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Diffstat (limited to 'include/linux/nfsd/nfsfh.h')
| -rw-r--r-- | include/linux/nfsd/nfsfh.h | 355 |
1 files changed, 355 insertions, 0 deletions
diff --git a/include/linux/nfsd/nfsfh.h b/include/linux/nfsd/nfsfh.h new file mode 100644 index 0000000..d1941cb --- /dev/null +++ b/include/linux/nfsd/nfsfh.h @@ -0,0 +1,355 @@ +/* + * 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 */ |
