include/rpc/xdr.h

   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  *  For details, see <http://zfsonlinux.org/>.
   7  *
   8  *  The SPL is free software; you can redistribute it and/or modify it
   9  *  under the terms of the GNU General Public License as published by the
  10  *  Free Software Foundation; either version 2 of the License, or (at your
  11  *  option) any later version.
  12  *
  13  *  The SPL is distributed in the hope that it will be useful, but WITHOUT
  14  *  ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  15  *  FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  16  *  for more details.
  17  *
  18  *  You should have received a copy of the GNU General Public License along
  19  *  with the SPL.  If not, see <http://www.gnu.org/licenses/>.
  20  */
  21
  22 #ifndef _SPL_RPC_XDR_H
  23 #define _SPL_RPC_XDR_H
  24
  25 #include <sys/types.h>
  26 #include <rpc/types.h>
  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 */