usr/src/lib/libast/common/misc/fs3d.c

   1 /***********************************************************************
   2 *                                                                      *
   3 *               This software is part of the ast package               *
   4 *          Copyright (c) 1985-2010 AT&T Intellectual Property          *
   5 *                      and is licensed under the                       *
   6 *                  Common Public License, Version 1.0                  *
   7 *                    by AT&T Intellectual Property                     *
   8 *                                                                      *
   9 *                A copy of the License is available at                 *
  10 *            http://www.opensource.org/licenses/cpl1.0.txt             *
  11 *         (with md5 checksum 059e8cd6165cb4c31e351f2b69388fd9)         *
  12 *                                                                      *
  13 *              Information and Software Systems Research               *
  14 *                            AT&T Research                             *
  15 *                           Florham Park NJ                            *
  16 *                                                                      *
  17 *                 Glenn Fowler <gsf@research.att.com>                  *
  18 *                  David Korn <dgk@research.att.com>                   *
  19 *                   Phong Vo <kpv@research.att.com>                    *
  20 *                                                                      *
  21 ***********************************************************************/
  22 #pragma prototyped
  23 /*
  24  * Glenn Fowler
  25  * AT&T Bell Laboratories
  26  *
  27  * 3d fs operations
  28  * only active for non-shared 3d library
  29  */
  30
  31 #define mount   ______mount
  32
  33 #include <ast.h>
  34
  35 #undef  mount
  36
  37 #include <fs3d.h>
  38
  39 int
  40 fs3d(register int op)
  41 {
  42         register int    cur;
  43         register char*  v;
  44         char            val[sizeof(FS3D_off) + 8];
  45
  46         static int      fsview;
  47         static char     on[] = FS3D_on;
  48         static char     off[] = FS3D_off;
  49
  50         if (fsview < 0)
  51                 return 0;
  52
  53         /*
  54          * get the current setting
  55          */
  56
  57         if (!fsview && (!getenv("LD_PRELOAD") || mount("", "", 0, NiL)))
  58                 goto nope;
  59         if (FS3D_op(op) == FS3D_OP_INIT && mount(FS3D_init, NiL, FS3D_VIEW, NiL))
  60                 goto nope;
  61         if (mount(on, val, FS3D_VIEW|FS3D_GET|FS3D_SIZE(sizeof(val)), NiL))
  62                 goto nope;
  63         if (v = strchr(val, ' '))
  64                 v++;
  65         else
  66                 v = val;
  67         if (!strcmp(v, on))
  68                 cur = FS3D_ON;
  69         else if (!strncmp(v, off, sizeof(off) - 1) && v[sizeof(off)] == '=')
  70                 cur = FS3D_LIMIT((int)strtol(v + sizeof(off) + 1, NiL, 0));
  71         else
  72                 cur = FS3D_OFF;
  73         if (cur != op)
  74         {
  75                 switch (FS3D_op(op))
  76                 {
  77                 case FS3D_OP_OFF:
  78                         v = off;
  79                         break;
  80                 case FS3D_OP_ON:
  81                         v = on;
  82                         break;
  83                 case FS3D_OP_LIMIT:
  84                         sfsprintf(val, sizeof(val), "%s=%d", off, FS3D_arg(op));
  85                         v = val;
  86                         break;
  87                 default:
  88                         v = 0;
  89                         break;
  90                 }
  91                 if (v && mount(v, NiL, FS3D_VIEW, NiL))
  92                         goto nope;
  93         }
  94         fsview = 1;
  95         return cur;
  96  nope:
  97         fsview = -1;
  98         return 0;
  99 }
 100
 101 /*
 102  * user code that includes <fs3d.h> will have mount() mapped to fs3d_mount()
 103  * this restricts the various "standard" mount prototype conflicts to this spot
 104  * this means that code that includes <fs3d.h> cannot access the real mount
 105  * (at least without some additional macro hackery
 106  */
 107
 108 #undef  mount
 109
 110 extern int      mount(const char*, char*, int, void*);
 111
 112 int
 113 fs3d_mount(const char* source, char* target, int flags, void* data)
 114 {
 115         return mount(source, target, flags, data);
 116 }