Commit | Line | Data |
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8d7b48e0 IK |
1 | /* |
2 | * Copyright 2008 Red Hat, Inc. All rights reserved. | |
3 | * Copyright 2008 Ian Kent <raven@themaw.net> | |
4 | * | |
5 | * This file is part of the Linux kernel and is made available under | |
6 | * the terms of the GNU General Public License, version 2, or at your | |
7 | * option, any later version, incorporated herein by reference. | |
8 | */ | |
9 | ||
10 | #include <linux/module.h> | |
11 | #include <linux/vmalloc.h> | |
12 | #include <linux/miscdevice.h> | |
13 | #include <linux/init.h> | |
14 | #include <linux/wait.h> | |
15 | #include <linux/namei.h> | |
16 | #include <linux/fcntl.h> | |
17 | #include <linux/file.h> | |
18 | #include <linux/fdtable.h> | |
19 | #include <linux/sched.h> | |
20 | #include <linux/compat.h> | |
21 | #include <linux/syscalls.h> | |
8d7b48e0 IK |
22 | #include <linux/magic.h> |
23 | #include <linux/dcache.h> | |
24 | #include <linux/uaccess.h> | |
25 | ||
26 | #include "autofs_i.h" | |
27 | ||
28 | /* | |
29 | * This module implements an interface for routing autofs ioctl control | |
30 | * commands via a miscellaneous device file. | |
31 | * | |
32 | * The alternate interface is needed because we need to be able open | |
33 | * an ioctl file descriptor on an autofs mount that may be covered by | |
34 | * another mount. This situation arises when starting automount(8) | |
35 | * or other user space daemon which uses direct mounts or offset | |
36 | * mounts (used for autofs lazy mount/umount of nested mount trees), | |
37 | * which have been left busy at at service shutdown. | |
38 | */ | |
39 | ||
40 | #define AUTOFS_DEV_IOCTL_SIZE sizeof(struct autofs_dev_ioctl) | |
41 | ||
42 | typedef int (*ioctl_fn)(struct file *, struct autofs_sb_info *, | |
43 | struct autofs_dev_ioctl *); | |
44 | ||
45 | static int check_name(const char *name) | |
46 | { | |
47 | if (!strchr(name, '/')) | |
48 | return -EINVAL; | |
49 | return 0; | |
50 | } | |
51 | ||
52 | /* | |
53 | * Check a string doesn't overrun the chunk of | |
54 | * memory we copied from user land. | |
55 | */ | |
3eac8778 | 56 | static int invalid_str(char *str, size_t size) |
8d7b48e0 | 57 | { |
3eac8778 AV |
58 | if (memchr(str, 0, size)) |
59 | return 0; | |
8d7b48e0 IK |
60 | return -EINVAL; |
61 | } | |
62 | ||
63 | /* | |
64 | * Check that the user compiled against correct version of autofs | |
65 | * misc device code. | |
66 | * | |
67 | * As well as checking the version compatibility this always copies | |
68 | * the kernel interface version out. | |
69 | */ | |
70 | static int check_dev_ioctl_version(int cmd, struct autofs_dev_ioctl *param) | |
71 | { | |
72 | int err = 0; | |
73 | ||
74 | if ((AUTOFS_DEV_IOCTL_VERSION_MAJOR != param->ver_major) || | |
75 | (AUTOFS_DEV_IOCTL_VERSION_MINOR < param->ver_minor)) { | |
76 | AUTOFS_WARN("ioctl control interface version mismatch: " | |
77 | "kernel(%u.%u), user(%u.%u), cmd(%d)", | |
78 | AUTOFS_DEV_IOCTL_VERSION_MAJOR, | |
79 | AUTOFS_DEV_IOCTL_VERSION_MINOR, | |
80 | param->ver_major, param->ver_minor, cmd); | |
81 | err = -EINVAL; | |
82 | } | |
83 | ||
84 | /* Fill in the kernel version. */ | |
85 | param->ver_major = AUTOFS_DEV_IOCTL_VERSION_MAJOR; | |
86 | param->ver_minor = AUTOFS_DEV_IOCTL_VERSION_MINOR; | |
87 | ||
88 | return err; | |
89 | } | |
90 | ||
91 | /* | |
92 | * Copy parameter control struct, including a possible path allocated | |
93 | * at the end of the struct. | |
94 | */ | |
95 | static struct autofs_dev_ioctl *copy_dev_ioctl(struct autofs_dev_ioctl __user *in) | |
96 | { | |
97 | struct autofs_dev_ioctl tmp, *ads; | |
98 | ||
99 | if (copy_from_user(&tmp, in, sizeof(tmp))) | |
100 | return ERR_PTR(-EFAULT); | |
101 | ||
102 | if (tmp.size < sizeof(tmp)) | |
103 | return ERR_PTR(-EINVAL); | |
104 | ||
105 | ads = kmalloc(tmp.size, GFP_KERNEL); | |
106 | if (!ads) | |
107 | return ERR_PTR(-ENOMEM); | |
108 | ||
109 | if (copy_from_user(ads, in, tmp.size)) { | |
110 | kfree(ads); | |
111 | return ERR_PTR(-EFAULT); | |
112 | } | |
113 | ||
114 | return ads; | |
115 | } | |
116 | ||
117 | static inline void free_dev_ioctl(struct autofs_dev_ioctl *param) | |
118 | { | |
119 | kfree(param); | |
120 | return; | |
121 | } | |
122 | ||
123 | /* | |
124 | * Check sanity of parameter control fields and if a path is present | |
bae8ec66 | 125 | * check that it is terminated and contains at least one "/". |
8d7b48e0 IK |
126 | */ |
127 | static int validate_dev_ioctl(int cmd, struct autofs_dev_ioctl *param) | |
128 | { | |
96b03179 | 129 | int err; |
8d7b48e0 | 130 | |
96b03179 IK |
131 | err = check_dev_ioctl_version(cmd, param); |
132 | if (err) { | |
8d7b48e0 IK |
133 | AUTOFS_WARN("invalid device control module version " |
134 | "supplied for cmd(0x%08x)", cmd); | |
135 | goto out; | |
136 | } | |
137 | ||
138 | if (param->size > sizeof(*param)) { | |
3eac8778 | 139 | err = invalid_str(param->path, param->size - sizeof(*param)); |
8d7b48e0 | 140 | if (err) { |
bae8ec66 IK |
141 | AUTOFS_WARN( |
142 | "path string terminator missing for cmd(0x%08x)", | |
143 | cmd); | |
8d7b48e0 IK |
144 | goto out; |
145 | } | |
146 | ||
bae8ec66 | 147 | err = check_name(param->path); |
8d7b48e0 IK |
148 | if (err) { |
149 | AUTOFS_WARN("invalid path supplied for cmd(0x%08x)", | |
150 | cmd); | |
151 | goto out; | |
152 | } | |
153 | } | |
154 | ||
155 | err = 0; | |
156 | out: | |
157 | return err; | |
158 | } | |
159 | ||
160 | /* | |
161 | * Get the autofs super block info struct from the file opened on | |
162 | * the autofs mount point. | |
163 | */ | |
164 | static struct autofs_sb_info *autofs_dev_ioctl_sbi(struct file *f) | |
165 | { | |
166 | struct autofs_sb_info *sbi = NULL; | |
167 | struct inode *inode; | |
168 | ||
169 | if (f) { | |
170 | inode = f->f_path.dentry->d_inode; | |
171 | sbi = autofs4_sbi(inode->i_sb); | |
172 | } | |
173 | return sbi; | |
174 | } | |
175 | ||
176 | /* Return autofs module protocol version */ | |
177 | static int autofs_dev_ioctl_protover(struct file *fp, | |
178 | struct autofs_sb_info *sbi, | |
179 | struct autofs_dev_ioctl *param) | |
180 | { | |
730c9eec | 181 | param->protover.version = sbi->version; |
8d7b48e0 IK |
182 | return 0; |
183 | } | |
184 | ||
185 | /* Return autofs module protocol sub version */ | |
186 | static int autofs_dev_ioctl_protosubver(struct file *fp, | |
187 | struct autofs_sb_info *sbi, | |
188 | struct autofs_dev_ioctl *param) | |
189 | { | |
730c9eec | 190 | param->protosubver.sub_version = sbi->sub_version; |
8d7b48e0 IK |
191 | return 0; |
192 | } | |
193 | ||
4e44b685 AV |
194 | static int find_autofs_mount(const char *pathname, |
195 | struct path *res, | |
196 | int test(struct path *path, void *data), | |
197 | void *data) | |
8d7b48e0 | 198 | { |
4e44b685 AV |
199 | struct path path; |
200 | int err = kern_path(pathname, 0, &path); | |
201 | if (err) | |
202 | return err; | |
8d7b48e0 | 203 | err = -ENOENT; |
4e44b685 AV |
204 | while (path.dentry == path.mnt->mnt_root) { |
205 | if (path.mnt->mnt_sb->s_magic == AUTOFS_SUPER_MAGIC) { | |
206 | if (test(&path, data)) { | |
207 | path_get(&path); | |
208 | if (!err) /* already found some */ | |
209 | path_put(res); | |
210 | *res = path; | |
8d7b48e0 | 211 | err = 0; |
8d7b48e0 IK |
212 | } |
213 | } | |
bab77ebf | 214 | if (!follow_up(&path)) |
4e44b685 | 215 | break; |
8d7b48e0 | 216 | } |
4e44b685 | 217 | path_put(&path); |
8d7b48e0 IK |
218 | return err; |
219 | } | |
220 | ||
4e44b685 | 221 | static int test_by_dev(struct path *path, void *p) |
8d7b48e0 | 222 | { |
4e44b685 AV |
223 | return path->mnt->mnt_sb->s_dev == *(dev_t *)p; |
224 | } | |
8d7b48e0 | 225 | |
4e44b685 AV |
226 | static int test_by_type(struct path *path, void *p) |
227 | { | |
228 | struct autofs_info *ino = autofs4_dentry_ino(path->dentry); | |
229 | return ino && ino->sbi->type & *(unsigned *)p; | |
8d7b48e0 IK |
230 | } |
231 | ||
232 | static void autofs_dev_ioctl_fd_install(unsigned int fd, struct file *file) | |
233 | { | |
234 | struct files_struct *files = current->files; | |
235 | struct fdtable *fdt; | |
236 | ||
237 | spin_lock(&files->file_lock); | |
238 | fdt = files_fdtable(files); | |
239 | BUG_ON(fdt->fd[fd] != NULL); | |
240 | rcu_assign_pointer(fdt->fd[fd], file); | |
241 | FD_SET(fd, fdt->close_on_exec); | |
242 | spin_unlock(&files->file_lock); | |
243 | } | |
244 | ||
245 | ||
246 | /* | |
247 | * Open a file descriptor on the autofs mount point corresponding | |
248 | * to the given path and device number (aka. new_encode_dev(sb->s_dev)). | |
249 | */ | |
4e44b685 | 250 | static int autofs_dev_ioctl_open_mountpoint(const char *name, dev_t devid) |
8d7b48e0 | 251 | { |
8d7b48e0 IK |
252 | int err, fd; |
253 | ||
254 | fd = get_unused_fd(); | |
255 | if (likely(fd >= 0)) { | |
4e44b685 AV |
256 | struct file *filp; |
257 | struct path path; | |
258 | ||
259 | err = find_autofs_mount(name, &path, test_by_dev, &devid); | |
8d7b48e0 IK |
260 | if (err) |
261 | goto out; | |
262 | ||
263 | /* | |
4e44b685 | 264 | * Find autofs super block that has the device number |
8d7b48e0 IK |
265 | * corresponding to the autofs fs we want to open. |
266 | */ | |
8d7b48e0 | 267 | |
4e44b685 | 268 | filp = dentry_open(path.dentry, path.mnt, O_RDONLY, |
745ca247 | 269 | current_cred()); |
8d7b48e0 IK |
270 | if (IS_ERR(filp)) { |
271 | err = PTR_ERR(filp); | |
272 | goto out; | |
273 | } | |
274 | ||
275 | autofs_dev_ioctl_fd_install(fd, filp); | |
276 | } | |
277 | ||
278 | return fd; | |
279 | ||
280 | out: | |
281 | put_unused_fd(fd); | |
282 | return err; | |
283 | } | |
284 | ||
285 | /* Open a file descriptor on an autofs mount point */ | |
286 | static int autofs_dev_ioctl_openmount(struct file *fp, | |
287 | struct autofs_sb_info *sbi, | |
288 | struct autofs_dev_ioctl *param) | |
289 | { | |
290 | const char *path; | |
291 | dev_t devid; | |
292 | int err, fd; | |
293 | ||
294 | /* param->path has already been checked */ | |
730c9eec | 295 | if (!param->openmount.devid) |
8d7b48e0 IK |
296 | return -EINVAL; |
297 | ||
298 | param->ioctlfd = -1; | |
299 | ||
300 | path = param->path; | |
4e44b685 | 301 | devid = new_decode_dev(param->openmount.devid); |
8d7b48e0 IK |
302 | |
303 | err = 0; | |
304 | fd = autofs_dev_ioctl_open_mountpoint(path, devid); | |
305 | if (unlikely(fd < 0)) { | |
306 | err = fd; | |
307 | goto out; | |
308 | } | |
309 | ||
310 | param->ioctlfd = fd; | |
311 | out: | |
312 | return err; | |
313 | } | |
314 | ||
315 | /* Close file descriptor allocated above (user can also use close(2)). */ | |
316 | static int autofs_dev_ioctl_closemount(struct file *fp, | |
317 | struct autofs_sb_info *sbi, | |
318 | struct autofs_dev_ioctl *param) | |
319 | { | |
320 | return sys_close(param->ioctlfd); | |
321 | } | |
322 | ||
323 | /* | |
324 | * Send "ready" status for an existing wait (either a mount or an expire | |
325 | * request). | |
326 | */ | |
327 | static int autofs_dev_ioctl_ready(struct file *fp, | |
328 | struct autofs_sb_info *sbi, | |
329 | struct autofs_dev_ioctl *param) | |
330 | { | |
331 | autofs_wqt_t token; | |
332 | ||
730c9eec | 333 | token = (autofs_wqt_t) param->ready.token; |
8d7b48e0 IK |
334 | return autofs4_wait_release(sbi, token, 0); |
335 | } | |
336 | ||
337 | /* | |
338 | * Send "fail" status for an existing wait (either a mount or an expire | |
339 | * request). | |
340 | */ | |
341 | static int autofs_dev_ioctl_fail(struct file *fp, | |
342 | struct autofs_sb_info *sbi, | |
343 | struct autofs_dev_ioctl *param) | |
344 | { | |
345 | autofs_wqt_t token; | |
346 | int status; | |
347 | ||
730c9eec IK |
348 | token = (autofs_wqt_t) param->fail.token; |
349 | status = param->fail.status ? param->fail.status : -ENOENT; | |
8d7b48e0 IK |
350 | return autofs4_wait_release(sbi, token, status); |
351 | } | |
352 | ||
353 | /* | |
354 | * Set the pipe fd for kernel communication to the daemon. | |
355 | * | |
356 | * Normally this is set at mount using an option but if we | |
357 | * are reconnecting to a busy mount then we need to use this | |
358 | * to tell the autofs mount about the new kernel pipe fd. In | |
359 | * order to protect mounts against incorrectly setting the | |
360 | * pipefd we also require that the autofs mount be catatonic. | |
361 | * | |
362 | * This also sets the process group id used to identify the | |
363 | * controlling process (eg. the owning automount(8) daemon). | |
364 | */ | |
365 | static int autofs_dev_ioctl_setpipefd(struct file *fp, | |
366 | struct autofs_sb_info *sbi, | |
367 | struct autofs_dev_ioctl *param) | |
368 | { | |
369 | int pipefd; | |
370 | int err = 0; | |
371 | ||
730c9eec | 372 | if (param->setpipefd.pipefd == -1) |
8d7b48e0 IK |
373 | return -EINVAL; |
374 | ||
730c9eec | 375 | pipefd = param->setpipefd.pipefd; |
8d7b48e0 IK |
376 | |
377 | mutex_lock(&sbi->wq_mutex); | |
378 | if (!sbi->catatonic) { | |
379 | mutex_unlock(&sbi->wq_mutex); | |
380 | return -EBUSY; | |
381 | } else { | |
382 | struct file *pipe = fget(pipefd); | |
383 | if (!pipe->f_op || !pipe->f_op->write) { | |
384 | err = -EPIPE; | |
385 | fput(pipe); | |
386 | goto out; | |
387 | } | |
388 | sbi->oz_pgrp = task_pgrp_nr(current); | |
389 | sbi->pipefd = pipefd; | |
390 | sbi->pipe = pipe; | |
391 | sbi->catatonic = 0; | |
392 | } | |
393 | out: | |
394 | mutex_unlock(&sbi->wq_mutex); | |
395 | return err; | |
396 | } | |
397 | ||
398 | /* | |
399 | * Make the autofs mount point catatonic, no longer responsive to | |
400 | * mount requests. Also closes the kernel pipe file descriptor. | |
401 | */ | |
402 | static int autofs_dev_ioctl_catatonic(struct file *fp, | |
403 | struct autofs_sb_info *sbi, | |
404 | struct autofs_dev_ioctl *param) | |
405 | { | |
406 | autofs4_catatonic_mode(sbi); | |
407 | return 0; | |
408 | } | |
409 | ||
410 | /* Set the autofs mount timeout */ | |
411 | static int autofs_dev_ioctl_timeout(struct file *fp, | |
412 | struct autofs_sb_info *sbi, | |
413 | struct autofs_dev_ioctl *param) | |
414 | { | |
415 | unsigned long timeout; | |
416 | ||
730c9eec IK |
417 | timeout = param->timeout.timeout; |
418 | param->timeout.timeout = sbi->exp_timeout / HZ; | |
8d7b48e0 IK |
419 | sbi->exp_timeout = timeout * HZ; |
420 | return 0; | |
421 | } | |
422 | ||
423 | /* | |
424 | * Return the uid and gid of the last request for the mount | |
425 | * | |
426 | * When reconstructing an autofs mount tree with active mounts | |
427 | * we need to re-connect to mounts that may have used the original | |
428 | * process uid and gid (or string variations of them) for mount | |
429 | * lookups within the map entry. | |
430 | */ | |
431 | static int autofs_dev_ioctl_requester(struct file *fp, | |
432 | struct autofs_sb_info *sbi, | |
433 | struct autofs_dev_ioctl *param) | |
434 | { | |
435 | struct autofs_info *ino; | |
4e44b685 | 436 | struct path path; |
8d7b48e0 IK |
437 | dev_t devid; |
438 | int err = -ENOENT; | |
439 | ||
440 | if (param->size <= sizeof(*param)) { | |
441 | err = -EINVAL; | |
442 | goto out; | |
443 | } | |
444 | ||
4e44b685 | 445 | devid = sbi->sb->s_dev; |
8d7b48e0 | 446 | |
730c9eec | 447 | param->requester.uid = param->requester.gid = -1; |
8d7b48e0 | 448 | |
4e44b685 | 449 | err = find_autofs_mount(param->path, &path, test_by_dev, &devid); |
8d7b48e0 IK |
450 | if (err) |
451 | goto out; | |
452 | ||
4e44b685 | 453 | ino = autofs4_dentry_ino(path.dentry); |
8d7b48e0 IK |
454 | if (ino) { |
455 | err = 0; | |
4e44b685 | 456 | autofs4_expire_wait(path.dentry); |
8d7b48e0 | 457 | spin_lock(&sbi->fs_lock); |
730c9eec IK |
458 | param->requester.uid = ino->uid; |
459 | param->requester.gid = ino->gid; | |
8d7b48e0 IK |
460 | spin_unlock(&sbi->fs_lock); |
461 | } | |
4e44b685 | 462 | path_put(&path); |
8d7b48e0 IK |
463 | out: |
464 | return err; | |
465 | } | |
466 | ||
467 | /* | |
468 | * Call repeatedly until it returns -EAGAIN, meaning there's nothing | |
469 | * more that can be done. | |
470 | */ | |
471 | static int autofs_dev_ioctl_expire(struct file *fp, | |
472 | struct autofs_sb_info *sbi, | |
473 | struct autofs_dev_ioctl *param) | |
474 | { | |
8d7b48e0 | 475 | struct vfsmount *mnt; |
8d7b48e0 IK |
476 | int how; |
477 | ||
730c9eec | 478 | how = param->expire.how; |
8d7b48e0 IK |
479 | mnt = fp->f_path.mnt; |
480 | ||
56fcef75 | 481 | return autofs4_do_expire_multi(sbi->sb, mnt, sbi, how); |
8d7b48e0 IK |
482 | } |
483 | ||
484 | /* Check if autofs mount point is in use */ | |
485 | static int autofs_dev_ioctl_askumount(struct file *fp, | |
486 | struct autofs_sb_info *sbi, | |
487 | struct autofs_dev_ioctl *param) | |
488 | { | |
730c9eec | 489 | param->askumount.may_umount = 0; |
8d7b48e0 | 490 | if (may_umount(fp->f_path.mnt)) |
730c9eec | 491 | param->askumount.may_umount = 1; |
8d7b48e0 IK |
492 | return 0; |
493 | } | |
494 | ||
495 | /* | |
496 | * Check if the given path is a mountpoint. | |
497 | * | |
498 | * If we are supplied with the file descriptor of an autofs | |
499 | * mount we're looking for a specific mount. In this case | |
500 | * the path is considered a mountpoint if it is itself a | |
501 | * mountpoint or contains a mount, such as a multi-mount | |
502 | * without a root mount. In this case we return 1 if the | |
503 | * path is a mount point and the super magic of the covering | |
504 | * mount if there is one or 0 if it isn't a mountpoint. | |
505 | * | |
506 | * If we aren't supplied with a file descriptor then we | |
507 | * lookup the nameidata of the path and check if it is the | |
508 | * root of a mount. If a type is given we are looking for | |
509 | * a particular autofs mount and if we don't find a match | |
510 | * we return fail. If the located nameidata path is the | |
511 | * root of a mount we return 1 along with the super magic | |
512 | * of the mount or 0 otherwise. | |
513 | * | |
514 | * In both cases the the device number (as returned by | |
515 | * new_encode_dev()) is also returned. | |
516 | */ | |
517 | static int autofs_dev_ioctl_ismountpoint(struct file *fp, | |
518 | struct autofs_sb_info *sbi, | |
519 | struct autofs_dev_ioctl *param) | |
520 | { | |
4e44b685 AV |
521 | struct path path; |
522 | const char *name; | |
8d7b48e0 | 523 | unsigned int type; |
730c9eec | 524 | unsigned int devid, magic; |
8d7b48e0 IK |
525 | int err = -ENOENT; |
526 | ||
527 | if (param->size <= sizeof(*param)) { | |
528 | err = -EINVAL; | |
529 | goto out; | |
530 | } | |
531 | ||
4e44b685 | 532 | name = param->path; |
730c9eec | 533 | type = param->ismountpoint.in.type; |
8d7b48e0 | 534 | |
730c9eec IK |
535 | param->ismountpoint.out.devid = devid = 0; |
536 | param->ismountpoint.out.magic = magic = 0; | |
8d7b48e0 IK |
537 | |
538 | if (!fp || param->ioctlfd == -1) { | |
4e44b685 AV |
539 | if (autofs_type_any(type)) |
540 | err = kern_path(name, LOOKUP_FOLLOW, &path); | |
541 | else | |
542 | err = find_autofs_mount(name, &path, test_by_type, &type); | |
543 | if (err) | |
544 | goto out; | |
545 | devid = new_encode_dev(path.mnt->mnt_sb->s_dev); | |
8d7b48e0 | 546 | err = 0; |
4e44b685 AV |
547 | if (path.dentry->d_inode && |
548 | path.mnt->mnt_root == path.dentry) { | |
8d7b48e0 | 549 | err = 1; |
4e44b685 | 550 | magic = path.dentry->d_inode->i_sb->s_magic; |
8d7b48e0 IK |
551 | } |
552 | } else { | |
4e44b685 | 553 | dev_t dev = sbi->sb->s_dev; |
8d7b48e0 | 554 | |
4e44b685 | 555 | err = find_autofs_mount(name, &path, test_by_dev, &dev); |
8d7b48e0 IK |
556 | if (err) |
557 | goto out; | |
558 | ||
4e44b685 | 559 | devid = new_encode_dev(dev); |
8d7b48e0 | 560 | |
4e44b685 | 561 | err = have_submounts(path.dentry); |
8d7b48e0 | 562 | |
4e44b685 | 563 | if (path.mnt->mnt_mountpoint != path.mnt->mnt_root) { |
9393bd07 | 564 | if (follow_down(&path)) |
4e44b685 | 565 | magic = path.mnt->mnt_sb->s_magic; |
8d7b48e0 IK |
566 | } |
567 | } | |
568 | ||
730c9eec IK |
569 | param->ismountpoint.out.devid = devid; |
570 | param->ismountpoint.out.magic = magic; | |
4e44b685 | 571 | path_put(&path); |
8d7b48e0 IK |
572 | out: |
573 | return err; | |
574 | } | |
575 | ||
576 | /* | |
577 | * Our range of ioctl numbers isn't 0 based so we need to shift | |
578 | * the array index by _IOC_NR(AUTOFS_CTL_IOC_FIRST) for the table | |
579 | * lookup. | |
580 | */ | |
581 | #define cmd_idx(cmd) (cmd - _IOC_NR(AUTOFS_DEV_IOCTL_IOC_FIRST)) | |
582 | ||
583 | static ioctl_fn lookup_dev_ioctl(unsigned int cmd) | |
584 | { | |
585 | static struct { | |
586 | int cmd; | |
587 | ioctl_fn fn; | |
588 | } _ioctls[] = { | |
589 | {cmd_idx(AUTOFS_DEV_IOCTL_VERSION_CMD), NULL}, | |
590 | {cmd_idx(AUTOFS_DEV_IOCTL_PROTOVER_CMD), | |
591 | autofs_dev_ioctl_protover}, | |
592 | {cmd_idx(AUTOFS_DEV_IOCTL_PROTOSUBVER_CMD), | |
593 | autofs_dev_ioctl_protosubver}, | |
594 | {cmd_idx(AUTOFS_DEV_IOCTL_OPENMOUNT_CMD), | |
595 | autofs_dev_ioctl_openmount}, | |
596 | {cmd_idx(AUTOFS_DEV_IOCTL_CLOSEMOUNT_CMD), | |
597 | autofs_dev_ioctl_closemount}, | |
598 | {cmd_idx(AUTOFS_DEV_IOCTL_READY_CMD), | |
599 | autofs_dev_ioctl_ready}, | |
600 | {cmd_idx(AUTOFS_DEV_IOCTL_FAIL_CMD), | |
601 | autofs_dev_ioctl_fail}, | |
602 | {cmd_idx(AUTOFS_DEV_IOCTL_SETPIPEFD_CMD), | |
603 | autofs_dev_ioctl_setpipefd}, | |
604 | {cmd_idx(AUTOFS_DEV_IOCTL_CATATONIC_CMD), | |
605 | autofs_dev_ioctl_catatonic}, | |
606 | {cmd_idx(AUTOFS_DEV_IOCTL_TIMEOUT_CMD), | |
607 | autofs_dev_ioctl_timeout}, | |
608 | {cmd_idx(AUTOFS_DEV_IOCTL_REQUESTER_CMD), | |
609 | autofs_dev_ioctl_requester}, | |
610 | {cmd_idx(AUTOFS_DEV_IOCTL_EXPIRE_CMD), | |
611 | autofs_dev_ioctl_expire}, | |
612 | {cmd_idx(AUTOFS_DEV_IOCTL_ASKUMOUNT_CMD), | |
613 | autofs_dev_ioctl_askumount}, | |
614 | {cmd_idx(AUTOFS_DEV_IOCTL_ISMOUNTPOINT_CMD), | |
615 | autofs_dev_ioctl_ismountpoint} | |
616 | }; | |
617 | unsigned int idx = cmd_idx(cmd); | |
618 | ||
619 | return (idx >= ARRAY_SIZE(_ioctls)) ? NULL : _ioctls[idx].fn; | |
620 | } | |
621 | ||
622 | /* ioctl dispatcher */ | |
623 | static int _autofs_dev_ioctl(unsigned int command, struct autofs_dev_ioctl __user *user) | |
624 | { | |
625 | struct autofs_dev_ioctl *param; | |
626 | struct file *fp; | |
627 | struct autofs_sb_info *sbi; | |
628 | unsigned int cmd_first, cmd; | |
629 | ioctl_fn fn = NULL; | |
630 | int err = 0; | |
631 | ||
632 | /* only root can play with this */ | |
633 | if (!capable(CAP_SYS_ADMIN)) | |
634 | return -EPERM; | |
635 | ||
636 | cmd_first = _IOC_NR(AUTOFS_DEV_IOCTL_IOC_FIRST); | |
637 | cmd = _IOC_NR(command); | |
638 | ||
639 | if (_IOC_TYPE(command) != _IOC_TYPE(AUTOFS_DEV_IOCTL_IOC_FIRST) || | |
640 | cmd - cmd_first >= AUTOFS_DEV_IOCTL_IOC_COUNT) { | |
641 | return -ENOTTY; | |
642 | } | |
643 | ||
644 | /* Copy the parameters into kernel space. */ | |
645 | param = copy_dev_ioctl(user); | |
646 | if (IS_ERR(param)) | |
647 | return PTR_ERR(param); | |
648 | ||
649 | err = validate_dev_ioctl(command, param); | |
650 | if (err) | |
651 | goto out; | |
652 | ||
653 | /* The validate routine above always sets the version */ | |
654 | if (cmd == AUTOFS_DEV_IOCTL_VERSION_CMD) | |
655 | goto done; | |
656 | ||
657 | fn = lookup_dev_ioctl(cmd); | |
658 | if (!fn) { | |
659 | AUTOFS_WARN("unknown command 0x%08x", command); | |
660 | return -ENOTTY; | |
661 | } | |
662 | ||
663 | fp = NULL; | |
664 | sbi = NULL; | |
665 | ||
666 | /* | |
667 | * For obvious reasons the openmount can't have a file | |
668 | * descriptor yet. We don't take a reference to the | |
669 | * file during close to allow for immediate release. | |
670 | */ | |
671 | if (cmd != AUTOFS_DEV_IOCTL_OPENMOUNT_CMD && | |
672 | cmd != AUTOFS_DEV_IOCTL_CLOSEMOUNT_CMD) { | |
673 | fp = fget(param->ioctlfd); | |
674 | if (!fp) { | |
675 | if (cmd == AUTOFS_DEV_IOCTL_ISMOUNTPOINT_CMD) | |
676 | goto cont; | |
677 | err = -EBADF; | |
678 | goto out; | |
679 | } | |
680 | ||
681 | if (!fp->f_op) { | |
682 | err = -ENOTTY; | |
683 | fput(fp); | |
684 | goto out; | |
685 | } | |
686 | ||
687 | sbi = autofs_dev_ioctl_sbi(fp); | |
688 | if (!sbi || sbi->magic != AUTOFS_SBI_MAGIC) { | |
689 | err = -EINVAL; | |
690 | fput(fp); | |
691 | goto out; | |
692 | } | |
693 | ||
694 | /* | |
695 | * Admin needs to be able to set the mount catatonic in | |
696 | * order to be able to perform the re-open. | |
697 | */ | |
698 | if (!autofs4_oz_mode(sbi) && | |
699 | cmd != AUTOFS_DEV_IOCTL_CATATONIC_CMD) { | |
700 | err = -EACCES; | |
701 | fput(fp); | |
702 | goto out; | |
703 | } | |
704 | } | |
705 | cont: | |
706 | err = fn(fp, sbi, param); | |
707 | ||
708 | if (fp) | |
709 | fput(fp); | |
710 | done: | |
711 | if (err >= 0 && copy_to_user(user, param, AUTOFS_DEV_IOCTL_SIZE)) | |
712 | err = -EFAULT; | |
713 | out: | |
714 | free_dev_ioctl(param); | |
715 | return err; | |
716 | } | |
717 | ||
718 | static long autofs_dev_ioctl(struct file *file, uint command, ulong u) | |
719 | { | |
720 | int err; | |
721 | err = _autofs_dev_ioctl(command, (struct autofs_dev_ioctl __user *) u); | |
722 | return (long) err; | |
723 | } | |
724 | ||
725 | #ifdef CONFIG_COMPAT | |
726 | static long autofs_dev_ioctl_compat(struct file *file, uint command, ulong u) | |
727 | { | |
728 | return (long) autofs_dev_ioctl(file, command, (ulong) compat_ptr(u)); | |
729 | } | |
730 | #else | |
731 | #define autofs_dev_ioctl_compat NULL | |
732 | #endif | |
733 | ||
734 | static const struct file_operations _dev_ioctl_fops = { | |
735 | .unlocked_ioctl = autofs_dev_ioctl, | |
736 | .compat_ioctl = autofs_dev_ioctl_compat, | |
737 | .owner = THIS_MODULE, | |
738 | }; | |
739 | ||
740 | static struct miscdevice _autofs_dev_ioctl_misc = { | |
741 | .minor = MISC_DYNAMIC_MINOR, | |
742 | .name = AUTOFS_DEVICE_NAME, | |
743 | .fops = &_dev_ioctl_fops | |
744 | }; | |
745 | ||
746 | /* Register/deregister misc character device */ | |
747 | int autofs_dev_ioctl_init(void) | |
748 | { | |
749 | int r; | |
750 | ||
751 | r = misc_register(&_autofs_dev_ioctl_misc); | |
752 | if (r) { | |
753 | AUTOFS_ERROR("misc_register failed for control device"); | |
754 | return r; | |
755 | } | |
756 | ||
757 | return 0; | |
758 | } | |
759 | ||
760 | void autofs_dev_ioctl_exit(void) | |
761 | { | |
762 | misc_deregister(&_autofs_dev_ioctl_misc); | |
763 | return; | |
764 | } | |
765 |