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
idmap_userns(const struct idmap * idmap)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 */
nfs_fattr_init_names(struct nfs_fattr * fattr,struct nfs4_string * owner_name,struct nfs4_string * group_name)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
nfs_fattr_free_owner_name(struct nfs_fattr * fattr)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
nfs_fattr_free_group_name(struct nfs_fattr * fattr)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
nfs_fattr_map_owner_name(struct nfs_server * server,struct nfs_fattr * fattr)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
nfs_fattr_map_group_name(struct nfs_server * server,struct nfs_fattr * fattr)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 */
nfs_fattr_free_names(struct nfs_fattr * fattr)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 */
nfs_fattr_map_and_free_names(struct nfs_server * server,struct nfs_fattr * fattr)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
nfs_map_string_to_numeric(const char * name,size_t namelen,__u32 * res)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
nfs_map_numeric_to_string(__u32 id,char * buf,size_t buflen)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
nfs_idmap_init(void)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
nfs_idmap_quit(void)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 */
nfs_idmap_get_desc(const char * name,size_t namelen,const char * type,size_t typelen,char ** desc)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
nfs_idmap_request_key(const char * name,size_t namelen,const char * type,struct idmap * idmap)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
nfs_idmap_get_key(const char * name,size_t namelen,const char * type,void * data,size_t data_size,struct idmap * idmap)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 */
nfs_idmap_lookup_name(__u32 id,const char * type,char * buf,size_t buflen,struct idmap * idmap)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 */
nfs_idmap_lookup_id(const char * name,size_t namelen,const char * type,__u32 * id,struct idmap * idmap)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
nfs_idmap_pipe_destroy(struct dentry * dir,struct rpc_pipe_dir_object * pdo)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
nfs_idmap_pipe_create(struct dentry * dir,struct rpc_pipe_dir_object * pdo)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
nfs_idmap_new(struct nfs_client * clp)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
nfs_idmap_delete(struct nfs_client * clp)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
nfs_idmap_prepare_message(char * desc,struct idmap * idmap,struct idmap_msg * im,struct rpc_pipe_msg * msg)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
nfs_idmap_prepare_pipe_upcall(struct idmap * idmap,struct idmap_legacy_upcalldata * data)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
nfs_idmap_complete_pipe_upcall(struct idmap_legacy_upcalldata * data,int ret)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
nfs_idmap_abort_pipe_upcall(struct idmap * idmap,struct idmap_legacy_upcalldata * data,int ret)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
nfs_idmap_legacy_upcall(struct key * authkey,void * aux)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 = (struct 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
nfs_idmap_instantiate(struct key * key,struct key * authkey,char * data,size_t datalen)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
nfs_idmap_read_and_verify_message(struct idmap_msg * im,struct idmap_msg * upcall,struct key * key,struct key * authkey)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
idmap_pipe_downcall(struct file * filp,const char __user * src,size_t mlen)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
idmap_pipe_destroy_msg(struct rpc_pipe_msg * msg)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
idmap_release_pipe(struct inode * inode)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
nfs_map_name_to_uid(const struct nfs_server * server,const char * name,size_t namelen,kuid_t * uid)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
nfs_map_group_to_gid(const struct nfs_server * server,const char * name,size_t namelen,kgid_t * gid)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
nfs_map_uid_to_name(const struct nfs_server * server,kuid_t uid,char * buf,size_t buflen)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 }
nfs_map_gid_to_group(const struct nfs_server * server,kgid_t gid,char * buf,size_t buflen)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 }
807