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xdr_reference.c revision 1.1 
      1 /*
      2  * Sun RPC is a product of Sun Microsystems, Inc. and is provided for
      3  * unrestricted use provided that this legend is included on all tape
      4  * media and as a part of the software program in whole or part.  Users
      5  * may copy or modify Sun RPC without charge, but are not authorized
      6  * to license or distribute it to anyone else except as part of a product or
      7  * program developed by the user.
      8  *
      9  * SUN RPC IS PROVIDED AS IS WITH NO WARRANTIES OF ANY KIND INCLUDING THE
     10  * WARRANTIES OF DESIGN, MERCHANTIBILITY AND FITNESS FOR A PARTICULAR
     11  * PURPOSE, OR ARISING FROM A COURSE OF DEALING, USAGE OR TRADE PRACTICE.
     12  *
     13  * Sun RPC is provided with no support and without any obligation on the
     14  * part of Sun Microsystems, Inc. to assist in its use, correction,
     15  * modification or enhancement.
     16  *
     17  * SUN MICROSYSTEMS, INC. SHALL HAVE NO LIABILITY WITH RESPECT TO THE
     18  * INFRINGEMENT OF COPYRIGHTS, TRADE SECRETS OR ANY PATENTS BY SUN RPC
     19  * OR ANY PART THEREOF.
     20  *
     21  * In no event will Sun Microsystems, Inc. be liable for any lost revenue
     22  * or profits or other special, indirect and consequential damages, even if
     23  * Sun has been advised of the possibility of such damages.
     24  *
     25  * Sun Microsystems, Inc.
     26  * 2550 Garcia Avenue
     27  * Mountain View, California  94043
     28  */
     29 
     30 #if defined(LIBC_SCCS) && !defined(lint)
     31 /*static char *sccsid = "from: @(#)xdr_reference.c 1.11 87/08/11 SMI";*/
     32 /*static char *sccsid = "from: @(#)xdr_reference.c	2.1 88/07/29 4.0 RPCSRC";*/
     33 static char *rcsid = "$Id: xdr_reference.c,v 1.1 1993/10/07 07:30:29 cgd Exp $";
     34 #endif
     35 
     36 /*
     37  * xdr_reference.c, Generic XDR routines impelmentation.
     38  *
     39  * Copyright (C) 1987, Sun Microsystems, Inc.
     40  *
     41  * These are the "non-trivial" xdr primitives used to serialize and de-serialize
     42  * "pointers".  See xdr.h for more info on the interface to xdr.
     43  */
     44 
     45 #include <stdio.h>
     46 #include <rpc/types.h>
     47 #include <rpc/xdr.h>
     48 
     49 #define LASTUNSIGNED	((u_int)0-1)
     50 
     51 /*
     52  * XDR an indirect pointer
     53  * xdr_reference is for recursively translating a structure that is
     54  * referenced by a pointer inside the structure that is currently being
     55  * translated.  pp references a pointer to storage. If *pp is null
     56  * the  necessary storage is allocated.
     57  * size is the sizeof the referneced structure.
     58  * proc is the routine to handle the referenced structure.
     59  */
     60 bool_t
     61 xdr_reference(xdrs, pp, size, proc)
     62 	register XDR *xdrs;
     63 	caddr_t *pp;		/* the pointer to work on */
     64 	u_int size;		/* size of the object pointed to */
     65 	xdrproc_t proc;		/* xdr routine to handle the object */
     66 {
     67 	register caddr_t loc = *pp;
     68 	register bool_t stat;
     69 
     70 	if (loc == NULL)
     71 		switch (xdrs->x_op) {
     72 		case XDR_FREE:
     73 			return (TRUE);
     74 
     75 		case XDR_DECODE:
     76 			*pp = loc = (caddr_t) mem_alloc(size);
     77 			if (loc == NULL) {
     78 				(void) fprintf(stderr,
     79 				    "xdr_reference: out of memory\n");
     80 				return (FALSE);
     81 			}
     82 			bzero(loc, (int)size);
     83 			break;
     84 	}
     85 
     86 	stat = (*proc)(xdrs, loc, LASTUNSIGNED);
     87 
     88 	if (xdrs->x_op == XDR_FREE) {
     89 		mem_free(loc, size);
     90 		*pp = NULL;
     91 	}
     92 	return (stat);
     93 }
     94 
     95 
     96 /*
     97  * xdr_pointer():
     98  *
     99  * XDR a pointer to a possibly recursive data structure. This
    100  * differs with xdr_reference in that it can serialize/deserialiaze
    101  * trees correctly.
    102  *
    103  *  What's sent is actually a union:
    104  *
    105  *  union object_pointer switch (boolean b) {
    106  *  case TRUE: object_data data;
    107  *  case FALSE: void nothing;
    108  *  }
    109  *
    110  * > objpp: Pointer to the pointer to the object.
    111  * > obj_size: size of the object.
    112  * > xdr_obj: routine to XDR an object.
    113  *
    114  */
    115 bool_t
    116 xdr_pointer(xdrs,objpp,obj_size,xdr_obj)
    117 	register XDR *xdrs;
    118 	char **objpp;
    119 	u_int obj_size;
    120 	xdrproc_t xdr_obj;
    121 {
    122 
    123 	bool_t more_data;
    124 
    125 	more_data = (*objpp != NULL);
    126 	if (! xdr_bool(xdrs,&more_data)) {
    127 		return (FALSE);
    128 	}
    129 	if (! more_data) {
    130 		*objpp = NULL;
    131 		return (TRUE);
    132 	}
    133 	return (xdr_reference(xdrs,objpp,obj_size,xdr_obj));
    134 }
    135