// 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 > NFSSVC_MAXBLKSIZE_V2)
return false;
if (!xdr_stream_subsegment(xdr, &args->payload, args->len))
return false;
return true;
}
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;
xdr_write_pages(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;
xdr_write_pages(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:
xdr_write_pages(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(NFSSVC_MAXBLKSIZE_V2);
*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);
}
