9pfs: xattr: fix memory leak in v9fs_list_xattr
[qemu.git] / hw / 9pfs / 9p-xattr.c
1 /*
2 * 9p xattr callback
3 *
4 * Copyright IBM, Corp. 2010
5 *
6 * Authors:
7 * Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
8 *
9 * This work is licensed under the terms of the GNU GPL, version 2. See
10 * the COPYING file in the top-level directory.
11 *
12 */
13
14 #include "qemu/osdep.h"
15 #include "9p.h"
16 #include "fsdev/file-op-9p.h"
17 #include "9p-xattr.h"
18 #include "9p-util.h"
19 #include "9p-local.h"
20
21
22 static XattrOperations *get_xattr_operations(XattrOperations **h,
23 const char *name)
24 {
25 XattrOperations *xops;
26 for (xops = *(h)++; xops != NULL; xops = *(h)++) {
27 if (!strncmp(name, xops->name, strlen(xops->name))) {
28 return xops;
29 }
30 }
31 return NULL;
32 }
33
34 ssize_t v9fs_get_xattr(FsContext *ctx, const char *path,
35 const char *name, void *value, size_t size)
36 {
37 XattrOperations *xops = get_xattr_operations(ctx->xops, name);
38 if (xops) {
39 return xops->getxattr(ctx, path, name, value, size);
40 }
41 errno = EOPNOTSUPP;
42 return -1;
43 }
44
45 ssize_t pt_listxattr(FsContext *ctx, const char *path,
46 char *name, void *value, size_t size)
47 {
48 int name_size = strlen(name) + 1;
49 if (!value) {
50 return name_size;
51 }
52
53 if (size < name_size) {
54 errno = ERANGE;
55 return -1;
56 }
57
58 /* no need for strncpy: name_size is strlen(name)+1 */
59 memcpy(value, name, name_size);
60 return name_size;
61 }
62
63 static ssize_t flistxattrat_nofollow(int dirfd, const char *filename,
64 char *list, size_t size)
65 {
66 char *proc_path = g_strdup_printf("/proc/self/fd/%d/%s", dirfd, filename);
67 int ret;
68
69 ret = llistxattr(proc_path, list, size);
70 g_free(proc_path);
71 return ret;
72 }
73
74 /*
75 * Get the list and pass to each layer to find out whether
76 * to send the data or not
77 */
78 ssize_t v9fs_list_xattr(FsContext *ctx, const char *path,
79 void *value, size_t vsize)
80 {
81 ssize_t size = 0;
82 void *ovalue = value;
83 XattrOperations *xops;
84 char *orig_value, *orig_value_start;
85 ssize_t xattr_len, parsed_len = 0, attr_len;
86 char *dirpath, *name;
87 int dirfd;
88
89 /* Get the actual len */
90 dirpath = g_path_get_dirname(path);
91 dirfd = local_opendir_nofollow(ctx, dirpath);
92 g_free(dirpath);
93 if (dirfd == -1) {
94 return -1;
95 }
96
97 name = g_path_get_basename(path);
98 xattr_len = flistxattrat_nofollow(dirfd, name, value, 0);
99 if (xattr_len <= 0) {
100 g_free(name);
101 close_preserve_errno(dirfd);
102 return xattr_len;
103 }
104
105 /* Now fetch the xattr and find the actual size */
106 orig_value = g_malloc(xattr_len);
107 xattr_len = flistxattrat_nofollow(dirfd, name, orig_value, xattr_len);
108 g_free(name);
109 close_preserve_errno(dirfd);
110 if (xattr_len < 0) {
111 g_free(orig_value);
112 return -1;
113 }
114
115 /* store the orig pointer */
116 orig_value_start = orig_value;
117 while (xattr_len > parsed_len) {
118 xops = get_xattr_operations(ctx->xops, orig_value);
119 if (!xops) {
120 goto next_entry;
121 }
122
123 if (!value) {
124 size += xops->listxattr(ctx, path, orig_value, value, vsize);
125 } else {
126 size = xops->listxattr(ctx, path, orig_value, value, vsize);
127 if (size < 0) {
128 goto err_out;
129 }
130 value += size;
131 vsize -= size;
132 }
133 next_entry:
134 /* Got the next entry */
135 attr_len = strlen(orig_value) + 1;
136 parsed_len += attr_len;
137 orig_value += attr_len;
138 }
139 if (value) {
140 size = value - ovalue;
141 }
142
143 err_out:
144 g_free(orig_value_start);
145 return size;
146 }
147
148 int v9fs_set_xattr(FsContext *ctx, const char *path, const char *name,
149 void *value, size_t size, int flags)
150 {
151 XattrOperations *xops = get_xattr_operations(ctx->xops, name);
152 if (xops) {
153 return xops->setxattr(ctx, path, name, value, size, flags);
154 }
155 errno = EOPNOTSUPP;
156 return -1;
157
158 }
159
160 int v9fs_remove_xattr(FsContext *ctx,
161 const char *path, const char *name)
162 {
163 XattrOperations *xops = get_xattr_operations(ctx->xops, name);
164 if (xops) {
165 return xops->removexattr(ctx, path, name);
166 }
167 errno = EOPNOTSUPP;
168 return -1;
169
170 }
171
172 ssize_t local_getxattr_nofollow(FsContext *ctx, const char *path,
173 const char *name, void *value, size_t size)
174 {
175 char *dirpath = g_path_get_dirname(path);
176 char *filename = g_path_get_basename(path);
177 int dirfd;
178 ssize_t ret = -1;
179
180 dirfd = local_opendir_nofollow(ctx, dirpath);
181 if (dirfd == -1) {
182 goto out;
183 }
184
185 ret = fgetxattrat_nofollow(dirfd, filename, name, value, size);
186 close_preserve_errno(dirfd);
187 out:
188 g_free(dirpath);
189 g_free(filename);
190 return ret;
191 }
192
193 ssize_t pt_getxattr(FsContext *ctx, const char *path, const char *name,
194 void *value, size_t size)
195 {
196 return local_getxattr_nofollow(ctx, path, name, value, size);
197 }
198
199 int fsetxattrat_nofollow(int dirfd, const char *filename, const char *name,
200 void *value, size_t size, int flags)
201 {
202 char *proc_path = g_strdup_printf("/proc/self/fd/%d/%s", dirfd, filename);
203 int ret;
204
205 ret = lsetxattr(proc_path, name, value, size, flags);
206 g_free(proc_path);
207 return ret;
208 }
209
210 ssize_t local_setxattr_nofollow(FsContext *ctx, const char *path,
211 const char *name, void *value, size_t size,
212 int flags)
213 {
214 char *dirpath = g_path_get_dirname(path);
215 char *filename = g_path_get_basename(path);
216 int dirfd;
217 ssize_t ret = -1;
218
219 dirfd = local_opendir_nofollow(ctx, dirpath);
220 if (dirfd == -1) {
221 goto out;
222 }
223
224 ret = fsetxattrat_nofollow(dirfd, filename, name, value, size, flags);
225 close_preserve_errno(dirfd);
226 out:
227 g_free(dirpath);
228 g_free(filename);
229 return ret;
230 }
231
232 int pt_setxattr(FsContext *ctx, const char *path, const char *name, void *value,
233 size_t size, int flags)
234 {
235 return local_setxattr_nofollow(ctx, path, name, value, size, flags);
236 }
237
238 static ssize_t fremovexattrat_nofollow(int dirfd, const char *filename,
239 const char *name)
240 {
241 char *proc_path = g_strdup_printf("/proc/self/fd/%d/%s", dirfd, filename);
242 int ret;
243
244 ret = lremovexattr(proc_path, name);
245 g_free(proc_path);
246 return ret;
247 }
248
249 ssize_t local_removexattr_nofollow(FsContext *ctx, const char *path,
250 const char *name)
251 {
252 char *dirpath = g_path_get_dirname(path);
253 char *filename = g_path_get_basename(path);
254 int dirfd;
255 ssize_t ret = -1;
256
257 dirfd = local_opendir_nofollow(ctx, dirpath);
258 if (dirfd == -1) {
259 goto out;
260 }
261
262 ret = fremovexattrat_nofollow(dirfd, filename, name);
263 close_preserve_errno(dirfd);
264 out:
265 g_free(dirpath);
266 g_free(filename);
267 return ret;
268 }
269
270 int pt_removexattr(FsContext *ctx, const char *path, const char *name)
271 {
272 return local_removexattr_nofollow(ctx, path, name);
273 }
274
275 ssize_t notsup_getxattr(FsContext *ctx, const char *path, const char *name,
276 void *value, size_t size)
277 {
278 errno = ENOTSUP;
279 return -1;
280 }
281
282 int notsup_setxattr(FsContext *ctx, const char *path, const char *name,
283 void *value, size_t size, int flags)
284 {
285 errno = ENOTSUP;
286 return -1;
287 }
288
289 ssize_t notsup_listxattr(FsContext *ctx, const char *path, char *name,
290 void *value, size_t size)
291 {
292 return 0;
293 }
294
295 int notsup_removexattr(FsContext *ctx, const char *path, const char *name)
296 {
297 errno = ENOTSUP;
298 return -1;
299 }
300
301 XattrOperations *mapped_xattr_ops[] = {
302 &mapped_user_xattr,
303 &mapped_pacl_xattr,
304 &mapped_dacl_xattr,
305 NULL,
306 };
307
308 XattrOperations *passthrough_xattr_ops[] = {
309 &passthrough_user_xattr,
310 &passthrough_acl_xattr,
311 NULL,
312 };
313
314 /* for .user none model should be same as passthrough */
315 XattrOperations *none_xattr_ops[] = {
316 &passthrough_user_xattr,
317 &none_acl_xattr,
318 NULL,
319 };