1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
|
/* $NetBSD: pmap_prot2.c,v 1.14 2000/07/06 03:10:34 christos Exp $ */
/*
* Sun RPC is a product of Sun Microsystems, Inc. and is provided for
* unrestricted use provided that this legend is included on all tape
* media and as a part of the software program in whole or part. Users
* may copy or modify Sun RPC without charge, but are not authorized
* to license or distribute it to anyone else except as part of a product or
* program developed by the user.
*
* SUN RPC IS PROVIDED AS IS WITH NO WARRANTIES OF ANY KIND INCLUDING THE
* WARRANTIES OF DESIGN, MERCHANTIBILITY AND FITNESS FOR A PARTICULAR
* PURPOSE, OR ARISING FROM A COURSE OF DEALING, USAGE OR TRADE PRACTICE.
*
* Sun RPC is provided with no support and without any obligation on the
* part of Sun Microsystems, Inc. to assist in its use, correction,
* modification or enhancement.
*
* SUN MICROSYSTEMS, INC. SHALL HAVE NO LIABILITY WITH RESPECT TO THE
* INFRINGEMENT OF COPYRIGHTS, TRADE SECRETS OR ANY PATENTS BY SUN RPC
* OR ANY PART THEREOF.
*
* In no event will Sun Microsystems, Inc. be liable for any lost revenue
* or profits or other special, indirect and consequential damages, even if
* Sun has been advised of the possibility of such damages.
*
* Sun Microsystems, Inc.
* 2550 Garcia Avenue
* Mountain View, California 94043
*/
#if defined(LIBC_SCCS) && !defined(lint)
static char *sccsid = "@(#)pmap_prot2.c 1.3 87/08/11 Copyr 1984 Sun Micro";
static char *sccsid = "@(#)pmap_prot2.c 2.1 88/07/29 4.0 RPCSRC";
#endif
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");
/*
* pmap_prot2.c
* Protocol for the local binder service, or pmap.
*
* Copyright (C) 1984, Sun Microsystems, Inc.
*/
#include "namespace.h"
#include <assert.h>
#include <rpc/types.h>
#include <rpc/xdr.h>
#include <rpc/pmap_prot.h>
#include "un-namespace.h"
/*
* What is going on with linked lists? (!)
* First recall the link list declaration from pmap_prot.h:
*
* struct pmaplist {
* struct pmap pml_map;
* struct pmaplist *pml_map;
* };
*
* Compare that declaration with a corresponding xdr declaration that
* is (a) pointer-less, and (b) recursive:
*
* typedef union switch (bool_t) {
*
* case TRUE: struct {
* struct pmap;
* pmaplist_t foo;
* };
*
* case FALSE: struct {};
* } pmaplist_t;
*
* Notice that the xdr declaration has no nxt pointer while
* the C declaration has no bool_t variable. The bool_t can be
* interpreted as ``more data follows me''; if FALSE then nothing
* follows this bool_t; if TRUE then the bool_t is followed by
* an actual struct pmap, and then (recursively) by the
* xdr union, pamplist_t.
*
* This could be implemented via the xdr_union primitive, though this
* would cause a one recursive call per element in the list. Rather than do
* that we can ``unwind'' the recursion
* into a while loop and do the union arms in-place.
*
* The head of the list is what the C programmer wishes to past around
* the net, yet is the data that the pointer points to which is interesting;
* this sounds like a job for xdr_reference!
*/
bool_t
xdr_pmaplist(xdrs, rp)
XDR *xdrs;
struct pmaplist **rp;
{
/*
* more_elements is pre-computed in case the direction is
* XDR_ENCODE or XDR_FREE. more_elements is overwritten by
* xdr_bool when the direction is XDR_DECODE.
*/
bool_t more_elements;
int freeing;
struct pmaplist **next = NULL; /* pacify gcc */
assert(xdrs != NULL);
assert(rp != NULL);
freeing = (xdrs->x_op == XDR_FREE);
for (;;) {
more_elements = (bool_t)(*rp != NULL);
if (! xdr_bool(xdrs, &more_elements))
return (FALSE);
if (! more_elements)
return (TRUE); /* we are done */
/*
* the unfortunate side effect of non-recursion is that in
* the case of freeing we must remember the next object
* before we free the current object ...
*/
if (freeing)
next = &((*rp)->pml_next);
if (! xdr_reference(xdrs, (caddr_t *)rp,
(u_int)sizeof(struct pmaplist), (xdrproc_t)xdr_pmap))
return (FALSE);
rp = (freeing) ? next : &((*rp)->pml_next);
}
}
/*
* xdr_pmaplist_ptr() is specified to take a PMAPLIST *, but is identical in
* functionality to xdr_pmaplist().
*/
bool_t
xdr_pmaplist_ptr(xdrs, rp)
XDR *xdrs;
struct pmaplist *rp;
{
return xdr_pmaplist(xdrs, (struct pmaplist **)(void *)rp);
}
|