/*-
 * Copyright (c) 2015 Kai Wang
 * 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.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``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 OR CONTRIBUTORS 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 <assert.h>
#include <errno.h>
#include <stdlib.h>
#include <string.h>

#include "_libpe.h"

ELFTC_VCSID("$Id: pe_dos.c 3312 2016-01-10 09:23:51Z kaiwang27 $");

PE_DosHdr *
pe_msdos_header(PE *pe)
{

	if (pe == NULL) {
		errno = EINVAL;
		return (NULL);
	}

	if (pe->pe_dh == NULL) {
		errno = ENOENT;
		return (NULL);
	}

	return (pe->pe_dh);
}

char *
pe_msdos_stub(PE *pe, size_t *len)
{

	if (pe == NULL || len == NULL) {
		errno = EINVAL;
		return (NULL);
	}

	if (pe->pe_stub_ex > 0 &&
	    (pe->pe_flags & LIBPE_F_LOAD_DOS_STUB) == 0) {
		assert((pe->pe_flags & LIBPE_F_SPECIAL_FILE) == 0);
		(void) libpe_read_msdos_stub(pe);
	}

	*len = sizeof(PE_DosHdr) + pe->pe_stub_ex;

	return (pe->pe_stub);
}

int
ps_update_msdos_header(PE *pe, PE_DosHdr *dh)
{

	if (pe == NULL || dh == NULL) {
		errno = EINVAL;
		return (-1);
	}

	if (pe->pe_cmd == PE_C_READ || pe->pe_flags & LIBPE_F_FD_DONE) {
		errno = EACCES;
		return (-1);
	}

	if (pe->pe_dh == NULL) {
		if ((pe->pe_dh = malloc(sizeof(PE_DosHdr))) == NULL) {
			errno = ENOMEM;
			return (-1);
		}
	}

	*pe->pe_dh = *dh;

	pe->pe_flags |= LIBPE_F_DIRTY_DOS_HEADER;

	return (0);
}

int
ps_update_msdos_stub(PE *pe, char *dos_stub, size_t sz)
{

	if (pe == NULL || dos_stub == NULL || sz == 0) {
		errno = EINVAL;
		return (-1);
	}

	if (pe->pe_cmd == PE_C_READ || pe->pe_flags & LIBPE_F_FD_DONE) {
		errno = EACCES;
		return (-1);
	}

	pe->pe_stub_app = dos_stub;
	pe->pe_stub_app_sz = sz;

	return (0);
}