/***************************************************************/

/*  perk: PE Resource Kit                                      */

/*  Copyright (C) 2015--2021  SysDeer Technologies, LLC        */

/*  Released under GPLv2 and GPLv3; see COPYING.PERK.          */

/***************************************************************/

#include <string.h>

#include <perk/perk.h>

#include <perk/perk_consts.h>

#include <perk/perk_structs.h>

#include "perk_endian_impl.h"

#include "perk_reader_impl.h"

static int pe_read_optional_header_structs(const union pe_raw_opt_hdr * p, struct pe_meta_opt_hdr * m)

{

	unsigned int			i;

	struct pe_block *		pdir;

	const  unsigned char *		mark;

	const  unsigned char *		etbl;

	struct pe_raw_opt_hdr_std *	astd;

	struct pe_raw_opt_hdr_vers *	avers;

	struct pe_raw_opt_hdr_align *	aalign;

	struct pe_raw_opt_hdr_img *	aimg;

	struct pe_raw_opt_hdr_ldr *	aldr;

	m->oh_std.coh_magic = pe_read_short(p->opt_hdr_32.coh_magic);

	switch (m->oh_std.coh_magic) {

		case PE_MAGIC_PE32:

			astd	= (struct pe_raw_opt_hdr_std *)p;

			avers	= (struct pe_raw_opt_hdr_vers *)&p->opt_hdr_32.coh_major_os_ver;

			aalign	= (struct pe_raw_opt_hdr_align *)&p->opt_hdr_32.coh_section_align;

			aimg	= (struct pe_raw_opt_hdr_img *)&p->opt_hdr_32.coh_size_of_image;

			aldr	= (struct pe_raw_opt_hdr_ldr *)&p->opt_hdr_32.coh_loader_flags;

			etbl	= p->opt_hdr_32.coh_export_tbl;

			break;

		case PE_MAGIC_PE32_PLUS:

			astd	= (struct pe_raw_opt_hdr_std *)p;

			avers	= (struct pe_raw_opt_hdr_vers *)&p->opt_hdr_64.coh_major_os_ver;

			aalign	= (struct pe_raw_opt_hdr_align *)&p->opt_hdr_64.coh_section_align;

			aimg	= (struct pe_raw_opt_hdr_img *)&p->opt_hdr_64.coh_size_of_image;

			aldr	= (struct pe_raw_opt_hdr_ldr *)&p->opt_hdr_64.coh_loader_flags;

			etbl	= p->opt_hdr_64.coh_export_tbl;

			break;

		default:

			return PERK_ERR_BAD_IMAGE_TYPE;

	}

	/* std */

	m->oh_std.coh_major_linker_ver		= astd->coh_major_linker_ver[0];

	m->oh_std.coh_minor_linker_ver		= astd->coh_minor_linker_ver[0];

	m->oh_std.coh_size_of_code		= pe_read_long(astd->coh_size_of_code);

	m->oh_std.coh_size_of_inited_data	= pe_read_long(astd->coh_size_of_inited_data);

	m->oh_std.coh_size_of_uninited_data	= pe_read_long(astd->coh_size_of_uninited_data);

	m->oh_std.coh_entry_point		= pe_read_long(astd->coh_entry_point);

	m->oh_std.coh_base_of_code		= pe_read_long(astd->coh_base_of_code);

	/* vers */

	m->oh_vers.coh_major_os_ver		= pe_read_short(avers->coh_major_os_ver);

	m->oh_vers.coh_minor_os_ver		= pe_read_short(avers->coh_minor_os_ver);

	m->oh_vers.coh_major_image_ver		= pe_read_short(avers->coh_major_image_ver);

	m->oh_vers.coh_minor_image_ver		= pe_read_short(avers->coh_minor_image_ver);

	m->oh_vers.coh_major_subsys_ver		= pe_read_short(avers->coh_major_subsys_ver);

	m->oh_vers.coh_minor_subsys_ver		= pe_read_short(avers->coh_minor_subsys_ver);

	m->oh_vers.coh_win32_ver		= pe_read_long(avers->coh_win32_ver);

	/* align */

	m->oh_align.coh_section_align		= pe_read_long(aalign->coh_section_align);

	m->oh_align.coh_file_align		= pe_read_long(aalign->coh_file_align);

	/* img */

	m->oh_img.coh_size_of_image		= pe_read_long(aimg->coh_size_of_image);

	m->oh_img.coh_size_of_headers		= pe_read_long(aimg->coh_size_of_headers);

	m->oh_img.coh_checksum			= pe_read_long(aimg->coh_checksum);

	m->oh_img.coh_subsystem			= pe_read_short(aimg->coh_subsystem);

	m->oh_img.coh_dll_characteristics	= pe_read_short(aimg->coh_dll_characteristics);

	/* ldr */

	m->oh_ldr.coh_loader_flags		= pe_read_long(aldr->coh_loader_flags);

	m->oh_ldr.coh_rva_and_sizes		= pe_read_long(aldr->coh_rva_and_sizes);

	/* dirs */

	if (m->oh_ldr.coh_rva_and_sizes > 0x10)

		return PERK_ERR_BAD_IMAGE_TYPE;

	if (m->oh_ldr.coh_rva_and_sizes < 0x10)

		memset(&m->oh_dirs,0,sizeof(m->oh_dirs));

	mark = etbl;

	pdir = &m->oh_dirs.coh_export_tbl;

	for (i=0; i<m->oh_ldr.coh_rva_and_sizes; i++) {

		pdir[i].dh_rva  = pe_read_long(&mark[i*8]);

		pdir[i].dh_size = pe_read_long(&mark[i*8+4]);

	}

	return 0;

}

int pe_read_optional_header(const union pe_raw_opt_hdr * p, struct pe_meta_opt_hdr * m)

{

	int ret;

	if ((ret = pe_read_optional_header_structs(p,m)))

		return ret;

	switch (m->oh_std.coh_magic) {

		case PE_MAGIC_PE32:

			m->oh_mem.coh_base_of_data          = pe_read_long(p->opt_hdr_32.coh_base_of_data);

			m->oh_mem.coh_image_base            = pe_read_long(p->opt_hdr_32.coh_image_base);

			m->oh_mem.coh_size_of_stack_reserve = pe_read_long(p->opt_hdr_32.coh_size_of_stack_reserve);

			m->oh_mem.coh_size_of_stack_commit  = pe_read_long(p->opt_hdr_32.coh_size_of_stack_commit);

			m->oh_mem.coh_size_of_heap_reserve  = pe_read_long(p->opt_hdr_32.coh_size_of_heap_reserve);

			m->oh_mem.coh_size_of_heap_commit   = pe_read_long(p->opt_hdr_32.coh_size_of_heap_commit);

			break;

		case PE_MAGIC_PE32_PLUS:

			m->oh_mem.coh_base_of_data          = (uint64_t)-1;

			m->oh_mem.coh_image_base            = pe_read_quad(p->opt_hdr_64.coh_image_base);

			m->oh_mem.coh_size_of_stack_reserve = pe_read_quad(p->opt_hdr_64.coh_size_of_stack_reserve);

			m->oh_mem.coh_size_of_stack_commit  = pe_read_quad(p->opt_hdr_64.coh_size_of_stack_commit);

			m->oh_mem.coh_size_of_heap_reserve  = pe_read_quad(p->opt_hdr_64.coh_size_of_heap_reserve);

			m->oh_mem.coh_size_of_heap_commit   = pe_read_quad(p->opt_hdr_64.coh_size_of_heap_commit);

			break;

	}

	return 0;

}