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

// SPDX-License-Identifier: GPL-2.0
/*
 * XDR support for nfsd
 *
 * Copyright (C) 1995, 1996 Olaf Kirch <okir@monad.swb.de>
 */

#include "vfs.h"
#include "xdr.h"
#include "auth.h"

/*
 * Mapping of S_IF* types to NFS file types
 */
static const u32 nfs_ftypes[] = {
	NFNON,  NFCHR,  NFCHR, NFBAD,
	NFDIR,  NFBAD,  NFBLK, NFBAD,
	NFREG,  NFBAD,  NFLNK, NFBAD,
	NFSOCK, NFBAD,  NFLNK, NFBAD,
};


/*
 * Basic NFSv2 data types (RFC 1094 Section 2.3)
 */

/**
 * svcxdr_encode_stat - Encode an NFSv2 status code
 * @xdr: XDR stream
 * @status: status value to encode
 *
 * Return values:
 *   %false: Send buffer space was exhausted
 *   %true: Success
 */
bool
svcxdr_encode_stat(struct xdr_stream *xdr, __be32 status)
{
	__be32 *p;

	p = xdr_reserve_space(xdr, sizeof(status));
	if (!p)
		return false;
	*p = status;

	return true;
}

/**
 * svcxdr_decode_fhandle - Decode an NFSv2 file handle
 * @xdr: XDR stream positioned at an encoded NFSv2 FH
 * @fhp: OUT: filled-in server file handle
 *
 * Return values:
 *  %false: The encoded file handle was not valid
 *  %true: @fhp has been initialized
 */
bool
svcxdr_decode_fhandle(struct xdr_stream *xdr, struct svc_fh *fhp)
{
	__be32 *p;

	p = xdr_inline_decode(xdr, NFS_FHSIZE);
	if (!p)
		return false;
	fh_init(fhp, NFS_FHSIZE);
	memcpy(&fhp->fh_handle.fh_raw, p, NFS_FHSIZE);
	fhp->fh_handle.fh_size = NFS_FHSIZE;

	return true;
}

static bool
svcxdr_encode_fhandle(struct xdr_stream *xdr, const struct svc_fh *fhp)
{
	__be32 *p;

	p = xdr_reserve_space(xdr, NFS_FHSIZE);
	if (!p)
		return false;
	memcpy(p, &fhp->fh_handle.fh_raw, NFS_FHSIZE);

	return true;
}

static __be32 *
encode_timeval(__be32 *p, const struct timespec64 *time)
{
	*p++ = cpu_to_be32((u32)time->tv_sec);
	if (time->tv_nsec)
		*p++ = cpu_to_be32(time->tv_nsec / NSEC_PER_USEC);
	else
		*p++ = xdr_zero;
	return p;
}

static bool
svcxdr_decode_filename(struct xdr_stream *xdr, char **name, unsigned int *len)
{
	u32 size, i;
	__be32 *p;
	char *c;

	if (xdr_stream_decode_u32(xdr, &size) < 0)
		return false;
	if (size == 0 || size > NFS_MAXNAMLEN)
		return false;
	p = xdr_inline_decode(xdr, size);
	if (!p)
		return false;

	*len = size;
	*name = (char *)p;
	for (i = 0, c = *name; i < size; i++, c++)
		if (*c == '\0' || *c == '/')
			return false;

	return true;
}

static bool
svcxdr_decode_diropargs(struct xdr_stream *xdr, struct svc_fh *fhp,
			char **name, unsigned int *len)
{
	return svcxdr_decode_fhandle(xdr, fhp) &&
		svcxdr_decode_filename(xdr, name, len);
}

static bool
svcxdr_decode_sattr(struct svc_rqst *rqstp, struct xdr_stream *xdr,
		    struct iattr *iap)
{
	u32 tmp1, tmp2;
	__be32 *p;

	p = xdr_inline_decode(xdr, XDR_UNIT * 8);
	if (!p)
		return false;

	iap->ia_valid = 0;

	/*
	 * Some Sun clients put 0xffff in the mode field when they
	 * mean 0xffffffff.
	 */
	tmp1 = be32_to_cpup(p++);
	if (tmp1 != (u32)-1 && tmp1 != 0xffff) {
		iap->ia_valid |= ATTR_MODE;
		iap->ia_mode = tmp1;
	}

	tmp1 = be32_to_cpup(p++);
	if (tmp1 != (u32)-1) {
		iap->ia_uid = make_kuid(nfsd_user_namespace(rqstp), tmp1);
		if (uid_valid(iap->ia_uid))
			iap->ia_valid |= ATTR_UID;
	}

	tmp1 = be32_to_cpup(p++);
	if (tmp1 != (u32)-1) {
		iap->ia_gid = make_kgid(nfsd_user_namespace(rqstp), tmp1);
		if (gid_valid(iap->ia_gid))
			iap->ia_valid |= ATTR_GID;
	}

	tmp1 = be32_to_cpup(p++);
	if (tmp1 != (u32)-1) {
		iap->ia_valid |= ATTR_SIZE;
		iap->ia_size = tmp1;
	}

	tmp1 = be32_to_cpup(p++);
	tmp2 = be32_to_cpup(p++);
	if (tmp1 != (u32)-1 && tmp2 != (u32)-1) {
		iap->ia_valid |= ATTR_ATIME | ATTR_ATIME_SET;
		iap->ia_atime.tv_sec = tmp1;
		iap->ia_atime.tv_nsec = tmp2 * NSEC_PER_USEC;
	}

	tmp1 = be32_to_cpup(p++);
	tmp2 = be32_to_cpup(p++);
	if (tmp1 != (u32)-1 && tmp2 != (u32)-1) {
		iap->ia_valid |= ATTR_MTIME | ATTR_MTIME_SET;
		iap->ia_mtime.tv_sec = tmp1;
		iap->ia_mtime.tv_nsec = tmp2 * NSEC_PER_USEC;
		/*
		 * Passing the invalid value useconds=1000000 for mtime
		 * is a Sun convention for "set both mtime and atime to
		 * current server time".  It's needed to make permissions
		 * checks for the "touch" program across v2 mounts to
		 * Solaris and Irix boxes work correctly. See description of
		 * sattr in section 6.1 of "NFS Illustrated" by
		 * Brent Callaghan, Addison-Wesley, ISBN 0-201-32750-5
		 */
		if (tmp2 == 1000000)
			iap->ia_valid &= ~(ATTR_ATIME_SET|ATTR_MTIME_SET);
	}

	return true;
}

/**
 * svcxdr_encode_fattr - Encode NFSv2 file attributes
 * @rqstp: Context of a completed RPC transaction
 * @xdr: XDR stream
 * @fhp: File handle to encode
 * @stat: Attributes to encode
 *
 * Return values:
 *   %false: Send buffer space was exhausted
 *   %true: Success
 */
bool
svcxdr_encode_fattr(struct svc_rqst *rqstp, struct xdr_stream *xdr,
		    const struct svc_fh *fhp, const struct kstat *stat)
{
	struct user_namespace *userns = nfsd_user_namespace(rqstp);
	struct dentry *dentry = fhp->fh_dentry;
	int type = stat->mode & S_IFMT;
	struct timespec64 time;
	__be32 *p;
	u32 fsid;

	p = xdr_reserve_space(xdr, XDR_UNIT * 17);
	if (!p)
		return false;

	*p++ = cpu_to_be32(nfs_ftypes[type >> 12]);
	*p++ = cpu_to_be32((u32)stat->mode);
	*p++ = cpu_to_be32((u32)stat->nlink);
	*p++ = cpu_to_be32((u32)from_kuid_munged(userns, stat->uid));
	*p++ = cpu_to_be32((u32)from_kgid_munged(userns, stat->gid));

	if (S_ISLNK(type) && stat->size > NFS_MAXPATHLEN)
		*p++ = cpu_to_be32(NFS_MAXPATHLEN);
	else
		*p++ = cpu_to_be32((u32) stat->size);
	*p++ = cpu_to_be32((u32) stat->blksize);
	if (S_ISCHR(type) || S_ISBLK(type))
		*p++ = cpu_to_be32(new_encode_dev(stat->rdev));
	else
		*p++ = cpu_to_be32(0xffffffff);
	*p++ = cpu_to_be32((u32)stat->blocks);

	switch (fsid_source(fhp)) {
	case FSIDSOURCE_FSID:
		fsid = (u32)fhp->fh_export->ex_fsid;
		break;
	case FSIDSOURCE_UUID:
		fsid = ((u32 *)fhp->fh_export->ex_uuid)[0];
		fsid ^= ((u32 *)fhp->fh_export->ex_uuid)[1];
		fsid ^= ((u32 *)fhp->fh_export->ex_uuid)[2];
		fsid ^= ((u32 *)fhp->fh_export->ex_uuid)[3];
		break;
	default:
		fsid = new_encode_dev(stat->dev);
		break;
	}
	*p++ = cpu_to_be32(fsid);

	*p++ = cpu_to_be32((u32)stat->ino);
	p = encode_timeval(p, &stat->atime);
	time = stat->mtime;
	lease_get_mtime(d_inode(dentry), &time);
	p = encode_timeval(p, &time);
	encode_timeval(p, &stat->ctime);

	return true;
}

/*
 * XDR decode functions
 */

bool
nfssvc_decode_fhandleargs(struct svc_rqst *rqstp, struct xdr_stream *xdr)
{
	struct nfsd_fhandle *args = rqstp->rq_argp;

	return svcxdr_decode_fhandle(xdr, &args->fh);
}

bool
nfssvc_decode_sattrargs(struct svc_rqst *rqstp, struct xdr_stream *xdr)
{
	struct nfsd_sattrargs *args = rqstp->rq_argp;

	return svcxdr_decode_fhandle(xdr, &args->fh) &&
		svcxdr_decode_sattr(rqstp, xdr, &args->attrs);
}

bool
nfssvc_decode_diropargs(struct svc_rqst *rqstp, struct xdr_stream *xdr)
{
	struct nfsd_diropargs *args = rqstp->rq_argp;

	return svcxdr_decode_diropargs(xdr, &args->fh, &args->name, &args->len);
}

bool
nfssvc_decode_readargs(struct svc_rqst *rqstp, struct xdr_stream *xdr)
{
	struct nfsd_readargs *args = rqstp->rq_argp;
	u32 totalcount;

	if (!svcxdr_decode_fhandle(xdr, &args->fh))
		return false;
	if (xdr_stream_decode_u32(xdr, &args->offset) < 0)
		return false;
	if (xdr_stream_decode_u32(xdr, &args->count) < 0)
		return false;
	/* totalcount is ignored */
	if (xdr_stream_decode_u32(xdr, &totalcount) < 0)
		return false;

	return true;
}

bool
nfssvc_decode_writeargs(struct svc_rqst *rqstp, struct xdr_stream *xdr)
{
	struct nfsd_writeargs *args = rqstp->rq_argp;
	u32 beginoffset, totalcount;

	if (!svcxdr_decode_fhandle(xdr, &args->fh))
		return false;
	/* beginoffset is ignored */
	if (xdr_stream_decode_u32(xdr, &beginoffset) < 0)
		return false;
	if (xdr_stream_decode_u32(xdr, &args->offset) < 0)
		return false;
	/* totalcount is ignored */
	if (xdr_stream_decode_u32(xdr, &totalcount) < 0)
		return false;

	/* opaque data */
	if (xdr_stream_decode_u32(xdr, &args->len) < 0)
		return false;
	if (args->len > NFS_MAXDATA)
		return false;

	return xdr_stream_subsegment(xdr, &args->payload, args->len);
}

bool
nfssvc_decode_createargs(struct svc_rqst *rqstp, struct xdr_stream *xdr)
{
	struct nfsd_createargs *args = rqstp->rq_argp;

	return svcxdr_decode_diropargs(xdr, &args->fh,
				       &args->name, &args->len) &&
		svcxdr_decode_sattr(rqstp, xdr, &args->attrs);
}

bool
nfssvc_decode_renameargs(struct svc_rqst *rqstp, struct xdr_stream *xdr)
{
	struct nfsd_renameargs *args = rqstp->rq_argp;

	return svcxdr_decode_diropargs(xdr, &args->ffh,
				       &args->fname, &args->flen) &&
		svcxdr_decode_diropargs(xdr, &args->tfh,
					&args->tname, &args->tlen);
}

bool
nfssvc_decode_linkargs(struct svc_rqst *rqstp, struct xdr_stream *xdr)
{
	struct nfsd_linkargs *args = rqstp->rq_argp;

	return svcxdr_decode_fhandle(xdr, &args->ffh) &&
		svcxdr_decode_diropargs(xdr, &args->tfh,
					&args->tname, &args->tlen);
}

bool
nfssvc_decode_symlinkargs(struct svc_rqst *rqstp, struct xdr_stream *xdr)
{
	struct nfsd_symlinkargs *args = rqstp->rq_argp;
	struct kvec *head = rqstp->rq_arg.head;

	if (!svcxdr_decode_diropargs(xdr, &args->ffh, &args->fname, &args->flen))
		return false;
	if (xdr_stream_decode_u32(xdr, &args->tlen) < 0)
		return false;
	if (args->tlen == 0)
		return false;

	args->first.iov_len = head->iov_len - xdr_stream_pos(xdr);
	args->first.iov_base = xdr_inline_decode(xdr, args->tlen);
	if (!args->first.iov_base)
		return false;
	return svcxdr_decode_sattr(rqstp, xdr, &args->attrs);
}

bool
nfssvc_decode_readdirargs(struct svc_rqst *rqstp, struct xdr_stream *xdr)
{
	struct nfsd_readdirargs *args = rqstp->rq_argp;

	if (!svcxdr_decode_fhandle(xdr, &args->fh))
		return false;
	if (xdr_stream_decode_u32(xdr, &args->cookie) < 0)
		return false;
	if (xdr_stream_decode_u32(xdr, &args->count) < 0)
		return false;

	return true;
}

/*
 * XDR encode functions
 */

bool
nfssvc_encode_statres(struct svc_rqst *rqstp, struct xdr_stream *xdr)
{
	struct nfsd_stat *resp = rqstp->rq_resp;

	return svcxdr_encode_stat(xdr, resp->status);
}

bool
nfssvc_encode_attrstatres(struct svc_rqst *rqstp, struct xdr_stream *xdr)
{
	struct nfsd_attrstat *resp = rqstp->rq_resp;

	if (!svcxdr_encode_stat(xdr, resp->status))
		return false;
	switch (resp->status) {
	case nfs_ok:
		if (!svcxdr_encode_fattr(rqstp, xdr, &resp->fh, &resp->stat))
			return false;
		break;
	}

	return true;
}

bool
nfssvc_encode_diropres(struct svc_rqst *rqstp, struct xdr_stream *xdr)
{
	struct nfsd_diropres *resp = rqstp->rq_resp;

	if (!svcxdr_encode_stat(xdr, resp->status))
		return false;
	switch (resp->status) {
	case nfs_ok:
		if (!svcxdr_encode_fhandle(xdr, &resp->fh))
			return false;
		if (!svcxdr_encode_fattr(rqstp, xdr, &resp->fh, &resp->stat))
			return false;
		break;
	}

	return true;
}

bool
nfssvc_encode_readlinkres(struct svc_rqst *rqstp, struct xdr_stream *xdr)
{
	struct nfsd_readlinkres *resp = rqstp->rq_resp;
	struct kvec *head = rqstp->rq_res.head;

	if (!svcxdr_encode_stat(xdr, resp->status))
		return false;
	switch (resp->status) {
	case nfs_ok:
		if (xdr_stream_encode_u32(xdr, resp->len) < 0)
			return false;
		svcxdr_encode_opaque_pages(rqstp, xdr, &resp->page, 0,
					   resp->len);
		if (svc_encode_result_payload(rqstp, head->iov_len, resp->len) < 0)
			return false;
		break;
	}

	return true;
}

bool
nfssvc_encode_readres(struct svc_rqst *rqstp, struct xdr_stream *xdr)
{
	struct nfsd_readres *resp = rqstp->rq_resp;
	struct kvec *head = rqstp->rq_res.head;

	if (!svcxdr_encode_stat(xdr, resp->status))
		return false;
	switch (resp->status) {
	case nfs_ok:
		if (!svcxdr_encode_fattr(rqstp, xdr, &resp->fh, &resp->stat))
			return false;
		if (xdr_stream_encode_u32(xdr, resp->count) < 0)
			return false;
		svcxdr_encode_opaque_pages(rqstp, xdr, resp->pages,
					   rqstp->rq_res.page_base,
					   resp->count);
		if (svc_encode_result_payload(rqstp, head->iov_len, resp->count) < 0)
			return false;
		break;
	}

	return true;
}

bool
nfssvc_encode_readdirres(struct svc_rqst *rqstp, struct xdr_stream *xdr)
{
	struct nfsd_readdirres *resp = rqstp->rq_resp;
	struct xdr_buf *dirlist = &resp->dirlist;

	if (!svcxdr_encode_stat(xdr, resp->status))
		return false;
	switch (resp->status) {
	case nfs_ok:
		svcxdr_encode_opaque_pages(rqstp, xdr, dirlist->pages, 0,
					   dirlist->len);
		/* no more entries */
		if (xdr_stream_encode_item_absent(xdr) < 0)
			return false;
		if (xdr_stream_encode_bool(xdr, resp->common.err == nfserr_eof) < 0)
			return false;
		break;
	}

	return true;
}

bool
nfssvc_encode_statfsres(struct svc_rqst *rqstp, struct xdr_stream *xdr)
{
	struct nfsd_statfsres *resp = rqstp->rq_resp;
	struct kstatfs	*stat = &resp->stats;
	__be32 *p;

	if (!svcxdr_encode_stat(xdr, resp->status))
		return false;
	switch (resp->status) {
	case nfs_ok:
		p = xdr_reserve_space(xdr, XDR_UNIT * 5);
		if (!p)
			return false;
		*p++ = cpu_to_be32(NFS_MAXDATA);
		*p++ = cpu_to_be32(stat->f_bsize);
		*p++ = cpu_to_be32(stat->f_blocks);
		*p++ = cpu_to_be32(stat->f_bfree);
		*p = cpu_to_be32(stat->f_bavail);
		break;
	}

	return true;
}

/**
 * nfssvc_encode_nfscookie - Encode a directory offset cookie
 * @resp: readdir result context
 * @offset: offset cookie to encode
 *
 * The buffer space for the offset cookie has already been reserved
 * by svcxdr_encode_entry_common().
 */
void nfssvc_encode_nfscookie(struct nfsd_readdirres *resp, u32 offset)
{
	__be32 cookie = cpu_to_be32(offset);

	if (!resp->cookie_offset)
		return;

	write_bytes_to_xdr_buf(&resp->dirlist, resp->cookie_offset, &cookie,
			       sizeof(cookie));
	resp->cookie_offset = 0;
}

static bool
svcxdr_encode_entry_common(struct nfsd_readdirres *resp, const char *name,
			   int namlen, loff_t offset, u64 ino)
{
	struct xdr_buf *dirlist = &resp->dirlist;
	struct xdr_stream *xdr = &resp->xdr;

	if (xdr_stream_encode_item_present(xdr) < 0)
		return false;
	/* fileid */
	if (xdr_stream_encode_u32(xdr, (u32)ino) < 0)
		return false;
	/* name */
	if (xdr_stream_encode_opaque(xdr, name, min(namlen, NFS2_MAXNAMLEN)) < 0)
		return false;
	/* cookie */
	resp->cookie_offset = dirlist->len;
	if (xdr_stream_encode_u32(xdr, ~0U) < 0)
		return false;

	return true;
}

/**
 * nfssvc_encode_entry - encode one NFSv2 READDIR entry
 * @data: directory context
 * @name: name of the object to be encoded
 * @namlen: length of that name, in bytes
 * @offset: the offset of the previous entry
 * @ino: the fileid of this entry
 * @d_type: unused
 *
 * Return values:
 *   %0: Entry was successfully encoded.
 *   %-EINVAL: An encoding problem occured, secondary status code in resp->common.err
 *
 * On exit, the following fields are updated:
 *   - resp->xdr
 *   - resp->common.err
 *   - resp->cookie_offset
 */
int nfssvc_encode_entry(void *data, const char *name, int namlen,
			loff_t offset, u64 ino, unsigned int d_type)
{
	struct readdir_cd *ccd = data;
	struct nfsd_readdirres *resp = container_of(ccd,
						    struct nfsd_readdirres,
						    common);
	unsigned int starting_length = resp->dirlist.len;

	/* The offset cookie for the previous entry */
	nfssvc_encode_nfscookie(resp, offset);

	if (!svcxdr_encode_entry_common(resp, name, namlen, offset, ino))
		goto out_toosmall;

	xdr_commit_encode(&resp->xdr);
	resp->common.err = nfs_ok;
	return 0;

out_toosmall:
	resp->cookie_offset = 0;
	resp->common.err = nfserr_toosmall;
	resp->dirlist.len = starting_length;
	return -EINVAL;
}

/*
 * XDR release functions
 */
void nfssvc_release_attrstat(struct svc_rqst *rqstp)
{
	struct nfsd_attrstat *resp = rqstp->rq_resp;

	fh_put(&resp->fh);
}

void nfssvc_release_diropres(struct svc_rqst *rqstp)
{
	struct nfsd_diropres *resp = rqstp->rq_resp;

	fh_put(&resp->fh);
}

void nfssvc_release_readres(struct svc_rqst *rqstp)
{
	struct nfsd_readres *resp = rqstp->rq_resp;

	fh_put(&resp->fh);
}
Commit	Line	Data
	1	// SPDX-License-Identifier: GPL-2.0
	2	/*
	3	* XDR support for nfsd
	4	*
	5	* Copyright (C) 1995, 1996 Olaf Kirch <okir@monad.swb.de>
	6	*/
	7
	8	#include "vfs.h"
	9	#include "xdr.h"
	10	#include "auth.h"
	11
	12	/*
	13	* Mapping of S_IF* types to NFS file types
	14	*/
	15	static const u32 nfs_ftypes[] = {
	16	NFNON, NFCHR, NFCHR, NFBAD,
	17	NFDIR, NFBAD, NFBLK, NFBAD,
	18	NFREG, NFBAD, NFLNK, NFBAD,
	19	NFSOCK, NFBAD, NFLNK, NFBAD,
	20	};
	21
	22
	23	/*
	24	* Basic NFSv2 data types (RFC 1094 Section 2.3)
	25	*/
	26
	27	/**
	28	* svcxdr_encode_stat - Encode an NFSv2 status code
	29	* @xdr: XDR stream
	30	* @status: status value to encode
	31	*
	32	* Return values:
	33	* %false: Send buffer space was exhausted
	34	* %true: Success
	35	*/
	36	bool
	37	svcxdr_encode_stat(struct xdr_stream *xdr, __be32 status)
	38	{
	39	__be32 *p;
	40
	41	p = xdr_reserve_space(xdr, sizeof(status));
	42	if (!p)
	43	return false;
	44	*p = status;
	45
	46	return true;
	47	}
	48
	49	/**
	50	* svcxdr_decode_fhandle - Decode an NFSv2 file handle
	51	* @xdr: XDR stream positioned at an encoded NFSv2 FH
	52	* @fhp: OUT: filled-in server file handle
	53	*
	54	* Return values:
	55	* %false: The encoded file handle was not valid
	56	* %true: @fhp has been initialized
	57	*/
	58	bool
	59	svcxdr_decode_fhandle(struct xdr_stream xdr, struct svc_fh fhp)
	60	{
	61	__be32 *p;
	62
	63	p = xdr_inline_decode(xdr, NFS_FHSIZE);
	64	if (!p)
	65	return false;
	66	fh_init(fhp, NFS_FHSIZE);
	67	memcpy(&fhp->fh_handle.fh_raw, p, NFS_FHSIZE);
	68	fhp->fh_handle.fh_size = NFS_FHSIZE;
	69
	70	return true;
	71	}
	72
	73	static bool
	74	svcxdr_encode_fhandle(struct xdr_stream xdr, const struct svc_fh fhp)
	75	{
	76	__be32 *p;
	77
	78	p = xdr_reserve_space(xdr, NFS_FHSIZE);
	79	if (!p)
	80	return false;
	81	memcpy(p, &fhp->fh_handle.fh_raw, NFS_FHSIZE);
	82
	83	return true;
	84	}
	85
	86	static __be32 *
	87	encode_timeval(__be32 p, const struct timespec64 time)
	88	{
	89	*p++ = cpu_to_be32((u32)time->tv_sec);
	90	if (time->tv_nsec)
	91	*p++ = cpu_to_be32(time->tv_nsec / NSEC_PER_USEC);
	92	else
	93	*p++ = xdr_zero;
	94	return p;
	95	}
	96
	97	static bool
	98	svcxdr_decode_filename(struct xdr_stream xdr, char name, unsigned int len)
	99	{
	100	u32 size, i;
	101	__be32 *p;
	102	char *c;
	103
	104	if (xdr_stream_decode_u32(xdr, &size) < 0)
	105	return false;
	106	if (size == 0 \|\| size > NFS_MAXNAMLEN)
	107	return false;
	108	p = xdr_inline_decode(xdr, size);
	109	if (!p)
	110	return false;
	111
	112	*len = size;
	113	name = (char )p;
	114	for (i = 0, c = *name; i < size; i++, c++)
	115	if (c == '\0' \|\| c == '/')
	116	return false;
	117
	118	return true;
	119	}
	120
	121	static bool
	122	svcxdr_decode_diropargs(struct xdr_stream xdr, struct svc_fh fhp,
	123	char *name, unsigned int len)
	124	{
	125	return svcxdr_decode_fhandle(xdr, fhp) &&
	126	svcxdr_decode_filename(xdr, name, len);
	127	}
	128
	129	static bool
	130	svcxdr_decode_sattr(struct svc_rqst rqstp, struct xdr_stream xdr,
	131	struct iattr *iap)
	132	{
	133	u32 tmp1, tmp2;
	134	__be32 *p;
	135
	136	p = xdr_inline_decode(xdr, XDR_UNIT * 8);
	137	if (!p)
	138	return false;
	139
	140	iap->ia_valid = 0;
	141
	142	/*
	143	* Some Sun clients put 0xffff in the mode field when they
	144	* mean 0xffffffff.
	145	*/
	146	tmp1 = be32_to_cpup(p++);
	147	if (tmp1 != (u32)-1 && tmp1 != 0xffff) {
	148	iap->ia_valid \|= ATTR_MODE;
	149	iap->ia_mode = tmp1;
	150	}
	151
	152	tmp1 = be32_to_cpup(p++);
	153	if (tmp1 != (u32)-1) {
	154	iap->ia_uid = make_kuid(nfsd_user_namespace(rqstp), tmp1);
	155	if (uid_valid(iap->ia_uid))
	156	iap->ia_valid \|= ATTR_UID;
	157	}
	158
	159	tmp1 = be32_to_cpup(p++);
	160	if (tmp1 != (u32)-1) {
	161	iap->ia_gid = make_kgid(nfsd_user_namespace(rqstp), tmp1);
	162	if (gid_valid(iap->ia_gid))
	163	iap->ia_valid \|= ATTR_GID;
	164	}
	165
	166	tmp1 = be32_to_cpup(p++);
	167	if (tmp1 != (u32)-1) {
	168	iap->ia_valid \|= ATTR_SIZE;
	169	iap->ia_size = tmp1;
	170	}
	171
	172	tmp1 = be32_to_cpup(p++);
	173	tmp2 = be32_to_cpup(p++);
	174	if (tmp1 != (u32)-1 && tmp2 != (u32)-1) {
	175	iap->ia_valid \|= ATTR_ATIME \| ATTR_ATIME_SET;
	176	iap->ia_atime.tv_sec = tmp1;
	177	iap->ia_atime.tv_nsec = tmp2 * NSEC_PER_USEC;
	178	}
	179
	180	tmp1 = be32_to_cpup(p++);
	181	tmp2 = be32_to_cpup(p++);
	182	if (tmp1 != (u32)-1 && tmp2 != (u32)-1) {
	183	iap->ia_valid \|= ATTR_MTIME \| ATTR_MTIME_SET;
	184	iap->ia_mtime.tv_sec = tmp1;
	185	iap->ia_mtime.tv_nsec = tmp2 * NSEC_PER_USEC;
	186	/*
	187	* Passing the invalid value useconds=1000000 for mtime
	188	* is a Sun convention for "set both mtime and atime to
	189	* current server time". It's needed to make permissions
	190	* checks for the "touch" program across v2 mounts to
	191	* Solaris and Irix boxes work correctly. See description of
	192	* sattr in section 6.1 of "NFS Illustrated" by
	193	* Brent Callaghan, Addison-Wesley, ISBN 0-201-32750-5
	194	*/
	195	if (tmp2 == 1000000)
	196	iap->ia_valid &= ~(ATTR_ATIME_SET\|ATTR_MTIME_SET);
	197	}
	198
	199	return true;
	200	}
	201
	202	/**
	203	* svcxdr_encode_fattr - Encode NFSv2 file attributes
	204	* @rqstp: Context of a completed RPC transaction
	205	* @xdr: XDR stream
	206	* @fhp: File handle to encode
	207	* @stat: Attributes to encode
	208	*
	209	* Return values:
	210	* %false: Send buffer space was exhausted
	211	* %true: Success
	212	*/
	213	bool
	214	svcxdr_encode_fattr(struct svc_rqst rqstp, struct xdr_stream xdr,
	215	const struct svc_fh fhp, const struct kstat stat)
	216	{
	217	struct user_namespace *userns = nfsd_user_namespace(rqstp);
	218	struct dentry *dentry = fhp->fh_dentry;
	219	int type = stat->mode & S_IFMT;
	220	struct timespec64 time;
	221	__be32 *p;
	222	u32 fsid;
	223
	224	p = xdr_reserve_space(xdr, XDR_UNIT * 17);
	225	if (!p)
	226	return false;
	227
	228	*p++ = cpu_to_be32(nfs_ftypes[type >> 12]);
	229	*p++ = cpu_to_be32((u32)stat->mode);
	230	*p++ = cpu_to_be32((u32)stat->nlink);
	231	*p++ = cpu_to_be32((u32)from_kuid_munged(userns, stat->uid));
	232	*p++ = cpu_to_be32((u32)from_kgid_munged(userns, stat->gid));
	233
	234	if (S_ISLNK(type) && stat->size > NFS_MAXPATHLEN)
	235	*p++ = cpu_to_be32(NFS_MAXPATHLEN);
	236	else
	237	*p++ = cpu_to_be32((u32) stat->size);
	238	*p++ = cpu_to_be32((u32) stat->blksize);
	239	if (S_ISCHR(type) \|\| S_ISBLK(type))
	240	*p++ = cpu_to_be32(new_encode_dev(stat->rdev));
	241	else
	242	*p++ = cpu_to_be32(0xffffffff);
	243	*p++ = cpu_to_be32((u32)stat->blocks);
	244
	245	switch (fsid_source(fhp)) {
	246	case FSIDSOURCE_FSID:
	247	fsid = (u32)fhp->fh_export->ex_fsid;
	248	break;
	249	case FSIDSOURCE_UUID:
	250	fsid = ((u32 *)fhp->fh_export->ex_uuid)[0];
	251	fsid ^= ((u32 *)fhp->fh_export->ex_uuid)[1];
	252	fsid ^= ((u32 *)fhp->fh_export->ex_uuid)[2];
	253	fsid ^= ((u32 *)fhp->fh_export->ex_uuid)[3];
	254	break;
	255	default:
	256	fsid = new_encode_dev(stat->dev);
	257	break;
	258	}
	259	*p++ = cpu_to_be32(fsid);
	260
	261	*p++ = cpu_to_be32((u32)stat->ino);
	262	p = encode_timeval(p, &stat->atime);
	263	time = stat->mtime;
	264	lease_get_mtime(d_inode(dentry), &time);
	265	p = encode_timeval(p, &time);
	266	encode_timeval(p, &stat->ctime);
	267
	268	return true;
	269	}
	270
	271	/*
	272	* XDR decode functions
	273	*/
	274
	275	bool
	276	nfssvc_decode_fhandleargs(struct svc_rqst rqstp, struct xdr_stream xdr)
	277	{
	278	struct nfsd_fhandle *args = rqstp->rq_argp;
	279
	280	return svcxdr_decode_fhandle(xdr, &args->fh);
	281	}
	282
	283	bool
	284	nfssvc_decode_sattrargs(struct svc_rqst rqstp, struct xdr_stream xdr)
	285	{
	286	struct nfsd_sattrargs *args = rqstp->rq_argp;
	287
	288	return svcxdr_decode_fhandle(xdr, &args->fh) &&
	289	svcxdr_decode_sattr(rqstp, xdr, &args->attrs);
	290	}
	291
	292	bool
	293	nfssvc_decode_diropargs(struct svc_rqst rqstp, struct xdr_stream xdr)
	294	{
	295	struct nfsd_diropargs *args = rqstp->rq_argp;
	296
	297	return svcxdr_decode_diropargs(xdr, &args->fh, &args->name, &args->len);
	298	}
	299
	300	bool
	301	nfssvc_decode_readargs(struct svc_rqst rqstp, struct xdr_stream xdr)
	302	{
	303	struct nfsd_readargs *args = rqstp->rq_argp;
	304	u32 totalcount;
	305
	306	if (!svcxdr_decode_fhandle(xdr, &args->fh))
	307	return false;
	308	if (xdr_stream_decode_u32(xdr, &args->offset) < 0)
	309	return false;
	310	if (xdr_stream_decode_u32(xdr, &args->count) < 0)
	311	return false;
	312	/* totalcount is ignored */
	313	if (xdr_stream_decode_u32(xdr, &totalcount) < 0)
	314	return false;
	315
	316	return true;
	317	}
	318
	319	bool
	320	nfssvc_decode_writeargs(struct svc_rqst rqstp, struct xdr_stream xdr)
	321	{
	322	struct nfsd_writeargs *args = rqstp->rq_argp;
	323	u32 beginoffset, totalcount;
	324
	325	if (!svcxdr_decode_fhandle(xdr, &args->fh))
	326	return false;
	327	/* beginoffset is ignored */
	328	if (xdr_stream_decode_u32(xdr, &beginoffset) < 0)
	329	return false;
	330	if (xdr_stream_decode_u32(xdr, &args->offset) < 0)
	331	return false;
	332	/* totalcount is ignored */
	333	if (xdr_stream_decode_u32(xdr, &totalcount) < 0)
	334	return false;
	335
	336	/* opaque data */
	337	if (xdr_stream_decode_u32(xdr, &args->len) < 0)
	338	return false;
	339	if (args->len > NFS_MAXDATA)
	340	return false;
	341
	342	return xdr_stream_subsegment(xdr, &args->payload, args->len);
	343	}
	344
	345	bool
	346	nfssvc_decode_createargs(struct svc_rqst rqstp, struct xdr_stream xdr)
	347	{
	348	struct nfsd_createargs *args = rqstp->rq_argp;
	349
	350	return svcxdr_decode_diropargs(xdr, &args->fh,
	351	&args->name, &args->len) &&
	352	svcxdr_decode_sattr(rqstp, xdr, &args->attrs);
	353	}
	354
	355	bool
	356	nfssvc_decode_renameargs(struct svc_rqst rqstp, struct xdr_stream xdr)
	357	{
	358	struct nfsd_renameargs *args = rqstp->rq_argp;
	359
	360	return svcxdr_decode_diropargs(xdr, &args->ffh,
	361	&args->fname, &args->flen) &&
	362	svcxdr_decode_diropargs(xdr, &args->tfh,
	363	&args->tname, &args->tlen);
	364	}
	365
	366	bool
	367	nfssvc_decode_linkargs(struct svc_rqst rqstp, struct xdr_stream xdr)
	368	{
	369	struct nfsd_linkargs *args = rqstp->rq_argp;
	370
	371	return svcxdr_decode_fhandle(xdr, &args->ffh) &&
	372	svcxdr_decode_diropargs(xdr, &args->tfh,
	373	&args->tname, &args->tlen);
	374	}
	375
	376	bool
	377	nfssvc_decode_symlinkargs(struct svc_rqst rqstp, struct xdr_stream xdr)
	378	{
	379	struct nfsd_symlinkargs *args = rqstp->rq_argp;
	380	struct kvec *head = rqstp->rq_arg.head;
	381
	382	if (!svcxdr_decode_diropargs(xdr, &args->ffh, &args->fname, &args->flen))
	383	return false;
	384	if (xdr_stream_decode_u32(xdr, &args->tlen) < 0)
	385	return false;
	386	if (args->tlen == 0)
	387	return false;
	388
	389	args->first.iov_len = head->iov_len - xdr_stream_pos(xdr);
	390	args->first.iov_base = xdr_inline_decode(xdr, args->tlen);
	391	if (!args->first.iov_base)
	392	return false;
	393	return svcxdr_decode_sattr(rqstp, xdr, &args->attrs);
	394	}
	395
	396	bool
	397	nfssvc_decode_readdirargs(struct svc_rqst rqstp, struct xdr_stream xdr)
	398	{
	399	struct nfsd_readdirargs *args = rqstp->rq_argp;
	400
	401	if (!svcxdr_decode_fhandle(xdr, &args->fh))
	402	return false;
	403	if (xdr_stream_decode_u32(xdr, &args->cookie) < 0)
	404	return false;
	405	if (xdr_stream_decode_u32(xdr, &args->count) < 0)
	406	return false;
	407
	408	return true;
	409	}
	410
	411	/*
	412	* XDR encode functions
	413	*/
	414
	415	bool
	416	nfssvc_encode_statres(struct svc_rqst rqstp, struct xdr_stream xdr)
	417	{
	418	struct nfsd_stat *resp = rqstp->rq_resp;
	419
	420	return svcxdr_encode_stat(xdr, resp->status);
	421	}
	422
	423	bool
	424	nfssvc_encode_attrstatres(struct svc_rqst rqstp, struct xdr_stream xdr)
	425	{
	426	struct nfsd_attrstat *resp = rqstp->rq_resp;
	427
	428	if (!svcxdr_encode_stat(xdr, resp->status))
	429	return false;
	430	switch (resp->status) {
	431	case nfs_ok:
	432	if (!svcxdr_encode_fattr(rqstp, xdr, &resp->fh, &resp->stat))
	433	return false;
	434	break;
	435	}
	436
	437	return true;
	438	}
	439
	440	bool
	441	nfssvc_encode_diropres(struct svc_rqst rqstp, struct xdr_stream xdr)
	442	{
	443	struct nfsd_diropres *resp = rqstp->rq_resp;
	444
	445	if (!svcxdr_encode_stat(xdr, resp->status))
	446	return false;
	447	switch (resp->status) {
	448	case nfs_ok:
	449	if (!svcxdr_encode_fhandle(xdr, &resp->fh))
	450	return false;
	451	if (!svcxdr_encode_fattr(rqstp, xdr, &resp->fh, &resp->stat))
	452	return false;
	453	break;
	454	}
	455
	456	return true;
	457	}
	458
	459	bool
	460	nfssvc_encode_readlinkres(struct svc_rqst rqstp, struct xdr_stream xdr)
	461	{
	462	struct nfsd_readlinkres *resp = rqstp->rq_resp;
	463	struct kvec *head = rqstp->rq_res.head;
	464
	465	if (!svcxdr_encode_stat(xdr, resp->status))
	466	return false;
	467	switch (resp->status) {
	468	case nfs_ok:
	469	if (xdr_stream_encode_u32(xdr, resp->len) < 0)
	470	return false;
	471	svcxdr_encode_opaque_pages(rqstp, xdr, &resp->page, 0,
	472	resp->len);
	473	if (svc_encode_result_payload(rqstp, head->iov_len, resp->len) < 0)
	474	return false;
	475	break;
	476	}
	477
	478	return true;
	479	}
	480
	481	bool
	482	nfssvc_encode_readres(struct svc_rqst rqstp, struct xdr_stream xdr)
	483	{
	484	struct nfsd_readres *resp = rqstp->rq_resp;
	485	struct kvec *head = rqstp->rq_res.head;
	486
	487	if (!svcxdr_encode_stat(xdr, resp->status))
	488	return false;
	489	switch (resp->status) {
	490	case nfs_ok:
	491	if (!svcxdr_encode_fattr(rqstp, xdr, &resp->fh, &resp->stat))
	492	return false;
	493	if (xdr_stream_encode_u32(xdr, resp->count) < 0)
	494	return false;
	495	svcxdr_encode_opaque_pages(rqstp, xdr, resp->pages,
	496	rqstp->rq_res.page_base,
	497	resp->count);
	498	if (svc_encode_result_payload(rqstp, head->iov_len, resp->count) < 0)
	499	return false;
	500	break;
	501	}
	502
	503	return true;
	504	}
	505
	506	bool
	507	nfssvc_encode_readdirres(struct svc_rqst rqstp, struct xdr_stream xdr)
	508	{
	509	struct nfsd_readdirres *resp = rqstp->rq_resp;
	510	struct xdr_buf *dirlist = &resp->dirlist;
	511
	512	if (!svcxdr_encode_stat(xdr, resp->status))
	513	return false;
	514	switch (resp->status) {
	515	case nfs_ok:
	516	svcxdr_encode_opaque_pages(rqstp, xdr, dirlist->pages, 0,
	517	dirlist->len);
	518	/* no more entries */
	519	if (xdr_stream_encode_item_absent(xdr) < 0)
	520	return false;
	521	if (xdr_stream_encode_bool(xdr, resp->common.err == nfserr_eof) < 0)
	522	return false;
	523	break;
	524	}
	525
	526	return true;
	527	}
	528
	529	bool
	530	nfssvc_encode_statfsres(struct svc_rqst rqstp, struct xdr_stream xdr)
	531	{
	532	struct nfsd_statfsres *resp = rqstp->rq_resp;
	533	struct kstatfs *stat = &resp->stats;
	534	__be32 *p;
	535
	536	if (!svcxdr_encode_stat(xdr, resp->status))
	537	return false;
	538	switch (resp->status) {
	539	case nfs_ok:
	540	p = xdr_reserve_space(xdr, XDR_UNIT * 5);
	541	if (!p)
	542	return false;
	543	*p++ = cpu_to_be32(NFS_MAXDATA);
	544	*p++ = cpu_to_be32(stat->f_bsize);
	545	*p++ = cpu_to_be32(stat->f_blocks);
	546	*p++ = cpu_to_be32(stat->f_bfree);
	547	*p = cpu_to_be32(stat->f_bavail);
	548	break;
	549	}
	550
	551	return true;
	552	}
	553
	554	/**
	555	* nfssvc_encode_nfscookie - Encode a directory offset cookie
	556	* @resp: readdir result context
	557	* @offset: offset cookie to encode
	558	*
	559	* The buffer space for the offset cookie has already been reserved
	560	* by svcxdr_encode_entry_common().
	561	*/
	562	void nfssvc_encode_nfscookie(struct nfsd_readdirres *resp, u32 offset)
	563	{
	564	__be32 cookie = cpu_to_be32(offset);
	565
	566	if (!resp->cookie_offset)
	567	return;
	568
	569	write_bytes_to_xdr_buf(&resp->dirlist, resp->cookie_offset, &cookie,
	570	sizeof(cookie));
	571	resp->cookie_offset = 0;
	572	}
	573
	574	static bool
	575	svcxdr_encode_entry_common(struct nfsd_readdirres resp, const char name,
	576	int namlen, loff_t offset, u64 ino)
	577	{
	578	struct xdr_buf *dirlist = &resp->dirlist;
	579	struct xdr_stream *xdr = &resp->xdr;
	580
	581	if (xdr_stream_encode_item_present(xdr) < 0)
	582	return false;
	583	/* fileid */
	584	if (xdr_stream_encode_u32(xdr, (u32)ino) < 0)
	585	return false;
	586	/* name */
	587	if (xdr_stream_encode_opaque(xdr, name, min(namlen, NFS2_MAXNAMLEN)) < 0)
	588	return false;
	589	/* cookie */
	590	resp->cookie_offset = dirlist->len;
	591	if (xdr_stream_encode_u32(xdr, ~0U) < 0)
	592	return false;
	593
	594	return true;
	595	}
	596
	597	/**
	598	* nfssvc_encode_entry - encode one NFSv2 READDIR entry
	599	* @data: directory context
	600	* @name: name of the object to be encoded
	601	* @namlen: length of that name, in bytes
	602	* @offset: the offset of the previous entry
	603	* @ino: the fileid of this entry
	604	* @d_type: unused
	605	*
	606	* Return values:
	607	* %0: Entry was successfully encoded.
	608	* %-EINVAL: An encoding problem occured, secondary status code in resp->common.err
	609	*
	610	* On exit, the following fields are updated:
	611	* - resp->xdr
	612	* - resp->common.err
	613	* - resp->cookie_offset
	614	*/
	615	int nfssvc_encode_entry(void data, const char name, int namlen,
	616	loff_t offset, u64 ino, unsigned int d_type)
	617	{
	618	struct readdir_cd *ccd = data;
	619	struct nfsd_readdirres *resp = container_of(ccd,
	620	struct nfsd_readdirres,
	621	common);
	622	unsigned int starting_length = resp->dirlist.len;
	623
	624	/* The offset cookie for the previous entry */
	625	nfssvc_encode_nfscookie(resp, offset);
	626
	627	if (!svcxdr_encode_entry_common(resp, name, namlen, offset, ino))
	628	goto out_toosmall;
	629
	630	xdr_commit_encode(&resp->xdr);
	631	resp->common.err = nfs_ok;
	632	return 0;
	633
	634	out_toosmall:
	635	resp->cookie_offset = 0;
	636	resp->common.err = nfserr_toosmall;
	637	resp->dirlist.len = starting_length;
	638	return -EINVAL;
	639	}
	640
	641	/*
	642	* XDR release functions
	643	*/
	644	void nfssvc_release_attrstat(struct svc_rqst *rqstp)
	645	{
	646	struct nfsd_attrstat *resp = rqstp->rq_resp;
	647
	648	fh_put(&resp->fh);
	649	}
	650
	651	void nfssvc_release_diropres(struct svc_rqst *rqstp)
	652	{
	653	struct nfsd_diropres *resp = rqstp->rq_resp;
	654
	655	fh_put(&resp->fh);
	656	}
	657
	658	void nfssvc_release_readres(struct svc_rqst *rqstp)
	659	{
	660	struct nfsd_readres *resp = rqstp->rq_resp;
	661
	662	fh_put(&resp->fh);
	663	}