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30#include <linux/module.h>
31#include <linux/fs.h>
32#include <linux/mount.h>
33#include <linux/pagemap.h>
34#include <linux/init.h>
35#include <linux/proc_fs.h>
36#include <linux/usb.h>
37#include <linux/namei.h>
38#include <linux/usbdevice_fs.h>
39#include <linux/parser.h>
40#include <linux/notifier.h>
41#include <linux/seq_file.h>
42#include <linux/usb/hcd.h>
43#include <asm/byteorder.h>
44#include "usb.h"
45
46#define USBFS_DEFAULT_DEVMODE (S_IWUSR | S_IRUGO)
47#define USBFS_DEFAULT_BUSMODE (S_IXUGO | S_IRUGO)
48#define USBFS_DEFAULT_LISTMODE S_IRUGO
49
50static const struct file_operations default_file_operations;
51static struct vfsmount *usbfs_mount;
52static int usbfs_mount_count;
53
54static struct dentry *devices_usbfs_dentry;
55static int num_buses;
56
57static uid_t devuid;
58static uid_t busuid;
59static uid_t listuid;
60static gid_t devgid;
61static gid_t busgid;
62static gid_t listgid;
63static umode_t devmode = USBFS_DEFAULT_DEVMODE;
64static umode_t busmode = USBFS_DEFAULT_BUSMODE;
65static umode_t listmode = USBFS_DEFAULT_LISTMODE;
66
67static int usbfs_show_options(struct seq_file *seq, struct dentry *root)
68{
69 if (devuid != 0)
70 seq_printf(seq, ",devuid=%u", devuid);
71 if (devgid != 0)
72 seq_printf(seq, ",devgid=%u", devgid);
73 if (devmode != USBFS_DEFAULT_DEVMODE)
74 seq_printf(seq, ",devmode=%o", devmode);
75 if (busuid != 0)
76 seq_printf(seq, ",busuid=%u", busuid);
77 if (busgid != 0)
78 seq_printf(seq, ",busgid=%u", busgid);
79 if (busmode != USBFS_DEFAULT_BUSMODE)
80 seq_printf(seq, ",busmode=%o", busmode);
81 if (listuid != 0)
82 seq_printf(seq, ",listuid=%u", listuid);
83 if (listgid != 0)
84 seq_printf(seq, ",listgid=%u", listgid);
85 if (listmode != USBFS_DEFAULT_LISTMODE)
86 seq_printf(seq, ",listmode=%o", listmode);
87
88 return 0;
89}
90
91enum {
92 Opt_devuid, Opt_devgid, Opt_devmode,
93 Opt_busuid, Opt_busgid, Opt_busmode,
94 Opt_listuid, Opt_listgid, Opt_listmode,
95 Opt_err,
96};
97
98static const match_table_t tokens = {
99 {Opt_devuid, "devuid=%u"},
100 {Opt_devgid, "devgid=%u"},
101 {Opt_devmode, "devmode=%o"},
102 {Opt_busuid, "busuid=%u"},
103 {Opt_busgid, "busgid=%u"},
104 {Opt_busmode, "busmode=%o"},
105 {Opt_listuid, "listuid=%u"},
106 {Opt_listgid, "listgid=%u"},
107 {Opt_listmode, "listmode=%o"},
108 {Opt_err, NULL}
109};
110
111static int parse_options(struct super_block *s, char *data)
112{
113 char *p;
114 int option;
115
116
117 devuid = 0;
118 busuid = 0;
119 listuid = 0;
120 devgid = 0;
121 busgid = 0;
122 listgid = 0;
123 devmode = USBFS_DEFAULT_DEVMODE;
124 busmode = USBFS_DEFAULT_BUSMODE;
125 listmode = USBFS_DEFAULT_LISTMODE;
126
127 while ((p = strsep(&data, ",")) != NULL) {
128 substring_t args[MAX_OPT_ARGS];
129 int token;
130 if (!*p)
131 continue;
132
133 token = match_token(p, tokens, args);
134 switch (token) {
135 case Opt_devuid:
136 if (match_int(&args[0], &option))
137 return -EINVAL;
138 devuid = option;
139 break;
140 case Opt_devgid:
141 if (match_int(&args[0], &option))
142 return -EINVAL;
143 devgid = option;
144 break;
145 case Opt_devmode:
146 if (match_octal(&args[0], &option))
147 return -EINVAL;
148 devmode = option & S_IRWXUGO;
149 break;
150 case Opt_busuid:
151 if (match_int(&args[0], &option))
152 return -EINVAL;
153 busuid = option;
154 break;
155 case Opt_busgid:
156 if (match_int(&args[0], &option))
157 return -EINVAL;
158 busgid = option;
159 break;
160 case Opt_busmode:
161 if (match_octal(&args[0], &option))
162 return -EINVAL;
163 busmode = option & S_IRWXUGO;
164 break;
165 case Opt_listuid:
166 if (match_int(&args[0], &option))
167 return -EINVAL;
168 listuid = option;
169 break;
170 case Opt_listgid:
171 if (match_int(&args[0], &option))
172 return -EINVAL;
173 listgid = option;
174 break;
175 case Opt_listmode:
176 if (match_octal(&args[0], &option))
177 return -EINVAL;
178 listmode = option & S_IRWXUGO;
179 break;
180 default:
181 printk(KERN_ERR "usbfs: unrecognised mount option "
182 "\"%s\" or missing value\n", p);
183 return -EINVAL;
184 }
185 }
186
187 return 0;
188}
189
190static void update_special(struct dentry *special)
191{
192 special->d_inode->i_uid = listuid;
193 special->d_inode->i_gid = listgid;
194 special->d_inode->i_mode = S_IFREG | listmode;
195}
196
197static void update_dev(struct dentry *dev)
198{
199 dev->d_inode->i_uid = devuid;
200 dev->d_inode->i_gid = devgid;
201 dev->d_inode->i_mode = S_IFREG | devmode;
202}
203
204static void update_bus(struct dentry *bus)
205{
206 struct dentry *dev = NULL;
207
208 bus->d_inode->i_uid = busuid;
209 bus->d_inode->i_gid = busgid;
210 bus->d_inode->i_mode = S_IFDIR | busmode;
211
212 mutex_lock(&bus->d_inode->i_mutex);
213
214 list_for_each_entry(dev, &bus->d_subdirs, d_u.d_child)
215 if (dev->d_inode)
216 update_dev(dev);
217
218 mutex_unlock(&bus->d_inode->i_mutex);
219}
220
221static void update_sb(struct super_block *sb)
222{
223 struct dentry *root = sb->s_root;
224 struct dentry *bus = NULL;
225
226 if (!root)
227 return;
228
229 mutex_lock_nested(&root->d_inode->i_mutex, I_MUTEX_PARENT);
230
231 list_for_each_entry(bus, &root->d_subdirs, d_u.d_child) {
232 if (bus->d_inode) {
233 switch (S_IFMT & bus->d_inode->i_mode) {
234 case S_IFDIR:
235 update_bus(bus);
236 break;
237 case S_IFREG:
238 update_special(bus);
239 break;
240 default:
241 printk(KERN_WARNING "usbfs: Unknown node %s "
242 "mode %x found on remount!\n",
243 bus->d_name.name, bus->d_inode->i_mode);
244 break;
245 }
246 }
247 }
248
249 mutex_unlock(&root->d_inode->i_mutex);
250}
251
252static int remount(struct super_block *sb, int *flags, char *data)
253{
254
255
256
257
258 if (*flags & MS_KERNMOUNT)
259 return 0;
260
261 if (parse_options(sb, data)) {
262 printk(KERN_WARNING "usbfs: mount parameter error.\n");
263 return -EINVAL;
264 }
265
266 if (usbfs_mount)
267 update_sb(usbfs_mount->mnt_sb);
268
269 return 0;
270}
271
272static struct inode *usbfs_get_inode (struct super_block *sb, umode_t mode, dev_t dev)
273{
274 struct inode *inode = new_inode(sb);
275
276 if (inode) {
277 inode->i_ino = get_next_ino();
278 inode_init_owner(inode, NULL, mode);
279 inode->i_atime = inode->i_mtime = inode->i_ctime = CURRENT_TIME;
280 switch (mode & S_IFMT) {
281 default:
282 init_special_inode(inode, mode, dev);
283 break;
284 case S_IFREG:
285 inode->i_fop = &default_file_operations;
286 break;
287 case S_IFDIR:
288 inode->i_op = &simple_dir_inode_operations;
289 inode->i_fop = &simple_dir_operations;
290
291
292 inc_nlink(inode);
293 break;
294 }
295 }
296 return inode;
297}
298
299
300static int usbfs_mknod (struct inode *dir, struct dentry *dentry, umode_t mode,
301 dev_t dev)
302{
303 struct inode *inode = usbfs_get_inode(dir->i_sb, mode, dev);
304 int error = -EPERM;
305
306 if (dentry->d_inode)
307 return -EEXIST;
308
309 if (inode) {
310 d_instantiate(dentry, inode);
311 dget(dentry);
312 error = 0;
313 }
314 return error;
315}
316
317static int usbfs_mkdir (struct inode *dir, struct dentry *dentry, umode_t mode)
318{
319 int res;
320
321 mode = (mode & (S_IRWXUGO | S_ISVTX)) | S_IFDIR;
322 res = usbfs_mknod (dir, dentry, mode, 0);
323 if (!res)
324 inc_nlink(dir);
325 return res;
326}
327
328static int usbfs_create (struct inode *dir, struct dentry *dentry, umode_t mode)
329{
330 mode = (mode & S_IALLUGO) | S_IFREG;
331 return usbfs_mknod (dir, dentry, mode, 0);
332}
333
334static inline int usbfs_positive (struct dentry *dentry)
335{
336 return dentry->d_inode && !d_unhashed(dentry);
337}
338
339static int usbfs_empty (struct dentry *dentry)
340{
341 struct list_head *list;
342
343 spin_lock(&dentry->d_lock);
344 list_for_each(list, &dentry->d_subdirs) {
345 struct dentry *de = list_entry(list, struct dentry, d_u.d_child);
346
347 spin_lock_nested(&de->d_lock, DENTRY_D_LOCK_NESTED);
348 if (usbfs_positive(de)) {
349 spin_unlock(&de->d_lock);
350 spin_unlock(&dentry->d_lock);
351 return 0;
352 }
353 spin_unlock(&de->d_lock);
354 }
355 spin_unlock(&dentry->d_lock);
356 return 1;
357}
358
359static int usbfs_unlink (struct inode *dir, struct dentry *dentry)
360{
361 struct inode *inode = dentry->d_inode;
362 mutex_lock(&inode->i_mutex);
363 drop_nlink(dentry->d_inode);
364 dput(dentry);
365 mutex_unlock(&inode->i_mutex);
366 d_delete(dentry);
367 return 0;
368}
369
370static int usbfs_rmdir(struct inode *dir, struct dentry *dentry)
371{
372 int error = -ENOTEMPTY;
373 struct inode * inode = dentry->d_inode;
374
375 mutex_lock(&inode->i_mutex);
376 dentry_unhash(dentry);
377 if (usbfs_empty(dentry)) {
378 dont_mount(dentry);
379 drop_nlink(dentry->d_inode);
380 drop_nlink(dentry->d_inode);
381 dput(dentry);
382 inode->i_flags |= S_DEAD;
383 drop_nlink(dir);
384 error = 0;
385 }
386 mutex_unlock(&inode->i_mutex);
387 if (!error)
388 d_delete(dentry);
389 return error;
390}
391
392
393
394static ssize_t default_read_file (struct file *file, char __user *buf,
395 size_t count, loff_t *ppos)
396{
397 return 0;
398}
399
400static ssize_t default_write_file (struct file *file, const char __user *buf,
401 size_t count, loff_t *ppos)
402{
403 return count;
404}
405
406static loff_t default_file_lseek (struct file *file, loff_t offset, int orig)
407{
408 loff_t retval = -EINVAL;
409
410 mutex_lock(&file->f_path.dentry->d_inode->i_mutex);
411 switch(orig) {
412 case 0:
413 if (offset > 0) {
414 file->f_pos = offset;
415 retval = file->f_pos;
416 }
417 break;
418 case 1:
419 if ((offset + file->f_pos) > 0) {
420 file->f_pos += offset;
421 retval = file->f_pos;
422 }
423 break;
424 default:
425 break;
426 }
427 mutex_unlock(&file->f_path.dentry->d_inode->i_mutex);
428 return retval;
429}
430
431static const struct file_operations default_file_operations = {
432 .read = default_read_file,
433 .write = default_write_file,
434 .open = simple_open,
435 .llseek = default_file_lseek,
436};
437
438static const struct super_operations usbfs_ops = {
439 .statfs = simple_statfs,
440 .drop_inode = generic_delete_inode,
441 .remount_fs = remount,
442 .show_options = usbfs_show_options,
443};
444
445static int usbfs_fill_super(struct super_block *sb, void *data, int silent)
446{
447 struct inode *inode;
448
449 sb->s_blocksize = PAGE_CACHE_SIZE;
450 sb->s_blocksize_bits = PAGE_CACHE_SHIFT;
451 sb->s_magic = USBDEVICE_SUPER_MAGIC;
452 sb->s_op = &usbfs_ops;
453 sb->s_time_gran = 1;
454 inode = usbfs_get_inode(sb, S_IFDIR | 0755, 0);
455 sb->s_root = d_make_root(inode);
456 if (!sb->s_root) {
457 dbg("%s: could not get root dentry!",__func__);
458 return -ENOMEM;
459 }
460 return 0;
461}
462
463
464
465
466
467
468
469
470
471
472static int fs_create_by_name (const char *name, umode_t mode,
473 struct dentry *parent, struct dentry **dentry)
474{
475 int error = 0;
476
477
478
479
480
481
482 if (!parent ) {
483 if (usbfs_mount)
484 parent = usbfs_mount->mnt_root;
485 }
486
487 if (!parent) {
488 dbg("Ah! can not find a parent!");
489 return -EFAULT;
490 }
491
492 *dentry = NULL;
493 mutex_lock(&parent->d_inode->i_mutex);
494 *dentry = lookup_one_len(name, parent, strlen(name));
495 if (!IS_ERR(*dentry)) {
496 if (S_ISDIR(mode))
497 error = usbfs_mkdir (parent->d_inode, *dentry, mode);
498 else
499 error = usbfs_create (parent->d_inode, *dentry, mode);
500 } else
501 error = PTR_ERR(*dentry);
502 mutex_unlock(&parent->d_inode->i_mutex);
503
504 return error;
505}
506
507static struct dentry *fs_create_file (const char *name, umode_t mode,
508 struct dentry *parent, void *data,
509 const struct file_operations *fops,
510 uid_t uid, gid_t gid)
511{
512 struct dentry *dentry;
513 int error;
514
515 dbg("creating file '%s'",name);
516
517 error = fs_create_by_name (name, mode, parent, &dentry);
518 if (error) {
519 dentry = NULL;
520 } else {
521 if (dentry->d_inode) {
522 if (data)
523 dentry->d_inode->i_private = data;
524 if (fops)
525 dentry->d_inode->i_fop = fops;
526 dentry->d_inode->i_uid = uid;
527 dentry->d_inode->i_gid = gid;
528 }
529 }
530
531 return dentry;
532}
533
534static void fs_remove_file (struct dentry *dentry)
535{
536 struct dentry *parent = dentry->d_parent;
537
538 if (!parent || !parent->d_inode)
539 return;
540
541 mutex_lock_nested(&parent->d_inode->i_mutex, I_MUTEX_PARENT);
542 if (usbfs_positive(dentry)) {
543 if (dentry->d_inode) {
544 if (S_ISDIR(dentry->d_inode->i_mode))
545 usbfs_rmdir(parent->d_inode, dentry);
546 else
547 usbfs_unlink(parent->d_inode, dentry);
548 dput(dentry);
549 }
550 }
551 mutex_unlock(&parent->d_inode->i_mutex);
552}
553
554
555
556static struct dentry *usb_mount(struct file_system_type *fs_type,
557 int flags, const char *dev_name, void *data)
558{
559 return mount_single(fs_type, flags, data, usbfs_fill_super);
560}
561
562static struct file_system_type usb_fs_type = {
563 .owner = THIS_MODULE,
564 .name = "usbfs",
565 .mount = usb_mount,
566 .kill_sb = kill_litter_super,
567};
568
569
570
571static int create_special_files (void)
572{
573 struct dentry *parent;
574 int retval;
575
576
577 retval = simple_pin_fs(&usb_fs_type, &usbfs_mount, &usbfs_mount_count);
578 if (retval) {
579 printk(KERN_ERR "Unable to get usbfs mount\n");
580 goto exit;
581 }
582
583 parent = usbfs_mount->mnt_root;
584 devices_usbfs_dentry = fs_create_file ("devices",
585 listmode | S_IFREG, parent,
586 NULL, &usbfs_devices_fops,
587 listuid, listgid);
588 if (devices_usbfs_dentry == NULL) {
589 printk(KERN_ERR "Unable to create devices usbfs file\n");
590 retval = -ENODEV;
591 goto error_clean_mounts;
592 }
593
594 goto exit;
595
596error_clean_mounts:
597 simple_release_fs(&usbfs_mount, &usbfs_mount_count);
598exit:
599 return retval;
600}
601
602static void remove_special_files (void)
603{
604 if (devices_usbfs_dentry)
605 fs_remove_file (devices_usbfs_dentry);
606 devices_usbfs_dentry = NULL;
607 simple_release_fs(&usbfs_mount, &usbfs_mount_count);
608}
609
610void usbfs_update_special (void)
611{
612 struct inode *inode;
613
614 if (devices_usbfs_dentry) {
615 inode = devices_usbfs_dentry->d_inode;
616 if (inode)
617 inode->i_atime = inode->i_mtime = inode->i_ctime = CURRENT_TIME;
618 }
619}
620
621static void usbfs_add_bus(struct usb_bus *bus)
622{
623 struct dentry *parent;
624 char name[8];
625 int retval;
626
627
628 if (num_buses == 0) {
629 retval = create_special_files();
630 if (retval)
631 return;
632 }
633 ++num_buses;
634
635 sprintf (name, "%03d", bus->busnum);
636
637 parent = usbfs_mount->mnt_root;
638 bus->usbfs_dentry = fs_create_file (name, busmode | S_IFDIR, parent,
639 bus, NULL, busuid, busgid);
640 if (bus->usbfs_dentry == NULL) {
641 printk(KERN_ERR "Error creating usbfs bus entry\n");
642 return;
643 }
644}
645
646static void usbfs_remove_bus(struct usb_bus *bus)
647{
648 if (bus->usbfs_dentry) {
649 fs_remove_file (bus->usbfs_dentry);
650 bus->usbfs_dentry = NULL;
651 }
652
653 --num_buses;
654 if (num_buses <= 0) {
655 remove_special_files();
656 num_buses = 0;
657 }
658}
659
660static void usbfs_add_device(struct usb_device *dev)
661{
662 char name[8];
663 int i;
664 int i_size;
665
666 sprintf (name, "%03d", dev->devnum);
667 dev->usbfs_dentry = fs_create_file (name, devmode | S_IFREG,
668 dev->bus->usbfs_dentry, dev,
669 &usbdev_file_operations,
670 devuid, devgid);
671 if (dev->usbfs_dentry == NULL) {
672 printk(KERN_ERR "Error creating usbfs device entry\n");
673 return;
674 }
675
676
677
678 i_size = sizeof (struct usb_device_descriptor);
679 for (i = 0; i < dev->descriptor.bNumConfigurations; ++i) {
680 struct usb_config_descriptor *config =
681 (struct usb_config_descriptor *)dev->rawdescriptors[i];
682 i_size += le16_to_cpu(config->wTotalLength);
683 }
684 if (dev->usbfs_dentry->d_inode)
685 dev->usbfs_dentry->d_inode->i_size = i_size;
686}
687
688static void usbfs_remove_device(struct usb_device *dev)
689{
690 if (dev->usbfs_dentry) {
691 fs_remove_file (dev->usbfs_dentry);
692 dev->usbfs_dentry = NULL;
693 }
694}
695
696static int usbfs_notify(struct notifier_block *self, unsigned long action, void *dev)
697{
698 switch (action) {
699 case USB_DEVICE_ADD:
700 usbfs_add_device(dev);
701 break;
702 case USB_DEVICE_REMOVE:
703 usbfs_remove_device(dev);
704 break;
705 case USB_BUS_ADD:
706 usbfs_add_bus(dev);
707 break;
708 case USB_BUS_REMOVE:
709 usbfs_remove_bus(dev);
710 }
711
712 usbfs_update_special();
713 usbfs_conn_disc_event();
714 return NOTIFY_OK;
715}
716
717static struct notifier_block usbfs_nb = {
718 .notifier_call = usbfs_notify,
719};
720
721
722
723static struct proc_dir_entry *usbdir = NULL;
724
725int __init usbfs_init(void)
726{
727 int retval;
728
729 retval = register_filesystem(&usb_fs_type);
730 if (retval)
731 return retval;
732
733 usb_register_notify(&usbfs_nb);
734
735
736 usbdir = proc_mkdir("bus/usb", NULL);
737
738 return 0;
739}
740
741void usbfs_cleanup(void)
742{
743 usb_unregister_notify(&usbfs_nb);
744 unregister_filesystem(&usb_fs_type);
745 if (usbdir)
746 remove_proc_entry("bus/usb", NULL);
747}
748
749
