kernel-ark/include/linux/nfsd/export.h

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/*
* include/linux/nfsd/export.h
*
* Public declarations for NFS exports. The definitions for the
* syscall interface are in nfsctl.h
*
* Copyright (C) 1995-1997 Olaf Kirch <okir@monad.swb.de>
*/
#ifndef NFSD_EXPORT_H
#define NFSD_EXPORT_H
# include <linux/types.h>
#ifdef __KERNEL__
# include <linux/nfsd/nfsfh.h>
#endif
/*
* Important limits for the exports stuff.
*/
#define NFSCLNT_IDMAX 1024
#define NFSCLNT_ADDRMAX 16
#define NFSCLNT_KEYMAX 32
/*
* Export flags.
*/
#define NFSEXP_READONLY 0x0001
#define NFSEXP_INSECURE_PORT 0x0002
#define NFSEXP_ROOTSQUASH 0x0004
#define NFSEXP_ALLSQUASH 0x0008
#define NFSEXP_ASYNC 0x0010
#define NFSEXP_GATHERED_WRITES 0x0020
/* 40 80 100 currently unused */
#define NFSEXP_NOHIDE 0x0200
#define NFSEXP_NOSUBTREECHECK 0x0400
#define NFSEXP_NOAUTHNLM 0x0800 /* Don't authenticate NLM requests - just trust */
#define NFSEXP_MSNFS 0x1000 /* do silly things that MS clients expect; no longer supported */
#define NFSEXP_FSID 0x2000
#define NFSEXP_CROSSMOUNT 0x4000
#define NFSEXP_NOACL 0x8000 /* reserved for possible ACL related use */
nfsd: introduce export flag for v4 pseudoroot NFSv4 differs from v2 and v3 in that it presents a single unified filesystem tree, whereas v2 and v3 exported multiple filesystem (whose roots could be found using a separate mount protocol). Our original NFSv4 server implementation asked the administrator to designate a single filesystem as the NFSv4 root, then to mount filesystems they wished to export underneath. (Often using bind mounts of already-existing filesystems.) This was conceptually simple, and allowed easy implementation, but created a serious obstacle to upgrading between v2/v3: since the paths to v4 filesystems were different, administrators would have to adjust all the paths in client-side mount commands when switching to v4. Various workarounds are possible. For example, the administrator could export "/" and designate it as the v4 root. However, the security risks of that approach are obvious, and in any case we shouldn't be requiring the administrator to take extra steps to fix this problem; instead, the server should present consistent paths across different versions by default. These patches take a modified version of that approach: we provide a new export option which exports only a subset of a filesystem. With this flag, it becomes safe for mountd to export "/" by default, with no need for additional configuration. We begin just by defining the new flag. Signed-off-by: Steve Dickson <steved@redhat.com> Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
2009-09-09 18:58:22 +00:00
/*
* The NFSEXP_V4ROOT flag causes the kernel to give access only to NFSv4
* clients, and only to the single directory that is the root of the
* export; further lookup and readdir operations are treated as if every
* subdirectory was a mountpoint, and ignored if they are not themselves
* exported. This is used by nfsd and mountd to construct the NFSv4
* pseudofilesystem, which provides access only to paths leading to each
* exported filesystem.
*/
#define NFSEXP_V4ROOT 0x10000
/* All flags that we claim to support. (Note we don't support NOACL.) */
#define NFSEXP_ALLFLAGS 0x17E3F
/* The flags that may vary depending on security flavor: */
#define NFSEXP_SECINFO_FLAGS (NFSEXP_READONLY | NFSEXP_ROOTSQUASH \
| NFSEXP_ALLSQUASH \
| NFSEXP_INSECURE_PORT)
#ifdef __KERNEL__
/*
* FS Locations
*/
#define MAX_FS_LOCATIONS 128
struct nfsd4_fs_location {
char *hosts; /* colon separated list of hosts */
char *path; /* slash separated list of path components */
};
struct nfsd4_fs_locations {
uint32_t locations_count;
struct nfsd4_fs_location *locations;
/* If we're not actually serving this data ourselves (only providing a
* list of replicas that do serve it) then we set "migrated": */
int migrated;
};
/*
* We keep an array of pseudoflavors with the export, in order from most
* to least preferred. For the foreseeable future, we don't expect more
* than the eight pseudoflavors null, unix, krb5, krb5i, krb5p, skpm3,
* spkm3i, and spkm3p (and using all 8 at once should be rare).
*/
#define MAX_SECINFO_LIST 8
struct exp_flavor_info {
u32 pseudoflavor;
u32 flags;
};
struct svc_export {
struct cache_head h;
struct auth_domain * ex_client;
int ex_flags;
struct path ex_path;
char *ex_pathname;
uid_t ex_anon_uid;
gid_t ex_anon_gid;
int ex_fsid;
unsigned char * ex_uuid; /* 16 byte fsid */
struct nfsd4_fs_locations ex_fslocs;
int ex_nflavors;
struct exp_flavor_info ex_flavors[MAX_SECINFO_LIST];
};
/* an "export key" (expkey) maps a filehandlefragement to an
* svc_export for a given client. There can be several per export,
* for the different fsid types.
*/
struct svc_expkey {
struct cache_head h;
struct auth_domain * ek_client;
int ek_fsidtype;
u32 ek_fsid[6];
struct path ek_path;
};
#define EX_ISSYNC(exp) (!((exp)->ex_flags & NFSEXP_ASYNC))
#define EX_NOHIDE(exp) ((exp)->ex_flags & NFSEXP_NOHIDE)
#define EX_WGATHER(exp) ((exp)->ex_flags & NFSEXP_GATHERED_WRITES)
int nfsexp_flags(struct svc_rqst *rqstp, struct svc_export *exp);
__be32 check_nfsd_access(struct svc_export *exp, struct svc_rqst *rqstp);
/*
* Function declarations
*/
int nfsd_export_init(void);
void nfsd_export_shutdown(void);
void nfsd_export_flush(void);
struct svc_export * rqst_exp_get_by_name(struct svc_rqst *,
struct path *);
struct svc_export * rqst_exp_parent(struct svc_rqst *,
struct path *);
int exp_rootfh(struct auth_domain *,
char *path, struct knfsd_fh *, int maxsize);
__be32 exp_pseudoroot(struct svc_rqst *, struct svc_fh *);
__be32 nfserrno(int errno);
extern struct cache_detail svc_export_cache;
static inline void exp_put(struct svc_export *exp)
{
cache_put(&exp->h, &svc_export_cache);
}
static inline void exp_get(struct svc_export *exp)
{
cache_get(&exp->h);
}
struct svc_export * rqst_exp_find(struct svc_rqst *, int, u32 *);
#endif /* __KERNEL__ */
#endif /* NFSD_EXPORT_H */