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36#include <linux/err.h>
37#include <linux/sunrpc/svc.h>
38#include <linux/nfsd/nfsd.h>
39#include <linux/nfs4.h>
40#include <linux/nfsd/state.h>
41#include <linux/nfsd/xdr4.h>
42#include <linux/param.h>
43#include <linux/file.h>
44#include <linux/namei.h>
45#include <asm/uaccess.h>
46#include <linux/scatterlist.h>
47#include <linux/crypto.h>
48#include <linux/sched.h>
49#include <linux/mount.h>
50
51#define NFSDDBG_FACILITY NFSDDBG_PROC
52
53
54static struct path rec_dir;
55static int rec_dir_init = 0;
56
57static int
58nfs4_save_creds(const struct cred **original_creds)
59{
60 struct cred *new;
61
62 new = prepare_creds();
63 if (!new)
64 return -ENOMEM;
65
66 new->fsuid = 0;
67 new->fsgid = 0;
68 *original_creds = override_creds(new);
69 put_cred(new);
70 return 0;
71}
72
73static void
74nfs4_reset_creds(const struct cred *original)
75{
76 revert_creds(original);
77}
78
79static void
80md5_to_hex(char *out, char *md5)
81{
82 int i;
83
84 for (i=0; i<16; i++) {
85 unsigned char c = md5[i];
86
87 *out++ = '0' + ((c&0xf0)>>4) + (c>=0xa0)*('a'-'9'-1);
88 *out++ = '0' + (c&0x0f) + ((c&0x0f)>=0x0a)*('a'-'9'-1);
89 }
90 *out = '\0';
91}
92
93__be32
94nfs4_make_rec_clidname(char *dname, struct xdr_netobj *clname)
95{
96 struct xdr_netobj cksum;
97 struct hash_desc desc;
98 struct scatterlist sg;
99 __be32 status = nfserr_resource;
100
101 dprintk("NFSD: nfs4_make_rec_clidname for %.*s\n",
102 clname->len, clname->data);
103 desc.flags = CRYPTO_TFM_REQ_MAY_SLEEP;
104 desc.tfm = crypto_alloc_hash("md5", 0, CRYPTO_ALG_ASYNC);
105 if (IS_ERR(desc.tfm))
106 goto out_no_tfm;
107 cksum.len = crypto_hash_digestsize(desc.tfm);
108 cksum.data = kmalloc(cksum.len, GFP_KERNEL);
109 if (cksum.data == NULL)
110 goto out;
111
112 sg_init_one(&sg, clname->data, clname->len);
113
114 if (crypto_hash_digest(&desc, &sg, sg.length, cksum.data))
115 goto out;
116
117 md5_to_hex(dname, cksum.data);
118
119 status = nfs_ok;
120out:
121 kfree(cksum.data);
122 crypto_free_hash(desc.tfm);
123out_no_tfm:
124 return status;
125}
126
127static void
128nfsd4_sync_rec_dir(void)
129{
130 mutex_lock(&rec_dir.dentry->d_inode->i_mutex);
131 nfsd_sync_dir(rec_dir.dentry);
132 mutex_unlock(&rec_dir.dentry->d_inode->i_mutex);
133}
134
135int
136nfsd4_create_clid_dir(struct nfs4_client *clp)
137{
138 const struct cred *original_cred;
139 char *dname = clp->cl_recdir;
140 struct dentry *dentry;
141 int status;
142
143 dprintk("NFSD: nfsd4_create_clid_dir for \"%s\"\n", dname);
144
145 if (!rec_dir_init || clp->cl_firststate)
146 return 0;
147
148 status = nfs4_save_creds(&original_cred);
149 if (status < 0)
150 return status;
151
152
153 mutex_lock(&rec_dir.dentry->d_inode->i_mutex);
154
155 dentry = lookup_one_len(dname, rec_dir.dentry, HEXDIR_LEN-1);
156 if (IS_ERR(dentry)) {
157 status = PTR_ERR(dentry);
158 goto out_unlock;
159 }
160 status = -EEXIST;
161 if (dentry->d_inode) {
162 dprintk("NFSD: nfsd4_create_clid_dir: DIRECTORY EXISTS\n");
163 goto out_put;
164 }
165 status = mnt_want_write(rec_dir.mnt);
166 if (status)
167 goto out_put;
168 status = vfs_mkdir(rec_dir.dentry->d_inode, dentry, S_IRWXU);
169 mnt_drop_write(rec_dir.mnt);
170out_put:
171 dput(dentry);
172out_unlock:
173 mutex_unlock(&rec_dir.dentry->d_inode->i_mutex);
174 if (status == 0) {
175 clp->cl_firststate = 1;
176 nfsd4_sync_rec_dir();
177 }
178 nfs4_reset_creds(original_cred);
179 dprintk("NFSD: nfsd4_create_clid_dir returns %d\n", status);
180 return status;
181}
182
183typedef int (recdir_func)(struct dentry *, struct dentry *);
184
185struct name_list {
186 char name[HEXDIR_LEN];
187 struct list_head list;
188};
189
190static int
191nfsd4_build_namelist(void *arg, const char *name, int namlen,
192 loff_t offset, u64 ino, unsigned int d_type)
193{
194 struct list_head *names = arg;
195 struct name_list *entry;
196
197 if (namlen != HEXDIR_LEN - 1)
198 return 0;
199 entry = kmalloc(sizeof(struct name_list), GFP_KERNEL);
200 if (entry == NULL)
201 return -ENOMEM;
202 memcpy(entry->name, name, HEXDIR_LEN - 1);
203 entry->name[HEXDIR_LEN - 1] = '\0';
204 list_add(&entry->list, names);
205 return 0;
206}
207
208static int
209nfsd4_list_rec_dir(struct dentry *dir, recdir_func *f)
210{
211 const struct cred *original_cred;
212 struct file *filp;
213 LIST_HEAD(names);
214 struct name_list *entry;
215 struct dentry *dentry;
216 int status;
217
218 if (!rec_dir_init)
219 return 0;
220
221 status = nfs4_save_creds(&original_cred);
222 if (status < 0)
223 return status;
224
225 filp = dentry_open(dget(dir), mntget(rec_dir.mnt), O_RDONLY,
226 current_cred());
227 status = PTR_ERR(filp);
228 if (IS_ERR(filp))
229 goto out;
230 status = vfs_readdir(filp, nfsd4_build_namelist, &names);
231 fput(filp);
232 mutex_lock_nested(&dir->d_inode->i_mutex, I_MUTEX_PARENT);
233 while (!list_empty(&names)) {
234 entry = list_entry(names.next, struct name_list, list);
235
236 dentry = lookup_one_len(entry->name, dir, HEXDIR_LEN-1);
237 if (IS_ERR(dentry)) {
238 status = PTR_ERR(dentry);
239 break;
240 }
241 status = f(dir, dentry);
242 dput(dentry);
243 if (status)
244 break;
245 list_del(&entry->list);
246 kfree(entry);
247 }
248 mutex_unlock(&dir->d_inode->i_mutex);
249out:
250 while (!list_empty(&names)) {
251 entry = list_entry(names.next, struct name_list, list);
252 list_del(&entry->list);
253 kfree(entry);
254 }
255 nfs4_reset_creds(original_cred);
256 return status;
257}
258
259static int
260nfsd4_unlink_clid_dir(char *name, int namlen)
261{
262 struct dentry *dentry;
263 int status;
264
265 dprintk("NFSD: nfsd4_unlink_clid_dir. name %.*s\n", namlen, name);
266
267 mutex_lock_nested(&rec_dir.dentry->d_inode->i_mutex, I_MUTEX_PARENT);
268 dentry = lookup_one_len(name, rec_dir.dentry, namlen);
269 if (IS_ERR(dentry)) {
270 status = PTR_ERR(dentry);
271 goto out_unlock;
272 }
273 status = -ENOENT;
274 if (!dentry->d_inode)
275 goto out;
276 status = vfs_rmdir(rec_dir.dentry->d_inode, dentry);
277out:
278 dput(dentry);
279out_unlock:
280 mutex_unlock(&rec_dir.dentry->d_inode->i_mutex);
281 return status;
282}
283
284void
285nfsd4_remove_clid_dir(struct nfs4_client *clp)
286{
287 const struct cred *original_cred;
288 int status;
289
290 if (!rec_dir_init || !clp->cl_firststate)
291 return;
292
293 status = mnt_want_write(rec_dir.mnt);
294 if (status)
295 goto out;
296 clp->cl_firststate = 0;
297
298 status = nfs4_save_creds(&original_cred);
299 if (status < 0)
300 goto out;
301
302 status = nfsd4_unlink_clid_dir(clp->cl_recdir, HEXDIR_LEN-1);
303 nfs4_reset_creds(original_cred);
304 if (status == 0)
305 nfsd4_sync_rec_dir();
306 mnt_drop_write(rec_dir.mnt);
307out:
308 if (status)
309 printk("NFSD: Failed to remove expired client state directory"
310 " %.*s\n", HEXDIR_LEN, clp->cl_recdir);
311 return;
312}
313
314static int
315purge_old(struct dentry *parent, struct dentry *child)
316{
317 int status;
318
319
320 if (nfs4_has_reclaimed_state(child->d_name.name, false))
321 return 0;
322
323 status = vfs_rmdir(parent->d_inode, child);
324 if (status)
325 printk("failed to remove client recovery directory %s\n",
326 child->d_name.name);
327
328 return 0;
329}
330
331void
332nfsd4_recdir_purge_old(void) {
333 int status;
334
335 if (!rec_dir_init)
336 return;
337 status = mnt_want_write(rec_dir.mnt);
338 if (status)
339 goto out;
340 status = nfsd4_list_rec_dir(rec_dir.dentry, purge_old);
341 if (status == 0)
342 nfsd4_sync_rec_dir();
343 mnt_drop_write(rec_dir.mnt);
344out:
345 if (status)
346 printk("nfsd4: failed to purge old clients from recovery"
347 " directory %s\n", rec_dir.dentry->d_name.name);
348}
349
350static int
351load_recdir(struct dentry *parent, struct dentry *child)
352{
353 if (child->d_name.len != HEXDIR_LEN - 1) {
354 printk("nfsd4: illegal name %s in recovery directory\n",
355 child->d_name.name);
356
357 return 0;
358 }
359 nfs4_client_to_reclaim(child->d_name.name);
360 return 0;
361}
362
363int
364nfsd4_recdir_load(void) {
365 int status;
366
367 status = nfsd4_list_rec_dir(rec_dir.dentry, load_recdir);
368 if (status)
369 printk("nfsd4: failed loading clients from recovery"
370 " directory %s\n", rec_dir.dentry->d_name.name);
371 return status;
372}
373
374
375
376
377
378void
379nfsd4_init_recdir(char *rec_dirname)
380{
381 const struct cred *original_cred;
382 int status;
383
384 printk("NFSD: Using %s as the NFSv4 state recovery directory\n",
385 rec_dirname);
386
387 BUG_ON(rec_dir_init);
388
389 status = nfs4_save_creds(&original_cred);
390 if (status < 0) {
391 printk("NFSD: Unable to change credentials to find recovery"
392 " directory: error %d\n",
393 status);
394 return;
395 }
396
397 status = kern_path(rec_dirname, LOOKUP_FOLLOW | LOOKUP_DIRECTORY,
398 &rec_dir);
399 if (status)
400 printk("NFSD: unable to find recovery directory %s\n",
401 rec_dirname);
402
403 if (!status)
404 rec_dir_init = 1;
405 nfs4_reset_creds(original_cred);
406}
407
408void
409nfsd4_shutdown_recdir(void)
410{
411 if (!rec_dir_init)
412 return;
413 rec_dir_init = 0;
414 path_put(&rec_dir);
415}
416
