/* $NetBSD: exec_elf32.c,v 1.13 2016/09/21 16:25:41 christos Exp $ */

/*
* Copyright (c) 1996 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. 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.
*
* <<Id: LICENSE_GC,v 1.1 2001/10/01 23:24:05 cgd Exp>>
*/

#include <sys/cdefs.h>
#ifndef lint
__RCSID("$NetBSD: exec_elf32.c,v 1.13 2016/09/21 16:25:41 christos Exp $");
#endif /* not lint */

#ifndef ELFSIZE
#define ELFSIZE         32
#endif

#include <sys/types.h>
#include <stdio.h>
#include <string.h>
#include "extern.h"

#if defined(NLIST_ELF32) || defined(NLIST_ELF64)
#include <sys/exec_elf.h>
#endif

#if (defined(NLIST_ELF32) && (ELFSIZE == 32)) || \
   (defined(NLIST_ELF64) && (ELFSIZE == 64))

#define check(off, size)        ((off < 0) || (off + size > mappedsize))
#define BAD                     do { rv = -1; goto out; } while (0)

int
ELFNAMEEND(check)(const char *mappedfile, size_t mappedsize)
{
       const Elf_Ehdr *ehdrp;
       int rv;

       rv = 0;

       if (check(0, sizeof *ehdrp))
               BAD;
       ehdrp = (const Elf_Ehdr *)&mappedfile[0];

       if (memcmp(ehdrp->e_ident, ELFMAG, SELFMAG) != 0 ||
           ehdrp->e_ident[EI_CLASS] != ELFCLASS)
               BAD;

       switch (ehdrp->e_machine) {
       ELFDEFNNAME(MACHDEP_ID_CASES)

       default:
               BAD;
       }

out:
       return (rv);
}

int
ELFNAMEEND(findoff)(const char *mappedfile, size_t mappedsize, u_long vmaddr,
   size_t *fileoffp, u_long text_addr)
{
       const Elf_Ehdr *ehdrp;
       const Elf_Phdr *phdrp;
       Elf_Off phdr_off;
       Elf_Word phdr_size;
#if (ELFSIZE == 32)
       Elf32_Half nphdr, i;
#elif (ELFSIZE == 64)
       Elf64_Word nphdr, i;
#endif
       int rv;

       rv = 0;

       ehdrp = (const Elf_Ehdr *)&mappedfile[0];
       nphdr = ehdrp->e_phnum;
       phdr_off = ehdrp->e_phoff;
       phdr_size = sizeof(Elf_Phdr) * nphdr;

       if (check(0, phdr_off + phdr_size))
               BAD;
       phdrp = (const Elf_Phdr *)&mappedfile[phdr_off];

#define IS_TEXT(p)      (p.p_flags & PF_X)
#define IS_DATA(p)      (p.p_flags & PF_W)

       for (i = 0; i < nphdr; i++) {
               if ((IS_TEXT(phdrp[i]) || IS_DATA(phdrp[i])) &&
                   phdrp[i].p_vaddr <= vmaddr &&
                   vmaddr < phdrp[i].p_vaddr + phdrp[i].p_filesz) {
                       *fileoffp = vmaddr -
                           phdrp[i].p_vaddr + phdrp[i].p_offset;
                       break;
               }
       }
       if (i == nphdr)
               BAD;

out:
       return (rv);
}

#endif /* include this size of ELF */