Commit | Line | Data |
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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> | |
6bb08da4 | 11 | * Copyright (c) 2006 Davi E. M. Arnaut <davi.arnaut@gmail.com> |
1da177e4 LT |
12 | * |
13 | * This program is free software; you can redistribute it and/or modify | |
14 | * it under the terms of the GNU General Public License as published by | |
15 | * the Free Software Foundation; either version 2 of the License, or | |
16 | * (at your option) any later version. | |
17 | */ | |
18 | ||
19 | #include <linux/config.h> | |
20 | #include <linux/module.h> | |
21 | #include <linux/moduleparam.h> | |
22 | #include <linux/kernel.h> | |
23 | #include <linux/init.h> | |
24 | #include <linux/security.h> | |
25 | #include <linux/netlink.h> | |
26 | #include <linux/fs.h> | |
27 | #include <linux/namei.h> | |
28 | #include <linux/mount.h> | |
29 | #include <linux/capability.h> | |
30 | #include <linux/time.h> | |
31 | #include <linux/proc_fs.h> | |
32 | #include <linux/kobject.h> | |
33 | #include <linux/crypto.h> | |
34 | #include <asm/scatterlist.h> | |
6bb08da4 | 35 | #include <linux/scatterlist.h> |
1da177e4 LT |
36 | #include <linux/gfp.h> |
37 | #include <linux/sysfs.h> | |
38 | ||
39 | #define SHA1_DIGEST_SIZE 20 | |
40 | ||
41 | /** | |
42 | * Module parameter that defines the initial secure level. | |
43 | * | |
44 | * When built as a module, it defaults to seclvl 1, which is the | |
45 | * behavior of BSD secure levels. Note that this default behavior | |
46 | * wrecks havoc on a machine when the seclvl module is compiled into | |
47 | * the kernel. In that case, we default to seclvl 0. | |
48 | */ | |
49 | #ifdef CONFIG_SECURITY_SECLVL_MODULE | |
50 | static int initlvl = 1; | |
51 | #else | |
52 | static int initlvl; | |
53 | #endif | |
54 | module_param(initlvl, int, 0); | |
55 | MODULE_PARM_DESC(initlvl, "Initial secure level (defaults to 1)"); | |
56 | ||
57 | /* Module parameter that defines the verbosity level */ | |
58 | static int verbosity; | |
59 | module_param(verbosity, int, 0); | |
60 | MODULE_PARM_DESC(verbosity, "Initial verbosity level (0 or 1; defaults to " | |
61 | "0, which is Quiet)"); | |
62 | ||
63 | /** | |
64 | * Optional password which can be passed in to bring seclvl to 0 | |
65 | * (i.e., for halt/reboot). Defaults to NULL (the passwd attribute | |
66 | * file will not be registered in sysfs). | |
67 | * | |
68 | * This gets converted to its SHA1 hash when stored. It's probably | |
69 | * not a good idea to use this parameter when loading seclvl from a | |
70 | * script; use sha1_passwd instead. | |
71 | */ | |
72 | ||
73 | #define MAX_PASSWD_SIZE 32 | |
74 | static char passwd[MAX_PASSWD_SIZE]; | |
75 | module_param_string(passwd, passwd, sizeof(passwd), 0); | |
76 | MODULE_PARM_DESC(passwd, | |
77 | "Plaintext of password that sets seclvl=0 when written to " | |
78 | "(sysfs mount point)/seclvl/passwd\n"); | |
79 | ||
80 | /** | |
81 | * SHA1 hashed version of the optional password which can be passed in | |
82 | * to bring seclvl to 0 (i.e., for halt/reboot). Must be in | |
83 | * hexadecimal format (40 characters). Defaults to NULL (the passwd | |
84 | * attribute file will not be registered in sysfs). | |
85 | * | |
86 | * Use the sha1sum utility to generate the SHA1 hash of a password: | |
87 | * | |
88 | * echo -n "secret" | sha1sum | |
89 | */ | |
90 | #define MAX_SHA1_PASSWD 41 | |
91 | static char sha1_passwd[MAX_SHA1_PASSWD]; | |
92 | module_param_string(sha1_passwd, sha1_passwd, sizeof(sha1_passwd), 0); | |
93 | MODULE_PARM_DESC(sha1_passwd, | |
94 | "SHA1 hash (40 hexadecimal characters) of password that " | |
95 | "sets seclvl=0 when plaintext password is written to " | |
96 | "(sysfs mount point)/seclvl/passwd\n"); | |
97 | ||
98 | static int hideHash = 1; | |
99 | module_param(hideHash, int, 0); | |
100 | MODULE_PARM_DESC(hideHash, "When set to 0, reading seclvl/passwd from sysfs " | |
101 | "will return the SHA1-hashed value of the password that " | |
102 | "lowers the secure level to 0.\n"); | |
103 | ||
104 | #define MY_NAME "seclvl" | |
105 | ||
106 | /** | |
107 | * This time-limits log writes to one per second. | |
108 | */ | |
109 | #define seclvl_printk(verb, type, fmt, arg...) \ | |
110 | do { \ | |
111 | if (verbosity >= verb) { \ | |
112 | static unsigned long _prior; \ | |
113 | unsigned long _now = jiffies; \ | |
114 | if ((_now - _prior) > HZ) { \ | |
115 | printk(type "%s: %s: " fmt, \ | |
116 | MY_NAME, __FUNCTION__ , \ | |
117 | ## arg); \ | |
118 | _prior = _now; \ | |
119 | } \ | |
120 | } \ | |
121 | } while (0) | |
122 | ||
1da177e4 LT |
123 | /** |
124 | * The actual security level. Ranges between -1 and 2 inclusive. | |
125 | */ | |
126 | static int seclvl; | |
127 | ||
128 | /** | |
129 | * flag to keep track of how we were registered | |
130 | */ | |
131 | static int secondary; | |
132 | ||
133 | /** | |
134 | * Verifies that the requested secure level is valid, given the current | |
135 | * secure level. | |
136 | */ | |
137 | static int seclvl_sanity(int reqlvl) | |
138 | { | |
139 | if ((reqlvl < -1) || (reqlvl > 2)) { | |
140 | seclvl_printk(1, KERN_WARNING, "Attempt to set seclvl out of " | |
141 | "range: [%d]\n", reqlvl); | |
142 | return -EINVAL; | |
143 | } | |
144 | if ((seclvl == 0) && (reqlvl == -1)) | |
145 | return 0; | |
146 | if (reqlvl < seclvl) { | |
147 | seclvl_printk(1, KERN_WARNING, "Attempt to lower seclvl to " | |
148 | "[%d]\n", reqlvl); | |
149 | return -EPERM; | |
150 | } | |
151 | return 0; | |
152 | } | |
153 | ||
1da177e4 LT |
154 | /** |
155 | * security level advancement rules: | |
156 | * Valid levels are -1 through 2, inclusive. | |
157 | * From -1, stuck. [ in case compiled into kernel ] | |
158 | * From 0 or above, can only increment. | |
159 | */ | |
5a73c308 | 160 | static void do_seclvl_advance(void *data, u64 val) |
1da177e4 | 161 | { |
5a73c308 | 162 | int ret; |
163 | int newlvl = (int)val; | |
164 | ||
165 | ret = seclvl_sanity(newlvl); | |
166 | if (ret) | |
167 | return; | |
168 | ||
1da177e4 LT |
169 | if (newlvl > 2) { |
170 | seclvl_printk(1, KERN_WARNING, "Cannot advance to seclvl " | |
171 | "[%d]\n", newlvl); | |
5a73c308 | 172 | return; |
1da177e4 LT |
173 | } |
174 | if (seclvl == -1) { | |
175 | seclvl_printk(1, KERN_WARNING, "Not allowed to advance to " | |
176 | "seclvl [%d]\n", seclvl); | |
5a73c308 | 177 | return; |
1da177e4 | 178 | } |
5a73c308 | 179 | seclvl = newlvl; /* would it be more "correct" to set *data? */ |
180 | return; | |
1da177e4 LT |
181 | } |
182 | ||
5a73c308 | 183 | static u64 seclvl_int_get(void *data) |
1da177e4 | 184 | { |
5a73c308 | 185 | return *(int *)data; |
1da177e4 LT |
186 | } |
187 | ||
5a73c308 | 188 | DEFINE_SIMPLE_ATTRIBUTE(seclvl_file_ops, seclvl_int_get, do_seclvl_advance, "%lld\n"); |
1da177e4 LT |
189 | |
190 | static unsigned char hashedPassword[SHA1_DIGEST_SIZE]; | |
191 | ||
1da177e4 LT |
192 | /** |
193 | * Converts a block of plaintext of into its SHA1 hashed value. | |
194 | * | |
195 | * It would be nice if crypto had a wrapper to do this for us linear | |
196 | * people... | |
197 | */ | |
198 | static int | |
6bb08da4 | 199 | plaintext_to_sha1(unsigned char *hash, const char *plaintext, unsigned int len) |
1da177e4 | 200 | { |
1da177e4 | 201 | struct crypto_tfm *tfm; |
6bb08da4 | 202 | struct scatterlist sg; |
1da177e4 LT |
203 | if (len > PAGE_SIZE) { |
204 | seclvl_printk(0, KERN_ERR, "Plaintext password too large (%d " | |
205 | "characters). Largest possible is %lu " | |
206 | "bytes.\n", len, PAGE_SIZE); | |
6bb08da4 | 207 | return -EINVAL; |
1da177e4 | 208 | } |
eb6f1160 | 209 | tfm = crypto_alloc_tfm("sha1", CRYPTO_TFM_REQ_MAY_SLEEP); |
1da177e4 LT |
210 | if (tfm == NULL) { |
211 | seclvl_printk(0, KERN_ERR, | |
212 | "Failed to load transform for SHA1\n"); | |
6bb08da4 | 213 | return -EINVAL; |
1da177e4 | 214 | } |
6bb08da4 | 215 | sg_init_one(&sg, (u8 *)plaintext, len); |
1da177e4 | 216 | crypto_digest_init(tfm); |
6bb08da4 | 217 | crypto_digest_update(tfm, &sg, 1); |
1da177e4 LT |
218 | crypto_digest_final(tfm, hash); |
219 | crypto_free_tfm(tfm); | |
1da177e4 LT |
220 | return 0; |
221 | } | |
222 | ||
223 | /** | |
224 | * Called whenever the user writes to the sysfs passwd handle to this kernel | |
225 | * object. It hashes the password and compares the hashed results. | |
226 | */ | |
227 | static ssize_t | |
5a73c308 | 228 | passwd_write_file(struct file * file, const char __user * buf, |
229 | size_t count, loff_t *ppos) | |
1da177e4 | 230 | { |
6bb08da4 | 231 | char *p; |
1da177e4 | 232 | int len; |
6bb08da4 | 233 | unsigned char tmp[SHA1_DIGEST_SIZE]; |
5a73c308 | 234 | |
1da177e4 LT |
235 | if (!*passwd && !*sha1_passwd) { |
236 | seclvl_printk(0, KERN_ERR, "Attempt to password-unlock the " | |
237 | "seclvl module, but neither a plain text " | |
238 | "password nor a SHA1 hashed password was " | |
239 | "passed in as a module parameter! This is a " | |
240 | "bug, since it should not be possible to be in " | |
241 | "this part of the module; please tell a " | |
242 | "maintainer about this event.\n"); | |
243 | return -EINVAL; | |
244 | } | |
5a73c308 | 245 | |
6bb08da4 | 246 | if (count >= PAGE_SIZE) |
9afa57b0 | 247 | return -EINVAL; |
d15c5749 | 248 | if (*ppos != 0) |
5a73c308 | 249 | return -EINVAL; |
6bb08da4 DA |
250 | p = kmalloc(count, GFP_KERNEL); |
251 | if (!p) | |
5a73c308 | 252 | return -ENOMEM; |
253 | len = -EFAULT; | |
6bb08da4 | 254 | if (copy_from_user(p, buf, count)) |
5a73c308 | 255 | goto out; |
256 | ||
6bb08da4 | 257 | len = count; |
1da177e4 | 258 | /* ``echo "secret" > seclvl/passwd'' includes a newline */ |
6bb08da4 | 259 | if (p[len - 1] == '\n') |
1da177e4 | 260 | len--; |
1da177e4 | 261 | /* Hash the password, then compare the hashed values */ |
6bb08da4 | 262 | if ((len = plaintext_to_sha1(tmp, p, len))) { |
1da177e4 | 263 | seclvl_printk(0, KERN_ERR, "Error hashing password: rc = " |
6bb08da4 DA |
264 | "[%d]\n", len); |
265 | goto out; | |
1da177e4 | 266 | } |
6bb08da4 DA |
267 | |
268 | len = -EPERM; | |
269 | if (memcmp(hashedPassword, tmp, SHA1_DIGEST_SIZE)) | |
270 | goto out; | |
271 | ||
1da177e4 LT |
272 | seclvl_printk(0, KERN_INFO, |
273 | "Password accepted; seclvl reduced to 0.\n"); | |
274 | seclvl = 0; | |
5a73c308 | 275 | len = count; |
276 | ||
277 | out: | |
6bb08da4 | 278 | kfree (p); |
5a73c308 | 279 | return len; |
1da177e4 LT |
280 | } |
281 | ||
5a73c308 | 282 | static struct file_operations passwd_file_ops = { |
283 | .write = passwd_write_file, | |
284 | }; | |
1da177e4 LT |
285 | |
286 | /** | |
287 | * Explicitely disallow ptrace'ing the init process. | |
288 | */ | |
289 | static int seclvl_ptrace(struct task_struct *parent, struct task_struct *child) | |
290 | { | |
6bb08da4 DA |
291 | if (seclvl >= 0 && child->pid == 1) { |
292 | seclvl_printk(1, KERN_WARNING, "Attempt to ptrace " | |
293 | "the init process dissallowed in " | |
294 | "secure level %d\n", seclvl); | |
295 | return -EPERM; | |
1da177e4 LT |
296 | } |
297 | return 0; | |
298 | } | |
299 | ||
300 | /** | |
301 | * Capability checks for seclvl. The majority of the policy | |
302 | * enforcement for seclvl takes place here. | |
303 | */ | |
304 | static int seclvl_capable(struct task_struct *tsk, int cap) | |
305 | { | |
6bb08da4 DA |
306 | int rc = 0; |
307 | ||
1da177e4 LT |
308 | /* init can do anything it wants */ |
309 | if (tsk->pid == 1) | |
310 | return 0; | |
311 | ||
6bb08da4 DA |
312 | if (seclvl > 0) { |
313 | rc = -EPERM; | |
314 | ||
315 | if (cap == CAP_LINUX_IMMUTABLE) | |
1da177e4 LT |
316 | seclvl_printk(1, KERN_WARNING, "Attempt to modify " |
317 | "the IMMUTABLE and/or APPEND extended " | |
318 | "attribute on a file with the IMMUTABLE " | |
319 | "and/or APPEND extended attribute set " | |
320 | "denied in seclvl [%d]\n", seclvl); | |
6bb08da4 | 321 | else if (cap == CAP_SYS_RAWIO) |
1da177e4 LT |
322 | seclvl_printk(1, KERN_WARNING, "Attempt to perform " |
323 | "raw I/O while in secure level [%d] " | |
324 | "denied\n", seclvl); | |
6bb08da4 | 325 | else if (cap == CAP_NET_ADMIN) |
1da177e4 LT |
326 | seclvl_printk(1, KERN_WARNING, "Attempt to perform " |
327 | "network administrative task while " | |
328 | "in secure level [%d] denied\n", seclvl); | |
6bb08da4 | 329 | else if (cap == CAP_SETUID) |
1da177e4 LT |
330 | seclvl_printk(1, KERN_WARNING, "Attempt to setuid " |
331 | "while in secure level [%d] denied\n", | |
332 | seclvl); | |
6bb08da4 | 333 | else if (cap == CAP_SETGID) |
1da177e4 LT |
334 | seclvl_printk(1, KERN_WARNING, "Attempt to setgid " |
335 | "while in secure level [%d] denied\n", | |
336 | seclvl); | |
6bb08da4 | 337 | else if (cap == CAP_SYS_MODULE) |
1da177e4 LT |
338 | seclvl_printk(1, KERN_WARNING, "Attempt to perform " |
339 | "a module operation while in secure " | |
340 | "level [%d] denied\n", seclvl); | |
6bb08da4 DA |
341 | else |
342 | rc = 0; | |
1da177e4 | 343 | } |
6bb08da4 DA |
344 | |
345 | if (!rc) { | |
346 | if (!(cap_is_fs_cap(cap) ? tsk->fsuid == 0 : tsk->euid == 0)) | |
347 | rc = -EPERM; | |
348 | } | |
349 | ||
350 | if (rc) | |
351 | seclvl_printk(1, KERN_WARNING, "Capability denied\n"); | |
352 | ||
353 | return rc; | |
1da177e4 LT |
354 | } |
355 | ||
356 | /** | |
357 | * Disallow reversing the clock in seclvl > 1 | |
358 | */ | |
359 | static int seclvl_settime(struct timespec *tv, struct timezone *tz) | |
360 | { | |
951069e3 LT |
361 | if (tv && seclvl > 1) { |
362 | struct timespec now; | |
1da177e4 LT |
363 | now = current_kernel_time(); |
364 | if (tv->tv_sec < now.tv_sec || | |
365 | (tv->tv_sec == now.tv_sec && tv->tv_nsec < now.tv_nsec)) { | |
366 | seclvl_printk(1, KERN_WARNING, "Attempt to decrement " | |
367 | "time in secure level %d denied: " | |
368 | "current->pid = [%d], " | |
369 | "current->group_leader->pid = [%d]\n", | |
370 | seclvl, current->pid, | |
371 | current->group_leader->pid); | |
372 | return -EPERM; | |
373 | } /* if attempt to decrement time */ | |
374 | } /* if seclvl > 1 */ | |
375 | return 0; | |
376 | } | |
377 | ||
378 | /* claim the blockdev to exclude mounters, release on file close */ | |
379 | static int seclvl_bd_claim(struct inode *inode) | |
380 | { | |
381 | int holder; | |
382 | struct block_device *bdev = NULL; | |
383 | dev_t dev = inode->i_rdev; | |
384 | bdev = open_by_devnum(dev, FMODE_WRITE); | |
385 | if (bdev) { | |
386 | if (bd_claim(bdev, &holder)) { | |
387 | blkdev_put(bdev); | |
388 | return -EPERM; | |
389 | } | |
390 | /* claimed, mark it to release on close */ | |
391 | inode->i_security = current; | |
392 | } | |
393 | return 0; | |
394 | } | |
395 | ||
396 | /* release the blockdev if you claimed it */ | |
397 | static void seclvl_bd_release(struct inode *inode) | |
398 | { | |
399 | if (inode && S_ISBLK(inode->i_mode) && inode->i_security == current) { | |
400 | struct block_device *bdev = inode->i_bdev; | |
401 | if (bdev) { | |
402 | bd_release(bdev); | |
403 | blkdev_put(bdev); | |
404 | inode->i_security = NULL; | |
405 | } | |
406 | } | |
407 | } | |
408 | ||
409 | /** | |
410 | * Security for writes to block devices is regulated by this seclvl | |
411 | * function. Deny all writes to block devices in seclvl 2. In | |
412 | * seclvl 1, we only deny writes to *mounted* block devices. | |
413 | */ | |
414 | static int | |
415 | seclvl_inode_permission(struct inode *inode, int mask, struct nameidata *nd) | |
416 | { | |
417 | if (current->pid != 1 && S_ISBLK(inode->i_mode) && (mask & MAY_WRITE)) { | |
418 | switch (seclvl) { | |
419 | case 2: | |
420 | seclvl_printk(1, KERN_WARNING, "Write to block device " | |
421 | "denied in secure level [%d]\n", seclvl); | |
422 | return -EPERM; | |
423 | case 1: | |
424 | if (seclvl_bd_claim(inode)) { | |
425 | seclvl_printk(1, KERN_WARNING, | |
426 | "Write to mounted block device " | |
427 | "denied in secure level [%d]\n", | |
428 | seclvl); | |
429 | return -EPERM; | |
430 | } | |
431 | } | |
432 | } | |
433 | return 0; | |
434 | } | |
435 | ||
436 | /** | |
437 | * The SUID and SGID bits cannot be set in seclvl >= 1 | |
438 | */ | |
439 | static int seclvl_inode_setattr(struct dentry *dentry, struct iattr *iattr) | |
440 | { | |
441 | if (seclvl > 0) { | |
442 | if (iattr->ia_valid & ATTR_MODE) | |
443 | if (iattr->ia_mode & S_ISUID || | |
444 | iattr->ia_mode & S_ISGID) { | |
445 | seclvl_printk(1, KERN_WARNING, "Attempt to " | |
446 | "modify SUID or SGID bit " | |
447 | "denied in seclvl [%d]\n", | |
448 | seclvl); | |
449 | return -EPERM; | |
450 | } | |
451 | } | |
452 | return 0; | |
453 | } | |
454 | ||
455 | /* release busied block devices */ | |
456 | static void seclvl_file_free_security(struct file *filp) | |
457 | { | |
458 | struct dentry *dentry = filp->f_dentry; | |
1da177e4 | 459 | |
6bb08da4 DA |
460 | if (dentry) |
461 | seclvl_bd_release(dentry->d_inode); | |
1da177e4 LT |
462 | } |
463 | ||
464 | /** | |
465 | * Cannot unmount in secure level 2 | |
466 | */ | |
467 | static int seclvl_umount(struct vfsmount *mnt, int flags) | |
468 | { | |
6bb08da4 | 469 | if (current->pid != 1 && seclvl == 2) { |
1da177e4 LT |
470 | seclvl_printk(1, KERN_WARNING, "Attempt to unmount in secure " |
471 | "level %d\n", seclvl); | |
472 | return -EPERM; | |
473 | } | |
474 | return 0; | |
475 | } | |
476 | ||
477 | static struct security_operations seclvl_ops = { | |
478 | .ptrace = seclvl_ptrace, | |
479 | .capable = seclvl_capable, | |
480 | .inode_permission = seclvl_inode_permission, | |
481 | .inode_setattr = seclvl_inode_setattr, | |
482 | .file_free_security = seclvl_file_free_security, | |
483 | .settime = seclvl_settime, | |
484 | .sb_umount = seclvl_umount, | |
485 | }; | |
486 | ||
487 | /** | |
488 | * Process the password-related module parameters | |
489 | */ | |
490 | static int processPassword(void) | |
491 | { | |
492 | int rc = 0; | |
1da177e4 | 493 | if (*passwd) { |
6bb08da4 DA |
494 | char *p; |
495 | ||
1da177e4 LT |
496 | if (*sha1_passwd) { |
497 | seclvl_printk(0, KERN_ERR, "Error: Both " | |
498 | "passwd and sha1_passwd " | |
499 | "were set, but they are mutually " | |
500 | "exclusive.\n"); | |
501 | return -EINVAL; | |
502 | } | |
6bb08da4 DA |
503 | |
504 | p = kstrdup(passwd, GFP_KERNEL); | |
505 | if (p == NULL) | |
506 | return -ENOMEM; | |
507 | ||
508 | if ((rc = plaintext_to_sha1(hashedPassword, p, strlen(p)))) | |
1da177e4 LT |
509 | seclvl_printk(0, KERN_ERR, "Error: SHA1 support not " |
510 | "in kernel\n"); | |
6bb08da4 DA |
511 | |
512 | kfree (p); | |
1da177e4 LT |
513 | /* All static data goes to the BSS, which zero's the |
514 | * plaintext password out for us. */ | |
515 | } else if (*sha1_passwd) { // Base 16 | |
516 | int i; | |
517 | i = strlen(sha1_passwd); | |
518 | if (i != (SHA1_DIGEST_SIZE * 2)) { | |
519 | seclvl_printk(0, KERN_ERR, "Received [%d] bytes; " | |
520 | "expected [%d] for the hexadecimal " | |
521 | "representation of the SHA1 hash of " | |
522 | "the password.\n", | |
523 | i, (SHA1_DIGEST_SIZE * 2)); | |
524 | return -EINVAL; | |
525 | } | |
526 | while ((i -= 2) + 2) { | |
527 | unsigned char tmp; | |
528 | tmp = sha1_passwd[i + 2]; | |
529 | sha1_passwd[i + 2] = '\0'; | |
530 | hashedPassword[i / 2] = (unsigned char) | |
531 | simple_strtol(&sha1_passwd[i], NULL, 16); | |
532 | sha1_passwd[i + 2] = tmp; | |
533 | } | |
534 | } | |
6bb08da4 | 535 | return rc; |
1da177e4 LT |
536 | } |
537 | ||
538 | /** | |
5a73c308 | 539 | * securityfs registrations |
1da177e4 | 540 | */ |
5a73c308 | 541 | struct dentry *dir_ino, *seclvl_ino, *passwd_ino; |
542 | ||
543 | static int seclvlfs_register(void) | |
1da177e4 | 544 | { |
6bb08da4 DA |
545 | int rc = 0; |
546 | ||
5a73c308 | 547 | dir_ino = securityfs_create_dir("seclvl", NULL); |
6bb08da4 DA |
548 | |
549 | if (IS_ERR(dir_ino)) | |
550 | return PTR_ERR(dir_ino); | |
5a73c308 | 551 | |
552 | seclvl_ino = securityfs_create_file("seclvl", S_IRUGO | S_IWUSR, | |
553 | dir_ino, &seclvl, &seclvl_file_ops); | |
6bb08da4 DA |
554 | if (IS_ERR(seclvl_ino)) { |
555 | rc = PTR_ERR(seclvl_ino); | |
5a73c308 | 556 | goto out_deldir; |
6bb08da4 | 557 | } |
1da177e4 | 558 | if (*passwd || *sha1_passwd) { |
5a73c308 | 559 | passwd_ino = securityfs_create_file("passwd", S_IRUGO | S_IWUSR, |
560 | dir_ino, NULL, &passwd_file_ops); | |
6bb08da4 DA |
561 | if (IS_ERR(passwd_ino)) { |
562 | rc = PTR_ERR(passwd_ino); | |
5a73c308 | 563 | goto out_delf; |
6bb08da4 | 564 | } |
1da177e4 | 565 | } |
6bb08da4 DA |
566 | return rc; |
567 | ||
568 | out_delf: | |
569 | securityfs_remove(seclvl_ino); | |
5a73c308 | 570 | |
571 | out_deldir: | |
572 | securityfs_remove(dir_ino); | |
6bb08da4 DA |
573 | |
574 | return rc; | |
575 | } | |
576 | ||
577 | static void seclvlfs_unregister(void) | |
578 | { | |
5a73c308 | 579 | securityfs_remove(seclvl_ino); |
580 | ||
6bb08da4 DA |
581 | if (*passwd || *sha1_passwd) |
582 | securityfs_remove(passwd_ino); | |
583 | ||
584 | securityfs_remove(dir_ino); | |
1da177e4 LT |
585 | } |
586 | ||
587 | /** | |
588 | * Initialize the seclvl module. | |
589 | */ | |
590 | static int __init seclvl_init(void) | |
591 | { | |
592 | int rc = 0; | |
6bb08da4 DA |
593 | static char once; |
594 | ||
1da177e4 LT |
595 | if (verbosity < 0 || verbosity > 1) { |
596 | printk(KERN_ERR "Error: bad verbosity [%d]; only 0 or 1 " | |
597 | "are valid values\n", verbosity); | |
598 | rc = -EINVAL; | |
599 | goto exit; | |
600 | } | |
1da177e4 LT |
601 | if (initlvl < -1 || initlvl > 2) { |
602 | seclvl_printk(0, KERN_ERR, "Error: bad initial securelevel " | |
603 | "[%d].\n", initlvl); | |
604 | rc = -EINVAL; | |
605 | goto exit; | |
606 | } | |
607 | seclvl = initlvl; | |
608 | if ((rc = processPassword())) { | |
609 | seclvl_printk(0, KERN_ERR, "Error processing the password " | |
610 | "module parameter(s): rc = [%d]\n", rc); | |
611 | goto exit; | |
612 | } | |
6bb08da4 DA |
613 | |
614 | if ((rc = seclvlfs_register())) { | |
615 | seclvl_printk(0, KERN_ERR, "Error registering with sysfs\n"); | |
616 | goto exit; | |
617 | } | |
1da177e4 LT |
618 | /* register ourselves with the security framework */ |
619 | if (register_security(&seclvl_ops)) { | |
620 | seclvl_printk(0, KERN_ERR, | |
621 | "seclvl: Failure registering with the " | |
622 | "kernel.\n"); | |
623 | /* try registering with primary module */ | |
624 | rc = mod_reg_security(MY_NAME, &seclvl_ops); | |
625 | if (rc) { | |
626 | seclvl_printk(0, KERN_ERR, "seclvl: Failure " | |
627 | "registering with primary security " | |
628 | "module.\n"); | |
6bb08da4 | 629 | seclvlfs_unregister(); |
1da177e4 LT |
630 | goto exit; |
631 | } /* if primary module registered */ | |
632 | secondary = 1; | |
633 | } /* if we registered ourselves with the security framework */ | |
6bb08da4 | 634 | |
1da177e4 | 635 | seclvl_printk(0, KERN_INFO, "seclvl: Successfully initialized.\n"); |
6bb08da4 DA |
636 | |
637 | if (once) { | |
638 | once = 1; | |
639 | seclvl_printk(0, KERN_INFO, "seclvl is going away. It has been " | |
640 | "buggy for ages. Also, be warned that " | |
641 | "Securelevels are useless."); | |
642 | } | |
1da177e4 | 643 | exit: |
6bb08da4 | 644 | if (rc) |
1da177e4 LT |
645 | printk(KERN_ERR "seclvl: Error during initialization: rc = " |
646 | "[%d]\n", rc); | |
1da177e4 LT |
647 | return rc; |
648 | } | |
649 | ||
650 | /** | |
651 | * Remove the seclvl module. | |
652 | */ | |
653 | static void __exit seclvl_exit(void) | |
654 | { | |
6bb08da4 DA |
655 | seclvlfs_unregister(); |
656 | ||
657 | if (secondary) | |
1da177e4 | 658 | mod_unreg_security(MY_NAME, &seclvl_ops); |
6bb08da4 | 659 | else if (unregister_security(&seclvl_ops)) |
1da177e4 LT |
660 | seclvl_printk(0, KERN_INFO, |
661 | "seclvl: Failure unregistering with the " | |
662 | "kernel\n"); | |
1da177e4 LT |
663 | } |
664 | ||
665 | module_init(seclvl_init); | |
666 | module_exit(seclvl_exit); | |
667 | ||
668 | MODULE_AUTHOR("Michael A. Halcrow <mike@halcrow.us>"); | |
669 | MODULE_DESCRIPTION("LSM implementation of the BSD Secure Levels"); | |
670 | MODULE_LICENSE("GPL"); |