1/* -*- mode: c; c-basic-offset: 8; -*-
2 * vim: noexpandtab sw=8 ts=8 sts=0:
3 *
4 * acl.c
5 *
6 * Copyright (C) 2004, 2008 Oracle.  All rights reserved.
7 *
8 * CREDITS:
9 * Lots of code in this file is copy from linux/fs/ext3/acl.c.
10 * Copyright (C) 2001-2003 Andreas Gruenbacher, <agruen@suse.de>
11 *
12 * This program is free software; you can redistribute it and/or
13 * modify it under the terms of the GNU General Public
14 * License version 2 as published by the Free Software Foundation.
15 *
16 * This program is distributed in the hope that it will be useful,
17 * but WITHOUT ANY WARRANTY; without even the implied warranty of
18 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
19 * General Public License for more details.
20 */
21
22#include <linux/init.h>
23#include <linux/module.h>
24#include <linux/slab.h>
25#include <linux/string.h>
26
27#define MLOG_MASK_PREFIX ML_INODE
28#include <cluster/masklog.h>
29
30#include "ocfs2.h"
31#include "alloc.h"
32#include "dlmglue.h"
33#include "file.h"
34#include "inode.h"
35#include "journal.h"
36#include "ocfs2_fs.h"
37
38#include "xattr.h"
39#include "acl.h"
40
41/*
42 * Convert from xattr value to acl struct.
43 */
44static struct posix_acl *ocfs2_acl_from_xattr(const void *value, size_t size)
45{
46	int n, count;
47	struct posix_acl *acl;
48
49	if (!value)
50		return NULL;
51	if (size < sizeof(struct posix_acl_entry))
52		return ERR_PTR(-EINVAL);
53
54	count = size / sizeof(struct posix_acl_entry);
55	if (count < 0)
56		return ERR_PTR(-EINVAL);
57	if (count == 0)
58		return NULL;
59
60	acl = posix_acl_alloc(count, GFP_NOFS);
61	if (!acl)
62		return ERR_PTR(-ENOMEM);
63	for (n = 0; n < count; n++) {
64		struct ocfs2_acl_entry *entry =
65			(struct ocfs2_acl_entry *)value;
66
67		acl->a_entries[n].e_tag  = le16_to_cpu(entry->e_tag);
68		acl->a_entries[n].e_perm = le16_to_cpu(entry->e_perm);
69		acl->a_entries[n].e_id   = le32_to_cpu(entry->e_id);
70		value += sizeof(struct posix_acl_entry);
71
72	}
73	return acl;
74}
75
76/*
77 * Convert acl struct to xattr value.
78 */
79static void *ocfs2_acl_to_xattr(const struct posix_acl *acl, size_t *size)
80{
81	struct ocfs2_acl_entry *entry = NULL;
82	char *ocfs2_acl;
83	size_t n;
84
85	*size = acl->a_count * sizeof(struct posix_acl_entry);
86
87	ocfs2_acl = kmalloc(*size, GFP_NOFS);
88	if (!ocfs2_acl)
89		return ERR_PTR(-ENOMEM);
90
91	entry = (struct ocfs2_acl_entry *)ocfs2_acl;
92	for (n = 0; n < acl->a_count; n++, entry++) {
93		entry->e_tag  = cpu_to_le16(acl->a_entries[n].e_tag);
94		entry->e_perm = cpu_to_le16(acl->a_entries[n].e_perm);
95		entry->e_id   = cpu_to_le32(acl->a_entries[n].e_id);
96	}
97	return ocfs2_acl;
98}
99
100static struct posix_acl *ocfs2_get_acl_nolock(struct inode *inode,
101					      int type,
102					      struct buffer_head *di_bh)
103{
104	int name_index;
105	char *value = NULL;
106	struct posix_acl *acl;
107	int retval;
108
109	switch (type) {
110	case ACL_TYPE_ACCESS:
111		name_index = OCFS2_XATTR_INDEX_POSIX_ACL_ACCESS;
112		break;
113	case ACL_TYPE_DEFAULT:
114		name_index = OCFS2_XATTR_INDEX_POSIX_ACL_DEFAULT;
115		break;
116	default:
117		return ERR_PTR(-EINVAL);
118	}
119
120	retval = ocfs2_xattr_get_nolock(inode, di_bh, name_index, "", NULL, 0);
121	if (retval > 0) {
122		value = kmalloc(retval, GFP_NOFS);
123		if (!value)
124			return ERR_PTR(-ENOMEM);
125		retval = ocfs2_xattr_get_nolock(inode, di_bh, name_index,
126						"", value, retval);
127	}
128
129	if (retval > 0)
130		acl = ocfs2_acl_from_xattr(value, retval);
131	else if (retval == -ENODATA || retval == 0)
132		acl = NULL;
133	else
134		acl = ERR_PTR(retval);
135
136	kfree(value);
137
138	return acl;
139}
140
141
142/*
143 * Get posix acl.
144 */
145static struct posix_acl *ocfs2_get_acl(struct inode *inode, int type)
146{
147	struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
148	struct buffer_head *di_bh = NULL;
149	struct posix_acl *acl;
150	int ret;
151
152	if (!(osb->s_mount_opt & OCFS2_MOUNT_POSIX_ACL))
153		return NULL;
154
155	ret = ocfs2_inode_lock(inode, &di_bh, 0);
156	if (ret < 0) {
157		mlog_errno(ret);
158		acl = ERR_PTR(ret);
159		return acl;
160	}
161
162	acl = ocfs2_get_acl_nolock(inode, type, di_bh);
163
164	ocfs2_inode_unlock(inode, 0);
165
166	brelse(di_bh);
167
168	return acl;
169}
170
171/*
172 * Helper function to set i_mode in memory and disk. Some call paths
173 * will not have di_bh or a journal handle to pass, in which case it
174 * will create it's own.
175 */
176static int ocfs2_acl_set_mode(struct inode *inode, struct buffer_head *di_bh,
177			      handle_t *handle, umode_t new_mode)
178{
179	int ret, commit_handle = 0;
180	struct ocfs2_dinode *di;
181
182	if (di_bh == NULL) {
183		ret = ocfs2_read_inode_block(inode, &di_bh);
184		if (ret) {
185			mlog_errno(ret);
186			goto out;
187		}
188	} else
189		get_bh(di_bh);
190
191	if (handle == NULL) {
192		handle = ocfs2_start_trans(OCFS2_SB(inode->i_sb),
193					   OCFS2_INODE_UPDATE_CREDITS);
194		if (IS_ERR(handle)) {
195			ret = PTR_ERR(handle);
196			mlog_errno(ret);
197			goto out_brelse;
198		}
199
200		commit_handle = 1;
201	}
202
203	di = (struct ocfs2_dinode *)di_bh->b_data;
204	ret = ocfs2_journal_access_di(handle, INODE_CACHE(inode), di_bh,
205				      OCFS2_JOURNAL_ACCESS_WRITE);
206	if (ret) {
207		mlog_errno(ret);
208		goto out_commit;
209	}
210
211	inode->i_mode = new_mode;
212	inode->i_ctime = CURRENT_TIME;
213	di->i_mode = cpu_to_le16(inode->i_mode);
214	di->i_ctime = cpu_to_le64(inode->i_ctime.tv_sec);
215	di->i_ctime_nsec = cpu_to_le32(inode->i_ctime.tv_nsec);
216
217	ocfs2_journal_dirty(handle, di_bh);
218
219out_commit:
220	if (commit_handle)
221		ocfs2_commit_trans(OCFS2_SB(inode->i_sb), handle);
222out_brelse:
223	brelse(di_bh);
224out:
225	return ret;
226}
227
228/*
229 * Set the access or default ACL of an inode.
230 */
231static int ocfs2_set_acl(handle_t *handle,
232			 struct inode *inode,
233			 struct buffer_head *di_bh,
234			 int type,
235			 struct posix_acl *acl,
236			 struct ocfs2_alloc_context *meta_ac,
237			 struct ocfs2_alloc_context *data_ac)
238{
239	int name_index;
240	void *value = NULL;
241	size_t size = 0;
242	int ret;
243
244	if (S_ISLNK(inode->i_mode))
245		return -EOPNOTSUPP;
246
247	switch (type) {
248	case ACL_TYPE_ACCESS:
249		name_index = OCFS2_XATTR_INDEX_POSIX_ACL_ACCESS;
250		if (acl) {
251			mode_t mode = inode->i_mode;
252			ret = posix_acl_equiv_mode(acl, &mode);
253			if (ret < 0)
254				return ret;
255			else {
256				if (ret == 0)
257					acl = NULL;
258
259				ret = ocfs2_acl_set_mode(inode, di_bh,
260							 handle, mode);
261				if (ret)
262					return ret;
263
264			}
265		}
266		break;
267	case ACL_TYPE_DEFAULT:
268		name_index = OCFS2_XATTR_INDEX_POSIX_ACL_DEFAULT;
269		if (!S_ISDIR(inode->i_mode))
270			return acl ? -EACCES : 0;
271		break;
272	default:
273		return -EINVAL;
274	}
275
276	if (acl) {
277		value = ocfs2_acl_to_xattr(acl, &size);
278		if (IS_ERR(value))
279			return (int)PTR_ERR(value);
280	}
281
282	if (handle)
283		ret = ocfs2_xattr_set_handle(handle, inode, di_bh, name_index,
284					     "", value, size, 0,
285					     meta_ac, data_ac);
286	else
287		ret = ocfs2_xattr_set(inode, name_index, "", value, size, 0);
288
289	kfree(value);
290
291	return ret;
292}
293
294int ocfs2_check_acl(struct inode *inode, int mask)
295{
296	struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
297	struct buffer_head *di_bh = NULL;
298	struct posix_acl *acl;
299	int ret = -EAGAIN;
300
301	if (!(osb->s_mount_opt & OCFS2_MOUNT_POSIX_ACL))
302		return ret;
303
304	ret = ocfs2_read_inode_block(inode, &di_bh);
305	if (ret < 0) {
306		mlog_errno(ret);
307		return ret;
308	}
309
310	acl = ocfs2_get_acl_nolock(inode, ACL_TYPE_ACCESS, di_bh);
311
312	brelse(di_bh);
313
314	if (IS_ERR(acl)) {
315		mlog_errno(PTR_ERR(acl));
316		return PTR_ERR(acl);
317	}
318	if (acl) {
319		ret = posix_acl_permission(inode, acl, mask);
320		posix_acl_release(acl);
321		return ret;
322	}
323
324	return -EAGAIN;
325}
326
327int ocfs2_acl_chmod(struct inode *inode)
328{
329	struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
330	struct posix_acl *acl, *clone;
331	int ret;
332
333	if (S_ISLNK(inode->i_mode))
334		return -EOPNOTSUPP;
335
336	if (!(osb->s_mount_opt & OCFS2_MOUNT_POSIX_ACL))
337		return 0;
338
339	acl = ocfs2_get_acl(inode, ACL_TYPE_ACCESS);
340	if (IS_ERR(acl) || !acl)
341		return PTR_ERR(acl);
342	clone = posix_acl_clone(acl, GFP_KERNEL);
343	posix_acl_release(acl);
344	if (!clone)
345		return -ENOMEM;
346	ret = posix_acl_chmod_masq(clone, inode->i_mode);
347	if (!ret)
348		ret = ocfs2_set_acl(NULL, inode, NULL, ACL_TYPE_ACCESS,
349				    clone, NULL, NULL);
350	posix_acl_release(clone);
351	return ret;
352}
353
354/*
355 * Initialize the ACLs of a new inode. If parent directory has default ACL,
356 * then clone to new inode. Called from ocfs2_mknod.
357 */
358int ocfs2_init_acl(handle_t *handle,
359		   struct inode *inode,
360		   struct inode *dir,
361		   struct buffer_head *di_bh,
362		   struct buffer_head *dir_bh,
363		   struct ocfs2_alloc_context *meta_ac,
364		   struct ocfs2_alloc_context *data_ac)
365{
366	struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
367	struct posix_acl *acl = NULL;
368	int ret = 0, ret2;
369	mode_t mode;
370
371	if (!S_ISLNK(inode->i_mode)) {
372		if (osb->s_mount_opt & OCFS2_MOUNT_POSIX_ACL) {
373			acl = ocfs2_get_acl_nolock(dir, ACL_TYPE_DEFAULT,
374						   dir_bh);
375			if (IS_ERR(acl))
376				return PTR_ERR(acl);
377		}
378		if (!acl) {
379			mode = inode->i_mode & ~current_umask();
380			ret = ocfs2_acl_set_mode(inode, di_bh, handle, mode);
381			if (ret) {
382				mlog_errno(ret);
383				goto cleanup;
384			}
385		}
386	}
387	if ((osb->s_mount_opt & OCFS2_MOUNT_POSIX_ACL) && acl) {
388		struct posix_acl *clone;
389
390		if (S_ISDIR(inode->i_mode)) {
391			ret = ocfs2_set_acl(handle, inode, di_bh,
392					    ACL_TYPE_DEFAULT, acl,
393					    meta_ac, data_ac);
394			if (ret)
395				goto cleanup;
396		}
397		clone = posix_acl_clone(acl, GFP_NOFS);
398		ret = -ENOMEM;
399		if (!clone)
400			goto cleanup;
401
402		mode = inode->i_mode;
403		ret = posix_acl_create_masq(clone, &mode);
404		if (ret >= 0) {
405			ret2 = ocfs2_acl_set_mode(inode, di_bh, handle, mode);
406			if (ret2) {
407				mlog_errno(ret2);
408				ret = ret2;
409				goto cleanup;
410			}
411			if (ret > 0) {
412				ret = ocfs2_set_acl(handle, inode,
413						    di_bh, ACL_TYPE_ACCESS,
414						    clone, meta_ac, data_ac);
415			}
416		}
417		posix_acl_release(clone);
418	}
419cleanup:
420	posix_acl_release(acl);
421	return ret;
422}
423
424static size_t ocfs2_xattr_list_acl_access(struct dentry *dentry,
425					  char *list,
426					  size_t list_len,
427					  const char *name,
428					  size_t name_len,
429					  int type)
430{
431	struct ocfs2_super *osb = OCFS2_SB(dentry->d_sb);
432	const size_t size = sizeof(POSIX_ACL_XATTR_ACCESS);
433
434	if (!(osb->s_mount_opt & OCFS2_MOUNT_POSIX_ACL))
435		return 0;
436
437	if (list && size <= list_len)
438		memcpy(list, POSIX_ACL_XATTR_ACCESS, size);
439	return size;
440}
441
442static size_t ocfs2_xattr_list_acl_default(struct dentry *dentry,
443					   char *list,
444					   size_t list_len,
445					   const char *name,
446					   size_t name_len,
447					   int type)
448{
449	struct ocfs2_super *osb = OCFS2_SB(dentry->d_sb);
450	const size_t size = sizeof(POSIX_ACL_XATTR_DEFAULT);
451
452	if (!(osb->s_mount_opt & OCFS2_MOUNT_POSIX_ACL))
453		return 0;
454
455	if (list && size <= list_len)
456		memcpy(list, POSIX_ACL_XATTR_DEFAULT, size);
457	return size;
458}
459
460static int ocfs2_xattr_get_acl(struct dentry *dentry, const char *name,
461		void *buffer, size_t size, int type)
462{
463	struct ocfs2_super *osb = OCFS2_SB(dentry->d_sb);
464	struct posix_acl *acl;
465	int ret;
466
467	if (strcmp(name, "") != 0)
468		return -EINVAL;
469	if (!(osb->s_mount_opt & OCFS2_MOUNT_POSIX_ACL))
470		return -EOPNOTSUPP;
471
472	acl = ocfs2_get_acl(dentry->d_inode, type);
473	if (IS_ERR(acl))
474		return PTR_ERR(acl);
475	if (acl == NULL)
476		return -ENODATA;
477	ret = posix_acl_to_xattr(acl, buffer, size);
478	posix_acl_release(acl);
479
480	return ret;
481}
482
483static int ocfs2_xattr_set_acl(struct dentry *dentry, const char *name,
484		const void *value, size_t size, int flags, int type)
485{
486	struct inode *inode = dentry->d_inode;
487	struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
488	struct posix_acl *acl;
489	int ret = 0;
490
491	if (strcmp(name, "") != 0)
492		return -EINVAL;
493	if (!(osb->s_mount_opt & OCFS2_MOUNT_POSIX_ACL))
494		return -EOPNOTSUPP;
495
496	if (!is_owner_or_cap(inode))
497		return -EPERM;
498
499	if (value) {
500		acl = posix_acl_from_xattr(value, size);
501		if (IS_ERR(acl))
502			return PTR_ERR(acl);
503		else if (acl) {
504			ret = posix_acl_valid(acl);
505			if (ret)
506				goto cleanup;
507		}
508	} else
509		acl = NULL;
510
511	ret = ocfs2_set_acl(NULL, inode, NULL, type, acl, NULL, NULL);
512
513cleanup:
514	posix_acl_release(acl);
515	return ret;
516}
517
518const struct xattr_handler ocfs2_xattr_acl_access_handler = {
519	.prefix	= POSIX_ACL_XATTR_ACCESS,
520	.flags	= ACL_TYPE_ACCESS,
521	.list	= ocfs2_xattr_list_acl_access,
522	.get	= ocfs2_xattr_get_acl,
523	.set	= ocfs2_xattr_set_acl,
524};
525
526const struct xattr_handler ocfs2_xattr_acl_default_handler = {
527	.prefix	= POSIX_ACL_XATTR_DEFAULT,
528	.flags	= ACL_TYPE_DEFAULT,
529	.list	= ocfs2_xattr_list_acl_default,
530	.get	= ocfs2_xattr_get_acl,
531	.set	= ocfs2_xattr_set_acl,
532};
533