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