freebsd-dev/lib/libc/rpc/pmap_prot2.c
Bill Paul ad133ed648 Resolve conflicts.
This concludes tonight's entertainment. Once I'm sure I haven't destroyed
the world with all these changes, I'll import the utilities. Everything
should continue to work as before. If it doesn't let me know.

Special thanks to Mark Murray for running a test 'make world' for me to
shake out the bugs, which, hopefully, I have fixed.

(And there was much rejoicing.)
1997-05-28 05:05:31 +00:00

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 1.3 1996/06/10 20:13:05 jraynard 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 = NULL;
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);
}
}