xref: /freebsd/sys/contrib/openzfs/include/os/linux/spl/rpc/xdr.h (revision 6580f5c38dd5b01aeeaed16b370f1a12423437f0)
1 /*
2  *  Copyright (c) 2008 Sun Microsystems, Inc.
3  *  Written by Ricardo Correia <Ricardo.M.Correia@Sun.COM>
4  *
5  *  This file is part of the SPL, Solaris Porting Layer.
6  *
7  *  The SPL is free software; you can redistribute it and/or modify it
8  *  under the terms of the GNU General Public License as published by the
9  *  Free Software Foundation; either version 2 of the License, or (at your
10  *  option) any later version.
11  *
12  *  The SPL is distributed in the hope that it will be useful, but WITHOUT
13  *  ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
14  *  FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
15  *  for more details.
16  *
17  *  You should have received a copy of the GNU General Public License along
18  *  with the SPL.  If not, see <http://www.gnu.org/licenses/>.
19  */
20 
21 #ifndef _SPL_RPC_XDR_H
22 #define	_SPL_RPC_XDR_H
23 
24 #include <sys/types.h>
25 
26 /*
27  * XDR enums and types.
28  */
29 enum xdr_op {
30 	XDR_ENCODE,
31 	XDR_DECODE
32 };
33 
34 struct xdr_ops;
35 
36 typedef struct {
37 	const struct xdr_ops	*x_ops;
38 	    /* Let caller know xdrmem_create() succeeds */
39 	caddr_t		x_addr;	/* Current buffer addr */
40 	caddr_t		x_addr_end;	/* End of the buffer */
41 	enum xdr_op	x_op;	/* Stream direction */
42 } XDR;
43 
44 typedef bool_t (*xdrproc_t)(XDR *xdrs, void *ptr);
45 
46 struct xdr_ops {
47 	bool_t (*xdr_control)(XDR *, int, void *);
48 
49 	bool_t (*xdr_char)(XDR *, char *);
50 	bool_t (*xdr_u_short)(XDR *, unsigned short *);
51 	bool_t (*xdr_u_int)(XDR *, unsigned *);
52 	bool_t (*xdr_u_longlong_t)(XDR *, u_longlong_t *);
53 
54 	bool_t (*xdr_opaque)(XDR *, caddr_t, const uint_t);
55 	bool_t (*xdr_string)(XDR *, char **, const uint_t);
56 	bool_t (*xdr_array)(XDR *, caddr_t *, uint_t *, const uint_t,
57 	    const uint_t, const xdrproc_t);
58 };
59 
60 /*
61  * XDR control operator.
62  */
63 #define	XDR_GET_BYTES_AVAIL 1
64 
65 struct xdr_bytesrec {
66 	bool_t xc_is_last_record;
67 	size_t xc_num_avail;
68 };
69 
70 /*
71  * XDR functions.
72  */
73 void xdrmem_create(XDR *xdrs, const caddr_t addr, const uint_t size,
74     const enum xdr_op op);
75 
76 #define	xdr_control(xdrs, req, info) \
77 	(xdrs)->x_ops->xdr_control((xdrs), (req), (info))
78 
79 /*
80  * For precaution, the following are defined as static inlines instead of macros
81  * to get some amount of type safety.
82  *
83  * Also, macros wouldn't work in the case where typecasting is done, because it
84  * must be possible to reference the functions' addresses by these names.
85  */
86 static inline bool_t xdr_char(XDR *xdrs, char *cp)
87 {
88 	return (xdrs->x_ops->xdr_char(xdrs, cp));
89 }
90 
91 static inline bool_t xdr_u_short(XDR *xdrs, unsigned short *usp)
92 {
93 	return (xdrs->x_ops->xdr_u_short(xdrs, usp));
94 }
95 
96 static inline bool_t xdr_short(XDR *xdrs, short *sp)
97 {
98 	BUILD_BUG_ON(sizeof (short) != 2);
99 	return (xdrs->x_ops->xdr_u_short(xdrs, (unsigned short *) sp));
100 }
101 
102 static inline bool_t xdr_u_int(XDR *xdrs, unsigned *up)
103 {
104 	return (xdrs->x_ops->xdr_u_int(xdrs, up));
105 }
106 
107 static inline bool_t xdr_int(XDR *xdrs, int *ip)
108 {
109 	BUILD_BUG_ON(sizeof (int) != 4);
110 	return (xdrs->x_ops->xdr_u_int(xdrs, (unsigned *)ip));
111 }
112 
113 static inline bool_t xdr_u_longlong_t(XDR *xdrs, u_longlong_t *ullp)
114 {
115 	return (xdrs->x_ops->xdr_u_longlong_t(xdrs, ullp));
116 }
117 
118 static inline bool_t xdr_longlong_t(XDR *xdrs, longlong_t *llp)
119 {
120 	BUILD_BUG_ON(sizeof (longlong_t) != 8);
121 	return (xdrs->x_ops->xdr_u_longlong_t(xdrs, (u_longlong_t *)llp));
122 }
123 
124 /*
125  * Fixed-length opaque data.
126  */
127 static inline bool_t xdr_opaque(XDR *xdrs, caddr_t cp, const uint_t cnt)
128 {
129 	return (xdrs->x_ops->xdr_opaque(xdrs, cp, cnt));
130 }
131 
132 /*
133  * Variable-length string.
134  * The *sp buffer must have (maxsize + 1) bytes.
135  */
136 static inline bool_t xdr_string(XDR *xdrs, char **sp, const uint_t maxsize)
137 {
138 	return (xdrs->x_ops->xdr_string(xdrs, sp, maxsize));
139 }
140 
141 /*
142  * Variable-length arrays.
143  */
144 static inline bool_t xdr_array(XDR *xdrs, caddr_t *arrp, uint_t *sizep,
145     const uint_t maxsize, const uint_t elsize, const xdrproc_t elproc)
146 {
147 	return xdrs->x_ops->xdr_array(xdrs, arrp, sizep, maxsize, elsize,
148 	    elproc);
149 }
150 
151 #endif /* SPL_RPC_XDR_H */
152