[mirror_ubuntu-artful-kernel.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 = inode_permission(parent->d_inode, MAY_EXEC);
		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)) {
		RPC_IFDEBUG(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));
}

/*
 * Use the given filehandle to look up the corresponding export and
 * dentry.  On success, the results are used to set fh_export and
 * fh_dentry.
 */
static __be32 nfsd_set_fh_dentry(struct svc_rqst *rqstp, struct svc_fh *fhp)
{
	struct knfsd_fh	*fh = &fhp->fh_handle;
	struct fid *fid = NULL, sfid;
	struct svc_export *exp;
	struct dentry *dentry;
	int fileid_type;
	int data_left = fh->fh_size/4;
	__be32 error;

	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)
			return error;
		if (fh->fh_auth_type != 0)
			return error;
		len = key_len(fh->fh_fsid_type) / 4;
		if (len == 0)
			return error;
		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];
		}
		data_left -= len;
		if (data_left < 0)
			return error;
		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)
			return error;
		/* 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)
		return error;

	if (IS_ERR(exp))
		return nfserrno(PTR_ERR(exp));

	if (exp->ex_flags & NFSEXP_NOSUBTREECHECK) {
		/* Elevate privileges so that the lack of 'r' or 'x'
		 * permission on some parent directory will
		 * not stop exportfs_decode_fh from being able
		 * to reconnect a directory into the dentry cache.
		 * The same problem can affect "SUBTREECHECK" exports,
		 * but as nfsd_acceptable depends on correct
		 * access control settings being in effect, we cannot
		 * fix that case easily.
		 */
		current->cred->cap_effective =
			cap_raise_nfsd_set(current->cred->cap_effective,
					   current->cred->cap_permitted);
	} else {
		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 (exp->ex_flags & NFSEXP_NOSUBTREECHECK) {
		error = nfsd_setuser_and_check_port(rqstp, exp);
		if (error) {
			dput(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++;
	return 0;
out:
	exp_put(exp);
	return error;
}

/*
 * 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 svc_export *exp;
	struct dentry	*dentry;
	__be32		error;

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

	if (!fhp->fh_dentry) {
		error = nfsd_set_fh_dentry(rqstp, fhp);
		if (error)
			goto out;
		dentry = fhp->fh_dentry;
		exp = fhp->fh_export;
	} 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;
	}

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

	/*
	 * pseudoflavor restrictions are not enforced on NLM,
	 * which clients virtually always use auth_sys for,
	 * even while using RPCSEC_GSS for NFS.
	 */
	if (access & NFSD_MAY_LOCK)
		goto skip_pseudoflavor_check;
	/*
	 * Clients may expect to be able to use auth_sys during mount,
	 * even if they use gss for everything else; see section 2.3.2
	 * of rfc 2623.
	 */
	if (access & NFSD_MAY_BYPASS_GSS_ON_ROOT
			&& exp->ex_path.dentry == dentry)
		goto skip_pseudoflavor_check;

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

skip_pseudoflavor_check:
	/* 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 (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);
f419a2e3	54	err = inode_permission(parent->d_inode, MAY_EXEC);
1da177e4 LT	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)) {
5216a8e7	104	RPC_IFDEBUG(char buf[RPC_MAX_ADDRBUFLEN]);
6fa02839 BF	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
03550fac BF	115	/*
	116	* Use the given filehandle to look up the corresponding export and
	117	* dentry. On success, the results are used to set fh_export and
	118	* fh_dentry.
	119	*/
	120	static __be32 nfsd_set_fh_dentry(struct svc_rqst rqstp, struct svc_fh fhp)
	121	{
	122	struct knfsd_fh *fh = &fhp->fh_handle;
	123	struct fid *fid = NULL, sfid;
	124	struct svc_export *exp;
	125	struct dentry *dentry;
	126	int fileid_type;
	127	int data_left = fh->fh_size/4;
	128	__be32 error;
	129
	130	error = nfserr_stale;
	131	if (rqstp->rq_vers > 2)
	132	error = nfserr_badhandle;
	133	if (rqstp->rq_vers == 4 && fh->fh_size == 0)
	134	return nfserr_nofilehandle;
	135
	136	if (fh->fh_version == 1) {
	137	int len;
	138
	139	if (--data_left < 0)
	140	return error;
	141	if (fh->fh_auth_type != 0)
	142	return error;
	143	len = key_len(fh->fh_fsid_type) / 4;
	144	if (len == 0)
	145	return error;
	146	if (fh->fh_fsid_type == FSID_MAJOR_MINOR) {
	147	/* deprecated, convert to type 3 */
	148	len = key_len(FSID_ENCODE_DEV)/4;
	149	fh->fh_fsid_type = FSID_ENCODE_DEV;
	150	fh->fh_fsid[0] = new_encode_dev(MKDEV(ntohl(fh->fh_fsid[0]), ntohl(fh->fh_fsid[1])));
	151	fh->fh_fsid[1] = fh->fh_fsid[2];
	152	}
	153	data_left -= len;
	154	if (data_left < 0)
	155	return error;
	156	exp = rqst_exp_find(rqstp, fh->fh_fsid_type, fh->fh_auth);
	157	fid = (struct fid *)(fh->fh_auth + len);
	158	} else {
	159	__u32 tfh[2];
	160	dev_t xdev;
	161	ino_t xino;
	162
	163	if (fh->fh_size != NFS_FHSIZE)
	164	return error;
	165	/* assume old filehandle format */
	166	xdev = old_decode_dev(fh->ofh_xdev);
	167	xino = u32_to_ino_t(fh->ofh_xino);
	168	mk_fsid(FSID_DEV, tfh, xdev, xino, 0, NULL);
	169	exp = rqst_exp_find(rqstp, FSID_DEV, tfh);
	170	}
	171
	172	error = nfserr_stale;
	173	if (PTR_ERR(exp) == -ENOENT)
	174	return error;
	175
	176	if (IS_ERR(exp))
	177	return nfserrno(PTR_ERR(exp));
	178
496d6c32 NB	179	if (exp->ex_flags & NFSEXP_NOSUBTREECHECK) {
	180	/* Elevate privileges so that the lack of 'r' or 'x'
	181	* permission on some parent directory will
	182	* not stop exportfs_decode_fh from being able
	183	* to reconnect a directory into the dentry cache.
	184	* The same problem can affect "SUBTREECHECK" exports,
	185	* but as nfsd_acceptable depends on correct
	186	* access control settings being in effect, we cannot
	187	* fix that case easily.
	188	*/
b6dff3ec DH	189	current->cred->cap_effective =
	190	cap_raise_nfsd_set(current->cred->cap_effective,
	191	current->cred->cap_permitted);
496d6c32 NB	192	} else {
	193	error = nfsd_setuser_and_check_port(rqstp, exp);
	194	if (error)
	195	goto out;
	196	}
03550fac BF	197
	198	/*
	199	* Look up the dentry using the NFS file handle.
	200	*/
	201	error = nfserr_stale;
	202	if (rqstp->rq_vers > 2)
	203	error = nfserr_badhandle;
	204
	205	if (fh->fh_version != 1) {
	206	sfid.i32.ino = fh->ofh_ino;
	207	sfid.i32.gen = fh->ofh_generation;
	208	sfid.i32.parent_ino = fh->ofh_dirino;
	209	fid = &sfid;
	210	data_left = 3;
	211	if (fh->ofh_dirino == 0)
	212	fileid_type = FILEID_INO32_GEN;
	213	else
	214	fileid_type = FILEID_INO32_GEN_PARENT;
	215	} else
	216	fileid_type = fh->fh_fileid_type;
	217
	218	if (fileid_type == FILEID_ROOT)
	219	dentry = dget(exp->ex_path.dentry);
	220	else {
	221	dentry = exportfs_decode_fh(exp->ex_path.mnt, fid,
	222	data_left, fileid_type,
	223	nfsd_acceptable, exp);
	224	}
	225	if (dentry == NULL)
	226	goto out;
	227	if (IS_ERR(dentry)) {
	228	if (PTR_ERR(dentry) != -EINVAL)
	229	error = nfserrno(PTR_ERR(dentry));
	230	goto out;
	231	}
	232
496d6c32 NB	233	if (exp->ex_flags & NFSEXP_NOSUBTREECHECK) {
	234	error = nfsd_setuser_and_check_port(rqstp, exp);
	235	if (error) {
	236	dput(dentry);
	237	goto out;
	238	}
	239	}
	240
03550fac BF	241	if (S_ISDIR(dentry->d_inode->i_mode) &&
	242	(dentry->d_flags & DCACHE_DISCONNECTED)) {
	243	printk("nfsd: find_fh_dentry returned a DISCONNECTED directory: %s/%s\n",
	244	dentry->d_parent->d_name.name, dentry->d_name.name);
	245	}
	246
	247	fhp->fh_dentry = dentry;
	248	fhp->fh_export = exp;
	249	nfsd_nr_verified++;
	250	return 0;
	251	out:
	252	exp_put(exp);
	253	return error;
	254	}
	255
1da177e4 LT	256	/*
	257	* Perform sanity checks on the dentry in a client's file handle.
	258	*
	259	* Note that the file handle dentry may need to be freed even after
	260	* an error return.
	261	*
	262	* This is only called at the start of an nfsproc call, so fhp points to
	263	* a svc_fh which is all 0 except for the over-the-wire file handle.
	264	*/
83b11340	265	__be32
1da177e4 LT	266	fh_verify(struct svc_rqst rqstp, struct svc_fh fhp, int type, int access)
1da177e4 LT	267	{
03550fac	268	struct svc_export *exp;
1da177e4	269	struct dentry *dentry;
03550fac	270	__be32 error;
1da177e4 LT	271
	272	dprintk("nfsd: fh_verify(%s)\n", SVCFH_fmt(fhp));
	273
1da177e4	274	if (!fhp->fh_dentry) {
03550fac	275	error = nfsd_set_fh_dentry(rqstp, fhp);
d1bbf14f N	276	if (error)
d1bbf14f N	277	goto out;
03550fac BF	278	dentry = fhp->fh_dentry;
03550fac BF	279	exp = fhp->fh_export;
1da177e4	280	} else {
6fa02839 BF	281	/*
	282	* just rechecking permissions
	283	* (e.g. nfsproc_create calls fh_verify, then nfsd_create
	284	* does as well)
1da177e4 LT	285	*/
	286	dprintk("nfsd: fh_verify - just checking\n");
	287	dentry = fhp->fh_dentry;
	288	exp = fhp->fh_export;
6fa02839 BF	289	/*
6fa02839 BF	290	* Set user creds for this exportpoint; necessary even
d1bbf14f N	291	* in the "just checking" case because this may be a
	292	* filehandle that was created by fh_compose, and that
	293	* is about to be used in another nfsv4 compound
6fa02839 BF	294	* operation.
	295	*/
	296	error = nfsd_setuser_and_check_port(rqstp, exp);
d1bbf14f N	297	if (error)
d1bbf14f N	298	goto out;
1da177e4	299	}
7fc90ec9	300
1da177e4 LT	301	error = nfsd_mode_check(rqstp, dentry->d_inode->i_mode, type);
	302	if (error)
	303	goto out;
	304
04716e66 BF	305	/*
	306	* pseudoflavor restrictions are not enforced on NLM,
	307	* which clients virtually always use auth_sys for,
	308	* even while using RPCSEC_GSS for NFS.
	309	*/
	310	if (access & NFSD_MAY_LOCK)
	311	goto skip_pseudoflavor_check;
	312	/*
	313	* Clients may expect to be able to use auth_sys during mount,
	314	* even if they use gss for everything else; see section 2.3.2
	315	* of rfc 2623.
	316	*/
	317	if (access & NFSD_MAY_BYPASS_GSS_ON_ROOT
	318	&& exp->ex_path.dentry == dentry)
	319	goto skip_pseudoflavor_check;
	320
	321	error = check_nfsd_access(exp, rqstp);
	322	if (error)
	323	goto out;
32c1eb0c	324
04716e66	325	skip_pseudoflavor_check:
1da177e4	326	/* Finally, check access permissions. */
0ec757df	327	error = nfsd_permission(rqstp, exp, dentry, access);
1da177e4	328
1da177e4	329	if (error) {
34e9a63b N	330	dprintk("fh_verify: %s/%s permission failure, "
	331	"acc=%x, error=%d\n",
	332	dentry->d_parent->d_name.name,
	333	dentry->d_name.name,
fc2dd2e5	334	access, ntohl(error));
1da177e4	335	}
1da177e4	336	out:
1da177e4 LT	337	if (error == nfserr_stale)
	338	nfsdstats.fh_stale++;
	339	return error;
	340	}
	341
	342
	343	/*
	344	* Compose a file handle for an NFS reply.
	345	*
	346	* Note that when first composed, the dentry may not yet have
	347	* an inode. In this case a call to fh_update should be made
	348	* before the fh goes out on the wire ...
	349	*/
6e91ea2b CH	350	static void _fh_update(struct svc_fh fhp, struct svc_export exp,
6e91ea2b CH	351	struct dentry *dentry)
1da177e4	352	{
54775491	353	if (dentry != exp->ex_path.dentry) {
6e91ea2b CH	354	struct fid fid = (struct fid )
	355	(fhp->fh_handle.fh_auth + fhp->fh_handle.fh_size/4 - 1);
	356	int maxsize = (fhp->fh_maxsize - fhp->fh_handle.fh_size)/4;
	357	int subtreecheck = !(exp->ex_flags & NFSEXP_NOSUBTREECHECK);
1da177e4	358
6e91ea2b CH	359	fhp->fh_handle.fh_fileid_type =
	360	exportfs_encode_fh(dentry, fid, &maxsize, subtreecheck);
	361	fhp->fh_handle.fh_size += maxsize * 4;
	362	} else {
	363	fhp->fh_handle.fh_fileid_type = FILEID_ROOT;
	364	}
1da177e4 LT	365	}
	366
	367	/*
	368	* for composing old style file handles
	369	*/
	370	static inline void _fh_update_old(struct dentry *dentry,
	371	struct svc_export *exp,
	372	struct knfsd_fh *fh)
	373	{
	374	fh->ofh_ino = ino_t_to_u32(dentry->d_inode->i_ino);
	375	fh->ofh_generation = dentry->d_inode->i_generation;
	376	if (S_ISDIR(dentry->d_inode->i_mode) \|\|
	377	(exp->ex_flags & NFSEXP_NOSUBTREECHECK))
	378	fh->ofh_dirino = 0;
	379	}
	380
83b11340	381	__be32
982aedfd N	382	fh_compose(struct svc_fh fhp, struct svc_export exp, struct dentry *dentry,
982aedfd N	383	struct svc_fh *ref_fh)
1da177e4 LT	384	{
1da177e4 LT	385	/* ref_fh is a reference file handle.
7e405364 N	386	* if it is non-null and for the same filesystem, then we should compose
7e405364 N	387	* a filehandle which is of the same version, where possible.
1da177e4 LT	388	* Currently, that means that if ref_fh->fh_handle.fh_version == 0xca
	389	* Then create a 32byte filehandle using nfs_fhbase_old
	390	*
	391	*/
	392
b41eeef1	393	u8 version;
982aedfd	394	u8 fsid_type = 0;
1da177e4 LT	395	struct inode * inode = dentry->d_inode;
	396	struct dentry *parent = dentry->d_parent;
	397	__u32 *datap;
54775491 JB	398	dev_t ex_dev = exp->ex_path.dentry->d_inode->i_sb->s_dev;
54775491 JB	399	int root_export = (exp->ex_path.dentry == exp->ex_path.dentry->d_sb->s_root);
1da177e4 LT	400
	401	dprintk("nfsd: fh_compose(exp %02x:%02x/%ld %s/%s, ino=%ld)\n",
	402	MAJOR(ex_dev), MINOR(ex_dev),
54775491	403	(long) exp->ex_path.dentry->d_inode->i_ino,
1da177e4 LT	404	parent->d_name.name, dentry->d_name.name,
	405	(inode ? inode->i_ino : 0));
	406
982aedfd N	407	/* Choose filehandle version and fsid type based on
	408	* the reference filehandle (if it is in the same export)
	409	* or the export options.
	410	*/
b41eeef1 N	411	retry:
b41eeef1 N	412	version = 1;
7e405364	413	if (ref_fh && ref_fh->fh_export == exp) {
982aedfd	414	version = ref_fh->fh_handle.fh_version;
b41eeef1 N	415	fsid_type = ref_fh->fh_handle.fh_fsid_type;
	416
	417	if (ref_fh == fhp)
	418	fh_put(ref_fh);
	419	ref_fh = NULL;
	420
	421	switch (version) {
	422	case 0xca:
af6a4e28	423	fsid_type = FSID_DEV;
b41eeef1 N	424	break;
	425	case 1:
	426	break;
	427	default:
	428	goto retry;
	429	}
	430
	431	/* Need to check that this type works for this
	432	* export point. As the fsid -> filesystem mapping
	433	* was guided by user-space, there is no guarantee
	434	* that the filesystem actually supports that fsid
	435	* type. If it doesn't we loop around again without
	436	* ref_fh set.
982aedfd	437	*/
b41eeef1 N	438	switch(fsid_type) {
	439	case FSID_DEV:
	440	if (!old_valid_dev(ex_dev))
	441	goto retry;
	442	/* FALL THROUGH */
	443	case FSID_MAJOR_MINOR:
	444	case FSID_ENCODE_DEV:
54775491	445	if (!(exp->ex_path.dentry->d_inode->i_sb->s_type->fs_flags
b41eeef1 N	446	& FS_REQUIRES_DEV))
	447	goto retry;
	448	break;
	449	case FSID_NUM:
	450	if (! (exp->ex_flags & NFSEXP_FSID))
	451	goto retry;
	452	break;
	453	case FSID_UUID8:
	454	case FSID_UUID16:
	455	if (!root_export)
	456	goto retry;
	457	/* fall through */
	458	case FSID_UUID4_INUM:
	459	case FSID_UUID16_INUM:
	460	if (exp->ex_uuid == NULL)
	461	goto retry;
	462	break;
	463	}
af6a4e28 N	464	} else if (exp->ex_uuid) {
	465	if (fhp->fh_maxsize >= 64) {
	466	if (root_export)
	467	fsid_type = FSID_UUID16;
	468	else
	469	fsid_type = FSID_UUID16_INUM;
	470	} else {
	471	if (root_export)
	472	fsid_type = FSID_UUID8;
	473	else
	474	fsid_type = FSID_UUID4_INUM;
	475	}
1da177e4	476	} else if (exp->ex_flags & NFSEXP_FSID)
af6a4e28	477	fsid_type = FSID_NUM;
982aedfd	478	else if (!old_valid_dev(ex_dev))
1da177e4	479	/* for newer device numbers, we must use a newer fsid format */
af6a4e28	480	fsid_type = FSID_ENCODE_DEV;
982aedfd	481	else
af6a4e28	482	fsid_type = FSID_DEV;
1da177e4 LT	483
	484	if (ref_fh == fhp)
	485	fh_put(ref_fh);
	486
	487	if (fhp->fh_locked \|\| fhp->fh_dentry) {
	488	printk(KERN_ERR "fh_compose: fh %s/%s not initialized!\n",
982aedfd	489	parent->d_name.name, dentry->d_name.name);
1da177e4 LT	490	}
	491	if (fhp->fh_maxsize < NFS_FHSIZE)
	492	printk(KERN_ERR "fh_compose: called with maxsize %d! %s/%s\n",
982aedfd N	493	fhp->fh_maxsize,
982aedfd N	494	parent->d_name.name, dentry->d_name.name);
1da177e4 LT	495
	496	fhp->fh_dentry = dget(dentry); /* our internal copy */
	497	fhp->fh_export = exp;
	498	cache_get(&exp->h);
	499
982aedfd	500	if (version == 0xca) {
1da177e4 LT	501	/* old style filehandle please */
	502	memset(&fhp->fh_handle.fh_base, 0, NFS_FHSIZE);
	503	fhp->fh_handle.fh_size = NFS_FHSIZE;
	504	fhp->fh_handle.ofh_dcookie = 0xfeebbaca;
	505	fhp->fh_handle.ofh_dev = old_encode_dev(ex_dev);
	506	fhp->fh_handle.ofh_xdev = fhp->fh_handle.ofh_dev;
982aedfd	507	fhp->fh_handle.ofh_xino =
54775491	508	ino_t_to_u32(exp->ex_path.dentry->d_inode->i_ino);
1da177e4 LT	509	fhp->fh_handle.ofh_dirino = ino_t_to_u32(parent_ino(dentry));
	510	if (inode)
	511	_fh_update_old(dentry, exp, &fhp->fh_handle);
	512	} else {
	513	int len;
	514	fhp->fh_handle.fh_version = 1;
	515	fhp->fh_handle.fh_auth_type = 0;
	516	datap = fhp->fh_handle.fh_auth+0;
982aedfd	517	fhp->fh_handle.fh_fsid_type = fsid_type;
af6a4e28	518	mk_fsid(fsid_type, datap, ex_dev,
54775491	519	exp->ex_path.dentry->d_inode->i_ino,
af6a4e28 N	520	exp->ex_fsid, exp->ex_uuid);
af6a4e28 N	521
982aedfd	522	len = key_len(fsid_type);
1da177e4 LT	523	datap += len/4;
	524	fhp->fh_handle.fh_size = 4 + len;
	525
6e91ea2b CH	526	if (inode)
6e91ea2b CH	527	_fh_update(fhp, exp, dentry);
1da177e4 LT	528	if (fhp->fh_handle.fh_fileid_type == 255)
	529	return nfserr_opnotsupp;
	530	}
	531
	532	nfsd_nr_verified++;
	533	return 0;
	534	}
	535
	536	/*
	537	* Update file handle information after changing a dentry.
	538	* This is only called by nfsd_create, nfsd_create_v3 and nfsd_proc_create
	539	*/
83b11340	540	__be32
1da177e4 LT	541	fh_update(struct svc_fh *fhp)
	542	{
	543	struct dentry *dentry;
982aedfd	544
1da177e4 LT	545	if (!fhp->fh_dentry)
	546	goto out_bad;
	547
	548	dentry = fhp->fh_dentry;
	549	if (!dentry->d_inode)
	550	goto out_negative;
	551	if (fhp->fh_handle.fh_version != 1) {
	552	_fh_update_old(dentry, fhp->fh_export, &fhp->fh_handle);
	553	} else {
6e91ea2b	554	if (fhp->fh_handle.fh_fileid_type != FILEID_ROOT)
4c9608b2	555	goto out;
6e91ea2b CH	556
6e91ea2b CH	557	_fh_update(fhp, fhp->fh_export, dentry);
1da177e4 LT	558	if (fhp->fh_handle.fh_fileid_type == 255)
	559	return nfserr_opnotsupp;
	560	}
	561	out:
	562	return 0;
	563
	564	out_bad:
	565	printk(KERN_ERR "fh_update: fh not verified!\n");
	566	goto out;
	567	out_negative:
	568	printk(KERN_ERR "fh_update: %s/%s still negative!\n",
	569	dentry->d_parent->d_name.name, dentry->d_name.name);
	570	goto out;
1da177e4 LT	571	}
	572
	573	/*
	574	* Release a file handle.
	575	*/
	576	void
	577	fh_put(struct svc_fh *fhp)
	578	{
	579	struct dentry * dentry = fhp->fh_dentry;
	580	struct svc_export * exp = fhp->fh_export;
	581	if (dentry) {
	582	fh_unlock(fhp);
	583	fhp->fh_dentry = NULL;
	584	dput(dentry);
	585	#ifdef CONFIG_NFSD_V3
	586	fhp->fh_pre_saved = 0;
	587	fhp->fh_post_saved = 0;
	588	#endif
	589	nfsd_nr_put++;
	590	}
	591	if (exp) {
baab935f	592	cache_put(&exp->h, &svc_export_cache);
1da177e4 LT	593	fhp->fh_export = NULL;
	594	}
	595	return;
	596	}
	597
	598	/*
	599	* Shorthand for dprintk()'s
	600	*/
	601	char * SVCFH_fmt(struct svc_fh *fhp)
	602	{
	603	struct knfsd_fh *fh = &fhp->fh_handle;
	604
	605	static char buf[80];
	606	sprintf(buf, "%d: %08x %08x %08x %08x %08x %08x",
	607	fh->fh_size,
	608	fh->fh_base.fh_pad[0],
	609	fh->fh_base.fh_pad[1],
	610	fh->fh_base.fh_pad[2],
	611	fh->fh_base.fh_pad[3],
	612	fh->fh_base.fh_pad[4],
	613	fh->fh_base.fh_pad[5]);
	614	return buf;
	615	}
af6a4e28 N	616
	617	enum fsid_source fsid_source(struct svc_fh *fhp)
	618	{
	619	if (fhp->fh_handle.fh_version != 1)
	620	return FSIDSOURCE_DEV;
	621	switch(fhp->fh_handle.fh_fsid_type) {
	622	case FSID_DEV:
	623	case FSID_ENCODE_DEV:
	624	case FSID_MAJOR_MINOR:
54775491	625	if (fhp->fh_export->ex_path.dentry->d_inode->i_sb->s_type->fs_flags
b8da0d1c NB	626	& FS_REQUIRES_DEV)
	627	return FSIDSOURCE_DEV;
	628	break;
af6a4e28	629	case FSID_NUM:
af6a4e28 N	630	if (fhp->fh_export->ex_flags & NFSEXP_FSID)
af6a4e28 N	631	return FSIDSOURCE_FSID;
b8da0d1c NB	632	break;
	633	default:
	634	break;
af6a4e28	635	}
b8da0d1c NB	636	/* either a UUID type filehandle, or the filehandle doesn't
	637	* match the export.
	638	*/
	639	if (fhp->fh_export->ex_flags & NFSEXP_FSID)
	640	return FSIDSOURCE_FSID;
	641	if (fhp->fh_export->ex_uuid)
	642	return FSIDSOURCE_UUID;
	643	return FSIDSOURCE_DEV;
af6a4e28	644	}