acl.c 6.08 KB
Newer Older
David Teigland's avatar
David Teigland committed
1
2
/*
 * Copyright (C) Sistina Software, Inc.  1997-2003 All rights reserved.
3
 * Copyright (C) 2004-2006 Red Hat, Inc.  All rights reserved.
David Teigland's avatar
David Teigland committed
4
5
6
 *
 * This copyrighted material is made available to anyone wishing to use,
 * modify, copy, or redistribute it subject to the terms and conditions
7
 * of the GNU General Public License version 2.
David Teigland's avatar
David Teigland committed
8
9
10
11
12
13
14
15
16
 */

#include <linux/sched.h>
#include <linux/slab.h>
#include <linux/spinlock.h>
#include <linux/completion.h>
#include <linux/buffer_head.h>
#include <linux/posix_acl.h>
#include <linux/posix_acl_xattr.h>
17
#include <linux/gfs2_ondisk.h>
18
#include <linux/lm_interface.h>
David Teigland's avatar
David Teigland committed
19
20

#include "gfs2.h"
21
#include "incore.h"
David Teigland's avatar
David Teigland committed
22
23
24
25
26
27
28
#include "acl.h"
#include "eaops.h"
#include "eattr.h"
#include "glock.h"
#include "inode.h"
#include "meta_io.h"
#include "trans.h"
29
#include "util.h"
David Teigland's avatar
David Teigland committed
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67

#define ACL_ACCESS 1
#define ACL_DEFAULT 0

int gfs2_acl_validate_set(struct gfs2_inode *ip, int access,
		      struct gfs2_ea_request *er,
		      int *remove, mode_t *mode)
{
	struct posix_acl *acl;
	int error;

	error = gfs2_acl_validate_remove(ip, access);
	if (error)
		return error;

	if (!er->er_data)
		return -EINVAL;

	acl = posix_acl_from_xattr(er->er_data, er->er_data_len);
	if (IS_ERR(acl))
		return PTR_ERR(acl);
	if (!acl) {
		*remove = 1;
		return 0;
	}

	error = posix_acl_valid(acl);
	if (error)
		goto out;

	if (access) {
		error = posix_acl_equiv_mode(acl, mode);
		if (!error)
			*remove = 1;
		else if (error > 0)
			error = 0;
	}

68
out:
David Teigland's avatar
David Teigland committed
69
70
71
72
73
74
	posix_acl_release(acl);
	return error;
}

int gfs2_acl_validate_remove(struct gfs2_inode *ip, int access)
{
75
	if (!GFS2_SB(&ip->i_inode)->sd_args.ar_posix_acl)
David Teigland's avatar
David Teigland committed
76
		return -EOPNOTSUPP;
77
	if (current->fsuid != ip->i_inode.i_uid && !capable(CAP_FOWNER))
David Teigland's avatar
David Teigland committed
78
		return -EPERM;
79
	if (S_ISLNK(ip->i_inode.i_mode))
David Teigland's avatar
David Teigland committed
80
		return -EOPNOTSUPP;
81
	if (!access && !S_ISDIR(ip->i_inode.i_mode))
David Teigland's avatar
David Teigland committed
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
		return -EACCES;

	return 0;
}

static int acl_get(struct gfs2_inode *ip, int access, struct posix_acl **acl,
		   struct gfs2_ea_location *el, char **data, unsigned int *len)
{
	struct gfs2_ea_request er;
	struct gfs2_ea_location el_this;
	int error;

	if (!ip->i_di.di_eattr)
		return 0;

	memset(&er, 0, sizeof(struct gfs2_ea_request));
	if (access) {
		er.er_name = GFS2_POSIX_ACL_ACCESS;
		er.er_name_len = GFS2_POSIX_ACL_ACCESS_LEN;
	} else {
		er.er_name = GFS2_POSIX_ACL_DEFAULT;
		er.er_name_len = GFS2_POSIX_ACL_DEFAULT_LEN;
	}
	er.er_type = GFS2_EATYPE_SYS;

	if (!el)
		el = &el_this;

	error = gfs2_ea_find(ip, &er, el);
	if (error)
		return error;
	if (!el->el_ea)
		return 0;
	if (!GFS2_EA_DATA_LEN(el->el_ea))
		goto out;

	er.er_data_len = GFS2_EA_DATA_LEN(el->el_ea);
	er.er_data = kmalloc(er.er_data_len, GFP_KERNEL);
	error = -ENOMEM;
	if (!er.er_data)
		goto out;

	error = gfs2_ea_get_copy(ip, el, er.er_data);
	if (error)
		goto out_kfree;

	if (acl) {
		*acl = posix_acl_from_xattr(er.er_data, er.er_data_len);
		if (IS_ERR(*acl))
			error = PTR_ERR(*acl);
	}

134
out_kfree:
David Teigland's avatar
David Teigland committed
135
136
137
138
139
140
	if (error || !data)
		kfree(er.er_data);
	else {
		*data = er.er_data;
		*len = er.er_data_len;
	}
141
out:
David Teigland's avatar
David Teigland committed
142
143
144
145
146
147
	if (error || el == &el_this)
		brelse(el->el_bh);
	return error;
}

/**
148
 * gfs2_check_acl - Check an ACL to see if we're allowed to do something
David Teigland's avatar
David Teigland committed
149
150
151
152
153
154
 * @inode: the file we want to do something to
 * @mask: what we want to do
 *
 * Returns: errno
 */

155
int gfs2_check_acl(struct inode *inode, int mask)
David Teigland's avatar
David Teigland committed
156
157
158
159
{
	struct posix_acl *acl = NULL;
	int error;

160
	error = acl_get(GFS2_I(inode), ACL_ACCESS, &acl, NULL, NULL, NULL);
David Teigland's avatar
David Teigland committed
161
162
163
164
165
166
167
168
169
170
171
172
173
174
	if (error)
		return error;

	if (acl) {
		error = posix_acl_permission(inode, acl, mask);
		posix_acl_release(acl);
		return error;
	}

	return -EAGAIN;
}

static int munge_mode(struct gfs2_inode *ip, mode_t mode)
{
175
	struct gfs2_sbd *sdp = GFS2_SB(&ip->i_inode);
David Teigland's avatar
David Teigland committed
176
177
178
179
180
181
182
183
184
185
	struct buffer_head *dibh;
	int error;

	error = gfs2_trans_begin(sdp, RES_DINODE, 0);
	if (error)
		return error;

	error = gfs2_meta_inode_buffer(ip, &dibh);
	if (!error) {
		gfs2_assert_withdraw(sdp,
186
187
				(ip->i_inode.i_mode & S_IFMT) == (mode & S_IFMT));
		ip->i_inode.i_mode = mode;
188
		gfs2_trans_add_bh(ip->i_gl, dibh, 1);
189
		gfs2_dinode_out(ip, dibh->b_data);
David Teigland's avatar
David Teigland committed
190
191
192
193
194
195
196
197
198
199
		brelse(dibh);
	}

	gfs2_trans_end(sdp);

	return 0;
}

int gfs2_acl_create(struct gfs2_inode *dip, struct gfs2_inode *ip)
{
200
	struct gfs2_sbd *sdp = GFS2_SB(&dip->i_inode);
David Teigland's avatar
David Teigland committed
201
202
	struct posix_acl *acl = NULL, *clone;
	struct gfs2_ea_request er;
203
	mode_t mode = ip->i_inode.i_mode;
David Teigland's avatar
David Teigland committed
204
205
206
207
	int error;

	if (!sdp->sd_args.ar_posix_acl)
		return 0;
208
	if (S_ISLNK(ip->i_inode.i_mode))
David Teigland's avatar
David Teigland committed
209
210
211
212
213
214
215
216
217
218
219
		return 0;

	memset(&er, 0, sizeof(struct gfs2_ea_request));
	er.er_type = GFS2_EATYPE_SYS;

	error = acl_get(dip, ACL_DEFAULT, &acl, NULL,
			&er.er_data, &er.er_data_len);
	if (error)
		return error;
	if (!acl) {
		mode &= ~current->fs->umask;
220
		if (mode != ip->i_inode.i_mode)
David Teigland's avatar
David Teigland committed
221
222
223
224
225
226
227
228
229
230
231
			error = munge_mode(ip, mode);
		return error;
	}

	clone = posix_acl_clone(acl, GFP_KERNEL);
	error = -ENOMEM;
	if (!clone)
		goto out;
	posix_acl_release(acl);
	acl = clone;

232
	if (S_ISDIR(ip->i_inode.i_mode)) {
David Teigland's avatar
David Teigland committed
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
		er.er_name = GFS2_POSIX_ACL_DEFAULT;
		er.er_name_len = GFS2_POSIX_ACL_DEFAULT_LEN;
		error = gfs2_system_eaops.eo_set(ip, &er);
		if (error)
			goto out;
	}

	error = posix_acl_create_masq(acl, &mode);
	if (error < 0)
		goto out;
	if (error > 0) {
		er.er_name = GFS2_POSIX_ACL_ACCESS;
		er.er_name_len = GFS2_POSIX_ACL_ACCESS_LEN;
		posix_acl_to_xattr(acl, er.er_data, er.er_data_len);
		er.er_mode = mode;
		er.er_flags = GFS2_ERF_MODE;
		error = gfs2_system_eaops.eo_set(ip, &er);
		if (error)
			goto out;
	} else
		munge_mode(ip, mode);

255
out:
David Teigland's avatar
David Teigland committed
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
	posix_acl_release(acl);
	kfree(er.er_data);
	return error;
}

int gfs2_acl_chmod(struct gfs2_inode *ip, struct iattr *attr)
{
	struct posix_acl *acl = NULL, *clone;
	struct gfs2_ea_location el;
	char *data;
	unsigned int len;
	int error;

	error = acl_get(ip, ACL_ACCESS, &acl, &el, &data, &len);
	if (error)
		return error;
	if (!acl)
		return gfs2_setattr_simple(ip, attr);

	clone = posix_acl_clone(acl, GFP_KERNEL);
	error = -ENOMEM;
	if (!clone)
		goto out;
	posix_acl_release(acl);
	acl = clone;

	error = posix_acl_chmod_masq(acl, attr->ia_mode);
	if (!error) {
		posix_acl_to_xattr(acl, data, len);
		error = gfs2_ea_acl_chmod(ip, &el, attr, data);
	}

288
out:
David Teigland's avatar
David Teigland committed
289
290
291
292
293
294
	posix_acl_release(acl);
	brelse(el.el_bh);
	kfree(data);
	return error;
}