linux-next/fs/lockd/svcxdr.h
Chuck Lever 89c485c7a3 NLM: Fix svcxdr_encode_owner()
Dai Ngo reports that, since the XDR overhaul, the NLM server crashes
when the TEST procedure wants to return NLM_DENIED. There is a bug
in svcxdr_encode_owner() that none of our standard test cases found.

Replace the open-coded function with a call to an appropriate
pre-fabricated XDR helper.

Reported-by: Dai Ngo <Dai.Ngo@oracle.com>
Fixes: a6a63ca565 ("lockd: Common NLM XDR helpers")
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2021-09-17 10:35:10 -04:00

143 lines
2.8 KiB
C

/* SPDX-License-Identifier: GPL-2.0 */
/*
* Encode/decode NLM basic data types
*
* Basic NLMv3 XDR data types are not defined in an IETF standards
* document. X/Open has a description of these data types that
* is useful. See Chapter 10 of "Protocols for Interworking:
* XNFS, Version 3W".
*
* Basic NLMv4 XDR data types are defined in Appendix II.1.4 of
* RFC 1813: "NFS Version 3 Protocol Specification".
*
* Author: Chuck Lever <chuck.lever@oracle.com>
*
* Copyright (c) 2020, Oracle and/or its affiliates.
*/
#ifndef _LOCKD_SVCXDR_H_
#define _LOCKD_SVCXDR_H_
static inline bool
svcxdr_decode_stats(struct xdr_stream *xdr, __be32 *status)
{
__be32 *p;
p = xdr_inline_decode(xdr, XDR_UNIT);
if (!p)
return false;
*status = *p;
return true;
}
static inline bool
svcxdr_encode_stats(struct xdr_stream *xdr, __be32 status)
{
__be32 *p;
p = xdr_reserve_space(xdr, XDR_UNIT);
if (!p)
return false;
*p = status;
return true;
}
static inline bool
svcxdr_decode_string(struct xdr_stream *xdr, char **data, unsigned int *data_len)
{
__be32 *p;
u32 len;
if (xdr_stream_decode_u32(xdr, &len) < 0)
return false;
if (len > NLM_MAXSTRLEN)
return false;
p = xdr_inline_decode(xdr, len);
if (!p)
return false;
*data_len = len;
*data = (char *)p;
return true;
}
/*
* NLM cookies are defined by specification to be a variable-length
* XDR opaque no longer than 1024 bytes. However, this implementation
* limits their length to 32 bytes, and treats zero-length cookies
* specially.
*/
static inline bool
svcxdr_decode_cookie(struct xdr_stream *xdr, struct nlm_cookie *cookie)
{
__be32 *p;
u32 len;
if (xdr_stream_decode_u32(xdr, &len) < 0)
return false;
if (len > NLM_MAXCOOKIELEN)
return false;
if (!len)
goto out_hpux;
p = xdr_inline_decode(xdr, len);
if (!p)
return false;
cookie->len = len;
memcpy(cookie->data, p, len);
return true;
/* apparently HPUX can return empty cookies */
out_hpux:
cookie->len = 4;
memset(cookie->data, 0, 4);
return true;
}
static inline bool
svcxdr_encode_cookie(struct xdr_stream *xdr, const struct nlm_cookie *cookie)
{
__be32 *p;
if (xdr_stream_encode_u32(xdr, cookie->len) < 0)
return false;
p = xdr_reserve_space(xdr, cookie->len);
if (!p)
return false;
memcpy(p, cookie->data, cookie->len);
return true;
}
static inline bool
svcxdr_decode_owner(struct xdr_stream *xdr, struct xdr_netobj *obj)
{
__be32 *p;
u32 len;
if (xdr_stream_decode_u32(xdr, &len) < 0)
return false;
if (len > XDR_MAX_NETOBJ)
return false;
p = xdr_inline_decode(xdr, len);
if (!p)
return false;
obj->len = len;
obj->data = (u8 *)p;
return true;
}
static inline bool
svcxdr_encode_owner(struct xdr_stream *xdr, const struct xdr_netobj *obj)
{
if (obj->len > XDR_MAX_NETOBJ)
return false;
return xdr_stream_encode_opaque(xdr, obj->data, obj->len) > 0;
}
#endif /* _LOCKD_SVCXDR_H_ */