NFS: Move the nfs_set_port() call out of nfs_parse_mount_options()
[linux-2.6.git] / fs / nfs / idmap.c
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>
38 #include <linux/mutex.h>
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
50 #include <linux/nfs_fs.h>
51
52 #include <linux/nfs_idmap.h>
53 #include "nfs4_fs.h"
54
55 #define IDMAP_HASH_SZ          128
56
57 /* Default cache timeout is 10 minutes */
58 unsigned int nfs_idmap_cache_timeout = 600 * HZ;
59
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
74 struct idmap_hashent {
75         unsigned long           ih_expires;
76         __u32                   ih_id;
77         size_t                  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         struct dentry           *idmap_dentry;
88         wait_queue_head_t       idmap_wq;
89         struct idmap_msg        idmap_im;
90         struct mutex            idmap_lock;     /* Serializes upcalls */
91         struct mutex            idmap_im_lock;  /* Protects the hashtable */
92         struct idmap_hashtable  idmap_user_hash;
93         struct idmap_hashtable  idmap_group_hash;
94 };
95
96 static ssize_t idmap_pipe_upcall(struct file *, struct rpc_pipe_msg *,
97                                  char __user *, size_t);
98 static ssize_t idmap_pipe_downcall(struct file *, const char __user *,
99                                    size_t);
100 static void idmap_pipe_destroy_msg(struct rpc_pipe_msg *);
101
102 static unsigned int fnvhash32(const void *, size_t);
103
104 static struct rpc_pipe_ops idmap_upcall_ops = {
105         .upcall         = idmap_pipe_upcall,
106         .downcall       = idmap_pipe_downcall,
107         .destroy_msg    = idmap_pipe_destroy_msg,
108 };
109
110 int
111 nfs_idmap_new(struct nfs_client *clp)
112 {
113         struct idmap *idmap;
114         int error;
115
116         BUG_ON(clp->cl_idmap != NULL);
117
118         idmap = kzalloc(sizeof(*idmap), GFP_KERNEL);
119         if (idmap == NULL)
120                 return -ENOMEM;
121
122         idmap->idmap_dentry = rpc_mkpipe(clp->cl_rpcclient->cl_dentry, "idmap",
123                                          idmap, &idmap_upcall_ops, 0);
124         if (IS_ERR(idmap->idmap_dentry)) {
125                 error = PTR_ERR(idmap->idmap_dentry);
126                 kfree(idmap);
127                 return error;
128         }
129
130         mutex_init(&idmap->idmap_lock);
131         mutex_init(&idmap->idmap_im_lock);
132         init_waitqueue_head(&idmap->idmap_wq);
133         idmap->idmap_user_hash.h_type = IDMAP_TYPE_USER;
134         idmap->idmap_group_hash.h_type = IDMAP_TYPE_GROUP;
135
136         clp->cl_idmap = idmap;
137         return 0;
138 }
139
140 void
141 nfs_idmap_delete(struct nfs_client *clp)
142 {
143         struct idmap *idmap = clp->cl_idmap;
144
145         if (!idmap)
146                 return;
147         rpc_unlink(idmap->idmap_dentry);
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;
168         if (time_after(jiffies, he->ih_expires))
169                 return NULL;
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;
185         if (time_after(jiffies, he->ih_expires))
186                 return NULL;
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, size_t 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;
215         he->ih_expires = jiffies + nfs_idmap_cache_timeout;
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
247         mutex_lock(&idmap->idmap_lock);
248         mutex_lock(&idmap->idmap_im_lock);
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);
274         mutex_unlock(&idmap->idmap_im_lock);
275         schedule();
276         __set_current_state(TASK_RUNNING);
277         remove_wait_queue(&idmap->idmap_wq, &wq);
278         mutex_lock(&idmap->idmap_im_lock);
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));
287         mutex_unlock(&idmap->idmap_im_lock);
288         mutex_unlock(&idmap->idmap_lock);
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
308         mutex_lock(&idmap->idmap_lock);
309         mutex_lock(&idmap->idmap_im_lock);
310
311         he = idmap_lookup_id(h, id);
312         if (he) {
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);
335         mutex_unlock(&idmap->idmap_im_lock);
336         schedule();
337         __set_current_state(TASK_RUNNING);
338         remove_wait_queue(&idmap->idmap_wq, &wq);
339         mutex_lock(&idmap->idmap_im_lock);
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));
350         mutex_unlock(&idmap->idmap_im_lock);
351         mutex_unlock(&idmap->idmap_lock);
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         size_t mlen = min(msg->len, buflen);
362         unsigned long left;
363
364         left = copy_to_user(dst, data, mlen);
365         if (left == mlen) {
366                 msg->errno = -EFAULT;
367                 return -EFAULT;
368         }
369
370         mlen -= left;
371         msg->copied += mlen;
372         msg->errno = 0;
373         return mlen;
374 }
375
376 static ssize_t
377 idmap_pipe_downcall(struct file *filp, const char __user *src, size_t mlen)
378 {
379         struct rpc_inode *rpci = RPC_I(filp->f_path.dentry->d_inode);
380         struct idmap *idmap = (struct idmap *)rpci->private;
381         struct idmap_msg im_in, *im = &idmap->idmap_im;
382         struct idmap_hashtable *h;
383         struct idmap_hashent *he = NULL;
384         size_t namelen_in;
385         int ret;
386
387         if (mlen != sizeof(im_in))
388                 return -ENOSPC;
389
390         if (copy_from_user(&im_in, src, mlen) != 0)
391                 return -EFAULT;
392
393         mutex_lock(&idmap->idmap_im_lock);
394
395         ret = mlen;
396         im->im_status = im_in.im_status;
397         /* If we got an error, terminate now, and wake up pending upcalls */
398         if (!(im_in.im_status & IDMAP_STATUS_SUCCESS)) {
399                 wake_up(&idmap->idmap_wq);
400                 goto out;
401         }
402
403         /* Sanity checking of strings */
404         ret = -EINVAL;
405         namelen_in = strnlen(im_in.im_name, IDMAP_NAMESZ);
406         if (namelen_in == 0 || namelen_in == IDMAP_NAMESZ)
407                 goto out;
408
409         switch (im_in.im_type) {
410                 case IDMAP_TYPE_USER:
411                         h = &idmap->idmap_user_hash;
412                         break;
413                 case IDMAP_TYPE_GROUP:
414                         h = &idmap->idmap_group_hash;
415                         break;
416                 default:
417                         goto out;
418         }
419
420         switch (im_in.im_conv) {
421         case IDMAP_CONV_IDTONAME:
422                 /* Did we match the current upcall? */
423                 if (im->im_conv == IDMAP_CONV_IDTONAME
424                                 && im->im_type == im_in.im_type
425                                 && im->im_id == im_in.im_id) {
426                         /* Yes: copy string, including the terminating '\0'  */
427                         memcpy(im->im_name, im_in.im_name, namelen_in);
428                         im->im_name[namelen_in] = '\0';
429                         wake_up(&idmap->idmap_wq);
430                 }
431                 he = idmap_alloc_id(h, im_in.im_id);
432                 break;
433         case IDMAP_CONV_NAMETOID:
434                 /* Did we match the current upcall? */
435                 if (im->im_conv == IDMAP_CONV_NAMETOID
436                                 && im->im_type == im_in.im_type
437                                 && strnlen(im->im_name, IDMAP_NAMESZ) == namelen_in
438                                 && memcmp(im->im_name, im_in.im_name, namelen_in) == 0) {
439                         im->im_id = im_in.im_id;
440                         wake_up(&idmap->idmap_wq);
441                 }
442                 he = idmap_alloc_name(h, im_in.im_name, namelen_in);
443                 break;
444         default:
445                 goto out;
446         }
447
448         /* If the entry is valid, also copy it to the cache */
449         if (he != NULL)
450                 idmap_update_entry(he, im_in.im_name, namelen_in, im_in.im_id);
451         ret = mlen;
452 out:
453         mutex_unlock(&idmap->idmap_im_lock);
454         return ret;
455 }
456
457 static void
458 idmap_pipe_destroy_msg(struct rpc_pipe_msg *msg)
459 {
460         struct idmap_msg *im = msg->data;
461         struct idmap *idmap = container_of(im, struct idmap, idmap_im); 
462
463         if (msg->errno >= 0)
464                 return;
465         mutex_lock(&idmap->idmap_im_lock);
466         im->im_status = IDMAP_STATUS_LOOKUPFAIL;
467         wake_up(&idmap->idmap_wq);
468         mutex_unlock(&idmap->idmap_im_lock);
469 }
470
471 /* 
472  * Fowler/Noll/Vo hash
473  *    http://www.isthe.com/chongo/tech/comp/fnv/
474  */
475
476 #define FNV_P_32 ((unsigned int)0x01000193) /* 16777619 */
477 #define FNV_1_32 ((unsigned int)0x811c9dc5) /* 2166136261 */
478
479 static unsigned int fnvhash32(const void *buf, size_t buflen)
480 {
481         const unsigned char *p, *end = (const unsigned char *)buf + buflen;
482         unsigned int hash = FNV_1_32;
483
484         for (p = buf; p < end; p++) {
485                 hash *= FNV_P_32;
486                 hash ^= (unsigned int)*p;
487         }
488
489         return hash;
490 }
491
492 int nfs_map_name_to_uid(struct nfs_client *clp, const char *name, size_t namelen, __u32 *uid)
493 {
494         struct idmap *idmap = clp->cl_idmap;
495
496         return nfs_idmap_id(idmap, &idmap->idmap_user_hash, name, namelen, uid);
497 }
498
499 int nfs_map_group_to_gid(struct nfs_client *clp, const char *name, size_t namelen, __u32 *uid)
500 {
501         struct idmap *idmap = clp->cl_idmap;
502
503         return nfs_idmap_id(idmap, &idmap->idmap_group_hash, name, namelen, uid);
504 }
505
506 int nfs_map_uid_to_name(struct nfs_client *clp, __u32 uid, char *buf)
507 {
508         struct idmap *idmap = clp->cl_idmap;
509
510         return nfs_idmap_name(idmap, &idmap->idmap_user_hash, uid, buf);
511 }
512 int nfs_map_gid_to_group(struct nfs_client *clp, __u32 uid, char *buf)
513 {
514         struct idmap *idmap = clp->cl_idmap;
515
516         return nfs_idmap_name(idmap, &idmap->idmap_group_hash, uid, buf);
517 }
518