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v4.17
  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 <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 * nfs_fattr_init_names - initialise the nfs_fattr owner_name/group_name fields
 75 * @fattr: fully initialised struct nfs_fattr
 76 * @owner_name: owner name string cache
 77 * @group_name: group name string cache
 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 * nfs_fattr_free_names - free up the NFSv4 owner and group strings
129 * @fattr: a fully initialised nfs_fattr structure
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 * nfs_fattr_map_and_free_names - map owner/group strings into uid/gid and free
141 * @server: pointer to the filesystem nfs_server structure
142 * @fattr: a fully initialised nfs_fattr structure
143 *
144 * This helper maps the cached NFSv4 owner/group strings in fattr into
145 * their numeric uid/gid equivalents, and then frees the cached strings.
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 * Assemble the description to pass to request_key()
243 * This function will allocate a new string and update dest to point
244 * at it.  The caller is responsible for freeing dest.
245 *
246 * On error 0 is returned.  Otherwise, the length of dest is returned.
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/* ID -> Name */
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/* Name -> ID */
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/* idmap classic begins here */
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 = -ENOKEY;
572
573	if (!aux)
574		goto out1;
575
576	/* msg and im are freed in idmap_pipe_destroy_msg */
577	ret = -ENOMEM;
578	data = kzalloc(sizeof(*data), GFP_KERNEL);
579	if (!data)
580		goto out1;
581
582	msg = &data->pipe_msg;
583	im = &data->idmap_msg;
584	data->idmap = idmap;
585	data->key_cons = cons;
586
587	ret = nfs_idmap_prepare_message(key->description, idmap, im, msg);
588	if (ret < 0)
589		goto out2;
590
591	ret = -EAGAIN;
592	if (!nfs_idmap_prepare_pipe_upcall(idmap, data))
593		goto out2;
594
595	ret = rpc_queue_upcall(idmap->idmap_pipe, msg);
596	if (ret < 0)
597		nfs_idmap_abort_pipe_upcall(idmap, ret);
598
599	return ret;
600out2:
601	kfree(data);
602out1:
603	complete_request_key(cons, ret);
604	return ret;
605}
606
607static int nfs_idmap_instantiate(struct key *key, struct key *authkey, char *data, size_t datalen)
608{
609	return key_instantiate_and_link(key, data, datalen,
610					id_resolver_cache->thread_keyring,
611					authkey);
612}
613
614static int nfs_idmap_read_and_verify_message(struct idmap_msg *im,
615		struct idmap_msg *upcall,
616		struct key *key, struct key *authkey)
617{
618	char id_str[NFS_UINT_MAXLEN];
619	size_t len;
620	int ret = -ENOKEY;
621
622	/* ret = -ENOKEY */
623	if (upcall->im_type != im->im_type || upcall->im_conv != im->im_conv)
624		goto out;
625	switch (im->im_conv) {
626	case IDMAP_CONV_NAMETOID:
627		if (strcmp(upcall->im_name, im->im_name) != 0)
628			break;
629		/* Note: here we store the NUL terminator too */
630		len = sprintf(id_str, "%d", im->im_id) + 1;
 
631		ret = nfs_idmap_instantiate(key, authkey, id_str, len);
632		break;
633	case IDMAP_CONV_IDTONAME:
634		if (upcall->im_id != im->im_id)
635			break;
636		len = strlen(im->im_name);
637		ret = nfs_idmap_instantiate(key, authkey, im->im_name, len);
638		break;
639	default:
640		ret = -EINVAL;
641	}
642out:
643	return ret;
644}
645
646static ssize_t
647idmap_pipe_downcall(struct file *filp, const char __user *src, size_t mlen)
648{
 
649	struct rpc_inode *rpci = RPC_I(file_inode(filp));
650	struct idmap *idmap = (struct idmap *)rpci->private;
651	struct key_construction *cons;
 
652	struct idmap_msg im;
653	size_t namelen_in;
654	int ret = -ENOKEY;
655
656	/* If instantiation is successful, anyone waiting for key construction
657	 * will have been woken up and someone else may now have used
658	 * idmap_key_cons - so after this point we may no longer touch it.
659	 */
660	if (idmap->idmap_upcall_data == NULL)
 
661		goto out_noupcall;
662
663	cons = idmap->idmap_upcall_data->key_cons;
 
664
665	if (mlen != sizeof(im)) {
666		ret = -ENOSPC;
667		goto out;
668	}
669
670	if (copy_from_user(&im, src, mlen) != 0) {
671		ret = -EFAULT;
672		goto out;
673	}
674
675	if (!(im.im_status & IDMAP_STATUS_SUCCESS)) {
676		ret = -ENOKEY;
677		goto out;
678	}
679
680	namelen_in = strnlen(im.im_name, IDMAP_NAMESZ);
681	if (namelen_in == 0 || namelen_in == IDMAP_NAMESZ) {
682		ret = -EINVAL;
683		goto out;
684}
685
686	ret = nfs_idmap_read_and_verify_message(&im,
687			&idmap->idmap_upcall_data->idmap_msg,
688			cons->key, cons->authkey);
689	if (ret >= 0) {
690		key_set_timeout(cons->key, nfs_idmap_cache_timeout);
691		ret = mlen;
692	}
693
694out:
695	nfs_idmap_complete_pipe_upcall_locked(idmap, ret);
696out_noupcall:
697	return ret;
698}
699
700static void
701idmap_pipe_destroy_msg(struct rpc_pipe_msg *msg)
702{
703	struct idmap_legacy_upcalldata *data = container_of(msg,
704			struct idmap_legacy_upcalldata,
705			pipe_msg);
706	struct idmap *idmap = data->idmap;
707
708	if (msg->errno)
709		nfs_idmap_abort_pipe_upcall(idmap, msg->errno);
710}
711
712static void
713idmap_release_pipe(struct inode *inode)
714{
715	struct rpc_inode *rpci = RPC_I(inode);
716	struct idmap *idmap = (struct idmap *)rpci->private;
 
717
718	nfs_idmap_abort_pipe_upcall(idmap, -EPIPE);
 
 
719}
720
721int nfs_map_name_to_uid(const struct nfs_server *server, const char *name, size_t namelen, kuid_t *uid)
722{
723	struct idmap *idmap = server->nfs_client->cl_idmap;
724	__u32 id = -1;
725	int ret = 0;
726
727	if (!nfs_map_string_to_numeric(name, namelen, &id))
728		ret = nfs_idmap_lookup_id(name, namelen, "uid", &id, idmap);
729	if (ret == 0) {
730		*uid = make_kuid(&init_user_ns, id);
731		if (!uid_valid(*uid))
732			ret = -ERANGE;
733	}
734	trace_nfs4_map_name_to_uid(name, namelen, id, ret);
735	return ret;
736}
737
738int nfs_map_group_to_gid(const struct nfs_server *server, const char *name, size_t namelen, kgid_t *gid)
739{
740	struct idmap *idmap = server->nfs_client->cl_idmap;
741	__u32 id = -1;
742	int ret = 0;
743
744	if (!nfs_map_string_to_numeric(name, namelen, &id))
745		ret = nfs_idmap_lookup_id(name, namelen, "gid", &id, idmap);
746	if (ret == 0) {
747		*gid = make_kgid(&init_user_ns, id);
748		if (!gid_valid(*gid))
749			ret = -ERANGE;
750	}
751	trace_nfs4_map_group_to_gid(name, namelen, id, ret);
752	return ret;
753}
754
755int nfs_map_uid_to_name(const struct nfs_server *server, kuid_t uid, char *buf, size_t buflen)
756{
757	struct idmap *idmap = server->nfs_client->cl_idmap;
758	int ret = -EINVAL;
759	__u32 id;
760
761	id = from_kuid(&init_user_ns, uid);
762	if (!(server->caps & NFS_CAP_UIDGID_NOMAP))
763		ret = nfs_idmap_lookup_name(id, "user", buf, buflen, idmap);
764	if (ret < 0)
765		ret = nfs_map_numeric_to_string(id, buf, buflen);
766	trace_nfs4_map_uid_to_name(buf, ret, id, ret);
767	return ret;
768}
769int nfs_map_gid_to_group(const struct nfs_server *server, kgid_t gid, char *buf, size_t buflen)
770{
771	struct idmap *idmap = server->nfs_client->cl_idmap;
772	int ret = -EINVAL;
773	__u32 id;
774
775	id = from_kgid(&init_user_ns, gid);
776	if (!(server->caps & NFS_CAP_UIDGID_NOMAP))
777		ret = nfs_idmap_lookup_name(id, "group", buf, buflen, idmap);
778	if (ret < 0)
779		ret = nfs_map_numeric_to_string(id, buf, buflen);
780	trace_nfs4_map_gid_to_group(buf, ret, id, ret);
781	return ret;
782}
v6.13.7
  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
 58static const struct cred *id_resolver_cache;
 59static struct key_type key_type_id_resolver_legacy;
 60
 61struct 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
 68struct 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
 76static 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 */
 89void 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
 97static 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
103static 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
109static 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
123static 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 */
141void 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 */
157void 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
165int 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}
179EXPORT_SYMBOL_GPL(nfs_map_string_to_numeric);
180
181static int nfs_map_numeric_to_string(__u32 id, char *buf, size_t buflen)
182{
183	return snprintf(buf, buflen, "%u", id);
184}
185
186static 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
197int 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(&init_task);
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
234failed_reg_legacy:
235	unregister_key_type(&key_type_id_resolver);
236failed_put_key:
237	key_put(keyring);
238failed_put_cred:
239	put_cred(cred);
240	return ret;
241}
242
243void 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 */
258static 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
279static 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
305static 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
342out_up:
343	rcu_read_unlock();
344	key_put(rkey);
345out:
346	return ret;
347}
348
349/* ID -> Name */
350static 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 */
365static 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
386enum {
387	Opt_find_uid, Opt_find_gid, Opt_find_user, Opt_find_group, Opt_find_err
388};
389
390static 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
398static int nfs_idmap_legacy_upcall(struct key *, void *);
399static ssize_t idmap_pipe_downcall(struct file *, const char __user *,
400				   size_t);
401static void idmap_release_pipe(struct inode *);
402static void idmap_pipe_destroy_msg(struct rpc_pipe_msg *);
403
404static 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
411static 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
423static 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
435static 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
449static 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
454int
455nfs_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;
487err_destroy_pipe:
488	rpc_destroy_pipe_data(idmap->idmap_pipe);
489err:
490	put_user_ns(idmap->user_ns);
491	kfree(idmap);
492	return error;
493}
494
495void
496nfs_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
511static 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
548out:
549	return ret;
550}
551
552static bool
553nfs_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
564static 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
572static 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
580static 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;
617out2:
618	kfree(data);
619out1:
620	complete_request_key(authkey, ret);
621	return ret;
622}
623
624static 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
631static 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	}
660out:
661	return ret;
662}
663
664static ssize_t
665idmap_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
715out:
716	nfs_idmap_complete_pipe_upcall(data, ret);
717out_noupcall:
718	return ret;
719}
720
721static void
722idmap_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
733static void
734idmap_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
745int 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
762int 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
779int 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}
793int 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}