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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_da_btree.h" | |
21 | #include "xfs_bmap_btree.h" | |
22 | #include "xfs_inode.h" | |
23 | #include "xfs_attr.h" | |
24 | #include "xfs_attr_leaf.h" | |
25 | #include "xfs_acl.h" | |
26 | #include "xfs_vnodeops.h" | |
27 | ||
28 | #include <linux/posix_acl_xattr.h> | |
29 | #include <linux/xattr.h> | |
30 | ||
31 | ||
32 | /* | |
33 | * ACL handling. Should eventually be moved into xfs_acl.c | |
34 | */ | |
35 | ||
36 | static int | |
37 | xfs_decode_acl(const char *name) | |
38 | { | |
39 | if (strcmp(name, "posix_acl_access") == 0) | |
40 | return _ACL_TYPE_ACCESS; | |
41 | else if (strcmp(name, "posix_acl_default") == 0) | |
42 | return _ACL_TYPE_DEFAULT; | |
43 | return -EINVAL; | |
44 | } | |
45 | ||
46 | /* | |
47 | * Get system extended attributes which at the moment only | |
48 | * includes Posix ACLs. | |
49 | */ | |
50 | static int | |
51 | xfs_xattr_system_get(struct inode *inode, const char *name, | |
52 | void *buffer, size_t size) | |
53 | { | |
54 | int acl; | |
55 | ||
56 | acl = xfs_decode_acl(name); | |
57 | if (acl < 0) | |
58 | return acl; | |
59 | ||
60 | return xfs_acl_vget(inode, buffer, size, acl); | |
61 | } | |
62 | ||
63 | static int | |
64 | xfs_xattr_system_set(struct inode *inode, const char *name, | |
65 | const void *value, size_t size, int flags) | |
66 | { | |
f13fae2d | 67 | int acl; |
f9e09f09 LM |
68 | |
69 | acl = xfs_decode_acl(name); | |
70 | if (acl < 0) | |
71 | return acl; | |
72 | if (flags & XATTR_CREATE) | |
73 | return -EINVAL; | |
74 | ||
75 | if (!value) | |
76 | return xfs_acl_vremove(inode, acl); | |
77 | ||
f13fae2d | 78 | return xfs_acl_vset(inode, (void *)value, size, acl); |
f9e09f09 LM |
79 | } |
80 | ||
81 | static struct xattr_handler xfs_xattr_system_handler = { | |
82 | .prefix = XATTR_SYSTEM_PREFIX, | |
83 | .get = xfs_xattr_system_get, | |
84 | .set = xfs_xattr_system_set, | |
85 | }; | |
86 | ||
87 | ||
88 | /* | |
89 | * Real xattr handling. The only difference between the namespaces is | |
90 | * a flag passed to the low-level attr code. | |
91 | */ | |
92 | ||
93 | static int | |
94 | __xfs_xattr_get(struct inode *inode, const char *name, | |
95 | void *value, size_t size, int xflags) | |
96 | { | |
97 | struct xfs_inode *ip = XFS_I(inode); | |
98 | int error, asize = size; | |
99 | ||
100 | if (strcmp(name, "") == 0) | |
101 | return -EINVAL; | |
102 | ||
103 | /* Convert Linux syscall to XFS internal ATTR flags */ | |
104 | if (!size) { | |
105 | xflags |= ATTR_KERNOVAL; | |
106 | value = NULL; | |
107 | } | |
108 | ||
109 | error = -xfs_attr_get(ip, name, value, &asize, xflags); | |
110 | if (error) | |
111 | return error; | |
112 | return asize; | |
113 | } | |
114 | ||
115 | static int | |
116 | __xfs_xattr_set(struct inode *inode, const char *name, const void *value, | |
117 | size_t size, int flags, int xflags) | |
118 | { | |
119 | struct xfs_inode *ip = XFS_I(inode); | |
120 | ||
121 | if (strcmp(name, "") == 0) | |
122 | return -EINVAL; | |
123 | ||
124 | /* Convert Linux syscall to XFS internal ATTR flags */ | |
125 | if (flags & XATTR_CREATE) | |
126 | xflags |= ATTR_CREATE; | |
127 | if (flags & XATTR_REPLACE) | |
128 | xflags |= ATTR_REPLACE; | |
129 | ||
130 | if (!value) | |
131 | return -xfs_attr_remove(ip, name, xflags); | |
132 | return -xfs_attr_set(ip, name, (void *)value, size, xflags); | |
133 | } | |
134 | ||
135 | static int | |
136 | xfs_xattr_user_get(struct inode *inode, const char *name, | |
137 | void *value, size_t size) | |
138 | { | |
139 | return __xfs_xattr_get(inode, name, value, size, 0); | |
140 | } | |
141 | ||
142 | static int | |
143 | xfs_xattr_user_set(struct inode *inode, const char *name, | |
144 | const void *value, size_t size, int flags) | |
145 | { | |
146 | return __xfs_xattr_set(inode, name, value, size, flags, 0); | |
147 | } | |
148 | ||
149 | static struct xattr_handler xfs_xattr_user_handler = { | |
150 | .prefix = XATTR_USER_PREFIX, | |
151 | .get = xfs_xattr_user_get, | |
152 | .set = xfs_xattr_user_set, | |
153 | }; | |
154 | ||
155 | ||
156 | static int | |
157 | xfs_xattr_trusted_get(struct inode *inode, const char *name, | |
158 | void *value, size_t size) | |
159 | { | |
160 | return __xfs_xattr_get(inode, name, value, size, ATTR_ROOT); | |
161 | } | |
162 | ||
163 | static int | |
164 | xfs_xattr_trusted_set(struct inode *inode, const char *name, | |
165 | const void *value, size_t size, int flags) | |
166 | { | |
167 | return __xfs_xattr_set(inode, name, value, size, flags, ATTR_ROOT); | |
168 | } | |
169 | ||
170 | static struct xattr_handler xfs_xattr_trusted_handler = { | |
171 | .prefix = XATTR_TRUSTED_PREFIX, | |
172 | .get = xfs_xattr_trusted_get, | |
173 | .set = xfs_xattr_trusted_set, | |
174 | }; | |
175 | ||
176 | ||
177 | static int | |
178 | xfs_xattr_secure_get(struct inode *inode, const char *name, | |
179 | void *value, size_t size) | |
180 | { | |
181 | return __xfs_xattr_get(inode, name, value, size, ATTR_SECURE); | |
182 | } | |
183 | ||
184 | static int | |
185 | xfs_xattr_secure_set(struct inode *inode, const char *name, | |
186 | const void *value, size_t size, int flags) | |
187 | { | |
188 | return __xfs_xattr_set(inode, name, value, size, flags, ATTR_SECURE); | |
189 | } | |
190 | ||
191 | static struct xattr_handler xfs_xattr_security_handler = { | |
192 | .prefix = XATTR_SECURITY_PREFIX, | |
193 | .get = xfs_xattr_secure_get, | |
194 | .set = xfs_xattr_secure_set, | |
195 | }; | |
196 | ||
197 | ||
198 | struct xattr_handler *xfs_xattr_handlers[] = { | |
199 | &xfs_xattr_user_handler, | |
200 | &xfs_xattr_trusted_handler, | |
201 | &xfs_xattr_security_handler, | |
202 | &xfs_xattr_system_handler, | |
203 | NULL | |
204 | }; | |
205 | ||
206 | static unsigned int xfs_xattr_prefix_len(int flags) | |
207 | { | |
208 | if (flags & XFS_ATTR_SECURE) | |
209 | return sizeof("security"); | |
210 | else if (flags & XFS_ATTR_ROOT) | |
211 | return sizeof("trusted"); | |
212 | else | |
213 | return sizeof("user"); | |
214 | } | |
215 | ||
216 | static const char *xfs_xattr_prefix(int flags) | |
217 | { | |
218 | if (flags & XFS_ATTR_SECURE) | |
219 | return xfs_xattr_security_handler.prefix; | |
220 | else if (flags & XFS_ATTR_ROOT) | |
221 | return xfs_xattr_trusted_handler.prefix; | |
222 | else | |
223 | return xfs_xattr_user_handler.prefix; | |
224 | } | |
225 | ||
226 | static int | |
227 | xfs_xattr_put_listent(struct xfs_attr_list_context *context, int flags, | |
228 | char *name, int namelen, int valuelen, char *value) | |
229 | { | |
230 | unsigned int prefix_len = xfs_xattr_prefix_len(flags); | |
231 | char *offset; | |
232 | int arraytop; | |
233 | ||
234 | ASSERT(context->count >= 0); | |
235 | ||
236 | /* | |
237 | * Only show root namespace entries if we are actually allowed to | |
238 | * see them. | |
239 | */ | |
240 | if ((flags & XFS_ATTR_ROOT) && !capable(CAP_SYS_ADMIN)) | |
241 | return 0; | |
242 | ||
243 | arraytop = context->count + prefix_len + namelen + 1; | |
244 | if (arraytop > context->firstu) { | |
245 | context->count = -1; /* insufficient space */ | |
246 | return 1; | |
247 | } | |
248 | offset = (char *)context->alist + context->count; | |
249 | strncpy(offset, xfs_xattr_prefix(flags), prefix_len); | |
250 | offset += prefix_len; | |
251 | strncpy(offset, name, namelen); /* real name */ | |
252 | offset += namelen; | |
253 | *offset = '\0'; | |
254 | context->count += prefix_len + namelen + 1; | |
255 | return 0; | |
256 | } | |
257 | ||
258 | static int | |
259 | xfs_xattr_put_listent_sizes(struct xfs_attr_list_context *context, int flags, | |
260 | char *name, int namelen, int valuelen, char *value) | |
261 | { | |
262 | context->count += xfs_xattr_prefix_len(flags) + namelen + 1; | |
263 | return 0; | |
264 | } | |
265 | ||
266 | static int | |
267 | list_one_attr(const char *name, const size_t len, void *data, | |
268 | size_t size, ssize_t *result) | |
269 | { | |
270 | char *p = data + *result; | |
271 | ||
272 | *result += len; | |
273 | if (!size) | |
274 | return 0; | |
275 | if (*result > size) | |
276 | return -ERANGE; | |
277 | ||
278 | strcpy(p, name); | |
279 | return 0; | |
280 | } | |
281 | ||
282 | ssize_t | |
283 | xfs_vn_listxattr(struct dentry *dentry, char *data, size_t size) | |
284 | { | |
285 | struct xfs_attr_list_context context; | |
286 | struct attrlist_cursor_kern cursor = { 0 }; | |
287 | struct inode *inode = dentry->d_inode; | |
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.cursor = &cursor; | |
296 | context.resynch = 1; | |
297 | context.alist = data; | |
298 | context.bufsize = size; | |
299 | context.firstu = context.bufsize; | |
300 | ||
301 | if (size) | |
302 | context.put_listent = xfs_xattr_put_listent; | |
303 | else | |
304 | context.put_listent = xfs_xattr_put_listent_sizes; | |
305 | ||
306 | xfs_attr_list_int(&context); | |
307 | if (context.count < 0) | |
308 | return -ERANGE; | |
309 | ||
310 | /* | |
311 | * Then add the two synthetic ACL attributes. | |
312 | */ | |
313 | if (xfs_acl_vhasacl_access(inode)) { | |
314 | error = list_one_attr(POSIX_ACL_XATTR_ACCESS, | |
315 | strlen(POSIX_ACL_XATTR_ACCESS) + 1, | |
316 | data, size, &context.count); | |
317 | if (error) | |
318 | return error; | |
319 | } | |
320 | ||
321 | if (xfs_acl_vhasacl_default(inode)) { | |
322 | error = list_one_attr(POSIX_ACL_XATTR_DEFAULT, | |
323 | strlen(POSIX_ACL_XATTR_DEFAULT) + 1, | |
324 | data, size, &context.count); | |
325 | if (error) | |
326 | return error; | |
327 | } | |
328 | ||
329 | return context.count; | |
330 | } |