[linux.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 <[email protected]>
 *
 *  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_sb.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;

struct idmap_hashent {
	unsigned long ih_expires;
	__u32 ih_id;
	int ih_namelen;
	char ih_name[IDMAP_NAMESZ];
};

struct idmap_hashtable {
	__u8 h_type;
	struct idmap_hashent h_entries[IDMAP_HASH_SZ];
};

struct idmap {
	char                  idmap_path[48];
	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,
};

void
nfs_idmap_new(struct nfs4_client *clp)
{
	struct idmap *idmap;

	if (clp->cl_idmap != NULL)
		return;
        if ((idmap = kzalloc(sizeof(*idmap), GFP_KERNEL)) == NULL)
                return;

	snprintf(idmap->idmap_path, sizeof(idmap->idmap_path),
	    "%s/idmap", clp->cl_rpcclient->cl_pathname);

        idmap->idmap_dentry = rpc_mkpipe(idmap->idmap_path,
	    idmap, &idmap_upcall_ops, 0);
        if (IS_ERR(idmap->idmap_dentry)) {
		kfree(idmap);
		return;
	}

        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;
}

void
nfs_idmap_delete(struct nfs4_client *clp)
{
	struct idmap *idmap = clp->cl_idmap;

	if (!idmap)
		return;
	dput(idmap->idmap_dentry);
	idmap->idmap_dentry = NULL;
	rpc_unlink(idmap->idmap_path);
	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, unsigned 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();
	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 != 0) {
		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();
	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;
        ssize_t mlen = msg->len - msg->copied;
        ssize_t left;

        if (mlen > buflen)
                mlen = buflen;

        left = copy_to_user(dst, data, mlen);
	if (left < 0) {
		msg->errno = left;
		return left;
	}
	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_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;
	int 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 nfs4_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 nfs4_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 nfs4_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 nfs4_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 <[email protected]>
	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
	50	#include <linux/nfs_fs_sb.h>
	51	#include <linux/nfs_fs.h>
	52
	53	#include <linux/nfs_idmap.h>
4ce79717	54	#include "nfs4_fs.h"
1da177e4 LT	55
	56	#define IDMAP_HASH_SZ 128
	57
58df095b TM	58	/* Default cache timeout is 10 minutes */
	59	unsigned int nfs_idmap_cache_timeout = 600 * HZ;
	60
1da177e4	61	struct idmap_hashent {
58df095b	62	unsigned long ih_expires;
1da177e4 LT	63	__u32 ih_id;
	64	int ih_namelen;
	65	char ih_name[IDMAP_NAMESZ];
	66	};
	67
	68	struct idmap_hashtable {
	69	__u8 h_type;
	70	struct idmap_hashent h_entries[IDMAP_HASH_SZ];
	71	};
	72
	73	struct idmap {
	74	char idmap_path[48];
	75	struct dentry *idmap_dentry;
	76	wait_queue_head_t idmap_wq;
	77	struct idmap_msg idmap_im;
c9d5128a IM	78	struct mutex idmap_lock; /* Serializes upcalls */
c9d5128a IM	79	struct mutex idmap_im_lock; /* Protects the hashtable */
1da177e4 LT	80	struct idmap_hashtable idmap_user_hash;
	81	struct idmap_hashtable idmap_group_hash;
	82	};
	83
	84	static ssize_t idmap_pipe_upcall(struct file , struct rpc_pipe_msg ,
	85	char __user *, size_t);
	86	static ssize_t idmap_pipe_downcall(struct file , const char __user ,
	87	size_t);
75c96f85	88	static void idmap_pipe_destroy_msg(struct rpc_pipe_msg *);
1da177e4 LT	89
	90	static unsigned int fnvhash32(const void *, size_t);
	91
	92	static struct rpc_pipe_ops idmap_upcall_ops = {
	93	.upcall = idmap_pipe_upcall,
	94	.downcall = idmap_pipe_downcall,
	95	.destroy_msg = idmap_pipe_destroy_msg,
	96	};
	97
	98	void
	99	nfs_idmap_new(struct nfs4_client *clp)
	100	{
	101	struct idmap *idmap;
	102
	103	if (clp->cl_idmap != NULL)
	104	return;
bd647545	105	if ((idmap = kzalloc(sizeof(*idmap), GFP_KERNEL)) == NULL)
1da177e4 LT	106	return;
1da177e4 LT	107
1da177e4 LT	108	snprintf(idmap->idmap_path, sizeof(idmap->idmap_path),
	109	"%s/idmap", clp->cl_rpcclient->cl_pathname);
	110
	111	idmap->idmap_dentry = rpc_mkpipe(idmap->idmap_path,
	112	idmap, &idmap_upcall_ops, 0);
	113	if (IS_ERR(idmap->idmap_dentry)) {
	114	kfree(idmap);
	115	return;
	116	}
	117
c9d5128a IM	118	mutex_init(&idmap->idmap_lock);
c9d5128a IM	119	mutex_init(&idmap->idmap_im_lock);
1da177e4 LT	120	init_waitqueue_head(&idmap->idmap_wq);
	121	idmap->idmap_user_hash.h_type = IDMAP_TYPE_USER;
	122	idmap->idmap_group_hash.h_type = IDMAP_TYPE_GROUP;
	123
	124	clp->cl_idmap = idmap;
	125	}
	126
	127	void
	128	nfs_idmap_delete(struct nfs4_client *clp)
	129	{
	130	struct idmap *idmap = clp->cl_idmap;
	131
	132	if (!idmap)
	133	return;
12de3b35 TM	134	dput(idmap->idmap_dentry);
12de3b35 TM	135	idmap->idmap_dentry = NULL;
1da177e4 LT	136	rpc_unlink(idmap->idmap_path);
	137	clp->cl_idmap = NULL;
	138	kfree(idmap);
	139	}
	140
	141	/*
	142	* Helper routines for manipulating the hashtable
	143	*/
	144	static inline struct idmap_hashent *
	145	idmap_name_hash(struct idmap_hashtable* h, const char *name, size_t len)
	146	{
	147	return &h->h_entries[fnvhash32(name, len) % IDMAP_HASH_SZ];
	148	}
	149
	150	static struct idmap_hashent *
	151	idmap_lookup_name(struct idmap_hashtable h, const char name, size_t len)
	152	{
	153	struct idmap_hashent *he = idmap_name_hash(h, name, len);
	154
	155	if (he->ih_namelen != len \|\| memcmp(he->ih_name, name, len) != 0)
	156	return NULL;
58df095b TM	157	if (time_after(jiffies, he->ih_expires))
58df095b TM	158	return NULL;
1da177e4 LT	159	return he;
	160	}
	161
	162	static inline struct idmap_hashent *
	163	idmap_id_hash(struct idmap_hashtable* h, __u32 id)
	164	{
	165	return &h->h_entries[fnvhash32(&id, sizeof(id)) % IDMAP_HASH_SZ];
	166	}
	167
	168	static struct idmap_hashent *
	169	idmap_lookup_id(struct idmap_hashtable *h, __u32 id)
	170	{
	171	struct idmap_hashent *he = idmap_id_hash(h, id);
	172	if (he->ih_id != id \|\| he->ih_namelen == 0)
	173	return NULL;
58df095b TM	174	if (time_after(jiffies, he->ih_expires))
58df095b TM	175	return NULL;
1da177e4 LT	176	return he;
	177	}
	178
	179	/*
	180	* Routines for allocating new entries in the hashtable.
	181	* For now, we just have 1 entry per bucket, so it's all
	182	* pretty trivial.
	183	*/
	184	static inline struct idmap_hashent *
	185	idmap_alloc_name(struct idmap_hashtable h, char name, unsigned len)
	186	{
	187	return idmap_name_hash(h, name, len);
	188	}
	189
	190	static inline struct idmap_hashent *
	191	idmap_alloc_id(struct idmap_hashtable *h, __u32 id)
	192	{
	193	return idmap_id_hash(h, id);
	194	}
	195
	196	static void
	197	idmap_update_entry(struct idmap_hashent he, const char name,
	198	size_t namelen, __u32 id)
	199	{
	200	he->ih_id = id;
	201	memcpy(he->ih_name, name, namelen);
	202	he->ih_name[namelen] = '\0';
	203	he->ih_namelen = namelen;
58df095b	204	he->ih_expires = jiffies + nfs_idmap_cache_timeout;
1da177e4 LT	205	}
	206
	207	/*
	208	* Name -> ID
	209	*/
	210	static int
	211	nfs_idmap_id(struct idmap idmap, struct idmap_hashtable h,
	212	const char name, size_t namelen, __u32 id)
	213	{
	214	struct rpc_pipe_msg msg;
	215	struct idmap_msg *im;
	216	struct idmap_hashent *he;
	217	DECLARE_WAITQUEUE(wq, current);
	218	int ret = -EIO;
	219
	220	im = &idmap->idmap_im;
	221
	222	/*
	223	* String sanity checks
	224	* Note that the userland daemon expects NUL terminated strings
	225	*/
	226	for (;;) {
	227	if (namelen == 0)
	228	return -EINVAL;
	229	if (name[namelen-1] != '\0')
	230	break;
	231	namelen--;
	232	}
	233	if (namelen >= IDMAP_NAMESZ)
	234	return -EINVAL;
	235
c9d5128a IM	236	mutex_lock(&idmap->idmap_lock);
c9d5128a IM	237	mutex_lock(&idmap->idmap_im_lock);
1da177e4 LT	238
	239	he = idmap_lookup_name(h, name, namelen);
	240	if (he != NULL) {
	241	*id = he->ih_id;
	242	ret = 0;
	243	goto out;
	244	}
	245
	246	memset(im, 0, sizeof(*im));
	247	memcpy(im->im_name, name, namelen);
	248
	249	im->im_type = h->h_type;
	250	im->im_conv = IDMAP_CONV_NAMETOID;
	251
	252	memset(&msg, 0, sizeof(msg));
	253	msg.data = im;
	254	msg.len = sizeof(*im);
	255
	256	add_wait_queue(&idmap->idmap_wq, &wq);
	257	if (rpc_queue_upcall(idmap->idmap_dentry->d_inode, &msg) < 0) {
	258	remove_wait_queue(&idmap->idmap_wq, &wq);
	259	goto out;
	260	}
	261
	262	set_current_state(TASK_UNINTERRUPTIBLE);
c9d5128a	263	mutex_unlock(&idmap->idmap_im_lock);
1da177e4 LT	264	schedule();
	265	current->state = TASK_RUNNING;
	266	remove_wait_queue(&idmap->idmap_wq, &wq);
c9d5128a	267	mutex_lock(&idmap->idmap_im_lock);
1da177e4 LT	268
	269	if (im->im_status & IDMAP_STATUS_SUCCESS) {
	270	*id = im->im_id;
	271	ret = 0;
	272	}
	273
	274	out:
	275	memset(im, 0, sizeof(*im));
c9d5128a IM	276	mutex_unlock(&idmap->idmap_im_lock);
c9d5128a IM	277	mutex_unlock(&idmap->idmap_lock);
1da177e4 LT	278	return (ret);
	279	}
	280
	281	/*
	282	* ID -> Name
	283	*/
	284	static int
	285	nfs_idmap_name(struct idmap idmap, struct idmap_hashtable h,
	286	__u32 id, char *name)
	287	{
	288	struct rpc_pipe_msg msg;
	289	struct idmap_msg *im;
	290	struct idmap_hashent *he;
	291	DECLARE_WAITQUEUE(wq, current);
	292	int ret = -EIO;
	293	unsigned int len;
	294
	295	im = &idmap->idmap_im;
	296
c9d5128a IM	297	mutex_lock(&idmap->idmap_lock);
c9d5128a IM	298	mutex_lock(&idmap->idmap_im_lock);
1da177e4 LT	299
	300	he = idmap_lookup_id(h, id);
	301	if (he != 0) {
	302	memcpy(name, he->ih_name, he->ih_namelen);
	303	ret = he->ih_namelen;
	304	goto out;
	305	}
	306
	307	memset(im, 0, sizeof(*im));
	308	im->im_type = h->h_type;
	309	im->im_conv = IDMAP_CONV_IDTONAME;
	310	im->im_id = id;
	311
	312	memset(&msg, 0, sizeof(msg));
	313	msg.data = im;
	314	msg.len = sizeof(*im);
	315
	316	add_wait_queue(&idmap->idmap_wq, &wq);
	317
	318	if (rpc_queue_upcall(idmap->idmap_dentry->d_inode, &msg) < 0) {
	319	remove_wait_queue(&idmap->idmap_wq, &wq);
	320	goto out;
	321	}
	322
	323	set_current_state(TASK_UNINTERRUPTIBLE);
c9d5128a	324	mutex_unlock(&idmap->idmap_im_lock);
1da177e4 LT	325	schedule();
	326	current->state = TASK_RUNNING;
	327	remove_wait_queue(&idmap->idmap_wq, &wq);
c9d5128a	328	mutex_lock(&idmap->idmap_im_lock);
1da177e4 LT	329
	330	if (im->im_status & IDMAP_STATUS_SUCCESS) {
	331	if ((len = strnlen(im->im_name, IDMAP_NAMESZ)) == 0)
	332	goto out;
	333	memcpy(name, im->im_name, len);
	334	ret = len;
	335	}
	336
	337	out:
	338	memset(im, 0, sizeof(*im));
c9d5128a IM	339	mutex_unlock(&idmap->idmap_im_lock);
c9d5128a IM	340	mutex_unlock(&idmap->idmap_lock);
1da177e4 LT	341	return ret;
	342	}
	343
	344	/* RPC pipefs upcall/downcall routines */
	345	static ssize_t
	346	idmap_pipe_upcall(struct file filp, struct rpc_pipe_msg msg,
	347	char __user *dst, size_t buflen)
	348	{
	349	char data = (char )msg->data + msg->copied;
	350	ssize_t mlen = msg->len - msg->copied;
	351	ssize_t left;
	352
	353	if (mlen > buflen)
	354	mlen = buflen;
	355
	356	left = copy_to_user(dst, data, mlen);
	357	if (left < 0) {
	358	msg->errno = left;
	359	return left;
	360	}
	361	mlen -= left;
	362	msg->copied += mlen;
	363	msg->errno = 0;
	364	return mlen;
	365	}
	366
	367	static ssize_t
	368	idmap_pipe_downcall(struct file filp, const char __user src, size_t mlen)
	369	{
	370	struct rpc_inode *rpci = RPC_I(filp->f_dentry->d_inode);
	371	struct idmap idmap = (struct idmap )rpci->private;
	372	struct idmap_msg im_in, *im = &idmap->idmap_im;
	373	struct idmap_hashtable *h;
	374	struct idmap_hashent *he = NULL;
	375	int namelen_in;
	376	int ret;
	377
	378	if (mlen != sizeof(im_in))
	379	return (-ENOSPC);
	380
	381	if (copy_from_user(&im_in, src, mlen) != 0)
	382	return (-EFAULT);
	383
c9d5128a	384	mutex_lock(&idmap->idmap_im_lock);
1da177e4 LT	385
	386	ret = mlen;
	387	im->im_status = im_in.im_status;
	388	/* If we got an error, terminate now, and wake up pending upcalls */
	389	if (!(im_in.im_status & IDMAP_STATUS_SUCCESS)) {
	390	wake_up(&idmap->idmap_wq);
	391	goto out;
	392	}
	393
	394	/* Sanity checking of strings */
	395	ret = -EINVAL;
	396	namelen_in = strnlen(im_in.im_name, IDMAP_NAMESZ);
	397	if (namelen_in == 0 \|\| namelen_in == IDMAP_NAMESZ)
	398	goto out;
	399
	400	switch (im_in.im_type) {
	401	case IDMAP_TYPE_USER:
	402	h = &idmap->idmap_user_hash;
	403	break;
	404	case IDMAP_TYPE_GROUP:
	405	h = &idmap->idmap_group_hash;
	406	break;
	407	default:
	408	goto out;
	409	}
	410
	411	switch (im_in.im_conv) {
	412	case IDMAP_CONV_IDTONAME:
	413	/* Did we match the current upcall? */
	414	if (im->im_conv == IDMAP_CONV_IDTONAME
	415	&& im->im_type == im_in.im_type
	416	&& im->im_id == im_in.im_id) {
	417	/* Yes: copy string, including the terminating '\0' */
	418	memcpy(im->im_name, im_in.im_name, namelen_in);
	419	im->im_name[namelen_in] = '\0';
	420	wake_up(&idmap->idmap_wq);
	421	}
	422	he = idmap_alloc_id(h, im_in.im_id);
	423	break;
	424	case IDMAP_CONV_NAMETOID:
	425	/* Did we match the current upcall? */
	426	if (im->im_conv == IDMAP_CONV_NAMETOID
	427	&& im->im_type == im_in.im_type
	428	&& strnlen(im->im_name, IDMAP_NAMESZ) == namelen_in
	429	&& memcmp(im->im_name, im_in.im_name, namelen_in) == 0) {
	430	im->im_id = im_in.im_id;
	431	wake_up(&idmap->idmap_wq);
	432	}
	433	he = idmap_alloc_name(h, im_in.im_name, namelen_in);
	434	break;
	435	default:
	436	goto out;
	437	}
	438
	439	/* If the entry is valid, also copy it to the cache */
	440	if (he != NULL)
	441	idmap_update_entry(he, im_in.im_name, namelen_in, im_in.im_id);
	442	ret = mlen;
	443	out:
c9d5128a	444	mutex_unlock(&idmap->idmap_im_lock);
1da177e4 LT	445	return ret;
	446	}
	447
75c96f85	448	static void
1da177e4 LT	449	idmap_pipe_destroy_msg(struct rpc_pipe_msg *msg)
	450	{
	451	struct idmap_msg *im = msg->data;
	452	struct idmap *idmap = container_of(im, struct idmap, idmap_im);
	453
	454	if (msg->errno >= 0)
	455	return;
c9d5128a	456	mutex_lock(&idmap->idmap_im_lock);
1da177e4 LT	457	im->im_status = IDMAP_STATUS_LOOKUPFAIL;
1da177e4 LT	458	wake_up(&idmap->idmap_wq);
c9d5128a	459	mutex_unlock(&idmap->idmap_im_lock);
1da177e4 LT	460	}
	461
	462	/*
	463	* Fowler/Noll/Vo hash
	464	* http://www.isthe.com/chongo/tech/comp/fnv/
	465	*/
	466
	467	#define FNV_P_32 ((unsigned int)0x01000193) /* 16777619 */
	468	#define FNV_1_32 ((unsigned int)0x811c9dc5) /* 2166136261 */
	469
	470	static unsigned int fnvhash32(const void *buf, size_t buflen)
	471	{
	472	const unsigned char p, end = (const unsigned char *)buf + buflen;
	473	unsigned int hash = FNV_1_32;
	474
	475	for (p = buf; p < end; p++) {
	476	hash *= FNV_P_32;
	477	hash ^= (unsigned int)*p;
	478	}
	479
	480	return (hash);
	481	}
	482
	483	int nfs_map_name_to_uid(struct nfs4_client clp, const char name, size_t namelen, __u32 *uid)
	484	{
	485	struct idmap *idmap = clp->cl_idmap;
	486
	487	return nfs_idmap_id(idmap, &idmap->idmap_user_hash, name, namelen, uid);
	488	}
	489
	490	int nfs_map_group_to_gid(struct nfs4_client clp, const char name, size_t namelen, __u32 *uid)
	491	{
	492	struct idmap *idmap = clp->cl_idmap;
	493
	494	return nfs_idmap_id(idmap, &idmap->idmap_group_hash, name, namelen, uid);
	495	}
	496
	497	int nfs_map_uid_to_name(struct nfs4_client clp, __u32 uid, char buf)
	498	{
	499	struct idmap *idmap = clp->cl_idmap;
	500
	501	return nfs_idmap_name(idmap, &idmap->idmap_user_hash, uid, buf);
	502	}
	503	int nfs_map_gid_to_group(struct nfs4_client clp, __u32 uid, char buf)
	504	{
	505	struct idmap *idmap = clp->cl_idmap;
	506
	507	return nfs_idmap_name(idmap, &idmap->idmap_group_hash, uid, buf);
	508	}
	509