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
21 static inline bool
22 svcxdr_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
34 static inline bool
35 svcxdr_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
47 static inline bool
48 svcxdr_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 */
72 static inline bool
73 svcxdr_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 */
94 out_hpux:
95 cookie->len = 4;
96 memset(cookie->data, 0, 4);
97 return true;
98 }
99
100 static inline bool
101 svcxdr_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
115 static inline bool
116 svcxdr_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
134 static inline bool
135 svcxdr_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
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