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/*

 * 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/config.h>

# 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.

 *  Possible future encodings:

 *     1  - 4 byte user specified identifier

 *

 * 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

#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 */

        umode_t                 fh_post_mode;   /* i_mode */

        nlink_t                 fh_post_nlink;  /* i_nlink */

        uid_t                   fh_post_uid;    /* i_uid */

        gid_t                   fh_post_gid;    /* i_gid */

        __u64                   fh_post_size;   /* i_size */

        unsigned long           fh_post_blocks; /* i_blocks */

        unsigned long           fh_post_blksize;/* i_blksize */

        __u32                   fh_post_rdev[2];/* i_rdev */

        struct timespec         fh_post_atime;  /* i_atime */

        struct timespec         fh_post_mtime;  /* i_mtime */

        struct timespec         fh_post_ctime;  /* i_ctime */

#endif /* CONFIG_NFSD_V3 */

} svc_fh;

static inline void mk_fsid_v0(u32 *fsidv, dev_t dev, ino_t ino)

{

        fsidv[0] = htonl((MAJOR(dev)<<16) |

                        MINOR(dev));

        fsidv[1] = ino_t_to_u32(ino);

}

static inline void mk_fsid_v1(u32 *fsidv, u32 fsid)

{

        fsidv[0] = fsid;

}

static inline void mk_fsid_v2(u32 *fsidv, dev_t dev, ino_t ino)

{

        fsidv[0] = htonl(MAJOR(dev));

        fsidv[1] = htonl(MINOR(dev));

        fsidv[2] = ino_t_to_u32(ino);

}

/*

 * Shorthand for dprintk()'s

 */

inline static char * SVCFH_fmt(struct svc_fh *fhp)

{

        struct knfsd_fh *fh = &fhp->fh_handle;

        static char buf[80];

        sprintf(buf, "%d: %08x %08x %08x %08x %08x %08x",

                fh->fh_size,

                fh->fh_base.fh_pad[0],

                fh->fh_base.fh_pad[1],

                fh->fh_base.fh_pad[2],

                fh->fh_base.fh_pad[3],

                fh->fh_base.fh_pad[4],

                fh->fh_base.fh_pad[5]);

        return buf;

}

/*

 * Function prototypes

 */

u32     fh_verify(struct svc_rqst *, struct svc_fh *, int, int);

int     fh_compose(struct svc_fh *, struct svc_export *, struct dentry *, struct svc_fh *);

int     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)

{

        if (src->fh_dentry || src->fh_locked) {

                struct dentry *dentry = src->fh_dentry;

                printk(KERN_ERR "fh_copy: copying %s/%s, already verified!\n",

                        dentry->d_parent->d_name.name, dentry->d_name.name);

        }

        *dst = *src;

        return dst;

}

static __inline__ void

fh_dup2(struct svc_fh *dst, struct svc_fh *src)

{

        fh_put(dst);

        dget(src->fh_dentry);

        *dst = *src;

}

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;

        }

}

/*

 * Fill in the post_op attr for the wcc data

 */

static inline void

fill_post_wcc(struct svc_fh *fhp)

{

        struct inode    *inode = fhp->fh_dentry->d_inode;

        if (fhp->fh_post_saved)

                printk("nfsd: inode locked twice during operation.\n");

        fhp->fh_post_mode       = inode->i_mode;

        fhp->fh_post_nlink      = inode->i_nlink;

        fhp->fh_post_uid        = inode->i_uid;

        fhp->fh_post_gid        = inode->i_gid;

        fhp->fh_post_size       = inode->i_size;

        if (inode->i_blksize) {

                fhp->fh_post_blksize    = inode->i_blksize;

                fhp->fh_post_blocks     = inode->i_blocks;

        } else {

                fhp->fh_post_blksize    = BLOCK_SIZE;

                /* how much do we care for accuracy with MinixFS? */

                fhp->fh_post_blocks     = (inode->i_size+511) >> 9;

        }

        fhp->fh_post_rdev[0]    = htonl((u32)imajor(inode));

        fhp->fh_post_rdev[1]    = htonl((u32)iminor(inode));

        fhp->fh_post_atime      = inode->i_atime;

        fhp->fh_post_mtime      = inode->i_mtime;

        fhp->fh_post_ctime      = inode->i_ctime;

        fhp->fh_post_saved      = 1;

}

#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_sem's at once

 * so, any changes here should be reflected there.

 */

static inline void

fh_lock(struct svc_fh *fhp)

{

        struct dentry   *dentry = fhp->fh_dentry;

        struct inode    *inode;

        dfprintk(FILEOP, "nfsd: fh_lock(%s) locked = %d\n",

                        SVCFH_fmt(fhp), fhp->fh_locked);

        if (!fhp->fh_dentry) {

                printk(KERN_ERR "fh_lock: fh not verified!\n");

                return;

        }

        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;

        down(&inode->i_sem);

        fill_pre_wcc(fhp);

        fhp->fh_locked = 1;

}

/*

 * Unlock a file handle/inode

 */

static inline void

fh_unlock(struct svc_fh *fhp)

{

        if (!fhp->fh_dentry)

                printk(KERN_ERR "fh_unlock: fh not verified!\n");

        if (fhp->fh_locked) {

                fill_post_wcc(fhp);

                up(&fhp->fh_dentry->d_inode->i_sem);

                fhp->fh_locked = 0;

        }

}

#endif /* __KERNEL__ */

#endif /* _LINUX_NFSD_FH_H */