nfs2xdr.c 26 KB
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// SPDX-License-Identifier: GPL-2.0
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/*
 * linux/fs/nfs/nfs2xdr.c
 *
 * XDR functions to encode/decode NFS RPC arguments and results.
 *
 * Copyright (C) 1992, 1993, 1994  Rick Sladkey
 * Copyright (C) 1996 Olaf Kirch
 * 04 Aug 1998  Ion Badulescu <ionut@cs.columbia.edu>
 * 		FIFO's need special handling in NFSv2
 */

#include <linux/param.h>
#include <linux/time.h>
#include <linux/mm.h>
#include <linux/errno.h>
#include <linux/string.h>
#include <linux/in.h>
#include <linux/pagemap.h>
#include <linux/proc_fs.h>
#include <linux/sunrpc/clnt.h>
#include <linux/nfs.h>
#include <linux/nfs2.h>
#include <linux/nfs_fs.h>
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#include "nfstrace.h"
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#include "internal.h"

#define NFSDBG_FACILITY		NFSDBG_XDR

/* Mapping from NFS error code to "errno" error code. */
#define errno_NFSERR_IO		EIO

/*
 * Declare the space requirements for NFS arguments and replies as
 * number of 32bit-words
 */
#define NFS_fhandle_sz		(8)
#define NFS_sattr_sz		(8)
#define NFS_filename_sz		(1+(NFS2_MAXNAMLEN>>2))
#define NFS_path_sz		(1+(NFS2_MAXPATHLEN>>2))
#define NFS_fattr_sz		(17)
#define NFS_info_sz		(5)
#define NFS_entry_sz		(NFS_filename_sz+3)

#define NFS_diropargs_sz	(NFS_fhandle_sz+NFS_filename_sz)
#define NFS_removeargs_sz	(NFS_fhandle_sz+NFS_filename_sz)
#define NFS_sattrargs_sz	(NFS_fhandle_sz+NFS_sattr_sz)
#define NFS_readlinkargs_sz	(NFS_fhandle_sz)
#define NFS_readargs_sz		(NFS_fhandle_sz+3)
#define NFS_writeargs_sz	(NFS_fhandle_sz+4)
#define NFS_createargs_sz	(NFS_diropargs_sz+NFS_sattr_sz)
#define NFS_renameargs_sz	(NFS_diropargs_sz+NFS_diropargs_sz)
#define NFS_linkargs_sz		(NFS_fhandle_sz+NFS_diropargs_sz)
#define NFS_symlinkargs_sz	(NFS_diropargs_sz+1+NFS_sattr_sz)
#define NFS_readdirargs_sz	(NFS_fhandle_sz+2)

#define NFS_attrstat_sz		(1+NFS_fattr_sz)
#define NFS_diropres_sz		(1+NFS_fhandle_sz+NFS_fattr_sz)
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#define NFS_readlinkres_sz	(2+1)
#define NFS_readres_sz		(1+NFS_fattr_sz+1+1)
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#define NFS_writeres_sz         (NFS_attrstat_sz)
#define NFS_stat_sz		(1)
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#define NFS_readdirres_sz	(1+1)
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#define NFS_statfsres_sz	(1+NFS_info_sz)

static int nfs_stat_to_errno(enum nfs_stat);

/*
 * Encode/decode NFSv2 basic data types
 *
 * Basic NFSv2 data types are defined in section 2.3 of RFC 1094:
 * "NFS: Network File System Protocol Specification".
 *
 * Not all basic data types have their own encoding and decoding
 * functions.  For run-time efficiency, some data types are encoded
 * or decoded inline.
 */

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static struct user_namespace *rpc_userns(const struct rpc_clnt *clnt)
{
	if (clnt && clnt->cl_cred)
		return clnt->cl_cred->user_ns;
	return &init_user_ns;
}

static struct user_namespace *rpc_rqst_userns(const struct rpc_rqst *rqstp)
{
	if (rqstp->rq_task)
		return rpc_userns(rqstp->rq_task->tk_client);
	return &init_user_ns;
}

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/*
 *	typedef opaque	nfsdata<>;
 */
static int decode_nfsdata(struct xdr_stream *xdr, struct nfs_pgio_res *result)
{
	u32 recvd, count;
	__be32 *p;

	p = xdr_inline_decode(xdr, 4);
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	if (unlikely(!p))
		return -EIO;
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	count = be32_to_cpup(p);
	recvd = xdr_read_pages(xdr, count);
	if (unlikely(count > recvd))
		goto out_cheating;
out:
	result->eof = 0;	/* NFSv2 does not pass EOF flag on the wire. */
	result->count = count;
	return count;
out_cheating:
	dprintk("NFS: server cheating in read result: "
		"count %u > recvd %u\n", count, recvd);
	count = recvd;
	goto out;
}

/*
 *	enum stat {
 *		NFS_OK = 0,
 *		NFSERR_PERM = 1,
 *		NFSERR_NOENT = 2,
 *		NFSERR_IO = 5,
 *		NFSERR_NXIO = 6,
 *		NFSERR_ACCES = 13,
 *		NFSERR_EXIST = 17,
 *		NFSERR_NODEV = 19,
 *		NFSERR_NOTDIR = 20,
 *		NFSERR_ISDIR = 21,
 *		NFSERR_FBIG = 27,
 *		NFSERR_NOSPC = 28,
 *		NFSERR_ROFS = 30,
 *		NFSERR_NAMETOOLONG = 63,
 *		NFSERR_NOTEMPTY = 66,
 *		NFSERR_DQUOT = 69,
 *		NFSERR_STALE = 70,
 *		NFSERR_WFLUSH = 99
 *	};
 */
static int decode_stat(struct xdr_stream *xdr, enum nfs_stat *status)
{
	__be32 *p;

	p = xdr_inline_decode(xdr, 4);
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	if (unlikely(!p))
		return -EIO;
	if (unlikely(*p != cpu_to_be32(NFS_OK)))
		goto out_status;
	*status = 0;
	return 0;
out_status:
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	*status = be32_to_cpup(p);
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	trace_nfs_xdr_status(xdr, (int)*status);
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	return 0;
}

/*
 * 2.3.2.  ftype
 *
 *	enum ftype {
 *		NFNON = 0,
 *		NFREG = 1,
 *		NFDIR = 2,
 *		NFBLK = 3,
 *		NFCHR = 4,
 *		NFLNK = 5
 *	};
 *
 */
static __be32 *xdr_decode_ftype(__be32 *p, u32 *type)
{
	*type = be32_to_cpup(p++);
	if (unlikely(*type > NF2FIFO))
		*type = NFBAD;
	return p;
}

/*
 * 2.3.3.  fhandle
 *
 *	typedef opaque fhandle[FHSIZE];
 */
static void encode_fhandle(struct xdr_stream *xdr, const struct nfs_fh *fh)
{
	__be32 *p;

	p = xdr_reserve_space(xdr, NFS2_FHSIZE);
	memcpy(p, fh->data, NFS2_FHSIZE);
}

static int decode_fhandle(struct xdr_stream *xdr, struct nfs_fh *fh)
{
	__be32 *p;

	p = xdr_inline_decode(xdr, NFS2_FHSIZE);
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	if (unlikely(!p))
		return -EIO;
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	fh->size = NFS2_FHSIZE;
	memcpy(fh->data, p, NFS2_FHSIZE);
	return 0;
}

/*
 * 2.3.4.  timeval
 *
 *	struct timeval {
 *		unsigned int seconds;
 *		unsigned int useconds;
 *	};
 */
static __be32 *xdr_encode_time(__be32 *p, const struct timespec *timep)
{
	*p++ = cpu_to_be32(timep->tv_sec);
	if (timep->tv_nsec != 0)
		*p++ = cpu_to_be32(timep->tv_nsec / NSEC_PER_USEC);
	else
		*p++ = cpu_to_be32(0);
	return p;
}

/*
 * Passing the invalid value useconds=1000000 is a Sun convention for
 * "set to current server time".  It's needed to make permissions checks
 * for the "touch" program across v2 mounts to Solaris and Irix servers
 * work correctly.  See description of sattr in section 6.1 of "NFS
 * Illustrated" by Brent Callaghan, Addison-Wesley, ISBN 0-201-32750-5.
 */
static __be32 *xdr_encode_current_server_time(__be32 *p,
					      const struct timespec *timep)
{
	*p++ = cpu_to_be32(timep->tv_sec);
	*p++ = cpu_to_be32(1000000);
	return p;
}

static __be32 *xdr_decode_time(__be32 *p, struct timespec *timep)
{
	timep->tv_sec = be32_to_cpup(p++);
	timep->tv_nsec = be32_to_cpup(p++) * NSEC_PER_USEC;
	return p;
}

/*
 * 2.3.5.  fattr
 *
 *	struct fattr {
 *		ftype		type;
 *		unsigned int	mode;
 *		unsigned int	nlink;
 *		unsigned int	uid;
 *		unsigned int	gid;
 *		unsigned int	size;
 *		unsigned int	blocksize;
 *		unsigned int	rdev;
 *		unsigned int	blocks;
 *		unsigned int	fsid;
 *		unsigned int	fileid;
 *		timeval		atime;
 *		timeval		mtime;
 *		timeval		ctime;
 *	};
 *
 */
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static int decode_fattr(struct xdr_stream *xdr, struct nfs_fattr *fattr,
		struct user_namespace *userns)
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{
	u32 rdev, type;
	__be32 *p;

	p = xdr_inline_decode(xdr, NFS_fattr_sz << 2);
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	if (unlikely(!p))
		return -EIO;
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	fattr->valid |= NFS_ATTR_FATTR_V2;

	p = xdr_decode_ftype(p, &type);

	fattr->mode = be32_to_cpup(p++);
	fattr->nlink = be32_to_cpup(p++);
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	fattr->uid = make_kuid(userns, be32_to_cpup(p++));
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	if (!uid_valid(fattr->uid))
		goto out_uid;
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	fattr->gid = make_kgid(userns, be32_to_cpup(p++));
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	if (!gid_valid(fattr->gid))
		goto out_gid;
		
	fattr->size = be32_to_cpup(p++);
	fattr->du.nfs2.blocksize = be32_to_cpup(p++);

	rdev = be32_to_cpup(p++);
	fattr->rdev = new_decode_dev(rdev);
	if (type == (u32)NFCHR && rdev == (u32)NFS2_FIFO_DEV) {
		fattr->mode = (fattr->mode & ~S_IFMT) | S_IFIFO;
		fattr->rdev = 0;
	}

	fattr->du.nfs2.blocks = be32_to_cpup(p++);
	fattr->fsid.major = be32_to_cpup(p++);
	fattr->fsid.minor = 0;
	fattr->fileid = be32_to_cpup(p++);

	p = xdr_decode_time(p, &fattr->atime);
	p = xdr_decode_time(p, &fattr->mtime);
	xdr_decode_time(p, &fattr->ctime);
	fattr->change_attr = nfs_timespec_to_change_attr(&fattr->ctime);

	return 0;
out_uid:
	dprintk("NFS: returned invalid uid\n");
	return -EINVAL;
out_gid:
	dprintk("NFS: returned invalid gid\n");
	return -EINVAL;
}

/*
 * 2.3.6.  sattr
 *
 *	struct sattr {
 *		unsigned int	mode;
 *		unsigned int	uid;
 *		unsigned int	gid;
 *		unsigned int	size;
 *		timeval		atime;
 *		timeval		mtime;
 *	};
 */

#define NFS2_SATTR_NOT_SET	(0xffffffff)

static __be32 *xdr_time_not_set(__be32 *p)
{
	*p++ = cpu_to_be32(NFS2_SATTR_NOT_SET);
	*p++ = cpu_to_be32(NFS2_SATTR_NOT_SET);
	return p;
}

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static void encode_sattr(struct xdr_stream *xdr, const struct iattr *attr,
		struct user_namespace *userns)
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{
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	struct timespec ts;
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	__be32 *p;

	p = xdr_reserve_space(xdr, NFS_sattr_sz << 2);

	if (attr->ia_valid & ATTR_MODE)
		*p++ = cpu_to_be32(attr->ia_mode);
	else
		*p++ = cpu_to_be32(NFS2_SATTR_NOT_SET);
	if (attr->ia_valid & ATTR_UID)
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		*p++ = cpu_to_be32(from_kuid_munged(userns, attr->ia_uid));
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	else
		*p++ = cpu_to_be32(NFS2_SATTR_NOT_SET);
	if (attr->ia_valid & ATTR_GID)
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		*p++ = cpu_to_be32(from_kgid_munged(userns, attr->ia_gid));
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	else
		*p++ = cpu_to_be32(NFS2_SATTR_NOT_SET);
	if (attr->ia_valid & ATTR_SIZE)
		*p++ = cpu_to_be32((u32)attr->ia_size);
	else
		*p++ = cpu_to_be32(NFS2_SATTR_NOT_SET);

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	if (attr->ia_valid & ATTR_ATIME_SET) {
		ts = timespec64_to_timespec(attr->ia_atime);
		p = xdr_encode_time(p, &ts);
	} else if (attr->ia_valid & ATTR_ATIME) {
		ts = timespec64_to_timespec(attr->ia_atime);
		p = xdr_encode_current_server_time(p, &ts);
	} else
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		p = xdr_time_not_set(p);
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	if (attr->ia_valid & ATTR_MTIME_SET) {
		ts = timespec64_to_timespec(attr->ia_atime);
		xdr_encode_time(p, &ts);
	} else if (attr->ia_valid & ATTR_MTIME) {
		ts = timespec64_to_timespec(attr->ia_mtime);
		xdr_encode_current_server_time(p, &ts);
	} else
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		xdr_time_not_set(p);
}

/*
 * 2.3.7.  filename
 *
 *	typedef string filename<MAXNAMLEN>;
 */
static void encode_filename(struct xdr_stream *xdr,
			    const char *name, u32 length)
{
	__be32 *p;

	WARN_ON_ONCE(length > NFS2_MAXNAMLEN);
	p = xdr_reserve_space(xdr, 4 + length);
	xdr_encode_opaque(p, name, length);
}

static int decode_filename_inline(struct xdr_stream *xdr,
				  const char **name, u32 *length)
{
	__be32 *p;
	u32 count;

	p = xdr_inline_decode(xdr, 4);
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	if (unlikely(!p))
		return -EIO;
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	count = be32_to_cpup(p);
	if (count > NFS3_MAXNAMLEN)
		goto out_nametoolong;
	p = xdr_inline_decode(xdr, count);
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	if (unlikely(!p))
		return -EIO;
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	*name = (const char *)p;
	*length = count;
	return 0;
out_nametoolong:
	dprintk("NFS: returned filename too long: %u\n", count);
	return -ENAMETOOLONG;
}

/*
 * 2.3.8.  path
 *
 *	typedef string path<MAXPATHLEN>;
 */
static void encode_path(struct xdr_stream *xdr, struct page **pages, u32 length)
{
	__be32 *p;

	p = xdr_reserve_space(xdr, 4);
	*p = cpu_to_be32(length);
	xdr_write_pages(xdr, pages, 0, length);
}

static int decode_path(struct xdr_stream *xdr)
{
	u32 length, recvd;
	__be32 *p;

	p = xdr_inline_decode(xdr, 4);
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	if (unlikely(!p))
		return -EIO;
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	length = be32_to_cpup(p);
	if (unlikely(length >= xdr->buf->page_len || length > NFS_MAXPATHLEN))
		goto out_size;
	recvd = xdr_read_pages(xdr, length);
	if (unlikely(length > recvd))
		goto out_cheating;
	xdr_terminate_string(xdr->buf, length);
	return 0;
out_size:
	dprintk("NFS: returned pathname too long: %u\n", length);
	return -ENAMETOOLONG;
out_cheating:
	dprintk("NFS: server cheating in pathname result: "
		"length %u > received %u\n", length, recvd);
	return -EIO;
}

/*
 * 2.3.9.  attrstat
 *
 *	union attrstat switch (stat status) {
 *	case NFS_OK:
 *		fattr attributes;
 *	default:
 *		void;
 *	};
 */
static int decode_attrstat(struct xdr_stream *xdr, struct nfs_fattr *result,
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			   __u32 *op_status,
			   struct user_namespace *userns)
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{
	enum nfs_stat status;
	int error;

	error = decode_stat(xdr, &status);
	if (unlikely(error))
		goto out;
	if (op_status)
		*op_status = status;
	if (status != NFS_OK)
		goto out_default;
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	error = decode_fattr(xdr, result, userns);
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out:
	return error;
out_default:
	return nfs_stat_to_errno(status);
}

/*
 * 2.3.10.  diropargs
 *
 *	struct diropargs {
 *		fhandle  dir;
 *		filename name;
 *	};
 */
static void encode_diropargs(struct xdr_stream *xdr, const struct nfs_fh *fh,
			     const char *name, u32 length)
{
	encode_fhandle(xdr, fh);
	encode_filename(xdr, name, length);
}

/*
 * 2.3.11.  diropres
 *
 *	union diropres switch (stat status) {
 *	case NFS_OK:
 *		struct {
 *			fhandle file;
 *			fattr   attributes;
 *		} diropok;
 *	default:
 *		void;
 *	};
 */
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static int decode_diropok(struct xdr_stream *xdr, struct nfs_diropok *result,
		struct user_namespace *userns)
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{
	int error;

	error = decode_fhandle(xdr, result->fh);
	if (unlikely(error))
		goto out;
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	error = decode_fattr(xdr, result->fattr, userns);
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out:
	return error;
}

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static int decode_diropres(struct xdr_stream *xdr, struct nfs_diropok *result,
		struct user_namespace *userns)
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{
	enum nfs_stat status;
	int error;

	error = decode_stat(xdr, &status);
	if (unlikely(error))
		goto out;
	if (status != NFS_OK)
		goto out_default;
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	error = decode_diropok(xdr, result, userns);
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out:
	return error;
out_default:
	return nfs_stat_to_errno(status);
}


/*
 * NFSv2 XDR encode functions
 *
 * NFSv2 argument types are defined in section 2.2 of RFC 1094:
 * "NFS: Network File System Protocol Specification".
 */

static void nfs2_xdr_enc_fhandle(struct rpc_rqst *req,
				 struct xdr_stream *xdr,
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				 const void *data)
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{
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	const struct nfs_fh *fh = data;

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	encode_fhandle(xdr, fh);
}

/*
 * 2.2.3.  sattrargs
 *
 *	struct sattrargs {
 *		fhandle file;
 *		sattr attributes;
 *	};
 */
static void nfs2_xdr_enc_sattrargs(struct rpc_rqst *req,
				   struct xdr_stream *xdr,
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				   const void *data)
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{
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	const struct nfs_sattrargs *args = data;

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	encode_fhandle(xdr, args->fh);
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	encode_sattr(xdr, args->sattr, rpc_rqst_userns(req));
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}

static void nfs2_xdr_enc_diropargs(struct rpc_rqst *req,
				   struct xdr_stream *xdr,
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				   const void *data)
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{
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	const struct nfs_diropargs *args = data;

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	encode_diropargs(xdr, args->fh, args->name, args->len);
}

static void nfs2_xdr_enc_readlinkargs(struct rpc_rqst *req,
				      struct xdr_stream *xdr,
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				      const void *data)
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{
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	const struct nfs_readlinkargs *args = data;

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	encode_fhandle(xdr, args->fh);
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	rpc_prepare_reply_pages(req, args->pages, args->pgbase,
				args->pglen, NFS_readlinkres_sz);
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}

/*
 * 2.2.7.  readargs
 *
 *	struct readargs {
 *		fhandle file;
 *		unsigned offset;
 *		unsigned count;
 *		unsigned totalcount;
 *	};
 */
static void encode_readargs(struct xdr_stream *xdr,
			    const struct nfs_pgio_args *args)
{
	u32 offset = args->offset;
	u32 count = args->count;
	__be32 *p;

	encode_fhandle(xdr, args->fh);

	p = xdr_reserve_space(xdr, 4 + 4 + 4);
	*p++ = cpu_to_be32(offset);
	*p++ = cpu_to_be32(count);
	*p = cpu_to_be32(count);
}

static void nfs2_xdr_enc_readargs(struct rpc_rqst *req,
				  struct xdr_stream *xdr,
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				  const void *data)
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{
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	const struct nfs_pgio_args *args = data;

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	encode_readargs(xdr, args);
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	rpc_prepare_reply_pages(req, args->pages, args->pgbase,
				args->count, NFS_readres_sz);
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	req->rq_rcv_buf.flags |= XDRBUF_READ;
}

/*
 * 2.2.9.  writeargs
 *
 *	struct writeargs {
 *		fhandle file;
 *		unsigned beginoffset;
 *		unsigned offset;
 *		unsigned totalcount;
 *		nfsdata data;
 *	};
 */
static void encode_writeargs(struct xdr_stream *xdr,
			     const struct nfs_pgio_args *args)
{
	u32 offset = args->offset;
	u32 count = args->count;
	__be32 *p;

	encode_fhandle(xdr, args->fh);

	p = xdr_reserve_space(xdr, 4 + 4 + 4 + 4);
	*p++ = cpu_to_be32(offset);
	*p++ = cpu_to_be32(offset);
	*p++ = cpu_to_be32(count);

	/* nfsdata */
	*p = cpu_to_be32(count);
	xdr_write_pages(xdr, args->pages, args->pgbase, count);
}

static void nfs2_xdr_enc_writeargs(struct rpc_rqst *req,
				   struct xdr_stream *xdr,
673
				   const void *data)
674
{
675 676
	const struct nfs_pgio_args *args = data;

677 678 679 680 681 682 683 684 685 686 687 688 689 690
	encode_writeargs(xdr, args);
	xdr->buf->flags |= XDRBUF_WRITE;
}

/*
 * 2.2.10.  createargs
 *
 *	struct createargs {
 *		diropargs where;
 *		sattr attributes;
 *	};
 */
static void nfs2_xdr_enc_createargs(struct rpc_rqst *req,
				    struct xdr_stream *xdr,
691
				    const void *data)
692
{
693 694
	const struct nfs_createargs *args = data;

695
	encode_diropargs(xdr, args->fh, args->name, args->len);
696
	encode_sattr(xdr, args->sattr, rpc_rqst_userns(req));
697 698 699 700
}

static void nfs2_xdr_enc_removeargs(struct rpc_rqst *req,
				    struct xdr_stream *xdr,
701
				    const void *data)
702
{
703 704
	const struct nfs_removeargs *args = data;

705 706 707 708 709 710 711 712 713 714 715 716 717
	encode_diropargs(xdr, args->fh, args->name.name, args->name.len);
}

/*
 * 2.2.12.  renameargs
 *
 *	struct renameargs {
 *		diropargs from;
 *		diropargs to;
 *	};
 */
static void nfs2_xdr_enc_renameargs(struct rpc_rqst *req,
				    struct xdr_stream *xdr,
718
				    const void *data)
719
{
720
	const struct nfs_renameargs *args = data;
721 722 723 724 725 726 727 728 729 730 731 732 733 734 735 736 737
	const struct qstr *old = args->old_name;
	const struct qstr *new = args->new_name;

	encode_diropargs(xdr, args->old_dir, old->name, old->len);
	encode_diropargs(xdr, args->new_dir, new->name, new->len);
}

/*
 * 2.2.13.  linkargs
 *
 *	struct linkargs {
 *		fhandle from;
 *		diropargs to;
 *	};
 */
static void nfs2_xdr_enc_linkargs(struct rpc_rqst *req,
				  struct xdr_stream *xdr,
738
				  const void *data)
739
{
740 741
	const struct nfs_linkargs *args = data;

742 743 744 745 746 747 748 749 750 751 752 753 754 755 756
	encode_fhandle(xdr, args->fromfh);
	encode_diropargs(xdr, args->tofh, args->toname, args->tolen);
}

/*
 * 2.2.14.  symlinkargs
 *
 *	struct symlinkargs {
 *		diropargs from;
 *		path to;
 *		sattr attributes;
 *	};
 */
static void nfs2_xdr_enc_symlinkargs(struct rpc_rqst *req,
				     struct xdr_stream *xdr,
757
				     const void *data)
758
{
759 760
	const struct nfs_symlinkargs *args = data;

761 762
	encode_diropargs(xdr, args->fromfh, args->fromname, args->fromlen);
	encode_path(xdr, args->pages, args->pathlen);
763
	encode_sattr(xdr, args->sattr, rpc_rqst_userns(req));
764 765 766 767 768 769 770 771 772 773 774 775 776 777 778 779 780 781 782 783 784 785 786 787 788
}

/*
 * 2.2.17.  readdirargs
 *
 *	struct readdirargs {
 *		fhandle dir;
 *		nfscookie cookie;
 *		unsigned count;
 *	};
 */
static void encode_readdirargs(struct xdr_stream *xdr,
			       const struct nfs_readdirargs *args)
{
	__be32 *p;

	encode_fhandle(xdr, args->fh);

	p = xdr_reserve_space(xdr, 4 + 4);
	*p++ = cpu_to_be32(args->cookie);
	*p = cpu_to_be32(args->count);
}

static void nfs2_xdr_enc_readdirargs(struct rpc_rqst *req,
				     struct xdr_stream *xdr,
789
				     const void *data)
790
{
791 792
	const struct nfs_readdirargs *args = data;

793
	encode_readdirargs(xdr, args);
794 795
	rpc_prepare_reply_pages(req, args->pages, 0,
				args->count, NFS_readdirres_sz);
796 797 798 799 800 801 802 803 804 805 806 807 808 809 810 811 812 813 814 815 816 817 818 819 820 821 822
}

/*
 * NFSv2 XDR decode functions
 *
 * NFSv2 result types are defined in section 2.2 of RFC 1094:
 * "NFS: Network File System Protocol Specification".
 */

static int nfs2_xdr_dec_stat(struct rpc_rqst *req, struct xdr_stream *xdr,
			     void *__unused)
{
	enum nfs_stat status;
	int error;

	error = decode_stat(xdr, &status);
	if (unlikely(error))
		goto out;
	if (status != NFS_OK)
		goto out_default;
out:
	return error;
out_default:
	return nfs_stat_to_errno(status);
}

static int nfs2_xdr_dec_attrstat(struct rpc_rqst *req, struct xdr_stream *xdr,
823
				 void *result)
824
{
825
	return decode_attrstat(xdr, result, NULL, rpc_rqst_userns(req));
826 827 828
}

static int nfs2_xdr_dec_diropres(struct rpc_rqst *req, struct xdr_stream *xdr,
829
				 void *result)
830
{
831
	return decode_diropres(xdr, result, rpc_rqst_userns(req));
832 833 834 835 836 837 838 839 840 841 842 843 844 845 846 847 848 849 850 851 852 853 854 855 856 857 858 859 860 861 862 863 864 865 866 867 868 869 870 871 872 873
}

/*
 * 2.2.6.  readlinkres
 *
 *	union readlinkres switch (stat status) {
 *	case NFS_OK:
 *		path data;
 *	default:
 *		void;
 *	};
 */
static int nfs2_xdr_dec_readlinkres(struct rpc_rqst *req,
				    struct xdr_stream *xdr, void *__unused)
{
	enum nfs_stat status;
	int error;

	error = decode_stat(xdr, &status);
	if (unlikely(error))
		goto out;
	if (status != NFS_OK)
		goto out_default;
	error = decode_path(xdr);
out:
	return error;
out_default:
	return nfs_stat_to_errno(status);
}

/*
 * 2.2.7.  readres
 *
 *	union readres switch (stat status) {
 *	case NFS_OK:
 *		fattr attributes;
 *		nfsdata data;
 *	default:
 *		void;
 *	};
 */
static int nfs2_xdr_dec_readres(struct rpc_rqst *req, struct xdr_stream *xdr,
874
				void *data)
875
{
876
	struct nfs_pgio_res *result = data;
877 878 879 880 881 882 883 884 885
	enum nfs_stat status;
	int error;

	error = decode_stat(xdr, &status);
	if (unlikely(error))
		goto out;
	result->op_status = status;
	if (status != NFS_OK)
		goto out_default;
886
	error = decode_fattr(xdr, result->fattr, rpc_rqst_userns(req));
887 888 889 890 891 892 893 894 895 896
	if (unlikely(error))
		goto out;
	error = decode_nfsdata(xdr, result);
out:
	return error;
out_default:
	return nfs_stat_to_errno(status);
}

static int nfs2_xdr_dec_writeres(struct rpc_rqst *req, struct xdr_stream *xdr,
897
				 void *data)
898
{
899 900
	struct nfs_pgio_res *result = data;

901 902
	/* All NFSv2 writes are "file sync" writes */
	result->verf->committed = NFS_FILE_SYNC;
903 904
	return decode_attrstat(xdr, result->fattr, &result->op_status,
			rpc_rqst_userns(req));
905 906 907 908 909 910 911 912 913 914 915 916 917 918 919 920 921 922 923 924 925 926 927 928 929 930
}

/**
 * nfs2_decode_dirent - Decode a single NFSv2 directory entry stored in
 *                      the local page cache.
 * @xdr: XDR stream where entry resides
 * @entry: buffer to fill in with entry data
 * @plus: boolean indicating whether this should be a readdirplus entry
 *
 * Returns zero if successful, otherwise a negative errno value is
 * returned.
 *
 * This function is not invoked during READDIR reply decoding, but
 * rather whenever an application invokes the getdents(2) system call
 * on a directory already in our cache.
 *
 * 2.2.17.  entry
 *
 *	struct entry {
 *		unsigned	fileid;
 *		filename	name;
 *		nfscookie	cookie;
 *		entry		*nextentry;
 *	};
 */
int nfs2_decode_dirent(struct xdr_stream *xdr, struct nfs_entry *entry,
931
		       bool plus)
932 933 934 935 936
{
	__be32 *p;
	int error;

	p = xdr_inline_decode(xdr, 4);
937 938
	if (unlikely(!p))
		return -EAGAIN;
939 940
	if (*p++ == xdr_zero) {
		p = xdr_inline_decode(xdr, 4);
941 942
		if (unlikely(!p))
			return -EAGAIN;
943 944 945 946 947 948 949
		if (*p++ == xdr_zero)
			return -EAGAIN;
		entry->eof = 1;
		return -EBADCOOKIE;
	}

	p = xdr_inline_decode(xdr, 4);
950 951
	if (unlikely(!p))
		return -EAGAIN;
952 953 954 955 956 957 958 959 960 961 962 963
	entry->ino = be32_to_cpup(p);

	error = decode_filename_inline(xdr, &entry->name, &entry->len);
	if (unlikely(error))
		return error;

	/*
	 * The type (size and byte order) of nfscookie isn't defined in
	 * RFC 1094.  This implementation assumes that it's an XDR uint32.
	 */
	entry->prev_cookie = entry->cookie;
	p = xdr_inline_decode(xdr, 4);
964 965
	if (unlikely(!p))
		return -EAGAIN;
966 967 968 969 970 971 972 973 974 975 976 977 978 979 980 981 982 983 984 985 986 987 988 989 990 991 992 993 994 995 996 997 998 999 1000 1001 1002 1003 1004 1005 1006 1007 1008 1009 1010 1011 1012 1013 1014 1015 1016 1017 1018 1019 1020 1021 1022 1023 1024 1025 1026 1027 1028 1029 1030 1031 1032 1033
	entry->cookie = be32_to_cpup(p);

	entry->d_type = DT_UNKNOWN;

	return 0;
}

/*
 * 2.2.17.  readdirres
 *
 *	union readdirres switch (stat status) {
 *	case NFS_OK:
 *		struct {
 *			entry *entries;
 *			bool eof;
 *		} readdirok;
 *	default:
 *		void;
 *	};
 *
 * Read the directory contents into the page cache, but don't
 * touch them.  The actual decoding is done by nfs2_decode_dirent()
 * during subsequent nfs_readdir() calls.
 */
static int decode_readdirok(struct xdr_stream *xdr)
{
	return xdr_read_pages(xdr, xdr->buf->page_len);
}

static int nfs2_xdr_dec_readdirres(struct rpc_rqst *req,
				   struct xdr_stream *xdr, void *__unused)
{
	enum nfs_stat status;
	int error;

	error = decode_stat(xdr, &status);
	if (unlikely(error))
		goto out;
	if (status != NFS_OK)
		goto out_default;
	error = decode_readdirok(xdr);
out:
	return error;
out_default:
	return nfs_stat_to_errno(status);
}

/*
 * 2.2.18.  statfsres
 *
 *	union statfsres (stat status) {
 *	case NFS_OK:
 *		struct {
 *			unsigned tsize;
 *			unsigned bsize;
 *			unsigned blocks;
 *			unsigned bfree;
 *			unsigned bavail;
 *		} info;
 *	default:
 *		void;
 *	};
 */
static int decode_info(struct xdr_stream *xdr, struct nfs2_fsstat *result)
{
	__be32 *p;

	p = xdr_inline_decode(xdr, NFS_info_sz << 2);
1034 1035
	if (unlikely(!p))
		return -EIO;
1036 1037 1038 1039 1040 1041 1042 1043 1044
	result->tsize  = be32_to_cpup(p++);
	result->bsize  = be32_to_cpup(p++);
	result->blocks = be32_to_cpup(p++);
	result->bfree  = be32_to_cpup(p++);
	result->bavail = be32_to_cpup(p);
	return 0;
}

static int nfs2_xdr_dec_statfsres(struct rpc_rqst *req, struct xdr_stream *xdr,
1045
				  void *result)
1046 1047 1048 1049 1050 1051 1052 1053 1054 1055 1056 1057 1058 1059 1060 1061 1062 1063 1064 1065 1066 1067 1068 1069 1070 1071 1072 1073 1074 1075 1076 1077 1078 1079 1080 1081 1082 1083 1084 1085 1086 1087 1088 1089 1090 1091 1092 1093 1094 1095 1096 1097 1098 1099 1100 1101 1102 1103 1104 1105 1106 1107 1108 1109 1110 1111 1112 1113 1114 1115 1116 1117 1118 1119 1120 1121 1122 1123 1124 1125 1126 1127 1128
{
	enum nfs_stat status;
	int error;

	error = decode_stat(xdr, &status);
	if (unlikely(error))
		goto out;
	if (status != NFS_OK)
		goto out_default;
	error = decode_info(xdr, result);
out:
	return error;
out_default:
	return nfs_stat_to_errno(status);
}


/*
 * We need to translate between nfs status return values and
 * the local errno values which may not be the same.
 */
static const struct {
	int stat;
	int errno;
} nfs_errtbl[] = {
	{ NFS_OK,		0		},
	{ NFSERR_PERM,		-EPERM		},
	{ NFSERR_NOENT,		-ENOENT		},
	{ NFSERR_IO,		-errno_NFSERR_IO},
	{ NFSERR_NXIO,		-ENXIO		},
/*	{ NFSERR_EAGAIN,	-EAGAIN		}, */
	{ NFSERR_ACCES,		-EACCES		},
	{ NFSERR_EXIST,		-EEXIST		},
	{ NFSERR_XDEV,		-EXDEV		},
	{ NFSERR_NODEV,		-ENODEV		},
	{ NFSERR_NOTDIR,	-ENOTDIR	},
	{ NFSERR_ISDIR,		-EISDIR		},
	{ NFSERR_INVAL,		-EINVAL		},
	{ NFSERR_FBIG,		-EFBIG		},
	{ NFSERR_NOSPC,		-ENOSPC		},
	{ NFSERR_ROFS,		-EROFS		},
	{ NFSERR_MLINK,		-EMLINK		},
	{ NFSERR_NAMETOOLONG,	-ENAMETOOLONG	},
	{ NFSERR_NOTEMPTY,	-ENOTEMPTY	},
	{ NFSERR_DQUOT,		-EDQUOT		},
	{ NFSERR_STALE,		-ESTALE		},
	{ NFSERR_REMOTE,	-EREMOTE	},
#ifdef EWFLUSH
	{ NFSERR_WFLUSH,	-EWFLUSH	},
#endif
	{ NFSERR_BADHANDLE,	-EBADHANDLE	},
	{ NFSERR_NOT_SYNC,	-ENOTSYNC	},
	{ NFSERR_BAD_COOKIE,	-EBADCOOKIE	},
	{ NFSERR_NOTSUPP,	-ENOTSUPP	},
	{ NFSERR_TOOSMALL,	-ETOOSMALL	},
	{ NFSERR_SERVERFAULT,	-EREMOTEIO	},
	{ NFSERR_BADTYPE,	-EBADTYPE	},
	{ NFSERR_JUKEBOX,	-EJUKEBOX	},
	{ -1,			-EIO		}
};

/**
 * nfs_stat_to_errno - convert an NFS status code to a local errno
 * @status: NFS status code to convert
 *
 * Returns a local errno value, or -EIO if the NFS status code is
 * not recognized.  This function is used jointly by NFSv2 and NFSv3.
 */
static int nfs_stat_to_errno(enum nfs_stat status)
{
	int i;

	for (i = 0; nfs_errtbl[i].stat != -1; i++) {
		if (nfs_errtbl[i].stat == (int)status)
			return nfs_errtbl[i].errno;
	}
	dprintk("NFS: Unrecognized nfs status value: %u\n", status);
	return nfs_errtbl[i].errno;
}

#define PROC(proc, argtype, restype, timer)				\
[NFSPROC_##proc] = {							\
	.p_proc	    =  NFSPROC_##proc,					\
1129 1130
	.p_encode   =  nfs2_xdr_enc_##argtype,				\
	.p_decode   =  nfs2_xdr_dec_##restype,				\
1131 1132 1133 1134 1135 1136
	.p_arglen   =  NFS_##argtype##_sz,				\
	.p_replen   =  NFS_##restype##_sz,				\
	.p_timer    =  timer,						\
	.p_statidx  =  NFSPROC_##proc,					\
	.p_name     =  #proc,						\
	}
1137
const struct rpc_procinfo nfs_procedures[] = {
1138 1139 1140 1141 1142 1143 1144 1145 1146 1147 1148 1149 1150 1151 1152 1153 1154
	PROC(GETATTR,	fhandle,	attrstat,	1),
	PROC(SETATTR,	sattrargs,	attrstat,	0),
	PROC(LOOKUP,	diropargs,	diropres,	2),
	PROC(READLINK,	readlinkargs,	readlinkres,	3),
	PROC(READ,	readargs,	readres,	3),
	PROC(WRITE,	writeargs,	writeres,	4),
	PROC(CREATE,	createargs,	diropres,	0),
	PROC(REMOVE,	removeargs,	stat,		0),
	PROC(RENAME,	renameargs,	stat,		0),
	PROC(LINK,	linkargs,	stat,		0),
	PROC(SYMLINK,	symlinkargs,	stat,		0),
	PROC(MKDIR,	createargs,	diropres,	0),
	PROC(RMDIR,	diropargs,	stat,		0),
	PROC(READDIR,	readdirargs,	readdirres,	3),
	PROC(STATFS,	fhandle,	statfsres,	0),
};

1155
static unsigned int nfs_version2_counts[ARRAY_SIZE(nfs_procedures)];
1156 1157 1158
const struct rpc_version nfs_version2 = {
	.number			= 2,
	.nrprocs		= ARRAY_SIZE(nfs_procedures),
1159 1160
	.procs			= nfs_procedures,
	.counts			= nfs_version2_counts,
1161
};