blob: aaf96cb25452cf04a5d7a47f2b506486e67cd502 [file] [log] [blame]
Ian Kent8d7b48e2008-10-15 22:02:54 -07001/*
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>
Ian Kent8d7b48e2008-10-15 22:02:54 -070022#include <linux/magic.h>
23#include <linux/dcache.h>
24#include <linux/uaccess.h>
Tejun Heo5a0e3ad2010-03-24 17:04:11 +090025#include <linux/slab.h>
Ian Kent8d7b48e2008-10-15 22:02:54 -070026
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
43typedef int (*ioctl_fn)(struct file *, struct autofs_sb_info *,
44 struct autofs_dev_ioctl *);
45
46static 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 */
Al Viro3eac8772009-04-07 11:12:46 -040057static int invalid_str(char *str, size_t size)
Ian Kent8d7b48e2008-10-15 22:02:54 -070058{
Al Viro3eac8772009-04-07 11:12:46 -040059 if (memchr(str, 0, size))
60 return 0;
Ian Kent8d7b48e2008-10-15 22:02:54 -070061 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 */
71static 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 */
96static struct autofs_dev_ioctl *copy_dev_ioctl(struct autofs_dev_ioctl __user *in)
97{
Julia Lawall7ca5ca62010-05-26 14:42:13 -070098 struct autofs_dev_ioctl tmp;
Ian Kent8d7b48e2008-10-15 22:02:54 -070099
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
Sasha Levine53d77e2014-04-08 16:04:11 -0700106 if (tmp.size > (PATH_MAX + sizeof(tmp)))
107 return ERR_PTR(-ENAMETOOLONG);
108
Julia Lawall7ca5ca62010-05-26 14:42:13 -0700109 return memdup_user(in, tmp.size);
Ian Kent8d7b48e2008-10-15 22:02:54 -0700110}
111
112static 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
Ian Kentbae8ec62009-01-06 14:42:09 -0800120 * check that it is terminated and contains at least one "/".
Ian Kent8d7b48e2008-10-15 22:02:54 -0700121 */
122static int validate_dev_ioctl(int cmd, struct autofs_dev_ioctl *param)
123{
Ian Kent96b03172008-11-06 12:53:23 -0800124 int err;
Ian Kent8d7b48e2008-10-15 22:02:54 -0700125
Ian Kent96b03172008-11-06 12:53:23 -0800126 err = check_dev_ioctl_version(cmd, param);
127 if (err) {
Ian Kent8d7b48e2008-10-15 22:02:54 -0700128 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)) {
Al Viro3eac8772009-04-07 11:12:46 -0400134 err = invalid_str(param->path, param->size - sizeof(*param));
Ian Kent8d7b48e2008-10-15 22:02:54 -0700135 if (err) {
Ian Kentbae8ec62009-01-06 14:42:09 -0800136 AUTOFS_WARN(
137 "path string terminator missing for cmd(0x%08x)",
138 cmd);
Ian Kent8d7b48e2008-10-15 22:02:54 -0700139 goto out;
140 }
141
Ian Kentbae8ec62009-01-06 14:42:09 -0800142 err = check_name(param->path);
Ian Kent8d7b48e2008-10-15 22:02:54 -0700143 if (err) {
144 AUTOFS_WARN("invalid path supplied for cmd(0x%08x)",
145 cmd);
146 goto out;
147 }
148 }
149
150 err = 0;
151out:
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 */
159static 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) {
Al Viro496ad9a2013-01-23 17:07:38 -0500165 inode = file_inode(f);
Ian Kent8d7b48e2008-10-15 22:02:54 -0700166 sbi = autofs4_sbi(inode->i_sb);
167 }
168 return sbi;
169}
170
171/* Return autofs module protocol version */
172static int autofs_dev_ioctl_protover(struct file *fp,
173 struct autofs_sb_info *sbi,
174 struct autofs_dev_ioctl *param)
175{
Ian Kent730c9ee2009-01-06 14:42:06 -0800176 param->protover.version = sbi->version;
Ian Kent8d7b48e2008-10-15 22:02:54 -0700177 return 0;
178}
179
180/* Return autofs module protocol sub version */
181static int autofs_dev_ioctl_protosubver(struct file *fp,
182 struct autofs_sb_info *sbi,
183 struct autofs_dev_ioctl *param)
184{
Ian Kent730c9ee2009-01-06 14:42:06 -0800185 param->protosubver.sub_version = sbi->sub_version;
Ian Kent8d7b48e2008-10-15 22:02:54 -0700186 return 0;
187}
188
Ian Kentac838712013-09-08 16:47:23 +0800189/* Find the topmost mount satisfying test() */
Al Viro4e44b682009-04-07 11:08:56 -0400190static int find_autofs_mount(const char *pathname,
191 struct path *res,
192 int test(struct path *path, void *data),
193 void *data)
Ian Kent8d7b48e2008-10-15 22:02:54 -0700194{
Al Viro4e44b682009-04-07 11:08:56 -0400195 struct path path;
Ian Kentac838712013-09-08 16:47:23 +0800196 int err = kern_path_mountpoint(AT_FDCWD, pathname, &path, 0);
Al Viro4e44b682009-04-07 11:08:56 -0400197 if (err)
198 return err;
Ian Kent8d7b48e2008-10-15 22:02:54 -0700199 err = -ENOENT;
Al Viro4e44b682009-04-07 11:08:56 -0400200 while (path.dentry == path.mnt->mnt_root) {
Al Virod8c95842011-12-07 18:16:57 -0500201 if (path.dentry->d_sb->s_magic == AUTOFS_SUPER_MAGIC) {
Al Viro4e44b682009-04-07 11:08:56 -0400202 if (test(&path, data)) {
203 path_get(&path);
Al Viro4e44b682009-04-07 11:08:56 -0400204 *res = path;
Ian Kent8d7b48e2008-10-15 22:02:54 -0700205 err = 0;
Ian Kentac838712013-09-08 16:47:23 +0800206 break;
Ian Kent8d7b48e2008-10-15 22:02:54 -0700207 }
208 }
Al Virobab77eb2009-04-18 03:26:48 -0400209 if (!follow_up(&path))
Al Viro4e44b682009-04-07 11:08:56 -0400210 break;
Ian Kent8d7b48e2008-10-15 22:02:54 -0700211 }
Al Viro4e44b682009-04-07 11:08:56 -0400212 path_put(&path);
Ian Kent8d7b48e2008-10-15 22:02:54 -0700213 return err;
214}
215
Al Viro4e44b682009-04-07 11:08:56 -0400216static int test_by_dev(struct path *path, void *p)
Ian Kent8d7b48e2008-10-15 22:02:54 -0700217{
Al Virod8c95842011-12-07 18:16:57 -0500218 return path->dentry->d_sb->s_dev == *(dev_t *)p;
Al Viro4e44b682009-04-07 11:08:56 -0400219}
Ian Kent8d7b48e2008-10-15 22:02:54 -0700220
Al Viro4e44b682009-04-07 11:08:56 -0400221static 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;
Ian Kent8d7b48e2008-10-15 22:02:54 -0700225}
226
Ian Kent8d7b48e2008-10-15 22:02:54 -0700227/*
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 */
Al Viro4e44b682009-04-07 11:08:56 -0400231static int autofs_dev_ioctl_open_mountpoint(const char *name, dev_t devid)
Ian Kent8d7b48e2008-10-15 22:02:54 -0700232{
Ian Kent8d7b48e2008-10-15 22:02:54 -0700233 int err, fd;
234
Al Viroc921b402012-08-12 18:04:37 -0400235 fd = get_unused_fd_flags(O_CLOEXEC);
Ian Kent8d7b48e2008-10-15 22:02:54 -0700236 if (likely(fd >= 0)) {
Al Viro4e44b682009-04-07 11:08:56 -0400237 struct file *filp;
238 struct path path;
239
240 err = find_autofs_mount(name, &path, test_by_dev, &devid);
Ian Kent8d7b48e2008-10-15 22:02:54 -0700241 if (err)
242 goto out;
243
244 /*
Al Viro4e44b682009-04-07 11:08:56 -0400245 * Find autofs super block that has the device number
Ian Kent8d7b48e2008-10-15 22:02:54 -0700246 * corresponding to the autofs fs we want to open.
247 */
Ian Kent8d7b48e2008-10-15 22:02:54 -0700248
Al Viro765927b2012-06-26 21:58:53 +0400249 filp = dentry_open(&path, O_RDONLY, current_cred());
250 path_put(&path);
Ian Kent8d7b48e2008-10-15 22:02:54 -0700251 if (IS_ERR(filp)) {
252 err = PTR_ERR(filp);
253 goto out;
254 }
255
Al Viroc921b402012-08-12 18:04:37 -0400256 fd_install(fd, filp);
Ian Kent8d7b48e2008-10-15 22:02:54 -0700257 }
258
259 return fd;
260
261out:
262 put_unused_fd(fd);
263 return err;
264}
265
266/* Open a file descriptor on an autofs mount point */
267static 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 */
Ian Kent730c9ee2009-01-06 14:42:06 -0800276 if (!param->openmount.devid)
Ian Kent8d7b48e2008-10-15 22:02:54 -0700277 return -EINVAL;
278
279 param->ioctlfd = -1;
280
281 path = param->path;
Al Viro4e44b682009-04-07 11:08:56 -0400282 devid = new_decode_dev(param->openmount.devid);
Ian Kent8d7b48e2008-10-15 22:02:54 -0700283
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;
292out:
293 return err;
294}
295
296/* Close file descriptor allocated above (user can also use close(2)). */
297static 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 */
308static 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
Ian Kent730c9ee2009-01-06 14:42:06 -0800314 token = (autofs_wqt_t) param->ready.token;
Ian Kent8d7b48e2008-10-15 22:02:54 -0700315 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 */
322static 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
Ian Kent730c9ee2009-01-06 14:42:06 -0800329 token = (autofs_wqt_t) param->fail.token;
330 status = param->fail.status ? param->fail.status : -ENOENT;
Ian Kent8d7b48e2008-10-15 22:02:54 -0700331 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 */
346static 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;
Sukadev Bhattiprolu6eaba352014-01-23 15:54:57 -0800352 struct pid *new_pid = NULL;
Ian Kent8d7b48e2008-10-15 22:02:54 -0700353
Ian Kent730c9ee2009-01-06 14:42:06 -0800354 if (param->setpipefd.pipefd == -1)
Ian Kent8d7b48e2008-10-15 22:02:54 -0700355 return -EINVAL;
356
Ian Kent730c9ee2009-01-06 14:42:06 -0800357 pipefd = param->setpipefd.pipefd;
Ian Kent8d7b48e2008-10-15 22:02:54 -0700358
359 mutex_lock(&sbi->wq_mutex);
360 if (!sbi->catatonic) {
361 mutex_unlock(&sbi->wq_mutex);
362 return -EBUSY;
363 } else {
Sukadev Bhattiprolu6eaba352014-01-23 15:54:57 -0800364 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);
Jesper Juhl3dc8fe42011-03-25 01:51:37 +0800375 if (!pipe) {
376 err = -EBADF;
377 goto out;
378 }
Linus Torvalds64f371b2012-04-29 13:30:08 -0700379 if (autofs_prepare_pipe(pipe) < 0) {
Ian Kent8d7b48e2008-10-15 22:02:54 -0700380 err = -EPIPE;
381 fput(pipe);
382 goto out;
383 }
Sukadev Bhattiprolu6eaba352014-01-23 15:54:57 -0800384 swap(sbi->oz_pgrp, new_pid);
Ian Kent8d7b48e2008-10-15 22:02:54 -0700385 sbi->pipefd = pipefd;
386 sbi->pipe = pipe;
387 sbi->catatonic = 0;
388 }
389out:
Sukadev Bhattiprolu6eaba352014-01-23 15:54:57 -0800390 put_pid(new_pid);
Ian Kent8d7b48e2008-10-15 22:02:54 -0700391 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 */
399static 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 */
408static 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
Ian Kent730c9ee2009-01-06 14:42:06 -0800414 timeout = param->timeout.timeout;
415 param->timeout.timeout = sbi->exp_timeout / HZ;
Ian Kent8d7b48e2008-10-15 22:02:54 -0700416 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 */
428static 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;
Al Viro4e44b682009-04-07 11:08:56 -0400433 struct path path;
Ian Kent8d7b48e2008-10-15 22:02:54 -0700434 dev_t devid;
435 int err = -ENOENT;
436
437 if (param->size <= sizeof(*param)) {
438 err = -EINVAL;
439 goto out;
440 }
441
Al Viro4e44b682009-04-07 11:08:56 -0400442 devid = sbi->sb->s_dev;
Ian Kent8d7b48e2008-10-15 22:02:54 -0700443
Ian Kent730c9ee2009-01-06 14:42:06 -0800444 param->requester.uid = param->requester.gid = -1;
Ian Kent8d7b48e2008-10-15 22:02:54 -0700445
Al Viro4e44b682009-04-07 11:08:56 -0400446 err = find_autofs_mount(param->path, &path, test_by_dev, &devid);
Ian Kent8d7b48e2008-10-15 22:02:54 -0700447 if (err)
448 goto out;
449
Al Viro4e44b682009-04-07 11:08:56 -0400450 ino = autofs4_dentry_ino(path.dentry);
Ian Kent8d7b48e2008-10-15 22:02:54 -0700451 if (ino) {
452 err = 0;
NeilBrown23bfc2a2014-10-13 15:52:14 -0700453 autofs4_expire_wait(path.dentry, 0);
Ian Kent8d7b48e2008-10-15 22:02:54 -0700454 spin_lock(&sbi->fs_lock);
Eric W. Biederman45634cd2012-02-07 16:18:52 -0800455 param->requester.uid = from_kuid_munged(current_user_ns(), ino->uid);
456 param->requester.gid = from_kgid_munged(current_user_ns(), ino->gid);
Ian Kent8d7b48e2008-10-15 22:02:54 -0700457 spin_unlock(&sbi->fs_lock);
458 }
Al Viro4e44b682009-04-07 11:08:56 -0400459 path_put(&path);
Ian Kent8d7b48e2008-10-15 22:02:54 -0700460out:
461 return err;
462}
463
464/*
465 * Call repeatedly until it returns -EAGAIN, meaning there's nothing
466 * more that can be done.
467 */
468static int autofs_dev_ioctl_expire(struct file *fp,
469 struct autofs_sb_info *sbi,
470 struct autofs_dev_ioctl *param)
471{
Ian Kent8d7b48e2008-10-15 22:02:54 -0700472 struct vfsmount *mnt;
Ian Kent8d7b48e2008-10-15 22:02:54 -0700473 int how;
474
Ian Kent730c9ee2009-01-06 14:42:06 -0800475 how = param->expire.how;
Ian Kent8d7b48e2008-10-15 22:02:54 -0700476 mnt = fp->f_path.mnt;
477
Ian Kent56fcef72009-03-31 15:24:43 -0700478 return autofs4_do_expire_multi(sbi->sb, mnt, sbi, how);
Ian Kent8d7b48e2008-10-15 22:02:54 -0700479}
480
481/* Check if autofs mount point is in use */
482static int autofs_dev_ioctl_askumount(struct file *fp,
483 struct autofs_sb_info *sbi,
484 struct autofs_dev_ioctl *param)
485{
Ian Kent730c9ee2009-01-06 14:42:06 -0800486 param->askumount.may_umount = 0;
Ian Kent8d7b48e2008-10-15 22:02:54 -0700487 if (may_umount(fp->f_path.mnt))
Ian Kent730c9ee2009-01-06 14:42:06 -0800488 param->askumount.may_umount = 1;
Ian Kent8d7b48e2008-10-15 22:02:54 -0700489 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
Ian Kentac838712013-09-08 16:47:23 +0800504 * 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.
Ian Kent8d7b48e2008-10-15 22:02:54 -0700509 *
510 * In both cases the the device number (as returned by
511 * new_encode_dev()) is also returned.
512 */
513static int autofs_dev_ioctl_ismountpoint(struct file *fp,
514 struct autofs_sb_info *sbi,
515 struct autofs_dev_ioctl *param)
516{
Al Viro4e44b682009-04-07 11:08:56 -0400517 struct path path;
518 const char *name;
Ian Kent8d7b48e2008-10-15 22:02:54 -0700519 unsigned int type;
Ian Kent730c9ee2009-01-06 14:42:06 -0800520 unsigned int devid, magic;
Ian Kent8d7b48e2008-10-15 22:02:54 -0700521 int err = -ENOENT;
522
523 if (param->size <= sizeof(*param)) {
524 err = -EINVAL;
525 goto out;
526 }
527
Al Viro4e44b682009-04-07 11:08:56 -0400528 name = param->path;
Ian Kent730c9ee2009-01-06 14:42:06 -0800529 type = param->ismountpoint.in.type;
Ian Kent8d7b48e2008-10-15 22:02:54 -0700530
Ian Kent730c9ee2009-01-06 14:42:06 -0800531 param->ismountpoint.out.devid = devid = 0;
532 param->ismountpoint.out.magic = magic = 0;
Ian Kent8d7b48e2008-10-15 22:02:54 -0700533
534 if (!fp || param->ioctlfd == -1) {
Al Viro4e44b682009-04-07 11:08:56 -0400535 if (autofs_type_any(type))
Ian Kentac838712013-09-08 16:47:23 +0800536 err = kern_path_mountpoint(AT_FDCWD,
537 name, &path, LOOKUP_FOLLOW);
Al Viro4e44b682009-04-07 11:08:56 -0400538 else
Ian Kentac838712013-09-08 16:47:23 +0800539 err = find_autofs_mount(name, &path,
540 test_by_type, &type);
Al Viro4e44b682009-04-07 11:08:56 -0400541 if (err)
542 goto out;
Al Virod8c95842011-12-07 18:16:57 -0500543 devid = new_encode_dev(path.dentry->d_sb->s_dev);
Ian Kent8d7b48e2008-10-15 22:02:54 -0700544 err = 0;
Al Virof598f9f2010-01-23 20:08:53 -0500545 if (path.mnt->mnt_root == path.dentry) {
Ian Kent8d7b48e2008-10-15 22:02:54 -0700546 err = 1;
Al Virod8c95842011-12-07 18:16:57 -0500547 magic = path.dentry->d_sb->s_magic;
Ian Kent8d7b48e2008-10-15 22:02:54 -0700548 }
549 } else {
Al Viro4e44b682009-04-07 11:08:56 -0400550 dev_t dev = sbi->sb->s_dev;
Ian Kent8d7b48e2008-10-15 22:02:54 -0700551
Al Viro4e44b682009-04-07 11:08:56 -0400552 err = find_autofs_mount(name, &path, test_by_dev, &dev);
Ian Kent8d7b48e2008-10-15 22:02:54 -0700553 if (err)
554 goto out;
555
Al Viro4e44b682009-04-07 11:08:56 -0400556 devid = new_encode_dev(dev);
Ian Kent8d7b48e2008-10-15 22:02:54 -0700557
Al Viro4e44b682009-04-07 11:08:56 -0400558 err = have_submounts(path.dentry);
Ian Kent8d7b48e2008-10-15 22:02:54 -0700559
David Howellscc53ce52011-01-14 18:45:26 +0000560 if (follow_down_one(&path))
Al Virod8c95842011-12-07 18:16:57 -0500561 magic = path.dentry->d_sb->s_magic;
Ian Kent8d7b48e2008-10-15 22:02:54 -0700562 }
563
Ian Kent730c9ee2009-01-06 14:42:06 -0800564 param->ismountpoint.out.devid = devid;
565 param->ismountpoint.out.magic = magic;
Al Viro4e44b682009-04-07 11:08:56 -0400566 path_put(&path);
Ian Kent8d7b48e2008-10-15 22:02:54 -0700567out:
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
578static 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 */
618static 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
Ian Kent8d7b48e2008-10-15 22:02:54 -0700676 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 }
694cont:
695 err = fn(fp, sbi, param);
696
697 if (fp)
698 fput(fp);
699done:
700 if (err >= 0 && copy_to_user(user, param, AUTOFS_DEV_IOCTL_SIZE))
701 err = -EFAULT;
702out:
703 free_dev_ioctl(param);
704 return err;
705}
706
707static 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
715static 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
723static const struct file_operations _dev_ioctl_fops = {
724 .unlocked_ioctl = autofs_dev_ioctl,
725 .compat_ioctl = autofs_dev_ioctl_compat,
726 .owner = THIS_MODULE,
Arnd Bergmann6038f372010-08-15 18:52:59 +0200727 .llseek = noop_llseek,
Ian Kent8d7b48e2008-10-15 22:02:54 -0700728};
729
730static struct miscdevice _autofs_dev_ioctl_misc = {
Kay Sievers578454f2010-05-20 18:07:20 +0200731 .minor = AUTOFS_MINOR,
Ian Kent8d7b48e2008-10-15 22:02:54 -0700732 .name = AUTOFS_DEVICE_NAME,
733 .fops = &_dev_ioctl_fops
734};
735
Kay Sievers578454f2010-05-20 18:07:20 +0200736MODULE_ALIAS_MISCDEV(AUTOFS_MINOR);
737MODULE_ALIAS("devname:autofs");
738
Ian Kent8d7b48e2008-10-15 22:02:54 -0700739/* Register/deregister misc character device */
Fabian Frederick3ff6db32014-06-04 16:12:21 -0700740int __init autofs_dev_ioctl_init(void)
Ian Kent8d7b48e2008-10-15 22:02:54 -0700741{
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
753void autofs_dev_ioctl_exit(void)
754{
755 misc_deregister(&_autofs_dev_ioctl_misc);
756 return;
757}
758