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#include <cluster/masklog.h>
28
29#include "ocfs2.h"
30#include "alloc.h"
31#include "dlmglue.h"
32#include "file.h"
33#include "inode.h"
34#include "journal.h"
35#include "ocfs2_fs.h"
36
37#include "xattr.h"
38#include "acl.h"
39
40/*
41 * Convert from xattr value to acl struct.
42 */
43static struct posix_acl *ocfs2_acl_from_xattr(const void *value, size_t size)
44{
45	int n, count;
46	struct posix_acl *acl;
47
48	if (!value)
49		return NULL;
50	if (size < sizeof(struct posix_acl_entry))
51		return ERR_PTR(-EINVAL);
52
53	count = size / sizeof(struct posix_acl_entry);
54
55	acl = posix_acl_alloc(count, GFP_NOFS);
56	if (!acl)
57		return ERR_PTR(-ENOMEM);
58	for (n = 0; n < count; n++) {
59		struct ocfs2_acl_entry *entry =
60			(struct ocfs2_acl_entry *)value;
61
62		acl->a_entries[n].e_tag  = le16_to_cpu(entry->e_tag);
63		acl->a_entries[n].e_perm = le16_to_cpu(entry->e_perm);
64		switch(acl->a_entries[n].e_tag) {
65		case ACL_USER:
66			acl->a_entries[n].e_uid =
67				make_kuid(&init_user_ns,
68					  le32_to_cpu(entry->e_id));
69			break;
70		case ACL_GROUP:
71			acl->a_entries[n].e_gid =
72				make_kgid(&init_user_ns,
73					  le32_to_cpu(entry->e_id));
74			break;
75		default:
76			break;
77		}
78		value += sizeof(struct posix_acl_entry);
79
80	}
81	return acl;
82}
83
84/*
85 * Convert acl struct to xattr value.
86 */
87static void *ocfs2_acl_to_xattr(const struct posix_acl *acl, size_t *size)
88{
89	struct ocfs2_acl_entry *entry = NULL;
90	char *ocfs2_acl;
91	size_t n;
92
93	*size = acl->a_count * sizeof(struct posix_acl_entry);
94
95	ocfs2_acl = kmalloc(*size, GFP_NOFS);
96	if (!ocfs2_acl)
97		return ERR_PTR(-ENOMEM);
98
99	entry = (struct ocfs2_acl_entry *)ocfs2_acl;
100	for (n = 0; n < acl->a_count; n++, entry++) {
101		entry->e_tag  = cpu_to_le16(acl->a_entries[n].e_tag);
102		entry->e_perm = cpu_to_le16(acl->a_entries[n].e_perm);
103		switch(acl->a_entries[n].e_tag) {
104		case ACL_USER:
105			entry->e_id = cpu_to_le32(
106				from_kuid(&init_user_ns,
107					  acl->a_entries[n].e_uid));
108			break;
109		case ACL_GROUP:
110			entry->e_id = cpu_to_le32(
111				from_kgid(&init_user_ns,
112					  acl->a_entries[n].e_gid));
113			break;
114		default:
115			entry->e_id = cpu_to_le32(ACL_UNDEFINED_ID);
116			break;
117		}
118	}
119	return ocfs2_acl;
120}
121
122static struct posix_acl *ocfs2_get_acl_nolock(struct inode *inode,
123					      int type,
124					      struct buffer_head *di_bh)
125{
126	int name_index;
127	char *value = NULL;
128	struct posix_acl *acl;
129	int retval;
130
131	switch (type) {
132	case ACL_TYPE_ACCESS:
133		name_index = OCFS2_XATTR_INDEX_POSIX_ACL_ACCESS;
134		break;
135	case ACL_TYPE_DEFAULT:
136		name_index = OCFS2_XATTR_INDEX_POSIX_ACL_DEFAULT;
137		break;
138	default:
139		return ERR_PTR(-EINVAL);
140	}
141
142	retval = ocfs2_xattr_get_nolock(inode, di_bh, name_index, "", NULL, 0);
143	if (retval > 0) {
144		value = kmalloc(retval, GFP_NOFS);
145		if (!value)
146			return ERR_PTR(-ENOMEM);
147		retval = ocfs2_xattr_get_nolock(inode, di_bh, name_index,
148						"", value, retval);
149	}
150
151	if (retval > 0)
152		acl = ocfs2_acl_from_xattr(value, retval);
153	else if (retval == -ENODATA || retval == 0)
154		acl = NULL;
155	else
156		acl = ERR_PTR(retval);
157
158	kfree(value);
159
160	return acl;
161}
162
163/*
164 * Helper function to set i_mode in memory and disk. Some call paths
165 * will not have di_bh or a journal handle to pass, in which case it
166 * will create it's own.
167 */
168static int ocfs2_acl_set_mode(struct inode *inode, struct buffer_head *di_bh,
169			      handle_t *handle, umode_t new_mode)
170{
171	int ret, commit_handle = 0;
172	struct ocfs2_dinode *di;
173
174	if (di_bh == NULL) {
175		ret = ocfs2_read_inode_block(inode, &di_bh);
176		if (ret) {
177			mlog_errno(ret);
178			goto out;
179		}
180	} else
181		get_bh(di_bh);
182
183	if (handle == NULL) {
184		handle = ocfs2_start_trans(OCFS2_SB(inode->i_sb),
185					   OCFS2_INODE_UPDATE_CREDITS);
186		if (IS_ERR(handle)) {
187			ret = PTR_ERR(handle);
188			mlog_errno(ret);
189			goto out_brelse;
190		}
191
192		commit_handle = 1;
193	}
194
195	di = (struct ocfs2_dinode *)di_bh->b_data;
196	ret = ocfs2_journal_access_di(handle, INODE_CACHE(inode), di_bh,
197				      OCFS2_JOURNAL_ACCESS_WRITE);
198	if (ret) {
199		mlog_errno(ret);
200		goto out_commit;
201	}
202
203	inode->i_mode = new_mode;
204	inode->i_ctime = CURRENT_TIME;
205	di->i_mode = cpu_to_le16(inode->i_mode);
206	di->i_ctime = cpu_to_le64(inode->i_ctime.tv_sec);
207	di->i_ctime_nsec = cpu_to_le32(inode->i_ctime.tv_nsec);
208	ocfs2_update_inode_fsync_trans(handle, inode, 0);
209
210	ocfs2_journal_dirty(handle, di_bh);
211
212out_commit:
213	if (commit_handle)
214		ocfs2_commit_trans(OCFS2_SB(inode->i_sb), handle);
215out_brelse:
216	brelse(di_bh);
217out:
218	return ret;
219}
220
221/*
222 * Set the access or default ACL of an inode.
223 */
224int ocfs2_set_acl(handle_t *handle,
225			 struct inode *inode,
226			 struct buffer_head *di_bh,
227			 int type,
228			 struct posix_acl *acl,
229			 struct ocfs2_alloc_context *meta_ac,
230			 struct ocfs2_alloc_context *data_ac)
231{
232	int name_index;
233	void *value = NULL;
234	size_t size = 0;
235	int ret;
236
237	if (S_ISLNK(inode->i_mode))
238		return -EOPNOTSUPP;
239
240	switch (type) {
241	case ACL_TYPE_ACCESS:
242		name_index = OCFS2_XATTR_INDEX_POSIX_ACL_ACCESS;
243		if (acl) {
244			umode_t mode = inode->i_mode;
245			ret = posix_acl_equiv_mode(acl, &mode);
246			if (ret < 0)
247				return ret;
248
249			if (ret == 0)
250				acl = NULL;
251
252			ret = ocfs2_acl_set_mode(inode, di_bh,
253						 handle, mode);
254			if (ret)
255				return ret;
256		}
257		break;
258	case ACL_TYPE_DEFAULT:
259		name_index = OCFS2_XATTR_INDEX_POSIX_ACL_DEFAULT;
260		if (!S_ISDIR(inode->i_mode))
261			return acl ? -EACCES : 0;
262		break;
263	default:
264		return -EINVAL;
265	}
266
267	if (acl) {
268		value = ocfs2_acl_to_xattr(acl, &size);
269		if (IS_ERR(value))
270			return (int)PTR_ERR(value);
271	}
272
273	if (handle)
274		ret = ocfs2_xattr_set_handle(handle, inode, di_bh, name_index,
275					     "", value, size, 0,
276					     meta_ac, data_ac);
277	else
278		ret = ocfs2_xattr_set(inode, name_index, "", value, size, 0);
279
280	kfree(value);
281
282	return ret;
283}
284
285int ocfs2_iop_set_acl(struct inode *inode, struct posix_acl *acl, int type)
286{
287	return ocfs2_set_acl(NULL, inode, NULL, type, acl, NULL, NULL);
288}
289
290struct posix_acl *ocfs2_iop_get_acl(struct inode *inode, int type)
291{
292	struct ocfs2_super *osb;
293	struct buffer_head *di_bh = NULL;
294	struct posix_acl *acl;
295	int ret = -EAGAIN;
296
297	osb = OCFS2_SB(inode->i_sb);
298	if (!(osb->s_mount_opt & OCFS2_MOUNT_POSIX_ACL))
299		return NULL;
300
301	ret = ocfs2_read_inode_block(inode, &di_bh);
302	if (ret < 0)
303		return ERR_PTR(ret);
304
305	acl = ocfs2_get_acl_nolock(inode, type, di_bh);
306
307	brelse(di_bh);
308
309	return acl;
310}
311
312int ocfs2_acl_chmod(struct inode *inode, struct buffer_head *bh)
313{
314	struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
315	struct posix_acl *acl;
316	int ret;
317
318	if (S_ISLNK(inode->i_mode))
319		return -EOPNOTSUPP;
320
321	if (!(osb->s_mount_opt & OCFS2_MOUNT_POSIX_ACL))
322		return 0;
323
324	acl = ocfs2_get_acl_nolock(inode, ACL_TYPE_ACCESS, bh);
325	if (IS_ERR(acl) || !acl)
326		return PTR_ERR(acl);
327	ret = __posix_acl_chmod(&acl, GFP_KERNEL, inode->i_mode);
328	if (ret)
329		return ret;
330	ret = ocfs2_set_acl(NULL, inode, NULL, ACL_TYPE_ACCESS,
331			    acl, NULL, NULL);
332	posix_acl_release(acl);
333	return ret;
334}
335
336/*
337 * Initialize the ACLs of a new inode. If parent directory has default ACL,
338 * then clone to new inode. Called from ocfs2_mknod.
339 */
340int ocfs2_init_acl(handle_t *handle,
341		   struct inode *inode,
342		   struct inode *dir,
343		   struct buffer_head *di_bh,
344		   struct buffer_head *dir_bh,
345		   struct ocfs2_alloc_context *meta_ac,
346		   struct ocfs2_alloc_context *data_ac)
347{
348	struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
349	struct posix_acl *acl = NULL;
350	int ret = 0, ret2;
351	umode_t mode;
352
353	if (!S_ISLNK(inode->i_mode)) {
354		if (osb->s_mount_opt & OCFS2_MOUNT_POSIX_ACL) {
355			acl = ocfs2_get_acl_nolock(dir, ACL_TYPE_DEFAULT,
356						   dir_bh);
357			if (IS_ERR(acl))
358				return PTR_ERR(acl);
359		}
360		if (!acl) {
361			mode = inode->i_mode & ~current_umask();
362			ret = ocfs2_acl_set_mode(inode, di_bh, handle, mode);
363			if (ret) {
364				mlog_errno(ret);
365				goto cleanup;
366			}
367		}
368	}
369	if ((osb->s_mount_opt & OCFS2_MOUNT_POSIX_ACL) && acl) {
370		if (S_ISDIR(inode->i_mode)) {
371			ret = ocfs2_set_acl(handle, inode, di_bh,
372					    ACL_TYPE_DEFAULT, acl,
373					    meta_ac, data_ac);
374			if (ret)
375				goto cleanup;
376		}
377		mode = inode->i_mode;
378		ret = __posix_acl_create(&acl, GFP_NOFS, &mode);
379		if (ret < 0)
380			return ret;
381
382		ret2 = ocfs2_acl_set_mode(inode, di_bh, handle, mode);
383		if (ret2) {
384			mlog_errno(ret2);
385			ret = ret2;
386			goto cleanup;
387		}
388		if (ret > 0) {
389			ret = ocfs2_set_acl(handle, inode,
390					    di_bh, ACL_TYPE_ACCESS,
391					    acl, meta_ac, data_ac);
392		}
393	}
394cleanup:
395	posix_acl_release(acl);
396	return ret;
397}
398