[net-next-2.6.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>

#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_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_dentry)
		dprintk("nfsd_acceptable failed at %p %s\n", tdentry, tdentry->d_name.name);
	rv = (tdentry == exp->ex_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;
}

/*
 * 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) {
		__u32 *datap=NULL;
		__u32 tfh[3];		/* filehandle fragment for oldstyle filehandles */
		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;
			datap = fh->fh_auth;
			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, datap);
			datap += len;
		} else {
			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;
		}

		/* Check if the request originated from a secure port. */
		error = nfserr_perm;
		if (!rqstp->rq_secure && EX_SECURE(exp)) {
			char buf[RPC_MAX_ADDRBUFLEN];
			printk(KERN_WARNING
			       "nfsd: request from insecure port %s!\n",
			       svc_print_addr(rqstp, buf, sizeof(buf)));
			goto out;
		}

		/* Set user creds for this exportpoint */
		error = nfserrno(nfsd_setuser(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) {
			tfh[0] = fh->ofh_ino;
			tfh[1] = fh->ofh_generation;
			tfh[2] = fh->ofh_dirino;
			datap = tfh;
			data_left = 3;
			if (fh->ofh_dirino == 0)
				fileid_type = 1;
			else
				fileid_type = 2;
		} else
			fileid_type = fh->fh_fileid_type;

		if (fileid_type == 0)
			dentry = dget(exp->ex_dentry);
		else {
			dentry = exportfs_decode_fh(exp->ex_mnt, datap,
					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 = nfserrno(nfsd_setuser(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 inline int _fh_update(struct dentry *dentry, struct svc_export *exp,
			     __u32 *datap, int *maxsize)
{
	if (dentry == exp->ex_dentry) {
		*maxsize = 0;
		return 0;
	}

	return exportfs_encode_fh(dentry, datap, maxsize,
			  !(exp->ex_flags & NFSEXP_NOSUBTREECHECK));
}

/*
 * 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_dentry->d_inode->i_sb->s_dev;
	int root_export = (exp->ex_dentry == exp->ex_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_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_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_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_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) {
			int size = (fhp->fh_maxsize-len-4)/4;
			fhp->fh_handle.fh_fileid_type =
				_fh_update(dentry, exp, datap, &size);
			fhp->fh_handle.fh_size += size*4;
		}
		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;
	__u32 *datap;

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