xref: /freebsd/sys/contrib/openzfs/include/os/linux/spl/rpc/xdr.h (revision c66ec88fed842fbaad62c30d510644ceb7bd2d71)
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 	struct xdr_ops	*x_ops;	/* Let caller know xdrmem_create() succeeds */
40 	caddr_t		x_addr;	/* Current buffer addr */
41 	caddr_t		x_addr_end;	/* End of the buffer */
42 	enum xdr_op	x_op;	/* Stream direction */
43 } XDR;
44 
45 typedef bool_t (*xdrproc_t)(XDR *xdrs, void *ptr);
46 
47 struct xdr_ops {
48 	bool_t (*xdr_control)(XDR *, int, void *);
49 
50 	bool_t (*xdr_char)(XDR *, char *);
51 	bool_t (*xdr_u_short)(XDR *, unsigned short *);
52 	bool_t (*xdr_u_int)(XDR *, unsigned *);
53 	bool_t (*xdr_u_longlong_t)(XDR *, u_longlong_t *);
54 
55 	bool_t (*xdr_opaque)(XDR *, caddr_t, const uint_t);
56 	bool_t (*xdr_string)(XDR *, char **, const uint_t);
57 	bool_t (*xdr_array)(XDR *, caddr_t *, uint_t *, const uint_t,
58 	    const uint_t, const xdrproc_t);
59 };
60 
61 /*
62  * XDR control operator.
63  */
64 #define	XDR_GET_BYTES_AVAIL 1
65 
66 struct xdr_bytesrec {
67 	bool_t xc_is_last_record;
68 	size_t xc_num_avail;
69 };
70 
71 /*
72  * XDR functions.
73  */
74 void xdrmem_create(XDR *xdrs, const caddr_t addr, const uint_t size,
75     const enum xdr_op op);
76 
77 /* Currently not needed. If needed later, we'll add it to struct xdr_ops */
78 #define	xdr_destroy(xdrs) ((void) 0)
79 
80 #define	xdr_control(xdrs, req, info) \
81 	(xdrs)->x_ops->xdr_control((xdrs), (req), (info))
82 
83 /*
84  * For precaution, the following are defined as static inlines instead of macros
85  * to get some amount of type safety.
86  *
87  * Also, macros wouldn't work in the case where typecasting is done, because it
88  * must be possible to reference the functions' addresses by these names.
89  */
90 static inline bool_t xdr_char(XDR *xdrs, char *cp)
91 {
92 	return (xdrs->x_ops->xdr_char(xdrs, cp));
93 }
94 
95 static inline bool_t xdr_u_short(XDR *xdrs, unsigned short *usp)
96 {
97 	return (xdrs->x_ops->xdr_u_short(xdrs, usp));
98 }
99 
100 static inline bool_t xdr_short(XDR *xdrs, short *sp)
101 {
102 	BUILD_BUG_ON(sizeof (short) != 2);
103 	return (xdrs->x_ops->xdr_u_short(xdrs, (unsigned short *) sp));
104 }
105 
106 static inline bool_t xdr_u_int(XDR *xdrs, unsigned *up)
107 {
108 	return (xdrs->x_ops->xdr_u_int(xdrs, up));
109 }
110 
111 static inline bool_t xdr_int(XDR *xdrs, int *ip)
112 {
113 	BUILD_BUG_ON(sizeof (int) != 4);
114 	return (xdrs->x_ops->xdr_u_int(xdrs, (unsigned *)ip));
115 }
116 
117 static inline bool_t xdr_u_longlong_t(XDR *xdrs, u_longlong_t *ullp)
118 {
119 	return (xdrs->x_ops->xdr_u_longlong_t(xdrs, ullp));
120 }
121 
122 static inline bool_t xdr_longlong_t(XDR *xdrs, longlong_t *llp)
123 {
124 	BUILD_BUG_ON(sizeof (longlong_t) != 8);
125 	return (xdrs->x_ops->xdr_u_longlong_t(xdrs, (u_longlong_t *)llp));
126 }
127 
128 /*
129  * Fixed-length opaque data.
130  */
131 static inline bool_t xdr_opaque(XDR *xdrs, caddr_t cp, const uint_t cnt)
132 {
133 	return (xdrs->x_ops->xdr_opaque(xdrs, cp, cnt));
134 }
135 
136 /*
137  * Variable-length string.
138  * The *sp buffer must have (maxsize + 1) bytes.
139  */
140 static inline bool_t xdr_string(XDR *xdrs, char **sp, const uint_t maxsize)
141 {
142 	return (xdrs->x_ops->xdr_string(xdrs, sp, maxsize));
143 }
144 
145 /*
146  * Variable-length arrays.
147  */
148 static inline bool_t xdr_array(XDR *xdrs, caddr_t *arrp, uint_t *sizep,
149     const uint_t maxsize, const uint_t elsize, const xdrproc_t elproc)
150 {
151 	return xdrs->x_ops->xdr_array(xdrs, arrp, sizep, maxsize, elsize,
152 	    elproc);
153 }
154 
155 #endif /* SPL_RPC_XDR_H */
156