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6#include <linux/fs.h>
7#include <linux/file.h>
8#include <linux/module.h>
9#include <linux/init.h>
10#include <linux/slab.h>
11#include <linux/list.h>
12#include <linux/kernel.h>
13#include <linux/ctype.h>
14#include <linux/dcache.h>
15#include <linux/statfs.h>
16#include <asm/uaccess.h>
17#include <asm/fcntl.h>
18#include "os.h"
19
20static int init_inode(struct inode *inode, struct dentry *dentry);
21
22struct hppfs_data {
23 struct list_head list;
24 char contents[PAGE_SIZE - sizeof(struct list_head)];
25};
26
27struct hppfs_private {
28 struct file *proc_file;
29 int host_fd;
30 loff_t len;
31 struct hppfs_data *contents;
32};
33
34struct hppfs_inode_info {
35 struct dentry *proc_dentry;
36 struct inode vfs_inode;
37};
38
39static inline struct hppfs_inode_info *HPPFS_I(struct inode *inode)
40{
41 return container_of(inode, struct hppfs_inode_info, vfs_inode);
42}
43
44#define HPPFS_SUPER_MAGIC 0xb00000ee
45
46static const struct super_operations hppfs_sbops;
47
48static int is_pid(struct dentry *dentry)
49{
50 struct super_block *sb;
51 int i;
52
53 sb = dentry->d_sb;
54 if((sb->s_op != &hppfs_sbops) || (dentry->d_parent != sb->s_root))
55 return(0);
56
57 for(i = 0; i < dentry->d_name.len; i++){
58 if(!isdigit(dentry->d_name.name[i]))
59 return(0);
60 }
61 return(1);
62}
63
64static char *dentry_name(struct dentry *dentry, int extra)
65{
66 struct dentry *parent;
67 char *root, *name;
68 const char *seg_name;
69 int len, seg_len;
70
71 len = 0;
72 parent = dentry;
73 while(parent->d_parent != parent){
74 if(is_pid(parent))
75 len += strlen("pid") + 1;
76 else len += parent->d_name.len + 1;
77 parent = parent->d_parent;
78 }
79
80 root = "proc";
81 len += strlen(root);
82 name = kmalloc(len + extra + 1, GFP_KERNEL);
83 if(name == NULL) return(NULL);
84
85 name[len] = '\0';
86 parent = dentry;
87 while(parent->d_parent != parent){
88 if(is_pid(parent)){
89 seg_name = "pid";
90 seg_len = strlen("pid");
91 }
92 else {
93 seg_name = parent->d_name.name;
94 seg_len = parent->d_name.len;
95 }
96
97 len -= seg_len + 1;
98 name[len] = '/';
99 strncpy(&name[len + 1], seg_name, seg_len);
100 parent = parent->d_parent;
101 }
102 strncpy(name, root, strlen(root));
103 return(name);
104}
105
106struct dentry_operations hppfs_dentry_ops = {
107};
108
109static int file_removed(struct dentry *dentry, const char *file)
110{
111 char *host_file;
112 int extra, fd;
113
114 extra = 0;
115 if(file != NULL) extra += strlen(file) + 1;
116
117 host_file = dentry_name(dentry, extra + strlen("/remove"));
118 if(host_file == NULL){
119 printk("file_removed : allocation failed\n");
120 return(-ENOMEM);
121 }
122
123 if(file != NULL){
124 strcat(host_file, "/");
125 strcat(host_file, file);
126 }
127 strcat(host_file, "/remove");
128
129 fd = os_open_file(host_file, of_read(OPENFLAGS()), 0);
130 kfree(host_file);
131 if(fd > 0){
132 os_close_file(fd);
133 return(1);
134 }
135 return(0);
136}
137
138static void hppfs_read_inode(struct inode *ino)
139{
140 struct inode *proc_ino;
141
142 if(HPPFS_I(ino)->proc_dentry == NULL)
143 return;
144
145 proc_ino = HPPFS_I(ino)->proc_dentry->d_inode;
146 ino->i_uid = proc_ino->i_uid;
147 ino->i_gid = proc_ino->i_gid;
148 ino->i_atime = proc_ino->i_atime;
149 ino->i_mtime = proc_ino->i_mtime;
150 ino->i_ctime = proc_ino->i_ctime;
151 ino->i_ino = proc_ino->i_ino;
152 ino->i_mode = proc_ino->i_mode;
153 ino->i_nlink = proc_ino->i_nlink;
154 ino->i_size = proc_ino->i_size;
155 ino->i_blocks = proc_ino->i_blocks;
156}
157
158static 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 mutex_lock(&parent->d_inode->i_mutex);
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 mutex_unlock(&parent->d_inode->i_mutex);
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 mutex_unlock(&parent->d_inode->i_mutex);
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
215static const struct inode_operations hppfs_file_iops = {
216};
217
218static ssize_t read_proc(struct file *file, char __user *buf, ssize_t count,
219 loff_t *ppos, int is_user)
220{
221 ssize_t (*read)(struct file *, char __user *, size_t, loff_t *);
222 ssize_t n;
223
224 read = file->f_path.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
238static ssize_t hppfs_read_file(int fd, char __user *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 err);
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
276static ssize_t hppfs_read(struct file *file, char __user *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
315static ssize_t hppfs_write(struct file *file, const char __user *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 __user *, size_t, loff_t *);
321 int err;
322
323 write = proc_file->f_path.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
332static 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
350static 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
364static 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
430static 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
444static 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
455static 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_path.dentry, strlen("/rw"));
468 if(host_file == NULL)
469 goto out_free2;
470
471 proc_dentry = HPPFS_I(inode)->proc_dentry;
472
473
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
516static 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
543static 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_path.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
560static const 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
568struct hppfs_dirent {
569 void *vfs_dirent;
570 filldir_t filldir;
571 struct dentry *dentry;
572};
573
574static int hppfs_filldir(void *d, const char *name, int size,
575 loff_t offset, u64 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
586static 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_path.dentry } );
595 int err;
596
597 readdir = proc_file->f_path.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
606static int hppfs_fsync(struct file *file, struct dentry *dentry, int datasync)
607{
608 return(0);
609}
610
611static const struct file_operations hppfs_dir_fops = {
612 .owner = NULL,
613 .readdir = hppfs_readdir,
614 .open = hppfs_dir_open,
615 .fsync = hppfs_fsync,
616};
617
618static int hppfs_statfs(struct dentry *dentry, 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
629static 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
642void hppfs_delete_inode(struct inode *ino)
643{
644 clear_inode(ino);
645}
646
647static void hppfs_destroy_inode(struct inode *inode)
648{
649 kfree(HPPFS_I(inode));
650}
651
652static const 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
660static int hppfs_readlink(struct dentry *dentry, char __user *buffer, int buflen)
661{
662 struct file *proc_file;
663 struct dentry *proc_dentry;
664 int ret;
665
666 proc_dentry = HPPFS_I(dentry->d_inode)->proc_dentry;
667 proc_file = dentry_open(dget(proc_dentry), NULL, O_RDONLY);
668 if (IS_ERR(proc_file))
669 return PTR_ERR(proc_file);
670
671 ret = proc_dentry->d_inode->i_op->readlink(proc_dentry, buffer, buflen);
672
673 fput(proc_file);
674
675 return ret;
676}
677
678static void* hppfs_follow_link(struct dentry *dentry, struct nameidata *nd)
679{
680 struct file *proc_file;
681 struct dentry *proc_dentry;
682 void *ret;
683
684 proc_dentry = HPPFS_I(dentry->d_inode)->proc_dentry;
685 proc_file = dentry_open(dget(proc_dentry), NULL, O_RDONLY);
686 if (IS_ERR(proc_file))
687 return proc_file;
688
689 ret = proc_dentry->d_inode->i_op->follow_link(proc_dentry, nd);
690
691 fput(proc_file);
692
693 return ret;
694}
695
696static const struct inode_operations hppfs_dir_iops = {
697 .lookup = hppfs_lookup,
698};
699
700static const struct inode_operations hppfs_link_iops = {
701 .readlink = hppfs_readlink,
702 .follow_link = hppfs_follow_link,
703};
704
705static int init_inode(struct inode *inode, struct dentry *dentry)
706{
707 if(S_ISDIR(dentry->d_inode->i_mode)){
708 inode->i_op = &hppfs_dir_iops;
709 inode->i_fop = &hppfs_dir_fops;
710 }
711 else if(S_ISLNK(dentry->d_inode->i_mode)){
712 inode->i_op = &hppfs_link_iops;
713 inode->i_fop = &hppfs_file_fops;
714 }
715 else {
716 inode->i_op = &hppfs_file_iops;
717 inode->i_fop = &hppfs_file_fops;
718 }
719
720 HPPFS_I(inode)->proc_dentry = dentry;
721
722 return(0);
723}
724
725static int hppfs_fill_super(struct super_block *sb, void *d, int silent)
726{
727 struct inode *root_inode;
728 struct file_system_type *procfs;
729 struct super_block *proc_sb;
730 int err;
731
732 err = -ENOENT;
733 procfs = get_fs_type("proc");
734 if(procfs == NULL)
735 goto out;
736
737 if(list_empty(&procfs->fs_supers))
738 goto out;
739
740 proc_sb = list_entry(procfs->fs_supers.next, struct super_block,
741 s_instances);
742
743 sb->s_blocksize = 1024;
744 sb->s_blocksize_bits = 10;
745 sb->s_magic = HPPFS_SUPER_MAGIC;
746 sb->s_op = &hppfs_sbops;
747
748 root_inode = iget(sb, 0);
749 if(root_inode == NULL)
750 goto out;
751
752 err = init_inode(root_inode, proc_sb->s_root);
753 if(err)
754 goto out_put;
755
756 err = -ENOMEM;
757 sb->s_root = d_alloc_root(root_inode);
758 if(sb->s_root == NULL)
759 goto out_put;
760
761 hppfs_read_inode(root_inode);
762
763 return(0);
764
765 out_put:
766 iput(root_inode);
767 out:
768 return(err);
769}
770
771static int hppfs_read_super(struct file_system_type *type,
772 int flags, const char *dev_name,
773 void *data, struct vfsmount *mnt)
774{
775 return get_sb_nodev(type, flags, data, hppfs_fill_super, mnt);
776}
777
778static struct file_system_type hppfs_type = {
779 .owner = THIS_MODULE,
780 .name = "hppfs",
781 .get_sb = hppfs_read_super,
782 .kill_sb = kill_anon_super,
783 .fs_flags = 0,
784};
785
786static int __init init_hppfs(void)
787{
788 return(register_filesystem(&hppfs_type));
789}
790
791static void __exit exit_hppfs(void)
792{
793 unregister_filesystem(&hppfs_type);
794}
795
796module_init(init_hppfs)
797module_exit(exit_hppfs)
798MODULE_LICENSE("GPL");
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