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f9e09f09 LM |
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 | { | |
67 | int error, acl; | |
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 | ||
78 | error = xfs_acl_vset(inode, (void *)value, size, acl); | |
79 | if (!error) | |
80 | vn_revalidate(inode); | |
81 | return error; | |
82 | } | |
83 | ||
84 | static struct xattr_handler xfs_xattr_system_handler = { | |
85 | .prefix = XATTR_SYSTEM_PREFIX, | |
86 | .get = xfs_xattr_system_get, | |
87 | .set = xfs_xattr_system_set, | |
88 | }; | |
89 | ||
90 | ||
91 | /* | |
92 | * Real xattr handling. The only difference between the namespaces is | |
93 | * a flag passed to the low-level attr code. | |
94 | */ | |
95 | ||
96 | static int | |
97 | __xfs_xattr_get(struct inode *inode, const char *name, | |
98 | void *value, size_t size, int xflags) | |
99 | { | |
100 | struct xfs_inode *ip = XFS_I(inode); | |
101 | int error, asize = size; | |
102 | ||
103 | if (strcmp(name, "") == 0) | |
104 | return -EINVAL; | |
105 | ||
106 | /* Convert Linux syscall to XFS internal ATTR flags */ | |
107 | if (!size) { | |
108 | xflags |= ATTR_KERNOVAL; | |
109 | value = NULL; | |
110 | } | |
111 | ||
112 | error = -xfs_attr_get(ip, name, value, &asize, xflags); | |
113 | if (error) | |
114 | return error; | |
115 | return asize; | |
116 | } | |
117 | ||
118 | static int | |
119 | __xfs_xattr_set(struct inode *inode, const char *name, const void *value, | |
120 | size_t size, int flags, int xflags) | |
121 | { | |
122 | struct xfs_inode *ip = XFS_I(inode); | |
123 | ||
124 | if (strcmp(name, "") == 0) | |
125 | return -EINVAL; | |
126 | ||
127 | /* Convert Linux syscall to XFS internal ATTR flags */ | |
128 | if (flags & XATTR_CREATE) | |
129 | xflags |= ATTR_CREATE; | |
130 | if (flags & XATTR_REPLACE) | |
131 | xflags |= ATTR_REPLACE; | |
132 | ||
133 | if (!value) | |
134 | return -xfs_attr_remove(ip, name, xflags); | |
135 | return -xfs_attr_set(ip, name, (void *)value, size, xflags); | |
136 | } | |
137 | ||
138 | static int | |
139 | xfs_xattr_user_get(struct inode *inode, const char *name, | |
140 | void *value, size_t size) | |
141 | { | |
142 | return __xfs_xattr_get(inode, name, value, size, 0); | |
143 | } | |
144 | ||
145 | static int | |
146 | xfs_xattr_user_set(struct inode *inode, const char *name, | |
147 | const void *value, size_t size, int flags) | |
148 | { | |
149 | return __xfs_xattr_set(inode, name, value, size, flags, 0); | |
150 | } | |
151 | ||
152 | static struct xattr_handler xfs_xattr_user_handler = { | |
153 | .prefix = XATTR_USER_PREFIX, | |
154 | .get = xfs_xattr_user_get, | |
155 | .set = xfs_xattr_user_set, | |
156 | }; | |
157 | ||
158 | ||
159 | static int | |
160 | xfs_xattr_trusted_get(struct inode *inode, const char *name, | |
161 | void *value, size_t size) | |
162 | { | |
163 | return __xfs_xattr_get(inode, name, value, size, ATTR_ROOT); | |
164 | } | |
165 | ||
166 | static int | |
167 | xfs_xattr_trusted_set(struct inode *inode, const char *name, | |
168 | const void *value, size_t size, int flags) | |
169 | { | |
170 | return __xfs_xattr_set(inode, name, value, size, flags, ATTR_ROOT); | |
171 | } | |
172 | ||
173 | static struct xattr_handler xfs_xattr_trusted_handler = { | |
174 | .prefix = XATTR_TRUSTED_PREFIX, | |
175 | .get = xfs_xattr_trusted_get, | |
176 | .set = xfs_xattr_trusted_set, | |
177 | }; | |
178 | ||
179 | ||
180 | static int | |
181 | xfs_xattr_secure_get(struct inode *inode, const char *name, | |
182 | void *value, size_t size) | |
183 | { | |
184 | return __xfs_xattr_get(inode, name, value, size, ATTR_SECURE); | |
185 | } | |
186 | ||
187 | static int | |
188 | xfs_xattr_secure_set(struct inode *inode, const char *name, | |
189 | const void *value, size_t size, int flags) | |
190 | { | |
191 | return __xfs_xattr_set(inode, name, value, size, flags, ATTR_SECURE); | |
192 | } | |
193 | ||
194 | static struct xattr_handler xfs_xattr_security_handler = { | |
195 | .prefix = XATTR_SECURITY_PREFIX, | |
196 | .get = xfs_xattr_secure_get, | |
197 | .set = xfs_xattr_secure_set, | |
198 | }; | |
199 | ||
200 | ||
201 | struct xattr_handler *xfs_xattr_handlers[] = { | |
202 | &xfs_xattr_user_handler, | |
203 | &xfs_xattr_trusted_handler, | |
204 | &xfs_xattr_security_handler, | |
205 | &xfs_xattr_system_handler, | |
206 | NULL | |
207 | }; | |
208 | ||
209 | static unsigned int xfs_xattr_prefix_len(int flags) | |
210 | { | |
211 | if (flags & XFS_ATTR_SECURE) | |
212 | return sizeof("security"); | |
213 | else if (flags & XFS_ATTR_ROOT) | |
214 | return sizeof("trusted"); | |
215 | else | |
216 | return sizeof("user"); | |
217 | } | |
218 | ||
219 | static const char *xfs_xattr_prefix(int flags) | |
220 | { | |
221 | if (flags & XFS_ATTR_SECURE) | |
222 | return xfs_xattr_security_handler.prefix; | |
223 | else if (flags & XFS_ATTR_ROOT) | |
224 | return xfs_xattr_trusted_handler.prefix; | |
225 | else | |
226 | return xfs_xattr_user_handler.prefix; | |
227 | } | |
228 | ||
229 | static int | |
230 | xfs_xattr_put_listent(struct xfs_attr_list_context *context, int flags, | |
231 | char *name, int namelen, int valuelen, char *value) | |
232 | { | |
233 | unsigned int prefix_len = xfs_xattr_prefix_len(flags); | |
234 | char *offset; | |
235 | int arraytop; | |
236 | ||
237 | ASSERT(context->count >= 0); | |
238 | ||
239 | /* | |
240 | * Only show root namespace entries if we are actually allowed to | |
241 | * see them. | |
242 | */ | |
243 | if ((flags & XFS_ATTR_ROOT) && !capable(CAP_SYS_ADMIN)) | |
244 | return 0; | |
245 | ||
246 | arraytop = context->count + prefix_len + namelen + 1; | |
247 | if (arraytop > context->firstu) { | |
248 | context->count = -1; /* insufficient space */ | |
249 | return 1; | |
250 | } | |
251 | offset = (char *)context->alist + context->count; | |
252 | strncpy(offset, xfs_xattr_prefix(flags), prefix_len); | |
253 | offset += prefix_len; | |
254 | strncpy(offset, name, namelen); /* real name */ | |
255 | offset += namelen; | |
256 | *offset = '\0'; | |
257 | context->count += prefix_len + namelen + 1; | |
258 | return 0; | |
259 | } | |
260 | ||
261 | static int | |
262 | xfs_xattr_put_listent_sizes(struct xfs_attr_list_context *context, int flags, | |
263 | char *name, int namelen, int valuelen, char *value) | |
264 | { | |
265 | context->count += xfs_xattr_prefix_len(flags) + namelen + 1; | |
266 | return 0; | |
267 | } | |
268 | ||
269 | static int | |
270 | list_one_attr(const char *name, const size_t len, void *data, | |
271 | size_t size, ssize_t *result) | |
272 | { | |
273 | char *p = data + *result; | |
274 | ||
275 | *result += len; | |
276 | if (!size) | |
277 | return 0; | |
278 | if (*result > size) | |
279 | return -ERANGE; | |
280 | ||
281 | strcpy(p, name); | |
282 | return 0; | |
283 | } | |
284 | ||
285 | ssize_t | |
286 | xfs_vn_listxattr(struct dentry *dentry, char *data, size_t size) | |
287 | { | |
288 | struct xfs_attr_list_context context; | |
289 | struct attrlist_cursor_kern cursor = { 0 }; | |
290 | struct inode *inode = dentry->d_inode; | |
291 | int error; | |
292 | ||
293 | /* | |
294 | * First read the regular on-disk attributes. | |
295 | */ | |
296 | memset(&context, 0, sizeof(context)); | |
297 | context.dp = XFS_I(inode); | |
298 | context.cursor = &cursor; | |
299 | context.resynch = 1; | |
300 | context.alist = data; | |
301 | context.bufsize = size; | |
302 | context.firstu = context.bufsize; | |
303 | ||
304 | if (size) | |
305 | context.put_listent = xfs_xattr_put_listent; | |
306 | else | |
307 | context.put_listent = xfs_xattr_put_listent_sizes; | |
308 | ||
309 | xfs_attr_list_int(&context); | |
310 | if (context.count < 0) | |
311 | return -ERANGE; | |
312 | ||
313 | /* | |
314 | * Then add the two synthetic ACL attributes. | |
315 | */ | |
316 | if (xfs_acl_vhasacl_access(inode)) { | |
317 | error = list_one_attr(POSIX_ACL_XATTR_ACCESS, | |
318 | strlen(POSIX_ACL_XATTR_ACCESS) + 1, | |
319 | data, size, &context.count); | |
320 | if (error) | |
321 | return error; | |
322 | } | |
323 | ||
324 | if (xfs_acl_vhasacl_default(inode)) { | |
325 | error = list_one_attr(POSIX_ACL_XATTR_DEFAULT, | |
326 | strlen(POSIX_ACL_XATTR_DEFAULT) + 1, | |
327 | data, size, &context.count); | |
328 | if (error) | |
329 | return error; | |
330 | } | |
331 | ||
332 | return context.count; | |
333 | } |