[linux-2.6-block.git] / fs / nfsd / nfsfh.c

/*
 * linux/fs/nfsd/nfsfh.c
 *
 * NFS server file handle treatment.
 *
 * Copyright (C) 1995, 1996 Olaf Kirch <okir@monad.swb.de>
 * Portions Copyright (C) 1999 G. Allen Morris III <gam3@acm.org>
 * Extensive rewrite by Neil Brown <neilb@cse.unsw.edu.au> Southern-Spring 1999
 * ... and again Southern-Winter 2001 to support export_operations
 */

#include <linux/slab.h>
#include <linux/fs.h>
#include <linux/unistd.h>
#include <linux/string.h>
#include <linux/stat.h>
#include <linux/dcache.h>
#include <linux/exportfs.h>
#include <linux/mount.h>

#include <linux/sunrpc/clnt.h>
#include <linux/sunrpc/svc.h>
#include <linux/sunrpc/svcauth_gss.h>
#include <linux/nfsd/nfsd.h>
#include "auth.h"

#define NFSDDBG_FACILITY		NFSDDBG_FH


static int nfsd_nr_verified;
static int nfsd_nr_put;

/*
 * our acceptability function.
 * if NOSUBTREECHECK, accept anything
 * if not, require that we can walk up to exp->ex_dentry
 * doing some checks on the 'x' bits
 */
static int nfsd_acceptable(void *expv, struct dentry *dentry)
{
	struct svc_export *exp = expv;
	int rv;
	struct dentry *tdentry;
	struct dentry *parent;

	if (exp->ex_flags & NFSEXP_NOSUBTREECHECK)
		return 1;

	tdentry = dget(dentry);
	while (tdentry != exp->ex_path.dentry && !IS_ROOT(tdentry)) {
		/* make sure parents give x permission to user */
		int err;
		parent = dget_parent(tdentry);
		err = permission(parent->d_inode, MAY_EXEC, NULL);
		if (err < 0) {
			dput(parent);
			break;
		}
		dput(tdentry);
		tdentry = parent;
	}
	if (tdentry != exp->ex_path.dentry)
		dprintk("nfsd_acceptable failed at %p %s\n", tdentry, tdentry->d_name.name);
	rv = (tdentry == exp->ex_path.dentry);
	dput(tdentry);
	return rv;
}

/* Type check. The correct error return for type mismatches does not seem to be
 * generally agreed upon. SunOS seems to use EISDIR if file isn't S_IFREG; a
 * comment in the NFSv3 spec says this is incorrect (implementation notes for
 * the write call).
 */
static inline __be32
nfsd_mode_check(struct svc_rqst *rqstp, umode_t mode, int type)
{
	/* Type can be negative when creating hardlinks - not to a dir */
	if (type > 0 && (mode & S_IFMT) != type) {
		if (rqstp->rq_vers == 4 && (mode & S_IFMT) == S_IFLNK)
			return nfserr_symlink;
		else if (type == S_IFDIR)
			return nfserr_notdir;
		else if ((mode & S_IFMT) == S_IFDIR)
			return nfserr_isdir;
		else
			return nfserr_inval;
	}
	if (type < 0 && (mode & S_IFMT) == -type) {
		if (rqstp->rq_vers == 4 && (mode & S_IFMT) == S_IFLNK)
			return nfserr_symlink;
		else if (type == -S_IFDIR)
			return nfserr_isdir;
		else
			return nfserr_notdir;
	}
	return 0;
}

static __be32 nfsd_setuser_and_check_port(struct svc_rqst *rqstp,
					  struct svc_export *exp)
{
	/* Check if the request originated from a secure port. */
	if (!rqstp->rq_secure && EX_SECURE(exp)) {
		char buf[RPC_MAX_ADDRBUFLEN];
		dprintk(KERN_WARNING
		       "nfsd: request from insecure port %s!\n",
		       svc_print_addr(rqstp, buf, sizeof(buf)));
		return nfserr_perm;
	}

	/* Set user creds for this exportpoint */
	return nfserrno(nfsd_setuser(rqstp, exp));
}

/*
 * Perform sanity checks on the dentry in a client's file handle.
 *
 * Note that the file handle dentry may need to be freed even after
 * an error return.
 *
 * This is only called at the start of an nfsproc call, so fhp points to
 * a svc_fh which is all 0 except for the over-the-wire file handle.
 */
__be32
fh_verify(struct svc_rqst *rqstp, struct svc_fh *fhp, int type, int access)
{
	struct knfsd_fh	*fh = &fhp->fh_handle;
	struct svc_export *exp = NULL;
	struct dentry	*dentry;
	__be32		error = 0;

	dprintk("nfsd: fh_verify(%s)\n", SVCFH_fmt(fhp));

	if (!fhp->fh_dentry) {
		struct fid *fid = NULL, sfid;
		int fileid_type;
		int data_left = fh->fh_size/4;

		error = nfserr_stale;
		if (rqstp->rq_vers > 2)
			error = nfserr_badhandle;
		if (rqstp->rq_vers == 4 && fh->fh_size == 0)
			return nfserr_nofilehandle;

		if (fh->fh_version == 1) {
			int len;
			if (--data_left<0) goto out;
			switch (fh->fh_auth_type) {
			case 0: break;
			default: goto out;
			}
			len = key_len(fh->fh_fsid_type) / 4;
			if (len == 0) goto out;
			if  (fh->fh_fsid_type == FSID_MAJOR_MINOR) {
				/* deprecated, convert to type 3 */
				len = key_len(FSID_ENCODE_DEV)/4;
				fh->fh_fsid_type = FSID_ENCODE_DEV;
				fh->fh_fsid[0] = new_encode_dev(MKDEV(ntohl(fh->fh_fsid[0]), ntohl(fh->fh_fsid[1])));
				fh->fh_fsid[1] = fh->fh_fsid[2];
			}
			if ((data_left -= len)<0) goto out;
			exp = rqst_exp_find(rqstp, fh->fh_fsid_type,
					    fh->fh_auth);
			fid = (struct fid *)(fh->fh_auth + len);
		} else {
			__u32 tfh[2];
			dev_t xdev;
			ino_t xino;
			if (fh->fh_size != NFS_FHSIZE)
				goto out;
			/* assume old filehandle format */
			xdev = old_decode_dev(fh->ofh_xdev);
			xino = u32_to_ino_t(fh->ofh_xino);
			mk_fsid(FSID_DEV, tfh, xdev, xino, 0, NULL);
			exp = rqst_exp_find(rqstp, FSID_DEV, tfh);
		}

		error = nfserr_stale;
		if (PTR_ERR(exp) == -ENOENT)
			goto out;

		if (IS_ERR(exp)) {
			error = nfserrno(PTR_ERR(exp));
			goto out;
		}

		error = nfsd_setuser_and_check_port(rqstp, exp);
		if (error)
			goto out;

		/*
		 * Look up the dentry using the NFS file handle.
		 */
		error = nfserr_stale;
		if (rqstp->rq_vers > 2)
			error = nfserr_badhandle;

		if (fh->fh_version != 1) {
			sfid.i32.ino = fh->ofh_ino;
			sfid.i32.gen = fh->ofh_generation;
			sfid.i32.parent_ino = fh->ofh_dirino;
			fid = &sfid;
			data_left = 3;
			if (fh->ofh_dirino == 0)
				fileid_type = FILEID_INO32_GEN;
			else
				fileid_type = FILEID_INO32_GEN_PARENT;
		} else
			fileid_type = fh->fh_fileid_type;

		if (fileid_type == FILEID_ROOT)
			dentry = dget(exp->ex_path.dentry);
		else {
			dentry = exportfs_decode_fh(exp->ex_path.mnt, fid,
					data_left, fileid_type,
					nfsd_acceptable, exp);
		}
		if (dentry == NULL)
			goto out;
		if (IS_ERR(dentry)) {
			if (PTR_ERR(dentry) != -EINVAL)
				error = nfserrno(PTR_ERR(dentry));
			goto out;
		}

		if (S_ISDIR(dentry->d_inode->i_mode) &&
		    (dentry->d_flags & DCACHE_DISCONNECTED)) {
			printk("nfsd: find_fh_dentry returned a DISCONNECTED directory: %s/%s\n",
			       dentry->d_parent->d_name.name, dentry->d_name.name);
		}

		fhp->fh_dentry = dentry;
		fhp->fh_export = exp;
		nfsd_nr_verified++;
	} else {
		/*
		 * just rechecking permissions
		 * (e.g. nfsproc_create calls fh_verify, then nfsd_create
		 * does as well)
		 */
		dprintk("nfsd: fh_verify - just checking\n");
		dentry = fhp->fh_dentry;
		exp = fhp->fh_export;
		/*
		 * Set user creds for this exportpoint; necessary even
		 * in the "just checking" case because this may be a
		 * filehandle that was created by fh_compose, and that
		 * is about to be used in another nfsv4 compound
		 * operation.
		 */
		error = nfsd_setuser_and_check_port(rqstp, exp);
		if (error)
			goto out;
	}
	cache_get(&exp->h);


	error = nfsd_mode_check(rqstp, dentry->d_inode->i_mode, type);
	if (error)
		goto out;

	if (!(access & MAY_LOCK)) {
		/*
		 * pseudoflavor restrictions are not enforced on NLM,
		 * which clients virtually always use auth_sys for,
		 * even while using RPCSEC_GSS for NFS.
		 */
		error = check_nfsd_access(exp, rqstp);
		if (error)
			goto out;
	}

	/* Finally, check access permissions. */
	error = nfsd_permission(rqstp, exp, dentry, access);

	if (error) {
		dprintk("fh_verify: %s/%s permission failure, "
			"acc=%x, error=%d\n",
			dentry->d_parent->d_name.name,
			dentry->d_name.name,
			access, ntohl(error));
	}
out:
	if (exp && !IS_ERR(exp))
		exp_put(exp);
	if (error == nfserr_stale)
		nfsdstats.fh_stale++;
	return error;
}


/*
 * Compose a file handle for an NFS reply.
 *
 * Note that when first composed, the dentry may not yet have
 * an inode.  In this case a call to fh_update should be made
 * before the fh goes out on the wire ...
 */
static void _fh_update(struct svc_fh *fhp, struct svc_export *exp,
		struct dentry *dentry)
{
	if (dentry != exp->ex_path.dentry) {
		struct fid *fid = (struct fid *)
			(fhp->fh_handle.fh_auth + fhp->fh_handle.fh_size/4 - 1);
		int maxsize = (fhp->fh_maxsize - fhp->fh_handle.fh_size)/4;
		int subtreecheck = !(exp->ex_flags & NFSEXP_NOSUBTREECHECK);

		fhp->fh_handle.fh_fileid_type =
			exportfs_encode_fh(dentry, fid, &maxsize, subtreecheck);
		fhp->fh_handle.fh_size += maxsize * 4;
	} else {
		fhp->fh_handle.fh_fileid_type = FILEID_ROOT;
	}
}

/*
 * for composing old style file handles
 */
static inline void _fh_update_old(struct dentry *dentry,
				  struct svc_export *exp,
				  struct knfsd_fh *fh)
{
	fh->ofh_ino = ino_t_to_u32(dentry->d_inode->i_ino);
	fh->ofh_generation = dentry->d_inode->i_generation;
	if (S_ISDIR(dentry->d_inode->i_mode) ||
	    (exp->ex_flags & NFSEXP_NOSUBTREECHECK))
		fh->ofh_dirino = 0;
}

__be32
fh_compose(struct svc_fh *fhp, struct svc_export *exp, struct dentry *dentry,
	   struct svc_fh *ref_fh)
{
	/* ref_fh is a reference file handle.
	 * if it is non-null and for the same filesystem, then we should compose
	 * a filehandle which is of the same version, where possible.
	 * Currently, that means that if ref_fh->fh_handle.fh_version == 0xca
	 * Then create a 32byte filehandle using nfs_fhbase_old
	 *
	 */

	u8 version;
	u8 fsid_type = 0;
	struct inode * inode = dentry->d_inode;
	struct dentry *parent = dentry->d_parent;
	__u32 *datap;
	dev_t ex_dev = exp->ex_path.dentry->d_inode->i_sb->s_dev;
	int root_export = (exp->ex_path.dentry == exp->ex_path.dentry->d_sb->s_root);

	dprintk("nfsd: fh_compose(exp %02x:%02x/%ld %s/%s, ino=%ld)\n",
		MAJOR(ex_dev), MINOR(ex_dev),
		(long) exp->ex_path.dentry->d_inode->i_ino,
		parent->d_name.name, dentry->d_name.name,
		(inode ? inode->i_ino : 0));

	/* Choose filehandle version and fsid type based on
	 * the reference filehandle (if it is in the same export)
	 * or the export options.
	 */
 retry:
	version = 1;
	if (ref_fh && ref_fh->fh_export == exp) {
		version = ref_fh->fh_handle.fh_version;
		fsid_type = ref_fh->fh_handle.fh_fsid_type;

		if (ref_fh == fhp)
			fh_put(ref_fh);
		ref_fh = NULL;

		switch (version) {
		case 0xca:
			fsid_type = FSID_DEV;
			break;
		case 1:
			break;
		default:
			goto retry;
		}

		/* Need to check that this type works for this
		 * export point.  As the fsid -> filesystem mapping
		 * was guided by user-space, there is no guarantee
		 * that the filesystem actually supports that fsid
		 * type. If it doesn't we loop around again without
		 * ref_fh set.
		 */
		switch(fsid_type) {
		case FSID_DEV:
			if (!old_valid_dev(ex_dev))
				goto retry;
			/* FALL THROUGH */
		case FSID_MAJOR_MINOR:
		case FSID_ENCODE_DEV:
			if (!(exp->ex_path.dentry->d_inode->i_sb->s_type->fs_flags
			      & FS_REQUIRES_DEV))
				goto retry;
			break;
		case FSID_NUM:
			if (! (exp->ex_flags & NFSEXP_FSID))
				goto retry;
			break;
		case FSID_UUID8:
		case FSID_UUID16:
			if (!root_export)
				goto retry;
			/* fall through */
		case FSID_UUID4_INUM:
		case FSID_UUID16_INUM:
			if (exp->ex_uuid == NULL)
				goto retry;
			break;
		}
	} else if (exp->ex_uuid) {
		if (fhp->fh_maxsize >= 64) {
			if (root_export)
				fsid_type = FSID_UUID16;
			else
				fsid_type = FSID_UUID16_INUM;
		} else {
			if (root_export)
				fsid_type = FSID_UUID8;
			else
				fsid_type = FSID_UUID4_INUM;
		}
	} else if (exp->ex_flags & NFSEXP_FSID)
		fsid_type = FSID_NUM;
	else if (!old_valid_dev(ex_dev))
		/* for newer device numbers, we must use a newer fsid format */
		fsid_type = FSID_ENCODE_DEV;
	else
		fsid_type = FSID_DEV;

	if (ref_fh == fhp)
		fh_put(ref_fh);

	if (fhp->fh_locked || fhp->fh_dentry) {
		printk(KERN_ERR "fh_compose: fh %s/%s not initialized!\n",
		       parent->d_name.name, dentry->d_name.name);
	}
	if (fhp->fh_maxsize < NFS_FHSIZE)
		printk(KERN_ERR "fh_compose: called with maxsize %d! %s/%s\n",
		       fhp->fh_maxsize,
		       parent->d_name.name, dentry->d_name.name);

	fhp->fh_dentry = dget(dentry); /* our internal copy */
	fhp->fh_export = exp;
	cache_get(&exp->h);

	if (version == 0xca) {
		/* old style filehandle please */
		memset(&fhp->fh_handle.fh_base, 0, NFS_FHSIZE);
		fhp->fh_handle.fh_size = NFS_FHSIZE;
		fhp->fh_handle.ofh_dcookie = 0xfeebbaca;
		fhp->fh_handle.ofh_dev =  old_encode_dev(ex_dev);
		fhp->fh_handle.ofh_xdev = fhp->fh_handle.ofh_dev;
		fhp->fh_handle.ofh_xino =
			ino_t_to_u32(exp->ex_path.dentry->d_inode->i_ino);
		fhp->fh_handle.ofh_dirino = ino_t_to_u32(parent_ino(dentry));
		if (inode)
			_fh_update_old(dentry, exp, &fhp->fh_handle);
	} else {
		int len;
		fhp->fh_handle.fh_version = 1;
		fhp->fh_handle.fh_auth_type = 0;
		datap = fhp->fh_handle.fh_auth+0;
		fhp->fh_handle.fh_fsid_type = fsid_type;
		mk_fsid(fsid_type, datap, ex_dev,
			exp->ex_path.dentry->d_inode->i_ino,
			exp->ex_fsid, exp->ex_uuid);

		len = key_len(fsid_type);
		datap += len/4;
		fhp->fh_handle.fh_size = 4 + len;

		if (inode)
			_fh_update(fhp, exp, dentry);
		if (fhp->fh_handle.fh_fileid_type == 255)
			return nfserr_opnotsupp;
	}

	nfsd_nr_verified++;
	return 0;
}

/*
 * Update file handle information after changing a dentry.
 * This is only called by nfsd_create, nfsd_create_v3 and nfsd_proc_create
 */
__be32
fh_update(struct svc_fh *fhp)
{
	struct dentry *dentry;

	if (!fhp->fh_dentry)
		goto out_bad;

	dentry = fhp->fh_dentry;
	if (!dentry->d_inode)
		goto out_negative;
	if (fhp->fh_handle.fh_version != 1) {
		_fh_update_old(dentry, fhp->fh_export, &fhp->fh_handle);
	} else {
		if (fhp->fh_handle.fh_fileid_type != FILEID_ROOT)
			goto out;

		_fh_update(fhp, fhp->fh_export, dentry);
		if (fhp->fh_handle.fh_fileid_type == 255)
			return nfserr_opnotsupp;
	}
out:
	return 0;

out_bad:
	printk(KERN_ERR "fh_update: fh not verified!\n");
	goto out;
out_negative:
	printk(KERN_ERR "fh_update: %s/%s still negative!\n",
		dentry->d_parent->d_name.name, dentry->d_name.name);
	goto out;
}

/*
 * Release a file handle.
 */
void
fh_put(struct svc_fh *fhp)
{
	struct dentry * dentry = fhp->fh_dentry;
	struct svc_export * exp = fhp->fh_export;
	if (dentry) {
		fh_unlock(fhp);
		fhp->fh_dentry = NULL;
		dput(dentry);
#ifdef CONFIG_NFSD_V3
		fhp->fh_pre_saved = 0;
		fhp->fh_post_saved = 0;
#endif
		nfsd_nr_put++;
	}
	if (exp) {
		cache_put(&exp->h, &svc_export_cache);
		fhp->fh_export = NULL;
	}
	return;
}

/*
 * Shorthand for dprintk()'s
 */
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;
}

enum fsid_source fsid_source(struct svc_fh *fhp)
{
	if (fhp->fh_handle.fh_version != 1)
		return FSIDSOURCE_DEV;
	switch(fhp->fh_handle.fh_fsid_type) {
	case FSID_DEV:
	case FSID_ENCODE_DEV:
	case FSID_MAJOR_MINOR:
		if (fhp->fh_export->ex_path.dentry->d_inode->i_sb->s_type->fs_flags
		    & FS_REQUIRES_DEV)
			return FSIDSOURCE_DEV;
		break;
	case FSID_NUM:
		if (fhp->fh_export->ex_flags & NFSEXP_FSID)
			return FSIDSOURCE_FSID;
		break;
	default:
		break;
	}
	/* either a UUID type filehandle, or the filehandle doesn't
	 * match the export.
	 */
	if (fhp->fh_export->ex_flags & NFSEXP_FSID)
		return FSIDSOURCE_FSID;
	if (fhp->fh_export->ex_uuid)
		return FSIDSOURCE_UUID;
	return FSIDSOURCE_DEV;
}
Commit	Line	Data
1da177e4 LT	1	/*
	2	* linux/fs/nfsd/nfsfh.c
	3	*
	4	* NFS server file handle treatment.
	5	*
	6	* Copyright (C) 1995, 1996 Olaf Kirch <okir@monad.swb.de>
	7	* Portions Copyright (C) 1999 G. Allen Morris III <gam3@acm.org>
	8	* Extensive rewrite by Neil Brown <neilb@cse.unsw.edu.au> Southern-Spring 1999
	9	* ... and again Southern-Winter 2001 to support export_operations
	10	*/
	11
1da177e4	12	#include <linux/slab.h>
1da177e4 LT	13	#include <linux/fs.h>
	14	#include <linux/unistd.h>
	15	#include <linux/string.h>
	16	#include <linux/stat.h>
	17	#include <linux/dcache.h>
a5694255	18	#include <linux/exportfs.h>
1da177e4	19	#include <linux/mount.h>
1da177e4	20
ad06e4bd	21	#include <linux/sunrpc/clnt.h>
1da177e4	22	#include <linux/sunrpc/svc.h>
32c1eb0c	23	#include <linux/sunrpc/svcauth_gss.h>
1da177e4	24	#include <linux/nfsd/nfsd.h>
2e8138a2	25	#include "auth.h"
1da177e4 LT	26
1da177e4 LT	27	#define NFSDDBG_FACILITY NFSDDBG_FH
1da177e4 LT	28
	29
	30	static int nfsd_nr_verified;
	31	static int nfsd_nr_put;
	32
1da177e4 LT	33	/*
	34	* our acceptability function.
	35	* if NOSUBTREECHECK, accept anything
	36	* if not, require that we can walk up to exp->ex_dentry
	37	* doing some checks on the 'x' bits
	38	*/
	39	static int nfsd_acceptable(void expv, struct dentry dentry)
	40	{
	41	struct svc_export *exp = expv;
	42	int rv;
	43	struct dentry *tdentry;
	44	struct dentry *parent;
	45
	46	if (exp->ex_flags & NFSEXP_NOSUBTREECHECK)
	47	return 1;
	48
	49	tdentry = dget(dentry);
54775491	50	while (tdentry != exp->ex_path.dentry && !IS_ROOT(tdentry)) {
1da177e4 LT	51	/* make sure parents give x permission to user */
	52	int err;
	53	parent = dget_parent(tdentry);
	54	err = permission(parent->d_inode, MAY_EXEC, NULL);
	55	if (err < 0) {
	56	dput(parent);
	57	break;
	58	}
	59	dput(tdentry);
	60	tdentry = parent;
	61	}
54775491	62	if (tdentry != exp->ex_path.dentry)
1da177e4	63	dprintk("nfsd_acceptable failed at %p %s\n", tdentry, tdentry->d_name.name);
54775491	64	rv = (tdentry == exp->ex_path.dentry);
1da177e4 LT	65	dput(tdentry);
	66	return rv;
	67	}
	68
	69	/* Type check. The correct error return for type mismatches does not seem to be
	70	* generally agreed upon. SunOS seems to use EISDIR if file isn't S_IFREG; a
	71	* comment in the NFSv3 spec says this is incorrect (implementation notes for
	72	* the write call).
	73	*/
83b11340	74	static inline __be32
1da177e4 LT	75	nfsd_mode_check(struct svc_rqst *rqstp, umode_t mode, int type)
	76	{
	77	/* Type can be negative when creating hardlinks - not to a dir */
	78	if (type > 0 && (mode & S_IFMT) != type) {
	79	if (rqstp->rq_vers == 4 && (mode & S_IFMT) == S_IFLNK)
	80	return nfserr_symlink;
	81	else if (type == S_IFDIR)
	82	return nfserr_notdir;
	83	else if ((mode & S_IFMT) == S_IFDIR)
	84	return nfserr_isdir;
	85	else
	86	return nfserr_inval;
	87	}
	88	if (type < 0 && (mode & S_IFMT) == -type) {
	89	if (rqstp->rq_vers == 4 && (mode & S_IFMT) == S_IFLNK)
	90	return nfserr_symlink;
	91	else if (type == -S_IFDIR)
	92	return nfserr_isdir;
	93	else
	94	return nfserr_notdir;
	95	}
	96	return 0;
	97	}
	98
6fa02839 BF	99	static __be32 nfsd_setuser_and_check_port(struct svc_rqst *rqstp,
	100	struct svc_export *exp)
	101	{
	102	/* Check if the request originated from a secure port. */
	103	if (!rqstp->rq_secure && EX_SECURE(exp)) {
	104	char buf[RPC_MAX_ADDRBUFLEN];
	105	dprintk(KERN_WARNING
	106	"nfsd: request from insecure port %s!\n",
	107	svc_print_addr(rqstp, buf, sizeof(buf)));
	108	return nfserr_perm;
	109	}
	110
	111	/* Set user creds for this exportpoint */
	112	return nfserrno(nfsd_setuser(rqstp, exp));
	113	}
	114
1da177e4 LT	115	/*
	116	* Perform sanity checks on the dentry in a client's file handle.
	117	*
	118	* Note that the file handle dentry may need to be freed even after
	119	* an error return.
	120	*
	121	* This is only called at the start of an nfsproc call, so fhp points to
	122	* a svc_fh which is all 0 except for the over-the-wire file handle.
	123	*/
83b11340	124	__be32
1da177e4 LT	125	fh_verify(struct svc_rqst rqstp, struct svc_fh fhp, int type, int access)
	126	{
	127	struct knfsd_fh *fh = &fhp->fh_handle;
	128	struct svc_export *exp = NULL;
	129	struct dentry *dentry;
83b11340	130	__be32 error = 0;
1da177e4 LT	131
	132	dprintk("nfsd: fh_verify(%s)\n", SVCFH_fmt(fhp));
	133
1da177e4	134	if (!fhp->fh_dentry) {
6e91ea2b	135	struct fid *fid = NULL, sfid;
1da177e4 LT	136	int fileid_type;
	137	int data_left = fh->fh_size/4;
	138
	139	error = nfserr_stale;
1da177e4 LT	140	if (rqstp->rq_vers > 2)
	141	error = nfserr_badhandle;
	142	if (rqstp->rq_vers == 4 && fh->fh_size == 0)
	143	return nfserr_nofilehandle;
	144
	145	if (fh->fh_version == 1) {
	146	int len;
1da177e4 LT	147	if (--data_left<0) goto out;
	148	switch (fh->fh_auth_type) {
	149	case 0: break;
	150	default: goto out;
	151	}
	152	len = key_len(fh->fh_fsid_type) / 4;
	153	if (len == 0) goto out;
af6a4e28	154	if (fh->fh_fsid_type == FSID_MAJOR_MINOR) {
1da177e4	155	/* deprecated, convert to type 3 */
af6a4e28 N	156	len = key_len(FSID_ENCODE_DEV)/4;
af6a4e28 N	157	fh->fh_fsid_type = FSID_ENCODE_DEV;
1da177e4 LT	158	fh->fh_fsid[0] = new_encode_dev(MKDEV(ntohl(fh->fh_fsid[0]), ntohl(fh->fh_fsid[1])));
	159	fh->fh_fsid[1] = fh->fh_fsid[2];
	160	}
	161	if ((data_left -= len)<0) goto out;
6e91ea2b CH	162	exp = rqst_exp_find(rqstp, fh->fh_fsid_type,
	163	fh->fh_auth);
	164	fid = (struct fid *)(fh->fh_auth + len);
1da177e4	165	} else {
6e91ea2b	166	__u32 tfh[2];
1da177e4 LT	167	dev_t xdev;
	168	ino_t xino;
	169	if (fh->fh_size != NFS_FHSIZE)
	170	goto out;
	171	/* assume old filehandle format */
	172	xdev = old_decode_dev(fh->ofh_xdev);
	173	xino = u32_to_ino_t(fh->ofh_xino);
af6a4e28	174	mk_fsid(FSID_DEV, tfh, xdev, xino, 0, NULL);
0989a788	175	exp = rqst_exp_find(rqstp, FSID_DEV, tfh);
1da177e4 LT	176	}
1da177e4 LT	177
2d3bb252 BF	178	error = nfserr_stale;
2d3bb252 BF	179	if (PTR_ERR(exp) == -ENOENT)
1da177e4 LT	180	goto out;
1da177e4 LT	181
2d3bb252 BF	182	if (IS_ERR(exp)) {
2d3bb252 BF	183	error = nfserrno(PTR_ERR(exp));
1da177e4	184	goto out;
2d3bb252	185	}
1da177e4	186
6fa02839	187	error = nfsd_setuser_and_check_port(rqstp, exp);
d1bbf14f N	188	if (error)
	189	goto out;
	190
1da177e4 LT	191	/*
	192	* Look up the dentry using the NFS file handle.
	193	*/
	194	error = nfserr_stale;
	195	if (rqstp->rq_vers > 2)
	196	error = nfserr_badhandle;
	197
	198	if (fh->fh_version != 1) {
6e91ea2b CH	199	sfid.i32.ino = fh->ofh_ino;
	200	sfid.i32.gen = fh->ofh_generation;
	201	sfid.i32.parent_ino = fh->ofh_dirino;
	202	fid = &sfid;
1da177e4 LT	203	data_left = 3;
1da177e4 LT	204	if (fh->ofh_dirino == 0)
6e91ea2b	205	fileid_type = FILEID_INO32_GEN;
1da177e4	206	else
6e91ea2b	207	fileid_type = FILEID_INO32_GEN_PARENT;
1da177e4 LT	208	} else
1da177e4 LT	209	fileid_type = fh->fh_fileid_type;
982aedfd	210
6e91ea2b	211	if (fileid_type == FILEID_ROOT)
54775491	212	dentry = dget(exp->ex_path.dentry);
1da177e4	213	else {
54775491	214	dentry = exportfs_decode_fh(exp->ex_path.mnt, fid,
d37065cd CH	215	data_left, fileid_type,
d37065cd CH	216	nfsd_acceptable, exp);
1da177e4 LT	217	}
	218	if (dentry == NULL)
	219	goto out;
	220	if (IS_ERR(dentry)) {
	221	if (PTR_ERR(dentry) != -EINVAL)
	222	error = nfserrno(PTR_ERR(dentry));
	223	goto out;
	224	}
34e9a63b	225
1da177e4 LT	226	if (S_ISDIR(dentry->d_inode->i_mode) &&
	227	(dentry->d_flags & DCACHE_DISCONNECTED)) {
	228	printk("nfsd: find_fh_dentry returned a DISCONNECTED directory: %s/%s\n",
	229	dentry->d_parent->d_name.name, dentry->d_name.name);
	230	}
1da177e4 LT	231
	232	fhp->fh_dentry = dentry;
	233	fhp->fh_export = exp;
	234	nfsd_nr_verified++;
	235	} else {
6fa02839 BF	236	/*
	237	* just rechecking permissions
	238	* (e.g. nfsproc_create calls fh_verify, then nfsd_create
	239	* does as well)
1da177e4 LT	240	*/
	241	dprintk("nfsd: fh_verify - just checking\n");
	242	dentry = fhp->fh_dentry;
	243	exp = fhp->fh_export;
6fa02839 BF	244	/*
6fa02839 BF	245	* Set user creds for this exportpoint; necessary even
d1bbf14f N	246	* in the "just checking" case because this may be a
	247	* filehandle that was created by fh_compose, and that
	248	* is about to be used in another nfsv4 compound
6fa02839 BF	249	* operation.
	250	*/
	251	error = nfsd_setuser_and_check_port(rqstp, exp);
d1bbf14f N	252	if (error)
d1bbf14f N	253	goto out;
1da177e4 LT	254	}
	255	cache_get(&exp->h);
	256
7fc90ec9	257
1da177e4 LT	258	error = nfsd_mode_check(rqstp, dentry->d_inode->i_mode, type);
	259	if (error)
	260	goto out;
	261
9091224f BF	262	if (!(access & MAY_LOCK)) {
	263	/*
	264	* pseudoflavor restrictions are not enforced on NLM,
	265	* which clients virtually always use auth_sys for,
	266	* even while using RPCSEC_GSS for NFS.
	267	*/
	268	error = check_nfsd_access(exp, rqstp);
	269	if (error)
	270	goto out;
	271	}
32c1eb0c	272
1da177e4	273	/* Finally, check access permissions. */
0ec757df	274	error = nfsd_permission(rqstp, exp, dentry, access);
1da177e4	275
1da177e4	276	if (error) {
34e9a63b N	277	dprintk("fh_verify: %s/%s permission failure, "
	278	"acc=%x, error=%d\n",
	279	dentry->d_parent->d_name.name,
	280	dentry->d_name.name,
fc2dd2e5	281	access, ntohl(error));
1da177e4	282	}
1da177e4 LT	283	out:
	284	if (exp && !IS_ERR(exp))
	285	exp_put(exp);
	286	if (error == nfserr_stale)
	287	nfsdstats.fh_stale++;
	288	return error;
	289	}
	290
	291
	292	/*
	293	* Compose a file handle for an NFS reply.
	294	*
	295	* Note that when first composed, the dentry may not yet have
	296	* an inode. In this case a call to fh_update should be made
	297	* before the fh goes out on the wire ...
	298	*/
6e91ea2b CH	299	static void _fh_update(struct svc_fh fhp, struct svc_export exp,
6e91ea2b CH	300	struct dentry *dentry)
1da177e4	301	{
54775491	302	if (dentry != exp->ex_path.dentry) {
6e91ea2b CH	303	struct fid fid = (struct fid )
	304	(fhp->fh_handle.fh_auth + fhp->fh_handle.fh_size/4 - 1);
	305	int maxsize = (fhp->fh_maxsize - fhp->fh_handle.fh_size)/4;
	306	int subtreecheck = !(exp->ex_flags & NFSEXP_NOSUBTREECHECK);
1da177e4	307
6e91ea2b CH	308	fhp->fh_handle.fh_fileid_type =
	309	exportfs_encode_fh(dentry, fid, &maxsize, subtreecheck);
	310	fhp->fh_handle.fh_size += maxsize * 4;
	311	} else {
	312	fhp->fh_handle.fh_fileid_type = FILEID_ROOT;
	313	}
1da177e4 LT	314	}
	315
	316	/*
	317	* for composing old style file handles
	318	*/
	319	static inline void _fh_update_old(struct dentry *dentry,
	320	struct svc_export *exp,
	321	struct knfsd_fh *fh)
	322	{
	323	fh->ofh_ino = ino_t_to_u32(dentry->d_inode->i_ino);
	324	fh->ofh_generation = dentry->d_inode->i_generation;
	325	if (S_ISDIR(dentry->d_inode->i_mode) \|\|
	326	(exp->ex_flags & NFSEXP_NOSUBTREECHECK))
	327	fh->ofh_dirino = 0;
	328	}
	329
83b11340	330	__be32
982aedfd N	331	fh_compose(struct svc_fh fhp, struct svc_export exp, struct dentry *dentry,
982aedfd N	332	struct svc_fh *ref_fh)
1da177e4 LT	333	{
1da177e4 LT	334	/* ref_fh is a reference file handle.
7e405364 N	335	* if it is non-null and for the same filesystem, then we should compose
7e405364 N	336	* a filehandle which is of the same version, where possible.
1da177e4 LT	337	* Currently, that means that if ref_fh->fh_handle.fh_version == 0xca
	338	* Then create a 32byte filehandle using nfs_fhbase_old
	339	*
	340	*/
	341
b41eeef1	342	u8 version;
982aedfd	343	u8 fsid_type = 0;
1da177e4 LT	344	struct inode * inode = dentry->d_inode;
	345	struct dentry *parent = dentry->d_parent;
	346	__u32 *datap;
54775491 JB	347	dev_t ex_dev = exp->ex_path.dentry->d_inode->i_sb->s_dev;
54775491 JB	348	int root_export = (exp->ex_path.dentry == exp->ex_path.dentry->d_sb->s_root);
1da177e4 LT	349
	350	dprintk("nfsd: fh_compose(exp %02x:%02x/%ld %s/%s, ino=%ld)\n",
	351	MAJOR(ex_dev), MINOR(ex_dev),
54775491	352	(long) exp->ex_path.dentry->d_inode->i_ino,
1da177e4 LT	353	parent->d_name.name, dentry->d_name.name,
	354	(inode ? inode->i_ino : 0));
	355
982aedfd N	356	/* Choose filehandle version and fsid type based on
	357	* the reference filehandle (if it is in the same export)
	358	* or the export options.
	359	*/
b41eeef1 N	360	retry:
b41eeef1 N	361	version = 1;
7e405364	362	if (ref_fh && ref_fh->fh_export == exp) {
982aedfd	363	version = ref_fh->fh_handle.fh_version;
b41eeef1 N	364	fsid_type = ref_fh->fh_handle.fh_fsid_type;
	365
	366	if (ref_fh == fhp)
	367	fh_put(ref_fh);
	368	ref_fh = NULL;
	369
	370	switch (version) {
	371	case 0xca:
af6a4e28	372	fsid_type = FSID_DEV;
b41eeef1 N	373	break;
	374	case 1:
	375	break;
	376	default:
	377	goto retry;
	378	}
	379
	380	/* Need to check that this type works for this
	381	* export point. As the fsid -> filesystem mapping
	382	* was guided by user-space, there is no guarantee
	383	* that the filesystem actually supports that fsid
	384	* type. If it doesn't we loop around again without
	385	* ref_fh set.
982aedfd	386	*/
b41eeef1 N	387	switch(fsid_type) {
	388	case FSID_DEV:
	389	if (!old_valid_dev(ex_dev))
	390	goto retry;
	391	/* FALL THROUGH */
	392	case FSID_MAJOR_MINOR:
	393	case FSID_ENCODE_DEV:
54775491	394	if (!(exp->ex_path.dentry->d_inode->i_sb->s_type->fs_flags
b41eeef1 N	395	& FS_REQUIRES_DEV))
	396	goto retry;
	397	break;
	398	case FSID_NUM:
	399	if (! (exp->ex_flags & NFSEXP_FSID))
	400	goto retry;
	401	break;
	402	case FSID_UUID8:
	403	case FSID_UUID16:
	404	if (!root_export)
	405	goto retry;
	406	/* fall through */
	407	case FSID_UUID4_INUM:
	408	case FSID_UUID16_INUM:
	409	if (exp->ex_uuid == NULL)
	410	goto retry;
	411	break;
	412	}
af6a4e28 N	413	} else if (exp->ex_uuid) {
	414	if (fhp->fh_maxsize >= 64) {
	415	if (root_export)
	416	fsid_type = FSID_UUID16;
	417	else
	418	fsid_type = FSID_UUID16_INUM;
	419	} else {
	420	if (root_export)
	421	fsid_type = FSID_UUID8;
	422	else
	423	fsid_type = FSID_UUID4_INUM;
	424	}
1da177e4	425	} else if (exp->ex_flags & NFSEXP_FSID)
af6a4e28	426	fsid_type = FSID_NUM;
982aedfd	427	else if (!old_valid_dev(ex_dev))
1da177e4	428	/* for newer device numbers, we must use a newer fsid format */
af6a4e28	429	fsid_type = FSID_ENCODE_DEV;
982aedfd	430	else
af6a4e28	431	fsid_type = FSID_DEV;
1da177e4 LT	432
	433	if (ref_fh == fhp)
	434	fh_put(ref_fh);
	435
	436	if (fhp->fh_locked \|\| fhp->fh_dentry) {
	437	printk(KERN_ERR "fh_compose: fh %s/%s not initialized!\n",
982aedfd	438	parent->d_name.name, dentry->d_name.name);
1da177e4 LT	439	}
	440	if (fhp->fh_maxsize < NFS_FHSIZE)
	441	printk(KERN_ERR "fh_compose: called with maxsize %d! %s/%s\n",
982aedfd N	442	fhp->fh_maxsize,
982aedfd N	443	parent->d_name.name, dentry->d_name.name);
1da177e4 LT	444
	445	fhp->fh_dentry = dget(dentry); /* our internal copy */
	446	fhp->fh_export = exp;
	447	cache_get(&exp->h);
	448
982aedfd	449	if (version == 0xca) {
1da177e4 LT	450	/* old style filehandle please */
	451	memset(&fhp->fh_handle.fh_base, 0, NFS_FHSIZE);
	452	fhp->fh_handle.fh_size = NFS_FHSIZE;
	453	fhp->fh_handle.ofh_dcookie = 0xfeebbaca;
	454	fhp->fh_handle.ofh_dev = old_encode_dev(ex_dev);
	455	fhp->fh_handle.ofh_xdev = fhp->fh_handle.ofh_dev;
982aedfd	456	fhp->fh_handle.ofh_xino =
54775491	457	ino_t_to_u32(exp->ex_path.dentry->d_inode->i_ino);
1da177e4 LT	458	fhp->fh_handle.ofh_dirino = ino_t_to_u32(parent_ino(dentry));
	459	if (inode)
	460	_fh_update_old(dentry, exp, &fhp->fh_handle);
	461	} else {
	462	int len;
	463	fhp->fh_handle.fh_version = 1;
	464	fhp->fh_handle.fh_auth_type = 0;
	465	datap = fhp->fh_handle.fh_auth+0;
982aedfd	466	fhp->fh_handle.fh_fsid_type = fsid_type;
af6a4e28	467	mk_fsid(fsid_type, datap, ex_dev,
54775491	468	exp->ex_path.dentry->d_inode->i_ino,
af6a4e28 N	469	exp->ex_fsid, exp->ex_uuid);
af6a4e28 N	470
982aedfd	471	len = key_len(fsid_type);
1da177e4 LT	472	datap += len/4;
	473	fhp->fh_handle.fh_size = 4 + len;
	474
6e91ea2b CH	475	if (inode)
6e91ea2b CH	476	_fh_update(fhp, exp, dentry);
1da177e4 LT	477	if (fhp->fh_handle.fh_fileid_type == 255)
	478	return nfserr_opnotsupp;
	479	}
	480
	481	nfsd_nr_verified++;
	482	return 0;
	483	}
	484
	485	/*
	486	* Update file handle information after changing a dentry.
	487	* This is only called by nfsd_create, nfsd_create_v3 and nfsd_proc_create
	488	*/
83b11340	489	__be32
1da177e4 LT	490	fh_update(struct svc_fh *fhp)
	491	{
	492	struct dentry *dentry;
982aedfd	493
1da177e4 LT	494	if (!fhp->fh_dentry)
	495	goto out_bad;
	496
	497	dentry = fhp->fh_dentry;
	498	if (!dentry->d_inode)
	499	goto out_negative;
	500	if (fhp->fh_handle.fh_version != 1) {
	501	_fh_update_old(dentry, fhp->fh_export, &fhp->fh_handle);
	502	} else {
6e91ea2b	503	if (fhp->fh_handle.fh_fileid_type != FILEID_ROOT)
4c9608b2	504	goto out;
6e91ea2b CH	505
6e91ea2b CH	506	_fh_update(fhp, fhp->fh_export, dentry);
1da177e4 LT	507	if (fhp->fh_handle.fh_fileid_type == 255)
	508	return nfserr_opnotsupp;
	509	}
	510	out:
	511	return 0;
	512
	513	out_bad:
	514	printk(KERN_ERR "fh_update: fh not verified!\n");
	515	goto out;
	516	out_negative:
	517	printk(KERN_ERR "fh_update: %s/%s still negative!\n",
	518	dentry->d_parent->d_name.name, dentry->d_name.name);
	519	goto out;
1da177e4 LT	520	}
	521
	522	/*
	523	* Release a file handle.
	524	*/
	525	void
	526	fh_put(struct svc_fh *fhp)
	527	{
	528	struct dentry * dentry = fhp->fh_dentry;
	529	struct svc_export * exp = fhp->fh_export;
	530	if (dentry) {
	531	fh_unlock(fhp);
	532	fhp->fh_dentry = NULL;
	533	dput(dentry);
	534	#ifdef CONFIG_NFSD_V3
	535	fhp->fh_pre_saved = 0;
	536	fhp->fh_post_saved = 0;
	537	#endif
	538	nfsd_nr_put++;
	539	}
	540	if (exp) {
baab935f	541	cache_put(&exp->h, &svc_export_cache);
1da177e4 LT	542	fhp->fh_export = NULL;
	543	}
	544	return;
	545	}
	546
	547	/*
	548	* Shorthand for dprintk()'s
	549	*/
	550	char * SVCFH_fmt(struct svc_fh *fhp)
	551	{
	552	struct knfsd_fh *fh = &fhp->fh_handle;
	553
	554	static char buf[80];
	555	sprintf(buf, "%d: %08x %08x %08x %08x %08x %08x",
	556	fh->fh_size,
	557	fh->fh_base.fh_pad[0],
	558	fh->fh_base.fh_pad[1],
	559	fh->fh_base.fh_pad[2],
	560	fh->fh_base.fh_pad[3],
	561	fh->fh_base.fh_pad[4],
	562	fh->fh_base.fh_pad[5]);
	563	return buf;
	564	}
af6a4e28 N	565
	566	enum fsid_source fsid_source(struct svc_fh *fhp)
	567	{
	568	if (fhp->fh_handle.fh_version != 1)
	569	return FSIDSOURCE_DEV;
	570	switch(fhp->fh_handle.fh_fsid_type) {
	571	case FSID_DEV:
	572	case FSID_ENCODE_DEV:
	573	case FSID_MAJOR_MINOR:
54775491	574	if (fhp->fh_export->ex_path.dentry->d_inode->i_sb->s_type->fs_flags
b8da0d1c NB	575	& FS_REQUIRES_DEV)
	576	return FSIDSOURCE_DEV;
	577	break;
af6a4e28	578	case FSID_NUM:
af6a4e28 N	579	if (fhp->fh_export->ex_flags & NFSEXP_FSID)
af6a4e28 N	580	return FSIDSOURCE_FSID;
b8da0d1c NB	581	break;
	582	default:
	583	break;
af6a4e28	584	}
b8da0d1c NB	585	/* either a UUID type filehandle, or the filehandle doesn't
	586	* match the export.
	587	*/
	588	if (fhp->fh_export->ex_flags & NFSEXP_FSID)
	589	return FSIDSOURCE_FSID;
	590	if (fhp->fh_export->ex_uuid)
	591	return FSIDSOURCE_UUID;
	592	return FSIDSOURCE_DEV;
af6a4e28	593	}