linux/fs/nfs/idmap.c
Trond Myklebust 6926afd192 NFSv4: Save the owner/group name string when doing open
...so that we can do the uid/gid mapping outside the asynchronous RPC
context.
This fixes a bug in the current NFSv4 atomic open code where the client
isn't able to determine what the true uid/gid fields of the file are,
(because the asynchronous nature of the OPEN call denies it the ability
to do an upcall) and so fills them with default values, marking the
inode as needing revalidation.
Unfortunately, in some cases, the VFS will do some additional sanity
checks on the file, and may override the server's decision to allow
the open because it sees the wrong owner/group fields.

Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2012-01-07 13:22:46 -05:00

836 lines
21 KiB
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/string.h>
#include <linux/kernel.h>
#include <linux/slab.h>
#include <linux/nfs_idmap.h>
#include <linux/nfs_fs.h>
/**
* 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);
}
#ifdef CONFIG_NFS_USE_NEW_IDMAPPER
#include <linux/cred.h>
#include <linux/sunrpc/sched.h>
#include <linux/nfs4.h>
#include <linux/nfs_fs_sb.h>
#include <linux/keyctl.h>
#include <linux/key-type.h>
#include <linux/rcupdate.h>
#include <linux/err.h>
#include <keys/user-type.h>
#define NFS_UINT_MAXLEN 11
const struct cred *id_resolver_cache;
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,
};
int nfs_idmap_init(void)
{
struct cred *cred;
struct key *keyring;
int ret = 0;
printk(KERN_NOTICE "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;
cred->thread_keyring = keyring;
cred->jit_keyring = KEY_REQKEY_DEFL_THREAD_KEYRING;
id_resolver_cache = cred;
return 0;
failed_put_key:
key_put(keyring);
failed_put_cred:
put_cred(cred);
return ret;
}
void nfs_idmap_quit(void)
{
key_revoke(id_resolver_cache->thread_keyring);
unregister_key_type(&key_type_id_resolver);
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(const char *name, size_t namelen,
const char *type, void *data, size_t data_size)
{
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);
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;
}
/* ID -> Name */
static ssize_t nfs_idmap_lookup_name(__u32 id, const char *type, char *buf, size_t buflen)
{
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_request_key(id_str, id_len, type, buf, buflen);
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)
{
char id_str[NFS_UINT_MAXLEN];
long id_long;
ssize_t data_size;
int ret = 0;
data_size = nfs_idmap_request_key(name, namelen, type, id_str, NFS_UINT_MAXLEN);
if (data_size <= 0) {
ret = -EINVAL;
} else {
ret = strict_strtol(id_str, 10, &id_long);
*id = (__u32)id_long;
}
return ret;
}
int nfs_map_name_to_uid(const struct nfs_server *server, const char *name, size_t namelen, __u32 *uid)
{
if (nfs_map_string_to_numeric(name, namelen, uid))
return 0;
return nfs_idmap_lookup_id(name, namelen, "uid", uid);
}
int nfs_map_group_to_gid(const struct nfs_server *server, const char *name, size_t namelen, __u32 *gid)
{
if (nfs_map_string_to_numeric(name, namelen, gid))
return 0;
return nfs_idmap_lookup_id(name, namelen, "gid", gid);
}
int nfs_map_uid_to_name(const struct nfs_server *server, __u32 uid, char *buf, size_t buflen)
{
int ret = -EINVAL;
if (!(server->caps & NFS_CAP_UIDGID_NOMAP))
ret = nfs_idmap_lookup_name(uid, "user", buf, buflen);
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)
{
int ret = -EINVAL;
if (!(server->caps & NFS_CAP_UIDGID_NOMAP))
ret = nfs_idmap_lookup_name(gid, "group", buf, buflen);
if (ret < 0)
ret = nfs_map_numeric_to_string(gid, buf, buflen);
return ret;
}
#else /* CONFIG_NFS_USE_NEW_IDMAPPER not defined */
#include <linux/module.h>
#include <linux/mutex.h>
#include <linux/init.h>
#include <linux/socket.h>
#include <linux/in.h>
#include <linux/sched.h>
#include <linux/sunrpc/clnt.h>
#include <linux/workqueue.h>
#include <linux/sunrpc/rpc_pipe_fs.h>
#include <linux/nfs_fs.h>
#include "nfs4_fs.h"
#define IDMAP_HASH_SZ 128
/* Default cache timeout is 10 minutes */
unsigned int nfs_idmap_cache_timeout = 600 * HZ;
static int param_set_idmap_timeout(const char *val, struct kernel_param *kp)
{
char *endp;
int num = simple_strtol(val, &endp, 0);
int jif = num * HZ;
if (endp == val || *endp || num < 0 || jif < num)
return -EINVAL;
*((int *)kp->arg) = jif;
return 0;
}
module_param_call(idmap_cache_timeout, param_set_idmap_timeout, param_get_int,
&nfs_idmap_cache_timeout, 0644);
struct idmap_hashent {
unsigned long ih_expires;
__u32 ih_id;
size_t ih_namelen;
char ih_name[IDMAP_NAMESZ];
};
struct idmap_hashtable {
__u8 h_type;
struct idmap_hashent h_entries[IDMAP_HASH_SZ];
};
struct idmap {
struct dentry *idmap_dentry;
wait_queue_head_t idmap_wq;
struct idmap_msg idmap_im;
struct mutex idmap_lock; /* Serializes upcalls */
struct mutex idmap_im_lock; /* Protects the hashtable */
struct idmap_hashtable idmap_user_hash;
struct idmap_hashtable idmap_group_hash;
};
static ssize_t idmap_pipe_downcall(struct file *, const char __user *,
size_t);
static void idmap_pipe_destroy_msg(struct rpc_pipe_msg *);
static unsigned int fnvhash32(const void *, size_t);
static const struct rpc_pipe_ops idmap_upcall_ops = {
.upcall = rpc_pipe_generic_upcall,
.downcall = idmap_pipe_downcall,
.destroy_msg = idmap_pipe_destroy_msg,
};
int
nfs_idmap_new(struct nfs_client *clp)
{
struct idmap *idmap;
int error;
BUG_ON(clp->cl_idmap != NULL);
idmap = kzalloc(sizeof(*idmap), GFP_KERNEL);
if (idmap == NULL)
return -ENOMEM;
idmap->idmap_dentry = rpc_mkpipe(clp->cl_rpcclient->cl_path.dentry,
"idmap", idmap, &idmap_upcall_ops, 0);
if (IS_ERR(idmap->idmap_dentry)) {
error = PTR_ERR(idmap->idmap_dentry);
kfree(idmap);
return error;
}
mutex_init(&idmap->idmap_lock);
mutex_init(&idmap->idmap_im_lock);
init_waitqueue_head(&idmap->idmap_wq);
idmap->idmap_user_hash.h_type = IDMAP_TYPE_USER;
idmap->idmap_group_hash.h_type = IDMAP_TYPE_GROUP;
clp->cl_idmap = idmap;
return 0;
}
void
nfs_idmap_delete(struct nfs_client *clp)
{
struct idmap *idmap = clp->cl_idmap;
if (!idmap)
return;
rpc_unlink(idmap->idmap_dentry);
clp->cl_idmap = NULL;
kfree(idmap);
}
/*
* Helper routines for manipulating the hashtable
*/
static inline struct idmap_hashent *
idmap_name_hash(struct idmap_hashtable* h, const char *name, size_t len)
{
return &h->h_entries[fnvhash32(name, len) % IDMAP_HASH_SZ];
}
static struct idmap_hashent *
idmap_lookup_name(struct idmap_hashtable *h, const char *name, size_t len)
{
struct idmap_hashent *he = idmap_name_hash(h, name, len);
if (he->ih_namelen != len || memcmp(he->ih_name, name, len) != 0)
return NULL;
if (time_after(jiffies, he->ih_expires))
return NULL;
return he;
}
static inline struct idmap_hashent *
idmap_id_hash(struct idmap_hashtable* h, __u32 id)
{
return &h->h_entries[fnvhash32(&id, sizeof(id)) % IDMAP_HASH_SZ];
}
static struct idmap_hashent *
idmap_lookup_id(struct idmap_hashtable *h, __u32 id)
{
struct idmap_hashent *he = idmap_id_hash(h, id);
if (he->ih_id != id || he->ih_namelen == 0)
return NULL;
if (time_after(jiffies, he->ih_expires))
return NULL;
return he;
}
/*
* Routines for allocating new entries in the hashtable.
* For now, we just have 1 entry per bucket, so it's all
* pretty trivial.
*/
static inline struct idmap_hashent *
idmap_alloc_name(struct idmap_hashtable *h, char *name, size_t len)
{
return idmap_name_hash(h, name, len);
}
static inline struct idmap_hashent *
idmap_alloc_id(struct idmap_hashtable *h, __u32 id)
{
return idmap_id_hash(h, id);
}
static void
idmap_update_entry(struct idmap_hashent *he, const char *name,
size_t namelen, __u32 id)
{
he->ih_id = id;
memcpy(he->ih_name, name, namelen);
he->ih_name[namelen] = '\0';
he->ih_namelen = namelen;
he->ih_expires = jiffies + nfs_idmap_cache_timeout;
}
/*
* Name -> ID
*/
static int
nfs_idmap_id(struct idmap *idmap, struct idmap_hashtable *h,
const char *name, size_t namelen, __u32 *id)
{
struct rpc_pipe_msg msg;
struct idmap_msg *im;
struct idmap_hashent *he;
DECLARE_WAITQUEUE(wq, current);
int ret = -EIO;
im = &idmap->idmap_im;
/*
* String sanity checks
* Note that the userland daemon expects NUL terminated strings
*/
for (;;) {
if (namelen == 0)
return -EINVAL;
if (name[namelen-1] != '\0')
break;
namelen--;
}
if (namelen >= IDMAP_NAMESZ)
return -EINVAL;
mutex_lock(&idmap->idmap_lock);
mutex_lock(&idmap->idmap_im_lock);
he = idmap_lookup_name(h, name, namelen);
if (he != NULL) {
*id = he->ih_id;
ret = 0;
goto out;
}
memset(im, 0, sizeof(*im));
memcpy(im->im_name, name, namelen);
im->im_type = h->h_type;
im->im_conv = IDMAP_CONV_NAMETOID;
memset(&msg, 0, sizeof(msg));
msg.data = im;
msg.len = sizeof(*im);
add_wait_queue(&idmap->idmap_wq, &wq);
if (rpc_queue_upcall(idmap->idmap_dentry->d_inode, &msg) < 0) {
remove_wait_queue(&idmap->idmap_wq, &wq);
goto out;
}
set_current_state(TASK_UNINTERRUPTIBLE);
mutex_unlock(&idmap->idmap_im_lock);
schedule();
__set_current_state(TASK_RUNNING);
remove_wait_queue(&idmap->idmap_wq, &wq);
mutex_lock(&idmap->idmap_im_lock);
if (im->im_status & IDMAP_STATUS_SUCCESS) {
*id = im->im_id;
ret = 0;
}
out:
memset(im, 0, sizeof(*im));
mutex_unlock(&idmap->idmap_im_lock);
mutex_unlock(&idmap->idmap_lock);
return ret;
}
/*
* ID -> Name
*/
static int
nfs_idmap_name(struct idmap *idmap, struct idmap_hashtable *h,
__u32 id, char *name)
{
struct rpc_pipe_msg msg;
struct idmap_msg *im;
struct idmap_hashent *he;
DECLARE_WAITQUEUE(wq, current);
int ret = -EIO;
unsigned int len;
im = &idmap->idmap_im;
mutex_lock(&idmap->idmap_lock);
mutex_lock(&idmap->idmap_im_lock);
he = idmap_lookup_id(h, id);
if (he) {
memcpy(name, he->ih_name, he->ih_namelen);
ret = he->ih_namelen;
goto out;
}
memset(im, 0, sizeof(*im));
im->im_type = h->h_type;
im->im_conv = IDMAP_CONV_IDTONAME;
im->im_id = id;
memset(&msg, 0, sizeof(msg));
msg.data = im;
msg.len = sizeof(*im);
add_wait_queue(&idmap->idmap_wq, &wq);
if (rpc_queue_upcall(idmap->idmap_dentry->d_inode, &msg) < 0) {
remove_wait_queue(&idmap->idmap_wq, &wq);
goto out;
}
set_current_state(TASK_UNINTERRUPTIBLE);
mutex_unlock(&idmap->idmap_im_lock);
schedule();
__set_current_state(TASK_RUNNING);
remove_wait_queue(&idmap->idmap_wq, &wq);
mutex_lock(&idmap->idmap_im_lock);
if (im->im_status & IDMAP_STATUS_SUCCESS) {
if ((len = strnlen(im->im_name, IDMAP_NAMESZ)) == 0)
goto out;
memcpy(name, im->im_name, len);
ret = len;
}
out:
memset(im, 0, sizeof(*im));
mutex_unlock(&idmap->idmap_im_lock);
mutex_unlock(&idmap->idmap_lock);
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 idmap_msg im_in, *im = &idmap->idmap_im;
struct idmap_hashtable *h;
struct idmap_hashent *he = NULL;
size_t namelen_in;
int ret;
if (mlen != sizeof(im_in))
return -ENOSPC;
if (copy_from_user(&im_in, src, mlen) != 0)
return -EFAULT;
mutex_lock(&idmap->idmap_im_lock);
ret = mlen;
im->im_status = im_in.im_status;
/* If we got an error, terminate now, and wake up pending upcalls */
if (!(im_in.im_status & IDMAP_STATUS_SUCCESS)) {
wake_up(&idmap->idmap_wq);
goto out;
}
/* Sanity checking of strings */
ret = -EINVAL;
namelen_in = strnlen(im_in.im_name, IDMAP_NAMESZ);
if (namelen_in == 0 || namelen_in == IDMAP_NAMESZ)
goto out;
switch (im_in.im_type) {
case IDMAP_TYPE_USER:
h = &idmap->idmap_user_hash;
break;
case IDMAP_TYPE_GROUP:
h = &idmap->idmap_group_hash;
break;
default:
goto out;
}
switch (im_in.im_conv) {
case IDMAP_CONV_IDTONAME:
/* Did we match the current upcall? */
if (im->im_conv == IDMAP_CONV_IDTONAME
&& im->im_type == im_in.im_type
&& im->im_id == im_in.im_id) {
/* Yes: copy string, including the terminating '\0' */
memcpy(im->im_name, im_in.im_name, namelen_in);
im->im_name[namelen_in] = '\0';
wake_up(&idmap->idmap_wq);
}
he = idmap_alloc_id(h, im_in.im_id);
break;
case IDMAP_CONV_NAMETOID:
/* Did we match the current upcall? */
if (im->im_conv == IDMAP_CONV_NAMETOID
&& im->im_type == im_in.im_type
&& strnlen(im->im_name, IDMAP_NAMESZ) == namelen_in
&& memcmp(im->im_name, im_in.im_name, namelen_in) == 0) {
im->im_id = im_in.im_id;
wake_up(&idmap->idmap_wq);
}
he = idmap_alloc_name(h, im_in.im_name, namelen_in);
break;
default:
goto out;
}
/* If the entry is valid, also copy it to the cache */
if (he != NULL)
idmap_update_entry(he, im_in.im_name, namelen_in, im_in.im_id);
ret = mlen;
out:
mutex_unlock(&idmap->idmap_im_lock);
return ret;
}
static void
idmap_pipe_destroy_msg(struct rpc_pipe_msg *msg)
{
struct idmap_msg *im = msg->data;
struct idmap *idmap = container_of(im, struct idmap, idmap_im);
if (msg->errno >= 0)
return;
mutex_lock(&idmap->idmap_im_lock);
im->im_status = IDMAP_STATUS_LOOKUPFAIL;
wake_up(&idmap->idmap_wq);
mutex_unlock(&idmap->idmap_im_lock);
}
/*
* Fowler/Noll/Vo hash
* http://www.isthe.com/chongo/tech/comp/fnv/
*/
#define FNV_P_32 ((unsigned int)0x01000193) /* 16777619 */
#define FNV_1_32 ((unsigned int)0x811c9dc5) /* 2166136261 */
static unsigned int fnvhash32(const void *buf, size_t buflen)
{
const unsigned char *p, *end = (const unsigned char *)buf + buflen;
unsigned int hash = FNV_1_32;
for (p = buf; p < end; p++) {
hash *= FNV_P_32;
hash ^= (unsigned int)*p;
}
return hash;
}
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_id(idmap, &idmap->idmap_user_hash, name, namelen, uid);
}
int nfs_map_group_to_gid(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_id(idmap, &idmap->idmap_group_hash, name, namelen, uid);
}
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_name(idmap, &idmap->idmap_user_hash, uid, buf);
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 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_name(idmap, &idmap->idmap_group_hash, uid, buf);
if (ret < 0)
ret = nfs_map_numeric_to_string(uid, buf, buflen);
return ret;
}
#endif /* CONFIG_NFS_USE_NEW_IDMAPPER */