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_ */
143