- 根目录:
- fs
- nfs
- idmap.c
/*
* fs/nfs/idmap.c
*
* UID and GID to name mapping for clients.
*
* Copyright (c) 2002 The Regents of the University of Michigan.
* All rights reserved.
*
* Marius Aamodt Eriksen <marius@umich.edu>
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. Neither the name of the University nor the names of its
* contributors may be used to endorse or promote products derived
* from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESS OR IMPLIED
* WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
* MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
* DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
* SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR
* BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
* LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
* NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
* SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
#include <linux/types.h>
#include <linux/parser.h>
#include <linux/fs.h>
#include <linux/nfs_idmap.h>
#include <net/net_namespace.h>
#include <linux/sunrpc/rpc_pipe_fs.h>
#include <linux/nfs_fs.h>
#include <linux/nfs_fs_sb.h>
#include <linux/key.h>
#include <linux/keyctl.h>
#include <linux/key-type.h>
#include <keys/user-type.h>
#include <linux/module.h>
#include "internal.h"
#include "netns.h"
#define NFS_UINT_MAXLEN 11
/* Default cache timeout is 10 minutes */
unsigned int nfs_idmap_cache_timeout = 600;
static const struct cred *id_resolver_cache;
static struct key_type key_type_id_resolver_legacy;
struct idmap {
struct rpc_pipe *idmap_pipe;
struct key_construction *idmap_key_cons;
struct mutex idmap_mutex;
};
struct idmap_legacy_upcalldata {
struct rpc_pipe_msg pipe_msg;
struct idmap_msg idmap_msg;
struct idmap *idmap;
};
/**
* nfs_fattr_init_names - initialise the nfs_fattr owner_name/group_name fields
* @fattr: fully initialised struct nfs_fattr
* @owner_name: owner name string cache
* @group_name: group name string cache
*/
void nfs_fattr_init_names(struct nfs_fattr *fattr,
struct nfs4_string *owner_name,
struct nfs4_string *group_name)
{
fattr->owner_name = owner_name;
fattr->group_name = group_name;
}
static void nfs_fattr_free_owner_name(struct nfs_fattr *fattr)
{
fattr->valid &= ~NFS_ATTR_FATTR_OWNER_NAME;
kfree(fattr->owner_name->data);
}
static void nfs_fattr_free_group_name(struct nfs_fattr *fattr)
{
fattr->valid &= ~NFS_ATTR_FATTR_GROUP_NAME;
kfree(fattr->group_name->data);
}
static bool nfs_fattr_map_owner_name(struct nfs_server *server, struct nfs_fattr *fattr)
{
struct nfs4_string *owner = fattr->owner_name;
__u32 uid;
if (!(fattr->valid & NFS_ATTR_FATTR_OWNER_NAME))
return false;
if (nfs_map_name_to_uid(server, owner->data, owner->len, &uid) == 0) {
fattr->uid = uid;
fattr->valid |= NFS_ATTR_FATTR_OWNER;
}
return true;
}
static bool nfs_fattr_map_group_name(struct nfs_server *server, struct nfs_fattr *fattr)
{
struct nfs4_string *group = fattr->group_name;
__u32 gid;
if (!(fattr->valid & NFS_ATTR_FATTR_GROUP_NAME))
return false;
if (nfs_map_group_to_gid(server, group->data, group->len, &gid) == 0) {
fattr->gid = gid;
fattr->valid |= NFS_ATTR_FATTR_GROUP;
}
return true;
}
/**
* nfs_fattr_free_names - free up the NFSv4 owner and group strings
* @fattr: a fully initialised nfs_fattr structure
*/
void nfs_fattr_free_names(struct nfs_fattr *fattr)
{
if (fattr->valid & NFS_ATTR_FATTR_OWNER_NAME)
nfs_fattr_free_owner_name(fattr);
if (fattr->valid & NFS_ATTR_FATTR_GROUP_NAME)
nfs_fattr_free_group_name(fattr);
}
/**
* nfs_fattr_map_and_free_names - map owner/group strings into uid/gid and free
* @server: pointer to the filesystem nfs_server structure
* @fattr: a fully initialised nfs_fattr structure
*
* This helper maps the cached NFSv4 owner/group strings in fattr into
* their numeric uid/gid equivalents, and then frees the cached strings.
*/
void nfs_fattr_map_and_free_names(struct nfs_server *server, struct nfs_fattr *fattr)
{
if (nfs_fattr_map_owner_name(server, fattr))
nfs_fattr_free_owner_name(fattr);
if (nfs_fattr_map_group_name(server, fattr))
nfs_fattr_free_group_name(fattr);
}
static int nfs_map_string_to_numeric(const char *name, size_t namelen, __u32 *res)
{
unsigned long val;
char buf[16];
if (memchr(name, '@', namelen) != NULL || namelen >= sizeof(buf))
return 0;
memcpy(buf, name, namelen);
buf[namelen] = '\0';
if (strict_strtoul(buf, 0, &val) != 0)
return 0;
*res = val;
return 1;
}
static int nfs_map_numeric_to_string(__u32 id, char *buf, size_t buflen)
{
return snprintf(buf, buflen, "%u", id);
}
static struct key_type key_type_id_resolver = {
.name = "id_resolver",
.instantiate = user_instantiate,
.match = user_match,
.revoke = user_revoke,
.destroy = user_destroy,
.describe = user_describe,
.read = user_read,
};
static int nfs_idmap_init_keyring(void)
{
struct cred *cred;
struct key *keyring;
int ret = 0;
printk(KERN_NOTICE "NFS: Registering the %s key type\n",
key_type_id_resolver.name);
cred = prepare_kernel_cred(NULL);
if (!cred)
return -ENOMEM;
keyring = key_alloc(&key_type_keyring, ".id_resolver", 0, 0, cred,
(KEY_POS_ALL & ~KEY_POS_SETATTR) |
KEY_USR_VIEW | KEY_USR_READ,
KEY_ALLOC_NOT_IN_QUOTA);
if (IS_ERR(keyring)) {
ret = PTR_ERR(keyring);
goto failed_put_cred;
}
ret = key_instantiate_and_link(keyring, NULL, 0, NULL, NULL);
if (ret < 0)
goto failed_put_key;
ret = register_key_type(&key_type_id_resolver);
if (ret < 0)
goto failed_put_key;
ret = register_key_type(&key_type_id_resolver_legacy);
if (ret < 0)
goto failed_reg_legacy;
set_bit(KEY_FLAG_ROOT_CAN_CLEAR, &keyring->flags);
cred->thread_keyring = keyring;
cred->jit_keyring = KEY_REQKEY_DEFL_THREAD_KEYRING;
id_resolver_cache = cred;
return 0;
failed_reg_legacy:
unregister_key_type(&key_type_id_resolver);
failed_put_key:
key_put(keyring);
failed_put_cred:
put_cred(cred);
return ret;
}
static void nfs_idmap_quit_keyring(void)
{
key_revoke(id_resolver_cache->thread_keyring);
unregister_key_type(&key_type_id_resolver);
unregister_key_type(&key_type_id_resolver_legacy);
put_cred(id_resolver_cache);
}
/*
* Assemble the description to pass to request_key()
* This function will allocate a new string and update dest to point
* at it. The caller is responsible for freeing dest.
*
* On error 0 is returned. Otherwise, the length of dest is returned.
*/
static ssize_t nfs_idmap_get_desc(const char *name, size_t namelen,
const char *type, size_t typelen, char **desc)
{
char *cp;
size_t desclen = typelen + namelen + 2;
*desc = kmalloc(desclen, GFP_KERNEL);
if (!*desc)
return -ENOMEM;
cp = *desc;
memcpy(cp, type, typelen);
cp += typelen;
*cp++ = ':';
memcpy(cp, name, namelen);
cp += namelen;
*cp = '\0';
return desclen;
}
static ssize_t nfs_idmap_request_key(struct key_type *key_type,
const char *name, size_t namelen,
const char *type, void *data,
size_t data_size, struct idmap *idmap)
{
const struct cred *saved_cred;
struct key *rkey;
char *desc;
struct user_key_payload *payload;
ssize_t ret;
ret = nfs_idmap_get_desc(name, namelen, type, strlen(type), &desc);
if (ret <= 0)
goto out;
saved_cred = override_creds(id_resolver_cache);
if (idmap)
rkey = request_key_with_auxdata(key_type, desc, "", 0, idmap);
else
rkey = request_key(&key_type_id_resolver, desc, "");
revert_creds(saved_cred);
kfree(desc);
if (IS_ERR(rkey)) {
ret = PTR_ERR(rkey);
goto out;
}
rcu_read_lock();
rkey->perm |= KEY_USR_VIEW;
ret = key_validate(rkey);
if (ret < 0)
goto out_up;
payload = rcu_dereference(rkey->payload.data);
if (IS_ERR_OR_NULL(payload)) {
ret = PTR_ERR(payload);
goto out_up;
}
ret = payload->datalen;
if (ret > 0 && ret <= data_size)
memcpy(data, payload->data, ret);
else
ret = -EINVAL;
out_up:
rcu_read_unlock();
key_put(rkey);
out:
return ret;
}
static ssize_t nfs_idmap_get_key(const char *name, size_t namelen,
const char *type, void *data,
size_t data_size, struct idmap *idmap)
{
ssize_t ret = nfs_idmap_request_key(&key_type_id_resolver,
name, namelen, type, data,
data_size, NULL);
if (ret < 0) {
mutex_lock(&idmap->idmap_mutex);
ret = nfs_idmap_request_key(&key_type_id_resolver_legacy,
name, namelen, type, data,
data_size, idmap);
idmap->idmap_key_cons = NULL;
mutex_unlock(&idmap->idmap_mutex);
}
return ret;
}
/* ID -> Name */
static ssize_t nfs_idmap_lookup_name(__u32 id, const char *type, char *buf,
size_t buflen, struct idmap *idmap)
{
char id_str[NFS_UINT_MAXLEN];
int id_len;
ssize_t ret;
id_len = snprintf(id_str, sizeof(id_str), "%u", id);
ret = nfs_idmap_get_key(id_str, id_len, type, buf, buflen, idmap);
if (ret < 0)
return -EINVAL;
return ret;
}
/* Name -> ID */
static int nfs_idmap_lookup_id(const char *name, size_t namelen, const char *type,
__u32 *id, struct idmap *idmap)
{
char id_str[NFS_UINT_MAXLEN];
long id_long;
ssize_t data_size;
int ret = 0;
data_size = nfs_idmap_get_key(name, namelen, type, id_str, NFS_UINT_MAXLEN, idmap);
if (data_size <= 0) {
ret = -EINVAL;
} else {
ret = strict_strtol(id_str, 10, &id_long);
*id = (__u32)id_long;
}
return ret;
}
/* idmap classic begins here */
module_param(nfs_idmap_cache_timeout, int, 0644);
enum {
Opt_find_uid, Opt_find_gid, Opt_find_user, Opt_find_group, Opt_find_err
};
static const match_table_t nfs_idmap_tokens = {
{ Opt_find_uid, "uid:%s" },
{ Opt_find_gid, "gid:%s" },
{ Opt_find_user, "user:%s" },
{ Opt_find_group, "group:%s" },
{ Opt_find_err, NULL }
};
static int nfs_idmap_legacy_upcall(struct key_construction *, const char *, void *);
static ssize_t idmap_pipe_downcall(struct file *, const char __user *,
size_t);
static void idmap_release_pipe(struct inode *);
static void idmap_pipe_destroy_msg(struct rpc_pipe_msg *);
static const struct rpc_pipe_ops idmap_upcall_ops = {
.upcall = rpc_pipe_generic_upcall,
.downcall = idmap_pipe_downcall,
.release_pipe = idmap_release_pipe,
.destroy_msg = idmap_pipe_destroy_msg,
};
static struct key_type key_type_id_resolver_legacy = {
.name = "id_legacy",
.instantiate = user_instantiate,
.match = user_match,
.revoke = user_revoke,
.destroy = user_destroy,
.describe = user_describe,
.read = user_read,
.request_key = nfs_idmap_legacy_upcall,
};
static void __nfs_idmap_unregister(struct rpc_pipe *pipe)
{
if (pipe->dentry)
rpc_unlink(pipe->dentry);
}
static int __nfs_idmap_register(struct dentry *dir,
struct idmap *idmap,
struct rpc_pipe *pipe)
{
struct dentry *dentry;
dentry = rpc_mkpipe_dentry(dir, "idmap", idmap, pipe);
if (IS_ERR(dentry))
return PTR_ERR(dentry);
pipe->dentry = dentry;
return 0;
}
static void nfs_idmap_unregister(struct nfs_client *clp,
struct rpc_pipe *pipe)
{
struct net *net = clp->net;
struct super_block *pipefs_sb;
pipefs_sb = rpc_get_sb_net(net);
if (pipefs_sb) {
__nfs_idmap_unregister(pipe);
rpc_put_sb_net(net);
}
}
static int nfs_idmap_register(struct nfs_client *clp,
struct idmap *idmap,
struct rpc_pipe *pipe)
{
struct net *net = clp->net;
struct super_block *pipefs_sb;
int err = 0;
pipefs_sb = rpc_get_sb_net(net);
if (pipefs_sb) {
if (clp->cl_rpcclient->cl_dentry)
err = __nfs_idmap_register(clp->cl_rpcclient->cl_dentry,
idmap, pipe);
rpc_put_sb_net(net);
}
return err;
}
int
nfs_idmap_new(struct nfs_client *clp)
{
struct idmap *idmap;
struct rpc_pipe *pipe;
int error;
BUG_ON(clp->cl_idmap != NULL);
idmap = kzalloc(sizeof(*idmap), GFP_KERNEL);
if (idmap == NULL)
return -ENOMEM;
pipe = rpc_mkpipe_data(&idmap_upcall_ops, 0);
if (IS_ERR(pipe)) {
error = PTR_ERR(pipe);
kfree(idmap);
return error;
}
error = nfs_idmap_register(clp, idmap, pipe);
if (error) {
rpc_destroy_pipe_data(pipe);
kfree(idmap);
return error;
}
idmap->idmap_pipe = pipe;
mutex_init(&idmap->idmap_mutex);
clp->cl_idmap = idmap;
return 0;
}
void
nfs_idmap_delete(struct nfs_client *clp)
{
struct idmap *idmap = clp->cl_idmap;
if (!idmap)
return;
nfs_idmap_unregister(clp, idmap->idmap_pipe);
rpc_destroy_pipe_data(idmap->idmap_pipe);
clp->cl_idmap = NULL;
kfree(idmap);
}
static int __rpc_pipefs_event(struct nfs_client *clp, unsigned long event,
struct super_block *sb)
{
int err = 0;
switch (event) {
case RPC_PIPEFS_MOUNT:
BUG_ON(clp->cl_rpcclient->cl_dentry == NULL);
err = __nfs_idmap_register(clp->cl_rpcclient->cl_dentry,
clp->cl_idmap,
clp->cl_idmap->idmap_pipe);
break;
case RPC_PIPEFS_UMOUNT:
if (clp->cl_idmap->idmap_pipe) {
struct dentry *parent;
parent = clp->cl_idmap->idmap_pipe->dentry->d_parent;
__nfs_idmap_unregister(clp->cl_idmap->idmap_pipe);
/*
* Note: This is a dirty hack. SUNRPC hook has been
* called already but simple_rmdir() call for the
* directory returned with error because of idmap pipe
* inside. Thus now we have to remove this directory
* here.
*/
if (rpc_rmdir(parent))
printk(KERN_ERR "NFS: %s: failed to remove "
"clnt dir!\n", __func__);
}
break;
default:
printk(KERN_ERR "NFS: %s: unknown event: %ld\n", __func__,
event);
return -ENOTSUPP;
}
return err;
}
static struct nfs_client *nfs_get_client_for_event(struct net *net, int event)
{
struct nfs_net *nn = net_generic(net, nfs_net_id);
struct dentry *cl_dentry;
struct nfs_client *clp;
spin_lock(&nn->nfs_client_lock);
list_for_each_entry(clp, &nn->nfs_client_list, cl_share_link) {
if (clp->rpc_ops != &nfs_v4_clientops)
continue;
cl_dentry = clp->cl_idmap->idmap_pipe->dentry;
if (((event == RPC_PIPEFS_MOUNT) && cl_dentry) ||
((event == RPC_PIPEFS_UMOUNT) && !cl_dentry))
continue;
atomic_inc(&clp->cl_count);
spin_unlock(&nn->nfs_client_lock);
return clp;
}
spin_unlock(&nn->nfs_client_lock);
return NULL;
}
static int rpc_pipefs_event(struct notifier_block *nb, unsigned long event,
void *ptr)
{
struct super_block *sb = ptr;
struct nfs_client *clp;
int error = 0;
if (!try_module_get(THIS_MODULE))
return 0;
while ((clp = nfs_get_client_for_event(sb->s_fs_info, event))) {
error = __rpc_pipefs_event(clp, event, sb);
nfs_put_client(clp);
if (error)
break;
}
module_put(THIS_MODULE);
return error;
}
#define PIPEFS_NFS_PRIO 1
static struct notifier_block nfs_idmap_block = {
.notifier_call = rpc_pipefs_event,
.priority = SUNRPC_PIPEFS_NFS_PRIO,
};
int nfs_idmap_init(void)
{
int ret;
ret = nfs_idmap_init_keyring();
if (ret != 0)
goto out;
ret = rpc_pipefs_notifier_register(&nfs_idmap_block);
if (ret != 0)
nfs_idmap_quit_keyring();
out:
return ret;
}
void nfs_idmap_quit(void)
{
rpc_pipefs_notifier_unregister(&nfs_idmap_block);
nfs_idmap_quit_keyring();
}
static int nfs_idmap_prepare_message(char *desc, struct idmap *idmap,
struct idmap_msg *im,
struct rpc_pipe_msg *msg)
{
substring_t substr;
int token, ret;
memset(im, 0, sizeof(*im));
memset(msg, 0, sizeof(*msg));
im->im_type = IDMAP_TYPE_GROUP;
token = match_token(desc, nfs_idmap_tokens, &substr);
switch (token) {
case Opt_find_uid:
im->im_type = IDMAP_TYPE_USER;
case Opt_find_gid:
im->im_conv = IDMAP_CONV_NAMETOID;
ret = match_strlcpy(im->im_name, &substr, IDMAP_NAMESZ);
break;
case Opt_find_user:
im->im_type = IDMAP_TYPE_USER;
case Opt_find_group:
im->im_conv = IDMAP_CONV_IDTONAME;
ret = match_int(&substr, &im->im_id);
break;
default:
ret = -EINVAL;
goto out;
}
msg->data = im;
msg->len = sizeof(struct idmap_msg);
out:
return ret;
}
static int nfs_idmap_legacy_upcall(struct key_construction *cons,
const char *op,
void *aux)
{
struct idmap_legacy_upcalldata *data;
struct rpc_pipe_msg *msg;
struct idmap_msg *im;
struct idmap *idmap = (struct idmap *)aux;
struct key *key = cons->key;
int ret = -ENOMEM;
/* msg and im are freed in idmap_pipe_destroy_msg */
data = kmalloc(sizeof(*data), GFP_KERNEL);
if (!data)
goto out1;
msg = &data->pipe_msg;
im = &data->idmap_msg;
data->idmap = idmap;
ret = nfs_idmap_prepare_message(key->description, idmap, im, msg);
if (ret < 0)
goto out2;
BUG_ON(idmap->idmap_key_cons != NULL);
idmap->idmap_key_cons = cons;
ret = rpc_queue_upcall(idmap->idmap_pipe, msg);
if (ret < 0)
goto out3;
return ret;
out3:
idmap->idmap_key_cons = NULL;
out2:
kfree(data);
out1:
complete_request_key(cons, ret);
return ret;
}
static int nfs_idmap_instantiate(struct key *key, struct key *authkey, char *data)
{
return key_instantiate_and_link(key, data, strlen(data) + 1,
id_resolver_cache->thread_keyring,
authkey);
}
static int nfs_idmap_read_message(struct idmap_msg *im, struct key *key, struct key *authkey)
{
char id_str[NFS_UINT_MAXLEN];
int ret = -EINVAL;
switch (im->im_conv) {
case IDMAP_CONV_NAMETOID:
sprintf(id_str, "%d", im->im_id);
ret = nfs_idmap_instantiate(key, authkey, id_str);
break;
case IDMAP_CONV_IDTONAME:
ret = nfs_idmap_instantiate(key, authkey, im->im_name);
break;
}
return ret;
}
static ssize_t
idmap_pipe_downcall(struct file *filp, const char __user *src, size_t mlen)
{
struct rpc_inode *rpci = RPC_I(filp->f_path.dentry->d_inode);
struct idmap *idmap = (struct idmap *)rpci->private;
struct key_construction *cons;
struct idmap_msg im;
size_t namelen_in;
int ret;
/* If instantiation is successful, anyone waiting for key construction
* will have been woken up and someone else may now have used
* idmap_key_cons - so after this point we may no longer touch it.
*/
cons = ACCESS_ONCE(idmap->idmap_key_cons);
idmap->idmap_key_cons = NULL;
if (mlen != sizeof(im)) {
ret = -ENOSPC;
goto out;
}
if (copy_from_user(&im, src, mlen) != 0) {
ret = -EFAULT;
goto out;
}
if (!(im.im_status & IDMAP_STATUS_SUCCESS)) {
ret = -ENOKEY;
goto out;
}
namelen_in = strnlen(im.im_name, IDMAP_NAMESZ);
if (namelen_in == 0 || namelen_in == IDMAP_NAMESZ) {
ret = -EINVAL;
goto out;
}
ret = nfs_idmap_read_message(&im, cons->key, cons->authkey);
if (ret >= 0) {
key_set_timeout(cons->key, nfs_idmap_cache_timeout);
ret = mlen;
}
out:
complete_request_key(cons, ret);
return ret;
}
static void
idmap_pipe_destroy_msg(struct rpc_pipe_msg *msg)
{
struct idmap_legacy_upcalldata *data = container_of(msg,
struct idmap_legacy_upcalldata,
pipe_msg);
struct idmap *idmap = data->idmap;
struct key_construction *cons;
if (msg->errno) {
cons = ACCESS_ONCE(idmap->idmap_key_cons);
idmap->idmap_key_cons = NULL;
complete_request_key(cons, msg->errno);
}
/* Free memory allocated in nfs_idmap_legacy_upcall() */
kfree(data);
}
static void
idmap_release_pipe(struct inode *inode)
{
struct rpc_inode *rpci = RPC_I(inode);
struct idmap *idmap = (struct idmap *)rpci->private;
idmap->idmap_key_cons = NULL;
}
int nfs_map_name_to_uid(const struct nfs_server *server, const char *name, size_t namelen, __u32 *uid)
{
struct idmap *idmap = server->nfs_client->cl_idmap;
if (nfs_map_string_to_numeric(name, namelen, uid))
return 0;
return nfs_idmap_lookup_id(name, namelen, "uid", uid, idmap);
}
int nfs_map_group_to_gid(const struct nfs_server *server, const char *name, size_t namelen, __u32 *gid)
{
struct idmap *idmap = server->nfs_client->cl_idmap;
if (nfs_map_string_to_numeric(name, namelen, gid))
return 0;
return nfs_idmap_lookup_id(name, namelen, "gid", gid, idmap);
}
int nfs_map_uid_to_name(const struct nfs_server *server, __u32 uid, char *buf, size_t buflen)
{
struct idmap *idmap = server->nfs_client->cl_idmap;
int ret = -EINVAL;
if (!(server->caps & NFS_CAP_UIDGID_NOMAP))
ret = nfs_idmap_lookup_name(uid, "user", buf, buflen, idmap);
if (ret < 0)
ret = nfs_map_numeric_to_string(uid, buf, buflen);
return ret;
}
int nfs_map_gid_to_group(const struct nfs_server *server, __u32 gid, char *buf, size_t buflen)
{
struct idmap *idmap = server->nfs_client->cl_idmap;
int ret = -EINVAL;
if (!(server->caps & NFS_CAP_UIDGID_NOMAP))
ret = nfs_idmap_lookup_name(gid, "group", buf, buflen, idmap);
if (ret < 0)
ret = nfs_map_numeric_to_string(gid, buf, buflen);
return ret;
}