xref: /freebsd/sys/contrib/openzfs/include/os/linux/spl/rpc/xdr.h (revision 8ddb146abcdf061be9f2c0db7e391697dafad85c)
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 typedef int bool_t;
27 
28 /*
29  * XDR enums and types.
30  */
31 enum xdr_op {
32 	XDR_ENCODE,
33 	XDR_DECODE
34 };
35 
36 struct xdr_ops;
37 
38 typedef struct {
39 	const struct xdr_ops	*x_ops;
40 	    /* Let caller know xdrmem_create() succeeds */
41 	caddr_t		x_addr;	/* Current buffer addr */
42 	caddr_t		x_addr_end;	/* End of the buffer */
43 	enum xdr_op	x_op;	/* Stream direction */
44 } XDR;
45 
46 typedef bool_t (*xdrproc_t)(XDR *xdrs, void *ptr);
47 
48 struct xdr_ops {
49 	bool_t (*xdr_control)(XDR *, int, void *);
50 
51 	bool_t (*xdr_char)(XDR *, char *);
52 	bool_t (*xdr_u_short)(XDR *, unsigned short *);
53 	bool_t (*xdr_u_int)(XDR *, unsigned *);
54 	bool_t (*xdr_u_longlong_t)(XDR *, u_longlong_t *);
55 
56 	bool_t (*xdr_opaque)(XDR *, caddr_t, const uint_t);
57 	bool_t (*xdr_string)(XDR *, char **, const uint_t);
58 	bool_t (*xdr_array)(XDR *, caddr_t *, uint_t *, const uint_t,
59 	    const uint_t, const xdrproc_t);
60 };
61 
62 /*
63  * XDR control operator.
64  */
65 #define	XDR_GET_BYTES_AVAIL 1
66 
67 struct xdr_bytesrec {
68 	bool_t xc_is_last_record;
69 	size_t xc_num_avail;
70 };
71 
72 /*
73  * XDR functions.
74  */
75 void xdrmem_create(XDR *xdrs, const caddr_t addr, const uint_t size,
76     const enum xdr_op op);
77 
78 /* Currently not needed. If needed later, we'll add it to struct xdr_ops */
79 #define	xdr_destroy(xdrs) ((void) 0)
80 
81 #define	xdr_control(xdrs, req, info) \
82 	(xdrs)->x_ops->xdr_control((xdrs), (req), (info))
83 
84 /*
85  * For precaution, the following are defined as static inlines instead of macros
86  * to get some amount of type safety.
87  *
88  * Also, macros wouldn't work in the case where typecasting is done, because it
89  * must be possible to reference the functions' addresses by these names.
90  */
91 static inline bool_t xdr_char(XDR *xdrs, char *cp)
92 {
93 	return (xdrs->x_ops->xdr_char(xdrs, cp));
94 }
95 
96 static inline bool_t xdr_u_short(XDR *xdrs, unsigned short *usp)
97 {
98 	return (xdrs->x_ops->xdr_u_short(xdrs, usp));
99 }
100 
101 static inline bool_t xdr_short(XDR *xdrs, short *sp)
102 {
103 	BUILD_BUG_ON(sizeof (short) != 2);
104 	return (xdrs->x_ops->xdr_u_short(xdrs, (unsigned short *) sp));
105 }
106 
107 static inline bool_t xdr_u_int(XDR *xdrs, unsigned *up)
108 {
109 	return (xdrs->x_ops->xdr_u_int(xdrs, up));
110 }
111 
112 static inline bool_t xdr_int(XDR *xdrs, int *ip)
113 {
114 	BUILD_BUG_ON(sizeof (int) != 4);
115 	return (xdrs->x_ops->xdr_u_int(xdrs, (unsigned *)ip));
116 }
117 
118 static inline bool_t xdr_u_longlong_t(XDR *xdrs, u_longlong_t *ullp)
119 {
120 	return (xdrs->x_ops->xdr_u_longlong_t(xdrs, ullp));
121 }
122 
123 static inline bool_t xdr_longlong_t(XDR *xdrs, longlong_t *llp)
124 {
125 	BUILD_BUG_ON(sizeof (longlong_t) != 8);
126 	return (xdrs->x_ops->xdr_u_longlong_t(xdrs, (u_longlong_t *)llp));
127 }
128 
129 /*
130  * Fixed-length opaque data.
131  */
132 static inline bool_t xdr_opaque(XDR *xdrs, caddr_t cp, const uint_t cnt)
133 {
134 	return (xdrs->x_ops->xdr_opaque(xdrs, cp, cnt));
135 }
136 
137 /*
138  * Variable-length string.
139  * The *sp buffer must have (maxsize + 1) bytes.
140  */
141 static inline bool_t xdr_string(XDR *xdrs, char **sp, const uint_t maxsize)
142 {
143 	return (xdrs->x_ops->xdr_string(xdrs, sp, maxsize));
144 }
145 
146 /*
147  * Variable-length arrays.
148  */
149 static inline bool_t xdr_array(XDR *xdrs, caddr_t *arrp, uint_t *sizep,
150     const uint_t maxsize, const uint_t elsize, const xdrproc_t elproc)
151 {
152 	return xdrs->x_ops->xdr_array(xdrs, arrp, sizep, maxsize, elsize,
153 	    elproc);
154 }
155 
156 #endif /* SPL_RPC_XDR_H */
157