fs3d.c   [plain text]

/***********************************************************************
*                                                                      *
*               This software is part of the ast package               *
*          Copyright (c) 1985-2011 AT&T Intellectual Property          *
*                      and is licensed under the                       *
*                  Common Public License, Version 1.0                  *
*                    by AT&T Intellectual Property                     *
*                                                                      *
*                A copy of the License is available at                 *
*            http://www.opensource.org/licenses/cpl1.0.txt             *
*         (with md5 checksum 059e8cd6165cb4c31e351f2b69388fd9)         *
*                                                                      *
*              Information and Software Systems Research               *
*                            AT&T Research                             *
*                           Florham Park NJ                            *
*                                                                      *
*                 Glenn Fowler <gsf@research.att.com>                  *
*                  David Korn <dgk@research.att.com>                   *
*                   Phong Vo <kpv@research.att.com>                    *
*                                                                      *
***********************************************************************/
#pragma prototyped
/*
 * Glenn Fowler
 * AT&T Bell Laboratories
 *
 * 3d fs operations
 * only active for non-shared 3d library
 */

#define mount	______mount

#include <ast.h>

#undef	mount

#include <fs3d.h>

int
fs3d(register int op)
{
	register int	cur;
	register char*	v;
	char		val[sizeof(FS3D_off) + 8];

	static int	fsview;
	static char	on[] = FS3D_on;
	static char	off[] = FS3D_off;

	if (fsview < 0)
		return 0;

	/*
	 * get the current setting
	 */

	if (!fsview && (!getenv("LD_PRELOAD") || mount("", "", 0, NiL)))
		goto nope;
	if (FS3D_op(op) == FS3D_OP_INIT && mount(FS3D_init, NiL, FS3D_VIEW, NiL))
		goto nope;
	if (mount(on, val, FS3D_VIEW|FS3D_GET|FS3D_SIZE(sizeof(val)), NiL))
		goto nope;
	if (v = strchr(val, ' '))
		v++;
	else
		v = val;
	if (!strcmp(v, on))
		cur = FS3D_ON;
	else if (!strncmp(v, off, sizeof(off) - 1) && v[sizeof(off)] == '=')
		cur = FS3D_LIMIT((int)strtol(v + sizeof(off) + 1, NiL, 0));
	else
		cur = FS3D_OFF;
	if (cur != op)
	{
		switch (FS3D_op(op))
		{
		case FS3D_OP_OFF:
			v = off;
			break;
		case FS3D_OP_ON:
			v = on;
			break;
		case FS3D_OP_LIMIT:
			sfsprintf(val, sizeof(val), "%s=%d", off, FS3D_arg(op));
			v = val;
			break;
		default:
			v = 0;
			break;
		}
		if (v && mount(v, NiL, FS3D_VIEW, NiL))
			goto nope;
	}
	fsview = 1;
	return cur;
 nope:
	fsview = -1;
	return 0;
}

/*
 * user code that includes <fs3d.h> will have mount() mapped to fs3d_mount()
 * this restricts the various "standard" mount prototype conflicts to this spot
 * this means that code that includes <fs3d.h> cannot access the real mount
 * (at least without some additional macro hackery
 */

#undef	mount

extern int	mount(const char*, char*, int, void*);

int
fs3d_mount(const char* source, char* target, int flags, void* data)
{
	return mount(source, target, flags, data);
}