1/* SPDX-License-Identifier: GPL-2.0 */
  2/*
  3 * Encode/decode NLM basic data types
  4 *
  5 * Basic NLMv3 XDR data types are not defined in an IETF standards
  6 * document.  X/Open has a description of these data types that
  7 * is useful.  See Chapter 10 of "Protocols for Interworking:
  8 * XNFS, Version 3W".
  9 *
 10 * Basic NLMv4 XDR data types are defined in Appendix II.1.4 of
 11 * RFC 1813: "NFS Version 3 Protocol Specification".
 12 *
 13 * Author: Chuck Lever <chuck.lever@oracle.com>
 14 *
 15 * Copyright (c) 2020, Oracle and/or its affiliates.
 16 */
 17
 18#ifndef _LOCKD_SVCXDR_H_
 19#define _LOCKD_SVCXDR_H_
 20
 21static inline bool
 22svcxdr_decode_stats(struct xdr_stream *xdr, __be32 *status)
 23{
 24	__be32 *p;
 25
 26	p = xdr_inline_decode(xdr, XDR_UNIT);
 27	if (!p)
 28		return false;
 29	*status = *p;
 30
 31	return true;
 32}
 33
 34static inline bool
 35svcxdr_encode_stats(struct xdr_stream *xdr, __be32 status)
 36{
 37	__be32 *p;
 38
 39	p = xdr_reserve_space(xdr, XDR_UNIT);
 40	if (!p)
 41		return false;
 42	*p = status;
 43
 44	return true;
 45}
 46
 47static inline bool
 48svcxdr_decode_string(struct xdr_stream *xdr, char **data, unsigned int *data_len)
 49{
 50	__be32 *p;
 51	u32 len;
 52
 53	if (xdr_stream_decode_u32(xdr, &len) < 0)
 54		return false;
 55	if (len > NLM_MAXSTRLEN)
 56		return false;
 57	p = xdr_inline_decode(xdr, len);
 58	if (!p)
 59		return false;
 60	*data_len = len;
 61	*data = (char *)p;
 62
 63	return true;
 64}
 65
 66/*
 67 * NLM cookies are defined by specification to be a variable-length
 68 * XDR opaque no longer than 1024 bytes. However, this implementation
 69 * limits their length to 32 bytes, and treats zero-length cookies
 70 * specially.
 71 */
 72static inline bool
 73svcxdr_decode_cookie(struct xdr_stream *xdr, struct nlm_cookie *cookie)
 74{
 75	__be32 *p;
 76	u32 len;
 77
 78	if (xdr_stream_decode_u32(xdr, &len) < 0)
 79		return false;
 80	if (len > NLM_MAXCOOKIELEN)
 81		return false;
 82	if (!len)
 83		goto out_hpux;
 84
 85	p = xdr_inline_decode(xdr, len);
 86	if (!p)
 87		return false;
 88	cookie->len = len;
 89	memcpy(cookie->data, p, len);
 90
 91	return true;
 92
 93	/* apparently HPUX can return empty cookies */
 94out_hpux:
 95	cookie->len = 4;
 96	memset(cookie->data, 0, 4);
 97	return true;
 98}
 99
100static inline bool
101svcxdr_encode_cookie(struct xdr_stream *xdr, const struct nlm_cookie *cookie)
102{
103	__be32 *p;
104
105	if (xdr_stream_encode_u32(xdr, cookie->len) < 0)
106		return false;
107	p = xdr_reserve_space(xdr, cookie->len);
108	if (!p)
109		return false;
110	memcpy(p, cookie->data, cookie->len);
111
112	return true;
113}
114
115static inline bool
116svcxdr_decode_owner(struct xdr_stream *xdr, struct xdr_netobj *obj)
117{
118	__be32 *p;
119	u32 len;
120
121	if (xdr_stream_decode_u32(xdr, &len) < 0)
122		return false;
123	if (len > XDR_MAX_NETOBJ)
124		return false;
125	p = xdr_inline_decode(xdr, len);
126	if (!p)
127		return false;
128	obj->len = len;
129	obj->data = (u8 *)p;
130
131	return true;
132}
133
134static inline bool
135svcxdr_encode_owner(struct xdr_stream *xdr, const struct xdr_netobj *obj)
136{
137	if (obj->len > XDR_MAX_NETOBJ)
138		return false;
139	return xdr_stream_encode_opaque(xdr, obj->data, obj->len) > 0;
140}
141
142#endif /* _LOCKD_SVCXDR_H_ */