Commit | Line | Data |
---|---|---|
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> | |
5a0e3ad6 | 25 | #include <linux/slab.h> |
8d7b48e0 IK |
26 | |
27 | #include "autofs_i.h" | |
28 | ||
29 | /* | |
30 | * This module implements an interface for routing autofs ioctl control | |
31 | * commands via a miscellaneous device file. | |
32 | * | |
33 | * The alternate interface is needed because we need to be able open | |
34 | * an ioctl file descriptor on an autofs mount that may be covered by | |
35 | * another mount. This situation arises when starting automount(8) | |
36 | * or other user space daemon which uses direct mounts or offset | |
37 | * mounts (used for autofs lazy mount/umount of nested mount trees), | |
38 | * which have been left busy at at service shutdown. | |
39 | */ | |
40 | ||
41 | #define AUTOFS_DEV_IOCTL_SIZE sizeof(struct autofs_dev_ioctl) | |
42 | ||
43 | typedef int (*ioctl_fn)(struct file *, struct autofs_sb_info *, | |
44 | struct autofs_dev_ioctl *); | |
45 | ||
46 | static int check_name(const char *name) | |
47 | { | |
48 | if (!strchr(name, '/')) | |
49 | return -EINVAL; | |
50 | return 0; | |
51 | } | |
52 | ||
53 | /* | |
54 | * Check a string doesn't overrun the chunk of | |
55 | * memory we copied from user land. | |
56 | */ | |
3eac8778 | 57 | static int invalid_str(char *str, size_t size) |
8d7b48e0 | 58 | { |
3eac8778 AV |
59 | if (memchr(str, 0, size)) |
60 | return 0; | |
8d7b48e0 IK |
61 | return -EINVAL; |
62 | } | |
63 | ||
64 | /* | |
65 | * Check that the user compiled against correct version of autofs | |
66 | * misc device code. | |
67 | * | |
68 | * As well as checking the version compatibility this always copies | |
69 | * the kernel interface version out. | |
70 | */ | |
71 | static int check_dev_ioctl_version(int cmd, struct autofs_dev_ioctl *param) | |
72 | { | |
73 | int err = 0; | |
74 | ||
75 | if ((AUTOFS_DEV_IOCTL_VERSION_MAJOR != param->ver_major) || | |
76 | (AUTOFS_DEV_IOCTL_VERSION_MINOR < param->ver_minor)) { | |
77 | AUTOFS_WARN("ioctl control interface version mismatch: " | |
78 | "kernel(%u.%u), user(%u.%u), cmd(%d)", | |
79 | AUTOFS_DEV_IOCTL_VERSION_MAJOR, | |
80 | AUTOFS_DEV_IOCTL_VERSION_MINOR, | |
81 | param->ver_major, param->ver_minor, cmd); | |
82 | err = -EINVAL; | |
83 | } | |
84 | ||
85 | /* Fill in the kernel version. */ | |
86 | param->ver_major = AUTOFS_DEV_IOCTL_VERSION_MAJOR; | |
87 | param->ver_minor = AUTOFS_DEV_IOCTL_VERSION_MINOR; | |
88 | ||
89 | return err; | |
90 | } | |
91 | ||
92 | /* | |
93 | * Copy parameter control struct, including a possible path allocated | |
94 | * at the end of the struct. | |
95 | */ | |
96 | static struct autofs_dev_ioctl *copy_dev_ioctl(struct autofs_dev_ioctl __user *in) | |
97 | { | |
0a280962 | 98 | struct autofs_dev_ioctl tmp, *res; |
8d7b48e0 IK |
99 | |
100 | if (copy_from_user(&tmp, in, sizeof(tmp))) | |
101 | return ERR_PTR(-EFAULT); | |
102 | ||
103 | if (tmp.size < sizeof(tmp)) | |
104 | return ERR_PTR(-EINVAL); | |
105 | ||
e53d77eb SL |
106 | if (tmp.size > (PATH_MAX + sizeof(tmp))) |
107 | return ERR_PTR(-ENAMETOOLONG); | |
108 | ||
0a280962 AV |
109 | res = memdup_user(in, tmp.size); |
110 | if (!IS_ERR(res)) | |
111 | res->size = tmp.size; | |
112 | ||
113 | return res; | |
8d7b48e0 IK |
114 | } |
115 | ||
116 | static inline void free_dev_ioctl(struct autofs_dev_ioctl *param) | |
117 | { | |
118 | kfree(param); | |
119 | return; | |
120 | } | |
121 | ||
122 | /* | |
123 | * Check sanity of parameter control fields and if a path is present | |
bae8ec66 | 124 | * check that it is terminated and contains at least one "/". |
8d7b48e0 IK |
125 | */ |
126 | static int validate_dev_ioctl(int cmd, struct autofs_dev_ioctl *param) | |
127 | { | |
96b03179 | 128 | int err; |
8d7b48e0 | 129 | |
96b03179 IK |
130 | err = check_dev_ioctl_version(cmd, param); |
131 | if (err) { | |
8d7b48e0 IK |
132 | AUTOFS_WARN("invalid device control module version " |
133 | "supplied for cmd(0x%08x)", cmd); | |
134 | goto out; | |
135 | } | |
136 | ||
137 | if (param->size > sizeof(*param)) { | |
3eac8778 | 138 | err = invalid_str(param->path, param->size - sizeof(*param)); |
8d7b48e0 | 139 | if (err) { |
bae8ec66 IK |
140 | AUTOFS_WARN( |
141 | "path string terminator missing for cmd(0x%08x)", | |
142 | cmd); | |
8d7b48e0 IK |
143 | goto out; |
144 | } | |
145 | ||
bae8ec66 | 146 | err = check_name(param->path); |
8d7b48e0 IK |
147 | if (err) { |
148 | AUTOFS_WARN("invalid path supplied for cmd(0x%08x)", | |
149 | cmd); | |
150 | goto out; | |
151 | } | |
152 | } | |
153 | ||
154 | err = 0; | |
155 | out: | |
156 | return err; | |
157 | } | |
158 | ||
159 | /* | |
160 | * Get the autofs super block info struct from the file opened on | |
161 | * the autofs mount point. | |
162 | */ | |
163 | static struct autofs_sb_info *autofs_dev_ioctl_sbi(struct file *f) | |
164 | { | |
165 | struct autofs_sb_info *sbi = NULL; | |
166 | struct inode *inode; | |
167 | ||
168 | if (f) { | |
496ad9aa | 169 | inode = file_inode(f); |
8d7b48e0 IK |
170 | sbi = autofs4_sbi(inode->i_sb); |
171 | } | |
172 | return sbi; | |
173 | } | |
174 | ||
175 | /* Return autofs module protocol version */ | |
176 | static int autofs_dev_ioctl_protover(struct file *fp, | |
177 | struct autofs_sb_info *sbi, | |
178 | struct autofs_dev_ioctl *param) | |
179 | { | |
730c9eec | 180 | param->protover.version = sbi->version; |
8d7b48e0 IK |
181 | return 0; |
182 | } | |
183 | ||
184 | /* Return autofs module protocol sub version */ | |
185 | static int autofs_dev_ioctl_protosubver(struct file *fp, | |
186 | struct autofs_sb_info *sbi, | |
187 | struct autofs_dev_ioctl *param) | |
188 | { | |
730c9eec | 189 | param->protosubver.sub_version = sbi->sub_version; |
8d7b48e0 IK |
190 | return 0; |
191 | } | |
192 | ||
ac838719 | 193 | /* Find the topmost mount satisfying test() */ |
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 | 199 | struct path path; |
ac838719 | 200 | int err = kern_path_mountpoint(AT_FDCWD, pathname, &path, 0); |
4e44b685 AV |
201 | if (err) |
202 | return err; | |
8d7b48e0 | 203 | err = -ENOENT; |
4e44b685 | 204 | while (path.dentry == path.mnt->mnt_root) { |
d8c9584e | 205 | if (path.dentry->d_sb->s_magic == AUTOFS_SUPER_MAGIC) { |
4e44b685 AV |
206 | if (test(&path, data)) { |
207 | path_get(&path); | |
4e44b685 | 208 | *res = path; |
8d7b48e0 | 209 | err = 0; |
ac838719 | 210 | break; |
8d7b48e0 IK |
211 | } |
212 | } | |
bab77ebf | 213 | if (!follow_up(&path)) |
4e44b685 | 214 | break; |
8d7b48e0 | 215 | } |
4e44b685 | 216 | path_put(&path); |
8d7b48e0 IK |
217 | return err; |
218 | } | |
219 | ||
4e44b685 | 220 | static int test_by_dev(struct path *path, void *p) |
8d7b48e0 | 221 | { |
d8c9584e | 222 | return path->dentry->d_sb->s_dev == *(dev_t *)p; |
4e44b685 | 223 | } |
8d7b48e0 | 224 | |
4e44b685 AV |
225 | static int test_by_type(struct path *path, void *p) |
226 | { | |
227 | struct autofs_info *ino = autofs4_dentry_ino(path->dentry); | |
228 | return ino && ino->sbi->type & *(unsigned *)p; | |
8d7b48e0 IK |
229 | } |
230 | ||
8d7b48e0 IK |
231 | /* |
232 | * Open a file descriptor on the autofs mount point corresponding | |
233 | * to the given path and device number (aka. new_encode_dev(sb->s_dev)). | |
234 | */ | |
4e44b685 | 235 | static int autofs_dev_ioctl_open_mountpoint(const char *name, dev_t devid) |
8d7b48e0 | 236 | { |
8d7b48e0 IK |
237 | int err, fd; |
238 | ||
c921b40d | 239 | fd = get_unused_fd_flags(O_CLOEXEC); |
8d7b48e0 | 240 | if (likely(fd >= 0)) { |
4e44b685 AV |
241 | struct file *filp; |
242 | struct path path; | |
243 | ||
244 | err = find_autofs_mount(name, &path, test_by_dev, &devid); | |
8d7b48e0 IK |
245 | if (err) |
246 | goto out; | |
247 | ||
248 | /* | |
4e44b685 | 249 | * Find autofs super block that has the device number |
8d7b48e0 IK |
250 | * corresponding to the autofs fs we want to open. |
251 | */ | |
8d7b48e0 | 252 | |
765927b2 AV |
253 | filp = dentry_open(&path, O_RDONLY, current_cred()); |
254 | path_put(&path); | |
8d7b48e0 IK |
255 | if (IS_ERR(filp)) { |
256 | err = PTR_ERR(filp); | |
257 | goto out; | |
258 | } | |
259 | ||
c921b40d | 260 | fd_install(fd, filp); |
8d7b48e0 IK |
261 | } |
262 | ||
263 | return fd; | |
264 | ||
265 | out: | |
266 | put_unused_fd(fd); | |
267 | return err; | |
268 | } | |
269 | ||
270 | /* Open a file descriptor on an autofs mount point */ | |
271 | static int autofs_dev_ioctl_openmount(struct file *fp, | |
272 | struct autofs_sb_info *sbi, | |
273 | struct autofs_dev_ioctl *param) | |
274 | { | |
275 | const char *path; | |
276 | dev_t devid; | |
277 | int err, fd; | |
278 | ||
279 | /* param->path has already been checked */ | |
730c9eec | 280 | if (!param->openmount.devid) |
8d7b48e0 IK |
281 | return -EINVAL; |
282 | ||
283 | param->ioctlfd = -1; | |
284 | ||
285 | path = param->path; | |
4e44b685 | 286 | devid = new_decode_dev(param->openmount.devid); |
8d7b48e0 IK |
287 | |
288 | err = 0; | |
289 | fd = autofs_dev_ioctl_open_mountpoint(path, devid); | |
290 | if (unlikely(fd < 0)) { | |
291 | err = fd; | |
292 | goto out; | |
293 | } | |
294 | ||
295 | param->ioctlfd = fd; | |
296 | out: | |
297 | return err; | |
298 | } | |
299 | ||
300 | /* Close file descriptor allocated above (user can also use close(2)). */ | |
301 | static int autofs_dev_ioctl_closemount(struct file *fp, | |
302 | struct autofs_sb_info *sbi, | |
303 | struct autofs_dev_ioctl *param) | |
304 | { | |
305 | return sys_close(param->ioctlfd); | |
306 | } | |
307 | ||
308 | /* | |
309 | * Send "ready" status for an existing wait (either a mount or an expire | |
310 | * request). | |
311 | */ | |
312 | static int autofs_dev_ioctl_ready(struct file *fp, | |
313 | struct autofs_sb_info *sbi, | |
314 | struct autofs_dev_ioctl *param) | |
315 | { | |
316 | autofs_wqt_t token; | |
317 | ||
730c9eec | 318 | token = (autofs_wqt_t) param->ready.token; |
8d7b48e0 IK |
319 | return autofs4_wait_release(sbi, token, 0); |
320 | } | |
321 | ||
322 | /* | |
323 | * Send "fail" status for an existing wait (either a mount or an expire | |
324 | * request). | |
325 | */ | |
326 | static int autofs_dev_ioctl_fail(struct file *fp, | |
327 | struct autofs_sb_info *sbi, | |
328 | struct autofs_dev_ioctl *param) | |
329 | { | |
330 | autofs_wqt_t token; | |
331 | int status; | |
332 | ||
730c9eec IK |
333 | token = (autofs_wqt_t) param->fail.token; |
334 | status = param->fail.status ? param->fail.status : -ENOENT; | |
8d7b48e0 IK |
335 | return autofs4_wait_release(sbi, token, status); |
336 | } | |
337 | ||
338 | /* | |
339 | * Set the pipe fd for kernel communication to the daemon. | |
340 | * | |
341 | * Normally this is set at mount using an option but if we | |
342 | * are reconnecting to a busy mount then we need to use this | |
343 | * to tell the autofs mount about the new kernel pipe fd. In | |
344 | * order to protect mounts against incorrectly setting the | |
345 | * pipefd we also require that the autofs mount be catatonic. | |
346 | * | |
347 | * This also sets the process group id used to identify the | |
348 | * controlling process (eg. the owning automount(8) daemon). | |
349 | */ | |
350 | static int autofs_dev_ioctl_setpipefd(struct file *fp, | |
351 | struct autofs_sb_info *sbi, | |
352 | struct autofs_dev_ioctl *param) | |
353 | { | |
354 | int pipefd; | |
355 | int err = 0; | |
6eaba35b | 356 | struct pid *new_pid = NULL; |
8d7b48e0 | 357 | |
730c9eec | 358 | if (param->setpipefd.pipefd == -1) |
8d7b48e0 IK |
359 | return -EINVAL; |
360 | ||
730c9eec | 361 | pipefd = param->setpipefd.pipefd; |
8d7b48e0 IK |
362 | |
363 | mutex_lock(&sbi->wq_mutex); | |
364 | if (!sbi->catatonic) { | |
365 | mutex_unlock(&sbi->wq_mutex); | |
366 | return -EBUSY; | |
367 | } else { | |
6eaba35b SB |
368 | struct file *pipe; |
369 | ||
370 | new_pid = get_task_pid(current, PIDTYPE_PGID); | |
371 | ||
372 | if (ns_of_pid(new_pid) != ns_of_pid(sbi->oz_pgrp)) { | |
373 | AUTOFS_WARN("Not allowed to change PID namespace"); | |
374 | err = -EINVAL; | |
375 | goto out; | |
376 | } | |
377 | ||
378 | pipe = fget(pipefd); | |
3dc8fe4d JJ |
379 | if (!pipe) { |
380 | err = -EBADF; | |
381 | goto out; | |
382 | } | |
64f371bc | 383 | if (autofs_prepare_pipe(pipe) < 0) { |
8d7b48e0 IK |
384 | err = -EPIPE; |
385 | fput(pipe); | |
386 | goto out; | |
387 | } | |
6eaba35b | 388 | swap(sbi->oz_pgrp, new_pid); |
8d7b48e0 IK |
389 | sbi->pipefd = pipefd; |
390 | sbi->pipe = pipe; | |
391 | sbi->catatonic = 0; | |
392 | } | |
393 | out: | |
6eaba35b | 394 | put_pid(new_pid); |
8d7b48e0 IK |
395 | mutex_unlock(&sbi->wq_mutex); |
396 | return err; | |
397 | } | |
398 | ||
399 | /* | |
400 | * Make the autofs mount point catatonic, no longer responsive to | |
401 | * mount requests. Also closes the kernel pipe file descriptor. | |
402 | */ | |
403 | static int autofs_dev_ioctl_catatonic(struct file *fp, | |
404 | struct autofs_sb_info *sbi, | |
405 | struct autofs_dev_ioctl *param) | |
406 | { | |
407 | autofs4_catatonic_mode(sbi); | |
408 | return 0; | |
409 | } | |
410 | ||
411 | /* Set the autofs mount timeout */ | |
412 | static int autofs_dev_ioctl_timeout(struct file *fp, | |
413 | struct autofs_sb_info *sbi, | |
414 | struct autofs_dev_ioctl *param) | |
415 | { | |
416 | unsigned long timeout; | |
417 | ||
730c9eec IK |
418 | timeout = param->timeout.timeout; |
419 | param->timeout.timeout = sbi->exp_timeout / HZ; | |
8d7b48e0 IK |
420 | sbi->exp_timeout = timeout * HZ; |
421 | return 0; | |
422 | } | |
423 | ||
424 | /* | |
425 | * Return the uid and gid of the last request for the mount | |
426 | * | |
427 | * When reconstructing an autofs mount tree with active mounts | |
428 | * we need to re-connect to mounts that may have used the original | |
429 | * process uid and gid (or string variations of them) for mount | |
430 | * lookups within the map entry. | |
431 | */ | |
432 | static int autofs_dev_ioctl_requester(struct file *fp, | |
433 | struct autofs_sb_info *sbi, | |
434 | struct autofs_dev_ioctl *param) | |
435 | { | |
436 | struct autofs_info *ino; | |
4e44b685 | 437 | struct path path; |
8d7b48e0 IK |
438 | dev_t devid; |
439 | int err = -ENOENT; | |
440 | ||
441 | if (param->size <= sizeof(*param)) { | |
442 | err = -EINVAL; | |
443 | goto out; | |
444 | } | |
445 | ||
4e44b685 | 446 | devid = sbi->sb->s_dev; |
8d7b48e0 | 447 | |
730c9eec | 448 | param->requester.uid = param->requester.gid = -1; |
8d7b48e0 | 449 | |
4e44b685 | 450 | err = find_autofs_mount(param->path, &path, test_by_dev, &devid); |
8d7b48e0 IK |
451 | if (err) |
452 | goto out; | |
453 | ||
4e44b685 | 454 | ino = autofs4_dentry_ino(path.dentry); |
8d7b48e0 IK |
455 | if (ino) { |
456 | err = 0; | |
23bfc2a2 | 457 | autofs4_expire_wait(path.dentry, 0); |
8d7b48e0 | 458 | spin_lock(&sbi->fs_lock); |
45634cd8 EB |
459 | param->requester.uid = from_kuid_munged(current_user_ns(), ino->uid); |
460 | param->requester.gid = from_kgid_munged(current_user_ns(), ino->gid); | |
8d7b48e0 IK |
461 | spin_unlock(&sbi->fs_lock); |
462 | } | |
4e44b685 | 463 | path_put(&path); |
8d7b48e0 IK |
464 | out: |
465 | return err; | |
466 | } | |
467 | ||
468 | /* | |
469 | * Call repeatedly until it returns -EAGAIN, meaning there's nothing | |
470 | * more that can be done. | |
471 | */ | |
472 | static int autofs_dev_ioctl_expire(struct file *fp, | |
473 | struct autofs_sb_info *sbi, | |
474 | struct autofs_dev_ioctl *param) | |
475 | { | |
8d7b48e0 | 476 | struct vfsmount *mnt; |
8d7b48e0 IK |
477 | int how; |
478 | ||
730c9eec | 479 | how = param->expire.how; |
8d7b48e0 IK |
480 | mnt = fp->f_path.mnt; |
481 | ||
56fcef75 | 482 | return autofs4_do_expire_multi(sbi->sb, mnt, sbi, how); |
8d7b48e0 IK |
483 | } |
484 | ||
485 | /* Check if autofs mount point is in use */ | |
486 | static int autofs_dev_ioctl_askumount(struct file *fp, | |
487 | struct autofs_sb_info *sbi, | |
488 | struct autofs_dev_ioctl *param) | |
489 | { | |
730c9eec | 490 | param->askumount.may_umount = 0; |
8d7b48e0 | 491 | if (may_umount(fp->f_path.mnt)) |
730c9eec | 492 | param->askumount.may_umount = 1; |
8d7b48e0 IK |
493 | return 0; |
494 | } | |
495 | ||
496 | /* | |
497 | * Check if the given path is a mountpoint. | |
498 | * | |
499 | * If we are supplied with the file descriptor of an autofs | |
500 | * mount we're looking for a specific mount. In this case | |
501 | * the path is considered a mountpoint if it is itself a | |
502 | * mountpoint or contains a mount, such as a multi-mount | |
503 | * without a root mount. In this case we return 1 if the | |
504 | * path is a mount point and the super magic of the covering | |
505 | * mount if there is one or 0 if it isn't a mountpoint. | |
506 | * | |
507 | * If we aren't supplied with a file descriptor then we | |
ac838719 IK |
508 | * lookup the path and check if it is the root of a mount. |
509 | * If a type is given we are looking for a particular autofs | |
510 | * mount and if we don't find a match we return fail. If the | |
511 | * located path is the root of a mount we return 1 along with | |
512 | * the super magic of the mount or 0 otherwise. | |
8d7b48e0 IK |
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 | 539 | if (autofs_type_any(type)) |
ac838719 IK |
540 | err = kern_path_mountpoint(AT_FDCWD, |
541 | name, &path, LOOKUP_FOLLOW); | |
4e44b685 | 542 | else |
ac838719 IK |
543 | err = find_autofs_mount(name, &path, |
544 | test_by_type, &type); | |
4e44b685 AV |
545 | if (err) |
546 | goto out; | |
d8c9584e | 547 | devid = new_encode_dev(path.dentry->d_sb->s_dev); |
8d7b48e0 | 548 | err = 0; |
f598f9f1 | 549 | if (path.mnt->mnt_root == path.dentry) { |
8d7b48e0 | 550 | err = 1; |
d8c9584e | 551 | magic = path.dentry->d_sb->s_magic; |
8d7b48e0 IK |
552 | } |
553 | } else { | |
4e44b685 | 554 | dev_t dev = sbi->sb->s_dev; |
8d7b48e0 | 555 | |
4e44b685 | 556 | err = find_autofs_mount(name, &path, test_by_dev, &dev); |
8d7b48e0 IK |
557 | if (err) |
558 | goto out; | |
559 | ||
4e44b685 | 560 | devid = new_encode_dev(dev); |
8d7b48e0 | 561 | |
4e44b685 | 562 | err = have_submounts(path.dentry); |
8d7b48e0 | 563 | |
cc53ce53 | 564 | if (follow_down_one(&path)) |
d8c9584e | 565 | magic = path.dentry->d_sb->s_magic; |
8d7b48e0 IK |
566 | } |
567 | ||
730c9eec IK |
568 | param->ismountpoint.out.devid = devid; |
569 | param->ismountpoint.out.magic = magic; | |
4e44b685 | 570 | path_put(&path); |
8d7b48e0 IK |
571 | out: |
572 | return err; | |
573 | } | |
574 | ||
575 | /* | |
576 | * Our range of ioctl numbers isn't 0 based so we need to shift | |
577 | * the array index by _IOC_NR(AUTOFS_CTL_IOC_FIRST) for the table | |
578 | * lookup. | |
579 | */ | |
580 | #define cmd_idx(cmd) (cmd - _IOC_NR(AUTOFS_DEV_IOCTL_IOC_FIRST)) | |
581 | ||
582 | static ioctl_fn lookup_dev_ioctl(unsigned int cmd) | |
583 | { | |
584 | static struct { | |
585 | int cmd; | |
586 | ioctl_fn fn; | |
587 | } _ioctls[] = { | |
588 | {cmd_idx(AUTOFS_DEV_IOCTL_VERSION_CMD), NULL}, | |
589 | {cmd_idx(AUTOFS_DEV_IOCTL_PROTOVER_CMD), | |
590 | autofs_dev_ioctl_protover}, | |
591 | {cmd_idx(AUTOFS_DEV_IOCTL_PROTOSUBVER_CMD), | |
592 | autofs_dev_ioctl_protosubver}, | |
593 | {cmd_idx(AUTOFS_DEV_IOCTL_OPENMOUNT_CMD), | |
594 | autofs_dev_ioctl_openmount}, | |
595 | {cmd_idx(AUTOFS_DEV_IOCTL_CLOSEMOUNT_CMD), | |
596 | autofs_dev_ioctl_closemount}, | |
597 | {cmd_idx(AUTOFS_DEV_IOCTL_READY_CMD), | |
598 | autofs_dev_ioctl_ready}, | |
599 | {cmd_idx(AUTOFS_DEV_IOCTL_FAIL_CMD), | |
600 | autofs_dev_ioctl_fail}, | |
601 | {cmd_idx(AUTOFS_DEV_IOCTL_SETPIPEFD_CMD), | |
602 | autofs_dev_ioctl_setpipefd}, | |
603 | {cmd_idx(AUTOFS_DEV_IOCTL_CATATONIC_CMD), | |
604 | autofs_dev_ioctl_catatonic}, | |
605 | {cmd_idx(AUTOFS_DEV_IOCTL_TIMEOUT_CMD), | |
606 | autofs_dev_ioctl_timeout}, | |
607 | {cmd_idx(AUTOFS_DEV_IOCTL_REQUESTER_CMD), | |
608 | autofs_dev_ioctl_requester}, | |
609 | {cmd_idx(AUTOFS_DEV_IOCTL_EXPIRE_CMD), | |
610 | autofs_dev_ioctl_expire}, | |
611 | {cmd_idx(AUTOFS_DEV_IOCTL_ASKUMOUNT_CMD), | |
612 | autofs_dev_ioctl_askumount}, | |
613 | {cmd_idx(AUTOFS_DEV_IOCTL_ISMOUNTPOINT_CMD), | |
614 | autofs_dev_ioctl_ismountpoint} | |
615 | }; | |
616 | unsigned int idx = cmd_idx(cmd); | |
617 | ||
618 | return (idx >= ARRAY_SIZE(_ioctls)) ? NULL : _ioctls[idx].fn; | |
619 | } | |
620 | ||
621 | /* ioctl dispatcher */ | |
622 | static int _autofs_dev_ioctl(unsigned int command, struct autofs_dev_ioctl __user *user) | |
623 | { | |
624 | struct autofs_dev_ioctl *param; | |
625 | struct file *fp; | |
626 | struct autofs_sb_info *sbi; | |
627 | unsigned int cmd_first, cmd; | |
628 | ioctl_fn fn = NULL; | |
629 | int err = 0; | |
630 | ||
631 | /* only root can play with this */ | |
632 | if (!capable(CAP_SYS_ADMIN)) | |
633 | return -EPERM; | |
634 | ||
635 | cmd_first = _IOC_NR(AUTOFS_DEV_IOCTL_IOC_FIRST); | |
636 | cmd = _IOC_NR(command); | |
637 | ||
638 | if (_IOC_TYPE(command) != _IOC_TYPE(AUTOFS_DEV_IOCTL_IOC_FIRST) || | |
639 | cmd - cmd_first >= AUTOFS_DEV_IOCTL_IOC_COUNT) { | |
640 | return -ENOTTY; | |
641 | } | |
642 | ||
643 | /* Copy the parameters into kernel space. */ | |
644 | param = copy_dev_ioctl(user); | |
645 | if (IS_ERR(param)) | |
646 | return PTR_ERR(param); | |
647 | ||
648 | err = validate_dev_ioctl(command, param); | |
649 | if (err) | |
650 | goto out; | |
651 | ||
652 | /* The validate routine above always sets the version */ | |
653 | if (cmd == AUTOFS_DEV_IOCTL_VERSION_CMD) | |
654 | goto done; | |
655 | ||
656 | fn = lookup_dev_ioctl(cmd); | |
657 | if (!fn) { | |
658 | AUTOFS_WARN("unknown command 0x%08x", command); | |
659 | return -ENOTTY; | |
660 | } | |
661 | ||
662 | fp = NULL; | |
663 | sbi = NULL; | |
664 | ||
665 | /* | |
666 | * For obvious reasons the openmount can't have a file | |
667 | * descriptor yet. We don't take a reference to the | |
668 | * file during close to allow for immediate release. | |
669 | */ | |
670 | if (cmd != AUTOFS_DEV_IOCTL_OPENMOUNT_CMD && | |
671 | cmd != AUTOFS_DEV_IOCTL_CLOSEMOUNT_CMD) { | |
672 | fp = fget(param->ioctlfd); | |
673 | if (!fp) { | |
674 | if (cmd == AUTOFS_DEV_IOCTL_ISMOUNTPOINT_CMD) | |
675 | goto cont; | |
676 | err = -EBADF; | |
677 | goto out; | |
678 | } | |
679 | ||
8d7b48e0 IK |
680 | sbi = autofs_dev_ioctl_sbi(fp); |
681 | if (!sbi || sbi->magic != AUTOFS_SBI_MAGIC) { | |
682 | err = -EINVAL; | |
683 | fput(fp); | |
684 | goto out; | |
685 | } | |
686 | ||
687 | /* | |
688 | * Admin needs to be able to set the mount catatonic in | |
689 | * order to be able to perform the re-open. | |
690 | */ | |
691 | if (!autofs4_oz_mode(sbi) && | |
692 | cmd != AUTOFS_DEV_IOCTL_CATATONIC_CMD) { | |
693 | err = -EACCES; | |
694 | fput(fp); | |
695 | goto out; | |
696 | } | |
697 | } | |
698 | cont: | |
699 | err = fn(fp, sbi, param); | |
700 | ||
701 | if (fp) | |
702 | fput(fp); | |
703 | done: | |
704 | if (err >= 0 && copy_to_user(user, param, AUTOFS_DEV_IOCTL_SIZE)) | |
705 | err = -EFAULT; | |
706 | out: | |
707 | free_dev_ioctl(param); | |
708 | return err; | |
709 | } | |
710 | ||
711 | static long autofs_dev_ioctl(struct file *file, uint command, ulong u) | |
712 | { | |
713 | int err; | |
714 | err = _autofs_dev_ioctl(command, (struct autofs_dev_ioctl __user *) u); | |
715 | return (long) err; | |
716 | } | |
717 | ||
718 | #ifdef CONFIG_COMPAT | |
719 | static long autofs_dev_ioctl_compat(struct file *file, uint command, ulong u) | |
720 | { | |
721 | return (long) autofs_dev_ioctl(file, command, (ulong) compat_ptr(u)); | |
722 | } | |
723 | #else | |
724 | #define autofs_dev_ioctl_compat NULL | |
725 | #endif | |
726 | ||
727 | static const struct file_operations _dev_ioctl_fops = { | |
728 | .unlocked_ioctl = autofs_dev_ioctl, | |
729 | .compat_ioctl = autofs_dev_ioctl_compat, | |
730 | .owner = THIS_MODULE, | |
6038f373 | 731 | .llseek = noop_llseek, |
8d7b48e0 IK |
732 | }; |
733 | ||
734 | static struct miscdevice _autofs_dev_ioctl_misc = { | |
578454ff | 735 | .minor = AUTOFS_MINOR, |
8d7b48e0 IK |
736 | .name = AUTOFS_DEVICE_NAME, |
737 | .fops = &_dev_ioctl_fops | |
738 | }; | |
739 | ||
578454ff KS |
740 | MODULE_ALIAS_MISCDEV(AUTOFS_MINOR); |
741 | MODULE_ALIAS("devname:autofs"); | |
742 | ||
8d7b48e0 | 743 | /* Register/deregister misc character device */ |
3ff6db32 | 744 | int __init autofs_dev_ioctl_init(void) |
8d7b48e0 IK |
745 | { |
746 | int r; | |
747 | ||
748 | r = misc_register(&_autofs_dev_ioctl_misc); | |
749 | if (r) { | |
750 | AUTOFS_ERROR("misc_register failed for control device"); | |
751 | return r; | |
752 | } | |
753 | ||
754 | return 0; | |
755 | } | |
756 | ||
757 | void autofs_dev_ioctl_exit(void) | |
758 | { | |
759 | misc_deregister(&_autofs_dev_ioctl_misc); | |
760 | return; | |
761 | } | |
762 |