[net-next-2.6.git] / 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/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 const 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_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;
}

/* 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);
}
Commit	Line	Data
1da177e4 LT	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
	37	#include <linux/module.h>
c9d5128a	38	#include <linux/mutex.h>
1da177e4 LT	39	#include <linux/init.h>
	40	#include <linux/types.h>
	41	#include <linux/slab.h>
	42	#include <linux/socket.h>
	43	#include <linux/in.h>
	44	#include <linux/sched.h>
	45
	46	#include <linux/sunrpc/clnt.h>
	47	#include <linux/workqueue.h>
	48	#include <linux/sunrpc/rpc_pipe_fs.h>
	49
1da177e4 LT	50	#include <linux/nfs_fs.h>
	51
	52	#include <linux/nfs_idmap.h>
4ce79717	53	#include "nfs4_fs.h"
1da177e4 LT	54
	55	#define IDMAP_HASH_SZ 128
	56
58df095b TM	57	/* Default cache timeout is 10 minutes */
	58	unsigned int nfs_idmap_cache_timeout = 600 * HZ;
	59
7d4e2747 DH	60	static int param_set_idmap_timeout(const char val, struct kernel_param kp)
	61	{
	62	char *endp;
	63	int num = simple_strtol(val, &endp, 0);
	64	int jif = num * HZ;
	65	if (endp == val \|\| *endp \|\| num < 0 \|\| jif < num)
	66	return -EINVAL;
	67	((int )kp->arg) = jif;
	68	return 0;
	69	}
	70
	71	module_param_call(idmap_cache_timeout, param_set_idmap_timeout, param_get_int,
	72	&nfs_idmap_cache_timeout, 0644);
	73
1da177e4	74	struct idmap_hashent {
369af0f1 CL	75	unsigned long ih_expires;
369af0f1 CL	76	__u32 ih_id;
d24aae41	77	size_t ih_namelen;
369af0f1	78	char ih_name[IDMAP_NAMESZ];
1da177e4 LT	79	};
	80
	81	struct idmap_hashtable {
369af0f1 CL	82	__u8 h_type;
369af0f1 CL	83	struct idmap_hashent h_entries[IDMAP_HASH_SZ];
1da177e4 LT	84	};
	85
	86	struct idmap {
369af0f1 CL	87	struct dentry *idmap_dentry;
	88	wait_queue_head_t idmap_wq;
	89	struct idmap_msg idmap_im;
	90	struct mutex idmap_lock; /* Serializes upcalls */
	91	struct mutex idmap_im_lock; /* Protects the hashtable */
	92	struct idmap_hashtable idmap_user_hash;
	93	struct idmap_hashtable idmap_group_hash;
1da177e4 LT	94	};
1da177e4 LT	95
369af0f1 CL	96	static ssize_t idmap_pipe_upcall(struct file , struct rpc_pipe_msg ,
	97	char __user *, size_t);
	98	static ssize_t idmap_pipe_downcall(struct file , const char __user ,
	99	size_t);
	100	static void idmap_pipe_destroy_msg(struct rpc_pipe_msg *);
1da177e4 LT	101
	102	static unsigned int fnvhash32(const void *, size_t);
	103
b693ba4a	104	static const struct rpc_pipe_ops idmap_upcall_ops = {
369af0f1 CL	105	.upcall = idmap_pipe_upcall,
	106	.downcall = idmap_pipe_downcall,
	107	.destroy_msg = idmap_pipe_destroy_msg,
1da177e4 LT	108	};
1da177e4 LT	109
b7162792	110	int
adfa6f98	111	nfs_idmap_new(struct nfs_client *clp)
1da177e4 LT	112	{
1da177e4 LT	113	struct idmap *idmap;
b7162792	114	int error;
1da177e4	115
54ceac45	116	BUG_ON(clp->cl_idmap != NULL);
b7162792	117
369af0f1 CL	118	idmap = kzalloc(sizeof(*idmap), GFP_KERNEL);
	119	if (idmap == NULL)
	120	return -ENOMEM;
1da177e4	121
7d217cac TM	122	idmap->idmap_dentry = rpc_mkpipe(clp->cl_rpcclient->cl_path.dentry,
7d217cac TM	123	"idmap", idmap, &idmap_upcall_ops, 0);
369af0f1	124	if (IS_ERR(idmap->idmap_dentry)) {
b7162792	125	error = PTR_ERR(idmap->idmap_dentry);
1da177e4	126	kfree(idmap);
b7162792	127	return error;
1da177e4 LT	128	}
1da177e4 LT	129
369af0f1 CL	130	mutex_init(&idmap->idmap_lock);
369af0f1 CL	131	mutex_init(&idmap->idmap_im_lock);
1da177e4 LT	132	init_waitqueue_head(&idmap->idmap_wq);
	133	idmap->idmap_user_hash.h_type = IDMAP_TYPE_USER;
	134	idmap->idmap_group_hash.h_type = IDMAP_TYPE_GROUP;
	135
	136	clp->cl_idmap = idmap;
b7162792	137	return 0;
1da177e4 LT	138	}
	139
	140	void
adfa6f98	141	nfs_idmap_delete(struct nfs_client *clp)
1da177e4 LT	142	{
	143	struct idmap *idmap = clp->cl_idmap;
	144
	145	if (!idmap)
	146	return;
5d67476f	147	rpc_unlink(idmap->idmap_dentry);
1da177e4 LT	148	clp->cl_idmap = NULL;
	149	kfree(idmap);
	150	}
	151
	152	/*
	153	* Helper routines for manipulating the hashtable
	154	*/
	155	static inline struct idmap_hashent *
	156	idmap_name_hash(struct idmap_hashtable* h, const char *name, size_t len)
	157	{
	158	return &h->h_entries[fnvhash32(name, len) % IDMAP_HASH_SZ];
	159	}
	160
	161	static struct idmap_hashent *
	162	idmap_lookup_name(struct idmap_hashtable h, const char name, size_t len)
	163	{
	164	struct idmap_hashent *he = idmap_name_hash(h, name, len);
	165
	166	if (he->ih_namelen != len \|\| memcmp(he->ih_name, name, len) != 0)
	167	return NULL;
58df095b TM	168	if (time_after(jiffies, he->ih_expires))
58df095b TM	169	return NULL;
1da177e4 LT	170	return he;
	171	}
	172
	173	static inline struct idmap_hashent *
	174	idmap_id_hash(struct idmap_hashtable* h, __u32 id)
	175	{
	176	return &h->h_entries[fnvhash32(&id, sizeof(id)) % IDMAP_HASH_SZ];
	177	}
	178
	179	static struct idmap_hashent *
	180	idmap_lookup_id(struct idmap_hashtable *h, __u32 id)
	181	{
	182	struct idmap_hashent *he = idmap_id_hash(h, id);
	183	if (he->ih_id != id \|\| he->ih_namelen == 0)
	184	return NULL;
58df095b TM	185	if (time_after(jiffies, he->ih_expires))
58df095b TM	186	return NULL;
1da177e4 LT	187	return he;
	188	}
	189
	190	/*
	191	* Routines for allocating new entries in the hashtable.
	192	* For now, we just have 1 entry per bucket, so it's all
	193	* pretty trivial.
	194	*/
	195	static inline struct idmap_hashent *
d24aae41	196	idmap_alloc_name(struct idmap_hashtable h, char name, size_t len)
1da177e4 LT	197	{
	198	return idmap_name_hash(h, name, len);
	199	}
	200
	201	static inline struct idmap_hashent *
	202	idmap_alloc_id(struct idmap_hashtable *h, __u32 id)
	203	{
	204	return idmap_id_hash(h, id);
	205	}
	206
	207	static void
	208	idmap_update_entry(struct idmap_hashent he, const char name,
	209	size_t namelen, __u32 id)
	210	{
	211	he->ih_id = id;
	212	memcpy(he->ih_name, name, namelen);
	213	he->ih_name[namelen] = '\0';
	214	he->ih_namelen = namelen;
58df095b	215	he->ih_expires = jiffies + nfs_idmap_cache_timeout;
1da177e4 LT	216	}
	217
	218	/*
	219	* Name -> ID
	220	*/
	221	static int
	222	nfs_idmap_id(struct idmap idmap, struct idmap_hashtable h,
	223	const char name, size_t namelen, __u32 id)
	224	{
	225	struct rpc_pipe_msg msg;
	226	struct idmap_msg *im;
	227	struct idmap_hashent *he;
	228	DECLARE_WAITQUEUE(wq, current);
	229	int ret = -EIO;
	230
	231	im = &idmap->idmap_im;
	232
	233	/*
	234	* String sanity checks
	235	* Note that the userland daemon expects NUL terminated strings
	236	*/
	237	for (;;) {
	238	if (namelen == 0)
	239	return -EINVAL;
	240	if (name[namelen-1] != '\0')
	241	break;
	242	namelen--;
	243	}
	244	if (namelen >= IDMAP_NAMESZ)
	245	return -EINVAL;
	246
c9d5128a IM	247	mutex_lock(&idmap->idmap_lock);
c9d5128a IM	248	mutex_lock(&idmap->idmap_im_lock);
1da177e4 LT	249
	250	he = idmap_lookup_name(h, name, namelen);
	251	if (he != NULL) {
	252	*id = he->ih_id;
	253	ret = 0;
	254	goto out;
	255	}
	256
	257	memset(im, 0, sizeof(*im));
	258	memcpy(im->im_name, name, namelen);
	259
	260	im->im_type = h->h_type;
	261	im->im_conv = IDMAP_CONV_NAMETOID;
	262
	263	memset(&msg, 0, sizeof(msg));
	264	msg.data = im;
	265	msg.len = sizeof(*im);
	266
	267	add_wait_queue(&idmap->idmap_wq, &wq);
	268	if (rpc_queue_upcall(idmap->idmap_dentry->d_inode, &msg) < 0) {
	269	remove_wait_queue(&idmap->idmap_wq, &wq);
	270	goto out;
	271	}
	272
	273	set_current_state(TASK_UNINTERRUPTIBLE);
c9d5128a	274	mutex_unlock(&idmap->idmap_im_lock);
1da177e4	275	schedule();
fee7f23f	276	__set_current_state(TASK_RUNNING);
1da177e4	277	remove_wait_queue(&idmap->idmap_wq, &wq);
c9d5128a	278	mutex_lock(&idmap->idmap_im_lock);
1da177e4 LT	279
	280	if (im->im_status & IDMAP_STATUS_SUCCESS) {
	281	*id = im->im_id;
	282	ret = 0;
	283	}
	284
	285	out:
	286	memset(im, 0, sizeof(*im));
c9d5128a IM	287	mutex_unlock(&idmap->idmap_im_lock);
c9d5128a IM	288	mutex_unlock(&idmap->idmap_lock);
369af0f1	289	return ret;
1da177e4 LT	290	}
	291
	292	/*
	293	* ID -> Name
	294	*/
	295	static int
	296	nfs_idmap_name(struct idmap idmap, struct idmap_hashtable h,
	297	__u32 id, char *name)
	298	{
	299	struct rpc_pipe_msg msg;
	300	struct idmap_msg *im;
	301	struct idmap_hashent *he;
	302	DECLARE_WAITQUEUE(wq, current);
	303	int ret = -EIO;
	304	unsigned int len;
	305
	306	im = &idmap->idmap_im;
	307
c9d5128a IM	308	mutex_lock(&idmap->idmap_lock);
c9d5128a IM	309	mutex_lock(&idmap->idmap_im_lock);
1da177e4 LT	310
1da177e4 LT	311	he = idmap_lookup_id(h, id);
90dc7d27	312	if (he) {
1da177e4 LT	313	memcpy(name, he->ih_name, he->ih_namelen);
	314	ret = he->ih_namelen;
	315	goto out;
	316	}
	317
	318	memset(im, 0, sizeof(*im));
	319	im->im_type = h->h_type;
	320	im->im_conv = IDMAP_CONV_IDTONAME;
	321	im->im_id = id;
	322
	323	memset(&msg, 0, sizeof(msg));
	324	msg.data = im;
	325	msg.len = sizeof(*im);
	326
	327	add_wait_queue(&idmap->idmap_wq, &wq);
	328
	329	if (rpc_queue_upcall(idmap->idmap_dentry->d_inode, &msg) < 0) {
	330	remove_wait_queue(&idmap->idmap_wq, &wq);
	331	goto out;
	332	}
	333
	334	set_current_state(TASK_UNINTERRUPTIBLE);
c9d5128a	335	mutex_unlock(&idmap->idmap_im_lock);
1da177e4	336	schedule();
fee7f23f	337	__set_current_state(TASK_RUNNING);
1da177e4	338	remove_wait_queue(&idmap->idmap_wq, &wq);
c9d5128a	339	mutex_lock(&idmap->idmap_im_lock);
1da177e4 LT	340
	341	if (im->im_status & IDMAP_STATUS_SUCCESS) {
	342	if ((len = strnlen(im->im_name, IDMAP_NAMESZ)) == 0)
	343	goto out;
	344	memcpy(name, im->im_name, len);
	345	ret = len;
	346	}
	347
	348	out:
	349	memset(im, 0, sizeof(*im));
c9d5128a IM	350	mutex_unlock(&idmap->idmap_im_lock);
c9d5128a IM	351	mutex_unlock(&idmap->idmap_lock);
1da177e4 LT	352	return ret;
	353	}
	354
	355	/* RPC pipefs upcall/downcall routines */
	356	static ssize_t
	357	idmap_pipe_upcall(struct file filp, struct rpc_pipe_msg msg,
369af0f1	358	char __user *dst, size_t buflen)
1da177e4	359	{
369af0f1	360	char data = (char )msg->data + msg->copied;
a661b77f CL	361	size_t mlen = min(msg->len, buflen);
a661b77f CL	362	unsigned long left;
1da177e4	363
369af0f1	364	left = copy_to_user(dst, data, mlen);
a661b77f CL	365	if (left == mlen) {
	366	msg->errno = -EFAULT;
	367	return -EFAULT;
1da177e4	368	}
a661b77f	369
1da177e4 LT	370	mlen -= left;
	371	msg->copied += mlen;
	372	msg->errno = 0;
369af0f1	373	return mlen;
1da177e4 LT	374	}
	375
	376	static ssize_t
	377	idmap_pipe_downcall(struct file filp, const char __user src, size_t mlen)
	378	{
369af0f1	379	struct rpc_inode *rpci = RPC_I(filp->f_path.dentry->d_inode);
1da177e4 LT	380	struct idmap idmap = (struct idmap )rpci->private;
	381	struct idmap_msg im_in, *im = &idmap->idmap_im;
	382	struct idmap_hashtable *h;
	383	struct idmap_hashent *he = NULL;
d24aae41	384	size_t namelen_in;
1da177e4 LT	385	int ret;
1da177e4 LT	386
369af0f1 CL	387	if (mlen != sizeof(im_in))
369af0f1 CL	388	return -ENOSPC;
1da177e4	389
369af0f1 CL	390	if (copy_from_user(&im_in, src, mlen) != 0)
369af0f1 CL	391	return -EFAULT;
1da177e4	392
c9d5128a	393	mutex_lock(&idmap->idmap_im_lock);
1da177e4 LT	394
	395	ret = mlen;
	396	im->im_status = im_in.im_status;
	397	/* If we got an error, terminate now, and wake up pending upcalls */
	398	if (!(im_in.im_status & IDMAP_STATUS_SUCCESS)) {
	399	wake_up(&idmap->idmap_wq);
	400	goto out;
	401	}
	402
	403	/* Sanity checking of strings */
	404	ret = -EINVAL;
	405	namelen_in = strnlen(im_in.im_name, IDMAP_NAMESZ);
	406	if (namelen_in == 0 \|\| namelen_in == IDMAP_NAMESZ)
	407	goto out;
	408
	409	switch (im_in.im_type) {
	410	case IDMAP_TYPE_USER:
	411	h = &idmap->idmap_user_hash;
	412	break;
	413	case IDMAP_TYPE_GROUP:
	414	h = &idmap->idmap_group_hash;
	415	break;
	416	default:
	417	goto out;
	418	}
	419
	420	switch (im_in.im_conv) {
	421	case IDMAP_CONV_IDTONAME:
	422	/* Did we match the current upcall? */
	423	if (im->im_conv == IDMAP_CONV_IDTONAME
	424	&& im->im_type == im_in.im_type
	425	&& im->im_id == im_in.im_id) {
	426	/* Yes: copy string, including the terminating '\0' */
	427	memcpy(im->im_name, im_in.im_name, namelen_in);
	428	im->im_name[namelen_in] = '\0';
	429	wake_up(&idmap->idmap_wq);
	430	}
	431	he = idmap_alloc_id(h, im_in.im_id);
	432	break;
	433	case IDMAP_CONV_NAMETOID:
	434	/* Did we match the current upcall? */
	435	if (im->im_conv == IDMAP_CONV_NAMETOID
	436	&& im->im_type == im_in.im_type
	437	&& strnlen(im->im_name, IDMAP_NAMESZ) == namelen_in
	438	&& memcmp(im->im_name, im_in.im_name, namelen_in) == 0) {
	439	im->im_id = im_in.im_id;
	440	wake_up(&idmap->idmap_wq);
	441	}
	442	he = idmap_alloc_name(h, im_in.im_name, namelen_in);
	443	break;
	444	default:
	445	goto out;
	446	}
	447
	448	/* If the entry is valid, also copy it to the cache */
	449	if (he != NULL)
	450	idmap_update_entry(he, im_in.im_name, namelen_in, im_in.im_id);
	451	ret = mlen;
	452	out:
c9d5128a	453	mutex_unlock(&idmap->idmap_im_lock);
1da177e4 LT	454	return ret;
	455	}
	456
75c96f85	457	static void
1da177e4 LT	458	idmap_pipe_destroy_msg(struct rpc_pipe_msg *msg)
	459	{
	460	struct idmap_msg *im = msg->data;
	461	struct idmap *idmap = container_of(im, struct idmap, idmap_im);
	462
	463	if (msg->errno >= 0)
	464	return;
c9d5128a	465	mutex_lock(&idmap->idmap_im_lock);
1da177e4 LT	466	im->im_status = IDMAP_STATUS_LOOKUPFAIL;
1da177e4 LT	467	wake_up(&idmap->idmap_wq);
c9d5128a	468	mutex_unlock(&idmap->idmap_im_lock);
1da177e4 LT	469	}
	470
	471	/*
	472	* Fowler/Noll/Vo hash
	473	* http://www.isthe.com/chongo/tech/comp/fnv/
	474	*/
	475
	476	#define FNV_P_32 ((unsigned int)0x01000193) /* 16777619 */
	477	#define FNV_1_32 ((unsigned int)0x811c9dc5) /* 2166136261 */
	478
	479	static unsigned int fnvhash32(const void *buf, size_t buflen)
	480	{
	481	const unsigned char p, end = (const unsigned char *)buf + buflen;
	482	unsigned int hash = FNV_1_32;
	483
	484	for (p = buf; p < end; p++) {
	485	hash *= FNV_P_32;
	486	hash ^= (unsigned int)*p;
	487	}
	488
369af0f1	489	return hash;
1da177e4 LT	490	}
1da177e4 LT	491
adfa6f98	492	int nfs_map_name_to_uid(struct nfs_client clp, const char name, size_t namelen, __u32 *uid)
1da177e4 LT	493	{
	494	struct idmap *idmap = clp->cl_idmap;
	495
	496	return nfs_idmap_id(idmap, &idmap->idmap_user_hash, name, namelen, uid);
	497	}
	498
adfa6f98	499	int nfs_map_group_to_gid(struct nfs_client clp, const char name, size_t namelen, __u32 *uid)
1da177e4 LT	500	{
	501	struct idmap *idmap = clp->cl_idmap;
	502
	503	return nfs_idmap_id(idmap, &idmap->idmap_group_hash, name, namelen, uid);
	504	}
	505
adfa6f98	506	int nfs_map_uid_to_name(struct nfs_client clp, __u32 uid, char buf)
1da177e4 LT	507	{
	508	struct idmap *idmap = clp->cl_idmap;
	509
	510	return nfs_idmap_name(idmap, &idmap->idmap_user_hash, uid, buf);
	511	}
adfa6f98	512	int nfs_map_gid_to_group(struct nfs_client clp, __u32 uid, char buf)
1da177e4 LT	513	{
	514	struct idmap *idmap = clp->cl_idmap;
	515
	516	return nfs_idmap_name(idmap, &idmap->idmap_group_hash, uid, buf);
	517	}
	518