e3fdd2f45b01f581d9ad165aea047e8d5a2fbf2b
[releases.git] / nfs4idmap.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 #include <linux/types.h>
37 #include <linux/parser.h>
38 #include <linux/fs.h>
39 #include <net/net_namespace.h>
40 #include <linux/sunrpc/rpc_pipe_fs.h>
41 #include <linux/nfs_fs.h>
42 #include <linux/nfs_fs_sb.h>
43 #include <linux/key.h>
44 #include <linux/keyctl.h>
45 #include <linux/key-type.h>
46 #include <keys/user-type.h>
47 #include <keys/request_key_auth-type.h>
48 #include <linux/module.h>
49 #include <linux/user_namespace.h>
50
51 #include "internal.h"
52 #include "netns.h"
53 #include "nfs4idmap.h"
54 #include "nfs4trace.h"
55
56 #define NFS_UINT_MAXLEN 11
57
58 static const struct cred *id_resolver_cache;
59 static struct key_type key_type_id_resolver_legacy;
60
61 struct idmap_legacy_upcalldata {
62         struct rpc_pipe_msg pipe_msg;
63         struct idmap_msg idmap_msg;
64         struct key      *authkey;
65         struct idmap *idmap;
66 };
67
68 struct idmap {
69         struct rpc_pipe_dir_object idmap_pdo;
70         struct rpc_pipe         *idmap_pipe;
71         struct idmap_legacy_upcalldata *idmap_upcall_data;
72         struct mutex            idmap_mutex;
73         struct user_namespace   *user_ns;
74 };
75
76 static struct user_namespace *idmap_userns(const struct idmap *idmap)
77 {
78         if (idmap && idmap->user_ns)
79                 return idmap->user_ns;
80         return &init_user_ns;
81 }
82
83 /**
84  * nfs_fattr_init_names - initialise the nfs_fattr owner_name/group_name fields
85  * @fattr: fully initialised struct nfs_fattr
86  * @owner_name: owner name string cache
87  * @group_name: group name string cache
88  */
89 void nfs_fattr_init_names(struct nfs_fattr *fattr,
90                 struct nfs4_string *owner_name,
91                 struct nfs4_string *group_name)
92 {
93         fattr->owner_name = owner_name;
94         fattr->group_name = group_name;
95 }
96
97 static void nfs_fattr_free_owner_name(struct nfs_fattr *fattr)
98 {
99         fattr->valid &= ~NFS_ATTR_FATTR_OWNER_NAME;
100         kfree(fattr->owner_name->data);
101 }
102
103 static void nfs_fattr_free_group_name(struct nfs_fattr *fattr)
104 {
105         fattr->valid &= ~NFS_ATTR_FATTR_GROUP_NAME;
106         kfree(fattr->group_name->data);
107 }
108
109 static bool nfs_fattr_map_owner_name(struct nfs_server *server, struct nfs_fattr *fattr)
110 {
111         struct nfs4_string *owner = fattr->owner_name;
112         kuid_t uid;
113
114         if (!(fattr->valid & NFS_ATTR_FATTR_OWNER_NAME))
115                 return false;
116         if (nfs_map_name_to_uid(server, owner->data, owner->len, &uid) == 0) {
117                 fattr->uid = uid;
118                 fattr->valid |= NFS_ATTR_FATTR_OWNER;
119         }
120         return true;
121 }
122
123 static bool nfs_fattr_map_group_name(struct nfs_server *server, struct nfs_fattr *fattr)
124 {
125         struct nfs4_string *group = fattr->group_name;
126         kgid_t gid;
127
128         if (!(fattr->valid & NFS_ATTR_FATTR_GROUP_NAME))
129                 return false;
130         if (nfs_map_group_to_gid(server, group->data, group->len, &gid) == 0) {
131                 fattr->gid = gid;
132                 fattr->valid |= NFS_ATTR_FATTR_GROUP;
133         }
134         return true;
135 }
136
137 /**
138  * nfs_fattr_free_names - free up the NFSv4 owner and group strings
139  * @fattr: a fully initialised nfs_fattr structure
140  */
141 void nfs_fattr_free_names(struct nfs_fattr *fattr)
142 {
143         if (fattr->valid & NFS_ATTR_FATTR_OWNER_NAME)
144                 nfs_fattr_free_owner_name(fattr);
145         if (fattr->valid & NFS_ATTR_FATTR_GROUP_NAME)
146                 nfs_fattr_free_group_name(fattr);
147 }
148
149 /**
150  * nfs_fattr_map_and_free_names - map owner/group strings into uid/gid and free
151  * @server: pointer to the filesystem nfs_server structure
152  * @fattr: a fully initialised nfs_fattr structure
153  *
154  * This helper maps the cached NFSv4 owner/group strings in fattr into
155  * their numeric uid/gid equivalents, and then frees the cached strings.
156  */
157 void nfs_fattr_map_and_free_names(struct nfs_server *server, struct nfs_fattr *fattr)
158 {
159         if (nfs_fattr_map_owner_name(server, fattr))
160                 nfs_fattr_free_owner_name(fattr);
161         if (nfs_fattr_map_group_name(server, fattr))
162                 nfs_fattr_free_group_name(fattr);
163 }
164
165 int nfs_map_string_to_numeric(const char *name, size_t namelen, __u32 *res)
166 {
167         unsigned long val;
168         char buf[16];
169
170         if (memchr(name, '@', namelen) != NULL || namelen >= sizeof(buf))
171                 return 0;
172         memcpy(buf, name, namelen);
173         buf[namelen] = '\0';
174         if (kstrtoul(buf, 0, &val) != 0)
175                 return 0;
176         *res = val;
177         return 1;
178 }
179 EXPORT_SYMBOL_GPL(nfs_map_string_to_numeric);
180
181 static int nfs_map_numeric_to_string(__u32 id, char *buf, size_t buflen)
182 {
183         return snprintf(buf, buflen, "%u", id);
184 }
185
186 static struct key_type key_type_id_resolver = {
187         .name           = "id_resolver",
188         .preparse       = user_preparse,
189         .free_preparse  = user_free_preparse,
190         .instantiate    = generic_key_instantiate,
191         .revoke         = user_revoke,
192         .destroy        = user_destroy,
193         .describe       = user_describe,
194         .read           = user_read,
195 };
196
197 int nfs_idmap_init(void)
198 {
199         struct cred *cred;
200         struct key *keyring;
201         int ret = 0;
202
203         printk(KERN_NOTICE "NFS: Registering the %s key type\n",
204                 key_type_id_resolver.name);
205
206         cred = prepare_kernel_cred(NULL);
207         if (!cred)
208                 return -ENOMEM;
209
210         keyring = keyring_alloc(".id_resolver",
211                                 GLOBAL_ROOT_UID, GLOBAL_ROOT_GID, cred,
212                                 (KEY_POS_ALL & ~KEY_POS_SETATTR) |
213                                 KEY_USR_VIEW | KEY_USR_READ,
214                                 KEY_ALLOC_NOT_IN_QUOTA, NULL, NULL);
215         if (IS_ERR(keyring)) {
216                 ret = PTR_ERR(keyring);
217                 goto failed_put_cred;
218         }
219
220         ret = register_key_type(&key_type_id_resolver);
221         if (ret < 0)
222                 goto failed_put_key;
223
224         ret = register_key_type(&key_type_id_resolver_legacy);
225         if (ret < 0)
226                 goto failed_reg_legacy;
227
228         set_bit(KEY_FLAG_ROOT_CAN_CLEAR, &keyring->flags);
229         cred->thread_keyring = keyring;
230         cred->jit_keyring = KEY_REQKEY_DEFL_THREAD_KEYRING;
231         id_resolver_cache = cred;
232         return 0;
233
234 failed_reg_legacy:
235         unregister_key_type(&key_type_id_resolver);
236 failed_put_key:
237         key_put(keyring);
238 failed_put_cred:
239         put_cred(cred);
240         return ret;
241 }
242
243 void nfs_idmap_quit(void)
244 {
245         key_revoke(id_resolver_cache->thread_keyring);
246         unregister_key_type(&key_type_id_resolver);
247         unregister_key_type(&key_type_id_resolver_legacy);
248         put_cred(id_resolver_cache);
249 }
250
251 /*
252  * Assemble the description to pass to request_key()
253  * This function will allocate a new string and update dest to point
254  * at it.  The caller is responsible for freeing dest.
255  *
256  * On error 0 is returned.  Otherwise, the length of dest is returned.
257  */
258 static ssize_t nfs_idmap_get_desc(const char *name, size_t namelen,
259                                 const char *type, size_t typelen, char **desc)
260 {
261         char *cp;
262         size_t desclen = typelen + namelen + 2;
263
264         *desc = kmalloc(desclen, GFP_KERNEL);
265         if (!*desc)
266                 return -ENOMEM;
267
268         cp = *desc;
269         memcpy(cp, type, typelen);
270         cp += typelen;
271         *cp++ = ':';
272
273         memcpy(cp, name, namelen);
274         cp += namelen;
275         *cp = '\0';
276         return desclen;
277 }
278
279 static struct key *nfs_idmap_request_key(const char *name, size_t namelen,
280                                          const char *type, struct idmap *idmap)
281 {
282         char *desc;
283         struct key *rkey = ERR_PTR(-EAGAIN);
284         ssize_t ret;
285
286         ret = nfs_idmap_get_desc(name, namelen, type, strlen(type), &desc);
287         if (ret < 0)
288                 return ERR_PTR(ret);
289
290         if (!idmap->user_ns || idmap->user_ns == &init_user_ns)
291                 rkey = request_key(&key_type_id_resolver, desc, "");
292         if (IS_ERR(rkey)) {
293                 mutex_lock(&idmap->idmap_mutex);
294                 rkey = request_key_with_auxdata(&key_type_id_resolver_legacy,
295                                                 desc, NULL, "", 0, idmap);
296                 mutex_unlock(&idmap->idmap_mutex);
297         }
298         if (!IS_ERR(rkey))
299                 set_bit(KEY_FLAG_ROOT_CAN_INVAL, &rkey->flags);
300
301         kfree(desc);
302         return rkey;
303 }
304
305 static ssize_t nfs_idmap_get_key(const char *name, size_t namelen,
306                                  const char *type, void *data,
307                                  size_t data_size, struct idmap *idmap)
308 {
309         const struct cred *saved_cred;
310         struct key *rkey;
311         const struct user_key_payload *payload;
312         ssize_t ret;
313
314         saved_cred = override_creds(id_resolver_cache);
315         rkey = nfs_idmap_request_key(name, namelen, type, idmap);
316         revert_creds(saved_cred);
317
318         if (IS_ERR(rkey)) {
319                 ret = PTR_ERR(rkey);
320                 goto out;
321         }
322
323         rcu_read_lock();
324         rkey->perm |= KEY_USR_VIEW;
325
326         ret = key_validate(rkey);
327         if (ret < 0)
328                 goto out_up;
329
330         payload = user_key_payload_rcu(rkey);
331         if (IS_ERR_OR_NULL(payload)) {
332                 ret = PTR_ERR(payload);
333                 goto out_up;
334         }
335
336         ret = payload->datalen;
337         if (ret > 0 && ret <= data_size)
338                 memcpy(data, payload->data, ret);
339         else
340                 ret = -EINVAL;
341
342 out_up:
343         rcu_read_unlock();
344         key_put(rkey);
345 out:
346         return ret;
347 }
348
349 /* ID -> Name */
350 static ssize_t nfs_idmap_lookup_name(__u32 id, const char *type, char *buf,
351                                      size_t buflen, struct idmap *idmap)
352 {
353         char id_str[NFS_UINT_MAXLEN];
354         int id_len;
355         ssize_t ret;
356
357         id_len = nfs_map_numeric_to_string(id, id_str, sizeof(id_str));
358         ret = nfs_idmap_get_key(id_str, id_len, type, buf, buflen, idmap);
359         if (ret < 0)
360                 return -EINVAL;
361         return ret;
362 }
363
364 /* Name -> ID */
365 static int nfs_idmap_lookup_id(const char *name, size_t namelen, const char *type,
366                                __u32 *id, struct idmap *idmap)
367 {
368         char id_str[NFS_UINT_MAXLEN];
369         long id_long;
370         ssize_t data_size;
371         int ret = 0;
372
373         data_size = nfs_idmap_get_key(name, namelen, type, id_str, NFS_UINT_MAXLEN, idmap);
374         if (data_size <= 0) {
375                 ret = -EINVAL;
376         } else {
377                 ret = kstrtol(id_str, 10, &id_long);
378                 if (!ret)
379                         *id = (__u32)id_long;
380         }
381         return ret;
382 }
383
384 /* idmap classic begins here */
385
386 enum {
387         Opt_find_uid, Opt_find_gid, Opt_find_user, Opt_find_group, Opt_find_err
388 };
389
390 static const match_table_t nfs_idmap_tokens = {
391         { Opt_find_uid, "uid:%s" },
392         { Opt_find_gid, "gid:%s" },
393         { Opt_find_user, "user:%s" },
394         { Opt_find_group, "group:%s" },
395         { Opt_find_err, NULL }
396 };
397
398 static int nfs_idmap_legacy_upcall(struct key *, void *);
399 static ssize_t idmap_pipe_downcall(struct file *, const char __user *,
400                                    size_t);
401 static void idmap_release_pipe(struct inode *);
402 static void idmap_pipe_destroy_msg(struct rpc_pipe_msg *);
403
404 static const struct rpc_pipe_ops idmap_upcall_ops = {
405         .upcall         = rpc_pipe_generic_upcall,
406         .downcall       = idmap_pipe_downcall,
407         .release_pipe   = idmap_release_pipe,
408         .destroy_msg    = idmap_pipe_destroy_msg,
409 };
410
411 static struct key_type key_type_id_resolver_legacy = {
412         .name           = "id_legacy",
413         .preparse       = user_preparse,
414         .free_preparse  = user_free_preparse,
415         .instantiate    = generic_key_instantiate,
416         .revoke         = user_revoke,
417         .destroy        = user_destroy,
418         .describe       = user_describe,
419         .read           = user_read,
420         .request_key    = nfs_idmap_legacy_upcall,
421 };
422
423 static void nfs_idmap_pipe_destroy(struct dentry *dir,
424                 struct rpc_pipe_dir_object *pdo)
425 {
426         struct idmap *idmap = pdo->pdo_data;
427         struct rpc_pipe *pipe = idmap->idmap_pipe;
428
429         if (pipe->dentry) {
430                 rpc_unlink(pipe->dentry);
431                 pipe->dentry = NULL;
432         }
433 }
434
435 static int nfs_idmap_pipe_create(struct dentry *dir,
436                 struct rpc_pipe_dir_object *pdo)
437 {
438         struct idmap *idmap = pdo->pdo_data;
439         struct rpc_pipe *pipe = idmap->idmap_pipe;
440         struct dentry *dentry;
441
442         dentry = rpc_mkpipe_dentry(dir, "idmap", idmap, pipe);
443         if (IS_ERR(dentry))
444                 return PTR_ERR(dentry);
445         pipe->dentry = dentry;
446         return 0;
447 }
448
449 static const struct rpc_pipe_dir_object_ops nfs_idmap_pipe_dir_object_ops = {
450         .create = nfs_idmap_pipe_create,
451         .destroy = nfs_idmap_pipe_destroy,
452 };
453
454 int
455 nfs_idmap_new(struct nfs_client *clp)
456 {
457         struct idmap *idmap;
458         struct rpc_pipe *pipe;
459         int error;
460
461         idmap = kzalloc(sizeof(*idmap), GFP_KERNEL);
462         if (idmap == NULL)
463                 return -ENOMEM;
464
465         mutex_init(&idmap->idmap_mutex);
466         idmap->user_ns = get_user_ns(clp->cl_rpcclient->cl_cred->user_ns);
467
468         rpc_init_pipe_dir_object(&idmap->idmap_pdo,
469                         &nfs_idmap_pipe_dir_object_ops,
470                         idmap);
471
472         pipe = rpc_mkpipe_data(&idmap_upcall_ops, 0);
473         if (IS_ERR(pipe)) {
474                 error = PTR_ERR(pipe);
475                 goto err;
476         }
477         idmap->idmap_pipe = pipe;
478
479         error = rpc_add_pipe_dir_object(clp->cl_net,
480                         &clp->cl_rpcclient->cl_pipedir_objects,
481                         &idmap->idmap_pdo);
482         if (error)
483                 goto err_destroy_pipe;
484
485         clp->cl_idmap = idmap;
486         return 0;
487 err_destroy_pipe:
488         rpc_destroy_pipe_data(idmap->idmap_pipe);
489 err:
490         put_user_ns(idmap->user_ns);
491         kfree(idmap);
492         return error;
493 }
494
495 void
496 nfs_idmap_delete(struct nfs_client *clp)
497 {
498         struct idmap *idmap = clp->cl_idmap;
499
500         if (!idmap)
501                 return;
502         clp->cl_idmap = NULL;
503         rpc_remove_pipe_dir_object(clp->cl_net,
504                         &clp->cl_rpcclient->cl_pipedir_objects,
505                         &idmap->idmap_pdo);
506         rpc_destroy_pipe_data(idmap->idmap_pipe);
507         put_user_ns(idmap->user_ns);
508         kfree(idmap);
509 }
510
511 static int nfs_idmap_prepare_message(char *desc, struct idmap *idmap,
512                                      struct idmap_msg *im,
513                                      struct rpc_pipe_msg *msg)
514 {
515         substring_t substr;
516         int token, ret;
517
518         im->im_type = IDMAP_TYPE_GROUP;
519         token = match_token(desc, nfs_idmap_tokens, &substr);
520
521         switch (token) {
522         case Opt_find_uid:
523                 im->im_type = IDMAP_TYPE_USER;
524                 fallthrough;
525         case Opt_find_gid:
526                 im->im_conv = IDMAP_CONV_NAMETOID;
527                 ret = match_strlcpy(im->im_name, &substr, IDMAP_NAMESZ);
528                 break;
529
530         case Opt_find_user:
531                 im->im_type = IDMAP_TYPE_USER;
532                 fallthrough;
533         case Opt_find_group:
534                 im->im_conv = IDMAP_CONV_IDTONAME;
535                 ret = match_int(&substr, &im->im_id);
536                 if (ret)
537                         goto out;
538                 break;
539
540         default:
541                 ret = -EINVAL;
542                 goto out;
543         }
544
545         msg->data = im;
546         msg->len  = sizeof(struct idmap_msg);
547
548 out:
549         return ret;
550 }
551
552 static bool
553 nfs_idmap_prepare_pipe_upcall(struct idmap *idmap,
554                 struct idmap_legacy_upcalldata *data)
555 {
556         if (idmap->idmap_upcall_data != NULL) {
557                 WARN_ON_ONCE(1);
558                 return false;
559         }
560         idmap->idmap_upcall_data = data;
561         return true;
562 }
563
564 static void nfs_idmap_complete_pipe_upcall(struct idmap_legacy_upcalldata *data,
565                                            int ret)
566 {
567         complete_request_key(data->authkey, ret);
568         key_put(data->authkey);
569         kfree(data);
570 }
571
572 static void nfs_idmap_abort_pipe_upcall(struct idmap *idmap,
573                                         struct idmap_legacy_upcalldata *data,
574                                         int ret)
575 {
576         if (cmpxchg(&idmap->idmap_upcall_data, data, NULL) == data)
577                 nfs_idmap_complete_pipe_upcall(data, ret);
578 }
579
580 static int nfs_idmap_legacy_upcall(struct key *authkey, void *aux)
581 {
582         struct idmap_legacy_upcalldata *data;
583         struct request_key_auth *rka = get_request_key_auth(authkey);
584         struct rpc_pipe_msg *msg;
585         struct idmap_msg *im;
586         struct idmap *idmap = aux;
587         struct key *key = rka->target_key;
588         int ret = -ENOKEY;
589
590         if (!aux)
591                 goto out1;
592
593         /* msg and im are freed in idmap_pipe_destroy_msg */
594         ret = -ENOMEM;
595         data = kzalloc(sizeof(*data), GFP_KERNEL);
596         if (!data)
597                 goto out1;
598
599         msg = &data->pipe_msg;
600         im = &data->idmap_msg;
601         data->idmap = idmap;
602         data->authkey = key_get(authkey);
603
604         ret = nfs_idmap_prepare_message(key->description, idmap, im, msg);
605         if (ret < 0)
606                 goto out2;
607
608         ret = -EAGAIN;
609         if (!nfs_idmap_prepare_pipe_upcall(idmap, data))
610                 goto out2;
611
612         ret = rpc_queue_upcall(idmap->idmap_pipe, msg);
613         if (ret < 0)
614                 nfs_idmap_abort_pipe_upcall(idmap, data, ret);
615
616         return ret;
617 out2:
618         kfree(data);
619 out1:
620         complete_request_key(authkey, ret);
621         return ret;
622 }
623
624 static int nfs_idmap_instantiate(struct key *key, struct key *authkey, char *data, size_t datalen)
625 {
626         return key_instantiate_and_link(key, data, datalen,
627                                         id_resolver_cache->thread_keyring,
628                                         authkey);
629 }
630
631 static int nfs_idmap_read_and_verify_message(struct idmap_msg *im,
632                 struct idmap_msg *upcall,
633                 struct key *key, struct key *authkey)
634 {
635         char id_str[NFS_UINT_MAXLEN];
636         size_t len;
637         int ret = -ENOKEY;
638
639         /* ret = -ENOKEY */
640         if (upcall->im_type != im->im_type || upcall->im_conv != im->im_conv)
641                 goto out;
642         switch (im->im_conv) {
643         case IDMAP_CONV_NAMETOID:
644                 if (strcmp(upcall->im_name, im->im_name) != 0)
645                         break;
646                 /* Note: here we store the NUL terminator too */
647                 len = 1 + nfs_map_numeric_to_string(im->im_id, id_str,
648                                                     sizeof(id_str));
649                 ret = nfs_idmap_instantiate(key, authkey, id_str, len);
650                 break;
651         case IDMAP_CONV_IDTONAME:
652                 if (upcall->im_id != im->im_id)
653                         break;
654                 len = strlen(im->im_name);
655                 ret = nfs_idmap_instantiate(key, authkey, im->im_name, len);
656                 break;
657         default:
658                 ret = -EINVAL;
659         }
660 out:
661         return ret;
662 }
663
664 static ssize_t
665 idmap_pipe_downcall(struct file *filp, const char __user *src, size_t mlen)
666 {
667         struct request_key_auth *rka;
668         struct rpc_inode *rpci = RPC_I(file_inode(filp));
669         struct idmap *idmap = (struct idmap *)rpci->private;
670         struct idmap_legacy_upcalldata *data;
671         struct key *authkey;
672         struct idmap_msg im;
673         size_t namelen_in;
674         int ret = -ENOKEY;
675
676         /* If instantiation is successful, anyone waiting for key construction
677          * will have been woken up and someone else may now have used
678          * idmap_key_cons - so after this point we may no longer touch it.
679          */
680         data = xchg(&idmap->idmap_upcall_data, NULL);
681         if (data == NULL)
682                 goto out_noupcall;
683
684         authkey = data->authkey;
685         rka = get_request_key_auth(authkey);
686
687         if (mlen != sizeof(im)) {
688                 ret = -ENOSPC;
689                 goto out;
690         }
691
692         if (copy_from_user(&im, src, mlen) != 0) {
693                 ret = -EFAULT;
694                 goto out;
695         }
696
697         if (!(im.im_status & IDMAP_STATUS_SUCCESS)) {
698                 ret = -ENOKEY;
699                 goto out;
700         }
701
702         namelen_in = strnlen(im.im_name, IDMAP_NAMESZ);
703         if (namelen_in == 0 || namelen_in == IDMAP_NAMESZ) {
704                 ret = -EINVAL;
705                 goto out;
706         }
707
708         ret = nfs_idmap_read_and_verify_message(&im, &data->idmap_msg,
709                                                 rka->target_key, authkey);
710         if (ret >= 0) {
711                 key_set_timeout(rka->target_key, nfs_idmap_cache_timeout);
712                 ret = mlen;
713         }
714
715 out:
716         nfs_idmap_complete_pipe_upcall(data, ret);
717 out_noupcall:
718         return ret;
719 }
720
721 static void
722 idmap_pipe_destroy_msg(struct rpc_pipe_msg *msg)
723 {
724         struct idmap_legacy_upcalldata *data = container_of(msg,
725                         struct idmap_legacy_upcalldata,
726                         pipe_msg);
727         struct idmap *idmap = data->idmap;
728
729         if (msg->errno)
730                 nfs_idmap_abort_pipe_upcall(idmap, data, msg->errno);
731 }
732
733 static void
734 idmap_release_pipe(struct inode *inode)
735 {
736         struct rpc_inode *rpci = RPC_I(inode);
737         struct idmap *idmap = (struct idmap *)rpci->private;
738         struct idmap_legacy_upcalldata *data;
739
740         data = xchg(&idmap->idmap_upcall_data, NULL);
741         if (data)
742                 nfs_idmap_complete_pipe_upcall(data, -EPIPE);
743 }
744
745 int nfs_map_name_to_uid(const struct nfs_server *server, const char *name, size_t namelen, kuid_t *uid)
746 {
747         struct idmap *idmap = server->nfs_client->cl_idmap;
748         __u32 id = -1;
749         int ret = 0;
750
751         if (!nfs_map_string_to_numeric(name, namelen, &id))
752                 ret = nfs_idmap_lookup_id(name, namelen, "uid", &id, idmap);
753         if (ret == 0) {
754                 *uid = make_kuid(idmap_userns(idmap), id);
755                 if (!uid_valid(*uid))
756                         ret = -ERANGE;
757         }
758         trace_nfs4_map_name_to_uid(name, namelen, id, ret);
759         return ret;
760 }
761
762 int nfs_map_group_to_gid(const struct nfs_server *server, const char *name, size_t namelen, kgid_t *gid)
763 {
764         struct idmap *idmap = server->nfs_client->cl_idmap;
765         __u32 id = -1;
766         int ret = 0;
767
768         if (!nfs_map_string_to_numeric(name, namelen, &id))
769                 ret = nfs_idmap_lookup_id(name, namelen, "gid", &id, idmap);
770         if (ret == 0) {
771                 *gid = make_kgid(idmap_userns(idmap), id);
772                 if (!gid_valid(*gid))
773                         ret = -ERANGE;
774         }
775         trace_nfs4_map_group_to_gid(name, namelen, id, ret);
776         return ret;
777 }
778
779 int nfs_map_uid_to_name(const struct nfs_server *server, kuid_t uid, char *buf, size_t buflen)
780 {
781         struct idmap *idmap = server->nfs_client->cl_idmap;
782         int ret = -EINVAL;
783         __u32 id;
784
785         id = from_kuid_munged(idmap_userns(idmap), uid);
786         if (!(server->caps & NFS_CAP_UIDGID_NOMAP))
787                 ret = nfs_idmap_lookup_name(id, "user", buf, buflen, idmap);
788         if (ret < 0)
789                 ret = nfs_map_numeric_to_string(id, buf, buflen);
790         trace_nfs4_map_uid_to_name(buf, ret, id, ret);
791         return ret;
792 }
793 int nfs_map_gid_to_group(const struct nfs_server *server, kgid_t gid, char *buf, size_t buflen)
794 {
795         struct idmap *idmap = server->nfs_client->cl_idmap;
796         int ret = -EINVAL;
797         __u32 id;
798
799         id = from_kgid_munged(idmap_userns(idmap), gid);
800         if (!(server->caps & NFS_CAP_UIDGID_NOMAP))
801                 ret = nfs_idmap_lookup_name(id, "group", buf, buflen, idmap);
802         if (ret < 0)
803                 ret = nfs_map_numeric_to_string(id, buf, buflen);
804         trace_nfs4_map_gid_to_group(buf, ret, id, ret);
805         return ret;
806 }