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DEFINITIONS
This source file includes following definitions.
- ino_t_to_u32
- u32_to_ino_t
- mk_fsid
- key_len
- fh_copy
- fh_init
- fill_pre_wcc
- fh_lock_nested
- fh_lock
- fh_unlock
/*
* include/linux/nfsd/nfsfh.h
*
* This file describes the layout of the file handles as passed
* over the wire.
*
* Earlier versions of knfsd used to sign file handles using keyed MD5
* or SHA. I've removed this code, because it doesn't give you more
* security than blocking external access to port 2049 on your firewall.
*
* Copyright (C) 1995, 1996, 1997 Olaf Kirch <okir@monad.swb.de>
*/
#ifndef _LINUX_NFSD_FH_H
#define _LINUX_NFSD_FH_H
#include <asm/types.h>
#ifdef __KERNEL__
# include <linux/types.h>
# include <linux/string.h>
# include <linux/fs.h>
#endif
#include <linux/nfsd/const.h>
#include <linux/nfsd/debug.h>
/*
* This is the old "dentry style" Linux NFSv2 file handle.
*
* The xino and xdev fields are currently used to transport the
* ino/dev of the exported inode.
*/
struct nfs_fhbase_old {
__u32 fb_dcookie; /* dentry cookie - always 0xfeebbaca */
__u32 fb_ino; /* our inode number */
__u32 fb_dirino; /* dir inode number, 0 for directories */
__u32 fb_dev; /* our device */
__u32 fb_xdev;
__u32 fb_xino;
__u32 fb_generation;
};
/*
* This is the new flexible, extensible style NFSv2/v3 file handle.
* by Neil Brown <neilb@cse.unsw.edu.au> - March 2000
*
* The file handle is seens as a list of 4byte words.
* The first word contains a version number (1) and four descriptor bytes
* that tell how the remaining 3 variable length fields should be handled.
* These three bytes are auth_type, fsid_type and fileid_type.
*
* All 4byte values are in host-byte-order.
*
* The auth_type field specifies how the filehandle can be authenticated
* This might allow a file to be confirmed to be in a writable part of a
* filetree without checking the path from it upto the root.
* Current values:
* 0 - No authentication. fb_auth is 0 bytes long
* Possible future values:
* 1 - 4 bytes taken from MD5 hash of the remainer of the file handle
* prefixed by a secret and with the important export flags.
*
* The fsid_type identifies how the filesystem (or export point) is
* encoded.
* Current values:
* 0 - 4 byte device id (ms-2-bytes major, ls-2-bytes minor), 4byte inode number
* NOTE: we cannot use the kdev_t device id value, because kdev_t.h
* says we mustn't. We must break it up and reassemble.
* 1 - 4 byte user specified identifier
* 2 - 4 byte major, 4 byte minor, 4 byte inode number - DEPRECATED
* 3 - 4 byte device id, encoded for user-space, 4 byte inode number
*
* The fileid_type identified how the file within the filesystem is encoded.
* This is (will be) passed to, and set by, the underlying filesystem if it supports
* filehandle operations. The filesystem must not use the value '0' or '0xff' and may
* only use the values 1 and 2 as defined below:
* Current values:
* 0 - The root, or export point, of the filesystem. fb_fileid is 0 bytes.
* 1 - 32bit inode number, 32 bit generation number.
* 2 - 32bit inode number, 32 bit generation number, 32 bit parent directory inode number.
*
*/
struct nfs_fhbase_new {
__u8 fb_version; /* == 1, even => nfs_fhbase_old */
__u8 fb_auth_type;
__u8 fb_fsid_type;
__u8 fb_fileid_type;
__u32 fb_auth[1];
/* __u32 fb_fsid[0]; floating */
/* __u32 fb_fileid[0]; floating */
};
struct knfsd_fh {
unsigned int fh_size; /* significant for NFSv3.
* Points to the current size while building
* a new file handle
*/
union {
struct nfs_fhbase_old fh_old;
__u32 fh_pad[NFS4_FHSIZE/4];
struct nfs_fhbase_new fh_new;
} fh_base;
};
#define ofh_dcookie fh_base.fh_old.fb_dcookie
#define ofh_ino fh_base.fh_old.fb_ino
#define ofh_dirino fh_base.fh_old.fb_dirino
#define ofh_dev fh_base.fh_old.fb_dev
#define ofh_xdev fh_base.fh_old.fb_xdev
#define ofh_xino fh_base.fh_old.fb_xino
#define ofh_generation fh_base.fh_old.fb_generation
#define fh_version fh_base.fh_new.fb_version
#define fh_fsid_type fh_base.fh_new.fb_fsid_type
#define fh_auth_type fh_base.fh_new.fb_auth_type
#define fh_fileid_type fh_base.fh_new.fb_fileid_type
#define fh_auth fh_base.fh_new.fb_auth
#define fh_fsid fh_base.fh_new.fb_auth
#ifdef __KERNEL__
static inline __u32 ino_t_to_u32(ino_t ino)
{
return (__u32) ino;
}
static inline ino_t u32_to_ino_t(__u32 uino)
{
return (ino_t) uino;
}
/*
* This is the internal representation of an NFS handle used in knfsd.
* pre_mtime/post_version will be used to support wcc_attr's in NFSv3.
*/
typedef struct svc_fh {
struct knfsd_fh fh_handle; /* FH data */
struct dentry * fh_dentry; /* validated dentry */
struct svc_export * fh_export; /* export pointer */
int fh_maxsize; /* max size for fh_handle */
unsigned char fh_locked; /* inode locked by us */
#ifdef CONFIG_NFSD_V3
unsigned char fh_post_saved; /* post-op attrs saved */
unsigned char fh_pre_saved; /* pre-op attrs saved */
/* Pre-op attributes saved during fh_lock */
__u64 fh_pre_size; /* size before operation */
struct timespec fh_pre_mtime; /* mtime before oper */
struct timespec fh_pre_ctime; /* ctime before oper */
/* Post-op attributes saved in fh_unlock */
struct kstat fh_post_attr; /* full attrs after operation */
#endif /* CONFIG_NFSD_V3 */
} svc_fh;
enum nfsd_fsid {
FSID_DEV = 0,
FSID_NUM,
FSID_MAJOR_MINOR,
FSID_ENCODE_DEV,
FSID_UUID4_INUM,
FSID_UUID8,
FSID_UUID16,
FSID_UUID16_INUM,
};
enum fsid_source {
FSIDSOURCE_DEV,
FSIDSOURCE_FSID,
FSIDSOURCE_UUID,
};
extern enum fsid_source fsid_source(struct svc_fh *fhp);
/* This might look a little large to "inline" but in all calls except
* one, 'vers' is constant so moste of the function disappears.
*/
static inline void mk_fsid(int vers, u32 *fsidv, dev_t dev, ino_t ino,
u32 fsid, unsigned char *uuid)
{
u32 *up;
switch(vers) {
case FSID_DEV:
fsidv[0] = htonl((MAJOR(dev)<<16) |
MINOR(dev));
fsidv[1] = ino_t_to_u32(ino);
break;
case FSID_NUM:
fsidv[0] = fsid;
break;
case FSID_MAJOR_MINOR:
fsidv[0] = htonl(MAJOR(dev));
fsidv[1] = htonl(MINOR(dev));
fsidv[2] = ino_t_to_u32(ino);
break;
case FSID_ENCODE_DEV:
fsidv[0] = new_encode_dev(dev);
fsidv[1] = ino_t_to_u32(ino);
break;
case FSID_UUID4_INUM:
/* 4 byte fsid and inode number */
up = (u32*)uuid;
fsidv[0] = ino_t_to_u32(ino);
fsidv[1] = up[0] ^ up[1] ^ up[2] ^ up[3];
break;
case FSID_UUID8:
/* 8 byte fsid */
up = (u32*)uuid;
fsidv[0] = up[0] ^ up[2];
fsidv[1] = up[1] ^ up[3];
break;
case FSID_UUID16:
/* 16 byte fsid - NFSv3+ only */
memcpy(fsidv, uuid, 16);
break;
case FSID_UUID16_INUM:
/* 8 byte inode and 16 byte fsid */
*(u64*)fsidv = (u64)ino;
memcpy(fsidv+2, uuid, 16);
break;
default: BUG();
}
}
static inline int key_len(int type)
{
switch(type) {
case FSID_DEV: return 8;
case FSID_NUM: return 4;
case FSID_MAJOR_MINOR: return 12;
case FSID_ENCODE_DEV: return 8;
case FSID_UUID4_INUM: return 8;
case FSID_UUID8: return 8;
case FSID_UUID16: return 16;
case FSID_UUID16_INUM: return 24;
default: return 0;
}
}
/*
* Shorthand for dprintk()'s
*/
extern char * SVCFH_fmt(struct svc_fh *fhp);
/*
* Function prototypes
*/
__be32 fh_verify(struct svc_rqst *, struct svc_fh *, int, int);
__be32 fh_compose(struct svc_fh *, struct svc_export *, struct dentry *, struct svc_fh *);
__be32 fh_update(struct svc_fh *);
void fh_put(struct svc_fh *);
static __inline__ struct svc_fh *
fh_copy(struct svc_fh *dst, struct svc_fh *src)
{
WARN_ON(src->fh_dentry || src->fh_locked);
*dst = *src;
return dst;
}
static __inline__ struct svc_fh *
fh_init(struct svc_fh *fhp, int maxsize)
{
memset(fhp, 0, sizeof(*fhp));
fhp->fh_maxsize = maxsize;
return fhp;
}
#ifdef CONFIG_NFSD_V3
/*
* Fill in the pre_op attr for the wcc data
*/
static inline void
fill_pre_wcc(struct svc_fh *fhp)
{
struct inode *inode;
inode = fhp->fh_dentry->d_inode;
if (!fhp->fh_pre_saved) {
fhp->fh_pre_mtime = inode->i_mtime;
fhp->fh_pre_ctime = inode->i_ctime;
fhp->fh_pre_size = inode->i_size;
fhp->fh_pre_saved = 1;
}
}
extern void fill_post_wcc(struct svc_fh *);
#else
#define fill_pre_wcc(ignored)
#define fill_post_wcc(notused)
#endif /* CONFIG_NFSD_V3 */
/*
* Lock a file handle/inode
* NOTE: both fh_lock and fh_unlock are done "by hand" in
* vfs.c:nfsd_rename as it needs to grab 2 i_mutex's at once
* so, any changes here should be reflected there.
*/
static inline void
fh_lock_nested(struct svc_fh *fhp, unsigned int subclass)
{
struct dentry *dentry = fhp->fh_dentry;
struct inode *inode;
dfprintk(FILEOP, "nfsd: fh_lock(%s) locked = %d\n",
SVCFH_fmt(fhp), fhp->fh_locked);
BUG_ON(!dentry);
if (fhp->fh_locked) {
printk(KERN_WARNING "fh_lock: %s/%s already locked!\n",
dentry->d_parent->d_name.name, dentry->d_name.name);
return;
}
inode = dentry->d_inode;
mutex_lock_nested(&inode->i_mutex, subclass);
fill_pre_wcc(fhp);
fhp->fh_locked = 1;
}
static inline void
fh_lock(struct svc_fh *fhp)
{
fh_lock_nested(fhp, I_MUTEX_NORMAL);
}
/*
* Unlock a file handle/inode
*/
static inline void
fh_unlock(struct svc_fh *fhp)
{
BUG_ON(!fhp->fh_dentry);
if (fhp->fh_locked) {
fill_post_wcc(fhp);
mutex_unlock(&fhp->fh_dentry->d_inode->i_mutex);
fhp->fh_locked = 0;
}
}
#endif /* __KERNEL__ */
#endif /* _LINUX_NFSD_FH_H */