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1da177e4 LT |
1 | /** |
2 | * BSD Secure Levels LSM | |
3 | * | |
4 | * Maintainers: | |
5 | * Michael A. Halcrow <mike@halcrow.us> | |
6 | * Serge Hallyn <hallyn@cs.wm.edu> | |
7 | * | |
8 | * Copyright (c) 2001 WireX Communications, Inc <chris@wirex.com> | |
9 | * Copyright (c) 2001 Greg Kroah-Hartman <greg@kroah.com> | |
10 | * Copyright (c) 2002 International Business Machines <robb@austin.ibm.com> | |
11 | * | |
12 | * This program is free software; you can redistribute it and/or modify | |
13 | * it under the terms of the GNU General Public License as published by | |
14 | * the Free Software Foundation; either version 2 of the License, or | |
15 | * (at your option) any later version. | |
16 | */ | |
17 | ||
18 | #include <linux/config.h> | |
19 | #include <linux/module.h> | |
20 | #include <linux/moduleparam.h> | |
21 | #include <linux/kernel.h> | |
22 | #include <linux/init.h> | |
23 | #include <linux/security.h> | |
24 | #include <linux/netlink.h> | |
25 | #include <linux/fs.h> | |
26 | #include <linux/namei.h> | |
27 | #include <linux/mount.h> | |
28 | #include <linux/capability.h> | |
29 | #include <linux/time.h> | |
30 | #include <linux/proc_fs.h> | |
31 | #include <linux/kobject.h> | |
32 | #include <linux/crypto.h> | |
33 | #include <asm/scatterlist.h> | |
34 | #include <linux/gfp.h> | |
35 | #include <linux/sysfs.h> | |
36 | ||
37 | #define SHA1_DIGEST_SIZE 20 | |
38 | ||
39 | /** | |
40 | * Module parameter that defines the initial secure level. | |
41 | * | |
42 | * When built as a module, it defaults to seclvl 1, which is the | |
43 | * behavior of BSD secure levels. Note that this default behavior | |
44 | * wrecks havoc on a machine when the seclvl module is compiled into | |
45 | * the kernel. In that case, we default to seclvl 0. | |
46 | */ | |
47 | #ifdef CONFIG_SECURITY_SECLVL_MODULE | |
48 | static int initlvl = 1; | |
49 | #else | |
50 | static int initlvl; | |
51 | #endif | |
52 | module_param(initlvl, int, 0); | |
53 | MODULE_PARM_DESC(initlvl, "Initial secure level (defaults to 1)"); | |
54 | ||
55 | /* Module parameter that defines the verbosity level */ | |
56 | static int verbosity; | |
57 | module_param(verbosity, int, 0); | |
58 | MODULE_PARM_DESC(verbosity, "Initial verbosity level (0 or 1; defaults to " | |
59 | "0, which is Quiet)"); | |
60 | ||
61 | /** | |
62 | * Optional password which can be passed in to bring seclvl to 0 | |
63 | * (i.e., for halt/reboot). Defaults to NULL (the passwd attribute | |
64 | * file will not be registered in sysfs). | |
65 | * | |
66 | * This gets converted to its SHA1 hash when stored. It's probably | |
67 | * not a good idea to use this parameter when loading seclvl from a | |
68 | * script; use sha1_passwd instead. | |
69 | */ | |
70 | ||
71 | #define MAX_PASSWD_SIZE 32 | |
72 | static char passwd[MAX_PASSWD_SIZE]; | |
73 | module_param_string(passwd, passwd, sizeof(passwd), 0); | |
74 | MODULE_PARM_DESC(passwd, | |
75 | "Plaintext of password that sets seclvl=0 when written to " | |
76 | "(sysfs mount point)/seclvl/passwd\n"); | |
77 | ||
78 | /** | |
79 | * SHA1 hashed version of the optional password which can be passed in | |
80 | * to bring seclvl to 0 (i.e., for halt/reboot). Must be in | |
81 | * hexadecimal format (40 characters). Defaults to NULL (the passwd | |
82 | * attribute file will not be registered in sysfs). | |
83 | * | |
84 | * Use the sha1sum utility to generate the SHA1 hash of a password: | |
85 | * | |
86 | * echo -n "secret" | sha1sum | |
87 | */ | |
88 | #define MAX_SHA1_PASSWD 41 | |
89 | static char sha1_passwd[MAX_SHA1_PASSWD]; | |
90 | module_param_string(sha1_passwd, sha1_passwd, sizeof(sha1_passwd), 0); | |
91 | MODULE_PARM_DESC(sha1_passwd, | |
92 | "SHA1 hash (40 hexadecimal characters) of password that " | |
93 | "sets seclvl=0 when plaintext password is written to " | |
94 | "(sysfs mount point)/seclvl/passwd\n"); | |
95 | ||
96 | static int hideHash = 1; | |
97 | module_param(hideHash, int, 0); | |
98 | MODULE_PARM_DESC(hideHash, "When set to 0, reading seclvl/passwd from sysfs " | |
99 | "will return the SHA1-hashed value of the password that " | |
100 | "lowers the secure level to 0.\n"); | |
101 | ||
102 | #define MY_NAME "seclvl" | |
103 | ||
104 | /** | |
105 | * This time-limits log writes to one per second. | |
106 | */ | |
107 | #define seclvl_printk(verb, type, fmt, arg...) \ | |
108 | do { \ | |
109 | if (verbosity >= verb) { \ | |
110 | static unsigned long _prior; \ | |
111 | unsigned long _now = jiffies; \ | |
112 | if ((_now - _prior) > HZ) { \ | |
113 | printk(type "%s: %s: " fmt, \ | |
114 | MY_NAME, __FUNCTION__ , \ | |
115 | ## arg); \ | |
116 | _prior = _now; \ | |
117 | } \ | |
118 | } \ | |
119 | } while (0) | |
120 | ||
1da177e4 LT |
121 | /** |
122 | * The actual security level. Ranges between -1 and 2 inclusive. | |
123 | */ | |
124 | static int seclvl; | |
125 | ||
126 | /** | |
127 | * flag to keep track of how we were registered | |
128 | */ | |
129 | static int secondary; | |
130 | ||
131 | /** | |
132 | * Verifies that the requested secure level is valid, given the current | |
133 | * secure level. | |
134 | */ | |
135 | static int seclvl_sanity(int reqlvl) | |
136 | { | |
137 | if ((reqlvl < -1) || (reqlvl > 2)) { | |
138 | seclvl_printk(1, KERN_WARNING, "Attempt to set seclvl out of " | |
139 | "range: [%d]\n", reqlvl); | |
140 | return -EINVAL; | |
141 | } | |
142 | if ((seclvl == 0) && (reqlvl == -1)) | |
143 | return 0; | |
144 | if (reqlvl < seclvl) { | |
145 | seclvl_printk(1, KERN_WARNING, "Attempt to lower seclvl to " | |
146 | "[%d]\n", reqlvl); | |
147 | return -EPERM; | |
148 | } | |
149 | return 0; | |
150 | } | |
151 | ||
1da177e4 LT |
152 | /** |
153 | * security level advancement rules: | |
154 | * Valid levels are -1 through 2, inclusive. | |
155 | * From -1, stuck. [ in case compiled into kernel ] | |
156 | * From 0 or above, can only increment. | |
157 | */ | |
5a73c308 | 158 | static void do_seclvl_advance(void *data, u64 val) |
1da177e4 | 159 | { |
5a73c308 | 160 | int ret; |
161 | int newlvl = (int)val; | |
162 | ||
163 | ret = seclvl_sanity(newlvl); | |
164 | if (ret) | |
165 | return; | |
166 | ||
1da177e4 LT |
167 | if (newlvl > 2) { |
168 | seclvl_printk(1, KERN_WARNING, "Cannot advance to seclvl " | |
169 | "[%d]\n", newlvl); | |
5a73c308 | 170 | return; |
1da177e4 LT |
171 | } |
172 | if (seclvl == -1) { | |
173 | seclvl_printk(1, KERN_WARNING, "Not allowed to advance to " | |
174 | "seclvl [%d]\n", seclvl); | |
5a73c308 | 175 | return; |
1da177e4 | 176 | } |
5a73c308 | 177 | seclvl = newlvl; /* would it be more "correct" to set *data? */ |
178 | return; | |
1da177e4 LT |
179 | } |
180 | ||
5a73c308 | 181 | static u64 seclvl_int_get(void *data) |
1da177e4 | 182 | { |
5a73c308 | 183 | return *(int *)data; |
1da177e4 LT |
184 | } |
185 | ||
5a73c308 | 186 | DEFINE_SIMPLE_ATTRIBUTE(seclvl_file_ops, seclvl_int_get, do_seclvl_advance, "%lld\n"); |
1da177e4 LT |
187 | |
188 | static unsigned char hashedPassword[SHA1_DIGEST_SIZE]; | |
189 | ||
1da177e4 LT |
190 | /** |
191 | * Converts a block of plaintext of into its SHA1 hashed value. | |
192 | * | |
193 | * It would be nice if crypto had a wrapper to do this for us linear | |
194 | * people... | |
195 | */ | |
196 | static int | |
197 | plaintext_to_sha1(unsigned char *hash, const char *plaintext, int len) | |
198 | { | |
199 | char *pgVirtAddr; | |
200 | struct crypto_tfm *tfm; | |
201 | struct scatterlist sg[1]; | |
202 | if (len > PAGE_SIZE) { | |
203 | seclvl_printk(0, KERN_ERR, "Plaintext password too large (%d " | |
204 | "characters). Largest possible is %lu " | |
205 | "bytes.\n", len, PAGE_SIZE); | |
206 | return -ENOMEM; | |
207 | } | |
eb6f1160 | 208 | tfm = crypto_alloc_tfm("sha1", CRYPTO_TFM_REQ_MAY_SLEEP); |
1da177e4 LT |
209 | if (tfm == NULL) { |
210 | seclvl_printk(0, KERN_ERR, | |
211 | "Failed to load transform for SHA1\n"); | |
212 | return -ENOSYS; | |
213 | } | |
214 | // Just get a new page; don't play around with page boundaries | |
215 | // and scatterlists. | |
216 | pgVirtAddr = (char *)__get_free_page(GFP_KERNEL); | |
217 | sg[0].page = virt_to_page(pgVirtAddr); | |
218 | sg[0].offset = 0; | |
219 | sg[0].length = len; | |
220 | strncpy(pgVirtAddr, plaintext, len); | |
221 | crypto_digest_init(tfm); | |
222 | crypto_digest_update(tfm, sg, 1); | |
223 | crypto_digest_final(tfm, hash); | |
224 | crypto_free_tfm(tfm); | |
225 | free_page((unsigned long)pgVirtAddr); | |
226 | return 0; | |
227 | } | |
228 | ||
229 | /** | |
230 | * Called whenever the user writes to the sysfs passwd handle to this kernel | |
231 | * object. It hashes the password and compares the hashed results. | |
232 | */ | |
233 | static ssize_t | |
5a73c308 | 234 | passwd_write_file(struct file * file, const char __user * buf, |
235 | size_t count, loff_t *ppos) | |
1da177e4 LT |
236 | { |
237 | int i; | |
238 | unsigned char tmp[SHA1_DIGEST_SIZE]; | |
5a73c308 | 239 | char *page; |
1da177e4 LT |
240 | int rc; |
241 | int len; | |
5a73c308 | 242 | |
1da177e4 LT |
243 | if (!*passwd && !*sha1_passwd) { |
244 | seclvl_printk(0, KERN_ERR, "Attempt to password-unlock the " | |
245 | "seclvl module, but neither a plain text " | |
246 | "password nor a SHA1 hashed password was " | |
247 | "passed in as a module parameter! This is a " | |
248 | "bug, since it should not be possible to be in " | |
249 | "this part of the module; please tell a " | |
250 | "maintainer about this event.\n"); | |
251 | return -EINVAL; | |
252 | } | |
5a73c308 | 253 | |
254 | if (count < 0 || count >= PAGE_SIZE) | |
255 | return -ENOMEM; | |
256 | if (*ppos != 0) { | |
257 | return -EINVAL; | |
258 | } | |
259 | page = (char *)get_zeroed_page(GFP_KERNEL); | |
260 | if (!page) | |
261 | return -ENOMEM; | |
262 | len = -EFAULT; | |
263 | if (copy_from_user(page, buf, count)) | |
264 | goto out; | |
265 | ||
266 | len = strlen(page); | |
1da177e4 | 267 | /* ``echo "secret" > seclvl/passwd'' includes a newline */ |
5a73c308 | 268 | if (page[len - 1] == '\n') { |
1da177e4 LT |
269 | len--; |
270 | } | |
271 | /* Hash the password, then compare the hashed values */ | |
5a73c308 | 272 | if ((rc = plaintext_to_sha1(tmp, page, len))) { |
1da177e4 LT |
273 | seclvl_printk(0, KERN_ERR, "Error hashing password: rc = " |
274 | "[%d]\n", rc); | |
275 | return rc; | |
276 | } | |
277 | for (i = 0; i < SHA1_DIGEST_SIZE; i++) { | |
278 | if (hashedPassword[i] != tmp[i]) { | |
279 | return -EPERM; | |
280 | } | |
281 | } | |
282 | seclvl_printk(0, KERN_INFO, | |
283 | "Password accepted; seclvl reduced to 0.\n"); | |
284 | seclvl = 0; | |
5a73c308 | 285 | len = count; |
286 | ||
287 | out: | |
288 | free_page((unsigned long)page); | |
289 | return len; | |
1da177e4 LT |
290 | } |
291 | ||
5a73c308 | 292 | static struct file_operations passwd_file_ops = { |
293 | .write = passwd_write_file, | |
294 | }; | |
1da177e4 LT |
295 | |
296 | /** | |
297 | * Explicitely disallow ptrace'ing the init process. | |
298 | */ | |
299 | static int seclvl_ptrace(struct task_struct *parent, struct task_struct *child) | |
300 | { | |
301 | if (seclvl >= 0) { | |
302 | if (child->pid == 1) { | |
303 | seclvl_printk(1, KERN_WARNING, "Attempt to ptrace " | |
304 | "the init process dissallowed in " | |
305 | "secure level %d\n", seclvl); | |
306 | return -EPERM; | |
307 | } | |
308 | } | |
309 | return 0; | |
310 | } | |
311 | ||
312 | /** | |
313 | * Capability checks for seclvl. The majority of the policy | |
314 | * enforcement for seclvl takes place here. | |
315 | */ | |
316 | static int seclvl_capable(struct task_struct *tsk, int cap) | |
317 | { | |
318 | /* init can do anything it wants */ | |
319 | if (tsk->pid == 1) | |
320 | return 0; | |
321 | ||
322 | switch (seclvl) { | |
323 | case 2: | |
324 | /* fall through */ | |
325 | case 1: | |
326 | if (cap == CAP_LINUX_IMMUTABLE) { | |
327 | seclvl_printk(1, KERN_WARNING, "Attempt to modify " | |
328 | "the IMMUTABLE and/or APPEND extended " | |
329 | "attribute on a file with the IMMUTABLE " | |
330 | "and/or APPEND extended attribute set " | |
331 | "denied in seclvl [%d]\n", seclvl); | |
332 | return -EPERM; | |
333 | } else if (cap == CAP_SYS_RAWIO) { // Somewhat broad... | |
334 | seclvl_printk(1, KERN_WARNING, "Attempt to perform " | |
335 | "raw I/O while in secure level [%d] " | |
336 | "denied\n", seclvl); | |
337 | return -EPERM; | |
338 | } else if (cap == CAP_NET_ADMIN) { | |
339 | seclvl_printk(1, KERN_WARNING, "Attempt to perform " | |
340 | "network administrative task while " | |
341 | "in secure level [%d] denied\n", seclvl); | |
342 | return -EPERM; | |
343 | } else if (cap == CAP_SETUID) { | |
344 | seclvl_printk(1, KERN_WARNING, "Attempt to setuid " | |
345 | "while in secure level [%d] denied\n", | |
346 | seclvl); | |
347 | return -EPERM; | |
348 | } else if (cap == CAP_SETGID) { | |
349 | seclvl_printk(1, KERN_WARNING, "Attempt to setgid " | |
350 | "while in secure level [%d] denied\n", | |
351 | seclvl); | |
352 | } else if (cap == CAP_SYS_MODULE) { | |
353 | seclvl_printk(1, KERN_WARNING, "Attempt to perform " | |
354 | "a module operation while in secure " | |
355 | "level [%d] denied\n", seclvl); | |
356 | return -EPERM; | |
357 | } | |
358 | break; | |
359 | default: | |
360 | break; | |
361 | } | |
362 | /* from dummy.c */ | |
363 | if (cap_is_fs_cap(cap) ? tsk->fsuid == 0 : tsk->euid == 0) | |
364 | return 0; /* capability granted */ | |
365 | seclvl_printk(1, KERN_WARNING, "Capability denied\n"); | |
366 | return -EPERM; /* capability denied */ | |
367 | } | |
368 | ||
369 | /** | |
370 | * Disallow reversing the clock in seclvl > 1 | |
371 | */ | |
372 | static int seclvl_settime(struct timespec *tv, struct timezone *tz) | |
373 | { | |
374 | struct timespec now; | |
375 | if (seclvl > 1) { | |
376 | now = current_kernel_time(); | |
377 | if (tv->tv_sec < now.tv_sec || | |
378 | (tv->tv_sec == now.tv_sec && tv->tv_nsec < now.tv_nsec)) { | |
379 | seclvl_printk(1, KERN_WARNING, "Attempt to decrement " | |
380 | "time in secure level %d denied: " | |
381 | "current->pid = [%d], " | |
382 | "current->group_leader->pid = [%d]\n", | |
383 | seclvl, current->pid, | |
384 | current->group_leader->pid); | |
385 | return -EPERM; | |
386 | } /* if attempt to decrement time */ | |
387 | } /* if seclvl > 1 */ | |
388 | return 0; | |
389 | } | |
390 | ||
391 | /* claim the blockdev to exclude mounters, release on file close */ | |
392 | static int seclvl_bd_claim(struct inode *inode) | |
393 | { | |
394 | int holder; | |
395 | struct block_device *bdev = NULL; | |
396 | dev_t dev = inode->i_rdev; | |
397 | bdev = open_by_devnum(dev, FMODE_WRITE); | |
398 | if (bdev) { | |
399 | if (bd_claim(bdev, &holder)) { | |
400 | blkdev_put(bdev); | |
401 | return -EPERM; | |
402 | } | |
403 | /* claimed, mark it to release on close */ | |
404 | inode->i_security = current; | |
405 | } | |
406 | return 0; | |
407 | } | |
408 | ||
409 | /* release the blockdev if you claimed it */ | |
410 | static void seclvl_bd_release(struct inode *inode) | |
411 | { | |
412 | if (inode && S_ISBLK(inode->i_mode) && inode->i_security == current) { | |
413 | struct block_device *bdev = inode->i_bdev; | |
414 | if (bdev) { | |
415 | bd_release(bdev); | |
416 | blkdev_put(bdev); | |
417 | inode->i_security = NULL; | |
418 | } | |
419 | } | |
420 | } | |
421 | ||
422 | /** | |
423 | * Security for writes to block devices is regulated by this seclvl | |
424 | * function. Deny all writes to block devices in seclvl 2. In | |
425 | * seclvl 1, we only deny writes to *mounted* block devices. | |
426 | */ | |
427 | static int | |
428 | seclvl_inode_permission(struct inode *inode, int mask, struct nameidata *nd) | |
429 | { | |
430 | if (current->pid != 1 && S_ISBLK(inode->i_mode) && (mask & MAY_WRITE)) { | |
431 | switch (seclvl) { | |
432 | case 2: | |
433 | seclvl_printk(1, KERN_WARNING, "Write to block device " | |
434 | "denied in secure level [%d]\n", seclvl); | |
435 | return -EPERM; | |
436 | case 1: | |
437 | if (seclvl_bd_claim(inode)) { | |
438 | seclvl_printk(1, KERN_WARNING, | |
439 | "Write to mounted block device " | |
440 | "denied in secure level [%d]\n", | |
441 | seclvl); | |
442 | return -EPERM; | |
443 | } | |
444 | } | |
445 | } | |
446 | return 0; | |
447 | } | |
448 | ||
449 | /** | |
450 | * The SUID and SGID bits cannot be set in seclvl >= 1 | |
451 | */ | |
452 | static int seclvl_inode_setattr(struct dentry *dentry, struct iattr *iattr) | |
453 | { | |
454 | if (seclvl > 0) { | |
455 | if (iattr->ia_valid & ATTR_MODE) | |
456 | if (iattr->ia_mode & S_ISUID || | |
457 | iattr->ia_mode & S_ISGID) { | |
458 | seclvl_printk(1, KERN_WARNING, "Attempt to " | |
459 | "modify SUID or SGID bit " | |
460 | "denied in seclvl [%d]\n", | |
461 | seclvl); | |
462 | return -EPERM; | |
463 | } | |
464 | } | |
465 | return 0; | |
466 | } | |
467 | ||
468 | /* release busied block devices */ | |
469 | static void seclvl_file_free_security(struct file *filp) | |
470 | { | |
471 | struct dentry *dentry = filp->f_dentry; | |
472 | struct inode *inode = NULL; | |
473 | ||
474 | if (dentry) { | |
475 | inode = dentry->d_inode; | |
476 | seclvl_bd_release(inode); | |
477 | } | |
478 | } | |
479 | ||
480 | /** | |
481 | * Cannot unmount in secure level 2 | |
482 | */ | |
483 | static int seclvl_umount(struct vfsmount *mnt, int flags) | |
484 | { | |
485 | if (current->pid == 1) { | |
486 | return 0; | |
487 | } | |
488 | if (seclvl == 2) { | |
489 | seclvl_printk(1, KERN_WARNING, "Attempt to unmount in secure " | |
490 | "level %d\n", seclvl); | |
491 | return -EPERM; | |
492 | } | |
493 | return 0; | |
494 | } | |
495 | ||
496 | static struct security_operations seclvl_ops = { | |
497 | .ptrace = seclvl_ptrace, | |
498 | .capable = seclvl_capable, | |
499 | .inode_permission = seclvl_inode_permission, | |
500 | .inode_setattr = seclvl_inode_setattr, | |
501 | .file_free_security = seclvl_file_free_security, | |
502 | .settime = seclvl_settime, | |
503 | .sb_umount = seclvl_umount, | |
504 | }; | |
505 | ||
506 | /** | |
507 | * Process the password-related module parameters | |
508 | */ | |
509 | static int processPassword(void) | |
510 | { | |
511 | int rc = 0; | |
512 | hashedPassword[0] = '\0'; | |
513 | if (*passwd) { | |
514 | if (*sha1_passwd) { | |
515 | seclvl_printk(0, KERN_ERR, "Error: Both " | |
516 | "passwd and sha1_passwd " | |
517 | "were set, but they are mutually " | |
518 | "exclusive.\n"); | |
519 | return -EINVAL; | |
520 | } | |
521 | if ((rc = plaintext_to_sha1(hashedPassword, passwd, | |
522 | strlen(passwd)))) { | |
523 | seclvl_printk(0, KERN_ERR, "Error: SHA1 support not " | |
524 | "in kernel\n"); | |
525 | return rc; | |
526 | } | |
527 | /* All static data goes to the BSS, which zero's the | |
528 | * plaintext password out for us. */ | |
529 | } else if (*sha1_passwd) { // Base 16 | |
530 | int i; | |
531 | i = strlen(sha1_passwd); | |
532 | if (i != (SHA1_DIGEST_SIZE * 2)) { | |
533 | seclvl_printk(0, KERN_ERR, "Received [%d] bytes; " | |
534 | "expected [%d] for the hexadecimal " | |
535 | "representation of the SHA1 hash of " | |
536 | "the password.\n", | |
537 | i, (SHA1_DIGEST_SIZE * 2)); | |
538 | return -EINVAL; | |
539 | } | |
540 | while ((i -= 2) + 2) { | |
541 | unsigned char tmp; | |
542 | tmp = sha1_passwd[i + 2]; | |
543 | sha1_passwd[i + 2] = '\0'; | |
544 | hashedPassword[i / 2] = (unsigned char) | |
545 | simple_strtol(&sha1_passwd[i], NULL, 16); | |
546 | sha1_passwd[i + 2] = tmp; | |
547 | } | |
548 | } | |
549 | return 0; | |
550 | } | |
551 | ||
552 | /** | |
5a73c308 | 553 | * securityfs registrations |
1da177e4 | 554 | */ |
5a73c308 | 555 | struct dentry *dir_ino, *seclvl_ino, *passwd_ino; |
556 | ||
557 | static int seclvlfs_register(void) | |
1da177e4 | 558 | { |
5a73c308 | 559 | dir_ino = securityfs_create_dir("seclvl", NULL); |
560 | if (!dir_ino) | |
561 | return -EFAULT; | |
562 | ||
563 | seclvl_ino = securityfs_create_file("seclvl", S_IRUGO | S_IWUSR, | |
564 | dir_ino, &seclvl, &seclvl_file_ops); | |
565 | if (!seclvl_ino) | |
566 | goto out_deldir; | |
1da177e4 | 567 | if (*passwd || *sha1_passwd) { |
5a73c308 | 568 | passwd_ino = securityfs_create_file("passwd", S_IRUGO | S_IWUSR, |
569 | dir_ino, NULL, &passwd_file_ops); | |
570 | if (!passwd_ino) | |
571 | goto out_delf; | |
1da177e4 LT |
572 | } |
573 | return 0; | |
5a73c308 | 574 | |
575 | out_deldir: | |
576 | securityfs_remove(dir_ino); | |
577 | out_delf: | |
578 | securityfs_remove(seclvl_ino); | |
579 | ||
580 | return -EFAULT; | |
1da177e4 LT |
581 | } |
582 | ||
583 | /** | |
584 | * Initialize the seclvl module. | |
585 | */ | |
586 | static int __init seclvl_init(void) | |
587 | { | |
588 | int rc = 0; | |
589 | if (verbosity < 0 || verbosity > 1) { | |
590 | printk(KERN_ERR "Error: bad verbosity [%d]; only 0 or 1 " | |
591 | "are valid values\n", verbosity); | |
592 | rc = -EINVAL; | |
593 | goto exit; | |
594 | } | |
1da177e4 LT |
595 | if (initlvl < -1 || initlvl > 2) { |
596 | seclvl_printk(0, KERN_ERR, "Error: bad initial securelevel " | |
597 | "[%d].\n", initlvl); | |
598 | rc = -EINVAL; | |
599 | goto exit; | |
600 | } | |
601 | seclvl = initlvl; | |
602 | if ((rc = processPassword())) { | |
603 | seclvl_printk(0, KERN_ERR, "Error processing the password " | |
604 | "module parameter(s): rc = [%d]\n", rc); | |
605 | goto exit; | |
606 | } | |
607 | /* register ourselves with the security framework */ | |
608 | if (register_security(&seclvl_ops)) { | |
609 | seclvl_printk(0, KERN_ERR, | |
610 | "seclvl: Failure registering with the " | |
611 | "kernel.\n"); | |
612 | /* try registering with primary module */ | |
613 | rc = mod_reg_security(MY_NAME, &seclvl_ops); | |
614 | if (rc) { | |
615 | seclvl_printk(0, KERN_ERR, "seclvl: Failure " | |
616 | "registering with primary security " | |
617 | "module.\n"); | |
618 | goto exit; | |
619 | } /* if primary module registered */ | |
620 | secondary = 1; | |
621 | } /* if we registered ourselves with the security framework */ | |
5a73c308 | 622 | if ((rc = seclvlfs_register())) { |
1da177e4 LT |
623 | seclvl_printk(0, KERN_ERR, "Error registering with sysfs\n"); |
624 | goto exit; | |
625 | } | |
626 | seclvl_printk(0, KERN_INFO, "seclvl: Successfully initialized.\n"); | |
627 | exit: | |
628 | if (rc) { | |
629 | printk(KERN_ERR "seclvl: Error during initialization: rc = " | |
630 | "[%d]\n", rc); | |
631 | } | |
632 | return rc; | |
633 | } | |
634 | ||
635 | /** | |
636 | * Remove the seclvl module. | |
637 | */ | |
638 | static void __exit seclvl_exit(void) | |
639 | { | |
5a73c308 | 640 | securityfs_remove(seclvl_ino); |
1da177e4 | 641 | if (*passwd || *sha1_passwd) { |
5a73c308 | 642 | securityfs_remove(passwd_ino); |
1da177e4 | 643 | } |
5a73c308 | 644 | securityfs_remove(dir_ino); |
1da177e4 LT |
645 | if (secondary == 1) { |
646 | mod_unreg_security(MY_NAME, &seclvl_ops); | |
647 | } else if (unregister_security(&seclvl_ops)) { | |
648 | seclvl_printk(0, KERN_INFO, | |
649 | "seclvl: Failure unregistering with the " | |
650 | "kernel\n"); | |
651 | } | |
652 | } | |
653 | ||
654 | module_init(seclvl_init); | |
655 | module_exit(seclvl_exit); | |
656 | ||
657 | MODULE_AUTHOR("Michael A. Halcrow <mike@halcrow.us>"); | |
658 | MODULE_DESCRIPTION("LSM implementation of the BSD Secure Levels"); | |
659 | MODULE_LICENSE("GPL"); |