1// SPDX-License-Identifier: GPL-2.0
2/*
3 *  linux/fs/hfsplus/dir.c
4 *
5 * Copyright (C) 2001
6 * Brad Boyer (flar@allandria.com)
7 * (C) 2003 Ardis Technologies <roman@ardistech.com>
8 *
9 * Handling of directories
10 */
11
12#include <linux/errno.h>
13#include <linux/fs.h>
14#include <linux/slab.h>
15#include <linux/random.h>
16#include <linux/nls.h>
17
18#include "hfsplus_fs.h"
19#include "hfsplus_raw.h"
20#include "xattr.h"
21
22static inline void hfsplus_instantiate(struct dentry *dentry,
23				       struct inode *inode, u32 cnid)
24{
25	dentry->d_fsdata = (void *)(unsigned long)cnid;
26	d_instantiate(dentry, inode);
27}
28
29/* Find the entry inside dir named dentry->d_name */
30static struct dentry *hfsplus_lookup(struct inode *dir, struct dentry *dentry,
31				     unsigned int flags)
32{
33	struct inode *inode = NULL;
34	struct hfs_find_data fd;
35	struct super_block *sb;
36	hfsplus_cat_entry entry;
37	int err;
38	u32 cnid, linkid = 0;
39	u16 type;
40
41	sb = dir->i_sb;
42
43	dentry->d_fsdata = NULL;
44	err = hfs_find_init(HFSPLUS_SB(sb)->cat_tree, &fd);
45	if (err)
46		return ERR_PTR(err);
47	err = hfsplus_cat_build_key(sb, fd.search_key, dir->i_ino,
48			&dentry->d_name);
49	if (unlikely(err < 0))
50		goto fail;
51again:
52	err = hfs_brec_read(&fd, &entry, sizeof(entry));
53	if (err) {
54		if (err == -ENOENT) {
55			hfs_find_exit(&fd);
56			/* No such entry */
57			inode = NULL;
58			goto out;
59		}
60		goto fail;
61	}
62	type = be16_to_cpu(entry.type);
63	if (type == HFSPLUS_FOLDER) {
64		if (fd.entrylength < sizeof(struct hfsplus_cat_folder)) {
65			err = -EIO;
66			goto fail;
67		}
68		cnid = be32_to_cpu(entry.folder.id);
69		dentry->d_fsdata = (void *)(unsigned long)cnid;
70	} else if (type == HFSPLUS_FILE) {
71		if (fd.entrylength < sizeof(struct hfsplus_cat_file)) {
72			err = -EIO;
73			goto fail;
74		}
75		cnid = be32_to_cpu(entry.file.id);
76		if (entry.file.user_info.fdType ==
77				cpu_to_be32(HFSP_HARDLINK_TYPE) &&
78				entry.file.user_info.fdCreator ==
79				cpu_to_be32(HFSP_HFSPLUS_CREATOR) &&
80				HFSPLUS_SB(sb)->hidden_dir &&
81				(entry.file.create_date ==
82					HFSPLUS_I(HFSPLUS_SB(sb)->hidden_dir)->
83						create_date ||
84				entry.file.create_date ==
85					HFSPLUS_I(d_inode(sb->s_root))->
86						create_date)) {
87			struct qstr str;
88			char name[32];
89
90			if (dentry->d_fsdata) {
91				/*
92				 * We found a link pointing to another link,
93				 * so ignore it and treat it as regular file.
94				 */
95				cnid = (unsigned long)dentry->d_fsdata;
96				linkid = 0;
97			} else {
98				dentry->d_fsdata = (void *)(unsigned long)cnid;
99				linkid =
100					be32_to_cpu(entry.file.permissions.dev);
101				str.len = sprintf(name, "iNode%d", linkid);
102				str.name = name;
103				err = hfsplus_cat_build_key(sb, fd.search_key,
104					HFSPLUS_SB(sb)->hidden_dir->i_ino,
105					&str);
106				if (unlikely(err < 0))
107					goto fail;
108				goto again;
109			}
110		} else if (!dentry->d_fsdata)
111			dentry->d_fsdata = (void *)(unsigned long)cnid;
112	} else {
113		pr_err("invalid catalog entry type in lookup\n");
114		err = -EIO;
115		goto fail;
116	}
117	hfs_find_exit(&fd);
118	inode = hfsplus_iget(dir->i_sb, cnid);
119	if (IS_ERR(inode))
120		return ERR_CAST(inode);
121	if (S_ISREG(inode->i_mode))
122		HFSPLUS_I(inode)->linkid = linkid;
123out:
124	return d_splice_alias(inode, dentry);
125fail:
126	hfs_find_exit(&fd);
127	return ERR_PTR(err);
128}
129
130static int hfsplus_readdir(struct file *file, struct dir_context *ctx)
131{
132	struct inode *inode = file_inode(file);
133	struct super_block *sb = inode->i_sb;
134	int len, err;
135	char *strbuf;
136	hfsplus_cat_entry entry;
137	struct hfs_find_data fd;
138	struct hfsplus_readdir_data *rd;
139	u16 type;
140
141	if (file->f_pos >= inode->i_size)
142		return 0;
143
144	err = hfs_find_init(HFSPLUS_SB(sb)->cat_tree, &fd);
145	if (err)
146		return err;
147	strbuf = kmalloc(NLS_MAX_CHARSET_SIZE * HFSPLUS_MAX_STRLEN + 1, GFP_KERNEL);
148	if (!strbuf) {
149		err = -ENOMEM;
150		goto out;
151	}
152	hfsplus_cat_build_key_with_cnid(sb, fd.search_key, inode->i_ino);
153	err = hfs_brec_find(&fd, hfs_find_rec_by_key);
154	if (err)
155		goto out;
156
157	if (ctx->pos == 0) {
158		/* This is completely artificial... */
159		if (!dir_emit_dot(file, ctx))
160			goto out;
161		ctx->pos = 1;
162	}
163	if (ctx->pos == 1) {
164		if (fd.entrylength > sizeof(entry) || fd.entrylength < 0) {
165			err = -EIO;
166			goto out;
167		}
168
169		hfs_bnode_read(fd.bnode, &entry, fd.entryoffset,
170			fd.entrylength);
171		if (be16_to_cpu(entry.type) != HFSPLUS_FOLDER_THREAD) {
172			pr_err("bad catalog folder thread\n");
173			err = -EIO;
174			goto out;
175		}
176		if (fd.entrylength < HFSPLUS_MIN_THREAD_SZ) {
177			pr_err("truncated catalog thread\n");
178			err = -EIO;
179			goto out;
180		}
181		if (!dir_emit(ctx, "..", 2,
182			    be32_to_cpu(entry.thread.parentID), DT_DIR))
183			goto out;
184		ctx->pos = 2;
185	}
186	if (ctx->pos >= inode->i_size)
187		goto out;
188	err = hfs_brec_goto(&fd, ctx->pos - 1);
189	if (err)
190		goto out;
191	for (;;) {
192		if (be32_to_cpu(fd.key->cat.parent) != inode->i_ino) {
193			pr_err("walked past end of dir\n");
194			err = -EIO;
195			goto out;
196		}
197
198		if (fd.entrylength > sizeof(entry) || fd.entrylength < 0) {
199			err = -EIO;
200			goto out;
201		}
202
203		hfs_bnode_read(fd.bnode, &entry, fd.entryoffset,
204			fd.entrylength);
205		type = be16_to_cpu(entry.type);
206		len = NLS_MAX_CHARSET_SIZE * HFSPLUS_MAX_STRLEN;
207		err = hfsplus_uni2asc(sb, &fd.key->cat.name, strbuf, &len);
208		if (err)
209			goto out;
210		if (type == HFSPLUS_FOLDER) {
211			if (fd.entrylength <
212					sizeof(struct hfsplus_cat_folder)) {
213				pr_err("small dir entry\n");
214				err = -EIO;
215				goto out;
216			}
217			if (HFSPLUS_SB(sb)->hidden_dir &&
218			    HFSPLUS_SB(sb)->hidden_dir->i_ino ==
219					be32_to_cpu(entry.folder.id))
220				goto next;
221			if (!dir_emit(ctx, strbuf, len,
222				    be32_to_cpu(entry.folder.id), DT_DIR))
223				break;
224		} else if (type == HFSPLUS_FILE) {
225			u16 mode;
226			unsigned type = DT_UNKNOWN;
227
228			if (fd.entrylength < sizeof(struct hfsplus_cat_file)) {
229				pr_err("small file entry\n");
230				err = -EIO;
231				goto out;
232			}
233
234			mode = be16_to_cpu(entry.file.permissions.mode);
235			if (S_ISREG(mode))
236				type = DT_REG;
237			else if (S_ISLNK(mode))
238				type = DT_LNK;
239			else if (S_ISFIFO(mode))
240				type = DT_FIFO;
241			else if (S_ISCHR(mode))
242				type = DT_CHR;
243			else if (S_ISBLK(mode))
244				type = DT_BLK;
245			else if (S_ISSOCK(mode))
246				type = DT_SOCK;
247
248			if (!dir_emit(ctx, strbuf, len,
249				      be32_to_cpu(entry.file.id), type))
250				break;
251		} else {
252			pr_err("bad catalog entry type\n");
253			err = -EIO;
254			goto out;
255		}
256next:
257		ctx->pos++;
258		if (ctx->pos >= inode->i_size)
259			goto out;
260		err = hfs_brec_goto(&fd, 1);
261		if (err)
262			goto out;
263	}
264	rd = file->private_data;
265	if (!rd) {
266		rd = kmalloc(sizeof(struct hfsplus_readdir_data), GFP_KERNEL);
267		if (!rd) {
268			err = -ENOMEM;
269			goto out;
270		}
271		file->private_data = rd;
272		rd->file = file;
273		spin_lock(&HFSPLUS_I(inode)->open_dir_lock);
274		list_add(&rd->list, &HFSPLUS_I(inode)->open_dir_list);
275		spin_unlock(&HFSPLUS_I(inode)->open_dir_lock);
276	}
277	/*
278	 * Can be done after the list insertion; exclusion with
279	 * hfsplus_delete_cat() is provided by directory lock.
280	 */
281	memcpy(&rd->key, fd.key, sizeof(struct hfsplus_cat_key));
282out:
283	kfree(strbuf);
284	hfs_find_exit(&fd);
285	return err;
286}
287
288static int hfsplus_dir_release(struct inode *inode, struct file *file)
289{
290	struct hfsplus_readdir_data *rd = file->private_data;
291	if (rd) {
292		spin_lock(&HFSPLUS_I(inode)->open_dir_lock);
293		list_del(&rd->list);
294		spin_unlock(&HFSPLUS_I(inode)->open_dir_lock);
295		kfree(rd);
296	}
297	return 0;
298}
299
300static int hfsplus_link(struct dentry *src_dentry, struct inode *dst_dir,
301			struct dentry *dst_dentry)
302{
303	struct hfsplus_sb_info *sbi = HFSPLUS_SB(dst_dir->i_sb);
304	struct inode *inode = d_inode(src_dentry);
305	struct inode *src_dir = d_inode(src_dentry->d_parent);
306	struct qstr str;
307	char name[32];
308	u32 cnid, id;
309	int res;
310
311	if (HFSPLUS_IS_RSRC(inode))
312		return -EPERM;
313	if (!S_ISREG(inode->i_mode))
314		return -EPERM;
315
316	mutex_lock(&sbi->vh_mutex);
317	if (inode->i_ino == (u32)(unsigned long)src_dentry->d_fsdata) {
318		for (;;) {
319			get_random_bytes(&id, sizeof(cnid));
320			id &= 0x3fffffff;
321			str.name = name;
322			str.len = sprintf(name, "iNode%d", id);
323			res = hfsplus_rename_cat(inode->i_ino,
324						 src_dir, &src_dentry->d_name,
325						 sbi->hidden_dir, &str);
326			if (!res)
327				break;
328			if (res != -EEXIST)
329				goto out;
330		}
331		HFSPLUS_I(inode)->linkid = id;
332		cnid = sbi->next_cnid++;
333		src_dentry->d_fsdata = (void *)(unsigned long)cnid;
334		res = hfsplus_create_cat(cnid, src_dir,
335			&src_dentry->d_name, inode);
336		if (res)
337			/* panic? */
338			goto out;
339		sbi->file_count++;
340	}
341	cnid = sbi->next_cnid++;
342	res = hfsplus_create_cat(cnid, dst_dir, &dst_dentry->d_name, inode);
343	if (res)
344		goto out;
345
346	inc_nlink(inode);
347	hfsplus_instantiate(dst_dentry, inode, cnid);
348	ihold(inode);
349	inode_set_ctime_current(inode);
350	mark_inode_dirty(inode);
351	sbi->file_count++;
352	hfsplus_mark_mdb_dirty(dst_dir->i_sb);
353out:
354	mutex_unlock(&sbi->vh_mutex);
355	return res;
356}
357
358static int hfsplus_unlink(struct inode *dir, struct dentry *dentry)
359{
360	struct hfsplus_sb_info *sbi = HFSPLUS_SB(dir->i_sb);
361	struct inode *inode = d_inode(dentry);
362	struct qstr str;
363	char name[32];
364	u32 cnid;
365	int res;
366
367	if (HFSPLUS_IS_RSRC(inode))
368		return -EPERM;
369
370	mutex_lock(&sbi->vh_mutex);
371	cnid = (u32)(unsigned long)dentry->d_fsdata;
372	if (inode->i_ino == cnid &&
373	    atomic_read(&HFSPLUS_I(inode)->opencnt)) {
374		str.name = name;
375		str.len = sprintf(name, "temp%lu", inode->i_ino);
376		res = hfsplus_rename_cat(inode->i_ino,
377					 dir, &dentry->d_name,
378					 sbi->hidden_dir, &str);
379		if (!res) {
380			inode->i_flags |= S_DEAD;
381			drop_nlink(inode);
382		}
383		goto out;
384	}
385	res = hfsplus_delete_cat(cnid, dir, &dentry->d_name);
386	if (res)
387		goto out;
388
389	if (inode->i_nlink > 0)
390		drop_nlink(inode);
391	if (inode->i_ino == cnid)
392		clear_nlink(inode);
393	if (!inode->i_nlink) {
394		if (inode->i_ino != cnid) {
395			sbi->file_count--;
396			if (!atomic_read(&HFSPLUS_I(inode)->opencnt)) {
397				res = hfsplus_delete_cat(inode->i_ino,
398							 sbi->hidden_dir,
399							 NULL);
400				if (!res)
401					hfsplus_delete_inode(inode);
402			} else
403				inode->i_flags |= S_DEAD;
404		} else
405			hfsplus_delete_inode(inode);
406	} else
407		sbi->file_count--;
408	inode_set_ctime_current(inode);
409	mark_inode_dirty(inode);
410out:
411	mutex_unlock(&sbi->vh_mutex);
412	return res;
413}
414
415static int hfsplus_rmdir(struct inode *dir, struct dentry *dentry)
416{
417	struct hfsplus_sb_info *sbi = HFSPLUS_SB(dir->i_sb);
418	struct inode *inode = d_inode(dentry);
419	int res;
420
421	if (inode->i_size != 2)
422		return -ENOTEMPTY;
423
424	mutex_lock(&sbi->vh_mutex);
425	res = hfsplus_delete_cat(inode->i_ino, dir, &dentry->d_name);
426	if (res)
427		goto out;
428	clear_nlink(inode);
429	inode_set_ctime_current(inode);
430	hfsplus_delete_inode(inode);
431	mark_inode_dirty(inode);
432out:
433	mutex_unlock(&sbi->vh_mutex);
434	return res;
435}
436
437static int hfsplus_symlink(struct mnt_idmap *idmap, struct inode *dir,
438			   struct dentry *dentry, const char *symname)
439{
440	struct hfsplus_sb_info *sbi = HFSPLUS_SB(dir->i_sb);
441	struct inode *inode;
442	int res = -ENOMEM;
443
444	mutex_lock(&sbi->vh_mutex);
445	inode = hfsplus_new_inode(dir->i_sb, dir, S_IFLNK | S_IRWXUGO);
446	if (!inode)
447		goto out;
448
449	res = page_symlink(inode, symname, strlen(symname) + 1);
450	if (res)
451		goto out_err;
452
453	res = hfsplus_create_cat(inode->i_ino, dir, &dentry->d_name, inode);
454	if (res)
455		goto out_err;
456
457	res = hfsplus_init_security(inode, dir, &dentry->d_name);
458	if (res == -EOPNOTSUPP)
459		res = 0; /* Operation is not supported. */
460	else if (res) {
461		/* Try to delete anyway without error analysis. */
462		hfsplus_delete_cat(inode->i_ino, dir, &dentry->d_name);
463		goto out_err;
464	}
465
466	hfsplus_instantiate(dentry, inode, inode->i_ino);
467	mark_inode_dirty(inode);
468	goto out;
469
470out_err:
471	clear_nlink(inode);
472	hfsplus_delete_inode(inode);
473	iput(inode);
474out:
475	mutex_unlock(&sbi->vh_mutex);
476	return res;
477}
478
479static int hfsplus_mknod(struct mnt_idmap *idmap, struct inode *dir,
480			 struct dentry *dentry, umode_t mode, dev_t rdev)
481{
482	struct hfsplus_sb_info *sbi = HFSPLUS_SB(dir->i_sb);
483	struct inode *inode;
484	int res = -ENOMEM;
485
486	mutex_lock(&sbi->vh_mutex);
487	inode = hfsplus_new_inode(dir->i_sb, dir, mode);
488	if (!inode)
489		goto out;
490
491	if (S_ISBLK(mode) || S_ISCHR(mode) || S_ISFIFO(mode) || S_ISSOCK(mode))
492		init_special_inode(inode, mode, rdev);
493
494	res = hfsplus_create_cat(inode->i_ino, dir, &dentry->d_name, inode);
495	if (res)
496		goto failed_mknod;
497
498	res = hfsplus_init_security(inode, dir, &dentry->d_name);
499	if (res == -EOPNOTSUPP)
500		res = 0; /* Operation is not supported. */
501	else if (res) {
502		/* Try to delete anyway without error analysis. */
503		hfsplus_delete_cat(inode->i_ino, dir, &dentry->d_name);
504		goto failed_mknod;
505	}
506
507	hfsplus_instantiate(dentry, inode, inode->i_ino);
508	mark_inode_dirty(inode);
509	goto out;
510
511failed_mknod:
512	clear_nlink(inode);
513	hfsplus_delete_inode(inode);
514	iput(inode);
515out:
516	mutex_unlock(&sbi->vh_mutex);
517	return res;
518}
519
520static int hfsplus_create(struct mnt_idmap *idmap, struct inode *dir,
521			  struct dentry *dentry, umode_t mode, bool excl)
522{
523	return hfsplus_mknod(&nop_mnt_idmap, dir, dentry, mode, 0);
524}
525
526static int hfsplus_mkdir(struct mnt_idmap *idmap, struct inode *dir,
527			 struct dentry *dentry, umode_t mode)
528{
529	return hfsplus_mknod(&nop_mnt_idmap, dir, dentry, mode | S_IFDIR, 0);
530}
531
532static int hfsplus_rename(struct mnt_idmap *idmap,
533			  struct inode *old_dir, struct dentry *old_dentry,
534			  struct inode *new_dir, struct dentry *new_dentry,
535			  unsigned int flags)
536{
537	int res;
538
539	if (flags & ~RENAME_NOREPLACE)
540		return -EINVAL;
541
542	/* Unlink destination if it already exists */
543	if (d_really_is_positive(new_dentry)) {
544		if (d_is_dir(new_dentry))
545			res = hfsplus_rmdir(new_dir, new_dentry);
546		else
547			res = hfsplus_unlink(new_dir, new_dentry);
548		if (res)
549			return res;
550	}
551
552	res = hfsplus_rename_cat((u32)(unsigned long)old_dentry->d_fsdata,
553				 old_dir, &old_dentry->d_name,
554				 new_dir, &new_dentry->d_name);
555	if (!res)
556		new_dentry->d_fsdata = old_dentry->d_fsdata;
557	return res;
558}
559
560const struct inode_operations hfsplus_dir_inode_operations = {
561	.lookup			= hfsplus_lookup,
562	.create			= hfsplus_create,
563	.link			= hfsplus_link,
564	.unlink			= hfsplus_unlink,
565	.mkdir			= hfsplus_mkdir,
566	.rmdir			= hfsplus_rmdir,
567	.symlink		= hfsplus_symlink,
568	.mknod			= hfsplus_mknod,
569	.rename			= hfsplus_rename,
570	.getattr		= hfsplus_getattr,
571	.listxattr		= hfsplus_listxattr,
572	.fileattr_get		= hfsplus_fileattr_get,
573	.fileattr_set		= hfsplus_fileattr_set,
574};
575
576const struct file_operations hfsplus_dir_operations = {
577	.fsync		= hfsplus_file_fsync,
578	.read		= generic_read_dir,
579	.iterate_shared	= hfsplus_readdir,
580	.unlocked_ioctl = hfsplus_ioctl,
581	.llseek		= generic_file_llseek,
582	.release	= hfsplus_dir_release,
583};
584