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

/*  pemagination: a (virtual) tour into portable bits and executable bytes   */

/*  Copyright (C) 2013--2020  Z. Gilboa                                      */

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

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

#include <psxtypes/psxtypes.h>

#include <pemagine/pemagine.h>

struct pe_symbol_name_ctx {

	const void *	addr;

	char *		name;

};

static int pe_enum_exports_callback(

	const void *			base,

	struct pe_raw_export_hdr *	exp_hdr,

	struct pe_export_sym *		sym,

	enum pe_callback_reason		reason,

	void *				context);

#if (__SIZEOF_POINTER__ == 4)

static char * pe_get_imported_symbol_info_32(

	const void *			sym_addr,

	struct pe_ldr_tbl_entry **	ldr_tbl_entry);

#endif

#if (__SIZEOF_POINTER__ == 8)

static char * pe_get_imported_symbol_info_64(

	const void *			sym_addr,

	struct pe_ldr_tbl_entry **	ldr_tbl_entry);

#endif

char * pe_get_symbol_name(const void * base, const void * sym_addr)

{

	struct pe_export_sym		exp_item;

	struct pe_symbol_name_ctx	ctx;

	ctx.name = 0;

	ctx.addr = sym_addr;

	pe_enum_image_exports(

		base,

		pe_enum_exports_callback,

		&exp_item,

		&ctx;;

	return ctx.name;

}

char * pe_get_import_symbol_info(

	const void *			sym_addr,

	struct pe_ldr_tbl_entry **	ldr_tbl_entry)

{

	#if (__SIZEOF_POINTER__ == 4)

		return pe_get_imported_symbol_info_32(

			sym_addr,

			ldr_tbl_entry);

	#elif (__SIZEOF_POINTER__ == 8)

		return pe_get_imported_symbol_info_64(

			sym_addr,

			ldr_tbl_entry);

	#endif

}

static int pe_enum_exports_callback(

	const void *			base,

	struct pe_raw_export_hdr *	exp_hdr,

	struct pe_export_sym  *		sym,

	enum pe_callback_reason		reason,

	void *				context)

{

	struct pe_symbol_name_ctx * ctx;

	(void)base;

	(void)exp_hdr;

	if (reason != PE_CALLBACK_REASON_ITEM)

		return 1;

	ctx = (struct pe_symbol_name_ctx *)context;

	if (sym->addr == ctx->addr) {

		ctx->name = sym->name;

		return 0;

	} else

		return 1;

}

#if (__SIZEOF_POINTER__ == 4)

static char * pe_get_imported_symbol_info_32(

	const void *			sym_addr,

	struct pe_ldr_tbl_entry **	ldr_tbl_entry)

{

	struct symbol {

		unsigned char	call;

		unsigned char	ds;

		unsigned char	sym_addr[4];

		unsigned char	padding[2];

	};

	char *				fn_name;

	struct pe_ldr_tbl_entry *	mod_info;

	void *				mod_base;

	uint32_t ***			sym_redirected_addr;

	struct symbol *			sym;

	fn_name  = 0;

	sym = (struct symbol *)sym_addr;

	if ((sym->call == 0xff) && (sym->ds == 0x25))

		if ((sym_redirected_addr = (uint32_t ***)sym->sym_addr))

			if ((mod_info = pe_get_symbol_module_info(

					**sym_redirected_addr)))

				if ((mod_base = mod_info->dll_base))

					fn_name = pe_get_symbol_name(

						mod_base,

						**sym_redirected_addr);

	if (fn_name && ldr_tbl_entry)

		*ldr_tbl_entry = mod_info;

	return fn_name;

}

#endif

#if (__SIZEOF_POINTER__ == 8)

static char * pe_get_imported_symbol_info_64(

	const void *			sym_addr,

	struct pe_ldr_tbl_entry **	ldr_tbl_entry)

{

	struct symbol {

		unsigned char	call;

		unsigned char	ds;

		unsigned char	sym_addr[4];

		unsigned char	padding[2];

	};

	char *				fn_name;

	struct pe_ldr_tbl_entry *	mod_info;

	void *				mod_base;

	uint32_t *			sym_offset;

	uint32_t			offset;

	struct symbol *			sym;

	fn_name  = 0;

	mod_info = 0;

	sym = (struct symbol *)sym_addr;

	if ((sym->call == 0xff) && (sym->ds == 0x25)) {

		if ((sym_offset = (uint32_t *)sym->sym_addr)) {

			offset   = *sym_offset;

			sym_addr = *(void **)(offset + (uintptr_t)(++sym_offset));

		} else

			sym_addr = 0;

		if (sym_addr && (mod_info = pe_get_symbol_module_info(sym_addr)))

			if ((mod_base = mod_info->dll_base))

				fn_name = pe_get_symbol_name(

					mod_base,

					sym_addr);

	}

	if (fn_name && ldr_tbl_entry)

		*ldr_tbl_entry = mod_info;

	return fn_name;

}

#endif