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1/*
2 * Copyright (C) 2008 Christoph Hellwig.
3 * Portions Copyright (C) 2000-2008 Silicon Graphics, Inc.
4 *
5 * This program is free software; you can redistribute it and/or
6 * modify it under the terms of the GNU General Public License as
7 * published by the Free Software Foundation.
8 *
9 * This program is distributed in the hope that it would be useful,
10 * but WITHOUT ANY WARRANTY; without even the implied warranty of
11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
12 * GNU General Public License for more details.
13 *
14 * You should have received a copy of the GNU General Public License
15 * along with this program; if not, write the Free Software Foundation,
16 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
17 */
18
19#include "xfs.h"
20#include "xfs_format.h"
21#include "xfs_log_format.h"
22#include "xfs_trans_resv.h"
23#include "xfs_mount.h"
24#include "xfs_da_format.h"
25#include "xfs_inode.h"
26#include "xfs_attr.h"
27#include "xfs_attr_leaf.h"
28#include "xfs_acl.h"
29
30#include <linux/posix_acl_xattr.h>
31#include <linux/xattr.h>
32
33
34static int
35xfs_xattr_get(const struct xattr_handler *handler, struct dentry *unused,
36 struct inode *inode, const char *name, void *value, size_t size)
37{
38 int xflags = handler->flags;
39 struct xfs_inode *ip = XFS_I(inode);
40 int error, asize = size;
41
42 /* Convert Linux syscall to XFS internal ATTR flags */
43 if (!size) {
44 xflags |= ATTR_KERNOVAL;
45 value = NULL;
46 }
47
48 error = xfs_attr_get(ip, (unsigned char *)name, value, &asize, xflags);
49 if (error)
50 return error;
51 return asize;
52}
53
54void
55xfs_forget_acl(
56 struct inode *inode,
57 const char *name,
58 int xflags)
59{
60 /*
61 * Invalidate any cached ACLs if the user has bypassed the ACL
62 * interface. We don't validate the content whatsoever so it is caller
63 * responsibility to provide data in valid format and ensure i_mode is
64 * consistent.
65 */
66 if (xflags & ATTR_ROOT) {
67#ifdef CONFIG_XFS_POSIX_ACL
68 if (!strcmp(name, SGI_ACL_FILE))
69 forget_cached_acl(inode, ACL_TYPE_ACCESS);
70 else if (!strcmp(name, SGI_ACL_DEFAULT))
71 forget_cached_acl(inode, ACL_TYPE_DEFAULT);
72#endif
73 }
74}
75
76static int
77xfs_xattr_set(const struct xattr_handler *handler, struct dentry *unused,
78 struct inode *inode, const char *name, const void *value,
79 size_t size, int flags)
80{
81 int xflags = handler->flags;
82 struct xfs_inode *ip = XFS_I(inode);
83 int error;
84
85 /* Convert Linux syscall to XFS internal ATTR flags */
86 if (flags & XATTR_CREATE)
87 xflags |= ATTR_CREATE;
88 if (flags & XATTR_REPLACE)
89 xflags |= ATTR_REPLACE;
90
91 if (!value)
92 return xfs_attr_remove(ip, (unsigned char *)name, xflags);
93 error = xfs_attr_set(ip, (unsigned char *)name,
94 (void *)value, size, xflags);
95 if (!error)
96 xfs_forget_acl(inode, name, xflags);
97
98 return error;
99}
100
101static const struct xattr_handler xfs_xattr_user_handler = {
102 .prefix = XATTR_USER_PREFIX,
103 .flags = 0, /* no flags implies user namespace */
104 .get = xfs_xattr_get,
105 .set = xfs_xattr_set,
106};
107
108static const struct xattr_handler xfs_xattr_trusted_handler = {
109 .prefix = XATTR_TRUSTED_PREFIX,
110 .flags = ATTR_ROOT,
111 .get = xfs_xattr_get,
112 .set = xfs_xattr_set,
113};
114
115static const struct xattr_handler xfs_xattr_security_handler = {
116 .prefix = XATTR_SECURITY_PREFIX,
117 .flags = ATTR_SECURE,
118 .get = xfs_xattr_get,
119 .set = xfs_xattr_set,
120};
121
122const struct xattr_handler *xfs_xattr_handlers[] = {
123 &xfs_xattr_user_handler,
124 &xfs_xattr_trusted_handler,
125 &xfs_xattr_security_handler,
126#ifdef CONFIG_XFS_POSIX_ACL
127 &posix_acl_access_xattr_handler,
128 &posix_acl_default_xattr_handler,
129#endif
130 NULL
131};
132
133static void
134__xfs_xattr_put_listent(
135 struct xfs_attr_list_context *context,
136 char *prefix,
137 int prefix_len,
138 unsigned char *name,
139 int namelen)
140{
141 char *offset;
142 int arraytop;
143
144 if (!context->alist)
145 goto compute_size;
146
147 arraytop = context->count + prefix_len + namelen + 1;
148 if (arraytop > context->firstu) {
149 context->count = -1; /* insufficient space */
150 context->seen_enough = 1;
151 return;
152 }
153 offset = (char *)context->alist + context->count;
154 strncpy(offset, prefix, prefix_len);
155 offset += prefix_len;
156 strncpy(offset, (char *)name, namelen); /* real name */
157 offset += namelen;
158 *offset = '\0';
159
160compute_size:
161 context->count += prefix_len + namelen + 1;
162 return;
163}
164
165static void
166xfs_xattr_put_listent(
167 struct xfs_attr_list_context *context,
168 int flags,
169 unsigned char *name,
170 int namelen,
171 int valuelen)
172{
173 char *prefix;
174 int prefix_len;
175
176 ASSERT(context->count >= 0);
177
178 if (flags & XFS_ATTR_ROOT) {
179#ifdef CONFIG_XFS_POSIX_ACL
180 if (namelen == SGI_ACL_FILE_SIZE &&
181 strncmp(name, SGI_ACL_FILE,
182 SGI_ACL_FILE_SIZE) == 0) {
183 __xfs_xattr_put_listent(
184 context, XATTR_SYSTEM_PREFIX,
185 XATTR_SYSTEM_PREFIX_LEN,
186 XATTR_POSIX_ACL_ACCESS,
187 strlen(XATTR_POSIX_ACL_ACCESS));
188 } else if (namelen == SGI_ACL_DEFAULT_SIZE &&
189 strncmp(name, SGI_ACL_DEFAULT,
190 SGI_ACL_DEFAULT_SIZE) == 0) {
191 __xfs_xattr_put_listent(
192 context, XATTR_SYSTEM_PREFIX,
193 XATTR_SYSTEM_PREFIX_LEN,
194 XATTR_POSIX_ACL_DEFAULT,
195 strlen(XATTR_POSIX_ACL_DEFAULT));
196 }
197#endif
198
199 /*
200 * Only show root namespace entries if we are actually allowed to
201 * see them.
202 */
203 if (!capable(CAP_SYS_ADMIN))
204 return;
205
206 prefix = XATTR_TRUSTED_PREFIX;
207 prefix_len = XATTR_TRUSTED_PREFIX_LEN;
208 } else if (flags & XFS_ATTR_SECURE) {
209 prefix = XATTR_SECURITY_PREFIX;
210 prefix_len = XATTR_SECURITY_PREFIX_LEN;
211 } else {
212 prefix = XATTR_USER_PREFIX;
213 prefix_len = XATTR_USER_PREFIX_LEN;
214 }
215
216 __xfs_xattr_put_listent(context, prefix, prefix_len, name,
217 namelen);
218 return;
219}
220
221ssize_t
222xfs_vn_listxattr(
223 struct dentry *dentry,
224 char *data,
225 size_t size)
226{
227 struct xfs_attr_list_context context;
228 struct attrlist_cursor_kern cursor = { 0 };
229 struct inode *inode = d_inode(dentry);
230 int error;
231
232 /*
233 * First read the regular on-disk attributes.
234 */
235 memset(&context, 0, sizeof(context));
236 context.dp = XFS_I(inode);
237 context.cursor = &cursor;
238 context.resynch = 1;
239 context.alist = size ? data : NULL;
240 context.bufsize = size;
241 context.firstu = context.bufsize;
242 context.put_listent = xfs_xattr_put_listent;
243
244 error = xfs_attr_list_int(&context);
245 if (error)
246 return error;
247 if (context.count < 0)
248 return -ERANGE;
249
250 return context.count;
251}
1// SPDX-License-Identifier: GPL-2.0
2/*
3 * Copyright (C) 2008 Christoph Hellwig.
4 * Portions Copyright (C) 2000-2008 Silicon Graphics, Inc.
5 */
6
7#include "xfs.h"
8#include "xfs_shared.h"
9#include "xfs_format.h"
10#include "xfs_log_format.h"
11#include "xfs_da_format.h"
12#include "xfs_trans_resv.h"
13#include "xfs_mount.h"
14#include "xfs_inode.h"
15#include "xfs_da_btree.h"
16#include "xfs_attr.h"
17#include "xfs_acl.h"
18#include "xfs_log.h"
19#include "xfs_xattr.h"
20
21#include <linux/posix_acl_xattr.h>
22
23/*
24 * Get permission to use log-assisted atomic exchange of file extents.
25 *
26 * Callers must not be running any transactions or hold any inode locks, and
27 * they must release the permission by calling xlog_drop_incompat_feat
28 * when they're done.
29 */
30static inline int
31xfs_attr_grab_log_assist(
32 struct xfs_mount *mp)
33{
34 int error = 0;
35
36 /*
37 * Protect ourselves from an idle log clearing the logged xattrs log
38 * incompat feature bit.
39 */
40 xlog_use_incompat_feat(mp->m_log);
41
42 /*
43 * If log-assisted xattrs are already enabled, the caller can use the
44 * log assisted swap functions with the log-incompat reference we got.
45 */
46 if (xfs_sb_version_haslogxattrs(&mp->m_sb))
47 return 0;
48
49 /* Enable log-assisted xattrs. */
50 error = xfs_add_incompat_log_feature(mp,
51 XFS_SB_FEAT_INCOMPAT_LOG_XATTRS);
52 if (error)
53 goto drop_incompat;
54
55 xfs_warn_mount(mp, XFS_OPSTATE_WARNED_LARP,
56 "EXPERIMENTAL logged extended attributes feature in use. Use at your own risk!");
57
58 return 0;
59drop_incompat:
60 xlog_drop_incompat_feat(mp->m_log);
61 return error;
62}
63
64static inline void
65xfs_attr_rele_log_assist(
66 struct xfs_mount *mp)
67{
68 xlog_drop_incompat_feat(mp->m_log);
69}
70
71static inline bool
72xfs_attr_want_log_assist(
73 struct xfs_mount *mp)
74{
75#ifdef DEBUG
76 /* Logged xattrs require a V5 super for log_incompat */
77 return xfs_has_crc(mp) && xfs_globals.larp;
78#else
79 return false;
80#endif
81}
82
83/*
84 * Set or remove an xattr, having grabbed the appropriate logging resources
85 * prior to calling libxfs.
86 */
87int
88xfs_attr_change(
89 struct xfs_da_args *args)
90{
91 struct xfs_mount *mp = args->dp->i_mount;
92 bool use_logging = false;
93 int error;
94
95 ASSERT(!(args->op_flags & XFS_DA_OP_LOGGED));
96
97 if (xfs_attr_want_log_assist(mp)) {
98 error = xfs_attr_grab_log_assist(mp);
99 if (error)
100 return error;
101
102 args->op_flags |= XFS_DA_OP_LOGGED;
103 use_logging = true;
104 }
105
106 error = xfs_attr_set(args);
107
108 if (use_logging)
109 xfs_attr_rele_log_assist(mp);
110 return error;
111}
112
113
114static int
115xfs_xattr_get(const struct xattr_handler *handler, struct dentry *unused,
116 struct inode *inode, const char *name, void *value, size_t size)
117{
118 struct xfs_da_args args = {
119 .dp = XFS_I(inode),
120 .attr_filter = handler->flags,
121 .name = name,
122 .namelen = strlen(name),
123 .value = value,
124 .valuelen = size,
125 };
126 int error;
127
128 error = xfs_attr_get(&args);
129 if (error)
130 return error;
131 return args.valuelen;
132}
133
134static int
135xfs_xattr_set(const struct xattr_handler *handler,
136 struct user_namespace *mnt_userns, struct dentry *unused,
137 struct inode *inode, const char *name, const void *value,
138 size_t size, int flags)
139{
140 struct xfs_da_args args = {
141 .dp = XFS_I(inode),
142 .attr_filter = handler->flags,
143 .attr_flags = flags,
144 .name = name,
145 .namelen = strlen(name),
146 .value = (void *)value,
147 .valuelen = size,
148 };
149 int error;
150
151 error = xfs_attr_change(&args);
152 if (!error && (handler->flags & XFS_ATTR_ROOT))
153 xfs_forget_acl(inode, name);
154 return error;
155}
156
157static const struct xattr_handler xfs_xattr_user_handler = {
158 .prefix = XATTR_USER_PREFIX,
159 .flags = 0, /* no flags implies user namespace */
160 .get = xfs_xattr_get,
161 .set = xfs_xattr_set,
162};
163
164static const struct xattr_handler xfs_xattr_trusted_handler = {
165 .prefix = XATTR_TRUSTED_PREFIX,
166 .flags = XFS_ATTR_ROOT,
167 .get = xfs_xattr_get,
168 .set = xfs_xattr_set,
169};
170
171static const struct xattr_handler xfs_xattr_security_handler = {
172 .prefix = XATTR_SECURITY_PREFIX,
173 .flags = XFS_ATTR_SECURE,
174 .get = xfs_xattr_get,
175 .set = xfs_xattr_set,
176};
177
178const struct xattr_handler *xfs_xattr_handlers[] = {
179 &xfs_xattr_user_handler,
180 &xfs_xattr_trusted_handler,
181 &xfs_xattr_security_handler,
182#ifdef CONFIG_XFS_POSIX_ACL
183 &posix_acl_access_xattr_handler,
184 &posix_acl_default_xattr_handler,
185#endif
186 NULL
187};
188
189static void
190__xfs_xattr_put_listent(
191 struct xfs_attr_list_context *context,
192 char *prefix,
193 int prefix_len,
194 unsigned char *name,
195 int namelen)
196{
197 char *offset;
198 int arraytop;
199
200 if (context->count < 0 || context->seen_enough)
201 return;
202
203 if (!context->buffer)
204 goto compute_size;
205
206 arraytop = context->count + prefix_len + namelen + 1;
207 if (arraytop > context->firstu) {
208 context->count = -1; /* insufficient space */
209 context->seen_enough = 1;
210 return;
211 }
212 offset = context->buffer + context->count;
213 memcpy(offset, prefix, prefix_len);
214 offset += prefix_len;
215 strncpy(offset, (char *)name, namelen); /* real name */
216 offset += namelen;
217 *offset = '\0';
218
219compute_size:
220 context->count += prefix_len + namelen + 1;
221 return;
222}
223
224static void
225xfs_xattr_put_listent(
226 struct xfs_attr_list_context *context,
227 int flags,
228 unsigned char *name,
229 int namelen,
230 int valuelen)
231{
232 char *prefix;
233 int prefix_len;
234
235 ASSERT(context->count >= 0);
236
237 if (flags & XFS_ATTR_ROOT) {
238#ifdef CONFIG_XFS_POSIX_ACL
239 if (namelen == SGI_ACL_FILE_SIZE &&
240 strncmp(name, SGI_ACL_FILE,
241 SGI_ACL_FILE_SIZE) == 0) {
242 __xfs_xattr_put_listent(
243 context, XATTR_SYSTEM_PREFIX,
244 XATTR_SYSTEM_PREFIX_LEN,
245 XATTR_POSIX_ACL_ACCESS,
246 strlen(XATTR_POSIX_ACL_ACCESS));
247 } else if (namelen == SGI_ACL_DEFAULT_SIZE &&
248 strncmp(name, SGI_ACL_DEFAULT,
249 SGI_ACL_DEFAULT_SIZE) == 0) {
250 __xfs_xattr_put_listent(
251 context, XATTR_SYSTEM_PREFIX,
252 XATTR_SYSTEM_PREFIX_LEN,
253 XATTR_POSIX_ACL_DEFAULT,
254 strlen(XATTR_POSIX_ACL_DEFAULT));
255 }
256#endif
257
258 /*
259 * Only show root namespace entries if we are actually allowed to
260 * see them.
261 */
262 if (!capable(CAP_SYS_ADMIN))
263 return;
264
265 prefix = XATTR_TRUSTED_PREFIX;
266 prefix_len = XATTR_TRUSTED_PREFIX_LEN;
267 } else if (flags & XFS_ATTR_SECURE) {
268 prefix = XATTR_SECURITY_PREFIX;
269 prefix_len = XATTR_SECURITY_PREFIX_LEN;
270 } else {
271 prefix = XATTR_USER_PREFIX;
272 prefix_len = XATTR_USER_PREFIX_LEN;
273 }
274
275 __xfs_xattr_put_listent(context, prefix, prefix_len, name,
276 namelen);
277 return;
278}
279
280ssize_t
281xfs_vn_listxattr(
282 struct dentry *dentry,
283 char *data,
284 size_t size)
285{
286 struct xfs_attr_list_context context;
287 struct inode *inode = d_inode(dentry);
288 int error;
289
290 /*
291 * First read the regular on-disk attributes.
292 */
293 memset(&context, 0, sizeof(context));
294 context.dp = XFS_I(inode);
295 context.resynch = 1;
296 context.buffer = size ? data : NULL;
297 context.bufsize = size;
298 context.firstu = context.bufsize;
299 context.put_listent = xfs_xattr_put_listent;
300
301 error = xfs_attr_list(&context);
302 if (error)
303 return error;
304 if (context.count < 0)
305 return -ERANGE;
306
307 return context.count;
308}