source: rtems-libbsd/services/librpc/src/rpc/pmap_prot2.c @ 20ec9e6

4.1155-freebsd-126-freebsd-12freebsd-9.3
Last change on this file since 20ec9e6 was 20ec9e6, checked in by Joel Sherrill <joel.sherrill@…>, on 08/03/12 at 19:19:49

librpc: Initial addition

This does not currently compile. There is an include file
issue and int32_t is not defined even though stdint.h is included
before its use.

  • Property mode set to 100644
File size: 3.9 KB
Line 
1/*
2 * Sun RPC is a product of Sun Microsystems, Inc. and is provided for
3 * unrestricted use provided that this legend is included on all tape
4 * media and as a part of the software program in whole or part.  Users
5 * may copy or modify Sun RPC without charge, but are not authorized
6 * to license or distribute it to anyone else except as part of a product or
7 * program developed by the user.
8 *
9 * SUN RPC IS PROVIDED AS IS WITH NO WARRANTIES OF ANY KIND INCLUDING THE
10 * WARRANTIES OF DESIGN, MERCHANTIBILITY AND FITNESS FOR A PARTICULAR
11 * PURPOSE, OR ARISING FROM A COURSE OF DEALING, USAGE OR TRADE PRACTICE.
12 *
13 * Sun RPC is provided with no support and without any obligation on the
14 * part of Sun Microsystems, Inc. to assist in its use, correction,
15 * modification or enhancement.
16 *
17 * SUN MICROSYSTEMS, INC. SHALL HAVE NO LIABILITY WITH RESPECT TO THE
18 * INFRINGEMENT OF COPYRIGHTS, TRADE SECRETS OR ANY PATENTS BY SUN RPC
19 * OR ANY PART THEREOF.
20 *
21 * In no event will Sun Microsystems, Inc. be liable for any lost revenue
22 * or profits or other special, indirect and consequential damages, even if
23 * Sun has been advised of the possibility of such damages.
24 *
25 * Sun Microsystems, Inc.
26 * 2550 Garcia Avenue
27 * Mountain View, California  94043
28 */
29
30#if defined(LIBC_SCCS) && !defined(lint)
31/*static char *sccsid = "from: @(#)pmap_prot2.c 1.3 87/08/11 Copyr 1984 Sun Micro";*/
32/*static char *sccsid = "from: @(#)pmap_prot2.c 2.1 88/07/29 4.0 RPCSRC";*/
33static char *rcsid = "$FreeBSD: src/lib/libc/rpc/pmap_prot2.c,v 1.7 1999/08/28 00:00:42 peter Exp $";
34#endif
35
36/*
37 * pmap_prot2.c
38 * Protocol for the local binder service, or pmap.
39 *
40 * Copyright (C) 1984, Sun Microsystems, Inc.
41 */
42
43#ifdef HAVE_CONFIG_H
44#include "config.h"
45#endif
46
47#include <rpc/types.h>
48#include <rpc/xdr.h>
49#include <rpc/pmap_prot.h>
50
51
52/*
53 * What is going on with linked lists? (!)
54 * First recall the link list declaration from pmap_prot.h:
55 *
56 * struct pmaplist {
57 *      struct pmap pml_map;
58 *      struct pmaplist *pml_map;
59 * };
60 *
61 * Compare that declaration with a corresponding xdr declaration that
62 * is (a) pointer-less, and (b) recursive:
63 *
64 * typedef union switch (bool_t) {
65 *
66 *      case TRUE: struct {
67 *              struct pmap;
68 *              pmaplist_t foo;
69 *      };
70 *
71 *      case FALSE: struct {};
72 * } pmaplist_t;
73 *
74 * Notice that the xdr declaration has no nxt pointer while
75 * the C declaration has no bool_t variable.  The bool_t can be
76 * interpreted as ``more data follows me''; if FALSE then nothing
77 * follows this bool_t; if TRUE then the bool_t is followed by
78 * an actual struct pmap, and then (recursively) by the
79 * xdr union, pamplist_t.
80 *
81 * This could be implemented via the xdr_union primitive, though this
82 * would cause a one recursive call per element in the list.  Rather than do
83 * that we can ``unwind'' the recursion
84 * into a while loop and do the union arms in-place.
85 *
86 * The head of the list is what the C programmer wishes to past around
87 * the net, yet is the data that the pointer points to which is interesting;
88 * this sounds like a job for xdr_reference!
89 */
90bool_t
91xdr_pmaplist(
92        XDR *xdrs,
93        struct pmaplist **rp)
94{
95        /*
96         * more_elements is pre-computed in case the direction is
97         * XDR_ENCODE or XDR_FREE.  more_elements is overwritten by
98         * xdr_bool when the direction is XDR_DECODE.
99         */
100        bool_t more_elements;
101        register int freeing = (xdrs->x_op == XDR_FREE);
102        register struct pmaplist **next = NULL;
103
104        while (TRUE) {
105                more_elements = (bool_t)(*rp != NULL);
106                if (! xdr_bool(xdrs, &more_elements))
107                        return (FALSE);
108                if (! more_elements)
109                        return (TRUE);  /* we are done */
110                /*
111                 * the unfortunate side effect of non-recursion is that in
112                 * the case of freeing we must remember the next object
113                 * before we free the current object ...
114                 */
115                if (freeing)
116                        next = &((*rp)->pml_next);
117                if (! xdr_reference(xdrs, (caddr_t *)rp,
118                    (u_int)sizeof(struct pmaplist), (xdrproc_t) xdr_pmap))
119                        return (FALSE);
120                rp = (freeing) ? next : &((*rp)->pml_next);
121        }
122}
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