Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris...
[~shefty/rdma-dev.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 #include <linux/types.h>
37 #include <linux/parser.h>
38 #include <linux/fs.h>
39 #include <linux/nfs_idmap.h>
40 #include <net/net_namespace.h>
41 #include <linux/sunrpc/rpc_pipe_fs.h>
42 #include <linux/nfs_fs.h>
43 #include <linux/nfs_fs_sb.h>
44 #include <linux/key.h>
45 #include <linux/keyctl.h>
46 #include <linux/key-type.h>
47 #include <keys/user-type.h>
48 #include <linux/module.h>
49
50 #include "internal.h"
51 #include "netns.h"
52
53 #define NFS_UINT_MAXLEN 11
54
55 static const struct cred *id_resolver_cache;
56 static struct key_type key_type_id_resolver_legacy;
57
58 struct idmap_legacy_upcalldata {
59         struct rpc_pipe_msg pipe_msg;
60         struct idmap_msg idmap_msg;
61         struct key_construction *key_cons;
62         struct idmap *idmap;
63 };
64
65 struct idmap {
66         struct rpc_pipe         *idmap_pipe;
67         struct idmap_legacy_upcalldata *idmap_upcall_data;
68         struct mutex            idmap_mutex;
69 };
70
71 /**
72  * nfs_fattr_init_names - initialise the nfs_fattr owner_name/group_name fields
73  * @fattr: fully initialised struct nfs_fattr
74  * @owner_name: owner name string cache
75  * @group_name: group name string cache
76  */
77 void nfs_fattr_init_names(struct nfs_fattr *fattr,
78                 struct nfs4_string *owner_name,
79                 struct nfs4_string *group_name)
80 {
81         fattr->owner_name = owner_name;
82         fattr->group_name = group_name;
83 }
84
85 static void nfs_fattr_free_owner_name(struct nfs_fattr *fattr)
86 {
87         fattr->valid &= ~NFS_ATTR_FATTR_OWNER_NAME;
88         kfree(fattr->owner_name->data);
89 }
90
91 static void nfs_fattr_free_group_name(struct nfs_fattr *fattr)
92 {
93         fattr->valid &= ~NFS_ATTR_FATTR_GROUP_NAME;
94         kfree(fattr->group_name->data);
95 }
96
97 static bool nfs_fattr_map_owner_name(struct nfs_server *server, struct nfs_fattr *fattr)
98 {
99         struct nfs4_string *owner = fattr->owner_name;
100         __u32 uid;
101
102         if (!(fattr->valid & NFS_ATTR_FATTR_OWNER_NAME))
103                 return false;
104         if (nfs_map_name_to_uid(server, owner->data, owner->len, &uid) == 0) {
105                 fattr->uid = uid;
106                 fattr->valid |= NFS_ATTR_FATTR_OWNER;
107         }
108         return true;
109 }
110
111 static bool nfs_fattr_map_group_name(struct nfs_server *server, struct nfs_fattr *fattr)
112 {
113         struct nfs4_string *group = fattr->group_name;
114         __u32 gid;
115
116         if (!(fattr->valid & NFS_ATTR_FATTR_GROUP_NAME))
117                 return false;
118         if (nfs_map_group_to_gid(server, group->data, group->len, &gid) == 0) {
119                 fattr->gid = gid;
120                 fattr->valid |= NFS_ATTR_FATTR_GROUP;
121         }
122         return true;
123 }
124
125 /**
126  * nfs_fattr_free_names - free up the NFSv4 owner and group strings
127  * @fattr: a fully initialised nfs_fattr structure
128  */
129 void nfs_fattr_free_names(struct nfs_fattr *fattr)
130 {
131         if (fattr->valid & NFS_ATTR_FATTR_OWNER_NAME)
132                 nfs_fattr_free_owner_name(fattr);
133         if (fattr->valid & NFS_ATTR_FATTR_GROUP_NAME)
134                 nfs_fattr_free_group_name(fattr);
135 }
136
137 /**
138  * nfs_fattr_map_and_free_names - map owner/group strings into uid/gid and free
139  * @server: pointer to the filesystem nfs_server structure
140  * @fattr: a fully initialised nfs_fattr structure
141  *
142  * This helper maps the cached NFSv4 owner/group strings in fattr into
143  * their numeric uid/gid equivalents, and then frees the cached strings.
144  */
145 void nfs_fattr_map_and_free_names(struct nfs_server *server, struct nfs_fattr *fattr)
146 {
147         if (nfs_fattr_map_owner_name(server, fattr))
148                 nfs_fattr_free_owner_name(fattr);
149         if (nfs_fattr_map_group_name(server, fattr))
150                 nfs_fattr_free_group_name(fattr);
151 }
152
153 static int nfs_map_string_to_numeric(const char *name, size_t namelen, __u32 *res)
154 {
155         unsigned long val;
156         char buf[16];
157
158         if (memchr(name, '@', namelen) != NULL || namelen >= sizeof(buf))
159                 return 0;
160         memcpy(buf, name, namelen);
161         buf[namelen] = '\0';
162         if (kstrtoul(buf, 0, &val) != 0)
163                 return 0;
164         *res = val;
165         return 1;
166 }
167
168 static int nfs_map_numeric_to_string(__u32 id, char *buf, size_t buflen)
169 {
170         return snprintf(buf, buflen, "%u", id);
171 }
172
173 static struct key_type key_type_id_resolver = {
174         .name           = "id_resolver",
175         .instantiate    = user_instantiate,
176         .match          = user_match,
177         .revoke         = user_revoke,
178         .destroy        = user_destroy,
179         .describe       = user_describe,
180         .read           = user_read,
181 };
182
183 static int nfs_idmap_init_keyring(void)
184 {
185         struct cred *cred;
186         struct key *keyring;
187         int ret = 0;
188
189         printk(KERN_NOTICE "NFS: Registering the %s key type\n",
190                 key_type_id_resolver.name);
191
192         cred = prepare_kernel_cred(NULL);
193         if (!cred)
194                 return -ENOMEM;
195
196         keyring = keyring_alloc(".id_resolver", 0, 0, cred,
197                                 (KEY_POS_ALL & ~KEY_POS_SETATTR) |
198                                 KEY_USR_VIEW | KEY_USR_READ,
199                                 KEY_ALLOC_NOT_IN_QUOTA, NULL);
200         if (IS_ERR(keyring)) {
201                 ret = PTR_ERR(keyring);
202                 goto failed_put_cred;
203         }
204
205         ret = register_key_type(&key_type_id_resolver);
206         if (ret < 0)
207                 goto failed_put_key;
208
209         ret = register_key_type(&key_type_id_resolver_legacy);
210         if (ret < 0)
211                 goto failed_reg_legacy;
212
213         set_bit(KEY_FLAG_ROOT_CAN_CLEAR, &keyring->flags);
214         cred->thread_keyring = keyring;
215         cred->jit_keyring = KEY_REQKEY_DEFL_THREAD_KEYRING;
216         id_resolver_cache = cred;
217         return 0;
218
219 failed_reg_legacy:
220         unregister_key_type(&key_type_id_resolver);
221 failed_put_key:
222         key_put(keyring);
223 failed_put_cred:
224         put_cred(cred);
225         return ret;
226 }
227
228 static void nfs_idmap_quit_keyring(void)
229 {
230         key_revoke(id_resolver_cache->thread_keyring);
231         unregister_key_type(&key_type_id_resolver);
232         unregister_key_type(&key_type_id_resolver_legacy);
233         put_cred(id_resolver_cache);
234 }
235
236 /*
237  * Assemble the description to pass to request_key()
238  * This function will allocate a new string and update dest to point
239  * at it.  The caller is responsible for freeing dest.
240  *
241  * On error 0 is returned.  Otherwise, the length of dest is returned.
242  */
243 static ssize_t nfs_idmap_get_desc(const char *name, size_t namelen,
244                                 const char *type, size_t typelen, char **desc)
245 {
246         char *cp;
247         size_t desclen = typelen + namelen + 2;
248
249         *desc = kmalloc(desclen, GFP_KERNEL);
250         if (!*desc)
251                 return -ENOMEM;
252
253         cp = *desc;
254         memcpy(cp, type, typelen);
255         cp += typelen;
256         *cp++ = ':';
257
258         memcpy(cp, name, namelen);
259         cp += namelen;
260         *cp = '\0';
261         return desclen;
262 }
263
264 static ssize_t nfs_idmap_request_key(struct key_type *key_type,
265                                      const char *name, size_t namelen,
266                                      const char *type, void *data,
267                                      size_t data_size, struct idmap *idmap)
268 {
269         const struct cred *saved_cred;
270         struct key *rkey;
271         char *desc;
272         struct user_key_payload *payload;
273         ssize_t ret;
274
275         ret = nfs_idmap_get_desc(name, namelen, type, strlen(type), &desc);
276         if (ret <= 0)
277                 goto out;
278
279         saved_cred = override_creds(id_resolver_cache);
280         if (idmap)
281                 rkey = request_key_with_auxdata(key_type, desc, "", 0, idmap);
282         else
283                 rkey = request_key(&key_type_id_resolver, desc, "");
284         revert_creds(saved_cred);
285
286         kfree(desc);
287         if (IS_ERR(rkey)) {
288                 ret = PTR_ERR(rkey);
289                 goto out;
290         }
291
292         rcu_read_lock();
293         rkey->perm |= KEY_USR_VIEW;
294
295         ret = key_validate(rkey);
296         if (ret < 0)
297                 goto out_up;
298
299         payload = rcu_dereference(rkey->payload.data);
300         if (IS_ERR_OR_NULL(payload)) {
301                 ret = PTR_ERR(payload);
302                 goto out_up;
303         }
304
305         ret = payload->datalen;
306         if (ret > 0 && ret <= data_size)
307                 memcpy(data, payload->data, ret);
308         else
309                 ret = -EINVAL;
310
311 out_up:
312         rcu_read_unlock();
313         key_put(rkey);
314 out:
315         return ret;
316 }
317
318 static ssize_t nfs_idmap_get_key(const char *name, size_t namelen,
319                                  const char *type, void *data,
320                                  size_t data_size, struct idmap *idmap)
321 {
322         ssize_t ret = nfs_idmap_request_key(&key_type_id_resolver,
323                                             name, namelen, type, data,
324                                             data_size, NULL);
325         if (ret < 0) {
326                 mutex_lock(&idmap->idmap_mutex);
327                 ret = nfs_idmap_request_key(&key_type_id_resolver_legacy,
328                                             name, namelen, type, data,
329                                             data_size, idmap);
330                 mutex_unlock(&idmap->idmap_mutex);
331         }
332         return ret;
333 }
334
335 /* ID -> Name */
336 static ssize_t nfs_idmap_lookup_name(__u32 id, const char *type, char *buf,
337                                      size_t buflen, struct idmap *idmap)
338 {
339         char id_str[NFS_UINT_MAXLEN];
340         int id_len;
341         ssize_t ret;
342
343         id_len = snprintf(id_str, sizeof(id_str), "%u", id);
344         ret = nfs_idmap_get_key(id_str, id_len, type, buf, buflen, idmap);
345         if (ret < 0)
346                 return -EINVAL;
347         return ret;
348 }
349
350 /* Name -> ID */
351 static int nfs_idmap_lookup_id(const char *name, size_t namelen, const char *type,
352                                __u32 *id, struct idmap *idmap)
353 {
354         char id_str[NFS_UINT_MAXLEN];
355         long id_long;
356         ssize_t data_size;
357         int ret = 0;
358
359         data_size = nfs_idmap_get_key(name, namelen, type, id_str, NFS_UINT_MAXLEN, idmap);
360         if (data_size <= 0) {
361                 ret = -EINVAL;
362         } else {
363                 ret = kstrtol(id_str, 10, &id_long);
364                 *id = (__u32)id_long;
365         }
366         return ret;
367 }
368
369 /* idmap classic begins here */
370
371 enum {
372         Opt_find_uid, Opt_find_gid, Opt_find_user, Opt_find_group, Opt_find_err
373 };
374
375 static const match_table_t nfs_idmap_tokens = {
376         { Opt_find_uid, "uid:%s" },
377         { Opt_find_gid, "gid:%s" },
378         { Opt_find_user, "user:%s" },
379         { Opt_find_group, "group:%s" },
380         { Opt_find_err, NULL }
381 };
382
383 static int nfs_idmap_legacy_upcall(struct key_construction *, const char *, void *);
384 static ssize_t idmap_pipe_downcall(struct file *, const char __user *,
385                                    size_t);
386 static void idmap_release_pipe(struct inode *);
387 static void idmap_pipe_destroy_msg(struct rpc_pipe_msg *);
388
389 static const struct rpc_pipe_ops idmap_upcall_ops = {
390         .upcall         = rpc_pipe_generic_upcall,
391         .downcall       = idmap_pipe_downcall,
392         .release_pipe   = idmap_release_pipe,
393         .destroy_msg    = idmap_pipe_destroy_msg,
394 };
395
396 static struct key_type key_type_id_resolver_legacy = {
397         .name           = "id_legacy",
398         .instantiate    = user_instantiate,
399         .match          = user_match,
400         .revoke         = user_revoke,
401         .destroy        = user_destroy,
402         .describe       = user_describe,
403         .read           = user_read,
404         .request_key    = nfs_idmap_legacy_upcall,
405 };
406
407 static void __nfs_idmap_unregister(struct rpc_pipe *pipe)
408 {
409         if (pipe->dentry)
410                 rpc_unlink(pipe->dentry);
411 }
412
413 static int __nfs_idmap_register(struct dentry *dir,
414                                      struct idmap *idmap,
415                                      struct rpc_pipe *pipe)
416 {
417         struct dentry *dentry;
418
419         dentry = rpc_mkpipe_dentry(dir, "idmap", idmap, pipe);
420         if (IS_ERR(dentry))
421                 return PTR_ERR(dentry);
422         pipe->dentry = dentry;
423         return 0;
424 }
425
426 static void nfs_idmap_unregister(struct nfs_client *clp,
427                                       struct rpc_pipe *pipe)
428 {
429         struct net *net = clp->cl_net;
430         struct super_block *pipefs_sb;
431
432         pipefs_sb = rpc_get_sb_net(net);
433         if (pipefs_sb) {
434                 __nfs_idmap_unregister(pipe);
435                 rpc_put_sb_net(net);
436         }
437 }
438
439 static int nfs_idmap_register(struct nfs_client *clp,
440                                    struct idmap *idmap,
441                                    struct rpc_pipe *pipe)
442 {
443         struct net *net = clp->cl_net;
444         struct super_block *pipefs_sb;
445         int err = 0;
446
447         pipefs_sb = rpc_get_sb_net(net);
448         if (pipefs_sb) {
449                 if (clp->cl_rpcclient->cl_dentry)
450                         err = __nfs_idmap_register(clp->cl_rpcclient->cl_dentry,
451                                                    idmap, pipe);
452                 rpc_put_sb_net(net);
453         }
454         return err;
455 }
456
457 int
458 nfs_idmap_new(struct nfs_client *clp)
459 {
460         struct idmap *idmap;
461         struct rpc_pipe *pipe;
462         int error;
463
464         idmap = kzalloc(sizeof(*idmap), GFP_KERNEL);
465         if (idmap == NULL)
466                 return -ENOMEM;
467
468         pipe = rpc_mkpipe_data(&idmap_upcall_ops, 0);
469         if (IS_ERR(pipe)) {
470                 error = PTR_ERR(pipe);
471                 kfree(idmap);
472                 return error;
473         }
474         error = nfs_idmap_register(clp, idmap, pipe);
475         if (error) {
476                 rpc_destroy_pipe_data(pipe);
477                 kfree(idmap);
478                 return error;
479         }
480         idmap->idmap_pipe = pipe;
481         mutex_init(&idmap->idmap_mutex);
482
483         clp->cl_idmap = idmap;
484         return 0;
485 }
486
487 void
488 nfs_idmap_delete(struct nfs_client *clp)
489 {
490         struct idmap *idmap = clp->cl_idmap;
491
492         if (!idmap)
493                 return;
494         nfs_idmap_unregister(clp, idmap->idmap_pipe);
495         rpc_destroy_pipe_data(idmap->idmap_pipe);
496         clp->cl_idmap = NULL;
497         kfree(idmap);
498 }
499
500 static int __rpc_pipefs_event(struct nfs_client *clp, unsigned long event,
501                               struct super_block *sb)
502 {
503         int err = 0;
504
505         switch (event) {
506         case RPC_PIPEFS_MOUNT:
507                 err = __nfs_idmap_register(clp->cl_rpcclient->cl_dentry,
508                                                 clp->cl_idmap,
509                                                 clp->cl_idmap->idmap_pipe);
510                 break;
511         case RPC_PIPEFS_UMOUNT:
512                 if (clp->cl_idmap->idmap_pipe) {
513                         struct dentry *parent;
514
515                         parent = clp->cl_idmap->idmap_pipe->dentry->d_parent;
516                         __nfs_idmap_unregister(clp->cl_idmap->idmap_pipe);
517                         /*
518                          * Note: This is a dirty hack. SUNRPC hook has been
519                          * called already but simple_rmdir() call for the
520                          * directory returned with error because of idmap pipe
521                          * inside. Thus now we have to remove this directory
522                          * here.
523                          */
524                         if (rpc_rmdir(parent))
525                                 printk(KERN_ERR "NFS: %s: failed to remove "
526                                         "clnt dir!\n", __func__);
527                 }
528                 break;
529         default:
530                 printk(KERN_ERR "NFS: %s: unknown event: %ld\n", __func__,
531                         event);
532                 return -ENOTSUPP;
533         }
534         return err;
535 }
536
537 static struct nfs_client *nfs_get_client_for_event(struct net *net, int event)
538 {
539         struct nfs_net *nn = net_generic(net, nfs_net_id);
540         struct dentry *cl_dentry;
541         struct nfs_client *clp;
542         int err;
543
544 restart:
545         spin_lock(&nn->nfs_client_lock);
546         list_for_each_entry(clp, &nn->nfs_client_list, cl_share_link) {
547                 /* Wait for initialisation to finish */
548                 if (clp->cl_cons_state == NFS_CS_INITING) {
549                         atomic_inc(&clp->cl_count);
550                         spin_unlock(&nn->nfs_client_lock);
551                         err = nfs_wait_client_init_complete(clp);
552                         nfs_put_client(clp);
553                         if (err)
554                                 return NULL;
555                         goto restart;
556                 }
557                 /* Skip nfs_clients that failed to initialise */
558                 if (clp->cl_cons_state < 0)
559                         continue;
560                 smp_rmb();
561                 if (clp->rpc_ops != &nfs_v4_clientops)
562                         continue;
563                 cl_dentry = clp->cl_idmap->idmap_pipe->dentry;
564                 if (((event == RPC_PIPEFS_MOUNT) && cl_dentry) ||
565                     ((event == RPC_PIPEFS_UMOUNT) && !cl_dentry))
566                         continue;
567                 atomic_inc(&clp->cl_count);
568                 spin_unlock(&nn->nfs_client_lock);
569                 return clp;
570         }
571         spin_unlock(&nn->nfs_client_lock);
572         return NULL;
573 }
574
575 static int rpc_pipefs_event(struct notifier_block *nb, unsigned long event,
576                             void *ptr)
577 {
578         struct super_block *sb = ptr;
579         struct nfs_client *clp;
580         int error = 0;
581
582         if (!try_module_get(THIS_MODULE))
583                 return 0;
584
585         while ((clp = nfs_get_client_for_event(sb->s_fs_info, event))) {
586                 error = __rpc_pipefs_event(clp, event, sb);
587                 nfs_put_client(clp);
588                 if (error)
589                         break;
590         }
591         module_put(THIS_MODULE);
592         return error;
593 }
594
595 #define PIPEFS_NFS_PRIO         1
596
597 static struct notifier_block nfs_idmap_block = {
598         .notifier_call  = rpc_pipefs_event,
599         .priority       = SUNRPC_PIPEFS_NFS_PRIO,
600 };
601
602 int nfs_idmap_init(void)
603 {
604         int ret;
605         ret = nfs_idmap_init_keyring();
606         if (ret != 0)
607                 goto out;
608         ret = rpc_pipefs_notifier_register(&nfs_idmap_block);
609         if (ret != 0)
610                 nfs_idmap_quit_keyring();
611 out:
612         return ret;
613 }
614
615 void nfs_idmap_quit(void)
616 {
617         rpc_pipefs_notifier_unregister(&nfs_idmap_block);
618         nfs_idmap_quit_keyring();
619 }
620
621 static int nfs_idmap_prepare_message(char *desc, struct idmap *idmap,
622                                      struct idmap_msg *im,
623                                      struct rpc_pipe_msg *msg)
624 {
625         substring_t substr;
626         int token, ret;
627
628         im->im_type = IDMAP_TYPE_GROUP;
629         token = match_token(desc, nfs_idmap_tokens, &substr);
630
631         switch (token) {
632         case Opt_find_uid:
633                 im->im_type = IDMAP_TYPE_USER;
634         case Opt_find_gid:
635                 im->im_conv = IDMAP_CONV_NAMETOID;
636                 ret = match_strlcpy(im->im_name, &substr, IDMAP_NAMESZ);
637                 break;
638
639         case Opt_find_user:
640                 im->im_type = IDMAP_TYPE_USER;
641         case Opt_find_group:
642                 im->im_conv = IDMAP_CONV_IDTONAME;
643                 ret = match_int(&substr, &im->im_id);
644                 break;
645
646         default:
647                 ret = -EINVAL;
648                 goto out;
649         }
650
651         msg->data = im;
652         msg->len  = sizeof(struct idmap_msg);
653
654 out:
655         return ret;
656 }
657
658 static bool
659 nfs_idmap_prepare_pipe_upcall(struct idmap *idmap,
660                 struct idmap_legacy_upcalldata *data)
661 {
662         if (idmap->idmap_upcall_data != NULL) {
663                 WARN_ON_ONCE(1);
664                 return false;
665         }
666         idmap->idmap_upcall_data = data;
667         return true;
668 }
669
670 static void
671 nfs_idmap_complete_pipe_upcall_locked(struct idmap *idmap, int ret)
672 {
673         struct key_construction *cons = idmap->idmap_upcall_data->key_cons;
674
675         kfree(idmap->idmap_upcall_data);
676         idmap->idmap_upcall_data = NULL;
677         complete_request_key(cons, ret);
678 }
679
680 static void
681 nfs_idmap_abort_pipe_upcall(struct idmap *idmap, int ret)
682 {
683         if (idmap->idmap_upcall_data != NULL)
684                 nfs_idmap_complete_pipe_upcall_locked(idmap, ret);
685 }
686
687 static int nfs_idmap_legacy_upcall(struct key_construction *cons,
688                                    const char *op,
689                                    void *aux)
690 {
691         struct idmap_legacy_upcalldata *data;
692         struct rpc_pipe_msg *msg;
693         struct idmap_msg *im;
694         struct idmap *idmap = (struct idmap *)aux;
695         struct key *key = cons->key;
696         int ret = -ENOMEM;
697
698         /* msg and im are freed in idmap_pipe_destroy_msg */
699         data = kzalloc(sizeof(*data), GFP_KERNEL);
700         if (!data)
701                 goto out1;
702
703         msg = &data->pipe_msg;
704         im = &data->idmap_msg;
705         data->idmap = idmap;
706         data->key_cons = cons;
707
708         ret = nfs_idmap_prepare_message(key->description, idmap, im, msg);
709         if (ret < 0)
710                 goto out2;
711
712         ret = -EAGAIN;
713         if (!nfs_idmap_prepare_pipe_upcall(idmap, data))
714                 goto out2;
715
716         ret = rpc_queue_upcall(idmap->idmap_pipe, msg);
717         if (ret < 0)
718                 nfs_idmap_abort_pipe_upcall(idmap, ret);
719
720         return ret;
721 out2:
722         kfree(data);
723 out1:
724         complete_request_key(cons, ret);
725         return ret;
726 }
727
728 static int nfs_idmap_instantiate(struct key *key, struct key *authkey, char *data)
729 {
730         return key_instantiate_and_link(key, data, strlen(data) + 1,
731                                         id_resolver_cache->thread_keyring,
732                                         authkey);
733 }
734
735 static int nfs_idmap_read_and_verify_message(struct idmap_msg *im,
736                 struct idmap_msg *upcall,
737                 struct key *key, struct key *authkey)
738 {
739         char id_str[NFS_UINT_MAXLEN];
740         int ret = -ENOKEY;
741
742         /* ret = -ENOKEY */
743         if (upcall->im_type != im->im_type || upcall->im_conv != im->im_conv)
744                 goto out;
745         switch (im->im_conv) {
746         case IDMAP_CONV_NAMETOID:
747                 if (strcmp(upcall->im_name, im->im_name) != 0)
748                         break;
749                 sprintf(id_str, "%d", im->im_id);
750                 ret = nfs_idmap_instantiate(key, authkey, id_str);
751                 break;
752         case IDMAP_CONV_IDTONAME:
753                 if (upcall->im_id != im->im_id)
754                         break;
755                 ret = nfs_idmap_instantiate(key, authkey, im->im_name);
756                 break;
757         default:
758                 ret = -EINVAL;
759         }
760 out:
761         return ret;
762 }
763
764 static ssize_t
765 idmap_pipe_downcall(struct file *filp, const char __user *src, size_t mlen)
766 {
767         struct rpc_inode *rpci = RPC_I(filp->f_path.dentry->d_inode);
768         struct idmap *idmap = (struct idmap *)rpci->private;
769         struct key_construction *cons;
770         struct idmap_msg im;
771         size_t namelen_in;
772         int ret = -ENOKEY;
773
774         /* If instantiation is successful, anyone waiting for key construction
775          * will have been woken up and someone else may now have used
776          * idmap_key_cons - so after this point we may no longer touch it.
777          */
778         if (idmap->idmap_upcall_data == NULL)
779                 goto out_noupcall;
780
781         cons = idmap->idmap_upcall_data->key_cons;
782
783         if (mlen != sizeof(im)) {
784                 ret = -ENOSPC;
785                 goto out;
786         }
787
788         if (copy_from_user(&im, src, mlen) != 0) {
789                 ret = -EFAULT;
790                 goto out;
791         }
792
793         if (!(im.im_status & IDMAP_STATUS_SUCCESS)) {
794                 ret = -ENOKEY;
795                 goto out;
796         }
797
798         namelen_in = strnlen(im.im_name, IDMAP_NAMESZ);
799         if (namelen_in == 0 || namelen_in == IDMAP_NAMESZ) {
800                 ret = -EINVAL;
801                 goto out;
802 }
803
804         ret = nfs_idmap_read_and_verify_message(&im,
805                         &idmap->idmap_upcall_data->idmap_msg,
806                         cons->key, cons->authkey);
807         if (ret >= 0) {
808                 key_set_timeout(cons->key, nfs_idmap_cache_timeout);
809                 ret = mlen;
810         }
811
812 out:
813         nfs_idmap_complete_pipe_upcall_locked(idmap, ret);
814 out_noupcall:
815         return ret;
816 }
817
818 static void
819 idmap_pipe_destroy_msg(struct rpc_pipe_msg *msg)
820 {
821         struct idmap_legacy_upcalldata *data = container_of(msg,
822                         struct idmap_legacy_upcalldata,
823                         pipe_msg);
824         struct idmap *idmap = data->idmap;
825
826         if (msg->errno)
827                 nfs_idmap_abort_pipe_upcall(idmap, msg->errno);
828 }
829
830 static void
831 idmap_release_pipe(struct inode *inode)
832 {
833         struct rpc_inode *rpci = RPC_I(inode);
834         struct idmap *idmap = (struct idmap *)rpci->private;
835
836         nfs_idmap_abort_pipe_upcall(idmap, -EPIPE);
837 }
838
839 int nfs_map_name_to_uid(const struct nfs_server *server, const char *name, size_t namelen, __u32 *uid)
840 {
841         struct idmap *idmap = server->nfs_client->cl_idmap;
842
843         if (nfs_map_string_to_numeric(name, namelen, uid))
844                 return 0;
845         return nfs_idmap_lookup_id(name, namelen, "uid", uid, idmap);
846 }
847
848 int nfs_map_group_to_gid(const struct nfs_server *server, const char *name, size_t namelen, __u32 *gid)
849 {
850         struct idmap *idmap = server->nfs_client->cl_idmap;
851
852         if (nfs_map_string_to_numeric(name, namelen, gid))
853                 return 0;
854         return nfs_idmap_lookup_id(name, namelen, "gid", gid, idmap);
855 }
856
857 int nfs_map_uid_to_name(const struct nfs_server *server, __u32 uid, char *buf, size_t buflen)
858 {
859         struct idmap *idmap = server->nfs_client->cl_idmap;
860         int ret = -EINVAL;
861
862         if (!(server->caps & NFS_CAP_UIDGID_NOMAP))
863                 ret = nfs_idmap_lookup_name(uid, "user", buf, buflen, idmap);
864         if (ret < 0)
865                 ret = nfs_map_numeric_to_string(uid, buf, buflen);
866         return ret;
867 }
868 int nfs_map_gid_to_group(const struct nfs_server *server, __u32 gid, char *buf, size_t buflen)
869 {
870         struct idmap *idmap = server->nfs_client->cl_idmap;
871         int ret = -EINVAL;
872
873         if (!(server->caps & NFS_CAP_UIDGID_NOMAP))
874                 ret = nfs_idmap_lookup_name(gid, "group", buf, buflen, idmap);
875         if (ret < 0)
876                 ret = nfs_map_numeric_to_string(gid, buf, buflen);
877         return ret;
878 }