mirror of
https://sourceware.org/git/glibc.git
synced 2024-11-23 05:20:06 +00:00
114 lines
4.0 KiB
C
114 lines
4.0 KiB
C
/*
|
|
* pmap_prot2.c
|
|
* Protocol for the local binder service, or pmap.
|
|
*
|
|
* Copyright (c) 2010, Oracle America, Inc.
|
|
*
|
|
* Redistribution and use in source and binary forms, with or without
|
|
* modification, are permitted provided that the following conditions are
|
|
* met:
|
|
*
|
|
* * Redistributions of source code must retain the above copyright
|
|
* notice, this list of conditions and the following disclaimer.
|
|
* * Redistributions in binary form must reproduce the above
|
|
* copyright notice, this list of conditions and the following
|
|
* disclaimer in the documentation and/or other materials
|
|
* provided with the distribution.
|
|
* * Neither the name of the "Oracle America, Inc." nor the names of its
|
|
* contributors may be used to endorse or promote products derived
|
|
* from this software without specific prior written permission.
|
|
*
|
|
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
|
|
* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
|
|
* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
|
|
* FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
|
|
* COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT,
|
|
* INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
|
|
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE
|
|
* GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
|
|
* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
|
|
* WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
|
|
* NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
|
|
* OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
|
|
*/
|
|
|
|
#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)
|
|
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 = (xdrs->x_op == XDR_FREE);
|
|
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),
|
|
(xdrproc_t) xdr_pmap))
|
|
return FALSE;
|
|
rp = freeing ? &next : &((*rp)->pml_next);
|
|
}
|
|
}
|
|
libc_hidden_nolink (xdr_pmaplist, GLIBC_2_0)
|