// 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"
#define NFSDDBG_FACILITY NFSDDBG_XDR
/*
* Mapping of S_IF* types to NFS file types
*/
static 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_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_base, p, NFS_FHSIZE);
fhp->fh_handle.fh_size = NFS_FHSIZE;
return true;
}
static __be32 *
encode_fh(__be32 *p, struct svc_fh *fhp)
{
memcpy(p, &fhp->fh_handle.fh_base, NFS_FHSIZE);
return p + (NFS_FHSIZE>> 2);
}
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;
}
static __be32 *
encode_fattr(struct svc_rqst *rqstp, __be32 *p, struct svc_fh *fhp,
struct kstat *stat)
{
struct user_namespace *userns = nfsd_user_namespace(rqstp);
struct dentry *dentry = fhp->fh_dentry;
int type;
struct timespec64 time;
u32 f;
type = (stat->mode & S_IFMT);
*p++ = htonl(nfs_ftypes[type >> 12]);
*p++ = htonl((u32) stat->mode);
*p++ = htonl((u32) stat->nlink);
*p++ = htonl((u32) from_kuid_munged(userns, stat->uid));
*p++ = htonl((u32) from_kgid_munged(userns, stat->gid));
if (S_ISLNK(type) && stat->size > NFS_MAXPATHLEN) {
*p++ = htonl(NFS_MAXPATHLEN);
} else {
*p++ = htonl((u32) stat->size);
}
*p++ = htonl((u32) stat->blksize);
if (S_ISCHR(type) || S_ISBLK(type))
*p++ = htonl(new_encode_dev(stat->rdev));
else
*p++ = htonl(0xffffffff);
*p++ = htonl((u32) stat->blocks);
switch (fsid_source(fhp)) {
default:
case FSIDSOURCE_DEV:
*p++ = htonl(new_encode_dev(stat->dev));
break;
case FSIDSOURCE_FSID:
*p++ = htonl((u32) fhp->fh_export->ex_fsid);
break;
case FSIDSOURCE_UUID:
f = ((u32*)fhp->fh_export->ex_uuid)[0];
f ^= ((u32*)fhp->fh_export->ex_uuid)[1];
f ^= ((u32*)fhp->fh_export->ex_uuid)[2];
f ^= ((u32*)fhp->fh_export->ex_uuid)[3];
*p++ = htonl(f);
break;
}
*p++ = htonl((u32) stat->ino);
*p++ = htonl((u32) stat->atime.tv_sec);
*p++ = htonl(stat->atime.tv_nsec ? stat->atime.tv_nsec / 1000 : 0);
time = stat->mtime;
lease_get_mtime(d_inode(dentry), &time);
*p++ = htonl((u32) time.tv_sec);
*p++ = htonl(time.tv_nsec ? time.tv_nsec / 1000 : 0);
*p++ = htonl((u32) stat->ctime.tv_sec);
*p++ = htonl(stat->ctime.tv_nsec ? stat->ctime.tv_nsec / 1000 : 0);
return p;
}
/* Helper function for NFSv2 ACL code */
__be32 *nfs2svc_encode_fattr(struct svc_rqst *rqstp, __be32 *p, struct svc_fh *fhp, struct kstat *stat)
{
return encode_fattr(rqstp, p, fhp, stat);
}
/*
* XDR decode functions
*/
int
nfssvc_decode_fhandleargs(struct svc_rqst *rqstp, __be32 *p)
{
struct xdr_stream *xdr = &rqstp->rq_arg_stream;
struct nfsd_fhandle *args = rqstp->rq_argp;
return svcxdr_decode_fhandle(xdr, &args->fh);
}
int
nfssvc_decode_sattrargs(struct svc_rqst *rqstp, __be32 *p)
{
struct xdr_stream *xdr = &rqstp->rq_arg_stream;
struct nfsd_sattrargs *args = rqstp->rq_argp;
return svcxdr_decode_fhandle(xdr, &args->fh) &&
svcxdr_decode_sattr(rqstp, xdr, &args->attrs);
}
int
nfssvc_decode_diropargs(struct svc_rqst *rqstp, __be32 *p)
{
struct xdr_stream *xdr = &rqstp->rq_arg_stream;
struct nfsd_diropargs *args = rqstp->rq_argp;
return svcxdr_decode_diropargs(xdr, &args->fh, &args->name, &args->len);
}
int
nfssvc_decode_readargs(struct svc_rqst *rqstp, __be32 *p)
{
struct xdr_stream *xdr = &rqstp->rq_arg_stream;
struct nfsd_readargs *args = rqstp->rq_argp;
u32 totalcount;
if (!svcxdr_decode_fhandle(xdr, &args->fh))
return 0;
if (xdr_stream_decode_u32(xdr, &args->offset) < 0)
return 0;
if (xdr_stream_decode_u32(xdr, &args->count) < 0)
return 0;
/* totalcount is ignored */
if (xdr_stream_decode_u32(xdr, &totalcount) < 0)
return 0;
return 1;
}
int
nfssvc_decode_writeargs(struct svc_rqst *rqstp, __be32 *p)
{
struct xdr_stream *xdr = &rqstp->rq_arg_stream;
struct nfsd_writeargs *args = rqstp->rq_argp;
struct kvec *head = rqstp->rq_arg.head;
struct kvec *tail = rqstp->rq_arg.tail;
u32 beginoffset, totalcount;
size_t remaining;
if (!svcxdr_decode_fhandle(xdr, &args->fh))
return 0;
/* beginoffset is ignored */
if (xdr_stream_decode_u32(xdr, &beginoffset) < 0)
return 0;
if (xdr_stream_decode_u32(xdr, &args->offset) < 0)
return 0;
/* totalcount is ignored */
if (xdr_stream_decode_u32(xdr, &totalcount) < 0)
return 0;
/* opaque data */
if (xdr_stream_decode_u32(xdr, &args->len) < 0)
return 0;
if (args->len > NFSSVC_MAXBLKSIZE_V2)
return 0;
remaining = head->iov_len + rqstp->rq_arg.page_len + tail->iov_len;
remaining -= xdr_stream_pos(xdr);
if (remaining < xdr_align_size(args->len))
return 0;
args->first.iov_base = xdr->p;
args->first.iov_len = head->iov_len - xdr_stream_pos(xdr);
return 1;
}
int
nfssvc_decode_createargs(struct svc_rqst *rqstp, __be32 *p)
{
struct xdr_stream *xdr = &rqstp->rq_arg_stream;
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);
}
int
nfssvc_decode_renameargs(struct svc_rqst *rqstp, __be32 *p)
{
struct xdr_stream *xdr = &rqstp->rq_arg_stream;
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);
}
int
nfssvc_decode_linkargs(struct svc_rqst *rqstp, __be32 *p)
{
struct xdr_stream *xdr = &rqstp->rq_arg_stream;
struct nfsd_linkargs *args = rqstp->rq_argp;
return svcxdr_decode_fhandle(xdr, &args->ffh) &&
svcxdr_decode_diropargs(xdr, &args->tfh,
&args->tname, &args->tlen);
}
int
nfssvc_decode_symlinkargs(struct svc_rqst *rqstp, __be32 *p)
{
struct xdr_stream *xdr = &rqstp->rq_arg_stream;
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 0;
if (xdr_stream_decode_u32(xdr, &args->tlen) < 0)
return 0;
if (args->tlen == 0)
return 0;
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 0;
return svcxdr_decode_sattr(rqstp, xdr, &args->attrs);
}
int
nfssvc_decode_readdirargs(struct svc_rqst *rqstp, __be32 *p)
{
struct xdr_stream *xdr = &rqstp->rq_arg_stream;
struct nfsd_readdirargs *args = rqstp->rq_argp;
if (!svcxdr_decode_fhandle(xdr, &args->fh))
return 0;
if (xdr_stream_decode_u32(xdr, &args->cookie) < 0)
return 0;
if (xdr_stream_decode_u32(xdr, &args->count) < 0)
return 0;
return 1;
}
/*
* XDR encode functions
*/
int
nfssvc_encode_stat(struct svc_rqst *rqstp, __be32 *p)
{
struct nfsd_stat *resp = rqstp->rq_resp;
*p++ = resp->status;
return xdr_ressize_check(rqstp, p);
}
int
nfssvc_encode_attrstat(struct svc_rqst *rqstp, __be32 *p)
{
struct nfsd_attrstat *resp = rqstp->rq_resp;
*p++ = resp->status;
if (resp->status != nfs_ok)
goto out;
p = encode_fattr(rqstp, p, &resp->fh, &resp->stat);
out:
return xdr_ressize_check(rqstp, p);
}
int
nfssvc_encode_diropres(struct svc_rqst *rqstp, __be32 *p)
{
struct nfsd_diropres *resp = rqstp->rq_resp;
*p++ = resp->status;
if (resp->status != nfs_ok)
goto out;
p = encode_fh(p, &resp->fh);
p = encode_fattr(rqstp, p, &resp->fh, &resp->stat);
out:
return xdr_ressize_check(rqstp, p);
}
int
nfssvc_encode_readlinkres(struct svc_rqst *rqstp, __be32 *p)
{
struct nfsd_readlinkres *resp = rqstp->rq_resp;
struct kvec *head = rqstp->rq_res.head;
*p++ = resp->status;
if (resp->status != nfs_ok)
return xdr_ressize_check(rqstp, p);
*p++ = htonl(resp->len);
xdr_ressize_check(rqstp, p);
rqstp->rq_res.page_len = resp->len;
if (resp->len & 3) {
/* need to pad the tail */
rqstp->rq_res.tail[0].iov_base = p;
*p = 0;
rqstp->rq_res.tail[0].iov_len = 4 - (resp->len&3);
}
if (svc_encode_result_payload(rqstp, head->iov_len, resp->len))
return 0;
return 1;
}
int
nfssvc_encode_readres(struct svc_rqst *rqstp, __be32 *p)
{
struct nfsd_readres *resp = rqstp->rq_resp;
struct kvec *head = rqstp->rq_res.head;
*p++ = resp->status;
if (resp->status != nfs_ok)
return xdr_ressize_check(rqstp, p);
p = encode_fattr(rqstp, p, &resp->fh, &resp->stat);
*p++ = htonl(resp->count);
xdr_ressize_check(rqstp, p);
/* now update rqstp->rq_res to reflect data as well */
rqstp->rq_res.page_len = resp->count;
if (resp->count & 3) {
/* need to pad the tail */
rqstp->rq_res.tail[0].iov_base = p;
*p = 0;
rqstp->rq_res.tail[0].iov_len = 4 - (resp->count&3);
}
if (svc_encode_result_payload(rqstp, head->iov_len, resp->count))
return 0;
return 1;
}
int
nfssvc_encode_readdirres(struct svc_rqst *rqstp, __be32 *p)
{
struct nfsd_readdirres *resp = rqstp->rq_resp;
*p++ = resp->status;
if (resp->status != nfs_ok)
return xdr_ressize_check(rqstp, p);
xdr_ressize_check(rqstp, p);
p = resp->buffer;
*p++ = 0; /* no more entries */
*p++ = htonl((resp->common.err == nfserr_eof));
rqstp->rq_res.page_len = (((unsigned long)p-1) & ~PAGE_MASK)+1;
return 1;
}
int
nfssvc_encode_statfsres(struct svc_rqst *rqstp, __be32 *p)
{
struct nfsd_statfsres *resp = rqstp->rq_resp;
struct kstatfs *stat = &resp->stats;
*p++ = resp->status;
if (resp->status != nfs_ok)
return xdr_ressize_check(rqstp, p);
*p++ = htonl(NFSSVC_MAXBLKSIZE_V2); /* max transfer size */
*p++ = htonl(stat->f_bsize);
*p++ = htonl(stat->f_blocks);
*p++ = htonl(stat->f_bfree);
*p++ = htonl(stat->f_bavail);
return xdr_ressize_check(rqstp, p);
}
int
nfssvc_encode_entry(void *ccdv, const char *name,
int namlen, loff_t offset, u64 ino, unsigned int d_type)
{
struct readdir_cd *ccd = ccdv;
struct nfsd_readdirres *cd = container_of(ccd, struct nfsd_readdirres, common);
__be32 *p = cd->buffer;
int buflen, slen;
/*
dprintk("nfsd: entry(%.*s off %ld ino %ld)\n",
namlen, name, offset, ino);
*/
if (offset > ~((u32) 0)) {
cd->common.err = nfserr_fbig;
return -EINVAL;
}
if (cd->offset)
*cd->offset = htonl(offset);
/* truncate filename */
namlen = min(namlen, NFS2_MAXNAMLEN);
slen = XDR_QUADLEN(namlen);
if ((buflen = cd->buflen - slen - 4) < 0) {
cd->common.err = nfserr_toosmall;
return -EINVAL;
}
if (ino > ~((u32) 0)) {
cd->common.err = nfserr_fbig;
return -EINVAL;
}
*p++ = xdr_one; /* mark entry present */
*p++ = htonl((u32) ino); /* file id */
p = xdr_encode_array(p, name, namlen);/* name length & name */
cd->offset = p; /* remember pointer */
*p++ = htonl(~0U); /* offset of next entry */
cd->buflen = buflen;
cd->buffer = p;
cd->common.err = nfs_ok;
return 0;
}
/*
* 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);
}