/*
* Copyright (c) 2004 The Regents of the University of Michigan.
* All rights reserved.
*
* Andy Adamson <andros@citi.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/file.h>
#include <linux/namei.h>
#include <linux/crypto.h>
#include <linux/sched.h>
#include "nfsd.h"
#include "state.h"
#include "vfs.h"
#define NFSDDBG_FACILITY NFSDDBG_PROC
/* Globals */
static struct path rec_dir;
static int rec_dir_init = 0;
static int
nfs4_save_creds(const struct cred **original_creds)
{
struct cred *new;
new = prepare_creds();
if (!new)
return -ENOMEM;
new->fsuid = 0;
new->fsgid = 0;
*original_creds = override_creds(new);
put_cred(new);
return 0;
}
static void
nfs4_reset_creds(const struct cred *original)
{
revert_creds(original);
}
static void
md5_to_hex(char *out, char *md5)
{
int i;
for (i=0; i<16; i++) {
unsigned char c = md5[i];
*out++ = '0' + ((c&0xf0)>>4) + (c>=0xa0)*('a'-'9'-1);
*out++ = '0' + (c&0x0f) + ((c&0x0f)>=0x0a)*('a'-'9'-1);
}
*out = '\0';
}
__be32
nfs4_make_rec_clidname(char *dname, struct xdr_netobj *clname)
{
struct xdr_netobj cksum;
struct hash_desc desc;
struct scatterlist sg;
__be32 status = nfserr_resource;
dprintk("NFSD: nfs4_make_rec_clidname for %.*s\n",
clname->len, clname->data);
desc.flags = CRYPTO_TFM_REQ_MAY_SLEEP;
desc.tfm = crypto_alloc_hash("md5", 0, CRYPTO_ALG_ASYNC);
if (IS_ERR(desc.tfm))
goto out_no_tfm;
cksum.len = crypto_hash_digestsize(desc.tfm);
cksum.data = kmalloc(cksum.len, GFP_KERNEL);
if (cksum.data == NULL)
goto out;
sg_init_one(&sg, clname->data, clname->len);
if (crypto_hash_digest(&desc, &sg, sg.length, cksum.data))
goto out;
md5_to_hex(dname, cksum.data);
status = nfs_ok;
out:
kfree(cksum.data);
crypto_free_hash(desc.tfm);
out_no_tfm:
return status;
}
static void
nfsd4_sync_rec_dir(void)
{
vfs_fsync(NULL, rec_dir.dentry, 0);
}
int
nfsd4_create_clid_dir(struct nfs4_client *clp)
{
const struct cred *original_cred;
char *dname = clp->cl_recdir;
struct dentry *dentry;
int status;
dprintk("NFSD: nfsd4_create_clid_dir for \"%s\"\n", dname);
if (!rec_dir_init || clp->cl_firststate)
return 0;
status = nfs4_save_creds(&original_cred);
if (status < 0)
return status;
/* lock the parent */
mutex_lock(&rec_dir.dentry->d_inode->i_mutex);
dentry = lookup_one_len(dname, rec_dir.dentry, HEXDIR_LEN-1);
if (IS_ERR(dentry)) {
status = PTR_ERR(dentry);
goto out_unlock;
}
status = -EEXIST;
if (dentry->d_inode) {
dprintk("NFSD: nfsd4_create_clid_dir: DIRECTORY EXISTS\n");
goto out_put;
}
status = mnt_want_write(rec_dir.mnt);
if (status)
goto out_put;
status = vfs_mkdir(rec_dir.dentry->d_inode, dentry, S_IRWXU);
mnt_drop_write(rec_dir.mnt);
out_put:
dput(dentry);
out_unlock:
mutex_unlock(&rec_dir.dentry->d_inode->i_mutex);
if (status == 0) {
clp->cl_firststate = 1;
nfsd4_sync_rec_dir();
}
nfs4_reset_creds(original_cred);
dprintk("NFSD: nfsd4_create_clid_dir returns %d\n", status);
return status;
}
typedef int (recdir_func)(struct dentry *, struct dentry *);
struct name_list {
char name[HEXDIR_LEN];
struct list_head list;
};
static int
nfsd4_build_namelist(void *arg, const char *name, int namlen,
loff_t offset, u64 ino, unsigned int d_type)
{
struct list_head *names = arg;
struct name_list *entry;
if (namlen != HEXDIR_LEN - 1)
return 0;
entry = kmalloc(sizeof(struct name_list), GFP_KERNEL);
if (entry == NULL)
return -ENOMEM;
memcpy(entry->name, name, HEXDIR_LEN - 1);
entry->name[HEXDIR_LEN - 1] = '\0';
list_add(&entry->list, names);
return 0;
}
static int
nfsd4_list_rec_dir(struct dentry *dir, recdir_func *f)
{
const struct cred *original_cred;
struct file *filp;
LIST_HEAD(names);
struct name_list *entry;
struct dentry *dentry;
int status;
if (!rec_dir_init)
return 0;
status = nfs4_save_creds(&original_cred);
if (status < 0)
return status;
filp = dentry_open(dget(dir), mntget(rec_dir.mnt), O_RDONLY,
current_cred());
status = PTR_ERR(filp);
if (IS_ERR(filp))
goto out;
status = vfs_readdir(filp, nfsd4_build_namelist, &names);
fput(filp);
mutex_lock_nested(&dir->d_inode->i_mutex, I_MUTEX_PARENT);
while (!list_empty(&names)) {
entry = list_entry(names.next, struct name_list, list);
dentry = lookup_one_len(entry->name, dir, HEXDIR_LEN-1);
if (IS_ERR(dentry)) {
status = PTR_ERR(dentry);
break;
}
status = f(dir, dentry);
dput(dentry);
if (status)
break;
list_del(&entry->list);
kfree(entry);
}
mutex_unlock(&dir->d_inode->i_mutex);
out:
while (!list_empty(&names)) {
entry = list_entry(names.next, struct name_list, list);
list_del(&entry->list);
kfree(entry);
}
nfs4_reset_creds(original_cred);
return status;
}
static int
nfsd4_unlink_clid_dir(char *name, int namlen)
{
struct dentry *dentry;
int status;
dprintk("NFSD: nfsd4_unlink_clid_dir. name %.*s\n", namlen, name);
mutex_lock_nested(&rec_dir.dentry->d_inode->i_mutex, I_MUTEX_PARENT);
dentry = lookup_one_len(name, rec_dir.dentry, namlen);
if (IS_ERR(dentry)) {
status = PTR_ERR(dentry);
goto out_unlock;
}
status = -ENOENT;
if (!dentry->d_inode)
goto out;
status = vfs_rmdir(rec_dir.dentry->d_inode, dentry);
out:
dput(dentry);
out_unlock:
mutex_unlock(&rec_dir.dentry->d_inode->i_mutex);
return status;
}
void
nfsd4_remove_clid_dir(struct nfs4_client *clp)
{
const struct cred *original_cred;
int status;
if (!rec_dir_init || !clp->cl_firststate)
return;
status = mnt_want_write(rec_dir.mnt);
if (status)
goto out;
clp->cl_firststate = 0;
status = nfs4_save_creds(&original_cred);
if (status < 0)
goto out;
status = nfsd4_unlink_clid_dir(clp->cl_recdir, HEXDIR_LEN-1);
nfs4_reset_creds(original_cred);
if (status == 0)
nfsd4_sync_rec_dir();
mnt_drop_write(rec_dir.mnt);
out:
if (status)
printk("NFSD: Failed to remove expired client state directory"
" %.*s\n", HEXDIR_LEN, clp->cl_recdir);
return;
}
static int
purge_old(struct dentry *parent, struct dentry *child)
{
int status;
/* note: we currently use this path only for minorversion 0 */
if (nfs4_has_reclaimed_state(child->d_name.name, false))
return 0;
status = vfs_rmdir(parent->d_inode, child);
if (status)
printk("failed to remove client recovery directory %s\n",
child->d_name.name);
/* Keep trying, success or failure: */
return 0;
}
void
nfsd4_recdir_purge_old(void) {
int status;
if (!rec_dir_init)
return;
status = mnt_want_write(rec_dir.mnt);
if (status)
goto out;
status = nfsd4_list_rec_dir(rec_dir.dentry, purge_old);
if (status == 0)
nfsd4_sync_rec_dir();
mnt_drop_write(rec_dir.mnt);
out:
if (status)
printk("nfsd4: failed to purge old clients from recovery"
" directory %s\n", rec_dir.dentry->d_name.name);
}
static int
load_recdir(struct dentry *parent, struct dentry *child)
{
if (child->d_name.len != HEXDIR_LEN - 1) {
printk("nfsd4: illegal name %s in recovery directory\n",
child->d_name.name);
/* Keep trying; maybe the others are OK: */
return 0;
}
nfs4_client_to_reclaim(child->d_name.name);
return 0;
}
int
nfsd4_recdir_load(void) {
int status;
status = nfsd4_list_rec_dir(rec_dir.dentry, load_recdir);
if (status)
printk("nfsd4: failed loading clients from recovery"
" directory %s\n", rec_dir.dentry->d_name.name);
return status;
}
/*
* Hold reference to the recovery directory.
*/
void
nfsd4_init_recdir(char *rec_dirname)
{
const struct cred *original_cred;
int status;
printk("NFSD: Using %s as the NFSv4 state recovery directory\n",
rec_dirname);
BUG_ON(rec_dir_init);
status = nfs4_save_creds(&original_cred);
if (status < 0) {
printk("NFSD: Unable to change credentials to find recovery"
" directory: error %d\n",
status);
return;
}
status = kern_path(rec_dirname, LOOKUP_FOLLOW | LOOKUP_DIRECTORY,
&rec_dir);
if (status)
printk("NFSD: unable to find recovery directory %s\n",
rec_dirname);
if (!status)
rec_dir_init = 1;
nfs4_reset_creds(original_cred);
}
void
nfsd4_shutdown_recdir(void)
{
if (!rec_dir_init)
return;
rec_dir_init = 0;
path_put(&rec_dir);
}
