119 lines
3.8 KiB
C
119 lines
3.8 KiB
C
/*
|
|
* 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 = "from: @(#)pmap_prot2.c 1.3 87/08/11 Copyr 1984 Sun Micro";*/
|
|
/*static char *sccsid = "from: @(#)pmap_prot2.c 2.1 88/07/29 4.0 RPCSRC";*/
|
|
static char *rcsid = "$Id: pmap_prot2.c,v 1.1 1993/10/07 07:30:05 cgd Exp $";
|
|
#endif
|
|
|
|
/*
|
|
* pmap_prot2.c
|
|
* Protocol for the local binder service, or pmap.
|
|
*
|
|
* Copyright (C) 1984, Sun Microsystems, Inc.
|
|
*/
|
|
|
|
#include <rpc/types.h>
|
|
#include <rpc/xdr.h>
|
|
#include <rpc/pmap_prot.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)
|
|
register XDR *xdrs;
|
|
register 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;
|
|
register int freeing = (xdrs->x_op == XDR_FREE);
|
|
register struct pmaplist **next;
|
|
|
|
while (TRUE) {
|
|
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), xdr_pmap))
|
|
return (FALSE);
|
|
rp = (freeing) ? next : &((*rp)->pml_next);
|
|
}
|
|
}
|