diff options
Diffstat (limited to 'fs/nfs/nfs4idmap.c')
| -rw-r--r-- | fs/nfs/nfs4idmap.c | 792 |
1 files changed, 792 insertions, 0 deletions
diff --git a/fs/nfs/nfs4idmap.c b/fs/nfs/nfs4idmap.c new file mode 100644 index 000000000000..2e1737c40a29 --- /dev/null +++ b/fs/nfs/nfs4idmap.c @@ -0,0 +1,792 @@ +/* + * 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 <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" +#include "nfs4idmap.h" +#include "nfs4trace.h" + +#define NFS_UINT_MAXLEN 11 + +static const struct cred *id_resolver_cache; +static struct key_type key_type_id_resolver_legacy; + +struct idmap_legacy_upcalldata { + struct rpc_pipe_msg pipe_msg; + struct idmap_msg idmap_msg; + struct key_construction *key_cons; + struct idmap *idmap; +}; + +struct idmap { + struct rpc_pipe_dir_object idmap_pdo; + struct rpc_pipe *idmap_pipe; + struct idmap_legacy_upcalldata *idmap_upcall_data; + struct mutex idmap_mutex; +}; + +/** + * 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; + kuid_t 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; + kgid_t 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); +} + +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 (kstrtoul(buf, 0, &val) != 0) + return 0; + *res = val; + return 1; +} +EXPORT_SYMBOL_GPL(nfs_map_string_to_numeric); + +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", + .preparse = user_preparse, + .free_preparse = user_free_preparse, + .instantiate = generic_key_instantiate, + .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 = keyring_alloc(".id_resolver", + GLOBAL_ROOT_UID, GLOBAL_ROOT_GID, cred, + (KEY_POS_ALL & ~KEY_POS_SETATTR) | + KEY_USR_VIEW | KEY_USR_READ, + KEY_ALLOC_NOT_IN_QUOTA, NULL); + if (IS_ERR(keyring)) { + ret = PTR_ERR(keyring); + goto failed_put_cred; + } + + 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 struct key *nfs_idmap_request_key(const char *name, size_t namelen, + const char *type, struct idmap *idmap) +{ + char *desc; + struct key *rkey; + ssize_t ret; + + ret = nfs_idmap_get_desc(name, namelen, type, strlen(type), &desc); + if (ret <= 0) + return ERR_PTR(ret); + + rkey = request_key(&key_type_id_resolver, desc, ""); + if (IS_ERR(rkey)) { + mutex_lock(&idmap->idmap_mutex); + rkey = request_key_with_auxdata(&key_type_id_resolver_legacy, + desc, "", 0, idmap); + mutex_unlock(&idmap->idmap_mutex); + } + if (!IS_ERR(rkey)) + set_bit(KEY_FLAG_ROOT_CAN_INVAL, &rkey->flags); + + kfree(desc); + return rkey; +} + +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) +{ + const struct cred *saved_cred; + struct key *rkey; + struct user_key_payload *payload; + ssize_t ret; + + saved_cred = override_creds(id_resolver_cache); + rkey = nfs_idmap_request_key(name, namelen, type, idmap); + revert_creds(saved_cred); + + 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.rcudata); + 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; +} + +/* 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 = kstrtol(id_str, 10, &id_long); + *id = (__u32)id_long; + } + return ret; +} + +/* idmap classic begins here */ + +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", + .preparse = user_preparse, + .free_preparse = user_free_preparse, + .instantiate = generic_key_instantiate, + .revoke = user_revoke, + .destroy = user_destroy, + .describe = user_describe, + .read = user_read, + .request_key = nfs_idmap_legacy_upcall, +}; + +static void nfs_idmap_pipe_destroy(struct dentry *dir, + struct rpc_pipe_dir_object *pdo) +{ + struct idmap *idmap = pdo->pdo_data; + struct rpc_pipe *pipe = idmap->idmap_pipe; + + if (pipe->dentry) { + rpc_unlink(pipe->dentry); + pipe->dentry = NULL; + } +} + +static int nfs_idmap_pipe_create(struct dentry *dir, + struct rpc_pipe_dir_object *pdo) +{ + struct idmap *idmap = pdo->pdo_data; + struct rpc_pipe *pipe = idmap->idmap_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 const struct rpc_pipe_dir_object_ops nfs_idmap_pipe_dir_object_ops = { + .create = nfs_idmap_pipe_create, + .destroy = nfs_idmap_pipe_destroy, +}; + +int +nfs_idmap_new(struct nfs_client *clp) +{ + struct idmap *idmap; + struct rpc_pipe *pipe; + int error; + + idmap = kzalloc(sizeof(*idmap), GFP_KERNEL); + if (idmap == NULL) + return -ENOMEM; + + rpc_init_pipe_dir_object(&idmap->idmap_pdo, + &nfs_idmap_pipe_dir_object_ops, + idmap); + + pipe = rpc_mkpipe_data(&idmap_upcall_ops, 0); + if (IS_ERR(pipe)) { + error = PTR_ERR(pipe); + goto err; + } + idmap->idmap_pipe = pipe; + mutex_init(&idmap->idmap_mutex); + + error = rpc_add_pipe_dir_object(clp->cl_net, + &clp->cl_rpcclient->cl_pipedir_objects, + &idmap->idmap_pdo); + if (error) + goto err_destroy_pipe; + + clp->cl_idmap = idmap; + return 0; +err_destroy_pipe: + rpc_destroy_pipe_data(idmap->idmap_pipe); +err: + kfree(idmap); + return error; +} + +void +nfs_idmap_delete(struct nfs_client *clp) +{ + struct idmap *idmap = clp->cl_idmap; + + if (!idmap) + return; + clp->cl_idmap = NULL; + rpc_remove_pipe_dir_object(clp->cl_net, + &clp->cl_rpcclient->cl_pipedir_objects, + &idmap->idmap_pdo); + rpc_destroy_pipe_data(idmap->idmap_pipe); + kfree(idmap); +} + +int nfs_idmap_init(void) +{ + int ret; + ret = nfs_idmap_init_keyring(); + if (ret != 0) + goto out; +out: + return ret; +} + +void nfs_idmap_quit(void) +{ + 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; + + 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 bool +nfs_idmap_prepare_pipe_upcall(struct idmap *idmap, + struct idmap_legacy_upcalldata *data) +{ + if (idmap->idmap_upcall_data != NULL) { + WARN_ON_ONCE(1); + return false; + } + idmap->idmap_upcall_data = data; + return true; +} + +static void +nfs_idmap_complete_pipe_upcall_locked(struct idmap *idmap, int ret) +{ + struct key_construction *cons = idmap->idmap_upcall_data->key_cons; + + kfree(idmap->idmap_upcall_data); + idmap->idmap_upcall_data = NULL; + complete_request_key(cons, ret); +} + +static void +nfs_idmap_abort_pipe_upcall(struct idmap *idmap, int ret) +{ + if (idmap->idmap_upcall_data != NULL) + nfs_idmap_complete_pipe_upcall_locked(idmap, 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 = kzalloc(sizeof(*data), GFP_KERNEL); + if (!data) + goto out1; + + msg = &data->pipe_msg; + im = &data->idmap_msg; + data->idmap = idmap; + data->key_cons = cons; + + ret = nfs_idmap_prepare_message(key->description, idmap, im, msg); + if (ret < 0) + goto out2; + + ret = -EAGAIN; + if (!nfs_idmap_prepare_pipe_upcall(idmap, data)) + goto out2; + + ret = rpc_queue_upcall(idmap->idmap_pipe, msg); + if (ret < 0) + nfs_idmap_abort_pipe_upcall(idmap, ret); + + return ret; +out2: + kfree(data); +out1: + complete_request_key(cons, ret); + return ret; +} + +static int nfs_idmap_instantiate(struct key *key, struct key *authkey, char *data, size_t datalen) +{ + return key_instantiate_and_link(key, data, datalen, + id_resolver_cache->thread_keyring, + authkey); +} + +static int nfs_idmap_read_and_verify_message(struct idmap_msg *im, + struct idmap_msg *upcall, + struct key *key, struct key *authkey) +{ + char id_str[NFS_UINT_MAXLEN]; + size_t len; + int ret = -ENOKEY; + + /* ret = -ENOKEY */ + if (upcall->im_type != im->im_type || upcall->im_conv != im->im_conv) + goto out; + switch (im->im_conv) { + case IDMAP_CONV_NAMETOID: + if (strcmp(upcall->im_name, im->im_name) != 0) + break; + /* Note: here we store the NUL terminator too */ + len = sprintf(id_str, "%d", im->im_id) + 1; + ret = nfs_idmap_instantiate(key, authkey, id_str, len); + break; + case IDMAP_CONV_IDTONAME: + if (upcall->im_id != im->im_id) + break; + len = strlen(im->im_name); + ret = nfs_idmap_instantiate(key, authkey, im->im_name, len); + break; + default: + ret = -EINVAL; + } +out: + return ret; +} + +static ssize_t +idmap_pipe_downcall(struct file *filp, const char __user *src, size_t mlen) +{ + struct rpc_inode *rpci = RPC_I(file_inode(filp)); + struct idmap *idmap = (struct idmap *)rpci->private; + struct key_construction *cons; + struct idmap_msg im; + size_t namelen_in; + int ret = -ENOKEY; + + /* 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. + */ + if (idmap->idmap_upcall_data == NULL) + goto out_noupcall; + + cons = idmap->idmap_upcall_data->key_cons; + + 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_and_verify_message(&im, + &idmap->idmap_upcall_data->idmap_msg, + cons->key, cons->authkey); + if (ret >= 0) { + key_set_timeout(cons->key, nfs_idmap_cache_timeout); + ret = mlen; + } + +out: + nfs_idmap_complete_pipe_upcall_locked(idmap, ret); +out_noupcall: + 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; + + if (msg->errno) + nfs_idmap_abort_pipe_upcall(idmap, msg->errno); +} + +static void +idmap_release_pipe(struct inode *inode) +{ + struct rpc_inode *rpci = RPC_I(inode); + struct idmap *idmap = (struct idmap *)rpci->private; + + nfs_idmap_abort_pipe_upcall(idmap, -EPIPE); +} + +int nfs_map_name_to_uid(const struct nfs_server *server, const char *name, size_t namelen, kuid_t *uid) +{ + struct idmap *idmap = server->nfs_client->cl_idmap; + __u32 id = -1; + int ret = 0; + + if (!nfs_map_string_to_numeric(name, namelen, &id)) + ret = nfs_idmap_lookup_id(name, namelen, "uid", &id, idmap); + if (ret == 0) { + *uid = make_kuid(&init_user_ns, id); + if (!uid_valid(*uid)) + ret = -ERANGE; + } + trace_nfs4_map_name_to_uid(name, namelen, id, ret); + return ret; +} + +int nfs_map_group_to_gid(const struct nfs_server *server, const char *name, size_t namelen, kgid_t *gid) +{ + struct idmap *idmap = server->nfs_client->cl_idmap; + __u32 id = -1; + int ret = 0; + + if (!nfs_map_string_to_numeric(name, namelen, &id)) + ret = nfs_idmap_lookup_id(name, namelen, "gid", &id, idmap); + if (ret == 0) { + *gid = make_kgid(&init_user_ns, id); + if (!gid_valid(*gid)) + ret = -ERANGE; + } + trace_nfs4_map_group_to_gid(name, namelen, id, ret); + return ret; +} + +int nfs_map_uid_to_name(const struct nfs_server *server, kuid_t uid, char *buf, size_t buflen) +{ + struct idmap *idmap = server->nfs_client->cl_idmap; + int ret = -EINVAL; + __u32 id; + + id = from_kuid(&init_user_ns, uid); + if (!(server->caps & NFS_CAP_UIDGID_NOMAP)) + ret = nfs_idmap_lookup_name(id, "user", buf, buflen, idmap); + if (ret < 0) + ret = nfs_map_numeric_to_string(id, buf, buflen); + trace_nfs4_map_uid_to_name(buf, ret, id, ret); + return ret; +} +int nfs_map_gid_to_group(const struct nfs_server *server, kgid_t gid, char *buf, size_t buflen) +{ + struct idmap *idmap = server->nfs_client->cl_idmap; + int ret = -EINVAL; + __u32 id; + + id = from_kgid(&init_user_ns, gid); + if (!(server->caps & NFS_CAP_UIDGID_NOMAP)) + ret = nfs_idmap_lookup_name(id, "group", buf, buflen, idmap); + if (ret < 0) + ret = nfs_map_numeric_to_string(id, buf, buflen); + trace_nfs4_map_gid_to_group(buf, ret, id, ret); + return ret; +} |