Commit | Line | Data |
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1da177e4 LT |
1 | /* |
2 | * fs/nfs/idmap.c | |
3 | * | |
4 | * UID and GID to name mapping for clients. | |
5 | * | |
6 | * Copyright (c) 2002 The Regents of the University of Michigan. | |
7 | * All rights reserved. | |
8 | * | |
9 | * Marius Aamodt Eriksen <marius@umich.edu> | |
10 | * | |
11 | * Redistribution and use in source and binary forms, with or without | |
12 | * modification, are permitted provided that the following conditions | |
13 | * are met: | |
14 | * | |
15 | * 1. Redistributions of source code must retain the above copyright | |
16 | * notice, this list of conditions and the following disclaimer. | |
17 | * 2. Redistributions in binary form must reproduce the above copyright | |
18 | * notice, this list of conditions and the following disclaimer in the | |
19 | * documentation and/or other materials provided with the distribution. | |
20 | * 3. Neither the name of the University nor the names of its | |
21 | * contributors may be used to endorse or promote products derived | |
22 | * from this software without specific prior written permission. | |
23 | * | |
24 | * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESS OR IMPLIED | |
25 | * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF | |
26 | * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE | |
27 | * DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE | |
28 | * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR | |
29 | * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF | |
30 | * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR | |
31 | * BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF | |
32 | * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING | |
33 | * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS | |
34 | * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. | |
35 | */ | |
36 | ||
37 | #include <linux/module.h> | |
c9d5128a | 38 | #include <linux/mutex.h> |
1da177e4 LT |
39 | #include <linux/init.h> |
40 | #include <linux/types.h> | |
41 | #include <linux/slab.h> | |
42 | #include <linux/socket.h> | |
43 | #include <linux/in.h> | |
44 | #include <linux/sched.h> | |
45 | ||
46 | #include <linux/sunrpc/clnt.h> | |
47 | #include <linux/workqueue.h> | |
48 | #include <linux/sunrpc/rpc_pipe_fs.h> | |
49 | ||
1da177e4 LT |
50 | #include <linux/nfs_fs.h> |
51 | ||
52 | #include <linux/nfs_idmap.h> | |
4ce79717 | 53 | #include "nfs4_fs.h" |
1da177e4 LT |
54 | |
55 | #define IDMAP_HASH_SZ 128 | |
56 | ||
58df095b TM |
57 | /* Default cache timeout is 10 minutes */ |
58 | unsigned int nfs_idmap_cache_timeout = 600 * HZ; | |
59 | ||
7d4e2747 DH |
60 | static int param_set_idmap_timeout(const char *val, struct kernel_param *kp) |
61 | { | |
62 | char *endp; | |
63 | int num = simple_strtol(val, &endp, 0); | |
64 | int jif = num * HZ; | |
65 | if (endp == val || *endp || num < 0 || jif < num) | |
66 | return -EINVAL; | |
67 | *((int *)kp->arg) = jif; | |
68 | return 0; | |
69 | } | |
70 | ||
71 | module_param_call(idmap_cache_timeout, param_set_idmap_timeout, param_get_int, | |
72 | &nfs_idmap_cache_timeout, 0644); | |
73 | ||
1da177e4 | 74 | struct idmap_hashent { |
58df095b | 75 | unsigned long ih_expires; |
1da177e4 LT |
76 | __u32 ih_id; |
77 | int ih_namelen; | |
78 | char ih_name[IDMAP_NAMESZ]; | |
79 | }; | |
80 | ||
81 | struct idmap_hashtable { | |
82 | __u8 h_type; | |
83 | struct idmap_hashent h_entries[IDMAP_HASH_SZ]; | |
84 | }; | |
85 | ||
86 | struct idmap { | |
87 | char idmap_path[48]; | |
88 | struct dentry *idmap_dentry; | |
89 | wait_queue_head_t idmap_wq; | |
90 | struct idmap_msg idmap_im; | |
c9d5128a IM |
91 | struct mutex idmap_lock; /* Serializes upcalls */ |
92 | struct mutex idmap_im_lock; /* Protects the hashtable */ | |
1da177e4 LT |
93 | struct idmap_hashtable idmap_user_hash; |
94 | struct idmap_hashtable idmap_group_hash; | |
95 | }; | |
96 | ||
97 | static ssize_t idmap_pipe_upcall(struct file *, struct rpc_pipe_msg *, | |
98 | char __user *, size_t); | |
99 | static ssize_t idmap_pipe_downcall(struct file *, const char __user *, | |
100 | size_t); | |
75c96f85 | 101 | static void idmap_pipe_destroy_msg(struct rpc_pipe_msg *); |
1da177e4 LT |
102 | |
103 | static unsigned int fnvhash32(const void *, size_t); | |
104 | ||
105 | static struct rpc_pipe_ops idmap_upcall_ops = { | |
106 | .upcall = idmap_pipe_upcall, | |
107 | .downcall = idmap_pipe_downcall, | |
108 | .destroy_msg = idmap_pipe_destroy_msg, | |
109 | }; | |
110 | ||
111 | void | |
112 | nfs_idmap_new(struct nfs4_client *clp) | |
113 | { | |
114 | struct idmap *idmap; | |
115 | ||
116 | if (clp->cl_idmap != NULL) | |
117 | return; | |
bd647545 | 118 | if ((idmap = kzalloc(sizeof(*idmap), GFP_KERNEL)) == NULL) |
1da177e4 LT |
119 | return; |
120 | ||
1da177e4 LT |
121 | snprintf(idmap->idmap_path, sizeof(idmap->idmap_path), |
122 | "%s/idmap", clp->cl_rpcclient->cl_pathname); | |
123 | ||
124 | idmap->idmap_dentry = rpc_mkpipe(idmap->idmap_path, | |
125 | idmap, &idmap_upcall_ops, 0); | |
126 | if (IS_ERR(idmap->idmap_dentry)) { | |
127 | kfree(idmap); | |
128 | return; | |
129 | } | |
130 | ||
c9d5128a IM |
131 | mutex_init(&idmap->idmap_lock); |
132 | mutex_init(&idmap->idmap_im_lock); | |
1da177e4 LT |
133 | init_waitqueue_head(&idmap->idmap_wq); |
134 | idmap->idmap_user_hash.h_type = IDMAP_TYPE_USER; | |
135 | idmap->idmap_group_hash.h_type = IDMAP_TYPE_GROUP; | |
136 | ||
137 | clp->cl_idmap = idmap; | |
138 | } | |
139 | ||
140 | void | |
141 | nfs_idmap_delete(struct nfs4_client *clp) | |
142 | { | |
143 | struct idmap *idmap = clp->cl_idmap; | |
144 | ||
145 | if (!idmap) | |
146 | return; | |
5d67476f | 147 | rpc_unlink(idmap->idmap_dentry); |
1da177e4 LT |
148 | clp->cl_idmap = NULL; |
149 | kfree(idmap); | |
150 | } | |
151 | ||
152 | /* | |
153 | * Helper routines for manipulating the hashtable | |
154 | */ | |
155 | static inline struct idmap_hashent * | |
156 | idmap_name_hash(struct idmap_hashtable* h, const char *name, size_t len) | |
157 | { | |
158 | return &h->h_entries[fnvhash32(name, len) % IDMAP_HASH_SZ]; | |
159 | } | |
160 | ||
161 | static struct idmap_hashent * | |
162 | idmap_lookup_name(struct idmap_hashtable *h, const char *name, size_t len) | |
163 | { | |
164 | struct idmap_hashent *he = idmap_name_hash(h, name, len); | |
165 | ||
166 | if (he->ih_namelen != len || memcmp(he->ih_name, name, len) != 0) | |
167 | return NULL; | |
58df095b TM |
168 | if (time_after(jiffies, he->ih_expires)) |
169 | return NULL; | |
1da177e4 LT |
170 | return he; |
171 | } | |
172 | ||
173 | static inline struct idmap_hashent * | |
174 | idmap_id_hash(struct idmap_hashtable* h, __u32 id) | |
175 | { | |
176 | return &h->h_entries[fnvhash32(&id, sizeof(id)) % IDMAP_HASH_SZ]; | |
177 | } | |
178 | ||
179 | static struct idmap_hashent * | |
180 | idmap_lookup_id(struct idmap_hashtable *h, __u32 id) | |
181 | { | |
182 | struct idmap_hashent *he = idmap_id_hash(h, id); | |
183 | if (he->ih_id != id || he->ih_namelen == 0) | |
184 | return NULL; | |
58df095b TM |
185 | if (time_after(jiffies, he->ih_expires)) |
186 | return NULL; | |
1da177e4 LT |
187 | return he; |
188 | } | |
189 | ||
190 | /* | |
191 | * Routines for allocating new entries in the hashtable. | |
192 | * For now, we just have 1 entry per bucket, so it's all | |
193 | * pretty trivial. | |
194 | */ | |
195 | static inline struct idmap_hashent * | |
196 | idmap_alloc_name(struct idmap_hashtable *h, char *name, unsigned len) | |
197 | { | |
198 | return idmap_name_hash(h, name, len); | |
199 | } | |
200 | ||
201 | static inline struct idmap_hashent * | |
202 | idmap_alloc_id(struct idmap_hashtable *h, __u32 id) | |
203 | { | |
204 | return idmap_id_hash(h, id); | |
205 | } | |
206 | ||
207 | static void | |
208 | idmap_update_entry(struct idmap_hashent *he, const char *name, | |
209 | size_t namelen, __u32 id) | |
210 | { | |
211 | he->ih_id = id; | |
212 | memcpy(he->ih_name, name, namelen); | |
213 | he->ih_name[namelen] = '\0'; | |
214 | he->ih_namelen = namelen; | |
58df095b | 215 | he->ih_expires = jiffies + nfs_idmap_cache_timeout; |
1da177e4 LT |
216 | } |
217 | ||
218 | /* | |
219 | * Name -> ID | |
220 | */ | |
221 | static int | |
222 | nfs_idmap_id(struct idmap *idmap, struct idmap_hashtable *h, | |
223 | const char *name, size_t namelen, __u32 *id) | |
224 | { | |
225 | struct rpc_pipe_msg msg; | |
226 | struct idmap_msg *im; | |
227 | struct idmap_hashent *he; | |
228 | DECLARE_WAITQUEUE(wq, current); | |
229 | int ret = -EIO; | |
230 | ||
231 | im = &idmap->idmap_im; | |
232 | ||
233 | /* | |
234 | * String sanity checks | |
235 | * Note that the userland daemon expects NUL terminated strings | |
236 | */ | |
237 | for (;;) { | |
238 | if (namelen == 0) | |
239 | return -EINVAL; | |
240 | if (name[namelen-1] != '\0') | |
241 | break; | |
242 | namelen--; | |
243 | } | |
244 | if (namelen >= IDMAP_NAMESZ) | |
245 | return -EINVAL; | |
246 | ||
c9d5128a IM |
247 | mutex_lock(&idmap->idmap_lock); |
248 | mutex_lock(&idmap->idmap_im_lock); | |
1da177e4 LT |
249 | |
250 | he = idmap_lookup_name(h, name, namelen); | |
251 | if (he != NULL) { | |
252 | *id = he->ih_id; | |
253 | ret = 0; | |
254 | goto out; | |
255 | } | |
256 | ||
257 | memset(im, 0, sizeof(*im)); | |
258 | memcpy(im->im_name, name, namelen); | |
259 | ||
260 | im->im_type = h->h_type; | |
261 | im->im_conv = IDMAP_CONV_NAMETOID; | |
262 | ||
263 | memset(&msg, 0, sizeof(msg)); | |
264 | msg.data = im; | |
265 | msg.len = sizeof(*im); | |
266 | ||
267 | add_wait_queue(&idmap->idmap_wq, &wq); | |
268 | if (rpc_queue_upcall(idmap->idmap_dentry->d_inode, &msg) < 0) { | |
269 | remove_wait_queue(&idmap->idmap_wq, &wq); | |
270 | goto out; | |
271 | } | |
272 | ||
273 | set_current_state(TASK_UNINTERRUPTIBLE); | |
c9d5128a | 274 | mutex_unlock(&idmap->idmap_im_lock); |
1da177e4 LT |
275 | schedule(); |
276 | current->state = TASK_RUNNING; | |
277 | remove_wait_queue(&idmap->idmap_wq, &wq); | |
c9d5128a | 278 | mutex_lock(&idmap->idmap_im_lock); |
1da177e4 LT |
279 | |
280 | if (im->im_status & IDMAP_STATUS_SUCCESS) { | |
281 | *id = im->im_id; | |
282 | ret = 0; | |
283 | } | |
284 | ||
285 | out: | |
286 | memset(im, 0, sizeof(*im)); | |
c9d5128a IM |
287 | mutex_unlock(&idmap->idmap_im_lock); |
288 | mutex_unlock(&idmap->idmap_lock); | |
1da177e4 LT |
289 | return (ret); |
290 | } | |
291 | ||
292 | /* | |
293 | * ID -> Name | |
294 | */ | |
295 | static int | |
296 | nfs_idmap_name(struct idmap *idmap, struct idmap_hashtable *h, | |
297 | __u32 id, char *name) | |
298 | { | |
299 | struct rpc_pipe_msg msg; | |
300 | struct idmap_msg *im; | |
301 | struct idmap_hashent *he; | |
302 | DECLARE_WAITQUEUE(wq, current); | |
303 | int ret = -EIO; | |
304 | unsigned int len; | |
305 | ||
306 | im = &idmap->idmap_im; | |
307 | ||
c9d5128a IM |
308 | mutex_lock(&idmap->idmap_lock); |
309 | mutex_lock(&idmap->idmap_im_lock); | |
1da177e4 LT |
310 | |
311 | he = idmap_lookup_id(h, id); | |
312 | if (he != 0) { | |
313 | memcpy(name, he->ih_name, he->ih_namelen); | |
314 | ret = he->ih_namelen; | |
315 | goto out; | |
316 | } | |
317 | ||
318 | memset(im, 0, sizeof(*im)); | |
319 | im->im_type = h->h_type; | |
320 | im->im_conv = IDMAP_CONV_IDTONAME; | |
321 | im->im_id = id; | |
322 | ||
323 | memset(&msg, 0, sizeof(msg)); | |
324 | msg.data = im; | |
325 | msg.len = sizeof(*im); | |
326 | ||
327 | add_wait_queue(&idmap->idmap_wq, &wq); | |
328 | ||
329 | if (rpc_queue_upcall(idmap->idmap_dentry->d_inode, &msg) < 0) { | |
330 | remove_wait_queue(&idmap->idmap_wq, &wq); | |
331 | goto out; | |
332 | } | |
333 | ||
334 | set_current_state(TASK_UNINTERRUPTIBLE); | |
c9d5128a | 335 | mutex_unlock(&idmap->idmap_im_lock); |
1da177e4 LT |
336 | schedule(); |
337 | current->state = TASK_RUNNING; | |
338 | remove_wait_queue(&idmap->idmap_wq, &wq); | |
c9d5128a | 339 | mutex_lock(&idmap->idmap_im_lock); |
1da177e4 LT |
340 | |
341 | if (im->im_status & IDMAP_STATUS_SUCCESS) { | |
342 | if ((len = strnlen(im->im_name, IDMAP_NAMESZ)) == 0) | |
343 | goto out; | |
344 | memcpy(name, im->im_name, len); | |
345 | ret = len; | |
346 | } | |
347 | ||
348 | out: | |
349 | memset(im, 0, sizeof(*im)); | |
c9d5128a IM |
350 | mutex_unlock(&idmap->idmap_im_lock); |
351 | mutex_unlock(&idmap->idmap_lock); | |
1da177e4 LT |
352 | return ret; |
353 | } | |
354 | ||
355 | /* RPC pipefs upcall/downcall routines */ | |
356 | static ssize_t | |
357 | idmap_pipe_upcall(struct file *filp, struct rpc_pipe_msg *msg, | |
358 | char __user *dst, size_t buflen) | |
359 | { | |
360 | char *data = (char *)msg->data + msg->copied; | |
361 | ssize_t mlen = msg->len - msg->copied; | |
362 | ssize_t left; | |
363 | ||
364 | if (mlen > buflen) | |
365 | mlen = buflen; | |
366 | ||
367 | left = copy_to_user(dst, data, mlen); | |
368 | if (left < 0) { | |
369 | msg->errno = left; | |
370 | return left; | |
371 | } | |
372 | mlen -= left; | |
373 | msg->copied += mlen; | |
374 | msg->errno = 0; | |
375 | return mlen; | |
376 | } | |
377 | ||
378 | static ssize_t | |
379 | idmap_pipe_downcall(struct file *filp, const char __user *src, size_t mlen) | |
380 | { | |
381 | struct rpc_inode *rpci = RPC_I(filp->f_dentry->d_inode); | |
382 | struct idmap *idmap = (struct idmap *)rpci->private; | |
383 | struct idmap_msg im_in, *im = &idmap->idmap_im; | |
384 | struct idmap_hashtable *h; | |
385 | struct idmap_hashent *he = NULL; | |
386 | int namelen_in; | |
387 | int ret; | |
388 | ||
389 | if (mlen != sizeof(im_in)) | |
390 | return (-ENOSPC); | |
391 | ||
392 | if (copy_from_user(&im_in, src, mlen) != 0) | |
393 | return (-EFAULT); | |
394 | ||
c9d5128a | 395 | mutex_lock(&idmap->idmap_im_lock); |
1da177e4 LT |
396 | |
397 | ret = mlen; | |
398 | im->im_status = im_in.im_status; | |
399 | /* If we got an error, terminate now, and wake up pending upcalls */ | |
400 | if (!(im_in.im_status & IDMAP_STATUS_SUCCESS)) { | |
401 | wake_up(&idmap->idmap_wq); | |
402 | goto out; | |
403 | } | |
404 | ||
405 | /* Sanity checking of strings */ | |
406 | ret = -EINVAL; | |
407 | namelen_in = strnlen(im_in.im_name, IDMAP_NAMESZ); | |
408 | if (namelen_in == 0 || namelen_in == IDMAP_NAMESZ) | |
409 | goto out; | |
410 | ||
411 | switch (im_in.im_type) { | |
412 | case IDMAP_TYPE_USER: | |
413 | h = &idmap->idmap_user_hash; | |
414 | break; | |
415 | case IDMAP_TYPE_GROUP: | |
416 | h = &idmap->idmap_group_hash; | |
417 | break; | |
418 | default: | |
419 | goto out; | |
420 | } | |
421 | ||
422 | switch (im_in.im_conv) { | |
423 | case IDMAP_CONV_IDTONAME: | |
424 | /* Did we match the current upcall? */ | |
425 | if (im->im_conv == IDMAP_CONV_IDTONAME | |
426 | && im->im_type == im_in.im_type | |
427 | && im->im_id == im_in.im_id) { | |
428 | /* Yes: copy string, including the terminating '\0' */ | |
429 | memcpy(im->im_name, im_in.im_name, namelen_in); | |
430 | im->im_name[namelen_in] = '\0'; | |
431 | wake_up(&idmap->idmap_wq); | |
432 | } | |
433 | he = idmap_alloc_id(h, im_in.im_id); | |
434 | break; | |
435 | case IDMAP_CONV_NAMETOID: | |
436 | /* Did we match the current upcall? */ | |
437 | if (im->im_conv == IDMAP_CONV_NAMETOID | |
438 | && im->im_type == im_in.im_type | |
439 | && strnlen(im->im_name, IDMAP_NAMESZ) == namelen_in | |
440 | && memcmp(im->im_name, im_in.im_name, namelen_in) == 0) { | |
441 | im->im_id = im_in.im_id; | |
442 | wake_up(&idmap->idmap_wq); | |
443 | } | |
444 | he = idmap_alloc_name(h, im_in.im_name, namelen_in); | |
445 | break; | |
446 | default: | |
447 | goto out; | |
448 | } | |
449 | ||
450 | /* If the entry is valid, also copy it to the cache */ | |
451 | if (he != NULL) | |
452 | idmap_update_entry(he, im_in.im_name, namelen_in, im_in.im_id); | |
453 | ret = mlen; | |
454 | out: | |
c9d5128a | 455 | mutex_unlock(&idmap->idmap_im_lock); |
1da177e4 LT |
456 | return ret; |
457 | } | |
458 | ||
75c96f85 | 459 | static void |
1da177e4 LT |
460 | idmap_pipe_destroy_msg(struct rpc_pipe_msg *msg) |
461 | { | |
462 | struct idmap_msg *im = msg->data; | |
463 | struct idmap *idmap = container_of(im, struct idmap, idmap_im); | |
464 | ||
465 | if (msg->errno >= 0) | |
466 | return; | |
c9d5128a | 467 | mutex_lock(&idmap->idmap_im_lock); |
1da177e4 LT |
468 | im->im_status = IDMAP_STATUS_LOOKUPFAIL; |
469 | wake_up(&idmap->idmap_wq); | |
c9d5128a | 470 | mutex_unlock(&idmap->idmap_im_lock); |
1da177e4 LT |
471 | } |
472 | ||
473 | /* | |
474 | * Fowler/Noll/Vo hash | |
475 | * http://www.isthe.com/chongo/tech/comp/fnv/ | |
476 | */ | |
477 | ||
478 | #define FNV_P_32 ((unsigned int)0x01000193) /* 16777619 */ | |
479 | #define FNV_1_32 ((unsigned int)0x811c9dc5) /* 2166136261 */ | |
480 | ||
481 | static unsigned int fnvhash32(const void *buf, size_t buflen) | |
482 | { | |
483 | const unsigned char *p, *end = (const unsigned char *)buf + buflen; | |
484 | unsigned int hash = FNV_1_32; | |
485 | ||
486 | for (p = buf; p < end; p++) { | |
487 | hash *= FNV_P_32; | |
488 | hash ^= (unsigned int)*p; | |
489 | } | |
490 | ||
491 | return (hash); | |
492 | } | |
493 | ||
494 | int nfs_map_name_to_uid(struct nfs4_client *clp, const char *name, size_t namelen, __u32 *uid) | |
495 | { | |
496 | struct idmap *idmap = clp->cl_idmap; | |
497 | ||
498 | return nfs_idmap_id(idmap, &idmap->idmap_user_hash, name, namelen, uid); | |
499 | } | |
500 | ||
501 | int nfs_map_group_to_gid(struct nfs4_client *clp, const char *name, size_t namelen, __u32 *uid) | |
502 | { | |
503 | struct idmap *idmap = clp->cl_idmap; | |
504 | ||
505 | return nfs_idmap_id(idmap, &idmap->idmap_group_hash, name, namelen, uid); | |
506 | } | |
507 | ||
508 | int nfs_map_uid_to_name(struct nfs4_client *clp, __u32 uid, char *buf) | |
509 | { | |
510 | struct idmap *idmap = clp->cl_idmap; | |
511 | ||
512 | return nfs_idmap_name(idmap, &idmap->idmap_user_hash, uid, buf); | |
513 | } | |
514 | int nfs_map_gid_to_group(struct nfs4_client *clp, __u32 uid, char *buf) | |
515 | { | |
516 | struct idmap *idmap = clp->cl_idmap; | |
517 | ||
518 | return nfs_idmap_name(idmap, &idmap->idmap_group_hash, uid, buf); | |
519 | } | |
520 |