1 /*
2 * Copyright (C) 2002 Jeff Dike (jdike@karaya.com)
3 * Licensed under the GPL
4 */
5
6 #include <linux/fs.h>
7 #include <linux/module.h>
8 #include <linux/init.h>
9 #include <linux/slab.h>
10 #include <linux/list.h>
11 #include <linux/kernel.h>
12 #include <linux/ctype.h>
13 #include <linux/dcache.h>
14 #include <linux/statfs.h>
15 #include <asm/uaccess.h>
16 #include <asm/fcntl.h>
17 #include "os.h"
18
19 static int init_inode(struct inode *inode, struct dentry *dentry);
20
21 struct hppfs_data {
22 struct list_head list;
23 char contents[PAGE_SIZE - sizeof(struct list_head)];
24 };
25
26 struct hppfs_private {
27 struct file *proc_file;
28 int host_fd;
29 loff_t len;
30 struct hppfs_data *contents;
31 };
32
33 struct hppfs_inode_info {
34 struct dentry *proc_dentry;
35 struct inode vfs_inode;
36 };
37
38 static inline struct hppfs_inode_info *HPPFS_I(struct inode *inode)
39 {
40 return(list_entry(inode, struct hppfs_inode_info, vfs_inode));
41 }
42
43 #define HPPFS_SUPER_MAGIC 0xb00000ee
44
45 static struct super_operations hppfs_sbops;
46
47 static int is_pid(struct dentry *dentry)
48 {
49 struct super_block *sb;
50 int i;
51
52 sb = dentry->d_sb;
53 if((sb->s_op != &hppfs_sbops) || (dentry->d_parent != sb->s_root))
54 return(0);
55
56 for(i = 0; i < dentry->d_name.len; i++){
57 if(!isdigit(dentry->d_name.name[i]))
58 return(0);
59 }
60 return(1);
61 }
62
63 static char *dentry_name(struct dentry *dentry, int extra)
64 {
65 struct dentry *parent;
66 char *root, *name;
67 const char *seg_name;
68 int len, seg_len;
69
70 len = 0;
71 parent = dentry;
72 while(parent->d_parent != parent){
73 if(is_pid(parent))
74 len += strlen("pid") + 1;
75 else len += parent->d_name.len + 1;
76 parent = parent->d_parent;
77 }
78
79 root = "proc";
80 len += strlen(root);
81 name = kmalloc(len + extra + 1, GFP_KERNEL);
82 if(name == NULL) return(NULL);
83
84 name[len] = '\0';
85 parent = dentry;
86 while(parent->d_parent != parent){
87 if(is_pid(parent)){
88 seg_name = "pid";
89 seg_len = strlen("pid");
90 }
91 else {
92 seg_name = parent->d_name.name;
93 seg_len = parent->d_name.len;
94 }
95
96 len -= seg_len + 1;
97 name[len] = '/';
98 strncpy(&name[len + 1], seg_name, seg_len);
99 parent = parent->d_parent;
100 }
101 strncpy(name, root, strlen(root));
102 return(name);
103 }
104
105 struct dentry_operations hppfs_dentry_ops = {
106 };
107
108 static int file_removed(struct dentry *dentry, const char *file)
109 {
110 char *host_file;
111 int extra, fd;
112
113 extra = 0;
114 if(file != NULL) extra += strlen(file) + 1;
115
116 host_file = dentry_name(dentry, extra + strlen("/remove"));
117 if(host_file == NULL){
118 printk("file_removed : allocation failed\n");
119 return(-ENOMEM);
120 }
121
122 if(file != NULL){
123 strcat(host_file, "/");
124 strcat(host_file, file);
125 }
126 strcat(host_file, "/remove");
127
128 fd = os_open_file(host_file, of_read(OPENFLAGS()), 0);
129 kfree(host_file);
130 if(fd > 0){
131 os_close_file(fd);
132 return(1);
133 }
134 return(0);
135 }
136
137 static void hppfs_read_inode(struct inode *ino)
138 {
139 struct inode *proc_ino;
140
141 if(HPPFS_I(ino)->proc_dentry == NULL)
142 return;
143
144 proc_ino = HPPFS_I(ino)->proc_dentry->d_inode;
145 ino->i_uid = proc_ino->i_uid;
146 ino->i_gid = proc_ino->i_gid;
147 ino->i_atime = proc_ino->i_atime;
148 ino->i_mtime = proc_ino->i_mtime;
149 ino->i_ctime = proc_ino->i_ctime;
150 ino->i_ino = proc_ino->i_ino;
151 ino->i_mode = proc_ino->i_mode;
152 ino->i_nlink = proc_ino->i_nlink;
153 ino->i_size = proc_ino->i_size;
154 ino->i_blksize = proc_ino->i_blksize;
155 ino->i_blocks = proc_ino->i_blocks;
156 }
157
158 static struct dentry *hppfs_lookup(struct inode *ino, struct dentry *dentry,
159 struct nameidata *nd)
160 {
161 struct dentry *proc_dentry, *new, *parent;
162 struct inode *inode;
163 int err, deleted;
164
165 deleted = file_removed(dentry, NULL);
166 if(deleted < 0)
167 return(ERR_PTR(deleted));
168 else if(deleted)
169 return(ERR_PTR(-ENOENT));
170
171 err = -ENOMEM;
172 parent = HPPFS_I(ino)->proc_dentry;
173 down(&parent->d_inode->i_sem);
174 proc_dentry = d_lookup(parent, &dentry->d_name);
175 if(proc_dentry == NULL){
176 proc_dentry = d_alloc(parent, &dentry->d_name);
177 if(proc_dentry == NULL){
178 up(&parent->d_inode->i_sem);
179 goto out;
180 }
181 new = (*parent->d_inode->i_op->lookup)(parent->d_inode,
182 proc_dentry, NULL);
183 if(new){
184 dput(proc_dentry);
185 proc_dentry = new;
186 }
187 }
188 up(&parent->d_inode->i_sem);
189
190 if(IS_ERR(proc_dentry))
191 return(proc_dentry);
192
193 inode = iget(ino->i_sb, 0);
194 if(inode == NULL)
195 goto out_dput;
196
197 err = init_inode(inode, proc_dentry);
198 if(err)
199 goto out_put;
200
201 hppfs_read_inode(inode);
202
203 d_add(dentry, inode);
204 dentry->d_op = &hppfs_dentry_ops;
205 return(NULL);
206
207 out_put:
208 iput(inode);
209 out_dput:
210 dput(proc_dentry);
211 out:
212 return(ERR_PTR(err));
213 }
214
215 static struct inode_operations hppfs_file_iops = {
216 };
217
218 static ssize_t read_proc(struct file *file, char *buf, ssize_t count,
219 loff_t *ppos, int is_user)
220 {
221 ssize_t (*read)(struct file *, char *, size_t, loff_t *);
222 ssize_t n;
223
224 read = file->f_dentry->d_inode->i_fop->read;
225
226 if(!is_user)
227 set_fs(KERNEL_DS);
228
229 n = (*read)(file, buf, count, &file->f_pos);
230
231 if(!is_user)
232 set_fs(USER_DS);
233
234 if(ppos) *ppos = file->f_pos;
235 return(n);
236 }
237
238 static ssize_t hppfs_read_file(int fd, char *buf, ssize_t count)
239 {
240 ssize_t n;
241 int cur, err;
242 char *new_buf;
243
244 n = -ENOMEM;
245 new_buf = kmalloc(PAGE_SIZE, GFP_KERNEL);
246 if(new_buf == NULL){
247 printk("hppfs_read_file : kmalloc failed\n");
248 goto out;
249 }
250 n = 0;
251 while(count > 0){
252 cur = min_t(ssize_t, count, PAGE_SIZE);
253 err = os_read_file(fd, new_buf, cur);
254 if(err < 0){
255 printk("hppfs_read : read failed, errno = %d\n",
256 count);
257 n = err;
258 goto out_free;
259 }
260 else if(err == 0)
261 break;
262
263 if(copy_to_user(buf, new_buf, err)){
264 n = -EFAULT;
265 goto out_free;
266 }
267 n += err;
268 count -= err;
269 }
270 out_free:
271 kfree(new_buf);
272 out:
273 return(n);
274 }
275
276 static ssize_t hppfs_read(struct file *file, char *buf, size_t count,
277 loff_t *ppos)
278 {
279 struct hppfs_private *hppfs = file->private_data;
280 struct hppfs_data *data;
281 loff_t off;
282 int err;
283
284 if(hppfs->contents != NULL){
285 if(*ppos >= hppfs->len) return(0);
286
287 data = hppfs->contents;
288 off = *ppos;
289 while(off >= sizeof(data->contents)){
290 data = list_entry(data->list.next, struct hppfs_data,
291 list);
292 off -= sizeof(data->contents);
293 }
294
295 if(off + count > hppfs->len)
296 count = hppfs->len - off;
297 copy_to_user(buf, &data->contents[off], count);
298 *ppos += count;
299 }
300 else if(hppfs->host_fd != -1){
301 err = os_seek_file(hppfs->host_fd, *ppos);
302 if(err){
303 printk("hppfs_read : seek failed, errno = %d\n", err);
304 return(err);
305 }
306 count = hppfs_read_file(hppfs->host_fd, buf, count);
307 if(count > 0)
308 *ppos += count;
309 }
310 else count = read_proc(hppfs->proc_file, buf, count, ppos, 1);
311
312 return(count);
313 }
314
315 static ssize_t hppfs_write(struct file *file, const char *buf, size_t len,
316 loff_t *ppos)
317 {
318 struct hppfs_private *data = file->private_data;
319 struct file *proc_file = data->proc_file;
320 ssize_t (*write)(struct file *, const char *, size_t, loff_t *);
321 int err;
322
323 write = proc_file->f_dentry->d_inode->i_fop->write;
324
325 proc_file->f_pos = file->f_pos;
326 err = (*write)(proc_file, buf, len, &proc_file->f_pos);
327 file->f_pos = proc_file->f_pos;
328
329 return(err);
330 }
331
332 static int open_host_sock(char *host_file, int *filter_out)
333 {
334 char *end;
335 int fd;
336
337 end = &host_file[strlen(host_file)];
338 strcpy(end, "/rw");
339 *filter_out = 1;
340 fd = os_connect_socket(host_file);
341 if(fd > 0)
342 return(fd);
343
344 strcpy(end, "/r");
345 *filter_out = 0;
346 fd = os_connect_socket(host_file);
347 return(fd);
348 }
349
350 static void free_contents(struct hppfs_data *head)
351 {
352 struct hppfs_data *data;
353 struct list_head *ele, *next;
354
355 if(head == NULL) return;
356
357 list_for_each_safe(ele, next, &head->list){
358 data = list_entry(ele, struct hppfs_data, list);
359 kfree(data);
360 }
361 kfree(head);
362 }
363
364 static struct hppfs_data *hppfs_get_data(int fd, int filter,
365 struct file *proc_file,
366 struct file *hppfs_file,
367 loff_t *size_out)
368 {
369 struct hppfs_data *data, *new, *head;
370 int n, err;
371
372 err = -ENOMEM;
373 data = kmalloc(sizeof(*data), GFP_KERNEL);
374 if(data == NULL){
375 printk("hppfs_get_data : head allocation failed\n");
376 goto failed;
377 }
378
379 INIT_LIST_HEAD(&data->list);
380
381 head = data;
382 *size_out = 0;
383
384 if(filter){
385 while((n = read_proc(proc_file, data->contents,
386 sizeof(data->contents), NULL, 0)) > 0)
387 os_write_file(fd, data->contents, n);
388 err = os_shutdown_socket(fd, 0, 1);
389 if(err){
390 printk("hppfs_get_data : failed to shut down "
391 "socket\n");
392 goto failed_free;
393 }
394 }
395 while(1){
396 n = os_read_file(fd, data->contents, sizeof(data->contents));
397 if(n < 0){
398 err = n;
399 printk("hppfs_get_data : read failed, errno = %d\n",
400 err);
401 goto failed_free;
402 }
403 else if(n == 0)
404 break;
405
406 *size_out += n;
407
408 if(n < sizeof(data->contents))
409 break;
410
411 new = kmalloc(sizeof(*data), GFP_KERNEL);
412 if(new == 0){
413 printk("hppfs_get_data : data allocation failed\n");
414 err = -ENOMEM;
415 goto failed_free;
416 }
417
418 INIT_LIST_HEAD(&new->list);
419 list_add(&new->list, &data->list);
420 data = new;
421 }
422 return(head);
423
424 failed_free:
425 free_contents(head);
426 failed:
427 return(ERR_PTR(err));
428 }
429
430 static struct hppfs_private *hppfs_data(void)
431 {
432 struct hppfs_private *data;
433
434 data = kmalloc(sizeof(*data), GFP_KERNEL);
435 if(data == NULL)
436 return(data);
437
438 *data = ((struct hppfs_private ) { .host_fd = -1,
439 .len = -1,
440 .contents = NULL } );
441 return(data);
442 }
443
444 static int file_mode(int fmode)
445 {
446 if(fmode == (FMODE_READ | FMODE_WRITE))
447 return(O_RDWR);
448 if(fmode == FMODE_READ)
449 return(O_RDONLY);
450 if(fmode == FMODE_WRITE)
451 return(O_WRONLY);
452 return(0);
453 }
454
455 static int hppfs_open(struct inode *inode, struct file *file)
456 {
457 struct hppfs_private *data;
458 struct dentry *proc_dentry;
459 char *host_file;
460 int err, fd, type, filter;
461
462 err = -ENOMEM;
463 data = hppfs_data();
464 if(data == NULL)
465 goto out;
466
467 host_file = dentry_name(file->f_dentry, strlen("/rw"));
468 if(host_file == NULL)
469 goto out_free2;
470
471 proc_dentry = HPPFS_I(inode)->proc_dentry;
472
473 /* XXX This isn't closed anywhere */
474 data->proc_file = dentry_open(dget(proc_dentry), NULL,
475 file_mode(file->f_mode));
476 err = PTR_ERR(data->proc_file);
477 if(IS_ERR(data->proc_file))
478 goto out_free1;
479
480 type = os_file_type(host_file);
481 if(type == OS_TYPE_FILE){
482 fd = os_open_file(host_file, of_read(OPENFLAGS()), 0);
483 if(fd >= 0)
484 data->host_fd = fd;
485 else printk("hppfs_open : failed to open '%s', errno = %d\n",
486 host_file, -fd);
487
488 data->contents = NULL;
489 }
490 else if(type == OS_TYPE_DIR){
491 fd = open_host_sock(host_file, &filter);
492 if(fd > 0){
493 data->contents = hppfs_get_data(fd, filter,
494 &data->proc_file,
495 file, &data->len);
496 if(!IS_ERR(data->contents))
497 data->host_fd = fd;
498 }
499 else printk("hppfs_open : failed to open a socket in "
500 "'%s', errno = %d\n", host_file, -fd);
501 }
502 kfree(host_file);
503
504 file->private_data = data;
505 return(0);
506
507 out_free1:
508 kfree(host_file);
509 out_free2:
510 free_contents(data->contents);
511 kfree(data);
512 out:
513 return(err);
514 }
515
516 static int hppfs_dir_open(struct inode *inode, struct file *file)
517 {
518 struct hppfs_private *data;
519 struct dentry *proc_dentry;
520 int err;
521
522 err = -ENOMEM;
523 data = hppfs_data();
524 if(data == NULL)
525 goto out;
526
527 proc_dentry = HPPFS_I(inode)->proc_dentry;
528 data->proc_file = dentry_open(dget(proc_dentry), NULL,
529 file_mode(file->f_mode));
530 err = PTR_ERR(data->proc_file);
531 if(IS_ERR(data->proc_file))
532 goto out_free;
533
534 file->private_data = data;
535 return(0);
536
537 out_free:
538 kfree(data);
539 out:
540 return(err);
541 }
542
543 static loff_t hppfs_llseek(struct file *file, loff_t off, int where)
544 {
545 struct hppfs_private *data = file->private_data;
546 struct file *proc_file = &data->proc_file;
547 loff_t (*llseek)(struct file *, loff_t, int);
548 loff_t ret;
549
550 llseek = proc_file->f_dentry->d_inode->i_fop->llseek;
551 if(llseek != NULL){
552 ret = (*llseek)(proc_file, off, where);
553 if(ret < 0)
554 return(ret);
555 }
556
557 return(default_llseek(file, off, where));
558 }
559
560 static struct file_operations hppfs_file_fops = {
561 .owner = NULL,
562 .llseek = hppfs_llseek,
563 .read = hppfs_read,
564 .write = hppfs_write,
565 .open = hppfs_open,
566 };
567
568 struct hppfs_dirent {
569 void *vfs_dirent;
570 filldir_t filldir;
571 struct dentry *dentry;
572 };
573
574 static int hppfs_filldir(void *d, const char *name, int size,
575 loff_t offset, ino_t inode, unsigned int type)
576 {
577 struct hppfs_dirent *dirent = d;
578
579 if(file_removed(dirent->dentry, name))
580 return(0);
581
582 return((*dirent->filldir)(dirent->vfs_dirent, name, size, offset,
583 inode, type));
584 }
585
586 static int hppfs_readdir(struct file *file, void *ent, filldir_t filldir)
587 {
588 struct hppfs_private *data = file->private_data;
589 struct file *proc_file = &data->proc_file;
590 int (*readdir)(struct file *, void *, filldir_t);
591 struct hppfs_dirent dirent = ((struct hppfs_dirent)
592 { .vfs_dirent = ent,
593 .filldir = filldir,
594 .dentry = file->f_dentry } );
595 int err;
596
597 readdir = proc_file->f_dentry->d_inode->i_fop->readdir;
598
599 proc_file->f_pos = file->f_pos;
600 err = (*readdir)(proc_file, &dirent, hppfs_filldir);
601 file->f_pos = proc_file->f_pos;
602
603 return(err);
604 }
605
606 static int hppfs_fsync(struct file *file, struct dentry *dentry, int datasync)
607 {
608 return(0);
609 }
610
611 static struct file_operations hppfs_dir_fops = {
612 .owner = NULL,
613 .readdir = hppfs_readdir,
614 .open = hppfs_dir_open,
615 .fsync = hppfs_fsync,
616 };
617
618 static int hppfs_statfs(struct super_block *sb, struct kstatfs *sf)
619 {
620 sf->f_blocks = 0;
621 sf->f_bfree = 0;
622 sf->f_bavail = 0;
623 sf->f_files = 0;
624 sf->f_ffree = 0;
625 sf->f_type = HPPFS_SUPER_MAGIC;
626 return(0);
627 }
628
629 static struct inode *hppfs_alloc_inode(struct super_block *sb)
630 {
631 struct hppfs_inode_info *hi;
632
633 hi = kmalloc(sizeof(*hi), GFP_KERNEL);
634 if(hi == NULL)
635 return(NULL);
636
637 *hi = ((struct hppfs_inode_info) { .proc_dentry = NULL });
638 inode_init_once(&hi->vfs_inode);
639 return(&hi->vfs_inode);
640 }
641
642 void hppfs_delete_inode(struct inode *ino)
643 {
644 clear_inode(ino);
645 }
646
647 static void hppfs_destroy_inode(struct inode *inode)
648 {
649 kfree(HPPFS_I(inode));
650 }
651
652 static struct super_operations hppfs_sbops = {
653 .alloc_inode = hppfs_alloc_inode,
654 .destroy_inode = hppfs_destroy_inode,
655 .read_inode = hppfs_read_inode,
656 .delete_inode = hppfs_delete_inode,
657 .statfs = hppfs_statfs,
658 };
659
660 static int hppfs_readlink(struct dentry *dentry, char *buffer, int buflen)
661 {
662 struct file *proc_file;
663 struct dentry *proc_dentry;
664 int (*readlink)(struct dentry *, char *, int);
665 int err, n;
666
667 proc_dentry = HPPFS_I(dentry->d_inode)->proc_dentry;
668 proc_file = dentry_open(dget(proc_dentry), NULL, O_RDONLY);
669 err = PTR_ERR(proc_dentry);
670 if(IS_ERR(proc_dentry))
671 return(err);
672
673 readlink = proc_dentry->d_inode->i_op->readlink;
674 n = (*readlink)(proc_dentry, buffer, buflen);
675
676 fput(proc_file);
677
678 return(n);
679 }
680
681 static int hppfs_follow_link(struct dentry *dentry, struct nameidata *nd)
682 {
683 struct file *proc_file;
684 struct dentry *proc_dentry;
685 int (*follow_link)(struct dentry *, struct nameidata *);
686 int err, n;
687
688 proc_dentry = HPPFS_I(dentry->d_inode)->proc_dentry;
689 proc_file = dentry_open(dget(proc_dentry), NULL, O_RDONLY);
690 err = PTR_ERR(proc_dentry);
691 if(IS_ERR(proc_dentry))
692 return(err);
693
694 follow_link = proc_dentry->d_inode->i_op->follow_link;
695 n = (*follow_link)(proc_dentry, nd);
696
697 fput(proc_file);
698
699 return(n);
700 }
701
702 static struct inode_operations hppfs_dir_iops = {
703 .lookup = hppfs_lookup,
704 };
705
706 static struct inode_operations hppfs_link_iops = {
707 .readlink = hppfs_readlink,
708 .follow_link = hppfs_follow_link,
709 };
710
711 static int init_inode(struct inode *inode, struct dentry *dentry)
712 {
713 if(S_ISDIR(dentry->d_inode->i_mode)){
714 inode->i_op = &hppfs_dir_iops;
715 inode->i_fop = &hppfs_dir_fops;
716 }
717 else if(S_ISLNK(dentry->d_inode->i_mode)){
718 inode->i_op = &hppfs_link_iops;
719 inode->i_fop = &hppfs_file_fops;
720 }
721 else {
722 inode->i_op = &hppfs_file_iops;
723 inode->i_fop = &hppfs_file_fops;
724 }
725
726 HPPFS_I(inode)->proc_dentry = dentry;
727
728 return(0);
729 }
730
731 static int hppfs_fill_super(struct super_block *sb, void *d, int silent)
732 {
733 struct inode *root_inode;
734 struct file_system_type *procfs;
735 struct super_block *proc_sb;
736 int err;
737
738 err = -ENOENT;
739 procfs = get_fs_type("proc");
740 if(procfs == NULL)
741 goto out;
742
743 if(list_empty(&procfs->fs_supers))
744 goto out;
745
746 proc_sb = list_entry(procfs->fs_supers.next, struct super_block,
747 s_instances);
748
749 sb->s_blocksize = 1024;
750 sb->s_blocksize_bits = 10;
751 sb->s_magic = HPPFS_SUPER_MAGIC;
752 sb->s_op = &hppfs_sbops;
753
754 root_inode = iget(sb, 0);
755 if(root_inode == NULL)
756 goto out;
757
758 err = init_inode(root_inode, proc_sb->s_root);
759 if(err)
760 goto out_put;
761
762 err = -ENOMEM;
763 sb->s_root = d_alloc_root(root_inode);
764 if(sb->s_root == NULL)
765 goto out_put;
766
767 hppfs_read_inode(root_inode);
768
769 return(0);
770
771 out_put:
772 iput(root_inode);
773 out:
774 return(err);
775 }
776
777 static struct super_block *hppfs_read_super(struct file_system_type *type,
778 int flags, const char *dev_name,
779 void *data)
780 {
781 return(get_sb_nodev(type, flags, data, hppfs_fill_super));
782 }
783
784 static struct file_system_type hppfs_type = {
785 .owner = THIS_MODULE,
786 .name = "hppfs",
787 .get_sb = hppfs_read_super,
788 .kill_sb = kill_anon_super,
789 .fs_flags = 0,
790 };
791
792 static int __init init_hppfs(void)
793 {
794 return(register_filesystem(&hppfs_type));
795 }
796
797 static void __exit exit_hppfs(void)
798 {
799 unregister_filesystem(&hppfs_type);
800 }
801
802 module_init(init_hppfs)
803 module_exit(exit_hppfs)
804 MODULE_LICENSE("GPL");
805
806 /*
807 * Overrides for Emacs so that we follow Linus's tabbing style.
808 * Emacs will notice this stuff at the end of the file and automatically
809 * adjust the settings for this buffer only. This must remain at the end
810 * of the file.
811 * ---------------------------------------------------------------------------
812 * Local variables:
813 * c-file-style: "linux"
814 * End:
815 */
816
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