			memcpy(sip, smack, SMK_MAXLEN);
2514 			return;
2515 		}
2516 		/*
2517 		 * Look it up in the supplied table if it is not
2518 		 * a direct mapping.
2519 		 */
2520 		smack_from_cipso(sap->attr.mls.lvl, smack, sip);
2521 		return;
2522 	}
2523 	if ((sap->flags & NETLBL_SECATTR_SECID) != 0) {
2524 		/*
2525 		 * Looks like a fallback, which gives us a secid.
2526 		 */
2527 		sp = smack_from_secid(sap->attr.secid);
2528 		/*
2529 		 * This has got to be a bug because it is
2530 		 * impossible to specify a fallback without
2531 		 * specifying the label, which will ensure
2532 		 * it has a secid, and the only way to get a
2533 		 * secid is from a fallback.
2534 		 */
2535 		BUG_ON(sp == NULL);
2536 		strncpy(sip, sp, SMK_MAXLEN);
2537 		return;
2538 	}
2539 	/*
2540 	 * Without guidance regarding the smack value
2541 	 * for the packet fall back on the network
2542 	 * ambient value.
2543 	 */
2544 	strncpy(sip, smack_net_ambient, SMK_MAXLEN);
2545 	return;
2546 }
2547 
2548 /**
2549  * smack_socket_sock_rcv_skb - Smack packet delivery access check
2550  * @sk: socket
2551  * @skb: packet
2552  *
2553  * Returns 0 if the packet should be delivered, an error code otherwise
2554  */
2555 static int smack_socket_sock_rcv_skb(struct sock *sk, struct sk_buff *skb)
2556 {
2557 	struct netlbl_lsm_secattr secattr;
2558 	struct socket_smack *ssp = sk->sk_security;
2559 	char smack[SMK_LABELLEN];
2560 	char *csp;
2561 	int rc;
2562 	struct smk_audit_info ad;
2563 	if (sk->sk_family != PF_INET && sk->sk_family != PF_INET6)
2564 		return 0;
2565 
2566 	/*
2567 	 * Translate what netlabel gave us.
2568 	 */
2569 	netlbl_secattr_init(&secattr);
2570 
2571 	rc = netlbl_skbuff_getattr(skb, sk->sk_family, &secattr);
2572 	if (rc == 0) {
2573 		smack_from_secattr(&secattr, smack);
2574 		csp = smack;
2575 	} else
2576 		csp = smack_net_ambient;
2577 
2578 	netlbl_secattr_destroy(&secattr);
2579 
2580 #ifdef CONFIG_AUDIT
2581 	smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_NET);
2582 	ad.a.u.net.family = sk->sk_family;
2583 	ad.a.u.net.netif = skb->skb_iif;
2584 	ipv4_skb_to_auditdata(skb, &ad.a, NULL);
2585 #endif
2586 	/*
2587 	 * Receiving a packet requires that the other end
2588 	 * be able to write here. Read access is not required.
2589 	 * This is the simplist possible security model
2590 	 * for networking.
2591 	 */
2592 	rc = smk_access(csp, ssp->smk_in, MAY_WRITE, &ad);
2593 	if (rc != 0)
2594 		netlbl_skbuff_err(skb, rc, 0);
2595 	return rc;
2596 }
2597 
2598 /**
2599  * smack_socket_getpeersec_stream - pull in packet label
2600  * @sock: the socket
2601  * @optval: user's destination
2602  * @optlen: size thereof
2603  * @len: max thereof
2604  *
2605  * returns zero on success, an error code otherwise
2606  */
2607 static int smack_socket_getpeersec_stream(struct socket *sock,
2608 					  char __user *optval,
2609 					  int __user *optlen, unsigned len)
2610 {
2611 	struct socket_smack *ssp;
2612 	int slen;
2613 	int rc = 0;
2614 
2615 	ssp = sock->sk->sk_security;
2616 	slen = strlen(ssp->smk_packet) + 1;
2617 
2618 	if (slen > len)
2619 		rc = -ERANGE;
2620 	else if (copy_to_user(optval, ssp->smk_packet, slen) != 0)
2621 		rc = -EFAULT;
2622 
2623 	if (put_user(slen, optlen) != 0)
2624 		rc = -EFAULT;
2625 
2626 	return rc;
2627 }
2628 
2629 
2630 /**
2631  * smack_socket_getpeersec_dgram - pull in packet label
2632  * @sock: the socket
2633  * @skb: packet data
2634  * @secid: pointer to where to put the secid of the packet
2635  *
2636  * Sets the netlabel socket state on sk from parent
2637  */
2638 static int smack_socket_getpeersec_dgram(struct socket *sock,
2639 					 struct sk_buff *skb, u32 *secid)
2640 
2641 {
2642 	struct netlbl_lsm_secattr secattr;
2643 	struct sock *sk;
2644 	char smack[SMK_LABELLEN];
2645 	int family = PF_INET;
2646 	u32 s;
2647 	int rc;
2648 
2649 	/*
2650 	 * Only works for families with packets.
2651 	 */
2652 	if (sock != NULL) {
2653 		sk = sock->sk;
2654 		if (sk->sk_family != PF_INET && sk->sk_family != PF_INET6)
2655 			return 0;
2656 		family = sk->sk_family;
2657 	}
2658 	/*
2659 	 * Translate what netlabel gave us.
2660 	 */
2661 	netlbl_secattr_init(&secattr);
2662 	rc = netlbl_skbuff_getattr(skb, family, &secattr);
2663 	if (rc == 0)
2664 		smack_from_secattr(&secattr, smack);
2665 	netlbl_secattr_destroy(&secattr);
2666 
2667 	/*
2668 	 * Give up if we couldn't get anything
2669 	 */
2670 	if (rc != 0)
2671 		return rc;
2672 
2673 	s = smack_to_secid(smack);
2674 	if (s == 0)
2675 		return -EINVAL;
2676 
2677 	*secid = s;
2678 	return 0;
2679 }
2680 
2681 /**
2682  * smack_sock_graft - Initialize a newly created socket with an existing sock
2683  * @sk: child sock
2684  * @parent: parent socket
2685  *
2686  * Set the smk_{in,out} state of an existing sock based on the process that
2687  * is creating the new socket.
2688  */
2689 static void smack_sock_graft(struct sock *sk, struct socket *parent)
2690 {
2691 	struct socket_smack *ssp;
2692 
2693 	if (sk == NULL ||
2694 	    (sk->sk_family != PF_INET && sk->sk_family != PF_INET6))
2695 		return;
2696 
2697 	ssp = sk->sk_security;
2698 	ssp->smk_in = ssp->smk_out = current_security();
2699 	/* cssp->smk_packet is already set in smack_inet_csk_clone() */
2700 }
2701 
2702 /**
2703  * smack_inet_conn_request - Smack access check on connect
2704  * @sk: socket involved
2705  * @skb: packet
2706  * @req: unused
2707  *
2708  * Returns 0 if a task with the packet label could write to
2709  * the socket, otherwise an error code
2710  */
2711 static int smack_inet_conn_request(struct sock *sk, struct sk_buff *skb,
2712 				   struct request_sock *req)
2713 {
2714 	u16 family = sk->sk_family;
2715 	struct socket_smack *ssp = sk->sk_security;
2716 	struct netlbl_lsm_secattr secattr;
2717 	struct sockaddr_in addr;
2718 	struct iphdr *hdr;
2719 	char smack[SMK_LABELLEN];
2720 	int rc;
2721 	struct smk_audit_info ad;
2722 
2723 	/* handle mapped IPv4 packets arriving via IPv6 sockets */
2724 	if (family == PF_INET6 && skb->protocol == htons(ETH_P_IP))
2725 		family = PF_INET;
2726 
2727 	netlbl_secattr_init(&secattr);
2728 	rc = netlbl_skbuff_getattr(skb, family, &secattr);
2729 	if (rc == 0)
2730 		smack_from_secattr(&secattr, smack);
2731 	else
2732 		strncpy(smack, smack_known_huh.smk_known, SMK_MAXLEN);
2733 	netlbl_secattr_destroy(&secattr);
2734 
2735 #ifdef CONFIG_AUDIT
2736 	smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_NET);
2737 	ad.a.u.net.family = family;
2738 	ad.a.u.net.netif = skb->skb_iif;
2739 	ipv4_skb_to_auditdata(skb, &ad.a, NULL);
2740 #endif
2741 	/*
2742 	 * Receiving a packet requires that the other end be able to write
2743 	 * here. Read access is not required.
2744 	 */
2745 	rc = smk_access(smack, ssp->smk_in, MAY_WRITE, &ad);
2746 	if (rc != 0)
2747 		return rc;
2748 
2749 	/*
2750 	 * Save the peer's label in the request_sock so we can later setup
2751 	 * smk_packet in the child socket so that SO_PEERCRED can report it.
2752 	 */
2753 	req->peer_secid = smack_to_secid(smack);
2754 
2755 	/*
2756 	 * We need to decide if we want to label the incoming connection here
2757 	 * if we do we only need to label the request_sock and the stack will
2758 	 * propogate the wire-label to the sock when it is created.
2759 	 */
2760 	hdr = ip_hdr(skb);
2761 	addr.sin_addr.s_addr = hdr->saddr;
2762 	rcu_read_lock();
2763 	if (smack_host_label(&addr) == NULL) {
2764 		rcu_read_unlock();
2765 		netlbl_secattr_init(&secattr);
2766 		smack_to_secattr(smack, &secattr);
2767 		rc = netlbl_req_setattr(req, &secattr);
2768 		netlbl_secattr_destroy(&secattr);
2769 	} else {
2770 		rcu_read_unlock();
2771 		netlbl_req_delattr(req);
2772 	}
2773 
2774 	return rc;
2775 }
2776 
2777 /**
2778  * smack_inet_csk_clone - Copy the connection information to the new socket
2779  * @sk: the new socket
2780  * @req: the connection's request_sock
2781  *
2782  * Transfer the connection's peer label to the newly created socket.
2783  */
2784 static void smack_inet_csk_clone(struct sock *sk,
2785 				 const struct request_sock *req)
2786 {
2787 	struct socket_smack *ssp = sk->sk_security;
2788 	char *smack;
2789 
2790 	if (req->peer_secid != 0) {
2791 		smack = smack_from_secid(req->peer_secid);
2792 		strncpy(ssp->smk_packet, smack, SMK_MAXLEN);
2793 	} else
2794 		ssp->smk_packet[0] = '\0';
2795 }
2796 
2797 /*
2798  * Key management security hooks
2799  *
2800  * Casey has not tested key support very heavily.
2801  * The permission check is most likely too restrictive.
2802  * If you care about keys please have a look.
2803  */
2804 #ifdef CONFIG_KEYS
2805 
2806 /**
2807  * smack_key_alloc - Set the key security blob
2808  * @key: object
2809  * @cred: the credentials to use
2810  * @flags: unused
2811  *
2812  * No allocation required
2813  *
2814  * Returns 0
2815  */
2816 static int smack_key_alloc(struct key *key, const struct cred *cred,
2817 			   unsigned long flags)
2818 {
2819 	key->security = cred->security;
2820 	return 0;
2821 }
2822 
2823 /**
2824  * smack_key_free - Clear the key security blob
2825  * @key: the object
2826  *
2827  * Clear the blob pointer
2828  */
2829 static void smack_key_free(struct key *key)
2830 {
2831 	key->security = NULL;
2832 }
2833 
2834 /*
2835  * smack_key_permission - Smack access on a key
2836  * @key_ref: gets to the object
2837  * @cred: the credentials to use
2838  * @perm: unused
2839  *
2840  * Return 0 if the task has read and write to the object,
2841  * an error code otherwise
2842  */
2843 static int smack_key_permission(key_ref_t key_ref,
2844 				const struct cred *cred, key_perm_t perm)
2845 {
2846 	struct key *keyp;
2847 	struct smk_audit_info ad;
2848 
2849 	keyp = key_ref_to_ptr(key_ref);
2850 	if (keyp == NULL)
2851 		return -EINVAL;
2852 	/*
2853 	 * If the key hasn't been initialized give it access so that
2854 	 * it may do so.
2855 	 */
2856 	if (keyp->security == NULL)
2857 		return 0;
2858 	/*
2859 	 * This should not occur
2860 	 */
2861 	if (cred->security == NULL)
2862 		return -EACCES;
2863 #ifdef CONFIG_AUDIT
2864 	smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_KEY);
2865 	ad.a.u.key_struct.key = keyp->serial;
2866 	ad.a.u.key_struct.key_desc = keyp->description;
2867 #endif
2868 	return smk_access(cred->security, keyp->security,
2869 				 MAY_READWRITE, &ad);
2870 }
2871 #endif /* CONFIG_KEYS */
2872 
2873 /*
2874  * Smack Audit hooks
2875  *
2876  * Audit requires a unique representation of each Smack specific
2877  * rule. This unique representation is used to distinguish the
2878  * object to be audited from remaining kernel objects and also
2879  * works as a glue between the audit hooks.
2880  *
2881  * Since repository entries are added but never deleted, we'll use
2882  * the smack_known label address related to the given audit rule as
2883  * the needed unique representation. This also better fits the smack
2884  * model where nearly everything is a label.
2885  */
2886 #ifdef CONFIG_AUDIT
2887 
2888 /**
2889  * smack_audit_rule_init - Initialize a smack audit rule
2890  * @field: audit rule fields given from user-space (audit.h)
2891  * @op: required testing operator (=, !=, >, <, ...)
2892  * @rulestr: smack label to be audited
2893  * @vrule: pointer to save our own audit rule representation
2894  *
2895  * Prepare to audit cases where (@field @op @rulestr) is true.
2896  * The label to be audited is created if necessay.
2897  */
2898 static int smack_audit_rule_init(u32 field, u32 op, char *rulestr, void **vrule)
2899 {
2900 	char **rule = (char **)vrule;
2901 	*rule = NULL;
2902 
2903 	if (field != AUDIT_SUBJ_USER && field != AUDIT_OBJ_USER)
2904 		return -EINVAL;
2905 
2906 	if (op != Audit_equal && op != Audit_not_equal)
2907 		return -EINVAL;
2908 
2909 	*rule = smk_import(rulestr, 0);
2910 
2911 	return 0;
2912 }
2913 
2914 /**
2915  * smack_audit_rule_known - Distinguish Smack audit rules
2916  * @krule: rule of interest, in Audit kernel representation format
2917  *
2918  * This is used to filter Smack rules from remaining Audit ones.
2919  * If it's proved that this rule belongs to us, the
2920  * audit_rule_match hook will be called to do the final judgement.
2921  */
2922 static int smack_audit_rule_known(struct audit_krule *krule)
2923 {
2924 	struct audit_field *f;
2925 	int i;
2926 
2927 	for (i = 0; i < krule->field_count; i++) {
2928 		f = &krule->fields[i];
2929 
2930 		if (f->type == AUDIT_SUBJ_USER || f->type == AUDIT_OBJ_USER)
2931 			return 1;
2932 	}
2933 
2934 	return 0;
2935 }
2936 
2937 /**
2938  * smack_audit_rule_match - Audit given object ?
2939  * @secid: security id for identifying the object to test
2940  * @field: audit rule flags given from user-space
2941  * @op: required testing operator
2942  * @vrule: smack internal rule presentation
2943  * @actx: audit context associated with the check
2944  *
2945  * The core Audit hook. It's used to take the decision of
2946  * whether to audit or not to audit a given object.
2947  */
2948 static int smack_audit_rule_match(u32 secid, u32 field, u32 op, void *vrule,
2949 				  struct audit_context *actx)
2950 {
2951 	char *smack;
2952 	char *rule = vrule;
2953 
2954 	if (!rule) {
2955 		audit_log(actx, GFP_KERNEL, AUDIT_SELINUX_ERR,
2956 			  "Smack: missing rule\n");
2957 		return -ENOENT;
2958 	}
2959 
2960 	if (field != AUDIT_SUBJ_USER && field != AUDIT_OBJ_USER)
2961 		return 0;
2962 
2963 	smack = smack_from_secid(secid);
2964 
2965 	/*
2966 	 * No need to do string comparisons. If a match occurs,
2967 	 * both pointers will point to the same smack_known
2968 	 * label.
2969 	 */
2970 	if (op == Audit_equal)
2971 		return (rule == smack);
2972 	if (op == Audit_not_equal)
2973 		return (rule != smack);
2974 
2975 	return 0;
2976 }
2977 
2978 /**
2979  * smack_audit_rule_free - free smack rule representation
2980  * @vrule: rule to be freed.
2981  *
2982  * No memory was allocated.
2983  */
2984 static void smack_audit_rule_free(void *vrule)
2985 {
2986 	/* No-op */
2987 }
2988 
2989 #endif /* CONFIG_AUDIT */
2990 
2991 /**
2992  * smack_secid_to_secctx - return the smack label for a secid
2993  * @secid: incoming integer
2994  * @secdata: destination
2995  * @seclen: how long it is
2996  *
2997  * Exists for networking code.
2998  */
2999 static int smack_secid_to_secctx(u32 secid, char **secdata, u32 *seclen)
3000 {
3001 	char *sp = smack_from_secid(secid);
3002 
3003 	if (secdata)
3004 		*secdata = sp;
3005 	*seclen = strlen(sp);
3006 	return 0;
3007 }
3008 
3009 /**
3010  * smack_secctx_to_secid - return the secid for a smack label
3011  * @secdata: smack label
3012  * @seclen: how long result is
3013  * @secid: outgoing integer
3014  *
3015  * Exists for audit and networking code.
3016  */
3017 static int smack_secctx_to_secid(const char *secdata, u32 seclen, u32 *secid)
3018 {
3019 	*secid = smack_to_secid(secdata);
3020 	return 0;
3021 }
3022 
3023 /**
3024  * smack_release_secctx - don't do anything.
3025  * @secdata: unused
3026  * @seclen: unused
3027  *
3028  * Exists to make sure nothing gets done, and properly
3029  */
3030 static void smack_release_secctx(char *secdata, u32 seclen)
3031 {
3032 }
3033 
3034 static int smack_inode_notifysecctx(struct inode *inode, void *ctx, u32 ctxlen)
3035 {
3036 	return smack_inode_setsecurity(inode, XATTR_SMACK_SUFFIX, ctx, ctxlen, 0);
3037 }
3038 
3039 static int smack_inode_setsecctx(struct dentry *dentry, void *ctx, u32 ctxlen)
3040 {
3041 	return __vfs_setxattr_noperm(dentry, XATTR_NAME_SMACK, ctx, ctxlen, 0);
3042 }
3043 
3044 static int smack_inode_getsecctx(struct inode *inode, void **ctx, u32 *ctxlen)
3045 {
3046 	int len = 0;
3047 	len = smack_inode_getsecurity(inode, XATTR_SMACK_SUFFIX, ctx, true);
3048 
3049 	if (len < 0)
3050 		return len;
3051 	*ctxlen = len;
3052 	return 0;
3053 }
3054 
3055 struct security_operations smack_ops = {
3056 	.name =				"smack",
3057 
3058 	.ptrace_access_check =		smack_ptrace_access_check,
3059 	.ptrace_traceme =		smack_ptrace_traceme,
3060 	.syslog = 			smack_syslog,
3061 
3062 	.sb_alloc_security = 		smack_sb_alloc_security,
3063 	.sb_free_security = 		smack_sb_free_security,
3064 	.sb_copy_data = 		smack_sb_copy_data,
3065 	.sb_kern_mount = 		smack_sb_kern_mount,
3066 	.sb_statfs = 			smack_sb_statfs,
3067 	.sb_mount = 			smack_sb_mount,
3068 	.sb_umount = 			smack_sb_umount,
3069 
3070 	.inode_alloc_security = 	smack_inode_alloc_security,
3071 	.inode_free_security = 		smack_inode_free_security,
3072 	.inode_init_security = 		smack_inode_init_security,
3073 	.inode_link = 			smack_inode_link,
3074 	.inode_unlink = 		smack_inode_unlink,
3075 	.inode_rmdir = 			smack_inode_rmdir,
3076 	.inode_rename = 		smack_inode_rename,
3077 	.inode_permission = 		smack_inode_permission,
3078 	.inode_setattr = 		smack_inode_setattr,
3079 	.inode_getattr = 		smack_inode_getattr,
3080 	.inode_setxattr = 		smack_inode_setxattr,
3081 	.inode_post_setxattr = 		smack_inode_post_setxattr,
3082 	.inode_getxattr = 		smack_inode_getxattr,
3083 	.inode_removexattr = 		smack_inode_removexattr,
3084 	.inode_getsecurity = 		smack_inode_getsecurity,
3085 	.inode_setsecurity = 		smack_inode_setsecurity,
3086 	.inode_listsecurity = 		smack_inode_listsecurity,
3087 	.inode_getsecid =		smack_inode_getsecid,
3088 
3089 	.file_permission = 		smack_file_permission,
3090 	.file_alloc_security = 		smack_file_alloc_security,
3091 	.file_free_security = 		smack_file_free_security,
3092 	.file_ioctl = 			smack_file_ioctl,
3093 	.file_lock = 			smack_file_lock,
3094 	.file_fcntl = 			smack_file_fcntl,
3095 	.file_set_fowner = 		smack_file_set_fowner,
3096 	.file_send_sigiotask = 		smack_file_send_sigiotask,
3097 	.file_receive = 		smack_file_receive,
3098 
3099 	.cred_alloc_blank =		smack_cred_alloc_blank,
3100 	.cred_free =			smack_cred_free,
3101 	.cred_prepare =			smack_cred_prepare,
3102 	.cred_transfer =		smack_cred_transfer,
3103 	.kernel_act_as =		smack_kernel_act_as,
3104 	.kernel_create_files_as =	smack_kernel_create_files_as,
3105 	.task_setpgid = 		smack_task_setpgid,
3106 	.task_getpgid = 		smack_task_getpgid,
3107 	.task_getsid = 			smack_task_getsid,
3108 	.task_getsecid = 		smack_task_getsecid,
3109 	.task_setnice = 		smack_task_setnice,
3110 	.task_setioprio = 		smack_task_setioprio,
3111 	.task_getioprio = 		smack_task_getioprio,
3112 	.task_setscheduler = 		smack_task_setscheduler,
3113 	.task_getscheduler = 		smack_task_getscheduler,
3114 	.task_movememory = 		smack_task_movememory,
3115 	.task_kill = 			smack_task_kill,
3116 	.task_wait = 			smack_task_wait,
3117 	.task_to_inode = 		smack_task_to_inode,
3118 
3119 	.ipc_permission = 		smack_ipc_permission,
3120 	.ipc_getsecid =			smack_ipc_getsecid,
3121 
3122 	.msg_msg_alloc_security = 	smack_msg_msg_alloc_security,
3123 	.msg_msg_free_security = 	smack_msg_msg_free_security,
3124 
3125 	.msg_queue_alloc_security = 	smack_msg_queue_alloc_security,
3126 	.msg_queue_free_security = 	smack_msg_queue_free_security,
3127 	.msg_queue_associate = 		smack_msg_queue_associate,
3128 	.msg_queue_msgctl = 		smack_msg_queue_msgctl,
3129 	.msg_queue_msgsnd = 		smack_msg_queue_msgsnd,
3130 	.msg_queue_msgrcv = 		smack_msg_queue_msgrcv,
3131 
3132 	.shm_alloc_security = 		smack_shm_alloc_security,
3133 	.shm_free_security = 		smack_shm_free_security,
3134 	.shm_associate = 		smack_shm_associate,
3135 	.shm_shmctl = 			smack_shm_shmctl,
3136 	.shm_shmat = 			smack_shm_shmat,
3137 
3138 	.sem_alloc_security = 		smack_sem_alloc_security,
3139 	.sem_free_security = 		smack_sem_free_security,
3140 	.sem_associate = 		smack_sem_associate,
3141 	.sem_semctl = 			smack_sem_semctl,
3142 	.sem_semop = 			smack_sem_semop,
3143 
3144 	.d_instantiate = 		smack_d_instantiate,
3145 
3146 	.getprocattr = 			smack_getprocattr,
3147 	.setprocattr = 			smack_setprocattr,
3148 
3149 	.unix_stream_connect = 		smack_unix_stream_connect,
3150 	.unix_may_send = 		smack_unix_may_send,
3151 
3152 	.socket_post_create = 		smack_socket_post_create,
3153 	.socket_connect =		smack_socket_connect,
3154 	.socket_sendmsg =		smack_socket_sendmsg,
3155 	.socket_sock_rcv_skb = 		smack_socket_sock_rcv_skb,
3156 	.socket_getpeersec_stream =	smack_socket_getpeersec_stream,
3157 	.socket_getpeersec_dgram =	smack_socket_getpeersec_dgram,
3158 	.sk_alloc_security = 		smack_sk_alloc_security,
3159 	.sk_free_security = 		smack_sk_free_security,
3160 	.sock_graft = 			smack_sock_graft,
3161 	.inet_conn_request = 		smack_inet_conn_request,
3162 	.inet_csk_clone =		smack_inet_csk_clone,
3163 
3164  /* key management security hooks */
3165 #ifdef CONFIG_KEYS
3166 	.key_alloc = 			smack_key_alloc,
3167 	.key_free = 			smack_key_free,
3168 	.key_permission = 		smack_key_permission,
3169 #endif /* CONFIG_KEYS */
3170 
3171  /* Audit hooks */
3172 #ifdef CONFIG_AUDIT
3173 	.audit_rule_init =		smack_audit_rule_init,
3174 	.audit_rule_known =		smack_audit_rule_known,
3175 	.audit_rule_match =		smack_audit_rule_match,
3176 	.audit_rule_free =		smack_audit_rule_free,
3177 #endif /* CONFIG_AUDIT */
3178 
3179 	.secid_to_secctx = 		smack_secid_to_secctx,
3180 	.secctx_to_secid = 		smack_secctx_to_secid,
3181 	.release_secctx = 		smack_release_secctx,
3182 	.inode_notifysecctx =		smack_inode_notifysecctx,
3183 	.inode_setsecctx =		smack_inode_setsecctx,
3184 	.inode_getsecctx =		smack_inode_getsecctx,
3185 };
3186 
3187 
3188 static __init void init_smack_know_list(void)
3189 {
3190 	list_add(&smack_known_huh.list, &smack_known_list);
3191 	list_add(&smack_known_hat.list, &smack_known_list);
3192 	list_add(&smack_known_star.list, &smack_known_list);
3193 	list_add(&smack_known_floor.list, &smack_known_list);
3194 	list_add(&smack_known_invalid.list, &smack_known_list);
3195 	list_add(&smack_known_web.list, &smack_known_list);
3196 }
3197 
3198 /**
3199  * smack_init - initialize the smack system
3200  *
3201  * Returns 0
3202  */
3203 static __init int smack_init(void)
3204 {
3205 	struct cred *cred;
3206 
3207 	if (!security_module_enable(&smack_ops))
3208 		return 0;
3209 
3210 	printk(KERN_INFO "Smack:  Initializing.\n");
3211 
3212 	/*
3213 	 * Set the security state for the initial task.
3214 	 */
3215 	cred = (struct cred *) current->cred;
3216 	cred->security = &smack_known_floor.smk_known;
3217 
3218 	/* initialize the smack_know_list */
3219 	init_smack_know_list();
3220 	/*
3221 	 * Initialize locks
3222 	 */
3223 	spin_lock_init(&smack_known_huh.smk_cipsolock);
3224 	spin_lock_init(&smack_known_hat.smk_cipsolock);
3225 	spin_lock_init(&smack_known_star.smk_cipsolock);
3226 	spin_lock_init(&smack_known_floor.smk_cipsolock);
3227 	spin_lock_init(&smack_known_invalid.smk_cipsolock);
3228 
3229 	/*
3230 	 * Register with LSM
3231 	 */
3232 	if (register_security(&smack_ops))
3233 		panic("smack: Unable to register with kernel.\n");
3234 
3235 	return 0;
3236 }
3237 
3238 /*
3239  * Smack requires early initialization in order to label
3240  * all processes and objects when they are created.
3241  */
3242 security_initcall(smack_init);
3243