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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 /*
50 * Check if the filesystem featureset is new enough to set this log
51 * incompat feature bit. Strictly speaking, the minimum requirement is
52 * a V5 filesystem for the superblock field, but we'll require rmap
53 * or reflink to avoid having to deal with really old kernels.
54 */
55 if (!xfs_has_reflink(mp) && !xfs_has_rmapbt(mp)) {
56 error = -EOPNOTSUPP;
57 goto drop_incompat;
58 }
59
60 /* Enable log-assisted xattrs. */
61 error = xfs_add_incompat_log_feature(mp,
62 XFS_SB_FEAT_INCOMPAT_LOG_XATTRS);
63 if (error)
64 goto drop_incompat;
65
66 xfs_warn_mount(mp, XFS_OPSTATE_WARNED_LARP,
67 "EXPERIMENTAL logged extended attributes feature in use. Use at your own risk!");
68
69 return 0;
70drop_incompat:
71 xlog_drop_incompat_feat(mp->m_log);
72 return error;
73}
74
75static inline void
76xfs_attr_rele_log_assist(
77 struct xfs_mount *mp)
78{
79 xlog_drop_incompat_feat(mp->m_log);
80}
81
82static inline bool
83xfs_attr_want_log_assist(
84 struct xfs_mount *mp)
85{
86#ifdef DEBUG
87 /* Logged xattrs require a V5 super for log_incompat */
88 return xfs_has_crc(mp) && xfs_globals.larp;
89#else
90 return false;
91#endif
92}
93
94/*
95 * Set or remove an xattr, having grabbed the appropriate logging resources
96 * prior to calling libxfs.
97 */
98int
99xfs_attr_change(
100 struct xfs_da_args *args)
101{
102 struct xfs_mount *mp = args->dp->i_mount;
103 bool use_logging = false;
104 int error;
105
106 ASSERT(!(args->op_flags & XFS_DA_OP_LOGGED));
107
108 if (xfs_attr_want_log_assist(mp)) {
109 error = xfs_attr_grab_log_assist(mp);
110 if (error)
111 return error;
112
113 args->op_flags |= XFS_DA_OP_LOGGED;
114 use_logging = true;
115 }
116
117 error = xfs_attr_set(args);
118
119 if (use_logging)
120 xfs_attr_rele_log_assist(mp);
121 return error;
122}
123
124
125static int
126xfs_xattr_get(const struct xattr_handler *handler, struct dentry *unused,
127 struct inode *inode, const char *name, void *value, size_t size)
128{
129 struct xfs_da_args args = {
130 .dp = XFS_I(inode),
131 .attr_filter = handler->flags,
132 .name = name,
133 .namelen = strlen(name),
134 .value = value,
135 .valuelen = size,
136 };
137 int error;
138
139 if (xfs_ifork_zapped(XFS_I(inode), XFS_ATTR_FORK))
140 return -EIO;
141
142 error = xfs_attr_get(&args);
143 if (error)
144 return error;
145 return args.valuelen;
146}
147
148static int
149xfs_xattr_set(const struct xattr_handler *handler,
150 struct mnt_idmap *idmap, struct dentry *unused,
151 struct inode *inode, const char *name, const void *value,
152 size_t size, int flags)
153{
154 struct xfs_da_args args = {
155 .dp = XFS_I(inode),
156 .attr_filter = handler->flags,
157 .attr_flags = flags,
158 .name = name,
159 .namelen = strlen(name),
160 .value = (void *)value,
161 .valuelen = size,
162 };
163 int error;
164
165 error = xfs_attr_change(&args);
166 if (!error && (handler->flags & XFS_ATTR_ROOT))
167 xfs_forget_acl(inode, name);
168 return error;
169}
170
171static const struct xattr_handler xfs_xattr_user_handler = {
172 .prefix = XATTR_USER_PREFIX,
173 .flags = 0, /* no flags implies user namespace */
174 .get = xfs_xattr_get,
175 .set = xfs_xattr_set,
176};
177
178static const struct xattr_handler xfs_xattr_trusted_handler = {
179 .prefix = XATTR_TRUSTED_PREFIX,
180 .flags = XFS_ATTR_ROOT,
181 .get = xfs_xattr_get,
182 .set = xfs_xattr_set,
183};
184
185static const struct xattr_handler xfs_xattr_security_handler = {
186 .prefix = XATTR_SECURITY_PREFIX,
187 .flags = XFS_ATTR_SECURE,
188 .get = xfs_xattr_get,
189 .set = xfs_xattr_set,
190};
191
192const struct xattr_handler * const xfs_xattr_handlers[] = {
193 &xfs_xattr_user_handler,
194 &xfs_xattr_trusted_handler,
195 &xfs_xattr_security_handler,
196 NULL
197};
198
199static void
200__xfs_xattr_put_listent(
201 struct xfs_attr_list_context *context,
202 char *prefix,
203 int prefix_len,
204 unsigned char *name,
205 int namelen)
206{
207 char *offset;
208 int arraytop;
209
210 if (context->count < 0 || context->seen_enough)
211 return;
212
213 if (!context->buffer)
214 goto compute_size;
215
216 arraytop = context->count + prefix_len + namelen + 1;
217 if (arraytop > context->firstu) {
218 context->count = -1; /* insufficient space */
219 context->seen_enough = 1;
220 return;
221 }
222 offset = context->buffer + context->count;
223 memcpy(offset, prefix, prefix_len);
224 offset += prefix_len;
225 strncpy(offset, (char *)name, namelen); /* real name */
226 offset += namelen;
227 *offset = '\0';
228
229compute_size:
230 context->count += prefix_len + namelen + 1;
231 return;
232}
233
234static void
235xfs_xattr_put_listent(
236 struct xfs_attr_list_context *context,
237 int flags,
238 unsigned char *name,
239 int namelen,
240 int valuelen)
241{
242 char *prefix;
243 int prefix_len;
244
245 ASSERT(context->count >= 0);
246
247 if (flags & XFS_ATTR_ROOT) {
248#ifdef CONFIG_XFS_POSIX_ACL
249 if (namelen == SGI_ACL_FILE_SIZE &&
250 strncmp(name, SGI_ACL_FILE,
251 SGI_ACL_FILE_SIZE) == 0) {
252 __xfs_xattr_put_listent(
253 context, XATTR_SYSTEM_PREFIX,
254 XATTR_SYSTEM_PREFIX_LEN,
255 XATTR_POSIX_ACL_ACCESS,
256 strlen(XATTR_POSIX_ACL_ACCESS));
257 } else if (namelen == SGI_ACL_DEFAULT_SIZE &&
258 strncmp(name, SGI_ACL_DEFAULT,
259 SGI_ACL_DEFAULT_SIZE) == 0) {
260 __xfs_xattr_put_listent(
261 context, XATTR_SYSTEM_PREFIX,
262 XATTR_SYSTEM_PREFIX_LEN,
263 XATTR_POSIX_ACL_DEFAULT,
264 strlen(XATTR_POSIX_ACL_DEFAULT));
265 }
266#endif
267
268 /*
269 * Only show root namespace entries if we are actually allowed to
270 * see them.
271 */
272 if (!capable(CAP_SYS_ADMIN))
273 return;
274
275 prefix = XATTR_TRUSTED_PREFIX;
276 prefix_len = XATTR_TRUSTED_PREFIX_LEN;
277 } else if (flags & XFS_ATTR_SECURE) {
278 prefix = XATTR_SECURITY_PREFIX;
279 prefix_len = XATTR_SECURITY_PREFIX_LEN;
280 } else {
281 prefix = XATTR_USER_PREFIX;
282 prefix_len = XATTR_USER_PREFIX_LEN;
283 }
284
285 __xfs_xattr_put_listent(context, prefix, prefix_len, name,
286 namelen);
287 return;
288}
289
290ssize_t
291xfs_vn_listxattr(
292 struct dentry *dentry,
293 char *data,
294 size_t size)
295{
296 struct xfs_attr_list_context context;
297 struct inode *inode = d_inode(dentry);
298 int error;
299
300 if (xfs_ifork_zapped(XFS_I(inode), XFS_ATTR_FORK))
301 return -EIO;
302
303 /*
304 * First read the regular on-disk attributes.
305 */
306 memset(&context, 0, sizeof(context));
307 context.dp = XFS_I(inode);
308 context.resynch = 1;
309 context.buffer = size ? data : NULL;
310 context.bufsize = size;
311 context.firstu = context.bufsize;
312 context.put_listent = xfs_xattr_put_listent;
313
314 error = xfs_attr_list(&context);
315 if (error)
316 return error;
317 if (context.count < 0)
318 return -ERANGE;
319
320 return context.count;
321}
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_attr.h"
16#include "xfs_acl.h"
17#include "xfs_da_btree.h"
18
19#include <linux/posix_acl_xattr.h>
20
21
22static int
23xfs_xattr_get(const struct xattr_handler *handler, struct dentry *unused,
24 struct inode *inode, const char *name, void *value, size_t size)
25{
26 struct xfs_da_args args = {
27 .dp = XFS_I(inode),
28 .attr_filter = handler->flags,
29 .name = name,
30 .namelen = strlen(name),
31 .value = value,
32 .valuelen = size,
33 };
34 int error;
35
36 error = xfs_attr_get(&args);
37 if (error)
38 return error;
39 return args.valuelen;
40}
41
42static int
43xfs_xattr_set(const struct xattr_handler *handler,
44 struct user_namespace *mnt_userns, struct dentry *unused,
45 struct inode *inode, const char *name, const void *value,
46 size_t size, int flags)
47{
48 struct xfs_da_args args = {
49 .dp = XFS_I(inode),
50 .attr_filter = handler->flags,
51 .attr_flags = flags,
52 .name = name,
53 .namelen = strlen(name),
54 .value = (void *)value,
55 .valuelen = size,
56 };
57 int error;
58
59 error = xfs_attr_set(&args);
60 if (!error && (handler->flags & XFS_ATTR_ROOT))
61 xfs_forget_acl(inode, name);
62 return error;
63}
64
65static const struct xattr_handler xfs_xattr_user_handler = {
66 .prefix = XATTR_USER_PREFIX,
67 .flags = 0, /* no flags implies user namespace */
68 .get = xfs_xattr_get,
69 .set = xfs_xattr_set,
70};
71
72static const struct xattr_handler xfs_xattr_trusted_handler = {
73 .prefix = XATTR_TRUSTED_PREFIX,
74 .flags = XFS_ATTR_ROOT,
75 .get = xfs_xattr_get,
76 .set = xfs_xattr_set,
77};
78
79static const struct xattr_handler xfs_xattr_security_handler = {
80 .prefix = XATTR_SECURITY_PREFIX,
81 .flags = XFS_ATTR_SECURE,
82 .get = xfs_xattr_get,
83 .set = xfs_xattr_set,
84};
85
86const struct xattr_handler *xfs_xattr_handlers[] = {
87 &xfs_xattr_user_handler,
88 &xfs_xattr_trusted_handler,
89 &xfs_xattr_security_handler,
90#ifdef CONFIG_XFS_POSIX_ACL
91 &posix_acl_access_xattr_handler,
92 &posix_acl_default_xattr_handler,
93#endif
94 NULL
95};
96
97static void
98__xfs_xattr_put_listent(
99 struct xfs_attr_list_context *context,
100 char *prefix,
101 int prefix_len,
102 unsigned char *name,
103 int namelen)
104{
105 char *offset;
106 int arraytop;
107
108 if (context->count < 0 || context->seen_enough)
109 return;
110
111 if (!context->buffer)
112 goto compute_size;
113
114 arraytop = context->count + prefix_len + namelen + 1;
115 if (arraytop > context->firstu) {
116 context->count = -1; /* insufficient space */
117 context->seen_enough = 1;
118 return;
119 }
120 offset = context->buffer + context->count;
121 strncpy(offset, prefix, prefix_len);
122 offset += prefix_len;
123 strncpy(offset, (char *)name, namelen); /* real name */
124 offset += namelen;
125 *offset = '\0';
126
127compute_size:
128 context->count += prefix_len + namelen + 1;
129 return;
130}
131
132static void
133xfs_xattr_put_listent(
134 struct xfs_attr_list_context *context,
135 int flags,
136 unsigned char *name,
137 int namelen,
138 int valuelen)
139{
140 char *prefix;
141 int prefix_len;
142
143 ASSERT(context->count >= 0);
144
145 if (flags & XFS_ATTR_ROOT) {
146#ifdef CONFIG_XFS_POSIX_ACL
147 if (namelen == SGI_ACL_FILE_SIZE &&
148 strncmp(name, SGI_ACL_FILE,
149 SGI_ACL_FILE_SIZE) == 0) {
150 __xfs_xattr_put_listent(
151 context, XATTR_SYSTEM_PREFIX,
152 XATTR_SYSTEM_PREFIX_LEN,
153 XATTR_POSIX_ACL_ACCESS,
154 strlen(XATTR_POSIX_ACL_ACCESS));
155 } else if (namelen == SGI_ACL_DEFAULT_SIZE &&
156 strncmp(name, SGI_ACL_DEFAULT,
157 SGI_ACL_DEFAULT_SIZE) == 0) {
158 __xfs_xattr_put_listent(
159 context, XATTR_SYSTEM_PREFIX,
160 XATTR_SYSTEM_PREFIX_LEN,
161 XATTR_POSIX_ACL_DEFAULT,
162 strlen(XATTR_POSIX_ACL_DEFAULT));
163 }
164#endif
165
166 /*
167 * Only show root namespace entries if we are actually allowed to
168 * see them.
169 */
170 if (!capable(CAP_SYS_ADMIN))
171 return;
172
173 prefix = XATTR_TRUSTED_PREFIX;
174 prefix_len = XATTR_TRUSTED_PREFIX_LEN;
175 } else if (flags & XFS_ATTR_SECURE) {
176 prefix = XATTR_SECURITY_PREFIX;
177 prefix_len = XATTR_SECURITY_PREFIX_LEN;
178 } else {
179 prefix = XATTR_USER_PREFIX;
180 prefix_len = XATTR_USER_PREFIX_LEN;
181 }
182
183 __xfs_xattr_put_listent(context, prefix, prefix_len, name,
184 namelen);
185 return;
186}
187
188ssize_t
189xfs_vn_listxattr(
190 struct dentry *dentry,
191 char *data,
192 size_t size)
193{
194 struct xfs_attr_list_context context;
195 struct inode *inode = d_inode(dentry);
196 int error;
197
198 /*
199 * First read the regular on-disk attributes.
200 */
201 memset(&context, 0, sizeof(context));
202 context.dp = XFS_I(inode);
203 context.resynch = 1;
204 context.buffer = size ? data : NULL;
205 context.bufsize = size;
206 context.firstu = context.bufsize;
207 context.put_listent = xfs_xattr_put_listent;
208
209 error = xfs_attr_list(&context);
210 if (error)
211 return error;
212 if (context.count < 0)
213 return -ERANGE;
214
215 return context.count;
216}