/*      $NetBSD: freebsd_exec_elf32.c,v 1.21 2017/08/08 08:04:06 maxv Exp $     */

/*
* Copyright (c) 1993, 1994 Christopher G. Demetriou
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
*    notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
*    notice, this list of conditions and the following disclaimer in the
*    documentation and/or other materials provided with the distribution.
* 3. All advertising materials mentioning features or use of this software
*    must display the following acknowledgement:
*      This product includes software developed by Christopher G. Demetriou.
* 4. The name of the author may not be used to endorse or promote products
*    derived from this software without specific prior written permission
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
* IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/

#include <sys/cdefs.h>
__KERNEL_RCSID(0, "$NetBSD: freebsd_exec_elf32.c,v 1.21 2017/08/08 08:04:06 maxv Exp $");

#include <sys/param.h>
#include <sys/systm.h>
#include <sys/proc.h>
#include <sys/vnode.h>
#include <sys/exec.h>
#ifndef ELFSIZE
#  define ELFSIZE 32
#endif /* !ELFSIZE */
#include <sys/exec_elf.h>

#include <compat/freebsd/freebsd_exec.h>
#include <compat/common/compat_util.h>

#include <compat/freebsd/freebsd_machdep.h>

int
ELFNAME2(freebsd,probe)(struct lwp *l, struct exec_package *epp, void *veh,
   char *itp, vaddr_t *pos)
{
       int error;
       Elf_Ehdr *eh = (Elf_Ehdr *) veh;
       static const char wantBrand[] = FREEBSD_ELF_BRAND_STRING;
       static const char wantInterp[] = FREEBSD_ELF_INTERP_PREFIX_STRING;

       /*
        * Insist that the executable have a brand, and that it be "FreeBSD".
        * Newer FreeBSD binaries have OSABI set to ELFOSABI_FREEBSD. This
        * is arguably broken, but they seem to think they need it, for
        * whatever reason.
        */
#ifndef EI_BRAND
#define EI_BRAND 8
#endif
       if ((eh->e_ident[EI_BRAND] == '\0' ||
            strcmp(&eh->e_ident[EI_BRAND], wantBrand) != 0) &&
               eh->e_ident[EI_OSABI] != ELFOSABI_FREEBSD)
               return ENOEXEC;

       if (itp) {
               if (strncmp(itp, wantInterp, sizeof(wantInterp) - 1))
                       return ENOEXEC;
               if ((error = emul_find_interp(l, epp, itp)))
                       return error;
       }

       return 0;
}