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DEFINITIONS
This source file includes following definitions.
- param_set_idmap_timeout
- nfs_idmap_new
- nfs_idmap_delete
- idmap_name_hash
- idmap_lookup_name
- idmap_id_hash
- idmap_lookup_id
- idmap_alloc_name
- idmap_alloc_id
- idmap_update_entry
- nfs_idmap_id
- nfs_idmap_name
- idmap_pipe_upcall
- idmap_pipe_downcall
- idmap_pipe_destroy_msg
- fnvhash32
- nfs_map_name_to_uid
- nfs_map_group_to_gid
- nfs_map_uid_to_name
- nfs_map_gid_to_group
/*
* 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/module.h>
#include <linux/mutex.h>
#include <linux/init.h>
#include <linux/types.h>
#include <linux/slab.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 <linux/nfs_idmap.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_upcall(struct file *, struct rpc_pipe_msg *,
char __user *, size_t);
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 struct rpc_pipe_ops idmap_upcall_ops = {
.upcall = idmap_pipe_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_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;
}
/* RPC pipefs upcall/downcall routines */
static ssize_t
idmap_pipe_upcall(struct file *filp, struct rpc_pipe_msg *msg,
char __user *dst, size_t buflen)
{
char *data = (char *)msg->data + msg->copied;
size_t mlen = min(msg->len, buflen);
unsigned long left;
left = copy_to_user(dst, data, mlen);
if (left == mlen) {
msg->errno = -EFAULT;
return -EFAULT;
}
mlen -= left;
msg->copied += mlen;
msg->errno = 0;
return mlen;
}
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(struct nfs_client *clp, const char *name, size_t namelen, __u32 *uid)
{
struct idmap *idmap = clp->cl_idmap;
return nfs_idmap_id(idmap, &idmap->idmap_user_hash, name, namelen, uid);
}
int nfs_map_group_to_gid(struct nfs_client *clp, const char *name, size_t namelen, __u32 *uid)
{
struct idmap *idmap = clp->cl_idmap;
return nfs_idmap_id(idmap, &idmap->idmap_group_hash, name, namelen, uid);
}
int nfs_map_uid_to_name(struct nfs_client *clp, __u32 uid, char *buf)
{
struct idmap *idmap = clp->cl_idmap;
return nfs_idmap_name(idmap, &idmap->idmap_user_hash, uid, buf);
}
int nfs_map_gid_to_group(struct nfs_client *clp, __u32 uid, char *buf)
{
struct idmap *idmap = clp->cl_idmap;
return nfs_idmap_name(idmap, &idmap->idmap_group_hash, uid, buf);
}