diff options
Diffstat (limited to 'REORG.TODO/sunrpc/pmap_prot2.c')
| -rw-r--r-- | REORG.TODO/sunrpc/pmap_prot2.c | 112 |
1 files changed, 112 insertions, 0 deletions
diff --git a/REORG.TODO/sunrpc/pmap_prot2.c b/REORG.TODO/sunrpc/pmap_prot2.c new file mode 100644 index 0000000000..c414db0298 --- /dev/null +++ b/REORG.TODO/sunrpc/pmap_prot2.c @@ -0,0 +1,112 @@ +/* + * 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> +#include <shlib-compat.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 (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_sunrpc (xdr_pmaplist, GLIBC_2_0) |