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 | ||
e9a7c2f1 IK |
75 | if ((param->ver_major != AUTOFS_DEV_IOCTL_VERSION_MAJOR) || |
76 | (param->ver_minor > AUTOFS_DEV_IOCTL_VERSION_MINOR)) { | |
8d7b48e0 IK |
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 | */ | |
e9a7c2f1 IK |
96 | static struct autofs_dev_ioctl * |
97 | copy_dev_ioctl(struct autofs_dev_ioctl __user *in) | |
8d7b48e0 | 98 | { |
0a280962 | 99 | struct autofs_dev_ioctl tmp, *res; |
8d7b48e0 IK |
100 | |
101 | if (copy_from_user(&tmp, in, sizeof(tmp))) | |
102 | return ERR_PTR(-EFAULT); | |
103 | ||
104 | if (tmp.size < sizeof(tmp)) | |
105 | return ERR_PTR(-EINVAL); | |
106 | ||
e53d77eb SL |
107 | if (tmp.size > (PATH_MAX + sizeof(tmp))) |
108 | return ERR_PTR(-ENAMETOOLONG); | |
109 | ||
0a280962 AV |
110 | res = memdup_user(in, tmp.size); |
111 | if (!IS_ERR(res)) | |
112 | res->size = tmp.size; | |
113 | ||
114 | return res; | |
8d7b48e0 IK |
115 | } |
116 | ||
117 | static inline void free_dev_ioctl(struct autofs_dev_ioctl *param) | |
118 | { | |
119 | kfree(param); | |
8d7b48e0 IK |
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; |
e9a7c2f1 IK |
200 | int err; |
201 | ||
202 | err = kern_path_mountpoint(AT_FDCWD, pathname, &path, 0); | |
4e44b685 AV |
203 | if (err) |
204 | return err; | |
8d7b48e0 | 205 | err = -ENOENT; |
4e44b685 | 206 | while (path.dentry == path.mnt->mnt_root) { |
d8c9584e | 207 | if (path.dentry->d_sb->s_magic == AUTOFS_SUPER_MAGIC) { |
4e44b685 AV |
208 | if (test(&path, data)) { |
209 | path_get(&path); | |
4e44b685 | 210 | *res = path; |
8d7b48e0 | 211 | err = 0; |
ac838719 | 212 | break; |
8d7b48e0 IK |
213 | } |
214 | } | |
bab77ebf | 215 | if (!follow_up(&path)) |
4e44b685 | 216 | break; |
8d7b48e0 | 217 | } |
4e44b685 | 218 | path_put(&path); |
8d7b48e0 IK |
219 | return err; |
220 | } | |
221 | ||
4e44b685 | 222 | static int test_by_dev(struct path *path, void *p) |
8d7b48e0 | 223 | { |
d8c9584e | 224 | return path->dentry->d_sb->s_dev == *(dev_t *)p; |
4e44b685 | 225 | } |
8d7b48e0 | 226 | |
4e44b685 AV |
227 | static int test_by_type(struct path *path, void *p) |
228 | { | |
229 | struct autofs_info *ino = autofs4_dentry_ino(path->dentry); | |
e9a7c2f1 | 230 | |
4e44b685 | 231 | return ino && ino->sbi->type & *(unsigned *)p; |
8d7b48e0 IK |
232 | } |
233 | ||
8d7b48e0 IK |
234 | /* |
235 | * Open a file descriptor on the autofs mount point corresponding | |
236 | * to the given path and device number (aka. new_encode_dev(sb->s_dev)). | |
237 | */ | |
4e44b685 | 238 | static int autofs_dev_ioctl_open_mountpoint(const char *name, dev_t devid) |
8d7b48e0 | 239 | { |
8d7b48e0 IK |
240 | int err, fd; |
241 | ||
c921b40d | 242 | fd = get_unused_fd_flags(O_CLOEXEC); |
8d7b48e0 | 243 | if (likely(fd >= 0)) { |
4e44b685 AV |
244 | struct file *filp; |
245 | struct path path; | |
246 | ||
247 | err = find_autofs_mount(name, &path, test_by_dev, &devid); | |
8d7b48e0 IK |
248 | if (err) |
249 | goto out; | |
250 | ||
251 | /* | |
4e44b685 | 252 | * Find autofs super block that has the device number |
8d7b48e0 IK |
253 | * corresponding to the autofs fs we want to open. |
254 | */ | |
8d7b48e0 | 255 | |
765927b2 AV |
256 | filp = dentry_open(&path, O_RDONLY, current_cred()); |
257 | path_put(&path); | |
8d7b48e0 IK |
258 | if (IS_ERR(filp)) { |
259 | err = PTR_ERR(filp); | |
260 | goto out; | |
261 | } | |
262 | ||
c921b40d | 263 | fd_install(fd, filp); |
8d7b48e0 IK |
264 | } |
265 | ||
266 | return fd; | |
267 | ||
268 | out: | |
269 | put_unused_fd(fd); | |
270 | return err; | |
271 | } | |
272 | ||
273 | /* Open a file descriptor on an autofs mount point */ | |
274 | static int autofs_dev_ioctl_openmount(struct file *fp, | |
275 | struct autofs_sb_info *sbi, | |
276 | struct autofs_dev_ioctl *param) | |
277 | { | |
278 | const char *path; | |
279 | dev_t devid; | |
280 | int err, fd; | |
281 | ||
282 | /* param->path has already been checked */ | |
730c9eec | 283 | if (!param->openmount.devid) |
8d7b48e0 IK |
284 | return -EINVAL; |
285 | ||
286 | param->ioctlfd = -1; | |
287 | ||
288 | path = param->path; | |
4e44b685 | 289 | devid = new_decode_dev(param->openmount.devid); |
8d7b48e0 IK |
290 | |
291 | err = 0; | |
292 | fd = autofs_dev_ioctl_open_mountpoint(path, devid); | |
293 | if (unlikely(fd < 0)) { | |
294 | err = fd; | |
295 | goto out; | |
296 | } | |
297 | ||
298 | param->ioctlfd = fd; | |
299 | out: | |
300 | return err; | |
301 | } | |
302 | ||
303 | /* Close file descriptor allocated above (user can also use close(2)). */ | |
304 | static int autofs_dev_ioctl_closemount(struct file *fp, | |
305 | struct autofs_sb_info *sbi, | |
306 | struct autofs_dev_ioctl *param) | |
307 | { | |
308 | return sys_close(param->ioctlfd); | |
309 | } | |
310 | ||
311 | /* | |
312 | * Send "ready" status for an existing wait (either a mount or an expire | |
313 | * request). | |
314 | */ | |
315 | static int autofs_dev_ioctl_ready(struct file *fp, | |
316 | struct autofs_sb_info *sbi, | |
317 | struct autofs_dev_ioctl *param) | |
318 | { | |
319 | autofs_wqt_t token; | |
320 | ||
730c9eec | 321 | token = (autofs_wqt_t) param->ready.token; |
8d7b48e0 IK |
322 | return autofs4_wait_release(sbi, token, 0); |
323 | } | |
324 | ||
325 | /* | |
326 | * Send "fail" status for an existing wait (either a mount or an expire | |
327 | * request). | |
328 | */ | |
329 | static int autofs_dev_ioctl_fail(struct file *fp, | |
330 | struct autofs_sb_info *sbi, | |
331 | struct autofs_dev_ioctl *param) | |
332 | { | |
333 | autofs_wqt_t token; | |
334 | int status; | |
335 | ||
730c9eec IK |
336 | token = (autofs_wqt_t) param->fail.token; |
337 | status = param->fail.status ? param->fail.status : -ENOENT; | |
8d7b48e0 IK |
338 | return autofs4_wait_release(sbi, token, status); |
339 | } | |
340 | ||
341 | /* | |
342 | * Set the pipe fd for kernel communication to the daemon. | |
343 | * | |
344 | * Normally this is set at mount using an option but if we | |
345 | * are reconnecting to a busy mount then we need to use this | |
346 | * to tell the autofs mount about the new kernel pipe fd. In | |
347 | * order to protect mounts against incorrectly setting the | |
348 | * pipefd we also require that the autofs mount be catatonic. | |
349 | * | |
350 | * This also sets the process group id used to identify the | |
351 | * controlling process (eg. the owning automount(8) daemon). | |
352 | */ | |
353 | static int autofs_dev_ioctl_setpipefd(struct file *fp, | |
354 | struct autofs_sb_info *sbi, | |
355 | struct autofs_dev_ioctl *param) | |
356 | { | |
357 | int pipefd; | |
358 | int err = 0; | |
6eaba35b | 359 | struct pid *new_pid = NULL; |
8d7b48e0 | 360 | |
730c9eec | 361 | if (param->setpipefd.pipefd == -1) |
8d7b48e0 IK |
362 | return -EINVAL; |
363 | ||
730c9eec | 364 | pipefd = param->setpipefd.pipefd; |
8d7b48e0 IK |
365 | |
366 | mutex_lock(&sbi->wq_mutex); | |
367 | if (!sbi->catatonic) { | |
368 | mutex_unlock(&sbi->wq_mutex); | |
369 | return -EBUSY; | |
370 | } else { | |
6eaba35b SB |
371 | struct file *pipe; |
372 | ||
373 | new_pid = get_task_pid(current, PIDTYPE_PGID); | |
374 | ||
375 | if (ns_of_pid(new_pid) != ns_of_pid(sbi->oz_pgrp)) { | |
376 | AUTOFS_WARN("Not allowed to change PID namespace"); | |
377 | err = -EINVAL; | |
378 | goto out; | |
379 | } | |
380 | ||
381 | pipe = fget(pipefd); | |
3dc8fe4d JJ |
382 | if (!pipe) { |
383 | err = -EBADF; | |
384 | goto out; | |
385 | } | |
64f371bc | 386 | if (autofs_prepare_pipe(pipe) < 0) { |
8d7b48e0 IK |
387 | err = -EPIPE; |
388 | fput(pipe); | |
389 | goto out; | |
390 | } | |
6eaba35b | 391 | swap(sbi->oz_pgrp, new_pid); |
8d7b48e0 IK |
392 | sbi->pipefd = pipefd; |
393 | sbi->pipe = pipe; | |
394 | sbi->catatonic = 0; | |
395 | } | |
396 | out: | |
6eaba35b | 397 | put_pid(new_pid); |
8d7b48e0 IK |
398 | mutex_unlock(&sbi->wq_mutex); |
399 | return err; | |
400 | } | |
401 | ||
402 | /* | |
403 | * Make the autofs mount point catatonic, no longer responsive to | |
404 | * mount requests. Also closes the kernel pipe file descriptor. | |
405 | */ | |
406 | static int autofs_dev_ioctl_catatonic(struct file *fp, | |
407 | struct autofs_sb_info *sbi, | |
408 | struct autofs_dev_ioctl *param) | |
409 | { | |
410 | autofs4_catatonic_mode(sbi); | |
411 | return 0; | |
412 | } | |
413 | ||
414 | /* Set the autofs mount timeout */ | |
415 | static int autofs_dev_ioctl_timeout(struct file *fp, | |
416 | struct autofs_sb_info *sbi, | |
417 | struct autofs_dev_ioctl *param) | |
418 | { | |
419 | unsigned long timeout; | |
420 | ||
730c9eec IK |
421 | timeout = param->timeout.timeout; |
422 | param->timeout.timeout = sbi->exp_timeout / HZ; | |
8d7b48e0 IK |
423 | sbi->exp_timeout = timeout * HZ; |
424 | return 0; | |
425 | } | |
426 | ||
427 | /* | |
428 | * Return the uid and gid of the last request for the mount | |
429 | * | |
430 | * When reconstructing an autofs mount tree with active mounts | |
431 | * we need to re-connect to mounts that may have used the original | |
432 | * process uid and gid (or string variations of them) for mount | |
433 | * lookups within the map entry. | |
434 | */ | |
435 | static int autofs_dev_ioctl_requester(struct file *fp, | |
436 | struct autofs_sb_info *sbi, | |
437 | struct autofs_dev_ioctl *param) | |
438 | { | |
439 | struct autofs_info *ino; | |
4e44b685 | 440 | struct path path; |
8d7b48e0 IK |
441 | dev_t devid; |
442 | int err = -ENOENT; | |
443 | ||
444 | if (param->size <= sizeof(*param)) { | |
445 | err = -EINVAL; | |
446 | goto out; | |
447 | } | |
448 | ||
4e44b685 | 449 | devid = sbi->sb->s_dev; |
8d7b48e0 | 450 | |
730c9eec | 451 | param->requester.uid = param->requester.gid = -1; |
8d7b48e0 | 452 | |
4e44b685 | 453 | err = find_autofs_mount(param->path, &path, test_by_dev, &devid); |
8d7b48e0 IK |
454 | if (err) |
455 | goto out; | |
456 | ||
4e44b685 | 457 | ino = autofs4_dentry_ino(path.dentry); |
8d7b48e0 IK |
458 | if (ino) { |
459 | err = 0; | |
23bfc2a2 | 460 | autofs4_expire_wait(path.dentry, 0); |
8d7b48e0 | 461 | spin_lock(&sbi->fs_lock); |
e9a7c2f1 IK |
462 | param->requester.uid = |
463 | from_kuid_munged(current_user_ns(), ino->uid); | |
464 | param->requester.gid = | |
465 | from_kgid_munged(current_user_ns(), ino->gid); | |
8d7b48e0 IK |
466 | spin_unlock(&sbi->fs_lock); |
467 | } | |
4e44b685 | 468 | path_put(&path); |
8d7b48e0 IK |
469 | out: |
470 | return err; | |
471 | } | |
472 | ||
473 | /* | |
474 | * Call repeatedly until it returns -EAGAIN, meaning there's nothing | |
475 | * more that can be done. | |
476 | */ | |
477 | static int autofs_dev_ioctl_expire(struct file *fp, | |
478 | struct autofs_sb_info *sbi, | |
479 | struct autofs_dev_ioctl *param) | |
480 | { | |
8d7b48e0 | 481 | struct vfsmount *mnt; |
8d7b48e0 IK |
482 | int how; |
483 | ||
730c9eec | 484 | how = param->expire.how; |
8d7b48e0 IK |
485 | mnt = fp->f_path.mnt; |
486 | ||
56fcef75 | 487 | return autofs4_do_expire_multi(sbi->sb, mnt, sbi, how); |
8d7b48e0 IK |
488 | } |
489 | ||
490 | /* Check if autofs mount point is in use */ | |
491 | static int autofs_dev_ioctl_askumount(struct file *fp, | |
492 | struct autofs_sb_info *sbi, | |
493 | struct autofs_dev_ioctl *param) | |
494 | { | |
730c9eec | 495 | param->askumount.may_umount = 0; |
8d7b48e0 | 496 | if (may_umount(fp->f_path.mnt)) |
730c9eec | 497 | param->askumount.may_umount = 1; |
8d7b48e0 IK |
498 | return 0; |
499 | } | |
500 | ||
501 | /* | |
502 | * Check if the given path is a mountpoint. | |
503 | * | |
504 | * If we are supplied with the file descriptor of an autofs | |
505 | * mount we're looking for a specific mount. In this case | |
506 | * the path is considered a mountpoint if it is itself a | |
507 | * mountpoint or contains a mount, such as a multi-mount | |
508 | * without a root mount. In this case we return 1 if the | |
509 | * path is a mount point and the super magic of the covering | |
510 | * mount if there is one or 0 if it isn't a mountpoint. | |
511 | * | |
512 | * If we aren't supplied with a file descriptor then we | |
ac838719 IK |
513 | * lookup the path and check if it is the root of a mount. |
514 | * If a type is given we are looking for a particular autofs | |
515 | * mount and if we don't find a match we return fail. If the | |
516 | * located path is the root of a mount we return 1 along with | |
517 | * the super magic of the mount or 0 otherwise. | |
8d7b48e0 IK |
518 | * |
519 | * In both cases the the device number (as returned by | |
520 | * new_encode_dev()) is also returned. | |
521 | */ | |
522 | static int autofs_dev_ioctl_ismountpoint(struct file *fp, | |
523 | struct autofs_sb_info *sbi, | |
524 | struct autofs_dev_ioctl *param) | |
525 | { | |
4e44b685 AV |
526 | struct path path; |
527 | const char *name; | |
8d7b48e0 | 528 | unsigned int type; |
730c9eec | 529 | unsigned int devid, magic; |
8d7b48e0 IK |
530 | int err = -ENOENT; |
531 | ||
532 | if (param->size <= sizeof(*param)) { | |
533 | err = -EINVAL; | |
534 | goto out; | |
535 | } | |
536 | ||
4e44b685 | 537 | name = param->path; |
730c9eec | 538 | type = param->ismountpoint.in.type; |
8d7b48e0 | 539 | |
730c9eec IK |
540 | param->ismountpoint.out.devid = devid = 0; |
541 | param->ismountpoint.out.magic = magic = 0; | |
8d7b48e0 IK |
542 | |
543 | if (!fp || param->ioctlfd == -1) { | |
4e44b685 | 544 | if (autofs_type_any(type)) |
ac838719 IK |
545 | err = kern_path_mountpoint(AT_FDCWD, |
546 | name, &path, LOOKUP_FOLLOW); | |
4e44b685 | 547 | else |
ac838719 IK |
548 | err = find_autofs_mount(name, &path, |
549 | test_by_type, &type); | |
4e44b685 AV |
550 | if (err) |
551 | goto out; | |
d8c9584e | 552 | devid = new_encode_dev(path.dentry->d_sb->s_dev); |
8d7b48e0 | 553 | err = 0; |
f598f9f1 | 554 | if (path.mnt->mnt_root == path.dentry) { |
8d7b48e0 | 555 | err = 1; |
d8c9584e | 556 | magic = path.dentry->d_sb->s_magic; |
8d7b48e0 IK |
557 | } |
558 | } else { | |
4e44b685 | 559 | dev_t dev = sbi->sb->s_dev; |
8d7b48e0 | 560 | |
4e44b685 | 561 | err = find_autofs_mount(name, &path, test_by_dev, &dev); |
8d7b48e0 IK |
562 | if (err) |
563 | goto out; | |
564 | ||
4e44b685 | 565 | devid = new_encode_dev(dev); |
8d7b48e0 | 566 | |
4e44b685 | 567 | err = have_submounts(path.dentry); |
8d7b48e0 | 568 | |
cc53ce53 | 569 | if (follow_down_one(&path)) |
d8c9584e | 570 | magic = path.dentry->d_sb->s_magic; |
8d7b48e0 IK |
571 | } |
572 | ||
730c9eec IK |
573 | param->ismountpoint.out.devid = devid; |
574 | param->ismountpoint.out.magic = magic; | |
4e44b685 | 575 | path_put(&path); |
8d7b48e0 IK |
576 | out: |
577 | return err; | |
578 | } | |
579 | ||
580 | /* | |
581 | * Our range of ioctl numbers isn't 0 based so we need to shift | |
582 | * the array index by _IOC_NR(AUTOFS_CTL_IOC_FIRST) for the table | |
583 | * lookup. | |
584 | */ | |
585 | #define cmd_idx(cmd) (cmd - _IOC_NR(AUTOFS_DEV_IOCTL_IOC_FIRST)) | |
586 | ||
587 | static ioctl_fn lookup_dev_ioctl(unsigned int cmd) | |
588 | { | |
589 | static struct { | |
590 | int cmd; | |
591 | ioctl_fn fn; | |
592 | } _ioctls[] = { | |
593 | {cmd_idx(AUTOFS_DEV_IOCTL_VERSION_CMD), NULL}, | |
594 | {cmd_idx(AUTOFS_DEV_IOCTL_PROTOVER_CMD), | |
595 | autofs_dev_ioctl_protover}, | |
596 | {cmd_idx(AUTOFS_DEV_IOCTL_PROTOSUBVER_CMD), | |
597 | autofs_dev_ioctl_protosubver}, | |
598 | {cmd_idx(AUTOFS_DEV_IOCTL_OPENMOUNT_CMD), | |
599 | autofs_dev_ioctl_openmount}, | |
600 | {cmd_idx(AUTOFS_DEV_IOCTL_CLOSEMOUNT_CMD), | |
601 | autofs_dev_ioctl_closemount}, | |
602 | {cmd_idx(AUTOFS_DEV_IOCTL_READY_CMD), | |
603 | autofs_dev_ioctl_ready}, | |
604 | {cmd_idx(AUTOFS_DEV_IOCTL_FAIL_CMD), | |
605 | autofs_dev_ioctl_fail}, | |
606 | {cmd_idx(AUTOFS_DEV_IOCTL_SETPIPEFD_CMD), | |
607 | autofs_dev_ioctl_setpipefd}, | |
608 | {cmd_idx(AUTOFS_DEV_IOCTL_CATATONIC_CMD), | |
609 | autofs_dev_ioctl_catatonic}, | |
610 | {cmd_idx(AUTOFS_DEV_IOCTL_TIMEOUT_CMD), | |
611 | autofs_dev_ioctl_timeout}, | |
612 | {cmd_idx(AUTOFS_DEV_IOCTL_REQUESTER_CMD), | |
613 | autofs_dev_ioctl_requester}, | |
614 | {cmd_idx(AUTOFS_DEV_IOCTL_EXPIRE_CMD), | |
615 | autofs_dev_ioctl_expire}, | |
616 | {cmd_idx(AUTOFS_DEV_IOCTL_ASKUMOUNT_CMD), | |
617 | autofs_dev_ioctl_askumount}, | |
618 | {cmd_idx(AUTOFS_DEV_IOCTL_ISMOUNTPOINT_CMD), | |
619 | autofs_dev_ioctl_ismountpoint} | |
620 | }; | |
621 | unsigned int idx = cmd_idx(cmd); | |
622 | ||
623 | return (idx >= ARRAY_SIZE(_ioctls)) ? NULL : _ioctls[idx].fn; | |
624 | } | |
625 | ||
626 | /* ioctl dispatcher */ | |
e9a7c2f1 IK |
627 | static int _autofs_dev_ioctl(unsigned int command, |
628 | struct autofs_dev_ioctl __user *user) | |
8d7b48e0 IK |
629 | { |
630 | struct autofs_dev_ioctl *param; | |
631 | struct file *fp; | |
632 | struct autofs_sb_info *sbi; | |
633 | unsigned int cmd_first, cmd; | |
634 | ioctl_fn fn = NULL; | |
635 | int err = 0; | |
636 | ||
637 | /* only root can play with this */ | |
638 | if (!capable(CAP_SYS_ADMIN)) | |
639 | return -EPERM; | |
640 | ||
641 | cmd_first = _IOC_NR(AUTOFS_DEV_IOCTL_IOC_FIRST); | |
642 | cmd = _IOC_NR(command); | |
643 | ||
644 | if (_IOC_TYPE(command) != _IOC_TYPE(AUTOFS_DEV_IOCTL_IOC_FIRST) || | |
645 | cmd - cmd_first >= AUTOFS_DEV_IOCTL_IOC_COUNT) { | |
646 | return -ENOTTY; | |
647 | } | |
648 | ||
649 | /* Copy the parameters into kernel space. */ | |
650 | param = copy_dev_ioctl(user); | |
651 | if (IS_ERR(param)) | |
652 | return PTR_ERR(param); | |
653 | ||
654 | err = validate_dev_ioctl(command, param); | |
655 | if (err) | |
656 | goto out; | |
657 | ||
658 | /* The validate routine above always sets the version */ | |
659 | if (cmd == AUTOFS_DEV_IOCTL_VERSION_CMD) | |
660 | goto done; | |
661 | ||
662 | fn = lookup_dev_ioctl(cmd); | |
663 | if (!fn) { | |
664 | AUTOFS_WARN("unknown command 0x%08x", command); | |
665 | return -ENOTTY; | |
666 | } | |
667 | ||
668 | fp = NULL; | |
669 | sbi = NULL; | |
670 | ||
671 | /* | |
672 | * For obvious reasons the openmount can't have a file | |
673 | * descriptor yet. We don't take a reference to the | |
674 | * file during close to allow for immediate release. | |
675 | */ | |
676 | if (cmd != AUTOFS_DEV_IOCTL_OPENMOUNT_CMD && | |
677 | cmd != AUTOFS_DEV_IOCTL_CLOSEMOUNT_CMD) { | |
678 | fp = fget(param->ioctlfd); | |
679 | if (!fp) { | |
680 | if (cmd == AUTOFS_DEV_IOCTL_ISMOUNTPOINT_CMD) | |
681 | goto cont; | |
682 | err = -EBADF; | |
683 | goto out; | |
684 | } | |
685 | ||
8d7b48e0 IK |
686 | sbi = autofs_dev_ioctl_sbi(fp); |
687 | if (!sbi || sbi->magic != AUTOFS_SBI_MAGIC) { | |
688 | err = -EINVAL; | |
689 | fput(fp); | |
690 | goto out; | |
691 | } | |
692 | ||
693 | /* | |
694 | * Admin needs to be able to set the mount catatonic in | |
695 | * order to be able to perform the re-open. | |
696 | */ | |
697 | if (!autofs4_oz_mode(sbi) && | |
698 | cmd != AUTOFS_DEV_IOCTL_CATATONIC_CMD) { | |
699 | err = -EACCES; | |
700 | fput(fp); | |
701 | goto out; | |
702 | } | |
703 | } | |
704 | cont: | |
705 | err = fn(fp, sbi, param); | |
706 | ||
707 | if (fp) | |
708 | fput(fp); | |
709 | done: | |
710 | if (err >= 0 && copy_to_user(user, param, AUTOFS_DEV_IOCTL_SIZE)) | |
711 | err = -EFAULT; | |
712 | out: | |
713 | free_dev_ioctl(param); | |
714 | return err; | |
715 | } | |
716 | ||
717 | static long autofs_dev_ioctl(struct file *file, uint command, ulong u) | |
718 | { | |
719 | int err; | |
e9a7c2f1 | 720 | |
8d7b48e0 IK |
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, | |
6038f373 | 738 | .llseek = noop_llseek, |
8d7b48e0 IK |
739 | }; |
740 | ||
741 | static struct miscdevice _autofs_dev_ioctl_misc = { | |
578454ff | 742 | .minor = AUTOFS_MINOR, |
e9a7c2f1 IK |
743 | .name = AUTOFS_DEVICE_NAME, |
744 | .fops = &_dev_ioctl_fops | |
8d7b48e0 IK |
745 | }; |
746 | ||
578454ff KS |
747 | MODULE_ALIAS_MISCDEV(AUTOFS_MINOR); |
748 | MODULE_ALIAS("devname:autofs"); | |
749 | ||
8d7b48e0 | 750 | /* Register/deregister misc character device */ |
3ff6db32 | 751 | int __init autofs_dev_ioctl_init(void) |
8d7b48e0 IK |
752 | { |
753 | int r; | |
754 | ||
755 | r = misc_register(&_autofs_dev_ioctl_misc); | |
756 | if (r) { | |
757 | AUTOFS_ERROR("misc_register failed for control device"); | |
758 | return r; | |
759 | } | |
760 | ||
761 | return 0; | |
762 | } | |
763 | ||
764 | void autofs_dev_ioctl_exit(void) | |
765 | { | |
766 | misc_deregister(&_autofs_dev_ioctl_misc); | |
8d7b48e0 IK |
767 | } |
768 |