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> | |
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 | { | |
7ca5ca60 | 98 | struct autofs_dev_ioctl tmp; |
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 | ||
7ca5ca60 | 109 | return memdup_user(in, tmp.size); |
8d7b48e0 IK |
110 | } |
111 | ||
112 | static inline void free_dev_ioctl(struct autofs_dev_ioctl *param) | |
113 | { | |
114 | kfree(param); | |
115 | return; | |
116 | } | |
117 | ||
118 | /* | |
119 | * Check sanity of parameter control fields and if a path is present | |
bae8ec66 | 120 | * check that it is terminated and contains at least one "/". |
8d7b48e0 IK |
121 | */ |
122 | static int validate_dev_ioctl(int cmd, struct autofs_dev_ioctl *param) | |
123 | { | |
96b03179 | 124 | int err; |
8d7b48e0 | 125 | |
96b03179 IK |
126 | err = check_dev_ioctl_version(cmd, param); |
127 | if (err) { | |
8d7b48e0 IK |
128 | AUTOFS_WARN("invalid device control module version " |
129 | "supplied for cmd(0x%08x)", cmd); | |
130 | goto out; | |
131 | } | |
132 | ||
133 | if (param->size > sizeof(*param)) { | |
3eac8778 | 134 | err = invalid_str(param->path, param->size - sizeof(*param)); |
8d7b48e0 | 135 | if (err) { |
bae8ec66 IK |
136 | AUTOFS_WARN( |
137 | "path string terminator missing for cmd(0x%08x)", | |
138 | cmd); | |
8d7b48e0 IK |
139 | goto out; |
140 | } | |
141 | ||
bae8ec66 | 142 | err = check_name(param->path); |
8d7b48e0 IK |
143 | if (err) { |
144 | AUTOFS_WARN("invalid path supplied for cmd(0x%08x)", | |
145 | cmd); | |
146 | goto out; | |
147 | } | |
148 | } | |
149 | ||
150 | err = 0; | |
151 | out: | |
152 | return err; | |
153 | } | |
154 | ||
155 | /* | |
156 | * Get the autofs super block info struct from the file opened on | |
157 | * the autofs mount point. | |
158 | */ | |
159 | static struct autofs_sb_info *autofs_dev_ioctl_sbi(struct file *f) | |
160 | { | |
161 | struct autofs_sb_info *sbi = NULL; | |
162 | struct inode *inode; | |
163 | ||
164 | if (f) { | |
496ad9aa | 165 | inode = file_inode(f); |
8d7b48e0 IK |
166 | sbi = autofs4_sbi(inode->i_sb); |
167 | } | |
168 | return sbi; | |
169 | } | |
170 | ||
171 | /* Return autofs module protocol version */ | |
172 | static int autofs_dev_ioctl_protover(struct file *fp, | |
173 | struct autofs_sb_info *sbi, | |
174 | struct autofs_dev_ioctl *param) | |
175 | { | |
730c9eec | 176 | param->protover.version = sbi->version; |
8d7b48e0 IK |
177 | return 0; |
178 | } | |
179 | ||
180 | /* Return autofs module protocol sub version */ | |
181 | static int autofs_dev_ioctl_protosubver(struct file *fp, | |
182 | struct autofs_sb_info *sbi, | |
183 | struct autofs_dev_ioctl *param) | |
184 | { | |
730c9eec | 185 | param->protosubver.sub_version = sbi->sub_version; |
8d7b48e0 IK |
186 | return 0; |
187 | } | |
188 | ||
ac838719 | 189 | /* Find the topmost mount satisfying test() */ |
4e44b685 AV |
190 | static int find_autofs_mount(const char *pathname, |
191 | struct path *res, | |
192 | int test(struct path *path, void *data), | |
193 | void *data) | |
8d7b48e0 | 194 | { |
4e44b685 | 195 | struct path path; |
ac838719 | 196 | int err = kern_path_mountpoint(AT_FDCWD, pathname, &path, 0); |
4e44b685 AV |
197 | if (err) |
198 | return err; | |
8d7b48e0 | 199 | err = -ENOENT; |
4e44b685 | 200 | while (path.dentry == path.mnt->mnt_root) { |
d8c9584e | 201 | if (path.dentry->d_sb->s_magic == AUTOFS_SUPER_MAGIC) { |
4e44b685 AV |
202 | if (test(&path, data)) { |
203 | path_get(&path); | |
4e44b685 | 204 | *res = path; |
8d7b48e0 | 205 | err = 0; |
ac838719 | 206 | break; |
8d7b48e0 IK |
207 | } |
208 | } | |
bab77ebf | 209 | if (!follow_up(&path)) |
4e44b685 | 210 | break; |
8d7b48e0 | 211 | } |
4e44b685 | 212 | path_put(&path); |
8d7b48e0 IK |
213 | return err; |
214 | } | |
215 | ||
4e44b685 | 216 | static int test_by_dev(struct path *path, void *p) |
8d7b48e0 | 217 | { |
d8c9584e | 218 | return path->dentry->d_sb->s_dev == *(dev_t *)p; |
4e44b685 | 219 | } |
8d7b48e0 | 220 | |
4e44b685 AV |
221 | static int test_by_type(struct path *path, void *p) |
222 | { | |
223 | struct autofs_info *ino = autofs4_dentry_ino(path->dentry); | |
224 | return ino && ino->sbi->type & *(unsigned *)p; | |
8d7b48e0 IK |
225 | } |
226 | ||
8d7b48e0 IK |
227 | /* |
228 | * Open a file descriptor on the autofs mount point corresponding | |
229 | * to the given path and device number (aka. new_encode_dev(sb->s_dev)). | |
230 | */ | |
4e44b685 | 231 | static int autofs_dev_ioctl_open_mountpoint(const char *name, dev_t devid) |
8d7b48e0 | 232 | { |
8d7b48e0 IK |
233 | int err, fd; |
234 | ||
c921b40d | 235 | fd = get_unused_fd_flags(O_CLOEXEC); |
8d7b48e0 | 236 | if (likely(fd >= 0)) { |
4e44b685 AV |
237 | struct file *filp; |
238 | struct path path; | |
239 | ||
240 | err = find_autofs_mount(name, &path, test_by_dev, &devid); | |
8d7b48e0 IK |
241 | if (err) |
242 | goto out; | |
243 | ||
244 | /* | |
4e44b685 | 245 | * Find autofs super block that has the device number |
8d7b48e0 IK |
246 | * corresponding to the autofs fs we want to open. |
247 | */ | |
8d7b48e0 | 248 | |
765927b2 AV |
249 | filp = dentry_open(&path, O_RDONLY, current_cred()); |
250 | path_put(&path); | |
8d7b48e0 IK |
251 | if (IS_ERR(filp)) { |
252 | err = PTR_ERR(filp); | |
253 | goto out; | |
254 | } | |
255 | ||
c921b40d | 256 | fd_install(fd, filp); |
8d7b48e0 IK |
257 | } |
258 | ||
259 | return fd; | |
260 | ||
261 | out: | |
262 | put_unused_fd(fd); | |
263 | return err; | |
264 | } | |
265 | ||
266 | /* Open a file descriptor on an autofs mount point */ | |
267 | static int autofs_dev_ioctl_openmount(struct file *fp, | |
268 | struct autofs_sb_info *sbi, | |
269 | struct autofs_dev_ioctl *param) | |
270 | { | |
271 | const char *path; | |
272 | dev_t devid; | |
273 | int err, fd; | |
274 | ||
275 | /* param->path has already been checked */ | |
730c9eec | 276 | if (!param->openmount.devid) |
8d7b48e0 IK |
277 | return -EINVAL; |
278 | ||
279 | param->ioctlfd = -1; | |
280 | ||
281 | path = param->path; | |
4e44b685 | 282 | devid = new_decode_dev(param->openmount.devid); |
8d7b48e0 IK |
283 | |
284 | err = 0; | |
285 | fd = autofs_dev_ioctl_open_mountpoint(path, devid); | |
286 | if (unlikely(fd < 0)) { | |
287 | err = fd; | |
288 | goto out; | |
289 | } | |
290 | ||
291 | param->ioctlfd = fd; | |
292 | out: | |
293 | return err; | |
294 | } | |
295 | ||
296 | /* Close file descriptor allocated above (user can also use close(2)). */ | |
297 | static int autofs_dev_ioctl_closemount(struct file *fp, | |
298 | struct autofs_sb_info *sbi, | |
299 | struct autofs_dev_ioctl *param) | |
300 | { | |
301 | return sys_close(param->ioctlfd); | |
302 | } | |
303 | ||
304 | /* | |
305 | * Send "ready" status for an existing wait (either a mount or an expire | |
306 | * request). | |
307 | */ | |
308 | static int autofs_dev_ioctl_ready(struct file *fp, | |
309 | struct autofs_sb_info *sbi, | |
310 | struct autofs_dev_ioctl *param) | |
311 | { | |
312 | autofs_wqt_t token; | |
313 | ||
730c9eec | 314 | token = (autofs_wqt_t) param->ready.token; |
8d7b48e0 IK |
315 | return autofs4_wait_release(sbi, token, 0); |
316 | } | |
317 | ||
318 | /* | |
319 | * Send "fail" status for an existing wait (either a mount or an expire | |
320 | * request). | |
321 | */ | |
322 | static int autofs_dev_ioctl_fail(struct file *fp, | |
323 | struct autofs_sb_info *sbi, | |
324 | struct autofs_dev_ioctl *param) | |
325 | { | |
326 | autofs_wqt_t token; | |
327 | int status; | |
328 | ||
730c9eec IK |
329 | token = (autofs_wqt_t) param->fail.token; |
330 | status = param->fail.status ? param->fail.status : -ENOENT; | |
8d7b48e0 IK |
331 | return autofs4_wait_release(sbi, token, status); |
332 | } | |
333 | ||
334 | /* | |
335 | * Set the pipe fd for kernel communication to the daemon. | |
336 | * | |
337 | * Normally this is set at mount using an option but if we | |
338 | * are reconnecting to a busy mount then we need to use this | |
339 | * to tell the autofs mount about the new kernel pipe fd. In | |
340 | * order to protect mounts against incorrectly setting the | |
341 | * pipefd we also require that the autofs mount be catatonic. | |
342 | * | |
343 | * This also sets the process group id used to identify the | |
344 | * controlling process (eg. the owning automount(8) daemon). | |
345 | */ | |
346 | static int autofs_dev_ioctl_setpipefd(struct file *fp, | |
347 | struct autofs_sb_info *sbi, | |
348 | struct autofs_dev_ioctl *param) | |
349 | { | |
350 | int pipefd; | |
351 | int err = 0; | |
6eaba35b | 352 | struct pid *new_pid = NULL; |
8d7b48e0 | 353 | |
730c9eec | 354 | if (param->setpipefd.pipefd == -1) |
8d7b48e0 IK |
355 | return -EINVAL; |
356 | ||
730c9eec | 357 | pipefd = param->setpipefd.pipefd; |
8d7b48e0 IK |
358 | |
359 | mutex_lock(&sbi->wq_mutex); | |
360 | if (!sbi->catatonic) { | |
361 | mutex_unlock(&sbi->wq_mutex); | |
362 | return -EBUSY; | |
363 | } else { | |
6eaba35b SB |
364 | struct file *pipe; |
365 | ||
366 | new_pid = get_task_pid(current, PIDTYPE_PGID); | |
367 | ||
368 | if (ns_of_pid(new_pid) != ns_of_pid(sbi->oz_pgrp)) { | |
369 | AUTOFS_WARN("Not allowed to change PID namespace"); | |
370 | err = -EINVAL; | |
371 | goto out; | |
372 | } | |
373 | ||
374 | pipe = fget(pipefd); | |
3dc8fe4d JJ |
375 | if (!pipe) { |
376 | err = -EBADF; | |
377 | goto out; | |
378 | } | |
64f371bc | 379 | if (autofs_prepare_pipe(pipe) < 0) { |
8d7b48e0 IK |
380 | err = -EPIPE; |
381 | fput(pipe); | |
382 | goto out; | |
383 | } | |
6eaba35b | 384 | swap(sbi->oz_pgrp, new_pid); |
8d7b48e0 IK |
385 | sbi->pipefd = pipefd; |
386 | sbi->pipe = pipe; | |
387 | sbi->catatonic = 0; | |
388 | } | |
389 | out: | |
6eaba35b | 390 | put_pid(new_pid); |
8d7b48e0 IK |
391 | mutex_unlock(&sbi->wq_mutex); |
392 | return err; | |
393 | } | |
394 | ||
395 | /* | |
396 | * Make the autofs mount point catatonic, no longer responsive to | |
397 | * mount requests. Also closes the kernel pipe file descriptor. | |
398 | */ | |
399 | static int autofs_dev_ioctl_catatonic(struct file *fp, | |
400 | struct autofs_sb_info *sbi, | |
401 | struct autofs_dev_ioctl *param) | |
402 | { | |
403 | autofs4_catatonic_mode(sbi); | |
404 | return 0; | |
405 | } | |
406 | ||
407 | /* Set the autofs mount timeout */ | |
408 | static int autofs_dev_ioctl_timeout(struct file *fp, | |
409 | struct autofs_sb_info *sbi, | |
410 | struct autofs_dev_ioctl *param) | |
411 | { | |
412 | unsigned long timeout; | |
413 | ||
730c9eec IK |
414 | timeout = param->timeout.timeout; |
415 | param->timeout.timeout = sbi->exp_timeout / HZ; | |
8d7b48e0 IK |
416 | sbi->exp_timeout = timeout * HZ; |
417 | return 0; | |
418 | } | |
419 | ||
420 | /* | |
421 | * Return the uid and gid of the last request for the mount | |
422 | * | |
423 | * When reconstructing an autofs mount tree with active mounts | |
424 | * we need to re-connect to mounts that may have used the original | |
425 | * process uid and gid (or string variations of them) for mount | |
426 | * lookups within the map entry. | |
427 | */ | |
428 | static int autofs_dev_ioctl_requester(struct file *fp, | |
429 | struct autofs_sb_info *sbi, | |
430 | struct autofs_dev_ioctl *param) | |
431 | { | |
432 | struct autofs_info *ino; | |
4e44b685 | 433 | struct path path; |
8d7b48e0 IK |
434 | dev_t devid; |
435 | int err = -ENOENT; | |
436 | ||
437 | if (param->size <= sizeof(*param)) { | |
438 | err = -EINVAL; | |
439 | goto out; | |
440 | } | |
441 | ||
4e44b685 | 442 | devid = sbi->sb->s_dev; |
8d7b48e0 | 443 | |
730c9eec | 444 | param->requester.uid = param->requester.gid = -1; |
8d7b48e0 | 445 | |
4e44b685 | 446 | err = find_autofs_mount(param->path, &path, test_by_dev, &devid); |
8d7b48e0 IK |
447 | if (err) |
448 | goto out; | |
449 | ||
4e44b685 | 450 | ino = autofs4_dentry_ino(path.dentry); |
8d7b48e0 IK |
451 | if (ino) { |
452 | err = 0; | |
23bfc2a2 | 453 | autofs4_expire_wait(path.dentry, 0); |
8d7b48e0 | 454 | spin_lock(&sbi->fs_lock); |
45634cd8 EB |
455 | param->requester.uid = from_kuid_munged(current_user_ns(), ino->uid); |
456 | param->requester.gid = from_kgid_munged(current_user_ns(), ino->gid); | |
8d7b48e0 IK |
457 | spin_unlock(&sbi->fs_lock); |
458 | } | |
4e44b685 | 459 | path_put(&path); |
8d7b48e0 IK |
460 | out: |
461 | return err; | |
462 | } | |
463 | ||
464 | /* | |
465 | * Call repeatedly until it returns -EAGAIN, meaning there's nothing | |
466 | * more that can be done. | |
467 | */ | |
468 | static int autofs_dev_ioctl_expire(struct file *fp, | |
469 | struct autofs_sb_info *sbi, | |
470 | struct autofs_dev_ioctl *param) | |
471 | { | |
8d7b48e0 | 472 | struct vfsmount *mnt; |
8d7b48e0 IK |
473 | int how; |
474 | ||
730c9eec | 475 | how = param->expire.how; |
8d7b48e0 IK |
476 | mnt = fp->f_path.mnt; |
477 | ||
56fcef75 | 478 | return autofs4_do_expire_multi(sbi->sb, mnt, sbi, how); |
8d7b48e0 IK |
479 | } |
480 | ||
481 | /* Check if autofs mount point is in use */ | |
482 | static int autofs_dev_ioctl_askumount(struct file *fp, | |
483 | struct autofs_sb_info *sbi, | |
484 | struct autofs_dev_ioctl *param) | |
485 | { | |
730c9eec | 486 | param->askumount.may_umount = 0; |
8d7b48e0 | 487 | if (may_umount(fp->f_path.mnt)) |
730c9eec | 488 | param->askumount.may_umount = 1; |
8d7b48e0 IK |
489 | return 0; |
490 | } | |
491 | ||
492 | /* | |
493 | * Check if the given path is a mountpoint. | |
494 | * | |
495 | * If we are supplied with the file descriptor of an autofs | |
496 | * mount we're looking for a specific mount. In this case | |
497 | * the path is considered a mountpoint if it is itself a | |
498 | * mountpoint or contains a mount, such as a multi-mount | |
499 | * without a root mount. In this case we return 1 if the | |
500 | * path is a mount point and the super magic of the covering | |
501 | * mount if there is one or 0 if it isn't a mountpoint. | |
502 | * | |
503 | * If we aren't supplied with a file descriptor then we | |
ac838719 IK |
504 | * lookup the path and check if it is the root of a mount. |
505 | * If a type is given we are looking for a particular autofs | |
506 | * mount and if we don't find a match we return fail. If the | |
507 | * located path is the root of a mount we return 1 along with | |
508 | * the super magic of the mount or 0 otherwise. | |
8d7b48e0 IK |
509 | * |
510 | * In both cases the the device number (as returned by | |
511 | * new_encode_dev()) is also returned. | |
512 | */ | |
513 | static int autofs_dev_ioctl_ismountpoint(struct file *fp, | |
514 | struct autofs_sb_info *sbi, | |
515 | struct autofs_dev_ioctl *param) | |
516 | { | |
4e44b685 AV |
517 | struct path path; |
518 | const char *name; | |
8d7b48e0 | 519 | unsigned int type; |
730c9eec | 520 | unsigned int devid, magic; |
8d7b48e0 IK |
521 | int err = -ENOENT; |
522 | ||
523 | if (param->size <= sizeof(*param)) { | |
524 | err = -EINVAL; | |
525 | goto out; | |
526 | } | |
527 | ||
4e44b685 | 528 | name = param->path; |
730c9eec | 529 | type = param->ismountpoint.in.type; |
8d7b48e0 | 530 | |
730c9eec IK |
531 | param->ismountpoint.out.devid = devid = 0; |
532 | param->ismountpoint.out.magic = magic = 0; | |
8d7b48e0 IK |
533 | |
534 | if (!fp || param->ioctlfd == -1) { | |
4e44b685 | 535 | if (autofs_type_any(type)) |
ac838719 IK |
536 | err = kern_path_mountpoint(AT_FDCWD, |
537 | name, &path, LOOKUP_FOLLOW); | |
4e44b685 | 538 | else |
ac838719 IK |
539 | err = find_autofs_mount(name, &path, |
540 | test_by_type, &type); | |
4e44b685 AV |
541 | if (err) |
542 | goto out; | |
d8c9584e | 543 | devid = new_encode_dev(path.dentry->d_sb->s_dev); |
8d7b48e0 | 544 | err = 0; |
f598f9f1 | 545 | if (path.mnt->mnt_root == path.dentry) { |
8d7b48e0 | 546 | err = 1; |
d8c9584e | 547 | magic = path.dentry->d_sb->s_magic; |
8d7b48e0 IK |
548 | } |
549 | } else { | |
4e44b685 | 550 | dev_t dev = sbi->sb->s_dev; |
8d7b48e0 | 551 | |
4e44b685 | 552 | err = find_autofs_mount(name, &path, test_by_dev, &dev); |
8d7b48e0 IK |
553 | if (err) |
554 | goto out; | |
555 | ||
4e44b685 | 556 | devid = new_encode_dev(dev); |
8d7b48e0 | 557 | |
4e44b685 | 558 | err = have_submounts(path.dentry); |
8d7b48e0 | 559 | |
cc53ce53 | 560 | if (follow_down_one(&path)) |
d8c9584e | 561 | magic = path.dentry->d_sb->s_magic; |
8d7b48e0 IK |
562 | } |
563 | ||
730c9eec IK |
564 | param->ismountpoint.out.devid = devid; |
565 | param->ismountpoint.out.magic = magic; | |
4e44b685 | 566 | path_put(&path); |
8d7b48e0 IK |
567 | out: |
568 | return err; | |
569 | } | |
570 | ||
571 | /* | |
572 | * Our range of ioctl numbers isn't 0 based so we need to shift | |
573 | * the array index by _IOC_NR(AUTOFS_CTL_IOC_FIRST) for the table | |
574 | * lookup. | |
575 | */ | |
576 | #define cmd_idx(cmd) (cmd - _IOC_NR(AUTOFS_DEV_IOCTL_IOC_FIRST)) | |
577 | ||
578 | static ioctl_fn lookup_dev_ioctl(unsigned int cmd) | |
579 | { | |
580 | static struct { | |
581 | int cmd; | |
582 | ioctl_fn fn; | |
583 | } _ioctls[] = { | |
584 | {cmd_idx(AUTOFS_DEV_IOCTL_VERSION_CMD), NULL}, | |
585 | {cmd_idx(AUTOFS_DEV_IOCTL_PROTOVER_CMD), | |
586 | autofs_dev_ioctl_protover}, | |
587 | {cmd_idx(AUTOFS_DEV_IOCTL_PROTOSUBVER_CMD), | |
588 | autofs_dev_ioctl_protosubver}, | |
589 | {cmd_idx(AUTOFS_DEV_IOCTL_OPENMOUNT_CMD), | |
590 | autofs_dev_ioctl_openmount}, | |
591 | {cmd_idx(AUTOFS_DEV_IOCTL_CLOSEMOUNT_CMD), | |
592 | autofs_dev_ioctl_closemount}, | |
593 | {cmd_idx(AUTOFS_DEV_IOCTL_READY_CMD), | |
594 | autofs_dev_ioctl_ready}, | |
595 | {cmd_idx(AUTOFS_DEV_IOCTL_FAIL_CMD), | |
596 | autofs_dev_ioctl_fail}, | |
597 | {cmd_idx(AUTOFS_DEV_IOCTL_SETPIPEFD_CMD), | |
598 | autofs_dev_ioctl_setpipefd}, | |
599 | {cmd_idx(AUTOFS_DEV_IOCTL_CATATONIC_CMD), | |
600 | autofs_dev_ioctl_catatonic}, | |
601 | {cmd_idx(AUTOFS_DEV_IOCTL_TIMEOUT_CMD), | |
602 | autofs_dev_ioctl_timeout}, | |
603 | {cmd_idx(AUTOFS_DEV_IOCTL_REQUESTER_CMD), | |
604 | autofs_dev_ioctl_requester}, | |
605 | {cmd_idx(AUTOFS_DEV_IOCTL_EXPIRE_CMD), | |
606 | autofs_dev_ioctl_expire}, | |
607 | {cmd_idx(AUTOFS_DEV_IOCTL_ASKUMOUNT_CMD), | |
608 | autofs_dev_ioctl_askumount}, | |
609 | {cmd_idx(AUTOFS_DEV_IOCTL_ISMOUNTPOINT_CMD), | |
610 | autofs_dev_ioctl_ismountpoint} | |
611 | }; | |
612 | unsigned int idx = cmd_idx(cmd); | |
613 | ||
614 | return (idx >= ARRAY_SIZE(_ioctls)) ? NULL : _ioctls[idx].fn; | |
615 | } | |
616 | ||
617 | /* ioctl dispatcher */ | |
618 | static int _autofs_dev_ioctl(unsigned int command, struct autofs_dev_ioctl __user *user) | |
619 | { | |
620 | struct autofs_dev_ioctl *param; | |
621 | struct file *fp; | |
622 | struct autofs_sb_info *sbi; | |
623 | unsigned int cmd_first, cmd; | |
624 | ioctl_fn fn = NULL; | |
625 | int err = 0; | |
626 | ||
627 | /* only root can play with this */ | |
628 | if (!capable(CAP_SYS_ADMIN)) | |
629 | return -EPERM; | |
630 | ||
631 | cmd_first = _IOC_NR(AUTOFS_DEV_IOCTL_IOC_FIRST); | |
632 | cmd = _IOC_NR(command); | |
633 | ||
634 | if (_IOC_TYPE(command) != _IOC_TYPE(AUTOFS_DEV_IOCTL_IOC_FIRST) || | |
635 | cmd - cmd_first >= AUTOFS_DEV_IOCTL_IOC_COUNT) { | |
636 | return -ENOTTY; | |
637 | } | |
638 | ||
639 | /* Copy the parameters into kernel space. */ | |
640 | param = copy_dev_ioctl(user); | |
641 | if (IS_ERR(param)) | |
642 | return PTR_ERR(param); | |
643 | ||
644 | err = validate_dev_ioctl(command, param); | |
645 | if (err) | |
646 | goto out; | |
647 | ||
648 | /* The validate routine above always sets the version */ | |
649 | if (cmd == AUTOFS_DEV_IOCTL_VERSION_CMD) | |
650 | goto done; | |
651 | ||
652 | fn = lookup_dev_ioctl(cmd); | |
653 | if (!fn) { | |
654 | AUTOFS_WARN("unknown command 0x%08x", command); | |
655 | return -ENOTTY; | |
656 | } | |
657 | ||
658 | fp = NULL; | |
659 | sbi = NULL; | |
660 | ||
661 | /* | |
662 | * For obvious reasons the openmount can't have a file | |
663 | * descriptor yet. We don't take a reference to the | |
664 | * file during close to allow for immediate release. | |
665 | */ | |
666 | if (cmd != AUTOFS_DEV_IOCTL_OPENMOUNT_CMD && | |
667 | cmd != AUTOFS_DEV_IOCTL_CLOSEMOUNT_CMD) { | |
668 | fp = fget(param->ioctlfd); | |
669 | if (!fp) { | |
670 | if (cmd == AUTOFS_DEV_IOCTL_ISMOUNTPOINT_CMD) | |
671 | goto cont; | |
672 | err = -EBADF; | |
673 | goto out; | |
674 | } | |
675 | ||
8d7b48e0 IK |
676 | sbi = autofs_dev_ioctl_sbi(fp); |
677 | if (!sbi || sbi->magic != AUTOFS_SBI_MAGIC) { | |
678 | err = -EINVAL; | |
679 | fput(fp); | |
680 | goto out; | |
681 | } | |
682 | ||
683 | /* | |
684 | * Admin needs to be able to set the mount catatonic in | |
685 | * order to be able to perform the re-open. | |
686 | */ | |
687 | if (!autofs4_oz_mode(sbi) && | |
688 | cmd != AUTOFS_DEV_IOCTL_CATATONIC_CMD) { | |
689 | err = -EACCES; | |
690 | fput(fp); | |
691 | goto out; | |
692 | } | |
693 | } | |
694 | cont: | |
695 | err = fn(fp, sbi, param); | |
696 | ||
697 | if (fp) | |
698 | fput(fp); | |
699 | done: | |
700 | if (err >= 0 && copy_to_user(user, param, AUTOFS_DEV_IOCTL_SIZE)) | |
701 | err = -EFAULT; | |
702 | out: | |
703 | free_dev_ioctl(param); | |
704 | return err; | |
705 | } | |
706 | ||
707 | static long autofs_dev_ioctl(struct file *file, uint command, ulong u) | |
708 | { | |
709 | int err; | |
710 | err = _autofs_dev_ioctl(command, (struct autofs_dev_ioctl __user *) u); | |
711 | return (long) err; | |
712 | } | |
713 | ||
714 | #ifdef CONFIG_COMPAT | |
715 | static long autofs_dev_ioctl_compat(struct file *file, uint command, ulong u) | |
716 | { | |
717 | return (long) autofs_dev_ioctl(file, command, (ulong) compat_ptr(u)); | |
718 | } | |
719 | #else | |
720 | #define autofs_dev_ioctl_compat NULL | |
721 | #endif | |
722 | ||
723 | static const struct file_operations _dev_ioctl_fops = { | |
724 | .unlocked_ioctl = autofs_dev_ioctl, | |
725 | .compat_ioctl = autofs_dev_ioctl_compat, | |
726 | .owner = THIS_MODULE, | |
6038f373 | 727 | .llseek = noop_llseek, |
8d7b48e0 IK |
728 | }; |
729 | ||
730 | static struct miscdevice _autofs_dev_ioctl_misc = { | |
578454ff | 731 | .minor = AUTOFS_MINOR, |
8d7b48e0 IK |
732 | .name = AUTOFS_DEVICE_NAME, |
733 | .fops = &_dev_ioctl_fops | |
734 | }; | |
735 | ||
578454ff KS |
736 | MODULE_ALIAS_MISCDEV(AUTOFS_MINOR); |
737 | MODULE_ALIAS("devname:autofs"); | |
738 | ||
8d7b48e0 | 739 | /* Register/deregister misc character device */ |
3ff6db32 | 740 | int __init autofs_dev_ioctl_init(void) |
8d7b48e0 IK |
741 | { |
742 | int r; | |
743 | ||
744 | r = misc_register(&_autofs_dev_ioctl_misc); | |
745 | if (r) { | |
746 | AUTOFS_ERROR("misc_register failed for control device"); | |
747 | return r; | |
748 | } | |
749 | ||
750 | return 0; | |
751 | } | |
752 | ||
753 | void autofs_dev_ioctl_exit(void) | |
754 | { | |
755 | misc_deregister(&_autofs_dev_ioctl_misc); | |
756 | return; | |
757 | } | |
758 |