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-rw-r--r--fs/autofs4/dev-ioctl.c863
1 files changed, 863 insertions, 0 deletions
diff --git a/fs/autofs4/dev-ioctl.c b/fs/autofs4/dev-ioctl.c
new file mode 100644
index 000000000000..625abf5422e2
--- /dev/null
+++ b/fs/autofs4/dev-ioctl.c
@@ -0,0 +1,863 @@
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>
22#include <linux/smp_lock.h>
23#include <linux/magic.h>
24#include <linux/dcache.h>
25#include <linux/uaccess.h>
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
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 */
57static int invalid_str(char *str, void *end)
58{
59 while ((void *) str <= end)
60 if (!*str++)
61 return 0;
62 return -EINVAL;
63}
64
65/*
66 * Check that the user compiled against correct version of autofs
67 * misc device code.
68 *
69 * As well as checking the version compatibility this always copies
70 * the kernel interface version out.
71 */
72static int check_dev_ioctl_version(int cmd, struct autofs_dev_ioctl *param)
73{
74 int err = 0;
75
76 if ((AUTOFS_DEV_IOCTL_VERSION_MAJOR != param->ver_major) ||
77 (AUTOFS_DEV_IOCTL_VERSION_MINOR < param->ver_minor)) {
78 AUTOFS_WARN("ioctl control interface version mismatch: "
79 "kernel(%u.%u), user(%u.%u), cmd(%d)",
80 AUTOFS_DEV_IOCTL_VERSION_MAJOR,
81 AUTOFS_DEV_IOCTL_VERSION_MINOR,
82 param->ver_major, param->ver_minor, cmd);
83 err = -EINVAL;
84 }
85
86 /* Fill in the kernel version. */
87 param->ver_major = AUTOFS_DEV_IOCTL_VERSION_MAJOR;
88 param->ver_minor = AUTOFS_DEV_IOCTL_VERSION_MINOR;
89
90 return err;
91}
92
93/*
94 * Copy parameter control struct, including a possible path allocated
95 * at the end of the struct.
96 */
97static struct autofs_dev_ioctl *copy_dev_ioctl(struct autofs_dev_ioctl __user *in)
98{
99 struct autofs_dev_ioctl tmp, *ads;
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
107 ads = kmalloc(tmp.size, GFP_KERNEL);
108 if (!ads)
109 return ERR_PTR(-ENOMEM);
110
111 if (copy_from_user(ads, in, tmp.size)) {
112 kfree(ads);
113 return ERR_PTR(-EFAULT);
114 }
115
116 return ads;
117}
118
119static inline void free_dev_ioctl(struct autofs_dev_ioctl *param)
120{
121 kfree(param);
122 return;
123}
124
125/*
126 * Check sanity of parameter control fields and if a path is present
127 * check that it has a "/" and is terminated.
128 */
129static int validate_dev_ioctl(int cmd, struct autofs_dev_ioctl *param)
130{
131 int err = -EINVAL;
132
133 if (check_dev_ioctl_version(cmd, param)) {
134 AUTOFS_WARN("invalid device control module version "
135 "supplied for cmd(0x%08x)", cmd);
136 goto out;
137 }
138
139 if (param->size > sizeof(*param)) {
140 err = check_name(param->path);
141 if (err) {
142 AUTOFS_WARN("invalid path supplied for cmd(0x%08x)",
143 cmd);
144 goto out;
145 }
146
147 err = invalid_str(param->path,
148 (void *) ((size_t) param + param->size));
149 if (err) {
150 AUTOFS_WARN("invalid path supplied for cmd(0x%08x)",
151 cmd);
152 goto out;
153 }
154 }
155
156 err = 0;
157out:
158 return err;
159}
160
161/*
162 * Get the autofs super block info struct from the file opened on
163 * the autofs mount point.
164 */
165static struct autofs_sb_info *autofs_dev_ioctl_sbi(struct file *f)
166{
167 struct autofs_sb_info *sbi = NULL;
168 struct inode *inode;
169
170 if (f) {
171 inode = f->f_path.dentry->d_inode;
172 sbi = autofs4_sbi(inode->i_sb);
173 }
174 return sbi;
175}
176
177/* Return autofs module protocol version */
178static int autofs_dev_ioctl_protover(struct file *fp,
179 struct autofs_sb_info *sbi,
180 struct autofs_dev_ioctl *param)
181{
182 param->arg1 = sbi->version;
183 return 0;
184}
185
186/* Return autofs module protocol sub version */
187static int autofs_dev_ioctl_protosubver(struct file *fp,
188 struct autofs_sb_info *sbi,
189 struct autofs_dev_ioctl *param)
190{
191 param->arg1 = sbi->sub_version;
192 return 0;
193}
194
195/*
196 * Walk down the mount stack looking for an autofs mount that
197 * has the requested device number (aka. new_encode_dev(sb->s_dev).
198 */
199static int autofs_dev_ioctl_find_super(struct nameidata *nd, dev_t devno)
200{
201 struct dentry *dentry;
202 struct inode *inode;
203 struct super_block *sb;
204 dev_t s_dev;
205 unsigned int err;
206
207 err = -ENOENT;
208
209 /* Lookup the dentry name at the base of our mount point */
210 dentry = d_lookup(nd->path.dentry, &nd->last);
211 if (!dentry)
212 goto out;
213
214 dput(nd->path.dentry);
215 nd->path.dentry = dentry;
216
217 /* And follow the mount stack looking for our autofs mount */
218 while (follow_down(&nd->path.mnt, &nd->path.dentry)) {
219 inode = nd->path.dentry->d_inode;
220 if (!inode)
221 break;
222
223 sb = inode->i_sb;
224 s_dev = new_encode_dev(sb->s_dev);
225 if (devno == s_dev) {
226 if (sb->s_magic == AUTOFS_SUPER_MAGIC) {
227 err = 0;
228 break;
229 }
230 }
231 }
232out:
233 return err;
234}
235
236/*
237 * Walk down the mount stack looking for an autofs mount that
238 * has the requested mount type (ie. indirect, direct or offset).
239 */
240static int autofs_dev_ioctl_find_sbi_type(struct nameidata *nd, unsigned int type)
241{
242 struct dentry *dentry;
243 struct autofs_info *ino;
244 unsigned int err;
245
246 err = -ENOENT;
247
248 /* Lookup the dentry name at the base of our mount point */
249 dentry = d_lookup(nd->path.dentry, &nd->last);
250 if (!dentry)
251 goto out;
252
253 dput(nd->path.dentry);
254 nd->path.dentry = dentry;
255
256 /* And follow the mount stack looking for our autofs mount */
257 while (follow_down(&nd->path.mnt, &nd->path.dentry)) {
258 ino = autofs4_dentry_ino(nd->path.dentry);
259 if (ino && ino->sbi->type & type) {
260 err = 0;
261 break;
262 }
263 }
264out:
265 return err;
266}
267
268static void autofs_dev_ioctl_fd_install(unsigned int fd, struct file *file)
269{
270 struct files_struct *files = current->files;
271 struct fdtable *fdt;
272
273 spin_lock(&files->file_lock);
274 fdt = files_fdtable(files);
275 BUG_ON(fdt->fd[fd] != NULL);
276 rcu_assign_pointer(fdt->fd[fd], file);
277 FD_SET(fd, fdt->close_on_exec);
278 spin_unlock(&files->file_lock);
279}
280
281
282/*
283 * Open a file descriptor on the autofs mount point corresponding
284 * to the given path and device number (aka. new_encode_dev(sb->s_dev)).
285 */
286static int autofs_dev_ioctl_open_mountpoint(const char *path, dev_t devid)
287{
288 struct file *filp;
289 struct nameidata nd;
290 int err, fd;
291
292 fd = get_unused_fd();
293 if (likely(fd >= 0)) {
294 /* Get nameidata of the parent directory */
295 err = path_lookup(path, LOOKUP_PARENT, &nd);
296 if (err)
297 goto out;
298
299 /*
300 * Search down, within the parent, looking for an
301 * autofs super block that has the device number
302 * corresponding to the autofs fs we want to open.
303 */
304 err = autofs_dev_ioctl_find_super(&nd, devid);
305 if (err) {
306 path_put(&nd.path);
307 goto out;
308 }
309
310 filp = dentry_open(nd.path.dentry, nd.path.mnt, O_RDONLY);
311 if (IS_ERR(filp)) {
312 err = PTR_ERR(filp);
313 goto out;
314 }
315
316 autofs_dev_ioctl_fd_install(fd, filp);
317 }
318
319 return fd;
320
321out:
322 put_unused_fd(fd);
323 return err;
324}
325
326/* Open a file descriptor on an autofs mount point */
327static int autofs_dev_ioctl_openmount(struct file *fp,
328 struct autofs_sb_info *sbi,
329 struct autofs_dev_ioctl *param)
330{
331 const char *path;
332 dev_t devid;
333 int err, fd;
334
335 /* param->path has already been checked */
336 if (!param->arg1)
337 return -EINVAL;
338
339 param->ioctlfd = -1;
340
341 path = param->path;
342 devid = param->arg1;
343
344 err = 0;
345 fd = autofs_dev_ioctl_open_mountpoint(path, devid);
346 if (unlikely(fd < 0)) {
347 err = fd;
348 goto out;
349 }
350
351 param->ioctlfd = fd;
352out:
353 return err;
354}
355
356/* Close file descriptor allocated above (user can also use close(2)). */
357static int autofs_dev_ioctl_closemount(struct file *fp,
358 struct autofs_sb_info *sbi,
359 struct autofs_dev_ioctl *param)
360{
361 return sys_close(param->ioctlfd);
362}
363
364/*
365 * Send "ready" status for an existing wait (either a mount or an expire
366 * request).
367 */
368static int autofs_dev_ioctl_ready(struct file *fp,
369 struct autofs_sb_info *sbi,
370 struct autofs_dev_ioctl *param)
371{
372 autofs_wqt_t token;
373
374 token = (autofs_wqt_t) param->arg1;
375 return autofs4_wait_release(sbi, token, 0);
376}
377
378/*
379 * Send "fail" status for an existing wait (either a mount or an expire
380 * request).
381 */
382static int autofs_dev_ioctl_fail(struct file *fp,
383 struct autofs_sb_info *sbi,
384 struct autofs_dev_ioctl *param)
385{
386 autofs_wqt_t token;
387 int status;
388
389 token = (autofs_wqt_t) param->arg1;
390 status = param->arg2 ? param->arg2 : -ENOENT;
391 return autofs4_wait_release(sbi, token, status);
392}
393
394/*
395 * Set the pipe fd for kernel communication to the daemon.
396 *
397 * Normally this is set at mount using an option but if we
398 * are reconnecting to a busy mount then we need to use this
399 * to tell the autofs mount about the new kernel pipe fd. In
400 * order to protect mounts against incorrectly setting the
401 * pipefd we also require that the autofs mount be catatonic.
402 *
403 * This also sets the process group id used to identify the
404 * controlling process (eg. the owning automount(8) daemon).
405 */
406static int autofs_dev_ioctl_setpipefd(struct file *fp,
407 struct autofs_sb_info *sbi,
408 struct autofs_dev_ioctl *param)
409{
410 int pipefd;
411 int err = 0;
412
413 if (param->arg1 == -1)
414 return -EINVAL;
415
416 pipefd = param->arg1;
417
418 mutex_lock(&sbi->wq_mutex);
419 if (!sbi->catatonic) {
420 mutex_unlock(&sbi->wq_mutex);
421 return -EBUSY;
422 } else {
423 struct file *pipe = fget(pipefd);
424 if (!pipe->f_op || !pipe->f_op->write) {
425 err = -EPIPE;
426 fput(pipe);
427 goto out;
428 }
429 sbi->oz_pgrp = task_pgrp_nr(current);
430 sbi->pipefd = pipefd;
431 sbi->pipe = pipe;
432 sbi->catatonic = 0;
433 }
434out:
435 mutex_unlock(&sbi->wq_mutex);
436 return err;
437}
438
439/*
440 * Make the autofs mount point catatonic, no longer responsive to
441 * mount requests. Also closes the kernel pipe file descriptor.
442 */
443static int autofs_dev_ioctl_catatonic(struct file *fp,
444 struct autofs_sb_info *sbi,
445 struct autofs_dev_ioctl *param)
446{
447 autofs4_catatonic_mode(sbi);
448 return 0;
449}
450
451/* Set the autofs mount timeout */
452static int autofs_dev_ioctl_timeout(struct file *fp,
453 struct autofs_sb_info *sbi,
454 struct autofs_dev_ioctl *param)
455{
456 unsigned long timeout;
457
458 timeout = param->arg1;
459 param->arg1 = sbi->exp_timeout / HZ;
460 sbi->exp_timeout = timeout * HZ;
461 return 0;
462}
463
464/*
465 * Return the uid and gid of the last request for the mount
466 *
467 * When reconstructing an autofs mount tree with active mounts
468 * we need to re-connect to mounts that may have used the original
469 * process uid and gid (or string variations of them) for mount
470 * lookups within the map entry.
471 */
472static int autofs_dev_ioctl_requester(struct file *fp,
473 struct autofs_sb_info *sbi,
474 struct autofs_dev_ioctl *param)
475{
476 struct autofs_info *ino;
477 struct nameidata nd;
478 const char *path;
479 dev_t devid;
480 int err = -ENOENT;
481
482 if (param->size <= sizeof(*param)) {
483 err = -EINVAL;
484 goto out;
485 }
486
487 path = param->path;
488 devid = sbi->sb->s_dev;
489
490 param->arg1 = param->arg2 = -1;
491
492 /* Get nameidata of the parent directory */
493 err = path_lookup(path, LOOKUP_PARENT, &nd);
494 if (err)
495 goto out;
496
497 err = autofs_dev_ioctl_find_super(&nd, devid);
498 if (err)
499 goto out_release;
500
501 ino = autofs4_dentry_ino(nd.path.dentry);
502 if (ino) {
503 err = 0;
504 autofs4_expire_wait(nd.path.dentry);
505 spin_lock(&sbi->fs_lock);
506 param->arg1 = ino->uid;
507 param->arg2 = ino->gid;
508 spin_unlock(&sbi->fs_lock);
509 }
510
511out_release:
512 path_put(&nd.path);
513out:
514 return err;
515}
516
517/*
518 * Call repeatedly until it returns -EAGAIN, meaning there's nothing
519 * more that can be done.
520 */
521static int autofs_dev_ioctl_expire(struct file *fp,
522 struct autofs_sb_info *sbi,
523 struct autofs_dev_ioctl *param)
524{
525 struct dentry *dentry;
526 struct vfsmount *mnt;
527 int err = -EAGAIN;
528 int how;
529
530 how = param->arg1;
531 mnt = fp->f_path.mnt;
532
533 if (sbi->type & AUTOFS_TYPE_TRIGGER)
534 dentry = autofs4_expire_direct(sbi->sb, mnt, sbi, how);
535 else
536 dentry = autofs4_expire_indirect(sbi->sb, mnt, sbi, how);
537
538 if (dentry) {
539 struct autofs_info *ino = autofs4_dentry_ino(dentry);
540
541 /*
542 * This is synchronous because it makes the daemon a
543 * little easier
544 */
545 err = autofs4_wait(sbi, dentry, NFY_EXPIRE);
546
547 spin_lock(&sbi->fs_lock);
548 if (ino->flags & AUTOFS_INF_MOUNTPOINT) {
549 ino->flags &= ~AUTOFS_INF_MOUNTPOINT;
550 sbi->sb->s_root->d_mounted++;
551 }
552 ino->flags &= ~AUTOFS_INF_EXPIRING;
553 complete_all(&ino->expire_complete);
554 spin_unlock(&sbi->fs_lock);
555 dput(dentry);
556 }
557
558 return err;
559}
560
561/* Check if autofs mount point is in use */
562static int autofs_dev_ioctl_askumount(struct file *fp,
563 struct autofs_sb_info *sbi,
564 struct autofs_dev_ioctl *param)
565{
566 param->arg1 = 0;
567 if (may_umount(fp->f_path.mnt))
568 param->arg1 = 1;
569 return 0;
570}
571
572/*
573 * Check if the given path is a mountpoint.
574 *
575 * If we are supplied with the file descriptor of an autofs
576 * mount we're looking for a specific mount. In this case
577 * the path is considered a mountpoint if it is itself a
578 * mountpoint or contains a mount, such as a multi-mount
579 * without a root mount. In this case we return 1 if the
580 * path is a mount point and the super magic of the covering
581 * mount if there is one or 0 if it isn't a mountpoint.
582 *
583 * If we aren't supplied with a file descriptor then we
584 * lookup the nameidata of the path and check if it is the
585 * root of a mount. If a type is given we are looking for
586 * a particular autofs mount and if we don't find a match
587 * we return fail. If the located nameidata path is the
588 * root of a mount we return 1 along with the super magic
589 * of the mount or 0 otherwise.
590 *
591 * In both cases the the device number (as returned by
592 * new_encode_dev()) is also returned.
593 */
594static int autofs_dev_ioctl_ismountpoint(struct file *fp,
595 struct autofs_sb_info *sbi,
596 struct autofs_dev_ioctl *param)
597{
598 struct nameidata nd;
599 const char *path;
600 unsigned int type;
601 int err = -ENOENT;
602
603 if (param->size <= sizeof(*param)) {
604 err = -EINVAL;
605 goto out;
606 }
607
608 path = param->path;
609 type = param->arg1;
610
611 param->arg1 = 0;
612 param->arg2 = 0;
613
614 if (!fp || param->ioctlfd == -1) {
615 if (type == AUTOFS_TYPE_ANY) {
616 struct super_block *sb;
617
618 err = path_lookup(path, LOOKUP_FOLLOW, &nd);
619 if (err)
620 goto out;
621
622 sb = nd.path.dentry->d_sb;
623 param->arg1 = new_encode_dev(sb->s_dev);
624 } else {
625 struct autofs_info *ino;
626
627 err = path_lookup(path, LOOKUP_PARENT, &nd);
628 if (err)
629 goto out;
630
631 err = autofs_dev_ioctl_find_sbi_type(&nd, type);
632 if (err)
633 goto out_release;
634
635 ino = autofs4_dentry_ino(nd.path.dentry);
636 param->arg1 = autofs4_get_dev(ino->sbi);
637 }
638
639 err = 0;
640 if (nd.path.dentry->d_inode &&
641 nd.path.mnt->mnt_root == nd.path.dentry) {
642 err = 1;
643 param->arg2 = nd.path.dentry->d_inode->i_sb->s_magic;
644 }
645 } else {
646 dev_t devid = new_encode_dev(sbi->sb->s_dev);
647
648 err = path_lookup(path, LOOKUP_PARENT, &nd);
649 if (err)
650 goto out;
651
652 err = autofs_dev_ioctl_find_super(&nd, devid);
653 if (err)
654 goto out_release;
655
656 param->arg1 = autofs4_get_dev(sbi);
657
658 err = have_submounts(nd.path.dentry);
659
660 if (nd.path.mnt->mnt_mountpoint != nd.path.mnt->mnt_root) {
661 if (follow_down(&nd.path.mnt, &nd.path.dentry)) {
662 struct inode *inode = nd.path.dentry->d_inode;
663 param->arg2 = inode->i_sb->s_magic;
664 }
665 }
666 }
667
668out_release:
669 path_put(&nd.path);
670out:
671 return err;
672}
673
674/*
675 * Our range of ioctl numbers isn't 0 based so we need to shift
676 * the array index by _IOC_NR(AUTOFS_CTL_IOC_FIRST) for the table
677 * lookup.
678 */
679#define cmd_idx(cmd) (cmd - _IOC_NR(AUTOFS_DEV_IOCTL_IOC_FIRST))
680
681static ioctl_fn lookup_dev_ioctl(unsigned int cmd)
682{
683 static struct {
684 int cmd;
685 ioctl_fn fn;
686 } _ioctls[] = {
687 {cmd_idx(AUTOFS_DEV_IOCTL_VERSION_CMD), NULL},
688 {cmd_idx(AUTOFS_DEV_IOCTL_PROTOVER_CMD),
689 autofs_dev_ioctl_protover},
690 {cmd_idx(AUTOFS_DEV_IOCTL_PROTOSUBVER_CMD),
691 autofs_dev_ioctl_protosubver},
692 {cmd_idx(AUTOFS_DEV_IOCTL_OPENMOUNT_CMD),
693 autofs_dev_ioctl_openmount},
694 {cmd_idx(AUTOFS_DEV_IOCTL_CLOSEMOUNT_CMD),
695 autofs_dev_ioctl_closemount},
696 {cmd_idx(AUTOFS_DEV_IOCTL_READY_CMD),
697 autofs_dev_ioctl_ready},
698 {cmd_idx(AUTOFS_DEV_IOCTL_FAIL_CMD),
699 autofs_dev_ioctl_fail},
700 {cmd_idx(AUTOFS_DEV_IOCTL_SETPIPEFD_CMD),
701 autofs_dev_ioctl_setpipefd},
702 {cmd_idx(AUTOFS_DEV_IOCTL_CATATONIC_CMD),
703 autofs_dev_ioctl_catatonic},
704 {cmd_idx(AUTOFS_DEV_IOCTL_TIMEOUT_CMD),
705 autofs_dev_ioctl_timeout},
706 {cmd_idx(AUTOFS_DEV_IOCTL_REQUESTER_CMD),
707 autofs_dev_ioctl_requester},
708 {cmd_idx(AUTOFS_DEV_IOCTL_EXPIRE_CMD),
709 autofs_dev_ioctl_expire},
710 {cmd_idx(AUTOFS_DEV_IOCTL_ASKUMOUNT_CMD),
711 autofs_dev_ioctl_askumount},
712 {cmd_idx(AUTOFS_DEV_IOCTL_ISMOUNTPOINT_CMD),
713 autofs_dev_ioctl_ismountpoint}
714 };
715 unsigned int idx = cmd_idx(cmd);
716
717 return (idx >= ARRAY_SIZE(_ioctls)) ? NULL : _ioctls[idx].fn;
718}
719
720/* ioctl dispatcher */
721static int _autofs_dev_ioctl(unsigned int command, struct autofs_dev_ioctl __user *user)
722{
723 struct autofs_dev_ioctl *param;
724 struct file *fp;
725 struct autofs_sb_info *sbi;
726 unsigned int cmd_first, cmd;
727 ioctl_fn fn = NULL;
728 int err = 0;
729
730 /* only root can play with this */
731 if (!capable(CAP_SYS_ADMIN))
732 return -EPERM;
733
734 cmd_first = _IOC_NR(AUTOFS_DEV_IOCTL_IOC_FIRST);
735 cmd = _IOC_NR(command);
736
737 if (_IOC_TYPE(command) != _IOC_TYPE(AUTOFS_DEV_IOCTL_IOC_FIRST) ||
738 cmd - cmd_first >= AUTOFS_DEV_IOCTL_IOC_COUNT) {
739 return -ENOTTY;
740 }
741
742 /* Copy the parameters into kernel space. */
743 param = copy_dev_ioctl(user);
744 if (IS_ERR(param))
745 return PTR_ERR(param);
746
747 err = validate_dev_ioctl(command, param);
748 if (err)
749 goto out;
750
751 /* The validate routine above always sets the version */
752 if (cmd == AUTOFS_DEV_IOCTL_VERSION_CMD)
753 goto done;
754
755 fn = lookup_dev_ioctl(cmd);
756 if (!fn) {
757 AUTOFS_WARN("unknown command 0x%08x", command);
758 return -ENOTTY;
759 }
760
761 fp = NULL;
762 sbi = NULL;
763
764 /*
765 * For obvious reasons the openmount can't have a file
766 * descriptor yet. We don't take a reference to the
767 * file during close to allow for immediate release.
768 */
769 if (cmd != AUTOFS_DEV_IOCTL_OPENMOUNT_CMD &&
770 cmd != AUTOFS_DEV_IOCTL_CLOSEMOUNT_CMD) {
771 fp = fget(param->ioctlfd);
772 if (!fp) {
773 if (cmd == AUTOFS_DEV_IOCTL_ISMOUNTPOINT_CMD)
774 goto cont;
775 err = -EBADF;
776 goto out;
777 }
778
779 if (!fp->f_op) {
780 err = -ENOTTY;
781 fput(fp);
782 goto out;
783 }
784
785 sbi = autofs_dev_ioctl_sbi(fp);
786 if (!sbi || sbi->magic != AUTOFS_SBI_MAGIC) {
787 err = -EINVAL;
788 fput(fp);
789 goto out;
790 }
791
792 /*
793 * Admin needs to be able to set the mount catatonic in
794 * order to be able to perform the re-open.
795 */
796 if (!autofs4_oz_mode(sbi) &&
797 cmd != AUTOFS_DEV_IOCTL_CATATONIC_CMD) {
798 err = -EACCES;
799 fput(fp);
800 goto out;
801 }
802 }
803cont:
804 err = fn(fp, sbi, param);
805
806 if (fp)
807 fput(fp);
808done:
809 if (err >= 0 && copy_to_user(user, param, AUTOFS_DEV_IOCTL_SIZE))
810 err = -EFAULT;
811out:
812 free_dev_ioctl(param);
813 return err;
814}
815
816static long autofs_dev_ioctl(struct file *file, uint command, ulong u)
817{
818 int err;
819 err = _autofs_dev_ioctl(command, (struct autofs_dev_ioctl __user *) u);
820 return (long) err;
821}
822
823#ifdef CONFIG_COMPAT
824static long autofs_dev_ioctl_compat(struct file *file, uint command, ulong u)
825{
826 return (long) autofs_dev_ioctl(file, command, (ulong) compat_ptr(u));
827}
828#else
829#define autofs_dev_ioctl_compat NULL
830#endif
831
832static const struct file_operations _dev_ioctl_fops = {
833 .unlocked_ioctl = autofs_dev_ioctl,
834 .compat_ioctl = autofs_dev_ioctl_compat,
835 .owner = THIS_MODULE,
836};
837
838static struct miscdevice _autofs_dev_ioctl_misc = {
839 .minor = MISC_DYNAMIC_MINOR,
840 .name = AUTOFS_DEVICE_NAME,
841 .fops = &_dev_ioctl_fops
842};
843
844/* Register/deregister misc character device */
845int autofs_dev_ioctl_init(void)
846{
847 int r;
848
849 r = misc_register(&_autofs_dev_ioctl_misc);
850 if (r) {
851 AUTOFS_ERROR("misc_register failed for control device");
852 return r;
853 }
854
855 return 0;
856}
857
858void autofs_dev_ioctl_exit(void)
859{
860 misc_deregister(&_autofs_dev_ioctl_misc);
861 return;
862}
863
generated by cgit v1.2.2 (git 2.25.0) at 2024-11-27 16:51:54 -0500