OSX/libsecurityd/lib/sec_xdr_reference.c

   1 /*
   2  * Copyright (c) 2006,2011,2013-2014 Apple Inc. All Rights Reserved.
   3  *
   4  * @APPLE_LICENSE_HEADER_START@
   5  *
   6  * This file contains Original Code and/or Modifications of Original Code
   7  * as defined in and that are subject to the Apple Public Source License
   8  * Version 2.0 (the 'License'). You may not use this file except in
   9  * compliance with the License. Please obtain a copy of the License at
  10  * http://www.opensource.apple.com/apsl/ and read it before using this
  11  * file.
  12  *
  13  * The Original Code and all software distributed under the License are
  14  * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
  15  * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
  16  * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
  17  * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
  18  * Please see the License for the specific language governing rights and
  19  * limitations under the License.
  20  *
  21  * @APPLE_LICENSE_HEADER_END@
  22  */
  23
  24 /*      $NetBSD: xdr_reference.c,v 1.13 2000/01/22 22:19:18 mycroft Exp $ */
  25
  26 /*
  27  * Sun RPC is a product of Sun Microsystems, Inc. and is provided for
  28  * unrestricted use provided that this legend is included on all tape
  29  * media and as a part of the software program in whole or part.  Users
  30  * may copy or modify Sun RPC without charge, but are not authorized
  31  * to license or distribute it to anyone else except as part of a product or
  32  * program developed by the user.
  33  *
  34  * SUN RPC IS PROVIDED AS IS WITH NO WARRANTIES OF ANY KIND INCLUDING THE
  35  * WARRANTIES OF DESIGN, MERCHANTIBILITY AND FITNESS FOR A PARTICULAR
  36  * PURPOSE, OR ARISING FROM A COURSE OF DEALING, USAGE OR TRADE PRACTICE.
  37  *
  38  * Sun RPC is provided with no support and without any obligation on the
  39  * part of Sun Microsystems, Inc. to assist in its use, correction,
  40  * modification or enhancement.
  41  *
  42  * SUN MICROSYSTEMS, INC. SHALL HAVE NO LIABILITY WITH RESPECT TO THE
  43  * INFRINGEMENT OF COPYRIGHTS, TRADE SECRETS OR ANY PATENTS BY SUN RPC
  44  * OR ANY PART THEREOF.
  45  *
  46  * In no event will Sun Microsystems, Inc. be liable for any lost revenue
  47  * or profits or other special, indirect and consequential damages, even if
  48  * Sun has been advised of the possibility of such damages.
  49  *
  50  * Sun Microsystems, Inc.
  51  * 2550 Garcia Avenue
  52  * Mountain View, California  94043
  53  */
  54
  55 #include <sys/cdefs.h>
  56 #if defined(LIBC_SCCS) && !defined(lint)
  57 static char *sccsid = "@(#)xdr_reference.c 1.11 87/08/11 SMI";
  58 static char *sccsid = "@(#)xdr_reference.c      2.1 88/07/29 4.0 RPCSRC";
  59 static char *rcsid = "$FreeBSD: src/lib/libc/xdr/xdr_reference.c,v 1.11 2002/03/22 21:53:26 obrien Exp $";
  60 #endif
  61 #include <sys/cdefs.h>
  62 #include <assert.h>
  63 /*
  64  * xdr_reference.c, Generic XDR routines impelmentation.
  65  *
  66  * Copyright (C) 1987, Sun Microsystems, Inc.
  67  *
  68  * These are the "non-trivial" xdr primitives used to serialize and de-serialize
  69  * "pointers".  See xdr.h for more info on the interface to xdr.
  70  */
  71
  72 #include <err.h>
  73 #include <stdio.h>
  74 #include <stdlib.h>
  75 #include <string.h>
  76
  77 #include "sec_xdr.h"
  78
  79 /*
  80  * XDR an indirect pointer
  81  * xdr_reference is for recursively translating a structure that is
  82  * referenced by a pointer inside the structure that is currently being
  83  * translated.  pp references a pointer to storage. If *pp is null
  84  * the  necessary storage is allocated.
  85  * size is the sizeof the referneced structure.
  86  * proc is the routine to handle the referenced structure.
  87  */
  88 bool_t
  89 sec_xdr_reference(XDR *xdrs, uint8_t **pp, u_int size, xdrproc_t proc)
  90 {
  91     uint8_t *loc = pp ? *pp : NULL;
  92     bool_t stat;
  93
  94     if (size > 1024) {
  95         // Structure suspiciously large: 1024 is arbitrary upper bound
  96         // for struct sizes (non-nested size)
  97         assert(FALSE);
  98         return (FALSE);
  99     }
 100     uint8_t obj[size];
 101
 102     bool_t sizeof_alloc = sec_xdr_arena_size_allocator(xdrs);
 103
 104     if (loc == NULL)
 105             switch (xdrs->x_op) {
 106             case XDR_FREE:
 107                 return (TRUE);
 108             case XDR_DECODE:
 109                 {
 110                     if (!sec_mem_alloc(xdrs, size, &loc))
 111                         return (FALSE);
 112                                         if (!loc) {
 113                         memset(obj, 0, size);
 114                                                 loc = &obj[0];
 115                     }
 116                                         if (!sizeof_alloc)
 117                                                 *pp = loc;
 118                                         break;
 119                 }
 120             case XDR_ENCODE:
 121                 break;
 122             }
 123
 124     stat = (*proc)(xdrs, loc, 0);
 125
 126     if (xdrs->x_op == XDR_FREE) {
 127         sec_mem_free(xdrs, loc, size);
 128         *pp = NULL;
 129     }
 130     return (stat);
 131 }
 132
 133
 134 bool_t
 135 sec_xdr_pointer(XDR *xdrs, uint8_t **objpp, u_int obj_size, xdrproc_t xdr_obj)
 136 {
 137     bool_t more_data;
 138
 139     more_data = (objpp ? (*objpp != NULL) : FALSE);
 140     if (! xdr_bool(xdrs,&more_data))
 141         return (FALSE);
 142
 143     bool_t sizeof_alloc = sec_xdr_arena_size_allocator(xdrs);
 144
 145     if (! more_data) {
 146         if ((xdrs->x_op == XDR_DECODE) && !sizeof_alloc)
 147             *objpp = NULL;
 148         return (TRUE);
 149     }
 150     return (sec_xdr_reference(xdrs,objpp,obj_size,xdr_obj));
 151 }
 152
 153 /**
 154  * This is almost a straight copy of the standard implementation, except
 155  * that all calls made that allocate memory can defer to an alternate
 156  * mechanism, with the purpose to allocate from one block of memory on
 157  * *decode*
 158  */