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xdr_reference.c revision 1.2 
      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 1.2 1994/12/04 01:13:44 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 <stdlib.h>
     47 #include <rpc/types.h>
     48 #include <rpc/xdr.h>
     49 
     50 #define LASTUNSIGNED	((u_int)0-1)
     51 
     52 /*
     53  * XDR an indirect pointer
     54  * xdr_reference is for recursively translating a structure that is
     55  * referenced by a pointer inside the structure that is currently being
     56  * translated.  pp references a pointer to storage. If *pp is null
     57  * the  necessary storage is allocated.
     58  * size is the sizeof the referneced structure.
     59  * proc is the routine to handle the referenced structure.
     60  */
     61 bool_t
     62 xdr_reference(xdrs, pp, size, proc)
     63 	register XDR *xdrs;
     64 	caddr_t *pp;		/* the pointer to work on */
     65 	u_int size;		/* size of the object pointed to */
     66 	xdrproc_t proc;		/* xdr routine to handle the object */
     67 {
     68 	register caddr_t loc = *pp;
     69 	register bool_t stat;
     70 
     71 	if (loc == NULL)
     72 		switch (xdrs->x_op) {
     73 		case XDR_FREE:
     74 			return (TRUE);
     75 
     76 		case XDR_DECODE:
     77 			*pp = loc = (caddr_t) mem_alloc(size);
     78 			if (loc == NULL) {
     79 				(void) fprintf(stderr,
     80 				    "xdr_reference: out of memory\n");
     81 				return (FALSE);
     82 			}
     83 			bzero(loc, (int)size);
     84 			break;
     85 	}
     86 
     87 	stat = (*proc)(xdrs, loc, LASTUNSIGNED);
     88 
     89 	if (xdrs->x_op == XDR_FREE) {
     90 		mem_free(loc, size);
     91 		*pp = NULL;
     92 	}
     93 	return (stat);
     94 }
     95 
     96 
     97 /*
     98  * xdr_pointer():
     99  *
    100  * XDR a pointer to a possibly recursive data structure. This
    101  * differs with xdr_reference in that it can serialize/deserialiaze
    102  * trees correctly.
    103  *
    104  *  What's sent is actually a union:
    105  *
    106  *  union object_pointer switch (boolean b) {
    107  *  case TRUE: object_data data;
    108  *  case FALSE: void nothing;
    109  *  }
    110  *
    111  * > objpp: Pointer to the pointer to the object.
    112  * > obj_size: size of the object.
    113  * > xdr_obj: routine to XDR an object.
    114  *
    115  */
    116 bool_t
    117 xdr_pointer(xdrs,objpp,obj_size,xdr_obj)
    118 	register XDR *xdrs;
    119 	char **objpp;
    120 	u_int obj_size;
    121 	xdrproc_t xdr_obj;
    122 {
    123 
    124 	bool_t more_data;
    125 
    126 	more_data = (*objpp != NULL);
    127 	if (! xdr_bool(xdrs,&more_data)) {
    128 		return (FALSE);
    129 	}
    130 	if (! more_data) {
    131 		*objpp = NULL;
    132 		return (TRUE);
    133 	}
    134 	return (xdr_reference(xdrs,objpp,obj_size,xdr_obj));
    135 }
    136