blob: ffb8df91dc34198034264ae7d06de277094aef00 [file] [log] [blame]
Linus Torvalds1da177e2005-04-16 15:20:36 -07001/*
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>
38#include <linux/init.h>
39#include <linux/types.h>
40#include <linux/slab.h>
41#include <linux/socket.h>
42#include <linux/in.h>
43#include <linux/sched.h>
44
45#include <linux/sunrpc/clnt.h>
46#include <linux/workqueue.h>
47#include <linux/sunrpc/rpc_pipe_fs.h>
48
49#include <linux/nfs_fs_sb.h>
50#include <linux/nfs_fs.h>
51
52#include <linux/nfs_idmap.h>
Trond Myklebust4ce79712005-06-22 17:16:21 +000053#include "nfs4_fs.h"
Linus Torvalds1da177e2005-04-16 15:20:36 -070054
55#define IDMAP_HASH_SZ 128
56
57struct idmap_hashent {
58 __u32 ih_id;
59 int ih_namelen;
60 char ih_name[IDMAP_NAMESZ];
61};
62
63struct idmap_hashtable {
64 __u8 h_type;
65 struct idmap_hashent h_entries[IDMAP_HASH_SZ];
66};
67
68struct idmap {
69 char idmap_path[48];
70 struct dentry *idmap_dentry;
71 wait_queue_head_t idmap_wq;
72 struct idmap_msg idmap_im;
73 struct semaphore idmap_lock; /* Serializes upcalls */
74 struct semaphore idmap_im_lock; /* Protects the hashtable */
75 struct idmap_hashtable idmap_user_hash;
76 struct idmap_hashtable idmap_group_hash;
77};
78
79static ssize_t idmap_pipe_upcall(struct file *, struct rpc_pipe_msg *,
80 char __user *, size_t);
81static ssize_t idmap_pipe_downcall(struct file *, const char __user *,
82 size_t);
Adrian Bunk75c96f82005-05-05 16:16:09 -070083static void idmap_pipe_destroy_msg(struct rpc_pipe_msg *);
Linus Torvalds1da177e2005-04-16 15:20:36 -070084
85static unsigned int fnvhash32(const void *, size_t);
86
87static struct rpc_pipe_ops idmap_upcall_ops = {
88 .upcall = idmap_pipe_upcall,
89 .downcall = idmap_pipe_downcall,
90 .destroy_msg = idmap_pipe_destroy_msg,
91};
92
93void
94nfs_idmap_new(struct nfs4_client *clp)
95{
96 struct idmap *idmap;
97
98 if (clp->cl_idmap != NULL)
99 return;
100 if ((idmap = kmalloc(sizeof(*idmap), GFP_KERNEL)) == NULL)
101 return;
102
103 memset(idmap, 0, sizeof(*idmap));
104
105 snprintf(idmap->idmap_path, sizeof(idmap->idmap_path),
106 "%s/idmap", clp->cl_rpcclient->cl_pathname);
107
108 idmap->idmap_dentry = rpc_mkpipe(idmap->idmap_path,
109 idmap, &idmap_upcall_ops, 0);
110 if (IS_ERR(idmap->idmap_dentry)) {
111 kfree(idmap);
112 return;
113 }
114
115 init_MUTEX(&idmap->idmap_lock);
116 init_MUTEX(&idmap->idmap_im_lock);
117 init_waitqueue_head(&idmap->idmap_wq);
118 idmap->idmap_user_hash.h_type = IDMAP_TYPE_USER;
119 idmap->idmap_group_hash.h_type = IDMAP_TYPE_GROUP;
120
121 clp->cl_idmap = idmap;
122}
123
124void
125nfs_idmap_delete(struct nfs4_client *clp)
126{
127 struct idmap *idmap = clp->cl_idmap;
128
129 if (!idmap)
130 return;
131 rpc_unlink(idmap->idmap_path);
132 clp->cl_idmap = NULL;
133 kfree(idmap);
134}
135
136/*
137 * Helper routines for manipulating the hashtable
138 */
139static inline struct idmap_hashent *
140idmap_name_hash(struct idmap_hashtable* h, const char *name, size_t len)
141{
142 return &h->h_entries[fnvhash32(name, len) % IDMAP_HASH_SZ];
143}
144
145static struct idmap_hashent *
146idmap_lookup_name(struct idmap_hashtable *h, const char *name, size_t len)
147{
148 struct idmap_hashent *he = idmap_name_hash(h, name, len);
149
150 if (he->ih_namelen != len || memcmp(he->ih_name, name, len) != 0)
151 return NULL;
152 return he;
153}
154
155static inline struct idmap_hashent *
156idmap_id_hash(struct idmap_hashtable* h, __u32 id)
157{
158 return &h->h_entries[fnvhash32(&id, sizeof(id)) % IDMAP_HASH_SZ];
159}
160
161static struct idmap_hashent *
162idmap_lookup_id(struct idmap_hashtable *h, __u32 id)
163{
164 struct idmap_hashent *he = idmap_id_hash(h, id);
165 if (he->ih_id != id || he->ih_namelen == 0)
166 return NULL;
167 return he;
168}
169
170/*
171 * Routines for allocating new entries in the hashtable.
172 * For now, we just have 1 entry per bucket, so it's all
173 * pretty trivial.
174 */
175static inline struct idmap_hashent *
176idmap_alloc_name(struct idmap_hashtable *h, char *name, unsigned len)
177{
178 return idmap_name_hash(h, name, len);
179}
180
181static inline struct idmap_hashent *
182idmap_alloc_id(struct idmap_hashtable *h, __u32 id)
183{
184 return idmap_id_hash(h, id);
185}
186
187static void
188idmap_update_entry(struct idmap_hashent *he, const char *name,
189 size_t namelen, __u32 id)
190{
191 he->ih_id = id;
192 memcpy(he->ih_name, name, namelen);
193 he->ih_name[namelen] = '\0';
194 he->ih_namelen = namelen;
195}
196
197/*
198 * Name -> ID
199 */
200static int
201nfs_idmap_id(struct idmap *idmap, struct idmap_hashtable *h,
202 const char *name, size_t namelen, __u32 *id)
203{
204 struct rpc_pipe_msg msg;
205 struct idmap_msg *im;
206 struct idmap_hashent *he;
207 DECLARE_WAITQUEUE(wq, current);
208 int ret = -EIO;
209
210 im = &idmap->idmap_im;
211
212 /*
213 * String sanity checks
214 * Note that the userland daemon expects NUL terminated strings
215 */
216 for (;;) {
217 if (namelen == 0)
218 return -EINVAL;
219 if (name[namelen-1] != '\0')
220 break;
221 namelen--;
222 }
223 if (namelen >= IDMAP_NAMESZ)
224 return -EINVAL;
225
226 down(&idmap->idmap_lock);
227 down(&idmap->idmap_im_lock);
228
229 he = idmap_lookup_name(h, name, namelen);
230 if (he != NULL) {
231 *id = he->ih_id;
232 ret = 0;
233 goto out;
234 }
235
236 memset(im, 0, sizeof(*im));
237 memcpy(im->im_name, name, namelen);
238
239 im->im_type = h->h_type;
240 im->im_conv = IDMAP_CONV_NAMETOID;
241
242 memset(&msg, 0, sizeof(msg));
243 msg.data = im;
244 msg.len = sizeof(*im);
245
246 add_wait_queue(&idmap->idmap_wq, &wq);
247 if (rpc_queue_upcall(idmap->idmap_dentry->d_inode, &msg) < 0) {
248 remove_wait_queue(&idmap->idmap_wq, &wq);
249 goto out;
250 }
251
252 set_current_state(TASK_UNINTERRUPTIBLE);
253 up(&idmap->idmap_im_lock);
254 schedule();
255 current->state = TASK_RUNNING;
256 remove_wait_queue(&idmap->idmap_wq, &wq);
257 down(&idmap->idmap_im_lock);
258
259 if (im->im_status & IDMAP_STATUS_SUCCESS) {
260 *id = im->im_id;
261 ret = 0;
262 }
263
264 out:
265 memset(im, 0, sizeof(*im));
266 up(&idmap->idmap_im_lock);
267 up(&idmap->idmap_lock);
268 return (ret);
269}
270
271/*
272 * ID -> Name
273 */
274static int
275nfs_idmap_name(struct idmap *idmap, struct idmap_hashtable *h,
276 __u32 id, char *name)
277{
278 struct rpc_pipe_msg msg;
279 struct idmap_msg *im;
280 struct idmap_hashent *he;
281 DECLARE_WAITQUEUE(wq, current);
282 int ret = -EIO;
283 unsigned int len;
284
285 im = &idmap->idmap_im;
286
287 down(&idmap->idmap_lock);
288 down(&idmap->idmap_im_lock);
289
290 he = idmap_lookup_id(h, id);
291 if (he != 0) {
292 memcpy(name, he->ih_name, he->ih_namelen);
293 ret = he->ih_namelen;
294 goto out;
295 }
296
297 memset(im, 0, sizeof(*im));
298 im->im_type = h->h_type;
299 im->im_conv = IDMAP_CONV_IDTONAME;
300 im->im_id = id;
301
302 memset(&msg, 0, sizeof(msg));
303 msg.data = im;
304 msg.len = sizeof(*im);
305
306 add_wait_queue(&idmap->idmap_wq, &wq);
307
308 if (rpc_queue_upcall(idmap->idmap_dentry->d_inode, &msg) < 0) {
309 remove_wait_queue(&idmap->idmap_wq, &wq);
310 goto out;
311 }
312
313 set_current_state(TASK_UNINTERRUPTIBLE);
314 up(&idmap->idmap_im_lock);
315 schedule();
316 current->state = TASK_RUNNING;
317 remove_wait_queue(&idmap->idmap_wq, &wq);
318 down(&idmap->idmap_im_lock);
319
320 if (im->im_status & IDMAP_STATUS_SUCCESS) {
321 if ((len = strnlen(im->im_name, IDMAP_NAMESZ)) == 0)
322 goto out;
323 memcpy(name, im->im_name, len);
324 ret = len;
325 }
326
327 out:
328 memset(im, 0, sizeof(*im));
329 up(&idmap->idmap_im_lock);
330 up(&idmap->idmap_lock);
331 return ret;
332}
333
334/* RPC pipefs upcall/downcall routines */
335static ssize_t
336idmap_pipe_upcall(struct file *filp, struct rpc_pipe_msg *msg,
337 char __user *dst, size_t buflen)
338{
339 char *data = (char *)msg->data + msg->copied;
340 ssize_t mlen = msg->len - msg->copied;
341 ssize_t left;
342
343 if (mlen > buflen)
344 mlen = buflen;
345
346 left = copy_to_user(dst, data, mlen);
347 if (left < 0) {
348 msg->errno = left;
349 return left;
350 }
351 mlen -= left;
352 msg->copied += mlen;
353 msg->errno = 0;
354 return mlen;
355}
356
357static ssize_t
358idmap_pipe_downcall(struct file *filp, const char __user *src, size_t mlen)
359{
360 struct rpc_inode *rpci = RPC_I(filp->f_dentry->d_inode);
361 struct idmap *idmap = (struct idmap *)rpci->private;
362 struct idmap_msg im_in, *im = &idmap->idmap_im;
363 struct idmap_hashtable *h;
364 struct idmap_hashent *he = NULL;
365 int namelen_in;
366 int ret;
367
368 if (mlen != sizeof(im_in))
369 return (-ENOSPC);
370
371 if (copy_from_user(&im_in, src, mlen) != 0)
372 return (-EFAULT);
373
374 down(&idmap->idmap_im_lock);
375
376 ret = mlen;
377 im->im_status = im_in.im_status;
378 /* If we got an error, terminate now, and wake up pending upcalls */
379 if (!(im_in.im_status & IDMAP_STATUS_SUCCESS)) {
380 wake_up(&idmap->idmap_wq);
381 goto out;
382 }
383
384 /* Sanity checking of strings */
385 ret = -EINVAL;
386 namelen_in = strnlen(im_in.im_name, IDMAP_NAMESZ);
387 if (namelen_in == 0 || namelen_in == IDMAP_NAMESZ)
388 goto out;
389
390 switch (im_in.im_type) {
391 case IDMAP_TYPE_USER:
392 h = &idmap->idmap_user_hash;
393 break;
394 case IDMAP_TYPE_GROUP:
395 h = &idmap->idmap_group_hash;
396 break;
397 default:
398 goto out;
399 }
400
401 switch (im_in.im_conv) {
402 case IDMAP_CONV_IDTONAME:
403 /* Did we match the current upcall? */
404 if (im->im_conv == IDMAP_CONV_IDTONAME
405 && im->im_type == im_in.im_type
406 && im->im_id == im_in.im_id) {
407 /* Yes: copy string, including the terminating '\0' */
408 memcpy(im->im_name, im_in.im_name, namelen_in);
409 im->im_name[namelen_in] = '\0';
410 wake_up(&idmap->idmap_wq);
411 }
412 he = idmap_alloc_id(h, im_in.im_id);
413 break;
414 case IDMAP_CONV_NAMETOID:
415 /* Did we match the current upcall? */
416 if (im->im_conv == IDMAP_CONV_NAMETOID
417 && im->im_type == im_in.im_type
418 && strnlen(im->im_name, IDMAP_NAMESZ) == namelen_in
419 && memcmp(im->im_name, im_in.im_name, namelen_in) == 0) {
420 im->im_id = im_in.im_id;
421 wake_up(&idmap->idmap_wq);
422 }
423 he = idmap_alloc_name(h, im_in.im_name, namelen_in);
424 break;
425 default:
426 goto out;
427 }
428
429 /* If the entry is valid, also copy it to the cache */
430 if (he != NULL)
431 idmap_update_entry(he, im_in.im_name, namelen_in, im_in.im_id);
432 ret = mlen;
433out:
434 up(&idmap->idmap_im_lock);
435 return ret;
436}
437
Adrian Bunk75c96f82005-05-05 16:16:09 -0700438static void
Linus Torvalds1da177e2005-04-16 15:20:36 -0700439idmap_pipe_destroy_msg(struct rpc_pipe_msg *msg)
440{
441 struct idmap_msg *im = msg->data;
442 struct idmap *idmap = container_of(im, struct idmap, idmap_im);
443
444 if (msg->errno >= 0)
445 return;
446 down(&idmap->idmap_im_lock);
447 im->im_status = IDMAP_STATUS_LOOKUPFAIL;
448 wake_up(&idmap->idmap_wq);
449 up(&idmap->idmap_im_lock);
450}
451
452/*
453 * Fowler/Noll/Vo hash
454 * http://www.isthe.com/chongo/tech/comp/fnv/
455 */
456
457#define FNV_P_32 ((unsigned int)0x01000193) /* 16777619 */
458#define FNV_1_32 ((unsigned int)0x811c9dc5) /* 2166136261 */
459
460static unsigned int fnvhash32(const void *buf, size_t buflen)
461{
462 const unsigned char *p, *end = (const unsigned char *)buf + buflen;
463 unsigned int hash = FNV_1_32;
464
465 for (p = buf; p < end; p++) {
466 hash *= FNV_P_32;
467 hash ^= (unsigned int)*p;
468 }
469
470 return (hash);
471}
472
473int nfs_map_name_to_uid(struct nfs4_client *clp, const char *name, size_t namelen, __u32 *uid)
474{
475 struct idmap *idmap = clp->cl_idmap;
476
477 return nfs_idmap_id(idmap, &idmap->idmap_user_hash, name, namelen, uid);
478}
479
480int nfs_map_group_to_gid(struct nfs4_client *clp, const char *name, size_t namelen, __u32 *uid)
481{
482 struct idmap *idmap = clp->cl_idmap;
483
484 return nfs_idmap_id(idmap, &idmap->idmap_group_hash, name, namelen, uid);
485}
486
487int nfs_map_uid_to_name(struct nfs4_client *clp, __u32 uid, char *buf)
488{
489 struct idmap *idmap = clp->cl_idmap;
490
491 return nfs_idmap_name(idmap, &idmap->idmap_user_hash, uid, buf);
492}
493int nfs_map_gid_to_group(struct nfs4_client *clp, __u32 uid, char *buf)
494{
495 struct idmap *idmap = clp->cl_idmap;
496
497 return nfs_idmap_name(idmap, &idmap->idmap_group_hash, uid, buf);
498}
499