1 /*
2 * Copyright (c) 2004 The Regents of the University of Michigan.
3 * All rights reserved.
4 *
5 * Andy Adamson <andros@citi.umich.edu>
6 *
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
9 * are met:
10 *
11 * 1. Redistributions of source code must retain the above copyright
12 * notice, this list of conditions and the following disclaimer.
13 * 2. Redistributions in binary form must reproduce the above copyright
14 * notice, this list of conditions and the following disclaimer in the
15 * documentation and/or other materials provided with the distribution.
16 * 3. Neither the name of the University nor the names of its
17 * contributors may be used to endorse or promote products derived
18 * from this software without specific prior written permission.
19 *
20 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESS OR IMPLIED
21 * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
22 * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
23 * DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
24 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
25 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
26 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR
27 * BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
28 * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
29 * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
30 * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
31 *
32 */
33
34 #include <linux/file.h>
35 #include <linux/slab.h>
36 #include <linux/namei.h>
37 #include <linux/crypto.h>
38 #include <linux/sched.h>
39
40 #include "nfsd.h"
41 #include "state.h"
42 #include "vfs.h"
43
44 #define NFSDDBG_FACILITY NFSDDBG_PROC
45
46 /* Globals */
47 static struct file *rec_file;
48 static char user_recovery_dirname[PATH_MAX] = "/var/lib/nfs/v4recovery";
49
50 static int
nfs4_save_creds(const struct cred ** original_creds)51 nfs4_save_creds(const struct cred **original_creds)
52 {
53 struct cred *new;
54
55 new = prepare_creds();
56 if (!new)
57 return -ENOMEM;
58
59 new->fsuid = 0;
60 new->fsgid = 0;
61 *original_creds = override_creds(new);
62 put_cred(new);
63 return 0;
64 }
65
66 static void
nfs4_reset_creds(const struct cred * original)67 nfs4_reset_creds(const struct cred *original)
68 {
69 revert_creds(original);
70 }
71
72 static void
md5_to_hex(char * out,char * md5)73 md5_to_hex(char *out, char *md5)
74 {
75 int i;
76
77 for (i=0; i<16; i++) {
78 unsigned char c = md5[i];
79
80 *out++ = '0' + ((c&0xf0)>>4) + (c>=0xa0)*('a'-'9'-1);
81 *out++ = '0' + (c&0x0f) + ((c&0x0f)>=0x0a)*('a'-'9'-1);
82 }
83 *out = '\0';
84 }
85
86 __be32
nfs4_make_rec_clidname(char * dname,struct xdr_netobj * clname)87 nfs4_make_rec_clidname(char *dname, struct xdr_netobj *clname)
88 {
89 struct xdr_netobj cksum;
90 struct hash_desc desc;
91 struct scatterlist sg;
92 __be32 status = nfserr_jukebox;
93
94 dprintk("NFSD: nfs4_make_rec_clidname for %.*s\n",
95 clname->len, clname->data);
96 desc.flags = CRYPTO_TFM_REQ_MAY_SLEEP;
97 desc.tfm = crypto_alloc_hash("md5", 0, CRYPTO_ALG_ASYNC);
98 if (IS_ERR(desc.tfm))
99 goto out_no_tfm;
100 cksum.len = crypto_hash_digestsize(desc.tfm);
101 cksum.data = kmalloc(cksum.len, GFP_KERNEL);
102 if (cksum.data == NULL)
103 goto out;
104
105 sg_init_one(&sg, clname->data, clname->len);
106
107 if (crypto_hash_digest(&desc, &sg, sg.length, cksum.data))
108 goto out;
109
110 md5_to_hex(dname, cksum.data);
111
112 status = nfs_ok;
113 out:
114 kfree(cksum.data);
115 crypto_free_hash(desc.tfm);
116 out_no_tfm:
117 return status;
118 }
119
nfsd4_create_clid_dir(struct nfs4_client * clp)120 void nfsd4_create_clid_dir(struct nfs4_client *clp)
121 {
122 const struct cred *original_cred;
123 char *dname = clp->cl_recdir;
124 struct dentry *dir, *dentry;
125 int status;
126
127 dprintk("NFSD: nfsd4_create_clid_dir for \"%s\"\n", dname);
128
129 if (clp->cl_firststate)
130 return;
131 clp->cl_firststate = 1;
132 if (!rec_file)
133 return;
134 status = nfs4_save_creds(&original_cred);
135 if (status < 0)
136 return;
137
138 dir = rec_file->f_path.dentry;
139 /* lock the parent */
140 mutex_lock(&dir->d_inode->i_mutex);
141
142 dentry = lookup_one_len(dname, dir, HEXDIR_LEN-1);
143 if (IS_ERR(dentry)) {
144 status = PTR_ERR(dentry);
145 goto out_unlock;
146 }
147 if (dentry->d_inode)
148 /*
149 * In the 4.1 case, where we're called from
150 * reclaim_complete(), records from the previous reboot
151 * may still be left, so this is OK.
152 *
153 * In the 4.0 case, we should never get here; but we may
154 * as well be forgiving and just succeed silently.
155 */
156 goto out_put;
157 status = mnt_want_write_file(rec_file);
158 if (status)
159 goto out_put;
160 status = vfs_mkdir(dir->d_inode, dentry, S_IRWXU);
161 mnt_drop_write_file(rec_file);
162 out_put:
163 dput(dentry);
164 out_unlock:
165 mutex_unlock(&dir->d_inode->i_mutex);
166 if (status == 0)
167 vfs_fsync(rec_file, 0);
168 else
169 printk(KERN_ERR "NFSD: failed to write recovery record"
170 " (err %d); please check that %s exists"
171 " and is writeable", status,
172 user_recovery_dirname);
173 nfs4_reset_creds(original_cred);
174 }
175
176 typedef int (recdir_func)(struct dentry *, struct dentry *);
177
178 struct name_list {
179 char name[HEXDIR_LEN];
180 struct list_head list;
181 };
182
183 static int
nfsd4_build_namelist(void * arg,const char * name,int namlen,loff_t offset,u64 ino,unsigned int d_type)184 nfsd4_build_namelist(void *arg, const char *name, int namlen,
185 loff_t offset, u64 ino, unsigned int d_type)
186 {
187 struct list_head *names = arg;
188 struct name_list *entry;
189
190 if (namlen != HEXDIR_LEN - 1)
191 return 0;
192 entry = kmalloc(sizeof(struct name_list), GFP_KERNEL);
193 if (entry == NULL)
194 return -ENOMEM;
195 memcpy(entry->name, name, HEXDIR_LEN - 1);
196 entry->name[HEXDIR_LEN - 1] = '\0';
197 list_add(&entry->list, names);
198 return 0;
199 }
200
201 static int
nfsd4_list_rec_dir(recdir_func * f)202 nfsd4_list_rec_dir(recdir_func *f)
203 {
204 const struct cred *original_cred;
205 struct dentry *dir = rec_file->f_path.dentry;
206 LIST_HEAD(names);
207 int status;
208
209 status = nfs4_save_creds(&original_cred);
210 if (status < 0)
211 return status;
212
213 status = vfs_llseek(rec_file, 0, SEEK_SET);
214 if (status < 0) {
215 nfs4_reset_creds(original_cred);
216 return status;
217 }
218
219 status = vfs_readdir(rec_file, nfsd4_build_namelist, &names);
220 mutex_lock_nested(&dir->d_inode->i_mutex, I_MUTEX_PARENT);
221 while (!list_empty(&names)) {
222 struct name_list *entry;
223 entry = list_entry(names.next, struct name_list, list);
224 if (!status) {
225 struct dentry *dentry;
226 dentry = lookup_one_len(entry->name, dir, HEXDIR_LEN-1);
227 if (IS_ERR(dentry)) {
228 status = PTR_ERR(dentry);
229 break;
230 }
231 status = f(dir, dentry);
232 dput(dentry);
233 }
234 list_del(&entry->list);
235 kfree(entry);
236 }
237 mutex_unlock(&dir->d_inode->i_mutex);
238 nfs4_reset_creds(original_cred);
239 return status;
240 }
241
242 static int
nfsd4_unlink_clid_dir(char * name,int namlen)243 nfsd4_unlink_clid_dir(char *name, int namlen)
244 {
245 struct dentry *dir, *dentry;
246 int status;
247
248 dprintk("NFSD: nfsd4_unlink_clid_dir. name %.*s\n", namlen, name);
249
250 dir = rec_file->f_path.dentry;
251 mutex_lock_nested(&dir->d_inode->i_mutex, I_MUTEX_PARENT);
252 dentry = lookup_one_len(name, dir, namlen);
253 if (IS_ERR(dentry)) {
254 status = PTR_ERR(dentry);
255 goto out_unlock;
256 }
257 status = -ENOENT;
258 if (!dentry->d_inode)
259 goto out;
260 status = vfs_rmdir(dir->d_inode, dentry);
261 out:
262 dput(dentry);
263 out_unlock:
264 mutex_unlock(&dir->d_inode->i_mutex);
265 return status;
266 }
267
268 void
nfsd4_remove_clid_dir(struct nfs4_client * clp)269 nfsd4_remove_clid_dir(struct nfs4_client *clp)
270 {
271 const struct cred *original_cred;
272 int status;
273
274 if (!rec_file || !clp->cl_firststate)
275 return;
276
277 status = mnt_want_write_file(rec_file);
278 if (status)
279 goto out;
280 clp->cl_firststate = 0;
281
282 status = nfs4_save_creds(&original_cred);
283 if (status < 0)
284 goto out;
285
286 status = nfsd4_unlink_clid_dir(clp->cl_recdir, HEXDIR_LEN-1);
287 nfs4_reset_creds(original_cred);
288 if (status == 0)
289 vfs_fsync(rec_file, 0);
290 mnt_drop_write_file(rec_file);
291 out:
292 if (status)
293 printk("NFSD: Failed to remove expired client state directory"
294 " %.*s\n", HEXDIR_LEN, clp->cl_recdir);
295 return;
296 }
297
298 static int
purge_old(struct dentry * parent,struct dentry * child)299 purge_old(struct dentry *parent, struct dentry *child)
300 {
301 int status;
302
303 if (nfs4_has_reclaimed_state(child->d_name.name, false))
304 return 0;
305
306 status = vfs_rmdir(parent->d_inode, child);
307 if (status)
308 printk("failed to remove client recovery directory %s\n",
309 child->d_name.name);
310 /* Keep trying, success or failure: */
311 return 0;
312 }
313
314 void
nfsd4_recdir_purge_old(void)315 nfsd4_recdir_purge_old(void) {
316 int status;
317
318 if (!rec_file)
319 return;
320 status = mnt_want_write_file(rec_file);
321 if (status)
322 goto out;
323 status = nfsd4_list_rec_dir(purge_old);
324 if (status == 0)
325 vfs_fsync(rec_file, 0);
326 mnt_drop_write_file(rec_file);
327 out:
328 if (status)
329 printk("nfsd4: failed to purge old clients from recovery"
330 " directory %s\n", rec_file->f_path.dentry->d_name.name);
331 }
332
333 static int
load_recdir(struct dentry * parent,struct dentry * child)334 load_recdir(struct dentry *parent, struct dentry *child)
335 {
336 if (child->d_name.len != HEXDIR_LEN - 1) {
337 printk("nfsd4: illegal name %s in recovery directory\n",
338 child->d_name.name);
339 /* Keep trying; maybe the others are OK: */
340 return 0;
341 }
342 nfs4_client_to_reclaim(child->d_name.name);
343 return 0;
344 }
345
346 int
nfsd4_recdir_load(void)347 nfsd4_recdir_load(void) {
348 int status;
349
350 if (!rec_file)
351 return 0;
352
353 status = nfsd4_list_rec_dir(load_recdir);
354 if (status)
355 printk("nfsd4: failed loading clients from recovery"
356 " directory %s\n", rec_file->f_path.dentry->d_name.name);
357 return status;
358 }
359
360 /*
361 * Hold reference to the recovery directory.
362 */
363
364 void
nfsd4_init_recdir()365 nfsd4_init_recdir()
366 {
367 const struct cred *original_cred;
368 int status;
369
370 printk("NFSD: Using %s as the NFSv4 state recovery directory\n",
371 user_recovery_dirname);
372
373 BUG_ON(rec_file);
374
375 status = nfs4_save_creds(&original_cred);
376 if (status < 0) {
377 printk("NFSD: Unable to change credentials to find recovery"
378 " directory: error %d\n",
379 status);
380 return;
381 }
382
383 rec_file = filp_open(user_recovery_dirname, O_RDONLY | O_DIRECTORY, 0);
384 if (IS_ERR(rec_file)) {
385 printk("NFSD: unable to find recovery directory %s\n",
386 user_recovery_dirname);
387 rec_file = NULL;
388 }
389
390 nfs4_reset_creds(original_cred);
391 }
392
393 void
nfsd4_shutdown_recdir(void)394 nfsd4_shutdown_recdir(void)
395 {
396 if (!rec_file)
397 return;
398 fput(rec_file);
399 rec_file = NULL;
400 }
401
402 /*
403 * Change the NFSv4 recovery directory to recdir.
404 */
405 int
nfs4_reset_recoverydir(char * recdir)406 nfs4_reset_recoverydir(char *recdir)
407 {
408 int status;
409 struct path path;
410
411 status = kern_path(recdir, LOOKUP_FOLLOW, &path);
412 if (status)
413 return status;
414 status = -ENOTDIR;
415 if (S_ISDIR(path.dentry->d_inode->i_mode)) {
416 strcpy(user_recovery_dirname, recdir);
417 status = 0;
418 }
419 path_put(&path);
420 return status;
421 }
422
423 char *
nfs4_recoverydir(void)424 nfs4_recoverydir(void)
425 {
426 return user_recovery_dirname;
427 }
428