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e114e473 CS |
1 | /* |
2 | * Simplified MAC Kernel (smack) security module | |
3 | * | |
4 | * This file contains the smack hook function implementations. | |
5 | * | |
6 | * Author: | |
7 | * Casey Schaufler <casey@schaufler-ca.com> | |
8 | * | |
9 | * Copyright (C) 2007 Casey Schaufler <casey@schaufler-ca.com> | |
10 | * | |
11 | * This program is free software; you can redistribute it and/or modify | |
12 | * it under the terms of the GNU General Public License version 2, | |
13 | * as published by the Free Software Foundation. | |
14 | */ | |
15 | ||
16 | #include <linux/xattr.h> | |
17 | #include <linux/pagemap.h> | |
18 | #include <linux/mount.h> | |
19 | #include <linux/stat.h> | |
20 | #include <linux/ext2_fs.h> | |
21 | #include <linux/kd.h> | |
22 | #include <asm/ioctls.h> | |
23 | #include <linux/tcp.h> | |
24 | #include <linux/udp.h> | |
25 | #include <linux/mutex.h> | |
26 | #include <linux/pipe_fs_i.h> | |
27 | #include <net/netlabel.h> | |
28 | #include <net/cipso_ipv4.h> | |
29 | ||
30 | #include "smack.h" | |
31 | ||
32 | /* | |
33 | * I hope these are the hokeyist lines of code in the module. Casey. | |
34 | */ | |
35 | #define DEVPTS_SUPER_MAGIC 0x1cd1 | |
36 | #define SOCKFS_MAGIC 0x534F434B | |
37 | #define TMPFS_MAGIC 0x01021994 | |
38 | ||
39 | /** | |
40 | * smk_fetch - Fetch the smack label from a file. | |
41 | * @ip: a pointer to the inode | |
42 | * @dp: a pointer to the dentry | |
43 | * | |
44 | * Returns a pointer to the master list entry for the Smack label | |
45 | * or NULL if there was no label to fetch. | |
46 | */ | |
47 | static char *smk_fetch(struct inode *ip, struct dentry *dp) | |
48 | { | |
49 | int rc; | |
50 | char in[SMK_LABELLEN]; | |
51 | ||
52 | if (ip->i_op->getxattr == NULL) | |
53 | return NULL; | |
54 | ||
55 | rc = ip->i_op->getxattr(dp, XATTR_NAME_SMACK, in, SMK_LABELLEN); | |
56 | if (rc < 0) | |
57 | return NULL; | |
58 | ||
59 | return smk_import(in, rc); | |
60 | } | |
61 | ||
62 | /** | |
63 | * new_inode_smack - allocate an inode security blob | |
64 | * @smack: a pointer to the Smack label to use in the blob | |
65 | * | |
66 | * Returns the new blob or NULL if there's no memory available | |
67 | */ | |
68 | struct inode_smack *new_inode_smack(char *smack) | |
69 | { | |
70 | struct inode_smack *isp; | |
71 | ||
72 | isp = kzalloc(sizeof(struct inode_smack), GFP_KERNEL); | |
73 | if (isp == NULL) | |
74 | return NULL; | |
75 | ||
76 | isp->smk_inode = smack; | |
77 | isp->smk_flags = 0; | |
78 | mutex_init(&isp->smk_lock); | |
79 | ||
80 | return isp; | |
81 | } | |
82 | ||
83 | /* | |
84 | * LSM hooks. | |
85 | * We he, that is fun! | |
86 | */ | |
87 | ||
88 | /** | |
89 | * smack_ptrace - Smack approval on ptrace | |
90 | * @ptp: parent task pointer | |
91 | * @ctp: child task pointer | |
92 | * | |
93 | * Returns 0 if access is OK, an error code otherwise | |
94 | * | |
95 | * Do the capability checks, and require read and write. | |
96 | */ | |
97 | static int smack_ptrace(struct task_struct *ptp, struct task_struct *ctp) | |
98 | { | |
99 | int rc; | |
100 | ||
101 | rc = cap_ptrace(ptp, ctp); | |
102 | if (rc != 0) | |
103 | return rc; | |
104 | ||
105 | rc = smk_access(ptp->security, ctp->security, MAY_READWRITE); | |
106 | if (rc != 0 && __capable(ptp, CAP_MAC_OVERRIDE)) | |
107 | return 0; | |
108 | ||
109 | return rc; | |
110 | } | |
111 | ||
112 | /** | |
113 | * smack_syslog - Smack approval on syslog | |
114 | * @type: message type | |
115 | * | |
116 | * Require that the task has the floor label | |
117 | * | |
118 | * Returns 0 on success, error code otherwise. | |
119 | */ | |
120 | static int smack_syslog(int type) | |
121 | { | |
122 | int rc; | |
123 | char *sp = current->security; | |
124 | ||
125 | rc = cap_syslog(type); | |
126 | if (rc != 0) | |
127 | return rc; | |
128 | ||
129 | if (capable(CAP_MAC_OVERRIDE)) | |
130 | return 0; | |
131 | ||
132 | if (sp != smack_known_floor.smk_known) | |
133 | rc = -EACCES; | |
134 | ||
135 | return rc; | |
136 | } | |
137 | ||
138 | ||
139 | /* | |
140 | * Superblock Hooks. | |
141 | */ | |
142 | ||
143 | /** | |
144 | * smack_sb_alloc_security - allocate a superblock blob | |
145 | * @sb: the superblock getting the blob | |
146 | * | |
147 | * Returns 0 on success or -ENOMEM on error. | |
148 | */ | |
149 | static int smack_sb_alloc_security(struct super_block *sb) | |
150 | { | |
151 | struct superblock_smack *sbsp; | |
152 | ||
153 | sbsp = kzalloc(sizeof(struct superblock_smack), GFP_KERNEL); | |
154 | ||
155 | if (sbsp == NULL) | |
156 | return -ENOMEM; | |
157 | ||
158 | sbsp->smk_root = smack_known_floor.smk_known; | |
159 | sbsp->smk_default = smack_known_floor.smk_known; | |
160 | sbsp->smk_floor = smack_known_floor.smk_known; | |
161 | sbsp->smk_hat = smack_known_hat.smk_known; | |
162 | sbsp->smk_initialized = 0; | |
163 | spin_lock_init(&sbsp->smk_sblock); | |
164 | ||
165 | sb->s_security = sbsp; | |
166 | ||
167 | return 0; | |
168 | } | |
169 | ||
170 | /** | |
171 | * smack_sb_free_security - free a superblock blob | |
172 | * @sb: the superblock getting the blob | |
173 | * | |
174 | */ | |
175 | static void smack_sb_free_security(struct super_block *sb) | |
176 | { | |
177 | kfree(sb->s_security); | |
178 | sb->s_security = NULL; | |
179 | } | |
180 | ||
181 | /** | |
182 | * smack_sb_copy_data - copy mount options data for processing | |
183 | * @type: file system type | |
184 | * @orig: where to start | |
185 | * @smackopts | |
186 | * | |
187 | * Returns 0 on success or -ENOMEM on error. | |
188 | * | |
189 | * Copy the Smack specific mount options out of the mount | |
190 | * options list. | |
191 | */ | |
192 | static int smack_sb_copy_data(struct file_system_type *type, void *orig, | |
193 | void *smackopts) | |
194 | { | |
195 | char *cp, *commap, *otheropts, *dp; | |
196 | ||
197 | /* Binary mount data: just copy */ | |
198 | if (type->fs_flags & FS_BINARY_MOUNTDATA) { | |
199 | copy_page(smackopts, orig); | |
200 | return 0; | |
201 | } | |
202 | ||
203 | otheropts = (char *)get_zeroed_page(GFP_KERNEL); | |
204 | if (otheropts == NULL) | |
205 | return -ENOMEM; | |
206 | ||
207 | for (cp = orig, commap = orig; commap != NULL; cp = commap + 1) { | |
208 | if (strstr(cp, SMK_FSDEFAULT) == cp) | |
209 | dp = smackopts; | |
210 | else if (strstr(cp, SMK_FSFLOOR) == cp) | |
211 | dp = smackopts; | |
212 | else if (strstr(cp, SMK_FSHAT) == cp) | |
213 | dp = smackopts; | |
214 | else if (strstr(cp, SMK_FSROOT) == cp) | |
215 | dp = smackopts; | |
216 | else | |
217 | dp = otheropts; | |
218 | ||
219 | commap = strchr(cp, ','); | |
220 | if (commap != NULL) | |
221 | *commap = '\0'; | |
222 | ||
223 | if (*dp != '\0') | |
224 | strcat(dp, ","); | |
225 | strcat(dp, cp); | |
226 | } | |
227 | ||
228 | strcpy(orig, otheropts); | |
229 | free_page((unsigned long)otheropts); | |
230 | ||
231 | return 0; | |
232 | } | |
233 | ||
234 | /** | |
235 | * smack_sb_kern_mount - Smack specific mount processing | |
236 | * @sb: the file system superblock | |
237 | * @data: the smack mount options | |
238 | * | |
239 | * Returns 0 on success, an error code on failure | |
240 | */ | |
241 | static int smack_sb_kern_mount(struct super_block *sb, void *data) | |
242 | { | |
243 | struct dentry *root = sb->s_root; | |
244 | struct inode *inode = root->d_inode; | |
245 | struct superblock_smack *sp = sb->s_security; | |
246 | struct inode_smack *isp; | |
247 | char *op; | |
248 | char *commap; | |
249 | char *nsp; | |
250 | ||
251 | spin_lock(&sp->smk_sblock); | |
252 | if (sp->smk_initialized != 0) { | |
253 | spin_unlock(&sp->smk_sblock); | |
254 | return 0; | |
255 | } | |
256 | sp->smk_initialized = 1; | |
257 | spin_unlock(&sp->smk_sblock); | |
258 | ||
259 | for (op = data; op != NULL; op = commap) { | |
260 | commap = strchr(op, ','); | |
261 | if (commap != NULL) | |
262 | *commap++ = '\0'; | |
263 | ||
264 | if (strncmp(op, SMK_FSHAT, strlen(SMK_FSHAT)) == 0) { | |
265 | op += strlen(SMK_FSHAT); | |
266 | nsp = smk_import(op, 0); | |
267 | if (nsp != NULL) | |
268 | sp->smk_hat = nsp; | |
269 | } else if (strncmp(op, SMK_FSFLOOR, strlen(SMK_FSFLOOR)) == 0) { | |
270 | op += strlen(SMK_FSFLOOR); | |
271 | nsp = smk_import(op, 0); | |
272 | if (nsp != NULL) | |
273 | sp->smk_floor = nsp; | |
274 | } else if (strncmp(op, SMK_FSDEFAULT, | |
275 | strlen(SMK_FSDEFAULT)) == 0) { | |
276 | op += strlen(SMK_FSDEFAULT); | |
277 | nsp = smk_import(op, 0); | |
278 | if (nsp != NULL) | |
279 | sp->smk_default = nsp; | |
280 | } else if (strncmp(op, SMK_FSROOT, strlen(SMK_FSROOT)) == 0) { | |
281 | op += strlen(SMK_FSROOT); | |
282 | nsp = smk_import(op, 0); | |
283 | if (nsp != NULL) | |
284 | sp->smk_root = nsp; | |
285 | } | |
286 | } | |
287 | ||
288 | /* | |
289 | * Initialize the root inode. | |
290 | */ | |
291 | isp = inode->i_security; | |
292 | if (isp == NULL) | |
293 | inode->i_security = new_inode_smack(sp->smk_root); | |
294 | else | |
295 | isp->smk_inode = sp->smk_root; | |
296 | ||
297 | return 0; | |
298 | } | |
299 | ||
300 | /** | |
301 | * smack_sb_statfs - Smack check on statfs | |
302 | * @dentry: identifies the file system in question | |
303 | * | |
304 | * Returns 0 if current can read the floor of the filesystem, | |
305 | * and error code otherwise | |
306 | */ | |
307 | static int smack_sb_statfs(struct dentry *dentry) | |
308 | { | |
309 | struct superblock_smack *sbp = dentry->d_sb->s_security; | |
310 | ||
311 | return smk_curacc(sbp->smk_floor, MAY_READ); | |
312 | } | |
313 | ||
314 | /** | |
315 | * smack_sb_mount - Smack check for mounting | |
316 | * @dev_name: unused | |
317 | * @nd: mount point | |
318 | * @type: unused | |
319 | * @flags: unused | |
320 | * @data: unused | |
321 | * | |
322 | * Returns 0 if current can write the floor of the filesystem | |
323 | * being mounted on, an error code otherwise. | |
324 | */ | |
325 | static int smack_sb_mount(char *dev_name, struct nameidata *nd, | |
326 | char *type, unsigned long flags, void *data) | |
327 | { | |
328 | struct superblock_smack *sbp = nd->mnt->mnt_sb->s_security; | |
329 | ||
330 | return smk_curacc(sbp->smk_floor, MAY_WRITE); | |
331 | } | |
332 | ||
333 | /** | |
334 | * smack_sb_umount - Smack check for unmounting | |
335 | * @mnt: file system to unmount | |
336 | * @flags: unused | |
337 | * | |
338 | * Returns 0 if current can write the floor of the filesystem | |
339 | * being unmounted, an error code otherwise. | |
340 | */ | |
341 | static int smack_sb_umount(struct vfsmount *mnt, int flags) | |
342 | { | |
343 | struct superblock_smack *sbp; | |
344 | ||
345 | sbp = mnt->mnt_sb->s_security; | |
346 | ||
347 | return smk_curacc(sbp->smk_floor, MAY_WRITE); | |
348 | } | |
349 | ||
350 | /* | |
351 | * Inode hooks | |
352 | */ | |
353 | ||
354 | /** | |
355 | * smack_inode_alloc_security - allocate an inode blob | |
356 | * @inode - the inode in need of a blob | |
357 | * | |
358 | * Returns 0 if it gets a blob, -ENOMEM otherwise | |
359 | */ | |
360 | static int smack_inode_alloc_security(struct inode *inode) | |
361 | { | |
362 | inode->i_security = new_inode_smack(current->security); | |
363 | if (inode->i_security == NULL) | |
364 | return -ENOMEM; | |
365 | return 0; | |
366 | } | |
367 | ||
368 | /** | |
369 | * smack_inode_free_security - free an inode blob | |
370 | * @inode - the inode with a blob | |
371 | * | |
372 | * Clears the blob pointer in inode | |
373 | */ | |
374 | static void smack_inode_free_security(struct inode *inode) | |
375 | { | |
376 | kfree(inode->i_security); | |
377 | inode->i_security = NULL; | |
378 | } | |
379 | ||
380 | /** | |
381 | * smack_inode_init_security - copy out the smack from an inode | |
382 | * @inode: the inode | |
383 | * @dir: unused | |
384 | * @name: where to put the attribute name | |
385 | * @value: where to put the attribute value | |
386 | * @len: where to put the length of the attribute | |
387 | * | |
388 | * Returns 0 if it all works out, -ENOMEM if there's no memory | |
389 | */ | |
390 | static int smack_inode_init_security(struct inode *inode, struct inode *dir, | |
391 | char **name, void **value, size_t *len) | |
392 | { | |
393 | char *isp = smk_of_inode(inode); | |
394 | ||
395 | if (name) { | |
396 | *name = kstrdup(XATTR_SMACK_SUFFIX, GFP_KERNEL); | |
397 | if (*name == NULL) | |
398 | return -ENOMEM; | |
399 | } | |
400 | ||
401 | if (value) { | |
402 | *value = kstrdup(isp, GFP_KERNEL); | |
403 | if (*value == NULL) | |
404 | return -ENOMEM; | |
405 | } | |
406 | ||
407 | if (len) | |
408 | *len = strlen(isp) + 1; | |
409 | ||
410 | return 0; | |
411 | } | |
412 | ||
413 | /** | |
414 | * smack_inode_link - Smack check on link | |
415 | * @old_dentry: the existing object | |
416 | * @dir: unused | |
417 | * @new_dentry: the new object | |
418 | * | |
419 | * Returns 0 if access is permitted, an error code otherwise | |
420 | */ | |
421 | static int smack_inode_link(struct dentry *old_dentry, struct inode *dir, | |
422 | struct dentry *new_dentry) | |
423 | { | |
424 | int rc; | |
425 | char *isp; | |
426 | ||
427 | isp = smk_of_inode(old_dentry->d_inode); | |
428 | rc = smk_curacc(isp, MAY_WRITE); | |
429 | ||
430 | if (rc == 0 && new_dentry->d_inode != NULL) { | |
431 | isp = smk_of_inode(new_dentry->d_inode); | |
432 | rc = smk_curacc(isp, MAY_WRITE); | |
433 | } | |
434 | ||
435 | return rc; | |
436 | } | |
437 | ||
438 | /** | |
439 | * smack_inode_unlink - Smack check on inode deletion | |
440 | * @dir: containing directory object | |
441 | * @dentry: file to unlink | |
442 | * | |
443 | * Returns 0 if current can write the containing directory | |
444 | * and the object, error code otherwise | |
445 | */ | |
446 | static int smack_inode_unlink(struct inode *dir, struct dentry *dentry) | |
447 | { | |
448 | struct inode *ip = dentry->d_inode; | |
449 | int rc; | |
450 | ||
451 | /* | |
452 | * You need write access to the thing you're unlinking | |
453 | */ | |
454 | rc = smk_curacc(smk_of_inode(ip), MAY_WRITE); | |
455 | if (rc == 0) | |
456 | /* | |
457 | * You also need write access to the containing directory | |
458 | */ | |
459 | rc = smk_curacc(smk_of_inode(dir), MAY_WRITE); | |
460 | ||
461 | return rc; | |
462 | } | |
463 | ||
464 | /** | |
465 | * smack_inode_rmdir - Smack check on directory deletion | |
466 | * @dir: containing directory object | |
467 | * @dentry: directory to unlink | |
468 | * | |
469 | * Returns 0 if current can write the containing directory | |
470 | * and the directory, error code otherwise | |
471 | */ | |
472 | static int smack_inode_rmdir(struct inode *dir, struct dentry *dentry) | |
473 | { | |
474 | int rc; | |
475 | ||
476 | /* | |
477 | * You need write access to the thing you're removing | |
478 | */ | |
479 | rc = smk_curacc(smk_of_inode(dentry->d_inode), MAY_WRITE); | |
480 | if (rc == 0) | |
481 | /* | |
482 | * You also need write access to the containing directory | |
483 | */ | |
484 | rc = smk_curacc(smk_of_inode(dir), MAY_WRITE); | |
485 | ||
486 | return rc; | |
487 | } | |
488 | ||
489 | /** | |
490 | * smack_inode_rename - Smack check on rename | |
491 | * @old_inode: the old directory | |
492 | * @old_dentry: unused | |
493 | * @new_inode: the new directory | |
494 | * @new_dentry: unused | |
495 | * | |
496 | * Read and write access is required on both the old and | |
497 | * new directories. | |
498 | * | |
499 | * Returns 0 if access is permitted, an error code otherwise | |
500 | */ | |
501 | static int smack_inode_rename(struct inode *old_inode, | |
502 | struct dentry *old_dentry, | |
503 | struct inode *new_inode, | |
504 | struct dentry *new_dentry) | |
505 | { | |
506 | int rc; | |
507 | char *isp; | |
508 | ||
509 | isp = smk_of_inode(old_dentry->d_inode); | |
510 | rc = smk_curacc(isp, MAY_READWRITE); | |
511 | ||
512 | if (rc == 0 && new_dentry->d_inode != NULL) { | |
513 | isp = smk_of_inode(new_dentry->d_inode); | |
514 | rc = smk_curacc(isp, MAY_READWRITE); | |
515 | } | |
516 | ||
517 | return rc; | |
518 | } | |
519 | ||
520 | /** | |
521 | * smack_inode_permission - Smack version of permission() | |
522 | * @inode: the inode in question | |
523 | * @mask: the access requested | |
524 | * @nd: unused | |
525 | * | |
526 | * This is the important Smack hook. | |
527 | * | |
528 | * Returns 0 if access is permitted, -EACCES otherwise | |
529 | */ | |
530 | static int smack_inode_permission(struct inode *inode, int mask, | |
531 | struct nameidata *nd) | |
532 | { | |
533 | /* | |
534 | * No permission to check. Existence test. Yup, it's there. | |
535 | */ | |
536 | if (mask == 0) | |
537 | return 0; | |
538 | ||
539 | return smk_curacc(smk_of_inode(inode), mask); | |
540 | } | |
541 | ||
542 | /** | |
543 | * smack_inode_setattr - Smack check for setting attributes | |
544 | * @dentry: the object | |
545 | * @iattr: for the force flag | |
546 | * | |
547 | * Returns 0 if access is permitted, an error code otherwise | |
548 | */ | |
549 | static int smack_inode_setattr(struct dentry *dentry, struct iattr *iattr) | |
550 | { | |
551 | /* | |
552 | * Need to allow for clearing the setuid bit. | |
553 | */ | |
554 | if (iattr->ia_valid & ATTR_FORCE) | |
555 | return 0; | |
556 | ||
557 | return smk_curacc(smk_of_inode(dentry->d_inode), MAY_WRITE); | |
558 | } | |
559 | ||
560 | /** | |
561 | * smack_inode_getattr - Smack check for getting attributes | |
562 | * @mnt: unused | |
563 | * @dentry: the object | |
564 | * | |
565 | * Returns 0 if access is permitted, an error code otherwise | |
566 | */ | |
567 | static int smack_inode_getattr(struct vfsmount *mnt, struct dentry *dentry) | |
568 | { | |
569 | return smk_curacc(smk_of_inode(dentry->d_inode), MAY_READ); | |
570 | } | |
571 | ||
572 | /** | |
573 | * smack_inode_setxattr - Smack check for setting xattrs | |
574 | * @dentry: the object | |
575 | * @name: name of the attribute | |
576 | * @value: unused | |
577 | * @size: unused | |
578 | * @flags: unused | |
579 | * | |
580 | * This protects the Smack attribute explicitly. | |
581 | * | |
582 | * Returns 0 if access is permitted, an error code otherwise | |
583 | */ | |
584 | static int smack_inode_setxattr(struct dentry *dentry, char *name, | |
585 | void *value, size_t size, int flags) | |
586 | { | |
587 | if (!capable(CAP_MAC_ADMIN)) { | |
588 | if (strcmp(name, XATTR_NAME_SMACK) == 0 || | |
589 | strcmp(name, XATTR_NAME_SMACKIPIN) == 0 || | |
590 | strcmp(name, XATTR_NAME_SMACKIPOUT) == 0) | |
591 | return -EPERM; | |
592 | } | |
593 | ||
594 | return smk_curacc(smk_of_inode(dentry->d_inode), MAY_WRITE); | |
595 | } | |
596 | ||
597 | /** | |
598 | * smack_inode_post_setxattr - Apply the Smack update approved above | |
599 | * @dentry: object | |
600 | * @name: attribute name | |
601 | * @value: attribute value | |
602 | * @size: attribute size | |
603 | * @flags: unused | |
604 | * | |
605 | * Set the pointer in the inode blob to the entry found | |
606 | * in the master label list. | |
607 | */ | |
608 | static void smack_inode_post_setxattr(struct dentry *dentry, char *name, | |
609 | void *value, size_t size, int flags) | |
610 | { | |
611 | struct inode_smack *isp; | |
612 | char *nsp; | |
613 | ||
614 | /* | |
615 | * Not SMACK | |
616 | */ | |
617 | if (strcmp(name, XATTR_NAME_SMACK)) | |
618 | return; | |
619 | ||
620 | if (size >= SMK_LABELLEN) | |
621 | return; | |
622 | ||
623 | isp = dentry->d_inode->i_security; | |
624 | ||
625 | /* | |
626 | * No locking is done here. This is a pointer | |
627 | * assignment. | |
628 | */ | |
629 | nsp = smk_import(value, size); | |
630 | if (nsp != NULL) | |
631 | isp->smk_inode = nsp; | |
632 | else | |
633 | isp->smk_inode = smack_known_invalid.smk_known; | |
634 | ||
635 | return; | |
636 | } | |
637 | ||
638 | /* | |
639 | * smack_inode_getxattr - Smack check on getxattr | |
640 | * @dentry: the object | |
641 | * @name: unused | |
642 | * | |
643 | * Returns 0 if access is permitted, an error code otherwise | |
644 | */ | |
645 | static int smack_inode_getxattr(struct dentry *dentry, char *name) | |
646 | { | |
647 | return smk_curacc(smk_of_inode(dentry->d_inode), MAY_READ); | |
648 | } | |
649 | ||
650 | /* | |
651 | * smack_inode_removexattr - Smack check on removexattr | |
652 | * @dentry: the object | |
653 | * @name: name of the attribute | |
654 | * | |
655 | * Removing the Smack attribute requires CAP_MAC_ADMIN | |
656 | * | |
657 | * Returns 0 if access is permitted, an error code otherwise | |
658 | */ | |
659 | static int smack_inode_removexattr(struct dentry *dentry, char *name) | |
660 | { | |
661 | if (strcmp(name, XATTR_NAME_SMACK) == 0 && !capable(CAP_MAC_ADMIN)) | |
662 | return -EPERM; | |
663 | ||
664 | return smk_curacc(smk_of_inode(dentry->d_inode), MAY_WRITE); | |
665 | } | |
666 | ||
667 | /** | |
668 | * smack_inode_getsecurity - get smack xattrs | |
669 | * @inode: the object | |
670 | * @name: attribute name | |
671 | * @buffer: where to put the result | |
672 | * @size: size of the buffer | |
673 | * @err: unused | |
674 | * | |
675 | * Returns the size of the attribute or an error code | |
676 | */ | |
677 | static int smack_inode_getsecurity(const struct inode *inode, | |
678 | const char *name, void **buffer, | |
679 | bool alloc) | |
680 | { | |
681 | struct socket_smack *ssp; | |
682 | struct socket *sock; | |
683 | struct super_block *sbp; | |
684 | struct inode *ip = (struct inode *)inode; | |
685 | char *isp; | |
686 | int ilen; | |
687 | int rc = 0; | |
688 | ||
689 | if (strcmp(name, XATTR_SMACK_SUFFIX) == 0) { | |
690 | isp = smk_of_inode(inode); | |
691 | ilen = strlen(isp) + 1; | |
692 | *buffer = isp; | |
693 | return ilen; | |
694 | } | |
695 | ||
696 | /* | |
697 | * The rest of the Smack xattrs are only on sockets. | |
698 | */ | |
699 | sbp = ip->i_sb; | |
700 | if (sbp->s_magic != SOCKFS_MAGIC) | |
701 | return -EOPNOTSUPP; | |
702 | ||
703 | sock = SOCKET_I(ip); | |
2e1d146a | 704 | if (sock == NULL || sock->sk == NULL) |
e114e473 CS |
705 | return -EOPNOTSUPP; |
706 | ||
707 | ssp = sock->sk->sk_security; | |
708 | ||
709 | if (strcmp(name, XATTR_SMACK_IPIN) == 0) | |
710 | isp = ssp->smk_in; | |
711 | else if (strcmp(name, XATTR_SMACK_IPOUT) == 0) | |
712 | isp = ssp->smk_out; | |
713 | else | |
714 | return -EOPNOTSUPP; | |
715 | ||
716 | ilen = strlen(isp) + 1; | |
717 | if (rc == 0) { | |
718 | *buffer = isp; | |
719 | rc = ilen; | |
720 | } | |
721 | ||
722 | return rc; | |
723 | } | |
724 | ||
725 | ||
726 | /** | |
727 | * smack_inode_listsecurity - list the Smack attributes | |
728 | * @inode: the object | |
729 | * @buffer: where they go | |
730 | * @buffer_size: size of buffer | |
731 | * | |
732 | * Returns 0 on success, -EINVAL otherwise | |
733 | */ | |
734 | static int smack_inode_listsecurity(struct inode *inode, char *buffer, | |
735 | size_t buffer_size) | |
736 | { | |
737 | int len = strlen(XATTR_NAME_SMACK); | |
738 | ||
739 | if (buffer != NULL && len <= buffer_size) { | |
740 | memcpy(buffer, XATTR_NAME_SMACK, len); | |
741 | return len; | |
742 | } | |
743 | return -EINVAL; | |
744 | } | |
745 | ||
746 | /* | |
747 | * File Hooks | |
748 | */ | |
749 | ||
750 | /** | |
751 | * smack_file_permission - Smack check on file operations | |
752 | * @file: unused | |
753 | * @mask: unused | |
754 | * | |
755 | * Returns 0 | |
756 | * | |
757 | * Should access checks be done on each read or write? | |
758 | * UNICOS and SELinux say yes. | |
759 | * Trusted Solaris, Trusted Irix, and just about everyone else says no. | |
760 | * | |
761 | * I'll say no for now. Smack does not do the frequent | |
762 | * label changing that SELinux does. | |
763 | */ | |
764 | static int smack_file_permission(struct file *file, int mask) | |
765 | { | |
766 | return 0; | |
767 | } | |
768 | ||
769 | /** | |
770 | * smack_file_alloc_security - assign a file security blob | |
771 | * @file: the object | |
772 | * | |
773 | * The security blob for a file is a pointer to the master | |
774 | * label list, so no allocation is done. | |
775 | * | |
776 | * Returns 0 | |
777 | */ | |
778 | static int smack_file_alloc_security(struct file *file) | |
779 | { | |
780 | file->f_security = current->security; | |
781 | return 0; | |
782 | } | |
783 | ||
784 | /** | |
785 | * smack_file_free_security - clear a file security blob | |
786 | * @file: the object | |
787 | * | |
788 | * The security blob for a file is a pointer to the master | |
789 | * label list, so no memory is freed. | |
790 | */ | |
791 | static void smack_file_free_security(struct file *file) | |
792 | { | |
793 | file->f_security = NULL; | |
794 | } | |
795 | ||
796 | /** | |
797 | * smack_file_ioctl - Smack check on ioctls | |
798 | * @file: the object | |
799 | * @cmd: what to do | |
800 | * @arg: unused | |
801 | * | |
802 | * Relies heavily on the correct use of the ioctl command conventions. | |
803 | * | |
804 | * Returns 0 if allowed, error code otherwise | |
805 | */ | |
806 | static int smack_file_ioctl(struct file *file, unsigned int cmd, | |
807 | unsigned long arg) | |
808 | { | |
809 | int rc = 0; | |
810 | ||
811 | if (_IOC_DIR(cmd) & _IOC_WRITE) | |
812 | rc = smk_curacc(file->f_security, MAY_WRITE); | |
813 | ||
814 | if (rc == 0 && (_IOC_DIR(cmd) & _IOC_READ)) | |
815 | rc = smk_curacc(file->f_security, MAY_READ); | |
816 | ||
817 | return rc; | |
818 | } | |
819 | ||
820 | /** | |
821 | * smack_file_lock - Smack check on file locking | |
822 | * @file: the object | |
823 | * @cmd unused | |
824 | * | |
825 | * Returns 0 if current has write access, error code otherwise | |
826 | */ | |
827 | static int smack_file_lock(struct file *file, unsigned int cmd) | |
828 | { | |
829 | return smk_curacc(file->f_security, MAY_WRITE); | |
830 | } | |
831 | ||
832 | /** | |
833 | * smack_file_fcntl - Smack check on fcntl | |
834 | * @file: the object | |
835 | * @cmd: what action to check | |
836 | * @arg: unused | |
837 | * | |
838 | * Returns 0 if current has access, error code otherwise | |
839 | */ | |
840 | static int smack_file_fcntl(struct file *file, unsigned int cmd, | |
841 | unsigned long arg) | |
842 | { | |
843 | int rc; | |
844 | ||
845 | switch (cmd) { | |
846 | case F_DUPFD: | |
847 | case F_GETFD: | |
848 | case F_GETFL: | |
849 | case F_GETLK: | |
850 | case F_GETOWN: | |
851 | case F_GETSIG: | |
852 | rc = smk_curacc(file->f_security, MAY_READ); | |
853 | break; | |
854 | case F_SETFD: | |
855 | case F_SETFL: | |
856 | case F_SETLK: | |
857 | case F_SETLKW: | |
858 | case F_SETOWN: | |
859 | case F_SETSIG: | |
860 | rc = smk_curacc(file->f_security, MAY_WRITE); | |
861 | break; | |
862 | default: | |
863 | rc = smk_curacc(file->f_security, MAY_READWRITE); | |
864 | } | |
865 | ||
866 | return rc; | |
867 | } | |
868 | ||
869 | /** | |
870 | * smack_file_set_fowner - set the file security blob value | |
871 | * @file: object in question | |
872 | * | |
873 | * Returns 0 | |
874 | * Further research may be required on this one. | |
875 | */ | |
876 | static int smack_file_set_fowner(struct file *file) | |
877 | { | |
878 | file->f_security = current->security; | |
879 | return 0; | |
880 | } | |
881 | ||
882 | /** | |
883 | * smack_file_send_sigiotask - Smack on sigio | |
884 | * @tsk: The target task | |
885 | * @fown: the object the signal come from | |
886 | * @signum: unused | |
887 | * | |
888 | * Allow a privileged task to get signals even if it shouldn't | |
889 | * | |
890 | * Returns 0 if a subject with the object's smack could | |
891 | * write to the task, an error code otherwise. | |
892 | */ | |
893 | static int smack_file_send_sigiotask(struct task_struct *tsk, | |
894 | struct fown_struct *fown, int signum) | |
895 | { | |
896 | struct file *file; | |
897 | int rc; | |
898 | ||
899 | /* | |
900 | * struct fown_struct is never outside the context of a struct file | |
901 | */ | |
902 | file = container_of(fown, struct file, f_owner); | |
903 | rc = smk_access(file->f_security, tsk->security, MAY_WRITE); | |
904 | if (rc != 0 && __capable(tsk, CAP_MAC_OVERRIDE)) | |
905 | return 0; | |
906 | return rc; | |
907 | } | |
908 | ||
909 | /** | |
910 | * smack_file_receive - Smack file receive check | |
911 | * @file: the object | |
912 | * | |
913 | * Returns 0 if current has access, error code otherwise | |
914 | */ | |
915 | static int smack_file_receive(struct file *file) | |
916 | { | |
917 | int may = 0; | |
918 | ||
919 | /* | |
920 | * This code relies on bitmasks. | |
921 | */ | |
922 | if (file->f_mode & FMODE_READ) | |
923 | may = MAY_READ; | |
924 | if (file->f_mode & FMODE_WRITE) | |
925 | may |= MAY_WRITE; | |
926 | ||
927 | return smk_curacc(file->f_security, may); | |
928 | } | |
929 | ||
930 | /* | |
931 | * Task hooks | |
932 | */ | |
933 | ||
934 | /** | |
935 | * smack_task_alloc_security - "allocate" a task blob | |
936 | * @tsk: the task in need of a blob | |
937 | * | |
938 | * Smack isn't using copies of blobs. Everyone | |
939 | * points to an immutable list. No alloc required. | |
940 | * No data copy required. | |
941 | * | |
942 | * Always returns 0 | |
943 | */ | |
944 | static int smack_task_alloc_security(struct task_struct *tsk) | |
945 | { | |
946 | tsk->security = current->security; | |
947 | ||
948 | return 0; | |
949 | } | |
950 | ||
951 | /** | |
952 | * smack_task_free_security - "free" a task blob | |
953 | * @task: the task with the blob | |
954 | * | |
955 | * Smack isn't using copies of blobs. Everyone | |
956 | * points to an immutable list. The blobs never go away. | |
957 | * There is no leak here. | |
958 | */ | |
959 | static void smack_task_free_security(struct task_struct *task) | |
960 | { | |
961 | task->security = NULL; | |
962 | } | |
963 | ||
964 | /** | |
965 | * smack_task_setpgid - Smack check on setting pgid | |
966 | * @p: the task object | |
967 | * @pgid: unused | |
968 | * | |
969 | * Return 0 if write access is permitted | |
970 | */ | |
971 | static int smack_task_setpgid(struct task_struct *p, pid_t pgid) | |
972 | { | |
973 | return smk_curacc(p->security, MAY_WRITE); | |
974 | } | |
975 | ||
976 | /** | |
977 | * smack_task_getpgid - Smack access check for getpgid | |
978 | * @p: the object task | |
979 | * | |
980 | * Returns 0 if current can read the object task, error code otherwise | |
981 | */ | |
982 | static int smack_task_getpgid(struct task_struct *p) | |
983 | { | |
984 | return smk_curacc(p->security, MAY_READ); | |
985 | } | |
986 | ||
987 | /** | |
988 | * smack_task_getsid - Smack access check for getsid | |
989 | * @p: the object task | |
990 | * | |
991 | * Returns 0 if current can read the object task, error code otherwise | |
992 | */ | |
993 | static int smack_task_getsid(struct task_struct *p) | |
994 | { | |
995 | return smk_curacc(p->security, MAY_READ); | |
996 | } | |
997 | ||
998 | /** | |
999 | * smack_task_getsecid - get the secid of the task | |
1000 | * @p: the object task | |
1001 | * @secid: where to put the result | |
1002 | * | |
1003 | * Sets the secid to contain a u32 version of the smack label. | |
1004 | */ | |
1005 | static void smack_task_getsecid(struct task_struct *p, u32 *secid) | |
1006 | { | |
1007 | *secid = smack_to_secid(p->security); | |
1008 | } | |
1009 | ||
1010 | /** | |
1011 | * smack_task_setnice - Smack check on setting nice | |
1012 | * @p: the task object | |
1013 | * @nice: unused | |
1014 | * | |
1015 | * Return 0 if write access is permitted | |
1016 | */ | |
1017 | static int smack_task_setnice(struct task_struct *p, int nice) | |
1018 | { | |
1019 | return smk_curacc(p->security, MAY_WRITE); | |
1020 | } | |
1021 | ||
1022 | /** | |
1023 | * smack_task_setioprio - Smack check on setting ioprio | |
1024 | * @p: the task object | |
1025 | * @ioprio: unused | |
1026 | * | |
1027 | * Return 0 if write access is permitted | |
1028 | */ | |
1029 | static int smack_task_setioprio(struct task_struct *p, int ioprio) | |
1030 | { | |
1031 | return smk_curacc(p->security, MAY_WRITE); | |
1032 | } | |
1033 | ||
1034 | /** | |
1035 | * smack_task_getioprio - Smack check on reading ioprio | |
1036 | * @p: the task object | |
1037 | * | |
1038 | * Return 0 if read access is permitted | |
1039 | */ | |
1040 | static int smack_task_getioprio(struct task_struct *p) | |
1041 | { | |
1042 | return smk_curacc(p->security, MAY_READ); | |
1043 | } | |
1044 | ||
1045 | /** | |
1046 | * smack_task_setscheduler - Smack check on setting scheduler | |
1047 | * @p: the task object | |
1048 | * @policy: unused | |
1049 | * @lp: unused | |
1050 | * | |
1051 | * Return 0 if read access is permitted | |
1052 | */ | |
1053 | static int smack_task_setscheduler(struct task_struct *p, int policy, | |
1054 | struct sched_param *lp) | |
1055 | { | |
1056 | return smk_curacc(p->security, MAY_WRITE); | |
1057 | } | |
1058 | ||
1059 | /** | |
1060 | * smack_task_getscheduler - Smack check on reading scheduler | |
1061 | * @p: the task object | |
1062 | * | |
1063 | * Return 0 if read access is permitted | |
1064 | */ | |
1065 | static int smack_task_getscheduler(struct task_struct *p) | |
1066 | { | |
1067 | return smk_curacc(p->security, MAY_READ); | |
1068 | } | |
1069 | ||
1070 | /** | |
1071 | * smack_task_movememory - Smack check on moving memory | |
1072 | * @p: the task object | |
1073 | * | |
1074 | * Return 0 if write access is permitted | |
1075 | */ | |
1076 | static int smack_task_movememory(struct task_struct *p) | |
1077 | { | |
1078 | return smk_curacc(p->security, MAY_WRITE); | |
1079 | } | |
1080 | ||
1081 | /** | |
1082 | * smack_task_kill - Smack check on signal delivery | |
1083 | * @p: the task object | |
1084 | * @info: unused | |
1085 | * @sig: unused | |
1086 | * @secid: identifies the smack to use in lieu of current's | |
1087 | * | |
1088 | * Return 0 if write access is permitted | |
1089 | * | |
1090 | * The secid behavior is an artifact of an SELinux hack | |
1091 | * in the USB code. Someday it may go away. | |
1092 | */ | |
1093 | static int smack_task_kill(struct task_struct *p, struct siginfo *info, | |
1094 | int sig, u32 secid) | |
1095 | { | |
1096 | /* | |
1097 | * Special cases where signals really ought to go through | |
1098 | * in spite of policy. Stephen Smalley suggests it may | |
1099 | * make sense to change the caller so that it doesn't | |
1100 | * bother with the LSM hook in these cases. | |
1101 | */ | |
1102 | if (info != SEND_SIG_NOINFO && | |
1103 | (is_si_special(info) || SI_FROMKERNEL(info))) | |
1104 | return 0; | |
1105 | /* | |
1106 | * Sending a signal requires that the sender | |
1107 | * can write the receiver. | |
1108 | */ | |
1109 | if (secid == 0) | |
1110 | return smk_curacc(p->security, MAY_WRITE); | |
1111 | /* | |
1112 | * If the secid isn't 0 we're dealing with some USB IO | |
1113 | * specific behavior. This is not clean. For one thing | |
1114 | * we can't take privilege into account. | |
1115 | */ | |
1116 | return smk_access(smack_from_secid(secid), p->security, MAY_WRITE); | |
1117 | } | |
1118 | ||
1119 | /** | |
1120 | * smack_task_wait - Smack access check for waiting | |
1121 | * @p: task to wait for | |
1122 | * | |
1123 | * Returns 0 if current can wait for p, error code otherwise | |
1124 | */ | |
1125 | static int smack_task_wait(struct task_struct *p) | |
1126 | { | |
1127 | int rc; | |
1128 | ||
1129 | rc = smk_access(current->security, p->security, MAY_WRITE); | |
1130 | if (rc == 0) | |
1131 | return 0; | |
1132 | ||
1133 | /* | |
1134 | * Allow the operation to succeed if either task | |
1135 | * has privilege to perform operations that might | |
1136 | * account for the smack labels having gotten to | |
1137 | * be different in the first place. | |
1138 | * | |
1139 | * This breaks the strict subjet/object access | |
1140 | * control ideal, taking the object's privilege | |
1141 | * state into account in the decision as well as | |
1142 | * the smack value. | |
1143 | */ | |
1144 | if (capable(CAP_MAC_OVERRIDE) || __capable(p, CAP_MAC_OVERRIDE)) | |
1145 | return 0; | |
1146 | ||
1147 | return rc; | |
1148 | } | |
1149 | ||
1150 | /** | |
1151 | * smack_task_to_inode - copy task smack into the inode blob | |
1152 | * @p: task to copy from | |
1153 | * inode: inode to copy to | |
1154 | * | |
1155 | * Sets the smack pointer in the inode security blob | |
1156 | */ | |
1157 | static void smack_task_to_inode(struct task_struct *p, struct inode *inode) | |
1158 | { | |
1159 | struct inode_smack *isp = inode->i_security; | |
1160 | isp->smk_inode = p->security; | |
1161 | } | |
1162 | ||
1163 | /* | |
1164 | * Socket hooks. | |
1165 | */ | |
1166 | ||
1167 | /** | |
1168 | * smack_sk_alloc_security - Allocate a socket blob | |
1169 | * @sk: the socket | |
1170 | * @family: unused | |
1171 | * @priority: memory allocation priority | |
1172 | * | |
1173 | * Assign Smack pointers to current | |
1174 | * | |
1175 | * Returns 0 on success, -ENOMEM is there's no memory | |
1176 | */ | |
1177 | static int smack_sk_alloc_security(struct sock *sk, int family, gfp_t gfp_flags) | |
1178 | { | |
1179 | char *csp = current->security; | |
1180 | struct socket_smack *ssp; | |
1181 | ||
1182 | ssp = kzalloc(sizeof(struct socket_smack), gfp_flags); | |
1183 | if (ssp == NULL) | |
1184 | return -ENOMEM; | |
1185 | ||
1186 | ssp->smk_in = csp; | |
1187 | ssp->smk_out = csp; | |
1188 | ssp->smk_packet[0] = '\0'; | |
1189 | ||
1190 | sk->sk_security = ssp; | |
1191 | ||
1192 | return 0; | |
1193 | } | |
1194 | ||
1195 | /** | |
1196 | * smack_sk_free_security - Free a socket blob | |
1197 | * @sk: the socket | |
1198 | * | |
1199 | * Clears the blob pointer | |
1200 | */ | |
1201 | static void smack_sk_free_security(struct sock *sk) | |
1202 | { | |
1203 | kfree(sk->sk_security); | |
1204 | } | |
1205 | ||
1206 | /** | |
1207 | * smack_set_catset - convert a capset to netlabel mls categories | |
1208 | * @catset: the Smack categories | |
1209 | * @sap: where to put the netlabel categories | |
1210 | * | |
1211 | * Allocates and fills attr.mls.cat | |
1212 | */ | |
1213 | static void smack_set_catset(char *catset, struct netlbl_lsm_secattr *sap) | |
1214 | { | |
1215 | unsigned char *cp; | |
1216 | unsigned char m; | |
1217 | int cat; | |
1218 | int rc; | |
1219 | int byte; | |
1220 | ||
1221 | if (catset == 0) | |
1222 | return; | |
1223 | ||
1224 | sap->flags |= NETLBL_SECATTR_MLS_CAT; | |
1225 | sap->attr.mls.cat = netlbl_secattr_catmap_alloc(GFP_ATOMIC); | |
1226 | sap->attr.mls.cat->startbit = 0; | |
1227 | ||
1228 | for (cat = 1, cp = catset, byte = 0; byte < SMK_LABELLEN; cp++, byte++) | |
1229 | for (m = 0x80; m != 0; m >>= 1, cat++) { | |
1230 | if ((m & *cp) == 0) | |
1231 | continue; | |
1232 | rc = netlbl_secattr_catmap_setbit(sap->attr.mls.cat, | |
1233 | cat, GFP_ATOMIC); | |
1234 | } | |
1235 | } | |
1236 | ||
1237 | /** | |
1238 | * smack_to_secattr - fill a secattr from a smack value | |
1239 | * @smack: the smack value | |
1240 | * @nlsp: where the result goes | |
1241 | * | |
1242 | * Casey says that CIPSO is good enough for now. | |
1243 | * It can be used to effect. | |
1244 | * It can also be abused to effect when necessary. | |
1245 | * Appologies to the TSIG group in general and GW in particular. | |
1246 | */ | |
1247 | static void smack_to_secattr(char *smack, struct netlbl_lsm_secattr *nlsp) | |
1248 | { | |
1249 | struct smack_cipso cipso; | |
1250 | int rc; | |
1251 | ||
1252 | switch (smack_net_nltype) { | |
1253 | case NETLBL_NLTYPE_CIPSOV4: | |
1254 | nlsp->domain = NULL; | |
1255 | nlsp->flags = NETLBL_SECATTR_DOMAIN; | |
1256 | nlsp->flags |= NETLBL_SECATTR_MLS_LVL; | |
1257 | ||
1258 | rc = smack_to_cipso(smack, &cipso); | |
1259 | if (rc == 0) { | |
1260 | nlsp->attr.mls.lvl = cipso.smk_level; | |
1261 | smack_set_catset(cipso.smk_catset, nlsp); | |
1262 | } else { | |
1263 | nlsp->attr.mls.lvl = smack_cipso_direct; | |
1264 | smack_set_catset(smack, nlsp); | |
1265 | } | |
1266 | break; | |
1267 | default: | |
1268 | break; | |
1269 | } | |
1270 | } | |
1271 | ||
1272 | /** | |
1273 | * smack_netlabel - Set the secattr on a socket | |
1274 | * @sk: the socket | |
1275 | * | |
1276 | * Convert the outbound smack value (smk_out) to a | |
1277 | * secattr and attach it to the socket. | |
1278 | * | |
1279 | * Returns 0 on success or an error code | |
1280 | */ | |
1281 | static int smack_netlabel(struct sock *sk) | |
1282 | { | |
2e1d146a | 1283 | struct socket_smack *ssp; |
e114e473 CS |
1284 | struct netlbl_lsm_secattr secattr; |
1285 | int rc = 0; | |
1286 | ||
2e1d146a | 1287 | ssp = sk->sk_security; |
e114e473 CS |
1288 | netlbl_secattr_init(&secattr); |
1289 | smack_to_secattr(ssp->smk_out, &secattr); | |
1290 | if (secattr.flags != NETLBL_SECATTR_NONE) | |
1291 | rc = netlbl_sock_setattr(sk, &secattr); | |
1292 | ||
1293 | netlbl_secattr_destroy(&secattr); | |
1294 | return rc; | |
1295 | } | |
1296 | ||
1297 | /** | |
1298 | * smack_inode_setsecurity - set smack xattrs | |
1299 | * @inode: the object | |
1300 | * @name: attribute name | |
1301 | * @value: attribute value | |
1302 | * @size: size of the attribute | |
1303 | * @flags: unused | |
1304 | * | |
1305 | * Sets the named attribute in the appropriate blob | |
1306 | * | |
1307 | * Returns 0 on success, or an error code | |
1308 | */ | |
1309 | static int smack_inode_setsecurity(struct inode *inode, const char *name, | |
1310 | const void *value, size_t size, int flags) | |
1311 | { | |
1312 | char *sp; | |
1313 | struct inode_smack *nsp = inode->i_security; | |
1314 | struct socket_smack *ssp; | |
1315 | struct socket *sock; | |
1316 | ||
1317 | if (value == NULL || size > SMK_LABELLEN) | |
1318 | return -EACCES; | |
1319 | ||
1320 | sp = smk_import(value, size); | |
1321 | if (sp == NULL) | |
1322 | return -EINVAL; | |
1323 | ||
1324 | if (strcmp(name, XATTR_SMACK_SUFFIX) == 0) { | |
1325 | nsp->smk_inode = sp; | |
1326 | return 0; | |
1327 | } | |
1328 | /* | |
1329 | * The rest of the Smack xattrs are only on sockets. | |
1330 | */ | |
1331 | if (inode->i_sb->s_magic != SOCKFS_MAGIC) | |
1332 | return -EOPNOTSUPP; | |
1333 | ||
1334 | sock = SOCKET_I(inode); | |
2e1d146a | 1335 | if (sock == NULL || sock->sk == NULL) |
e114e473 CS |
1336 | return -EOPNOTSUPP; |
1337 | ||
1338 | ssp = sock->sk->sk_security; | |
1339 | ||
1340 | if (strcmp(name, XATTR_SMACK_IPIN) == 0) | |
1341 | ssp->smk_in = sp; | |
1342 | else if (strcmp(name, XATTR_SMACK_IPOUT) == 0) { | |
1343 | ssp->smk_out = sp; | |
1344 | return smack_netlabel(sock->sk); | |
1345 | } else | |
1346 | return -EOPNOTSUPP; | |
1347 | ||
1348 | return 0; | |
1349 | } | |
1350 | ||
1351 | /** | |
1352 | * smack_socket_post_create - finish socket setup | |
1353 | * @sock: the socket | |
1354 | * @family: protocol family | |
1355 | * @type: unused | |
1356 | * @protocol: unused | |
1357 | * @kern: unused | |
1358 | * | |
1359 | * Sets the netlabel information on the socket | |
1360 | * | |
1361 | * Returns 0 on success, and error code otherwise | |
1362 | */ | |
1363 | static int smack_socket_post_create(struct socket *sock, int family, | |
1364 | int type, int protocol, int kern) | |
1365 | { | |
2e1d146a | 1366 | if (family != PF_INET || sock->sk == NULL) |
e114e473 CS |
1367 | return 0; |
1368 | /* | |
1369 | * Set the outbound netlbl. | |
1370 | */ | |
1371 | return smack_netlabel(sock->sk); | |
1372 | } | |
1373 | ||
1374 | /** | |
1375 | * smack_flags_to_may - convert S_ to MAY_ values | |
1376 | * @flags: the S_ value | |
1377 | * | |
1378 | * Returns the equivalent MAY_ value | |
1379 | */ | |
1380 | static int smack_flags_to_may(int flags) | |
1381 | { | |
1382 | int may = 0; | |
1383 | ||
1384 | if (flags & S_IRUGO) | |
1385 | may |= MAY_READ; | |
1386 | if (flags & S_IWUGO) | |
1387 | may |= MAY_WRITE; | |
1388 | if (flags & S_IXUGO) | |
1389 | may |= MAY_EXEC; | |
1390 | ||
1391 | return may; | |
1392 | } | |
1393 | ||
1394 | /** | |
1395 | * smack_msg_msg_alloc_security - Set the security blob for msg_msg | |
1396 | * @msg: the object | |
1397 | * | |
1398 | * Returns 0 | |
1399 | */ | |
1400 | static int smack_msg_msg_alloc_security(struct msg_msg *msg) | |
1401 | { | |
1402 | msg->security = current->security; | |
1403 | return 0; | |
1404 | } | |
1405 | ||
1406 | /** | |
1407 | * smack_msg_msg_free_security - Clear the security blob for msg_msg | |
1408 | * @msg: the object | |
1409 | * | |
1410 | * Clears the blob pointer | |
1411 | */ | |
1412 | static void smack_msg_msg_free_security(struct msg_msg *msg) | |
1413 | { | |
1414 | msg->security = NULL; | |
1415 | } | |
1416 | ||
1417 | /** | |
1418 | * smack_of_shm - the smack pointer for the shm | |
1419 | * @shp: the object | |
1420 | * | |
1421 | * Returns a pointer to the smack value | |
1422 | */ | |
1423 | static char *smack_of_shm(struct shmid_kernel *shp) | |
1424 | { | |
1425 | return (char *)shp->shm_perm.security; | |
1426 | } | |
1427 | ||
1428 | /** | |
1429 | * smack_shm_alloc_security - Set the security blob for shm | |
1430 | * @shp: the object | |
1431 | * | |
1432 | * Returns 0 | |
1433 | */ | |
1434 | static int smack_shm_alloc_security(struct shmid_kernel *shp) | |
1435 | { | |
1436 | struct kern_ipc_perm *isp = &shp->shm_perm; | |
1437 | ||
1438 | isp->security = current->security; | |
1439 | return 0; | |
1440 | } | |
1441 | ||
1442 | /** | |
1443 | * smack_shm_free_security - Clear the security blob for shm | |
1444 | * @shp: the object | |
1445 | * | |
1446 | * Clears the blob pointer | |
1447 | */ | |
1448 | static void smack_shm_free_security(struct shmid_kernel *shp) | |
1449 | { | |
1450 | struct kern_ipc_perm *isp = &shp->shm_perm; | |
1451 | ||
1452 | isp->security = NULL; | |
1453 | } | |
1454 | ||
1455 | /** | |
1456 | * smack_shm_associate - Smack access check for shm | |
1457 | * @shp: the object | |
1458 | * @shmflg: access requested | |
1459 | * | |
1460 | * Returns 0 if current has the requested access, error code otherwise | |
1461 | */ | |
1462 | static int smack_shm_associate(struct shmid_kernel *shp, int shmflg) | |
1463 | { | |
1464 | char *ssp = smack_of_shm(shp); | |
1465 | int may; | |
1466 | ||
1467 | may = smack_flags_to_may(shmflg); | |
1468 | return smk_curacc(ssp, may); | |
1469 | } | |
1470 | ||
1471 | /** | |
1472 | * smack_shm_shmctl - Smack access check for shm | |
1473 | * @shp: the object | |
1474 | * @cmd: what it wants to do | |
1475 | * | |
1476 | * Returns 0 if current has the requested access, error code otherwise | |
1477 | */ | |
1478 | static int smack_shm_shmctl(struct shmid_kernel *shp, int cmd) | |
1479 | { | |
1480 | char *ssp = smack_of_shm(shp); | |
1481 | int may; | |
1482 | ||
1483 | switch (cmd) { | |
1484 | case IPC_STAT: | |
1485 | case SHM_STAT: | |
1486 | may = MAY_READ; | |
1487 | break; | |
1488 | case IPC_SET: | |
1489 | case SHM_LOCK: | |
1490 | case SHM_UNLOCK: | |
1491 | case IPC_RMID: | |
1492 | may = MAY_READWRITE; | |
1493 | break; | |
1494 | case IPC_INFO: | |
1495 | case SHM_INFO: | |
1496 | /* | |
1497 | * System level information. | |
1498 | */ | |
1499 | return 0; | |
1500 | default: | |
1501 | return -EINVAL; | |
1502 | } | |
1503 | ||
1504 | return smk_curacc(ssp, may); | |
1505 | } | |
1506 | ||
1507 | /** | |
1508 | * smack_shm_shmat - Smack access for shmat | |
1509 | * @shp: the object | |
1510 | * @shmaddr: unused | |
1511 | * @shmflg: access requested | |
1512 | * | |
1513 | * Returns 0 if current has the requested access, error code otherwise | |
1514 | */ | |
1515 | static int smack_shm_shmat(struct shmid_kernel *shp, char __user *shmaddr, | |
1516 | int shmflg) | |
1517 | { | |
1518 | char *ssp = smack_of_shm(shp); | |
1519 | int may; | |
1520 | ||
1521 | may = smack_flags_to_may(shmflg); | |
1522 | return smk_curacc(ssp, may); | |
1523 | } | |
1524 | ||
1525 | /** | |
1526 | * smack_of_sem - the smack pointer for the sem | |
1527 | * @sma: the object | |
1528 | * | |
1529 | * Returns a pointer to the smack value | |
1530 | */ | |
1531 | static char *smack_of_sem(struct sem_array *sma) | |
1532 | { | |
1533 | return (char *)sma->sem_perm.security; | |
1534 | } | |
1535 | ||
1536 | /** | |
1537 | * smack_sem_alloc_security - Set the security blob for sem | |
1538 | * @sma: the object | |
1539 | * | |
1540 | * Returns 0 | |
1541 | */ | |
1542 | static int smack_sem_alloc_security(struct sem_array *sma) | |
1543 | { | |
1544 | struct kern_ipc_perm *isp = &sma->sem_perm; | |
1545 | ||
1546 | isp->security = current->security; | |
1547 | return 0; | |
1548 | } | |
1549 | ||
1550 | /** | |
1551 | * smack_sem_free_security - Clear the security blob for sem | |
1552 | * @sma: the object | |
1553 | * | |
1554 | * Clears the blob pointer | |
1555 | */ | |
1556 | static void smack_sem_free_security(struct sem_array *sma) | |
1557 | { | |
1558 | struct kern_ipc_perm *isp = &sma->sem_perm; | |
1559 | ||
1560 | isp->security = NULL; | |
1561 | } | |
1562 | ||
1563 | /** | |
1564 | * smack_sem_associate - Smack access check for sem | |
1565 | * @sma: the object | |
1566 | * @semflg: access requested | |
1567 | * | |
1568 | * Returns 0 if current has the requested access, error code otherwise | |
1569 | */ | |
1570 | static int smack_sem_associate(struct sem_array *sma, int semflg) | |
1571 | { | |
1572 | char *ssp = smack_of_sem(sma); | |
1573 | int may; | |
1574 | ||
1575 | may = smack_flags_to_may(semflg); | |
1576 | return smk_curacc(ssp, may); | |
1577 | } | |
1578 | ||
1579 | /** | |
1580 | * smack_sem_shmctl - Smack access check for sem | |
1581 | * @sma: the object | |
1582 | * @cmd: what it wants to do | |
1583 | * | |
1584 | * Returns 0 if current has the requested access, error code otherwise | |
1585 | */ | |
1586 | static int smack_sem_semctl(struct sem_array *sma, int cmd) | |
1587 | { | |
1588 | char *ssp = smack_of_sem(sma); | |
1589 | int may; | |
1590 | ||
1591 | switch (cmd) { | |
1592 | case GETPID: | |
1593 | case GETNCNT: | |
1594 | case GETZCNT: | |
1595 | case GETVAL: | |
1596 | case GETALL: | |
1597 | case IPC_STAT: | |
1598 | case SEM_STAT: | |
1599 | may = MAY_READ; | |
1600 | break; | |
1601 | case SETVAL: | |
1602 | case SETALL: | |
1603 | case IPC_RMID: | |
1604 | case IPC_SET: | |
1605 | may = MAY_READWRITE; | |
1606 | break; | |
1607 | case IPC_INFO: | |
1608 | case SEM_INFO: | |
1609 | /* | |
1610 | * System level information | |
1611 | */ | |
1612 | return 0; | |
1613 | default: | |
1614 | return -EINVAL; | |
1615 | } | |
1616 | ||
1617 | return smk_curacc(ssp, may); | |
1618 | } | |
1619 | ||
1620 | /** | |
1621 | * smack_sem_semop - Smack checks of semaphore operations | |
1622 | * @sma: the object | |
1623 | * @sops: unused | |
1624 | * @nsops: unused | |
1625 | * @alter: unused | |
1626 | * | |
1627 | * Treated as read and write in all cases. | |
1628 | * | |
1629 | * Returns 0 if access is allowed, error code otherwise | |
1630 | */ | |
1631 | static int smack_sem_semop(struct sem_array *sma, struct sembuf *sops, | |
1632 | unsigned nsops, int alter) | |
1633 | { | |
1634 | char *ssp = smack_of_sem(sma); | |
1635 | ||
1636 | return smk_curacc(ssp, MAY_READWRITE); | |
1637 | } | |
1638 | ||
1639 | /** | |
1640 | * smack_msg_alloc_security - Set the security blob for msg | |
1641 | * @msq: the object | |
1642 | * | |
1643 | * Returns 0 | |
1644 | */ | |
1645 | static int smack_msg_queue_alloc_security(struct msg_queue *msq) | |
1646 | { | |
1647 | struct kern_ipc_perm *kisp = &msq->q_perm; | |
1648 | ||
1649 | kisp->security = current->security; | |
1650 | return 0; | |
1651 | } | |
1652 | ||
1653 | /** | |
1654 | * smack_msg_free_security - Clear the security blob for msg | |
1655 | * @msq: the object | |
1656 | * | |
1657 | * Clears the blob pointer | |
1658 | */ | |
1659 | static void smack_msg_queue_free_security(struct msg_queue *msq) | |
1660 | { | |
1661 | struct kern_ipc_perm *kisp = &msq->q_perm; | |
1662 | ||
1663 | kisp->security = NULL; | |
1664 | } | |
1665 | ||
1666 | /** | |
1667 | * smack_of_msq - the smack pointer for the msq | |
1668 | * @msq: the object | |
1669 | * | |
1670 | * Returns a pointer to the smack value | |
1671 | */ | |
1672 | static char *smack_of_msq(struct msg_queue *msq) | |
1673 | { | |
1674 | return (char *)msq->q_perm.security; | |
1675 | } | |
1676 | ||
1677 | /** | |
1678 | * smack_msg_queue_associate - Smack access check for msg_queue | |
1679 | * @msq: the object | |
1680 | * @msqflg: access requested | |
1681 | * | |
1682 | * Returns 0 if current has the requested access, error code otherwise | |
1683 | */ | |
1684 | static int smack_msg_queue_associate(struct msg_queue *msq, int msqflg) | |
1685 | { | |
1686 | char *msp = smack_of_msq(msq); | |
1687 | int may; | |
1688 | ||
1689 | may = smack_flags_to_may(msqflg); | |
1690 | return smk_curacc(msp, may); | |
1691 | } | |
1692 | ||
1693 | /** | |
1694 | * smack_msg_queue_msgctl - Smack access check for msg_queue | |
1695 | * @msq: the object | |
1696 | * @cmd: what it wants to do | |
1697 | * | |
1698 | * Returns 0 if current has the requested access, error code otherwise | |
1699 | */ | |
1700 | static int smack_msg_queue_msgctl(struct msg_queue *msq, int cmd) | |
1701 | { | |
1702 | char *msp = smack_of_msq(msq); | |
1703 | int may; | |
1704 | ||
1705 | switch (cmd) { | |
1706 | case IPC_STAT: | |
1707 | case MSG_STAT: | |
1708 | may = MAY_READ; | |
1709 | break; | |
1710 | case IPC_SET: | |
1711 | case IPC_RMID: | |
1712 | may = MAY_READWRITE; | |
1713 | break; | |
1714 | case IPC_INFO: | |
1715 | case MSG_INFO: | |
1716 | /* | |
1717 | * System level information | |
1718 | */ | |
1719 | return 0; | |
1720 | default: | |
1721 | return -EINVAL; | |
1722 | } | |
1723 | ||
1724 | return smk_curacc(msp, may); | |
1725 | } | |
1726 | ||
1727 | /** | |
1728 | * smack_msg_queue_msgsnd - Smack access check for msg_queue | |
1729 | * @msq: the object | |
1730 | * @msg: unused | |
1731 | * @msqflg: access requested | |
1732 | * | |
1733 | * Returns 0 if current has the requested access, error code otherwise | |
1734 | */ | |
1735 | static int smack_msg_queue_msgsnd(struct msg_queue *msq, struct msg_msg *msg, | |
1736 | int msqflg) | |
1737 | { | |
1738 | char *msp = smack_of_msq(msq); | |
1739 | int rc; | |
1740 | ||
1741 | rc = smack_flags_to_may(msqflg); | |
1742 | return smk_curacc(msp, rc); | |
1743 | } | |
1744 | ||
1745 | /** | |
1746 | * smack_msg_queue_msgsnd - Smack access check for msg_queue | |
1747 | * @msq: the object | |
1748 | * @msg: unused | |
1749 | * @target: unused | |
1750 | * @type: unused | |
1751 | * @mode: unused | |
1752 | * | |
1753 | * Returns 0 if current has read and write access, error code otherwise | |
1754 | */ | |
1755 | static int smack_msg_queue_msgrcv(struct msg_queue *msq, struct msg_msg *msg, | |
1756 | struct task_struct *target, long type, int mode) | |
1757 | { | |
1758 | char *msp = smack_of_msq(msq); | |
1759 | ||
1760 | return smk_curacc(msp, MAY_READWRITE); | |
1761 | } | |
1762 | ||
1763 | /** | |
1764 | * smack_ipc_permission - Smack access for ipc_permission() | |
1765 | * @ipp: the object permissions | |
1766 | * @flag: access requested | |
1767 | * | |
1768 | * Returns 0 if current has read and write access, error code otherwise | |
1769 | */ | |
1770 | static int smack_ipc_permission(struct kern_ipc_perm *ipp, short flag) | |
1771 | { | |
1772 | char *isp = ipp->security; | |
1773 | int may; | |
1774 | ||
1775 | may = smack_flags_to_may(flag); | |
1776 | return smk_curacc(isp, may); | |
1777 | } | |
1778 | ||
1779 | /** | |
1780 | * smack_d_instantiate - Make sure the blob is correct on an inode | |
1781 | * @opt_dentry: unused | |
1782 | * @inode: the object | |
1783 | * | |
1784 | * Set the inode's security blob if it hasn't been done already. | |
1785 | */ | |
1786 | static void smack_d_instantiate(struct dentry *opt_dentry, struct inode *inode) | |
1787 | { | |
1788 | struct super_block *sbp; | |
1789 | struct superblock_smack *sbsp; | |
1790 | struct inode_smack *isp; | |
1791 | char *csp = current->security; | |
1792 | char *fetched; | |
1793 | char *final; | |
1794 | struct dentry *dp; | |
1795 | ||
1796 | if (inode == NULL) | |
1797 | return; | |
1798 | ||
1799 | isp = inode->i_security; | |
1800 | ||
1801 | mutex_lock(&isp->smk_lock); | |
1802 | /* | |
1803 | * If the inode is already instantiated | |
1804 | * take the quick way out | |
1805 | */ | |
1806 | if (isp->smk_flags & SMK_INODE_INSTANT) | |
1807 | goto unlockandout; | |
1808 | ||
1809 | sbp = inode->i_sb; | |
1810 | sbsp = sbp->s_security; | |
1811 | /* | |
1812 | * We're going to use the superblock default label | |
1813 | * if there's no label on the file. | |
1814 | */ | |
1815 | final = sbsp->smk_default; | |
1816 | ||
1817 | /* | |
1818 | * This is pretty hackish. | |
1819 | * Casey says that we shouldn't have to do | |
1820 | * file system specific code, but it does help | |
1821 | * with keeping it simple. | |
1822 | */ | |
1823 | switch (sbp->s_magic) { | |
1824 | case SMACK_MAGIC: | |
1825 | /* | |
1826 | * Casey says that it's a little embarassing | |
1827 | * that the smack file system doesn't do | |
1828 | * extended attributes. | |
1829 | */ | |
1830 | final = smack_known_star.smk_known; | |
1831 | break; | |
1832 | case PIPEFS_MAGIC: | |
1833 | /* | |
1834 | * Casey says pipes are easy (?) | |
1835 | */ | |
1836 | final = smack_known_star.smk_known; | |
1837 | break; | |
1838 | case DEVPTS_SUPER_MAGIC: | |
1839 | /* | |
1840 | * devpts seems content with the label of the task. | |
1841 | * Programs that change smack have to treat the | |
1842 | * pty with respect. | |
1843 | */ | |
1844 | final = csp; | |
1845 | break; | |
1846 | case SOCKFS_MAGIC: | |
1847 | /* | |
1848 | * Casey says sockets get the smack of the task. | |
1849 | */ | |
1850 | final = csp; | |
1851 | break; | |
1852 | case PROC_SUPER_MAGIC: | |
1853 | /* | |
1854 | * Casey says procfs appears not to care. | |
1855 | * The superblock default suffices. | |
1856 | */ | |
1857 | break; | |
1858 | case TMPFS_MAGIC: | |
1859 | /* | |
1860 | * Device labels should come from the filesystem, | |
1861 | * but watch out, because they're volitile, | |
1862 | * getting recreated on every reboot. | |
1863 | */ | |
1864 | final = smack_known_star.smk_known; | |
1865 | /* | |
1866 | * No break. | |
1867 | * | |
1868 | * If a smack value has been set we want to use it, | |
1869 | * but since tmpfs isn't giving us the opportunity | |
1870 | * to set mount options simulate setting the | |
1871 | * superblock default. | |
1872 | */ | |
1873 | default: | |
1874 | /* | |
1875 | * This isn't an understood special case. | |
1876 | * Get the value from the xattr. | |
1877 | * | |
1878 | * No xattr support means, alas, no SMACK label. | |
1879 | * Use the aforeapplied default. | |
1880 | * It would be curious if the label of the task | |
1881 | * does not match that assigned. | |
1882 | */ | |
1883 | if (inode->i_op->getxattr == NULL) | |
1884 | break; | |
1885 | /* | |
1886 | * Get the dentry for xattr. | |
1887 | */ | |
1888 | if (opt_dentry == NULL) { | |
1889 | dp = d_find_alias(inode); | |
1890 | if (dp == NULL) | |
1891 | break; | |
1892 | } else { | |
1893 | dp = dget(opt_dentry); | |
1894 | if (dp == NULL) | |
1895 | break; | |
1896 | } | |
1897 | ||
1898 | fetched = smk_fetch(inode, dp); | |
1899 | if (fetched != NULL) | |
1900 | final = fetched; | |
1901 | ||
1902 | dput(dp); | |
1903 | break; | |
1904 | } | |
1905 | ||
1906 | if (final == NULL) | |
1907 | isp->smk_inode = csp; | |
1908 | else | |
1909 | isp->smk_inode = final; | |
1910 | ||
1911 | isp->smk_flags |= SMK_INODE_INSTANT; | |
1912 | ||
1913 | unlockandout: | |
1914 | mutex_unlock(&isp->smk_lock); | |
1915 | return; | |
1916 | } | |
1917 | ||
1918 | /** | |
1919 | * smack_getprocattr - Smack process attribute access | |
1920 | * @p: the object task | |
1921 | * @name: the name of the attribute in /proc/.../attr | |
1922 | * @value: where to put the result | |
1923 | * | |
1924 | * Places a copy of the task Smack into value | |
1925 | * | |
1926 | * Returns the length of the smack label or an error code | |
1927 | */ | |
1928 | static int smack_getprocattr(struct task_struct *p, char *name, char **value) | |
1929 | { | |
1930 | char *cp; | |
1931 | int slen; | |
1932 | ||
1933 | if (strcmp(name, "current") != 0) | |
1934 | return -EINVAL; | |
1935 | ||
1936 | cp = kstrdup(p->security, GFP_KERNEL); | |
1937 | if (cp == NULL) | |
1938 | return -ENOMEM; | |
1939 | ||
1940 | slen = strlen(cp); | |
1941 | *value = cp; | |
1942 | return slen; | |
1943 | } | |
1944 | ||
1945 | /** | |
1946 | * smack_setprocattr - Smack process attribute setting | |
1947 | * @p: the object task | |
1948 | * @name: the name of the attribute in /proc/.../attr | |
1949 | * @value: the value to set | |
1950 | * @size: the size of the value | |
1951 | * | |
1952 | * Sets the Smack value of the task. Only setting self | |
1953 | * is permitted and only with privilege | |
1954 | * | |
1955 | * Returns the length of the smack label or an error code | |
1956 | */ | |
1957 | static int smack_setprocattr(struct task_struct *p, char *name, | |
1958 | void *value, size_t size) | |
1959 | { | |
1960 | char *newsmack; | |
1961 | ||
1962 | if (!__capable(p, CAP_MAC_ADMIN)) | |
1963 | return -EPERM; | |
1964 | ||
1965 | /* | |
1966 | * Changing another process' Smack value is too dangerous | |
1967 | * and supports no sane use case. | |
1968 | */ | |
1969 | if (p != current) | |
1970 | return -EPERM; | |
1971 | ||
1972 | if (value == NULL || size == 0 || size >= SMK_LABELLEN) | |
1973 | return -EINVAL; | |
1974 | ||
1975 | if (strcmp(name, "current") != 0) | |
1976 | return -EINVAL; | |
1977 | ||
1978 | newsmack = smk_import(value, size); | |
1979 | if (newsmack == NULL) | |
1980 | return -EINVAL; | |
1981 | ||
1982 | p->security = newsmack; | |
1983 | return size; | |
1984 | } | |
1985 | ||
1986 | /** | |
1987 | * smack_unix_stream_connect - Smack access on UDS | |
1988 | * @sock: one socket | |
1989 | * @other: the other socket | |
1990 | * @newsk: unused | |
1991 | * | |
1992 | * Return 0 if a subject with the smack of sock could access | |
1993 | * an object with the smack of other, otherwise an error code | |
1994 | */ | |
1995 | static int smack_unix_stream_connect(struct socket *sock, | |
1996 | struct socket *other, struct sock *newsk) | |
1997 | { | |
1998 | struct inode *sp = SOCK_INODE(sock); | |
1999 | struct inode *op = SOCK_INODE(other); | |
2000 | ||
2001 | return smk_access(smk_of_inode(sp), smk_of_inode(op), MAY_READWRITE); | |
2002 | } | |
2003 | ||
2004 | /** | |
2005 | * smack_unix_may_send - Smack access on UDS | |
2006 | * @sock: one socket | |
2007 | * @other: the other socket | |
2008 | * | |
2009 | * Return 0 if a subject with the smack of sock could access | |
2010 | * an object with the smack of other, otherwise an error code | |
2011 | */ | |
2012 | static int smack_unix_may_send(struct socket *sock, struct socket *other) | |
2013 | { | |
2014 | struct inode *sp = SOCK_INODE(sock); | |
2015 | struct inode *op = SOCK_INODE(other); | |
2016 | ||
2017 | return smk_access(smk_of_inode(sp), smk_of_inode(op), MAY_WRITE); | |
2018 | } | |
2019 | ||
2020 | /** | |
2021 | * smack_from_secattr - Convert a netlabel attr.mls.lvl/attr.mls.cat | |
2022 | * pair to smack | |
2023 | * @sap: netlabel secattr | |
2024 | * @sip: where to put the result | |
2025 | * | |
2026 | * Copies a smack label into sip | |
2027 | */ | |
2028 | static void smack_from_secattr(struct netlbl_lsm_secattr *sap, char *sip) | |
2029 | { | |
2030 | char smack[SMK_LABELLEN]; | |
2031 | int pcat; | |
2032 | ||
2033 | if ((sap->flags & NETLBL_SECATTR_MLS_LVL) == 0) { | |
2034 | /* | |
2035 | * If there are flags but no level netlabel isn't | |
2036 | * behaving the way we expect it to. | |
2037 | * | |
2038 | * Without guidance regarding the smack value | |
2039 | * for the packet fall back on the network | |
2040 | * ambient value. | |
2041 | */ | |
2042 | strncpy(sip, smack_net_ambient, SMK_MAXLEN); | |
2043 | return; | |
2044 | } | |
2045 | /* | |
2046 | * Get the categories, if any | |
2047 | */ | |
2048 | memset(smack, '\0', SMK_LABELLEN); | |
2049 | if ((sap->flags & NETLBL_SECATTR_MLS_CAT) != 0) | |
2050 | for (pcat = -1;;) { | |
2051 | pcat = netlbl_secattr_catmap_walk(sap->attr.mls.cat, | |
2052 | pcat + 1); | |
2053 | if (pcat < 0) | |
2054 | break; | |
2055 | smack_catset_bit(pcat, smack); | |
2056 | } | |
2057 | /* | |
2058 | * If it is CIPSO using smack direct mapping | |
2059 | * we are already done. WeeHee. | |
2060 | */ | |
2061 | if (sap->attr.mls.lvl == smack_cipso_direct) { | |
2062 | memcpy(sip, smack, SMK_MAXLEN); | |
2063 | return; | |
2064 | } | |
2065 | /* | |
2066 | * Look it up in the supplied table if it is not a direct mapping. | |
2067 | */ | |
2068 | smack_from_cipso(sap->attr.mls.lvl, smack, sip); | |
2069 | return; | |
2070 | } | |
2071 | ||
2072 | /** | |
2073 | * smack_socket_sock_rcv_skb - Smack packet delivery access check | |
2074 | * @sk: socket | |
2075 | * @skb: packet | |
2076 | * | |
2077 | * Returns 0 if the packet should be delivered, an error code otherwise | |
2078 | */ | |
2079 | static int smack_socket_sock_rcv_skb(struct sock *sk, struct sk_buff *skb) | |
2080 | { | |
2081 | struct netlbl_lsm_secattr secattr; | |
2082 | struct socket_smack *ssp = sk->sk_security; | |
2083 | char smack[SMK_LABELLEN]; | |
2084 | int rc; | |
2085 | ||
2086 | if (sk->sk_family != PF_INET && sk->sk_family != PF_INET6) | |
2087 | return 0; | |
2088 | ||
2089 | /* | |
2090 | * Translate what netlabel gave us. | |
2091 | */ | |
2092 | memset(smack, '\0', SMK_LABELLEN); | |
2093 | netlbl_secattr_init(&secattr); | |
2094 | rc = netlbl_skbuff_getattr(skb, sk->sk_family, &secattr); | |
2095 | if (rc == 0) | |
2096 | smack_from_secattr(&secattr, smack); | |
2097 | else | |
2098 | strncpy(smack, smack_net_ambient, SMK_MAXLEN); | |
2099 | netlbl_secattr_destroy(&secattr); | |
2100 | /* | |
2101 | * Receiving a packet requires that the other end | |
2102 | * be able to write here. Read access is not required. | |
2103 | * This is the simplist possible security model | |
2104 | * for networking. | |
2105 | */ | |
2106 | return smk_access(smack, ssp->smk_in, MAY_WRITE); | |
2107 | } | |
2108 | ||
2109 | /** | |
2110 | * smack_socket_getpeersec_stream - pull in packet label | |
2111 | * @sock: the socket | |
2112 | * @optval: user's destination | |
2113 | * @optlen: size thereof | |
2114 | * @len: max thereoe | |
2115 | * | |
2116 | * returns zero on success, an error code otherwise | |
2117 | */ | |
2118 | static int smack_socket_getpeersec_stream(struct socket *sock, | |
2119 | char __user *optval, | |
2120 | int __user *optlen, unsigned len) | |
2121 | { | |
2122 | struct socket_smack *ssp; | |
2123 | int slen; | |
2124 | int rc = 0; | |
2125 | ||
2126 | ssp = sock->sk->sk_security; | |
2127 | slen = strlen(ssp->smk_packet) + 1; | |
2128 | ||
2129 | if (slen > len) | |
2130 | rc = -ERANGE; | |
2131 | else if (copy_to_user(optval, ssp->smk_packet, slen) != 0) | |
2132 | rc = -EFAULT; | |
2133 | ||
2134 | if (put_user(slen, optlen) != 0) | |
2135 | rc = -EFAULT; | |
2136 | ||
2137 | return rc; | |
2138 | } | |
2139 | ||
2140 | ||
2141 | /** | |
2142 | * smack_socket_getpeersec_dgram - pull in packet label | |
2143 | * @sock: the socket | |
2144 | * @skb: packet data | |
2145 | * @secid: pointer to where to put the secid of the packet | |
2146 | * | |
2147 | * Sets the netlabel socket state on sk from parent | |
2148 | */ | |
2149 | static int smack_socket_getpeersec_dgram(struct socket *sock, | |
2150 | struct sk_buff *skb, u32 *secid) | |
2151 | ||
2152 | { | |
2153 | struct netlbl_lsm_secattr secattr; | |
2154 | struct sock *sk; | |
2155 | char smack[SMK_LABELLEN]; | |
2156 | int family = PF_INET; | |
2157 | u32 s; | |
2158 | int rc; | |
2159 | ||
2160 | /* | |
2161 | * Only works for families with packets. | |
2162 | */ | |
2163 | if (sock != NULL) { | |
2164 | sk = sock->sk; | |
2165 | if (sk->sk_family != PF_INET && sk->sk_family != PF_INET6) | |
2166 | return 0; | |
2167 | family = sk->sk_family; | |
2168 | } | |
2169 | /* | |
2170 | * Translate what netlabel gave us. | |
2171 | */ | |
2172 | memset(smack, '\0', SMK_LABELLEN); | |
2173 | netlbl_secattr_init(&secattr); | |
2174 | rc = netlbl_skbuff_getattr(skb, family, &secattr); | |
2175 | if (rc == 0) | |
2176 | smack_from_secattr(&secattr, smack); | |
2177 | netlbl_secattr_destroy(&secattr); | |
2178 | ||
2179 | /* | |
2180 | * Give up if we couldn't get anything | |
2181 | */ | |
2182 | if (rc != 0) | |
2183 | return rc; | |
2184 | ||
2185 | s = smack_to_secid(smack); | |
2186 | if (s == 0) | |
2187 | return -EINVAL; | |
2188 | ||
2189 | *secid = s; | |
2190 | return 0; | |
2191 | } | |
2192 | ||
2193 | /** | |
2194 | * smack_sock_graft - graft access state between two sockets | |
2195 | * @sk: fresh sock | |
2196 | * @parent: donor socket | |
2197 | * | |
2198 | * Sets the netlabel socket state on sk from parent | |
2199 | */ | |
2200 | static void smack_sock_graft(struct sock *sk, struct socket *parent) | |
2201 | { | |
2202 | struct socket_smack *ssp; | |
2203 | int rc; | |
2204 | ||
2205 | if (sk == NULL) | |
2206 | return; | |
2207 | ||
2208 | if (sk->sk_family != PF_INET && sk->sk_family != PF_INET6) | |
2209 | return; | |
2210 | ||
2211 | ssp = sk->sk_security; | |
2212 | ssp->smk_in = current->security; | |
2213 | ssp->smk_out = current->security; | |
2214 | ssp->smk_packet[0] = '\0'; | |
2215 | ||
2216 | rc = smack_netlabel(sk); | |
2217 | } | |
2218 | ||
2219 | /** | |
2220 | * smack_inet_conn_request - Smack access check on connect | |
2221 | * @sk: socket involved | |
2222 | * @skb: packet | |
2223 | * @req: unused | |
2224 | * | |
2225 | * Returns 0 if a task with the packet label could write to | |
2226 | * the socket, otherwise an error code | |
2227 | */ | |
2228 | static int smack_inet_conn_request(struct sock *sk, struct sk_buff *skb, | |
2229 | struct request_sock *req) | |
2230 | { | |
2231 | struct netlbl_lsm_secattr skb_secattr; | |
2232 | struct socket_smack *ssp = sk->sk_security; | |
2233 | char smack[SMK_LABELLEN]; | |
2234 | int rc; | |
2235 | ||
2236 | if (skb == NULL) | |
2237 | return -EACCES; | |
2238 | ||
2239 | memset(smack, '\0', SMK_LABELLEN); | |
2240 | netlbl_secattr_init(&skb_secattr); | |
2241 | rc = netlbl_skbuff_getattr(skb, sk->sk_family, &skb_secattr); | |
2242 | if (rc == 0) | |
2243 | smack_from_secattr(&skb_secattr, smack); | |
2244 | else | |
2245 | strncpy(smack, smack_known_huh.smk_known, SMK_MAXLEN); | |
2246 | netlbl_secattr_destroy(&skb_secattr); | |
2247 | /* | |
2248 | * Receiving a packet requires that the other end | |
2249 | * be able to write here. Read access is not required. | |
2250 | * | |
2251 | * If the request is successful save the peer's label | |
2252 | * so that SO_PEERCRED can report it. | |
2253 | */ | |
2254 | rc = smk_access(smack, ssp->smk_in, MAY_WRITE); | |
2255 | if (rc == 0) | |
2256 | strncpy(ssp->smk_packet, smack, SMK_MAXLEN); | |
2257 | ||
2258 | return rc; | |
2259 | } | |
2260 | ||
2261 | /* | |
2262 | * Key management security hooks | |
2263 | * | |
2264 | * Casey has not tested key support very heavily. | |
2265 | * The permission check is most likely too restrictive. | |
2266 | * If you care about keys please have a look. | |
2267 | */ | |
2268 | #ifdef CONFIG_KEYS | |
2269 | ||
2270 | /** | |
2271 | * smack_key_alloc - Set the key security blob | |
2272 | * @key: object | |
2273 | * @tsk: the task associated with the key | |
2274 | * @flags: unused | |
2275 | * | |
2276 | * No allocation required | |
2277 | * | |
2278 | * Returns 0 | |
2279 | */ | |
2280 | static int smack_key_alloc(struct key *key, struct task_struct *tsk, | |
2281 | unsigned long flags) | |
2282 | { | |
2283 | key->security = tsk->security; | |
2284 | return 0; | |
2285 | } | |
2286 | ||
2287 | /** | |
2288 | * smack_key_free - Clear the key security blob | |
2289 | * @key: the object | |
2290 | * | |
2291 | * Clear the blob pointer | |
2292 | */ | |
2293 | static void smack_key_free(struct key *key) | |
2294 | { | |
2295 | key->security = NULL; | |
2296 | } | |
2297 | ||
2298 | /* | |
2299 | * smack_key_permission - Smack access on a key | |
2300 | * @key_ref: gets to the object | |
2301 | * @context: task involved | |
2302 | * @perm: unused | |
2303 | * | |
2304 | * Return 0 if the task has read and write to the object, | |
2305 | * an error code otherwise | |
2306 | */ | |
2307 | static int smack_key_permission(key_ref_t key_ref, | |
2308 | struct task_struct *context, key_perm_t perm) | |
2309 | { | |
2310 | struct key *keyp; | |
2311 | ||
2312 | keyp = key_ref_to_ptr(key_ref); | |
2313 | if (keyp == NULL) | |
2314 | return -EINVAL; | |
2315 | /* | |
2316 | * If the key hasn't been initialized give it access so that | |
2317 | * it may do so. | |
2318 | */ | |
2319 | if (keyp->security == NULL) | |
2320 | return 0; | |
2321 | /* | |
2322 | * This should not occur | |
2323 | */ | |
2324 | if (context->security == NULL) | |
2325 | return -EACCES; | |
2326 | ||
2327 | return smk_access(context->security, keyp->security, MAY_READWRITE); | |
2328 | } | |
2329 | #endif /* CONFIG_KEYS */ | |
2330 | ||
2331 | /* | |
2332 | * smack_secid_to_secctx - return the smack label for a secid | |
2333 | * @secid: incoming integer | |
2334 | * @secdata: destination | |
2335 | * @seclen: how long it is | |
2336 | * | |
2337 | * Exists for networking code. | |
2338 | */ | |
2339 | static int smack_secid_to_secctx(u32 secid, char **secdata, u32 *seclen) | |
2340 | { | |
2341 | char *sp = smack_from_secid(secid); | |
2342 | ||
2343 | *secdata = sp; | |
2344 | *seclen = strlen(sp); | |
2345 | return 0; | |
2346 | } | |
2347 | ||
2348 | /* | |
2349 | * smack_release_secctx - don't do anything. | |
2350 | * @key_ref: unused | |
2351 | * @context: unused | |
2352 | * @perm: unused | |
2353 | * | |
2354 | * Exists to make sure nothing gets done, and properly | |
2355 | */ | |
2356 | static void smack_release_secctx(char *secdata, u32 seclen) | |
2357 | { | |
2358 | } | |
2359 | ||
2360 | static struct security_operations smack_ops = { | |
2361 | .ptrace = smack_ptrace, | |
2362 | .capget = cap_capget, | |
2363 | .capset_check = cap_capset_check, | |
2364 | .capset_set = cap_capset_set, | |
2365 | .capable = cap_capable, | |
2366 | .syslog = smack_syslog, | |
2367 | .settime = cap_settime, | |
2368 | .vm_enough_memory = cap_vm_enough_memory, | |
2369 | ||
2370 | .bprm_apply_creds = cap_bprm_apply_creds, | |
2371 | .bprm_set_security = cap_bprm_set_security, | |
2372 | .bprm_secureexec = cap_bprm_secureexec, | |
2373 | ||
2374 | .sb_alloc_security = smack_sb_alloc_security, | |
2375 | .sb_free_security = smack_sb_free_security, | |
2376 | .sb_copy_data = smack_sb_copy_data, | |
2377 | .sb_kern_mount = smack_sb_kern_mount, | |
2378 | .sb_statfs = smack_sb_statfs, | |
2379 | .sb_mount = smack_sb_mount, | |
2380 | .sb_umount = smack_sb_umount, | |
2381 | ||
2382 | .inode_alloc_security = smack_inode_alloc_security, | |
2383 | .inode_free_security = smack_inode_free_security, | |
2384 | .inode_init_security = smack_inode_init_security, | |
2385 | .inode_link = smack_inode_link, | |
2386 | .inode_unlink = smack_inode_unlink, | |
2387 | .inode_rmdir = smack_inode_rmdir, | |
2388 | .inode_rename = smack_inode_rename, | |
2389 | .inode_permission = smack_inode_permission, | |
2390 | .inode_setattr = smack_inode_setattr, | |
2391 | .inode_getattr = smack_inode_getattr, | |
2392 | .inode_setxattr = smack_inode_setxattr, | |
2393 | .inode_post_setxattr = smack_inode_post_setxattr, | |
2394 | .inode_getxattr = smack_inode_getxattr, | |
2395 | .inode_removexattr = smack_inode_removexattr, | |
2396 | .inode_getsecurity = smack_inode_getsecurity, | |
2397 | .inode_setsecurity = smack_inode_setsecurity, | |
2398 | .inode_listsecurity = smack_inode_listsecurity, | |
2399 | ||
2400 | .file_permission = smack_file_permission, | |
2401 | .file_alloc_security = smack_file_alloc_security, | |
2402 | .file_free_security = smack_file_free_security, | |
2403 | .file_ioctl = smack_file_ioctl, | |
2404 | .file_lock = smack_file_lock, | |
2405 | .file_fcntl = smack_file_fcntl, | |
2406 | .file_set_fowner = smack_file_set_fowner, | |
2407 | .file_send_sigiotask = smack_file_send_sigiotask, | |
2408 | .file_receive = smack_file_receive, | |
2409 | ||
2410 | .task_alloc_security = smack_task_alloc_security, | |
2411 | .task_free_security = smack_task_free_security, | |
2412 | .task_post_setuid = cap_task_post_setuid, | |
2413 | .task_setpgid = smack_task_setpgid, | |
2414 | .task_getpgid = smack_task_getpgid, | |
2415 | .task_getsid = smack_task_getsid, | |
2416 | .task_getsecid = smack_task_getsecid, | |
2417 | .task_setnice = smack_task_setnice, | |
2418 | .task_setioprio = smack_task_setioprio, | |
2419 | .task_getioprio = smack_task_getioprio, | |
2420 | .task_setscheduler = smack_task_setscheduler, | |
2421 | .task_getscheduler = smack_task_getscheduler, | |
2422 | .task_movememory = smack_task_movememory, | |
2423 | .task_kill = smack_task_kill, | |
2424 | .task_wait = smack_task_wait, | |
2425 | .task_reparent_to_init = cap_task_reparent_to_init, | |
2426 | .task_to_inode = smack_task_to_inode, | |
2427 | ||
2428 | .ipc_permission = smack_ipc_permission, | |
2429 | ||
2430 | .msg_msg_alloc_security = smack_msg_msg_alloc_security, | |
2431 | .msg_msg_free_security = smack_msg_msg_free_security, | |
2432 | ||
2433 | .msg_queue_alloc_security = smack_msg_queue_alloc_security, | |
2434 | .msg_queue_free_security = smack_msg_queue_free_security, | |
2435 | .msg_queue_associate = smack_msg_queue_associate, | |
2436 | .msg_queue_msgctl = smack_msg_queue_msgctl, | |
2437 | .msg_queue_msgsnd = smack_msg_queue_msgsnd, | |
2438 | .msg_queue_msgrcv = smack_msg_queue_msgrcv, | |
2439 | ||
2440 | .shm_alloc_security = smack_shm_alloc_security, | |
2441 | .shm_free_security = smack_shm_free_security, | |
2442 | .shm_associate = smack_shm_associate, | |
2443 | .shm_shmctl = smack_shm_shmctl, | |
2444 | .shm_shmat = smack_shm_shmat, | |
2445 | ||
2446 | .sem_alloc_security = smack_sem_alloc_security, | |
2447 | .sem_free_security = smack_sem_free_security, | |
2448 | .sem_associate = smack_sem_associate, | |
2449 | .sem_semctl = smack_sem_semctl, | |
2450 | .sem_semop = smack_sem_semop, | |
2451 | ||
2452 | .netlink_send = cap_netlink_send, | |
2453 | .netlink_recv = cap_netlink_recv, | |
2454 | ||
2455 | .d_instantiate = smack_d_instantiate, | |
2456 | ||
2457 | .getprocattr = smack_getprocattr, | |
2458 | .setprocattr = smack_setprocattr, | |
2459 | ||
2460 | .unix_stream_connect = smack_unix_stream_connect, | |
2461 | .unix_may_send = smack_unix_may_send, | |
2462 | ||
2463 | .socket_post_create = smack_socket_post_create, | |
2464 | .socket_sock_rcv_skb = smack_socket_sock_rcv_skb, | |
2465 | .socket_getpeersec_stream = smack_socket_getpeersec_stream, | |
2466 | .socket_getpeersec_dgram = smack_socket_getpeersec_dgram, | |
2467 | .sk_alloc_security = smack_sk_alloc_security, | |
2468 | .sk_free_security = smack_sk_free_security, | |
2469 | .sock_graft = smack_sock_graft, | |
2470 | .inet_conn_request = smack_inet_conn_request, | |
2471 | /* key management security hooks */ | |
2472 | #ifdef CONFIG_KEYS | |
2473 | .key_alloc = smack_key_alloc, | |
2474 | .key_free = smack_key_free, | |
2475 | .key_permission = smack_key_permission, | |
2476 | #endif /* CONFIG_KEYS */ | |
2477 | .secid_to_secctx = smack_secid_to_secctx, | |
2478 | .release_secctx = smack_release_secctx, | |
2479 | }; | |
2480 | ||
2481 | /** | |
2482 | * smack_init - initialize the smack system | |
2483 | * | |
2484 | * Returns 0 | |
2485 | */ | |
2486 | static __init int smack_init(void) | |
2487 | { | |
2488 | printk(KERN_INFO "Smack: Initializing.\n"); | |
2489 | ||
2490 | /* | |
2491 | * Set the security state for the initial task. | |
2492 | */ | |
2493 | current->security = &smack_known_floor.smk_known; | |
2494 | ||
2495 | /* | |
2496 | * Initialize locks | |
2497 | */ | |
2498 | spin_lock_init(&smack_known_unset.smk_cipsolock); | |
2499 | spin_lock_init(&smack_known_huh.smk_cipsolock); | |
2500 | spin_lock_init(&smack_known_hat.smk_cipsolock); | |
2501 | spin_lock_init(&smack_known_star.smk_cipsolock); | |
2502 | spin_lock_init(&smack_known_floor.smk_cipsolock); | |
2503 | spin_lock_init(&smack_known_invalid.smk_cipsolock); | |
2504 | ||
2505 | /* | |
2506 | * Register with LSM | |
2507 | */ | |
2508 | if (register_security(&smack_ops)) | |
2509 | panic("smack: Unable to register with kernel.\n"); | |
2510 | ||
2511 | return 0; | |
2512 | } | |
2513 | ||
2514 | /* | |
2515 | * Smack requires early initialization in order to label | |
2516 | * all processes and objects when they are created. | |
2517 | */ | |
2518 | security_initcall(smack_init); | |
2519 |