include/linux/nfsd/nfsfh.h

   1 /*
   2  * include/linux/nfsd/nfsfh.h
   3  *
   4  * This file describes the layout of the file handles as passed
   5  * over the wire.
   6  *
   7  * Earlier versions of knfsd used to sign file handles using keyed MD5
   8  * or SHA. I've removed this code, because it doesn't give you more
   9  * security than blocking external access to port 2049 on your firewall.
  10  *
  11  * Copyright (C) 1995, 1996, 1997 Olaf Kirch <okir@monad.swb.de>
  12  */
  13
  14 #ifndef NFSD_FH_H
  15 #define NFSD_FH_H
  16
  17 #include <linux/types.h>
  18 #include <linux/string.h>
  19 #include <linux/fs.h>
  20 #include <linux/nfsd/const.h>
  21 #include <linux/nfsd/debug.h>
  22
  23 /*
  24  * This is the new "dentry style" Linux NFSv2 file handle.
  25  *
  26  * The xino and xdev fields are currently used to transport the
  27  * ino/dev of the exported inode.
  28  */
  29 struct nfs_fhbase {
  30         struct dentry *         fb_dentry;      /* dentry cookie */
  31         ino_t                   fb_ino;         /* our inode number */
  32         ino_t                   fb_dirino;      /* dir inode number */
  33         dev_t                   fb_dev;         /* our device */
  34         dev_t                   fb_xdev;
  35         ino_t                   fb_xino;
  36 };
  37
  38 #define NFS_FH_PADDING          (NFS_FHSIZE - sizeof(struct nfs_fhbase))
  39 struct knfs_fh {
  40         struct nfs_fhbase       fh_base;
  41         __u8                    fh_cookie[NFS_FH_PADDING];
  42 };
  43
  44 #define fh_dcookie              fh_base.fb_dentry
  45 #define fh_ino                  fh_base.fb_ino
  46 #define fh_dirino               fh_base.fb_dirino
  47 #define fh_dev                  fh_base.fb_dev
  48 #define fh_xdev                 fh_base.fb_xdev
  49 #define fh_xino                 fh_base.fb_xino
  50
  51 #ifdef __KERNEL__
  52
  53 /*
  54  * This is the internal representation of an NFS handle used in knfsd.
  55  * pre_mtime/post_version will be used to support wcc_attr's in NFSv3.
  56  */
  57 typedef struct svc_fh {
  58         struct knfs_fh          fh_handle;      /* FH data */
  59         struct dentry *         fh_dentry;      /* validated dentry */
  60         struct svc_export *     fh_export;      /* export pointer */
  61         size_t                  fh_pre_size;    /* size before operation */
  62         time_t                  fh_pre_mtime;   /* mtime before oper */
  63         time_t                  fh_pre_ctime;   /* ctime before oper */
  64         unsigned long           fh_post_version;/* inode version after oper */
  65         unsigned char           fh_locked;      /* inode locked by us */
  66         unsigned char           fh_dverified;   /* dentry has been checked */
  67 } svc_fh;
  68
  69 /*
  70  * Shorthand for dprintk()'s
  71  */
  72 #define SVCFH_DENTRY(f)         ((f)->fh_dentry)
  73 #define SVCFH_INO(f)            ((f)->fh_handle.fh_ino)
  74 #define SVCFH_DEV(f)            ((f)->fh_handle.fh_dev)
  75
  76 /*
  77  * Function prototypes
  78  */
  79 u32     fh_verify(struct svc_rqst *, struct svc_fh *, int, int);
  80 void    fh_compose(struct svc_fh *, struct svc_export *, struct dentry *);
  81 void    fh_update(struct svc_fh *);
  82 void    fh_put(struct svc_fh *);
  83 void    nfsd_fh_flush(dev_t);
  84 void    nfsd_fh_init(void);
  85 void    nfsd_fh_free(void);
  86
  87 static __inline__ struct svc_fh *
  88 fh_copy(struct svc_fh *dst, struct svc_fh *src)
  89 {
  90         if (src->fh_dverified) {
  91                 struct dentry *dentry = src->fh_dentry;
  92                 printk("fh_copy: copying %s/%s, already verified!\n",
  93                         dentry->d_parent->d_name.name, dentry->d_name.name);
  94         }
  95
  96         *dst = *src;
  97         return dst;
  98 }
  99
 100 static __inline__ struct svc_fh *
 101 fh_init(struct svc_fh *fhp)
 102 {
 103         memset(fhp, 0, sizeof(*fhp));
 104         return fhp;
 105 }
 106
 107 /*
 108  * Lock a file handle/inode
 109  */
 110 static inline void
 111 fh_lock(struct svc_fh *fhp)
 112 {
 113         struct inode    *inode = fhp->fh_dentry->d_inode;
 114
 115         /*
 116         dfprintk(FILEOP, "nfsd: fh_lock(%x/%ld) locked = %d\n",
 117                         SVCFH_DEV(fhp), SVCFH_INO(fhp), fhp->fh_locked);
 118          */
 119         if (fhp->fh_locked) {
 120                 printk(KERN_WARNING "fh_lock: %s/%s already locked!\n",
 121                         fhp->fh_dentry->d_parent->d_name.name,
 122                         fhp->fh_dentry->d_name.name);
 123                 return;
 124         }
 125         down(&inode->i_sem);
 126         if (!fhp->fh_pre_mtime)
 127                 fhp->fh_pre_mtime = inode->i_mtime;
 128         fhp->fh_locked = 1;
 129 }
 130
 131 /*
 132  * Unlock a file handle/inode
 133  */
 134 static inline void
 135 fh_unlock(struct svc_fh *fhp)
 136 {
 137         if (fhp->fh_locked) {
 138                 struct inode *inode = fhp->fh_dentry->d_inode;
 139                 if (!fhp->fh_post_version)
 140                         fhp->fh_post_version = inode->i_version;
 141                 fhp->fh_locked = 0;
 142                 up(&inode->i_sem);
 143         }
 144 }
 145
 146 /*
 147  * Release an inode
 148  */
 149 #if 0
 150 #define fh_put(fhp)     __fh_put(fhp, __FILE__, __LINE__)
 151
 152 static inline void
 153 __fh_put(struct svc_fh *fhp, char *file, int line)
 154 {
 155         struct dentry   *dentry;
 156
 157         if (!fhp->fh_dverified)
 158                 return;
 159
 160         dentry = fhp->fh_dentry;
 161         if (!dentry->d_count) {
 162                 printk("nfsd: trying to free free dentry in %s:%d\n"
 163                        "      file %s/%s\n",
 164                        file, line,
 165                        dentry->d_parent->d_name.name, dentry->d_name.name);
 166         } else {
 167                 fh_unlock(fhp);
 168                 fhp->fh_dverified = 0;
 169                 dput(dentry);
 170         }
 171 }
 172 #endif
 173
 174 #endif /* __KERNEL__ */
 175
 176 #endif /* NFSD_FH_H */