/* $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 */